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 Free Software Foundation, Inc.
4 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
5 Rewritten by Jason Merrill (jason@cygnus.com).
7 This file is part of GCC.
9 GCC is free software; you can redistribute it and/or modify
10 it under the terms of the GNU General Public License as published by
11 the Free Software Foundation; either version 3, or (at your option)
14 GCC is distributed in the hope that it will be useful,
15 but WITHOUT ANY WARRANTY; without even the implied warranty of
16 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 GNU General Public License for more details.
19 You should have received a copy of the GNU General Public License
20 along with GCC; see the file COPYING3. If not see
21 <http://www.gnu.org/licenses/>. */
23 /* Known bugs or deficiencies include:
25 all methods must be provided in header files; can't use a source
26 file that contains only the method templates and "just win". */
30 #include "coretypes.h"
34 #include "pointer-set.h"
38 #include "cp-objcp-common.h"
39 #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 pending_template GTY (()) {
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 /* Contains canonical template parameter types. The vector is indexed by
85 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
86 TREE_LIST, whose TREE_VALUEs contain the canonical template
87 parameters of various types and levels. */
88 static GTY(()) VEC(tree,gc) *canonical_template_parms;
90 #define UNIFY_ALLOW_NONE 0
91 #define UNIFY_ALLOW_MORE_CV_QUAL 1
92 #define UNIFY_ALLOW_LESS_CV_QUAL 2
93 #define UNIFY_ALLOW_DERIVED 4
94 #define UNIFY_ALLOW_INTEGER 8
95 #define UNIFY_ALLOW_OUTER_LEVEL 16
96 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
97 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
99 static void push_access_scope (tree);
100 static void pop_access_scope (tree);
101 static bool resolve_overloaded_unification (tree, tree, tree, tree,
102 unification_kind_t, int);
103 static int try_one_overload (tree, tree, tree, tree, tree,
104 unification_kind_t, int, bool);
105 static int unify (tree, tree, tree, tree, int);
106 static void add_pending_template (tree);
107 static int push_tinst_level (tree);
108 static void pop_tinst_level (void);
109 static tree reopen_tinst_level (struct tinst_level *);
110 static tree tsubst_initializer_list (tree, tree);
111 static tree get_class_bindings (tree, tree, tree);
112 static tree coerce_template_parms (tree, tree, tree, tsubst_flags_t,
114 static void tsubst_enum (tree, tree, tree);
115 static tree add_to_template_args (tree, tree);
116 static tree add_outermost_template_args (tree, tree);
117 static bool check_instantiated_args (tree, tree, tsubst_flags_t);
118 static int maybe_adjust_types_for_deduction (unification_kind_t, tree*, tree*,
120 static int type_unification_real (tree, tree, tree, tree,
121 int, unification_kind_t, int);
122 static void note_template_header (int);
123 static tree convert_nontype_argument_function (tree, tree);
124 static tree convert_nontype_argument (tree, tree);
125 static tree convert_template_argument (tree, tree, tree,
126 tsubst_flags_t, int, tree);
127 static int for_each_template_parm (tree, tree_fn_t, void*,
128 struct pointer_set_t*, bool);
129 static tree expand_template_argument_pack (tree);
130 static tree build_template_parm_index (int, int, int, tree, tree);
131 static bool inline_needs_template_parms (tree);
132 static void push_inline_template_parms_recursive (tree, int);
133 static tree retrieve_local_specialization (tree);
134 static void register_local_specialization (tree, tree);
135 static tree reduce_template_parm_level (tree, tree, int, tree, tsubst_flags_t);
136 static int mark_template_parm (tree, void *);
137 static int template_parm_this_level_p (tree, void *);
138 static tree tsubst_friend_function (tree, tree);
139 static tree tsubst_friend_class (tree, tree);
140 static int can_complete_type_without_circularity (tree);
141 static tree get_bindings (tree, tree, tree, bool);
142 static int template_decl_level (tree);
143 static int check_cv_quals_for_unify (int, tree, tree);
144 static void template_parm_level_and_index (tree, int*, int*);
145 static int unify_pack_expansion (tree, tree, tree, tree, int, bool, bool);
146 static tree tsubst_template_arg (tree, tree, tsubst_flags_t, tree);
147 static tree tsubst_template_args (tree, tree, tsubst_flags_t, tree);
148 static tree tsubst_template_parms (tree, tree, tsubst_flags_t);
149 static void regenerate_decl_from_template (tree, tree);
150 static tree most_specialized_class (tree, tree);
151 static tree tsubst_aggr_type (tree, tree, tsubst_flags_t, tree, int);
152 static tree tsubst_arg_types (tree, tree, tsubst_flags_t, tree);
153 static tree tsubst_function_type (tree, tree, tsubst_flags_t, tree);
154 static bool check_specialization_scope (void);
155 static tree process_partial_specialization (tree);
156 static void set_current_access_from_decl (tree);
157 static tree get_template_base (tree, tree, tree, tree);
158 static tree try_class_unification (tree, tree, tree, tree);
159 static int coerce_template_template_parms (tree, tree, tsubst_flags_t,
161 static bool template_template_parm_bindings_ok_p (tree, tree);
162 static int template_args_equal (tree, tree);
163 static void tsubst_default_arguments (tree);
164 static tree for_each_template_parm_r (tree *, int *, void *);
165 static tree copy_default_args_to_explicit_spec_1 (tree, tree);
166 static void copy_default_args_to_explicit_spec (tree);
167 static int invalid_nontype_parm_type_p (tree, tsubst_flags_t);
168 static int eq_local_specializations (const void *, const void *);
169 static bool dependent_template_arg_p (tree);
170 static bool any_template_arguments_need_structural_equality_p (tree);
171 static bool dependent_type_p_r (tree);
172 static tree tsubst (tree, tree, tsubst_flags_t, tree);
173 static tree tsubst_expr (tree, tree, tsubst_flags_t, tree, bool);
174 static tree tsubst_copy (tree, tree, tsubst_flags_t, tree);
175 static tree tsubst_pack_expansion (tree, tree, tsubst_flags_t, tree);
177 /* Make the current scope suitable for access checking when we are
178 processing T. T can be FUNCTION_DECL for instantiated function
179 template, or VAR_DECL for static member variable (need by
180 instantiate_decl). */
183 push_access_scope (tree t)
185 gcc_assert (TREE_CODE (t) == FUNCTION_DECL
186 || TREE_CODE (t) == VAR_DECL);
188 if (DECL_FRIEND_CONTEXT (t))
189 push_nested_class (DECL_FRIEND_CONTEXT (t));
190 else if (DECL_CLASS_SCOPE_P (t))
191 push_nested_class (DECL_CONTEXT (t));
193 push_to_top_level ();
195 if (TREE_CODE (t) == FUNCTION_DECL)
197 saved_access_scope = tree_cons
198 (NULL_TREE, current_function_decl, saved_access_scope);
199 current_function_decl = t;
203 /* Restore the scope set up by push_access_scope. T is the node we
207 pop_access_scope (tree t)
209 if (TREE_CODE (t) == FUNCTION_DECL)
211 current_function_decl = TREE_VALUE (saved_access_scope);
212 saved_access_scope = TREE_CHAIN (saved_access_scope);
215 if (DECL_FRIEND_CONTEXT (t) || DECL_CLASS_SCOPE_P (t))
218 pop_from_top_level ();
221 /* Do any processing required when DECL (a member template
222 declaration) is finished. Returns the TEMPLATE_DECL corresponding
223 to DECL, unless it is a specialization, in which case the DECL
224 itself is returned. */
227 finish_member_template_decl (tree decl)
229 if (decl == error_mark_node)
230 return error_mark_node;
232 gcc_assert (DECL_P (decl));
234 if (TREE_CODE (decl) == TYPE_DECL)
238 type = TREE_TYPE (decl);
239 if (type == error_mark_node)
240 return error_mark_node;
241 if (MAYBE_CLASS_TYPE_P (type)
242 && CLASSTYPE_TEMPLATE_INFO (type)
243 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
245 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
246 check_member_template (tmpl);
251 else if (TREE_CODE (decl) == FIELD_DECL)
252 error ("data member %qD cannot be a member template", decl);
253 else if (DECL_TEMPLATE_INFO (decl))
255 if (!DECL_TEMPLATE_SPECIALIZATION (decl))
257 check_member_template (DECL_TI_TEMPLATE (decl));
258 return DECL_TI_TEMPLATE (decl);
264 error ("invalid member template declaration %qD", decl);
266 return error_mark_node;
269 /* Return the template info node corresponding to T, whatever T is. */
272 get_template_info (tree t)
274 tree tinfo = NULL_TREE;
276 if (DECL_P (t) && DECL_LANG_SPECIFIC (t))
277 tinfo = DECL_TEMPLATE_INFO (t);
279 if (!tinfo && TREE_CODE (t) == TYPE_DECL)
282 if (TAGGED_TYPE_P (t))
283 tinfo = TYPE_TEMPLATE_INFO (t);
288 /* Returns the template nesting level of the indicated class TYPE.
298 A<T>::B<U> has depth two, while A<T> has depth one.
299 Both A<T>::B<int> and A<int>::B<U> have depth one, if
300 they are instantiations, not specializations.
302 This function is guaranteed to return 0 if passed NULL_TREE so
303 that, for example, `template_class_depth (current_class_type)' is
307 template_class_depth (tree type)
312 type && TREE_CODE (type) != NAMESPACE_DECL;
313 type = (TREE_CODE (type) == FUNCTION_DECL)
314 ? CP_DECL_CONTEXT (type) : TYPE_CONTEXT (type))
316 tree tinfo = get_template_info (type);
318 if (tinfo && PRIMARY_TEMPLATE_P (TI_TEMPLATE (tinfo))
319 && uses_template_parms (INNERMOST_TEMPLATE_ARGS (TI_ARGS (tinfo))))
326 /* Subroutine of maybe_begin_member_template_processing.
327 Returns true if processing DECL needs us to push template parms. */
330 inline_needs_template_parms (tree decl)
332 if (! DECL_TEMPLATE_INFO (decl))
335 return (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (most_general_template (decl)))
336 > (processing_template_decl + DECL_TEMPLATE_SPECIALIZATION (decl)));
339 /* Subroutine of maybe_begin_member_template_processing.
340 Push the template parms in PARMS, starting from LEVELS steps into the
341 chain, and ending at the beginning, since template parms are listed
345 push_inline_template_parms_recursive (tree parmlist, int levels)
347 tree parms = TREE_VALUE (parmlist);
351 push_inline_template_parms_recursive (TREE_CHAIN (parmlist), levels - 1);
353 ++processing_template_decl;
354 current_template_parms
355 = tree_cons (size_int (processing_template_decl),
356 parms, current_template_parms);
357 TEMPLATE_PARMS_FOR_INLINE (current_template_parms) = 1;
359 begin_scope (TREE_VEC_LENGTH (parms) ? sk_template_parms : sk_template_spec,
361 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
363 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
365 if (parm == error_mark_node)
368 gcc_assert (DECL_P (parm));
370 switch (TREE_CODE (parm))
379 /* Make a CONST_DECL as is done in process_template_parm.
380 It is ugly that we recreate this here; the original
381 version built in process_template_parm is no longer
383 tree decl = build_decl (CONST_DECL, DECL_NAME (parm),
385 DECL_ARTIFICIAL (decl) = 1;
386 TREE_CONSTANT (decl) = 1;
387 TREE_READONLY (decl) = 1;
388 DECL_INITIAL (decl) = DECL_INITIAL (parm);
389 SET_DECL_TEMPLATE_PARM_P (decl);
400 /* Restore the template parameter context for a member template or
401 a friend template defined in a class definition. */
404 maybe_begin_member_template_processing (tree decl)
409 if (inline_needs_template_parms (decl))
411 parms = DECL_TEMPLATE_PARMS (most_general_template (decl));
412 levels = TMPL_PARMS_DEPTH (parms) - processing_template_decl;
414 if (DECL_TEMPLATE_SPECIALIZATION (decl))
417 parms = TREE_CHAIN (parms);
420 push_inline_template_parms_recursive (parms, levels);
423 /* Remember how many levels of template parameters we pushed so that
424 we can pop them later. */
425 VEC_safe_push (int, heap, inline_parm_levels, levels);
428 /* Undo the effects of maybe_begin_member_template_processing. */
431 maybe_end_member_template_processing (void)
436 if (VEC_length (int, inline_parm_levels) == 0)
439 last = VEC_pop (int, inline_parm_levels);
440 for (i = 0; i < last; ++i)
442 --processing_template_decl;
443 current_template_parms = TREE_CHAIN (current_template_parms);
448 /* Return a new template argument vector which contains all of ARGS,
449 but has as its innermost set of arguments the EXTRA_ARGS. */
452 add_to_template_args (tree args, tree extra_args)
459 extra_depth = TMPL_ARGS_DEPTH (extra_args);
460 new_args = make_tree_vec (TMPL_ARGS_DEPTH (args) + extra_depth);
462 for (i = 1; i <= TMPL_ARGS_DEPTH (args); ++i)
463 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (args, i));
465 for (j = 1; j <= extra_depth; ++j, ++i)
466 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (extra_args, j));
471 /* Like add_to_template_args, but only the outermost ARGS are added to
472 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
473 (EXTRA_ARGS) levels are added. This function is used to combine
474 the template arguments from a partial instantiation with the
475 template arguments used to attain the full instantiation from the
476 partial instantiation. */
479 add_outermost_template_args (tree args, tree extra_args)
483 /* If there are more levels of EXTRA_ARGS than there are ARGS,
484 something very fishy is going on. */
485 gcc_assert (TMPL_ARGS_DEPTH (args) >= TMPL_ARGS_DEPTH (extra_args));
487 /* If *all* the new arguments will be the EXTRA_ARGS, just return
489 if (TMPL_ARGS_DEPTH (args) == TMPL_ARGS_DEPTH (extra_args))
492 /* For the moment, we make ARGS look like it contains fewer levels. */
493 TREE_VEC_LENGTH (args) -= TMPL_ARGS_DEPTH (extra_args);
495 new_args = add_to_template_args (args, extra_args);
497 /* Now, we restore ARGS to its full dimensions. */
498 TREE_VEC_LENGTH (args) += TMPL_ARGS_DEPTH (extra_args);
503 /* Return the N levels of innermost template arguments from the ARGS. */
506 get_innermost_template_args (tree args, int n)
514 /* If N is 1, just return the innermost set of template arguments. */
516 return TMPL_ARGS_LEVEL (args, TMPL_ARGS_DEPTH (args));
518 /* If we're not removing anything, just return the arguments we were
520 extra_levels = TMPL_ARGS_DEPTH (args) - n;
521 gcc_assert (extra_levels >= 0);
522 if (extra_levels == 0)
525 /* Make a new set of arguments, not containing the outer arguments. */
526 new_args = make_tree_vec (n);
527 for (i = 1; i <= n; ++i)
528 SET_TMPL_ARGS_LEVEL (new_args, i,
529 TMPL_ARGS_LEVEL (args, i + extra_levels));
534 /* The inverse of get_innermost_template_args: Return all but the innermost
535 EXTRA_LEVELS levels of template arguments from the ARGS. */
538 strip_innermost_template_args (tree args, int extra_levels)
541 int n = TMPL_ARGS_DEPTH (args) - extra_levels;
546 /* If N is 1, just return the outermost set of template arguments. */
548 return TMPL_ARGS_LEVEL (args, 1);
550 /* If we're not removing anything, just return the arguments we were
552 gcc_assert (extra_levels >= 0);
553 if (extra_levels == 0)
556 /* Make a new set of arguments, not containing the inner arguments. */
557 new_args = make_tree_vec (n);
558 for (i = 1; i <= n; ++i)
559 SET_TMPL_ARGS_LEVEL (new_args, i,
560 TMPL_ARGS_LEVEL (args, i));
565 /* We've got a template header coming up; push to a new level for storing
569 begin_template_parm_list (void)
571 /* We use a non-tag-transparent scope here, which causes pushtag to
572 put tags in this scope, rather than in the enclosing class or
573 namespace scope. This is the right thing, since we want
574 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
575 global template class, push_template_decl handles putting the
576 TEMPLATE_DECL into top-level scope. For a nested template class,
579 template <class T> struct S1 {
580 template <class T> struct S2 {};
583 pushtag contains special code to call pushdecl_with_scope on the
584 TEMPLATE_DECL for S2. */
585 begin_scope (sk_template_parms, NULL);
586 ++processing_template_decl;
587 ++processing_template_parmlist;
588 note_template_header (0);
591 /* This routine is called when a specialization is declared. If it is
592 invalid to declare a specialization here, an error is reported and
593 false is returned, otherwise this routine will return true. */
596 check_specialization_scope (void)
598 tree scope = current_scope ();
602 An explicit specialization shall be declared in the namespace of
603 which the template is a member, or, for member templates, in the
604 namespace of which the enclosing class or enclosing class
605 template is a member. An explicit specialization of a member
606 function, member class or static data member of a class template
607 shall be declared in the namespace of which the class template
609 if (scope && TREE_CODE (scope) != NAMESPACE_DECL)
611 error ("explicit specialization in non-namespace scope %qD", scope);
617 In an explicit specialization declaration for a member of a class
618 template or a member template that appears in namespace scope,
619 the member template and some of its enclosing class templates may
620 remain unspecialized, except that the declaration shall not
621 explicitly specialize a class member template if its enclosing
622 class templates are not explicitly specialized as well. */
623 if (current_template_parms)
625 error ("enclosing class templates are not explicitly specialized");
632 /* We've just seen template <>. */
635 begin_specialization (void)
637 begin_scope (sk_template_spec, NULL);
638 note_template_header (1);
639 return check_specialization_scope ();
642 /* Called at then end of processing a declaration preceded by
646 end_specialization (void)
649 reset_specialization ();
652 /* Any template <>'s that we have seen thus far are not referring to a
653 function specialization. */
656 reset_specialization (void)
658 processing_specialization = 0;
659 template_header_count = 0;
662 /* We've just seen a template header. If SPECIALIZATION is nonzero,
663 it was of the form template <>. */
666 note_template_header (int specialization)
668 processing_specialization = specialization;
669 template_header_count++;
672 /* We're beginning an explicit instantiation. */
675 begin_explicit_instantiation (void)
677 gcc_assert (!processing_explicit_instantiation);
678 processing_explicit_instantiation = true;
683 end_explicit_instantiation (void)
685 gcc_assert (processing_explicit_instantiation);
686 processing_explicit_instantiation = false;
689 /* An explicit specialization or partial specialization TMPL is being
690 declared. Check that the namespace in which the specialization is
691 occurring is permissible. Returns false iff it is invalid to
692 specialize TMPL in the current namespace. */
695 check_specialization_namespace (tree tmpl)
697 tree tpl_ns = decl_namespace_context (tmpl);
701 An explicit specialization shall be declared in the namespace of
702 which the template is a member, or, for member templates, in the
703 namespace of which the enclosing class or enclosing class
704 template is a member. An explicit specialization of a member
705 function, member class or static data member of a class template
706 shall be declared in the namespace of which the class template is
708 if (is_associated_namespace (current_namespace, tpl_ns))
709 /* Same or super-using namespace. */
713 permerror (input_location, "specialization of %qD in different namespace", tmpl);
714 permerror (input_location, " from definition of %q+#D", tmpl);
719 /* SPEC is an explicit instantiation. Check that it is valid to
720 perform this explicit instantiation in the current namespace. */
723 check_explicit_instantiation_namespace (tree spec)
727 /* DR 275: An explicit instantiation shall appear in an enclosing
728 namespace of its template. */
729 ns = decl_namespace_context (spec);
730 if (!is_ancestor (current_namespace, ns))
731 permerror (input_location, "explicit instantiation of %qD in namespace %qD "
732 "(which does not enclose namespace %qD)",
733 spec, current_namespace, ns);
736 /* The TYPE is being declared. If it is a template type, that means it
737 is a partial specialization. Do appropriate error-checking. */
740 maybe_process_partial_specialization (tree type)
744 if (type == error_mark_node)
745 return error_mark_node;
747 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
749 error ("name of class shadows template template parameter %qD",
751 return error_mark_node;
754 context = TYPE_CONTEXT (type);
756 if (CLASS_TYPE_P (type) && CLASSTYPE_USE_TEMPLATE (type))
758 /* This is for ordinary explicit specialization and partial
759 specialization of a template class such as:
761 template <> class C<int>;
765 template <class T> class C<T*>;
767 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
769 if (CLASSTYPE_IMPLICIT_INSTANTIATION (type)
770 && !COMPLETE_TYPE_P (type))
772 check_specialization_namespace (CLASSTYPE_TI_TEMPLATE (type));
773 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
774 if (processing_template_decl)
776 if (push_template_decl (TYPE_MAIN_DECL (type))
778 return error_mark_node;
781 else if (CLASSTYPE_TEMPLATE_INSTANTIATION (type))
782 error ("specialization of %qT after instantiation", type);
784 else if (CLASS_TYPE_P (type)
785 && !CLASSTYPE_USE_TEMPLATE (type)
786 && CLASSTYPE_TEMPLATE_INFO (type)
787 && context && CLASS_TYPE_P (context)
788 && CLASSTYPE_TEMPLATE_INFO (context))
790 /* This is for an explicit specialization of member class
791 template according to [temp.expl.spec/18]:
793 template <> template <class U> class C<int>::D;
795 The context `C<int>' must be an implicit instantiation.
796 Otherwise this is just a member class template declared
799 template <> class C<int> { template <class U> class D; };
800 template <> template <class U> class C<int>::D;
802 In the first case, `C<int>::D' is a specialization of `C<T>::D'
803 while in the second case, `C<int>::D' is a primary template
804 and `C<T>::D' may not exist. */
806 if (CLASSTYPE_IMPLICIT_INSTANTIATION (context)
807 && !COMPLETE_TYPE_P (type))
811 if (current_namespace
812 != decl_namespace_context (CLASSTYPE_TI_TEMPLATE (type)))
814 permerror (input_location, "specializing %q#T in different namespace", type);
815 permerror (input_location, " from definition of %q+#D",
816 CLASSTYPE_TI_TEMPLATE (type));
819 /* Check for invalid specialization after instantiation:
821 template <> template <> class C<int>::D<int>;
822 template <> template <class U> class C<int>::D; */
824 for (t = DECL_TEMPLATE_INSTANTIATIONS
825 (most_general_template (CLASSTYPE_TI_TEMPLATE (type)));
826 t; t = TREE_CHAIN (t))
827 if (TREE_VALUE (t) != type
828 && TYPE_CONTEXT (TREE_VALUE (t)) == context)
829 error ("specialization %qT after instantiation %qT",
830 type, TREE_VALUE (t));
832 /* Mark TYPE as a specialization. And as a result, we only
833 have one level of template argument for the innermost
835 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
836 CLASSTYPE_TI_ARGS (type)
837 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type));
840 else if (processing_specialization)
842 error ("explicit specialization of non-template %qT", type);
843 return error_mark_node;
849 /* Returns nonzero if we can optimize the retrieval of specializations
850 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
851 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
854 optimize_specialization_lookup_p (tree tmpl)
856 return (DECL_FUNCTION_TEMPLATE_P (tmpl)
857 && DECL_CLASS_SCOPE_P (tmpl)
858 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
860 && CLASS_TYPE_P (DECL_CONTEXT (tmpl))
861 /* The optimized lookup depends on the fact that the
862 template arguments for the member function template apply
863 purely to the containing class, which is not true if the
864 containing class is an explicit or partial
866 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (tmpl))
867 && !DECL_MEMBER_TEMPLATE_P (tmpl)
868 && !DECL_CONV_FN_P (tmpl)
869 /* It is possible to have a template that is not a member
870 template and is not a member of a template class:
872 template <typename T>
873 struct S { friend A::f(); };
875 Here, the friend function is a template, but the context does
876 not have template information. The optimized lookup relies
877 on having ARGS be the template arguments for both the class
878 and the function template. */
879 && !DECL_FRIEND_P (DECL_TEMPLATE_RESULT (tmpl)));
882 /* Retrieve the specialization (in the sense of [temp.spec] - a
883 specialization is either an instantiation or an explicit
884 specialization) of TMPL for the given template ARGS. If there is
885 no such specialization, return NULL_TREE. The ARGS are a vector of
886 arguments, or a vector of vectors of arguments, in the case of
887 templates with more than one level of parameters.
889 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
890 then we search for a partial specialization matching ARGS. This
891 parameter is ignored if TMPL is not a class template. */
894 retrieve_specialization (tree tmpl, tree args,
895 bool class_specializations_p)
897 if (args == error_mark_node)
900 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
902 /* There should be as many levels of arguments as there are
903 levels of parameters. */
904 gcc_assert (TMPL_ARGS_DEPTH (args)
905 == TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl)));
907 if (optimize_specialization_lookup_p (tmpl))
910 tree class_specialization;
911 VEC(tree,gc) *methods;
915 /* The template arguments actually apply to the containing
916 class. Find the class specialization with those
918 class_template = CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (tmpl));
920 = retrieve_specialization (class_template, args,
921 /*class_specializations_p=*/false);
922 if (!class_specialization)
924 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
925 for the specialization. */
926 idx = class_method_index_for_fn (class_specialization, tmpl);
929 /* Iterate through the methods with the indicated name, looking
930 for the one that has an instance of TMPL. */
931 methods = CLASSTYPE_METHOD_VEC (class_specialization);
932 for (fns = VEC_index (tree, methods, idx); fns; fns = OVL_NEXT (fns))
934 tree fn = OVL_CURRENT (fns);
935 if (DECL_TEMPLATE_INFO (fn) && DECL_TI_TEMPLATE (fn) == tmpl)
945 /* Class templates store their instantiations on the
946 DECL_TEMPLATE_INSTANTIATIONS list; other templates use the
947 DECL_TEMPLATE_SPECIALIZATIONS list. */
948 if (!class_specializations_p
949 && TREE_CODE (DECL_TEMPLATE_RESULT (tmpl)) == TYPE_DECL
950 && TAGGED_TYPE_P (TREE_TYPE (tmpl)))
951 sp = &DECL_TEMPLATE_INSTANTIATIONS (tmpl);
953 sp = &DECL_TEMPLATE_SPECIALIZATIONS (tmpl);
955 /* Iterate through the list until we find a matching template. */
956 while (*sp != NULL_TREE)
960 if (comp_template_args (TREE_PURPOSE (spec), args))
962 /* Use the move-to-front heuristic to speed up future
966 *sp = TREE_CHAIN (*sp);
967 TREE_CHAIN (spec) = *head;
970 return TREE_VALUE (spec);
972 sp = &TREE_CHAIN (spec);
979 /* Like retrieve_specialization, but for local declarations. */
982 retrieve_local_specialization (tree tmpl)
986 if (local_specializations == NULL)
989 spec = (tree) htab_find_with_hash (local_specializations, tmpl,
990 htab_hash_pointer (tmpl));
991 return spec ? TREE_PURPOSE (spec) : NULL_TREE;
994 /* Returns nonzero iff DECL is a specialization of TMPL. */
997 is_specialization_of (tree decl, tree tmpl)
1001 if (TREE_CODE (decl) == FUNCTION_DECL)
1005 t = DECL_TEMPLATE_INFO (t) ? DECL_TI_TEMPLATE (t) : NULL_TREE)
1011 gcc_assert (TREE_CODE (decl) == TYPE_DECL);
1013 for (t = TREE_TYPE (decl);
1015 t = CLASSTYPE_USE_TEMPLATE (t)
1016 ? TREE_TYPE (CLASSTYPE_TI_TEMPLATE (t)) : NULL_TREE)
1017 if (same_type_ignoring_top_level_qualifiers_p (t, TREE_TYPE (tmpl)))
1024 /* Returns nonzero iff DECL is a specialization of friend declaration
1025 FRIEND_DECL according to [temp.friend]. */
1028 is_specialization_of_friend (tree decl, tree friend_decl)
1030 bool need_template = true;
1033 gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
1034 || TREE_CODE (decl) == TYPE_DECL);
1036 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1037 of a template class, we want to check if DECL is a specialization
1039 if (TREE_CODE (friend_decl) == FUNCTION_DECL
1040 && DECL_TEMPLATE_INFO (friend_decl)
1041 && !DECL_USE_TEMPLATE (friend_decl))
1043 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1044 friend_decl = DECL_TI_TEMPLATE (friend_decl);
1045 need_template = false;
1047 else if (TREE_CODE (friend_decl) == TEMPLATE_DECL
1048 && !PRIMARY_TEMPLATE_P (friend_decl))
1049 need_template = false;
1051 /* There is nothing to do if this is not a template friend. */
1052 if (TREE_CODE (friend_decl) != TEMPLATE_DECL)
1055 if (is_specialization_of (decl, friend_decl))
1059 A member of a class template may be declared to be a friend of a
1060 non-template class. In this case, the corresponding member of
1061 every specialization of the class template is a friend of the
1062 class granting friendship.
1064 For example, given a template friend declaration
1066 template <class T> friend void A<T>::f();
1068 the member function below is considered a friend
1070 template <> struct A<int> {
1074 For this type of template friend, TEMPLATE_DEPTH below will be
1075 nonzero. To determine if DECL is a friend of FRIEND, we first
1076 check if the enclosing class is a specialization of another. */
1078 template_depth = template_class_depth (DECL_CONTEXT (friend_decl));
1080 && DECL_CLASS_SCOPE_P (decl)
1081 && is_specialization_of (TYPE_NAME (DECL_CONTEXT (decl)),
1082 CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (friend_decl))))
1084 /* Next, we check the members themselves. In order to handle
1085 a few tricky cases, such as when FRIEND_DECL's are
1087 template <class T> friend void A<T>::g(T t);
1088 template <class T> template <T t> friend void A<T>::h();
1092 void A<int>::g(int);
1093 template <int> void A<int>::h();
1095 we need to figure out ARGS, the template arguments from
1096 the context of DECL. This is required for template substitution
1097 of `T' in the function parameter of `g' and template parameter
1098 of `h' in the above examples. Here ARGS corresponds to `int'. */
1100 tree context = DECL_CONTEXT (decl);
1101 tree args = NULL_TREE;
1102 int current_depth = 0;
1104 while (current_depth < template_depth)
1106 if (CLASSTYPE_TEMPLATE_INFO (context))
1108 if (current_depth == 0)
1109 args = TYPE_TI_ARGS (context);
1111 args = add_to_template_args (TYPE_TI_ARGS (context), args);
1114 context = TYPE_CONTEXT (context);
1117 if (TREE_CODE (decl) == FUNCTION_DECL)
1122 tree friend_args_type;
1123 tree decl_args_type;
1125 /* Make sure that both DECL and FRIEND_DECL are templates or
1127 is_template = DECL_TEMPLATE_INFO (decl)
1128 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (decl));
1129 if (need_template ^ is_template)
1131 else if (is_template)
1133 /* If both are templates, check template parameter list. */
1135 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1137 if (!comp_template_parms
1138 (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (decl)),
1142 decl_type = TREE_TYPE (DECL_TI_TEMPLATE (decl));
1145 decl_type = TREE_TYPE (decl);
1147 friend_type = tsubst_function_type (TREE_TYPE (friend_decl), args,
1148 tf_none, NULL_TREE);
1149 if (friend_type == error_mark_node)
1152 /* Check if return types match. */
1153 if (!same_type_p (TREE_TYPE (decl_type), TREE_TYPE (friend_type)))
1156 /* Check if function parameter types match, ignoring the
1157 `this' parameter. */
1158 friend_args_type = TYPE_ARG_TYPES (friend_type);
1159 decl_args_type = TYPE_ARG_TYPES (decl_type);
1160 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (friend_decl))
1161 friend_args_type = TREE_CHAIN (friend_args_type);
1162 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1163 decl_args_type = TREE_CHAIN (decl_args_type);
1165 return compparms (decl_args_type, friend_args_type);
1169 /* DECL is a TYPE_DECL */
1171 tree decl_type = TREE_TYPE (decl);
1173 /* Make sure that both DECL and FRIEND_DECL are templates or
1176 = CLASSTYPE_TEMPLATE_INFO (decl_type)
1177 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (decl_type));
1179 if (need_template ^ is_template)
1181 else if (is_template)
1184 /* If both are templates, check the name of the two
1185 TEMPLATE_DECL's first because is_friend didn't. */
1186 if (DECL_NAME (CLASSTYPE_TI_TEMPLATE (decl_type))
1187 != DECL_NAME (friend_decl))
1190 /* Now check template parameter list. */
1192 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1194 return comp_template_parms
1195 (DECL_TEMPLATE_PARMS (CLASSTYPE_TI_TEMPLATE (decl_type)),
1199 return (DECL_NAME (decl)
1200 == DECL_NAME (friend_decl));
1206 /* Register the specialization SPEC as a specialization of TMPL with
1207 the indicated ARGS. IS_FRIEND indicates whether the specialization
1208 is actually just a friend declaration. Returns SPEC, or an
1209 equivalent prior declaration, if available. */
1212 register_specialization (tree spec, tree tmpl, tree args, bool is_friend)
1216 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
1218 if (TREE_CODE (spec) == FUNCTION_DECL
1219 && uses_template_parms (DECL_TI_ARGS (spec)))
1220 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1221 register it; we want the corresponding TEMPLATE_DECL instead.
1222 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1223 the more obvious `uses_template_parms (spec)' to avoid problems
1224 with default function arguments. In particular, given
1225 something like this:
1227 template <class T> void f(T t1, T t = T())
1229 the default argument expression is not substituted for in an
1230 instantiation unless and until it is actually needed. */
1233 fn = retrieve_specialization (tmpl, args,
1234 /*class_specializations_p=*/false);
1235 /* We can sometimes try to re-register a specialization that we've
1236 already got. In particular, regenerate_decl_from_template calls
1237 duplicate_decls which will update the specialization list. But,
1238 we'll still get called again here anyhow. It's more convenient
1239 to simply allow this than to try to prevent it. */
1242 else if (fn && DECL_TEMPLATE_SPECIALIZATION (spec))
1244 if (DECL_TEMPLATE_INSTANTIATION (fn))
1247 || DECL_EXPLICIT_INSTANTIATION (fn))
1249 error ("specialization of %qD after instantiation",
1251 return error_mark_node;
1256 /* This situation should occur only if the first
1257 specialization is an implicit instantiation, the
1258 second is an explicit specialization, and the
1259 implicit instantiation has not yet been used. That
1260 situation can occur if we have implicitly
1261 instantiated a member function and then specialized
1264 We can also wind up here if a friend declaration that
1265 looked like an instantiation turns out to be a
1268 template <class T> void foo(T);
1269 class S { friend void foo<>(int) };
1270 template <> void foo(int);
1272 We transform the existing DECL in place so that any
1273 pointers to it become pointers to the updated
1276 If there was a definition for the template, but not
1277 for the specialization, we want this to look as if
1278 there were no definition, and vice versa. */
1279 DECL_INITIAL (fn) = NULL_TREE;
1280 duplicate_decls (spec, fn, is_friend);
1281 /* The call to duplicate_decls will have applied
1284 An explicit specialization of a function template
1285 is inline only if it is explicitly declared to be,
1286 and independently of whether its function template
1289 to the primary function; now copy the inline bits to
1290 the various clones. */
1291 FOR_EACH_CLONE (clone, fn)
1292 DECL_DECLARED_INLINE_P (clone)
1293 = DECL_DECLARED_INLINE_P (fn);
1294 check_specialization_namespace (fn);
1299 else if (DECL_TEMPLATE_SPECIALIZATION (fn))
1301 if (!duplicate_decls (spec, fn, is_friend) && DECL_INITIAL (spec))
1302 /* Dup decl failed, but this is a new definition. Set the
1303 line number so any errors match this new
1305 DECL_SOURCE_LOCATION (fn) = DECL_SOURCE_LOCATION (spec);
1311 /* A specialization must be declared in the same namespace as the
1312 template it is specializing. */
1313 if (DECL_TEMPLATE_SPECIALIZATION (spec)
1314 && !check_specialization_namespace (tmpl))
1315 DECL_CONTEXT (spec) = FROB_CONTEXT (decl_namespace_context (tmpl));
1317 if (!optimize_specialization_lookup_p (tmpl))
1318 DECL_TEMPLATE_SPECIALIZATIONS (tmpl)
1319 = tree_cons (args, spec, DECL_TEMPLATE_SPECIALIZATIONS (tmpl));
1324 /* Unregister the specialization SPEC as a specialization of TMPL.
1325 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1326 if the SPEC was listed as a specialization of TMPL. */
1329 reregister_specialization (tree spec, tree tmpl, tree new_spec)
1333 for (s = &DECL_TEMPLATE_SPECIALIZATIONS (tmpl);
1335 s = &TREE_CHAIN (*s))
1336 if (TREE_VALUE (*s) == spec)
1339 *s = TREE_CHAIN (*s);
1341 TREE_VALUE (*s) = new_spec;
1348 /* Compare an entry in the local specializations hash table P1 (which
1349 is really a pointer to a TREE_LIST) with P2 (which is really a
1353 eq_local_specializations (const void *p1, const void *p2)
1355 return TREE_VALUE ((const_tree) p1) == (const_tree) p2;
1358 /* Hash P1, an entry in the local specializations table. */
1361 hash_local_specialization (const void* p1)
1363 return htab_hash_pointer (TREE_VALUE ((const_tree) p1));
1366 /* Like register_specialization, but for local declarations. We are
1367 registering SPEC, an instantiation of TMPL. */
1370 register_local_specialization (tree spec, tree tmpl)
1374 slot = htab_find_slot_with_hash (local_specializations, tmpl,
1375 htab_hash_pointer (tmpl), INSERT);
1376 *slot = build_tree_list (spec, tmpl);
1379 /* TYPE is a class type. Returns true if TYPE is an explicitly
1380 specialized class. */
1383 explicit_class_specialization_p (tree type)
1385 if (!CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
1387 return !uses_template_parms (CLASSTYPE_TI_ARGS (type));
1390 /* Print the list of candidate FNS in an error message. */
1393 print_candidates (tree fns)
1397 const char *str = "candidates are:";
1399 for (fn = fns; fn != NULL_TREE; fn = TREE_CHAIN (fn))
1403 for (f = TREE_VALUE (fn); f; f = OVL_NEXT (f))
1404 error ("%s %+#D", str, OVL_CURRENT (f));
1409 /* Returns the template (one of the functions given by TEMPLATE_ID)
1410 which can be specialized to match the indicated DECL with the
1411 explicit template args given in TEMPLATE_ID. The DECL may be
1412 NULL_TREE if none is available. In that case, the functions in
1413 TEMPLATE_ID are non-members.
1415 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1416 specialization of a member template.
1418 The TEMPLATE_COUNT is the number of references to qualifying
1419 template classes that appeared in the name of the function. See
1420 check_explicit_specialization for a more accurate description.
1422 TSK indicates what kind of template declaration (if any) is being
1423 declared. TSK_TEMPLATE indicates that the declaration given by
1424 DECL, though a FUNCTION_DECL, has template parameters, and is
1425 therefore a template function.
1427 The template args (those explicitly specified and those deduced)
1428 are output in a newly created vector *TARGS_OUT.
1430 If it is impossible to determine the result, an error message is
1431 issued. The error_mark_node is returned to indicate failure. */
1434 determine_specialization (tree template_id,
1437 int need_member_template,
1443 tree explicit_targs;
1444 tree candidates = NULL_TREE;
1445 /* A TREE_LIST of templates of which DECL may be a specialization.
1446 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1447 corresponding TREE_PURPOSE is the set of template arguments that,
1448 when used to instantiate the template, would produce a function
1449 with the signature of DECL. */
1450 tree templates = NULL_TREE;
1452 struct cp_binding_level *b;
1454 *targs_out = NULL_TREE;
1456 if (template_id == error_mark_node || decl == error_mark_node)
1457 return error_mark_node;
1459 fns = TREE_OPERAND (template_id, 0);
1460 explicit_targs = TREE_OPERAND (template_id, 1);
1462 if (fns == error_mark_node)
1463 return error_mark_node;
1465 /* Check for baselinks. */
1466 if (BASELINK_P (fns))
1467 fns = BASELINK_FUNCTIONS (fns);
1469 if (!is_overloaded_fn (fns))
1471 error ("%qD is not a function template", fns);
1472 return error_mark_node;
1475 /* Count the number of template headers specified for this
1478 for (b = current_binding_level;
1479 b->kind == sk_template_parms;
1483 for (; fns; fns = OVL_NEXT (fns))
1485 tree fn = OVL_CURRENT (fns);
1487 if (TREE_CODE (fn) == TEMPLATE_DECL)
1489 tree decl_arg_types;
1492 /* In case of explicit specialization, we need to check if
1493 the number of template headers appearing in the specialization
1494 is correct. This is usually done in check_explicit_specialization,
1495 but the check done there cannot be exhaustive when specializing
1496 member functions. Consider the following code:
1498 template <> void A<int>::f(int);
1499 template <> template <> void A<int>::f(int);
1501 Assuming that A<int> is not itself an explicit specialization
1502 already, the first line specializes "f" which is a non-template
1503 member function, whilst the second line specializes "f" which
1504 is a template member function. So both lines are syntactically
1505 correct, and check_explicit_specialization does not reject
1508 Here, we can do better, as we are matching the specialization
1509 against the declarations. We count the number of template
1510 headers, and we check if they match TEMPLATE_COUNT + 1
1511 (TEMPLATE_COUNT is the number of qualifying template classes,
1512 plus there must be another header for the member template
1515 Notice that if header_count is zero, this is not a
1516 specialization but rather a template instantiation, so there
1517 is no check we can perform here. */
1518 if (header_count && header_count != template_count + 1)
1521 /* Check that the number of template arguments at the
1522 innermost level for DECL is the same as for FN. */
1523 if (current_binding_level->kind == sk_template_parms
1524 && !current_binding_level->explicit_spec_p
1525 && (TREE_VEC_LENGTH (DECL_INNERMOST_TEMPLATE_PARMS (fn))
1526 != TREE_VEC_LENGTH (INNERMOST_TEMPLATE_PARMS
1527 (current_template_parms))))
1530 /* DECL might be a specialization of FN. */
1531 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1532 fn_arg_types = TYPE_ARG_TYPES (TREE_TYPE (fn));
1534 /* For a non-static member function, we need to make sure
1535 that the const qualification is the same. Since
1536 get_bindings does not try to merge the "this" parameter,
1537 we must do the comparison explicitly. */
1538 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
1539 && !same_type_p (TREE_VALUE (fn_arg_types),
1540 TREE_VALUE (decl_arg_types)))
1543 /* Skip the "this" parameter and, for constructors of
1544 classes with virtual bases, the VTT parameter. A
1545 full specialization of a constructor will have a VTT
1546 parameter, but a template never will. */
1548 = skip_artificial_parms_for (decl, decl_arg_types);
1550 = skip_artificial_parms_for (fn, fn_arg_types);
1552 /* Check that the number of function parameters matches.
1554 template <class T> void f(int i = 0);
1555 template <> void f<int>();
1556 The specialization f<int> is invalid but is not caught
1557 by get_bindings below. */
1558 if (list_length (fn_arg_types) != list_length (decl_arg_types))
1561 /* Function templates cannot be specializations; there are
1562 no partial specializations of functions. Therefore, if
1563 the type of DECL does not match FN, there is no
1565 if (tsk == tsk_template)
1567 if (compparms (fn_arg_types, decl_arg_types))
1568 candidates = tree_cons (NULL_TREE, fn, candidates);
1572 /* See whether this function might be a specialization of this
1574 targs = get_bindings (fn, decl, explicit_targs, /*check_ret=*/true);
1577 /* We cannot deduce template arguments that when used to
1578 specialize TMPL will produce DECL. */
1581 /* Save this template, and the arguments deduced. */
1582 templates = tree_cons (targs, fn, templates);
1584 else if (need_member_template)
1585 /* FN is an ordinary member function, and we need a
1586 specialization of a member template. */
1588 else if (TREE_CODE (fn) != FUNCTION_DECL)
1589 /* We can get IDENTIFIER_NODEs here in certain erroneous
1592 else if (!DECL_FUNCTION_MEMBER_P (fn))
1593 /* This is just an ordinary non-member function. Nothing can
1594 be a specialization of that. */
1596 else if (DECL_ARTIFICIAL (fn))
1597 /* Cannot specialize functions that are created implicitly. */
1601 tree decl_arg_types;
1603 /* This is an ordinary member function. However, since
1604 we're here, we can assume it's enclosing class is a
1605 template class. For example,
1607 template <typename T> struct S { void f(); };
1608 template <> void S<int>::f() {}
1610 Here, S<int>::f is a non-template, but S<int> is a
1611 template class. If FN has the same type as DECL, we
1612 might be in business. */
1614 if (!DECL_TEMPLATE_INFO (fn))
1615 /* Its enclosing class is an explicit specialization
1616 of a template class. This is not a candidate. */
1619 if (!same_type_p (TREE_TYPE (TREE_TYPE (decl)),
1620 TREE_TYPE (TREE_TYPE (fn))))
1621 /* The return types differ. */
1624 /* Adjust the type of DECL in case FN is a static member. */
1625 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1626 if (DECL_STATIC_FUNCTION_P (fn)
1627 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1628 decl_arg_types = TREE_CHAIN (decl_arg_types);
1630 if (compparms (TYPE_ARG_TYPES (TREE_TYPE (fn)),
1633 candidates = tree_cons (NULL_TREE, fn, candidates);
1637 if (templates && TREE_CHAIN (templates))
1643 It is possible for a specialization with a given function
1644 signature to be instantiated from more than one function
1645 template. In such cases, explicit specification of the
1646 template arguments must be used to uniquely identify the
1647 function template specialization being specialized.
1649 Note that here, there's no suggestion that we're supposed to
1650 determine which of the candidate templates is most
1651 specialized. However, we, also have:
1655 Partial ordering of overloaded function template
1656 declarations is used in the following contexts to select
1657 the function template to which a function template
1658 specialization refers:
1660 -- when an explicit specialization refers to a function
1663 So, we do use the partial ordering rules, at least for now.
1664 This extension can only serve to make invalid programs valid,
1665 so it's safe. And, there is strong anecdotal evidence that
1666 the committee intended the partial ordering rules to apply;
1667 the EDG front end has that behavior, and John Spicer claims
1668 that the committee simply forgot to delete the wording in
1669 [temp.expl.spec]. */
1670 tree tmpl = most_specialized_instantiation (templates);
1671 if (tmpl != error_mark_node)
1674 TREE_CHAIN (templates) = NULL_TREE;
1678 if (templates == NULL_TREE && candidates == NULL_TREE)
1680 error ("template-id %qD for %q+D does not match any template "
1681 "declaration", template_id, decl);
1682 return error_mark_node;
1684 else if ((templates && TREE_CHAIN (templates))
1685 || (candidates && TREE_CHAIN (candidates))
1686 || (templates && candidates))
1688 error ("ambiguous template specialization %qD for %q+D",
1690 chainon (candidates, templates);
1691 print_candidates (candidates);
1692 return error_mark_node;
1695 /* We have one, and exactly one, match. */
1698 tree fn = TREE_VALUE (candidates);
1699 /* DECL is a re-declaration of a template function. */
1700 if (TREE_CODE (fn) == TEMPLATE_DECL)
1702 /* It was a specialization of an ordinary member function in a
1704 *targs_out = copy_node (DECL_TI_ARGS (fn));
1705 return DECL_TI_TEMPLATE (fn);
1708 /* It was a specialization of a template. */
1709 targs = DECL_TI_ARGS (DECL_TEMPLATE_RESULT (TREE_VALUE (templates)));
1710 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (targs))
1712 *targs_out = copy_node (targs);
1713 SET_TMPL_ARGS_LEVEL (*targs_out,
1714 TMPL_ARGS_DEPTH (*targs_out),
1715 TREE_PURPOSE (templates));
1718 *targs_out = TREE_PURPOSE (templates);
1719 return TREE_VALUE (templates);
1722 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
1723 but with the default argument values filled in from those in the
1727 copy_default_args_to_explicit_spec_1 (tree spec_types,
1730 tree new_spec_types;
1735 if (spec_types == void_list_node)
1736 return void_list_node;
1738 /* Substitute into the rest of the list. */
1740 copy_default_args_to_explicit_spec_1 (TREE_CHAIN (spec_types),
1741 TREE_CHAIN (tmpl_types));
1743 /* Add the default argument for this parameter. */
1744 return hash_tree_cons (TREE_PURPOSE (tmpl_types),
1745 TREE_VALUE (spec_types),
1749 /* DECL is an explicit specialization. Replicate default arguments
1750 from the template it specializes. (That way, code like:
1752 template <class T> void f(T = 3);
1753 template <> void f(double);
1756 works, as required.) An alternative approach would be to look up
1757 the correct default arguments at the call-site, but this approach
1758 is consistent with how implicit instantiations are handled. */
1761 copy_default_args_to_explicit_spec (tree decl)
1766 tree new_spec_types;
1770 tree object_type = NULL_TREE;
1771 tree in_charge = NULL_TREE;
1772 tree vtt = NULL_TREE;
1774 /* See if there's anything we need to do. */
1775 tmpl = DECL_TI_TEMPLATE (decl);
1776 tmpl_types = TYPE_ARG_TYPES (TREE_TYPE (DECL_TEMPLATE_RESULT (tmpl)));
1777 for (t = tmpl_types; t; t = TREE_CHAIN (t))
1778 if (TREE_PURPOSE (t))
1783 old_type = TREE_TYPE (decl);
1784 spec_types = TYPE_ARG_TYPES (old_type);
1786 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1788 /* Remove the this pointer, but remember the object's type for
1790 object_type = TREE_TYPE (TREE_VALUE (spec_types));
1791 spec_types = TREE_CHAIN (spec_types);
1792 tmpl_types = TREE_CHAIN (tmpl_types);
1794 if (DECL_HAS_IN_CHARGE_PARM_P (decl))
1796 /* DECL may contain more parameters than TMPL due to the extra
1797 in-charge parameter in constructors and destructors. */
1798 in_charge = spec_types;
1799 spec_types = TREE_CHAIN (spec_types);
1801 if (DECL_HAS_VTT_PARM_P (decl))
1804 spec_types = TREE_CHAIN (spec_types);
1808 /* Compute the merged default arguments. */
1810 copy_default_args_to_explicit_spec_1 (spec_types, tmpl_types);
1812 /* Compute the new FUNCTION_TYPE. */
1816 new_spec_types = hash_tree_cons (TREE_PURPOSE (vtt),
1821 /* Put the in-charge parameter back. */
1822 new_spec_types = hash_tree_cons (TREE_PURPOSE (in_charge),
1823 TREE_VALUE (in_charge),
1826 new_type = build_method_type_directly (object_type,
1827 TREE_TYPE (old_type),
1831 new_type = build_function_type (TREE_TYPE (old_type),
1833 new_type = cp_build_type_attribute_variant (new_type,
1834 TYPE_ATTRIBUTES (old_type));
1835 new_type = build_exception_variant (new_type,
1836 TYPE_RAISES_EXCEPTIONS (old_type));
1837 TREE_TYPE (decl) = new_type;
1840 /* Check to see if the function just declared, as indicated in
1841 DECLARATOR, and in DECL, is a specialization of a function
1842 template. We may also discover that the declaration is an explicit
1843 instantiation at this point.
1845 Returns DECL, or an equivalent declaration that should be used
1846 instead if all goes well. Issues an error message if something is
1847 amiss. Returns error_mark_node if the error is not easily
1850 FLAGS is a bitmask consisting of the following flags:
1852 2: The function has a definition.
1853 4: The function is a friend.
1855 The TEMPLATE_COUNT is the number of references to qualifying
1856 template classes that appeared in the name of the function. For
1859 template <class T> struct S { void f(); };
1862 the TEMPLATE_COUNT would be 1. However, explicitly specialized
1863 classes are not counted in the TEMPLATE_COUNT, so that in
1865 template <class T> struct S {};
1866 template <> struct S<int> { void f(); }
1867 template <> void S<int>::f();
1869 the TEMPLATE_COUNT would be 0. (Note that this declaration is
1870 invalid; there should be no template <>.)
1872 If the function is a specialization, it is marked as such via
1873 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
1874 is set up correctly, and it is added to the list of specializations
1875 for that template. */
1878 check_explicit_specialization (tree declarator,
1883 int have_def = flags & 2;
1884 int is_friend = flags & 4;
1885 int specialization = 0;
1886 int explicit_instantiation = 0;
1887 int member_specialization = 0;
1888 tree ctype = DECL_CLASS_CONTEXT (decl);
1889 tree dname = DECL_NAME (decl);
1894 if (!processing_specialization)
1897 tsk = tsk_excessive_parms;
1900 tsk = current_tmpl_spec_kind (template_count);
1905 if (processing_specialization)
1908 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
1910 else if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
1913 /* This could be something like:
1915 template <class T> void f(T);
1916 class S { friend void f<>(int); } */
1920 /* This case handles bogus declarations like template <>
1921 template <class T> void f<int>(); */
1923 error ("template-id %qD in declaration of primary template",
1930 case tsk_invalid_member_spec:
1931 /* The error has already been reported in
1932 check_specialization_scope. */
1933 return error_mark_node;
1935 case tsk_invalid_expl_inst:
1936 error ("template parameter list used in explicit instantiation");
1942 error ("definition provided for explicit instantiation");
1944 explicit_instantiation = 1;
1947 case tsk_excessive_parms:
1948 case tsk_insufficient_parms:
1949 if (tsk == tsk_excessive_parms)
1950 error ("too many template parameter lists in declaration of %qD",
1952 else if (template_header_count)
1953 error("too few template parameter lists in declaration of %qD", decl);
1955 error("explicit specialization of %qD must be introduced by "
1956 "%<template <>%>", decl);
1960 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
1962 member_specialization = 1;
1968 if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
1970 /* This case handles bogus declarations like template <>
1971 template <class T> void f<int>(); */
1973 if (uses_template_parms (declarator))
1974 error ("function template partial specialization %qD "
1975 "is not allowed", declarator);
1977 error ("template-id %qD in declaration of primary template",
1982 if (ctype && CLASSTYPE_TEMPLATE_INSTANTIATION (ctype))
1983 /* This is a specialization of a member template, without
1984 specialization the containing class. Something like:
1986 template <class T> struct S {
1987 template <class U> void f (U);
1989 template <> template <class U> void S<int>::f(U) {}
1991 That's a specialization -- but of the entire template. */
1999 if (specialization || member_specialization)
2001 tree t = TYPE_ARG_TYPES (TREE_TYPE (decl));
2002 for (; t; t = TREE_CHAIN (t))
2003 if (TREE_PURPOSE (t))
2005 permerror (input_location,
2006 "default argument specified in explicit specialization");
2011 if (specialization || member_specialization || explicit_instantiation)
2013 tree tmpl = NULL_TREE;
2014 tree targs = NULL_TREE;
2016 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2017 if (TREE_CODE (declarator) != TEMPLATE_ID_EXPR)
2021 gcc_assert (TREE_CODE (declarator) == IDENTIFIER_NODE);
2026 /* If there is no class context, the explicit instantiation
2027 must be at namespace scope. */
2028 gcc_assert (DECL_NAMESPACE_SCOPE_P (decl));
2030 /* Find the namespace binding, using the declaration
2032 fns = lookup_qualified_name (CP_DECL_CONTEXT (decl), dname,
2034 if (fns == error_mark_node || !is_overloaded_fn (fns))
2036 error ("%qD is not a template function", dname);
2037 fns = error_mark_node;
2041 tree fn = OVL_CURRENT (fns);
2042 if (!is_associated_namespace (CP_DECL_CONTEXT (decl),
2043 CP_DECL_CONTEXT (fn)))
2044 error ("%qD is not declared in %qD",
2045 decl, current_namespace);
2049 declarator = lookup_template_function (fns, NULL_TREE);
2052 if (declarator == error_mark_node)
2053 return error_mark_node;
2055 if (ctype != NULL_TREE && TYPE_BEING_DEFINED (ctype))
2057 if (!explicit_instantiation)
2058 /* A specialization in class scope. This is invalid,
2059 but the error will already have been flagged by
2060 check_specialization_scope. */
2061 return error_mark_node;
2064 /* It's not valid to write an explicit instantiation in
2067 class C { template void f(); }
2069 This case is caught by the parser. However, on
2072 template class C { void f(); };
2074 (which is invalid) we can get here. The error will be
2081 else if (ctype != NULL_TREE
2082 && (TREE_CODE (TREE_OPERAND (declarator, 0)) ==
2085 /* Find the list of functions in ctype that have the same
2086 name as the declared function. */
2087 tree name = TREE_OPERAND (declarator, 0);
2088 tree fns = NULL_TREE;
2091 if (constructor_name_p (name, ctype))
2093 int is_constructor = DECL_CONSTRUCTOR_P (decl);
2095 if (is_constructor ? !TYPE_HAS_USER_CONSTRUCTOR (ctype)
2096 : !CLASSTYPE_DESTRUCTORS (ctype))
2098 /* From [temp.expl.spec]:
2100 If such an explicit specialization for the member
2101 of a class template names an implicitly-declared
2102 special member function (clause _special_), the
2103 program is ill-formed.
2105 Similar language is found in [temp.explicit]. */
2106 error ("specialization of implicitly-declared special member function");
2107 return error_mark_node;
2110 name = is_constructor ? ctor_identifier : dtor_identifier;
2113 if (!DECL_CONV_FN_P (decl))
2115 idx = lookup_fnfields_1 (ctype, name);
2117 fns = VEC_index (tree, CLASSTYPE_METHOD_VEC (ctype), idx);
2121 VEC(tree,gc) *methods;
2124 /* For a type-conversion operator, we cannot do a
2125 name-based lookup. We might be looking for `operator
2126 int' which will be a specialization of `operator T'.
2127 So, we find *all* the conversion operators, and then
2128 select from them. */
2131 methods = CLASSTYPE_METHOD_VEC (ctype);
2133 for (idx = CLASSTYPE_FIRST_CONVERSION_SLOT;
2134 VEC_iterate (tree, methods, idx, ovl);
2137 if (!DECL_CONV_FN_P (OVL_CURRENT (ovl)))
2138 /* There are no more conversion functions. */
2141 /* Glue all these conversion functions together
2142 with those we already have. */
2143 for (; ovl; ovl = OVL_NEXT (ovl))
2144 fns = ovl_cons (OVL_CURRENT (ovl), fns);
2148 if (fns == NULL_TREE)
2150 error ("no member function %qD declared in %qT", name, ctype);
2151 return error_mark_node;
2154 TREE_OPERAND (declarator, 0) = fns;
2157 /* Figure out what exactly is being specialized at this point.
2158 Note that for an explicit instantiation, even one for a
2159 member function, we cannot tell apriori whether the
2160 instantiation is for a member template, or just a member
2161 function of a template class. Even if a member template is
2162 being instantiated, the member template arguments may be
2163 elided if they can be deduced from the rest of the
2165 tmpl = determine_specialization (declarator, decl,
2167 member_specialization,
2171 if (!tmpl || tmpl == error_mark_node)
2172 /* We couldn't figure out what this declaration was
2174 return error_mark_node;
2177 tree gen_tmpl = most_general_template (tmpl);
2179 if (explicit_instantiation)
2181 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2182 is done by do_decl_instantiation later. */
2184 int arg_depth = TMPL_ARGS_DEPTH (targs);
2185 int parm_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
2187 if (arg_depth > parm_depth)
2189 /* If TMPL is not the most general template (for
2190 example, if TMPL is a friend template that is
2191 injected into namespace scope), then there will
2192 be too many levels of TARGS. Remove some of them
2197 new_targs = make_tree_vec (parm_depth);
2198 for (i = arg_depth - parm_depth; i < arg_depth; ++i)
2199 TREE_VEC_ELT (new_targs, i - (arg_depth - parm_depth))
2200 = TREE_VEC_ELT (targs, i);
2204 return instantiate_template (tmpl, targs, tf_error);
2207 /* If we thought that the DECL was a member function, but it
2208 turns out to be specializing a static member function,
2209 make DECL a static member function as well. */
2210 if (DECL_STATIC_FUNCTION_P (tmpl)
2211 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2212 revert_static_member_fn (decl);
2214 /* If this is a specialization of a member template of a
2215 template class, we want to return the TEMPLATE_DECL, not
2216 the specialization of it. */
2217 if (tsk == tsk_template)
2219 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
2220 DECL_INITIAL (DECL_TEMPLATE_RESULT (tmpl)) = NULL_TREE;
2223 DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl);
2224 DECL_SOURCE_LOCATION (DECL_TEMPLATE_RESULT (tmpl))
2225 = DECL_SOURCE_LOCATION (decl);
2226 /* We want to use the argument list specified in the
2227 definition, not in the original declaration. */
2228 DECL_ARGUMENTS (DECL_TEMPLATE_RESULT (tmpl))
2229 = DECL_ARGUMENTS (decl);
2234 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2235 DECL_TEMPLATE_INFO (decl) = tree_cons (tmpl, targs, NULL_TREE);
2237 /* Inherit default function arguments from the template
2238 DECL is specializing. */
2239 copy_default_args_to_explicit_spec (decl);
2241 /* This specialization has the same protection as the
2242 template it specializes. */
2243 TREE_PRIVATE (decl) = TREE_PRIVATE (gen_tmpl);
2244 TREE_PROTECTED (decl) = TREE_PROTECTED (gen_tmpl);
2246 /* 7.1.1-1 [dcl.stc]
2248 A storage-class-specifier shall not be specified in an
2249 explicit specialization...
