1 /* Handle parameterized types (templates) for GNU -*- C++ -*-.
2 Copyright (C) 1992-2016 Free Software Foundation, Inc.
3 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
4 Rewritten by Jason Merrill (jason@cygnus.com).
6 This file is part of GCC.
8 GCC is free software; you can redistribute it and/or modify
9 it under the terms of the GNU General Public License as published by
10 the Free Software Foundation; either version 3, or (at your option)
13 GCC is distributed in the hope that it will be useful,
14 but WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 GNU General Public License for more details.
18 You should have received a copy of the GNU General Public License
19 along with GCC; see the file COPYING3. If not see
20 <http://www.gnu.org/licenses/>. */
22 /* Known bugs or deficiencies include:
24 all methods must be provided in header files; can't use a source
25 file that contains only the method templates and "just win". */
29 #include "coretypes.h"
32 #include "stringpool.h"
35 #include "stor-layout.h"
37 #include "c-family/c-objc.h"
38 #include "cp-objcp-common.h"
40 #include "tree-iterator.h"
41 #include "type-utils.h"
44 /* The type of functions taking a tree, and some additional data, and
46 typedef int (*tree_fn_t) (tree, void*);
48 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
49 instantiations have been deferred, either because their definitions
50 were not yet available, or because we were putting off doing the work. */
51 struct GTY ((chain_next ("%h.next"))) pending_template {
52 struct pending_template *next;
53 struct tinst_level *tinst;
56 static GTY(()) struct pending_template *pending_templates;
57 static GTY(()) struct pending_template *last_pending_template;
59 int processing_template_parmlist;
60 static int template_header_count;
62 static GTY(()) tree saved_trees;
63 static vec<int> inline_parm_levels;
65 static GTY(()) struct tinst_level *current_tinst_level;
67 static GTY(()) tree saved_access_scope;
69 /* Live only within one (recursive) call to tsubst_expr. We use
70 this to pass the statement expression node from the STMT_EXPR
71 to the EXPR_STMT that is its result. */
72 static tree cur_stmt_expr;
74 // -------------------------------------------------------------------------- //
75 // Local Specialization Stack
77 // Implementation of the RAII helper for creating new local
79 local_specialization_stack::local_specialization_stack ()
80 : saved (local_specializations)
82 local_specializations = new hash_map<tree, tree>;
85 local_specialization_stack::~local_specialization_stack ()
87 delete local_specializations;
88 local_specializations = saved;
91 /* True if we've recursed into fn_type_unification too many times. */
92 static bool excessive_deduction_depth;
94 struct GTY((for_user)) spec_entry
101 struct spec_hasher : ggc_ptr_hash<spec_entry>
103 static hashval_t hash (spec_entry *);
104 static bool equal (spec_entry *, spec_entry *);
107 static GTY (()) hash_table<spec_hasher> *decl_specializations;
109 static GTY (()) hash_table<spec_hasher> *type_specializations;
111 /* Contains canonical template parameter types. The vector is indexed by
112 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
113 TREE_LIST, whose TREE_VALUEs contain the canonical template
114 parameters of various types and levels. */
115 static GTY(()) vec<tree, va_gc> *canonical_template_parms;
117 #define UNIFY_ALLOW_NONE 0
118 #define UNIFY_ALLOW_MORE_CV_QUAL 1
119 #define UNIFY_ALLOW_LESS_CV_QUAL 2
120 #define UNIFY_ALLOW_DERIVED 4
121 #define UNIFY_ALLOW_INTEGER 8
122 #define UNIFY_ALLOW_OUTER_LEVEL 16
123 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
124 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
126 enum template_base_result {
128 tbr_ambiguous_baseclass,
132 static void push_access_scope (tree);
133 static void pop_access_scope (tree);
134 static bool resolve_overloaded_unification (tree, tree, tree, tree,
135 unification_kind_t, int,
137 static int try_one_overload (tree, tree, tree, tree, tree,
138 unification_kind_t, int, bool, bool);
139 static int unify (tree, tree, tree, tree, int, bool);
140 static void add_pending_template (tree);
141 static tree reopen_tinst_level (struct tinst_level *);
142 static tree tsubst_initializer_list (tree, tree);
143 static tree get_partial_spec_bindings (tree, tree, tree, tree);
144 static tree coerce_template_parms (tree, tree, tree, tsubst_flags_t,
146 static tree coerce_innermost_template_parms (tree, tree, tree, tsubst_flags_t,
148 static void tsubst_enum (tree, tree, tree);
149 static tree add_to_template_args (tree, tree);
150 static tree add_outermost_template_args (tree, tree);
151 static bool check_instantiated_args (tree, tree, tsubst_flags_t);
152 static int maybe_adjust_types_for_deduction (unification_kind_t, tree*, tree*,
154 static int type_unification_real (tree, tree, tree, const tree *,
155 unsigned int, int, unification_kind_t, int,
156 vec<deferred_access_check, va_gc> **,
158 static void note_template_header (int);
159 static tree convert_nontype_argument_function (tree, tree, tsubst_flags_t);
160 static tree convert_nontype_argument (tree, tree, tsubst_flags_t);
161 static tree convert_template_argument (tree, tree, tree,
162 tsubst_flags_t, int, tree);
163 static tree for_each_template_parm (tree, tree_fn_t, void*,
164 hash_set<tree> *, bool);
165 static tree expand_template_argument_pack (tree);
166 static tree build_template_parm_index (int, int, int, tree, tree);
167 static bool inline_needs_template_parms (tree, bool);
168 static void push_inline_template_parms_recursive (tree, int);
169 static tree reduce_template_parm_level (tree, tree, int, tree, tsubst_flags_t);
170 static int mark_template_parm (tree, void *);
171 static int template_parm_this_level_p (tree, void *);
172 static tree tsubst_friend_function (tree, tree);
173 static tree tsubst_friend_class (tree, tree);
174 static int can_complete_type_without_circularity (tree);
175 static tree get_bindings (tree, tree, tree, bool);
176 static int template_decl_level (tree);
177 static int check_cv_quals_for_unify (int, tree, tree);
178 static void template_parm_level_and_index (tree, int*, int*);
179 static int unify_pack_expansion (tree, tree, tree,
180 tree, unification_kind_t, bool, bool);
181 static tree copy_template_args (tree);
182 static tree tsubst_template_arg (tree, tree, tsubst_flags_t, tree);
183 static tree tsubst_template_args (tree, tree, tsubst_flags_t, tree);
184 static tree tsubst_template_parms (tree, tree, tsubst_flags_t);
185 static tree most_specialized_partial_spec (tree, tsubst_flags_t);
186 static tree tsubst_aggr_type (tree, tree, tsubst_flags_t, tree, int);
187 static tree tsubst_arg_types (tree, tree, tree, tsubst_flags_t, tree);
188 static tree tsubst_function_type (tree, tree, tsubst_flags_t, tree);
189 static bool check_specialization_scope (void);
190 static tree process_partial_specialization (tree);
191 static void set_current_access_from_decl (tree);
192 static enum template_base_result get_template_base (tree, tree, tree, tree,
194 static tree try_class_unification (tree, tree, tree, tree, bool);
195 static int coerce_template_template_parms (tree, tree, tsubst_flags_t,
197 static bool template_template_parm_bindings_ok_p (tree, tree);
198 static void tsubst_default_arguments (tree, tsubst_flags_t);
199 static tree for_each_template_parm_r (tree *, int *, void *);
200 static tree copy_default_args_to_explicit_spec_1 (tree, tree);
201 static void copy_default_args_to_explicit_spec (tree);
202 static int invalid_nontype_parm_type_p (tree, tsubst_flags_t);
203 static bool dependent_template_arg_p (tree);
204 static bool any_template_arguments_need_structural_equality_p (tree);
205 static bool dependent_type_p_r (tree);
206 static tree tsubst_copy (tree, tree, tsubst_flags_t, tree);
207 static tree tsubst_decl (tree, tree, tsubst_flags_t);
208 static void perform_typedefs_access_check (tree tmpl, tree targs);
209 static void append_type_to_template_for_access_check_1 (tree, tree, tree,
211 static tree listify (tree);
212 static tree listify_autos (tree, tree);
213 static tree tsubst_template_parm (tree, tree, tsubst_flags_t);
214 static tree instantiate_alias_template (tree, tree, tsubst_flags_t);
215 static bool complex_alias_template_p (const_tree tmpl);
216 static tree tsubst_attributes (tree, tree, tsubst_flags_t, tree);
218 /* Make the current scope suitable for access checking when we are
219 processing T. T can be FUNCTION_DECL for instantiated function
220 template, VAR_DECL for static member variable, or TYPE_DECL for
221 alias template (needed by instantiate_decl). */
224 push_access_scope (tree t)
226 gcc_assert (VAR_OR_FUNCTION_DECL_P (t)
227 || TREE_CODE (t) == TYPE_DECL);
229 if (DECL_FRIEND_CONTEXT (t))
230 push_nested_class (DECL_FRIEND_CONTEXT (t));
231 else if (DECL_CLASS_SCOPE_P (t))
232 push_nested_class (DECL_CONTEXT (t));
234 push_to_top_level ();
236 if (TREE_CODE (t) == FUNCTION_DECL)
238 saved_access_scope = tree_cons
239 (NULL_TREE, current_function_decl, saved_access_scope);
240 current_function_decl = t;
244 /* Restore the scope set up by push_access_scope. T is the node we
248 pop_access_scope (tree t)
250 if (TREE_CODE (t) == FUNCTION_DECL)
252 current_function_decl = TREE_VALUE (saved_access_scope);
253 saved_access_scope = TREE_CHAIN (saved_access_scope);
256 if (DECL_FRIEND_CONTEXT (t) || DECL_CLASS_SCOPE_P (t))
259 pop_from_top_level ();
262 /* Do any processing required when DECL (a member template
263 declaration) is finished. Returns the TEMPLATE_DECL corresponding
264 to DECL, unless it is a specialization, in which case the DECL
265 itself is returned. */
268 finish_member_template_decl (tree decl)
270 if (decl == error_mark_node)
271 return error_mark_node;
273 gcc_assert (DECL_P (decl));
275 if (TREE_CODE (decl) == TYPE_DECL)
279 type = TREE_TYPE (decl);
280 if (type == error_mark_node)
281 return error_mark_node;
282 if (MAYBE_CLASS_TYPE_P (type)
283 && CLASSTYPE_TEMPLATE_INFO (type)
284 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
286 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
287 check_member_template (tmpl);
292 else if (TREE_CODE (decl) == FIELD_DECL)
293 error ("data member %qD cannot be a member template", decl);
294 else if (DECL_TEMPLATE_INFO (decl))
296 if (!DECL_TEMPLATE_SPECIALIZATION (decl))
298 check_member_template (DECL_TI_TEMPLATE (decl));
299 return DECL_TI_TEMPLATE (decl);
305 error ("invalid member template declaration %qD", decl);
307 return error_mark_node;
310 /* Create a template info node. */
313 build_template_info (tree template_decl, tree template_args)
315 tree result = make_node (TEMPLATE_INFO);
316 TI_TEMPLATE (result) = template_decl;
317 TI_ARGS (result) = template_args;
321 /* Return the template info node corresponding to T, whatever T is. */
324 get_template_info (const_tree t)
326 tree tinfo = NULL_TREE;
328 if (!t || t == error_mark_node)
331 if (TREE_CODE (t) == NAMESPACE_DECL
332 || TREE_CODE (t) == PARM_DECL)
335 if (DECL_P (t) && DECL_LANG_SPECIFIC (t))
336 tinfo = DECL_TEMPLATE_INFO (t);
338 if (!tinfo && DECL_IMPLICIT_TYPEDEF_P (t))
341 if (OVERLOAD_TYPE_P (t))
342 tinfo = TYPE_TEMPLATE_INFO (t);
343 else if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
344 tinfo = TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (t);
349 /* Returns the template nesting level of the indicated class TYPE.
359 A<T>::B<U> has depth two, while A<T> has depth one.
360 Both A<T>::B<int> and A<int>::B<U> have depth one, if
361 they are instantiations, not specializations.
363 This function is guaranteed to return 0 if passed NULL_TREE so
364 that, for example, `template_class_depth (current_class_type)' is
368 template_class_depth (tree type)
372 for (depth = 0; type && TREE_CODE (type) != NAMESPACE_DECL; )
374 tree tinfo = get_template_info (type);
376 if (tinfo && PRIMARY_TEMPLATE_P (TI_TEMPLATE (tinfo))
377 && uses_template_parms (INNERMOST_TEMPLATE_ARGS (TI_ARGS (tinfo))))
381 type = CP_DECL_CONTEXT (type);
382 else if (LAMBDA_TYPE_P (type))
383 type = LAMBDA_TYPE_EXTRA_SCOPE (type);
385 type = CP_TYPE_CONTEXT (type);
391 /* Subroutine of maybe_begin_member_template_processing.
392 Returns true if processing DECL needs us to push template parms. */
395 inline_needs_template_parms (tree decl, bool nsdmi)
397 if (!decl || (!nsdmi && ! DECL_TEMPLATE_INFO (decl)))
400 return (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (most_general_template (decl)))
401 > (processing_template_decl + DECL_TEMPLATE_SPECIALIZATION (decl)));
404 /* Subroutine of maybe_begin_member_template_processing.
405 Push the template parms in PARMS, starting from LEVELS steps into the
406 chain, and ending at the beginning, since template parms are listed
410 push_inline_template_parms_recursive (tree parmlist, int levels)
412 tree parms = TREE_VALUE (parmlist);
416 push_inline_template_parms_recursive (TREE_CHAIN (parmlist), levels - 1);
418 ++processing_template_decl;
419 current_template_parms
420 = tree_cons (size_int (processing_template_decl),
421 parms, current_template_parms);
422 TEMPLATE_PARMS_FOR_INLINE (current_template_parms) = 1;
424 begin_scope (TREE_VEC_LENGTH (parms) ? sk_template_parms : sk_template_spec,
426 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
428 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
430 if (error_operand_p (parm))
433 gcc_assert (DECL_P (parm));
435 switch (TREE_CODE (parm))
443 /* Push the CONST_DECL. */
444 pushdecl (TEMPLATE_PARM_DECL (DECL_INITIAL (parm)));
453 /* Restore the template parameter context for a member template, a
454 friend template defined in a class definition, or a non-template
455 member of template class. */
458 maybe_begin_member_template_processing (tree decl)
462 bool nsdmi = TREE_CODE (decl) == FIELD_DECL;
466 tree ctx = DECL_CONTEXT (decl);
467 decl = (CLASSTYPE_TEMPLATE_INFO (ctx)
468 /* Disregard full specializations (c++/60999). */
469 && uses_template_parms (ctx)
470 ? CLASSTYPE_TI_TEMPLATE (ctx) : NULL_TREE);
473 if (inline_needs_template_parms (decl, nsdmi))
475 parms = DECL_TEMPLATE_PARMS (most_general_template (decl));
476 levels = TMPL_PARMS_DEPTH (parms) - processing_template_decl;
478 if (DECL_TEMPLATE_SPECIALIZATION (decl))
481 parms = TREE_CHAIN (parms);
484 push_inline_template_parms_recursive (parms, levels);
487 /* Remember how many levels of template parameters we pushed so that
488 we can pop them later. */
489 inline_parm_levels.safe_push (levels);
492 /* Undo the effects of maybe_begin_member_template_processing. */
495 maybe_end_member_template_processing (void)
500 if (inline_parm_levels.length () == 0)
503 last = inline_parm_levels.pop ();
504 for (i = 0; i < last; ++i)
506 --processing_template_decl;
507 current_template_parms = TREE_CHAIN (current_template_parms);
512 /* Return a new template argument vector which contains all of ARGS,
513 but has as its innermost set of arguments the EXTRA_ARGS. */
516 add_to_template_args (tree args, tree extra_args)
523 if (args == NULL_TREE || extra_args == error_mark_node)
526 extra_depth = TMPL_ARGS_DEPTH (extra_args);
527 new_args = make_tree_vec (TMPL_ARGS_DEPTH (args) + extra_depth);
529 for (i = 1; i <= TMPL_ARGS_DEPTH (args); ++i)
530 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (args, i));
532 for (j = 1; j <= extra_depth; ++j, ++i)
533 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (extra_args, j));
538 /* Like add_to_template_args, but only the outermost ARGS are added to
539 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
540 (EXTRA_ARGS) levels are added. This function is used to combine
541 the template arguments from a partial instantiation with the
542 template arguments used to attain the full instantiation from the
543 partial instantiation. */
546 add_outermost_template_args (tree args, tree extra_args)
550 /* If there are more levels of EXTRA_ARGS than there are ARGS,
551 something very fishy is going on. */
552 gcc_assert (TMPL_ARGS_DEPTH (args) >= TMPL_ARGS_DEPTH (extra_args));
554 /* If *all* the new arguments will be the EXTRA_ARGS, just return
556 if (TMPL_ARGS_DEPTH (args) == TMPL_ARGS_DEPTH (extra_args))
559 /* For the moment, we make ARGS look like it contains fewer levels. */
560 TREE_VEC_LENGTH (args) -= TMPL_ARGS_DEPTH (extra_args);
562 new_args = add_to_template_args (args, extra_args);
564 /* Now, we restore ARGS to its full dimensions. */
565 TREE_VEC_LENGTH (args) += TMPL_ARGS_DEPTH (extra_args);
570 /* Return the N levels of innermost template arguments from the ARGS. */
573 get_innermost_template_args (tree args, int n)
581 /* If N is 1, just return the innermost set of template arguments. */
583 return TMPL_ARGS_LEVEL (args, TMPL_ARGS_DEPTH (args));
585 /* If we're not removing anything, just return the arguments we were
587 extra_levels = TMPL_ARGS_DEPTH (args) - n;
588 gcc_assert (extra_levels >= 0);
589 if (extra_levels == 0)
592 /* Make a new set of arguments, not containing the outer arguments. */
593 new_args = make_tree_vec (n);
594 for (i = 1; i <= n; ++i)
595 SET_TMPL_ARGS_LEVEL (new_args, i,
596 TMPL_ARGS_LEVEL (args, i + extra_levels));
601 /* The inverse of get_innermost_template_args: Return all but the innermost
602 EXTRA_LEVELS levels of template arguments from the ARGS. */
605 strip_innermost_template_args (tree args, int extra_levels)
608 int n = TMPL_ARGS_DEPTH (args) - extra_levels;
613 /* If N is 1, just return the outermost set of template arguments. */
615 return TMPL_ARGS_LEVEL (args, 1);
617 /* If we're not removing anything, just return the arguments we were
619 gcc_assert (extra_levels >= 0);
620 if (extra_levels == 0)
623 /* Make a new set of arguments, not containing the inner arguments. */
624 new_args = make_tree_vec (n);
625 for (i = 1; i <= n; ++i)
626 SET_TMPL_ARGS_LEVEL (new_args, i,
627 TMPL_ARGS_LEVEL (args, i));
632 /* We've got a template header coming up; push to a new level for storing
636 begin_template_parm_list (void)
638 /* We use a non-tag-transparent scope here, which causes pushtag to
639 put tags in this scope, rather than in the enclosing class or
640 namespace scope. This is the right thing, since we want
641 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
642 global template class, push_template_decl handles putting the
643 TEMPLATE_DECL into top-level scope. For a nested template class,
646 template <class T> struct S1 {
647 template <class T> struct S2 {};
650 pushtag contains special code to call pushdecl_with_scope on the
651 TEMPLATE_DECL for S2. */
652 begin_scope (sk_template_parms, NULL);
653 ++processing_template_decl;
654 ++processing_template_parmlist;
655 note_template_header (0);
657 /* Add a dummy parameter level while we process the parameter list. */
658 current_template_parms
659 = tree_cons (size_int (processing_template_decl),
661 current_template_parms);
664 /* This routine is called when a specialization is declared. If it is
665 invalid to declare a specialization here, an error is reported and
666 false is returned, otherwise this routine will return true. */
669 check_specialization_scope (void)
671 tree scope = current_scope ();
675 An explicit specialization shall be declared in the namespace of
676 which the template is a member, or, for member templates, in the
677 namespace of which the enclosing class or enclosing class
678 template is a member. An explicit specialization of a member
679 function, member class or static data member of a class template
680 shall be declared in the namespace of which the class template
682 if (scope && TREE_CODE (scope) != NAMESPACE_DECL)
684 error ("explicit specialization in non-namespace scope %qD", scope);
690 In an explicit specialization declaration for a member of a class
691 template or a member template that appears in namespace scope,
692 the member template and some of its enclosing class templates may
693 remain unspecialized, except that the declaration shall not
694 explicitly specialize a class member template if its enclosing
695 class templates are not explicitly specialized as well. */
696 if (current_template_parms)
698 error ("enclosing class templates are not explicitly specialized");
705 /* We've just seen template <>. */
708 begin_specialization (void)
710 begin_scope (sk_template_spec, NULL);
711 note_template_header (1);
712 return check_specialization_scope ();
715 /* Called at then end of processing a declaration preceded by
719 end_specialization (void)
722 reset_specialization ();
725 /* Any template <>'s that we have seen thus far are not referring to a
726 function specialization. */
729 reset_specialization (void)
731 processing_specialization = 0;
732 template_header_count = 0;
735 /* We've just seen a template header. If SPECIALIZATION is nonzero,
736 it was of the form template <>. */
739 note_template_header (int specialization)
741 processing_specialization = specialization;
742 template_header_count++;
745 /* We're beginning an explicit instantiation. */
748 begin_explicit_instantiation (void)
750 gcc_assert (!processing_explicit_instantiation);
751 processing_explicit_instantiation = true;
756 end_explicit_instantiation (void)
758 gcc_assert (processing_explicit_instantiation);
759 processing_explicit_instantiation = false;
762 /* An explicit specialization or partial specialization of TMPL is being
763 declared. Check that the namespace in which the specialization is
764 occurring is permissible. Returns false iff it is invalid to
765 specialize TMPL in the current namespace. */
768 check_specialization_namespace (tree tmpl)
770 tree tpl_ns = decl_namespace_context (tmpl);
774 An explicit specialization shall be declared in the namespace of
775 which the template is a member, or, for member templates, in the
776 namespace of which the enclosing class or enclosing class
777 template is a member. An explicit specialization of a member
778 function, member class or static data member of a class template
779 shall be declared in the namespace of which the class template is
781 if (current_scope() != DECL_CONTEXT (tmpl)
782 && !at_namespace_scope_p ())
784 error ("specialization of %qD must appear at namespace scope", tmpl);
787 if (is_associated_namespace (current_namespace, tpl_ns))
788 /* Same or super-using namespace. */
792 permerror (input_location,
793 "specialization of %qD in different namespace", tmpl);
794 permerror (DECL_SOURCE_LOCATION (tmpl),
795 " from definition of %q#D", tmpl);
800 /* SPEC is an explicit instantiation. Check that it is valid to
801 perform this explicit instantiation in the current namespace. */
804 check_explicit_instantiation_namespace (tree spec)
808 /* DR 275: An explicit instantiation shall appear in an enclosing
809 namespace of its template. */
810 ns = decl_namespace_context (spec);
811 if (!is_ancestor (current_namespace, ns))
812 permerror (input_location, "explicit instantiation of %qD in namespace %qD "
813 "(which does not enclose namespace %qD)",
814 spec, current_namespace, ns);
817 // Returns the type of a template specialization only if that
818 // specialization needs to be defined. Otherwise (e.g., if the type has
819 // already been defined), the function returns NULL_TREE.
821 maybe_new_partial_specialization (tree type)
823 // An implicit instantiation of an incomplete type implies
824 // the definition of a new class template.
826 // template<typename T>
829 // template<typename T>
832 // Here, S<T*> is an implicit instantiation of S whose type
834 if (CLASSTYPE_IMPLICIT_INSTANTIATION (type) && !COMPLETE_TYPE_P (type))
837 // It can also be the case that TYPE is a completed specialization.
838 // Continuing the previous example, suppose we also declare:
840 // template<typename T>
841 // requires Integral<T>
844 // Here, S<T*> refers to the specialization S<T*> defined
845 // above. However, we need to differentiate definitions because
846 // we intend to define a new partial specialization. In this case,
847 // we rely on the fact that the constraints are different for
848 // this declaration than that above.
850 // Note that we also get here for injected class names and
851 // late-parsed template definitions. We must ensure that we
852 // do not create new type declarations for those cases.
853 if (flag_concepts && CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
855 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
856 tree args = CLASSTYPE_TI_ARGS (type);
858 // If there are no template parameters, this cannot be a new
859 // partial template specializtion?
860 if (!current_template_parms)
863 // The injected-class-name is not a new partial specialization.
864 if (DECL_SELF_REFERENCE_P (TYPE_NAME (type)))
867 // If the constraints are not the same as those of the primary
868 // then, we can probably create a new specialization.
869 tree type_constr = current_template_constraints ();
871 if (type == TREE_TYPE (tmpl))
873 tree main_constr = get_constraints (tmpl);
874 if (equivalent_constraints (type_constr, main_constr))
878 // Also, if there's a pre-existing specialization with matching
879 // constraints, then this also isn't new.
880 tree specs = DECL_TEMPLATE_SPECIALIZATIONS (tmpl);
883 tree spec_tmpl = TREE_VALUE (specs);
884 tree spec_args = TREE_PURPOSE (specs);
885 tree spec_constr = get_constraints (spec_tmpl);
886 if (comp_template_args (args, spec_args)
887 && equivalent_constraints (type_constr, spec_constr))
889 specs = TREE_CHAIN (specs);
892 // Create a new type node (and corresponding type decl)
893 // for the newly declared specialization.
894 tree t = make_class_type (TREE_CODE (type));
895 CLASSTYPE_DECLARED_CLASS (t) = CLASSTYPE_DECLARED_CLASS (type);
896 TYPE_FOR_JAVA (t) = TYPE_FOR_JAVA (type);
897 SET_TYPE_TEMPLATE_INFO (t, build_template_info (tmpl, args));
899 /* We only need a separate type node for storing the definition of this
900 partial specialization; uses of S<T*> are unconstrained, so all are
901 equivalent. So keep TYPE_CANONICAL the same. */
902 TYPE_CANONICAL (t) = TYPE_CANONICAL (type);
904 // Build the corresponding type decl.
905 tree d = create_implicit_typedef (DECL_NAME (tmpl), t);
906 DECL_CONTEXT (d) = TYPE_CONTEXT (t);
907 DECL_SOURCE_LOCATION (d) = input_location;
915 /* The TYPE is being declared. If it is a template type, that means it
916 is a partial specialization. Do appropriate error-checking. */
919 maybe_process_partial_specialization (tree type)
923 if (type == error_mark_node)
924 return error_mark_node;
926 /* A lambda that appears in specialization context is not itself a
928 if (CLASS_TYPE_P (type) && CLASSTYPE_LAMBDA_EXPR (type))
931 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
933 error ("name of class shadows template template parameter %qD",
935 return error_mark_node;
938 context = TYPE_CONTEXT (type);
940 if (TYPE_ALIAS_P (type))
942 if (TYPE_TEMPLATE_INFO (type)
943 && DECL_ALIAS_TEMPLATE_P (TYPE_TI_TEMPLATE (type)))
944 error ("specialization of alias template %qD",
945 TYPE_TI_TEMPLATE (type));
947 error ("explicit specialization of non-template %qT", type);
948 return error_mark_node;
950 else if (CLASS_TYPE_P (type) && CLASSTYPE_USE_TEMPLATE (type))
952 /* This is for ordinary explicit specialization and partial
953 specialization of a template class such as:
955 template <> class C<int>;
959 template <class T> class C<T*>;
961 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
963 if (tree t = maybe_new_partial_specialization (type))
965 if (!check_specialization_namespace (CLASSTYPE_TI_TEMPLATE (t))
966 && !at_namespace_scope_p ())
967 return error_mark_node;
968 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (t);
969 DECL_SOURCE_LOCATION (TYPE_MAIN_DECL (t)) = input_location;
970 if (processing_template_decl)
972 tree decl = push_template_decl (TYPE_MAIN_DECL (t));
973 if (decl == error_mark_node)
974 return error_mark_node;
975 return TREE_TYPE (decl);
978 else if (CLASSTYPE_TEMPLATE_INSTANTIATION (type))
979 error ("specialization of %qT after instantiation", type);
980 else if (errorcount && !processing_specialization
981 && CLASSTYPE_TEMPLATE_SPECIALIZATION (type)
982 && !uses_template_parms (CLASSTYPE_TI_ARGS (type)))
983 /* Trying to define a specialization either without a template<> header
984 or in an inappropriate place. We've already given an error, so just
985 bail now so we don't actually define the specialization. */
986 return error_mark_node;
988 else if (CLASS_TYPE_P (type)
989 && !CLASSTYPE_USE_TEMPLATE (type)
990 && CLASSTYPE_TEMPLATE_INFO (type)
991 && context && CLASS_TYPE_P (context)
992 && CLASSTYPE_TEMPLATE_INFO (context))
994 /* This is for an explicit specialization of member class
995 template according to [temp.expl.spec/18]:
997 template <> template <class U> class C<int>::D;
999 The context `C<int>' must be an implicit instantiation.
1000 Otherwise this is just a member class template declared
1003 template <> class C<int> { template <class U> class D; };
1004 template <> template <class U> class C<int>::D;
1006 In the first case, `C<int>::D' is a specialization of `C<T>::D'
1007 while in the second case, `C<int>::D' is a primary template
1008 and `C<T>::D' may not exist. */
1010 if (CLASSTYPE_IMPLICIT_INSTANTIATION (context)
1011 && !COMPLETE_TYPE_P (type))
1014 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
1016 if (current_namespace
1017 != decl_namespace_context (tmpl))
1019 permerror (input_location,
1020 "specializing %q#T in different namespace", type);
1021 permerror (DECL_SOURCE_LOCATION (tmpl),
1022 " from definition of %q#D", tmpl);
1025 /* Check for invalid specialization after instantiation:
1027 template <> template <> class C<int>::D<int>;
1028 template <> template <class U> class C<int>::D; */
1030 for (t = DECL_TEMPLATE_INSTANTIATIONS (tmpl);
1031 t; t = TREE_CHAIN (t))
1033 tree inst = TREE_VALUE (t);
1034 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (inst)
1035 || !COMPLETE_OR_OPEN_TYPE_P (inst))
1037 /* We already have a full specialization of this partial
1038 instantiation, or a full specialization has been
1039 looked up but not instantiated. Reassign it to the
1040 new member specialization template. */
1044 elt.tmpl = most_general_template (tmpl);
1045 elt.args = CLASSTYPE_TI_ARGS (inst);
1048 type_specializations->remove_elt (&elt);
1051 elt.args = INNERMOST_TEMPLATE_ARGS (elt.args);
1054 = type_specializations->find_slot (&elt, INSERT);
1055 entry = ggc_alloc<spec_entry> ();
1060 /* But if we've had an implicit instantiation, that's a
1061 problem ([temp.expl.spec]/6). */
1062 error ("specialization %qT after instantiation %qT",
1066 /* Mark TYPE as a specialization. And as a result, we only
1067 have one level of template argument for the innermost
1069 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
1070 DECL_SOURCE_LOCATION (TYPE_MAIN_DECL (type)) = input_location;
1071 CLASSTYPE_TI_ARGS (type)
1072 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type));
1075 else if (processing_specialization)
1077 /* Someday C++0x may allow for enum template specialization. */
1078 if (cxx_dialect > cxx98 && TREE_CODE (type) == ENUMERAL_TYPE
1079 && CLASS_TYPE_P (context) && CLASSTYPE_USE_TEMPLATE (context))
1080 pedwarn (input_location, OPT_Wpedantic, "template specialization "
1081 "of %qD not allowed by ISO C++", type);
1084 error ("explicit specialization of non-template %qT", type);
1085 return error_mark_node;
1092 /* Returns nonzero if we can optimize the retrieval of specializations
1093 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
1094 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
1097 optimize_specialization_lookup_p (tree tmpl)
1099 return (DECL_FUNCTION_TEMPLATE_P (tmpl)
1100 && DECL_CLASS_SCOPE_P (tmpl)
1101 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
1103 && CLASS_TYPE_P (DECL_CONTEXT (tmpl))
1104 /* The optimized lookup depends on the fact that the
1105 template arguments for the member function template apply
1106 purely to the containing class, which is not true if the
1107 containing class is an explicit or partial
1109 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (tmpl))
1110 && !DECL_MEMBER_TEMPLATE_P (tmpl)
1111 && !DECL_CONV_FN_P (tmpl)
1112 /* It is possible to have a template that is not a member
1113 template and is not a member of a template class:
1115 template <typename T>
1116 struct S { friend A::f(); };
1118 Here, the friend function is a template, but the context does
1119 not have template information. The optimized lookup relies
1120 on having ARGS be the template arguments for both the class
1121 and the function template. */
1122 && !DECL_FRIEND_P (DECL_TEMPLATE_RESULT (tmpl)));
1125 /* Make sure ARGS doesn't use any inappropriate typedefs; we should have
1126 gone through coerce_template_parms by now. */
1129 verify_unstripped_args (tree args)
1131 ++processing_template_decl;
1132 if (!any_dependent_template_arguments_p (args))
1134 tree inner = INNERMOST_TEMPLATE_ARGS (args);
1135 for (int i = 0; i < TREE_VEC_LENGTH (inner); ++i)
1137 tree arg = TREE_VEC_ELT (inner, i);
1138 if (TREE_CODE (arg) == TEMPLATE_DECL)
1140 else if (TYPE_P (arg))
1141 gcc_assert (strip_typedefs (arg, NULL) == arg);
1142 else if (strip_typedefs (TREE_TYPE (arg), NULL) != TREE_TYPE (arg))
1143 /* Allow typedefs on the type of a non-type argument, since a
1144 parameter can have them. */;
1146 gcc_assert (strip_typedefs_expr (arg, NULL) == arg);
1149 --processing_template_decl;
1152 /* Retrieve the specialization (in the sense of [temp.spec] - a
1153 specialization is either an instantiation or an explicit
1154 specialization) of TMPL for the given template ARGS. If there is
1155 no such specialization, return NULL_TREE. The ARGS are a vector of
1156 arguments, or a vector of vectors of arguments, in the case of
1157 templates with more than one level of parameters.
1159 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
1160 then we search for a partial specialization matching ARGS. This
1161 parameter is ignored if TMPL is not a class template.
1163 We can also look up a FIELD_DECL, if it is a lambda capture pack; the
1164 result is a NONTYPE_ARGUMENT_PACK. */
1167 retrieve_specialization (tree tmpl, tree args, hashval_t hash)
1169 if (tmpl == NULL_TREE)
1172 if (args == error_mark_node)
1175 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL
1176 || TREE_CODE (tmpl) == FIELD_DECL);
1178 /* There should be as many levels of arguments as there are
1179 levels of parameters. */
1180 gcc_assert (TMPL_ARGS_DEPTH (args)
1181 == (TREE_CODE (tmpl) == TEMPLATE_DECL
1182 ? TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl))
1183 : template_class_depth (DECL_CONTEXT (tmpl))));
1186 verify_unstripped_args (args);
1188 if (optimize_specialization_lookup_p (tmpl))
1190 tree class_template;
1191 tree class_specialization;
1192 vec<tree, va_gc> *methods;
1196 /* The template arguments actually apply to the containing
1197 class. Find the class specialization with those
1199 class_template = CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (tmpl));
1200 class_specialization
1201 = retrieve_specialization (class_template, args, 0);
1202 if (!class_specialization)
1204 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
1205 for the specialization. */
1206 idx = class_method_index_for_fn (class_specialization, tmpl);
1209 /* Iterate through the methods with the indicated name, looking
1210 for the one that has an instance of TMPL. */
1211 methods = CLASSTYPE_METHOD_VEC (class_specialization);
1212 for (fns = (*methods)[idx]; fns; fns = OVL_NEXT (fns))
1214 tree fn = OVL_CURRENT (fns);
1215 if (DECL_TEMPLATE_INFO (fn) && DECL_TI_TEMPLATE (fn) == tmpl
1216 /* using-declarations can add base methods to the method vec,
1217 and we don't want those here. */
1218 && DECL_CONTEXT (fn) == class_specialization)
1227 hash_table<spec_hasher> *specializations;
1231 elt.spec = NULL_TREE;
1233 if (DECL_CLASS_TEMPLATE_P (tmpl))
1234 specializations = type_specializations;
1236 specializations = decl_specializations;
1239 hash = spec_hasher::hash (&elt);
1240 found = specializations->find_with_hash (&elt, hash);
1248 /* Like retrieve_specialization, but for local declarations. */
1251 retrieve_local_specialization (tree tmpl)
1253 if (local_specializations == NULL)
1256 tree *slot = local_specializations->get (tmpl);
1257 return slot ? *slot : NULL_TREE;
1260 /* Returns nonzero iff DECL is a specialization of TMPL. */
1263 is_specialization_of (tree decl, tree tmpl)
1267 if (TREE_CODE (decl) == FUNCTION_DECL)
1271 t = DECL_TEMPLATE_INFO (t) ? DECL_TI_TEMPLATE (t) : NULL_TREE)
1277 gcc_assert (TREE_CODE (decl) == TYPE_DECL);
1279 for (t = TREE_TYPE (decl);
1281 t = CLASSTYPE_USE_TEMPLATE (t)
1282 ? TREE_TYPE (CLASSTYPE_TI_TEMPLATE (t)) : NULL_TREE)
1283 if (same_type_ignoring_top_level_qualifiers_p (t, TREE_TYPE (tmpl)))
1290 /* Returns nonzero iff DECL is a specialization of friend declaration
1291 FRIEND_DECL according to [temp.friend]. */
1294 is_specialization_of_friend (tree decl, tree friend_decl)
1296 bool need_template = true;
1299 gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
1300 || TREE_CODE (decl) == TYPE_DECL);
1302 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1303 of a template class, we want to check if DECL is a specialization
1305 if (TREE_CODE (friend_decl) == FUNCTION_DECL
1306 && DECL_TEMPLATE_INFO (friend_decl)
1307 && !DECL_USE_TEMPLATE (friend_decl))
1309 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1310 friend_decl = DECL_TI_TEMPLATE (friend_decl);
1311 need_template = false;
1313 else if (TREE_CODE (friend_decl) == TEMPLATE_DECL
1314 && !PRIMARY_TEMPLATE_P (friend_decl))
1315 need_template = false;
1317 /* There is nothing to do if this is not a template friend. */
1318 if (TREE_CODE (friend_decl) != TEMPLATE_DECL)
1321 if (is_specialization_of (decl, friend_decl))
1325 A member of a class template may be declared to be a friend of a
1326 non-template class. In this case, the corresponding member of
1327 every specialization of the class template is a friend of the
1328 class granting friendship.
1330 For example, given a template friend declaration
1332 template <class T> friend void A<T>::f();
1334 the member function below is considered a friend
1336 template <> struct A<int> {
1340 For this type of template friend, TEMPLATE_DEPTH below will be
1341 nonzero. To determine if DECL is a friend of FRIEND, we first
1342 check if the enclosing class is a specialization of another. */
1344 template_depth = template_class_depth (CP_DECL_CONTEXT (friend_decl));
1346 && DECL_CLASS_SCOPE_P (decl)
1347 && is_specialization_of (TYPE_NAME (DECL_CONTEXT (decl)),
1348 CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (friend_decl))))
1350 /* Next, we check the members themselves. In order to handle
1351 a few tricky cases, such as when FRIEND_DECL's are
1353 template <class T> friend void A<T>::g(T t);
1354 template <class T> template <T t> friend void A<T>::h();
1358 void A<int>::g(int);
1359 template <int> void A<int>::h();
1361 we need to figure out ARGS, the template arguments from
1362 the context of DECL. This is required for template substitution
1363 of `T' in the function parameter of `g' and template parameter
1364 of `h' in the above examples. Here ARGS corresponds to `int'. */
1366 tree context = DECL_CONTEXT (decl);
1367 tree args = NULL_TREE;
1368 int current_depth = 0;
1370 while (current_depth < template_depth)
1372 if (CLASSTYPE_TEMPLATE_INFO (context))
1374 if (current_depth == 0)
1375 args = TYPE_TI_ARGS (context);
1377 args = add_to_template_args (TYPE_TI_ARGS (context), args);
1380 context = TYPE_CONTEXT (context);
1383 if (TREE_CODE (decl) == FUNCTION_DECL)
1388 tree friend_args_type;
1389 tree decl_args_type;
1391 /* Make sure that both DECL and FRIEND_DECL are templates or
1393 is_template = DECL_TEMPLATE_INFO (decl)
1394 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (decl));
1395 if (need_template ^ is_template)
1397 else if (is_template)
1399 /* If both are templates, check template parameter list. */
1401 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1403 if (!comp_template_parms
1404 (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (decl)),
1408 decl_type = TREE_TYPE (DECL_TI_TEMPLATE (decl));
1411 decl_type = TREE_TYPE (decl);
1413 friend_type = tsubst_function_type (TREE_TYPE (friend_decl), args,
1414 tf_none, NULL_TREE);
1415 if (friend_type == error_mark_node)
1418 /* Check if return types match. */
1419 if (!same_type_p (TREE_TYPE (decl_type), TREE_TYPE (friend_type)))
1422 /* Check if function parameter types match, ignoring the
1423 `this' parameter. */
1424 friend_args_type = TYPE_ARG_TYPES (friend_type);
1425 decl_args_type = TYPE_ARG_TYPES (decl_type);
1426 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (friend_decl))
1427 friend_args_type = TREE_CHAIN (friend_args_type);
1428 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1429 decl_args_type = TREE_CHAIN (decl_args_type);
1431 return compparms (decl_args_type, friend_args_type);
1435 /* DECL is a TYPE_DECL */
1437 tree decl_type = TREE_TYPE (decl);
1439 /* Make sure that both DECL and FRIEND_DECL are templates or
1442 = CLASSTYPE_TEMPLATE_INFO (decl_type)
1443 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (decl_type));
1445 if (need_template ^ is_template)
1447 else if (is_template)
1450 /* If both are templates, check the name of the two
1451 TEMPLATE_DECL's first because is_friend didn't. */
1452 if (DECL_NAME (CLASSTYPE_TI_TEMPLATE (decl_type))
1453 != DECL_NAME (friend_decl))
1456 /* Now check template parameter list. */
1458 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1460 return comp_template_parms
1461 (DECL_TEMPLATE_PARMS (CLASSTYPE_TI_TEMPLATE (decl_type)),
1465 return (DECL_NAME (decl)
1466 == DECL_NAME (friend_decl));
1472 /* Register the specialization SPEC as a specialization of TMPL with
1473 the indicated ARGS. IS_FRIEND indicates whether the specialization
1474 is actually just a friend declaration. Returns SPEC, or an
1475 equivalent prior declaration, if available.
1477 We also store instantiations of field packs in the hash table, even
1478 though they are not themselves templates, to make lookup easier. */
1481 register_specialization (tree spec, tree tmpl, tree args, bool is_friend,
1485 spec_entry **slot = NULL;
1488 gcc_assert ((TREE_CODE (tmpl) == TEMPLATE_DECL && DECL_P (spec))
1489 || (TREE_CODE (tmpl) == FIELD_DECL
1490 && TREE_CODE (spec) == NONTYPE_ARGUMENT_PACK));
1492 if (TREE_CODE (spec) == FUNCTION_DECL
1493 && uses_template_parms (DECL_TI_ARGS (spec)))
1494 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1495 register it; we want the corresponding TEMPLATE_DECL instead.
1496 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1497 the more obvious `uses_template_parms (spec)' to avoid problems
1498 with default function arguments. In particular, given
1499 something like this:
1501 template <class T> void f(T t1, T t = T())
1503 the default argument expression is not substituted for in an
1504 instantiation unless and until it is actually needed. */
1507 if (optimize_specialization_lookup_p (tmpl))
1508 /* We don't put these specializations in the hash table, but we might
1509 want to give an error about a mismatch. */
1510 fn = retrieve_specialization (tmpl, args, 0);
1518 hash = spec_hasher::hash (&elt);
1521 decl_specializations->find_slot_with_hash (&elt, hash, INSERT);
1523 fn = ((spec_entry *) *slot)->spec;
1528 /* We can sometimes try to re-register a specialization that we've
1529 already got. In particular, regenerate_decl_from_template calls
1530 duplicate_decls which will update the specialization list. But,
1531 we'll still get called again here anyhow. It's more convenient
1532 to simply allow this than to try to prevent it. */
1535 else if (fn && DECL_TEMPLATE_SPECIALIZATION (spec))
1537 if (DECL_TEMPLATE_INSTANTIATION (fn))
1539 if (DECL_ODR_USED (fn)
1540 || DECL_EXPLICIT_INSTANTIATION (fn))
1542 error ("specialization of %qD after instantiation",
1544 return error_mark_node;
1549 /* This situation should occur only if the first
1550 specialization is an implicit instantiation, the
1551 second is an explicit specialization, and the
1552 implicit instantiation has not yet been used. That
1553 situation can occur if we have implicitly
1554 instantiated a member function and then specialized
1557 We can also wind up here if a friend declaration that
1558 looked like an instantiation turns out to be a
1561 template <class T> void foo(T);
1562 class S { friend void foo<>(int) };
1563 template <> void foo(int);
1565 We transform the existing DECL in place so that any
1566 pointers to it become pointers to the updated
1569 If there was a definition for the template, but not
1570 for the specialization, we want this to look as if
1571 there were no definition, and vice versa. */
1572 DECL_INITIAL (fn) = NULL_TREE;
1573 duplicate_decls (spec, fn, is_friend);
1574 /* The call to duplicate_decls will have applied
1577 An explicit specialization of a function template
1578 is inline only if it is explicitly declared to be,
1579 and independently of whether its function template
1582 to the primary function; now copy the inline bits to
1583 the various clones. */
1584 FOR_EACH_CLONE (clone, fn)
1586 DECL_DECLARED_INLINE_P (clone)
1587 = DECL_DECLARED_INLINE_P (fn);
1588 DECL_SOURCE_LOCATION (clone)
1589 = DECL_SOURCE_LOCATION (fn);
1590 DECL_DELETED_FN (clone)
1591 = DECL_DELETED_FN (fn);
1593 check_specialization_namespace (tmpl);
1598 else if (DECL_TEMPLATE_SPECIALIZATION (fn))
1600 if (!duplicate_decls (spec, fn, is_friend) && DECL_INITIAL (spec))
1601 /* Dup decl failed, but this is a new definition. Set the
1602 line number so any errors match this new
1604 DECL_SOURCE_LOCATION (fn) = DECL_SOURCE_LOCATION (spec);
1610 return duplicate_decls (spec, fn, is_friend);
1612 /* A specialization must be declared in the same namespace as the
1613 template it is specializing. */
1614 if (DECL_P (spec) && DECL_TEMPLATE_SPECIALIZATION (spec)
1615 && !check_specialization_namespace (tmpl))
1616 DECL_CONTEXT (spec) = DECL_CONTEXT (tmpl);
1618 if (slot != NULL /* !optimize_specialization_lookup_p (tmpl) */)
1620 spec_entry *entry = ggc_alloc<spec_entry> ();
1621 gcc_assert (tmpl && args && spec);
1624 if ((TREE_CODE (spec) == FUNCTION_DECL && DECL_NAMESPACE_SCOPE_P (spec)
1625 && PRIMARY_TEMPLATE_P (tmpl)
1626 && DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (tmpl)) == NULL_TREE)
1627 || variable_template_p (tmpl))
1628 /* If TMPL is a forward declaration of a template function, keep a list
1629 of all specializations in case we need to reassign them to a friend
1630 template later in tsubst_friend_function.
1632 Also keep a list of all variable template instantiations so that
1633 process_partial_specialization can check whether a later partial
1634 specialization would have used it. */
1635 DECL_TEMPLATE_INSTANTIATIONS (tmpl)
1636 = tree_cons (args, spec, DECL_TEMPLATE_INSTANTIATIONS (tmpl));
1642 /* Returns true iff two spec_entry nodes are equivalent. */
1644 int comparing_specializations;
1647 spec_hasher::equal (spec_entry *e1, spec_entry *e2)
1651 ++comparing_specializations;
1652 equal = (e1->tmpl == e2->tmpl
1653 && comp_template_args (e1->args, e2->args));
1654 if (equal && flag_concepts
1655 /* tmpl could be a FIELD_DECL for a capture pack. */
1656 && TREE_CODE (e1->tmpl) == TEMPLATE_DECL
1657 && VAR_P (DECL_TEMPLATE_RESULT (e1->tmpl))
1658 && uses_template_parms (e1->args))
1660 /* Partial specializations of a variable template can be distinguished by
1662 tree c1 = e1->spec ? get_constraints (e1->spec) : NULL_TREE;
1663 tree c2 = e2->spec ? get_constraints (e2->spec) : NULL_TREE;
1664 equal = equivalent_constraints (c1, c2);
1666 --comparing_specializations;
1671 /* Returns a hash for a template TMPL and template arguments ARGS. */
1674 hash_tmpl_and_args (tree tmpl, tree args)
1676 hashval_t val = iterative_hash_object (DECL_UID (tmpl), 0);
1677 return iterative_hash_template_arg (args, val);
1680 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1684 spec_hasher::hash (spec_entry *e)
1686 return hash_tmpl_and_args (e->tmpl, e->args);
1689 /* Recursively calculate a hash value for a template argument ARG, for use
1690 in the hash tables of template specializations. */
1693 iterative_hash_template_arg (tree arg, hashval_t val)
1695 unsigned HOST_WIDE_INT i;
1696 enum tree_code code;
1699 if (arg == NULL_TREE)
1700 return iterative_hash_object (arg, val);
1705 if (TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
1706 /* We can get one of these when re-hashing a previous entry in the middle
1707 of substituting into a pack expansion. Just look through it. */
1708 arg = ARGUMENT_PACK_SELECT_FROM_PACK (arg);
1710 code = TREE_CODE (arg);
1711 tclass = TREE_CODE_CLASS (code);
1713 val = iterative_hash_object (code, val);
1720 case IDENTIFIER_NODE:
1721 return iterative_hash_object (IDENTIFIER_HASH_VALUE (arg), val);
1725 int i, len = TREE_VEC_LENGTH (arg);
1726 for (i = 0; i < len; ++i)
1727 val = iterative_hash_template_arg (TREE_VEC_ELT (arg, i), val);
1731 case TYPE_PACK_EXPANSION:
1732 case EXPR_PACK_EXPANSION:
1733 val = iterative_hash_template_arg (PACK_EXPANSION_PATTERN (arg), val);
1734 return iterative_hash_template_arg (PACK_EXPANSION_EXTRA_ARGS (arg), val);
1736 case TYPE_ARGUMENT_PACK:
1737 case NONTYPE_ARGUMENT_PACK:
1738 return iterative_hash_template_arg (ARGUMENT_PACK_ARGS (arg), val);
1741 for (; arg; arg = TREE_CHAIN (arg))
1742 val = iterative_hash_template_arg (TREE_VALUE (arg), val);
1746 for (; arg; arg = OVL_NEXT (arg))
1747 val = iterative_hash_template_arg (OVL_CURRENT (arg), val);
1753 iterative_hash_template_arg (TREE_TYPE (arg), val);
1754 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg), i, field, value)
1756 val = iterative_hash_template_arg (field, val);
1757 val = iterative_hash_template_arg (value, val);
1763 if (!DECL_ARTIFICIAL (arg))
1765 val = iterative_hash_object (DECL_PARM_INDEX (arg), val);
1766 val = iterative_hash_object (DECL_PARM_LEVEL (arg), val);
1768 return iterative_hash_template_arg (TREE_TYPE (arg), val);
1771 return iterative_hash_template_arg (TARGET_EXPR_INITIAL (arg), val);
1774 val = iterative_hash_template_arg (PTRMEM_CST_CLASS (arg), val);
1775 return iterative_hash_template_arg (PTRMEM_CST_MEMBER (arg), val);
1777 case TEMPLATE_PARM_INDEX:
1778 val = iterative_hash_template_arg
1779 (TREE_TYPE (TEMPLATE_PARM_DECL (arg)), val);
1780 val = iterative_hash_object (TEMPLATE_PARM_LEVEL (arg), val);
1781 return iterative_hash_object (TEMPLATE_PARM_IDX (arg), val);
1784 val = iterative_hash_object (TRAIT_EXPR_KIND (arg), val);
1785 val = iterative_hash_template_arg (TRAIT_EXPR_TYPE1 (arg), val);
1786 return iterative_hash_template_arg (TRAIT_EXPR_TYPE2 (arg), val);
1789 val = iterative_hash_template_arg (BINFO_TYPE (BASELINK_BINFO (arg)),
1791 return iterative_hash_template_arg (DECL_NAME (get_first_fn (arg)),
1795 val = iterative_hash_template_arg (TREE_OPERAND (arg, 0), val);
1796 code = TREE_CODE (TREE_OPERAND (arg, 1));
1797 val = iterative_hash_object (code, val);
1798 return iterative_hash_template_arg (TREE_OPERAND (arg, 2), val);
1801 /* A lambda can't appear in a template arg, but don't crash on
1803 gcc_assert (seen_error ());
1807 case IMPLICIT_CONV_EXPR:
1808 case STATIC_CAST_EXPR:
1809 case REINTERPRET_CAST_EXPR:
1810 case CONST_CAST_EXPR:
1811 case DYNAMIC_CAST_EXPR:
1813 val = iterative_hash_template_arg (TREE_TYPE (arg), val);
1814 /* Now hash operands as usual. */
1824 if (alias_template_specialization_p (arg))
1826 // We want an alias specialization that survived strip_typedefs
1827 // to hash differently from its TYPE_CANONICAL, to avoid hash
1828 // collisions that compare as different in template_args_equal.
1829 // These could be dependent specializations that strip_typedefs
1830 // left alone, or untouched specializations because
1831 // coerce_template_parms returns the unconverted template
1832 // arguments if it sees incomplete argument packs.
1833 tree ti = TYPE_TEMPLATE_INFO (arg);
1834 return hash_tmpl_and_args (TI_TEMPLATE (ti), TI_ARGS (ti));
1836 if (TYPE_CANONICAL (arg))
1837 return iterative_hash_object (TYPE_HASH (TYPE_CANONICAL (arg)),
1839 else if (TREE_CODE (arg) == DECLTYPE_TYPE)
1840 return iterative_hash_template_arg (DECLTYPE_TYPE_EXPR (arg), val);
1841 /* Otherwise just compare the types during lookup. */
1844 case tcc_declaration:
1846 return iterative_hash_expr (arg, val);
1849 gcc_assert (IS_EXPR_CODE_CLASS (tclass));
1851 unsigned n = cp_tree_operand_length (arg);
1852 for (i = 0; i < n; ++i)
1853 val = iterative_hash_template_arg (TREE_OPERAND (arg, i), val);
1861 /* Unregister the specialization SPEC as a specialization of TMPL.
1862 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1863 if the SPEC was listed as a specialization of TMPL.
1865 Note that SPEC has been ggc_freed, so we can't look inside it. */
1868 reregister_specialization (tree spec, tree tinfo, tree new_spec)
1873 elt.tmpl = most_general_template (TI_TEMPLATE (tinfo));
1874 elt.args = TI_ARGS (tinfo);
1875 elt.spec = NULL_TREE;
1877 entry = decl_specializations->find (&elt);
1880 gcc_assert (entry->spec == spec || entry->spec == new_spec);
1881 gcc_assert (new_spec != NULL_TREE);
1882 entry->spec = new_spec;
1889 /* Like register_specialization, but for local declarations. We are
1890 registering SPEC, an instantiation of TMPL. */
1893 register_local_specialization (tree spec, tree tmpl)
1895 local_specializations->put (tmpl, spec);
1898 /* TYPE is a class type. Returns true if TYPE is an explicitly
1899 specialized class. */
1902 explicit_class_specialization_p (tree type)
1904 if (!CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
1906 return !uses_template_parms (CLASSTYPE_TI_ARGS (type));
1909 /* Print the list of functions at FNS, going through all the overloads
1910 for each element of the list. Alternatively, FNS can not be a
1911 TREE_LIST, in which case it will be printed together with all the
1914 MORE and *STR should respectively be FALSE and NULL when the function
1915 is called from the outside. They are used internally on recursive
1916 calls. print_candidates manages the two parameters and leaves NULL
1917 in *STR when it ends. */
1920 print_candidates_1 (tree fns, bool more, const char **str)
1923 char *spaces = NULL;
1925 for (fn = fns; fn; fn = OVL_NEXT (fn))
1926 if (TREE_CODE (fn) == TREE_LIST)
1928 for (fn2 = fn; fn2 != NULL_TREE; fn2 = TREE_CHAIN (fn2))
1929 print_candidates_1 (TREE_VALUE (fn2),
1930 TREE_CHAIN (fn2) || more, str);
1934 tree cand = OVL_CURRENT (fn);
1937 /* Pick the prefix string. */
1938 if (!more && !OVL_NEXT (fns))
1940 inform (DECL_SOURCE_LOCATION (cand),
1941 "candidate is: %#D", cand);
1945 *str = _("candidates are:");
1946 spaces = get_spaces (*str);
1948 inform (DECL_SOURCE_LOCATION (cand), "%s %#D", *str, cand);
1949 *str = spaces ? spaces : *str;
1959 /* Print the list of candidate FNS in an error message. FNS can also
1960 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1963 print_candidates (tree fns)
1965 const char *str = NULL;
1966 print_candidates_1 (fns, false, &str);
1967 gcc_assert (str == NULL);
1970 /* Get a (possibly) constrained template declaration for the
1971 purpose of ordering candidates. */
1973 get_template_for_ordering (tree list)
1975 gcc_assert (TREE_CODE (list) == TREE_LIST);
1976 tree f = TREE_VALUE (list);
1977 if (tree ti = DECL_TEMPLATE_INFO (f))
1978 return TI_TEMPLATE (ti);
1982 /* Among candidates having the same signature, return the
1983 most constrained or NULL_TREE if there is no best candidate.
1984 If the signatures of candidates vary (e.g., template
1985 specialization vs. member function), then there can be no
1988 Note that we don't compare constraints on the functions
1989 themselves, but rather those of their templates. */
1991 most_constrained_function (tree candidates)
1993 // Try to find the best candidate in a first pass.
1994 tree champ = candidates;
1995 for (tree c = TREE_CHAIN (champ); c; c = TREE_CHAIN (c))
1997 int winner = more_constrained (get_template_for_ordering (champ),
1998 get_template_for_ordering (c));
2000 champ = c; // The candidate is more constrained
2001 else if (winner == 0)
2002 return NULL_TREE; // Neither is more constrained
2005 // Verify that the champ is better than previous candidates.
2006 for (tree c = candidates; c != champ; c = TREE_CHAIN (c)) {
2007 if (!more_constrained (get_template_for_ordering (champ),
2008 get_template_for_ordering (c)))
2016 /* Returns the template (one of the functions given by TEMPLATE_ID)
2017 which can be specialized to match the indicated DECL with the
2018 explicit template args given in TEMPLATE_ID. The DECL may be
2019 NULL_TREE if none is available. In that case, the functions in
2020 TEMPLATE_ID are non-members.
2022 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
2023 specialization of a member template.
2025 The TEMPLATE_COUNT is the number of references to qualifying
2026 template classes that appeared in the name of the function. See
2027 check_explicit_specialization for a more accurate description.
2029 TSK indicates what kind of template declaration (if any) is being
2030 declared. TSK_TEMPLATE indicates that the declaration given by
2031 DECL, though a FUNCTION_DECL, has template parameters, and is
2032 therefore a template function.
2034 The template args (those explicitly specified and those deduced)
2035 are output in a newly created vector *TARGS_OUT.
2037 If it is impossible to determine the result, an error message is
2038 issued. The error_mark_node is returned to indicate failure. */
2041 determine_specialization (tree template_id,
2044 int need_member_template,
2050 tree explicit_targs;
2051 tree candidates = NULL_TREE;
2053 /* A TREE_LIST of templates of which DECL may be a specialization.
2054 The TREE_VALUE of each node is a TEMPLATE_DECL. The
2055 corresponding TREE_PURPOSE is the set of template arguments that,
2056 when used to instantiate the template, would produce a function
2057 with the signature of DECL. */
2058 tree templates = NULL_TREE;
2060 cp_binding_level *b;
2062 *targs_out = NULL_TREE;
2064 if (template_id == error_mark_node || decl == error_mark_node)
2065 return error_mark_node;
2067 /* We shouldn't be specializing a member template of an
2068 unspecialized class template; we already gave an error in
2069 check_specialization_scope, now avoid crashing. */
2070 if (template_count && DECL_CLASS_SCOPE_P (decl)
2071 && template_class_depth (DECL_CONTEXT (decl)) > 0)
2073 gcc_assert (errorcount);
2074 return error_mark_node;
2077 fns = TREE_OPERAND (template_id, 0);
2078 explicit_targs = TREE_OPERAND (template_id, 1);
2080 if (fns == error_mark_node)
2081 return error_mark_node;
2083 /* Check for baselinks. */
2084 if (BASELINK_P (fns))
2085 fns = BASELINK_FUNCTIONS (fns);
2087 if (TREE_CODE (decl) == FUNCTION_DECL && !is_overloaded_fn (fns))
2089 error ("%qD is not a function template", fns);
2090 return error_mark_node;
2092 else if (VAR_P (decl) && !variable_template_p (fns))
2094 error ("%qD is not a variable template", fns);
2095 return error_mark_node;
2098 /* Count the number of template headers specified for this
2101 for (b = current_binding_level;
2102 b->kind == sk_template_parms;
2106 tree orig_fns = fns;
2108 if (variable_template_p (fns))
2110 tree parms = INNERMOST_TEMPLATE_PARMS (DECL_TEMPLATE_PARMS (fns));
2111 targs = coerce_template_parms (parms, explicit_targs, fns,
2112 tf_warning_or_error,
2113 /*req_all*/true, /*use_defarg*/true);
2114 if (targs != error_mark_node)
2115 templates = tree_cons (targs, fns, templates);
2117 else for (; fns; fns = OVL_NEXT (fns))
2119 tree fn = OVL_CURRENT (fns);
2121 if (TREE_CODE (fn) == TEMPLATE_DECL)
2123 tree decl_arg_types;
2127 /* In case of explicit specialization, we need to check if
2128 the number of template headers appearing in the specialization
2129 is correct. This is usually done in check_explicit_specialization,
2130 but the check done there cannot be exhaustive when specializing
2131 member functions. Consider the following code:
2133 template <> void A<int>::f(int);
2134 template <> template <> void A<int>::f(int);
2136 Assuming that A<int> is not itself an explicit specialization
2137 already, the first line specializes "f" which is a non-template
2138 member function, whilst the second line specializes "f" which
2139 is a template member function. So both lines are syntactically
2140 correct, and check_explicit_specialization does not reject
2143 Here, we can do better, as we are matching the specialization
2144 against the declarations. We count the number of template
2145 headers, and we check if they match TEMPLATE_COUNT + 1
2146 (TEMPLATE_COUNT is the number of qualifying template classes,
2147 plus there must be another header for the member template
2150 Notice that if header_count is zero, this is not a
2151 specialization but rather a template instantiation, so there
2152 is no check we can perform here. */
2153 if (header_count && header_count != template_count + 1)
2156 /* Check that the number of template arguments at the
2157 innermost level for DECL is the same as for FN. */
2158 if (current_binding_level->kind == sk_template_parms
2159 && !current_binding_level->explicit_spec_p
2160 && (TREE_VEC_LENGTH (DECL_INNERMOST_TEMPLATE_PARMS (fn))
2161 != TREE_VEC_LENGTH (INNERMOST_TEMPLATE_PARMS
2162 (current_template_parms))))
2165 /* DECL might be a specialization of FN. */
2166 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
2167 fn_arg_types = TYPE_ARG_TYPES (TREE_TYPE (fn));
2169 /* For a non-static member function, we need to make sure
2170 that the const qualification is the same. Since
2171 get_bindings does not try to merge the "this" parameter,
2172 we must do the comparison explicitly. */
2173 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
2174 && !same_type_p (TREE_VALUE (fn_arg_types),
2175 TREE_VALUE (decl_arg_types)))
2178 /* Skip the "this" parameter and, for constructors of
2179 classes with virtual bases, the VTT parameter. A
2180 full specialization of a constructor will have a VTT
2181 parameter, but a template never will. */
2183 = skip_artificial_parms_for (decl, decl_arg_types);
2185 = skip_artificial_parms_for (fn, fn_arg_types);
2187 /* Function templates cannot be specializations; there are
2188 no partial specializations of functions. Therefore, if
2189 the type of DECL does not match FN, there is no
2192 Note that it should never be the case that we have both
2193 candidates added here, and for regular member functions
2195 if (tsk == tsk_template)
2197 if (compparms (fn_arg_types, decl_arg_types))
2198 candidates = tree_cons (NULL_TREE, fn, candidates);
2202 /* See whether this function might be a specialization of this
2203 template. Suppress access control because we might be trying
2204 to make this specialization a friend, and we have already done
2205 access control for the declaration of the specialization. */
2206 push_deferring_access_checks (dk_no_check);
2207 targs = get_bindings (fn, decl, explicit_targs, /*check_ret=*/true);
2208 pop_deferring_access_checks ();
2211 /* We cannot deduce template arguments that when used to
2212 specialize TMPL will produce DECL. */
2215 /* Remove, from the set of candidates, all those functions
2216 whose constraints are not satisfied. */
2217 if (flag_concepts && !constraints_satisfied_p (fn, targs))
2220 // Then, try to form the new function type.
2221 insttype = tsubst (TREE_TYPE (fn), targs, tf_none, NULL_TREE);
2222 if (insttype == error_mark_node)
2225 = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (insttype));
2226 if (!compparms (fn_arg_types, decl_arg_types))
2229 /* Save this template, and the arguments deduced. */
2230 templates = tree_cons (targs, fn, templates);
2232 else if (need_member_template)
2233 /* FN is an ordinary member function, and we need a
2234 specialization of a member template. */
2236 else if (TREE_CODE (fn) != FUNCTION_DECL)
2237 /* We can get IDENTIFIER_NODEs here in certain erroneous
2240 else if (!DECL_FUNCTION_MEMBER_P (fn))
2241 /* This is just an ordinary non-member function. Nothing can
2242 be a specialization of that. */
2244 else if (DECL_ARTIFICIAL (fn))
2245 /* Cannot specialize functions that are created implicitly. */
2249 tree decl_arg_types;
2251 /* This is an ordinary member function. However, since
2252 we're here, we can assume its enclosing class is a
2253 template class. For example,
2255 template <typename T> struct S { void f(); };
2256 template <> void S<int>::f() {}
2258 Here, S<int>::f is a non-template, but S<int> is a
2259 template class. If FN has the same type as DECL, we
2260 might be in business. */
2262 if (!DECL_TEMPLATE_INFO (fn))
2263 /* Its enclosing class is an explicit specialization
2264 of a template class. This is not a candidate. */
2267 if (!same_type_p (TREE_TYPE (TREE_TYPE (decl)),
2268 TREE_TYPE (TREE_TYPE (fn))))
2269 /* The return types differ. */
2272 /* Adjust the type of DECL in case FN is a static member. */
2273 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
2274 if (DECL_STATIC_FUNCTION_P (fn)
2275 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2276 decl_arg_types = TREE_CHAIN (decl_arg_types);
2278 if (!compparms (TYPE_ARG_TYPES (TREE_TYPE (fn)),
2282 // If the deduced arguments do not satisfy the constraints,
2283 // this is not a candidate.
2284 if (flag_concepts && !constraints_satisfied_p (fn))
2287 // Add the candidate.
2288 candidates = tree_cons (NULL_TREE, fn, candidates);
2292 if (templates && TREE_CHAIN (templates))
2298 It is possible for a specialization with a given function
2299 signature to be instantiated from more than one function
2300 template. In such cases, explicit specification of the
2301 template arguments must be used to uniquely identify the
2302 function template specialization being specialized.
2304 Note that here, there's no suggestion that we're supposed to
2305 determine which of the candidate templates is most
2306 specialized. However, we, also have:
2310 Partial ordering of overloaded function template
2311 declarations is used in the following contexts to select
2312 the function template to which a function template
2313 specialization refers:
2315 -- when an explicit specialization refers to a function
2318 So, we do use the partial ordering rules, at least for now.
2319 This extension can only serve to make invalid programs valid,
2320 so it's safe. And, there is strong anecdotal evidence that
2321 the committee intended the partial ordering rules to apply;
2322 the EDG front end has that behavior, and John Spicer claims
2323 that the committee simply forgot to delete the wording in
2324 [temp.expl.spec]. */
2325 tree tmpl = most_specialized_instantiation (templates);
2326 if (tmpl != error_mark_node)
2329 TREE_CHAIN (templates) = NULL_TREE;
2333 // Concepts allows multiple declarations of member functions
2334 // with the same signature. Like above, we need to rely on
2335 // on the partial ordering of those candidates to determine which
2337 if (flag_concepts && candidates && TREE_CHAIN (candidates))
2339 if (tree cand = most_constrained_function (candidates))
2342 TREE_CHAIN (cand) = NULL_TREE;
2346 if (templates == NULL_TREE && candidates == NULL_TREE)
2348 error ("template-id %qD for %q+D does not match any template "
2349 "declaration", template_id, decl);
2350 if (header_count && header_count != template_count + 1)
2351 inform (input_location, "saw %d %<template<>%>, need %d for "
2352 "specializing a member function template",
2353 header_count, template_count + 1);
2355 print_candidates (orig_fns);
2356 return error_mark_node;
2358 else if ((templates && TREE_CHAIN (templates))
2359 || (candidates && TREE_CHAIN (candidates))
2360 || (templates && candidates))
2362 error ("ambiguous template specialization %qD for %q+D",
2364 candidates = chainon (candidates, templates);
2365 print_candidates (candidates);
2366 return error_mark_node;
2369 /* We have one, and exactly one, match. */
2372 tree fn = TREE_VALUE (candidates);
2373 *targs_out = copy_node (DECL_TI_ARGS (fn));
2375 // Propagate the candidate's constraints to the declaration.
2376 set_constraints (decl, get_constraints (fn));
2378 /* DECL is a re-declaration or partial instantiation of a template
2380 if (TREE_CODE (fn) == TEMPLATE_DECL)
2382 /* It was a specialization of an ordinary member function in a
2384 return DECL_TI_TEMPLATE (fn);
2387 /* It was a specialization of a template. */
2388 targs = DECL_TI_ARGS (DECL_TEMPLATE_RESULT (TREE_VALUE (templates)));
2389 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (targs))
2391 *targs_out = copy_node (targs);
2392 SET_TMPL_ARGS_LEVEL (*targs_out,
2393 TMPL_ARGS_DEPTH (*targs_out),
2394 TREE_PURPOSE (templates));
2397 *targs_out = TREE_PURPOSE (templates);
2398 return TREE_VALUE (templates);
2401 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2402 but with the default argument values filled in from those in the
2406 copy_default_args_to_explicit_spec_1 (tree spec_types,
2409 tree new_spec_types;
2414 if (spec_types == void_list_node)
2415 return void_list_node;
2417 /* Substitute into the rest of the list. */
2419 copy_default_args_to_explicit_spec_1 (TREE_CHAIN (spec_types),
2420 TREE_CHAIN (tmpl_types));
2422 /* Add the default argument for this parameter. */
2423 return hash_tree_cons (TREE_PURPOSE (tmpl_types),
2424 TREE_VALUE (spec_types),
2428 /* DECL is an explicit specialization. Replicate default arguments
2429 from the template it specializes. (That way, code like:
2431 template <class T> void f(T = 3);
2432 template <> void f(double);
2435 works, as required.) An alternative approach would be to look up
2436 the correct default arguments at the call-site, but this approach
2437 is consistent with how implicit instantiations are handled. */
2440 copy_default_args_to_explicit_spec (tree decl)
2445 tree new_spec_types;
2449 tree object_type = NULL_TREE;
2450 tree in_charge = NULL_TREE;
2451 tree vtt = NULL_TREE;
2453 /* See if there's anything we need to do. */
2454 tmpl = DECL_TI_TEMPLATE (decl);
2455 tmpl_types = TYPE_ARG_TYPES (TREE_TYPE (DECL_TEMPLATE_RESULT (tmpl)));
2456 for (t = tmpl_types; t; t = TREE_CHAIN (t))
2457 if (TREE_PURPOSE (t))
2462 old_type = TREE_TYPE (decl);
2463 spec_types = TYPE_ARG_TYPES (old_type);
2465 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2467 /* Remove the this pointer, but remember the object's type for
2469 object_type = TREE_TYPE (TREE_VALUE (spec_types));
2470 spec_types = TREE_CHAIN (spec_types);
2471 tmpl_types = TREE_CHAIN (tmpl_types);
2473 if (DECL_HAS_IN_CHARGE_PARM_P (decl))
2475 /* DECL may contain more parameters than TMPL due to the extra
2476 in-charge parameter in constructors and destructors. */
2477 in_charge = spec_types;
2478 spec_types = TREE_CHAIN (spec_types);
2480 if (DECL_HAS_VTT_PARM_P (decl))
2483 spec_types = TREE_CHAIN (spec_types);
2487 /* Compute the merged default arguments. */
2489 copy_default_args_to_explicit_spec_1 (spec_types, tmpl_types);
2491 /* Compute the new FUNCTION_TYPE. */
2495 new_spec_types = hash_tree_cons (TREE_PURPOSE (vtt),
2500 /* Put the in-charge parameter back. */
2501 new_spec_types = hash_tree_cons (TREE_PURPOSE (in_charge),
2502 TREE_VALUE (in_charge),
2505 new_type = build_method_type_directly (object_type,
2506 TREE_TYPE (old_type),
2510 new_type = build_function_type (TREE_TYPE (old_type),
2512 new_type = cp_build_type_attribute_variant (new_type,
2513 TYPE_ATTRIBUTES (old_type));
2514 new_type = build_exception_variant (new_type,
2515 TYPE_RAISES_EXCEPTIONS (old_type));
2517 if (TYPE_HAS_LATE_RETURN_TYPE (old_type))
2518 TYPE_HAS_LATE_RETURN_TYPE (new_type) = 1;
2520 TREE_TYPE (decl) = new_type;
2523 /* Return the number of template headers we expect to see for a definition
2524 or specialization of CTYPE or one of its non-template members. */
2527 num_template_headers_for_class (tree ctype)
2529 int num_templates = 0;
2531 while (ctype && CLASS_TYPE_P (ctype))
2533 /* You're supposed to have one `template <...>' for every
2534 template class, but you don't need one for a full
2535 specialization. For example:
2537 template <class T> struct S{};
2538 template <> struct S<int> { void f(); };
2539 void S<int>::f () {}
2541 is correct; there shouldn't be a `template <>' for the
2542 definition of `S<int>::f'. */
2543 if (!CLASSTYPE_TEMPLATE_INFO (ctype))
2544 /* If CTYPE does not have template information of any
2545 kind, then it is not a template, nor is it nested
2546 within a template. */
2548 if (explicit_class_specialization_p (ctype))
2550 if (PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (ctype)))
2553 ctype = TYPE_CONTEXT (ctype);
2556 return num_templates;
2559 /* Do a simple sanity check on the template headers that precede the
2560 variable declaration DECL. */
2563 check_template_variable (tree decl)
2565 tree ctx = CP_DECL_CONTEXT (decl);
2566 int wanted = num_template_headers_for_class (ctx);
2567 if (DECL_LANG_SPECIFIC (decl) && DECL_TEMPLATE_INFO (decl)
2568 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (decl)))
2570 if (cxx_dialect < cxx14)
2571 pedwarn (DECL_SOURCE_LOCATION (decl), 0,
2572 "variable templates only available with "
2573 "-std=c++14 or -std=gnu++14");
2575 // Namespace-scope variable templates should have a template header.
2578 if (template_header_count > wanted)
2580 bool warned = pedwarn (DECL_SOURCE_LOCATION (decl), 0,
2581 "too many template headers for %D (should be %d)",
2583 if (warned && CLASS_TYPE_P (ctx)
2584 && CLASSTYPE_TEMPLATE_SPECIALIZATION (ctx))
2585 inform (DECL_SOURCE_LOCATION (decl),
2586 "members of an explicitly specialized class are defined "
2587 "without a template header");
2591 /* Check to see if the function just declared, as indicated in
2592 DECLARATOR, and in DECL, is a specialization of a function
2593 template. We may also discover that the declaration is an explicit
2594 instantiation at this point.
2596 Returns DECL, or an equivalent declaration that should be used
2597 instead if all goes well. Issues an error message if something is
2598 amiss. Returns error_mark_node if the error is not easily
2601 FLAGS is a bitmask consisting of the following flags:
2603 2: The function has a definition.
2604 4: The function is a friend.
2606 The TEMPLATE_COUNT is the number of references to qualifying
2607 template classes that appeared in the name of the function. For
2610 template <class T> struct S { void f(); };
2613 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2614 classes are not counted in the TEMPLATE_COUNT, so that in
2616 template <class T> struct S {};
2617 template <> struct S<int> { void f(); }
2618 template <> void S<int>::f();
2620 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2621 invalid; there should be no template <>.)
2623 If the function is a specialization, it is marked as such via
2624 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2625 is set up correctly, and it is added to the list of specializations
2626 for that template. */
2629 check_explicit_specialization (tree declarator,
2634 int have_def = flags & 2;
2635 int is_friend = flags & 4;
2636 bool is_concept = flags & 8;
2637 int specialization = 0;
2638 int explicit_instantiation = 0;
2639 int member_specialization = 0;
2640 tree ctype = DECL_CLASS_CONTEXT (decl);
2641 tree dname = DECL_NAME (decl);
2646 if (!processing_specialization)
2649 tsk = tsk_excessive_parms;
2652 tsk = current_tmpl_spec_kind (template_count);
2657 if (processing_specialization && !VAR_P (decl))
2660 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2662 else if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2665 /* This could be something like:
2667 template <class T> void f(T);
2668 class S { friend void f<>(int); } */
2672 /* This case handles bogus declarations like template <>
2673 template <class T> void f<int>(); */
2675 error ("template-id %qD in declaration of primary template",
2682 case tsk_invalid_member_spec:
2683 /* The error has already been reported in
2684 check_specialization_scope. */
2685 return error_mark_node;
2687 case tsk_invalid_expl_inst:
2688 error ("template parameter list used in explicit instantiation");
2694 error ("definition provided for explicit instantiation");
2696 explicit_instantiation = 1;
2699 case tsk_excessive_parms:
2700 case tsk_insufficient_parms:
2701 if (tsk == tsk_excessive_parms)
2702 error ("too many template parameter lists in declaration of %qD",
2704 else if (template_header_count)
2705 error("too few template parameter lists in declaration of %qD", decl);
2707 error("explicit specialization of %qD must be introduced by "
2708 "%<template <>%>", decl);
2713 error ("explicit specialization declared %<concept%>");
2715 if (VAR_P (decl) && TREE_CODE (declarator) != TEMPLATE_ID_EXPR)
2716 /* In cases like template<> constexpr bool v = true;
2717 We'll give an error in check_template_variable. */
2720 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2722 member_specialization = 1;
2728 if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2730 /* This case handles bogus declarations like template <>
2731 template <class T> void f<int>(); */
2733 if (!uses_template_parms (declarator))
2734 error ("template-id %qD in declaration of primary template",
2736 else if (variable_template_p (TREE_OPERAND (declarator, 0)))
2738 /* Partial specialization of variable template. */
2739 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2743 else if (cxx_dialect < cxx14)
2744 error ("non-type partial specialization %qD "
2745 "is not allowed", declarator);
2747 error ("non-class, non-variable partial specialization %qD "
2748 "is not allowed", declarator);
2753 if (ctype && CLASSTYPE_TEMPLATE_INSTANTIATION (ctype))
2754 /* This is a specialization of a member template, without
2755 specialization the containing class. Something like:
2757 template <class T> struct S {
2758 template <class U> void f (U);
2760 template <> template <class U> void S<int>::f(U) {}
2762 That's a specialization -- but of the entire template. */
2770 if ((specialization || member_specialization)
2771 /* This doesn't apply to variable templates. */
2772 && (TREE_CODE (TREE_TYPE (decl)) == FUNCTION_TYPE
2773 || TREE_CODE (TREE_TYPE (decl)) == METHOD_TYPE))
2775 tree t = TYPE_ARG_TYPES (TREE_TYPE (decl));
2776 for (; t; t = TREE_CHAIN (t))
2777 if (TREE_PURPOSE (t))
2779 permerror (input_location,
2780 "default argument specified in explicit specialization");
2785 if (specialization || member_specialization || explicit_instantiation)
2787 tree tmpl = NULL_TREE;
2788 tree targs = NULL_TREE;
2789 bool was_template_id = (TREE_CODE (declarator) == TEMPLATE_ID_EXPR);
2791 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2792 if (!was_template_id)
2796 gcc_assert (identifier_p (declarator));
2801 /* If there is no class context, the explicit instantiation
2802 must be at namespace scope. */
2803 gcc_assert (DECL_NAMESPACE_SCOPE_P (decl));
2805 /* Find the namespace binding, using the declaration
2807 fns = lookup_qualified_name (CP_DECL_CONTEXT (decl), dname,
2809 if (fns == error_mark_node)
2810 /* If lookup fails, look for a friend declaration so we can
2811 give a better diagnostic. */
2812 fns = lookup_qualified_name (CP_DECL_CONTEXT (decl), dname,
2813 /*type*/false, /*complain*/true,
2816 if (fns == error_mark_node || !is_overloaded_fn (fns))
2818 error ("%qD is not a template function", dname);
2819 fns = error_mark_node;
2823 declarator = lookup_template_function (fns, NULL_TREE);
2826 if (declarator == error_mark_node)
2827 return error_mark_node;
2829 if (ctype != NULL_TREE && TYPE_BEING_DEFINED (ctype))
2831 if (!explicit_instantiation)
2832 /* A specialization in class scope. This is invalid,
2833 but the error will already have been flagged by
2834 check_specialization_scope. */
2835 return error_mark_node;
2838 /* It's not valid to write an explicit instantiation in
2841 class C { template void f(); }
2843 This case is caught by the parser. However, on
2846 template class C { void f(); };
2848 (which is invalid) we can get here. The error will be
2855 else if (ctype != NULL_TREE
2856 && (identifier_p (TREE_OPERAND (declarator, 0))))
2858 // We'll match variable templates in start_decl.
2862 /* Find the list of functions in ctype that have the same
2863 name as the declared function. */
2864 tree name = TREE_OPERAND (declarator, 0);
2865 tree fns = NULL_TREE;
2868 if (constructor_name_p (name, ctype))
2870 int is_constructor = DECL_CONSTRUCTOR_P (decl);
2872 if (is_constructor ? !TYPE_HAS_USER_CONSTRUCTOR (ctype)
2873 : !CLASSTYPE_DESTRUCTORS (ctype))
2875 /* From [temp.expl.spec]:
2877 If such an explicit specialization for the member
2878 of a class template names an implicitly-declared
2879 special member function (clause _special_), the
2880 program is ill-formed.
2882 Similar language is found in [temp.explicit]. */
2883 error ("specialization of implicitly-declared special member function");
2884 return error_mark_node;
2887 name = is_constructor ? ctor_identifier : dtor_identifier;
2890 if (!DECL_CONV_FN_P (decl))
2892 idx = lookup_fnfields_1 (ctype, name);
2894 fns = (*CLASSTYPE_METHOD_VEC (ctype))[idx];
2898 vec<tree, va_gc> *methods;
2901 /* For a type-conversion operator, we cannot do a
2902 name-based lookup. We might be looking for `operator
2903 int' which will be a specialization of `operator T'.
2904 So, we find *all* the conversion operators, and then
2905 select from them. */
2908 methods = CLASSTYPE_METHOD_VEC (ctype);
2910 for (idx = CLASSTYPE_FIRST_CONVERSION_SLOT;
2911 methods->iterate (idx, &ovl);
2914 if (!DECL_CONV_FN_P (OVL_CURRENT (ovl)))
2915 /* There are no more conversion functions. */
2918 /* Glue all these conversion functions together
2919 with those we already have. */
2920 for (; ovl; ovl = OVL_NEXT (ovl))
2921 fns = ovl_cons (OVL_CURRENT (ovl), fns);
2925 if (fns == NULL_TREE)
2927 error ("no member function %qD declared in %qT", name, ctype);
2928 return error_mark_node;
2931 TREE_OPERAND (declarator, 0) = fns;
2934 /* Figure out what exactly is being specialized at this point.
2935 Note that for an explicit instantiation, even one for a
2936 member function, we cannot tell apriori whether the
2937 instantiation is for a member template, or just a member
2938 function of a template class. Even if a member template is
2939 being instantiated, the member template arguments may be
2940 elided if they can be deduced from the rest of the
2942 tmpl = determine_specialization (declarator, decl,
2944 member_specialization,
2948 if (!tmpl || tmpl == error_mark_node)
2949 /* We couldn't figure out what this declaration was
2951 return error_mark_node;
2954 if (!ctype && !was_template_id
2955 && (specialization || member_specialization
2956 || explicit_instantiation)
2957 && !is_associated_namespace (CP_DECL_CONTEXT (decl),
2958 CP_DECL_CONTEXT (tmpl)))
2959 error ("%qD is not declared in %qD",
2960 tmpl, current_namespace);
2961 else if (TREE_CODE (decl) == FUNCTION_DECL
2962 && DECL_HIDDEN_FRIEND_P (tmpl))
2964 if (pedwarn (DECL_SOURCE_LOCATION (decl), 0,
2965 "friend declaration %qD is not visible to "
2966 "explicit specialization", tmpl))
2967 inform (DECL_SOURCE_LOCATION (tmpl),
2968 "friend declaration here");
2971 tree gen_tmpl = most_general_template (tmpl);
2973 if (explicit_instantiation)
2975 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2976 is done by do_decl_instantiation later. */
2978 int arg_depth = TMPL_ARGS_DEPTH (targs);
2979 int parm_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
2981 if (arg_depth > parm_depth)
2983 /* If TMPL is not the most general template (for
2984 example, if TMPL is a friend template that is
2985 injected into namespace scope), then there will
2986 be too many levels of TARGS. Remove some of them
2991 new_targs = make_tree_vec (parm_depth);
2992 for (i = arg_depth - parm_depth; i < arg_depth; ++i)
2993 TREE_VEC_ELT (new_targs, i - (arg_depth - parm_depth))
2994 = TREE_VEC_ELT (targs, i);
2998 return instantiate_template (tmpl, targs, tf_error);
3001 /* If we thought that the DECL was a member function, but it
3002 turns out to be specializing a static member function,
3003 make DECL a static member function as well. */
3004 if (DECL_FUNCTION_TEMPLATE_P (tmpl)
3005 && DECL_STATIC_FUNCTION_P (tmpl)
3006 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
3007 revert_static_member_fn (decl);
3009 /* If this is a specialization of a member template of a
3010 template class, we want to return the TEMPLATE_DECL, not
3011 the specialization of it. */
3012 if (tsk == tsk_template && !was_template_id)
3014 tree result = DECL_TEMPLATE_RESULT (tmpl);
3015 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
3016 DECL_INITIAL (result) = NULL_TREE;
3020 DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl);
3021 DECL_SOURCE_LOCATION (result)
3022 = DECL_SOURCE_LOCATION (decl);
3023 /* We want to use the argument list specified in the
3024 definition, not in the original declaration. */
3025 DECL_ARGUMENTS (result) = DECL_ARGUMENTS (decl);
3026 for (parm = DECL_ARGUMENTS (result); parm;
3027 parm = DECL_CHAIN (parm))
3028 DECL_CONTEXT (parm) = result;
3030 return register_specialization (tmpl, gen_tmpl, targs,
3034 /* Set up the DECL_TEMPLATE_INFO for DECL. */
3035 DECL_TEMPLATE_INFO (decl) = build_template_info (tmpl, targs);
3037 if (was_template_id)
3038 TINFO_USED_TEMPLATE_ID (DECL_TEMPLATE_INFO (decl)) = true;
3040 /* Inherit default function arguments from the template
3041 DECL is specializing. */
3042 if (DECL_FUNCTION_TEMPLATE_P (tmpl))
3043 copy_default_args_to_explicit_spec (decl);
3045 /* This specialization has the same protection as the
3046 template it specializes. */
3047 TREE_PRIVATE (decl) = TREE_PRIVATE (gen_tmpl);
3048 TREE_PROTECTED (decl) = TREE_PROTECTED (gen_tmpl);
3050 /* 7.1.1-1 [dcl.stc]
3052 A storage-class-specifier shall not be specified in an
3053 explicit specialization...
3055 The parser rejects these, so unless action is taken here,
3056 explicit function specializations will always appear with
3059 The action recommended by the C++ CWG in response to C++
3060 defect report 605 is to make the storage class and linkage
3061 of the explicit specialization match the templated function:
3063 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
3065 if (tsk == tsk_expl_spec && DECL_FUNCTION_TEMPLATE_P (gen_tmpl))
3067 tree tmpl_func = DECL_TEMPLATE_RESULT (gen_tmpl);
3068 gcc_assert (TREE_CODE (tmpl_func) == FUNCTION_DECL);
3070 /* A concept cannot be specialized. */
3071 if (DECL_DECLARED_CONCEPT_P (tmpl_func))
3073 error ("explicit specialization of function concept %qD",
3075 return error_mark_node;
3078 /* This specialization has the same linkage and visibility as
3079 the function template it specializes. */
3080 TREE_PUBLIC (decl) = TREE_PUBLIC (tmpl_func);
3081 if (! TREE_PUBLIC (decl))
3083 DECL_INTERFACE_KNOWN (decl) = 1;
3084 DECL_NOT_REALLY_EXTERN (decl) = 1;
3086 DECL_THIS_STATIC (decl) = DECL_THIS_STATIC (tmpl_func);
3087 if (DECL_VISIBILITY_SPECIFIED (tmpl_func))
3089 DECL_VISIBILITY_SPECIFIED (decl) = 1;
3090 DECL_VISIBILITY (decl) = DECL_VISIBILITY (tmpl_func);
3094 /* If DECL is a friend declaration, declared using an
3095 unqualified name, the namespace associated with DECL may
3096 have been set incorrectly. For example, in:
3098 template <typename T> void f(T);
3100 struct S { friend void f<int>(int); }
3103 we will have set the DECL_CONTEXT for the friend
3104 declaration to N, rather than to the global namespace. */
3105 if (DECL_NAMESPACE_SCOPE_P (decl))
3106 DECL_CONTEXT (decl) = DECL_CONTEXT (tmpl);
3108 if (is_friend && !have_def)
3109 /* This is not really a declaration of a specialization.
