1 /* Handle parameterized types (templates) for GNU C++.
2 Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
3 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010, 2011
4 Free Software Foundation, Inc.
5 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
6 Rewritten by Jason Merrill (jason@cygnus.com).
8 This file is part of GCC.
10 GCC is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3, or (at your option)
15 GCC is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with GCC; see the file COPYING3. If not see
22 <http://www.gnu.org/licenses/>. */
24 /* Known bugs or deficiencies include:
26 all methods must be provided in header files; can't use a source
27 file that contains only the method templates and "just win". */
31 #include "coretypes.h"
35 #include "pointer-set.h"
38 #include "c-family/c-common.h"
39 #include "c-family/c-objc.h"
40 #include "cp-objcp-common.h"
41 #include "tree-inline.h"
46 #include "tree-iterator.h"
49 /* The type of functions taking a tree, and some additional data, and
51 typedef int (*tree_fn_t) (tree, void*);
53 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
54 instantiations have been deferred, either because their definitions
55 were not yet available, or because we were putting off doing the work. */
56 struct GTY ((chain_next ("%h.next"))) pending_template {
57 struct pending_template *next;
58 struct tinst_level *tinst;
61 static GTY(()) struct pending_template *pending_templates;
62 static GTY(()) struct pending_template *last_pending_template;
64 int processing_template_parmlist;
65 static int template_header_count;
67 static GTY(()) tree saved_trees;
68 static VEC(int,heap) *inline_parm_levels;
70 static GTY(()) struct tinst_level *current_tinst_level;
72 static GTY(()) tree saved_access_scope;
74 /* Live only within one (recursive) call to tsubst_expr. We use
75 this to pass the statement expression node from the STMT_EXPR
76 to the EXPR_STMT that is its result. */
77 static tree cur_stmt_expr;
79 /* A map from local variable declarations in the body of the template
80 presently being instantiated to the corresponding instantiated
82 static htab_t local_specializations;
84 typedef struct GTY(()) spec_entry
91 static GTY ((param_is (spec_entry)))
92 htab_t decl_specializations;
94 static GTY ((param_is (spec_entry)))
95 htab_t type_specializations;
97 /* Contains canonical template parameter types. The vector is indexed by
98 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
99 TREE_LIST, whose TREE_VALUEs contain the canonical template
100 parameters of various types and levels. */
101 static GTY(()) VEC(tree,gc) *canonical_template_parms;
103 #define UNIFY_ALLOW_NONE 0
104 #define UNIFY_ALLOW_MORE_CV_QUAL 1
105 #define UNIFY_ALLOW_LESS_CV_QUAL 2
106 #define UNIFY_ALLOW_DERIVED 4
107 #define UNIFY_ALLOW_INTEGER 8
108 #define UNIFY_ALLOW_OUTER_LEVEL 16
109 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
110 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
112 enum template_base_result {
114 tbr_ambiguous_baseclass,
118 static void push_access_scope (tree);
119 static void pop_access_scope (tree);
120 static void push_deduction_access_scope (tree);
121 static void pop_deduction_access_scope (tree);
122 static bool resolve_overloaded_unification (tree, tree, tree, tree,
123 unification_kind_t, int,
125 static int try_one_overload (tree, tree, tree, tree, tree,
126 unification_kind_t, int, bool, bool);
127 static int unify (tree, tree, tree, tree, int, bool);
128 static void add_pending_template (tree);
129 static tree reopen_tinst_level (struct tinst_level *);
130 static tree tsubst_initializer_list (tree, tree);
131 static tree get_class_bindings (tree, tree, tree);
132 static tree coerce_template_parms (tree, tree, tree, tsubst_flags_t,
134 static void tsubst_enum (tree, tree, tree);
135 static tree add_to_template_args (tree, tree);
136 static tree add_outermost_template_args (tree, tree);
137 static bool check_instantiated_args (tree, tree, tsubst_flags_t);
138 static int maybe_adjust_types_for_deduction (unification_kind_t, tree*, tree*,
140 static int type_unification_real (tree, tree, tree, const tree *,
141 unsigned int, int, unification_kind_t, int,
143 static void note_template_header (int);
144 static tree convert_nontype_argument_function (tree, tree);
145 static tree convert_nontype_argument (tree, tree, tsubst_flags_t);
146 static tree convert_template_argument (tree, tree, tree,
147 tsubst_flags_t, int, tree);
148 static int for_each_template_parm (tree, tree_fn_t, void*,
149 struct pointer_set_t*, bool);
150 static tree expand_template_argument_pack (tree);
151 static tree build_template_parm_index (int, int, int, int, tree, tree);
152 static bool inline_needs_template_parms (tree);
153 static void push_inline_template_parms_recursive (tree, int);
154 static tree retrieve_local_specialization (tree);
155 static void register_local_specialization (tree, tree);
156 static hashval_t hash_specialization (const void *p);
157 static tree reduce_template_parm_level (tree, tree, int, tree, tsubst_flags_t);
158 static int mark_template_parm (tree, void *);
159 static int template_parm_this_level_p (tree, void *);
160 static tree tsubst_friend_function (tree, tree);
161 static tree tsubst_friend_class (tree, tree);
162 static int can_complete_type_without_circularity (tree);
163 static tree get_bindings (tree, tree, tree, bool);
164 static int template_decl_level (tree);
165 static int check_cv_quals_for_unify (int, tree, tree);
166 static void template_parm_level_and_index (tree, int*, int*);
167 static int unify_pack_expansion (tree, tree, tree,
168 tree, int, bool, bool, bool);
169 static tree tsubst_template_arg (tree, tree, tsubst_flags_t, tree);
170 static tree tsubst_template_args (tree, tree, tsubst_flags_t, tree);
171 static tree tsubst_template_parms (tree, tree, tsubst_flags_t);
172 static void regenerate_decl_from_template (tree, tree);
173 static tree most_specialized_class (tree, tree, tsubst_flags_t);
174 static tree tsubst_aggr_type (tree, tree, tsubst_flags_t, tree, int);
175 static tree tsubst_arg_types (tree, tree, tsubst_flags_t, tree);
176 static tree tsubst_function_type (tree, tree, tsubst_flags_t, tree);
177 static bool check_specialization_scope (void);
178 static tree process_partial_specialization (tree);
179 static void set_current_access_from_decl (tree);
180 static enum template_base_result get_template_base (tree, tree, tree, tree,
182 static tree try_class_unification (tree, tree, tree, tree, bool);
183 static int coerce_template_template_parms (tree, tree, tsubst_flags_t,
185 static bool template_template_parm_bindings_ok_p (tree, tree);
186 static int template_args_equal (tree, tree);
187 static void tsubst_default_arguments (tree);
188 static tree for_each_template_parm_r (tree *, int *, void *);
189 static tree copy_default_args_to_explicit_spec_1 (tree, tree);
190 static void copy_default_args_to_explicit_spec (tree);
191 static int invalid_nontype_parm_type_p (tree, tsubst_flags_t);
192 static int eq_local_specializations (const void *, const void *);
193 static bool dependent_template_arg_p (tree);
194 static bool any_template_arguments_need_structural_equality_p (tree);
195 static bool dependent_type_p_r (tree);
196 static tree tsubst_expr (tree, tree, tsubst_flags_t, tree, bool);
197 static tree tsubst_copy (tree, tree, tsubst_flags_t, tree);
198 static tree tsubst_pack_expansion (tree, tree, tsubst_flags_t, tree);
199 static tree tsubst_decl (tree, tree, tsubst_flags_t);
200 static void perform_typedefs_access_check (tree tmpl, tree targs);
201 static void append_type_to_template_for_access_check_1 (tree, tree, tree,
203 static tree listify (tree);
204 static tree listify_autos (tree, tree);
205 static tree template_parm_to_arg (tree t);
206 static tree current_template_args (void);
207 static tree fixup_template_type_parm_type (tree, int);
208 static tree fixup_template_parm_index (tree, tree, int);
209 static tree tsubst_template_parm (tree, tree, tsubst_flags_t);
211 /* Make the current scope suitable for access checking when we are
212 processing T. T can be FUNCTION_DECL for instantiated function
213 template, or VAR_DECL for static member variable (need by
214 instantiate_decl). */
217 push_access_scope (tree t)
219 gcc_assert (TREE_CODE (t) == FUNCTION_DECL
220 || TREE_CODE (t) == VAR_DECL);
222 if (DECL_FRIEND_CONTEXT (t))
223 push_nested_class (DECL_FRIEND_CONTEXT (t));
224 else if (DECL_CLASS_SCOPE_P (t))
225 push_nested_class (DECL_CONTEXT (t));
227 push_to_top_level ();
229 if (TREE_CODE (t) == FUNCTION_DECL)
231 saved_access_scope = tree_cons
232 (NULL_TREE, current_function_decl, saved_access_scope);
233 current_function_decl = t;
237 /* Restore the scope set up by push_access_scope. T is the node we
241 pop_access_scope (tree t)
243 if (TREE_CODE (t) == FUNCTION_DECL)
245 current_function_decl = TREE_VALUE (saved_access_scope);
246 saved_access_scope = TREE_CHAIN (saved_access_scope);
249 if (DECL_FRIEND_CONTEXT (t) || DECL_CLASS_SCOPE_P (t))
252 pop_from_top_level ();
255 /* Do any processing required when DECL (a member template
256 declaration) is finished. Returns the TEMPLATE_DECL corresponding
257 to DECL, unless it is a specialization, in which case the DECL
258 itself is returned. */
261 finish_member_template_decl (tree decl)
263 if (decl == error_mark_node)
264 return error_mark_node;
266 gcc_assert (DECL_P (decl));
268 if (TREE_CODE (decl) == TYPE_DECL)
272 type = TREE_TYPE (decl);
273 if (type == error_mark_node)
274 return error_mark_node;
275 if (MAYBE_CLASS_TYPE_P (type)
276 && CLASSTYPE_TEMPLATE_INFO (type)
277 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
279 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
280 check_member_template (tmpl);
285 else if (TREE_CODE (decl) == FIELD_DECL)
286 error ("data member %qD cannot be a member template", decl);
287 else if (DECL_TEMPLATE_INFO (decl))
289 if (!DECL_TEMPLATE_SPECIALIZATION (decl))
291 check_member_template (DECL_TI_TEMPLATE (decl));
292 return DECL_TI_TEMPLATE (decl);
298 error ("invalid member template declaration %qD", decl);
300 return error_mark_node;
303 /* Create a template info node. */
306 build_template_info (tree template_decl, tree template_args)
308 tree result = make_node (TEMPLATE_INFO);
309 TI_TEMPLATE (result) = template_decl;
310 TI_ARGS (result) = template_args;
314 /* Return the template info node corresponding to T, whatever T is. */
317 get_template_info (const_tree t)
319 tree tinfo = NULL_TREE;
321 if (!t || t == error_mark_node)
324 if (DECL_P (t) && DECL_LANG_SPECIFIC (t))
325 tinfo = DECL_TEMPLATE_INFO (t);
327 if (!tinfo && DECL_IMPLICIT_TYPEDEF_P (t))
330 if (TAGGED_TYPE_P (t))
331 tinfo = TYPE_TEMPLATE_INFO (t);
332 else if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
333 tinfo = TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (t);
338 /* Returns the template nesting level of the indicated class TYPE.
348 A<T>::B<U> has depth two, while A<T> has depth one.
349 Both A<T>::B<int> and A<int>::B<U> have depth one, if
350 they are instantiations, not specializations.
352 This function is guaranteed to return 0 if passed NULL_TREE so
353 that, for example, `template_class_depth (current_class_type)' is
357 template_class_depth (tree type)
362 type && TREE_CODE (type) != NAMESPACE_DECL;
363 type = (TREE_CODE (type) == FUNCTION_DECL)
364 ? CP_DECL_CONTEXT (type) : CP_TYPE_CONTEXT (type))
366 tree tinfo = get_template_info (type);
368 if (tinfo && PRIMARY_TEMPLATE_P (TI_TEMPLATE (tinfo))
369 && uses_template_parms (INNERMOST_TEMPLATE_ARGS (TI_ARGS (tinfo))))
376 /* Subroutine of maybe_begin_member_template_processing.
377 Returns true if processing DECL needs us to push template parms. */
380 inline_needs_template_parms (tree decl)
382 if (! DECL_TEMPLATE_INFO (decl))
385 return (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (most_general_template (decl)))
386 > (processing_template_decl + DECL_TEMPLATE_SPECIALIZATION (decl)));
389 /* Subroutine of maybe_begin_member_template_processing.
390 Push the template parms in PARMS, starting from LEVELS steps into the
391 chain, and ending at the beginning, since template parms are listed
395 push_inline_template_parms_recursive (tree parmlist, int levels)
397 tree parms = TREE_VALUE (parmlist);
401 push_inline_template_parms_recursive (TREE_CHAIN (parmlist), levels - 1);
403 ++processing_template_decl;
404 current_template_parms
405 = tree_cons (size_int (processing_template_decl),
406 parms, current_template_parms);
407 TEMPLATE_PARMS_FOR_INLINE (current_template_parms) = 1;
409 begin_scope (TREE_VEC_LENGTH (parms) ? sk_template_parms : sk_template_spec,
411 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
413 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
415 if (parm == error_mark_node)
418 gcc_assert (DECL_P (parm));
420 switch (TREE_CODE (parm))
429 /* Make a CONST_DECL as is done in process_template_parm.