2251 The parser rejects these, so unless action is taken here,
2252 explicit function specializations will always appear with
2255 The action recommended by the C++ CWG in response to C++
2256 defect report 605 is to make the storage class and linkage
2257 of the explicit specialization match the templated function:
2259 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2261 if (tsk == tsk_expl_spec && DECL_FUNCTION_TEMPLATE_P (gen_tmpl))
2263 tree tmpl_func = DECL_TEMPLATE_RESULT (gen_tmpl);
2264 gcc_assert (TREE_CODE (tmpl_func) == FUNCTION_DECL);
2266 /* This specialization has the same linkage and visibility as
2267 the function template it specializes. */
2268 TREE_PUBLIC (decl) = TREE_PUBLIC (tmpl_func);
2269 if (! TREE_PUBLIC (decl))
2271 DECL_INTERFACE_KNOWN (decl) = 1;
2272 DECL_NOT_REALLY_EXTERN (decl) = 1;
2274 DECL_THIS_STATIC (decl) = DECL_THIS_STATIC (tmpl_func);
2275 if (DECL_VISIBILITY_SPECIFIED (tmpl_func))
2277 DECL_VISIBILITY_SPECIFIED (decl) = 1;
2278 DECL_VISIBILITY (decl) = DECL_VISIBILITY (tmpl_func);
2282 /* If DECL is a friend declaration, declared using an
2283 unqualified name, the namespace associated with DECL may
2284 have been set incorrectly. For example, in:
2286 template <typename T> void f(T);
2288 struct S { friend void f<int>(int); }
2291 we will have set the DECL_CONTEXT for the friend
2292 declaration to N, rather than to the global namespace. */
2293 if (DECL_NAMESPACE_SCOPE_P (decl))
2294 DECL_CONTEXT (decl) = DECL_CONTEXT (tmpl);
2296 if (is_friend && !have_def)
2297 /* This is not really a declaration of a specialization.
2298 It's just the name of an instantiation. But, it's not
2299 a request for an instantiation, either. */
2300 SET_DECL_IMPLICIT_INSTANTIATION (decl);
2301 else if (DECL_CONSTRUCTOR_P (decl) || DECL_DESTRUCTOR_P (decl))
2302 /* This is indeed a specialization. In case of constructors
2303 and destructors, we need in-charge and not-in-charge
2304 versions in V3 ABI. */
2305 clone_function_decl (decl, /*update_method_vec_p=*/0);
2307 /* Register this specialization so that we can find it
2309 decl = register_specialization (decl, gen_tmpl, targs, is_friend);
2316 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2317 parameters. These are represented in the same format used for
2318 DECL_TEMPLATE_PARMS. */
2321 comp_template_parms (const_tree parms1, const_tree parms2)
2326 if (parms1 == parms2)
2329 for (p1 = parms1, p2 = parms2;
2330 p1 != NULL_TREE && p2 != NULL_TREE;
2331 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2))
2333 tree t1 = TREE_VALUE (p1);
2334 tree t2 = TREE_VALUE (p2);
2337 gcc_assert (TREE_CODE (t1) == TREE_VEC);
2338 gcc_assert (TREE_CODE (t2) == TREE_VEC);
2340 if (TREE_VEC_LENGTH (t1) != TREE_VEC_LENGTH (t2))
2343 for (i = 0; i < TREE_VEC_LENGTH (t2); ++i)
2345 tree parm1 = TREE_VALUE (TREE_VEC_ELT (t1, i));
2346 tree parm2 = TREE_VALUE (TREE_VEC_ELT (t2, i));
2348 /* If either of the template parameters are invalid, assume
2349 they match for the sake of error recovery. */
2350 if (parm1 == error_mark_node || parm2 == error_mark_node)
2353 if (TREE_CODE (parm1) != TREE_CODE (parm2))
2356 if (TREE_CODE (parm1) == TEMPLATE_TYPE_PARM
2357 && (TEMPLATE_TYPE_PARAMETER_PACK (parm1)
2358 == TEMPLATE_TYPE_PARAMETER_PACK (parm2)))
2360 else if (!same_type_p (TREE_TYPE (parm1), TREE_TYPE (parm2)))
2365 if ((p1 != NULL_TREE) != (p2 != NULL_TREE))
2366 /* One set of parameters has more parameters lists than the
2373 /* Determine whether PARM is a parameter pack. */
2375 template_parameter_pack_p (const_tree parm)
2377 /* Determine if we have a non-type template parameter pack. */
2378 if (TREE_CODE (parm) == PARM_DECL)
2379 return (DECL_TEMPLATE_PARM_P (parm)
2380 && TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)));
2382 /* If this is a list of template parameters, we could get a
2383 TYPE_DECL or a TEMPLATE_DECL. */
2384 if (TREE_CODE (parm) == TYPE_DECL || TREE_CODE (parm) == TEMPLATE_DECL)
2385 parm = TREE_TYPE (parm);
2387 return ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
2388 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM)
2389 && TEMPLATE_TYPE_PARAMETER_PACK (parm));
2392 /* Determine whether ARGS describes a variadic template args list,
2393 i.e., one that is terminated by a template argument pack. */
2395 template_args_variadic_p (tree args)
2400 if (args == NULL_TREE)
2403 args = INNERMOST_TEMPLATE_ARGS (args);
2404 nargs = TREE_VEC_LENGTH (args);
2409 last_parm = TREE_VEC_ELT (args, nargs - 1);
2411 return ARGUMENT_PACK_P (last_parm);
2414 /* Generate a new name for the parameter pack name NAME (an
2415 IDENTIFIER_NODE) that incorporates its */
2417 make_ith_pack_parameter_name (tree name, int i)
2419 /* Munge the name to include the parameter index. */
2423 sprintf(numbuf, "%i", i);
2424 newname = (char*)alloca (IDENTIFIER_LENGTH (name) + strlen(numbuf) + 2);
2425 sprintf(newname, "%s#%i", IDENTIFIER_POINTER (name), i);
2426 return get_identifier (newname);
2429 /* Structure used to track the progress of find_parameter_packs_r. */
2430 struct find_parameter_pack_data
2432 /* TREE_LIST that will contain all of the parameter packs found by
2434 tree* parameter_packs;
2436 /* Set of AST nodes that have been visited by the traversal. */
2437 struct pointer_set_t *visited;
2440 /* Identifies all of the argument packs that occur in a template
2441 argument and appends them to the TREE_LIST inside DATA, which is a
2442 find_parameter_pack_data structure. This is a subroutine of
2443 make_pack_expansion and uses_parameter_packs. */
2445 find_parameter_packs_r (tree *tp, int *walk_subtrees, void* data)
2448 struct find_parameter_pack_data* ppd =
2449 (struct find_parameter_pack_data*)data;
2450 bool parameter_pack_p = false;
2452 /* Identify whether this is a parameter pack or not. */
2453 switch (TREE_CODE (t))
2455 case TEMPLATE_PARM_INDEX:
2456 if (TEMPLATE_PARM_PARAMETER_PACK (t))
2457 parameter_pack_p = true;
2460 case TEMPLATE_TYPE_PARM:
2461 case TEMPLATE_TEMPLATE_PARM:
2462 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
2463 parameter_pack_p = true;
2467 if (FUNCTION_PARAMETER_PACK_P (t))
2469 /* We don't want to walk into the type of a PARM_DECL,
2470 because we don't want to see the type parameter pack. */
2472 parameter_pack_p = true;
2477 /* Not a parameter pack. */
2481 if (parameter_pack_p)
2483 /* Add this parameter pack to the list. */
2484 *ppd->parameter_packs = tree_cons (NULL_TREE, t, *ppd->parameter_packs);
2488 cp_walk_tree (&TYPE_CONTEXT (t),
2489 &find_parameter_packs_r, ppd, ppd->visited);
2491 /* This switch statement will return immediately if we don't find a
2493 switch (TREE_CODE (t))
2495 case TEMPLATE_PARM_INDEX:
2498 case BOUND_TEMPLATE_TEMPLATE_PARM:
2499 /* Check the template itself. */
2500 cp_walk_tree (&TREE_TYPE (TYPE_TI_TEMPLATE (t)),
2501 &find_parameter_packs_r, ppd, ppd->visited);
2502 /* Check the template arguments. */
2503 cp_walk_tree (&TYPE_TI_ARGS (t), &find_parameter_packs_r, ppd,
2508 case TEMPLATE_TYPE_PARM:
2509 case TEMPLATE_TEMPLATE_PARM:
2516 if (TYPE_PTRMEMFUNC_P (t))
2522 if (TYPE_TEMPLATE_INFO (t))
2523 cp_walk_tree (&TREE_VALUE (TYPE_TEMPLATE_INFO (t)),
2524 &find_parameter_packs_r, ppd, ppd->visited);
2530 cp_walk_tree (&TREE_TYPE (t),
2531 &find_parameter_packs_r, ppd, ppd->visited);
2535 cp_walk_tree (&TYPENAME_TYPE_FULLNAME (t), &find_parameter_packs_r,
2540 case TYPE_PACK_EXPANSION:
2541 case EXPR_PACK_EXPANSION:
2546 cp_walk_tree (&TYPE_MAX_VALUE (t), &find_parameter_packs_r,
2551 case IDENTIFIER_NODE:
2552 cp_walk_tree (&TREE_TYPE (t), &find_parameter_packs_r, ppd,
2564 /* Determines if the expression or type T uses any parameter packs. */
2566 uses_parameter_packs (tree t)
2568 tree parameter_packs = NULL_TREE;
2569 struct find_parameter_pack_data ppd;
2570 ppd.parameter_packs = ¶meter_packs;
2571 ppd.visited = pointer_set_create ();
2572 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
2573 pointer_set_destroy (ppd.visited);
2574 return parameter_packs != NULL_TREE;
2577 /* Turn ARG, which may be an expression, type, or a TREE_LIST
2578 representation a base-class initializer into a parameter pack
2579 expansion. If all goes well, the resulting node will be an
2580 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
2583 make_pack_expansion (tree arg)
2586 tree parameter_packs = NULL_TREE;
2587 bool for_types = false;
2588 struct find_parameter_pack_data ppd;
2590 if (!arg || arg == error_mark_node)
2593 if (TREE_CODE (arg) == TREE_LIST)
2595 /* The only time we will see a TREE_LIST here is for a base
2596 class initializer. In this case, the TREE_PURPOSE will be a
2597 _TYPE node (representing the base class expansion we're
2598 initializing) and the TREE_VALUE will be a TREE_LIST
2599 containing the initialization arguments.
2601 The resulting expansion looks somewhat different from most
2602 expansions. Rather than returning just one _EXPANSION, we
2603 return a TREE_LIST whose TREE_PURPOSE is a
2604 TYPE_PACK_EXPANSION containing the bases that will be
2605 initialized. The TREE_VALUE will be identical to the
2606 original TREE_VALUE, which is a list of arguments that will
2607 be passed to each base. We do not introduce any new pack
2608 expansion nodes into the TREE_VALUE (although it is possible
2609 that some already exist), because the TREE_PURPOSE and
2610 TREE_VALUE all need to be expanded together with the same
2611 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
2612 resulting TREE_PURPOSE will mention the parameter packs in
2613 both the bases and the arguments to the bases. */
2616 tree parameter_packs = NULL_TREE;
2618 /* Determine which parameter packs will be used by the base
2620 ppd.visited = pointer_set_create ();
2621 ppd.parameter_packs = ¶meter_packs;
2622 cp_walk_tree (&TREE_PURPOSE (arg), &find_parameter_packs_r,
2625 if (parameter_packs == NULL_TREE)
2627 error ("base initializer expansion %<%T%> contains no parameter packs", arg);
2628 pointer_set_destroy (ppd.visited);
2629 return error_mark_node;
2632 if (TREE_VALUE (arg) != void_type_node)
2634 /* Collect the sets of parameter packs used in each of the
2635 initialization arguments. */
2636 for (value = TREE_VALUE (arg); value; value = TREE_CHAIN (value))
2638 /* Determine which parameter packs will be expanded in this
2640 cp_walk_tree (&TREE_VALUE (value), &find_parameter_packs_r,
2645 pointer_set_destroy (ppd.visited);
2647 /* Create the pack expansion type for the base type. */
2648 purpose = make_node (TYPE_PACK_EXPANSION);
2649 SET_PACK_EXPANSION_PATTERN (purpose, TREE_PURPOSE (arg));
2650 PACK_EXPANSION_PARAMETER_PACKS (purpose) = parameter_packs;
2652 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
2653 they will rarely be compared to anything. */
2654 SET_TYPE_STRUCTURAL_EQUALITY (purpose);
2656 return tree_cons (purpose, TREE_VALUE (arg), NULL_TREE);
2659 if (TYPE_P (arg) || TREE_CODE (arg) == TEMPLATE_DECL)
2662 /* Build the PACK_EXPANSION_* node. */
2663 result = make_node (for_types ? TYPE_PACK_EXPANSION : EXPR_PACK_EXPANSION);
2664 SET_PACK_EXPANSION_PATTERN (result, arg);
2665 if (TREE_CODE (result) == EXPR_PACK_EXPANSION)
2667 /* Propagate type and const-expression information. */
2668 TREE_TYPE (result) = TREE_TYPE (arg);
2669 TREE_CONSTANT (result) = TREE_CONSTANT (arg);
2672 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
2673 they will rarely be compared to anything. */
2674 SET_TYPE_STRUCTURAL_EQUALITY (result);
2676 /* Determine which parameter packs will be expanded. */
2677 ppd.parameter_packs = ¶meter_packs;
2678 ppd.visited = pointer_set_create ();
2679 cp_walk_tree (&arg, &find_parameter_packs_r, &ppd, ppd.visited);
2680 pointer_set_destroy (ppd.visited);
2682 /* Make sure we found some parameter packs. */
2683 if (parameter_packs == NULL_TREE)
2686 error ("expansion pattern %<%T%> contains no argument packs", arg);
2688 error ("expansion pattern %<%E%> contains no argument packs", arg);
2689 return error_mark_node;
2691 PACK_EXPANSION_PARAMETER_PACKS (result) = parameter_packs;
2696 /* Checks T for any "bare" parameter packs, which have not yet been
2697 expanded, and issues an error if any are found. This operation can
2698 only be done on full expressions or types (e.g., an expression
2699 statement, "if" condition, etc.), because we could have expressions like:
2701 foo(f(g(h(args)))...)
2703 where "args" is a parameter pack. check_for_bare_parameter_packs
2704 should not be called for the subexpressions args, h(args),
2705 g(h(args)), or f(g(h(args))), because we would produce erroneous
2708 Returns TRUE and emits an error if there were bare parameter packs,
2709 returns FALSE otherwise. */
2711 check_for_bare_parameter_packs (tree t)
2713 tree parameter_packs = NULL_TREE;
2714 struct find_parameter_pack_data ppd;
2716 if (!processing_template_decl || !t || t == error_mark_node)
2719 if (TREE_CODE (t) == TYPE_DECL)
2722 ppd.parameter_packs = ¶meter_packs;
2723 ppd.visited = pointer_set_create ();
2724 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
2725 pointer_set_destroy (ppd.visited);
2727 if (parameter_packs)
2729 error ("parameter packs not expanded with %<...%>:");
2730 while (parameter_packs)
2732 tree pack = TREE_VALUE (parameter_packs);
2733 tree name = NULL_TREE;
2735 if (TREE_CODE (pack) == TEMPLATE_TYPE_PARM
2736 || TREE_CODE (pack) == TEMPLATE_TEMPLATE_PARM)
2737 name = TYPE_NAME (pack);
2738 else if (TREE_CODE (pack) == TEMPLATE_PARM_INDEX)
2739 name = DECL_NAME (TEMPLATE_PARM_DECL (pack));
2741 name = DECL_NAME (pack);
2744 inform (input_location, " %qD", name);
2746 inform (input_location, " <anonymous>");
2748 parameter_packs = TREE_CHAIN (parameter_packs);
2757 /* Expand any parameter packs that occur in the template arguments in
2760 expand_template_argument_pack (tree args)
2762 tree result_args = NULL_TREE;
2763 int in_arg, out_arg = 0, nargs = args ? TREE_VEC_LENGTH (args) : 0;
2764 int num_result_args = -1;
2766 /* First, determine if we need to expand anything, and the number of
2767 slots we'll need. */
2768 for (in_arg = 0; in_arg < nargs; ++in_arg)
2770 tree arg = TREE_VEC_ELT (args, in_arg);
2771 if (ARGUMENT_PACK_P (arg))
2773 int num_packed = TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg));
2774 if (num_result_args < 0)
2775 num_result_args = in_arg + num_packed;
2777 num_result_args += num_packed;
2781 if (num_result_args >= 0)
2786 /* If no expansion is necessary, we're done. */
2787 if (num_result_args < 0)
2790 /* Expand arguments. */
2791 result_args = make_tree_vec (num_result_args);
2792 for (in_arg = 0; in_arg < nargs; ++in_arg)
2794 tree arg = TREE_VEC_ELT (args, in_arg);
2795 if (ARGUMENT_PACK_P (arg))
2797 tree packed = ARGUMENT_PACK_ARGS (arg);
2798 int i, num_packed = TREE_VEC_LENGTH (packed);
2799 for (i = 0; i < num_packed; ++i, ++out_arg)
2800 TREE_VEC_ELT (result_args, out_arg) = TREE_VEC_ELT(packed, i);
2804 TREE_VEC_ELT (result_args, out_arg) = arg;
2812 /* Checks if DECL shadows a template parameter.
2814 [temp.local]: A template-parameter shall not be redeclared within its
2815 scope (including nested scopes).
2817 Emits an error and returns TRUE if the DECL shadows a parameter,
2818 returns FALSE otherwise. */
2821 check_template_shadow (tree decl)
2825 /* If we're not in a template, we can't possibly shadow a template
2827 if (!current_template_parms)
2830 /* Figure out what we're shadowing. */
2831 if (TREE_CODE (decl) == OVERLOAD)
2832 decl = OVL_CURRENT (decl);
2833 olddecl = innermost_non_namespace_value (DECL_NAME (decl));
2835 /* If there's no previous binding for this name, we're not shadowing
2836 anything, let alone a template parameter. */
2840 /* If we're not shadowing a template parameter, we're done. Note
2841 that OLDDECL might be an OVERLOAD (or perhaps even an
2842 ERROR_MARK), so we can't just blithely assume it to be a _DECL
2844 if (!DECL_P (olddecl) || !DECL_TEMPLATE_PARM_P (olddecl))
2847 /* We check for decl != olddecl to avoid bogus errors for using a
2848 name inside a class. We check TPFI to avoid duplicate errors for
2849 inline member templates. */
2851 || TEMPLATE_PARMS_FOR_INLINE (current_template_parms))
2854 error ("declaration of %q+#D", decl);
2855 error (" shadows template parm %q+#D", olddecl);
2859 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
2860 ORIG_LEVEL, DECL, and TYPE. */
2863 build_template_parm_index (int index,
2869 tree t = make_node (TEMPLATE_PARM_INDEX);
2870 TEMPLATE_PARM_IDX (t) = index;
2871 TEMPLATE_PARM_LEVEL (t) = level;
2872 TEMPLATE_PARM_ORIG_LEVEL (t) = orig_level;
2873 TEMPLATE_PARM_DECL (t) = decl;
2874 TREE_TYPE (t) = type;
2875 TREE_CONSTANT (t) = TREE_CONSTANT (decl);
2876 TREE_READONLY (t) = TREE_READONLY (decl);
2881 /* Find the canonical type parameter for the given template type
2882 parameter. Returns the canonical type parameter, which may be TYPE
2883 if no such parameter existed. */
2885 canonical_type_parameter (tree type)
2888 int idx = TEMPLATE_TYPE_IDX (type);
2889 if (!canonical_template_parms)
2890 canonical_template_parms = VEC_alloc (tree, gc, idx+1);
2892 while (VEC_length (tree, canonical_template_parms) <= (unsigned)idx)
2893 VEC_safe_push (tree, gc, canonical_template_parms, NULL_TREE);
2895 list = VEC_index (tree, canonical_template_parms, idx);
2896 while (list && !comptypes (type, TREE_VALUE (list), COMPARE_STRUCTURAL))
2897 list = TREE_CHAIN (list);
2900 return TREE_VALUE (list);
2903 VEC_replace(tree, canonical_template_parms, idx,
2904 tree_cons (NULL_TREE, type,
2905 VEC_index (tree, canonical_template_parms, idx)));
2910 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
2911 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
2912 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
2913 new one is created. */
2916 reduce_template_parm_level (tree index, tree type, int levels, tree args,
2917 tsubst_flags_t complain)
2919 if (TEMPLATE_PARM_DESCENDANTS (index) == NULL_TREE
2920 || (TEMPLATE_PARM_LEVEL (TEMPLATE_PARM_DESCENDANTS (index))
2921 != TEMPLATE_PARM_LEVEL (index) - levels))
2923 tree orig_decl = TEMPLATE_PARM_DECL (index);
2926 decl = build_decl (TREE_CODE (orig_decl), DECL_NAME (orig_decl), type);
2927 TREE_CONSTANT (decl) = TREE_CONSTANT (orig_decl);
2928 TREE_READONLY (decl) = TREE_READONLY (orig_decl);
2929 DECL_ARTIFICIAL (decl) = 1;
2930 SET_DECL_TEMPLATE_PARM_P (decl);
2932 t = build_template_parm_index (TEMPLATE_PARM_IDX (index),
2933 TEMPLATE_PARM_LEVEL (index) - levels,
2934 TEMPLATE_PARM_ORIG_LEVEL (index),
2936 TEMPLATE_PARM_DESCENDANTS (index) = t;
2937 TEMPLATE_PARM_PARAMETER_PACK (t)
2938 = TEMPLATE_PARM_PARAMETER_PACK (index);
2940 /* Template template parameters need this. */
2941 if (TREE_CODE (decl) == TEMPLATE_DECL)
2942 DECL_TEMPLATE_PARMS (decl) = tsubst_template_parms
2943 (DECL_TEMPLATE_PARMS (TEMPLATE_PARM_DECL (index)),
2947 return TEMPLATE_PARM_DESCENDANTS (index);
2950 /* Process information from new template parameter PARM and append it to the
2951 LIST being built. This new parameter is a non-type parameter iff
2952 IS_NON_TYPE is true. This new parameter is a parameter
2953 pack iff IS_PARAMETER_PACK is true. */
2956 process_template_parm (tree list, tree parm, bool is_non_type,
2957 bool is_parameter_pack)
2964 gcc_assert (TREE_CODE (parm) == TREE_LIST);
2965 defval = TREE_PURPOSE (parm);
2969 tree p = tree_last (list);
2971 if (p && TREE_VALUE (p) != error_mark_node)
2974 if (TREE_CODE (p) == TYPE_DECL || TREE_CODE (p) == TEMPLATE_DECL)
2975 idx = TEMPLATE_TYPE_IDX (TREE_TYPE (p));
2977 idx = TEMPLATE_PARM_IDX (DECL_INITIAL (p));
2987 parm = TREE_VALUE (parm);
2989 SET_DECL_TEMPLATE_PARM_P (parm);
2991 if (TREE_TYPE (parm) == error_mark_node)
2993 err_parm_list = build_tree_list (defval, parm);
2994 TREE_VALUE (err_parm_list) = error_mark_node;
2995 return chainon (list, err_parm_list);
3001 The top-level cv-qualifiers on the template-parameter are
3002 ignored when determining its type. */
3003 TREE_TYPE (parm) = TYPE_MAIN_VARIANT (TREE_TYPE (parm));
3004 if (invalid_nontype_parm_type_p (TREE_TYPE (parm), 1))
3006 err_parm_list = build_tree_list (defval, parm);
3007 TREE_VALUE (err_parm_list) = error_mark_node;
3008 return chainon (list, err_parm_list);
3011 if (uses_parameter_packs (TREE_TYPE (parm)) && !is_parameter_pack)
3013 /* This template parameter is not a parameter pack, but it
3014 should be. Complain about "bare" parameter packs. */
3015 check_for_bare_parameter_packs (TREE_TYPE (parm));
3017 /* Recover by calling this a parameter pack. */
3018 is_parameter_pack = true;
3022 /* A template parameter is not modifiable. */
3023 TREE_CONSTANT (parm) = 1;
3024 TREE_READONLY (parm) = 1;
3025 decl = build_decl (CONST_DECL, DECL_NAME (parm), TREE_TYPE (parm));
3026 TREE_CONSTANT (decl) = 1;
3027 TREE_READONLY (decl) = 1;
3028 DECL_INITIAL (parm) = DECL_INITIAL (decl)
3029 = build_template_parm_index (idx, processing_template_decl,
3030 processing_template_decl,
3031 decl, TREE_TYPE (parm));
3033 TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))
3034 = is_parameter_pack;
3039 parm = TREE_VALUE (TREE_VALUE (parm));
3041 if (parm && TREE_CODE (parm) == TEMPLATE_DECL)
3043 t = cxx_make_type (TEMPLATE_TEMPLATE_PARM);
3044 /* This is for distinguishing between real templates and template
3045 template parameters */
3046 TREE_TYPE (parm) = t;
3047 TREE_TYPE (DECL_TEMPLATE_RESULT (parm)) = t;
3052 t = cxx_make_type (TEMPLATE_TYPE_PARM);
3053 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3054 decl = build_decl (TYPE_DECL, parm, t);
3057 TYPE_NAME (t) = decl;
3058 TYPE_STUB_DECL (t) = decl;
3060 TEMPLATE_TYPE_PARM_INDEX (t)
3061 = build_template_parm_index (idx, processing_template_decl,
3062 processing_template_decl,
3063 decl, TREE_TYPE (parm));
3064 TEMPLATE_TYPE_PARAMETER_PACK (t) = is_parameter_pack;
3065 TYPE_CANONICAL (t) = canonical_type_parameter (t);
3067 DECL_ARTIFICIAL (decl) = 1;
3068 SET_DECL_TEMPLATE_PARM_P (decl);
3070 parm = build_tree_list (defval, parm);
3071 return chainon (list, parm);
3074 /* The end of a template parameter list has been reached. Process the
3075 tree list into a parameter vector, converting each parameter into a more
3076 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3080 end_template_parm_list (tree parms)
3084 tree saved_parmlist = make_tree_vec (list_length (parms));
3086 current_template_parms
3087 = tree_cons (size_int (processing_template_decl),
3088 saved_parmlist, current_template_parms);
3090 for (parm = parms, nparms = 0; parm; parm = next, nparms++)
3092 next = TREE_CHAIN (parm);
3093 TREE_VEC_ELT (saved_parmlist, nparms) = parm;
3094 TREE_CHAIN (parm) = NULL_TREE;
3097 --processing_template_parmlist;
3099 return saved_parmlist;
3102 /* end_template_decl is called after a template declaration is seen. */
3105 end_template_decl (void)
3107 reset_specialization ();
3109 if (! processing_template_decl)
3112 /* This matches the pushlevel in begin_template_parm_list. */
3115 --processing_template_decl;
3116 current_template_parms = TREE_CHAIN (current_template_parms);
3119 /* Within the declaration of a template, return all levels of template
3120 parameters that apply. The template parameters are represented as
3121 a TREE_VEC, in the form documented in cp-tree.h for template
3125 current_template_args (void)
3128 tree args = NULL_TREE;
3129 int length = TMPL_PARMS_DEPTH (current_template_parms);
3132 /* If there is only one level of template parameters, we do not
3133 create a TREE_VEC of TREE_VECs. Instead, we return a single
3134 TREE_VEC containing the arguments. */
3136 args = make_tree_vec (length);
3138 for (header = current_template_parms; header; header = TREE_CHAIN (header))
3140 tree a = copy_node (TREE_VALUE (header));
3143 TREE_TYPE (a) = NULL_TREE;
3144 for (i = TREE_VEC_LENGTH (a) - 1; i >= 0; --i)
3146 tree t = TREE_VEC_ELT (a, i);
3148 /* T will be a list if we are called from within a
3149 begin/end_template_parm_list pair, but a vector directly
3150 if within a begin/end_member_template_processing pair. */
3151 if (TREE_CODE (t) == TREE_LIST)
3155 if (!error_operand_p (t))
3157 if (TREE_CODE (t) == TYPE_DECL
3158 || TREE_CODE (t) == TEMPLATE_DECL)
3162 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
3164 /* Turn this argument into a TYPE_ARGUMENT_PACK
3165 with a single element, which expands T. */
3166 tree vec = make_tree_vec (1);
3167 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
3169 t = make_node (TYPE_ARGUMENT_PACK);
3170 SET_ARGUMENT_PACK_ARGS (t, vec);
3175 t = DECL_INITIAL (t);
3177 if (TEMPLATE_PARM_PARAMETER_PACK (t))
3179 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3180 with a single element, which expands T. */
3181 tree vec = make_tree_vec (1);
3182 tree type = TREE_TYPE (TEMPLATE_PARM_DECL (t));
3183 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
3185 t = make_node (NONTYPE_ARGUMENT_PACK);
3186 SET_ARGUMENT_PACK_ARGS (t, vec);
3187 TREE_TYPE (t) = type;
3190 TREE_VEC_ELT (a, i) = t;
3196 TREE_VEC_ELT (args, --l) = a;
3204 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
3205 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
3206 a member template. Used by push_template_decl below. */
3209 build_template_decl (tree decl, tree parms, bool member_template_p)
3211 tree tmpl = build_lang_decl (TEMPLATE_DECL, DECL_NAME (decl), NULL_TREE);
3212 DECL_TEMPLATE_PARMS (tmpl) = parms;
3213 DECL_CONTEXT (tmpl) = DECL_CONTEXT (decl);
3214 DECL_MEMBER_TEMPLATE_P (tmpl) = member_template_p;
3215 if (DECL_LANG_SPECIFIC (decl))
3217 DECL_STATIC_FUNCTION_P (tmpl) = DECL_STATIC_FUNCTION_P (decl);
3218 DECL_CONSTRUCTOR_P (tmpl) = DECL_CONSTRUCTOR_P (decl);
3219 DECL_DESTRUCTOR_P (tmpl) = DECL_DESTRUCTOR_P (decl);
3220 DECL_NONCONVERTING_P (tmpl) = DECL_NONCONVERTING_P (decl);
3221 DECL_ASSIGNMENT_OPERATOR_P (tmpl) = DECL_ASSIGNMENT_OPERATOR_P (decl);
3222 if (DECL_OVERLOADED_OPERATOR_P (decl))
3223 SET_OVERLOADED_OPERATOR_CODE (tmpl,
3224 DECL_OVERLOADED_OPERATOR_P (decl));
3230 struct template_parm_data
3232 /* The level of the template parameters we are currently
3236 /* The index of the specialization argument we are currently
3240 /* An array whose size is the number of template parameters. The
3241 elements are nonzero if the parameter has been used in any one
3242 of the arguments processed so far. */
3245 /* An array whose size is the number of template arguments. The
3246 elements are nonzero if the argument makes use of template
3247 parameters of this level. */
3248 int* arg_uses_template_parms;
3251 /* Subroutine of push_template_decl used to see if each template
3252 parameter in a partial specialization is used in the explicit
3253 argument list. If T is of the LEVEL given in DATA (which is
3254 treated as a template_parm_data*), then DATA->PARMS is marked
3258 mark_template_parm (tree t, void* data)
3262 struct template_parm_data* tpd = (struct template_parm_data*) data;
3264 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
3266 level = TEMPLATE_PARM_LEVEL (t);
3267 idx = TEMPLATE_PARM_IDX (t);
3271 level = TEMPLATE_TYPE_LEVEL (t);
3272 idx = TEMPLATE_TYPE_IDX (t);
3275 if (level == tpd->level)
3277 tpd->parms[idx] = 1;
3278 tpd->arg_uses_template_parms[tpd->current_arg] = 1;
3281 /* Return zero so that for_each_template_parm will continue the
3282 traversal of the tree; we want to mark *every* template parm. */
3286 /* Process the partial specialization DECL. */
3289 process_partial_specialization (tree decl)
3291 tree type = TREE_TYPE (decl);
3292 tree maintmpl = CLASSTYPE_TI_TEMPLATE (type);
3293 tree specargs = CLASSTYPE_TI_ARGS (type);
3294 tree inner_args = INNERMOST_TEMPLATE_ARGS (specargs);
3295 tree main_inner_parms = DECL_INNERMOST_TEMPLATE_PARMS (maintmpl);
3297 int nargs = TREE_VEC_LENGTH (inner_args);
3300 int did_error_intro = 0;
3301 struct template_parm_data tpd;
3302 struct template_parm_data tpd2;
3304 gcc_assert (current_template_parms);
3306 inner_parms = INNERMOST_TEMPLATE_PARMS (current_template_parms);
3307 ntparms = TREE_VEC_LENGTH (inner_parms);
3309 /* We check that each of the template parameters given in the
3310 partial specialization is used in the argument list to the
3311 specialization. For example:
3313 template <class T> struct S;
3314 template <class T> struct S<T*>;
3316 The second declaration is OK because `T*' uses the template
3317 parameter T, whereas
3319 template <class T> struct S<int>;
3321 is no good. Even trickier is:
3332 The S2<T> declaration is actually invalid; it is a
3333 full-specialization. Of course,
3336 struct S2<T (*)(U)>;
3338 or some such would have been OK. */
3339 tpd.level = TMPL_PARMS_DEPTH (current_template_parms);
3340 tpd.parms = (int *) alloca (sizeof (int) * ntparms);
3341 memset (tpd.parms, 0, sizeof (int) * ntparms);
3343 tpd.arg_uses_template_parms = (int *) alloca (sizeof (int) * nargs);
3344 memset (tpd.arg_uses_template_parms, 0, sizeof (int) * nargs);
3345 for (i = 0; i < nargs; ++i)
3347 tpd.current_arg = i;
3348 for_each_template_parm (TREE_VEC_ELT (inner_args, i),
3349 &mark_template_parm,
3352 /*include_nondeduced_p=*/false);
3354 for (i = 0; i < ntparms; ++i)
3355 if (tpd.parms[i] == 0)
3357 /* One of the template parms was not used in the
3359 if (!did_error_intro)
3361 error ("template parameters not used in partial specialization:");
3362 did_error_intro = 1;
3365 error (" %qD", TREE_VALUE (TREE_VEC_ELT (inner_parms, i)));
3368 /* [temp.class.spec]
3370 The argument list of the specialization shall not be identical to
3371 the implicit argument list of the primary template. */
3372 if (comp_template_args
3374 INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE
3376 error ("partial specialization %qT does not specialize any template arguments", type);
3378 /* [temp.class.spec]
3380 A partially specialized non-type argument expression shall not
3381 involve template parameters of the partial specialization except
3382 when the argument expression is a simple identifier.
3384 The type of a template parameter corresponding to a specialized
3385 non-type argument shall not be dependent on a parameter of the
3388 Also, we verify that pack expansions only occur at the
3389 end of the argument list. */
3390 gcc_assert (nargs == DECL_NTPARMS (maintmpl));
3392 for (i = 0; i < nargs; ++i)
3394 tree parm = TREE_VALUE (TREE_VEC_ELT (main_inner_parms, i));
3395 tree arg = TREE_VEC_ELT (inner_args, i);
3396 tree packed_args = NULL_TREE;
3399 if (ARGUMENT_PACK_P (arg))
3401 /* Extract the arguments from the argument pack. We'll be
3402 iterating over these in the following loop. */
3403 packed_args = ARGUMENT_PACK_ARGS (arg);
3404 len = TREE_VEC_LENGTH (packed_args);
3407 for (j = 0; j < len; j++)
3410 /* Get the Jth argument in the parameter pack. */
3411 arg = TREE_VEC_ELT (packed_args, j);
3413 if (PACK_EXPANSION_P (arg))
3415 /* Pack expansions must come at the end of the
3417 if ((packed_args && j < len - 1)
3418 || (!packed_args && i < nargs - 1))
3420 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
3421 error ("parameter pack argument %qE must be at the end of the template argument list", arg);
3423 error ("parameter pack argument %qT must be at the end of the template argument list", arg);
3426 TREE_VEC_ELT (packed_args, j) = error_mark_node;
3430 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
3431 /* We only care about the pattern. */
3432 arg = PACK_EXPANSION_PATTERN (arg);
3434 if (/* These first two lines are the `non-type' bit. */
3436 && TREE_CODE (arg) != TEMPLATE_DECL
3437 /* This next line is the `argument expression is not just a
3438 simple identifier' condition and also the `specialized
3439 non-type argument' bit. */
3440 && TREE_CODE (arg) != TEMPLATE_PARM_INDEX)
3442 if ((!packed_args && tpd.arg_uses_template_parms[i])
3443 || (packed_args && uses_template_parms (arg)))
3444 error ("template argument %qE involves template parameter(s)",
3448 /* Look at the corresponding template parameter,
3449 marking which template parameters its type depends
3451 tree type = TREE_TYPE (parm);
3455 /* We haven't yet initialized TPD2. Do so now. */
3456 tpd2.arg_uses_template_parms
3457 = (int *) alloca (sizeof (int) * nargs);
3458 /* The number of parameters here is the number in the
3459 main template, which, as checked in the assertion
3461 tpd2.parms = (int *) alloca (sizeof (int) * nargs);
3463 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (maintmpl));
3466 /* Mark the template parameters. But this time, we're
3467 looking for the template parameters of the main
3468 template, not in the specialization. */
3469 tpd2.current_arg = i;
3470 tpd2.arg_uses_template_parms[i] = 0;
3471 memset (tpd2.parms, 0, sizeof (int) * nargs);
3472 for_each_template_parm (type,
3473 &mark_template_parm,
3476 /*include_nondeduced_p=*/false);
3478 if (tpd2.arg_uses_template_parms [i])
3480 /* The type depended on some template parameters.
3481 If they are fully specialized in the
3482 specialization, that's OK. */
3484 for (j = 0; j < nargs; ++j)
3485 if (tpd2.parms[j] != 0
3486 && tpd.arg_uses_template_parms [j])
3488 error ("type %qT of template argument %qE depends "
3489 "on template parameter(s)",
3500 if (retrieve_specialization (maintmpl, specargs,
3501 /*class_specializations_p=*/true))
3502 /* We've already got this specialization. */
3505 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)
3506 = tree_cons (specargs, inner_parms,
3507 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl));
3508 TREE_TYPE (DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)) = type;
3512 /* Check that a template declaration's use of default arguments and
3513 parameter packs is not invalid. Here, PARMS are the template
3514 parameters. IS_PRIMARY is nonzero if DECL is the thing declared by
3515 a primary template. IS_PARTIAL is nonzero if DECL is a partial
3519 IS_FRIEND_DECL is nonzero if DECL is a friend function template
3520 declaration (but not a definition); 1 indicates a declaration, 2
3521 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
3522 emitted for extraneous default arguments.
3524 Returns TRUE if there were no errors found, FALSE otherwise. */
3527 check_default_tmpl_args (tree decl, tree parms, int is_primary,
3528 int is_partial, int is_friend_decl)
3531 int last_level_to_check;
3533 bool no_errors = true;
3537 A default template-argument shall not be specified in a
3538 function template declaration or a function template definition, nor
3539 in the template-parameter-list of the definition of a member of a
3542 if (TREE_CODE (CP_DECL_CONTEXT (decl)) == FUNCTION_DECL)
3543 /* You can't have a function template declaration in a local
3544 scope, nor you can you define a member of a class template in a
3548 if (current_class_type
3549 && !TYPE_BEING_DEFINED (current_class_type)
3550 && DECL_LANG_SPECIFIC (decl)
3551 /* If this is either a friend defined in the scope of the class
3552 or a member function. */
3553 && (DECL_FUNCTION_MEMBER_P (decl)
3554 ? same_type_p (DECL_CONTEXT (decl), current_class_type)
3555 : DECL_FRIEND_CONTEXT (decl)
3556 ? same_type_p (DECL_FRIEND_CONTEXT (decl), current_class_type)
3558 /* And, if it was a member function, it really was defined in
3559 the scope of the class. */
3560 && (!DECL_FUNCTION_MEMBER_P (decl)
3561 || DECL_INITIALIZED_IN_CLASS_P (decl)))
3562 /* We already checked these parameters when the template was
3563 declared, so there's no need to do it again now. This function
3564 was defined in class scope, but we're processing it's body now
3565 that the class is complete. */
3568 /* Core issue 226 (C++0x only): the following only applies to class
3570 if ((cxx_dialect == cxx98) || TREE_CODE (decl) != FUNCTION_DECL)
3574 If a template-parameter has a default template-argument, all
3575 subsequent template-parameters shall have a default
3576 template-argument supplied. */
3577 for (parm_level = parms; parm_level; parm_level = TREE_CHAIN (parm_level))
3579 tree inner_parms = TREE_VALUE (parm_level);
3580 int ntparms = TREE_VEC_LENGTH (inner_parms);
3581 int seen_def_arg_p = 0;
3584 for (i = 0; i < ntparms; ++i)
3586 tree parm = TREE_VEC_ELT (inner_parms, i);
3588 if (parm == error_mark_node)
3591 if (TREE_PURPOSE (parm))
3593 else if (seen_def_arg_p
3594 && !template_parameter_pack_p (TREE_VALUE (parm)))
3596 error ("no default argument for %qD", TREE_VALUE (parm));
3597 /* For better subsequent error-recovery, we indicate that
3598 there should have been a default argument. */
3599 TREE_PURPOSE (parm) = error_mark_node;
3605 /* Don't complain about an enclosing partial
3607 && parm_level == parms
3608 && TREE_CODE (decl) == TYPE_DECL
3610 && template_parameter_pack_p (TREE_VALUE (parm)))
3612 /* A primary class template can only have one
3613 parameter pack, at the end of the template
3616 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL)
3617 error ("parameter pack %qE must be at the end of the"
3618 " template parameter list", TREE_VALUE (parm));
3620 error ("parameter pack %qT must be at the end of the"
3621 " template parameter list",
3622 TREE_TYPE (TREE_VALUE (parm)));
3624 TREE_VALUE (TREE_VEC_ELT (inner_parms, i))
3632 if (((cxx_dialect == cxx98) && TREE_CODE (decl) != TYPE_DECL)
3636 /* For an ordinary class template, default template arguments are
3637 allowed at the innermost level, e.g.:
3638 template <class T = int>
3640 but, in a partial specialization, they're not allowed even
3641 there, as we have in [temp.class.spec]:
3643 The template parameter list of a specialization shall not
3644 contain default template argument values.
3646 So, for a partial specialization, or for a function template
3647 (in C++98/C++03), we look at all of them. */
3650 /* But, for a primary class template that is not a partial
3651 specialization we look at all template parameters except the
3653 parms = TREE_CHAIN (parms);
3655 /* Figure out what error message to issue. */
3656 if (is_friend_decl == 2)
3657 msg = "default template arguments may not be used in function template friend re-declaration";
3658 else if (is_friend_decl)
3659 msg = "default template arguments may not be used in function template friend declarations";
3660 else if (TREE_CODE (decl) == FUNCTION_DECL && (cxx_dialect == cxx98))
3661 msg = "default template arguments may not be used in function templates";
3662 else if (is_partial)
3663 msg = "default template arguments may not be used in partial specializations";
3665 msg = "default argument for template parameter for class enclosing %qD";
3667 if (current_class_type && TYPE_BEING_DEFINED (current_class_type))
3668 /* If we're inside a class definition, there's no need to
3669 examine the parameters to the class itself. On the one
3670 hand, they will be checked when the class is defined, and,
3671 on the other, default arguments are valid in things like:
3672 template <class T = double>
3673 struct S { template <class U> void f(U); };
3674 Here the default argument for `S' has no bearing on the
3675 declaration of `f'. */
3676 last_level_to_check = template_class_depth (current_class_type) + 1;
3678 /* Check everything. */
3679 last_level_to_check = 0;
3681 for (parm_level = parms;
3682 parm_level && TMPL_PARMS_DEPTH (parm_level) >= last_level_to_check;
3683 parm_level = TREE_CHAIN (parm_level))
3685 tree inner_parms = TREE_VALUE (parm_level);
3689 ntparms = TREE_VEC_LENGTH (inner_parms);
3690 for (i = 0; i < ntparms; ++i)
3692 if (TREE_VEC_ELT (inner_parms, i) == error_mark_node)
3695 if (TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)))
3700 if (is_friend_decl == 2)
3707 /* Clear out the default argument so that we are not
3709 TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)) = NULL_TREE;
3713 /* At this point, if we're still interested in issuing messages,
3714 they must apply to classes surrounding the object declared. */
3716 msg = "default argument for template parameter for class enclosing %qD";
3722 /* Worker for push_template_decl_real, called via
3723 for_each_template_parm. DATA is really an int, indicating the
3724 level of the parameters we are interested in. If T is a template
3725 parameter of that level, return nonzero. */
3728 template_parm_this_level_p (tree t, void* data)
3730 int this_level = *(int *)data;
3733 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
3734 level = TEMPLATE_PARM_LEVEL (t);
3736 level = TEMPLATE_TYPE_LEVEL (t);
3737 return level == this_level;
3740 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
3741 parameters given by current_template_args, or reuses a
3742 previously existing one, if appropriate. Returns the DECL, or an
3743 equivalent one, if it is replaced via a call to duplicate_decls.
3745 If IS_FRIEND is true, DECL is a friend declaration. */
3748 push_template_decl_real (tree decl, bool is_friend)
3756 int new_template_p = 0;
3757 /* True if the template is a member template, in the sense of
3759 bool member_template_p = false;
3761 if (decl == error_mark_node || !current_template_parms)
3762 return error_mark_node;
3764 /* See if this is a partial specialization. */
3765 is_partial = (DECL_IMPLICIT_TYPEDEF_P (decl)
3766 && TREE_CODE (TREE_TYPE (decl)) != ENUMERAL_TYPE
3767 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)));
3769 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_FRIEND_P (decl))
3773 /* For a friend, we want the context of the friend function, not
3774 the type of which it is a friend. */
3775 ctx = DECL_CONTEXT (decl);
3776 else if (CP_DECL_CONTEXT (decl)
3777 && TREE_CODE (CP_DECL_CONTEXT (decl)) != NAMESPACE_DECL)
3778 /* In the case of a virtual function, we want the class in which
3780 ctx = CP_DECL_CONTEXT (decl);
3782 /* Otherwise, if we're currently defining some class, the DECL
3783 is assumed to be a member of the class. */
3784 ctx = current_scope ();
3786 if (ctx && TREE_CODE (ctx) == NAMESPACE_DECL)
3789 if (!DECL_CONTEXT (decl))
3790 DECL_CONTEXT (decl) = FROB_CONTEXT (current_namespace);
3792 /* See if this is a primary template. */
3793 if (is_friend && ctx)
3794 /* A friend template that specifies a class context, i.e.
3795 template <typename T> friend void A<T>::f();
3799 primary = template_parm_scope_p ();
3803 if (DECL_CLASS_SCOPE_P (decl))
3804 member_template_p = true;
3805 if (TREE_CODE (decl) == TYPE_DECL
3806 && ANON_AGGRNAME_P (DECL_NAME (decl)))
3808 error ("template class without a name");
3809 return error_mark_node;
3811 else if (TREE_CODE (decl) == FUNCTION_DECL)
3813 if (DECL_DESTRUCTOR_P (decl))
3817 A destructor shall not be a member template. */
3818 error ("destructor %qD declared as member template", decl);
3819 return error_mark_node;
3821 if (NEW_DELETE_OPNAME_P (DECL_NAME (decl))
3822 && (!TYPE_ARG_TYPES (TREE_TYPE (decl))
3823 || TYPE_ARG_TYPES (TREE_TYPE (decl)) == void_list_node
3824 || !TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (decl)))
3825 || (TREE_CHAIN (TYPE_ARG_TYPES ((TREE_TYPE (decl))))
3826 == void_list_node)))
3828 /* [basic.stc.dynamic.allocation]
3830 An allocation function can be a function
3831 template. ... Template allocation functions shall
3832 have two or more parameters. */
3833 error ("invalid template declaration of %qD", decl);
3834 return error_mark_node;
3837 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
3838 && CLASS_TYPE_P (TREE_TYPE (decl)))
3842 error ("template declaration of %q#D", decl);
3843 return error_mark_node;
3847 /* Check to see that the rules regarding the use of default
3848 arguments are not being violated. */
3849 check_default_tmpl_args (decl, current_template_parms,
3850 primary, is_partial, /*is_friend_decl=*/0);
3852 /* Ensure that there are no parameter packs in the type of this
3853 declaration that have not been expanded. */
3854 if (TREE_CODE (decl) == FUNCTION_DECL)
3856 /* Check each of the arguments individually to see if there are
3857 any bare parameter packs. */
3858 tree type = TREE_TYPE (decl);
3859 tree arg = DECL_ARGUMENTS (decl);
3860 tree argtype = TYPE_ARG_TYPES (type);
3862 while (arg && argtype)
3864 if (!FUNCTION_PARAMETER_PACK_P (arg)
3865 && check_for_bare_parameter_packs (TREE_TYPE (arg)))
3867 /* This is a PARM_DECL that contains unexpanded parameter
3868 packs. We have already complained about this in the
3869 check_for_bare_parameter_packs call, so just replace
3870 these types with ERROR_MARK_NODE. */
3871 TREE_TYPE (arg) = error_mark_node;
3872 TREE_VALUE (argtype) = error_mark_node;
3875 arg = TREE_CHAIN (arg);
3876 argtype = TREE_CHAIN (argtype);
3879 /* Check for bare parameter packs in the return type and the
3880 exception specifiers. */
3881 if (check_for_bare_parameter_packs (TREE_TYPE (type)))
3882 /* Errors were already issued, set return type to int
3883 as the frontend doesn't expect error_mark_node as
3885 TREE_TYPE (type) = integer_type_node;
3886 if (check_for_bare_parameter_packs (TYPE_RAISES_EXCEPTIONS (type)))
3887 TYPE_RAISES_EXCEPTIONS (type) = NULL_TREE;
3889 else if (check_for_bare_parameter_packs (TREE_TYPE (decl)))
3891 TREE_TYPE (decl) = error_mark_node;
3892 return error_mark_node;
3896 return process_partial_specialization (decl);
3898 args = current_template_args ();
3901 || TREE_CODE (ctx) == FUNCTION_DECL
3902 || (CLASS_TYPE_P (ctx) && TYPE_BEING_DEFINED (ctx))
3903 || (is_friend && !DECL_TEMPLATE_INFO (decl)))
3905 if (DECL_LANG_SPECIFIC (decl)
3906 && DECL_TEMPLATE_INFO (decl)
3907 && DECL_TI_TEMPLATE (decl))
3908 tmpl = DECL_TI_TEMPLATE (decl);
3909 /* If DECL is a TYPE_DECL for a class-template, then there won't
3910 be DECL_LANG_SPECIFIC. The information equivalent to
3911 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
3912 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
3913 && TYPE_TEMPLATE_INFO (TREE_TYPE (decl))
3914 && TYPE_TI_TEMPLATE (TREE_TYPE (decl)))
3916 /* Since a template declaration already existed for this
3917 class-type, we must be redeclaring it here. Make sure
3918 that the redeclaration is valid. */
3919 redeclare_class_template (TREE_TYPE (decl),
3920 current_template_parms);
3921 /* We don't need to create a new TEMPLATE_DECL; just use the
3922 one we already had. */
3923 tmpl = TYPE_TI_TEMPLATE (TREE_TYPE (decl));
3927 tmpl = build_template_decl (decl, current_template_parms,
3931 if (DECL_LANG_SPECIFIC (decl)
3932 && DECL_TEMPLATE_SPECIALIZATION (decl))
3934 /* A specialization of a member template of a template
3936 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
3937 DECL_TEMPLATE_INFO (tmpl) = DECL_TEMPLATE_INFO (decl);
3938 DECL_TEMPLATE_INFO (decl) = NULL_TREE;
3944 tree a, t, current, parms;
3946 tree tinfo = get_template_info (decl);
3950 error ("template definition of non-template %q#D", decl);
3951 return error_mark_node;
3954 tmpl = TI_TEMPLATE (tinfo);
3956 if (DECL_FUNCTION_TEMPLATE_P (tmpl)
3957 && DECL_TEMPLATE_INFO (decl) && DECL_TI_ARGS (decl)
3958 && DECL_TEMPLATE_SPECIALIZATION (decl)
3959 && DECL_MEMBER_TEMPLATE_P (tmpl))
3963 /* The declaration is a specialization of a member
3964 template, declared outside the class. Therefore, the
3965 innermost template arguments will be NULL, so we
3966 replace them with the arguments determined by the
3967 earlier call to check_explicit_specialization. */
3968 args = DECL_TI_ARGS (decl);
3971 = build_template_decl (decl, current_template_parms,
3973 DECL_TEMPLATE_RESULT (new_tmpl) = decl;
3974 TREE_TYPE (new_tmpl) = TREE_TYPE (decl);
3975 DECL_TI_TEMPLATE (decl) = new_tmpl;
3976 SET_DECL_TEMPLATE_SPECIALIZATION (new_tmpl);
3977 DECL_TEMPLATE_INFO (new_tmpl)
3978 = tree_cons (tmpl, args, NULL_TREE);
3980 register_specialization (new_tmpl,
3981 most_general_template (tmpl),
3987 /* Make sure the template headers we got make sense. */
3989 parms = DECL_TEMPLATE_PARMS (tmpl);
3990 i = TMPL_PARMS_DEPTH (parms);
3991 if (TMPL_ARGS_DEPTH (args) != i)
3993 error ("expected %d levels of template parms for %q#D, got %d",
3994 i, decl, TMPL_ARGS_DEPTH (args));
3997 for (current = decl; i > 0; --i, parms = TREE_CHAIN (parms))
3999 a = TMPL_ARGS_LEVEL (args, i);
4000 t = INNERMOST_TEMPLATE_PARMS (parms);
4002 if (TREE_VEC_LENGTH (t) != TREE_VEC_LENGTH (a))
4004 if (current == decl)
4005 error ("got %d template parameters for %q#D",
4006 TREE_VEC_LENGTH (a), decl);
4008 error ("got %d template parameters for %q#T",
4009 TREE_VEC_LENGTH (a), current);
4010 error (" but %d required", TREE_VEC_LENGTH (t));
4011 return error_mark_node;
4014 if (current == decl)
4017 current = (TYPE_P (current)
4018 ? TYPE_CONTEXT (current)
4019 : DECL_CONTEXT (current));
4022 /* Check that the parms are used in the appropriate qualifying scopes
4023 in the declarator. */
4024 if (!comp_template_args
4026 TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (tmpl)))))
4029 template arguments to %qD do not match original template %qD",
4030 decl, DECL_TEMPLATE_RESULT (tmpl));
4031 if (!uses_template_parms (TI_ARGS (tinfo)))
4032 inform (input_location, "use template<> for an explicit specialization");
4033 /* Avoid crash in import_export_decl. */
4034 DECL_INTERFACE_KNOWN (decl) = 1;
4035 return error_mark_node;
4039 DECL_TEMPLATE_RESULT (tmpl) = decl;
4040 TREE_TYPE (tmpl) = TREE_TYPE (decl);
4042 /* Push template declarations for global functions and types. Note
4043 that we do not try to push a global template friend declared in a
4044 template class; such a thing may well depend on the template
4045 parameters of the class. */
4046 if (new_template_p && !ctx
4047 && !(is_friend && template_class_depth (current_class_type) > 0))
4049 tmpl = pushdecl_namespace_level (tmpl, is_friend);
4050 if (tmpl == error_mark_node)
4051 return error_mark_node;
4053 /* Hide template friend classes that haven't been declared yet. */
4054 if (is_friend && TREE_CODE (decl) == TYPE_DECL)
4056 DECL_ANTICIPATED (tmpl) = 1;
4057 DECL_FRIEND_P (tmpl) = 1;
4063 tree parms = DECL_TEMPLATE_PARMS (tmpl);
4066 DECL_PRIMARY_TEMPLATE (tmpl) = tmpl;
4067 if (DECL_CONV_FN_P (tmpl))
4069 int depth = TMPL_PARMS_DEPTH (parms);
4071 /* It is a conversion operator. See if the type converted to
4072 depends on innermost template operands. */
4074 if (uses_template_parms_level (TREE_TYPE (TREE_TYPE (tmpl)),
4076 DECL_TEMPLATE_CONV_FN_P (tmpl) = 1;
4079 /* Give template template parms a DECL_CONTEXT of the template
4080 for which they are a parameter. */
4081 parms = INNERMOST_TEMPLATE_PARMS (parms);
4082 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
4084 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
4085 if (TREE_CODE (parm) == TEMPLATE_DECL)
4086 DECL_CONTEXT (parm) = tmpl;
4090 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
4091 back to its most general template. If TMPL is a specialization,
4092 ARGS may only have the innermost set of arguments. Add the missing
4093 argument levels if necessary. */
4094 if (DECL_TEMPLATE_INFO (tmpl))
4095 args = add_outermost_template_args (DECL_TI_ARGS (tmpl), args);
4097 info = tree_cons (tmpl, args, NULL_TREE);
4099 if (DECL_IMPLICIT_TYPEDEF_P (decl))
4100 SET_TYPE_TEMPLATE_INFO (TREE_TYPE (tmpl), info);
4101 else if (DECL_LANG_SPECIFIC (decl))
4102 DECL_TEMPLATE_INFO (decl) = info;
4104 return DECL_TEMPLATE_RESULT (tmpl);
4108 push_template_decl (tree decl)
4110 return push_template_decl_real (decl, false);
4113 /* Called when a class template TYPE is redeclared with the indicated
4114 template PARMS, e.g.:
4116 template <class T> struct S;
4117 template <class T> struct S {}; */
4120 redeclare_class_template (tree type, tree parms)
4126 if (!TYPE_TEMPLATE_INFO (type))
4128 error ("%qT is not a template type", type);
4132 tmpl = TYPE_TI_TEMPLATE (type);
4133 if (!PRIMARY_TEMPLATE_P (tmpl))
4134 /* The type is nested in some template class. Nothing to worry
4135 about here; there are no new template parameters for the nested
4141 error ("template specifiers not specified in declaration of %qD",
4146 parms = INNERMOST_TEMPLATE_PARMS (parms);
4147 tmpl_parms = DECL_INNERMOST_TEMPLATE_PARMS (tmpl);
4149 if (TREE_VEC_LENGTH (parms) != TREE_VEC_LENGTH (tmpl_parms))
4151 error ("redeclared with %d template parameter(s)",
4152 TREE_VEC_LENGTH (parms));
4153 inform (input_location, "previous declaration %q+D used %d template parameter(s)",
4154 tmpl, TREE_VEC_LENGTH (tmpl_parms));
4158 for (i = 0; i < TREE_VEC_LENGTH (tmpl_parms); ++i)
4165 if (TREE_VEC_ELT (tmpl_parms, i) == error_mark_node
4166 || TREE_VEC_ELT (parms, i) == error_mark_node)
4169 tmpl_parm = TREE_VALUE (TREE_VEC_ELT (tmpl_parms, i));
4170 parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
4171 tmpl_default = TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i));
4172 parm_default = TREE_PURPOSE (TREE_VEC_ELT (parms, i));
4174 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
4176 if (tmpl_parm != error_mark_node
4177 && (TREE_CODE (tmpl_parm) != TREE_CODE (parm)
4178 || (TREE_CODE (tmpl_parm) != TYPE_DECL
4179 && !same_type_p (TREE_TYPE (tmpl_parm), TREE_TYPE (parm)))
4180 || (TREE_CODE (tmpl_parm) != PARM_DECL
4181 && (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (tmpl_parm))
4182 != TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm))))
4183 || (TREE_CODE (tmpl_parm) == PARM_DECL
4184 && (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (tmpl_parm))
4185 != TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))))))
4187 error ("template parameter %q+#D", tmpl_parm);
4188 error ("redeclared here as %q#D", parm);
4192 if (tmpl_default != NULL_TREE && parm_default != NULL_TREE)
4194 /* We have in [temp.param]:
4196 A template-parameter may not be given default arguments
4197 by two different declarations in the same scope. */
4198 error ("redefinition of default argument for %q#D", parm);
4199 inform (input_location, "%Joriginal definition appeared here", tmpl_parm);
4203 if (parm_default != NULL_TREE)
4204 /* Update the previous template parameters (which are the ones
4205 that will really count) with the new default value. */
4206 TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i)) = parm_default;
4207 else if (tmpl_default != NULL_TREE)
4208 /* Update the new parameters, too; they'll be used as the
4209 parameters for any members. */
4210 TREE_PURPOSE (TREE_VEC_ELT (parms, i)) = tmpl_default;
4216 /* Simplify EXPR if it is a non-dependent expression. Returns the
4217 (possibly simplified) expression. */
4220 fold_non_dependent_expr (tree expr)
4222 if (expr == NULL_TREE)
4225 /* If we're in a template, but EXPR isn't value dependent, simplify
4226 it. We're supposed to treat:
4228 template <typename T> void f(T[1 + 1]);
4229 template <typename T> void f(T[2]);
4231 as two declarations of the same function, for example. */
4232 if (processing_template_decl
4233 && !type_dependent_expression_p (expr)
4234 && !value_dependent_expression_p (expr))
4236 HOST_WIDE_INT saved_processing_template_decl;
4238 saved_processing_template_decl = processing_template_decl;
4239 processing_template_decl = 0;
4240 expr = tsubst_copy_and_build (expr,
4243 /*in_decl=*/NULL_TREE,
4244 /*function_p=*/false,
4245 /*integral_constant_expression_p=*/true);
4246 processing_template_decl = saved_processing_template_decl;
4251 /* EXPR is an expression which is used in a constant-expression context.