3110 It's just the name of an instantiation. But, it's not
3111 a request for an instantiation, either. */
3112 SET_DECL_IMPLICIT_INSTANTIATION (decl);
3113 else if (TREE_CODE (decl) == FUNCTION_DECL)
3114 /* A specialization is not necessarily COMDAT. */
3115 DECL_COMDAT (decl) = (TREE_PUBLIC (decl)
3116 && DECL_DECLARED_INLINE_P (decl));
3117 else if (VAR_P (decl))
3118 DECL_COMDAT (decl) = false;
3120 /* If this is a full specialization, register it so that we can find
3121 it again. Partial specializations will be registered in
3122 process_partial_specialization. */
3123 if (!processing_template_decl)
3124 decl = register_specialization (decl, gen_tmpl, targs,
3127 /* A 'structor should already have clones. */
3128 gcc_assert (decl == error_mark_node
3129 || variable_template_p (tmpl)
3130 || !(DECL_CONSTRUCTOR_P (decl)
3131 || DECL_DESTRUCTOR_P (decl))
3132 || DECL_CLONED_FUNCTION_P (DECL_CHAIN (decl)));
3139 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
3140 parameters. These are represented in the same format used for
3141 DECL_TEMPLATE_PARMS. */
3144 comp_template_parms (const_tree parms1, const_tree parms2)
3149 if (parms1 == parms2)
3152 for (p1 = parms1, p2 = parms2;
3153 p1 != NULL_TREE && p2 != NULL_TREE;
3154 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2))
3156 tree t1 = TREE_VALUE (p1);
3157 tree t2 = TREE_VALUE (p2);
3160 gcc_assert (TREE_CODE (t1) == TREE_VEC);
3161 gcc_assert (TREE_CODE (t2) == TREE_VEC);
3163 if (TREE_VEC_LENGTH (t1) != TREE_VEC_LENGTH (t2))
3166 for (i = 0; i < TREE_VEC_LENGTH (t2); ++i)
3168 tree parm1 = TREE_VALUE (TREE_VEC_ELT (t1, i));
3169 tree parm2 = TREE_VALUE (TREE_VEC_ELT (t2, i));
3171 /* If either of the template parameters are invalid, assume
3172 they match for the sake of error recovery. */
3173 if (error_operand_p (parm1) || error_operand_p (parm2))
3176 if (TREE_CODE (parm1) != TREE_CODE (parm2))
3179 if (TREE_CODE (parm1) == TEMPLATE_TYPE_PARM
3180 && (TEMPLATE_TYPE_PARAMETER_PACK (parm1)
3181 == TEMPLATE_TYPE_PARAMETER_PACK (parm2)))
3183 else if (!same_type_p (TREE_TYPE (parm1), TREE_TYPE (parm2)))
3188 if ((p1 != NULL_TREE) != (p2 != NULL_TREE))
3189 /* One set of parameters has more parameters lists than the
3196 /* Determine whether PARM is a parameter pack. */
3199 template_parameter_pack_p (const_tree parm)
3201 /* Determine if we have a non-type template parameter pack. */
3202 if (TREE_CODE (parm) == PARM_DECL)
3203 return (DECL_TEMPLATE_PARM_P (parm)
3204 && TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)));
3205 if (TREE_CODE (parm) == TEMPLATE_PARM_INDEX)
3206 return TEMPLATE_PARM_PARAMETER_PACK (parm);
3208 /* If this is a list of template parameters, we could get a
3209 TYPE_DECL or a TEMPLATE_DECL. */
3210 if (TREE_CODE (parm) == TYPE_DECL || TREE_CODE (parm) == TEMPLATE_DECL)
3211 parm = TREE_TYPE (parm);
3213 /* Otherwise it must be a type template parameter. */
3214 return ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
3215 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM)
3216 && TEMPLATE_TYPE_PARAMETER_PACK (parm));
3219 /* Determine if T is a function parameter pack. */
3222 function_parameter_pack_p (const_tree t)
3224 if (t && TREE_CODE (t) == PARM_DECL)
3225 return DECL_PACK_P (t);
3229 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
3230 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
3233 get_function_template_decl (const_tree primary_func_tmpl_inst)
3235 if (! primary_func_tmpl_inst
3236 || TREE_CODE (primary_func_tmpl_inst) != FUNCTION_DECL
3237 || ! primary_template_instantiation_p (primary_func_tmpl_inst))
3240 return DECL_TEMPLATE_RESULT (DECL_TI_TEMPLATE (primary_func_tmpl_inst));
3243 /* Return true iff the function parameter PARAM_DECL was expanded
3244 from the function parameter pack PACK. */
3247 function_parameter_expanded_from_pack_p (tree param_decl, tree pack)
3249 if (DECL_ARTIFICIAL (param_decl)
3250 || !function_parameter_pack_p (pack))
3253 /* The parameter pack and its pack arguments have the same
3255 return DECL_PARM_INDEX (pack) == DECL_PARM_INDEX (param_decl);
3258 /* Determine whether ARGS describes a variadic template args list,
3259 i.e., one that is terminated by a template argument pack. */
3262 template_args_variadic_p (tree args)
3267 if (args == NULL_TREE)
3270 args = INNERMOST_TEMPLATE_ARGS (args);
3271 nargs = TREE_VEC_LENGTH (args);
3276 last_parm = TREE_VEC_ELT (args, nargs - 1);
3278 return ARGUMENT_PACK_P (last_parm);
3281 /* Generate a new name for the parameter pack name NAME (an
3282 IDENTIFIER_NODE) that incorporates its */
3285 make_ith_pack_parameter_name (tree name, int i)
3287 /* Munge the name to include the parameter index. */
3288 #define NUMBUF_LEN 128
3289 char numbuf[NUMBUF_LEN];
3293 if (name == NULL_TREE)
3295 snprintf (numbuf, NUMBUF_LEN, "%i", i);
3296 newname_len = IDENTIFIER_LENGTH (name)
3297 + strlen (numbuf) + 2;
3298 newname = (char*)alloca (newname_len);
3299 snprintf (newname, newname_len,
3300 "%s#%i", IDENTIFIER_POINTER (name), i);
3301 return get_identifier (newname);
3304 /* Return true if T is a primary function, class or alias template
3308 primary_template_instantiation_p (const_tree t)
3313 if (TREE_CODE (t) == FUNCTION_DECL)
3314 return DECL_LANG_SPECIFIC (t)
3315 && DECL_TEMPLATE_INSTANTIATION (t)
3316 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (t));
3317 else if (CLASS_TYPE_P (t) && !TYPE_DECL_ALIAS_P (TYPE_NAME (t)))
3318 return CLASSTYPE_TEMPLATE_INSTANTIATION (t)
3319 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (t));
3320 else if (alias_template_specialization_p (t))
3325 /* Return true if PARM is a template template parameter. */
3328 template_template_parameter_p (const_tree parm)
3330 return DECL_TEMPLATE_TEMPLATE_PARM_P (parm);
3333 /* Return true iff PARM is a DECL representing a type template
3337 template_type_parameter_p (const_tree parm)
3340 && (TREE_CODE (parm) == TYPE_DECL
3341 || TREE_CODE (parm) == TEMPLATE_DECL)
3342 && DECL_TEMPLATE_PARM_P (parm));
3345 /* Return the template parameters of T if T is a
3346 primary template instantiation, NULL otherwise. */
3349 get_primary_template_innermost_parameters (const_tree t)
3351 tree parms = NULL, template_info = NULL;
3353 if ((template_info = get_template_info (t))
3354 && primary_template_instantiation_p (t))
3355 parms = INNERMOST_TEMPLATE_PARMS
3356 (DECL_TEMPLATE_PARMS (TI_TEMPLATE (template_info)));
3361 /* Return the template parameters of the LEVELth level from the full list
3362 of template parameters PARMS. */
3365 get_template_parms_at_level (tree parms, int level)
3369 || TREE_CODE (parms) != TREE_LIST
3370 || level > TMPL_PARMS_DEPTH (parms))
3373 for (p = parms; p; p = TREE_CHAIN (p))
3374 if (TMPL_PARMS_DEPTH (p) == level)
3380 /* Returns the template arguments of T if T is a template instantiation,
3384 get_template_innermost_arguments (const_tree t)
3386 tree args = NULL, template_info = NULL;
3388 if ((template_info = get_template_info (t))
3389 && TI_ARGS (template_info))
3390 args = INNERMOST_TEMPLATE_ARGS (TI_ARGS (template_info));
3395 /* Return the argument pack elements of T if T is a template argument pack,
3399 get_template_argument_pack_elems (const_tree t)
3401 if (TREE_CODE (t) != TYPE_ARGUMENT_PACK
3402 && TREE_CODE (t) != NONTYPE_ARGUMENT_PACK)
3405 return ARGUMENT_PACK_ARGS (t);
3408 /* Structure used to track the progress of find_parameter_packs_r. */
3409 struct find_parameter_pack_data
3411 /* TREE_LIST that will contain all of the parameter packs found by
3413 tree* parameter_packs;
3415 /* Set of AST nodes that have been visited by the traversal. */
3416 hash_set<tree> *visited;
3418 /* True iff we're making a type pack expansion. */
3419 bool type_pack_expansion_p;
3422 /* Identifies all of the argument packs that occur in a template
3423 argument and appends them to the TREE_LIST inside DATA, which is a
3424 find_parameter_pack_data structure. This is a subroutine of
3425 make_pack_expansion and uses_parameter_packs. */
3427 find_parameter_packs_r (tree *tp, int *walk_subtrees, void* data)
3430 struct find_parameter_pack_data* ppd =
3431 (struct find_parameter_pack_data*)data;
3432 bool parameter_pack_p = false;
3434 /* Handle type aliases/typedefs. */
3435 if (TYPE_ALIAS_P (t))
3437 if (TYPE_TEMPLATE_INFO (t))
3438 cp_walk_tree (&TYPE_TI_ARGS (t),
3439 &find_parameter_packs_r,
3445 /* Identify whether this is a parameter pack or not. */
3446 switch (TREE_CODE (t))
3448 case TEMPLATE_PARM_INDEX:
3449 if (TEMPLATE_PARM_PARAMETER_PACK (t))
3450 parameter_pack_p = true;
3453 case TEMPLATE_TYPE_PARM:
3454 t = TYPE_MAIN_VARIANT (t);
3455 case TEMPLATE_TEMPLATE_PARM:
3456 /* If the placeholder appears in the decl-specifier-seq of a function
3457 parameter pack (14.6.3), or the type-specifier-seq of a type-id that
3458 is a pack expansion, the invented template parameter is a template
3460 if (ppd->type_pack_expansion_p && is_auto_or_concept (t))
3461 TEMPLATE_TYPE_PARAMETER_PACK (t) = true;
3462 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
3463 parameter_pack_p = true;
3468 if (DECL_PACK_P (t))
3470 /* We don't want to walk into the type of a PARM_DECL,
3471 because we don't want to see the type parameter pack. */
3473 parameter_pack_p = true;
3477 /* Look through a lambda capture proxy to the field pack. */
3479 if (DECL_HAS_VALUE_EXPR_P (t))
3481 tree v = DECL_VALUE_EXPR (t);
3483 &find_parameter_packs_r,
3487 else if (variable_template_specialization_p (t))
3489 cp_walk_tree (&DECL_TI_ARGS (t),
3490 find_parameter_packs_r,
3497 parameter_pack_p = true;
3500 /* Not a parameter pack. */
3504 if (parameter_pack_p)
3506 /* Add this parameter pack to the list. */
3507 *ppd->parameter_packs = tree_cons (NULL_TREE, t, *ppd->parameter_packs);
3511 cp_walk_tree (&TYPE_CONTEXT (t),
3512 &find_parameter_packs_r, ppd, ppd->visited);
3514 /* This switch statement will return immediately if we don't find a
3516 switch (TREE_CODE (t))
3518 case TEMPLATE_PARM_INDEX:
3521 case BOUND_TEMPLATE_TEMPLATE_PARM:
3522 /* Check the template itself. */
3523 cp_walk_tree (&TREE_TYPE (TYPE_TI_TEMPLATE (t)),
3524 &find_parameter_packs_r, ppd, ppd->visited);
3525 /* Check the template arguments. */
3526 cp_walk_tree (&TYPE_TI_ARGS (t), &find_parameter_packs_r, ppd,
3531 case TEMPLATE_TYPE_PARM:
3532 case TEMPLATE_TEMPLATE_PARM:
3539 if (TYPE_PTRMEMFUNC_P (t))
3545 if (TYPE_TEMPLATE_INFO (t))
3546 cp_walk_tree (&TYPE_TI_ARGS (t),
3547 &find_parameter_packs_r, ppd, ppd->visited);
3554 cp_walk_tree (&TREE_TYPE (t),
3555 &find_parameter_packs_r, ppd, ppd->visited);
3559 cp_walk_tree (&TYPENAME_TYPE_FULLNAME (t), &find_parameter_packs_r,
3564 case TYPE_PACK_EXPANSION:
3565 case EXPR_PACK_EXPANSION:
3570 cp_walk_tree (&TYPE_MAX_VALUE (t), &find_parameter_packs_r,
3575 case IDENTIFIER_NODE:
3576 cp_walk_tree (&TREE_TYPE (t), &find_parameter_packs_r, ppd,
3583 /* When traversing a DECLTYPE_TYPE_EXPR, we need to set
3584 type_pack_expansion_p to false so that any placeholders
3585 within the expression don't get marked as parameter packs. */
3586 bool type_pack_expansion_p = ppd->type_pack_expansion_p;
3587 ppd->type_pack_expansion_p = false;
3588 cp_walk_tree (&DECLTYPE_TYPE_EXPR (t), &find_parameter_packs_r,
3590 ppd->type_pack_expansion_p = type_pack_expansion_p;
3602 /* Determines if the expression or type T uses any parameter packs. */
3604 uses_parameter_packs (tree t)
3606 tree parameter_packs = NULL_TREE;
3607 struct find_parameter_pack_data ppd;
3608 ppd.parameter_packs = ¶meter_packs;
3609 ppd.visited = new hash_set<tree>;
3610 ppd.type_pack_expansion_p = false;
3611 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
3613 return parameter_packs != NULL_TREE;
3616 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3617 representation a base-class initializer into a parameter pack
3618 expansion. If all goes well, the resulting node will be an
3619 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3622 make_pack_expansion (tree arg)
3625 tree parameter_packs = NULL_TREE;
3626 bool for_types = false;
3627 struct find_parameter_pack_data ppd;
3629 if (!arg || arg == error_mark_node)
3632 if (TREE_CODE (arg) == TREE_LIST && TREE_PURPOSE (arg))
3634 /* A TREE_LIST with a non-null TREE_PURPOSE is for a base
3635 class initializer. In this case, the TREE_PURPOSE will be a
3636 _TYPE node (representing the base class expansion we're
3637 initializing) and the TREE_VALUE will be a TREE_LIST
3638 containing the initialization arguments.
3640 The resulting expansion looks somewhat different from most
3641 expansions. Rather than returning just one _EXPANSION, we
3642 return a TREE_LIST whose TREE_PURPOSE is a
3643 TYPE_PACK_EXPANSION containing the bases that will be
3644 initialized. The TREE_VALUE will be identical to the
3645 original TREE_VALUE, which is a list of arguments that will
3646 be passed to each base. We do not introduce any new pack
3647 expansion nodes into the TREE_VALUE (although it is possible
3648 that some already exist), because the TREE_PURPOSE and
3649 TREE_VALUE all need to be expanded together with the same
3650 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3651 resulting TREE_PURPOSE will mention the parameter packs in
3652 both the bases and the arguments to the bases. */
3655 tree parameter_packs = NULL_TREE;
3657 /* Determine which parameter packs will be used by the base
3659 ppd.visited = new hash_set<tree>;
3660 ppd.parameter_packs = ¶meter_packs;
3661 ppd.type_pack_expansion_p = true;
3662 gcc_assert (TYPE_P (TREE_PURPOSE (arg)));
3663 cp_walk_tree (&TREE_PURPOSE (arg), &find_parameter_packs_r,
3666 if (parameter_packs == NULL_TREE)
3668 error ("base initializer expansion %<%T%> contains no parameter packs", arg);
3670 return error_mark_node;
3673 if (TREE_VALUE (arg) != void_type_node)
3675 /* Collect the sets of parameter packs used in each of the
3676 initialization arguments. */
3677 for (value = TREE_VALUE (arg); value; value = TREE_CHAIN (value))
3679 /* Determine which parameter packs will be expanded in this
3681 cp_walk_tree (&TREE_VALUE (value), &find_parameter_packs_r,
3688 /* Create the pack expansion type for the base type. */
3689 purpose = cxx_make_type (TYPE_PACK_EXPANSION);
3690 SET_PACK_EXPANSION_PATTERN (purpose, TREE_PURPOSE (arg));
3691 PACK_EXPANSION_PARAMETER_PACKS (purpose) = parameter_packs;
3693 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3694 they will rarely be compared to anything. */
3695 SET_TYPE_STRUCTURAL_EQUALITY (purpose);
3697 return tree_cons (purpose, TREE_VALUE (arg), NULL_TREE);
3700 if (TYPE_P (arg) || TREE_CODE (arg) == TEMPLATE_DECL)
3703 /* Build the PACK_EXPANSION_* node. */
3705 ? cxx_make_type (TYPE_PACK_EXPANSION)
3706 : make_node (EXPR_PACK_EXPANSION);
3707 SET_PACK_EXPANSION_PATTERN (result, arg);
3708 if (TREE_CODE (result) == EXPR_PACK_EXPANSION)
3710 /* Propagate type and const-expression information. */
3711 TREE_TYPE (result) = TREE_TYPE (arg);
3712 TREE_CONSTANT (result) = TREE_CONSTANT (arg);
3713 /* Mark this read now, since the expansion might be length 0. */
3714 mark_exp_read (arg);
3717 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3718 they will rarely be compared to anything. */
3719 SET_TYPE_STRUCTURAL_EQUALITY (result);
3721 /* Determine which parameter packs will be expanded. */
3722 ppd.parameter_packs = ¶meter_packs;
3723 ppd.visited = new hash_set<tree>;
3724 ppd.type_pack_expansion_p = TYPE_P (arg);
3725 cp_walk_tree (&arg, &find_parameter_packs_r, &ppd, ppd.visited);
3728 /* Make sure we found some parameter packs. */
3729 if (parameter_packs == NULL_TREE)
3732 error ("expansion pattern %<%T%> contains no argument packs", arg);
3734 error ("expansion pattern %<%E%> contains no argument packs", arg);
3735 return error_mark_node;
3737 PACK_EXPANSION_PARAMETER_PACKS (result) = parameter_packs;
3739 PACK_EXPANSION_LOCAL_P (result) = at_function_scope_p ();
3744 /* Checks T for any "bare" parameter packs, which have not yet been
3745 expanded, and issues an error if any are found. This operation can
3746 only be done on full expressions or types (e.g., an expression
3747 statement, "if" condition, etc.), because we could have expressions like:
3749 foo(f(g(h(args)))...)
3751 where "args" is a parameter pack. check_for_bare_parameter_packs
3752 should not be called for the subexpressions args, h(args),
3753 g(h(args)), or f(g(h(args))), because we would produce erroneous
3756 Returns TRUE and emits an error if there were bare parameter packs,
3757 returns FALSE otherwise. */
3759 check_for_bare_parameter_packs (tree t)
3761 tree parameter_packs = NULL_TREE;
3762 struct find_parameter_pack_data ppd;
3764 if (!processing_template_decl || !t || t == error_mark_node)
3767 if (TREE_CODE (t) == TYPE_DECL)
3770 ppd.parameter_packs = ¶meter_packs;
3771 ppd.visited = new hash_set<tree>;
3772 ppd.type_pack_expansion_p = false;
3773 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
3776 if (parameter_packs)
3778 error ("parameter packs not expanded with %<...%>:");
3779 while (parameter_packs)
3781 tree pack = TREE_VALUE (parameter_packs);
3782 tree name = NULL_TREE;
3784 if (TREE_CODE (pack) == TEMPLATE_TYPE_PARM
3785 || TREE_CODE (pack) == TEMPLATE_TEMPLATE_PARM)
3786 name = TYPE_NAME (pack);
3787 else if (TREE_CODE (pack) == TEMPLATE_PARM_INDEX)
3788 name = DECL_NAME (TEMPLATE_PARM_DECL (pack));
3790 name = DECL_NAME (pack);
3793 inform (input_location, " %qD", name);
3795 inform (input_location, " <anonymous>");
3797 parameter_packs = TREE_CHAIN (parameter_packs);
3806 /* Expand any parameter packs that occur in the template arguments in
3809 expand_template_argument_pack (tree args)
3811 tree result_args = NULL_TREE;
3812 int in_arg, out_arg = 0, nargs = args ? TREE_VEC_LENGTH (args) : 0;
3813 int num_result_args = -1;
3814 int non_default_args_count = -1;
3816 /* First, determine if we need to expand anything, and the number of
3817 slots we'll need. */
3818 for (in_arg = 0; in_arg < nargs; ++in_arg)
3820 tree arg = TREE_VEC_ELT (args, in_arg);
3821 if (arg == NULL_TREE)
3823 if (ARGUMENT_PACK_P (arg))
3825 int num_packed = TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg));
3826 if (num_result_args < 0)
3827 num_result_args = in_arg + num_packed;
3829 num_result_args += num_packed;
3833 if (num_result_args >= 0)
3838 /* If no expansion is necessary, we're done. */
3839 if (num_result_args < 0)
3842 /* Expand arguments. */
3843 result_args = make_tree_vec (num_result_args);
3844 if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (args))
3845 non_default_args_count =
3846 GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (args);
3847 for (in_arg = 0; in_arg < nargs; ++in_arg)
3849 tree arg = TREE_VEC_ELT (args, in_arg);
3850 if (ARGUMENT_PACK_P (arg))
3852 tree packed = ARGUMENT_PACK_ARGS (arg);
3853 int i, num_packed = TREE_VEC_LENGTH (packed);
3854 for (i = 0; i < num_packed; ++i, ++out_arg)
3855 TREE_VEC_ELT (result_args, out_arg) = TREE_VEC_ELT(packed, i);
3856 if (non_default_args_count > 0)
3857 non_default_args_count += num_packed - 1;
3861 TREE_VEC_ELT (result_args, out_arg) = arg;
3865 if (non_default_args_count >= 0)
3866 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (result_args, non_default_args_count);
3870 /* Checks if DECL shadows a template parameter.
3872 [temp.local]: A template-parameter shall not be redeclared within its
3873 scope (including nested scopes).
3875 Emits an error and returns TRUE if the DECL shadows a parameter,
3876 returns FALSE otherwise. */
3879 check_template_shadow (tree decl)
3883 /* If we're not in a template, we can't possibly shadow a template
3885 if (!current_template_parms)
3888 /* Figure out what we're shadowing. */
3889 if (TREE_CODE (decl) == OVERLOAD)
3890 decl = OVL_CURRENT (decl);
3891 olddecl = innermost_non_namespace_value (DECL_NAME (decl));
3893 /* If there's no previous binding for this name, we're not shadowing
3894 anything, let alone a template parameter. */
3898 /* If we're not shadowing a template parameter, we're done. Note
3899 that OLDDECL might be an OVERLOAD (or perhaps even an
3900 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3902 if (!DECL_P (olddecl) || !DECL_TEMPLATE_PARM_P (olddecl))
3905 /* We check for decl != olddecl to avoid bogus errors for using a
3906 name inside a class. We check TPFI to avoid duplicate errors for
3907 inline member templates. */
3909 || (DECL_TEMPLATE_PARM_P (decl)
3910 && TEMPLATE_PARMS_FOR_INLINE (current_template_parms)))
3913 /* Don't complain about the injected class name, as we've already
3914 complained about the class itself. */
3915 if (DECL_SELF_REFERENCE_P (decl))
3918 if (DECL_TEMPLATE_PARM_P (decl))
3919 error ("declaration of template parameter %q+D shadows "
3920 "template parameter", decl);
3922 error ("declaration of %q+#D shadows template parameter", decl);
3923 inform (DECL_SOURCE_LOCATION (olddecl),
3924 "template parameter %qD declared here", olddecl);
3928 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3929 ORIG_LEVEL, DECL, and TYPE. */
3932 build_template_parm_index (int index,
3938 tree t = make_node (TEMPLATE_PARM_INDEX);
3939 TEMPLATE_PARM_IDX (t) = index;
3940 TEMPLATE_PARM_LEVEL (t) = level;
3941 TEMPLATE_PARM_ORIG_LEVEL (t) = orig_level;
3942 TEMPLATE_PARM_DECL (t) = decl;
3943 TREE_TYPE (t) = type;
3944 TREE_CONSTANT (t) = TREE_CONSTANT (decl);
3945 TREE_READONLY (t) = TREE_READONLY (decl);
3950 /* Find the canonical type parameter for the given template type
3951 parameter. Returns the canonical type parameter, which may be TYPE
3952 if no such parameter existed. */
3955 canonical_type_parameter (tree type)
3958 int idx = TEMPLATE_TYPE_IDX (type);
3959 if (!canonical_template_parms)
3960 vec_alloc (canonical_template_parms, idx+1);
3962 while (canonical_template_parms->length () <= (unsigned)idx)
3963 vec_safe_push (canonical_template_parms, NULL_TREE);
3965 list = (*canonical_template_parms)[idx];
3966 while (list && !comptypes (type, TREE_VALUE (list), COMPARE_STRUCTURAL))
3967 list = TREE_CHAIN (list);
3970 return TREE_VALUE (list);
3973 (*canonical_template_parms)[idx]
3974 = tree_cons (NULL_TREE, type,
3975 (*canonical_template_parms)[idx]);
3980 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3981 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3982 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3983 new one is created. */
3986 reduce_template_parm_level (tree index, tree type, int levels, tree args,
3987 tsubst_flags_t complain)
3989 if (TEMPLATE_PARM_DESCENDANTS (index) == NULL_TREE
3990 || (TEMPLATE_PARM_LEVEL (TEMPLATE_PARM_DESCENDANTS (index))
3991 != TEMPLATE_PARM_LEVEL (index) - levels)
3992 || !same_type_p (type, TREE_TYPE (TEMPLATE_PARM_DESCENDANTS (index))))
3994 tree orig_decl = TEMPLATE_PARM_DECL (index);
3997 decl = build_decl (DECL_SOURCE_LOCATION (orig_decl),
3998 TREE_CODE (orig_decl), DECL_NAME (orig_decl), type);
3999 TREE_CONSTANT (decl) = TREE_CONSTANT (orig_decl);
4000 TREE_READONLY (decl) = TREE_READONLY (orig_decl);
4001 DECL_ARTIFICIAL (decl) = 1;
4002 SET_DECL_TEMPLATE_PARM_P (decl);
4004 t = build_template_parm_index (TEMPLATE_PARM_IDX (index),
4005 TEMPLATE_PARM_LEVEL (index) - levels,
4006 TEMPLATE_PARM_ORIG_LEVEL (index),
4008 TEMPLATE_PARM_DESCENDANTS (index) = t;
4009 TEMPLATE_PARM_PARAMETER_PACK (t)
4010 = TEMPLATE_PARM_PARAMETER_PACK (index);
4012 /* Template template parameters need this. */
4013 if (TREE_CODE (decl) == TEMPLATE_DECL)
4015 DECL_TEMPLATE_RESULT (decl)
4016 = build_decl (DECL_SOURCE_LOCATION (decl),
4017 TYPE_DECL, DECL_NAME (decl), type);
4018 DECL_ARTIFICIAL (DECL_TEMPLATE_RESULT (decl)) = true;
4019 DECL_TEMPLATE_PARMS (decl) = tsubst_template_parms
4020 (DECL_TEMPLATE_PARMS (orig_decl), args, complain);
4024 return TEMPLATE_PARM_DESCENDANTS (index);
4027 /* Process information from new template parameter PARM and append it
4028 to the LIST being built. This new parameter is a non-type
4029 parameter iff IS_NON_TYPE is true. This new parameter is a
4030 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
4034 process_template_parm (tree list, location_t parm_loc, tree parm,
4035 bool is_non_type, bool is_parameter_pack)
4040 gcc_assert (TREE_CODE (parm) == TREE_LIST);
4041 tree defval = TREE_PURPOSE (parm);
4042 tree constr = TREE_TYPE (parm);
4046 tree p = tree_last (list);
4048 if (p && TREE_VALUE (p) != error_mark_node)
4051 if (TREE_CODE (p) == TYPE_DECL || TREE_CODE (p) == TEMPLATE_DECL)
4052 idx = TEMPLATE_TYPE_IDX (TREE_TYPE (p));
4054 idx = TEMPLATE_PARM_IDX (DECL_INITIAL (p));
4062 parm = TREE_VALUE (parm);
4064 SET_DECL_TEMPLATE_PARM_P (parm);
4066 if (TREE_TYPE (parm) != error_mark_node)
4070 The top-level cv-qualifiers on the template-parameter are
4071 ignored when determining its type. */
4072 TREE_TYPE (parm) = TYPE_MAIN_VARIANT (TREE_TYPE (parm));
4073 if (invalid_nontype_parm_type_p (TREE_TYPE (parm), 1))
4074 TREE_TYPE (parm) = error_mark_node;
4075 else if (uses_parameter_packs (TREE_TYPE (parm))
4076 && !is_parameter_pack
4077 /* If we're in a nested template parameter list, the template
4078 template parameter could be a parameter pack. */
4079 && processing_template_parmlist == 1)
4081 /* This template parameter is not a parameter pack, but it
4082 should be. Complain about "bare" parameter packs. */
4083 check_for_bare_parameter_packs (TREE_TYPE (parm));
4085 /* Recover by calling this a parameter pack. */
4086 is_parameter_pack = true;
4090 /* A template parameter is not modifiable. */
4091 TREE_CONSTANT (parm) = 1;
4092 TREE_READONLY (parm) = 1;
4093 decl = build_decl (parm_loc,
4094 CONST_DECL, DECL_NAME (parm), TREE_TYPE (parm));
4095 TREE_CONSTANT (decl) = 1;
4096 TREE_READONLY (decl) = 1;
4097 DECL_INITIAL (parm) = DECL_INITIAL (decl)
4098 = build_template_parm_index (idx, processing_template_decl,
4099 processing_template_decl,
4100 decl, TREE_TYPE (parm));
4102 TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))
4103 = is_parameter_pack;
4108 parm = TREE_VALUE (TREE_VALUE (parm));
4110 if (parm && TREE_CODE (parm) == TEMPLATE_DECL)
4112 t = cxx_make_type (TEMPLATE_TEMPLATE_PARM);
4113 /* This is for distinguishing between real templates and template
4114 template parameters */
4115 TREE_TYPE (parm) = t;
4116 TREE_TYPE (DECL_TEMPLATE_RESULT (parm)) = t;
4121 t = cxx_make_type (TEMPLATE_TYPE_PARM);
4122 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
4123 decl = build_decl (parm_loc,
4124 TYPE_DECL, parm, t);
4127 TYPE_NAME (t) = decl;
4128 TYPE_STUB_DECL (t) = decl;
4130 TEMPLATE_TYPE_PARM_INDEX (t)
4131 = build_template_parm_index (idx, processing_template_decl,
4132 processing_template_decl,
4133 decl, TREE_TYPE (parm));
4134 TEMPLATE_TYPE_PARAMETER_PACK (t) = is_parameter_pack;
4135 TYPE_CANONICAL (t) = canonical_type_parameter (t);
4137 DECL_ARTIFICIAL (decl) = 1;
4138 SET_DECL_TEMPLATE_PARM_P (decl);
4140 /* Build requirements for the type/template parameter.
4141 This must be done after SET_DECL_TEMPLATE_PARM_P or
4142 process_template_parm could fail. */
4143 tree reqs = finish_shorthand_constraint (parm, constr);
4147 /* Build the parameter node linking the parameter declaration,
4148 its default argument (if any), and its constraints (if any). */
4149 parm = build_tree_list (defval, parm);
4150 TEMPLATE_PARM_CONSTRAINTS (parm) = reqs;
4152 return chainon (list, parm);
4155 /* The end of a template parameter list has been reached. Process the
4156 tree list into a parameter vector, converting each parameter into a more
4157 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
4161 end_template_parm_list (tree parms)
4165 tree saved_parmlist = make_tree_vec (list_length (parms));
4167 /* Pop the dummy parameter level and add the real one. */
4168 current_template_parms = TREE_CHAIN (current_template_parms);
4170 current_template_parms
4171 = tree_cons (size_int (processing_template_decl),
4172 saved_parmlist, current_template_parms);
4174 for (parm = parms, nparms = 0; parm; parm = next, nparms++)
4176 next = TREE_CHAIN (parm);
4177 TREE_VEC_ELT (saved_parmlist, nparms) = parm;
4178 TREE_CHAIN (parm) = NULL_TREE;
4181 --processing_template_parmlist;
4183 return saved_parmlist;
4186 // Explicitly indicate the end of the template parameter list. We assume
4187 // that the current template parameters have been constructed and/or
4188 // managed explicitly, as when creating new template template parameters
4189 // from a shorthand constraint.
4191 end_template_parm_list ()
4193 --processing_template_parmlist;
4196 /* end_template_decl is called after a template declaration is seen. */
4199 end_template_decl (void)
4201 reset_specialization ();
4203 if (! processing_template_decl)
4206 /* This matches the pushlevel in begin_template_parm_list. */
4209 --processing_template_decl;
4210 current_template_parms = TREE_CHAIN (current_template_parms);
4213 /* Takes a TREE_LIST representing a template parameter and convert it
4214 into an argument suitable to be passed to the type substitution
4215 functions. Note that If the TREE_LIST contains an error_mark
4216 node, the returned argument is error_mark_node. */
4219 template_parm_to_arg (tree t)
4223 || TREE_CODE (t) != TREE_LIST)
4226 if (error_operand_p (TREE_VALUE (t)))
4227 return error_mark_node;
4231 if (TREE_CODE (t) == TYPE_DECL
4232 || TREE_CODE (t) == TEMPLATE_DECL)
4236 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
4238 /* Turn this argument into a TYPE_ARGUMENT_PACK
4239 with a single element, which expands T. */
4240 tree vec = make_tree_vec (1);
4242 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (vec, TREE_VEC_LENGTH (vec));
4244 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
4246 t = cxx_make_type (TYPE_ARGUMENT_PACK);
4247 SET_ARGUMENT_PACK_ARGS (t, vec);
4252 t = DECL_INITIAL (t);
4254 if (TEMPLATE_PARM_PARAMETER_PACK (t))
4256 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
4257 with a single element, which expands T. */
4258 tree vec = make_tree_vec (1);
4259 tree type = TREE_TYPE (TEMPLATE_PARM_DECL (t));
4261 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (vec, TREE_VEC_LENGTH (vec));
4263 t = convert_from_reference (t);
4264 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
4266 t = make_node (NONTYPE_ARGUMENT_PACK);
4267 SET_ARGUMENT_PACK_ARGS (t, vec);
4268 TREE_TYPE (t) = type;
4271 t = convert_from_reference (t);
4276 /* Given a set of template parameters, return them as a set of template
4277 arguments. The template parameters are represented as a TREE_VEC, in
4278 the form documented in cp-tree.h for template arguments. */
4281 template_parms_to_args (tree parms)
4284 tree args = NULL_TREE;
4285 int length = TMPL_PARMS_DEPTH (parms);
4288 /* If there is only one level of template parameters, we do not
4289 create a TREE_VEC of TREE_VECs. Instead, we return a single
4290 TREE_VEC containing the arguments. */
4292 args = make_tree_vec (length);
4294 for (header = parms; header; header = TREE_CHAIN (header))
4296 tree a = copy_node (TREE_VALUE (header));
4299 TREE_TYPE (a) = NULL_TREE;
4300 for (i = TREE_VEC_LENGTH (a) - 1; i >= 0; --i)
4301 TREE_VEC_ELT (a, i) = template_parm_to_arg (TREE_VEC_ELT (a, i));
4304 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (a, TREE_VEC_LENGTH (a));
4307 TREE_VEC_ELT (args, --l) = a;
4315 /* Within the declaration of a template, return the currently active
4316 template parameters as an argument TREE_VEC. */
4319 current_template_args (void)
4321 return template_parms_to_args (current_template_parms);
4324 /* Update the declared TYPE by doing any lookups which were thought to be
4325 dependent, but are not now that we know the SCOPE of the declarator. */
4328 maybe_update_decl_type (tree orig_type, tree scope)
4330 tree type = orig_type;
4332 if (type == NULL_TREE)
4335 if (TREE_CODE (orig_type) == TYPE_DECL)
4336 type = TREE_TYPE (type);
4338 if (scope && TYPE_P (scope) && dependent_type_p (scope)
4339 && dependent_type_p (type)
4340 /* Don't bother building up the args in this case. */
4341 && TREE_CODE (type) != TEMPLATE_TYPE_PARM)
4343 /* tsubst in the args corresponding to the template parameters,
4344 including auto if present. Most things will be unchanged, but
4345 make_typename_type and tsubst_qualified_id will resolve
4346 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4347 tree args = current_template_args ();
4348 tree auto_node = type_uses_auto (type);
4352 tree auto_vec = make_tree_vec (1);
4353 TREE_VEC_ELT (auto_vec, 0) = auto_node;
4354 args = add_to_template_args (args, auto_vec);
4356 pushed = push_scope (scope);
4357 type = tsubst (type, args, tf_warning_or_error, NULL_TREE);
4362 if (type == error_mark_node)
4365 if (TREE_CODE (orig_type) == TYPE_DECL)
4367 if (same_type_p (type, TREE_TYPE (orig_type)))
4370 type = TYPE_NAME (type);
4375 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4376 template PARMS and constraints, CONSTR. If MEMBER_TEMPLATE_P is true,
4377 the new template is a member template. */
4380 build_template_decl (tree decl, tree parms, bool member_template_p)
4382 tree tmpl = build_lang_decl (TEMPLATE_DECL, DECL_NAME (decl), NULL_TREE);
4383 DECL_TEMPLATE_PARMS (tmpl) = parms;
4384 DECL_CONTEXT (tmpl) = DECL_CONTEXT (decl);
4385 DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl);
4386 DECL_MEMBER_TEMPLATE_P (tmpl) = member_template_p;
4391 struct template_parm_data
4393 /* The level of the template parameters we are currently
4397 /* The index of the specialization argument we are currently
4401 /* An array whose size is the number of template parameters. The
4402 elements are nonzero if the parameter has been used in any one
4403 of the arguments processed so far. */
4406 /* An array whose size is the number of template arguments. The
4407 elements are nonzero if the argument makes use of template
4408 parameters of this level. */
4409 int* arg_uses_template_parms;
4412 /* Subroutine of push_template_decl used to see if each template
4413 parameter in a partial specialization is used in the explicit
4414 argument list. If T is of the LEVEL given in DATA (which is
4415 treated as a template_parm_data*), then DATA->PARMS is marked
4419 mark_template_parm (tree t, void* data)
4423 struct template_parm_data* tpd = (struct template_parm_data*) data;
4425 template_parm_level_and_index (t, &level, &idx);
4427 if (level == tpd->level)
4429 tpd->parms[idx] = 1;
4430 tpd->arg_uses_template_parms[tpd->current_arg] = 1;
4433 /* Return zero so that for_each_template_parm will continue the
4434 traversal of the tree; we want to mark *every* template parm. */
4438 /* Process the partial specialization DECL. */
4441 process_partial_specialization (tree decl)
4443 tree type = TREE_TYPE (decl);
4444 tree tinfo = get_template_info (decl);
4445 tree maintmpl = TI_TEMPLATE (tinfo);
4446 tree specargs = TI_ARGS (tinfo);
4447 tree inner_args = INNERMOST_TEMPLATE_ARGS (specargs);
4448 tree main_inner_parms = DECL_INNERMOST_TEMPLATE_PARMS (maintmpl);
4451 int nargs = TREE_VEC_LENGTH (inner_args);
4454 bool did_error_intro = false;
4455 struct template_parm_data tpd;
4456 struct template_parm_data tpd2;
4458 gcc_assert (current_template_parms);
4460 /* A concept cannot be specialized. */
4461 if (flag_concepts && variable_concept_p (maintmpl))
4463 error ("specialization of variable concept %q#D", maintmpl);
4464 return error_mark_node;
4467 inner_parms = INNERMOST_TEMPLATE_PARMS (current_template_parms);
4468 ntparms = TREE_VEC_LENGTH (inner_parms);
4470 /* We check that each of the template parameters given in the
4471 partial specialization is used in the argument list to the
4472 specialization. For example:
4474 template <class T> struct S;
4475 template <class T> struct S<T*>;
4477 The second declaration is OK because `T*' uses the template
4478 parameter T, whereas
4480 template <class T> struct S<int>;
4482 is no good. Even trickier is:
4493 The S2<T> declaration is actually invalid; it is a
4494 full-specialization. Of course,
4497 struct S2<T (*)(U)>;
4499 or some such would have been OK. */
4500 tpd.level = TMPL_PARMS_DEPTH (current_template_parms);
4501 tpd.parms = XALLOCAVEC (int, ntparms);
4502 memset (tpd.parms, 0, sizeof (int) * ntparms);
4504 tpd.arg_uses_template_parms = XALLOCAVEC (int, nargs);
4505 memset (tpd.arg_uses_template_parms, 0, sizeof (int) * nargs);
4506 for (i = 0; i < nargs; ++i)
4508 tpd.current_arg = i;
4509 for_each_template_parm (TREE_VEC_ELT (inner_args, i),
4510 &mark_template_parm,
4513 /*include_nondeduced_p=*/false);
4515 for (i = 0; i < ntparms; ++i)
4516 if (tpd.parms[i] == 0)
4518 /* One of the template parms was not used in a deduced context in the
4520 if (!did_error_intro)
4522 error ("template parameters not deducible in "
4523 "partial specialization:");
4524 did_error_intro = true;
4527 inform (input_location, " %qD",
4528 TREE_VALUE (TREE_VEC_ELT (inner_parms, i)));
4531 if (did_error_intro)
4532 return error_mark_node;
4534 /* [temp.class.spec]
4536 The argument list of the specialization shall not be identical to
4537 the implicit argument list of the primary template. */
4539 = TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (maintmpl)));
4540 if (comp_template_args (inner_args, INNERMOST_TEMPLATE_ARGS (main_args))
4542 || !strictly_subsumes (current_template_constraints (),
4543 get_constraints (maintmpl))))
4546 error ("partial specialization %q+D does not specialize "
4547 "any template arguments", decl);
4549 error ("partial specialization %q+D does not specialize any "
4550 "template arguments and is not more constrained than", decl);
4551 inform (DECL_SOURCE_LOCATION (maintmpl), "primary template here");
4554 /* A partial specialization that replaces multiple parameters of the
4555 primary template with a pack expansion is less specialized for those
4557 if (nargs < DECL_NTPARMS (maintmpl))
4559 error ("partial specialization is not more specialized than the "
4560 "primary template because it replaces multiple parameters "
4561 "with a pack expansion");
4562 inform (DECL_SOURCE_LOCATION (maintmpl), "primary template here");
4566 /* [temp.class.spec]
4568 A partially specialized non-type argument expression shall not
4569 involve template parameters of the partial specialization except
4570 when the argument expression is a simple identifier.
4572 The type of a template parameter corresponding to a specialized
4573 non-type argument shall not be dependent on a parameter of the
4576 Also, we verify that pack expansions only occur at the
4577 end of the argument list. */
4578 gcc_assert (nargs == DECL_NTPARMS (maintmpl));
4580 for (i = 0; i < nargs; ++i)
4582 tree parm = TREE_VALUE (TREE_VEC_ELT (main_inner_parms, i));
4583 tree arg = TREE_VEC_ELT (inner_args, i);
4584 tree packed_args = NULL_TREE;
4587 if (ARGUMENT_PACK_P (arg))
4589 /* Extract the arguments from the argument pack. We'll be
4590 iterating over these in the following loop. */
4591 packed_args = ARGUMENT_PACK_ARGS (arg);
4592 len = TREE_VEC_LENGTH (packed_args);
4595 for (j = 0; j < len; j++)
4598 /* Get the Jth argument in the parameter pack. */
4599 arg = TREE_VEC_ELT (packed_args, j);
4601 if (PACK_EXPANSION_P (arg))
4603 /* Pack expansions must come at the end of the
4605 if ((packed_args && j < len - 1)
4606 || (!packed_args && i < nargs - 1))
4608 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
4609 error ("parameter pack argument %qE must be at the "
4610 "end of the template argument list", arg);
4612 error ("parameter pack argument %qT must be at the "
4613 "end of the template argument list", arg);
4617 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
4618 /* We only care about the pattern. */
4619 arg = PACK_EXPANSION_PATTERN (arg);
4621 if (/* These first two lines are the `non-type' bit. */
4623 && TREE_CODE (arg) != TEMPLATE_DECL
4624 /* This next two lines are the `argument expression is not just a
4625 simple identifier' condition and also the `specialized
4626 non-type argument' bit. */
4627 && TREE_CODE (arg) != TEMPLATE_PARM_INDEX
4628 && !(REFERENCE_REF_P (arg)
4629 && TREE_CODE (TREE_OPERAND (arg, 0)) == TEMPLATE_PARM_INDEX))
4631 if ((!packed_args && tpd.arg_uses_template_parms[i])
4632 || (packed_args && uses_template_parms (arg)))
4633 error ("template argument %qE involves template parameter(s)",
4637 /* Look at the corresponding template parameter,
4638 marking which template parameters its type depends
4640 tree type = TREE_TYPE (parm);
4644 /* We haven't yet initialized TPD2. Do so now. */
4645 tpd2.arg_uses_template_parms = XALLOCAVEC (int, nargs);
4646 /* The number of parameters here is the number in the
4647 main template, which, as checked in the assertion
4649 tpd2.parms = XALLOCAVEC (int, nargs);
4651 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (maintmpl));
4654 /* Mark the template parameters. But this time, we're
4655 looking for the template parameters of the main
4656 template, not in the specialization. */
4657 tpd2.current_arg = i;
4658 tpd2.arg_uses_template_parms[i] = 0;
4659 memset (tpd2.parms, 0, sizeof (int) * nargs);
4660 for_each_template_parm (type,
4661 &mark_template_parm,
4664 /*include_nondeduced_p=*/false);
4666 if (tpd2.arg_uses_template_parms [i])
4668 /* The type depended on some template parameters.
4669 If they are fully specialized in the
4670 specialization, that's OK. */
4673 for (j = 0; j < nargs; ++j)
4674 if (tpd2.parms[j] != 0
4675 && tpd.arg_uses_template_parms [j])
4678 error_n (input_location, count,
4679 "type %qT of template argument %qE depends "
4680 "on a template parameter",
4681 "type %qT of template argument %qE depends "
4682 "on template parameters",
4691 /* We should only get here once. */
4692 if (TREE_CODE (decl) == TYPE_DECL)
4693 gcc_assert (!COMPLETE_TYPE_P (type));
4695 // Build the template decl.
4696 tree tmpl = build_template_decl (decl, current_template_parms,
4697 DECL_MEMBER_TEMPLATE_P (maintmpl));
4698 TREE_TYPE (tmpl) = type;
4699 DECL_TEMPLATE_RESULT (tmpl) = decl;
4700 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
4701 DECL_TEMPLATE_INFO (tmpl) = build_template_info (maintmpl, specargs);
4702 DECL_PRIMARY_TEMPLATE (tmpl) = maintmpl;
4705 /* We didn't register this in check_explicit_specialization so we could
4706 wait until the constraints were set. */
4707 decl = register_specialization (decl, maintmpl, specargs, false, 0);
4709 associate_classtype_constraints (type);
4711 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)
4712 = tree_cons (specargs, tmpl,
4713 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl));
4714 TREE_TYPE (DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)) = type;
4716 for (inst = DECL_TEMPLATE_INSTANTIATIONS (maintmpl); inst;
4717 inst = TREE_CHAIN (inst))
4719 tree instance = TREE_VALUE (inst);
4720 if (TYPE_P (instance)
4721 ? (COMPLETE_TYPE_P (instance)
4722 && CLASSTYPE_IMPLICIT_INSTANTIATION (instance))
4723 : DECL_TEMPLATE_INSTANTIATION (instance))
4725 tree spec = most_specialized_partial_spec (instance, tf_none);
4726 tree inst_decl = (DECL_P (instance)
4727 ? instance : TYPE_NAME (instance));
4730 else if (spec == error_mark_node)
4731 permerror (input_location,
4732 "declaration of %qD ambiguates earlier template "
4733 "instantiation for %qD", decl, inst_decl);
4734 else if (TREE_VALUE (spec) == tmpl)
4735 permerror (input_location,
4736 "partial specialization of %qD after instantiation "
4737 "of %qD", decl, inst_decl);
4744 /* PARM is a template parameter of some form; return the corresponding
4745 TEMPLATE_PARM_INDEX. */
4748 get_template_parm_index (tree parm)
4750 if (TREE_CODE (parm) == PARM_DECL
4751 || TREE_CODE (parm) == CONST_DECL)
4752 parm = DECL_INITIAL (parm);
4753 else if (TREE_CODE (parm) == TYPE_DECL
4754 || TREE_CODE (parm) == TEMPLATE_DECL)
4755 parm = TREE_TYPE (parm);
4756 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
4757 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM
4758 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM)
4759 parm = TEMPLATE_TYPE_PARM_INDEX (parm);
4760 gcc_assert (TREE_CODE (parm) == TEMPLATE_PARM_INDEX);
4764 /* Subroutine of fixed_parameter_pack_p below. Look for any template
4765 parameter packs used by the template parameter PARM. */
4768 fixed_parameter_pack_p_1 (tree parm, struct find_parameter_pack_data *ppd)
4770 /* A type parm can't refer to another parm. */
4771 if (TREE_CODE (parm) == TYPE_DECL)
4773 else if (TREE_CODE (parm) == PARM_DECL)
4775 cp_walk_tree (&TREE_TYPE (parm), &find_parameter_packs_r,
4780 gcc_assert (TREE_CODE (parm) == TEMPLATE_DECL);
4782 tree vec = INNERMOST_TEMPLATE_PARMS (DECL_TEMPLATE_PARMS (parm));
4783 for (int i = 0; i < TREE_VEC_LENGTH (vec); ++i)
4784 fixed_parameter_pack_p_1 (TREE_VALUE (TREE_VEC_ELT (vec, i)), ppd);
4787 /* PARM is a template parameter pack. Return any parameter packs used in
4788 its type or the type of any of its template parameters. If there are
4789 any such packs, it will be instantiated into a fixed template parameter
4790 list by partial instantiation rather than be fully deduced. */
4793 fixed_parameter_pack_p (tree parm)
4795 /* This can only be true in a member template. */
4796 if (TEMPLATE_PARM_ORIG_LEVEL (get_template_parm_index (parm)) < 2)
4798 /* This can only be true for a parameter pack. */
4799 if (!template_parameter_pack_p (parm))
4801 /* A type parm can't refer to another parm. */
4802 if (TREE_CODE (parm) == TYPE_DECL)
4805 tree parameter_packs = NULL_TREE;
4806 struct find_parameter_pack_data ppd;
4807 ppd.parameter_packs = ¶meter_packs;
4808 ppd.visited = new hash_set<tree>;
4809 ppd.type_pack_expansion_p = false;
4811 fixed_parameter_pack_p_1 (parm, &ppd);
4814 return parameter_packs;
4817 /* Check that a template declaration's use of default arguments and
4818 parameter packs is not invalid. Here, PARMS are the template
4819 parameters. IS_PRIMARY is true if DECL is the thing declared by
4820 a primary template. IS_PARTIAL is true if DECL is a partial
4823 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4824 declaration (but not a definition); 1 indicates a declaration, 2
4825 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4826 emitted for extraneous default arguments.
4828 Returns TRUE if there were no errors found, FALSE otherwise. */
4831 check_default_tmpl_args (tree decl, tree parms, bool is_primary,
4832 bool is_partial, int is_friend_decl)
4835 int last_level_to_check;
4837 bool no_errors = true;
4841 A default template-argument shall not be specified in a
4842 function template declaration or a function template definition, nor
4843 in the template-parameter-list of the definition of a member of a
4846 if (TREE_CODE (CP_DECL_CONTEXT (decl)) == FUNCTION_DECL
4847 || (TREE_CODE (decl) == FUNCTION_DECL && DECL_LOCAL_FUNCTION_P (decl)))
4848 /* You can't have a function template declaration in a local
4849 scope, nor you can you define a member of a class template in a
4853 if ((TREE_CODE (decl) == TYPE_DECL
4855 && LAMBDA_TYPE_P (TREE_TYPE (decl)))
4856 || (TREE_CODE (decl) == FUNCTION_DECL
4857 && LAMBDA_FUNCTION_P (decl)))
4858 /* A lambda doesn't have an explicit declaration; don't complain
4859 about the parms of the enclosing class. */
4862 if (current_class_type
4863 && !TYPE_BEING_DEFINED (current_class_type)
4864 && DECL_LANG_SPECIFIC (decl)
4865 && DECL_DECLARES_FUNCTION_P (decl)
4866 /* If this is either a friend defined in the scope of the class
4867 or a member function. */
4868 && (DECL_FUNCTION_MEMBER_P (decl)
4869 ? same_type_p (DECL_CONTEXT (decl), current_class_type)
4870 : DECL_FRIEND_CONTEXT (decl)
4871 ? same_type_p (DECL_FRIEND_CONTEXT (decl), current_class_type)
4873 /* And, if it was a member function, it really was defined in
4874 the scope of the class. */
4875 && (!DECL_FUNCTION_MEMBER_P (decl)
4876 || DECL_INITIALIZED_IN_CLASS_P (decl)))
4877 /* We already checked these parameters when the template was
4878 declared, so there's no need to do it again now. This function
4879 was defined in class scope, but we're processing its body now
4880 that the class is complete. */
4883 /* Core issue 226 (C++0x only): the following only applies to class
4886 && ((cxx_dialect == cxx98) || TREE_CODE (decl) != FUNCTION_DECL))
4890 If a template-parameter has a default template-argument, all
4891 subsequent template-parameters shall have a default
4892 template-argument supplied. */
4893 for (parm_level = parms; parm_level; parm_level = TREE_CHAIN (parm_level))
4895 tree inner_parms = TREE_VALUE (parm_level);
4896 int ntparms = TREE_VEC_LENGTH (inner_parms);
4897 int seen_def_arg_p = 0;
4900 for (i = 0; i < ntparms; ++i)
4902 tree parm = TREE_VEC_ELT (inner_parms, i);
4904 if (parm == error_mark_node)
4907 if (TREE_PURPOSE (parm))
4909 else if (seen_def_arg_p
4910 && !template_parameter_pack_p (TREE_VALUE (parm)))
4912 error ("no default argument for %qD", TREE_VALUE (parm));
4913 /* For better subsequent error-recovery, we indicate that
4914 there should have been a default argument. */
4915 TREE_PURPOSE (parm) = error_mark_node;
4918 else if (!is_partial
4920 /* Don't complain about an enclosing partial
4922 && parm_level == parms
4923 && TREE_CODE (decl) == TYPE_DECL
4925 && template_parameter_pack_p (TREE_VALUE (parm))
4926 /* A fixed parameter pack will be partially
4927 instantiated into a fixed length list. */
4928 && !fixed_parameter_pack_p (TREE_VALUE (parm)))
4930 /* A primary class template can only have one
4931 parameter pack, at the end of the template
4934 error ("parameter pack %q+D must be at the end of the"
4935 " template parameter list", TREE_VALUE (parm));
4937 TREE_VALUE (TREE_VEC_ELT (inner_parms, i))
4945 if (((cxx_dialect == cxx98) && TREE_CODE (decl) != TYPE_DECL)
4949 /* For an ordinary class template, default template arguments are
4950 allowed at the innermost level, e.g.:
4951 template <class T = int>
4953 but, in a partial specialization, they're not allowed even
4954 there, as we have in [temp.class.spec]:
4956 The template parameter list of a specialization shall not
4957 contain default template argument values.
4959 So, for a partial specialization, or for a function template
4960 (in C++98/C++03), we look at all of them. */
4963 /* But, for a primary class template that is not a partial
4964 specialization we look at all template parameters except the
4966 parms = TREE_CHAIN (parms);
4968 /* Figure out what error message to issue. */
4969 if (is_friend_decl == 2)
4970 msg = G_("default template arguments may not be used in function template "
4971 "friend re-declaration");
4972 else if (is_friend_decl)
4973 msg = G_("default template arguments may not be used in function template "
4974 "friend declarations");
4975 else if (TREE_CODE (decl) == FUNCTION_DECL && (cxx_dialect == cxx98))
4976 msg = G_("default template arguments may not be used in function templates "
4977 "without -std=c++11 or -std=gnu++11");
4978 else if (is_partial)
4979 msg = G_("default template arguments may not be used in "
4980 "partial specializations");
4981 else if (current_class_type && CLASSTYPE_IS_TEMPLATE (current_class_type))
4982 msg = G_("default argument for template parameter for class enclosing %qD");
4984 /* Per [temp.param]/9, "A default template-argument shall not be
4985 specified in the template-parameter-lists of the definition of
4986 a member of a class template that appears outside of the member's
4987 class.", thus if we aren't handling a member of a class template
4988 there is no need to examine the parameters. */
4991 if (current_class_type && TYPE_BEING_DEFINED (current_class_type))
4992 /* If we're inside a class definition, there's no need to
4993 examine the parameters to the class itself. On the one
4994 hand, they will be checked when the class is defined, and,
4995 on the other, default arguments are valid in things like:
4996 template <class T = double>
4997 struct S { template <class U> void f(U); };
4998 Here the default argument for `S' has no bearing on the
4999 declaration of `f'. */
5000 last_level_to_check = template_class_depth (current_class_type) + 1;
5002 /* Check everything. */
5003 last_level_to_check = 0;
5005 for (parm_level = parms;
5006 parm_level && TMPL_PARMS_DEPTH (parm_level) >= last_level_to_check;
5007 parm_level = TREE_CHAIN (parm_level))
5009 tree inner_parms = TREE_VALUE (parm_level);
5013 ntparms = TREE_VEC_LENGTH (inner_parms);
5014 for (i = 0; i < ntparms; ++i)
5016 if (TREE_VEC_ELT (inner_parms, i) == error_mark_node)
5019 if (TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)))
5024 if (is_friend_decl == 2)
5031 /* Clear out the default argument so that we are not
5033 TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)) = NULL_TREE;
5037 /* At this point, if we're still interested in issuing messages,
5038 they must apply to classes surrounding the object declared. */
5040 msg = G_("default argument for template parameter for class "
5047 /* Worker for push_template_decl_real, called via
5048 for_each_template_parm. DATA is really an int, indicating the
5049 level of the parameters we are interested in. If T is a template
5050 parameter of that level, return nonzero. */
5053 template_parm_this_level_p (tree t, void* data)
5055 int this_level = *(int *)data;
5058 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
5059 level = TEMPLATE_PARM_LEVEL (t);
5061 level = TEMPLATE_TYPE_LEVEL (t);
5062 return level == this_level;
5065 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
5066 parameters given by current_template_args, or reuses a
5067 previously existing one, if appropriate. Returns the DECL, or an
5068 equivalent one, if it is replaced via a call to duplicate_decls.
5070 If IS_FRIEND is true, DECL is a friend declaration. */
5073 push_template_decl_real (tree decl, bool is_friend)
5081 int new_template_p = 0;
5082 /* True if the template is a member template, in the sense of
5084 bool member_template_p = false;
5086 if (decl == error_mark_node || !current_template_parms)
5087 return error_mark_node;
5089 /* See if this is a partial specialization. */
5090 is_partial = ((DECL_IMPLICIT_TYPEDEF_P (decl)
5091 && TREE_CODE (TREE_TYPE (decl)) != ENUMERAL_TYPE
5092 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)))
5094 && DECL_LANG_SPECIFIC (decl)
5095 && DECL_TEMPLATE_SPECIALIZATION (decl)
5096 && TINFO_USED_TEMPLATE_ID (DECL_TEMPLATE_INFO (decl))));
5098 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_FRIEND_P (decl))
5102 /* For a friend, we want the context of the friend function, not
5103 the type of which it is a friend. */
5104 ctx = CP_DECL_CONTEXT (decl);
5105 else if (CP_DECL_CONTEXT (decl)
5106 && TREE_CODE (CP_DECL_CONTEXT (decl)) != NAMESPACE_DECL)
5107 /* In the case of a virtual function, we want the class in which
5109 ctx = CP_DECL_CONTEXT (decl);
5111 /* Otherwise, if we're currently defining some class, the DECL
5112 is assumed to be a member of the class. */
5113 ctx = current_scope ();
5115 if (ctx && TREE_CODE (ctx) == NAMESPACE_DECL)
5118 if (!DECL_CONTEXT (decl))
5119 DECL_CONTEXT (decl) = FROB_CONTEXT (current_namespace);
5121 /* See if this is a primary template. */
5122 if (is_friend && ctx
5123 && uses_template_parms_level (ctx, processing_template_decl))
5124 /* A friend template that specifies a class context, i.e.
5125 template <typename T> friend void A<T>::f();
5128 else if (TREE_CODE (decl) == TYPE_DECL
5129 && LAMBDA_TYPE_P (TREE_TYPE (decl)))
5132 is_primary = template_parm_scope_p ();
5136 warning (OPT_Wtemplates, "template %qD declared", decl);
5138 if (DECL_CLASS_SCOPE_P (decl))
5139 member_template_p = true;
5140 if (TREE_CODE (decl) == TYPE_DECL
5141 && anon_aggrname_p (DECL_NAME (decl)))
5143 error ("template class without a name");
5144 return error_mark_node;
5146 else if (TREE_CODE (decl) == FUNCTION_DECL)
5148 if (member_template_p)
5150 if (DECL_OVERRIDE_P (decl) || DECL_FINAL_P (decl))
5151 error ("member template %qD may not have virt-specifiers", decl);
5153 if (DECL_DESTRUCTOR_P (decl))
5157 A destructor shall not be a member template. */
5158 error ("destructor %qD declared as member template", decl);
5159 return error_mark_node;
5161 if (NEW_DELETE_OPNAME_P (DECL_NAME (decl))
5162 && (!prototype_p (TREE_TYPE (decl))
5163 || TYPE_ARG_TYPES (TREE_TYPE (decl)) == void_list_node
5164 || !TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (decl)))
5165 || (TREE_CHAIN (TYPE_ARG_TYPES ((TREE_TYPE (decl))))
5166 == void_list_node)))
5168 /* [basic.stc.dynamic.allocation]
5170 An allocation function can be a function
5171 template. ... Template allocation functions shall
5172 have two or more parameters. */
5173 error ("invalid template declaration of %qD", decl);
5174 return error_mark_node;
5177 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
5178 && CLASS_TYPE_P (TREE_TYPE (decl)))
5180 else if (TREE_CODE (decl) == TYPE_DECL
5181 && TYPE_DECL_ALIAS_P (decl))
5182 /* alias-declaration */
5183 gcc_assert (!DECL_ARTIFICIAL (decl));
5184 else if (VAR_P (decl))
5185 /* C++14 variable template. */;
5188 error ("template declaration of %q#D", decl);
5189 return error_mark_node;
5193 /* Check to see that the rules regarding the use of default
5194 arguments are not being violated. */
5195 check_default_tmpl_args (decl, current_template_parms,
5196 is_primary, is_partial, /*is_friend_decl=*/0);
5198 /* Ensure that there are no parameter packs in the type of this
5199 declaration that have not been expanded. */
5200 if (TREE_CODE (decl) == FUNCTION_DECL)
5202 /* Check each of the arguments individually to see if there are
5203 any bare parameter packs. */
5204 tree type = TREE_TYPE (decl);
5205 tree arg = DECL_ARGUMENTS (decl);
5206 tree argtype = TYPE_ARG_TYPES (type);
5208 while (arg && argtype)
5210 if (!DECL_PACK_P (arg)
5211 && check_for_bare_parameter_packs (TREE_TYPE (arg)))
5213 /* This is a PARM_DECL that contains unexpanded parameter
5214 packs. We have already complained about this in the
5215 check_for_bare_parameter_packs call, so just replace
5216 these types with ERROR_MARK_NODE. */
5217 TREE_TYPE (arg) = error_mark_node;
5218 TREE_VALUE (argtype) = error_mark_node;
5221 arg = DECL_CHAIN (arg);
5222 argtype = TREE_CHAIN (argtype);
5225 /* Check for bare parameter packs in the return type and the
5226 exception specifiers. */
5227 if (check_for_bare_parameter_packs (TREE_TYPE (type)))
5228 /* Errors were already issued, set return type to int
5229 as the frontend doesn't expect error_mark_node as
5231 TREE_TYPE (type) = integer_type_node;
5232 if (check_for_bare_parameter_packs (TYPE_RAISES_EXCEPTIONS (type)))
5233 TYPE_RAISES_EXCEPTIONS (type) = NULL_TREE;
5235 else if (check_for_bare_parameter_packs ((TREE_CODE (decl) == TYPE_DECL
5236 && TYPE_DECL_ALIAS_P (decl))
5237 ? DECL_ORIGINAL_TYPE (decl)
5238 : TREE_TYPE (decl)))
5240 TREE_TYPE (decl) = error_mark_node;
5241 return error_mark_node;
5245 return process_partial_specialization (decl);
5247 args = current_template_args ();
5250 || TREE_CODE (ctx) == FUNCTION_DECL
5251 || (CLASS_TYPE_P (ctx) && TYPE_BEING_DEFINED (ctx))
5252 || (TREE_CODE (decl) == TYPE_DECL
5253 && LAMBDA_TYPE_P (TREE_TYPE (decl)))
5254 || (is_friend && !DECL_TEMPLATE_INFO (decl)))
5256 if (DECL_LANG_SPECIFIC (decl)
5257 && DECL_TEMPLATE_INFO (decl)
5258 && DECL_TI_TEMPLATE (decl))
5259 tmpl = DECL_TI_TEMPLATE (decl);
5260 /* If DECL is a TYPE_DECL for a class-template, then there won't
5261 be DECL_LANG_SPECIFIC. The information equivalent to
5262 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
5263 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
5264 && TYPE_TEMPLATE_INFO (TREE_TYPE (decl))
5265 && TYPE_TI_TEMPLATE (TREE_TYPE (decl)))
5267 /* Since a template declaration already existed for this
5268 class-type, we must be redeclaring it here. Make sure
5269 that the redeclaration is valid. */
5270 redeclare_class_template (TREE_TYPE (decl),
5271 current_template_parms,
5272 current_template_constraints ());
5273 /* We don't need to create a new TEMPLATE_DECL; just use the
5274 one we already had. */
5275 tmpl = TYPE_TI_TEMPLATE (TREE_TYPE (decl));
5279 tmpl = build_template_decl (decl, current_template_parms,
5283 if (DECL_LANG_SPECIFIC (decl)
5284 && DECL_TEMPLATE_SPECIALIZATION (decl))
5286 /* A specialization of a member template of a template
5288 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
5289 DECL_TEMPLATE_INFO (tmpl) = DECL_TEMPLATE_INFO (decl);
5290 DECL_TEMPLATE_INFO (decl) = NULL_TREE;
5296 tree a, t, current, parms;
5298 tree tinfo = get_template_info (decl);
5302 error ("template definition of non-template %q#D", decl);
5303 return error_mark_node;
5306 tmpl = TI_TEMPLATE (tinfo);
5308 if (DECL_FUNCTION_TEMPLATE_P (tmpl)
5309 && DECL_TEMPLATE_INFO (decl) && DECL_TI_ARGS (decl)
5310 && DECL_TEMPLATE_SPECIALIZATION (decl)
5311 && DECL_MEMBER_TEMPLATE_P (tmpl))
5315 /* The declaration is a specialization of a member
5316 template, declared outside the class. Therefore, the
5317 innermost template arguments will be NULL, so we
5318 replace them with the arguments determined by the
5319 earlier call to check_explicit_specialization. */
5320 args = DECL_TI_ARGS (decl);
5323 = build_template_decl (decl, current_template_parms,
5325 DECL_TEMPLATE_RESULT (new_tmpl) = decl;
5326 TREE_TYPE (new_tmpl) = TREE_TYPE (decl);
5327 DECL_TI_TEMPLATE (decl) = new_tmpl;
5328 SET_DECL_TEMPLATE_SPECIALIZATION (new_tmpl);
5329 DECL_TEMPLATE_INFO (new_tmpl)
5330 = build_template_info (tmpl, args);
5332 register_specialization (new_tmpl,
5333 most_general_template (tmpl),
5339 /* Make sure the template headers we got make sense. */
5341 parms = DECL_TEMPLATE_PARMS (tmpl);
5342 i = TMPL_PARMS_DEPTH (parms);
5343 if (TMPL_ARGS_DEPTH (args) != i)
5345 error ("expected %d levels of template parms for %q#D, got %d",
5346 i, decl, TMPL_ARGS_DEPTH (args));
5347 DECL_INTERFACE_KNOWN (decl) = 1;
5348 return error_mark_node;
5351 for (current = decl; i > 0; --i, parms = TREE_CHAIN (parms))
5353 a = TMPL_ARGS_LEVEL (args, i);
5354 t = INNERMOST_TEMPLATE_PARMS (parms);
5356 if (TREE_VEC_LENGTH (t) != TREE_VEC_LENGTH (a))
5358 if (current == decl)
5359 error ("got %d template parameters for %q#D",
5360 TREE_VEC_LENGTH (a), decl);
5362 error ("got %d template parameters for %q#T",
5363 TREE_VEC_LENGTH (a), current);
5364 error (" but %d required", TREE_VEC_LENGTH (t));
5365 /* Avoid crash in import_export_decl. */
5366 DECL_INTERFACE_KNOWN (decl) = 1;
5367 return error_mark_node;
5370 if (current == decl)
5372 else if (current == NULL_TREE)
5373 /* Can happen in erroneous input. */
5376 current = get_containing_scope (current);
5379 /* Check that the parms are used in the appropriate qualifying scopes
5380 in the declarator. */
5381 if (!comp_template_args
5383 TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (tmpl)))))
5386 template arguments to %qD do not match original template %qD",
5387 decl, DECL_TEMPLATE_RESULT (tmpl));
5388 if (!uses_template_parms (TI_ARGS (tinfo)))
5389 inform (input_location, "use template<> for an explicit specialization");
5390 /* Avoid crash in import_export_decl. */
5391 DECL_INTERFACE_KNOWN (decl) = 1;
5392 return error_mark_node;
5396 DECL_TEMPLATE_RESULT (tmpl) = decl;
5397 TREE_TYPE (tmpl) = TREE_TYPE (decl);
5399 /* Push template declarations for global functions and types. Note
5400 that we do not try to push a global template friend declared in a
5401 template class; such a thing may well depend on the template
5402 parameters of the class. */
5403 if (new_template_p && !ctx
5404 && !(is_friend && template_class_depth (current_class_type) > 0))
5406 tmpl = pushdecl_namespace_level (tmpl, is_friend);
5407 if (tmpl == error_mark_node)
5408 return error_mark_node;
5410 /* Hide template friend classes that haven't been declared yet. */
5411 if (is_friend && TREE_CODE (decl) == TYPE_DECL)
5413 DECL_ANTICIPATED (tmpl) = 1;
5414 DECL_FRIEND_P (tmpl) = 1;
5420 tree parms = DECL_TEMPLATE_PARMS (tmpl);
5423 DECL_PRIMARY_TEMPLATE (tmpl) = tmpl;
5424 if (DECL_CONV_FN_P (tmpl))
5426 int depth = TMPL_PARMS_DEPTH (parms);
5428 /* It is a conversion operator. See if the type converted to
5429 depends on innermost template operands. */
5431 if (uses_template_parms_level (TREE_TYPE (TREE_TYPE (tmpl)),
5433 DECL_TEMPLATE_CONV_FN_P (tmpl) = 1;
5436 /* Give template template parms a DECL_CONTEXT of the template
5437 for which they are a parameter. */
5438 parms = INNERMOST_TEMPLATE_PARMS (parms);
5439 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
5441 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
5442 if (TREE_CODE (parm) == TEMPLATE_DECL)
5443 DECL_CONTEXT (parm) = tmpl;
5446 if (TREE_CODE (decl) == TYPE_DECL
5447 && TYPE_DECL_ALIAS_P (decl)
5448 && complex_alias_template_p (tmpl))
5449 TEMPLATE_DECL_COMPLEX_ALIAS_P (tmpl) = true;
5452 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5453 back to its most general template. If TMPL is a specialization,
5454 ARGS may only have the innermost set of arguments. Add the missing
5455 argument levels if necessary. */
5456 if (DECL_TEMPLATE_INFO (tmpl))
5457 args = add_outermost_template_args (DECL_TI_ARGS (tmpl), args);
5459 info = build_template_info (tmpl, args);
5461 if (DECL_IMPLICIT_TYPEDEF_P (decl))
5462 SET_TYPE_TEMPLATE_INFO (TREE_TYPE (tmpl), info);
5465 if (is_primary && !DECL_LANG_SPECIFIC (decl))
5466 retrofit_lang_decl (decl);
5467 if (DECL_LANG_SPECIFIC (decl))
5468 DECL_TEMPLATE_INFO (decl) = info;
5471 if (flag_implicit_templates
5473 && TREE_PUBLIC (decl)
5474 && VAR_OR_FUNCTION_DECL_P (decl))
5475 /* Set DECL_COMDAT on template instantiations; if we force
5476 them to be emitted by explicit instantiation or -frepo,
5477 mark_needed will tell cgraph to do the right thing. */
5478 DECL_COMDAT (decl) = true;
5480 return DECL_TEMPLATE_RESULT (tmpl);
5484 push_template_decl (tree decl)
5486 return push_template_decl_real (decl, false);
5489 /* FN is an inheriting constructor that inherits from the constructor
5490 template INHERITED; turn FN into a constructor template with a matching
5494 add_inherited_template_parms (tree fn, tree inherited)
5497 = INNERMOST_TEMPLATE_PARMS (DECL_TEMPLATE_PARMS (inherited));
5498 inner_parms = copy_node (inner_parms);
5500 = tree_cons (size_int (processing_template_decl + 1),
5501 inner_parms, current_template_parms);
5502 tree tmpl = build_template_decl (fn, parms, /*member*/true);
5503 tree args = template_parms_to_args (parms);
5504 DECL_TEMPLATE_INFO (fn) = build_template_info (tmpl, args);
5505 TREE_TYPE (tmpl) = TREE_TYPE (fn);
5506 DECL_TEMPLATE_RESULT (tmpl) = fn;
5507 DECL_ARTIFICIAL (tmpl) = true;
5508 DECL_PRIMARY_TEMPLATE (tmpl) = tmpl;
5512 /* Called when a class template TYPE is redeclared with the indicated
5513 template PARMS, e.g.:
5515 template <class T> struct S;
5516 template <class T> struct S {}; */
5519 redeclare_class_template (tree type, tree parms, tree cons)
5525 if (!TYPE_TEMPLATE_INFO (type))
5527 error ("%qT is not a template type", type);
5531 tmpl = TYPE_TI_TEMPLATE (type);
5532 if (!PRIMARY_TEMPLATE_P (tmpl))
5533 /* The type is nested in some template class. Nothing to worry
5534 about here; there are no new template parameters for the nested
5540 error ("template specifiers not specified in declaration of %qD",
5545 parms = INNERMOST_TEMPLATE_PARMS (parms);
5546 tmpl_parms = DECL_INNERMOST_TEMPLATE_PARMS (tmpl);
5548 if (TREE_VEC_LENGTH (parms) != TREE_VEC_LENGTH (tmpl_parms))
5550 error_n (input_location, TREE_VEC_LENGTH (parms),
5551 "redeclared with %d template parameter",
5552 "redeclared with %d template parameters",
5553 TREE_VEC_LENGTH (parms));
5554 inform_n (DECL_SOURCE_LOCATION (tmpl), TREE_VEC_LENGTH (tmpl_parms),
5555 "previous declaration %qD used %d template parameter",
5556 "previous declaration %qD used %d template parameters",
5557 tmpl, TREE_VEC_LENGTH (tmpl_parms));
5561 for (i = 0; i < TREE_VEC_LENGTH (tmpl_parms); ++i)
5568 if (TREE_VEC_ELT (tmpl_parms, i) == error_mark_node
5569 || TREE_VEC_ELT (parms, i) == error_mark_node)
5572 tmpl_parm = TREE_VALUE (TREE_VEC_ELT (tmpl_parms, i));
5573 if (error_operand_p (tmpl_parm))
5576 parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
5577 tmpl_default = TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i));
5578 parm_default = TREE_PURPOSE (TREE_VEC_ELT (parms, i));
5580 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5582 if (TREE_CODE (tmpl_parm) != TREE_CODE (parm)
5583 || (TREE_CODE (tmpl_parm) != TYPE_DECL
5584 && !same_type_p (TREE_TYPE (tmpl_parm), TREE_TYPE (parm)))
5585 || (TREE_CODE (tmpl_parm) != PARM_DECL
5586 && (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (tmpl_parm))
5587 != TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm))))
5588 || (TREE_CODE (tmpl_parm) == PARM_DECL
5589 && (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (tmpl_parm))
5590 != TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))))
5592 error ("template parameter %q+#D", tmpl_parm);
5593 error ("redeclared here as %q#D", parm);
5597 if (tmpl_default != NULL_TREE && parm_default != NULL_TREE)
5599 /* We have in [temp.param]:
5601 A template-parameter may not be given default arguments
5602 by two different declarations in the same scope. */
5603 error_at (input_location, "redefinition of default argument for %q#D", parm);
5604 inform (DECL_SOURCE_LOCATION (tmpl_parm),
5605 "original definition appeared here");
5609 if (parm_default != NULL_TREE)
5610 /* Update the previous template parameters (which are the ones
5611 that will really count) with the new default value. */
5612 TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i)) = parm_default;
5613 else if (tmpl_default != NULL_TREE)
5614 /* Update the new parameters, too; they'll be used as the
5615 parameters for any members. */
5616 TREE_PURPOSE (TREE_VEC_ELT (parms, i)) = tmpl_default;
5618 /* Give each template template parm in this redeclaration a
5619 DECL_CONTEXT of the template for which they are a parameter. */
5620 if (TREE_CODE (parm) == TEMPLATE_DECL)
5622 gcc_assert (DECL_CONTEXT (parm) == NULL_TREE);
5623 DECL_CONTEXT (parm) = tmpl;
5627 // Cannot redeclare a class template with a different set of constraints.
5628 if (!equivalent_constraints (get_constraints (tmpl), cons))
5630 error_at (input_location, "redeclaration %q#D with different "
5631 "constraints", tmpl);
5632 inform (DECL_SOURCE_LOCATION (tmpl),
5633 "original declaration appeared here");
5639 /* The actual substitution part of instantiate_non_dependent_expr_sfinae,
5640 to be used when the caller has already checked
5641 (processing_template_decl
5642 && !instantiation_dependent_expression_p (expr)
5643 && potential_constant_expression (expr))
5644 and cleared processing_template_decl. */
5647 instantiate_non_dependent_expr_internal (tree expr, tsubst_flags_t complain)
5649 return tsubst_copy_and_build (expr,
5652 /*in_decl=*/NULL_TREE,
5653 /*function_p=*/false,
5654 /*integral_constant_expression_p=*/true);
5657 /* Simplify EXPR if it is a non-dependent expression. Returns the
5658 (possibly simplified) expression. */
5661 instantiate_non_dependent_expr_sfinae (tree expr, tsubst_flags_t complain)
5663 if (expr == NULL_TREE)
5666 /* If we're in a template, but EXPR isn't value dependent, simplify
5667 it. We're supposed to treat:
5669 template <typename T> void f(T[1 + 1]);
5670 template <typename T> void f(T[2]);
5672 as two declarations of the same function, for example. */
5673 if (processing_template_decl
5674 && potential_nondependent_constant_expression (expr))
5676 processing_template_decl_sentinel s;
5677 expr = instantiate_non_dependent_expr_internal (expr, complain);
5683 instantiate_non_dependent_expr (tree expr)
5685 return instantiate_non_dependent_expr_sfinae (expr, tf_error);
5688 /* Like instantiate_non_dependent_expr, but return NULL_TREE rather than
5689 an uninstantiated expression. */
5692 instantiate_non_dependent_or_null (tree expr)
5694 if (expr == NULL_TREE)
5696 if (processing_template_decl)
5698 if (!potential_nondependent_constant_expression (expr))
5702 processing_template_decl_sentinel s;
5703 expr = instantiate_non_dependent_expr_internal (expr, tf_error);
5709 /* True iff T is a specialization of a variable template. */
5712 variable_template_specialization_p (tree t)
5714 if (!VAR_P (t) || !DECL_LANG_SPECIFIC (t) || !DECL_TEMPLATE_INFO (t))
5716 tree tmpl = DECL_TI_TEMPLATE (t);
5717 return variable_template_p (tmpl);
5720 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5721 template declaration, or a TYPE_DECL for an alias declaration. */
5724 alias_type_or_template_p (tree t)
5728 return ((TREE_CODE (t) == TYPE_DECL && TYPE_DECL_ALIAS_P (t))
5731 && TYPE_DECL_ALIAS_P (TYPE_NAME (t)))
5732 || DECL_ALIAS_TEMPLATE_P (t));
5735 /* Return TRUE iff T is a specialization of an alias template. */
5738 alias_template_specialization_p (const_tree t)
5740 /* It's an alias template specialization if it's an alias and its
5741 TYPE_NAME is a specialization of a primary template. */
5742 if (TYPE_ALIAS_P (t))
5744 tree name = TYPE_NAME (t);
5745 if (DECL_LANG_SPECIFIC (name))
5746 if (tree ti = DECL_TEMPLATE_INFO (name))
5748 tree tmpl = TI_TEMPLATE (ti);
5749 return PRIMARY_TEMPLATE_P (tmpl);
5755 /* An alias template is complex from a SFINAE perspective if a template-id
5756 using that alias can be ill-formed when the expansion is not, as with
5757 the void_t template. We determine this by checking whether the
5758 expansion for the alias template uses all its template parameters. */
5760 struct uses_all_template_parms_data
5767 uses_all_template_parms_r (tree t, void *data_)
5769 struct uses_all_template_parms_data &data
5770 = *(struct uses_all_template_parms_data*)data_;
5771 tree idx = get_template_parm_index (t);
5773 if (TEMPLATE_PARM_LEVEL (idx) == data.level)
5774 data.seen[TEMPLATE_PARM_IDX (idx)] = true;
5779 complex_alias_template_p (const_tree tmpl)
5781 struct uses_all_template_parms_data data;
5782 tree pat = DECL_ORIGINAL_TYPE (DECL_TEMPLATE_RESULT (tmpl));
5783 tree parms = DECL_TEMPLATE_PARMS (tmpl);
5784 data.level = TMPL_PARMS_DEPTH (parms);
5785 int len = TREE_VEC_LENGTH (INNERMOST_TEMPLATE_PARMS (parms));
5786 data.seen = XALLOCAVEC (bool, len);
5787 for (int i = 0; i < len; ++i)
5788 data.seen[i] = false;
5790 for_each_template_parm (pat, uses_all_template_parms_r, &data, NULL, true);
5791 for (int i = 0; i < len; ++i)
5797 /* Return TRUE iff T is a specialization of a complex alias template with
5798 dependent template-arguments. */
5801 dependent_alias_template_spec_p (const_tree t)
5803 return (alias_template_specialization_p (t)
5804 && TEMPLATE_DECL_COMPLEX_ALIAS_P (DECL_TI_TEMPLATE (TYPE_NAME (t)))
5805 && (any_dependent_template_arguments_p
5806 (INNERMOST_TEMPLATE_ARGS (TYPE_TI_ARGS (t)))));
5809 /* Return the number of innermost template parameters in TMPL. */
5812 num_innermost_template_parms (tree tmpl)
5814 tree parms = INNERMOST_TEMPLATE_PARMS (DECL_TEMPLATE_PARMS (tmpl));
5815 return TREE_VEC_LENGTH (parms);
5818 /* Return either TMPL or another template that it is equivalent to under DR
5819 1286: An alias that just changes the name of a template is equivalent to
5820 the other template. */
5823 get_underlying_template (tree tmpl)
5825 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
5826 while (DECL_ALIAS_TEMPLATE_P (tmpl))
5828 tree result = DECL_ORIGINAL_TYPE (DECL_TEMPLATE_RESULT (tmpl));
5829 if (TYPE_TEMPLATE_INFO (result))
5831 tree sub = TYPE_TI_TEMPLATE (result);
5832 if (PRIMARY_TEMPLATE_P (sub)
5833 && (num_innermost_template_parms (tmpl)
5834 == num_innermost_template_parms (sub)))
5836 tree alias_args = INNERMOST_TEMPLATE_ARGS
5837 (template_parms_to_args (DECL_TEMPLATE_PARMS (tmpl)));
5838 if (!comp_template_args (TYPE_TI_ARGS (result), alias_args))
5840 /* The alias type is equivalent to the pattern of the
5841 underlying template, so strip the alias. */
5851 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5852 must be a function or a pointer-to-function type, as specified
5853 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5854 and check that the resulting function has external linkage. */
5857 convert_nontype_argument_function (tree type, tree expr,
5858 tsubst_flags_t complain)
5862 linkage_kind linkage;
5864 fn = instantiate_type (type, fns, tf_none);
5865 if (fn == error_mark_node)
5866 return error_mark_node;
5869 if (TREE_CODE (fn_no_ptr) == ADDR_EXPR)
5870 fn_no_ptr = TREE_OPERAND (fn_no_ptr, 0);
5871 if (BASELINK_P (fn_no_ptr))
5872 fn_no_ptr = BASELINK_FUNCTIONS (fn_no_ptr);
5874 /* [temp.arg.nontype]/1
5876 A template-argument for a non-type, non-template template-parameter
5879 -- the address of an object or function with external [C++11: or
5880 internal] linkage. */
5882 if (TREE_CODE (fn_no_ptr) != FUNCTION_DECL)
5884 if (complain & tf_error)
5886 error ("%qE is not a valid template argument for type %qT",
5888 if (TYPE_PTR_P (type))
5889 error ("it must be the address of a function with "
5890 "external linkage");
5892 error ("it must be the name of a function with "
5893 "external linkage");
5898 linkage = decl_linkage (fn_no_ptr);
5899 if (cxx_dialect >= cxx11 ? linkage == lk_none : linkage != lk_external)
5901 if (complain & tf_error)
5903 if (cxx_dialect >= cxx11)
5904 error ("%qE is not a valid template argument for type %qT "
5905 "because %qD has no linkage",
5906 expr, type, fn_no_ptr);
5908 error ("%qE is not a valid template argument for type %qT "
5909 "because %qD does not have external linkage",
5910 expr, type, fn_no_ptr);
5918 /* Subroutine of convert_nontype_argument.
5919 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5920 Emit an error otherwise. */
5923 check_valid_ptrmem_cst_expr (tree type, tree expr,
5924 tsubst_flags_t complain)
5927 if (expr && (null_ptr_cst_p (expr) || TREE_CODE (expr) == PTRMEM_CST))
5929 if (cxx_dialect >= cxx11 && null_member_pointer_value_p (expr))
5931 if (processing_template_decl
5932 && TREE_CODE (expr) == ADDR_EXPR
5933 && TREE_CODE (TREE_OPERAND (expr, 0)) == OFFSET_REF)
5935 if (complain & tf_error)
5937 error ("%qE is not a valid template argument for type %qT",
5939 error ("it must be a pointer-to-member of the form %<&X::Y%>");
5944 /* Returns TRUE iff the address of OP is value-dependent.
5946 14.6.2.4 [temp.dep.temp]:
5947 A non-integral non-type template-argument is dependent if its type is
5948 dependent or it has either of the following forms
5951 and contains a nested-name-specifier which specifies a class-name that
5952 names a dependent type.
5954 We generalize this to just say that the address of a member of a
5955 dependent class is value-dependent; the above doesn't cover the
5956 address of a static data member named with an unqualified-id. */
5959 has_value_dependent_address (tree op)
5961 /* We could use get_inner_reference here, but there's no need;
5962 this is only relevant for template non-type arguments, which
5963 can only be expressed as &id-expression. */
5966 tree ctx = CP_DECL_CONTEXT (op);
5967 if (TYPE_P (ctx) && dependent_type_p (ctx))
5974 /* The next set of functions are used for providing helpful explanatory
5975 diagnostics for failed overload resolution. Their messages should be
5976 indented by two spaces for consistency with the messages in
5980 unify_success (bool /*explain_p*/)
5986 unify_parameter_deduction_failure (bool explain_p, tree parm)
5989 inform (input_location,
5990 " couldn't deduce template parameter %qD", parm);
5995 unify_invalid (bool /*explain_p*/)
6001 unify_cv_qual_mismatch (bool explain_p, tree parm, tree arg)
6004 inform (input_location,
6005 " types %qT and %qT have incompatible cv-qualifiers",
6011 unify_type_mismatch (bool explain_p, tree parm, tree arg)
6014 inform (input_location, " mismatched types %qT and %qT", parm, arg);
6019 unify_parameter_pack_mismatch (bool explain_p, tree parm, tree arg)
6022 inform (input_location,
6023 " template parameter %qD is not a parameter pack, but "
6030 unify_ptrmem_cst_mismatch (bool explain_p, tree parm, tree arg)
6033 inform (input_location,
6034 " template argument %qE does not match "
6035 "pointer-to-member constant %qE",
6041 unify_expression_unequal (bool explain_p, tree parm, tree arg)
6044 inform (input_location, " %qE is not equivalent to %qE", parm, arg);
6049 unify_parameter_pack_inconsistent (bool explain_p, tree old_arg, tree new_arg)
6052 inform (input_location,
6053 " inconsistent parameter pack deduction with %qT and %qT",
6059 unify_inconsistency (bool explain_p, tree parm, tree first, tree second)
6064 inform (input_location,
6065 " deduced conflicting types for parameter %qT (%qT and %qT)",
6066 parm, first, second);
6068 inform (input_location,
6069 " deduced conflicting values for non-type parameter "
6070 "%qE (%qE and %qE)", parm, first, second);
6076 unify_vla_arg (bool explain_p, tree arg)
6079 inform (input_location,
6080 " variable-sized array type %qT is not "
6081 "a valid template argument",
6087 unify_method_type_error (bool explain_p, tree arg)
6090 inform (input_location,
6091 " member function type %qT is not a valid template argument",
6097 unify_arity (bool explain_p, int have, int wanted, bool least_p = false)
6102 inform_n (input_location, wanted,
6103 " candidate expects at least %d argument, %d provided",
6104 " candidate expects at least %d arguments, %d provided",
6107 inform_n (input_location, wanted,
6108 " candidate expects %d argument, %d provided",
6109 " candidate expects %d arguments, %d provided",
6116 unify_too_many_arguments (bool explain_p, int have, int wanted)
6118 return unify_arity (explain_p, have, wanted);
6122 unify_too_few_arguments (bool explain_p, int have, int wanted,
6123 bool least_p = false)
6125 return unify_arity (explain_p, have, wanted, least_p);
6129 unify_arg_conversion (bool explain_p, tree to_type,
6130 tree from_type, tree arg)
6133 inform (EXPR_LOC_OR_LOC (arg, input_location),
6134 " cannot convert %qE (type %qT) to type %qT",
6135 arg, from_type, to_type);
6140 unify_no_common_base (bool explain_p, enum template_base_result r,
6141 tree parm, tree arg)
6146 case tbr_ambiguous_baseclass:
6147 inform (input_location, " %qT is an ambiguous base class of %qT",
6151 inform (input_location, " %qT is not derived from %qT", arg, parm);
6158 unify_inconsistent_template_template_parameters (bool explain_p)
6161 inform (input_location,
6162 " template parameters of a template template argument are "
6163 "inconsistent with other deduced template arguments");
6168 unify_template_deduction_failure (bool explain_p, tree parm, tree arg)
6171 inform (input_location,
6172 " can't deduce a template for %qT from non-template type %qT",
6178 unify_template_argument_mismatch (bool explain_p, tree parm, tree arg)
6181 inform (input_location,
6182 " template argument %qE does not match %qD", arg, parm);
6187 unify_overload_resolution_failure (bool explain_p, tree arg)
6190 inform (input_location,
6191 " could not resolve address from overloaded function %qE",
6196 /* Attempt to convert the non-type template parameter EXPR to the
6197 indicated TYPE. If the conversion is successful, return the
6198 converted value. If the conversion is unsuccessful, return
6199 NULL_TREE if we issued an error message, or error_mark_node if we
6200 did not. We issue error messages for out-and-out bad template
6201 parameters, but not simply because the conversion failed, since we
6202 might be just trying to do argument deduction. Both TYPE and EXPR
6203 must be non-dependent.
6205 The conversion follows the special rules described in
6206 [temp.arg.nontype], and it is much more strict than an implicit
6209 This function is called twice for each template argument (see
6210 lookup_template_class for a more accurate description of this
6211 problem). This means that we need to handle expressions which
6212 are not valid in a C++ source, but can be created from the
6213 first call (for instance, casts to perform conversions). These
6214 hacks can go away after we fix the double coercion problem. */
6217 convert_nontype_argument (tree type, tree expr, tsubst_flags_t complain)
6221 /* Detect immediately string literals as invalid non-type argument.
6222 This special-case is not needed for correctness (we would easily
6223 catch this later), but only to provide better diagnostic for this
6224 common user mistake. As suggested by DR 100, we do not mention
6225 linkage issues in the diagnostic as this is not the point. */
6226 /* FIXME we're making this OK. */
6227 if (TREE_CODE (expr) == STRING_CST)
6229 if (complain & tf_error)
6230 error ("%qE is not a valid template argument for type %qT "
6231 "because string literals can never be used in this context",
6236 /* Add the ADDR_EXPR now for the benefit of
6237 value_dependent_expression_p. */
6238 if (TYPE_PTROBV_P (type)
6239 && TREE_CODE (TREE_TYPE (expr)) == ARRAY_TYPE)
6241 expr = decay_conversion (expr, complain);
6242 if (expr == error_mark_node)
6243 return error_mark_node;
6246 /* If we are in a template, EXPR may be non-dependent, but still
6247 have a syntactic, rather than semantic, form. For example, EXPR
6248 might be a SCOPE_REF, rather than the VAR_DECL to which the
6249 SCOPE_REF refers. Preserving the qualifying scope is necessary
6250 so that access checking can be performed when the template is
6251 instantiated -- but here we need the resolved form so that we can
6252 convert the argument. */
6253 bool non_dep = false;
6254 if (TYPE_REF_OBJ_P (type)
6255 && has_value_dependent_address (expr))
6256 /* If we want the address and it's value-dependent, don't fold. */;
6257 else if (processing_template_decl
6258 && potential_nondependent_constant_expression (expr))
6260 if (error_operand_p (expr))
6261 return error_mark_node;
6262 expr_type = TREE_TYPE (expr);
6263 if (TREE_CODE (type) == REFERENCE_TYPE)
6264 expr = mark_lvalue_use (expr);
6266 expr = mark_rvalue_use (expr);
6268 /* If the argument is non-dependent, perform any conversions in
6269 non-dependent context as well. */
6270 processing_template_decl_sentinel s (non_dep);
6272 expr = instantiate_non_dependent_expr_internal (expr, complain);
6274 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
6275 to a non-type argument of "nullptr". */
6276 if (expr == nullptr_node && TYPE_PTR_OR_PTRMEM_P (type))
6277 expr = fold_simple (convert (type, expr));
6279 /* In C++11, integral or enumeration non-type template arguments can be
6280 arbitrary constant expressions. Pointer and pointer to
6281 member arguments can be general constant expressions that evaluate
6282 to a null value, but otherwise still need to be of a specific form. */
6283 if (cxx_dialect >= cxx11)
6285 if (TREE_CODE (expr) == PTRMEM_CST)
6286 /* A PTRMEM_CST is already constant, and a valid template
6287 argument for a parameter of pointer to member type, we just want
6288 to leave it in that form rather than lower it to a
6290 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
6291 expr = maybe_constant_value (expr);
6292 else if (cxx_dialect >= cxx1z)
6294 if (TREE_CODE (type) != REFERENCE_TYPE)
6295 expr = maybe_constant_value (expr);
6296 else if (REFERENCE_REF_P (expr))
6298 expr = TREE_OPERAND (expr, 0);
6299 expr = maybe_constant_value (expr);
6300 expr = convert_from_reference (expr);
6303 else if (TYPE_PTR_OR_PTRMEM_P (type))
6305 tree folded = maybe_constant_value (expr);
6306 if (TYPE_PTR_P (type) ? integer_zerop (folded)
6307 : null_member_pointer_value_p (folded))
6312 /* HACK: Due to double coercion, we can get a
6313 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
6314 which is the tree that we built on the first call (see
6315 below when coercing to reference to object or to reference to
6316 function). We just strip everything and get to the arg.