430 It is ugly that we recreate this here; the original
431 version built in process_template_parm is no longer
433 tree decl = build_decl (DECL_SOURCE_LOCATION (parm),
434 CONST_DECL, DECL_NAME (parm),
436 DECL_ARTIFICIAL (decl) = 1;
437 TREE_CONSTANT (decl) = 1;
438 TREE_READONLY (decl) = 1;
439 DECL_INITIAL (decl) = DECL_INITIAL (parm);
440 SET_DECL_TEMPLATE_PARM_P (decl);
451 /* Restore the template parameter context for a member template or
452 a friend template defined in a class definition. */
455 maybe_begin_member_template_processing (tree decl)
460 if (inline_needs_template_parms (decl))
462 parms = DECL_TEMPLATE_PARMS (most_general_template (decl));
463 levels = TMPL_PARMS_DEPTH (parms) - processing_template_decl;
465 if (DECL_TEMPLATE_SPECIALIZATION (decl))
468 parms = TREE_CHAIN (parms);
471 push_inline_template_parms_recursive (parms, levels);
474 /* Remember how many levels of template parameters we pushed so that
475 we can pop them later. */
476 VEC_safe_push (int, heap, inline_parm_levels, levels);
479 /* Undo the effects of maybe_begin_member_template_processing. */
482 maybe_end_member_template_processing (void)
487 if (VEC_length (int, inline_parm_levels) == 0)
490 last = VEC_pop (int, inline_parm_levels);
491 for (i = 0; i < last; ++i)
493 --processing_template_decl;
494 current_template_parms = TREE_CHAIN (current_template_parms);
499 /* Return a new template argument vector which contains all of ARGS,
500 but has as its innermost set of arguments the EXTRA_ARGS. */
503 add_to_template_args (tree args, tree extra_args)
510 if (args == NULL_TREE || extra_args == error_mark_node)
513 extra_depth = TMPL_ARGS_DEPTH (extra_args);
514 new_args = make_tree_vec (TMPL_ARGS_DEPTH (args) + extra_depth);
516 for (i = 1; i <= TMPL_ARGS_DEPTH (args); ++i)
517 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (args, i));
519 for (j = 1; j <= extra_depth; ++j, ++i)
520 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (extra_args, j));
525 /* Like add_to_template_args, but only the outermost ARGS are added to
526 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
527 (EXTRA_ARGS) levels are added. This function is used to combine
528 the template arguments from a partial instantiation with the
529 template arguments used to attain the full instantiation from the
530 partial instantiation. */
533 add_outermost_template_args (tree args, tree extra_args)
537 /* If there are more levels of EXTRA_ARGS than there are ARGS,
538 something very fishy is going on. */
539 gcc_assert (TMPL_ARGS_DEPTH (args) >= TMPL_ARGS_DEPTH (extra_args));
541 /* If *all* the new arguments will be the EXTRA_ARGS, just return
543 if (TMPL_ARGS_DEPTH (args) == TMPL_ARGS_DEPTH (extra_args))
546 /* For the moment, we make ARGS look like it contains fewer levels. */
547 TREE_VEC_LENGTH (args) -= TMPL_ARGS_DEPTH (extra_args);
549 new_args = add_to_template_args (args, extra_args);
551 /* Now, we restore ARGS to its full dimensions. */
552 TREE_VEC_LENGTH (args) += TMPL_ARGS_DEPTH (extra_args);
557 /* Return the N levels of innermost template arguments from the ARGS. */
560 get_innermost_template_args (tree args, int n)
568 /* If N is 1, just return the innermost set of template arguments. */
570 return TMPL_ARGS_LEVEL (args, TMPL_ARGS_DEPTH (args));
572 /* If we're not removing anything, just return the arguments we were
574 extra_levels = TMPL_ARGS_DEPTH (args) - n;
575 gcc_assert (extra_levels >= 0);
576 if (extra_levels == 0)
579 /* Make a new set of arguments, not containing the outer arguments. */
580 new_args = make_tree_vec (n);
581 for (i = 1; i <= n; ++i)
582 SET_TMPL_ARGS_LEVEL (new_args, i,
583 TMPL_ARGS_LEVEL (args, i + extra_levels));
588 /* The inverse of get_innermost_template_args: Return all but the innermost
589 EXTRA_LEVELS levels of template arguments from the ARGS. */
592 strip_innermost_template_args (tree args, int extra_levels)
595 int n = TMPL_ARGS_DEPTH (args) - extra_levels;
600 /* If N is 1, just return the outermost set of template arguments. */
602 return TMPL_ARGS_LEVEL (args, 1);
604 /* If we're not removing anything, just return the arguments we were
606 gcc_assert (extra_levels >= 0);
607 if (extra_levels == 0)
610 /* Make a new set of arguments, not containing the inner arguments. */
611 new_args = make_tree_vec (n);
612 for (i = 1; i <= n; ++i)
613 SET_TMPL_ARGS_LEVEL (new_args, i,
614 TMPL_ARGS_LEVEL (args, i));
619 /* We've got a template header coming up; push to a new level for storing
623 begin_template_parm_list (void)
625 /* We use a non-tag-transparent scope here, which causes pushtag to
626 put tags in this scope, rather than in the enclosing class or
627 namespace scope. This is the right thing, since we want
628 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
629 global template class, push_template_decl handles putting the
630 TEMPLATE_DECL into top-level scope. For a nested template class,
633 template <class T> struct S1 {
634 template <class T> struct S2 {};
637 pushtag contains special code to call pushdecl_with_scope on the
638 TEMPLATE_DECL for S2. */
639 begin_scope (sk_template_parms, NULL);
640 ++processing_template_decl;
641 ++processing_template_parmlist;
642 note_template_header (0);
645 /* This routine is called when a specialization is declared. If it is
646 invalid to declare a specialization here, an error is reported and
647 false is returned, otherwise this routine will return true. */
650 check_specialization_scope (void)
652 tree scope = current_scope ();
656 An explicit specialization shall be declared in the namespace of
657 which the template is a member, or, for member templates, in the
658 namespace of which the enclosing class or enclosing class
659 template is a member. An explicit specialization of a member
660 function, member class or static data member of a class template
661 shall be declared in the namespace of which the class template
663 if (scope && TREE_CODE (scope) != NAMESPACE_DECL)
665 error ("explicit specialization in non-namespace scope %qD", scope);
671 In an explicit specialization declaration for a member of a class
672 template or a member template that appears in namespace scope,
673 the member template and some of its enclosing class templates may
674 remain unspecialized, except that the declaration shall not
675 explicitly specialize a class member template if its enclosing
676 class templates are not explicitly specialized as well. */
677 if (current_template_parms)
679 error ("enclosing class templates are not explicitly specialized");
686 /* We've just seen template <>. */
689 begin_specialization (void)
691 begin_scope (sk_template_spec, NULL);
692 note_template_header (1);
693 return check_specialization_scope ();
696 /* Called at then end of processing a declaration preceded by
700 end_specialization (void)
703 reset_specialization ();
706 /* Any template <>'s that we have seen thus far are not referring to a
707 function specialization. */
710 reset_specialization (void)
712 processing_specialization = 0;
713 template_header_count = 0;
716 /* We've just seen a template header. If SPECIALIZATION is nonzero,
717 it was of the form template <>. */
720 note_template_header (int specialization)
722 processing_specialization = specialization;
723 template_header_count++;
726 /* We're beginning an explicit instantiation. */
729 begin_explicit_instantiation (void)
731 gcc_assert (!processing_explicit_instantiation);
732 processing_explicit_instantiation = true;
737 end_explicit_instantiation (void)
739 gcc_assert (processing_explicit_instantiation);
740 processing_explicit_instantiation = false;
743 /* An explicit specialization or partial specialization TMPL is being
744 declared. Check that the namespace in which the specialization is
745 occurring is permissible. Returns false iff it is invalid to
746 specialize TMPL in the current namespace. */
749 check_specialization_namespace (tree tmpl)
751 tree tpl_ns = decl_namespace_context (tmpl);
755 An explicit specialization shall be declared in the namespace of
756 which the template is a member, or, for member templates, in the
757 namespace of which the enclosing class or enclosing class
758 template is a member. An explicit specialization of a member
759 function, member class or static data member of a class template
760 shall be declared in the namespace of which the class template is
762 if (current_scope() != DECL_CONTEXT (tmpl)
763 && !at_namespace_scope_p ())
765 error ("specialization of %qD must appear at namespace scope", tmpl);
768 if (is_associated_namespace (current_namespace, tpl_ns))
769 /* Same or super-using namespace. */
773 permerror (input_location, "specialization of %qD in different namespace", tmpl);
774 permerror (input_location, " from definition of %q+#D", tmpl);
779 /* SPEC is an explicit instantiation. Check that it is valid to
780 perform this explicit instantiation in the current namespace. */
783 check_explicit_instantiation_namespace (tree spec)
787 /* DR 275: An explicit instantiation shall appear in an enclosing
788 namespace of its template. */
789 ns = decl_namespace_context (spec);
790 if (!is_ancestor (current_namespace, ns))
791 permerror (input_location, "explicit instantiation of %qD in namespace %qD "
792 "(which does not enclose namespace %qD)",
793 spec, current_namespace, ns);
796 /* The TYPE is being declared. If it is a template type, that means it
797 is a partial specialization. Do appropriate error-checking. */
800 maybe_process_partial_specialization (tree type)
804 if (type == error_mark_node)
805 return error_mark_node;
807 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
809 error ("name of class shadows template template parameter %qD",
811 return error_mark_node;
814 context = TYPE_CONTEXT (type);
816 if (CLASS_TYPE_P (type) && CLASSTYPE_USE_TEMPLATE (type))
818 /* This is for ordinary explicit specialization and partial
819 specialization of a template class such as:
821 template <> class C<int>;
825 template <class T> class C<T*>;
827 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
829 if (CLASSTYPE_IMPLICIT_INSTANTIATION (type)
830 && !COMPLETE_TYPE_P (type))
832 check_specialization_namespace (CLASSTYPE_TI_TEMPLATE (type));
833 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
834 if (processing_template_decl)
836 if (push_template_decl (TYPE_MAIN_DECL (type))
838 return error_mark_node;
841 else if (CLASSTYPE_TEMPLATE_INSTANTIATION (type))
842 error ("specialization of %qT after instantiation", type);
844 else if (CLASS_TYPE_P (type)
845 && !CLASSTYPE_USE_TEMPLATE (type)
846 && CLASSTYPE_TEMPLATE_INFO (type)
847 && context && CLASS_TYPE_P (context)
848 && CLASSTYPE_TEMPLATE_INFO (context))
850 /* This is for an explicit specialization of member class
851 template according to [temp.expl.spec/18]:
853 template <> template <class U> class C<int>::D;
855 The context `C<int>' must be an implicit instantiation.
856 Otherwise this is just a member class template declared
859 template <> class C<int> { template <class U> class D; };
860 template <> template <class U> class C<int>::D;
862 In the first case, `C<int>::D' is a specialization of `C<T>::D'
863 while in the second case, `C<int>::D' is a primary template
864 and `C<T>::D' may not exist. */
866 if (CLASSTYPE_IMPLICIT_INSTANTIATION (context)
867 && !COMPLETE_TYPE_P (type))
870 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
872 if (current_namespace
873 != decl_namespace_context (tmpl))
875 permerror (input_location, "specializing %q#T in different namespace", type);
876 permerror (input_location, " from definition of %q+#D", tmpl);
879 /* Check for invalid specialization after instantiation:
881 template <> template <> class C<int>::D<int>;
882 template <> template <class U> class C<int>::D; */
884 for (t = DECL_TEMPLATE_INSTANTIATIONS (tmpl);
885 t; t = TREE_CHAIN (t))
887 tree inst = TREE_VALUE (t);
888 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (inst))
890 /* We already have a full specialization of this partial
891 instantiation. Reassign it to the new member
892 specialization template. */
896 elt.tmpl = most_general_template (tmpl);
897 elt.args = CLASSTYPE_TI_ARGS (inst);
900 htab_remove_elt (type_specializations, &elt);
903 elt.args = INNERMOST_TEMPLATE_ARGS (elt.args);
905 slot = (spec_entry **)
906 htab_find_slot (type_specializations, &elt, INSERT);
907 *slot = ggc_alloc_spec_entry ();
910 else if (COMPLETE_OR_OPEN_TYPE_P (inst))
911 /* But if we've had an implicit instantiation, that's a
912 problem ([temp.expl.spec]/6). */
913 error ("specialization %qT after instantiation %qT",
917 /* Mark TYPE as a specialization. And as a result, we only
918 have one level of template argument for the innermost
920 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
921 CLASSTYPE_TI_ARGS (type)
922 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type));
925 else if (processing_specialization)
927 /* Someday C++0x may allow for enum template specialization. */
928 if (cxx_dialect > cxx98 && TREE_CODE (type) == ENUMERAL_TYPE
929 && CLASS_TYPE_P (context) && CLASSTYPE_USE_TEMPLATE (context))
930 pedwarn (input_location, OPT_pedantic, "template specialization "
931 "of %qD not allowed by ISO C++", type);
934 error ("explicit specialization of non-template %qT", type);
935 return error_mark_node;
942 /* Returns nonzero if we can optimize the retrieval of specializations
943 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
944 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
947 optimize_specialization_lookup_p (tree tmpl)
949 return (DECL_FUNCTION_TEMPLATE_P (tmpl)
950 && DECL_CLASS_SCOPE_P (tmpl)
951 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
953 && CLASS_TYPE_P (DECL_CONTEXT (tmpl))
954 /* The optimized lookup depends on the fact that the
955 template arguments for the member function template apply
956 purely to the containing class, which is not true if the
957 containing class is an explicit or partial
959 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (tmpl))
960 && !DECL_MEMBER_TEMPLATE_P (tmpl)
961 && !DECL_CONV_FN_P (tmpl)
962 /* It is possible to have a template that is not a member
963 template and is not a member of a template class:
965 template <typename T>
966 struct S { friend A::f(); };
968 Here, the friend function is a template, but the context does
969 not have template information. The optimized lookup relies
970 on having ARGS be the template arguments for both the class
971 and the function template. */
972 && !DECL_FRIEND_P (DECL_TEMPLATE_RESULT (tmpl)));
975 /* Retrieve the specialization (in the sense of [temp.spec] - a
976 specialization is either an instantiation or an explicit
977 specialization) of TMPL for the given template ARGS. If there is
978 no such specialization, return NULL_TREE. The ARGS are a vector of
979 arguments, or a vector of vectors of arguments, in the case of
980 templates with more than one level of parameters.