4252 For instance, it could be a VAR_DECL with a constant initializer.
4253 Extract the innermost constant expression.
4255 This is basically a more powerful version of
4256 integral_constant_value, which can be used also in templates where
4257 initializers can maintain a syntactic rather than semantic form
4258 (even if they are non-dependent, for access-checking purposes). */
4261 fold_decl_constant_value (tree expr)
4263 tree const_expr = expr;
4266 expr = fold_non_dependent_expr (const_expr);
4267 const_expr = integral_constant_value (expr);
4269 while (expr != const_expr);
4274 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
4275 must be a function or a pointer-to-function type, as specified
4276 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
4277 and check that the resulting function has external linkage. */
4280 convert_nontype_argument_function (tree type, tree expr)
4285 fn = instantiate_type (type, fns, tf_none);
4286 if (fn == error_mark_node)
4287 return error_mark_node;
4290 if (TREE_CODE (fn_no_ptr) == ADDR_EXPR)
4291 fn_no_ptr = TREE_OPERAND (fn_no_ptr, 0);
4292 if (TREE_CODE (fn_no_ptr) == BASELINK)
4293 fn_no_ptr = BASELINK_FUNCTIONS (fn_no_ptr);
4295 /* [temp.arg.nontype]/1
4297 A template-argument for a non-type, non-template template-parameter
4300 -- the address of an object or function with external linkage. */
4301 if (!DECL_EXTERNAL_LINKAGE_P (fn_no_ptr))
4303 error ("%qE is not a valid template argument for type %qT "
4304 "because function %qD has not external linkage",
4305 expr, type, fn_no_ptr);
4312 /* Attempt to convert the non-type template parameter EXPR to the
4313 indicated TYPE. If the conversion is successful, return the
4314 converted value. If the conversion is unsuccessful, return
4315 NULL_TREE if we issued an error message, or error_mark_node if we
4316 did not. We issue error messages for out-and-out bad template
4317 parameters, but not simply because the conversion failed, since we
4318 might be just trying to do argument deduction. Both TYPE and EXPR
4319 must be non-dependent.
4321 The conversion follows the special rules described in
4322 [temp.arg.nontype], and it is much more strict than an implicit
4325 This function is called twice for each template argument (see
4326 lookup_template_class for a more accurate description of this
4327 problem). This means that we need to handle expressions which
4328 are not valid in a C++ source, but can be created from the
4329 first call (for instance, casts to perform conversions). These
4330 hacks can go away after we fix the double coercion problem. */
4333 convert_nontype_argument (tree type, tree expr)
4337 /* Detect immediately string literals as invalid non-type argument.
4338 This special-case is not needed for correctness (we would easily
4339 catch this later), but only to provide better diagnostic for this
4340 common user mistake. As suggested by DR 100, we do not mention
4341 linkage issues in the diagnostic as this is not the point. */
4342 if (TREE_CODE (expr) == STRING_CST)
4344 error ("%qE is not a valid template argument for type %qT "
4345 "because string literals can never be used in this context",
4350 /* If we are in a template, EXPR may be non-dependent, but still
4351 have a syntactic, rather than semantic, form. For example, EXPR
4352 might be a SCOPE_REF, rather than the VAR_DECL to which the
4353 SCOPE_REF refers. Preserving the qualifying scope is necessary
4354 so that access checking can be performed when the template is
4355 instantiated -- but here we need the resolved form so that we can
4356 convert the argument. */
4357 expr = fold_non_dependent_expr (expr);
4358 if (error_operand_p (expr))
4359 return error_mark_node;
4360 expr_type = TREE_TYPE (expr);
4362 /* HACK: Due to double coercion, we can get a
4363 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
4364 which is the tree that we built on the first call (see
4365 below when coercing to reference to object or to reference to
4366 function). We just strip everything and get to the arg.
4367 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
4369 if (TREE_CODE (expr) == NOP_EXPR)
4371 if (TYPE_REF_OBJ_P (type) || TYPE_REFFN_P (type))
4373 /* ??? Maybe we could use convert_from_reference here, but we
4374 would need to relax its constraints because the NOP_EXPR
4375 could actually change the type to something more cv-qualified,
4376 and this is not folded by convert_from_reference. */
4377 tree addr = TREE_OPERAND (expr, 0);
4378 gcc_assert (TREE_CODE (expr_type) == REFERENCE_TYPE);
4379 gcc_assert (TREE_CODE (addr) == ADDR_EXPR);
4380 gcc_assert (TREE_CODE (TREE_TYPE (addr)) == POINTER_TYPE);
4381 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4382 (TREE_TYPE (expr_type),
4383 TREE_TYPE (TREE_TYPE (addr))));
4385 expr = TREE_OPERAND (addr, 0);
4386 expr_type = TREE_TYPE (expr);
4389 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
4390 parameter is a pointer to object, through decay and
4391 qualification conversion. Let's strip everything. */
4392 else if (TYPE_PTROBV_P (type))
4395 gcc_assert (TREE_CODE (expr) == ADDR_EXPR);
4396 gcc_assert (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE);
4397 /* Skip the ADDR_EXPR only if it is part of the decay for
4398 an array. Otherwise, it is part of the original argument
4399 in the source code. */
4400 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == ARRAY_TYPE)
4401 expr = TREE_OPERAND (expr, 0);
4402 expr_type = TREE_TYPE (expr);
4406 /* [temp.arg.nontype]/5, bullet 1
4408 For a non-type template-parameter of integral or enumeration type,
4409 integral promotions (_conv.prom_) and integral conversions
4410 (_conv.integral_) are applied. */
4411 if (INTEGRAL_TYPE_P (type))
4413 if (!INTEGRAL_TYPE_P (expr_type))
4414 return error_mark_node;
4416 expr = fold_decl_constant_value (expr);
4417 /* Notice that there are constant expressions like '4 % 0' which
4418 do not fold into integer constants. */
4419 if (TREE_CODE (expr) != INTEGER_CST)
4421 error ("%qE is not a valid template argument for type %qT "
4422 "because it is a non-constant expression", expr, type);
4426 /* At this point, an implicit conversion does what we want,
4427 because we already know that the expression is of integral
4429 expr = ocp_convert (type, expr, CONV_IMPLICIT, LOOKUP_PROTECT);
4430 if (expr == error_mark_node)
4431 return error_mark_node;
4433 /* Conversion was allowed: fold it to a bare integer constant. */
4436 /* [temp.arg.nontype]/5, bullet 2
4438 For a non-type template-parameter of type pointer to object,
4439 qualification conversions (_conv.qual_) and the array-to-pointer
4440 conversion (_conv.array_) are applied. */
4441 else if (TYPE_PTROBV_P (type))
4443 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
4445 A template-argument for a non-type, non-template template-parameter
4446 shall be one of: [...]
4448 -- the name of a non-type template-parameter;
4449 -- the address of an object or function with external linkage, [...]
4450 expressed as "& id-expression" where the & is optional if the name
4451 refers to a function or array, or if the corresponding
4452 template-parameter is a reference.
4454 Here, we do not care about functions, as they are invalid anyway
4455 for a parameter of type pointer-to-object. */
4457 if (DECL_P (expr) && DECL_TEMPLATE_PARM_P (expr))
4458 /* Non-type template parameters are OK. */
4460 else if (TREE_CODE (expr) != ADDR_EXPR
4461 && TREE_CODE (expr_type) != ARRAY_TYPE)
4463 if (TREE_CODE (expr) == VAR_DECL)
4465 error ("%qD is not a valid template argument "
4466 "because %qD is a variable, not the address of "
4471 /* Other values, like integer constants, might be valid
4472 non-type arguments of some other type. */
4473 return error_mark_node;
4479 decl = ((TREE_CODE (expr) == ADDR_EXPR)
4480 ? TREE_OPERAND (expr, 0) : expr);
4481 if (TREE_CODE (decl) != VAR_DECL)
4483 error ("%qE is not a valid template argument of type %qT "
4484 "because %qE is not a variable",
4488 else if (!DECL_EXTERNAL_LINKAGE_P (decl))
4490 error ("%qE is not a valid template argument of type %qT "
4491 "because %qD does not have external linkage",
4497 expr = decay_conversion (expr);
4498 if (expr == error_mark_node)
4499 return error_mark_node;
4501 expr = perform_qualification_conversions (type, expr);
4502 if (expr == error_mark_node)
4503 return error_mark_node;
4505 /* [temp.arg.nontype]/5, bullet 3
4507 For a non-type template-parameter of type reference to object, no
4508 conversions apply. The type referred to by the reference may be more
4509 cv-qualified than the (otherwise identical) type of the
4510 template-argument. The template-parameter is bound directly to the
4511 template-argument, which must be an lvalue. */
4512 else if (TYPE_REF_OBJ_P (type))
4514 if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type),
4516 return error_mark_node;
4518 if (!at_least_as_qualified_p (TREE_TYPE (type), expr_type))
4520 error ("%qE is not a valid template argument for type %qT "
4521 "because of conflicts in cv-qualification", expr, type);
4525 if (!real_lvalue_p (expr))
4527 error ("%qE is not a valid template argument for type %qT "
4528 "because it is not an lvalue", expr, type);
4532 /* [temp.arg.nontype]/1
4534 A template-argument for a non-type, non-template template-parameter
4535 shall be one of: [...]
4537 -- the address of an object or function with external linkage. */
4538 if (!DECL_EXTERNAL_LINKAGE_P (expr))
4540 error ("%qE is not a valid template argument for type %qT "
4541 "because object %qD has not external linkage",
4546 expr = build_nop (type, build_address (expr));
4548 /* [temp.arg.nontype]/5, bullet 4
4550 For a non-type template-parameter of type pointer to function, only
4551 the function-to-pointer conversion (_conv.func_) is applied. If the
4552 template-argument represents a set of overloaded functions (or a
4553 pointer to such), the matching function is selected from the set
4555 else if (TYPE_PTRFN_P (type))
4557 /* If the argument is a template-id, we might not have enough
4558 context information to decay the pointer. */
4559 if (!type_unknown_p (expr_type))
4561 expr = decay_conversion (expr);
4562 if (expr == error_mark_node)
4563 return error_mark_node;
4566 expr = convert_nontype_argument_function (type, expr);
4567 if (!expr || expr == error_mark_node)
4570 /* [temp.arg.nontype]/5, bullet 5
4572 For a non-type template-parameter of type reference to function, no
4573 conversions apply. If the template-argument represents a set of
4574 overloaded functions, the matching function is selected from the set
4576 else if (TYPE_REFFN_P (type))
4578 if (TREE_CODE (expr) == ADDR_EXPR)
4580 error ("%qE is not a valid template argument for type %qT "
4581 "because it is a pointer", expr, type);
4582 inform (input_location, "try using %qE instead", TREE_OPERAND (expr, 0));
4586 expr = convert_nontype_argument_function (TREE_TYPE (type), expr);
4587 if (!expr || expr == error_mark_node)
4590 expr = build_nop (type, build_address (expr));
4592 /* [temp.arg.nontype]/5, bullet 6
4594 For a non-type template-parameter of type pointer to member function,
4595 no conversions apply. If the template-argument represents a set of
4596 overloaded member functions, the matching member function is selected
4597 from the set (_over.over_). */
4598 else if (TYPE_PTRMEMFUNC_P (type))
4600 expr = instantiate_type (type, expr, tf_none);
4601 if (expr == error_mark_node)
4602 return error_mark_node;
4604 /* There is no way to disable standard conversions in
4605 resolve_address_of_overloaded_function (called by
4606 instantiate_type). It is possible that the call succeeded by
4607 converting &B::I to &D::I (where B is a base of D), so we need
4608 to reject this conversion here.
4610 Actually, even if there was a way to disable standard conversions,
4611 it would still be better to reject them here so that we can
4612 provide a superior diagnostic. */
4613 if (!same_type_p (TREE_TYPE (expr), type))
4615 /* Make sure we are just one standard conversion off. */
4616 gcc_assert (can_convert (type, TREE_TYPE (expr)));
4617 error ("%qE is not a valid template argument for type %qT "
4618 "because it is of type %qT", expr, type,
4620 inform (input_location, "standard conversions are not allowed in this context");
4624 /* [temp.arg.nontype]/5, bullet 7
4626 For a non-type template-parameter of type pointer to data member,
4627 qualification conversions (_conv.qual_) are applied. */
4628 else if (TYPE_PTRMEM_P (type))
4630 expr = perform_qualification_conversions (type, expr);
4631 if (expr == error_mark_node)
4634 /* A template non-type parameter must be one of the above. */
4638 /* Sanity check: did we actually convert the argument to the
4640 gcc_assert (same_type_p (type, TREE_TYPE (expr)));
4644 /* Subroutine of coerce_template_template_parms, which returns 1 if
4645 PARM_PARM and ARG_PARM match using the rule for the template
4646 parameters of template template parameters. Both PARM and ARG are
4647 template parameters; the rest of the arguments are the same as for
4648 coerce_template_template_parms.
4651 coerce_template_template_parm (tree parm,
4653 tsubst_flags_t complain,
4657 if (arg == NULL_TREE || arg == error_mark_node
4658 || parm == NULL_TREE || parm == error_mark_node)
4661 if (TREE_CODE (arg) != TREE_CODE (parm))
4664 switch (TREE_CODE (parm))
4667 /* We encounter instantiations of templates like
4668 template <template <template <class> class> class TT>
4671 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
4672 tree argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
4674 if (!coerce_template_template_parms
4675 (parmparm, argparm, complain, in_decl, outer_args))
4681 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (arg))
4682 && !TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
4683 /* Argument is a parameter pack but parameter is not. */
4688 /* The tsubst call is used to handle cases such as
4690 template <int> class C {};
4691 template <class T, template <T> class TT> class D {};
4694 i.e. the parameter list of TT depends on earlier parameters. */
4695 if (!uses_template_parms (TREE_TYPE (arg))
4697 (tsubst (TREE_TYPE (parm), outer_args, complain, in_decl),
4701 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (arg))
4702 && !TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
4703 /* Argument is a parameter pack but parameter is not. */
4716 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
4717 template template parameters. Both PARM_PARMS and ARG_PARMS are
4718 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
4721 Consider the example:
4722 template <class T> class A;
4723 template<template <class U> class TT> class B;
4725 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
4726 the parameters to A, and OUTER_ARGS contains A. */
4729 coerce_template_template_parms (tree parm_parms,
4731 tsubst_flags_t complain,
4735 int nparms, nargs, i;
4739 gcc_assert (TREE_CODE (parm_parms) == TREE_VEC);
4740 gcc_assert (TREE_CODE (arg_parms) == TREE_VEC);
4742 nparms = TREE_VEC_LENGTH (parm_parms);
4743 nargs = TREE_VEC_LENGTH (arg_parms);
4745 /* Determine whether we have a parameter pack at the end of the
4746 template template parameter's template parameter list. */
4747 if (TREE_VEC_ELT (parm_parms, nparms - 1) != error_mark_node)
4749 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, nparms - 1));
4751 switch (TREE_CODE (parm))
4755 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
4760 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
4770 && !(variadic_p && nargs >= nparms - 1))
4773 /* Check all of the template parameters except the parameter pack at
4774 the end (if any). */
4775 for (i = 0; i < nparms - variadic_p; ++i)
4777 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node
4778 || TREE_VEC_ELT (arg_parms, i) == error_mark_node)
4781 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
4782 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
4784 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
4792 /* Check each of the template parameters in the template
4793 argument against the template parameter pack at the end of
4794 the template template parameter. */
4795 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node)
4798 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
4800 for (; i < nargs; ++i)
4802 if (TREE_VEC_ELT (arg_parms, i) == error_mark_node)
4805 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
4807 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
4816 /* Verifies that the deduced template arguments (in TARGS) for the
4817 template template parameters (in TPARMS) represent valid bindings,
4818 by comparing the template parameter list of each template argument
4819 to the template parameter list of its corresponding template
4820 template parameter, in accordance with DR150. This
4821 routine can only be called after all template arguments have been
4822 deduced. It will return TRUE if all of the template template
4823 parameter bindings are okay, FALSE otherwise. */
4825 template_template_parm_bindings_ok_p (tree tparms, tree targs)
4827 int i, ntparms = TREE_VEC_LENGTH (tparms);
4830 /* We're dealing with template parms in this process. */
4831 ++processing_template_decl;
4833 targs = INNERMOST_TEMPLATE_ARGS (targs);
4835 for (i = 0; i < ntparms; ++i)
4837 tree tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
4838 tree targ = TREE_VEC_ELT (targs, i);
4840 if (TREE_CODE (tparm) == TEMPLATE_DECL && targ)
4842 tree packed_args = NULL_TREE;
4845 if (ARGUMENT_PACK_P (targ))
4847 /* Look inside the argument pack. */
4848 packed_args = ARGUMENT_PACK_ARGS (targ);
4849 len = TREE_VEC_LENGTH (packed_args);
4852 for (idx = 0; idx < len; ++idx)
4854 tree targ_parms = NULL_TREE;
4857 /* Extract the next argument from the argument
4859 targ = TREE_VEC_ELT (packed_args, idx);
4861 if (PACK_EXPANSION_P (targ))
4862 /* Look at the pattern of the pack expansion. */
4863 targ = PACK_EXPANSION_PATTERN (targ);
4865 /* Extract the template parameters from the template
4867 if (TREE_CODE (targ) == TEMPLATE_DECL)
4868 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (targ);
4869 else if (TREE_CODE (targ) == TEMPLATE_TEMPLATE_PARM)
4870 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (TYPE_NAME (targ));
4872 /* Verify that we can coerce the template template
4873 parameters from the template argument to the template
4874 parameter. This requires an exact match. */
4876 && !coerce_template_template_parms
4877 (DECL_INNERMOST_TEMPLATE_PARMS (tparm),
4892 --processing_template_decl;
4896 /* Convert the indicated template ARG as necessary to match the
4897 indicated template PARM. Returns the converted ARG, or
4898 error_mark_node if the conversion was unsuccessful. Error and
4899 warning messages are issued under control of COMPLAIN. This
4900 conversion is for the Ith parameter in the parameter list. ARGS is
4901 the full set of template arguments deduced so far. */
4904 convert_template_argument (tree parm,
4907 tsubst_flags_t complain,
4913 int is_type, requires_type, is_tmpl_type, requires_tmpl_type;
4915 if (TREE_CODE (arg) == TREE_LIST
4916 && TREE_CODE (TREE_VALUE (arg)) == OFFSET_REF)
4918 /* The template argument was the name of some
4919 member function. That's usually
4920 invalid, but static members are OK. In any
4921 case, grab the underlying fields/functions
4922 and issue an error later if required. */
4923 orig_arg = TREE_VALUE (arg);
4924 TREE_TYPE (arg) = unknown_type_node;
4929 requires_tmpl_type = TREE_CODE (parm) == TEMPLATE_DECL;
4930 requires_type = (TREE_CODE (parm) == TYPE_DECL
4931 || requires_tmpl_type);
4933 /* When determining whether an argument pack expansion is a template,
4934 look at the pattern. */
4935 if (TREE_CODE (arg) == TYPE_PACK_EXPANSION)
4936 arg = PACK_EXPANSION_PATTERN (arg);
4939 ((TREE_CODE (arg) == TEMPLATE_DECL
4940 && TREE_CODE (DECL_TEMPLATE_RESULT (arg)) == TYPE_DECL)
4941 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
4942 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE);
4945 && (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
4946 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE))
4947 arg = TYPE_STUB_DECL (arg);
4949 is_type = TYPE_P (arg) || is_tmpl_type;
4951 if (requires_type && ! is_type && TREE_CODE (arg) == SCOPE_REF
4952 && TREE_CODE (TREE_OPERAND (arg, 0)) == TEMPLATE_TYPE_PARM)
4954 permerror (input_location, "to refer to a type member of a template parameter, "
4955 "use %<typename %E%>", orig_arg);
4957 orig_arg = make_typename_type (TREE_OPERAND (arg, 0),
4958 TREE_OPERAND (arg, 1),
4960 complain & tf_error);
4964 if (is_type != requires_type)
4968 if (complain & tf_error)
4970 error ("type/value mismatch at argument %d in template "
4971 "parameter list for %qD",
4974 error (" expected a constant of type %qT, got %qT",
4976 (DECL_P (arg) ? DECL_NAME (arg) : orig_arg));
4977 else if (requires_tmpl_type)
4978 error (" expected a class template, got %qE", orig_arg);
4980 error (" expected a type, got %qE", orig_arg);
4983 return error_mark_node;
4985 if (is_tmpl_type ^ requires_tmpl_type)
4987 if (in_decl && (complain & tf_error))
4989 error ("type/value mismatch at argument %d in template "
4990 "parameter list for %qD",
4993 error (" expected a type, got %qT", DECL_NAME (arg));
4995 error (" expected a class template, got %qT", orig_arg);
4997 return error_mark_node;
5002 if (requires_tmpl_type)
5004 if (TREE_CODE (TREE_TYPE (arg)) == UNBOUND_CLASS_TEMPLATE)
5005 /* The number of argument required is not known yet.
5006 Just accept it for now. */
5007 val = TREE_TYPE (arg);
5010 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
5013 argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
5015 if (coerce_template_template_parms (parmparm, argparm,
5021 /* TEMPLATE_TEMPLATE_PARM node is preferred over
5023 if (val != error_mark_node)
5025 if (DECL_TEMPLATE_TEMPLATE_PARM_P (val))
5026 val = TREE_TYPE (val);
5027 else if (TREE_CODE (val) == TYPE_PACK_EXPANSION
5028 && DECL_TEMPLATE_TEMPLATE_PARM_P (arg))
5030 val = TREE_TYPE (arg);
5031 val = make_pack_expansion (val);
5037 if (in_decl && (complain & tf_error))
5039 error ("type/value mismatch at argument %d in "
5040 "template parameter list for %qD",
5042 error (" expected a template of type %qD, got %qD",
5046 val = error_mark_node;
5052 /* We only form one instance of each template specialization.
5053 Therefore, if we use a non-canonical variant (i.e., a
5054 typedef), any future messages referring to the type will use
5055 the typedef, which is confusing if those future uses do not
5056 themselves also use the typedef. */
5058 val = canonical_type_variant (val);
5062 tree t = tsubst (TREE_TYPE (parm), args, complain, in_decl);
5064 if (invalid_nontype_parm_type_p (t, complain))
5065 return error_mark_node;
5067 if (template_parameter_pack_p (parm) && ARGUMENT_PACK_P (orig_arg))
5069 if (same_type_p (t, TREE_TYPE (orig_arg)))
5073 /* Not sure if this is reachable, but it doesn't hurt
5075 error ("type mismatch in nontype parameter pack");
5076 val = error_mark_node;
5079 else if (!uses_template_parms (orig_arg) && !uses_template_parms (t))
5080 /* We used to call digest_init here. However, digest_init
5081 will report errors, which we don't want when complain
5082 is zero. More importantly, digest_init will try too
5083 hard to convert things: for example, `0' should not be
5084 converted to pointer type at this point according to
5085 the standard. Accepting this is not merely an
5086 extension, since deciding whether or not these
5087 conversions can occur is part of determining which
5088 function template to call, or whether a given explicit
5089 argument specification is valid. */
5090 val = convert_nontype_argument (t, orig_arg);
5094 if (val == NULL_TREE)
5095 val = error_mark_node;
5096 else if (val == error_mark_node && (complain & tf_error))
5097 error ("could not convert template argument %qE to %qT", orig_arg, t);
5103 /* Coerces the remaining template arguments in INNER_ARGS (from
5104 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
5105 Returns the coerced argument pack. PARM_IDX is the position of this
5106 parameter in the template parameter list. ARGS is the original
5107 template argument list. */
5109 coerce_template_parameter_pack (tree parms,
5117 tsubst_flags_t complain)
5119 tree parm = TREE_VEC_ELT (parms, parm_idx);
5120 int nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
5123 tree packed_types = NULL_TREE;
5125 if (arg_idx > nargs)
5128 packed_args = make_tree_vec (nargs - arg_idx);
5130 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL
5131 && uses_parameter_packs (TREE_TYPE (TREE_VALUE (parm))))
5133 /* When the template parameter is a non-type template
5134 parameter pack whose type uses parameter packs, we need
5135 to look at each of the template arguments
5136 separately. Build a vector of the types for these
5137 non-type template parameters in PACKED_TYPES. */
5139 = make_pack_expansion (TREE_TYPE (TREE_VALUE (parm)));
5140 packed_types = tsubst_pack_expansion (expansion, args,
5143 if (packed_types == error_mark_node)
5144 return error_mark_node;
5146 /* Check that we have the right number of arguments. */
5148 && !PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx))
5149 && nargs - arg_idx != TREE_VEC_LENGTH (packed_types))
5152 = TREE_VEC_LENGTH (parms) - 1 + TREE_VEC_LENGTH (packed_types);
5153 error ("wrong number of template arguments (%d, should be %d)",
5154 nargs, needed_parms);
5155 return error_mark_node;
5158 /* If we aren't able to check the actual arguments now
5159 (because they haven't been expanded yet), we can at least
5160 verify that all of the types used for the non-type
5161 template parameter pack are, in fact, valid for non-type
5162 template parameters. */
5164 && PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx)))
5166 int j, len = TREE_VEC_LENGTH (packed_types);
5167 for (j = 0; j < len; ++j)
5169 tree t = TREE_VEC_ELT (packed_types, j);
5170 if (invalid_nontype_parm_type_p (t, complain))
5171 return error_mark_node;
5176 /* Convert the remaining arguments, which will be a part of the
5177 parameter pack "parm". */
5178 for (; arg_idx < nargs; ++arg_idx)
5180 tree arg = TREE_VEC_ELT (inner_args, arg_idx);
5181 tree actual_parm = TREE_VALUE (parm);
5183 if (packed_types && !PACK_EXPANSION_P (arg))
5185 /* When we have a vector of types (corresponding to the
5186 non-type template parameter pack that uses parameter
5187 packs in its type, as mention above), and the
5188 argument is not an expansion (which expands to a
5189 currently unknown number of arguments), clone the
5190 parm and give it the next type in PACKED_TYPES. */
5191 actual_parm = copy_node (actual_parm);
5192 TREE_TYPE (actual_parm) =
5193 TREE_VEC_ELT (packed_types, arg_idx - parm_idx);
5196 if (arg != error_mark_node)
5197 arg = convert_template_argument (actual_parm,
5198 arg, new_args, complain, parm_idx,
5200 if (arg == error_mark_node)
5202 TREE_VEC_ELT (packed_args, arg_idx - parm_idx) = arg;
5205 if (TREE_CODE (TREE_VALUE (parm)) == TYPE_DECL
5206 || TREE_CODE (TREE_VALUE (parm)) == TEMPLATE_DECL)
5207 argument_pack = make_node (TYPE_ARGUMENT_PACK);
5210 argument_pack = make_node (NONTYPE_ARGUMENT_PACK);
5211 TREE_TYPE (argument_pack)
5212 = tsubst (TREE_TYPE (TREE_VALUE (parm)), new_args, complain, in_decl);
5213 TREE_CONSTANT (argument_pack) = 1;
5216 SET_ARGUMENT_PACK_ARGS (argument_pack, packed_args);
5217 return argument_pack;
5220 /* Convert all template arguments to their appropriate types, and
5221 return a vector containing the innermost resulting template
5222 arguments. If any error occurs, return error_mark_node. Error and
5223 warning messages are issued under control of COMPLAIN.
5225 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
5226 for arguments not specified in ARGS. Otherwise, if
5227 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
5228 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
5229 USE_DEFAULT_ARGS is false, then all arguments must be specified in
5233 coerce_template_parms (tree parms,
5236 tsubst_flags_t complain,
5237 bool require_all_args,
5238 bool use_default_args)
5240 int nparms, nargs, parm_idx, arg_idx, lost = 0;
5243 tree new_inner_args;
5244 bool saved_skip_evaluation;
5246 /* When used as a boolean value, indicates whether this is a
5247 variadic template parameter list. Since it's an int, we can also
5248 subtract it from nparms to get the number of non-variadic
5252 nparms = TREE_VEC_LENGTH (parms);
5254 /* Determine if there are any parameter packs. */
5255 for (parm_idx = 0; parm_idx < nparms; ++parm_idx)
5257 tree tparm = TREE_VALUE (TREE_VEC_ELT (parms, parm_idx));
5258 if (template_parameter_pack_p (tparm))
5262 inner_args = INNERMOST_TEMPLATE_ARGS (args);
5263 /* If there are 0 or 1 parameter packs, we need to expand any argument
5264 packs so that we can deduce a parameter pack from some non-packed args
5265 followed by an argument pack, as in variadic85.C. If there are more
5266 than that, we need to leave argument packs intact so the arguments are
5267 assigned to the right parameter packs. This should only happen when
5268 dealing with a nested class inside a partial specialization of a class
5269 template, as in variadic92.C. */
5270 if (variadic_p <= 1)
5271 inner_args = expand_template_argument_pack (inner_args);
5273 nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
5274 if ((nargs > nparms && !variadic_p)
5275 || (nargs < nparms - variadic_p
5277 && (!use_default_args
5278 || (TREE_VEC_ELT (parms, nargs) != error_mark_node
5279 && !TREE_PURPOSE (TREE_VEC_ELT (parms, nargs))))))
5281 if (complain & tf_error)
5283 const char *or_more = "";
5286 or_more = " or more";
5290 error ("wrong number of template arguments (%d, should be %d%s)",
5291 nargs, nparms, or_more);
5294 error ("provided for %q+D", in_decl);
5297 return error_mark_node;
5300 /* We need to evaluate the template arguments, even though this
5301 template-id may be nested within a "sizeof". */
5302 saved_skip_evaluation = skip_evaluation;
5303 skip_evaluation = false;
5304 new_inner_args = make_tree_vec (nparms);
5305 new_args = add_outermost_template_args (args, new_inner_args);
5306 for (parm_idx = 0, arg_idx = 0; parm_idx < nparms; parm_idx++, arg_idx++)
5311 /* Get the Ith template parameter. */
5312 parm = TREE_VEC_ELT (parms, parm_idx);
5314 if (parm == error_mark_node)
5316 TREE_VEC_ELT (new_inner_args, arg_idx) = error_mark_node;
5320 /* Calculate the next argument. */
5321 if (arg_idx < nargs)
5322 arg = TREE_VEC_ELT (inner_args, arg_idx);
5326 if (template_parameter_pack_p (TREE_VALUE (parm))
5327 && !(arg && ARGUMENT_PACK_P (arg)))
5329 /* All remaining arguments will be placed in the
5330 template parameter pack PARM. */
5331 arg = coerce_template_parameter_pack (parms, parm_idx, args,
5332 inner_args, arg_idx,
5336 /* Store this argument. */
5337 if (arg == error_mark_node)
5339 TREE_VEC_ELT (new_inner_args, parm_idx) = arg;
5341 /* We are done with all of the arguments. */
5348 if (PACK_EXPANSION_P (arg))
5350 if (complain & tf_error)
5352 /* FIXME this restriction was removed by N2555; see
5354 /* If ARG is a pack expansion, but PARM is not a
5355 template parameter pack (if it were, we would have
5356 handled it above), we're trying to expand into a
5357 fixed-length argument list. */
5358 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
5359 sorry ("cannot expand %<%E%> into a fixed-length "
5360 "argument list", arg);
5362 sorry ("cannot expand %<%T%> into a fixed-length "
5363 "argument list", arg);
5365 return error_mark_node;
5368 else if (require_all_args)
5369 /* There must be a default arg in this case. */
5370 arg = tsubst_template_arg (TREE_PURPOSE (parm), new_args,
5375 if (arg == error_mark_node)
5377 if (complain & tf_error)
5378 error ("template argument %d is invalid", arg_idx + 1);
5381 /* This only occurs if there was an error in the template
5382 parameter list itself (which we would already have
5383 reported) that we are trying to recover from, e.g., a class
5384 template with a parameter list such as
5385 template<typename..., typename>. */
5386 return error_mark_node;
5388 arg = convert_template_argument (TREE_VALUE (parm),
5389 arg, new_args, complain,
5392 if (arg == error_mark_node)
5394 TREE_VEC_ELT (new_inner_args, arg_idx) = arg;
5396 skip_evaluation = saved_skip_evaluation;
5399 return error_mark_node;
5401 return new_inner_args;
5404 /* Returns 1 if template args OT and NT are equivalent. */
5407 template_args_equal (tree ot, tree nt)
5412 if (TREE_CODE (nt) == TREE_VEC)
5413 /* For member templates */
5414 return TREE_CODE (ot) == TREE_VEC && comp_template_args (ot, nt);
5415 else if (PACK_EXPANSION_P (ot))
5416 return PACK_EXPANSION_P (nt)
5417 && template_args_equal (PACK_EXPANSION_PATTERN (ot),
5418 PACK_EXPANSION_PATTERN (nt));
5419 else if (ARGUMENT_PACK_P (ot))
5424 if (!ARGUMENT_PACK_P (nt))
5427 opack = ARGUMENT_PACK_ARGS (ot);
5428 npack = ARGUMENT_PACK_ARGS (nt);
5429 len = TREE_VEC_LENGTH (opack);
5430 if (TREE_VEC_LENGTH (npack) != len)
5432 for (i = 0; i < len; ++i)
5433 if (!template_args_equal (TREE_VEC_ELT (opack, i),
5434 TREE_VEC_ELT (npack, i)))
5438 else if (TYPE_P (nt))
5439 return TYPE_P (ot) && same_type_p (ot, nt);
5440 else if (TREE_CODE (ot) == TREE_VEC || TYPE_P (ot))
5443 return cp_tree_equal (ot, nt);
5446 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
5447 of template arguments. Returns 0 otherwise. */
5450 comp_template_args (tree oldargs, tree newargs)
5454 if (TREE_VEC_LENGTH (oldargs) != TREE_VEC_LENGTH (newargs))
5457 for (i = 0; i < TREE_VEC_LENGTH (oldargs); ++i)
5459 tree nt = TREE_VEC_ELT (newargs, i);
5460 tree ot = TREE_VEC_ELT (oldargs, i);
5462 if (! template_args_equal (ot, nt))
5469 add_pending_template (tree d)
5471 tree ti = (TYPE_P (d)
5472 ? CLASSTYPE_TEMPLATE_INFO (d)
5473 : DECL_TEMPLATE_INFO (d));
5474 struct pending_template *pt;
5477 if (TI_PENDING_TEMPLATE_FLAG (ti))
5480 /* We are called both from instantiate_decl, where we've already had a
5481 tinst_level pushed, and instantiate_template, where we haven't.
5483 level = !current_tinst_level || current_tinst_level->decl != d;
5486 push_tinst_level (d);
5488 pt = GGC_NEW (struct pending_template);
5490 pt->tinst = current_tinst_level;
5491 if (last_pending_template)
5492 last_pending_template->next = pt;
5494 pending_templates = pt;
5496 last_pending_template = pt;
5498 TI_PENDING_TEMPLATE_FLAG (ti) = 1;
5505 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
5506 ARGLIST. Valid choices for FNS are given in the cp-tree.def
5507 documentation for TEMPLATE_ID_EXPR. */
5510 lookup_template_function (tree fns, tree arglist)
5514 if (fns == error_mark_node || arglist == error_mark_node)
5515 return error_mark_node;
5517 gcc_assert (!arglist || TREE_CODE (arglist) == TREE_VEC);
5518 gcc_assert (fns && (is_overloaded_fn (fns)
5519 || TREE_CODE (fns) == IDENTIFIER_NODE));
5521 if (BASELINK_P (fns))
5523 BASELINK_FUNCTIONS (fns) = build2 (TEMPLATE_ID_EXPR,
5525 BASELINK_FUNCTIONS (fns),
5530 type = TREE_TYPE (fns);
5531 if (TREE_CODE (fns) == OVERLOAD || !type)
5532 type = unknown_type_node;
5534 return build2 (TEMPLATE_ID_EXPR, type, fns, arglist);
5537 /* Within the scope of a template class S<T>, the name S gets bound
5538 (in build_self_reference) to a TYPE_DECL for the class, not a
5539 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
5540 or one of its enclosing classes, and that type is a template,
5541 return the associated TEMPLATE_DECL. Otherwise, the original
5542 DECL is returned. */
5545 maybe_get_template_decl_from_type_decl (tree decl)
5547 return (decl != NULL_TREE
5548 && TREE_CODE (decl) == TYPE_DECL
5549 && DECL_ARTIFICIAL (decl)
5550 && CLASS_TYPE_P (TREE_TYPE (decl))
5551 && CLASSTYPE_TEMPLATE_INFO (TREE_TYPE (decl)))
5552 ? CLASSTYPE_TI_TEMPLATE (TREE_TYPE (decl)) : decl;
5555 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
5556 parameters, find the desired type.
5558 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
5560 IN_DECL, if non-NULL, is the template declaration we are trying to
5563 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
5564 the class we are looking up.
5566 Issue error and warning messages under control of COMPLAIN.
5568 If the template class is really a local class in a template
5569 function, then the FUNCTION_CONTEXT is the function in which it is
5572 ??? Note that this function is currently called *twice* for each
5573 template-id: the first time from the parser, while creating the
5574 incomplete type (finish_template_type), and the second type during the
5575 real instantiation (instantiate_template_class). This is surely something
5576 that we want to avoid. It also causes some problems with argument
5577 coercion (see convert_nontype_argument for more information on this). */
5580 lookup_template_class (tree d1,
5585 tsubst_flags_t complain)
5587 tree templ = NULL_TREE, parmlist;
5590 timevar_push (TV_NAME_LOOKUP);
5592 if (TREE_CODE (d1) == IDENTIFIER_NODE)
5594 tree value = innermost_non_namespace_value (d1);
5595 if (value && DECL_TEMPLATE_TEMPLATE_PARM_P (value))
5600 push_decl_namespace (context);
5601 templ = lookup_name (d1);
5602 templ = maybe_get_template_decl_from_type_decl (templ);
5604 pop_decl_namespace ();
5607 context = DECL_CONTEXT (templ);
5609 else if (TREE_CODE (d1) == TYPE_DECL && MAYBE_CLASS_TYPE_P (TREE_TYPE (d1)))
5611 tree type = TREE_TYPE (d1);
5613 /* If we are declaring a constructor, say A<T>::A<T>, we will get
5614 an implicit typename for the second A. Deal with it. */
5615 if (TREE_CODE (type) == TYPENAME_TYPE && TREE_TYPE (type))
5616 type = TREE_TYPE (type);
5618 if (CLASSTYPE_TEMPLATE_INFO (type))
5620 templ = CLASSTYPE_TI_TEMPLATE (type);
5621 d1 = DECL_NAME (templ);
5624 else if (TREE_CODE (d1) == ENUMERAL_TYPE
5625 || (TYPE_P (d1) && MAYBE_CLASS_TYPE_P (d1)))
5627 templ = TYPE_TI_TEMPLATE (d1);
5628 d1 = DECL_NAME (templ);
5630 else if (TREE_CODE (d1) == TEMPLATE_DECL
5631 && DECL_TEMPLATE_RESULT (d1)
5632 && TREE_CODE (DECL_TEMPLATE_RESULT (d1)) == TYPE_DECL)
5635 d1 = DECL_NAME (templ);
5636 context = DECL_CONTEXT (templ);
5639 /* Issue an error message if we didn't find a template. */
5642 if (complain & tf_error)
5643 error ("%qT is not a template", d1);
5644 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
5647 if (TREE_CODE (templ) != TEMPLATE_DECL
5648 /* Make sure it's a user visible template, if it was named by
5650 || ((complain & tf_user) && !DECL_TEMPLATE_PARM_P (templ)
5651 && !PRIMARY_TEMPLATE_P (templ)))
5653 if (complain & tf_error)
5655 error ("non-template type %qT used as a template", d1);
5657 error ("for template declaration %q+D", in_decl);
5659 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
5662 complain &= ~tf_user;
5664 if (DECL_TEMPLATE_TEMPLATE_PARM_P (templ))
5666 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
5667 template arguments */
5673 parmlist = DECL_INNERMOST_TEMPLATE_PARMS (templ);
5675 /* Consider an example where a template template parameter declared as
5677 template <class T, class U = std::allocator<T> > class TT
5679 The template parameter level of T and U are one level larger than
5680 of TT. To proper process the default argument of U, say when an
5681 instantiation `TT<int>' is seen, we need to build the full
5682 arguments containing {int} as the innermost level. Outer levels,
5683 available when not appearing as default template argument, can be
5684 obtained from the arguments of the enclosing template.
5686 Suppose that TT is later substituted with std::vector. The above
5687 instantiation is `TT<int, std::allocator<T> >' with TT at
5688 level 1, and T at level 2, while the template arguments at level 1
5689 becomes {std::vector} and the inner level 2 is {int}. */
5691 outer = DECL_CONTEXT (templ);
5693 outer = TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (outer)));
5694 else if (current_template_parms)
5695 /* This is an argument of the current template, so we haven't set
5696 DECL_CONTEXT yet. */
5697 outer = current_template_args ();
5700 arglist = add_to_template_args (outer, arglist);
5702 arglist2 = coerce_template_parms (parmlist, arglist, templ,
5704 /*require_all_args=*/true,
5705 /*use_default_args=*/true);
5706 if (arglist2 == error_mark_node
5707 || (!uses_template_parms (arglist2)
5708 && check_instantiated_args (templ, arglist2, complain)))
5709 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
5711 parm = bind_template_template_parm (TREE_TYPE (templ), arglist2);
5712 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, parm);
5716 tree template_type = TREE_TYPE (templ);
5719 tree found = NULL_TREE;
5722 int is_partial_instantiation;
5724 gen_tmpl = most_general_template (templ);
5725 parmlist = DECL_TEMPLATE_PARMS (gen_tmpl);
5726 parm_depth = TMPL_PARMS_DEPTH (parmlist);
5727 arg_depth = TMPL_ARGS_DEPTH (arglist);
5729 if (arg_depth == 1 && parm_depth > 1)
5731 /* We've been given an incomplete set of template arguments.
5734 template <class T> struct S1 {
5735 template <class U> struct S2 {};
5736 template <class U> struct S2<U*> {};
5739 we will be called with an ARGLIST of `U*', but the
5740 TEMPLATE will be `template <class T> template
5741 <class U> struct S1<T>::S2'. We must fill in the missing
5744 = add_outermost_template_args (TYPE_TI_ARGS (TREE_TYPE (templ)),
5746 arg_depth = TMPL_ARGS_DEPTH (arglist);
5749 /* Now we should have enough arguments. */
5750 gcc_assert (parm_depth == arg_depth);
5752 /* From here on, we're only interested in the most general
5756 /* Calculate the BOUND_ARGS. These will be the args that are
5757 actually tsubst'd into the definition to create the
5761 /* We have multiple levels of arguments to coerce, at once. */
5763 int saved_depth = TMPL_ARGS_DEPTH (arglist);
5765 tree bound_args = make_tree_vec (parm_depth);
5767 for (i = saved_depth,
5768 t = DECL_TEMPLATE_PARMS (templ);
5769 i > 0 && t != NULL_TREE;
5770 --i, t = TREE_CHAIN (t))
5772 tree a = coerce_template_parms (TREE_VALUE (t),
5775 /*require_all_args=*/true,
5776 /*use_default_args=*/true);
5778 /* Don't process further if one of the levels fails. */
5779 if (a == error_mark_node)
5781 /* Restore the ARGLIST to its full size. */
5782 TREE_VEC_LENGTH (arglist) = saved_depth;
5783 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
5786 SET_TMPL_ARGS_LEVEL (bound_args, i, a);
5788 /* We temporarily reduce the length of the ARGLIST so
5789 that coerce_template_parms will see only the arguments
5790 corresponding to the template parameters it is
5792 TREE_VEC_LENGTH (arglist)--;
5795 /* Restore the ARGLIST to its full size. */
5796 TREE_VEC_LENGTH (arglist) = saved_depth;
5798 arglist = bound_args;
5802 = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parmlist),
5803 INNERMOST_TEMPLATE_ARGS (arglist),
5806 /*require_all_args=*/true,
5807 /*use_default_args=*/true);
5809 if (arglist == error_mark_node)
5810 /* We were unable to bind the arguments. */
5811 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
5813 /* In the scope of a template class, explicit references to the
5814 template class refer to the type of the template, not any
5815 instantiation of it. For example, in:
5817 template <class T> class C { void f(C<T>); }
5819 the `C<T>' is just the same as `C'. Outside of the
5820 class, however, such a reference is an instantiation. */
5821 if (comp_template_args (TYPE_TI_ARGS (template_type),
5824 found = template_type;
5826 if (!entering_scope && PRIMARY_TEMPLATE_P (templ))
5830 for (ctx = current_class_type;
5831 ctx && TREE_CODE (ctx) != NAMESPACE_DECL;
5833 ? TYPE_CONTEXT (ctx)
5834 : DECL_CONTEXT (ctx)))
5835 if (TYPE_P (ctx) && same_type_p (ctx, template_type))
5838 /* We're not in the scope of the class, so the
5839 TEMPLATE_TYPE is not the type we want after all. */
5845 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, found);
5847 /* If we already have this specialization, return it. */
5848 found = retrieve_specialization (templ, arglist,
5849 /*class_specializations_p=*/false);
5851 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, found);
5853 /* This type is a "partial instantiation" if any of the template
5854 arguments still involve template parameters. Note that we set
5855 IS_PARTIAL_INSTANTIATION for partial specializations as
5857 is_partial_instantiation = uses_template_parms (arglist);
5859 /* If the deduced arguments are invalid, then the binding
5861 if (!is_partial_instantiation
5862 && check_instantiated_args (templ,
5863 INNERMOST_TEMPLATE_ARGS (arglist),
5865 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
5867 if (!is_partial_instantiation
5868 && !PRIMARY_TEMPLATE_P (templ)
5869 && TREE_CODE (CP_DECL_CONTEXT (templ)) == NAMESPACE_DECL)
5871 found = xref_tag_from_type (TREE_TYPE (templ),
5873 /*tag_scope=*/ts_global);
5874 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, found);
5877 context = tsubst (DECL_CONTEXT (templ), arglist,
5880 context = global_namespace;
5882 /* Create the type. */
5883 if (TREE_CODE (template_type) == ENUMERAL_TYPE)
5885 if (!is_partial_instantiation)
5887 set_current_access_from_decl (TYPE_NAME (template_type));
5888 t = start_enum (TYPE_IDENTIFIER (template_type),
5889 tsubst (ENUM_UNDERLYING_TYPE (template_type),
5890 arglist, complain, in_decl),
5891 SCOPED_ENUM_P (template_type));
5895 /* We don't want to call start_enum for this type, since
5896 the values for the enumeration constants may involve
5897 template parameters. And, no one should be interested
5898 in the enumeration constants for such a type. */
5899 t = make_node (ENUMERAL_TYPE);
5900 SET_SCOPED_ENUM_P (t, SCOPED_ENUM_P (template_type));
5905 t = make_class_type (TREE_CODE (template_type));
5906 CLASSTYPE_DECLARED_CLASS (t)
5907 = CLASSTYPE_DECLARED_CLASS (template_type);
5908 SET_CLASSTYPE_IMPLICIT_INSTANTIATION (t);
5909 TYPE_FOR_JAVA (t) = TYPE_FOR_JAVA (template_type);
5911 /* A local class. Make sure the decl gets registered properly. */
5912 if (context == current_function_decl)
5913 pushtag (DECL_NAME (templ), t, /*tag_scope=*/ts_current);
5915 if (comp_template_args (CLASSTYPE_TI_ARGS (template_type), arglist))
5916 /* This instantiation is another name for the primary
5917 template type. Set the TYPE_CANONICAL field
5919 TYPE_CANONICAL (t) = template_type;
5920 else if (any_template_arguments_need_structural_equality_p (arglist))
5921 /* Some of the template arguments require structural
5922 equality testing, so this template class requires
5923 structural equality testing. */
5924 SET_TYPE_STRUCTURAL_EQUALITY (t);
5927 /* If we called start_enum or pushtag above, this information
5928 will already be set up. */
5931 TYPE_CONTEXT (t) = FROB_CONTEXT (context);
5933 type_decl = create_implicit_typedef (DECL_NAME (templ), t);
5934 DECL_CONTEXT (type_decl) = TYPE_CONTEXT (t);
5935 TYPE_STUB_DECL (t) = type_decl;
5936 DECL_SOURCE_LOCATION (type_decl)
5937 = DECL_SOURCE_LOCATION (TYPE_STUB_DECL (template_type));
5940 type_decl = TYPE_NAME (t);
5942 TREE_PRIVATE (type_decl)
5943 = TREE_PRIVATE (TYPE_STUB_DECL (template_type));
5944 TREE_PROTECTED (type_decl)
5945 = TREE_PROTECTED (TYPE_STUB_DECL (template_type));
5946 if (CLASSTYPE_VISIBILITY_SPECIFIED (template_type))
5948 DECL_VISIBILITY_SPECIFIED (type_decl) = 1;
5949 DECL_VISIBILITY (type_decl) = CLASSTYPE_VISIBILITY (template_type);
5952 /* Set up the template information. We have to figure out which
5953 template is the immediate parent if this is a full
5955 if (parm_depth == 1 || is_partial_instantiation
5956 || !PRIMARY_TEMPLATE_P (templ))
5957 /* This case is easy; there are no member templates involved. */
5961 /* This is a full instantiation of a member template. Look
5962 for a partial instantiation of which this is an instance. */
5964 for (found = DECL_TEMPLATE_INSTANTIATIONS (templ);
5965 found; found = TREE_CHAIN (found))
5968 tree tmpl = CLASSTYPE_TI_TEMPLATE (TREE_VALUE (found));
5970 /* We only want partial instantiations, here, not
5971 specializations or full instantiations. */
5972 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_VALUE (found))
5973 || !uses_template_parms (TREE_VALUE (found)))
5976 /* Temporarily reduce by one the number of levels in the
5977 ARGLIST and in FOUND so as to avoid comparing the
5978 last set of arguments. */
5979 TREE_VEC_LENGTH (arglist)--;
5980 TREE_VEC_LENGTH (TREE_PURPOSE (found)) --;
5982 /* See if the arguments match. If they do, then TMPL is
5983 the partial instantiation we want. */
5984 success = comp_template_args (TREE_PURPOSE (found), arglist);
5986 /* Restore the argument vectors to their full size. */
5987 TREE_VEC_LENGTH (arglist)++;
5988 TREE_VEC_LENGTH (TREE_PURPOSE (found))++;
5999 /* There was no partial instantiation. This happens
6000 where C<T> is a member template of A<T> and it's used
6003 template <typename T> struct B { A<T>::C<int> m; };
6006 Create the partial instantiation.
6008 TREE_VEC_LENGTH (arglist)--;
6009 found = tsubst (templ, arglist, complain, NULL_TREE);
6010 TREE_VEC_LENGTH (arglist)++;
6014 SET_TYPE_TEMPLATE_INFO (t, tree_cons (found, arglist, NULL_TREE));
6015 DECL_TEMPLATE_INSTANTIATIONS (templ)
6016 = tree_cons (arglist, t,
6017 DECL_TEMPLATE_INSTANTIATIONS (templ));
6019 if (TREE_CODE (t) == ENUMERAL_TYPE
6020 && !is_partial_instantiation)
6021 /* Now that the type has been registered on the instantiations
6022 list, we set up the enumerators. Because the enumeration
6023 constants may involve the enumeration type itself, we make
6024 sure to register the type first, and then create the
6025 constants. That way, doing tsubst_expr for the enumeration
6026 constants won't result in recursive calls here; we'll find
6027 the instantiation and exit above. */
6028 tsubst_enum (template_type, t, arglist);
6030 if (is_partial_instantiation)
6031 /* If the type makes use of template parameters, the
6032 code that generates debugging information will crash. */
6033 DECL_IGNORED_P (TYPE_STUB_DECL (t)) = 1;
6035 /* Possibly limit visibility based on template args. */
6036 TREE_PUBLIC (type_decl) = 1;
6037 determine_visibility (type_decl);
6039 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, t);
6041 timevar_pop (TV_NAME_LOOKUP);
6048 /* True when we should also visit template parameters that occur in
6049 non-deduced contexts. */
6050 bool include_nondeduced_p;
6051 struct pointer_set_t *visited;
6054 /* Called from for_each_template_parm via walk_tree. */
6057 for_each_template_parm_r (tree *tp, int *walk_subtrees, void *d)
6060 struct pair_fn_data *pfd = (struct pair_fn_data *) d;
6061 tree_fn_t fn = pfd->fn;
6062 void *data = pfd->data;
6065 && (pfd->include_nondeduced_p || TREE_CODE (t) != TYPENAME_TYPE)
6066 && for_each_template_parm (TYPE_CONTEXT (t), fn, data, pfd->visited,
6067 pfd->include_nondeduced_p))
6068 return error_mark_node;
6070 switch (TREE_CODE (t))
6073 if (TYPE_PTRMEMFUNC_P (t))
6079 if (!TYPE_TEMPLATE_INFO (t))
6081 else if (for_each_template_parm (TREE_VALUE (TYPE_TEMPLATE_INFO (t)),
6082 fn, data, pfd->visited,
6083 pfd->include_nondeduced_p))
6084 return error_mark_node;
6088 if (for_each_template_parm (TYPE_MIN_VALUE (t),
6089 fn, data, pfd->visited,
6090 pfd->include_nondeduced_p)
6091 || for_each_template_parm (TYPE_MAX_VALUE (t),
6092 fn, data, pfd->visited,
6093 pfd->include_nondeduced_p))
6094 return error_mark_node;
6098 /* Since we're not going to walk subtrees, we have to do this
6100 if (for_each_template_parm (TYPE_METHOD_BASETYPE (t), fn, data,
6101 pfd->visited, pfd->include_nondeduced_p))
6102 return error_mark_node;
6106 /* Check the return type. */
6107 if (for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
6108 pfd->include_nondeduced_p))
6109 return error_mark_node;
6111 /* Check the parameter types. Since default arguments are not
6112 instantiated until they are needed, the TYPE_ARG_TYPES may
6113 contain expressions that involve template parameters. But,
6114 no-one should be looking at them yet. And, once they're
6115 instantiated, they don't contain template parameters, so
6116 there's no point in looking at them then, either. */
6120 for (parm = TYPE_ARG_TYPES (t); parm; parm = TREE_CHAIN (parm))
6121 if (for_each_template_parm (TREE_VALUE (parm), fn, data,
6122 pfd->visited, pfd->include_nondeduced_p))
6123 return error_mark_node;
6125 /* Since we've already handled the TYPE_ARG_TYPES, we don't
6126 want walk_tree walking into them itself. */
6132 if (pfd->include_nondeduced_p
6133 && for_each_template_parm (TYPE_FIELDS (t), fn, data,
6135 pfd->include_nondeduced_p))
6136 return error_mark_node;
6141 if (DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t)
6142 && for_each_template_parm (DECL_TI_ARGS (t), fn, data,
6143 pfd->visited, pfd->include_nondeduced_p))
6144 return error_mark_node;
6149 if (TREE_CODE (t) == CONST_DECL && DECL_TEMPLATE_PARM_P (t)
6150 && for_each_template_parm (DECL_INITIAL (t), fn, data,
6151 pfd->visited, pfd->include_nondeduced_p))
6152 return error_mark_node;
6153 if (DECL_CONTEXT (t)
6154 && pfd->include_nondeduced_p
6155 && for_each_template_parm (DECL_CONTEXT (t), fn, data,
6156 pfd->visited, pfd->include_nondeduced_p))
6157 return error_mark_node;
6160 case BOUND_TEMPLATE_TEMPLATE_PARM:
6161 /* Record template parameters such as `T' inside `TT<T>'. */
6162 if (for_each_template_parm (TYPE_TI_ARGS (t), fn, data, pfd->visited,
6163 pfd->include_nondeduced_p))
6164 return error_mark_node;
6167 case TEMPLATE_TEMPLATE_PARM:
6168 case TEMPLATE_TYPE_PARM:
6169 case TEMPLATE_PARM_INDEX:
6170 if (fn && (*fn)(t, data))
6171 return error_mark_node;
6173 return error_mark_node;
6177 /* A template template parameter is encountered. */
6178 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t)
6179 && for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
6180 pfd->include_nondeduced_p))
6181 return error_mark_node;
6183 /* Already substituted template template parameter */
6189 || for_each_template_parm (TYPENAME_TYPE_FULLNAME (t), fn,
6191 pfd->include_nondeduced_p))
6192 return error_mark_node;
6196 if (TREE_TYPE (t) && TYPE_PTRMEMFUNC_P (TREE_TYPE (t))
6197 && pfd->include_nondeduced_p
6198 && for_each_template_parm (TYPE_PTRMEMFUNC_FN_TYPE
6199 (TREE_TYPE (t)), fn, data,
6200 pfd->visited, pfd->include_nondeduced_p))
6201 return error_mark_node;
6206 /* If there's no type, then this thing must be some expression
6207 involving template parameters. */
6208 if (!fn && !TREE_TYPE (t))
6209 return error_mark_node;
6214 case REINTERPRET_CAST_EXPR:
6215 case CONST_CAST_EXPR:
6216 case STATIC_CAST_EXPR:
6217 case DYNAMIC_CAST_EXPR:
6221 case PSEUDO_DTOR_EXPR:
6223 return error_mark_node;
6230 /* We didn't find any template parameters we liked. */
6234 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
6235 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
6236 call FN with the parameter and the DATA.
6237 If FN returns nonzero, the iteration is terminated, and
6238 for_each_template_parm returns 1. Otherwise, the iteration
6239 continues. If FN never returns a nonzero value, the value
6240 returned by for_each_template_parm is 0. If FN is NULL, it is
6241 considered to be the function which always returns 1.
6243 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
6244 parameters that occur in non-deduced contexts. When false, only
6245 visits those template parameters that can be deduced. */
6248 for_each_template_parm (tree t, tree_fn_t fn, void* data,
6249 struct pointer_set_t *visited,
6250 bool include_nondeduced_p)
6252 struct pair_fn_data pfd;
6258 pfd.include_nondeduced_p = include_nondeduced_p;
6260 /* Walk the tree. (Conceptually, we would like to walk without
6261 duplicates, but for_each_template_parm_r recursively calls
6262 for_each_template_parm, so we would need to reorganize a fair
6263 bit to use walk_tree_without_duplicates, so we keep our own
6266 pfd.visited = visited;
6268 pfd.visited = pointer_set_create ();
6269 result = cp_walk_tree (&t,
6270 for_each_template_parm_r,
6272 pfd.visited) != NULL_TREE;
6277 pointer_set_destroy (pfd.visited);
6284 /* Returns true if T depends on any template parameter. */
6287 uses_template_parms (tree t)
6290 int saved_processing_template_decl;
6292 saved_processing_template_decl = processing_template_decl;
6293 if (!saved_processing_template_decl)
6294 processing_template_decl = 1;
6296 dependent_p = dependent_type_p (t);
6297 else if (TREE_CODE (t) == TREE_VEC)
6298 dependent_p = any_dependent_template_arguments_p (t);
6299 else if (TREE_CODE (t) == TREE_LIST)
6300 dependent_p = (uses_template_parms (TREE_VALUE (t))
6301 || uses_template_parms (TREE_CHAIN (t)));
6302 else if (TREE_CODE (t) == TYPE_DECL)
6303 dependent_p = dependent_type_p (TREE_TYPE (t));
6306 || TREE_CODE (t) == TEMPLATE_PARM_INDEX
6307 || TREE_CODE (t) == OVERLOAD
6308 || TREE_CODE (t) == BASELINK
6309 || TREE_CODE (t) == IDENTIFIER_NODE
6310 || TREE_CODE (t) == TRAIT_EXPR
6311 || CONSTANT_CLASS_P (t))
6312 dependent_p = (type_dependent_expression_p (t)
6313 || value_dependent_expression_p (t));
6316 gcc_assert (t == error_mark_node);
6317 dependent_p = false;
6320 processing_template_decl = saved_processing_template_decl;
6325 /* Returns true if T depends on any template parameter with level LEVEL. */
6328 uses_template_parms_level (tree t, int level)
6330 return for_each_template_parm (t, template_parm_this_level_p, &level, NULL,
6331 /*include_nondeduced_p=*/true);
6334 static int tinst_depth;
6335 extern int max_tinst_depth;
6336 #ifdef GATHER_STATISTICS
6339 static int tinst_level_tick;
6340 static int last_template_error_tick;
6342 /* We're starting to instantiate D; record the template instantiation context
6343 for diagnostics and to restore it later. */
6346 push_tinst_level (tree d)
6348 struct tinst_level *new_level;
6350 if (tinst_depth >= max_tinst_depth)
6352 /* If the instantiation in question still has unbound template parms,
6353 we don't really care if we can't instantiate it, so just return.
6354 This happens with base instantiation for implicit `typename'. */
6355 if (uses_template_parms (d))
6358 last_template_error_tick = tinst_level_tick;
6359 error ("template instantiation depth exceeds maximum of %d (use "
6360 "-ftemplate-depth-NN to increase the maximum) instantiating %qD",
6361 max_tinst_depth, d);
6363 print_instantiation_context ();
6368 new_level = GGC_NEW (struct tinst_level);
6369 new_level->decl = d;
6370 new_level->locus = input_location;
6371 new_level->in_system_header_p = in_system_header;
6372 new_level->next = current_tinst_level;
6373 current_tinst_level = new_level;
6376 #ifdef GATHER_STATISTICS
6377 if (tinst_depth > depth_reached)
6378 depth_reached = tinst_depth;
6385 /* We're done instantiating this template; return to the instantiation
6389 pop_tinst_level (void)
6391 /* Restore the filename and line number stashed away when we started
6392 this instantiation. */
6393 input_location = current_tinst_level->locus;
6394 current_tinst_level = current_tinst_level->next;
6399 /* We're instantiating a deferred template; restore the template
6400 instantiation context in which the instantiation was requested, which
6401 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
6404 reopen_tinst_level (struct tinst_level *level)
6406 struct tinst_level *t;
6409 for (t = level; t; t = t->next)
6412 current_tinst_level = level;
6417 /* Returns the TINST_LEVEL which gives the original instantiation
6420 struct tinst_level *
6421 outermost_tinst_level (void)
6423 struct tinst_level *level = current_tinst_level;
6426 level = level->next;
6430 /* Returns TRUE if PARM is a parameter of the template TEMPL. */
6433 parameter_of_template_p (tree parm, tree templ)
6438 if (!parm || !templ)
6441 gcc_assert (DECL_TEMPLATE_PARM_P (parm));
6442 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
6444 parms = DECL_TEMPLATE_PARMS (templ);
6445 parms = INNERMOST_TEMPLATE_PARMS (parms);
6447 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
6448 if (parm == TREE_VALUE (TREE_VEC_ELT (parms, i)))
6454 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
6455 vector of template arguments, as for tsubst.
