1 /* Handle parameterized types (templates) for GNU C++.
2 Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
3 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010, 2011
4 Free Software Foundation, Inc.
5 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
6 Rewritten by Jason Merrill (jason@cygnus.com).
8 This file is part of GCC.
10 GCC is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3, or (at your option)
15 GCC is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with GCC; see the file COPYING3. If not see
22 <http://www.gnu.org/licenses/>. */
24 /* Known bugs or deficiencies include:
26 all methods must be provided in header files; can't use a source
27 file that contains only the method templates and "just win". */
31 #include "coretypes.h"
35 #include "pointer-set.h"
38 #include "c-family/c-common.h"
39 #include "c-family/c-objc.h"
40 #include "cp-objcp-common.h"
41 #include "tree-inline.h"
46 #include "tree-iterator.h"
49 /* The type of functions taking a tree, and some additional data, and
51 typedef int (*tree_fn_t) (tree, void*);
53 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
54 instantiations have been deferred, either because their definitions
55 were not yet available, or because we were putting off doing the work. */
56 struct GTY ((chain_next ("%h.next"))) pending_template {
57 struct pending_template *next;
58 struct tinst_level *tinst;
61 static GTY(()) struct pending_template *pending_templates;
62 static GTY(()) struct pending_template *last_pending_template;
64 int processing_template_parmlist;
65 static int template_header_count;
67 static GTY(()) tree saved_trees;
68 static VEC(int,heap) *inline_parm_levels;
70 static GTY(()) struct tinst_level *current_tinst_level;
72 static GTY(()) tree saved_access_scope;
74 /* Live only within one (recursive) call to tsubst_expr. We use
75 this to pass the statement expression node from the STMT_EXPR
76 to the EXPR_STMT that is its result. */
77 static tree cur_stmt_expr;
79 /* A map from local variable declarations in the body of the template
80 presently being instantiated to the corresponding instantiated
82 static htab_t local_specializations;
84 typedef struct GTY(()) spec_entry
91 static GTY ((param_is (spec_entry)))
92 htab_t decl_specializations;
94 static GTY ((param_is (spec_entry)))
95 htab_t type_specializations;
97 /* Contains canonical template parameter types. The vector is indexed by
98 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
99 TREE_LIST, whose TREE_VALUEs contain the canonical template
100 parameters of various types and levels. */
101 static GTY(()) VEC(tree,gc) *canonical_template_parms;
103 #define UNIFY_ALLOW_NONE 0
104 #define UNIFY_ALLOW_MORE_CV_QUAL 1
105 #define UNIFY_ALLOW_LESS_CV_QUAL 2
106 #define UNIFY_ALLOW_DERIVED 4
107 #define UNIFY_ALLOW_INTEGER 8
108 #define UNIFY_ALLOW_OUTER_LEVEL 16
109 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
110 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
112 enum template_base_result {
114 tbr_ambiguous_baseclass,
118 static void push_access_scope (tree);
119 static void pop_access_scope (tree);
120 static void push_deduction_access_scope (tree);
121 static void pop_deduction_access_scope (tree);
122 static bool resolve_overloaded_unification (tree, tree, tree, tree,
123 unification_kind_t, int,
125 static int try_one_overload (tree, tree, tree, tree, tree,
126 unification_kind_t, int, bool, bool);
127 static int unify (tree, tree, tree, tree, int, bool);
128 static void add_pending_template (tree);
129 static tree reopen_tinst_level (struct tinst_level *);
130 static tree tsubst_initializer_list (tree, tree);
131 static tree get_class_bindings (tree, tree, tree);
132 static tree coerce_template_parms (tree, tree, tree, tsubst_flags_t,
134 static void tsubst_enum (tree, tree, tree);
135 static tree add_to_template_args (tree, tree);
136 static tree add_outermost_template_args (tree, tree);
137 static bool check_instantiated_args (tree, tree, tsubst_flags_t);
138 static int maybe_adjust_types_for_deduction (unification_kind_t, tree*, tree*,
140 static int type_unification_real (tree, tree, tree, const tree *,
141 unsigned int, int, unification_kind_t, int,
143 static void note_template_header (int);
144 static tree convert_nontype_argument_function (tree, tree);
145 static tree convert_nontype_argument (tree, tree, tsubst_flags_t);
146 static tree convert_template_argument (tree, tree, tree,
147 tsubst_flags_t, int, tree);
148 static int for_each_template_parm (tree, tree_fn_t, void*,
149 struct pointer_set_t*, bool);
150 static tree expand_template_argument_pack (tree);
151 static tree build_template_parm_index (int, int, int, int, tree, tree);
152 static bool inline_needs_template_parms (tree);
153 static void push_inline_template_parms_recursive (tree, int);
154 static tree retrieve_local_specialization (tree);
155 static void register_local_specialization (tree, tree);
156 static hashval_t hash_specialization (const void *p);
157 static tree reduce_template_parm_level (tree, tree, int, tree, tsubst_flags_t);
158 static int mark_template_parm (tree, void *);
159 static int template_parm_this_level_p (tree, void *);
160 static tree tsubst_friend_function (tree, tree);
161 static tree tsubst_friend_class (tree, tree);
162 static int can_complete_type_without_circularity (tree);
163 static tree get_bindings (tree, tree, tree, bool);
164 static int template_decl_level (tree);
165 static int check_cv_quals_for_unify (int, tree, tree);
166 static void template_parm_level_and_index (tree, int*, int*);
167 static int unify_pack_expansion (tree, tree, tree,
168 tree, unification_kind_t, bool, bool);
169 static tree tsubst_template_arg (tree, tree, tsubst_flags_t, tree);
170 static tree tsubst_template_args (tree, tree, tsubst_flags_t, tree);
171 static tree tsubst_template_parms (tree, tree, tsubst_flags_t);
172 static void regenerate_decl_from_template (tree, tree);
173 static tree most_specialized_class (tree, tree, tsubst_flags_t);
174 static tree tsubst_aggr_type (tree, tree, tsubst_flags_t, tree, int);
175 static tree tsubst_arg_types (tree, tree, tsubst_flags_t, tree);
176 static tree tsubst_function_type (tree, tree, tsubst_flags_t, tree);
177 static bool check_specialization_scope (void);
178 static tree process_partial_specialization (tree);
179 static void set_current_access_from_decl (tree);
180 static enum template_base_result get_template_base (tree, tree, tree, tree,
182 static tree try_class_unification (tree, tree, tree, tree, bool);
183 static int coerce_template_template_parms (tree, tree, tsubst_flags_t,
185 static bool template_template_parm_bindings_ok_p (tree, tree);
186 static int template_args_equal (tree, tree);
187 static void tsubst_default_arguments (tree);
188 static tree for_each_template_parm_r (tree *, int *, void *);
189 static tree copy_default_args_to_explicit_spec_1 (tree, tree);
190 static void copy_default_args_to_explicit_spec (tree);
191 static int invalid_nontype_parm_type_p (tree, tsubst_flags_t);
192 static int eq_local_specializations (const void *, const void *);
193 static bool dependent_template_arg_p (tree);
194 static bool any_template_arguments_need_structural_equality_p (tree);
195 static bool dependent_type_p_r (tree);
196 static tree tsubst_expr (tree, tree, tsubst_flags_t, tree, bool);
197 static tree tsubst_copy (tree, tree, tsubst_flags_t, tree);
198 static tree tsubst_pack_expansion (tree, tree, tsubst_flags_t, tree);
199 static tree tsubst_decl (tree, tree, tsubst_flags_t);
200 static void perform_typedefs_access_check (tree tmpl, tree targs);
201 static void append_type_to_template_for_access_check_1 (tree, tree, tree,
203 static tree listify (tree);
204 static tree listify_autos (tree, tree);
205 static tree template_parm_to_arg (tree t);
206 static bool arg_from_parm_pack_p (tree, tree);
207 static tree current_template_args (void);
208 static tree fixup_template_type_parm_type (tree, int);
209 static tree fixup_template_parm_index (tree, tree, int);
210 static tree tsubst_template_parm (tree, tree, tsubst_flags_t);
212 /* Make the current scope suitable for access checking when we are
213 processing T. T can be FUNCTION_DECL for instantiated function
214 template, or VAR_DECL for static member variable (need by
215 instantiate_decl). */
218 push_access_scope (tree t)
220 gcc_assert (TREE_CODE (t) == FUNCTION_DECL
221 || TREE_CODE (t) == VAR_DECL);
223 if (DECL_FRIEND_CONTEXT (t))
224 push_nested_class (DECL_FRIEND_CONTEXT (t));
225 else if (DECL_CLASS_SCOPE_P (t))
226 push_nested_class (DECL_CONTEXT (t));
228 push_to_top_level ();
230 if (TREE_CODE (t) == FUNCTION_DECL)
232 saved_access_scope = tree_cons
233 (NULL_TREE, current_function_decl, saved_access_scope);
234 current_function_decl = t;
238 /* Restore the scope set up by push_access_scope. T is the node we
242 pop_access_scope (tree t)
244 if (TREE_CODE (t) == FUNCTION_DECL)
246 current_function_decl = TREE_VALUE (saved_access_scope);
247 saved_access_scope = TREE_CHAIN (saved_access_scope);
250 if (DECL_FRIEND_CONTEXT (t) || DECL_CLASS_SCOPE_P (t))
253 pop_from_top_level ();
256 /* Do any processing required when DECL (a member template
257 declaration) is finished. Returns the TEMPLATE_DECL corresponding
258 to DECL, unless it is a specialization, in which case the DECL
259 itself is returned. */
262 finish_member_template_decl (tree decl)
264 if (decl == error_mark_node)
265 return error_mark_node;
267 gcc_assert (DECL_P (decl));
269 if (TREE_CODE (decl) == TYPE_DECL)
273 type = TREE_TYPE (decl);
274 if (type == error_mark_node)
275 return error_mark_node;
276 if (MAYBE_CLASS_TYPE_P (type)
277 && CLASSTYPE_TEMPLATE_INFO (type)
278 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
280 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
281 check_member_template (tmpl);
286 else if (TREE_CODE (decl) == FIELD_DECL)
287 error ("data member %qD cannot be a member template", decl);
288 else if (DECL_TEMPLATE_INFO (decl))
290 if (!DECL_TEMPLATE_SPECIALIZATION (decl))
292 check_member_template (DECL_TI_TEMPLATE (decl));
293 return DECL_TI_TEMPLATE (decl);
299 error ("invalid member template declaration %qD", decl);
301 return error_mark_node;
304 /* Create a template info node. */
307 build_template_info (tree template_decl, tree template_args)
309 tree result = make_node (TEMPLATE_INFO);
310 TI_TEMPLATE (result) = template_decl;
311 TI_ARGS (result) = template_args;
315 /* Return the template info node corresponding to T, whatever T is. */
318 get_template_info (const_tree t)
320 tree tinfo = NULL_TREE;
322 if (!t || t == error_mark_node)
325 if (DECL_P (t) && DECL_LANG_SPECIFIC (t))
326 tinfo = DECL_TEMPLATE_INFO (t);
328 if (!tinfo && DECL_IMPLICIT_TYPEDEF_P (t))
331 if (TAGGED_TYPE_P (t))
332 tinfo = TYPE_TEMPLATE_INFO (t);
333 else if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
334 tinfo = TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (t);
339 /* Returns the template nesting level of the indicated class TYPE.
349 A<T>::B<U> has depth two, while A<T> has depth one.
350 Both A<T>::B<int> and A<int>::B<U> have depth one, if
351 they are instantiations, not specializations.
353 This function is guaranteed to return 0 if passed NULL_TREE so
354 that, for example, `template_class_depth (current_class_type)' is
358 template_class_depth (tree type)
363 type && TREE_CODE (type) != NAMESPACE_DECL;
364 type = (TREE_CODE (type) == FUNCTION_DECL)
365 ? CP_DECL_CONTEXT (type) : CP_TYPE_CONTEXT (type))
367 tree tinfo = get_template_info (type);
369 if (tinfo && PRIMARY_TEMPLATE_P (TI_TEMPLATE (tinfo))
370 && uses_template_parms (INNERMOST_TEMPLATE_ARGS (TI_ARGS (tinfo))))
377 /* Subroutine of maybe_begin_member_template_processing.
378 Returns true if processing DECL needs us to push template parms. */
381 inline_needs_template_parms (tree decl)
383 if (! DECL_TEMPLATE_INFO (decl))
386 return (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (most_general_template (decl)))
387 > (processing_template_decl + DECL_TEMPLATE_SPECIALIZATION (decl)));
390 /* Subroutine of maybe_begin_member_template_processing.
391 Push the template parms in PARMS, starting from LEVELS steps into the
392 chain, and ending at the beginning, since template parms are listed
396 push_inline_template_parms_recursive (tree parmlist, int levels)
398 tree parms = TREE_VALUE (parmlist);
402 push_inline_template_parms_recursive (TREE_CHAIN (parmlist), levels - 1);
404 ++processing_template_decl;
405 current_template_parms
406 = tree_cons (size_int (processing_template_decl),
407 parms, current_template_parms);
408 TEMPLATE_PARMS_FOR_INLINE (current_template_parms) = 1;
410 begin_scope (TREE_VEC_LENGTH (parms) ? sk_template_parms : sk_template_spec,
412 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
414 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
416 if (parm == error_mark_node)
419 gcc_assert (DECL_P (parm));
421 switch (TREE_CODE (parm))
430 /* Make a CONST_DECL as is done in process_template_parm.
431 It is ugly that we recreate this here; the original
432 version built in process_template_parm is no longer
434 tree decl = build_decl (DECL_SOURCE_LOCATION (parm),
435 CONST_DECL, DECL_NAME (parm),
437 DECL_ARTIFICIAL (decl) = 1;
438 TREE_CONSTANT (decl) = 1;
439 TREE_READONLY (decl) = 1;
440 DECL_INITIAL (decl) = DECL_INITIAL (parm);
441 SET_DECL_TEMPLATE_PARM_P (decl);
452 /* Restore the template parameter context for a member template or
453 a friend template defined in a class definition. */
456 maybe_begin_member_template_processing (tree decl)
461 if (inline_needs_template_parms (decl))
463 parms = DECL_TEMPLATE_PARMS (most_general_template (decl));
464 levels = TMPL_PARMS_DEPTH (parms) - processing_template_decl;
466 if (DECL_TEMPLATE_SPECIALIZATION (decl))
469 parms = TREE_CHAIN (parms);
472 push_inline_template_parms_recursive (parms, levels);
475 /* Remember how many levels of template parameters we pushed so that
476 we can pop them later. */
477 VEC_safe_push (int, heap, inline_parm_levels, levels);
480 /* Undo the effects of maybe_begin_member_template_processing. */
483 maybe_end_member_template_processing (void)
488 if (VEC_length (int, inline_parm_levels) == 0)
491 last = VEC_pop (int, inline_parm_levels);
492 for (i = 0; i < last; ++i)
494 --processing_template_decl;
495 current_template_parms = TREE_CHAIN (current_template_parms);
500 /* Return a new template argument vector which contains all of ARGS,
501 but has as its innermost set of arguments the EXTRA_ARGS. */
504 add_to_template_args (tree args, tree extra_args)
511 if (args == NULL_TREE || extra_args == error_mark_node)
514 extra_depth = TMPL_ARGS_DEPTH (extra_args);
515 new_args = make_tree_vec (TMPL_ARGS_DEPTH (args) + extra_depth);
517 for (i = 1; i <= TMPL_ARGS_DEPTH (args); ++i)
518 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (args, i));
520 for (j = 1; j <= extra_depth; ++j, ++i)
521 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (extra_args, j));
526 /* Like add_to_template_args, but only the outermost ARGS are added to
527 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
528 (EXTRA_ARGS) levels are added. This function is used to combine
529 the template arguments from a partial instantiation with the
530 template arguments used to attain the full instantiation from the
531 partial instantiation. */
534 add_outermost_template_args (tree args, tree extra_args)
538 /* If there are more levels of EXTRA_ARGS than there are ARGS,
539 something very fishy is going on. */
540 gcc_assert (TMPL_ARGS_DEPTH (args) >= TMPL_ARGS_DEPTH (extra_args));
542 /* If *all* the new arguments will be the EXTRA_ARGS, just return
544 if (TMPL_ARGS_DEPTH (args) == TMPL_ARGS_DEPTH (extra_args))
547 /* For the moment, we make ARGS look like it contains fewer levels. */
548 TREE_VEC_LENGTH (args) -= TMPL_ARGS_DEPTH (extra_args);
550 new_args = add_to_template_args (args, extra_args);
552 /* Now, we restore ARGS to its full dimensions. */
553 TREE_VEC_LENGTH (args) += TMPL_ARGS_DEPTH (extra_args);
558 /* Return the N levels of innermost template arguments from the ARGS. */
561 get_innermost_template_args (tree args, int n)
569 /* If N is 1, just return the innermost set of template arguments. */
571 return TMPL_ARGS_LEVEL (args, TMPL_ARGS_DEPTH (args));
573 /* If we're not removing anything, just return the arguments we were
575 extra_levels = TMPL_ARGS_DEPTH (args) - n;
576 gcc_assert (extra_levels >= 0);
577 if (extra_levels == 0)
580 /* Make a new set of arguments, not containing the outer arguments. */
581 new_args = make_tree_vec (n);
582 for (i = 1; i <= n; ++i)
583 SET_TMPL_ARGS_LEVEL (new_args, i,
584 TMPL_ARGS_LEVEL (args, i + extra_levels));
589 /* The inverse of get_innermost_template_args: Return all but the innermost
590 EXTRA_LEVELS levels of template arguments from the ARGS. */
593 strip_innermost_template_args (tree args, int extra_levels)
596 int n = TMPL_ARGS_DEPTH (args) - extra_levels;
601 /* If N is 1, just return the outermost set of template arguments. */
603 return TMPL_ARGS_LEVEL (args, 1);
605 /* If we're not removing anything, just return the arguments we were
607 gcc_assert (extra_levels >= 0);
608 if (extra_levels == 0)
611 /* Make a new set of arguments, not containing the inner arguments. */
612 new_args = make_tree_vec (n);
613 for (i = 1; i <= n; ++i)
614 SET_TMPL_ARGS_LEVEL (new_args, i,
615 TMPL_ARGS_LEVEL (args, i));
620 /* We've got a template header coming up; push to a new level for storing
624 begin_template_parm_list (void)
626 /* We use a non-tag-transparent scope here, which causes pushtag to
627 put tags in this scope, rather than in the enclosing class or
628 namespace scope. This is the right thing, since we want
629 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
630 global template class, push_template_decl handles putting the
631 TEMPLATE_DECL into top-level scope. For a nested template class,
634 template <class T> struct S1 {
635 template <class T> struct S2 {};
638 pushtag contains special code to call pushdecl_with_scope on the
639 TEMPLATE_DECL for S2. */
640 begin_scope (sk_template_parms, NULL);
641 ++processing_template_decl;
642 ++processing_template_parmlist;
643 note_template_header (0);
646 /* This routine is called when a specialization is declared. If it is
647 invalid to declare a specialization here, an error is reported and
648 false is returned, otherwise this routine will return true. */
651 check_specialization_scope (void)
653 tree scope = current_scope ();
657 An explicit specialization shall be declared in the namespace of
658 which the template is a member, or, for member templates, in the
659 namespace of which the enclosing class or enclosing class
660 template is a member. An explicit specialization of a member
661 function, member class or static data member of a class template
662 shall be declared in the namespace of which the class template
664 if (scope && TREE_CODE (scope) != NAMESPACE_DECL)
666 error ("explicit specialization in non-namespace scope %qD", scope);
672 In an explicit specialization declaration for a member of a class
673 template or a member template that appears in namespace scope,
674 the member template and some of its enclosing class templates may
675 remain unspecialized, except that the declaration shall not
676 explicitly specialize a class member template if its enclosing
677 class templates are not explicitly specialized as well. */
678 if (current_template_parms)
680 error ("enclosing class templates are not explicitly specialized");
687 /* We've just seen template <>. */
690 begin_specialization (void)
692 begin_scope (sk_template_spec, NULL);
693 note_template_header (1);
694 return check_specialization_scope ();
697 /* Called at then end of processing a declaration preceded by
701 end_specialization (void)
704 reset_specialization ();
707 /* Any template <>'s that we have seen thus far are not referring to a
708 function specialization. */
711 reset_specialization (void)
713 processing_specialization = 0;
714 template_header_count = 0;
717 /* We've just seen a template header. If SPECIALIZATION is nonzero,
718 it was of the form template <>. */
721 note_template_header (int specialization)
723 processing_specialization = specialization;
724 template_header_count++;
727 /* We're beginning an explicit instantiation. */
730 begin_explicit_instantiation (void)
732 gcc_assert (!processing_explicit_instantiation);
733 processing_explicit_instantiation = true;
738 end_explicit_instantiation (void)
740 gcc_assert (processing_explicit_instantiation);
741 processing_explicit_instantiation = false;
744 /* An explicit specialization or partial specialization TMPL is being
745 declared. Check that the namespace in which the specialization is
746 occurring is permissible. Returns false iff it is invalid to
747 specialize TMPL in the current namespace. */
750 check_specialization_namespace (tree tmpl)
752 tree tpl_ns = decl_namespace_context (tmpl);
756 An explicit specialization shall be declared in the namespace of
757 which the template is a member, or, for member templates, in the
758 namespace of which the enclosing class or enclosing class
759 template is a member. An explicit specialization of a member
760 function, member class or static data member of a class template
761 shall be declared in the namespace of which the class template is
763 if (current_scope() != DECL_CONTEXT (tmpl)
764 && !at_namespace_scope_p ())
766 error ("specialization of %qD must appear at namespace scope", tmpl);
769 if (is_associated_namespace (current_namespace, tpl_ns))
770 /* Same or super-using namespace. */
774 permerror (input_location, "specialization of %qD in different namespace", tmpl);
775 permerror (input_location, " from definition of %q+#D", tmpl);
780 /* SPEC is an explicit instantiation. Check that it is valid to
781 perform this explicit instantiation in the current namespace. */
784 check_explicit_instantiation_namespace (tree spec)
788 /* DR 275: An explicit instantiation shall appear in an enclosing
789 namespace of its template. */
790 ns = decl_namespace_context (spec);
791 if (!is_ancestor (current_namespace, ns))
792 permerror (input_location, "explicit instantiation of %qD in namespace %qD "
793 "(which does not enclose namespace %qD)",
794 spec, current_namespace, ns);
797 /* The TYPE is being declared. If it is a template type, that means it
798 is a partial specialization. Do appropriate error-checking. */
801 maybe_process_partial_specialization (tree type)
805 if (type == error_mark_node)
806 return error_mark_node;
808 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
810 error ("name of class shadows template template parameter %qD",
812 return error_mark_node;
815 context = TYPE_CONTEXT (type);
817 if ((CLASS_TYPE_P (type) && CLASSTYPE_USE_TEMPLATE (type))
818 /* Consider non-class instantiations of alias templates as
821 && TYPE_TEMPLATE_INFO (type)
822 && DECL_LANG_SPECIFIC (TYPE_NAME (type))
823 && DECL_USE_TEMPLATE (TYPE_NAME (type))))
825 /* This is for ordinary explicit specialization and partial
826 specialization of a template class such as:
828 template <> class C<int>;
832 template <class T> class C<T*>;
834 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
836 if (CLASS_TYPE_P (type)
837 && CLASSTYPE_IMPLICIT_INSTANTIATION (type)
838 && !COMPLETE_TYPE_P (type))
840 check_specialization_namespace (CLASSTYPE_TI_TEMPLATE (type));
841 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
842 if (processing_template_decl)
844 if (push_template_decl (TYPE_MAIN_DECL (type))
846 return error_mark_node;
849 else if (CLASS_TYPE_P (type)
850 && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
851 error ("specialization of %qT after instantiation", type);
853 if (DECL_ALIAS_TEMPLATE_P (TYPE_TI_TEMPLATE (type)))
855 error ("partial specialization of alias template %qD",
856 TYPE_TI_TEMPLATE (type));
857 return error_mark_node;
860 else if (CLASS_TYPE_P (type)
861 && !CLASSTYPE_USE_TEMPLATE (type)
862 && CLASSTYPE_TEMPLATE_INFO (type)
863 && context && CLASS_TYPE_P (context)
864 && CLASSTYPE_TEMPLATE_INFO (context))
866 /* This is for an explicit specialization of member class
867 template according to [temp.expl.spec/18]:
869 template <> template <class U> class C<int>::D;
871 The context `C<int>' must be an implicit instantiation.
872 Otherwise this is just a member class template declared
875 template <> class C<int> { template <class U> class D; };
876 template <> template <class U> class C<int>::D;
878 In the first case, `C<int>::D' is a specialization of `C<T>::D'
879 while in the second case, `C<int>::D' is a primary template
880 and `C<T>::D' may not exist. */
882 if (CLASSTYPE_IMPLICIT_INSTANTIATION (context)
883 && !COMPLETE_TYPE_P (type))
886 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
888 if (current_namespace
889 != decl_namespace_context (tmpl))
891 permerror (input_location, "specializing %q#T in different namespace", type);
892 permerror (input_location, " from definition of %q+#D", tmpl);
895 /* Check for invalid specialization after instantiation:
897 template <> template <> class C<int>::D<int>;
898 template <> template <class U> class C<int>::D; */
900 for (t = DECL_TEMPLATE_INSTANTIATIONS (tmpl);
901 t; t = TREE_CHAIN (t))
903 tree inst = TREE_VALUE (t);
904 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (inst))
906 /* We already have a full specialization of this partial
907 instantiation. Reassign it to the new member
908 specialization template. */
913 elt.tmpl = most_general_template (tmpl);
914 elt.args = CLASSTYPE_TI_ARGS (inst);
917 htab_remove_elt (type_specializations, &elt);
920 elt.args = INNERMOST_TEMPLATE_ARGS (elt.args);
922 slot = htab_find_slot (type_specializations, &elt, INSERT);
923 entry = ggc_alloc_spec_entry ();
927 else if (COMPLETE_OR_OPEN_TYPE_P (inst))
928 /* But if we've had an implicit instantiation, that's a
929 problem ([temp.expl.spec]/6). */
930 error ("specialization %qT after instantiation %qT",
934 /* Mark TYPE as a specialization. And as a result, we only
935 have one level of template argument for the innermost
937 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
938 CLASSTYPE_TI_ARGS (type)
939 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type));
942 else if (processing_specialization)
944 /* Someday C++0x may allow for enum template specialization. */
945 if (cxx_dialect > cxx98 && TREE_CODE (type) == ENUMERAL_TYPE
946 && CLASS_TYPE_P (context) && CLASSTYPE_USE_TEMPLATE (context))
947 pedwarn (input_location, OPT_pedantic, "template specialization "
948 "of %qD not allowed by ISO C++", type);
951 error ("explicit specialization of non-template %qT", type);
952 return error_mark_node;
959 /* Returns nonzero if we can optimize the retrieval of specializations
960 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
961 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
964 optimize_specialization_lookup_p (tree tmpl)
966 return (DECL_FUNCTION_TEMPLATE_P (tmpl)
967 && DECL_CLASS_SCOPE_P (tmpl)
968 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
970 && CLASS_TYPE_P (DECL_CONTEXT (tmpl))
971 /* The optimized lookup depends on the fact that the
972 template arguments for the member function template apply
973 purely to the containing class, which is not true if the
974 containing class is an explicit or partial
976 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (tmpl))
977 && !DECL_MEMBER_TEMPLATE_P (tmpl)
978 && !DECL_CONV_FN_P (tmpl)
979 /* It is possible to have a template that is not a member
980 template and is not a member of a template class:
982 template <typename T>
983 struct S { friend A::f(); };
985 Here, the friend function is a template, but the context does
986 not have template information. The optimized lookup relies
987 on having ARGS be the template arguments for both the class
988 and the function template. */
989 && !DECL_FRIEND_P (DECL_TEMPLATE_RESULT (tmpl)));
992 /* Retrieve the specialization (in the sense of [temp.spec] - a
993 specialization is either an instantiation or an explicit
994 specialization) of TMPL for the given template ARGS. If there is
995 no such specialization, return NULL_TREE. The ARGS are a vector of
996 arguments, or a vector of vectors of arguments, in the case of
997 templates with more than one level of parameters.
999 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
1000 then we search for a partial specialization matching ARGS. This
1001 parameter is ignored if TMPL is not a class template. */
1004 retrieve_specialization (tree tmpl, tree args, hashval_t hash)
1006 if (args == error_mark_node)
1009 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
1011 /* There should be as many levels of arguments as there are
1012 levels of parameters. */
1013 gcc_assert (TMPL_ARGS_DEPTH (args)
1014 == TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl)));
1016 if (optimize_specialization_lookup_p (tmpl))
1018 tree class_template;
1019 tree class_specialization;
1020 VEC(tree,gc) *methods;
1024 /* The template arguments actually apply to the containing
1025 class. Find the class specialization with those
1027 class_template = CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (tmpl));
1028 class_specialization
1029 = retrieve_specialization (class_template, args, 0);
1030 if (!class_specialization)
1032 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
1033 for the specialization. */
1034 idx = class_method_index_for_fn (class_specialization, tmpl);
1037 /* Iterate through the methods with the indicated name, looking
1038 for the one that has an instance of TMPL. */
1039 methods = CLASSTYPE_METHOD_VEC (class_specialization);
1040 for (fns = VEC_index (tree, methods, idx); fns; fns = OVL_NEXT (fns))
1042 tree fn = OVL_CURRENT (fns);
1043 if (DECL_TEMPLATE_INFO (fn) && DECL_TI_TEMPLATE (fn) == tmpl
1044 /* using-declarations can add base methods to the method vec,
1045 and we don't want those here. */
1046 && DECL_CONTEXT (fn) == class_specialization)
1055 htab_t specializations;
1059 elt.spec = NULL_TREE;
1061 if (DECL_CLASS_TEMPLATE_P (tmpl))
1062 specializations = type_specializations;
1064 specializations = decl_specializations;
1067 hash = hash_specialization (&elt);
1068 found = (spec_entry *) htab_find_with_hash (specializations, &elt, hash);
1076 /* Like retrieve_specialization, but for local declarations. */
1079 retrieve_local_specialization (tree tmpl)
1083 if (local_specializations == NULL)
1086 spec = (tree) htab_find_with_hash (local_specializations, tmpl,
1087 htab_hash_pointer (tmpl));
1088 return spec ? TREE_PURPOSE (spec) : NULL_TREE;
1091 /* Returns nonzero iff DECL is a specialization of TMPL. */
1094 is_specialization_of (tree decl, tree tmpl)
1098 if (TREE_CODE (decl) == FUNCTION_DECL)
1102 t = DECL_TEMPLATE_INFO (t) ? DECL_TI_TEMPLATE (t) : NULL_TREE)
1108 gcc_assert (TREE_CODE (decl) == TYPE_DECL);
1110 for (t = TREE_TYPE (decl);
1112 t = CLASSTYPE_USE_TEMPLATE (t)
1113 ? TREE_TYPE (CLASSTYPE_TI_TEMPLATE (t)) : NULL_TREE)
1114 if (same_type_ignoring_top_level_qualifiers_p (t, TREE_TYPE (tmpl)))
1121 /* Returns nonzero iff DECL is a specialization of friend declaration
1122 FRIEND_DECL according to [temp.friend]. */
1125 is_specialization_of_friend (tree decl, tree friend_decl)
1127 bool need_template = true;
1130 gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
1131 || TREE_CODE (decl) == TYPE_DECL);
1133 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1134 of a template class, we want to check if DECL is a specialization
1136 if (TREE_CODE (friend_decl) == FUNCTION_DECL
1137 && DECL_TEMPLATE_INFO (friend_decl)
1138 && !DECL_USE_TEMPLATE (friend_decl))
1140 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1141 friend_decl = DECL_TI_TEMPLATE (friend_decl);
1142 need_template = false;
1144 else if (TREE_CODE (friend_decl) == TEMPLATE_DECL
1145 && !PRIMARY_TEMPLATE_P (friend_decl))
1146 need_template = false;
1148 /* There is nothing to do if this is not a template friend. */
1149 if (TREE_CODE (friend_decl) != TEMPLATE_DECL)
1152 if (is_specialization_of (decl, friend_decl))
1156 A member of a class template may be declared to be a friend of a
1157 non-template class. In this case, the corresponding member of
1158 every specialization of the class template is a friend of the
1159 class granting friendship.
1161 For example, given a template friend declaration
1163 template <class T> friend void A<T>::f();
1165 the member function below is considered a friend
1167 template <> struct A<int> {
1171 For this type of template friend, TEMPLATE_DEPTH below will be
1172 nonzero. To determine if DECL is a friend of FRIEND, we first
1173 check if the enclosing class is a specialization of another. */
1175 template_depth = template_class_depth (CP_DECL_CONTEXT (friend_decl));
1177 && DECL_CLASS_SCOPE_P (decl)
1178 && is_specialization_of (TYPE_NAME (DECL_CONTEXT (decl)),
1179 CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (friend_decl))))
1181 /* Next, we check the members themselves. In order to handle
1182 a few tricky cases, such as when FRIEND_DECL's are
1184 template <class T> friend void A<T>::g(T t);
1185 template <class T> template <T t> friend void A<T>::h();
1189 void A<int>::g(int);
1190 template <int> void A<int>::h();
1192 we need to figure out ARGS, the template arguments from
1193 the context of DECL. This is required for template substitution
1194 of `T' in the function parameter of `g' and template parameter
1195 of `h' in the above examples. Here ARGS corresponds to `int'. */
1197 tree context = DECL_CONTEXT (decl);
1198 tree args = NULL_TREE;
1199 int current_depth = 0;
1201 while (current_depth < template_depth)
1203 if (CLASSTYPE_TEMPLATE_INFO (context))
1205 if (current_depth == 0)
1206 args = TYPE_TI_ARGS (context);
1208 args = add_to_template_args (TYPE_TI_ARGS (context), args);
1211 context = TYPE_CONTEXT (context);
1214 if (TREE_CODE (decl) == FUNCTION_DECL)
1219 tree friend_args_type;
1220 tree decl_args_type;
1222 /* Make sure that both DECL and FRIEND_DECL are templates or
1224 is_template = DECL_TEMPLATE_INFO (decl)
1225 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (decl));
1226 if (need_template ^ is_template)
1228 else if (is_template)
1230 /* If both are templates, check template parameter list. */
1232 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1234 if (!comp_template_parms
1235 (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (decl)),
1239 decl_type = TREE_TYPE (DECL_TI_TEMPLATE (decl));
1242 decl_type = TREE_TYPE (decl);
1244 friend_type = tsubst_function_type (TREE_TYPE (friend_decl), args,
1245 tf_none, NULL_TREE);
1246 if (friend_type == error_mark_node)
1249 /* Check if return types match. */
1250 if (!same_type_p (TREE_TYPE (decl_type), TREE_TYPE (friend_type)))
1253 /* Check if function parameter types match, ignoring the
1254 `this' parameter. */
1255 friend_args_type = TYPE_ARG_TYPES (friend_type);
1256 decl_args_type = TYPE_ARG_TYPES (decl_type);
1257 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (friend_decl))
1258 friend_args_type = TREE_CHAIN (friend_args_type);
1259 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1260 decl_args_type = TREE_CHAIN (decl_args_type);
1262 return compparms (decl_args_type, friend_args_type);
1266 /* DECL is a TYPE_DECL */
1268 tree decl_type = TREE_TYPE (decl);
1270 /* Make sure that both DECL and FRIEND_DECL are templates or
1273 = CLASSTYPE_TEMPLATE_INFO (decl_type)
1274 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (decl_type));
1276 if (need_template ^ is_template)
1278 else if (is_template)
1281 /* If both are templates, check the name of the two
1282 TEMPLATE_DECL's first because is_friend didn't. */
1283 if (DECL_NAME (CLASSTYPE_TI_TEMPLATE (decl_type))
1284 != DECL_NAME (friend_decl))
1287 /* Now check template parameter list. */
1289 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1291 return comp_template_parms
1292 (DECL_TEMPLATE_PARMS (CLASSTYPE_TI_TEMPLATE (decl_type)),
1296 return (DECL_NAME (decl)
1297 == DECL_NAME (friend_decl));
1303 /* Register the specialization SPEC as a specialization of TMPL with
1304 the indicated ARGS. IS_FRIEND indicates whether the specialization
1305 is actually just a friend declaration. Returns SPEC, or an
1306 equivalent prior declaration, if available. */
1309 register_specialization (tree spec, tree tmpl, tree args, bool is_friend,
1316 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL && DECL_P (spec));
1318 if (TREE_CODE (spec) == FUNCTION_DECL
1319 && uses_template_parms (DECL_TI_ARGS (spec)))
1320 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1321 register it; we want the corresponding TEMPLATE_DECL instead.
1322 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1323 the more obvious `uses_template_parms (spec)' to avoid problems
1324 with default function arguments. In particular, given
1325 something like this:
1327 template <class T> void f(T t1, T t = T())
1329 the default argument expression is not substituted for in an
1330 instantiation unless and until it is actually needed. */
1333 if (optimize_specialization_lookup_p (tmpl))
1334 /* We don't put these specializations in the hash table, but we might
1335 want to give an error about a mismatch. */
1336 fn = retrieve_specialization (tmpl, args, 0);
1344 hash = hash_specialization (&elt);
1347 htab_find_slot_with_hash (decl_specializations, &elt, hash, INSERT);
1349 fn = ((spec_entry *) *slot)->spec;
1354 /* We can sometimes try to re-register a specialization that we've
1355 already got. In particular, regenerate_decl_from_template calls
1356 duplicate_decls which will update the specialization list. But,
1357 we'll still get called again here anyhow. It's more convenient
1358 to simply allow this than to try to prevent it. */
1361 else if (fn && DECL_TEMPLATE_SPECIALIZATION (spec))
1363 if (DECL_TEMPLATE_INSTANTIATION (fn))
1365 if (DECL_ODR_USED (fn)
1366 || DECL_EXPLICIT_INSTANTIATION (fn))
1368 error ("specialization of %qD after instantiation",
1370 return error_mark_node;
1375 /* This situation should occur only if the first
1376 specialization is an implicit instantiation, the
1377 second is an explicit specialization, and the
1378 implicit instantiation has not yet been used. That
1379 situation can occur if we have implicitly
1380 instantiated a member function and then specialized
1383 We can also wind up here if a friend declaration that
1384 looked like an instantiation turns out to be a
1387 template <class T> void foo(T);
1388 class S { friend void foo<>(int) };
1389 template <> void foo(int);
1391 We transform the existing DECL in place so that any
1392 pointers to it become pointers to the updated
1395 If there was a definition for the template, but not
1396 for the specialization, we want this to look as if
1397 there were no definition, and vice versa. */
1398 DECL_INITIAL (fn) = NULL_TREE;
1399 duplicate_decls (spec, fn, is_friend);
1400 /* The call to duplicate_decls will have applied
1403 An explicit specialization of a function template
1404 is inline only if it is explicitly declared to be,
1405 and independently of whether its function template
1408 to the primary function; now copy the inline bits to
1409 the various clones. */
1410 FOR_EACH_CLONE (clone, fn)
1412 DECL_DECLARED_INLINE_P (clone)
1413 = DECL_DECLARED_INLINE_P (fn);
1414 DECL_SOURCE_LOCATION (clone)
1415 = DECL_SOURCE_LOCATION (fn);
1417 check_specialization_namespace (fn);
1422 else if (DECL_TEMPLATE_SPECIALIZATION (fn))
1424 if (!duplicate_decls (spec, fn, is_friend) && DECL_INITIAL (spec))
1425 /* Dup decl failed, but this is a new definition. Set the
1426 line number so any errors match this new
1428 DECL_SOURCE_LOCATION (fn) = DECL_SOURCE_LOCATION (spec);
1434 return duplicate_decls (spec, fn, is_friend);
1436 /* A specialization must be declared in the same namespace as the
1437 template it is specializing. */
1438 if (DECL_TEMPLATE_SPECIALIZATION (spec)
1439 && !check_specialization_namespace (tmpl))
1440 DECL_CONTEXT (spec) = DECL_CONTEXT (tmpl);
1442 if (slot != NULL /* !optimize_specialization_lookup_p (tmpl) */)
1444 spec_entry *entry = ggc_alloc_spec_entry ();
1445 gcc_assert (tmpl && args && spec);
1448 if (TREE_CODE (spec) == FUNCTION_DECL && DECL_NAMESPACE_SCOPE_P (spec)
1449 && PRIMARY_TEMPLATE_P (tmpl)
1450 && DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (tmpl)) == NULL_TREE)
1451 /* TMPL is a forward declaration of a template function; keep a list
1452 of all specializations in case we need to reassign them to a friend
1453 template later in tsubst_friend_function. */
1454 DECL_TEMPLATE_INSTANTIATIONS (tmpl)
1455 = tree_cons (args, spec, DECL_TEMPLATE_INSTANTIATIONS (tmpl));
1461 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1462 TMPL and ARGS members, ignores SPEC. */
1465 eq_specializations (const void *p1, const void *p2)
1467 const spec_entry *e1 = (const spec_entry *)p1;
1468 const spec_entry *e2 = (const spec_entry *)p2;
1470 return (e1->tmpl == e2->tmpl
1471 && comp_template_args (e1->args, e2->args));
1474 /* Returns a hash for a template TMPL and template arguments ARGS. */
1477 hash_tmpl_and_args (tree tmpl, tree args)
1479 hashval_t val = DECL_UID (tmpl);
1480 return iterative_hash_template_arg (args, val);
1483 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1487 hash_specialization (const void *p)
1489 const spec_entry *e = (const spec_entry *)p;
1490 return hash_tmpl_and_args (e->tmpl, e->args);
1493 /* Recursively calculate a hash value for a template argument ARG, for use
1494 in the hash tables of template specializations. */
1497 iterative_hash_template_arg (tree arg, hashval_t val)
1499 unsigned HOST_WIDE_INT i;
1500 enum tree_code code;
1503 if (arg == NULL_TREE)
1504 return iterative_hash_object (arg, val);
1509 if (TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
1510 /* We can get one of these when re-hashing a previous entry in the middle
1511 of substituting into a pack expansion. Just look through it. */
1512 arg = ARGUMENT_PACK_SELECT_FROM_PACK (arg);
1514 code = TREE_CODE (arg);
1515 tclass = TREE_CODE_CLASS (code);
1517 val = iterative_hash_object (code, val);
1524 case IDENTIFIER_NODE:
1525 return iterative_hash_object (IDENTIFIER_HASH_VALUE (arg), val);
1529 int i, len = TREE_VEC_LENGTH (arg);
1530 for (i = 0; i < len; ++i)
1531 val = iterative_hash_template_arg (TREE_VEC_ELT (arg, i), val);
1535 case TYPE_PACK_EXPANSION:
1536 case EXPR_PACK_EXPANSION:
1537 return iterative_hash_template_arg (PACK_EXPANSION_PATTERN (arg), val);
1539 case TYPE_ARGUMENT_PACK:
1540 case NONTYPE_ARGUMENT_PACK:
1541 return iterative_hash_template_arg (ARGUMENT_PACK_ARGS (arg), val);
1544 for (; arg; arg = TREE_CHAIN (arg))
1545 val = iterative_hash_template_arg (TREE_VALUE (arg), val);
1549 for (; arg; arg = OVL_NEXT (arg))
1550 val = iterative_hash_template_arg (OVL_CURRENT (arg), val);
1556 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg), i, field, value)
1558 val = iterative_hash_template_arg (field, val);
1559 val = iterative_hash_template_arg (value, val);
1565 if (!DECL_ARTIFICIAL (arg))
1567 val = iterative_hash_object (DECL_PARM_INDEX (arg), val);
1568 val = iterative_hash_object (DECL_PARM_LEVEL (arg), val);
1570 return iterative_hash_template_arg (TREE_TYPE (arg), val);
1573 return iterative_hash_template_arg (TARGET_EXPR_INITIAL (arg), val);
1576 val = iterative_hash_template_arg (PTRMEM_CST_CLASS (arg), val);
1577 return iterative_hash_template_arg (PTRMEM_CST_MEMBER (arg), val);
1579 case TEMPLATE_PARM_INDEX:
1580 val = iterative_hash_template_arg
1581 (TREE_TYPE (TEMPLATE_PARM_DECL (arg)), val);
1582 val = iterative_hash_object (TEMPLATE_PARM_LEVEL (arg), val);
1583 return iterative_hash_object (TEMPLATE_PARM_IDX (arg), val);
1586 val = iterative_hash_object (TRAIT_EXPR_KIND (arg), val);
1587 val = iterative_hash_template_arg (TRAIT_EXPR_TYPE1 (arg), val);
1588 return iterative_hash_template_arg (TRAIT_EXPR_TYPE2 (arg), val);
1591 val = iterative_hash_template_arg (BINFO_TYPE (BASELINK_BINFO (arg)),
1593 return iterative_hash_template_arg (DECL_NAME (get_first_fn (arg)),
1597 val = iterative_hash_template_arg (TREE_OPERAND (arg, 0), val);
1598 code = TREE_CODE (TREE_OPERAND (arg, 1));
1599 val = iterative_hash_object (code, val);
1600 return iterative_hash_template_arg (TREE_OPERAND (arg, 2), val);
1603 /* A lambda can't appear in a template arg, but don't crash on
1605 gcc_assert (seen_error ());
1609 case IMPLICIT_CONV_EXPR:
1610 case STATIC_CAST_EXPR:
1611 case REINTERPRET_CAST_EXPR:
1612 case CONST_CAST_EXPR:
1613 case DYNAMIC_CAST_EXPR:
1615 val = iterative_hash_template_arg (TREE_TYPE (arg), val);
1616 /* Now hash operands as usual. */
1626 if (TYPE_CANONICAL (arg))
1627 return iterative_hash_object (TYPE_HASH (TYPE_CANONICAL (arg)),
1629 else if (TREE_CODE (arg) == DECLTYPE_TYPE)
1630 return iterative_hash_template_arg (DECLTYPE_TYPE_EXPR (arg), val);
1631 /* Otherwise just compare the types during lookup. */
1634 case tcc_declaration:
1636 return iterative_hash_expr (arg, val);
1639 gcc_assert (IS_EXPR_CODE_CLASS (tclass));
1641 unsigned n = cp_tree_operand_length (arg);
1642 for (i = 0; i < n; ++i)
1643 val = iterative_hash_template_arg (TREE_OPERAND (arg, i), val);
1651 /* Unregister the specialization SPEC as a specialization of TMPL.
1652 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1653 if the SPEC was listed as a specialization of TMPL.
1655 Note that SPEC has been ggc_freed, so we can't look inside it. */
1658 reregister_specialization (tree spec, tree tinfo, tree new_spec)
1663 elt.tmpl = most_general_template (TI_TEMPLATE (tinfo));
1664 elt.args = TI_ARGS (tinfo);
1665 elt.spec = NULL_TREE;
1667 entry = (spec_entry *) htab_find (decl_specializations, &elt);
1670 gcc_assert (entry->spec == spec || entry->spec == new_spec);
1671 gcc_assert (new_spec != NULL_TREE);
1672 entry->spec = new_spec;
1679 /* Compare an entry in the local specializations hash table P1 (which
1680 is really a pointer to a TREE_LIST) with P2 (which is really a
1684 eq_local_specializations (const void *p1, const void *p2)
1686 return TREE_VALUE ((const_tree) p1) == (const_tree) p2;
1689 /* Hash P1, an entry in the local specializations table. */
1692 hash_local_specialization (const void* p1)
1694 return htab_hash_pointer (TREE_VALUE ((const_tree) p1));
1697 /* Like register_specialization, but for local declarations. We are
1698 registering SPEC, an instantiation of TMPL. */
1701 register_local_specialization (tree spec, tree tmpl)
1705 slot = htab_find_slot_with_hash (local_specializations, tmpl,
1706 htab_hash_pointer (tmpl), INSERT);
1707 *slot = build_tree_list (spec, tmpl);
1710 /* TYPE is a class type. Returns true if TYPE is an explicitly
1711 specialized class. */
1714 explicit_class_specialization_p (tree type)
1716 if (!CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
1718 return !uses_template_parms (CLASSTYPE_TI_ARGS (type));
1721 /* Print the list of functions at FNS, going through all the overloads
1722 for each element of the list. Alternatively, FNS can not be a
1723 TREE_LIST, in which case it will be printed together with all the
1726 MORE and *STR should respectively be FALSE and NULL when the function
1727 is called from the outside. They are used internally on recursive
1728 calls. print_candidates manages the two parameters and leaves NULL
1729 in *STR when it ends. */
1732 print_candidates_1 (tree fns, bool more, const char **str)
1735 char *spaces = NULL;
1737 for (fn = fns; fn; fn = OVL_NEXT (fn))
1738 if (TREE_CODE (fn) == TREE_LIST)
1740 for (fn2 = fn; fn2 != NULL_TREE; fn2 = TREE_CHAIN (fn2))
1741 print_candidates_1 (TREE_VALUE (fn2),
1742 TREE_CHAIN (fn2) || more, str);
1748 /* Pick the prefix string. */
1749 if (!more && !OVL_NEXT (fns))
1751 error ("candidate is: %+#D", OVL_CURRENT (fn));
1755 *str = _("candidates are:");
1756 spaces = get_spaces (*str);
1758 error ("%s %+#D", *str, OVL_CURRENT (fn));
1759 *str = spaces ? spaces : *str;
1769 /* Print the list of candidate FNS in an error message. FNS can also
1770 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1773 print_candidates (tree fns)
1775 const char *str = NULL;
1776 print_candidates_1 (fns, false, &str);
1777 gcc_assert (str == NULL);
1780 /* Returns the template (one of the functions given by TEMPLATE_ID)
1781 which can be specialized to match the indicated DECL with the
1782 explicit template args given in TEMPLATE_ID. The DECL may be
1783 NULL_TREE if none is available. In that case, the functions in
1784 TEMPLATE_ID are non-members.
1786 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1787 specialization of a member template.
1789 The TEMPLATE_COUNT is the number of references to qualifying
1790 template classes that appeared in the name of the function. See
1791 check_explicit_specialization for a more accurate description.
1793 TSK indicates what kind of template declaration (if any) is being
1794 declared. TSK_TEMPLATE indicates that the declaration given by
1795 DECL, though a FUNCTION_DECL, has template parameters, and is
1796 therefore a template function.
1798 The template args (those explicitly specified and those deduced)
1799 are output in a newly created vector *TARGS_OUT.
1801 If it is impossible to determine the result, an error message is
1802 issued. The error_mark_node is returned to indicate failure. */
1805 determine_specialization (tree template_id,
1808 int need_member_template,
1814 tree explicit_targs;
1815 tree candidates = NULL_TREE;
1816 /* A TREE_LIST of templates of which DECL may be a specialization.
1817 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1818 corresponding TREE_PURPOSE is the set of template arguments that,
1819 when used to instantiate the template, would produce a function
1820 with the signature of DECL. */
1821 tree templates = NULL_TREE;
1823 cp_binding_level *b;
1825 *targs_out = NULL_TREE;
1827 if (template_id == error_mark_node || decl == error_mark_node)
1828 return error_mark_node;
1830 fns = TREE_OPERAND (template_id, 0);
1831 explicit_targs = TREE_OPERAND (template_id, 1);
1833 if (fns == error_mark_node)
1834 return error_mark_node;
1836 /* Check for baselinks. */
1837 if (BASELINK_P (fns))
1838 fns = BASELINK_FUNCTIONS (fns);
1840 if (!is_overloaded_fn (fns))
1842 error ("%qD is not a function template", fns);
1843 return error_mark_node;
1846 /* Count the number of template headers specified for this
1849 for (b = current_binding_level;
1850 b->kind == sk_template_parms;
1854 for (; fns; fns = OVL_NEXT (fns))
1856 tree fn = OVL_CURRENT (fns);
1858 if (TREE_CODE (fn) == TEMPLATE_DECL)
1860 tree decl_arg_types;
1863 /* In case of explicit specialization, we need to check if
1864 the number of template headers appearing in the specialization
1865 is correct. This is usually done in check_explicit_specialization,
1866 but the check done there cannot be exhaustive when specializing
1867 member functions. Consider the following code:
1869 template <> void A<int>::f(int);
1870 template <> template <> void A<int>::f(int);
1872 Assuming that A<int> is not itself an explicit specialization
1873 already, the first line specializes "f" which is a non-template
1874 member function, whilst the second line specializes "f" which
1875 is a template member function. So both lines are syntactically
1876 correct, and check_explicit_specialization does not reject
1879 Here, we can do better, as we are matching the specialization
1880 against the declarations. We count the number of template
1881 headers, and we check if they match TEMPLATE_COUNT + 1
1882 (TEMPLATE_COUNT is the number of qualifying template classes,
1883 plus there must be another header for the member template
1886 Notice that if header_count is zero, this is not a
1887 specialization but rather a template instantiation, so there
1888 is no check we can perform here. */
1889 if (header_count && header_count != template_count + 1)
1892 /* Check that the number of template arguments at the
1893 innermost level for DECL is the same as for FN. */
1894 if (current_binding_level->kind == sk_template_parms
1895 && !current_binding_level->explicit_spec_p
1896 && (TREE_VEC_LENGTH (DECL_INNERMOST_TEMPLATE_PARMS (fn))
1897 != TREE_VEC_LENGTH (INNERMOST_TEMPLATE_PARMS
1898 (current_template_parms))))
1901 /* DECL might be a specialization of FN. */
1902 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1903 fn_arg_types = TYPE_ARG_TYPES (TREE_TYPE (fn));
1905 /* For a non-static member function, we need to make sure
1906 that the const qualification is the same. Since
1907 get_bindings does not try to merge the "this" parameter,
1908 we must do the comparison explicitly. */
1909 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
1910 && !same_type_p (TREE_VALUE (fn_arg_types),
1911 TREE_VALUE (decl_arg_types)))
1914 /* Skip the "this" parameter and, for constructors of
1915 classes with virtual bases, the VTT parameter. A
1916 full specialization of a constructor will have a VTT
1917 parameter, but a template never will. */
1919 = skip_artificial_parms_for (decl, decl_arg_types);
1921 = skip_artificial_parms_for (fn, fn_arg_types);
1923 /* Check that the number of function parameters matches.
1925 template <class T> void f(int i = 0);
1926 template <> void f<int>();
1927 The specialization f<int> is invalid but is not caught
1928 by get_bindings below. */
1929 if (list_length (fn_arg_types) != list_length (decl_arg_types))
1932 /* Function templates cannot be specializations; there are
1933 no partial specializations of functions. Therefore, if
1934 the type of DECL does not match FN, there is no
1936 if (tsk == tsk_template)
1938 if (compparms (fn_arg_types, decl_arg_types))
1939 candidates = tree_cons (NULL_TREE, fn, candidates);
1943 /* See whether this function might be a specialization of this
1945 targs = get_bindings (fn, decl, explicit_targs, /*check_ret=*/true);
1948 /* We cannot deduce template arguments that when used to
1949 specialize TMPL will produce DECL. */
1952 /* Save this template, and the arguments deduced. */
1953 templates = tree_cons (targs, fn, templates);
1955 else if (need_member_template)
1956 /* FN is an ordinary member function, and we need a
1957 specialization of a member template. */
1959 else if (TREE_CODE (fn) != FUNCTION_DECL)
1960 /* We can get IDENTIFIER_NODEs here in certain erroneous
1963 else if (!DECL_FUNCTION_MEMBER_P (fn))
1964 /* This is just an ordinary non-member function. Nothing can
1965 be a specialization of that. */
1967 else if (DECL_ARTIFICIAL (fn))
1968 /* Cannot specialize functions that are created implicitly. */
1972 tree decl_arg_types;
1974 /* This is an ordinary member function. However, since
1975 we're here, we can assume it's enclosing class is a
1976 template class. For example,
1978 template <typename T> struct S { void f(); };
1979 template <> void S<int>::f() {}
1981 Here, S<int>::f is a non-template, but S<int> is a
1982 template class. If FN has the same type as DECL, we
1983 might be in business. */
1985 if (!DECL_TEMPLATE_INFO (fn))
1986 /* Its enclosing class is an explicit specialization
1987 of a template class. This is not a candidate. */
1990 if (!same_type_p (TREE_TYPE (TREE_TYPE (decl)),
1991 TREE_TYPE (TREE_TYPE (fn))))
1992 /* The return types differ. */
1995 /* Adjust the type of DECL in case FN is a static member. */
1996 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1997 if (DECL_STATIC_FUNCTION_P (fn)
1998 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1999 decl_arg_types = TREE_CHAIN (decl_arg_types);
2001 if (compparms (TYPE_ARG_TYPES (TREE_TYPE (fn)),
2004 candidates = tree_cons (NULL_TREE, fn, candidates);
2008 if (templates && TREE_CHAIN (templates))
2014 It is possible for a specialization with a given function
2015 signature to be instantiated from more than one function
2016 template. In such cases, explicit specification of the
2017 template arguments must be used to uniquely identify the
2018 function template specialization being specialized.
2020 Note that here, there's no suggestion that we're supposed to
2021 determine which of the candidate templates is most
2022 specialized. However, we, also have:
2026 Partial ordering of overloaded function template
2027 declarations is used in the following contexts to select
2028 the function template to which a function template
2029 specialization refers:
2031 -- when an explicit specialization refers to a function
2034 So, we do use the partial ordering rules, at least for now.
2035 This extension can only serve to make invalid programs valid,
2036 so it's safe. And, there is strong anecdotal evidence that
2037 the committee intended the partial ordering rules to apply;
2038 the EDG front end has that behavior, and John Spicer claims
2039 that the committee simply forgot to delete the wording in
2040 [temp.expl.spec]. */
2041 tree tmpl = most_specialized_instantiation (templates);
2042 if (tmpl != error_mark_node)
2045 TREE_CHAIN (templates) = NULL_TREE;
2049 if (templates == NULL_TREE && candidates == NULL_TREE)
2051 error ("template-id %qD for %q+D does not match any template "
2052 "declaration", template_id, decl);
2053 if (header_count && header_count != template_count + 1)
2054 inform (input_location, "saw %d %<template<>%>, need %d for "
2055 "specializing a member function template",
2056 header_count, template_count + 1);
2057 return error_mark_node;
2059 else if ((templates && TREE_CHAIN (templates))
2060 || (candidates && TREE_CHAIN (candidates))
2061 || (templates && candidates))
2063 error ("ambiguous template specialization %qD for %q+D",
2065 candidates = chainon (candidates, templates);
2066 print_candidates (candidates);
2067 return error_mark_node;
2070 /* We have one, and exactly one, match. */
2073 tree fn = TREE_VALUE (candidates);
2074 *targs_out = copy_node (DECL_TI_ARGS (fn));
2075 /* DECL is a re-declaration or partial instantiation of a template
2077 if (TREE_CODE (fn) == TEMPLATE_DECL)
2079 /* It was a specialization of an ordinary member function in a
2081 return DECL_TI_TEMPLATE (fn);
2084 /* It was a specialization of a template. */
2085 targs = DECL_TI_ARGS (DECL_TEMPLATE_RESULT (TREE_VALUE (templates)));
2086 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (targs))
2088 *targs_out = copy_node (targs);
2089 SET_TMPL_ARGS_LEVEL (*targs_out,
2090 TMPL_ARGS_DEPTH (*targs_out),
2091 TREE_PURPOSE (templates));
2094 *targs_out = TREE_PURPOSE (templates);
2095 return TREE_VALUE (templates);
2098 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2099 but with the default argument values filled in from those in the
2103 copy_default_args_to_explicit_spec_1 (tree spec_types,
2106 tree new_spec_types;
2111 if (spec_types == void_list_node)
2112 return void_list_node;
2114 /* Substitute into the rest of the list. */
2116 copy_default_args_to_explicit_spec_1 (TREE_CHAIN (spec_types),
2117 TREE_CHAIN (tmpl_types));
2119 /* Add the default argument for this parameter. */
2120 return hash_tree_cons (TREE_PURPOSE (tmpl_types),
2121 TREE_VALUE (spec_types),
2125 /* DECL is an explicit specialization. Replicate default arguments
2126 from the template it specializes. (That way, code like:
2128 template <class T> void f(T = 3);
2129 template <> void f(double);
2132 works, as required.) An alternative approach would be to look up
2133 the correct default arguments at the call-site, but this approach
2134 is consistent with how implicit instantiations are handled. */
2137 copy_default_args_to_explicit_spec (tree decl)
2142 tree new_spec_types;
2146 tree object_type = NULL_TREE;
2147 tree in_charge = NULL_TREE;
2148 tree vtt = NULL_TREE;
2150 /* See if there's anything we need to do. */
2151 tmpl = DECL_TI_TEMPLATE (decl);
2152 tmpl_types = TYPE_ARG_TYPES (TREE_TYPE (DECL_TEMPLATE_RESULT (tmpl)));
2153 for (t = tmpl_types; t; t = TREE_CHAIN (t))
2154 if (TREE_PURPOSE (t))
2159 old_type = TREE_TYPE (decl);
2160 spec_types = TYPE_ARG_TYPES (old_type);
2162 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2164 /* Remove the this pointer, but remember the object's type for
2166 object_type = TREE_TYPE (TREE_VALUE (spec_types));
2167 spec_types = TREE_CHAIN (spec_types);
2168 tmpl_types = TREE_CHAIN (tmpl_types);
2170 if (DECL_HAS_IN_CHARGE_PARM_P (decl))
2172 /* DECL may contain more parameters than TMPL due to the extra
2173 in-charge parameter in constructors and destructors. */
2174 in_charge = spec_types;
2175 spec_types = TREE_CHAIN (spec_types);
2177 if (DECL_HAS_VTT_PARM_P (decl))
2180 spec_types = TREE_CHAIN (spec_types);
2184 /* Compute the merged default arguments. */
2186 copy_default_args_to_explicit_spec_1 (spec_types, tmpl_types);
2188 /* Compute the new FUNCTION_TYPE. */
2192 new_spec_types = hash_tree_cons (TREE_PURPOSE (vtt),
2197 /* Put the in-charge parameter back. */
2198 new_spec_types = hash_tree_cons (TREE_PURPOSE (in_charge),
2199 TREE_VALUE (in_charge),
2202 new_type = build_method_type_directly (object_type,
2203 TREE_TYPE (old_type),
2207 new_type = build_function_type (TREE_TYPE (old_type),
2209 new_type = cp_build_type_attribute_variant (new_type,
2210 TYPE_ATTRIBUTES (old_type));
2211 new_type = build_exception_variant (new_type,
2212 TYPE_RAISES_EXCEPTIONS (old_type));
2213 TREE_TYPE (decl) = new_type;
2216 /* Check to see if the function just declared, as indicated in
2217 DECLARATOR, and in DECL, is a specialization of a function
2218 template. We may also discover that the declaration is an explicit
2219 instantiation at this point.
2221 Returns DECL, or an equivalent declaration that should be used
2222 instead if all goes well. Issues an error message if something is
2223 amiss. Returns error_mark_node if the error is not easily
2226 FLAGS is a bitmask consisting of the following flags:
2228 2: The function has a definition.
2229 4: The function is a friend.
2231 The TEMPLATE_COUNT is the number of references to qualifying
2232 template classes that appeared in the name of the function. For
2235 template <class T> struct S { void f(); };
2238 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2239 classes are not counted in the TEMPLATE_COUNT, so that in
2241 template <class T> struct S {};
2242 template <> struct S<int> { void f(); }
2243 template <> void S<int>::f();
2245 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2246 invalid; there should be no template <>.)
2248 If the function is a specialization, it is marked as such via
2249 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2250 is set up correctly, and it is added to the list of specializations
2251 for that template. */
2254 check_explicit_specialization (tree declarator,
2259 int have_def = flags & 2;
2260 int is_friend = flags & 4;
2261 int specialization = 0;
2262 int explicit_instantiation = 0;
2263 int member_specialization = 0;
2264 tree ctype = DECL_CLASS_CONTEXT (decl);
2265 tree dname = DECL_NAME (decl);
2270 if (!processing_specialization)
2273 tsk = tsk_excessive_parms;
2276 tsk = current_tmpl_spec_kind (template_count);
2281 if (processing_specialization)
2284 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2286 else if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2289 /* This could be something like:
2291 template <class T> void f(T);
2292 class S { friend void f<>(int); } */
2296 /* This case handles bogus declarations like template <>
2297 template <class T> void f<int>(); */
2299 error ("template-id %qD in declaration of primary template",
2306 case tsk_invalid_member_spec:
2307 /* The error has already been reported in
2308 check_specialization_scope. */
2309 return error_mark_node;
2311 case tsk_invalid_expl_inst:
2312 error ("template parameter list used in explicit instantiation");
2318 error ("definition provided for explicit instantiation");
2320 explicit_instantiation = 1;
2323 case tsk_excessive_parms:
2324 case tsk_insufficient_parms:
2325 if (tsk == tsk_excessive_parms)
2326 error ("too many template parameter lists in declaration of %qD",
2328 else if (template_header_count)
2329 error("too few template parameter lists in declaration of %qD", decl);
2331 error("explicit specialization of %qD must be introduced by "
2332 "%<template <>%>", decl);
2336 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2338 member_specialization = 1;
2344 if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2346 /* This case handles bogus declarations like template <>
2347 template <class T> void f<int>(); */
2349 if (uses_template_parms (declarator))
2350 error ("function template partial specialization %qD "
2351 "is not allowed", declarator);
2353 error ("template-id %qD in declaration of primary template",
2358 if (ctype && CLASSTYPE_TEMPLATE_INSTANTIATION (ctype))
2359 /* This is a specialization of a member template, without
2360 specialization the containing class. Something like:
2362 template <class T> struct S {
2363 template <class U> void f (U);
2365 template <> template <class U> void S<int>::f(U) {}
2367 That's a specialization -- but of the entire template. */
2375 if (specialization || member_specialization)
2377 tree t = TYPE_ARG_TYPES (TREE_TYPE (decl));
2378 for (; t; t = TREE_CHAIN (t))
2379 if (TREE_PURPOSE (t))
2381 permerror (input_location,
2382 "default argument specified in explicit specialization");
2387 if (specialization || member_specialization || explicit_instantiation)
2389 tree tmpl = NULL_TREE;
2390 tree targs = NULL_TREE;
2392 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2393 if (TREE_CODE (declarator) != TEMPLATE_ID_EXPR)
2397 gcc_assert (TREE_CODE (declarator) == IDENTIFIER_NODE);
2402 /* If there is no class context, the explicit instantiation
2403 must be at namespace scope. */
2404 gcc_assert (DECL_NAMESPACE_SCOPE_P (decl));
2406 /* Find the namespace binding, using the declaration
2408 fns = lookup_qualified_name (CP_DECL_CONTEXT (decl), dname,
2410 if (fns == error_mark_node || !is_overloaded_fn (fns))
2412 error ("%qD is not a template function", dname);
2413 fns = error_mark_node;
2417 tree fn = OVL_CURRENT (fns);
2418 if (!is_associated_namespace (CP_DECL_CONTEXT (decl),
2419 CP_DECL_CONTEXT (fn)))
2420 error ("%qD is not declared in %qD",
2421 decl, current_namespace);
2425 declarator = lookup_template_function (fns, NULL_TREE);
2428 if (declarator == error_mark_node)
2429 return error_mark_node;
2431 if (ctype != NULL_TREE && TYPE_BEING_DEFINED (ctype))
2433 if (!explicit_instantiation)
2434 /* A specialization in class scope. This is invalid,
2435 but the error will already have been flagged by
2436 check_specialization_scope. */
2437 return error_mark_node;
2440 /* It's not valid to write an explicit instantiation in
2443 class C { template void f(); }
2445 This case is caught by the parser. However, on
2448 template class C { void f(); };
2450 (which is invalid) we can get here. The error will be
2457 else if (ctype != NULL_TREE
2458 && (TREE_CODE (TREE_OPERAND (declarator, 0)) ==
2461 /* Find the list of functions in ctype that have the same
2462 name as the declared function. */
2463 tree name = TREE_OPERAND (declarator, 0);
2464 tree fns = NULL_TREE;
2467 if (constructor_name_p (name, ctype))
2469 int is_constructor = DECL_CONSTRUCTOR_P (decl);
2471 if (is_constructor ? !TYPE_HAS_USER_CONSTRUCTOR (ctype)
2472 : !CLASSTYPE_DESTRUCTORS (ctype))
2474 /* From [temp.expl.spec]:
2476 If such an explicit specialization for the member
2477 of a class template names an implicitly-declared
2478 special member function (clause _special_), the
2479 program is ill-formed.
2481 Similar language is found in [temp.explicit]. */
2482 error ("specialization of implicitly-declared special member function");
2483 return error_mark_node;
2486 name = is_constructor ? ctor_identifier : dtor_identifier;
2489 if (!DECL_CONV_FN_P (decl))
2491 idx = lookup_fnfields_1 (ctype, name);
2493 fns = VEC_index (tree, CLASSTYPE_METHOD_VEC (ctype), idx);
2497 VEC(tree,gc) *methods;
2500 /* For a type-conversion operator, we cannot do a
2501 name-based lookup. We might be looking for `operator
2502 int' which will be a specialization of `operator T'.
2503 So, we find *all* the conversion operators, and then
2504 select from them. */
2507 methods = CLASSTYPE_METHOD_VEC (ctype);
2509 for (idx = CLASSTYPE_FIRST_CONVERSION_SLOT;
2510 VEC_iterate (tree, methods, idx, ovl);
2513 if (!DECL_CONV_FN_P (OVL_CURRENT (ovl)))
2514 /* There are no more conversion functions. */
2517 /* Glue all these conversion functions together
2518 with those we already have. */
2519 for (; ovl; ovl = OVL_NEXT (ovl))
2520 fns = ovl_cons (OVL_CURRENT (ovl), fns);
2524 if (fns == NULL_TREE)
2526 error ("no member function %qD declared in %qT", name, ctype);
2527 return error_mark_node;
2530 TREE_OPERAND (declarator, 0) = fns;
2533 /* Figure out what exactly is being specialized at this point.
2534 Note that for an explicit instantiation, even one for a
2535 member function, we cannot tell apriori whether the
2536 instantiation is for a member template, or just a member
2537 function of a template class. Even if a member template is
2538 being instantiated, the member template arguments may be
2539 elided if they can be deduced from the rest of the
2541 tmpl = determine_specialization (declarator, decl,
2543 member_specialization,
2547 if (!tmpl || tmpl == error_mark_node)
2548 /* We couldn't figure out what this declaration was
2550 return error_mark_node;
2553 tree gen_tmpl = most_general_template (tmpl);
2555 if (explicit_instantiation)
2557 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2558 is done by do_decl_instantiation later. */
2560 int arg_depth = TMPL_ARGS_DEPTH (targs);
2561 int parm_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
2563 if (arg_depth > parm_depth)
2565 /* If TMPL is not the most general template (for
2566 example, if TMPL is a friend template that is
2567 injected into namespace scope), then there will
2568 be too many levels of TARGS. Remove some of them
2573 new_targs = make_tree_vec (parm_depth);
2574 for (i = arg_depth - parm_depth; i < arg_depth; ++i)
2575 TREE_VEC_ELT (new_targs, i - (arg_depth - parm_depth))
2576 = TREE_VEC_ELT (targs, i);
2580 return instantiate_template (tmpl, targs, tf_error);
2583 /* If we thought that the DECL was a member function, but it
2584 turns out to be specializing a static member function,
2585 make DECL a static member function as well. */
2586 if (DECL_STATIC_FUNCTION_P (tmpl)
2587 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2588 revert_static_member_fn (decl);
2590 /* If this is a specialization of a member template of a
2591 template class, we want to return the TEMPLATE_DECL, not
2592 the specialization of it. */
2593 if (tsk == tsk_template)
2595 tree result = DECL_TEMPLATE_RESULT (tmpl);
2596 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
2597 DECL_INITIAL (result) = NULL_TREE;
2601 DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl);
2602 DECL_SOURCE_LOCATION (result)
2603 = DECL_SOURCE_LOCATION (decl);
2604 /* We want to use the argument list specified in the
2605 definition, not in the original declaration. */
2606 DECL_ARGUMENTS (result) = DECL_ARGUMENTS (decl);
2607 for (parm = DECL_ARGUMENTS (result); parm;
2608 parm = DECL_CHAIN (parm))
2609 DECL_CONTEXT (parm) = result;
2611 return register_specialization (tmpl, gen_tmpl, targs,
2615 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2616 DECL_TEMPLATE_INFO (decl) = build_template_info (tmpl, targs);
2618 /* Inherit default function arguments from the template
2619 DECL is specializing. */
2620 copy_default_args_to_explicit_spec (decl);
2622 /* This specialization has the same protection as the
2623 template it specializes. */
2624 TREE_PRIVATE (decl) = TREE_PRIVATE (gen_tmpl);
2625 TREE_PROTECTED (decl) = TREE_PROTECTED (gen_tmpl);
2627 /* 7.1.1-1 [dcl.stc]
2629 A storage-class-specifier shall not be specified in an
2630 explicit specialization...
2632 The parser rejects these, so unless action is taken here,
2633 explicit function specializations will always appear with
2636 The action recommended by the C++ CWG in response to C++
2637 defect report 605 is to make the storage class and linkage
2638 of the explicit specialization match the templated function:
2640 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2642 if (tsk == tsk_expl_spec && DECL_FUNCTION_TEMPLATE_P (gen_tmpl))
2644 tree tmpl_func = DECL_TEMPLATE_RESULT (gen_tmpl);
2645 gcc_assert (TREE_CODE (tmpl_func) == FUNCTION_DECL);
2647 /* This specialization has the same linkage and visibility as
2648 the function template it specializes. */
2649 TREE_PUBLIC (decl) = TREE_PUBLIC (tmpl_func);
2650 if (! TREE_PUBLIC (decl))
2652 DECL_INTERFACE_KNOWN (decl) = 1;
2653 DECL_NOT_REALLY_EXTERN (decl) = 1;
2655 DECL_THIS_STATIC (decl) = DECL_THIS_STATIC (tmpl_func);
2656 if (DECL_VISIBILITY_SPECIFIED (tmpl_func))
2658 DECL_VISIBILITY_SPECIFIED (decl) = 1;
2659 DECL_VISIBILITY (decl) = DECL_VISIBILITY (tmpl_func);
2663 /* If DECL is a friend declaration, declared using an
2664 unqualified name, the namespace associated with DECL may
2665 have been set incorrectly. For example, in:
2667 template <typename T> void f(T);
2669 struct S { friend void f<int>(int); }
2672 we will have set the DECL_CONTEXT for the friend
2673 declaration to N, rather than to the global namespace. */
2674 if (DECL_NAMESPACE_SCOPE_P (decl))
2675 DECL_CONTEXT (decl) = DECL_CONTEXT (tmpl);
2677 if (is_friend && !have_def)
2678 /* This is not really a declaration of a specialization.