6317 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
6319 if (TYPE_REF_OBJ_P (type) || TYPE_REFFN_P (type))
6321 tree probe_type, probe = expr;
6322 if (REFERENCE_REF_P (probe))
6323 probe = TREE_OPERAND (probe, 0);
6324 probe_type = TREE_TYPE (probe);
6325 if (TREE_CODE (probe) == NOP_EXPR)
6327 /* ??? Maybe we could use convert_from_reference here, but we
6328 would need to relax its constraints because the NOP_EXPR
6329 could actually change the type to something more cv-qualified,
6330 and this is not folded by convert_from_reference. */
6331 tree addr = TREE_OPERAND (probe, 0);
6332 if (TREE_CODE (probe_type) == REFERENCE_TYPE
6333 && TREE_CODE (addr) == ADDR_EXPR
6334 && TYPE_PTR_P (TREE_TYPE (addr))
6335 && (same_type_ignoring_top_level_qualifiers_p
6336 (TREE_TYPE (probe_type),
6337 TREE_TYPE (TREE_TYPE (addr)))))
6339 expr = TREE_OPERAND (addr, 0);
6340 expr_type = TREE_TYPE (probe_type);
6345 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
6346 parameter is a pointer to object, through decay and
6347 qualification conversion. Let's strip everything. */
6348 else if (TREE_CODE (expr) == NOP_EXPR && TYPE_PTROBV_P (type))
6352 if (TREE_CODE (probe) == ADDR_EXPR
6353 && TYPE_PTR_P (TREE_TYPE (probe)))
6355 /* Skip the ADDR_EXPR only if it is part of the decay for
6356 an array. Otherwise, it is part of the original argument
6357 in the source code. */
6358 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (probe, 0))) == ARRAY_TYPE)
6359 probe = TREE_OPERAND (probe, 0);
6361 expr_type = TREE_TYPE (expr);
6365 /* [temp.arg.nontype]/5, bullet 1
6367 For a non-type template-parameter of integral or enumeration type,
6368 integral promotions (_conv.prom_) and integral conversions
6369 (_conv.integral_) are applied. */
6370 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
6372 tree t = build_integral_nontype_arg_conv (type, expr, complain);
6373 t = maybe_constant_value (t);
6374 if (t != error_mark_node)
6377 if (!same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (expr)))
6378 return error_mark_node;
6380 /* Notice that there are constant expressions like '4 % 0' which
6381 do not fold into integer constants. */
6382 if (TREE_CODE (expr) != INTEGER_CST)
6384 if (complain & tf_error)
6386 int errs = errorcount, warns = warningcount + werrorcount;
6387 if (processing_template_decl
6388 && !require_potential_constant_expression (expr))
6390 expr = cxx_constant_value (expr);
6391 if (errorcount > errs || warningcount + werrorcount > warns)
6392 inform (EXPR_LOC_OR_LOC (expr, input_location),
6393 "in template argument for type %qT ", type);
6394 if (expr == error_mark_node)
6396 /* else cxx_constant_value complained but gave us
6397 a real constant, so go ahead. */
6398 gcc_assert (TREE_CODE (expr) == INTEGER_CST);
6404 /* Avoid typedef problems. */
6405 if (TREE_TYPE (expr) != type)
6406 expr = fold_convert (type, expr);
6408 /* [temp.arg.nontype]/5, bullet 2
6410 For a non-type template-parameter of type pointer to object,
6411 qualification conversions (_conv.qual_) and the array-to-pointer
6412 conversion (_conv.array_) are applied. */
6413 else if (TYPE_PTROBV_P (type))
6415 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
6417 A template-argument for a non-type, non-template template-parameter
6418 shall be one of: [...]
6420 -- the name of a non-type template-parameter;
6421 -- the address of an object or function with external linkage, [...]
6422 expressed as "& id-expression" where the & is optional if the name
6423 refers to a function or array, or if the corresponding
6424 template-parameter is a reference.
6426 Here, we do not care about functions, as they are invalid anyway
6427 for a parameter of type pointer-to-object. */
6429 if (DECL_P (expr) && DECL_TEMPLATE_PARM_P (expr))
6430 /* Non-type template parameters are OK. */
6432 else if (cxx_dialect >= cxx11 && integer_zerop (expr))
6433 /* Null pointer values are OK in C++11. */;
6434 else if (TREE_CODE (expr) != ADDR_EXPR
6435 && TREE_CODE (expr_type) != ARRAY_TYPE)
6439 if (complain & tf_error)
6440 error ("%qD is not a valid template argument "
6441 "because %qD is a variable, not the address of "
6442 "a variable", expr, expr);
6445 if (POINTER_TYPE_P (expr_type))
6447 if (complain & tf_error)
6448 error ("%qE is not a valid template argument for %qT "
6449 "because it is not the address of a variable",
6453 /* Other values, like integer constants, might be valid
6454 non-type arguments of some other type. */
6455 return error_mark_node;
6461 decl = ((TREE_CODE (expr) == ADDR_EXPR)
6462 ? TREE_OPERAND (expr, 0) : expr);
6465 if (complain & tf_error)
6466 error ("%qE is not a valid template argument of type %qT "
6467 "because %qE is not a variable", expr, type, decl);
6470 else if (cxx_dialect < cxx11 && !DECL_EXTERNAL_LINKAGE_P (decl))
6472 if (complain & tf_error)
6473 error ("%qE is not a valid template argument of type %qT "
6474 "because %qD does not have external linkage",
6478 else if (cxx_dialect >= cxx11 && decl_linkage (decl) == lk_none)
6480 if (complain & tf_error)
6481 error ("%qE is not a valid template argument of type %qT "
6482 "because %qD has no linkage", expr, type, decl);
6487 expr = decay_conversion (expr, complain);
6488 if (expr == error_mark_node)
6489 return error_mark_node;
6491 expr = perform_qualification_conversions (type, expr);
6492 if (expr == error_mark_node)
6493 return error_mark_node;
6495 /* [temp.arg.nontype]/5, bullet 3
6497 For a non-type template-parameter of type reference to object, no
6498 conversions apply. The type referred to by the reference may be more
6499 cv-qualified than the (otherwise identical) type of the
6500 template-argument. The template-parameter is bound directly to the
6501 template-argument, which must be an lvalue. */
6502 else if (TYPE_REF_OBJ_P (type))
6504 if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type),
6506 return error_mark_node;
6508 if (!at_least_as_qualified_p (TREE_TYPE (type), expr_type))
6510 if (complain & tf_error)
6511 error ("%qE is not a valid template argument for type %qT "
6512 "because of conflicts in cv-qualification", expr, type);
6516 if (!real_lvalue_p (expr))
6518 if (complain & tf_error)
6519 error ("%qE is not a valid template argument for type %qT "
6520 "because it is not an lvalue", expr, type);
6524 /* [temp.arg.nontype]/1
6526 A template-argument for a non-type, non-template template-parameter
6527 shall be one of: [...]
6529 -- the address of an object or function with external linkage. */
6530 if (INDIRECT_REF_P (expr)
6531 && TYPE_REF_OBJ_P (TREE_TYPE (TREE_OPERAND (expr, 0))))
6533 expr = TREE_OPERAND (expr, 0);
6536 if (complain & tf_error)
6537 error ("%q#D is not a valid template argument for type %qT "
6538 "because a reference variable does not have a constant "
6539 "address", expr, type);
6546 if (complain & tf_error)
6547 error ("%qE is not a valid template argument for type %qT "
6548 "because it is not an object with linkage",
6553 /* DR 1155 allows internal linkage in C++11 and up. */
6554 linkage_kind linkage = decl_linkage (expr);
6555 if (linkage < (cxx_dialect >= cxx11 ? lk_internal : lk_external))
6557 if (complain & tf_error)
6558 error ("%qE is not a valid template argument for type %qT "
6559 "because object %qD does not have linkage",
6564 expr = build_nop (type, build_address (expr));
6566 /* [temp.arg.nontype]/5, bullet 4
6568 For a non-type template-parameter of type pointer to function, only
6569 the function-to-pointer conversion (_conv.func_) is applied. If the
6570 template-argument represents a set of overloaded functions (or a
6571 pointer to such), the matching function is selected from the set
6573 else if (TYPE_PTRFN_P (type))
6575 /* If the argument is a template-id, we might not have enough
6576 context information to decay the pointer. */
6577 if (!type_unknown_p (expr_type))
6579 expr = decay_conversion (expr, complain);
6580 if (expr == error_mark_node)
6581 return error_mark_node;
6584 if (cxx_dialect >= cxx11 && integer_zerop (expr))
6585 /* Null pointer values are OK in C++11. */
6586 return perform_qualification_conversions (type, expr);
6588 expr = convert_nontype_argument_function (type, expr, complain);
6589 if (!expr || expr == error_mark_node)
6592 /* [temp.arg.nontype]/5, bullet 5
6594 For a non-type template-parameter of type reference to function, no
6595 conversions apply. If the template-argument represents a set of
6596 overloaded functions, the matching function is selected from the set
6598 else if (TYPE_REFFN_P (type))
6600 if (TREE_CODE (expr) == ADDR_EXPR)
6602 if (complain & tf_error)
6604 error ("%qE is not a valid template argument for type %qT "
6605 "because it is a pointer", expr, type);
6606 inform (input_location, "try using %qE instead",
6607 TREE_OPERAND (expr, 0));
6612 expr = convert_nontype_argument_function (type, expr, complain);
6613 if (!expr || expr == error_mark_node)
6616 expr = build_nop (type, build_address (expr));
6618 /* [temp.arg.nontype]/5, bullet 6
6620 For a non-type template-parameter of type pointer to member function,
6621 no conversions apply. If the template-argument represents a set of
6622 overloaded member functions, the matching member function is selected
6623 from the set (_over.over_). */
6624 else if (TYPE_PTRMEMFUNC_P (type))
6626 expr = instantiate_type (type, expr, tf_none);
6627 if (expr == error_mark_node)
6628 return error_mark_node;
6630 /* [temp.arg.nontype] bullet 1 says the pointer to member
6631 expression must be a pointer-to-member constant. */
6632 if (!check_valid_ptrmem_cst_expr (type, expr, complain))
6633 return error_mark_node;
6635 /* There is no way to disable standard conversions in
6636 resolve_address_of_overloaded_function (called by
6637 instantiate_type). It is possible that the call succeeded by
6638 converting &B::I to &D::I (where B is a base of D), so we need
6639 to reject this conversion here.
6641 Actually, even if there was a way to disable standard conversions,
6642 it would still be better to reject them here so that we can
6643 provide a superior diagnostic. */
6644 if (!same_type_p (TREE_TYPE (expr), type))
6646 if (complain & tf_error)
6648 error ("%qE is not a valid template argument for type %qT "
6649 "because it is of type %qT", expr, type,
6651 /* If we are just one standard conversion off, explain. */
6652 if (can_convert_standard (type, TREE_TYPE (expr), complain))
6653 inform (input_location,
6654 "standard conversions are not allowed in this context");
6659 /* [temp.arg.nontype]/5, bullet 7
6661 For a non-type template-parameter of type pointer to data member,
6662 qualification conversions (_conv.qual_) are applied. */
6663 else if (TYPE_PTRDATAMEM_P (type))
6665 /* [temp.arg.nontype] bullet 1 says the pointer to member
6666 expression must be a pointer-to-member constant. */
6667 if (!check_valid_ptrmem_cst_expr (type, expr, complain))
6668 return error_mark_node;
6670 expr = perform_qualification_conversions (type, expr);
6671 if (expr == error_mark_node)
6674 else if (NULLPTR_TYPE_P (type))
6676 if (expr != nullptr_node)
6678 if (complain & tf_error)
6679 error ("%qE is not a valid template argument for type %qT "
6680 "because it is of type %qT", expr, type, TREE_TYPE (expr));
6685 /* A template non-type parameter must be one of the above. */
6689 /* Sanity check: did we actually convert the argument to the
6691 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6692 (type, TREE_TYPE (expr)));
6693 return convert_from_reference (expr);
6696 /* Subroutine of coerce_template_template_parms, which returns 1 if
6697 PARM_PARM and ARG_PARM match using the rule for the template
6698 parameters of template template parameters. Both PARM and ARG are
6699 template parameters; the rest of the arguments are the same as for
6700 coerce_template_template_parms.
6703 coerce_template_template_parm (tree parm,
6705 tsubst_flags_t complain,
6709 if (arg == NULL_TREE || error_operand_p (arg)
6710 || parm == NULL_TREE || error_operand_p (parm))
6713 if (TREE_CODE (arg) != TREE_CODE (parm))
6716 switch (TREE_CODE (parm))
6719 /* We encounter instantiations of templates like
6720 template <template <template <class> class> class TT>
6723 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
6724 tree argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
6726 if (!coerce_template_template_parms
6727 (parmparm, argparm, complain, in_decl, outer_args))
6733 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (arg))
6734 && !TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
6735 /* Argument is a parameter pack but parameter is not. */
6740 /* The tsubst call is used to handle cases such as
6742 template <int> class C {};
6743 template <class T, template <T> class TT> class D {};
6746 i.e. the parameter list of TT depends on earlier parameters. */
6747 if (!uses_template_parms (TREE_TYPE (arg)))
6749 tree t = tsubst (TREE_TYPE (parm), outer_args, complain, in_decl);
6750 if (!uses_template_parms (t)
6751 && !same_type_p (t, TREE_TYPE (arg)))
6755 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (arg))
6756 && !TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
6757 /* Argument is a parameter pack but parameter is not. */
6770 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
6771 template template parameters. Both PARM_PARMS and ARG_PARMS are
6772 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
6775 Consider the example:
6776 template <class T> class A;
6777 template<template <class U> class TT> class B;
6779 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
6780 the parameters to A, and OUTER_ARGS contains A. */
6783 coerce_template_template_parms (tree parm_parms,
6785 tsubst_flags_t complain,
6789 int nparms, nargs, i;
6793 gcc_assert (TREE_CODE (parm_parms) == TREE_VEC);
6794 gcc_assert (TREE_CODE (arg_parms) == TREE_VEC);
6796 nparms = TREE_VEC_LENGTH (parm_parms);
6797 nargs = TREE_VEC_LENGTH (arg_parms);
6799 /* Determine whether we have a parameter pack at the end of the
6800 template template parameter's template parameter list. */
6801 if (TREE_VEC_ELT (parm_parms, nparms - 1) != error_mark_node)
6803 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, nparms - 1));
6805 if (error_operand_p (parm))
6808 switch (TREE_CODE (parm))
6812 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
6817 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
6827 && !(variadic_p && nargs >= nparms - 1))
6830 /* Check all of the template parameters except the parameter pack at
6831 the end (if any). */
6832 for (i = 0; i < nparms - variadic_p; ++i)
6834 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node
6835 || TREE_VEC_ELT (arg_parms, i) == error_mark_node)
6838 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
6839 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
6841 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
6849 /* Check each of the template parameters in the template
6850 argument against the template parameter pack at the end of
6851 the template template parameter. */
6852 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node)
6855 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
6857 for (; i < nargs; ++i)
6859 if (TREE_VEC_ELT (arg_parms, i) == error_mark_node)
6862 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
6864 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
6873 /* Verifies that the deduced template arguments (in TARGS) for the
6874 template template parameters (in TPARMS) represent valid bindings,
6875 by comparing the template parameter list of each template argument
6876 to the template parameter list of its corresponding template
6877 template parameter, in accordance with DR150. This
6878 routine can only be called after all template arguments have been
6879 deduced. It will return TRUE if all of the template template
6880 parameter bindings are okay, FALSE otherwise. */
6882 template_template_parm_bindings_ok_p (tree tparms, tree targs)
6884 int i, ntparms = TREE_VEC_LENGTH (tparms);
6887 /* We're dealing with template parms in this process. */
6888 ++processing_template_decl;
6890 targs = INNERMOST_TEMPLATE_ARGS (targs);
6892 for (i = 0; i < ntparms; ++i)
6894 tree tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
6895 tree targ = TREE_VEC_ELT (targs, i);
6897 if (TREE_CODE (tparm) == TEMPLATE_DECL && targ)
6899 tree packed_args = NULL_TREE;
6902 if (ARGUMENT_PACK_P (targ))
6904 /* Look inside the argument pack. */
6905 packed_args = ARGUMENT_PACK_ARGS (targ);
6906 len = TREE_VEC_LENGTH (packed_args);
6909 for (idx = 0; idx < len; ++idx)
6911 tree targ_parms = NULL_TREE;
6914 /* Extract the next argument from the argument
6916 targ = TREE_VEC_ELT (packed_args, idx);
6918 if (PACK_EXPANSION_P (targ))
6919 /* Look at the pattern of the pack expansion. */
6920 targ = PACK_EXPANSION_PATTERN (targ);
6922 /* Extract the template parameters from the template
6924 if (TREE_CODE (targ) == TEMPLATE_DECL)
6925 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (targ);
6926 else if (TREE_CODE (targ) == TEMPLATE_TEMPLATE_PARM)
6927 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (TYPE_NAME (targ));
6929 /* Verify that we can coerce the template template
6930 parameters from the template argument to the template
6931 parameter. This requires an exact match. */
6933 && !coerce_template_template_parms
6934 (DECL_INNERMOST_TEMPLATE_PARMS (tparm),
6949 --processing_template_decl;
6953 /* Since type attributes aren't mangled, we need to strip them from
6954 template type arguments. */
6957 canonicalize_type_argument (tree arg, tsubst_flags_t complain)
6959 if (!arg || arg == error_mark_node || arg == TYPE_CANONICAL (arg))
6961 bool removed_attributes = false;
6962 tree canon = strip_typedefs (arg, &removed_attributes);
6963 if (removed_attributes
6964 && (complain & tf_warning))
6965 warning (OPT_Wignored_attributes,
6966 "ignoring attributes on template argument %qT", arg);
6970 // A template declaration can be substituted for a constrained
6971 // template template parameter only when the argument is more
6972 // constrained than the parameter.
6974 is_compatible_template_arg (tree parm, tree arg)
6976 tree parm_cons = get_constraints (parm);
6978 /* For now, allow constrained template template arguments
6979 and unconstrained template template parameters. */
6980 if (parm_cons == NULL_TREE)
6983 tree arg_cons = get_constraints (arg);
6985 // If the template parameter is constrained, we need to rewrite its
6986 // constraints in terms of the ARG's template parameters. This ensures
6987 // that all of the template parameter types will have the same depth.
6989 // Note that this is only valid when coerce_template_template_parm is
6990 // true for the innermost template parameters of PARM and ARG. In other
6991 // words, because coercion is successful, this conversion will be valid.
6994 tree args = template_parms_to_args (DECL_TEMPLATE_PARMS (arg));
6995 parm_cons = tsubst_constraint_info (parm_cons,
6996 INNERMOST_TEMPLATE_ARGS (args),
6997 tf_none, NULL_TREE);
6998 if (parm_cons == error_mark_node)
7002 return subsumes (parm_cons, arg_cons);
7005 // Convert a placeholder argument into a binding to the original
7006 // parameter. The original parameter is saved as the TREE_TYPE of
7009 convert_wildcard_argument (tree parm, tree arg)
7011 TREE_TYPE (arg) = parm;
7015 /* Convert the indicated template ARG as necessary to match the
7016 indicated template PARM. Returns the converted ARG, or
7017 error_mark_node if the conversion was unsuccessful. Error and
7018 warning messages are issued under control of COMPLAIN. This
7019 conversion is for the Ith parameter in the parameter list. ARGS is
7020 the full set of template arguments deduced so far. */
7023 convert_template_argument (tree parm,
7026 tsubst_flags_t complain,
7032 int is_type, requires_type, is_tmpl_type, requires_tmpl_type;
7034 if (parm == error_mark_node)
7035 return error_mark_node;
7037 /* Trivially convert placeholders. */
7038 if (TREE_CODE (arg) == WILDCARD_DECL)
7039 return convert_wildcard_argument (parm, arg);
7041 if (TREE_CODE (arg) == TREE_LIST
7042 && TREE_CODE (TREE_VALUE (arg)) == OFFSET_REF)
7044 /* The template argument was the name of some
7045 member function. That's usually
7046 invalid, but static members are OK. In any
7047 case, grab the underlying fields/functions
7048 and issue an error later if required. */
7049 orig_arg = TREE_VALUE (arg);
7050 TREE_TYPE (arg) = unknown_type_node;
7055 requires_tmpl_type = TREE_CODE (parm) == TEMPLATE_DECL;
7056 requires_type = (TREE_CODE (parm) == TYPE_DECL
7057 || requires_tmpl_type);
7059 /* When determining whether an argument pack expansion is a template,
7060 look at the pattern. */
7061 if (TREE_CODE (arg) == TYPE_PACK_EXPANSION)
7062 arg = PACK_EXPANSION_PATTERN (arg);
7064 /* Deal with an injected-class-name used as a template template arg. */
7065 if (requires_tmpl_type && CLASS_TYPE_P (arg))
7067 tree t = maybe_get_template_decl_from_type_decl (TYPE_NAME (arg));
7068 if (TREE_CODE (t) == TEMPLATE_DECL)
7070 if (cxx_dialect >= cxx11)
7071 /* OK under DR 1004. */;
7072 else if (complain & tf_warning_or_error)
7073 pedwarn (input_location, OPT_Wpedantic, "injected-class-name %qD"
7074 " used as template template argument", TYPE_NAME (arg));
7075 else if (flag_pedantic_errors)
7083 ((TREE_CODE (arg) == TEMPLATE_DECL
7084 && TREE_CODE (DECL_TEMPLATE_RESULT (arg)) == TYPE_DECL)
7085 || (requires_tmpl_type && TREE_CODE (arg) == TYPE_ARGUMENT_PACK)
7086 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
7087 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE);
7090 && (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
7091 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE))
7092 arg = TYPE_STUB_DECL (arg);
7094 is_type = TYPE_P (arg) || is_tmpl_type;
7096 if (requires_type && ! is_type && TREE_CODE (arg) == SCOPE_REF
7097 && TREE_CODE (TREE_OPERAND (arg, 0)) == TEMPLATE_TYPE_PARM)
7099 if (TREE_CODE (TREE_OPERAND (arg, 1)) == BIT_NOT_EXPR)
7101 if (complain & tf_error)
7102 error ("invalid use of destructor %qE as a type", orig_arg);
7103 return error_mark_node;
7106 permerror (input_location,
7107 "to refer to a type member of a template parameter, "
7108 "use %<typename %E%>", orig_arg);
7110 orig_arg = make_typename_type (TREE_OPERAND (arg, 0),
7111 TREE_OPERAND (arg, 1),
7117 if (is_type != requires_type)
7121 if (complain & tf_error)
7123 error ("type/value mismatch at argument %d in template "
7124 "parameter list for %qD",
7127 inform (input_location,
7128 " expected a constant of type %qT, got %qT",
7130 (DECL_P (arg) ? DECL_NAME (arg) : orig_arg));
7131 else if (requires_tmpl_type)
7132 inform (input_location,
7133 " expected a class template, got %qE", orig_arg);
7135 inform (input_location,
7136 " expected a type, got %qE", orig_arg);
7139 return error_mark_node;
7141 if (is_tmpl_type ^ requires_tmpl_type)
7143 if (in_decl && (complain & tf_error))
7145 error ("type/value mismatch at argument %d in template "
7146 "parameter list for %qD",
7149 inform (input_location,
7150 " expected a type, got %qT", DECL_NAME (arg));
7152 inform (input_location,
7153 " expected a class template, got %qT", orig_arg);
7155 return error_mark_node;
7160 if (requires_tmpl_type)
7162 if (template_parameter_pack_p (parm) && ARGUMENT_PACK_P (orig_arg))
7164 else if (TREE_CODE (TREE_TYPE (arg)) == UNBOUND_CLASS_TEMPLATE)
7165 /* The number of argument required is not known yet.
7166 Just accept it for now. */
7167 val = TREE_TYPE (arg);
7170 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
7173 /* Strip alias templates that are equivalent to another
7175 arg = get_underlying_template (arg);
7176 argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
7178 if (coerce_template_template_parms (parmparm, argparm,
7184 /* TEMPLATE_TEMPLATE_PARM node is preferred over
7186 if (val != error_mark_node)
7188 if (DECL_TEMPLATE_TEMPLATE_PARM_P (val))
7189 val = TREE_TYPE (val);
7190 if (TREE_CODE (orig_arg) == TYPE_PACK_EXPANSION)
7191 val = make_pack_expansion (val);
7196 if (in_decl && (complain & tf_error))
7198 error ("type/value mismatch at argument %d in "
7199 "template parameter list for %qD",
7201 inform (input_location,
7202 " expected a template of type %qD, got %qT",
7206 val = error_mark_node;
7209 // Check that the constraints are compatible before allowing the
7211 if (val != error_mark_node)
7212 if (!is_compatible_template_arg (parm, arg))
7214 if (in_decl && (complain & tf_error))
7216 error ("constraint mismatch at argument %d in "
7217 "template parameter list for %qD",
7219 inform (input_location, " expected %qD but got %qD",
7222 val = error_mark_node;
7228 /* We only form one instance of each template specialization.
7229 Therefore, if we use a non-canonical variant (i.e., a
7230 typedef), any future messages referring to the type will use
7231 the typedef, which is confusing if those future uses do not
7232 themselves also use the typedef. */
7234 val = canonicalize_type_argument (val, complain);
7238 tree t = tsubst (TREE_TYPE (parm), args, complain, in_decl);
7240 if (invalid_nontype_parm_type_p (t, complain))
7241 return error_mark_node;
7243 if (template_parameter_pack_p (parm) && ARGUMENT_PACK_P (orig_arg))
7245 if (same_type_p (t, TREE_TYPE (orig_arg)))
7249 /* Not sure if this is reachable, but it doesn't hurt
7251 error ("type mismatch in nontype parameter pack");
7252 val = error_mark_node;
7255 else if (!dependent_template_arg_p (orig_arg)
7256 && !uses_template_parms (t))
7257 /* We used to call digest_init here. However, digest_init
7258 will report errors, which we don't want when complain
7259 is zero. More importantly, digest_init will try too
7260 hard to convert things: for example, `0' should not be
7261 converted to pointer type at this point according to
7262 the standard. Accepting this is not merely an
7263 extension, since deciding whether or not these
7264 conversions can occur is part of determining which
7265 function template to call, or whether a given explicit
7266 argument specification is valid. */
7267 val = convert_nontype_argument (t, orig_arg, complain);
7270 bool removed_attr = false;
7271 val = strip_typedefs_expr (orig_arg, &removed_attr);
7274 if (val == NULL_TREE)
7275 val = error_mark_node;
7276 else if (val == error_mark_node && (complain & tf_error))
7277 error ("could not convert template argument %qE to %qT", orig_arg, t);
7279 if (INDIRECT_REF_P (val))
7281 /* Reject template arguments that are references to built-in
7282 functions with no library fallbacks. */
7283 const_tree inner = TREE_OPERAND (val, 0);
7284 if (TREE_CODE (TREE_TYPE (inner)) == REFERENCE_TYPE
7285 && TREE_CODE (TREE_TYPE (TREE_TYPE (inner))) == FUNCTION_TYPE
7286 && TREE_CODE (TREE_TYPE (inner)) == REFERENCE_TYPE
7287 && 0 < TREE_OPERAND_LENGTH (inner)
7288 && reject_gcc_builtin (TREE_OPERAND (inner, 0)))
7289 return error_mark_node;
7292 if (TREE_CODE (val) == SCOPE_REF)
7294 /* Strip typedefs from the SCOPE_REF. */
7295 tree type = canonicalize_type_argument (TREE_TYPE (val), complain);
7296 tree scope = canonicalize_type_argument (TREE_OPERAND (val, 0),
7298 val = build_qualified_name (type, scope, TREE_OPERAND (val, 1),
7299 QUALIFIED_NAME_IS_TEMPLATE (val));
7306 /* Coerces the remaining template arguments in INNER_ARGS (from
7307 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
7308 Returns the coerced argument pack. PARM_IDX is the position of this
7309 parameter in the template parameter list. ARGS is the original
7310 template argument list. */
7312 coerce_template_parameter_pack (tree parms,
7320 tsubst_flags_t complain)
7322 tree parm = TREE_VEC_ELT (parms, parm_idx);
7323 int nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
7326 tree packed_parms = NULL_TREE;
7328 if (arg_idx > nargs)
7331 if (tree packs = fixed_parameter_pack_p (TREE_VALUE (parm)))
7333 /* When the template parameter is a non-type template parameter pack
7334 or template template parameter pack whose type or template
7335 parameters use parameter packs, we know exactly how many arguments
7336 we are looking for. Build a vector of the instantiated decls for
7337 these template parameters in PACKED_PARMS. */
7338 /* We can't use make_pack_expansion here because it would interpret a
7339 _DECL as a use rather than a declaration. */
7340 tree decl = TREE_VALUE (parm);
7341 tree exp = cxx_make_type (TYPE_PACK_EXPANSION);
7342 SET_PACK_EXPANSION_PATTERN (exp, decl);
7343 PACK_EXPANSION_PARAMETER_PACKS (exp) = packs;
7344 SET_TYPE_STRUCTURAL_EQUALITY (exp);
7346 TREE_VEC_LENGTH (args)--;
7347 packed_parms = tsubst_pack_expansion (exp, args, complain, decl);
7348 TREE_VEC_LENGTH (args)++;
7350 if (packed_parms == error_mark_node)
7351 return error_mark_node;
7353 /* If we're doing a partial instantiation of a member template,
7354 verify that all of the types used for the non-type
7355 template parameter pack are, in fact, valid for non-type
7356 template parameters. */
7358 && PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx)))
7360 int j, len = TREE_VEC_LENGTH (packed_parms);
7361 for (j = 0; j < len; ++j)
7363 tree t = TREE_TYPE (TREE_VEC_ELT (packed_parms, j));
7364 if (invalid_nontype_parm_type_p (t, complain))
7365 return error_mark_node;
7367 /* We don't know how many args we have yet, just
7368 use the unconverted ones for now. */
7372 packed_args = make_tree_vec (TREE_VEC_LENGTH (packed_parms));
7374 /* Check if we have a placeholder pack, which indicates we're
7375 in the context of a introduction list. In that case we want
7376 to match this pack to the single placeholder. */
7377 else if (arg_idx < nargs
7378 && TREE_CODE (TREE_VEC_ELT (inner_args, arg_idx)) == WILDCARD_DECL
7379 && WILDCARD_PACK_P (TREE_VEC_ELT (inner_args, arg_idx)))
7381 nargs = arg_idx + 1;
7382 packed_args = make_tree_vec (1);
7385 packed_args = make_tree_vec (nargs - arg_idx);
7387 /* Convert the remaining arguments, which will be a part of the
7388 parameter pack "parm". */
7389 int first_pack_arg = arg_idx;
7390 for (; arg_idx < nargs; ++arg_idx)
7392 tree arg = TREE_VEC_ELT (inner_args, arg_idx);
7393 tree actual_parm = TREE_VALUE (parm);
7394 int pack_idx = arg_idx - first_pack_arg;
7398 /* Once we've packed as many args as we have types, stop. */
7399 if (pack_idx >= TREE_VEC_LENGTH (packed_parms))
7401 else if (PACK_EXPANSION_P (arg))
7402 /* We don't know how many args we have yet, just
7403 use the unconverted ones for now. */
7406 actual_parm = TREE_VEC_ELT (packed_parms, pack_idx);
7409 if (arg == error_mark_node)
7411 if (complain & tf_error)
7412 error ("template argument %d is invalid", arg_idx + 1);
7415 arg = convert_template_argument (actual_parm,
7416 arg, new_args, complain, parm_idx,
7418 if (arg == error_mark_node)
7420 TREE_VEC_ELT (packed_args, pack_idx) = arg;
7423 if (arg_idx - first_pack_arg < TREE_VEC_LENGTH (packed_args)
7424 && TREE_VEC_LENGTH (packed_args) > 0)
7426 if (complain & tf_error)
7427 error ("wrong number of template arguments (%d, should be %d)",
7428 arg_idx - first_pack_arg, TREE_VEC_LENGTH (packed_args));
7429 return error_mark_node;
7432 if (TREE_CODE (TREE_VALUE (parm)) == TYPE_DECL
7433 || TREE_CODE (TREE_VALUE (parm)) == TEMPLATE_DECL)
7434 argument_pack = cxx_make_type (TYPE_ARGUMENT_PACK);
7437 argument_pack = make_node (NONTYPE_ARGUMENT_PACK);
7438 TREE_TYPE (argument_pack)
7439 = tsubst (TREE_TYPE (TREE_VALUE (parm)), new_args, complain, in_decl);
7440 TREE_CONSTANT (argument_pack) = 1;
7443 SET_ARGUMENT_PACK_ARGS (argument_pack, packed_args);
7445 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (packed_args,
7446 TREE_VEC_LENGTH (packed_args));
7447 return argument_pack;
7450 /* Returns the number of pack expansions in the template argument vector
7454 pack_expansion_args_count (tree args)
7459 for (i = 0; i < TREE_VEC_LENGTH (args); ++i)
7461 tree elt = TREE_VEC_ELT (args, i);
7462 if (elt && PACK_EXPANSION_P (elt))
7468 /* Convert all template arguments to their appropriate types, and
7469 return a vector containing the innermost resulting template
7470 arguments. If any error occurs, return error_mark_node. Error and
7471 warning messages are issued under control of COMPLAIN.
7473 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
7474 for arguments not specified in ARGS. Otherwise, if
7475 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
7476 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
7477 USE_DEFAULT_ARGS is false, then all arguments must be specified in
7481 coerce_template_parms (tree parms,
7484 tsubst_flags_t complain,
7485 bool require_all_args,
7486 bool use_default_args)
7488 int nparms, nargs, parm_idx, arg_idx, lost = 0;
7489 tree orig_inner_args;
7492 tree new_inner_args;
7493 int saved_unevaluated_operand;
7494 int saved_inhibit_evaluation_warnings;
7496 /* When used as a boolean value, indicates whether this is a
7497 variadic template parameter list. Since it's an int, we can also
7498 subtract it from nparms to get the number of non-variadic
7501 int variadic_args_p = 0;
7502 int post_variadic_parms = 0;
7504 /* Likewise for parameters with default arguments. */
7507 if (args == error_mark_node)
7508 return error_mark_node;
7510 nparms = TREE_VEC_LENGTH (parms);
7512 /* Determine if there are any parameter packs or default arguments. */
7513 for (parm_idx = 0; parm_idx < nparms; ++parm_idx)
7515 tree parm = TREE_VEC_ELT (parms, parm_idx);
7517 ++post_variadic_parms;
7518 if (template_parameter_pack_p (TREE_VALUE (parm)))
7520 if (TREE_PURPOSE (parm))
7524 inner_args = orig_inner_args = INNERMOST_TEMPLATE_ARGS (args);
7525 /* If there are no parameters that follow a parameter pack, we need to
7526 expand any argument packs so that we can deduce a parameter pack from
7527 some non-packed args followed by an argument pack, as in variadic85.C.
7528 If there are such parameters, we need to leave argument packs intact
7529 so the arguments are assigned properly. This can happen when dealing
7530 with a nested class inside a partial specialization of a class
7531 template, as in variadic92.C, or when deducing a template parameter pack
7532 from a sub-declarator, as in variadic114.C. */
7533 if (!post_variadic_parms)
7534 inner_args = expand_template_argument_pack (inner_args);
7536 /* Count any pack expansion args. */
7537 variadic_args_p = pack_expansion_args_count (inner_args);
7539 nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
7540 if ((nargs > nparms && !variadic_p)
7541 || (nargs < nparms - variadic_p
7544 && (!use_default_args
7545 || (TREE_VEC_ELT (parms, nargs) != error_mark_node
7546 && !TREE_PURPOSE (TREE_VEC_ELT (parms, nargs))))))
7548 if (complain & tf_error)
7550 if (variadic_p || default_p)
7552 nparms -= variadic_p + default_p;
7553 error ("wrong number of template arguments "
7554 "(%d, should be at least %d)", nargs, nparms);
7557 error ("wrong number of template arguments "
7558 "(%d, should be %d)", nargs, nparms);
7561 inform (DECL_SOURCE_LOCATION (in_decl),
7562 "provided for %qD", in_decl);
7565 return error_mark_node;
7567 /* We can't pass a pack expansion to a non-pack parameter of an alias
7568 template (DR 1430). */
7570 && (DECL_ALIAS_TEMPLATE_P (in_decl)
7571 || concept_template_p (in_decl))
7573 && nargs - variadic_args_p < nparms - variadic_p)
7575 if (complain & tf_error)
7577 for (int i = 0; i < TREE_VEC_LENGTH (inner_args); ++i)
7579 tree arg = TREE_VEC_ELT (inner_args, i);
7580 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
7582 if (PACK_EXPANSION_P (arg)
7583 && !template_parameter_pack_p (parm))
7585 if (DECL_ALIAS_TEMPLATE_P (in_decl))
7586 error_at (location_of (arg),
7587 "pack expansion argument for non-pack parameter "
7588 "%qD of alias template %qD", parm, in_decl);
7590 error_at (location_of (arg),
7591 "pack expansion argument for non-pack parameter "
7592 "%qD of concept %qD", parm, in_decl);
7593 inform (DECL_SOURCE_LOCATION (parm), "declared here");
7600 return error_mark_node;
7603 /* We need to evaluate the template arguments, even though this
7604 template-id may be nested within a "sizeof". */
7605 saved_unevaluated_operand = cp_unevaluated_operand;
7606 cp_unevaluated_operand = 0;
7607 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
7608 c_inhibit_evaluation_warnings = 0;
7609 new_inner_args = make_tree_vec (nparms);
7610 new_args = add_outermost_template_args (args, new_inner_args);
7611 int pack_adjust = 0;
7612 for (parm_idx = 0, arg_idx = 0; parm_idx < nparms; parm_idx++, arg_idx++)
7617 /* Get the Ith template parameter. */
7618 parm = TREE_VEC_ELT (parms, parm_idx);
7620 if (parm == error_mark_node)
7622 TREE_VEC_ELT (new_inner_args, arg_idx) = error_mark_node;
7626 /* Calculate the next argument. */
7627 if (arg_idx < nargs)
7628 arg = TREE_VEC_ELT (inner_args, arg_idx);
7632 if (template_parameter_pack_p (TREE_VALUE (parm))
7633 && !(arg && ARGUMENT_PACK_P (arg)))
7635 /* Some arguments will be placed in the
7636 template parameter pack PARM. */
7637 arg = coerce_template_parameter_pack (parms, parm_idx, args,
7638 inner_args, arg_idx,
7642 if (arg == NULL_TREE)
7644 /* We don't know how many args we have yet, just use the
7645 unconverted (and still packed) ones for now. */
7646 new_inner_args = orig_inner_args;
7651 TREE_VEC_ELT (new_inner_args, parm_idx) = arg;
7653 /* Store this argument. */
7654 if (arg == error_mark_node)
7657 /* We are done with all of the arguments. */
7662 pack_adjust = TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg)) - 1;
7663 arg_idx += pack_adjust;
7670 if (PACK_EXPANSION_P (arg))
7672 /* "If every valid specialization of a variadic template
7673 requires an empty template parameter pack, the template is
7674 ill-formed, no diagnostic required." So check that the
7675 pattern works with this parameter. */
7676 tree pattern = PACK_EXPANSION_PATTERN (arg);
7677 tree conv = convert_template_argument (TREE_VALUE (parm),
7681 if (conv == error_mark_node)
7683 inform (input_location, "so any instantiation with a "
7684 "non-empty parameter pack would be ill-formed");
7687 else if (TYPE_P (conv) && !TYPE_P (pattern))
7688 /* Recover from missing typename. */
7689 TREE_VEC_ELT (inner_args, arg_idx)
7690 = make_pack_expansion (conv);
7692 /* We don't know how many args we have yet, just
7693 use the unconverted ones for now. */
7694 new_inner_args = inner_args;
7699 else if (require_all_args)
7701 /* There must be a default arg in this case. */
7702 arg = tsubst_template_arg (TREE_PURPOSE (parm), new_args,
7704 /* The position of the first default template argument,
7705 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
7707 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args))
7708 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args,
7709 arg_idx - pack_adjust);
7714 if (arg == error_mark_node)
7716 if (complain & tf_error)
7717 error ("template argument %d is invalid", arg_idx + 1);
7720 /* This only occurs if there was an error in the template
7721 parameter list itself (which we would already have
7722 reported) that we are trying to recover from, e.g., a class
7723 template with a parameter list such as
7724 template<typename..., typename>. */
7727 arg = convert_template_argument (TREE_VALUE (parm),
7728 arg, new_args, complain,
7731 if (arg == error_mark_node)
7733 TREE_VEC_ELT (new_inner_args, arg_idx - pack_adjust) = arg;
7735 cp_unevaluated_operand = saved_unevaluated_operand;
7736 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
7738 if (variadic_p && arg_idx < nargs)
7740 if (complain & tf_error)
7742 error ("wrong number of template arguments "
7743 "(%d, should be %d)", nargs, arg_idx);
7745 error ("provided for %q+D", in_decl);
7747 return error_mark_node;
7751 return error_mark_node;
7753 if (CHECKING_P && !NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args))
7754 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args,
7755 TREE_VEC_LENGTH (new_inner_args));
7757 return new_inner_args;
7760 /* Convert all template arguments to their appropriate types, and
7761 return a vector containing the innermost resulting template
7762 arguments. If any error occurs, return error_mark_node. Error and
7763 warning messages are not issued.
7765 Note that no function argument deduction is performed, and default
7766 arguments are used to fill in unspecified arguments. */
7768 coerce_template_parms (tree parms, tree args, tree in_decl)
7770 return coerce_template_parms (parms, args, in_decl, tf_none, true, true);
7773 /* Convert all template arguments to their appropriate type, and
7774 instantiate default arguments as needed. This returns a vector
7775 containing the innermost resulting template arguments, or
7776 error_mark_node if unsuccessful. */
7778 coerce_template_parms (tree parms, tree args, tree in_decl,
7779 tsubst_flags_t complain)
7781 return coerce_template_parms (parms, args, in_decl, complain, true, true);
7784 /* Like coerce_template_parms. If PARMS represents all template
7785 parameters levels, this function returns a vector of vectors
7786 representing all the resulting argument levels. Note that in this
7787 case, only the innermost arguments are coerced because the
7788 outermost ones are supposed to have been coerced already.
7790 Otherwise, if PARMS represents only (the innermost) vector of
7791 parameters, this function returns a vector containing just the
7792 innermost resulting arguments. */
7795 coerce_innermost_template_parms (tree parms,
7798 tsubst_flags_t complain,
7799 bool require_all_args,
7800 bool use_default_args)
7802 int parms_depth = TMPL_PARMS_DEPTH (parms);
7803 int args_depth = TMPL_ARGS_DEPTH (args);
7806 if (parms_depth > 1)
7808 coerced_args = make_tree_vec (parms_depth);
7812 for (level = parms, cur_depth = parms_depth;
7813 parms_depth > 0 && level != NULL_TREE;
7814 level = TREE_CHAIN (level), --cur_depth)
7817 if (cur_depth == args_depth)
7818 l = coerce_template_parms (TREE_VALUE (level),
7819 args, in_decl, complain,
7823 l = TMPL_ARGS_LEVEL (args, cur_depth);
7825 if (l == error_mark_node)
7826 return error_mark_node;
7828 SET_TMPL_ARGS_LEVEL (coerced_args, cur_depth, l);
7832 coerced_args = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parms),
7833 args, in_decl, complain,
7836 return coerced_args;
7839 /* Returns 1 if template args OT and NT are equivalent. */
7842 template_args_equal (tree ot, tree nt)
7846 if (nt == NULL_TREE || ot == NULL_TREE)
7849 if (TREE_CODE (nt) == TREE_VEC)
7850 /* For member templates */
7851 return TREE_CODE (ot) == TREE_VEC && comp_template_args (ot, nt);
7852 else if (PACK_EXPANSION_P (ot))
7853 return (PACK_EXPANSION_P (nt)
7854 && template_args_equal (PACK_EXPANSION_PATTERN (ot),
7855 PACK_EXPANSION_PATTERN (nt))
7856 && template_args_equal (PACK_EXPANSION_EXTRA_ARGS (ot),
7857 PACK_EXPANSION_EXTRA_ARGS (nt)));
7858 else if (ARGUMENT_PACK_P (ot))
7863 if (!ARGUMENT_PACK_P (nt))
7866 opack = ARGUMENT_PACK_ARGS (ot);
7867 npack = ARGUMENT_PACK_ARGS (nt);
7868 len = TREE_VEC_LENGTH (opack);
7869 if (TREE_VEC_LENGTH (npack) != len)
7871 for (i = 0; i < len; ++i)
7872 if (!template_args_equal (TREE_VEC_ELT (opack, i),
7873 TREE_VEC_ELT (npack, i)))
7877 else if (ot && TREE_CODE (ot) == ARGUMENT_PACK_SELECT)
7879 /* We get here probably because we are in the middle of substituting
7880 into the pattern of a pack expansion. In that case the
7881 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
7882 interested in. So we want to use the initial pack argument for
7884 ot = ARGUMENT_PACK_SELECT_FROM_PACK (ot);
7885 if (nt && TREE_CODE (nt) == ARGUMENT_PACK_SELECT)
7886 nt = ARGUMENT_PACK_SELECT_FROM_PACK (nt);
7887 return template_args_equal (ot, nt);
7889 else if (TYPE_P (nt))
7893 /* Don't treat an alias template specialization with dependent
7894 arguments as equivalent to its underlying type when used as a
7895 template argument; we need them to be distinct so that we
7896 substitute into the specialization arguments at instantiation
7897 time. And aliases can't be equivalent without being ==, so
7898 we don't need to look any deeper. */
7899 if (TYPE_ALIAS_P (nt) || TYPE_ALIAS_P (ot))
7902 return same_type_p (ot, nt);
7904 else if (TREE_CODE (ot) == TREE_VEC || TYPE_P (ot))
7908 /* Try to treat a template non-type argument that has been converted
7909 to the parameter type as equivalent to one that hasn't yet. */
7910 for (enum tree_code code1 = TREE_CODE (ot);
7911 CONVERT_EXPR_CODE_P (code1)
7912 || code1 == NON_LVALUE_EXPR;
7913 code1 = TREE_CODE (ot))
7914 ot = TREE_OPERAND (ot, 0);
7915 for (enum tree_code code2 = TREE_CODE (nt);
7916 CONVERT_EXPR_CODE_P (code2)
7917 || code2 == NON_LVALUE_EXPR;
7918 code2 = TREE_CODE (nt))
7919 nt = TREE_OPERAND (nt, 0);
7921 return cp_tree_equal (ot, nt);
7925 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
7926 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
7927 NEWARG_PTR with the offending arguments if they are non-NULL. */
7930 comp_template_args (tree oldargs, tree newargs,
7931 tree *oldarg_ptr, tree *newarg_ptr)
7935 if (oldargs == newargs)
7938 if (!oldargs || !newargs)
7941 if (TREE_VEC_LENGTH (oldargs) != TREE_VEC_LENGTH (newargs))
7944 for (i = 0; i < TREE_VEC_LENGTH (oldargs); ++i)
7946 tree nt = TREE_VEC_ELT (newargs, i);
7947 tree ot = TREE_VEC_ELT (oldargs, i);
7949 if (! template_args_equal (ot, nt))
7951 if (oldarg_ptr != NULL)
7953 if (newarg_ptr != NULL)
7962 add_pending_template (tree d)
7964 tree ti = (TYPE_P (d)
7965 ? CLASSTYPE_TEMPLATE_INFO (d)
7966 : DECL_TEMPLATE_INFO (d));
7967 struct pending_template *pt;
7970 if (TI_PENDING_TEMPLATE_FLAG (ti))
7973 /* We are called both from instantiate_decl, where we've already had a
7974 tinst_level pushed, and instantiate_template, where we haven't.
7976 level = !current_tinst_level || current_tinst_level->decl != d;
7979 push_tinst_level (d);
7981 pt = ggc_alloc<pending_template> ();
7983 pt->tinst = current_tinst_level;
7984 if (last_pending_template)
7985 last_pending_template->next = pt;
7987 pending_templates = pt;
7989 last_pending_template = pt;
7991 TI_PENDING_TEMPLATE_FLAG (ti) = 1;
7998 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
7999 ARGLIST. Valid choices for FNS are given in the cp-tree.def
8000 documentation for TEMPLATE_ID_EXPR. */
8003 lookup_template_function (tree fns, tree arglist)
8007 if (fns == error_mark_node || arglist == error_mark_node)
8008 return error_mark_node;
8010 gcc_assert (!arglist || TREE_CODE (arglist) == TREE_VEC);
8012 if (!is_overloaded_fn (fns) && !identifier_p (fns))
8014 error ("%q#D is not a function template", fns);
8015 return error_mark_node;
8018 if (BASELINK_P (fns))
8020 BASELINK_FUNCTIONS (fns) = build2 (TEMPLATE_ID_EXPR,
8022 BASELINK_FUNCTIONS (fns),
8027 type = TREE_TYPE (fns);
8028 if (TREE_CODE (fns) == OVERLOAD || !type)
8029 type = unknown_type_node;
8031 return build2 (TEMPLATE_ID_EXPR, type, fns, arglist);
8034 /* Within the scope of a template class S<T>, the name S gets bound
8035 (in build_self_reference) to a TYPE_DECL for the class, not a
8036 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
8037 or one of its enclosing classes, and that type is a template,
8038 return the associated TEMPLATE_DECL. Otherwise, the original
8041 Also handle the case when DECL is a TREE_LIST of ambiguous
8042 injected-class-names from different bases. */
8045 maybe_get_template_decl_from_type_decl (tree decl)
8047 if (decl == NULL_TREE)
8050 /* DR 176: A lookup that finds an injected-class-name (10.2
8051 [class.member.lookup]) can result in an ambiguity in certain cases
8052 (for example, if it is found in more than one base class). If all of
8053 the injected-class-names that are found refer to specializations of
8054 the same class template, and if the name is followed by a
8055 template-argument-list, the reference refers to the class template
8056 itself and not a specialization thereof, and is not ambiguous. */
8057 if (TREE_CODE (decl) == TREE_LIST)
8059 tree t, tmpl = NULL_TREE;
8060 for (t = decl; t; t = TREE_CHAIN (t))
8062 tree elt = maybe_get_template_decl_from_type_decl (TREE_VALUE (t));
8065 else if (tmpl != elt)
8068 if (tmpl && t == NULL_TREE)
8074 return (decl != NULL_TREE
8075 && DECL_SELF_REFERENCE_P (decl)
8076 && CLASSTYPE_TEMPLATE_INFO (TREE_TYPE (decl)))
8077 ? CLASSTYPE_TI_TEMPLATE (TREE_TYPE (decl)) : decl;
8080 /* Given an IDENTIFIER_NODE (or type TEMPLATE_DECL) and a chain of
8081 parameters, find the desired type.
8083 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
8085 IN_DECL, if non-NULL, is the template declaration we are trying to
8088 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
8089 the class we are looking up.
8091 Issue error and warning messages under control of COMPLAIN.
8093 If the template class is really a local class in a template
8094 function, then the FUNCTION_CONTEXT is the function in which it is
8097 ??? Note that this function is currently called *twice* for each
8098 template-id: the first time from the parser, while creating the
8099 incomplete type (finish_template_type), and the second type during the
8100 real instantiation (instantiate_template_class). This is surely something
8101 that we want to avoid. It also causes some problems with argument
8102 coercion (see convert_nontype_argument for more information on this). */
8105 lookup_template_class_1 (tree d1, tree arglist, tree in_decl, tree context,
8106 int entering_scope, tsubst_flags_t complain)
8108 tree templ = NULL_TREE, parmlist;
8115 if (identifier_p (d1))
8117 tree value = innermost_non_namespace_value (d1);
8118 if (value && DECL_TEMPLATE_TEMPLATE_PARM_P (value))
8123 push_decl_namespace (context);
8124 templ = lookup_name (d1);
8125 templ = maybe_get_template_decl_from_type_decl (templ);
8127 pop_decl_namespace ();
8130 context = DECL_CONTEXT (templ);
8132 else if (TREE_CODE (d1) == TYPE_DECL && MAYBE_CLASS_TYPE_P (TREE_TYPE (d1)))
8134 tree type = TREE_TYPE (d1);
8136 /* If we are declaring a constructor, say A<T>::A<T>, we will get
8137 an implicit typename for the second A. Deal with it. */
8138 if (TREE_CODE (type) == TYPENAME_TYPE && TREE_TYPE (type))
8139 type = TREE_TYPE (type);
8141 if (CLASSTYPE_TEMPLATE_INFO (type))
8143 templ = CLASSTYPE_TI_TEMPLATE (type);
8144 d1 = DECL_NAME (templ);
8147 else if (TREE_CODE (d1) == ENUMERAL_TYPE
8148 || (TYPE_P (d1) && MAYBE_CLASS_TYPE_P (d1)))
8150 templ = TYPE_TI_TEMPLATE (d1);
8151 d1 = DECL_NAME (templ);
8153 else if (DECL_TYPE_TEMPLATE_P (d1))
8156 d1 = DECL_NAME (templ);
8157 context = DECL_CONTEXT (templ);
8159 else if (DECL_TEMPLATE_TEMPLATE_PARM_P (d1))
8162 d1 = DECL_NAME (templ);
8165 /* Issue an error message if we didn't find a template. */
8168 if (complain & tf_error)
8169 error ("%qT is not a template", d1);
8170 return error_mark_node;
8173 if (TREE_CODE (templ) != TEMPLATE_DECL
8174 /* Make sure it's a user visible template, if it was named by
8176 || ((complain & tf_user) && !DECL_TEMPLATE_PARM_P (templ)
8177 && !PRIMARY_TEMPLATE_P (templ)))
8179 if (complain & tf_error)
8181 error ("non-template type %qT used as a template", d1);
8183 error ("for template declaration %q+D", in_decl);
8185 return error_mark_node;
8188 complain &= ~tf_user;
8190 /* An alias that just changes the name of a template is equivalent to the
8191 other template, so if any of the arguments are pack expansions, strip
8192 the alias to avoid problems with a pack expansion passed to a non-pack
8193 alias template parameter (DR 1430). */
8194 if (pack_expansion_args_count (INNERMOST_TEMPLATE_ARGS (arglist)))
8195 templ = get_underlying_template (templ);
8197 if (DECL_TEMPLATE_TEMPLATE_PARM_P (templ))
8199 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
8200 template arguments */
8206 parmlist = DECL_INNERMOST_TEMPLATE_PARMS (templ);
8208 /* Consider an example where a template template parameter declared as
8210 template <class T, class U = std::allocator<T> > class TT
8212 The template parameter level of T and U are one level larger than
8213 of TT. To proper process the default argument of U, say when an
8214 instantiation `TT<int>' is seen, we need to build the full
8215 arguments containing {int} as the innermost level. Outer levels,
8216 available when not appearing as default template argument, can be
8217 obtained from the arguments of the enclosing template.
8219 Suppose that TT is later substituted with std::vector. The above
8220 instantiation is `TT<int, std::allocator<T> >' with TT at
8221 level 1, and T at level 2, while the template arguments at level 1
8222 becomes {std::vector} and the inner level 2 is {int}. */
8224 outer = DECL_CONTEXT (templ);
8226 outer = TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (outer)));
8227 else if (current_template_parms)
8229 /* This is an argument of the current template, so we haven't set
8230 DECL_CONTEXT yet. */
8231 tree relevant_template_parms;
8233 /* Parameter levels that are greater than the level of the given
8234 template template parm are irrelevant. */
8235 relevant_template_parms = current_template_parms;
8236 while (TMPL_PARMS_DEPTH (relevant_template_parms)
8237 != TEMPLATE_TYPE_LEVEL (TREE_TYPE (templ)))
8238 relevant_template_parms = TREE_CHAIN (relevant_template_parms);
8240 outer = template_parms_to_args (relevant_template_parms);
8244 arglist = add_to_template_args (outer, arglist);
8246 arglist2 = coerce_template_parms (parmlist, arglist, templ,
8248 /*require_all_args=*/true,
8249 /*use_default_args=*/true);
8250 if (arglist2 == error_mark_node
8251 || (!uses_template_parms (arglist2)
8252 && check_instantiated_args (templ, arglist2, complain)))
8253 return error_mark_node;
8255 parm = bind_template_template_parm (TREE_TYPE (templ), arglist2);
8260 tree template_type = TREE_TYPE (templ);
8263 tree found = NULL_TREE;
8266 int is_dependent_type;
8267 int use_partial_inst_tmpl = false;
8269 if (template_type == error_mark_node)
8270 /* An error occurred while building the template TEMPL, and a
8271 diagnostic has most certainly been emitted for that
8272 already. Let's propagate that error. */
8273 return error_mark_node;
8275 gen_tmpl = most_general_template (templ);
8276 parmlist = DECL_TEMPLATE_PARMS (gen_tmpl);
8277 parm_depth = TMPL_PARMS_DEPTH (parmlist);
8278 arg_depth = TMPL_ARGS_DEPTH (arglist);
8280 if (arg_depth == 1 && parm_depth > 1)
8282 /* We've been given an incomplete set of template arguments.
8285 template <class T> struct S1 {
8286 template <class U> struct S2 {};
8287 template <class U> struct S2<U*> {};
8290 we will be called with an ARGLIST of `U*', but the
8291 TEMPLATE will be `template <class T> template
8292 <class U> struct S1<T>::S2'. We must fill in the missing
8295 = add_outermost_template_args (TYPE_TI_ARGS (TREE_TYPE (templ)),
8297 arg_depth = TMPL_ARGS_DEPTH (arglist);
8300 /* Now we should have enough arguments. */
8301 gcc_assert (parm_depth == arg_depth);
8303 /* From here on, we're only interested in the most general
8306 /* Calculate the BOUND_ARGS. These will be the args that are
8307 actually tsubst'd into the definition to create the
8309 arglist = coerce_innermost_template_parms (parmlist, arglist, gen_tmpl,
8311 /*require_all_args=*/true,
8312 /*use_default_args=*/true);
8314 if (arglist == error_mark_node)
8315 /* We were unable to bind the arguments. */
8316 return error_mark_node;
8318 /* In the scope of a template class, explicit references to the
8319 template class refer to the type of the template, not any
8320 instantiation of it. For example, in:
8322 template <class T> class C { void f(C<T>); }
8324 the `C<T>' is just the same as `C'. Outside of the
8325 class, however, such a reference is an instantiation. */
8327 || !PRIMARY_TEMPLATE_P (gen_tmpl)
8328 || currently_open_class (template_type))
8329 /* comp_template_args is expensive, check it last. */
8330 && comp_template_args (TYPE_TI_ARGS (template_type),
8332 return template_type;
8334 /* If we already have this specialization, return it. */
8335 elt.tmpl = gen_tmpl;
8337 elt.spec = NULL_TREE;
8338 hash = spec_hasher::hash (&elt);
8339 entry = type_specializations->find_with_hash (&elt, hash);
8344 /* If the the template's constraints are not satisfied,
8345 then we cannot form a valid type.
8347 Note that the check is deferred until after the hash
8348 lookup. This prevents redundant checks on previously
8349 instantiated specializations. */
8350 if (flag_concepts && !constraints_satisfied_p (gen_tmpl, arglist))
8352 if (complain & tf_error)
8354 error ("template constraint failure");
8355 diagnose_constraints (input_location, gen_tmpl, arglist);
8357 return error_mark_node;
8360 is_dependent_type = uses_template_parms (arglist);
8362 /* If the deduced arguments are invalid, then the binding
8364 if (!is_dependent_type
8365 && check_instantiated_args (gen_tmpl,
8366 INNERMOST_TEMPLATE_ARGS (arglist),
8368 return error_mark_node;
8370 if (!is_dependent_type
8371 && !PRIMARY_TEMPLATE_P (gen_tmpl)
8372 && !LAMBDA_TYPE_P (TREE_TYPE (gen_tmpl))
8373 && TREE_CODE (CP_DECL_CONTEXT (gen_tmpl)) == NAMESPACE_DECL)
8375 found = xref_tag_from_type (TREE_TYPE (gen_tmpl),
8376 DECL_NAME (gen_tmpl),
8377 /*tag_scope=*/ts_global);
8381 context = tsubst (DECL_CONTEXT (gen_tmpl), arglist,
8383 if (context == error_mark_node)
8384 return error_mark_node;
8387 context = global_namespace;
8389 /* Create the type. */
8390 if (DECL_ALIAS_TEMPLATE_P (gen_tmpl))
8392 /* The user referred to a specialization of an alias
8393 template represented by GEN_TMPL.
8395 [temp.alias]/2 says:
8397 When a template-id refers to the specialization of an
8398 alias template, it is equivalent to the associated
8399 type obtained by substitution of its
8400 template-arguments for the template-parameters in the
8401 type-id of the alias template. */
8403 t = tsubst (TREE_TYPE (gen_tmpl), arglist, complain, in_decl);
8404 /* Note that the call above (by indirectly calling
8405 register_specialization in tsubst_decl) registers the
8406 TYPE_DECL representing the specialization of the alias
8407 template. So next time someone substitutes ARGLIST for
8408 the template parms into the alias template (GEN_TMPL),
8409 she'll get that TYPE_DECL back. */
8411 if (t == error_mark_node)
8414 else if (TREE_CODE (template_type) == ENUMERAL_TYPE)
8416 if (!is_dependent_type)
8418 set_current_access_from_decl (TYPE_NAME (template_type));
8419 t = start_enum (TYPE_IDENTIFIER (template_type), NULL_TREE,
8420 tsubst (ENUM_UNDERLYING_TYPE (template_type),
8421 arglist, complain, in_decl),
8422 tsubst_attributes (TYPE_ATTRIBUTES (template_type),
8423 arglist, complain, in_decl),
8424 SCOPED_ENUM_P (template_type), NULL);
8426 if (t == error_mark_node)
8431 /* We don't want to call start_enum for this type, since
8432 the values for the enumeration constants may involve
8433 template parameters. And, no one should be interested
8434 in the enumeration constants for such a type. */
8435 t = cxx_make_type (ENUMERAL_TYPE);
8436 SET_SCOPED_ENUM_P (t, SCOPED_ENUM_P (template_type));
8438 SET_OPAQUE_ENUM_P (t, OPAQUE_ENUM_P (template_type));
8439 ENUM_FIXED_UNDERLYING_TYPE_P (t)
8440 = ENUM_FIXED_UNDERLYING_TYPE_P (template_type);
8442 else if (CLASS_TYPE_P (template_type))
8444 t = make_class_type (TREE_CODE (template_type));
8445 CLASSTYPE_DECLARED_CLASS (t)
8446 = CLASSTYPE_DECLARED_CLASS (template_type);
8447 SET_CLASSTYPE_IMPLICIT_INSTANTIATION (t);
8448 TYPE_FOR_JAVA (t) = TYPE_FOR_JAVA (template_type);
8450 /* A local class. Make sure the decl gets registered properly. */
8451 if (context == current_function_decl)
8452 pushtag (DECL_NAME (gen_tmpl), t, /*tag_scope=*/ts_current);
8454 if (comp_template_args (CLASSTYPE_TI_ARGS (template_type), arglist))
8455 /* This instantiation is another name for the primary
8456 template type. Set the TYPE_CANONICAL field
8458 TYPE_CANONICAL (t) = template_type;
8459 else if (any_template_arguments_need_structural_equality_p (arglist))
8460 /* Some of the template arguments require structural
8461 equality testing, so this template class requires
8462 structural equality testing. */
8463 SET_TYPE_STRUCTURAL_EQUALITY (t);
8468 /* If we called start_enum or pushtag above, this information
8469 will already be set up. */
8472 TYPE_CONTEXT (t) = FROB_CONTEXT (context);
8474 type_decl = create_implicit_typedef (DECL_NAME (gen_tmpl), t);
8475 DECL_CONTEXT (type_decl) = TYPE_CONTEXT (t);
8476 DECL_SOURCE_LOCATION (type_decl)
8477 = DECL_SOURCE_LOCATION (TYPE_STUB_DECL (template_type));
8480 type_decl = TYPE_NAME (t);
8482 if (CLASS_TYPE_P (template_type))
8484 TREE_PRIVATE (type_decl)
8485 = TREE_PRIVATE (TYPE_MAIN_DECL (template_type));
8486 TREE_PROTECTED (type_decl)
8487 = TREE_PROTECTED (TYPE_MAIN_DECL (template_type));
8488 if (CLASSTYPE_VISIBILITY_SPECIFIED (template_type))
8490 DECL_VISIBILITY_SPECIFIED (type_decl) = 1;
8491 DECL_VISIBILITY (type_decl) = CLASSTYPE_VISIBILITY (template_type);
8495 if (OVERLOAD_TYPE_P (t)
8496 && !DECL_ALIAS_TEMPLATE_P (gen_tmpl))
8498 static const char *tags[] = {"abi_tag", "may_alias"};
8500 for (unsigned ix = 0; ix != 2; ix++)
8503 = lookup_attribute (tags[ix], TYPE_ATTRIBUTES (template_type));
8507 = tree_cons (TREE_PURPOSE (attributes),
8508 TREE_VALUE (attributes),
8509 TYPE_ATTRIBUTES (t));
8513 /* Let's consider the explicit specialization of a member
8514 of a class template specialization that is implicitly instantiated,
8519 template<class U> struct M {}; //#0
8524 struct S<int>::M<char> //#1
8528 [temp.expl.spec]/4 says this is valid.
8530 In this case, when we write:
8533 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
8536 When we encounter #1, we want to store the partial instantiation
8537 of M (template<class T> S<int>::M<T>) in its CLASSTYPE_TI_TEMPLATE.
8539 For all cases other than this "explicit specialization of member of a
8540 class template", we just want to store the most general template into
8541 the CLASSTYPE_TI_TEMPLATE of M.
8543 This case of "explicit specialization of member of a class template"
8545 1/ the enclosing class is an instantiation of, and therefore not
8546 the same as, the context of the most general template, and
8547 2/ we aren't looking at the partial instantiation itself, i.e.
8548 the innermost arguments are not the same as the innermost parms of
8549 the most general template.
8551 So it's only when 1/ and 2/ happens that we want to use the partial
8552 instantiation of the member template in lieu of its most general
8555 if (PRIMARY_TEMPLATE_P (gen_tmpl)
8556 && TMPL_ARGS_HAVE_MULTIPLE_LEVELS (arglist)
8557 /* the enclosing class must be an instantiation... */
8558 && CLASS_TYPE_P (context)
8559 && !same_type_p (context, DECL_CONTEXT (gen_tmpl)))
8561 tree partial_inst_args;
8562 TREE_VEC_LENGTH (arglist)--;
8563 ++processing_template_decl;
8565 tsubst (INNERMOST_TEMPLATE_ARGS
8566 (TYPE_TI_ARGS (TREE_TYPE (gen_tmpl))),
8567 arglist, complain, NULL_TREE);
8568 --processing_template_decl;
8569 TREE_VEC_LENGTH (arglist)++;
8570 if (partial_inst_args == error_mark_node)
8571 return error_mark_node;
8572 use_partial_inst_tmpl =
8573 /*...and we must not be looking at the partial instantiation
8575 !comp_template_args (INNERMOST_TEMPLATE_ARGS (arglist),
8579 if (!use_partial_inst_tmpl)
8580 /* This case is easy; there are no member templates involved. */
8584 /* This is a full instantiation of a member template. Find
8585 the partial instantiation of which this is an instance. */
8587 /* Temporarily reduce by one the number of levels in the ARGLIST
8588 so as to avoid comparing the last set of arguments. */
8589 TREE_VEC_LENGTH (arglist)--;
8590 found = tsubst (gen_tmpl, arglist, complain, NULL_TREE);
8591 TREE_VEC_LENGTH (arglist)++;
8592 /* FOUND is either a proper class type, or an alias
8593 template specialization. In the later case, it's a
8594 TYPE_DECL, resulting from the substituting of arguments
8595 for parameters in the TYPE_DECL of the alias template
8596 done earlier. So be careful while getting the template
8598 found = TREE_CODE (found) == TEMPLATE_DECL
8600 : TREE_CODE (found) == TYPE_DECL
8601 ? TYPE_TI_TEMPLATE (TREE_TYPE (found))
8602 : CLASSTYPE_TI_TEMPLATE (found);
8605 // Build template info for the new specialization.
8606 SET_TYPE_TEMPLATE_INFO (t, build_template_info (found, arglist));
8609 slot = type_specializations->find_slot_with_hash (&elt, hash, INSERT);
8610 entry = ggc_alloc<spec_entry> ();
8614 /* Note this use of the partial instantiation so we can check it
8615 later in maybe_process_partial_specialization. */
8616 DECL_TEMPLATE_INSTANTIATIONS (found)
8617 = tree_cons (arglist, t,
8618 DECL_TEMPLATE_INSTANTIATIONS (found));
8620 if (TREE_CODE (template_type) == ENUMERAL_TYPE && !is_dependent_type
8621 && !DECL_ALIAS_TEMPLATE_P (gen_tmpl))
8622 /* Now that the type has been registered on the instantiations
8623 list, we set up the enumerators. Because the enumeration
8624 constants may involve the enumeration type itself, we make
8625 sure to register the type first, and then create the
8626 constants. That way, doing tsubst_expr for the enumeration
8627 constants won't result in recursive calls here; we'll find
8628 the instantiation and exit above. */
8629 tsubst_enum (template_type, t, arglist);
8631 if (CLASS_TYPE_P (template_type) && is_dependent_type)
8632 /* If the type makes use of template parameters, the
8633 code that generates debugging information will crash. */
8634 DECL_IGNORED_P (TYPE_MAIN_DECL (t)) = 1;
8636 /* Possibly limit visibility based on template args. */
8637 TREE_PUBLIC (type_decl) = 1;
8638 determine_visibility (type_decl);
8640 inherit_targ_abi_tags (t);
8646 /* Wrapper for lookup_template_class_1. */
8649 lookup_template_class (tree d1, tree arglist, tree in_decl, tree context,
8650 int entering_scope, tsubst_flags_t complain)
8653 timevar_push (TV_TEMPLATE_INST);
8654 ret = lookup_template_class_1 (d1, arglist, in_decl, context,
8655 entering_scope, complain);
8656 timevar_pop (TV_TEMPLATE_INST);
8660 /* Return a TEMPLATE_ID_EXPR for the given variable template and ARGLIST. */
8663 lookup_template_variable (tree templ, tree arglist)
8665 /* The type of the expression is NULL_TREE since the template-id could refer
8666 to an explicit or partial specialization. */
8667 tree type = NULL_TREE;
8668 if (flag_concepts && variable_concept_p (templ))
8669 /* Except that concepts are always bool. */
8670 type = boolean_type_node;
8671 return build2 (TEMPLATE_ID_EXPR, type, templ, arglist);
8674 /* Instantiate a variable declaration from a TEMPLATE_ID_EXPR for use. */
8677 finish_template_variable (tree var, tsubst_flags_t complain)
8679 tree templ = TREE_OPERAND (var, 0);
8680 tree arglist = TREE_OPERAND (var, 1);
8682 /* We never want to return a VAR_DECL for a variable concept, since they
8683 aren't instantiated. In a template, leave the TEMPLATE_ID_EXPR alone. */
8684 bool concept_p = flag_concepts && variable_concept_p (templ);
8685 if (concept_p && processing_template_decl)
8688 tree tmpl_args = DECL_TI_ARGS (DECL_TEMPLATE_RESULT (templ));
8689 arglist = add_outermost_template_args (tmpl_args, arglist);
8691 tree parms = DECL_TEMPLATE_PARMS (templ);
8692 arglist = coerce_innermost_template_parms (parms, arglist, templ, complain,
8694 /*use_default*/true);
8696 if (flag_concepts && !constraints_satisfied_p (templ, arglist))
8698 if (complain & tf_error)
8700 error ("use of invalid variable template %qE", var);
8701 diagnose_constraints (location_of (var), templ, arglist);
8703 return error_mark_node;
8706 /* If a template-id refers to a specialization of a variable
8707 concept, then the expression is true if and only if the
8708 concept's constraints are satisfied by the given template
8711 NOTE: This is an extension of Concepts Lite TS that
8712 allows constraints to be used in expressions. */
8715 tree decl = DECL_TEMPLATE_RESULT (templ);
8716 return evaluate_variable_concept (decl, arglist);
8719 return instantiate_template (templ, arglist, complain);
8722 /* Construct a TEMPLATE_ID_EXPR for the given variable template TEMPL having
8723 TARGS template args, and instantiate it if it's not dependent. */
8726 lookup_and_finish_template_variable (tree templ, tree targs,
8727 tsubst_flags_t complain)
8729 templ = lookup_template_variable (templ, targs);
8730 if (!any_dependent_template_arguments_p (targs))
8732 templ = finish_template_variable (templ, complain);
8736 return convert_from_reference (templ);
8744 /* True when we should also visit template parameters that occur in
8745 non-deduced contexts. */
8746 bool include_nondeduced_p;
8747 hash_set<tree> *visited;
8750 /* Called from for_each_template_parm via walk_tree. */
8753 for_each_template_parm_r (tree *tp, int *walk_subtrees, void *d)
8756 struct pair_fn_data *pfd = (struct pair_fn_data *) d;
8757 tree_fn_t fn = pfd->fn;
8758 void *data = pfd->data;
8759 tree result = NULL_TREE;
8761 #define WALK_SUBTREE(NODE) \
8764 result = for_each_template_parm (NODE, fn, data, pfd->visited, \
8765 pfd->include_nondeduced_p); \
8766 if (result) goto out; \
8771 && (pfd->include_nondeduced_p || TREE_CODE (t) != TYPENAME_TYPE))
8772 WALK_SUBTREE (TYPE_CONTEXT (t));
8774 switch (TREE_CODE (t))
8777 if (TYPE_PTRMEMFUNC_P (t))
8783 if (!TYPE_TEMPLATE_INFO (t))
8786 WALK_SUBTREE (TYPE_TI_ARGS (t));
8790 WALK_SUBTREE (TYPE_MIN_VALUE (t));
8791 WALK_SUBTREE (TYPE_MAX_VALUE (t));
8795 /* Since we're not going to walk subtrees, we have to do this
8797 WALK_SUBTREE (TYPE_METHOD_BASETYPE (t));
8801 /* Check the return type. */
8802 WALK_SUBTREE (TREE_TYPE (t));
8804 /* Check the parameter types. Since default arguments are not
8805 instantiated until they are needed, the TYPE_ARG_TYPES may
8806 contain expressions that involve template parameters. But,
8807 no-one should be looking at them yet. And, once they're
8808 instantiated, they don't contain template parameters, so
8809 there's no point in looking at them then, either. */
8813 for (parm = TYPE_ARG_TYPES (t); parm; parm = TREE_CHAIN (parm))
8814 WALK_SUBTREE (TREE_VALUE (parm));
8816 /* Since we've already handled the TYPE_ARG_TYPES, we don't
8817 want walk_tree walking into them itself. */
8823 case UNDERLYING_TYPE:
8824 if (pfd->include_nondeduced_p
8825 && for_each_template_parm (TYPE_VALUES_RAW (t), fn, data,
8827 pfd->include_nondeduced_p))
8828 return error_mark_node;
8833 if (DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t))
8834 WALK_SUBTREE (DECL_TI_ARGS (t));
8839 if (TREE_CODE (t) == CONST_DECL && DECL_TEMPLATE_PARM_P (t))
8840 WALK_SUBTREE (DECL_INITIAL (t));
8841 if (DECL_CONTEXT (t)
8842 && pfd->include_nondeduced_p)
8843 WALK_SUBTREE (DECL_CONTEXT (t));
8846 case BOUND_TEMPLATE_TEMPLATE_PARM:
8847 /* Record template parameters such as `T' inside `TT<T>'. */
8848 WALK_SUBTREE (TYPE_TI_ARGS (t));
8851 case TEMPLATE_TEMPLATE_PARM:
8852 case TEMPLATE_TYPE_PARM:
8853 case TEMPLATE_PARM_INDEX:
8854 if (fn && (*fn)(t, data))
8861 /* A template template parameter is encountered. */
8862 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
8863 WALK_SUBTREE (TREE_TYPE (t));
8865 /* Already substituted template template parameter */
8870 /* A template-id in a TYPENAME_TYPE might be a deduced context after
8871 partial instantiation. */
8872 WALK_SUBTREE (TYPENAME_TYPE_FULLNAME (t));
8876 if (TREE_TYPE (t) && TYPE_PTRMEMFUNC_P (TREE_TYPE (t))
8877 && pfd->include_nondeduced_p)
8878 WALK_SUBTREE (TYPE_PTRMEMFUNC_FN_TYPE (TREE_TYPE (t)));
8883 /* If there's no type, then this thing must be some expression
8884 involving template parameters. */
8885 if (!fn && !TREE_TYPE (t))
8886 return error_mark_node;
8891 case IMPLICIT_CONV_EXPR:
8892 case REINTERPRET_CAST_EXPR:
8893 case CONST_CAST_EXPR:
8894 case STATIC_CAST_EXPR:
8895 case DYNAMIC_CAST_EXPR:
8899 case PSEUDO_DTOR_EXPR:
8901 return error_mark_node;
8910 /* We didn't find any template parameters we liked. */
8915 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
8916 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
8917 call FN with the parameter and the DATA.
8918 If FN returns nonzero, the iteration is terminated, and
8919 for_each_template_parm returns 1. Otherwise, the iteration
8920 continues. If FN never returns a nonzero value, the value
8921 returned by for_each_template_parm is 0. If FN is NULL, it is
8922 considered to be the function which always returns 1.
8924 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
8925 parameters that occur in non-deduced contexts. When false, only
8926 visits those template parameters that can be deduced. */
8929 for_each_template_parm (tree t, tree_fn_t fn, void* data,
8930 hash_set<tree> *visited,
8931 bool include_nondeduced_p)
8933 struct pair_fn_data pfd;
8939 pfd.include_nondeduced_p = include_nondeduced_p;
8941 /* Walk the tree. (Conceptually, we would like to walk without
8942 duplicates, but for_each_template_parm_r recursively calls
8943 for_each_template_parm, so we would need to reorganize a fair
8944 bit to use walk_tree_without_duplicates, so we keep our own
8947 pfd.visited = visited;
8949 pfd.visited = new hash_set<tree>;
8950 result = cp_walk_tree (&t,
8951 for_each_template_parm_r,
8965 /* Returns true if T depends on any template parameter. */
8968 uses_template_parms (tree t)
8974 int saved_processing_template_decl;
8976 saved_processing_template_decl = processing_template_decl;
8977 if (!saved_processing_template_decl)
8978 processing_template_decl = 1;
8980 dependent_p = dependent_type_p (t);
8981 else if (TREE_CODE (t) == TREE_VEC)
8982 dependent_p = any_dependent_template_arguments_p (t);
8983 else if (TREE_CODE (t) == TREE_LIST)
8984 dependent_p = (uses_template_parms (TREE_VALUE (t))
8985 || uses_template_parms (TREE_CHAIN (t)));
8986 else if (TREE_CODE (t) == TYPE_DECL)
8987 dependent_p = dependent_type_p (TREE_TYPE (t));
8990 || TREE_CODE (t) == TEMPLATE_PARM_INDEX
8991 || TREE_CODE (t) == OVERLOAD
8994 || TREE_CODE (t) == TRAIT_EXPR
8995 || TREE_CODE (t) == CONSTRUCTOR
8996 || CONSTANT_CLASS_P (t))
8997 dependent_p = (type_dependent_expression_p (t)
8998 || value_dependent_expression_p (t));
9001 gcc_assert (t == error_mark_node);
9002 dependent_p = false;
9005 processing_template_decl = saved_processing_template_decl;
9010 /* Returns true iff current_function_decl is an incompletely instantiated
9011 template. Useful instead of processing_template_decl because the latter
9012 is set to 0 during instantiate_non_dependent_expr. */
9015 in_template_function (void)
9017 tree fn = current_function_decl;
9019 ++processing_template_decl;
9020 ret = (fn && DECL_LANG_SPECIFIC (fn)
9021 && DECL_TEMPLATE_INFO (fn)
9022 && any_dependent_template_arguments_p (DECL_TI_ARGS (fn)));
9023 --processing_template_decl;
9027 /* Returns true if T depends on any template parameter with level LEVEL. */
9030 uses_template_parms_level (tree t, int level)
9032 return for_each_template_parm (t, template_parm_this_level_p, &level, NULL,
9033 /*include_nondeduced_p=*/true);
9036 /* Returns TRUE iff INST is an instantiation we don't need to do in an
9037 ill-formed translation unit, i.e. a variable or function that isn't
9038 usable in a constant expression. */
9041 neglectable_inst_p (tree d)
9044 && !(TREE_CODE (d) == FUNCTION_DECL ? DECL_DECLARED_CONSTEXPR_P (d)
9045 : decl_maybe_constant_var_p (d)));
9048 /* Returns TRUE iff we should refuse to instantiate DECL because it's
9049 neglectable and instantiated from within an erroneous instantiation. */
9052 limit_bad_template_recursion (tree decl)
9054 struct tinst_level *lev = current_tinst_level;
9055 int errs = errorcount + sorrycount;
9056 if (lev == NULL || errs == 0 || !neglectable_inst_p (decl))
9059 for (; lev; lev = lev->next)
9060 if (neglectable_inst_p (lev->decl))
9063 return (lev && errs > lev->errors);
9066 static int tinst_depth;
9067 extern int max_tinst_depth;
9070 static GTY(()) struct tinst_level *last_error_tinst_level;
9072 /* We're starting to instantiate D; record the template instantiation context
9073 for diagnostics and to restore it later. */
9076 push_tinst_level (tree d)
9078 return push_tinst_level_loc (d, input_location);
9081 /* We're starting to instantiate D; record the template instantiation context
9082 at LOC for diagnostics and to restore it later. */
9085 push_tinst_level_loc (tree d, location_t loc)
9087 struct tinst_level *new_level;
9089 if (tinst_depth >= max_tinst_depth)
9091 /* Tell error.c not to try to instantiate any templates. */
9093 fatal_error (input_location,
9094 "template instantiation depth exceeds maximum of %d"
9095 " (use -ftemplate-depth= to increase the maximum)",
9100 /* If the current instantiation caused problems, don't let it instantiate
9101 anything else. Do allow deduction substitution and decls usable in
9102 constant expressions. */
9103 if (limit_bad_template_recursion (d))
9106 new_level = ggc_alloc<tinst_level> ();
9107 new_level->decl = d;
9108 new_level->locus = loc;
9109 new_level->errors = errorcount+sorrycount;
9110 new_level->in_system_header_p = in_system_header_at (input_location);
9111 new_level->next = current_tinst_level;
9112 current_tinst_level = new_level;
9115 if (GATHER_STATISTICS && (tinst_depth > depth_reached))
9116 depth_reached = tinst_depth;
9121 /* We're done instantiating this template; return to the instantiation
9125 pop_tinst_level (void)
9127 /* Restore the filename and line number stashed away when we started
9128 this instantiation. */
9129 input_location = current_tinst_level->locus;
9130 current_tinst_level = current_tinst_level->next;
9134 /* We're instantiating a deferred template; restore the template
9135 instantiation context in which the instantiation was requested, which
9136 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
9139 reopen_tinst_level (struct tinst_level *level)
9141 struct tinst_level *t;
9144 for (t = level; t; t = t->next)
9147 current_tinst_level = level;
9149 if (current_tinst_level)
9150 current_tinst_level->errors = errorcount+sorrycount;
9154 /* Returns the TINST_LEVEL which gives the original instantiation
9157 struct tinst_level *
9158 outermost_tinst_level (void)
9160 struct tinst_level *level = current_tinst_level;
9163 level = level->next;
9167 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
9168 vector of template arguments, as for tsubst.
9170 Returns an appropriate tsubst'd friend declaration. */
9173 tsubst_friend_function (tree decl, tree args)
9177 if (TREE_CODE (decl) == FUNCTION_DECL
9178 && DECL_TEMPLATE_INSTANTIATION (decl)
9179 && TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
9180 /* This was a friend declared with an explicit template
9181 argument list, e.g.:
9185 to indicate that f was a template instantiation, not a new
9186 function declaration. Now, we have to figure out what
9187 instantiation of what template. */
9189 tree template_id, arglist, fns;
9192 tree ns = decl_namespace_context (TYPE_MAIN_DECL (current_class_type));
9194 /* Friend functions are looked up in the containing namespace scope.
9195 We must enter that scope, to avoid finding member functions of the
9196 current class with same name. */
9197 push_nested_namespace (ns);
9198 fns = tsubst_expr (DECL_TI_TEMPLATE (decl), args,
9199 tf_warning_or_error, NULL_TREE,
9200 /*integral_constant_expression_p=*/false);
9201 pop_nested_namespace (ns);
9202 arglist = tsubst (DECL_TI_ARGS (decl), args,
9203 tf_warning_or_error, NULL_TREE);
9204 template_id = lookup_template_function (fns, arglist);
9206 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
9207 tmpl = determine_specialization (template_id, new_friend,
9209 /*need_member_template=*/0,
9210 TREE_VEC_LENGTH (args),
9212 return instantiate_template (tmpl, new_args, tf_error);
9215 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
9217 /* The NEW_FRIEND will look like an instantiation, to the
9218 compiler, but is not an instantiation from the point of view of
9219 the language. For example, we might have had:
9221 template <class T> struct S {
9222 template <class U> friend void f(T, U);
9225 Then, in S<int>, template <class U> void f(int, U) is not an
9226 instantiation of anything. */
9227 if (new_friend == error_mark_node)
9228 return error_mark_node;
9230 DECL_USE_TEMPLATE (new_friend) = 0;
9231 if (TREE_CODE (decl) == TEMPLATE_DECL)
9233 DECL_USE_TEMPLATE (DECL_TEMPLATE_RESULT (new_friend)) = 0;
9234 DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (new_friend))
9235 = DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (decl));
9238 /* The mangled name for the NEW_FRIEND is incorrect. The function
9239 is not a template instantiation and should not be mangled like
9240 one. Therefore, we forget the mangling here; we'll recompute it
9241 later if we need it. */
9242 if (TREE_CODE (new_friend) != TEMPLATE_DECL)
9244 SET_DECL_RTL (new_friend, NULL);
9245 SET_DECL_ASSEMBLER_NAME (new_friend, NULL_TREE);
9248 if (DECL_NAMESPACE_SCOPE_P (new_friend))
9251 tree new_friend_template_info;
9252 tree new_friend_result_template_info;
9254 int new_friend_is_defn;
9256 /* We must save some information from NEW_FRIEND before calling
9257 duplicate decls since that function will free NEW_FRIEND if
9259 new_friend_template_info = DECL_TEMPLATE_INFO (new_friend);
9260 new_friend_is_defn =
9261 (DECL_INITIAL (DECL_TEMPLATE_RESULT
9262 (template_for_substitution (new_friend)))
9264 if (TREE_CODE (new_friend) == TEMPLATE_DECL)
9266 /* This declaration is a `primary' template. */
9267 DECL_PRIMARY_TEMPLATE (new_friend) = new_friend;
9269 new_friend_result_template_info
9270 = DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (new_friend));
9273 new_friend_result_template_info = NULL_TREE;
9275 /* Make the init_value nonzero so pushdecl knows this is a defn. */
9276 if (new_friend_is_defn)
9277 DECL_INITIAL (new_friend) = error_mark_node;
9279 /* Inside pushdecl_namespace_level, we will push into the
9280 current namespace. However, the friend function should go
9281 into the namespace of the template. */
9282 ns = decl_namespace_context (new_friend);
9283 push_nested_namespace (ns);
9284 old_decl = pushdecl_namespace_level (new_friend, /*is_friend=*/true);
9285 pop_nested_namespace (ns);
9287 if (old_decl == error_mark_node)
9288 return error_mark_node;
9290 if (old_decl != new_friend)
9292 /* This new friend declaration matched an existing
9293 declaration. For example, given:
9295 template <class T> void f(T);
9296 template <class U> class C {
9297 template <class T> friend void f(T) {}
9300 the friend declaration actually provides the definition
9301 of `f', once C has been instantiated for some type. So,
9302 old_decl will be the out-of-class template declaration,
9303 while new_friend is the in-class definition.
9305 But, if `f' was called before this point, the
9306 instantiation of `f' will have DECL_TI_ARGS corresponding
9307 to `T' but not to `U', references to which might appear
9308 in the definition of `f'. Previously, the most general
9309 template for an instantiation of `f' was the out-of-class
9310 version; now it is the in-class version. Therefore, we
9311 run through all specialization of `f', adding to their
9312 DECL_TI_ARGS appropriately. In particular, they need a
9313 new set of outer arguments, corresponding to the
9314 arguments for this class instantiation.
9316 The same situation can arise with something like this:
9319 template <class T> class C {
9323 when `C<int>' is instantiated. Now, `f(int)' is defined
9326 if (!new_friend_is_defn)
9327 /* On the other hand, if the in-class declaration does
9328 *not* provide a definition, then we don't want to alter
9329 existing definitions. We can just leave everything
9334 tree new_template = TI_TEMPLATE (new_friend_template_info);
9335 tree new_args = TI_ARGS (new_friend_template_info);
9337 /* Overwrite whatever template info was there before, if
9338 any, with the new template information pertaining to
9340 DECL_TEMPLATE_INFO (old_decl) = new_friend_template_info;
9342 if (TREE_CODE (old_decl) != TEMPLATE_DECL)
9344 /* We should have called reregister_specialization in
9346 gcc_assert (retrieve_specialization (new_template,
9350 /* Instantiate it if the global has already been used. */
9351 if (DECL_ODR_USED (old_decl))
9352 instantiate_decl (old_decl, /*defer_ok=*/true,
9353 /*expl_inst_class_mem_p=*/false);
9359 /* Indicate that the old function template is a partial
9361 DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (old_decl))
9362 = new_friend_result_template_info;
9364 gcc_assert (new_template
9365 == most_general_template (new_template));
9366 gcc_assert (new_template != old_decl);
9368 /* Reassign any specializations already in the hash table
9369 to the new more general template, and add the
9370 additional template args. */
9371 for (t = DECL_TEMPLATE_INSTANTIATIONS (old_decl);
9375 tree spec = TREE_VALUE (t);
9378 elt.tmpl = old_decl;
9379 elt.args = DECL_TI_ARGS (spec);
9380 elt.spec = NULL_TREE;
9382 decl_specializations->remove_elt (&elt);
9385 = add_outermost_template_args (new_args,
9386 DECL_TI_ARGS (spec));
9388 register_specialization
9389 (spec, new_template, DECL_TI_ARGS (spec), true, 0);
9392 DECL_TEMPLATE_INSTANTIATIONS (old_decl) = NULL_TREE;
9396 /* The information from NEW_FRIEND has been merged into OLD_DECL
9397 by duplicate_decls. */
9398 new_friend = old_decl;
9403 tree context = DECL_CONTEXT (new_friend);
9407 template <class T> class C {
9408 template <class U> friend void C1<U>::f (); // case 1
9409 friend void C2<T>::f (); // case 2
9411 we only need to make sure CONTEXT is a complete type for
9412 case 2. To distinguish between the two cases, we note that
9413 CONTEXT of case 1 remains dependent type after tsubst while
9414 this isn't true for case 2. */
9415 ++processing_template_decl;
9416 dependent_p = dependent_type_p (context);
9417 --processing_template_decl;
9420 && !complete_type_or_else (context, NULL_TREE))
9421 return error_mark_node;
9423 if (COMPLETE_TYPE_P (context))
9425 tree fn = new_friend;
9426 /* do_friend adds the TEMPLATE_DECL for any member friend
9427 template even if it isn't a member template, i.e.
9428 template <class T> friend A<T>::f();
9429 Look through it in that case. */
9430 if (TREE_CODE (fn) == TEMPLATE_DECL
9431 && !PRIMARY_TEMPLATE_P (fn))
9432 fn = DECL_TEMPLATE_RESULT (fn);
9433 /* Check to see that the declaration is really present, and,
9434 possibly obtain an improved declaration. */
9435 fn = check_classfn (context, fn, NULL_TREE);
9445 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
9446 template arguments, as for tsubst.
9448 Returns an appropriate tsubst'd friend type or error_mark_node on
9452 tsubst_friend_class (tree friend_tmpl, tree args)
9458 if (DECL_TEMPLATE_TEMPLATE_PARM_P (friend_tmpl))
9460 tree t = tsubst (TREE_TYPE (friend_tmpl), args, tf_none, NULL_TREE);
9461 return TREE_TYPE (t);
9464 context = CP_DECL_CONTEXT (friend_tmpl);
9466 if (context != global_namespace)
9468 if (TREE_CODE (context) == NAMESPACE_DECL)
9469 push_nested_namespace (context);
9471 push_nested_class (tsubst (context, args, tf_none, NULL_TREE));
9474 /* Look for a class template declaration. We look for hidden names
9475 because two friend declarations of the same template are the
9476 same. For example, in:
9479 template <typename> friend class F;
9481 template <typename> struct B {
9482 template <typename> friend class F;
9485 both F templates are the same. */
9486 tmpl = lookup_name_real (DECL_NAME (friend_tmpl), 0, 0,
9487 /*block_p=*/true, 0, LOOKUP_HIDDEN);
9489 /* But, if we don't find one, it might be because we're in a
9490 situation like this:
9498 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
9499 for `S<int>', not the TEMPLATE_DECL. */
9500 if (!tmpl || !DECL_CLASS_TEMPLATE_P (tmpl))
9502 tmpl = lookup_name_prefer_type (DECL_NAME (friend_tmpl), 1);
9503 tmpl = maybe_get_template_decl_from_type_decl (tmpl);
9506 if (tmpl && DECL_CLASS_TEMPLATE_P (tmpl))
9508 /* The friend template has already been declared. Just
9509 check to see that the declarations match, and install any new
9510 default parameters. We must tsubst the default parameters,
9511 of course. We only need the innermost template parameters
9512 because that is all that redeclare_class_template will look
9514 if (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (friend_tmpl))
9515 > TMPL_ARGS_DEPTH (args))
9518 location_t saved_input_location;
9519 parms = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_tmpl),
9520 args, tf_warning_or_error);
9522 saved_input_location = input_location;
9523 input_location = DECL_SOURCE_LOCATION (friend_tmpl);
9524 tree cons = get_constraints (tmpl);
9525 redeclare_class_template (TREE_TYPE (tmpl), parms, cons);
9526 input_location = saved_input_location;
9530 friend_type = TREE_TYPE (tmpl);
9534 /* The friend template has not already been declared. In this
9535 case, the instantiation of the template class will cause the
9536 injection of this template into the global scope. */
9537 tmpl = tsubst (friend_tmpl, args, tf_warning_or_error, NULL_TREE);
9538 if (tmpl == error_mark_node)
9539 return error_mark_node;
9541 /* The new TMPL is not an instantiation of anything, so we
9542 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
9543 the new type because that is supposed to be the corresponding
9544 template decl, i.e., TMPL. */
9545 DECL_USE_TEMPLATE (tmpl) = 0;
9546 DECL_TEMPLATE_INFO (tmpl) = NULL_TREE;
9547 CLASSTYPE_USE_TEMPLATE (TREE_TYPE (tmpl)) = 0;
9548 CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl))
9549 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl)));
9551 /* Inject this template into the global scope. */
9552 friend_type = TREE_TYPE (pushdecl_top_level_maybe_friend (tmpl, true));
9555 if (context != global_namespace)
9557 if (TREE_CODE (context) == NAMESPACE_DECL)
9558 pop_nested_namespace (context);
9560 pop_nested_class ();
9566 /* Returns zero if TYPE cannot be completed later due to circularity.