6457 Returns an appropriate tsubst'd friend declaration. */
6460 tsubst_friend_function (tree decl, tree args)
6464 if (TREE_CODE (decl) == FUNCTION_DECL
6465 && DECL_TEMPLATE_INSTANTIATION (decl)
6466 && TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
6467 /* This was a friend declared with an explicit template
6468 argument list, e.g.:
6472 to indicate that f was a template instantiation, not a new
6473 function declaration. Now, we have to figure out what
6474 instantiation of what template. */
6476 tree template_id, arglist, fns;
6479 tree ns = decl_namespace_context (TYPE_MAIN_DECL (current_class_type));
6481 /* Friend functions are looked up in the containing namespace scope.
6482 We must enter that scope, to avoid finding member functions of the
6483 current class with same name. */
6484 push_nested_namespace (ns);
6485 fns = tsubst_expr (DECL_TI_TEMPLATE (decl), args,
6486 tf_warning_or_error, NULL_TREE,
6487 /*integral_constant_expression_p=*/false);
6488 pop_nested_namespace (ns);
6489 arglist = tsubst (DECL_TI_ARGS (decl), args,
6490 tf_warning_or_error, NULL_TREE);
6491 template_id = lookup_template_function (fns, arglist);
6493 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
6494 tmpl = determine_specialization (template_id, new_friend,
6496 /*need_member_template=*/0,
6497 TREE_VEC_LENGTH (args),
6499 return instantiate_template (tmpl, new_args, tf_error);
6502 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
6504 /* The NEW_FRIEND will look like an instantiation, to the
6505 compiler, but is not an instantiation from the point of view of
6506 the language. For example, we might have had:
6508 template <class T> struct S {
6509 template <class U> friend void f(T, U);
6512 Then, in S<int>, template <class U> void f(int, U) is not an
6513 instantiation of anything. */
6514 if (new_friend == error_mark_node)
6515 return error_mark_node;
6517 DECL_USE_TEMPLATE (new_friend) = 0;
6518 if (TREE_CODE (decl) == TEMPLATE_DECL)
6520 DECL_USE_TEMPLATE (DECL_TEMPLATE_RESULT (new_friend)) = 0;
6521 DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (new_friend))
6522 = DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (decl));
6525 /* The mangled name for the NEW_FRIEND is incorrect. The function
6526 is not a template instantiation and should not be mangled like
6527 one. Therefore, we forget the mangling here; we'll recompute it
6528 later if we need it. */
6529 if (TREE_CODE (new_friend) != TEMPLATE_DECL)
6531 SET_DECL_RTL (new_friend, NULL_RTX);
6532 SET_DECL_ASSEMBLER_NAME (new_friend, NULL_TREE);
6535 if (DECL_NAMESPACE_SCOPE_P (new_friend))
6538 tree new_friend_template_info;
6539 tree new_friend_result_template_info;
6541 int new_friend_is_defn;
6543 /* We must save some information from NEW_FRIEND before calling
6544 duplicate decls since that function will free NEW_FRIEND if
6546 new_friend_template_info = DECL_TEMPLATE_INFO (new_friend);
6547 new_friend_is_defn =
6548 (DECL_INITIAL (DECL_TEMPLATE_RESULT
6549 (template_for_substitution (new_friend)))
6551 if (TREE_CODE (new_friend) == TEMPLATE_DECL)
6553 /* This declaration is a `primary' template. */
6554 DECL_PRIMARY_TEMPLATE (new_friend) = new_friend;
6556 new_friend_result_template_info
6557 = DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (new_friend));
6560 new_friend_result_template_info = NULL_TREE;
6562 /* Make the init_value nonzero so pushdecl knows this is a defn. */
6563 if (new_friend_is_defn)
6564 DECL_INITIAL (new_friend) = error_mark_node;
6566 /* Inside pushdecl_namespace_level, we will push into the
6567 current namespace. However, the friend function should go
6568 into the namespace of the template. */
6569 ns = decl_namespace_context (new_friend);
6570 push_nested_namespace (ns);
6571 old_decl = pushdecl_namespace_level (new_friend, /*is_friend=*/true);
6572 pop_nested_namespace (ns);
6574 if (old_decl == error_mark_node)
6575 return error_mark_node;
6577 if (old_decl != new_friend)
6579 /* This new friend declaration matched an existing
6580 declaration. For example, given:
6582 template <class T> void f(T);
6583 template <class U> class C {
6584 template <class T> friend void f(T) {}
6587 the friend declaration actually provides the definition
6588 of `f', once C has been instantiated for some type. So,
6589 old_decl will be the out-of-class template declaration,
6590 while new_friend is the in-class definition.
6592 But, if `f' was called before this point, the
6593 instantiation of `f' will have DECL_TI_ARGS corresponding
6594 to `T' but not to `U', references to which might appear
6595 in the definition of `f'. Previously, the most general
6596 template for an instantiation of `f' was the out-of-class
6597 version; now it is the in-class version. Therefore, we
6598 run through all specialization of `f', adding to their
6599 DECL_TI_ARGS appropriately. In particular, they need a
6600 new set of outer arguments, corresponding to the
6601 arguments for this class instantiation.
6603 The same situation can arise with something like this:
6606 template <class T> class C {
6610 when `C<int>' is instantiated. Now, `f(int)' is defined
6613 if (!new_friend_is_defn)
6614 /* On the other hand, if the in-class declaration does
6615 *not* provide a definition, then we don't want to alter
6616 existing definitions. We can just leave everything
6621 /* Overwrite whatever template info was there before, if
6622 any, with the new template information pertaining to
6624 DECL_TEMPLATE_INFO (old_decl) = new_friend_template_info;
6626 if (TREE_CODE (old_decl) != TEMPLATE_DECL)
6627 reregister_specialization (new_friend,
6628 most_general_template (old_decl),
6633 tree new_friend_args;
6635 DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (old_decl))
6636 = new_friend_result_template_info;
6638 new_friend_args = TI_ARGS (new_friend_template_info);
6639 for (t = DECL_TEMPLATE_SPECIALIZATIONS (old_decl);
6643 tree spec = TREE_VALUE (t);
6646 = add_outermost_template_args (new_friend_args,
6647 DECL_TI_ARGS (spec));
6650 /* Now, since specializations are always supposed to
6651 hang off of the most general template, we must move
6653 t = most_general_template (old_decl);
6656 DECL_TEMPLATE_SPECIALIZATIONS (t)
6657 = chainon (DECL_TEMPLATE_SPECIALIZATIONS (t),
6658 DECL_TEMPLATE_SPECIALIZATIONS (old_decl));
6659 DECL_TEMPLATE_SPECIALIZATIONS (old_decl) = NULL_TREE;
6664 /* The information from NEW_FRIEND has been merged into OLD_DECL
6665 by duplicate_decls. */
6666 new_friend = old_decl;
6671 tree context = DECL_CONTEXT (new_friend);
6675 template <class T> class C {
6676 template <class U> friend void C1<U>::f (); // case 1
6677 friend void C2<T>::f (); // case 2
6679 we only need to make sure CONTEXT is a complete type for
6680 case 2. To distinguish between the two cases, we note that
6681 CONTEXT of case 1 remains dependent type after tsubst while
6682 this isn't true for case 2. */
6683 ++processing_template_decl;
6684 dependent_p = dependent_type_p (context);
6685 --processing_template_decl;
6688 && !complete_type_or_else (context, NULL_TREE))
6689 return error_mark_node;
6691 if (COMPLETE_TYPE_P (context))
6693 /* Check to see that the declaration is really present, and,
6694 possibly obtain an improved declaration. */
6695 tree fn = check_classfn (context,
6696 new_friend, NULL_TREE);
6706 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
6707 template arguments, as for tsubst.
6709 Returns an appropriate tsubst'd friend type or error_mark_node on
6713 tsubst_friend_class (tree friend_tmpl, tree args)
6719 context = DECL_CONTEXT (friend_tmpl);
6723 if (TREE_CODE (context) == NAMESPACE_DECL)
6724 push_nested_namespace (context);
6726 push_nested_class (tsubst (context, args, tf_none, NULL_TREE));
6729 /* Look for a class template declaration. We look for hidden names
6730 because two friend declarations of the same template are the
6731 same. For example, in:
6734 template <typename> friend class F;
6736 template <typename> struct B {
6737 template <typename> friend class F;
6740 both F templates are the same. */
6741 tmpl = lookup_name_real (DECL_NAME (friend_tmpl), 0, 0,
6742 /*block_p=*/true, 0,
6743 LOOKUP_COMPLAIN | LOOKUP_HIDDEN);
6745 /* But, if we don't find one, it might be because we're in a
6746 situation like this:
6754 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
6755 for `S<int>', not the TEMPLATE_DECL. */
6756 if (!tmpl || !DECL_CLASS_TEMPLATE_P (tmpl))
6758 tmpl = lookup_name_prefer_type (DECL_NAME (friend_tmpl), 1);
6759 tmpl = maybe_get_template_decl_from_type_decl (tmpl);
6762 if (tmpl && DECL_CLASS_TEMPLATE_P (tmpl))
6764 /* The friend template has already been declared. Just
6765 check to see that the declarations match, and install any new
6766 default parameters. We must tsubst the default parameters,
6767 of course. We only need the innermost template parameters
6768 because that is all that redeclare_class_template will look
6770 if (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (friend_tmpl))
6771 > TMPL_ARGS_DEPTH (args))
6774 location_t saved_input_location;
6775 parms = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_tmpl),
6776 args, tf_warning_or_error);
6778 saved_input_location = input_location;
6779 input_location = DECL_SOURCE_LOCATION (friend_tmpl);
6780 redeclare_class_template (TREE_TYPE (tmpl), parms);
6781 input_location = saved_input_location;
6785 friend_type = TREE_TYPE (tmpl);
6789 /* The friend template has not already been declared. In this
6790 case, the instantiation of the template class will cause the
6791 injection of this template into the global scope. */
6792 tmpl = tsubst (friend_tmpl, args, tf_warning_or_error, NULL_TREE);
6793 if (tmpl == error_mark_node)
6794 return error_mark_node;
6796 /* The new TMPL is not an instantiation of anything, so we
6797 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
6798 the new type because that is supposed to be the corresponding
6799 template decl, i.e., TMPL. */
6800 DECL_USE_TEMPLATE (tmpl) = 0;
6801 DECL_TEMPLATE_INFO (tmpl) = NULL_TREE;
6802 CLASSTYPE_USE_TEMPLATE (TREE_TYPE (tmpl)) = 0;
6803 CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl))
6804 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl)));
6806 /* Inject this template into the global scope. */
6807 friend_type = TREE_TYPE (pushdecl_top_level_maybe_friend (tmpl, true));
6812 if (TREE_CODE (context) == NAMESPACE_DECL)
6813 pop_nested_namespace (context);
6815 pop_nested_class ();
6821 /* Returns zero if TYPE cannot be completed later due to circularity.
6822 Otherwise returns one. */
6825 can_complete_type_without_circularity (tree type)
6827 if (type == NULL_TREE || type == error_mark_node)
6829 else if (COMPLETE_TYPE_P (type))
6831 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
6832 return can_complete_type_without_circularity (TREE_TYPE (type));
6833 else if (CLASS_TYPE_P (type)
6834 && TYPE_BEING_DEFINED (TYPE_MAIN_VARIANT (type)))
6840 /* Apply any attributes which had to be deferred until instantiation
6841 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
6842 ARGS, COMPLAIN, IN_DECL are as tsubst. */
6845 apply_late_template_attributes (tree *decl_p, tree attributes, int attr_flags,
6846 tree args, tsubst_flags_t complain, tree in_decl)
6848 tree last_dep = NULL_TREE;
6852 for (t = attributes; t; t = TREE_CHAIN (t))
6853 if (ATTR_IS_DEPENDENT (t))
6856 attributes = copy_list (attributes);
6860 if (DECL_P (*decl_p))
6862 if (TREE_TYPE (*decl_p) == error_mark_node)
6864 p = &DECL_ATTRIBUTES (*decl_p);
6867 p = &TYPE_ATTRIBUTES (*decl_p);
6871 tree late_attrs = NULL_TREE;
6872 tree *q = &late_attrs;
6874 for (*p = attributes; *p; )
6877 if (ATTR_IS_DEPENDENT (t))
6879 *p = TREE_CHAIN (t);
6880 TREE_CHAIN (t) = NULL_TREE;
6881 /* If the first attribute argument is an identifier, don't
6882 pass it through tsubst. Attributes like mode, format,
6883 cleanup and several target specific attributes expect it
6886 && TREE_CODE (TREE_VALUE (t)) == TREE_LIST
6887 && TREE_VALUE (TREE_VALUE (t))
6888 && (TREE_CODE (TREE_VALUE (TREE_VALUE (t)))
6889 == IDENTIFIER_NODE))
6892 = tsubst_expr (TREE_CHAIN (TREE_VALUE (t)), args, complain,
6894 /*integral_constant_expression_p=*/false);
6895 if (chain != TREE_CHAIN (TREE_VALUE (t)))
6897 = tree_cons (NULL_TREE, TREE_VALUE (TREE_VALUE (t)),
6902 = tsubst_expr (TREE_VALUE (t), args, complain, in_decl,
6903 /*integral_constant_expression_p=*/false);
6905 q = &TREE_CHAIN (t);
6908 p = &TREE_CHAIN (t);
6911 cplus_decl_attributes (decl_p, late_attrs, attr_flags);
6916 instantiate_class_template (tree type)
6918 tree templ, args, pattern, t, member;
6923 if (type == error_mark_node)
6924 return error_mark_node;
6926 if (TYPE_BEING_DEFINED (type)
6927 || COMPLETE_TYPE_P (type)
6928 || dependent_type_p (type))
6931 /* Figure out which template is being instantiated. */
6932 templ = most_general_template (CLASSTYPE_TI_TEMPLATE (type));
6933 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
6935 /* Determine what specialization of the original template to
6937 t = most_specialized_class (type, templ);
6938 if (t == error_mark_node)
6940 TYPE_BEING_DEFINED (type) = 1;
6941 return error_mark_node;
6945 /* This TYPE is actually an instantiation of a partial
6946 specialization. We replace the innermost set of ARGS with
6947 the arguments appropriate for substitution. For example,
6950 template <class T> struct S {};
6951 template <class T> struct S<T*> {};
6953 and supposing that we are instantiating S<int*>, ARGS will
6954 presently be {int*} -- but we need {int}. */
6955 pattern = TREE_TYPE (t);
6956 args = TREE_PURPOSE (t);
6960 pattern = TREE_TYPE (templ);
6961 args = CLASSTYPE_TI_ARGS (type);
6964 /* If the template we're instantiating is incomplete, then clearly
6965 there's nothing we can do. */
6966 if (!COMPLETE_TYPE_P (pattern))
6969 /* If we've recursively instantiated too many templates, stop. */
6970 if (! push_tinst_level (type))
6973 /* Now we're really doing the instantiation. Mark the type as in
6974 the process of being defined. */
6975 TYPE_BEING_DEFINED (type) = 1;
6977 /* We may be in the middle of deferred access check. Disable
6979 push_deferring_access_checks (dk_no_deferred);
6981 push_to_top_level ();
6983 SET_CLASSTYPE_INTERFACE_UNKNOWN (type);
6985 /* Set the input location to the template definition. This is needed
6986 if tsubsting causes an error. */
6987 typedecl = TYPE_MAIN_DECL (type);
6988 input_location = DECL_SOURCE_LOCATION (typedecl);
6990 TYPE_HAS_USER_CONSTRUCTOR (type) = TYPE_HAS_USER_CONSTRUCTOR (pattern);
6991 TYPE_HAS_NEW_OPERATOR (type) = TYPE_HAS_NEW_OPERATOR (pattern);
6992 TYPE_HAS_ARRAY_NEW_OPERATOR (type) = TYPE_HAS_ARRAY_NEW_OPERATOR (pattern);
6993 TYPE_GETS_DELETE (type) = TYPE_GETS_DELETE (pattern);
6994 TYPE_HAS_ASSIGN_REF (type) = TYPE_HAS_ASSIGN_REF (pattern);
6995 TYPE_HAS_CONST_ASSIGN_REF (type) = TYPE_HAS_CONST_ASSIGN_REF (pattern);
6996 TYPE_HAS_INIT_REF (type) = TYPE_HAS_INIT_REF (pattern);
6997 TYPE_HAS_CONST_INIT_REF (type) = TYPE_HAS_CONST_INIT_REF (pattern);
6998 TYPE_HAS_DEFAULT_CONSTRUCTOR (type) = TYPE_HAS_DEFAULT_CONSTRUCTOR (pattern);
6999 TYPE_HAS_CONVERSION (type) = TYPE_HAS_CONVERSION (pattern);
7000 TYPE_PACKED (type) = TYPE_PACKED (pattern);
7001 TYPE_ALIGN (type) = TYPE_ALIGN (pattern);
7002 TYPE_USER_ALIGN (type) = TYPE_USER_ALIGN (pattern);
7003 TYPE_FOR_JAVA (type) = TYPE_FOR_JAVA (pattern); /* For libjava's JArray<T> */
7004 if (ANON_AGGR_TYPE_P (pattern))
7005 SET_ANON_AGGR_TYPE_P (type);
7006 if (CLASSTYPE_VISIBILITY_SPECIFIED (pattern))
7008 CLASSTYPE_VISIBILITY_SPECIFIED (type) = 1;
7009 CLASSTYPE_VISIBILITY (type) = CLASSTYPE_VISIBILITY (pattern);
7012 pbinfo = TYPE_BINFO (pattern);
7014 /* We should never instantiate a nested class before its enclosing
7015 class; we need to look up the nested class by name before we can
7016 instantiate it, and that lookup should instantiate the enclosing
7018 gcc_assert (!DECL_CLASS_SCOPE_P (TYPE_MAIN_DECL (pattern))
7019 || COMPLETE_TYPE_P (TYPE_CONTEXT (type))
7020 || TYPE_BEING_DEFINED (TYPE_CONTEXT (type)));
7022 base_list = NULL_TREE;
7023 if (BINFO_N_BASE_BINFOS (pbinfo))
7026 tree context = TYPE_CONTEXT (type);
7030 /* We must enter the scope containing the type, as that is where
7031 the accessibility of types named in dependent bases are
7033 pushed_scope = push_scope (context ? context : global_namespace);
7035 /* Substitute into each of the bases to determine the actual
7037 for (i = 0; BINFO_BASE_ITERATE (pbinfo, i, pbase_binfo); i++)
7040 tree access = BINFO_BASE_ACCESS (pbinfo, i);
7041 tree expanded_bases = NULL_TREE;
7044 if (PACK_EXPANSION_P (BINFO_TYPE (pbase_binfo)))
7047 tsubst_pack_expansion (BINFO_TYPE (pbase_binfo),
7048 args, tf_error, NULL_TREE);
7049 if (expanded_bases == error_mark_node)
7052 len = TREE_VEC_LENGTH (expanded_bases);
7055 for (idx = 0; idx < len; idx++)
7058 /* Extract the already-expanded base class. */
7059 base = TREE_VEC_ELT (expanded_bases, idx);
7061 /* Substitute to figure out the base class. */
7062 base = tsubst (BINFO_TYPE (pbase_binfo), args, tf_error,
7065 if (base == error_mark_node)
7068 base_list = tree_cons (access, base, base_list);
7069 if (BINFO_VIRTUAL_P (pbase_binfo))
7070 TREE_TYPE (base_list) = integer_type_node;
7074 /* The list is now in reverse order; correct that. */
7075 base_list = nreverse (base_list);
7078 pop_scope (pushed_scope);
7080 /* Now call xref_basetypes to set up all the base-class
7082 xref_basetypes (type, base_list);
7084 apply_late_template_attributes (&type, TYPE_ATTRIBUTES (pattern),
7085 (int) ATTR_FLAG_TYPE_IN_PLACE,
7086 args, tf_error, NULL_TREE);
7088 /* Now that our base classes are set up, enter the scope of the
7089 class, so that name lookups into base classes, etc. will work
7090 correctly. This is precisely analogous to what we do in
7091 begin_class_definition when defining an ordinary non-template
7092 class, except we also need to push the enclosing classes. */
7093 push_nested_class (type);
7095 /* Now members are processed in the order of declaration. */
7096 for (member = CLASSTYPE_DECL_LIST (pattern);
7097 member; member = TREE_CHAIN (member))
7099 tree t = TREE_VALUE (member);
7101 if (TREE_PURPOSE (member))
7105 /* Build new CLASSTYPE_NESTED_UTDS. */
7108 bool class_template_p;
7110 class_template_p = (TREE_CODE (t) != ENUMERAL_TYPE
7111 && TYPE_LANG_SPECIFIC (t)
7112 && CLASSTYPE_IS_TEMPLATE (t));
7113 /* If the member is a class template, then -- even after
7114 substitution -- there may be dependent types in the
7115 template argument list for the class. We increment
7116 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
7117 that function will assume that no types are dependent
7118 when outside of a template. */
7119 if (class_template_p)
7120 ++processing_template_decl;
7121 newtag = tsubst (t, args, tf_error, NULL_TREE);
7122 if (class_template_p)
7123 --processing_template_decl;
7124 if (newtag == error_mark_node)
7127 if (TREE_CODE (newtag) != ENUMERAL_TYPE)
7129 tree name = TYPE_IDENTIFIER (t);
7131 if (class_template_p)
7132 /* Unfortunately, lookup_template_class sets
7133 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
7134 instantiation (i.e., for the type of a member
7135 template class nested within a template class.)
7136 This behavior is required for
7137 maybe_process_partial_specialization to work
7138 correctly, but is not accurate in this case;
7139 the TAG is not an instantiation of anything.
7140 (The corresponding TEMPLATE_DECL is an
7141 instantiation, but the TYPE is not.) */
7142 CLASSTYPE_USE_TEMPLATE (newtag) = 0;
7144 /* Now, we call pushtag to put this NEWTAG into the scope of
7145 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
7146 pushtag calling push_template_decl. We don't have to do
7147 this for enums because it will already have been done in
7150 SET_IDENTIFIER_TYPE_VALUE (name, newtag);
7151 pushtag (name, newtag, /*tag_scope=*/ts_current);
7154 else if (TREE_CODE (t) == FUNCTION_DECL
7155 || DECL_FUNCTION_TEMPLATE_P (t))
7157 /* Build new TYPE_METHODS. */
7160 if (TREE_CODE (t) == TEMPLATE_DECL)
7161 ++processing_template_decl;
7162 r = tsubst (t, args, tf_error, NULL_TREE);
7163 if (TREE_CODE (t) == TEMPLATE_DECL)
7164 --processing_template_decl;
7165 set_current_access_from_decl (r);
7166 finish_member_declaration (r);
7170 /* Build new TYPE_FIELDS. */
7171 if (TREE_CODE (t) == STATIC_ASSERT)
7174 tsubst_expr (STATIC_ASSERT_CONDITION (t), args,
7175 tf_warning_or_error, NULL_TREE,
7176 /*integral_constant_expression_p=*/true);
7177 finish_static_assert (condition,
7178 STATIC_ASSERT_MESSAGE (t),
7179 STATIC_ASSERT_SOURCE_LOCATION (t),
7182 else if (TREE_CODE (t) != CONST_DECL)
7186 /* The file and line for this declaration, to
7187 assist in error message reporting. Since we
7188 called push_tinst_level above, we don't need to
7190 input_location = DECL_SOURCE_LOCATION (t);
7192 if (TREE_CODE (t) == TEMPLATE_DECL)
7193 ++processing_template_decl;
7194 r = tsubst (t, args, tf_warning_or_error, NULL_TREE);
7195 if (TREE_CODE (t) == TEMPLATE_DECL)
7196 --processing_template_decl;
7197 if (TREE_CODE (r) == VAR_DECL)
7201 [t]he initialization (and any associated
7202 side-effects) of a static data member does
7203 not occur unless the static data member is
7204 itself used in a way that requires the
7205 definition of the static data member to
7208 Therefore, we do not substitute into the
7209 initialized for the static data member here. */
7210 finish_static_data_member_decl
7213 /*init_const_expr_p=*/false,
7214 /*asmspec_tree=*/NULL_TREE,
7216 if (DECL_INITIALIZED_IN_CLASS_P (r))
7217 check_static_variable_definition (r, TREE_TYPE (r));
7219 else if (TREE_CODE (r) == FIELD_DECL)
7221 /* Determine whether R has a valid type and can be
7222 completed later. If R is invalid, then it is
7223 replaced by error_mark_node so that it will not be
7224 added to TYPE_FIELDS. */
7225 tree rtype = TREE_TYPE (r);
7226 if (can_complete_type_without_circularity (rtype))
7227 complete_type (rtype);
7229 if (!COMPLETE_TYPE_P (rtype))
7231 cxx_incomplete_type_error (r, rtype);
7232 r = error_mark_node;
7236 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
7237 such a thing will already have been added to the field
7238 list by tsubst_enum in finish_member_declaration in the
7239 CLASSTYPE_NESTED_UTDS case above. */
7240 if (!(TREE_CODE (r) == TYPE_DECL
7241 && TREE_CODE (TREE_TYPE (r)) == ENUMERAL_TYPE
7242 && DECL_ARTIFICIAL (r)))
7244 set_current_access_from_decl (r);
7245 finish_member_declaration (r);
7252 if (TYPE_P (t) || DECL_CLASS_TEMPLATE_P (t))
7254 /* Build new CLASSTYPE_FRIEND_CLASSES. */
7256 tree friend_type = t;
7257 bool adjust_processing_template_decl = false;
7259 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
7261 /* template <class T> friend class C; */
7262 friend_type = tsubst_friend_class (friend_type, args);
7263 adjust_processing_template_decl = true;
7265 else if (TREE_CODE (friend_type) == UNBOUND_CLASS_TEMPLATE)
7267 /* template <class T> friend class C::D; */
7268 friend_type = tsubst (friend_type, args,
7269 tf_warning_or_error, NULL_TREE);
7270 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
7271 friend_type = TREE_TYPE (friend_type);
7272 adjust_processing_template_decl = true;
7274 else if (TREE_CODE (friend_type) == TYPENAME_TYPE)
7276 /* This could be either
7280 when dependent_type_p is false or
7282 template <class U> friend class T::C;
7285 friend_type = tsubst (friend_type, args,
7286 tf_warning_or_error, NULL_TREE);
7287 /* Bump processing_template_decl for correct
7288 dependent_type_p calculation. */
7289 ++processing_template_decl;
7290 if (dependent_type_p (friend_type))
7291 adjust_processing_template_decl = true;
7292 --processing_template_decl;
7294 else if (!CLASSTYPE_USE_TEMPLATE (friend_type)
7295 && hidden_name_p (TYPE_NAME (friend_type)))
7299 where C hasn't been declared yet. Let's lookup name
7300 from namespace scope directly, bypassing any name that
7301 come from dependent base class. */
7302 tree ns = decl_namespace_context (TYPE_MAIN_DECL (friend_type));
7304 /* The call to xref_tag_from_type does injection for friend
7306 push_nested_namespace (ns);
7308 xref_tag_from_type (friend_type, NULL_TREE,
7309 /*tag_scope=*/ts_current);
7310 pop_nested_namespace (ns);
7312 else if (uses_template_parms (friend_type))
7313 /* friend class C<T>; */
7314 friend_type = tsubst (friend_type, args,
7315 tf_warning_or_error, NULL_TREE);
7320 where C is already declared or
7322 friend class C<int>;
7324 We don't have to do anything in these cases. */
7326 if (adjust_processing_template_decl)
7327 /* Trick make_friend_class into realizing that the friend
7328 we're adding is a template, not an ordinary class. It's
7329 important that we use make_friend_class since it will
7330 perform some error-checking and output cross-reference
7332 ++processing_template_decl;
7334 if (friend_type != error_mark_node)
7335 make_friend_class (type, friend_type, /*complain=*/false);
7337 if (adjust_processing_template_decl)
7338 --processing_template_decl;
7342 /* Build new DECL_FRIENDLIST. */
7345 /* The file and line for this declaration, to
7346 assist in error message reporting. Since we
7347 called push_tinst_level above, we don't need to
7349 input_location = DECL_SOURCE_LOCATION (t);
7351 if (TREE_CODE (t) == TEMPLATE_DECL)
7353 ++processing_template_decl;
7354 push_deferring_access_checks (dk_no_check);
7357 r = tsubst_friend_function (t, args);
7358 add_friend (type, r, /*complain=*/false);
7359 if (TREE_CODE (t) == TEMPLATE_DECL)
7361 pop_deferring_access_checks ();
7362 --processing_template_decl;
7368 /* Set the file and line number information to whatever is given for
7369 the class itself. This puts error messages involving generated
7370 implicit functions at a predictable point, and the same point
7371 that would be used for non-template classes. */
7372 input_location = DECL_SOURCE_LOCATION (typedecl);
7374 unreverse_member_declarations (type);
7375 finish_struct_1 (type);
7376 TYPE_BEING_DEFINED (type) = 0;
7378 /* Now that the class is complete, instantiate default arguments for
7379 any member functions. We don't do this earlier because the
7380 default arguments may reference members of the class. */
7381 if (!PRIMARY_TEMPLATE_P (templ))
7382 for (t = TYPE_METHODS (type); t; t = TREE_CHAIN (t))
7383 if (TREE_CODE (t) == FUNCTION_DECL
7384 /* Implicitly generated member functions will not have template
7385 information; they are not instantiations, but instead are
7386 created "fresh" for each instantiation. */
7387 && DECL_TEMPLATE_INFO (t))
7388 tsubst_default_arguments (t);
7390 pop_nested_class ();
7391 pop_from_top_level ();
7392 pop_deferring_access_checks ();
7395 /* The vtable for a template class can be emitted in any translation
7396 unit in which the class is instantiated. When there is no key
7397 method, however, finish_struct_1 will already have added TYPE to
7398 the keyed_classes list. */
7399 if (TYPE_CONTAINS_VPTR_P (type) && CLASSTYPE_KEY_METHOD (type))
7400 keyed_classes = tree_cons (NULL_TREE, type, keyed_classes);
7406 tsubst_template_arg (tree t, tree args, tsubst_flags_t complain, tree in_decl)
7412 else if (TYPE_P (t))
7413 r = tsubst (t, args, complain, in_decl);
7416 r = tsubst_expr (t, args, complain, in_decl,
7417 /*integral_constant_expression_p=*/true);
7418 r = fold_non_dependent_expr (r);
7423 /* Substitute ARGS into T, which is an pack expansion
7424 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
7425 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
7426 (if only a partial substitution could be performed) or
7427 ERROR_MARK_NODE if there was an error. */
7429 tsubst_pack_expansion (tree t, tree args, tsubst_flags_t complain,
7433 tree pack, packs = NULL_TREE, unsubstituted_packs = NULL_TREE;
7434 tree first_arg_pack; int i, len = -1;
7438 gcc_assert (PACK_EXPANSION_P (t));
7439 pattern = PACK_EXPANSION_PATTERN (t);
7441 /* Determine the argument packs that will instantiate the parameter
7442 packs used in the expansion expression. While we're at it,
7443 compute the number of arguments to be expanded and make sure it
7445 for (pack = PACK_EXPANSION_PARAMETER_PACKS (t); pack;
7446 pack = TREE_CHAIN (pack))
7448 tree parm_pack = TREE_VALUE (pack);
7449 tree arg_pack = NULL_TREE;
7450 tree orig_arg = NULL_TREE;
7452 if (TREE_CODE (parm_pack) == PARM_DECL)
7453 arg_pack = retrieve_local_specialization (parm_pack);
7456 int level, idx, levels;
7457 template_parm_level_and_index (parm_pack, &level, &idx);
7459 levels = TMPL_ARGS_DEPTH (args);
7460 if (level <= levels)
7461 arg_pack = TMPL_ARG (args, level, idx);
7464 orig_arg = arg_pack;
7465 if (arg_pack && TREE_CODE (arg_pack) == ARGUMENT_PACK_SELECT)
7466 arg_pack = ARGUMENT_PACK_SELECT_FROM_PACK (arg_pack);
7468 if (arg_pack && !ARGUMENT_PACK_P (arg_pack))
7469 /* This can only happen if we forget to expand an argument
7470 pack somewhere else. Just return an error, silently. */
7472 result = make_tree_vec (1);
7473 TREE_VEC_ELT (result, 0) = error_mark_node;
7478 && TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack)) == 1
7479 && PACK_EXPANSION_P (TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0)))
7481 tree expansion = TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0);
7482 tree pattern = PACK_EXPANSION_PATTERN (expansion);
7483 if ((TYPE_P (pattern) && same_type_p (pattern, parm_pack))
7484 || (!TYPE_P (pattern) && cp_tree_equal (parm_pack, pattern)))
7485 /* The argument pack that the parameter maps to is just an
7486 expansion of the parameter itself, such as one would
7487 find in the implicit typedef of a class inside the
7488 class itself. Consider this parameter "unsubstituted",
7489 so that we will maintain the outer pack expansion. */
7490 arg_pack = NULL_TREE;
7496 TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack));
7498 /* It's all-or-nothing with incomplete argument packs. */
7499 if (incomplete && !ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
7500 return error_mark_node;
7502 if (ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
7508 first_arg_pack = arg_pack;
7510 else if (len != my_len)
7512 if (TREE_CODE (t) == TYPE_PACK_EXPANSION)
7513 error ("mismatched argument pack lengths while expanding "
7517 error ("mismatched argument pack lengths while expanding "
7520 return error_mark_node;
7523 /* Keep track of the parameter packs and their corresponding
7525 packs = tree_cons (parm_pack, arg_pack, packs);
7526 TREE_TYPE (packs) = orig_arg;
7529 /* We can't substitute for this parameter pack. */
7530 unsubstituted_packs = tree_cons (TREE_PURPOSE (pack),
7532 unsubstituted_packs);
7535 /* We cannot expand this expansion expression, because we don't have
7536 all of the argument packs we need. Substitute into the pattern
7537 and return a PACK_EXPANSION_*. The caller will need to deal with
7539 if (unsubstituted_packs)
7540 return make_pack_expansion (tsubst (pattern, args, complain,
7543 /* We could not find any argument packs that work. */
7545 return error_mark_node;
7547 /* For each argument in each argument pack, substitute into the
7549 result = make_tree_vec (len + incomplete);
7550 for (i = 0; i < len + incomplete; ++i)
7552 /* For parameter pack, change the substitution of the parameter
7553 pack to the ith argument in its argument pack, then expand
7555 for (pack = packs; pack; pack = TREE_CHAIN (pack))
7557 tree parm = TREE_PURPOSE (pack);
7559 if (TREE_CODE (parm) == PARM_DECL)
7561 /* Select the Ith argument from the pack. */
7562 tree arg = make_node (ARGUMENT_PACK_SELECT);
7563 ARGUMENT_PACK_SELECT_FROM_PACK (arg) = TREE_VALUE (pack);
7564 ARGUMENT_PACK_SELECT_INDEX (arg) = i;
7566 register_local_specialization (arg, parm);
7572 template_parm_level_and_index (parm, &level, &idx);
7576 /* Select the Ith argument from the pack. */
7577 value = make_node (ARGUMENT_PACK_SELECT);
7578 ARGUMENT_PACK_SELECT_FROM_PACK (value) = TREE_VALUE (pack);
7579 ARGUMENT_PACK_SELECT_INDEX (value) = i;
7582 /* Update the corresponding argument. */
7583 TMPL_ARG (args, level, idx) = value;
7587 /* Substitute into the PATTERN with the altered arguments. */
7588 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
7589 TREE_VEC_ELT (result, i) =
7590 tsubst_expr (pattern, args, complain, in_decl,
7591 /*integral_constant_expression_p=*/false);
7593 TREE_VEC_ELT (result, i) = tsubst (pattern, args, complain, in_decl);
7596 /* When we have incomplete argument packs, the last "expanded"
7597 result is itself a pack expansion, which allows us
7598 to deduce more arguments. */
7599 TREE_VEC_ELT (result, i) =
7600 make_pack_expansion (TREE_VEC_ELT (result, i));
7602 if (TREE_VEC_ELT (result, i) == error_mark_node)
7604 result = error_mark_node;
7609 /* Update ARGS to restore the substitution from parameter packs to
7610 their argument packs. */
7611 for (pack = packs; pack; pack = TREE_CHAIN (pack))
7613 tree parm = TREE_PURPOSE (pack);
7615 if (TREE_CODE (parm) == PARM_DECL)
7616 register_local_specialization (TREE_TYPE (pack), parm);
7620 template_parm_level_and_index (parm, &level, &idx);
7622 /* Update the corresponding argument. */
7623 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
7624 TREE_VEC_ELT (TREE_VEC_ELT (args, level -1 ), idx) =
7627 TREE_VEC_ELT (args, idx) = TREE_TYPE (pack);
7634 /* Substitute ARGS into the vector or list of template arguments T. */
7637 tsubst_template_args (tree t, tree args, tsubst_flags_t complain, tree in_decl)
7640 int len = TREE_VEC_LENGTH (t);
7641 int need_new = 0, i, expanded_len_adjust = 0, out;
7642 tree *elts = (tree *) alloca (len * sizeof (tree));
7644 for (i = 0; i < len; i++)
7646 tree orig_arg = TREE_VEC_ELT (t, i);
7649 if (TREE_CODE (orig_arg) == TREE_VEC)
7650 new_arg = tsubst_template_args (orig_arg, args, complain, in_decl);
7651 else if (PACK_EXPANSION_P (orig_arg))
7653 /* Substitute into an expansion expression. */
7654 new_arg = tsubst_pack_expansion (orig_arg, args, complain, in_decl);
7656 if (TREE_CODE (new_arg) == TREE_VEC)
7657 /* Add to the expanded length adjustment the number of
7658 expanded arguments. We subtract one from this
7659 measurement, because the argument pack expression
7660 itself is already counted as 1 in
7661 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
7662 the argument pack is empty. */
7663 expanded_len_adjust += TREE_VEC_LENGTH (new_arg) - 1;
7665 else if (ARGUMENT_PACK_P (orig_arg))
7667 /* Substitute into each of the arguments. */
7668 new_arg = make_node (TREE_CODE (orig_arg));
7670 SET_ARGUMENT_PACK_ARGS (
7672 tsubst_template_args (ARGUMENT_PACK_ARGS (orig_arg),
7673 args, complain, in_decl));
7675 if (ARGUMENT_PACK_ARGS (new_arg) == error_mark_node)
7676 new_arg = error_mark_node;
7678 if (TREE_CODE (new_arg) == NONTYPE_ARGUMENT_PACK) {
7679 TREE_TYPE (new_arg) = tsubst (TREE_TYPE (orig_arg), args,
7681 TREE_CONSTANT (new_arg) = TREE_CONSTANT (orig_arg);
7683 if (TREE_TYPE (new_arg) == error_mark_node)
7684 new_arg = error_mark_node;
7688 new_arg = tsubst_template_arg (orig_arg, args, complain, in_decl);
7690 if (new_arg == error_mark_node)
7691 return error_mark_node;
7694 if (new_arg != orig_arg)
7701 /* Make space for the expanded arguments coming from template
7703 t = make_tree_vec (len + expanded_len_adjust);
7704 for (i = 0, out = 0; i < len; i++)
7706 if ((PACK_EXPANSION_P (TREE_VEC_ELT (orig_t, i))
7707 || ARGUMENT_PACK_P (TREE_VEC_ELT (orig_t, i)))
7708 && TREE_CODE (elts[i]) == TREE_VEC)
7712 /* Now expand the template argument pack "in place". */
7713 for (idx = 0; idx < TREE_VEC_LENGTH (elts[i]); idx++, out++)
7714 TREE_VEC_ELT (t, out) = TREE_VEC_ELT (elts[i], idx);
7718 TREE_VEC_ELT (t, out) = elts[i];
7726 /* Return the result of substituting ARGS into the template parameters
7727 given by PARMS. If there are m levels of ARGS and m + n levels of
7728 PARMS, then the result will contain n levels of PARMS. For
7729 example, if PARMS is `template <class T> template <class U>
7730 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
7731 result will be `template <int*, double, class V>'. */
7734 tsubst_template_parms (tree parms, tree args, tsubst_flags_t complain)
7739 /* When substituting into a template, we must set
7740 PROCESSING_TEMPLATE_DECL as the template parameters may be
7741 dependent if they are based on one-another, and the dependency
7742 predicates are short-circuit outside of templates. */
7743 ++processing_template_decl;
7745 for (new_parms = &r;
7746 TMPL_PARMS_DEPTH (parms) > TMPL_ARGS_DEPTH (args);
7747 new_parms = &(TREE_CHAIN (*new_parms)),
7748 parms = TREE_CHAIN (parms))
7751 make_tree_vec (TREE_VEC_LENGTH (TREE_VALUE (parms)));
7754 for (i = 0; i < TREE_VEC_LENGTH (new_vec); ++i)
7760 if (parms == error_mark_node)
7763 tuple = TREE_VEC_ELT (TREE_VALUE (parms), i);
7765 if (tuple == error_mark_node)
7768 default_value = TREE_PURPOSE (tuple);
7769 parm_decl = TREE_VALUE (tuple);
7771 parm_decl = tsubst (parm_decl, args, complain, NULL_TREE);
7772 if (TREE_CODE (parm_decl) == PARM_DECL
7773 && invalid_nontype_parm_type_p (TREE_TYPE (parm_decl), complain))
7774 parm_decl = error_mark_node;
7775 default_value = tsubst_template_arg (default_value, args,
7776 complain, NULL_TREE);
7778 tuple = build_tree_list (default_value, parm_decl);
7779 TREE_VEC_ELT (new_vec, i) = tuple;
7783 tree_cons (size_int (TMPL_PARMS_DEPTH (parms)
7784 - TMPL_ARGS_DEPTH (args)),
7785 new_vec, NULL_TREE);
7788 --processing_template_decl;
7793 /* Substitute the ARGS into the indicated aggregate (or enumeration)
7794 type T. If T is not an aggregate or enumeration type, it is
7795 handled as if by tsubst. IN_DECL is as for tsubst. If
7796 ENTERING_SCOPE is nonzero, T is the context for a template which
7797 we are presently tsubst'ing. Return the substituted value. */
7800 tsubst_aggr_type (tree t,
7802 tsubst_flags_t complain,
7809 switch (TREE_CODE (t))
7812 if (TYPE_PTRMEMFUNC_P (t))
7813 return tsubst (TYPE_PTRMEMFUNC_FN_TYPE (t), args, complain, in_decl);
7815 /* Else fall through. */
7818 if (TYPE_TEMPLATE_INFO (t) && uses_template_parms (t))
7823 bool saved_skip_evaluation;
7825 /* In "sizeof(X<I>)" we need to evaluate "I". */
7826 saved_skip_evaluation = skip_evaluation;
7827 skip_evaluation = false;
7829 /* First, determine the context for the type we are looking
7831 context = TYPE_CONTEXT (t);
7834 context = tsubst_aggr_type (context, args, complain,
7835 in_decl, /*entering_scope=*/1);
7836 /* If context is a nested class inside a class template,
7837 it may still need to be instantiated (c++/33959). */
7838 if (TYPE_P (context))
7839 context = complete_type (context);
7842 /* Then, figure out what arguments are appropriate for the
7843 type we are trying to find. For example, given:
7845 template <class T> struct S;
7846 template <class T, class U> void f(T, U) { S<U> su; }
7848 and supposing that we are instantiating f<int, double>,
7849 then our ARGS will be {int, double}, but, when looking up
7850 S we only want {double}. */
7851 argvec = tsubst_template_args (TYPE_TI_ARGS (t), args,
7853 if (argvec == error_mark_node)
7854 r = error_mark_node;
7857 r = lookup_template_class (t, argvec, in_decl, context,
7858 entering_scope, complain);
7859 r = cp_build_qualified_type_real (r, TYPE_QUALS (t), complain);
7862 skip_evaluation = saved_skip_evaluation;
7867 /* This is not a template type, so there's nothing to do. */
7871 return tsubst (t, args, complain, in_decl);
7875 /* Substitute into the default argument ARG (a default argument for
7876 FN), which has the indicated TYPE. */
7879 tsubst_default_argument (tree fn, tree type, tree arg)
7881 tree saved_class_ptr = NULL_TREE;
7882 tree saved_class_ref = NULL_TREE;
7884 /* This default argument came from a template. Instantiate the
7885 default argument here, not in tsubst. In the case of
7894 we must be careful to do name lookup in the scope of S<T>,
7895 rather than in the current class. */
7896 push_access_scope (fn);
7897 /* The "this" pointer is not valid in a default argument. */
7900 saved_class_ptr = current_class_ptr;
7901 cp_function_chain->x_current_class_ptr = NULL_TREE;
7902 saved_class_ref = current_class_ref;
7903 cp_function_chain->x_current_class_ref = NULL_TREE;
7906 push_deferring_access_checks(dk_no_deferred);
7907 /* The default argument expression may cause implicitly defined
7908 member functions to be synthesized, which will result in garbage
7909 collection. We must treat this situation as if we were within
7910 the body of function so as to avoid collecting live data on the
7913 arg = tsubst_expr (arg, DECL_TI_ARGS (fn),
7914 tf_warning_or_error, NULL_TREE,
7915 /*integral_constant_expression_p=*/false);
7917 pop_deferring_access_checks();
7919 /* Restore the "this" pointer. */
7922 cp_function_chain->x_current_class_ptr = saved_class_ptr;
7923 cp_function_chain->x_current_class_ref = saved_class_ref;
7926 pop_access_scope (fn);
7928 /* Make sure the default argument is reasonable. */
7929 arg = check_default_argument (type, arg);
7934 /* Substitute into all the default arguments for FN. */
7937 tsubst_default_arguments (tree fn)
7942 tmpl_args = DECL_TI_ARGS (fn);
7944 /* If this function is not yet instantiated, we certainly don't need
7945 its default arguments. */
7946 if (uses_template_parms (tmpl_args))
7949 for (arg = TYPE_ARG_TYPES (TREE_TYPE (fn));
7951 arg = TREE_CHAIN (arg))
7952 if (TREE_PURPOSE (arg))
7953 TREE_PURPOSE (arg) = tsubst_default_argument (fn,
7955 TREE_PURPOSE (arg));
7958 /* Substitute the ARGS into the T, which is a _DECL. Return the
7959 result of the substitution. Issue error and warning messages under
7960 control of COMPLAIN. */
7963 tsubst_decl (tree t, tree args, tsubst_flags_t complain)
7965 location_t saved_loc;
7969 /* Set the filename and linenumber to improve error-reporting. */
7970 saved_loc = input_location;
7971 input_location = DECL_SOURCE_LOCATION (t);
7973 switch (TREE_CODE (t))
7977 /* We can get here when processing a member function template,
7978 member class template, and template template parameter of
7979 a template class. */
7980 tree decl = DECL_TEMPLATE_RESULT (t);
7985 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
7987 /* Template template parameter is treated here. */
7988 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
7989 if (new_type == error_mark_node)
7990 return error_mark_node;
7993 TREE_CHAIN (r) = NULL_TREE;
7994 TREE_TYPE (r) = new_type;
7995 DECL_TEMPLATE_RESULT (r)
7996 = build_decl (TYPE_DECL, DECL_NAME (decl), new_type);
7997 DECL_TEMPLATE_PARMS (r)
7998 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
8000 TYPE_NAME (new_type) = r;
8004 /* We might already have an instance of this template.
8005 The ARGS are for the surrounding class type, so the
8006 full args contain the tsubst'd args for the context,
8007 plus the innermost args from the template decl. */
8008 tmpl_args = DECL_CLASS_TEMPLATE_P (t)
8009 ? CLASSTYPE_TI_ARGS (TREE_TYPE (t))
8010 : DECL_TI_ARGS (DECL_TEMPLATE_RESULT (t));
8011 /* Because this is a template, the arguments will still be
8012 dependent, even after substitution. If
8013 PROCESSING_TEMPLATE_DECL is not set, the dependency
8014 predicates will short-circuit. */
8015 ++processing_template_decl;
8016 full_args = tsubst_template_args (tmpl_args, args,
8018 --processing_template_decl;
8019 if (full_args == error_mark_node)
8020 return error_mark_node;
8022 /* tsubst_template_args doesn't copy the vector if
8023 nothing changed. But, *something* should have
8025 gcc_assert (full_args != tmpl_args);
8027 spec = retrieve_specialization (t, full_args,
8028 /*class_specializations_p=*/true);
8029 if (spec != NULL_TREE)
8035 /* Make a new template decl. It will be similar to the
8036 original, but will record the current template arguments.
8037 We also create a new function declaration, which is just
8038 like the old one, but points to this new template, rather
8039 than the old one. */
8041 gcc_assert (DECL_LANG_SPECIFIC (r) != 0);
8042 TREE_CHAIN (r) = NULL_TREE;
8044 DECL_TEMPLATE_INFO (r) = build_tree_list (t, args);
8046 if (TREE_CODE (decl) == TYPE_DECL)
8049 ++processing_template_decl;
8050 new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8051 --processing_template_decl;
8052 if (new_type == error_mark_node)
8053 return error_mark_node;
8055 TREE_TYPE (r) = new_type;
8056 CLASSTYPE_TI_TEMPLATE (new_type) = r;
8057 DECL_TEMPLATE_RESULT (r) = TYPE_MAIN_DECL (new_type);
8058 DECL_TI_ARGS (r) = CLASSTYPE_TI_ARGS (new_type);
8059 DECL_CONTEXT (r) = TYPE_CONTEXT (new_type);
8064 ++processing_template_decl;
8065 new_decl = tsubst (decl, args, complain, in_decl);
8066 --processing_template_decl;
8067 if (new_decl == error_mark_node)
8068 return error_mark_node;
8070 DECL_TEMPLATE_RESULT (r) = new_decl;
8071 DECL_TI_TEMPLATE (new_decl) = r;
8072 TREE_TYPE (r) = TREE_TYPE (new_decl);
8073 DECL_TI_ARGS (r) = DECL_TI_ARGS (new_decl);
8074 DECL_CONTEXT (r) = DECL_CONTEXT (new_decl);
8077 SET_DECL_IMPLICIT_INSTANTIATION (r);
8078 DECL_TEMPLATE_INSTANTIATIONS (r) = NULL_TREE;
8079 DECL_TEMPLATE_SPECIALIZATIONS (r) = NULL_TREE;
8081 /* The template parameters for this new template are all the
8082 template parameters for the old template, except the
8083 outermost level of parameters. */
8084 DECL_TEMPLATE_PARMS (r)
8085 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
8088 if (PRIMARY_TEMPLATE_P (t))
8089 DECL_PRIMARY_TEMPLATE (r) = r;
8091 if (TREE_CODE (decl) != TYPE_DECL)
8092 /* Record this non-type partial instantiation. */
8093 register_specialization (r, t,
8094 DECL_TI_ARGS (DECL_TEMPLATE_RESULT (r)),
8102 tree argvec = NULL_TREE;
8110 /* Nobody should be tsubst'ing into non-template functions. */
8111 gcc_assert (DECL_TEMPLATE_INFO (t) != NULL_TREE);
8113 if (TREE_CODE (DECL_TI_TEMPLATE (t)) == TEMPLATE_DECL)
8118 /* If T is not dependent, just return it. We have to
8119 increment PROCESSING_TEMPLATE_DECL because
8120 value_dependent_expression_p assumes that nothing is
8121 dependent when PROCESSING_TEMPLATE_DECL is zero. */
8122 ++processing_template_decl;
8123 dependent_p = value_dependent_expression_p (t);
8124 --processing_template_decl;
8128 /* Calculate the most general template of which R is a
8129 specialization, and the complete set of arguments used to
8131 gen_tmpl = most_general_template (DECL_TI_TEMPLATE (t));
8132 argvec = tsubst_template_args (DECL_TI_ARGS
8133 (DECL_TEMPLATE_RESULT (gen_tmpl)),
8134 args, complain, in_decl);
8136 /* Check to see if we already have this specialization. */
8137 spec = retrieve_specialization (gen_tmpl, argvec,
8138 /*class_specializations_p=*/false);
8146 /* We can see more levels of arguments than parameters if
8147 there was a specialization of a member template, like
8150 template <class T> struct S { template <class U> void f(); }
8151 template <> template <class U> void S<int>::f(U);
8153 Here, we'll be substituting into the specialization,
8154 because that's where we can find the code we actually
8155 want to generate, but we'll have enough arguments for
8156 the most general template.
8158 We also deal with the peculiar case:
8160 template <class T> struct S {
8161 template <class U> friend void f();
8163 template <class U> void f() {}
8165 template void f<double>();
8167 Here, the ARGS for the instantiation of will be {int,
8168 double}. But, we only need as many ARGS as there are
8169 levels of template parameters in CODE_PATTERN. We are
8170 careful not to get fooled into reducing the ARGS in
8173 template <class T> struct S { template <class U> void f(U); }
8174 template <class T> template <> void S<T>::f(int) {}
8176 which we can spot because the pattern will be a
8177 specialization in this case. */
8178 args_depth = TMPL_ARGS_DEPTH (args);
8180 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (t)));
8181 if (args_depth > parms_depth
8182 && !DECL_TEMPLATE_SPECIALIZATION (t))
8183 args = get_innermost_template_args (args, parms_depth);
8187 /* This special case arises when we have something like this:
8189 template <class T> struct S {
8190 friend void f<int>(int, double);
8193 Here, the DECL_TI_TEMPLATE for the friend declaration
8194 will be an IDENTIFIER_NODE. We are being called from
8195 tsubst_friend_function, and we want only to create a
8196 new decl (R) with appropriate types so that we can call
8197 determine_specialization. */
8198 gen_tmpl = NULL_TREE;
8201 if (DECL_CLASS_SCOPE_P (t))
8203 if (DECL_NAME (t) == constructor_name (DECL_CONTEXT (t)))
8207 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args,
8208 complain, t, /*entering_scope=*/1);
8213 ctx = DECL_CONTEXT (t);
8215 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8216 if (type == error_mark_node)
8217 return error_mark_node;
8219 /* We do NOT check for matching decls pushed separately at this
8220 point, as they may not represent instantiations of this
8221 template, and in any case are considered separate under the
8224 DECL_USE_TEMPLATE (r) = 0;
8225 TREE_TYPE (r) = type;
8226 /* Clear out the mangled name and RTL for the instantiation. */
8227 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
8228 SET_DECL_RTL (r, NULL_RTX);
8229 /* Leave DECL_INITIAL set on deleted instantiations. */
8230 if (!DECL_DELETED_FN (r))
8231 DECL_INITIAL (r) = NULL_TREE;
8232 DECL_CONTEXT (r) = ctx;
8234 if (member && DECL_CONV_FN_P (r))
8235 /* Type-conversion operator. Reconstruct the name, in
8236 case it's the name of one of the template's parameters. */
8237 DECL_NAME (r) = mangle_conv_op_name_for_type (TREE_TYPE (type));
8239 DECL_ARGUMENTS (r) = tsubst (DECL_ARGUMENTS (t), args,
8241 DECL_RESULT (r) = NULL_TREE;
8243 TREE_STATIC (r) = 0;
8244 TREE_PUBLIC (r) = TREE_PUBLIC (t);
8245 DECL_EXTERNAL (r) = 1;
8246 /* If this is an instantiation of a function with internal
8247 linkage, we already know what object file linkage will be
8248 assigned to the instantiation. */
8249 DECL_INTERFACE_KNOWN (r) = !TREE_PUBLIC (r);
8250 DECL_DEFER_OUTPUT (r) = 0;
8251 TREE_CHAIN (r) = NULL_TREE;
8252 DECL_PENDING_INLINE_INFO (r) = 0;
8253 DECL_PENDING_INLINE_P (r) = 0;
8254 DECL_SAVED_TREE (r) = NULL_TREE;
8255 DECL_STRUCT_FUNCTION (r) = NULL;
8257 if (DECL_CLONED_FUNCTION (r))
8259 DECL_CLONED_FUNCTION (r) = tsubst (DECL_CLONED_FUNCTION (t),
8261 TREE_CHAIN (r) = TREE_CHAIN (DECL_CLONED_FUNCTION (r));
8262 TREE_CHAIN (DECL_CLONED_FUNCTION (r)) = r;
8265 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
8266 this in the special friend case mentioned above where
8267 GEN_TMPL is NULL. */
8270 DECL_TEMPLATE_INFO (r)
8271 = tree_cons (gen_tmpl, argvec, NULL_TREE);
8272 SET_DECL_IMPLICIT_INSTANTIATION (r);
8273 register_specialization (r, gen_tmpl, argvec, false);
8275 /* We're not supposed to instantiate default arguments
8276 until they are called, for a template. But, for a
8279 template <class T> void f ()
8280 { extern void g(int i = T()); }
8282 we should do the substitution when the template is
8283 instantiated. We handle the member function case in
8284 instantiate_class_template since the default arguments
8285 might refer to other members of the class. */
8287 && !PRIMARY_TEMPLATE_P (gen_tmpl)
8288 && !uses_template_parms (argvec))
8289 tsubst_default_arguments (r);
8292 DECL_TEMPLATE_INFO (r) = NULL_TREE;
8294 /* Copy the list of befriending classes. */
8295 for (friends = &DECL_BEFRIENDING_CLASSES (r);
8297 friends = &TREE_CHAIN (*friends))
8299 *friends = copy_node (*friends);
8300 TREE_VALUE (*friends) = tsubst (TREE_VALUE (*friends),
8305 if (DECL_CONSTRUCTOR_P (r) || DECL_DESTRUCTOR_P (r))
8307 maybe_retrofit_in_chrg (r);
8308 if (DECL_CONSTRUCTOR_P (r))
8309 grok_ctor_properties (ctx, r);
8310 /* If this is an instantiation of a member template, clone it.
8311 If it isn't, that'll be handled by
8312 clone_constructors_and_destructors. */
8313 if (PRIMARY_TEMPLATE_P (gen_tmpl))
8314 clone_function_decl (r, /*update_method_vec_p=*/0);
8316 else if (IDENTIFIER_OPNAME_P (DECL_NAME (r))
8317 && !grok_op_properties (r, (complain & tf_error) != 0))
8318 return error_mark_node;
8320 if (DECL_FRIEND_P (t) && DECL_FRIEND_CONTEXT (t))
8321 SET_DECL_FRIEND_CONTEXT (r,
8322 tsubst (DECL_FRIEND_CONTEXT (t),
8323 args, complain, in_decl));
8325 /* Possibly limit visibility based on template args. */
8326 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
8327 if (DECL_VISIBILITY_SPECIFIED (t))
8329 DECL_VISIBILITY_SPECIFIED (r) = 0;
8331 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
8333 determine_visibility (r);
8335 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
8336 args, complain, in_decl);
8342 tree type = NULL_TREE;
8344 tree expanded_types = NULL_TREE;
8345 tree prev_r = NULL_TREE;
8346 tree first_r = NULL_TREE;
8348 if (FUNCTION_PARAMETER_PACK_P (t))
8350 /* If there is a local specialization that isn't a
8351 parameter pack, it means that we're doing a "simple"
8352 substitution from inside tsubst_pack_expansion. Just
8353 return the local specialization (which will be a single
8355 tree spec = retrieve_local_specialization (t);
8357 && TREE_CODE (spec) == PARM_DECL
8358 && TREE_CODE (TREE_TYPE (spec)) != TYPE_PACK_EXPANSION)
8361 /* Expand the TYPE_PACK_EXPANSION that provides the types for
8362 the parameters in this function parameter pack. */
8363 expanded_types = tsubst_pack_expansion (TREE_TYPE (t), args,
8365 if (TREE_CODE (expanded_types) == TREE_VEC)
8367 len = TREE_VEC_LENGTH (expanded_types);
8369 /* Zero-length parameter packs are boring. Just substitute
8372 return tsubst (TREE_CHAIN (t), args, complain,
8377 /* All we did was update the type. Make a note of that. */
8378 type = expanded_types;
8379 expanded_types = NULL_TREE;
8383 /* Loop through all of the parameter's we'll build. When T is
8384 a function parameter pack, LEN is the number of expanded
8385 types in EXPANDED_TYPES; otherwise, LEN is 1. */
8387 for (i = 0; i < len; ++i)
8391 if (DECL_TEMPLATE_PARM_P (t))
8392 SET_DECL_TEMPLATE_PARM_P (r);
8395 /* We're on the Ith parameter of the function parameter
8398 /* Get the Ith type. */
8399 type = TREE_VEC_ELT (expanded_types, i);
8402 /* Rename the parameter to include the index. */
8404 make_ith_pack_parameter_name (DECL_NAME (r), i);
8407 /* We're dealing with a normal parameter. */
8408 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8410 type = type_decays_to (type);
8411 TREE_TYPE (r) = type;
8412 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
8414 if (DECL_INITIAL (r))
8416 if (TREE_CODE (DECL_INITIAL (r)) != TEMPLATE_PARM_INDEX)
8417 DECL_INITIAL (r) = TREE_TYPE (r);
8419 DECL_INITIAL (r) = tsubst (DECL_INITIAL (r), args,
8423 DECL_CONTEXT (r) = NULL_TREE;
8425 if (!DECL_TEMPLATE_PARM_P (r))
8426 DECL_ARG_TYPE (r) = type_passed_as (type);
8428 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
8429 args, complain, in_decl);
8431 /* Keep track of the first new parameter we
8432 generate. That's what will be returned to the
8437 /* Build a proper chain of parameters when substituting
8438 into a function parameter pack. */
8440 TREE_CHAIN (prev_r) = r;
8444 TREE_CHAIN (r) = tsubst (TREE_CHAIN (t), args,
8445 complain, TREE_CHAIN (t));
8447 /* FIRST_R contains the start of the chain we've built. */
8457 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8458 if (type == error_mark_node)
8459 return error_mark_node;
8460 TREE_TYPE (r) = type;
8461 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
8463 /* DECL_INITIAL gives the number of bits in a bit-field. */
8465 = tsubst_expr (DECL_INITIAL (t), args,
8467 /*integral_constant_expression_p=*/true);
8468 /* We don't have to set DECL_CONTEXT here; it is set by
8469 finish_member_declaration. */
8470 TREE_CHAIN (r) = NULL_TREE;
8471 if (VOID_TYPE_P (type))
8472 error ("instantiation of %q+D as type %qT", r, type);
8474 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
8475 args, complain, in_decl);
8480 /* We reach here only for member using decls. */
8481 if (DECL_DEPENDENT_P (t))
8483 r = do_class_using_decl
8484 (tsubst_copy (USING_DECL_SCOPE (t), args, complain, in_decl),
8485 tsubst_copy (DECL_NAME (t), args, complain, in_decl));
8487 r = error_mark_node;
8492 TREE_CHAIN (r) = NULL_TREE;
8499 tree argvec = NULL_TREE;
8500 tree gen_tmpl = NULL_TREE;
8502 tree tmpl = NULL_TREE;
8504 tree type = NULL_TREE;
8507 if (TREE_CODE (t) == TYPE_DECL
8508 && t == TYPE_MAIN_DECL (TREE_TYPE (t)))
8510 /* If this is the canonical decl, we don't have to
8511 mess with instantiations, and often we can't (for
8512 typename, template type parms and such). Note that
8513 TYPE_NAME is not correct for the above test if
8514 we've copied the type for a typedef. */
8515 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8516 if (type == error_mark_node)
8517 return error_mark_node;
8518 r = TYPE_NAME (type);
8522 /* Check to see if we already have the specialization we
8525 if (DECL_CLASS_SCOPE_P (t) || DECL_NAMESPACE_SCOPE_P (t))
8527 /* T is a static data member or namespace-scope entity.