2679 It's just the name of an instantiation. But, it's not
2680 a request for an instantiation, either. */
2681 SET_DECL_IMPLICIT_INSTANTIATION (decl);
2682 else if (DECL_CONSTRUCTOR_P (decl) || DECL_DESTRUCTOR_P (decl))
2683 /* This is indeed a specialization. In case of constructors
2684 and destructors, we need in-charge and not-in-charge
2685 versions in V3 ABI. */
2686 clone_function_decl (decl, /*update_method_vec_p=*/0);
2688 /* Register this specialization so that we can find it
2690 decl = register_specialization (decl, gen_tmpl, targs, is_friend, 0);
2697 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2698 parameters. These are represented in the same format used for
2699 DECL_TEMPLATE_PARMS. */
2702 comp_template_parms (const_tree parms1, const_tree parms2)
2707 if (parms1 == parms2)
2710 for (p1 = parms1, p2 = parms2;
2711 p1 != NULL_TREE && p2 != NULL_TREE;
2712 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2))
2714 tree t1 = TREE_VALUE (p1);
2715 tree t2 = TREE_VALUE (p2);
2718 gcc_assert (TREE_CODE (t1) == TREE_VEC);
2719 gcc_assert (TREE_CODE (t2) == TREE_VEC);
2721 if (TREE_VEC_LENGTH (t1) != TREE_VEC_LENGTH (t2))
2724 for (i = 0; i < TREE_VEC_LENGTH (t2); ++i)
2726 tree parm1 = TREE_VALUE (TREE_VEC_ELT (t1, i));
2727 tree parm2 = TREE_VALUE (TREE_VEC_ELT (t2, i));
2729 /* If either of the template parameters are invalid, assume
2730 they match for the sake of error recovery. */
2731 if (parm1 == error_mark_node || parm2 == error_mark_node)
2734 if (TREE_CODE (parm1) != TREE_CODE (parm2))
2737 if (TREE_CODE (parm1) == TEMPLATE_TYPE_PARM
2738 && (TEMPLATE_TYPE_PARAMETER_PACK (parm1)
2739 == TEMPLATE_TYPE_PARAMETER_PACK (parm2)))
2741 else if (!same_type_p (TREE_TYPE (parm1), TREE_TYPE (parm2)))
2746 if ((p1 != NULL_TREE) != (p2 != NULL_TREE))
2747 /* One set of parameters has more parameters lists than the
2754 /* Determine whether PARM is a parameter pack. */
2757 template_parameter_pack_p (const_tree parm)
2759 /* Determine if we have a non-type template parameter pack. */
2760 if (TREE_CODE (parm) == PARM_DECL)
2761 return (DECL_TEMPLATE_PARM_P (parm)
2762 && TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)));
2763 if (TREE_CODE (parm) == TEMPLATE_PARM_INDEX)
2764 return TEMPLATE_PARM_PARAMETER_PACK (parm);
2766 /* If this is a list of template parameters, we could get a
2767 TYPE_DECL or a TEMPLATE_DECL. */
2768 if (TREE_CODE (parm) == TYPE_DECL || TREE_CODE (parm) == TEMPLATE_DECL)
2769 parm = TREE_TYPE (parm);
2771 /* Otherwise it must be a type template parameter. */
2772 return ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
2773 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM)
2774 && TEMPLATE_TYPE_PARAMETER_PACK (parm));
2777 /* Determine if T is a function parameter pack. */
2780 function_parameter_pack_p (const_tree t)
2782 if (t && TREE_CODE (t) == PARM_DECL)
2783 return FUNCTION_PARAMETER_PACK_P (t);
2787 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2788 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2791 get_function_template_decl (const_tree primary_func_tmpl_inst)
2793 if (! primary_func_tmpl_inst
2794 || TREE_CODE (primary_func_tmpl_inst) != FUNCTION_DECL
2795 || ! primary_template_instantiation_p (primary_func_tmpl_inst))
2798 return DECL_TEMPLATE_RESULT (DECL_TI_TEMPLATE (primary_func_tmpl_inst));
2801 /* Return true iff the function parameter PARAM_DECL was expanded
2802 from the function parameter pack PACK. */
2805 function_parameter_expanded_from_pack_p (tree param_decl, tree pack)
2807 if (DECL_ARTIFICIAL (param_decl)
2808 || !function_parameter_pack_p (pack))
2811 /* The parameter pack and its pack arguments have the same
2813 return DECL_PARM_INDEX (pack) == DECL_PARM_INDEX (param_decl);
2816 /* Determine whether ARGS describes a variadic template args list,
2817 i.e., one that is terminated by a template argument pack. */
2820 template_args_variadic_p (tree args)
2825 if (args == NULL_TREE)
2828 args = INNERMOST_TEMPLATE_ARGS (args);
2829 nargs = TREE_VEC_LENGTH (args);
2834 last_parm = TREE_VEC_ELT (args, nargs - 1);
2836 return ARGUMENT_PACK_P (last_parm);
2839 /* Generate a new name for the parameter pack name NAME (an
2840 IDENTIFIER_NODE) that incorporates its */
2843 make_ith_pack_parameter_name (tree name, int i)
2845 /* Munge the name to include the parameter index. */
2846 #define NUMBUF_LEN 128
2847 char numbuf[NUMBUF_LEN];
2851 snprintf (numbuf, NUMBUF_LEN, "%i", i);
2852 newname_len = IDENTIFIER_LENGTH (name)
2853 + strlen (numbuf) + 2;
2854 newname = (char*)alloca (newname_len);
2855 snprintf (newname, newname_len,
2856 "%s#%i", IDENTIFIER_POINTER (name), i);
2857 return get_identifier (newname);
2860 /* Return true if T is a primary function, class or alias template
2864 primary_template_instantiation_p (const_tree t)
2869 if (TREE_CODE (t) == FUNCTION_DECL)
2870 return DECL_LANG_SPECIFIC (t)
2871 && DECL_TEMPLATE_INSTANTIATION (t)
2872 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (t));
2873 else if (CLASS_TYPE_P (t))
2874 return CLASSTYPE_TEMPLATE_INSTANTIATION (t)
2875 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (t));
2877 && TYPE_TEMPLATE_INFO (t)
2878 && PRIMARY_TEMPLATE_P (TYPE_TI_TEMPLATE (t))
2879 && DECL_TEMPLATE_INSTANTIATION (TYPE_NAME (t)))
2884 /* Return true if PARM is a template template parameter. */
2887 template_template_parameter_p (const_tree parm)
2889 return DECL_TEMPLATE_TEMPLATE_PARM_P (parm);
2892 /* Return the template parameters of T if T is a
2893 primary template instantiation, NULL otherwise. */
2896 get_primary_template_innermost_parameters (const_tree t)
2898 tree parms = NULL, template_info = NULL;
2900 if ((template_info = get_template_info (t))
2901 && primary_template_instantiation_p (t))
2902 parms = INNERMOST_TEMPLATE_PARMS
2903 (DECL_TEMPLATE_PARMS (TI_TEMPLATE (template_info)));
2908 /* Return the template parameters of the LEVELth level from the full list
2909 of template parameters PARMS. */
2912 get_template_parms_at_level (tree parms, int level)
2916 || TREE_CODE (parms) != TREE_LIST
2917 || level > TMPL_PARMS_DEPTH (parms))
2920 for (p = parms; p; p = TREE_CHAIN (p))
2921 if (TMPL_PARMS_DEPTH (p) == level)
2927 /* Returns the template arguments of T if T is a template instantiation,
2931 get_template_innermost_arguments (const_tree t)
2933 tree args = NULL, template_info = NULL;
2935 if ((template_info = get_template_info (t))
2936 && TI_ARGS (template_info))
2937 args = INNERMOST_TEMPLATE_ARGS (TI_ARGS (template_info));
2942 /* Return the argument pack elements of T if T is a template argument pack,
2946 get_template_argument_pack_elems (const_tree t)
2948 if (TREE_CODE (t) != TYPE_ARGUMENT_PACK
2949 && TREE_CODE (t) != NONTYPE_ARGUMENT_PACK)
2952 return ARGUMENT_PACK_ARGS (t);
2955 /* Structure used to track the progress of find_parameter_packs_r. */
2956 struct find_parameter_pack_data
2958 /* TREE_LIST that will contain all of the parameter packs found by
2960 tree* parameter_packs;
2962 /* Set of AST nodes that have been visited by the traversal. */
2963 struct pointer_set_t *visited;
2966 /* Identifies all of the argument packs that occur in a template
2967 argument and appends them to the TREE_LIST inside DATA, which is a
2968 find_parameter_pack_data structure. This is a subroutine of
2969 make_pack_expansion and uses_parameter_packs. */
2971 find_parameter_packs_r (tree *tp, int *walk_subtrees, void* data)
2974 struct find_parameter_pack_data* ppd =
2975 (struct find_parameter_pack_data*)data;
2976 bool parameter_pack_p = false;
2978 /* Identify whether this is a parameter pack or not. */
2979 switch (TREE_CODE (t))
2981 case TEMPLATE_PARM_INDEX:
2982 if (TEMPLATE_PARM_PARAMETER_PACK (t))
2983 parameter_pack_p = true;
2986 case TEMPLATE_TYPE_PARM:
2987 t = TYPE_MAIN_VARIANT (t);
2988 case TEMPLATE_TEMPLATE_PARM:
2989 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
2990 parameter_pack_p = true;
2994 if (FUNCTION_PARAMETER_PACK_P (t))
2996 /* We don't want to walk into the type of a PARM_DECL,
2997 because we don't want to see the type parameter pack. */
2999 parameter_pack_p = true;
3004 parameter_pack_p = true;
3007 /* Not a parameter pack. */
3011 if (parameter_pack_p)
3013 /* Add this parameter pack to the list. */
3014 *ppd->parameter_packs = tree_cons (NULL_TREE, t, *ppd->parameter_packs);
3018 cp_walk_tree (&TYPE_CONTEXT (t),
3019 &find_parameter_packs_r, ppd, ppd->visited);
3021 /* This switch statement will return immediately if we don't find a
3023 switch (TREE_CODE (t))
3025 case TEMPLATE_PARM_INDEX:
3028 case BOUND_TEMPLATE_TEMPLATE_PARM:
3029 /* Check the template itself. */
3030 cp_walk_tree (&TREE_TYPE (TYPE_TI_TEMPLATE (t)),
3031 &find_parameter_packs_r, ppd, ppd->visited);
3032 /* Check the template arguments. */
3033 cp_walk_tree (&TYPE_TI_ARGS (t), &find_parameter_packs_r, ppd,
3038 case TEMPLATE_TYPE_PARM:
3039 case TEMPLATE_TEMPLATE_PARM:
3046 if (TYPE_PTRMEMFUNC_P (t))
3052 if (TYPE_TEMPLATE_INFO (t))
3053 cp_walk_tree (&TI_ARGS (TYPE_TEMPLATE_INFO (t)),
3054 &find_parameter_packs_r, ppd, ppd->visited);
3061 cp_walk_tree (&TREE_TYPE (t),
3062 &find_parameter_packs_r, ppd, ppd->visited);
3066 cp_walk_tree (&TYPENAME_TYPE_FULLNAME (t), &find_parameter_packs_r,
3071 case TYPE_PACK_EXPANSION:
3072 case EXPR_PACK_EXPANSION:
3077 cp_walk_tree (&TYPE_MAX_VALUE (t), &find_parameter_packs_r,
3082 case IDENTIFIER_NODE:
3083 cp_walk_tree (&TREE_TYPE (t), &find_parameter_packs_r, ppd,
3095 /* Determines if the expression or type T uses any parameter packs. */
3097 uses_parameter_packs (tree t)
3099 tree parameter_packs = NULL_TREE;
3100 struct find_parameter_pack_data ppd;
3101 ppd.parameter_packs = ¶meter_packs;
3102 ppd.visited = pointer_set_create ();
3103 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
3104 pointer_set_destroy (ppd.visited);
3105 return parameter_packs != NULL_TREE;
3108 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3109 representation a base-class initializer into a parameter pack
3110 expansion. If all goes well, the resulting node will be an
3111 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3114 make_pack_expansion (tree arg)
3117 tree parameter_packs = NULL_TREE;
3118 bool for_types = false;
3119 struct find_parameter_pack_data ppd;
3121 if (!arg || arg == error_mark_node)
3124 if (TREE_CODE (arg) == TREE_LIST)
3126 /* The only time we will see a TREE_LIST here is for a base
3127 class initializer. In this case, the TREE_PURPOSE will be a
3128 _TYPE node (representing the base class expansion we're
3129 initializing) and the TREE_VALUE will be a TREE_LIST
3130 containing the initialization arguments.
3132 The resulting expansion looks somewhat different from most
3133 expansions. Rather than returning just one _EXPANSION, we
3134 return a TREE_LIST whose TREE_PURPOSE is a
3135 TYPE_PACK_EXPANSION containing the bases that will be
3136 initialized. The TREE_VALUE will be identical to the
3137 original TREE_VALUE, which is a list of arguments that will
3138 be passed to each base. We do not introduce any new pack
3139 expansion nodes into the TREE_VALUE (although it is possible
3140 that some already exist), because the TREE_PURPOSE and
3141 TREE_VALUE all need to be expanded together with the same
3142 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3143 resulting TREE_PURPOSE will mention the parameter packs in
3144 both the bases and the arguments to the bases. */
3147 tree parameter_packs = NULL_TREE;
3149 /* Determine which parameter packs will be used by the base
3151 ppd.visited = pointer_set_create ();
3152 ppd.parameter_packs = ¶meter_packs;
3153 cp_walk_tree (&TREE_PURPOSE (arg), &find_parameter_packs_r,
3156 if (parameter_packs == NULL_TREE)
3158 error ("base initializer expansion %<%T%> contains no parameter packs", arg);
3159 pointer_set_destroy (ppd.visited);
3160 return error_mark_node;
3163 if (TREE_VALUE (arg) != void_type_node)
3165 /* Collect the sets of parameter packs used in each of the
3166 initialization arguments. */
3167 for (value = TREE_VALUE (arg); value; value = TREE_CHAIN (value))
3169 /* Determine which parameter packs will be expanded in this
3171 cp_walk_tree (&TREE_VALUE (value), &find_parameter_packs_r,
3176 pointer_set_destroy (ppd.visited);
3178 /* Create the pack expansion type for the base type. */
3179 purpose = cxx_make_type (TYPE_PACK_EXPANSION);
3180 SET_PACK_EXPANSION_PATTERN (purpose, TREE_PURPOSE (arg));
3181 PACK_EXPANSION_PARAMETER_PACKS (purpose) = parameter_packs;
3183 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3184 they will rarely be compared to anything. */
3185 SET_TYPE_STRUCTURAL_EQUALITY (purpose);
3187 return tree_cons (purpose, TREE_VALUE (arg), NULL_TREE);
3190 if (TYPE_P (arg) || TREE_CODE (arg) == TEMPLATE_DECL)
3193 /* Build the PACK_EXPANSION_* node. */
3195 ? cxx_make_type (TYPE_PACK_EXPANSION)
3196 : make_node (EXPR_PACK_EXPANSION);
3197 SET_PACK_EXPANSION_PATTERN (result, arg);
3198 if (TREE_CODE (result) == EXPR_PACK_EXPANSION)
3200 /* Propagate type and const-expression information. */
3201 TREE_TYPE (result) = TREE_TYPE (arg);
3202 TREE_CONSTANT (result) = TREE_CONSTANT (arg);
3205 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3206 they will rarely be compared to anything. */
3207 SET_TYPE_STRUCTURAL_EQUALITY (result);
3209 /* Determine which parameter packs will be expanded. */
3210 ppd.parameter_packs = ¶meter_packs;
3211 ppd.visited = pointer_set_create ();
3212 cp_walk_tree (&arg, &find_parameter_packs_r, &ppd, ppd.visited);
3213 pointer_set_destroy (ppd.visited);
3215 /* Make sure we found some parameter packs. */
3216 if (parameter_packs == NULL_TREE)
3219 error ("expansion pattern %<%T%> contains no argument packs", arg);
3221 error ("expansion pattern %<%E%> contains no argument packs", arg);
3222 return error_mark_node;
3224 PACK_EXPANSION_PARAMETER_PACKS (result) = parameter_packs;
3229 /* Checks T for any "bare" parameter packs, which have not yet been
3230 expanded, and issues an error if any are found. This operation can
3231 only be done on full expressions or types (e.g., an expression
3232 statement, "if" condition, etc.), because we could have expressions like:
3234 foo(f(g(h(args)))...)
3236 where "args" is a parameter pack. check_for_bare_parameter_packs
3237 should not be called for the subexpressions args, h(args),
3238 g(h(args)), or f(g(h(args))), because we would produce erroneous
3241 Returns TRUE and emits an error if there were bare parameter packs,
3242 returns FALSE otherwise. */
3244 check_for_bare_parameter_packs (tree t)
3246 tree parameter_packs = NULL_TREE;
3247 struct find_parameter_pack_data ppd;
3249 if (!processing_template_decl || !t || t == error_mark_node)
3252 if (TREE_CODE (t) == TYPE_DECL)
3255 ppd.parameter_packs = ¶meter_packs;
3256 ppd.visited = pointer_set_create ();
3257 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
3258 pointer_set_destroy (ppd.visited);
3260 if (parameter_packs)
3262 error ("parameter packs not expanded with %<...%>:");
3263 while (parameter_packs)
3265 tree pack = TREE_VALUE (parameter_packs);
3266 tree name = NULL_TREE;
3268 if (TREE_CODE (pack) == TEMPLATE_TYPE_PARM
3269 || TREE_CODE (pack) == TEMPLATE_TEMPLATE_PARM)
3270 name = TYPE_NAME (pack);
3271 else if (TREE_CODE (pack) == TEMPLATE_PARM_INDEX)
3272 name = DECL_NAME (TEMPLATE_PARM_DECL (pack));
3274 name = DECL_NAME (pack);
3277 inform (input_location, " %qD", name);
3279 inform (input_location, " <anonymous>");
3281 parameter_packs = TREE_CHAIN (parameter_packs);
3290 /* Expand any parameter packs that occur in the template arguments in
3293 expand_template_argument_pack (tree args)
3295 tree result_args = NULL_TREE;
3296 int in_arg, out_arg = 0, nargs = args ? TREE_VEC_LENGTH (args) : 0;
3297 int num_result_args = -1;
3298 int non_default_args_count = -1;
3300 /* First, determine if we need to expand anything, and the number of
3301 slots we'll need. */
3302 for (in_arg = 0; in_arg < nargs; ++in_arg)
3304 tree arg = TREE_VEC_ELT (args, in_arg);
3305 if (arg == NULL_TREE)
3307 if (ARGUMENT_PACK_P (arg))
3309 int num_packed = TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg));
3310 if (num_result_args < 0)
3311 num_result_args = in_arg + num_packed;
3313 num_result_args += num_packed;
3317 if (num_result_args >= 0)
3322 /* If no expansion is necessary, we're done. */
3323 if (num_result_args < 0)
3326 /* Expand arguments. */
3327 result_args = make_tree_vec (num_result_args);
3328 if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (args))
3329 non_default_args_count =
3330 GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (args);
3331 for (in_arg = 0; in_arg < nargs; ++in_arg)
3333 tree arg = TREE_VEC_ELT (args, in_arg);
3334 if (ARGUMENT_PACK_P (arg))
3336 tree packed = ARGUMENT_PACK_ARGS (arg);
3337 int i, num_packed = TREE_VEC_LENGTH (packed);
3338 for (i = 0; i < num_packed; ++i, ++out_arg)
3339 TREE_VEC_ELT (result_args, out_arg) = TREE_VEC_ELT(packed, i);
3340 if (non_default_args_count > 0)
3341 non_default_args_count += num_packed;
3345 TREE_VEC_ELT (result_args, out_arg) = arg;
3349 if (non_default_args_count >= 0)
3350 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (result_args, non_default_args_count);
3354 /* Checks if DECL shadows a template parameter.
3356 [temp.local]: A template-parameter shall not be redeclared within its
3357 scope (including nested scopes).
3359 Emits an error and returns TRUE if the DECL shadows a parameter,
3360 returns FALSE otherwise. */
3363 check_template_shadow (tree decl)
3367 /* If we're not in a template, we can't possibly shadow a template
3369 if (!current_template_parms)
3372 /* Figure out what we're shadowing. */
3373 if (TREE_CODE (decl) == OVERLOAD)
3374 decl = OVL_CURRENT (decl);
3375 olddecl = innermost_non_namespace_value (DECL_NAME (decl));
3377 /* If there's no previous binding for this name, we're not shadowing
3378 anything, let alone a template parameter. */
3382 /* If we're not shadowing a template parameter, we're done. Note
3383 that OLDDECL might be an OVERLOAD (or perhaps even an
3384 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3386 if (!DECL_P (olddecl) || !DECL_TEMPLATE_PARM_P (olddecl))
3389 /* We check for decl != olddecl to avoid bogus errors for using a
3390 name inside a class. We check TPFI to avoid duplicate errors for
3391 inline member templates. */
3393 || TEMPLATE_PARMS_FOR_INLINE (current_template_parms))
3396 error ("declaration of %q+#D", decl);
3397 error (" shadows template parm %q+#D", olddecl);
3401 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3402 ORIG_LEVEL, DECL, and TYPE. NUM_SIBLINGS is the total number of
3403 template parameters. */
3406 build_template_parm_index (int index,
3413 tree t = make_node (TEMPLATE_PARM_INDEX);
3414 TEMPLATE_PARM_IDX (t) = index;
3415 TEMPLATE_PARM_LEVEL (t) = level;
3416 TEMPLATE_PARM_ORIG_LEVEL (t) = orig_level;
3417 TEMPLATE_PARM_NUM_SIBLINGS (t) = num_siblings;
3418 TEMPLATE_PARM_DECL (t) = decl;
3419 TREE_TYPE (t) = type;
3420 TREE_CONSTANT (t) = TREE_CONSTANT (decl);
3421 TREE_READONLY (t) = TREE_READONLY (decl);
3426 /* Find the canonical type parameter for the given template type
3427 parameter. Returns the canonical type parameter, which may be TYPE
3428 if no such parameter existed. */
3431 canonical_type_parameter (tree type)
3434 int idx = TEMPLATE_TYPE_IDX (type);
3435 if (!canonical_template_parms)
3436 canonical_template_parms = VEC_alloc (tree, gc, idx+1);
3438 while (VEC_length (tree, canonical_template_parms) <= (unsigned)idx)
3439 VEC_safe_push (tree, gc, canonical_template_parms, NULL_TREE);
3441 list = VEC_index (tree, canonical_template_parms, idx);
3442 while (list && !comptypes (type, TREE_VALUE (list), COMPARE_STRUCTURAL))
3443 list = TREE_CHAIN (list);
3446 return TREE_VALUE (list);
3449 VEC_replace(tree, canonical_template_parms, idx,
3450 tree_cons (NULL_TREE, type,
3451 VEC_index (tree, canonical_template_parms, idx)));
3456 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3457 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3458 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3459 new one is created. */
3462 reduce_template_parm_level (tree index, tree type, int levels, tree args,
3463 tsubst_flags_t complain)
3465 if (TEMPLATE_PARM_DESCENDANTS (index) == NULL_TREE
3466 || (TEMPLATE_PARM_LEVEL (TEMPLATE_PARM_DESCENDANTS (index))
3467 != TEMPLATE_PARM_LEVEL (index) - levels)
3468 || !same_type_p (type, TREE_TYPE (TEMPLATE_PARM_DESCENDANTS (index))))
3470 tree orig_decl = TEMPLATE_PARM_DECL (index);
3473 decl = build_decl (DECL_SOURCE_LOCATION (orig_decl),
3474 TREE_CODE (orig_decl), DECL_NAME (orig_decl), type);
3475 TREE_CONSTANT (decl) = TREE_CONSTANT (orig_decl);
3476 TREE_READONLY (decl) = TREE_READONLY (orig_decl);
3477 DECL_ARTIFICIAL (decl) = 1;
3478 SET_DECL_TEMPLATE_PARM_P (decl);
3480 t = build_template_parm_index (TEMPLATE_PARM_IDX (index),
3481 TEMPLATE_PARM_LEVEL (index) - levels,
3482 TEMPLATE_PARM_ORIG_LEVEL (index),
3483 TEMPLATE_PARM_NUM_SIBLINGS (index),
3485 TEMPLATE_PARM_DESCENDANTS (index) = t;
3486 TEMPLATE_PARM_PARAMETER_PACK (t)
3487 = TEMPLATE_PARM_PARAMETER_PACK (index);
3489 /* Template template parameters need this. */
3490 if (TREE_CODE (decl) == TEMPLATE_DECL)
3491 DECL_TEMPLATE_PARMS (decl) = tsubst_template_parms
3492 (DECL_TEMPLATE_PARMS (TEMPLATE_PARM_DECL (index)),
3496 return TEMPLATE_PARM_DESCENDANTS (index);
3499 /* Process information from new template parameter PARM and append it
3500 to the LIST being built. This new parameter is a non-type
3501 parameter iff IS_NON_TYPE is true. This new parameter is a
3502 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3503 is in PARM_LOC. NUM_TEMPLATE_PARMS is the size of the template
3504 parameter list PARM belongs to. This is used used to create a
3505 proper canonical type for the type of PARM that is to be created,
3506 iff PARM is a type. If the size is not known, this parameter shall
3510 process_template_parm (tree list, location_t parm_loc, tree parm,
3511 bool is_non_type, bool is_parameter_pack,
3512 unsigned num_template_parms)
3519 gcc_assert (TREE_CODE (parm) == TREE_LIST);
3520 defval = TREE_PURPOSE (parm);
3524 tree p = tree_last (list);
3526 if (p && TREE_VALUE (p) != error_mark_node)
3529 if (TREE_CODE (p) == TYPE_DECL || TREE_CODE (p) == TEMPLATE_DECL)
3530 idx = TEMPLATE_TYPE_IDX (TREE_TYPE (p));
3532 idx = TEMPLATE_PARM_IDX (DECL_INITIAL (p));
3542 parm = TREE_VALUE (parm);
3544 SET_DECL_TEMPLATE_PARM_P (parm);
3546 if (TREE_TYPE (parm) == error_mark_node)
3548 err_parm_list = build_tree_list (defval, parm);
3549 TREE_VALUE (err_parm_list) = error_mark_node;
3550 return chainon (list, err_parm_list);
3556 The top-level cv-qualifiers on the template-parameter are
3557 ignored when determining its type. */
3558 TREE_TYPE (parm) = TYPE_MAIN_VARIANT (TREE_TYPE (parm));
3559 if (invalid_nontype_parm_type_p (TREE_TYPE (parm), 1))
3561 err_parm_list = build_tree_list (defval, parm);
3562 TREE_VALUE (err_parm_list) = error_mark_node;
3563 return chainon (list, err_parm_list);
3566 if (uses_parameter_packs (TREE_TYPE (parm)) && !is_parameter_pack)
3568 /* This template parameter is not a parameter pack, but it
3569 should be. Complain about "bare" parameter packs. */
3570 check_for_bare_parameter_packs (TREE_TYPE (parm));
3572 /* Recover by calling this a parameter pack. */
3573 is_parameter_pack = true;
3577 /* A template parameter is not modifiable. */
3578 TREE_CONSTANT (parm) = 1;
3579 TREE_READONLY (parm) = 1;
3580 decl = build_decl (parm_loc,
3581 CONST_DECL, DECL_NAME (parm), TREE_TYPE (parm));
3582 TREE_CONSTANT (decl) = 1;
3583 TREE_READONLY (decl) = 1;
3584 DECL_INITIAL (parm) = DECL_INITIAL (decl)
3585 = build_template_parm_index (idx, processing_template_decl,
3586 processing_template_decl,
3588 decl, TREE_TYPE (parm));
3590 TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))
3591 = is_parameter_pack;
3596 parm = TREE_VALUE (TREE_VALUE (parm));
3598 if (parm && TREE_CODE (parm) == TEMPLATE_DECL)
3600 t = cxx_make_type (TEMPLATE_TEMPLATE_PARM);
3601 /* This is for distinguishing between real templates and template
3602 template parameters */
3603 TREE_TYPE (parm) = t;
3604 TREE_TYPE (DECL_TEMPLATE_RESULT (parm)) = t;
3609 t = cxx_make_type (TEMPLATE_TYPE_PARM);
3610 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3611 decl = build_decl (parm_loc,
3612 TYPE_DECL, parm, t);
3615 TYPE_NAME (t) = decl;
3616 TYPE_STUB_DECL (t) = decl;
3618 TEMPLATE_TYPE_PARM_INDEX (t)
3619 = build_template_parm_index (idx, processing_template_decl,
3620 processing_template_decl,
3622 decl, TREE_TYPE (parm));
3623 TEMPLATE_TYPE_PARAMETER_PACK (t) = is_parameter_pack;
3624 TYPE_CANONICAL (t) = canonical_type_parameter (t);
3626 DECL_ARTIFICIAL (decl) = 1;
3627 SET_DECL_TEMPLATE_PARM_P (decl);
3629 parm = build_tree_list (defval, parm);
3630 return chainon (list, parm);
3633 /* The end of a template parameter list has been reached. Process the
3634 tree list into a parameter vector, converting each parameter into a more
3635 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3639 end_template_parm_list (tree parms)
3643 tree saved_parmlist = make_tree_vec (list_length (parms));
3645 current_template_parms
3646 = tree_cons (size_int (processing_template_decl),
3647 saved_parmlist, current_template_parms);
3649 for (parm = parms, nparms = 0; parm; parm = next, nparms++)
3651 next = TREE_CHAIN (parm);
3652 TREE_VEC_ELT (saved_parmlist, nparms) = parm;
3653 TREE_CHAIN (parm) = NULL_TREE;
3656 --processing_template_parmlist;
3658 return saved_parmlist;
3661 /* Create a new type almost identical to TYPE but which has the
3662 following differences:
3664 1/ T has a new TEMPLATE_PARM_INDEX that carries the new number of
3665 template sibling parameters of T.
3667 2/ T has a new canonical type that matches the new number
3670 3/ From now on, T is going to be what lookups referring to the
3671 name of TYPE will return. No lookup should return TYPE anymore.
3673 NUM_PARMS is the new number of sibling parms TYPE belongs to.
3675 This is a subroutine of fixup_template_parms. */
3678 fixup_template_type_parm_type (tree type, int num_parms)
3680 tree orig_idx = TEMPLATE_TYPE_PARM_INDEX (type), idx;
3682 /* This is the decl which name is inserted into the symbol table for
3683 the template parm type. So whenever we lookup the type name, this
3684 is the DECL we get. */
3687 /* Do not fix up the type twice. */
3688 if (orig_idx && TEMPLATE_PARM_NUM_SIBLINGS (orig_idx) != 0)
3691 t = copy_type (type);
3692 decl = TYPE_NAME (t);
3694 TYPE_MAIN_VARIANT (t) = t;
3695 TYPE_NEXT_VARIANT (t)= NULL_TREE;
3696 TYPE_POINTER_TO (t) = 0;
3697 TYPE_REFERENCE_TO (t) = 0;
3699 idx = build_template_parm_index (TEMPLATE_PARM_IDX (orig_idx),
3700 TEMPLATE_PARM_LEVEL (orig_idx),
3701 TEMPLATE_PARM_ORIG_LEVEL (orig_idx),
3704 TEMPLATE_PARM_DESCENDANTS (idx) = TEMPLATE_PARM_DESCENDANTS (orig_idx);
3705 TEMPLATE_PARM_PARAMETER_PACK (idx) = TEMPLATE_PARM_PARAMETER_PACK (orig_idx);
3706 TEMPLATE_TYPE_PARM_INDEX (t) = idx;
3708 TYPE_STUB_DECL (t) = decl;
3709 TEMPLATE_TYPE_DECL (t) = decl;
3710 if (TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM)
3711 TREE_TYPE (DECL_TEMPLATE_RESULT (decl)) = t;
3713 /* Update the type associated to the type name stored in the symbol
3714 table. Now, whenever the type name is looked up, the resulting
3715 type is properly fixed up. */
3716 TREE_TYPE (decl) = t;
3718 TYPE_CANONICAL (t) = canonical_type_parameter (t);
3723 /* Create and return a new TEMPLATE_PARM_INDEX that is almost
3724 identical to I, but that is fixed up as to:
3726 1/ carry the number of sibling parms (NUM_PARMS) of the template
3727 parm represented by I.
3729 2/ replace all references to template parm types declared before I
3730 (in the same template parm list as I) by references to template
3731 parm types contained in ARGS. ARGS should contain the list of
3732 template parms that have been fixed up so far, in a form suitable
3733 to be passed to tsubst.
3735 This is a subroutine of fixup_template_parms. */
3738 fixup_template_parm_index (tree i, tree args, int num_parms)
3740 tree index, decl, type;
3743 || TREE_CODE (i) != TEMPLATE_PARM_INDEX
3744 /* Do not fix up the index twice. */
3745 || (TEMPLATE_PARM_NUM_SIBLINGS (i) != 0))
3748 decl = TEMPLATE_PARM_DECL (i);
3749 type = TREE_TYPE (decl);
3751 index = build_template_parm_index (TEMPLATE_PARM_IDX (i),
3752 TEMPLATE_PARM_LEVEL (i),
3753 TEMPLATE_PARM_ORIG_LEVEL (i),
3757 TEMPLATE_PARM_DESCENDANTS (index) = TEMPLATE_PARM_DESCENDANTS (i);
3758 TEMPLATE_PARM_PARAMETER_PACK (index) = TEMPLATE_PARM_PARAMETER_PACK (i);
3760 type = tsubst (type, args, tf_none, NULL_TREE);
3762 TREE_TYPE (decl) = type;
3763 TREE_TYPE (index) = type;
3769 This is a subroutine of fixup_template_parms.
3771 It computes the canonical type of the type of the template
3772 parameter PARM_DESC and update all references to that type so that
3773 they use the newly computed canonical type. No access check is
3774 performed during the fixup. PARM_DESC is a TREE_LIST which
3775 TREE_VALUE is the template parameter and its TREE_PURPOSE is the
3776 default argument of the template parm if any. IDX is the index of
3777 the template parameter, starting at 0. NUM_PARMS is the number of
3778 template parameters in the set PARM_DESC belongs to. ARGLIST is a
3779 TREE_VEC containing the full set of template parameters in a form
3780 suitable to be passed to substs functions as their ARGS
3781 argument. This is what current_template_args returns for a given
3782 template. The innermost vector of args in ARGLIST is the set of
3783 template parms that have been fixed up so far. This function adds
3784 the fixed up parameter into that vector. */
3787 fixup_template_parm (tree parm_desc,
3792 tree parm = TREE_VALUE (parm_desc);
3793 tree fixedup_args = INNERMOST_TEMPLATE_ARGS (arglist);
3795 push_deferring_access_checks (dk_no_check);
3797 if (TREE_CODE (parm) == TYPE_DECL)
3799 /* PARM is a template type parameter. Fix up its type, add
3800 the fixed-up template parm to the vector of fixed-up
3801 template parms so far, and substitute the fixed-up
3802 template parms into the default argument of this
3805 fixup_template_type_parm_type (TREE_TYPE (parm), num_parms);
3806 TREE_TYPE (parm) = t;
3808 TREE_VEC_ELT (fixedup_args, idx) = template_parm_to_arg (parm_desc);
3810 else if (TREE_CODE (parm) == TEMPLATE_DECL)
3812 /* PARM is a template template parameter. This is going to
3814 tree tparms, targs, innermost_args, t;
3817 /* First, fix up the parms of the template template parm
3818 because the parms are involved in defining the new canonical
3819 type of the template template parm. */
3821 /* So we need to substitute the template parm types that have
3822 been fixed up so far into the template parms of this template
3823 template parm. E.g, consider this:
3825 template<class T, template<T u> class TT> class S;
3827 In this case we want to substitute T into the
3828 template parameters of TT.
3830 So let's walk the template parms of PARM here, and
3831 tsubst ARGLIST into into each of the template
3834 /* For this substitution we need to build the full set of
3835 template parameters and use that as arguments for the
3836 tsubsting function. */
3837 tparms = INNERMOST_TEMPLATE_PARMS (DECL_TEMPLATE_PARMS (parm));
3839 /* This will contain the innermost parms of PARM into which
3840 we have substituted so far. */
3841 innermost_args = make_tree_vec (TREE_VEC_LENGTH (tparms));
3842 targs = add_to_template_args (arglist, innermost_args);
3843 for (j = 0; j < TREE_VEC_LENGTH (tparms); ++j)
3847 parameter = TREE_VEC_ELT (tparms, j);
3849 /* INNERMOST_ARGS needs to have at least the same number
3850 of elements as the index PARAMETER, ortherwise
3851 tsubsting into PARAMETER will result in partially
3852 instantiating it, reducing its tempate parm
3853 level. Let's tactically fill INNERMOST_ARGS for that
3855 TREE_VEC_ELT (innermost_args, j) =
3856 template_parm_to_arg (parameter);
3858 fixup_template_parm (parameter, j,
3859 TREE_VEC_LENGTH (tparms),
3863 /* Now fix up the type of the template template parm. */
3865 t = fixup_template_type_parm_type (TREE_TYPE (parm), num_parms);
3866 TREE_TYPE (parm) = t;
3868 TREE_VEC_ELT (fixedup_args, idx) =
3869 template_parm_to_arg (parm_desc);
3871 else if (TREE_CODE (parm) == PARM_DECL)
3873 /* PARM is a non-type template parameter. We need to:
3875 * Fix up its TEMPLATE_PARM_INDEX to make it carry the
3876 proper number of sibling parameters.
3878 * Make lookups of the template parameter return a reference
3879 to the fixed-up index. No lookup should return references
3880 to the former index anymore.
3882 * Substitute the template parms that got fixed up so far
3884 * into the type of PARM. */
3886 tree index = DECL_INITIAL (parm);
3888 /* PUSHED_DECL is the decl added to the symbol table with
3889 the name of the parameter. E,g:
3891 template<class T, T u> //#0
3892 auto my_function(T t) -> decltype(u); //#1
3894 Here, when looking up u at //#1, we get the decl of u
3895 resulting from the declaration in #0. This is what
3896 PUSHED_DECL is. We need to replace the reference to the
3897 old TEMPLATE_PARM_INDEX carried by PUSHED_DECL by the
3898 fixed-up TEMPLATE_PARM_INDEX. */
3899 tree pushed_decl = TEMPLATE_PARM_DECL (index);
3901 /* Let's fix up the TEMPLATE_PARM_INDEX then. Note that we must
3902 fixup the type of PUSHED_DECL as well and luckily
3903 fixup_template_parm_index does it for us too. */
3904 tree fixed_up_index =
3905 fixup_template_parm_index (index, arglist, num_parms);
3907 DECL_INITIAL (pushed_decl) = DECL_INITIAL (parm) = fixed_up_index;
3909 /* Add this fixed up PARM to the template parms we've fixed
3910 up so far and use that to substitute the fixed-up
3911 template parms into the type of PARM. */
3912 TREE_VEC_ELT (fixedup_args, idx) =
3913 template_parm_to_arg (parm_desc);
3914 TREE_TYPE (parm) = tsubst (TREE_TYPE (parm), arglist,
3915 tf_none, NULL_TREE);
3918 TREE_PURPOSE (parm_desc) =
3919 tsubst_template_arg (TREE_PURPOSE (parm_desc),
3920 arglist, tf_none, parm);
3922 pop_deferring_access_checks ();
3925 /* Walk the current template parms and properly compute the canonical
3926 types of the dependent types created during
3927 cp_parser_template_parameter_list. */
3930 fixup_template_parms (void)
3937 parameter_vec = INNERMOST_TEMPLATE_PARMS (current_template_parms);
3938 if (parameter_vec == NULL_TREE)
3941 num_parms = TREE_VEC_LENGTH (parameter_vec);
3943 /* This vector contains the current innermost template parms that
3944 have been fixed up so far. The form of FIXEDUP_ARGS is suitable
3945 to be passed to tsubst* functions as their ARGS argument. */
3946 fixedup_args = make_tree_vec (num_parms);
3948 /* This vector contains the full set of template parms in a form
3949 suitable to be passed to substs functions as their ARGS
3951 arglist = current_template_args ();
3952 arglist = add_outermost_template_args (arglist, fixedup_args);
3954 /* Let's do the proper fixup now. */
3955 for (i = 0; i < num_parms; ++i)
3956 fixup_template_parm (TREE_VEC_ELT (parameter_vec, i),
3957 i, num_parms, arglist);
3960 /* end_template_decl is called after a template declaration is seen. */
3963 end_template_decl (void)
3965 reset_specialization ();
3967 if (! processing_template_decl)
3970 /* This matches the pushlevel in begin_template_parm_list. */
3973 --processing_template_decl;
3974 current_template_parms = TREE_CHAIN (current_template_parms);
3977 /* Takes a TREE_LIST representing a template parameter and convert it
3978 into an argument suitable to be passed to the type substitution
3979 functions. Note that If the TREE_LIST contains an error_mark
3980 node, the returned argument is error_mark_node. */
3983 template_parm_to_arg (tree t)
3987 || TREE_CODE (t) != TREE_LIST)
3990 if (error_operand_p (TREE_VALUE (t)))
3991 return error_mark_node;
3995 if (TREE_CODE (t) == TYPE_DECL
3996 || TREE_CODE (t) == TEMPLATE_DECL)
4000 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
4002 /* Turn this argument into a TYPE_ARGUMENT_PACK
4003 with a single element, which expands T. */
4004 tree vec = make_tree_vec (1);
4005 #ifdef ENABLE_CHECKING
4006 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
4007 (vec, TREE_VEC_LENGTH (vec));
4009 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
4011 t = cxx_make_type (TYPE_ARGUMENT_PACK);
4012 SET_ARGUMENT_PACK_ARGS (t, vec);
4017 t = DECL_INITIAL (t);
4019 if (TEMPLATE_PARM_PARAMETER_PACK (t))
4021 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
4022 with a single element, which expands T. */
4023 tree vec = make_tree_vec (1);
4024 tree type = TREE_TYPE (TEMPLATE_PARM_DECL (t));
4025 #ifdef ENABLE_CHECKING
4026 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
4027 (vec, TREE_VEC_LENGTH (vec));
4029 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
4031 t = make_node (NONTYPE_ARGUMENT_PACK);
4032 SET_ARGUMENT_PACK_ARGS (t, vec);
4033 TREE_TYPE (t) = type;
4039 /* This function returns TRUE if PARM_PACK is a template parameter
4040 pack and if ARG_PACK is what template_parm_to_arg returned when
4041 passed PARM_PACK. */
4044 arg_from_parm_pack_p (tree arg_pack, tree parm_pack)
4046 /* For clarity in the comments below let's use the representation
4047 argument_pack<elements>' to denote an argument pack and its
4050 In the 'if' block below, we want to detect cases where
4051 ARG_PACK is argument_pack<PARM_PACK...>. I.e, we want to
4052 check if ARG_PACK is an argument pack which sole element is
4053 the expansion of PARM_PACK. That argument pack is typically
4054 created by template_parm_to_arg when passed a parameter
4058 && TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack)) == 1
4059 && PACK_EXPANSION_P (TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0)))
4061 tree expansion = TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0);
4062 tree pattern = PACK_EXPANSION_PATTERN (expansion);
4063 /* So we have an argument_pack<P...>. We want to test if P
4064 is actually PARM_PACK. We will not use cp_tree_equal to
4065 test P and PARM_PACK because during type fixup (by
4066 fixup_template_parm) P can be a pre-fixup version of a
4067 type and PARM_PACK be its post-fixup version.
4068 cp_tree_equal would consider them as different even
4069 though we would want to consider them compatible for our
4070 precise purpose here.
4072 Thus we are going to consider that P and PARM_PACK are
4073 compatible if they have the same DECL. */
4074 if ((/* If ARG_PACK is a type parameter pack named by the
4075 same DECL as parm_pack ... */
4077 && TYPE_P (parm_pack)
4078 && TYPE_NAME (pattern) == TYPE_NAME (parm_pack))
4079 /* ... or if PARM_PACK is a non-type parameter named by the
4080 same DECL as ARG_PACK. Note that PARM_PACK being a
4081 non-type parameter means it's either a PARM_DECL or a
4082 TEMPLATE_PARM_INDEX. */
4083 || (TREE_CODE (pattern) == TEMPLATE_PARM_INDEX
4084 && ((TREE_CODE (parm_pack) == PARM_DECL
4085 && (TEMPLATE_PARM_DECL (pattern)
4086 == TEMPLATE_PARM_DECL (DECL_INITIAL (parm_pack))))
4087 || (TREE_CODE (parm_pack) == TEMPLATE_PARM_INDEX
4088 && (TEMPLATE_PARM_DECL (pattern)
4089 == TEMPLATE_PARM_DECL (parm_pack))))))
4090 && template_parameter_pack_p (pattern))
4096 /* Within the declaration of a template, return all levels of template
4097 parameters that apply. The template parameters are represented as
4098 a TREE_VEC, in the form documented in cp-tree.h for template
4102 current_template_args (void)
4105 tree args = NULL_TREE;
4106 int length = TMPL_PARMS_DEPTH (current_template_parms);
4109 /* If there is only one level of template parameters, we do not
4110 create a TREE_VEC of TREE_VECs. Instead, we return a single
4111 TREE_VEC containing the arguments. */
4113 args = make_tree_vec (length);
4115 for (header = current_template_parms; header; header = TREE_CHAIN (header))
4117 tree a = copy_node (TREE_VALUE (header));
4120 TREE_TYPE (a) = NULL_TREE;
4121 for (i = TREE_VEC_LENGTH (a) - 1; i >= 0; --i)
4122 TREE_VEC_ELT (a, i) = template_parm_to_arg (TREE_VEC_ELT (a, i));
4124 #ifdef ENABLE_CHECKING
4125 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (a, TREE_VEC_LENGTH (a));
4129 TREE_VEC_ELT (args, --l) = a;
4134 if (length > 1 && TREE_VEC_ELT (args, 0) == NULL_TREE)
4135 /* This can happen for template parms of a template template
4138 template<template<class T, class U> class TT> struct S;
4140 Consider the level of the parms of TT; T and U both have
4141 level 2; TT has no template parm of level 1. So in this case
4142 the first element of full_template_args is NULL_TREE. If we
4143 leave it like this TMPL_ARG_DEPTH on args returns 1 instead
4144 of 2. This will make tsubst wrongly consider that T and U
4145 have level 1. Instead, let's create a dummy vector as the
4146 first element of full_template_args so that TMPL_ARG_DEPTH
4147 returns the correct depth for args. */
4148 TREE_VEC_ELT (args, 0) = make_tree_vec (1);
4152 /* Update the declared TYPE by doing any lookups which were thought to be
4153 dependent, but are not now that we know the SCOPE of the declarator. */
4156 maybe_update_decl_type (tree orig_type, tree scope)
4158 tree type = orig_type;
4160 if (type == NULL_TREE)
4163 if (TREE_CODE (orig_type) == TYPE_DECL)
4164 type = TREE_TYPE (type);
4166 if (scope && TYPE_P (scope) && dependent_type_p (scope)
4167 && dependent_type_p (type)
4168 /* Don't bother building up the args in this case. */
4169 && TREE_CODE (type) != TEMPLATE_TYPE_PARM)
4171 /* tsubst in the args corresponding to the template parameters,
4172 including auto if present. Most things will be unchanged, but
4173 make_typename_type and tsubst_qualified_id will resolve
4174 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4175 tree args = current_template_args ();
4176 tree auto_node = type_uses_auto (type);
4180 tree auto_vec = make_tree_vec (1);
4181 TREE_VEC_ELT (auto_vec, 0) = auto_node;
4182 args = add_to_template_args (args, auto_vec);
4184 pushed = push_scope (scope);
4185 type = tsubst (type, args, tf_warning_or_error, NULL_TREE);
4190 if (type == error_mark_node)
4193 if (TREE_CODE (orig_type) == TYPE_DECL)
4195 if (same_type_p (type, TREE_TYPE (orig_type)))
4198 type = TYPE_NAME (type);
4203 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4204 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
4205 a member template. Used by push_template_decl below. */
4208 build_template_decl (tree decl, tree parms, bool member_template_p)
4210 tree tmpl = build_lang_decl (TEMPLATE_DECL, DECL_NAME (decl), NULL_TREE);
4211 DECL_TEMPLATE_PARMS (tmpl) = parms;
4212 DECL_CONTEXT (tmpl) = DECL_CONTEXT (decl);
4213 DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl);
4214 DECL_MEMBER_TEMPLATE_P (tmpl) = member_template_p;
4219 struct template_parm_data
4221 /* The level of the template parameters we are currently
4225 /* The index of the specialization argument we are currently
4229 /* An array whose size is the number of template parameters. The
4230 elements are nonzero if the parameter has been used in any one
4231 of the arguments processed so far. */
4234 /* An array whose size is the number of template arguments. The
4235 elements are nonzero if the argument makes use of template
4236 parameters of this level. */
4237 int* arg_uses_template_parms;
4240 /* Subroutine of push_template_decl used to see if each template
4241 parameter in a partial specialization is used in the explicit
4242 argument list. If T is of the LEVEL given in DATA (which is
4243 treated as a template_parm_data*), then DATA->PARMS is marked
4247 mark_template_parm (tree t, void* data)
4251 struct template_parm_data* tpd = (struct template_parm_data*) data;
4253 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
4255 level = TEMPLATE_PARM_LEVEL (t);
4256 idx = TEMPLATE_PARM_IDX (t);
4260 level = TEMPLATE_TYPE_LEVEL (t);
4261 idx = TEMPLATE_TYPE_IDX (t);
4264 if (level == tpd->level)
4266 tpd->parms[idx] = 1;
4267 tpd->arg_uses_template_parms[tpd->current_arg] = 1;
4270 /* Return zero so that for_each_template_parm will continue the
4271 traversal of the tree; we want to mark *every* template parm. */
4275 /* Process the partial specialization DECL. */
4278 process_partial_specialization (tree decl)
4280 tree type = TREE_TYPE (decl);
4281 tree maintmpl = CLASSTYPE_TI_TEMPLATE (type);
4282 tree specargs = CLASSTYPE_TI_ARGS (type);
4283 tree inner_args = INNERMOST_TEMPLATE_ARGS (specargs);
4284 tree main_inner_parms = DECL_INNERMOST_TEMPLATE_PARMS (maintmpl);
4287 int nargs = TREE_VEC_LENGTH (inner_args);
4290 bool did_error_intro = false;
4291 struct template_parm_data tpd;
4292 struct template_parm_data tpd2;
4294 gcc_assert (current_template_parms);
4296 inner_parms = INNERMOST_TEMPLATE_PARMS (current_template_parms);
4297 ntparms = TREE_VEC_LENGTH (inner_parms);
4299 /* We check that each of the template parameters given in the
4300 partial specialization is used in the argument list to the
4301 specialization. For example:
4303 template <class T> struct S;
4304 template <class T> struct S<T*>;
4306 The second declaration is OK because `T*' uses the template
4307 parameter T, whereas
4309 template <class T> struct S<int>;
4311 is no good. Even trickier is:
4322 The S2<T> declaration is actually invalid; it is a
4323 full-specialization. Of course,
4326 struct S2<T (*)(U)>;
4328 or some such would have been OK. */
4329 tpd.level = TMPL_PARMS_DEPTH (current_template_parms);
4330 tpd.parms = XALLOCAVEC (int, ntparms);
4331 memset (tpd.parms, 0, sizeof (int) * ntparms);
4333 tpd.arg_uses_template_parms = XALLOCAVEC (int, nargs);
4334 memset (tpd.arg_uses_template_parms, 0, sizeof (int) * nargs);
4335 for (i = 0; i < nargs; ++i)
4337 tpd.current_arg = i;
4338 for_each_template_parm (TREE_VEC_ELT (inner_args, i),
4339 &mark_template_parm,
4342 /*include_nondeduced_p=*/false);
4344 for (i = 0; i < ntparms; ++i)
4345 if (tpd.parms[i] == 0)
4347 /* One of the template parms was not used in the
4349 if (!did_error_intro)
4351 error ("template parameters not used in partial specialization:");
4352 did_error_intro = true;
4355 error (" %qD", TREE_VALUE (TREE_VEC_ELT (inner_parms, i)));
4358 if (did_error_intro)
4359 return error_mark_node;
4361 /* [temp.class.spec]
4363 The argument list of the specialization shall not be identical to
4364 the implicit argument list of the primary template. */
4365 if (comp_template_args
4367 INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE
4369 error ("partial specialization %qT does not specialize any template arguments", type);
4371 /* [temp.class.spec]
4373 A partially specialized non-type argument expression shall not
4374 involve template parameters of the partial specialization except
4375 when the argument expression is a simple identifier.
4377 The type of a template parameter corresponding to a specialized
4378 non-type argument shall not be dependent on a parameter of the
4381 Also, we verify that pack expansions only occur at the
4382 end of the argument list. */
4383 gcc_assert (nargs == DECL_NTPARMS (maintmpl));
4385 for (i = 0; i < nargs; ++i)
4387 tree parm = TREE_VALUE (TREE_VEC_ELT (main_inner_parms, i));
4388 tree arg = TREE_VEC_ELT (inner_args, i);
4389 tree packed_args = NULL_TREE;
4392 if (ARGUMENT_PACK_P (arg))
4394 /* Extract the arguments from the argument pack. We'll be
4395 iterating over these in the following loop. */
4396 packed_args = ARGUMENT_PACK_ARGS (arg);
4397 len = TREE_VEC_LENGTH (packed_args);
4400 for (j = 0; j < len; j++)
4403 /* Get the Jth argument in the parameter pack. */
4404 arg = TREE_VEC_ELT (packed_args, j);
4406 if (PACK_EXPANSION_P (arg))
4408 /* Pack expansions must come at the end of the
4410 if ((packed_args && j < len - 1)
4411 || (!packed_args && i < nargs - 1))
4413 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
4414 error ("parameter pack argument %qE must be at the "
4415 "end of the template argument list", arg);
4417 error ("parameter pack argument %qT must be at the "
4418 "end of the template argument list", arg);
4422 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
4423 /* We only care about the pattern. */
4424 arg = PACK_EXPANSION_PATTERN (arg);
4426 if (/* These first two lines are the `non-type' bit. */
4428 && TREE_CODE (arg) != TEMPLATE_DECL
4429 /* This next line is the `argument expression is not just a
4430 simple identifier' condition and also the `specialized
4431 non-type argument' bit. */
4432 && TREE_CODE (arg) != TEMPLATE_PARM_INDEX)
4434 if ((!packed_args && tpd.arg_uses_template_parms[i])
4435 || (packed_args && uses_template_parms (arg)))
4436 error ("template argument %qE involves template parameter(s)",
4440 /* Look at the corresponding template parameter,
4441 marking which template parameters its type depends
4443 tree type = TREE_TYPE (parm);
4447 /* We haven't yet initialized TPD2. Do so now. */
4448 tpd2.arg_uses_template_parms = XALLOCAVEC (int, nargs);
4449 /* The number of parameters here is the number in the
4450 main template, which, as checked in the assertion
4452 tpd2.parms = XALLOCAVEC (int, nargs);
4454 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (maintmpl));
4457 /* Mark the template parameters. But this time, we're
4458 looking for the template parameters of the main
4459 template, not in the specialization. */
4460 tpd2.current_arg = i;
4461 tpd2.arg_uses_template_parms[i] = 0;
4462 memset (tpd2.parms, 0, sizeof (int) * nargs);
4463 for_each_template_parm (type,
4464 &mark_template_parm,
4467 /*include_nondeduced_p=*/false);
4469 if (tpd2.arg_uses_template_parms [i])
4471 /* The type depended on some template parameters.
4472 If they are fully specialized in the
4473 specialization, that's OK. */
4476 for (j = 0; j < nargs; ++j)
4477 if (tpd2.parms[j] != 0
4478 && tpd.arg_uses_template_parms [j])
4481 error_n (input_location, count,
4482 "type %qT of template argument %qE depends "
4483 "on a template parameter",
4484 "type %qT of template argument %qE depends "
4485 "on template parameters",
4494 /* We should only get here once. */
4495 gcc_assert (!COMPLETE_TYPE_P (type));
4497 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)
4498 = tree_cons (specargs, inner_parms,
4499 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl));
4500 TREE_TYPE (DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)) = type;
4502 for (inst = DECL_TEMPLATE_INSTANTIATIONS (maintmpl); inst;
4503 inst = TREE_CHAIN (inst))
4505 tree inst_type = TREE_VALUE (inst);
4506 if (COMPLETE_TYPE_P (inst_type)
4507 && CLASSTYPE_IMPLICIT_INSTANTIATION (inst_type))
4509 tree spec = most_specialized_class (inst_type, maintmpl, tf_none);
4510 if (spec && TREE_TYPE (spec) == type)
4511 permerror (input_location,
4512 "partial specialization of %qT after instantiation "
4513 "of %qT", type, inst_type);
4520 /* Check that a template declaration's use of default arguments and
4521 parameter packs is not invalid. Here, PARMS are the template
4522 parameters. IS_PRIMARY is nonzero if DECL is the thing declared by
4523 a primary template. IS_PARTIAL is nonzero if DECL is a partial
4527 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4528 declaration (but not a definition); 1 indicates a declaration, 2
4529 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4530 emitted for extraneous default arguments.
4532 Returns TRUE if there were no errors found, FALSE otherwise. */
4535 check_default_tmpl_args (tree decl, tree parms, int is_primary,
4536 int is_partial, int is_friend_decl)
4539 int last_level_to_check;
4541 bool no_errors = true;
4545 A default template-argument shall not be specified in a
4546 function template declaration or a function template definition, nor
4547 in the template-parameter-list of the definition of a member of a
4550 if (TREE_CODE (CP_DECL_CONTEXT (decl)) == FUNCTION_DECL)
4551 /* You can't have a function template declaration in a local
4552 scope, nor you can you define a member of a class template in a
4556 if (current_class_type
4557 && !TYPE_BEING_DEFINED (current_class_type)
4558 && DECL_LANG_SPECIFIC (decl)
4559 && DECL_DECLARES_FUNCTION_P (decl)
4560 /* If this is either a friend defined in the scope of the class
4561 or a member function. */
4562 && (DECL_FUNCTION_MEMBER_P (decl)
4563 ? same_type_p (DECL_CONTEXT (decl), current_class_type)
4564 : DECL_FRIEND_CONTEXT (decl)
4565 ? same_type_p (DECL_FRIEND_CONTEXT (decl), current_class_type)
4567 /* And, if it was a member function, it really was defined in
4568 the scope of the class. */
4569 && (!DECL_FUNCTION_MEMBER_P (decl)
4570 || DECL_INITIALIZED_IN_CLASS_P (decl)))
4571 /* We already checked these parameters when the template was
4572 declared, so there's no need to do it again now. This function
4573 was defined in class scope, but we're processing it's body now
4574 that the class is complete. */
4577 /* Core issue 226 (C++0x only): the following only applies to class
4579 if ((cxx_dialect == cxx98) || TREE_CODE (decl) != FUNCTION_DECL)
4583 If a template-parameter has a default template-argument, all
4584 subsequent template-parameters shall have a default
4585 template-argument supplied. */
4586 for (parm_level = parms; parm_level; parm_level = TREE_CHAIN (parm_level))
4588 tree inner_parms = TREE_VALUE (parm_level);
4589 int ntparms = TREE_VEC_LENGTH (inner_parms);
4590 int seen_def_arg_p = 0;
4593 for (i = 0; i < ntparms; ++i)
4595 tree parm = TREE_VEC_ELT (inner_parms, i);
4597 if (parm == error_mark_node)
4600 if (TREE_PURPOSE (parm))
4602 else if (seen_def_arg_p
4603 && !template_parameter_pack_p (TREE_VALUE (parm)))
4605 error ("no default argument for %qD", TREE_VALUE (parm));
4606 /* For better subsequent error-recovery, we indicate that
4607 there should have been a default argument. */
4608 TREE_PURPOSE (parm) = error_mark_node;
4614 /* Don't complain about an enclosing partial
4616 && parm_level == parms
4617 && TREE_CODE (decl) == TYPE_DECL
4619 && template_parameter_pack_p (TREE_VALUE (parm)))
4621 /* A primary class template can only have one
4622 parameter pack, at the end of the template
4625 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL)
4626 error ("parameter pack %qE must be at the end of the"
4627 " template parameter list", TREE_VALUE (parm));
4629 error ("parameter pack %qT must be at the end of the"
4630 " template parameter list",
4631 TREE_TYPE (TREE_VALUE (parm)));
4633 TREE_VALUE (TREE_VEC_ELT (inner_parms, i))
4641 if (((cxx_dialect == cxx98) && TREE_CODE (decl) != TYPE_DECL)
4645 /* For an ordinary class template, default template arguments are
4646 allowed at the innermost level, e.g.:
4647 template <class T = int>
4649 but, in a partial specialization, they're not allowed even
4650 there, as we have in [temp.class.spec]:
4652 The template parameter list of a specialization shall not
4653 contain default template argument values.
4655 So, for a partial specialization, or for a function template
4656 (in C++98/C++03), we look at all of them. */
4659 /* But, for a primary class template that is not a partial
4660 specialization we look at all template parameters except the
4662 parms = TREE_CHAIN (parms);
4664 /* Figure out what error message to issue. */
4665 if (is_friend_decl == 2)
4666 msg = G_("default template arguments may not be used in function template "
4667 "friend re-declaration");
4668 else if (is_friend_decl)
4669 msg = G_("default template arguments may not be used in function template "
4670 "friend declarations");
4671 else if (TREE_CODE (decl) == FUNCTION_DECL && (cxx_dialect == cxx98))
4672 msg = G_("default template arguments may not be used in function templates "
4673 "without -std=c++11 or -std=gnu++11");
4674 else if (is_partial)
4675 msg = G_("default template arguments may not be used in "
4676 "partial specializations");
4678 msg = G_("default argument for template parameter for class enclosing %qD");
4680 if (current_class_type && TYPE_BEING_DEFINED (current_class_type))
4681 /* If we're inside a class definition, there's no need to
4682 examine the parameters to the class itself. On the one
4683 hand, they will be checked when the class is defined, and,
4684 on the other, default arguments are valid in things like:
4685 template <class T = double>
4686 struct S { template <class U> void f(U); };
4687 Here the default argument for `S' has no bearing on the
4688 declaration of `f'. */
4689 last_level_to_check = template_class_depth (current_class_type) + 1;
4691 /* Check everything. */
4692 last_level_to_check = 0;
4694 for (parm_level = parms;
4695 parm_level && TMPL_PARMS_DEPTH (parm_level) >= last_level_to_check;
4696 parm_level = TREE_CHAIN (parm_level))
4698 tree inner_parms = TREE_VALUE (parm_level);
4702 ntparms = TREE_VEC_LENGTH (inner_parms);
4703 for (i = 0; i < ntparms; ++i)
4705 if (TREE_VEC_ELT (inner_parms, i) == error_mark_node)
4708 if (TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)))
4713 if (is_friend_decl == 2)
4720 /* Clear out the default argument so that we are not
4722 TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)) = NULL_TREE;
4726 /* At this point, if we're still interested in issuing messages,
4727 they must apply to classes surrounding the object declared. */
4729 msg = G_("default argument for template parameter for class "
4736 /* Worker for push_template_decl_real, called via
4737 for_each_template_parm. DATA is really an int, indicating the
4738 level of the parameters we are interested in. If T is a template
4739 parameter of that level, return nonzero. */
4742 template_parm_this_level_p (tree t, void* data)
4744 int this_level = *(int *)data;
4747 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
4748 level = TEMPLATE_PARM_LEVEL (t);
4750 level = TEMPLATE_TYPE_LEVEL (t);
4751 return level == this_level;
4754 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4755 parameters given by current_template_args, or reuses a
4756 previously existing one, if appropriate. Returns the DECL, or an
4757 equivalent one, if it is replaced via a call to duplicate_decls.
4759 If IS_FRIEND is true, DECL is a friend declaration. */
4762 push_template_decl_real (tree decl, bool is_friend)
4770 int new_template_p = 0;
4771 /* True if the template is a member template, in the sense of
4773 bool member_template_p = false;
4775 if (decl == error_mark_node || !current_template_parms)
4776 return error_mark_node;
4778 /* See if this is a partial specialization. */
4779 is_partial = (DECL_IMPLICIT_TYPEDEF_P (decl)
4780 && TREE_CODE (TREE_TYPE (decl)) != ENUMERAL_TYPE
4781 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)));
4783 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_FRIEND_P (decl))
4787 /* For a friend, we want the context of the friend function, not
4788 the type of which it is a friend. */
4789 ctx = CP_DECL_CONTEXT (decl);
4790 else if (CP_DECL_CONTEXT (decl)
4791 && TREE_CODE (CP_DECL_CONTEXT (decl)) != NAMESPACE_DECL)
4792 /* In the case of a virtual function, we want the class in which
4794 ctx = CP_DECL_CONTEXT (decl);
4796 /* Otherwise, if we're currently defining some class, the DECL
4797 is assumed to be a member of the class. */
4798 ctx = current_scope ();
4800 if (ctx && TREE_CODE (ctx) == NAMESPACE_DECL)
4803 if (!DECL_CONTEXT (decl))
4804 DECL_CONTEXT (decl) = FROB_CONTEXT (current_namespace);
4806 /* See if this is a primary template. */
4807 if (is_friend && ctx)
4808 /* A friend template that specifies a class context, i.e.
4809 template <typename T> friend void A<T>::f();
4813 primary = template_parm_scope_p ();
4817 if (DECL_CLASS_SCOPE_P (decl))
4818 member_template_p = true;
4819 if (TREE_CODE (decl) == TYPE_DECL
4820 && ANON_AGGRNAME_P (DECL_NAME (decl)))
4822 error ("template class without a name");
4823 return error_mark_node;
4825 else if (TREE_CODE (decl) == FUNCTION_DECL)
4827 if (DECL_DESTRUCTOR_P (decl))
4831 A destructor shall not be a member template. */
4832 error ("destructor %qD declared as member template", decl);
4833 return error_mark_node;
4835 if (NEW_DELETE_OPNAME_P (DECL_NAME (decl))
4836 && (!prototype_p (TREE_TYPE (decl))
4837 || TYPE_ARG_TYPES (TREE_TYPE (decl)) == void_list_node
4838 || !TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (decl)))
4839 || (TREE_CHAIN (TYPE_ARG_TYPES ((TREE_TYPE (decl))))
4840 == void_list_node)))
4842 /* [basic.stc.dynamic.allocation]
4844 An allocation function can be a function
4845 template. ... Template allocation functions shall
4846 have two or more parameters. */
4847 error ("invalid template declaration of %qD", decl);
4848 return error_mark_node;
4851 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4852 && CLASS_TYPE_P (TREE_TYPE (decl)))
4854 else if (TREE_CODE (decl) == TYPE_DECL
4855 && TYPE_DECL_ALIAS_P (decl))
4856 /* alias-declaration */
4857 gcc_assert (!DECL_ARTIFICIAL (decl));
4860 error ("template declaration of %q#D", decl);
4861 return error_mark_node;
4865 /* Check to see that the rules regarding the use of default
4866 arguments are not being violated. */
4867 check_default_tmpl_args (decl, current_template_parms,
4868 primary, is_partial, /*is_friend_decl=*/0);
4870 /* Ensure that there are no parameter packs in the type of this
4871 declaration that have not been expanded. */
4872 if (TREE_CODE (decl) == FUNCTION_DECL)
4874 /* Check each of the arguments individually to see if there are
4875 any bare parameter packs. */
4876 tree type = TREE_TYPE (decl);
4877 tree arg = DECL_ARGUMENTS (decl);
4878 tree argtype = TYPE_ARG_TYPES (type);
4880 while (arg && argtype)
4882 if (!FUNCTION_PARAMETER_PACK_P (arg)
4883 && check_for_bare_parameter_packs (TREE_TYPE (arg)))
4885 /* This is a PARM_DECL that contains unexpanded parameter
4886 packs. We have already complained about this in the
4887 check_for_bare_parameter_packs call, so just replace
4888 these types with ERROR_MARK_NODE. */
4889 TREE_TYPE (arg) = error_mark_node;
4890 TREE_VALUE (argtype) = error_mark_node;
4893 arg = DECL_CHAIN (arg);
4894 argtype = TREE_CHAIN (argtype);
4897 /* Check for bare parameter packs in the return type and the
4898 exception specifiers. */
4899 if (check_for_bare_parameter_packs (TREE_TYPE (type)))
4900 /* Errors were already issued, set return type to int
4901 as the frontend doesn't expect error_mark_node as
4903 TREE_TYPE (type) = integer_type_node;
4904 if (check_for_bare_parameter_packs (TYPE_RAISES_EXCEPTIONS (type)))
4905 TYPE_RAISES_EXCEPTIONS (type) = NULL_TREE;
4907 else if (check_for_bare_parameter_packs (TREE_TYPE (decl)))
4909 TREE_TYPE (decl) = error_mark_node;
4910 return error_mark_node;
4914 return process_partial_specialization (decl);
4916 args = current_template_args ();
4919 || TREE_CODE (ctx) == FUNCTION_DECL
4920 || (CLASS_TYPE_P (ctx) && TYPE_BEING_DEFINED (ctx))
4921 || (is_friend && !DECL_TEMPLATE_INFO (decl)))
4923 if (DECL_LANG_SPECIFIC (decl)
4924 && DECL_TEMPLATE_INFO (decl)
4925 && DECL_TI_TEMPLATE (decl))
4926 tmpl = DECL_TI_TEMPLATE (decl);
4927 /* If DECL is a TYPE_DECL for a class-template, then there won't
4928 be DECL_LANG_SPECIFIC. The information equivalent to
4929 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4930 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4931 && TYPE_TEMPLATE_INFO (TREE_TYPE (decl))
4932 && TYPE_TI_TEMPLATE (TREE_TYPE (decl)))
4934 /* Since a template declaration already existed for this
4935 class-type, we must be redeclaring it here. Make sure
4936 that the redeclaration is valid. */
4937 redeclare_class_template (TREE_TYPE (decl),
4938 current_template_parms);
4939 /* We don't need to create a new TEMPLATE_DECL; just use the
4940 one we already had. */
4941 tmpl = TYPE_TI_TEMPLATE (TREE_TYPE (decl));
4945 tmpl = build_template_decl (decl, current_template_parms,
4949 if (DECL_LANG_SPECIFIC (decl)
4950 && DECL_TEMPLATE_SPECIALIZATION (decl))
4952 /* A specialization of a member template of a template
4954 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
4955 DECL_TEMPLATE_INFO (tmpl) = DECL_TEMPLATE_INFO (decl);
4956 DECL_TEMPLATE_INFO (decl) = NULL_TREE;
4962 tree a, t, current, parms;
4964 tree tinfo = get_template_info (decl);
4968 error ("template definition of non-template %q#D", decl);
4969 return error_mark_node;
4972 tmpl = TI_TEMPLATE (tinfo);
4974 if (DECL_FUNCTION_TEMPLATE_P (tmpl)
4975 && DECL_TEMPLATE_INFO (decl) && DECL_TI_ARGS (decl)
4976 && DECL_TEMPLATE_SPECIALIZATION (decl)
4977 && DECL_MEMBER_TEMPLATE_P (tmpl))
4981 /* The declaration is a specialization of a member
4982 template, declared outside the class. Therefore, the
4983 innermost template arguments will be NULL, so we
4984 replace them with the arguments determined by the
4985 earlier call to check_explicit_specialization. */
4986 args = DECL_TI_ARGS (decl);
4989 = build_template_decl (decl, current_template_parms,
4991 DECL_TEMPLATE_RESULT (new_tmpl) = decl;
4992 TREE_TYPE (new_tmpl) = TREE_TYPE (decl);
4993 DECL_TI_TEMPLATE (decl) = new_tmpl;
4994 SET_DECL_TEMPLATE_SPECIALIZATION (new_tmpl);
4995 DECL_TEMPLATE_INFO (new_tmpl)
4996 = build_template_info (tmpl, args);
4998 register_specialization (new_tmpl,
4999 most_general_template (tmpl),
5005 /* Make sure the template headers we got make sense. */
5007 parms = DECL_TEMPLATE_PARMS (tmpl);
5008 i = TMPL_PARMS_DEPTH (parms);
5009 if (TMPL_ARGS_DEPTH (args) != i)
5011 error ("expected %d levels of template parms for %q#D, got %d",
5012 i, decl, TMPL_ARGS_DEPTH (args));
5015 for (current = decl; i > 0; --i, parms = TREE_CHAIN (parms))
5017 a = TMPL_ARGS_LEVEL (args, i);
5018 t = INNERMOST_TEMPLATE_PARMS (parms);
5020 if (TREE_VEC_LENGTH (t) != TREE_VEC_LENGTH (a))
5022 if (current == decl)
5023 error ("got %d template parameters for %q#D",
5024 TREE_VEC_LENGTH (a), decl);
5026 error ("got %d template parameters for %q#T",
5027 TREE_VEC_LENGTH (a), current);
5028 error (" but %d required", TREE_VEC_LENGTH (t));
5029 return error_mark_node;
5032 if (current == decl)
5034 else if (current == NULL_TREE)
5035 /* Can happen in erroneous input. */
5038 current = (TYPE_P (current)
5039 ? TYPE_CONTEXT (current)
5040 : DECL_CONTEXT (current));
5043 /* Check that the parms are used in the appropriate qualifying scopes
5044 in the declarator. */
5045 if (!comp_template_args
5047 TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (tmpl)))))
5050 template arguments to %qD do not match original template %qD",
5051 decl, DECL_TEMPLATE_RESULT (tmpl));
5052 if (!uses_template_parms (TI_ARGS (tinfo)))
5053 inform (input_location, "use template<> for an explicit specialization");
5054 /* Avoid crash in import_export_decl. */
5055 DECL_INTERFACE_KNOWN (decl) = 1;
5056 return error_mark_node;
5060 DECL_TEMPLATE_RESULT (tmpl) = decl;
5061 TREE_TYPE (tmpl) = TREE_TYPE (decl);
5063 /* Push template declarations for global functions and types. Note
5064 that we do not try to push a global template friend declared in a
5065 template class; such a thing may well depend on the template
5066 parameters of the class. */
5067 if (new_template_p && !ctx
5068 && !(is_friend && template_class_depth (current_class_type) > 0))
5070 tmpl = pushdecl_namespace_level (tmpl, is_friend);
5071 if (tmpl == error_mark_node)
5072 return error_mark_node;
5074 /* Hide template friend classes that haven't been declared yet. */
5075 if (is_friend && TREE_CODE (decl) == TYPE_DECL)
5077 DECL_ANTICIPATED (tmpl) = 1;
5078 DECL_FRIEND_P (tmpl) = 1;
5084 tree parms = DECL_TEMPLATE_PARMS (tmpl);
5087 DECL_PRIMARY_TEMPLATE (tmpl) = tmpl;
5088 if (DECL_CONV_FN_P (tmpl))
5090 int depth = TMPL_PARMS_DEPTH (parms);
5092 /* It is a conversion operator. See if the type converted to
5093 depends on innermost template operands. */
5095 if (uses_template_parms_level (TREE_TYPE (TREE_TYPE (tmpl)),
5097 DECL_TEMPLATE_CONV_FN_P (tmpl) = 1;
5100 /* Give template template parms a DECL_CONTEXT of the template
5101 for which they are a parameter. */
5102 parms = INNERMOST_TEMPLATE_PARMS (parms);
5103 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
5105 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
5106 if (TREE_CODE (parm) == TEMPLATE_DECL)
5107 DECL_CONTEXT (parm) = tmpl;
5111 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5112 back to its most general template. If TMPL is a specialization,
5113 ARGS may only have the innermost set of arguments. Add the missing
5114 argument levels if necessary. */
5115 if (DECL_TEMPLATE_INFO (tmpl))
5116 args = add_outermost_template_args (DECL_TI_ARGS (tmpl), args);
5118 info = build_template_info (tmpl, args);
5120 if (DECL_IMPLICIT_TYPEDEF_P (decl))
5121 SET_TYPE_TEMPLATE_INFO (TREE_TYPE (tmpl), info);
5124 if (primary && !DECL_LANG_SPECIFIC (decl))
5125 retrofit_lang_decl (decl);
5126 if (DECL_LANG_SPECIFIC (decl))
5127 DECL_TEMPLATE_INFO (decl) = info;
5130 return DECL_TEMPLATE_RESULT (tmpl);
5134 push_template_decl (tree decl)
5136 return push_template_decl_real (decl, false);
5139 /* Called when a class template TYPE is redeclared with the indicated
5140 template PARMS, e.g.:
5142 template <class T> struct S;
5143 template <class T> struct S {}; */
5146 redeclare_class_template (tree type, tree parms)
5152 if (!TYPE_TEMPLATE_INFO (type))
5154 error ("%qT is not a template type", type);
5158 tmpl = TYPE_TI_TEMPLATE (type);
5159 if (!PRIMARY_TEMPLATE_P (tmpl))
5160 /* The type is nested in some template class. Nothing to worry
5161 about here; there are no new template parameters for the nested
5167 error ("template specifiers not specified in declaration of %qD",
5172 parms = INNERMOST_TEMPLATE_PARMS (parms);
5173 tmpl_parms = DECL_INNERMOST_TEMPLATE_PARMS (tmpl);
5175 if (TREE_VEC_LENGTH (parms) != TREE_VEC_LENGTH (tmpl_parms))
5177 error_n (input_location, TREE_VEC_LENGTH (parms),
5178 "redeclared with %d template parameter",
5179 "redeclared with %d template parameters",
5180 TREE_VEC_LENGTH (parms));
5181 inform_n (input_location, TREE_VEC_LENGTH (tmpl_parms),
5182 "previous declaration %q+D used %d template parameter",
5183 "previous declaration %q+D used %d template parameters",
5184 tmpl, TREE_VEC_LENGTH (tmpl_parms));
5188 for (i = 0; i < TREE_VEC_LENGTH (tmpl_parms); ++i)
5195 if (TREE_VEC_ELT (tmpl_parms, i) == error_mark_node
5196 || TREE_VEC_ELT (parms, i) == error_mark_node)
5199 tmpl_parm = TREE_VALUE (TREE_VEC_ELT (tmpl_parms, i));
5200 if (tmpl_parm == error_mark_node)
5203 parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
5204 tmpl_default = TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i));
5205 parm_default = TREE_PURPOSE (TREE_VEC_ELT (parms, i));
5207 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5209 if (TREE_CODE (tmpl_parm) != TREE_CODE (parm)
5210 || (TREE_CODE (tmpl_parm) != TYPE_DECL
5211 && !same_type_p (TREE_TYPE (tmpl_parm), TREE_TYPE (parm)))
5212 || (TREE_CODE (tmpl_parm) != PARM_DECL
5213 && (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (tmpl_parm))
5214 != TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm))))
5215 || (TREE_CODE (tmpl_parm) == PARM_DECL
5216 && (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (tmpl_parm))
5217 != TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))))
5219 error ("template parameter %q+#D", tmpl_parm);
5220 error ("redeclared here as %q#D", parm);
5224 if (tmpl_default != NULL_TREE && parm_default != NULL_TREE)
5226 /* We have in [temp.param]:
5228 A template-parameter may not be given default arguments
5229 by two different declarations in the same scope. */
5230 error_at (input_location, "redefinition of default argument for %q#D", parm);
5231 inform (DECL_SOURCE_LOCATION (tmpl_parm),
5232 "original definition appeared here");
5236 if (parm_default != NULL_TREE)
5237 /* Update the previous template parameters (which are the ones
5238 that will really count) with the new default value. */
5239 TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i)) = parm_default;
5240 else if (tmpl_default != NULL_TREE)
5241 /* Update the new parameters, too; they'll be used as the
5242 parameters for any members. */
5243 TREE_PURPOSE (TREE_VEC_ELT (parms, i)) = tmpl_default;
5249 /* Simplify EXPR if it is a non-dependent expression. Returns the
5250 (possibly simplified) expression. */
5253 fold_non_dependent_expr_sfinae (tree expr, tsubst_flags_t complain)
5255 if (expr == NULL_TREE)
5258 /* If we're in a template, but EXPR isn't value dependent, simplify
5259 it. We're supposed to treat:
5261 template <typename T> void f(T[1 + 1]);
5262 template <typename T> void f(T[2]);
5264 as two declarations of the same function, for example. */
5265 if (processing_template_decl
5266 && !type_dependent_expression_p (expr)
5267 && potential_constant_expression (expr)
5268 && !value_dependent_expression_p (expr))
5270 HOST_WIDE_INT saved_processing_template_decl;
5272 saved_processing_template_decl = processing_template_decl;
5273 processing_template_decl = 0;
5274 expr = tsubst_copy_and_build (expr,
5277 /*in_decl=*/NULL_TREE,
5278 /*function_p=*/false,
5279 /*integral_constant_expression_p=*/true);
5280 processing_template_decl = saved_processing_template_decl;
5286 fold_non_dependent_expr (tree expr)
5288 return fold_non_dependent_expr_sfinae (expr, tf_error);
5291 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5292 template declaration, or a TYPE_DECL for an alias declaration. */
5295 alias_type_or_template_p (tree t)
5299 return ((TREE_CODE (t) == TYPE_DECL && TYPE_DECL_ALIAS_P (t))
5302 && TYPE_DECL_ALIAS_P (TYPE_NAME (t)))
5303 || DECL_ALIAS_TEMPLATE_P (t));
5306 /* Return TRUE iff is a specialization of an alias template. */
5309 alias_template_specialization_p (tree t)
5313 return (primary_template_instantiation_p (t)
5314 && DECL_ALIAS_TEMPLATE_P (TYPE_TI_TEMPLATE (t)));
5317 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5318 must be a function or a pointer-to-function type, as specified
5319 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5320 and check that the resulting function has external linkage. */
5323 convert_nontype_argument_function (tree type, tree expr)
5328 fn = instantiate_type (type, fns, tf_none);
5329 if (fn == error_mark_node)
5330 return error_mark_node;
5333 if (TREE_CODE (fn_no_ptr) == ADDR_EXPR)
5334 fn_no_ptr = TREE_OPERAND (fn_no_ptr, 0);
5335 if (BASELINK_P (fn_no_ptr))
5336 fn_no_ptr = BASELINK_FUNCTIONS (fn_no_ptr);
5338 /* [temp.arg.nontype]/1
5340 A template-argument for a non-type, non-template template-parameter
5343 -- the address of an object or function with external linkage. */
5344 if (!DECL_EXTERNAL_LINKAGE_P (fn_no_ptr))
5346 error ("%qE is not a valid template argument for type %qT "
5347 "because function %qD has not external linkage",
5348 expr, type, fn_no_ptr);
5355 /* Subroutine of convert_nontype_argument.