9567 Otherwise returns one. */
9570 can_complete_type_without_circularity (tree type)
9572 if (type == NULL_TREE || type == error_mark_node)
9574 else if (COMPLETE_TYPE_P (type))
9576 else if (TREE_CODE (type) == ARRAY_TYPE)
9577 return can_complete_type_without_circularity (TREE_TYPE (type));
9578 else if (CLASS_TYPE_P (type)
9579 && TYPE_BEING_DEFINED (TYPE_MAIN_VARIANT (type)))
9585 static tree tsubst_omp_clauses (tree, bool, bool, tree, tsubst_flags_t, tree);
9587 /* Instantiate a single dependent attribute T (a TREE_LIST), and return either
9588 T or a new TREE_LIST, possibly a chain in the case of a pack expansion. */
9591 tsubst_attribute (tree t, tree *decl_p, tree args,
9592 tsubst_flags_t complain, tree in_decl)
9594 gcc_assert (ATTR_IS_DEPENDENT (t));
9596 tree val = TREE_VALUE (t);
9597 if (val == NULL_TREE)
9598 /* Nothing to do. */;
9599 else if ((flag_openmp || flag_openmp_simd || flag_cilkplus)
9600 && is_attribute_p ("omp declare simd",
9601 get_attribute_name (t)))
9603 tree clauses = TREE_VALUE (val);
9604 clauses = tsubst_omp_clauses (clauses, true, false, args,
9606 c_omp_declare_simd_clauses_to_decls (*decl_p, clauses);
9607 clauses = finish_omp_clauses (clauses, false, true);
9608 tree parms = DECL_ARGUMENTS (*decl_p);
9610 = c_omp_declare_simd_clauses_to_numbers (parms, clauses);
9612 val = build_tree_list (NULL_TREE, clauses);
9616 /* If the first attribute argument is an identifier, don't
9617 pass it through tsubst. Attributes like mode, format,
9618 cleanup and several target specific attributes expect it
9620 else if (attribute_takes_identifier_p (get_attribute_name (t)))
9623 = tsubst_expr (TREE_CHAIN (val), args, complain, in_decl,
9624 /*integral_constant_expression_p=*/false);
9625 if (chain != TREE_CHAIN (val))
9626 val = tree_cons (NULL_TREE, TREE_VALUE (val), chain);
9628 else if (PACK_EXPANSION_P (val))
9630 /* An attribute pack expansion. */
9631 tree purp = TREE_PURPOSE (t);
9632 tree pack = tsubst_pack_expansion (val, args, complain, in_decl);
9633 int len = TREE_VEC_LENGTH (pack);
9634 tree list = NULL_TREE;
9636 for (int i = 0; i < len; ++i)
9638 tree elt = TREE_VEC_ELT (pack, i);
9639 *q = build_tree_list (purp, elt);
9640 q = &TREE_CHAIN (*q);
9645 val = tsubst_expr (val, args, complain, in_decl,
9646 /*integral_constant_expression_p=*/false);
9648 if (val != TREE_VALUE (t))
9649 return build_tree_list (TREE_PURPOSE (t), val);
9653 /* Instantiate any dependent attributes in ATTRIBUTES, returning either it
9654 unchanged or a new TREE_LIST chain. */
9657 tsubst_attributes (tree attributes, tree args,
9658 tsubst_flags_t complain, tree in_decl)
9660 tree last_dep = NULL_TREE;
9662 for (tree t = attributes; t; t = TREE_CHAIN (t))
9663 if (ATTR_IS_DEPENDENT (t))
9666 attributes = copy_list (attributes);
9671 for (tree *p = &attributes; *p; )
9674 if (ATTR_IS_DEPENDENT (t))
9676 tree subst = tsubst_attribute (t, NULL, args, complain, in_decl);
9681 p = &TREE_CHAIN (*p);
9683 *p = TREE_CHAIN (t);
9687 p = &TREE_CHAIN (*p);
9693 /* Apply any attributes which had to be deferred until instantiation
9694 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
9695 ARGS, COMPLAIN, IN_DECL are as tsubst. */
9698 apply_late_template_attributes (tree *decl_p, tree attributes, int attr_flags,
9699 tree args, tsubst_flags_t complain, tree in_decl)
9701 tree last_dep = NULL_TREE;
9705 for (t = attributes; t; t = TREE_CHAIN (t))
9706 if (ATTR_IS_DEPENDENT (t))
9709 attributes = copy_list (attributes);
9713 if (DECL_P (*decl_p))
9715 if (TREE_TYPE (*decl_p) == error_mark_node)
9717 p = &DECL_ATTRIBUTES (*decl_p);
9720 p = &TYPE_ATTRIBUTES (*decl_p);
9724 tree late_attrs = NULL_TREE;
9725 tree *q = &late_attrs;
9727 for (*p = attributes; *p; )
9730 if (ATTR_IS_DEPENDENT (t))
9732 *p = TREE_CHAIN (t);
9733 TREE_CHAIN (t) = NULL_TREE;
9734 *q = tsubst_attribute (t, decl_p, args, complain, in_decl);
9736 q = &TREE_CHAIN (*q);
9740 p = &TREE_CHAIN (t);
9743 cplus_decl_attributes (decl_p, late_attrs, attr_flags);
9747 /* Perform (or defer) access check for typedefs that were referenced
9748 from within the template TMPL code.
9749 This is a subroutine of instantiate_decl and instantiate_class_template.
9750 TMPL is the template to consider and TARGS is the list of arguments of
9754 perform_typedefs_access_check (tree tmpl, tree targs)
9756 location_t saved_location;
9758 qualified_typedef_usage_t *iter;
9761 || (!CLASS_TYPE_P (tmpl)
9762 && TREE_CODE (tmpl) != FUNCTION_DECL))
9765 saved_location = input_location;
9766 FOR_EACH_VEC_SAFE_ELT (get_types_needing_access_check (tmpl), i, iter)
9768 tree type_decl = iter->typedef_decl;
9769 tree type_scope = iter->context;
9771 if (!type_decl || !type_scope || !CLASS_TYPE_P (type_scope))
9774 if (uses_template_parms (type_decl))
9775 type_decl = tsubst (type_decl, targs, tf_error, NULL_TREE);
9776 if (uses_template_parms (type_scope))
9777 type_scope = tsubst (type_scope, targs, tf_error, NULL_TREE);
9779 /* Make access check error messages point to the location
9780 of the use of the typedef. */
9781 input_location = iter->locus;
9782 perform_or_defer_access_check (TYPE_BINFO (type_scope),
9783 type_decl, type_decl,
9784 tf_warning_or_error);
9786 input_location = saved_location;
9790 instantiate_class_template_1 (tree type)
9792 tree templ, args, pattern, t, member;
9796 unsigned int saved_maximum_field_alignment;
9799 if (type == error_mark_node)
9800 return error_mark_node;
9802 if (COMPLETE_OR_OPEN_TYPE_P (type)
9803 || uses_template_parms (type))
9806 /* Figure out which template is being instantiated. */
9807 templ = most_general_template (CLASSTYPE_TI_TEMPLATE (type));
9808 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
9810 /* Determine what specialization of the original template to
9812 t = most_specialized_partial_spec (type, tf_warning_or_error);
9813 if (t == error_mark_node)
9815 TYPE_BEING_DEFINED (type) = 1;
9816 return error_mark_node;
9820 /* This TYPE is actually an instantiation of a partial
9821 specialization. We replace the innermost set of ARGS with
9822 the arguments appropriate for substitution. For example,
9825 template <class T> struct S {};
9826 template <class T> struct S<T*> {};
9828 and supposing that we are instantiating S<int*>, ARGS will
9829 presently be {int*} -- but we need {int}. */
9830 pattern = TREE_TYPE (t);
9831 args = TREE_PURPOSE (t);
9835 pattern = TREE_TYPE (templ);
9836 args = CLASSTYPE_TI_ARGS (type);
9839 /* If the template we're instantiating is incomplete, then clearly
9840 there's nothing we can do. */
9841 if (!COMPLETE_TYPE_P (pattern))
9844 /* If we've recursively instantiated too many templates, stop. */
9845 if (! push_tinst_level (type))
9848 /* Now we're really doing the instantiation. Mark the type as in
9849 the process of being defined. */
9850 TYPE_BEING_DEFINED (type) = 1;
9852 /* We may be in the middle of deferred access check. Disable
9854 push_deferring_access_checks (dk_no_deferred);
9856 int saved_unevaluated_operand = cp_unevaluated_operand;
9857 int saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
9859 fn_context = decl_function_context (TYPE_MAIN_DECL (type));
9860 /* Also avoid push_to_top_level for a lambda in an NSDMI. */
9861 if (!fn_context && LAMBDA_TYPE_P (type) && TYPE_CLASS_SCOPE_P (type))
9862 fn_context = error_mark_node;
9864 push_to_top_level ();
9867 cp_unevaluated_operand = 0;
9868 c_inhibit_evaluation_warnings = 0;
9870 /* Use #pragma pack from the template context. */
9871 saved_maximum_field_alignment = maximum_field_alignment;
9872 maximum_field_alignment = TYPE_PRECISION (pattern);
9874 SET_CLASSTYPE_INTERFACE_UNKNOWN (type);
9876 /* Set the input location to the most specialized template definition.
9877 This is needed if tsubsting causes an error. */
9878 typedecl = TYPE_MAIN_DECL (pattern);
9879 input_location = DECL_SOURCE_LOCATION (TYPE_NAME (type)) =
9880 DECL_SOURCE_LOCATION (typedecl);
9882 TYPE_PACKED (type) = TYPE_PACKED (pattern);
9883 TYPE_ALIGN (type) = TYPE_ALIGN (pattern);
9884 TYPE_USER_ALIGN (type) = TYPE_USER_ALIGN (pattern);
9885 TYPE_FOR_JAVA (type) = TYPE_FOR_JAVA (pattern); /* For libjava's JArray<T> */
9886 if (ANON_AGGR_TYPE_P (pattern))
9887 SET_ANON_AGGR_TYPE_P (type);
9888 if (CLASSTYPE_VISIBILITY_SPECIFIED (pattern))
9890 CLASSTYPE_VISIBILITY_SPECIFIED (type) = 1;
9891 CLASSTYPE_VISIBILITY (type) = CLASSTYPE_VISIBILITY (pattern);
9892 /* Adjust visibility for template arguments. */
9893 determine_visibility (TYPE_MAIN_DECL (type));
9895 if (CLASS_TYPE_P (type))
9896 CLASSTYPE_FINAL (type) = CLASSTYPE_FINAL (pattern);
9898 pbinfo = TYPE_BINFO (pattern);
9900 /* We should never instantiate a nested class before its enclosing
9901 class; we need to look up the nested class by name before we can
9902 instantiate it, and that lookup should instantiate the enclosing
9904 gcc_assert (!DECL_CLASS_SCOPE_P (TYPE_MAIN_DECL (pattern))
9905 || COMPLETE_OR_OPEN_TYPE_P (TYPE_CONTEXT (type)));
9907 base_list = NULL_TREE;
9908 if (BINFO_N_BASE_BINFOS (pbinfo))
9914 /* We must enter the scope containing the type, as that is where
9915 the accessibility of types named in dependent bases are
9917 pushed_scope = push_scope (CP_TYPE_CONTEXT (type));
9919 /* Substitute into each of the bases to determine the actual
9921 for (i = 0; BINFO_BASE_ITERATE (pbinfo, i, pbase_binfo); i++)
9924 tree access = BINFO_BASE_ACCESS (pbinfo, i);
9925 tree expanded_bases = NULL_TREE;
9928 if (PACK_EXPANSION_P (BINFO_TYPE (pbase_binfo)))
9931 tsubst_pack_expansion (BINFO_TYPE (pbase_binfo),
9932 args, tf_error, NULL_TREE);
9933 if (expanded_bases == error_mark_node)
9936 len = TREE_VEC_LENGTH (expanded_bases);
9939 for (idx = 0; idx < len; idx++)
9942 /* Extract the already-expanded base class. */
9943 base = TREE_VEC_ELT (expanded_bases, idx);
9945 /* Substitute to figure out the base class. */
9946 base = tsubst (BINFO_TYPE (pbase_binfo), args, tf_error,
9949 if (base == error_mark_node)
9952 base_list = tree_cons (access, base, base_list);
9953 if (BINFO_VIRTUAL_P (pbase_binfo))
9954 TREE_TYPE (base_list) = integer_type_node;
9958 /* The list is now in reverse order; correct that. */
9959 base_list = nreverse (base_list);
9962 pop_scope (pushed_scope);
9964 /* Now call xref_basetypes to set up all the base-class
9966 xref_basetypes (type, base_list);
9968 apply_late_template_attributes (&type, TYPE_ATTRIBUTES (pattern),
9969 (int) ATTR_FLAG_TYPE_IN_PLACE,
9970 args, tf_error, NULL_TREE);
9971 fixup_attribute_variants (type);
9973 /* Now that our base classes are set up, enter the scope of the
9974 class, so that name lookups into base classes, etc. will work
9975 correctly. This is precisely analogous to what we do in
9976 begin_class_definition when defining an ordinary non-template
9977 class, except we also need to push the enclosing classes. */
9978 push_nested_class (type);
9980 /* Now members are processed in the order of declaration. */
9981 for (member = CLASSTYPE_DECL_LIST (pattern);
9982 member; member = TREE_CHAIN (member))
9984 tree t = TREE_VALUE (member);
9986 if (TREE_PURPOSE (member))
9990 /* Build new CLASSTYPE_NESTED_UTDS. */
9993 bool class_template_p;
9995 class_template_p = (TREE_CODE (t) != ENUMERAL_TYPE
9996 && TYPE_LANG_SPECIFIC (t)
9997 && CLASSTYPE_IS_TEMPLATE (t));
9998 /* If the member is a class template, then -- even after
9999 substitution -- there may be dependent types in the
10000 template argument list for the class. We increment
10001 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
10002 that function will assume that no types are dependent
10003 when outside of a template. */
10004 if (class_template_p)
10005 ++processing_template_decl;
10006 newtag = tsubst (t, args, tf_error, NULL_TREE);
10007 if (class_template_p)
10008 --processing_template_decl;
10009 if (newtag == error_mark_node)
10012 if (TREE_CODE (newtag) != ENUMERAL_TYPE)
10014 tree name = TYPE_IDENTIFIER (t);
10016 if (class_template_p)
10017 /* Unfortunately, lookup_template_class sets
10018 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
10019 instantiation (i.e., for the type of a member
10020 template class nested within a template class.)
10021 This behavior is required for
10022 maybe_process_partial_specialization to work
10023 correctly, but is not accurate in this case;
10024 the TAG is not an instantiation of anything.
10025 (The corresponding TEMPLATE_DECL is an
10026 instantiation, but the TYPE is not.) */
10027 CLASSTYPE_USE_TEMPLATE (newtag) = 0;
10029 /* Now, we call pushtag to put this NEWTAG into the scope of
10030 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
10031 pushtag calling push_template_decl. We don't have to do
10032 this for enums because it will already have been done in
10035 SET_IDENTIFIER_TYPE_VALUE (name, newtag);
10036 pushtag (name, newtag, /*tag_scope=*/ts_current);
10039 else if (DECL_DECLARES_FUNCTION_P (t))
10041 /* Build new TYPE_METHODS. */
10044 if (TREE_CODE (t) == TEMPLATE_DECL)
10045 ++processing_template_decl;
10046 r = tsubst (t, args, tf_error, NULL_TREE);
10047 if (TREE_CODE (t) == TEMPLATE_DECL)
10048 --processing_template_decl;
10049 set_current_access_from_decl (r);
10050 finish_member_declaration (r);
10051 /* Instantiate members marked with attribute used. */
10052 if (r != error_mark_node && DECL_PRESERVE_P (r))
10054 if (TREE_CODE (r) == FUNCTION_DECL
10055 && DECL_OMP_DECLARE_REDUCTION_P (r))
10056 cp_check_omp_declare_reduction (r);
10058 else if (DECL_CLASS_TEMPLATE_P (t)
10059 && LAMBDA_TYPE_P (TREE_TYPE (t)))
10060 /* A closure type for a lambda in a default argument for a
10061 member template. Ignore it; it will be instantiated with
10062 the default argument. */;
10065 /* Build new TYPE_FIELDS. */
10066 if (TREE_CODE (t) == STATIC_ASSERT)
10070 ++c_inhibit_evaluation_warnings;
10072 tsubst_expr (STATIC_ASSERT_CONDITION (t), args,
10073 tf_warning_or_error, NULL_TREE,
10074 /*integral_constant_expression_p=*/true);
10075 --c_inhibit_evaluation_warnings;
10077 finish_static_assert (condition,
10078 STATIC_ASSERT_MESSAGE (t),
10079 STATIC_ASSERT_SOURCE_LOCATION (t),
10080 /*member_p=*/true);
10082 else if (TREE_CODE (t) != CONST_DECL)
10085 tree vec = NULL_TREE;
10088 /* The file and line for this declaration, to
10089 assist in error message reporting. Since we
10090 called push_tinst_level above, we don't need to
10092 input_location = DECL_SOURCE_LOCATION (t);
10094 if (TREE_CODE (t) == TEMPLATE_DECL)
10095 ++processing_template_decl;
10096 r = tsubst (t, args, tf_warning_or_error, NULL_TREE);
10097 if (TREE_CODE (t) == TEMPLATE_DECL)
10098 --processing_template_decl;
10100 if (TREE_CODE (r) == TREE_VEC)
10102 /* A capture pack became multiple fields. */
10104 len = TREE_VEC_LENGTH (vec);
10107 for (int i = 0; i < len; ++i)
10110 r = TREE_VEC_ELT (vec, i);
10115 [t]he initialization (and any associated
10116 side-effects) of a static data member does
10117 not occur unless the static data member is
10118 itself used in a way that requires the
10119 definition of the static data member to
10122 Therefore, we do not substitute into the
10123 initialized for the static data member here. */
10124 finish_static_data_member_decl
10126 /*init=*/NULL_TREE,
10127 /*init_const_expr_p=*/false,
10128 /*asmspec_tree=*/NULL_TREE,
10130 /* Instantiate members marked with attribute used. */
10131 if (r != error_mark_node && DECL_PRESERVE_P (r))
10134 else if (TREE_CODE (r) == FIELD_DECL)
10136 /* Determine whether R has a valid type and can be
10137 completed later. If R is invalid, then its type
10138 is replaced by error_mark_node. */
10139 tree rtype = TREE_TYPE (r);
10140 if (can_complete_type_without_circularity (rtype))
10141 complete_type (rtype);
10143 if (!complete_or_array_type_p (rtype))
10145 /* If R's type couldn't be completed and
10146 it isn't a flexible array member (whose
10147 type is incomplete by definition) give
10149 cxx_incomplete_type_error (r, rtype);
10150 TREE_TYPE (r) = error_mark_node;
10154 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
10155 such a thing will already have been added to the field
10156 list by tsubst_enum in finish_member_declaration in the
10157 CLASSTYPE_NESTED_UTDS case above. */
10158 if (!(TREE_CODE (r) == TYPE_DECL
10159 && TREE_CODE (TREE_TYPE (r)) == ENUMERAL_TYPE
10160 && DECL_ARTIFICIAL (r)))
10162 set_current_access_from_decl (r);
10163 finish_member_declaration (r);
10171 if (TYPE_P (t) || DECL_CLASS_TEMPLATE_P (t)
10172 || DECL_TEMPLATE_TEMPLATE_PARM_P (t))
10174 /* Build new CLASSTYPE_FRIEND_CLASSES. */
10176 tree friend_type = t;
10177 bool adjust_processing_template_decl = false;
10179 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
10181 /* template <class T> friend class C; */
10182 friend_type = tsubst_friend_class (friend_type, args);
10183 adjust_processing_template_decl = true;
10185 else if (TREE_CODE (friend_type) == UNBOUND_CLASS_TEMPLATE)
10187 /* template <class T> friend class C::D; */
10188 friend_type = tsubst (friend_type, args,
10189 tf_warning_or_error, NULL_TREE);
10190 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
10191 friend_type = TREE_TYPE (friend_type);
10192 adjust_processing_template_decl = true;
10194 else if (TREE_CODE (friend_type) == TYPENAME_TYPE
10195 || TREE_CODE (friend_type) == TEMPLATE_TYPE_PARM)
10197 /* This could be either
10201 when dependent_type_p is false or
10203 template <class U> friend class T::C;
10206 /* Bump processing_template_decl in case this is something like
10207 template <class T> friend struct A<T>::B. */
10208 ++processing_template_decl;
10209 friend_type = tsubst (friend_type, args,
10210 tf_warning_or_error, NULL_TREE);
10211 if (dependent_type_p (friend_type))
10212 adjust_processing_template_decl = true;
10213 --processing_template_decl;
10215 else if (!CLASSTYPE_USE_TEMPLATE (friend_type)
10216 && hidden_name_p (TYPE_NAME (friend_type)))
10220 where C hasn't been declared yet. Let's lookup name
10221 from namespace scope directly, bypassing any name that
10222 come from dependent base class. */
10223 tree ns = decl_namespace_context (TYPE_MAIN_DECL (friend_type));
10225 /* The call to xref_tag_from_type does injection for friend
10227 push_nested_namespace (ns);
10229 xref_tag_from_type (friend_type, NULL_TREE,
10230 /*tag_scope=*/ts_current);
10231 pop_nested_namespace (ns);
10233 else if (uses_template_parms (friend_type))
10234 /* friend class C<T>; */
10235 friend_type = tsubst (friend_type, args,
10236 tf_warning_or_error, NULL_TREE);
10241 where C is already declared or
10243 friend class C<int>;
10245 We don't have to do anything in these cases. */
10247 if (adjust_processing_template_decl)
10248 /* Trick make_friend_class into realizing that the friend
10249 we're adding is a template, not an ordinary class. It's
10250 important that we use make_friend_class since it will
10251 perform some error-checking and output cross-reference
10253 ++processing_template_decl;
10255 if (friend_type != error_mark_node)
10256 make_friend_class (type, friend_type, /*complain=*/false);
10258 if (adjust_processing_template_decl)
10259 --processing_template_decl;
10263 /* Build new DECL_FRIENDLIST. */
10266 /* The file and line for this declaration, to
10267 assist in error message reporting. Since we
10268 called push_tinst_level above, we don't need to
10270 input_location = DECL_SOURCE_LOCATION (t);
10272 if (TREE_CODE (t) == TEMPLATE_DECL)
10274 ++processing_template_decl;
10275 push_deferring_access_checks (dk_no_check);
10278 r = tsubst_friend_function (t, args);
10279 add_friend (type, r, /*complain=*/false);
10280 if (TREE_CODE (t) == TEMPLATE_DECL)
10282 pop_deferring_access_checks ();
10283 --processing_template_decl;
10291 /* Restore these before substituting into the lambda capture
10293 cp_unevaluated_operand = saved_unevaluated_operand;
10294 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
10297 if (tree expr = CLASSTYPE_LAMBDA_EXPR (type))
10299 tree decl = lambda_function (type);
10302 if (!DECL_TEMPLATE_INFO (decl)
10303 || DECL_TEMPLATE_RESULT (DECL_TI_TEMPLATE (decl)) != decl)
10305 /* Set function_depth to avoid garbage collection. */
10307 instantiate_decl (decl, false, false);
10311 /* We need to instantiate the capture list from the template
10312 after we've instantiated the closure members, but before we
10313 consider adding the conversion op. Also keep any captures
10314 that may have been added during instantiation of the op(). */
10315 tree tmpl_expr = CLASSTYPE_LAMBDA_EXPR (pattern);
10317 = tsubst_copy_and_build (LAMBDA_EXPR_CAPTURE_LIST (tmpl_expr),
10318 args, tf_warning_or_error, NULL_TREE,
10321 LAMBDA_EXPR_CAPTURE_LIST (expr)
10322 = chainon (tmpl_cap, nreverse (LAMBDA_EXPR_CAPTURE_LIST (expr)));
10324 maybe_add_lambda_conv_op (type);
10327 gcc_assert (errorcount);
10330 /* Set the file and line number information to whatever is given for
10331 the class itself. This puts error messages involving generated
10332 implicit functions at a predictable point, and the same point
10333 that would be used for non-template classes. */
10334 input_location = DECL_SOURCE_LOCATION (typedecl);
10336 unreverse_member_declarations (type);
10337 finish_struct_1 (type);
10338 TYPE_BEING_DEFINED (type) = 0;
10340 /* We don't instantiate default arguments for member functions. 14.7.1:
10342 The implicit instantiation of a class template specialization causes
10343 the implicit instantiation of the declarations, but not of the
10344 definitions or default arguments, of the class member functions,
10345 member classes, static data members and member templates.... */
10347 /* Some typedefs referenced from within the template code need to be access
10348 checked at template instantiation time, i.e now. These types were
10349 added to the template at parsing time. Let's get those and perform
10350 the access checks then. */
10351 perform_typedefs_access_check (pattern, args);
10352 perform_deferred_access_checks (tf_warning_or_error);
10353 pop_nested_class ();
10354 maximum_field_alignment = saved_maximum_field_alignment;
10356 pop_from_top_level ();
10357 pop_deferring_access_checks ();
10358 pop_tinst_level ();
10360 /* The vtable for a template class can be emitted in any translation
10361 unit in which the class is instantiated. When there is no key
10362 method, however, finish_struct_1 will already have added TYPE to
10363 the keyed_classes list. */
10364 if (TYPE_CONTAINS_VPTR_P (type) && CLASSTYPE_KEY_METHOD (type))
10365 keyed_classes = tree_cons (NULL_TREE, type, keyed_classes);
10370 /* Wrapper for instantiate_class_template_1. */
10373 instantiate_class_template (tree type)
10376 timevar_push (TV_TEMPLATE_INST);
10377 ret = instantiate_class_template_1 (type);
10378 timevar_pop (TV_TEMPLATE_INST);
10383 tsubst_template_arg (tree t, tree args, tsubst_flags_t complain, tree in_decl)
10389 else if (TYPE_P (t))
10390 r = tsubst (t, args, complain, in_decl);
10393 if (!(complain & tf_warning))
10394 ++c_inhibit_evaluation_warnings;
10395 r = tsubst_expr (t, args, complain, in_decl,
10396 /*integral_constant_expression_p=*/true);
10397 if (!(complain & tf_warning))
10398 --c_inhibit_evaluation_warnings;
10403 /* Given a function parameter pack TMPL_PARM and some function parameters
10404 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
10405 and set *SPEC_P to point at the next point in the list. */
10408 extract_fnparm_pack (tree tmpl_parm, tree *spec_p)
10410 /* Collect all of the extra "packed" parameters into an
10414 tree argpack = make_node (NONTYPE_ARGUMENT_PACK);
10415 tree argtypepack = cxx_make_type (TYPE_ARGUMENT_PACK);
10416 tree spec_parm = *spec_p;
10419 for (len = 0; spec_parm; ++len, spec_parm = TREE_CHAIN (spec_parm))
10421 && !function_parameter_expanded_from_pack_p (spec_parm, tmpl_parm))
10424 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
10425 parmvec = make_tree_vec (len);
10426 parmtypevec = make_tree_vec (len);
10427 spec_parm = *spec_p;
10428 for (i = 0; i < len; i++, spec_parm = DECL_CHAIN (spec_parm))
10430 TREE_VEC_ELT (parmvec, i) = spec_parm;
10431 TREE_VEC_ELT (parmtypevec, i) = TREE_TYPE (spec_parm);
10434 /* Build the argument packs. */
10435 SET_ARGUMENT_PACK_ARGS (argpack, parmvec);
10436 SET_ARGUMENT_PACK_ARGS (argtypepack, parmtypevec);
10437 TREE_TYPE (argpack) = argtypepack;
10438 *spec_p = spec_parm;
10443 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
10444 NONTYPE_ARGUMENT_PACK. */
10447 make_fnparm_pack (tree spec_parm)
10449 return extract_fnparm_pack (NULL_TREE, &spec_parm);
10452 /* Return 1 if the Ith element of the argument pack ARG_PACK is a
10453 pack expansion with no extra args, 2 if it has extra args, or 0
10454 if it is not a pack expansion. */
10457 argument_pack_element_is_expansion_p (tree arg_pack, int i)
10459 tree vec = ARGUMENT_PACK_ARGS (arg_pack);
10460 if (i >= TREE_VEC_LENGTH (vec))
10462 tree elt = TREE_VEC_ELT (vec, i);
10464 /* A decl pack is itself an expansion. */
10465 elt = TREE_TYPE (elt);
10466 if (!PACK_EXPANSION_P (elt))
10468 if (PACK_EXPANSION_EXTRA_ARGS (elt))
10474 /* Creates and return an ARGUMENT_PACK_SELECT tree node. */
10477 make_argument_pack_select (tree arg_pack, unsigned index)
10479 tree aps = make_node (ARGUMENT_PACK_SELECT);
10481 ARGUMENT_PACK_SELECT_FROM_PACK (aps) = arg_pack;
10482 ARGUMENT_PACK_SELECT_INDEX (aps) = index;
10487 /* This is a subroutine of tsubst_pack_expansion.
10489 It returns TRUE if we need to use the PACK_EXPANSION_EXTRA_ARGS
10490 mechanism to store the (non complete list of) arguments of the
10491 substitution and return a non substituted pack expansion, in order
10492 to wait for when we have enough arguments to really perform the
10496 use_pack_expansion_extra_args_p (tree parm_packs,
10498 bool has_empty_arg)
10500 /* If one pack has an expansion and another pack has a normal
10501 argument or if one pack has an empty argument and an another
10502 one hasn't then tsubst_pack_expansion cannot perform the
10503 substitution and need to fall back on the
10504 PACK_EXPANSION_EXTRA mechanism. */
10505 if (parm_packs == NULL_TREE)
10507 else if (has_empty_arg)
10510 bool has_expansion_arg = false;
10511 for (int i = 0 ; i < arg_pack_len; ++i)
10513 bool has_non_expansion_arg = false;
10514 for (tree parm_pack = parm_packs;
10516 parm_pack = TREE_CHAIN (parm_pack))
10518 tree arg = TREE_VALUE (parm_pack);
10520 int exp = argument_pack_element_is_expansion_p (arg, i);
10522 /* We can't substitute a pack expansion with extra args into
10526 has_expansion_arg = true;
10528 has_non_expansion_arg = true;
10531 if (has_expansion_arg && has_non_expansion_arg)
10537 /* [temp.variadic]/6 says that:
10539 The instantiation of a pack expansion [...]
10540 produces a list E1,E2, ..., En, where N is the number of elements
10541 in the pack expansion parameters.
10543 This subroutine of tsubst_pack_expansion produces one of these Ei.
10545 PATTERN is the pattern of the pack expansion. PARM_PACKS is a
10546 TREE_LIST in which each TREE_PURPOSE is a parameter pack of
10547 PATTERN, and each TREE_VALUE is its corresponding argument pack.
10548 INDEX is the index 'i' of the element Ei to produce. ARGS,
10549 COMPLAIN, and IN_DECL are the same parameters as for the
10550 tsubst_pack_expansion function.
10552 The function returns the resulting Ei upon successful completion,
10553 or error_mark_node.
10555 Note that this function possibly modifies the ARGS parameter, so
10556 it's the responsibility of the caller to restore it. */
10559 gen_elem_of_pack_expansion_instantiation (tree pattern,
10562 tree args /* This parm gets
10564 tsubst_flags_t complain,
10568 bool ith_elem_is_expansion = false;
10570 /* For each parameter pack, change the substitution of the parameter
10571 pack to the ith argument in its argument pack, then expand the
10573 for (tree pack = parm_packs; pack; pack = TREE_CHAIN (pack))
10575 tree parm = TREE_PURPOSE (pack);
10576 tree arg_pack = TREE_VALUE (pack);
10577 tree aps; /* instance of ARGUMENT_PACK_SELECT. */
10579 ith_elem_is_expansion |=
10580 argument_pack_element_is_expansion_p (arg_pack, index);
10582 /* Select the Ith argument from the pack. */
10583 if (TREE_CODE (parm) == PARM_DECL
10584 || TREE_CODE (parm) == FIELD_DECL)
10588 aps = make_argument_pack_select (arg_pack, index);
10589 if (!mark_used (parm, complain) && !(complain & tf_error))
10590 return error_mark_node;
10591 register_local_specialization (aps, parm);
10594 aps = retrieve_local_specialization (parm);
10599 template_parm_level_and_index (parm, &level, &idx);
10603 aps = make_argument_pack_select (arg_pack, index);
10604 /* Update the corresponding argument. */
10605 TMPL_ARG (args, level, idx) = aps;
10608 /* Re-use the ARGUMENT_PACK_SELECT. */
10609 aps = TMPL_ARG (args, level, idx);
10611 ARGUMENT_PACK_SELECT_INDEX (aps) = index;
10614 /* Substitute into the PATTERN with the (possibly altered)
10616 if (pattern == in_decl)
10617 /* Expanding a fixed parameter pack from
10618 coerce_template_parameter_pack. */
10619 t = tsubst_decl (pattern, args, complain);
10620 else if (pattern == error_mark_node)
10621 t = error_mark_node;
10622 else if (constraint_p (pattern))
10624 if (processing_template_decl)
10625 t = tsubst_constraint (pattern, args, complain, in_decl);
10627 t = (constraints_satisfied_p (pattern, args)
10628 ? boolean_true_node : boolean_false_node);
10630 else if (!TYPE_P (pattern))
10631 t = tsubst_expr (pattern, args, complain, in_decl,
10632 /*integral_constant_expression_p=*/false);
10634 t = tsubst (pattern, args, complain, in_decl);
10636 /* If the Ith argument pack element is a pack expansion, then
10637 the Ith element resulting from the substituting is going to
10638 be a pack expansion as well. */
10639 if (ith_elem_is_expansion)
10640 t = make_pack_expansion (t);
10645 /* When the unexpanded parameter pack in a fold expression expands to an empty
10646 sequence, the value of the expression is as follows; the program is
10647 ill-formed if the operator is not listed in this table.
10654 expand_empty_fold (tree t, tsubst_flags_t complain)
10656 tree_code code = (tree_code)TREE_INT_CST_LOW (TREE_OPERAND (t, 0));
10657 if (!FOLD_EXPR_MODIFY_P (t))
10660 case TRUTH_ANDIF_EXPR:
10661 return boolean_true_node;
10662 case TRUTH_ORIF_EXPR:
10663 return boolean_false_node;
10664 case COMPOUND_EXPR:
10670 if (complain & tf_error)
10671 error_at (location_of (t),
10672 "fold of empty expansion over %O", code);
10673 return error_mark_node;
10676 /* Given a fold-expression T and a current LEFT and RIGHT operand,
10677 form an expression that combines the two terms using the
10681 fold_expression (tree t, tree left, tree right, tsubst_flags_t complain)
10683 tree op = FOLD_EXPR_OP (t);
10684 tree_code code = (tree_code)TREE_INT_CST_LOW (op);
10686 // Handle compound assignment operators.
10687 if (FOLD_EXPR_MODIFY_P (t))
10688 return build_x_modify_expr (input_location, left, code, right, complain);
10692 case COMPOUND_EXPR:
10693 return build_x_compound_expr (input_location, left, right, complain);
10695 return build_m_component_ref (left, right, complain);
10697 return build_x_binary_op (input_location, code,
10698 left, TREE_CODE (left),
10699 right, TREE_CODE (right),
10705 /* Substitute ARGS into the pack of a fold expression T. */
10708 tsubst_fold_expr_pack (tree t, tree args, tsubst_flags_t complain, tree in_decl)
10710 return tsubst_pack_expansion (FOLD_EXPR_PACK (t), args, complain, in_decl);
10713 /* Substitute ARGS into the pack of a fold expression T. */
10716 tsubst_fold_expr_init (tree t, tree args, tsubst_flags_t complain, tree in_decl)
10718 return tsubst_expr (FOLD_EXPR_INIT (t), args, complain, in_decl, false);
10721 /* Expand a PACK of arguments into a grouped as left fold.
10722 Given a pack containing elements A0, A1, ..., An and an
10723 operator @, this builds the expression:
10725 ((A0 @ A1) @ A2) ... @ An
10727 Note that PACK must not be empty.
10729 The operator is defined by the original fold expression T. */
10732 expand_left_fold (tree t, tree pack, tsubst_flags_t complain)
10734 tree left = TREE_VEC_ELT (pack, 0);
10735 for (int i = 1; i < TREE_VEC_LENGTH (pack); ++i)
10737 tree right = TREE_VEC_ELT (pack, i);
10738 left = fold_expression (t, left, right, complain);
10743 /* Substitute into a unary left fold expression. */
10746 tsubst_unary_left_fold (tree t, tree args, tsubst_flags_t complain,
10749 tree pack = tsubst_fold_expr_pack (t, args, complain, in_decl);
10750 if (pack == error_mark_node)
10751 return error_mark_node;
10752 if (PACK_EXPANSION_P (pack))
10754 tree r = copy_node (t);
10755 FOLD_EXPR_PACK (r) = pack;
10758 if (TREE_VEC_LENGTH (pack) == 0)
10759 return expand_empty_fold (t, complain);
10761 return expand_left_fold (t, pack, complain);
10764 /* Substitute into a binary left fold expression.
10766 Do ths by building a single (non-empty) vector of argumnts and
10767 building the expression from those elements. */
10770 tsubst_binary_left_fold (tree t, tree args, tsubst_flags_t complain,
10773 tree pack = tsubst_fold_expr_pack (t, args, complain, in_decl);
10774 if (pack == error_mark_node)
10775 return error_mark_node;
10776 tree init = tsubst_fold_expr_init (t, args, complain, in_decl);
10777 if (init == error_mark_node)
10778 return error_mark_node;
10780 if (PACK_EXPANSION_P (pack))
10782 tree r = copy_node (t);
10783 FOLD_EXPR_PACK (r) = pack;
10784 FOLD_EXPR_INIT (r) = init;
10788 tree vec = make_tree_vec (TREE_VEC_LENGTH (pack) + 1);
10789 TREE_VEC_ELT (vec, 0) = init;
10790 for (int i = 0; i < TREE_VEC_LENGTH (pack); ++i)
10791 TREE_VEC_ELT (vec, i + 1) = TREE_VEC_ELT (pack, i);
10793 return expand_left_fold (t, vec, complain);
10796 /* Expand a PACK of arguments into a grouped as right fold.
10797 Given a pack containing elementns A0, A1, ..., and an
10798 operator @, this builds the expression:
10800 A0@ ... (An-2 @ (An-1 @ An))
10802 Note that PACK must not be empty.
10804 The operator is defined by the original fold expression T. */
10807 expand_right_fold (tree t, tree pack, tsubst_flags_t complain)
10809 // Build the expression.
10810 int n = TREE_VEC_LENGTH (pack);
10811 tree right = TREE_VEC_ELT (pack, n - 1);
10812 for (--n; n != 0; --n)
10814 tree left = TREE_VEC_ELT (pack, n - 1);
10815 right = fold_expression (t, left, right, complain);
10820 /* Substitute into a unary right fold expression. */
10823 tsubst_unary_right_fold (tree t, tree args, tsubst_flags_t complain,
10826 tree pack = tsubst_fold_expr_pack (t, args, complain, in_decl);
10827 if (pack == error_mark_node)
10828 return error_mark_node;
10829 if (PACK_EXPANSION_P (pack))
10831 tree r = copy_node (t);
10832 FOLD_EXPR_PACK (r) = pack;
10835 if (TREE_VEC_LENGTH (pack) == 0)
10836 return expand_empty_fold (t, complain);
10838 return expand_right_fold (t, pack, complain);
10841 /* Substitute into a binary right fold expression.
10843 Do ths by building a single (non-empty) vector of arguments and
10844 building the expression from those elements. */
10847 tsubst_binary_right_fold (tree t, tree args, tsubst_flags_t complain,
10850 tree pack = tsubst_fold_expr_pack (t, args, complain, in_decl);
10851 if (pack == error_mark_node)
10852 return error_mark_node;
10853 tree init = tsubst_fold_expr_init (t, args, complain, in_decl);
10854 if (init == error_mark_node)
10855 return error_mark_node;
10857 if (PACK_EXPANSION_P (pack))
10859 tree r = copy_node (t);
10860 FOLD_EXPR_PACK (r) = pack;
10861 FOLD_EXPR_INIT (r) = init;
10865 int n = TREE_VEC_LENGTH (pack);
10866 tree vec = make_tree_vec (n + 1);
10867 for (int i = 0; i < n; ++i)
10868 TREE_VEC_ELT (vec, i) = TREE_VEC_ELT (pack, i);
10869 TREE_VEC_ELT (vec, n) = init;
10871 return expand_right_fold (t, vec, complain);
10875 /* Substitute ARGS into T, which is an pack expansion
10876 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
10877 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
10878 (if only a partial substitution could be performed) or
10879 ERROR_MARK_NODE if there was an error. */
10881 tsubst_pack_expansion (tree t, tree args, tsubst_flags_t complain,
10885 tree pack, packs = NULL_TREE;
10886 bool unsubstituted_packs = false;
10889 hash_map<tree, tree> *saved_local_specializations = NULL;
10890 bool need_local_specializations = false;
10893 gcc_assert (PACK_EXPANSION_P (t));
10894 pattern = PACK_EXPANSION_PATTERN (t);
10896 /* Add in any args remembered from an earlier partial instantiation. */
10897 args = add_to_template_args (PACK_EXPANSION_EXTRA_ARGS (t), args);
10899 levels = TMPL_ARGS_DEPTH (args);
10901 /* Determine the argument packs that will instantiate the parameter
10902 packs used in the expansion expression. While we're at it,
10903 compute the number of arguments to be expanded and make sure it
10905 for (pack = PACK_EXPANSION_PARAMETER_PACKS (t); pack;
10906 pack = TREE_CHAIN (pack))
10908 tree parm_pack = TREE_VALUE (pack);
10909 tree arg_pack = NULL_TREE;
10910 tree orig_arg = NULL_TREE;
10913 if (TREE_CODE (parm_pack) == BASES)
10915 if (BASES_DIRECT (parm_pack))
10916 return calculate_direct_bases (tsubst_expr (BASES_TYPE (parm_pack),
10917 args, complain, in_decl, false));
10919 return calculate_bases (tsubst_expr (BASES_TYPE (parm_pack),
10920 args, complain, in_decl, false));
10922 if (TREE_CODE (parm_pack) == PARM_DECL)
10924 /* We know we have correct local_specializations if this
10925 expansion is at function scope, or if we're dealing with a
10926 local parameter in a requires expression; for the latter,
10927 tsubst_requires_expr set it up appropriately. */
10928 if (PACK_EXPANSION_LOCAL_P (t) || CONSTRAINT_VAR_P (parm_pack))
10929 arg_pack = retrieve_local_specialization (parm_pack);
10931 /* We can't rely on local_specializations for a parameter
10932 name used later in a function declaration (such as in a
10933 late-specified return type). Even if it exists, it might
10934 have the wrong value for a recursive call. */
10935 need_local_specializations = true;
10939 /* This parameter pack was used in an unevaluated context. Just
10940 make a dummy decl, since it's only used for its type. */
10941 arg_pack = tsubst_decl (parm_pack, args, complain);
10942 if (arg_pack && DECL_PACK_P (arg_pack))
10943 /* Partial instantiation of the parm_pack, we can't build
10944 up an argument pack yet. */
10945 arg_pack = NULL_TREE;
10947 arg_pack = make_fnparm_pack (arg_pack);
10950 else if (TREE_CODE (parm_pack) == FIELD_DECL)
10951 arg_pack = tsubst_copy (parm_pack, args, complain, in_decl);
10955 template_parm_level_and_index (parm_pack, &level, &idx);
10957 if (level <= levels)
10958 arg_pack = TMPL_ARG (args, level, idx);
10961 orig_arg = arg_pack;
10962 if (arg_pack && TREE_CODE (arg_pack) == ARGUMENT_PACK_SELECT)
10963 arg_pack = ARGUMENT_PACK_SELECT_FROM_PACK (arg_pack);
10965 if (arg_pack && !ARGUMENT_PACK_P (arg_pack))
10966 /* This can only happen if we forget to expand an argument
10967 pack somewhere else. Just return an error, silently. */
10969 result = make_tree_vec (1);
10970 TREE_VEC_ELT (result, 0) = error_mark_node;
10977 TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack));
10979 /* Don't bother trying to do a partial substitution with
10980 incomplete packs; we'll try again after deduction. */
10981 if (ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
10986 else if (len != my_len)
10988 if (!(complain & tf_error))
10989 /* Fail quietly. */;
10990 else if (TREE_CODE (t) == TYPE_PACK_EXPANSION)
10991 error ("mismatched argument pack lengths while expanding "
10995 error ("mismatched argument pack lengths while expanding "
10998 return error_mark_node;
11001 /* Keep track of the parameter packs and their corresponding
11003 packs = tree_cons (parm_pack, arg_pack, packs);
11004 TREE_TYPE (packs) = orig_arg;
11008 /* We can't substitute for this parameter pack. We use a flag as
11009 well as the missing_level counter because function parameter
11010 packs don't have a level. */
11011 unsubstituted_packs = true;
11015 /* If the expansion is just T..., return the matching argument pack, unless
11016 we need to call convert_from_reference on all the elements. This is an
11017 important optimization; see c++/68422. */
11018 if (!unsubstituted_packs
11019 && TREE_PURPOSE (packs) == pattern)
11021 tree args = ARGUMENT_PACK_ARGS (TREE_VALUE (packs));
11022 /* Types need no adjustment, nor does sizeof..., and if we still have
11023 some pack expansion args we won't do anything yet. */
11024 if (TREE_CODE (t) == TYPE_PACK_EXPANSION
11025 || PACK_EXPANSION_SIZEOF_P (t)
11026 || pack_expansion_args_count (args))
11028 /* Also optimize expression pack expansions if we can tell that the
11029 elements won't have reference type. */
11030 tree type = TREE_TYPE (pattern);
11031 if (type && TREE_CODE (type) != REFERENCE_TYPE
11032 && !PACK_EXPANSION_P (type)
11033 && !WILDCARD_TYPE_P (type))
11035 /* Otherwise use the normal path so we get convert_from_reference. */
11038 /* We cannot expand this expansion expression, because we don't have
11039 all of the argument packs we need. */
11040 if (use_pack_expansion_extra_args_p (packs, len, unsubstituted_packs))
11042 /* We got some full packs, but we can't substitute them in until we
11043 have values for all the packs. So remember these until then. */
11045 t = make_pack_expansion (pattern);
11046 PACK_EXPANSION_EXTRA_ARGS (t) = args;
11049 else if (unsubstituted_packs)
11051 /* There were no real arguments, we're just replacing a parameter
11052 pack with another version of itself. Substitute into the
11053 pattern and return a PACK_EXPANSION_*. The caller will need to
11055 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
11056 t = tsubst_expr (pattern, args, complain, in_decl,
11057 /*integral_constant_expression_p=*/false);
11059 t = tsubst (pattern, args, complain, in_decl);
11060 t = make_pack_expansion (t);
11064 gcc_assert (len >= 0);
11066 if (need_local_specializations)
11068 /* We're in a late-specified return type, so create our own local
11069 specializations map; the current map is either NULL or (in the
11070 case of recursive unification) might have bindings that we don't
11071 want to use or alter. */
11072 saved_local_specializations = local_specializations;
11073 local_specializations = new hash_map<tree, tree>;
11076 /* For each argument in each argument pack, substitute into the
11078 result = make_tree_vec (len);
11079 tree elem_args = copy_template_args (args);
11080 for (i = 0; i < len; ++i)
11082 t = gen_elem_of_pack_expansion_instantiation (pattern, packs,
11084 elem_args, complain,
11086 TREE_VEC_ELT (result, i) = t;
11087 if (t == error_mark_node)
11089 result = error_mark_node;
11094 /* Update ARGS to restore the substitution from parameter packs to
11095 their argument packs. */
11096 for (pack = packs; pack; pack = TREE_CHAIN (pack))
11098 tree parm = TREE_PURPOSE (pack);
11100 if (TREE_CODE (parm) == PARM_DECL
11101 || TREE_CODE (parm) == FIELD_DECL)
11102 register_local_specialization (TREE_TYPE (pack), parm);
11107 if (TREE_VALUE (pack) == NULL_TREE)
11110 template_parm_level_and_index (parm, &level, &idx);
11112 /* Update the corresponding argument. */
11113 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
11114 TREE_VEC_ELT (TREE_VEC_ELT (args, level -1 ), idx) =
11117 TREE_VEC_ELT (args, idx) = TREE_TYPE (pack);
11121 if (need_local_specializations)
11123 delete local_specializations;
11124 local_specializations = saved_local_specializations;
11127 /* If the dependent pack arguments were such that we end up with only a
11128 single pack expansion again, there's no need to keep it in a TREE_VEC. */
11129 if (len == 1 && TREE_CODE (result) == TREE_VEC
11130 && PACK_EXPANSION_P (TREE_VEC_ELT (result, 0)))
11131 return TREE_VEC_ELT (result, 0);
11136 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
11137 TMPL. We do this using DECL_PARM_INDEX, which should work even with
11138 parameter packs; all parms generated from a function parameter pack will
11139 have the same DECL_PARM_INDEX. */
11142 get_pattern_parm (tree parm, tree tmpl)
11144 tree pattern = DECL_TEMPLATE_RESULT (tmpl);
11147 if (DECL_ARTIFICIAL (parm))
11149 for (patparm = DECL_ARGUMENTS (pattern);
11150 patparm; patparm = DECL_CHAIN (patparm))
11151 if (DECL_ARTIFICIAL (patparm)
11152 && DECL_NAME (parm) == DECL_NAME (patparm))
11157 patparm = FUNCTION_FIRST_USER_PARM (DECL_TEMPLATE_RESULT (tmpl));
11158 patparm = chain_index (DECL_PARM_INDEX (parm)-1, patparm);
11159 gcc_assert (DECL_PARM_INDEX (patparm)
11160 == DECL_PARM_INDEX (parm));
11166 /* Make an argument pack out of the TREE_VEC VEC. */
11169 make_argument_pack (tree vec)
11172 tree elt = TREE_VEC_ELT (vec, 0);
11174 pack = cxx_make_type (TYPE_ARGUMENT_PACK);
11177 pack = make_node (NONTYPE_ARGUMENT_PACK);
11178 TREE_TYPE (pack) = TREE_TYPE (elt);
11179 TREE_CONSTANT (pack) = 1;
11181 SET_ARGUMENT_PACK_ARGS (pack, vec);
11185 /* Return an exact copy of template args T that can be modified
11189 copy_template_args (tree t)
11191 if (t == error_mark_node)
11194 int len = TREE_VEC_LENGTH (t);
11195 tree new_vec = make_tree_vec (len);
11197 for (int i = 0; i < len; ++i)
11199 tree elt = TREE_VEC_ELT (t, i);
11200 if (elt && TREE_CODE (elt) == TREE_VEC)
11201 elt = copy_template_args (elt);
11202 TREE_VEC_ELT (new_vec, i) = elt;
11205 NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_vec)
11206 = NON_DEFAULT_TEMPLATE_ARGS_COUNT (t);
11211 /* Substitute ARGS into the vector or list of template arguments T. */
11214 tsubst_template_args (tree t, tree args, tsubst_flags_t complain, tree in_decl)
11217 int len, need_new = 0, i, expanded_len_adjust = 0, out;
11220 if (t == error_mark_node)
11221 return error_mark_node;
11223 len = TREE_VEC_LENGTH (t);
11224 elts = XALLOCAVEC (tree, len);
11226 for (i = 0; i < len; i++)
11228 tree orig_arg = TREE_VEC_ELT (t, i);
11231 if (TREE_CODE (orig_arg) == TREE_VEC)
11232 new_arg = tsubst_template_args (orig_arg, args, complain, in_decl);
11233 else if (PACK_EXPANSION_P (orig_arg))
11235 /* Substitute into an expansion expression. */
11236 new_arg = tsubst_pack_expansion (orig_arg, args, complain, in_decl);
11238 if (TREE_CODE (new_arg) == TREE_VEC)
11239 /* Add to the expanded length adjustment the number of
11240 expanded arguments. We subtract one from this
11241 measurement, because the argument pack expression
11242 itself is already counted as 1 in
11243 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
11244 the argument pack is empty. */
11245 expanded_len_adjust += TREE_VEC_LENGTH (new_arg) - 1;
11247 else if (ARGUMENT_PACK_P (orig_arg))
11249 /* Substitute into each of the arguments. */
11250 new_arg = TYPE_P (orig_arg)
11251 ? cxx_make_type (TREE_CODE (orig_arg))
11252 : make_node (TREE_CODE (orig_arg));
11254 SET_ARGUMENT_PACK_ARGS (
11256 tsubst_template_args (ARGUMENT_PACK_ARGS (orig_arg),
11257 args, complain, in_decl));
11259 if (ARGUMENT_PACK_ARGS (new_arg) == error_mark_node)
11260 new_arg = error_mark_node;
11262 if (TREE_CODE (new_arg) == NONTYPE_ARGUMENT_PACK) {
11263 TREE_TYPE (new_arg) = tsubst (TREE_TYPE (orig_arg), args,
11264 complain, in_decl);
11265 TREE_CONSTANT (new_arg) = TREE_CONSTANT (orig_arg);
11267 if (TREE_TYPE (new_arg) == error_mark_node)
11268 new_arg = error_mark_node;
11272 new_arg = tsubst_template_arg (orig_arg, args, complain, in_decl);
11274 if (new_arg == error_mark_node)
11275 return error_mark_node;
11278 if (new_arg != orig_arg)
11285 /* Make space for the expanded arguments coming from template
11287 t = make_tree_vec (len + expanded_len_adjust);
11288 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
11289 arguments for a member template.
11290 In that case each TREE_VEC in ORIG_T represents a level of template
11291 arguments, and ORIG_T won't carry any non defaulted argument count.
11292 It will rather be the nested TREE_VECs that will carry one.
11293 In other words, ORIG_T carries a non defaulted argument count only
11294 if it doesn't contain any nested TREE_VEC. */
11295 if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t))
11297 int count = GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t);
11298 count += expanded_len_adjust;
11299 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (t, count);
11301 for (i = 0, out = 0; i < len; i++)
11303 if ((PACK_EXPANSION_P (TREE_VEC_ELT (orig_t, i))
11304 || ARGUMENT_PACK_P (TREE_VEC_ELT (orig_t, i)))
11305 && TREE_CODE (elts[i]) == TREE_VEC)
11309 /* Now expand the template argument pack "in place". */
11310 for (idx = 0; idx < TREE_VEC_LENGTH (elts[i]); idx++, out++)
11311 TREE_VEC_ELT (t, out) = TREE_VEC_ELT (elts[i], idx);
11315 TREE_VEC_ELT (t, out) = elts[i];
11323 /* Return the result of substituting ARGS into the template parameters
11324 given by PARMS. If there are m levels of ARGS and m + n levels of
11325 PARMS, then the result will contain n levels of PARMS. For
11326 example, if PARMS is `template <class T> template <class U>
11327 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
11328 result will be `template <int*, double, class V>'. */
11331 tsubst_template_parms (tree parms, tree args, tsubst_flags_t complain)
11333 tree r = NULL_TREE;
11336 /* When substituting into a template, we must set
11337 PROCESSING_TEMPLATE_DECL as the template parameters may be
11338 dependent if they are based on one-another, and the dependency
11339 predicates are short-circuit outside of templates. */
11340 ++processing_template_decl;
11342 for (new_parms = &r;
11343 parms && TMPL_PARMS_DEPTH (parms) > TMPL_ARGS_DEPTH (args);
11344 new_parms = &(TREE_CHAIN (*new_parms)),
11345 parms = TREE_CHAIN (parms))
11348 make_tree_vec (TREE_VEC_LENGTH (TREE_VALUE (parms)));
11351 for (i = 0; i < TREE_VEC_LENGTH (new_vec); ++i)
11355 if (parms == error_mark_node)
11358 tuple = TREE_VEC_ELT (TREE_VALUE (parms), i);
11360 if (tuple == error_mark_node)
11363 TREE_VEC_ELT (new_vec, i) =
11364 tsubst_template_parm (tuple, args, complain);
11368 tree_cons (size_int (TMPL_PARMS_DEPTH (parms)
11369 - TMPL_ARGS_DEPTH (args)),
11370 new_vec, NULL_TREE);
11373 --processing_template_decl;
11378 /* Return the result of substituting ARGS into one template parameter
11379 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
11380 parameter and which TREE_PURPOSE is the default argument of the
11381 template parameter. */
11384 tsubst_template_parm (tree t, tree args, tsubst_flags_t complain)
11386 tree default_value, parm_decl;
11388 if (args == NULL_TREE
11390 || t == error_mark_node)
11393 gcc_assert (TREE_CODE (t) == TREE_LIST);
11395 default_value = TREE_PURPOSE (t);
11396 parm_decl = TREE_VALUE (t);
11398 parm_decl = tsubst (parm_decl, args, complain, NULL_TREE);
11399 if (TREE_CODE (parm_decl) == PARM_DECL
11400 && invalid_nontype_parm_type_p (TREE_TYPE (parm_decl), complain))
11401 parm_decl = error_mark_node;
11402 default_value = tsubst_template_arg (default_value, args,
11403 complain, NULL_TREE);
11405 return build_tree_list (default_value, parm_decl);
11408 /* Substitute the ARGS into the indicated aggregate (or enumeration)
11409 type T. If T is not an aggregate or enumeration type, it is
11410 handled as if by tsubst. IN_DECL is as for tsubst. If
11411 ENTERING_SCOPE is nonzero, T is the context for a template which
11412 we are presently tsubst'ing. Return the substituted value. */
11415 tsubst_aggr_type (tree t,
11417 tsubst_flags_t complain,
11419 int entering_scope)
11421 if (t == NULL_TREE)
11424 switch (TREE_CODE (t))
11427 if (TYPE_PTRMEMFUNC_P (t))
11428 return tsubst (TYPE_PTRMEMFUNC_FN_TYPE (t), args, complain, in_decl);
11430 /* Else fall through. */
11431 case ENUMERAL_TYPE:
11433 if (TYPE_TEMPLATE_INFO (t) && uses_template_parms (t))
11438 int saved_unevaluated_operand;
11439 int saved_inhibit_evaluation_warnings;
11441 /* In "sizeof(X<I>)" we need to evaluate "I". */
11442 saved_unevaluated_operand = cp_unevaluated_operand;
11443 cp_unevaluated_operand = 0;
11444 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
11445 c_inhibit_evaluation_warnings = 0;
11447 /* First, determine the context for the type we are looking
11449 context = TYPE_CONTEXT (t);
11450 if (context && TYPE_P (context))
11452 context = tsubst_aggr_type (context, args, complain,
11453 in_decl, /*entering_scope=*/1);
11454 /* If context is a nested class inside a class template,
11455 it may still need to be instantiated (c++/33959). */
11456 context = complete_type (context);
11459 /* Then, figure out what arguments are appropriate for the
11460 type we are trying to find. For example, given:
11462 template <class T> struct S;
11463 template <class T, class U> void f(T, U) { S<U> su; }
11465 and supposing that we are instantiating f<int, double>,
11466 then our ARGS will be {int, double}, but, when looking up
11467 S we only want {double}. */
11468 argvec = tsubst_template_args (TYPE_TI_ARGS (t), args,
11469 complain, in_decl);
11470 if (argvec == error_mark_node)
11471 r = error_mark_node;
11474 r = lookup_template_class (t, argvec, in_decl, context,
11475 entering_scope, complain);
11476 r = cp_build_qualified_type_real (r, cp_type_quals (t), complain);
11479 cp_unevaluated_operand = saved_unevaluated_operand;
11480 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
11485 /* This is not a template type, so there's nothing to do. */
11489 return tsubst (t, args, complain, in_decl);
11493 /* Substitute into the default argument ARG (a default argument for
11494 FN), which has the indicated TYPE. */
11497 tsubst_default_argument (tree fn, tree type, tree arg, tsubst_flags_t complain)
11499 tree saved_class_ptr = NULL_TREE;
11500 tree saved_class_ref = NULL_TREE;
11501 int errs = errorcount + sorrycount;
11503 /* This can happen in invalid code. */
11504 if (TREE_CODE (arg) == DEFAULT_ARG)
11507 /* This default argument came from a template. Instantiate the
11508 default argument here, not in tsubst. In the case of
11517 we must be careful to do name lookup in the scope of S<T>,
11518 rather than in the current class. */
11519 push_access_scope (fn);
11520 /* The "this" pointer is not valid in a default argument. */
11523 saved_class_ptr = current_class_ptr;
11524 cp_function_chain->x_current_class_ptr = NULL_TREE;
11525 saved_class_ref = current_class_ref;
11526 cp_function_chain->x_current_class_ref = NULL_TREE;
11529 push_deferring_access_checks(dk_no_deferred);
11530 /* The default argument expression may cause implicitly defined
11531 member functions to be synthesized, which will result in garbage
11532 collection. We must treat this situation as if we were within
11533 the body of function so as to avoid collecting live data on the
11536 arg = tsubst_expr (arg, DECL_TI_ARGS (fn),
11537 complain, NULL_TREE,
11538 /*integral_constant_expression_p=*/false);
11540 pop_deferring_access_checks();
11542 /* Restore the "this" pointer. */
11545 cp_function_chain->x_current_class_ptr = saved_class_ptr;
11546 cp_function_chain->x_current_class_ref = saved_class_ref;
11549 if (errorcount+sorrycount > errs
11550 && (complain & tf_warning_or_error))
11551 inform (input_location,
11552 " when instantiating default argument for call to %D", fn);
11554 /* Make sure the default argument is reasonable. */
11555 arg = check_default_argument (type, arg, complain);
11557 pop_access_scope (fn);
11562 /* Substitute into all the default arguments for FN. */
11565 tsubst_default_arguments (tree fn, tsubst_flags_t complain)
11570 tmpl_args = DECL_TI_ARGS (fn);
11572 /* If this function is not yet instantiated, we certainly don't need
11573 its default arguments. */
11574 if (uses_template_parms (tmpl_args))
11576 /* Don't do this again for clones. */
11577 if (DECL_CLONED_FUNCTION_P (fn))
11580 for (arg = TYPE_ARG_TYPES (TREE_TYPE (fn));
11582 arg = TREE_CHAIN (arg))
11583 if (TREE_PURPOSE (arg))
11584 TREE_PURPOSE (arg) = tsubst_default_argument (fn,
11586 TREE_PURPOSE (arg),
11590 /* Substitute the ARGS into the T, which is a _DECL. Return the
11591 result of the substitution. Issue error and warning messages under
11592 control of COMPLAIN. */
11595 tsubst_decl (tree t, tree args, tsubst_flags_t complain)
11597 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
11598 location_t saved_loc;
11599 tree r = NULL_TREE;
11601 hashval_t hash = 0;
11603 /* Set the filename and linenumber to improve error-reporting. */
11604 saved_loc = input_location;
11605 input_location = DECL_SOURCE_LOCATION (t);
11607 switch (TREE_CODE (t))
11609 case TEMPLATE_DECL:
11611 /* We can get here when processing a member function template,
11612 member class template, or template template parameter. */
11613 tree decl = DECL_TEMPLATE_RESULT (t);
11618 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
11620 /* Template template parameter is treated here. */
11621 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
11622 if (new_type == error_mark_node)
11623 r = error_mark_node;
11624 /* If we get a real template back, return it. This can happen in
11625 the context of most_specialized_partial_spec. */
11626 else if (TREE_CODE (new_type) == TEMPLATE_DECL)
11629 /* The new TEMPLATE_DECL was built in
11630 reduce_template_parm_level. */
11631 r = TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (new_type);
11635 /* We might already have an instance of this template.
11636 The ARGS are for the surrounding class type, so the
11637 full args contain the tsubst'd args for the context,
11638 plus the innermost args from the template decl. */
11639 tmpl_args = DECL_CLASS_TEMPLATE_P (t)
11640 ? CLASSTYPE_TI_ARGS (TREE_TYPE (t))
11641 : DECL_TI_ARGS (DECL_TEMPLATE_RESULT (t));
11642 /* Because this is a template, the arguments will still be
11643 dependent, even after substitution. If
11644 PROCESSING_TEMPLATE_DECL is not set, the dependency
11645 predicates will short-circuit. */
11646 ++processing_template_decl;
11647 full_args = tsubst_template_args (tmpl_args, args,
11648 complain, in_decl);
11649 --processing_template_decl;
11650 if (full_args == error_mark_node)
11651 RETURN (error_mark_node);
11653 /* If this is a default template template argument,
11654 tsubst might not have changed anything. */
11655 if (full_args == tmpl_args)
11658 hash = hash_tmpl_and_args (t, full_args);
11659 spec = retrieve_specialization (t, full_args, hash);
11660 if (spec != NULL_TREE)
11666 /* Make a new template decl. It will be similar to the
11667 original, but will record the current template arguments.
11668 We also create a new function declaration, which is just
11669 like the old one, but points to this new template, rather
11670 than the old one. */
11672 gcc_assert (DECL_LANG_SPECIFIC (r) != 0);
11673 DECL_CHAIN (r) = NULL_TREE;
11675 // Build new template info linking to the original template decl.
11676 DECL_TEMPLATE_INFO (r) = build_template_info (t, args);
11678 if (TREE_CODE (decl) == TYPE_DECL
11679 && !TYPE_DECL_ALIAS_P (decl))
11682 ++processing_template_decl;
11683 new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
11684 --processing_template_decl;
11685 if (new_type == error_mark_node)
11686 RETURN (error_mark_node);
11688 TREE_TYPE (r) = new_type;
11689 /* For a partial specialization, we need to keep pointing to
11690 the primary template. */
11691 if (!DECL_TEMPLATE_SPECIALIZATION (t))
11692 CLASSTYPE_TI_TEMPLATE (new_type) = r;
11693 DECL_TEMPLATE_RESULT (r) = TYPE_MAIN_DECL (new_type);
11694 DECL_TI_ARGS (r) = CLASSTYPE_TI_ARGS (new_type);
11695 DECL_CONTEXT (r) = TYPE_CONTEXT (new_type);
11700 ++processing_template_decl;
11701 new_decl = tsubst (decl, args, complain, in_decl);
11702 --processing_template_decl;
11703 if (new_decl == error_mark_node)
11704 RETURN (error_mark_node);
11706 DECL_TEMPLATE_RESULT (r) = new_decl;
11707 DECL_TI_TEMPLATE (new_decl) = r;
11708 TREE_TYPE (r) = TREE_TYPE (new_decl);
11709 DECL_TI_ARGS (r) = DECL_TI_ARGS (new_decl);
11710 DECL_CONTEXT (r) = DECL_CONTEXT (new_decl);
11713 SET_DECL_IMPLICIT_INSTANTIATION (r);
11714 DECL_TEMPLATE_INSTANTIATIONS (r) = NULL_TREE;
11715 DECL_TEMPLATE_SPECIALIZATIONS (r) = NULL_TREE;
11717 /* The template parameters for this new template are all the
11718 template parameters for the old template, except the
11719 outermost level of parameters. */
11720 DECL_TEMPLATE_PARMS (r)
11721 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
11724 if (PRIMARY_TEMPLATE_P (t))
11725 DECL_PRIMARY_TEMPLATE (r) = r;
11727 if (TREE_CODE (decl) != TYPE_DECL && !VAR_P (decl))
11728 /* Record this non-type partial instantiation. */
11729 register_specialization (r, t,
11730 DECL_TI_ARGS (DECL_TEMPLATE_RESULT (r)),
11735 case FUNCTION_DECL:
11738 tree argvec = NULL_TREE;
11746 /* Nobody should be tsubst'ing into non-template functions. */
11747 gcc_assert (DECL_TEMPLATE_INFO (t) != NULL_TREE);
11749 if (TREE_CODE (DECL_TI_TEMPLATE (t)) == TEMPLATE_DECL)
11754 /* If T is not dependent, just return it. We have to
11755 increment PROCESSING_TEMPLATE_DECL because
11756 value_dependent_expression_p assumes that nothing is
11757 dependent when PROCESSING_TEMPLATE_DECL is zero. */
11758 ++processing_template_decl;
11759 dependent_p = value_dependent_expression_p (t);
11760 --processing_template_decl;
11764 /* Calculate the most general template of which R is a
11765 specialization, and the complete set of arguments used to
11767 gen_tmpl = most_general_template (DECL_TI_TEMPLATE (t));
11768 argvec = tsubst_template_args (DECL_TI_ARGS
11769 (DECL_TEMPLATE_RESULT
11770 (DECL_TI_TEMPLATE (t))),
11771 args, complain, in_decl);
11772 if (argvec == error_mark_node)
11773 RETURN (error_mark_node);
11775 /* Check to see if we already have this specialization. */
11776 hash = hash_tmpl_and_args (gen_tmpl, argvec);
11777 spec = retrieve_specialization (gen_tmpl, argvec, hash);
11785 /* We can see more levels of arguments than parameters if
11786 there was a specialization of a member template, like
11789 template <class T> struct S { template <class U> void f(); }
11790 template <> template <class U> void S<int>::f(U);
11792 Here, we'll be substituting into the specialization,
11793 because that's where we can find the code we actually
11794 want to generate, but we'll have enough arguments for
11795 the most general template.
11797 We also deal with the peculiar case:
11799 template <class T> struct S {
11800 template <class U> friend void f();
11802 template <class U> void f() {}
11804 template void f<double>();
11806 Here, the ARGS for the instantiation of will be {int,
11807 double}. But, we only need as many ARGS as there are
11808 levels of template parameters in CODE_PATTERN. We are
11809 careful not to get fooled into reducing the ARGS in
11812 template <class T> struct S { template <class U> void f(U); }
11813 template <class T> template <> void S<T>::f(int) {}
11815 which we can spot because the pattern will be a
11816 specialization in this case. */
11817 args_depth = TMPL_ARGS_DEPTH (args);
11819 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (t)));
11820 if (args_depth > parms_depth
11821 && !DECL_TEMPLATE_SPECIALIZATION (t))
11822 args = get_innermost_template_args (args, parms_depth);
11826 /* This special case arises when we have something like this:
11828 template <class T> struct S {
11829 friend void f<int>(int, double);
11832 Here, the DECL_TI_TEMPLATE for the friend declaration
11833 will be an IDENTIFIER_NODE. We are being called from
11834 tsubst_friend_function, and we want only to create a
11835 new decl (R) with appropriate types so that we can call
11836 determine_specialization. */
11837 gen_tmpl = NULL_TREE;
11840 if (DECL_CLASS_SCOPE_P (t))
11842 if (DECL_NAME (t) == constructor_name (DECL_CONTEXT (t)))
11846 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args,
11847 complain, t, /*entering_scope=*/1);
11852 ctx = DECL_CONTEXT (t);
11854 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
11855 if (type == error_mark_node)
11856 RETURN (error_mark_node);
11858 /* If we hit excessive deduction depth, the type is bogus even if
11859 it isn't error_mark_node, so don't build a decl. */
11860 if (excessive_deduction_depth)
11861 RETURN (error_mark_node);
11863 /* We do NOT check for matching decls pushed separately at this
11864 point, as they may not represent instantiations of this
11865 template, and in any case are considered separate under the
11868 DECL_USE_TEMPLATE (r) = 0;
11869 TREE_TYPE (r) = type;
11870 /* Clear out the mangled name and RTL for the instantiation. */
11871 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
11872 SET_DECL_RTL (r, NULL);
11873 /* Leave DECL_INITIAL set on deleted instantiations. */
11874 if (!DECL_DELETED_FN (r))
11875 DECL_INITIAL (r) = NULL_TREE;
11876 DECL_CONTEXT (r) = ctx;
11878 /* OpenMP UDRs have the only argument a reference to the declared
11879 type. We want to diagnose if the declared type is a reference,
11880 which is invalid, but as references to references are usually
11881 quietly merged, diagnose it here. */
11882 if (DECL_OMP_DECLARE_REDUCTION_P (t))
11885 = TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (TREE_TYPE (t))));
11886 argtype = tsubst (argtype, args, complain, in_decl);
11887 if (TREE_CODE (argtype) == REFERENCE_TYPE)
11888 error_at (DECL_SOURCE_LOCATION (t),
11889 "reference type %qT in "
11890 "%<#pragma omp declare reduction%>", argtype);
11891 if (strchr (IDENTIFIER_POINTER (DECL_NAME (t)), '~') == NULL)
11892 DECL_NAME (r) = omp_reduction_id (ERROR_MARK, DECL_NAME (t),
11896 if (member && DECL_CONV_FN_P (r))
11897 /* Type-conversion operator. Reconstruct the name, in
11898 case it's the name of one of the template's parameters. */
11899 DECL_NAME (r) = mangle_conv_op_name_for_type (TREE_TYPE (type));
11901 DECL_ARGUMENTS (r) = tsubst (DECL_ARGUMENTS (t), args,
11903 DECL_RESULT (r) = NULL_TREE;
11905 TREE_STATIC (r) = 0;
11906 TREE_PUBLIC (r) = TREE_PUBLIC (t);
11907 DECL_EXTERNAL (r) = 1;
11908 /* If this is an instantiation of a function with internal
11909 linkage, we already know what object file linkage will be
11910 assigned to the instantiation. */
11911 DECL_INTERFACE_KNOWN (r) = !TREE_PUBLIC (r);
11912 DECL_DEFER_OUTPUT (r) = 0;
11913 DECL_CHAIN (r) = NULL_TREE;
11914 DECL_PENDING_INLINE_INFO (r) = 0;
11915 DECL_PENDING_INLINE_P (r) = 0;
11916 DECL_SAVED_TREE (r) = NULL_TREE;
11917 DECL_STRUCT_FUNCTION (r) = NULL;
11919 /* We'll re-clone as appropriate in instantiate_template. */
11920 DECL_CLONED_FUNCTION (r) = NULL_TREE;
11922 /* If we aren't complaining now, return on error before we register
11923 the specialization so that we'll complain eventually. */
11924 if ((complain & tf_error) == 0
11925 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
11926 && !grok_op_properties (r, /*complain=*/false))
11927 RETURN (error_mark_node);
11929 /* When instantiating a constrained member, substitute
11930 into the constraints to create a new constraint. */
11931 if (tree ci = get_constraints (t))
11934 ci = tsubst_constraint_info (ci, argvec, complain, NULL_TREE);
11935 set_constraints (r, ci);
11938 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
11939 this in the special friend case mentioned above where
11940 GEN_TMPL is NULL. */
11943 DECL_TEMPLATE_INFO (r)
11944 = build_template_info (gen_tmpl, argvec);
11945 SET_DECL_IMPLICIT_INSTANTIATION (r);
11948 = register_specialization (r, gen_tmpl, argvec, false, hash);
11950 /* We instantiated this while substituting into
11951 the type earlier (template/friend54.C). */
11954 /* We're not supposed to instantiate default arguments
11955 until they are called, for a template. But, for a
11958 template <class T> void f ()
11959 { extern void g(int i = T()); }
11961 we should do the substitution when the template is
11962 instantiated. We handle the member function case in
11963 instantiate_class_template since the default arguments
11964 might refer to other members of the class. */
11966 && !PRIMARY_TEMPLATE_P (gen_tmpl)
11967 && !uses_template_parms (argvec))
11968 tsubst_default_arguments (r, complain);
11971 DECL_TEMPLATE_INFO (r) = NULL_TREE;
11973 /* Copy the list of befriending classes. */
11974 for (friends = &DECL_BEFRIENDING_CLASSES (r);
11976 friends = &TREE_CHAIN (*friends))
11978 *friends = copy_node (*friends);
11979 TREE_VALUE (*friends) = tsubst (TREE_VALUE (*friends),
11984 if (DECL_CONSTRUCTOR_P (r) || DECL_DESTRUCTOR_P (r))
11986 maybe_retrofit_in_chrg (r);
11987 if (DECL_CONSTRUCTOR_P (r))
11988 grok_ctor_properties (ctx, r);
11989 if (DECL_INHERITED_CTOR_BASE (r))
11990 deduce_inheriting_ctor (r);
11991 /* If this is an instantiation of a member template, clone it.
11992 If it isn't, that'll be handled by
11993 clone_constructors_and_destructors. */
11994 if (PRIMARY_TEMPLATE_P (gen_tmpl))
11995 clone_function_decl (r, /*update_method_vec_p=*/0);
11997 else if ((complain & tf_error) != 0
11998 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
11999 && !grok_op_properties (r, /*complain=*/true))
12000 RETURN (error_mark_node);
12002 if (DECL_FRIEND_P (t) && DECL_FRIEND_CONTEXT (t))
12003 SET_DECL_FRIEND_CONTEXT (r,
12004 tsubst (DECL_FRIEND_CONTEXT (t),
12005 args, complain, in_decl));
12007 /* Possibly limit visibility based on template args. */
12008 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
12009 if (DECL_VISIBILITY_SPECIFIED (t))
12011 DECL_VISIBILITY_SPECIFIED (r) = 0;
12012 DECL_ATTRIBUTES (r)
12013 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
12015 determine_visibility (r);
12016 if (DECL_DEFAULTED_OUTSIDE_CLASS_P (r)
12017 && !processing_template_decl)
12018 defaulted_late_check (r);
12020 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
12021 args, complain, in_decl);
12027 tree type = NULL_TREE;
12029 tree expanded_types = NULL_TREE;
12030 tree prev_r = NULL_TREE;
12031 tree first_r = NULL_TREE;
12033 if (DECL_PACK_P (t))
12035 /* If there is a local specialization that isn't a
12036 parameter pack, it means that we're doing a "simple"
12037 substitution from inside tsubst_pack_expansion. Just
12038 return the local specialization (which will be a single
12040 tree spec = retrieve_local_specialization (t);
12042 && TREE_CODE (spec) == PARM_DECL
12043 && TREE_CODE (TREE_TYPE (spec)) != TYPE_PACK_EXPANSION)
12046 /* Expand the TYPE_PACK_EXPANSION that provides the types for
12047 the parameters in this function parameter pack. */
12048 expanded_types = tsubst_pack_expansion (TREE_TYPE (t), args,
12049 complain, in_decl);
12050 if (TREE_CODE (expanded_types) == TREE_VEC)
12052 len = TREE_VEC_LENGTH (expanded_types);
12054 /* Zero-length parameter packs are boring. Just substitute
12057 RETURN (tsubst (TREE_CHAIN (t), args, complain,
12062 /* All we did was update the type. Make a note of that. */
12063 type = expanded_types;
12064 expanded_types = NULL_TREE;
12068 /* Loop through all of the parameters we'll build. When T is
12069 a function parameter pack, LEN is the number of expanded
12070 types in EXPANDED_TYPES; otherwise, LEN is 1. */
12072 for (i = 0; i < len; ++i)
12076 if (DECL_TEMPLATE_PARM_P (t))
12077 SET_DECL_TEMPLATE_PARM_P (r);
12079 if (expanded_types)
12080 /* We're on the Ith parameter of the function parameter
12083 /* Get the Ith type. */
12084 type = TREE_VEC_ELT (expanded_types, i);
12086 /* Rename the parameter to include the index. */
12088 = make_ith_pack_parameter_name (DECL_NAME (r), i);
12091 /* We're dealing with a normal parameter. */
12092 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12094 type = type_decays_to (type);
12095 TREE_TYPE (r) = type;
12096 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
12098 if (DECL_INITIAL (r))
12100 if (TREE_CODE (DECL_INITIAL (r)) != TEMPLATE_PARM_INDEX)
12101 DECL_INITIAL (r) = TREE_TYPE (r);
12103 DECL_INITIAL (r) = tsubst (DECL_INITIAL (r), args,
12104 complain, in_decl);
12107 DECL_CONTEXT (r) = NULL_TREE;
12109 if (!DECL_TEMPLATE_PARM_P (r))
12110 DECL_ARG_TYPE (r) = type_passed_as (type);
12112 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
12113 args, complain, in_decl);
12115 /* Keep track of the first new parameter we
12116 generate. That's what will be returned to the
12121 /* Build a proper chain of parameters when substituting
12122 into a function parameter pack. */
12124 DECL_CHAIN (prev_r) = r;
12127 /* If cp_unevaluated_operand is set, we're just looking for a
12128 single dummy parameter, so don't keep going. */
12129 if (DECL_CHAIN (t) && !cp_unevaluated_operand)
12130 DECL_CHAIN (r) = tsubst (DECL_CHAIN (t), args,
12131 complain, DECL_CHAIN (t));
12133 /* FIRST_R contains the start of the chain we've built. */
12140 tree type = NULL_TREE;
12141 tree vec = NULL_TREE;
12142 tree expanded_types = NULL_TREE;
12145 if (PACK_EXPANSION_P (TREE_TYPE (t)))
12147 /* This field is a lambda capture pack. Return a TREE_VEC of
12148 the expanded fields to instantiate_class_template_1 and
12149 store them in the specializations hash table as a
12150 NONTYPE_ARGUMENT_PACK so that tsubst_copy can find them. */
12151 expanded_types = tsubst_pack_expansion (TREE_TYPE (t), args,
12152 complain, in_decl);
12153 if (TREE_CODE (expanded_types) == TREE_VEC)
12155 len = TREE_VEC_LENGTH (expanded_types);
12156 vec = make_tree_vec (len);
12160 /* All we did was update the type. Make a note of that. */
12161 type = expanded_types;
12162 expanded_types = NULL_TREE;
12166 for (int i = 0; i < len; ++i)
12169 if (expanded_types)
12171 type = TREE_VEC_ELT (expanded_types, i);
12173 = make_ith_pack_parameter_name (DECL_NAME (r), i);
12176 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12178 if (type == error_mark_node)
12179 RETURN (error_mark_node);
12180 TREE_TYPE (r) = type;
12181 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
12183 if (DECL_C_BIT_FIELD (r))
12184 /* For bit-fields, DECL_INITIAL gives the number of bits. For
12185 non-bit-fields DECL_INITIAL is a non-static data member
12186 initializer, which gets deferred instantiation. */
12188 = tsubst_expr (DECL_INITIAL (t), args,
12190 /*integral_constant_expression_p=*/true);
12191 else if (DECL_INITIAL (t))
12193 /* Set up DECL_TEMPLATE_INFO so that we can get at the
12194 NSDMI in perform_member_init. Still set DECL_INITIAL
12195 so that we know there is one. */
12196 DECL_INITIAL (r) = void_node;
12197 gcc_assert (DECL_LANG_SPECIFIC (r) == NULL);
12198 retrofit_lang_decl (r);
12199 DECL_TEMPLATE_INFO (r) = build_template_info (t, args);
12201 /* We don't have to set DECL_CONTEXT here; it is set by
12202 finish_member_declaration. */
12203 DECL_CHAIN (r) = NULL_TREE;
12205 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
12206 args, complain, in_decl);
12209 TREE_VEC_ELT (vec, i) = r;
12215 tree pack = make_node (NONTYPE_ARGUMENT_PACK);
12216 tree tpack = cxx_make_type (TYPE_ARGUMENT_PACK);
12217 SET_ARGUMENT_PACK_ARGS (pack, vec);
12218 SET_ARGUMENT_PACK_ARGS (tpack, expanded_types);
12219 TREE_TYPE (pack) = tpack;
12220 register_specialization (pack, t, args, false, 0);
12226 /* We reach here only for member using decls. We also need to check
12227 uses_template_parms because DECL_DEPENDENT_P is not set for a
12228 using-declaration that designates a member of the current
12229 instantiation (c++/53549). */
12230 if (DECL_DEPENDENT_P (t)
12231 || uses_template_parms (USING_DECL_SCOPE (t)))
12233 tree inst_scope = tsubst_copy (USING_DECL_SCOPE (t), args,
12234 complain, in_decl);
12235 tree name = tsubst_copy (DECL_NAME (t), args, complain, in_decl);
12236 r = do_class_using_decl (inst_scope, name);
12238 r = error_mark_node;
12241 TREE_PROTECTED (r) = TREE_PROTECTED (t);
12242 TREE_PRIVATE (r) = TREE_PRIVATE (t);
12248 DECL_CHAIN (r) = NULL_TREE;
12255 tree argvec = NULL_TREE;
12256 tree gen_tmpl = NULL_TREE;
12258 tree tmpl = NULL_TREE;
12260 tree type = NULL_TREE;
12263 if (TREE_TYPE (t) == error_mark_node)
12264 RETURN (error_mark_node);
12266 if (TREE_CODE (t) == TYPE_DECL
12267 && t == TYPE_MAIN_DECL (TREE_TYPE (t)))
12269 /* If this is the canonical decl, we don't have to
12270 mess with instantiations, and often we can't (for
12271 typename, template type parms and such). Note that
12272 TYPE_NAME is not correct for the above test if
12273 we've copied the type for a typedef. */
12274 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12275 if (type == error_mark_node)
12276 RETURN (error_mark_node);
12277 r = TYPE_NAME (type);
12281 /* Check to see if we already have the specialization we
12284 if (DECL_CLASS_SCOPE_P (t) || DECL_NAMESPACE_SCOPE_P (t))
12286 /* T is a static data member or namespace-scope entity.
12287 We have to substitute into namespace-scope variables
12288 (not just variable templates) because of cases like:
12290 template <class T> void f() { extern T t; }
12292 where the entity referenced is not known until
12293 instantiation time. */
12295 ctx = DECL_CONTEXT (t);
12296 if (DECL_CLASS_SCOPE_P (t))
12298 ctx = tsubst_aggr_type (ctx, args,
12300 in_decl, /*entering_scope=*/1);
12301 /* If CTX is unchanged, then T is in fact the
12302 specialization we want. That situation occurs when
12303 referencing a static data member within in its own
12304 class. We can use pointer equality, rather than
12305 same_type_p, because DECL_CONTEXT is always
12307 if (ctx == DECL_CONTEXT (t)
12308 /* ... unless T is a member template; in which
12309 case our caller can be willing to create a
12310 specialization of that template represented
12312 && !(DECL_TI_TEMPLATE (t)
12313 && DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (t))))
12319 tmpl = DECL_TI_TEMPLATE (t);
12320 gen_tmpl = most_general_template (tmpl);
12321 argvec = tsubst (DECL_TI_ARGS (t), args, complain, in_decl);
12322 if (argvec != error_mark_node)
12323 argvec = (coerce_innermost_template_parms
12324 (DECL_TEMPLATE_PARMS (gen_tmpl),
12325 argvec, t, complain,
12326 /*all*/true, /*defarg*/true));
12327 if (argvec == error_mark_node)
12328 RETURN (error_mark_node);
12329 hash = hash_tmpl_and_args (gen_tmpl, argvec);
12330 spec = retrieve_specialization (gen_tmpl, argvec, hash);
12335 /* A local variable. */
12337 /* Subsequent calls to pushdecl will fill this in. */
12339 /* Unless this is a reference to a static variable from an
12340 enclosing function, in which case we need to fill it in now. */
12341 if (TREE_STATIC (t))
12343 tree fn = tsubst (DECL_CONTEXT (t), args, complain, in_decl);
12344 if (fn != current_function_decl)
12347 spec = retrieve_local_specialization (t);
12349 /* If we already have the specialization we need, there is
12350 nothing more to do. */
12357 /* Create a new node for the specialization we need. */
12359 if (type == NULL_TREE)
12361 if (is_typedef_decl (t))
12362 type = DECL_ORIGINAL_TYPE (t);
12364 type = TREE_TYPE (t);
12366 && VAR_HAD_UNKNOWN_BOUND (t)
12367 && type != error_mark_node)
12368 type = strip_array_domain (type);
12369 type = tsubst (type, args, complain, in_decl);
12373 /* Even if the original location is out of scope, the
12374 newly substituted one is not. */
12375 DECL_DEAD_FOR_LOCAL (r) = 0;
12376 DECL_INITIALIZED_P (r) = 0;
12377 DECL_TEMPLATE_INSTANTIATED (r) = 0;
12378 if (type == error_mark_node)
12379 RETURN (error_mark_node);
12380 if (TREE_CODE (type) == FUNCTION_TYPE)
12382 /* It may seem that this case cannot occur, since:
12387 declares a function, not a variable. However:
12390 template <typename T> void g() { T t; }
12391 template void g<f>();
12393 is an attempt to declare a variable with function
12395 error ("variable %qD has function type",
12396 /* R is not yet sufficiently initialized, so we
12397 just use its name. */
12399 RETURN (error_mark_node);
12401 type = complete_type (type);
12402 /* Wait until cp_finish_decl to set this again, to handle
12403 circular dependency (template/instantiate6.C). */
12404 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r) = 0;
12405 type = check_var_type (DECL_NAME (r), type);
12407 if (DECL_HAS_VALUE_EXPR_P (t))
12409 tree ve = DECL_VALUE_EXPR (t);
12410 ve = tsubst_expr (ve, args, complain, in_decl,
12411 /*constant_expression_p=*/false);
12412 if (REFERENCE_REF_P (ve))
12414 gcc_assert (TREE_CODE (type) == REFERENCE_TYPE);
12415 ve = TREE_OPERAND (ve, 0);
12417 SET_DECL_VALUE_EXPR (r, ve);
12419 if (CP_DECL_THREAD_LOCAL_P (r)
12420 && !processing_template_decl)
12421 set_decl_tls_model (r, decl_default_tls_model (r));
12423 else if (DECL_SELF_REFERENCE_P (t))
12424 SET_DECL_SELF_REFERENCE_P (r);
12425 TREE_TYPE (r) = type;
12426 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
12427 DECL_CONTEXT (r) = ctx;
12428 /* Clear out the mangled name and RTL for the instantiation. */
12429 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
12430 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
12431 SET_DECL_RTL (r, NULL);
12432 /* The initializer must not be expanded until it is required;
12433 see [temp.inst]. */
12434 DECL_INITIAL (r) = NULL_TREE;
12436 DECL_MODE (r) = VOIDmode;
12437 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
12438 SET_DECL_RTL (r, NULL);
12439 DECL_SIZE (r) = DECL_SIZE_UNIT (r) = 0;
12442 /* Possibly limit visibility based on template args. */
12443 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
12444 if (DECL_VISIBILITY_SPECIFIED (t))
12446 DECL_VISIBILITY_SPECIFIED (r) = 0;
12447 DECL_ATTRIBUTES (r)
12448 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
12450 determine_visibility (r);
12455 /* A static data member declaration is always marked
12456 external when it is declared in-class, even if an
12457 initializer is present. We mimic the non-template
12458 processing here. */
12459 DECL_EXTERNAL (r) = 1;
12460 if (DECL_NAMESPACE_SCOPE_P (t))
12461 DECL_NOT_REALLY_EXTERN (r) = 1;
12463 DECL_TEMPLATE_INFO (r) = build_template_info (tmpl, argvec);
12464 SET_DECL_IMPLICIT_INSTANTIATION (r);
12465 register_specialization (r, gen_tmpl, argvec, false, hash);
12469 if (DECL_LANG_SPECIFIC (r))
12470 DECL_TEMPLATE_INFO (r) = NULL_TREE;
12471 if (!cp_unevaluated_operand)
12472 register_local_specialization (r, t);
12475 DECL_CHAIN (r) = NULL_TREE;
12477 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r),
12479 args, complain, in_decl);
12481 /* Preserve a typedef that names a type. */
12482 if (is_typedef_decl (r))
12484 DECL_ORIGINAL_TYPE (r) = NULL_TREE;
12485 set_underlying_type (r);
12486 if (TYPE_DECL_ALIAS_P (r) && type != error_mark_node)
12487 /* An alias template specialization can be dependent
12488 even if its underlying type is not. */
12489 TYPE_DEPENDENT_P_VALID (TREE_TYPE (r)) = false;
12492 layout_decl (r, 0);
12497 gcc_unreachable ();
12502 /* Restore the file and line information. */
12503 input_location = saved_loc;
12508 /* Substitute into the ARG_TYPES of a function type.