982 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
983 then we search for a partial specialization matching ARGS. This
984 parameter is ignored if TMPL is not a class template. */
987 retrieve_specialization (tree tmpl, tree args, hashval_t hash)
989 if (args == error_mark_node)
992 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
994 /* There should be as many levels of arguments as there are
995 levels of parameters. */
996 gcc_assert (TMPL_ARGS_DEPTH (args)
997 == TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl)));
999 if (optimize_specialization_lookup_p (tmpl))
1001 tree class_template;
1002 tree class_specialization;
1003 VEC(tree,gc) *methods;
1007 /* The template arguments actually apply to the containing
1008 class. Find the class specialization with those
1010 class_template = CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (tmpl));
1011 class_specialization
1012 = retrieve_specialization (class_template, args, 0);
1013 if (!class_specialization)
1015 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
1016 for the specialization. */
1017 idx = class_method_index_for_fn (class_specialization, tmpl);
1020 /* Iterate through the methods with the indicated name, looking
1021 for the one that has an instance of TMPL. */
1022 methods = CLASSTYPE_METHOD_VEC (class_specialization);
1023 for (fns = VEC_index (tree, methods, idx); fns; fns = OVL_NEXT (fns))
1025 tree fn = OVL_CURRENT (fns);
1026 if (DECL_TEMPLATE_INFO (fn) && DECL_TI_TEMPLATE (fn) == tmpl
1027 /* using-declarations can add base methods to the method vec,
1028 and we don't want those here. */
1029 && DECL_CONTEXT (fn) == class_specialization)
1038 htab_t specializations;
1042 elt.spec = NULL_TREE;
1044 if (DECL_CLASS_TEMPLATE_P (tmpl))
1045 specializations = type_specializations;
1047 specializations = decl_specializations;
1050 hash = hash_specialization (&elt);
1051 found = (spec_entry *) htab_find_with_hash (specializations, &elt, hash);
1059 /* Like retrieve_specialization, but for local declarations. */
1062 retrieve_local_specialization (tree tmpl)
1066 if (local_specializations == NULL)
1069 spec = (tree) htab_find_with_hash (local_specializations, tmpl,
1070 htab_hash_pointer (tmpl));
1071 return spec ? TREE_PURPOSE (spec) : NULL_TREE;
1074 /* Returns nonzero iff DECL is a specialization of TMPL. */
1077 is_specialization_of (tree decl, tree tmpl)
1081 if (TREE_CODE (decl) == FUNCTION_DECL)
1085 t = DECL_TEMPLATE_INFO (t) ? DECL_TI_TEMPLATE (t) : NULL_TREE)
1091 gcc_assert (TREE_CODE (decl) == TYPE_DECL);
1093 for (t = TREE_TYPE (decl);
1095 t = CLASSTYPE_USE_TEMPLATE (t)
1096 ? TREE_TYPE (CLASSTYPE_TI_TEMPLATE (t)) : NULL_TREE)
1097 if (same_type_ignoring_top_level_qualifiers_p (t, TREE_TYPE (tmpl)))
1104 /* Returns nonzero iff DECL is a specialization of friend declaration
1105 FRIEND_DECL according to [temp.friend]. */
1108 is_specialization_of_friend (tree decl, tree friend_decl)
1110 bool need_template = true;
1113 gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
1114 || TREE_CODE (decl) == TYPE_DECL);
1116 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1117 of a template class, we want to check if DECL is a specialization
1119 if (TREE_CODE (friend_decl) == FUNCTION_DECL
1120 && DECL_TEMPLATE_INFO (friend_decl)
1121 && !DECL_USE_TEMPLATE (friend_decl))
1123 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1124 friend_decl = DECL_TI_TEMPLATE (friend_decl);
1125 need_template = false;
1127 else if (TREE_CODE (friend_decl) == TEMPLATE_DECL
1128 && !PRIMARY_TEMPLATE_P (friend_decl))
1129 need_template = false;
1131 /* There is nothing to do if this is not a template friend. */
1132 if (TREE_CODE (friend_decl) != TEMPLATE_DECL)
1135 if (is_specialization_of (decl, friend_decl))
1139 A member of a class template may be declared to be a friend of a
1140 non-template class. In this case, the corresponding member of
1141 every specialization of the class template is a friend of the
1142 class granting friendship.
1144 For example, given a template friend declaration
1146 template <class T> friend void A<T>::f();
1148 the member function below is considered a friend
1150 template <> struct A<int> {
1154 For this type of template friend, TEMPLATE_DEPTH below will be
1155 nonzero. To determine if DECL is a friend of FRIEND, we first
1156 check if the enclosing class is a specialization of another. */
1158 template_depth = template_class_depth (CP_DECL_CONTEXT (friend_decl));
1160 && DECL_CLASS_SCOPE_P (decl)
1161 && is_specialization_of (TYPE_NAME (DECL_CONTEXT (decl)),
1162 CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (friend_decl))))
1164 /* Next, we check the members themselves. In order to handle
1165 a few tricky cases, such as when FRIEND_DECL's are
1167 template <class T> friend void A<T>::g(T t);
1168 template <class T> template <T t> friend void A<T>::h();
1172 void A<int>::g(int);
1173 template <int> void A<int>::h();
1175 we need to figure out ARGS, the template arguments from
1176 the context of DECL. This is required for template substitution
1177 of `T' in the function parameter of `g' and template parameter
1178 of `h' in the above examples. Here ARGS corresponds to `int'. */
1180 tree context = DECL_CONTEXT (decl);
1181 tree args = NULL_TREE;
1182 int current_depth = 0;
1184 while (current_depth < template_depth)
1186 if (CLASSTYPE_TEMPLATE_INFO (context))
1188 if (current_depth == 0)
1189 args = TYPE_TI_ARGS (context);
1191 args = add_to_template_args (TYPE_TI_ARGS (context), args);
1194 context = TYPE_CONTEXT (context);
1197 if (TREE_CODE (decl) == FUNCTION_DECL)
1202 tree friend_args_type;
1203 tree decl_args_type;
1205 /* Make sure that both DECL and FRIEND_DECL are templates or
1207 is_template = DECL_TEMPLATE_INFO (decl)
1208 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (decl));
1209 if (need_template ^ is_template)
1211 else if (is_template)
1213 /* If both are templates, check template parameter list. */
1215 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1217 if (!comp_template_parms
1218 (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (decl)),
1222 decl_type = TREE_TYPE (DECL_TI_TEMPLATE (decl));
1225 decl_type = TREE_TYPE (decl);
1227 friend_type = tsubst_function_type (TREE_TYPE (friend_decl), args,
1228 tf_none, NULL_TREE);
1229 if (friend_type == error_mark_node)
1232 /* Check if return types match. */
1233 if (!same_type_p (TREE_TYPE (decl_type), TREE_TYPE (friend_type)))
1236 /* Check if function parameter types match, ignoring the
1237 `this' parameter. */
1238 friend_args_type = TYPE_ARG_TYPES (friend_type);
1239 decl_args_type = TYPE_ARG_TYPES (decl_type);
1240 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (friend_decl))
1241 friend_args_type = TREE_CHAIN (friend_args_type);
1242 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1243 decl_args_type = TREE_CHAIN (decl_args_type);
1245 return compparms (decl_args_type, friend_args_type);
1249 /* DECL is a TYPE_DECL */
1251 tree decl_type = TREE_TYPE (decl);
1253 /* Make sure that both DECL and FRIEND_DECL are templates or
1256 = CLASSTYPE_TEMPLATE_INFO (decl_type)
1257 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (decl_type));
1259 if (need_template ^ is_template)
1261 else if (is_template)
1264 /* If both are templates, check the name of the two
1265 TEMPLATE_DECL's first because is_friend didn't. */
1266 if (DECL_NAME (CLASSTYPE_TI_TEMPLATE (decl_type))
1267 != DECL_NAME (friend_decl))
1270 /* Now check template parameter list. */
1272 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1274 return comp_template_parms
1275 (DECL_TEMPLATE_PARMS (CLASSTYPE_TI_TEMPLATE (decl_type)),
1279 return (DECL_NAME (decl)
1280 == DECL_NAME (friend_decl));
1286 /* Register the specialization SPEC as a specialization of TMPL with
1287 the indicated ARGS. IS_FRIEND indicates whether the specialization
1288 is actually just a friend declaration. Returns SPEC, or an
1289 equivalent prior declaration, if available. */
1292 register_specialization (tree spec, tree tmpl, tree args, bool is_friend,
1296 spec_entry **slot = NULL;
1299 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL && DECL_P (spec));
1301 if (TREE_CODE (spec) == FUNCTION_DECL
1302 && uses_template_parms (DECL_TI_ARGS (spec)))
1303 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1304 register it; we want the corresponding TEMPLATE_DECL instead.
1305 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1306 the more obvious `uses_template_parms (spec)' to avoid problems
1307 with default function arguments. In particular, given
1308 something like this:
1310 template <class T> void f(T t1, T t = T())
1312 the default argument expression is not substituted for in an
1313 instantiation unless and until it is actually needed. */
1316 if (optimize_specialization_lookup_p (tmpl))
1317 /* We don't put these specializations in the hash table, but we might
1318 want to give an error about a mismatch. */
1319 fn = retrieve_specialization (tmpl, args, 0);
1327 hash = hash_specialization (&elt);
1329 slot = (spec_entry **)
1330 htab_find_slot_with_hash (decl_specializations, &elt, hash, INSERT);
1337 /* We can sometimes try to re-register a specialization that we've
1338 already got. In particular, regenerate_decl_from_template calls
1339 duplicate_decls which will update the specialization list. But,
1340 we'll still get called again here anyhow. It's more convenient
1341 to simply allow this than to try to prevent it. */
1344 else if (fn && DECL_TEMPLATE_SPECIALIZATION (spec))
1346 if (DECL_TEMPLATE_INSTANTIATION (fn))
1348 if (DECL_ODR_USED (fn)
1349 || DECL_EXPLICIT_INSTANTIATION (fn))
1351 error ("specialization of %qD after instantiation",
1353 return error_mark_node;
1358 /* This situation should occur only if the first
1359 specialization is an implicit instantiation, the
1360 second is an explicit specialization, and the
1361 implicit instantiation has not yet been used. That
1362 situation can occur if we have implicitly
1363 instantiated a member function and then specialized
1366 We can also wind up here if a friend declaration that
1367 looked like an instantiation turns out to be a
1370 template <class T> void foo(T);
1371 class S { friend void foo<>(int) };
1372 template <> void foo(int);
1374 We transform the existing DECL in place so that any
1375 pointers to it become pointers to the updated
1378 If there was a definition for the template, but not
1379 for the specialization, we want this to look as if
1380 there were no definition, and vice versa. */
1381 DECL_INITIAL (fn) = NULL_TREE;
1382 duplicate_decls (spec, fn, is_friend);
1383 /* The call to duplicate_decls will have applied
1386 An explicit specialization of a function template
1387 is inline only if it is explicitly declared to be,
1388 and independently of whether its function template
1391 to the primary function; now copy the inline bits to
1392 the various clones. */
1393 FOR_EACH_CLONE (clone, fn)
1395 DECL_DECLARED_INLINE_P (clone)
1396 = DECL_DECLARED_INLINE_P (fn);
1397 DECL_SOURCE_LOCATION (clone)
1398 = DECL_SOURCE_LOCATION (fn);
1400 check_specialization_namespace (fn);
1405 else if (DECL_TEMPLATE_SPECIALIZATION (fn))
1407 if (!duplicate_decls (spec, fn, is_friend) && DECL_INITIAL (spec))
1408 /* Dup decl failed, but this is a new definition. Set the
1409 line number so any errors match this new
1411 DECL_SOURCE_LOCATION (fn) = DECL_SOURCE_LOCATION (spec);
1417 return duplicate_decls (spec, fn, is_friend);
1419 /* A specialization must be declared in the same namespace as the
1420 template it is specializing. */
1421 if (DECL_TEMPLATE_SPECIALIZATION (spec)
1422 && !check_specialization_namespace (tmpl))
1423 DECL_CONTEXT (spec) = DECL_CONTEXT (tmpl);
1425 if (!optimize_specialization_lookup_p (tmpl))
1427 gcc_assert (tmpl && args && spec);
1428 *slot = ggc_alloc_spec_entry ();
1430 if (TREE_CODE (spec) == FUNCTION_DECL && DECL_NAMESPACE_SCOPE_P (spec)
1431 && PRIMARY_TEMPLATE_P (tmpl)
1432 && DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (tmpl)) == NULL_TREE)
1433 /* TMPL is a forward declaration of a template function; keep a list
1434 of all specializations in case we need to reassign them to a friend
1435 template later in tsubst_friend_function. */
1436 DECL_TEMPLATE_INSTANTIATIONS (tmpl)
1437 = tree_cons (args, spec, DECL_TEMPLATE_INSTANTIATIONS (tmpl));
1443 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1444 TMPL and ARGS members, ignores SPEC. */
1447 eq_specializations (const void *p1, const void *p2)
1449 const spec_entry *e1 = (const spec_entry *)p1;
1450 const spec_entry *e2 = (const spec_entry *)p2;
1452 return (e1->tmpl == e2->tmpl
1453 && comp_template_args (e1->args, e2->args));
1456 /* Returns a hash for a template TMPL and template arguments ARGS. */
1459 hash_tmpl_and_args (tree tmpl, tree args)
1461 hashval_t val = DECL_UID (tmpl);
1462 return iterative_hash_template_arg (args, val);
1465 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1469 hash_specialization (const void *p)
1471 const spec_entry *e = (const spec_entry *)p;
1472 return hash_tmpl_and_args (e->tmpl, e->args);
1475 /* Recursively calculate a hash value for a template argument ARG, for use
1476 in the hash tables of template specializations. */
1479 iterative_hash_template_arg (tree arg, hashval_t val)
1481 unsigned HOST_WIDE_INT i;
1482 enum tree_code code;
1485 if (arg == NULL_TREE)
1486 return iterative_hash_object (arg, val);
1491 if (TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
1492 /* We can get one of these when re-hashing a previous entry in the middle
1493 of substituting into a pack expansion. Just look through it. */
1494 arg = ARGUMENT_PACK_SELECT_FROM_PACK (arg);
1496 code = TREE_CODE (arg);
1497 tclass = TREE_CODE_CLASS (code);
1499 val = iterative_hash_object (code, val);
1506 case IDENTIFIER_NODE:
1507 return iterative_hash_object (IDENTIFIER_HASH_VALUE (arg), val);
1511 int i, len = TREE_VEC_LENGTH (arg);
1512 for (i = 0; i < len; ++i)
1513 val = iterative_hash_template_arg (TREE_VEC_ELT (arg, i), val);
1517 case TYPE_PACK_EXPANSION:
1518 case EXPR_PACK_EXPANSION:
1519 return iterative_hash_template_arg (PACK_EXPANSION_PATTERN (arg), val);
1521 case TYPE_ARGUMENT_PACK:
1522 case NONTYPE_ARGUMENT_PACK:
1523 return iterative_hash_template_arg (ARGUMENT_PACK_ARGS (arg), val);
1526 for (; arg; arg = TREE_CHAIN (arg))
1527 val = iterative_hash_template_arg (TREE_VALUE (arg), val);
1531 for (; arg; arg = OVL_NEXT (arg))
1532 val = iterative_hash_template_arg (OVL_CURRENT (arg), val);
1538 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg), i, field, value)
1540 val = iterative_hash_template_arg (field, val);
1541 val = iterative_hash_template_arg (value, val);
1547 if (!DECL_ARTIFICIAL (arg))
1549 val = iterative_hash_object (DECL_PARM_INDEX (arg), val);
1550 val = iterative_hash_object (DECL_PARM_LEVEL (arg), val);
1552 return iterative_hash_template_arg (TREE_TYPE (arg), val);
1555 return iterative_hash_template_arg (TARGET_EXPR_INITIAL (arg), val);
1558 val = iterative_hash_template_arg (PTRMEM_CST_CLASS (arg), val);
1559 return iterative_hash_template_arg (PTRMEM_CST_MEMBER (arg), val);
1561 case TEMPLATE_PARM_INDEX:
1562 val = iterative_hash_template_arg
1563 (TREE_TYPE (TEMPLATE_PARM_DECL (arg)), val);
1564 val = iterative_hash_object (TEMPLATE_PARM_LEVEL (arg), val);
1565 return iterative_hash_object (TEMPLATE_PARM_IDX (arg), val);
1568 val = iterative_hash_object (TRAIT_EXPR_KIND (arg), val);
1569 val = iterative_hash_template_arg (TRAIT_EXPR_TYPE1 (arg), val);
1570 return iterative_hash_template_arg (TRAIT_EXPR_TYPE2 (arg), val);
1573 val = iterative_hash_template_arg (BINFO_TYPE (BASELINK_BINFO (arg)),
1575 return iterative_hash_template_arg (DECL_NAME (get_first_fn (arg)),
1579 val = iterative_hash_template_arg (TREE_OPERAND (arg, 0), val);
1580 code = TREE_CODE (TREE_OPERAND (arg, 1));
1581 val = iterative_hash_object (code, val);
1582 return iterative_hash_template_arg (TREE_OPERAND (arg, 2), val);
1585 /* A lambda can't appear in a template arg, but don't crash on
1587 gcc_assert (seen_error ());
1591 case STATIC_CAST_EXPR:
1592 case REINTERPRET_CAST_EXPR:
1593 case CONST_CAST_EXPR:
1594 case DYNAMIC_CAST_EXPR:
1596 val = iterative_hash_template_arg (TREE_TYPE (arg), val);
1597 /* Now hash operands as usual. */
1607 if (TYPE_CANONICAL (arg))
1608 return iterative_hash_object (TYPE_HASH (TYPE_CANONICAL (arg)),
1610 else if (TREE_CODE (arg) == DECLTYPE_TYPE)
1611 return iterative_hash_template_arg (DECLTYPE_TYPE_EXPR (arg), val);
1612 /* Otherwise just compare the types during lookup. */
1615 case tcc_declaration:
1617 return iterative_hash_expr (arg, val);
1620 gcc_assert (IS_EXPR_CODE_CLASS (tclass));
1622 unsigned n = cp_tree_operand_length (arg);
1623 for (i = 0; i < n; ++i)
1624 val = iterative_hash_template_arg (TREE_OPERAND (arg, i), val);
1632 /* Unregister the specialization SPEC as a specialization of TMPL.