8528 We have to substitute into namespace-scope variables
8529 (even though such entities are never templates) because
8532 template <class T> void f() { extern T t; }
8534 where the entity referenced is not known until
8535 instantiation time. */
8537 ctx = DECL_CONTEXT (t);
8538 if (DECL_CLASS_SCOPE_P (t))
8540 ctx = tsubst_aggr_type (ctx, args,
8542 in_decl, /*entering_scope=*/1);
8543 /* If CTX is unchanged, then T is in fact the
8544 specialization we want. That situation occurs when
8545 referencing a static data member within in its own
8546 class. We can use pointer equality, rather than
8547 same_type_p, because DECL_CONTEXT is always
8549 if (ctx == DECL_CONTEXT (t))
8555 tmpl = DECL_TI_TEMPLATE (t);
8556 gen_tmpl = most_general_template (tmpl);
8557 argvec = tsubst (DECL_TI_ARGS (t), args, complain, in_decl);
8558 spec = (retrieve_specialization
8560 /*class_specializations_p=*/false));
8565 /* A local variable. */
8567 /* Subsequent calls to pushdecl will fill this in. */
8569 spec = retrieve_local_specialization (t);
8571 /* If we already have the specialization we need, there is
8572 nothing more to do. */
8579 /* Create a new node for the specialization we need. */
8581 if (type == NULL_TREE)
8582 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8583 if (TREE_CODE (r) == VAR_DECL)
8585 /* Even if the original location is out of scope, the
8586 newly substituted one is not. */
8587 DECL_DEAD_FOR_LOCAL (r) = 0;
8588 DECL_INITIALIZED_P (r) = 0;
8589 DECL_TEMPLATE_INSTANTIATED (r) = 0;
8590 if (type == error_mark_node)
8591 return error_mark_node;
8592 if (TREE_CODE (type) == FUNCTION_TYPE)
8594 /* It may seem that this case cannot occur, since:
8599 declares a function, not a variable. However:
8602 template <typename T> void g() { T t; }
8603 template void g<f>();
8605 is an attempt to declare a variable with function
8607 error ("variable %qD has function type",
8608 /* R is not yet sufficiently initialized, so we
8609 just use its name. */
8611 return error_mark_node;
8613 type = complete_type (type);
8614 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r)
8615 = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (t);
8616 type = check_var_type (DECL_NAME (r), type);
8618 if (DECL_HAS_VALUE_EXPR_P (t))
8620 tree ve = DECL_VALUE_EXPR (t);
8621 ve = tsubst_expr (ve, args, complain, in_decl,
8622 /*constant_expression_p=*/false);
8623 SET_DECL_VALUE_EXPR (r, ve);
8626 else if (DECL_SELF_REFERENCE_P (t))
8627 SET_DECL_SELF_REFERENCE_P (r);
8628 TREE_TYPE (r) = type;
8629 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
8630 DECL_CONTEXT (r) = ctx;
8631 /* Clear out the mangled name and RTL for the instantiation. */
8632 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
8633 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
8634 SET_DECL_RTL (r, NULL_RTX);
8635 /* The initializer must not be expanded until it is required;
8637 DECL_INITIAL (r) = NULL_TREE;
8638 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
8639 SET_DECL_RTL (r, NULL_RTX);
8640 DECL_SIZE (r) = DECL_SIZE_UNIT (r) = 0;
8641 if (TREE_CODE (r) == VAR_DECL)
8643 /* Possibly limit visibility based on template args. */
8644 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
8645 if (DECL_VISIBILITY_SPECIFIED (t))
8647 DECL_VISIBILITY_SPECIFIED (r) = 0;
8649 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
8651 determine_visibility (r);
8653 /* Preserve a typedef that names a type. */
8654 else if (TREE_CODE (r) == TYPE_DECL
8655 && DECL_ORIGINAL_TYPE (t)
8656 && type != error_mark_node)
8658 DECL_ORIGINAL_TYPE (r) = tsubst (DECL_ORIGINAL_TYPE (t),
8659 args, complain, in_decl);
8660 TREE_TYPE (r) = type = build_variant_type_copy (type);
8661 TYPE_NAME (type) = r;
8666 /* A static data member declaration is always marked
8667 external when it is declared in-class, even if an
8668 initializer is present. We mimic the non-template
8670 DECL_EXTERNAL (r) = 1;
8672 register_specialization (r, gen_tmpl, argvec, false);
8673 DECL_TEMPLATE_INFO (r) = tree_cons (tmpl, argvec, NULL_TREE);
8674 SET_DECL_IMPLICIT_INSTANTIATION (r);
8677 register_local_specialization (r, t);
8679 TREE_CHAIN (r) = NULL_TREE;
8681 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r),
8682 (int) ATTR_FLAG_TYPE_IN_PLACE,
8683 args, complain, in_decl);
8692 /* Restore the file and line information. */
8693 input_location = saved_loc;
8698 /* Substitute into the ARG_TYPES of a function type. */
8701 tsubst_arg_types (tree arg_types,
8703 tsubst_flags_t complain,
8706 tree remaining_arg_types;
8707 tree type = NULL_TREE;
8709 tree expanded_args = NULL_TREE;
8712 if (!arg_types || arg_types == void_list_node)
8715 remaining_arg_types = tsubst_arg_types (TREE_CHAIN (arg_types),
8716 args, complain, in_decl);
8717 if (remaining_arg_types == error_mark_node)
8718 return error_mark_node;
8720 if (PACK_EXPANSION_P (TREE_VALUE (arg_types)))
8722 /* For a pack expansion, perform substitution on the
8723 entire expression. Later on, we'll handle the arguments
8725 expanded_args = tsubst_pack_expansion (TREE_VALUE (arg_types),
8726 args, complain, in_decl);
8728 if (TREE_CODE (expanded_args) == TREE_VEC)
8729 /* So that we'll spin through the parameters, one by one. */
8730 i = TREE_VEC_LENGTH (expanded_args);
8733 /* We only partially substituted into the parameter
8734 pack. Our type is TYPE_PACK_EXPANSION. */
8735 type = expanded_args;
8736 expanded_args = NULL_TREE;
8744 type = TREE_VEC_ELT (expanded_args, i);
8746 type = tsubst (TREE_VALUE (arg_types), args, complain, in_decl);
8748 if (type == error_mark_node)
8749 return error_mark_node;
8750 if (VOID_TYPE_P (type))
8752 if (complain & tf_error)
8754 error ("invalid parameter type %qT", type);
8756 error ("in declaration %q+D", in_decl);
8758 return error_mark_node;
8761 /* Do array-to-pointer, function-to-pointer conversion, and ignore
8762 top-level qualifiers as required. */
8763 type = TYPE_MAIN_VARIANT (type_decays_to (type));
8765 /* We do not substitute into default arguments here. The standard
8766 mandates that they be instantiated only when needed, which is
8767 done in build_over_call. */
8768 default_arg = TREE_PURPOSE (arg_types);
8770 if (default_arg && TREE_CODE (default_arg) == DEFAULT_ARG)
8772 /* We've instantiated a template before its default arguments
8773 have been parsed. This can happen for a nested template
8774 class, and is not an error unless we require the default
8775 argument in a call of this function. */
8776 remaining_arg_types =
8777 tree_cons (default_arg, type, remaining_arg_types);
8778 VEC_safe_push (tree, gc, DEFARG_INSTANTIATIONS (default_arg),
8779 remaining_arg_types);
8782 remaining_arg_types =
8783 hash_tree_cons (default_arg, type, remaining_arg_types);
8786 return remaining_arg_types;
8789 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
8790 *not* handle the exception-specification for FNTYPE, because the
8791 initial substitution of explicitly provided template parameters
8792 during argument deduction forbids substitution into the
8793 exception-specification:
8797 All references in the function type of the function template to the
8798 corresponding template parameters are replaced by the specified tem-
8799 plate argument values. If a substitution in a template parameter or
8800 in the function type of the function template results in an invalid
8801 type, type deduction fails. [Note: The equivalent substitution in
8802 exception specifications is done only when the function is instanti-
8803 ated, at which point a program is ill-formed if the substitution
8804 results in an invalid type.] */
8807 tsubst_function_type (tree t,
8809 tsubst_flags_t complain,
8816 /* The TYPE_CONTEXT is not used for function/method types. */
8817 gcc_assert (TYPE_CONTEXT (t) == NULL_TREE);
8819 /* Substitute the return type. */
8820 return_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8821 if (return_type == error_mark_node)
8822 return error_mark_node;
8823 /* The standard does not presently indicate that creation of a
8824 function type with an invalid return type is a deduction failure.
8825 However, that is clearly analogous to creating an array of "void"
8826 or a reference to a reference. This is core issue #486. */
8827 if (TREE_CODE (return_type) == ARRAY_TYPE
8828 || TREE_CODE (return_type) == FUNCTION_TYPE)
8830 if (complain & tf_error)
8832 if (TREE_CODE (return_type) == ARRAY_TYPE)
8833 error ("function returning an array");
8835 error ("function returning a function");
8837 return error_mark_node;
8840 /* Substitute the argument types. */
8841 arg_types = tsubst_arg_types (TYPE_ARG_TYPES (t), args,
8843 if (arg_types == error_mark_node)
8844 return error_mark_node;
8846 /* Construct a new type node and return it. */
8847 if (TREE_CODE (t) == FUNCTION_TYPE)
8848 fntype = build_function_type (return_type, arg_types);
8851 tree r = TREE_TYPE (TREE_VALUE (arg_types));
8852 if (! MAYBE_CLASS_TYPE_P (r))
8856 Type deduction may fail for any of the following
8859 -- Attempting to create "pointer to member of T" when T
8860 is not a class type. */
8861 if (complain & tf_error)
8862 error ("creating pointer to member function of non-class type %qT",
8864 return error_mark_node;
8867 fntype = build_method_type_directly (r, return_type,
8868 TREE_CHAIN (arg_types));
8870 fntype = cp_build_qualified_type_real (fntype, TYPE_QUALS (t), complain);
8871 fntype = cp_build_type_attribute_variant (fntype, TYPE_ATTRIBUTES (t));
8876 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
8877 ARGS into that specification, and return the substituted
8878 specification. If there is no specification, return NULL_TREE. */
8881 tsubst_exception_specification (tree fntype,
8883 tsubst_flags_t complain,
8889 specs = TYPE_RAISES_EXCEPTIONS (fntype);
8890 new_specs = NULL_TREE;
8893 if (! TREE_VALUE (specs))
8900 tree expanded_specs = NULL_TREE;
8902 if (PACK_EXPANSION_P (TREE_VALUE (specs)))
8904 /* Expand the pack expansion type. */
8905 expanded_specs = tsubst_pack_expansion (TREE_VALUE (specs),
8909 if (expanded_specs == error_mark_node)
8910 return error_mark_node;
8911 else if (TREE_CODE (expanded_specs) == TREE_VEC)
8912 len = TREE_VEC_LENGTH (expanded_specs);
8915 /* We're substituting into a member template, so
8916 we got a TYPE_PACK_EXPANSION back. Add that
8917 expansion and move on. */
8918 gcc_assert (TREE_CODE (expanded_specs)
8919 == TYPE_PACK_EXPANSION);
8920 new_specs = add_exception_specifier (new_specs,
8923 specs = TREE_CHAIN (specs);
8928 for (i = 0; i < len; ++i)
8931 spec = TREE_VEC_ELT (expanded_specs, i);
8933 spec = tsubst (TREE_VALUE (specs), args, complain, in_decl);
8934 if (spec == error_mark_node)
8936 new_specs = add_exception_specifier (new_specs, spec,
8940 specs = TREE_CHAIN (specs);
8946 /* Take the tree structure T and replace template parameters used
8947 therein with the argument vector ARGS. IN_DECL is an associated
8948 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
8949 Issue error and warning messages under control of COMPLAIN. Note
8950 that we must be relatively non-tolerant of extensions here, in
8951 order to preserve conformance; if we allow substitutions that
8952 should not be allowed, we may allow argument deductions that should
8953 not succeed, and therefore report ambiguous overload situations
8954 where there are none. In theory, we could allow the substitution,
8955 but indicate that it should have failed, and allow our caller to
8956 make sure that the right thing happens, but we don't try to do this
8959 This function is used for dealing with types, decls and the like;
8960 for expressions, use tsubst_expr or tsubst_copy. */
8963 tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl)
8967 if (t == NULL_TREE || t == error_mark_node
8968 || t == integer_type_node
8969 || t == void_type_node
8970 || t == char_type_node
8971 || t == unknown_type_node
8972 || TREE_CODE (t) == NAMESPACE_DECL)
8976 return tsubst_decl (t, args, complain);
8978 if (args == NULL_TREE)
8981 if (TREE_CODE (t) == IDENTIFIER_NODE)
8982 type = IDENTIFIER_TYPE_VALUE (t);
8984 type = TREE_TYPE (t);
8986 gcc_assert (type != unknown_type_node);
8988 /* Reuse typedefs. We need to do this to handle dependent attributes,
8989 such as attribute aligned. */
8992 && TYPE_NAME (t) != TYPE_MAIN_DECL (t))
8994 tree decl = TYPE_NAME (t);
8996 if (DECL_CLASS_SCOPE_P (decl)
8997 && CLASSTYPE_TEMPLATE_INFO (DECL_CONTEXT (decl))
8998 && uses_template_parms (DECL_CONTEXT (decl)))
9000 tree tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
9001 tree gen_args = tsubst (DECL_TI_ARGS (decl), args, complain, in_decl);
9002 r = retrieve_specialization (tmpl, gen_args, false);
9004 else if (DECL_FUNCTION_SCOPE_P (decl)
9005 && DECL_TEMPLATE_INFO (DECL_CONTEXT (decl))
9006 && uses_template_parms (DECL_TI_ARGS (DECL_CONTEXT (decl))))
9007 r = retrieve_local_specialization (decl);
9009 /* The typedef is from a non-template context. */
9015 r = cp_build_qualified_type_real
9016 (r, cp_type_quals (t) | cp_type_quals (r),
9017 complain | tf_ignore_bad_quals);
9020 /* Else we must be instantiating the typedef, so fall through. */
9024 && TREE_CODE (t) != TYPENAME_TYPE
9025 && TREE_CODE (t) != IDENTIFIER_NODE
9026 && TREE_CODE (t) != FUNCTION_TYPE
9027 && TREE_CODE (t) != METHOD_TYPE)
9028 type = tsubst (type, args, complain, in_decl);
9029 if (type == error_mark_node)
9030 return error_mark_node;
9032 switch (TREE_CODE (t))
9037 return tsubst_aggr_type (t, args, complain, in_decl,
9038 /*entering_scope=*/0);
9041 case IDENTIFIER_NODE:
9053 if (t == integer_type_node)
9056 if (TREE_CODE (TYPE_MIN_VALUE (t)) == INTEGER_CST
9057 && TREE_CODE (TYPE_MAX_VALUE (t)) == INTEGER_CST)
9061 tree max, omax = TREE_OPERAND (TYPE_MAX_VALUE (t), 0);
9063 max = tsubst_expr (omax, args, complain, in_decl,
9064 /*integral_constant_expression_p=*/false);
9065 max = fold_decl_constant_value (max);
9067 if (TREE_CODE (max) != INTEGER_CST
9068 && !at_function_scope_p ()
9069 && !value_dependent_expression_p (max))
9071 if (complain & tf_error)
9072 error ("array bound is not an integer constant");
9073 return error_mark_node;
9078 Type deduction may fail for any of the following
9081 Attempting to create an array with a size that is
9082 zero or negative. */
9083 if (integer_zerop (max) && !(complain & tf_error))
9084 /* We must fail if performing argument deduction (as
9085 indicated by the state of complain), so that
9086 another substitution can be found. */
9087 return error_mark_node;
9088 else if (TREE_CODE (max) == INTEGER_CST
9089 && INT_CST_LT (max, integer_zero_node))
9091 if (complain & tf_error)
9092 error ("creating array with negative size (%qE)", max);
9094 return error_mark_node;
9097 return compute_array_index_type (NULL_TREE, max);
9100 case TEMPLATE_TYPE_PARM:
9101 case TEMPLATE_TEMPLATE_PARM:
9102 case BOUND_TEMPLATE_TEMPLATE_PARM:
9103 case TEMPLATE_PARM_INDEX:
9108 tree arg = NULL_TREE;
9112 gcc_assert (TREE_VEC_LENGTH (args) > 0);
9113 template_parm_level_and_index (t, &level, &idx);
9115 levels = TMPL_ARGS_DEPTH (args);
9116 if (level <= levels)
9118 arg = TMPL_ARG (args, level, idx);
9120 if (arg && TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
9121 /* See through ARGUMENT_PACK_SELECT arguments. */
9122 arg = ARGUMENT_PACK_SELECT_ARG (arg);
9125 if (arg == error_mark_node)
9126 return error_mark_node;
9127 else if (arg != NULL_TREE)
9129 if (ARGUMENT_PACK_P (arg))
9130 /* If ARG is an argument pack, we don't actually want to
9131 perform a substitution here, because substitutions
9132 for argument packs are only done
9133 element-by-element. We can get to this point when
9134 substituting the type of a non-type template
9135 parameter pack, when that type actually contains
9136 template parameter packs from an outer template, e.g.,
9138 template<typename... Types> struct A {
9139 template<Types... Values> struct B { };
9143 if (TREE_CODE (t) == TEMPLATE_TYPE_PARM)
9146 gcc_assert (TYPE_P (arg));
9148 /* cv-quals from the template are discarded when
9149 substituting in a function or reference type. */
9150 if (TREE_CODE (arg) == FUNCTION_TYPE
9151 || TREE_CODE (arg) == METHOD_TYPE
9152 || TREE_CODE (arg) == REFERENCE_TYPE)
9153 quals = cp_type_quals (arg);
9155 quals = cp_type_quals (arg) | cp_type_quals (t);
9157 return cp_build_qualified_type_real
9158 (arg, quals, complain | tf_ignore_bad_quals);
9160 else if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
9162 /* We are processing a type constructed from a
9163 template template parameter. */
9164 tree argvec = tsubst (TYPE_TI_ARGS (t),
9165 args, complain, in_decl);
9166 if (argvec == error_mark_node)
9167 return error_mark_node;
9169 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
9170 are resolving nested-types in the signature of a
9171 member function templates. Otherwise ARG is a
9172 TEMPLATE_DECL and is the real template to be
9174 if (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
9175 arg = TYPE_NAME (arg);
9177 r = lookup_template_class (arg,
9180 /*entering_scope=*/0,
9182 return cp_build_qualified_type_real
9183 (r, TYPE_QUALS (t), complain);
9186 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
9191 /* This can happen during the attempted tsubst'ing in
9192 unify. This means that we don't yet have any information
9193 about the template parameter in question. */
9196 /* If we get here, we must have been looking at a parm for a
9197 more deeply nested template. Make a new version of this
9198 template parameter, but with a lower level. */
9199 switch (TREE_CODE (t))
9201 case TEMPLATE_TYPE_PARM:
9202 case TEMPLATE_TEMPLATE_PARM:
9203 case BOUND_TEMPLATE_TEMPLATE_PARM:
9204 if (cp_type_quals (t))
9206 r = tsubst (TYPE_MAIN_VARIANT (t), args, complain, in_decl);
9207 r = cp_build_qualified_type_real
9208 (r, cp_type_quals (t),
9209 complain | (TREE_CODE (t) == TEMPLATE_TYPE_PARM
9210 ? tf_ignore_bad_quals : 0));
9215 TEMPLATE_TYPE_PARM_INDEX (r)
9216 = reduce_template_parm_level (TEMPLATE_TYPE_PARM_INDEX (t),
9217 r, levels, args, complain);
9218 TYPE_STUB_DECL (r) = TYPE_NAME (r) = TEMPLATE_TYPE_DECL (r);
9219 TYPE_MAIN_VARIANT (r) = r;
9220 TYPE_POINTER_TO (r) = NULL_TREE;
9221 TYPE_REFERENCE_TO (r) = NULL_TREE;
9223 if (TREE_CODE (r) == TEMPLATE_TEMPLATE_PARM)
9224 /* We have reduced the level of the template
9225 template parameter, but not the levels of its
9226 template parameters, so canonical_type_parameter
9227 will not be able to find the canonical template
9228 template parameter for this level. Thus, we
9229 require structural equality checking to compare
9230 TEMPLATE_TEMPLATE_PARMs. */
9231 SET_TYPE_STRUCTURAL_EQUALITY (r);
9232 else if (TYPE_STRUCTURAL_EQUALITY_P (t))
9233 SET_TYPE_STRUCTURAL_EQUALITY (r);
9235 TYPE_CANONICAL (r) = canonical_type_parameter (r);
9237 if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
9239 tree argvec = tsubst (TYPE_TI_ARGS (t), args,
9241 if (argvec == error_mark_node)
9242 return error_mark_node;
9244 TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (r)
9245 = tree_cons (TYPE_TI_TEMPLATE (t), argvec, NULL_TREE);
9250 case TEMPLATE_PARM_INDEX:
9251 r = reduce_template_parm_level (t, type, levels, args, complain);
9263 tree purpose, value, chain;
9265 if (t == void_list_node)
9268 purpose = TREE_PURPOSE (t);
9271 purpose = tsubst (purpose, args, complain, in_decl);
9272 if (purpose == error_mark_node)
9273 return error_mark_node;
9275 value = TREE_VALUE (t);
9278 value = tsubst (value, args, complain, in_decl);
9279 if (value == error_mark_node)
9280 return error_mark_node;
9282 chain = TREE_CHAIN (t);
9283 if (chain && chain != void_type_node)
9285 chain = tsubst (chain, args, complain, in_decl);
9286 if (chain == error_mark_node)
9287 return error_mark_node;
9289 if (purpose == TREE_PURPOSE (t)
9290 && value == TREE_VALUE (t)
9291 && chain == TREE_CHAIN (t))
9293 return hash_tree_cons (purpose, value, chain);
9297 /* We should never be tsubsting a binfo. */
9301 /* A vector of template arguments. */
9303 return tsubst_template_args (t, args, complain, in_decl);
9306 case REFERENCE_TYPE:
9308 enum tree_code code;
9310 if (type == TREE_TYPE (t) && TREE_CODE (type) != METHOD_TYPE)
9313 code = TREE_CODE (t);
9318 Type deduction may fail for any of the following
9321 -- Attempting to create a pointer to reference type.
9322 -- Attempting to create a reference to a reference type or
9323 a reference to void.
9325 Core issue 106 says that creating a reference to a reference
9326 during instantiation is no longer a cause for failure. We
9327 only enforce this check in strict C++98 mode. */
9328 if ((TREE_CODE (type) == REFERENCE_TYPE
9329 && (((cxx_dialect == cxx98) && flag_iso) || code != REFERENCE_TYPE))
9330 || (code == REFERENCE_TYPE && TREE_CODE (type) == VOID_TYPE))
9332 static location_t last_loc;
9334 /* We keep track of the last time we issued this error
9335 message to avoid spewing a ton of messages during a
9336 single bad template instantiation. */
9337 if (complain & tf_error
9338 && last_loc != input_location)
9340 if (TREE_CODE (type) == VOID_TYPE)
9341 error ("forming reference to void");
9343 error ("forming %s to reference type %qT",
9344 (code == POINTER_TYPE) ? "pointer" : "reference",
9346 last_loc = input_location;
9349 return error_mark_node;
9351 else if (code == POINTER_TYPE)
9353 r = build_pointer_type (type);
9354 if (TREE_CODE (type) == METHOD_TYPE)
9355 r = build_ptrmemfunc_type (r);
9357 else if (TREE_CODE (type) == REFERENCE_TYPE)
9358 /* In C++0x, during template argument substitution, when there is an
9359 attempt to create a reference to a reference type, reference
9360 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
9362 "If a template-argument for a template-parameter T names a type
9363 that is a reference to a type A, an attempt to create the type
9364 'lvalue reference to cv T' creates the type 'lvalue reference to
9365 A,' while an attempt to create the type type rvalue reference to
9366 cv T' creates the type T"
9368 r = cp_build_reference_type
9370 TYPE_REF_IS_RVALUE (t) && TYPE_REF_IS_RVALUE (type));
9372 r = cp_build_reference_type (type, TYPE_REF_IS_RVALUE (t));
9373 r = cp_build_qualified_type_real (r, TYPE_QUALS (t), complain);
9375 if (r != error_mark_node)
9376 /* Will this ever be needed for TYPE_..._TO values? */
9383 r = tsubst (TYPE_OFFSET_BASETYPE (t), args, complain, in_decl);
9384 if (r == error_mark_node || !MAYBE_CLASS_TYPE_P (r))
9388 Type deduction may fail for any of the following
9391 -- Attempting to create "pointer to member of T" when T
9392 is not a class type. */
9393 if (complain & tf_error)
9394 error ("creating pointer to member of non-class type %qT", r);
9395 return error_mark_node;
9397 if (TREE_CODE (type) == REFERENCE_TYPE)
9399 if (complain & tf_error)
9400 error ("creating pointer to member reference type %qT", type);
9401 return error_mark_node;
9403 if (TREE_CODE (type) == VOID_TYPE)
9405 if (complain & tf_error)
9406 error ("creating pointer to member of type void");
9407 return error_mark_node;
9409 gcc_assert (TREE_CODE (type) != METHOD_TYPE);
9410 if (TREE_CODE (type) == FUNCTION_TYPE)
9412 /* The type of the implicit object parameter gets its
9413 cv-qualifiers from the FUNCTION_TYPE. */
9415 tree this_type = cp_build_qualified_type (TYPE_MAIN_VARIANT (r),
9416 cp_type_quals (type));
9418 method_type = build_method_type_directly (this_type,
9420 TYPE_ARG_TYPES (type));
9421 memptr = build_ptrmemfunc_type (build_pointer_type (method_type));
9422 return cp_build_qualified_type_real (memptr, cp_type_quals (t),
9426 return cp_build_qualified_type_real (build_ptrmem_type (r, type),
9435 fntype = tsubst_function_type (t, args, complain, in_decl);
9436 if (fntype == error_mark_node)
9437 return error_mark_node;
9439 /* Substitute the exception specification. */
9440 specs = tsubst_exception_specification (t, args, complain,
9442 if (specs == error_mark_node)
9443 return error_mark_node;
9445 fntype = build_exception_variant (fntype, specs);
9450 tree domain = tsubst (TYPE_DOMAIN (t), args, complain, in_decl);
9451 if (domain == error_mark_node)
9452 return error_mark_node;
9454 /* As an optimization, we avoid regenerating the array type if
9455 it will obviously be the same as T. */
9456 if (type == TREE_TYPE (t) && domain == TYPE_DOMAIN (t))
9459 /* These checks should match the ones in grokdeclarator.
9463 The deduction may fail for any of the following reasons:
9465 -- Attempting to create an array with an element type that
9466 is void, a function type, or a reference type, or [DR337]
9467 an abstract class type. */
9468 if (TREE_CODE (type) == VOID_TYPE
9469 || TREE_CODE (type) == FUNCTION_TYPE
9470 || TREE_CODE (type) == REFERENCE_TYPE)
9472 if (complain & tf_error)
9473 error ("creating array of %qT", type);
9474 return error_mark_node;
9476 if (CLASS_TYPE_P (type) && CLASSTYPE_PURE_VIRTUALS (type))
9478 if (complain & tf_error)
9479 error ("creating array of %qT, which is an abstract class type",
9481 return error_mark_node;
9484 r = build_cplus_array_type (type, domain);
9486 if (TYPE_USER_ALIGN (t))
9488 TYPE_ALIGN (r) = TYPE_ALIGN (t);
9489 TYPE_USER_ALIGN (r) = 1;
9498 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
9499 tree e2 = tsubst (TREE_OPERAND (t, 1), args, complain, in_decl);
9501 if (e1 == error_mark_node || e2 == error_mark_node)
9502 return error_mark_node;
9504 return fold_build2 (TREE_CODE (t), TREE_TYPE (t), e1, e2);
9510 tree e = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
9511 if (e == error_mark_node)
9512 return error_mark_node;
9514 return fold_build1 (TREE_CODE (t), TREE_TYPE (t), e);
9519 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
9520 in_decl, /*entering_scope=*/1);
9521 tree f = tsubst_copy (TYPENAME_TYPE_FULLNAME (t), args,
9524 if (ctx == error_mark_node || f == error_mark_node)
9525 return error_mark_node;
9527 if (!MAYBE_CLASS_TYPE_P (ctx))
9529 if (complain & tf_error)
9530 error ("%qT is not a class, struct, or union type", ctx);
9531 return error_mark_node;
9533 else if (!uses_template_parms (ctx) && !TYPE_BEING_DEFINED (ctx))
9535 /* Normally, make_typename_type does not require that the CTX
9536 have complete type in order to allow things like:
9538 template <class T> struct S { typename S<T>::X Y; };
9540 But, such constructs have already been resolved by this
9541 point, so here CTX really should have complete type, unless
9542 it's a partial instantiation. */
9543 ctx = complete_type (ctx);
9544 if (!COMPLETE_TYPE_P (ctx))
9546 if (complain & tf_error)
9547 cxx_incomplete_type_error (NULL_TREE, ctx);
9548 return error_mark_node;
9552 f = make_typename_type (ctx, f, typename_type,
9553 (complain & tf_error) | tf_keep_type_decl);
9554 if (f == error_mark_node)
9556 if (TREE_CODE (f) == TYPE_DECL)
9558 complain |= tf_ignore_bad_quals;
9562 if (TREE_CODE (f) != TYPENAME_TYPE)
9564 if (TYPENAME_IS_ENUM_P (t) && TREE_CODE (f) != ENUMERAL_TYPE)
9565 error ("%qT resolves to %qT, which is not an enumeration type",
9567 else if (TYPENAME_IS_CLASS_P (t) && !CLASS_TYPE_P (f))
9568 error ("%qT resolves to %qT, which is is not a class type",
9572 return cp_build_qualified_type_real
9573 (f, cp_type_quals (f) | cp_type_quals (t), complain);
9576 case UNBOUND_CLASS_TEMPLATE:
9578 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
9579 in_decl, /*entering_scope=*/1);
9580 tree name = TYPE_IDENTIFIER (t);
9581 tree parm_list = DECL_TEMPLATE_PARMS (TYPE_NAME (t));
9583 if (ctx == error_mark_node || name == error_mark_node)
9584 return error_mark_node;
9587 parm_list = tsubst_template_parms (parm_list, args, complain);
9588 return make_unbound_class_template (ctx, name, parm_list, complain);
9598 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
9599 tree e2 = tsubst_expr (TREE_OPERAND (t, 1), args, complain, in_decl,
9600 /*integral_constant_expression_p=*/false);
9601 if (e1 == error_mark_node || e2 == error_mark_node)
9602 return error_mark_node;
9604 return build_nt (ARRAY_REF, e1, e2, NULL_TREE, NULL_TREE);
9609 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
9610 tree e2 = tsubst (TREE_OPERAND (t, 1), args, complain, in_decl);
9611 if (e1 == error_mark_node || e2 == error_mark_node)
9612 return error_mark_node;
9614 return build_qualified_name (/*type=*/NULL_TREE,
9615 e1, e2, QUALIFIED_NAME_IS_TEMPLATE (t));
9622 type = finish_typeof (tsubst_expr
9623 (TYPEOF_TYPE_EXPR (t), args,
9625 /*integral_constant_expression_p=*/false));
9626 return cp_build_qualified_type_real (type,
9628 | cp_type_quals (type),
9638 type = tsubst_expr (DECLTYPE_TYPE_EXPR (t), args,
9640 /*integral_constant_expression_p=*/false);
9645 finish_decltype_type (type,
9646 DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t));
9647 return cp_build_qualified_type_real (type,
9649 | cp_type_quals (type),
9653 case TYPE_ARGUMENT_PACK:
9654 case NONTYPE_ARGUMENT_PACK:
9656 tree r = make_node (TREE_CODE (t));
9658 tsubst_template_args (ARGUMENT_PACK_ARGS (t),
9662 SET_ARGUMENT_PACK_ARGS (r, packed_out);
9664 /* For template nontype argument packs, also substitute into
9666 if (TREE_CODE (t) == NONTYPE_ARGUMENT_PACK)
9667 TREE_TYPE (r) = tsubst (TREE_TYPE (t), args, complain, in_decl);
9674 sorry ("use of %qs in template",
9675 tree_code_name [(int) TREE_CODE (t)]);
9676 return error_mark_node;
9680 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
9681 type of the expression on the left-hand side of the "." or "->"
9685 tsubst_baselink (tree baselink, tree object_type,
9686 tree args, tsubst_flags_t complain, tree in_decl)
9689 tree qualifying_scope;
9692 tree template_args = 0;
9693 bool template_id_p = false;
9695 /* A baselink indicates a function from a base class. Both the
9696 BASELINK_ACCESS_BINFO and the base class referenced may
9697 indicate bases of the template class, rather than the
9698 instantiated class. In addition, lookups that were not
9699 ambiguous before may be ambiguous now. Therefore, we perform
9700 the lookup again. */
9701 qualifying_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (baselink));
9702 qualifying_scope = tsubst (qualifying_scope, args,
9704 fns = BASELINK_FUNCTIONS (baselink);
9705 optype = BASELINK_OPTYPE (baselink);
9706 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
9708 template_id_p = true;
9709 template_args = TREE_OPERAND (fns, 1);
9710 fns = TREE_OPERAND (fns, 0);
9712 template_args = tsubst_template_args (template_args, args,
9715 name = DECL_NAME (get_first_fn (fns));
9716 baselink = lookup_fnfields (qualifying_scope, name, /*protect=*/1);
9718 /* If lookup found a single function, mark it as used at this
9719 point. (If it lookup found multiple functions the one selected
9720 later by overload resolution will be marked as used at that
9722 if (BASELINK_P (baselink))
9723 fns = BASELINK_FUNCTIONS (baselink);
9724 if (!template_id_p && !really_overloaded_fn (fns))
9725 mark_used (OVL_CURRENT (fns));
9727 /* Add back the template arguments, if present. */
9728 if (BASELINK_P (baselink) && template_id_p)
9729 BASELINK_FUNCTIONS (baselink)
9730 = build_nt (TEMPLATE_ID_EXPR,
9731 BASELINK_FUNCTIONS (baselink),
9733 /* Update the conversion operator type. */
9734 BASELINK_OPTYPE (baselink)
9735 = tsubst (optype, args, complain, in_decl);
9738 object_type = current_class_type;
9739 return adjust_result_of_qualified_name_lookup (baselink,
9744 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
9745 true if the qualified-id will be a postfix-expression in-and-of
9746 itself; false if more of the postfix-expression follows the
9747 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
9751 tsubst_qualified_id (tree qualified_id, tree args,
9752 tsubst_flags_t complain, tree in_decl,
9753 bool done, bool address_p)
9761 gcc_assert (TREE_CODE (qualified_id) == SCOPE_REF);
9763 /* Figure out what name to look up. */
9764 name = TREE_OPERAND (qualified_id, 1);
9765 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
9768 template_args = TREE_OPERAND (name, 1);
9770 template_args = tsubst_template_args (template_args, args,
9772 name = TREE_OPERAND (name, 0);
9776 is_template = false;
9777 template_args = NULL_TREE;
9780 /* Substitute into the qualifying scope. When there are no ARGS, we
9781 are just trying to simplify a non-dependent expression. In that
9782 case the qualifying scope may be dependent, and, in any case,
9783 substituting will not help. */
9784 scope = TREE_OPERAND (qualified_id, 0);
9787 scope = tsubst (scope, args, complain, in_decl);
9788 expr = tsubst_copy (name, args, complain, in_decl);
9793 if (dependent_type_p (scope))
9794 return build_qualified_name (/*type=*/NULL_TREE,
9796 QUALIFIED_NAME_IS_TEMPLATE (qualified_id));
9798 if (!BASELINK_P (name) && !DECL_P (expr))
9800 if (TREE_CODE (expr) == BIT_NOT_EXPR)
9801 /* If this were actually a destructor call, it would have been
9802 parsed as such by the parser. */
9803 expr = error_mark_node;
9805 expr = lookup_qualified_name (scope, expr, /*is_type_p=*/0, false);
9806 if (TREE_CODE (TREE_CODE (expr) == TEMPLATE_DECL
9807 ? DECL_TEMPLATE_RESULT (expr) : expr) == TYPE_DECL)
9809 if (complain & tf_error)
9811 error ("dependent-name %qE is parsed as a non-type, but "
9812 "instantiation yields a type", qualified_id);
9813 inform (input_location, "say %<typename %E%> if a type is meant", qualified_id);
9815 return error_mark_node;
9821 check_accessibility_of_qualified_id (expr, /*object_type=*/NULL_TREE,
9823 /* Remember that there was a reference to this entity. */
9827 if (expr == error_mark_node || TREE_CODE (expr) == TREE_LIST)
9829 if (complain & tf_error)
9830 qualified_name_lookup_error (scope,
9831 TREE_OPERAND (qualified_id, 1),
9832 expr, input_location);
9833 return error_mark_node;
9837 expr = lookup_template_function (expr, template_args);
9839 if (expr == error_mark_node && complain & tf_error)
9840 qualified_name_lookup_error (scope, TREE_OPERAND (qualified_id, 1),
9841 expr, input_location);
9842 else if (TYPE_P (scope))
9844 expr = (adjust_result_of_qualified_name_lookup
9845 (expr, scope, current_class_type));
9846 expr = (finish_qualified_id_expr
9847 (scope, expr, done, address_p,
9848 QUALIFIED_NAME_IS_TEMPLATE (qualified_id),
9849 /*template_arg_p=*/false));
9852 /* Expressions do not generally have reference type. */
9853 if (TREE_CODE (expr) != SCOPE_REF
9854 /* However, if we're about to form a pointer-to-member, we just
9855 want the referenced member referenced. */
9856 && TREE_CODE (expr) != OFFSET_REF)
9857 expr = convert_from_reference (expr);
9862 /* Like tsubst, but deals with expressions. This function just replaces
9863 template parms; to finish processing the resultant expression, use
9867 tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl)
9869 enum tree_code code;
9872 if (t == NULL_TREE || t == error_mark_node)
9875 code = TREE_CODE (t);
9880 r = retrieve_local_specialization (t);
9884 /* This can happen for a parameter name used later in a function
9885 declaration (such as in a late-specified return type).
9886 Replace it with an arbitrary expression with the same type
9887 (*(T*)0). This should only occur in an unevaluated context
9889 gcc_assert (skip_evaluation);
9890 r = non_reference (TREE_TYPE (t));
9891 r = tsubst (r, args, complain, in_decl);
9892 r = build_pointer_type (r);
9893 r = build_c_cast (r, null_node);
9894 return cp_build_indirect_ref (r, NULL, tf_warning_or_error);
9897 if (TREE_CODE (r) == ARGUMENT_PACK_SELECT)
9898 r = ARGUMENT_PACK_SELECT_ARG (r);
9907 if (DECL_TEMPLATE_PARM_P (t))
9908 return tsubst_copy (DECL_INITIAL (t), args, complain, in_decl);
9909 /* There is no need to substitute into namespace-scope
9911 if (DECL_NAMESPACE_SCOPE_P (t))
9913 /* If ARGS is NULL, then T is known to be non-dependent. */
9914 if (args == NULL_TREE)
9915 return integral_constant_value (t);
9917 /* Unfortunately, we cannot just call lookup_name here.
9920 template <int I> int f() {
9922 struct S { void g() { E e = a; } };
9925 When we instantiate f<7>::S::g(), say, lookup_name is not
9926 clever enough to find f<7>::a. */
9928 = tsubst_aggr_type (TREE_TYPE (t), args, complain, in_decl,
9929 /*entering_scope=*/0);
9931 for (v = TYPE_VALUES (enum_type);
9934 if (TREE_PURPOSE (v) == DECL_NAME (t))
9935 return TREE_VALUE (v);
9937 /* We didn't find the name. That should never happen; if
9938 name-lookup found it during preliminary parsing, we
9939 should find it again here during instantiation. */
9945 if (DECL_CONTEXT (t))
9949 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args, complain, in_decl,
9950 /*entering_scope=*/1);
9951 if (ctx != DECL_CONTEXT (t))
9953 tree r = lookup_field (ctx, DECL_NAME (t), 0, false);
9956 if (complain & tf_error)
9957 error ("using invalid field %qD", t);
9958 return error_mark_node;
9968 if ((DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t))
9969 || local_variable_p (t))
9970 t = tsubst (t, args, complain, in_decl);
9975 return tsubst_baselink (t, current_class_type, args, complain, in_decl);
9978 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
9979 return tsubst (TREE_TYPE (DECL_TEMPLATE_RESULT (t)),
9980 args, complain, in_decl);
9981 else if (DECL_FUNCTION_TEMPLATE_P (t) && DECL_MEMBER_TEMPLATE_P (t))
9982 return tsubst (t, args, complain, in_decl);
9983 else if (DECL_CLASS_SCOPE_P (t)
9984 && uses_template_parms (DECL_CONTEXT (t)))
9986 /* Template template argument like the following example need
9989 template <template <class> class TT> struct C {};
9990 template <class T> struct D {
9991 template <class U> struct E {};
9996 We are processing the template argument `E' in #1 for
9997 the template instantiation #2. Originally, `E' is a
9998 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
9999 have to substitute this with one having context `D<int>'. */
10001 tree context = tsubst (DECL_CONTEXT (t), args, complain, in_decl);
10002 return lookup_field (context, DECL_NAME(t), 0, false);
10005 /* Ordinary template template argument. */
10009 case REINTERPRET_CAST_EXPR:
10010 case CONST_CAST_EXPR:
10011 case STATIC_CAST_EXPR:
10012 case DYNAMIC_CAST_EXPR:
10015 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
10016 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
10019 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
10021 /* We only want to compute the number of arguments. */
10022 tree expanded = tsubst_pack_expansion (TREE_OPERAND (t, 0), args,
10023 complain, in_decl);
10026 if (TREE_CODE (expanded) == TREE_VEC)
10027 len = TREE_VEC_LENGTH (expanded);
10029 if (expanded == error_mark_node)
10030 return error_mark_node;
10031 else if (PACK_EXPANSION_P (expanded)
10032 || (TREE_CODE (expanded) == TREE_VEC
10034 && PACK_EXPANSION_P (TREE_VEC_ELT (expanded, len-1))))
10036 if (TREE_CODE (expanded) == TREE_VEC)
10037 expanded = TREE_VEC_ELT (expanded, len - 1);
10039 if (TYPE_P (expanded))
10040 return cxx_sizeof_or_alignof_type (expanded, SIZEOF_EXPR,
10041 complain & tf_error);
10043 return cxx_sizeof_or_alignof_expr (expanded, SIZEOF_EXPR,
10044 complain & tf_error);
10047 return build_int_cst (size_type_node, len);
10053 case TRUTH_NOT_EXPR:
10056 case UNARY_PLUS_EXPR: /* Unary + */
10061 case REALPART_EXPR:
10062 case IMAGPART_EXPR:
10064 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
10065 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
10067 case COMPONENT_REF:
10072 object = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
10073 name = TREE_OPERAND (t, 1);
10074 if (TREE_CODE (name) == BIT_NOT_EXPR)
10076 name = tsubst_copy (TREE_OPERAND (name, 0), args,
10077 complain, in_decl);
10078 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
10080 else if (TREE_CODE (name) == SCOPE_REF
10081 && TREE_CODE (TREE_OPERAND (name, 1)) == BIT_NOT_EXPR)
10083 tree base = tsubst_copy (TREE_OPERAND (name, 0), args,
10084 complain, in_decl);
10085 name = TREE_OPERAND (name, 1);
10086 name = tsubst_copy (TREE_OPERAND (name, 0), args,
10087 complain, in_decl);
10088 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
10089 name = build_qualified_name (/*type=*/NULL_TREE,
10091 /*template_p=*/false);
10093 else if (TREE_CODE (name) == BASELINK)
10094 name = tsubst_baselink (name,
10095 non_reference (TREE_TYPE (object)),
10099 name = tsubst_copy (name, args, complain, in_decl);
10100 return build_nt (COMPONENT_REF, object, name, NULL_TREE);
10106 case TRUNC_DIV_EXPR:
10107 case CEIL_DIV_EXPR:
10108 case FLOOR_DIV_EXPR:
10109 case ROUND_DIV_EXPR:
10110 case EXACT_DIV_EXPR:
10114 case TRUNC_MOD_EXPR:
10115 case FLOOR_MOD_EXPR:
10116 case TRUTH_ANDIF_EXPR:
10117 case TRUTH_ORIF_EXPR:
10118 case TRUTH_AND_EXPR:
10119 case TRUTH_OR_EXPR:
10132 case COMPOUND_EXPR:
10135 case PREDECREMENT_EXPR:
10136 case PREINCREMENT_EXPR:
10137 case POSTDECREMENT_EXPR:
10138 case POSTINCREMENT_EXPR:
10140 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
10141 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
10144 return build_qualified_name (/*type=*/NULL_TREE,
10145 tsubst_copy (TREE_OPERAND (t, 0),
10146 args, complain, in_decl),
10147 tsubst_copy (TREE_OPERAND (t, 1),
10148 args, complain, in_decl),
10149 QUALIFIED_NAME_IS_TEMPLATE (t));
10154 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
10155 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
10156 NULL_TREE, NULL_TREE);
10160 int n = VL_EXP_OPERAND_LENGTH (t);
10161 tree result = build_vl_exp (CALL_EXPR, n);
10163 for (i = 0; i < n; i++)
10164 TREE_OPERAND (t, i) = tsubst_copy (TREE_OPERAND (t, i), args,
10165 complain, in_decl);
10171 case PSEUDO_DTOR_EXPR:
10174 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
10175 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
10176 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
10177 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
10184 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
10185 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
10186 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
10187 NEW_EXPR_USE_GLOBAL (r) = NEW_EXPR_USE_GLOBAL (t);
10194 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
10195 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
10196 DELETE_EXPR_USE_GLOBAL (r) = DELETE_EXPR_USE_GLOBAL (t);
10197 DELETE_EXPR_USE_VEC (r) = DELETE_EXPR_USE_VEC (t);
10201 case TEMPLATE_ID_EXPR:
10203 /* Substituted template arguments */
10204 tree fn = TREE_OPERAND (t, 0);
10205 tree targs = TREE_OPERAND (t, 1);
10207 fn = tsubst_copy (fn, args, complain, in_decl);
10209 targs = tsubst_template_args (targs, args, complain, in_decl);
10211 return lookup_template_function (fn, targs);
10216 tree purpose, value, chain;
10218 if (t == void_list_node)
10221 purpose = TREE_PURPOSE (t);
10223 purpose = tsubst_copy (purpose, args, complain, in_decl);
10224 value = TREE_VALUE (t);
10226 value = tsubst_copy (value, args, complain, in_decl);
10227 chain = TREE_CHAIN (t);
10228 if (chain && chain != void_type_node)
10229 chain = tsubst_copy (chain, args, complain, in_decl);
10230 if (purpose == TREE_PURPOSE (t)
10231 && value == TREE_VALUE (t)
10232 && chain == TREE_CHAIN (t))
10234 return tree_cons (purpose, value, chain);
10239 case ENUMERAL_TYPE:
10241 case TEMPLATE_TYPE_PARM:
10242 case TEMPLATE_TEMPLATE_PARM:
10243 case BOUND_TEMPLATE_TEMPLATE_PARM:
10244 case TEMPLATE_PARM_INDEX:
10246 case REFERENCE_TYPE:
10248 case FUNCTION_TYPE:
10251 case TYPENAME_TYPE:
10252 case UNBOUND_CLASS_TEMPLATE:
10254 case DECLTYPE_TYPE:
10256 return tsubst (t, args, complain, in_decl);
10258 case IDENTIFIER_NODE:
10259 if (IDENTIFIER_TYPENAME_P (t))
10261 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10262 return mangle_conv_op_name_for_type (new_type);
10268 /* This is handled by tsubst_copy_and_build. */
10269 gcc_unreachable ();
10272 return build_x_va_arg (tsubst_copy (TREE_OPERAND (t, 0), args, complain,
10274 tsubst (TREE_TYPE (t), args, complain, in_decl));
10276 case CLEANUP_POINT_EXPR:
10277 /* We shouldn't have built any of these during initial template
10278 generation. Instead, they should be built during instantiation
10279 in response to the saved STMT_IS_FULL_EXPR_P setting. */
10280 gcc_unreachable ();
10283 mark_used (TREE_OPERAND (t, 1));
10286 case EXPR_PACK_EXPANSION:
10287 error ("invalid use of pack expansion expression");
10288 return error_mark_node;
10290 case NONTYPE_ARGUMENT_PACK:
10291 error ("use %<...%> to expand argument pack");
10292 return error_mark_node;
10299 /* Like tsubst_copy, but specifically for OpenMP clauses. */
10302 tsubst_omp_clauses (tree clauses, tree args, tsubst_flags_t complain,
10305 tree new_clauses = NULL, nc, oc;
10307 for (oc = clauses; oc ; oc = OMP_CLAUSE_CHAIN (oc))
10309 nc = copy_node (oc);
10310 OMP_CLAUSE_CHAIN (nc) = new_clauses;
10313 switch (OMP_CLAUSE_CODE (nc))
10315 case OMP_CLAUSE_LASTPRIVATE:
10316 if (OMP_CLAUSE_LASTPRIVATE_STMT (oc))
10318 OMP_CLAUSE_LASTPRIVATE_STMT (nc) = push_stmt_list ();
10319 tsubst_expr (OMP_CLAUSE_LASTPRIVATE_STMT (oc), args, complain,
10320 in_decl, /*integral_constant_expression_p=*/false);
10321 OMP_CLAUSE_LASTPRIVATE_STMT (nc)
10322 = pop_stmt_list (OMP_CLAUSE_LASTPRIVATE_STMT (nc));
10325 case OMP_CLAUSE_PRIVATE:
10326 case OMP_CLAUSE_SHARED:
10327 case OMP_CLAUSE_FIRSTPRIVATE:
10328 case OMP_CLAUSE_REDUCTION:
10329 case OMP_CLAUSE_COPYIN:
10330 case OMP_CLAUSE_COPYPRIVATE:
10331 case OMP_CLAUSE_IF:
10332 case OMP_CLAUSE_NUM_THREADS:
10333 case OMP_CLAUSE_SCHEDULE:
10334 case OMP_CLAUSE_COLLAPSE:
10335 OMP_CLAUSE_OPERAND (nc, 0)
10336 = tsubst_expr (OMP_CLAUSE_OPERAND (oc, 0), args, complain,
10337 in_decl, /*integral_constant_expression_p=*/false);
10339 case OMP_CLAUSE_NOWAIT:
10340 case OMP_CLAUSE_ORDERED:
10341 case OMP_CLAUSE_DEFAULT:
10342 case OMP_CLAUSE_UNTIED:
10345 gcc_unreachable ();
10349 return finish_omp_clauses (nreverse (new_clauses));
10352 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
10355 tsubst_copy_asm_operands (tree t, tree args, tsubst_flags_t complain,
10358 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
10360 tree purpose, value, chain;
10365 if (TREE_CODE (t) != TREE_LIST)
10366 return tsubst_copy_and_build (t, args, complain, in_decl,
10367 /*function_p=*/false,
10368 /*integral_constant_expression_p=*/false);
10370 if (t == void_list_node)
10373 purpose = TREE_PURPOSE (t);
10375 purpose = RECUR (purpose);
10376 value = TREE_VALUE (t);
10378 value = RECUR (value);
10379 chain = TREE_CHAIN (t);
10380 if (chain && chain != void_type_node)
10381 chain = RECUR (chain);
10382 return tree_cons (purpose, value, chain);
10386 /* Substitute one OMP_FOR iterator. */
10389 tsubst_omp_for_iterator (tree t, int i, tree declv, tree initv,
10390 tree condv, tree incrv, tree *clauses,
10391 tree args, tsubst_flags_t complain, tree in_decl,
10392 bool integral_constant_expression_p)
10394 #define RECUR(NODE) \
10395 tsubst_expr ((NODE), args, complain, in_decl, \
10396 integral_constant_expression_p)
10397 tree decl, init, cond, incr, auto_node;
10399 init = TREE_VEC_ELT (OMP_FOR_INIT (t), i);
10400 gcc_assert (TREE_CODE (init) == MODIFY_EXPR);
10401 decl = RECUR (TREE_OPERAND (init, 0));
10402 init = TREE_OPERAND (init, 1);
10403 auto_node = type_uses_auto (TREE_TYPE (decl));
10404 if (auto_node && init)
10406 tree init_expr = init;
10407 if (TREE_CODE (init_expr) == DECL_EXPR)
10408 init_expr = DECL_INITIAL (DECL_EXPR_DECL (init_expr));
10409 init_expr = RECUR (init_expr);
10411 = do_auto_deduction (TREE_TYPE (decl), init_expr, auto_node);
10413 gcc_assert (!type_dependent_expression_p (decl));
10415 if (!CLASS_TYPE_P (TREE_TYPE (decl)))
10417 cond = RECUR (TREE_VEC_ELT (OMP_FOR_COND (t), i));
10418 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
10419 if (TREE_CODE (incr) == MODIFY_EXPR)
10420 incr = build_x_modify_expr (RECUR (TREE_OPERAND (incr, 0)), NOP_EXPR,
10421 RECUR (TREE_OPERAND (incr, 1)),
10424 incr = RECUR (incr);
10425 TREE_VEC_ELT (declv, i) = decl;
10426 TREE_VEC_ELT (initv, i) = init;
10427 TREE_VEC_ELT (condv, i) = cond;
10428 TREE_VEC_ELT (incrv, i) = incr;
10432 if (init && TREE_CODE (init) != DECL_EXPR)
10435 for (c = *clauses; c ; c = OMP_CLAUSE_CHAIN (c))
10437 if ((OMP_CLAUSE_CODE (c) == OMP_CLAUSE_PRIVATE
10438 || OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LASTPRIVATE)
10439 && OMP_CLAUSE_DECL (c) == decl)
10441 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_FIRSTPRIVATE
10442 && OMP_CLAUSE_DECL (c) == decl)
10443 error ("iteration variable %qD should not be firstprivate", decl);
10444 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_REDUCTION
10445 && OMP_CLAUSE_DECL (c) == decl)
10446 error ("iteration variable %qD should not be reduction", decl);
10450 c = build_omp_clause (OMP_CLAUSE_PRIVATE);
10451 OMP_CLAUSE_DECL (c) = decl;
10452 c = finish_omp_clauses (c);
10455 OMP_CLAUSE_CHAIN (c) = *clauses;
10460 cond = TREE_VEC_ELT (OMP_FOR_COND (t), i);
10461 if (COMPARISON_CLASS_P (cond))
10462 cond = build2 (TREE_CODE (cond), boolean_type_node,
10463 RECUR (TREE_OPERAND (cond, 0)),
10464 RECUR (TREE_OPERAND (cond, 1)));
10466 cond = RECUR (cond);
10467 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
10468 switch (TREE_CODE (incr))
10470 case PREINCREMENT_EXPR:
10471 case PREDECREMENT_EXPR:
10472 case POSTINCREMENT_EXPR:
10473 case POSTDECREMENT_EXPR:
10474 incr = build2 (TREE_CODE (incr), TREE_TYPE (decl),
10475 RECUR (TREE_OPERAND (incr, 0)), NULL_TREE);
10478 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
10479 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
10481 tree rhs = TREE_OPERAND (incr, 1);
10482 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
10483 RECUR (TREE_OPERAND (incr, 0)),
10484 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
10485 RECUR (TREE_OPERAND (rhs, 0)),
10486 RECUR (TREE_OPERAND (rhs, 1))));
10489 incr = RECUR (incr);
10492 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
10493 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
10495 tree lhs = RECUR (TREE_OPERAND (incr, 0));
10496 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl), lhs,
10497 build2 (TREE_CODE (TREE_OPERAND (incr, 1)),
10498 TREE_TYPE (decl), lhs,
10499 RECUR (TREE_OPERAND (incr, 2))));
10501 else if (TREE_CODE (TREE_OPERAND (incr, 1)) == NOP_EXPR
10502 && (TREE_CODE (TREE_OPERAND (incr, 2)) == PLUS_EXPR
10503 || (TREE_CODE (TREE_OPERAND (incr, 2)) == MINUS_EXPR)))
10505 tree rhs = TREE_OPERAND (incr, 2);
10506 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
10507 RECUR (TREE_OPERAND (incr, 0)),
10508 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
10509 RECUR (TREE_OPERAND (rhs, 0)),
10510 RECUR (TREE_OPERAND (rhs, 1))));
10513 incr = RECUR (incr);
10516 incr = RECUR (incr);
10520 TREE_VEC_ELT (declv, i) = decl;
10521 TREE_VEC_ELT (initv, i) = init;
10522 TREE_VEC_ELT (condv, i) = cond;
10523 TREE_VEC_ELT (incrv, i) = incr;
10527 /* Like tsubst_copy for expressions, etc. but also does semantic
10531 tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl,
10532 bool integral_constant_expression_p)
10534 #define RECUR(NODE) \
10535 tsubst_expr ((NODE), args, complain, in_decl, \
10536 integral_constant_expression_p)
10540 if (t == NULL_TREE || t == error_mark_node)
10543 if (EXPR_HAS_LOCATION (t))
10544 input_location = EXPR_LOCATION (t);
10545 if (STATEMENT_CODE_P (TREE_CODE (t)))
10546 current_stmt_tree ()->stmts_are_full_exprs_p = STMT_IS_FULL_EXPR_P (t);
10548 switch (TREE_CODE (t))
10550 case STATEMENT_LIST:
10552 tree_stmt_iterator i;
10553 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
10554 RECUR (tsi_stmt (i));
10558 case CTOR_INITIALIZER:
10559 finish_mem_initializers (tsubst_initializer_list
10560 (TREE_OPERAND (t, 0), args));
10564 finish_return_stmt (RECUR (TREE_OPERAND (t, 0)));
10568 tmp = RECUR (EXPR_STMT_EXPR (t));
10569 if (EXPR_STMT_STMT_EXPR_RESULT (t))
10570 finish_stmt_expr_expr (tmp, cur_stmt_expr);
10572 finish_expr_stmt (tmp);
10576 do_using_directive (RECUR (USING_STMT_NAMESPACE (t)));
10584 decl = DECL_EXPR_DECL (t);
10585 if (TREE_CODE (decl) == LABEL_DECL)
10586 finish_label_decl (DECL_NAME (decl));
10587 else if (TREE_CODE (decl) == USING_DECL)
10589 tree scope = USING_DECL_SCOPE (decl);
10590 tree name = DECL_NAME (decl);
10593 scope = RECUR (scope);
10594 decl = lookup_qualified_name (scope, name,
10595 /*is_type_p=*/false,
10596 /*complain=*/false);
10597 if (decl == error_mark_node || TREE_CODE (decl) == TREE_LIST)
10598 qualified_name_lookup_error (scope, name, decl, input_location);
10600 do_local_using_decl (decl, scope, name);
10604 init = DECL_INITIAL (decl);
10605 decl = tsubst (decl, args, complain, in_decl);
10606 if (decl != error_mark_node)
10608 /* By marking the declaration as instantiated, we avoid
10609 trying to instantiate it. Since instantiate_decl can't
10610 handle local variables, and since we've already done
10611 all that needs to be done, that's the right thing to
10613 if (TREE_CODE (decl) == VAR_DECL)
10614 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
10615 if (TREE_CODE (decl) == VAR_DECL
10616 && ANON_AGGR_TYPE_P (TREE_TYPE (decl)))
10617 /* Anonymous aggregates are a special case. */
10618 finish_anon_union (decl);
10621 maybe_push_decl (decl);
10622 if (TREE_CODE (decl) == VAR_DECL
10623 && DECL_PRETTY_FUNCTION_P (decl))
10625 /* For __PRETTY_FUNCTION__ we have to adjust the
10627 const char *const name
10628 = cxx_printable_name (current_function_decl, 2);
10629 init = cp_fname_init (name, &TREE_TYPE (decl));
10633 tree t = RECUR (init);
10636 /* If we had an initializer but it
10637 instantiated to nothing,
10638 value-initialize the object. This will
10639 only occur when the initializer was a
10640 pack expansion where the parameter packs
10641 used in that expansion were of length
10643 init = build_value_init (TREE_TYPE (decl));
10648 finish_decl (decl, init, NULL_TREE);
10653 /* A DECL_EXPR can also be used as an expression, in the condition
10654 clause of an if/for/while construct. */
10659 stmt = begin_for_stmt ();
10660 RECUR (FOR_INIT_STMT (t));
10661 finish_for_init_stmt (stmt);
10662 tmp = RECUR (FOR_COND (t));
10663 finish_for_cond (tmp, stmt);
10664 tmp = RECUR (FOR_EXPR (t));
10665 finish_for_expr (tmp, stmt);
10666 RECUR (FOR_BODY (t));