5356 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5357 Emit an error otherwise. */
5360 check_valid_ptrmem_cst_expr (tree type, tree expr,
5361 tsubst_flags_t complain)
5364 if (expr && (null_ptr_cst_p (expr) || TREE_CODE (expr) == PTRMEM_CST))
5366 if (cxx_dialect >= cxx0x && null_member_pointer_value_p (expr))
5368 if (complain & tf_error)
5370 error ("%qE is not a valid template argument for type %qT",
5372 error ("it must be a pointer-to-member of the form %<&X::Y%>");
5377 /* Returns TRUE iff the address of OP is value-dependent.
5379 14.6.2.4 [temp.dep.temp]:
5380 A non-integral non-type template-argument is dependent if its type is
5381 dependent or it has either of the following forms
5384 and contains a nested-name-specifier which specifies a class-name that
5385 names a dependent type.
5387 We generalize this to just say that the address of a member of a
5388 dependent class is value-dependent; the above doesn't cover the
5389 address of a static data member named with an unqualified-id. */
5392 has_value_dependent_address (tree op)
5394 /* We could use get_inner_reference here, but there's no need;
5395 this is only relevant for template non-type arguments, which
5396 can only be expressed as &id-expression. */
5399 tree ctx = CP_DECL_CONTEXT (op);
5400 if (TYPE_P (ctx) && dependent_type_p (ctx))
5407 /* The next set of functions are used for providing helpful explanatory
5408 diagnostics for failed overload resolution. Their messages should be
5409 indented by two spaces for consistency with the messages in
5413 unify_success (bool explain_p ATTRIBUTE_UNUSED)
5419 unify_parameter_deduction_failure (bool explain_p, tree parm)
5422 inform (input_location,
5423 " couldn't deduce template parameter %qD", parm);
5428 unify_invalid (bool explain_p ATTRIBUTE_UNUSED)
5434 unify_cv_qual_mismatch (bool explain_p, tree parm, tree arg)
5437 inform (input_location,
5438 " types %qT and %qT have incompatible cv-qualifiers",
5444 unify_type_mismatch (bool explain_p, tree parm, tree arg)
5447 inform (input_location, " mismatched types %qT and %qT", parm, arg);
5452 unify_parameter_pack_mismatch (bool explain_p, tree parm, tree arg)
5455 inform (input_location,
5456 " template parameter %qD is not a parameter pack, but "
5463 unify_ptrmem_cst_mismatch (bool explain_p, tree parm, tree arg)
5466 inform (input_location,
5467 " template argument %qE does not match "
5468 "pointer-to-member constant %qE",
5474 unify_expression_unequal (bool explain_p, tree parm, tree arg)
5477 inform (input_location, " %qE is not equivalent to %qE", parm, arg);
5482 unify_parameter_pack_inconsistent (bool explain_p, tree old_arg, tree new_arg)
5485 inform (input_location,
5486 " inconsistent parameter pack deduction with %qT and %qT",
5492 unify_inconsistency (bool explain_p, tree parm, tree first, tree second)
5495 inform (input_location,
5496 " deduced conflicting types for parameter %qT (%qT and %qT)",
5497 parm, first, second);
5502 unify_vla_arg (bool explain_p, tree arg)
5505 inform (input_location,
5506 " variable-sized array type %qT is not "
5507 "a valid template argument",
5513 unify_method_type_error (bool explain_p, tree arg)
5516 inform (input_location,
5517 " member function type %qT is not a valid template argument",
5523 unify_arity (bool explain_p, int have, int wanted)
5526 inform_n (input_location, wanted,
5527 " candidate expects %d argument, %d provided",
5528 " candidate expects %d arguments, %d provided",
5534 unify_too_many_arguments (bool explain_p, int have, int wanted)
5536 return unify_arity (explain_p, have, wanted);
5540 unify_too_few_arguments (bool explain_p, int have, int wanted)
5542 return unify_arity (explain_p, have, wanted);
5546 unify_arg_conversion (bool explain_p, tree to_type,
5547 tree from_type, tree arg)
5550 inform (input_location, " cannot convert %qE (type %qT) to type %qT",
5551 arg, from_type, to_type);
5556 unify_no_common_base (bool explain_p, enum template_base_result r,
5557 tree parm, tree arg)
5562 case tbr_ambiguous_baseclass:
5563 inform (input_location, " %qT is an ambiguous base class of %qT",
5567 inform (input_location, " %qT is not derived from %qT", arg, parm);
5574 unify_inconsistent_template_template_parameters (bool explain_p)
5577 inform (input_location,
5578 " template parameters of a template template argument are "
5579 "inconsistent with other deduced template arguments");
5584 unify_template_deduction_failure (bool explain_p, tree parm, tree arg)
5587 inform (input_location,
5588 " can't deduce a template for %qT from non-template type %qT",
5594 unify_template_argument_mismatch (bool explain_p, tree parm, tree arg)
5597 inform (input_location,
5598 " template argument %qE does not match %qD", arg, parm);
5603 unify_overload_resolution_failure (bool explain_p, tree arg)
5606 inform (input_location,
5607 " could not resolve address from overloaded function %qE",
5612 /* Attempt to convert the non-type template parameter EXPR to the
5613 indicated TYPE. If the conversion is successful, return the
5614 converted value. If the conversion is unsuccessful, return
5615 NULL_TREE if we issued an error message, or error_mark_node if we
5616 did not. We issue error messages for out-and-out bad template
5617 parameters, but not simply because the conversion failed, since we
5618 might be just trying to do argument deduction. Both TYPE and EXPR
5619 must be non-dependent.
5621 The conversion follows the special rules described in
5622 [temp.arg.nontype], and it is much more strict than an implicit
5625 This function is called twice for each template argument (see
5626 lookup_template_class for a more accurate description of this
5627 problem). This means that we need to handle expressions which
5628 are not valid in a C++ source, but can be created from the
5629 first call (for instance, casts to perform conversions). These
5630 hacks can go away after we fix the double coercion problem. */
5633 convert_nontype_argument (tree type, tree expr, tsubst_flags_t complain)
5637 /* Detect immediately string literals as invalid non-type argument.
5638 This special-case is not needed for correctness (we would easily
5639 catch this later), but only to provide better diagnostic for this
5640 common user mistake. As suggested by DR 100, we do not mention
5641 linkage issues in the diagnostic as this is not the point. */
5642 /* FIXME we're making this OK. */
5643 if (TREE_CODE (expr) == STRING_CST)
5645 if (complain & tf_error)
5646 error ("%qE is not a valid template argument for type %qT "
5647 "because string literals can never be used in this context",
5652 /* Add the ADDR_EXPR now for the benefit of
5653 value_dependent_expression_p. */
5654 if (TYPE_PTROBV_P (type)
5655 && TREE_CODE (TREE_TYPE (expr)) == ARRAY_TYPE)
5656 expr = decay_conversion (expr);
5658 /* If we are in a template, EXPR may be non-dependent, but still
5659 have a syntactic, rather than semantic, form. For example, EXPR
5660 might be a SCOPE_REF, rather than the VAR_DECL to which the
5661 SCOPE_REF refers. Preserving the qualifying scope is necessary
5662 so that access checking can be performed when the template is
5663 instantiated -- but here we need the resolved form so that we can
5664 convert the argument. */
5665 if (TYPE_REF_OBJ_P (type)
5666 && has_value_dependent_address (expr))
5667 /* If we want the address and it's value-dependent, don't fold. */;
5668 else if (!type_unknown_p (expr))
5669 expr = fold_non_dependent_expr_sfinae (expr, complain);
5670 if (error_operand_p (expr))
5671 return error_mark_node;
5672 expr_type = TREE_TYPE (expr);
5673 if (TREE_CODE (type) == REFERENCE_TYPE)
5674 expr = mark_lvalue_use (expr);
5676 expr = mark_rvalue_use (expr);
5678 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
5679 to a non-type argument of "nullptr". */
5680 if (expr == nullptr_node
5681 && (TYPE_PTR_P (type) || TYPE_PTR_TO_MEMBER_P (type)))
5682 expr = convert (type, expr);
5684 /* In C++11, non-type template arguments can be arbitrary constant
5685 expressions. But don't fold a PTRMEM_CST to a CONSTRUCTOR yet. */
5686 if (cxx_dialect >= cxx0x && TREE_CODE (expr) != PTRMEM_CST)
5687 expr = maybe_constant_value (expr);
5689 /* HACK: Due to double coercion, we can get a
5690 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5691 which is the tree that we built on the first call (see
5692 below when coercing to reference to object or to reference to
5693 function). We just strip everything and get to the arg.
5694 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5696 if (TYPE_REF_OBJ_P (type) || TYPE_REFFN_P (type))
5698 tree probe_type, probe = expr;
5699 if (REFERENCE_REF_P (probe))
5700 probe = TREE_OPERAND (probe, 0);
5701 probe_type = TREE_TYPE (probe);
5702 if (TREE_CODE (probe) == NOP_EXPR)
5704 /* ??? Maybe we could use convert_from_reference here, but we
5705 would need to relax its constraints because the NOP_EXPR
5706 could actually change the type to something more cv-qualified,
5707 and this is not folded by convert_from_reference. */
5708 tree addr = TREE_OPERAND (probe, 0);
5709 gcc_assert (TREE_CODE (probe_type) == REFERENCE_TYPE);
5710 gcc_assert (TREE_CODE (addr) == ADDR_EXPR);
5711 gcc_assert (TREE_CODE (TREE_TYPE (addr)) == POINTER_TYPE);
5712 gcc_assert (same_type_ignoring_top_level_qualifiers_p
5713 (TREE_TYPE (probe_type),
5714 TREE_TYPE (TREE_TYPE (addr))));
5716 expr = TREE_OPERAND (addr, 0);
5717 expr_type = TREE_TYPE (expr);
5721 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5722 parameter is a pointer to object, through decay and
5723 qualification conversion. Let's strip everything. */
5724 else if (TREE_CODE (expr) == NOP_EXPR && TYPE_PTROBV_P (type))
5727 gcc_assert (TREE_CODE (expr) == ADDR_EXPR);
5728 gcc_assert (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE);
5729 /* Skip the ADDR_EXPR only if it is part of the decay for
5730 an array. Otherwise, it is part of the original argument
5731 in the source code. */
5732 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == ARRAY_TYPE)
5733 expr = TREE_OPERAND (expr, 0);
5734 expr_type = TREE_TYPE (expr);
5737 /* [temp.arg.nontype]/5, bullet 1
5739 For a non-type template-parameter of integral or enumeration type,
5740 integral promotions (_conv.prom_) and integral conversions
5741 (_conv.integral_) are applied. */
5742 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
5744 tree t = build_integral_nontype_arg_conv (type, expr, complain);
5745 t = maybe_constant_value (t);
5746 if (t != error_mark_node)
5749 if (!same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (expr)))
5750 return error_mark_node;
5752 /* Notice that there are constant expressions like '4 % 0' which
5753 do not fold into integer constants. */
5754 if (TREE_CODE (expr) != INTEGER_CST)
5756 if (complain & tf_error)
5758 int errs = errorcount, warns = warningcount;
5759 expr = cxx_constant_value (expr);
5760 if (errorcount > errs || warningcount > warns)
5761 inform (EXPR_LOC_OR_HERE (expr),
5762 "in template argument for type %qT ", type);
5763 if (expr == error_mark_node)
5765 /* else cxx_constant_value complained but gave us
5766 a real constant, so go ahead. */
5767 gcc_assert (TREE_CODE (expr) == INTEGER_CST);
5773 /* [temp.arg.nontype]/5, bullet 2
5775 For a non-type template-parameter of type pointer to object,
5776 qualification conversions (_conv.qual_) and the array-to-pointer
5777 conversion (_conv.array_) are applied. */
5778 else if (TYPE_PTROBV_P (type))
5780 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5782 A template-argument for a non-type, non-template template-parameter
5783 shall be one of: [...]
5785 -- the name of a non-type template-parameter;
5786 -- the address of an object or function with external linkage, [...]
5787 expressed as "& id-expression" where the & is optional if the name
5788 refers to a function or array, or if the corresponding
5789 template-parameter is a reference.
5791 Here, we do not care about functions, as they are invalid anyway
5792 for a parameter of type pointer-to-object. */
5794 if (DECL_P (expr) && DECL_TEMPLATE_PARM_P (expr))
5795 /* Non-type template parameters are OK. */
5797 else if (cxx_dialect >= cxx0x && integer_zerop (expr))
5798 /* Null pointer values are OK in C++11. */;
5799 else if (TREE_CODE (expr) != ADDR_EXPR
5800 && TREE_CODE (expr_type) != ARRAY_TYPE)
5802 if (TREE_CODE (expr) == VAR_DECL)
5804 error ("%qD is not a valid template argument "
5805 "because %qD is a variable, not the address of "
5810 /* Other values, like integer constants, might be valid
5811 non-type arguments of some other type. */
5812 return error_mark_node;
5818 decl = ((TREE_CODE (expr) == ADDR_EXPR)
5819 ? TREE_OPERAND (expr, 0) : expr);
5820 if (TREE_CODE (decl) != VAR_DECL)
5822 error ("%qE is not a valid template argument of type %qT "
5823 "because %qE is not a variable",
5827 else if (!DECL_EXTERNAL_LINKAGE_P (decl))
5829 error ("%qE is not a valid template argument of type %qT "
5830 "because %qD does not have external linkage",
5836 expr = decay_conversion (expr);
5837 if (expr == error_mark_node)
5838 return error_mark_node;
5840 expr = perform_qualification_conversions (type, expr);
5841 if (expr == error_mark_node)
5842 return error_mark_node;
5844 /* [temp.arg.nontype]/5, bullet 3
5846 For a non-type template-parameter of type reference to object, no
5847 conversions apply. The type referred to by the reference may be more
5848 cv-qualified than the (otherwise identical) type of the
5849 template-argument. The template-parameter is bound directly to the
5850 template-argument, which must be an lvalue. */
5851 else if (TYPE_REF_OBJ_P (type))
5853 if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type),
5855 return error_mark_node;
5857 if (!at_least_as_qualified_p (TREE_TYPE (type), expr_type))
5859 error ("%qE is not a valid template argument for type %qT "
5860 "because of conflicts in cv-qualification", expr, type);
5864 if (!real_lvalue_p (expr))
5866 error ("%qE is not a valid template argument for type %qT "
5867 "because it is not an lvalue", expr, type);
5871 /* [temp.arg.nontype]/1
5873 A template-argument for a non-type, non-template template-parameter
5874 shall be one of: [...]
5876 -- the address of an object or function with external linkage. */
5877 if (TREE_CODE (expr) == INDIRECT_REF
5878 && TYPE_REF_OBJ_P (TREE_TYPE (TREE_OPERAND (expr, 0))))
5880 expr = TREE_OPERAND (expr, 0);
5883 error ("%q#D is not a valid template argument for type %qT "
5884 "because a reference variable does not have a constant "
5885 "address", expr, type);
5892 error ("%qE is not a valid template argument for type %qT "
5893 "because it is not an object with external linkage",
5898 if (!DECL_EXTERNAL_LINKAGE_P (expr))
5900 error ("%qE is not a valid template argument for type %qT "
5901 "because object %qD has not external linkage",
5906 expr = build_nop (type, build_address (expr));
5908 /* [temp.arg.nontype]/5, bullet 4
5910 For a non-type template-parameter of type pointer to function, only
5911 the function-to-pointer conversion (_conv.func_) is applied. If the
5912 template-argument represents a set of overloaded functions (or a
5913 pointer to such), the matching function is selected from the set
5915 else if (TYPE_PTRFN_P (type))
5917 /* If the argument is a template-id, we might not have enough
5918 context information to decay the pointer. */
5919 if (!type_unknown_p (expr_type))
5921 expr = decay_conversion (expr);
5922 if (expr == error_mark_node)
5923 return error_mark_node;
5926 if (cxx_dialect >= cxx0x && integer_zerop (expr))
5927 /* Null pointer values are OK in C++11. */
5928 return perform_qualification_conversions (type, expr);
5930 expr = convert_nontype_argument_function (type, expr);
5931 if (!expr || expr == error_mark_node)
5934 if (TREE_CODE (expr) != ADDR_EXPR)
5936 error ("%qE is not a valid template argument for type %qT", expr, type);
5937 error ("it must be the address of a function with external linkage");
5941 /* [temp.arg.nontype]/5, bullet 5
5943 For a non-type template-parameter of type reference to function, no
5944 conversions apply. If the template-argument represents a set of
5945 overloaded functions, the matching function is selected from the set
5947 else if (TYPE_REFFN_P (type))
5949 if (TREE_CODE (expr) == ADDR_EXPR)
5951 error ("%qE is not a valid template argument for type %qT "
5952 "because it is a pointer", expr, type);
5953 inform (input_location, "try using %qE instead", TREE_OPERAND (expr, 0));
5957 expr = convert_nontype_argument_function (TREE_TYPE (type), expr);
5958 if (!expr || expr == error_mark_node)
5961 expr = build_nop (type, build_address (expr));
5963 /* [temp.arg.nontype]/5, bullet 6
5965 For a non-type template-parameter of type pointer to member function,
5966 no conversions apply. If the template-argument represents a set of
5967 overloaded member functions, the matching member function is selected
5968 from the set (_over.over_). */
5969 else if (TYPE_PTRMEMFUNC_P (type))
5971 expr = instantiate_type (type, expr, tf_none);
5972 if (expr == error_mark_node)
5973 return error_mark_node;
5975 /* [temp.arg.nontype] bullet 1 says the pointer to member
5976 expression must be a pointer-to-member constant. */
5977 if (!check_valid_ptrmem_cst_expr (type, expr, complain))
5978 return error_mark_node;
5980 /* There is no way to disable standard conversions in
5981 resolve_address_of_overloaded_function (called by
5982 instantiate_type). It is possible that the call succeeded by
5983 converting &B::I to &D::I (where B is a base of D), so we need
5984 to reject this conversion here.
5986 Actually, even if there was a way to disable standard conversions,
5987 it would still be better to reject them here so that we can
5988 provide a superior diagnostic. */
5989 if (!same_type_p (TREE_TYPE (expr), type))
5991 error ("%qE is not a valid template argument for type %qT "
5992 "because it is of type %qT", expr, type,
5994 /* If we are just one standard conversion off, explain. */
5995 if (can_convert (type, TREE_TYPE (expr)))
5996 inform (input_location,
5997 "standard conversions are not allowed in this context");
6001 /* [temp.arg.nontype]/5, bullet 7
6003 For a non-type template-parameter of type pointer to data member,
6004 qualification conversions (_conv.qual_) are applied. */
6005 else if (TYPE_PTRMEM_P (type))
6007 /* [temp.arg.nontype] bullet 1 says the pointer to member
6008 expression must be a pointer-to-member constant. */
6009 if (!check_valid_ptrmem_cst_expr (type, expr, complain))
6010 return error_mark_node;
6012 expr = perform_qualification_conversions (type, expr);
6013 if (expr == error_mark_node)
6016 else if (NULLPTR_TYPE_P (type))
6018 if (expr != nullptr_node)
6020 error ("%qE is not a valid template argument for type %qT "
6021 "because it is of type %qT", expr, type, TREE_TYPE (expr));
6026 /* A template non-type parameter must be one of the above. */
6030 /* Sanity check: did we actually convert the argument to the
6032 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6033 (type, TREE_TYPE (expr)));
6037 /* Subroutine of coerce_template_template_parms, which returns 1 if
6038 PARM_PARM and ARG_PARM match using the rule for the template
6039 parameters of template template parameters. Both PARM and ARG are
6040 template parameters; the rest of the arguments are the same as for
6041 coerce_template_template_parms.
6044 coerce_template_template_parm (tree parm,
6046 tsubst_flags_t complain,
6050 if (arg == NULL_TREE || arg == error_mark_node
6051 || parm == NULL_TREE || parm == error_mark_node)
6054 if (TREE_CODE (arg) != TREE_CODE (parm))
6057 switch (TREE_CODE (parm))
6060 /* We encounter instantiations of templates like
6061 template <template <template <class> class> class TT>
6064 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
6065 tree argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
6067 if (!coerce_template_template_parms
6068 (parmparm, argparm, complain, in_decl, outer_args))
6074 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (arg))
6075 && !TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
6076 /* Argument is a parameter pack but parameter is not. */
6081 /* The tsubst call is used to handle cases such as
6083 template <int> class C {};
6084 template <class T, template <T> class TT> class D {};
6087 i.e. the parameter list of TT depends on earlier parameters. */
6088 if (!uses_template_parms (TREE_TYPE (arg))
6090 (tsubst (TREE_TYPE (parm), outer_args, complain, in_decl),
6094 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (arg))
6095 && !TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
6096 /* Argument is a parameter pack but parameter is not. */
6109 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
6110 template template parameters. Both PARM_PARMS and ARG_PARMS are
6111 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
6114 Consider the example:
6115 template <class T> class A;
6116 template<template <class U> class TT> class B;
6118 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
6119 the parameters to A, and OUTER_ARGS contains A. */
6122 coerce_template_template_parms (tree parm_parms,
6124 tsubst_flags_t complain,
6128 int nparms, nargs, i;
6132 gcc_assert (TREE_CODE (parm_parms) == TREE_VEC);
6133 gcc_assert (TREE_CODE (arg_parms) == TREE_VEC);
6135 nparms = TREE_VEC_LENGTH (parm_parms);
6136 nargs = TREE_VEC_LENGTH (arg_parms);
6138 /* Determine whether we have a parameter pack at the end of the
6139 template template parameter's template parameter list. */
6140 if (TREE_VEC_ELT (parm_parms, nparms - 1) != error_mark_node)
6142 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, nparms - 1));
6144 if (parm == error_mark_node)
6147 switch (TREE_CODE (parm))
6151 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
6156 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
6166 && !(variadic_p && nargs >= nparms - 1))
6169 /* Check all of the template parameters except the parameter pack at
6170 the end (if any). */
6171 for (i = 0; i < nparms - variadic_p; ++i)
6173 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node
6174 || TREE_VEC_ELT (arg_parms, i) == error_mark_node)
6177 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
6178 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
6180 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
6188 /* Check each of the template parameters in the template
6189 argument against the template parameter pack at the end of
6190 the template template parameter. */
6191 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node)
6194 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
6196 for (; i < nargs; ++i)
6198 if (TREE_VEC_ELT (arg_parms, i) == error_mark_node)
6201 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
6203 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
6212 /* Verifies that the deduced template arguments (in TARGS) for the
6213 template template parameters (in TPARMS) represent valid bindings,
6214 by comparing the template parameter list of each template argument
6215 to the template parameter list of its corresponding template
6216 template parameter, in accordance with DR150. This
6217 routine can only be called after all template arguments have been
6218 deduced. It will return TRUE if all of the template template
6219 parameter bindings are okay, FALSE otherwise. */
6221 template_template_parm_bindings_ok_p (tree tparms, tree targs)
6223 int i, ntparms = TREE_VEC_LENGTH (tparms);
6226 /* We're dealing with template parms in this process. */
6227 ++processing_template_decl;
6229 targs = INNERMOST_TEMPLATE_ARGS (targs);
6231 for (i = 0; i < ntparms; ++i)
6233 tree tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
6234 tree targ = TREE_VEC_ELT (targs, i);
6236 if (TREE_CODE (tparm) == TEMPLATE_DECL && targ)
6238 tree packed_args = NULL_TREE;
6241 if (ARGUMENT_PACK_P (targ))
6243 /* Look inside the argument pack. */
6244 packed_args = ARGUMENT_PACK_ARGS (targ);
6245 len = TREE_VEC_LENGTH (packed_args);
6248 for (idx = 0; idx < len; ++idx)
6250 tree targ_parms = NULL_TREE;
6253 /* Extract the next argument from the argument
6255 targ = TREE_VEC_ELT (packed_args, idx);
6257 if (PACK_EXPANSION_P (targ))
6258 /* Look at the pattern of the pack expansion. */
6259 targ = PACK_EXPANSION_PATTERN (targ);
6261 /* Extract the template parameters from the template
6263 if (TREE_CODE (targ) == TEMPLATE_DECL)
6264 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (targ);
6265 else if (TREE_CODE (targ) == TEMPLATE_TEMPLATE_PARM)
6266 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (TYPE_NAME (targ));
6268 /* Verify that we can coerce the template template
6269 parameters from the template argument to the template
6270 parameter. This requires an exact match. */
6272 && !coerce_template_template_parms
6273 (DECL_INNERMOST_TEMPLATE_PARMS (tparm),
6288 --processing_template_decl;
6292 /* Since type attributes aren't mangled, we need to strip them from
6293 template type arguments. */
6296 canonicalize_type_argument (tree arg, tsubst_flags_t complain)
6299 if (!arg || arg == error_mark_node || arg == TYPE_CANONICAL (arg))
6301 mv = TYPE_MAIN_VARIANT (arg);
6302 arg = strip_typedefs (arg);
6303 if (TYPE_ALIGN (arg) != TYPE_ALIGN (mv)
6304 || TYPE_ATTRIBUTES (arg) != TYPE_ATTRIBUTES (mv))
6306 if (complain & tf_warning)
6307 warning (0, "ignoring attributes on template argument %qT", arg);
6308 arg = build_aligned_type (arg, TYPE_ALIGN (mv));
6309 arg = cp_build_type_attribute_variant (arg, TYPE_ATTRIBUTES (mv));
6314 /* Convert the indicated template ARG as necessary to match the
6315 indicated template PARM. Returns the converted ARG, or
6316 error_mark_node if the conversion was unsuccessful. Error and
6317 warning messages are issued under control of COMPLAIN. This
6318 conversion is for the Ith parameter in the parameter list. ARGS is
6319 the full set of template arguments deduced so far. */
6322 convert_template_argument (tree parm,
6325 tsubst_flags_t complain,
6331 int is_type, requires_type, is_tmpl_type, requires_tmpl_type;
6333 if (TREE_CODE (arg) == TREE_LIST
6334 && TREE_CODE (TREE_VALUE (arg)) == OFFSET_REF)
6336 /* The template argument was the name of some
6337 member function. That's usually
6338 invalid, but static members are OK. In any
6339 case, grab the underlying fields/functions
6340 and issue an error later if required. */
6341 orig_arg = TREE_VALUE (arg);
6342 TREE_TYPE (arg) = unknown_type_node;
6347 requires_tmpl_type = TREE_CODE (parm) == TEMPLATE_DECL;
6348 requires_type = (TREE_CODE (parm) == TYPE_DECL
6349 || requires_tmpl_type);
6351 /* When determining whether an argument pack expansion is a template,
6352 look at the pattern. */
6353 if (TREE_CODE (arg) == TYPE_PACK_EXPANSION)
6354 arg = PACK_EXPANSION_PATTERN (arg);
6356 /* Deal with an injected-class-name used as a template template arg. */
6357 if (requires_tmpl_type && CLASS_TYPE_P (arg))
6359 tree t = maybe_get_template_decl_from_type_decl (TYPE_NAME (arg));
6360 if (TREE_CODE (t) == TEMPLATE_DECL)
6362 if (cxx_dialect >= cxx0x)
6363 /* OK under DR 1004. */;
6364 else if (complain & tf_warning_or_error)
6365 pedwarn (input_location, OPT_pedantic, "injected-class-name %qD"
6366 " used as template template argument", TYPE_NAME (arg));
6367 else if (flag_pedantic_errors)
6375 ((TREE_CODE (arg) == TEMPLATE_DECL
6376 && TREE_CODE (DECL_TEMPLATE_RESULT (arg)) == TYPE_DECL)
6377 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
6378 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE);
6381 && (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
6382 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE))
6383 arg = TYPE_STUB_DECL (arg);
6385 is_type = TYPE_P (arg) || is_tmpl_type;
6387 if (requires_type && ! is_type && TREE_CODE (arg) == SCOPE_REF
6388 && TREE_CODE (TREE_OPERAND (arg, 0)) == TEMPLATE_TYPE_PARM)
6390 permerror (input_location, "to refer to a type member of a template parameter, "
6391 "use %<typename %E%>", orig_arg);
6393 orig_arg = make_typename_type (TREE_OPERAND (arg, 0),
6394 TREE_OPERAND (arg, 1),
6396 complain & tf_error);
6400 if (is_type != requires_type)
6404 if (complain & tf_error)
6406 error ("type/value mismatch at argument %d in template "
6407 "parameter list for %qD",
6410 error (" expected a constant of type %qT, got %qT",
6412 (DECL_P (arg) ? DECL_NAME (arg) : orig_arg));
6413 else if (requires_tmpl_type)
6414 error (" expected a class template, got %qE", orig_arg);
6416 error (" expected a type, got %qE", orig_arg);
6419 return error_mark_node;
6421 if (is_tmpl_type ^ requires_tmpl_type)
6423 if (in_decl && (complain & tf_error))
6425 error ("type/value mismatch at argument %d in template "
6426 "parameter list for %qD",
6429 error (" expected a type, got %qT", DECL_NAME (arg));
6431 error (" expected a class template, got %qT", orig_arg);
6433 return error_mark_node;
6438 if (requires_tmpl_type)
6440 if (TREE_CODE (TREE_TYPE (arg)) == UNBOUND_CLASS_TEMPLATE)
6441 /* The number of argument required is not known yet.
6442 Just accept it for now. */
6443 val = TREE_TYPE (arg);
6446 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
6449 argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
6451 if (coerce_template_template_parms (parmparm, argparm,
6457 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6459 if (val != error_mark_node)
6461 if (DECL_TEMPLATE_TEMPLATE_PARM_P (val))
6462 val = TREE_TYPE (val);
6463 if (TREE_CODE (orig_arg) == TYPE_PACK_EXPANSION)
6464 val = make_pack_expansion (val);
6469 if (in_decl && (complain & tf_error))
6471 error ("type/value mismatch at argument %d in "
6472 "template parameter list for %qD",
6474 error (" expected a template of type %qD, got %qT",
6478 val = error_mark_node;
6484 /* We only form one instance of each template specialization.
6485 Therefore, if we use a non-canonical variant (i.e., a
6486 typedef), any future messages referring to the type will use
6487 the typedef, which is confusing if those future uses do not
6488 themselves also use the typedef. */
6490 val = canonicalize_type_argument (val, complain);
6494 tree t = tsubst (TREE_TYPE (parm), args, complain, in_decl);
6496 if (invalid_nontype_parm_type_p (t, complain))
6497 return error_mark_node;
6499 if (template_parameter_pack_p (parm) && ARGUMENT_PACK_P (orig_arg))
6501 if (same_type_p (t, TREE_TYPE (orig_arg)))
6505 /* Not sure if this is reachable, but it doesn't hurt
6507 error ("type mismatch in nontype parameter pack");
6508 val = error_mark_node;
6511 else if (!uses_template_parms (orig_arg) && !uses_template_parms (t))
6512 /* We used to call digest_init here. However, digest_init
6513 will report errors, which we don't want when complain
6514 is zero. More importantly, digest_init will try too
6515 hard to convert things: for example, `0' should not be
6516 converted to pointer type at this point according to
6517 the standard. Accepting this is not merely an
6518 extension, since deciding whether or not these
6519 conversions can occur is part of determining which
6520 function template to call, or whether a given explicit
6521 argument specification is valid. */
6522 val = convert_nontype_argument (t, orig_arg, complain);
6526 if (val == NULL_TREE)
6527 val = error_mark_node;
6528 else if (val == error_mark_node && (complain & tf_error))
6529 error ("could not convert template argument %qE to %qT", orig_arg, t);
6531 if (TREE_CODE (val) == SCOPE_REF)
6533 /* Strip typedefs from the SCOPE_REF. */
6534 tree type = canonicalize_type_argument (TREE_TYPE (val), complain);
6535 tree scope = canonicalize_type_argument (TREE_OPERAND (val, 0),
6537 val = build_qualified_name (type, scope, TREE_OPERAND (val, 1),
6538 QUALIFIED_NAME_IS_TEMPLATE (val));
6545 /* Coerces the remaining template arguments in INNER_ARGS (from
6546 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6547 Returns the coerced argument pack. PARM_IDX is the position of this
6548 parameter in the template parameter list. ARGS is the original
6549 template argument list. */
6551 coerce_template_parameter_pack (tree parms,
6559 tsubst_flags_t complain)
6561 tree parm = TREE_VEC_ELT (parms, parm_idx);
6562 int nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
6565 tree packed_types = NULL_TREE;
6567 if (arg_idx > nargs)
6570 packed_args = make_tree_vec (nargs - arg_idx);
6572 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL
6573 && uses_parameter_packs (TREE_TYPE (TREE_VALUE (parm))))
6575 /* When the template parameter is a non-type template
6576 parameter pack whose type uses parameter packs, we need
6577 to look at each of the template arguments
6578 separately. Build a vector of the types for these
6579 non-type template parameters in PACKED_TYPES. */
6581 = make_pack_expansion (TREE_TYPE (TREE_VALUE (parm)));
6582 packed_types = tsubst_pack_expansion (expansion, args,
6585 if (packed_types == error_mark_node)
6586 return error_mark_node;
6588 /* Check that we have the right number of arguments. */
6590 && !PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx))
6591 && nargs - arg_idx != TREE_VEC_LENGTH (packed_types))
6594 = TREE_VEC_LENGTH (parms) - 1 + TREE_VEC_LENGTH (packed_types);
6595 error ("wrong number of template arguments (%d, should be %d)",
6596 nargs, needed_parms);
6597 return error_mark_node;
6600 /* If we aren't able to check the actual arguments now
6601 (because they haven't been expanded yet), we can at least
6602 verify that all of the types used for the non-type
6603 template parameter pack are, in fact, valid for non-type
6604 template parameters. */
6606 && PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx)))
6608 int j, len = TREE_VEC_LENGTH (packed_types);
6609 for (j = 0; j < len; ++j)
6611 tree t = TREE_VEC_ELT (packed_types, j);
6612 if (invalid_nontype_parm_type_p (t, complain))
6613 return error_mark_node;
6618 /* Convert the remaining arguments, which will be a part of the
6619 parameter pack "parm". */
6620 for (; arg_idx < nargs; ++arg_idx)
6622 tree arg = TREE_VEC_ELT (inner_args, arg_idx);
6623 tree actual_parm = TREE_VALUE (parm);
6625 if (packed_types && !PACK_EXPANSION_P (arg))
6627 /* When we have a vector of types (corresponding to the
6628 non-type template parameter pack that uses parameter
6629 packs in its type, as mention above), and the
6630 argument is not an expansion (which expands to a
6631 currently unknown number of arguments), clone the
6632 parm and give it the next type in PACKED_TYPES. */
6633 actual_parm = copy_node (actual_parm);
6634 TREE_TYPE (actual_parm) =
6635 TREE_VEC_ELT (packed_types, arg_idx - parm_idx);
6638 if (arg != error_mark_node)
6639 arg = convert_template_argument (actual_parm,
6640 arg, new_args, complain, parm_idx,
6642 if (arg == error_mark_node)
6644 TREE_VEC_ELT (packed_args, arg_idx - parm_idx) = arg;
6647 if (TREE_CODE (TREE_VALUE (parm)) == TYPE_DECL
6648 || TREE_CODE (TREE_VALUE (parm)) == TEMPLATE_DECL)
6649 argument_pack = cxx_make_type (TYPE_ARGUMENT_PACK);
6652 argument_pack = make_node (NONTYPE_ARGUMENT_PACK);
6653 TREE_TYPE (argument_pack)
6654 = tsubst (TREE_TYPE (TREE_VALUE (parm)), new_args, complain, in_decl);
6655 TREE_CONSTANT (argument_pack) = 1;
6658 SET_ARGUMENT_PACK_ARGS (argument_pack, packed_args);
6659 #ifdef ENABLE_CHECKING
6660 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (packed_args,
6661 TREE_VEC_LENGTH (packed_args));
6663 return argument_pack;
6666 /* Convert all template arguments to their appropriate types, and
6667 return a vector containing the innermost resulting template
6668 arguments. If any error occurs, return error_mark_node. Error and
6669 warning messages are issued under control of COMPLAIN.
6671 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6672 for arguments not specified in ARGS. Otherwise, if
6673 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6674 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6675 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6679 coerce_template_parms (tree parms,
6682 tsubst_flags_t complain,
6683 bool require_all_args,
6684 bool use_default_args)
6686 int nparms, nargs, parm_idx, arg_idx, lost = 0;
6689 tree new_inner_args;
6690 int saved_unevaluated_operand;
6691 int saved_inhibit_evaluation_warnings;
6693 /* When used as a boolean value, indicates whether this is a
6694 variadic template parameter list. Since it's an int, we can also
6695 subtract it from nparms to get the number of non-variadic
6698 int post_variadic_parms = 0;
6700 if (args == error_mark_node)
6701 return error_mark_node;
6703 nparms = TREE_VEC_LENGTH (parms);
6705 /* Determine if there are any parameter packs. */
6706 for (parm_idx = 0; parm_idx < nparms; ++parm_idx)
6708 tree tparm = TREE_VALUE (TREE_VEC_ELT (parms, parm_idx));
6710 ++post_variadic_parms;
6711 if (template_parameter_pack_p (tparm))
6715 inner_args = INNERMOST_TEMPLATE_ARGS (args);
6716 /* If there are no parameters that follow a parameter pack, we need to
6717 expand any argument packs so that we can deduce a parameter pack from
6718 some non-packed args followed by an argument pack, as in variadic85.C.
6719 If there are such parameters, we need to leave argument packs intact
6720 so the arguments are assigned properly. This can happen when dealing
6721 with a nested class inside a partial specialization of a class
6722 template, as in variadic92.C, or when deducing a template parameter pack
6723 from a sub-declarator, as in variadic114.C. */
6724 if (!post_variadic_parms)
6725 inner_args = expand_template_argument_pack (inner_args);
6727 nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
6728 if ((nargs > nparms && !variadic_p)
6729 || (nargs < nparms - variadic_p
6731 && (!use_default_args
6732 || (TREE_VEC_ELT (parms, nargs) != error_mark_node
6733 && !TREE_PURPOSE (TREE_VEC_ELT (parms, nargs))))))
6735 if (complain & tf_error)
6739 nparms -= variadic_p;
6740 error ("wrong number of template arguments "
6741 "(%d, should be %d or more)", nargs, nparms);
6744 error ("wrong number of template arguments "
6745 "(%d, should be %d)", nargs, nparms);
6748 error ("provided for %q+D", in_decl);
6751 return error_mark_node;
6754 /* We need to evaluate the template arguments, even though this
6755 template-id may be nested within a "sizeof". */
6756 saved_unevaluated_operand = cp_unevaluated_operand;
6757 cp_unevaluated_operand = 0;
6758 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
6759 c_inhibit_evaluation_warnings = 0;
6760 new_inner_args = make_tree_vec (nparms);
6761 new_args = add_outermost_template_args (args, new_inner_args);
6762 for (parm_idx = 0, arg_idx = 0; parm_idx < nparms; parm_idx++, arg_idx++)
6767 /* Get the Ith template parameter. */
6768 parm = TREE_VEC_ELT (parms, parm_idx);
6770 if (parm == error_mark_node)
6772 TREE_VEC_ELT (new_inner_args, arg_idx) = error_mark_node;
6776 /* Calculate the next argument. */
6777 if (arg_idx < nargs)
6778 arg = TREE_VEC_ELT (inner_args, arg_idx);
6782 if (template_parameter_pack_p (TREE_VALUE (parm))
6783 && !(arg && ARGUMENT_PACK_P (arg)))
6785 /* All remaining arguments will be placed in the
6786 template parameter pack PARM. */
6787 arg = coerce_template_parameter_pack (parms, parm_idx, args,
6788 inner_args, arg_idx,
6792 /* Store this argument. */
6793 if (arg == error_mark_node)
6795 TREE_VEC_ELT (new_inner_args, parm_idx) = arg;
6797 /* We are done with all of the arguments. */
6804 if (PACK_EXPANSION_P (arg))
6806 /* We don't know how many args we have yet, just
6807 use the unconverted ones for now. */
6808 new_inner_args = args;
6812 else if (require_all_args)
6814 /* There must be a default arg in this case. */
6815 arg = tsubst_template_arg (TREE_PURPOSE (parm), new_args,
6817 /* The position of the first default template argument,
6818 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6820 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args))
6821 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args, arg_idx);
6826 if (arg == error_mark_node)
6828 if (complain & tf_error)
6829 error ("template argument %d is invalid", arg_idx + 1);
6832 /* This only occurs if there was an error in the template
6833 parameter list itself (which we would already have
6834 reported) that we are trying to recover from, e.g., a class
6835 template with a parameter list such as
6836 template<typename..., typename>. */
6839 arg = convert_template_argument (TREE_VALUE (parm),
6840 arg, new_args, complain,
6843 if (arg == error_mark_node)
6845 TREE_VEC_ELT (new_inner_args, arg_idx) = arg;
6847 cp_unevaluated_operand = saved_unevaluated_operand;
6848 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
6851 return error_mark_node;
6853 #ifdef ENABLE_CHECKING
6854 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args))
6855 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args,
6856 TREE_VEC_LENGTH (new_inner_args));
6859 return new_inner_args;
6862 /* Returns 1 if template args OT and NT are equivalent. */
6865 template_args_equal (tree ot, tree nt)
6869 if (nt == NULL_TREE || ot == NULL_TREE)
6872 if (TREE_CODE (nt) == TREE_VEC)
6873 /* For member templates */
6874 return TREE_CODE (ot) == TREE_VEC && comp_template_args (ot, nt);
6875 else if (PACK_EXPANSION_P (ot))
6876 return PACK_EXPANSION_P (nt)
6877 && template_args_equal (PACK_EXPANSION_PATTERN (ot),
6878 PACK_EXPANSION_PATTERN (nt));
6879 else if (ARGUMENT_PACK_P (ot))
6884 if (!ARGUMENT_PACK_P (nt))
6887 opack = ARGUMENT_PACK_ARGS (ot);
6888 npack = ARGUMENT_PACK_ARGS (nt);
6889 len = TREE_VEC_LENGTH (opack);
6890 if (TREE_VEC_LENGTH (npack) != len)
6892 for (i = 0; i < len; ++i)
6893 if (!template_args_equal (TREE_VEC_ELT (opack, i),
6894 TREE_VEC_ELT (npack, i)))
6898 else if (ot && TREE_CODE (ot) == ARGUMENT_PACK_SELECT)
6900 /* We get here probably because we are in the middle of substituting
6901 into the pattern of a pack expansion. In that case the
6902 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
6903 interested in. So we want to use the initial pack argument for
6905 ot = ARGUMENT_PACK_SELECT_FROM_PACK (ot);
6906 if (nt && TREE_CODE (nt) == ARGUMENT_PACK_SELECT)
6907 nt = ARGUMENT_PACK_SELECT_FROM_PACK (nt);
6908 return template_args_equal (ot, nt);
6910 else if (TYPE_P (nt))
6911 return TYPE_P (ot) && same_type_p (ot, nt);
6912 else if (TREE_CODE (ot) == TREE_VEC || TYPE_P (ot))
6915 return cp_tree_equal (ot, nt);
6918 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
6919 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
6920 NEWARG_PTR with the offending arguments if they are non-NULL. */
6923 comp_template_args_with_info (tree oldargs, tree newargs,
6924 tree *oldarg_ptr, tree *newarg_ptr)
6928 if (TREE_VEC_LENGTH (oldargs) != TREE_VEC_LENGTH (newargs))
6931 for (i = 0; i < TREE_VEC_LENGTH (oldargs); ++i)
6933 tree nt = TREE_VEC_ELT (newargs, i);
6934 tree ot = TREE_VEC_ELT (oldargs, i);
6936 if (! template_args_equal (ot, nt))
6938 if (oldarg_ptr != NULL)
6940 if (newarg_ptr != NULL)
6948 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
6949 of template arguments. Returns 0 otherwise. */
6952 comp_template_args (tree oldargs, tree newargs)
6954 return comp_template_args_with_info (oldargs, newargs, NULL, NULL);
6958 add_pending_template (tree d)
6960 tree ti = (TYPE_P (d)
6961 ? CLASSTYPE_TEMPLATE_INFO (d)
6962 : DECL_TEMPLATE_INFO (d));
6963 struct pending_template *pt;
6966 if (TI_PENDING_TEMPLATE_FLAG (ti))
6969 /* We are called both from instantiate_decl, where we've already had a
6970 tinst_level pushed, and instantiate_template, where we haven't.
6972 level = !current_tinst_level || current_tinst_level->decl != d;
6975 push_tinst_level (d);
6977 pt = ggc_alloc_pending_template ();
6979 pt->tinst = current_tinst_level;
6980 if (last_pending_template)
6981 last_pending_template->next = pt;
6983 pending_templates = pt;
6985 last_pending_template = pt;
6987 TI_PENDING_TEMPLATE_FLAG (ti) = 1;
6994 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
6995 ARGLIST. Valid choices for FNS are given in the cp-tree.def
6996 documentation for TEMPLATE_ID_EXPR. */
6999 lookup_template_function (tree fns, tree arglist)
7003 if (fns == error_mark_node || arglist == error_mark_node)
7004 return error_mark_node;
7006 gcc_assert (!arglist || TREE_CODE (arglist) == TREE_VEC);
7008 if (!is_overloaded_fn (fns) && TREE_CODE (fns) != IDENTIFIER_NODE)
7010 error ("%q#D is not a function template", fns);
7011 return error_mark_node;
7014 if (BASELINK_P (fns))
7016 BASELINK_FUNCTIONS (fns) = build2 (TEMPLATE_ID_EXPR,
7018 BASELINK_FUNCTIONS (fns),
7023 type = TREE_TYPE (fns);
7024 if (TREE_CODE (fns) == OVERLOAD || !type)
7025 type = unknown_type_node;
7027 return build2 (TEMPLATE_ID_EXPR, type, fns, arglist);
7030 /* Within the scope of a template class S<T>, the name S gets bound
7031 (in build_self_reference) to a TYPE_DECL for the class, not a
7032 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
7033 or one of its enclosing classes, and that type is a template,
7034 return the associated TEMPLATE_DECL. Otherwise, the original
7037 Also handle the case when DECL is a TREE_LIST of ambiguous
7038 injected-class-names from different bases. */
7041 maybe_get_template_decl_from_type_decl (tree decl)
7043 if (decl == NULL_TREE)
7046 /* DR 176: A lookup that finds an injected-class-name (10.2
7047 [class.member.lookup]) can result in an ambiguity in certain cases
7048 (for example, if it is found in more than one base class). If all of
7049 the injected-class-names that are found refer to specializations of
7050 the same class template, and if the name is followed by a
7051 template-argument-list, the reference refers to the class template
7052 itself and not a specialization thereof, and is not ambiguous. */
7053 if (TREE_CODE (decl) == TREE_LIST)
7055 tree t, tmpl = NULL_TREE;
7056 for (t = decl; t; t = TREE_CHAIN (t))
7058 tree elt = maybe_get_template_decl_from_type_decl (TREE_VALUE (t));
7061 else if (tmpl != elt)
7064 if (tmpl && t == NULL_TREE)
7070 return (decl != NULL_TREE
7071 && DECL_SELF_REFERENCE_P (decl)
7072 && CLASSTYPE_TEMPLATE_INFO (TREE_TYPE (decl)))
7073 ? CLASSTYPE_TI_TEMPLATE (TREE_TYPE (decl)) : decl;
7076 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
7077 parameters, find the desired type.
7079 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
7081 IN_DECL, if non-NULL, is the template declaration we are trying to
7084 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
7085 the class we are looking up.
7087 Issue error and warning messages under control of COMPLAIN.
7089 If the template class is really a local class in a template
7090 function, then the FUNCTION_CONTEXT is the function in which it is
7093 ??? Note that this function is currently called *twice* for each
7094 template-id: the first time from the parser, while creating the
7095 incomplete type (finish_template_type), and the second type during the
7096 real instantiation (instantiate_template_class). This is surely something
7097 that we want to avoid. It also causes some problems with argument
7098 coercion (see convert_nontype_argument for more information on this). */
7101 lookup_template_class_1 (tree d1, tree arglist, tree in_decl, tree context,
7102 int entering_scope, tsubst_flags_t complain)
7104 tree templ = NULL_TREE, parmlist;
7111 if (TREE_CODE (d1) == IDENTIFIER_NODE)
7113 tree value = innermost_non_namespace_value (d1);
7114 if (value && DECL_TEMPLATE_TEMPLATE_PARM_P (value))
7119 push_decl_namespace (context);
7120 templ = lookup_name (d1);
7121 templ = maybe_get_template_decl_from_type_decl (templ);
7123 pop_decl_namespace ();
7126 context = DECL_CONTEXT (templ);
7128 else if (TREE_CODE (d1) == TYPE_DECL && MAYBE_CLASS_TYPE_P (TREE_TYPE (d1)))
7130 tree type = TREE_TYPE (d1);
7132 /* If we are declaring a constructor, say A<T>::A<T>, we will get
7133 an implicit typename for the second A. Deal with it. */
7134 if (TREE_CODE (type) == TYPENAME_TYPE && TREE_TYPE (type))
7135 type = TREE_TYPE (type);
7137 if (CLASSTYPE_TEMPLATE_INFO (type))
7139 templ = CLASSTYPE_TI_TEMPLATE (type);
7140 d1 = DECL_NAME (templ);
7143 else if (TREE_CODE (d1) == ENUMERAL_TYPE
7144 || (TYPE_P (d1) && MAYBE_CLASS_TYPE_P (d1)))
7146 templ = TYPE_TI_TEMPLATE (d1);
7147 d1 = DECL_NAME (templ);
7149 else if (TREE_CODE (d1) == TEMPLATE_DECL
7150 && DECL_TEMPLATE_RESULT (d1)
7151 && TREE_CODE (DECL_TEMPLATE_RESULT (d1)) == TYPE_DECL)
7154 d1 = DECL_NAME (templ);
7155 context = DECL_CONTEXT (templ);
7158 /* Issue an error message if we didn't find a template. */
7161 if (complain & tf_error)
7162 error ("%qT is not a template", d1);
7163 return error_mark_node;
7166 if (TREE_CODE (templ) != TEMPLATE_DECL
7167 /* Make sure it's a user visible template, if it was named by
7169 || ((complain & tf_user) && !DECL_TEMPLATE_PARM_P (templ)
7170 && !PRIMARY_TEMPLATE_P (templ)))
7172 if (complain & tf_error)
7174 error ("non-template type %qT used as a template", d1);
7176 error ("for template declaration %q+D", in_decl);
7178 return error_mark_node;
7181 complain &= ~tf_user;
7183 if (DECL_TEMPLATE_TEMPLATE_PARM_P (templ))
7185 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
7186 template arguments */
7192 parmlist = DECL_INNERMOST_TEMPLATE_PARMS (templ);
7194 /* Consider an example where a template template parameter declared as
7196 template <class T, class U = std::allocator<T> > class TT
7198 The template parameter level of T and U are one level larger than
7199 of TT. To proper process the default argument of U, say when an
7200 instantiation `TT<int>' is seen, we need to build the full
7201 arguments containing {int} as the innermost level. Outer levels,
7202 available when not appearing as default template argument, can be
7203 obtained from the arguments of the enclosing template.
7205 Suppose that TT is later substituted with std::vector. The above
7206 instantiation is `TT<int, std::allocator<T> >' with TT at
7207 level 1, and T at level 2, while the template arguments at level 1
7208 becomes {std::vector} and the inner level 2 is {int}. */
7210 outer = DECL_CONTEXT (templ);
7212 outer = TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (outer)));
7213 else if (current_template_parms)
7214 /* This is an argument of the current template, so we haven't set
7215 DECL_CONTEXT yet. */
7216 outer = current_template_args ();
7219 arglist = add_to_template_args (outer, arglist);
7221 arglist2 = coerce_template_parms (parmlist, arglist, templ,
7223 /*require_all_args=*/true,
7224 /*use_default_args=*/true);
7225 if (arglist2 == error_mark_node
7226 || (!uses_template_parms (arglist2)
7227 && check_instantiated_args (templ, arglist2, complain)))
7228 return error_mark_node;
7230 parm = bind_template_template_parm (TREE_TYPE (templ), arglist2);
7235 tree template_type = TREE_TYPE (templ);
7238 tree found = NULL_TREE;
7241 int is_dependent_type;
7242 int use_partial_inst_tmpl = false;
7244 gen_tmpl = most_general_template (templ);
7245 parmlist = DECL_TEMPLATE_PARMS (gen_tmpl);
7246 parm_depth = TMPL_PARMS_DEPTH (parmlist);
7247 arg_depth = TMPL_ARGS_DEPTH (arglist);
7249 if (arg_depth == 1 && parm_depth > 1)
7251 /* We've been given an incomplete set of template arguments.
7254 template <class T> struct S1 {
7255 template <class U> struct S2 {};
7256 template <class U> struct S2<U*> {};
7259 we will be called with an ARGLIST of `U*', but the
7260 TEMPLATE will be `template <class T> template
7261 <class U> struct S1<T>::S2'. We must fill in the missing
7264 = add_outermost_template_args (TYPE_TI_ARGS (TREE_TYPE (templ)),
7266 arg_depth = TMPL_ARGS_DEPTH (arglist);
7269 /* Now we should have enough arguments. */
7270 gcc_assert (parm_depth == arg_depth);
7272 /* From here on, we're only interested in the most general
7275 /* Calculate the BOUND_ARGS. These will be the args that are
7276 actually tsubst'd into the definition to create the
7280 /* We have multiple levels of arguments to coerce, at once. */
7282 int saved_depth = TMPL_ARGS_DEPTH (arglist);
7284 tree bound_args = make_tree_vec (parm_depth);
7286 for (i = saved_depth,
7287 t = DECL_TEMPLATE_PARMS (gen_tmpl);
7288 i > 0 && t != NULL_TREE;
7289 --i, t = TREE_CHAIN (t))
7292 if (i == saved_depth)
7293 a = coerce_template_parms (TREE_VALUE (t),
7296 /*require_all_args=*/true,
7297 /*use_default_args=*/true);
7299 /* Outer levels should have already been coerced. */
7300 a = TMPL_ARGS_LEVEL (arglist, i);
7302 /* Don't process further if one of the levels fails. */
7303 if (a == error_mark_node)
7305 /* Restore the ARGLIST to its full size. */
7306 TREE_VEC_LENGTH (arglist) = saved_depth;
7307 return error_mark_node;
7310 SET_TMPL_ARGS_LEVEL (bound_args, i, a);
7312 /* We temporarily reduce the length of the ARGLIST so
7313 that coerce_template_parms will see only the arguments
7314 corresponding to the template parameters it is
7316 TREE_VEC_LENGTH (arglist)--;
7319 /* Restore the ARGLIST to its full size. */
7320 TREE_VEC_LENGTH (arglist) = saved_depth;
7322 arglist = bound_args;
7326 = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parmlist),
7327 INNERMOST_TEMPLATE_ARGS (arglist),
7330 /*require_all_args=*/true,
7331 /*use_default_args=*/true);
7333 if (arglist == error_mark_node)
7334 /* We were unable to bind the arguments. */
7335 return error_mark_node;
7337 /* In the scope of a template class, explicit references to the
7338 template class refer to the type of the template, not any
7339 instantiation of it. For example, in:
7341 template <class T> class C { void f(C<T>); }
7343 the `C<T>' is just the same as `C'. Outside of the
7344 class, however, such a reference is an instantiation. */
7346 || !PRIMARY_TEMPLATE_P (gen_tmpl)
7347 || currently_open_class (template_type))
7348 /* comp_template_args is expensive, check it last. */
7349 && comp_template_args (TYPE_TI_ARGS (template_type),
7351 return template_type;
7353 /* If we already have this specialization, return it. */
7354 elt.tmpl = gen_tmpl;
7356 hash = hash_specialization (&elt);
7357 entry = (spec_entry *) htab_find_with_hash (type_specializations,
7363 is_dependent_type = uses_template_parms (arglist);
7365 /* If the deduced arguments are invalid, then the binding
7367 if (!is_dependent_type
7368 && check_instantiated_args (gen_tmpl,
7369 INNERMOST_TEMPLATE_ARGS (arglist),
7371 return error_mark_node;
7373 if (!is_dependent_type
7374 && !PRIMARY_TEMPLATE_P (gen_tmpl)
7375 && !LAMBDA_TYPE_P (TREE_TYPE (gen_tmpl))
7376 && TREE_CODE (CP_DECL_CONTEXT (gen_tmpl)) == NAMESPACE_DECL)
7378 found = xref_tag_from_type (TREE_TYPE (gen_tmpl),
7379 DECL_NAME (gen_tmpl),
7380 /*tag_scope=*/ts_global);
7384 context = tsubst (DECL_CONTEXT (gen_tmpl), arglist,
7387 context = global_namespace;
7389 /* Create the type. */
7390 if (TREE_CODE (template_type) == ENUMERAL_TYPE)
7392 if (!is_dependent_type)
7394 set_current_access_from_decl (TYPE_NAME (template_type));
7395 t = start_enum (TYPE_IDENTIFIER (template_type), NULL_TREE,
7396 tsubst (ENUM_UNDERLYING_TYPE (template_type),
7397 arglist, complain, in_decl),
7398 SCOPED_ENUM_P (template_type), NULL);
7402 /* We don't want to call start_enum for this type, since
7403 the values for the enumeration constants may involve
7404 template parameters. And, no one should be interested
7405 in the enumeration constants for such a type. */
7406 t = cxx_make_type (ENUMERAL_TYPE);
7407 SET_SCOPED_ENUM_P (t, SCOPED_ENUM_P (template_type));
7409 SET_OPAQUE_ENUM_P (t, OPAQUE_ENUM_P (template_type));
7410 ENUM_FIXED_UNDERLYING_TYPE_P (t)
7411 = ENUM_FIXED_UNDERLYING_TYPE_P (template_type);
7413 else if (DECL_ALIAS_TEMPLATE_P (gen_tmpl))
7415 /* The user referred to a specialization of an alias
7416 template represented by GEN_TMPL.
7418 [temp.alias]/2 says:
7420 When a template-id refers to the specialization of an
7421 alias template, it is equivalent to the associated
7422 type obtained by substitution of its
7423 template-arguments for the template-parameters in the
7424 type-id of the alias template. */
7426 t = tsubst (TREE_TYPE (gen_tmpl), arglist, complain, in_decl);
7427 /* Note that the call above (by indirectly calling
7428 register_specialization in tsubst_decl) registers the
7429 TYPE_DECL representing the specialization of the alias
7430 template. So next time someone substitutes ARGLIST for
7431 the template parms into the alias template (GEN_TMPL),
7432 she'll get that TYPE_DECL back. */
7434 if (t == error_mark_node)
7437 else if (CLASS_TYPE_P (template_type))
7439 t = make_class_type (TREE_CODE (template_type));
7440 CLASSTYPE_DECLARED_CLASS (t)
7441 = CLASSTYPE_DECLARED_CLASS (template_type);
7442 SET_CLASSTYPE_IMPLICIT_INSTANTIATION (t);
7443 TYPE_FOR_JAVA (t) = TYPE_FOR_JAVA (template_type);
7445 /* A local class. Make sure the decl gets registered properly. */
7446 if (context == current_function_decl)
7447 pushtag (DECL_NAME (gen_tmpl), t, /*tag_scope=*/ts_current);
7449 if (comp_template_args (CLASSTYPE_TI_ARGS (template_type), arglist))
7450 /* This instantiation is another name for the primary
7451 template type. Set the TYPE_CANONICAL field
7453 TYPE_CANONICAL (t) = template_type;
7454 else if (any_template_arguments_need_structural_equality_p (arglist))
7455 /* Some of the template arguments require structural
7456 equality testing, so this template class requires
7457 structural equality testing. */
7458 SET_TYPE_STRUCTURAL_EQUALITY (t);
7463 /* If we called start_enum or pushtag above, this information
7464 will already be set up. */
7467 TYPE_CONTEXT (t) = FROB_CONTEXT (context);
7469 type_decl = create_implicit_typedef (DECL_NAME (gen_tmpl), t);
7470 DECL_CONTEXT (type_decl) = TYPE_CONTEXT (t);
7471 DECL_SOURCE_LOCATION (type_decl)
7472 = DECL_SOURCE_LOCATION (TYPE_STUB_DECL (template_type));
7475 type_decl = TYPE_NAME (t);
7477 if (CLASS_TYPE_P (template_type))
7479 TREE_PRIVATE (type_decl)
7480 = TREE_PRIVATE (TYPE_STUB_DECL (template_type));
7481 TREE_PROTECTED (type_decl)
7482 = TREE_PROTECTED (TYPE_STUB_DECL (template_type));
7483 if (CLASSTYPE_VISIBILITY_SPECIFIED (template_type))
7485 DECL_VISIBILITY_SPECIFIED (type_decl) = 1;
7486 DECL_VISIBILITY (type_decl) = CLASSTYPE_VISIBILITY (template_type);
7490 /* Let's consider the explicit specialization of a member
7491 of a class template specialization that is implicitely instantiated,
7496 template<class U> struct M {}; //#0
7501 struct S<int>::M<char> //#1
7505 [temp.expl.spec]/4 says this is valid.
7507 In this case, when we write:
7510 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7513 When we encounter #1, we want to store the partial instantiation
7514 of M (template<class T> S<int>::M<T>) in it's CLASSTYPE_TI_TEMPLATE.
7516 For all cases other than this "explicit specialization of member of a
7517 class template", we just want to store the most general template into
7518 the CLASSTYPE_TI_TEMPLATE of M.
7520 This case of "explicit specialization of member of a class template"
7522 1/ the enclosing class is an instantiation of, and therefore not
7523 the same as, the context of the most general template, and
7524 2/ we aren't looking at the partial instantiation itself, i.e.
7525 the innermost arguments are not the same as the innermost parms of
7526 the most general template.
7528 So it's only when 1/ and 2/ happens that we want to use the partial
7529 instantiation of the member template in lieu of its most general
7532 if (PRIMARY_TEMPLATE_P (gen_tmpl)
7533 && TMPL_ARGS_HAVE_MULTIPLE_LEVELS (arglist)
7534 /* the enclosing class must be an instantiation... */
7535 && CLASS_TYPE_P (context)
7536 && !same_type_p (context, DECL_CONTEXT (gen_tmpl)))
7538 tree partial_inst_args;
7539 TREE_VEC_LENGTH (arglist)--;
7540 ++processing_template_decl;
7542 tsubst (INNERMOST_TEMPLATE_ARGS
7543 (TYPE_TI_ARGS (TREE_TYPE (gen_tmpl))),
7544 arglist, complain, NULL_TREE);
7545 --processing_template_decl;
7546 TREE_VEC_LENGTH (arglist)++;
7547 use_partial_inst_tmpl =
7548 /*...and we must not be looking at the partial instantiation
7550 !comp_template_args (INNERMOST_TEMPLATE_ARGS (arglist),
7554 if (!use_partial_inst_tmpl)
7555 /* This case is easy; there are no member templates involved. */
7559 /* This is a full instantiation of a member template. Find
7560 the partial instantiation of which this is an instance. */
7562 /* Temporarily reduce by one the number of levels in the ARGLIST
7563 so as to avoid comparing the last set of arguments. */
7564 TREE_VEC_LENGTH (arglist)--;
7565 found = tsubst (gen_tmpl, arglist, complain, NULL_TREE);
7566 TREE_VEC_LENGTH (arglist)++;
7567 /* FOUND is either a proper class type, or an alias
7568 template specialization. In the later case, it's a
7569 TYPE_DECL, resulting from the substituting of arguments
7570 for parameters in the TYPE_DECL of the alias template
7571 done earlier. So be careful while getting the template
7573 found = TREE_CODE (found) == TYPE_DECL
7574 ? TYPE_TI_TEMPLATE (TREE_TYPE (found))
7575 : CLASSTYPE_TI_TEMPLATE (found);
7578 SET_TYPE_TEMPLATE_INFO (t, build_template_info (found, arglist));
7581 slot = htab_find_slot_with_hash (type_specializations,
7582 &elt, hash, INSERT);
7583 entry = ggc_alloc_spec_entry ();
7587 /* Note this use of the partial instantiation so we can check it
7588 later in maybe_process_partial_specialization. */
7589 DECL_TEMPLATE_INSTANTIATIONS (templ)
7590 = tree_cons (arglist, t,
7591 DECL_TEMPLATE_INSTANTIATIONS (templ));
7593 if (TREE_CODE (t) == ENUMERAL_TYPE && !is_dependent_type)
7594 /* Now that the type has been registered on the instantiations
7595 list, we set up the enumerators. Because the enumeration
7596 constants may involve the enumeration type itself, we make
7597 sure to register the type first, and then create the
7598 constants. That way, doing tsubst_expr for the enumeration
7599 constants won't result in recursive calls here; we'll find
7600 the instantiation and exit above. */
7601 tsubst_enum (template_type, t, arglist);
7603 if (CLASS_TYPE_P (template_type) && is_dependent_type)
7604 /* If the type makes use of template parameters, the
7605 code that generates debugging information will crash. */
7606 DECL_IGNORED_P (TYPE_STUB_DECL (t)) = 1;
7608 /* Possibly limit visibility based on template args. */
7609 TREE_PUBLIC (type_decl) = 1;
7610 determine_visibility (type_decl);
7616 /* Wrapper for lookup_template_class_1. */
7619 lookup_template_class (tree d1, tree arglist, tree in_decl, tree context,
7620 int entering_scope, tsubst_flags_t complain)
7623 timevar_push (TV_TEMPLATE_INST);
7624 ret = lookup_template_class_1 (d1, arglist, in_decl, context,
7625 entering_scope, complain);
7626 timevar_pop (TV_TEMPLATE_INST);
7634 /* True when we should also visit template parameters that occur in
7635 non-deduced contexts. */
7636 bool include_nondeduced_p;
7637 struct pointer_set_t *visited;
7640 /* Called from for_each_template_parm via walk_tree. */
7643 for_each_template_parm_r (tree *tp, int *walk_subtrees, void *d)
7646 struct pair_fn_data *pfd = (struct pair_fn_data *) d;
7647 tree_fn_t fn = pfd->fn;
7648 void *data = pfd->data;
7651 && (pfd->include_nondeduced_p || TREE_CODE (t) != TYPENAME_TYPE)
7652 && for_each_template_parm (TYPE_CONTEXT (t), fn, data, pfd->visited,
7653 pfd->include_nondeduced_p))
7654 return error_mark_node;
7656 switch (TREE_CODE (t))
7659 if (TYPE_PTRMEMFUNC_P (t))
7665 if (!TYPE_TEMPLATE_INFO (t))
7667 else if (for_each_template_parm (TI_ARGS (TYPE_TEMPLATE_INFO (t)),
7668 fn, data, pfd->visited,
7669 pfd->include_nondeduced_p))
7670 return error_mark_node;
7674 if (for_each_template_parm (TYPE_MIN_VALUE (t),
7675 fn, data, pfd->visited,
7676 pfd->include_nondeduced_p)
7677 || for_each_template_parm (TYPE_MAX_VALUE (t),
7678 fn, data, pfd->visited,
7679 pfd->include_nondeduced_p))
7680 return error_mark_node;
7684 /* Since we're not going to walk subtrees, we have to do this
7686 if (for_each_template_parm (TYPE_METHOD_BASETYPE (t), fn, data,
7687 pfd->visited, pfd->include_nondeduced_p))
7688 return error_mark_node;
7692 /* Check the return type. */
7693 if (for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
7694 pfd->include_nondeduced_p))
7695 return error_mark_node;
7697 /* Check the parameter types. Since default arguments are not
7698 instantiated until they are needed, the TYPE_ARG_TYPES may
7699 contain expressions that involve template parameters. But,
7700 no-one should be looking at them yet. And, once they're
7701 instantiated, they don't contain template parameters, so
7702 there's no point in looking at them then, either. */
7706 for (parm = TYPE_ARG_TYPES (t); parm; parm = TREE_CHAIN (parm))
7707 if (for_each_template_parm (TREE_VALUE (parm), fn, data,
7708 pfd->visited, pfd->include_nondeduced_p))
7709 return error_mark_node;
7711 /* Since we've already handled the TYPE_ARG_TYPES, we don't
7712 want walk_tree walking into them itself. */
7718 case UNDERLYING_TYPE:
7719 if (pfd->include_nondeduced_p
7720 && for_each_template_parm (TYPE_FIELDS (t), fn, data,
7722 pfd->include_nondeduced_p))
7723 return error_mark_node;
7728 if (DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t)
7729 && for_each_template_parm (DECL_TI_ARGS (t), fn, data,
7730 pfd->visited, pfd->include_nondeduced_p))
7731 return error_mark_node;
7736 if (TREE_CODE (t) == CONST_DECL && DECL_TEMPLATE_PARM_P (t)
7737 && for_each_template_parm (DECL_INITIAL (t), fn, data,
7738 pfd->visited, pfd->include_nondeduced_p))
7739 return error_mark_node;
7740 if (DECL_CONTEXT (t)
7741 && pfd->include_nondeduced_p
7742 && for_each_template_parm (DECL_CONTEXT (t), fn, data,
7743 pfd->visited, pfd->include_nondeduced_p))
7744 return error_mark_node;
7747 case BOUND_TEMPLATE_TEMPLATE_PARM:
7748 /* Record template parameters such as `T' inside `TT<T>'. */
7749 if (for_each_template_parm (TYPE_TI_ARGS (t), fn, data, pfd->visited,
7750 pfd->include_nondeduced_p))
7751 return error_mark_node;
7754 case TEMPLATE_TEMPLATE_PARM:
7755 case TEMPLATE_TYPE_PARM:
7756 case TEMPLATE_PARM_INDEX:
7757 if (fn && (*fn)(t, data))
7758 return error_mark_node;
7760 return error_mark_node;
7764 /* A template template parameter is encountered. */
7765 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t)
7766 && for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
7767 pfd->include_nondeduced_p))
7768 return error_mark_node;
7770 /* Already substituted template template parameter */
7776 || for_each_template_parm (TYPENAME_TYPE_FULLNAME (t), fn,
7778 pfd->include_nondeduced_p))
7779 return error_mark_node;
7783 if (TREE_TYPE (t) && TYPE_PTRMEMFUNC_P (TREE_TYPE (t))
7784 && pfd->include_nondeduced_p
7785 && for_each_template_parm (TYPE_PTRMEMFUNC_FN_TYPE
7786 (TREE_TYPE (t)), fn, data,
7787 pfd->visited, pfd->include_nondeduced_p))
7788 return error_mark_node;
7793 /* If there's no type, then this thing must be some expression
7794 involving template parameters. */
7795 if (!fn && !TREE_TYPE (t))
7796 return error_mark_node;
7801 case IMPLICIT_CONV_EXPR:
7802 case REINTERPRET_CAST_EXPR:
7803 case CONST_CAST_EXPR:
7804 case STATIC_CAST_EXPR:
7805 case DYNAMIC_CAST_EXPR:
7809 case PSEUDO_DTOR_EXPR:
7811 return error_mark_node;
7818 /* We didn't find any template parameters we liked. */
7822 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
7823 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
7824 call FN with the parameter and the DATA.