1633 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1634 if the SPEC was listed as a specialization of TMPL.
1636 Note that SPEC has been ggc_freed, so we can't look inside it. */
1639 reregister_specialization (tree spec, tree tinfo, tree new_spec)
1644 elt.tmpl = most_general_template (TI_TEMPLATE (tinfo));
1645 elt.args = TI_ARGS (tinfo);
1646 elt.spec = NULL_TREE;
1648 slot = (spec_entry **) htab_find_slot (decl_specializations, &elt, INSERT);
1651 gcc_assert ((*slot)->spec == spec || (*slot)->spec == new_spec);
1652 gcc_assert (new_spec != NULL_TREE);
1653 (*slot)->spec = new_spec;
1660 /* Compare an entry in the local specializations hash table P1 (which
1661 is really a pointer to a TREE_LIST) with P2 (which is really a
1665 eq_local_specializations (const void *p1, const void *p2)
1667 return TREE_VALUE ((const_tree) p1) == (const_tree) p2;
1670 /* Hash P1, an entry in the local specializations table. */
1673 hash_local_specialization (const void* p1)
1675 return htab_hash_pointer (TREE_VALUE ((const_tree) p1));
1678 /* Like register_specialization, but for local declarations. We are
1679 registering SPEC, an instantiation of TMPL. */
1682 register_local_specialization (tree spec, tree tmpl)
1686 slot = htab_find_slot_with_hash (local_specializations, tmpl,
1687 htab_hash_pointer (tmpl), INSERT);
1688 *slot = build_tree_list (spec, tmpl);
1691 /* TYPE is a class type. Returns true if TYPE is an explicitly
1692 specialized class. */
1695 explicit_class_specialization_p (tree type)
1697 if (!CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
1699 return !uses_template_parms (CLASSTYPE_TI_ARGS (type));
1702 /* Print the list of functions at FNS, going through all the overloads
1703 for each element of the list. Alternatively, FNS can not be a
1704 TREE_LIST, in which case it will be printed together with all the
1707 MORE and *STR should respectively be FALSE and NULL when the function
1708 is called from the outside. They are used internally on recursive
1709 calls. print_candidates manages the two parameters and leaves NULL
1710 in *STR when it ends. */
1713 print_candidates_1 (tree fns, bool more, const char **str)
1716 char *spaces = NULL;
1718 for (fn = fns; fn; fn = OVL_NEXT (fn))
1719 if (TREE_CODE (fn) == TREE_LIST)
1721 for (fn2 = fn; fn2 != NULL_TREE; fn2 = TREE_CHAIN (fn2))
1722 print_candidates_1 (TREE_VALUE (fn2),
1723 TREE_CHAIN (fn2) || more, str);
1729 /* Pick the prefix string. */
1730 if (!more && !OVL_NEXT (fns))
1732 error ("candidate is: %+#D", OVL_CURRENT (fn));
1736 *str = _("candidates are:");
1737 spaces = get_spaces (*str);
1739 error ("%s %+#D", *str, OVL_CURRENT (fn));
1740 *str = spaces ? spaces : *str;
1750 /* Print the list of candidate FNS in an error message. FNS can also
1751 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1754 print_candidates (tree fns)
1756 const char *str = NULL;
1757 print_candidates_1 (fns, false, &str);
1758 gcc_assert (str == NULL);
1761 /* Returns the template (one of the functions given by TEMPLATE_ID)
1762 which can be specialized to match the indicated DECL with the
1763 explicit template args given in TEMPLATE_ID. The DECL may be
1764 NULL_TREE if none is available. In that case, the functions in
1765 TEMPLATE_ID are non-members.
1767 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1768 specialization of a member template.
1770 The TEMPLATE_COUNT is the number of references to qualifying
1771 template classes that appeared in the name of the function. See
1772 check_explicit_specialization for a more accurate description.
1774 TSK indicates what kind of template declaration (if any) is being
1775 declared. TSK_TEMPLATE indicates that the declaration given by
1776 DECL, though a FUNCTION_DECL, has template parameters, and is
1777 therefore a template function.
1779 The template args (those explicitly specified and those deduced)
1780 are output in a newly created vector *TARGS_OUT.
1782 If it is impossible to determine the result, an error message is
1783 issued. The error_mark_node is returned to indicate failure. */
1786 determine_specialization (tree template_id,
1789 int need_member_template,
1795 tree explicit_targs;
1796 tree candidates = NULL_TREE;
1797 /* A TREE_LIST of templates of which DECL may be a specialization.
1798 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1799 corresponding TREE_PURPOSE is the set of template arguments that,
1800 when used to instantiate the template, would produce a function
1801 with the signature of DECL. */
1802 tree templates = NULL_TREE;
1804 cp_binding_level *b;
1806 *targs_out = NULL_TREE;
1808 if (template_id == error_mark_node || decl == error_mark_node)
1809 return error_mark_node;
1811 fns = TREE_OPERAND (template_id, 0);
1812 explicit_targs = TREE_OPERAND (template_id, 1);
1814 if (fns == error_mark_node)
1815 return error_mark_node;
1817 /* Check for baselinks. */
1818 if (BASELINK_P (fns))
1819 fns = BASELINK_FUNCTIONS (fns);
1821 if (!is_overloaded_fn (fns))
1823 error ("%qD is not a function template", fns);
1824 return error_mark_node;
1827 /* Count the number of template headers specified for this
1830 for (b = current_binding_level;
1831 b->kind == sk_template_parms;
1835 for (; fns; fns = OVL_NEXT (fns))
1837 tree fn = OVL_CURRENT (fns);
1839 if (TREE_CODE (fn) == TEMPLATE_DECL)
1841 tree decl_arg_types;
1844 /* In case of explicit specialization, we need to check if
1845 the number of template headers appearing in the specialization
1846 is correct. This is usually done in check_explicit_specialization,
1847 but the check done there cannot be exhaustive when specializing
1848 member functions. Consider the following code:
1850 template <> void A<int>::f(int);
1851 template <> template <> void A<int>::f(int);
1853 Assuming that A<int> is not itself an explicit specialization
1854 already, the first line specializes "f" which is a non-template
1855 member function, whilst the second line specializes "f" which
1856 is a template member function. So both lines are syntactically
1857 correct, and check_explicit_specialization does not reject
1860 Here, we can do better, as we are matching the specialization
1861 against the declarations. We count the number of template
1862 headers, and we check if they match TEMPLATE_COUNT + 1
1863 (TEMPLATE_COUNT is the number of qualifying template classes,
1864 plus there must be another header for the member template
1867 Notice that if header_count is zero, this is not a
1868 specialization but rather a template instantiation, so there
1869 is no check we can perform here. */
1870 if (header_count && header_count != template_count + 1)
1873 /* Check that the number of template arguments at the
1874 innermost level for DECL is the same as for FN. */
1875 if (current_binding_level->kind == sk_template_parms
1876 && !current_binding_level->explicit_spec_p
1877 && (TREE_VEC_LENGTH (DECL_INNERMOST_TEMPLATE_PARMS (fn))
1878 != TREE_VEC_LENGTH (INNERMOST_TEMPLATE_PARMS
1879 (current_template_parms))))
1882 /* DECL might be a specialization of FN. */
1883 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1884 fn_arg_types = TYPE_ARG_TYPES (TREE_TYPE (fn));
1886 /* For a non-static member function, we need to make sure
1887 that the const qualification is the same. Since
1888 get_bindings does not try to merge the "this" parameter,
1889 we must do the comparison explicitly. */
1890 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
1891 && !same_type_p (TREE_VALUE (fn_arg_types),
1892 TREE_VALUE (decl_arg_types)))
1895 /* Skip the "this" parameter and, for constructors of
1896 classes with virtual bases, the VTT parameter. A
1897 full specialization of a constructor will have a VTT
1898 parameter, but a template never will. */
1900 = skip_artificial_parms_for (decl, decl_arg_types);
1902 = skip_artificial_parms_for (fn, fn_arg_types);
1904 /* Check that the number of function parameters matches.
1906 template <class T> void f(int i = 0);
1907 template <> void f<int>();
1908 The specialization f<int> is invalid but is not caught
1909 by get_bindings below. */
1910 if (list_length (fn_arg_types) != list_length (decl_arg_types))
1913 /* Function templates cannot be specializations; there are
1914 no partial specializations of functions. Therefore, if
1915 the type of DECL does not match FN, there is no
1917 if (tsk == tsk_template)
1919 if (compparms (fn_arg_types, decl_arg_types))
1920 candidates = tree_cons (NULL_TREE, fn, candidates);
1924 /* See whether this function might be a specialization of this
1926 targs = get_bindings (fn, decl, explicit_targs, /*check_ret=*/true);
1929 /* We cannot deduce template arguments that when used to
1930 specialize TMPL will produce DECL. */
1933 /* Save this template, and the arguments deduced. */
1934 templates = tree_cons (targs, fn, templates);
1936 else if (need_member_template)
1937 /* FN is an ordinary member function, and we need a
1938 specialization of a member template. */
1940 else if (TREE_CODE (fn) != FUNCTION_DECL)
1941 /* We can get IDENTIFIER_NODEs here in certain erroneous
1944 else if (!DECL_FUNCTION_MEMBER_P (fn))
1945 /* This is just an ordinary non-member function. Nothing can
1946 be a specialization of that. */
1948 else if (DECL_ARTIFICIAL (fn))
1949 /* Cannot specialize functions that are created implicitly. */
1953 tree decl_arg_types;
1955 /* This is an ordinary member function. However, since
1956 we're here, we can assume it's enclosing class is a
1957 template class. For example,
1959 template <typename T> struct S { void f(); };
1960 template <> void S<int>::f() {}
1962 Here, S<int>::f is a non-template, but S<int> is a
1963 template class. If FN has the same type as DECL, we
1964 might be in business. */
1966 if (!DECL_TEMPLATE_INFO (fn))
1967 /* Its enclosing class is an explicit specialization
1968 of a template class. This is not a candidate. */
1971 if (!same_type_p (TREE_TYPE (TREE_TYPE (decl)),
1972 TREE_TYPE (TREE_TYPE (fn))))
1973 /* The return types differ. */
1976 /* Adjust the type of DECL in case FN is a static member. */
1977 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1978 if (DECL_STATIC_FUNCTION_P (fn)
1979 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1980 decl_arg_types = TREE_CHAIN (decl_arg_types);
1982 if (compparms (TYPE_ARG_TYPES (TREE_TYPE (fn)),
1985 candidates = tree_cons (NULL_TREE, fn, candidates);
1989 if (templates && TREE_CHAIN (templates))
1995 It is possible for a specialization with a given function
1996 signature to be instantiated from more than one function
1997 template. In such cases, explicit specification of the
1998 template arguments must be used to uniquely identify the
1999 function template specialization being specialized.