12509 If END is a TREE_CHAIN, leave it and any following types
12513 tsubst_arg_types (tree arg_types,
12516 tsubst_flags_t complain,
12519 tree remaining_arg_types;
12520 tree type = NULL_TREE;
12522 tree expanded_args = NULL_TREE;
12525 if (!arg_types || arg_types == void_list_node || arg_types == end)
12528 remaining_arg_types = tsubst_arg_types (TREE_CHAIN (arg_types),
12529 args, end, complain, in_decl);
12530 if (remaining_arg_types == error_mark_node)
12531 return error_mark_node;
12533 if (PACK_EXPANSION_P (TREE_VALUE (arg_types)))
12535 /* For a pack expansion, perform substitution on the
12536 entire expression. Later on, we'll handle the arguments
12538 expanded_args = tsubst_pack_expansion (TREE_VALUE (arg_types),
12539 args, complain, in_decl);
12541 if (TREE_CODE (expanded_args) == TREE_VEC)
12542 /* So that we'll spin through the parameters, one by one. */
12543 i = TREE_VEC_LENGTH (expanded_args);
12546 /* We only partially substituted into the parameter
12547 pack. Our type is TYPE_PACK_EXPANSION. */
12548 type = expanded_args;
12549 expanded_args = NULL_TREE;
12557 type = TREE_VEC_ELT (expanded_args, i);
12559 type = tsubst (TREE_VALUE (arg_types), args, complain, in_decl);
12561 if (type == error_mark_node)
12562 return error_mark_node;
12563 if (VOID_TYPE_P (type))
12565 if (complain & tf_error)
12567 error ("invalid parameter type %qT", type);
12569 error ("in declaration %q+D", in_decl);
12571 return error_mark_node;
12574 if (abstract_virtuals_error_sfinae (ACU_PARM, type, complain))
12575 return error_mark_node;
12577 /* Do array-to-pointer, function-to-pointer conversion, and ignore
12578 top-level qualifiers as required. */
12579 type = cv_unqualified (type_decays_to (type));
12581 /* We do not substitute into default arguments here. The standard
12582 mandates that they be instantiated only when needed, which is
12583 done in build_over_call. */
12584 default_arg = TREE_PURPOSE (arg_types);
12586 if (default_arg && TREE_CODE (default_arg) == DEFAULT_ARG)
12588 /* We've instantiated a template before its default arguments
12589 have been parsed. This can happen for a nested template
12590 class, and is not an error unless we require the default
12591 argument in a call of this function. */
12592 remaining_arg_types =
12593 tree_cons (default_arg, type, remaining_arg_types);
12594 vec_safe_push (DEFARG_INSTANTIATIONS(default_arg), remaining_arg_types);
12597 remaining_arg_types =
12598 hash_tree_cons (default_arg, type, remaining_arg_types);
12601 return remaining_arg_types;
12604 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
12605 *not* handle the exception-specification for FNTYPE, because the
12606 initial substitution of explicitly provided template parameters
12607 during argument deduction forbids substitution into the
12608 exception-specification:
12612 All references in the function type of the function template to the
12613 corresponding template parameters are replaced by the specified tem-
12614 plate argument values. If a substitution in a template parameter or
12615 in the function type of the function template results in an invalid
12616 type, type deduction fails. [Note: The equivalent substitution in
12617 exception specifications is done only when the function is instanti-
12618 ated, at which point a program is ill-formed if the substitution
12619 results in an invalid type.] */
12622 tsubst_function_type (tree t,
12624 tsubst_flags_t complain,
12628 tree arg_types = NULL_TREE;
12631 /* The TYPE_CONTEXT is not used for function/method types. */
12632 gcc_assert (TYPE_CONTEXT (t) == NULL_TREE);
12634 /* DR 1227: Mixing immediate and non-immediate contexts in deduction
12636 bool late_return_type_p = TYPE_HAS_LATE_RETURN_TYPE (t);
12638 if (late_return_type_p)
12640 /* Substitute the argument types. */
12641 arg_types = tsubst_arg_types (TYPE_ARG_TYPES (t), args, NULL_TREE,
12642 complain, in_decl);
12643 if (arg_types == error_mark_node)
12644 return error_mark_node;
12646 tree save_ccp = current_class_ptr;
12647 tree save_ccr = current_class_ref;
12648 tree this_type = (TREE_CODE (t) == METHOD_TYPE
12649 ? TREE_TYPE (TREE_VALUE (arg_types)) : NULL_TREE);
12650 bool do_inject = this_type && CLASS_TYPE_P (this_type);
12653 /* DR 1207: 'this' is in scope in the trailing return type. */
12654 inject_this_parameter (this_type, cp_type_quals (this_type));
12657 /* Substitute the return type. */
12658 return_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12662 current_class_ptr = save_ccp;
12663 current_class_ref = save_ccr;
12667 /* Substitute the return type. */
12668 return_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12670 if (return_type == error_mark_node)
12671 return error_mark_node;
12672 /* DR 486 clarifies that creation of a function type with an
12673 invalid return type is a deduction failure. */
12674 if (TREE_CODE (return_type) == ARRAY_TYPE
12675 || TREE_CODE (return_type) == FUNCTION_TYPE)
12677 if (complain & tf_error)
12679 if (TREE_CODE (return_type) == ARRAY_TYPE)
12680 error ("function returning an array");
12682 error ("function returning a function");
12684 return error_mark_node;
12687 if (abstract_virtuals_error_sfinae (ACU_RETURN, return_type, complain))
12688 return error_mark_node;
12690 if (!late_return_type_p)
12692 /* Substitute the argument types. */
12693 arg_types = tsubst_arg_types (TYPE_ARG_TYPES (t), args, NULL_TREE,
12694 complain, in_decl);
12695 if (arg_types == error_mark_node)
12696 return error_mark_node;
12699 /* Construct a new type node and return it. */
12700 if (TREE_CODE (t) == FUNCTION_TYPE)
12702 fntype = build_function_type (return_type, arg_types);
12703 fntype = apply_memfn_quals (fntype,
12704 type_memfn_quals (t),
12705 type_memfn_rqual (t));
12709 tree r = TREE_TYPE (TREE_VALUE (arg_types));
12710 /* Don't pick up extra function qualifiers from the basetype. */
12711 r = cp_build_qualified_type_real (r, type_memfn_quals (t), complain);
12712 if (! MAYBE_CLASS_TYPE_P (r))
12716 Type deduction may fail for any of the following
12719 -- Attempting to create "pointer to member of T" when T
12720 is not a class type. */
12721 if (complain & tf_error)
12722 error ("creating pointer to member function of non-class type %qT",
12724 return error_mark_node;
12727 fntype = build_method_type_directly (r, return_type,
12728 TREE_CHAIN (arg_types));
12729 fntype = build_ref_qualified_type (fntype, type_memfn_rqual (t));
12731 fntype = cp_build_type_attribute_variant (fntype, TYPE_ATTRIBUTES (t));
12733 if (late_return_type_p)
12734 TYPE_HAS_LATE_RETURN_TYPE (fntype) = 1;
12739 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
12740 ARGS into that specification, and return the substituted
12741 specification. If there is no specification, return NULL_TREE. */
12744 tsubst_exception_specification (tree fntype,
12746 tsubst_flags_t complain,
12753 specs = TYPE_RAISES_EXCEPTIONS (fntype);
12754 new_specs = NULL_TREE;
12755 if (specs && TREE_PURPOSE (specs))
12757 /* A noexcept-specifier. */
12758 tree expr = TREE_PURPOSE (specs);
12759 if (TREE_CODE (expr) == INTEGER_CST)
12763 /* Defer instantiation of noexcept-specifiers to avoid
12764 excessive instantiations (c++/49107). */
12765 new_specs = make_node (DEFERRED_NOEXCEPT);
12766 if (DEFERRED_NOEXCEPT_SPEC_P (specs))
12768 /* We already partially instantiated this member template,
12769 so combine the new args with the old. */
12770 DEFERRED_NOEXCEPT_PATTERN (new_specs)
12771 = DEFERRED_NOEXCEPT_PATTERN (expr);
12772 DEFERRED_NOEXCEPT_ARGS (new_specs)
12773 = add_to_template_args (DEFERRED_NOEXCEPT_ARGS (expr), args);
12777 DEFERRED_NOEXCEPT_PATTERN (new_specs) = expr;
12778 DEFERRED_NOEXCEPT_ARGS (new_specs) = args;
12782 new_specs = tsubst_copy_and_build
12783 (expr, args, complain, in_decl, /*function_p=*/false,
12784 /*integral_constant_expression_p=*/true);
12785 new_specs = build_noexcept_spec (new_specs, complain);
12789 if (! TREE_VALUE (specs))
12796 tree expanded_specs = NULL_TREE;
12798 if (PACK_EXPANSION_P (TREE_VALUE (specs)))
12800 /* Expand the pack expansion type. */
12801 expanded_specs = tsubst_pack_expansion (TREE_VALUE (specs),
12805 if (expanded_specs == error_mark_node)
12806 return error_mark_node;
12807 else if (TREE_CODE (expanded_specs) == TREE_VEC)
12808 len = TREE_VEC_LENGTH (expanded_specs);
12811 /* We're substituting into a member template, so
12812 we got a TYPE_PACK_EXPANSION back. Add that
12813 expansion and move on. */
12814 gcc_assert (TREE_CODE (expanded_specs)
12815 == TYPE_PACK_EXPANSION);
12816 new_specs = add_exception_specifier (new_specs,
12819 specs = TREE_CHAIN (specs);
12824 for (i = 0; i < len; ++i)
12826 if (expanded_specs)
12827 spec = TREE_VEC_ELT (expanded_specs, i);
12829 spec = tsubst (TREE_VALUE (specs), args, complain, in_decl);
12830 if (spec == error_mark_node)
12832 new_specs = add_exception_specifier (new_specs, spec,
12836 specs = TREE_CHAIN (specs);
12842 /* Take the tree structure T and replace template parameters used
12843 therein with the argument vector ARGS. IN_DECL is an associated
12844 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
12845 Issue error and warning messages under control of COMPLAIN. Note
12846 that we must be relatively non-tolerant of extensions here, in
12847 order to preserve conformance; if we allow substitutions that
12848 should not be allowed, we may allow argument deductions that should
12849 not succeed, and therefore report ambiguous overload situations
12850 where there are none. In theory, we could allow the substitution,
12851 but indicate that it should have failed, and allow our caller to
12852 make sure that the right thing happens, but we don't try to do this
12855 This function is used for dealing with types, decls and the like;
12856 for expressions, use tsubst_expr or tsubst_copy. */
12859 tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl)
12861 enum tree_code code;
12862 tree type, r = NULL_TREE;
12864 if (t == NULL_TREE || t == error_mark_node
12865 || t == integer_type_node
12866 || t == void_type_node
12867 || t == char_type_node
12868 || t == unknown_type_node
12869 || TREE_CODE (t) == NAMESPACE_DECL
12870 || TREE_CODE (t) == TRANSLATION_UNIT_DECL)
12874 return tsubst_decl (t, args, complain);
12876 if (args == NULL_TREE)
12879 code = TREE_CODE (t);
12881 if (code == IDENTIFIER_NODE)
12882 type = IDENTIFIER_TYPE_VALUE (t);
12884 type = TREE_TYPE (t);
12886 gcc_assert (type != unknown_type_node);
12888 /* Reuse typedefs. We need to do this to handle dependent attributes,
12889 such as attribute aligned. */
12891 && typedef_variant_p (t))
12893 tree decl = TYPE_NAME (t);
12895 if (alias_template_specialization_p (t))
12897 /* DECL represents an alias template and we want to
12899 tree tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
12900 tree gen_args = tsubst (DECL_TI_ARGS (decl), args, complain, in_decl);
12901 r = instantiate_alias_template (tmpl, gen_args, complain);
12903 else if (DECL_CLASS_SCOPE_P (decl)
12904 && CLASSTYPE_TEMPLATE_INFO (DECL_CONTEXT (decl))
12905 && uses_template_parms (DECL_CONTEXT (decl)))
12907 tree tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
12908 tree gen_args = tsubst (DECL_TI_ARGS (decl), args, complain, in_decl);
12909 r = retrieve_specialization (tmpl, gen_args, 0);
12911 else if (DECL_FUNCTION_SCOPE_P (decl)
12912 && DECL_TEMPLATE_INFO (DECL_CONTEXT (decl))
12913 && uses_template_parms (DECL_TI_ARGS (DECL_CONTEXT (decl))))
12914 r = retrieve_local_specialization (decl);
12916 /* The typedef is from a non-template context. */
12922 r = cp_build_qualified_type_real
12923 (r, cp_type_quals (t) | cp_type_quals (r),
12924 complain | tf_ignore_bad_quals);
12929 /* We don't have an instantiation yet, so drop the typedef. */
12930 int quals = cp_type_quals (t);
12931 t = DECL_ORIGINAL_TYPE (decl);
12932 t = cp_build_qualified_type_real (t, quals,
12933 complain | tf_ignore_bad_quals);
12938 && code != TYPENAME_TYPE
12939 && code != TEMPLATE_TYPE_PARM
12940 && code != IDENTIFIER_NODE
12941 && code != FUNCTION_TYPE
12942 && code != METHOD_TYPE)
12943 type = tsubst (type, args, complain, in_decl);
12944 if (type == error_mark_node)
12945 return error_mark_node;
12951 case ENUMERAL_TYPE:
12952 return tsubst_aggr_type (t, args, complain, in_decl,
12953 /*entering_scope=*/0);
12956 case IDENTIFIER_NODE:
12967 if (t == integer_type_node)
12970 if (TREE_CODE (TYPE_MIN_VALUE (t)) == INTEGER_CST
12971 && TREE_CODE (TYPE_MAX_VALUE (t)) == INTEGER_CST)
12975 tree max, omax = TREE_OPERAND (TYPE_MAX_VALUE (t), 0);
12977 max = tsubst_expr (omax, args, complain, in_decl,
12978 /*integral_constant_expression_p=*/false);
12980 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
12982 if (TREE_CODE (max) == NOP_EXPR
12983 && TREE_SIDE_EFFECTS (omax)
12984 && !TREE_TYPE (max))
12985 TREE_TYPE (max) = TREE_TYPE (TREE_OPERAND (max, 0));
12987 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
12988 with TREE_SIDE_EFFECTS that indicates this is not an integral
12989 constant expression. */
12990 if (processing_template_decl
12991 && TREE_SIDE_EFFECTS (omax) && TREE_CODE (omax) == NOP_EXPR)
12993 gcc_assert (TREE_CODE (max) == NOP_EXPR);
12994 TREE_SIDE_EFFECTS (max) = 1;
12997 return compute_array_index_type (NULL_TREE, max, complain);
13000 case TEMPLATE_TYPE_PARM:
13001 case TEMPLATE_TEMPLATE_PARM:
13002 case BOUND_TEMPLATE_TEMPLATE_PARM:
13003 case TEMPLATE_PARM_INDEX:
13008 tree arg = NULL_TREE;
13010 /* Early in template argument deduction substitution, we don't
13011 want to reduce the level of 'auto', or it will be confused
13012 with a normal template parm in subsequent deduction. */
13013 if (is_auto (t) && (complain & tf_partial))
13018 gcc_assert (TREE_VEC_LENGTH (args) > 0);
13019 template_parm_level_and_index (t, &level, &idx);
13021 levels = TMPL_ARGS_DEPTH (args);
13022 if (level <= levels
13023 && TREE_VEC_LENGTH (TMPL_ARGS_LEVEL (args, level)) > 0)
13025 arg = TMPL_ARG (args, level, idx);
13027 if (arg && TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
13029 /* See through ARGUMENT_PACK_SELECT arguments. */
13030 arg = ARGUMENT_PACK_SELECT_ARG (arg);
13031 /* If the selected argument is an expansion E, that most
13032 likely means we were called from
13033 gen_elem_of_pack_expansion_instantiation during the
13034 substituting of pack an argument pack (which Ith
13035 element is a pack expansion, where I is
13036 ARGUMENT_PACK_SELECT_INDEX) into a pack expansion.
13037 In this case, the Ith element resulting from this
13038 substituting is going to be a pack expansion, which
13039 pattern is the pattern of E. Let's return the
13041 gen_elem_of_pack_expansion_instantiation will
13042 build the resulting pack expansion from it. */
13043 if (PACK_EXPANSION_P (arg))
13045 /* Make sure we aren't throwing away arg info. */
13046 gcc_assert (!PACK_EXPANSION_EXTRA_ARGS (arg));
13047 arg = PACK_EXPANSION_PATTERN (arg);
13052 if (arg == error_mark_node)
13053 return error_mark_node;
13054 else if (arg != NULL_TREE)
13056 if (ARGUMENT_PACK_P (arg))
13057 /* If ARG is an argument pack, we don't actually want to
13058 perform a substitution here, because substitutions
13059 for argument packs are only done
13060 element-by-element. We can get to this point when
13061 substituting the type of a non-type template
13062 parameter pack, when that type actually contains
13063 template parameter packs from an outer template, e.g.,
13065 template<typename... Types> struct A {
13066 template<Types... Values> struct B { };
13070 if (code == TEMPLATE_TYPE_PARM)
13073 gcc_assert (TYPE_P (arg));
13075 quals = cp_type_quals (arg) | cp_type_quals (t);
13077 return cp_build_qualified_type_real
13078 (arg, quals, complain | tf_ignore_bad_quals);
13080 else if (code == BOUND_TEMPLATE_TEMPLATE_PARM)
13082 /* We are processing a type constructed from a
13083 template template parameter. */
13084 tree argvec = tsubst (TYPE_TI_ARGS (t),
13085 args, complain, in_decl);
13086 if (argvec == error_mark_node)
13087 return error_mark_node;
13089 gcc_assert (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
13090 || TREE_CODE (arg) == TEMPLATE_DECL
13091 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE);
13093 if (TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE)
13094 /* Consider this code:
13096 template <template <class> class Template>
13098 template <class Arg> using Bind = Template<Arg>;
13101 template <template <class> class Template, class Arg>
13102 using Instantiate = Template<Arg>; //#0
13104 template <template <class> class Template,
13107 Instantiate<Internal<Template>::template Bind,
13110 When #1 is parsed, the
13111 BOUND_TEMPLATE_TEMPLATE_PARM representing the
13112 parameter `Template' in #0 matches the
13113 UNBOUND_CLASS_TEMPLATE representing the argument
13114 `Internal<Template>::template Bind'; We then want
13115 to assemble the type `Bind<Argument>' that can't
13116 be fully created right now, because
13117 `Internal<Template>' not being complete, the Bind
13118 template cannot be looked up in that context. So
13119 we need to "store" `Bind<Argument>' for later
13120 when the context of Bind becomes complete. Let's
13121 store that in a TYPENAME_TYPE. */
13122 return make_typename_type (TYPE_CONTEXT (arg),
13123 build_nt (TEMPLATE_ID_EXPR,
13124 TYPE_IDENTIFIER (arg),
13129 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
13130 are resolving nested-types in the signature of a
13131 member function templates. Otherwise ARG is a
13132 TEMPLATE_DECL and is the real template to be
13134 if (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
13135 arg = TYPE_NAME (arg);
13137 r = lookup_template_class (arg,
13139 DECL_CONTEXT (arg),
13140 /*entering_scope=*/0,
13142 return cp_build_qualified_type_real
13143 (r, cp_type_quals (t) | cp_type_quals (r), complain);
13146 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
13147 return convert_from_reference (unshare_expr (arg));
13151 /* This can happen during the attempted tsubst'ing in
13152 unify. This means that we don't yet have any information
13153 about the template parameter in question. */
13156 /* If we get here, we must have been looking at a parm for a
13157 more deeply nested template. Make a new version of this
13158 template parameter, but with a lower level. */
13161 case TEMPLATE_TYPE_PARM:
13162 case TEMPLATE_TEMPLATE_PARM:
13163 case BOUND_TEMPLATE_TEMPLATE_PARM:
13164 if (cp_type_quals (t))
13166 r = tsubst (TYPE_MAIN_VARIANT (t), args, complain, in_decl);
13167 r = cp_build_qualified_type_real
13168 (r, cp_type_quals (t),
13169 complain | (code == TEMPLATE_TYPE_PARM
13170 ? tf_ignore_bad_quals : 0));
13172 else if (TREE_CODE (t) == TEMPLATE_TYPE_PARM
13173 && PLACEHOLDER_TYPE_CONSTRAINTS (t)
13174 && (r = (TEMPLATE_PARM_DESCENDANTS
13175 (TEMPLATE_TYPE_PARM_INDEX (t))))
13176 && (r = TREE_TYPE (r))
13177 && !PLACEHOLDER_TYPE_CONSTRAINTS (r))
13178 /* Break infinite recursion when substituting the constraints
13179 of a constrained placeholder. */;
13183 TEMPLATE_TYPE_PARM_INDEX (r)
13184 = reduce_template_parm_level (TEMPLATE_TYPE_PARM_INDEX (t),
13185 r, levels, args, complain);
13186 TYPE_STUB_DECL (r) = TYPE_NAME (r) = TEMPLATE_TYPE_DECL (r);
13187 TYPE_MAIN_VARIANT (r) = r;
13188 TYPE_POINTER_TO (r) = NULL_TREE;
13189 TYPE_REFERENCE_TO (r) = NULL_TREE;
13191 /* Propagate constraints on placeholders. */
13192 if (TREE_CODE (t) == TEMPLATE_TYPE_PARM)
13193 if (tree constr = PLACEHOLDER_TYPE_CONSTRAINTS (t))
13194 PLACEHOLDER_TYPE_CONSTRAINTS (r)
13195 = tsubst_constraint (constr, args, complain, in_decl);
13197 if (TREE_CODE (r) == TEMPLATE_TEMPLATE_PARM)
13198 /* We have reduced the level of the template
13199 template parameter, but not the levels of its
13200 template parameters, so canonical_type_parameter
13201 will not be able to find the canonical template
13202 template parameter for this level. Thus, we
13203 require structural equality checking to compare
13204 TEMPLATE_TEMPLATE_PARMs. */
13205 SET_TYPE_STRUCTURAL_EQUALITY (r);
13206 else if (TYPE_STRUCTURAL_EQUALITY_P (t))
13207 SET_TYPE_STRUCTURAL_EQUALITY (r);
13209 TYPE_CANONICAL (r) = canonical_type_parameter (r);
13211 if (code == BOUND_TEMPLATE_TEMPLATE_PARM)
13213 tree tinfo = TYPE_TEMPLATE_INFO (t);
13214 /* We might need to substitute into the types of non-type
13215 template parameters. */
13216 tree tmpl = tsubst (TI_TEMPLATE (tinfo), args,
13217 complain, in_decl);
13218 if (tmpl == error_mark_node)
13219 return error_mark_node;
13220 tree argvec = tsubst (TI_ARGS (tinfo), args,
13221 complain, in_decl);
13222 if (argvec == error_mark_node)
13223 return error_mark_node;
13225 TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (r)
13226 = build_template_info (tmpl, argvec);
13231 case TEMPLATE_PARM_INDEX:
13232 r = reduce_template_parm_level (t, type, levels, args, complain);
13236 gcc_unreachable ();
13244 tree purpose, value, chain;
13246 if (t == void_list_node)
13249 purpose = TREE_PURPOSE (t);
13252 purpose = tsubst (purpose, args, complain, in_decl);
13253 if (purpose == error_mark_node)
13254 return error_mark_node;
13256 value = TREE_VALUE (t);
13259 value = tsubst (value, args, complain, in_decl);
13260 if (value == error_mark_node)
13261 return error_mark_node;
13263 chain = TREE_CHAIN (t);
13264 if (chain && chain != void_type_node)
13266 chain = tsubst (chain, args, complain, in_decl);
13267 if (chain == error_mark_node)
13268 return error_mark_node;
13270 if (purpose == TREE_PURPOSE (t)
13271 && value == TREE_VALUE (t)
13272 && chain == TREE_CHAIN (t))
13274 return hash_tree_cons (purpose, value, chain);
13278 /* We should never be tsubsting a binfo. */
13279 gcc_unreachable ();
13282 /* A vector of template arguments. */
13283 gcc_assert (!type);
13284 return tsubst_template_args (t, args, complain, in_decl);
13287 case REFERENCE_TYPE:
13289 if (type == TREE_TYPE (t) && TREE_CODE (type) != METHOD_TYPE)
13294 Type deduction may fail for any of the following
13297 -- Attempting to create a pointer to reference type.
13298 -- Attempting to create a reference to a reference type or
13299 a reference to void.
13301 Core issue 106 says that creating a reference to a reference
13302 during instantiation is no longer a cause for failure. We
13303 only enforce this check in strict C++98 mode. */
13304 if ((TREE_CODE (type) == REFERENCE_TYPE
13305 && (((cxx_dialect == cxx98) && flag_iso) || code != REFERENCE_TYPE))
13306 || (code == REFERENCE_TYPE && VOID_TYPE_P (type)))
13308 static location_t last_loc;
13310 /* We keep track of the last time we issued this error
13311 message to avoid spewing a ton of messages during a
13312 single bad template instantiation. */
13313 if (complain & tf_error
13314 && last_loc != input_location)
13316 if (VOID_TYPE_P (type))
13317 error ("forming reference to void");
13318 else if (code == POINTER_TYPE)
13319 error ("forming pointer to reference type %qT", type);
13321 error ("forming reference to reference type %qT", type);
13322 last_loc = input_location;
13325 return error_mark_node;
13327 else if (TREE_CODE (type) == FUNCTION_TYPE
13328 && (type_memfn_quals (type) != TYPE_UNQUALIFIED
13329 || type_memfn_rqual (type) != REF_QUAL_NONE))
13331 if (complain & tf_error)
13333 if (code == POINTER_TYPE)
13334 error ("forming pointer to qualified function type %qT",
13337 error ("forming reference to qualified function type %qT",
13340 return error_mark_node;
13342 else if (code == POINTER_TYPE)
13344 r = build_pointer_type (type);
13345 if (TREE_CODE (type) == METHOD_TYPE)
13346 r = build_ptrmemfunc_type (r);
13348 else if (TREE_CODE (type) == REFERENCE_TYPE)
13349 /* In C++0x, during template argument substitution, when there is an
13350 attempt to create a reference to a reference type, reference
13351 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
13353 "If a template-argument for a template-parameter T names a type
13354 that is a reference to a type A, an attempt to create the type
13355 'lvalue reference to cv T' creates the type 'lvalue reference to
13356 A,' while an attempt to create the type type rvalue reference to
13357 cv T' creates the type T"
13359 r = cp_build_reference_type
13361 TYPE_REF_IS_RVALUE (t) && TYPE_REF_IS_RVALUE (type));
13363 r = cp_build_reference_type (type, TYPE_REF_IS_RVALUE (t));
13364 r = cp_build_qualified_type_real (r, cp_type_quals (t), complain);
13366 if (r != error_mark_node)
13367 /* Will this ever be needed for TYPE_..._TO values? */
13374 r = tsubst (TYPE_OFFSET_BASETYPE (t), args, complain, in_decl);
13375 if (r == error_mark_node || !MAYBE_CLASS_TYPE_P (r))
13379 Type deduction may fail for any of the following
13382 -- Attempting to create "pointer to member of T" when T
13383 is not a class type. */
13384 if (complain & tf_error)
13385 error ("creating pointer to member of non-class type %qT", r);
13386 return error_mark_node;
13388 if (TREE_CODE (type) == REFERENCE_TYPE)
13390 if (complain & tf_error)
13391 error ("creating pointer to member reference type %qT", type);
13392 return error_mark_node;
13394 if (VOID_TYPE_P (type))
13396 if (complain & tf_error)
13397 error ("creating pointer to member of type void");
13398 return error_mark_node;
13400 gcc_assert (TREE_CODE (type) != METHOD_TYPE);
13401 if (TREE_CODE (type) == FUNCTION_TYPE)
13403 /* The type of the implicit object parameter gets its
13404 cv-qualifiers from the FUNCTION_TYPE. */
13407 = build_memfn_type (type, r, type_memfn_quals (type),
13408 type_memfn_rqual (type));
13409 memptr = build_ptrmemfunc_type (build_pointer_type (method_type));
13410 return cp_build_qualified_type_real (memptr, cp_type_quals (t),
13414 return cp_build_qualified_type_real (build_ptrmem_type (r, type),
13418 case FUNCTION_TYPE:
13423 fntype = tsubst_function_type (t, args, complain, in_decl);
13424 if (fntype == error_mark_node)
13425 return error_mark_node;
13427 /* Substitute the exception specification. */
13428 specs = tsubst_exception_specification (t, args, complain,
13429 in_decl, /*defer_ok*/true);
13430 if (specs == error_mark_node)
13431 return error_mark_node;
13433 fntype = build_exception_variant (fntype, specs);
13438 tree domain = tsubst (TYPE_DOMAIN (t), args, complain, in_decl);
13439 if (domain == error_mark_node)
13440 return error_mark_node;
13442 /* As an optimization, we avoid regenerating the array type if
13443 it will obviously be the same as T. */
13444 if (type == TREE_TYPE (t) && domain == TYPE_DOMAIN (t))
13447 /* These checks should match the ones in create_array_type_for_decl.
13451 The deduction may fail for any of the following reasons:
13453 -- Attempting to create an array with an element type that
13454 is void, a function type, or a reference type, or [DR337]
13455 an abstract class type. */
13456 if (VOID_TYPE_P (type)
13457 || TREE_CODE (type) == FUNCTION_TYPE
13458 || (TREE_CODE (type) == ARRAY_TYPE
13459 && TYPE_DOMAIN (type) == NULL_TREE)
13460 || TREE_CODE (type) == REFERENCE_TYPE)
13462 if (complain & tf_error)
13463 error ("creating array of %qT", type);
13464 return error_mark_node;
13467 if (abstract_virtuals_error_sfinae (ACU_ARRAY, type, complain))
13468 return error_mark_node;
13470 r = build_cplus_array_type (type, domain);
13472 if (TYPE_USER_ALIGN (t))
13474 TYPE_ALIGN (r) = TYPE_ALIGN (t);
13475 TYPE_USER_ALIGN (r) = 1;
13481 case TYPENAME_TYPE:
13483 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
13484 in_decl, /*entering_scope=*/1);
13485 tree f = tsubst_copy (TYPENAME_TYPE_FULLNAME (t), args,
13486 complain, in_decl);
13488 if (ctx == error_mark_node || f == error_mark_node)
13489 return error_mark_node;
13491 if (!MAYBE_CLASS_TYPE_P (ctx))
13493 if (complain & tf_error)
13494 error ("%qT is not a class, struct, or union type", ctx);
13495 return error_mark_node;
13497 else if (!uses_template_parms (ctx) && !TYPE_BEING_DEFINED (ctx))
13499 /* Normally, make_typename_type does not require that the CTX
13500 have complete type in order to allow things like:
13502 template <class T> struct S { typename S<T>::X Y; };
13504 But, such constructs have already been resolved by this
13505 point, so here CTX really should have complete type, unless
13506 it's a partial instantiation. */
13507 ctx = complete_type (ctx);
13508 if (!COMPLETE_TYPE_P (ctx))
13510 if (complain & tf_error)
13511 cxx_incomplete_type_error (NULL_TREE, ctx);
13512 return error_mark_node;
13516 f = make_typename_type (ctx, f, typename_type,
13517 complain | tf_keep_type_decl);
13518 if (f == error_mark_node)
13520 if (TREE_CODE (f) == TYPE_DECL)
13522 complain |= tf_ignore_bad_quals;
13526 if (TREE_CODE (f) != TYPENAME_TYPE)
13528 if (TYPENAME_IS_ENUM_P (t) && TREE_CODE (f) != ENUMERAL_TYPE)
13530 if (complain & tf_error)
13531 error ("%qT resolves to %qT, which is not an enumeration type",
13534 return error_mark_node;
13536 else if (TYPENAME_IS_CLASS_P (t) && !CLASS_TYPE_P (f))
13538 if (complain & tf_error)
13539 error ("%qT resolves to %qT, which is is not a class type",
13542 return error_mark_node;
13546 return cp_build_qualified_type_real
13547 (f, cp_type_quals (f) | cp_type_quals (t), complain);
13550 case UNBOUND_CLASS_TEMPLATE:
13552 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
13553 in_decl, /*entering_scope=*/1);
13554 tree name = TYPE_IDENTIFIER (t);
13555 tree parm_list = DECL_TEMPLATE_PARMS (TYPE_NAME (t));
13557 if (ctx == error_mark_node || name == error_mark_node)
13558 return error_mark_node;
13561 parm_list = tsubst_template_parms (parm_list, args, complain);
13562 return make_unbound_class_template (ctx, name, parm_list, complain);
13569 ++cp_unevaluated_operand;
13570 ++c_inhibit_evaluation_warnings;
13572 type = tsubst_expr (TYPEOF_TYPE_EXPR (t), args,
13574 /*integral_constant_expression_p=*/false);
13576 --cp_unevaluated_operand;
13577 --c_inhibit_evaluation_warnings;
13579 type = finish_typeof (type);
13580 return cp_build_qualified_type_real (type,
13582 | cp_type_quals (type),
13586 case DECLTYPE_TYPE:
13590 ++cp_unevaluated_operand;
13591 ++c_inhibit_evaluation_warnings;
13593 type = tsubst_copy_and_build (DECLTYPE_TYPE_EXPR (t), args,
13594 complain|tf_decltype, in_decl,
13595 /*function_p*/false,
13596 /*integral_constant_expression*/false);
13598 --cp_unevaluated_operand;
13599 --c_inhibit_evaluation_warnings;
13601 if (DECLTYPE_FOR_LAMBDA_CAPTURE (t))
13602 type = lambda_capture_field_type (type,
13603 DECLTYPE_FOR_INIT_CAPTURE (t));
13604 else if (DECLTYPE_FOR_LAMBDA_PROXY (t))
13605 type = lambda_proxy_type (type);
13608 bool id = DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t);
13609 if (id && TREE_CODE (DECLTYPE_TYPE_EXPR (t)) == BIT_NOT_EXPR
13611 /* In a template ~id could be either a complement expression
13612 or an unqualified-id naming a destructor; if instantiating
13613 it produces an expression, it's not an id-expression or
13616 type = finish_decltype_type (type, id, complain);
13618 return cp_build_qualified_type_real (type,
13620 | cp_type_quals (type),
13621 complain | tf_ignore_bad_quals);
13624 case UNDERLYING_TYPE:
13626 tree type = tsubst (UNDERLYING_TYPE_TYPE (t), args,
13627 complain, in_decl);
13628 return finish_underlying_type (type);
13631 case TYPE_ARGUMENT_PACK:
13632 case NONTYPE_ARGUMENT_PACK:
13634 tree r = TYPE_P (t) ? cxx_make_type (code) : make_node (code);
13636 tsubst_template_args (ARGUMENT_PACK_ARGS (t),
13640 SET_ARGUMENT_PACK_ARGS (r, packed_out);
13642 /* For template nontype argument packs, also substitute into
13644 if (code == NONTYPE_ARGUMENT_PACK)
13645 TREE_TYPE (r) = tsubst (TREE_TYPE (t), args, complain, in_decl);
13664 /* We should use one of the expression tsubsts for these codes. */
13665 gcc_unreachable ();
13668 sorry ("use of %qs in template", get_tree_code_name (code));
13669 return error_mark_node;
13673 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
13674 type of the expression on the left-hand side of the "." or "->"
13678 tsubst_baselink (tree baselink, tree object_type,
13679 tree args, tsubst_flags_t complain, tree in_decl)
13682 tree qualifying_scope;
13685 tree template_args = 0;
13686 bool template_id_p = false;
13687 bool qualified = BASELINK_QUALIFIED_P (baselink);
13689 /* A baselink indicates a function from a base class. Both the
13690 BASELINK_ACCESS_BINFO and the base class referenced may
13691 indicate bases of the template class, rather than the
13692 instantiated class. In addition, lookups that were not
13693 ambiguous before may be ambiguous now. Therefore, we perform
13694 the lookup again. */
13695 qualifying_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (baselink));
13696 qualifying_scope = tsubst (qualifying_scope, args,
13697 complain, in_decl);
13698 fns = BASELINK_FUNCTIONS (baselink);
13699 optype = tsubst (BASELINK_OPTYPE (baselink), args, complain, in_decl);
13700 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
13702 template_id_p = true;
13703 template_args = TREE_OPERAND (fns, 1);
13704 fns = TREE_OPERAND (fns, 0);
13706 template_args = tsubst_template_args (template_args, args,
13707 complain, in_decl);
13709 name = DECL_NAME (get_first_fn (fns));
13710 if (IDENTIFIER_TYPENAME_P (name))
13711 name = mangle_conv_op_name_for_type (optype);
13712 baselink = lookup_fnfields (qualifying_scope, name, /*protect=*/1);
13715 if (constructor_name_p (name, qualifying_scope))
13717 if (complain & tf_error)
13718 error ("cannot call constructor %<%T::%D%> directly",
13719 qualifying_scope, name);
13721 return error_mark_node;
13724 /* If lookup found a single function, mark it as used at this
13725 point. (If it lookup found multiple functions the one selected
13726 later by overload resolution will be marked as used at that
13728 if (BASELINK_P (baselink))
13729 fns = BASELINK_FUNCTIONS (baselink);
13730 if (!template_id_p && !really_overloaded_fn (fns)
13731 && !mark_used (OVL_CURRENT (fns), complain) && !(complain & tf_error))
13732 return error_mark_node;
13734 /* Add back the template arguments, if present. */
13735 if (BASELINK_P (baselink) && template_id_p)
13736 BASELINK_FUNCTIONS (baselink)
13737 = build2 (TEMPLATE_ID_EXPR,
13739 BASELINK_FUNCTIONS (baselink),
13741 /* Update the conversion operator type. */
13742 BASELINK_OPTYPE (baselink) = optype;
13745 object_type = current_class_type;
13747 if (qualified || name == complete_dtor_identifier)
13749 baselink = adjust_result_of_qualified_name_lookup (baselink,
13753 /* We need to call adjust_result_of_qualified_name_lookup in case the
13754 destructor names a base class, but we unset BASELINK_QUALIFIED_P
13755 so that we still get virtual function binding. */
13756 BASELINK_QUALIFIED_P (baselink) = false;
13761 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
13762 true if the qualified-id will be a postfix-expression in-and-of
13763 itself; false if more of the postfix-expression follows the
13764 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
13768 tsubst_qualified_id (tree qualified_id, tree args,
13769 tsubst_flags_t complain, tree in_decl,
13770 bool done, bool address_p)
13776 tree template_args;
13777 location_t loc = UNKNOWN_LOCATION;
13779 gcc_assert (TREE_CODE (qualified_id) == SCOPE_REF);
13781 /* Figure out what name to look up. */
13782 name = TREE_OPERAND (qualified_id, 1);
13783 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
13785 is_template = true;
13786 loc = EXPR_LOCATION (name);
13787 template_args = TREE_OPERAND (name, 1);
13789 template_args = tsubst_template_args (template_args, args,
13790 complain, in_decl);
13791 name = TREE_OPERAND (name, 0);
13795 is_template = false;
13796 template_args = NULL_TREE;
13799 /* Substitute into the qualifying scope. When there are no ARGS, we
13800 are just trying to simplify a non-dependent expression. In that
13801 case the qualifying scope may be dependent, and, in any case,
13802 substituting will not help. */
13803 scope = TREE_OPERAND (qualified_id, 0);
13806 scope = tsubst (scope, args, complain, in_decl);
13807 expr = tsubst_copy (name, args, complain, in_decl);
13812 if (dependent_scope_p (scope))
13815 expr = build_min_nt_loc (loc, TEMPLATE_ID_EXPR, expr, template_args);
13816 tree r = build_qualified_name (NULL_TREE, scope, expr,
13817 QUALIFIED_NAME_IS_TEMPLATE (qualified_id));
13818 REF_PARENTHESIZED_P (r) = REF_PARENTHESIZED_P (qualified_id);
13822 if (!BASELINK_P (name) && !DECL_P (expr))
13824 if (TREE_CODE (expr) == BIT_NOT_EXPR)
13826 /* A BIT_NOT_EXPR is used to represent a destructor. */
13827 if (!check_dtor_name (scope, TREE_OPERAND (expr, 0)))
13829 error ("qualifying type %qT does not match destructor name ~%qT",
13830 scope, TREE_OPERAND (expr, 0));
13831 expr = error_mark_node;
13834 expr = lookup_qualified_name (scope, complete_dtor_identifier,
13835 /*is_type_p=*/0, false);
13838 expr = lookup_qualified_name (scope, expr, /*is_type_p=*/0, false);
13839 if (TREE_CODE (TREE_CODE (expr) == TEMPLATE_DECL
13840 ? DECL_TEMPLATE_RESULT (expr) : expr) == TYPE_DECL)
13842 if (complain & tf_error)
13844 error ("dependent-name %qE is parsed as a non-type, but "
13845 "instantiation yields a type", qualified_id);
13846 inform (input_location, "say %<typename %E%> if a type is meant", qualified_id);
13848 return error_mark_node;
13854 check_accessibility_of_qualified_id (expr, /*object_type=*/NULL_TREE,
13856 /* Remember that there was a reference to this entity. */
13857 if (!mark_used (expr, complain) && !(complain & tf_error))
13858 return error_mark_node;
13861 if (expr == error_mark_node || TREE_CODE (expr) == TREE_LIST)
13863 if (complain & tf_error)
13864 qualified_name_lookup_error (scope,
13865 TREE_OPERAND (qualified_id, 1),
13866 expr, input_location);
13867 return error_mark_node;
13872 if (variable_template_p (expr))
13873 expr = lookup_and_finish_template_variable (expr, template_args,
13876 expr = lookup_template_function (expr, template_args);
13879 if (expr == error_mark_node && complain & tf_error)
13880 qualified_name_lookup_error (scope, TREE_OPERAND (qualified_id, 1),
13881 expr, input_location);
13882 else if (TYPE_P (scope))
13884 expr = (adjust_result_of_qualified_name_lookup
13885 (expr, scope, current_nonlambda_class_type ()));
13886 expr = (finish_qualified_id_expr
13887 (scope, expr, done, address_p && PTRMEM_OK_P (qualified_id),
13888 QUALIFIED_NAME_IS_TEMPLATE (qualified_id),
13889 /*template_arg_p=*/false, complain));
13892 /* Expressions do not generally have reference type. */
13893 if (TREE_CODE (expr) != SCOPE_REF
13894 /* However, if we're about to form a pointer-to-member, we just
13895 want the referenced member referenced. */
13896 && TREE_CODE (expr) != OFFSET_REF)
13897 expr = convert_from_reference (expr);
13899 if (REF_PARENTHESIZED_P (qualified_id))
13900 expr = force_paren_expr (expr);
13905 /* tsubst the initializer for a VAR_DECL. INIT is the unsubstituted
13906 initializer, DECL is the substituted VAR_DECL. Other arguments are as
13910 tsubst_init (tree init, tree decl, tree args,
13911 tsubst_flags_t complain, tree in_decl)
13916 init = tsubst_expr (init, args, complain, in_decl, false);
13918 if (!init && TREE_TYPE (decl) != error_mark_node)
13920 /* If we had an initializer but it
13921 instantiated to nothing,
13922 value-initialize the object. This will
13923 only occur when the initializer was a
13924 pack expansion where the parameter packs
13925 used in that expansion were of length
13927 init = build_value_init (TREE_TYPE (decl),
13929 if (TREE_CODE (init) == AGGR_INIT_EXPR)
13930 init = get_target_expr_sfinae (init, complain);
13936 /* Like tsubst, but deals with expressions. This function just replaces
13937 template parms; to finish processing the resultant expression, use
13938 tsubst_copy_and_build or tsubst_expr. */
13941 tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl)
13943 enum tree_code code;
13946 if (t == NULL_TREE || t == error_mark_node || args == NULL_TREE)
13949 code = TREE_CODE (t);
13954 r = retrieve_local_specialization (t);
13956 if (r == NULL_TREE)
13958 /* We get here for a use of 'this' in an NSDMI as part of a
13959 constructor call or as part of an aggregate initialization. */
13960 if (DECL_NAME (t) == this_identifier
13961 && ((current_function_decl
13962 && DECL_CONSTRUCTOR_P (current_function_decl))
13963 || (current_class_ref
13964 && TREE_CODE (current_class_ref) == PLACEHOLDER_EXPR)))
13965 return current_class_ptr;
13967 /* This can happen for a parameter name used later in a function
13968 declaration (such as in a late-specified return type). Just
13969 make a dummy decl, since it's only used for its type. */
13970 gcc_assert (cp_unevaluated_operand != 0);
13971 r = tsubst_decl (t, args, complain);
13972 /* Give it the template pattern as its context; its true context
13973 hasn't been instantiated yet and this is good enough for
13975 DECL_CONTEXT (r) = DECL_CONTEXT (t);
13978 if (TREE_CODE (r) == ARGUMENT_PACK_SELECT)
13979 r = ARGUMENT_PACK_SELECT_ARG (r);
13980 if (!mark_used (r, complain) && !(complain & tf_error))
13981 return error_mark_node;
13989 if (DECL_TEMPLATE_PARM_P (t))
13990 return tsubst_copy (DECL_INITIAL (t), args, complain, in_decl);
13991 /* There is no need to substitute into namespace-scope
13993 if (DECL_NAMESPACE_SCOPE_P (t))
13995 /* If ARGS is NULL, then T is known to be non-dependent. */
13996 if (args == NULL_TREE)
13997 return scalar_constant_value (t);
13999 /* Unfortunately, we cannot just call lookup_name here.
14002 template <int I> int f() {
14004 struct S { void g() { E e = a; } };
14007 When we instantiate f<7>::S::g(), say, lookup_name is not
14008 clever enough to find f<7>::a. */
14010 = tsubst_aggr_type (DECL_CONTEXT (t), args, complain, in_decl,
14011 /*entering_scope=*/0);
14013 for (v = TYPE_VALUES (enum_type);
14015 v = TREE_CHAIN (v))
14016 if (TREE_PURPOSE (v) == DECL_NAME (t))
14017 return TREE_VALUE (v);
14019 /* We didn't find the name. That should never happen; if
14020 name-lookup found it during preliminary parsing, we
14021 should find it again here during instantiation. */
14022 gcc_unreachable ();
14027 if (PACK_EXPANSION_P (TREE_TYPE (t)))
14029 /* Check for a local specialization set up by
14030 tsubst_pack_expansion. */
14031 if (tree r = retrieve_local_specialization (t))
14033 if (TREE_CODE (r) == ARGUMENT_PACK_SELECT)
14034 r = ARGUMENT_PACK_SELECT_ARG (r);
14038 /* When retrieving a capture pack from a generic lambda, remove the
14039 lambda call op's own template argument list from ARGS. Only the
14040 template arguments active for the closure type should be used to
14041 retrieve the pack specialization. */
14042 if (LAMBDA_FUNCTION_P (current_function_decl)
14043 && (template_class_depth (DECL_CONTEXT (t))
14044 != TMPL_ARGS_DEPTH (args)))
14045 args = strip_innermost_template_args (args, 1);
14047 /* Otherwise return the full NONTYPE_ARGUMENT_PACK that
14048 tsubst_decl put in the hash table. */
14049 return retrieve_specialization (t, args, 0);
14052 if (DECL_CONTEXT (t))
14056 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args, complain, in_decl,
14057 /*entering_scope=*/1);
14058 if (ctx != DECL_CONTEXT (t))
14060 tree r = lookup_field (ctx, DECL_NAME (t), 0, false);
14063 if (complain & tf_error)
14064 error ("using invalid field %qD", t);
14065 return error_mark_node;
14074 case FUNCTION_DECL:
14075 if (DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t))
14076 r = tsubst (t, args, complain, in_decl);
14077 else if (local_variable_p (t)
14078 && uses_template_parms (DECL_CONTEXT (t)))
14080 r = retrieve_local_specialization (t);
14081 if (r == NULL_TREE)
14083 /* First try name lookup to find the instantiation. */
14084 r = lookup_name (DECL_NAME (t));
14087 /* Make sure that the one we found is the one we want. */
14088 tree ctx = DECL_CONTEXT (t);
14089 if (DECL_LANG_SPECIFIC (ctx) && DECL_TEMPLATE_INFO (ctx))
14090 ctx = tsubst (ctx, args, complain, in_decl);
14091 if (ctx != DECL_CONTEXT (r))
14099 /* This can happen for a variable used in a
14100 late-specified return type of a local lambda, or for a
14101 local static or constant. Building a new VAR_DECL
14102 should be OK in all those cases. */
14103 r = tsubst_decl (t, args, complain);
14104 if (decl_maybe_constant_var_p (r))
14106 /* We can't call cp_finish_decl, so handle the
14107 initializer by hand. */
14108 tree init = tsubst_init (DECL_INITIAL (t), r, args,
14109 complain, in_decl);
14110 if (!processing_template_decl)
14111 init = maybe_constant_init (init);
14112 if (processing_template_decl
14113 ? potential_constant_expression (init)
14114 : reduced_constant_expression_p (init))
14115 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r)
14116 = TREE_CONSTANT (r) = true;
14117 DECL_INITIAL (r) = init;
14119 gcc_assert (cp_unevaluated_operand || TREE_STATIC (r)
14120 || decl_constant_var_p (r)
14121 || errorcount || sorrycount);
14122 if (!processing_template_decl
14123 && !TREE_STATIC (r))
14124 r = process_outer_var_ref (r, complain);
14126 /* Remember this for subsequent uses. */
14127 if (local_specializations)
14128 register_local_specialization (r, t);
14133 if (!mark_used (r, complain) && !(complain & tf_error))
14134 return error_mark_node;
14137 case NAMESPACE_DECL:
14141 /* An OVERLOAD will always be a non-dependent overload set; an
14142 overload set from function scope will just be represented with an
14143 IDENTIFIER_NODE, and from class scope with a BASELINK. */
14144 gcc_assert (!uses_template_parms (t));
14148 return tsubst_baselink (t, current_nonlambda_class_type (),
14149 args, complain, in_decl);
14151 case TEMPLATE_DECL:
14152 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
14153 return tsubst (TREE_TYPE (DECL_TEMPLATE_RESULT (t)),
14154 args, complain, in_decl);
14155 else if (DECL_FUNCTION_TEMPLATE_P (t) && DECL_MEMBER_TEMPLATE_P (t))
14156 return tsubst (t, args, complain, in_decl);
14157 else if (DECL_CLASS_SCOPE_P (t)
14158 && uses_template_parms (DECL_CONTEXT (t)))
14160 /* Template template argument like the following example need
14163 template <template <class> class TT> struct C {};
14164 template <class T> struct D {
14165 template <class U> struct E {};
14170 We are processing the template argument `E' in #1 for
14171 the template instantiation #2. Originally, `E' is a
14172 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
14173 have to substitute this with one having context `D<int>'. */
14175 tree context = tsubst (DECL_CONTEXT (t), args, complain, in_decl);
14176 return lookup_field (context, DECL_NAME(t), 0, false);
14179 /* Ordinary template template argument. */
14183 case REINTERPRET_CAST_EXPR:
14184 case CONST_CAST_EXPR:
14185 case STATIC_CAST_EXPR:
14186 case DYNAMIC_CAST_EXPR:
14187 case IMPLICIT_CONV_EXPR:
14191 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
14192 tree op0 = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
14193 return build1 (code, type, op0);
14197 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0))
14198 || ARGUMENT_PACK_P (TREE_OPERAND (t, 0)))
14200 tree expanded, op = TREE_OPERAND (t, 0);
14203 if (SIZEOF_EXPR_TYPE_P (t))
14204 op = TREE_TYPE (op);
14206 ++cp_unevaluated_operand;
14207 ++c_inhibit_evaluation_warnings;
14208 /* We only want to compute the number of arguments. */
14209 if (PACK_EXPANSION_P (op))
14210 expanded = tsubst_pack_expansion (op, args, complain, in_decl);
14212 expanded = tsubst_template_args (ARGUMENT_PACK_ARGS (op),
14213 args, complain, in_decl);
14214 --cp_unevaluated_operand;
14215 --c_inhibit_evaluation_warnings;
14217 if (TREE_CODE (expanded) == TREE_VEC)
14219 len = TREE_VEC_LENGTH (expanded);
14220 /* Set TREE_USED for the benefit of -Wunused. */
14221 for (int i = 0; i < len; i++)
14222 if (DECL_P (TREE_VEC_ELT (expanded, i)))
14223 TREE_USED (TREE_VEC_ELT (expanded, i)) = true;
14226 if (expanded == error_mark_node)
14227 return error_mark_node;
14228 else if (PACK_EXPANSION_P (expanded)
14229 || (TREE_CODE (expanded) == TREE_VEC
14230 && pack_expansion_args_count (expanded)))
14233 if (PACK_EXPANSION_P (expanded))
14235 else if (TREE_VEC_LENGTH (expanded) == 1)
14236 expanded = TREE_VEC_ELT (expanded, 0);
14238 expanded = make_argument_pack (expanded);
14240 if (TYPE_P (expanded))
14241 return cxx_sizeof_or_alignof_type (expanded, SIZEOF_EXPR,
14242 complain & tf_error);
14244 return cxx_sizeof_or_alignof_expr (expanded, SIZEOF_EXPR,
14245 complain & tf_error);
14248 return build_int_cst (size_type_node, len);
14250 if (SIZEOF_EXPR_TYPE_P (t))
14252 r = tsubst (TREE_TYPE (TREE_OPERAND (t, 0)),
14253 args, complain, in_decl);
14254 r = build1 (NOP_EXPR, r, error_mark_node);
14255 r = build1 (SIZEOF_EXPR,
14256 tsubst (TREE_TYPE (t), args, complain, in_decl), r);
14257 SIZEOF_EXPR_TYPE_P (r) = 1;
14264 case TRUTH_NOT_EXPR:
14267 case UNARY_PLUS_EXPR: /* Unary + */
14269 case AT_ENCODE_EXPR:
14273 case REALPART_EXPR:
14274 case IMAGPART_EXPR:
14277 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
14278 tree op0 = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
14279 return build1 (code, type, op0);
14282 case COMPONENT_REF:
14287 object = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
14288 name = TREE_OPERAND (t, 1);
14289 if (TREE_CODE (name) == BIT_NOT_EXPR)
14291 name = tsubst_copy (TREE_OPERAND (name, 0), args,
14292 complain, in_decl);
14293 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
14295 else if (TREE_CODE (name) == SCOPE_REF
14296 && TREE_CODE (TREE_OPERAND (name, 1)) == BIT_NOT_EXPR)
14298 tree base = tsubst_copy (TREE_OPERAND (name, 0), args,
14299 complain, in_decl);
14300 name = TREE_OPERAND (name, 1);
14301 name = tsubst_copy (TREE_OPERAND (name, 0), args,
14302 complain, in_decl);
14303 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
14304 name = build_qualified_name (/*type=*/NULL_TREE,
14306 /*template_p=*/false);
14308 else if (BASELINK_P (name))
14309 name = tsubst_baselink (name,
14310 non_reference (TREE_TYPE (object)),
14314 name = tsubst_copy (name, args, complain, in_decl);
14315 return build_nt (COMPONENT_REF, object, name, NULL_TREE);
14321 case TRUNC_DIV_EXPR:
14322 case CEIL_DIV_EXPR:
14323 case FLOOR_DIV_EXPR:
14324 case ROUND_DIV_EXPR:
14325 case EXACT_DIV_EXPR:
14329 case TRUNC_MOD_EXPR:
14330 case FLOOR_MOD_EXPR:
14331 case TRUTH_ANDIF_EXPR:
14332 case TRUTH_ORIF_EXPR:
14333 case TRUTH_AND_EXPR:
14334 case TRUTH_OR_EXPR:
14347 case COMPOUND_EXPR:
14350 case PREDECREMENT_EXPR:
14351 case PREINCREMENT_EXPR:
14352 case POSTDECREMENT_EXPR:
14353 case POSTINCREMENT_EXPR:
14355 tree op0 = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
14356 tree op1 = tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl);
14357 return build_nt (code, op0, op1);
14362 tree op0 = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
14363 tree op1 = tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl);
14364 return build_qualified_name (/*type=*/NULL_TREE, op0, op1,
14365 QUALIFIED_NAME_IS_TEMPLATE (t));
14370 tree op0 = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
14371 tree op1 = tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl);
14372 return build_nt (ARRAY_REF, op0, op1, NULL_TREE, NULL_TREE);
14377 int n = VL_EXP_OPERAND_LENGTH (t);
14378 tree result = build_vl_exp (CALL_EXPR, n);
14380 for (i = 0; i < n; i++)
14381 TREE_OPERAND (t, i) = tsubst_copy (TREE_OPERAND (t, i), args,
14382 complain, in_decl);
14388 case PSEUDO_DTOR_EXPR:
14389 case VEC_PERM_EXPR:
14391 tree op0 = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
14392 tree op1 = tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl);
14393 tree op2 = tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl);
14394 r = build_nt (code, op0, op1, op2);
14395 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
14401 tree op0 = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
14402 tree op1 = tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl);
14403 tree op2 = tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl);
14404 r = build_nt (code, op0, op1, op2);
14405 NEW_EXPR_USE_GLOBAL (r) = NEW_EXPR_USE_GLOBAL (t);
14411 tree op0 = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
14412 tree op1 = tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl);
14413 r = build_nt (code, op0, op1);
14414 DELETE_EXPR_USE_GLOBAL (r) = DELETE_EXPR_USE_GLOBAL (t);
14415 DELETE_EXPR_USE_VEC (r) = DELETE_EXPR_USE_VEC (t);
14419 case TEMPLATE_ID_EXPR:
14421 /* Substituted template arguments */
14422 tree fn = TREE_OPERAND (t, 0);
14423 tree targs = TREE_OPERAND (t, 1);
14425 fn = tsubst_copy (fn, args, complain, in_decl);
14427 targs = tsubst_template_args (targs, args, complain, in_decl);
14429 return lookup_template_function (fn, targs);
14434 tree purpose, value, chain;
14436 if (t == void_list_node)
14439 purpose = TREE_PURPOSE (t);
14441 purpose = tsubst_copy (purpose, args, complain, in_decl);
14442 value = TREE_VALUE (t);
14444 value = tsubst_copy (value, args, complain, in_decl);
14445 chain = TREE_CHAIN (t);
14446 if (chain && chain != void_type_node)
14447 chain = tsubst_copy (chain, args, complain, in_decl);
14448 if (purpose == TREE_PURPOSE (t)
14449 && value == TREE_VALUE (t)
14450 && chain == TREE_CHAIN (t))
14452 return tree_cons (purpose, value, chain);
14457 case ENUMERAL_TYPE:
14459 case TEMPLATE_TYPE_PARM:
14460 case TEMPLATE_TEMPLATE_PARM:
14461 case BOUND_TEMPLATE_TEMPLATE_PARM:
14462 case TEMPLATE_PARM_INDEX:
14464 case REFERENCE_TYPE:
14466 case FUNCTION_TYPE:
14469 case TYPENAME_TYPE:
14470 case UNBOUND_CLASS_TEMPLATE:
14472 case DECLTYPE_TYPE:
14474 return tsubst (t, args, complain, in_decl);
14478 /* Fall through. */
14479 case IDENTIFIER_NODE:
14480 if (IDENTIFIER_TYPENAME_P (t))
14482 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
14483 return mangle_conv_op_name_for_type (new_type);
14489 /* This is handled by tsubst_copy_and_build. */
14490 gcc_unreachable ();
14494 tree op0 = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
14495 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
14496 return build_x_va_arg (EXPR_LOCATION (t), op0, type);
14499 case CLEANUP_POINT_EXPR:
14500 /* We shouldn't have built any of these during initial template
14501 generation. Instead, they should be built during instantiation
14502 in response to the saved STMT_IS_FULL_EXPR_P setting. */
14503 gcc_unreachable ();
14507 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
14508 tree op0 = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
14509 tree op1 = tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl);
14510 r = build2 (code, type, op0, op1);
14511 PTRMEM_OK_P (r) = PTRMEM_OK_P (t);
14512 if (!mark_used (TREE_OPERAND (r, 1), complain)
14513 && !(complain & tf_error))
14514 return error_mark_node;
14518 case EXPR_PACK_EXPANSION:
14519 error ("invalid use of pack expansion expression");
14520 return error_mark_node;
14522 case NONTYPE_ARGUMENT_PACK:
14523 error ("use %<...%> to expand argument pack");
14524 return error_mark_node;
14527 gcc_checking_assert (t == void_node && VOID_TYPE_P (TREE_TYPE (t)));
14535 /* Instantiate any typedefs in the type. */
14536 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
14537 r = fold_convert (type, t);
14538 gcc_assert (TREE_CODE (r) == code);
14543 /* These can sometimes show up in a partial instantiation, but never
14544 involve template parms. */
14545 gcc_assert (!uses_template_parms (t));
14548 case UNARY_LEFT_FOLD_EXPR:
14549 return tsubst_unary_left_fold (t, args, complain, in_decl);
14550 case UNARY_RIGHT_FOLD_EXPR:
14551 return tsubst_unary_right_fold (t, args, complain, in_decl);
14552 case BINARY_LEFT_FOLD_EXPR:
14553 return tsubst_binary_left_fold (t, args, complain, in_decl);
14554 case BINARY_RIGHT_FOLD_EXPR:
14555 return tsubst_binary_right_fold (t, args, complain, in_decl);
14558 /* We shouldn't get here, but keep going if !flag_checking. */
14560 gcc_unreachable ();
14565 /* Helper function for tsubst_omp_clauses, used for instantiation of
14566 OMP_CLAUSE_DECL of clauses. */
14569 tsubst_omp_clause_decl (tree decl, tree args, tsubst_flags_t complain,
14572 if (decl == NULL_TREE)
14575 /* Handle an OpenMP array section represented as a TREE_LIST (or
14576 OMP_CLAUSE_DEPEND_KIND). An OMP_CLAUSE_DEPEND (with a depend
14577 kind of OMP_CLAUSE_DEPEND_SINK) can also be represented as a
14578 TREE_LIST. We can handle it exactly the same as an array section
14579 (purpose, value, and a chain), even though the nomenclature
14580 (low_bound, length, etc) is different. */
14581 if (TREE_CODE (decl) == TREE_LIST)
14584 = tsubst_expr (TREE_PURPOSE (decl), args, complain, in_decl,
14585 /*integral_constant_expression_p=*/false);
14586 tree length = tsubst_expr (TREE_VALUE (decl), args, complain, in_decl,
14587 /*integral_constant_expression_p=*/false);
14588 tree chain = tsubst_omp_clause_decl (TREE_CHAIN (decl), args, complain,
14590 if (TREE_PURPOSE (decl) == low_bound
14591 && TREE_VALUE (decl) == length
14592 && TREE_CHAIN (decl) == chain)
14594 tree ret = tree_cons (low_bound, length, chain);
14595 OMP_CLAUSE_DEPEND_SINK_NEGATIVE (ret)
14596 = OMP_CLAUSE_DEPEND_SINK_NEGATIVE (decl);
14599 tree ret = tsubst_expr (decl, args, complain, in_decl,
14600 /*integral_constant_expression_p=*/false);
14601 /* Undo convert_from_reference tsubst_expr could have called. */
14603 && REFERENCE_REF_P (ret)
14604 && !REFERENCE_REF_P (decl))
14605 ret = TREE_OPERAND (ret, 0);
14609 /* Like tsubst_copy, but specifically for OpenMP clauses. */
14612 tsubst_omp_clauses (tree clauses, bool declare_simd, bool allow_fields,
14613 tree args, tsubst_flags_t complain, tree in_decl)
14615 tree new_clauses = NULL_TREE, nc, oc;
14616 tree linear_no_step = NULL_TREE;
14618 for (oc = clauses; oc ; oc = OMP_CLAUSE_CHAIN (oc))
14620 nc = copy_node (oc);
14621 OMP_CLAUSE_CHAIN (nc) = new_clauses;
14624 switch (OMP_CLAUSE_CODE (nc))
14626 case OMP_CLAUSE_LASTPRIVATE:
14627 if (OMP_CLAUSE_LASTPRIVATE_STMT (oc))
14629 OMP_CLAUSE_LASTPRIVATE_STMT (nc) = push_stmt_list ();
14630 tsubst_expr (OMP_CLAUSE_LASTPRIVATE_STMT (oc), args, complain,
14631 in_decl, /*integral_constant_expression_p=*/false);
14632 OMP_CLAUSE_LASTPRIVATE_STMT (nc)
14633 = pop_stmt_list (OMP_CLAUSE_LASTPRIVATE_STMT (nc));
14636 case OMP_CLAUSE_PRIVATE:
14637 case OMP_CLAUSE_SHARED:
14638 case OMP_CLAUSE_FIRSTPRIVATE:
14639 case OMP_CLAUSE_COPYIN:
14640 case OMP_CLAUSE_COPYPRIVATE:
14641 case OMP_CLAUSE_UNIFORM:
14642 case OMP_CLAUSE_DEPEND:
14643 case OMP_CLAUSE_FROM:
14644 case OMP_CLAUSE_TO:
14645 case OMP_CLAUSE_MAP:
14646 case OMP_CLAUSE_USE_DEVICE_PTR:
14647 case OMP_CLAUSE_IS_DEVICE_PTR:
14648 OMP_CLAUSE_DECL (nc)
14649 = tsubst_omp_clause_decl (OMP_CLAUSE_DECL (oc), args, complain,
14652 case OMP_CLAUSE_IF:
14653 case OMP_CLAUSE_NUM_THREADS:
14654 case OMP_CLAUSE_SCHEDULE:
14655 case OMP_CLAUSE_COLLAPSE:
14656 case OMP_CLAUSE_FINAL:
14657 case OMP_CLAUSE_DEVICE:
14658 case OMP_CLAUSE_DIST_SCHEDULE:
14659 case OMP_CLAUSE_NUM_TEAMS:
14660 case OMP_CLAUSE_THREAD_LIMIT:
14661 case OMP_CLAUSE_SAFELEN:
14662 case OMP_CLAUSE_SIMDLEN:
14663 case OMP_CLAUSE_NUM_TASKS:
14664 case OMP_CLAUSE_GRAINSIZE:
14665 case OMP_CLAUSE_PRIORITY:
14666 case OMP_CLAUSE_ORDERED:
14667 case OMP_CLAUSE_HINT:
14668 case OMP_CLAUSE_NUM_GANGS:
14669 case OMP_CLAUSE_NUM_WORKERS:
14670 case OMP_CLAUSE_VECTOR_LENGTH:
14671 case OMP_CLAUSE_WORKER:
14672 case OMP_CLAUSE_VECTOR:
14673 case OMP_CLAUSE_ASYNC:
14674 case OMP_CLAUSE_WAIT:
14675 OMP_CLAUSE_OPERAND (nc, 0)
14676 = tsubst_expr (OMP_CLAUSE_OPERAND (oc, 0), args, complain,
14677 in_decl, /*integral_constant_expression_p=*/false);
14679 case OMP_CLAUSE_REDUCTION:
14680 if (OMP_CLAUSE_REDUCTION_PLACEHOLDER (oc))
14682 tree placeholder = OMP_CLAUSE_REDUCTION_PLACEHOLDER (oc);
14683 if (TREE_CODE (placeholder) == SCOPE_REF)
14685 tree scope = tsubst (TREE_OPERAND (placeholder, 0), args,
14686 complain, in_decl);
14687 OMP_CLAUSE_REDUCTION_PLACEHOLDER (nc)
14688 = build_qualified_name (NULL_TREE, scope,
14689 TREE_OPERAND (placeholder, 1),
14693 gcc_assert (identifier_p (placeholder));
14695 OMP_CLAUSE_DECL (nc)
14696 = tsubst_omp_clause_decl (OMP_CLAUSE_DECL (oc), args, complain,
14699 case OMP_CLAUSE_GANG:
14700 case OMP_CLAUSE_ALIGNED:
14701 OMP_CLAUSE_DECL (nc)
14702 = tsubst_omp_clause_decl (OMP_CLAUSE_DECL (oc), args, complain,
14704 OMP_CLAUSE_OPERAND (nc, 1)
14705 = tsubst_expr (OMP_CLAUSE_OPERAND (oc, 1), args, complain,
14706 in_decl, /*integral_constant_expression_p=*/false);
14708 case OMP_CLAUSE_LINEAR:
14709 OMP_CLAUSE_DECL (nc)
14710 = tsubst_omp_clause_decl (OMP_CLAUSE_DECL (oc), args, complain,
14712 if (OMP_CLAUSE_LINEAR_STEP (oc) == NULL_TREE)
14714 gcc_assert (!linear_no_step);
14715 linear_no_step = nc;
14717 else if (OMP_CLAUSE_LINEAR_VARIABLE_STRIDE (oc))
14718 OMP_CLAUSE_LINEAR_STEP (nc)
14719 = tsubst_omp_clause_decl (OMP_CLAUSE_LINEAR_STEP (oc), args,
14720 complain, in_decl);
14722 OMP_CLAUSE_LINEAR_STEP (nc)
14723 = tsubst_expr (OMP_CLAUSE_LINEAR_STEP (oc), args, complain,
14725 /*integral_constant_expression_p=*/false);
14727 case OMP_CLAUSE_NOWAIT:
14728 case OMP_CLAUSE_DEFAULT:
14729 case OMP_CLAUSE_UNTIED:
14730 case OMP_CLAUSE_MERGEABLE:
14731 case OMP_CLAUSE_INBRANCH:
14732 case OMP_CLAUSE_NOTINBRANCH:
14733 case OMP_CLAUSE_PROC_BIND:
14734 case OMP_CLAUSE_FOR:
14735 case OMP_CLAUSE_PARALLEL:
14736 case OMP_CLAUSE_SECTIONS:
14737 case OMP_CLAUSE_TASKGROUP:
14738 case OMP_CLAUSE_NOGROUP:
14739 case OMP_CLAUSE_THREADS:
14740 case OMP_CLAUSE_SIMD:
14741 case OMP_CLAUSE_DEFAULTMAP:
14742 case OMP_CLAUSE_INDEPENDENT:
14743 case OMP_CLAUSE_AUTO:
14744 case OMP_CLAUSE_SEQ:
14746 case OMP_CLAUSE_TILE:
14749 for (lnc = OMP_CLAUSE_TILE_LIST (nc),
14750 loc = OMP_CLAUSE_TILE_LIST (oc);
14752 loc = TREE_CHAIN (loc), lnc = TREE_CHAIN (lnc))
14754 TREE_VALUE (lnc) = tsubst_expr (TREE_VALUE (loc), args,
14755 complain, in_decl, false);
14760 gcc_unreachable ();
14763 switch (OMP_CLAUSE_CODE (nc))
14765 case OMP_CLAUSE_SHARED:
14766 case OMP_CLAUSE_PRIVATE:
14767 case OMP_CLAUSE_FIRSTPRIVATE:
14768 case OMP_CLAUSE_LASTPRIVATE:
14769 case OMP_CLAUSE_COPYPRIVATE:
14770 case OMP_CLAUSE_LINEAR:
14771 case OMP_CLAUSE_REDUCTION:
14772 case OMP_CLAUSE_USE_DEVICE_PTR:
14773 case OMP_CLAUSE_IS_DEVICE_PTR:
14774 /* tsubst_expr on SCOPE_REF results in returning
14775 finish_non_static_data_member result. Undo that here. */
14776 if (TREE_CODE (OMP_CLAUSE_DECL (oc)) == SCOPE_REF
14777 && (TREE_CODE (TREE_OPERAND (OMP_CLAUSE_DECL (oc), 1))
14778 == IDENTIFIER_NODE))
14780 tree t = OMP_CLAUSE_DECL (nc);
14783 switch (TREE_CODE (v))
14785 case COMPONENT_REF:
14789 case POINTER_PLUS_EXPR:
14790 v = TREE_OPERAND (v, 0);
14793 if (DECL_CONTEXT (v) == current_function_decl
14794 && DECL_ARTIFICIAL (v)
14795 && DECL_NAME (v) == this_identifier)
14796 OMP_CLAUSE_DECL (nc) = TREE_OPERAND (t, 1);
14803 else if (VAR_P (OMP_CLAUSE_DECL (oc))
14804 && DECL_HAS_VALUE_EXPR_P (OMP_CLAUSE_DECL (oc))
14805 && DECL_ARTIFICIAL (OMP_CLAUSE_DECL (oc))
14806 && DECL_LANG_SPECIFIC (OMP_CLAUSE_DECL (oc))
14807 && DECL_OMP_PRIVATIZED_MEMBER (OMP_CLAUSE_DECL (oc)))
14809 tree decl = OMP_CLAUSE_DECL (nc);
14812 if (!DECL_LANG_SPECIFIC (decl))
14813 retrofit_lang_decl (decl);
14814 DECL_OMP_PRIVATIZED_MEMBER (decl) = 1;
14823 new_clauses = nreverse (new_clauses);
14826 new_clauses = finish_omp_clauses (new_clauses, allow_fields);
14827 if (linear_no_step)
14828 for (nc = new_clauses; nc; nc = OMP_CLAUSE_CHAIN (nc))
14829 if (nc == linear_no_step)
14831 OMP_CLAUSE_LINEAR_STEP (nc) = NULL_TREE;
14835 return new_clauses;
14838 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
14841 tsubst_copy_asm_operands (tree t, tree args, tsubst_flags_t complain,
14844 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
14846 tree purpose, value, chain;
14851 if (TREE_CODE (t) != TREE_LIST)
14852 return tsubst_copy_and_build (t, args, complain, in_decl,
14853 /*function_p=*/false,
14854 /*integral_constant_expression_p=*/false);
14856 if (t == void_list_node)
14859 purpose = TREE_PURPOSE (t);
14861 purpose = RECUR (purpose);
14862 value = TREE_VALUE (t);
14865 if (TREE_CODE (value) != LABEL_DECL)
14866 value = RECUR (value);
14869 value = lookup_label (DECL_NAME (value));
14870 gcc_assert (TREE_CODE (value) == LABEL_DECL);
14871 TREE_USED (value) = 1;
14874 chain = TREE_CHAIN (t);
14875 if (chain && chain != void_type_node)
14876 chain = RECUR (chain);
14877 return tree_cons (purpose, value, chain);
14881 /* Used to temporarily communicate the list of #pragma omp parallel
14882 clauses to #pragma omp for instantiation if they are combined
14885 static tree *omp_parallel_combined_clauses;
14887 /* Substitute one OMP_FOR iterator. */
14890 tsubst_omp_for_iterator (tree t, int i, tree declv, tree orig_declv,
14891 tree initv, tree condv, tree incrv, tree *clauses,
14892 tree args, tsubst_flags_t complain, tree in_decl,
14893 bool integral_constant_expression_p)
14895 #define RECUR(NODE) \
14896 tsubst_expr ((NODE), args, complain, in_decl, \
14897 integral_constant_expression_p)
14898 tree decl, init, cond, incr;
14900 init = TREE_VEC_ELT (OMP_FOR_INIT (t), i);
14901 gcc_assert (TREE_CODE (init) == MODIFY_EXPR);
14903 if (orig_declv && OMP_FOR_ORIG_DECLS (t))
14905 tree o = TREE_VEC_ELT (OMP_FOR_ORIG_DECLS (t), i);
14906 TREE_VEC_ELT (orig_declv, i) = RECUR (o);
14909 decl = TREE_OPERAND (init, 0);
14910 init = TREE_OPERAND (init, 1);
14911 tree decl_expr = NULL_TREE;
14912 if (init && TREE_CODE (init) == DECL_EXPR)
14914 /* We need to jump through some hoops to handle declarations in the
14915 for-init-statement, since we might need to handle auto deduction,
14916 but we need to keep control of initialization. */
14918 init = DECL_INITIAL (DECL_EXPR_DECL (init));
14919 decl = tsubst_decl (decl, args, complain);
14923 if (TREE_CODE (decl) == SCOPE_REF)
14925 decl = RECUR (decl);
14926 if (TREE_CODE (decl) == COMPONENT_REF)
14930 switch (TREE_CODE (v))
14932 case COMPONENT_REF:
14936 case POINTER_PLUS_EXPR:
14937 v = TREE_OPERAND (v, 0);
14940 if (DECL_CONTEXT (v) == current_function_decl
14941 && DECL_ARTIFICIAL (v)
14942 && DECL_NAME (v) == this_identifier)
14944 decl = TREE_OPERAND (decl, 1);
14945 decl = omp_privatize_field (decl, false);
14955 decl = RECUR (decl);
14957 init = RECUR (init);
14959 tree auto_node = type_uses_auto (TREE_TYPE (decl));
14960 if (auto_node && init)
14962 = do_auto_deduction (TREE_TYPE (decl), init, auto_node);
14964 gcc_assert (!type_dependent_expression_p (decl));
14966 if (!CLASS_TYPE_P (TREE_TYPE (decl)))
14970 /* Declare the variable, but don't let that initialize it. */
14971 tree init_sav = DECL_INITIAL (DECL_EXPR_DECL (decl_expr));
14972 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = NULL_TREE;
14974 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = init_sav;
14977 cond = RECUR (TREE_VEC_ELT (OMP_FOR_COND (t), i));
14978 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
14979 if (TREE_CODE (incr) == MODIFY_EXPR)
14981 tree lhs = RECUR (TREE_OPERAND (incr, 0));
14982 tree rhs = RECUR (TREE_OPERAND (incr, 1));
14983 incr = build_x_modify_expr (EXPR_LOCATION (incr), lhs,
14984 NOP_EXPR, rhs, complain);
14987 incr = RECUR (incr);
14988 TREE_VEC_ELT (declv, i) = decl;
14989 TREE_VEC_ELT (initv, i) = init;
14990 TREE_VEC_ELT (condv, i) = cond;
14991 TREE_VEC_ELT (incrv, i) = incr;
14997 /* Declare and initialize the variable. */
15005 for (j = (omp_parallel_combined_clauses == NULL ? 1 : 0); j < 2; j++)
15007 for (pc = j ? clauses : omp_parallel_combined_clauses; *pc; )
15009 if (OMP_CLAUSE_CODE (*pc) == OMP_CLAUSE_PRIVATE
15010 && OMP_CLAUSE_DECL (*pc) == decl)
15012 else if (OMP_CLAUSE_CODE (*pc) == OMP_CLAUSE_LASTPRIVATE
15013 && OMP_CLAUSE_DECL (*pc) == decl)
15017 /* Move lastprivate (decl) clause to OMP_FOR_CLAUSES. */
15019 *pc = OMP_CLAUSE_CHAIN (c);
15020 OMP_CLAUSE_CHAIN (c) = *clauses;
15023 else if (OMP_CLAUSE_CODE (*pc) == OMP_CLAUSE_FIRSTPRIVATE
15024 && OMP_CLAUSE_DECL (*pc) == decl)
15026 error ("iteration variable %qD should not be firstprivate",
15028 *pc = OMP_CLAUSE_CHAIN (*pc);
15030 else if (OMP_CLAUSE_CODE (*pc) == OMP_CLAUSE_REDUCTION
15031 && OMP_CLAUSE_DECL (*pc) == decl)
15033 error ("iteration variable %qD should not be reduction",
15035 *pc = OMP_CLAUSE_CHAIN (*pc);
15038 pc = &OMP_CLAUSE_CHAIN (*pc);
15043 if (*pc == NULL_TREE)
15045 tree c = build_omp_clause (input_location, OMP_CLAUSE_PRIVATE);
15046 OMP_CLAUSE_DECL (c) = decl;
15047 c = finish_omp_clauses (c, true);
15050 OMP_CLAUSE_CHAIN (c) = *clauses;
15055 cond = TREE_VEC_ELT (OMP_FOR_COND (t), i);
15056 if (COMPARISON_CLASS_P (cond))
15058 tree op0 = RECUR (TREE_OPERAND (cond, 0));
15059 tree op1 = RECUR (TREE_OPERAND (cond, 1));
15060 cond = build2 (TREE_CODE (cond), boolean_type_node, op0, op1);
15063 cond = RECUR (cond);
15064 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
15065 switch (TREE_CODE (incr))
15067 case PREINCREMENT_EXPR:
15068 case PREDECREMENT_EXPR:
15069 case POSTINCREMENT_EXPR:
15070 case POSTDECREMENT_EXPR:
15071 incr = build2 (TREE_CODE (incr), TREE_TYPE (decl),
15072 RECUR (TREE_OPERAND (incr, 0)), NULL_TREE);
15075 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
15076 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
15078 tree rhs = TREE_OPERAND (incr, 1);
15079 tree lhs = RECUR (TREE_OPERAND (incr, 0));
15080 tree rhs0 = RECUR (TREE_OPERAND (rhs, 0));
15081 tree rhs1 = RECUR (TREE_OPERAND (rhs, 1));
15082 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl), lhs,
15083 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
15087 incr = RECUR (incr);
15090 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
15091 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
15093 tree lhs = RECUR (TREE_OPERAND (incr, 0));
15094 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl), lhs,
15095 build2 (TREE_CODE (TREE_OPERAND (incr, 1)),
15096 TREE_TYPE (decl), lhs,
15097 RECUR (TREE_OPERAND (incr, 2))));
15099 else if (TREE_CODE (TREE_OPERAND (incr, 1)) == NOP_EXPR
15100 && (TREE_CODE (TREE_OPERAND (incr, 2)) == PLUS_EXPR
15101 || (TREE_CODE (TREE_OPERAND (incr, 2)) == MINUS_EXPR)))
15103 tree rhs = TREE_OPERAND (incr, 2);
15104 tree lhs = RECUR (TREE_OPERAND (incr, 0));
15105 tree rhs0 = RECUR (TREE_OPERAND (rhs, 0));
15106 tree rhs1 = RECUR (TREE_OPERAND (rhs, 1));
15107 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl), lhs,
15108 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
15112 incr = RECUR (incr);
15115 incr = RECUR (incr);
15119 TREE_VEC_ELT (declv, i) = decl;
15120 TREE_VEC_ELT (initv, i) = init;
15121 TREE_VEC_ELT (condv, i) = cond;
15122 TREE_VEC_ELT (incrv, i) = incr;
15126 /* Helper function of tsubst_expr, find OMP_TEAMS inside
15127 of OMP_TARGET's body. */
15130 tsubst_find_omp_teams (tree *tp, int *walk_subtrees, void *)
15132 *walk_subtrees = 0;
15133 switch (TREE_CODE (*tp))
15138 case STATEMENT_LIST:
15139 *walk_subtrees = 1;
15147 /* Like tsubst_copy for expressions, etc. but also does semantic
15151 tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl,
15152 bool integral_constant_expression_p)
15154 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
15155 #define RECUR(NODE) \
15156 tsubst_expr ((NODE), args, complain, in_decl, \
15157 integral_constant_expression_p)
15163 if (t == NULL_TREE || t == error_mark_node)
15166 loc = input_location;
15167 if (EXPR_HAS_LOCATION (t))
15168 input_location = EXPR_LOCATION (t);
15169 if (STATEMENT_CODE_P (TREE_CODE (t)))
15170 current_stmt_tree ()->stmts_are_full_exprs_p = STMT_IS_FULL_EXPR_P (t);
15172 switch (TREE_CODE (t))
15174 case STATEMENT_LIST:
15176 tree_stmt_iterator i;
15177 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
15178 RECUR (tsi_stmt (i));
15182 case CTOR_INITIALIZER:
15183 finish_mem_initializers (tsubst_initializer_list
15184 (TREE_OPERAND (t, 0), args));
15188 finish_return_stmt (RECUR (TREE_OPERAND (t, 0)));
15192 tmp = RECUR (EXPR_STMT_EXPR (t));
15193 if (EXPR_STMT_STMT_EXPR_RESULT (t))
15194 finish_stmt_expr_expr (tmp, cur_stmt_expr);
15196 finish_expr_stmt (tmp);
15200 do_using_directive (USING_STMT_NAMESPACE (t));
15205 tree decl, pattern_decl;
15208 pattern_decl = decl = DECL_EXPR_DECL (t);
15209 if (TREE_CODE (decl) == LABEL_DECL)
15210 finish_label_decl (DECL_NAME (decl));
15211 else if (TREE_CODE (decl) == USING_DECL)
15213 tree scope = USING_DECL_SCOPE (decl);
15214 tree name = DECL_NAME (decl);
15217 scope = tsubst (scope, args, complain, in_decl);
15218 decl = lookup_qualified_name (scope, name,
15219 /*is_type_p=*/false,
15220 /*complain=*/false);
15221 if (decl == error_mark_node || TREE_CODE (decl) == TREE_LIST)
15222 qualified_name_lookup_error (scope, name, decl, input_location);
15224 do_local_using_decl (decl, scope, name);
15226 else if (DECL_PACK_P (decl))
15228 /* Don't build up decls for a variadic capture proxy, we'll
15229 instantiate the elements directly as needed. */
15234 init = DECL_INITIAL (decl);
15235 decl = tsubst (decl, args, complain, in_decl);
15236 if (decl != error_mark_node)
15238 /* By marking the declaration as instantiated, we avoid
15239 trying to instantiate it. Since instantiate_decl can't
15240 handle local variables, and since we've already done
15241 all that needs to be done, that's the right thing to
15244 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
15246 && ANON_AGGR_TYPE_P (TREE_TYPE (decl)))
15247 /* Anonymous aggregates are a special case. */
15248 finish_anon_union (decl);
15249 else if (is_capture_proxy (DECL_EXPR_DECL (t)))
15251 DECL_CONTEXT (decl) = current_function_decl;
15252 if (DECL_NAME (decl) == this_identifier)
15254 tree lam = DECL_CONTEXT (current_function_decl);
15255 lam = CLASSTYPE_LAMBDA_EXPR (lam);
15256 LAMBDA_EXPR_THIS_CAPTURE (lam) = decl;
15258 insert_capture_proxy (decl);
15260 else if (DECL_IMPLICIT_TYPEDEF_P (t))
15261 /* We already did a pushtag. */;
15262 else if (TREE_CODE (decl) == FUNCTION_DECL
15263 && DECL_OMP_DECLARE_REDUCTION_P (decl)
15264 && DECL_FUNCTION_SCOPE_P (pattern_decl))
15266 DECL_CONTEXT (decl) = NULL_TREE;
15268 DECL_CONTEXT (decl) = current_function_decl;
15269 cp_check_omp_declare_reduction (decl);
15273 int const_init = false;
15274 maybe_push_decl (decl);
15276 && DECL_PRETTY_FUNCTION_P (decl))
15278 /* For __PRETTY_FUNCTION__ we have to adjust the
15280 const char *const name
15281 = cxx_printable_name (current_function_decl, 2);
15282 init = cp_fname_init (name, &TREE_TYPE (decl));
15285 init = tsubst_init (init, decl, args, complain, in_decl);
15288 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
15290 cp_finish_decl (decl, init, const_init, NULL_TREE, 0);
15299 stmt = begin_for_stmt (NULL_TREE, NULL_TREE);
15300 RECUR (FOR_INIT_STMT (t));
15301 finish_for_init_stmt (stmt);
15302 tmp = RECUR (FOR_COND (t));
15303 finish_for_cond (tmp, stmt, false);
15304 tmp = RECUR (FOR_EXPR (t));
15305 finish_for_expr (tmp, stmt);
15306 RECUR (FOR_BODY (t));
15307 finish_for_stmt (stmt);
15310 case RANGE_FOR_STMT:
15313 stmt = begin_for_stmt (NULL_TREE, NULL_TREE);
15314 decl = RANGE_FOR_DECL (t);
15315 decl = tsubst (decl, args, complain, in_decl);
15316 maybe_push_decl (decl);
15317 expr = RECUR (RANGE_FOR_EXPR (t));
15318 stmt = cp_convert_range_for (stmt, decl, expr, RANGE_FOR_IVDEP (t));
15319 RECUR (RANGE_FOR_BODY (t));
15320 finish_for_stmt (stmt);
15325 stmt = begin_while_stmt ();
15326 tmp = RECUR (WHILE_COND (t));
15327 finish_while_stmt_cond (tmp, stmt, false);
15328 RECUR (WHILE_BODY (t));
15329 finish_while_stmt (stmt);
15333 stmt = begin_do_stmt ();
15334 RECUR (DO_BODY (t));
15335 finish_do_body (stmt);
15336 tmp = RECUR (DO_COND (t));
15337 finish_do_stmt (tmp, stmt, false);
15341 stmt = begin_if_stmt ();
15342 tmp = RECUR (IF_COND (t));
15343 finish_if_stmt_cond (tmp, stmt);
15344 RECUR (THEN_CLAUSE (t));
15345 finish_then_clause (stmt);
15347 if (ELSE_CLAUSE (t))
15349 begin_else_clause (stmt);
15350 RECUR (ELSE_CLAUSE (t));
15351 finish_else_clause (stmt);
15354 finish_if_stmt (stmt);
15358 if (BIND_EXPR_BODY_BLOCK (t))
15359 stmt = begin_function_body ();
15361 stmt = begin_compound_stmt (BIND_EXPR_TRY_BLOCK (t)
15362 ? BCS_TRY_BLOCK : 0);
15364 RECUR (BIND_EXPR_BODY (t));
15366 if (BIND_EXPR_BODY_BLOCK (t))
15367 finish_function_body (stmt);
15369 finish_compound_stmt (stmt);
15373 finish_break_stmt ();
15376 case CONTINUE_STMT:
15377 finish_continue_stmt ();
15381 stmt = begin_switch_stmt ();
15382 tmp = RECUR (SWITCH_STMT_COND (t));
15383 finish_switch_cond (tmp, stmt);
15384 RECUR (SWITCH_STMT_BODY (t));
15385 finish_switch_stmt (stmt);
15388 case CASE_LABEL_EXPR:
15390 tree low = RECUR (CASE_LOW (t));
15391 tree high = RECUR (CASE_HIGH (t));
15392 finish_case_label (EXPR_LOCATION (t), low, high);
15398 tree decl = LABEL_EXPR_LABEL (t);
15401 label = finish_label_stmt (DECL_NAME (decl));
15402 if (DECL_ATTRIBUTES (decl) != NULL_TREE)
15403 cplus_decl_attributes (&label, DECL_ATTRIBUTES (decl), 0);
15408 tmp = GOTO_DESTINATION (t);
15409 if (TREE_CODE (tmp) != LABEL_DECL)
15410 /* Computed goto's must be tsubst'd into. On the other hand,
15411 non-computed gotos must not be; the identifier in question
15412 will have no binding. */
15415 tmp = DECL_NAME (tmp);
15416 finish_goto_stmt (tmp);
15421 tree string = RECUR (ASM_STRING (t));
15422 tree outputs = tsubst_copy_asm_operands (ASM_OUTPUTS (t), args,
15423 complain, in_decl);
15424 tree inputs = tsubst_copy_asm_operands (ASM_INPUTS (t), args,
15425 complain, in_decl);
15426 tree clobbers = tsubst_copy_asm_operands (ASM_CLOBBERS (t), args,
15427 complain, in_decl);
15428 tree labels = tsubst_copy_asm_operands (ASM_LABELS (t), args,
15429 complain, in_decl);
15430 tmp = finish_asm_stmt (ASM_VOLATILE_P (t), string, outputs, inputs,
15432 tree asm_expr = tmp;
15433 if (TREE_CODE (asm_expr) == CLEANUP_POINT_EXPR)
15434 asm_expr = TREE_OPERAND (asm_expr, 0);
15435 ASM_INPUT_P (asm_expr) = ASM_INPUT_P (t);
15442 stmt = begin_try_block ();
15443 RECUR (TRY_STMTS (t));
15444 finish_cleanup_try_block (stmt);
15445 finish_cleanup (RECUR (TRY_HANDLERS (t)), stmt);
15449 tree compound_stmt = NULL_TREE;
15451 if (FN_TRY_BLOCK_P (t))
15452 stmt = begin_function_try_block (&compound_stmt);
15454 stmt = begin_try_block ();
15456 RECUR (TRY_STMTS (t));
15458 if (FN_TRY_BLOCK_P (t))
15459 finish_function_try_block (stmt);
15461 finish_try_block (stmt);
15463 RECUR (TRY_HANDLERS (t));
15464 if (FN_TRY_BLOCK_P (t))
15465 finish_function_handler_sequence (stmt, compound_stmt);
15467 finish_handler_sequence (stmt);
15473 tree decl = HANDLER_PARMS (t);
15477 decl = tsubst (decl, args, complain, in_decl);
15478 /* Prevent instantiate_decl from trying to instantiate
15479 this variable. We've already done all that needs to be
15481 if (decl != error_mark_node)
15482 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
15484 stmt = begin_handler ();
15485 finish_handler_parms (decl, stmt);
15486 RECUR (HANDLER_BODY (t));
15487 finish_handler (stmt);
15492 tmp = tsubst (TREE_TYPE (t), args, complain, NULL_TREE);
15493 if (CLASS_TYPE_P (tmp))
15495 /* Local classes are not independent templates; they are
15496 instantiated along with their containing function. And this
15497 way we don't have to deal with pushing out of one local class
15498 to instantiate a member of another local class. */
15500 /* Closures are handled by the LAMBDA_EXPR. */
15501 gcc_assert (!LAMBDA_TYPE_P (TREE_TYPE (t)));
15502 complete_type (tmp);
15503 for (fn = TYPE_METHODS (tmp); fn; fn = DECL_CHAIN (fn))
15504 if (!DECL_ARTIFICIAL (fn))
15505 instantiate_decl (fn, /*defer_ok*/0, /*expl_inst_class*/false);
15509 case STATIC_ASSERT:
15513 ++c_inhibit_evaluation_warnings;
15515 tsubst_expr (STATIC_ASSERT_CONDITION (t),
15518 /*integral_constant_expression_p=*/true);
15519 --c_inhibit_evaluation_warnings;
15521 finish_static_assert (condition,
15522 STATIC_ASSERT_MESSAGE (t),
15523 STATIC_ASSERT_SOURCE_LOCATION (t),
15524 /*member_p=*/false);
15529 case OACC_PARALLEL:
15530 tmp = tsubst_omp_clauses (OMP_CLAUSES (t), false, false, args, complain,
15532 stmt = begin_omp_parallel ();
15533 RECUR (OMP_BODY (t));
15534 finish_omp_construct (TREE_CODE (t), stmt, tmp);
15538 r = push_omp_privatization_clauses (OMP_PARALLEL_COMBINED (t));
15539 tmp = tsubst_omp_clauses (OMP_PARALLEL_CLAUSES (t), false, true,
15540 args, complain, in_decl);
15541 if (OMP_PARALLEL_COMBINED (t))
15542 omp_parallel_combined_clauses = &tmp;
15543 stmt = begin_omp_parallel ();
15544 RECUR (OMP_PARALLEL_BODY (t));
15545 gcc_assert (omp_parallel_combined_clauses == NULL);
15546 OMP_PARALLEL_COMBINED (finish_omp_parallel (tmp, stmt))
15547 = OMP_PARALLEL_COMBINED (t);
15548 pop_omp_privatization_clauses (r);
15552 r = push_omp_privatization_clauses (false);
15553 tmp = tsubst_omp_clauses (OMP_TASK_CLAUSES (t), false, true,
15554 args, complain, in_decl);
15555 stmt = begin_omp_task ();
15556 RECUR (OMP_TASK_BODY (t));
15557 finish_omp_task (tmp, stmt);
15558 pop_omp_privatization_clauses (r);
15565 case OMP_DISTRIBUTE:
15569 tree clauses, body, pre_body;
15570 tree declv = NULL_TREE, initv = NULL_TREE, condv = NULL_TREE;
15571 tree orig_declv = NULL_TREE;
15572 tree incrv = NULL_TREE;
15575 r = push_omp_privatization_clauses (OMP_FOR_INIT (t) == NULL_TREE);
15576 clauses = tsubst_omp_clauses (OMP_FOR_CLAUSES (t), false,
15577 TREE_CODE (t) != OACC_LOOP,
15578 args, complain, in_decl);
15579 if (OMP_FOR_INIT (t) != NULL_TREE)
15581 declv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
15582 if (OMP_FOR_ORIG_DECLS (t))
15583 orig_declv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
15584 initv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
15585 condv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
15586 incrv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