10667 finish_for_stmt (stmt);
10671 stmt = begin_while_stmt ();
10672 tmp = RECUR (WHILE_COND (t));
10673 finish_while_stmt_cond (tmp, stmt);
10674 RECUR (WHILE_BODY (t));
10675 finish_while_stmt (stmt);
10679 stmt = begin_do_stmt ();
10680 RECUR (DO_BODY (t));
10681 finish_do_body (stmt);
10682 tmp = RECUR (DO_COND (t));
10683 finish_do_stmt (tmp, stmt);
10687 stmt = begin_if_stmt ();
10688 tmp = RECUR (IF_COND (t));
10689 finish_if_stmt_cond (tmp, stmt);
10690 RECUR (THEN_CLAUSE (t));
10691 finish_then_clause (stmt);
10693 if (ELSE_CLAUSE (t))
10695 begin_else_clause (stmt);
10696 RECUR (ELSE_CLAUSE (t));
10697 finish_else_clause (stmt);
10700 finish_if_stmt (stmt);
10704 if (BIND_EXPR_BODY_BLOCK (t))
10705 stmt = begin_function_body ();
10707 stmt = begin_compound_stmt (BIND_EXPR_TRY_BLOCK (t)
10708 ? BCS_TRY_BLOCK : 0);
10710 RECUR (BIND_EXPR_BODY (t));
10712 if (BIND_EXPR_BODY_BLOCK (t))
10713 finish_function_body (stmt);
10715 finish_compound_stmt (stmt);
10719 finish_break_stmt ();
10722 case CONTINUE_STMT:
10723 finish_continue_stmt ();
10727 stmt = begin_switch_stmt ();
10728 tmp = RECUR (SWITCH_STMT_COND (t));
10729 finish_switch_cond (tmp, stmt);
10730 RECUR (SWITCH_STMT_BODY (t));
10731 finish_switch_stmt (stmt);
10734 case CASE_LABEL_EXPR:
10735 finish_case_label (RECUR (CASE_LOW (t)),
10736 RECUR (CASE_HIGH (t)));
10740 finish_label_stmt (DECL_NAME (LABEL_EXPR_LABEL (t)));
10744 tmp = GOTO_DESTINATION (t);
10745 if (TREE_CODE (tmp) != LABEL_DECL)
10746 /* Computed goto's must be tsubst'd into. On the other hand,
10747 non-computed gotos must not be; the identifier in question
10748 will have no binding. */
10751 tmp = DECL_NAME (tmp);
10752 finish_goto_stmt (tmp);
10756 tmp = finish_asm_stmt
10757 (ASM_VOLATILE_P (t),
10758 RECUR (ASM_STRING (t)),
10759 tsubst_copy_asm_operands (ASM_OUTPUTS (t), args, complain, in_decl),
10760 tsubst_copy_asm_operands (ASM_INPUTS (t), args, complain, in_decl),
10761 tsubst_copy_asm_operands (ASM_CLOBBERS (t), args, complain, in_decl));
10763 tree asm_expr = tmp;
10764 if (TREE_CODE (asm_expr) == CLEANUP_POINT_EXPR)
10765 asm_expr = TREE_OPERAND (asm_expr, 0);
10766 ASM_INPUT_P (asm_expr) = ASM_INPUT_P (t);
10773 stmt = begin_try_block ();
10774 RECUR (TRY_STMTS (t));
10775 finish_cleanup_try_block (stmt);
10776 finish_cleanup (RECUR (TRY_HANDLERS (t)), stmt);
10780 tree compound_stmt = NULL_TREE;
10782 if (FN_TRY_BLOCK_P (t))
10783 stmt = begin_function_try_block (&compound_stmt);
10785 stmt = begin_try_block ();
10787 RECUR (TRY_STMTS (t));
10789 if (FN_TRY_BLOCK_P (t))
10790 finish_function_try_block (stmt);
10792 finish_try_block (stmt);
10794 RECUR (TRY_HANDLERS (t));
10795 if (FN_TRY_BLOCK_P (t))
10796 finish_function_handler_sequence (stmt, compound_stmt);
10798 finish_handler_sequence (stmt);
10804 tree decl = HANDLER_PARMS (t);
10808 decl = tsubst (decl, args, complain, in_decl);
10809 /* Prevent instantiate_decl from trying to instantiate
10810 this variable. We've already done all that needs to be
10812 if (decl != error_mark_node)
10813 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
10815 stmt = begin_handler ();
10816 finish_handler_parms (decl, stmt);
10817 RECUR (HANDLER_BODY (t));
10818 finish_handler (stmt);
10823 tsubst (TREE_TYPE (t), args, complain, NULL_TREE);
10826 case STATIC_ASSERT:
10829 tsubst_expr (STATIC_ASSERT_CONDITION (t),
10832 /*integral_constant_expression_p=*/true);
10833 finish_static_assert (condition,
10834 STATIC_ASSERT_MESSAGE (t),
10835 STATIC_ASSERT_SOURCE_LOCATION (t),
10836 /*member_p=*/false);
10841 tmp = tsubst_omp_clauses (OMP_PARALLEL_CLAUSES (t),
10842 args, complain, in_decl);
10843 stmt = begin_omp_parallel ();
10844 RECUR (OMP_PARALLEL_BODY (t));
10845 OMP_PARALLEL_COMBINED (finish_omp_parallel (tmp, stmt))
10846 = OMP_PARALLEL_COMBINED (t);
10850 tmp = tsubst_omp_clauses (OMP_TASK_CLAUSES (t),
10851 args, complain, in_decl);
10852 stmt = begin_omp_task ();
10853 RECUR (OMP_TASK_BODY (t));
10854 finish_omp_task (tmp, stmt);
10859 tree clauses, body, pre_body;
10860 tree declv, initv, condv, incrv;
10863 clauses = tsubst_omp_clauses (OMP_FOR_CLAUSES (t),
10864 args, complain, in_decl);
10865 declv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
10866 initv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
10867 condv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
10868 incrv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
10870 for (i = 0; i < TREE_VEC_LENGTH (OMP_FOR_INIT (t)); i++)
10871 tsubst_omp_for_iterator (t, i, declv, initv, condv, incrv,
10872 &clauses, args, complain, in_decl,
10873 integral_constant_expression_p);
10875 stmt = begin_omp_structured_block ();
10877 for (i = 0; i < TREE_VEC_LENGTH (initv); i++)
10878 if (TREE_VEC_ELT (initv, i) == NULL
10879 || TREE_CODE (TREE_VEC_ELT (initv, i)) != DECL_EXPR)
10880 TREE_VEC_ELT (initv, i) = RECUR (TREE_VEC_ELT (initv, i));
10881 else if (CLASS_TYPE_P (TREE_TYPE (TREE_VEC_ELT (initv, i))))
10883 tree init = RECUR (TREE_VEC_ELT (initv, i));
10884 gcc_assert (init == TREE_VEC_ELT (declv, i));
10885 TREE_VEC_ELT (initv, i) = NULL_TREE;
10889 tree decl_expr = TREE_VEC_ELT (initv, i);
10890 tree init = DECL_INITIAL (DECL_EXPR_DECL (decl_expr));
10891 gcc_assert (init != NULL);
10892 TREE_VEC_ELT (initv, i) = RECUR (init);
10893 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = NULL;
10895 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = init;
10898 pre_body = push_stmt_list ();
10899 RECUR (OMP_FOR_PRE_BODY (t));
10900 pre_body = pop_stmt_list (pre_body);
10902 body = push_stmt_list ();
10903 RECUR (OMP_FOR_BODY (t));
10904 body = pop_stmt_list (body);
10906 t = finish_omp_for (EXPR_LOCATION (t), declv, initv, condv, incrv,
10907 body, pre_body, clauses);
10909 add_stmt (finish_omp_structured_block (stmt));
10915 tmp = tsubst_omp_clauses (OMP_CLAUSES (t), args, complain, in_decl);
10916 stmt = push_stmt_list ();
10917 RECUR (OMP_BODY (t));
10918 stmt = pop_stmt_list (stmt);
10921 OMP_BODY (t) = stmt;
10922 OMP_CLAUSES (t) = tmp;
10930 stmt = push_stmt_list ();
10931 RECUR (OMP_BODY (t));
10932 stmt = pop_stmt_list (stmt);
10935 OMP_BODY (t) = stmt;
10940 gcc_assert (OMP_ATOMIC_DEPENDENT_P (t));
10942 tree op1 = TREE_OPERAND (t, 1);
10943 tree lhs = RECUR (TREE_OPERAND (op1, 0));
10944 tree rhs = RECUR (TREE_OPERAND (op1, 1));
10945 finish_omp_atomic (TREE_CODE (op1), lhs, rhs);
10949 case EXPR_PACK_EXPANSION:
10950 error ("invalid use of pack expansion expression");
10951 return error_mark_node;
10953 case NONTYPE_ARGUMENT_PACK:
10954 error ("use %<...%> to expand argument pack");
10955 return error_mark_node;
10958 gcc_assert (!STATEMENT_CODE_P (TREE_CODE (t)));
10960 return tsubst_copy_and_build (t, args, complain, in_decl,
10961 /*function_p=*/false,
10962 integral_constant_expression_p);
10969 /* T is a postfix-expression that is not being used in a function
10970 call. Return the substituted version of T. */
10973 tsubst_non_call_postfix_expression (tree t, tree args,
10974 tsubst_flags_t complain,
10977 if (TREE_CODE (t) == SCOPE_REF)
10978 t = tsubst_qualified_id (t, args, complain, in_decl,
10979 /*done=*/false, /*address_p=*/false);
10981 t = tsubst_copy_and_build (t, args, complain, in_decl,
10982 /*function_p=*/false,
10983 /*integral_constant_expression_p=*/false);
10988 /* Like tsubst but deals with expressions and performs semantic
10989 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
10992 tsubst_copy_and_build (tree t,
10994 tsubst_flags_t complain,
10997 bool integral_constant_expression_p)
10999 #define RECUR(NODE) \
11000 tsubst_copy_and_build (NODE, args, complain, in_decl, \
11001 /*function_p=*/false, \
11002 integral_constant_expression_p)
11006 if (t == NULL_TREE || t == error_mark_node)
11009 switch (TREE_CODE (t))
11013 /* Fall through. */
11014 case IDENTIFIER_NODE:
11018 bool non_integral_constant_expression_p;
11019 const char *error_msg;
11021 if (IDENTIFIER_TYPENAME_P (t))
11023 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
11024 t = mangle_conv_op_name_for_type (new_type);
11027 /* Look up the name. */
11028 decl = lookup_name (t);
11030 /* By convention, expressions use ERROR_MARK_NODE to indicate
11031 failure, not NULL_TREE. */
11032 if (decl == NULL_TREE)
11033 decl = error_mark_node;
11035 decl = finish_id_expression (t, decl, NULL_TREE,
11037 integral_constant_expression_p,
11038 /*allow_non_integral_constant_expression_p=*/false,
11039 &non_integral_constant_expression_p,
11040 /*template_p=*/false,
11042 /*address_p=*/false,
11043 /*template_arg_p=*/false,
11048 if (!function_p && TREE_CODE (decl) == IDENTIFIER_NODE)
11049 decl = unqualified_name_lookup_error (decl);
11053 case TEMPLATE_ID_EXPR:
11056 tree templ = RECUR (TREE_OPERAND (t, 0));
11057 tree targs = TREE_OPERAND (t, 1);
11060 targs = tsubst_template_args (targs, args, complain, in_decl);
11062 if (TREE_CODE (templ) == COMPONENT_REF)
11064 object = TREE_OPERAND (templ, 0);
11065 templ = TREE_OPERAND (templ, 1);
11068 object = NULL_TREE;
11069 templ = lookup_template_function (templ, targs);
11072 return build3 (COMPONENT_REF, TREE_TYPE (templ),
11073 object, templ, NULL_TREE);
11075 return baselink_for_fns (templ);
11080 tree r = RECUR (TREE_OPERAND (t, 0));
11082 if (REFERENCE_REF_P (t))
11084 /* A type conversion to reference type will be enclosed in
11085 such an indirect ref, but the substitution of the cast
11086 will have also added such an indirect ref. */
11087 if (TREE_CODE (TREE_TYPE (r)) == REFERENCE_TYPE)
11088 r = convert_from_reference (r);
11091 r = build_x_indirect_ref (r, "unary *", complain);
11097 (tsubst (TREE_TYPE (t), args, complain, in_decl),
11098 RECUR (TREE_OPERAND (t, 0)));
11101 case REINTERPRET_CAST_EXPR:
11102 case CONST_CAST_EXPR:
11103 case DYNAMIC_CAST_EXPR:
11104 case STATIC_CAST_EXPR:
11109 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
11110 if (integral_constant_expression_p
11111 && !cast_valid_in_integral_constant_expression_p (type))
11113 if (complain & tf_error)
11114 error ("a cast to a type other than an integral or "
11115 "enumeration type cannot appear in a constant-expression");
11116 return error_mark_node;
11119 op = RECUR (TREE_OPERAND (t, 0));
11121 switch (TREE_CODE (t))
11124 return build_functional_cast (type, op, complain);
11125 case REINTERPRET_CAST_EXPR:
11126 return build_reinterpret_cast (type, op, complain);
11127 case CONST_CAST_EXPR:
11128 return build_const_cast (type, op, complain);
11129 case DYNAMIC_CAST_EXPR:
11130 return build_dynamic_cast (type, op, complain);
11131 case STATIC_CAST_EXPR:
11132 return build_static_cast (type, op, complain);
11134 gcc_unreachable ();
11138 case POSTDECREMENT_EXPR:
11139 case POSTINCREMENT_EXPR:
11140 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
11141 args, complain, in_decl);
11142 return build_x_unary_op (TREE_CODE (t), op1, complain);
11144 case PREDECREMENT_EXPR:
11145 case PREINCREMENT_EXPR:
11149 case TRUTH_NOT_EXPR:
11150 case UNARY_PLUS_EXPR: /* Unary + */
11151 case REALPART_EXPR:
11152 case IMAGPART_EXPR:
11153 return build_x_unary_op (TREE_CODE (t), RECUR (TREE_OPERAND (t, 0)),
11157 op1 = TREE_OPERAND (t, 0);
11158 if (TREE_CODE (op1) == SCOPE_REF)
11159 op1 = tsubst_qualified_id (op1, args, complain, in_decl,
11160 /*done=*/true, /*address_p=*/true);
11162 op1 = tsubst_non_call_postfix_expression (op1, args, complain,
11164 if (TREE_CODE (op1) == LABEL_DECL)
11165 return finish_label_address_expr (DECL_NAME (op1),
11166 EXPR_LOCATION (op1));
11167 return build_x_unary_op (ADDR_EXPR, op1, complain);
11172 case TRUNC_DIV_EXPR:
11173 case CEIL_DIV_EXPR:
11174 case FLOOR_DIV_EXPR:
11175 case ROUND_DIV_EXPR:
11176 case EXACT_DIV_EXPR:
11180 case TRUNC_MOD_EXPR:
11181 case FLOOR_MOD_EXPR:
11182 case TRUTH_ANDIF_EXPR:
11183 case TRUTH_ORIF_EXPR:
11184 case TRUTH_AND_EXPR:
11185 case TRUTH_OR_EXPR:
11200 return build_x_binary_op
11202 RECUR (TREE_OPERAND (t, 0)),
11203 (TREE_NO_WARNING (TREE_OPERAND (t, 0))
11205 : TREE_CODE (TREE_OPERAND (t, 0))),
11206 RECUR (TREE_OPERAND (t, 1)),
11207 (TREE_NO_WARNING (TREE_OPERAND (t, 1))
11209 : TREE_CODE (TREE_OPERAND (t, 1))),
11210 /*overloaded_p=*/NULL,
11214 return tsubst_qualified_id (t, args, complain, in_decl, /*done=*/true,
11215 /*address_p=*/false);
11217 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
11218 args, complain, in_decl);
11219 return build_x_binary_op (ARRAY_REF, op1,
11220 (TREE_NO_WARNING (TREE_OPERAND (t, 0))
11222 : TREE_CODE (TREE_OPERAND (t, 0))),
11223 RECUR (TREE_OPERAND (t, 1)),
11224 (TREE_NO_WARNING (TREE_OPERAND (t, 1))
11226 : TREE_CODE (TREE_OPERAND (t, 1))),
11227 /*overloaded_p=*/NULL,
11231 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
11232 return tsubst_copy (t, args, complain, in_decl);
11236 op1 = TREE_OPERAND (t, 0);
11239 /* When there are no ARGS, we are trying to evaluate a
11240 non-dependent expression from the parser. Trying to do
11241 the substitutions may not work. */
11243 op1 = TREE_TYPE (op1);
11248 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
11249 /*function_p=*/false,
11250 /*integral_constant_expression_p=*/false);
11254 return cxx_sizeof_or_alignof_type (op1, TREE_CODE (t),
11255 complain & tf_error);
11257 return cxx_sizeof_or_alignof_expr (op1, TREE_CODE (t),
11258 complain & tf_error);
11262 tree r = build_x_modify_expr
11263 (RECUR (TREE_OPERAND (t, 0)),
11264 TREE_CODE (TREE_OPERAND (t, 1)),
11265 RECUR (TREE_OPERAND (t, 2)),
11267 /* TREE_NO_WARNING must be set if either the expression was
11268 parenthesized or it uses an operator such as >>= rather
11269 than plain assignment. In the former case, it was already
11270 set and must be copied. In the latter case,
11271 build_x_modify_expr sets it and it must not be reset
11273 if (TREE_NO_WARNING (t))
11274 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
11279 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
11280 args, complain, in_decl);
11281 /* Remember that there was a reference to this entity. */
11284 return build_x_arrow (op1);
11288 tree init = RECUR (TREE_OPERAND (t, 3));
11290 if (TREE_OPERAND (t, 3) && !init)
11291 /* If there was an initializer in the original tree, but
11292 it instantiated to an empty list, then we should pass on
11293 VOID_ZERO_NODE to tell build_new that it was an empty
11294 initializer () rather than no initializer. This can only
11295 happen when the initializer is a pack expansion whose
11296 parameter packs are of length zero. */
11297 init = void_zero_node;
11300 (RECUR (TREE_OPERAND (t, 0)),
11301 RECUR (TREE_OPERAND (t, 1)),
11302 RECUR (TREE_OPERAND (t, 2)),
11304 NEW_EXPR_USE_GLOBAL (t),
11309 return delete_sanity
11310 (RECUR (TREE_OPERAND (t, 0)),
11311 RECUR (TREE_OPERAND (t, 1)),
11312 DELETE_EXPR_USE_VEC (t),
11313 DELETE_EXPR_USE_GLOBAL (t));
11315 case COMPOUND_EXPR:
11316 return build_x_compound_expr (RECUR (TREE_OPERAND (t, 0)),
11317 RECUR (TREE_OPERAND (t, 1)),
11327 function = CALL_EXPR_FN (t);
11328 /* When we parsed the expression, we determined whether or
11329 not Koenig lookup should be performed. */
11330 koenig_p = KOENIG_LOOKUP_P (t);
11331 if (TREE_CODE (function) == SCOPE_REF)
11333 qualified_p = true;
11334 function = tsubst_qualified_id (function, args, complain, in_decl,
11336 /*address_p=*/false);
11340 if (TREE_CODE (function) == COMPONENT_REF)
11342 tree op = TREE_OPERAND (function, 1);
11344 qualified_p = (TREE_CODE (op) == SCOPE_REF
11345 || (BASELINK_P (op)
11346 && BASELINK_QUALIFIED_P (op)));
11349 qualified_p = false;
11351 function = tsubst_copy_and_build (function, args, complain,
11354 integral_constant_expression_p);
11356 if (BASELINK_P (function))
11357 qualified_p = true;
11360 /* FIXME: Rewrite this so as not to construct an arglist. */
11361 call_args = RECUR (CALL_EXPR_ARGS (t));
11363 /* We do not perform argument-dependent lookup if normal
11364 lookup finds a non-function, in accordance with the
11365 expected resolution of DR 218. */
11367 && ((is_overloaded_fn (function)
11368 /* If lookup found a member function, the Koenig lookup is
11369 not appropriate, even if an unqualified-name was used
11370 to denote the function. */
11371 && !DECL_FUNCTION_MEMBER_P (get_first_fn (function)))
11372 || TREE_CODE (function) == IDENTIFIER_NODE))
11373 function = perform_koenig_lookup (function, call_args);
11375 if (TREE_CODE (function) == IDENTIFIER_NODE)
11377 unqualified_name_lookup_error (function);
11378 return error_mark_node;
11381 /* Remember that there was a reference to this entity. */
11382 if (DECL_P (function))
11383 mark_used (function);
11385 if (TREE_CODE (function) == OFFSET_REF)
11386 return build_offset_ref_call_from_tree (function, call_args);
11387 if (TREE_CODE (function) == COMPONENT_REF)
11389 if (!BASELINK_P (TREE_OPERAND (function, 1)))
11390 return finish_call_expr (function, call_args,
11391 /*disallow_virtual=*/false,
11392 /*koenig_p=*/false,
11395 return (build_new_method_call
11396 (TREE_OPERAND (function, 0),
11397 TREE_OPERAND (function, 1),
11398 call_args, NULL_TREE,
11399 qualified_p ? LOOKUP_NONVIRTUAL : LOOKUP_NORMAL,
11403 return finish_call_expr (function, call_args,
11404 /*disallow_virtual=*/qualified_p,
11410 return build_x_conditional_expr
11411 (RECUR (TREE_OPERAND (t, 0)),
11412 RECUR (TREE_OPERAND (t, 1)),
11413 RECUR (TREE_OPERAND (t, 2)),
11416 case PSEUDO_DTOR_EXPR:
11417 return finish_pseudo_destructor_expr
11418 (RECUR (TREE_OPERAND (t, 0)),
11419 RECUR (TREE_OPERAND (t, 1)),
11420 RECUR (TREE_OPERAND (t, 2)));
11424 tree purpose, value, chain;
11426 if (t == void_list_node)
11429 if ((TREE_PURPOSE (t) && PACK_EXPANSION_P (TREE_PURPOSE (t)))
11430 || (TREE_VALUE (t) && PACK_EXPANSION_P (TREE_VALUE (t))))
11432 /* We have pack expansions, so expand those and
11433 create a new list out of it. */
11434 tree purposevec = NULL_TREE;
11435 tree valuevec = NULL_TREE;
11439 /* Expand the argument expressions. */
11440 if (TREE_PURPOSE (t))
11441 purposevec = tsubst_pack_expansion (TREE_PURPOSE (t), args,
11442 complain, in_decl);
11443 if (TREE_VALUE (t))
11444 valuevec = tsubst_pack_expansion (TREE_VALUE (t), args,
11445 complain, in_decl);
11447 /* Build the rest of the list. */
11448 chain = TREE_CHAIN (t);
11449 if (chain && chain != void_type_node)
11450 chain = RECUR (chain);
11452 /* Determine the number of arguments. */
11453 if (purposevec && TREE_CODE (purposevec) == TREE_VEC)
11455 len = TREE_VEC_LENGTH (purposevec);
11456 gcc_assert (!valuevec || len == TREE_VEC_LENGTH (valuevec));
11458 else if (TREE_CODE (valuevec) == TREE_VEC)
11459 len = TREE_VEC_LENGTH (valuevec);
11462 /* Since we only performed a partial substitution into
11463 the argument pack, we only return a single list
11465 if (purposevec == TREE_PURPOSE (t)
11466 && valuevec == TREE_VALUE (t)
11467 && chain == TREE_CHAIN (t))
11470 return tree_cons (purposevec, valuevec, chain);
11473 /* Convert the argument vectors into a TREE_LIST */
11477 /* Grab the Ith values. */
11479 purpose = purposevec ? TREE_VEC_ELT (purposevec, i)
11482 = valuevec ? convert_from_reference (TREE_VEC_ELT (valuevec, i))
11485 /* Build the list (backwards). */
11486 chain = tree_cons (purpose, value, chain);
11492 purpose = TREE_PURPOSE (t);
11494 purpose = RECUR (purpose);
11495 value = TREE_VALUE (t);
11497 value = RECUR (value);
11498 chain = TREE_CHAIN (t);
11499 if (chain && chain != void_type_node)
11500 chain = RECUR (chain);
11501 if (purpose == TREE_PURPOSE (t)
11502 && value == TREE_VALUE (t)
11503 && chain == TREE_CHAIN (t))
11505 return tree_cons (purpose, value, chain);
11508 case COMPONENT_REF:
11514 object = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
11515 args, complain, in_decl);
11516 /* Remember that there was a reference to this entity. */
11517 if (DECL_P (object))
11518 mark_used (object);
11519 object_type = TREE_TYPE (object);
11521 member = TREE_OPERAND (t, 1);
11522 if (BASELINK_P (member))
11523 member = tsubst_baselink (member,
11524 non_reference (TREE_TYPE (object)),
11525 args, complain, in_decl);
11527 member = tsubst_copy (member, args, complain, in_decl);
11528 if (member == error_mark_node)
11529 return error_mark_node;
11531 if (object_type && !CLASS_TYPE_P (object_type))
11533 if (SCALAR_TYPE_P (object_type))
11535 tree s = NULL_TREE;
11536 tree dtor = member;
11538 if (TREE_CODE (dtor) == SCOPE_REF)
11540 s = TREE_OPERAND (dtor, 0);
11541 dtor = TREE_OPERAND (dtor, 1);
11543 if (TREE_CODE (dtor) == BIT_NOT_EXPR)
11545 dtor = TREE_OPERAND (dtor, 0);
11547 return finish_pseudo_destructor_expr (object, s, dtor);
11551 else if (TREE_CODE (member) == SCOPE_REF
11552 && TREE_CODE (TREE_OPERAND (member, 1)) == TEMPLATE_ID_EXPR)
11557 /* Lookup the template functions now that we know what the
11559 tmpl = TREE_OPERAND (TREE_OPERAND (member, 1), 0);
11560 args = TREE_OPERAND (TREE_OPERAND (member, 1), 1);
11561 member = lookup_qualified_name (TREE_OPERAND (member, 0), tmpl,
11562 /*is_type_p=*/false,
11563 /*complain=*/false);
11564 if (BASELINK_P (member))
11566 BASELINK_FUNCTIONS (member)
11567 = build_nt (TEMPLATE_ID_EXPR, BASELINK_FUNCTIONS (member),
11569 member = (adjust_result_of_qualified_name_lookup
11570 (member, BINFO_TYPE (BASELINK_BINFO (member)),
11575 qualified_name_lookup_error (object_type, tmpl, member,
11577 return error_mark_node;
11580 else if (TREE_CODE (member) == SCOPE_REF
11581 && !CLASS_TYPE_P (TREE_OPERAND (member, 0))
11582 && TREE_CODE (TREE_OPERAND (member, 0)) != NAMESPACE_DECL)
11584 if (complain & tf_error)
11586 if (TYPE_P (TREE_OPERAND (member, 0)))
11587 error ("%qT is not a class or namespace",
11588 TREE_OPERAND (member, 0));
11590 error ("%qD is not a class or namespace",
11591 TREE_OPERAND (member, 0));
11593 return error_mark_node;
11595 else if (TREE_CODE (member) == FIELD_DECL)
11596 return finish_non_static_data_member (member, object, NULL_TREE);
11598 return finish_class_member_access_expr (object, member,
11599 /*template_p=*/false,
11605 (RECUR (TREE_OPERAND (t, 0)));
11609 VEC(constructor_elt,gc) *n;
11610 constructor_elt *ce;
11611 unsigned HOST_WIDE_INT idx;
11612 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
11613 bool process_index_p;
11615 bool need_copy_p = false;
11618 if (type == error_mark_node)
11619 return error_mark_node;
11621 /* digest_init will do the wrong thing if we let it. */
11622 if (type && TYPE_PTRMEMFUNC_P (type))
11625 /* We do not want to process the index of aggregate
11626 initializers as they are identifier nodes which will be
11627 looked up by digest_init. */
11628 process_index_p = !(type && MAYBE_CLASS_TYPE_P (type));
11630 n = VEC_copy (constructor_elt, gc, CONSTRUCTOR_ELTS (t));
11631 newlen = VEC_length (constructor_elt, n);
11632 for (idx = 0; VEC_iterate (constructor_elt, n, idx, ce); idx++)
11634 if (ce->index && process_index_p)
11635 ce->index = RECUR (ce->index);
11637 if (PACK_EXPANSION_P (ce->value))
11639 /* Substitute into the pack expansion. */
11640 ce->value = tsubst_pack_expansion (ce->value, args, complain,
11643 if (ce->value == error_mark_node)
11645 else if (TREE_VEC_LENGTH (ce->value) == 1)
11646 /* Just move the argument into place. */
11647 ce->value = TREE_VEC_ELT (ce->value, 0);
11650 /* Update the length of the final CONSTRUCTOR
11651 arguments vector, and note that we will need to
11653 newlen = newlen + TREE_VEC_LENGTH (ce->value) - 1;
11654 need_copy_p = true;
11658 ce->value = RECUR (ce->value);
11663 VEC(constructor_elt,gc) *old_n = n;
11665 n = VEC_alloc (constructor_elt, gc, newlen);
11666 for (idx = 0; VEC_iterate (constructor_elt, old_n, idx, ce);
11669 if (TREE_CODE (ce->value) == TREE_VEC)
11671 int i, len = TREE_VEC_LENGTH (ce->value);
11672 for (i = 0; i < len; ++i)
11673 CONSTRUCTOR_APPEND_ELT (n, 0,
11674 TREE_VEC_ELT (ce->value, i));
11677 CONSTRUCTOR_APPEND_ELT (n, 0, ce->value);
11681 r = build_constructor (init_list_type_node, n);
11682 CONSTRUCTOR_IS_DIRECT_INIT (r) = CONSTRUCTOR_IS_DIRECT_INIT (t);
11684 if (TREE_HAS_CONSTRUCTOR (t))
11685 return finish_compound_literal (type, r);
11692 tree operand_0 = RECUR (TREE_OPERAND (t, 0));
11693 if (TYPE_P (operand_0))
11694 return get_typeid (operand_0);
11695 return build_typeid (operand_0);
11705 tree r = tsubst_copy (t, args, complain, in_decl);
11707 if (TREE_CODE (TREE_TYPE (t)) != REFERENCE_TYPE)
11708 /* If the original type was a reference, we'll be wrapped in
11709 the appropriate INDIRECT_REF. */
11710 r = convert_from_reference (r);
11715 return build_x_va_arg (RECUR (TREE_OPERAND (t, 0)),
11716 tsubst_copy (TREE_TYPE (t), args, complain,
11719 case OFFSETOF_EXPR:
11720 return finish_offsetof (RECUR (TREE_OPERAND (t, 0)));
11724 tree type1 = tsubst_copy (TRAIT_EXPR_TYPE1 (t), args,
11725 complain, in_decl);
11727 tree type2 = TRAIT_EXPR_TYPE2 (t);
11729 type2 = tsubst_copy (type2, args, complain, in_decl);
11731 return finish_trait_expr (TRAIT_EXPR_KIND (t), type1, type2);
11736 tree old_stmt_expr = cur_stmt_expr;
11737 tree stmt_expr = begin_stmt_expr ();
11739 cur_stmt_expr = stmt_expr;
11740 tsubst_expr (STMT_EXPR_STMT (t), args, complain, in_decl,
11741 integral_constant_expression_p);
11742 stmt_expr = finish_stmt_expr (stmt_expr, false);
11743 cur_stmt_expr = old_stmt_expr;
11749 t = tsubst_copy (t, args, complain, in_decl);
11750 /* As in finish_id_expression, we resolve enumeration constants
11751 to their underlying values. */
11752 if (TREE_CODE (t) == CONST_DECL)
11754 used_types_insert (TREE_TYPE (t));
11755 return DECL_INITIAL (t);
11760 /* Handle Objective-C++ constructs, if appropriate. */
11763 = objcp_tsubst_copy_and_build (t, args, complain,
11764 in_decl, /*function_p=*/false);
11768 return tsubst_copy (t, args, complain, in_decl);
11774 /* Verify that the instantiated ARGS are valid. For type arguments,
11775 make sure that the type's linkage is ok. For non-type arguments,
11776 make sure they are constants if they are integral or enumerations.
11777 Emit an error under control of COMPLAIN, and return TRUE on error. */
11780 check_instantiated_arg (tree tmpl, tree t, tsubst_flags_t complain)
11782 if (ARGUMENT_PACK_P (t))
11784 tree vec = ARGUMENT_PACK_ARGS (t);
11785 int len = TREE_VEC_LENGTH (vec);
11786 bool result = false;
11789 for (i = 0; i < len; ++i)
11790 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (vec, i), complain))
11794 else if (TYPE_P (t))
11796 /* [basic.link]: A name with no linkage (notably, the name
11797 of a class or enumeration declared in a local scope)
11798 shall not be used to declare an entity with linkage.
11799 This implies that names with no linkage cannot be used as
11800 template arguments. */
11801 tree nt = no_linkage_check (t, /*relaxed_p=*/false);
11805 /* DR 488 makes use of a type with no linkage cause
11806 type deduction to fail. */
11807 if (complain & tf_error)
11809 if (TYPE_ANONYMOUS_P (nt))
11810 error ("%qT is/uses anonymous type", t);
11812 error ("template argument for %qD uses local type %qT",
11817 /* In order to avoid all sorts of complications, we do not
11818 allow variably-modified types as template arguments. */
11819 else if (variably_modified_type_p (t, NULL_TREE))
11821 if (complain & tf_error)
11822 error ("%qT is a variably modified type", t);
11826 /* A non-type argument of integral or enumerated type must be a
11828 else if (TREE_TYPE (t)
11829 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t))
11830 && !TREE_CONSTANT (t))
11832 if (complain & tf_error)
11833 error ("integral expression %qE is not constant", t);
11840 check_instantiated_args (tree tmpl, tree args, tsubst_flags_t complain)
11842 int ix, len = DECL_NTPARMS (tmpl);
11843 bool result = false;
11845 for (ix = 0; ix != len; ix++)
11847 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (args, ix), complain))
11850 if (result && (complain & tf_error))
11851 error (" trying to instantiate %qD", tmpl);
11855 /* Instantiate the indicated variable or function template TMPL with
11856 the template arguments in TARG_PTR. */
11859 instantiate_template (tree tmpl, tree targ_ptr, tsubst_flags_t complain)
11864 HOST_WIDE_INT saved_processing_template_decl;
11866 if (tmpl == error_mark_node)
11867 return error_mark_node;
11869 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
11871 /* If this function is a clone, handle it specially. */
11872 if (DECL_CLONED_FUNCTION_P (tmpl))
11877 spec = instantiate_template (DECL_CLONED_FUNCTION (tmpl), targ_ptr,
11879 if (spec == error_mark_node)
11880 return error_mark_node;
11882 /* Look for the clone. */
11883 FOR_EACH_CLONE (clone, spec)
11884 if (DECL_NAME (clone) == DECL_NAME (tmpl))
11886 /* We should always have found the clone by now. */
11887 gcc_unreachable ();
11891 /* Check to see if we already have this specialization. */
11892 spec = retrieve_specialization (tmpl, targ_ptr,
11893 /*class_specializations_p=*/false);
11894 if (spec != NULL_TREE)
11897 gen_tmpl = most_general_template (tmpl);
11898 if (tmpl != gen_tmpl)
11900 /* The TMPL is a partial instantiation. To get a full set of
11901 arguments we must add the arguments used to perform the
11902 partial instantiation. */
11903 targ_ptr = add_outermost_template_args (DECL_TI_ARGS (tmpl),
11906 /* Check to see if we already have this specialization. */
11907 spec = retrieve_specialization (gen_tmpl, targ_ptr,
11908 /*class_specializations_p=*/false);
11909 if (spec != NULL_TREE)
11913 if (check_instantiated_args (gen_tmpl, INNERMOST_TEMPLATE_ARGS (targ_ptr),
11915 return error_mark_node;
11917 /* We are building a FUNCTION_DECL, during which the access of its
11918 parameters and return types have to be checked. However this
11919 FUNCTION_DECL which is the desired context for access checking
11920 is not built yet. We solve this chicken-and-egg problem by
11921 deferring all checks until we have the FUNCTION_DECL. */
11922 push_deferring_access_checks (dk_deferred);
11924 /* Although PROCESSING_TEMPLATE_DECL may be true at this point
11925 (because, for example, we have encountered a non-dependent
11926 function call in the body of a template function and must now
11927 determine which of several overloaded functions will be called),
11928 within the instantiation itself we are not processing a
11930 saved_processing_template_decl = processing_template_decl;
11931 processing_template_decl = 0;
11932 /* Substitute template parameters to obtain the specialization. */
11933 fndecl = tsubst (DECL_TEMPLATE_RESULT (gen_tmpl),
11934 targ_ptr, complain, gen_tmpl);
11935 processing_template_decl = saved_processing_template_decl;
11936 if (fndecl == error_mark_node)
11937 return error_mark_node;
11939 /* Now we know the specialization, compute access previously
11941 push_access_scope (fndecl);
11942 perform_deferred_access_checks ();
11943 pop_access_scope (fndecl);
11944 pop_deferring_access_checks ();
11946 /* The DECL_TI_TEMPLATE should always be the immediate parent
11947 template, not the most general template. */
11948 DECL_TI_TEMPLATE (fndecl) = tmpl;
11950 /* If we've just instantiated the main entry point for a function,
11951 instantiate all the alternate entry points as well. We do this
11952 by cloning the instantiation of the main entry point, not by
11953 instantiating the template clones. */
11954 if (TREE_CHAIN (gen_tmpl) && DECL_CLONED_FUNCTION_P (TREE_CHAIN (gen_tmpl)))
11955 clone_function_decl (fndecl, /*update_method_vec_p=*/0);
11960 /* The FN is a TEMPLATE_DECL for a function. The ARGS are the
11961 arguments that are being used when calling it. TARGS is a vector
11962 into which the deduced template arguments are placed.
11964 Return zero for success, 2 for an incomplete match that doesn't resolve
11965 all the types, and 1 for complete failure. An error message will be
11966 printed only for an incomplete match.
11968 If FN is a conversion operator, or we are trying to produce a specific
11969 specialization, RETURN_TYPE is the return type desired.
11971 The EXPLICIT_TARGS are explicit template arguments provided via a
11974 The parameter STRICT is one of:
11977 We are deducing arguments for a function call, as in
11978 [temp.deduct.call].
11981 We are deducing arguments for a conversion function, as in
11982 [temp.deduct.conv].
11985 We are deducing arguments when doing an explicit instantiation
11986 as in [temp.explicit], when determining an explicit specialization
11987 as in [temp.expl.spec], or when taking the address of a function
11988 template, as in [temp.deduct.funcaddr]. */
11991 fn_type_unification (tree fn,
11992 tree explicit_targs,
11996 unification_kind_t strict,
12002 bool incomplete_argument_packs_p = false;
12004 gcc_assert (TREE_CODE (fn) == TEMPLATE_DECL);
12006 fntype = TREE_TYPE (fn);
12007 if (explicit_targs)
12011 The specified template arguments must match the template
12012 parameters in kind (i.e., type, nontype, template), and there
12013 must not be more arguments than there are parameters;
12014 otherwise type deduction fails.
12016 Nontype arguments must match the types of the corresponding
12017 nontype template parameters, or must be convertible to the
12018 types of the corresponding nontype parameters as specified in
12019 _temp.arg.nontype_, otherwise type deduction fails.
12021 All references in the function type of the function template
12022 to the corresponding template parameters are replaced by the
12023 specified template argument values. If a substitution in a
12024 template parameter or in the function type of the function
12025 template results in an invalid type, type deduction fails. */
12026 tree tparms = DECL_INNERMOST_TEMPLATE_PARMS (fn);
12027 int i, len = TREE_VEC_LENGTH (tparms);
12028 tree converted_args;
12029 bool incomplete = false;
12031 if (explicit_targs == error_mark_node)
12035 = (coerce_template_parms (tparms, explicit_targs, NULL_TREE, tf_none,
12036 /*require_all_args=*/false,
12037 /*use_default_args=*/false));
12038 if (converted_args == error_mark_node)
12041 /* Substitute the explicit args into the function type. This is
12042 necessary so that, for instance, explicitly declared function
12043 arguments can match null pointed constants. If we were given
12044 an incomplete set of explicit args, we must not do semantic
12045 processing during substitution as we could create partial
12047 for (i = 0; i < len; i++)
12049 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
12050 bool parameter_pack = false;
12052 /* Dig out the actual parm. */
12053 if (TREE_CODE (parm) == TYPE_DECL
12054 || TREE_CODE (parm) == TEMPLATE_DECL)
12056 parm = TREE_TYPE (parm);
12057 parameter_pack = TEMPLATE_TYPE_PARAMETER_PACK (parm);
12059 else if (TREE_CODE (parm) == PARM_DECL)
12061 parm = DECL_INITIAL (parm);
12062 parameter_pack = TEMPLATE_PARM_PARAMETER_PACK (parm);
12065 if (parameter_pack)
12069 template_parm_level_and_index (parm, &level, &idx);
12071 /* Mark the argument pack as "incomplete". We could
12072 still deduce more arguments during unification. */
12073 targ = TMPL_ARG (converted_args, level, idx);
12076 ARGUMENT_PACK_INCOMPLETE_P(targ) = 1;
12077 ARGUMENT_PACK_EXPLICIT_ARGS (targ)
12078 = ARGUMENT_PACK_ARGS (targ);
12081 /* We have some incomplete argument packs. */
12082 incomplete_argument_packs_p = true;
12086 if (incomplete_argument_packs_p)
12087 /* Any substitution is guaranteed to be incomplete if there
12088 are incomplete argument packs, because we can still deduce
12092 incomplete = NUM_TMPL_ARGS (explicit_targs) != NUM_TMPL_ARGS (targs);
12094 processing_template_decl += incomplete;
12095 fntype = tsubst (fntype, converted_args, tf_none, NULL_TREE);
12096 processing_template_decl -= incomplete;
12098 if (fntype == error_mark_node)
12101 /* Place the explicitly specified arguments in TARGS. */
12102 for (i = NUM_TMPL_ARGS (converted_args); i--;)
12103 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (converted_args, i);
12106 /* Never do unification on the 'this' parameter. */
12107 parms = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (fntype));
12111 parms = tree_cons (NULL_TREE, TREE_TYPE (fntype), parms);
12112 args = tree_cons (NULL_TREE, return_type, args);
12115 /* We allow incomplete unification without an error message here
12116 because the standard doesn't seem to explicitly prohibit it. Our
12117 callers must be ready to deal with unification failures in any
12119 result = type_unification_real (DECL_INNERMOST_TEMPLATE_PARMS (fn),
12120 targs, parms, args, /*subr=*/0,
12123 if (result == 0 && incomplete_argument_packs_p)
12125 int i, len = NUM_TMPL_ARGS (targs);
12127 /* Clear the "incomplete" flags on all argument packs. */
12128 for (i = 0; i < len; i++)
12130 tree arg = TREE_VEC_ELT (targs, i);
12131 if (ARGUMENT_PACK_P (arg))
12133 ARGUMENT_PACK_INCOMPLETE_P (arg) = 0;
12134 ARGUMENT_PACK_EXPLICIT_ARGS (arg) = NULL_TREE;
12139 /* Now that we have bindings for all of the template arguments,
12140 ensure that the arguments deduced for the template template
12141 parameters have compatible template parameter lists. We cannot
12142 check this property before we have deduced all template
12143 arguments, because the template parameter types of a template
12144 template parameter might depend on prior template parameters
12145 deduced after the template template parameter. The following
12146 ill-formed example illustrates this issue:
12148 template<typename T, template<T> class C> void f(C<5>, T);
12150 template<int N> struct X {};
12153 f(X<5>(), 5l); // error: template argument deduction fails
12156 The template parameter list of 'C' depends on the template type
12157 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
12158 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
12159 time that we deduce 'C'. */
12161 && !template_template_parm_bindings_ok_p
12162 (DECL_INNERMOST_TEMPLATE_PARMS (fn), targs))
12166 /* All is well so far. Now, check:
12170 When all template arguments have been deduced, all uses of
12171 template parameters in nondeduced contexts are replaced with
12172 the corresponding deduced argument values. If the
12173 substitution results in an invalid type, as described above,
12174 type deduction fails. */
12175 if (tsubst (TREE_TYPE (fn), targs, tf_none, NULL_TREE)
12176 == error_mark_node)
12182 /* Adjust types before performing type deduction, as described in
12183 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
12184 sections are symmetric. PARM is the type of a function parameter
12185 or the return type of the conversion function. ARG is the type of
12186 the argument passed to the call, or the type of the value
12187 initialized with the result of the conversion function.
12188 ARG_EXPR is the original argument expression, which may be null. */
12191 maybe_adjust_types_for_deduction (unification_kind_t strict,
12205 /* Swap PARM and ARG throughout the remainder of this
12206 function; the handling is precisely symmetric since PARM
12207 will initialize ARG rather than vice versa. */
12215 /* There is nothing to do in this case. */
12219 gcc_unreachable ();
12222 if (TREE_CODE (*parm) != REFERENCE_TYPE)
12224 /* [temp.deduct.call]
12226 If P is not a reference type:
12228 --If A is an array type, the pointer type produced by the
12229 array-to-pointer standard conversion (_conv.array_) is
12230 used in place of A for type deduction; otherwise,
12232 --If A is a function type, the pointer type produced by
12233 the function-to-pointer standard conversion
12234 (_conv.func_) is used in place of A for type deduction;
12237 --If A is a cv-qualified type, the top level
12238 cv-qualifiers of A's type are ignored for type
12240 if (TREE_CODE (*arg) == ARRAY_TYPE)
12241 *arg = build_pointer_type (TREE_TYPE (*arg));
12242 else if (TREE_CODE (*arg) == FUNCTION_TYPE)
12243 *arg = build_pointer_type (*arg);
12245 *arg = TYPE_MAIN_VARIANT (*arg);
12248 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
12249 of the form T&&, where T is a template parameter, and the argument
12250 is an lvalue, T is deduced as A& */
12251 if (TREE_CODE (*parm) == REFERENCE_TYPE
12252 && TYPE_REF_IS_RVALUE (*parm)
12253 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
12254 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
12255 && arg_expr && real_lvalue_p (arg_expr))
12256 *arg = build_reference_type (*arg);
12258 /* [temp.deduct.call]
12260 If P is a cv-qualified type, the top level cv-qualifiers
12261 of P's type are ignored for type deduction. If P is a
12262 reference type, the type referred to by P is used for
12264 *parm = TYPE_MAIN_VARIANT (*parm);
12265 if (TREE_CODE (*parm) == REFERENCE_TYPE)
12267 *parm = TREE_TYPE (*parm);
12268 result |= UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
12271 /* DR 322. For conversion deduction, remove a reference type on parm
12272 too (which has been swapped into ARG). */
12273 if (strict == DEDUCE_CONV && TREE_CODE (*arg) == REFERENCE_TYPE)
12274 *arg = TREE_TYPE (*arg);
12279 /* Most parms like fn_type_unification.
12281 If SUBR is 1, we're being called recursively (to unify the
12282 arguments of a function or method parameter of a function
12286 type_unification_real (tree tparms,
12291 unification_kind_t strict,
12294 tree parm, arg, arg_expr;
12296 int ntparms = TREE_VEC_LENGTH (tparms);
12298 int saw_undeduced = 0;
12301 gcc_assert (TREE_CODE (tparms) == TREE_VEC);
12302 gcc_assert (xparms == NULL_TREE || TREE_CODE (xparms) == TREE_LIST);
12303 gcc_assert (!xargs || TREE_CODE (xargs) == TREE_LIST);
12304 gcc_assert (ntparms > 0);
12309 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL | UNIFY_ALLOW_MORE_CV_QUAL
12310 | UNIFY_ALLOW_DERIVED);
12314 sub_strict = UNIFY_ALLOW_LESS_CV_QUAL;
12318 sub_strict = UNIFY_ALLOW_NONE;
12322 gcc_unreachable ();
12329 while (parms && parms != void_list_node
12330 && args && args != void_list_node)
12332 if (TREE_CODE (TREE_VALUE (parms)) == TYPE_PACK_EXPANSION)
12335 parm = TREE_VALUE (parms);
12336 parms = TREE_CHAIN (parms);
12337 arg = TREE_VALUE (args);
12338 args = TREE_CHAIN (args);
12341 if (arg == error_mark_node)
12343 if (arg == unknown_type_node)
12344 /* We can't deduce anything from this, but we might get all the
12345 template args from other function args. */
12348 /* Conversions will be performed on a function argument that
12349 corresponds with a function parameter that contains only
12350 non-deducible template parameters and explicitly specified
12351 template parameters. */
12352 if (!uses_template_parms (parm))
12357 type = TREE_TYPE (arg);
12361 if (same_type_p (parm, type))
12363 if (strict != DEDUCE_EXACT
12364 && can_convert_arg (parm, type, TYPE_P (arg) ? NULL_TREE : arg,
12373 gcc_assert (TREE_TYPE (arg) != NULL_TREE);
12374 if (type_unknown_p (arg))
12376 /* [temp.deduct.type]
12378 A template-argument can be deduced from a pointer to
12379 function or pointer to member function argument if
12380 the set of overloaded functions does not contain
12381 function templates and at most one of a set of
12382 overloaded functions provides a unique match. */
12383 if (resolve_overloaded_unification
12384 (tparms, targs, parm, arg, strict, sub_strict))
12390 arg = unlowered_expr_type (arg);
12391 if (arg == error_mark_node)
12396 int arg_strict = sub_strict;
12399 arg_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg,
12402 if (arg == init_list_type_node && arg_expr)
12404 if (unify (tparms, targs, parm, arg, arg_strict))
12411 && parms != void_list_node
12412 && TREE_CODE (TREE_VALUE (parms)) == TYPE_PACK_EXPANSION)
12414 /* Unify the remaining arguments with the pack expansion type. */
12416 tree parmvec = make_tree_vec (1);
12420 /* Count the number of arguments that remain. */
12421 for (t = args; t && t != void_list_node; t = TREE_CHAIN (t))
12424 /* Allocate a TREE_VEC and copy in all of the arguments */
12425 argvec = make_tree_vec (len);
12426 for (i = 0; args && args != void_list_node; args = TREE_CHAIN (args))
12428 TREE_VEC_ELT (argvec, i) = TREE_VALUE (args);
12432 /* Copy the parameter into parmvec. */
12433 TREE_VEC_ELT (parmvec, 0) = TREE_VALUE (parms);
12434 if (unify_pack_expansion (tparms, targs, parmvec, argvec, strict,
12435 /*call_args_p=*/true, /*subr=*/subr))
12438 /* Advance to the end of the list of parameters. */
12439 parms = TREE_CHAIN (parms);
12442 /* Fail if we've reached the end of the parm list, and more args
12443 are present, and the parm list isn't variadic. */
12444 if (args && args != void_list_node && parms == void_list_node)
12446 /* Fail if parms are left and they don't have default values. */
12447 if (parms && parms != void_list_node
12448 && TREE_PURPOSE (parms) == NULL_TREE)
12452 for (i = 0; i < ntparms; i++)
12453 if (!TREE_VEC_ELT (targs, i))
12457 if (TREE_VEC_ELT (tparms, i) == error_mark_node)
12460 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
12462 /* If this is an undeduced nontype parameter that depends on
12463 a type parameter, try another pass; its type may have been
12464 deduced from a later argument than the one from which
12465 this parameter can be deduced. */
12466 if (TREE_CODE (tparm) == PARM_DECL
12467 && uses_template_parms (TREE_TYPE (tparm))
12468 && !saw_undeduced++)
12471 /* Core issue #226 (C++0x) [temp.deduct]:
12473 If a template argument has not been deduced, its
12474 default template argument, if any, is used.
12476 When we are in C++98 mode, TREE_PURPOSE will either
12477 be NULL_TREE or ERROR_MARK_NODE, so we do not need
12478 to explicitly check cxx_dialect here. */
12479 if (TREE_PURPOSE (TREE_VEC_ELT (tparms, i)))
12481 tree arg = tsubst (TREE_PURPOSE (TREE_VEC_ELT (tparms, i)),
12482 targs, tf_none, NULL_TREE);
12483 if (arg == error_mark_node)
12487 TREE_VEC_ELT (targs, i) = arg;
12492 /* If the type parameter is a parameter pack, then it will
12493 be deduced to an empty parameter pack. */
12494 if (template_parameter_pack_p (tparm))
12498 if (TREE_CODE (tparm) == TEMPLATE_PARM_INDEX)
12500 arg = make_node (NONTYPE_ARGUMENT_PACK);
12501 TREE_TYPE (arg) = TREE_TYPE (TEMPLATE_PARM_DECL (tparm));
12502 TREE_CONSTANT (arg) = 1;
12505 arg = make_node (TYPE_ARGUMENT_PACK);
12507 SET_ARGUMENT_PACK_ARGS (arg, make_tree_vec (0));
12509 TREE_VEC_ELT (targs, i) = arg;
12519 /* Subroutine of type_unification_real. Args are like the variables
12520 at the call site. ARG is an overloaded function (or template-id);
12521 we try deducing template args from each of the overloads, and if
12522 only one succeeds, we go with that. Modifies TARGS and returns
12523 true on success. */
12526 resolve_overloaded_unification (tree tparms,
12530 unification_kind_t strict,
12533 tree tempargs = copy_node (targs);
12537 if (TREE_CODE (arg) == ADDR_EXPR)
12539 arg = TREE_OPERAND (arg, 0);
12545 if (TREE_CODE (arg) == COMPONENT_REF)
12546 /* Handle `&x' where `x' is some static or non-static member
12548 arg = TREE_OPERAND (arg, 1);
12550 if (TREE_CODE (arg) == OFFSET_REF)
12551 arg = TREE_OPERAND (arg, 1);
12553 /* Strip baselink information. */
12554 if (BASELINK_P (arg))
12555 arg = BASELINK_FUNCTIONS (arg);
12557 if (TREE_CODE (arg) == TEMPLATE_ID_EXPR)
12559 /* If we got some explicit template args, we need to plug them into
12560 the affected templates before we try to unify, in case the
12561 explicit args will completely resolve the templates in question. */
12563 tree expl_subargs = TREE_OPERAND (arg, 1);
12564 arg = TREE_OPERAND (arg, 0);
12566 for (; arg; arg = OVL_NEXT (arg))
12568 tree fn = OVL_CURRENT (arg);
12569 tree subargs, elem;
12571 if (TREE_CODE (fn) != TEMPLATE_DECL)
12574 ++processing_template_decl;
12575 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
12576 expl_subargs, /*check_ret=*/false);
12579 elem = tsubst (TREE_TYPE (fn), subargs, tf_none, NULL_TREE);
12580 good += try_one_overload (tparms, targs, tempargs, parm,
12581 elem, strict, sub_strict, addr_p);
12583 --processing_template_decl;
12586 else if (TREE_CODE (arg) != OVERLOAD
12587 && TREE_CODE (arg) != FUNCTION_DECL)
12588 /* If ARG is, for example, "(0, &f)" then its type will be unknown
12589 -- but the deduction does not succeed because the expression is
12590 not just the function on its own. */
12593 for (; arg; arg = OVL_NEXT (arg))
12594 good += try_one_overload (tparms, targs, tempargs, parm,
12595 TREE_TYPE (OVL_CURRENT (arg)),
12596 strict, sub_strict, addr_p);
12598 /* [temp.deduct.type] A template-argument can be deduced from a pointer
12599 to function or pointer to member function argument if the set of
12600 overloaded functions does not contain function templates and at most
12601 one of a set of overloaded functions provides a unique match.
12603 So if we found multiple possibilities, we return success but don't
12604 deduce anything. */
12608 int i = TREE_VEC_LENGTH (targs);
12610 if (TREE_VEC_ELT (tempargs, i))
12611 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (tempargs, i);
12619 /* Subroutine of resolve_overloaded_unification; does deduction for a single
12620 overload. Fills TARGS with any deduced arguments, or error_mark_node if
12621 different overloads deduce different arguments for a given parm.
12622 ADDR_P is true if the expression for which deduction is being
12623 performed was of the form "& fn" rather than simply "fn".
12625 Returns 1 on success. */
12628 try_one_overload (tree tparms,
12633 unification_kind_t strict,
12641 /* [temp.deduct.type] A template-argument can be deduced from a pointer
12642 to function or pointer to member function argument if the set of
12643 overloaded functions does not contain function templates and at most
12644 one of a set of overloaded functions provides a unique match.
12646 So if this is a template, just return success. */
12648 if (uses_template_parms (arg))
12651 if (TREE_CODE (arg) == METHOD_TYPE)
12652 arg = build_ptrmemfunc_type (build_pointer_type (arg));
12654 arg = build_pointer_type (arg);
12656 sub_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg, NULL);
12658 /* We don't copy orig_targs for this because if we have already deduced
12659 some template args from previous args, unify would complain when we
12660 try to deduce a template parameter for the same argument, even though
12661 there isn't really a conflict. */
12662 nargs = TREE_VEC_LENGTH (targs);
12663 tempargs = make_tree_vec (nargs);
12665 if (unify (tparms, tempargs, parm, arg, sub_strict) != 0)
12668 /* First make sure we didn't deduce anything that conflicts with
12669 explicitly specified args. */
12670 for (i = nargs; i--; )
12672 tree elt = TREE_VEC_ELT (tempargs, i);
12673 tree oldelt = TREE_VEC_ELT (orig_targs, i);
12677 else if (uses_template_parms (elt))
12678 /* Since we're unifying against ourselves, we will fill in
12679 template args used in the function parm list with our own
12680 template parms. Discard them. */
12681 TREE_VEC_ELT (tempargs, i) = NULL_TREE;
12682 else if (oldelt && !template_args_equal (oldelt, elt))
12686 for (i = nargs; i--; )
12688 tree elt = TREE_VEC_ELT (tempargs, i);
12691 TREE_VEC_ELT (targs, i) = elt;
12697 /* PARM is a template class (perhaps with unbound template
12698 parameters). ARG is a fully instantiated type. If ARG can be
12699 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
12700 TARGS are as for unify. */
12703 try_class_unification (tree tparms, tree targs, tree parm, tree arg)
12705 tree copy_of_targs;
12707 if (!CLASSTYPE_TEMPLATE_INFO (arg)
12708 || (most_general_template (CLASSTYPE_TI_TEMPLATE (arg))
12709 != most_general_template (CLASSTYPE_TI_TEMPLATE (parm))))
12712 /* We need to make a new template argument vector for the call to
12713 unify. If we used TARGS, we'd clutter it up with the result of
12714 the attempted unification, even if this class didn't work out.
12715 We also don't want to commit ourselves to all the unifications
12716 we've already done, since unification is supposed to be done on
12717 an argument-by-argument basis. In other words, consider the
12718 following pathological case:
12720 template <int I, int J, int K>
12723 template <int I, int J>
12724 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
12726 template <int I, int J, int K>
12727 void f(S<I, J, K>, S<I, I, I>);
12736 Now, by the time we consider the unification involving `s2', we
12737 already know that we must have `f<0, 0, 0>'. But, even though
12738 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
12739 because there are two ways to unify base classes of S<0, 1, 2>
12740 with S<I, I, I>. If we kept the already deduced knowledge, we
12741 would reject the possibility I=1. */
12742 copy_of_targs = make_tree_vec (TREE_VEC_LENGTH (targs));
12744 /* If unification failed, we're done. */
12745 if (unify (tparms, copy_of_targs, CLASSTYPE_TI_ARGS (parm),
12746 CLASSTYPE_TI_ARGS (arg), UNIFY_ALLOW_NONE))
12752 /* Given a template type PARM and a class type ARG, find the unique
12753 base type in ARG that is an instance of PARM. We do not examine
12754 ARG itself; only its base-classes. If there is not exactly one
12755 appropriate base class, return NULL_TREE. PARM may be the type of
12756 a partial specialization, as well as a plain template type. Used
12760 get_template_base (tree tparms, tree targs, tree parm, tree arg)
12762 tree rval = NULL_TREE;
12765 gcc_assert (RECORD_OR_UNION_CODE_P (TREE_CODE (arg)));
12767 binfo = TYPE_BINFO (complete_type (arg));
12769 /* The type could not be completed. */
12772 /* Walk in inheritance graph order. The search order is not
12773 important, and this avoids multiple walks of virtual bases. */
12774 for (binfo = TREE_CHAIN (binfo); binfo; binfo = TREE_CHAIN (binfo))
12776 tree r = try_class_unification (tparms, targs, parm, BINFO_TYPE (binfo));
12780 /* If there is more than one satisfactory baseclass, then:
12784 If they yield more than one possible deduced A, the type
12788 if (rval && !same_type_p (r, rval))
12798 /* Returns the level of DECL, which declares a template parameter. */
12801 template_decl_level (tree decl)
12803 switch (TREE_CODE (decl))
12806 case TEMPLATE_DECL:
12807 return TEMPLATE_TYPE_LEVEL (TREE_TYPE (decl));
12810 return TEMPLATE_PARM_LEVEL (DECL_INITIAL (decl));
12813 gcc_unreachable ();
12818 /* Decide whether ARG can be unified with PARM, considering only the
12819 cv-qualifiers of each type, given STRICT as documented for unify.