2001 Note that here, there's no suggestion that we're supposed to
2002 determine which of the candidate templates is most
2003 specialized. However, we, also have:
2007 Partial ordering of overloaded function template
2008 declarations is used in the following contexts to select
2009 the function template to which a function template
2010 specialization refers:
2012 -- when an explicit specialization refers to a function
2015 So, we do use the partial ordering rules, at least for now.
2016 This extension can only serve to make invalid programs valid,
2017 so it's safe. And, there is strong anecdotal evidence that
2018 the committee intended the partial ordering rules to apply;
2019 the EDG front end has that behavior, and John Spicer claims
2020 that the committee simply forgot to delete the wording in
2021 [temp.expl.spec]. */
2022 tree tmpl = most_specialized_instantiation (templates);
2023 if (tmpl != error_mark_node)
2026 TREE_CHAIN (templates) = NULL_TREE;
2030 if (templates == NULL_TREE && candidates == NULL_TREE)
2032 error ("template-id %qD for %q+D does not match any template "
2033 "declaration", template_id, decl);
2034 if (header_count && header_count != template_count + 1)
2035 inform (input_location, "saw %d %<template<>%>, need %d for "
2036 "specializing a member function template",
2037 header_count, template_count + 1);
2038 return error_mark_node;
2040 else if ((templates && TREE_CHAIN (templates))
2041 || (candidates && TREE_CHAIN (candidates))
2042 || (templates && candidates))
2044 error ("ambiguous template specialization %qD for %q+D",
2046 candidates = chainon (candidates, templates);
2047 print_candidates (candidates);
2048 return error_mark_node;
2051 /* We have one, and exactly one, match. */
2054 tree fn = TREE_VALUE (candidates);
2055 *targs_out = copy_node (DECL_TI_ARGS (fn));
2056 /* DECL is a re-declaration or partial instantiation of a template
2058 if (TREE_CODE (fn) == TEMPLATE_DECL)
2060 /* It was a specialization of an ordinary member function in a
2062 return DECL_TI_TEMPLATE (fn);
2065 /* It was a specialization of a template. */
2066 targs = DECL_TI_ARGS (DECL_TEMPLATE_RESULT (TREE_VALUE (templates)));
2067 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (targs))
2069 *targs_out = copy_node (targs);
2070 SET_TMPL_ARGS_LEVEL (*targs_out,
2071 TMPL_ARGS_DEPTH (*targs_out),
2072 TREE_PURPOSE (templates));
2075 *targs_out = TREE_PURPOSE (templates);
2076 return TREE_VALUE (templates);
2079 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2080 but with the default argument values filled in from those in the
2084 copy_default_args_to_explicit_spec_1 (tree spec_types,
2087 tree new_spec_types;
2092 if (spec_types == void_list_node)
2093 return void_list_node;
2095 /* Substitute into the rest of the list. */
2097 copy_default_args_to_explicit_spec_1 (TREE_CHAIN (spec_types),
2098 TREE_CHAIN (tmpl_types));
2100 /* Add the default argument for this parameter. */
2101 return hash_tree_cons (TREE_PURPOSE (tmpl_types),
2102 TREE_VALUE (spec_types),
2106 /* DECL is an explicit specialization. Replicate default arguments
2107 from the template it specializes. (That way, code like:
2109 template <class T> void f(T = 3);
2110 template <> void f(double);
2113 works, as required.) An alternative approach would be to look up
2114 the correct default arguments at the call-site, but this approach
2115 is consistent with how implicit instantiations are handled. */
2118 copy_default_args_to_explicit_spec (tree decl)
2123 tree new_spec_types;
2127 tree object_type = NULL_TREE;
2128 tree in_charge = NULL_TREE;
2129 tree vtt = NULL_TREE;
2131 /* See if there's anything we need to do. */
2132 tmpl = DECL_TI_TEMPLATE (decl);
2133 tmpl_types = TYPE_ARG_TYPES (TREE_TYPE (DECL_TEMPLATE_RESULT (tmpl)));
2134 for (t = tmpl_types; t; t = TREE_CHAIN (t))
2135 if (TREE_PURPOSE (t))
2140 old_type = TREE_TYPE (decl);
2141 spec_types = TYPE_ARG_TYPES (old_type);
2143 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2145 /* Remove the this pointer, but remember the object's type for
2147 object_type = TREE_TYPE (TREE_VALUE (spec_types));
2148 spec_types = TREE_CHAIN (spec_types);
2149 tmpl_types = TREE_CHAIN (tmpl_types);
2151 if (DECL_HAS_IN_CHARGE_PARM_P (decl))
2153 /* DECL may contain more parameters than TMPL due to the extra
2154 in-charge parameter in constructors and destructors. */
2155 in_charge = spec_types;
2156 spec_types = TREE_CHAIN (spec_types);
2158 if (DECL_HAS_VTT_PARM_P (decl))
2161 spec_types = TREE_CHAIN (spec_types);
2165 /* Compute the merged default arguments. */
2167 copy_default_args_to_explicit_spec_1 (spec_types, tmpl_types);
2169 /* Compute the new FUNCTION_TYPE. */
2173 new_spec_types = hash_tree_cons (TREE_PURPOSE (vtt),
2178 /* Put the in-charge parameter back. */
2179 new_spec_types = hash_tree_cons (TREE_PURPOSE (in_charge),
2180 TREE_VALUE (in_charge),
2183 new_type = build_method_type_directly (object_type,
2184 TREE_TYPE (old_type),
2188 new_type = build_function_type (TREE_TYPE (old_type),
2190 new_type = cp_build_type_attribute_variant (new_type,
2191 TYPE_ATTRIBUTES (old_type));
2192 new_type = build_exception_variant (new_type,
2193 TYPE_RAISES_EXCEPTIONS (old_type));
2194 TREE_TYPE (decl) = new_type;
2197 /* Check to see if the function just declared, as indicated in
2198 DECLARATOR, and in DECL, is a specialization of a function
2199 template. We may also discover that the declaration is an explicit
2200 instantiation at this point.
2202 Returns DECL, or an equivalent declaration that should be used
2203 instead if all goes well. Issues an error message if something is
2204 amiss. Returns error_mark_node if the error is not easily
2207 FLAGS is a bitmask consisting of the following flags:
2209 2: The function has a definition.
2210 4: The function is a friend.
2212 The TEMPLATE_COUNT is the number of references to qualifying
2213 template classes that appeared in the name of the function. For
2216 template <class T> struct S { void f(); };
2219 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2220 classes are not counted in the TEMPLATE_COUNT, so that in
2222 template <class T> struct S {};
2223 template <> struct S<int> { void f(); }
2224 template <> void S<int>::f();
2226 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2227 invalid; there should be no template <>.)
2229 If the function is a specialization, it is marked as such via
2230 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2231 is set up correctly, and it is added to the list of specializations
2232 for that template. */
2235 check_explicit_specialization (tree declarator,
2240 int have_def = flags & 2;
2241 int is_friend = flags & 4;
2242 int specialization = 0;
2243 int explicit_instantiation = 0;
2244 int member_specialization = 0;
2245 tree ctype = DECL_CLASS_CONTEXT (decl);
2246 tree dname = DECL_NAME (decl);
2251 if (!processing_specialization)
2254 tsk = tsk_excessive_parms;
2257 tsk = current_tmpl_spec_kind (template_count);
2262 if (processing_specialization)
2265 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2267 else if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2270 /* This could be something like:
2272 template <class T> void f(T);
2273 class S { friend void f<>(int); } */
2277 /* This case handles bogus declarations like template <>
2278 template <class T> void f<int>(); */
2280 error ("template-id %qD in declaration of primary template",
2287 case tsk_invalid_member_spec:
2288 /* The error has already been reported in
2289 check_specialization_scope. */
2290 return error_mark_node;
2292 case tsk_invalid_expl_inst:
2293 error ("template parameter list used in explicit instantiation");
2299 error ("definition provided for explicit instantiation");
2301 explicit_instantiation = 1;
2304 case tsk_excessive_parms:
2305 case tsk_insufficient_parms:
2306 if (tsk == tsk_excessive_parms)
2307 error ("too many template parameter lists in declaration of %qD",
2309 else if (template_header_count)
2310 error("too few template parameter lists in declaration of %qD", decl);
2312 error("explicit specialization of %qD must be introduced by "
2313 "%<template <>%>", decl);
2317 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2319 member_specialization = 1;
2325 if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2327 /* This case handles bogus declarations like template <>
2328 template <class T> void f<int>(); */
2330 if (uses_template_parms (declarator))
2331 error ("function template partial specialization %qD "
2332 "is not allowed", declarator);
2334 error ("template-id %qD in declaration of primary template",
2339 if (ctype && CLASSTYPE_TEMPLATE_INSTANTIATION (ctype))
2340 /* This is a specialization of a member template, without
2341 specialization the containing class. Something like:
2343 template <class T> struct S {
2344 template <class U> void f (U);
2346 template <> template <class U> void S<int>::f(U) {}
2348 That's a specialization -- but of the entire template. */
2356 if (specialization || member_specialization)
2358 tree t = TYPE_ARG_TYPES (TREE_TYPE (decl));
2359 for (; t; t = TREE_CHAIN (t))
2360 if (TREE_PURPOSE (t))
2362 permerror (input_location,
2363 "default argument specified in explicit specialization");
2368 if (specialization || member_specialization || explicit_instantiation)
2370 tree tmpl = NULL_TREE;
2371 tree targs = NULL_TREE;
2373 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2374 if (TREE_CODE (declarator) != TEMPLATE_ID_EXPR)
2378 gcc_assert (TREE_CODE (declarator) == IDENTIFIER_NODE);
2383 /* If there is no class context, the explicit instantiation
2384 must be at namespace scope. */
2385 gcc_assert (DECL_NAMESPACE_SCOPE_P (decl));
2387 /* Find the namespace binding, using the declaration
2389 fns = lookup_qualified_name (CP_DECL_CONTEXT (decl), dname,
2391 if (fns == error_mark_node || !is_overloaded_fn (fns))
2393 error ("%qD is not a template function", dname);
2394 fns = error_mark_node;
2398 tree fn = OVL_CURRENT (fns);
2399 if (!is_associated_namespace (CP_DECL_CONTEXT (decl),
2400 CP_DECL_CONTEXT (fn)))
2401 error ("%qD is not declared in %qD",
2402 decl, current_namespace);
2406 declarator = lookup_template_function (fns, NULL_TREE);
2409 if (declarator == error_mark_node)
2410 return error_mark_node;
2412 if (ctype != NULL_TREE && TYPE_BEING_DEFINED (ctype))
2414 if (!explicit_instantiation)
2415 /* A specialization in class scope. This is invalid,
2416 but the error will already have been flagged by
2417 check_specialization_scope. */
2418 return error_mark_node;
2421 /* It's not valid to write an explicit instantiation in
2424 class C { template void f(); }
2426 This case is caught by the parser. However, on
2429 template class C { void f(); };
2431 (which is invalid) we can get here. The error will be
2438 else if (ctype != NULL_TREE
2439 && (TREE_CODE (TREE_OPERAND (declarator, 0)) ==
2442 /* Find the list of functions in ctype that have the same
2443 name as the declared function. */
2444 tree name = TREE_OPERAND (declarator, 0);
2445 tree fns = NULL_TREE;
2448 if (constructor_name_p (name, ctype))
2450 int is_constructor = DECL_CONSTRUCTOR_P (decl);
2452 if (is_constructor ? !TYPE_HAS_USER_CONSTRUCTOR (ctype)
2453 : !CLASSTYPE_DESTRUCTORS (ctype))
2455 /* From [temp.expl.spec]:
2457 If such an explicit specialization for the member
2458 of a class template names an implicitly-declared
2459 special member function (clause _special_), the
2460 program is ill-formed.
2462 Similar language is found in [temp.explicit]. */
2463 error ("specialization of implicitly-declared special member function");
2464 return error_mark_node;
2467 name = is_constructor ? ctor_identifier : dtor_identifier;
2470 if (!DECL_CONV_FN_P (decl))
2472 idx = lookup_fnfields_1 (ctype, name);
2474 fns = VEC_index (tree, CLASSTYPE_METHOD_VEC (ctype), idx);
2478 VEC(tree,gc) *methods;
2481 /* For a type-conversion operator, we cannot do a
2482 name-based lookup. We might be looking for `operator
2483 int' which will be a specialization of `operator T'.
2484 So, we find *all* the conversion operators, and then
2485 select from them. */
2488 methods = CLASSTYPE_METHOD_VEC (ctype);
2490 for (idx = CLASSTYPE_FIRST_CONVERSION_SLOT;
2491 VEC_iterate (tree, methods, idx, ovl);
2494 if (!DECL_CONV_FN_P (OVL_CURRENT (ovl)))
2495 /* There are no more conversion functions. */
2498 /* Glue all these conversion functions together
2499 with those we already have. */
2500 for (; ovl; ovl = OVL_NEXT (ovl))
2501 fns = ovl_cons (OVL_CURRENT (ovl), fns);
2505 if (fns == NULL_TREE)
2507 error ("no member function %qD declared in %qT", name, ctype);
2508 return error_mark_node;
2511 TREE_OPERAND (declarator, 0) = fns;
2514 /* Figure out what exactly is being specialized at this point.
2515 Note that for an explicit instantiation, even one for a
2516 member function, we cannot tell apriori whether the
2517 instantiation is for a member template, or just a member
2518 function of a template class. Even if a member template is
2519 being instantiated, the member template arguments may be
2520 elided if they can be deduced from the rest of the
2522 tmpl = determine_specialization (declarator, decl,
2524 member_specialization,
2528 if (!tmpl || tmpl == error_mark_node)
2529 /* We couldn't figure out what this declaration was
2531 return error_mark_node;
2534 tree gen_tmpl = most_general_template (tmpl);
2536 if (explicit_instantiation)
2538 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2539 is done by do_decl_instantiation later. */
2541 int arg_depth = TMPL_ARGS_DEPTH (targs);
2542 int parm_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
2544 if (arg_depth > parm_depth)
2546 /* If TMPL is not the most general template (for
2547 example, if TMPL is a friend template that is
2548 injected into namespace scope), then there will
2549 be too many levels of TARGS. Remove some of them
2554 new_targs = make_tree_vec (parm_depth);
2555 for (i = arg_depth - parm_depth; i < arg_depth; ++i)
2556 TREE_VEC_ELT (new_targs, i - (arg_depth - parm_depth))
2557 = TREE_VEC_ELT (targs, i);
2561 return instantiate_template (tmpl, targs, tf_error);
2564 /* If we thought that the DECL was a member function, but it
2565 turns out to be specializing a static member function,
2566 make DECL a static member function as well. */
2567 if (DECL_STATIC_FUNCTION_P (tmpl)
2568 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2569 revert_static_member_fn (decl);
2571 /* If this is a specialization of a member template of a
2572 template class, we want to return the TEMPLATE_DECL, not
2573 the specialization of it. */
2574 if (tsk == tsk_template)
2576 tree result = DECL_TEMPLATE_RESULT (tmpl);
2577 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
2578 DECL_INITIAL (result) = NULL_TREE;
2582 DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl);
2583 DECL_SOURCE_LOCATION (result)
2584 = DECL_SOURCE_LOCATION (decl);
2585 /* We want to use the argument list specified in the
2586 definition, not in the original declaration. */
2587 DECL_ARGUMENTS (result) = DECL_ARGUMENTS (decl);
2588 for (parm = DECL_ARGUMENTS (result); parm;
2589 parm = DECL_CHAIN (parm))
2590 DECL_CONTEXT (parm) = result;
2592 return register_specialization (tmpl, gen_tmpl, targs,
2596 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2597 DECL_TEMPLATE_INFO (decl) = build_template_info (tmpl, targs);
2599 /* Inherit default function arguments from the template
2600 DECL is specializing. */
2601 copy_default_args_to_explicit_spec (decl);
2603 /* This specialization has the same protection as the
2604 template it specializes. */
2605 TREE_PRIVATE (decl) = TREE_PRIVATE (gen_tmpl);
2606 TREE_PROTECTED (decl) = TREE_PROTECTED (gen_tmpl);
2608 /* 7.1.1-1 [dcl.stc]
2610 A storage-class-specifier shall not be specified in an
2611 explicit specialization...