7825 If FN returns nonzero, the iteration is terminated, and
7826 for_each_template_parm returns 1. Otherwise, the iteration
7827 continues. If FN never returns a nonzero value, the value
7828 returned by for_each_template_parm is 0. If FN is NULL, it is
7829 considered to be the function which always returns 1.
7831 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
7832 parameters that occur in non-deduced contexts. When false, only
7833 visits those template parameters that can be deduced. */
7836 for_each_template_parm (tree t, tree_fn_t fn, void* data,
7837 struct pointer_set_t *visited,
7838 bool include_nondeduced_p)
7840 struct pair_fn_data pfd;
7846 pfd.include_nondeduced_p = include_nondeduced_p;
7848 /* Walk the tree. (Conceptually, we would like to walk without
7849 duplicates, but for_each_template_parm_r recursively calls
7850 for_each_template_parm, so we would need to reorganize a fair
7851 bit to use walk_tree_without_duplicates, so we keep our own
7854 pfd.visited = visited;
7856 pfd.visited = pointer_set_create ();
7857 result = cp_walk_tree (&t,
7858 for_each_template_parm_r,
7860 pfd.visited) != NULL_TREE;
7865 pointer_set_destroy (pfd.visited);
7872 /* Returns true if T depends on any template parameter. */
7875 uses_template_parms (tree t)
7878 int saved_processing_template_decl;
7880 saved_processing_template_decl = processing_template_decl;
7881 if (!saved_processing_template_decl)
7882 processing_template_decl = 1;
7884 dependent_p = dependent_type_p (t);
7885 else if (TREE_CODE (t) == TREE_VEC)
7886 dependent_p = any_dependent_template_arguments_p (t);
7887 else if (TREE_CODE (t) == TREE_LIST)
7888 dependent_p = (uses_template_parms (TREE_VALUE (t))
7889 || uses_template_parms (TREE_CHAIN (t)));
7890 else if (TREE_CODE (t) == TYPE_DECL)
7891 dependent_p = dependent_type_p (TREE_TYPE (t));
7894 || TREE_CODE (t) == TEMPLATE_PARM_INDEX
7895 || TREE_CODE (t) == OVERLOAD
7897 || TREE_CODE (t) == IDENTIFIER_NODE
7898 || TREE_CODE (t) == TRAIT_EXPR
7899 || TREE_CODE (t) == CONSTRUCTOR
7900 || CONSTANT_CLASS_P (t))
7901 dependent_p = (type_dependent_expression_p (t)
7902 || value_dependent_expression_p (t));
7905 gcc_assert (t == error_mark_node);
7906 dependent_p = false;
7909 processing_template_decl = saved_processing_template_decl;
7914 /* Returns true if T depends on any template parameter with level LEVEL. */
7917 uses_template_parms_level (tree t, int level)
7919 return for_each_template_parm (t, template_parm_this_level_p, &level, NULL,
7920 /*include_nondeduced_p=*/true);
7923 /* Returns TRUE iff INST is an instantiation we don't need to do in an
7924 ill-formed translation unit, i.e. a variable or function that isn't
7925 usable in a constant expression. */
7928 neglectable_inst_p (tree d)
7931 && !(TREE_CODE (d) == FUNCTION_DECL ? DECL_DECLARED_CONSTEXPR_P (d)
7932 : decl_maybe_constant_var_p (d)));
7935 /* Returns TRUE iff we should refuse to instantiate DECL because it's
7936 neglectable and instantiated from within an erroneous instantiation. */
7939 limit_bad_template_recursion (tree decl)
7941 struct tinst_level *lev = current_tinst_level;
7942 int errs = errorcount + sorrycount;
7943 if (lev == NULL || errs == 0 || !neglectable_inst_p (decl))
7946 for (; lev; lev = lev->next)
7947 if (neglectable_inst_p (lev->decl))
7950 return (lev && errs > lev->errors);
7953 static int tinst_depth;
7954 extern int max_tinst_depth;
7955 #ifdef GATHER_STATISTICS
7958 static GTY(()) struct tinst_level *last_error_tinst_level;
7960 /* We're starting to instantiate D; record the template instantiation context
7961 for diagnostics and to restore it later. */
7964 push_tinst_level (tree d)
7966 struct tinst_level *new_level;
7968 if (tinst_depth >= max_tinst_depth)
7970 last_error_tinst_level = current_tinst_level;
7971 if (TREE_CODE (d) == TREE_LIST)
7972 error ("template instantiation depth exceeds maximum of %d (use "
7973 "-ftemplate-depth= to increase the maximum) substituting %qS",
7974 max_tinst_depth, d);
7976 error ("template instantiation depth exceeds maximum of %d (use "
7977 "-ftemplate-depth= to increase the maximum) instantiating %qD",
7978 max_tinst_depth, d);
7980 print_instantiation_context ();
7985 /* If the current instantiation caused problems, don't let it instantiate
7986 anything else. Do allow deduction substitution and decls usable in
7987 constant expressions. */
7988 if (limit_bad_template_recursion (d))
7991 new_level = ggc_alloc_tinst_level ();
7992 new_level->decl = d;
7993 new_level->locus = input_location;
7994 new_level->errors = errorcount+sorrycount;
7995 new_level->in_system_header_p = in_system_header;
7996 new_level->next = current_tinst_level;
7997 current_tinst_level = new_level;
8000 #ifdef GATHER_STATISTICS
8001 if (tinst_depth > depth_reached)
8002 depth_reached = tinst_depth;
8008 /* We're done instantiating this template; return to the instantiation
8012 pop_tinst_level (void)
8014 /* Restore the filename and line number stashed away when we started
8015 this instantiation. */
8016 input_location = current_tinst_level->locus;
8017 current_tinst_level = current_tinst_level->next;
8021 /* We're instantiating a deferred template; restore the template
8022 instantiation context in which the instantiation was requested, which
8023 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
8026 reopen_tinst_level (struct tinst_level *level)
8028 struct tinst_level *t;
8031 for (t = level; t; t = t->next)
8034 current_tinst_level = level;
8036 if (current_tinst_level)
8037 current_tinst_level->errors = errorcount+sorrycount;
8041 /* Returns the TINST_LEVEL which gives the original instantiation
8044 struct tinst_level *
8045 outermost_tinst_level (void)
8047 struct tinst_level *level = current_tinst_level;
8050 level = level->next;
8054 /* Returns TRUE if PARM is a parameter of the template TEMPL. */
8057 parameter_of_template_p (tree parm, tree templ)
8062 if (!parm || !templ)
8065 gcc_assert (DECL_TEMPLATE_PARM_P (parm));
8066 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
8068 parms = DECL_TEMPLATE_PARMS (templ);
8069 parms = INNERMOST_TEMPLATE_PARMS (parms);
8071 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
8073 tree p = TREE_VALUE (TREE_VEC_ELT (parms, i));
8075 || (DECL_INITIAL (parm)
8076 && DECL_INITIAL (parm) == DECL_INITIAL (p)))
8083 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
8084 vector of template arguments, as for tsubst.
8086 Returns an appropriate tsubst'd friend declaration. */
8089 tsubst_friend_function (tree decl, tree args)
8093 if (TREE_CODE (decl) == FUNCTION_DECL
8094 && DECL_TEMPLATE_INSTANTIATION (decl)
8095 && TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
8096 /* This was a friend declared with an explicit template
8097 argument list, e.g.:
8101 to indicate that f was a template instantiation, not a new
8102 function declaration. Now, we have to figure out what
8103 instantiation of what template. */
8105 tree template_id, arglist, fns;
8108 tree ns = decl_namespace_context (TYPE_MAIN_DECL (current_class_type));
8110 /* Friend functions are looked up in the containing namespace scope.
8111 We must enter that scope, to avoid finding member functions of the
8112 current class with same name. */
8113 push_nested_namespace (ns);
8114 fns = tsubst_expr (DECL_TI_TEMPLATE (decl), args,
8115 tf_warning_or_error, NULL_TREE,
8116 /*integral_constant_expression_p=*/false);
8117 pop_nested_namespace (ns);
8118 arglist = tsubst (DECL_TI_ARGS (decl), args,
8119 tf_warning_or_error, NULL_TREE);
8120 template_id = lookup_template_function (fns, arglist);
8122 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
8123 tmpl = determine_specialization (template_id, new_friend,
8125 /*need_member_template=*/0,
8126 TREE_VEC_LENGTH (args),
8128 return instantiate_template (tmpl, new_args, tf_error);
8131 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
8133 /* The NEW_FRIEND will look like an instantiation, to the
8134 compiler, but is not an instantiation from the point of view of
8135 the language. For example, we might have had:
8137 template <class T> struct S {
8138 template <class U> friend void f(T, U);
8141 Then, in S<int>, template <class U> void f(int, U) is not an
8142 instantiation of anything. */
8143 if (new_friend == error_mark_node)
8144 return error_mark_node;
8146 DECL_USE_TEMPLATE (new_friend) = 0;
8147 if (TREE_CODE (decl) == TEMPLATE_DECL)
8149 DECL_USE_TEMPLATE (DECL_TEMPLATE_RESULT (new_friend)) = 0;
8150 DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (new_friend))
8151 = DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (decl));
8154 /* The mangled name for the NEW_FRIEND is incorrect. The function
8155 is not a template instantiation and should not be mangled like
8156 one. Therefore, we forget the mangling here; we'll recompute it
8157 later if we need it. */
8158 if (TREE_CODE (new_friend) != TEMPLATE_DECL)
8160 SET_DECL_RTL (new_friend, NULL);
8161 SET_DECL_ASSEMBLER_NAME (new_friend, NULL_TREE);
8164 if (DECL_NAMESPACE_SCOPE_P (new_friend))
8167 tree new_friend_template_info;
8168 tree new_friend_result_template_info;
8170 int new_friend_is_defn;
8172 /* We must save some information from NEW_FRIEND before calling
8173 duplicate decls since that function will free NEW_FRIEND if
8175 new_friend_template_info = DECL_TEMPLATE_INFO (new_friend);
8176 new_friend_is_defn =
8177 (DECL_INITIAL (DECL_TEMPLATE_RESULT
8178 (template_for_substitution (new_friend)))
8180 if (TREE_CODE (new_friend) == TEMPLATE_DECL)
8182 /* This declaration is a `primary' template. */
8183 DECL_PRIMARY_TEMPLATE (new_friend) = new_friend;
8185 new_friend_result_template_info
8186 = DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (new_friend));
8189 new_friend_result_template_info = NULL_TREE;
8191 /* Make the init_value nonzero so pushdecl knows this is a defn. */
8192 if (new_friend_is_defn)
8193 DECL_INITIAL (new_friend) = error_mark_node;
8195 /* Inside pushdecl_namespace_level, we will push into the
8196 current namespace. However, the friend function should go
8197 into the namespace of the template. */
8198 ns = decl_namespace_context (new_friend);
8199 push_nested_namespace (ns);
8200 old_decl = pushdecl_namespace_level (new_friend, /*is_friend=*/true);
8201 pop_nested_namespace (ns);
8203 if (old_decl == error_mark_node)
8204 return error_mark_node;
8206 if (old_decl != new_friend)
8208 /* This new friend declaration matched an existing
8209 declaration. For example, given:
8211 template <class T> void f(T);
8212 template <class U> class C {
8213 template <class T> friend void f(T) {}
8216 the friend declaration actually provides the definition
8217 of `f', once C has been instantiated for some type. So,
8218 old_decl will be the out-of-class template declaration,
8219 while new_friend is the in-class definition.
8221 But, if `f' was called before this point, the
8222 instantiation of `f' will have DECL_TI_ARGS corresponding
8223 to `T' but not to `U', references to which might appear
8224 in the definition of `f'. Previously, the most general
8225 template for an instantiation of `f' was the out-of-class
8226 version; now it is the in-class version. Therefore, we
8227 run through all specialization of `f', adding to their
8228 DECL_TI_ARGS appropriately. In particular, they need a
8229 new set of outer arguments, corresponding to the
8230 arguments for this class instantiation.
8232 The same situation can arise with something like this:
8235 template <class T> class C {
8239 when `C<int>' is instantiated. Now, `f(int)' is defined
8242 if (!new_friend_is_defn)
8243 /* On the other hand, if the in-class declaration does
8244 *not* provide a definition, then we don't want to alter
8245 existing definitions. We can just leave everything
8250 tree new_template = TI_TEMPLATE (new_friend_template_info);
8251 tree new_args = TI_ARGS (new_friend_template_info);
8253 /* Overwrite whatever template info was there before, if
8254 any, with the new template information pertaining to
8256 DECL_TEMPLATE_INFO (old_decl) = new_friend_template_info;
8258 if (TREE_CODE (old_decl) != TEMPLATE_DECL)
8260 /* We should have called reregister_specialization in
8262 gcc_assert (retrieve_specialization (new_template,
8266 /* Instantiate it if the global has already been used. */
8267 if (DECL_ODR_USED (old_decl))
8268 instantiate_decl (old_decl, /*defer_ok=*/true,
8269 /*expl_inst_class_mem_p=*/false);
8275 /* Indicate that the old function template is a partial
8277 DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (old_decl))
8278 = new_friend_result_template_info;
8280 gcc_assert (new_template
8281 == most_general_template (new_template));
8282 gcc_assert (new_template != old_decl);
8284 /* Reassign any specializations already in the hash table
8285 to the new more general template, and add the
8286 additional template args. */
8287 for (t = DECL_TEMPLATE_INSTANTIATIONS (old_decl);
8291 tree spec = TREE_VALUE (t);
8294 elt.tmpl = old_decl;
8295 elt.args = DECL_TI_ARGS (spec);
8296 elt.spec = NULL_TREE;
8298 htab_remove_elt (decl_specializations, &elt);
8301 = add_outermost_template_args (new_args,
8302 DECL_TI_ARGS (spec));
8304 register_specialization
8305 (spec, new_template, DECL_TI_ARGS (spec), true, 0);
8308 DECL_TEMPLATE_INSTANTIATIONS (old_decl) = NULL_TREE;
8312 /* The information from NEW_FRIEND has been merged into OLD_DECL
8313 by duplicate_decls. */
8314 new_friend = old_decl;
8319 tree context = DECL_CONTEXT (new_friend);
8323 template <class T> class C {
8324 template <class U> friend void C1<U>::f (); // case 1
8325 friend void C2<T>::f (); // case 2
8327 we only need to make sure CONTEXT is a complete type for
8328 case 2. To distinguish between the two cases, we note that
8329 CONTEXT of case 1 remains dependent type after tsubst while
8330 this isn't true for case 2. */
8331 ++processing_template_decl;
8332 dependent_p = dependent_type_p (context);
8333 --processing_template_decl;
8336 && !complete_type_or_else (context, NULL_TREE))
8337 return error_mark_node;
8339 if (COMPLETE_TYPE_P (context))
8341 /* Check to see that the declaration is really present, and,
8342 possibly obtain an improved declaration. */
8343 tree fn = check_classfn (context,
8344 new_friend, NULL_TREE);
8354 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
8355 template arguments, as for tsubst.
8357 Returns an appropriate tsubst'd friend type or error_mark_node on
8361 tsubst_friend_class (tree friend_tmpl, tree args)
8367 context = CP_DECL_CONTEXT (friend_tmpl);
8369 if (context != global_namespace)
8371 if (TREE_CODE (context) == NAMESPACE_DECL)
8372 push_nested_namespace (context);
8374 push_nested_class (tsubst (context, args, tf_none, NULL_TREE));
8377 /* Look for a class template declaration. We look for hidden names
8378 because two friend declarations of the same template are the
8379 same. For example, in:
8382 template <typename> friend class F;
8384 template <typename> struct B {
8385 template <typename> friend class F;
8388 both F templates are the same. */
8389 tmpl = lookup_name_real (DECL_NAME (friend_tmpl), 0, 0,
8390 /*block_p=*/true, 0,
8391 LOOKUP_COMPLAIN | LOOKUP_HIDDEN);
8393 /* But, if we don't find one, it might be because we're in a
8394 situation like this:
8402 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
8403 for `S<int>', not the TEMPLATE_DECL. */
8404 if (!tmpl || !DECL_CLASS_TEMPLATE_P (tmpl))
8406 tmpl = lookup_name_prefer_type (DECL_NAME (friend_tmpl), 1);
8407 tmpl = maybe_get_template_decl_from_type_decl (tmpl);
8410 if (tmpl && DECL_CLASS_TEMPLATE_P (tmpl))
8412 /* The friend template has already been declared. Just
8413 check to see that the declarations match, and install any new
8414 default parameters. We must tsubst the default parameters,
8415 of course. We only need the innermost template parameters
8416 because that is all that redeclare_class_template will look
8418 if (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (friend_tmpl))
8419 > TMPL_ARGS_DEPTH (args))
8422 location_t saved_input_location;
8423 parms = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_tmpl),
8424 args, tf_warning_or_error);
8426 saved_input_location = input_location;
8427 input_location = DECL_SOURCE_LOCATION (friend_tmpl);
8428 redeclare_class_template (TREE_TYPE (tmpl), parms);
8429 input_location = saved_input_location;
8433 friend_type = TREE_TYPE (tmpl);
8437 /* The friend template has not already been declared. In this
8438 case, the instantiation of the template class will cause the
8439 injection of this template into the global scope. */
8440 tmpl = tsubst (friend_tmpl, args, tf_warning_or_error, NULL_TREE);
8441 if (tmpl == error_mark_node)
8442 return error_mark_node;
8444 /* The new TMPL is not an instantiation of anything, so we
8445 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
8446 the new type because that is supposed to be the corresponding
8447 template decl, i.e., TMPL. */
8448 DECL_USE_TEMPLATE (tmpl) = 0;
8449 DECL_TEMPLATE_INFO (tmpl) = NULL_TREE;
8450 CLASSTYPE_USE_TEMPLATE (TREE_TYPE (tmpl)) = 0;
8451 CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl))
8452 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl)));
8454 /* Inject this template into the global scope. */
8455 friend_type = TREE_TYPE (pushdecl_top_level_maybe_friend (tmpl, true));
8458 if (context != global_namespace)
8460 if (TREE_CODE (context) == NAMESPACE_DECL)
8461 pop_nested_namespace (context);
8463 pop_nested_class ();
8469 /* Returns zero if TYPE cannot be completed later due to circularity.
8470 Otherwise returns one. */
8473 can_complete_type_without_circularity (tree type)
8475 if (type == NULL_TREE || type == error_mark_node)
8477 else if (COMPLETE_TYPE_P (type))
8479 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
8480 return can_complete_type_without_circularity (TREE_TYPE (type));
8481 else if (CLASS_TYPE_P (type)
8482 && TYPE_BEING_DEFINED (TYPE_MAIN_VARIANT (type)))
8488 /* Apply any attributes which had to be deferred until instantiation
8489 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
8490 ARGS, COMPLAIN, IN_DECL are as tsubst. */
8493 apply_late_template_attributes (tree *decl_p, tree attributes, int attr_flags,
8494 tree args, tsubst_flags_t complain, tree in_decl)
8496 tree last_dep = NULL_TREE;
8500 for (t = attributes; t; t = TREE_CHAIN (t))
8501 if (ATTR_IS_DEPENDENT (t))
8504 attributes = copy_list (attributes);
8508 if (DECL_P (*decl_p))
8510 if (TREE_TYPE (*decl_p) == error_mark_node)
8512 p = &DECL_ATTRIBUTES (*decl_p);
8515 p = &TYPE_ATTRIBUTES (*decl_p);
8519 tree late_attrs = NULL_TREE;
8520 tree *q = &late_attrs;
8522 for (*p = attributes; *p; )
8525 if (ATTR_IS_DEPENDENT (t))
8527 *p = TREE_CHAIN (t);
8528 TREE_CHAIN (t) = NULL_TREE;
8529 /* If the first attribute argument is an identifier, don't
8530 pass it through tsubst. Attributes like mode, format,
8531 cleanup and several target specific attributes expect it
8534 && TREE_CODE (TREE_VALUE (t)) == TREE_LIST
8535 && TREE_VALUE (TREE_VALUE (t))
8536 && (TREE_CODE (TREE_VALUE (TREE_VALUE (t)))
8537 == IDENTIFIER_NODE))
8540 = tsubst_expr (TREE_CHAIN (TREE_VALUE (t)), args, complain,
8542 /*integral_constant_expression_p=*/false);
8543 if (chain != TREE_CHAIN (TREE_VALUE (t)))
8545 = tree_cons (NULL_TREE, TREE_VALUE (TREE_VALUE (t)),
8550 = tsubst_expr (TREE_VALUE (t), args, complain, in_decl,
8551 /*integral_constant_expression_p=*/false);
8553 q = &TREE_CHAIN (t);
8556 p = &TREE_CHAIN (t);
8559 cplus_decl_attributes (decl_p, late_attrs, attr_flags);
8563 /* Perform (or defer) access check for typedefs that were referenced
8564 from within the template TMPL code.
8565 This is a subroutine of instantiate_template and instantiate_class_template.
8566 TMPL is the template to consider and TARGS is the list of arguments of
8570 perform_typedefs_access_check (tree tmpl, tree targs)
8572 location_t saved_location;
8574 qualified_typedef_usage_t *iter;
8577 || (!CLASS_TYPE_P (tmpl)
8578 && TREE_CODE (tmpl) != FUNCTION_DECL))
8581 saved_location = input_location;
8582 FOR_EACH_VEC_ELT (qualified_typedef_usage_t,
8583 get_types_needing_access_check (tmpl),
8586 tree type_decl = iter->typedef_decl;
8587 tree type_scope = iter->context;
8589 if (!type_decl || !type_scope || !CLASS_TYPE_P (type_scope))
8592 if (uses_template_parms (type_decl))
8593 type_decl = tsubst (type_decl, targs, tf_error, NULL_TREE);
8594 if (uses_template_parms (type_scope))
8595 type_scope = tsubst (type_scope, targs, tf_error, NULL_TREE);
8597 /* Make access check error messages point to the location
8598 of the use of the typedef. */
8599 input_location = iter->locus;
8600 perform_or_defer_access_check (TYPE_BINFO (type_scope),
8601 type_decl, type_decl);
8603 input_location = saved_location;
8607 instantiate_class_template_1 (tree type)
8609 tree templ, args, pattern, t, member;
8613 unsigned int saved_maximum_field_alignment;
8615 if (type == error_mark_node)
8616 return error_mark_node;
8618 if (COMPLETE_OR_OPEN_TYPE_P (type)
8619 || uses_template_parms (type))
8622 /* Figure out which template is being instantiated. */
8623 templ = most_general_template (CLASSTYPE_TI_TEMPLATE (type));
8624 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
8626 /* Determine what specialization of the original template to
8628 t = most_specialized_class (type, templ, tf_warning_or_error);
8629 if (t == error_mark_node)
8631 TYPE_BEING_DEFINED (type) = 1;
8632 return error_mark_node;
8636 /* This TYPE is actually an instantiation of a partial
8637 specialization. We replace the innermost set of ARGS with
8638 the arguments appropriate for substitution. For example,
8641 template <class T> struct S {};
8642 template <class T> struct S<T*> {};
8644 and supposing that we are instantiating S<int*>, ARGS will
8645 presently be {int*} -- but we need {int}. */
8646 pattern = TREE_TYPE (t);
8647 args = TREE_PURPOSE (t);
8651 pattern = TREE_TYPE (templ);
8652 args = CLASSTYPE_TI_ARGS (type);
8655 /* If the template we're instantiating is incomplete, then clearly
8656 there's nothing we can do. */
8657 if (!COMPLETE_TYPE_P (pattern))
8660 /* If we've recursively instantiated too many templates, stop. */
8661 if (! push_tinst_level (type))
8664 /* Now we're really doing the instantiation. Mark the type as in
8665 the process of being defined. */
8666 TYPE_BEING_DEFINED (type) = 1;
8668 /* We may be in the middle of deferred access check. Disable
8670 push_deferring_access_checks (dk_no_deferred);
8672 push_to_top_level ();
8673 /* Use #pragma pack from the template context. */
8674 saved_maximum_field_alignment = maximum_field_alignment;
8675 maximum_field_alignment = TYPE_PRECISION (pattern);
8677 SET_CLASSTYPE_INTERFACE_UNKNOWN (type);
8679 /* Set the input location to the most specialized template definition.
8680 This is needed if tsubsting causes an error. */
8681 typedecl = TYPE_MAIN_DECL (pattern);
8682 input_location = DECL_SOURCE_LOCATION (TYPE_NAME (type)) =
8683 DECL_SOURCE_LOCATION (typedecl);
8685 TYPE_PACKED (type) = TYPE_PACKED (pattern);
8686 TYPE_ALIGN (type) = TYPE_ALIGN (pattern);
8687 TYPE_USER_ALIGN (type) = TYPE_USER_ALIGN (pattern);
8688 TYPE_FOR_JAVA (type) = TYPE_FOR_JAVA (pattern); /* For libjava's JArray<T> */
8689 if (ANON_AGGR_TYPE_P (pattern))
8690 SET_ANON_AGGR_TYPE_P (type);
8691 if (CLASSTYPE_VISIBILITY_SPECIFIED (pattern))
8693 CLASSTYPE_VISIBILITY_SPECIFIED (type) = 1;
8694 CLASSTYPE_VISIBILITY (type) = CLASSTYPE_VISIBILITY (pattern);
8695 /* Adjust visibility for template arguments. */
8696 determine_visibility (TYPE_MAIN_DECL (type));
8698 CLASSTYPE_FINAL (type) = CLASSTYPE_FINAL (pattern);
8700 pbinfo = TYPE_BINFO (pattern);
8702 /* We should never instantiate a nested class before its enclosing
8703 class; we need to look up the nested class by name before we can
8704 instantiate it, and that lookup should instantiate the enclosing
8706 gcc_assert (!DECL_CLASS_SCOPE_P (TYPE_MAIN_DECL (pattern))
8707 || COMPLETE_OR_OPEN_TYPE_P (TYPE_CONTEXT (type)));
8709 base_list = NULL_TREE;
8710 if (BINFO_N_BASE_BINFOS (pbinfo))
8716 /* We must enter the scope containing the type, as that is where
8717 the accessibility of types named in dependent bases are
8719 pushed_scope = push_scope (CP_TYPE_CONTEXT (type));
8721 /* Substitute into each of the bases to determine the actual
8723 for (i = 0; BINFO_BASE_ITERATE (pbinfo, i, pbase_binfo); i++)
8726 tree access = BINFO_BASE_ACCESS (pbinfo, i);
8727 tree expanded_bases = NULL_TREE;
8730 if (PACK_EXPANSION_P (BINFO_TYPE (pbase_binfo)))
8733 tsubst_pack_expansion (BINFO_TYPE (pbase_binfo),
8734 args, tf_error, NULL_TREE);
8735 if (expanded_bases == error_mark_node)
8738 len = TREE_VEC_LENGTH (expanded_bases);
8741 for (idx = 0; idx < len; idx++)
8744 /* Extract the already-expanded base class. */
8745 base = TREE_VEC_ELT (expanded_bases, idx);
8747 /* Substitute to figure out the base class. */
8748 base = tsubst (BINFO_TYPE (pbase_binfo), args, tf_error,
8751 if (base == error_mark_node)
8754 base_list = tree_cons (access, base, base_list);
8755 if (BINFO_VIRTUAL_P (pbase_binfo))
8756 TREE_TYPE (base_list) = integer_type_node;
8760 /* The list is now in reverse order; correct that. */
8761 base_list = nreverse (base_list);
8764 pop_scope (pushed_scope);
8766 /* Now call xref_basetypes to set up all the base-class
8768 xref_basetypes (type, base_list);
8770 apply_late_template_attributes (&type, TYPE_ATTRIBUTES (pattern),
8771 (int) ATTR_FLAG_TYPE_IN_PLACE,
8772 args, tf_error, NULL_TREE);
8773 fixup_attribute_variants (type);
8775 /* Now that our base classes are set up, enter the scope of the
8776 class, so that name lookups into base classes, etc. will work
8777 correctly. This is precisely analogous to what we do in
8778 begin_class_definition when defining an ordinary non-template
8779 class, except we also need to push the enclosing classes. */
8780 push_nested_class (type);
8782 /* Now members are processed in the order of declaration. */
8783 for (member = CLASSTYPE_DECL_LIST (pattern);
8784 member; member = TREE_CHAIN (member))
8786 tree t = TREE_VALUE (member);
8788 if (TREE_PURPOSE (member))
8792 /* Build new CLASSTYPE_NESTED_UTDS. */
8795 bool class_template_p;
8797 class_template_p = (TREE_CODE (t) != ENUMERAL_TYPE
8798 && TYPE_LANG_SPECIFIC (t)
8799 && CLASSTYPE_IS_TEMPLATE (t));
8800 /* If the member is a class template, then -- even after
8801 substitution -- there may be dependent types in the
8802 template argument list for the class. We increment
8803 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
8804 that function will assume that no types are dependent
8805 when outside of a template. */
8806 if (class_template_p)
8807 ++processing_template_decl;
8808 newtag = tsubst (t, args, tf_error, NULL_TREE);
8809 if (class_template_p)
8810 --processing_template_decl;
8811 if (newtag == error_mark_node)
8814 if (TREE_CODE (newtag) != ENUMERAL_TYPE)
8816 tree name = TYPE_IDENTIFIER (t);
8818 if (class_template_p)
8819 /* Unfortunately, lookup_template_class sets
8820 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
8821 instantiation (i.e., for the type of a member
8822 template class nested within a template class.)
8823 This behavior is required for
8824 maybe_process_partial_specialization to work
8825 correctly, but is not accurate in this case;
8826 the TAG is not an instantiation of anything.
8827 (The corresponding TEMPLATE_DECL is an
8828 instantiation, but the TYPE is not.) */
8829 CLASSTYPE_USE_TEMPLATE (newtag) = 0;
8831 /* Now, we call pushtag to put this NEWTAG into the scope of
8832 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
8833 pushtag calling push_template_decl. We don't have to do
8834 this for enums because it will already have been done in
8837 SET_IDENTIFIER_TYPE_VALUE (name, newtag);
8838 pushtag (name, newtag, /*tag_scope=*/ts_current);
8841 else if (TREE_CODE (t) == FUNCTION_DECL
8842 || DECL_FUNCTION_TEMPLATE_P (t))
8844 /* Build new TYPE_METHODS. */
8847 if (TREE_CODE (t) == TEMPLATE_DECL)
8848 ++processing_template_decl;
8849 r = tsubst (t, args, tf_error, NULL_TREE);
8850 if (TREE_CODE (t) == TEMPLATE_DECL)
8851 --processing_template_decl;
8852 set_current_access_from_decl (r);
8853 finish_member_declaration (r);
8854 /* Instantiate members marked with attribute used. */
8855 if (r != error_mark_node && DECL_PRESERVE_P (r))
8860 /* Build new TYPE_FIELDS. */
8861 if (TREE_CODE (t) == STATIC_ASSERT)
8864 tsubst_expr (STATIC_ASSERT_CONDITION (t), args,
8865 tf_warning_or_error, NULL_TREE,
8866 /*integral_constant_expression_p=*/true);
8867 finish_static_assert (condition,
8868 STATIC_ASSERT_MESSAGE (t),
8869 STATIC_ASSERT_SOURCE_LOCATION (t),
8872 else if (TREE_CODE (t) != CONST_DECL)
8876 /* The file and line for this declaration, to
8877 assist in error message reporting. Since we
8878 called push_tinst_level above, we don't need to
8880 input_location = DECL_SOURCE_LOCATION (t);
8882 if (TREE_CODE (t) == TEMPLATE_DECL)
8883 ++processing_template_decl;
8884 r = tsubst (t, args, tf_warning_or_error, NULL_TREE);
8885 if (TREE_CODE (t) == TEMPLATE_DECL)
8886 --processing_template_decl;
8887 if (TREE_CODE (r) == VAR_DECL)
8891 [t]he initialization (and any associated
8892 side-effects) of a static data member does
8893 not occur unless the static data member is
8894 itself used in a way that requires the
8895 definition of the static data member to
8898 Therefore, we do not substitute into the
8899 initialized for the static data member here. */
8900 finish_static_data_member_decl
8903 /*init_const_expr_p=*/false,
8904 /*asmspec_tree=*/NULL_TREE,
8906 /* Instantiate members marked with attribute used. */
8907 if (r != error_mark_node && DECL_PRESERVE_P (r))
8910 else if (TREE_CODE (r) == FIELD_DECL)
8912 /* Determine whether R has a valid type and can be
8913 completed later. If R is invalid, then it is
8914 replaced by error_mark_node so that it will not be
8915 added to TYPE_FIELDS. */
8916 tree rtype = TREE_TYPE (r);
8917 if (can_complete_type_without_circularity (rtype))
8918 complete_type (rtype);
8920 if (!COMPLETE_TYPE_P (rtype))
8922 cxx_incomplete_type_error (r, rtype);
8923 r = error_mark_node;
8927 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
8928 such a thing will already have been added to the field
8929 list by tsubst_enum in finish_member_declaration in the
8930 CLASSTYPE_NESTED_UTDS case above. */
8931 if (!(TREE_CODE (r) == TYPE_DECL
8932 && TREE_CODE (TREE_TYPE (r)) == ENUMERAL_TYPE
8933 && DECL_ARTIFICIAL (r)))
8935 set_current_access_from_decl (r);
8936 finish_member_declaration (r);
8943 if (TYPE_P (t) || DECL_CLASS_TEMPLATE_P (t))
8945 /* Build new CLASSTYPE_FRIEND_CLASSES. */
8947 tree friend_type = t;
8948 bool adjust_processing_template_decl = false;
8950 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
8952 /* template <class T> friend class C; */
8953 friend_type = tsubst_friend_class (friend_type, args);
8954 adjust_processing_template_decl = true;
8956 else if (TREE_CODE (friend_type) == UNBOUND_CLASS_TEMPLATE)
8958 /* template <class T> friend class C::D; */
8959 friend_type = tsubst (friend_type, args,
8960 tf_warning_or_error, NULL_TREE);
8961 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
8962 friend_type = TREE_TYPE (friend_type);
8963 adjust_processing_template_decl = true;
8965 else if (TREE_CODE (friend_type) == TYPENAME_TYPE
8966 || TREE_CODE (friend_type) == TEMPLATE_TYPE_PARM)
8968 /* This could be either
8972 when dependent_type_p is false or
8974 template <class U> friend class T::C;
8977 friend_type = tsubst (friend_type, args,
8978 tf_warning_or_error, NULL_TREE);
8979 /* Bump processing_template_decl for correct
8980 dependent_type_p calculation. */
8981 ++processing_template_decl;
8982 if (dependent_type_p (friend_type))
8983 adjust_processing_template_decl = true;
8984 --processing_template_decl;
8986 else if (!CLASSTYPE_USE_TEMPLATE (friend_type)
8987 && hidden_name_p (TYPE_NAME (friend_type)))
8991 where C hasn't been declared yet. Let's lookup name
8992 from namespace scope directly, bypassing any name that
8993 come from dependent base class. */
8994 tree ns = decl_namespace_context (TYPE_MAIN_DECL (friend_type));
8996 /* The call to xref_tag_from_type does injection for friend
8998 push_nested_namespace (ns);
9000 xref_tag_from_type (friend_type, NULL_TREE,
9001 /*tag_scope=*/ts_current);
9002 pop_nested_namespace (ns);
9004 else if (uses_template_parms (friend_type))
9005 /* friend class C<T>; */
9006 friend_type = tsubst (friend_type, args,
9007 tf_warning_or_error, NULL_TREE);
9012 where C is already declared or
9014 friend class C<int>;
9016 We don't have to do anything in these cases. */
9018 if (adjust_processing_template_decl)
9019 /* Trick make_friend_class into realizing that the friend
9020 we're adding is a template, not an ordinary class. It's
9021 important that we use make_friend_class since it will
9022 perform some error-checking and output cross-reference
9024 ++processing_template_decl;
9026 if (friend_type != error_mark_node)
9027 make_friend_class (type, friend_type, /*complain=*/false);
9029 if (adjust_processing_template_decl)
9030 --processing_template_decl;
9034 /* Build new DECL_FRIENDLIST. */
9037 /* The file and line for this declaration, to
9038 assist in error message reporting. Since we
9039 called push_tinst_level above, we don't need to
9041 input_location = DECL_SOURCE_LOCATION (t);
9043 if (TREE_CODE (t) == TEMPLATE_DECL)
9045 ++processing_template_decl;
9046 push_deferring_access_checks (dk_no_check);
9049 r = tsubst_friend_function (t, args);
9050 add_friend (type, r, /*complain=*/false);
9051 if (TREE_CODE (t) == TEMPLATE_DECL)
9053 pop_deferring_access_checks ();
9054 --processing_template_decl;
9060 if (CLASSTYPE_LAMBDA_EXPR (type))
9062 tree lambda = CLASSTYPE_LAMBDA_EXPR (type);
9063 if (LAMBDA_EXPR_DEDUCE_RETURN_TYPE_P (lambda))
9065 apply_lambda_return_type (lambda, void_type_node);
9066 LAMBDA_EXPR_RETURN_TYPE (lambda) = NULL_TREE;
9068 instantiate_decl (lambda_function (type), false, false);
9069 maybe_add_lambda_conv_op (type);
9072 /* Set the file and line number information to whatever is given for
9073 the class itself. This puts error messages involving generated
9074 implicit functions at a predictable point, and the same point
9075 that would be used for non-template classes. */
9076 input_location = DECL_SOURCE_LOCATION (typedecl);
9078 unreverse_member_declarations (type);
9079 finish_struct_1 (type);
9080 TYPE_BEING_DEFINED (type) = 0;
9082 /* We don't instantiate default arguments for member functions. 14.7.1:
9084 The implicit instantiation of a class template specialization causes
9085 the implicit instantiation of the declarations, but not of the
9086 definitions or default arguments, of the class member functions,
9087 member classes, static data members and member templates.... */
9089 /* Some typedefs referenced from within the template code need to be access
9090 checked at template instantiation time, i.e now. These types were
9091 added to the template at parsing time. Let's get those and perform
9092 the access checks then. */
9093 perform_typedefs_access_check (pattern, args);
9094 perform_deferred_access_checks ();
9095 pop_nested_class ();
9096 maximum_field_alignment = saved_maximum_field_alignment;
9097 pop_from_top_level ();
9098 pop_deferring_access_checks ();
9101 /* The vtable for a template class can be emitted in any translation
9102 unit in which the class is instantiated. When there is no key
9103 method, however, finish_struct_1 will already have added TYPE to
9104 the keyed_classes list. */
9105 if (TYPE_CONTAINS_VPTR_P (type) && CLASSTYPE_KEY_METHOD (type))
9106 keyed_classes = tree_cons (NULL_TREE, type, keyed_classes);
9111 /* Wrapper for instantiate_class_template_1. */
9114 instantiate_class_template (tree type)
9117 timevar_push (TV_TEMPLATE_INST);
9118 ret = instantiate_class_template_1 (type);
9119 timevar_pop (TV_TEMPLATE_INST);
9124 tsubst_template_arg (tree t, tree args, tsubst_flags_t complain, tree in_decl)
9130 else if (TYPE_P (t))
9131 r = tsubst (t, args, complain, in_decl);
9134 if (!(complain & tf_warning))
9135 ++c_inhibit_evaluation_warnings;
9136 r = tsubst_expr (t, args, complain, in_decl,
9137 /*integral_constant_expression_p=*/true);
9138 if (!(complain & tf_warning))
9139 --c_inhibit_evaluation_warnings;
9140 /* Preserve the raw-reference nature of T. */
9141 if (TREE_TYPE (t) && TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE
9142 && REFERENCE_REF_P (r))
9143 r = TREE_OPERAND (r, 0);
9148 /* Given a function parameter pack TMPL_PARM and some function parameters
9149 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
9150 and set *SPEC_P to point at the next point in the list. */
9153 extract_fnparm_pack (tree tmpl_parm, tree *spec_p)
9155 /* Collect all of the extra "packed" parameters into an
9159 tree argpack = make_node (NONTYPE_ARGUMENT_PACK);
9160 tree argtypepack = cxx_make_type (TYPE_ARGUMENT_PACK);
9161 tree spec_parm = *spec_p;
9164 for (len = 0; spec_parm; ++len, spec_parm = TREE_CHAIN (spec_parm))
9166 && !function_parameter_expanded_from_pack_p (spec_parm, tmpl_parm))
9169 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
9170 parmvec = make_tree_vec (len);
9171 parmtypevec = make_tree_vec (len);
9172 spec_parm = *spec_p;
9173 for (i = 0; i < len; i++, spec_parm = DECL_CHAIN (spec_parm))
9175 TREE_VEC_ELT (parmvec, i) = spec_parm;
9176 TREE_VEC_ELT (parmtypevec, i) = TREE_TYPE (spec_parm);
9179 /* Build the argument packs. */
9180 SET_ARGUMENT_PACK_ARGS (argpack, parmvec);
9181 SET_ARGUMENT_PACK_ARGS (argtypepack, parmtypevec);
9182 TREE_TYPE (argpack) = argtypepack;
9183 *spec_p = spec_parm;
9188 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
9189 NONTYPE_ARGUMENT_PACK. */
9192 make_fnparm_pack (tree spec_parm)
9194 return extract_fnparm_pack (NULL_TREE, &spec_parm);
9197 /* Substitute ARGS into T, which is an pack expansion
9198 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
9199 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
9200 (if only a partial substitution could be performed) or
9201 ERROR_MARK_NODE if there was an error. */
9203 tsubst_pack_expansion (tree t, tree args, tsubst_flags_t complain,
9207 tree pack, packs = NULL_TREE;
9208 bool unsubstituted_packs = false;
9211 htab_t saved_local_specializations = NULL;
9213 gcc_assert (PACK_EXPANSION_P (t));
9214 pattern = PACK_EXPANSION_PATTERN (t);
9216 /* Determine the argument packs that will instantiate the parameter
9217 packs used in the expansion expression. While we're at it,
9218 compute the number of arguments to be expanded and make sure it
9220 for (pack = PACK_EXPANSION_PARAMETER_PACKS (t); pack;
9221 pack = TREE_CHAIN (pack))
9223 tree parm_pack = TREE_VALUE (pack);
9224 tree arg_pack = NULL_TREE;
9225 tree orig_arg = NULL_TREE;
9227 if (TREE_CODE (parm_pack) == BASES)
9229 if (BASES_DIRECT (parm_pack))
9230 return calculate_direct_bases (tsubst_expr (BASES_TYPE (parm_pack),
9231 args, complain, in_decl, false));
9233 return calculate_bases (tsubst_expr (BASES_TYPE (parm_pack),
9234 args, complain, in_decl, false));
9236 if (TREE_CODE (parm_pack) == PARM_DECL)
9238 if (!cp_unevaluated_operand)
9239 arg_pack = retrieve_local_specialization (parm_pack);
9242 /* We can't rely on local_specializations for a parameter
9243 name used later in a function declaration (such as in a
9244 late-specified return type). Even if it exists, it might
9245 have the wrong value for a recursive call. Just make a
9246 dummy decl, since it's only used for its type. */
9247 arg_pack = tsubst_decl (parm_pack, args, complain);
9248 if (arg_pack && FUNCTION_PARAMETER_PACK_P (arg_pack))
9249 /* Partial instantiation of the parm_pack, we can't build
9250 up an argument pack yet. */
9251 arg_pack = NULL_TREE;
9253 arg_pack = make_fnparm_pack (arg_pack);
9258 int level, idx, levels;
9259 template_parm_level_and_index (parm_pack, &level, &idx);
9261 levels = TMPL_ARGS_DEPTH (args);
9262 if (level <= levels)
9263 arg_pack = TMPL_ARG (args, level, idx);
9266 orig_arg = arg_pack;
9267 if (arg_pack && TREE_CODE (arg_pack) == ARGUMENT_PACK_SELECT)
9268 arg_pack = ARGUMENT_PACK_SELECT_FROM_PACK (arg_pack);
9270 if (arg_pack && !ARGUMENT_PACK_P (arg_pack))
9271 /* This can only happen if we forget to expand an argument
9272 pack somewhere else. Just return an error, silently. */
9274 result = make_tree_vec (1);
9275 TREE_VEC_ELT (result, 0) = error_mark_node;
9279 if (arg_from_parm_pack_p (arg_pack, parm_pack))
9280 /* The argument pack that the parameter maps to is just an
9281 expansion of the parameter itself, such as one would find
9282 in the implicit typedef of a class inside the class itself.
9283 Consider this parameter "unsubstituted", so that we will
9284 maintain the outer pack expansion. */
9285 arg_pack = NULL_TREE;
9290 TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack));
9292 /* Don't bother trying to do a partial substitution with
9293 incomplete packs; we'll try again after deduction. */
9294 if (ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
9299 else if (len != my_len)
9301 if (TREE_CODE (t) == TYPE_PACK_EXPANSION)
9302 error ("mismatched argument pack lengths while expanding "
9306 error ("mismatched argument pack lengths while expanding "
9309 return error_mark_node;
9312 /* Keep track of the parameter packs and their corresponding
9314 packs = tree_cons (parm_pack, arg_pack, packs);
9315 TREE_TYPE (packs) = orig_arg;
9319 /* We can't substitute for this parameter pack. */
9320 unsubstituted_packs = true;
9325 /* We cannot expand this expansion expression, because we don't have
9326 all of the argument packs we need. Substitute into the pattern
9327 and return a PACK_EXPANSION_*. The caller will need to deal with
9329 if (unsubstituted_packs)
9332 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
9333 new_pat = tsubst_expr (pattern, args, complain, in_decl,
9334 /*integral_constant_expression_p=*/false);
9336 new_pat = tsubst (pattern, args, complain, in_decl);
9337 return make_pack_expansion (new_pat);
9340 /* We could not find any argument packs that work. */
9342 return error_mark_node;
9344 if (cp_unevaluated_operand)
9346 /* We're in a late-specified return type, so create our own local
9347 specializations table; the current table is either NULL or (in the
9348 case of recursive unification) might have bindings that we don't
9349 want to use or alter. */
9350 saved_local_specializations = local_specializations;
9351 local_specializations = htab_create (37,
9352 hash_local_specialization,
9353 eq_local_specializations,
9357 /* For each argument in each argument pack, substitute into the
9359 result = make_tree_vec (len);
9360 for (i = 0; i < len; ++i)
9362 /* For parameter pack, change the substitution of the parameter
9363 pack to the ith argument in its argument pack, then expand
9365 for (pack = packs; pack; pack = TREE_CHAIN (pack))
9367 tree parm = TREE_PURPOSE (pack);
9370 /* Select the Ith argument from the pack. */
9371 if (TREE_CODE (parm) == PARM_DECL)
9375 arg = make_node (ARGUMENT_PACK_SELECT);
9376 ARGUMENT_PACK_SELECT_FROM_PACK (arg) = TREE_VALUE (pack);
9378 register_local_specialization (arg, parm);
9381 arg = retrieve_local_specialization (parm);
9386 template_parm_level_and_index (parm, &level, &idx);
9390 arg = make_node (ARGUMENT_PACK_SELECT);
9391 ARGUMENT_PACK_SELECT_FROM_PACK (arg) = TREE_VALUE (pack);
9392 /* Update the corresponding argument. */
9393 TMPL_ARG (args, level, idx) = arg;
9396 /* Re-use the ARGUMENT_PACK_SELECT. */
9397 arg = TMPL_ARG (args, level, idx);
9399 ARGUMENT_PACK_SELECT_INDEX (arg) = i;
9402 /* Substitute into the PATTERN with the altered arguments. */
9403 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
9404 TREE_VEC_ELT (result, i) =
9405 tsubst_expr (pattern, args, complain, in_decl,
9406 /*integral_constant_expression_p=*/false);
9408 TREE_VEC_ELT (result, i) = tsubst (pattern, args, complain, in_decl);
9410 if (TREE_VEC_ELT (result, i) == error_mark_node)
9412 result = error_mark_node;
9417 /* Update ARGS to restore the substitution from parameter packs to
9418 their argument packs. */
9419 for (pack = packs; pack; pack = TREE_CHAIN (pack))
9421 tree parm = TREE_PURPOSE (pack);
9423 if (TREE_CODE (parm) == PARM_DECL)
9424 register_local_specialization (TREE_TYPE (pack), parm);
9428 template_parm_level_and_index (parm, &level, &idx);
9430 /* Update the corresponding argument. */
9431 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
9432 TREE_VEC_ELT (TREE_VEC_ELT (args, level -1 ), idx) =
9435 TREE_VEC_ELT (args, idx) = TREE_TYPE (pack);
9439 if (saved_local_specializations)
9441 htab_delete (local_specializations);
9442 local_specializations = saved_local_specializations;
9448 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
9449 TMPL. We do this using DECL_PARM_INDEX, which should work even with
9450 parameter packs; all parms generated from a function parameter pack will
9451 have the same DECL_PARM_INDEX. */
9454 get_pattern_parm (tree parm, tree tmpl)
9456 tree pattern = DECL_TEMPLATE_RESULT (tmpl);
9459 if (DECL_ARTIFICIAL (parm))
9461 for (patparm = DECL_ARGUMENTS (pattern);
9462 patparm; patparm = DECL_CHAIN (patparm))
9463 if (DECL_ARTIFICIAL (patparm)
9464 && DECL_NAME (parm) == DECL_NAME (patparm))
9469 patparm = FUNCTION_FIRST_USER_PARM (DECL_TEMPLATE_RESULT (tmpl));
9470 patparm = chain_index (DECL_PARM_INDEX (parm)-1, patparm);
9471 gcc_assert (DECL_PARM_INDEX (patparm)
9472 == DECL_PARM_INDEX (parm));
9478 /* Substitute ARGS into the vector or list of template arguments T. */
9481 tsubst_template_args (tree t, tree args, tsubst_flags_t complain, tree in_decl)
9484 int len, need_new = 0, i, expanded_len_adjust = 0, out;
9487 if (t == error_mark_node)
9488 return error_mark_node;
9490 len = TREE_VEC_LENGTH (t);
9491 elts = XALLOCAVEC (tree, len);
9493 for (i = 0; i < len; i++)
9495 tree orig_arg = TREE_VEC_ELT (t, i);
9498 if (TREE_CODE (orig_arg) == TREE_VEC)
9499 new_arg = tsubst_template_args (orig_arg, args, complain, in_decl);
9500 else if (PACK_EXPANSION_P (orig_arg))
9502 /* Substitute into an expansion expression. */
9503 new_arg = tsubst_pack_expansion (orig_arg, args, complain, in_decl);
9505 if (TREE_CODE (new_arg) == TREE_VEC)
9506 /* Add to the expanded length adjustment the number of
9507 expanded arguments. We subtract one from this
9508 measurement, because the argument pack expression
9509 itself is already counted as 1 in
9510 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
9511 the argument pack is empty. */
9512 expanded_len_adjust += TREE_VEC_LENGTH (new_arg) - 1;
9514 else if (ARGUMENT_PACK_P (orig_arg))
9516 /* Substitute into each of the arguments. */
9517 new_arg = TYPE_P (orig_arg)
9518 ? cxx_make_type (TREE_CODE (orig_arg))
9519 : make_node (TREE_CODE (orig_arg));
9521 SET_ARGUMENT_PACK_ARGS (
9523 tsubst_template_args (ARGUMENT_PACK_ARGS (orig_arg),
9524 args, complain, in_decl));
9526 if (ARGUMENT_PACK_ARGS (new_arg) == error_mark_node)
9527 new_arg = error_mark_node;
9529 if (TREE_CODE (new_arg) == NONTYPE_ARGUMENT_PACK) {
9530 TREE_TYPE (new_arg) = tsubst (TREE_TYPE (orig_arg), args,
9532 TREE_CONSTANT (new_arg) = TREE_CONSTANT (orig_arg);
9534 if (TREE_TYPE (new_arg) == error_mark_node)
9535 new_arg = error_mark_node;
9539 new_arg = tsubst_template_arg (orig_arg, args, complain, in_decl);
9541 if (new_arg == error_mark_node)
9542 return error_mark_node;
9545 if (new_arg != orig_arg)
9552 /* Make space for the expanded arguments coming from template
9554 t = make_tree_vec (len + expanded_len_adjust);
9555 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
9556 arguments for a member template.
9557 In that case each TREE_VEC in ORIG_T represents a level of template
9558 arguments, and ORIG_T won't carry any non defaulted argument count.
9559 It will rather be the nested TREE_VECs that will carry one.
9560 In other words, ORIG_T carries a non defaulted argument count only
9561 if it doesn't contain any nested TREE_VEC. */
9562 if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t))
9564 int count = GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t);
9565 count += expanded_len_adjust;
9566 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (t, count);
9568 for (i = 0, out = 0; i < len; i++)
9570 if ((PACK_EXPANSION_P (TREE_VEC_ELT (orig_t, i))
9571 || ARGUMENT_PACK_P (TREE_VEC_ELT (orig_t, i)))
9572 && TREE_CODE (elts[i]) == TREE_VEC)
9576 /* Now expand the template argument pack "in place". */
9577 for (idx = 0; idx < TREE_VEC_LENGTH (elts[i]); idx++, out++)
9578 TREE_VEC_ELT (t, out) = TREE_VEC_ELT (elts[i], idx);
9582 TREE_VEC_ELT (t, out) = elts[i];
9590 /* Return the result of substituting ARGS into the template parameters
9591 given by PARMS. If there are m levels of ARGS and m + n levels of
9592 PARMS, then the result will contain n levels of PARMS. For
9593 example, if PARMS is `template <class T> template <class U>
9594 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
9595 result will be `template <int*, double, class V>'. */
9598 tsubst_template_parms (tree parms, tree args, tsubst_flags_t complain)
9603 /* When substituting into a template, we must set
9604 PROCESSING_TEMPLATE_DECL as the template parameters may be
9605 dependent if they are based on one-another, and the dependency
9606 predicates are short-circuit outside of templates. */
9607 ++processing_template_decl;
9609 for (new_parms = &r;
9610 TMPL_PARMS_DEPTH (parms) > TMPL_ARGS_DEPTH (args);
9611 new_parms = &(TREE_CHAIN (*new_parms)),
9612 parms = TREE_CHAIN (parms))
9615 make_tree_vec (TREE_VEC_LENGTH (TREE_VALUE (parms)));
9618 for (i = 0; i < TREE_VEC_LENGTH (new_vec); ++i)
9622 if (parms == error_mark_node)
9625 tuple = TREE_VEC_ELT (TREE_VALUE (parms), i);
9627 if (tuple == error_mark_node)
9630 TREE_VEC_ELT (new_vec, i) =
9631 tsubst_template_parm (tuple, args, complain);
9635 tree_cons (size_int (TMPL_PARMS_DEPTH (parms)
9636 - TMPL_ARGS_DEPTH (args)),
9637 new_vec, NULL_TREE);
9640 --processing_template_decl;
9645 /* Return the result of substituting ARGS into one template parameter
9646 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
9647 parameter and which TREE_PURPOSE is the default argument of the
9648 template parameter. */
9651 tsubst_template_parm (tree t, tree args, tsubst_flags_t complain)
9653 tree default_value, parm_decl;
9655 if (args == NULL_TREE
9657 || t == error_mark_node)
9660 gcc_assert (TREE_CODE (t) == TREE_LIST);
9662 default_value = TREE_PURPOSE (t);
9663 parm_decl = TREE_VALUE (t);
9665 parm_decl = tsubst (parm_decl, args, complain, NULL_TREE);
9666 if (TREE_CODE (parm_decl) == PARM_DECL
9667 && invalid_nontype_parm_type_p (TREE_TYPE (parm_decl), complain))
9668 parm_decl = error_mark_node;
9669 default_value = tsubst_template_arg (default_value, args,
9670 complain, NULL_TREE);
9672 return build_tree_list (default_value, parm_decl);
9675 /* Substitute the ARGS into the indicated aggregate (or enumeration)
9676 type T. If T is not an aggregate or enumeration type, it is
9677 handled as if by tsubst. IN_DECL is as for tsubst. If
9678 ENTERING_SCOPE is nonzero, T is the context for a template which
9679 we are presently tsubst'ing. Return the substituted value. */
9682 tsubst_aggr_type (tree t,
9684 tsubst_flags_t complain,
9691 switch (TREE_CODE (t))
9694 if (TYPE_PTRMEMFUNC_P (t))
9695 return tsubst (TYPE_PTRMEMFUNC_FN_TYPE (t), args, complain, in_decl);
9697 /* Else fall through. */
9700 if (TYPE_TEMPLATE_INFO (t) && uses_template_parms (t))
9705 int saved_unevaluated_operand;
9706 int saved_inhibit_evaluation_warnings;
9708 /* In "sizeof(X<I>)" we need to evaluate "I". */
9709 saved_unevaluated_operand = cp_unevaluated_operand;
9710 cp_unevaluated_operand = 0;
9711 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
9712 c_inhibit_evaluation_warnings = 0;
9714 /* First, determine the context for the type we are looking
9716 context = TYPE_CONTEXT (t);
9717 if (context && TYPE_P (context))
9719 context = tsubst_aggr_type (context, args, complain,
9720 in_decl, /*entering_scope=*/1);
9721 /* If context is a nested class inside a class template,
9722 it may still need to be instantiated (c++/33959). */
9723 context = complete_type (context);
9726 /* Then, figure out what arguments are appropriate for the
9727 type we are trying to find. For example, given:
9729 template <class T> struct S;
9730 template <class T, class U> void f(T, U) { S<U> su; }
9732 and supposing that we are instantiating f<int, double>,
9733 then our ARGS will be {int, double}, but, when looking up
9734 S we only want {double}. */
9735 argvec = tsubst_template_args (TYPE_TI_ARGS (t), args,
9737 if (argvec == error_mark_node)
9738 r = error_mark_node;
9741 r = lookup_template_class (t, argvec, in_decl, context,
9742 entering_scope, complain);
9743 r = cp_build_qualified_type_real (r, cp_type_quals (t), complain);
9746 cp_unevaluated_operand = saved_unevaluated_operand;
9747 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
9752 /* This is not a template type, so there's nothing to do. */
9756 return tsubst (t, args, complain, in_decl);
9760 /* Substitute into the default argument ARG (a default argument for
9761 FN), which has the indicated TYPE. */
9764 tsubst_default_argument (tree fn, tree type, tree arg)
9766 tree saved_class_ptr = NULL_TREE;
9767 tree saved_class_ref = NULL_TREE;
9769 /* This can happen in invalid code. */
9770 if (TREE_CODE (arg) == DEFAULT_ARG)
9773 /* This default argument came from a template. Instantiate the
9774 default argument here, not in tsubst. In the case of
9783 we must be careful to do name lookup in the scope of S<T>,
9784 rather than in the current class. */
9785 push_access_scope (fn);
9786 /* The "this" pointer is not valid in a default argument. */
9789 saved_class_ptr = current_class_ptr;
9790 cp_function_chain->x_current_class_ptr = NULL_TREE;
9791 saved_class_ref = current_class_ref;
9792 cp_function_chain->x_current_class_ref = NULL_TREE;
9795 push_deferring_access_checks(dk_no_deferred);
9796 /* The default argument expression may cause implicitly defined
9797 member functions to be synthesized, which will result in garbage
9798 collection. We must treat this situation as if we were within
9799 the body of function so as to avoid collecting live data on the
9802 arg = tsubst_expr (arg, DECL_TI_ARGS (fn),
9803 tf_warning_or_error, NULL_TREE,
9804 /*integral_constant_expression_p=*/false);
9806 pop_deferring_access_checks();
9808 /* Restore the "this" pointer. */
9811 cp_function_chain->x_current_class_ptr = saved_class_ptr;
9812 cp_function_chain->x_current_class_ref = saved_class_ref;
9815 /* Make sure the default argument is reasonable. */
9816 arg = check_default_argument (type, arg);
9818 pop_access_scope (fn);
9823 /* Substitute into all the default arguments for FN. */
9826 tsubst_default_arguments (tree fn)
9831 tmpl_args = DECL_TI_ARGS (fn);
9833 /* If this function is not yet instantiated, we certainly don't need
9834 its default arguments. */
9835 if (uses_template_parms (tmpl_args))
9837 /* Don't do this again for clones. */
9838 if (DECL_CLONED_FUNCTION_P (fn))
9841 for (arg = TYPE_ARG_TYPES (TREE_TYPE (fn));
9843 arg = TREE_CHAIN (arg))
9844 if (TREE_PURPOSE (arg))
9845 TREE_PURPOSE (arg) = tsubst_default_argument (fn,
9847 TREE_PURPOSE (arg));
9850 /* Substitute the ARGS into the T, which is a _DECL. Return the
9851 result of the substitution. Issue error and warning messages under
9852 control of COMPLAIN. */
9855 tsubst_decl (tree t, tree args, tsubst_flags_t complain)
9857 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
9858 location_t saved_loc;
9863 /* Set the filename and linenumber to improve error-reporting. */
9864 saved_loc = input_location;
9865 input_location = DECL_SOURCE_LOCATION (t);
9867 switch (TREE_CODE (t))
9871 /* We can get here when processing a member function template,
9872 member class template, or template template parameter. */
9873 tree decl = DECL_TEMPLATE_RESULT (t);
9878 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
9880 /* Template template parameter is treated here. */
9881 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9882 if (new_type == error_mark_node)
9883 RETURN (error_mark_node);
9886 DECL_CHAIN (r) = NULL_TREE;
9887 TREE_TYPE (r) = new_type;
9888 DECL_TEMPLATE_RESULT (r)
9889 = build_decl (DECL_SOURCE_LOCATION (decl),
9890 TYPE_DECL, DECL_NAME (decl), new_type);
9891 DECL_TEMPLATE_PARMS (r)
9892 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
9894 TYPE_NAME (new_type) = r;
9898 /* We might already have an instance of this template.
9899 The ARGS are for the surrounding class type, so the
9900 full args contain the tsubst'd args for the context,
9901 plus the innermost args from the template decl. */
9902 tmpl_args = DECL_CLASS_TEMPLATE_P (t)
9903 ? CLASSTYPE_TI_ARGS (TREE_TYPE (t))
9904 : DECL_TI_ARGS (DECL_TEMPLATE_RESULT (t));
9905 /* Because this is a template, the arguments will still be
9906 dependent, even after substitution. If
9907 PROCESSING_TEMPLATE_DECL is not set, the dependency
9908 predicates will short-circuit. */
9909 ++processing_template_decl;
9910 full_args = tsubst_template_args (tmpl_args, args,
9912 --processing_template_decl;
9913 if (full_args == error_mark_node)
9914 RETURN (error_mark_node);
9916 /* If this is a default template template argument,
9917 tsubst might not have changed anything. */
9918 if (full_args == tmpl_args)
9921 hash = hash_tmpl_and_args (t, full_args);
9922 spec = retrieve_specialization (t, full_args, hash);
9923 if (spec != NULL_TREE)
9929 /* Make a new template decl. It will be similar to the
9930 original, but will record the current template arguments.
9931 We also create a new function declaration, which is just
9932 like the old one, but points to this new template, rather
9933 than the old one. */
9935 gcc_assert (DECL_LANG_SPECIFIC (r) != 0);
9936 DECL_CHAIN (r) = NULL_TREE;
9938 DECL_TEMPLATE_INFO (r) = build_template_info (t, args);
9940 if (TREE_CODE (decl) == TYPE_DECL
9941 && !TYPE_DECL_ALIAS_P (decl))
9944 ++processing_template_decl;
9945 new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9946 --processing_template_decl;
9947 if (new_type == error_mark_node)
9948 RETURN (error_mark_node);
9950 TREE_TYPE (r) = new_type;
9951 CLASSTYPE_TI_TEMPLATE (new_type) = r;
9952 DECL_TEMPLATE_RESULT (r) = TYPE_MAIN_DECL (new_type);
9953 DECL_TI_ARGS (r) = CLASSTYPE_TI_ARGS (new_type);
9954 DECL_CONTEXT (r) = TYPE_CONTEXT (new_type);
9959 ++processing_template_decl;
9960 new_decl = tsubst (decl, args, complain, in_decl);
9961 --processing_template_decl;
9962 if (new_decl == error_mark_node)
9963 RETURN (error_mark_node);
9965 DECL_TEMPLATE_RESULT (r) = new_decl;
9966 DECL_TI_TEMPLATE (new_decl) = r;
9967 TREE_TYPE (r) = TREE_TYPE (new_decl);
9968 DECL_TI_ARGS (r) = DECL_TI_ARGS (new_decl);
9969 DECL_CONTEXT (r) = DECL_CONTEXT (new_decl);
9972 SET_DECL_IMPLICIT_INSTANTIATION (r);
9973 DECL_TEMPLATE_INSTANTIATIONS (r) = NULL_TREE;
9974 DECL_TEMPLATE_SPECIALIZATIONS (r) = NULL_TREE;
9976 /* The template parameters for this new template are all the
9977 template parameters for the old template, except the
9978 outermost level of parameters. */
9979 DECL_TEMPLATE_PARMS (r)
9980 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
9983 if (PRIMARY_TEMPLATE_P (t))
9984 DECL_PRIMARY_TEMPLATE (r) = r;
9986 if (TREE_CODE (decl) != TYPE_DECL)
9987 /* Record this non-type partial instantiation. */
9988 register_specialization (r, t,
9989 DECL_TI_ARGS (DECL_TEMPLATE_RESULT (r)),
9997 tree argvec = NULL_TREE;
10005 /* Nobody should be tsubst'ing into non-template functions. */
10006 gcc_assert (DECL_TEMPLATE_INFO (t) != NULL_TREE);
10008 if (TREE_CODE (DECL_TI_TEMPLATE (t)) == TEMPLATE_DECL)
10013 /* If T is not dependent, just return it. We have to
10014 increment PROCESSING_TEMPLATE_DECL because
10015 value_dependent_expression_p assumes that nothing is
10016 dependent when PROCESSING_TEMPLATE_DECL is zero. */
10017 ++processing_template_decl;
10018 dependent_p = value_dependent_expression_p (t);
10019 --processing_template_decl;
10023 /* Calculate the most general template of which R is a
10024 specialization, and the complete set of arguments used to
10026 gen_tmpl = most_general_template (DECL_TI_TEMPLATE (t));
10027 argvec = tsubst_template_args (DECL_TI_ARGS
10028 (DECL_TEMPLATE_RESULT
10029 (DECL_TI_TEMPLATE (t))),
10030 args, complain, in_decl);
10031 if (argvec == error_mark_node)
10032 RETURN (error_mark_node);
10034 /* Check to see if we already have this specialization. */
10035 hash = hash_tmpl_and_args (gen_tmpl, argvec);
10036 spec = retrieve_specialization (gen_tmpl, argvec, hash);
10044 /* We can see more levels of arguments than parameters if
10045 there was a specialization of a member template, like
10048 template <class T> struct S { template <class U> void f(); }
10049 template <> template <class U> void S<int>::f(U);
10051 Here, we'll be substituting into the specialization,
10052 because that's where we can find the code we actually
10053 want to generate, but we'll have enough arguments for
10054 the most general template.
10056 We also deal with the peculiar case:
10058 template <class T> struct S {
10059 template <class U> friend void f();
10061 template <class U> void f() {}
10063 template void f<double>();
10065 Here, the ARGS for the instantiation of will be {int,
10066 double}. But, we only need as many ARGS as there are
10067 levels of template parameters in CODE_PATTERN. We are
10068 careful not to get fooled into reducing the ARGS in
10071 template <class T> struct S { template <class U> void f(U); }
10072 template <class T> template <> void S<T>::f(int) {}
10074 which we can spot because the pattern will be a
10075 specialization in this case. */
10076 args_depth = TMPL_ARGS_DEPTH (args);
10078 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (t)));
10079 if (args_depth > parms_depth
10080 && !DECL_TEMPLATE_SPECIALIZATION (t))
10081 args = get_innermost_template_args (args, parms_depth);
10085 /* This special case arises when we have something like this:
10087 template <class T> struct S {
10088 friend void f<int>(int, double);
10091 Here, the DECL_TI_TEMPLATE for the friend declaration
10092 will be an IDENTIFIER_NODE. We are being called from
10093 tsubst_friend_function, and we want only to create a
10094 new decl (R) with appropriate types so that we can call
10095 determine_specialization. */
10096 gen_tmpl = NULL_TREE;
10099 if (DECL_CLASS_SCOPE_P (t))
10101 if (DECL_NAME (t) == constructor_name (DECL_CONTEXT (t)))
10105 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args,
10106 complain, t, /*entering_scope=*/1);
10111 ctx = DECL_CONTEXT (t);
10113 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10114 if (type == error_mark_node)
10115 RETURN (error_mark_node);
10117 /* We do NOT check for matching decls pushed separately at this
10118 point, as they may not represent instantiations of this
10119 template, and in any case are considered separate under the
10122 DECL_USE_TEMPLATE (r) = 0;
10123 TREE_TYPE (r) = type;
10124 /* Clear out the mangled name and RTL for the instantiation. */
10125 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
10126 SET_DECL_RTL (r, NULL);
10127 /* Leave DECL_INITIAL set on deleted instantiations. */
10128 if (!DECL_DELETED_FN (r))
10129 DECL_INITIAL (r) = NULL_TREE;
10130 DECL_CONTEXT (r) = ctx;
10132 if (member && DECL_CONV_FN_P (r))
10133 /* Type-conversion operator. Reconstruct the name, in
10134 case it's the name of one of the template's parameters. */
10135 DECL_NAME (r) = mangle_conv_op_name_for_type (TREE_TYPE (type));
10137 DECL_ARGUMENTS (r) = tsubst (DECL_ARGUMENTS (t), args,
10139 DECL_RESULT (r) = NULL_TREE;
10141 TREE_STATIC (r) = 0;
10142 TREE_PUBLIC (r) = TREE_PUBLIC (t);
10143 DECL_EXTERNAL (r) = 1;
10144 /* If this is an instantiation of a function with internal
10145 linkage, we already know what object file linkage will be
10146 assigned to the instantiation. */
10147 DECL_INTERFACE_KNOWN (r) = !TREE_PUBLIC (r);
10148 DECL_DEFER_OUTPUT (r) = 0;
10149 DECL_CHAIN (r) = NULL_TREE;
10150 DECL_PENDING_INLINE_INFO (r) = 0;
10151 DECL_PENDING_INLINE_P (r) = 0;
10152 DECL_SAVED_TREE (r) = NULL_TREE;
10153 DECL_STRUCT_FUNCTION (r) = NULL;
10155 /* We'll re-clone as appropriate in instantiate_template. */
10156 DECL_CLONED_FUNCTION (r) = NULL_TREE;
10158 /* If we aren't complaining now, return on error before we register
10159 the specialization so that we'll complain eventually. */
10160 if ((complain & tf_error) == 0
10161 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
10162 && !grok_op_properties (r, /*complain=*/false))
10163 RETURN (error_mark_node);
10165 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
10166 this in the special friend case mentioned above where
10167 GEN_TMPL is NULL. */
10170 DECL_TEMPLATE_INFO (r)
10171 = build_template_info (gen_tmpl, argvec);
10172 SET_DECL_IMPLICIT_INSTANTIATION (r);
10173 register_specialization (r, gen_tmpl, argvec, false, hash);
10175 /* We're not supposed to instantiate default arguments
10176 until they are called, for a template. But, for a
10179 template <class T> void f ()
10180 { extern void g(int i = T()); }
10182 we should do the substitution when the template is
10183 instantiated. We handle the member function case in
10184 instantiate_class_template since the default arguments
10185 might refer to other members of the class. */
10187 && !PRIMARY_TEMPLATE_P (gen_tmpl)
10188 && !uses_template_parms (argvec))
10189 tsubst_default_arguments (r);
10192 DECL_TEMPLATE_INFO (r) = NULL_TREE;
10194 /* Copy the list of befriending classes. */
10195 for (friends = &DECL_BEFRIENDING_CLASSES (r);
10197 friends = &TREE_CHAIN (*friends))
10199 *friends = copy_node (*friends);
10200 TREE_VALUE (*friends) = tsubst (TREE_VALUE (*friends),
10205 if (DECL_CONSTRUCTOR_P (r) || DECL_DESTRUCTOR_P (r))
10207 maybe_retrofit_in_chrg (r);
10208 if (DECL_CONSTRUCTOR_P (r))
10209 grok_ctor_properties (ctx, r);
10210 /* If this is an instantiation of a member template, clone it.