12820 Returns nonzero iff the unification is OK on that basis. */
12823 check_cv_quals_for_unify (int strict, tree arg, tree parm)
12825 int arg_quals = cp_type_quals (arg);
12826 int parm_quals = cp_type_quals (parm);
12828 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
12829 && !(strict & UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
12831 /* Although a CVR qualifier is ignored when being applied to a
12832 substituted template parameter ([8.3.2]/1 for example), that
12833 does not apply during deduction [14.8.2.4]/1, (even though
12834 that is not explicitly mentioned, [14.8.2.4]/9 indicates
12835 this). Except when we're allowing additional CV qualifiers
12836 at the outer level [14.8.2.1]/3,1st bullet. */
12837 if ((TREE_CODE (arg) == REFERENCE_TYPE
12838 || TREE_CODE (arg) == FUNCTION_TYPE
12839 || TREE_CODE (arg) == METHOD_TYPE)
12840 && (parm_quals & (TYPE_QUAL_CONST | TYPE_QUAL_VOLATILE)))
12843 if ((!POINTER_TYPE_P (arg) && TREE_CODE (arg) != TEMPLATE_TYPE_PARM)
12844 && (parm_quals & TYPE_QUAL_RESTRICT))
12848 if (!(strict & (UNIFY_ALLOW_MORE_CV_QUAL | UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
12849 && (arg_quals & parm_quals) != parm_quals)
12852 if (!(strict & (UNIFY_ALLOW_LESS_CV_QUAL | UNIFY_ALLOW_OUTER_LESS_CV_QUAL))
12853 && (parm_quals & arg_quals) != arg_quals)
12859 /* Determines the LEVEL and INDEX for the template parameter PARM. */
12861 template_parm_level_and_index (tree parm, int* level, int* index)
12863 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
12864 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
12865 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
12867 *index = TEMPLATE_TYPE_IDX (parm);
12868 *level = TEMPLATE_TYPE_LEVEL (parm);
12872 *index = TEMPLATE_PARM_IDX (parm);
12873 *level = TEMPLATE_PARM_LEVEL (parm);
12877 /* Unifies the remaining arguments in PACKED_ARGS with the pack
12878 expansion at the end of PACKED_PARMS. Returns 0 if the type
12879 deduction succeeds, 1 otherwise. STRICT is the same as in
12880 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
12881 call argument list. We'll need to adjust the arguments to make them
12882 types. SUBR tells us if this is from a recursive call to
12883 type_unification_real. */
12885 unify_pack_expansion (tree tparms, tree targs, tree packed_parms,
12886 tree packed_args, int strict, bool call_args_p,
12890 = TREE_VEC_ELT (packed_parms, TREE_VEC_LENGTH (packed_parms) - 1);
12891 tree pattern = PACK_EXPANSION_PATTERN (parm);
12892 tree pack, packs = NULL_TREE;
12893 int i, start = TREE_VEC_LENGTH (packed_parms) - 1;
12894 int len = TREE_VEC_LENGTH (packed_args);
12896 /* Determine the parameter packs we will be deducing from the
12897 pattern, and record their current deductions. */
12898 for (pack = PACK_EXPANSION_PARAMETER_PACKS (parm);
12899 pack; pack = TREE_CHAIN (pack))
12901 tree parm_pack = TREE_VALUE (pack);
12904 /* Determine the index and level of this parameter pack. */
12905 template_parm_level_and_index (parm_pack, &level, &idx);
12907 /* Keep track of the parameter packs and their corresponding
12909 packs = tree_cons (parm_pack, TMPL_ARG (targs, level, idx), packs);
12910 TREE_TYPE (packs) = make_tree_vec (len - start);
12913 /* Loop through all of the arguments that have not yet been
12914 unified and unify each with the pattern. */
12915 for (i = start; i < len; i++)
12917 tree parm = pattern;
12919 /* For each parameter pack, clear out the deduced value so that
12920 we can deduce it again. */
12921 for (pack = packs; pack; pack = TREE_CHAIN (pack))
12924 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
12926 TMPL_ARG (targs, level, idx) = NULL_TREE;
12929 /* Unify the pattern with the current argument. */
12931 tree arg = TREE_VEC_ELT (packed_args, i);
12932 tree arg_expr = NULL_TREE;
12933 int arg_strict = strict;
12934 bool skip_arg_p = false;
12940 /* This mirrors what we do in type_unification_real. */
12944 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL
12945 | UNIFY_ALLOW_MORE_CV_QUAL
12946 | UNIFY_ALLOW_DERIVED);
12950 sub_strict = UNIFY_ALLOW_LESS_CV_QUAL;
12954 sub_strict = UNIFY_ALLOW_NONE;
12958 gcc_unreachable ();
12963 gcc_assert (TREE_TYPE (arg) != NULL_TREE);
12964 if (type_unknown_p (arg))
12966 /* [temp.deduct.type] A template-argument can be
12967 deduced from a pointer to function or pointer
12968 to member function argument if the set of
12969 overloaded functions does not contain function
12970 templates and at most one of a set of
12971 overloaded functions provides a unique
12974 if (resolve_overloaded_unification
12975 (tparms, targs, parm, arg, strict, sub_strict)
12984 arg = unlowered_expr_type (arg);
12985 if (arg == error_mark_node)
12990 arg_strict = sub_strict;
12994 maybe_adjust_types_for_deduction (strict, &parm, &arg,
13000 if (unify (tparms, targs, parm, arg, arg_strict))
13005 /* For each parameter pack, collect the deduced value. */
13006 for (pack = packs; pack; pack = TREE_CHAIN (pack))
13009 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
13011 TREE_VEC_ELT (TREE_TYPE (pack), i - start) =
13012 TMPL_ARG (targs, level, idx);
13016 /* Verify that the results of unification with the parameter packs
13017 produce results consistent with what we've seen before, and make
13018 the deduced argument packs available. */
13019 for (pack = packs; pack; pack = TREE_CHAIN (pack))
13021 tree old_pack = TREE_VALUE (pack);
13022 tree new_args = TREE_TYPE (pack);
13023 int i, len = TREE_VEC_LENGTH (new_args);
13024 bool nondeduced_p = false;
13026 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
13027 actually deduce anything. */
13028 for (i = 0; i < len && !nondeduced_p; ++i)
13029 if (TREE_VEC_ELT (new_args, i) == NULL_TREE)
13030 nondeduced_p = true;
13034 if (old_pack && ARGUMENT_PACK_INCOMPLETE_P (old_pack))
13036 /* Prepend the explicit arguments onto NEW_ARGS. */
13037 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
13038 tree old_args = new_args;
13039 int i, explicit_len = TREE_VEC_LENGTH (explicit_args);
13040 int len = explicit_len + TREE_VEC_LENGTH (old_args);
13042 /* Copy the explicit arguments. */
13043 new_args = make_tree_vec (len);
13044 for (i = 0; i < explicit_len; i++)
13045 TREE_VEC_ELT (new_args, i) = TREE_VEC_ELT (explicit_args, i);
13047 /* Copy the deduced arguments. */
13048 for (; i < len; i++)
13049 TREE_VEC_ELT (new_args, i) =
13050 TREE_VEC_ELT (old_args, i - explicit_len);
13058 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
13060 /* Build the deduced *_ARGUMENT_PACK. */
13061 if (TREE_CODE (TREE_PURPOSE (pack)) == TEMPLATE_PARM_INDEX)
13063 result = make_node (NONTYPE_ARGUMENT_PACK);
13064 TREE_TYPE (result) =
13065 TREE_TYPE (TEMPLATE_PARM_DECL (TREE_PURPOSE (pack)));
13066 TREE_CONSTANT (result) = 1;
13069 result = make_node (TYPE_ARGUMENT_PACK);
13071 SET_ARGUMENT_PACK_ARGS (result, new_args);
13073 /* Note the deduced argument packs for this parameter
13075 TMPL_ARG (targs, level, idx) = result;
13077 else if (ARGUMENT_PACK_INCOMPLETE_P (old_pack)
13078 && (ARGUMENT_PACK_ARGS (old_pack)
13079 == ARGUMENT_PACK_EXPLICIT_ARGS (old_pack)))
13081 /* We only had the explicitly-provided arguments before, but
13082 now we have a complete set of arguments. */
13084 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
13085 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
13087 /* Keep the original deduced argument pack. */
13088 TMPL_ARG (targs, level, idx) = old_pack;
13090 SET_ARGUMENT_PACK_ARGS (old_pack, new_args);
13091 ARGUMENT_PACK_INCOMPLETE_P (old_pack) = 1;
13092 ARGUMENT_PACK_EXPLICIT_ARGS (old_pack) = explicit_args;
13094 else if (!comp_template_args (ARGUMENT_PACK_ARGS (old_pack),
13096 /* Inconsistent unification of this parameter pack. */
13102 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
13104 /* Keep the original deduced argument pack. */
13105 TMPL_ARG (targs, level, idx) = old_pack;
13112 /* Deduce the value of template parameters. TPARMS is the (innermost)
13113 set of template parameters to a template. TARGS is the bindings
13114 for those template parameters, as determined thus far; TARGS may
13115 include template arguments for outer levels of template parameters
13116 as well. PARM is a parameter to a template function, or a
13117 subcomponent of that parameter; ARG is the corresponding argument.
13118 This function attempts to match PARM with ARG in a manner
13119 consistent with the existing assignments in TARGS. If more values
13120 are deduced, then TARGS is updated.
13122 Returns 0 if the type deduction succeeds, 1 otherwise. The
13123 parameter STRICT is a bitwise or of the following flags:
13126 Require an exact match between PARM and ARG.
13127 UNIFY_ALLOW_MORE_CV_QUAL:
13128 Allow the deduced ARG to be more cv-qualified (by qualification
13129 conversion) than ARG.
13130 UNIFY_ALLOW_LESS_CV_QUAL:
13131 Allow the deduced ARG to be less cv-qualified than ARG.
13132 UNIFY_ALLOW_DERIVED:
13133 Allow the deduced ARG to be a template base class of ARG,
13134 or a pointer to a template base class of the type pointed to by
13136 UNIFY_ALLOW_INTEGER:
13137 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
13138 case for more information.
13139 UNIFY_ALLOW_OUTER_LEVEL:
13140 This is the outermost level of a deduction. Used to determine validity
13141 of qualification conversions. A valid qualification conversion must
13142 have const qualified pointers leading up to the inner type which
13143 requires additional CV quals, except at the outer level, where const
13144 is not required [conv.qual]. It would be normal to set this flag in
13145 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
13146 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
13147 This is the outermost level of a deduction, and PARM can be more CV
13148 qualified at this point.
13149 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
13150 This is the outermost level of a deduction, and PARM can be less CV
13151 qualified at this point. */
13154 unify (tree tparms, tree targs, tree parm, tree arg, int strict)
13159 int strict_in = strict;
13161 /* I don't think this will do the right thing with respect to types.
13162 But the only case I've seen it in so far has been array bounds, where
13163 signedness is the only information lost, and I think that will be
13165 while (TREE_CODE (parm) == NOP_EXPR)
13166 parm = TREE_OPERAND (parm, 0);
13168 if (arg == error_mark_node)
13170 if (arg == unknown_type_node
13171 || arg == init_list_type_node)
13172 /* We can't deduce anything from this, but we might get all the
13173 template args from other function args. */
13176 /* If PARM uses template parameters, then we can't bail out here,
13177 even if ARG == PARM, since we won't record unifications for the
13178 template parameters. We might need them if we're trying to
13179 figure out which of two things is more specialized. */
13180 if (arg == parm && !uses_template_parms (parm))
13183 /* Handle init lists early, so the rest of the function can assume
13184 we're dealing with a type. */
13185 if (BRACE_ENCLOSED_INITIALIZER_P (arg))
13190 if (!is_std_init_list (parm))
13191 /* We can only deduce from an initializer list argument if the
13192 parameter is std::initializer_list; otherwise this is a
13193 non-deduced context. */
13196 elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (parm), 0);
13198 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg), i, elt)
13200 if (!BRACE_ENCLOSED_INITIALIZER_P (elt))
13201 elt = TREE_TYPE (elt);
13202 if (unify (tparms, targs, elttype, elt, UNIFY_ALLOW_NONE))
13208 /* Immediately reject some pairs that won't unify because of
13209 cv-qualification mismatches. */
13210 if (TREE_CODE (arg) == TREE_CODE (parm)
13212 /* It is the elements of the array which hold the cv quals of an array
13213 type, and the elements might be template type parms. We'll check
13214 when we recurse. */
13215 && TREE_CODE (arg) != ARRAY_TYPE
13216 /* We check the cv-qualifiers when unifying with template type
13217 parameters below. We want to allow ARG `const T' to unify with
13218 PARM `T' for example, when computing which of two templates
13219 is more specialized, for example. */
13220 && TREE_CODE (arg) != TEMPLATE_TYPE_PARM
13221 && !check_cv_quals_for_unify (strict_in, arg, parm))
13224 if (!(strict & UNIFY_ALLOW_OUTER_LEVEL)
13225 && TYPE_P (parm) && !CP_TYPE_CONST_P (parm))
13226 strict &= ~UNIFY_ALLOW_MORE_CV_QUAL;
13227 strict &= ~UNIFY_ALLOW_OUTER_LEVEL;
13228 strict &= ~UNIFY_ALLOW_DERIVED;
13229 strict &= ~UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
13230 strict &= ~UNIFY_ALLOW_OUTER_LESS_CV_QUAL;
13232 switch (TREE_CODE (parm))
13234 case TYPENAME_TYPE:
13236 case UNBOUND_CLASS_TEMPLATE:
13237 /* In a type which contains a nested-name-specifier, template
13238 argument values cannot be deduced for template parameters used
13239 within the nested-name-specifier. */
13242 case TEMPLATE_TYPE_PARM:
13243 case TEMPLATE_TEMPLATE_PARM:
13244 case BOUND_TEMPLATE_TEMPLATE_PARM:
13245 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
13246 if (tparm == error_mark_node)
13249 if (TEMPLATE_TYPE_LEVEL (parm)
13250 != template_decl_level (tparm))
13251 /* The PARM is not one we're trying to unify. Just check
13252 to see if it matches ARG. */
13253 return (TREE_CODE (arg) == TREE_CODE (parm)
13254 && same_type_p (parm, arg)) ? 0 : 1;
13255 idx = TEMPLATE_TYPE_IDX (parm);
13256 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
13257 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, idx));
13259 /* Check for mixed types and values. */
13260 if ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
13261 && TREE_CODE (tparm) != TYPE_DECL)
13262 || (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
13263 && TREE_CODE (tparm) != TEMPLATE_DECL))
13266 if (TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
13268 /* ARG must be constructed from a template class or a template
13269 template parameter. */
13270 if (TREE_CODE (arg) != BOUND_TEMPLATE_TEMPLATE_PARM
13271 && !CLASSTYPE_SPECIALIZATION_OF_PRIMARY_TEMPLATE_P (arg))
13275 tree parmvec = TYPE_TI_ARGS (parm);
13276 tree argvec = INNERMOST_TEMPLATE_ARGS (TYPE_TI_ARGS (arg));
13278 = DECL_INNERMOST_TEMPLATE_PARMS
13279 (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (parm));
13281 int parm_variadic_p = 0;
13283 /* The resolution to DR150 makes clear that default
13284 arguments for an N-argument may not be used to bind T
13285 to a template template parameter with fewer than N
13286 parameters. It is not safe to permit the binding of
13287 default arguments as an extension, as that may change
13288 the meaning of a conforming program. Consider:
13290 struct Dense { static const unsigned int dim = 1; };
13292 template <template <typename> class View,
13294 void operator+(float, View<Block> const&);
13296 template <typename Block,
13297 unsigned int Dim = Block::dim>
13298 struct Lvalue_proxy { operator float() const; };
13302 Lvalue_proxy<Dense> p;
13307 Here, if Lvalue_proxy is permitted to bind to View, then
13308 the global operator+ will be used; if they are not, the
13309 Lvalue_proxy will be converted to float. */
13310 if (coerce_template_parms (parm_parms,
13312 TYPE_TI_TEMPLATE (parm),
13314 /*require_all_args=*/true,
13315 /*use_default_args=*/false)
13316 == error_mark_node)
13319 /* Deduce arguments T, i from TT<T> or TT<i>.
13320 We check each element of PARMVEC and ARGVEC individually
13321 rather than the whole TREE_VEC since they can have
13322 different number of elements. */
13324 parmvec = expand_template_argument_pack (parmvec);
13325 argvec = expand_template_argument_pack (argvec);
13327 len = TREE_VEC_LENGTH (parmvec);
13329 /* Check if the parameters end in a pack, making them
13332 && PACK_EXPANSION_P (TREE_VEC_ELT (parmvec, len - 1)))
13333 parm_variadic_p = 1;
13335 if (TREE_VEC_LENGTH (argvec) < len - parm_variadic_p)
13338 for (i = 0; i < len - parm_variadic_p; ++i)
13340 if (unify (tparms, targs,
13341 TREE_VEC_ELT (parmvec, i),
13342 TREE_VEC_ELT (argvec, i),
13347 if (parm_variadic_p
13348 && unify_pack_expansion (tparms, targs,
13351 /*call_args_p=*/false,
13355 arg = TYPE_TI_TEMPLATE (arg);
13357 /* Fall through to deduce template name. */
13360 if (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
13361 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
13363 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
13365 /* Simple cases: Value already set, does match or doesn't. */
13366 if (targ != NULL_TREE && template_args_equal (targ, arg))
13373 /* If PARM is `const T' and ARG is only `int', we don't have
13374 a match unless we are allowing additional qualification.
13375 If ARG is `const int' and PARM is just `T' that's OK;
13376 that binds `const int' to `T'. */
13377 if (!check_cv_quals_for_unify (strict_in | UNIFY_ALLOW_LESS_CV_QUAL,
13381 /* Consider the case where ARG is `const volatile int' and
13382 PARM is `const T'. Then, T should be `volatile int'. */
13383 arg = cp_build_qualified_type_real
13384 (arg, cp_type_quals (arg) & ~cp_type_quals (parm), tf_none);
13385 if (arg == error_mark_node)
13388 /* Simple cases: Value already set, does match or doesn't. */
13389 if (targ != NULL_TREE && same_type_p (targ, arg))
13394 /* Make sure that ARG is not a variable-sized array. (Note
13395 that were talking about variable-sized arrays (like
13396 `int[n]'), rather than arrays of unknown size (like
13397 `int[]').) We'll get very confused by such a type since
13398 the bound of the array will not be computable in an
13399 instantiation. Besides, such types are not allowed in
13400 ISO C++, so we can do as we please here. */
13401 if (variably_modified_type_p (arg, NULL_TREE))
13405 /* If ARG is a parameter pack or an expansion, we cannot unify
13406 against it unless PARM is also a parameter pack. */
13407 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
13408 && !template_parameter_pack_p (parm))
13411 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
13414 case TEMPLATE_PARM_INDEX:
13415 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
13416 if (tparm == error_mark_node)
13419 if (TEMPLATE_PARM_LEVEL (parm)
13420 != template_decl_level (tparm))
13421 /* The PARM is not one we're trying to unify. Just check
13422 to see if it matches ARG. */
13423 return !(TREE_CODE (arg) == TREE_CODE (parm)
13424 && cp_tree_equal (parm, arg));
13426 idx = TEMPLATE_PARM_IDX (parm);
13427 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
13430 return !cp_tree_equal (targ, arg);
13432 /* [temp.deduct.type] If, in the declaration of a function template
13433 with a non-type template-parameter, the non-type
13434 template-parameter is used in an expression in the function
13435 parameter-list and, if the corresponding template-argument is
13436 deduced, the template-argument type shall match the type of the
13437 template-parameter exactly, except that a template-argument
13438 deduced from an array bound may be of any integral type.
13439 The non-type parameter might use already deduced type parameters. */
13440 tparm = tsubst (TREE_TYPE (parm), targs, 0, NULL_TREE);
13441 if (!TREE_TYPE (arg))
13442 /* Template-parameter dependent expression. Just accept it for now.
13443 It will later be processed in convert_template_argument. */
13445 else if (same_type_p (TREE_TYPE (arg), tparm))
13447 else if ((strict & UNIFY_ALLOW_INTEGER)
13448 && (TREE_CODE (tparm) == INTEGER_TYPE
13449 || TREE_CODE (tparm) == BOOLEAN_TYPE))
13450 /* Convert the ARG to the type of PARM; the deduced non-type
13451 template argument must exactly match the types of the
13452 corresponding parameter. */
13453 arg = fold (build_nop (TREE_TYPE (parm), arg));
13454 else if (uses_template_parms (tparm))
13455 /* We haven't deduced the type of this parameter yet. Try again
13461 /* If ARG is a parameter pack or an expansion, we cannot unify
13462 against it unless PARM is also a parameter pack. */
13463 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
13464 && !TEMPLATE_PARM_PARAMETER_PACK (parm))
13467 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
13472 /* A pointer-to-member constant can be unified only with
13473 another constant. */
13474 if (TREE_CODE (arg) != PTRMEM_CST)
13477 /* Just unify the class member. It would be useless (and possibly
13478 wrong, depending on the strict flags) to unify also
13479 PTRMEM_CST_CLASS, because we want to be sure that both parm and
13480 arg refer to the same variable, even if through different
13481 classes. For instance:
13483 struct A { int x; };
13486 Unification of &A::x and &B::x must succeed. */
13487 return unify (tparms, targs, PTRMEM_CST_MEMBER (parm),
13488 PTRMEM_CST_MEMBER (arg), strict);
13493 if (TREE_CODE (arg) != POINTER_TYPE)
13496 /* [temp.deduct.call]
13498 A can be another pointer or pointer to member type that can
13499 be converted to the deduced A via a qualification
13500 conversion (_conv.qual_).
13502 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
13503 This will allow for additional cv-qualification of the
13504 pointed-to types if appropriate. */
13506 if (TREE_CODE (TREE_TYPE (arg)) == RECORD_TYPE)
13507 /* The derived-to-base conversion only persists through one
13508 level of pointers. */
13509 strict |= (strict_in & UNIFY_ALLOW_DERIVED);
13511 return unify (tparms, targs, TREE_TYPE (parm),
13512 TREE_TYPE (arg), strict);
13515 case REFERENCE_TYPE:
13516 if (TREE_CODE (arg) != REFERENCE_TYPE)
13518 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
13519 strict & UNIFY_ALLOW_MORE_CV_QUAL);
13522 if (TREE_CODE (arg) != ARRAY_TYPE)
13524 if ((TYPE_DOMAIN (parm) == NULL_TREE)
13525 != (TYPE_DOMAIN (arg) == NULL_TREE))
13527 if (TYPE_DOMAIN (parm) != NULL_TREE)
13534 /* Our representation of array types uses "N - 1" as the
13535 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
13536 not an integer constant. We cannot unify arbitrarily
13537 complex expressions, so we eliminate the MINUS_EXPRs
13539 parm_max = TYPE_MAX_VALUE (TYPE_DOMAIN (parm));
13540 parm_cst = TREE_CODE (parm_max) == INTEGER_CST;
13543 gcc_assert (TREE_CODE (parm_max) == MINUS_EXPR);
13544 parm_max = TREE_OPERAND (parm_max, 0);
13546 arg_max = TYPE_MAX_VALUE (TYPE_DOMAIN (arg));
13547 arg_cst = TREE_CODE (arg_max) == INTEGER_CST;
13550 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
13551 trying to unify the type of a variable with the type
13552 of a template parameter. For example:
13554 template <unsigned int N>
13555 void f (char (&) [N]);
13562 Here, the type of the ARG will be "int [g(i)]", and
13563 may be a SAVE_EXPR, etc. */
13564 if (TREE_CODE (arg_max) != MINUS_EXPR)
13566 arg_max = TREE_OPERAND (arg_max, 0);
13569 /* If only one of the bounds used a MINUS_EXPR, compensate
13570 by adding one to the other bound. */
13571 if (parm_cst && !arg_cst)
13572 parm_max = fold_build2 (PLUS_EXPR,
13576 else if (arg_cst && !parm_cst)
13577 arg_max = fold_build2 (PLUS_EXPR,
13582 if (unify (tparms, targs, parm_max, arg_max, UNIFY_ALLOW_INTEGER))
13585 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
13586 strict & UNIFY_ALLOW_MORE_CV_QUAL);
13593 case ENUMERAL_TYPE:
13595 if (TREE_CODE (arg) != TREE_CODE (parm))
13598 /* We have already checked cv-qualification at the top of the
13600 if (!same_type_ignoring_top_level_qualifiers_p (arg, parm))
13603 /* As far as unification is concerned, this wins. Later checks
13604 will invalidate it if necessary. */
13607 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
13608 /* Type INTEGER_CST can come from ordinary constant template args. */
13610 while (TREE_CODE (arg) == NOP_EXPR)
13611 arg = TREE_OPERAND (arg, 0);
13613 if (TREE_CODE (arg) != INTEGER_CST)
13615 return !tree_int_cst_equal (parm, arg);
13620 if (TREE_CODE (arg) != TREE_VEC)
13622 if (TREE_VEC_LENGTH (parm) != TREE_VEC_LENGTH (arg))
13624 for (i = 0; i < TREE_VEC_LENGTH (parm); ++i)
13625 if (unify (tparms, targs,
13626 TREE_VEC_ELT (parm, i), TREE_VEC_ELT (arg, i),
13634 if (TREE_CODE (arg) != TREE_CODE (parm))
13637 if (TYPE_PTRMEMFUNC_P (parm))
13639 if (!TYPE_PTRMEMFUNC_P (arg))
13642 return unify (tparms, targs,
13643 TYPE_PTRMEMFUNC_FN_TYPE (parm),
13644 TYPE_PTRMEMFUNC_FN_TYPE (arg),
13648 if (CLASSTYPE_TEMPLATE_INFO (parm))
13650 tree t = NULL_TREE;
13652 if (strict_in & UNIFY_ALLOW_DERIVED)
13654 /* First, we try to unify the PARM and ARG directly. */
13655 t = try_class_unification (tparms, targs,
13660 /* Fallback to the special case allowed in
13661 [temp.deduct.call]:
13663 If P is a class, and P has the form
13664 template-id, then A can be a derived class of
13665 the deduced A. Likewise, if P is a pointer to
13666 a class of the form template-id, A can be a
13667 pointer to a derived class pointed to by the
13669 t = get_template_base (tparms, targs, parm, arg);
13675 else if (CLASSTYPE_TEMPLATE_INFO (arg)
13676 && (CLASSTYPE_TI_TEMPLATE (parm)
13677 == CLASSTYPE_TI_TEMPLATE (arg)))
13678 /* Perhaps PARM is something like S<U> and ARG is S<int>.
13679 Then, we should unify `int' and `U'. */
13682 /* There's no chance of unification succeeding. */
13685 return unify (tparms, targs, CLASSTYPE_TI_ARGS (parm),
13686 CLASSTYPE_TI_ARGS (t), UNIFY_ALLOW_NONE);
13688 else if (!same_type_ignoring_top_level_qualifiers_p (parm, arg))
13693 case FUNCTION_TYPE:
13694 if (TREE_CODE (arg) != TREE_CODE (parm))
13697 /* CV qualifications for methods can never be deduced, they must
13698 match exactly. We need to check them explicitly here,
13699 because type_unification_real treats them as any other
13700 cv-qualified parameter. */
13701 if (TREE_CODE (parm) == METHOD_TYPE
13702 && (!check_cv_quals_for_unify
13704 TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (arg))),
13705 TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (parm))))))
13708 if (unify (tparms, targs, TREE_TYPE (parm),
13709 TREE_TYPE (arg), UNIFY_ALLOW_NONE))
13711 return type_unification_real (tparms, targs, TYPE_ARG_TYPES (parm),
13712 TYPE_ARG_TYPES (arg), 1, DEDUCE_EXACT,
13716 /* Unify a pointer to member with a pointer to member function, which
13717 deduces the type of the member as a function type. */
13718 if (TYPE_PTRMEMFUNC_P (arg))
13722 cp_cv_quals cv_quals;
13724 /* Check top-level cv qualifiers */
13725 if (!check_cv_quals_for_unify (UNIFY_ALLOW_NONE, arg, parm))
13728 if (unify (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
13729 TYPE_PTRMEMFUNC_OBJECT_TYPE (arg), UNIFY_ALLOW_NONE))
13732 /* Determine the type of the function we are unifying against. */
13733 method_type = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (arg));
13735 build_function_type (TREE_TYPE (method_type),
13736 TREE_CHAIN (TYPE_ARG_TYPES (method_type)));
13738 /* Extract the cv-qualifiers of the member function from the
13739 implicit object parameter and place them on the function
13740 type to be restored later. */
13742 cp_type_quals(TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (method_type))));
13743 fntype = build_qualified_type (fntype, cv_quals);
13744 return unify (tparms, targs, TREE_TYPE (parm), fntype, strict);
13747 if (TREE_CODE (arg) != OFFSET_TYPE)
13749 if (unify (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
13750 TYPE_OFFSET_BASETYPE (arg), UNIFY_ALLOW_NONE))
13752 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
13756 if (DECL_TEMPLATE_PARM_P (parm))
13757 return unify (tparms, targs, DECL_INITIAL (parm), arg, strict);
13758 if (arg != integral_constant_value (parm))
13763 case TEMPLATE_DECL:
13764 /* Matched cases are handled by the ARG == PARM test above. */
13767 case TYPE_ARGUMENT_PACK:
13768 case NONTYPE_ARGUMENT_PACK:
13770 tree packed_parms = ARGUMENT_PACK_ARGS (parm);
13771 tree packed_args = ARGUMENT_PACK_ARGS (arg);
13772 int i, len = TREE_VEC_LENGTH (packed_parms);
13773 int argslen = TREE_VEC_LENGTH (packed_args);
13774 int parm_variadic_p = 0;
13776 for (i = 0; i < len; ++i)
13778 if (PACK_EXPANSION_P (TREE_VEC_ELT (packed_parms, i)))
13781 /* We can unify against something with a trailing
13783 parm_variadic_p = 1;
13785 /* Since there is something following the pack
13786 expansion, we cannot unify this template argument
13793 /* If we don't have enough arguments to satisfy the parameters
13794 (not counting the pack expression at the end), or we have
13795 too many arguments for a parameter list that doesn't end in
13796 a pack expression, we can't unify. */
13797 if (argslen < (len - parm_variadic_p)
13798 || (argslen > len && !parm_variadic_p))
13801 /* Unify all of the parameters that precede the (optional)
13802 pack expression. */
13803 for (i = 0; i < len - parm_variadic_p; ++i)
13805 if (unify (tparms, targs, TREE_VEC_ELT (packed_parms, i),
13806 TREE_VEC_ELT (packed_args, i), strict))
13810 if (parm_variadic_p)
13811 return unify_pack_expansion (tparms, targs,
13812 packed_parms, packed_args,
13813 strict, /*call_args_p=*/false,
13821 case DECLTYPE_TYPE:
13822 /* Cannot deduce anything from TYPEOF_TYPE or DECLTYPE_TYPE
13827 /* Unification fails if we hit an error node. */
13831 gcc_assert (EXPR_P (parm));
13833 /* We must be looking at an expression. This can happen with
13837 void foo(S<I>, S<I + 2>);
13839 This is a "nondeduced context":
13843 The nondeduced contexts are:
13845 --A type that is a template-id in which one or more of
13846 the template-arguments is an expression that references
13847 a template-parameter.
13849 In these cases, we assume deduction succeeded, but don't
13850 actually infer any unifications. */
13852 if (!uses_template_parms (parm)
13853 && !template_args_equal (parm, arg))
13860 /* Note that DECL can be defined in this translation unit, if
13864 mark_definable (tree decl)
13867 DECL_NOT_REALLY_EXTERN (decl) = 1;
13868 FOR_EACH_CLONE (clone, decl)
13869 DECL_NOT_REALLY_EXTERN (clone) = 1;
13872 /* Called if RESULT is explicitly instantiated, or is a member of an
13873 explicitly instantiated class. */
13876 mark_decl_instantiated (tree result, int extern_p)
13878 SET_DECL_EXPLICIT_INSTANTIATION (result);
13880 /* If this entity has already been written out, it's too late to
13881 make any modifications. */
13882 if (TREE_ASM_WRITTEN (result))
13885 if (TREE_CODE (result) != FUNCTION_DECL)
13886 /* The TREE_PUBLIC flag for function declarations will have been
13887 set correctly by tsubst. */
13888 TREE_PUBLIC (result) = 1;
13890 /* This might have been set by an earlier implicit instantiation. */
13891 DECL_COMDAT (result) = 0;
13894 DECL_NOT_REALLY_EXTERN (result) = 0;
13897 mark_definable (result);
13898 /* Always make artificials weak. */
13899 if (DECL_ARTIFICIAL (result) && flag_weak)
13900 comdat_linkage (result);
13901 /* For WIN32 we also want to put explicit instantiations in
13902 linkonce sections. */
13903 else if (TREE_PUBLIC (result))
13904 maybe_make_one_only (result);
13907 /* If EXTERN_P, then this function will not be emitted -- unless
13908 followed by an explicit instantiation, at which point its linkage
13909 will be adjusted. If !EXTERN_P, then this function will be
13910 emitted here. In neither circumstance do we want
13911 import_export_decl to adjust the linkage. */
13912 DECL_INTERFACE_KNOWN (result) = 1;
13915 /* Given two function templates PAT1 and PAT2, return:
13917 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
13918 -1 if PAT2 is more specialized than PAT1.
13919 0 if neither is more specialized.
13921 LEN indicates the number of parameters we should consider
13922 (defaulted parameters should not be considered).
13924 The 1998 std underspecified function template partial ordering, and
13925 DR214 addresses the issue. We take pairs of arguments, one from
13926 each of the templates, and deduce them against each other. One of
13927 the templates will be more specialized if all the *other*
13928 template's arguments deduce against its arguments and at least one
13929 of its arguments *does* *not* deduce against the other template's
13930 corresponding argument. Deduction is done as for class templates.
13931 The arguments used in deduction have reference and top level cv
13932 qualifiers removed. Iff both arguments were originally reference
13933 types *and* deduction succeeds in both directions, the template
13934 with the more cv-qualified argument wins for that pairing (if
13935 neither is more cv-qualified, they both are equal). Unlike regular
13936 deduction, after all the arguments have been deduced in this way,
13937 we do *not* verify the deduced template argument values can be
13938 substituted into non-deduced contexts, nor do we have to verify
13939 that all template arguments have been deduced. */
13942 more_specialized_fn (tree pat1, tree pat2, int len)
13944 tree decl1 = DECL_TEMPLATE_RESULT (pat1);
13945 tree decl2 = DECL_TEMPLATE_RESULT (pat2);
13946 tree targs1 = make_tree_vec (DECL_NTPARMS (pat1));
13947 tree targs2 = make_tree_vec (DECL_NTPARMS (pat2));
13948 tree tparms1 = DECL_INNERMOST_TEMPLATE_PARMS (pat1);
13949 tree tparms2 = DECL_INNERMOST_TEMPLATE_PARMS (pat2);
13950 tree args1 = TYPE_ARG_TYPES (TREE_TYPE (decl1));
13951 tree args2 = TYPE_ARG_TYPES (TREE_TYPE (decl2));
13955 /* Remove the this parameter from non-static member functions. If
13956 one is a non-static member function and the other is not a static
13957 member function, remove the first parameter from that function
13958 also. This situation occurs for operator functions where we
13959 locate both a member function (with this pointer) and non-member
13960 operator (with explicit first operand). */
13961 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl1))
13963 len--; /* LEN is the number of significant arguments for DECL1 */
13964 args1 = TREE_CHAIN (args1);
13965 if (!DECL_STATIC_FUNCTION_P (decl2))
13966 args2 = TREE_CHAIN (args2);
13968 else if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl2))
13970 args2 = TREE_CHAIN (args2);
13971 if (!DECL_STATIC_FUNCTION_P (decl1))
13974 args1 = TREE_CHAIN (args1);
13978 /* If only one is a conversion operator, they are unordered. */
13979 if (DECL_CONV_FN_P (decl1) != DECL_CONV_FN_P (decl2))
13982 /* Consider the return type for a conversion function */
13983 if (DECL_CONV_FN_P (decl1))
13985 args1 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl1)), args1);
13986 args2 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl2)), args2);
13990 processing_template_decl++;
13993 /* Stop when an ellipsis is seen. */
13994 && args1 != NULL_TREE && args2 != NULL_TREE)
13996 tree arg1 = TREE_VALUE (args1);
13997 tree arg2 = TREE_VALUE (args2);
13998 int deduce1, deduce2;
14002 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
14003 && TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
14005 /* When both arguments are pack expansions, we need only
14006 unify the patterns themselves. */
14007 arg1 = PACK_EXPANSION_PATTERN (arg1);
14008 arg2 = PACK_EXPANSION_PATTERN (arg2);
14010 /* This is the last comparison we need to do. */
14014 if (TREE_CODE (arg1) == REFERENCE_TYPE)
14016 arg1 = TREE_TYPE (arg1);
14017 quals1 = cp_type_quals (arg1);
14020 if (TREE_CODE (arg2) == REFERENCE_TYPE)
14022 arg2 = TREE_TYPE (arg2);
14023 quals2 = cp_type_quals (arg2);
14026 if ((quals1 < 0) != (quals2 < 0))
14028 /* Only of the args is a reference, see if we should apply
14029 array/function pointer decay to it. This is not part of
14030 DR214, but is, IMHO, consistent with the deduction rules
14031 for the function call itself, and with our earlier
14032 implementation of the underspecified partial ordering
14033 rules. (nathan). */
14036 switch (TREE_CODE (arg1))
14039 arg1 = TREE_TYPE (arg1);
14041 case FUNCTION_TYPE:
14042 arg1 = build_pointer_type (arg1);
14051 switch (TREE_CODE (arg2))
14054 arg2 = TREE_TYPE (arg2);
14056 case FUNCTION_TYPE:
14057 arg2 = build_pointer_type (arg2);
14066 arg1 = TYPE_MAIN_VARIANT (arg1);
14067 arg2 = TYPE_MAIN_VARIANT (arg2);
14069 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION)
14071 int i, len2 = list_length (args2);
14072 tree parmvec = make_tree_vec (1);
14073 tree argvec = make_tree_vec (len2);
14076 /* Setup the parameter vector, which contains only ARG1. */
14077 TREE_VEC_ELT (parmvec, 0) = arg1;
14079 /* Setup the argument vector, which contains the remaining
14081 for (i = 0; i < len2; i++, ta = TREE_CHAIN (ta))
14082 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
14084 deduce1 = !unify_pack_expansion (tparms1, targs1, parmvec,
14085 argvec, UNIFY_ALLOW_NONE,
14086 /*call_args_p=*/false,
14089 /* We cannot deduce in the other direction, because ARG1 is
14090 a pack expansion but ARG2 is not. */
14093 else if (TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
14095 int i, len1 = list_length (args1);
14096 tree parmvec = make_tree_vec (1);
14097 tree argvec = make_tree_vec (len1);
14100 /* Setup the parameter vector, which contains only ARG1. */
14101 TREE_VEC_ELT (parmvec, 0) = arg2;
14103 /* Setup the argument vector, which contains the remaining
14105 for (i = 0; i < len1; i++, ta = TREE_CHAIN (ta))
14106 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
14108 deduce2 = !unify_pack_expansion (tparms2, targs2, parmvec,
14109 argvec, UNIFY_ALLOW_NONE,
14110 /*call_args_p=*/false,
14113 /* We cannot deduce in the other direction, because ARG2 is
14114 a pack expansion but ARG1 is not.*/
14120 /* The normal case, where neither argument is a pack
14122 deduce1 = !unify (tparms1, targs1, arg1, arg2, UNIFY_ALLOW_NONE);
14123 deduce2 = !unify (tparms2, targs2, arg2, arg1, UNIFY_ALLOW_NONE);
14130 if (better1 < 0 && better2 < 0)
14131 /* We've failed to deduce something in either direction.
14132 These must be unordered. */
14135 if (deduce1 && deduce2 && quals1 >= 0 && quals2 >= 0)
14137 /* Deduces in both directions, see if quals can
14138 disambiguate. Pretend the worse one failed to deduce. */
14139 if ((quals1 & quals2) == quals2)
14141 if ((quals1 & quals2) == quals1)
14144 if (deduce1 && !deduce2 && !better2)
14146 if (deduce2 && !deduce1 && !better1)
14149 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
14150 || TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
14151 /* We have already processed all of the arguments in our
14152 handing of the pack expansion type. */
14155 args1 = TREE_CHAIN (args1);
14156 args2 = TREE_CHAIN (args2);
14159 processing_template_decl--;
14161 /* All things being equal, if the next argument is a pack expansion
14162 for one function but not for the other, prefer the
14163 non-variadic function. */
14164 if ((better1 > 0) - (better2 > 0) == 0
14165 && args1 && TREE_VALUE (args1)
14166 && args2 && TREE_VALUE (args2))
14168 if (TREE_CODE (TREE_VALUE (args1)) == TYPE_PACK_EXPANSION)
14169 return TREE_CODE (TREE_VALUE (args2)) == TYPE_PACK_EXPANSION ? 0 : -1;
14170 else if (TREE_CODE (TREE_VALUE (args2)) == TYPE_PACK_EXPANSION)
14174 return (better1 > 0) - (better2 > 0);
14177 /* Determine which of two partial specializations is more specialized.
14179 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
14180 to the first partial specialization. The TREE_VALUE is the
14181 innermost set of template parameters for the partial
14182 specialization. PAT2 is similar, but for the second template.
14184 Return 1 if the first partial specialization is more specialized;
14185 -1 if the second is more specialized; 0 if neither is more
14188 See [temp.class.order] for information about determining which of
14189 two templates is more specialized. */
14192 more_specialized_class (tree pat1, tree pat2)
14197 bool any_deductions = false;
14199 tmpl1 = TREE_TYPE (pat1);
14200 tmpl2 = TREE_TYPE (pat2);
14202 /* Just like what happens for functions, if we are ordering between
14203 different class template specializations, we may encounter dependent
14204 types in the arguments, and we need our dependency check functions
14205 to behave correctly. */
14206 ++processing_template_decl;
14207 targs = get_class_bindings (TREE_VALUE (pat1),
14208 CLASSTYPE_TI_ARGS (tmpl1),
14209 CLASSTYPE_TI_ARGS (tmpl2));
14213 any_deductions = true;
14216 targs = get_class_bindings (TREE_VALUE (pat2),
14217 CLASSTYPE_TI_ARGS (tmpl2),
14218 CLASSTYPE_TI_ARGS (tmpl1));
14222 any_deductions = true;
14224 --processing_template_decl;
14226 /* In the case of a tie where at least one of the class templates
14227 has a parameter pack at the end, the template with the most
14228 non-packed parameters wins. */
14231 && (template_args_variadic_p (TREE_PURPOSE (pat1))
14232 || template_args_variadic_p (TREE_PURPOSE (pat2))))
14234 tree args1 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat1));
14235 tree args2 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat2));
14236 int len1 = TREE_VEC_LENGTH (args1);
14237 int len2 = TREE_VEC_LENGTH (args2);
14239 /* We don't count the pack expansion at the end. */
14240 if (template_args_variadic_p (TREE_PURPOSE (pat1)))
14242 if (template_args_variadic_p (TREE_PURPOSE (pat2)))
14247 else if (len1 < len2)
14254 /* Return the template arguments that will produce the function signature
14255 DECL from the function template FN, with the explicit template
14256 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
14257 also match. Return NULL_TREE if no satisfactory arguments could be
14261 get_bindings (tree fn, tree decl, tree explicit_args, bool check_rettype)
14263 int ntparms = DECL_NTPARMS (fn);
14264 tree targs = make_tree_vec (ntparms);
14266 tree decl_arg_types;
14268 /* Substitute the explicit template arguments into the type of DECL.
14269 The call to fn_type_unification will handle substitution into the
14271 decl_type = TREE_TYPE (decl);
14272 if (explicit_args && uses_template_parms (decl_type))
14275 tree converted_args;
14277 if (DECL_TEMPLATE_INFO (decl))
14278 tmpl = DECL_TI_TEMPLATE (decl);
14280 /* We can get here for some invalid specializations. */
14284 = coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
14285 explicit_args, NULL_TREE,
14287 /*require_all_args=*/false,
14288 /*use_default_args=*/false);
14289 if (converted_args == error_mark_node)
14292 decl_type = tsubst (decl_type, converted_args, tf_none, NULL_TREE);
14293 if (decl_type == error_mark_node)
14297 /* Never do unification on the 'this' parameter. */
14298 decl_arg_types = skip_artificial_parms_for (decl,
14299 TYPE_ARG_TYPES (decl_type));
14301 if (fn_type_unification (fn, explicit_args, targs,
14303 (check_rettype || DECL_CONV_FN_P (fn)
14304 ? TREE_TYPE (decl_type) : NULL_TREE),
14305 DEDUCE_EXACT, LOOKUP_NORMAL))
14311 /* Return the innermost template arguments that, when applied to a
14312 template specialization whose innermost template parameters are
14313 TPARMS, and whose specialization arguments are PARMS, yield the
14316 For example, suppose we have:
14318 template <class T, class U> struct S {};
14319 template <class T> struct S<T*, int> {};
14321 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
14322 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
14323 int}. The resulting vector will be {double}, indicating that `T'
14324 is bound to `double'. */
14327 get_class_bindings (tree tparms, tree spec_args, tree args)
14329 int i, ntparms = TREE_VEC_LENGTH (tparms);
14331 tree innermost_deduced_args;
14333 innermost_deduced_args = make_tree_vec (ntparms);
14334 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
14336 deduced_args = copy_node (args);
14337 SET_TMPL_ARGS_LEVEL (deduced_args,
14338 TMPL_ARGS_DEPTH (deduced_args),
14339 innermost_deduced_args);
14342 deduced_args = innermost_deduced_args;
14344 if (unify (tparms, deduced_args,
14345 INNERMOST_TEMPLATE_ARGS (spec_args),
14346 INNERMOST_TEMPLATE_ARGS (args),
14350 for (i = 0; i < ntparms; ++i)
14351 if (! TREE_VEC_ELT (innermost_deduced_args, i))
14354 /* Verify that nondeduced template arguments agree with the type
14355 obtained from argument deduction.
14359 struct A { typedef int X; };
14360 template <class T, class U> struct C {};
14361 template <class T> struct C<T, typename T::X> {};
14363 Then with the instantiation `C<A, int>', we can deduce that
14364 `T' is `A' but unify () does not check whether `typename T::X'
14366 spec_args = tsubst (spec_args, deduced_args, tf_none, NULL_TREE);
14367 if (spec_args == error_mark_node
14368 /* We only need to check the innermost arguments; the other
14369 arguments will always agree. */
14370 || !comp_template_args (INNERMOST_TEMPLATE_ARGS (spec_args),
14371 INNERMOST_TEMPLATE_ARGS (args)))
14374 /* Now that we have bindings for all of the template arguments,
14375 ensure that the arguments deduced for the template template
14376 parameters have compatible template parameter lists. See the use
14377 of template_template_parm_bindings_ok_p in fn_type_unification
14378 for more information. */
14379 if (!template_template_parm_bindings_ok_p (tparms, deduced_args))
14382 return deduced_args;
14385 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
14386 Return the TREE_LIST node with the most specialized template, if
14387 any. If there is no most specialized template, the error_mark_node
14390 Note that this function does not look at, or modify, the
14391 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
14392 returned is one of the elements of INSTANTIATIONS, callers may
14393 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
14394 and retrieve it from the value returned. */
14397 most_specialized_instantiation (tree templates)
14401 ++processing_template_decl;
14404 for (fn = TREE_CHAIN (templates); fn; fn = TREE_CHAIN (fn))
14408 if (get_bindings (TREE_VALUE (champ),
14409 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
14410 NULL_TREE, /*check_ret=*/false))
14413 if (get_bindings (TREE_VALUE (fn),
14414 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
14415 NULL_TREE, /*check_ret=*/false))
14422 /* Equally specialized, move to next function. If there
14423 is no next function, nothing's most specialized. */
14424 fn = TREE_CHAIN (fn);
14432 /* Now verify that champ is better than everything earlier in the
14433 instantiation list. */
14434 for (fn = templates; fn != champ; fn = TREE_CHAIN (fn))
14435 if (get_bindings (TREE_VALUE (champ),
14436 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
14437 NULL_TREE, /*check_ret=*/false)
14438 || !get_bindings (TREE_VALUE (fn),
14439 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
14440 NULL_TREE, /*check_ret=*/false))
14446 processing_template_decl--;
14449 return error_mark_node;
14454 /* If DECL is a specialization of some template, return the most
14455 general such template. Otherwise, returns NULL_TREE.
14457 For example, given:
14459 template <class T> struct S { template <class U> void f(U); };
14461 if TMPL is `template <class U> void S<int>::f(U)' this will return
14462 the full template. This function will not trace past partial
14463 specializations, however. For example, given in addition:
14465 template <class T> struct S<T*> { template <class U> void f(U); };
14467 if TMPL is `template <class U> void S<int*>::f(U)' this will return
14468 `template <class T> template <class U> S<T*>::f(U)'. */
14471 most_general_template (tree decl)
14473 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
14474 an immediate specialization. */
14475 if (TREE_CODE (decl) == FUNCTION_DECL)
14477 if (DECL_TEMPLATE_INFO (decl)) {
14478 decl = DECL_TI_TEMPLATE (decl);
14480 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
14481 template friend. */
14482 if (TREE_CODE (decl) != TEMPLATE_DECL)
14488 /* Look for more and more general templates. */
14489 while (DECL_TEMPLATE_INFO (decl))
14491 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
14492 (See cp-tree.h for details.) */
14493 if (TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
14496 if (CLASS_TYPE_P (TREE_TYPE (decl))
14497 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)))
14500 /* Stop if we run into an explicitly specialized class template. */
14501 if (!DECL_NAMESPACE_SCOPE_P (decl)
14502 && DECL_CONTEXT (decl)
14503 && CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (decl)))
14506 decl = DECL_TI_TEMPLATE (decl);
14512 /* Return the most specialized of the class template partial
14513 specializations of TMPL which can produce TYPE, a specialization of
14514 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
14515 a _TYPE node corresponding to the partial specialization, while the
14516 TREE_PURPOSE is the set of template arguments that must be
14517 substituted into the TREE_TYPE in order to generate TYPE.
14519 If the choice of partial specialization is ambiguous, a diagnostic
14520 is issued, and the error_mark_node is returned. If there are no
14521 partial specializations of TMPL matching TYPE, then NULL_TREE is
14525 most_specialized_class (tree type, tree tmpl)
14527 tree list = NULL_TREE;
14533 tree outer_args = NULL_TREE;
14535 tmpl = most_general_template (tmpl);
14536 args = CLASSTYPE_TI_ARGS (type);
14538 /* For determining which partial specialization to use, only the
14539 innermost args are interesting. */
14540 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
14542 outer_args = strip_innermost_template_args (args, 1);
14543 args = INNERMOST_TEMPLATE_ARGS (args);
14546 for (t = DECL_TEMPLATE_SPECIALIZATIONS (tmpl); t; t = TREE_CHAIN (t))
14548 tree partial_spec_args;
14550 tree parms = TREE_VALUE (t);
14552 partial_spec_args = CLASSTYPE_TI_ARGS (TREE_TYPE (t));
14557 ++processing_template_decl;
14559 /* Discard the outer levels of args, and then substitute in the
14560 template args from the enclosing class. */
14561 partial_spec_args = INNERMOST_TEMPLATE_ARGS (partial_spec_args);
14562 partial_spec_args = tsubst_template_args
14563 (partial_spec_args, outer_args, tf_none, NULL_TREE);
14565 /* PARMS already refers to just the innermost parms, but the
14566 template parms in partial_spec_args had their levels lowered
14567 by tsubst, so we need to do the same for the parm list. We
14568 can't just tsubst the TREE_VEC itself, as tsubst wants to
14569 treat a TREE_VEC as an argument vector. */
14570 parms = copy_node (parms);
14571 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
14572 TREE_VEC_ELT (parms, i) =
14573 tsubst (TREE_VEC_ELT (parms, i), outer_args, tf_none, NULL_TREE);
14575 --processing_template_decl;
14577 spec_args = get_class_bindings (parms,
14583 spec_args = add_to_template_args (outer_args, spec_args);
14584 list = tree_cons (spec_args, TREE_VALUE (t), list);
14585 TREE_TYPE (list) = TREE_TYPE (t);
14592 ambiguous_p = false;
14595 t = TREE_CHAIN (t);
14596 for (; t; t = TREE_CHAIN (t))
14598 fate = more_specialized_class (champ, t);
14605 t = TREE_CHAIN (t);
14608 ambiguous_p = true;
14617 for (t = list; t && t != champ; t = TREE_CHAIN (t))
14619 fate = more_specialized_class (champ, t);
14622 ambiguous_p = true;
14629 const char *str = "candidates are:";
14630 error ("ambiguous class template instantiation for %q#T", type);
14631 for (t = list; t; t = TREE_CHAIN (t))
14633 error ("%s %+#T", str, TREE_TYPE (t));
14636 return error_mark_node;
14642 /* Explicitly instantiate DECL. */
14645 do_decl_instantiation (tree decl, tree storage)
14647 tree result = NULL_TREE;
14650 if (!decl || decl == error_mark_node)
14651 /* An error occurred, for which grokdeclarator has already issued
14652 an appropriate message. */
14654 else if (! DECL_LANG_SPECIFIC (decl))
14656 error ("explicit instantiation of non-template %q#D", decl);
14659 else if (TREE_CODE (decl) == VAR_DECL)
14661 /* There is an asymmetry here in the way VAR_DECLs and
14662 FUNCTION_DECLs are handled by grokdeclarator. In the case of
14663 the latter, the DECL we get back will be marked as a
14664 template instantiation, and the appropriate
14665 DECL_TEMPLATE_INFO will be set up. This does not happen for
14666 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
14667 should handle VAR_DECLs as it currently handles
14669 if (!DECL_CLASS_SCOPE_P (decl))
14671 error ("%qD is not a static data member of a class template", decl);
14674 result = lookup_field (DECL_CONTEXT (decl), DECL_NAME (decl), 0, false);
14675 if (!result || TREE_CODE (result) != VAR_DECL)
14677 error ("no matching template for %qD found", decl);
14680 if (!same_type_p (TREE_TYPE (result), TREE_TYPE (decl)))
14682 error ("type %qT for explicit instantiation %qD does not match "
14683 "declared type %qT", TREE_TYPE (result), decl,
14688 else if (TREE_CODE (decl) != FUNCTION_DECL)
14690 error ("explicit instantiation of %q#D", decl);
14696 /* Check for various error cases. Note that if the explicit
14697 instantiation is valid the RESULT will currently be marked as an
14698 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
14699 until we get here. */
14701 if (DECL_TEMPLATE_SPECIALIZATION (result))
14703 /* DR 259 [temp.spec].
14705 Both an explicit instantiation and a declaration of an explicit
14706 specialization shall not appear in a program unless the explicit
14707 instantiation follows a declaration of the explicit specialization.
14709 For a given set of template parameters, if an explicit
14710 instantiation of a template appears after a declaration of an
14711 explicit specialization for that template, the explicit
14712 instantiation has no effect. */
14715 else if (DECL_EXPLICIT_INSTANTIATION (result))
14719 No program shall explicitly instantiate any template more
14722 We check DECL_NOT_REALLY_EXTERN so as not to complain when
14723 the first instantiation was `extern' and the second is not,
14724 and EXTERN_P for the opposite case. */
14725 if (DECL_NOT_REALLY_EXTERN (result) && !extern_p)
14726 permerror (input_location, "duplicate explicit instantiation of %q#D", result);
14727 /* If an "extern" explicit instantiation follows an ordinary
14728 explicit instantiation, the template is instantiated. */
14732 else if (!DECL_IMPLICIT_INSTANTIATION (result))
14734 error ("no matching template for %qD found", result);
14737 else if (!DECL_TEMPLATE_INFO (result))
14739 permerror (input_location, "explicit instantiation of non-template %q#D", result);
14743 if (storage == NULL_TREE)
14745 else if (storage == ridpointers[(int) RID_EXTERN])
14747 if (!in_system_header && (cxx_dialect == cxx98))
14748 pedwarn (input_location, OPT_pedantic,
14749 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
14754 error ("storage class %qD applied to template instantiation", storage);
14756 check_explicit_instantiation_namespace (result);
14757 mark_decl_instantiated (result, extern_p);
14759 instantiate_decl (result, /*defer_ok=*/1,
14760 /*expl_inst_class_mem_p=*/false);
14764 mark_class_instantiated (tree t, int extern_p)
14766 SET_CLASSTYPE_EXPLICIT_INSTANTIATION (t);
14767 SET_CLASSTYPE_INTERFACE_KNOWN (t);
14768 CLASSTYPE_INTERFACE_ONLY (t) = extern_p;
14769 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (t)) = extern_p;
14772 CLASSTYPE_DEBUG_REQUESTED (t) = 1;
14773 rest_of_type_compilation (t, 1);
14777 /* Called from do_type_instantiation through binding_table_foreach to
14778 do recursive instantiation for the type bound in ENTRY. */
14780 bt_instantiate_type_proc (binding_entry entry, void *data)
14782 tree storage = *(tree *) data;
14784 if (MAYBE_CLASS_TYPE_P (entry->type)
14785 && !uses_template_parms (CLASSTYPE_TI_ARGS (entry->type)))
14786 do_type_instantiation (TYPE_MAIN_DECL (entry->type), storage, 0);
14789 /* Called from do_type_instantiation to instantiate a member
14790 (a member function or a static member variable) of an
14791 explicitly instantiated class template. */
14793 instantiate_class_member (tree decl, int extern_p)
14795 mark_decl_instantiated (decl, extern_p);
14797 instantiate_decl (decl, /*defer_ok=*/1,
14798 /*expl_inst_class_mem_p=*/true);
14801 /* Perform an explicit instantiation of template class T. STORAGE, if
14802 non-null, is the RID for extern, inline or static. COMPLAIN is
14803 nonzero if this is called from the parser, zero if called recursively,
14804 since the standard is unclear (as detailed below). */
14807 do_type_instantiation (tree t, tree storage, tsubst_flags_t complain)
14812 int previous_instantiation_extern_p = 0;
14814 if (TREE_CODE (t) == TYPE_DECL)
14817 if (! CLASS_TYPE_P (t) || ! CLASSTYPE_TEMPLATE_INFO (t))
14819 error ("explicit instantiation of non-template type %qT", t);
14825 if (!COMPLETE_TYPE_P (t))
14827 if (complain & tf_error)
14828 error ("explicit instantiation of %q#T before definition of template",
14833 if (storage != NULL_TREE)
14835 if (!in_system_header)
14837 if (storage == ridpointers[(int) RID_EXTERN])
14839 if (cxx_dialect == cxx98)
14840 pedwarn (input_location, OPT_pedantic,
14841 "ISO C++ 1998 forbids the use of %<extern%> on "
14842 "explicit instantiations");
14845 pedwarn (input_location, OPT_pedantic,
14846 "ISO C++ forbids the use of %qE"
14847 " on explicit instantiations", storage);
14850 if (storage == ridpointers[(int) RID_INLINE])
14852 else if (storage == ridpointers[(int) RID_EXTERN])
14854 else if (storage == ridpointers[(int) RID_STATIC])
14858 error ("storage class %qD applied to template instantiation",
14864 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (t))
14866 /* DR 259 [temp.spec].
14868 Both an explicit instantiation and a declaration of an explicit
14869 specialization shall not appear in a program unless the explicit
14870 instantiation follows a declaration of the explicit specialization.
14872 For a given set of template parameters, if an explicit
14873 instantiation of a template appears after a declaration of an
14874 explicit specialization for that template, the explicit
14875 instantiation has no effect. */
14878 else if (CLASSTYPE_EXPLICIT_INSTANTIATION (t))
14882 No program shall explicitly instantiate any template more
14885 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
14886 instantiation was `extern'. If EXTERN_P then the second is.
14887 These cases are OK. */
14888 previous_instantiation_extern_p = CLASSTYPE_INTERFACE_ONLY (t);
14890 if (!previous_instantiation_extern_p && !extern_p
14891 && (complain & tf_error))
14892 permerror (input_location, "duplicate explicit instantiation of %q#T", t);
14894 /* If we've already instantiated the template, just return now. */
14895 if (!CLASSTYPE_INTERFACE_ONLY (t))
14899 check_explicit_instantiation_namespace (TYPE_NAME (t));
14900 mark_class_instantiated (t, extern_p);
14908 /* In contrast to implicit instantiation, where only the
14909 declarations, and not the definitions, of members are
14910 instantiated, we have here:
14914 The explicit instantiation of a class template specialization
14915 implies the instantiation of all of its members not
14916 previously explicitly specialized in the translation unit
14917 containing the explicit instantiation.
14919 Of course, we can't instantiate member template classes, since
14920 we don't have any arguments for them. Note that the standard
14921 is unclear on whether the instantiation of the members are
14922 *explicit* instantiations or not. However, the most natural
14923 interpretation is that it should be an explicit instantiation. */
14926 for (tmp = TYPE_METHODS (t); tmp; tmp = TREE_CHAIN (tmp))
14927 if (TREE_CODE (tmp) == FUNCTION_DECL
14928 && DECL_TEMPLATE_INSTANTIATION (tmp))
14929 instantiate_class_member (tmp, extern_p);
14931 for (tmp = TYPE_FIELDS (t); tmp; tmp = TREE_CHAIN (tmp))
14932 if (TREE_CODE (tmp) == VAR_DECL && DECL_TEMPLATE_INSTANTIATION (tmp))
14933 instantiate_class_member (tmp, extern_p);
14935 if (CLASSTYPE_NESTED_UTDS (t))
14936 binding_table_foreach (CLASSTYPE_NESTED_UTDS (t),
14937 bt_instantiate_type_proc, &storage);
14941 /* Given a function DECL, which is a specialization of TMPL, modify
14942 DECL to be a re-instantiation of TMPL with the same template
14943 arguments. TMPL should be the template into which tsubst'ing
14944 should occur for DECL, not the most general template.