2613 The parser rejects these, so unless action is taken here,
2614 explicit function specializations will always appear with
2617 The action recommended by the C++ CWG in response to C++
2618 defect report 605 is to make the storage class and linkage
2619 of the explicit specialization match the templated function:
2621 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2623 if (tsk == tsk_expl_spec && DECL_FUNCTION_TEMPLATE_P (gen_tmpl))
2625 tree tmpl_func = DECL_TEMPLATE_RESULT (gen_tmpl);
2626 gcc_assert (TREE_CODE (tmpl_func) == FUNCTION_DECL);
2628 /* This specialization has the same linkage and visibility as
2629 the function template it specializes. */
2630 TREE_PUBLIC (decl) = TREE_PUBLIC (tmpl_func);
2631 if (! TREE_PUBLIC (decl))
2633 DECL_INTERFACE_KNOWN (decl) = 1;
2634 DECL_NOT_REALLY_EXTERN (decl) = 1;
2636 DECL_THIS_STATIC (decl) = DECL_THIS_STATIC (tmpl_func);
2637 if (DECL_VISIBILITY_SPECIFIED (tmpl_func))
2639 DECL_VISIBILITY_SPECIFIED (decl) = 1;
2640 DECL_VISIBILITY (decl) = DECL_VISIBILITY (tmpl_func);
2644 /* If DECL is a friend declaration, declared using an
2645 unqualified name, the namespace associated with DECL may
2646 have been set incorrectly. For example, in:
2648 template <typename T> void f(T);
2650 struct S { friend void f<int>(int); }
2653 we will have set the DECL_CONTEXT for the friend
2654 declaration to N, rather than to the global namespace. */
2655 if (DECL_NAMESPACE_SCOPE_P (decl))
2656 DECL_CONTEXT (decl) = DECL_CONTEXT (tmpl);
2658 if (is_friend && !have_def)
2659 /* This is not really a declaration of a specialization.
2660 It's just the name of an instantiation. But, it's not
2661 a request for an instantiation, either. */
2662 SET_DECL_IMPLICIT_INSTANTIATION (decl);
2663 else if (DECL_CONSTRUCTOR_P (decl) || DECL_DESTRUCTOR_P (decl))
2664 /* This is indeed a specialization. In case of constructors
2665 and destructors, we need in-charge and not-in-charge
2666 versions in V3 ABI. */
2667 clone_function_decl (decl, /*update_method_vec_p=*/0);
2669 /* Register this specialization so that we can find it
2671 decl = register_specialization (decl, gen_tmpl, targs, is_friend, 0);
2678 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2679 parameters. These are represented in the same format used for
2680 DECL_TEMPLATE_PARMS. */
2683 comp_template_parms (const_tree parms1, const_tree parms2)
2688 if (parms1 == parms2)
2691 for (p1 = parms1, p2 = parms2;
2692 p1 != NULL_TREE && p2 != NULL_TREE;
2693 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2))
2695 tree t1 = TREE_VALUE (p1);
2696 tree t2 = TREE_VALUE (p2);
2699 gcc_assert (TREE_CODE (t1) == TREE_VEC);
2700 gcc_assert (TREE_CODE (t2) == TREE_VEC);
2702 if (TREE_VEC_LENGTH (t1) != TREE_VEC_LENGTH (t2))
2705 for (i = 0; i < TREE_VEC_LENGTH (t2); ++i)
2707 tree parm1 = TREE_VALUE (TREE_VEC_ELT (t1, i));
2708 tree parm2 = TREE_VALUE (TREE_VEC_ELT (t2, i));
2710 /* If either of the template parameters are invalid, assume
2711 they match for the sake of error recovery. */
2712 if (parm1 == error_mark_node || parm2 == error_mark_node)
2715 if (TREE_CODE (parm1) != TREE_CODE (parm2))
2718 if (TREE_CODE (parm1) == TEMPLATE_TYPE_PARM
2719 && (TEMPLATE_TYPE_PARAMETER_PACK (parm1)
2720 == TEMPLATE_TYPE_PARAMETER_PACK (parm2)))
2722 else if (!same_type_p (TREE_TYPE (parm1), TREE_TYPE (parm2)))
2727 if ((p1 != NULL_TREE) != (p2 != NULL_TREE))
2728 /* One set of parameters has more parameters lists than the
2735 /* Determine whether PARM is a parameter pack. */
2738 template_parameter_pack_p (const_tree parm)
2740 /* Determine if we have a non-type template parameter pack. */
2741 if (TREE_CODE (parm) == PARM_DECL)
2742 return (DECL_TEMPLATE_PARM_P (parm)
2743 && TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)));
2745 /* If this is a list of template parameters, we could get a
2746 TYPE_DECL or a TEMPLATE_DECL. */
2747 if (TREE_CODE (parm) == TYPE_DECL || TREE_CODE (parm) == TEMPLATE_DECL)
2748 parm = TREE_TYPE (parm);
2750 return ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
2751 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM)
2752 && TEMPLATE_TYPE_PARAMETER_PACK (parm));
2755 /* Determine if T is a function parameter pack. */
2758 function_parameter_pack_p (const_tree t)
2760 if (t && TREE_CODE (t) == PARM_DECL)
2761 return FUNCTION_PARAMETER_PACK_P (t);
2765 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2766 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2769 get_function_template_decl (const_tree primary_func_tmpl_inst)
2771 if (! primary_func_tmpl_inst
2772 || TREE_CODE (primary_func_tmpl_inst) != FUNCTION_DECL
2773 || ! primary_template_instantiation_p (primary_func_tmpl_inst))
2776 return DECL_TEMPLATE_RESULT (DECL_TI_TEMPLATE (primary_func_tmpl_inst));
2779 /* Return true iff the function parameter PARAM_DECL was expanded
2780 from the function parameter pack PACK. */
2783 function_parameter_expanded_from_pack_p (tree param_decl, tree pack)
2785 if (DECL_ARTIFICIAL (param_decl)
2786 || !function_parameter_pack_p (pack))
2789 /* The parameter pack and its pack arguments have the same
2791 return DECL_PARM_INDEX (pack) == DECL_PARM_INDEX (param_decl);
2794 /* Determine whether ARGS describes a variadic template args list,
2795 i.e., one that is terminated by a template argument pack. */
2798 template_args_variadic_p (tree args)
2803 if (args == NULL_TREE)
2806 args = INNERMOST_TEMPLATE_ARGS (args);
2807 nargs = TREE_VEC_LENGTH (args);
2812 last_parm = TREE_VEC_ELT (args, nargs - 1);
2814 return ARGUMENT_PACK_P (last_parm);
2817 /* Generate a new name for the parameter pack name NAME (an
2818 IDENTIFIER_NODE) that incorporates its */
2821 make_ith_pack_parameter_name (tree name, int i)
2823 /* Munge the name to include the parameter index. */
2824 #define NUMBUF_LEN 128
2825 char numbuf[NUMBUF_LEN];
2829 snprintf (numbuf, NUMBUF_LEN, "%i", i);
2830 newname_len = IDENTIFIER_LENGTH (name)
2831 + strlen (numbuf) + 2;
2832 newname = (char*)alloca (newname_len);
2833 snprintf (newname, newname_len,
2834 "%s#%i", IDENTIFIER_POINTER (name), i);
2835 return get_identifier (newname);
2838 /* Return true if T is a primary function
2839 or class template instantiation. */
2842 primary_template_instantiation_p (const_tree t)
2847 if (TREE_CODE (t) == FUNCTION_DECL)
2848 return DECL_LANG_SPECIFIC (t)
2849 && DECL_TEMPLATE_INSTANTIATION (t)
2850 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (t));
2851 else if (CLASS_TYPE_P (t))
2852 return CLASSTYPE_TEMPLATE_INSTANTIATION (t)
2853 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (t));
2857 /* Return true if PARM is a template template parameter. */
2860 template_template_parameter_p (const_tree parm)
2862 return DECL_TEMPLATE_TEMPLATE_PARM_P (parm);
2865 /* Return the template parameters of T if T is a
2866 primary template instantiation, NULL otherwise. */
2869 get_primary_template_innermost_parameters (const_tree t)
2871 tree parms = NULL, template_info = NULL;
2873 if ((template_info = get_template_info (t))
2874 && primary_template_instantiation_p (t))
2875 parms = INNERMOST_TEMPLATE_PARMS
2876 (DECL_TEMPLATE_PARMS (TI_TEMPLATE (template_info)));
2881 /* Return the template parameters of the LEVELth level from the full list
2882 of template parameters PARMS. */
2885 get_template_parms_at_level (tree parms, int level)
2889 || TREE_CODE (parms) != TREE_LIST
2890 || level > TMPL_PARMS_DEPTH (parms))
2893 for (p = parms; p; p = TREE_CHAIN (p))
2894 if (TMPL_PARMS_DEPTH (p) == level)
2900 /* Returns the template arguments of T if T is a template instantiation,
2904 get_template_innermost_arguments (const_tree t)
2906 tree args = NULL, template_info = NULL;
2908 if ((template_info = get_template_info (t))
2909 && TI_ARGS (template_info))
2910 args = INNERMOST_TEMPLATE_ARGS (TI_ARGS (template_info));
2915 /* Return the argument pack elements of T if T is a template argument pack,
2919 get_template_argument_pack_elems (const_tree t)
2921 if (TREE_CODE (t) != TYPE_ARGUMENT_PACK
2922 && TREE_CODE (t) != NONTYPE_ARGUMENT_PACK)
2925 return ARGUMENT_PACK_ARGS (t);
2928 /* Structure used to track the progress of find_parameter_packs_r. */
2929 struct find_parameter_pack_data
2931 /* TREE_LIST that will contain all of the parameter packs found by
2933 tree* parameter_packs;
2935 /* Set of AST nodes that have been visited by the traversal. */
2936 struct pointer_set_t *visited;
2939 /* Identifies all of the argument packs that occur in a template
2940 argument and appends them to the TREE_LIST inside DATA, which is a
2941 find_parameter_pack_data structure. This is a subroutine of
2942 make_pack_expansion and uses_parameter_packs. */
2944 find_parameter_packs_r (tree *tp, int *walk_subtrees, void* data)
2947 struct find_parameter_pack_data* ppd =
2948 (struct find_parameter_pack_data*)data;
2949 bool parameter_pack_p = false;
2951 /* Identify whether this is a parameter pack or not. */
2952 switch (TREE_CODE (t))
2954 case TEMPLATE_PARM_INDEX:
2955 if (TEMPLATE_PARM_PARAMETER_PACK (t))
2956 parameter_pack_p = true;
2959 case TEMPLATE_TYPE_PARM:
2960 case TEMPLATE_TEMPLATE_PARM:
2961 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
2962 parameter_pack_p = true;
2966 if (FUNCTION_PARAMETER_PACK_P (t))
2968 /* We don't want to walk into the type of a PARM_DECL,
2969 because we don't want to see the type parameter pack. */
2971 parameter_pack_p = true;
2976 /* Not a parameter pack. */
2980 if (parameter_pack_p)
2982 /* Add this parameter pack to the list. */
2983 *ppd->parameter_packs = tree_cons (NULL_TREE, t, *ppd->parameter_packs);
2987 cp_walk_tree (&TYPE_CONTEXT (t),
2988 &find_parameter_packs_r, ppd, ppd->visited);
2990 /* This switch statement will return immediately if we don't find a
2992 switch (TREE_CODE (t))
2994 case TEMPLATE_PARM_INDEX:
2997 case BOUND_TEMPLATE_TEMPLATE_PARM:
2998 /* Check the template itself. */
2999 cp_walk_tree (&TREE_TYPE (TYPE_TI_TEMPLATE (t)),
3000 &find_parameter_packs_r, ppd, ppd->visited);
3001 /* Check the template arguments. */
3002 cp_walk_tree (&TYPE_TI_ARGS (t), &find_parameter_packs_r, ppd,
3007 case TEMPLATE_TYPE_PARM:
3008 case TEMPLATE_TEMPLATE_PARM:
3015 if (TYPE_PTRMEMFUNC_P (t))
3021 if (TYPE_TEMPLATE_INFO (t))
3022 cp_walk_tree (&TI_ARGS (TYPE_TEMPLATE_INFO (t)),
3023 &find_parameter_packs_r, ppd, ppd->visited);
3030 cp_walk_tree (&TREE_TYPE (t),
3031 &find_parameter_packs_r, ppd, ppd->visited);
3035 cp_walk_tree (&TYPENAME_TYPE_FULLNAME (t), &find_parameter_packs_r,
3040 case TYPE_PACK_EXPANSION:
3041 case EXPR_PACK_EXPANSION:
3046 cp_walk_tree (&TYPE_MAX_VALUE (t), &find_parameter_packs_r,
3051 case IDENTIFIER_NODE:
3052 cp_walk_tree (&TREE_TYPE (t), &find_parameter_packs_r, ppd,
3064 /* Determines if the expression or type T uses any parameter packs. */
3066 uses_parameter_packs (tree t)
3068 tree parameter_packs = NULL_TREE;
3069 struct find_parameter_pack_data ppd;
3070 ppd.parameter_packs = ¶meter_packs;
3071 ppd.visited = pointer_set_create ();
3072 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
3073 pointer_set_destroy (ppd.visited);
3074 return parameter_packs != NULL_TREE;
3077 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3078 representation a base-class initializer into a parameter pack
3079 expansion. If all goes well, the resulting node will be an
3080 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3083 make_pack_expansion (tree arg)
3086 tree parameter_packs = NULL_TREE;
3087 bool for_types = false;
3088 struct find_parameter_pack_data ppd;
3090 if (!arg || arg == error_mark_node)
3093 if (TREE_CODE (arg) == TREE_LIST)
3095 /* The only time we will see a TREE_LIST here is for a base
3096 class initializer. In this case, the TREE_PURPOSE will be a
3097 _TYPE node (representing the base class expansion we're
3098 initializing) and the TREE_VALUE will be a TREE_LIST
3099 containing the initialization arguments.