10211 If it isn't, that'll be handled by
10212 clone_constructors_and_destructors. */
10213 if (PRIMARY_TEMPLATE_P (gen_tmpl))
10214 clone_function_decl (r, /*update_method_vec_p=*/0);
10216 else if ((complain & tf_error) != 0
10217 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
10218 && !grok_op_properties (r, /*complain=*/true))
10219 RETURN (error_mark_node);
10221 if (DECL_FRIEND_P (t) && DECL_FRIEND_CONTEXT (t))
10222 SET_DECL_FRIEND_CONTEXT (r,
10223 tsubst (DECL_FRIEND_CONTEXT (t),
10224 args, complain, in_decl));
10226 /* Possibly limit visibility based on template args. */
10227 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
10228 if (DECL_VISIBILITY_SPECIFIED (t))
10230 DECL_VISIBILITY_SPECIFIED (r) = 0;
10231 DECL_ATTRIBUTES (r)
10232 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
10234 determine_visibility (r);
10235 if (DECL_DEFAULTED_OUTSIDE_CLASS_P (r)
10236 && !processing_template_decl)
10237 defaulted_late_check (r);
10239 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
10240 args, complain, in_decl);
10246 tree type = NULL_TREE;
10248 tree expanded_types = NULL_TREE;
10249 tree prev_r = NULL_TREE;
10250 tree first_r = NULL_TREE;
10252 if (FUNCTION_PARAMETER_PACK_P (t))
10254 /* If there is a local specialization that isn't a
10255 parameter pack, it means that we're doing a "simple"
10256 substitution from inside tsubst_pack_expansion. Just
10257 return the local specialization (which will be a single
10259 tree spec = retrieve_local_specialization (t);
10261 && TREE_CODE (spec) == PARM_DECL
10262 && TREE_CODE (TREE_TYPE (spec)) != TYPE_PACK_EXPANSION)
10265 /* Expand the TYPE_PACK_EXPANSION that provides the types for
10266 the parameters in this function parameter pack. */
10267 expanded_types = tsubst_pack_expansion (TREE_TYPE (t), args,
10268 complain, in_decl);
10269 if (TREE_CODE (expanded_types) == TREE_VEC)
10271 len = TREE_VEC_LENGTH (expanded_types);
10273 /* Zero-length parameter packs are boring. Just substitute
10276 RETURN (tsubst (TREE_CHAIN (t), args, complain,
10281 /* All we did was update the type. Make a note of that. */
10282 type = expanded_types;
10283 expanded_types = NULL_TREE;
10287 /* Loop through all of the parameter's we'll build. When T is
10288 a function parameter pack, LEN is the number of expanded
10289 types in EXPANDED_TYPES; otherwise, LEN is 1. */
10291 for (i = 0; i < len; ++i)
10295 if (DECL_TEMPLATE_PARM_P (t))
10296 SET_DECL_TEMPLATE_PARM_P (r);
10298 if (expanded_types)
10299 /* We're on the Ith parameter of the function parameter
10302 /* An argument of a function parameter pack is not a parameter
10304 FUNCTION_PARAMETER_PACK_P (r) = false;
10306 /* Get the Ith type. */
10307 type = TREE_VEC_ELT (expanded_types, i);
10310 /* Rename the parameter to include the index. */
10312 make_ith_pack_parameter_name (DECL_NAME (r), i);
10315 /* We're dealing with a normal parameter. */
10316 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10318 type = type_decays_to (type);
10319 TREE_TYPE (r) = type;
10320 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
10322 if (DECL_INITIAL (r))
10324 if (TREE_CODE (DECL_INITIAL (r)) != TEMPLATE_PARM_INDEX)
10325 DECL_INITIAL (r) = TREE_TYPE (r);
10327 DECL_INITIAL (r) = tsubst (DECL_INITIAL (r), args,
10328 complain, in_decl);
10331 DECL_CONTEXT (r) = NULL_TREE;
10333 if (!DECL_TEMPLATE_PARM_P (r))
10334 DECL_ARG_TYPE (r) = type_passed_as (type);
10336 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
10337 args, complain, in_decl);
10339 /* Keep track of the first new parameter we
10340 generate. That's what will be returned to the
10345 /* Build a proper chain of parameters when substituting
10346 into a function parameter pack. */
10348 DECL_CHAIN (prev_r) = r;
10351 if (DECL_CHAIN (t))
10352 DECL_CHAIN (r) = tsubst (DECL_CHAIN (t), args,
10353 complain, DECL_CHAIN (t));
10355 /* FIRST_R contains the start of the chain we've built. */
10365 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10366 if (type == error_mark_node)
10367 RETURN (error_mark_node);
10368 TREE_TYPE (r) = type;
10369 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
10371 if (DECL_C_BIT_FIELD (r))
10372 /* For bit-fields, DECL_INITIAL gives the number of bits. For
10373 non-bit-fields DECL_INITIAL is a non-static data member
10374 initializer, which gets deferred instantiation. */
10376 = tsubst_expr (DECL_INITIAL (t), args,
10378 /*integral_constant_expression_p=*/true);
10379 else if (DECL_INITIAL (t))
10381 /* Set up DECL_TEMPLATE_INFO so that we can get at the
10382 NSDMI in perform_member_init. Still set DECL_INITIAL
10383 so that we know there is one. */
10384 DECL_INITIAL (r) = void_zero_node;
10385 gcc_assert (DECL_LANG_SPECIFIC (r) == NULL);
10386 retrofit_lang_decl (r);
10387 DECL_TEMPLATE_INFO (r) = build_template_info (t, args);
10389 /* We don't have to set DECL_CONTEXT here; it is set by
10390 finish_member_declaration. */
10391 DECL_CHAIN (r) = NULL_TREE;
10392 if (VOID_TYPE_P (type))
10393 error ("instantiation of %q+D as type %qT", r, type);
10395 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
10396 args, complain, in_decl);
10401 /* We reach here only for member using decls. */
10402 if (DECL_DEPENDENT_P (t))
10404 r = do_class_using_decl
10405 (tsubst_copy (USING_DECL_SCOPE (t), args, complain, in_decl),
10406 tsubst_copy (DECL_NAME (t), args, complain, in_decl));
10408 r = error_mark_node;
10411 TREE_PROTECTED (r) = TREE_PROTECTED (t);
10412 TREE_PRIVATE (r) = TREE_PRIVATE (t);
10418 DECL_CHAIN (r) = NULL_TREE;
10425 tree argvec = NULL_TREE;
10426 tree gen_tmpl = NULL_TREE;
10428 tree tmpl = NULL_TREE;
10430 tree type = NULL_TREE;
10433 if (TREE_CODE (t) == TYPE_DECL
10434 && t == TYPE_MAIN_DECL (TREE_TYPE (t)))
10436 /* If this is the canonical decl, we don't have to
10437 mess with instantiations, and often we can't (for
10438 typename, template type parms and such). Note that
10439 TYPE_NAME is not correct for the above test if
10440 we've copied the type for a typedef. */
10441 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10442 if (type == error_mark_node)
10443 RETURN (error_mark_node);
10444 r = TYPE_NAME (type);
10448 /* Check to see if we already have the specialization we
10451 if (DECL_CLASS_SCOPE_P (t) || DECL_NAMESPACE_SCOPE_P (t))
10453 /* T is a static data member or namespace-scope entity.
10454 We have to substitute into namespace-scope variables
10455 (even though such entities are never templates) because
10458 template <class T> void f() { extern T t; }
10460 where the entity referenced is not known until
10461 instantiation time. */
10463 ctx = DECL_CONTEXT (t);
10464 if (DECL_CLASS_SCOPE_P (t))
10466 ctx = tsubst_aggr_type (ctx, args,
10468 in_decl, /*entering_scope=*/1);
10469 /* If CTX is unchanged, then T is in fact the
10470 specialization we want. That situation occurs when
10471 referencing a static data member within in its own
10472 class. We can use pointer equality, rather than
10473 same_type_p, because DECL_CONTEXT is always
10475 if (ctx == DECL_CONTEXT (t)
10476 && (TREE_CODE (t) != TYPE_DECL
10477 /* ... unless T is a member template; in which
10478 case our caller can be willing to create a
10479 specialization of that template represented
10481 || !(DECL_TI_TEMPLATE (t)
10482 && DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (t)))))
10488 tmpl = DECL_TI_TEMPLATE (t);
10489 gen_tmpl = most_general_template (tmpl);
10490 argvec = tsubst (DECL_TI_ARGS (t), args, complain, in_decl);
10491 hash = hash_tmpl_and_args (gen_tmpl, argvec);
10492 spec = retrieve_specialization (gen_tmpl, argvec, hash);
10497 /* A local variable. */
10499 /* Subsequent calls to pushdecl will fill this in. */
10501 spec = retrieve_local_specialization (t);
10503 /* If we already have the specialization we need, there is
10504 nothing more to do. */
10511 /* Create a new node for the specialization we need. */
10513 if (type == NULL_TREE)
10515 if (is_typedef_decl (t))
10516 type = DECL_ORIGINAL_TYPE (t);
10518 type = TREE_TYPE (t);
10519 if (TREE_CODE (t) == VAR_DECL && VAR_HAD_UNKNOWN_BOUND (t))
10520 type = strip_array_domain (type);
10521 type = tsubst (type, args, complain, in_decl);
10523 if (TREE_CODE (r) == VAR_DECL)
10525 /* Even if the original location is out of scope, the
10526 newly substituted one is not. */
10527 DECL_DEAD_FOR_LOCAL (r) = 0;
10528 DECL_INITIALIZED_P (r) = 0;
10529 DECL_TEMPLATE_INSTANTIATED (r) = 0;
10530 if (type == error_mark_node)
10531 RETURN (error_mark_node);
10532 if (TREE_CODE (type) == FUNCTION_TYPE)
10534 /* It may seem that this case cannot occur, since:
10539 declares a function, not a variable. However:
10542 template <typename T> void g() { T t; }
10543 template void g<f>();
10545 is an attempt to declare a variable with function
10547 error ("variable %qD has function type",
10548 /* R is not yet sufficiently initialized, so we
10549 just use its name. */
10551 RETURN (error_mark_node);
10553 type = complete_type (type);
10554 /* Wait until cp_finish_decl to set this again, to handle
10555 circular dependency (template/instantiate6.C). */
10556 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r) = 0;
10557 type = check_var_type (DECL_NAME (r), type);
10559 if (DECL_HAS_VALUE_EXPR_P (t))
10561 tree ve = DECL_VALUE_EXPR (t);
10562 ve = tsubst_expr (ve, args, complain, in_decl,
10563 /*constant_expression_p=*/false);
10564 if (REFERENCE_REF_P (ve))
10566 gcc_assert (TREE_CODE (type) == REFERENCE_TYPE);
10567 ve = TREE_OPERAND (ve, 0);
10569 SET_DECL_VALUE_EXPR (r, ve);
10572 else if (DECL_SELF_REFERENCE_P (t))
10573 SET_DECL_SELF_REFERENCE_P (r);
10574 TREE_TYPE (r) = type;
10575 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
10576 DECL_CONTEXT (r) = ctx;
10577 /* Clear out the mangled name and RTL for the instantiation. */
10578 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
10579 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
10580 SET_DECL_RTL (r, NULL);
10581 /* The initializer must not be expanded until it is required;
10582 see [temp.inst]. */
10583 DECL_INITIAL (r) = NULL_TREE;
10584 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
10585 SET_DECL_RTL (r, NULL);
10586 DECL_SIZE (r) = DECL_SIZE_UNIT (r) = 0;
10587 if (TREE_CODE (r) == VAR_DECL)
10589 /* Possibly limit visibility based on template args. */
10590 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
10591 if (DECL_VISIBILITY_SPECIFIED (t))
10593 DECL_VISIBILITY_SPECIFIED (r) = 0;
10594 DECL_ATTRIBUTES (r)
10595 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
10597 determine_visibility (r);
10602 /* A static data member declaration is always marked
10603 external when it is declared in-class, even if an
10604 initializer is present. We mimic the non-template
10605 processing here. */
10606 DECL_EXTERNAL (r) = 1;
10608 register_specialization (r, gen_tmpl, argvec, false, hash);
10609 DECL_TEMPLATE_INFO (r) = build_template_info (tmpl, argvec);
10610 SET_DECL_IMPLICIT_INSTANTIATION (r);
10612 else if (cp_unevaluated_operand)
10614 /* We're substituting this var in a decltype outside of its
10615 scope, such as for a lambda return type. Don't add it to
10616 local_specializations, do perform auto deduction. */
10617 tree auto_node = type_uses_auto (type);
10621 = tsubst_expr (DECL_INITIAL (t), args, complain, in_decl,
10622 /*constant_expression_p=*/false);
10623 init = resolve_nondeduced_context (init);
10624 TREE_TYPE (r) = type
10625 = do_auto_deduction (type, init, auto_node);
10629 register_local_specialization (r, t);
10631 DECL_CHAIN (r) = NULL_TREE;
10633 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r),
10635 args, complain, in_decl);
10637 /* Preserve a typedef that names a type. */
10638 if (is_typedef_decl (r))
10640 DECL_ORIGINAL_TYPE (r) = NULL_TREE;
10641 set_underlying_type (r);
10644 layout_decl (r, 0);
10649 gcc_unreachable ();
10654 /* Restore the file and line information. */
10655 input_location = saved_loc;
10660 /* Substitute into the ARG_TYPES of a function type. */
10663 tsubst_arg_types (tree arg_types,
10665 tsubst_flags_t complain,
10668 tree remaining_arg_types;
10669 tree type = NULL_TREE;
10671 tree expanded_args = NULL_TREE;
10674 if (!arg_types || arg_types == void_list_node)
10677 remaining_arg_types = tsubst_arg_types (TREE_CHAIN (arg_types),
10678 args, complain, in_decl);
10679 if (remaining_arg_types == error_mark_node)
10680 return error_mark_node;
10682 if (PACK_EXPANSION_P (TREE_VALUE (arg_types)))
10684 /* For a pack expansion, perform substitution on the
10685 entire expression. Later on, we'll handle the arguments
10687 expanded_args = tsubst_pack_expansion (TREE_VALUE (arg_types),
10688 args, complain, in_decl);
10690 if (TREE_CODE (expanded_args) == TREE_VEC)
10691 /* So that we'll spin through the parameters, one by one. */
10692 i = TREE_VEC_LENGTH (expanded_args);
10695 /* We only partially substituted into the parameter
10696 pack. Our type is TYPE_PACK_EXPANSION. */
10697 type = expanded_args;
10698 expanded_args = NULL_TREE;
10706 type = TREE_VEC_ELT (expanded_args, i);
10708 type = tsubst (TREE_VALUE (arg_types), args, complain, in_decl);
10710 if (type == error_mark_node)
10711 return error_mark_node;
10712 if (VOID_TYPE_P (type))
10714 if (complain & tf_error)
10716 error ("invalid parameter type %qT", type);
10718 error ("in declaration %q+D", in_decl);
10720 return error_mark_node;
10723 /* Do array-to-pointer, function-to-pointer conversion, and ignore
10724 top-level qualifiers as required. */
10725 type = cv_unqualified (type_decays_to (type));
10727 /* We do not substitute into default arguments here. The standard
10728 mandates that they be instantiated only when needed, which is
10729 done in build_over_call. */
10730 default_arg = TREE_PURPOSE (arg_types);
10732 if (default_arg && TREE_CODE (default_arg) == DEFAULT_ARG)
10734 /* We've instantiated a template before its default arguments
10735 have been parsed. This can happen for a nested template
10736 class, and is not an error unless we require the default
10737 argument in a call of this function. */
10738 remaining_arg_types =
10739 tree_cons (default_arg, type, remaining_arg_types);
10740 VEC_safe_push (tree, gc, DEFARG_INSTANTIATIONS (default_arg),
10741 remaining_arg_types);
10744 remaining_arg_types =
10745 hash_tree_cons (default_arg, type, remaining_arg_types);
10748 return remaining_arg_types;
10751 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
10752 *not* handle the exception-specification for FNTYPE, because the
10753 initial substitution of explicitly provided template parameters
10754 during argument deduction forbids substitution into the
10755 exception-specification:
10759 All references in the function type of the function template to the
10760 corresponding template parameters are replaced by the specified tem-
10761 plate argument values. If a substitution in a template parameter or
10762 in the function type of the function template results in an invalid
10763 type, type deduction fails. [Note: The equivalent substitution in
10764 exception specifications is done only when the function is instanti-
10765 ated, at which point a program is ill-formed if the substitution
10766 results in an invalid type.] */
10769 tsubst_function_type (tree t,
10771 tsubst_flags_t complain,
10778 /* The TYPE_CONTEXT is not used for function/method types. */
10779 gcc_assert (TYPE_CONTEXT (t) == NULL_TREE);
10781 /* Substitute the return type. */
10782 return_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10783 if (return_type == error_mark_node)
10784 return error_mark_node;
10785 /* The standard does not presently indicate that creation of a
10786 function type with an invalid return type is a deduction failure.
10787 However, that is clearly analogous to creating an array of "void"
10788 or a reference to a reference. This is core issue #486. */
10789 if (TREE_CODE (return_type) == ARRAY_TYPE
10790 || TREE_CODE (return_type) == FUNCTION_TYPE)
10792 if (complain & tf_error)
10794 if (TREE_CODE (return_type) == ARRAY_TYPE)
10795 error ("function returning an array");
10797 error ("function returning a function");
10799 return error_mark_node;
10802 /* Substitute the argument types. */
10803 arg_types = tsubst_arg_types (TYPE_ARG_TYPES (t), args,
10804 complain, in_decl);
10805 if (arg_types == error_mark_node)
10806 return error_mark_node;
10808 /* Construct a new type node and return it. */
10809 if (TREE_CODE (t) == FUNCTION_TYPE)
10811 fntype = build_function_type (return_type, arg_types);
10812 fntype = apply_memfn_quals (fntype, type_memfn_quals (t));
10816 tree r = TREE_TYPE (TREE_VALUE (arg_types));
10817 if (! MAYBE_CLASS_TYPE_P (r))
10821 Type deduction may fail for any of the following
10824 -- Attempting to create "pointer to member of T" when T
10825 is not a class type. */
10826 if (complain & tf_error)
10827 error ("creating pointer to member function of non-class type %qT",
10829 return error_mark_node;
10832 fntype = build_method_type_directly (r, return_type,
10833 TREE_CHAIN (arg_types));
10835 fntype = cp_build_type_attribute_variant (fntype, TYPE_ATTRIBUTES (t));
10840 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
10841 ARGS into that specification, and return the substituted
10842 specification. If there is no specification, return NULL_TREE. */
10845 tsubst_exception_specification (tree fntype,
10847 tsubst_flags_t complain,
10854 specs = TYPE_RAISES_EXCEPTIONS (fntype);
10855 new_specs = NULL_TREE;
10856 if (specs && TREE_PURPOSE (specs))
10858 /* A noexcept-specifier. */
10859 tree expr = TREE_PURPOSE (specs);
10860 if (expr == boolean_true_node || expr == boolean_false_node)
10864 /* Defer instantiation of noexcept-specifiers to avoid
10865 excessive instantiations (c++/49107). */
10866 new_specs = make_node (DEFERRED_NOEXCEPT);
10867 if (DEFERRED_NOEXCEPT_SPEC_P (specs))
10869 /* We already partially instantiated this member template,
10870 so combine the new args with the old. */
10871 DEFERRED_NOEXCEPT_PATTERN (new_specs)
10872 = DEFERRED_NOEXCEPT_PATTERN (expr);
10873 DEFERRED_NOEXCEPT_ARGS (new_specs)
10874 = add_to_template_args (DEFERRED_NOEXCEPT_ARGS (expr), args);
10878 DEFERRED_NOEXCEPT_PATTERN (new_specs) = expr;
10879 DEFERRED_NOEXCEPT_ARGS (new_specs) = args;
10883 new_specs = tsubst_copy_and_build
10884 (expr, args, complain, in_decl, /*function_p=*/false,
10885 /*integral_constant_expression_p=*/true);
10886 new_specs = build_noexcept_spec (new_specs, complain);
10890 if (! TREE_VALUE (specs))
10897 tree expanded_specs = NULL_TREE;
10899 if (PACK_EXPANSION_P (TREE_VALUE (specs)))
10901 /* Expand the pack expansion type. */
10902 expanded_specs = tsubst_pack_expansion (TREE_VALUE (specs),
10906 if (expanded_specs == error_mark_node)
10907 return error_mark_node;
10908 else if (TREE_CODE (expanded_specs) == TREE_VEC)
10909 len = TREE_VEC_LENGTH (expanded_specs);
10912 /* We're substituting into a member template, so
10913 we got a TYPE_PACK_EXPANSION back. Add that
10914 expansion and move on. */
10915 gcc_assert (TREE_CODE (expanded_specs)
10916 == TYPE_PACK_EXPANSION);
10917 new_specs = add_exception_specifier (new_specs,
10920 specs = TREE_CHAIN (specs);
10925 for (i = 0; i < len; ++i)
10927 if (expanded_specs)
10928 spec = TREE_VEC_ELT (expanded_specs, i);
10930 spec = tsubst (TREE_VALUE (specs), args, complain, in_decl);
10931 if (spec == error_mark_node)
10933 new_specs = add_exception_specifier (new_specs, spec,
10937 specs = TREE_CHAIN (specs);
10943 /* Take the tree structure T and replace template parameters used
10944 therein with the argument vector ARGS. IN_DECL is an associated
10945 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
10946 Issue error and warning messages under control of COMPLAIN. Note
10947 that we must be relatively non-tolerant of extensions here, in
10948 order to preserve conformance; if we allow substitutions that
10949 should not be allowed, we may allow argument deductions that should
10950 not succeed, and therefore report ambiguous overload situations
10951 where there are none. In theory, we could allow the substitution,
10952 but indicate that it should have failed, and allow our caller to
10953 make sure that the right thing happens, but we don't try to do this
10956 This function is used for dealing with types, decls and the like;
10957 for expressions, use tsubst_expr or tsubst_copy. */
10960 tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl)
10962 enum tree_code code;
10963 tree type, r = NULL_TREE;
10965 if (t == NULL_TREE || t == error_mark_node
10966 || t == integer_type_node
10967 || t == void_type_node
10968 || t == char_type_node
10969 || t == unknown_type_node
10970 || TREE_CODE (t) == NAMESPACE_DECL
10971 || TREE_CODE (t) == TRANSLATION_UNIT_DECL)
10975 return tsubst_decl (t, args, complain);
10977 if (args == NULL_TREE)
10980 code = TREE_CODE (t);
10982 if (code == IDENTIFIER_NODE)
10983 type = IDENTIFIER_TYPE_VALUE (t);
10985 type = TREE_TYPE (t);
10987 gcc_assert (type != unknown_type_node);
10989 /* Reuse typedefs. We need to do this to handle dependent attributes,
10990 such as attribute aligned. */
10992 && typedef_variant_p (t))
10994 tree decl = TYPE_NAME (t);
10996 if (TYPE_DECL_ALIAS_P (decl)
10997 && DECL_LANG_SPECIFIC (decl)
10998 && DECL_TEMPLATE_INFO (decl)
10999 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (decl)))
11001 /* DECL represents an alias template and we want to
11002 instantiate it. Let's substitute our arguments for the
11003 template parameters into the declaration and get the
11005 r = tsubst (decl, args, complain, decl);
11007 else if (DECL_CLASS_SCOPE_P (decl)
11008 && CLASSTYPE_TEMPLATE_INFO (DECL_CONTEXT (decl))
11009 && uses_template_parms (DECL_CONTEXT (decl)))
11011 tree tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
11012 tree gen_args = tsubst (DECL_TI_ARGS (decl), args, complain, in_decl);
11013 r = retrieve_specialization (tmpl, gen_args, 0);
11015 else if (DECL_FUNCTION_SCOPE_P (decl)
11016 && DECL_TEMPLATE_INFO (DECL_CONTEXT (decl))
11017 && uses_template_parms (DECL_TI_ARGS (DECL_CONTEXT (decl))))
11018 r = retrieve_local_specialization (decl);
11020 /* The typedef is from a non-template context. */
11026 r = cp_build_qualified_type_real
11027 (r, cp_type_quals (t) | cp_type_quals (r),
11028 complain | tf_ignore_bad_quals);
11031 /* Else we must be instantiating the typedef, so fall through. */
11035 && code != TYPENAME_TYPE
11036 && code != TEMPLATE_TYPE_PARM
11037 && code != IDENTIFIER_NODE
11038 && code != FUNCTION_TYPE
11039 && code != METHOD_TYPE)
11040 type = tsubst (type, args, complain, in_decl);
11041 if (type == error_mark_node)
11042 return error_mark_node;
11048 case ENUMERAL_TYPE:
11049 return tsubst_aggr_type (t, args, complain, in_decl,
11050 /*entering_scope=*/0);
11053 case IDENTIFIER_NODE:
11064 if (t == integer_type_node)
11067 if (TREE_CODE (TYPE_MIN_VALUE (t)) == INTEGER_CST
11068 && TREE_CODE (TYPE_MAX_VALUE (t)) == INTEGER_CST)
11072 tree max, omax = TREE_OPERAND (TYPE_MAX_VALUE (t), 0);
11074 max = tsubst_expr (omax, args, complain, in_decl,
11075 /*integral_constant_expression_p=*/false);
11077 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
11079 if (TREE_CODE (max) == NOP_EXPR
11080 && TREE_SIDE_EFFECTS (omax)
11081 && !TREE_TYPE (max))
11082 TREE_TYPE (max) = TREE_TYPE (TREE_OPERAND (max, 0));
11084 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
11085 with TREE_SIDE_EFFECTS that indicates this is not an integral
11086 constant expression. */
11087 if (processing_template_decl
11088 && TREE_SIDE_EFFECTS (omax) && TREE_CODE (omax) == NOP_EXPR)
11090 gcc_assert (TREE_CODE (max) == NOP_EXPR);
11091 TREE_SIDE_EFFECTS (max) = 1;
11094 return compute_array_index_type (NULL_TREE, max, complain);
11097 case TEMPLATE_TYPE_PARM:
11098 case TEMPLATE_TEMPLATE_PARM:
11099 case BOUND_TEMPLATE_TEMPLATE_PARM:
11100 case TEMPLATE_PARM_INDEX:
11105 tree arg = NULL_TREE;
11109 gcc_assert (TREE_VEC_LENGTH (args) > 0);
11110 template_parm_level_and_index (t, &level, &idx);
11112 levels = TMPL_ARGS_DEPTH (args);
11113 if (level <= levels)
11115 arg = TMPL_ARG (args, level, idx);
11117 if (arg && TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
11118 /* See through ARGUMENT_PACK_SELECT arguments. */
11119 arg = ARGUMENT_PACK_SELECT_ARG (arg);
11122 if (arg == error_mark_node)
11123 return error_mark_node;
11124 else if (arg != NULL_TREE)
11126 if (ARGUMENT_PACK_P (arg))
11127 /* If ARG is an argument pack, we don't actually want to
11128 perform a substitution here, because substitutions
11129 for argument packs are only done
11130 element-by-element. We can get to this point when
11131 substituting the type of a non-type template
11132 parameter pack, when that type actually contains
11133 template parameter packs from an outer template, e.g.,
11135 template<typename... Types> struct A {
11136 template<Types... Values> struct B { };
11140 if (code == TEMPLATE_TYPE_PARM)
11143 gcc_assert (TYPE_P (arg));
11145 quals = cp_type_quals (arg) | cp_type_quals (t);
11147 return cp_build_qualified_type_real
11148 (arg, quals, complain | tf_ignore_bad_quals);
11150 else if (code == BOUND_TEMPLATE_TEMPLATE_PARM)
11152 /* We are processing a type constructed from a
11153 template template parameter. */
11154 tree argvec = tsubst (TYPE_TI_ARGS (t),
11155 args, complain, in_decl);
11156 if (argvec == error_mark_node)
11157 return error_mark_node;
11159 gcc_assert (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
11160 || TREE_CODE (arg) == TEMPLATE_DECL
11161 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE);
11163 if (TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE)
11164 /* Consider this code:
11166 template <template <class> class Template>
11168 template <class Arg> using Bind = Template<Arg>;
11171 template <template <class> class Template, class Arg>
11172 using Instantiate = Template<Arg>; //#0
11174 template <template <class> class Template,
11177 Instantiate<Internal<Template>::template Bind,
11180 When #1 is parsed, the
11181 BOUND_TEMPLATE_TEMPLATE_PARM representing the
11182 parameter `Template' in #0 matches the
11183 UNBOUND_CLASS_TEMPLATE representing the argument
11184 `Internal<Template>::template Bind'; We then want
11185 to assemble the type `Bind<Argument>' that can't
11186 be fully created right now, because
11187 `Internal<Template>' not being complete, the Bind
11188 template cannot be looked up in that context. So
11189 we need to "store" `Bind<Argument>' for later
11190 when the context of Bind becomes complete. Let's
11191 store that in a TYPENAME_TYPE. */
11192 return make_typename_type (TYPE_CONTEXT (arg),
11193 build_nt (TEMPLATE_ID_EXPR,
11194 TYPE_IDENTIFIER (arg),
11199 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
11200 are resolving nested-types in the signature of a
11201 member function templates. Otherwise ARG is a
11202 TEMPLATE_DECL and is the real template to be
11204 if (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
11205 arg = TYPE_NAME (arg);
11207 r = lookup_template_class (arg,
11209 DECL_CONTEXT (arg),
11210 /*entering_scope=*/0,
11212 return cp_build_qualified_type_real
11213 (r, cp_type_quals (t), complain);
11216 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
11217 return convert_from_reference (unshare_expr (arg));
11221 /* This can happen during the attempted tsubst'ing in
11222 unify. This means that we don't yet have any information
11223 about the template parameter in question. */
11226 /* If we get here, we must have been looking at a parm for a
11227 more deeply nested template. Make a new version of this
11228 template parameter, but with a lower level. */
11231 case TEMPLATE_TYPE_PARM:
11232 case TEMPLATE_TEMPLATE_PARM:
11233 case BOUND_TEMPLATE_TEMPLATE_PARM:
11234 if (cp_type_quals (t))
11236 r = tsubst (TYPE_MAIN_VARIANT (t), args, complain, in_decl);
11237 r = cp_build_qualified_type_real
11238 (r, cp_type_quals (t),
11239 complain | (code == TEMPLATE_TYPE_PARM
11240 ? tf_ignore_bad_quals : 0));
11245 TEMPLATE_TYPE_PARM_INDEX (r)
11246 = reduce_template_parm_level (TEMPLATE_TYPE_PARM_INDEX (t),
11247 r, levels, args, complain);
11248 TYPE_STUB_DECL (r) = TYPE_NAME (r) = TEMPLATE_TYPE_DECL (r);
11249 TYPE_MAIN_VARIANT (r) = r;
11250 TYPE_POINTER_TO (r) = NULL_TREE;
11251 TYPE_REFERENCE_TO (r) = NULL_TREE;
11253 if (TREE_CODE (r) == TEMPLATE_TEMPLATE_PARM)
11254 /* We have reduced the level of the template
11255 template parameter, but not the levels of its
11256 template parameters, so canonical_type_parameter
11257 will not be able to find the canonical template
11258 template parameter for this level. Thus, we
11259 require structural equality checking to compare
11260 TEMPLATE_TEMPLATE_PARMs. */
11261 SET_TYPE_STRUCTURAL_EQUALITY (r);
11262 else if (TYPE_STRUCTURAL_EQUALITY_P (t))
11263 SET_TYPE_STRUCTURAL_EQUALITY (r);
11265 TYPE_CANONICAL (r) = canonical_type_parameter (r);
11267 if (code == BOUND_TEMPLATE_TEMPLATE_PARM)
11269 tree argvec = tsubst (TYPE_TI_ARGS (t), args,
11270 complain, in_decl);
11271 if (argvec == error_mark_node)
11272 return error_mark_node;
11274 TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (r)
11275 = build_template_info (TYPE_TI_TEMPLATE (t), argvec);
11280 case TEMPLATE_PARM_INDEX:
11281 r = reduce_template_parm_level (t, type, levels, args, complain);
11285 gcc_unreachable ();
11293 tree purpose, value, chain;
11295 if (t == void_list_node)
11298 purpose = TREE_PURPOSE (t);
11301 purpose = tsubst (purpose, args, complain, in_decl);
11302 if (purpose == error_mark_node)
11303 return error_mark_node;
11305 value = TREE_VALUE (t);
11308 value = tsubst (value, args, complain, in_decl);
11309 if (value == error_mark_node)
11310 return error_mark_node;
11312 chain = TREE_CHAIN (t);
11313 if (chain && chain != void_type_node)
11315 chain = tsubst (chain, args, complain, in_decl);
11316 if (chain == error_mark_node)
11317 return error_mark_node;
11319 if (purpose == TREE_PURPOSE (t)
11320 && value == TREE_VALUE (t)
11321 && chain == TREE_CHAIN (t))
11323 return hash_tree_cons (purpose, value, chain);
11327 /* We should never be tsubsting a binfo. */
11328 gcc_unreachable ();
11331 /* A vector of template arguments. */
11332 gcc_assert (!type);
11333 return tsubst_template_args (t, args, complain, in_decl);
11336 case REFERENCE_TYPE:
11338 if (type == TREE_TYPE (t) && TREE_CODE (type) != METHOD_TYPE)
11343 Type deduction may fail for any of the following
11346 -- Attempting to create a pointer to reference type.
11347 -- Attempting to create a reference to a reference type or
11348 a reference to void.
11350 Core issue 106 says that creating a reference to a reference
11351 during instantiation is no longer a cause for failure. We
11352 only enforce this check in strict C++98 mode. */
11353 if ((TREE_CODE (type) == REFERENCE_TYPE
11354 && (((cxx_dialect == cxx98) && flag_iso) || code != REFERENCE_TYPE))
11355 || (code == REFERENCE_TYPE && TREE_CODE (type) == VOID_TYPE))
11357 static location_t last_loc;
11359 /* We keep track of the last time we issued this error
11360 message to avoid spewing a ton of messages during a
11361 single bad template instantiation. */
11362 if (complain & tf_error
11363 && last_loc != input_location)
11365 if (TREE_CODE (type) == VOID_TYPE)
11366 error ("forming reference to void");
11367 else if (code == POINTER_TYPE)
11368 error ("forming pointer to reference type %qT", type);
11370 error ("forming reference to reference type %qT", type);
11371 last_loc = input_location;
11374 return error_mark_node;
11376 else if (code == POINTER_TYPE)
11378 r = build_pointer_type (type);
11379 if (TREE_CODE (type) == METHOD_TYPE)
11380 r = build_ptrmemfunc_type (r);
11382 else if (TREE_CODE (type) == REFERENCE_TYPE)
11383 /* In C++0x, during template argument substitution, when there is an
11384 attempt to create a reference to a reference type, reference
11385 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
11387 "If a template-argument for a template-parameter T names a type
11388 that is a reference to a type A, an attempt to create the type
11389 'lvalue reference to cv T' creates the type 'lvalue reference to
11390 A,' while an attempt to create the type type rvalue reference to
11391 cv T' creates the type T"
11393 r = cp_build_reference_type
11395 TYPE_REF_IS_RVALUE (t) && TYPE_REF_IS_RVALUE (type));
11397 r = cp_build_reference_type (type, TYPE_REF_IS_RVALUE (t));
11398 r = cp_build_qualified_type_real (r, cp_type_quals (t), complain);
11400 if (r != error_mark_node)
11401 /* Will this ever be needed for TYPE_..._TO values? */
11408 r = tsubst (TYPE_OFFSET_BASETYPE (t), args, complain, in_decl);
11409 if (r == error_mark_node || !MAYBE_CLASS_TYPE_P (r))
11413 Type deduction may fail for any of the following
11416 -- Attempting to create "pointer to member of T" when T
11417 is not a class type. */
11418 if (complain & tf_error)
11419 error ("creating pointer to member of non-class type %qT", r);
11420 return error_mark_node;
11422 if (TREE_CODE (type) == REFERENCE_TYPE)
11424 if (complain & tf_error)
11425 error ("creating pointer to member reference type %qT", type);
11426 return error_mark_node;
11428 if (TREE_CODE (type) == VOID_TYPE)
11430 if (complain & tf_error)
11431 error ("creating pointer to member of type void");
11432 return error_mark_node;
11434 gcc_assert (TREE_CODE (type) != METHOD_TYPE);
11435 if (TREE_CODE (type) == FUNCTION_TYPE)
11437 /* The type of the implicit object parameter gets its
11438 cv-qualifiers from the FUNCTION_TYPE. */
11440 tree method_type = build_memfn_type (type, r, type_memfn_quals (type));
11441 memptr = build_ptrmemfunc_type (build_pointer_type (method_type));
11442 return cp_build_qualified_type_real (memptr, cp_type_quals (t),
11446 return cp_build_qualified_type_real (build_ptrmem_type (r, type),
11450 case FUNCTION_TYPE:
11455 fntype = tsubst_function_type (t, args, complain, in_decl);
11456 if (fntype == error_mark_node)
11457 return error_mark_node;
11459 /* Substitute the exception specification. */
11460 specs = tsubst_exception_specification (t, args, complain,
11461 in_decl, /*defer_ok*/true);
11462 if (specs == error_mark_node)
11463 return error_mark_node;
11465 fntype = build_exception_variant (fntype, specs);
11470 tree domain = tsubst (TYPE_DOMAIN (t), args, complain, in_decl);
11471 if (domain == error_mark_node)
11472 return error_mark_node;
11474 /* As an optimization, we avoid regenerating the array type if
11475 it will obviously be the same as T. */
11476 if (type == TREE_TYPE (t) && domain == TYPE_DOMAIN (t))
11479 /* These checks should match the ones in grokdeclarator.
11483 The deduction may fail for any of the following reasons:
11485 -- Attempting to create an array with an element type that
11486 is void, a function type, or a reference type, or [DR337]
11487 an abstract class type. */
11488 if (TREE_CODE (type) == VOID_TYPE
11489 || TREE_CODE (type) == FUNCTION_TYPE
11490 || TREE_CODE (type) == REFERENCE_TYPE)
11492 if (complain & tf_error)
11493 error ("creating array of %qT", type);
11494 return error_mark_node;
11496 if (CLASS_TYPE_P (type) && CLASSTYPE_PURE_VIRTUALS (type))
11498 if (complain & tf_error)
11499 error ("creating array of %qT, which is an abstract class type",
11501 return error_mark_node;
11504 r = build_cplus_array_type (type, domain);
11506 if (TYPE_USER_ALIGN (t))
11508 TYPE_ALIGN (r) = TYPE_ALIGN (t);
11509 TYPE_USER_ALIGN (r) = 1;
11515 case TYPENAME_TYPE:
11517 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
11518 in_decl, /*entering_scope=*/1);
11519 tree f = tsubst_copy (TYPENAME_TYPE_FULLNAME (t), args,
11520 complain, in_decl);
11522 if (ctx == error_mark_node || f == error_mark_node)
11523 return error_mark_node;
11525 if (!MAYBE_CLASS_TYPE_P (ctx))
11527 if (complain & tf_error)
11528 error ("%qT is not a class, struct, or union type", ctx);
11529 return error_mark_node;
11531 else if (!uses_template_parms (ctx) && !TYPE_BEING_DEFINED (ctx))
11533 /* Normally, make_typename_type does not require that the CTX
11534 have complete type in order to allow things like:
11536 template <class T> struct S { typename S<T>::X Y; };
11538 But, such constructs have already been resolved by this
11539 point, so here CTX really should have complete type, unless
11540 it's a partial instantiation. */
11541 ctx = complete_type (ctx);
11542 if (!COMPLETE_TYPE_P (ctx))
11544 if (complain & tf_error)
11545 cxx_incomplete_type_error (NULL_TREE, ctx);
11546 return error_mark_node;
11550 f = make_typename_type (ctx, f, typename_type,
11551 (complain & tf_error) | tf_keep_type_decl);
11552 if (f == error_mark_node)
11554 if (TREE_CODE (f) == TYPE_DECL)
11556 complain |= tf_ignore_bad_quals;
11560 if (TREE_CODE (f) != TYPENAME_TYPE)
11562 if (TYPENAME_IS_ENUM_P (t) && TREE_CODE (f) != ENUMERAL_TYPE)
11564 if (complain & tf_error)
11565 error ("%qT resolves to %qT, which is not an enumeration type",
11568 return error_mark_node;
11570 else if (TYPENAME_IS_CLASS_P (t) && !CLASS_TYPE_P (f))
11572 if (complain & tf_error)
11573 error ("%qT resolves to %qT, which is is not a class type",
11576 return error_mark_node;
11580 return cp_build_qualified_type_real
11581 (f, cp_type_quals (f) | cp_type_quals (t), complain);
11584 case UNBOUND_CLASS_TEMPLATE:
11586 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
11587 in_decl, /*entering_scope=*/1);
11588 tree name = TYPE_IDENTIFIER (t);
11589 tree parm_list = DECL_TEMPLATE_PARMS (TYPE_NAME (t));
11591 if (ctx == error_mark_node || name == error_mark_node)
11592 return error_mark_node;
11595 parm_list = tsubst_template_parms (parm_list, args, complain);
11596 return make_unbound_class_template (ctx, name, parm_list, complain);
11603 ++cp_unevaluated_operand;
11604 ++c_inhibit_evaluation_warnings;
11606 type = tsubst_expr (TYPEOF_TYPE_EXPR (t), args,
11608 /*integral_constant_expression_p=*/false);
11610 --cp_unevaluated_operand;
11611 --c_inhibit_evaluation_warnings;
11613 type = finish_typeof (type);
11614 return cp_build_qualified_type_real (type,
11616 | cp_type_quals (type),
11620 case DECLTYPE_TYPE:
11624 ++cp_unevaluated_operand;
11625 ++c_inhibit_evaluation_warnings;
11627 type = tsubst_expr (DECLTYPE_TYPE_EXPR (t), args,
11629 /*integral_constant_expression_p=*/false);
11631 --cp_unevaluated_operand;
11632 --c_inhibit_evaluation_warnings;
11634 if (DECLTYPE_FOR_LAMBDA_CAPTURE (t))
11635 type = lambda_capture_field_type (type);
11636 else if (DECLTYPE_FOR_LAMBDA_PROXY (t))
11637 type = lambda_proxy_type (type);
11639 type = finish_decltype_type
11640 (type, DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t), complain);
11641 return cp_build_qualified_type_real (type,
11643 | cp_type_quals (type),
11647 case UNDERLYING_TYPE:
11649 tree type = tsubst (UNDERLYING_TYPE_TYPE (t), args,
11650 complain, in_decl);
11651 return finish_underlying_type (type);
11654 case TYPE_ARGUMENT_PACK:
11655 case NONTYPE_ARGUMENT_PACK:
11657 tree r = TYPE_P (t) ? cxx_make_type (code) : make_node (code);
11659 tsubst_template_args (ARGUMENT_PACK_ARGS (t),
11663 SET_ARGUMENT_PACK_ARGS (r, packed_out);
11665 /* For template nontype argument packs, also substitute into
11667 if (code == NONTYPE_ARGUMENT_PACK)
11668 TREE_TYPE (r) = tsubst (TREE_TYPE (t), args, complain, in_decl);
11686 /* We should use one of the expression tsubsts for these codes. */
11687 gcc_unreachable ();
11690 sorry ("use of %qs in template", tree_code_name [(int) code]);
11691 return error_mark_node;
11695 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
11696 type of the expression on the left-hand side of the "." or "->"
11700 tsubst_baselink (tree baselink, tree object_type,
11701 tree args, tsubst_flags_t complain, tree in_decl)
11704 tree qualifying_scope;
11707 tree template_args = 0;
11708 bool template_id_p = false;
11710 /* A baselink indicates a function from a base class. Both the
11711 BASELINK_ACCESS_BINFO and the base class referenced may
11712 indicate bases of the template class, rather than the
11713 instantiated class. In addition, lookups that were not
11714 ambiguous before may be ambiguous now. Therefore, we perform
11715 the lookup again. */
11716 qualifying_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (baselink));
11717 qualifying_scope = tsubst (qualifying_scope, args,
11718 complain, in_decl);
11719 fns = BASELINK_FUNCTIONS (baselink);
11720 optype = tsubst (BASELINK_OPTYPE (baselink), args, complain, in_decl);
11721 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
11723 template_id_p = true;
11724 template_args = TREE_OPERAND (fns, 1);
11725 fns = TREE_OPERAND (fns, 0);
11727 template_args = tsubst_template_args (template_args, args,
11728 complain, in_decl);
11730 name = DECL_NAME (get_first_fn (fns));
11731 if (IDENTIFIER_TYPENAME_P (name))
11732 name = mangle_conv_op_name_for_type (optype);
11733 baselink = lookup_fnfields (qualifying_scope, name, /*protect=*/1);
11735 return error_mark_node;
11737 /* If lookup found a single function, mark it as used at this
11738 point. (If it lookup found multiple functions the one selected
11739 later by overload resolution will be marked as used at that
11741 if (BASELINK_P (baselink))
11742 fns = BASELINK_FUNCTIONS (baselink);
11743 if (!template_id_p && !really_overloaded_fn (fns))
11744 mark_used (OVL_CURRENT (fns));
11746 /* Add back the template arguments, if present. */
11747 if (BASELINK_P (baselink) && template_id_p)
11748 BASELINK_FUNCTIONS (baselink)
11749 = build_nt (TEMPLATE_ID_EXPR,
11750 BASELINK_FUNCTIONS (baselink),
11752 /* Update the conversion operator type. */
11753 BASELINK_OPTYPE (baselink) = optype;
11756 object_type = current_class_type;
11757 return adjust_result_of_qualified_name_lookup (baselink,
11762 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
11763 true if the qualified-id will be a postfix-expression in-and-of
11764 itself; false if more of the postfix-expression follows the
11765 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
11769 tsubst_qualified_id (tree qualified_id, tree args,
11770 tsubst_flags_t complain, tree in_decl,
11771 bool done, bool address_p)
11777 tree template_args;
11779 gcc_assert (TREE_CODE (qualified_id) == SCOPE_REF);
11781 /* Figure out what name to look up. */
11782 name = TREE_OPERAND (qualified_id, 1);
11783 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
11785 is_template = true;
11786 template_args = TREE_OPERAND (name, 1);
11788 template_args = tsubst_template_args (template_args, args,
11789 complain, in_decl);
11790 name = TREE_OPERAND (name, 0);
11794 is_template = false;
11795 template_args = NULL_TREE;
11798 /* Substitute into the qualifying scope. When there are no ARGS, we
11799 are just trying to simplify a non-dependent expression. In that
11800 case the qualifying scope may be dependent, and, in any case,
11801 substituting will not help. */
11802 scope = TREE_OPERAND (qualified_id, 0);
11805 scope = tsubst (scope, args, complain, in_decl);
11806 expr = tsubst_copy (name, args, complain, in_decl);
11811 if (dependent_scope_p (scope))
11814 expr = build_min_nt (TEMPLATE_ID_EXPR, expr, template_args);
11815 return build_qualified_name (NULL_TREE, scope, expr,
11816 QUALIFIED_NAME_IS_TEMPLATE (qualified_id));
11819 if (!BASELINK_P (name) && !DECL_P (expr))
11821 if (TREE_CODE (expr) == BIT_NOT_EXPR)
11823 /* A BIT_NOT_EXPR is used to represent a destructor. */
11824 if (!check_dtor_name (scope, TREE_OPERAND (expr, 0)))
11826 error ("qualifying type %qT does not match destructor name ~%qT",
11827 scope, TREE_OPERAND (expr, 0));
11828 expr = error_mark_node;
11831 expr = lookup_qualified_name (scope, complete_dtor_identifier,
11832 /*is_type_p=*/0, false);
11835 expr = lookup_qualified_name (scope, expr, /*is_type_p=*/0, false);
11836 if (TREE_CODE (TREE_CODE (expr) == TEMPLATE_DECL
11837 ? DECL_TEMPLATE_RESULT (expr) : expr) == TYPE_DECL)
11839 if (complain & tf_error)
11841 error ("dependent-name %qE is parsed as a non-type, but "
11842 "instantiation yields a type", qualified_id);
11843 inform (input_location, "say %<typename %E%> if a type is meant", qualified_id);
11845 return error_mark_node;
11851 check_accessibility_of_qualified_id (expr, /*object_type=*/NULL_TREE,
11853 /* Remember that there was a reference to this entity. */
11857 if (expr == error_mark_node || TREE_CODE (expr) == TREE_LIST)
11859 if (complain & tf_error)
11860 qualified_name_lookup_error (scope,
11861 TREE_OPERAND (qualified_id, 1),
11862 expr, input_location);
11863 return error_mark_node;
11867 expr = lookup_template_function (expr, template_args);
11869 if (expr == error_mark_node && complain & tf_error)
11870 qualified_name_lookup_error (scope, TREE_OPERAND (qualified_id, 1),
11871 expr, input_location);
11872 else if (TYPE_P (scope))
11874 expr = (adjust_result_of_qualified_name_lookup
11875 (expr, scope, current_class_type));
11876 expr = (finish_qualified_id_expr
11877 (scope, expr, done, address_p && PTRMEM_OK_P (qualified_id),
11878 QUALIFIED_NAME_IS_TEMPLATE (qualified_id),
11879 /*template_arg_p=*/false));
11882 /* Expressions do not generally have reference type. */
11883 if (TREE_CODE (expr) != SCOPE_REF
11884 /* However, if we're about to form a pointer-to-member, we just
11885 want the referenced member referenced. */
11886 && TREE_CODE (expr) != OFFSET_REF)
11887 expr = convert_from_reference (expr);
11892 /* Like tsubst, but deals with expressions. This function just replaces
11893 template parms; to finish processing the resultant expression, use
11894 tsubst_copy_and_build or tsubst_expr. */
11897 tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl)
11899 enum tree_code code;
11902 if (t == NULL_TREE || t == error_mark_node || args == NULL_TREE)
11905 code = TREE_CODE (t);
11910 r = retrieve_local_specialization (t);
11916 /* We get here for a use of 'this' in an NSDMI. */
11917 if (DECL_NAME (t) == this_identifier
11918 && at_function_scope_p ()
11919 && DECL_CONSTRUCTOR_P (current_function_decl))
11920 return current_class_ptr;
11922 /* This can happen for a parameter name used later in a function
11923 declaration (such as in a late-specified return type). Just
11924 make a dummy decl, since it's only used for its type. */
11925 gcc_assert (cp_unevaluated_operand != 0);
11926 /* We copy T because want to tsubst the PARM_DECL only,
11927 not the following PARM_DECLs that are chained to T. */
11929 r = tsubst_decl (c, args, complain);
11930 /* Give it the template pattern as its context; its true context
11931 hasn't been instantiated yet and this is good enough for
11933 DECL_CONTEXT (r) = DECL_CONTEXT (t);
11936 if (TREE_CODE (r) == ARGUMENT_PACK_SELECT)
11937 r = ARGUMENT_PACK_SELECT_ARG (r);
11946 if (DECL_TEMPLATE_PARM_P (t))
11947 return tsubst_copy (DECL_INITIAL (t), args, complain, in_decl);
11948 /* There is no need to substitute into namespace-scope
11950 if (DECL_NAMESPACE_SCOPE_P (t))
11952 /* If ARGS is NULL, then T is known to be non-dependent. */
11953 if (args == NULL_TREE)
11954 return integral_constant_value (t);
11956 /* Unfortunately, we cannot just call lookup_name here.
11959 template <int I> int f() {
11961 struct S { void g() { E e = a; } };
11964 When we instantiate f<7>::S::g(), say, lookup_name is not
11965 clever enough to find f<7>::a. */
11967 = tsubst_aggr_type (TREE_TYPE (t), args, complain, in_decl,
11968 /*entering_scope=*/0);
11970 for (v = TYPE_VALUES (enum_type);
11972 v = TREE_CHAIN (v))
11973 if (TREE_PURPOSE (v) == DECL_NAME (t))
11974 return TREE_VALUE (v);
11976 /* We didn't find the name. That should never happen; if
11977 name-lookup found it during preliminary parsing, we
11978 should find it again here during instantiation. */
11979 gcc_unreachable ();
11984 if (DECL_CONTEXT (t))
11988 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args, complain, in_decl,
11989 /*entering_scope=*/1);
11990 if (ctx != DECL_CONTEXT (t))
11992 tree r = lookup_field (ctx, DECL_NAME (t), 0, false);
11995 if (complain & tf_error)
11996 error ("using invalid field %qD", t);
11997 return error_mark_node;
12006 case FUNCTION_DECL:
12007 if ((DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t))
12008 || local_variable_p (t))
12009 t = tsubst (t, args, complain, in_decl);
12013 case NAMESPACE_DECL:
12017 /* An OVERLOAD will always be a non-dependent overload set; an
12018 overload set from function scope will just be represented with an
12019 IDENTIFIER_NODE, and from class scope with a BASELINK. */
12020 gcc_assert (!uses_template_parms (t));
12024 return tsubst_baselink (t, current_class_type, args, complain, in_decl);
12026 case TEMPLATE_DECL:
12027 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
12028 return tsubst (TREE_TYPE (DECL_TEMPLATE_RESULT (t)),
12029 args, complain, in_decl);
12030 else if (DECL_FUNCTION_TEMPLATE_P (t) && DECL_MEMBER_TEMPLATE_P (t))
12031 return tsubst (t, args, complain, in_decl);
12032 else if (DECL_CLASS_SCOPE_P (t)
12033 && uses_template_parms (DECL_CONTEXT (t)))
12035 /* Template template argument like the following example need
12038 template <template <class> class TT> struct C {};
12039 template <class T> struct D {
12040 template <class U> struct E {};
12045 We are processing the template argument `E' in #1 for
12046 the template instantiation #2. Originally, `E' is a
12047 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
12048 have to substitute this with one having context `D<int>'. */
12050 tree context = tsubst (DECL_CONTEXT (t), args, complain, in_decl);
12051 return lookup_field (context, DECL_NAME(t), 0, false);
12054 /* Ordinary template template argument. */
12058 case REINTERPRET_CAST_EXPR:
12059 case CONST_CAST_EXPR:
12060 case STATIC_CAST_EXPR:
12061 case DYNAMIC_CAST_EXPR:
12062 case IMPLICIT_CONV_EXPR:
12066 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
12067 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
12070 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
12076 ++cp_unevaluated_operand;
12077 ++c_inhibit_evaluation_warnings;
12078 /* We only want to compute the number of arguments. */
12079 expanded = tsubst_pack_expansion (TREE_OPERAND (t, 0), args,
12080 complain, in_decl);
12081 --cp_unevaluated_operand;
12082 --c_inhibit_evaluation_warnings;
12084 if (TREE_CODE (expanded) == TREE_VEC)
12085 len = TREE_VEC_LENGTH (expanded);
12087 if (expanded == error_mark_node)
12088 return error_mark_node;
12089 else if (PACK_EXPANSION_P (expanded)
12090 || (TREE_CODE (expanded) == TREE_VEC
12092 && PACK_EXPANSION_P (TREE_VEC_ELT (expanded, len-1))))
12094 if (TREE_CODE (expanded) == TREE_VEC)
12095 expanded = TREE_VEC_ELT (expanded, len - 1);
12097 if (TYPE_P (expanded))
12098 return cxx_sizeof_or_alignof_type (expanded, SIZEOF_EXPR,
12099 complain & tf_error);
12101 return cxx_sizeof_or_alignof_expr (expanded, SIZEOF_EXPR,
12102 complain & tf_error);
12105 return build_int_cst (size_type_node, len);
12111 case TRUTH_NOT_EXPR:
12114 case UNARY_PLUS_EXPR: /* Unary + */
12116 case AT_ENCODE_EXPR:
12120 case REALPART_EXPR:
12121 case IMAGPART_EXPR:
12123 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
12124 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
12126 case COMPONENT_REF:
12131 object = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
12132 name = TREE_OPERAND (t, 1);
12133 if (TREE_CODE (name) == BIT_NOT_EXPR)
12135 name = tsubst_copy (TREE_OPERAND (name, 0), args,
12136 complain, in_decl);
12137 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
12139 else if (TREE_CODE (name) == SCOPE_REF
12140 && TREE_CODE (TREE_OPERAND (name, 1)) == BIT_NOT_EXPR)
12142 tree base = tsubst_copy (TREE_OPERAND (name, 0), args,
12143 complain, in_decl);
12144 name = TREE_OPERAND (name, 1);
12145 name = tsubst_copy (TREE_OPERAND (name, 0), args,
12146 complain, in_decl);
12147 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
12148 name = build_qualified_name (/*type=*/NULL_TREE,
12150 /*template_p=*/false);
12152 else if (BASELINK_P (name))
12153 name = tsubst_baselink (name,
12154 non_reference (TREE_TYPE (object)),
12158 name = tsubst_copy (name, args, complain, in_decl);
12159 return build_nt (COMPONENT_REF, object, name, NULL_TREE);
12165 case TRUNC_DIV_EXPR:
12166 case CEIL_DIV_EXPR:
12167 case FLOOR_DIV_EXPR:
12168 case ROUND_DIV_EXPR:
12169 case EXACT_DIV_EXPR:
12173 case TRUNC_MOD_EXPR:
12174 case FLOOR_MOD_EXPR:
12175 case TRUTH_ANDIF_EXPR:
12176 case TRUTH_ORIF_EXPR:
12177 case TRUTH_AND_EXPR:
12178 case TRUTH_OR_EXPR:
12191 case COMPOUND_EXPR:
12194 case PREDECREMENT_EXPR:
12195 case PREINCREMENT_EXPR:
12196 case POSTDECREMENT_EXPR:
12197 case POSTINCREMENT_EXPR:
12199 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12200 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
12203 return build_qualified_name (/*type=*/NULL_TREE,
12204 tsubst_copy (TREE_OPERAND (t, 0),
12205 args, complain, in_decl),
12206 tsubst_copy (TREE_OPERAND (t, 1),
12207 args, complain, in_decl),
12208 QUALIFIED_NAME_IS_TEMPLATE (t));
12213 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12214 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
12215 NULL_TREE, NULL_TREE);
12219 int n = VL_EXP_OPERAND_LENGTH (t);
12220 tree result = build_vl_exp (CALL_EXPR, n);
12222 for (i = 0; i < n; i++)
12223 TREE_OPERAND (t, i) = tsubst_copy (TREE_OPERAND (t, i), args,
12224 complain, in_decl);
12230 case PSEUDO_DTOR_EXPR:
12233 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12234 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
12235 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
12236 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
12243 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12244 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
12245 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
12246 NEW_EXPR_USE_GLOBAL (r) = NEW_EXPR_USE_GLOBAL (t);
12253 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12254 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
12255 DELETE_EXPR_USE_GLOBAL (r) = DELETE_EXPR_USE_GLOBAL (t);
12256 DELETE_EXPR_USE_VEC (r) = DELETE_EXPR_USE_VEC (t);
12260 case TEMPLATE_ID_EXPR:
12262 /* Substituted template arguments */
12263 tree fn = TREE_OPERAND (t, 0);
12264 tree targs = TREE_OPERAND (t, 1);
12266 fn = tsubst_copy (fn, args, complain, in_decl);
12268 targs = tsubst_template_args (targs, args, complain, in_decl);
12270 return lookup_template_function (fn, targs);
12275 tree purpose, value, chain;
12277 if (t == void_list_node)
12280 purpose = TREE_PURPOSE (t);
12282 purpose = tsubst_copy (purpose, args, complain, in_decl);
12283 value = TREE_VALUE (t);
12285 value = tsubst_copy (value, args, complain, in_decl);
12286 chain = TREE_CHAIN (t);
12287 if (chain && chain != void_type_node)
12288 chain = tsubst_copy (chain, args, complain, in_decl);
12289 if (purpose == TREE_PURPOSE (t)
12290 && value == TREE_VALUE (t)
12291 && chain == TREE_CHAIN (t))
12293 return tree_cons (purpose, value, chain);
12298 case ENUMERAL_TYPE:
12300 case TEMPLATE_TYPE_PARM:
12301 case TEMPLATE_TEMPLATE_PARM:
12302 case BOUND_TEMPLATE_TEMPLATE_PARM:
12303 case TEMPLATE_PARM_INDEX:
12305 case REFERENCE_TYPE:
12307 case FUNCTION_TYPE:
12310 case TYPENAME_TYPE:
12311 case UNBOUND_CLASS_TEMPLATE:
12313 case DECLTYPE_TYPE:
12315 return tsubst (t, args, complain, in_decl);
12317 case IDENTIFIER_NODE:
12318 if (IDENTIFIER_TYPENAME_P (t))
12320 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12321 return mangle_conv_op_name_for_type (new_type);
12327 /* This is handled by tsubst_copy_and_build. */
12328 gcc_unreachable ();
12331 return build_x_va_arg (tsubst_copy (TREE_OPERAND (t, 0), args, complain,
12333 tsubst (TREE_TYPE (t), args, complain, in_decl));
12335 case CLEANUP_POINT_EXPR:
12336 /* We shouldn't have built any of these during initial template
12337 generation. Instead, they should be built during instantiation
12338 in response to the saved STMT_IS_FULL_EXPR_P setting. */
12339 gcc_unreachable ();
12343 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
12344 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12345 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
12346 PTRMEM_OK_P (r) = PTRMEM_OK_P (t);
12347 mark_used (TREE_OPERAND (r, 1));
12350 case EXPR_PACK_EXPANSION:
12351 error ("invalid use of pack expansion expression");
12352 return error_mark_node;
12354 case NONTYPE_ARGUMENT_PACK:
12355 error ("use %<...%> to expand argument pack");
12356 return error_mark_node;
12363 /* Instantiate any typedefs in the type. */
12364 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12365 r = fold_convert (type, t);
12366 gcc_assert (TREE_CODE (r) == code);
12371 /* These can sometimes show up in a partial instantiation, but never
12372 involve template parms. */
12373 gcc_assert (!uses_template_parms (t));
12377 /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */
12378 gcc_checking_assert (false);
12383 /* Like tsubst_copy, but specifically for OpenMP clauses. */
12386 tsubst_omp_clauses (tree clauses, tree args, tsubst_flags_t complain,
12389 tree new_clauses = NULL, nc, oc;
12391 for (oc = clauses; oc ; oc = OMP_CLAUSE_CHAIN (oc))
12393 nc = copy_node (oc);
12394 OMP_CLAUSE_CHAIN (nc) = new_clauses;
12397 switch (OMP_CLAUSE_CODE (nc))
12399 case OMP_CLAUSE_LASTPRIVATE:
12400 if (OMP_CLAUSE_LASTPRIVATE_STMT (oc))
12402 OMP_CLAUSE_LASTPRIVATE_STMT (nc) = push_stmt_list ();
12403 tsubst_expr (OMP_CLAUSE_LASTPRIVATE_STMT (oc), args, complain,
12404 in_decl, /*integral_constant_expression_p=*/false);
12405 OMP_CLAUSE_LASTPRIVATE_STMT (nc)
12406 = pop_stmt_list (OMP_CLAUSE_LASTPRIVATE_STMT (nc));
12409 case OMP_CLAUSE_PRIVATE:
12410 case OMP_CLAUSE_SHARED:
12411 case OMP_CLAUSE_FIRSTPRIVATE:
12412 case OMP_CLAUSE_REDUCTION:
12413 case OMP_CLAUSE_COPYIN:
12414 case OMP_CLAUSE_COPYPRIVATE:
12415 case OMP_CLAUSE_IF:
12416 case OMP_CLAUSE_NUM_THREADS:
12417 case OMP_CLAUSE_SCHEDULE:
12418 case OMP_CLAUSE_COLLAPSE:
12419 case OMP_CLAUSE_FINAL:
12420 OMP_CLAUSE_OPERAND (nc, 0)
12421 = tsubst_expr (OMP_CLAUSE_OPERAND (oc, 0), args, complain,
12422 in_decl, /*integral_constant_expression_p=*/false);
12424 case OMP_CLAUSE_NOWAIT:
12425 case OMP_CLAUSE_ORDERED:
12426 case OMP_CLAUSE_DEFAULT:
12427 case OMP_CLAUSE_UNTIED:
12428 case OMP_CLAUSE_MERGEABLE:
12431 gcc_unreachable ();
12435 return finish_omp_clauses (nreverse (new_clauses));
12438 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
12441 tsubst_copy_asm_operands (tree t, tree args, tsubst_flags_t complain,
12444 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
12446 tree purpose, value, chain;
12451 if (TREE_CODE (t) != TREE_LIST)
12452 return tsubst_copy_and_build (t, args, complain, in_decl,
12453 /*function_p=*/false,
12454 /*integral_constant_expression_p=*/false);
12456 if (t == void_list_node)
12459 purpose = TREE_PURPOSE (t);
12461 purpose = RECUR (purpose);
12462 value = TREE_VALUE (t);
12463 if (value && TREE_CODE (value) != LABEL_DECL)
12464 value = RECUR (value);
12465 chain = TREE_CHAIN (t);
12466 if (chain && chain != void_type_node)
12467 chain = RECUR (chain);
12468 return tree_cons (purpose, value, chain);
12472 /* Substitute one OMP_FOR iterator. */
12475 tsubst_omp_for_iterator (tree t, int i, tree declv, tree initv,
12476 tree condv, tree incrv, tree *clauses,
12477 tree args, tsubst_flags_t complain, tree in_decl,
12478 bool integral_constant_expression_p)
12480 #define RECUR(NODE) \
12481 tsubst_expr ((NODE), args, complain, in_decl, \
12482 integral_constant_expression_p)
12483 tree decl, init, cond, incr, auto_node;
12485 init = TREE_VEC_ELT (OMP_FOR_INIT (t), i);
12486 gcc_assert (TREE_CODE (init) == MODIFY_EXPR);
12487 decl = RECUR (TREE_OPERAND (init, 0));
12488 init = TREE_OPERAND (init, 1);
12489 auto_node = type_uses_auto (TREE_TYPE (decl));
12490 if (auto_node && init)
12492 tree init_expr = init;
12493 if (TREE_CODE (init_expr) == DECL_EXPR)
12494 init_expr = DECL_INITIAL (DECL_EXPR_DECL (init_expr));
12495 init_expr = RECUR (init_expr);
12497 = do_auto_deduction (TREE_TYPE (decl), init_expr, auto_node);
12499 gcc_assert (!type_dependent_expression_p (decl));
12501 if (!CLASS_TYPE_P (TREE_TYPE (decl)))
12503 cond = RECUR (TREE_VEC_ELT (OMP_FOR_COND (t), i));
12504 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
12505 if (TREE_CODE (incr) == MODIFY_EXPR)
12506 incr = build_x_modify_expr (RECUR (TREE_OPERAND (incr, 0)), NOP_EXPR,
12507 RECUR (TREE_OPERAND (incr, 1)),
12510 incr = RECUR (incr);
12511 TREE_VEC_ELT (declv, i) = decl;
12512 TREE_VEC_ELT (initv, i) = init;
12513 TREE_VEC_ELT (condv, i) = cond;
12514 TREE_VEC_ELT (incrv, i) = incr;
12518 if (init && TREE_CODE (init) != DECL_EXPR)
12521 for (c = *clauses; c ; c = OMP_CLAUSE_CHAIN (c))
12523 if ((OMP_CLAUSE_CODE (c) == OMP_CLAUSE_PRIVATE
12524 || OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LASTPRIVATE)
12525 && OMP_CLAUSE_DECL (c) == decl)
12527 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_FIRSTPRIVATE
12528 && OMP_CLAUSE_DECL (c) == decl)
12529 error ("iteration variable %qD should not be firstprivate", decl);
12530 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_REDUCTION
12531 && OMP_CLAUSE_DECL (c) == decl)
12532 error ("iteration variable %qD should not be reduction", decl);
12536 c = build_omp_clause (input_location, OMP_CLAUSE_PRIVATE);
12537 OMP_CLAUSE_DECL (c) = decl;
12538 c = finish_omp_clauses (c);
12541 OMP_CLAUSE_CHAIN (c) = *clauses;
12546 cond = TREE_VEC_ELT (OMP_FOR_COND (t), i);
12547 if (COMPARISON_CLASS_P (cond))
12548 cond = build2 (TREE_CODE (cond), boolean_type_node,
12549 RECUR (TREE_OPERAND (cond, 0)),
12550 RECUR (TREE_OPERAND (cond, 1)));
12552 cond = RECUR (cond);
12553 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
12554 switch (TREE_CODE (incr))
12556 case PREINCREMENT_EXPR:
12557 case PREDECREMENT_EXPR:
12558 case POSTINCREMENT_EXPR:
12559 case POSTDECREMENT_EXPR:
12560 incr = build2 (TREE_CODE (incr), TREE_TYPE (decl),
12561 RECUR (TREE_OPERAND (incr, 0)), NULL_TREE);
12564 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
12565 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
12567 tree rhs = TREE_OPERAND (incr, 1);
12568 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
12569 RECUR (TREE_OPERAND (incr, 0)),
12570 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
12571 RECUR (TREE_OPERAND (rhs, 0)),
12572 RECUR (TREE_OPERAND (rhs, 1))));
12575 incr = RECUR (incr);
12578 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
12579 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
12581 tree lhs = RECUR (TREE_OPERAND (incr, 0));
12582 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl), lhs,
12583 build2 (TREE_CODE (TREE_OPERAND (incr, 1)),
12584 TREE_TYPE (decl), lhs,
12585 RECUR (TREE_OPERAND (incr, 2))));
12587 else if (TREE_CODE (TREE_OPERAND (incr, 1)) == NOP_EXPR
12588 && (TREE_CODE (TREE_OPERAND (incr, 2)) == PLUS_EXPR
12589 || (TREE_CODE (TREE_OPERAND (incr, 2)) == MINUS_EXPR)))
12591 tree rhs = TREE_OPERAND (incr, 2);
12592 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
12593 RECUR (TREE_OPERAND (incr, 0)),
12594 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
12595 RECUR (TREE_OPERAND (rhs, 0)),
12596 RECUR (TREE_OPERAND (rhs, 1))));
12599 incr = RECUR (incr);
12602 incr = RECUR (incr);
12606 TREE_VEC_ELT (declv, i) = decl;
12607 TREE_VEC_ELT (initv, i) = init;
12608 TREE_VEC_ELT (condv, i) = cond;
12609 TREE_VEC_ELT (incrv, i) = incr;
12613 /* Like tsubst_copy for expressions, etc. but also does semantic
12617 tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl,
12618 bool integral_constant_expression_p)
12620 #define RECUR(NODE) \
12621 tsubst_expr ((NODE), args, complain, in_decl, \
12622 integral_constant_expression_p)
12626 if (t == NULL_TREE || t == error_mark_node)
12629 if (EXPR_HAS_LOCATION (t))
12630 input_location = EXPR_LOCATION (t);
12631 if (STATEMENT_CODE_P (TREE_CODE (t)))
12632 current_stmt_tree ()->stmts_are_full_exprs_p = STMT_IS_FULL_EXPR_P (t);
12634 switch (TREE_CODE (t))
12636 case STATEMENT_LIST:
12638 tree_stmt_iterator i;
12639 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
12640 RECUR (tsi_stmt (i));
12644 case CTOR_INITIALIZER:
12645 finish_mem_initializers (tsubst_initializer_list
12646 (TREE_OPERAND (t, 0), args));
12650 finish_return_stmt (RECUR (TREE_OPERAND (t, 0)));
12654 tmp = RECUR (EXPR_STMT_EXPR (t));
12655 if (EXPR_STMT_STMT_EXPR_RESULT (t))
12656 finish_stmt_expr_expr (tmp, cur_stmt_expr);
12658 finish_expr_stmt (tmp);
12662 do_using_directive (USING_STMT_NAMESPACE (t));
12667 tree decl, pattern_decl;
12670 pattern_decl = decl = DECL_EXPR_DECL (t);
12671 if (TREE_CODE (decl) == LABEL_DECL)
12672 finish_label_decl (DECL_NAME (decl));
12673 else if (TREE_CODE (decl) == USING_DECL)
12675 tree scope = USING_DECL_SCOPE (decl);
12676 tree name = DECL_NAME (decl);
12679 scope = tsubst (scope, args, complain, in_decl);
12680 decl = lookup_qualified_name (scope, name,
12681 /*is_type_p=*/false,
12682 /*complain=*/false);
12683 if (decl == error_mark_node || TREE_CODE (decl) == TREE_LIST)
12684 qualified_name_lookup_error (scope, name, decl, input_location);
12686 do_local_using_decl (decl, scope, name);
12690 init = DECL_INITIAL (decl);
12691 decl = tsubst (decl, args, complain, in_decl);
12692 if (decl != error_mark_node)
12694 /* By marking the declaration as instantiated, we avoid
12695 trying to instantiate it. Since instantiate_decl can't
12696 handle local variables, and since we've already done
12697 all that needs to be done, that's the right thing to
12699 if (TREE_CODE (decl) == VAR_DECL)
12700 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
12701 if (TREE_CODE (decl) == VAR_DECL
12702 && ANON_AGGR_TYPE_P (TREE_TYPE (decl)))
12703 /* Anonymous aggregates are a special case. */
12704 finish_anon_union (decl);
12707 int const_init = false;
12708 maybe_push_decl (decl);
12709 if (TREE_CODE (decl) == VAR_DECL
12710 && DECL_PRETTY_FUNCTION_P (decl))
12712 /* For __PRETTY_FUNCTION__ we have to adjust the
12714 const char *const name
12715 = cxx_printable_name (current_function_decl, 2);
12716 init = cp_fname_init (name, &TREE_TYPE (decl));
12720 tree t = RECUR (init);
12724 /* If we had an initializer but it
12725 instantiated to nothing,
12726 value-initialize the object. This will
12727 only occur when the initializer was a
12728 pack expansion where the parameter packs
12729 used in that expansion were of length
12731 init = build_value_init (TREE_TYPE (decl),
12733 if (TREE_CODE (init) == AGGR_INIT_EXPR)
12734 init = get_target_expr_sfinae (init, complain);
12740 if (TREE_CODE (decl) == VAR_DECL)
12741 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
12743 cp_finish_decl (decl, init, const_init, NULL_TREE, 0);
12748 /* A DECL_EXPR can also be used as an expression, in the condition
12749 clause of an if/for/while construct. */
12754 stmt = begin_for_stmt (NULL_TREE, NULL_TREE);
12755 RECUR (FOR_INIT_STMT (t));
12756 finish_for_init_stmt (stmt);
12757 tmp = RECUR (FOR_COND (t));
12758 finish_for_cond (tmp, stmt);
12759 tmp = RECUR (FOR_EXPR (t));
12760 finish_for_expr (tmp, stmt);
12761 RECUR (FOR_BODY (t));
12762 finish_for_stmt (stmt);
12765 case RANGE_FOR_STMT:
12768 stmt = begin_for_stmt (NULL_TREE, NULL_TREE);
12769 decl = RANGE_FOR_DECL (t);
12770 decl = tsubst (decl, args, complain, in_decl);
12771 maybe_push_decl (decl);
12772 expr = RECUR (RANGE_FOR_EXPR (t));
12773 stmt = cp_convert_range_for (stmt, decl, expr);
12774 RECUR (RANGE_FOR_BODY (t));
12775 finish_for_stmt (stmt);
12780 stmt = begin_while_stmt ();
12781 tmp = RECUR (WHILE_COND (t));
12782 finish_while_stmt_cond (tmp, stmt);
12783 RECUR (WHILE_BODY (t));
12784 finish_while_stmt (stmt);
12788 stmt = begin_do_stmt ();
12789 RECUR (DO_BODY (t));
12790 finish_do_body (stmt);
12791 tmp = RECUR (DO_COND (t));
12792 finish_do_stmt (tmp, stmt);
12796 stmt = begin_if_stmt ();
12797 tmp = RECUR (IF_COND (t));
12798 finish_if_stmt_cond (tmp, stmt);
12799 RECUR (THEN_CLAUSE (t));
12800 finish_then_clause (stmt);
12802 if (ELSE_CLAUSE (t))
12804 begin_else_clause (stmt);
12805 RECUR (ELSE_CLAUSE (t));
12806 finish_else_clause (stmt);
12809 finish_if_stmt (stmt);
12813 if (BIND_EXPR_BODY_BLOCK (t))
12814 stmt = begin_function_body ();
12816 stmt = begin_compound_stmt (BIND_EXPR_TRY_BLOCK (t)
12817 ? BCS_TRY_BLOCK : 0);
12819 RECUR (BIND_EXPR_BODY (t));
12821 if (BIND_EXPR_BODY_BLOCK (t))
12822 finish_function_body (stmt);
12824 finish_compound_stmt (stmt);
12828 finish_break_stmt ();
12831 case CONTINUE_STMT:
12832 finish_continue_stmt ();
12836 stmt = begin_switch_stmt ();
12837 tmp = RECUR (SWITCH_STMT_COND (t));
12838 finish_switch_cond (tmp, stmt);
12839 RECUR (SWITCH_STMT_BODY (t));
12840 finish_switch_stmt (stmt);
12843 case CASE_LABEL_EXPR:
12844 finish_case_label (EXPR_LOCATION (t),
12845 RECUR (CASE_LOW (t)),
12846 RECUR (CASE_HIGH (t)));
12851 tree decl = LABEL_EXPR_LABEL (t);
12854 label = finish_label_stmt (DECL_NAME (decl));
12855 if (DECL_ATTRIBUTES (decl) != NULL_TREE)
12856 cplus_decl_attributes (&label, DECL_ATTRIBUTES (decl), 0);
12861 tmp = GOTO_DESTINATION (t);
12862 if (TREE_CODE (tmp) != LABEL_DECL)
12863 /* Computed goto's must be tsubst'd into. On the other hand,
12864 non-computed gotos must not be; the identifier in question
12865 will have no binding. */
12868 tmp = DECL_NAME (tmp);
12869 finish_goto_stmt (tmp);
12873 tmp = finish_asm_stmt
12874 (ASM_VOLATILE_P (t),
12875 RECUR (ASM_STRING (t)),
12876 tsubst_copy_asm_operands (ASM_OUTPUTS (t), args, complain, in_decl),
12877 tsubst_copy_asm_operands (ASM_INPUTS (t), args, complain, in_decl),
12878 tsubst_copy_asm_operands (ASM_CLOBBERS (t), args, complain, in_decl),
12879 tsubst_copy_asm_operands (ASM_LABELS (t), args, complain, in_decl));
12881 tree asm_expr = tmp;
12882 if (TREE_CODE (asm_expr) == CLEANUP_POINT_EXPR)
12883 asm_expr = TREE_OPERAND (asm_expr, 0);
12884 ASM_INPUT_P (asm_expr) = ASM_INPUT_P (t);
12891 stmt = begin_try_block ();
12892 RECUR (TRY_STMTS (t));
12893 finish_cleanup_try_block (stmt);
12894 finish_cleanup (RECUR (TRY_HANDLERS (t)), stmt);
12898 tree compound_stmt = NULL_TREE;
12900 if (FN_TRY_BLOCK_P (t))
12901 stmt = begin_function_try_block (&compound_stmt);
12903 stmt = begin_try_block ();
12905 RECUR (TRY_STMTS (t));
12907 if (FN_TRY_BLOCK_P (t))
12908 finish_function_try_block (stmt);
12910 finish_try_block (stmt);
12912 RECUR (TRY_HANDLERS (t));
12913 if (FN_TRY_BLOCK_P (t))
12914 finish_function_handler_sequence (stmt, compound_stmt);
12916 finish_handler_sequence (stmt);
12922 tree decl = HANDLER_PARMS (t);
12926 decl = tsubst (decl, args, complain, in_decl);
12927 /* Prevent instantiate_decl from trying to instantiate
12928 this variable. We've already done all that needs to be
12930 if (decl != error_mark_node)
12931 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
12933 stmt = begin_handler ();
12934 finish_handler_parms (decl, stmt);
12935 RECUR (HANDLER_BODY (t));
12936 finish_handler (stmt);
12941 tsubst (TREE_TYPE (t), args, complain, NULL_TREE);
12944 case STATIC_ASSERT:
12947 tsubst_expr (STATIC_ASSERT_CONDITION (t),
12950 /*integral_constant_expression_p=*/true);
12951 finish_static_assert (condition,
12952 STATIC_ASSERT_MESSAGE (t),
12953 STATIC_ASSERT_SOURCE_LOCATION (t),
12954 /*member_p=*/false);
12959 tmp = tsubst_omp_clauses (OMP_PARALLEL_CLAUSES (t),
12960 args, complain, in_decl);
12961 stmt = begin_omp_parallel ();
12962 RECUR (OMP_PARALLEL_BODY (t));
12963 OMP_PARALLEL_COMBINED (finish_omp_parallel (tmp, stmt))
12964 = OMP_PARALLEL_COMBINED (t);
12968 tmp = tsubst_omp_clauses (OMP_TASK_CLAUSES (t),
12969 args, complain, in_decl);
12970 stmt = begin_omp_task ();
12971 RECUR (OMP_TASK_BODY (t));
12972 finish_omp_task (tmp, stmt);
12977 tree clauses, body, pre_body;
12978 tree declv, initv, condv, incrv;
12981 clauses = tsubst_omp_clauses (OMP_FOR_CLAUSES (t),
12982 args, complain, in_decl);
12983 declv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
12984 initv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
12985 condv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
12986 incrv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
12988 for (i = 0; i < TREE_VEC_LENGTH (OMP_FOR_INIT (t)); i++)
12989 tsubst_omp_for_iterator (t, i, declv, initv, condv, incrv,
12990 &clauses, args, complain, in_decl,
12991 integral_constant_expression_p);
12993 stmt = begin_omp_structured_block ();
12995 for (i = 0; i < TREE_VEC_LENGTH (initv); i++)
12996 if (TREE_VEC_ELT (initv, i) == NULL
12997 || TREE_CODE (TREE_VEC_ELT (initv, i)) != DECL_EXPR)
12998 TREE_VEC_ELT (initv, i) = RECUR (TREE_VEC_ELT (initv, i));
12999 else if (CLASS_TYPE_P (TREE_TYPE (TREE_VEC_ELT (initv, i))))
13001 tree init = RECUR (TREE_VEC_ELT (initv, i));
13002 gcc_assert (init == TREE_VEC_ELT (declv, i));
13003 TREE_VEC_ELT (initv, i) = NULL_TREE;
13007 tree decl_expr = TREE_VEC_ELT (initv, i);
13008 tree init = DECL_INITIAL (DECL_EXPR_DECL (decl_expr));
13009 gcc_assert (init != NULL);
13010 TREE_VEC_ELT (initv, i) = RECUR (init);
13011 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = NULL;
13013 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = init;
13016 pre_body = push_stmt_list ();
13017 RECUR (OMP_FOR_PRE_BODY (t));
13018 pre_body = pop_stmt_list (pre_body);
13020 body = push_stmt_list ();
13021 RECUR (OMP_FOR_BODY (t));
13022 body = pop_stmt_list (body);
13024 t = finish_omp_for (EXPR_LOCATION (t), declv, initv, condv, incrv,
13025 body, pre_body, clauses);
13027 add_stmt (finish_omp_structured_block (stmt));
13033 tmp = tsubst_omp_clauses (OMP_CLAUSES (t), args, complain, in_decl);
13034 stmt = push_stmt_list ();
13035 RECUR (OMP_BODY (t));
13036 stmt = pop_stmt_list (stmt);
13039 OMP_BODY (t) = stmt;
13040 OMP_CLAUSES (t) = tmp;
13048 stmt = push_stmt_list ();
13049 RECUR (OMP_BODY (t));
13050 stmt = pop_stmt_list (stmt);
13053 OMP_BODY (t) = stmt;
13058 gcc_assert (OMP_ATOMIC_DEPENDENT_P (t));
13059 if (TREE_CODE (TREE_OPERAND (t, 1)) != MODIFY_EXPR)
13061 tree op1 = TREE_OPERAND (t, 1);
13062 tree rhs1 = NULL_TREE;
13064 if (TREE_CODE (op1) == COMPOUND_EXPR)
13066 rhs1 = RECUR (TREE_OPERAND (op1, 0));
13067 op1 = TREE_OPERAND (op1, 1);
13069 lhs = RECUR (TREE_OPERAND (op1, 0));
13070 rhs = RECUR (TREE_OPERAND (op1, 1));
13071 finish_omp_atomic (OMP_ATOMIC, TREE_CODE (op1), lhs, rhs,
13072 NULL_TREE, NULL_TREE, rhs1);
13076 tree op1 = TREE_OPERAND (t, 1);
13077 tree v = NULL_TREE, lhs, rhs = NULL_TREE, lhs1 = NULL_TREE;
13078 tree rhs1 = NULL_TREE;
13079 enum tree_code code = TREE_CODE (TREE_OPERAND (op1, 1));
13080 enum tree_code opcode = NOP_EXPR;
13081 if (code == OMP_ATOMIC_READ)
13083 v = RECUR (TREE_OPERAND (op1, 0));
13084 lhs = RECUR (TREE_OPERAND (TREE_OPERAND (op1, 1), 0));
13086 else if (code == OMP_ATOMIC_CAPTURE_OLD
13087 || code == OMP_ATOMIC_CAPTURE_NEW)
13089 tree op11 = TREE_OPERAND (TREE_OPERAND (op1, 1), 1);
13090 v = RECUR (TREE_OPERAND (op1, 0));
13091 lhs1 = RECUR (TREE_OPERAND (TREE_OPERAND (op1, 1), 0));
13092 if (TREE_CODE (op11) == COMPOUND_EXPR)
13094 rhs1 = RECUR (TREE_OPERAND (op11, 0));
13095 op11 = TREE_OPERAND (op11, 1);
13097 lhs = RECUR (TREE_OPERAND (op11, 0));
13098 rhs = RECUR (TREE_OPERAND (op11, 1));
13099 opcode = TREE_CODE (op11);
13104 lhs = RECUR (TREE_OPERAND (op1, 0));
13105 rhs = RECUR (TREE_OPERAND (op1, 1));
13107 finish_omp_atomic (code, opcode, lhs, rhs, v, lhs1, rhs1);
13111 case TRANSACTION_EXPR:
13114 flags |= (TRANSACTION_EXPR_OUTER (t) ? TM_STMT_ATTR_OUTER : 0);
13115 flags |= (TRANSACTION_EXPR_RELAXED (t) ? TM_STMT_ATTR_RELAXED : 0);
13117 if (TRANSACTION_EXPR_IS_STMT (t))
13119 stmt = begin_transaction_stmt (input_location, NULL, flags);
13120 RECUR (TRANSACTION_EXPR_BODY (t));
13121 finish_transaction_stmt (stmt, NULL, flags);
13125 stmt = build_transaction_expr (EXPR_LOCATION (t),
13126 RECUR (TRANSACTION_EXPR_BODY (t)),
13133 case EXPR_PACK_EXPANSION:
13134 error ("invalid use of pack expansion expression");
13135 return error_mark_node;
13137 case NONTYPE_ARGUMENT_PACK:
13138 error ("use %<...%> to expand argument pack");
13139 return error_mark_node;
13142 gcc_assert (!STATEMENT_CODE_P (TREE_CODE (t)));
13144 return tsubst_copy_and_build (t, args, complain, in_decl,
13145 /*function_p=*/false,
13146 integral_constant_expression_p);
13153 /* T is a postfix-expression that is not being used in a function
13154 call. Return the substituted version of T. */
13157 tsubst_non_call_postfix_expression (tree t, tree args,
13158 tsubst_flags_t complain,
13161 if (TREE_CODE (t) == SCOPE_REF)
13162 t = tsubst_qualified_id (t, args, complain, in_decl,
13163 /*done=*/false, /*address_p=*/false);
13165 t = tsubst_copy_and_build (t, args, complain, in_decl,
13166 /*function_p=*/false,
13167 /*integral_constant_expression_p=*/false);
13172 /* Like tsubst but deals with expressions and performs semantic
13173 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
13176 tsubst_copy_and_build (tree t,
13178 tsubst_flags_t complain,
13181 bool integral_constant_expression_p)
13183 #define RECUR(NODE) \
13184 tsubst_copy_and_build (NODE, args, complain, in_decl, \
13185 /*function_p=*/false, \
13186 integral_constant_expression_p)
13190 if (t == NULL_TREE || t == error_mark_node)
13193 switch (TREE_CODE (t))
13197 /* Fall through. */
13198 case IDENTIFIER_NODE:
13202 bool non_integral_constant_expression_p;
13203 const char *error_msg;
13205 if (IDENTIFIER_TYPENAME_P (t))
13207 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
13208 t = mangle_conv_op_name_for_type (new_type);
13211 /* Look up the name. */
13212 decl = lookup_name (t);
13214 /* By convention, expressions use ERROR_MARK_NODE to indicate
13215 failure, not NULL_TREE. */
13216 if (decl == NULL_TREE)
13217 decl = error_mark_node;
13219 decl = finish_id_expression (t, decl, NULL_TREE,
13221 integral_constant_expression_p,
13222 /*allow_non_integral_constant_expression_p=*/false,
13223 &non_integral_constant_expression_p,
13224 /*template_p=*/false,
13226 /*address_p=*/false,
13227 /*template_arg_p=*/false,
13232 if (!function_p && TREE_CODE (decl) == IDENTIFIER_NODE)
13234 if (complain & tf_error)
13235 unqualified_name_lookup_error (decl);
13236 decl = error_mark_node;
13241 case TEMPLATE_ID_EXPR:
13244 tree templ = RECUR (TREE_OPERAND (t, 0));
13245 tree targs = TREE_OPERAND (t, 1);
13248 targs = tsubst_template_args (targs, args, complain, in_decl);
13250 if (TREE_CODE (templ) == COMPONENT_REF)
13252 object = TREE_OPERAND (templ, 0);
13253 templ = TREE_OPERAND (templ, 1);
13256 object = NULL_TREE;
13257 templ = lookup_template_function (templ, targs);
13260 return build3 (COMPONENT_REF, TREE_TYPE (templ),
13261 object, templ, NULL_TREE);
13263 return baselink_for_fns (templ);
13268 tree r = RECUR (TREE_OPERAND (t, 0));
13270 if (REFERENCE_REF_P (t))
13272 /* A type conversion to reference type will be enclosed in
13273 such an indirect ref, but the substitution of the cast
13274 will have also added such an indirect ref. */
13275 if (TREE_CODE (TREE_TYPE (r)) == REFERENCE_TYPE)
13276 r = convert_from_reference (r);
13279 r = build_x_indirect_ref (r, RO_UNARY_STAR, complain);
13285 (tsubst (TREE_TYPE (t), args, complain, in_decl),
13286 RECUR (TREE_OPERAND (t, 0)));
13288 case IMPLICIT_CONV_EXPR:
13290 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
13291 tree expr = RECUR (TREE_OPERAND (t, 0));
13292 int flags = LOOKUP_IMPLICIT;
13293 if (IMPLICIT_CONV_EXPR_DIRECT_INIT (t))
13294 flags = LOOKUP_NORMAL;
13295 return perform_implicit_conversion_flags (type, expr, complain,
13302 tsubst (TREE_TYPE (t), args, complain, in_decl),
13303 RECUR (TREE_OPERAND (t, 0)));
13306 case REINTERPRET_CAST_EXPR:
13307 case CONST_CAST_EXPR:
13308 case DYNAMIC_CAST_EXPR:
13309 case STATIC_CAST_EXPR:
13314 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
13315 if (integral_constant_expression_p
13316 && !cast_valid_in_integral_constant_expression_p (type))
13318 if (complain & tf_error)
13319 error ("a cast to a type other than an integral or "
13320 "enumeration type cannot appear in a constant-expression");
13321 return error_mark_node;
13324 op = RECUR (TREE_OPERAND (t, 0));
13326 switch (TREE_CODE (t))
13329 return build_functional_cast (type, op, complain);
13330 case REINTERPRET_CAST_EXPR:
13331 return build_reinterpret_cast (type, op, complain);
13332 case CONST_CAST_EXPR:
13333 return build_const_cast (type, op, complain);
13334 case DYNAMIC_CAST_EXPR:
13335 return build_dynamic_cast (type, op, complain);
13336 case STATIC_CAST_EXPR:
13337 return build_static_cast (type, op, complain);
13339 gcc_unreachable ();
13343 case POSTDECREMENT_EXPR:
13344 case POSTINCREMENT_EXPR:
13345 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
13346 args, complain, in_decl);
13347 return build_x_unary_op (TREE_CODE (t), op1, complain);
13349 case PREDECREMENT_EXPR:
13350 case PREINCREMENT_EXPR:
13354 case TRUTH_NOT_EXPR:
13355 case UNARY_PLUS_EXPR: /* Unary + */
13356 case REALPART_EXPR:
13357 case IMAGPART_EXPR:
13358 return build_x_unary_op (TREE_CODE (t), RECUR (TREE_OPERAND (t, 0)),
13362 op1 = TREE_OPERAND (t, 0);
13363 if (TREE_CODE (op1) == LABEL_DECL)
13364 return finish_label_address_expr (DECL_NAME (op1),
13365 EXPR_LOCATION (op1));
13366 if (TREE_CODE (op1) == SCOPE_REF)
13367 op1 = tsubst_qualified_id (op1, args, complain, in_decl,
13368 /*done=*/true, /*address_p=*/true);
13370 op1 = tsubst_non_call_postfix_expression (op1, args, complain,
13372 return build_x_unary_op (ADDR_EXPR, op1, complain);
13377 case TRUNC_DIV_EXPR:
13378 case CEIL_DIV_EXPR:
13379 case FLOOR_DIV_EXPR:
13380 case ROUND_DIV_EXPR:
13381 case EXACT_DIV_EXPR:
13385 case TRUNC_MOD_EXPR:
13386 case FLOOR_MOD_EXPR:
13387 case TRUTH_ANDIF_EXPR:
13388 case TRUTH_ORIF_EXPR:
13389 case TRUTH_AND_EXPR:
13390 case TRUTH_OR_EXPR:
13405 return build_x_binary_op
13407 RECUR (TREE_OPERAND (t, 0)),
13408 (TREE_NO_WARNING (TREE_OPERAND (t, 0))
13410 : TREE_CODE (TREE_OPERAND (t, 0))),
13411 RECUR (TREE_OPERAND (t, 1)),
13412 (TREE_NO_WARNING (TREE_OPERAND (t, 1))
13414 : TREE_CODE (TREE_OPERAND (t, 1))),
13419 return tsubst_qualified_id (t, args, complain, in_decl, /*done=*/true,
13420 /*address_p=*/false);
13422 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
13423 args, complain, in_decl);
13424 return build_x_array_ref (op1, RECUR (TREE_OPERAND (t, 1)), complain);
13427 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
13428 return tsubst_copy (t, args, complain, in_decl);
13432 op1 = TREE_OPERAND (t, 0);
13435 /* When there are no ARGS, we are trying to evaluate a
13436 non-dependent expression from the parser. Trying to do
13437 the substitutions may not work. */
13439 op1 = TREE_TYPE (op1);
13443 ++cp_unevaluated_operand;
13444 ++c_inhibit_evaluation_warnings;
13445 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
13446 /*function_p=*/false,
13447 /*integral_constant_expression_p=*/false);
13448 --cp_unevaluated_operand;
13449 --c_inhibit_evaluation_warnings;
13452 return cxx_sizeof_or_alignof_type (op1, TREE_CODE (t),
13453 complain & tf_error);
13455 return cxx_sizeof_or_alignof_expr (op1, TREE_CODE (t),
13456 complain & tf_error);
13458 case AT_ENCODE_EXPR:
13460 op1 = TREE_OPERAND (t, 0);
13461 ++cp_unevaluated_operand;
13462 ++c_inhibit_evaluation_warnings;
13463 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
13464 /*function_p=*/false,
13465 /*integral_constant_expression_p=*/false);
13466 --cp_unevaluated_operand;
13467 --c_inhibit_evaluation_warnings;
13468 return objc_build_encode_expr (op1);
13471 case NOEXCEPT_EXPR:
13472 op1 = TREE_OPERAND (t, 0);
13473 ++cp_unevaluated_operand;
13474 ++c_inhibit_evaluation_warnings;
13475 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
13476 /*function_p=*/false,
13477 /*integral_constant_expression_p=*/false);
13478 --cp_unevaluated_operand;
13479 --c_inhibit_evaluation_warnings;
13480 return finish_noexcept_expr (op1, complain);
13484 tree r = build_x_modify_expr
13485 (RECUR (TREE_OPERAND (t, 0)),
13486 TREE_CODE (TREE_OPERAND (t, 1)),
13487 RECUR (TREE_OPERAND (t, 2)),
13489 /* TREE_NO_WARNING must be set if either the expression was
13490 parenthesized or it uses an operator such as >>= rather
13491 than plain assignment. In the former case, it was already
13492 set and must be copied. In the latter case,
13493 build_x_modify_expr sets it and it must not be reset
13495 if (TREE_NO_WARNING (t))
13496 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
13501 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
13502 args, complain, in_decl);
13503 /* Remember that there was a reference to this entity. */
13506 return build_x_arrow (op1);
13510 tree placement = RECUR (TREE_OPERAND (t, 0));
13511 tree init = RECUR (TREE_OPERAND (t, 3));
13512 VEC(tree,gc) *placement_vec;
13513 VEC(tree,gc) *init_vec;
13516 if (placement == NULL_TREE)
13517 placement_vec = NULL;
13520 placement_vec = make_tree_vector ();
13521 for (; placement != NULL_TREE; placement = TREE_CHAIN (placement))
13522 VEC_safe_push (tree, gc, placement_vec, TREE_VALUE (placement));
13525 /* If there was an initializer in the original tree, but it
13526 instantiated to an empty list, then we should pass a
13527 non-NULL empty vector to tell build_new that it was an
13528 empty initializer() rather than no initializer. This can
13529 only happen when the initializer is a pack expansion whose
13530 parameter packs are of length zero. */
13531 if (init == NULL_TREE && TREE_OPERAND (t, 3) == NULL_TREE)
13535 init_vec = make_tree_vector ();
13536 if (init == void_zero_node)
13537 gcc_assert (init_vec != NULL);
13540 for (; init != NULL_TREE; init = TREE_CHAIN (init))
13541 VEC_safe_push (tree, gc, init_vec, TREE_VALUE (init));
13545 ret = build_new (&placement_vec,
13546 tsubst (TREE_OPERAND (t, 1), args, complain, in_decl),
13547 RECUR (TREE_OPERAND (t, 2)),
13549 NEW_EXPR_USE_GLOBAL (t),
13552 if (placement_vec != NULL)
13553 release_tree_vector (placement_vec);
13554 if (init_vec != NULL)
13555 release_tree_vector (init_vec);
13561 return delete_sanity
13562 (RECUR (TREE_OPERAND (t, 0)),
13563 RECUR (TREE_OPERAND (t, 1)),
13564 DELETE_EXPR_USE_VEC (t),
13565 DELETE_EXPR_USE_GLOBAL (t),
13568 case COMPOUND_EXPR:
13569 return build_x_compound_expr (RECUR (TREE_OPERAND (t, 0)),
13570 RECUR (TREE_OPERAND (t, 1)),
13576 VEC(tree,gc) *call_args;
13577 unsigned int nargs, i;
13582 function = CALL_EXPR_FN (t);
13583 /* When we parsed the expression, we determined whether or
13584 not Koenig lookup should be performed. */
13585 koenig_p = KOENIG_LOOKUP_P (t);
13586 if (TREE_CODE (function) == SCOPE_REF)
13588 qualified_p = true;
13589 function = tsubst_qualified_id (function, args, complain, in_decl,
13591 /*address_p=*/false);
13593 else if (koenig_p && TREE_CODE (function) == IDENTIFIER_NODE)
13595 /* Do nothing; calling tsubst_copy_and_build on an identifier
13596 would incorrectly perform unqualified lookup again.