14946 One reason for doing this is a scenario like this:
14949 void f(const T&, int i);
14951 void g() { f(3, 7); }
14954 void f(const T& t, const int i) { }
14956 Note that when the template is first instantiated, with
14957 instantiate_template, the resulting DECL will have no name for the
14958 first parameter, and the wrong type for the second. So, when we go
14959 to instantiate the DECL, we regenerate it. */
14962 regenerate_decl_from_template (tree decl, tree tmpl)
14964 /* The arguments used to instantiate DECL, from the most general
14969 args = DECL_TI_ARGS (decl);
14970 code_pattern = DECL_TEMPLATE_RESULT (tmpl);
14972 /* Make sure that we can see identifiers, and compute access
14974 push_access_scope (decl);
14976 if (TREE_CODE (decl) == FUNCTION_DECL)
14984 args_depth = TMPL_ARGS_DEPTH (args);
14985 parms_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
14986 if (args_depth > parms_depth)
14987 args = get_innermost_template_args (args, parms_depth);
14989 specs = tsubst_exception_specification (TREE_TYPE (code_pattern),
14990 args, tf_error, NULL_TREE);
14992 TREE_TYPE (decl) = build_exception_variant (TREE_TYPE (decl),
14995 /* Merge parameter declarations. */
14996 decl_parm = skip_artificial_parms_for (decl,
14997 DECL_ARGUMENTS (decl));
14999 = skip_artificial_parms_for (code_pattern,
15000 DECL_ARGUMENTS (code_pattern));
15001 while (decl_parm && !FUNCTION_PARAMETER_PACK_P (pattern_parm))
15006 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
15007 DECL_NAME (decl_parm) = DECL_NAME (pattern_parm);
15008 parm_type = tsubst (TREE_TYPE (pattern_parm), args, tf_error,
15010 parm_type = type_decays_to (parm_type);
15011 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
15012 TREE_TYPE (decl_parm) = parm_type;
15013 attributes = DECL_ATTRIBUTES (pattern_parm);
15014 if (DECL_ATTRIBUTES (decl_parm) != attributes)
15016 DECL_ATTRIBUTES (decl_parm) = attributes;
15017 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
15019 decl_parm = TREE_CHAIN (decl_parm);
15020 pattern_parm = TREE_CHAIN (pattern_parm);
15022 /* Merge any parameters that match with the function parameter
15024 if (pattern_parm && FUNCTION_PARAMETER_PACK_P (pattern_parm))
15027 tree expanded_types;
15028 /* Expand the TYPE_PACK_EXPANSION that provides the types for
15029 the parameters in this function parameter pack. */
15030 expanded_types = tsubst_pack_expansion (TREE_TYPE (pattern_parm),
15031 args, tf_error, NULL_TREE);
15032 len = TREE_VEC_LENGTH (expanded_types);
15033 for (i = 0; i < len; i++)
15038 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
15039 /* Rename the parameter to include the index. */
15040 DECL_NAME (decl_parm) =
15041 make_ith_pack_parameter_name (DECL_NAME (pattern_parm), i);
15042 parm_type = TREE_VEC_ELT (expanded_types, i);
15043 parm_type = type_decays_to (parm_type);
15044 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
15045 TREE_TYPE (decl_parm) = parm_type;
15046 attributes = DECL_ATTRIBUTES (pattern_parm);
15047 if (DECL_ATTRIBUTES (decl_parm) != attributes)
15049 DECL_ATTRIBUTES (decl_parm) = attributes;
15050 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
15052 decl_parm = TREE_CHAIN (decl_parm);
15055 /* Merge additional specifiers from the CODE_PATTERN. */
15056 if (DECL_DECLARED_INLINE_P (code_pattern)
15057 && !DECL_DECLARED_INLINE_P (decl))
15058 DECL_DECLARED_INLINE_P (decl) = 1;
15060 else if (TREE_CODE (decl) == VAR_DECL)
15061 DECL_INITIAL (decl) =
15062 tsubst_expr (DECL_INITIAL (code_pattern), args,
15063 tf_error, DECL_TI_TEMPLATE (decl),
15064 /*integral_constant_expression_p=*/false);
15066 gcc_unreachable ();
15068 pop_access_scope (decl);
15071 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
15072 substituted to get DECL. */
15075 template_for_substitution (tree decl)
15077 tree tmpl = DECL_TI_TEMPLATE (decl);
15079 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
15080 for the instantiation. This is not always the most general
15081 template. Consider, for example:
15084 struct S { template <class U> void f();
15085 template <> void f<int>(); };
15087 and an instantiation of S<double>::f<int>. We want TD to be the
15088 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
15089 while (/* An instantiation cannot have a definition, so we need a
15090 more general template. */
15091 DECL_TEMPLATE_INSTANTIATION (tmpl)
15092 /* We must also deal with friend templates. Given:
15094 template <class T> struct S {
15095 template <class U> friend void f() {};
15098 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
15099 so far as the language is concerned, but that's still
15100 where we get the pattern for the instantiation from. On
15101 other hand, if the definition comes outside the class, say:
15103 template <class T> struct S {
15104 template <class U> friend void f();
15106 template <class U> friend void f() {}
15108 we don't need to look any further. That's what the check for
15109 DECL_INITIAL is for. */
15110 || (TREE_CODE (decl) == FUNCTION_DECL
15111 && DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION (tmpl)
15112 && !DECL_INITIAL (DECL_TEMPLATE_RESULT (tmpl))))
15114 /* The present template, TD, should not be a definition. If it
15115 were a definition, we should be using it! Note that we
15116 cannot restructure the loop to just keep going until we find
15117 a template with a definition, since that might go too far if
15118 a specialization was declared, but not defined. */
15119 gcc_assert (TREE_CODE (decl) != VAR_DECL
15120 || DECL_IN_AGGR_P (DECL_TEMPLATE_RESULT (tmpl)));
15122 /* Fetch the more general template. */
15123 tmpl = DECL_TI_TEMPLATE (tmpl);
15129 /* Produce the definition of D, a _DECL generated from a template. If
15130 DEFER_OK is nonzero, then we don't have to actually do the
15131 instantiation now; we just have to do it sometime. Normally it is
15132 an error if this is an explicit instantiation but D is undefined.
15133 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
15134 explicitly instantiated class template. */
15137 instantiate_decl (tree d, int defer_ok,
15138 bool expl_inst_class_mem_p)
15140 tree tmpl = DECL_TI_TEMPLATE (d);
15147 bool pattern_defined;
15149 location_t saved_loc = input_location;
15152 /* This function should only be used to instantiate templates for
15153 functions and static member variables. */
15154 gcc_assert (TREE_CODE (d) == FUNCTION_DECL
15155 || TREE_CODE (d) == VAR_DECL);
15157 /* Variables are never deferred; if instantiation is required, they
15158 are instantiated right away. That allows for better code in the
15159 case that an expression refers to the value of the variable --
15160 if the variable has a constant value the referring expression can
15161 take advantage of that fact. */
15162 if (TREE_CODE (d) == VAR_DECL)
15165 /* Don't instantiate cloned functions. Instead, instantiate the
15166 functions they cloned. */
15167 if (TREE_CODE (d) == FUNCTION_DECL && DECL_CLONED_FUNCTION_P (d))
15168 d = DECL_CLONED_FUNCTION (d);
15170 if (DECL_TEMPLATE_INSTANTIATED (d))
15171 /* D has already been instantiated. It might seem reasonable to
15172 check whether or not D is an explicit instantiation, and, if so,
15173 stop here. But when an explicit instantiation is deferred
15174 until the end of the compilation, DECL_EXPLICIT_INSTANTIATION
15175 is set, even though we still need to do the instantiation. */
15178 /* If we already have a specialization of this declaration, then
15179 there's no reason to instantiate it. Note that
15180 retrieve_specialization gives us both instantiations and
15181 specializations, so we must explicitly check
15182 DECL_TEMPLATE_SPECIALIZATION. */
15183 gen_tmpl = most_general_template (tmpl);
15184 gen_args = DECL_TI_ARGS (d);
15185 spec = retrieve_specialization (gen_tmpl, gen_args,
15186 /*class_specializations_p=*/false);
15187 if (spec != NULL_TREE && DECL_TEMPLATE_SPECIALIZATION (spec))
15190 /* This needs to happen before any tsubsting. */
15191 if (! push_tinst_level (d))
15194 timevar_push (TV_PARSE);
15196 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
15197 for the instantiation. */
15198 td = template_for_substitution (d);
15199 code_pattern = DECL_TEMPLATE_RESULT (td);
15201 /* We should never be trying to instantiate a member of a class
15202 template or partial specialization. */
15203 gcc_assert (d != code_pattern);
15205 if ((DECL_NAMESPACE_SCOPE_P (d) && !DECL_INITIALIZED_IN_CLASS_P (d))
15206 || DECL_TEMPLATE_SPECIALIZATION (td))
15207 /* In the case of a friend template whose definition is provided
15208 outside the class, we may have too many arguments. Drop the
15209 ones we don't need. The same is true for specializations. */
15210 args = get_innermost_template_args
15211 (gen_args, TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (td)));
15215 if (TREE_CODE (d) == FUNCTION_DECL)
15216 pattern_defined = (DECL_SAVED_TREE (code_pattern) != NULL_TREE);
15218 pattern_defined = ! DECL_IN_AGGR_P (code_pattern);
15220 /* We may be in the middle of deferred access check. Disable it now. */
15221 push_deferring_access_checks (dk_no_deferred);
15223 /* Unless an explicit instantiation directive has already determined
15224 the linkage of D, remember that a definition is available for
15226 if (pattern_defined
15227 && !DECL_INTERFACE_KNOWN (d)
15228 && !DECL_NOT_REALLY_EXTERN (d))
15229 mark_definable (d);
15231 input_location = DECL_SOURCE_LOCATION (d);
15233 /* If D is a member of an explicitly instantiated class template,
15234 and no definition is available, treat it like an implicit
15236 if (!pattern_defined && expl_inst_class_mem_p
15237 && DECL_EXPLICIT_INSTANTIATION (d))
15239 DECL_NOT_REALLY_EXTERN (d) = 0;
15240 DECL_INTERFACE_KNOWN (d) = 0;
15241 SET_DECL_IMPLICIT_INSTANTIATION (d);
15246 /* Recheck the substitutions to obtain any warning messages
15247 about ignoring cv qualifiers. */
15248 tree gen = DECL_TEMPLATE_RESULT (gen_tmpl);
15249 tree type = TREE_TYPE (gen);
15251 /* Make sure that we can see identifiers, and compute access
15252 correctly. D is already the target FUNCTION_DECL with the
15254 push_access_scope (d);
15256 if (TREE_CODE (gen) == FUNCTION_DECL)
15258 tsubst (DECL_ARGUMENTS (gen), gen_args, tf_warning_or_error, d);
15259 tsubst_exception_specification (type, gen_args, tf_warning_or_error,
15261 /* Don't simply tsubst the function type, as that will give
15262 duplicate warnings about poor parameter qualifications.
15263 The function arguments are the same as the decl_arguments
15264 without the top level cv qualifiers. */
15265 type = TREE_TYPE (type);
15267 tsubst (type, gen_args, tf_warning_or_error, d);
15269 pop_access_scope (d);
15272 /* Check to see whether we know that this template will be
15273 instantiated in some other file, as with "extern template"
15275 external_p = (DECL_INTERFACE_KNOWN (d) && DECL_REALLY_EXTERN (d));
15276 /* In general, we do not instantiate such templates... */
15278 /* ... but we instantiate inline functions so that we can inline
15280 && ! (TREE_CODE (d) == FUNCTION_DECL
15281 && possibly_inlined_p (d))
15282 /* ... we instantiate static data members whose values are
15283 needed in integral constant expressions. */
15284 && ! (TREE_CODE (d) == VAR_DECL
15285 && DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (d)))
15287 /* Defer all other templates, unless we have been explicitly
15288 forbidden from doing so. */
15289 if (/* If there is no definition, we cannot instantiate the
15292 /* If it's OK to postpone instantiation, do so. */
15294 /* If this is a static data member that will be defined
15295 elsewhere, we don't want to instantiate the entire data
15296 member, but we do want to instantiate the initializer so that
15297 we can substitute that elsewhere. */
15298 || (external_p && TREE_CODE (d) == VAR_DECL))
15300 /* The definition of the static data member is now required so
15301 we must substitute the initializer. */
15302 if (TREE_CODE (d) == VAR_DECL
15303 && !DECL_INITIAL (d)
15304 && DECL_INITIAL (code_pattern))
15309 ns = decl_namespace_context (d);
15310 push_nested_namespace (ns);
15311 push_nested_class (DECL_CONTEXT (d));
15312 init = tsubst_expr (DECL_INITIAL (code_pattern),
15314 tf_warning_or_error, NULL_TREE,
15315 /*integral_constant_expression_p=*/false);
15316 cp_finish_decl (d, init, /*init_const_expr_p=*/false,
15317 /*asmspec_tree=*/NULL_TREE,
15318 LOOKUP_ONLYCONVERTING);
15319 pop_nested_class ();
15320 pop_nested_namespace (ns);
15323 /* We restore the source position here because it's used by
15324 add_pending_template. */
15325 input_location = saved_loc;
15327 if (at_eof && !pattern_defined
15328 && DECL_EXPLICIT_INSTANTIATION (d)
15329 && DECL_NOT_REALLY_EXTERN (d))
15332 The definition of a non-exported function template, a
15333 non-exported member function template, or a non-exported
15334 member function or static data member of a class template
15335 shall be present in every translation unit in which it is
15336 explicitly instantiated. */
15337 permerror (input_location, "explicit instantiation of %qD "
15338 "but no definition available", d);
15340 /* ??? Historically, we have instantiated inline functions, even
15341 when marked as "extern template". */
15342 if (!(external_p && TREE_CODE (d) == VAR_DECL))
15343 add_pending_template (d);
15346 /* Tell the repository that D is available in this translation unit
15347 -- and see if it is supposed to be instantiated here. */
15348 if (TREE_PUBLIC (d) && !DECL_REALLY_EXTERN (d) && !repo_emit_p (d))
15350 /* In a PCH file, despite the fact that the repository hasn't
15351 requested instantiation in the PCH it is still possible that
15352 an instantiation will be required in a file that includes the
15355 add_pending_template (d);
15356 /* Instantiate inline functions so that the inliner can do its
15357 job, even though we'll not be emitting a copy of this
15359 if (!(TREE_CODE (d) == FUNCTION_DECL && possibly_inlined_p (d)))
15363 need_push = !cfun || !global_bindings_p ();
15365 push_to_top_level ();
15367 /* Mark D as instantiated so that recursive calls to
15368 instantiate_decl do not try to instantiate it again. */
15369 DECL_TEMPLATE_INSTANTIATED (d) = 1;
15371 /* Regenerate the declaration in case the template has been modified
15372 by a subsequent redeclaration. */
15373 regenerate_decl_from_template (d, td);
15375 /* We already set the file and line above. Reset them now in case
15376 they changed as a result of calling regenerate_decl_from_template. */
15377 input_location = DECL_SOURCE_LOCATION (d);
15379 if (TREE_CODE (d) == VAR_DECL)
15383 /* Clear out DECL_RTL; whatever was there before may not be right
15384 since we've reset the type of the declaration. */
15385 SET_DECL_RTL (d, NULL_RTX);
15386 DECL_IN_AGGR_P (d) = 0;
15388 /* The initializer is placed in DECL_INITIAL by
15389 regenerate_decl_from_template. Pull it out so that
15390 finish_decl can process it. */
15391 init = DECL_INITIAL (d);
15392 DECL_INITIAL (d) = NULL_TREE;
15393 DECL_INITIALIZED_P (d) = 0;
15395 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
15396 initializer. That function will defer actual emission until
15397 we have a chance to determine linkage. */
15398 DECL_EXTERNAL (d) = 0;
15400 /* Enter the scope of D so that access-checking works correctly. */
15401 push_nested_class (DECL_CONTEXT (d));
15402 finish_decl (d, init, NULL_TREE);
15403 pop_nested_class ();
15405 else if (TREE_CODE (d) == FUNCTION_DECL)
15407 htab_t saved_local_specializations;
15412 /* Save away the current list, in case we are instantiating one
15413 template from within the body of another. */
15414 saved_local_specializations = local_specializations;
15416 /* Set up the list of local specializations. */
15417 local_specializations = htab_create (37,
15418 hash_local_specialization,
15419 eq_local_specializations,
15422 /* Set up context. */
15423 start_preparsed_function (d, NULL_TREE, SF_PRE_PARSED);
15425 /* Create substitution entries for the parameters. */
15426 subst_decl = DECL_TEMPLATE_RESULT (template_for_substitution (d));
15427 tmpl_parm = DECL_ARGUMENTS (subst_decl);
15428 spec_parm = DECL_ARGUMENTS (d);
15429 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (d))
15431 register_local_specialization (spec_parm, tmpl_parm);
15432 spec_parm = skip_artificial_parms_for (d, spec_parm);
15433 tmpl_parm = skip_artificial_parms_for (subst_decl, tmpl_parm);
15435 while (tmpl_parm && !FUNCTION_PARAMETER_PACK_P (tmpl_parm))
15437 register_local_specialization (spec_parm, tmpl_parm);
15438 tmpl_parm = TREE_CHAIN (tmpl_parm);
15439 spec_parm = TREE_CHAIN (spec_parm);
15441 if (tmpl_parm && FUNCTION_PARAMETER_PACK_P (tmpl_parm))
15443 /* Collect all of the extra "packed" parameters into an
15447 tree argpack = make_node (NONTYPE_ARGUMENT_PACK);
15448 tree argtypepack = make_node (TYPE_ARGUMENT_PACK);
15452 /* Count how many parameters remain. */
15453 for (t = spec_parm; t; t = TREE_CHAIN (t))
15456 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
15457 parmvec = make_tree_vec (len);
15458 parmtypevec = make_tree_vec (len);
15459 for(i = 0; i < len; i++, spec_parm = TREE_CHAIN (spec_parm))
15461 TREE_VEC_ELT (parmvec, i) = spec_parm;
15462 TREE_VEC_ELT (parmtypevec, i) = TREE_TYPE (spec_parm);
15465 /* Build the argument packs. */
15466 SET_ARGUMENT_PACK_ARGS (argpack, parmvec);
15467 SET_ARGUMENT_PACK_ARGS (argtypepack, parmtypevec);
15468 TREE_TYPE (argpack) = argtypepack;
15470 /* Register the (value) argument pack as a specialization of
15471 TMPL_PARM, then move on. */
15472 register_local_specialization (argpack, tmpl_parm);
15473 tmpl_parm = TREE_CHAIN (tmpl_parm);
15475 gcc_assert (!spec_parm);
15477 /* Substitute into the body of the function. */
15478 tsubst_expr (DECL_SAVED_TREE (code_pattern), args,
15479 tf_warning_or_error, tmpl,
15480 /*integral_constant_expression_p=*/false);
15482 /* Set the current input_location to the end of the function
15483 so that finish_function knows where we are. */
15484 input_location = DECL_STRUCT_FUNCTION (code_pattern)->function_end_locus;
15486 /* We don't need the local specializations any more. */
15487 htab_delete (local_specializations);
15488 local_specializations = saved_local_specializations;
15490 /* Finish the function. */
15491 d = finish_function (0);
15492 expand_or_defer_fn (d);
15495 /* We're not deferring instantiation any more. */
15496 TI_PENDING_TEMPLATE_FLAG (DECL_TEMPLATE_INFO (d)) = 0;
15499 pop_from_top_level ();
15502 input_location = saved_loc;
15503 pop_deferring_access_checks ();
15504 pop_tinst_level ();
15506 timevar_pop (TV_PARSE);
15511 /* Run through the list of templates that we wish we could
15512 instantiate, and instantiate any we can. RETRIES is the
15513 number of times we retry pending template instantiation. */
15516 instantiate_pending_templates (int retries)
15519 location_t saved_loc = input_location;
15521 /* Instantiating templates may trigger vtable generation. This in turn
15522 may require further template instantiations. We place a limit here
15523 to avoid infinite loop. */
15524 if (pending_templates && retries >= max_tinst_depth)
15526 tree decl = pending_templates->tinst->decl;
15528 error ("template instantiation depth exceeds maximum of %d"
15529 " instantiating %q+D, possibly from virtual table generation"
15530 " (use -ftemplate-depth-NN to increase the maximum)",
15531 max_tinst_depth, decl);
15532 if (TREE_CODE (decl) == FUNCTION_DECL)
15533 /* Pretend that we defined it. */
15534 DECL_INITIAL (decl) = error_mark_node;
15540 struct pending_template **t = &pending_templates;
15541 struct pending_template *last = NULL;
15545 tree instantiation = reopen_tinst_level ((*t)->tinst);
15546 bool complete = false;
15548 if (TYPE_P (instantiation))
15552 if (!COMPLETE_TYPE_P (instantiation))
15554 instantiate_class_template (instantiation);
15555 if (CLASSTYPE_TEMPLATE_INSTANTIATION (instantiation))
15556 for (fn = TYPE_METHODS (instantiation);
15558 fn = TREE_CHAIN (fn))
15559 if (! DECL_ARTIFICIAL (fn))
15560 instantiate_decl (fn,
15562 /*expl_inst_class_mem_p=*/false);
15563 if (COMPLETE_TYPE_P (instantiation))
15567 complete = COMPLETE_TYPE_P (instantiation);
15571 if (!DECL_TEMPLATE_SPECIALIZATION (instantiation)
15572 && !DECL_TEMPLATE_INSTANTIATED (instantiation))
15575 = instantiate_decl (instantiation,
15577 /*expl_inst_class_mem_p=*/false);
15578 if (DECL_TEMPLATE_INSTANTIATED (instantiation))
15582 complete = (DECL_TEMPLATE_SPECIALIZATION (instantiation)
15583 || DECL_TEMPLATE_INSTANTIATED (instantiation));
15587 /* If INSTANTIATION has been instantiated, then we don't
15588 need to consider it again in the future. */
15596 current_tinst_level = NULL;
15598 last_pending_template = last;
15600 while (reconsider);
15602 input_location = saved_loc;
15605 /* Substitute ARGVEC into T, which is a list of initializers for
15606 either base class or a non-static data member. The TREE_PURPOSEs
15607 are DECLs, and the TREE_VALUEs are the initializer values. Used by
15608 instantiate_decl. */
15611 tsubst_initializer_list (tree t, tree argvec)
15613 tree inits = NULL_TREE;
15615 for (; t; t = TREE_CHAIN (t))
15619 tree expanded_bases = NULL_TREE;
15620 tree expanded_arguments = NULL_TREE;
15623 if (TREE_CODE (TREE_PURPOSE (t)) == TYPE_PACK_EXPANSION)
15628 /* Expand the base class expansion type into separate base
15630 expanded_bases = tsubst_pack_expansion (TREE_PURPOSE (t), argvec,
15631 tf_warning_or_error,
15633 if (expanded_bases == error_mark_node)
15636 /* We'll be building separate TREE_LISTs of arguments for
15638 len = TREE_VEC_LENGTH (expanded_bases);
15639 expanded_arguments = make_tree_vec (len);
15640 for (i = 0; i < len; i++)
15641 TREE_VEC_ELT (expanded_arguments, i) = NULL_TREE;
15643 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
15644 expand each argument in the TREE_VALUE of t. */
15645 expr = make_node (EXPR_PACK_EXPANSION);
15646 PACK_EXPANSION_PARAMETER_PACKS (expr) =
15647 PACK_EXPANSION_PARAMETER_PACKS (TREE_PURPOSE (t));
15649 if (TREE_VALUE (t) == void_type_node)
15650 /* VOID_TYPE_NODE is used to indicate
15651 value-initialization. */
15653 for (i = 0; i < len; i++)
15654 TREE_VEC_ELT (expanded_arguments, i) = void_type_node;
15658 /* Substitute parameter packs into each argument in the
15660 in_base_initializer = 1;
15661 for (arg = TREE_VALUE (t); arg; arg = TREE_CHAIN (arg))
15663 tree expanded_exprs;
15665 /* Expand the argument. */
15666 SET_PACK_EXPANSION_PATTERN (expr, TREE_VALUE (arg));
15668 = tsubst_pack_expansion (expr, argvec,
15669 tf_warning_or_error,
15671 if (expanded_exprs == error_mark_node)
15674 /* Prepend each of the expanded expressions to the
15675 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
15676 for (i = 0; i < len; i++)
15678 TREE_VEC_ELT (expanded_arguments, i) =
15679 tree_cons (NULL_TREE,
15680 TREE_VEC_ELT (expanded_exprs, i),
15681 TREE_VEC_ELT (expanded_arguments, i));
15684 in_base_initializer = 0;
15686 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
15687 since we built them backwards. */
15688 for (i = 0; i < len; i++)
15690 TREE_VEC_ELT (expanded_arguments, i) =
15691 nreverse (TREE_VEC_ELT (expanded_arguments, i));
15696 for (i = 0; i < len; ++i)
15698 if (expanded_bases)
15700 decl = TREE_VEC_ELT (expanded_bases, i);
15701 decl = expand_member_init (decl);
15702 init = TREE_VEC_ELT (expanded_arguments, i);
15706 decl = tsubst_copy (TREE_PURPOSE (t), argvec,
15707 tf_warning_or_error, NULL_TREE);
15709 decl = expand_member_init (decl);
15710 if (decl && !DECL_P (decl))
15711 in_base_initializer = 1;
15713 init = tsubst_expr (TREE_VALUE (t), argvec,
15714 tf_warning_or_error, NULL_TREE,
15715 /*integral_constant_expression_p=*/false);
15716 in_base_initializer = 0;
15721 init = build_tree_list (decl, init);
15722 TREE_CHAIN (init) = inits;
15730 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
15733 set_current_access_from_decl (tree decl)
15735 if (TREE_PRIVATE (decl))
15736 current_access_specifier = access_private_node;
15737 else if (TREE_PROTECTED (decl))
15738 current_access_specifier = access_protected_node;
15740 current_access_specifier = access_public_node;
15743 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
15744 is the instantiation (which should have been created with
15745 start_enum) and ARGS are the template arguments to use. */
15748 tsubst_enum (tree tag, tree newtag, tree args)
15752 for (e = TYPE_VALUES (tag); e; e = TREE_CHAIN (e))
15757 decl = TREE_VALUE (e);
15758 /* Note that in a template enum, the TREE_VALUE is the
15759 CONST_DECL, not the corresponding INTEGER_CST. */
15760 value = tsubst_expr (DECL_INITIAL (decl),
15761 args, tf_warning_or_error, NULL_TREE,
15762 /*integral_constant_expression_p=*/true);
15764 /* Give this enumeration constant the correct access. */
15765 set_current_access_from_decl (decl);
15767 /* Actually build the enumerator itself. */
15768 build_enumerator (DECL_NAME (decl), value, newtag);
15771 finish_enum (newtag);
15772 DECL_SOURCE_LOCATION (TYPE_NAME (newtag))
15773 = DECL_SOURCE_LOCATION (TYPE_NAME (tag));
15776 /* DECL is a FUNCTION_DECL that is a template specialization. Return
15777 its type -- but without substituting the innermost set of template
15778 arguments. So, innermost set of template parameters will appear in
15782 get_mostly_instantiated_function_type (tree decl)
15790 tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
15791 targs = DECL_TI_ARGS (decl);
15792 tparms = DECL_TEMPLATE_PARMS (tmpl);
15793 parm_depth = TMPL_PARMS_DEPTH (tparms);
15795 /* There should be as many levels of arguments as there are levels
15797 gcc_assert (parm_depth == TMPL_ARGS_DEPTH (targs));
15799 fn_type = TREE_TYPE (tmpl);
15801 if (parm_depth == 1)
15802 /* No substitution is necessary. */
15806 int i, save_access_control;
15809 /* Replace the innermost level of the TARGS with NULL_TREEs to
15810 let tsubst know not to substitute for those parameters. */
15811 partial_args = make_tree_vec (TREE_VEC_LENGTH (targs));
15812 for (i = 1; i < TMPL_ARGS_DEPTH (targs); ++i)
15813 SET_TMPL_ARGS_LEVEL (partial_args, i,
15814 TMPL_ARGS_LEVEL (targs, i));
15815 SET_TMPL_ARGS_LEVEL (partial_args,
15816 TMPL_ARGS_DEPTH (targs),
15817 make_tree_vec (DECL_NTPARMS (tmpl)));
15819 /* Disable access control as this function is used only during
15821 save_access_control = flag_access_control;
15822 flag_access_control = 0;
15824 ++processing_template_decl;
15825 /* Now, do the (partial) substitution to figure out the
15826 appropriate function type. */
15827 fn_type = tsubst (fn_type, partial_args, tf_error, NULL_TREE);
15828 --processing_template_decl;
15830 /* Substitute into the template parameters to obtain the real
15831 innermost set of parameters. This step is important if the
15832 innermost set of template parameters contains value
15833 parameters whose types depend on outer template parameters. */
15834 TREE_VEC_LENGTH (partial_args)--;
15835 tparms = tsubst_template_parms (tparms, partial_args, tf_error);
15837 flag_access_control = save_access_control;
15843 /* Return truthvalue if we're processing a template different from
15844 the last one involved in diagnostics. */
15846 problematic_instantiation_changed (void)
15848 return last_template_error_tick != tinst_level_tick;
15851 /* Remember current template involved in diagnostics. */
15853 record_last_problematic_instantiation (void)
15855 last_template_error_tick = tinst_level_tick;
15858 struct tinst_level *
15859 current_instantiation (void)
15861 return current_tinst_level;
15864 /* [temp.param] Check that template non-type parm TYPE is of an allowable
15865 type. Return zero for ok, nonzero for disallowed. Issue error and
15866 warning messages under control of COMPLAIN. */
15869 invalid_nontype_parm_type_p (tree type, tsubst_flags_t complain)
15871 if (INTEGRAL_TYPE_P (type))
15873 else if (POINTER_TYPE_P (type))
15875 else if (TYPE_PTR_TO_MEMBER_P (type))
15877 else if (TREE_CODE (type) == TEMPLATE_TYPE_PARM)
15879 else if (TREE_CODE (type) == TYPENAME_TYPE)
15882 if (complain & tf_error)
15883 error ("%q#T is not a valid type for a template constant parameter", type);
15887 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
15888 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
15891 dependent_type_p_r (tree type)
15897 A type is dependent if it is:
15899 -- a template parameter. Template template parameters are types
15900 for us (since TYPE_P holds true for them) so we handle
15902 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
15903 || TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM)
15905 /* -- a qualified-id with a nested-name-specifier which contains a
15906 class-name that names a dependent type or whose unqualified-id
15907 names a dependent type. */
15908 if (TREE_CODE (type) == TYPENAME_TYPE)
15910 /* -- a cv-qualified type where the cv-unqualified type is
15912 type = TYPE_MAIN_VARIANT (type);
15913 /* -- a compound type constructed from any dependent type. */
15914 if (TYPE_PTR_TO_MEMBER_P (type))
15915 return (dependent_type_p (TYPE_PTRMEM_CLASS_TYPE (type))
15916 || dependent_type_p (TYPE_PTRMEM_POINTED_TO_TYPE
15918 else if (TREE_CODE (type) == POINTER_TYPE
15919 || TREE_CODE (type) == REFERENCE_TYPE)
15920 return dependent_type_p (TREE_TYPE (type));
15921 else if (TREE_CODE (type) == FUNCTION_TYPE
15922 || TREE_CODE (type) == METHOD_TYPE)
15926 if (dependent_type_p (TREE_TYPE (type)))
15928 for (arg_type = TYPE_ARG_TYPES (type);
15930 arg_type = TREE_CHAIN (arg_type))
15931 if (dependent_type_p (TREE_VALUE (arg_type)))
15935 /* -- an array type constructed from any dependent type or whose
15936 size is specified by a constant expression that is
15937 value-dependent. */
15938 if (TREE_CODE (type) == ARRAY_TYPE)
15940 if (TYPE_DOMAIN (type)
15941 && dependent_type_p (TYPE_DOMAIN (type)))
15943 return dependent_type_p (TREE_TYPE (type));
15945 else if (TREE_CODE (type) == INTEGER_TYPE
15946 && !TREE_CONSTANT (TYPE_MAX_VALUE (type)))
15948 /* If this is the TYPE_DOMAIN of an array type, consider it
15950 return (value_dependent_expression_p (TYPE_MAX_VALUE (type))
15951 || type_dependent_expression_p (TYPE_MAX_VALUE (type)));
15954 /* -- a template-id in which either the template name is a template
15956 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
15958 /* ... or any of the template arguments is a dependent type or
15959 an expression that is type-dependent or value-dependent. */
15960 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INFO (type)
15961 && (any_dependent_template_arguments_p
15962 (INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type)))))
15965 /* All TYPEOF_TYPEs and DECLTYPE_TYPEs are dependent; if the
15966 argument of the `typeof' expression is not type-dependent, then
15967 it should already been have resolved. */
15968 if (TREE_CODE (type) == TYPEOF_TYPE
15969 || TREE_CODE (type) == DECLTYPE_TYPE)
15972 /* A template argument pack is dependent if any of its packed
15974 if (TREE_CODE (type) == TYPE_ARGUMENT_PACK)
15976 tree args = ARGUMENT_PACK_ARGS (type);
15977 int i, len = TREE_VEC_LENGTH (args);
15978 for (i = 0; i < len; ++i)
15979 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
15983 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
15984 be template parameters. */
15985 if (TREE_CODE (type) == TYPE_PACK_EXPANSION)
15988 /* The standard does not specifically mention types that are local
15989 to template functions or local classes, but they should be
15990 considered dependent too. For example:
15992 template <int I> void f() {
15997 The size of `E' cannot be known until the value of `I' has been
15998 determined. Therefore, `E' must be considered dependent. */
15999 scope = TYPE_CONTEXT (type);
16000 if (scope && TYPE_P (scope))
16001 return dependent_type_p (scope);
16002 else if (scope && TREE_CODE (scope) == FUNCTION_DECL)
16003 return type_dependent_expression_p (scope);
16005 /* Other types are non-dependent. */
16009 /* Returns TRUE if TYPE is dependent, in the sense of
16010 [temp.dep.type]. */
16013 dependent_type_p (tree type)
16015 /* If there are no template parameters in scope, then there can't be
16016 any dependent types. */
16017 if (!processing_template_decl)
16019 /* If we are not processing a template, then nobody should be
16020 providing us with a dependent type. */
16022 gcc_assert (TREE_CODE (type) != TEMPLATE_TYPE_PARM || is_auto (type));
16026 /* If the type is NULL, we have not computed a type for the entity
16027 in question; in that case, the type is dependent. */
16031 /* Erroneous types can be considered non-dependent. */
16032 if (type == error_mark_node)
16035 /* If we have not already computed the appropriate value for TYPE,
16037 if (!TYPE_DEPENDENT_P_VALID (type))
16039 TYPE_DEPENDENT_P (type) = dependent_type_p_r (type);
16040 TYPE_DEPENDENT_P_VALID (type) = 1;
16043 return TYPE_DEPENDENT_P (type);
16046 /* Returns TRUE if EXPRESSION is dependent, according to CRITERION. */
16049 dependent_scope_ref_p (tree expression, bool criterion (tree))
16054 gcc_assert (TREE_CODE (expression) == SCOPE_REF);
16056 if (!TYPE_P (TREE_OPERAND (expression, 0)))
16059 scope = TREE_OPERAND (expression, 0);
16060 name = TREE_OPERAND (expression, 1);
16064 An id-expression is type-dependent if it contains a
16065 nested-name-specifier that contains a class-name that names a
16067 /* The suggested resolution to Core Issue 2 implies that if the
16068 qualifying type is the current class, then we must peek
16071 && currently_open_class (scope)
16072 && !criterion (name))
16074 if (dependent_type_p (scope))
16080 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
16081 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
16085 value_dependent_expression_p (tree expression)
16087 if (!processing_template_decl)
16090 /* A name declared with a dependent type. */
16091 if (DECL_P (expression) && type_dependent_expression_p (expression))
16094 switch (TREE_CODE (expression))
16096 case IDENTIFIER_NODE:
16097 /* A name that has not been looked up -- must be dependent. */
16100 case TEMPLATE_PARM_INDEX:
16101 /* A non-type template parm. */
16105 /* A non-type template parm. */
16106 if (DECL_TEMPLATE_PARM_P (expression))
16108 return value_dependent_expression_p (DECL_INITIAL (expression));
16111 /* A constant with integral or enumeration type and is initialized
16112 with an expression that is value-dependent. */
16113 if (DECL_INITIAL (expression)
16114 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (expression))
16115 && value_dependent_expression_p (DECL_INITIAL (expression)))
16119 case DYNAMIC_CAST_EXPR:
16120 case STATIC_CAST_EXPR:
16121 case CONST_CAST_EXPR:
16122 case REINTERPRET_CAST_EXPR:
16124 /* These expressions are value-dependent if the type to which
16125 the cast occurs is dependent or the expression being casted
16126 is value-dependent. */
16128 tree type = TREE_TYPE (expression);
16130 if (dependent_type_p (type))
16133 /* A functional cast has a list of operands. */
16134 expression = TREE_OPERAND (expression, 0);
16137 /* If there are no operands, it must be an expression such
16138 as "int()". This should not happen for aggregate types
16139 because it would form non-constant expressions. */
16140 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
16145 if (TREE_CODE (expression) == TREE_LIST)
16146 return any_value_dependent_elements_p (expression);
16148 return value_dependent_expression_p (expression);
16153 /* A `sizeof' expression is value-dependent if the operand is
16154 type-dependent or is a pack expansion. */
16155 expression = TREE_OPERAND (expression, 0);
16156 if (PACK_EXPANSION_P (expression))
16158 else if (TYPE_P (expression))
16159 return dependent_type_p (expression);
16160 return type_dependent_expression_p (expression);
16163 return dependent_scope_ref_p (expression, value_dependent_expression_p);
16165 case COMPONENT_REF:
16166 return (value_dependent_expression_p (TREE_OPERAND (expression, 0))
16167 || value_dependent_expression_p (TREE_OPERAND (expression, 1)));
16170 /* A CALL_EXPR may appear in a constant expression if it is a
16171 call to a builtin function, e.g., __builtin_constant_p. All
16172 such calls are value-dependent. */
16175 case NONTYPE_ARGUMENT_PACK:
16176 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
16177 is value-dependent. */
16179 tree values = ARGUMENT_PACK_ARGS (expression);
16180 int i, len = TREE_VEC_LENGTH (values);
16182 for (i = 0; i < len; ++i)
16183 if (value_dependent_expression_p (TREE_VEC_ELT (values, i)))
16191 tree type2 = TRAIT_EXPR_TYPE2 (expression);
16192 return (dependent_type_p (TRAIT_EXPR_TYPE1 (expression))
16193 || (type2 ? dependent_type_p (type2) : false));
16197 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
16198 || (value_dependent_expression_p (TREE_OPERAND (expression, 2))));
16201 /* A constant expression is value-dependent if any subexpression is
16202 value-dependent. */
16203 switch (TREE_CODE_CLASS (TREE_CODE (expression)))
16205 case tcc_reference:
16207 return (value_dependent_expression_p
16208 (TREE_OPERAND (expression, 0)));
16210 case tcc_comparison:
16212 return ((value_dependent_expression_p
16213 (TREE_OPERAND (expression, 0)))
16214 || (value_dependent_expression_p
16215 (TREE_OPERAND (expression, 1))));
16217 case tcc_expression:
16221 for (i = 0; i < TREE_OPERAND_LENGTH (expression); ++i)
16222 /* In some cases, some of the operands may be missing.
16223 (For example, in the case of PREDECREMENT_EXPR, the
16224 amount to increment by may be missing.) That doesn't
16225 make the expression dependent. */
16226 if (TREE_OPERAND (expression, i)
16227 && (value_dependent_expression_p
16228 (TREE_OPERAND (expression, i))))
16238 /* The expression is not value-dependent. */
16242 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
16243 [temp.dep.expr]. */
16246 type_dependent_expression_p (tree expression)
16248 if (!processing_template_decl)
16251 if (expression == error_mark_node)
16254 /* An unresolved name is always dependent. */
16255 if (TREE_CODE (expression) == IDENTIFIER_NODE
16256 || TREE_CODE (expression) == USING_DECL)
16259 /* Some expression forms are never type-dependent. */
16260 if (TREE_CODE (expression) == PSEUDO_DTOR_EXPR
16261 || TREE_CODE (expression) == SIZEOF_EXPR
16262 || TREE_CODE (expression) == ALIGNOF_EXPR
16263 || TREE_CODE (expression) == TRAIT_EXPR
16264 || TREE_CODE (expression) == TYPEID_EXPR
16265 || TREE_CODE (expression) == DELETE_EXPR
16266 || TREE_CODE (expression) == VEC_DELETE_EXPR
16267 || TREE_CODE (expression) == THROW_EXPR)
16270 /* The types of these expressions depends only on the type to which
16271 the cast occurs. */
16272 if (TREE_CODE (expression) == DYNAMIC_CAST_EXPR
16273 || TREE_CODE (expression) == STATIC_CAST_EXPR
16274 || TREE_CODE (expression) == CONST_CAST_EXPR
16275 || TREE_CODE (expression) == REINTERPRET_CAST_EXPR
16276 || TREE_CODE (expression) == CAST_EXPR)
16277 return dependent_type_p (TREE_TYPE (expression));
16279 /* The types of these expressions depends only on the type created
16280 by the expression. */
16281 if (TREE_CODE (expression) == NEW_EXPR
16282 || TREE_CODE (expression) == VEC_NEW_EXPR)
16284 /* For NEW_EXPR tree nodes created inside a template, either
16285 the object type itself or a TREE_LIST may appear as the
16287 tree type = TREE_OPERAND (expression, 1);
16288 if (TREE_CODE (type) == TREE_LIST)
16289 /* This is an array type. We need to check array dimensions
16291 return dependent_type_p (TREE_VALUE (TREE_PURPOSE (type)))
16292 || value_dependent_expression_p
16293 (TREE_OPERAND (TREE_VALUE (type), 1));
16295 return dependent_type_p (type);
16298 if (TREE_CODE (expression) == SCOPE_REF
16299 && dependent_scope_ref_p (expression,
16300 type_dependent_expression_p))
16303 if (TREE_CODE (expression) == FUNCTION_DECL
16304 && DECL_LANG_SPECIFIC (expression)
16305 && DECL_TEMPLATE_INFO (expression)
16306 && (any_dependent_template_arguments_p
16307 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (expression)))))
16310 if (TREE_CODE (expression) == TEMPLATE_DECL
16311 && !DECL_TEMPLATE_TEMPLATE_PARM_P (expression))
16314 if (TREE_CODE (expression) == STMT_EXPR)
16315 expression = stmt_expr_value_expr (expression);
16317 if (BRACE_ENCLOSED_INITIALIZER_P (expression))
16322 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), i, elt)
16324 if (type_dependent_expression_p (elt))
16330 if (TREE_TYPE (expression) == unknown_type_node)
16332 if (TREE_CODE (expression) == ADDR_EXPR)
16333 return type_dependent_expression_p (TREE_OPERAND (expression, 0));
16334 if (TREE_CODE (expression) == COMPONENT_REF
16335 || TREE_CODE (expression) == OFFSET_REF)
16337 if (type_dependent_expression_p (TREE_OPERAND (expression, 0)))
16339 expression = TREE_OPERAND (expression, 1);
16340 if (TREE_CODE (expression) == IDENTIFIER_NODE)
16343 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
16344 if (TREE_CODE (expression) == SCOPE_REF)
16347 if (TREE_CODE (expression) == BASELINK)
16348 expression = BASELINK_FUNCTIONS (expression);
16350 if (TREE_CODE (expression) == TEMPLATE_ID_EXPR)
16352 if (any_dependent_template_arguments_p
16353 (TREE_OPERAND (expression, 1)))
16355 expression = TREE_OPERAND (expression, 0);
16357 gcc_assert (TREE_CODE (expression) == OVERLOAD
16358 || TREE_CODE (expression) == FUNCTION_DECL);
16362 if (type_dependent_expression_p (OVL_CURRENT (expression)))
16364 expression = OVL_NEXT (expression);
16369 gcc_assert (TREE_CODE (expression) != TYPE_DECL);
16371 return (dependent_type_p (TREE_TYPE (expression)));
16374 /* Returns TRUE if ARGS (a TREE_LIST of arguments to a function call)
16375 contains a type-dependent expression. */
16378 any_type_dependent_arguments_p (const_tree args)
16382 tree arg = TREE_VALUE (args);
16384 if (type_dependent_expression_p (arg))
16386 args = TREE_CHAIN (args);
16391 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
16392 expressions) contains any value-dependent expressions. */
16395 any_value_dependent_elements_p (const_tree list)
16397 for (; list; list = TREE_CHAIN (list))
16398 if (value_dependent_expression_p (TREE_VALUE (list)))
16404 /* Returns TRUE if the ARG (a template argument) is dependent. */
16407 dependent_template_arg_p (tree arg)
16409 if (!processing_template_decl)
16412 if (TREE_CODE (arg) == TEMPLATE_DECL
16413 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
16414 return dependent_template_p (arg);
16415 else if (ARGUMENT_PACK_P (arg))
16417 tree args = ARGUMENT_PACK_ARGS (arg);
16418 int i, len = TREE_VEC_LENGTH (args);
16419 for (i = 0; i < len; ++i)
16421 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
16427 else if (TYPE_P (arg))
16428 return dependent_type_p (arg);
16430 return (type_dependent_expression_p (arg)
16431 || value_dependent_expression_p (arg));
16434 /* Returns true if ARGS (a collection of template arguments) contains
16435 any types that require structural equality testing. */
16438 any_template_arguments_need_structural_equality_p (tree args)
16445 if (args == error_mark_node)
16448 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
16450 tree level = TMPL_ARGS_LEVEL (args, i + 1);
16451 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
16453 tree arg = TREE_VEC_ELT (level, j);
16454 tree packed_args = NULL_TREE;
16457 if (ARGUMENT_PACK_P (arg))
16459 /* Look inside the argument pack. */
16460 packed_args = ARGUMENT_PACK_ARGS (arg);
16461 len = TREE_VEC_LENGTH (packed_args);
16464 for (k = 0; k < len; ++k)
16467 arg = TREE_VEC_ELT (packed_args, k);
16469 if (error_operand_p (arg))
16471 else if (TREE_CODE (arg) == TEMPLATE_DECL
16472 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
16474 else if (TYPE_P (arg) && TYPE_STRUCTURAL_EQUALITY_P (arg))
16476 else if (!TYPE_P (arg) && TREE_TYPE (arg)
16477 && TYPE_STRUCTURAL_EQUALITY_P (TREE_TYPE (arg)))
16486 /* Returns true if ARGS (a collection of template arguments) contains
16487 any dependent arguments. */
16490 any_dependent_template_arguments_p (const_tree args)
16497 if (args == error_mark_node)
16500 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
16502 const_tree level = TMPL_ARGS_LEVEL (args, i + 1);
16503 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
16504 if (dependent_template_arg_p (TREE_VEC_ELT (level, j)))
16511 /* Returns TRUE if the template TMPL is dependent. */
16514 dependent_template_p (tree tmpl)
16516 if (TREE_CODE (tmpl) == OVERLOAD)
16520 if (dependent_template_p (OVL_FUNCTION (tmpl)))
16522 tmpl = OVL_CHAIN (tmpl);
16527 /* Template template parameters are dependent. */
16528 if (DECL_TEMPLATE_TEMPLATE_PARM_P (tmpl)
16529 || TREE_CODE (tmpl) == TEMPLATE_TEMPLATE_PARM)
16531 /* So are names that have not been looked up. */
16532 if (TREE_CODE (tmpl) == SCOPE_REF
16533 || TREE_CODE (tmpl) == IDENTIFIER_NODE)
16535 /* So are member templates of dependent classes. */
16536 if (TYPE_P (CP_DECL_CONTEXT (tmpl)))
16537 return dependent_type_p (DECL_CONTEXT (tmpl));
16541 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
16544 dependent_template_id_p (tree tmpl, tree args)
16546 return (dependent_template_p (tmpl)
16547 || any_dependent_template_arguments_p (args));
16550 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
16554 dependent_omp_for_p (tree declv, tree initv, tree condv, tree incrv)
16558 if (!processing_template_decl)
16561 for (i = 0; i < TREE_VEC_LENGTH (declv); i++)
16563 tree decl = TREE_VEC_ELT (declv, i);
16564 tree init = TREE_VEC_ELT (initv, i);
16565 tree cond = TREE_VEC_ELT (condv, i);
16566 tree incr = TREE_VEC_ELT (incrv, i);
16568 if (type_dependent_expression_p (decl))
16571 if (init && type_dependent_expression_p (init))
16574 if (type_dependent_expression_p (cond))
16577 if (COMPARISON_CLASS_P (cond)
16578 && (type_dependent_expression_p (TREE_OPERAND (cond, 0))
16579 || type_dependent_expression_p (TREE_OPERAND (cond, 1))))
16582 if (TREE_CODE (incr) == MODOP_EXPR)
16584 if (type_dependent_expression_p (TREE_OPERAND (incr, 0))
16585 || type_dependent_expression_p (TREE_OPERAND (incr, 2)))
16588 else if (type_dependent_expression_p (incr))
16590 else if (TREE_CODE (incr) == MODIFY_EXPR)
16592 if (type_dependent_expression_p (TREE_OPERAND (incr, 0)))
16594 else if (BINARY_CLASS_P (TREE_OPERAND (incr, 1)))
16596 tree t = TREE_OPERAND (incr, 1);
16597 if (type_dependent_expression_p (TREE_OPERAND (t, 0))
16598 || type_dependent_expression_p (TREE_OPERAND (t, 1)))
16607 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
16608 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
16609 no such TYPE can be found. Note that this function peers inside
16610 uninstantiated templates and therefore should be used only in
16611 extremely limited situations. ONLY_CURRENT_P restricts this
16612 peering to the currently open classes hierarchy (which is required
16613 when comparing types). */
16616 resolve_typename_type (tree type, bool only_current_p)
16625 gcc_assert (TREE_CODE (type) == TYPENAME_TYPE);
16627 scope = TYPE_CONTEXT (type);
16628 name = TYPE_IDENTIFIER (type);
16630 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
16631 it first before we can figure out what NAME refers to. */
16632 if (TREE_CODE (scope) == TYPENAME_TYPE)
16633 scope = resolve_typename_type (scope, only_current_p);
16634 /* If we don't know what SCOPE refers to, then we cannot resolve the
16636 if (TREE_CODE (scope) == TYPENAME_TYPE)
16638 /* If the SCOPE is a template type parameter, we have no way of
16639 resolving the name. */
16640 if (TREE_CODE (scope) == TEMPLATE_TYPE_PARM)
16642 /* If the SCOPE is not the current instantiation, there's no reason
16643 to look inside it. */
16644 if (only_current_p && !currently_open_class (scope))
16646 /* If SCOPE isn't the template itself, it will not have a valid
16647 TYPE_FIELDS list. */
16648 if (same_type_p (scope, CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope)))
16649 /* scope is either the template itself or a compatible instantiation
16650 like X<T>, so look up the name in the original template. */
16651 scope = CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope);
16653 /* scope is a partial instantiation, so we can't do the lookup or we
16654 will lose the template arguments. */
16656 /* Enter the SCOPE so that name lookup will be resolved as if we
16657 were in the class definition. In particular, SCOPE will no
16658 longer be considered a dependent type. */
16659 pushed_scope = push_scope (scope);
16660 /* Look up the declaration. */
16661 decl = lookup_member (scope, name, /*protect=*/0, /*want_type=*/true);
16663 result = NULL_TREE;
16665 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
16666 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
16669 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == IDENTIFIER_NODE
16670 && TREE_CODE (decl) == TYPE_DECL)
16672 result = TREE_TYPE (decl);
16673 if (result == error_mark_node)
16674 result = NULL_TREE;
16676 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == TEMPLATE_ID_EXPR
16677 && DECL_CLASS_TEMPLATE_P (decl))
16681 /* Obtain the template and the arguments. */
16682 tmpl = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 0);
16683 args = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 1);
16684 /* Instantiate the template. */
16685 result = lookup_template_class (tmpl, args, NULL_TREE, NULL_TREE,
16686 /*entering_scope=*/0,
16687 tf_error | tf_user);
16688 if (result == error_mark_node)
16689 result = NULL_TREE;
16692 /* Leave the SCOPE. */
16694 pop_scope (pushed_scope);
16696 /* If we failed to resolve it, return the original typename. */
16700 /* If lookup found a typename type, resolve that too. */
16701 if (TREE_CODE (result) == TYPENAME_TYPE && !TYPENAME_IS_RESOLVING_P (result))
16703 /* Ill-formed programs can cause infinite recursion here, so we
16704 must catch that. */
16705 TYPENAME_IS_RESOLVING_P (type) = 1;
16706 result = resolve_typename_type (result, only_current_p);
16707 TYPENAME_IS_RESOLVING_P (type) = 0;
16710 /* Qualify the resulting type. */
16711 quals = cp_type_quals (type);
16713 result = cp_build_qualified_type (result, cp_type_quals (result) | quals);
16718 /* EXPR is an expression which is not type-dependent. Return a proxy
16719 for EXPR that can be used to compute the types of larger
16720 expressions containing EXPR. */
16723 build_non_dependent_expr (tree expr)
16727 /* Preserve null pointer constants so that the type of things like
16728 "p == 0" where "p" is a pointer can be determined. */
16729 if (null_ptr_cst_p (expr))
16731 /* Preserve OVERLOADs; the functions must be available to resolve
16734 if (TREE_CODE (inner_expr) == STMT_EXPR)
16735 inner_expr = stmt_expr_value_expr (inner_expr);
16736 if (TREE_CODE (inner_expr) == ADDR_EXPR)
16737 inner_expr = TREE_OPERAND (inner_expr, 0);
16738 if (TREE_CODE (inner_expr) == COMPONENT_REF)
16739 inner_expr = TREE_OPERAND (inner_expr, 1);
16740 if (is_overloaded_fn (inner_expr)
16741 || TREE_CODE (inner_expr) == OFFSET_REF)
16743 /* There is no need to return a proxy for a variable. */
16744 if (TREE_CODE (expr) == VAR_DECL)
16746 /* Preserve string constants; conversions from string constants to
16747 "char *" are allowed, even though normally a "const char *"
16748 cannot be used to initialize a "char *". */
16749 if (TREE_CODE (expr) == STRING_CST)
16751 /* Preserve arithmetic constants, as an optimization -- there is no
16752 reason to create a new node. */
16753 if (TREE_CODE (expr) == INTEGER_CST || TREE_CODE (expr) == REAL_CST)
16755 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
16756 There is at least one place where we want to know that a
16757 particular expression is a throw-expression: when checking a ?:
16758 expression, there are special rules if the second or third
16759 argument is a throw-expression. */
16760 if (TREE_CODE (expr) == THROW_EXPR)
16763 if (TREE_CODE (expr) == COND_EXPR)
16764 return build3 (COND_EXPR,
16766 TREE_OPERAND (expr, 0),
16767 (TREE_OPERAND (expr, 1)
16768 ? build_non_dependent_expr (TREE_OPERAND (expr, 1))
16769 : build_non_dependent_expr (TREE_OPERAND (expr, 0))),
16770 build_non_dependent_expr (TREE_OPERAND (expr, 2)));
16771 if (TREE_CODE (expr) == COMPOUND_EXPR
16772 && !COMPOUND_EXPR_OVERLOADED (expr))
16773 return build2 (COMPOUND_EXPR,
16775 TREE_OPERAND (expr, 0),
16776 build_non_dependent_expr (TREE_OPERAND (expr, 1)));
16778 /* If the type is unknown, it can't really be non-dependent */
16779 gcc_assert (TREE_TYPE (expr) != unknown_type_node);
16781 /* Otherwise, build a NON_DEPENDENT_EXPR.
16783 REFERENCE_TYPEs are not stripped for expressions in templates
16784 because doing so would play havoc with mangling. Consider, for
16787 template <typename T> void f<T& g>() { g(); }
16789 In the body of "f", the expression for "g" will have
16790 REFERENCE_TYPE, even though the standard says that it should
16791 not. The reason is that we must preserve the syntactic form of
16792 the expression so that mangling (say) "f<g>" inside the body of
16793 "f" works out correctly. Therefore, the REFERENCE_TYPE is
16795 return build1 (NON_DEPENDENT_EXPR, non_reference (TREE_TYPE (expr)), expr);
16798 /* ARGS is a TREE_LIST of expressions as arguments to a function call.
16799 Return a new TREE_LIST with the various arguments replaced with
16800 equivalent non-dependent expressions. */
16803 build_non_dependent_args (tree args)
16808 new_args = NULL_TREE;
16809 for (a = args; a; a = TREE_CHAIN (a))
16810 new_args = tree_cons (NULL_TREE,
16811 build_non_dependent_expr (TREE_VALUE (a)),
16813 return nreverse (new_args);
16816 /* Returns a type which represents 'auto'. We use a TEMPLATE_TYPE_PARM
16817 with a level one deeper than the actual template parms. */
16824 /* ??? Is it worth caching this for multiple autos at the same level? */
16825 au = cxx_make_type (TEMPLATE_TYPE_PARM);
16826 TYPE_NAME (au) = build_decl (TYPE_DECL, get_identifier ("auto"), au);
16827 TYPE_STUB_DECL (au) = TYPE_NAME (au);
16828 TEMPLATE_TYPE_PARM_INDEX (au) = build_template_parm_index
16829 (0, processing_template_decl + 1, processing_template_decl + 1,
16830 TYPE_NAME (au), NULL_TREE);
16831 TYPE_CANONICAL (au) = canonical_type_parameter (au);
16832 DECL_ARTIFICIAL (TYPE_NAME (au)) = 1;
16833 SET_DECL_TEMPLATE_PARM_P (TYPE_NAME (au));
16838 /* Replace auto in TYPE with std::initializer_list<auto>. */
16841 listify_autos (tree type, tree auto_node)
16843 tree std_init_list = namespace_binding
16844 (get_identifier ("initializer_list"), std_node);
16847 if (!std_init_list || !DECL_CLASS_TEMPLATE_P (std_init_list))
16849 error ("deducing auto from brace-enclosed initializer list requires "
16850 "#include <initializer_list>");
16851 return error_mark_node;
16853 argvec = make_tree_vec (1);
16854 TREE_VEC_ELT (argvec, 0) = auto_node;
16855 init_auto = lookup_template_class (std_init_list, argvec, NULL_TREE,
16856 NULL_TREE, 0, tf_warning_or_error);
16858 TREE_VEC_ELT (argvec, 0) = init_auto;
16859 if (processing_template_decl)
16860 argvec = add_to_template_args (current_template_args (), argvec);
16861 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
16864 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
16865 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
16868 do_auto_deduction (tree type, tree init, tree auto_node)
16870 tree parms, args, tparms, targs;
16873 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
16874 with either a new invented type template parameter U or, if the
16875 initializer is a braced-init-list (8.5.4), with
16876 std::initializer_list<U>. */
16877 if (BRACE_ENCLOSED_INITIALIZER_P (init))
16878 type = listify_autos (type, auto_node);
16880 parms = build_tree_list (NULL_TREE, type);
16881 args = build_tree_list (NULL_TREE, init);
16882 tparms = make_tree_vec (1);
16883 targs = make_tree_vec (1);
16884 TREE_VEC_ELT (tparms, 0)
16885 = build_tree_list (NULL_TREE, TYPE_NAME (auto_node));
16886 val = type_unification_real (tparms, targs, parms, args, 0,
16887 DEDUCE_CALL, LOOKUP_NORMAL);
16890 error ("unable to deduce %qT from %qE", type, init);
16891 return error_mark_node;
16894 if (processing_template_decl)
16895 targs = add_to_template_args (current_template_args (), targs);
16896 return tsubst (type, targs, tf_warning_or_error, NULL_TREE);
16899 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
16903 splice_late_return_type (tree type, tree late_return_type)
16907 if (late_return_type == NULL_TREE)
16909 argvec = make_tree_vec (1);
16910 TREE_VEC_ELT (argvec, 0) = late_return_type;
16911 if (processing_template_decl)
16912 argvec = add_to_template_args (current_template_args (), argvec);
16913 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
16916 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto'. */
16919 is_auto (const_tree type)
16921 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
16922 && TYPE_IDENTIFIER (type) == get_identifier ("auto"))
16928 /* Returns true iff TYPE contains a use of 'auto'. Since auto can only
16929 appear as a type-specifier for the declaration in question, we don't
16930 have to look through the whole type. */
16933 type_uses_auto (tree type)
16935 enum tree_code code;
16936 if (is_auto (type))
16939 code = TREE_CODE (type);
16941 if (code == POINTER_TYPE || code == REFERENCE_TYPE
16942 || code == OFFSET_TYPE || code == FUNCTION_TYPE
16943 || code == METHOD_TYPE || code == ARRAY_TYPE)
16944 return type_uses_auto (TREE_TYPE (type));
16946 if (TYPE_PTRMEMFUNC_P (type))
16947 return type_uses_auto (TREE_TYPE (TREE_TYPE
16948 (TYPE_PTRMEMFUNC_FN_TYPE (type))));
16953 #include "gt-cp-pt.h"