3101 The resulting expansion looks somewhat different from most
3102 expansions. Rather than returning just one _EXPANSION, we
3103 return a TREE_LIST whose TREE_PURPOSE is a
3104 TYPE_PACK_EXPANSION containing the bases that will be
3105 initialized. The TREE_VALUE will be identical to the
3106 original TREE_VALUE, which is a list of arguments that will
3107 be passed to each base. We do not introduce any new pack
3108 expansion nodes into the TREE_VALUE (although it is possible
3109 that some already exist), because the TREE_PURPOSE and
3110 TREE_VALUE all need to be expanded together with the same
3111 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3112 resulting TREE_PURPOSE will mention the parameter packs in
3113 both the bases and the arguments to the bases. */
3116 tree parameter_packs = NULL_TREE;
3118 /* Determine which parameter packs will be used by the base
3120 ppd.visited = pointer_set_create ();
3121 ppd.parameter_packs = ¶meter_packs;
3122 cp_walk_tree (&TREE_PURPOSE (arg), &find_parameter_packs_r,
3125 if (parameter_packs == NULL_TREE)
3127 error ("base initializer expansion %<%T%> contains no parameter packs", arg);
3128 pointer_set_destroy (ppd.visited);
3129 return error_mark_node;
3132 if (TREE_VALUE (arg) != void_type_node)
3134 /* Collect the sets of parameter packs used in each of the
3135 initialization arguments. */
3136 for (value = TREE_VALUE (arg); value; value = TREE_CHAIN (value))
3138 /* Determine which parameter packs will be expanded in this
3140 cp_walk_tree (&TREE_VALUE (value), &find_parameter_packs_r,
3145 pointer_set_destroy (ppd.visited);
3147 /* Create the pack expansion type for the base type. */
3148 purpose = cxx_make_type (TYPE_PACK_EXPANSION);
3149 SET_PACK_EXPANSION_PATTERN (purpose, TREE_PURPOSE (arg));
3150 PACK_EXPANSION_PARAMETER_PACKS (purpose) = parameter_packs;
3152 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3153 they will rarely be compared to anything. */
3154 SET_TYPE_STRUCTURAL_EQUALITY (purpose);
3156 return tree_cons (purpose, TREE_VALUE (arg), NULL_TREE);
3159 if (TYPE_P (arg) || TREE_CODE (arg) == TEMPLATE_DECL)
3162 /* Build the PACK_EXPANSION_* node. */
3164 ? cxx_make_type (TYPE_PACK_EXPANSION)
3165 : make_node (EXPR_PACK_EXPANSION);
3166 SET_PACK_EXPANSION_PATTERN (result, arg);
3167 if (TREE_CODE (result) == EXPR_PACK_EXPANSION)
3169 /* Propagate type and const-expression information. */
3170 TREE_TYPE (result) = TREE_TYPE (arg);
3171 TREE_CONSTANT (result) = TREE_CONSTANT (arg);
3174 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3175 they will rarely be compared to anything. */
3176 SET_TYPE_STRUCTURAL_EQUALITY (result);
3178 /* Determine which parameter packs will be expanded. */
3179 ppd.parameter_packs = ¶meter_packs;
3180 ppd.visited = pointer_set_create ();
3181 cp_walk_tree (&arg, &find_parameter_packs_r, &ppd, ppd.visited);
3182 pointer_set_destroy (ppd.visited);
3184 /* Make sure we found some parameter packs. */
3185 if (parameter_packs == NULL_TREE)
3188 error ("expansion pattern %<%T%> contains no argument packs", arg);
3190 error ("expansion pattern %<%E%> contains no argument packs", arg);
3191 return error_mark_node;
3193 PACK_EXPANSION_PARAMETER_PACKS (result) = parameter_packs;
3198 /* Checks T for any "bare" parameter packs, which have not yet been
3199 expanded, and issues an error if any are found. This operation can
3200 only be done on full expressions or types (e.g., an expression
3201 statement, "if" condition, etc.), because we could have expressions like:
3203 foo(f(g(h(args)))...)
3205 where "args" is a parameter pack. check_for_bare_parameter_packs
3206 should not be called for the subexpressions args, h(args),
3207 g(h(args)), or f(g(h(args))), because we would produce erroneous
3210 Returns TRUE and emits an error if there were bare parameter packs,
3211 returns FALSE otherwise. */
3213 check_for_bare_parameter_packs (tree t)
3215 tree parameter_packs = NULL_TREE;
3216 struct find_parameter_pack_data ppd;
3218 if (!processing_template_decl || !t || t == error_mark_node)
3221 if (TREE_CODE (t) == TYPE_DECL)
3224 ppd.parameter_packs = ¶meter_packs;
3225 ppd.visited = pointer_set_create ();
3226 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
3227 pointer_set_destroy (ppd.visited);
3229 if (parameter_packs)
3231 error ("parameter packs not expanded with %<...%>:");
3232 while (parameter_packs)
3234 tree pack = TREE_VALUE (parameter_packs);
3235 tree name = NULL_TREE;
3237 if (TREE_CODE (pack) == TEMPLATE_TYPE_PARM
3238 || TREE_CODE (pack) == TEMPLATE_TEMPLATE_PARM)
3239 name = TYPE_NAME (pack);
3240 else if (TREE_CODE (pack) == TEMPLATE_PARM_INDEX)
3241 name = DECL_NAME (TEMPLATE_PARM_DECL (pack));
3243 name = DECL_NAME (pack);
3246 inform (input_location, " %qD", name);
3248 inform (input_location, " <anonymous>");
3250 parameter_packs = TREE_CHAIN (parameter_packs);
3259 /* Expand any parameter packs that occur in the template arguments in
3262 expand_template_argument_pack (tree args)
3264 tree result_args = NULL_TREE;
3265 int in_arg, out_arg = 0, nargs = args ? TREE_VEC_LENGTH (args) : 0;
3266 int num_result_args = -1;
3267 int non_default_args_count = -1;
3269 /* First, determine if we need to expand anything, and the number of
3270 slots we'll need. */
3271 for (in_arg = 0; in_arg < nargs; ++in_arg)
3273 tree arg = TREE_VEC_ELT (args, in_arg);
3274 if (arg == NULL_TREE)
3276 if (ARGUMENT_PACK_P (arg))
3278 int num_packed = TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg));
3279 if (num_result_args < 0)
3280 num_result_args = in_arg + num_packed;
3282 num_result_args += num_packed;
3286 if (num_result_args >= 0)
3291 /* If no expansion is necessary, we're done. */
3292 if (num_result_args < 0)
3295 /* Expand arguments. */
3296 result_args = make_tree_vec (num_result_args);
3297 if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (args))
3298 non_default_args_count =
3299 GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (args);
3300 for (in_arg = 0; in_arg < nargs; ++in_arg)
3302 tree arg = TREE_VEC_ELT (args, in_arg);
3303 if (ARGUMENT_PACK_P (arg))
3305 tree packed = ARGUMENT_PACK_ARGS (arg);
3306 int i, num_packed = TREE_VEC_LENGTH (packed);
3307 for (i = 0; i < num_packed; ++i, ++out_arg)
3308 TREE_VEC_ELT (result_args, out_arg) = TREE_VEC_ELT(packed, i);
3309 if (non_default_args_count > 0)
3310 non_default_args_count += num_packed;
3314 TREE_VEC_ELT (result_args, out_arg) = arg;
3318 if (non_default_args_count >= 0)
3319 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (result_args, non_default_args_count);
3323 /* Checks if DECL shadows a template parameter.
3325 [temp.local]: A template-parameter shall not be redeclared within its
3326 scope (including nested scopes).
3328 Emits an error and returns TRUE if the DECL shadows a parameter,
3329 returns FALSE otherwise. */
3332 check_template_shadow (tree decl)
3336 /* If we're not in a template, we can't possibly shadow a template
3338 if (!current_template_parms)
3341 /* Figure out what we're shadowing. */
3342 if (TREE_CODE (decl) == OVERLOAD)
3343 decl = OVL_CURRENT (decl);
3344 olddecl = innermost_non_namespace_value (DECL_NAME (decl));
3346 /* If there's no previous binding for this name, we're not shadowing
3347 anything, let alone a template parameter. */
3351 /* If we're not shadowing a template parameter, we're done. Note
3352 that OLDDECL might be an OVERLOAD (or perhaps even an
3353 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3355 if (!DECL_P (olddecl) || !DECL_TEMPLATE_PARM_P (olddecl))
3358 /* We check for decl != olddecl to avoid bogus errors for using a
3359 name inside a class. We check TPFI to avoid duplicate errors for
3360 inline member templates. */
3362 || TEMPLATE_PARMS_FOR_INLINE (current_template_parms))
3365 error ("declaration of %q+#D", decl);
3366 error (" shadows template parm %q+#D", olddecl);
3370 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3371 ORIG_LEVEL, DECL, and TYPE. NUM_SIBLINGS is the total number of
3372 template parameters. */
3375 build_template_parm_index (int index,
3382 tree t = make_node (TEMPLATE_PARM_INDEX);
3383 TEMPLATE_PARM_IDX (t) = index;
3384 TEMPLATE_PARM_LEVEL (t) = level;
3385 TEMPLATE_PARM_ORIG_LEVEL (t) = orig_level;
3386 TEMPLATE_PARM_NUM_SIBLINGS (t) = num_siblings;
3387 TEMPLATE_PARM_DECL (t) = decl;
3388 TREE_TYPE (t) = type;
3389 TREE_CONSTANT (t) = TREE_CONSTANT (decl);
3390 TREE_READONLY (t) = TREE_READONLY (decl);
3395 /* Find the canonical type parameter for the given template type
3396 parameter. Returns the canonical type parameter, which may be TYPE
3397 if no such parameter existed. */
3400 canonical_type_parameter (tree type)
3403 int idx = TEMPLATE_TYPE_IDX (type);
3404 if (!canonical_template_parms)
3405 canonical_template_parms = VEC_alloc (tree, gc, idx+1);
3407 while (VEC_length (tree, canonical_template_parms) <= (unsigned)idx)
3408 VEC_safe_push (tree, gc, canonical_template_parms, NULL_TREE);
3410 list = VEC_index (tree, canonical_template_parms, idx);
3411 while (list && !comptypes (type, TREE_VALUE (list), COMPARE_STRUCTURAL))
3412 list = TREE_CHAIN (list);
3415 return TREE_VALUE (list);
3418 VEC_replace(tree, canonical_template_parms, idx,
3419 tree_cons (NULL_TREE, type,
3420 VEC_index (tree, canonical_template_parms, idx)));
3425 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3426 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3427 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3428 new one is created. */
3431 reduce_template_parm_level (tree index, tree type, int levels, tree args,
3432 tsubst_flags_t complain)
3434 if (TEMPLATE_PARM_DESCENDANTS (index) == NULL_TREE
3435 || (TEMPLATE_PARM_LEVEL (TEMPLATE_PARM_DESCENDANTS (index))
3436 != TEMPLATE_PARM_LEVEL (index) - levels)
3437 || !same_type_p (type, TREE_TYPE (TEMPLATE_PARM_DESCENDANTS (index))))
3439 tree orig_decl = TEMPLATE_PARM_DECL (index);
3442 decl = build_decl (DECL_SOURCE_LOCATION (orig_decl),
3443 TREE_CODE (orig_decl), DECL_NAME (orig_decl), type);
3444 TREE_CONSTANT (decl) = TREE_CONSTANT (orig_decl);
3445 TREE_READONLY (decl) = TREE_READONLY (orig_decl);
3446 DECL_ARTIFICIAL (decl) = 1;
3447 SET_DECL_TEMPLATE_PARM_P (decl);
3449 t = build_template_parm_index (TEMPLATE_PARM_IDX (index),
3450 TEMPLATE_PARM_LEVEL (index) - levels,
3451 TEMPLATE_PARM_ORIG_LEVEL (index),
3452 TEMPLATE_PARM_NUM_SIBLINGS (index),
3454 TEMPLATE_PARM_DESCENDANTS (index) = t;
3455 TEMPLATE_PARM_PARAMETER_PACK (t)
3456 = TEMPLATE_PARM_PARAMETER_PACK (index);
3458 /* Template template parameters need this. */
3459 if (TREE_CODE (decl) == TEMPLATE_DECL)
3460 DECL_TEMPLATE_PARMS (decl) = tsubst_template_parms
3461 (DECL_TEMPLATE_PARMS (TEMPLATE_PARM_DECL (index)),
3465 return TEMPLATE_PARM_DESCENDANTS (index);
3468 /* Process information from new template parameter PARM and append it
3469 to the LIST being built. This new parameter is a non-type
3470 parameter iff IS_NON_TYPE is true. This new parameter is a
3471 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3472 is in PARM_LOC. NUM_TEMPLATE_PARMS is the size of the template
3473 parameter list PARM belongs to. This is used used to create a
3474 proper canonical type for the type of PARM that is to be created,
3475 iff PARM is a type. If the size is not known, this parameter shall
3479 process_template_parm (tree list, location_t parm_loc, tree parm,
3480 bool is_non_type, bool is_parameter_pack,
3481 unsigned num_template_parms)
3488 gcc_assert (TREE_CODE (parm) == TREE_LIST);
3489 defval = TREE_PURPOSE (parm);
3493 tree p = tree_last (list);
3495 if (p && TREE_VALUE (p) != error_mark_node)
3498 if (TREE_CODE (p) == TYPE_DECL || TREE_CODE (p) == TEMPLATE_DECL)
3499 idx = TEMPLATE_TYPE_IDX (TREE_TYPE (p));
3501 idx = TEMPLATE_PARM_IDX (DECL_INITIAL (p));
3511 parm = TREE_VALUE (parm);
3513 SET_DECL_TEMPLATE_PARM_P (parm);
3515 if (TREE_TYPE (parm) == error_mark_node)
3517 err_parm_list = build_tree_list (defval, parm);
3518 TREE_VALUE (err_parm_list) = error_mark_node;
3519 return chainon (list, err_parm_list);
3525 The top-level cv-qualifiers on the template-parameter are
3526 ignored when determining its type. */
3527 TREE_TYPE (parm) = TYPE_MAIN_VARIANT (TREE_TYPE (parm));
3528 if (invalid_nontype_parm_type_p (TREE_TYPE (parm), 1))
3530 err_parm_list = build_tree_list (defval, parm);
3531 TREE_VALUE (err_parm_list) = error_mark_node;
3532 return chainon (list, err_parm_list);
3535 if (uses_parameter_packs (TREE_TYPE (parm)) && !is_parameter_pack)
3537 /* This template parameter is not a parameter pack, but it
3538 should be. Complain about "bare" parameter packs. */
3539 check_for_bare_parameter_packs (TREE_TYPE (parm));
3541 /* Recover by calling this a parameter pack. */
3542 is_parameter_pack = true;
3546 /* A template parameter is not modifiable. */
3547 TREE_CONSTANT (parm) = 1;
3548 TREE_READONLY (parm) = 1;
3549 decl = build_decl (parm_loc,
3550 CONST_DECL, DECL_NAME (parm), TREE_TYPE (parm));
3551 TREE_CONSTANT (decl) = 1;
3552 TREE_READONLY (decl) = 1;
3553 DECL_INITIAL (parm) = DECL_INITIAL (decl)
3554 = build_template_parm_index (idx, processing_template_decl,
3555 processing_template_decl,
3557 decl, TREE_TYPE (parm));
3559 TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))
3560 = is_parameter_pack;
3565 parm = TREE_VALUE (TREE_VALUE (parm));
3567 if (parm && TREE_CODE (parm) == TEMPLATE_DECL)
3569 t = cxx_make_type (TEMPLATE_TEMPLATE_PARM);
3570 /* This is for distinguishing between real templates and template
3571 template parameters */
3572 TREE_TYPE (parm) = t;
3573 TREE_TYPE (DECL_TEMPLATE_RESULT (parm)) = t;
3578 t = cxx_make_type (TEMPLATE_TYPE_PARM);
3579 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3580 decl = build_decl (parm_loc,
3581 TYPE_DECL, parm, t);
3584 TYPE_NAME (t) = decl;
3585 TYPE_STUB_DECL (t) = decl;
3587 TEMPLATE_TYPE_PARM_INDEX (t)
3588 = build_template_parm_index (idx, processing_template_decl,
3589 processing_template_decl,
3591 decl, TREE_TYPE (parm));
3592 TEMPLATE_TYPE_PARAMETER_PACK (t) = is_parameter_pack;
3593 TYPE_CANONICAL (t) = canonical_type_parameter (t);
3595 DECL_ARTIFICIAL (decl) = 1;
3596 SET_DECL_TEMPLATE_PARM_P (decl);
3598 parm = build_tree_list (defval, parm);
3599 return chainon (list, parm);
3602 /* The end of a template parameter list has been reached. Process the
3603 tree list into a parameter vector, converting each parameter into a more
3604 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3608 end_template_parm_list (tree parms)
3612 tree saved_parmlist = make_tree_vec (list_length (parms));
3614 current_template_parms
3615 = tree_cons (size_int (processing_template_decl),
3616 saved_parmlist, current_template_parms);
3618 for (parm = parms, nparms = 0; parm; parm = next, nparms++)
3620 next = TREE_CHAIN (parm);
3621 TREE_VEC_ELT (saved_parmlist, nparms) = parm;
3622 TREE_CHAIN (parm) = NULL_TREE;
3625 --processing_template_parmlist;
3627 return saved_parmlist;
3630 /* Create a new type almost identical to TYPE but which has the
3631 following differences:
3633 1/ T has a new TEMPLATE_PARM_INDEX that carries the new number of
3634 template sibling parameters of T.