15589 stmt = begin_omp_structured_block ();
15591 pre_body = push_stmt_list ();
15592 RECUR (OMP_FOR_PRE_BODY (t));
15593 pre_body = pop_stmt_list (pre_body);
15595 if (OMP_FOR_INIT (t) != NULL_TREE)
15596 for (i = 0; i < TREE_VEC_LENGTH (OMP_FOR_INIT (t)); i++)
15597 tsubst_omp_for_iterator (t, i, declv, orig_declv, initv, condv,
15598 incrv, &clauses, args, complain, in_decl,
15599 integral_constant_expression_p);
15600 omp_parallel_combined_clauses = NULL;
15602 body = push_stmt_list ();
15603 RECUR (OMP_FOR_BODY (t));
15604 body = pop_stmt_list (body);
15606 if (OMP_FOR_INIT (t) != NULL_TREE)
15607 t = finish_omp_for (EXPR_LOCATION (t), TREE_CODE (t), declv,
15608 orig_declv, initv, condv, incrv, body, pre_body,
15612 t = make_node (TREE_CODE (t));
15613 TREE_TYPE (t) = void_type_node;
15614 OMP_FOR_BODY (t) = body;
15615 OMP_FOR_PRE_BODY (t) = pre_body;
15616 OMP_FOR_CLAUSES (t) = clauses;
15617 SET_EXPR_LOCATION (t, EXPR_LOCATION (t));
15621 add_stmt (finish_omp_structured_block (stmt));
15622 pop_omp_privatization_clauses (r);
15627 omp_parallel_combined_clauses = NULL;
15632 r = push_omp_privatization_clauses (TREE_CODE (t) == OMP_TEAMS
15633 && OMP_TEAMS_COMBINED (t));
15634 tmp = tsubst_omp_clauses (OMP_CLAUSES (t), false, true,
15635 args, complain, in_decl);
15636 stmt = push_stmt_list ();
15637 RECUR (OMP_BODY (t));
15638 stmt = pop_stmt_list (stmt);
15641 OMP_BODY (t) = stmt;
15642 OMP_CLAUSES (t) = tmp;
15644 pop_omp_privatization_clauses (r);
15648 case OMP_TARGET_DATA:
15650 tmp = tsubst_omp_clauses (OMP_CLAUSES (t), false,
15651 TREE_CODE (t) != OACC_DATA,
15652 args, complain, in_decl);
15653 keep_next_level (true);
15654 stmt = begin_omp_structured_block ();
15656 RECUR (OMP_BODY (t));
15657 stmt = finish_omp_structured_block (stmt);
15660 OMP_BODY (t) = stmt;
15661 OMP_CLAUSES (t) = tmp;
15662 if (TREE_CODE (t) == OMP_TARGET && OMP_TARGET_COMBINED (t))
15664 tree teams = cp_walk_tree (&stmt, tsubst_find_omp_teams, NULL, NULL);
15667 /* For combined target teams, ensure the num_teams and
15668 thread_limit clause expressions are evaluated on the host,
15669 before entering the target construct. */
15671 for (c = OMP_TEAMS_CLAUSES (teams);
15672 c; c = OMP_CLAUSE_CHAIN (c))
15673 if ((OMP_CLAUSE_CODE (c) == OMP_CLAUSE_NUM_TEAMS
15674 || OMP_CLAUSE_CODE (c) == OMP_CLAUSE_THREAD_LIMIT)
15675 && TREE_CODE (OMP_CLAUSE_OPERAND (c, 0)) != INTEGER_CST)
15677 tree expr = OMP_CLAUSE_OPERAND (c, 0);
15678 expr = force_target_expr (TREE_TYPE (expr), expr, tf_none);
15679 if (expr == error_mark_node)
15681 tmp = TARGET_EXPR_SLOT (expr);
15683 OMP_CLAUSE_OPERAND (c, 0) = expr;
15684 tree tc = build_omp_clause (OMP_CLAUSE_LOCATION (c),
15685 OMP_CLAUSE_FIRSTPRIVATE);
15686 OMP_CLAUSE_DECL (tc) = tmp;
15687 OMP_CLAUSE_CHAIN (tc) = OMP_TARGET_CLAUSES (t);
15688 OMP_TARGET_CLAUSES (t) = tc;
15697 tmp = tsubst_omp_clauses (OACC_DECLARE_CLAUSES (t), false, false,
15698 args, complain, in_decl);
15699 OACC_DECLARE_CLAUSES (t) = tmp;
15703 case OMP_TARGET_UPDATE:
15704 case OMP_TARGET_ENTER_DATA:
15705 case OMP_TARGET_EXIT_DATA:
15706 tmp = tsubst_omp_clauses (OMP_STANDALONE_CLAUSES (t), false, true,
15707 args, complain, in_decl);
15709 OMP_STANDALONE_CLAUSES (t) = tmp;
15713 case OACC_ENTER_DATA:
15714 case OACC_EXIT_DATA:
15716 tmp = tsubst_omp_clauses (OMP_STANDALONE_CLAUSES (t), false, false,
15717 args, complain, in_decl);
15719 OMP_STANDALONE_CLAUSES (t) = tmp;
15724 tmp = tsubst_omp_clauses (OMP_ORDERED_CLAUSES (t), false, true,
15725 args, complain, in_decl);
15726 stmt = push_stmt_list ();
15727 RECUR (OMP_BODY (t));
15728 stmt = pop_stmt_list (stmt);
15731 OMP_BODY (t) = stmt;
15732 OMP_ORDERED_CLAUSES (t) = tmp;
15738 case OMP_TASKGROUP:
15739 stmt = push_stmt_list ();
15740 RECUR (OMP_BODY (t));
15741 stmt = pop_stmt_list (stmt);
15744 OMP_BODY (t) = stmt;
15749 gcc_assert (OMP_ATOMIC_DEPENDENT_P (t));
15750 if (TREE_CODE (TREE_OPERAND (t, 1)) != MODIFY_EXPR)
15752 tree op1 = TREE_OPERAND (t, 1);
15753 tree rhs1 = NULL_TREE;
15755 if (TREE_CODE (op1) == COMPOUND_EXPR)
15757 rhs1 = RECUR (TREE_OPERAND (op1, 0));
15758 op1 = TREE_OPERAND (op1, 1);
15760 lhs = RECUR (TREE_OPERAND (op1, 0));
15761 rhs = RECUR (TREE_OPERAND (op1, 1));
15762 finish_omp_atomic (OMP_ATOMIC, TREE_CODE (op1), lhs, rhs,
15763 NULL_TREE, NULL_TREE, rhs1,
15764 OMP_ATOMIC_SEQ_CST (t));
15768 tree op1 = TREE_OPERAND (t, 1);
15769 tree v = NULL_TREE, lhs, rhs = NULL_TREE, lhs1 = NULL_TREE;
15770 tree rhs1 = NULL_TREE;
15771 enum tree_code code = TREE_CODE (TREE_OPERAND (op1, 1));
15772 enum tree_code opcode = NOP_EXPR;
15773 if (code == OMP_ATOMIC_READ)
15775 v = RECUR (TREE_OPERAND (op1, 0));
15776 lhs = RECUR (TREE_OPERAND (TREE_OPERAND (op1, 1), 0));
15778 else if (code == OMP_ATOMIC_CAPTURE_OLD
15779 || code == OMP_ATOMIC_CAPTURE_NEW)
15781 tree op11 = TREE_OPERAND (TREE_OPERAND (op1, 1), 1);
15782 v = RECUR (TREE_OPERAND (op1, 0));
15783 lhs1 = RECUR (TREE_OPERAND (TREE_OPERAND (op1, 1), 0));
15784 if (TREE_CODE (op11) == COMPOUND_EXPR)
15786 rhs1 = RECUR (TREE_OPERAND (op11, 0));
15787 op11 = TREE_OPERAND (op11, 1);
15789 lhs = RECUR (TREE_OPERAND (op11, 0));
15790 rhs = RECUR (TREE_OPERAND (op11, 1));
15791 opcode = TREE_CODE (op11);
15792 if (opcode == MODIFY_EXPR)
15798 lhs = RECUR (TREE_OPERAND (op1, 0));
15799 rhs = RECUR (TREE_OPERAND (op1, 1));
15801 finish_omp_atomic (code, opcode, lhs, rhs, v, lhs1, rhs1,
15802 OMP_ATOMIC_SEQ_CST (t));
15806 case TRANSACTION_EXPR:
15809 flags |= (TRANSACTION_EXPR_OUTER (t) ? TM_STMT_ATTR_OUTER : 0);
15810 flags |= (TRANSACTION_EXPR_RELAXED (t) ? TM_STMT_ATTR_RELAXED : 0);
15812 if (TRANSACTION_EXPR_IS_STMT (t))
15814 tree body = TRANSACTION_EXPR_BODY (t);
15815 tree noex = NULL_TREE;
15816 if (TREE_CODE (body) == MUST_NOT_THROW_EXPR)
15818 noex = MUST_NOT_THROW_COND (body);
15819 if (noex == NULL_TREE)
15820 noex = boolean_true_node;
15821 body = TREE_OPERAND (body, 0);
15823 stmt = begin_transaction_stmt (input_location, NULL, flags);
15825 finish_transaction_stmt (stmt, NULL, flags, RECUR (noex));
15829 stmt = build_transaction_expr (EXPR_LOCATION (t),
15830 RECUR (TRANSACTION_EXPR_BODY (t)),
15837 case MUST_NOT_THROW_EXPR:
15839 tree op0 = RECUR (TREE_OPERAND (t, 0));
15840 tree cond = RECUR (MUST_NOT_THROW_COND (t));
15841 RETURN (build_must_not_throw_expr (op0, cond));
15844 case EXPR_PACK_EXPANSION:
15845 error ("invalid use of pack expansion expression");
15846 RETURN (error_mark_node);
15848 case NONTYPE_ARGUMENT_PACK:
15849 error ("use %<...%> to expand argument pack");
15850 RETURN (error_mark_node);
15852 case CILK_SPAWN_STMT:
15853 cfun->calls_cilk_spawn = 1;
15854 RETURN (build_cilk_spawn (EXPR_LOCATION (t), RECUR (CILK_SPAWN_FN (t))));
15856 case CILK_SYNC_STMT:
15857 RETURN (build_cilk_sync ());
15859 case COMPOUND_EXPR:
15860 tmp = RECUR (TREE_OPERAND (t, 0));
15861 if (tmp == NULL_TREE)
15862 /* If the first operand was a statement, we're done with it. */
15863 RETURN (RECUR (TREE_OPERAND (t, 1)));
15864 RETURN (build_x_compound_expr (EXPR_LOCATION (t), tmp,
15865 RECUR (TREE_OPERAND (t, 1)),
15868 case ANNOTATE_EXPR:
15869 tmp = RECUR (TREE_OPERAND (t, 0));
15870 RETURN (build2_loc (EXPR_LOCATION (t), ANNOTATE_EXPR,
15871 TREE_TYPE (tmp), tmp, RECUR (TREE_OPERAND (t, 1))));
15873 case STATEMENT_LIST_END:
15877 gcc_assert (!STATEMENT_CODE_P (TREE_CODE (t)));
15879 RETURN (tsubst_copy_and_build (t, args, complain, in_decl,
15880 /*function_p=*/false,
15881 integral_constant_expression_p));
15884 RETURN (NULL_TREE);
15886 input_location = loc;
15892 /* Instantiate the special body of the artificial DECL_OMP_DECLARE_REDUCTION
15893 function. For description of the body see comment above
15894 cp_parser_omp_declare_reduction_exprs. */
15897 tsubst_omp_udr (tree t, tree args, tsubst_flags_t complain, tree in_decl)
15899 if (t == NULL_TREE || t == error_mark_node)
15902 gcc_assert (TREE_CODE (t) == STATEMENT_LIST);
15904 tree_stmt_iterator tsi;
15907 memset (stmts, 0, sizeof stmts);
15908 for (i = 0, tsi = tsi_start (t);
15909 i < 7 && !tsi_end_p (tsi);
15910 i++, tsi_next (&tsi))
15911 stmts[i] = tsi_stmt (tsi);
15912 gcc_assert (tsi_end_p (tsi));
15916 gcc_assert (TREE_CODE (stmts[0]) == DECL_EXPR
15917 && TREE_CODE (stmts[1]) == DECL_EXPR);
15918 tree omp_out = tsubst (DECL_EXPR_DECL (stmts[0]),
15919 args, complain, in_decl);
15920 tree omp_in = tsubst (DECL_EXPR_DECL (stmts[1]),
15921 args, complain, in_decl);
15922 DECL_CONTEXT (omp_out) = current_function_decl;
15923 DECL_CONTEXT (omp_in) = current_function_decl;
15924 keep_next_level (true);
15925 tree block = begin_omp_structured_block ();
15926 tsubst_expr (stmts[2], args, complain, in_decl, false);
15927 block = finish_omp_structured_block (block);
15928 block = maybe_cleanup_point_expr_void (block);
15929 add_decl_expr (omp_out);
15930 if (TREE_NO_WARNING (DECL_EXPR_DECL (stmts[0])))
15931 TREE_NO_WARNING (omp_out) = 1;
15932 add_decl_expr (omp_in);
15933 finish_expr_stmt (block);
15937 gcc_assert (TREE_CODE (stmts[3]) == DECL_EXPR
15938 && TREE_CODE (stmts[4]) == DECL_EXPR);
15939 tree omp_priv = tsubst (DECL_EXPR_DECL (stmts[3]),
15940 args, complain, in_decl);
15941 tree omp_orig = tsubst (DECL_EXPR_DECL (stmts[4]),
15942 args, complain, in_decl);
15943 DECL_CONTEXT (omp_priv) = current_function_decl;
15944 DECL_CONTEXT (omp_orig) = current_function_decl;
15945 keep_next_level (true);
15946 tree block = begin_omp_structured_block ();
15947 tsubst_expr (stmts[5], args, complain, in_decl, false);
15948 block = finish_omp_structured_block (block);
15949 block = maybe_cleanup_point_expr_void (block);
15950 cp_walk_tree (&block, cp_remove_omp_priv_cleanup_stmt, omp_priv, NULL);
15951 add_decl_expr (omp_priv);
15952 add_decl_expr (omp_orig);
15953 finish_expr_stmt (block);
15955 add_decl_expr (omp_orig);
15959 /* T is a postfix-expression that is not being used in a function
15960 call. Return the substituted version of T. */
15963 tsubst_non_call_postfix_expression (tree t, tree args,
15964 tsubst_flags_t complain,
15967 if (TREE_CODE (t) == SCOPE_REF)
15968 t = tsubst_qualified_id (t, args, complain, in_decl,
15969 /*done=*/false, /*address_p=*/false);
15971 t = tsubst_copy_and_build (t, args, complain, in_decl,
15972 /*function_p=*/false,
15973 /*integral_constant_expression_p=*/false);
15978 /* Like tsubst but deals with expressions and performs semantic
15979 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
15982 tsubst_copy_and_build (tree t,
15984 tsubst_flags_t complain,
15987 bool integral_constant_expression_p)
15989 #define RETURN(EXP) do { retval = (EXP); goto out; } while(0)
15990 #define RECUR(NODE) \
15991 tsubst_copy_and_build (NODE, args, complain, in_decl, \
15992 /*function_p=*/false, \
15993 integral_constant_expression_p)
15998 if (t == NULL_TREE || t == error_mark_node)
16001 loc = input_location;
16002 if (EXPR_HAS_LOCATION (t))
16003 input_location = EXPR_LOCATION (t);
16005 /* N3276 decltype magic only applies to calls at the top level or on the
16006 right side of a comma. */
16007 tsubst_flags_t decltype_flag = (complain & tf_decltype);
16008 complain &= ~tf_decltype;
16010 switch (TREE_CODE (t))
16014 /* Fall through. */
16015 case IDENTIFIER_NODE:
16019 bool non_integral_constant_expression_p;
16020 const char *error_msg;
16022 if (IDENTIFIER_TYPENAME_P (t))
16024 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
16025 t = mangle_conv_op_name_for_type (new_type);
16028 /* Look up the name. */
16029 decl = lookup_name (t);
16031 /* By convention, expressions use ERROR_MARK_NODE to indicate
16032 failure, not NULL_TREE. */
16033 if (decl == NULL_TREE)
16034 decl = error_mark_node;
16036 decl = finish_id_expression (t, decl, NULL_TREE,
16038 integral_constant_expression_p,
16039 /*allow_non_integral_constant_expression_p=*/(cxx_dialect >= cxx11),
16040 &non_integral_constant_expression_p,
16041 /*template_p=*/false,
16043 /*address_p=*/false,
16044 /*template_arg_p=*/false,
16049 if (!function_p && identifier_p (decl))
16051 if (complain & tf_error)
16052 unqualified_name_lookup_error (decl);
16053 decl = error_mark_node;
16058 case TEMPLATE_ID_EXPR:
16061 tree templ = RECUR (TREE_OPERAND (t, 0));
16062 tree targs = TREE_OPERAND (t, 1);
16065 targs = tsubst_template_args (targs, args, complain, in_decl);
16066 if (targs == error_mark_node)
16067 return error_mark_node;
16069 if (variable_template_p (templ))
16070 RETURN (lookup_and_finish_template_variable (templ, targs, complain));
16072 if (TREE_CODE (templ) == COMPONENT_REF)
16074 object = TREE_OPERAND (templ, 0);
16075 templ = TREE_OPERAND (templ, 1);
16078 object = NULL_TREE;
16079 templ = lookup_template_function (templ, targs);
16082 RETURN (build3 (COMPONENT_REF, TREE_TYPE (templ),
16083 object, templ, NULL_TREE));
16085 RETURN (baselink_for_fns (templ));
16090 tree r = RECUR (TREE_OPERAND (t, 0));
16092 if (REFERENCE_REF_P (t))
16094 /* A type conversion to reference type will be enclosed in
16095 such an indirect ref, but the substitution of the cast
16096 will have also added such an indirect ref. */
16097 if (TREE_CODE (TREE_TYPE (r)) == REFERENCE_TYPE)
16098 r = convert_from_reference (r);
16101 r = build_x_indirect_ref (input_location, r, RO_UNARY_STAR,
16102 complain|decltype_flag);
16104 if (TREE_CODE (r) == INDIRECT_REF)
16105 REF_PARENTHESIZED_P (r) = REF_PARENTHESIZED_P (t);
16112 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
16113 tree op0 = RECUR (TREE_OPERAND (t, 0));
16114 RETURN (build_nop (type, op0));
16117 case IMPLICIT_CONV_EXPR:
16119 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
16120 tree expr = RECUR (TREE_OPERAND (t, 0));
16121 int flags = LOOKUP_IMPLICIT;
16122 if (IMPLICIT_CONV_EXPR_DIRECT_INIT (t))
16123 flags = LOOKUP_NORMAL;
16124 RETURN (perform_implicit_conversion_flags (type, expr, complain,
16130 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
16131 tree op0 = RECUR (TREE_OPERAND (t, 0));
16132 RETURN (build1 (CONVERT_EXPR, type, op0));
16136 case REINTERPRET_CAST_EXPR:
16137 case CONST_CAST_EXPR:
16138 case DYNAMIC_CAST_EXPR:
16139 case STATIC_CAST_EXPR:
16142 tree op, r = NULL_TREE;
16144 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
16145 if (integral_constant_expression_p
16146 && !cast_valid_in_integral_constant_expression_p (type))
16148 if (complain & tf_error)
16149 error ("a cast to a type other than an integral or "
16150 "enumeration type cannot appear in a constant-expression");
16151 RETURN (error_mark_node);
16154 op = RECUR (TREE_OPERAND (t, 0));
16156 warning_sentinel s(warn_useless_cast);
16157 switch (TREE_CODE (t))
16160 r = build_functional_cast (type, op, complain);
16162 case REINTERPRET_CAST_EXPR:
16163 r = build_reinterpret_cast (type, op, complain);
16165 case CONST_CAST_EXPR:
16166 r = build_const_cast (type, op, complain);
16168 case DYNAMIC_CAST_EXPR:
16169 r = build_dynamic_cast (type, op, complain);
16171 case STATIC_CAST_EXPR:
16172 r = build_static_cast (type, op, complain);
16175 gcc_unreachable ();
16181 case POSTDECREMENT_EXPR:
16182 case POSTINCREMENT_EXPR:
16183 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
16184 args, complain, in_decl);
16185 RETURN (build_x_unary_op (input_location, TREE_CODE (t), op1,
16186 complain|decltype_flag));
16188 case PREDECREMENT_EXPR:
16189 case PREINCREMENT_EXPR:
16193 case TRUTH_NOT_EXPR:
16194 case UNARY_PLUS_EXPR: /* Unary + */
16195 case REALPART_EXPR:
16196 case IMAGPART_EXPR:
16197 RETURN (build_x_unary_op (input_location, TREE_CODE (t),
16198 RECUR (TREE_OPERAND (t, 0)),
16199 complain|decltype_flag));
16201 case FIX_TRUNC_EXPR:
16202 RETURN (cp_build_unary_op (FIX_TRUNC_EXPR, RECUR (TREE_OPERAND (t, 0)),
16206 op1 = TREE_OPERAND (t, 0);
16207 if (TREE_CODE (op1) == LABEL_DECL)
16208 RETURN (finish_label_address_expr (DECL_NAME (op1),
16209 EXPR_LOCATION (op1)));
16210 if (TREE_CODE (op1) == SCOPE_REF)
16211 op1 = tsubst_qualified_id (op1, args, complain, in_decl,
16212 /*done=*/true, /*address_p=*/true);
16214 op1 = tsubst_non_call_postfix_expression (op1, args, complain,
16216 RETURN (build_x_unary_op (input_location, ADDR_EXPR, op1,
16217 complain|decltype_flag));
16222 case TRUNC_DIV_EXPR:
16223 case CEIL_DIV_EXPR:
16224 case FLOOR_DIV_EXPR:
16225 case ROUND_DIV_EXPR:
16226 case EXACT_DIV_EXPR:
16230 case TRUNC_MOD_EXPR:
16231 case FLOOR_MOD_EXPR:
16232 case TRUTH_ANDIF_EXPR:
16233 case TRUTH_ORIF_EXPR:
16234 case TRUTH_AND_EXPR:
16235 case TRUTH_OR_EXPR:
16251 warning_sentinel s1(warn_type_limits);
16252 warning_sentinel s2(warn_div_by_zero);
16253 warning_sentinel s3(warn_logical_op);
16254 warning_sentinel s4(warn_tautological_compare);
16255 tree op0 = RECUR (TREE_OPERAND (t, 0));
16256 tree op1 = RECUR (TREE_OPERAND (t, 1));
16257 tree r = build_x_binary_op
16258 (input_location, TREE_CODE (t),
16260 (TREE_NO_WARNING (TREE_OPERAND (t, 0))
16262 : TREE_CODE (TREE_OPERAND (t, 0))),
16264 (TREE_NO_WARNING (TREE_OPERAND (t, 1))
16266 : TREE_CODE (TREE_OPERAND (t, 1))),
16268 complain|decltype_flag);
16269 if (EXPR_P (r) && TREE_NO_WARNING (t))
16270 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
16275 case POINTER_PLUS_EXPR:
16277 tree op0 = RECUR (TREE_OPERAND (t, 0));
16278 tree op1 = RECUR (TREE_OPERAND (t, 1));
16279 return fold_build_pointer_plus (op0, op1);
16283 RETURN (tsubst_qualified_id (t, args, complain, in_decl, /*done=*/true,
16284 /*address_p=*/false));
16286 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
16287 args, complain, in_decl);
16288 RETURN (build_x_array_ref (EXPR_LOCATION (t), op1,
16289 RECUR (TREE_OPERAND (t, 1)),
16290 complain|decltype_flag));
16292 case ARRAY_NOTATION_REF:
16294 tree start_index, length, stride;
16295 op1 = tsubst_non_call_postfix_expression (ARRAY_NOTATION_ARRAY (t),
16296 args, complain, in_decl);
16297 start_index = RECUR (ARRAY_NOTATION_START (t));
16298 length = RECUR (ARRAY_NOTATION_LENGTH (t));
16299 stride = RECUR (ARRAY_NOTATION_STRIDE (t));
16300 RETURN (build_array_notation_ref (EXPR_LOCATION (t), op1, start_index,
16301 length, stride, TREE_TYPE (op1)));
16304 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0))
16305 || ARGUMENT_PACK_P (TREE_OPERAND (t, 0)))
16306 RETURN (tsubst_copy (t, args, complain, in_decl));
16313 op1 = TREE_OPERAND (t, 0);
16314 if (TREE_CODE (t) == SIZEOF_EXPR && SIZEOF_EXPR_TYPE_P (t))
16315 op1 = TREE_TYPE (op1);
16318 /* When there are no ARGS, we are trying to evaluate a
16319 non-dependent expression from the parser. Trying to do
16320 the substitutions may not work. */
16322 op1 = TREE_TYPE (op1);
16326 ++cp_unevaluated_operand;
16327 ++c_inhibit_evaluation_warnings;
16329 op1 = tsubst (op1, args, complain, in_decl);
16331 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
16332 /*function_p=*/false,
16333 /*integral_constant_expression_p=*/
16335 --cp_unevaluated_operand;
16336 --c_inhibit_evaluation_warnings;
16339 r = cxx_sizeof_or_alignof_type (op1, TREE_CODE (t),
16340 complain & tf_error);
16342 r = cxx_sizeof_or_alignof_expr (op1, TREE_CODE (t),
16343 complain & tf_error);
16344 if (TREE_CODE (t) == SIZEOF_EXPR && r != error_mark_node)
16346 if (TREE_CODE (r) != SIZEOF_EXPR || TYPE_P (op1))
16348 if (!processing_template_decl && TYPE_P (op1))
16350 r = build_min (SIZEOF_EXPR, size_type_node,
16351 build1 (NOP_EXPR, op1, error_mark_node));
16352 SIZEOF_EXPR_TYPE_P (r) = 1;
16355 r = build_min (SIZEOF_EXPR, size_type_node, op1);
16356 TREE_SIDE_EFFECTS (r) = 0;
16357 TREE_READONLY (r) = 1;
16359 SET_EXPR_LOCATION (r, EXPR_LOCATION (t));
16364 case AT_ENCODE_EXPR:
16366 op1 = TREE_OPERAND (t, 0);
16367 ++cp_unevaluated_operand;
16368 ++c_inhibit_evaluation_warnings;
16369 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
16370 /*function_p=*/false,
16371 /*integral_constant_expression_p=*/false);
16372 --cp_unevaluated_operand;
16373 --c_inhibit_evaluation_warnings;
16374 RETURN (objc_build_encode_expr (op1));
16377 case NOEXCEPT_EXPR:
16378 op1 = TREE_OPERAND (t, 0);
16379 ++cp_unevaluated_operand;
16380 ++c_inhibit_evaluation_warnings;
16381 ++cp_noexcept_operand;
16382 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
16383 /*function_p=*/false,
16384 /*integral_constant_expression_p=*/false);
16385 --cp_unevaluated_operand;
16386 --c_inhibit_evaluation_warnings;
16387 --cp_noexcept_operand;
16388 RETURN (finish_noexcept_expr (op1, complain));
16392 warning_sentinel s(warn_div_by_zero);
16393 tree lhs = RECUR (TREE_OPERAND (t, 0));
16394 tree rhs = RECUR (TREE_OPERAND (t, 2));
16395 tree r = build_x_modify_expr
16396 (EXPR_LOCATION (t), lhs, TREE_CODE (TREE_OPERAND (t, 1)), rhs,
16397 complain|decltype_flag);
16398 /* TREE_NO_WARNING must be set if either the expression was
16399 parenthesized or it uses an operator such as >>= rather
16400 than plain assignment. In the former case, it was already
16401 set and must be copied. In the latter case,
16402 build_x_modify_expr sets it and it must not be reset
16404 if (TREE_NO_WARNING (t))
16405 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
16411 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
16412 args, complain, in_decl);
16413 /* Remember that there was a reference to this entity. */
16415 && !mark_used (op1, complain) && !(complain & tf_error))
16416 RETURN (error_mark_node);
16417 RETURN (build_x_arrow (input_location, op1, complain));
16421 tree placement = RECUR (TREE_OPERAND (t, 0));
16422 tree init = RECUR (TREE_OPERAND (t, 3));
16423 vec<tree, va_gc> *placement_vec;
16424 vec<tree, va_gc> *init_vec;
16427 if (placement == NULL_TREE)
16428 placement_vec = NULL;
16431 placement_vec = make_tree_vector ();
16432 for (; placement != NULL_TREE; placement = TREE_CHAIN (placement))
16433 vec_safe_push (placement_vec, TREE_VALUE (placement));
16436 /* If there was an initializer in the original tree, but it
16437 instantiated to an empty list, then we should pass a
16438 non-NULL empty vector to tell build_new that it was an
16439 empty initializer() rather than no initializer. This can
16440 only happen when the initializer is a pack expansion whose
16441 parameter packs are of length zero. */
16442 if (init == NULL_TREE && TREE_OPERAND (t, 3) == NULL_TREE)
16446 init_vec = make_tree_vector ();
16447 if (init == void_node)
16448 gcc_assert (init_vec != NULL);
16451 for (; init != NULL_TREE; init = TREE_CHAIN (init))
16452 vec_safe_push (init_vec, TREE_VALUE (init));
16456 tree op1 = tsubst (TREE_OPERAND (t, 1), args, complain, in_decl);
16457 tree op2 = RECUR (TREE_OPERAND (t, 2));
16458 ret = build_new (&placement_vec, op1, op2, &init_vec,
16459 NEW_EXPR_USE_GLOBAL (t),
16462 if (placement_vec != NULL)
16463 release_tree_vector (placement_vec);
16464 if (init_vec != NULL)
16465 release_tree_vector (init_vec);
16472 tree op0 = RECUR (TREE_OPERAND (t, 0));
16473 tree op1 = RECUR (TREE_OPERAND (t, 1));
16474 RETURN (delete_sanity (op0, op1,
16475 DELETE_EXPR_USE_VEC (t),
16476 DELETE_EXPR_USE_GLOBAL (t),
16480 case COMPOUND_EXPR:
16482 tree op0 = tsubst_copy_and_build (TREE_OPERAND (t, 0), args,
16483 complain & ~tf_decltype, in_decl,
16484 /*function_p=*/false,
16485 integral_constant_expression_p);
16486 RETURN (build_x_compound_expr (EXPR_LOCATION (t),
16488 RECUR (TREE_OPERAND (t, 1)),
16489 complain|decltype_flag));
16495 vec<tree, va_gc> *call_args;
16496 unsigned int nargs, i;
16501 function = CALL_EXPR_FN (t);
16502 /* When we parsed the expression, we determined whether or
16503 not Koenig lookup should be performed. */
16504 koenig_p = KOENIG_LOOKUP_P (t);
16505 if (TREE_CODE (function) == SCOPE_REF)
16507 qualified_p = true;
16508 function = tsubst_qualified_id (function, args, complain, in_decl,
16510 /*address_p=*/false);
16512 else if (koenig_p && identifier_p (function))
16514 /* Do nothing; calling tsubst_copy_and_build on an identifier
16515 would incorrectly perform unqualified lookup again.
16517 Note that we can also have an IDENTIFIER_NODE if the earlier
16518 unqualified lookup found a member function; in that case
16519 koenig_p will be false and we do want to do the lookup
16520 again to find the instantiated member function.
16522 FIXME but doing that causes c++/15272, so we need to stop
16523 using IDENTIFIER_NODE in that situation. */
16524 qualified_p = false;
16528 if (TREE_CODE (function) == COMPONENT_REF)
16530 tree op = TREE_OPERAND (function, 1);
16532 qualified_p = (TREE_CODE (op) == SCOPE_REF
16533 || (BASELINK_P (op)
16534 && BASELINK_QUALIFIED_P (op)));
16537 qualified_p = false;
16539 if (TREE_CODE (function) == ADDR_EXPR
16540 && TREE_CODE (TREE_OPERAND (function, 0)) == FUNCTION_DECL)
16541 /* Avoid error about taking the address of a constructor. */
16542 function = TREE_OPERAND (function, 0);
16544 function = tsubst_copy_and_build (function, args, complain,
16547 integral_constant_expression_p);
16549 if (BASELINK_P (function))
16550 qualified_p = true;
16553 nargs = call_expr_nargs (t);
16554 call_args = make_tree_vector ();
16555 for (i = 0; i < nargs; ++i)
16557 tree arg = CALL_EXPR_ARG (t, i);
16559 if (!PACK_EXPANSION_P (arg))
16560 vec_safe_push (call_args, RECUR (CALL_EXPR_ARG (t, i)));
16563 /* Expand the pack expansion and push each entry onto
16565 arg = tsubst_pack_expansion (arg, args, complain, in_decl);
16566 if (TREE_CODE (arg) == TREE_VEC)
16568 unsigned int len, j;
16570 len = TREE_VEC_LENGTH (arg);
16571 for (j = 0; j < len; ++j)
16573 tree value = TREE_VEC_ELT (arg, j);
16574 if (value != NULL_TREE)
16575 value = convert_from_reference (value);
16576 vec_safe_push (call_args, value);
16581 /* A partial substitution. Add one entry. */
16582 vec_safe_push (call_args, arg);
16587 /* We do not perform argument-dependent lookup if normal
16588 lookup finds a non-function, in accordance with the
16589 expected resolution of DR 218. */
16591 && ((is_overloaded_fn (function)
16592 /* If lookup found a member function, the Koenig lookup is
16593 not appropriate, even if an unqualified-name was used
16594 to denote the function. */
16595 && !DECL_FUNCTION_MEMBER_P (get_first_fn (function)))
16596 || identifier_p (function))
16597 /* Only do this when substitution turns a dependent call
16598 into a non-dependent call. */
16599 && type_dependent_expression_p_push (t)
16600 && !any_type_dependent_arguments_p (call_args))
16601 function = perform_koenig_lookup (function, call_args, tf_none);
16603 if (identifier_p (function)
16604 && !any_type_dependent_arguments_p (call_args))
16606 if (koenig_p && (complain & tf_warning_or_error))
16608 /* For backwards compatibility and good diagnostics, try
16609 the unqualified lookup again if we aren't in SFINAE
16611 tree unq = (tsubst_copy_and_build
16612 (function, args, complain, in_decl, true,
16613 integral_constant_expression_p));
16614 if (unq == error_mark_node)
16615 RETURN (error_mark_node);
16617 if (unq != function)
16620 if (INDIRECT_REF_P (fn))
16621 fn = TREE_OPERAND (fn, 0);
16622 if (TREE_CODE (fn) == COMPONENT_REF)
16623 fn = TREE_OPERAND (fn, 1);
16624 if (is_overloaded_fn (fn))
16625 fn = get_first_fn (fn);
16626 if (permerror (EXPR_LOC_OR_LOC (t, input_location),
16627 "%qD was not declared in this scope, "
16628 "and no declarations were found by "
16629 "argument-dependent lookup at the point "
16630 "of instantiation", function))
16633 /* Can't say anything more. */;
16634 else if (DECL_CLASS_SCOPE_P (fn))
16636 location_t loc = EXPR_LOC_OR_LOC (t,
16639 "declarations in dependent base %qT are "
16640 "not found by unqualified lookup",
16641 DECL_CLASS_CONTEXT (fn));
16642 if (current_class_ptr)
16644 "use %<this->%D%> instead", function);
16647 "use %<%T::%D%> instead",
16648 current_class_name, function);
16651 inform (DECL_SOURCE_LOCATION (fn),
16652 "%qD declared here, later in the "
16653 "translation unit", fn);
16658 if (identifier_p (function))
16660 if (complain & tf_error)
16661 unqualified_name_lookup_error (function);
16662 release_tree_vector (call_args);
16663 RETURN (error_mark_node);
16667 /* Remember that there was a reference to this entity. */
16668 if (DECL_P (function)
16669 && !mark_used (function, complain) && !(complain & tf_error))
16670 RETURN (error_mark_node);
16672 /* Put back tf_decltype for the actual call. */
16673 complain |= decltype_flag;
16675 if (TREE_CODE (function) == OFFSET_REF)
16676 ret = build_offset_ref_call_from_tree (function, &call_args,
16678 else if (TREE_CODE (function) == COMPONENT_REF)
16680 tree instance = TREE_OPERAND (function, 0);
16681 tree fn = TREE_OPERAND (function, 1);
16683 if (processing_template_decl
16684 && (type_dependent_expression_p (instance)
16685 || (!BASELINK_P (fn)
16686 && TREE_CODE (fn) != FIELD_DECL)
16687 || type_dependent_expression_p (fn)
16688 || any_type_dependent_arguments_p (call_args)))
16689 ret = build_nt_call_vec (function, call_args);
16690 else if (!BASELINK_P (fn))
16691 ret = finish_call_expr (function, &call_args,
16692 /*disallow_virtual=*/false,
16693 /*koenig_p=*/false,
16696 ret = (build_new_method_call
16698 &call_args, NULL_TREE,
16699 qualified_p ? LOOKUP_NONVIRTUAL : LOOKUP_NORMAL,
16704 ret = finish_call_expr (function, &call_args,
16705 /*disallow_virtual=*/qualified_p,
16709 release_tree_vector (call_args);
16716 tree cond = RECUR (TREE_OPERAND (t, 0));
16717 tree folded_cond = fold_non_dependent_expr (cond);
16720 if (TREE_CODE (folded_cond) == INTEGER_CST)
16722 if (integer_zerop (folded_cond))
16724 ++c_inhibit_evaluation_warnings;
16725 exp1 = RECUR (TREE_OPERAND (t, 1));
16726 --c_inhibit_evaluation_warnings;
16727 exp2 = RECUR (TREE_OPERAND (t, 2));
16731 exp1 = RECUR (TREE_OPERAND (t, 1));
16732 ++c_inhibit_evaluation_warnings;
16733 exp2 = RECUR (TREE_OPERAND (t, 2));
16734 --c_inhibit_evaluation_warnings;
16736 cond = folded_cond;
16740 exp1 = RECUR (TREE_OPERAND (t, 1));
16741 exp2 = RECUR (TREE_OPERAND (t, 2));
16744 RETURN (build_x_conditional_expr (EXPR_LOCATION (t),
16745 cond, exp1, exp2, complain));
16748 case PSEUDO_DTOR_EXPR:
16750 tree op0 = RECUR (TREE_OPERAND (t, 0));
16751 tree op1 = RECUR (TREE_OPERAND (t, 1));
16752 tree op2 = tsubst (TREE_OPERAND (t, 2), args, complain, in_decl);
16753 RETURN (finish_pseudo_destructor_expr (op0, op1, op2,
16759 tree purpose, value, chain;
16761 if (t == void_list_node)
16764 if ((TREE_PURPOSE (t) && PACK_EXPANSION_P (TREE_PURPOSE (t)))
16765 || (TREE_VALUE (t) && PACK_EXPANSION_P (TREE_VALUE (t))))
16767 /* We have pack expansions, so expand those and
16768 create a new list out of it. */
16769 tree purposevec = NULL_TREE;
16770 tree valuevec = NULL_TREE;
16774 /* Expand the argument expressions. */
16775 if (TREE_PURPOSE (t))
16776 purposevec = tsubst_pack_expansion (TREE_PURPOSE (t), args,
16777 complain, in_decl);
16778 if (TREE_VALUE (t))
16779 valuevec = tsubst_pack_expansion (TREE_VALUE (t), args,
16780 complain, in_decl);
16782 /* Build the rest of the list. */
16783 chain = TREE_CHAIN (t);
16784 if (chain && chain != void_type_node)
16785 chain = RECUR (chain);
16787 /* Determine the number of arguments. */
16788 if (purposevec && TREE_CODE (purposevec) == TREE_VEC)
16790 len = TREE_VEC_LENGTH (purposevec);
16791 gcc_assert (!valuevec || len == TREE_VEC_LENGTH (valuevec));
16793 else if (TREE_CODE (valuevec) == TREE_VEC)
16794 len = TREE_VEC_LENGTH (valuevec);
16797 /* Since we only performed a partial substitution into
16798 the argument pack, we only RETURN (a single list
16800 if (purposevec == TREE_PURPOSE (t)
16801 && valuevec == TREE_VALUE (t)
16802 && chain == TREE_CHAIN (t))
16805 RETURN (tree_cons (purposevec, valuevec, chain));
16808 /* Convert the argument vectors into a TREE_LIST */
16812 /* Grab the Ith values. */
16814 purpose = purposevec ? TREE_VEC_ELT (purposevec, i)
16817 = valuevec ? convert_from_reference (TREE_VEC_ELT (valuevec, i))
16820 /* Build the list (backwards). */
16821 chain = tree_cons (purpose, value, chain);
16827 purpose = TREE_PURPOSE (t);
16829 purpose = RECUR (purpose);
16830 value = TREE_VALUE (t);
16832 value = RECUR (value);
16833 chain = TREE_CHAIN (t);
16834 if (chain && chain != void_type_node)
16835 chain = RECUR (chain);
16836 if (purpose == TREE_PURPOSE (t)
16837 && value == TREE_VALUE (t)
16838 && chain == TREE_CHAIN (t))
16840 RETURN (tree_cons (purpose, value, chain));
16843 case COMPONENT_REF:
16850 object = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
16851 args, complain, in_decl);
16852 /* Remember that there was a reference to this entity. */
16853 if (DECL_P (object)
16854 && !mark_used (object, complain) && !(complain & tf_error))
16855 RETURN (error_mark_node);
16856 object_type = TREE_TYPE (object);
16858 member = TREE_OPERAND (t, 1);
16859 if (BASELINK_P (member))
16860 member = tsubst_baselink (member,
16861 non_reference (TREE_TYPE (object)),
16862 args, complain, in_decl);
16864 member = tsubst_copy (member, args, complain, in_decl);
16865 if (member == error_mark_node)
16866 RETURN (error_mark_node);
16868 if (type_dependent_expression_p (object))
16869 /* We can't do much here. */;
16870 else if (!CLASS_TYPE_P (object_type))
16872 if (scalarish_type_p (object_type))
16874 tree s = NULL_TREE;
16875 tree dtor = member;
16877 if (TREE_CODE (dtor) == SCOPE_REF)
16879 s = TREE_OPERAND (dtor, 0);
16880 dtor = TREE_OPERAND (dtor, 1);
16882 if (TREE_CODE (dtor) == BIT_NOT_EXPR)
16884 dtor = TREE_OPERAND (dtor, 0);
16886 RETURN (finish_pseudo_destructor_expr
16887 (object, s, dtor, input_location));
16891 else if (TREE_CODE (member) == SCOPE_REF
16892 && TREE_CODE (TREE_OPERAND (member, 1)) == TEMPLATE_ID_EXPR)
16894 /* Lookup the template functions now that we know what the
16896 tree scope = TREE_OPERAND (member, 0);
16897 tree tmpl = TREE_OPERAND (TREE_OPERAND (member, 1), 0);
16898 tree args = TREE_OPERAND (TREE_OPERAND (member, 1), 1);
16899 member = lookup_qualified_name (scope, tmpl,
16900 /*is_type_p=*/false,
16901 /*complain=*/false);
16902 if (BASELINK_P (member))
16904 BASELINK_FUNCTIONS (member)
16905 = build_nt (TEMPLATE_ID_EXPR, BASELINK_FUNCTIONS (member),
16907 member = (adjust_result_of_qualified_name_lookup
16908 (member, BINFO_TYPE (BASELINK_BINFO (member)),
16913 qualified_name_lookup_error (scope, tmpl, member,
16915 RETURN (error_mark_node);
16918 else if (TREE_CODE (member) == SCOPE_REF
16919 && !CLASS_TYPE_P (TREE_OPERAND (member, 0))
16920 && TREE_CODE (TREE_OPERAND (member, 0)) != NAMESPACE_DECL)
16922 if (complain & tf_error)
16924 if (TYPE_P (TREE_OPERAND (member, 0)))
16925 error ("%qT is not a class or namespace",
16926 TREE_OPERAND (member, 0));
16928 error ("%qD is not a class or namespace",
16929 TREE_OPERAND (member, 0));
16931 RETURN (error_mark_node);
16933 else if (TREE_CODE (member) == FIELD_DECL)
16935 r = finish_non_static_data_member (member, object, NULL_TREE);
16936 if (TREE_CODE (r) == COMPONENT_REF)
16937 REF_PARENTHESIZED_P (r) = REF_PARENTHESIZED_P (t);
16941 r = finish_class_member_access_expr (object, member,
16942 /*template_p=*/false,
16944 if (TREE_CODE (r) == COMPONENT_REF)
16945 REF_PARENTHESIZED_P (r) = REF_PARENTHESIZED_P (t);
16950 RETURN (build_throw
16951 (RECUR (TREE_OPERAND (t, 0))));
16955 vec<constructor_elt, va_gc> *n;
16956 constructor_elt *ce;
16957 unsigned HOST_WIDE_INT idx;
16958 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
16959 bool process_index_p;
16961 bool need_copy_p = false;
16964 if (type == error_mark_node)
16965 RETURN (error_mark_node);
16967 /* digest_init will do the wrong thing if we let it. */
16968 if (type && TYPE_PTRMEMFUNC_P (type))
16971 /* We do not want to process the index of aggregate
16972 initializers as they are identifier nodes which will be
16973 looked up by digest_init. */
16974 process_index_p = !(type && MAYBE_CLASS_TYPE_P (type));
16976 n = vec_safe_copy (CONSTRUCTOR_ELTS (t));
16977 newlen = vec_safe_length (n);
16978 FOR_EACH_VEC_SAFE_ELT (n, idx, ce)
16980 if (ce->index && process_index_p
16981 /* An identifier index is looked up in the type
16982 being initialized, not the current scope. */
16983 && TREE_CODE (ce->index) != IDENTIFIER_NODE)
16984 ce->index = RECUR (ce->index);
16986 if (PACK_EXPANSION_P (ce->value))
16988 /* Substitute into the pack expansion. */
16989 ce->value = tsubst_pack_expansion (ce->value, args, complain,
16992 if (ce->value == error_mark_node
16993 || PACK_EXPANSION_P (ce->value))
16995 else if (TREE_VEC_LENGTH (ce->value) == 1)
16996 /* Just move the argument into place. */
16997 ce->value = TREE_VEC_ELT (ce->value, 0);
17000 /* Update the length of the final CONSTRUCTOR
17001 arguments vector, and note that we will need to
17003 newlen = newlen + TREE_VEC_LENGTH (ce->value) - 1;
17004 need_copy_p = true;
17008 ce->value = RECUR (ce->value);
17013 vec<constructor_elt, va_gc> *old_n = n;
17015 vec_alloc (n, newlen);
17016 FOR_EACH_VEC_ELT (*old_n, idx, ce)
17018 if (TREE_CODE (ce->value) == TREE_VEC)
17020 int i, len = TREE_VEC_LENGTH (ce->value);
17021 for (i = 0; i < len; ++i)
17022 CONSTRUCTOR_APPEND_ELT (n, 0,
17023 TREE_VEC_ELT (ce->value, i));
17026 CONSTRUCTOR_APPEND_ELT (n, 0, ce->value);
17030 r = build_constructor (init_list_type_node, n);
17031 CONSTRUCTOR_IS_DIRECT_INIT (r) = CONSTRUCTOR_IS_DIRECT_INIT (t);
17033 if (TREE_HAS_CONSTRUCTOR (t))
17034 RETURN (finish_compound_literal (type, r, complain));
17036 TREE_TYPE (r) = type;
17042 tree operand_0 = TREE_OPERAND (t, 0);
17043 if (TYPE_P (operand_0))
17045 operand_0 = tsubst (operand_0, args, complain, in_decl);
17046 RETURN (get_typeid (operand_0, complain));
17050 operand_0 = RECUR (operand_0);
17051 RETURN (build_typeid (operand_0, complain));
17058 else if (DECL_PACK_P (t))
17060 /* We don't build decls for an instantiation of a
17061 variadic capture proxy, we instantiate the elements
17063 gcc_assert (DECL_HAS_VALUE_EXPR_P (t));
17064 return RECUR (DECL_VALUE_EXPR (t));
17070 tree r = tsubst_copy (t, args, complain, in_decl);
17071 /* ??? We're doing a subset of finish_id_expression here. */
17073 && !processing_template_decl
17074 && !cp_unevaluated_operand
17075 && (TREE_STATIC (r) || DECL_EXTERNAL (r))
17076 && CP_DECL_THREAD_LOCAL_P (r))
17078 if (tree wrap = get_tls_wrapper_fn (r))
17079 /* Replace an evaluated use of the thread_local variable with
17080 a call to its wrapper. */
17081 r = build_cxx_call (wrap, 0, NULL, tf_warning_or_error);
17083 else if (outer_automatic_var_p (r))
17085 r = process_outer_var_ref (r, complain);
17086 if (is_capture_proxy (r))
17087 register_local_specialization (r, t);
17090 if (TREE_CODE (TREE_TYPE (t)) != REFERENCE_TYPE)
17091 /* If the original type was a reference, we'll be wrapped in
17092 the appropriate INDIRECT_REF. */
17093 r = convert_from_reference (r);
17099 tree op0 = RECUR (TREE_OPERAND (t, 0));
17100 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
17101 RETURN (build_x_va_arg (EXPR_LOCATION (t), op0, type));
17104 case OFFSETOF_EXPR:
17105 RETURN (finish_offsetof (RECUR (TREE_OPERAND (t, 0)),
17106 EXPR_LOCATION (t)));
17110 tree type1 = tsubst (TRAIT_EXPR_TYPE1 (t), args,
17111 complain, in_decl);
17113 tree type2 = TRAIT_EXPR_TYPE2 (t);
17114 if (type2 && TREE_CODE (type2) == TREE_LIST)
17115 type2 = RECUR (type2);
17117 type2 = tsubst (type2, args, complain, in_decl);
17119 RETURN (finish_trait_expr (TRAIT_EXPR_KIND (t), type1, type2));
17124 tree old_stmt_expr = cur_stmt_expr;
17125 tree stmt_expr = begin_stmt_expr ();
17127 cur_stmt_expr = stmt_expr;
17128 tsubst_expr (STMT_EXPR_STMT (t), args, complain, in_decl,
17129 integral_constant_expression_p);
17130 stmt_expr = finish_stmt_expr (stmt_expr, false);
17131 cur_stmt_expr = old_stmt_expr;
17133 /* If the resulting list of expression statement is empty,
17134 fold it further into void_node. */
17135 if (empty_expr_stmt_p (stmt_expr))
17136 stmt_expr = void_node;
17138 RETURN (stmt_expr);
17143 tree r = build_lambda_expr ();
17145 tree type = tsubst (LAMBDA_EXPR_CLOSURE (t), args, complain, NULL_TREE);
17146 LAMBDA_EXPR_CLOSURE (r) = type;
17147 CLASSTYPE_LAMBDA_EXPR (type) = r;
17149 LAMBDA_EXPR_LOCATION (r)
17150 = LAMBDA_EXPR_LOCATION (t);
17151 LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (r)
17152 = LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (t);
17153 LAMBDA_EXPR_MUTABLE_P (r) = LAMBDA_EXPR_MUTABLE_P (t);
17154 LAMBDA_EXPR_DISCRIMINATOR (r)
17155 = (LAMBDA_EXPR_DISCRIMINATOR (t));
17156 tree scope = LAMBDA_EXPR_EXTRA_SCOPE (t);
17158 /* No substitution needed. */;
17159 else if (VAR_OR_FUNCTION_DECL_P (scope))
17160 /* For a function or variable scope, we want to use tsubst so that we
17161 don't complain about referring to an auto before deduction. */
17162 scope = tsubst (scope, args, complain, in_decl);
17163 else if (TREE_CODE (scope) == PARM_DECL)
17165 /* Look up the parameter we want directly, as tsubst_copy
17166 doesn't do what we need. */
17167 tree fn = tsubst (DECL_CONTEXT (scope), args, complain, in_decl);
17168 tree parm = FUNCTION_FIRST_USER_PARM (fn);
17169 while (DECL_PARM_INDEX (parm) != DECL_PARM_INDEX (scope))
17170 parm = DECL_CHAIN (parm);
17172 /* FIXME Work around the parm not having DECL_CONTEXT set. */
17173 if (DECL_CONTEXT (scope) == NULL_TREE)
17174 DECL_CONTEXT (scope) = fn;
17176 else if (TREE_CODE (scope) == FIELD_DECL)
17177 /* For a field, use tsubst_copy so that we look up the existing field
17178 rather than build a new one. */
17179 scope = RECUR (scope);
17181 gcc_unreachable ();
17182 LAMBDA_EXPR_EXTRA_SCOPE (r) = scope;
17184 gcc_assert (LAMBDA_EXPR_THIS_CAPTURE (t) == NULL_TREE
17185 && LAMBDA_EXPR_PENDING_PROXIES (t) == NULL);
17187 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
17188 determine_visibility (TYPE_NAME (type));
17189 /* Now that we know visibility, instantiate the type so we have a
17190 declaration of the op() for later calls to lambda_function. */
17191 complete_type (type);
17193 if (tree fn = lambda_function (type))
17194 LAMBDA_EXPR_RETURN_TYPE (r) = TREE_TYPE (TREE_TYPE (fn));
17196 LAMBDA_EXPR_THIS_CAPTURE (r) = NULL_TREE;
17198 insert_pending_capture_proxies ();
17200 RETURN (build_lambda_object (r));
17204 /* We can get here for a constant initializer of non-dependent type.
17205 FIXME stop folding in cp_parser_initializer_clause. */
17207 tree r = get_target_expr_sfinae (RECUR (TARGET_EXPR_INITIAL (t)),
17212 case TRANSACTION_EXPR:
17213 RETURN (tsubst_expr(t, args, complain, in_decl,
17214 integral_constant_expression_p));
17217 RETURN (finish_parenthesized_expr (RECUR (TREE_OPERAND (t, 0))));
17219 case VEC_PERM_EXPR:
17221 tree op0 = RECUR (TREE_OPERAND (t, 0));
17222 tree op1 = RECUR (TREE_OPERAND (t, 1));
17223 tree op2 = RECUR (TREE_OPERAND (t, 2));
17224 RETURN (build_x_vec_perm_expr (input_location, op0, op1, op2,
17228 case REQUIRES_EXPR:
17229 RETURN (tsubst_requires_expr (t, args, complain, in_decl));
17232 /* Handle Objective-C++ constructs, if appropriate. */
17235 = objcp_tsubst_copy_and_build (t, args, complain,
17236 in_decl, /*function_p=*/false);
17240 RETURN (tsubst_copy (t, args, complain, in_decl));
17246 input_location = loc;
17250 /* Verify that the instantiated ARGS are valid. For type arguments,
17251 make sure that the type's linkage is ok. For non-type arguments,
17252 make sure they are constants if they are integral or enumerations.
17253 Emit an error under control of COMPLAIN, and return TRUE on error. */
17256 check_instantiated_arg (tree tmpl, tree t, tsubst_flags_t complain)
17258 if (dependent_template_arg_p (t))
17260 if (ARGUMENT_PACK_P (t))
17262 tree vec = ARGUMENT_PACK_ARGS (t);
17263 int len = TREE_VEC_LENGTH (vec);
17264 bool result = false;
17267 for (i = 0; i < len; ++i)
17268 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (vec, i), complain))
17272 else if (TYPE_P (t))
17274 /* [basic.link]: A name with no linkage (notably, the name
17275 of a class or enumeration declared in a local scope)
17276 shall not be used to declare an entity with linkage.
17277 This implies that names with no linkage cannot be used as
17280 DR 757 relaxes this restriction for C++0x. */
17281 tree nt = (cxx_dialect > cxx98 ? NULL_TREE
17282 : no_linkage_check (t, /*relaxed_p=*/false));
17286 /* DR 488 makes use of a type with no linkage cause
17287 type deduction to fail. */
17288 if (complain & tf_error)
17290 if (TYPE_ANONYMOUS_P (nt))
17291 error ("%qT is/uses anonymous type", t);
17293 error ("template argument for %qD uses local type %qT",
17298 /* In order to avoid all sorts of complications, we do not
17299 allow variably-modified types as template arguments. */
17300 else if (variably_modified_type_p (t, NULL_TREE))
17302 if (complain & tf_error)
17303 error ("%qT is a variably modified type", t);
17307 /* Class template and alias template arguments should be OK. */
17308 else if (DECL_TYPE_TEMPLATE_P (t))
17310 /* A non-type argument of integral or enumerated type must be a
17312 else if (TREE_TYPE (t)
17313 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t))
17314 && !REFERENCE_REF_P (t)
17315 && !TREE_CONSTANT (t))
17317 if (complain & tf_error)
17318 error ("integral expression %qE is not constant", t);
17325 check_instantiated_args (tree tmpl, tree args, tsubst_flags_t complain)
17327 int ix, len = DECL_NTPARMS (tmpl);
17328 bool result = false;
17330 for (ix = 0; ix != len; ix++)
17332 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (args, ix), complain))
17335 if (result && (complain & tf_error))
17336 error (" trying to instantiate %qD", tmpl);
17340 /* We're out of SFINAE context now, so generate diagnostics for the access
17341 errors we saw earlier when instantiating D from TMPL and ARGS. */
17344 recheck_decl_substitution (tree d, tree tmpl, tree args)
17346 tree pattern = DECL_TEMPLATE_RESULT (tmpl);
17347 tree type = TREE_TYPE (pattern);
17348 location_t loc = input_location;
17350 push_access_scope (d);
17351 push_deferring_access_checks (dk_no_deferred);
17352 input_location = DECL_SOURCE_LOCATION (pattern);
17353 tsubst (type, args, tf_warning_or_error, d);
17354 input_location = loc;
17355 pop_deferring_access_checks ();
17356 pop_access_scope (d);
17359 /* Instantiate the indicated variable, function, or alias template TMPL with
17360 the template arguments in TARG_PTR. */
17363 instantiate_template_1 (tree tmpl, tree orig_args, tsubst_flags_t complain)
17365 tree targ_ptr = orig_args;
17369 bool access_ok = true;
17371 if (tmpl == error_mark_node)
17372 return error_mark_node;
17374 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
17376 /* If this function is a clone, handle it specially. */
17377 if (DECL_CLONED_FUNCTION_P (tmpl))
17382 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
17383 DECL_CLONED_FUNCTION. */
17384 spec = instantiate_template (DECL_ABSTRACT_ORIGIN (tmpl),
17385 targ_ptr, complain);
17386 if (spec == error_mark_node)
17387 return error_mark_node;
17389 /* Look for the clone. */
17390 FOR_EACH_CLONE (clone, spec)
17391 if (DECL_NAME (clone) == DECL_NAME (tmpl))
17393 /* We should always have found the clone by now. */
17394 gcc_unreachable ();
17398 if (targ_ptr == error_mark_node)
17399 return error_mark_node;
17401 /* Check to see if we already have this specialization. */
17402 gen_tmpl = most_general_template (tmpl);
17403 if (tmpl != gen_tmpl)
17404 /* The TMPL is a partial instantiation. To get a full set of
17405 arguments we must add the arguments used to perform the
17406 partial instantiation. */
17407 targ_ptr = add_outermost_template_args (DECL_TI_ARGS (tmpl),
17410 /* It would be nice to avoid hashing here and then again in tsubst_decl,
17411 but it doesn't seem to be on the hot path. */
17412 spec = retrieve_specialization (gen_tmpl, targ_ptr, 0);
17414 gcc_assert (tmpl == gen_tmpl
17415 || ((fndecl = retrieve_specialization (tmpl, orig_args, 0))
17417 || fndecl == NULL_TREE);
17419 if (spec != NULL_TREE)
17421 if (FNDECL_HAS_ACCESS_ERRORS (spec))
17423 if (complain & tf_error)
17424 recheck_decl_substitution (spec, gen_tmpl, targ_ptr);
17425 return error_mark_node;
17430 if (check_instantiated_args (gen_tmpl, INNERMOST_TEMPLATE_ARGS (targ_ptr),
17432 return error_mark_node;
17434 /* We are building a FUNCTION_DECL, during which the access of its
17435 parameters and return types have to be checked. However this
17436 FUNCTION_DECL which is the desired context for access checking
17437 is not built yet. We solve this chicken-and-egg problem by
17438 deferring all checks until we have the FUNCTION_DECL. */
17439 push_deferring_access_checks (dk_deferred);
17441 /* Instantiation of the function happens in the context of the function
17442 template, not the context of the overload resolution we're doing. */
17443 push_to_top_level ();
17444 /* If there are dependent arguments, e.g. because we're doing partial
17445 ordering, make sure processing_template_decl stays set. */
17446 if (uses_template_parms (targ_ptr))
17447 ++processing_template_decl;
17448 if (DECL_CLASS_SCOPE_P (gen_tmpl))
17450 tree ctx = tsubst_aggr_type (DECL_CONTEXT (gen_tmpl), targ_ptr,
17451 complain, gen_tmpl, true);
17452 push_nested_class (ctx);
17455 tree pattern = DECL_TEMPLATE_RESULT (gen_tmpl);
17457 fndecl = NULL_TREE;
17458 if (VAR_P (pattern))
17460 /* We need to determine if we're using a partial or explicit
17461 specialization now, because the type of the variable could be
17463 tree tid = lookup_template_variable (gen_tmpl, targ_ptr);
17464 tree elt = most_specialized_partial_spec (tid, complain);
17465 if (elt == error_mark_node)
17466 pattern = error_mark_node;
17469 tree partial_tmpl = TREE_VALUE (elt);
17470 tree partial_args = TREE_PURPOSE (elt);
17471 tree partial_pat = DECL_TEMPLATE_RESULT (partial_tmpl);
17472 fndecl = tsubst (partial_pat, partial_args, complain, gen_tmpl);
17476 /* Substitute template parameters to obtain the specialization. */
17477 if (fndecl == NULL_TREE)
17478 fndecl = tsubst (pattern, targ_ptr, complain, gen_tmpl);
17479 if (DECL_CLASS_SCOPE_P (gen_tmpl))
17480 pop_nested_class ();
17481 pop_from_top_level ();
17483 if (fndecl == error_mark_node)
17485 pop_deferring_access_checks ();
17486 return error_mark_node;
17489 /* The DECL_TI_TEMPLATE should always be the immediate parent
17490 template, not the most general template. */
17491 DECL_TI_TEMPLATE (fndecl) = tmpl;
17492 DECL_TI_ARGS (fndecl) = targ_ptr;
17494 /* Now we know the specialization, compute access previously
17496 push_access_scope (fndecl);
17497 if (!perform_deferred_access_checks (complain))
17499 pop_access_scope (fndecl);
17500 pop_deferring_access_checks ();
17502 /* If we've just instantiated the main entry point for a function,
17503 instantiate all the alternate entry points as well. We do this
17504 by cloning the instantiation of the main entry point, not by
17505 instantiating the template clones. */
17506 if (DECL_CHAIN (gen_tmpl) && DECL_CLONED_FUNCTION_P (DECL_CHAIN (gen_tmpl)))
17507 clone_function_decl (fndecl, /*update_method_vec_p=*/0);
17511 if (!(complain & tf_error))
17513 /* Remember to reinstantiate when we're out of SFINAE so the user
17514 can see the errors. */
17515 FNDECL_HAS_ACCESS_ERRORS (fndecl) = true;
17517 return error_mark_node;
17522 /* Wrapper for instantiate_template_1. */
17525 instantiate_template (tree tmpl, tree orig_args, tsubst_flags_t complain)
17528 timevar_push (TV_TEMPLATE_INST);
17529 ret = instantiate_template_1 (tmpl, orig_args, complain);
17530 timevar_pop (TV_TEMPLATE_INST);
17534 /* Instantiate the alias template TMPL with ARGS. Also push a template
17535 instantiation level, which instantiate_template doesn't do because
17536 functions and variables have sufficient context established by the
17540 instantiate_alias_template (tree tmpl, tree args, tsubst_flags_t complain)
17542 struct pending_template *old_last_pend = last_pending_template;
17543 struct tinst_level *old_error_tinst = last_error_tinst_level;
17544 if (tmpl == error_mark_node || args == error_mark_node)
17545 return error_mark_node;
17546 tree tinst = build_tree_list (tmpl, args);
17547 if (!push_tinst_level (tinst))
17550 return error_mark_node;
17554 coerce_innermost_template_parms (DECL_TEMPLATE_PARMS (tmpl),
17555 args, tmpl, complain,
17556 /*require_all_args=*/true,
17557 /*use_default_args=*/true);
17559 tree r = instantiate_template (tmpl, args, complain);
17560 pop_tinst_level ();
17561 /* We can't free this if a pending_template entry or last_error_tinst_level
17562 is pointing at it. */
17563 if (last_pending_template == old_last_pend
17564 && last_error_tinst_level == old_error_tinst)
17570 /* PARM is a template parameter pack for FN. Returns true iff
17571 PARM is used in a deducible way in the argument list of FN. */
17574 pack_deducible_p (tree parm, tree fn)
17576 tree t = FUNCTION_FIRST_USER_PARMTYPE (fn);
17577 for (; t; t = TREE_CHAIN (t))
17579 tree type = TREE_VALUE (t);
17581 if (!PACK_EXPANSION_P (type))
17583 for (packs = PACK_EXPANSION_PARAMETER_PACKS (type);
17584 packs; packs = TREE_CHAIN (packs))
17585 if (template_args_equal (TREE_VALUE (packs), parm))
17587 /* The template parameter pack is used in a function parameter
17588 pack. If this is the end of the parameter list, the
17589 template parameter pack is deducible. */
17590 if (TREE_CHAIN (t) == void_list_node)
17593 /* Otherwise, not. Well, it could be deduced from
17594 a non-pack parameter, but doing so would end up with
17595 a deduction mismatch, so don't bother. */
17599 /* The template parameter pack isn't used in any function parameter
17600 packs, but it might be used deeper, e.g. tuple<Args...>. */
17604 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
17605 NARGS elements of the arguments that are being used when calling
17606 it. TARGS is a vector into which the deduced template arguments
17609 Returns either a FUNCTION_DECL for the matching specialization of FN or
17610 NULL_TREE if no suitable specialization can be found. If EXPLAIN_P is
17611 true, diagnostics will be printed to explain why it failed.
17613 If FN is a conversion operator, or we are trying to produce a specific
17614 specialization, RETURN_TYPE is the return type desired.
17616 The EXPLICIT_TARGS are explicit template arguments provided via a
17619 The parameter STRICT is one of:
17622 We are deducing arguments for a function call, as in
17623 [temp.deduct.call]. If RETURN_TYPE is non-null, we are
17624 deducing arguments for a call to the result of a conversion
17625 function template, as in [over.call.object].
17628 We are deducing arguments for a conversion function, as in
17629 [temp.deduct.conv].
17632 We are deducing arguments when doing an explicit instantiation
17633 as in [temp.explicit], when determining an explicit specialization
17634 as in [temp.expl.spec], or when taking the address of a function
17635 template, as in [temp.deduct.funcaddr]. */
17638 fn_type_unification (tree fn,
17639 tree explicit_targs,
17642 unsigned int nargs,
17644 unification_kind_t strict,
17651 tree decl = NULL_TREE;
17652 tsubst_flags_t complain = (explain_p ? tf_warning_or_error : tf_none);
17654 static int deduction_depth;
17655 struct pending_template *old_last_pend = last_pending_template;
17656 struct tinst_level *old_error_tinst = last_error_tinst_level;
17657 tree tparms = DECL_INNERMOST_TEMPLATE_PARMS (fn);
17659 tree r = error_mark_node;
17662 complain |= tf_decltype;
17664 /* In C++0x, it's possible to have a function template whose type depends
17665 on itself recursively. This is most obvious with decltype, but can also
17666 occur with enumeration scope (c++/48969). So we need to catch infinite
17667 recursion and reject the substitution at deduction time; this function
17668 will return error_mark_node for any repeated substitution.
17670 This also catches excessive recursion such as when f<N> depends on
17671 f<N-1> across all integers, and returns error_mark_node for all the
17672 substitutions back up to the initial one.
17674 This is, of course, not reentrant. */
17675 if (excessive_deduction_depth)
17676 return error_mark_node;
17677 tinst = build_tree_list (fn, NULL_TREE);
17680 gcc_assert (TREE_CODE (fn) == TEMPLATE_DECL);
17682 fntype = TREE_TYPE (fn);
17683 if (explicit_targs)
17687 The specified template arguments must match the template
17688 parameters in kind (i.e., type, nontype, template), and there
17689 must not be more arguments than there are parameters;
17690 otherwise type deduction fails.
17692 Nontype arguments must match the types of the corresponding
17693 nontype template parameters, or must be convertible to the
17694 types of the corresponding nontype parameters as specified in
17695 _temp.arg.nontype_, otherwise type deduction fails.
17697 All references in the function type of the function template
17698 to the corresponding template parameters are replaced by the
17699 specified template argument values. If a substitution in a
17700 template parameter or in the function type of the function
17701 template results in an invalid type, type deduction fails. */
17702 int i, len = TREE_VEC_LENGTH (tparms);
17703 location_t loc = input_location;
17704 bool incomplete = false;
17706 /* Adjust any explicit template arguments before entering the
17707 substitution context. */
17709 = (coerce_template_parms (tparms, explicit_targs, NULL_TREE,
17711 /*require_all_args=*/false,
17712 /*use_default_args=*/false));
17713 if (explicit_targs == error_mark_node)
17716 /* Substitute the explicit args into the function type. This is
17717 necessary so that, for instance, explicitly declared function
17718 arguments can match null pointed constants. If we were given
17719 an incomplete set of explicit args, we must not do semantic
17720 processing during substitution as we could create partial
17722 for (i = 0; i < len; i++)
17724 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
17725 bool parameter_pack = false;
17726 tree targ = TREE_VEC_ELT (explicit_targs, i);
17728 /* Dig out the actual parm. */
17729 if (TREE_CODE (parm) == TYPE_DECL
17730 || TREE_CODE (parm) == TEMPLATE_DECL)
17732 parm = TREE_TYPE (parm);
17733 parameter_pack = TEMPLATE_TYPE_PARAMETER_PACK (parm);
17735 else if (TREE_CODE (parm) == PARM_DECL)
17737 parm = DECL_INITIAL (parm);
17738 parameter_pack = TEMPLATE_PARM_PARAMETER_PACK (parm);
17741 if (!parameter_pack && targ == NULL_TREE)
17742 /* No explicit argument for this template parameter. */
17745 if (parameter_pack && pack_deducible_p (parm, fn))
17747 /* Mark the argument pack as "incomplete". We could
17748 still deduce more arguments during unification.
17749 We remove this mark in type_unification_real. */
17752 ARGUMENT_PACK_INCOMPLETE_P(targ) = 1;
17753 ARGUMENT_PACK_EXPLICIT_ARGS (targ)
17754 = ARGUMENT_PACK_ARGS (targ);
17757 /* We have some incomplete argument packs. */
17762 TREE_VALUE (tinst) = explicit_targs;
17763 if (!push_tinst_level (tinst))
17765 excessive_deduction_depth = true;
17768 processing_template_decl += incomplete;
17769 input_location = DECL_SOURCE_LOCATION (fn);
17770 /* Ignore any access checks; we'll see them again in
17771 instantiate_template and they might have the wrong
17772 access path at this point. */
17773 push_deferring_access_checks (dk_deferred);
17774 fntype = tsubst (TREE_TYPE (fn), explicit_targs,
17775 complain | tf_partial, NULL_TREE);
17776 pop_deferring_access_checks ();
17777 input_location = loc;
17778 processing_template_decl -= incomplete;
17779 pop_tinst_level ();
17781 if (fntype == error_mark_node)
17784 /* Place the explicitly specified arguments in TARGS. */
17785 for (i = NUM_TMPL_ARGS (explicit_targs); i--;)
17786 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (explicit_targs, i);
17789 /* Never do unification on the 'this' parameter. */
17790 parms = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (fntype));
17792 if (return_type && strict == DEDUCE_CALL)
17794 /* We're deducing for a call to the result of a template conversion
17795 function. The parms we really want are in return_type. */
17796 if (POINTER_TYPE_P (return_type))
17797 return_type = TREE_TYPE (return_type);
17798 parms = TYPE_ARG_TYPES (return_type);
17800 else if (return_type)
17804 parms = tree_cons (NULL_TREE, TREE_TYPE (fntype), parms);
17805 new_args = XALLOCAVEC (tree, nargs + 1);
17806 new_args[0] = return_type;
17807 memcpy (new_args + 1, args, nargs * sizeof (tree));
17812 /* We allow incomplete unification without an error message here
17813 because the standard doesn't seem to explicitly prohibit it. Our
17814 callers must be ready to deal with unification failures in any
17817 TREE_VALUE (tinst) = targs;
17818 /* If we aren't explaining yet, push tinst context so we can see where
17819 any errors (e.g. from class instantiations triggered by instantiation
17820 of default template arguments) come from. If we are explaining, this
17821 context is redundant. */
17822 if (!explain_p && !push_tinst_level (tinst))
17824 excessive_deduction_depth = true;
17828 /* type_unification_real will pass back any access checks from default
17829 template argument substitution. */
17830 vec<deferred_access_check, va_gc> *checks;
17833 ok = !type_unification_real (DECL_INNERMOST_TEMPLATE_PARMS (fn),
17834 targs, parms, args, nargs, /*subr=*/0,
17835 strict, flags, &checks, explain_p);
17837 pop_tinst_level ();
17841 /* Now that we have bindings for all of the template arguments,
17842 ensure that the arguments deduced for the template template
17843 parameters have compatible template parameter lists. We cannot
17844 check this property before we have deduced all template
17845 arguments, because the template parameter types of a template
17846 template parameter might depend on prior template parameters
17847 deduced after the template template parameter. The following
17848 ill-formed example illustrates this issue:
17850 template<typename T, template<T> class C> void f(C<5>, T);
17852 template<int N> struct X {};
17855 f(X<5>(), 5l); // error: template argument deduction fails
17858 The template parameter list of 'C' depends on the template type
17859 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
17860 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
17861 time that we deduce 'C'. */
17862 if (!template_template_parm_bindings_ok_p
17863 (DECL_INNERMOST_TEMPLATE_PARMS (fn), targs))
17865 unify_inconsistent_template_template_parameters (explain_p);
17869 /* All is well so far. Now, check:
17873 When all template arguments have been deduced, all uses of
17874 template parameters in nondeduced contexts are replaced with
17875 the corresponding deduced argument values. If the
17876 substitution results in an invalid type, as described above,
17877 type deduction fails. */
17878 TREE_VALUE (tinst) = targs;
17879 if (!push_tinst_level (tinst))
17881 excessive_deduction_depth = true;
17885 /* Also collect access checks from the instantiation. */
17886 reopen_deferring_access_checks (checks);
17888 decl = instantiate_template (fn, targs, complain);
17890 checks = get_deferred_access_checks ();
17891 pop_deferring_access_checks ();
17893 pop_tinst_level ();
17895 if (decl == error_mark_node)
17898 /* Now perform any access checks encountered during substitution. */
17899 push_access_scope (decl);
17900 ok = perform_access_checks (checks, complain);
17901 pop_access_scope (decl);
17905 /* If we're looking for an exact match, check that what we got
17906 is indeed an exact match. It might not be if some template
17907 parameters are used in non-deduced contexts. But don't check
17908 for an exact match if we have dependent template arguments;
17909 in that case we're doing partial ordering, and we already know
17910 that we have two candidates that will provide the actual type. */
17911 if (strict == DEDUCE_EXACT && !any_dependent_template_arguments_p (targs))
17913 tree substed = TREE_TYPE (decl);
17917 = skip_artificial_parms_for (decl, TYPE_ARG_TYPES (substed));
17919 sarg = tree_cons (NULL_TREE, TREE_TYPE (substed), sarg);
17920 for (i = 0; i < nargs && sarg; ++i, sarg = TREE_CHAIN (sarg))
17921 if (!same_type_p (args[i], TREE_VALUE (sarg)))
17923 unify_type_mismatch (explain_p, args[i],
17924 TREE_VALUE (sarg));
17933 if (excessive_deduction_depth)
17935 if (deduction_depth == 0)
17936 /* Reset once we're all the way out. */
17937 excessive_deduction_depth = false;
17940 /* We can't free this if a pending_template entry or last_error_tinst_level
17941 is pointing at it. */
17942 if (last_pending_template == old_last_pend
17943 && last_error_tinst_level == old_error_tinst)
17949 /* Adjust types before performing type deduction, as described in
17950 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
17951 sections are symmetric. PARM is the type of a function parameter
17952 or the return type of the conversion function. ARG is the type of
17953 the argument passed to the call, or the type of the value
17954 initialized with the result of the conversion function.
17955 ARG_EXPR is the original argument expression, which may be null. */
17958 maybe_adjust_types_for_deduction (unification_kind_t strict,
17971 /* Swap PARM and ARG throughout the remainder of this
17972 function; the handling is precisely symmetric since PARM
17973 will initialize ARG rather than vice versa. */
17974 std::swap (parm, arg);
17978 /* Core issue #873: Do the DR606 thing (see below) for these cases,
17979 too, but here handle it by stripping the reference from PARM
17980 rather than by adding it to ARG. */
17981 if (TREE_CODE (*parm) == REFERENCE_TYPE
17982 && TYPE_REF_IS_RVALUE (*parm)
17983 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
17984 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
17985 && TREE_CODE (*arg) == REFERENCE_TYPE
17986 && !TYPE_REF_IS_RVALUE (*arg))
17987 *parm = TREE_TYPE (*parm);
17988 /* Nothing else to do in this case. */
17992 gcc_unreachable ();
17995 if (TREE_CODE (*parm) != REFERENCE_TYPE)
17997 /* [temp.deduct.call]
17999 If P is not a reference type:
18001 --If A is an array type, the pointer type produced by the
18002 array-to-pointer standard conversion (_conv.array_) is
18003 used in place of A for type deduction; otherwise,
18005 --If A is a function type, the pointer type produced by
18006 the function-to-pointer standard conversion
18007 (_conv.func_) is used in place of A for type deduction;
18010 --If A is a cv-qualified type, the top level
18011 cv-qualifiers of A's type are ignored for type
18013 if (TREE_CODE (*arg) == ARRAY_TYPE)
18014 *arg = build_pointer_type (TREE_TYPE (*arg));
18015 else if (TREE_CODE (*arg) == FUNCTION_TYPE)
18016 *arg = build_pointer_type (*arg);
18018 *arg = TYPE_MAIN_VARIANT (*arg);
18021 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
18022 of the form T&&, where T is a template parameter, and the argument
18023 is an lvalue, T is deduced as A& */
18024 if (TREE_CODE (*parm) == REFERENCE_TYPE
18025 && TYPE_REF_IS_RVALUE (*parm)
18026 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
18027 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
18028 && (arg_expr ? real_lvalue_p (arg_expr)
18029 /* try_one_overload doesn't provide an arg_expr, but
18030 functions are always lvalues. */
18031 : TREE_CODE (*arg) == FUNCTION_TYPE))
18032 *arg = build_reference_type (*arg);
18034 /* [temp.deduct.call]
18036 If P is a cv-qualified type, the top level cv-qualifiers
18037 of P's type are ignored for type deduction. If P is a
18038 reference type, the type referred to by P is used for
18040 *parm = TYPE_MAIN_VARIANT (*parm);
18041 if (TREE_CODE (*parm) == REFERENCE_TYPE)
18043 *parm = TREE_TYPE (*parm);
18044 result |= UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
18047 /* DR 322. For conversion deduction, remove a reference type on parm
18048 too (which has been swapped into ARG). */
18049 if (strict == DEDUCE_CONV && TREE_CODE (*arg) == REFERENCE_TYPE)
18050 *arg = TREE_TYPE (*arg);
18055 /* Subroutine of unify_one_argument. PARM is a function parameter of a
18056 template which does contain any deducible template parameters; check if
18057 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
18058 unify_one_argument. */
18061 check_non_deducible_conversion (tree parm, tree arg, int strict,
18062 int flags, bool explain_p)
18067 type = TREE_TYPE (arg);
18071 if (same_type_p (parm, type))
18072 return unify_success (explain_p);
18074 if (strict == DEDUCE_CONV)
18076 if (can_convert_arg (type, parm, NULL_TREE, flags,
18077 explain_p ? tf_warning_or_error : tf_none))
18078 return unify_success (explain_p);
18080 else if (strict != DEDUCE_EXACT)
18082 if (can_convert_arg (parm, type,
18083 TYPE_P (arg) ? NULL_TREE : arg,
18084 flags, explain_p ? tf_warning_or_error : tf_none))
18085 return unify_success (explain_p);
18088 if (strict == DEDUCE_EXACT)
18089 return unify_type_mismatch (explain_p, parm, arg);
18091 return unify_arg_conversion (explain_p, parm, type, arg);
18094 static bool uses_deducible_template_parms (tree type);
18096 /* Returns true iff the expression EXPR is one from which a template
18097 argument can be deduced. In other words, if it's an undecorated
18098 use of a template non-type parameter. */
18101 deducible_expression (tree expr)
18103 return (TREE_CODE (expr) == TEMPLATE_PARM_INDEX);
18106 /* Returns true iff the array domain DOMAIN uses a template parameter in a
18107 deducible way; that is, if it has a max value of <PARM> - 1. */
18110 deducible_array_bound (tree domain)
18112 if (domain == NULL_TREE)
18115 tree max = TYPE_MAX_VALUE (domain);
18116 if (TREE_CODE (max) != MINUS_EXPR)
18119 return deducible_expression (TREE_OPERAND (max, 0));
18122 /* Returns true iff the template arguments ARGS use a template parameter
18123 in a deducible way. */
18126 deducible_template_args (tree args)
18128 for (int i = 0; i < TREE_VEC_LENGTH (args); ++i)
18131 tree elt = TREE_VEC_ELT (args, i);
18132 if (ARGUMENT_PACK_P (elt))
18133 deducible = deducible_template_args (ARGUMENT_PACK_ARGS (elt));
18136 if (PACK_EXPANSION_P (elt))
18137 elt = PACK_EXPANSION_PATTERN (elt);
18138 if (TREE_CODE (elt) == TEMPLATE_TEMPLATE_PARM)
18140 else if (TYPE_P (elt))
18141 deducible = uses_deducible_template_parms (elt);
18143 deducible = deducible_expression (elt);
18151 /* Returns true iff TYPE contains any deducible references to template
18152 parameters, as per 14.8.2.5. */
18155 uses_deducible_template_parms (tree type)
18157 if (PACK_EXPANSION_P (type))
18158 type = PACK_EXPANSION_PATTERN (type);
18165 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
18166 || TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
18172 if (POINTER_TYPE_P (type))
18173 return uses_deducible_template_parms (TREE_TYPE (type));
18175 /* T[integer-constant ]
18177 if (TREE_CODE (type) == ARRAY_TYPE)
18178 return (uses_deducible_template_parms (TREE_TYPE (type))
18179 || deducible_array_bound (TYPE_DOMAIN (type)));
18191 if (TYPE_PTRMEM_P (type))
18192 return (uses_deducible_template_parms (TYPE_PTRMEM_CLASS_TYPE (type))
18193 || (uses_deducible_template_parms
18194 (TYPE_PTRMEM_POINTED_TO_TYPE (type))));
18196 /* template-name <T> (where template-name refers to a class template)
18197 template-name <i> (where template-name refers to a class template) */
18198 if (CLASS_TYPE_P (type)
18199 && CLASSTYPE_TEMPLATE_INFO (type)
18200 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (type)))
18201 return deducible_template_args (INNERMOST_TEMPLATE_ARGS
18202 (CLASSTYPE_TI_ARGS (type)));
18207 if (TREE_CODE (type) == FUNCTION_TYPE
18208 || TREE_CODE (type) == METHOD_TYPE)
18210 if (uses_deducible_template_parms (TREE_TYPE (type)))
18212 tree parm = TYPE_ARG_TYPES (type);
18213 if (TREE_CODE (type) == METHOD_TYPE)
18214 parm = TREE_CHAIN (parm);
18215 for (; parm; parm = TREE_CHAIN (parm))
18216 if (uses_deducible_template_parms (TREE_VALUE (parm)))
18223 /* Subroutine of type_unification_real and unify_pack_expansion to
18224 handle unification of a single P/A pair. Parameters are as
18225 for those functions. */
18228 unify_one_argument (tree tparms, tree targs, tree parm, tree arg,
18229 int subr, unification_kind_t strict,
18232 tree arg_expr = NULL_TREE;
18235 if (arg == error_mark_node || parm == error_mark_node)
18236 return unify_invalid (explain_p);
18237 if (arg == unknown_type_node)
18238 /* We can't deduce anything from this, but we might get all the
18239 template args from other function args. */
18240 return unify_success (explain_p);
18242 /* Implicit conversions (Clause 4) will be performed on a function
18243 argument to convert it to the type of the corresponding function
18244 parameter if the parameter type contains no template-parameters that
18245 participate in template argument deduction. */
18246 if (strict != DEDUCE_EXACT
18247 && TYPE_P (parm) && !uses_deducible_template_parms (parm))
18248 /* For function parameters with no deducible template parameters,
18249 just return. We'll check non-dependent conversions later. */
18250 return unify_success (explain_p);
18255 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
18256 | UNIFY_ALLOW_MORE_CV_QUAL
18257 | UNIFY_ALLOW_DERIVED);
18261 arg_strict = UNIFY_ALLOW_LESS_CV_QUAL;
18265 arg_strict = UNIFY_ALLOW_NONE;
18269 gcc_unreachable ();
18272 /* We only do these transformations if this is the top-level
18273 parameter_type_list in a call or declaration matching; in other
18274 situations (nested function declarators, template argument lists) we
18275 won't be comparing a type to an expression, and we don't do any type
18281 gcc_assert (TREE_TYPE (arg) != NULL_TREE);
18282 if (type_unknown_p (arg))
18284 /* [temp.deduct.type] A template-argument can be
18285 deduced from a pointer to function or pointer
18286 to member function argument if the set of
18287 overloaded functions does not contain function
18288 templates and at most one of a set of
18289 overloaded functions provides a unique
18292 if (resolve_overloaded_unification
18293 (tparms, targs, parm, arg, strict,
18294 arg_strict, explain_p))
18295 return unify_success (explain_p);
18296 return unify_overload_resolution_failure (explain_p, arg);
18300 arg = unlowered_expr_type (arg);
18301 if (arg == error_mark_node)
18302 return unify_invalid (explain_p);
18306 maybe_adjust_types_for_deduction (strict, &parm, &arg, arg_expr);
18309 if ((TYPE_P (parm) || TREE_CODE (parm) == TEMPLATE_DECL)
18310 != (TYPE_P (arg) || TREE_CODE (arg) == TEMPLATE_DECL))
18311 return unify_template_argument_mismatch (explain_p, parm, arg);
18313 /* For deduction from an init-list we need the actual list. */
18314 if (arg_expr && BRACE_ENCLOSED_INITIALIZER_P (arg_expr))
18316 return unify (tparms, targs, parm, arg, arg_strict, explain_p);
18319 /* Most parms like fn_type_unification.
18321 If SUBR is 1, we're being called recursively (to unify the
18322 arguments of a function or method parameter of a function
18325 CHECKS is a pointer to a vector of access checks encountered while
18326 substituting default template arguments. */
18329 type_unification_real (tree tparms,
18333 unsigned int xnargs,
18335 unification_kind_t strict,
18337 vec<deferred_access_check, va_gc> **checks,
18342 int ntparms = TREE_VEC_LENGTH (tparms);
18343 int saw_undeduced = 0;
18346 unsigned int nargs;
18349 gcc_assert (TREE_CODE (tparms) == TREE_VEC);
18350 gcc_assert (xparms == NULL_TREE || TREE_CODE (xparms) == TREE_LIST);
18351 gcc_assert (ntparms > 0);
18353 /* Reset the number of non-defaulted template arguments contained
18355 NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs) = NULL_TREE;
18363 while (parms && parms != void_list_node
18366 parm = TREE_VALUE (parms);
18368 if (TREE_CODE (parm) == TYPE_PACK_EXPANSION
18369 && (!TREE_CHAIN (parms) || TREE_CHAIN (parms) == void_list_node))
18370 /* For a function parameter pack that occurs at the end of the
18371 parameter-declaration-list, the type A of each remaining
18372 argument of the call is compared with the type P of the
18373 declarator-id of the function parameter pack. */
18376 parms = TREE_CHAIN (parms);
18378 if (TREE_CODE (parm) == TYPE_PACK_EXPANSION)
18379 /* For a function parameter pack that does not occur at the
18380 end of the parameter-declaration-list, the type of the
18381 parameter pack is a non-deduced context. */
18387 if (unify_one_argument (tparms, targs, parm, arg, subr, strict,
18393 && parms != void_list_node
18394 && TREE_CODE (TREE_VALUE (parms)) == TYPE_PACK_EXPANSION)
18396 /* Unify the remaining arguments with the pack expansion type. */
18398 tree parmvec = make_tree_vec (1);
18400 /* Allocate a TREE_VEC and copy in all of the arguments */
18401 argvec = make_tree_vec (nargs - ia);
18402 for (i = 0; ia < nargs; ++ia, ++i)
18403 TREE_VEC_ELT (argvec, i) = args[ia];
18405 /* Copy the parameter into parmvec. */
18406 TREE_VEC_ELT (parmvec, 0) = TREE_VALUE (parms);
18407 if (unify_pack_expansion (tparms, targs, parmvec, argvec, strict,
18408 /*subr=*/subr, explain_p))
18411 /* Advance to the end of the list of parameters. */
18412 parms = TREE_CHAIN (parms);
18415 /* Fail if we've reached the end of the parm list, and more args
18416 are present, and the parm list isn't variadic. */
18417 if (ia < nargs && parms == void_list_node)
18418 return unify_too_many_arguments (explain_p, nargs, ia);
18419 /* Fail if parms are left and they don't have default values and
18420 they aren't all deduced as empty packs (c++/57397). This is
18421 consistent with sufficient_parms_p. */
18422 if (parms && parms != void_list_node
18423 && TREE_PURPOSE (parms) == NULL_TREE)
18425 unsigned int count = nargs;
18430 type_pack_p = TREE_CODE (TREE_VALUE (p)) == TYPE_PACK_EXPANSION;
18433 p = TREE_CHAIN (p);
18435 while (p && p != void_list_node);
18436 if (count != nargs)
18437 return unify_too_few_arguments (explain_p, ia, count,
18443 tsubst_flags_t complain = (explain_p
18444 ? tf_warning_or_error
18447 for (i = 0; i < ntparms; i++)
18449 tree targ = TREE_VEC_ELT (targs, i);
18450 tree tparm = TREE_VEC_ELT (tparms, i);
18452 /* Clear the "incomplete" flags on all argument packs now so that
18453 substituting them into later default arguments works. */
18454 if (targ && ARGUMENT_PACK_P (targ))
18456 ARGUMENT_PACK_INCOMPLETE_P (targ) = 0;
18457 ARGUMENT_PACK_EXPLICIT_ARGS (targ) = NULL_TREE;
18460 if (targ || tparm == error_mark_node)
18462 tparm = TREE_VALUE (tparm);
18464 /* If this is an undeduced nontype parameter that depends on
18465 a type parameter, try another pass; its type may have been
18466 deduced from a later argument than the one from which
18467 this parameter can be deduced. */
18468 if (TREE_CODE (tparm) == PARM_DECL
18469 && uses_template_parms (TREE_TYPE (tparm))
18470 && saw_undeduced < 2)
18476 /* Core issue #226 (C++0x) [temp.deduct]:
18478 If a template argument has not been deduced, its
18479 default template argument, if any, is used.
18481 When we are in C++98 mode, TREE_PURPOSE will either
18482 be NULL_TREE or ERROR_MARK_NODE, so we do not need
18483 to explicitly check cxx_dialect here. */
18484 if (TREE_PURPOSE (TREE_VEC_ELT (tparms, i)))
18485 /* OK, there is a default argument. Wait until after the
18486 conversion check to do substitution. */
18489 /* If the type parameter is a parameter pack, then it will
18490 be deduced to an empty parameter pack. */
18491 if (template_parameter_pack_p (tparm))
18495 if (TREE_CODE (tparm) == TEMPLATE_PARM_INDEX)
18497 arg = make_node (NONTYPE_ARGUMENT_PACK);
18498 TREE_TYPE (arg) = TREE_TYPE (TEMPLATE_PARM_DECL (tparm));
18499 TREE_CONSTANT (arg) = 1;
18502 arg = cxx_make_type (TYPE_ARGUMENT_PACK);
18504 SET_ARGUMENT_PACK_ARGS (arg, make_tree_vec (0));
18506 TREE_VEC_ELT (targs, i) = arg;
18510 return unify_parameter_deduction_failure (explain_p, tparm);
18513 /* DR 1391: All parameters have args, now check non-dependent parms for
18515 if (saw_undeduced < 2)
18516 for (ia = 0, parms = xparms, args = xargs, nargs = xnargs;
18517 parms && parms != void_list_node && ia < nargs; )
18519 parm = TREE_VALUE (parms);
18521 if (TREE_CODE (parm) == TYPE_PACK_EXPANSION
18522 && (!TREE_CHAIN (parms)
18523 || TREE_CHAIN (parms) == void_list_node))
18524 /* For a function parameter pack that occurs at the end of the
18525 parameter-declaration-list, the type A of each remaining
18526 argument of the call is compared with the type P of the
18527 declarator-id of the function parameter pack. */
18530 parms = TREE_CHAIN (parms);
18532 if (TREE_CODE (parm) == TYPE_PACK_EXPANSION)
18533 /* For a function parameter pack that does not occur at the
18534 end of the parameter-declaration-list, the type of the
18535 parameter pack is a non-deduced context. */
18541 if (uses_template_parms (parm))
18543 if (check_non_deducible_conversion (parm, arg, strict, flags,
18548 /* Now substitute into the default template arguments. */
18549 for (i = 0; i < ntparms; i++)
18551 tree targ = TREE_VEC_ELT (targs, i);
18552 tree tparm = TREE_VEC_ELT (tparms, i);
18554 if (targ || tparm == error_mark_node)
18556 tree parm = TREE_VALUE (tparm);
18558 if (TREE_CODE (parm) == PARM_DECL
18559 && uses_template_parms (TREE_TYPE (parm))
18560 && saw_undeduced < 2)
18563 tree arg = TREE_PURPOSE (tparm);
18564 reopen_deferring_access_checks (*checks);
18565 location_t save_loc = input_location;
18567 input_location = DECL_SOURCE_LOCATION (parm);
18568 arg = tsubst_template_arg (arg, targs, complain, NULL_TREE);
18569 if (!uses_template_parms (arg))
18570 arg = convert_template_argument (parm, arg, targs, complain,
18572 else if (saw_undeduced < 2)
18575 arg = error_mark_node;
18576 input_location = save_loc;
18577 *checks = get_deferred_access_checks ();
18578 pop_deferring_access_checks ();
18579 if (arg == error_mark_node)
18583 TREE_VEC_ELT (targs, i) = arg;
18584 /* The position of the first default template argument,
18585 is also the number of non-defaulted arguments in TARGS.