13598 Note that we can also have an IDENTIFIER_NODE if the earlier
13599 unqualified lookup found a member function; in that case
13600 koenig_p will be false and we do want to do the lookup
13601 again to find the instantiated member function.
13603 FIXME but doing that causes c++/15272, so we need to stop
13604 using IDENTIFIER_NODE in that situation. */
13605 qualified_p = false;
13609 if (TREE_CODE (function) == COMPONENT_REF)
13611 tree op = TREE_OPERAND (function, 1);
13613 qualified_p = (TREE_CODE (op) == SCOPE_REF
13614 || (BASELINK_P (op)
13615 && BASELINK_QUALIFIED_P (op)));
13618 qualified_p = false;
13620 function = tsubst_copy_and_build (function, args, complain,
13623 integral_constant_expression_p);
13625 if (BASELINK_P (function))
13626 qualified_p = true;
13629 nargs = call_expr_nargs (t);
13630 call_args = make_tree_vector ();
13631 for (i = 0; i < nargs; ++i)
13633 tree arg = CALL_EXPR_ARG (t, i);
13635 if (!PACK_EXPANSION_P (arg))
13636 VEC_safe_push (tree, gc, call_args,
13637 RECUR (CALL_EXPR_ARG (t, i)));
13640 /* Expand the pack expansion and push each entry onto
13642 arg = tsubst_pack_expansion (arg, args, complain, in_decl);
13643 if (TREE_CODE (arg) == TREE_VEC)
13645 unsigned int len, j;
13647 len = TREE_VEC_LENGTH (arg);
13648 for (j = 0; j < len; ++j)
13650 tree value = TREE_VEC_ELT (arg, j);
13651 if (value != NULL_TREE)
13652 value = convert_from_reference (value);
13653 VEC_safe_push (tree, gc, call_args, value);
13658 /* A partial substitution. Add one entry. */
13659 VEC_safe_push (tree, gc, call_args, arg);
13664 /* We do not perform argument-dependent lookup if normal
13665 lookup finds a non-function, in accordance with the
13666 expected resolution of DR 218. */
13668 && ((is_overloaded_fn (function)
13669 /* If lookup found a member function, the Koenig lookup is
13670 not appropriate, even if an unqualified-name was used
13671 to denote the function. */
13672 && !DECL_FUNCTION_MEMBER_P (get_first_fn (function)))
13673 || TREE_CODE (function) == IDENTIFIER_NODE)
13674 /* Only do this when substitution turns a dependent call
13675 into a non-dependent call. */
13676 && type_dependent_expression_p_push (t)
13677 && !any_type_dependent_arguments_p (call_args))
13678 function = perform_koenig_lookup (function, call_args, false,
13681 if (TREE_CODE (function) == IDENTIFIER_NODE
13682 && !any_type_dependent_arguments_p (call_args))
13684 if (koenig_p && (complain & tf_warning_or_error))
13686 /* For backwards compatibility and good diagnostics, try
13687 the unqualified lookup again if we aren't in SFINAE
13689 tree unq = (tsubst_copy_and_build
13690 (function, args, complain, in_decl, true,
13691 integral_constant_expression_p));
13692 if (unq == error_mark_node)
13693 return error_mark_node;
13695 if (unq != function)
13698 if (TREE_CODE (fn) == INDIRECT_REF)
13699 fn = TREE_OPERAND (fn, 0);
13700 if (TREE_CODE (fn) == COMPONENT_REF)
13701 fn = TREE_OPERAND (fn, 1);
13702 if (is_overloaded_fn (fn))
13703 fn = get_first_fn (fn);
13704 permerror (EXPR_LOC_OR_HERE (t),
13705 "%qD was not declared in this scope, "
13706 "and no declarations were found by "
13707 "argument-dependent lookup at the point "
13708 "of instantiation", function);
13710 /* Can't say anything more. */;
13711 else if (DECL_CLASS_SCOPE_P (fn))
13713 inform (EXPR_LOC_OR_HERE (t),
13714 "declarations in dependent base %qT are "
13715 "not found by unqualified lookup",
13716 DECL_CLASS_CONTEXT (fn));
13717 if (current_class_ptr)
13718 inform (EXPR_LOC_OR_HERE (t),
13719 "use %<this->%D%> instead", function);
13721 inform (EXPR_LOC_OR_HERE (t),
13722 "use %<%T::%D%> instead",
13723 current_class_name, function);
13726 inform (0, "%q+D declared here, later in the "
13727 "translation unit", fn);
13731 if (TREE_CODE (function) == IDENTIFIER_NODE)
13733 unqualified_name_lookup_error (function);
13734 release_tree_vector (call_args);
13735 return error_mark_node;
13739 /* Remember that there was a reference to this entity. */
13740 if (DECL_P (function))
13741 mark_used (function);
13743 if (TREE_CODE (function) == OFFSET_REF)
13744 ret = build_offset_ref_call_from_tree (function, &call_args);
13745 else if (TREE_CODE (function) == COMPONENT_REF)
13747 tree instance = TREE_OPERAND (function, 0);
13748 tree fn = TREE_OPERAND (function, 1);
13750 if (processing_template_decl
13751 && (type_dependent_expression_p (instance)
13752 || (!BASELINK_P (fn)
13753 && TREE_CODE (fn) != FIELD_DECL)
13754 || type_dependent_expression_p (fn)
13755 || any_type_dependent_arguments_p (call_args)))
13756 ret = build_nt_call_vec (function, call_args);
13757 else if (!BASELINK_P (fn))
13758 ret = finish_call_expr (function, &call_args,
13759 /*disallow_virtual=*/false,
13760 /*koenig_p=*/false,
13763 ret = (build_new_method_call
13765 &call_args, NULL_TREE,
13766 qualified_p ? LOOKUP_NONVIRTUAL : LOOKUP_NORMAL,
13771 ret = finish_call_expr (function, &call_args,
13772 /*disallow_virtual=*/qualified_p,
13776 release_tree_vector (call_args);
13782 return build_x_conditional_expr
13783 (RECUR (TREE_OPERAND (t, 0)),
13784 RECUR (TREE_OPERAND (t, 1)),
13785 RECUR (TREE_OPERAND (t, 2)),
13788 case PSEUDO_DTOR_EXPR:
13789 return finish_pseudo_destructor_expr
13790 (RECUR (TREE_OPERAND (t, 0)),
13791 RECUR (TREE_OPERAND (t, 1)),
13792 tsubst (TREE_OPERAND (t, 2), args, complain, in_decl));
13796 tree purpose, value, chain;
13798 if (t == void_list_node)
13801 if ((TREE_PURPOSE (t) && PACK_EXPANSION_P (TREE_PURPOSE (t)))
13802 || (TREE_VALUE (t) && PACK_EXPANSION_P (TREE_VALUE (t))))
13804 /* We have pack expansions, so expand those and
13805 create a new list out of it. */
13806 tree purposevec = NULL_TREE;
13807 tree valuevec = NULL_TREE;
13811 /* Expand the argument expressions. */
13812 if (TREE_PURPOSE (t))
13813 purposevec = tsubst_pack_expansion (TREE_PURPOSE (t), args,
13814 complain, in_decl);
13815 if (TREE_VALUE (t))
13816 valuevec = tsubst_pack_expansion (TREE_VALUE (t), args,
13817 complain, in_decl);
13819 /* Build the rest of the list. */
13820 chain = TREE_CHAIN (t);
13821 if (chain && chain != void_type_node)
13822 chain = RECUR (chain);
13824 /* Determine the number of arguments. */
13825 if (purposevec && TREE_CODE (purposevec) == TREE_VEC)
13827 len = TREE_VEC_LENGTH (purposevec);
13828 gcc_assert (!valuevec || len == TREE_VEC_LENGTH (valuevec));
13830 else if (TREE_CODE (valuevec) == TREE_VEC)
13831 len = TREE_VEC_LENGTH (valuevec);
13834 /* Since we only performed a partial substitution into
13835 the argument pack, we only return a single list
13837 if (purposevec == TREE_PURPOSE (t)
13838 && valuevec == TREE_VALUE (t)
13839 && chain == TREE_CHAIN (t))
13842 return tree_cons (purposevec, valuevec, chain);
13845 /* Convert the argument vectors into a TREE_LIST */
13849 /* Grab the Ith values. */
13851 purpose = purposevec ? TREE_VEC_ELT (purposevec, i)
13854 = valuevec ? convert_from_reference (TREE_VEC_ELT (valuevec, i))
13857 /* Build the list (backwards). */
13858 chain = tree_cons (purpose, value, chain);
13864 purpose = TREE_PURPOSE (t);
13866 purpose = RECUR (purpose);
13867 value = TREE_VALUE (t);
13869 value = RECUR (value);
13870 chain = TREE_CHAIN (t);
13871 if (chain && chain != void_type_node)
13872 chain = RECUR (chain);
13873 if (purpose == TREE_PURPOSE (t)
13874 && value == TREE_VALUE (t)
13875 && chain == TREE_CHAIN (t))
13877 return tree_cons (purpose, value, chain);
13880 case COMPONENT_REF:
13886 object = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
13887 args, complain, in_decl);
13888 /* Remember that there was a reference to this entity. */
13889 if (DECL_P (object))
13890 mark_used (object);
13891 object_type = TREE_TYPE (object);
13893 member = TREE_OPERAND (t, 1);
13894 if (BASELINK_P (member))
13895 member = tsubst_baselink (member,
13896 non_reference (TREE_TYPE (object)),
13897 args, complain, in_decl);
13899 member = tsubst_copy (member, args, complain, in_decl);
13900 if (member == error_mark_node)
13901 return error_mark_node;
13903 if (type_dependent_expression_p (object))
13904 /* We can't do much here. */;
13905 else if (!CLASS_TYPE_P (object_type))
13907 if (SCALAR_TYPE_P (object_type))
13909 tree s = NULL_TREE;
13910 tree dtor = member;
13912 if (TREE_CODE (dtor) == SCOPE_REF)
13914 s = TREE_OPERAND (dtor, 0);
13915 dtor = TREE_OPERAND (dtor, 1);
13917 if (TREE_CODE (dtor) == BIT_NOT_EXPR)
13919 dtor = TREE_OPERAND (dtor, 0);
13921 return finish_pseudo_destructor_expr (object, s, dtor);
13925 else if (TREE_CODE (member) == SCOPE_REF
13926 && TREE_CODE (TREE_OPERAND (member, 1)) == TEMPLATE_ID_EXPR)
13928 /* Lookup the template functions now that we know what the
13930 tree scope = TREE_OPERAND (member, 0);
13931 tree tmpl = TREE_OPERAND (TREE_OPERAND (member, 1), 0);
13932 tree args = TREE_OPERAND (TREE_OPERAND (member, 1), 1);
13933 member = lookup_qualified_name (scope, tmpl,
13934 /*is_type_p=*/false,
13935 /*complain=*/false);
13936 if (BASELINK_P (member))
13938 BASELINK_FUNCTIONS (member)
13939 = build_nt (TEMPLATE_ID_EXPR, BASELINK_FUNCTIONS (member),
13941 member = (adjust_result_of_qualified_name_lookup
13942 (member, BINFO_TYPE (BASELINK_BINFO (member)),
13947 qualified_name_lookup_error (scope, tmpl, member,
13949 return error_mark_node;
13952 else if (TREE_CODE (member) == SCOPE_REF
13953 && !CLASS_TYPE_P (TREE_OPERAND (member, 0))
13954 && TREE_CODE (TREE_OPERAND (member, 0)) != NAMESPACE_DECL)
13956 if (complain & tf_error)
13958 if (TYPE_P (TREE_OPERAND (member, 0)))
13959 error ("%qT is not a class or namespace",
13960 TREE_OPERAND (member, 0));
13962 error ("%qD is not a class or namespace",
13963 TREE_OPERAND (member, 0));
13965 return error_mark_node;
13967 else if (TREE_CODE (member) == FIELD_DECL)
13968 return finish_non_static_data_member (member, object, NULL_TREE);
13970 return finish_class_member_access_expr (object, member,
13971 /*template_p=*/false,
13977 (RECUR (TREE_OPERAND (t, 0)));
13981 VEC(constructor_elt,gc) *n;
13982 constructor_elt *ce;
13983 unsigned HOST_WIDE_INT idx;
13984 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
13985 bool process_index_p;
13987 bool need_copy_p = false;
13990 if (type == error_mark_node)
13991 return error_mark_node;
13993 /* digest_init will do the wrong thing if we let it. */
13994 if (type && TYPE_PTRMEMFUNC_P (type))
13997 /* We do not want to process the index of aggregate
13998 initializers as they are identifier nodes which will be
13999 looked up by digest_init. */
14000 process_index_p = !(type && MAYBE_CLASS_TYPE_P (type));
14002 n = VEC_copy (constructor_elt, gc, CONSTRUCTOR_ELTS (t));
14003 newlen = VEC_length (constructor_elt, n);
14004 FOR_EACH_VEC_ELT (constructor_elt, n, idx, ce)
14006 if (ce->index && process_index_p)
14007 ce->index = RECUR (ce->index);
14009 if (PACK_EXPANSION_P (ce->value))
14011 /* Substitute into the pack expansion. */
14012 ce->value = tsubst_pack_expansion (ce->value, args, complain,
14015 if (ce->value == error_mark_node
14016 || PACK_EXPANSION_P (ce->value))
14018 else if (TREE_VEC_LENGTH (ce->value) == 1)
14019 /* Just move the argument into place. */
14020 ce->value = TREE_VEC_ELT (ce->value, 0);
14023 /* Update the length of the final CONSTRUCTOR
14024 arguments vector, and note that we will need to
14026 newlen = newlen + TREE_VEC_LENGTH (ce->value) - 1;
14027 need_copy_p = true;
14031 ce->value = RECUR (ce->value);
14036 VEC(constructor_elt,gc) *old_n = n;
14038 n = VEC_alloc (constructor_elt, gc, newlen);
14039 FOR_EACH_VEC_ELT (constructor_elt, old_n, idx, ce)
14041 if (TREE_CODE (ce->value) == TREE_VEC)
14043 int i, len = TREE_VEC_LENGTH (ce->value);
14044 for (i = 0; i < len; ++i)
14045 CONSTRUCTOR_APPEND_ELT (n, 0,
14046 TREE_VEC_ELT (ce->value, i));
14049 CONSTRUCTOR_APPEND_ELT (n, 0, ce->value);
14053 r = build_constructor (init_list_type_node, n);
14054 CONSTRUCTOR_IS_DIRECT_INIT (r) = CONSTRUCTOR_IS_DIRECT_INIT (t);
14056 if (TREE_HAS_CONSTRUCTOR (t))
14057 return finish_compound_literal (type, r, complain);
14059 TREE_TYPE (r) = type;
14065 tree operand_0 = TREE_OPERAND (t, 0);
14066 if (TYPE_P (operand_0))
14068 operand_0 = tsubst (operand_0, args, complain, in_decl);
14069 return get_typeid (operand_0);
14073 operand_0 = RECUR (operand_0);
14074 return build_typeid (operand_0);
14085 tree r = tsubst_copy (t, args, complain, in_decl);
14087 if (TREE_CODE (TREE_TYPE (t)) != REFERENCE_TYPE)
14088 /* If the original type was a reference, we'll be wrapped in
14089 the appropriate INDIRECT_REF. */
14090 r = convert_from_reference (r);
14095 return build_x_va_arg (RECUR (TREE_OPERAND (t, 0)),
14096 tsubst (TREE_TYPE (t), args, complain, in_decl));
14098 case OFFSETOF_EXPR:
14099 return finish_offsetof (RECUR (TREE_OPERAND (t, 0)));
14103 tree type1 = tsubst_copy (TRAIT_EXPR_TYPE1 (t), args,
14104 complain, in_decl);
14106 tree type2 = TRAIT_EXPR_TYPE2 (t);
14108 type2 = tsubst_copy (type2, args, complain, in_decl);
14110 return finish_trait_expr (TRAIT_EXPR_KIND (t), type1, type2);
14115 tree old_stmt_expr = cur_stmt_expr;
14116 tree stmt_expr = begin_stmt_expr ();
14118 cur_stmt_expr = stmt_expr;
14119 tsubst_expr (STMT_EXPR_STMT (t), args, complain, in_decl,
14120 integral_constant_expression_p);
14121 stmt_expr = finish_stmt_expr (stmt_expr, false);
14122 cur_stmt_expr = old_stmt_expr;
14124 /* If the resulting list of expression statement is empty,
14125 fold it further into void_zero_node. */
14126 if (empty_expr_stmt_p (stmt_expr))
14127 stmt_expr = void_zero_node;
14133 t = tsubst_copy (t, args, complain, in_decl);
14134 /* As in finish_id_expression, we resolve enumeration constants
14135 to their underlying values. */
14136 if (TREE_CODE (t) == CONST_DECL && !processing_template_decl)
14138 used_types_insert (TREE_TYPE (t));
14139 return DECL_INITIAL (t);
14145 tree r = build_lambda_expr ();
14147 tree type = tsubst (LAMBDA_EXPR_CLOSURE (t), args, complain, NULL_TREE);
14148 LAMBDA_EXPR_CLOSURE (r) = type;
14149 CLASSTYPE_LAMBDA_EXPR (type) = r;
14151 LAMBDA_EXPR_LOCATION (r)
14152 = LAMBDA_EXPR_LOCATION (t);
14153 LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (r)
14154 = LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (t);
14155 LAMBDA_EXPR_MUTABLE_P (r) = LAMBDA_EXPR_MUTABLE_P (t);
14156 LAMBDA_EXPR_DISCRIMINATOR (r)
14157 = (LAMBDA_EXPR_DISCRIMINATOR (t));
14158 LAMBDA_EXPR_EXTRA_SCOPE (r)
14159 = RECUR (LAMBDA_EXPR_EXTRA_SCOPE (t));
14160 if (LAMBDA_EXPR_RETURN_TYPE (t) == dependent_lambda_return_type_node)
14162 LAMBDA_EXPR_RETURN_TYPE (r) = dependent_lambda_return_type_node;
14163 LAMBDA_EXPR_DEDUCE_RETURN_TYPE_P (r) = true;
14166 LAMBDA_EXPR_RETURN_TYPE (r)
14167 = tsubst (LAMBDA_EXPR_RETURN_TYPE (t), args, complain, in_decl);
14169 gcc_assert (LAMBDA_EXPR_THIS_CAPTURE (t) == NULL_TREE
14170 && LAMBDA_EXPR_PENDING_PROXIES (t) == NULL);
14172 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
14173 determine_visibility (TYPE_NAME (type));
14174 /* Now that we know visibility, instantiate the type so we have a
14175 declaration of the op() for later calls to lambda_function. */
14176 complete_type (type);
14178 /* The capture list refers to closure members, so this needs to
14179 wait until after we finish instantiating the type. */
14180 LAMBDA_EXPR_CAPTURE_LIST (r)
14181 = RECUR (LAMBDA_EXPR_CAPTURE_LIST (t));
14183 return build_lambda_object (r);
14187 /* We can get here for a constant initializer of non-dependent type.
14188 FIXME stop folding in cp_parser_initializer_clause. */
14189 gcc_assert (TREE_CONSTANT (t));
14191 tree r = get_target_expr (RECUR (TARGET_EXPR_INITIAL (t)));
14192 TREE_CONSTANT (r) = true;
14197 /* Handle Objective-C++ constructs, if appropriate. */
14200 = objcp_tsubst_copy_and_build (t, args, complain,
14201 in_decl, /*function_p=*/false);
14205 return tsubst_copy (t, args, complain, in_decl);
14211 /* Verify that the instantiated ARGS are valid. For type arguments,
14212 make sure that the type's linkage is ok. For non-type arguments,
14213 make sure they are constants if they are integral or enumerations.
14214 Emit an error under control of COMPLAIN, and return TRUE on error. */
14217 check_instantiated_arg (tree tmpl, tree t, tsubst_flags_t complain)
14219 if (ARGUMENT_PACK_P (t))
14221 tree vec = ARGUMENT_PACK_ARGS (t);
14222 int len = TREE_VEC_LENGTH (vec);
14223 bool result = false;
14226 for (i = 0; i < len; ++i)
14227 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (vec, i), complain))
14231 else if (TYPE_P (t))
14233 /* [basic.link]: A name with no linkage (notably, the name
14234 of a class or enumeration declared in a local scope)
14235 shall not be used to declare an entity with linkage.
14236 This implies that names with no linkage cannot be used as
14239 DR 757 relaxes this restriction for C++0x. */
14240 tree nt = (cxx_dialect > cxx98 ? NULL_TREE
14241 : no_linkage_check (t, /*relaxed_p=*/false));
14245 /* DR 488 makes use of a type with no linkage cause
14246 type deduction to fail. */
14247 if (complain & tf_error)
14249 if (TYPE_ANONYMOUS_P (nt))
14250 error ("%qT is/uses anonymous type", t);
14252 error ("template argument for %qD uses local type %qT",
14257 /* In order to avoid all sorts of complications, we do not
14258 allow variably-modified types as template arguments. */
14259 else if (variably_modified_type_p (t, NULL_TREE))
14261 if (complain & tf_error)
14262 error ("%qT is a variably modified type", t);
14266 /* A non-type argument of integral or enumerated type must be a
14268 else if (TREE_TYPE (t)
14269 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t))
14270 && !TREE_CONSTANT (t))
14272 if (complain & tf_error)
14273 error ("integral expression %qE is not constant", t);
14280 check_instantiated_args (tree tmpl, tree args, tsubst_flags_t complain)
14282 int ix, len = DECL_NTPARMS (tmpl);
14283 bool result = false;
14285 for (ix = 0; ix != len; ix++)
14287 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (args, ix), complain))
14290 if (result && (complain & tf_error))
14291 error (" trying to instantiate %qD", tmpl);
14295 /* In C++0x, it's possible to have a function template whose type depends
14296 on itself recursively. This is most obvious with decltype, but can also
14297 occur with enumeration scope (c++/48969). So we need to catch infinite
14298 recursion and reject the substitution at deduction time; this function
14299 will return error_mark_node for any repeated substitution.
14301 This also catches excessive recursion such as when f<N> depends on
14302 f<N-1> across all integers, and returns error_mark_node for all the
14303 substitutions back up to the initial one.
14305 This is, of course, not reentrant. */
14308 deduction_tsubst_fntype (tree fn, tree targs, tsubst_flags_t complain)
14310 static bool excessive_deduction_depth;
14311 static int deduction_depth;
14312 struct pending_template *old_last_pend = last_pending_template;
14313 struct tinst_level *old_error_tinst = last_error_tinst_level;
14315 tree fntype = TREE_TYPE (fn);
14319 if (excessive_deduction_depth)
14320 return error_mark_node;
14322 tinst = build_tree_list (fn, targs);
14323 if (!push_tinst_level (tinst))
14325 excessive_deduction_depth = true;
14327 return error_mark_node;
14330 input_location = DECL_SOURCE_LOCATION (fn);
14332 push_deduction_access_scope (fn);
14333 r = tsubst (fntype, targs, complain, NULL_TREE);
14334 pop_deduction_access_scope (fn);
14337 if (excessive_deduction_depth)
14339 r = error_mark_node;
14340 if (deduction_depth == 0)
14341 /* Reset once we're all the way out. */
14342 excessive_deduction_depth = false;
14345 pop_tinst_level ();
14346 /* We can't free this if a pending_template entry or last_error_tinst_level
14347 is pointing at it. */
14348 if (last_pending_template == old_last_pend
14349 && last_error_tinst_level == old_error_tinst)
14354 /* Instantiate the indicated variable or function template TMPL with
14355 the template arguments in TARG_PTR. */
14358 instantiate_template_1 (tree tmpl, tree orig_args, tsubst_flags_t complain)
14360 tree targ_ptr = orig_args;
14364 HOST_WIDE_INT saved_processing_template_decl;
14366 if (tmpl == error_mark_node)
14367 return error_mark_node;
14369 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
14371 /* If this function is a clone, handle it specially. */
14372 if (DECL_CLONED_FUNCTION_P (tmpl))
14377 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
14378 DECL_CLONED_FUNCTION. */
14379 spec = instantiate_template (DECL_ABSTRACT_ORIGIN (tmpl),
14380 targ_ptr, complain);
14381 if (spec == error_mark_node)
14382 return error_mark_node;
14384 /* Look for the clone. */
14385 FOR_EACH_CLONE (clone, spec)
14386 if (DECL_NAME (clone) == DECL_NAME (tmpl))
14388 /* We should always have found the clone by now. */
14389 gcc_unreachable ();
14393 /* Check to see if we already have this specialization. */
14394 gen_tmpl = most_general_template (tmpl);
14395 if (tmpl != gen_tmpl)
14396 /* The TMPL is a partial instantiation. To get a full set of
14397 arguments we must add the arguments used to perform the
14398 partial instantiation. */
14399 targ_ptr = add_outermost_template_args (DECL_TI_ARGS (tmpl),
14402 /* It would be nice to avoid hashing here and then again in tsubst_decl,
14403 but it doesn't seem to be on the hot path. */
14404 spec = retrieve_specialization (gen_tmpl, targ_ptr, 0);
14406 gcc_assert (tmpl == gen_tmpl
14407 || ((fndecl = retrieve_specialization (tmpl, orig_args, 0))
14409 || fndecl == NULL_TREE);
14411 if (spec != NULL_TREE)
14414 if (check_instantiated_args (gen_tmpl, INNERMOST_TEMPLATE_ARGS (targ_ptr),
14416 return error_mark_node;
14418 /* We are building a FUNCTION_DECL, during which the access of its
14419 parameters and return types have to be checked. However this
14420 FUNCTION_DECL which is the desired context for access checking
14421 is not built yet. We solve this chicken-and-egg problem by
14422 deferring all checks until we have the FUNCTION_DECL. */
14423 push_deferring_access_checks (dk_deferred);
14425 /* Although PROCESSING_TEMPLATE_DECL may be true at this point
14426 (because, for example, we have encountered a non-dependent
14427 function call in the body of a template function and must now
14428 determine which of several overloaded functions will be called),
14429 within the instantiation itself we are not processing a
14431 saved_processing_template_decl = processing_template_decl;
14432 processing_template_decl = 0;
14433 /* Substitute template parameters to obtain the specialization. */
14434 fndecl = tsubst (DECL_TEMPLATE_RESULT (gen_tmpl),
14435 targ_ptr, complain, gen_tmpl);
14436 processing_template_decl = saved_processing_template_decl;
14437 if (fndecl == error_mark_node)
14438 return error_mark_node;
14440 /* Now we know the specialization, compute access previously
14442 push_access_scope (fndecl);
14444 /* Some typedefs referenced from within the template code need to be access
14445 checked at template instantiation time, i.e now. These types were
14446 added to the template at parsing time. Let's get those and perfom
14447 the acces checks then. */
14448 perform_typedefs_access_check (DECL_TEMPLATE_RESULT (tmpl), targ_ptr);
14449 perform_deferred_access_checks ();
14450 pop_access_scope (fndecl);
14451 pop_deferring_access_checks ();
14453 /* The DECL_TI_TEMPLATE should always be the immediate parent
14454 template, not the most general template. */
14455 DECL_TI_TEMPLATE (fndecl) = tmpl;
14457 /* If we've just instantiated the main entry point for a function,
14458 instantiate all the alternate entry points as well. We do this
14459 by cloning the instantiation of the main entry point, not by
14460 instantiating the template clones. */
14461 if (DECL_CHAIN (gen_tmpl) && DECL_CLONED_FUNCTION_P (DECL_CHAIN (gen_tmpl)))
14462 clone_function_decl (fndecl, /*update_method_vec_p=*/0);
14467 /* Wrapper for instantiate_template_1. */
14470 instantiate_template (tree tmpl, tree orig_args, tsubst_flags_t complain)
14473 timevar_push (TV_TEMPLATE_INST);
14474 ret = instantiate_template_1 (tmpl, orig_args, complain);
14475 timevar_pop (TV_TEMPLATE_INST);
14479 /* We're going to do deduction substitution on the type of TMPL, a function
14480 template. In C++11 mode, push into that access scope. In C++03 mode,
14481 disable access checking. */
14484 push_deduction_access_scope (tree tmpl)
14486 if (cxx_dialect >= cxx0x)
14488 int ptd = processing_template_decl;
14489 push_access_scope (DECL_TEMPLATE_RESULT (tmpl));
14490 /* Preserve processing_template_decl across push_to_top_level. */
14491 if (ptd && !processing_template_decl)
14492 ++processing_template_decl;
14495 push_deferring_access_checks (dk_no_check);
14498 /* And pop back out. */
14501 pop_deduction_access_scope (tree tmpl)
14503 if (cxx_dialect >= cxx0x)
14504 pop_access_scope (DECL_TEMPLATE_RESULT (tmpl));
14506 pop_deferring_access_checks ();
14509 /* PARM is a template parameter pack for FN. Returns true iff
14510 PARM is used in a deducible way in the argument list of FN. */
14513 pack_deducible_p (tree parm, tree fn)
14515 tree t = FUNCTION_FIRST_USER_PARMTYPE (fn);
14516 for (; t; t = TREE_CHAIN (t))
14518 tree type = TREE_VALUE (t);
14520 if (!PACK_EXPANSION_P (type))
14522 for (packs = PACK_EXPANSION_PARAMETER_PACKS (type);
14523 packs; packs = TREE_CHAIN (packs))
14524 if (TREE_VALUE (packs) == parm)
14526 /* The template parameter pack is used in a function parameter
14527 pack. If this is the end of the parameter list, the
14528 template parameter pack is deducible. */
14529 if (TREE_CHAIN (t) == void_list_node)
14532 /* Otherwise, not. Well, it could be deduced from
14533 a non-pack parameter, but doing so would end up with
14534 a deduction mismatch, so don't bother. */
14538 /* The template parameter pack isn't used in any function parameter
14539 packs, but it might be used deeper, e.g. tuple<Args...>. */
14543 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
14544 NARGS elements of the arguments that are being used when calling
14545 it. TARGS is a vector into which the deduced template arguments
14548 Return zero for success, 2 for an incomplete match that doesn't resolve
14549 all the types, and 1 for complete failure. An error message will be
14550 printed only for an incomplete match.
14552 If FN is a conversion operator, or we are trying to produce a specific
14553 specialization, RETURN_TYPE is the return type desired.
14555 The EXPLICIT_TARGS are explicit template arguments provided via a
14558 The parameter STRICT is one of:
14561 We are deducing arguments for a function call, as in
14562 [temp.deduct.call].
14565 We are deducing arguments for a conversion function, as in
14566 [temp.deduct.conv].
14569 We are deducing arguments when doing an explicit instantiation
14570 as in [temp.explicit], when determining an explicit specialization
14571 as in [temp.expl.spec], or when taking the address of a function
14572 template, as in [temp.deduct.funcaddr]. */
14575 fn_type_unification (tree fn,
14576 tree explicit_targs,
14579 unsigned int nargs,
14581 unification_kind_t strict,
14589 gcc_assert (TREE_CODE (fn) == TEMPLATE_DECL);
14591 fntype = TREE_TYPE (fn);
14592 if (explicit_targs)
14596 The specified template arguments must match the template
14597 parameters in kind (i.e., type, nontype, template), and there
14598 must not be more arguments than there are parameters;
14599 otherwise type deduction fails.
14601 Nontype arguments must match the types of the corresponding
14602 nontype template parameters, or must be convertible to the
14603 types of the corresponding nontype parameters as specified in
14604 _temp.arg.nontype_, otherwise type deduction fails.
14606 All references in the function type of the function template
14607 to the corresponding template parameters are replaced by the
14608 specified template argument values. If a substitution in a
14609 template parameter or in the function type of the function
14610 template results in an invalid type, type deduction fails. */
14611 tree tparms = DECL_INNERMOST_TEMPLATE_PARMS (fn);
14612 int i, len = TREE_VEC_LENGTH (tparms);
14613 tree converted_args;
14614 bool incomplete = false;
14616 if (explicit_targs == error_mark_node)
14617 return unify_invalid (explain_p);
14620 = (coerce_template_parms (tparms, explicit_targs, NULL_TREE,
14622 ? tf_warning_or_error
14624 /*require_all_args=*/false,
14625 /*use_default_args=*/false));
14626 if (converted_args == error_mark_node)
14629 /* Substitute the explicit args into the function type. This is
14630 necessary so that, for instance, explicitly declared function
14631 arguments can match null pointed constants. If we were given
14632 an incomplete set of explicit args, we must not do semantic
14633 processing during substitution as we could create partial
14635 for (i = 0; i < len; i++)
14637 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
14638 bool parameter_pack = false;
14639 tree targ = TREE_VEC_ELT (converted_args, i);
14641 /* Dig out the actual parm. */
14642 if (TREE_CODE (parm) == TYPE_DECL
14643 || TREE_CODE (parm) == TEMPLATE_DECL)
14645 parm = TREE_TYPE (parm);
14646 parameter_pack = TEMPLATE_TYPE_PARAMETER_PACK (parm);
14648 else if (TREE_CODE (parm) == PARM_DECL)
14650 parm = DECL_INITIAL (parm);
14651 parameter_pack = TEMPLATE_PARM_PARAMETER_PACK (parm);
14654 if (!parameter_pack && targ == NULL_TREE)
14655 /* No explicit argument for this template parameter. */
14658 if (parameter_pack && pack_deducible_p (parm, fn))
14660 /* Mark the argument pack as "incomplete". We could
14661 still deduce more arguments during unification.
14662 We remove this mark in type_unification_real. */
14665 ARGUMENT_PACK_INCOMPLETE_P(targ) = 1;
14666 ARGUMENT_PACK_EXPLICIT_ARGS (targ)
14667 = ARGUMENT_PACK_ARGS (targ);
14670 /* We have some incomplete argument packs. */
14675 processing_template_decl += incomplete;
14676 fntype = deduction_tsubst_fntype (fn, converted_args,
14678 ? tf_warning_or_error
14680 processing_template_decl -= incomplete;
14682 if (fntype == error_mark_node)
14685 /* Place the explicitly specified arguments in TARGS. */
14686 for (i = NUM_TMPL_ARGS (converted_args); i--;)
14687 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (converted_args, i);
14690 /* Never do unification on the 'this' parameter. */
14691 parms = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (fntype));
14697 parms = tree_cons (NULL_TREE, TREE_TYPE (fntype), parms);
14698 new_args = XALLOCAVEC (tree, nargs + 1);
14699 new_args[0] = return_type;
14700 memcpy (new_args + 1, args, nargs * sizeof (tree));
14705 /* We allow incomplete unification without an error message here
14706 because the standard doesn't seem to explicitly prohibit it. Our
14707 callers must be ready to deal with unification failures in any
14709 result = type_unification_real (DECL_INNERMOST_TEMPLATE_PARMS (fn),
14710 targs, parms, args, nargs, /*subr=*/0,
14711 strict, flags, explain_p);
14713 /* Now that we have bindings for all of the template arguments,
14714 ensure that the arguments deduced for the template template
14715 parameters have compatible template parameter lists. We cannot
14716 check this property before we have deduced all template
14717 arguments, because the template parameter types of a template
14718 template parameter might depend on prior template parameters
14719 deduced after the template template parameter. The following
14720 ill-formed example illustrates this issue:
14722 template<typename T, template<T> class C> void f(C<5>, T);
14724 template<int N> struct X {};
14727 f(X<5>(), 5l); // error: template argument deduction fails
14730 The template parameter list of 'C' depends on the template type
14731 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
14732 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
14733 time that we deduce 'C'. */
14735 && !template_template_parm_bindings_ok_p
14736 (DECL_INNERMOST_TEMPLATE_PARMS (fn), targs))
14737 return unify_inconsistent_template_template_parameters (explain_p);
14740 /* All is well so far. Now, check:
14744 When all template arguments have been deduced, all uses of
14745 template parameters in nondeduced contexts are replaced with
14746 the corresponding deduced argument values. If the
14747 substitution results in an invalid type, as described above,
14748 type deduction fails. */
14750 tree substed = deduction_tsubst_fntype (fn, targs,
14752 ? tf_warning_or_error
14754 if (substed == error_mark_node)
14757 /* If we're looking for an exact match, check that what we got
14758 is indeed an exact match. It might not be if some template
14759 parameters are used in non-deduced contexts. */
14760 if (strict == DEDUCE_EXACT)
14765 = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (substed));
14767 sarg = tree_cons (NULL_TREE, TREE_TYPE (substed), sarg);
14768 for (i = 0; i < nargs && sarg; ++i, sarg = TREE_CHAIN (sarg))
14769 if (!same_type_p (args[i], TREE_VALUE (sarg)))
14770 return unify_type_mismatch (explain_p, args[i],
14771 TREE_VALUE (sarg));
14778 /* Adjust types before performing type deduction, as described in
14779 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
14780 sections are symmetric. PARM is the type of a function parameter
14781 or the return type of the conversion function. ARG is the type of
14782 the argument passed to the call, or the type of the value
14783 initialized with the result of the conversion function.
14784 ARG_EXPR is the original argument expression, which may be null. */
14787 maybe_adjust_types_for_deduction (unification_kind_t strict,
14801 /* Swap PARM and ARG throughout the remainder of this
14802 function; the handling is precisely symmetric since PARM
14803 will initialize ARG rather than vice versa. */
14811 /* Core issue #873: Do the DR606 thing (see below) for these cases,
14812 too, but here handle it by stripping the reference from PARM
14813 rather than by adding it to ARG. */
14814 if (TREE_CODE (*parm) == REFERENCE_TYPE
14815 && TYPE_REF_IS_RVALUE (*parm)
14816 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
14817 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
14818 && TREE_CODE (*arg) == REFERENCE_TYPE
14819 && !TYPE_REF_IS_RVALUE (*arg))
14820 *parm = TREE_TYPE (*parm);
14821 /* Nothing else to do in this case. */
14825 gcc_unreachable ();
14828 if (TREE_CODE (*parm) != REFERENCE_TYPE)
14830 /* [temp.deduct.call]
14832 If P is not a reference type:
14834 --If A is an array type, the pointer type produced by the
14835 array-to-pointer standard conversion (_conv.array_) is
14836 used in place of A for type deduction; otherwise,
14838 --If A is a function type, the pointer type produced by
14839 the function-to-pointer standard conversion
14840 (_conv.func_) is used in place of A for type deduction;
14843 --If A is a cv-qualified type, the top level
14844 cv-qualifiers of A's type are ignored for type
14846 if (TREE_CODE (*arg) == ARRAY_TYPE)
14847 *arg = build_pointer_type (TREE_TYPE (*arg));
14848 else if (TREE_CODE (*arg) == FUNCTION_TYPE)
14849 *arg = build_pointer_type (*arg);
14851 *arg = TYPE_MAIN_VARIANT (*arg);
14854 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
14855 of the form T&&, where T is a template parameter, and the argument
14856 is an lvalue, T is deduced as A& */
14857 if (TREE_CODE (*parm) == REFERENCE_TYPE
14858 && TYPE_REF_IS_RVALUE (*parm)
14859 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
14860 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
14861 && (arg_expr ? real_lvalue_p (arg_expr)
14862 /* try_one_overload doesn't provide an arg_expr, but
14863 functions are always lvalues. */
14864 : TREE_CODE (*arg) == FUNCTION_TYPE))
14865 *arg = build_reference_type (*arg);
14867 /* [temp.deduct.call]
14869 If P is a cv-qualified type, the top level cv-qualifiers
14870 of P's type are ignored for type deduction. If P is a
14871 reference type, the type referred to by P is used for
14873 *parm = TYPE_MAIN_VARIANT (*parm);
14874 if (TREE_CODE (*parm) == REFERENCE_TYPE)
14876 *parm = TREE_TYPE (*parm);
14877 result |= UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
14880 /* DR 322. For conversion deduction, remove a reference type on parm
14881 too (which has been swapped into ARG). */
14882 if (strict == DEDUCE_CONV && TREE_CODE (*arg) == REFERENCE_TYPE)
14883 *arg = TREE_TYPE (*arg);
14888 /* Subroutine of unify_one_argument. PARM is a function parameter of a
14889 template which does contain any deducible template parameters; check if
14890 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
14891 unify_one_argument. */
14894 check_non_deducible_conversion (tree parm, tree arg, int strict,
14895 int flags, bool explain_p)
14900 type = TREE_TYPE (arg);
14904 if (same_type_p (parm, type))
14905 return unify_success (explain_p);
14907 if (strict == DEDUCE_CONV)
14909 if (can_convert_arg (type, parm, NULL_TREE, flags))
14910 return unify_success (explain_p);
14912 else if (strict != DEDUCE_EXACT)
14914 if (can_convert_arg (parm, type,
14915 TYPE_P (arg) ? NULL_TREE : arg,
14917 return unify_success (explain_p);
14920 if (strict == DEDUCE_EXACT)
14921 return unify_type_mismatch (explain_p, parm, arg);
14923 return unify_arg_conversion (explain_p, parm, type, arg);
14926 /* Subroutine of type_unification_real and unify_pack_expansion to
14927 handle unification of a single P/A pair. Parameters are as
14928 for those functions. */
14931 unify_one_argument (tree tparms, tree targs, tree parm, tree arg,
14932 int subr, unification_kind_t strict, int flags,
14935 tree arg_expr = NULL_TREE;
14938 if (arg == error_mark_node || parm == error_mark_node)
14939 return unify_invalid (explain_p);
14940 if (arg == unknown_type_node)
14941 /* We can't deduce anything from this, but we might get all the
14942 template args from other function args. */
14943 return unify_success (explain_p);
14945 /* FIXME uses_deducible_template_parms */
14946 if (TYPE_P (parm) && !uses_template_parms (parm))
14947 return check_non_deducible_conversion (parm, arg, strict, flags,
14953 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
14954 | UNIFY_ALLOW_MORE_CV_QUAL
14955 | UNIFY_ALLOW_DERIVED);
14959 arg_strict = UNIFY_ALLOW_LESS_CV_QUAL;
14963 arg_strict = UNIFY_ALLOW_NONE;
14967 gcc_unreachable ();
14970 /* We only do these transformations if this is the top-level
14971 parameter_type_list in a call or declaration matching; in other
14972 situations (nested function declarators, template argument lists) we
14973 won't be comparing a type to an expression, and we don't do any type
14979 gcc_assert (TREE_TYPE (arg) != NULL_TREE);
14980 if (type_unknown_p (arg))
14982 /* [temp.deduct.type] A template-argument can be
14983 deduced from a pointer to function or pointer
14984 to member function argument if the set of
14985 overloaded functions does not contain function
14986 templates and at most one of a set of
14987 overloaded functions provides a unique
14990 if (resolve_overloaded_unification
14991 (tparms, targs, parm, arg, strict,
14992 arg_strict, explain_p))
14993 return unify_success (explain_p);
14994 return unify_overload_resolution_failure (explain_p, arg);
14998 arg = unlowered_expr_type (arg);
14999 if (arg == error_mark_node)
15000 return unify_invalid (explain_p);
15004 maybe_adjust_types_for_deduction (strict, &parm, &arg, arg_expr);
15007 gcc_assert ((TYPE_P (parm) || TREE_CODE (parm) == TEMPLATE_DECL)
15008 == (TYPE_P (arg) || TREE_CODE (arg) == TEMPLATE_DECL));
15010 /* For deduction from an init-list we need the actual list. */
15011 if (arg_expr && BRACE_ENCLOSED_INITIALIZER_P (arg_expr))
15013 return unify (tparms, targs, parm, arg, arg_strict, explain_p);
15016 /* Most parms like fn_type_unification.
15018 If SUBR is 1, we're being called recursively (to unify the
15019 arguments of a function or method parameter of a function
15023 type_unification_real (tree tparms,
15027 unsigned int xnargs,
15029 unification_kind_t strict,
15035 int ntparms = TREE_VEC_LENGTH (tparms);
15036 int saw_undeduced = 0;
15039 unsigned int nargs;
15042 gcc_assert (TREE_CODE (tparms) == TREE_VEC);
15043 gcc_assert (xparms == NULL_TREE || TREE_CODE (xparms) == TREE_LIST);
15044 gcc_assert (ntparms > 0);
15046 /* Reset the number of non-defaulted template arguments contained
15048 NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs) = NULL_TREE;
15056 while (parms && parms != void_list_node
15059 parm = TREE_VALUE (parms);
15061 if (TREE_CODE (parm) == TYPE_PACK_EXPANSION
15062 && (!TREE_CHAIN (parms) || TREE_CHAIN (parms) == void_list_node))
15063 /* For a function parameter pack that occurs at the end of the
15064 parameter-declaration-list, the type A of each remaining
15065 argument of the call is compared with the type P of the
15066 declarator-id of the function parameter pack. */
15069 parms = TREE_CHAIN (parms);
15071 if (TREE_CODE (parm) == TYPE_PACK_EXPANSION)
15072 /* For a function parameter pack that does not occur at the
15073 end of the parameter-declaration-list, the type of the
15074 parameter pack is a non-deduced context. */
15080 if (unify_one_argument (tparms, targs, parm, arg, subr, strict,
15086 && parms != void_list_node
15087 && TREE_CODE (TREE_VALUE (parms)) == TYPE_PACK_EXPANSION)
15089 /* Unify the remaining arguments with the pack expansion type. */
15091 tree parmvec = make_tree_vec (1);
15093 /* Allocate a TREE_VEC and copy in all of the arguments */
15094 argvec = make_tree_vec (nargs - ia);
15095 for (i = 0; ia < nargs; ++ia, ++i)
15096 TREE_VEC_ELT (argvec, i) = args[ia];
15098 /* Copy the parameter into parmvec. */
15099 TREE_VEC_ELT (parmvec, 0) = TREE_VALUE (parms);
15100 if (unify_pack_expansion (tparms, targs, parmvec, argvec, strict,
15101 /*subr=*/subr, explain_p))
15104 /* Advance to the end of the list of parameters. */
15105 parms = TREE_CHAIN (parms);
15108 /* Fail if we've reached the end of the parm list, and more args
15109 are present, and the parm list isn't variadic. */
15110 if (ia < nargs && parms == void_list_node)
15111 return unify_too_many_arguments (explain_p, nargs, ia);
15112 /* Fail if parms are left and they don't have default values. */
15113 if (parms && parms != void_list_node
15114 && TREE_PURPOSE (parms) == NULL_TREE)
15116 unsigned int count = nargs;
15118 while (p && p != void_list_node)
15121 p = TREE_CHAIN (p);
15123 return unify_too_few_arguments (explain_p, ia, count);
15128 tsubst_flags_t complain = (explain_p
15129 ? tf_warning_or_error
15132 /* Check to see if we need another pass before we start clearing
15133 ARGUMENT_PACK_INCOMPLETE_P. */
15134 for (i = 0; i < ntparms; i++)
15136 tree targ = TREE_VEC_ELT (targs, i);
15137 tree tparm = TREE_VEC_ELT (tparms, i);
15139 if (targ || tparm == error_mark_node)
15141 tparm = TREE_VALUE (tparm);
15143 /* If this is an undeduced nontype parameter that depends on
15144 a type parameter, try another pass; its type may have been
15145 deduced from a later argument than the one from which
15146 this parameter can be deduced. */
15147 if (TREE_CODE (tparm) == PARM_DECL
15148 && uses_template_parms (TREE_TYPE (tparm))
15149 && !saw_undeduced++)
15153 for (i = 0; i < ntparms; i++)
15155 tree targ = TREE_VEC_ELT (targs, i);
15156 tree tparm = TREE_VEC_ELT (tparms, i);
15158 /* Clear the "incomplete" flags on all argument packs now so that
15159 substituting them into later default arguments works. */
15160 if (targ && ARGUMENT_PACK_P (targ))
15162 ARGUMENT_PACK_INCOMPLETE_P (targ) = 0;
15163 ARGUMENT_PACK_EXPLICIT_ARGS (targ) = NULL_TREE;
15166 if (targ || tparm == error_mark_node)
15168 tparm = TREE_VALUE (tparm);
15170 /* Core issue #226 (C++0x) [temp.deduct]:
15172 If a template argument has not been deduced, its
15173 default template argument, if any, is used.
15175 When we are in C++98 mode, TREE_PURPOSE will either
15176 be NULL_TREE or ERROR_MARK_NODE, so we do not need
15177 to explicitly check cxx_dialect here. */
15178 if (TREE_PURPOSE (TREE_VEC_ELT (tparms, i)))
15180 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
15181 tree arg = TREE_PURPOSE (TREE_VEC_ELT (tparms, i));
15182 arg = tsubst_template_arg (arg, targs, complain, NULL_TREE);
15183 arg = convert_template_argument (parm, arg, targs, complain,
15185 if (arg == error_mark_node)
15189 TREE_VEC_ELT (targs, i) = arg;
15190 /* The position of the first default template argument,
15191 is also the number of non-defaulted arguments in TARGS.
15193 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs))
15194 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, i);
15199 /* If the type parameter is a parameter pack, then it will
15200 be deduced to an empty parameter pack. */
15201 if (template_parameter_pack_p (tparm))
15205 if (TREE_CODE (tparm) == TEMPLATE_PARM_INDEX)
15207 arg = make_node (NONTYPE_ARGUMENT_PACK);
15208 TREE_TYPE (arg) = TREE_TYPE (TEMPLATE_PARM_DECL (tparm));
15209 TREE_CONSTANT (arg) = 1;
15212 arg = cxx_make_type (TYPE_ARGUMENT_PACK);
15214 SET_ARGUMENT_PACK_ARGS (arg, make_tree_vec (0));
15216 TREE_VEC_ELT (targs, i) = arg;
15220 return unify_parameter_deduction_failure (explain_p, tparm);
15223 #ifdef ENABLE_CHECKING
15224 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs))
15225 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, TREE_VEC_LENGTH (targs));
15228 return unify_success (explain_p);
15231 /* Subroutine of type_unification_real. Args are like the variables
15232 at the call site. ARG is an overloaded function (or template-id);
15233 we try deducing template args from each of the overloads, and if
15234 only one succeeds, we go with that. Modifies TARGS and returns
15235 true on success. */
15238 resolve_overloaded_unification (tree tparms,
15242 unification_kind_t strict,
15246 tree tempargs = copy_node (targs);
15248 tree goodfn = NULL_TREE;
15251 if (TREE_CODE (arg) == ADDR_EXPR)
15253 arg = TREE_OPERAND (arg, 0);
15259 if (TREE_CODE (arg) == COMPONENT_REF)
15260 /* Handle `&x' where `x' is some static or non-static member
15262 arg = TREE_OPERAND (arg, 1);
15264 if (TREE_CODE (arg) == OFFSET_REF)
15265 arg = TREE_OPERAND (arg, 1);
15267 /* Strip baselink information. */
15268 if (BASELINK_P (arg))
15269 arg = BASELINK_FUNCTIONS (arg);
15271 if (TREE_CODE (arg) == TEMPLATE_ID_EXPR)
15273 /* If we got some explicit template args, we need to plug them into
15274 the affected templates before we try to unify, in case the
15275 explicit args will completely resolve the templates in question. */
15278 tree expl_subargs = TREE_OPERAND (arg, 1);
15279 arg = TREE_OPERAND (arg, 0);
15281 for (; arg; arg = OVL_NEXT (arg))
15283 tree fn = OVL_CURRENT (arg);
15284 tree subargs, elem;
15286 if (TREE_CODE (fn) != TEMPLATE_DECL)
15289 ++processing_template_decl;
15290 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
15291 expl_subargs, /*check_ret=*/false);
15292 if (subargs && !any_dependent_template_arguments_p (subargs))
15294 elem = tsubst (TREE_TYPE (fn), subargs, tf_none, NULL_TREE);
15295 if (try_one_overload (tparms, targs, tempargs, parm,
15296 elem, strict, sub_strict, addr_p, explain_p)
15297 && (!goodfn || !decls_match (goodfn, elem)))
15305 --processing_template_decl;
15307 /* If no templates (or more than one) are fully resolved by the
15308 explicit arguments, this template-id is a non-deduced context; it
15309 could still be OK if we deduce all template arguments for the
15310 enclosing call through other arguments. */
15314 else if (TREE_CODE (arg) != OVERLOAD
15315 && TREE_CODE (arg) != FUNCTION_DECL)
15316 /* If ARG is, for example, "(0, &f)" then its type will be unknown
15317 -- but the deduction does not succeed because the expression is
15318 not just the function on its own. */
15321 for (; arg; arg = OVL_NEXT (arg))
15322 if (try_one_overload (tparms, targs, tempargs, parm,
15323 TREE_TYPE (OVL_CURRENT (arg)),
15324 strict, sub_strict, addr_p, explain_p)
15325 && (!goodfn || !decls_match (goodfn, OVL_CURRENT (arg))))
15327 goodfn = OVL_CURRENT (arg);
15331 /* [temp.deduct.type] A template-argument can be deduced from a pointer
15332 to function or pointer to member function argument if the set of
15333 overloaded functions does not contain function templates and at most
15334 one of a set of overloaded functions provides a unique match.
15336 So if we found multiple possibilities, we return success but don't
15337 deduce anything. */
15341 int i = TREE_VEC_LENGTH (targs);
15343 if (TREE_VEC_ELT (tempargs, i))
15344 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (tempargs, i);
15352 /* Core DR 115: In contexts where deduction is done and fails, or in
15353 contexts where deduction is not done, if a template argument list is
15354 specified and it, along with any default template arguments, identifies
15355 a single function template specialization, then the template-id is an
15356 lvalue for the function template specialization. */
15359 resolve_nondeduced_context (tree orig_expr)
15361 tree expr, offset, baselink;
15364 if (!type_unknown_p (orig_expr))
15369 offset = NULL_TREE;
15370 baselink = NULL_TREE;
15372 if (TREE_CODE (expr) == ADDR_EXPR)
15374 expr = TREE_OPERAND (expr, 0);
15377 if (TREE_CODE (expr) == OFFSET_REF)
15380 expr = TREE_OPERAND (expr, 1);
15382 if (BASELINK_P (expr))
15385 expr = BASELINK_FUNCTIONS (expr);
15388 if (TREE_CODE (expr) == TEMPLATE_ID_EXPR)
15391 tree goodfn = NULL_TREE;
15393 /* If we got some explicit template args, we need to plug them into
15394 the affected templates before we try to unify, in case the
15395 explicit args will completely resolve the templates in question. */
15397 tree expl_subargs = TREE_OPERAND (expr, 1);
15398 tree arg = TREE_OPERAND (expr, 0);
15399 tree badfn = NULL_TREE;
15400 tree badargs = NULL_TREE;
15402 for (; arg; arg = OVL_NEXT (arg))
15404 tree fn = OVL_CURRENT (arg);
15405 tree subargs, elem;
15407 if (TREE_CODE (fn) != TEMPLATE_DECL)
15410 ++processing_template_decl;
15411 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
15412 expl_subargs, /*check_ret=*/false);
15413 if (subargs && !any_dependent_template_arguments_p (subargs))
15415 elem = instantiate_template (fn, subargs, tf_none);
15416 if (elem == error_mark_node)
15421 else if (elem && (!goodfn || !decls_match (goodfn, elem)))
15427 --processing_template_decl;
15431 mark_used (goodfn);
15434 expr = build_baselink (BASELINK_BINFO (baselink),
15435 BASELINK_ACCESS_BINFO (baselink),
15436 expr, BASELINK_OPTYPE (baselink));
15440 = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (offset, 0)));
15441 expr = build_offset_ref (base, expr, addr);
15444 expr = cp_build_addr_expr (expr, tf_warning_or_error);
15447 else if (good == 0 && badargs)
15448 /* There were no good options and at least one bad one, so let the
15449 user know what the problem is. */
15450 instantiate_template (badfn, badargs, tf_warning_or_error);
15455 /* Subroutine of resolve_overloaded_unification; does deduction for a single
15456 overload. Fills TARGS with any deduced arguments, or error_mark_node if
15457 different overloads deduce different arguments for a given parm.
15458 ADDR_P is true if the expression for which deduction is being
15459 performed was of the form "& fn" rather than simply "fn".
15461 Returns 1 on success. */
15464 try_one_overload (tree tparms,
15469 unification_kind_t strict,
15478 /* [temp.deduct.type] A template-argument can be deduced from a pointer
15479 to function or pointer to member function argument if the set of
15480 overloaded functions does not contain function templates and at most
15481 one of a set of overloaded functions provides a unique match.
15483 So if this is a template, just return success. */
15485 if (uses_template_parms (arg))
15488 if (TREE_CODE (arg) == METHOD_TYPE)
15489 arg = build_ptrmemfunc_type (build_pointer_type (arg));
15491 arg = build_pointer_type (arg);
15493 sub_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg, NULL);
15495 /* We don't copy orig_targs for this because if we have already deduced
15496 some template args from previous args, unify would complain when we
15497 try to deduce a template parameter for the same argument, even though
15498 there isn't really a conflict. */
15499 nargs = TREE_VEC_LENGTH (targs);
15500 tempargs = make_tree_vec (nargs);
15502 if (unify (tparms, tempargs, parm, arg, sub_strict, explain_p))
15505 /* First make sure we didn't deduce anything that conflicts with
15506 explicitly specified args. */
15507 for (i = nargs; i--; )
15509 tree elt = TREE_VEC_ELT (tempargs, i);
15510 tree oldelt = TREE_VEC_ELT (orig_targs, i);
15514 else if (uses_template_parms (elt))
15515 /* Since we're unifying against ourselves, we will fill in
15516 template args used in the function parm list with our own
15517 template parms. Discard them. */
15518 TREE_VEC_ELT (tempargs, i) = NULL_TREE;
15519 else if (oldelt && !template_args_equal (oldelt, elt))
15523 for (i = nargs; i--; )
15525 tree elt = TREE_VEC_ELT (tempargs, i);
15528 TREE_VEC_ELT (targs, i) = elt;
15534 /* PARM is a template class (perhaps with unbound template
15535 parameters). ARG is a fully instantiated type. If ARG can be
15536 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
15537 TARGS are as for unify. */
15540 try_class_unification (tree tparms, tree targs, tree parm, tree arg,
15543 tree copy_of_targs;
15545 if (!CLASSTYPE_TEMPLATE_INFO (arg)
15546 || (most_general_template (CLASSTYPE_TI_TEMPLATE (arg))
15547 != most_general_template (CLASSTYPE_TI_TEMPLATE (parm))))
15550 /* We need to make a new template argument vector for the call to
15551 unify. If we used TARGS, we'd clutter it up with the result of
15552 the attempted unification, even if this class didn't work out.
15553 We also don't want to commit ourselves to all the unifications
15554 we've already done, since unification is supposed to be done on
15555 an argument-by-argument basis. In other words, consider the
15556 following pathological case:
15558 template <int I, int J, int K>
15561 template <int I, int J>
15562 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
15564 template <int I, int J, int K>
15565 void f(S<I, J, K>, S<I, I, I>);
15574 Now, by the time we consider the unification involving `s2', we
15575 already know that we must have `f<0, 0, 0>'. But, even though
15576 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
15577 because there are two ways to unify base classes of S<0, 1, 2>
15578 with S<I, I, I>. If we kept the already deduced knowledge, we
15579 would reject the possibility I=1. */
15580 copy_of_targs = make_tree_vec (TREE_VEC_LENGTH (targs));
15582 /* If unification failed, we're done. */
15583 if (unify (tparms, copy_of_targs, CLASSTYPE_TI_ARGS (parm),
15584 CLASSTYPE_TI_ARGS (arg), UNIFY_ALLOW_NONE, explain_p))
15590 /* Given a template type PARM and a class type ARG, find the unique
15591 base type in ARG that is an instance of PARM. We do not examine
15592 ARG itself; only its base-classes. If there is not exactly one
15593 appropriate base class, return NULL_TREE. PARM may be the type of
15594 a partial specialization, as well as a plain template type. Used
15597 static enum template_base_result
15598 get_template_base (tree tparms, tree targs, tree parm, tree arg,
15599 bool explain_p, tree *result)
15601 tree rval = NULL_TREE;
15604 gcc_assert (RECORD_OR_UNION_CODE_P (TREE_CODE (arg)));
15606 binfo = TYPE_BINFO (complete_type (arg));
15609 /* The type could not be completed. */
15610 *result = NULL_TREE;
15611 return tbr_incomplete_type;
15614 /* Walk in inheritance graph order. The search order is not
15615 important, and this avoids multiple walks of virtual bases. */
15616 for (binfo = TREE_CHAIN (binfo); binfo; binfo = TREE_CHAIN (binfo))
15618 tree r = try_class_unification (tparms, targs, parm,
15619 BINFO_TYPE (binfo), explain_p);
15623 /* If there is more than one satisfactory baseclass, then:
15627 If they yield more than one possible deduced A, the type
15631 if (rval && !same_type_p (r, rval))
15633 *result = NULL_TREE;
15634 return tbr_ambiguous_baseclass;
15642 return tbr_success;
15645 /* Returns the level of DECL, which declares a template parameter. */
15648 template_decl_level (tree decl)
15650 switch (TREE_CODE (decl))
15653 case TEMPLATE_DECL:
15654 return TEMPLATE_TYPE_LEVEL (TREE_TYPE (decl));
15657 return TEMPLATE_PARM_LEVEL (DECL_INITIAL (decl));
15660 gcc_unreachable ();
15665 /* Decide whether ARG can be unified with PARM, considering only the
15666 cv-qualifiers of each type, given STRICT as documented for unify.
15667 Returns nonzero iff the unification is OK on that basis. */
15670 check_cv_quals_for_unify (int strict, tree arg, tree parm)
15672 int arg_quals = cp_type_quals (arg);
15673 int parm_quals = cp_type_quals (parm);
15675 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
15676 && !(strict & UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
15678 /* Although a CVR qualifier is ignored when being applied to a
15679 substituted template parameter ([8.3.2]/1 for example), that
15680 does not allow us to unify "const T" with "int&" because both
15681 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
15682 It is ok when we're allowing additional CV qualifiers
15683 at the outer level [14.8.2.1]/3,1st bullet. */
15684 if ((TREE_CODE (arg) == REFERENCE_TYPE
15685 || TREE_CODE (arg) == FUNCTION_TYPE
15686 || TREE_CODE (arg) == METHOD_TYPE)
15687 && (parm_quals & (TYPE_QUAL_CONST | TYPE_QUAL_VOLATILE)))
15690 if ((!POINTER_TYPE_P (arg) && TREE_CODE (arg) != TEMPLATE_TYPE_PARM)
15691 && (parm_quals & TYPE_QUAL_RESTRICT))
15695 if (!(strict & (UNIFY_ALLOW_MORE_CV_QUAL | UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
15696 && (arg_quals & parm_quals) != parm_quals)
15699 if (!(strict & (UNIFY_ALLOW_LESS_CV_QUAL | UNIFY_ALLOW_OUTER_LESS_CV_QUAL))
15700 && (parm_quals & arg_quals) != arg_quals)
15706 /* Determines the LEVEL and INDEX for the template parameter PARM. */
15708 template_parm_level_and_index (tree parm, int* level, int* index)
15710 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
15711 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
15712 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
15714 *index = TEMPLATE_TYPE_IDX (parm);
15715 *level = TEMPLATE_TYPE_LEVEL (parm);
15719 *index = TEMPLATE_PARM_IDX (parm);
15720 *level = TEMPLATE_PARM_LEVEL (parm);
15724 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
15726 if (unify (TP, TA, P, A, S, EP)) \
15730 /* Unifies the remaining arguments in PACKED_ARGS with the pack
15731 expansion at the end of PACKED_PARMS. Returns 0 if the type
15732 deduction succeeds, 1 otherwise. STRICT is the same as in
15733 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
15734 call argument list. We'll need to adjust the arguments to make them
15735 types. SUBR tells us if this is from a recursive call to
15736 type_unification_real, or for comparing two template argument
15740 unify_pack_expansion (tree tparms, tree targs, tree packed_parms,
15741 tree packed_args, unification_kind_t strict,
15742 bool subr, bool explain_p)
15745 = TREE_VEC_ELT (packed_parms, TREE_VEC_LENGTH (packed_parms) - 1);
15746 tree pattern = PACK_EXPANSION_PATTERN (parm);
15747 tree pack, packs = NULL_TREE;
15748 int i, start = TREE_VEC_LENGTH (packed_parms) - 1;
15749 int len = TREE_VEC_LENGTH (packed_args);
15751 /* Determine the parameter packs we will be deducing from the
15752 pattern, and record their current deductions. */
15753 for (pack = PACK_EXPANSION_PARAMETER_PACKS (parm);
15754 pack; pack = TREE_CHAIN (pack))
15756 tree parm_pack = TREE_VALUE (pack);
15759 /* Determine the index and level of this parameter pack. */
15760 template_parm_level_and_index (parm_pack, &level, &idx);
15762 /* Keep track of the parameter packs and their corresponding
15764 packs = tree_cons (parm_pack, TMPL_ARG (targs, level, idx), packs);
15765 TREE_TYPE (packs) = make_tree_vec (len - start);
15768 /* Loop through all of the arguments that have not yet been
15769 unified and unify each with the pattern. */
15770 for (i = start; i < len; i++)
15773 bool any_explicit = false;
15774 tree arg = TREE_VEC_ELT (packed_args, i);
15776 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
15777 or the element of its argument pack at the current index if
15778 this argument was explicitly specified. */
15779 for (pack = packs; pack; pack = TREE_CHAIN (pack))
15783 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
15786 if (TREE_VALUE (pack)
15787 && (pargs = ARGUMENT_PACK_EXPLICIT_ARGS (TREE_VALUE (pack)))
15788 && (i < TREE_VEC_LENGTH (pargs)))
15790 any_explicit = true;
15791 arg = TREE_VEC_ELT (pargs, i);
15793 TMPL_ARG (targs, level, idx) = arg;
15796 /* If we had explicit template arguments, substitute them into the
15797 pattern before deduction. */
15800 /* Some arguments might still be unspecified or dependent. */
15802 ++processing_template_decl;
15803 dependent = any_dependent_template_arguments_p (targs);
15805 --processing_template_decl;
15806 parm = tsubst (pattern, targs,
15807 explain_p ? tf_warning_or_error : tf_none,
15810 --processing_template_decl;
15811 if (parm == error_mark_node)
15817 /* Unify the pattern with the current argument. */
15818 if (unify_one_argument (tparms, targs, parm, arg, subr, strict,
15819 LOOKUP_IMPLICIT, explain_p))
15822 /* For each parameter pack, collect the deduced value. */
15823 for (pack = packs; pack; pack = TREE_CHAIN (pack))
15826 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
15828 TREE_VEC_ELT (TREE_TYPE (pack), i - start) =
15829 TMPL_ARG (targs, level, idx);
15833 /* Verify that the results of unification with the parameter packs
15834 produce results consistent with what we've seen before, and make
15835 the deduced argument packs available. */
15836 for (pack = packs; pack; pack = TREE_CHAIN (pack))
15838 tree old_pack = TREE_VALUE (pack);
15839 tree new_args = TREE_TYPE (pack);
15840 int i, len = TREE_VEC_LENGTH (new_args);
15842 bool nondeduced_p = false;
15844 /* By default keep the original deduced argument pack.
15845 If necessary, more specific code is going to update the
15846 resulting deduced argument later down in this function. */
15847 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
15848 TMPL_ARG (targs, level, idx) = old_pack;
15850 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
15851 actually deduce anything. */
15852 for (i = 0; i < len && !nondeduced_p; ++i)
15853 if (TREE_VEC_ELT (new_args, i) == NULL_TREE)
15854 nondeduced_p = true;
15858 if (old_pack && ARGUMENT_PACK_INCOMPLETE_P (old_pack))
15860 /* If we had fewer function args than explicit template args,
15861 just use the explicits. */
15862 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
15863 int explicit_len = TREE_VEC_LENGTH (explicit_args);
15864 if (len < explicit_len)
15865 new_args = explicit_args;
15871 /* Build the deduced *_ARGUMENT_PACK. */
15872 if (TREE_CODE (TREE_PURPOSE (pack)) == TEMPLATE_PARM_INDEX)
15874 result = make_node (NONTYPE_ARGUMENT_PACK);
15875 TREE_TYPE (result) =
15876 TREE_TYPE (TEMPLATE_PARM_DECL (TREE_PURPOSE (pack)));
15877 TREE_CONSTANT (result) = 1;
15880 result = cxx_make_type (TYPE_ARGUMENT_PACK);
15882 SET_ARGUMENT_PACK_ARGS (result, new_args);
15884 /* Note the deduced argument packs for this parameter
15886 TMPL_ARG (targs, level, idx) = result;
15888 else if (ARGUMENT_PACK_INCOMPLETE_P (old_pack)
15889 && (ARGUMENT_PACK_ARGS (old_pack)
15890 == ARGUMENT_PACK_EXPLICIT_ARGS (old_pack)))
15892 /* We only had the explicitly-provided arguments before, but
15893 now we have a complete set of arguments. */
15894 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
15896 SET_ARGUMENT_PACK_ARGS (old_pack, new_args);
15897 ARGUMENT_PACK_INCOMPLETE_P (old_pack) = 1;
15898 ARGUMENT_PACK_EXPLICIT_ARGS (old_pack) = explicit_args;
15902 tree bad_old_arg = NULL_TREE, bad_new_arg = NULL_TREE;
15903 tree old_args = ARGUMENT_PACK_ARGS (old_pack);
15905 if (!comp_template_args_with_info (old_args, new_args,
15906 &bad_old_arg, &bad_new_arg))
15907 /* Inconsistent unification of this parameter pack. */
15908 return unify_parameter_pack_inconsistent (explain_p,
15914 return unify_success (explain_p);
15917 /* Deduce the value of template parameters. TPARMS is the (innermost)
15918 set of template parameters to a template. TARGS is the bindings
15919 for those template parameters, as determined thus far; TARGS may
15920 include template arguments for outer levels of template parameters
15921 as well. PARM is a parameter to a template function, or a
15922 subcomponent of that parameter; ARG is the corresponding argument.
15923 This function attempts to match PARM with ARG in a manner
15924 consistent with the existing assignments in TARGS. If more values
15925 are deduced, then TARGS is updated.
15927 Returns 0 if the type deduction succeeds, 1 otherwise. The
15928 parameter STRICT is a bitwise or of the following flags:
15931 Require an exact match between PARM and ARG.
15932 UNIFY_ALLOW_MORE_CV_QUAL:
15933 Allow the deduced ARG to be more cv-qualified (by qualification
15934 conversion) than ARG.
15935 UNIFY_ALLOW_LESS_CV_QUAL:
15936 Allow the deduced ARG to be less cv-qualified than ARG.
15937 UNIFY_ALLOW_DERIVED:
15938 Allow the deduced ARG to be a template base class of ARG,
15939 or a pointer to a template base class of the type pointed to by
15941 UNIFY_ALLOW_INTEGER:
15942 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
15943 case for more information.
15944 UNIFY_ALLOW_OUTER_LEVEL:
15945 This is the outermost level of a deduction. Used to determine validity
15946 of qualification conversions. A valid qualification conversion must
15947 have const qualified pointers leading up to the inner type which
15948 requires additional CV quals, except at the outer level, where const
15949 is not required [conv.qual]. It would be normal to set this flag in
15950 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
15951 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
15952 This is the outermost level of a deduction, and PARM can be more CV
15953 qualified at this point.
15954 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
15955 This is the outermost level of a deduction, and PARM can be less CV
15956 qualified at this point. */
15959 unify (tree tparms, tree targs, tree parm, tree arg, int strict,
15965 int strict_in = strict;
15967 /* I don't think this will do the right thing with respect to types.
15968 But the only case I've seen it in so far has been array bounds, where
15969 signedness is the only information lost, and I think that will be
15971 while (TREE_CODE (parm) == NOP_EXPR)
15972 parm = TREE_OPERAND (parm, 0);
15974 if (arg == error_mark_node)
15975 return unify_invalid (explain_p);
15976 if (arg == unknown_type_node
15977 || arg == init_list_type_node)
15978 /* We can't deduce anything from this, but we might get all the
15979 template args from other function args. */
15980 return unify_success (explain_p);
15982 /* If PARM uses template parameters, then we can't bail out here,
15983 even if ARG == PARM, since we won't record unifications for the
15984 template parameters. We might need them if we're trying to
15985 figure out which of two things is more specialized. */
15986 if (arg == parm && !uses_template_parms (parm))
15987 return unify_success (explain_p);
15989 /* Handle init lists early, so the rest of the function can assume
15990 we're dealing with a type. */
15991 if (BRACE_ENCLOSED_INITIALIZER_P (arg))
15995 tree orig_parm = parm;
15997 /* Replace T with std::initializer_list<T> for deduction. */
15998 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
15999 && flag_deduce_init_list)
16000 parm = listify (parm);
16002 if (!is_std_init_list (parm))
16003 /* We can only deduce from an initializer list argument if the
16004 parameter is std::initializer_list; otherwise this is a
16005 non-deduced context. */
16006 return unify_success (explain_p);
16008 elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (parm), 0);
16010 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg), i, elt)
16012 int elt_strict = strict;
16014 if (elt == error_mark_node)
16015 return unify_invalid (explain_p);
16017 if (!BRACE_ENCLOSED_INITIALIZER_P (elt))
16019 tree type = TREE_TYPE (elt);
16020 /* It should only be possible to get here for a call. */
16021 gcc_assert (elt_strict & UNIFY_ALLOW_OUTER_LEVEL);
16022 elt_strict |= maybe_adjust_types_for_deduction
16023 (DEDUCE_CALL, &elttype, &type, elt);
16027 RECUR_AND_CHECK_FAILURE (tparms, targs, elttype, elt, elt_strict,
16031 /* If the std::initializer_list<T> deduction worked, replace the
16032 deduced A with std::initializer_list<A>. */
16033 if (orig_parm != parm)
16035 idx = TEMPLATE_TYPE_IDX (orig_parm);
16036 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
16037 targ = listify (targ);
16038 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = targ;
16040 return unify_success (explain_p);
16043 /* Immediately reject some pairs that won't unify because of
16044 cv-qualification mismatches. */
16045 if (TREE_CODE (arg) == TREE_CODE (parm)
16047 /* It is the elements of the array which hold the cv quals of an array
16048 type, and the elements might be template type parms. We'll check
16049 when we recurse. */
16050 && TREE_CODE (arg) != ARRAY_TYPE
16051 /* We check the cv-qualifiers when unifying with template type
16052 parameters below. We want to allow ARG `const T' to unify with
16053 PARM `T' for example, when computing which of two templates
16054 is more specialized, for example. */
16055 && TREE_CODE (arg) != TEMPLATE_TYPE_PARM
16056 && !check_cv_quals_for_unify (strict_in, arg, parm))
16057 return unify_cv_qual_mismatch (explain_p, parm, arg);
16059 if (!(strict & UNIFY_ALLOW_OUTER_LEVEL)
16060 && TYPE_P (parm) && !CP_TYPE_CONST_P (parm))
16061 strict &= ~UNIFY_ALLOW_MORE_CV_QUAL;
16062 strict &= ~UNIFY_ALLOW_OUTER_LEVEL;
16063 strict &= ~UNIFY_ALLOW_DERIVED;
16064 strict &= ~UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
16065 strict &= ~UNIFY_ALLOW_OUTER_LESS_CV_QUAL;
16067 switch (TREE_CODE (parm))
16069 case TYPENAME_TYPE:
16071 case UNBOUND_CLASS_TEMPLATE:
16072 /* In a type which contains a nested-name-specifier, template
16073 argument values cannot be deduced for template parameters used
16074 within the nested-name-specifier. */
16075 return unify_success (explain_p);
16077 case TEMPLATE_TYPE_PARM:
16078 case TEMPLATE_TEMPLATE_PARM:
16079 case BOUND_TEMPLATE_TEMPLATE_PARM:
16080 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
16081 if (tparm == error_mark_node)
16082 return unify_invalid (explain_p);
16084 if (TEMPLATE_TYPE_LEVEL (parm)
16085 != template_decl_level (tparm))
16086 /* The PARM is not one we're trying to unify. Just check
16087 to see if it matches ARG. */
16089 if (TREE_CODE (arg) == TREE_CODE (parm)
16090 && same_type_p (parm, arg))
16091 return unify_success (explain_p);
16093 return unify_type_mismatch (explain_p, parm, arg);
16095 idx = TEMPLATE_TYPE_IDX (parm);
16096 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
16097 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, idx));
16099 /* Check for mixed types and values. */
16100 if ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
16101 && TREE_CODE (tparm) != TYPE_DECL)
16102 || (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
16103 && TREE_CODE (tparm) != TEMPLATE_DECL))
16104 gcc_unreachable ();
16106 if (TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
16108 /* ARG must be constructed from a template class or a template
16109 template parameter. */
16110 if (TREE_CODE (arg) != BOUND_TEMPLATE_TEMPLATE_PARM
16111 && !CLASSTYPE_SPECIALIZATION_OF_PRIMARY_TEMPLATE_P (arg))
16112 return unify_template_deduction_failure (explain_p, parm, arg);
16115 tree parmvec = TYPE_TI_ARGS (parm);
16116 tree argvec = INNERMOST_TEMPLATE_ARGS (TYPE_TI_ARGS (arg));
16117 tree full_argvec = add_to_template_args (targs, argvec);
16119 = DECL_INNERMOST_TEMPLATE_PARMS
16120 (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (parm));
16122 int parm_variadic_p = 0;
16124 /* The resolution to DR150 makes clear that default
16125 arguments for an N-argument may not be used to bind T
16126 to a template template parameter with fewer than N
16127 parameters. It is not safe to permit the binding of
16128 default arguments as an extension, as that may change
16129 the meaning of a conforming program. Consider:
16131 struct Dense { static const unsigned int dim = 1; };
16133 template <template <typename> class View,
16135 void operator+(float, View<Block> const&);
16137 template <typename Block,
16138 unsigned int Dim = Block::dim>
16139 struct Lvalue_proxy { operator float() const; };
16143 Lvalue_proxy<Dense> p;
16148 Here, if Lvalue_proxy is permitted to bind to View, then
16149 the global operator+ will be used; if they are not, the
16150 Lvalue_proxy will be converted to float. */
16151 if (coerce_template_parms (parm_parms,
16153 TYPE_TI_TEMPLATE (parm),
16155 ? tf_warning_or_error
16157 /*require_all_args=*/true,
16158 /*use_default_args=*/false)
16159 == error_mark_node)
16162 /* Deduce arguments T, i from TT<T> or TT<i>.
16163 We check each element of PARMVEC and ARGVEC individually
16164 rather than the whole TREE_VEC since they can have
16165 different number of elements. */
16167 parmvec = expand_template_argument_pack (parmvec);
16168 argvec = expand_template_argument_pack (argvec);
16170 len = TREE_VEC_LENGTH (parmvec);
16172 /* Check if the parameters end in a pack, making them
16175 && PACK_EXPANSION_P (TREE_VEC_ELT (parmvec, len - 1)))
16176 parm_variadic_p = 1;
16178 if (TREE_VEC_LENGTH (argvec) < len - parm_variadic_p)
16179 return unify_too_few_arguments (explain_p,
16180 TREE_VEC_LENGTH (argvec), len);
16182 for (i = 0; i < len - parm_variadic_p; ++i)
16184 RECUR_AND_CHECK_FAILURE (tparms, targs,
16185 TREE_VEC_ELT (parmvec, i),
16186 TREE_VEC_ELT (argvec, i),
16187 UNIFY_ALLOW_NONE, explain_p);
16190 if (parm_variadic_p
16191 && unify_pack_expansion (tparms, targs,
16194 /*subr=*/true, explain_p))
16197 arg = TYPE_TI_TEMPLATE (arg);
16199 /* Fall through to deduce template name. */
16202 if (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
16203 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
16205 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
16207 /* Simple cases: Value already set, does match or doesn't. */
16208 if (targ != NULL_TREE && template_args_equal (targ, arg))
16209 return unify_success (explain_p);
16211 return unify_inconsistency (explain_p, parm, targ, arg);
16215 /* If PARM is `const T' and ARG is only `int', we don't have
16216 a match unless we are allowing additional qualification.
16217 If ARG is `const int' and PARM is just `T' that's OK;
16218 that binds `const int' to `T'. */
16219 if (!check_cv_quals_for_unify (strict_in | UNIFY_ALLOW_LESS_CV_QUAL,
16221 return unify_cv_qual_mismatch (explain_p, parm, arg);
16223 /* Consider the case where ARG is `const volatile int' and
16224 PARM is `const T'. Then, T should be `volatile int'. */
16225 arg = cp_build_qualified_type_real
16226 (arg, cp_type_quals (arg) & ~cp_type_quals (parm), tf_none);
16227 if (arg == error_mark_node)
16228 return unify_invalid (explain_p);
16230 /* Simple cases: Value already set, does match or doesn't. */
16231 if (targ != NULL_TREE && same_type_p (targ, arg))
16232 return unify_success (explain_p);
16234 return unify_inconsistency (explain_p, parm, targ, arg);
16236 /* Make sure that ARG is not a variable-sized array. (Note
16237 that were talking about variable-sized arrays (like
16238 `int[n]'), rather than arrays of unknown size (like
16239 `int[]').) We'll get very confused by such a type since
16240 the bound of the array is not constant, and therefore
16241 not mangleable. Besides, such types are not allowed in
16242 ISO C++, so we can do as we please here. We do allow
16243 them for 'auto' deduction, since that isn't ABI-exposed. */
16244 if (!is_auto (parm) && variably_modified_type_p (arg, NULL_TREE))
16245 return unify_vla_arg (explain_p, arg);
16247 /* Strip typedefs as in convert_template_argument. */
16248 arg = canonicalize_type_argument (arg, tf_none);
16251 /* If ARG is a parameter pack or an expansion, we cannot unify
16252 against it unless PARM is also a parameter pack. */
16253 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
16254 && !template_parameter_pack_p (parm))
16255 return unify_parameter_pack_mismatch (explain_p, parm, arg);
16257 /* If the argument deduction results is a METHOD_TYPE,
16258 then there is a problem.
16259 METHOD_TYPE doesn't map to any real C++ type the result of
16260 the deduction can not be of that type. */
16261 if (TREE_CODE (arg) == METHOD_TYPE)
16262 return unify_method_type_error (explain_p, arg);
16264 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
16265 return unify_success (explain_p);
16267 case TEMPLATE_PARM_INDEX:
16268 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
16269 if (tparm == error_mark_node)
16270 return unify_invalid (explain_p);
16272 if (TEMPLATE_PARM_LEVEL (parm)
16273 != template_decl_level (tparm))
16275 /* The PARM is not one we're trying to unify. Just check
16276 to see if it matches ARG. */
16277 int result = !(TREE_CODE (arg) == TREE_CODE (parm)
16278 && cp_tree_equal (parm, arg));
16280 unify_expression_unequal (explain_p, parm, arg);
16284 idx = TEMPLATE_PARM_IDX (parm);
16285 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
16289 int x = !cp_tree_equal (targ, arg);
16291 unify_inconsistency (explain_p, parm, targ, arg);
16295 /* [temp.deduct.type] If, in the declaration of a function template
16296 with a non-type template-parameter, the non-type
16297 template-parameter is used in an expression in the function
16298 parameter-list and, if the corresponding template-argument is
16299 deduced, the template-argument type shall match the type of the
16300 template-parameter exactly, except that a template-argument
16301 deduced from an array bound may be of any integral type.
16302 The non-type parameter might use already deduced type parameters. */
16303 tparm = tsubst (TREE_TYPE (parm), targs, 0, NULL_TREE);
16304 if (!TREE_TYPE (arg))
16305 /* Template-parameter dependent expression. Just accept it for now.
16306 It will later be processed in convert_template_argument. */
16308 else if (same_type_p (TREE_TYPE (arg), tparm))
16310 else if ((strict & UNIFY_ALLOW_INTEGER)
16311 && (TREE_CODE (tparm) == INTEGER_TYPE
16312 || TREE_CODE (tparm) == BOOLEAN_TYPE))
16313 /* Convert the ARG to the type of PARM; the deduced non-type
16314 template argument must exactly match the types of the
16315 corresponding parameter. */
16316 arg = fold (build_nop (tparm, arg));
16317 else if (uses_template_parms (tparm))
16318 /* We haven't deduced the type of this parameter yet. Try again
16320 return unify_success (explain_p);
16322 return unify_type_mismatch (explain_p, tparm, arg);
16324 /* If ARG is a parameter pack or an expansion, we cannot unify
16325 against it unless PARM is also a parameter pack. */
16326 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
16327 && !TEMPLATE_PARM_PARAMETER_PACK (parm))
16328 return unify_parameter_pack_mismatch (explain_p, parm, arg);
16330 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
16331 return unify_success (explain_p);
16335 /* A pointer-to-member constant can be unified only with
16336 another constant. */
16337 if (TREE_CODE (arg) != PTRMEM_CST)
16338 return unify_ptrmem_cst_mismatch (explain_p, parm, arg);
16340 /* Just unify the class member. It would be useless (and possibly
16341 wrong, depending on the strict flags) to unify also
16342 PTRMEM_CST_CLASS, because we want to be sure that both parm and
16343 arg refer to the same variable, even if through different
16344 classes. For instance:
16346 struct A { int x; };
16349 Unification of &A::x and &B::x must succeed. */
16350 return unify (tparms, targs, PTRMEM_CST_MEMBER (parm),
16351 PTRMEM_CST_MEMBER (arg), strict, explain_p);
16356 if (TREE_CODE (arg) != POINTER_TYPE)
16357 return unify_type_mismatch (explain_p, parm, arg);
16359 /* [temp.deduct.call]
16361 A can be another pointer or pointer to member type that can
16362 be converted to the deduced A via a qualification
16363 conversion (_conv.qual_).
16365 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
16366 This will allow for additional cv-qualification of the
16367 pointed-to types if appropriate. */
16369 if (TREE_CODE (TREE_TYPE (arg)) == RECORD_TYPE)
16370 /* The derived-to-base conversion only persists through one
16371 level of pointers. */
16372 strict |= (strict_in & UNIFY_ALLOW_DERIVED);
16374 return unify (tparms, targs, TREE_TYPE (parm),
16375 TREE_TYPE (arg), strict, explain_p);
16378 case REFERENCE_TYPE:
16379 if (TREE_CODE (arg) != REFERENCE_TYPE)
16380 return unify_type_mismatch (explain_p, parm, arg);
16381 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
16382 strict & UNIFY_ALLOW_MORE_CV_QUAL, explain_p);
16385 if (TREE_CODE (arg) != ARRAY_TYPE)
16386 return unify_type_mismatch (explain_p, parm, arg);
16387 if ((TYPE_DOMAIN (parm) == NULL_TREE)
16388 != (TYPE_DOMAIN (arg) == NULL_TREE))
16389 return unify_type_mismatch (explain_p, parm, arg);
16390 if (TYPE_DOMAIN (parm) != NULL_TREE)
16397 /* Our representation of array types uses "N - 1" as the
16398 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
16399 not an integer constant. We cannot unify arbitrarily
16400 complex expressions, so we eliminate the MINUS_EXPRs
16402 parm_max = TYPE_MAX_VALUE (TYPE_DOMAIN (parm));
16403 parm_cst = TREE_CODE (parm_max) == INTEGER_CST;
16406 gcc_assert (TREE_CODE (parm_max) == MINUS_EXPR);
16407 parm_max = TREE_OPERAND (parm_max, 0);
16409 arg_max = TYPE_MAX_VALUE (TYPE_DOMAIN (arg));
16410 arg_cst = TREE_CODE (arg_max) == INTEGER_CST;
16413 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
16414 trying to unify the type of a variable with the type
16415 of a template parameter. For example:
16417 template <unsigned int N>
16418 void f (char (&) [N]);
16425 Here, the type of the ARG will be "int [g(i)]", and
16426 may be a SAVE_EXPR, etc. */
16427 if (TREE_CODE (arg_max) != MINUS_EXPR)
16428 return unify_vla_arg (explain_p, arg);
16429 arg_max = TREE_OPERAND (arg_max, 0);
16432 /* If only one of the bounds used a MINUS_EXPR, compensate
16433 by adding one to the other bound. */
16434 if (parm_cst && !arg_cst)
16435 parm_max = fold_build2_loc (input_location, PLUS_EXPR,
16439 else if (arg_cst && !parm_cst)
16440 arg_max = fold_build2_loc (input_location, PLUS_EXPR,
16445 RECUR_AND_CHECK_FAILURE (tparms, targs, parm_max, arg_max,
16446 UNIFY_ALLOW_INTEGER, explain_p);
16448 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
16449 strict & UNIFY_ALLOW_MORE_CV_QUAL, explain_p);
16456 case ENUMERAL_TYPE:
16458 if (TREE_CODE (arg) != TREE_CODE (parm))
16459 return unify_type_mismatch (explain_p, parm, arg);
16461 /* We have already checked cv-qualification at the top of the
16463 if (!same_type_ignoring_top_level_qualifiers_p (arg, parm))
16464 return unify_type_mismatch (explain_p, parm, arg);
16466 /* As far as unification is concerned, this wins. Later checks
16467 will invalidate it if necessary. */
16468 return unify_success (explain_p);
16470 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
16471 /* Type INTEGER_CST can come from ordinary constant template args. */
16473 while (TREE_CODE (arg) == NOP_EXPR)
16474 arg = TREE_OPERAND (arg, 0);
16476 if (TREE_CODE (arg) != INTEGER_CST)
16477 return unify_template_argument_mismatch (explain_p, parm, arg);
16478 return (tree_int_cst_equal (parm, arg)
16479 ? unify_success (explain_p)
16480 : unify_template_argument_mismatch (explain_p, parm, arg));
16484 int i, len, argslen;
16485 int parm_variadic_p = 0;
16487 if (TREE_CODE (arg) != TREE_VEC)
16488 return unify_template_argument_mismatch (explain_p, parm, arg);
16490 len = TREE_VEC_LENGTH (parm);
16491 argslen = TREE_VEC_LENGTH (arg);
16493 /* Check for pack expansions in the parameters. */
16494 for (i = 0; i < len; ++i)
16496 if (PACK_EXPANSION_P (TREE_VEC_ELT (parm, i)))
16499 /* We can unify against something with a trailing
16501 parm_variadic_p = 1;
16503 /* [temp.deduct.type]/9: If the template argument list of
16504 P contains a pack expansion that is not the last
16505 template argument, the entire template argument list
16506 is a non-deduced context. */
16507 return unify_success (explain_p);
16511 /* If we don't have enough arguments to satisfy the parameters
16512 (not counting the pack expression at the end), or we have
16513 too many arguments for a parameter list that doesn't end in
16514 a pack expression, we can't unify. */
16515 if (parm_variadic_p
16516 ? argslen < len - parm_variadic_p
16518 return unify_arity (explain_p, TREE_VEC_LENGTH (arg), len);
16520 /* Unify all of the parameters that precede the (optional)
16521 pack expression. */
16522 for (i = 0; i < len - parm_variadic_p; ++i)
16524 RECUR_AND_CHECK_FAILURE (tparms, targs,
16525 TREE_VEC_ELT (parm, i),
16526 TREE_VEC_ELT (arg, i),
16527 UNIFY_ALLOW_NONE, explain_p);
16529 if (parm_variadic_p)
16530 return unify_pack_expansion (tparms, targs, parm, arg,
16532 /*subr=*/true, explain_p);
16533 return unify_success (explain_p);
16538 if (TREE_CODE (arg) != TREE_CODE (parm))
16539 return unify_type_mismatch (explain_p, parm, arg);
16541 if (TYPE_PTRMEMFUNC_P (parm))
16543 if (!TYPE_PTRMEMFUNC_P (arg))
16544 return unify_type_mismatch (explain_p, parm, arg);
16546 return unify (tparms, targs,
16547 TYPE_PTRMEMFUNC_FN_TYPE (parm),
16548 TYPE_PTRMEMFUNC_FN_TYPE (arg),
16549 strict, explain_p);
16552 if (CLASSTYPE_TEMPLATE_INFO (parm))
16554 tree t = NULL_TREE;
16556 if (strict_in & UNIFY_ALLOW_DERIVED)
16558 /* First, we try to unify the PARM and ARG directly. */
16559 t = try_class_unification (tparms, targs,
16560 parm, arg, explain_p);
16564 /* Fallback to the special case allowed in
16565 [temp.deduct.call]:
16567 If P is a class, and P has the form
16568 template-id, then A can be a derived class of
16569 the deduced A. Likewise, if P is a pointer to
16570 a class of the form template-id, A can be a
16571 pointer to a derived class pointed to by the
16573 enum template_base_result r;
16574 r = get_template_base (tparms, targs, parm, arg,
16578 return unify_no_common_base (explain_p, r, parm, arg);
16581 else if (CLASSTYPE_TEMPLATE_INFO (arg)
16582 && (CLASSTYPE_TI_TEMPLATE (parm)
16583 == CLASSTYPE_TI_TEMPLATE (arg)))
16584 /* Perhaps PARM is something like S<U> and ARG is S<int>.
16585 Then, we should unify `int' and `U'. */
16588 /* There's no chance of unification succeeding. */
16589 return unify_type_mismatch (explain_p, parm, arg);
16591 return unify (tparms, targs, CLASSTYPE_TI_ARGS (parm),
16592 CLASSTYPE_TI_ARGS (t), UNIFY_ALLOW_NONE, explain_p);
16594 else if (!same_type_ignoring_top_level_qualifiers_p (parm, arg))
16595 return unify_type_mismatch (explain_p, parm, arg);
16596 return unify_success (explain_p);
16599 case FUNCTION_TYPE:
16601 unsigned int nargs;
16606 if (TREE_CODE (arg) != TREE_CODE (parm))
16607 return unify_type_mismatch (explain_p, parm, arg);
16609 /* CV qualifications for methods can never be deduced, they must
16610 match exactly. We need to check them explicitly here,
16611 because type_unification_real treats them as any other
16612 cv-qualified parameter. */
16613 if (TREE_CODE (parm) == METHOD_TYPE
16614 && (!check_cv_quals_for_unify
16616 class_of_this_parm (arg),
16617 class_of_this_parm (parm))))
16618 return unify_cv_qual_mismatch (explain_p, parm, arg);
16620 RECUR_AND_CHECK_FAILURE (tparms, targs, TREE_TYPE (parm),
16621 TREE_TYPE (arg), UNIFY_ALLOW_NONE, explain_p);
16623 nargs = list_length (TYPE_ARG_TYPES (arg));
16624 args = XALLOCAVEC (tree, nargs);
16625 for (a = TYPE_ARG_TYPES (arg), i = 0;
16626 a != NULL_TREE && a != void_list_node;
16627 a = TREE_CHAIN (a), ++i)
16628 args[i] = TREE_VALUE (a);
16631 return type_unification_real (tparms, targs, TYPE_ARG_TYPES (parm),
16632 args, nargs, 1, DEDUCE_EXACT,
16633 LOOKUP_NORMAL, explain_p);
16637 /* Unify a pointer to member with a pointer to member function, which
16638 deduces the type of the member as a function type. */
16639 if (TYPE_PTRMEMFUNC_P (arg))
16644 /* Check top-level cv qualifiers */
16645 if (!check_cv_quals_for_unify (UNIFY_ALLOW_NONE, arg, parm))
16646 return unify_cv_qual_mismatch (explain_p, parm, arg);
16648 RECUR_AND_CHECK_FAILURE (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
16649 TYPE_PTRMEMFUNC_OBJECT_TYPE (arg),
16650 UNIFY_ALLOW_NONE, explain_p);
16652 /* Determine the type of the function we are unifying against. */
16653 method_type = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (arg));
16655 build_function_type (TREE_TYPE (method_type),
16656 TREE_CHAIN (TYPE_ARG_TYPES (method_type)));
16658 /* Extract the cv-qualifiers of the member function from the
16659 implicit object parameter and place them on the function
16660 type to be restored later. */
16661 fntype = apply_memfn_quals (fntype, type_memfn_quals (method_type));
16662 return unify (tparms, targs, TREE_TYPE (parm), fntype, strict, explain_p);
16665 if (TREE_CODE (arg) != OFFSET_TYPE)
16666 return unify_type_mismatch (explain_p, parm, arg);
16667 RECUR_AND_CHECK_FAILURE (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
16668 TYPE_OFFSET_BASETYPE (arg),
16669 UNIFY_ALLOW_NONE, explain_p);
16670 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
16671 strict, explain_p);
16674 if (DECL_TEMPLATE_PARM_P (parm))
16675 return unify (tparms, targs, DECL_INITIAL (parm), arg, strict, explain_p);
16676 if (arg != integral_constant_value (parm))
16677 return unify_template_argument_mismatch (explain_p, parm, arg);
16678 return unify_success (explain_p);
16681 case TEMPLATE_DECL:
16682 /* Matched cases are handled by the ARG == PARM test above. */
16683 return unify_template_argument_mismatch (explain_p, parm, arg);
16686 /* A non-type template parameter that is a variable should be a
16687 an integral constant, in which case, it whould have been
16688 folded into its (constant) value. So we should not be getting
16689 a variable here. */
16690 gcc_unreachable ();
16692 case TYPE_ARGUMENT_PACK:
16693 case NONTYPE_ARGUMENT_PACK:
16694 return unify (tparms, targs, ARGUMENT_PACK_ARGS (parm),
16695 ARGUMENT_PACK_ARGS (arg), strict, explain_p);
16698 case DECLTYPE_TYPE:
16699 case UNDERLYING_TYPE:
16700 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
16701 or UNDERLYING_TYPE nodes. */
16702 return unify_success (explain_p);
16705 /* Unification fails if we hit an error node. */
16706 return unify_invalid (explain_p);
16709 /* An unresolved overload is a nondeduced context. */
16710 if (type_unknown_p (parm))
16711 return unify_success (explain_p);
16712 gcc_assert (EXPR_P (parm));
16714 /* We must be looking at an expression. This can happen with
16718 void foo(S<I>, S<I + 2>);
16720 This is a "nondeduced context":
16724 The nondeduced contexts are:
16726 --A type that is a template-id in which one or more of
16727 the template-arguments is an expression that references
16728 a template-parameter.
16730 In these cases, we assume deduction succeeded, but don't
16731 actually infer any unifications. */
16733 if (!uses_template_parms (parm)
16734 && !template_args_equal (parm, arg))
16735 return unify_expression_unequal (explain_p, parm, arg);
16737 return unify_success (explain_p);
16740 #undef RECUR_AND_CHECK_FAILURE
16742 /* Note that DECL can be defined in this translation unit, if
16746 mark_definable (tree decl)
16749 DECL_NOT_REALLY_EXTERN (decl) = 1;
16750 FOR_EACH_CLONE (clone, decl)
16751 DECL_NOT_REALLY_EXTERN (clone) = 1;
16754 /* Called if RESULT is explicitly instantiated, or is a member of an
16755 explicitly instantiated class. */
16758 mark_decl_instantiated (tree result, int extern_p)
16760 SET_DECL_EXPLICIT_INSTANTIATION (result);
16762 /* If this entity has already been written out, it's too late to
16763 make any modifications. */
16764 if (TREE_ASM_WRITTEN (result))
16767 if (TREE_CODE (result) != FUNCTION_DECL)
16768 /* The TREE_PUBLIC flag for function declarations will have been
16769 set correctly by tsubst. */
16770 TREE_PUBLIC (result) = 1;
16772 /* This might have been set by an earlier implicit instantiation. */
16773 DECL_COMDAT (result) = 0;
16776 DECL_NOT_REALLY_EXTERN (result) = 0;
16779 mark_definable (result);
16780 /* Always make artificials weak. */
16781 if (DECL_ARTIFICIAL (result) && flag_weak)
16782 comdat_linkage (result);
16783 /* For WIN32 we also want to put explicit instantiations in
16784 linkonce sections. */
16785 else if (TREE_PUBLIC (result))
16786 maybe_make_one_only (result);
16789 /* If EXTERN_P, then this function will not be emitted -- unless
16790 followed by an explicit instantiation, at which point its linkage
16791 will be adjusted. If !EXTERN_P, then this function will be
16792 emitted here. In neither circumstance do we want
16793 import_export_decl to adjust the linkage. */
16794 DECL_INTERFACE_KNOWN (result) = 1;
16797 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
16798 important template arguments. If any are missing, we check whether
16799 they're important by using error_mark_node for substituting into any
16800 args that were used for partial ordering (the ones between ARGS and END)
16801 and seeing if it bubbles up. */
16804 check_undeduced_parms (tree targs, tree args, tree end)
16806 bool found = false;
16808 for (i = TREE_VEC_LENGTH (targs) - 1; i >= 0; --i)
16809 if (TREE_VEC_ELT (targs, i) == NULL_TREE)
16812 TREE_VEC_ELT (targs, i) = error_mark_node;
16816 for (; args != end; args = TREE_CHAIN (args))
16818 tree substed = tsubst (TREE_VALUE (args), targs, tf_none, NULL_TREE);
16819 if (substed == error_mark_node)
16826 /* Given two function templates PAT1 and PAT2, return:
16828 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
16829 -1 if PAT2 is more specialized than PAT1.
16830 0 if neither is more specialized.
16832 LEN indicates the number of parameters we should consider
16833 (defaulted parameters should not be considered).
16835 The 1998 std underspecified function template partial ordering, and
16836 DR214 addresses the issue. We take pairs of arguments, one from
16837 each of the templates, and deduce them against each other. One of
16838 the templates will be more specialized if all the *other*
16839 template's arguments deduce against its arguments and at least one
16840 of its arguments *does* *not* deduce against the other template's
16841 corresponding argument. Deduction is done as for class templates.
16842 The arguments used in deduction have reference and top level cv
16843 qualifiers removed. Iff both arguments were originally reference
16844 types *and* deduction succeeds in both directions, the template
16845 with the more cv-qualified argument wins for that pairing (if
16846 neither is more cv-qualified, they both are equal). Unlike regular
16847 deduction, after all the arguments have been deduced in this way,
16848 we do *not* verify the deduced template argument values can be
16849 substituted into non-deduced contexts.
16851 The logic can be a bit confusing here, because we look at deduce1 and
16852 targs1 to see if pat2 is at least as specialized, and vice versa; if we
16853 can find template arguments for pat1 to make arg1 look like arg2, that
16854 means that arg2 is at least as specialized as arg1. */
16857 more_specialized_fn (tree pat1, tree pat2, int len)
16859 tree decl1 = DECL_TEMPLATE_RESULT (pat1);
16860 tree decl2 = DECL_TEMPLATE_RESULT (pat2);
16861 tree targs1 = make_tree_vec (DECL_NTPARMS (pat1));
16862 tree targs2 = make_tree_vec (DECL_NTPARMS (pat2));
16863 tree tparms1 = DECL_INNERMOST_TEMPLATE_PARMS (pat1);
16864 tree tparms2 = DECL_INNERMOST_TEMPLATE_PARMS (pat2);
16865 tree args1 = TYPE_ARG_TYPES (TREE_TYPE (decl1));
16866 tree args2 = TYPE_ARG_TYPES (TREE_TYPE (decl2));
16867 tree origs1, origs2;
16868 bool lose1 = false;
16869 bool lose2 = false;
16871 /* Remove the this parameter from non-static member functions. If
16872 one is a non-static member function and the other is not a static
16873 member function, remove the first parameter from that function
16874 also. This situation occurs for operator functions where we
16875 locate both a member function (with this pointer) and non-member
16876 operator (with explicit first operand). */
16877 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl1))
16879 len--; /* LEN is the number of significant arguments for DECL1 */
16880 args1 = TREE_CHAIN (args1);
16881 if (!DECL_STATIC_FUNCTION_P (decl2))
16882 args2 = TREE_CHAIN (args2);
16884 else if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl2))
16886 args2 = TREE_CHAIN (args2);
16887 if (!DECL_STATIC_FUNCTION_P (decl1))
16890 args1 = TREE_CHAIN (args1);
16894 /* If only one is a conversion operator, they are unordered. */
16895 if (DECL_CONV_FN_P (decl1) != DECL_CONV_FN_P (decl2))
16898 /* Consider the return type for a conversion function */
16899 if (DECL_CONV_FN_P (decl1))
16901 args1 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl1)), args1);
16902 args2 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl2)), args2);
16906 processing_template_decl++;
16912 /* Stop when an ellipsis is seen. */
16913 && args1 != NULL_TREE && args2 != NULL_TREE)
16915 tree arg1 = TREE_VALUE (args1);
16916 tree arg2 = TREE_VALUE (args2);
16917 int deduce1, deduce2;
16921 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
16922 && TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
16924 /* When both arguments are pack expansions, we need only
16925 unify the patterns themselves. */
16926 arg1 = PACK_EXPANSION_PATTERN (arg1);
16927 arg2 = PACK_EXPANSION_PATTERN (arg2);
16929 /* This is the last comparison we need to do. */
16933 if (TREE_CODE (arg1) == REFERENCE_TYPE)
16935 arg1 = TREE_TYPE (arg1);
16936 quals1 = cp_type_quals (arg1);
16939 if (TREE_CODE (arg2) == REFERENCE_TYPE)
16941 arg2 = TREE_TYPE (arg2);
16942 quals2 = cp_type_quals (arg2);
16945 if ((quals1 < 0) != (quals2 < 0))
16947 /* Only of the args is a reference, see if we should apply
16948 array/function pointer decay to it. This is not part of
16949 DR214, but is, IMHO, consistent with the deduction rules
16950 for the function call itself, and with our earlier
16951 implementation of the underspecified partial ordering
16952 rules. (nathan). */
16955 switch (TREE_CODE (arg1))
16958 arg1 = TREE_TYPE (arg1);
16960 case FUNCTION_TYPE:
16961 arg1 = build_pointer_type (arg1);
16970 switch (TREE_CODE (arg2))
16973 arg2 = TREE_TYPE (arg2);
16975 case FUNCTION_TYPE:
16976 arg2 = build_pointer_type (arg2);
16985 arg1 = TYPE_MAIN_VARIANT (arg1);
16986 arg2 = TYPE_MAIN_VARIANT (arg2);
16988 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION)
16990 int i, len2 = list_length (args2);
16991 tree parmvec = make_tree_vec (1);
16992 tree argvec = make_tree_vec (len2);
16995 /* Setup the parameter vector, which contains only ARG1. */
16996 TREE_VEC_ELT (parmvec, 0) = arg1;
16998 /* Setup the argument vector, which contains the remaining
17000 for (i = 0; i < len2; i++, ta = TREE_CHAIN (ta))
17001 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
17003 deduce1 = (unify_pack_expansion (tparms1, targs1, parmvec,
17004 argvec, DEDUCE_EXACT,
17005 /*subr=*/true, /*explain_p=*/false)
17008 /* We cannot deduce in the other direction, because ARG1 is
17009 a pack expansion but ARG2 is not. */
17012 else if (TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
17014 int i, len1 = list_length (args1);
17015 tree parmvec = make_tree_vec (1);
17016 tree argvec = make_tree_vec (len1);
17019 /* Setup the parameter vector, which contains only ARG1. */
17020 TREE_VEC_ELT (parmvec, 0) = arg2;
17022 /* Setup the argument vector, which contains the remaining
17024 for (i = 0; i < len1; i++, ta = TREE_CHAIN (ta))
17025 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
17027 deduce2 = (unify_pack_expansion (tparms2, targs2, parmvec,
17028 argvec, DEDUCE_EXACT,
17029 /*subr=*/true, /*explain_p=*/false)
17032 /* We cannot deduce in the other direction, because ARG2 is
17033 a pack expansion but ARG1 is not.*/
17039 /* The normal case, where neither argument is a pack
17041 deduce1 = (unify (tparms1, targs1, arg1, arg2,
17042 UNIFY_ALLOW_NONE, /*explain_p=*/false)
17044 deduce2 = (unify (tparms2, targs2, arg2, arg1,
17045 UNIFY_ALLOW_NONE, /*explain_p=*/false)
17049 /* If we couldn't deduce arguments for tparms1 to make arg1 match
17050 arg2, then arg2 is not as specialized as arg1. */
17056 /* "If, for a given type, deduction succeeds in both directions
17057 (i.e., the types are identical after the transformations above)
17058 and if the type from the argument template is more cv-qualified
17059 than the type from the parameter template (as described above)
17060 that type is considered to be more specialized than the other. If
17061 neither type is more cv-qualified than the other then neither type
17062 is more specialized than the other." */
17064 if (deduce1 && deduce2
17065 && quals1 != quals2 && quals1 >= 0 && quals2 >= 0)
17067 if ((quals1 & quals2) == quals2)
17069 if ((quals1 & quals2) == quals1)
17073 if (lose1 && lose2)
17074 /* We've failed to deduce something in either direction.
17075 These must be unordered. */
17078 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
17079 || TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
17080 /* We have already processed all of the arguments in our
17081 handing of the pack expansion type. */
17084 args1 = TREE_CHAIN (args1);
17085 args2 = TREE_CHAIN (args2);
17088 /* "In most cases, all template parameters must have values in order for
17089 deduction to succeed, but for partial ordering purposes a template
17090 parameter may remain without a value provided it is not used in the
17091 types being used for partial ordering."
17093 Thus, if we are missing any of the targs1 we need to substitute into
17094 origs1, then pat2 is not as specialized as pat1. This can happen when
17095 there is a nondeduced context. */
17096 if (!lose2 && check_undeduced_parms (targs1, origs1, args1))
17098 if (!lose1 && check_undeduced_parms (targs2, origs2, args2))
17101 processing_template_decl--;
17103 /* All things being equal, if the next argument is a pack expansion
17104 for one function but not for the other, prefer the
17105 non-variadic function. FIXME this is bogus; see c++/41958. */
17107 && args1 && TREE_VALUE (args1)
17108 && args2 && TREE_VALUE (args2))
17110 lose1 = TREE_CODE (TREE_VALUE (args1)) == TYPE_PACK_EXPANSION;
17111 lose2 = TREE_CODE (TREE_VALUE (args2)) == TYPE_PACK_EXPANSION;
17114 if (lose1 == lose2)
17122 /* Determine which of two partial specializations is more specialized.
17124 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
17125 to the first partial specialization. The TREE_VALUE is the
17126 innermost set of template parameters for the partial
17127 specialization. PAT2 is similar, but for the second template.
17129 Return 1 if the first partial specialization is more specialized;
17130 -1 if the second is more specialized; 0 if neither is more
17133 See [temp.class.order] for information about determining which of
17134 two templates is more specialized. */
17137 more_specialized_class (tree pat1, tree pat2)
17142 bool any_deductions = false;
17144 tmpl1 = TREE_TYPE (pat1);
17145 tmpl2 = TREE_TYPE (pat2);
17147 /* Just like what happens for functions, if we are ordering between
17148 different class template specializations, we may encounter dependent
17149 types in the arguments, and we need our dependency check functions
17150 to behave correctly. */
17151 ++processing_template_decl;
17152 targs = get_class_bindings (TREE_VALUE (pat1),
17153 CLASSTYPE_TI_ARGS (tmpl1),
17154 CLASSTYPE_TI_ARGS (tmpl2));
17158 any_deductions = true;
17161 targs = get_class_bindings (TREE_VALUE (pat2),
17162 CLASSTYPE_TI_ARGS (tmpl2),
17163 CLASSTYPE_TI_ARGS (tmpl1));
17167 any_deductions = true;
17169 --processing_template_decl;
17171 /* In the case of a tie where at least one of the class templates
17172 has a parameter pack at the end, the template with the most
17173 non-packed parameters wins. */
17176 && (template_args_variadic_p (TREE_PURPOSE (pat1))
17177 || template_args_variadic_p (TREE_PURPOSE (pat2))))
17179 tree args1 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat1));
17180 tree args2 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat2));
17181 int len1 = TREE_VEC_LENGTH (args1);
17182 int len2 = TREE_VEC_LENGTH (args2);
17184 /* We don't count the pack expansion at the end. */
17185 if (template_args_variadic_p (TREE_PURPOSE (pat1)))
17187 if (template_args_variadic_p (TREE_PURPOSE (pat2)))
17192 else if (len1 < len2)
17199 /* Return the template arguments that will produce the function signature
17200 DECL from the function template FN, with the explicit template
17201 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
17202 also match. Return NULL_TREE if no satisfactory arguments could be
17206 get_bindings (tree fn, tree decl, tree explicit_args, bool check_rettype)
17208 int ntparms = DECL_NTPARMS (fn);
17209 tree targs = make_tree_vec (ntparms);
17211 tree decl_arg_types;
17213 unsigned int nargs, ix;
17216 /* Substitute the explicit template arguments into the type of DECL.
17217 The call to fn_type_unification will handle substitution into the
17219 decl_type = TREE_TYPE (decl);
17220 if (explicit_args && uses_template_parms (decl_type))
17223 tree converted_args;
17225 if (DECL_TEMPLATE_INFO (decl))
17226 tmpl = DECL_TI_TEMPLATE (decl);
17228 /* We can get here for some invalid specializations. */
17232 = coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
17233 explicit_args, NULL_TREE,
17235 /*require_all_args=*/false,
17236 /*use_default_args=*/false);
17237 if (converted_args == error_mark_node)
17240 decl_type = tsubst (decl_type, converted_args, tf_none, NULL_TREE);
17241 if (decl_type == error_mark_node)
17245 /* Never do unification on the 'this' parameter. */
17246 decl_arg_types = skip_artificial_parms_for (decl,
17247 TYPE_ARG_TYPES (decl_type));
17249 nargs = list_length (decl_arg_types);
17250 args = XALLOCAVEC (tree, nargs);
17251 for (arg = decl_arg_types, ix = 0;
17252 arg != NULL_TREE && arg != void_list_node;
17253 arg = TREE_CHAIN (arg), ++ix)
17254 args[ix] = TREE_VALUE (arg);
17256 if (fn_type_unification (fn, explicit_args, targs,
17258 (check_rettype || DECL_CONV_FN_P (fn)
17259 ? TREE_TYPE (decl_type) : NULL_TREE),
17260 DEDUCE_EXACT, LOOKUP_NORMAL, /*explain_p=*/false))
17266 /* Return the innermost template arguments that, when applied to a
17267 template specialization whose innermost template parameters are
17268 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
17271 For example, suppose we have:
17273 template <class T, class U> struct S {};
17274 template <class T> struct S<T*, int> {};
17276 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
17277 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
17278 int}. The resulting vector will be {double}, indicating that `T'
17279 is bound to `double'. */
17282 get_class_bindings (tree tparms, tree spec_args, tree args)
17284 int i, ntparms = TREE_VEC_LENGTH (tparms);
17286 tree innermost_deduced_args;
17288 innermost_deduced_args = make_tree_vec (ntparms);
17289 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
17291 deduced_args = copy_node (args);
17292 SET_TMPL_ARGS_LEVEL (deduced_args,
17293 TMPL_ARGS_DEPTH (deduced_args),
17294 innermost_deduced_args);
17297 deduced_args = innermost_deduced_args;
17299 if (unify (tparms, deduced_args,
17300 INNERMOST_TEMPLATE_ARGS (spec_args),
17301 INNERMOST_TEMPLATE_ARGS (args),
17302 UNIFY_ALLOW_NONE, /*explain_p=*/false))
17305 for (i = 0; i < ntparms; ++i)
17306 if (! TREE_VEC_ELT (innermost_deduced_args, i))
17309 /* Verify that nondeduced template arguments agree with the type
17310 obtained from argument deduction.
17314 struct A { typedef int X; };
17315 template <class T, class U> struct C {};
17316 template <class T> struct C<T, typename T::X> {};
17318 Then with the instantiation `C<A, int>', we can deduce that
17319 `T' is `A' but unify () does not check whether `typename T::X'
17321 spec_args = tsubst (spec_args, deduced_args, tf_none, NULL_TREE);
17322 if (spec_args == error_mark_node
17323 /* We only need to check the innermost arguments; the other
17324 arguments will always agree. */
17325 || !comp_template_args (INNERMOST_TEMPLATE_ARGS (spec_args),
17326 INNERMOST_TEMPLATE_ARGS (args)))
17329 /* Now that we have bindings for all of the template arguments,
17330 ensure that the arguments deduced for the template template
17331 parameters have compatible template parameter lists. See the use
17332 of template_template_parm_bindings_ok_p in fn_type_unification
17333 for more information. */
17334 if (!template_template_parm_bindings_ok_p (tparms, deduced_args))
17337 return deduced_args;
17340 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
17341 Return the TREE_LIST node with the most specialized template, if
17342 any. If there is no most specialized template, the error_mark_node
17345 Note that this function does not look at, or modify, the
17346 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
17347 returned is one of the elements of INSTANTIATIONS, callers may
17348 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
17349 and retrieve it from the value returned. */
17352 most_specialized_instantiation (tree templates)
17356 ++processing_template_decl;
17359 for (fn = TREE_CHAIN (templates); fn; fn = TREE_CHAIN (fn))
17363 if (get_bindings (TREE_VALUE (champ),
17364 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
17365 NULL_TREE, /*check_ret=*/true))
17368 if (get_bindings (TREE_VALUE (fn),
17369 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
17370 NULL_TREE, /*check_ret=*/true))
17377 /* Equally specialized, move to next function. If there
17378 is no next function, nothing's most specialized. */
17379 fn = TREE_CHAIN (fn);
17387 /* Now verify that champ is better than everything earlier in the
17388 instantiation list. */
17389 for (fn = templates; fn != champ; fn = TREE_CHAIN (fn))
17390 if (get_bindings (TREE_VALUE (champ),
17391 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
17392 NULL_TREE, /*check_ret=*/true)
17393 || !get_bindings (TREE_VALUE (fn),
17394 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
17395 NULL_TREE, /*check_ret=*/true))
17401 processing_template_decl--;
17404 return error_mark_node;
17409 /* If DECL is a specialization of some template, return the most
17410 general such template. Otherwise, returns NULL_TREE.
17412 For example, given:
17414 template <class T> struct S { template <class U> void f(U); };
17416 if TMPL is `template <class U> void S<int>::f(U)' this will return
17417 the full template. This function will not trace past partial
17418 specializations, however. For example, given in addition:
17420 template <class T> struct S<T*> { template <class U> void f(U); };
17422 if TMPL is `template <class U> void S<int*>::f(U)' this will return
17423 `template <class T> template <class U> S<T*>::f(U)'. */
17426 most_general_template (tree decl)
17428 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
17429 an immediate specialization. */
17430 if (TREE_CODE (decl) == FUNCTION_DECL)
17432 if (DECL_TEMPLATE_INFO (decl)) {
17433 decl = DECL_TI_TEMPLATE (decl);
17435 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
17436 template friend. */
17437 if (TREE_CODE (decl) != TEMPLATE_DECL)
17443 /* Look for more and more general templates. */
17444 while (DECL_TEMPLATE_INFO (decl))
17446 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
17447 (See cp-tree.h for details.) */
17448 if (TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
17451 if (CLASS_TYPE_P (TREE_TYPE (decl))
17452 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)))
17455 /* Stop if we run into an explicitly specialized class template. */
17456 if (!DECL_NAMESPACE_SCOPE_P (decl)
17457 && DECL_CONTEXT (decl)
17458 && CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (decl)))
17461 decl = DECL_TI_TEMPLATE (decl);
17467 /* Return the most specialized of the class template partial
17468 specializations of TMPL which can produce TYPE, a specialization of
17469 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
17470 a _TYPE node corresponding to the partial specialization, while the
17471 TREE_PURPOSE is the set of template arguments that must be
17472 substituted into the TREE_TYPE in order to generate TYPE.
17474 If the choice of partial specialization is ambiguous, a diagnostic
17475 is issued, and the error_mark_node is returned. If there are no
17476 partial specializations of TMPL matching TYPE, then NULL_TREE is
17480 most_specialized_class (tree type, tree tmpl, tsubst_flags_t complain)
17482 tree list = NULL_TREE;
17488 tree outer_args = NULL_TREE;
17490 tmpl = most_general_template (tmpl);
17491 args = CLASSTYPE_TI_ARGS (type);
17493 /* For determining which partial specialization to use, only the
17494 innermost args are interesting. */
17495 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
17497 outer_args = strip_innermost_template_args (args, 1);
17498 args = INNERMOST_TEMPLATE_ARGS (args);
17501 for (t = DECL_TEMPLATE_SPECIALIZATIONS (tmpl); t; t = TREE_CHAIN (t))
17503 tree partial_spec_args;
17505 tree parms = TREE_VALUE (t);
17507 partial_spec_args = CLASSTYPE_TI_ARGS (TREE_TYPE (t));
17509 ++processing_template_decl;
17515 /* Discard the outer levels of args, and then substitute in the
17516 template args from the enclosing class. */
17517 partial_spec_args = INNERMOST_TEMPLATE_ARGS (partial_spec_args);
17518 partial_spec_args = tsubst_template_args
17519 (partial_spec_args, outer_args, tf_none, NULL_TREE);
17521 /* PARMS already refers to just the innermost parms, but the
17522 template parms in partial_spec_args had their levels lowered
17523 by tsubst, so we need to do the same for the parm list. We
17524 can't just tsubst the TREE_VEC itself, as tsubst wants to
17525 treat a TREE_VEC as an argument vector. */
17526 parms = copy_node (parms);
17527 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
17528 TREE_VEC_ELT (parms, i) =
17529 tsubst (TREE_VEC_ELT (parms, i), outer_args, tf_none, NULL_TREE);
17533 partial_spec_args =
17534 coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
17535 add_to_template_args (outer_args,
17536 partial_spec_args),
17538 /*require_all_args=*/true,
17539 /*use_default_args=*/true);
17541 --processing_template_decl;
17543 if (partial_spec_args == error_mark_node)
17544 return error_mark_node;
17546 spec_args = get_class_bindings (parms,
17552 spec_args = add_to_template_args (outer_args, spec_args);
17553 list = tree_cons (spec_args, TREE_VALUE (t), list);
17554 TREE_TYPE (list) = TREE_TYPE (t);
17561 ambiguous_p = false;
17564 t = TREE_CHAIN (t);
17565 for (; t; t = TREE_CHAIN (t))
17567 fate = more_specialized_class (champ, t);
17574 t = TREE_CHAIN (t);
17577 ambiguous_p = true;
17586 for (t = list; t && t != champ; t = TREE_CHAIN (t))
17588 fate = more_specialized_class (champ, t);
17591 ambiguous_p = true;
17599 char *spaces = NULL;
17600 if (!(complain & tf_error))
17601 return error_mark_node;
17602 error ("ambiguous class template instantiation for %q#T", type);
17603 str = ngettext ("candidate is:", "candidates are:", list_length (list));
17604 for (t = list; t; t = TREE_CHAIN (t))
17606 error ("%s %+#T", spaces ? spaces : str, TREE_TYPE (t));
17607 spaces = spaces ? spaces : get_spaces (str);
17610 return error_mark_node;
17616 /* Explicitly instantiate DECL. */
17619 do_decl_instantiation (tree decl, tree storage)
17621 tree result = NULL_TREE;
17624 if (!decl || decl == error_mark_node)
17625 /* An error occurred, for which grokdeclarator has already issued
17626 an appropriate message. */
17628 else if (! DECL_LANG_SPECIFIC (decl))
17630 error ("explicit instantiation of non-template %q#D", decl);
17633 else if (TREE_CODE (decl) == VAR_DECL)
17635 /* There is an asymmetry here in the way VAR_DECLs and
17636 FUNCTION_DECLs are handled by grokdeclarator. In the case of
17637 the latter, the DECL we get back will be marked as a
17638 template instantiation, and the appropriate
17639 DECL_TEMPLATE_INFO will be set up. This does not happen for
17640 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
17641 should handle VAR_DECLs as it currently handles
17643 if (!DECL_CLASS_SCOPE_P (decl))
17645 error ("%qD is not a static data member of a class template", decl);
17648 result = lookup_field (DECL_CONTEXT (decl), DECL_NAME (decl), 0, false);
17649 if (!result || TREE_CODE (result) != VAR_DECL)
17651 error ("no matching template for %qD found", decl);
17654 if (!same_type_p (TREE_TYPE (result), TREE_TYPE (decl)))
17656 error ("type %qT for explicit instantiation %qD does not match "
17657 "declared type %qT", TREE_TYPE (result), decl,
17662 else if (TREE_CODE (decl) != FUNCTION_DECL)
17664 error ("explicit instantiation of %q#D", decl);
17670 /* Check for various error cases. Note that if the explicit
17671 instantiation is valid the RESULT will currently be marked as an
17672 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
17673 until we get here. */
17675 if (DECL_TEMPLATE_SPECIALIZATION (result))
17677 /* DR 259 [temp.spec].
17679 Both an explicit instantiation and a declaration of an explicit
17680 specialization shall not appear in a program unless the explicit
17681 instantiation follows a declaration of the explicit specialization.
17683 For a given set of template parameters, if an explicit
17684 instantiation of a template appears after a declaration of an
17685 explicit specialization for that template, the explicit
17686 instantiation has no effect. */
17689 else if (DECL_EXPLICIT_INSTANTIATION (result))
17693 No program shall explicitly instantiate any template more
17696 We check DECL_NOT_REALLY_EXTERN so as not to complain when
17697 the first instantiation was `extern' and the second is not,
17698 and EXTERN_P for the opposite case. */
17699 if (DECL_NOT_REALLY_EXTERN (result) && !extern_p)
17700 permerror (input_location, "duplicate explicit instantiation of %q#D", result);
17701 /* If an "extern" explicit instantiation follows an ordinary
17702 explicit instantiation, the template is instantiated. */
17706 else if (!DECL_IMPLICIT_INSTANTIATION (result))
17708 error ("no matching template for %qD found", result);
17711 else if (!DECL_TEMPLATE_INFO (result))
17713 permerror (input_location, "explicit instantiation of non-template %q#D", result);
17717 if (storage == NULL_TREE)
17719 else if (storage == ridpointers[(int) RID_EXTERN])
17721 if (!in_system_header && (cxx_dialect == cxx98))
17722 pedwarn (input_location, OPT_pedantic,
17723 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
17728 error ("storage class %qD applied to template instantiation", storage);
17730 check_explicit_instantiation_namespace (result);
17731 mark_decl_instantiated (result, extern_p);
17733 instantiate_decl (result, /*defer_ok=*/1,
17734 /*expl_inst_class_mem_p=*/false);
17738 mark_class_instantiated (tree t, int extern_p)
17740 SET_CLASSTYPE_EXPLICIT_INSTANTIATION (t);
17741 SET_CLASSTYPE_INTERFACE_KNOWN (t);
17742 CLASSTYPE_INTERFACE_ONLY (t) = extern_p;
17743 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (t)) = extern_p;
17746 CLASSTYPE_DEBUG_REQUESTED (t) = 1;
17747 rest_of_type_compilation (t, 1);
17751 /* Called from do_type_instantiation through binding_table_foreach to
17752 do recursive instantiation for the type bound in ENTRY. */
17754 bt_instantiate_type_proc (binding_entry entry, void *data)
17756 tree storage = *(tree *) data;
17758 if (MAYBE_CLASS_TYPE_P (entry->type)
17759 && !uses_template_parms (CLASSTYPE_TI_ARGS (entry->type)))
17760 do_type_instantiation (TYPE_MAIN_DECL (entry->type), storage, 0);
17763 /* Called from do_type_instantiation to instantiate a member
17764 (a member function or a static member variable) of an
17765 explicitly instantiated class template. */
17767 instantiate_class_member (tree decl, int extern_p)
17769 mark_decl_instantiated (decl, extern_p);
17771 instantiate_decl (decl, /*defer_ok=*/1,
17772 /*expl_inst_class_mem_p=*/true);
17775 /* Perform an explicit instantiation of template class T. STORAGE, if
17776 non-null, is the RID for extern, inline or static. COMPLAIN is
17777 nonzero if this is called from the parser, zero if called recursively,
17778 since the standard is unclear (as detailed below). */
17781 do_type_instantiation (tree t, tree storage, tsubst_flags_t complain)
17786 int previous_instantiation_extern_p = 0;
17788 if (TREE_CODE (t) == TYPE_DECL)
17791 if (! CLASS_TYPE_P (t) || ! CLASSTYPE_TEMPLATE_INFO (t))
17794 (TYPE_TEMPLATE_INFO (t)) ? TYPE_TI_TEMPLATE (t) : NULL;
17796 error ("explicit instantiation of non-class template %qD", tmpl);
17798 error ("explicit instantiation of non-template type %qT", t);
17804 if (!COMPLETE_TYPE_P (t))
17806 if (complain & tf_error)
17807 error ("explicit instantiation of %q#T before definition of template",
17812 if (storage != NULL_TREE)
17814 if (!in_system_header)
17816 if (storage == ridpointers[(int) RID_EXTERN])
17818 if (cxx_dialect == cxx98)
17819 pedwarn (input_location, OPT_pedantic,
17820 "ISO C++ 1998 forbids the use of %<extern%> on "
17821 "explicit instantiations");
17824 pedwarn (input_location, OPT_pedantic,
17825 "ISO C++ forbids the use of %qE"
17826 " on explicit instantiations", storage);
17829 if (storage == ridpointers[(int) RID_INLINE])
17831 else if (storage == ridpointers[(int) RID_EXTERN])
17833 else if (storage == ridpointers[(int) RID_STATIC])
17837 error ("storage class %qD applied to template instantiation",
17843 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (t))
17845 /* DR 259 [temp.spec].
17847 Both an explicit instantiation and a declaration of an explicit
17848 specialization shall not appear in a program unless the explicit
17849 instantiation follows a declaration of the explicit specialization.
17851 For a given set of template parameters, if an explicit
17852 instantiation of a template appears after a declaration of an
17853 explicit specialization for that template, the explicit
17854 instantiation has no effect. */
17857 else if (CLASSTYPE_EXPLICIT_INSTANTIATION (t))
17861 No program shall explicitly instantiate any template more
17864 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
17865 instantiation was `extern'. If EXTERN_P then the second is.
17866 These cases are OK. */
17867 previous_instantiation_extern_p = CLASSTYPE_INTERFACE_ONLY (t);
17869 if (!previous_instantiation_extern_p && !extern_p
17870 && (complain & tf_error))
17871 permerror (input_location, "duplicate explicit instantiation of %q#T", t);
17873 /* If we've already instantiated the template, just return now. */
17874 if (!CLASSTYPE_INTERFACE_ONLY (t))
17878 check_explicit_instantiation_namespace (TYPE_NAME (t));
17879 mark_class_instantiated (t, extern_p);
17887 /* In contrast to implicit instantiation, where only the
17888 declarations, and not the definitions, of members are
17889 instantiated, we have here:
17893 The explicit instantiation of a class template specialization
17894 implies the instantiation of all of its members not
17895 previously explicitly specialized in the translation unit
17896 containing the explicit instantiation.