18587 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs))
18588 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, i);
18592 if (saw_undeduced++ == 1)
18596 if (CHECKING_P && !NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs))
18597 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, TREE_VEC_LENGTH (targs));
18599 return unify_success (explain_p);
18602 /* Subroutine of type_unification_real. Args are like the variables
18603 at the call site. ARG is an overloaded function (or template-id);
18604 we try deducing template args from each of the overloads, and if
18605 only one succeeds, we go with that. Modifies TARGS and returns
18606 true on success. */
18609 resolve_overloaded_unification (tree tparms,
18613 unification_kind_t strict,
18617 tree tempargs = copy_node (targs);
18619 tree goodfn = NULL_TREE;
18622 if (TREE_CODE (arg) == ADDR_EXPR)
18624 arg = TREE_OPERAND (arg, 0);
18630 if (TREE_CODE (arg) == COMPONENT_REF)
18631 /* Handle `&x' where `x' is some static or non-static member
18633 arg = TREE_OPERAND (arg, 1);
18635 if (TREE_CODE (arg) == OFFSET_REF)
18636 arg = TREE_OPERAND (arg, 1);
18638 /* Strip baselink information. */
18639 if (BASELINK_P (arg))
18640 arg = BASELINK_FUNCTIONS (arg);
18642 if (TREE_CODE (arg) == TEMPLATE_ID_EXPR)
18644 /* If we got some explicit template args, we need to plug them into
18645 the affected templates before we try to unify, in case the
18646 explicit args will completely resolve the templates in question. */
18649 tree expl_subargs = TREE_OPERAND (arg, 1);
18650 arg = TREE_OPERAND (arg, 0);
18652 for (; arg; arg = OVL_NEXT (arg))
18654 tree fn = OVL_CURRENT (arg);
18655 tree subargs, elem;
18657 if (TREE_CODE (fn) != TEMPLATE_DECL)
18660 subargs = coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (fn),
18661 expl_subargs, NULL_TREE, tf_none,
18662 /*require_all_args=*/true,
18663 /*use_default_args=*/true);
18664 if (subargs != error_mark_node
18665 && !any_dependent_template_arguments_p (subargs))
18667 elem = TREE_TYPE (instantiate_template (fn, subargs, tf_none));
18668 if (try_one_overload (tparms, targs, tempargs, parm,
18669 elem, strict, sub_strict, addr_p, explain_p)
18670 && (!goodfn || !same_type_p (goodfn, elem)))
18679 /* If no templates (or more than one) are fully resolved by the
18680 explicit arguments, this template-id is a non-deduced context; it
18681 could still be OK if we deduce all template arguments for the
18682 enclosing call through other arguments. */
18686 else if (TREE_CODE (arg) != OVERLOAD
18687 && TREE_CODE (arg) != FUNCTION_DECL)
18688 /* If ARG is, for example, "(0, &f)" then its type will be unknown
18689 -- but the deduction does not succeed because the expression is
18690 not just the function on its own. */
18693 for (; arg; arg = OVL_NEXT (arg))
18694 if (try_one_overload (tparms, targs, tempargs, parm,
18695 TREE_TYPE (OVL_CURRENT (arg)),
18696 strict, sub_strict, addr_p, explain_p)
18697 && (!goodfn || !decls_match (goodfn, OVL_CURRENT (arg))))
18699 goodfn = OVL_CURRENT (arg);
18703 /* [temp.deduct.type] A template-argument can be deduced from a pointer
18704 to function or pointer to member function argument if the set of
18705 overloaded functions does not contain function templates and at most
18706 one of a set of overloaded functions provides a unique match.
18708 So if we found multiple possibilities, we return success but don't
18709 deduce anything. */
18713 int i = TREE_VEC_LENGTH (targs);
18715 if (TREE_VEC_ELT (tempargs, i))
18717 tree old = TREE_VEC_ELT (targs, i);
18718 tree new_ = TREE_VEC_ELT (tempargs, i);
18719 if (new_ && old && ARGUMENT_PACK_P (old)
18720 && ARGUMENT_PACK_EXPLICIT_ARGS (old))
18721 /* Don't forget explicit template arguments in a pack. */
18722 ARGUMENT_PACK_EXPLICIT_ARGS (new_)
18723 = ARGUMENT_PACK_EXPLICIT_ARGS (old);
18724 TREE_VEC_ELT (targs, i) = new_;
18733 /* Core DR 115: In contexts where deduction is done and fails, or in
18734 contexts where deduction is not done, if a template argument list is
18735 specified and it, along with any default template arguments, identifies
18736 a single function template specialization, then the template-id is an
18737 lvalue for the function template specialization. */
18740 resolve_nondeduced_context (tree orig_expr, tsubst_flags_t complain)
18742 tree expr, offset, baselink;
18745 if (!type_unknown_p (orig_expr))
18750 offset = NULL_TREE;
18751 baselink = NULL_TREE;
18753 if (TREE_CODE (expr) == ADDR_EXPR)
18755 expr = TREE_OPERAND (expr, 0);
18758 if (TREE_CODE (expr) == OFFSET_REF)
18761 expr = TREE_OPERAND (expr, 1);
18763 if (BASELINK_P (expr))
18766 expr = BASELINK_FUNCTIONS (expr);
18769 if (TREE_CODE (expr) == TEMPLATE_ID_EXPR)
18772 tree goodfn = NULL_TREE;
18774 /* If we got some explicit template args, we need to plug them into
18775 the affected templates before we try to unify, in case the
18776 explicit args will completely resolve the templates in question. */
18778 tree expl_subargs = TREE_OPERAND (expr, 1);
18779 tree arg = TREE_OPERAND (expr, 0);
18780 tree badfn = NULL_TREE;
18781 tree badargs = NULL_TREE;
18783 for (; arg; arg = OVL_NEXT (arg))
18785 tree fn = OVL_CURRENT (arg);
18786 tree subargs, elem;
18788 if (TREE_CODE (fn) != TEMPLATE_DECL)
18791 subargs = coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (fn),
18792 expl_subargs, NULL_TREE, tf_none,
18793 /*require_all_args=*/true,
18794 /*use_default_args=*/true);
18795 if (subargs != error_mark_node
18796 && !any_dependent_template_arguments_p (subargs))
18798 elem = instantiate_template (fn, subargs, tf_none);
18799 if (elem == error_mark_node)
18804 else if (elem && (!goodfn || !decls_match (goodfn, elem)))
18813 mark_used (goodfn);
18816 expr = build_baselink (BASELINK_BINFO (baselink),
18817 BASELINK_ACCESS_BINFO (baselink),
18818 expr, BASELINK_OPTYPE (baselink));
18822 = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (offset, 0)));
18823 expr = build_offset_ref (base, expr, addr, complain);
18826 expr = cp_build_addr_expr (expr, complain);
18829 else if (good == 0 && badargs && (complain & tf_error))
18830 /* There were no good options and at least one bad one, so let the
18831 user know what the problem is. */
18832 instantiate_template (badfn, badargs, complain);
18837 /* Subroutine of resolve_overloaded_unification; does deduction for a single
18838 overload. Fills TARGS with any deduced arguments, or error_mark_node if
18839 different overloads deduce different arguments for a given parm.
18840 ADDR_P is true if the expression for which deduction is being
18841 performed was of the form "& fn" rather than simply "fn".
18843 Returns 1 on success. */
18846 try_one_overload (tree tparms,
18851 unification_kind_t strict,
18860 if (arg == error_mark_node)
18863 /* [temp.deduct.type] A template-argument can be deduced from a pointer
18864 to function or pointer to member function argument if the set of
18865 overloaded functions does not contain function templates and at most
18866 one of a set of overloaded functions provides a unique match.
18868 So if this is a template, just return success. */
18870 if (uses_template_parms (arg))
18873 if (TREE_CODE (arg) == METHOD_TYPE)
18874 arg = build_ptrmemfunc_type (build_pointer_type (arg));
18876 arg = build_pointer_type (arg);
18878 sub_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg, NULL);
18880 /* We don't copy orig_targs for this because if we have already deduced
18881 some template args from previous args, unify would complain when we
18882 try to deduce a template parameter for the same argument, even though
18883 there isn't really a conflict. */
18884 nargs = TREE_VEC_LENGTH (targs);
18885 tempargs = make_tree_vec (nargs);
18887 if (unify (tparms, tempargs, parm, arg, sub_strict, explain_p))
18890 /* First make sure we didn't deduce anything that conflicts with
18891 explicitly specified args. */
18892 for (i = nargs; i--; )
18894 tree elt = TREE_VEC_ELT (tempargs, i);
18895 tree oldelt = TREE_VEC_ELT (orig_targs, i);
18899 else if (uses_template_parms (elt))
18900 /* Since we're unifying against ourselves, we will fill in
18901 template args used in the function parm list with our own
18902 template parms. Discard them. */
18903 TREE_VEC_ELT (tempargs, i) = NULL_TREE;
18904 else if (oldelt && ARGUMENT_PACK_P (oldelt))
18906 /* Check that the argument at each index of the deduced argument pack
18907 is equivalent to the corresponding explicitly specified argument.
18908 We may have deduced more arguments than were explicitly specified,
18910 gcc_assert (ARGUMENT_PACK_INCOMPLETE_P (oldelt));
18911 gcc_assert (ARGUMENT_PACK_ARGS (oldelt)
18912 == ARGUMENT_PACK_EXPLICIT_ARGS (oldelt));
18914 tree explicit_pack = ARGUMENT_PACK_ARGS (oldelt);
18915 tree deduced_pack = ARGUMENT_PACK_ARGS (elt);
18917 if (TREE_VEC_LENGTH (deduced_pack)
18918 < TREE_VEC_LENGTH (explicit_pack))
18921 for (int j = 0; j < TREE_VEC_LENGTH (explicit_pack); j++)
18922 if (!template_args_equal (TREE_VEC_ELT (explicit_pack, j),
18923 TREE_VEC_ELT (deduced_pack, j)))
18926 else if (oldelt && !template_args_equal (oldelt, elt))
18930 for (i = nargs; i--; )
18932 tree elt = TREE_VEC_ELT (tempargs, i);
18935 TREE_VEC_ELT (targs, i) = elt;
18941 /* PARM is a template class (perhaps with unbound template
18942 parameters). ARG is a fully instantiated type. If ARG can be
18943 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
18944 TARGS are as for unify. */
18947 try_class_unification (tree tparms, tree targs, tree parm, tree arg,
18950 tree copy_of_targs;
18952 if (!CLASSTYPE_TEMPLATE_INFO (arg)
18953 || (most_general_template (CLASSTYPE_TI_TEMPLATE (arg))
18954 != most_general_template (CLASSTYPE_TI_TEMPLATE (parm))))
18957 /* We need to make a new template argument vector for the call to
18958 unify. If we used TARGS, we'd clutter it up with the result of
18959 the attempted unification, even if this class didn't work out.
18960 We also don't want to commit ourselves to all the unifications
18961 we've already done, since unification is supposed to be done on
18962 an argument-by-argument basis. In other words, consider the
18963 following pathological case:
18965 template <int I, int J, int K>
18968 template <int I, int J>
18969 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
18971 template <int I, int J, int K>
18972 void f(S<I, J, K>, S<I, I, I>);
18981 Now, by the time we consider the unification involving `s2', we
18982 already know that we must have `f<0, 0, 0>'. But, even though
18983 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
18984 because there are two ways to unify base classes of S<0, 1, 2>
18985 with S<I, I, I>. If we kept the already deduced knowledge, we
18986 would reject the possibility I=1. */
18987 copy_of_targs = make_tree_vec (TREE_VEC_LENGTH (targs));
18989 /* If unification failed, we're done. */
18990 if (unify (tparms, copy_of_targs, CLASSTYPE_TI_ARGS (parm),
18991 CLASSTYPE_TI_ARGS (arg), UNIFY_ALLOW_NONE, explain_p))
18997 /* Given a template type PARM and a class type ARG, find the unique
18998 base type in ARG that is an instance of PARM. We do not examine
18999 ARG itself; only its base-classes. If there is not exactly one
19000 appropriate base class, return NULL_TREE. PARM may be the type of
19001 a partial specialization, as well as a plain template type. Used
19004 static enum template_base_result
19005 get_template_base (tree tparms, tree targs, tree parm, tree arg,
19006 bool explain_p, tree *result)
19008 tree rval = NULL_TREE;
19011 gcc_assert (RECORD_OR_UNION_CODE_P (TREE_CODE (arg)));
19013 binfo = TYPE_BINFO (complete_type (arg));
19016 /* The type could not be completed. */
19017 *result = NULL_TREE;
19018 return tbr_incomplete_type;
19021 /* Walk in inheritance graph order. The search order is not
19022 important, and this avoids multiple walks of virtual bases. */
19023 for (binfo = TREE_CHAIN (binfo); binfo; binfo = TREE_CHAIN (binfo))
19025 tree r = try_class_unification (tparms, targs, parm,
19026 BINFO_TYPE (binfo), explain_p);
19030 /* If there is more than one satisfactory baseclass, then:
19034 If they yield more than one possible deduced A, the type
19038 if (rval && !same_type_p (r, rval))
19040 *result = NULL_TREE;
19041 return tbr_ambiguous_baseclass;
19049 return tbr_success;
19052 /* Returns the level of DECL, which declares a template parameter. */
19055 template_decl_level (tree decl)
19057 switch (TREE_CODE (decl))
19060 case TEMPLATE_DECL:
19061 return TEMPLATE_TYPE_LEVEL (TREE_TYPE (decl));
19064 return TEMPLATE_PARM_LEVEL (DECL_INITIAL (decl));
19067 gcc_unreachable ();
19072 /* Decide whether ARG can be unified with PARM, considering only the
19073 cv-qualifiers of each type, given STRICT as documented for unify.
19074 Returns nonzero iff the unification is OK on that basis. */
19077 check_cv_quals_for_unify (int strict, tree arg, tree parm)
19079 int arg_quals = cp_type_quals (arg);
19080 int parm_quals = cp_type_quals (parm);
19082 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
19083 && !(strict & UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
19085 /* Although a CVR qualifier is ignored when being applied to a
19086 substituted template parameter ([8.3.2]/1 for example), that
19087 does not allow us to unify "const T" with "int&" because both
19088 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
19089 It is ok when we're allowing additional CV qualifiers
19090 at the outer level [14.8.2.1]/3,1st bullet. */
19091 if ((TREE_CODE (arg) == REFERENCE_TYPE
19092 || TREE_CODE (arg) == FUNCTION_TYPE
19093 || TREE_CODE (arg) == METHOD_TYPE)
19094 && (parm_quals & (TYPE_QUAL_CONST | TYPE_QUAL_VOLATILE)))
19097 if ((!POINTER_TYPE_P (arg) && TREE_CODE (arg) != TEMPLATE_TYPE_PARM)
19098 && (parm_quals & TYPE_QUAL_RESTRICT))
19102 if (!(strict & (UNIFY_ALLOW_MORE_CV_QUAL | UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
19103 && (arg_quals & parm_quals) != parm_quals)
19106 if (!(strict & (UNIFY_ALLOW_LESS_CV_QUAL | UNIFY_ALLOW_OUTER_LESS_CV_QUAL))
19107 && (parm_quals & arg_quals) != arg_quals)
19113 /* Determines the LEVEL and INDEX for the template parameter PARM. */
19115 template_parm_level_and_index (tree parm, int* level, int* index)
19117 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
19118 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
19119 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
19121 *index = TEMPLATE_TYPE_IDX (parm);
19122 *level = TEMPLATE_TYPE_LEVEL (parm);
19126 *index = TEMPLATE_PARM_IDX (parm);
19127 *level = TEMPLATE_PARM_LEVEL (parm);
19131 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
19133 if (unify (TP, TA, P, A, S, EP)) \
19137 /* Unifies the remaining arguments in PACKED_ARGS with the pack
19138 expansion at the end of PACKED_PARMS. Returns 0 if the type
19139 deduction succeeds, 1 otherwise. STRICT is the same as in
19140 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
19141 call argument list. We'll need to adjust the arguments to make them
19142 types. SUBR tells us if this is from a recursive call to
19143 type_unification_real, or for comparing two template argument
19147 unify_pack_expansion (tree tparms, tree targs, tree packed_parms,
19148 tree packed_args, unification_kind_t strict,
19149 bool subr, bool explain_p)
19152 = TREE_VEC_ELT (packed_parms, TREE_VEC_LENGTH (packed_parms) - 1);
19153 tree pattern = PACK_EXPANSION_PATTERN (parm);
19154 tree pack, packs = NULL_TREE;
19155 int i, start = TREE_VEC_LENGTH (packed_parms) - 1;
19157 packed_args = expand_template_argument_pack (packed_args);
19159 int len = TREE_VEC_LENGTH (packed_args);
19161 /* Determine the parameter packs we will be deducing from the
19162 pattern, and record their current deductions. */
19163 for (pack = PACK_EXPANSION_PARAMETER_PACKS (parm);
19164 pack; pack = TREE_CHAIN (pack))
19166 tree parm_pack = TREE_VALUE (pack);
19169 /* Determine the index and level of this parameter pack. */
19170 template_parm_level_and_index (parm_pack, &level, &idx);
19172 /* Keep track of the parameter packs and their corresponding
19174 packs = tree_cons (parm_pack, TMPL_ARG (targs, level, idx), packs);
19175 TREE_TYPE (packs) = make_tree_vec (len - start);
19178 /* Loop through all of the arguments that have not yet been
19179 unified and unify each with the pattern. */
19180 for (i = start; i < len; i++)
19183 bool any_explicit = false;
19184 tree arg = TREE_VEC_ELT (packed_args, i);
19186 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
19187 or the element of its argument pack at the current index if
19188 this argument was explicitly specified. */
19189 for (pack = packs; pack; pack = TREE_CHAIN (pack))
19193 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
19196 if (TREE_VALUE (pack)
19197 && (pargs = ARGUMENT_PACK_EXPLICIT_ARGS (TREE_VALUE (pack)))
19198 && (i - start < TREE_VEC_LENGTH (pargs)))
19200 any_explicit = true;
19201 arg = TREE_VEC_ELT (pargs, i - start);
19203 TMPL_ARG (targs, level, idx) = arg;
19206 /* If we had explicit template arguments, substitute them into the
19207 pattern before deduction. */
19210 /* Some arguments might still be unspecified or dependent. */
19212 ++processing_template_decl;
19213 dependent = any_dependent_template_arguments_p (targs);
19215 --processing_template_decl;
19216 parm = tsubst (pattern, targs,
19217 explain_p ? tf_warning_or_error : tf_none,
19220 --processing_template_decl;
19221 if (parm == error_mark_node)
19227 /* Unify the pattern with the current argument. */
19228 if (unify_one_argument (tparms, targs, parm, arg, subr, strict,
19232 /* For each parameter pack, collect the deduced value. */
19233 for (pack = packs; pack; pack = TREE_CHAIN (pack))
19236 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
19238 TREE_VEC_ELT (TREE_TYPE (pack), i - start) =
19239 TMPL_ARG (targs, level, idx);
19243 /* Verify that the results of unification with the parameter packs
19244 produce results consistent with what we've seen before, and make
19245 the deduced argument packs available. */
19246 for (pack = packs; pack; pack = TREE_CHAIN (pack))
19248 tree old_pack = TREE_VALUE (pack);
19249 tree new_args = TREE_TYPE (pack);
19250 int i, len = TREE_VEC_LENGTH (new_args);
19252 bool nondeduced_p = false;
19254 /* By default keep the original deduced argument pack.
19255 If necessary, more specific code is going to update the
19256 resulting deduced argument later down in this function. */
19257 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
19258 TMPL_ARG (targs, level, idx) = old_pack;
19260 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
19261 actually deduce anything. */
19262 for (i = 0; i < len && !nondeduced_p; ++i)
19263 if (TREE_VEC_ELT (new_args, i) == NULL_TREE)
19264 nondeduced_p = true;
19268 if (old_pack && ARGUMENT_PACK_INCOMPLETE_P (old_pack))
19270 /* If we had fewer function args than explicit template args,
19271 just use the explicits. */
19272 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
19273 int explicit_len = TREE_VEC_LENGTH (explicit_args);
19274 if (len < explicit_len)
19275 new_args = explicit_args;
19281 /* Build the deduced *_ARGUMENT_PACK. */
19282 if (TREE_CODE (TREE_PURPOSE (pack)) == TEMPLATE_PARM_INDEX)
19284 result = make_node (NONTYPE_ARGUMENT_PACK);
19285 TREE_TYPE (result) =
19286 TREE_TYPE (TEMPLATE_PARM_DECL (TREE_PURPOSE (pack)));
19287 TREE_CONSTANT (result) = 1;
19290 result = cxx_make_type (TYPE_ARGUMENT_PACK);
19292 SET_ARGUMENT_PACK_ARGS (result, new_args);
19294 /* Note the deduced argument packs for this parameter
19296 TMPL_ARG (targs, level, idx) = result;
19298 else if (ARGUMENT_PACK_INCOMPLETE_P (old_pack)
19299 && (ARGUMENT_PACK_ARGS (old_pack)
19300 == ARGUMENT_PACK_EXPLICIT_ARGS (old_pack)))
19302 /* We only had the explicitly-provided arguments before, but
19303 now we have a complete set of arguments. */
19304 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
19306 SET_ARGUMENT_PACK_ARGS (old_pack, new_args);
19307 ARGUMENT_PACK_INCOMPLETE_P (old_pack) = 1;
19308 ARGUMENT_PACK_EXPLICIT_ARGS (old_pack) = explicit_args;
19312 tree bad_old_arg = NULL_TREE, bad_new_arg = NULL_TREE;
19313 tree old_args = ARGUMENT_PACK_ARGS (old_pack);
19315 if (!comp_template_args (old_args, new_args,
19316 &bad_old_arg, &bad_new_arg))
19317 /* Inconsistent unification of this parameter pack. */
19318 return unify_parameter_pack_inconsistent (explain_p,
19324 return unify_success (explain_p);
19327 /* Handle unification of the domain of an array. PARM_DOM and ARG_DOM are
19328 INTEGER_TYPEs representing the TYPE_DOMAIN of ARRAY_TYPEs. The other
19329 parameters and return value are as for unify. */
19332 unify_array_domain (tree tparms, tree targs,
19333 tree parm_dom, tree arg_dom,
19341 /* Our representation of array types uses "N - 1" as the
19342 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
19343 not an integer constant. We cannot unify arbitrarily
19344 complex expressions, so we eliminate the MINUS_EXPRs
19346 parm_max = TYPE_MAX_VALUE (parm_dom);
19347 parm_cst = TREE_CODE (parm_max) == INTEGER_CST;
19350 gcc_assert (TREE_CODE (parm_max) == MINUS_EXPR);
19351 parm_max = TREE_OPERAND (parm_max, 0);
19353 arg_max = TYPE_MAX_VALUE (arg_dom);
19354 arg_cst = TREE_CODE (arg_max) == INTEGER_CST;
19357 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
19358 trying to unify the type of a variable with the type
19359 of a template parameter. For example:
19361 template <unsigned int N>
19362 void f (char (&) [N]);
19369 Here, the type of the ARG will be "int [g(i)]", and
19370 may be a SAVE_EXPR, etc. */
19371 if (TREE_CODE (arg_max) != MINUS_EXPR)
19372 return unify_vla_arg (explain_p, arg_dom);
19373 arg_max = TREE_OPERAND (arg_max, 0);
19376 /* If only one of the bounds used a MINUS_EXPR, compensate
19377 by adding one to the other bound. */
19378 if (parm_cst && !arg_cst)
19379 parm_max = fold_build2_loc (input_location, PLUS_EXPR,
19383 else if (arg_cst && !parm_cst)
19384 arg_max = fold_build2_loc (input_location, PLUS_EXPR,
19389 return unify (tparms, targs, parm_max, arg_max,
19390 UNIFY_ALLOW_INTEGER, explain_p);
19393 /* Deduce the value of template parameters. TPARMS is the (innermost)
19394 set of template parameters to a template. TARGS is the bindings
19395 for those template parameters, as determined thus far; TARGS may
19396 include template arguments for outer levels of template parameters
19397 as well. PARM is a parameter to a template function, or a
19398 subcomponent of that parameter; ARG is the corresponding argument.
19399 This function attempts to match PARM with ARG in a manner
19400 consistent with the existing assignments in TARGS. If more values
19401 are deduced, then TARGS is updated.
19403 Returns 0 if the type deduction succeeds, 1 otherwise. The
19404 parameter STRICT is a bitwise or of the following flags:
19407 Require an exact match between PARM and ARG.
19408 UNIFY_ALLOW_MORE_CV_QUAL:
19409 Allow the deduced ARG to be more cv-qualified (by qualification
19410 conversion) than ARG.
19411 UNIFY_ALLOW_LESS_CV_QUAL:
19412 Allow the deduced ARG to be less cv-qualified than ARG.
19413 UNIFY_ALLOW_DERIVED:
19414 Allow the deduced ARG to be a template base class of ARG,
19415 or a pointer to a template base class of the type pointed to by
19417 UNIFY_ALLOW_INTEGER:
19418 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
19419 case for more information.
19420 UNIFY_ALLOW_OUTER_LEVEL:
19421 This is the outermost level of a deduction. Used to determine validity
19422 of qualification conversions. A valid qualification conversion must
19423 have const qualified pointers leading up to the inner type which
19424 requires additional CV quals, except at the outer level, where const
19425 is not required [conv.qual]. It would be normal to set this flag in
19426 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
19427 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
19428 This is the outermost level of a deduction, and PARM can be more CV
19429 qualified at this point.
19430 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
19431 This is the outermost level of a deduction, and PARM can be less CV
19432 qualified at this point. */
19435 unify (tree tparms, tree targs, tree parm, tree arg, int strict,
19441 int strict_in = strict;
19443 /* I don't think this will do the right thing with respect to types.
19444 But the only case I've seen it in so far has been array bounds, where
19445 signedness is the only information lost, and I think that will be
19447 while (TREE_CODE (parm) == NOP_EXPR)
19448 parm = TREE_OPERAND (parm, 0);
19450 if (arg == error_mark_node)
19451 return unify_invalid (explain_p);
19452 if (arg == unknown_type_node
19453 || arg == init_list_type_node)
19454 /* We can't deduce anything from this, but we might get all the
19455 template args from other function args. */
19456 return unify_success (explain_p);
19458 /* If PARM uses template parameters, then we can't bail out here,
19459 even if ARG == PARM, since we won't record unifications for the
19460 template parameters. We might need them if we're trying to
19461 figure out which of two things is more specialized. */
19462 if (arg == parm && !uses_template_parms (parm))
19463 return unify_success (explain_p);
19465 /* Handle init lists early, so the rest of the function can assume
19466 we're dealing with a type. */
19467 if (BRACE_ENCLOSED_INITIALIZER_P (arg))
19471 tree orig_parm = parm;
19473 /* Replace T with std::initializer_list<T> for deduction. */
19474 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
19475 && flag_deduce_init_list)
19476 parm = listify (parm);
19478 if (!is_std_init_list (parm)
19479 && TREE_CODE (parm) != ARRAY_TYPE)
19480 /* We can only deduce from an initializer list argument if the
19481 parameter is std::initializer_list or an array; otherwise this
19482 is a non-deduced context. */
19483 return unify_success (explain_p);
19485 if (TREE_CODE (parm) == ARRAY_TYPE)
19486 elttype = TREE_TYPE (parm);
19489 elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (parm), 0);
19490 /* Deduction is defined in terms of a single type, so just punt
19491 on the (bizarre) std::initializer_list<T...>. */
19492 if (PACK_EXPANSION_P (elttype))
19493 return unify_success (explain_p);
19496 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg), i, elt)
19498 int elt_strict = strict;
19500 if (elt == error_mark_node)
19501 return unify_invalid (explain_p);
19503 if (!BRACE_ENCLOSED_INITIALIZER_P (elt))
19505 tree type = TREE_TYPE (elt);
19506 if (type == error_mark_node)
19507 return unify_invalid (explain_p);
19508 /* It should only be possible to get here for a call. */
19509 gcc_assert (elt_strict & UNIFY_ALLOW_OUTER_LEVEL);
19510 elt_strict |= maybe_adjust_types_for_deduction
19511 (DEDUCE_CALL, &elttype, &type, elt);
19515 RECUR_AND_CHECK_FAILURE (tparms, targs, elttype, elt, elt_strict,
19519 if (TREE_CODE (parm) == ARRAY_TYPE
19520 && deducible_array_bound (TYPE_DOMAIN (parm)))
19522 /* Also deduce from the length of the initializer list. */
19523 tree max = size_int (CONSTRUCTOR_NELTS (arg));
19524 tree idx = compute_array_index_type (NULL_TREE, max, tf_none);
19525 if (idx == error_mark_node)
19526 return unify_invalid (explain_p);
19527 return unify_array_domain (tparms, targs, TYPE_DOMAIN (parm),
19531 /* If the std::initializer_list<T> deduction worked, replace the
19532 deduced A with std::initializer_list<A>. */
19533 if (orig_parm != parm)
19535 idx = TEMPLATE_TYPE_IDX (orig_parm);
19536 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
19537 targ = listify (targ);
19538 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = targ;
19540 return unify_success (explain_p);
19543 /* Immediately reject some pairs that won't unify because of
19544 cv-qualification mismatches. */
19545 if (TREE_CODE (arg) == TREE_CODE (parm)
19547 /* It is the elements of the array which hold the cv quals of an array
19548 type, and the elements might be template type parms. We'll check
19549 when we recurse. */
19550 && TREE_CODE (arg) != ARRAY_TYPE
19551 /* We check the cv-qualifiers when unifying with template type
19552 parameters below. We want to allow ARG `const T' to unify with
19553 PARM `T' for example, when computing which of two templates
19554 is more specialized, for example. */
19555 && TREE_CODE (arg) != TEMPLATE_TYPE_PARM
19556 && !check_cv_quals_for_unify (strict_in, arg, parm))
19557 return unify_cv_qual_mismatch (explain_p, parm, arg);
19559 if (!(strict & UNIFY_ALLOW_OUTER_LEVEL)
19560 && TYPE_P (parm) && !CP_TYPE_CONST_P (parm))
19561 strict &= ~UNIFY_ALLOW_MORE_CV_QUAL;
19562 strict &= ~UNIFY_ALLOW_OUTER_LEVEL;
19563 strict &= ~UNIFY_ALLOW_DERIVED;
19564 strict &= ~UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
19565 strict &= ~UNIFY_ALLOW_OUTER_LESS_CV_QUAL;
19567 switch (TREE_CODE (parm))
19569 case TYPENAME_TYPE:
19571 case UNBOUND_CLASS_TEMPLATE:
19572 /* In a type which contains a nested-name-specifier, template
19573 argument values cannot be deduced for template parameters used
19574 within the nested-name-specifier. */
19575 return unify_success (explain_p);
19577 case TEMPLATE_TYPE_PARM:
19578 case TEMPLATE_TEMPLATE_PARM:
19579 case BOUND_TEMPLATE_TEMPLATE_PARM:
19580 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
19581 if (error_operand_p (tparm))
19582 return unify_invalid (explain_p);
19584 if (TEMPLATE_TYPE_LEVEL (parm)
19585 != template_decl_level (tparm))
19586 /* The PARM is not one we're trying to unify. Just check
19587 to see if it matches ARG. */
19589 if (TREE_CODE (arg) == TREE_CODE (parm)
19590 && (is_auto (parm) ? is_auto (arg)
19591 : same_type_p (parm, arg)))
19592 return unify_success (explain_p);
19594 return unify_type_mismatch (explain_p, parm, arg);
19596 idx = TEMPLATE_TYPE_IDX (parm);
19597 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
19598 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, idx));
19599 if (error_operand_p (tparm))
19600 return unify_invalid (explain_p);
19602 /* Check for mixed types and values. */
19603 if ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
19604 && TREE_CODE (tparm) != TYPE_DECL)
19605 || (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
19606 && TREE_CODE (tparm) != TEMPLATE_DECL))
19607 gcc_unreachable ();
19609 if (TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
19611 /* ARG must be constructed from a template class or a template
19612 template parameter. */
19613 if (TREE_CODE (arg) != BOUND_TEMPLATE_TEMPLATE_PARM
19614 && !CLASSTYPE_SPECIALIZATION_OF_PRIMARY_TEMPLATE_P (arg))
19615 return unify_template_deduction_failure (explain_p, parm, arg);
19617 tree parmvec = TYPE_TI_ARGS (parm);
19618 /* An alias template name is never deduced. */
19619 if (TYPE_ALIAS_P (arg))
19620 arg = strip_typedefs (arg);
19621 tree argvec = INNERMOST_TEMPLATE_ARGS (TYPE_TI_ARGS (arg));
19622 tree full_argvec = add_to_template_args (targs, argvec);
19624 = DECL_INNERMOST_TEMPLATE_PARMS
19625 (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (parm));
19627 int parm_variadic_p = 0;
19629 /* The resolution to DR150 makes clear that default
19630 arguments for an N-argument may not be used to bind T
19631 to a template template parameter with fewer than N
19632 parameters. It is not safe to permit the binding of
19633 default arguments as an extension, as that may change
19634 the meaning of a conforming program. Consider:
19636 struct Dense { static const unsigned int dim = 1; };
19638 template <template <typename> class View,
19640 void operator+(float, View<Block> const&);
19642 template <typename Block,
19643 unsigned int Dim = Block::dim>
19644 struct Lvalue_proxy { operator float() const; };
19648 Lvalue_proxy<Dense> p;
19653 Here, if Lvalue_proxy is permitted to bind to View, then
19654 the global operator+ will be used; if they are not, the
19655 Lvalue_proxy will be converted to float. */
19656 if (coerce_template_parms (parm_parms,
19658 TYPE_TI_TEMPLATE (parm),
19660 ? tf_warning_or_error
19662 /*require_all_args=*/true,
19663 /*use_default_args=*/false)
19664 == error_mark_node)
19667 /* Deduce arguments T, i from TT<T> or TT<i>.
19668 We check each element of PARMVEC and ARGVEC individually
19669 rather than the whole TREE_VEC since they can have
19670 different number of elements. */
19672 parmvec = expand_template_argument_pack (parmvec);
19673 argvec = expand_template_argument_pack (argvec);
19675 len = TREE_VEC_LENGTH (parmvec);
19677 /* Check if the parameters end in a pack, making them
19680 && PACK_EXPANSION_P (TREE_VEC_ELT (parmvec, len - 1)))
19681 parm_variadic_p = 1;
19683 for (i = 0; i < len - parm_variadic_p; ++i)
19684 /* If the template argument list of P contains a pack
19685 expansion that is not the last template argument, the
19686 entire template argument list is a non-deduced
19688 if (PACK_EXPANSION_P (TREE_VEC_ELT (parmvec, i)))
19689 return unify_success (explain_p);
19691 if (TREE_VEC_LENGTH (argvec) < len - parm_variadic_p)
19692 return unify_too_few_arguments (explain_p,
19693 TREE_VEC_LENGTH (argvec), len);
19695 for (i = 0; i < len - parm_variadic_p; ++i)
19697 RECUR_AND_CHECK_FAILURE (tparms, targs,
19698 TREE_VEC_ELT (parmvec, i),
19699 TREE_VEC_ELT (argvec, i),
19700 UNIFY_ALLOW_NONE, explain_p);
19703 if (parm_variadic_p
19704 && unify_pack_expansion (tparms, targs,
19707 /*subr=*/true, explain_p))
19710 arg = TYPE_TI_TEMPLATE (arg);
19712 /* Fall through to deduce template name. */
19715 if (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
19716 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
19718 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
19720 /* Simple cases: Value already set, does match or doesn't. */
19721 if (targ != NULL_TREE && template_args_equal (targ, arg))
19722 return unify_success (explain_p);
19724 return unify_inconsistency (explain_p, parm, targ, arg);
19728 /* If PARM is `const T' and ARG is only `int', we don't have
19729 a match unless we are allowing additional qualification.
19730 If ARG is `const int' and PARM is just `T' that's OK;
19731 that binds `const int' to `T'. */
19732 if (!check_cv_quals_for_unify (strict_in | UNIFY_ALLOW_LESS_CV_QUAL,
19734 return unify_cv_qual_mismatch (explain_p, parm, arg);
19736 /* Consider the case where ARG is `const volatile int' and
19737 PARM is `const T'. Then, T should be `volatile int'. */
19738 arg = cp_build_qualified_type_real
19739 (arg, cp_type_quals (arg) & ~cp_type_quals (parm), tf_none);
19740 if (arg == error_mark_node)
19741 return unify_invalid (explain_p);
19743 /* Simple cases: Value already set, does match or doesn't. */
19744 if (targ != NULL_TREE && same_type_p (targ, arg))
19745 return unify_success (explain_p);
19747 return unify_inconsistency (explain_p, parm, targ, arg);
19749 /* Make sure that ARG is not a variable-sized array. (Note
19750 that were talking about variable-sized arrays (like
19751 `int[n]'), rather than arrays of unknown size (like
19752 `int[]').) We'll get very confused by such a type since
19753 the bound of the array is not constant, and therefore
19754 not mangleable. Besides, such types are not allowed in
19755 ISO C++, so we can do as we please here. We do allow
19756 them for 'auto' deduction, since that isn't ABI-exposed. */
19757 if (!is_auto (parm) && variably_modified_type_p (arg, NULL_TREE))
19758 return unify_vla_arg (explain_p, arg);
19760 /* Strip typedefs as in convert_template_argument. */
19761 arg = canonicalize_type_argument (arg, tf_none);
19764 /* If ARG is a parameter pack or an expansion, we cannot unify
19765 against it unless PARM is also a parameter pack. */
19766 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
19767 && !template_parameter_pack_p (parm))
19768 return unify_parameter_pack_mismatch (explain_p, parm, arg);
19770 /* If the argument deduction results is a METHOD_TYPE,
19771 then there is a problem.
19772 METHOD_TYPE doesn't map to any real C++ type the result of
19773 the deduction can not be of that type. */
19774 if (TREE_CODE (arg) == METHOD_TYPE)
19775 return unify_method_type_error (explain_p, arg);
19777 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
19778 return unify_success (explain_p);
19780 case TEMPLATE_PARM_INDEX:
19781 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
19782 if (error_operand_p (tparm))
19783 return unify_invalid (explain_p);
19785 if (TEMPLATE_PARM_LEVEL (parm)
19786 != template_decl_level (tparm))
19788 /* The PARM is not one we're trying to unify. Just check
19789 to see if it matches ARG. */
19790 int result = !(TREE_CODE (arg) == TREE_CODE (parm)
19791 && cp_tree_equal (parm, arg));
19793 unify_expression_unequal (explain_p, parm, arg);
19797 idx = TEMPLATE_PARM_IDX (parm);
19798 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
19802 int x = !cp_tree_equal (targ, arg);
19804 unify_inconsistency (explain_p, parm, targ, arg);
19808 /* [temp.deduct.type] If, in the declaration of a function template
19809 with a non-type template-parameter, the non-type
19810 template-parameter is used in an expression in the function
19811 parameter-list and, if the corresponding template-argument is
19812 deduced, the template-argument type shall match the type of the
19813 template-parameter exactly, except that a template-argument
19814 deduced from an array bound may be of any integral type.
19815 The non-type parameter might use already deduced type parameters. */
19816 tparm = tsubst (TREE_TYPE (parm), targs, 0, NULL_TREE);
19817 if (!TREE_TYPE (arg))
19818 /* Template-parameter dependent expression. Just accept it for now.
19819 It will later be processed in convert_template_argument. */
19821 else if (same_type_p (TREE_TYPE (arg), tparm))
19823 else if ((strict & UNIFY_ALLOW_INTEGER)
19824 && CP_INTEGRAL_TYPE_P (tparm))
19825 /* Convert the ARG to the type of PARM; the deduced non-type
19826 template argument must exactly match the types of the
19827 corresponding parameter. */
19828 arg = fold (build_nop (tparm, arg));
19829 else if (uses_template_parms (tparm))
19830 /* We haven't deduced the type of this parameter yet. Try again
19832 return unify_success (explain_p);
19834 return unify_type_mismatch (explain_p, tparm, TREE_TYPE (arg));
19836 /* If ARG is a parameter pack or an expansion, we cannot unify
19837 against it unless PARM is also a parameter pack. */
19838 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
19839 && !TEMPLATE_PARM_PARAMETER_PACK (parm))
19840 return unify_parameter_pack_mismatch (explain_p, parm, arg);
19843 bool removed_attr = false;
19844 arg = strip_typedefs_expr (arg, &removed_attr);
19846 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
19847 return unify_success (explain_p);
19851 /* A pointer-to-member constant can be unified only with
19852 another constant. */
19853 if (TREE_CODE (arg) != PTRMEM_CST)
19854 return unify_ptrmem_cst_mismatch (explain_p, parm, arg);
19856 /* Just unify the class member. It would be useless (and possibly
19857 wrong, depending on the strict flags) to unify also
19858 PTRMEM_CST_CLASS, because we want to be sure that both parm and
19859 arg refer to the same variable, even if through different
19860 classes. For instance:
19862 struct A { int x; };
19865 Unification of &A::x and &B::x must succeed. */
19866 return unify (tparms, targs, PTRMEM_CST_MEMBER (parm),
19867 PTRMEM_CST_MEMBER (arg), strict, explain_p);
19872 if (!TYPE_PTR_P (arg))
19873 return unify_type_mismatch (explain_p, parm, arg);
19875 /* [temp.deduct.call]
19877 A can be another pointer or pointer to member type that can
19878 be converted to the deduced A via a qualification
19879 conversion (_conv.qual_).
19881 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
19882 This will allow for additional cv-qualification of the
19883 pointed-to types if appropriate. */
19885 if (TREE_CODE (TREE_TYPE (arg)) == RECORD_TYPE)
19886 /* The derived-to-base conversion only persists through one
19887 level of pointers. */
19888 strict |= (strict_in & UNIFY_ALLOW_DERIVED);
19890 return unify (tparms, targs, TREE_TYPE (parm),
19891 TREE_TYPE (arg), strict, explain_p);
19894 case REFERENCE_TYPE:
19895 if (TREE_CODE (arg) != REFERENCE_TYPE)
19896 return unify_type_mismatch (explain_p, parm, arg);
19897 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
19898 strict & UNIFY_ALLOW_MORE_CV_QUAL, explain_p);
19901 if (TREE_CODE (arg) != ARRAY_TYPE)
19902 return unify_type_mismatch (explain_p, parm, arg);
19903 if ((TYPE_DOMAIN (parm) == NULL_TREE)
19904 != (TYPE_DOMAIN (arg) == NULL_TREE))
19905 return unify_type_mismatch (explain_p, parm, arg);
19906 RECUR_AND_CHECK_FAILURE (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
19907 strict & UNIFY_ALLOW_MORE_CV_QUAL, explain_p);
19908 if (TYPE_DOMAIN (parm) != NULL_TREE)
19909 return unify_array_domain (tparms, targs, TYPE_DOMAIN (parm),
19910 TYPE_DOMAIN (arg), explain_p);
19911 return unify_success (explain_p);
19918 case ENUMERAL_TYPE:
19921 if (TREE_CODE (arg) != TREE_CODE (parm))
19922 return unify_type_mismatch (explain_p, parm, arg);
19924 /* We have already checked cv-qualification at the top of the
19926 if (!same_type_ignoring_top_level_qualifiers_p (arg, parm))
19927 return unify_type_mismatch (explain_p, parm, arg);
19929 /* As far as unification is concerned, this wins. Later checks
19930 will invalidate it if necessary. */
19931 return unify_success (explain_p);
19933 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
19934 /* Type INTEGER_CST can come from ordinary constant template args. */
19936 while (TREE_CODE (arg) == NOP_EXPR)
19937 arg = TREE_OPERAND (arg, 0);
19939 if (TREE_CODE (arg) != INTEGER_CST)
19940 return unify_template_argument_mismatch (explain_p, parm, arg);
19941 return (tree_int_cst_equal (parm, arg)
19942 ? unify_success (explain_p)
19943 : unify_template_argument_mismatch (explain_p, parm, arg));
19947 int i, len, argslen;
19948 int parm_variadic_p = 0;
19950 if (TREE_CODE (arg) != TREE_VEC)
19951 return unify_template_argument_mismatch (explain_p, parm, arg);
19953 len = TREE_VEC_LENGTH (parm);
19954 argslen = TREE_VEC_LENGTH (arg);
19956 /* Check for pack expansions in the parameters. */
19957 for (i = 0; i < len; ++i)
19959 if (PACK_EXPANSION_P (TREE_VEC_ELT (parm, i)))
19962 /* We can unify against something with a trailing
19964 parm_variadic_p = 1;
19966 /* [temp.deduct.type]/9: If the template argument list of
19967 P contains a pack expansion that is not the last
19968 template argument, the entire template argument list
19969 is a non-deduced context. */
19970 return unify_success (explain_p);
19974 /* If we don't have enough arguments to satisfy the parameters
19975 (not counting the pack expression at the end), or we have
19976 too many arguments for a parameter list that doesn't end in
19977 a pack expression, we can't unify. */
19978 if (parm_variadic_p
19979 ? argslen < len - parm_variadic_p
19981 return unify_arity (explain_p, TREE_VEC_LENGTH (arg), len);
19983 /* Unify all of the parameters that precede the (optional)
19984 pack expression. */
19985 for (i = 0; i < len - parm_variadic_p; ++i)
19987 RECUR_AND_CHECK_FAILURE (tparms, targs,
19988 TREE_VEC_ELT (parm, i),
19989 TREE_VEC_ELT (arg, i),
19990 UNIFY_ALLOW_NONE, explain_p);
19992 if (parm_variadic_p)
19993 return unify_pack_expansion (tparms, targs, parm, arg,
19995 /*subr=*/true, explain_p);
19996 return unify_success (explain_p);
20001 if (TREE_CODE (arg) != TREE_CODE (parm))
20002 return unify_type_mismatch (explain_p, parm, arg);
20004 if (TYPE_PTRMEMFUNC_P (parm))
20006 if (!TYPE_PTRMEMFUNC_P (arg))
20007 return unify_type_mismatch (explain_p, parm, arg);
20009 return unify (tparms, targs,
20010 TYPE_PTRMEMFUNC_FN_TYPE (parm),
20011 TYPE_PTRMEMFUNC_FN_TYPE (arg),
20012 strict, explain_p);
20014 else if (TYPE_PTRMEMFUNC_P (arg))
20015 return unify_type_mismatch (explain_p, parm, arg);
20017 if (CLASSTYPE_TEMPLATE_INFO (parm))
20019 tree t = NULL_TREE;
20021 if (strict_in & UNIFY_ALLOW_DERIVED)
20023 /* First, we try to unify the PARM and ARG directly. */
20024 t = try_class_unification (tparms, targs,
20025 parm, arg, explain_p);
20029 /* Fallback to the special case allowed in
20030 [temp.deduct.call]:
20032 If P is a class, and P has the form
20033 template-id, then A can be a derived class of
20034 the deduced A. Likewise, if P is a pointer to
20035 a class of the form template-id, A can be a
20036 pointer to a derived class pointed to by the
20038 enum template_base_result r;
20039 r = get_template_base (tparms, targs, parm, arg,
20044 /* Don't give the derived diagnostic if we're
20045 already dealing with the same template. */
20047 = (CLASSTYPE_TEMPLATE_INFO (arg)
20048 && (CLASSTYPE_TI_TEMPLATE (parm)
20049 == CLASSTYPE_TI_TEMPLATE (arg)));
20050 return unify_no_common_base (explain_p && !same_template,
20055 else if (CLASSTYPE_TEMPLATE_INFO (arg)
20056 && (CLASSTYPE_TI_TEMPLATE (parm)
20057 == CLASSTYPE_TI_TEMPLATE (arg)))
20058 /* Perhaps PARM is something like S<U> and ARG is S<int>.
20059 Then, we should unify `int' and `U'. */
20062 /* There's no chance of unification succeeding. */
20063 return unify_type_mismatch (explain_p, parm, arg);
20065 return unify (tparms, targs, CLASSTYPE_TI_ARGS (parm),
20066 CLASSTYPE_TI_ARGS (t), UNIFY_ALLOW_NONE, explain_p);
20068 else if (!same_type_ignoring_top_level_qualifiers_p (parm, arg))
20069 return unify_type_mismatch (explain_p, parm, arg);
20070 return unify_success (explain_p);
20073 case FUNCTION_TYPE:
20075 unsigned int nargs;
20080 if (TREE_CODE (arg) != TREE_CODE (parm))
20081 return unify_type_mismatch (explain_p, parm, arg);
20083 /* CV qualifications for methods can never be deduced, they must
20084 match exactly. We need to check them explicitly here,
20085 because type_unification_real treats them as any other
20086 cv-qualified parameter. */
20087 if (TREE_CODE (parm) == METHOD_TYPE
20088 && (!check_cv_quals_for_unify
20090 class_of_this_parm (arg),
20091 class_of_this_parm (parm))))
20092 return unify_cv_qual_mismatch (explain_p, parm, arg);
20094 RECUR_AND_CHECK_FAILURE (tparms, targs, TREE_TYPE (parm),
20095 TREE_TYPE (arg), UNIFY_ALLOW_NONE, explain_p);
20097 nargs = list_length (TYPE_ARG_TYPES (arg));
20098 args = XALLOCAVEC (tree, nargs);
20099 for (a = TYPE_ARG_TYPES (arg), i = 0;
20100 a != NULL_TREE && a != void_list_node;
20101 a = TREE_CHAIN (a), ++i)
20102 args[i] = TREE_VALUE (a);
20105 return type_unification_real (tparms, targs, TYPE_ARG_TYPES (parm),
20106 args, nargs, 1, DEDUCE_EXACT,
20107 LOOKUP_NORMAL, NULL, explain_p);
20111 /* Unify a pointer to member with a pointer to member function, which
20112 deduces the type of the member as a function type. */
20113 if (TYPE_PTRMEMFUNC_P (arg))
20115 /* Check top-level cv qualifiers */
20116 if (!check_cv_quals_for_unify (UNIFY_ALLOW_NONE, arg, parm))
20117 return unify_cv_qual_mismatch (explain_p, parm, arg);
20119 RECUR_AND_CHECK_FAILURE (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
20120 TYPE_PTRMEMFUNC_OBJECT_TYPE (arg),
20121 UNIFY_ALLOW_NONE, explain_p);
20123 /* Determine the type of the function we are unifying against. */
20124 tree fntype = static_fn_type (arg);
20126 return unify (tparms, targs, TREE_TYPE (parm), fntype, strict, explain_p);
20129 if (TREE_CODE (arg) != OFFSET_TYPE)
20130 return unify_type_mismatch (explain_p, parm, arg);
20131 RECUR_AND_CHECK_FAILURE (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
20132 TYPE_OFFSET_BASETYPE (arg),
20133 UNIFY_ALLOW_NONE, explain_p);
20134 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
20135 strict, explain_p);
20138 if (DECL_TEMPLATE_PARM_P (parm))
20139 return unify (tparms, targs, DECL_INITIAL (parm), arg, strict, explain_p);
20140 if (arg != scalar_constant_value (parm))
20141 return unify_template_argument_mismatch (explain_p, parm, arg);
20142 return unify_success (explain_p);
20145 case TEMPLATE_DECL:
20146 /* Matched cases are handled by the ARG == PARM test above. */
20147 return unify_template_argument_mismatch (explain_p, parm, arg);
20150 /* We might get a variable as a non-type template argument in parm if the
20151 corresponding parameter is type-dependent. Make any necessary
20152 adjustments based on whether arg is a reference. */
20153 if (CONSTANT_CLASS_P (arg))
20154 parm = fold_non_dependent_expr (parm);
20155 else if (REFERENCE_REF_P (arg))
20157 tree sub = TREE_OPERAND (arg, 0);
20159 if (TREE_CODE (sub) == ADDR_EXPR)
20160 arg = TREE_OPERAND (sub, 0);
20162 /* Now use the normal expression code to check whether they match. */
20165 case TYPE_ARGUMENT_PACK:
20166 case NONTYPE_ARGUMENT_PACK:
20167 return unify (tparms, targs, ARGUMENT_PACK_ARGS (parm),
20168 ARGUMENT_PACK_ARGS (arg), strict, explain_p);
20171 case DECLTYPE_TYPE:
20172 case UNDERLYING_TYPE:
20173 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
20174 or UNDERLYING_TYPE nodes. */
20175 return unify_success (explain_p);
20178 /* Unification fails if we hit an error node. */
20179 return unify_invalid (explain_p);
20182 if (REFERENCE_REF_P (parm))
20184 if (REFERENCE_REF_P (arg))
20185 arg = TREE_OPERAND (arg, 0);
20186 return unify (tparms, targs, TREE_OPERAND (parm, 0), arg,
20187 strict, explain_p);
20192 /* An unresolved overload is a nondeduced context. */
20193 if (is_overloaded_fn (parm) || type_unknown_p (parm))
20194 return unify_success (explain_p);
20195 gcc_assert (EXPR_P (parm) || TREE_CODE (parm) == TRAIT_EXPR);
20197 /* We must be looking at an expression. This can happen with
20201 void foo(S<I>, S<I + 2>);
20203 This is a "nondeduced context":
20207 The nondeduced contexts are:
20209 --A type that is a template-id in which one or more of
20210 the template-arguments is an expression that references
20211 a template-parameter.
20213 In these cases, we assume deduction succeeded, but don't
20214 actually infer any unifications. */
20216 if (!uses_template_parms (parm)
20217 && !template_args_equal (parm, arg))
20218 return unify_expression_unequal (explain_p, parm, arg);
20220 return unify_success (explain_p);
20223 #undef RECUR_AND_CHECK_FAILURE
20225 /* Note that DECL can be defined in this translation unit, if
20229 mark_definable (tree decl)
20232 DECL_NOT_REALLY_EXTERN (decl) = 1;
20233 FOR_EACH_CLONE (clone, decl)
20234 DECL_NOT_REALLY_EXTERN (clone) = 1;
20237 /* Called if RESULT is explicitly instantiated, or is a member of an
20238 explicitly instantiated class. */
20241 mark_decl_instantiated (tree result, int extern_p)
20243 SET_DECL_EXPLICIT_INSTANTIATION (result);
20245 /* If this entity has already been written out, it's too late to
20246 make any modifications. */
20247 if (TREE_ASM_WRITTEN (result))
20250 /* For anonymous namespace we don't need to do anything. */
20251 if (decl_anon_ns_mem_p (result))
20253 gcc_assert (!TREE_PUBLIC (result));
20257 if (TREE_CODE (result) != FUNCTION_DECL)
20258 /* The TREE_PUBLIC flag for function declarations will have been
20259 set correctly by tsubst. */
20260 TREE_PUBLIC (result) = 1;
20262 /* This might have been set by an earlier implicit instantiation. */
20263 DECL_COMDAT (result) = 0;
20266 DECL_NOT_REALLY_EXTERN (result) = 0;
20269 mark_definable (result);
20270 mark_needed (result);
20271 /* Always make artificials weak. */
20272 if (DECL_ARTIFICIAL (result) && flag_weak)
20273 comdat_linkage (result);
20274 /* For WIN32 we also want to put explicit instantiations in
20275 linkonce sections. */
20276 else if (TREE_PUBLIC (result))
20277 maybe_make_one_only (result);
20280 /* If EXTERN_P, then this function will not be emitted -- unless
20281 followed by an explicit instantiation, at which point its linkage
20282 will be adjusted. If !EXTERN_P, then this function will be
20283 emitted here. In neither circumstance do we want
20284 import_export_decl to adjust the linkage. */
20285 DECL_INTERFACE_KNOWN (result) = 1;
20288 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
20289 important template arguments. If any are missing, we check whether
20290 they're important by using error_mark_node for substituting into any
20291 args that were used for partial ordering (the ones between ARGS and END)
20292 and seeing if it bubbles up. */
20295 check_undeduced_parms (tree targs, tree args, tree end)
20297 bool found = false;
20299 for (i = TREE_VEC_LENGTH (targs) - 1; i >= 0; --i)
20300 if (TREE_VEC_ELT (targs, i) == NULL_TREE)
20303 TREE_VEC_ELT (targs, i) = error_mark_node;
20307 tree substed = tsubst_arg_types (args, targs, end, tf_none, NULL_TREE);
20308 if (substed == error_mark_node)
20314 /* Given two function templates PAT1 and PAT2, return:
20316 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
20317 -1 if PAT2 is more specialized than PAT1.
20318 0 if neither is more specialized.
20320 LEN indicates the number of parameters we should consider
20321 (defaulted parameters should not be considered).
20323 The 1998 std underspecified function template partial ordering, and
20324 DR214 addresses the issue. We take pairs of arguments, one from
20325 each of the templates, and deduce them against each other. One of
20326 the templates will be more specialized if all the *other*
20327 template's arguments deduce against its arguments and at least one
20328 of its arguments *does* *not* deduce against the other template's
20329 corresponding argument. Deduction is done as for class templates.
20330 The arguments used in deduction have reference and top level cv
20331 qualifiers removed. Iff both arguments were originally reference
20332 types *and* deduction succeeds in both directions, an lvalue reference
20333 wins against an rvalue reference and otherwise the template
20334 with the more cv-qualified argument wins for that pairing (if
20335 neither is more cv-qualified, they both are equal). Unlike regular
20336 deduction, after all the arguments have been deduced in this way,
20337 we do *not* verify the deduced template argument values can be
20338 substituted into non-deduced contexts.
20340 The logic can be a bit confusing here, because we look at deduce1 and
20341 targs1 to see if pat2 is at least as specialized, and vice versa; if we
20342 can find template arguments for pat1 to make arg1 look like arg2, that
20343 means that arg2 is at least as specialized as arg1. */
20346 more_specialized_fn (tree pat1, tree pat2, int len)
20348 tree decl1 = DECL_TEMPLATE_RESULT (pat1);
20349 tree decl2 = DECL_TEMPLATE_RESULT (pat2);
20350 tree targs1 = make_tree_vec (DECL_NTPARMS (pat1));
20351 tree targs2 = make_tree_vec (DECL_NTPARMS (pat2));
20352 tree tparms1 = DECL_INNERMOST_TEMPLATE_PARMS (pat1);
20353 tree tparms2 = DECL_INNERMOST_TEMPLATE_PARMS (pat2);
20354 tree args1 = TYPE_ARG_TYPES (TREE_TYPE (decl1));
20355 tree args2 = TYPE_ARG_TYPES (TREE_TYPE (decl2));
20356 tree origs1, origs2;
20357 bool lose1 = false;
20358 bool lose2 = false;
20360 /* Remove the this parameter from non-static member functions. If
20361 one is a non-static member function and the other is not a static
20362 member function, remove the first parameter from that function
20363 also. This situation occurs for operator functions where we
20364 locate both a member function (with this pointer) and non-member
20365 operator (with explicit first operand). */
20366 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl1))
20368 len--; /* LEN is the number of significant arguments for DECL1 */
20369 args1 = TREE_CHAIN (args1);
20370 if (!DECL_STATIC_FUNCTION_P (decl2))
20371 args2 = TREE_CHAIN (args2);
20373 else if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl2))
20375 args2 = TREE_CHAIN (args2);
20376 if (!DECL_STATIC_FUNCTION_P (decl1))
20379 args1 = TREE_CHAIN (args1);
20383 /* If only one is a conversion operator, they are unordered. */
20384 if (DECL_CONV_FN_P (decl1) != DECL_CONV_FN_P (decl2))
20387 /* Consider the return type for a conversion function */
20388 if (DECL_CONV_FN_P (decl1))
20390 args1 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl1)), args1);
20391 args2 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl2)), args2);
20395 processing_template_decl++;
20401 /* Stop when an ellipsis is seen. */
20402 && args1 != NULL_TREE && args2 != NULL_TREE)
20404 tree arg1 = TREE_VALUE (args1);
20405 tree arg2 = TREE_VALUE (args2);
20406 int deduce1, deduce2;
20412 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
20413 && TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
20415 /* When both arguments are pack expansions, we need only
20416 unify the patterns themselves. */
20417 arg1 = PACK_EXPANSION_PATTERN (arg1);
20418 arg2 = PACK_EXPANSION_PATTERN (arg2);
20420 /* This is the last comparison we need to do. */
20424 if (TREE_CODE (arg1) == REFERENCE_TYPE)
20426 ref1 = TYPE_REF_IS_RVALUE (arg1) + 1;
20427 arg1 = TREE_TYPE (arg1);
20428 quals1 = cp_type_quals (arg1);
20431 if (TREE_CODE (arg2) == REFERENCE_TYPE)
20433 ref2 = TYPE_REF_IS_RVALUE (arg2) + 1;
20434 arg2 = TREE_TYPE (arg2);
20435 quals2 = cp_type_quals (arg2);
20438 arg1 = TYPE_MAIN_VARIANT (arg1);
20439 arg2 = TYPE_MAIN_VARIANT (arg2);
20441 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION)
20443 int i, len2 = remaining_arguments (args2);
20444 tree parmvec = make_tree_vec (1);
20445 tree argvec = make_tree_vec (len2);
20448 /* Setup the parameter vector, which contains only ARG1. */
20449 TREE_VEC_ELT (parmvec, 0) = arg1;
20451 /* Setup the argument vector, which contains the remaining
20453 for (i = 0; i < len2; i++, ta = TREE_CHAIN (ta))
20454 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
20456 deduce1 = (unify_pack_expansion (tparms1, targs1, parmvec,
20457 argvec, DEDUCE_EXACT,
20458 /*subr=*/true, /*explain_p=*/false)
20461 /* We cannot deduce in the other direction, because ARG1 is
20462 a pack expansion but ARG2 is not. */
20465 else if (TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
20467 int i, len1 = remaining_arguments (args1);
20468 tree parmvec = make_tree_vec (1);
20469 tree argvec = make_tree_vec (len1);
20472 /* Setup the parameter vector, which contains only ARG1. */
20473 TREE_VEC_ELT (parmvec, 0) = arg2;
20475 /* Setup the argument vector, which contains the remaining
20477 for (i = 0; i < len1; i++, ta = TREE_CHAIN (ta))
20478 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
20480 deduce2 = (unify_pack_expansion (tparms2, targs2, parmvec,
20481 argvec, DEDUCE_EXACT,
20482 /*subr=*/true, /*explain_p=*/false)
20485 /* We cannot deduce in the other direction, because ARG2 is
20486 a pack expansion but ARG1 is not.*/
20492 /* The normal case, where neither argument is a pack
20494 deduce1 = (unify (tparms1, targs1, arg1, arg2,
20495 UNIFY_ALLOW_NONE, /*explain_p=*/false)
20497 deduce2 = (unify (tparms2, targs2, arg2, arg1,
20498 UNIFY_ALLOW_NONE, /*explain_p=*/false)
20502 /* If we couldn't deduce arguments for tparms1 to make arg1 match
20503 arg2, then arg2 is not as specialized as arg1. */
20509 /* "If, for a given type, deduction succeeds in both directions
20510 (i.e., the types are identical after the transformations above)
20511 and both P and A were reference types (before being replaced with
20512 the type referred to above):
20513 - if the type from the argument template was an lvalue reference and
20514 the type from the parameter template was not, the argument type is
20515 considered to be more specialized than the other; otherwise,
20516 - if the type from the argument template is more cv-qualified
20517 than the type from the parameter template (as described above),
20518 the argument type is considered to be more specialized than the other;
20520 - neither type is more specialized than the other." */
20522 if (deduce1 && deduce2)
20524 if (ref1 && ref2 && ref1 != ref2)
20531 else if (quals1 != quals2 && quals1 >= 0 && quals2 >= 0)
20533 if ((quals1 & quals2) == quals2)
20535 if ((quals1 & quals2) == quals1)
20540 if (lose1 && lose2)
20541 /* We've failed to deduce something in either direction.
20542 These must be unordered. */
20545 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
20546 || TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
20547 /* We have already processed all of the arguments in our
20548 handing of the pack expansion type. */
20551 args1 = TREE_CHAIN (args1);
20552 args2 = TREE_CHAIN (args2);
20555 /* "In most cases, all template parameters must have values in order for
20556 deduction to succeed, but for partial ordering purposes a template
20557 parameter may remain without a value provided it is not used in the
20558 types being used for partial ordering."
20560 Thus, if we are missing any of the targs1 we need to substitute into
20561 origs1, then pat2 is not as specialized as pat1. This can happen when
20562 there is a nondeduced context. */
20563 if (!lose2 && check_undeduced_parms (targs1, origs1, args1))
20565 if (!lose1 && check_undeduced_parms (targs2, origs2, args2))
20568 processing_template_decl--;
20570 /* If both deductions succeed, the partial ordering selects the more
20571 constrained template. */
20572 if (!lose1 && !lose2)
20574 tree c1 = get_constraints (DECL_TEMPLATE_RESULT (pat1));
20575 tree c2 = get_constraints (DECL_TEMPLATE_RESULT (pat2));
20576 lose1 = !subsumes_constraints (c1, c2);
20577 lose2 = !subsumes_constraints (c2, c1);
20580 /* All things being equal, if the next argument is a pack expansion
20581 for one function but not for the other, prefer the
20582 non-variadic function. FIXME this is bogus; see c++/41958. */
20584 && args1 && TREE_VALUE (args1)
20585 && args2 && TREE_VALUE (args2))
20587 lose1 = TREE_CODE (TREE_VALUE (args1)) == TYPE_PACK_EXPANSION;
20588 lose2 = TREE_CODE (TREE_VALUE (args2)) == TYPE_PACK_EXPANSION;
20591 if (lose1 == lose2)
20599 /* Determine which of two partial specializations of TMPL is more
20602 PAT1 is a TREE_LIST whose TREE_VALUE is the TEMPLATE_DECL corresponding
20603 to the first partial specialization. The TREE_PURPOSE is the
20604 innermost set of template parameters for the partial
20605 specialization. PAT2 is similar, but for the second template.
20607 Return 1 if the first partial specialization is more specialized;
20608 -1 if the second is more specialized; 0 if neither is more
20611 See [temp.class.order] for information about determining which of
20612 two templates is more specialized. */
20615 more_specialized_partial_spec (tree tmpl, tree pat1, tree pat2)
20619 bool any_deductions = false;
20621 tree tmpl1 = TREE_VALUE (pat1);
20622 tree tmpl2 = TREE_VALUE (pat2);
20623 tree parms1 = DECL_INNERMOST_TEMPLATE_PARMS (tmpl1);
20624 tree parms2 = DECL_INNERMOST_TEMPLATE_PARMS (tmpl2);
20625 tree specargs1 = TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (tmpl1)));
20626 tree specargs2 = TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (tmpl2)));
20628 /* Just like what happens for functions, if we are ordering between
20629 different template specializations, we may encounter dependent
20630 types in the arguments, and we need our dependency check functions
20631 to behave correctly. */
20632 ++processing_template_decl;
20633 targs = get_partial_spec_bindings (tmpl, parms1, specargs1, specargs2);
20637 any_deductions = true;
20640 targs = get_partial_spec_bindings (tmpl, parms2, specargs2, specargs1);
20644 any_deductions = true;
20646 --processing_template_decl;
20648 /* If both deductions succeed, the partial ordering selects the more
20649 constrained template. */
20650 if (!winner && any_deductions)
20651 return more_constrained (tmpl1, tmpl2);
20653 /* In the case of a tie where at least one of the templates
20654 has a parameter pack at the end, the template with the most
20655 non-packed parameters wins. */
20658 && (template_args_variadic_p (TREE_PURPOSE (pat1))
20659 || template_args_variadic_p (TREE_PURPOSE (pat2))))
20661 tree args1 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat1));
20662 tree args2 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat2));
20663 int len1 = TREE_VEC_LENGTH (args1);
20664 int len2 = TREE_VEC_LENGTH (args2);
20666 /* We don't count the pack expansion at the end. */
20667 if (template_args_variadic_p (TREE_PURPOSE (pat1)))
20669 if (template_args_variadic_p (TREE_PURPOSE (pat2)))
20674 else if (len1 < len2)
20681 /* Return the template arguments that will produce the function signature
20682 DECL from the function template FN, with the explicit template
20683 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
20684 also match. Return NULL_TREE if no satisfactory arguments could be
20688 get_bindings (tree fn, tree decl, tree explicit_args, bool check_rettype)
20690 int ntparms = DECL_NTPARMS (fn);
20691 tree targs = make_tree_vec (ntparms);
20692 tree decl_type = TREE_TYPE (decl);
20693 tree decl_arg_types;
20695 unsigned int nargs, ix;
20698 gcc_assert (decl != DECL_TEMPLATE_RESULT (fn));
20700 /* Never do unification on the 'this' parameter. */
20701 decl_arg_types = skip_artificial_parms_for (decl,
20702 TYPE_ARG_TYPES (decl_type));
20704 nargs = list_length (decl_arg_types);
20705 args = XALLOCAVEC (tree, nargs);
20706 for (arg = decl_arg_types, ix = 0;
20707 arg != NULL_TREE && arg != void_list_node;
20708 arg = TREE_CHAIN (arg), ++ix)
20709 args[ix] = TREE_VALUE (arg);
20711 if (fn_type_unification (fn, explicit_args, targs,
20713 (check_rettype || DECL_CONV_FN_P (fn)
20714 ? TREE_TYPE (decl_type) : NULL_TREE),
20715 DEDUCE_EXACT, LOOKUP_NORMAL, /*explain_p=*/false,
20717 == error_mark_node)
20723 /* Return the innermost template arguments that, when applied to a partial
20724 specialization of TMPL whose innermost template parameters are
20725 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
20728 For example, suppose we have:
20730 template <class T, class U> struct S {};
20731 template <class T> struct S<T*, int> {};
20733 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
20734 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
20735 int}. The resulting vector will be {double}, indicating that `T'
20736 is bound to `double'. */
20739 get_partial_spec_bindings (tree tmpl, tree tparms, tree spec_args, tree args)
20741 int i, ntparms = TREE_VEC_LENGTH (tparms);
20743 tree innermost_deduced_args;
20745 innermost_deduced_args = make_tree_vec (ntparms);
20746 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
20748 deduced_args = copy_node (args);
20749 SET_TMPL_ARGS_LEVEL (deduced_args,
20750 TMPL_ARGS_DEPTH (deduced_args),
20751 innermost_deduced_args);
20754 deduced_args = innermost_deduced_args;
20756 if (unify (tparms, deduced_args,
20757 INNERMOST_TEMPLATE_ARGS (spec_args),
20758 INNERMOST_TEMPLATE_ARGS (args),
20759 UNIFY_ALLOW_NONE, /*explain_p=*/false))
20762 for (i = 0; i < ntparms; ++i)
20763 if (! TREE_VEC_ELT (innermost_deduced_args, i))
20766 /* Verify that nondeduced template arguments agree with the type
20767 obtained from argument deduction.
20771 struct A { typedef int X; };
20772 template <class T, class U> struct C {};
20773 template <class T> struct C<T, typename T::X> {};
20775 Then with the instantiation `C<A, int>', we can deduce that
20776 `T' is `A' but unify () does not check whether `typename T::X'
20778 spec_args = tsubst (spec_args, deduced_args, tf_none, NULL_TREE);
20779 spec_args = coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
20781 tf_none, false, false);
20782 if (spec_args == error_mark_node
20783 /* We only need to check the innermost arguments; the other
20784 arguments will always agree. */
20785 || !comp_template_args (INNERMOST_TEMPLATE_ARGS (spec_args),
20786 INNERMOST_TEMPLATE_ARGS (args)))
20789 /* Now that we have bindings for all of the template arguments,
20790 ensure that the arguments deduced for the template template
20791 parameters have compatible template parameter lists. See the use
20792 of template_template_parm_bindings_ok_p in fn_type_unification
20793 for more information. */
20794 if (!template_template_parm_bindings_ok_p (tparms, deduced_args))
20797 return deduced_args;
20800 // Compare two function templates T1 and T2 by deducing bindings
20801 // from one against the other. If both deductions succeed, compare
20802 // constraints to see which is more constrained.
20804 more_specialized_inst (tree t1, tree t2)
20809 if (get_bindings (t1, DECL_TEMPLATE_RESULT (t2), NULL_TREE, true))
20815 if (get_bindings (t2, DECL_TEMPLATE_RESULT (t1), NULL_TREE, true))
20821 // If both deductions succeed, then one may be more constrained.
20822 if (count == 2 && fate == 0)
20823 fate = more_constrained (t1, t2);
20828 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
20829 Return the TREE_LIST node with the most specialized template, if
20830 any. If there is no most specialized template, the error_mark_node
20833 Note that this function does not look at, or modify, the
20834 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
20835 returned is one of the elements of INSTANTIATIONS, callers may
20836 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
20837 and retrieve it from the value returned. */
20840 most_specialized_instantiation (tree templates)
20844 ++processing_template_decl;
20847 for (fn = TREE_CHAIN (templates); fn; fn = TREE_CHAIN (fn))
20849 int fate = more_specialized_inst (TREE_VALUE (champ), TREE_VALUE (fn));
20854 /* Equally specialized, move to next function. If there
20855 is no next function, nothing's most specialized. */
20856 fn = TREE_CHAIN (fn);
20864 /* Now verify that champ is better than everything earlier in the
20865 instantiation list. */
20866 for (fn = templates; fn != champ; fn = TREE_CHAIN (fn)) {
20867 if (more_specialized_inst (TREE_VALUE (champ), TREE_VALUE (fn)) != 1)
20874 processing_template_decl--;
20877 return error_mark_node;
20882 /* If DECL is a specialization of some template, return the most
20883 general such template. Otherwise, returns NULL_TREE.
20885 For example, given:
20887 template <class T> struct S { template <class U> void f(U); };
20889 if TMPL is `template <class U> void S<int>::f(U)' this will return
20890 the full template. This function will not trace past partial
20891 specializations, however. For example, given in addition:
20893 template <class T> struct S<T*> { template <class U> void f(U); };
20895 if TMPL is `template <class U> void S<int*>::f(U)' this will return
20896 `template <class T> template <class U> S<T*>::f(U)'. */
20899 most_general_template (tree decl)
20901 if (TREE_CODE (decl) != TEMPLATE_DECL)
20903 if (tree tinfo = get_template_info (decl))
20904 decl = TI_TEMPLATE (tinfo);
20905 /* The TI_TEMPLATE can be an IDENTIFIER_NODE for a
20906 template friend, or a FIELD_DECL for a capture pack. */
20907 if (TREE_CODE (decl) != TEMPLATE_DECL)
20911 /* Look for more and more general templates. */
20912 while (DECL_LANG_SPECIFIC (decl) && DECL_TEMPLATE_INFO (decl))
20914 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
20915 (See cp-tree.h for details.) */
20916 if (TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
20919 if (CLASS_TYPE_P (TREE_TYPE (decl))
20920 && !TYPE_DECL_ALIAS_P (TYPE_NAME (TREE_TYPE (decl)))
20921 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)))
20924 /* Stop if we run into an explicitly specialized class template. */
20925 if (!DECL_NAMESPACE_SCOPE_P (decl)
20926 && DECL_CONTEXT (decl)
20927 && CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (decl)))
20930 decl = DECL_TI_TEMPLATE (decl);
20936 /* Return the most specialized of the template partial specializations
20937 which can produce TARGET, a specialization of some class or variable
20938 template. The value returned is actually a TREE_LIST; the TREE_VALUE is
20939 a TEMPLATE_DECL node corresponding to the partial specialization, while
20940 the TREE_PURPOSE is the set of template arguments that must be
20941 substituted into the template pattern in order to generate TARGET.
20943 If the choice of partial specialization is ambiguous, a diagnostic
20944 is issued, and the error_mark_node is returned. If there are no
20945 partial specializations matching TARGET, then NULL_TREE is
20946 returned, indicating that the primary template should be used. */
20949 most_specialized_partial_spec (tree target, tsubst_flags_t complain)
20951 tree list = NULL_TREE;
20956 tree outer_args = NULL_TREE;
20959 if (TYPE_P (target))
20961 tree tinfo = CLASSTYPE_TEMPLATE_INFO (target);
20962 tmpl = TI_TEMPLATE (tinfo);
20963 args = TI_ARGS (tinfo);
20965 else if (TREE_CODE (target) == TEMPLATE_ID_EXPR)
20967 tmpl = TREE_OPERAND (target, 0);
20968 args = TREE_OPERAND (target, 1);
20970 else if (VAR_P (target))
20972 tree tinfo = DECL_TEMPLATE_INFO (target);
20973 tmpl = TI_TEMPLATE (tinfo);
20974 args = TI_ARGS (tinfo);
20977 gcc_unreachable ();
20979 tree main_tmpl = most_general_template (tmpl);
20981 /* For determining which partial specialization to use, only the
20982 innermost args are interesting. */
20983 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
20985 outer_args = strip_innermost_template_args (args, 1);
20986 args = INNERMOST_TEMPLATE_ARGS (args);
20989 for (t = DECL_TEMPLATE_SPECIALIZATIONS (main_tmpl); t; t = TREE_CHAIN (t))
20991 tree partial_spec_args;
20993 tree spec_tmpl = TREE_VALUE (t);
20995 partial_spec_args = TREE_PURPOSE (t);
20997 ++processing_template_decl;
21001 /* Discard the outer levels of args, and then substitute in the
21002 template args from the enclosing class. */
21003 partial_spec_args = INNERMOST_TEMPLATE_ARGS (partial_spec_args);
21004 partial_spec_args = tsubst_template_args
21005 (partial_spec_args, outer_args, tf_none, NULL_TREE);
21007 /* And the same for the partial specialization TEMPLATE_DECL. */
21008 spec_tmpl = tsubst (spec_tmpl, outer_args, tf_none, NULL_TREE);
21011 partial_spec_args =
21012 coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
21015 /*require_all_args=*/true,
21016 /*use_default_args=*/true);
21018 --processing_template_decl;
21020 if (partial_spec_args == error_mark_node)
21021 return error_mark_node;
21022 if (spec_tmpl == error_mark_node)
21023 return error_mark_node;
21025 tree parms = DECL_INNERMOST_TEMPLATE_PARMS (spec_tmpl);
21026 spec_args = get_partial_spec_bindings (tmpl, parms,
21032 spec_args = add_to_template_args (outer_args, spec_args);
21034 /* Keep the candidate only if the constraints are satisfied,
21035 or if we're not compiling with concepts. */
21037 || constraints_satisfied_p (spec_tmpl, spec_args))
21039 list = tree_cons (spec_args, TREE_VALUE (t), list);
21040 TREE_TYPE (list) = TREE_TYPE (t);
21048 ambiguous_p = false;
21051 t = TREE_CHAIN (t);
21052 for (; t; t = TREE_CHAIN (t))
21054 fate = more_specialized_partial_spec (tmpl, champ, t);
21061 t = TREE_CHAIN (t);
21064 ambiguous_p = true;
21073 for (t = list; t && t != champ; t = TREE_CHAIN (t))
21075 fate = more_specialized_partial_spec (tmpl, champ, t);
21078 ambiguous_p = true;
21086 char *spaces = NULL;
21087 if (!(complain & tf_error))
21088 return error_mark_node;
21089 if (TYPE_P (target))
21090 error ("ambiguous template instantiation for %q#T", target);
21092 error ("ambiguous template instantiation for %q#D", target);
21093 str = ngettext ("candidate is:", "candidates are:", list_length (list));
21094 for (t = list; t; t = TREE_CHAIN (t))
21096 tree subst = build_tree_list (TREE_VALUE (t), TREE_PURPOSE (t));
21097 inform (DECL_SOURCE_LOCATION (TREE_VALUE (t)),
21098 "%s %#S", spaces ? spaces : str, subst);
21099 spaces = spaces ? spaces : get_spaces (str);
21102 return error_mark_node;
21108 /* Explicitly instantiate DECL. */
21111 do_decl_instantiation (tree decl, tree storage)
21113 tree result = NULL_TREE;
21116 if (!decl || decl == error_mark_node)
21117 /* An error occurred, for which grokdeclarator has already issued
21118 an appropriate message. */
21120 else if (! DECL_LANG_SPECIFIC (decl))
21122 error ("explicit instantiation of non-template %q#D", decl);
21126 bool var_templ = (DECL_TEMPLATE_INFO (decl)
21127 && variable_template_p (DECL_TI_TEMPLATE (decl)));
21129 if (VAR_P (decl) && !var_templ)
21131 /* There is an asymmetry here in the way VAR_DECLs and
21132 FUNCTION_DECLs are handled by grokdeclarator. In the case of
21133 the latter, the DECL we get back will be marked as a
21134 template instantiation, and the appropriate
21135 DECL_TEMPLATE_INFO will be set up. This does not happen for
21136 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
21137 should handle VAR_DECLs as it currently handles
21139 if (!DECL_CLASS_SCOPE_P (decl))
21141 error ("%qD is not a static data member of a class template", decl);
21144 result = lookup_field (DECL_CONTEXT (decl), DECL_NAME (decl), 0, false);
21145 if (!result || !VAR_P (result))
21147 error ("no matching template for %qD found", decl);
21150 if (!same_type_p (TREE_TYPE (result), TREE_TYPE (decl)))
21152 error ("type %qT for explicit instantiation %qD does not match "
21153 "declared type %qT", TREE_TYPE (result), decl,
21158 else if (TREE_CODE (decl) != FUNCTION_DECL && !var_templ)
21160 error ("explicit instantiation of %q#D", decl);
21166 /* Check for various error cases. Note that if the explicit
21167 instantiation is valid the RESULT will currently be marked as an
21168 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
21169 until we get here. */
21171 if (DECL_TEMPLATE_SPECIALIZATION (result))
21173 /* DR 259 [temp.spec].
21175 Both an explicit instantiation and a declaration of an explicit
21176 specialization shall not appear in a program unless the explicit
21177 instantiation follows a declaration of the explicit specialization.
21179 For a given set of template parameters, if an explicit
21180 instantiation of a template appears after a declaration of an
21181 explicit specialization for that template, the explicit
21182 instantiation has no effect. */
21185 else if (DECL_EXPLICIT_INSTANTIATION (result))
21189 No program shall explicitly instantiate any template more
21192 We check DECL_NOT_REALLY_EXTERN so as not to complain when
21193 the first instantiation was `extern' and the second is not,
21194 and EXTERN_P for the opposite case. */
21195 if (DECL_NOT_REALLY_EXTERN (result) && !extern_p)
21196 permerror (input_location, "duplicate explicit instantiation of %q#D", result);
21197 /* If an "extern" explicit instantiation follows an ordinary
21198 explicit instantiation, the template is instantiated. */
21202 else if (!DECL_IMPLICIT_INSTANTIATION (result))
21204 error ("no matching template for %qD found", result);
21207 else if (!DECL_TEMPLATE_INFO (result))
21209 permerror (input_location, "explicit instantiation of non-template %q#D", result);
21213 if (storage == NULL_TREE)
21215 else if (storage == ridpointers[(int) RID_EXTERN])
21217 if (!in_system_header_at (input_location) && (cxx_dialect == cxx98))
21218 pedwarn (input_location, OPT_Wpedantic,
21219 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
21224 error ("storage class %qD applied to template instantiation", storage);
21226 check_explicit_instantiation_namespace (result);
21227 mark_decl_instantiated (result, extern_p);
21229 instantiate_decl (result, /*defer_ok=*/1,
21230 /*expl_inst_class_mem_p=*/false);
21234 mark_class_instantiated (tree t, int extern_p)
21236 SET_CLASSTYPE_EXPLICIT_INSTANTIATION (t);
21237 SET_CLASSTYPE_INTERFACE_KNOWN (t);
21238 CLASSTYPE_INTERFACE_ONLY (t) = extern_p;
21239 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (t)) = extern_p;
21242 CLASSTYPE_DEBUG_REQUESTED (t) = 1;
21243 rest_of_type_compilation (t, 1);
21247 /* Called from do_type_instantiation through binding_table_foreach to
21248 do recursive instantiation for the type bound in ENTRY. */
21250 bt_instantiate_type_proc (binding_entry entry, void *data)
21252 tree storage = *(tree *) data;
21254 if (MAYBE_CLASS_TYPE_P (entry->type)
21255 && !uses_template_parms (CLASSTYPE_TI_ARGS (entry->type)))
21256 do_type_instantiation (TYPE_MAIN_DECL (entry->type), storage, 0);
21259 /* Called from do_type_instantiation to instantiate a member
21260 (a member function or a static member variable) of an
21261 explicitly instantiated class template. */
21263 instantiate_class_member (tree decl, int extern_p)
21265 mark_decl_instantiated (decl, extern_p);
21267 instantiate_decl (decl, /*defer_ok=*/1,
21268 /*expl_inst_class_mem_p=*/true);
21271 /* Perform an explicit instantiation of template class T. STORAGE, if
21272 non-null, is the RID for extern, inline or static. COMPLAIN is
21273 nonzero if this is called from the parser, zero if called recursively,
21274 since the standard is unclear (as detailed below). */
21277 do_type_instantiation (tree t, tree storage, tsubst_flags_t complain)
21282 int previous_instantiation_extern_p = 0;
21284 if (TREE_CODE (t) == TYPE_DECL)
21287 if (! CLASS_TYPE_P (t) || ! CLASSTYPE_TEMPLATE_INFO (t))
21290 (TYPE_TEMPLATE_INFO (t)) ? TYPE_TI_TEMPLATE (t) : NULL;
21292 error ("explicit instantiation of non-class template %qD", tmpl);
21294 error ("explicit instantiation of non-template type %qT", t);
21300 if (!COMPLETE_TYPE_P (t))
21302 if (complain & tf_error)
21303 error ("explicit instantiation of %q#T before definition of template",
21308 if (storage != NULL_TREE)
21310 if (!in_system_header_at (input_location))
21312 if (storage == ridpointers[(int) RID_EXTERN])
21314 if (cxx_dialect == cxx98)
21315 pedwarn (input_location, OPT_Wpedantic,
21316 "ISO C++ 1998 forbids the use of %<extern%> on "
21317 "explicit instantiations");
21320 pedwarn (input_location, OPT_Wpedantic,
21321 "ISO C++ forbids the use of %qE"
21322 " on explicit instantiations", storage);
21325 if (storage == ridpointers[(int) RID_INLINE])
21327 else if (storage == ridpointers[(int) RID_EXTERN])
21329 else if (storage == ridpointers[(int) RID_STATIC])
21333 error ("storage class %qD applied to template instantiation",
21339 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (t))
21341 /* DR 259 [temp.spec].
21343 Both an explicit instantiation and a declaration of an explicit
21344 specialization shall not appear in a program unless the explicit
21345 instantiation follows a declaration of the explicit specialization.
21347 For a given set of template parameters, if an explicit
21348 instantiation of a template appears after a declaration of an
21349 explicit specialization for that template, the explicit
21350 instantiation has no effect. */
21353 else if (CLASSTYPE_EXPLICIT_INSTANTIATION (t))
21357 No program shall explicitly instantiate any template more
21360 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
21361 instantiation was `extern'. If EXTERN_P then the second is.
21362 These cases are OK. */
21363 previous_instantiation_extern_p = CLASSTYPE_INTERFACE_ONLY (t);
21365 if (!previous_instantiation_extern_p && !extern_p
21366 && (complain & tf_error))
21367 permerror (input_location, "duplicate explicit instantiation of %q#T", t);
21369 /* If we've already instantiated the template, just return now. */
21370 if (!CLASSTYPE_INTERFACE_ONLY (t))
21374 check_explicit_instantiation_namespace (TYPE_NAME (t));
21375 mark_class_instantiated (t, extern_p);
21383 /* In contrast to implicit instantiation, where only the
21384 declarations, and not the definitions, of members are
21385 instantiated, we have here:
21389 The explicit instantiation of a class template specialization
21390 implies the instantiation of all of its members not
21391 previously explicitly specialized in the translation unit
21392 containing the explicit instantiation.
21394 Of course, we can't instantiate member template classes, since
21395 we don't have any arguments for them. Note that the standard
21396 is unclear on whether the instantiation of the members are
21397 *explicit* instantiations or not. However, the most natural
21398 interpretation is that it should be an explicit instantiation. */
21401 for (tmp = TYPE_METHODS (t); tmp; tmp = DECL_CHAIN (tmp))
21402 if (TREE_CODE (tmp) == FUNCTION_DECL
21403 && DECL_TEMPLATE_INSTANTIATION (tmp)
21404 && (!extern_p || user_provided_p (tmp)))
21405 instantiate_class_member (tmp, extern_p);
21407 for (tmp = TYPE_FIELDS (t); tmp; tmp = DECL_CHAIN (tmp))
21408 if (VAR_P (tmp) && DECL_TEMPLATE_INSTANTIATION (tmp))
21409 instantiate_class_member (tmp, extern_p);
21411 if (CLASSTYPE_NESTED_UTDS (t))
21412 binding_table_foreach (CLASSTYPE_NESTED_UTDS (t),
21413 bt_instantiate_type_proc, &storage);
21417 /* Given a function DECL, which is a specialization of TMPL, modify
21418 DECL to be a re-instantiation of TMPL with the same template
21419 arguments. TMPL should be the template into which tsubst'ing
21420 should occur for DECL, not the most general template.
21422 One reason for doing this is a scenario like this:
21425 void f(const T&, int i);
21427 void g() { f(3, 7); }
21430 void f(const T& t, const int i) { }
21432 Note that when the template is first instantiated, with
21433 instantiate_template, the resulting DECL will have no name for the
21434 first parameter, and the wrong type for the second. So, when we go
21435 to instantiate the DECL, we regenerate it. */
21438 regenerate_decl_from_template (tree decl, tree tmpl, tree args)
21440 /* The arguments used to instantiate DECL, from the most general
21444 code_pattern = DECL_TEMPLATE_RESULT (tmpl);
21446 /* Make sure that we can see identifiers, and compute access
21448 push_access_scope (decl);
21450 if (TREE_CODE (decl) == FUNCTION_DECL)
21458 args_depth = TMPL_ARGS_DEPTH (args);
21459 parms_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
21460 if (args_depth > parms_depth)
21461 args = get_innermost_template_args (args, parms_depth);
21463 specs = tsubst_exception_specification (TREE_TYPE (code_pattern),
21464 args, tf_error, NULL_TREE,
21465 /*defer_ok*/false);
21466 if (specs && specs != error_mark_node)
21467 TREE_TYPE (decl) = build_exception_variant (TREE_TYPE (decl),
21470 /* Merge parameter declarations. */
21471 decl_parm = skip_artificial_parms_for (decl,
21472 DECL_ARGUMENTS (decl));
21474 = skip_artificial_parms_for (code_pattern,
21475 DECL_ARGUMENTS (code_pattern));
21476 while (decl_parm && !DECL_PACK_P (pattern_parm))
21481 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
21482 DECL_NAME (decl_parm) = DECL_NAME (pattern_parm);
21483 parm_type = tsubst (TREE_TYPE (pattern_parm), args, tf_error,
21485 parm_type = type_decays_to (parm_type);
21486 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
21487 TREE_TYPE (decl_parm) = parm_type;
21488 attributes = DECL_ATTRIBUTES (pattern_parm);
21489 if (DECL_ATTRIBUTES (decl_parm) != attributes)
21491 DECL_ATTRIBUTES (decl_parm) = attributes;
21492 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
21494 decl_parm = DECL_CHAIN (decl_parm);
21495 pattern_parm = DECL_CHAIN (pattern_parm);
21497 /* Merge any parameters that match with the function parameter
21499 if (pattern_parm && DECL_PACK_P (pattern_parm))
21502 tree expanded_types;
21503 /* Expand the TYPE_PACK_EXPANSION that provides the types for
21504 the parameters in this function parameter pack. */
21505 expanded_types = tsubst_pack_expansion (TREE_TYPE (pattern_parm),
21506 args, tf_error, NULL_TREE);
21507 len = TREE_VEC_LENGTH (expanded_types);
21508 for (i = 0; i < len; i++)
21513 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
21514 /* Rename the parameter to include the index. */
21515 DECL_NAME (decl_parm) =
21516 make_ith_pack_parameter_name (DECL_NAME (pattern_parm), i);
21517 parm_type = TREE_VEC_ELT (expanded_types, i);
21518 parm_type = type_decays_to (parm_type);
21519 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
21520 TREE_TYPE (decl_parm) = parm_type;
21521 attributes = DECL_ATTRIBUTES (pattern_parm);
21522 if (DECL_ATTRIBUTES (decl_parm) != attributes)
21524 DECL_ATTRIBUTES (decl_parm) = attributes;
21525 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
21527 decl_parm = DECL_CHAIN (decl_parm);
21530 /* Merge additional specifiers from the CODE_PATTERN. */
21531 if (DECL_DECLARED_INLINE_P (code_pattern)
21532 && !DECL_DECLARED_INLINE_P (decl))
21533 DECL_DECLARED_INLINE_P (decl) = 1;
21535 else if (VAR_P (decl))
21537 DECL_INITIAL (decl) =
21538 tsubst_expr (DECL_INITIAL (code_pattern), args,
21539 tf_error, DECL_TI_TEMPLATE (decl),
21540 /*integral_constant_expression_p=*/false);
21541 if (VAR_HAD_UNKNOWN_BOUND (decl))
21542 TREE_TYPE (decl) = tsubst (TREE_TYPE (code_pattern), args,
21543 tf_error, DECL_TI_TEMPLATE (decl));
21546 gcc_unreachable ();
21548 pop_access_scope (decl);
21551 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
21552 substituted to get DECL. */
21555 template_for_substitution (tree decl)
21557 tree tmpl = DECL_TI_TEMPLATE (decl);
21559 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
21560 for the instantiation. This is not always the most general
21561 template. Consider, for example:
21564 struct S { template <class U> void f();
21565 template <> void f<int>(); };
21567 and an instantiation of S<double>::f<int>. We want TD to be the
21568 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
21569 while (/* An instantiation cannot have a definition, so we need a
21570 more general template. */
21571 DECL_TEMPLATE_INSTANTIATION (tmpl)
21572 /* We must also deal with friend templates. Given:
21574 template <class T> struct S {
21575 template <class U> friend void f() {};
21578 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
21579 so far as the language is concerned, but that's still
21580 where we get the pattern for the instantiation from. On
21581 other hand, if the definition comes outside the class, say:
21583 template <class T> struct S {
21584 template <class U> friend void f();
21586 template <class U> friend void f() {}
21588 we don't need to look any further. That's what the check for
21589 DECL_INITIAL is for. */
21590 || (TREE_CODE (decl) == FUNCTION_DECL
21591 && DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION (tmpl)
21592 && !DECL_INITIAL (DECL_TEMPLATE_RESULT (tmpl))))
21594 /* The present template, TD, should not be a definition. If it
21595 were a definition, we should be using it! Note that we
21596 cannot restructure the loop to just keep going until we find
21597 a template with a definition, since that might go too far if
21598 a specialization was declared, but not defined. */
21600 /* Fetch the more general template. */
21601 tmpl = DECL_TI_TEMPLATE (tmpl);
21607 /* Returns true if we need to instantiate this template instance even if we
21608 know we aren't going to emit it. */
21611 always_instantiate_p (tree decl)
21613 /* We always instantiate inline functions so that we can inline them. An
21614 explicit instantiation declaration prohibits implicit instantiation of
21615 non-inline functions. With high levels of optimization, we would
21616 normally inline non-inline functions -- but we're not allowed to do
21617 that for "extern template" functions. Therefore, we check
21618 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
21619 return ((TREE_CODE (decl) == FUNCTION_DECL
21620 && (DECL_DECLARED_INLINE_P (decl)
21621 || type_uses_auto (TREE_TYPE (TREE_TYPE (decl)))))
21622 /* And we need to instantiate static data members so that
21623 their initializers are available in integral constant
21626 && decl_maybe_constant_var_p (decl)));
21629 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
21630 instantiate it now, modifying TREE_TYPE (fn). */
21633 maybe_instantiate_noexcept (tree fn)
21635 tree fntype, spec, noex, clone;
21637 /* Don't instantiate a noexcept-specification from template context. */
21638 if (processing_template_decl)
21641 if (DECL_CLONED_FUNCTION_P (fn))
21642 fn = DECL_CLONED_FUNCTION (fn);
21643 fntype = TREE_TYPE (fn);
21644 spec = TYPE_RAISES_EXCEPTIONS (fntype);
21646 if (!spec || !TREE_PURPOSE (spec))
21649 noex = TREE_PURPOSE (spec);
21651 if (TREE_CODE (noex) == DEFERRED_NOEXCEPT)
21653 if (DEFERRED_NOEXCEPT_PATTERN (noex) == NULL_TREE)
21654 spec = get_defaulted_eh_spec (fn);
21655 else if (push_tinst_level (fn))
21657 push_access_scope (fn);
21658 push_deferring_access_checks (dk_no_deferred);
21659 input_location = DECL_SOURCE_LOCATION (fn);
21660 noex = tsubst_copy_and_build (DEFERRED_NOEXCEPT_PATTERN (noex),
21661 DEFERRED_NOEXCEPT_ARGS (noex),
21662 tf_warning_or_error, fn,
21663 /*function_p=*/false,
21664 /*integral_constant_expression_p=*/true);
21665 pop_deferring_access_checks ();
21666 pop_access_scope (fn);
21667 pop_tinst_level ();
21668 spec = build_noexcept_spec (noex, tf_warning_or_error);
21669 if (spec == error_mark_node)
21670 spec = noexcept_false_spec;
21673 spec = noexcept_false_spec;
21675 TREE_TYPE (fn) = build_exception_variant (fntype, spec);
21678 FOR_EACH_CLONE (clone, fn)
21680 if (TREE_TYPE (clone) == fntype)
21681 TREE_TYPE (clone) = TREE_TYPE (fn);
21683 TREE_TYPE (clone) = build_exception_variant (TREE_TYPE (clone), spec);
21687 /* Produce the definition of D, a _DECL generated from a template. If
21688 DEFER_OK is nonzero, then we don't have to actually do the
21689 instantiation now; we just have to do it sometime. Normally it is
21690 an error if this is an explicit instantiation but D is undefined.