17898 Of course, we can't instantiate member template classes, since
17899 we don't have any arguments for them. Note that the standard
17900 is unclear on whether the instantiation of the members are
17901 *explicit* instantiations or not. However, the most natural
17902 interpretation is that it should be an explicit instantiation. */
17905 for (tmp = TYPE_METHODS (t); tmp; tmp = DECL_CHAIN (tmp))
17906 if (TREE_CODE (tmp) == FUNCTION_DECL
17907 && DECL_TEMPLATE_INSTANTIATION (tmp))
17908 instantiate_class_member (tmp, extern_p);
17910 for (tmp = TYPE_FIELDS (t); tmp; tmp = DECL_CHAIN (tmp))
17911 if (TREE_CODE (tmp) == VAR_DECL && DECL_TEMPLATE_INSTANTIATION (tmp))
17912 instantiate_class_member (tmp, extern_p);
17914 if (CLASSTYPE_NESTED_UTDS (t))
17915 binding_table_foreach (CLASSTYPE_NESTED_UTDS (t),
17916 bt_instantiate_type_proc, &storage);
17920 /* Given a function DECL, which is a specialization of TMPL, modify
17921 DECL to be a re-instantiation of TMPL with the same template
17922 arguments. TMPL should be the template into which tsubst'ing
17923 should occur for DECL, not the most general template.
17925 One reason for doing this is a scenario like this:
17928 void f(const T&, int i);
17930 void g() { f(3, 7); }
17933 void f(const T& t, const int i) { }
17935 Note that when the template is first instantiated, with
17936 instantiate_template, the resulting DECL will have no name for the
17937 first parameter, and the wrong type for the second. So, when we go
17938 to instantiate the DECL, we regenerate it. */
17941 regenerate_decl_from_template (tree decl, tree tmpl)
17943 /* The arguments used to instantiate DECL, from the most general
17948 args = DECL_TI_ARGS (decl);
17949 code_pattern = DECL_TEMPLATE_RESULT (tmpl);
17951 /* Make sure that we can see identifiers, and compute access
17953 push_access_scope (decl);
17955 if (TREE_CODE (decl) == FUNCTION_DECL)
17963 args_depth = TMPL_ARGS_DEPTH (args);
17964 parms_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
17965 if (args_depth > parms_depth)
17966 args = get_innermost_template_args (args, parms_depth);
17968 specs = tsubst_exception_specification (TREE_TYPE (code_pattern),
17969 args, tf_error, NULL_TREE,
17970 /*defer_ok*/false);
17971 if (specs && specs != error_mark_node)
17972 TREE_TYPE (decl) = build_exception_variant (TREE_TYPE (decl),
17975 /* Merge parameter declarations. */
17976 decl_parm = skip_artificial_parms_for (decl,
17977 DECL_ARGUMENTS (decl));
17979 = skip_artificial_parms_for (code_pattern,
17980 DECL_ARGUMENTS (code_pattern));
17981 while (decl_parm && !FUNCTION_PARAMETER_PACK_P (pattern_parm))
17986 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
17987 DECL_NAME (decl_parm) = DECL_NAME (pattern_parm);
17988 parm_type = tsubst (TREE_TYPE (pattern_parm), args, tf_error,
17990 parm_type = type_decays_to (parm_type);
17991 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
17992 TREE_TYPE (decl_parm) = parm_type;
17993 attributes = DECL_ATTRIBUTES (pattern_parm);
17994 if (DECL_ATTRIBUTES (decl_parm) != attributes)
17996 DECL_ATTRIBUTES (decl_parm) = attributes;
17997 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
17999 decl_parm = DECL_CHAIN (decl_parm);
18000 pattern_parm = DECL_CHAIN (pattern_parm);
18002 /* Merge any parameters that match with the function parameter
18004 if (pattern_parm && FUNCTION_PARAMETER_PACK_P (pattern_parm))
18007 tree expanded_types;
18008 /* Expand the TYPE_PACK_EXPANSION that provides the types for
18009 the parameters in this function parameter pack. */
18010 expanded_types = tsubst_pack_expansion (TREE_TYPE (pattern_parm),
18011 args, tf_error, NULL_TREE);
18012 len = TREE_VEC_LENGTH (expanded_types);
18013 for (i = 0; i < len; i++)
18018 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
18019 /* Rename the parameter to include the index. */
18020 DECL_NAME (decl_parm) =
18021 make_ith_pack_parameter_name (DECL_NAME (pattern_parm), i);
18022 parm_type = TREE_VEC_ELT (expanded_types, i);
18023 parm_type = type_decays_to (parm_type);
18024 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
18025 TREE_TYPE (decl_parm) = parm_type;
18026 attributes = DECL_ATTRIBUTES (pattern_parm);
18027 if (DECL_ATTRIBUTES (decl_parm) != attributes)
18029 DECL_ATTRIBUTES (decl_parm) = attributes;
18030 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
18032 decl_parm = DECL_CHAIN (decl_parm);
18035 /* Merge additional specifiers from the CODE_PATTERN. */
18036 if (DECL_DECLARED_INLINE_P (code_pattern)
18037 && !DECL_DECLARED_INLINE_P (decl))
18038 DECL_DECLARED_INLINE_P (decl) = 1;
18040 else if (TREE_CODE (decl) == VAR_DECL)
18042 DECL_INITIAL (decl) =
18043 tsubst_expr (DECL_INITIAL (code_pattern), args,
18044 tf_error, DECL_TI_TEMPLATE (decl),
18045 /*integral_constant_expression_p=*/false);
18046 if (VAR_HAD_UNKNOWN_BOUND (decl))
18047 TREE_TYPE (decl) = tsubst (TREE_TYPE (code_pattern), args,
18048 tf_error, DECL_TI_TEMPLATE (decl));
18051 gcc_unreachable ();
18053 pop_access_scope (decl);
18056 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
18057 substituted to get DECL. */
18060 template_for_substitution (tree decl)
18062 tree tmpl = DECL_TI_TEMPLATE (decl);
18064 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
18065 for the instantiation. This is not always the most general
18066 template. Consider, for example:
18069 struct S { template <class U> void f();
18070 template <> void f<int>(); };
18072 and an instantiation of S<double>::f<int>. We want TD to be the
18073 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
18074 while (/* An instantiation cannot have a definition, so we need a
18075 more general template. */
18076 DECL_TEMPLATE_INSTANTIATION (tmpl)
18077 /* We must also deal with friend templates. Given:
18079 template <class T> struct S {
18080 template <class U> friend void f() {};
18083 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
18084 so far as the language is concerned, but that's still
18085 where we get the pattern for the instantiation from. On
18086 other hand, if the definition comes outside the class, say:
18088 template <class T> struct S {
18089 template <class U> friend void f();
18091 template <class U> friend void f() {}
18093 we don't need to look any further. That's what the check for
18094 DECL_INITIAL is for. */
18095 || (TREE_CODE (decl) == FUNCTION_DECL
18096 && DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION (tmpl)
18097 && !DECL_INITIAL (DECL_TEMPLATE_RESULT (tmpl))))
18099 /* The present template, TD, should not be a definition. If it
18100 were a definition, we should be using it! Note that we
18101 cannot restructure the loop to just keep going until we find
18102 a template with a definition, since that might go too far if
18103 a specialization was declared, but not defined. */
18104 gcc_assert (TREE_CODE (decl) != VAR_DECL
18105 || DECL_IN_AGGR_P (DECL_TEMPLATE_RESULT (tmpl)));
18107 /* Fetch the more general template. */
18108 tmpl = DECL_TI_TEMPLATE (tmpl);
18114 /* Returns true if we need to instantiate this template instance even if we
18115 know we aren't going to emit it.. */
18118 always_instantiate_p (tree decl)
18120 /* We always instantiate inline functions so that we can inline them. An
18121 explicit instantiation declaration prohibits implicit instantiation of
18122 non-inline functions. With high levels of optimization, we would
18123 normally inline non-inline functions -- but we're not allowed to do
18124 that for "extern template" functions. Therefore, we check
18125 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
18126 return ((TREE_CODE (decl) == FUNCTION_DECL
18127 && DECL_DECLARED_INLINE_P (decl))
18128 /* And we need to instantiate static data members so that
18129 their initializers are available in integral constant
18131 || (TREE_CODE (decl) == VAR_DECL
18132 && decl_maybe_constant_var_p (decl)));
18135 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
18136 instantiate it now, modifying TREE_TYPE (fn). */
18139 maybe_instantiate_noexcept (tree fn)
18141 tree fntype, spec, noex, clone;
18143 if (DECL_CLONED_FUNCTION_P (fn))
18144 fn = DECL_CLONED_FUNCTION (fn);
18145 fntype = TREE_TYPE (fn);
18146 spec = TYPE_RAISES_EXCEPTIONS (fntype);
18148 if (!DEFERRED_NOEXCEPT_SPEC_P (spec))
18151 noex = TREE_PURPOSE (spec);
18153 if (TREE_CODE (noex) == DEFERRED_NOEXCEPT)
18155 push_tinst_level (fn);
18156 push_access_scope (fn);
18157 input_location = DECL_SOURCE_LOCATION (fn);
18158 noex = tsubst_copy_and_build (DEFERRED_NOEXCEPT_PATTERN (noex),
18159 DEFERRED_NOEXCEPT_ARGS (noex),
18160 tf_warning_or_error, fn, /*function_p=*/false,
18161 /*integral_constant_expression_p=*/true);
18162 pop_access_scope (fn);
18163 pop_tinst_level ();
18164 spec = build_noexcept_spec (noex, tf_warning_or_error);
18165 if (spec == error_mark_node)
18166 spec = noexcept_false_spec;
18170 /* This is an implicitly declared function, so NOEX is a list of
18171 other functions to evaluate and merge. */
18173 spec = noexcept_true_spec;
18174 for (elt = noex; elt; elt = OVL_NEXT (elt))
18176 tree fn = OVL_CURRENT (elt);
18178 maybe_instantiate_noexcept (fn);
18179 subspec = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (fn));
18180 spec = merge_exception_specifiers (spec, subspec, NULL_TREE);
18184 TREE_TYPE (fn) = build_exception_variant (fntype, spec);
18186 FOR_EACH_CLONE (clone, fn)
18188 if (TREE_TYPE (clone) == fntype)
18189 TREE_TYPE (clone) = TREE_TYPE (fn);
18191 TREE_TYPE (clone) = build_exception_variant (TREE_TYPE (clone), spec);
18195 /* Produce the definition of D, a _DECL generated from a template. If
18196 DEFER_OK is nonzero, then we don't have to actually do the
18197 instantiation now; we just have to do it sometime. Normally it is
18198 an error if this is an explicit instantiation but D is undefined.
18199 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
18200 explicitly instantiated class template. */
18203 instantiate_decl (tree d, int defer_ok,
18204 bool expl_inst_class_mem_p)
18206 tree tmpl = DECL_TI_TEMPLATE (d);
18213 bool pattern_defined;
18215 location_t saved_loc = input_location;
18218 /* This function should only be used to instantiate templates for
18219 functions and static member variables. */
18220 gcc_assert (TREE_CODE (d) == FUNCTION_DECL
18221 || TREE_CODE (d) == VAR_DECL);
18223 /* Variables are never deferred; if instantiation is required, they
18224 are instantiated right away. That allows for better code in the
18225 case that an expression refers to the value of the variable --
18226 if the variable has a constant value the referring expression can
18227 take advantage of that fact. */
18228 if (TREE_CODE (d) == VAR_DECL
18229 || DECL_DECLARED_CONSTEXPR_P (d))
18232 /* Don't instantiate cloned functions. Instead, instantiate the
18233 functions they cloned. */
18234 if (TREE_CODE (d) == FUNCTION_DECL && DECL_CLONED_FUNCTION_P (d))
18235 d = DECL_CLONED_FUNCTION (d);
18237 if (DECL_TEMPLATE_INSTANTIATED (d)
18238 || (TREE_CODE (d) == FUNCTION_DECL
18239 && DECL_DEFAULTED_FN (d) && DECL_INITIAL (d))
18240 || DECL_TEMPLATE_SPECIALIZATION (d))
18241 /* D has already been instantiated or explicitly specialized, so
18242 there's nothing for us to do here.
18244 It might seem reasonable to check whether or not D is an explicit
18245 instantiation, and, if so, stop here. But when an explicit
18246 instantiation is deferred until the end of the compilation,
18247 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
18248 the instantiation. */
18251 /* Check to see whether we know that this template will be
18252 instantiated in some other file, as with "extern template"
18254 external_p = (DECL_INTERFACE_KNOWN (d) && DECL_REALLY_EXTERN (d));
18256 /* In general, we do not instantiate such templates. */
18257 if (external_p && !always_instantiate_p (d))
18260 gen_tmpl = most_general_template (tmpl);
18261 gen_args = DECL_TI_ARGS (d);
18263 if (tmpl != gen_tmpl)
18264 /* We should already have the extra args. */
18265 gcc_assert (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (gen_tmpl))
18266 == TMPL_ARGS_DEPTH (gen_args));
18267 /* And what's in the hash table should match D. */
18268 gcc_assert ((spec = retrieve_specialization (gen_tmpl, gen_args, 0)) == d
18269 || spec == NULL_TREE);
18271 /* This needs to happen before any tsubsting. */
18272 if (! push_tinst_level (d))
18275 timevar_push (TV_TEMPLATE_INST);
18277 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
18278 for the instantiation. */
18279 td = template_for_substitution (d);
18280 code_pattern = DECL_TEMPLATE_RESULT (td);
18282 /* We should never be trying to instantiate a member of a class
18283 template or partial specialization. */
18284 gcc_assert (d != code_pattern);
18286 if ((DECL_NAMESPACE_SCOPE_P (d) && !DECL_INITIALIZED_IN_CLASS_P (d))
18287 || DECL_TEMPLATE_SPECIALIZATION (td))
18288 /* In the case of a friend template whose definition is provided
18289 outside the class, we may have too many arguments. Drop the
18290 ones we don't need. The same is true for specializations. */
18291 args = get_innermost_template_args
18292 (gen_args, TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (td)));
18296 if (TREE_CODE (d) == FUNCTION_DECL)
18297 pattern_defined = (DECL_SAVED_TREE (code_pattern) != NULL_TREE
18298 || DECL_DEFAULTED_OUTSIDE_CLASS_P (code_pattern));
18300 pattern_defined = ! DECL_IN_AGGR_P (code_pattern);
18302 /* We may be in the middle of deferred access check. Disable it now. */
18303 push_deferring_access_checks (dk_no_deferred);
18305 /* Unless an explicit instantiation directive has already determined
18306 the linkage of D, remember that a definition is available for
18308 if (pattern_defined
18309 && !DECL_INTERFACE_KNOWN (d)
18310 && !DECL_NOT_REALLY_EXTERN (d))
18311 mark_definable (d);
18313 DECL_SOURCE_LOCATION (td) = DECL_SOURCE_LOCATION (code_pattern);
18314 DECL_SOURCE_LOCATION (d) = DECL_SOURCE_LOCATION (code_pattern);
18315 input_location = DECL_SOURCE_LOCATION (d);
18317 /* If D is a member of an explicitly instantiated class template,
18318 and no definition is available, treat it like an implicit
18320 if (!pattern_defined && expl_inst_class_mem_p
18321 && DECL_EXPLICIT_INSTANTIATION (d))
18323 /* Leave linkage flags alone on instantiations with anonymous
18325 if (TREE_PUBLIC (d))
18327 DECL_NOT_REALLY_EXTERN (d) = 0;
18328 DECL_INTERFACE_KNOWN (d) = 0;
18330 SET_DECL_IMPLICIT_INSTANTIATION (d);
18333 if (TREE_CODE (d) == FUNCTION_DECL)
18334 maybe_instantiate_noexcept (d);
18336 /* Recheck the substitutions to obtain any warning messages
18337 about ignoring cv qualifiers. Don't do this for artificial decls,
18338 as it breaks the context-sensitive substitution for lambda op(). */
18339 if (!defer_ok && !DECL_ARTIFICIAL (d))
18341 tree gen = DECL_TEMPLATE_RESULT (gen_tmpl);
18342 tree type = TREE_TYPE (gen);
18344 /* Make sure that we can see identifiers, and compute access
18345 correctly. D is already the target FUNCTION_DECL with the
18347 push_access_scope (d);
18349 if (TREE_CODE (gen) == FUNCTION_DECL)
18351 tsubst (DECL_ARGUMENTS (gen), gen_args, tf_warning_or_error, d);
18352 tsubst_exception_specification (type, gen_args, tf_warning_or_error,
18353 d, /*defer_ok*/true);
18354 /* Don't simply tsubst the function type, as that will give
18355 duplicate warnings about poor parameter qualifications.
18356 The function arguments are the same as the decl_arguments
18357 without the top level cv qualifiers. */
18358 type = TREE_TYPE (type);
18360 tsubst (type, gen_args, tf_warning_or_error, d);
18362 pop_access_scope (d);
18365 /* Defer all other templates, unless we have been explicitly
18366 forbidden from doing so. */
18367 if (/* If there is no definition, we cannot instantiate the
18370 /* If it's OK to postpone instantiation, do so. */
18372 /* If this is a static data member that will be defined
18373 elsewhere, we don't want to instantiate the entire data
18374 member, but we do want to instantiate the initializer so that
18375 we can substitute that elsewhere. */
18376 || (external_p && TREE_CODE (d) == VAR_DECL))
18378 /* The definition of the static data member is now required so
18379 we must substitute the initializer. */
18380 if (TREE_CODE (d) == VAR_DECL
18381 && !DECL_INITIAL (d)
18382 && DECL_INITIAL (code_pattern))
18386 bool const_init = false;
18388 ns = decl_namespace_context (d);
18389 push_nested_namespace (ns);
18390 push_nested_class (DECL_CONTEXT (d));
18391 init = tsubst_expr (DECL_INITIAL (code_pattern),
18393 tf_warning_or_error, NULL_TREE,
18394 /*integral_constant_expression_p=*/false);
18395 /* Make sure the initializer is still constant, in case of
18396 circular dependency (template/instantiate6.C). */
18398 = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (code_pattern);
18399 cp_finish_decl (d, init, /*init_const_expr_p=*/const_init,
18400 /*asmspec_tree=*/NULL_TREE,
18401 LOOKUP_ONLYCONVERTING);
18402 pop_nested_class ();
18403 pop_nested_namespace (ns);
18406 /* We restore the source position here because it's used by
18407 add_pending_template. */
18408 input_location = saved_loc;
18410 if (at_eof && !pattern_defined
18411 && DECL_EXPLICIT_INSTANTIATION (d)
18412 && DECL_NOT_REALLY_EXTERN (d))
18415 The definition of a non-exported function template, a
18416 non-exported member function template, or a non-exported
18417 member function or static data member of a class template
18418 shall be present in every translation unit in which it is
18419 explicitly instantiated. */
18420 permerror (input_location, "explicit instantiation of %qD "
18421 "but no definition available", d);
18423 /* If we're in unevaluated context, we just wanted to get the
18424 constant value; this isn't an odr use, so don't queue
18425 a full instantiation. */
18426 if (cp_unevaluated_operand != 0)
18428 /* ??? Historically, we have instantiated inline functions, even
18429 when marked as "extern template". */
18430 if (!(external_p && TREE_CODE (d) == VAR_DECL))
18431 add_pending_template (d);
18434 /* Tell the repository that D is available in this translation unit
18435 -- and see if it is supposed to be instantiated here. */
18436 if (TREE_PUBLIC (d) && !DECL_REALLY_EXTERN (d) && !repo_emit_p (d))
18438 /* In a PCH file, despite the fact that the repository hasn't
18439 requested instantiation in the PCH it is still possible that
18440 an instantiation will be required in a file that includes the
18443 add_pending_template (d);
18444 /* Instantiate inline functions so that the inliner can do its
18445 job, even though we'll not be emitting a copy of this
18447 if (!(TREE_CODE (d) == FUNCTION_DECL && possibly_inlined_p (d)))
18451 need_push = !cfun || !global_bindings_p ();
18453 push_to_top_level ();
18455 /* Mark D as instantiated so that recursive calls to
18456 instantiate_decl do not try to instantiate it again. */
18457 DECL_TEMPLATE_INSTANTIATED (d) = 1;
18459 /* Regenerate the declaration in case the template has been modified
18460 by a subsequent redeclaration. */
18461 regenerate_decl_from_template (d, td);
18463 /* We already set the file and line above. Reset them now in case
18464 they changed as a result of calling regenerate_decl_from_template. */
18465 input_location = DECL_SOURCE_LOCATION (d);
18467 if (TREE_CODE (d) == VAR_DECL)
18470 bool const_init = false;
18472 /* Clear out DECL_RTL; whatever was there before may not be right
18473 since we've reset the type of the declaration. */
18474 SET_DECL_RTL (d, NULL);
18475 DECL_IN_AGGR_P (d) = 0;
18477 /* The initializer is placed in DECL_INITIAL by
18478 regenerate_decl_from_template so we don't need to
18479 push/pop_access_scope again here. Pull it out so that
18480 cp_finish_decl can process it. */
18481 init = DECL_INITIAL (d);
18482 DECL_INITIAL (d) = NULL_TREE;
18483 DECL_INITIALIZED_P (d) = 0;
18485 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
18486 initializer. That function will defer actual emission until
18487 we have a chance to determine linkage. */
18488 DECL_EXTERNAL (d) = 0;
18490 /* Enter the scope of D so that access-checking works correctly. */
18491 push_nested_class (DECL_CONTEXT (d));
18492 const_init = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (code_pattern);
18493 cp_finish_decl (d, init, const_init, NULL_TREE, 0);
18494 pop_nested_class ();
18496 else if (TREE_CODE (d) == FUNCTION_DECL && DECL_DEFAULTED_FN (code_pattern))
18497 synthesize_method (d);
18498 else if (TREE_CODE (d) == FUNCTION_DECL)
18500 htab_t saved_local_specializations;
18505 /* Save away the current list, in case we are instantiating one
18506 template from within the body of another. */
18507 saved_local_specializations = local_specializations;
18509 /* Set up the list of local specializations. */
18510 local_specializations = htab_create (37,
18511 hash_local_specialization,
18512 eq_local_specializations,
18515 /* Set up context. */
18516 start_preparsed_function (d, NULL_TREE, SF_PRE_PARSED);
18518 /* Create substitution entries for the parameters. */
18519 subst_decl = DECL_TEMPLATE_RESULT (template_for_substitution (d));
18520 tmpl_parm = DECL_ARGUMENTS (subst_decl);
18521 spec_parm = DECL_ARGUMENTS (d);
18522 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (d))
18524 register_local_specialization (spec_parm, tmpl_parm);
18525 spec_parm = skip_artificial_parms_for (d, spec_parm);
18526 tmpl_parm = skip_artificial_parms_for (subst_decl, tmpl_parm);
18528 for (; tmpl_parm; tmpl_parm = DECL_CHAIN (tmpl_parm))
18530 if (!FUNCTION_PARAMETER_PACK_P (tmpl_parm))
18532 register_local_specialization (spec_parm, tmpl_parm);
18533 spec_parm = DECL_CHAIN (spec_parm);
18537 /* Register the (value) argument pack as a specialization of
18538 TMPL_PARM, then move on. */
18539 tree argpack = extract_fnparm_pack (tmpl_parm, &spec_parm);
18540 register_local_specialization (argpack, tmpl_parm);
18543 gcc_assert (!spec_parm);
18545 /* Substitute into the body of the function. */
18546 tsubst_expr (DECL_SAVED_TREE (code_pattern), args,
18547 tf_warning_or_error, tmpl,
18548 /*integral_constant_expression_p=*/false);
18550 /* Set the current input_location to the end of the function
18551 so that finish_function knows where we are. */
18552 input_location = DECL_STRUCT_FUNCTION (code_pattern)->function_end_locus;
18554 /* We don't need the local specializations any more. */
18555 htab_delete (local_specializations);
18556 local_specializations = saved_local_specializations;
18558 /* Finish the function. */
18559 d = finish_function (0);
18560 expand_or_defer_fn (d);
18563 /* We're not deferring instantiation any more. */
18564 TI_PENDING_TEMPLATE_FLAG (DECL_TEMPLATE_INFO (d)) = 0;
18567 pop_from_top_level ();
18570 input_location = saved_loc;
18571 pop_deferring_access_checks ();
18572 pop_tinst_level ();
18574 timevar_pop (TV_TEMPLATE_INST);
18579 /* Run through the list of templates that we wish we could
18580 instantiate, and instantiate any we can. RETRIES is the
18581 number of times we retry pending template instantiation. */
18584 instantiate_pending_templates (int retries)
18587 location_t saved_loc = input_location;
18589 /* Instantiating templates may trigger vtable generation. This in turn
18590 may require further template instantiations. We place a limit here
18591 to avoid infinite loop. */
18592 if (pending_templates && retries >= max_tinst_depth)
18594 tree decl = pending_templates->tinst->decl;
18596 error ("template instantiation depth exceeds maximum of %d"
18597 " instantiating %q+D, possibly from virtual table generation"
18598 " (use -ftemplate-depth= to increase the maximum)",
18599 max_tinst_depth, decl);
18600 if (TREE_CODE (decl) == FUNCTION_DECL)
18601 /* Pretend that we defined it. */
18602 DECL_INITIAL (decl) = error_mark_node;
18608 struct pending_template **t = &pending_templates;
18609 struct pending_template *last = NULL;
18613 tree instantiation = reopen_tinst_level ((*t)->tinst);
18614 bool complete = false;
18616 if (TYPE_P (instantiation))
18620 if (!COMPLETE_TYPE_P (instantiation))
18622 instantiate_class_template (instantiation);
18623 if (CLASSTYPE_TEMPLATE_INSTANTIATION (instantiation))
18624 for (fn = TYPE_METHODS (instantiation);
18626 fn = TREE_CHAIN (fn))
18627 if (! DECL_ARTIFICIAL (fn))
18628 instantiate_decl (fn,
18630 /*expl_inst_class_mem_p=*/false);
18631 if (COMPLETE_TYPE_P (instantiation))
18635 complete = COMPLETE_TYPE_P (instantiation);
18639 if (!DECL_TEMPLATE_SPECIALIZATION (instantiation)
18640 && !DECL_TEMPLATE_INSTANTIATED (instantiation))
18643 = instantiate_decl (instantiation,
18645 /*expl_inst_class_mem_p=*/false);
18646 if (DECL_TEMPLATE_INSTANTIATED (instantiation))
18650 complete = (DECL_TEMPLATE_SPECIALIZATION (instantiation)
18651 || DECL_TEMPLATE_INSTANTIATED (instantiation));
18655 /* If INSTANTIATION has been instantiated, then we don't
18656 need to consider it again in the future. */
18664 current_tinst_level = NULL;
18666 last_pending_template = last;
18668 while (reconsider);
18670 input_location = saved_loc;
18673 /* Substitute ARGVEC into T, which is a list of initializers for
18674 either base class or a non-static data member. The TREE_PURPOSEs
18675 are DECLs, and the TREE_VALUEs are the initializer values. Used by
18676 instantiate_decl. */
18679 tsubst_initializer_list (tree t, tree argvec)
18681 tree inits = NULL_TREE;
18683 for (; t; t = TREE_CHAIN (t))
18687 tree expanded_bases = NULL_TREE;
18688 tree expanded_arguments = NULL_TREE;
18691 if (TREE_CODE (TREE_PURPOSE (t)) == TYPE_PACK_EXPANSION)
18696 /* Expand the base class expansion type into separate base
18698 expanded_bases = tsubst_pack_expansion (TREE_PURPOSE (t), argvec,
18699 tf_warning_or_error,
18701 if (expanded_bases == error_mark_node)
18704 /* We'll be building separate TREE_LISTs of arguments for
18706 len = TREE_VEC_LENGTH (expanded_bases);
18707 expanded_arguments = make_tree_vec (len);
18708 for (i = 0; i < len; i++)
18709 TREE_VEC_ELT (expanded_arguments, i) = NULL_TREE;
18711 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
18712 expand each argument in the TREE_VALUE of t. */
18713 expr = make_node (EXPR_PACK_EXPANSION);
18714 PACK_EXPANSION_PARAMETER_PACKS (expr) =
18715 PACK_EXPANSION_PARAMETER_PACKS (TREE_PURPOSE (t));
18717 if (TREE_VALUE (t) == void_type_node)
18718 /* VOID_TYPE_NODE is used to indicate
18719 value-initialization. */
18721 for (i = 0; i < len; i++)
18722 TREE_VEC_ELT (expanded_arguments, i) = void_type_node;
18726 /* Substitute parameter packs into each argument in the
18728 in_base_initializer = 1;
18729 for (arg = TREE_VALUE (t); arg; arg = TREE_CHAIN (arg))
18731 tree expanded_exprs;
18733 /* Expand the argument. */
18734 SET_PACK_EXPANSION_PATTERN (expr, TREE_VALUE (arg));
18736 = tsubst_pack_expansion (expr, argvec,
18737 tf_warning_or_error,
18739 if (expanded_exprs == error_mark_node)
18742 /* Prepend each of the expanded expressions to the
18743 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
18744 for (i = 0; i < len; i++)
18746 TREE_VEC_ELT (expanded_arguments, i) =
18747 tree_cons (NULL_TREE,
18748 TREE_VEC_ELT (expanded_exprs, i),
18749 TREE_VEC_ELT (expanded_arguments, i));
18752 in_base_initializer = 0;
18754 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
18755 since we built them backwards. */
18756 for (i = 0; i < len; i++)
18758 TREE_VEC_ELT (expanded_arguments, i) =
18759 nreverse (TREE_VEC_ELT (expanded_arguments, i));
18764 for (i = 0; i < len; ++i)
18766 if (expanded_bases)
18768 decl = TREE_VEC_ELT (expanded_bases, i);
18769 decl = expand_member_init (decl);
18770 init = TREE_VEC_ELT (expanded_arguments, i);
18774 decl = tsubst_copy (TREE_PURPOSE (t), argvec,
18775 tf_warning_or_error, NULL_TREE);
18777 decl = expand_member_init (decl);
18778 if (decl && !DECL_P (decl))
18779 in_base_initializer = 1;
18781 init = TREE_VALUE (t);
18782 if (init != void_type_node)
18783 init = tsubst_expr (init, argvec,
18784 tf_warning_or_error, NULL_TREE,
18785 /*integral_constant_expression_p=*/false);
18786 in_base_initializer = 0;
18791 init = build_tree_list (decl, init);
18792 TREE_CHAIN (init) = inits;
18800 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
18803 set_current_access_from_decl (tree decl)
18805 if (TREE_PRIVATE (decl))
18806 current_access_specifier = access_private_node;
18807 else if (TREE_PROTECTED (decl))
18808 current_access_specifier = access_protected_node;
18810 current_access_specifier = access_public_node;
18813 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
18814 is the instantiation (which should have been created with
18815 start_enum) and ARGS are the template arguments to use. */
18818 tsubst_enum (tree tag, tree newtag, tree args)
18822 if (SCOPED_ENUM_P (newtag))
18823 begin_scope (sk_scoped_enum, newtag);
18825 for (e = TYPE_VALUES (tag); e; e = TREE_CHAIN (e))
18830 decl = TREE_VALUE (e);
18831 /* Note that in a template enum, the TREE_VALUE is the
18832 CONST_DECL, not the corresponding INTEGER_CST. */
18833 value = tsubst_expr (DECL_INITIAL (decl),
18834 args, tf_warning_or_error, NULL_TREE,
18835 /*integral_constant_expression_p=*/true);
18837 /* Give this enumeration constant the correct access. */
18838 set_current_access_from_decl (decl);
18840 /* Actually build the enumerator itself. */
18842 (DECL_NAME (decl), value, newtag, DECL_SOURCE_LOCATION (decl));
18845 if (SCOPED_ENUM_P (newtag))
18848 finish_enum_value_list (newtag);
18849 finish_enum (newtag);
18851 DECL_SOURCE_LOCATION (TYPE_NAME (newtag))
18852 = DECL_SOURCE_LOCATION (TYPE_NAME (tag));
18855 /* DECL is a FUNCTION_DECL that is a template specialization. Return
18856 its type -- but without substituting the innermost set of template
18857 arguments. So, innermost set of template parameters will appear in
18861 get_mostly_instantiated_function_type (tree decl)
18869 tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
18870 targs = DECL_TI_ARGS (decl);
18871 tparms = DECL_TEMPLATE_PARMS (tmpl);
18872 parm_depth = TMPL_PARMS_DEPTH (tparms);
18874 /* There should be as many levels of arguments as there are levels
18876 gcc_assert (parm_depth == TMPL_ARGS_DEPTH (targs));
18878 fn_type = TREE_TYPE (tmpl);
18880 if (parm_depth == 1)
18881 /* No substitution is necessary. */
18888 /* Replace the innermost level of the TARGS with NULL_TREEs to
18889 let tsubst know not to substitute for those parameters. */
18890 partial_args = make_tree_vec (TREE_VEC_LENGTH (targs));
18891 for (i = 1; i < TMPL_ARGS_DEPTH (targs); ++i)
18892 SET_TMPL_ARGS_LEVEL (partial_args, i,
18893 TMPL_ARGS_LEVEL (targs, i));
18894 SET_TMPL_ARGS_LEVEL (partial_args,
18895 TMPL_ARGS_DEPTH (targs),
18896 make_tree_vec (DECL_NTPARMS (tmpl)));
18898 /* Make sure that we can see identifiers, and compute access
18900 push_access_scope (decl);
18902 ++processing_template_decl;
18903 /* Now, do the (partial) substitution to figure out the
18904 appropriate function type. */
18905 fn_type = tsubst (fn_type, partial_args, tf_error, NULL_TREE);
18906 --processing_template_decl;
18908 /* Substitute into the template parameters to obtain the real
18909 innermost set of parameters. This step is important if the
18910 innermost set of template parameters contains value
18911 parameters whose types depend on outer template parameters. */
18912 TREE_VEC_LENGTH (partial_args)--;
18913 tparms = tsubst_template_parms (tparms, partial_args, tf_error);
18915 pop_access_scope (decl);
18921 /* Return truthvalue if we're processing a template different from
18922 the last one involved in diagnostics. */
18924 problematic_instantiation_changed (void)
18926 return current_tinst_level != last_error_tinst_level;
18929 /* Remember current template involved in diagnostics. */
18931 record_last_problematic_instantiation (void)
18933 last_error_tinst_level = current_tinst_level;
18936 struct tinst_level *
18937 current_instantiation (void)
18939 return current_tinst_level;
18942 /* [temp.param] Check that template non-type parm TYPE is of an allowable
18943 type. Return zero for ok, nonzero for disallowed. Issue error and
18944 warning messages under control of COMPLAIN. */
18947 invalid_nontype_parm_type_p (tree type, tsubst_flags_t complain)
18949 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
18951 else if (POINTER_TYPE_P (type))
18953 else if (TYPE_PTR_TO_MEMBER_P (type))
18955 else if (TREE_CODE (type) == TEMPLATE_TYPE_PARM)
18957 else if (TREE_CODE (type) == TYPENAME_TYPE)
18959 else if (TREE_CODE (type) == DECLTYPE_TYPE)
18961 else if (TREE_CODE (type) == NULLPTR_TYPE)
18964 if (complain & tf_error)
18965 error ("%q#T is not a valid type for a template constant parameter", type);
18969 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
18970 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
18973 dependent_type_p_r (tree type)
18979 A type is dependent if it is:
18981 -- a template parameter. Template template parameters are types
18982 for us (since TYPE_P holds true for them) so we handle
18984 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
18985 || TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM)
18987 /* -- a qualified-id with a nested-name-specifier which contains a
18988 class-name that names a dependent type or whose unqualified-id
18989 names a dependent type. */
18990 if (TREE_CODE (type) == TYPENAME_TYPE)
18992 /* -- a cv-qualified type where the cv-unqualified type is
18994 type = TYPE_MAIN_VARIANT (type);
18995 /* -- a compound type constructed from any dependent type. */
18996 if (TYPE_PTR_TO_MEMBER_P (type))
18997 return (dependent_type_p (TYPE_PTRMEM_CLASS_TYPE (type))
18998 || dependent_type_p (TYPE_PTRMEM_POINTED_TO_TYPE
19000 else if (TREE_CODE (type) == POINTER_TYPE
19001 || TREE_CODE (type) == REFERENCE_TYPE)
19002 return dependent_type_p (TREE_TYPE (type));
19003 else if (TREE_CODE (type) == FUNCTION_TYPE
19004 || TREE_CODE (type) == METHOD_TYPE)
19008 if (dependent_type_p (TREE_TYPE (type)))
19010 for (arg_type = TYPE_ARG_TYPES (type);
19012 arg_type = TREE_CHAIN (arg_type))
19013 if (dependent_type_p (TREE_VALUE (arg_type)))
19017 /* -- an array type constructed from any dependent type or whose
19018 size is specified by a constant expression that is
19021 We checked for type- and value-dependence of the bounds in
19022 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
19023 if (TREE_CODE (type) == ARRAY_TYPE)
19025 if (TYPE_DOMAIN (type)
19026 && dependent_type_p (TYPE_DOMAIN (type)))
19028 return dependent_type_p (TREE_TYPE (type));
19031 /* -- a template-id in which either the template name is a template
19033 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
19035 /* ... or any of the template arguments is a dependent type or
19036 an expression that is type-dependent or value-dependent. */
19037 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INFO (type)
19038 && (any_dependent_template_arguments_p
19039 (INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type)))))
19042 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
19043 dependent; if the argument of the `typeof' expression is not
19044 type-dependent, then it should already been have resolved. */
19045 if (TREE_CODE (type) == TYPEOF_TYPE
19046 || TREE_CODE (type) == DECLTYPE_TYPE
19047 || TREE_CODE (type) == UNDERLYING_TYPE)
19050 /* A template argument pack is dependent if any of its packed
19052 if (TREE_CODE (type) == TYPE_ARGUMENT_PACK)
19054 tree args = ARGUMENT_PACK_ARGS (type);
19055 int i, len = TREE_VEC_LENGTH (args);
19056 for (i = 0; i < len; ++i)
19057 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
19061 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
19062 be template parameters. */
19063 if (TREE_CODE (type) == TYPE_PACK_EXPANSION)
19066 /* The standard does not specifically mention types that are local
19067 to template functions or local classes, but they should be
19068 considered dependent too. For example:
19070 template <int I> void f() {
19075 The size of `E' cannot be known until the value of `I' has been
19076 determined. Therefore, `E' must be considered dependent. */
19077 scope = TYPE_CONTEXT (type);
19078 if (scope && TYPE_P (scope))
19079 return dependent_type_p (scope);
19080 /* Don't use type_dependent_expression_p here, as it can lead
19081 to infinite recursion trying to determine whether a lambda
19082 nested in a lambda is dependent (c++/47687). */
19083 else if (scope && TREE_CODE (scope) == FUNCTION_DECL
19084 && DECL_LANG_SPECIFIC (scope)
19085 && DECL_TEMPLATE_INFO (scope)
19086 && (any_dependent_template_arguments_p
19087 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (scope)))))
19090 /* Other types are non-dependent. */
19094 /* Returns TRUE if TYPE is dependent, in the sense of
19095 [temp.dep.type]. Note that a NULL type is considered dependent. */
19098 dependent_type_p (tree type)
19100 /* If there are no template parameters in scope, then there can't be
19101 any dependent types. */
19102 if (!processing_template_decl)
19104 /* If we are not processing a template, then nobody should be
19105 providing us with a dependent type. */
19107 gcc_assert (TREE_CODE (type) != TEMPLATE_TYPE_PARM || is_auto (type));
19111 /* If the type is NULL, we have not computed a type for the entity
19112 in question; in that case, the type is dependent. */
19116 /* Erroneous types can be considered non-dependent. */
19117 if (type == error_mark_node)
19120 /* If we have not already computed the appropriate value for TYPE,
19122 if (!TYPE_DEPENDENT_P_VALID (type))
19124 TYPE_DEPENDENT_P (type) = dependent_type_p_r (type);
19125 TYPE_DEPENDENT_P_VALID (type) = 1;
19128 return TYPE_DEPENDENT_P (type);
19131 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
19132 lookup. In other words, a dependent type that is not the current
19136 dependent_scope_p (tree scope)
19138 return (scope && TYPE_P (scope) && dependent_type_p (scope)
19139 && !currently_open_class (scope));
19142 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
19143 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
19146 /* Note that this predicate is not appropriate for general expressions;
19147 only constant expressions (that satisfy potential_constant_expression)
19148 can be tested for value dependence.
19150 We should really also have a predicate for "instantiation-dependent".
19152 fold_non_dependent_expr: fold if constant and not type-dependent and not value-dependent.
19153 (what about instantiation-dependent constant-expressions?)
19154 is_late_template_attribute: defer if instantiation-dependent.
19155 compute_array_index_type: proceed if constant and not t- or v-dependent
19156 if instantiation-dependent, need to remember full expression
19157 uses_template_parms: FIXME - need to audit callers
19158 tsubst_decl [function_decl]: Why is this using value_dependent_expression_p?
19159 dependent_type_p [array_type]: dependent if index type is dependent
19161 static_assert - instantiation-dependent */
19164 value_dependent_expression_p (tree expression)
19166 if (!processing_template_decl)
19169 /* A name declared with a dependent type. */
19170 if (DECL_P (expression) && type_dependent_expression_p (expression))
19173 switch (TREE_CODE (expression))
19175 case IDENTIFIER_NODE:
19176 /* A name that has not been looked up -- must be dependent. */
19179 case TEMPLATE_PARM_INDEX:
19180 /* A non-type template parm. */
19184 /* A non-type template parm. */
19185 if (DECL_TEMPLATE_PARM_P (expression))
19187 return value_dependent_expression_p (DECL_INITIAL (expression));
19190 /* A constant with literal type and is initialized
19191 with an expression that is value-dependent. */
19192 if (DECL_INITIAL (expression)
19193 && decl_constant_var_p (expression)
19194 && value_dependent_expression_p (DECL_INITIAL (expression)))
19198 case DYNAMIC_CAST_EXPR:
19199 case STATIC_CAST_EXPR:
19200 case CONST_CAST_EXPR:
19201 case REINTERPRET_CAST_EXPR:
19203 /* These expressions are value-dependent if the type to which
19204 the cast occurs is dependent or the expression being casted
19205 is value-dependent. */
19207 tree type = TREE_TYPE (expression);
19209 if (dependent_type_p (type))
19212 /* A functional cast has a list of operands. */
19213 expression = TREE_OPERAND (expression, 0);
19216 /* If there are no operands, it must be an expression such
19217 as "int()". This should not happen for aggregate types
19218 because it would form non-constant expressions. */
19219 gcc_assert (cxx_dialect >= cxx0x
19220 || INTEGRAL_OR_ENUMERATION_TYPE_P (type));
19225 if (TREE_CODE (expression) == TREE_LIST)
19226 return any_value_dependent_elements_p (expression);
19228 return value_dependent_expression_p (expression);
19234 /* A `sizeof' expression is value-dependent if the operand is
19235 type-dependent or is a pack expansion. */
19236 expression = TREE_OPERAND (expression, 0);
19237 if (PACK_EXPANSION_P (expression))
19239 else if (TYPE_P (expression))
19240 return dependent_type_p (expression);
19241 return type_dependent_expression_p (expression);
19243 case AT_ENCODE_EXPR:
19244 /* An 'encode' expression is value-dependent if the operand is
19246 expression = TREE_OPERAND (expression, 0);
19247 return dependent_type_p (expression);
19249 case NOEXCEPT_EXPR:
19250 expression = TREE_OPERAND (expression, 0);
19251 return type_dependent_expression_p (expression);
19255 tree name = TREE_OPERAND (expression, 1);
19256 return value_dependent_expression_p (name);
19259 case COMPONENT_REF:
19260 return (value_dependent_expression_p (TREE_OPERAND (expression, 0))
19261 || value_dependent_expression_p (TREE_OPERAND (expression, 1)));
19263 case NONTYPE_ARGUMENT_PACK:
19264 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
19265 is value-dependent. */
19267 tree values = ARGUMENT_PACK_ARGS (expression);
19268 int i, len = TREE_VEC_LENGTH (values);
19270 for (i = 0; i < len; ++i)
19271 if (value_dependent_expression_p (TREE_VEC_ELT (values, i)))
19279 tree type2 = TRAIT_EXPR_TYPE2 (expression);
19280 return (dependent_type_p (TRAIT_EXPR_TYPE1 (expression))
19281 || (type2 ? dependent_type_p (type2) : false));
19285 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
19286 || (value_dependent_expression_p (TREE_OPERAND (expression, 2))));
19289 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
19290 || (value_dependent_expression_p (TREE_OPERAND (expression, 1))));
19294 tree op = TREE_OPERAND (expression, 0);
19295 return (value_dependent_expression_p (op)
19296 || has_value_dependent_address (op));
19301 tree fn = get_callee_fndecl (expression);
19303 if (!fn && value_dependent_expression_p (CALL_EXPR_FN (expression)))
19305 nargs = call_expr_nargs (expression);
19306 for (i = 0; i < nargs; ++i)
19308 tree op = CALL_EXPR_ARG (expression, i);
19309 /* In a call to a constexpr member function, look through the
19310 implicit ADDR_EXPR on the object argument so that it doesn't
19311 cause the call to be considered value-dependent. We also
19312 look through it in potential_constant_expression. */
19313 if (i == 0 && fn && DECL_DECLARED_CONSTEXPR_P (fn)
19314 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
19315 && TREE_CODE (op) == ADDR_EXPR)
19316 op = TREE_OPERAND (op, 0);
19317 if (value_dependent_expression_p (op))
19323 case TEMPLATE_ID_EXPR:
19324 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
19326 return type_dependent_expression_p (expression);
19332 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), ix, val)
19333 if (value_dependent_expression_p (val))
19339 /* A constant expression is value-dependent if any subexpression is
19340 value-dependent. */
19341 switch (TREE_CODE_CLASS (TREE_CODE (expression)))
19343 case tcc_reference:
19345 case tcc_comparison:
19347 case tcc_expression:
19350 int i, len = cp_tree_operand_length (expression);
19352 for (i = 0; i < len; i++)
19354 tree t = TREE_OPERAND (expression, i);
19356 /* In some cases, some of the operands may be missing.l
19357 (For example, in the case of PREDECREMENT_EXPR, the
19358 amount to increment by may be missing.) That doesn't
19359 make the expression dependent. */
19360 if (t && value_dependent_expression_p (t))
19371 /* The expression is not value-dependent. */
19375 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
19376 [temp.dep.expr]. Note that an expression with no type is
19377 considered dependent. Other parts of the compiler arrange for an
19378 expression with type-dependent subexpressions to have no type, so
19379 this function doesn't have to be fully recursive. */
19382 type_dependent_expression_p (tree expression)
19384 if (!processing_template_decl)
19387 if (expression == error_mark_node)
19390 /* An unresolved name is always dependent. */
19391 if (TREE_CODE (expression) == IDENTIFIER_NODE
19392 || TREE_CODE (expression) == USING_DECL)
19395 /* Some expression forms are never type-dependent. */
19396 if (TREE_CODE (expression) == PSEUDO_DTOR_EXPR
19397 || TREE_CODE (expression) == SIZEOF_EXPR
19398 || TREE_CODE (expression) == ALIGNOF_EXPR
19399 || TREE_CODE (expression) == AT_ENCODE_EXPR
19400 || TREE_CODE (expression) == NOEXCEPT_EXPR
19401 || TREE_CODE (expression) == TRAIT_EXPR
19402 || TREE_CODE (expression) == TYPEID_EXPR
19403 || TREE_CODE (expression) == DELETE_EXPR
19404 || TREE_CODE (expression) == VEC_DELETE_EXPR
19405 || TREE_CODE (expression) == THROW_EXPR)
19408 /* The types of these expressions depends only on the type to which
19409 the cast occurs. */
19410 if (TREE_CODE (expression) == DYNAMIC_CAST_EXPR
19411 || TREE_CODE (expression) == STATIC_CAST_EXPR
19412 || TREE_CODE (expression) == CONST_CAST_EXPR
19413 || TREE_CODE (expression) == REINTERPRET_CAST_EXPR
19414 || TREE_CODE (expression) == IMPLICIT_CONV_EXPR
19415 || TREE_CODE (expression) == CAST_EXPR)
19416 return dependent_type_p (TREE_TYPE (expression));
19418 /* The types of these expressions depends only on the type created
19419 by the expression. */
19420 if (TREE_CODE (expression) == NEW_EXPR
19421 || TREE_CODE (expression) == VEC_NEW_EXPR)
19423 /* For NEW_EXPR tree nodes created inside a template, either
19424 the object type itself or a TREE_LIST may appear as the
19426 tree type = TREE_OPERAND (expression, 1);
19427 if (TREE_CODE (type) == TREE_LIST)
19428 /* This is an array type. We need to check array dimensions
19430 return dependent_type_p (TREE_VALUE (TREE_PURPOSE (type)))
19431 || value_dependent_expression_p
19432 (TREE_OPERAND (TREE_VALUE (type), 1));
19434 return dependent_type_p (type);
19437 if (TREE_CODE (expression) == SCOPE_REF)
19439 tree scope = TREE_OPERAND (expression, 0);
19440 tree name = TREE_OPERAND (expression, 1);
19442 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
19443 contains an identifier associated by name lookup with one or more
19444 declarations declared with a dependent type, or...a
19445 nested-name-specifier or qualified-id that names a member of an
19446 unknown specialization. */
19447 return (type_dependent_expression_p (name)
19448 || dependent_scope_p (scope));
19451 if (TREE_CODE (expression) == FUNCTION_DECL
19452 && DECL_LANG_SPECIFIC (expression)
19453 && DECL_TEMPLATE_INFO (expression)
19454 && (any_dependent_template_arguments_p
19455 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (expression)))))
19458 if (TREE_CODE (expression) == TEMPLATE_DECL
19459 && !DECL_TEMPLATE_TEMPLATE_PARM_P (expression))
19462 if (TREE_CODE (expression) == STMT_EXPR)
19463 expression = stmt_expr_value_expr (expression);
19465 if (BRACE_ENCLOSED_INITIALIZER_P (expression))
19470 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), i, elt)
19472 if (type_dependent_expression_p (elt))
19478 /* A static data member of the current instantiation with incomplete
19479 array type is type-dependent, as the definition and specializations
19480 can have different bounds. */
19481 if (TREE_CODE (expression) == VAR_DECL
19482 && DECL_CLASS_SCOPE_P (expression)
19483 && dependent_type_p (DECL_CONTEXT (expression))
19484 && VAR_HAD_UNKNOWN_BOUND (expression))
19487 if (TREE_TYPE (expression) == unknown_type_node)
19489 if (TREE_CODE (expression) == ADDR_EXPR)
19490 return type_dependent_expression_p (TREE_OPERAND (expression, 0));
19491 if (TREE_CODE (expression) == COMPONENT_REF
19492 || TREE_CODE (expression) == OFFSET_REF)
19494 if (type_dependent_expression_p (TREE_OPERAND (expression, 0)))
19496 expression = TREE_OPERAND (expression, 1);
19497 if (TREE_CODE (expression) == IDENTIFIER_NODE)
19500 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
19501 if (TREE_CODE (expression) == SCOPE_REF)
19504 if (BASELINK_P (expression))
19505 expression = BASELINK_FUNCTIONS (expression);
19507 if (TREE_CODE (expression) == TEMPLATE_ID_EXPR)
19509 if (any_dependent_template_arguments_p
19510 (TREE_OPERAND (expression, 1)))
19512 expression = TREE_OPERAND (expression, 0);
19514 gcc_assert (TREE_CODE (expression) == OVERLOAD
19515 || TREE_CODE (expression) == FUNCTION_DECL);
19519 if (type_dependent_expression_p (OVL_CURRENT (expression)))
19521 expression = OVL_NEXT (expression);
19526 gcc_assert (TREE_CODE (expression) != TYPE_DECL);
19528 return (dependent_type_p (TREE_TYPE (expression)));
19531 /* Like type_dependent_expression_p, but it also works while not processing
19532 a template definition, i.e. during substitution or mangling. */
19535 type_dependent_expression_p_push (tree expr)
19538 ++processing_template_decl;
19539 b = type_dependent_expression_p (expr);
19540 --processing_template_decl;
19544 /* Returns TRUE if ARGS contains a type-dependent expression. */
19547 any_type_dependent_arguments_p (const VEC(tree,gc) *args)
19552 FOR_EACH_VEC_ELT (tree, args, i, arg)
19554 if (type_dependent_expression_p (arg))
19560 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
19561 expressions) contains any type-dependent expressions. */
19564 any_type_dependent_elements_p (const_tree list)
19566 for (; list; list = TREE_CHAIN (list))
19567 if (value_dependent_expression_p (TREE_VALUE (list)))
19573 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
19574 expressions) contains any value-dependent expressions. */
19577 any_value_dependent_elements_p (const_tree list)
19579 for (; list; list = TREE_CHAIN (list))
19580 if (value_dependent_expression_p (TREE_VALUE (list)))
19586 /* Returns TRUE if the ARG (a template argument) is dependent. */
19589 dependent_template_arg_p (tree arg)
19591 if (!processing_template_decl)
19594 /* Assume a template argument that was wrongly written by the user
19595 is dependent. This is consistent with what
19596 any_dependent_template_arguments_p [that calls this function]
19598 if (!arg || arg == error_mark_node)
19601 if (TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
19602 arg = ARGUMENT_PACK_SELECT_ARG (arg);
19604 if (TREE_CODE (arg) == TEMPLATE_DECL
19605 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
19606 return dependent_template_p (arg);
19607 else if (ARGUMENT_PACK_P (arg))
19609 tree args = ARGUMENT_PACK_ARGS (arg);
19610 int i, len = TREE_VEC_LENGTH (args);
19611 for (i = 0; i < len; ++i)
19613 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
19619 else if (TYPE_P (arg))
19620 return dependent_type_p (arg);
19622 return (type_dependent_expression_p (arg)
19623 || value_dependent_expression_p (arg));
19626 /* Returns true if ARGS (a collection of template arguments) contains
19627 any types that require structural equality testing. */
19630 any_template_arguments_need_structural_equality_p (tree args)
19637 if (args == error_mark_node)
19640 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
19642 tree level = TMPL_ARGS_LEVEL (args, i + 1);
19643 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
19645 tree arg = TREE_VEC_ELT (level, j);
19646 tree packed_args = NULL_TREE;
19649 if (ARGUMENT_PACK_P (arg))
19651 /* Look inside the argument pack. */
19652 packed_args = ARGUMENT_PACK_ARGS (arg);
19653 len = TREE_VEC_LENGTH (packed_args);
19656 for (k = 0; k < len; ++k)
19659 arg = TREE_VEC_ELT (packed_args, k);
19661 if (error_operand_p (arg))
19663 else if (TREE_CODE (arg) == TEMPLATE_DECL
19664 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
19666 else if (TYPE_P (arg) && TYPE_STRUCTURAL_EQUALITY_P (arg))
19668 else if (!TYPE_P (arg) && TREE_TYPE (arg)
19669 && TYPE_STRUCTURAL_EQUALITY_P (TREE_TYPE (arg)))
19678 /* Returns true if ARGS (a collection of template arguments) contains
19679 any dependent arguments. */
19682 any_dependent_template_arguments_p (const_tree args)
19689 if (args == error_mark_node)
19692 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
19694 const_tree level = TMPL_ARGS_LEVEL (args, i + 1);
19695 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
19696 if (dependent_template_arg_p (TREE_VEC_ELT (level, j)))
19703 /* Returns TRUE if the template TMPL is dependent. */
19706 dependent_template_p (tree tmpl)
19708 if (TREE_CODE (tmpl) == OVERLOAD)
19712 if (dependent_template_p (OVL_CURRENT (tmpl)))
19714 tmpl = OVL_NEXT (tmpl);
19719 /* Template template parameters are dependent. */
19720 if (DECL_TEMPLATE_TEMPLATE_PARM_P (tmpl)
19721 || TREE_CODE (tmpl) == TEMPLATE_TEMPLATE_PARM)
19723 /* So are names that have not been looked up. */
19724 if (TREE_CODE (tmpl) == SCOPE_REF
19725 || TREE_CODE (tmpl) == IDENTIFIER_NODE)
19727 /* So are member templates of dependent classes. */
19728 if (TYPE_P (CP_DECL_CONTEXT (tmpl)))
19729 return dependent_type_p (DECL_CONTEXT (tmpl));
19733 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
19736 dependent_template_id_p (tree tmpl, tree args)
19738 return (dependent_template_p (tmpl)
19739 || any_dependent_template_arguments_p (args));
19742 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
19746 dependent_omp_for_p (tree declv, tree initv, tree condv, tree incrv)
19750 if (!processing_template_decl)
19753 for (i = 0; i < TREE_VEC_LENGTH (declv); i++)
19755 tree decl = TREE_VEC_ELT (declv, i);
19756 tree init = TREE_VEC_ELT (initv, i);
19757 tree cond = TREE_VEC_ELT (condv, i);
19758 tree incr = TREE_VEC_ELT (incrv, i);
19760 if (type_dependent_expression_p (decl))
19763 if (init && type_dependent_expression_p (init))
19766 if (type_dependent_expression_p (cond))
19769 if (COMPARISON_CLASS_P (cond)
19770 && (type_dependent_expression_p (TREE_OPERAND (cond, 0))
19771 || type_dependent_expression_p (TREE_OPERAND (cond, 1))))
19774 if (TREE_CODE (incr) == MODOP_EXPR)
19776 if (type_dependent_expression_p (TREE_OPERAND (incr, 0))
19777 || type_dependent_expression_p (TREE_OPERAND (incr, 2)))
19780 else if (type_dependent_expression_p (incr))
19782 else if (TREE_CODE (incr) == MODIFY_EXPR)
19784 if (type_dependent_expression_p (TREE_OPERAND (incr, 0)))
19786 else if (BINARY_CLASS_P (TREE_OPERAND (incr, 1)))
19788 tree t = TREE_OPERAND (incr, 1);
19789 if (type_dependent_expression_p (TREE_OPERAND (t, 0))
19790 || type_dependent_expression_p (TREE_OPERAND (t, 1)))
19799 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
19800 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
19801 no such TYPE can be found. Note that this function peers inside
19802 uninstantiated templates and therefore should be used only in
19803 extremely limited situations. ONLY_CURRENT_P restricts this
19804 peering to the currently open classes hierarchy (which is required
19805 when comparing types). */
19808 resolve_typename_type (tree type, bool only_current_p)
19817 gcc_assert (TREE_CODE (type) == TYPENAME_TYPE);
19819 scope = TYPE_CONTEXT (type);
19820 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
19821 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
19822 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
19823 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
19824 identifier of the TYPENAME_TYPE anymore.
19825 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
19826 TYPENAME_TYPE instead, we avoid messing up with a possible
19827 typedef variant case. */
19828 name = TYPE_IDENTIFIER (TYPE_MAIN_VARIANT (type));
19830 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
19831 it first before we can figure out what NAME refers to. */
19832 if (TREE_CODE (scope) == TYPENAME_TYPE)
19833 scope = resolve_typename_type (scope, only_current_p);
19834 /* If we don't know what SCOPE refers to, then we cannot resolve the
19836 if (TREE_CODE (scope) == TYPENAME_TYPE)
19838 /* If the SCOPE is a template type parameter, we have no way of
19839 resolving the name. */
19840 if (TREE_CODE (scope) == TEMPLATE_TYPE_PARM)
19842 /* If the SCOPE is not the current instantiation, there's no reason
19843 to look inside it. */
19844 if (only_current_p && !currently_open_class (scope))
19846 /* If this is a typedef, we don't want to look inside (c++/11987). */
19847 if (typedef_variant_p (type))
19849 /* If SCOPE isn't the template itself, it will not have a valid
19850 TYPE_FIELDS list. */
19851 if (same_type_p (scope, CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope)))
19852 /* scope is either the template itself or a compatible instantiation
19853 like X<T>, so look up the name in the original template. */
19854 scope = CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope);
19856 /* scope is a partial instantiation, so we can't do the lookup or we
19857 will lose the template arguments. */
19859 /* Enter the SCOPE so that name lookup will be resolved as if we
19860 were in the class definition. In particular, SCOPE will no
19861 longer be considered a dependent type. */
19862 pushed_scope = push_scope (scope);
19863 /* Look up the declaration. */
19864 decl = lookup_member (scope, name, /*protect=*/0, /*want_type=*/true);
19866 result = NULL_TREE;
19868 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
19869 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
19872 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == IDENTIFIER_NODE
19873 && TREE_CODE (decl) == TYPE_DECL)
19875 result = TREE_TYPE (decl);
19876 if (result == error_mark_node)
19877 result = NULL_TREE;
19879 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == TEMPLATE_ID_EXPR
19880 && DECL_CLASS_TEMPLATE_P (decl))
19884 /* Obtain the template and the arguments. */
19885 tmpl = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 0);
19886 args = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 1);
19887 /* Instantiate the template. */
19888 result = lookup_template_class (tmpl, args, NULL_TREE, NULL_TREE,
19889 /*entering_scope=*/0,
19890 tf_error | tf_user);
19891 if (result == error_mark_node)
19892 result = NULL_TREE;
19895 /* Leave the SCOPE. */
19897 pop_scope (pushed_scope);
19899 /* If we failed to resolve it, return the original typename. */
19903 /* If lookup found a typename type, resolve that too. */
19904 if (TREE_CODE (result) == TYPENAME_TYPE && !TYPENAME_IS_RESOLVING_P (result))
19906 /* Ill-formed programs can cause infinite recursion here, so we
19907 must catch that. */
19908 TYPENAME_IS_RESOLVING_P (type) = 1;
19909 result = resolve_typename_type (result, only_current_p);
19910 TYPENAME_IS_RESOLVING_P (type) = 0;
19913 /* Qualify the resulting type. */
19914 quals = cp_type_quals (type);
19916 result = cp_build_qualified_type (result, cp_type_quals (result) | quals);
19921 /* EXPR is an expression which is not type-dependent. Return a proxy
19922 for EXPR that can be used to compute the types of larger
19923 expressions containing EXPR. */
19926 build_non_dependent_expr (tree expr)
19930 #ifdef ENABLE_CHECKING
19931 /* Try to get a constant value for all non-type-dependent expressions in
19932 order to expose bugs in *_dependent_expression_p and constexpr. */
19933 if (cxx_dialect >= cxx0x)
19934 maybe_constant_value (fold_non_dependent_expr_sfinae (expr, tf_none));
19937 /* Preserve OVERLOADs; the functions must be available to resolve
19940 if (TREE_CODE (inner_expr) == STMT_EXPR)
19941 inner_expr = stmt_expr_value_expr (inner_expr);
19942 if (TREE_CODE (inner_expr) == ADDR_EXPR)
19943 inner_expr = TREE_OPERAND (inner_expr, 0);
19944 if (TREE_CODE (inner_expr) == COMPONENT_REF)
19945 inner_expr = TREE_OPERAND (inner_expr, 1);
19946 if (is_overloaded_fn (inner_expr)
19947 || TREE_CODE (inner_expr) == OFFSET_REF)
19949 /* There is no need to return a proxy for a variable. */
19950 if (TREE_CODE (expr) == VAR_DECL)
19952 /* Preserve string constants; conversions from string constants to
19953 "char *" are allowed, even though normally a "const char *"
19954 cannot be used to initialize a "char *". */
19955 if (TREE_CODE (expr) == STRING_CST)
19957 /* Preserve arithmetic constants, as an optimization -- there is no
19958 reason to create a new node. */
19959 if (TREE_CODE (expr) == INTEGER_CST || TREE_CODE (expr) == REAL_CST)
19961 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
19962 There is at least one place where we want to know that a
19963 particular expression is a throw-expression: when checking a ?:
19964 expression, there are special rules if the second or third
19965 argument is a throw-expression. */
19966 if (TREE_CODE (expr) == THROW_EXPR)
19969 /* Don't wrap an initializer list, we need to be able to look inside. */
19970 if (BRACE_ENCLOSED_INITIALIZER_P (expr))
19973 if (TREE_CODE (expr) == COND_EXPR)
19974 return build3 (COND_EXPR,
19976 TREE_OPERAND (expr, 0),
19977 (TREE_OPERAND (expr, 1)
19978 ? build_non_dependent_expr (TREE_OPERAND (expr, 1))
19979 : build_non_dependent_expr (TREE_OPERAND (expr, 0))),
19980 build_non_dependent_expr (TREE_OPERAND (expr, 2)));
19981 if (TREE_CODE (expr) == COMPOUND_EXPR
19982 && !COMPOUND_EXPR_OVERLOADED (expr))
19983 return build2 (COMPOUND_EXPR,
19985 TREE_OPERAND (expr, 0),
19986 build_non_dependent_expr (TREE_OPERAND (expr, 1)));
19988 /* If the type is unknown, it can't really be non-dependent */
19989 gcc_assert (TREE_TYPE (expr) != unknown_type_node);
19991 /* Otherwise, build a NON_DEPENDENT_EXPR. */
19992 return build1 (NON_DEPENDENT_EXPR, TREE_TYPE (expr), expr);
19995 /* ARGS is a vector of expressions as arguments to a function call.
19996 Replace the arguments with equivalent non-dependent expressions.
19997 This modifies ARGS in place. */
20000 make_args_non_dependent (VEC(tree,gc) *args)
20005 FOR_EACH_VEC_ELT (tree, args, ix, arg)
20007 tree newarg = build_non_dependent_expr (arg);
20009 VEC_replace (tree, args, ix, newarg);
20013 /* Returns a type which represents 'auto'. We use a TEMPLATE_TYPE_PARM
20014 with a level one deeper than the actual template parms. */
20019 tree au = cxx_make_type (TEMPLATE_TYPE_PARM);
20020 TYPE_NAME (au) = build_decl (BUILTINS_LOCATION,
20021 TYPE_DECL, get_identifier ("auto"), au);
20022 TYPE_STUB_DECL (au) = TYPE_NAME (au);
20023 TEMPLATE_TYPE_PARM_INDEX (au) = build_template_parm_index
20024 (0, processing_template_decl + 1, processing_template_decl + 1,
20025 0, TYPE_NAME (au), NULL_TREE);
20026 TYPE_CANONICAL (au) = canonical_type_parameter (au);
20027 DECL_ARTIFICIAL (TYPE_NAME (au)) = 1;
20028 SET_DECL_TEMPLATE_PARM_P (TYPE_NAME (au));
20033 /* Given type ARG, return std::initializer_list<ARG>. */
20038 tree std_init_list = namespace_binding
20039 (get_identifier ("initializer_list"), std_node);
20041 if (!std_init_list || !DECL_CLASS_TEMPLATE_P (std_init_list))
20043 error ("deducing from brace-enclosed initializer list requires "
20044 "#include <initializer_list>");
20045 return error_mark_node;
20047 argvec = make_tree_vec (1);
20048 TREE_VEC_ELT (argvec, 0) = arg;
20049 return lookup_template_class (std_init_list, argvec, NULL_TREE,
20050 NULL_TREE, 0, tf_warning_or_error);
20053 /* Replace auto in TYPE with std::initializer_list<auto>. */
20056 listify_autos (tree type, tree auto_node)
20058 tree init_auto = listify (auto_node);
20059 tree argvec = make_tree_vec (1);
20060 TREE_VEC_ELT (argvec, 0) = init_auto;
20061 if (processing_template_decl)
20062 argvec = add_to_template_args (current_template_args (), argvec);
20063 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
20066 /* walk_tree helper for do_auto_deduction. */
20069 contains_auto_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
20072 /* Is this a variable with the type we're looking for? */
20074 && TREE_TYPE (*tp) == type)
20080 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
20081 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
20084 do_auto_deduction (tree type, tree init, tree auto_node)
20086 tree parms, tparms, targs;
20091 if (processing_template_decl
20092 && (TREE_TYPE (init) == NULL_TREE
20093 || BRACE_ENCLOSED_INITIALIZER_P (init)))
20094 /* Not enough information to try this yet. */
20097 /* The name of the object being declared shall not appear in the
20098 initializer expression. */
20099 decl = cp_walk_tree_without_duplicates (&init, contains_auto_r, type);
20102 error ("variable %q#D with %<auto%> type used in its own "
20103 "initializer", decl);
20104 return error_mark_node;
20107 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
20108 with either a new invented type template parameter U or, if the
20109 initializer is a braced-init-list (8.5.4), with
20110 std::initializer_list<U>. */
20111 if (BRACE_ENCLOSED_INITIALIZER_P (init))
20112 type = listify_autos (type, auto_node);
20114 init = resolve_nondeduced_context (init);
20116 parms = build_tree_list (NULL_TREE, type);
20118 tparms = make_tree_vec (1);
20119 targs = make_tree_vec (1);
20120 TREE_VEC_ELT (tparms, 0)
20121 = build_tree_list (NULL_TREE, TYPE_NAME (auto_node));
20122 val = type_unification_real (tparms, targs, parms, args, 1, 0,
20123 DEDUCE_CALL, LOOKUP_NORMAL,
20124 /*explain_p=*/false);
20127 if (processing_template_decl)
20128 /* Try again at instantiation time. */
20130 if (type && type != error_mark_node)
20131 /* If type is error_mark_node a diagnostic must have been
20132 emitted by now. Also, having a mention to '<type error>'
20133 in the diagnostic is not really useful to the user. */
20134 error ("unable to deduce %qT from %qE", type, init);
20135 return error_mark_node;
20138 /* If the list of declarators contains more than one declarator, the type
20139 of each declared variable is determined as described above. If the
20140 type deduced for the template parameter U is not the same in each
20141 deduction, the program is ill-formed. */
20142 if (TREE_TYPE (auto_node)
20143 && !same_type_p (TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0)))
20145 error ("inconsistent deduction for %qT: %qT and then %qT",
20146 auto_node, TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0));
20147 return error_mark_node;
20149 TREE_TYPE (auto_node) = TREE_VEC_ELT (targs, 0);
20151 if (processing_template_decl)
20152 targs = add_to_template_args (current_template_args (), targs);
20153 return tsubst (type, targs, tf_warning_or_error, NULL_TREE);
20156 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
20160 splice_late_return_type (tree type, tree late_return_type)
20164 if (late_return_type == NULL_TREE)
20166 argvec = make_tree_vec (1);
20167 TREE_VEC_ELT (argvec, 0) = late_return_type;
20168 if (processing_template_parmlist)
20169 /* For a late-specified return type in a template type-parameter, we
20170 need to add a dummy argument level for its parmlist. */
20171 argvec = add_to_template_args
20172 (make_tree_vec (processing_template_parmlist), argvec);
20173 if (current_template_parms)
20174 argvec = add_to_template_args (current_template_args (), argvec);
20175 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
20178 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto'. */
20181 is_auto (const_tree type)
20183 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
20184 && TYPE_IDENTIFIER (type) == get_identifier ("auto"))
20190 /* Returns true iff TYPE contains a use of 'auto'. Since auto can only
20191 appear as a type-specifier for the declaration in question, we don't
20192 have to look through the whole type. */
20195 type_uses_auto (tree type)
20197 enum tree_code code;
20198 if (is_auto (type))
20201 code = TREE_CODE (type);
20203 if (code == POINTER_TYPE || code == REFERENCE_TYPE
20204 || code == OFFSET_TYPE || code == FUNCTION_TYPE
20205 || code == METHOD_TYPE || code == ARRAY_TYPE)
20206 return type_uses_auto (TREE_TYPE (type));
20208 if (TYPE_PTRMEMFUNC_P (type))
20209 return type_uses_auto (TREE_TYPE (TREE_TYPE
20210 (TYPE_PTRMEMFUNC_FN_TYPE (type))));
20215 /* For a given template T, return the vector of typedefs referenced
20216 in T for which access check is needed at T instantiation time.
20217 T is either a FUNCTION_DECL or a RECORD_TYPE.
20218 Those typedefs were added to T by the function
20219 append_type_to_template_for_access_check. */
20221 VEC(qualified_typedef_usage_t,gc)*
20222 get_types_needing_access_check (tree t)
20225 VEC(qualified_typedef_usage_t,gc) *result = NULL;
20227 if (!t || t == error_mark_node)
20230 if (!(ti = get_template_info (t)))
20233 if (CLASS_TYPE_P (t)
20234 || TREE_CODE (t) == FUNCTION_DECL)
20236 if (!TI_TEMPLATE (ti))
20239 result = TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti);
20245 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
20246 tied to T. That list of typedefs will be access checked at
20247 T instantiation time.
20248 T is either a FUNCTION_DECL or a RECORD_TYPE.
20249 TYPE_DECL is a TYPE_DECL node representing a typedef.
20250 SCOPE is the scope through which TYPE_DECL is accessed.
20251 LOCATION is the location of the usage point of TYPE_DECL.
20253 This function is a subroutine of
20254 append_type_to_template_for_access_check. */
20257 append_type_to_template_for_access_check_1 (tree t,
20260 location_t location)
20262 qualified_typedef_usage_t typedef_usage;
20265 if (!t || t == error_mark_node)
20268 gcc_assert ((TREE_CODE (t) == FUNCTION_DECL
20269 || CLASS_TYPE_P (t))
20271 && TREE_CODE (type_decl) == TYPE_DECL
20274 if (!(ti = get_template_info (t)))
20277 gcc_assert (TI_TEMPLATE (ti));
20279 typedef_usage.typedef_decl = type_decl;
20280 typedef_usage.context = scope;
20281 typedef_usage.locus = location;
20283 VEC_safe_push (qualified_typedef_usage_t, gc,
20284 TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti),
20288 /* Append TYPE_DECL to the template TEMPL.
20289 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
20290 At TEMPL instanciation time, TYPE_DECL will be checked to see
20291 if it can be accessed through SCOPE.
20292 LOCATION is the location of the usage point of TYPE_DECL.
20294 e.g. consider the following code snippet:
20301 template<class U> struct S
20303 C::myint mi; // <-- usage point of the typedef C::myint
20308 At S<char> instantiation time, we need to check the access of C::myint
20309 In other words, we need to check the access of the myint typedef through
20310 the C scope. For that purpose, this function will add the myint typedef
20311 and the scope C through which its being accessed to a list of typedefs
20312 tied to the template S. That list will be walked at template instantiation
20313 time and access check performed on each typedefs it contains.
20314 Note that this particular code snippet should yield an error because
20315 myint is private to C. */
20318 append_type_to_template_for_access_check (tree templ,
20321 location_t location)
20323 qualified_typedef_usage_t *iter;
20326 gcc_assert (type_decl && (TREE_CODE (type_decl) == TYPE_DECL));
20328 /* Make sure we don't append the type to the template twice. */
20329 FOR_EACH_VEC_ELT (qualified_typedef_usage_t,
20330 get_types_needing_access_check (templ),
20332 if (iter->typedef_decl == type_decl && scope == iter->context)
20335 append_type_to_template_for_access_check_1 (templ, type_decl,
20339 /* Set up the hash tables for template instantiations. */
20342 init_template_processing (void)
20344 decl_specializations = htab_create_ggc (37,
20345 hash_specialization,
20346 eq_specializations,
20348 type_specializations = htab_create_ggc (37,
20349 hash_specialization,
20350 eq_specializations,
20354 /* Print stats about the template hash tables for -fstats. */
20357 print_template_statistics (void)
20359 fprintf (stderr, "decl_specializations: size %ld, %ld elements, "
20360 "%f collisions\n", (long) htab_size (decl_specializations),
20361 (long) htab_elements (decl_specializations),
20362 htab_collisions (decl_specializations));
20363 fprintf (stderr, "type_specializations: size %ld, %ld elements, "
20364 "%f collisions\n", (long) htab_size (type_specializations),
20365 (long) htab_elements (type_specializations),
20366 htab_collisions (type_specializations));
20369 #include "gt-cp-pt.h"