21691 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
21692 explicitly instantiated class template. */
21695 instantiate_decl (tree d, int defer_ok,
21696 bool expl_inst_class_mem_p)
21698 tree tmpl = DECL_TI_TEMPLATE (d);
21705 bool pattern_defined;
21706 location_t saved_loc = input_location;
21707 int saved_unevaluated_operand = cp_unevaluated_operand;
21708 int saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
21712 bool nested = false;
21714 /* This function should only be used to instantiate templates for
21715 functions and static member variables. */
21716 gcc_assert (VAR_OR_FUNCTION_DECL_P (d));
21718 /* A concept is never instantiated. */
21719 gcc_assert (!DECL_DECLARED_CONCEPT_P (d));
21721 /* Variables are never deferred; if instantiation is required, they
21722 are instantiated right away. That allows for better code in the
21723 case that an expression refers to the value of the variable --
21724 if the variable has a constant value the referring expression can
21725 take advantage of that fact. */
21727 || DECL_DECLARED_CONSTEXPR_P (d))
21730 /* Don't instantiate cloned functions. Instead, instantiate the
21731 functions they cloned. */
21732 if (TREE_CODE (d) == FUNCTION_DECL && DECL_CLONED_FUNCTION_P (d))
21733 d = DECL_CLONED_FUNCTION (d);
21735 if (DECL_TEMPLATE_INSTANTIATED (d)
21736 || (TREE_CODE (d) == FUNCTION_DECL
21737 && DECL_DEFAULTED_FN (d) && DECL_INITIAL (d))
21738 || DECL_TEMPLATE_SPECIALIZATION (d))
21739 /* D has already been instantiated or explicitly specialized, so
21740 there's nothing for us to do here.
21742 It might seem reasonable to check whether or not D is an explicit
21743 instantiation, and, if so, stop here. But when an explicit
21744 instantiation is deferred until the end of the compilation,
21745 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
21746 the instantiation. */
21749 /* Check to see whether we know that this template will be
21750 instantiated in some other file, as with "extern template"
21752 external_p = (DECL_INTERFACE_KNOWN (d) && DECL_REALLY_EXTERN (d));
21754 /* In general, we do not instantiate such templates. */
21755 if (external_p && !always_instantiate_p (d))
21758 gen_tmpl = most_general_template (tmpl);
21759 gen_args = DECL_TI_ARGS (d);
21761 if (tmpl != gen_tmpl)
21762 /* We should already have the extra args. */
21763 gcc_assert (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (gen_tmpl))
21764 == TMPL_ARGS_DEPTH (gen_args));
21765 /* And what's in the hash table should match D. */
21766 gcc_assert ((spec = retrieve_specialization (gen_tmpl, gen_args, 0)) == d
21767 || spec == NULL_TREE);
21769 /* This needs to happen before any tsubsting. */
21770 if (! push_tinst_level (d))
21773 timevar_push (TV_TEMPLATE_INST);
21775 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
21776 for the instantiation. */
21777 td = template_for_substitution (d);
21782 /* Look up an explicit specialization, if any. */
21783 tree tid = lookup_template_variable (gen_tmpl, gen_args);
21784 tree elt = most_specialized_partial_spec (tid, tf_warning_or_error);
21785 if (elt && elt != error_mark_node)
21787 td = TREE_VALUE (elt);
21788 args = TREE_PURPOSE (elt);
21792 code_pattern = DECL_TEMPLATE_RESULT (td);
21794 /* We should never be trying to instantiate a member of a class
21795 template or partial specialization. */
21796 gcc_assert (d != code_pattern);
21798 if ((DECL_NAMESPACE_SCOPE_P (d) && !DECL_INITIALIZED_IN_CLASS_P (d))
21799 || DECL_TEMPLATE_SPECIALIZATION (td))
21800 /* In the case of a friend template whose definition is provided
21801 outside the class, we may have too many arguments. Drop the
21802 ones we don't need. The same is true for specializations. */
21803 args = get_innermost_template_args
21804 (args, TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (td)));
21806 if (TREE_CODE (d) == FUNCTION_DECL)
21808 deleted_p = DECL_DELETED_FN (code_pattern);
21809 pattern_defined = ((DECL_SAVED_TREE (code_pattern) != NULL_TREE
21810 && DECL_INITIAL (code_pattern) != error_mark_node)
21811 || DECL_DEFAULTED_OUTSIDE_CLASS_P (code_pattern)
21817 if (DECL_CLASS_SCOPE_P (code_pattern))
21818 pattern_defined = ! DECL_IN_AGGR_P (code_pattern);
21820 pattern_defined = ! DECL_EXTERNAL (code_pattern);
21823 /* We may be in the middle of deferred access check. Disable it now. */
21824 push_deferring_access_checks (dk_no_deferred);
21826 /* Unless an explicit instantiation directive has already determined
21827 the linkage of D, remember that a definition is available for
21829 if (pattern_defined
21830 && !DECL_INTERFACE_KNOWN (d)
21831 && !DECL_NOT_REALLY_EXTERN (d))
21832 mark_definable (d);
21834 DECL_SOURCE_LOCATION (td) = DECL_SOURCE_LOCATION (code_pattern);
21835 DECL_SOURCE_LOCATION (d) = DECL_SOURCE_LOCATION (code_pattern);
21836 input_location = DECL_SOURCE_LOCATION (d);
21838 /* If D is a member of an explicitly instantiated class template,
21839 and no definition is available, treat it like an implicit
21841 if (!pattern_defined && expl_inst_class_mem_p
21842 && DECL_EXPLICIT_INSTANTIATION (d))
21844 /* Leave linkage flags alone on instantiations with anonymous
21846 if (TREE_PUBLIC (d))
21848 DECL_NOT_REALLY_EXTERN (d) = 0;
21849 DECL_INTERFACE_KNOWN (d) = 0;
21851 SET_DECL_IMPLICIT_INSTANTIATION (d);
21854 /* Defer all other templates, unless we have been explicitly
21855 forbidden from doing so. */
21856 if (/* If there is no definition, we cannot instantiate the
21859 /* If it's OK to postpone instantiation, do so. */
21861 /* If this is a static data member that will be defined
21862 elsewhere, we don't want to instantiate the entire data
21863 member, but we do want to instantiate the initializer so that
21864 we can substitute that elsewhere. */
21865 || (external_p && VAR_P (d))
21866 /* Handle here a deleted function too, avoid generating
21867 its body (c++/61080). */
21870 /* The definition of the static data member is now required so
21871 we must substitute the initializer. */
21873 && !DECL_INITIAL (d)
21874 && DECL_INITIAL (code_pattern))
21878 bool const_init = false;
21879 bool enter_context = DECL_CLASS_SCOPE_P (d);
21881 ns = decl_namespace_context (d);
21882 push_nested_namespace (ns);
21884 push_nested_class (DECL_CONTEXT (d));
21885 init = tsubst_expr (DECL_INITIAL (code_pattern),
21887 tf_warning_or_error, NULL_TREE,
21888 /*integral_constant_expression_p=*/false);
21889 /* If instantiating the initializer involved instantiating this
21890 again, don't call cp_finish_decl twice. */
21891 if (!DECL_INITIAL (d))
21893 /* Make sure the initializer is still constant, in case of
21894 circular dependency (template/instantiate6.C). */
21896 = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (code_pattern);
21897 cp_finish_decl (d, init, /*init_const_expr_p=*/const_init,
21898 /*asmspec_tree=*/NULL_TREE,
21899 LOOKUP_ONLYCONVERTING);
21902 pop_nested_class ();
21903 pop_nested_namespace (ns);
21906 /* We restore the source position here because it's used by
21907 add_pending_template. */
21908 input_location = saved_loc;
21910 if (at_eof && !pattern_defined
21911 && DECL_EXPLICIT_INSTANTIATION (d)
21912 && DECL_NOT_REALLY_EXTERN (d))
21915 The definition of a non-exported function template, a
21916 non-exported member function template, or a non-exported
21917 member function or static data member of a class template
21918 shall be present in every translation unit in which it is
21919 explicitly instantiated. */
21920 permerror (input_location, "explicit instantiation of %qD "
21921 "but no definition available", d);
21923 /* If we're in unevaluated context, we just wanted to get the
21924 constant value; this isn't an odr use, so don't queue
21925 a full instantiation. */
21926 if (cp_unevaluated_operand != 0)
21928 /* ??? Historically, we have instantiated inline functions, even
21929 when marked as "extern template". */
21930 if (!(external_p && VAR_P (d)))
21931 add_pending_template (d);
21934 /* Tell the repository that D is available in this translation unit
21935 -- and see if it is supposed to be instantiated here. */
21936 if (TREE_PUBLIC (d) && !DECL_REALLY_EXTERN (d) && !repo_emit_p (d))
21938 /* In a PCH file, despite the fact that the repository hasn't
21939 requested instantiation in the PCH it is still possible that
21940 an instantiation will be required in a file that includes the
21943 add_pending_template (d);
21944 /* Instantiate inline functions so that the inliner can do its
21945 job, even though we'll not be emitting a copy of this
21947 if (!(TREE_CODE (d) == FUNCTION_DECL && possibly_inlined_p (d)))
21951 fn_context = decl_function_context (d);
21952 nested = (current_function_decl != NULL_TREE);
21953 vec<tree> omp_privatization_save;
21955 save_omp_privatization_clauses (omp_privatization_save);
21958 push_to_top_level ();
21962 push_function_context ();
21963 cp_unevaluated_operand = 0;
21964 c_inhibit_evaluation_warnings = 0;
21967 /* Mark D as instantiated so that recursive calls to
21968 instantiate_decl do not try to instantiate it again. */
21969 DECL_TEMPLATE_INSTANTIATED (d) = 1;
21971 /* Regenerate the declaration in case the template has been modified
21972 by a subsequent redeclaration. */
21973 regenerate_decl_from_template (d, td, args);
21975 /* We already set the file and line above. Reset them now in case
21976 they changed as a result of calling regenerate_decl_from_template. */
21977 input_location = DECL_SOURCE_LOCATION (d);
21982 bool const_init = false;
21984 /* Clear out DECL_RTL; whatever was there before may not be right
21985 since we've reset the type of the declaration. */
21986 SET_DECL_RTL (d, NULL);
21987 DECL_IN_AGGR_P (d) = 0;
21989 /* The initializer is placed in DECL_INITIAL by
21990 regenerate_decl_from_template so we don't need to
21991 push/pop_access_scope again here. Pull it out so that
21992 cp_finish_decl can process it. */
21993 init = DECL_INITIAL (d);
21994 DECL_INITIAL (d) = NULL_TREE;
21995 DECL_INITIALIZED_P (d) = 0;
21997 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
21998 initializer. That function will defer actual emission until
21999 we have a chance to determine linkage. */
22000 DECL_EXTERNAL (d) = 0;
22002 /* Enter the scope of D so that access-checking works correctly. */
22003 bool enter_context = DECL_CLASS_SCOPE_P (d);
22005 push_nested_class (DECL_CONTEXT (d));
22007 const_init = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (code_pattern);
22008 cp_finish_decl (d, init, const_init, NULL_TREE, 0);
22011 pop_nested_class ();
22013 if (variable_template_p (gen_tmpl))
22014 note_variable_template_instantiation (d);
22016 else if (TREE_CODE (d) == FUNCTION_DECL && DECL_DEFAULTED_FN (code_pattern))
22017 synthesize_method (d);
22018 else if (TREE_CODE (d) == FUNCTION_DECL)
22020 hash_map<tree, tree> *saved_local_specializations;
22024 tree block = NULL_TREE;
22026 /* Save away the current list, in case we are instantiating one
22027 template from within the body of another. */
22028 saved_local_specializations = local_specializations;
22030 /* Set up the list of local specializations. */
22031 local_specializations = new hash_map<tree, tree>;
22033 /* Set up context. */
22034 if (DECL_OMP_DECLARE_REDUCTION_P (code_pattern)
22035 && TREE_CODE (DECL_CONTEXT (code_pattern)) == FUNCTION_DECL)
22036 block = push_stmt_list ();
22038 start_preparsed_function (d, NULL_TREE, SF_PRE_PARSED);
22040 /* Some typedefs referenced from within the template code need to be
22041 access checked at template instantiation time, i.e now. These
22042 types were added to the template at parsing time. Let's get those
22043 and perform the access checks then. */
22044 perform_typedefs_access_check (DECL_TEMPLATE_RESULT (gen_tmpl),
22047 /* Create substitution entries for the parameters. */
22048 subst_decl = DECL_TEMPLATE_RESULT (template_for_substitution (d));
22049 tmpl_parm = DECL_ARGUMENTS (subst_decl);
22050 spec_parm = DECL_ARGUMENTS (d);
22051 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (d))
22053 register_local_specialization (spec_parm, tmpl_parm);
22054 spec_parm = skip_artificial_parms_for (d, spec_parm);
22055 tmpl_parm = skip_artificial_parms_for (subst_decl, tmpl_parm);
22057 for (; tmpl_parm; tmpl_parm = DECL_CHAIN (tmpl_parm))
22059 if (!DECL_PACK_P (tmpl_parm))
22061 register_local_specialization (spec_parm, tmpl_parm);
22062 spec_parm = DECL_CHAIN (spec_parm);
22066 /* Register the (value) argument pack as a specialization of
22067 TMPL_PARM, then move on. */
22068 tree argpack = extract_fnparm_pack (tmpl_parm, &spec_parm);
22069 register_local_specialization (argpack, tmpl_parm);
22072 gcc_assert (!spec_parm);
22074 /* Substitute into the body of the function. */
22075 if (DECL_OMP_DECLARE_REDUCTION_P (code_pattern))
22076 tsubst_omp_udr (DECL_SAVED_TREE (code_pattern), args,
22077 tf_warning_or_error, tmpl);
22080 tsubst_expr (DECL_SAVED_TREE (code_pattern), args,
22081 tf_warning_or_error, tmpl,
22082 /*integral_constant_expression_p=*/false);
22084 /* Set the current input_location to the end of the function
22085 so that finish_function knows where we are. */
22087 = DECL_STRUCT_FUNCTION (code_pattern)->function_end_locus;
22089 /* Remember if we saw an infinite loop in the template. */
22090 current_function_infinite_loop
22091 = DECL_STRUCT_FUNCTION (code_pattern)->language->infinite_loop;
22094 /* We don't need the local specializations any more. */
22095 delete local_specializations;
22096 local_specializations = saved_local_specializations;
22098 /* Finish the function. */
22099 if (DECL_OMP_DECLARE_REDUCTION_P (code_pattern)
22100 && TREE_CODE (DECL_CONTEXT (code_pattern)) == FUNCTION_DECL)
22101 DECL_SAVED_TREE (d) = pop_stmt_list (block);
22104 d = finish_function (0);
22105 expand_or_defer_fn (d);
22108 if (DECL_OMP_DECLARE_REDUCTION_P (code_pattern))
22109 cp_check_omp_declare_reduction (d);
22112 /* We're not deferring instantiation any more. */
22113 TI_PENDING_TEMPLATE_FLAG (DECL_TEMPLATE_INFO (d)) = 0;
22116 pop_from_top_level ();
22118 pop_function_context ();
22121 input_location = saved_loc;
22122 cp_unevaluated_operand = saved_unevaluated_operand;
22123 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
22124 pop_deferring_access_checks ();
22125 pop_tinst_level ();
22127 restore_omp_privatization_clauses (omp_privatization_save);
22129 timevar_pop (TV_TEMPLATE_INST);
22134 /* Run through the list of templates that we wish we could
22135 instantiate, and instantiate any we can. RETRIES is the
22136 number of times we retry pending template instantiation. */
22139 instantiate_pending_templates (int retries)
22142 location_t saved_loc = input_location;
22144 /* Instantiating templates may trigger vtable generation. This in turn
22145 may require further template instantiations. We place a limit here
22146 to avoid infinite loop. */
22147 if (pending_templates && retries >= max_tinst_depth)
22149 tree decl = pending_templates->tinst->decl;
22151 fatal_error (input_location,
22152 "template instantiation depth exceeds maximum of %d"
22153 " instantiating %q+D, possibly from virtual table generation"
22154 " (use -ftemplate-depth= to increase the maximum)",
22155 max_tinst_depth, decl);
22156 if (TREE_CODE (decl) == FUNCTION_DECL)
22157 /* Pretend that we defined it. */
22158 DECL_INITIAL (decl) = error_mark_node;
22164 struct pending_template **t = &pending_templates;
22165 struct pending_template *last = NULL;
22169 tree instantiation = reopen_tinst_level ((*t)->tinst);
22170 bool complete = false;
22172 if (TYPE_P (instantiation))
22176 if (!COMPLETE_TYPE_P (instantiation))
22178 instantiate_class_template (instantiation);
22179 if (CLASSTYPE_TEMPLATE_INSTANTIATION (instantiation))
22180 for (fn = TYPE_METHODS (instantiation);
22182 fn = TREE_CHAIN (fn))
22183 if (! DECL_ARTIFICIAL (fn))
22184 instantiate_decl (fn,
22186 /*expl_inst_class_mem_p=*/false);
22187 if (COMPLETE_TYPE_P (instantiation))
22191 complete = COMPLETE_TYPE_P (instantiation);
22195 if (!DECL_TEMPLATE_SPECIALIZATION (instantiation)
22196 && !DECL_TEMPLATE_INSTANTIATED (instantiation))
22199 = instantiate_decl (instantiation,
22201 /*expl_inst_class_mem_p=*/false);
22202 if (DECL_TEMPLATE_INSTANTIATED (instantiation))
22206 complete = (DECL_TEMPLATE_SPECIALIZATION (instantiation)
22207 || DECL_TEMPLATE_INSTANTIATED (instantiation));
22211 /* If INSTANTIATION has been instantiated, then we don't
22212 need to consider it again in the future. */
22220 current_tinst_level = NULL;
22222 last_pending_template = last;
22224 while (reconsider);
22226 input_location = saved_loc;
22229 /* Substitute ARGVEC into T, which is a list of initializers for
22230 either base class or a non-static data member. The TREE_PURPOSEs
22231 are DECLs, and the TREE_VALUEs are the initializer values. Used by
22232 instantiate_decl. */
22235 tsubst_initializer_list (tree t, tree argvec)
22237 tree inits = NULL_TREE;
22239 for (; t; t = TREE_CHAIN (t))
22243 tree expanded_bases = NULL_TREE;
22244 tree expanded_arguments = NULL_TREE;
22247 if (TREE_CODE (TREE_PURPOSE (t)) == TYPE_PACK_EXPANSION)
22252 /* Expand the base class expansion type into separate base
22254 expanded_bases = tsubst_pack_expansion (TREE_PURPOSE (t), argvec,
22255 tf_warning_or_error,
22257 if (expanded_bases == error_mark_node)
22260 /* We'll be building separate TREE_LISTs of arguments for
22262 len = TREE_VEC_LENGTH (expanded_bases);
22263 expanded_arguments = make_tree_vec (len);
22264 for (i = 0; i < len; i++)
22265 TREE_VEC_ELT (expanded_arguments, i) = NULL_TREE;
22267 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
22268 expand each argument in the TREE_VALUE of t. */
22269 expr = make_node (EXPR_PACK_EXPANSION);
22270 PACK_EXPANSION_LOCAL_P (expr) = true;
22271 PACK_EXPANSION_PARAMETER_PACKS (expr) =
22272 PACK_EXPANSION_PARAMETER_PACKS (TREE_PURPOSE (t));
22274 if (TREE_VALUE (t) == void_type_node)
22275 /* VOID_TYPE_NODE is used to indicate
22276 value-initialization. */
22278 for (i = 0; i < len; i++)
22279 TREE_VEC_ELT (expanded_arguments, i) = void_type_node;
22283 /* Substitute parameter packs into each argument in the
22285 in_base_initializer = 1;
22286 for (arg = TREE_VALUE (t); arg; arg = TREE_CHAIN (arg))
22288 tree expanded_exprs;
22290 /* Expand the argument. */
22291 SET_PACK_EXPANSION_PATTERN (expr, TREE_VALUE (arg));
22293 = tsubst_pack_expansion (expr, argvec,
22294 tf_warning_or_error,
22296 if (expanded_exprs == error_mark_node)
22299 /* Prepend each of the expanded expressions to the
22300 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
22301 for (i = 0; i < len; i++)
22303 TREE_VEC_ELT (expanded_arguments, i) =
22304 tree_cons (NULL_TREE,
22305 TREE_VEC_ELT (expanded_exprs, i),
22306 TREE_VEC_ELT (expanded_arguments, i));
22309 in_base_initializer = 0;
22311 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
22312 since we built them backwards. */
22313 for (i = 0; i < len; i++)
22315 TREE_VEC_ELT (expanded_arguments, i) =
22316 nreverse (TREE_VEC_ELT (expanded_arguments, i));
22321 for (i = 0; i < len; ++i)
22323 if (expanded_bases)
22325 decl = TREE_VEC_ELT (expanded_bases, i);
22326 decl = expand_member_init (decl);
22327 init = TREE_VEC_ELT (expanded_arguments, i);
22332 decl = tsubst_copy (TREE_PURPOSE (t), argvec,
22333 tf_warning_or_error, NULL_TREE);
22335 decl = expand_member_init (decl);
22336 if (decl && !DECL_P (decl))
22337 in_base_initializer = 1;
22339 init = TREE_VALUE (t);
22341 if (init != void_type_node)
22342 init = tsubst_expr (init, argvec,
22343 tf_warning_or_error, NULL_TREE,
22344 /*integral_constant_expression_p=*/false);
22345 if (init == NULL_TREE && tmp != NULL_TREE)
22346 /* If we had an initializer but it instantiated to nothing,
22347 value-initialize the object. This will only occur when
22348 the initializer was a pack expansion where the parameter
22349 packs used in that expansion were of length zero. */
22350 init = void_type_node;
22351 in_base_initializer = 0;
22356 init = build_tree_list (decl, init);
22357 TREE_CHAIN (init) = inits;
22365 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
22368 set_current_access_from_decl (tree decl)
22370 if (TREE_PRIVATE (decl))
22371 current_access_specifier = access_private_node;
22372 else if (TREE_PROTECTED (decl))
22373 current_access_specifier = access_protected_node;
22375 current_access_specifier = access_public_node;
22378 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
22379 is the instantiation (which should have been created with
22380 start_enum) and ARGS are the template arguments to use. */
22383 tsubst_enum (tree tag, tree newtag, tree args)
22387 if (SCOPED_ENUM_P (newtag))
22388 begin_scope (sk_scoped_enum, newtag);
22390 for (e = TYPE_VALUES (tag); e; e = TREE_CHAIN (e))
22395 decl = TREE_VALUE (e);
22396 /* Note that in a template enum, the TREE_VALUE is the
22397 CONST_DECL, not the corresponding INTEGER_CST. */
22398 value = tsubst_expr (DECL_INITIAL (decl),
22399 args, tf_warning_or_error, NULL_TREE,
22400 /*integral_constant_expression_p=*/true);
22402 /* Give this enumeration constant the correct access. */
22403 set_current_access_from_decl (decl);
22405 /* Actually build the enumerator itself. Here we're assuming that
22406 enumerators can't have dependent attributes. */
22407 build_enumerator (DECL_NAME (decl), value, newtag,
22408 DECL_ATTRIBUTES (decl), DECL_SOURCE_LOCATION (decl));
22411 if (SCOPED_ENUM_P (newtag))
22414 finish_enum_value_list (newtag);
22415 finish_enum (newtag);
22417 DECL_SOURCE_LOCATION (TYPE_NAME (newtag))
22418 = DECL_SOURCE_LOCATION (TYPE_NAME (tag));
22421 /* DECL is a FUNCTION_DECL that is a template specialization. Return
22422 its type -- but without substituting the innermost set of template
22423 arguments. So, innermost set of template parameters will appear in
22427 get_mostly_instantiated_function_type (tree decl)
22429 /* For a function, DECL_TI_TEMPLATE is partially instantiated. */
22430 return TREE_TYPE (DECL_TI_TEMPLATE (decl));
22433 /* Return truthvalue if we're processing a template different from
22434 the last one involved in diagnostics. */
22436 problematic_instantiation_changed (void)
22438 return current_tinst_level != last_error_tinst_level;
22441 /* Remember current template involved in diagnostics. */
22443 record_last_problematic_instantiation (void)
22445 last_error_tinst_level = current_tinst_level;
22448 struct tinst_level *
22449 current_instantiation (void)
22451 return current_tinst_level;
22454 /* Return TRUE if current_function_decl is being instantiated, false
22458 instantiating_current_function_p (void)
22460 return (current_instantiation ()
22461 && current_instantiation ()->decl == current_function_decl);
22464 /* [temp.param] Check that template non-type parm TYPE is of an allowable
22465 type. Return zero for ok, nonzero for disallowed. Issue error and
22466 warning messages under control of COMPLAIN. */
22469 invalid_nontype_parm_type_p (tree type, tsubst_flags_t complain)
22471 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
22473 else if (POINTER_TYPE_P (type))
22475 else if (TYPE_PTRMEM_P (type))
22477 else if (TREE_CODE (type) == TEMPLATE_TYPE_PARM)
22479 else if (TREE_CODE (type) == TYPENAME_TYPE)
22481 else if (TREE_CODE (type) == DECLTYPE_TYPE)
22483 else if (TREE_CODE (type) == NULLPTR_TYPE)
22485 /* A bound template template parm could later be instantiated to have a valid
22486 nontype parm type via an alias template. */
22487 else if (cxx_dialect >= cxx11
22488 && TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
22491 if (complain & tf_error)
22493 if (type == error_mark_node)
22494 inform (input_location, "invalid template non-type parameter");
22496 error ("%q#T is not a valid type for a template non-type parameter",
22502 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
22503 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
22506 dependent_type_p_r (tree type)
22512 A type is dependent if it is:
22514 -- a template parameter. Template template parameters are types
22515 for us (since TYPE_P holds true for them) so we handle
22517 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
22518 || TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM)
22520 /* -- a qualified-id with a nested-name-specifier which contains a
22521 class-name that names a dependent type or whose unqualified-id
22522 names a dependent type. */
22523 if (TREE_CODE (type) == TYPENAME_TYPE)
22526 /* An alias template specialization can be dependent even if the
22527 resulting type is not. */
22528 if (dependent_alias_template_spec_p (type))
22531 /* -- a cv-qualified type where the cv-unqualified type is
22533 No code is necessary for this bullet; the code below handles
22534 cv-qualified types, and we don't want to strip aliases with
22535 TYPE_MAIN_VARIANT because of DR 1558. */
22536 /* -- a compound type constructed from any dependent type. */
22537 if (TYPE_PTRMEM_P (type))
22538 return (dependent_type_p (TYPE_PTRMEM_CLASS_TYPE (type))
22539 || dependent_type_p (TYPE_PTRMEM_POINTED_TO_TYPE
22541 else if (TYPE_PTR_P (type)
22542 || TREE_CODE (type) == REFERENCE_TYPE)
22543 return dependent_type_p (TREE_TYPE (type));
22544 else if (TREE_CODE (type) == FUNCTION_TYPE
22545 || TREE_CODE (type) == METHOD_TYPE)
22549 if (dependent_type_p (TREE_TYPE (type)))
22551 for (arg_type = TYPE_ARG_TYPES (type);
22553 arg_type = TREE_CHAIN (arg_type))
22554 if (dependent_type_p (TREE_VALUE (arg_type)))
22558 /* -- an array type constructed from any dependent type or whose
22559 size is specified by a constant expression that is
22562 We checked for type- and value-dependence of the bounds in
22563 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
22564 if (TREE_CODE (type) == ARRAY_TYPE)
22566 if (TYPE_DOMAIN (type)
22567 && dependent_type_p (TYPE_DOMAIN (type)))
22569 return dependent_type_p (TREE_TYPE (type));
22572 /* -- a template-id in which either the template name is a template
22574 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
22576 /* ... or any of the template arguments is a dependent type or
22577 an expression that is type-dependent or value-dependent. */
22578 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INFO (type)
22579 && (any_dependent_template_arguments_p
22580 (INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type)))))
22583 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
22584 dependent; if the argument of the `typeof' expression is not
22585 type-dependent, then it should already been have resolved. */
22586 if (TREE_CODE (type) == TYPEOF_TYPE
22587 || TREE_CODE (type) == DECLTYPE_TYPE
22588 || TREE_CODE (type) == UNDERLYING_TYPE)
22591 /* A template argument pack is dependent if any of its packed
22593 if (TREE_CODE (type) == TYPE_ARGUMENT_PACK)
22595 tree args = ARGUMENT_PACK_ARGS (type);
22596 int i, len = TREE_VEC_LENGTH (args);
22597 for (i = 0; i < len; ++i)
22598 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
22602 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
22603 be template parameters. */
22604 if (TREE_CODE (type) == TYPE_PACK_EXPANSION)
22607 /* The standard does not specifically mention types that are local
22608 to template functions or local classes, but they should be
22609 considered dependent too. For example:
22611 template <int I> void f() {
22616 The size of `E' cannot be known until the value of `I' has been
22617 determined. Therefore, `E' must be considered dependent. */
22618 scope = TYPE_CONTEXT (type);
22619 if (scope && TYPE_P (scope))
22620 return dependent_type_p (scope);
22621 /* Don't use type_dependent_expression_p here, as it can lead
22622 to infinite recursion trying to determine whether a lambda
22623 nested in a lambda is dependent (c++/47687). */
22624 else if (scope && TREE_CODE (scope) == FUNCTION_DECL
22625 && DECL_LANG_SPECIFIC (scope)
22626 && DECL_TEMPLATE_INFO (scope)
22627 && (any_dependent_template_arguments_p
22628 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (scope)))))
22631 /* Other types are non-dependent. */
22635 /* Returns TRUE if TYPE is dependent, in the sense of
22636 [temp.dep.type]. Note that a NULL type is considered dependent. */
22639 dependent_type_p (tree type)
22641 /* If there are no template parameters in scope, then there can't be
22642 any dependent types. */
22643 if (!processing_template_decl)
22645 /* If we are not processing a template, then nobody should be
22646 providing us with a dependent type. */
22648 gcc_assert (TREE_CODE (type) != TEMPLATE_TYPE_PARM || is_auto (type));
22652 /* If the type is NULL, we have not computed a type for the entity
22653 in question; in that case, the type is dependent. */
22657 /* Erroneous types can be considered non-dependent. */
22658 if (type == error_mark_node)
22661 /* If we have not already computed the appropriate value for TYPE,
22663 if (!TYPE_DEPENDENT_P_VALID (type))
22665 TYPE_DEPENDENT_P (type) = dependent_type_p_r (type);
22666 TYPE_DEPENDENT_P_VALID (type) = 1;
22669 return TYPE_DEPENDENT_P (type);
22672 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
22673 lookup. In other words, a dependent type that is not the current
22677 dependent_scope_p (tree scope)
22679 return (scope && TYPE_P (scope) && dependent_type_p (scope)
22680 && !currently_open_class (scope));
22683 /* T is a SCOPE_REF; return whether we need to consider it
22684 instantiation-dependent so that we can check access at instantiation
22685 time even though we know which member it resolves to. */
22688 instantiation_dependent_scope_ref_p (tree t)
22690 if (DECL_P (TREE_OPERAND (t, 1))
22691 && CLASS_TYPE_P (TREE_OPERAND (t, 0))
22692 && accessible_in_template_p (TREE_OPERAND (t, 0),
22693 TREE_OPERAND (t, 1)))
22699 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
22700 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
22703 /* Note that this predicate is not appropriate for general expressions;
22704 only constant expressions (that satisfy potential_constant_expression)
22705 can be tested for value dependence. */
22708 value_dependent_expression_p (tree expression)
22710 if (!processing_template_decl)
22713 /* A name declared with a dependent type. */
22714 if (DECL_P (expression) && type_dependent_expression_p (expression))
22717 switch (TREE_CODE (expression))
22719 case IDENTIFIER_NODE:
22720 /* A name that has not been looked up -- must be dependent. */
22723 case TEMPLATE_PARM_INDEX:
22724 /* A non-type template parm. */
22728 /* A non-type template parm. */
22729 if (DECL_TEMPLATE_PARM_P (expression))
22731 return value_dependent_expression_p (DECL_INITIAL (expression));
22734 /* A constant with literal type and is initialized
22735 with an expression that is value-dependent.
22737 Note that a non-dependent parenthesized initializer will have
22738 already been replaced with its constant value, so if we see
22739 a TREE_LIST it must be dependent. */
22740 if (DECL_INITIAL (expression)
22741 && decl_constant_var_p (expression)
22742 && (TREE_CODE (DECL_INITIAL (expression)) == TREE_LIST
22743 /* cp_finish_decl doesn't fold reference initializers. */
22744 || TREE_CODE (TREE_TYPE (expression)) == REFERENCE_TYPE
22745 || type_dependent_expression_p (DECL_INITIAL (expression))
22746 || value_dependent_expression_p (DECL_INITIAL (expression))))
22750 case DYNAMIC_CAST_EXPR:
22751 case STATIC_CAST_EXPR:
22752 case CONST_CAST_EXPR:
22753 case REINTERPRET_CAST_EXPR:
22755 /* These expressions are value-dependent if the type to which
22756 the cast occurs is dependent or the expression being casted
22757 is value-dependent. */
22759 tree type = TREE_TYPE (expression);
22761 if (dependent_type_p (type))
22764 /* A functional cast has a list of operands. */
22765 expression = TREE_OPERAND (expression, 0);
22768 /* If there are no operands, it must be an expression such
22769 as "int()". This should not happen for aggregate types
22770 because it would form non-constant expressions. */
22771 gcc_assert (cxx_dialect >= cxx11
22772 || INTEGRAL_OR_ENUMERATION_TYPE_P (type));
22777 if (TREE_CODE (expression) == TREE_LIST)
22778 return any_value_dependent_elements_p (expression);
22780 return value_dependent_expression_p (expression);
22784 if (SIZEOF_EXPR_TYPE_P (expression))
22785 return dependent_type_p (TREE_TYPE (TREE_OPERAND (expression, 0)));
22789 /* A `sizeof' expression is value-dependent if the operand is
22790 type-dependent or is a pack expansion. */
22791 expression = TREE_OPERAND (expression, 0);
22792 if (PACK_EXPANSION_P (expression))
22794 else if (TYPE_P (expression))
22795 return dependent_type_p (expression);
22796 return instantiation_dependent_uneval_expression_p (expression);
22798 case AT_ENCODE_EXPR:
22799 /* An 'encode' expression is value-dependent if the operand is
22801 expression = TREE_OPERAND (expression, 0);
22802 return dependent_type_p (expression);
22804 case NOEXCEPT_EXPR:
22805 expression = TREE_OPERAND (expression, 0);
22806 return instantiation_dependent_uneval_expression_p (expression);
22809 /* All instantiation-dependent expressions should also be considered
22810 value-dependent. */
22811 return instantiation_dependent_scope_ref_p (expression);
22813 case COMPONENT_REF:
22814 return (value_dependent_expression_p (TREE_OPERAND (expression, 0))
22815 || value_dependent_expression_p (TREE_OPERAND (expression, 1)));
22817 case NONTYPE_ARGUMENT_PACK:
22818 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
22819 is value-dependent. */
22821 tree values = ARGUMENT_PACK_ARGS (expression);
22822 int i, len = TREE_VEC_LENGTH (values);
22824 for (i = 0; i < len; ++i)
22825 if (value_dependent_expression_p (TREE_VEC_ELT (values, i)))
22833 tree type2 = TRAIT_EXPR_TYPE2 (expression);
22834 return (dependent_type_p (TRAIT_EXPR_TYPE1 (expression))
22835 || (type2 ? dependent_type_p (type2) : false));
22839 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
22840 || (value_dependent_expression_p (TREE_OPERAND (expression, 2))));
22843 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
22844 || (value_dependent_expression_p (TREE_OPERAND (expression, 1))));
22848 tree op = TREE_OPERAND (expression, 0);
22849 return (value_dependent_expression_p (op)
22850 || has_value_dependent_address (op));
22853 case REQUIRES_EXPR:
22854 /* Treat all requires-expressions as value-dependent so
22855 we don't try to fold them. */
22859 return dependent_type_p (TREE_OPERAND (expression, 0));
22863 if (!CALL_EXPR_FN (expression))
22865 tree fn = get_callee_fndecl (expression);
22867 if (!fn && value_dependent_expression_p (CALL_EXPR_FN (expression)))
22869 nargs = call_expr_nargs (expression);
22870 for (i = 0; i < nargs; ++i)
22872 tree op = CALL_EXPR_ARG (expression, i);
22873 /* In a call to a constexpr member function, look through the
22874 implicit ADDR_EXPR on the object argument so that it doesn't
22875 cause the call to be considered value-dependent. We also
22876 look through it in potential_constant_expression. */
22877 if (i == 0 && fn && DECL_DECLARED_CONSTEXPR_P (fn)
22878 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
22879 && TREE_CODE (op) == ADDR_EXPR)
22880 op = TREE_OPERAND (op, 0);
22881 if (value_dependent_expression_p (op))
22887 case TEMPLATE_ID_EXPR:
22888 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
22890 return type_dependent_expression_p (expression)
22891 || variable_concept_p (TREE_OPERAND (expression, 0));
22897 if (dependent_type_p (TREE_TYPE (expression)))
22899 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), ix, val)
22900 if (value_dependent_expression_p (val))
22906 /* Treat a GNU statement expression as dependent to avoid crashing
22907 under instantiate_non_dependent_expr; it can't be constant. */
22911 /* A constant expression is value-dependent if any subexpression is
22912 value-dependent. */
22913 switch (TREE_CODE_CLASS (TREE_CODE (expression)))
22915 case tcc_reference:
22917 case tcc_comparison:
22919 case tcc_expression:
22922 int i, len = cp_tree_operand_length (expression);
22924 for (i = 0; i < len; i++)
22926 tree t = TREE_OPERAND (expression, i);
22928 /* In some cases, some of the operands may be missing.l
22929 (For example, in the case of PREDECREMENT_EXPR, the
22930 amount to increment by may be missing.) That doesn't
22931 make the expression dependent. */
22932 if (t && value_dependent_expression_p (t))
22943 /* The expression is not value-dependent. */
22947 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
22948 [temp.dep.expr]. Note that an expression with no type is
22949 considered dependent. Other parts of the compiler arrange for an
22950 expression with type-dependent subexpressions to have no type, so
22951 this function doesn't have to be fully recursive. */
22954 type_dependent_expression_p (tree expression)
22956 if (!processing_template_decl)
22959 if (expression == NULL_TREE || expression == error_mark_node)
22962 /* An unresolved name is always dependent. */
22963 if (identifier_p (expression)
22964 || TREE_CODE (expression) == USING_DECL
22965 || TREE_CODE (expression) == WILDCARD_DECL)
22968 /* A fold expression is type-dependent. */
22969 if (TREE_CODE (expression) == UNARY_LEFT_FOLD_EXPR
22970 || TREE_CODE (expression) == UNARY_RIGHT_FOLD_EXPR
22971 || TREE_CODE (expression) == BINARY_LEFT_FOLD_EXPR
22972 || TREE_CODE (expression) == BINARY_RIGHT_FOLD_EXPR)
22975 /* Some expression forms are never type-dependent. */
22976 if (TREE_CODE (expression) == PSEUDO_DTOR_EXPR
22977 || TREE_CODE (expression) == SIZEOF_EXPR
22978 || TREE_CODE (expression) == ALIGNOF_EXPR
22979 || TREE_CODE (expression) == AT_ENCODE_EXPR
22980 || TREE_CODE (expression) == NOEXCEPT_EXPR
22981 || TREE_CODE (expression) == TRAIT_EXPR
22982 || TREE_CODE (expression) == TYPEID_EXPR
22983 || TREE_CODE (expression) == DELETE_EXPR
22984 || TREE_CODE (expression) == VEC_DELETE_EXPR
22985 || TREE_CODE (expression) == THROW_EXPR
22986 || TREE_CODE (expression) == REQUIRES_EXPR)
22989 /* The types of these expressions depends only on the type to which
22990 the cast occurs. */
22991 if (TREE_CODE (expression) == DYNAMIC_CAST_EXPR
22992 || TREE_CODE (expression) == STATIC_CAST_EXPR
22993 || TREE_CODE (expression) == CONST_CAST_EXPR
22994 || TREE_CODE (expression) == REINTERPRET_CAST_EXPR
22995 || TREE_CODE (expression) == IMPLICIT_CONV_EXPR
22996 || TREE_CODE (expression) == CAST_EXPR)
22997 return dependent_type_p (TREE_TYPE (expression));
22999 /* The types of these expressions depends only on the type created
23000 by the expression. */
23001 if (TREE_CODE (expression) == NEW_EXPR
23002 || TREE_CODE (expression) == VEC_NEW_EXPR)
23004 /* For NEW_EXPR tree nodes created inside a template, either
23005 the object type itself or a TREE_LIST may appear as the
23007 tree type = TREE_OPERAND (expression, 1);
23008 if (TREE_CODE (type) == TREE_LIST)
23009 /* This is an array type. We need to check array dimensions
23011 return dependent_type_p (TREE_VALUE (TREE_PURPOSE (type)))
23012 || value_dependent_expression_p
23013 (TREE_OPERAND (TREE_VALUE (type), 1));
23015 return dependent_type_p (type);
23018 if (TREE_CODE (expression) == SCOPE_REF)
23020 tree scope = TREE_OPERAND (expression, 0);
23021 tree name = TREE_OPERAND (expression, 1);
23023 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
23024 contains an identifier associated by name lookup with one or more
23025 declarations declared with a dependent type, or...a
23026 nested-name-specifier or qualified-id that names a member of an
23027 unknown specialization. */
23028 return (type_dependent_expression_p (name)
23029 || dependent_scope_p (scope));
23032 /* A function template specialization is type-dependent if it has any
23033 dependent template arguments. */
23034 if (TREE_CODE (expression) == FUNCTION_DECL
23035 && DECL_LANG_SPECIFIC (expression)
23036 && DECL_TEMPLATE_INFO (expression))
23037 return any_dependent_template_arguments_p (DECL_TI_ARGS (expression));
23039 if (TREE_CODE (expression) == TEMPLATE_DECL
23040 && !DECL_TEMPLATE_TEMPLATE_PARM_P (expression))
23043 if (TREE_CODE (expression) == STMT_EXPR)
23044 expression = stmt_expr_value_expr (expression);
23046 if (BRACE_ENCLOSED_INITIALIZER_P (expression))
23051 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), i, elt)
23053 if (type_dependent_expression_p (elt))
23059 /* A static data member of the current instantiation with incomplete
23060 array type is type-dependent, as the definition and specializations
23061 can have different bounds. */
23062 if (VAR_P (expression)
23063 && DECL_CLASS_SCOPE_P (expression)
23064 && dependent_type_p (DECL_CONTEXT (expression))
23065 && VAR_HAD_UNKNOWN_BOUND (expression))
23068 /* An array of unknown bound depending on a variadic parameter, eg:
23070 template<typename... Args>
23071 void foo (Args... args)
23073 int arr[] = { args... };
23076 template<int... vals>
23079 int arr[] = { vals... };
23082 If the array has no length and has an initializer, it must be that
23083 we couldn't determine its length in cp_complete_array_type because
23084 it is dependent. */
23085 if (VAR_P (expression)
23086 && TREE_CODE (TREE_TYPE (expression)) == ARRAY_TYPE
23087 && !TYPE_DOMAIN (TREE_TYPE (expression))
23088 && DECL_INITIAL (expression))
23091 /* A variable template specialization is type-dependent if it has any
23092 dependent template arguments. */
23093 if (VAR_P (expression)
23094 && DECL_LANG_SPECIFIC (expression)
23095 && DECL_TEMPLATE_INFO (expression)
23096 && variable_template_p (DECL_TI_TEMPLATE (expression)))
23097 return any_dependent_template_arguments_p (DECL_TI_ARGS (expression));
23099 /* Always dependent, on the number of arguments if nothing else. */
23100 if (TREE_CODE (expression) == EXPR_PACK_EXPANSION)
23103 if (TREE_TYPE (expression) == unknown_type_node)
23105 if (TREE_CODE (expression) == ADDR_EXPR)
23106 return type_dependent_expression_p (TREE_OPERAND (expression, 0));
23107 if (TREE_CODE (expression) == COMPONENT_REF
23108 || TREE_CODE (expression) == OFFSET_REF)
23110 if (type_dependent_expression_p (TREE_OPERAND (expression, 0)))
23112 expression = TREE_OPERAND (expression, 1);
23113 if (identifier_p (expression))
23116 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
23117 if (TREE_CODE (expression) == SCOPE_REF)
23120 if (BASELINK_P (expression))
23122 if (BASELINK_OPTYPE (expression)
23123 && dependent_type_p (BASELINK_OPTYPE (expression)))
23125 expression = BASELINK_FUNCTIONS (expression);
23128 if (TREE_CODE (expression) == TEMPLATE_ID_EXPR)
23130 if (any_dependent_template_arguments_p
23131 (TREE_OPERAND (expression, 1)))
23133 expression = TREE_OPERAND (expression, 0);
23134 if (identifier_p (expression))
23138 gcc_assert (TREE_CODE (expression) == OVERLOAD
23139 || TREE_CODE (expression) == FUNCTION_DECL);
23143 if (type_dependent_expression_p (OVL_CURRENT (expression)))
23145 expression = OVL_NEXT (expression);
23150 gcc_assert (TREE_CODE (expression) != TYPE_DECL);
23152 return (dependent_type_p (TREE_TYPE (expression)));
23155 /* walk_tree callback function for instantiation_dependent_expression_p,
23156 below. Returns non-zero if a dependent subexpression is found. */
23159 instantiation_dependent_r (tree *tp, int *walk_subtrees,
23164 /* We don't have to worry about decltype currently because decltype
23165 of an instantiation-dependent expr is a dependent type. This
23166 might change depending on the resolution of DR 1172. */
23167 *walk_subtrees = false;
23170 enum tree_code code = TREE_CODE (*tp);
23173 /* Don't treat an argument list as dependent just because it has no
23179 case TEMPLATE_PARM_INDEX:
23182 /* Handle expressions with type operands. */
23186 case AT_ENCODE_EXPR:
23188 tree op = TREE_OPERAND (*tp, 0);
23189 if (code == SIZEOF_EXPR && SIZEOF_EXPR_TYPE_P (*tp))
23190 op = TREE_TYPE (op);
23193 if (dependent_type_p (op))
23197 *walk_subtrees = false;
23204 case COMPONENT_REF:
23205 if (identifier_p (TREE_OPERAND (*tp, 1)))
23206 /* In a template, finish_class_member_access_expr creates a
23207 COMPONENT_REF with an IDENTIFIER_NODE for op1 even if it isn't
23208 type-dependent, so that we can check access control at
23209 instantiation time (PR 42277). See also Core issue 1273. */
23214 if (instantiation_dependent_scope_ref_p (*tp))
23219 /* Treat statement-expressions as dependent. */
23223 /* Treat requires-expressions as dependent. */
23224 case REQUIRES_EXPR:
23228 /* Treat calls to function concepts as dependent. */
23229 if (CALL_EXPR_FN (*tp) && function_concept_check_p (*tp))
23233 case TEMPLATE_ID_EXPR:
23234 /* And variable concepts. */
23235 if (variable_concept_p (TREE_OPERAND (*tp, 0)))
23243 if (type_dependent_expression_p (*tp))
23249 /* Returns TRUE if the EXPRESSION is instantiation-dependent, in the
23250 sense defined by the ABI:
23252 "An expression is instantiation-dependent if it is type-dependent
23253 or value-dependent, or it has a subexpression that is type-dependent
23254 or value-dependent."
23256 Except don't actually check value-dependence for unevaluated expressions,
23257 because in sizeof(i) we don't care about the value of i. Checking
23258 type-dependence will in turn check value-dependence of array bounds/template
23259 arguments as needed. */
23262 instantiation_dependent_uneval_expression_p (tree expression)
23266 if (!processing_template_decl)
23269 if (expression == error_mark_node)
23272 result = cp_walk_tree_without_duplicates (&expression,
23273 instantiation_dependent_r, NULL);
23274 return result != NULL_TREE;
23277 /* As above, but also check value-dependence of the expression as a whole. */
23280 instantiation_dependent_expression_p (tree expression)
23282 return (instantiation_dependent_uneval_expression_p (expression)
23283 || value_dependent_expression_p (expression));
23286 /* Like type_dependent_expression_p, but it also works while not processing
23287 a template definition, i.e. during substitution or mangling. */
23290 type_dependent_expression_p_push (tree expr)
23293 ++processing_template_decl;
23294 b = type_dependent_expression_p (expr);
23295 --processing_template_decl;
23299 /* Returns TRUE if ARGS contains a type-dependent expression. */
23302 any_type_dependent_arguments_p (const vec<tree, va_gc> *args)
23307 FOR_EACH_VEC_SAFE_ELT (args, i, arg)
23309 if (type_dependent_expression_p (arg))
23315 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
23316 expressions) contains any type-dependent expressions. */
23319 any_type_dependent_elements_p (const_tree list)
23321 for (; list; list = TREE_CHAIN (list))
23322 if (type_dependent_expression_p (TREE_VALUE (list)))
23328 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
23329 expressions) contains any value-dependent expressions. */
23332 any_value_dependent_elements_p (const_tree list)
23334 for (; list; list = TREE_CHAIN (list))
23335 if (value_dependent_expression_p (TREE_VALUE (list)))
23341 /* Returns TRUE if the ARG (a template argument) is dependent. */
23344 dependent_template_arg_p (tree arg)
23346 if (!processing_template_decl)
23349 /* Assume a template argument that was wrongly written by the user
23350 is dependent. This is consistent with what
23351 any_dependent_template_arguments_p [that calls this function]
23353 if (!arg || arg == error_mark_node)
23356 if (TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
23357 arg = ARGUMENT_PACK_SELECT_ARG (arg);
23359 if (TREE_CODE (arg) == TEMPLATE_DECL
23360 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
23361 return dependent_template_p (arg);
23362 else if (ARGUMENT_PACK_P (arg))
23364 tree args = ARGUMENT_PACK_ARGS (arg);
23365 int i, len = TREE_VEC_LENGTH (args);
23366 for (i = 0; i < len; ++i)
23368 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
23374 else if (TYPE_P (arg))
23375 return dependent_type_p (arg);
23377 return (type_dependent_expression_p (arg)
23378 || value_dependent_expression_p (arg));
23381 /* Returns true if ARGS (a collection of template arguments) contains
23382 any types that require structural equality testing. */
23385 any_template_arguments_need_structural_equality_p (tree args)
23392 if (args == error_mark_node)
23395 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
23397 tree level = TMPL_ARGS_LEVEL (args, i + 1);
23398 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
23400 tree arg = TREE_VEC_ELT (level, j);
23401 tree packed_args = NULL_TREE;
23404 if (ARGUMENT_PACK_P (arg))
23406 /* Look inside the argument pack. */
23407 packed_args = ARGUMENT_PACK_ARGS (arg);
23408 len = TREE_VEC_LENGTH (packed_args);
23411 for (k = 0; k < len; ++k)
23414 arg = TREE_VEC_ELT (packed_args, k);
23416 if (error_operand_p (arg))
23418 else if (TREE_CODE (arg) == TEMPLATE_DECL)
23420 else if (TYPE_P (arg) && TYPE_STRUCTURAL_EQUALITY_P (arg))
23422 else if (!TYPE_P (arg) && TREE_TYPE (arg)
23423 && TYPE_STRUCTURAL_EQUALITY_P (TREE_TYPE (arg)))
23432 /* Returns true if ARGS (a collection of template arguments) contains
23433 any dependent arguments. */
23436 any_dependent_template_arguments_p (const_tree args)
23443 if (args == error_mark_node)
23446 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
23448 const_tree level = TMPL_ARGS_LEVEL (args, i + 1);
23449 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
23450 if (dependent_template_arg_p (TREE_VEC_ELT (level, j)))
23457 /* Returns TRUE if the template TMPL is dependent. */
23460 dependent_template_p (tree tmpl)
23462 if (TREE_CODE (tmpl) == OVERLOAD)
23466 if (dependent_template_p (OVL_CURRENT (tmpl)))
23468 tmpl = OVL_NEXT (tmpl);
23473 /* Template template parameters are dependent. */
23474 if (DECL_TEMPLATE_TEMPLATE_PARM_P (tmpl)
23475 || TREE_CODE (tmpl) == TEMPLATE_TEMPLATE_PARM)
23477 /* So are names that have not been looked up. */
23478 if (TREE_CODE (tmpl) == SCOPE_REF || identifier_p (tmpl))
23480 /* So are member templates of dependent classes. */
23481 if (TYPE_P (CP_DECL_CONTEXT (tmpl)))
23482 return dependent_type_p (DECL_CONTEXT (tmpl));
23486 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
23489 dependent_template_id_p (tree tmpl, tree args)
23491 return (dependent_template_p (tmpl)
23492 || any_dependent_template_arguments_p (args));
23495 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
23499 dependent_omp_for_p (tree declv, tree initv, tree condv, tree incrv)
23503 if (!processing_template_decl)
23506 for (i = 0; i < TREE_VEC_LENGTH (declv); i++)
23508 tree decl = TREE_VEC_ELT (declv, i);
23509 tree init = TREE_VEC_ELT (initv, i);
23510 tree cond = TREE_VEC_ELT (condv, i);
23511 tree incr = TREE_VEC_ELT (incrv, i);
23513 if (type_dependent_expression_p (decl)
23514 || TREE_CODE (decl) == SCOPE_REF)
23517 if (init && type_dependent_expression_p (init))
23520 if (type_dependent_expression_p (cond))
23523 if (COMPARISON_CLASS_P (cond)
23524 && (type_dependent_expression_p (TREE_OPERAND (cond, 0))
23525 || type_dependent_expression_p (TREE_OPERAND (cond, 1))))
23528 if (TREE_CODE (incr) == MODOP_EXPR)
23530 if (type_dependent_expression_p (TREE_OPERAND (incr, 0))
23531 || type_dependent_expression_p (TREE_OPERAND (incr, 2)))
23534 else if (type_dependent_expression_p (incr))
23536 else if (TREE_CODE (incr) == MODIFY_EXPR)
23538 if (type_dependent_expression_p (TREE_OPERAND (incr, 0)))
23540 else if (BINARY_CLASS_P (TREE_OPERAND (incr, 1)))
23542 tree t = TREE_OPERAND (incr, 1);
23543 if (type_dependent_expression_p (TREE_OPERAND (t, 0))
23544 || type_dependent_expression_p (TREE_OPERAND (t, 1)))
23553 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
23554 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
23555 no such TYPE can be found. Note that this function peers inside
23556 uninstantiated templates and therefore should be used only in
23557 extremely limited situations. ONLY_CURRENT_P restricts this
23558 peering to the currently open classes hierarchy (which is required
23559 when comparing types). */
23562 resolve_typename_type (tree type, bool only_current_p)
23571 gcc_assert (TREE_CODE (type) == TYPENAME_TYPE);
23573 scope = TYPE_CONTEXT (type);
23574 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
23575 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
23576 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
23577 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
23578 identifier of the TYPENAME_TYPE anymore.
23579 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
23580 TYPENAME_TYPE instead, we avoid messing up with a possible
23581 typedef variant case. */
23582 name = TYPE_IDENTIFIER (TYPE_MAIN_VARIANT (type));
23584 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
23585 it first before we can figure out what NAME refers to. */
23586 if (TREE_CODE (scope) == TYPENAME_TYPE)
23588 if (TYPENAME_IS_RESOLVING_P (scope))
23589 /* Given a class template A with a dependent base with nested type C,
23590 typedef typename A::C::C C will land us here, as trying to resolve
23591 the initial A::C leads to the local C typedef, which leads back to
23592 A::C::C. So we break the recursion now. */
23595 scope = resolve_typename_type (scope, only_current_p);
23597 /* If we don't know what SCOPE refers to, then we cannot resolve the
23599 if (!CLASS_TYPE_P (scope))
23601 /* If this is a typedef, we don't want to look inside (c++/11987). */
23602 if (typedef_variant_p (type))
23604 /* If SCOPE isn't the template itself, it will not have a valid
23605 TYPE_FIELDS list. */
23606 if (same_type_p (scope, CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope)))
23607 /* scope is either the template itself or a compatible instantiation
23608 like X<T>, so look up the name in the original template. */
23609 scope = CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope);
23610 /* We shouldn't have built a TYPENAME_TYPE with a non-dependent scope. */
23611 gcc_checking_assert (uses_template_parms (scope));
23612 /* If scope has no fields, it can't be a current instantiation. Check this
23613 before currently_open_class to avoid infinite recursion (71515). */
23614 if (!TYPE_FIELDS (scope))
23616 /* If the SCOPE is not the current instantiation, there's no reason
23617 to look inside it. */
23618 if (only_current_p && !currently_open_class (scope))
23620 /* Enter the SCOPE so that name lookup will be resolved as if we
23621 were in the class definition. In particular, SCOPE will no
23622 longer be considered a dependent type. */
23623 pushed_scope = push_scope (scope);
23624 /* Look up the declaration. */
23625 decl = lookup_member (scope, name, /*protect=*/0, /*want_type=*/true,
23626 tf_warning_or_error);
23628 result = NULL_TREE;
23630 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
23631 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
23634 else if (identifier_p (TYPENAME_TYPE_FULLNAME (type))
23635 && TREE_CODE (decl) == TYPE_DECL)
23637 result = TREE_TYPE (decl);
23638 if (result == error_mark_node)
23639 result = NULL_TREE;
23641 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == TEMPLATE_ID_EXPR
23642 && DECL_CLASS_TEMPLATE_P (decl))
23646 /* Obtain the template and the arguments. */
23647 tmpl = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 0);
23648 args = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 1);
23649 /* Instantiate the template. */
23650 result = lookup_template_class (tmpl, args, NULL_TREE, NULL_TREE,
23651 /*entering_scope=*/0,
23652 tf_error | tf_user);
23653 if (result == error_mark_node)
23654 result = NULL_TREE;
23657 /* Leave the SCOPE. */
23659 pop_scope (pushed_scope);
23661 /* If we failed to resolve it, return the original typename. */
23665 /* If lookup found a typename type, resolve that too. */
23666 if (TREE_CODE (result) == TYPENAME_TYPE && !TYPENAME_IS_RESOLVING_P (result))
23668 /* Ill-formed programs can cause infinite recursion here, so we
23669 must catch that. */
23670 TYPENAME_IS_RESOLVING_P (result) = 1;
23671 result = resolve_typename_type (result, only_current_p);
23672 TYPENAME_IS_RESOLVING_P (result) = 0;
23675 /* Qualify the resulting type. */
23676 quals = cp_type_quals (type);
23678 result = cp_build_qualified_type (result, cp_type_quals (result) | quals);
23683 /* EXPR is an expression which is not type-dependent. Return a proxy
23684 for EXPR that can be used to compute the types of larger
23685 expressions containing EXPR. */
23688 build_non_dependent_expr (tree expr)
23692 /* When checking, try to get a constant value for all non-dependent
23693 expressions in order to expose bugs in *_dependent_expression_p
23694 and constexpr. This checking can change code generation, temporarily
23695 disabled. See PR70704. */
23696 if (0 && flag_checking && cxx_dialect >= cxx11
23697 /* Don't do this during nsdmi parsing as it can lead to
23698 unexpected recursive instantiations. */
23699 && !parsing_nsdmi ()
23700 /* Don't do this during concept expansion either and for
23701 the same reason. */
23702 && !expanding_concept ())
23703 fold_non_dependent_expr (expr);
23705 /* Preserve OVERLOADs; the functions must be available to resolve
23708 if (TREE_CODE (inner_expr) == STMT_EXPR)
23709 inner_expr = stmt_expr_value_expr (inner_expr);
23710 if (TREE_CODE (inner_expr) == ADDR_EXPR)
23711 inner_expr = TREE_OPERAND (inner_expr, 0);
23712 if (TREE_CODE (inner_expr) == COMPONENT_REF)
23713 inner_expr = TREE_OPERAND (inner_expr, 1);
23714 if (is_overloaded_fn (inner_expr)
23715 || TREE_CODE (inner_expr) == OFFSET_REF)
23717 /* There is no need to return a proxy for a variable. */
23720 /* Preserve string constants; conversions from string constants to
23721 "char *" are allowed, even though normally a "const char *"
23722 cannot be used to initialize a "char *". */
23723 if (TREE_CODE (expr) == STRING_CST)
23725 /* Preserve void and arithmetic constants, as an optimization -- there is no
23726 reason to create a new node. */
23727 if (TREE_CODE (expr) == VOID_CST
23728 || TREE_CODE (expr) == INTEGER_CST
23729 || TREE_CODE (expr) == REAL_CST)
23731 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
23732 There is at least one place where we want to know that a
23733 particular expression is a throw-expression: when checking a ?:
23734 expression, there are special rules if the second or third
23735 argument is a throw-expression. */
23736 if (TREE_CODE (expr) == THROW_EXPR)
23739 /* Don't wrap an initializer list, we need to be able to look inside. */
23740 if (BRACE_ENCLOSED_INITIALIZER_P (expr))
23743 /* Don't wrap a dummy object, we need to be able to test for it. */
23744 if (is_dummy_object (expr))
23747 if (TREE_CODE (expr) == COND_EXPR)
23748 return build3 (COND_EXPR,
23750 TREE_OPERAND (expr, 0),
23751 (TREE_OPERAND (expr, 1)
23752 ? build_non_dependent_expr (TREE_OPERAND (expr, 1))
23753 : build_non_dependent_expr (TREE_OPERAND (expr, 0))),
23754 build_non_dependent_expr (TREE_OPERAND (expr, 2)));
23755 if (TREE_CODE (expr) == COMPOUND_EXPR
23756 && !COMPOUND_EXPR_OVERLOADED (expr))
23757 return build2 (COMPOUND_EXPR,
23759 TREE_OPERAND (expr, 0),
23760 build_non_dependent_expr (TREE_OPERAND (expr, 1)));
23762 /* If the type is unknown, it can't really be non-dependent */
23763 gcc_assert (TREE_TYPE (expr) != unknown_type_node);
23765 /* Otherwise, build a NON_DEPENDENT_EXPR. */
23766 return build1 (NON_DEPENDENT_EXPR, TREE_TYPE (expr), expr);
23769 /* ARGS is a vector of expressions as arguments to a function call.
23770 Replace the arguments with equivalent non-dependent expressions.
23771 This modifies ARGS in place. */
23774 make_args_non_dependent (vec<tree, va_gc> *args)
23779 FOR_EACH_VEC_SAFE_ELT (args, ix, arg)
23781 tree newarg = build_non_dependent_expr (arg);
23783 (*args)[ix] = newarg;
23787 /* Returns a type which represents 'auto' or 'decltype(auto)'. We use a
23788 TEMPLATE_TYPE_PARM with a level one deeper than the actual template
23789 parms. If set_canonical is true, we set TYPE_CANONICAL on it. */
23792 make_auto_1 (tree name, bool set_canonical)
23794 tree au = cxx_make_type (TEMPLATE_TYPE_PARM);
23795 TYPE_NAME (au) = build_decl (input_location,
23796 TYPE_DECL, name, au);
23797 TYPE_STUB_DECL (au) = TYPE_NAME (au);
23798 TEMPLATE_TYPE_PARM_INDEX (au) = build_template_parm_index
23799 (0, processing_template_decl + 1, processing_template_decl + 1,
23800 TYPE_NAME (au), NULL_TREE);
23802 TYPE_CANONICAL (au) = canonical_type_parameter (au);
23803 DECL_ARTIFICIAL (TYPE_NAME (au)) = 1;
23804 SET_DECL_TEMPLATE_PARM_P (TYPE_NAME (au));
23810 make_decltype_auto (void)
23812 return make_auto_1 (get_identifier ("decltype(auto)"), true);
23818 return make_auto_1 (get_identifier ("auto"), true);
23821 /* Make a "constrained auto" type-specifier. This is an
23822 auto type with constraints that must be associated after
23823 deduction. The constraint is formed from the given
23824 CONC and its optional sequence of arguments, which are
23825 non-null if written as partial-concept-id. */
23828 make_constrained_auto (tree con, tree args)
23830 tree type = make_auto_1 (get_identifier ("auto"), false);
23832 /* Build the constraint. */
23833 tree tmpl = DECL_TI_TEMPLATE (con);
23836 expr = build_concept_check (tmpl, type, args);
23838 expr = build_concept_check (build_overload (tmpl, NULL_TREE), type, args);
23840 tree constr = normalize_expression (expr);
23841 PLACEHOLDER_TYPE_CONSTRAINTS (type) = constr;
23843 /* Our canonical type depends on the constraint. */
23844 TYPE_CANONICAL (type) = canonical_type_parameter (type);
23846 /* Attach the constraint to the type declaration. */
23847 tree decl = TYPE_NAME (type);
23851 /* Given type ARG, return std::initializer_list<ARG>. */
23856 tree std_init_list = namespace_binding
23857 (get_identifier ("initializer_list"), std_node);
23859 if (!std_init_list || !DECL_CLASS_TEMPLATE_P (std_init_list))
23861 error ("deducing from brace-enclosed initializer list requires "
23862 "#include <initializer_list>");
23863 return error_mark_node;
23865 argvec = make_tree_vec (1);
23866 TREE_VEC_ELT (argvec, 0) = arg;
23867 return lookup_template_class (std_init_list, argvec, NULL_TREE,
23868 NULL_TREE, 0, tf_warning_or_error);
23871 /* Replace auto in TYPE with std::initializer_list<auto>. */
23874 listify_autos (tree type, tree auto_node)
23876 tree init_auto = listify (auto_node);
23877 tree argvec = make_tree_vec (1);
23878 TREE_VEC_ELT (argvec, 0) = init_auto;
23879 if (processing_template_decl)
23880 argvec = add_to_template_args (current_template_args (), argvec);
23881 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
23884 /* Hash traits for hashing possibly constrained 'auto'
23885 TEMPLATE_TYPE_PARMs for use by do_auto_deduction. */
23887 struct auto_hash : default_hash_traits<tree>
23889 static inline hashval_t hash (tree);
23890 static inline bool equal (tree, tree);
23893 /* Hash the 'auto' T. */
23896 auto_hash::hash (tree t)
23898 if (tree c = PLACEHOLDER_TYPE_CONSTRAINTS (t))
23899 /* Matching constrained-type-specifiers denote the same template
23900 parameter, so hash the constraint. */
23901 return hash_placeholder_constraint (c);
23903 /* But unconstrained autos are all separate, so just hash the pointer. */
23904 return iterative_hash_object (t, 0);
23907 /* Compare two 'auto's. */
23910 auto_hash::equal (tree t1, tree t2)
23915 tree c1 = PLACEHOLDER_TYPE_CONSTRAINTS (t1);
23916 tree c2 = PLACEHOLDER_TYPE_CONSTRAINTS (t2);
23918 /* Two unconstrained autos are distinct. */
23922 return equivalent_placeholder_constraints (c1, c2);
23925 /* for_each_template_parm callback for extract_autos: if t is a (possibly
23926 constrained) auto, add it to the vector. */
23929 extract_autos_r (tree t, void *data)
23931 hash_table<auto_hash> &hash = *(hash_table<auto_hash>*)data;
23932 if (is_auto_or_concept (t))
23934 /* All the autos were built with index 0; fix that up now. */
23935 tree *p = hash.find_slot (t, INSERT);
23938 /* If this is a repeated constrained-type-specifier, use the index we
23940 idx = TEMPLATE_PARM_IDX (TEMPLATE_TYPE_PARM_INDEX (*p));
23943 /* Otherwise this is new, so use the current count. */
23945 idx = hash.elements () - 1;
23947 TEMPLATE_PARM_IDX (TEMPLATE_TYPE_PARM_INDEX (t)) = idx;
23950 /* Always keep walking. */
23954 /* Return a TREE_VEC of the 'auto's used in type under the Concepts TS, which
23955 says they can appear anywhere in the type. */
23958 extract_autos (tree type)
23960 hash_set<tree> visited;
23961 hash_table<auto_hash> hash (2);
23963 for_each_template_parm (type, extract_autos_r, &hash, &visited, true);
23965 tree tree_vec = make_tree_vec (hash.elements());
23966 for (hash_table<auto_hash>::iterator iter = hash.begin();
23967 iter != hash.end(); ++iter)
23970 unsigned i = TEMPLATE_PARM_IDX (TEMPLATE_TYPE_PARM_INDEX (elt));
23971 TREE_VEC_ELT (tree_vec, i)
23972 = build_tree_list (NULL_TREE, TYPE_NAME (elt));
23978 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
23979 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
23982 do_auto_deduction (tree type, tree init, tree auto_node)
23984 return do_auto_deduction (type, init, auto_node,
23985 tf_warning_or_error,
23989 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
23990 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE.
23991 The CONTEXT determines the context in which auto deduction is performed
23992 and is used to control error diagnostics.
23994 For partial-concept-ids, extra args may be appended to the list of deduced
23995 template arguments prior to determining constraint satisfaction. */
23998 do_auto_deduction (tree type, tree init, tree auto_node,
23999 tsubst_flags_t complain, auto_deduction_context context)
24003 if (init == error_mark_node)
24004 return error_mark_node;
24006 if (type_dependent_expression_p (init))
24007 /* Defining a subset of type-dependent expressions that we can deduce
24008 from ahead of time isn't worth the trouble. */
24011 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
24012 with either a new invented type template parameter U or, if the
24013 initializer is a braced-init-list (8.5.4), with
24014 std::initializer_list<U>. */
24015 if (BRACE_ENCLOSED_INITIALIZER_P (init))
24017 if (!DIRECT_LIST_INIT_P (init))
24018 type = listify_autos (type, auto_node);
24019 else if (CONSTRUCTOR_NELTS (init) == 1)
24020 init = CONSTRUCTOR_ELT (init, 0)->value;
24023 if (complain & tf_warning_or_error)
24025 if (permerror (input_location, "direct-list-initialization of "
24026 "%<auto%> requires exactly one element"))
24027 inform (input_location,
24028 "for deduction to %<std::initializer_list%>, use copy-"
24029 "list-initialization (i.e. add %<=%> before the %<{%>)");
24031 type = listify_autos (type, auto_node);
24035 if (type == error_mark_node)
24036 return error_mark_node;
24038 init = resolve_nondeduced_context (init, complain);
24040 if (AUTO_IS_DECLTYPE (auto_node))
24042 bool id = (DECL_P (init)
24043 || ((TREE_CODE (init) == COMPONENT_REF
24044 || TREE_CODE (init) == SCOPE_REF)
24045 && !REF_PARENTHESIZED_P (init)));
24046 targs = make_tree_vec (1);
24047 TREE_VEC_ELT (targs, 0)
24048 = finish_decltype_type (init, id, tf_warning_or_error);
24049 if (type != auto_node)
24051 if (complain & tf_error)
24052 error ("%qT as type rather than plain %<decltype(auto)%>", type);
24053 return error_mark_node;
24058 tree parms = build_tree_list (NULL_TREE, type);
24062 tparms = extract_autos (type);
24065 tparms = make_tree_vec (1);
24066 TREE_VEC_ELT (tparms, 0)
24067 = build_tree_list (NULL_TREE, TYPE_NAME (auto_node));
24070 targs = make_tree_vec (TREE_VEC_LENGTH (tparms));
24071 int val = type_unification_real (tparms, targs, parms, &init, 1, 0,
24072 DEDUCE_CALL, LOOKUP_NORMAL,
24073 NULL, /*explain_p=*/false);
24076 if (processing_template_decl)
24077 /* Try again at instantiation time. */
24079 if (type && type != error_mark_node
24080 && (complain & tf_error))
24081 /* If type is error_mark_node a diagnostic must have been
24082 emitted by now. Also, having a mention to '<type error>'
24083 in the diagnostic is not really useful to the user. */
24085 if (cfun && auto_node == current_function_auto_return_pattern
24086 && LAMBDA_FUNCTION_P (current_function_decl))
24087 error ("unable to deduce lambda return type from %qE", init);
24089 error ("unable to deduce %qT from %qE", type, init);
24090 type_unification_real (tparms, targs, parms, &init, 1, 0,
24091 DEDUCE_CALL, LOOKUP_NORMAL,
24092 NULL, /*explain_p=*/true);
24094 return error_mark_node;
24098 /* Check any placeholder constraints against the deduced type. */
24099 if (flag_concepts && !processing_template_decl)
24100 if (tree constr = PLACEHOLDER_TYPE_CONSTRAINTS (auto_node))
24102 /* Use the deduced type to check the associated constraints. If we
24103 have a partial-concept-id, rebuild the argument list so that
24104 we check using the extra arguments. */
24105 gcc_assert (TREE_CODE (constr) == CHECK_CONSTR);
24106 tree cargs = CHECK_CONSTR_ARGS (constr);
24107 if (TREE_VEC_LENGTH (cargs) > 1)
24109 cargs = copy_node (cargs);
24110 TREE_VEC_ELT (cargs, 0) = TREE_VEC_ELT (targs, 0);
24114 if (!constraints_satisfied_p (constr, cargs))
24116 if (complain & tf_warning_or_error)
24120 case adc_unspecified:
24121 error("placeholder constraints not satisfied");
24123 case adc_variable_type:
24124 error ("deduced initializer does not satisfy "
24125 "placeholder constraints");
24127 case adc_return_type:
24128 error ("deduced return type does not satisfy "
24129 "placeholder constraints");
24131 case adc_requirement:
24132 error ("deduced expression type does not saatisy "
24133 "placeholder constraints");
24136 diagnose_constraints (input_location, constr, targs);
24138 return error_mark_node;
24142 if (processing_template_decl)
24143 targs = add_to_template_args (current_template_args (), targs);
24144 return tsubst (type, targs, complain, NULL_TREE);
24147 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
24151 splice_late_return_type (tree type, tree late_return_type)
24153 if (is_auto (type))
24155 if (late_return_type)
24156 return late_return_type;
24158 tree idx = get_template_parm_index (type);
24159 if (TEMPLATE_PARM_LEVEL (idx) <= processing_template_decl)
24160 /* In an abbreviated function template we didn't know we were dealing
24161 with a function template when we saw the auto return type, so update
24162 it to have the correct level. */
24163 return make_auto_1 (TYPE_IDENTIFIER (type), true);
24168 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto' or
24169 'decltype(auto)'. */
24172 is_auto (const_tree type)
24174 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
24175 && (TYPE_IDENTIFIER (type) == get_identifier ("auto")
24176 || TYPE_IDENTIFIER (type) == get_identifier ("decltype(auto)")))
24182 /* for_each_template_parm callback for type_uses_auto. */
24185 is_auto_r (tree tp, void */*data*/)
24187 return is_auto_or_concept (tp);
24190 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing `auto' iff TYPE contains
24191 a use of `auto'. Returns NULL_TREE otherwise. */
24194 type_uses_auto (tree type)
24196 if (type == NULL_TREE)
24198 else if (flag_concepts)
24200 /* The Concepts TS allows multiple autos in one type-specifier; just
24201 return the first one we find, do_auto_deduction will collect all of
24203 if (uses_template_parms (type))
24204 return for_each_template_parm (type, is_auto_r, /*data*/NULL,
24205 /*visited*/NULL, /*nondeduced*/true);
24210 return find_type_usage (type, is_auto);
24213 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto',
24214 'decltype(auto)' or a concept. */
24217 is_auto_or_concept (const_tree type)
24219 return is_auto (type); // or concept
24222 /* Returns the TEMPLATE_TYPE_PARM in TYPE representing a generic type (`auto' or
24223 a concept identifier) iff TYPE contains a use of a generic type. Returns
24224 NULL_TREE otherwise. */
24227 type_uses_auto_or_concept (tree type)
24229 return find_type_usage (type, is_auto_or_concept);
24233 /* For a given template T, return the vector of typedefs referenced
24234 in T for which access check is needed at T instantiation time.
24235 T is either a FUNCTION_DECL or a RECORD_TYPE.
24236 Those typedefs were added to T by the function
24237 append_type_to_template_for_access_check. */
24239 vec<qualified_typedef_usage_t, va_gc> *
24240 get_types_needing_access_check (tree t)
24243 vec<qualified_typedef_usage_t, va_gc> *result = NULL;
24245 if (!t || t == error_mark_node)
24248 if (!(ti = get_template_info (t)))
24251 if (CLASS_TYPE_P (t)
24252 || TREE_CODE (t) == FUNCTION_DECL)
24254 if (!TI_TEMPLATE (ti))
24257 result = TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti);
24263 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
24264 tied to T. That list of typedefs will be access checked at
24265 T instantiation time.
24266 T is either a FUNCTION_DECL or a RECORD_TYPE.
24267 TYPE_DECL is a TYPE_DECL node representing a typedef.
24268 SCOPE is the scope through which TYPE_DECL is accessed.
24269 LOCATION is the location of the usage point of TYPE_DECL.
24271 This function is a subroutine of
24272 append_type_to_template_for_access_check. */
24275 append_type_to_template_for_access_check_1 (tree t,
24278 location_t location)
24280 qualified_typedef_usage_t typedef_usage;
24283 if (!t || t == error_mark_node)
24286 gcc_assert ((TREE_CODE (t) == FUNCTION_DECL
24287 || CLASS_TYPE_P (t))
24289 && TREE_CODE (type_decl) == TYPE_DECL
24292 if (!(ti = get_template_info (t)))
24295 gcc_assert (TI_TEMPLATE (ti));
24297 typedef_usage.typedef_decl = type_decl;
24298 typedef_usage.context = scope;
24299 typedef_usage.locus = location;
24301 vec_safe_push (TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti), typedef_usage);
24304 /* Append TYPE_DECL to the template TEMPL.
24305 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
24306 At TEMPL instanciation time, TYPE_DECL will be checked to see
24307 if it can be accessed through SCOPE.
24308 LOCATION is the location of the usage point of TYPE_DECL.
24310 e.g. consider the following code snippet:
24317 template<class U> struct S
24319 C::myint mi; // <-- usage point of the typedef C::myint
24324 At S<char> instantiation time, we need to check the access of C::myint
24325 In other words, we need to check the access of the myint typedef through
24326 the C scope. For that purpose, this function will add the myint typedef
24327 and the scope C through which its being accessed to a list of typedefs
24328 tied to the template S. That list will be walked at template instantiation
24329 time and access check performed on each typedefs it contains.
24330 Note that this particular code snippet should yield an error because
24331 myint is private to C. */
24334 append_type_to_template_for_access_check (tree templ,
24337 location_t location)
24339 qualified_typedef_usage_t *iter;
24342 gcc_assert (type_decl && (TREE_CODE (type_decl) == TYPE_DECL));
24344 /* Make sure we don't append the type to the template twice. */
24345 FOR_EACH_VEC_SAFE_ELT (get_types_needing_access_check (templ), i, iter)
24346 if (iter->typedef_decl == type_decl && scope == iter->context)
24349 append_type_to_template_for_access_check_1 (templ, type_decl,
24353 /* Convert the generic type parameters in PARM that match the types given in the
24354 range [START_IDX, END_IDX) from the current_template_parms into generic type
24358 convert_generic_types_to_packs (tree parm, int start_idx, int end_idx)
24360 tree current = current_template_parms;
24361 int depth = TMPL_PARMS_DEPTH (current);
24362 current = INNERMOST_TEMPLATE_PARMS (current);
24363 tree replacement = make_tree_vec (TREE_VEC_LENGTH (current));
24365 for (int i = 0; i < start_idx; ++i)
24366 TREE_VEC_ELT (replacement, i)
24367 = TREE_TYPE (TREE_VALUE (TREE_VEC_ELT (current, i)));
24369 for (int i = start_idx; i < end_idx; ++i)
24371 /* Create a distinct parameter pack type from the current parm and add it
24372 to the replacement args to tsubst below into the generic function
24375 tree o = TREE_TYPE (TREE_VALUE
24376 (TREE_VEC_ELT (current, i)));
24377 tree t = copy_type (o);
24378 TEMPLATE_TYPE_PARM_INDEX (t)
24379 = reduce_template_parm_level (TEMPLATE_TYPE_PARM_INDEX (o),
24381 TREE_TYPE (TEMPLATE_TYPE_DECL (t)) = t;
24382 TYPE_STUB_DECL (t) = TYPE_NAME (t) = TEMPLATE_TYPE_DECL (t);
24383 TYPE_MAIN_VARIANT (t) = t;
24384 TEMPLATE_TYPE_PARAMETER_PACK (t) = true;
24385 TYPE_CANONICAL (t) = canonical_type_parameter (t);
24386 TREE_VEC_ELT (replacement, i) = t;
24387 TREE_VALUE (TREE_VEC_ELT (current, i)) = TREE_CHAIN (t);
24390 for (int i = end_idx, e = TREE_VEC_LENGTH (current); i < e; ++i)
24391 TREE_VEC_ELT (replacement, i)
24392 = TREE_TYPE (TREE_VALUE (TREE_VEC_ELT (current, i)));
24394 /* If there are more levels then build up the replacement with the outer
24397 replacement = add_to_template_args (template_parms_to_args
24398 (TREE_CHAIN (current_template_parms)),
24401 return tsubst (parm, replacement, tf_none, NULL_TREE);
24404 /* Entries in the decl_constraint hash table. */
24405 struct GTY((for_user)) constr_entry
24411 /* Hashing function and equality for constraint entries. */
24412 struct constr_hasher : ggc_ptr_hash<constr_entry>
24414 static hashval_t hash (constr_entry *e)
24416 return (hashval_t)DECL_UID (e->decl);
24419 static bool equal (constr_entry *e1, constr_entry *e2)
24421 return e1->decl == e2->decl;
24425 /* A mapping from declarations to constraint information. Note that
24426 both templates and their underlying declarations are mapped to the
24427 same constraint information.
24429 FIXME: This is defined in pt.c because garbage collection
24430 code is not being generated for constraint.cc. */
24432 static GTY (()) hash_table<constr_hasher> *decl_constraints;
24434 /* Returns the template constraints of declaration T. If T is not
24435 constrained, return NULL_TREE. Note that T must be non-null. */
24438 get_constraints (tree t)
24440 if (!flag_concepts)
24443 gcc_assert (DECL_P (t));
24444 if (TREE_CODE (t) == TEMPLATE_DECL)
24445 t = DECL_TEMPLATE_RESULT (t);
24446 constr_entry elt = { t, NULL_TREE };
24447 constr_entry* found = decl_constraints->find (&elt);
24454 /* Associate the given constraint information CI with the declaration
24455 T. If T is a template, then the constraints are associated with
24456 its underlying declaration. Don't build associations if CI is
24460 set_constraints (tree t, tree ci)
24464 gcc_assert (t && flag_concepts);
24465 if (TREE_CODE (t) == TEMPLATE_DECL)
24466 t = DECL_TEMPLATE_RESULT (t);
24467 gcc_assert (!get_constraints (t));
24468 constr_entry elt = {t, ci};
24469 constr_entry** slot = decl_constraints->find_slot (&elt, INSERT);
24470 constr_entry* entry = ggc_alloc<constr_entry> ();
24475 /* Remove the associated constraints of the declaration T. */
24478 remove_constraints (tree t)
24480 gcc_assert (DECL_P (t));
24481 if (TREE_CODE (t) == TEMPLATE_DECL)
24482 t = DECL_TEMPLATE_RESULT (t);
24484 constr_entry elt = {t, NULL_TREE};
24485 constr_entry** slot = decl_constraints->find_slot (&elt, NO_INSERT);
24487 decl_constraints->clear_slot (slot);
24490 /* Memoized satisfaction results for declarations. This
24491 maps the pair (constraint_info, arguments) to the result computed
24492 by constraints_satisfied_p. */
24494 struct GTY((for_user)) constraint_sat_entry
24501 /* Hashing function and equality for constraint entries. */
24503 struct constraint_sat_hasher : ggc_ptr_hash<constraint_sat_entry>
24505 static hashval_t hash (constraint_sat_entry *e)
24507 hashval_t val = iterative_hash_object(e->ci, 0);
24508 return iterative_hash_template_arg (e->args, val);
24511 static bool equal (constraint_sat_entry *e1, constraint_sat_entry *e2)
24513 return e1->ci == e2->ci && comp_template_args (e1->args, e2->args);
24517 /* Memoized satisfaction results for concept checks. */
24519 struct GTY((for_user)) concept_spec_entry
24526 /* Hashing function and equality for constraint entries. */
24528 struct concept_spec_hasher : ggc_ptr_hash<concept_spec_entry>
24530 static hashval_t hash (concept_spec_entry *e)
24532 return hash_tmpl_and_args (e->tmpl, e->args);
24535 static bool equal (concept_spec_entry *e1, concept_spec_entry *e2)
24537 ++comparing_specializations;
24538 bool eq = e1->tmpl == e2->tmpl && comp_template_args (e1->args, e2->args);
24539 --comparing_specializations;
24544 static GTY (()) hash_table<constraint_sat_hasher> *constraint_memos;
24545 static GTY (()) hash_table<concept_spec_hasher> *concept_memos;
24547 /* Search for a memoized satisfaction result. Returns one of the
24548 truth value nodes if previously memoized, or NULL_TREE otherwise. */
24551 lookup_constraint_satisfaction (tree ci, tree args)
24553 constraint_sat_entry elt = { ci, args, NULL_TREE };
24554 constraint_sat_entry* found = constraint_memos->find (&elt);
24556 return found->result;
24561 /* Memoize the result of a satisfication test. Returns the saved result. */
24564 memoize_constraint_satisfaction (tree ci, tree args, tree result)
24566 constraint_sat_entry elt = {ci, args, result};
24567 constraint_sat_entry** slot = constraint_memos->find_slot (&elt, INSERT);
24568 constraint_sat_entry* entry = ggc_alloc<constraint_sat_entry> ();
24574 /* Search for a memoized satisfaction result for a concept. */
24577 lookup_concept_satisfaction (tree tmpl, tree args)
24579 concept_spec_entry elt = { tmpl, args, NULL_TREE };
24580 concept_spec_entry* found = concept_memos->find (&elt);
24582 return found->result;
24587 /* Memoize the result of a concept check. Returns the saved result. */
24590 memoize_concept_satisfaction (tree tmpl, tree args, tree result)
24592 concept_spec_entry elt = {tmpl, args, result};
24593 concept_spec_entry** slot = concept_memos->find_slot (&elt, INSERT);
24594 concept_spec_entry* entry = ggc_alloc<concept_spec_entry> ();
24600 static GTY (()) hash_table<concept_spec_hasher> *concept_expansions;
24602 /* Returns a prior concept specialization. This returns the substituted
24603 and normalized constraints defined by the concept. */
24606 get_concept_expansion (tree tmpl, tree args)
24608 concept_spec_entry elt = { tmpl, args, NULL_TREE };
24609 concept_spec_entry* found = concept_expansions->find (&elt);
24611 return found->result;
24616 /* Save a concept expansion for later. */
24619 save_concept_expansion (tree tmpl, tree args, tree def)
24621 concept_spec_entry elt = {tmpl, args, def};
24622 concept_spec_entry** slot = concept_expansions->find_slot (&elt, INSERT);
24623 concept_spec_entry* entry = ggc_alloc<concept_spec_entry> ();
24630 hash_subsumption_args (tree t1, tree t2)
24632 gcc_assert (TREE_CODE (t1) == CHECK_CONSTR);
24633 gcc_assert (TREE_CODE (t2) == CHECK_CONSTR);
24635 val = iterative_hash_object (CHECK_CONSTR_CONCEPT (t1), val);
24636 val = iterative_hash_template_arg (CHECK_CONSTR_ARGS (t1), val);
24637 val = iterative_hash_object (CHECK_CONSTR_CONCEPT (t2), val);
24638 val = iterative_hash_template_arg (CHECK_CONSTR_ARGS (t2), val);
24642 /* Compare the constraints of two subsumption entries. The LEFT1 and
24643 LEFT2 arguments comprise the first subsumption pair and the RIGHT1
24644 and RIGHT2 arguments comprise the second. These are all CHECK_CONSTRs. */
24647 comp_subsumption_args (tree left1, tree left2, tree right1, tree right2)
24649 if (CHECK_CONSTR_CONCEPT (left1) == CHECK_CONSTR_CONCEPT (right1))
24650 if (CHECK_CONSTR_CONCEPT (left2) == CHECK_CONSTR_CONCEPT (right2))
24651 if (comp_template_args (CHECK_CONSTR_ARGS (left1),
24652 CHECK_CONSTR_ARGS (right1)))
24653 return comp_template_args (CHECK_CONSTR_ARGS (left2),
24654 CHECK_CONSTR_ARGS (right2));
24658 /* Key/value pair for learning and memoizing subsumption results. This
24659 associates a pair of check constraints (including arguments) with
24660 a boolean value indicating the result. */
24662 struct GTY((for_user)) subsumption_entry
24669 /* Hashing function and equality for constraint entries. */
24671 struct subsumption_hasher : ggc_ptr_hash<subsumption_entry>
24673 static hashval_t hash (subsumption_entry *e)
24675 return hash_subsumption_args (e->t1, e->t2);
24678 static bool equal (subsumption_entry *e1, subsumption_entry *e2)
24680 ++comparing_specializations;
24681 bool eq = comp_subsumption_args(e1->t1, e1->t2, e2->t1, e2->t2);
24682 --comparing_specializations;
24687 static GTY (()) hash_table<subsumption_hasher> *subsumption_table;
24689 /* Search for a previously cached subsumption result. */
24692 lookup_subsumption_result (tree t1, tree t2)
24694 subsumption_entry elt = { t1, t2, false };
24695 subsumption_entry* found = subsumption_table->find (&elt);
24697 return &found->result;
24702 /* Save a subsumption result. */
24705 save_subsumption_result (tree t1, tree t2, bool result)
24707 subsumption_entry elt = {t1, t2, result};
24708 subsumption_entry** slot = subsumption_table->find_slot (&elt, INSERT);
24709 subsumption_entry* entry = ggc_alloc<subsumption_entry> ();
24715 /* Set up the hash table for constraint association. */
24718 init_constraint_processing (void)
24720 if (!flag_concepts)
24723 decl_constraints = hash_table<constr_hasher>::create_ggc(37);
24724 constraint_memos = hash_table<constraint_sat_hasher>::create_ggc(37);
24725 concept_memos = hash_table<concept_spec_hasher>::create_ggc(37);
24726 concept_expansions = hash_table<concept_spec_hasher>::create_ggc(37);
24727 subsumption_table = hash_table<subsumption_hasher>::create_ggc(37);
24730 /* Set up the hash tables for template instantiations. */
24733 init_template_processing (void)
24735 decl_specializations = hash_table<spec_hasher>::create_ggc (37);
24736 type_specializations = hash_table<spec_hasher>::create_ggc (37);
24739 /* Print stats about the template hash tables for -fstats. */
24742 print_template_statistics (void)
24744 fprintf (stderr, "decl_specializations: size %ld, %ld elements, "
24745 "%f collisions\n", (long) decl_specializations->size (),
24746 (long) decl_specializations->elements (),
24747 decl_specializations->collisions ());
24748 fprintf (stderr, "type_specializations: size %ld, %ld elements, "
24749 "%f collisions\n", (long) type_specializations->size (),
24750 (long) type_specializations->elements (),
24751 type_specializations->collisions ());
24754 #include "gt-cp-pt.h"