3636 2/ T has a new canonical type that matches the new number
3639 3/ From now on, T is going to be what lookups referring to the
3640 name of TYPE will return. No lookup should return TYPE anymore.
3642 NUM_PARMS is the new number of sibling parms TYPE belongs to.
3644 This is a subroutine of fixup_template_parms. */
3647 fixup_template_type_parm_type (tree type, int num_parms)
3649 tree orig_idx = TEMPLATE_TYPE_PARM_INDEX (type), idx;
3651 /* This is the decl which name is inserted into the symbol table for
3652 the template parm type. So whenever we lookup the type name, this
3653 is the DECL we get. */
3656 /* Do not fix up the type twice. */
3657 if (orig_idx && TEMPLATE_PARM_NUM_SIBLINGS (orig_idx) != 0)
3660 t = copy_type (type);
3661 decl = TYPE_NAME (t);
3663 TYPE_MAIN_VARIANT (t) = t;
3664 TYPE_NEXT_VARIANT (t)= NULL_TREE;
3665 TYPE_POINTER_TO (t) = 0;
3666 TYPE_REFERENCE_TO (t) = 0;
3668 idx = build_template_parm_index (TEMPLATE_PARM_IDX (orig_idx),
3669 TEMPLATE_PARM_LEVEL (orig_idx),
3670 TEMPLATE_PARM_ORIG_LEVEL (orig_idx),
3673 TEMPLATE_PARM_DESCENDANTS (idx) = TEMPLATE_PARM_DESCENDANTS (orig_idx);
3674 TEMPLATE_PARM_PARAMETER_PACK (idx) = TEMPLATE_PARM_PARAMETER_PACK (orig_idx);
3675 TEMPLATE_TYPE_PARM_INDEX (t) = idx;
3677 TYPE_STUB_DECL (t) = decl;
3678 TEMPLATE_TYPE_DECL (t) = decl;
3679 if (TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM)
3680 TREE_TYPE (DECL_TEMPLATE_RESULT (decl)) = t;
3682 /* Update the type associated to the type name stored in the symbol
3683 table. Now, whenever the type name is looked up, the resulting
3684 type is properly fixed up. */
3685 TREE_TYPE (decl) = t;
3687 TYPE_CANONICAL (t) = canonical_type_parameter (t);
3692 /* Create and return a new TEMPLATE_PARM_INDEX that is almost
3693 identical to I, but that is fixed up as to:
3695 1/ carry the number of sibling parms (NUM_PARMS) of the template
3696 parm represented by I.
3698 2/ replace all references to template parm types declared before I
3699 (in the same template parm list as I) by references to template
3700 parm types contained in ARGS. ARGS should contain the list of
3701 template parms that have been fixed up so far, in a form suitable
3702 to be passed to tsubst.
3704 This is a subroutine of fixup_template_parms. */
3707 fixup_template_parm_index (tree i, tree args, int num_parms)
3709 tree index, decl, type;
3712 || TREE_CODE (i) != TEMPLATE_PARM_INDEX
3713 /* Do not fix up the index twice. */
3714 || (TEMPLATE_PARM_NUM_SIBLINGS (i) != 0))
3717 decl = TEMPLATE_PARM_DECL (i);
3718 type = TREE_TYPE (decl);
3720 index = build_template_parm_index (TEMPLATE_PARM_IDX (i),
3721 TEMPLATE_PARM_LEVEL (i),
3722 TEMPLATE_PARM_ORIG_LEVEL (i),
3726 TEMPLATE_PARM_DESCENDANTS (index) = TEMPLATE_PARM_DESCENDANTS (i);
3727 TEMPLATE_PARM_PARAMETER_PACK (index) = TEMPLATE_PARM_PARAMETER_PACK (i);
3729 type = tsubst (type, args, tf_none, NULL_TREE);
3731 TREE_TYPE (decl) = type;
3732 TREE_TYPE (index) = type;
3738 This is a subroutine of fixup_template_parms.
3740 It computes the canonical type of the type of the template
3741 parameter PARM_DESC and update all references to that type so that
3742 they use the newly computed canonical type. No access check is
3743 performed during the fixup. PARM_DESC is a TREE_LIST which
3744 TREE_VALUE is the template parameter and its TREE_PURPOSE is the
3745 default argument of the template parm if any. IDX is the index of
3746 the template parameter, starting at 0. NUM_PARMS is the number of
3747 template parameters in the set PARM_DESC belongs to. ARGLIST is a
3748 TREE_VEC containing the full set of template parameters in a form
3749 suitable to be passed to substs functions as their ARGS
3750 argument. This is what current_template_args returns for a given
3751 template. The innermost vector of args in ARGLIST is the set of
3752 template parms that have been fixed up so far. This function adds
3753 the fixed up parameter into that vector. */
3756 fixup_template_parm (tree parm_desc,
3761 tree parm = TREE_VALUE (parm_desc);
3762 tree fixedup_args = INNERMOST_TEMPLATE_ARGS (arglist);
3764 push_deferring_access_checks (dk_no_check);
3766 if (TREE_CODE (parm) == TYPE_DECL)
3768 /* PARM is a template type parameter. Fix up its type, add
3769 the fixed-up template parm to the vector of fixed-up
3770 template parms so far, and substitute the fixed-up
3771 template parms into the default argument of this
3774 fixup_template_type_parm_type (TREE_TYPE (parm), num_parms);
3775 TREE_TYPE (parm) = t;
3777 TREE_VEC_ELT (fixedup_args, idx) = template_parm_to_arg (parm_desc);
3779 else if (TREE_CODE (parm) == TEMPLATE_DECL)
3781 /* PARM is a template template parameter. This is going to
3783 tree tparms, targs, innermost_args, t;
3786 /* First, fix up the parms of the template template parm
3787 because the parms are involved in defining the new canonical
3788 type of the template template parm. */
3790 /* So we need to substitute the template parm types that have
3791 been fixed up so far into the template parms of this template
3792 template parm. E.g, consider this:
3794 template<class T, template<T u> class TT> class S;
3796 In this case we want to substitute T into the
3797 template parameters of TT.
3799 So let's walk the template parms of PARM here, and
3800 tsubst ARGLIST into into each of the template
3803 /* For this substitution we need to build the full set of
3804 template parameters and use that as arguments for the
3805 tsubsting function. */
3806 tparms = INNERMOST_TEMPLATE_PARMS (DECL_TEMPLATE_PARMS (parm));
3808 /* This will contain the innermost parms of PARM into which
3809 we have substituted so far. */
3810 innermost_args = make_tree_vec (TREE_VEC_LENGTH (tparms));
3811 targs = add_to_template_args (arglist, innermost_args);
3812 for (j = 0; j < TREE_VEC_LENGTH (tparms); ++j)
3816 parameter = TREE_VEC_ELT (tparms, j);
3818 /* INNERMOST_ARGS needs to have at least the same number
3819 of elements as the index PARAMETER, ortherwise
3820 tsubsting into PARAMETER will result in partially
3821 instantiating it, reducing its tempate parm
3822 level. Let's tactically fill INNERMOST_ARGS for that
3824 TREE_VEC_ELT (innermost_args, j) =
3825 template_parm_to_arg (parameter);
3827 fixup_template_parm (parameter, j,
3828 TREE_VEC_LENGTH (tparms),
3832 /* Now fix up the type of the template template parm. */
3834 t = fixup_template_type_parm_type (TREE_TYPE (parm), num_parms);
3835 TREE_TYPE (parm) = t;
3837 TREE_VEC_ELT (fixedup_args, idx) =
3838 template_parm_to_arg (parm_desc);
3840 else if (TREE_CODE (parm) == PARM_DECL)
3842 /* PARM is a non-type template parameter. We need to:
3844 * Fix up its TEMPLATE_PARM_INDEX to make it carry the
3845 proper number of sibling parameters.
3847 * Make lookups of the template parameter return a reference
3848 to the fixed-up index. No lookup should return references
3849 to the former index anymore.
3851 * Substitute the template parms that got fixed up so far
3853 * into the type of PARM. */
3855 tree index = DECL_INITIAL (parm);
3857 /* PUSHED_DECL is the decl added to the symbol table with
3858 the name of the parameter. E,g:
3860 template<class T, T u> //#0
3861 auto my_function(T t) -> decltype(u); //#1
3863 Here, when looking up u at //#1, we get the decl of u
3864 resulting from the declaration in #0. This is what
3865 PUSHED_DECL is. We need to replace the reference to the
3866 old TEMPLATE_PARM_INDEX carried by PUSHED_DECL by the
3867 fixed-up TEMPLATE_PARM_INDEX. */
3868 tree pushed_decl = TEMPLATE_PARM_DECL (index);
3870 /* Let's fix up the TEMPLATE_PARM_INDEX then. Note that we must
3871 fixup the type of PUSHED_DECL as well and luckily
3872 fixup_template_parm_index does it for us too. */
3873 tree fixed_up_index =
3874 fixup_template_parm_index (index, arglist, num_parms);
3876 DECL_INITIAL (pushed_decl) = DECL_INITIAL (parm) = fixed_up_index;
3878 /* Add this fixed up PARM to the template parms we've fixed
3879 up so far and use that to substitute the fixed-up
3880 template parms into the type of PARM. */
3881 TREE_VEC_ELT (fixedup_args, idx) =
3882 template_parm_to_arg (parm_desc);
3883 TREE_TYPE (parm) = tsubst (TREE_TYPE (parm), arglist,
3884 tf_none, NULL_TREE);
3887 TREE_PURPOSE (parm_desc) =
3888 tsubst_template_arg (TREE_PURPOSE (parm_desc),
3889 arglist, tf_none, parm);
3891 pop_deferring_access_checks ();
3894 /* Walk the current template parms and properly compute the canonical
3895 types of the dependent types created during
3896 cp_parser_template_parameter_list. */
3899 fixup_template_parms (void)
3906 parameter_vec = INNERMOST_TEMPLATE_PARMS (current_template_parms);
3907 if (parameter_vec == NULL_TREE)
3910 num_parms = TREE_VEC_LENGTH (parameter_vec);
3912 /* This vector contains the current innermost template parms that
3913 have been fixed up so far. The form of FIXEDUP_ARGS is suitable
3914 to be passed to tsubst* functions as their ARGS argument. */
3915 fixedup_args = make_tree_vec (num_parms);
3917 /* This vector contains the full set of template parms in a form
3918 suitable to be passed to substs functions as their ARGS
3920 arglist = current_template_args ();
3921 arglist = add_outermost_template_args (arglist, fixedup_args);
3923 /* Let's do the proper fixup now. */
3924 for (i = 0; i < num_parms; ++i)
3925 fixup_template_parm (TREE_VEC_ELT (parameter_vec, i),
3926 i, num_parms, arglist);
3929 /* end_template_decl is called after a template declaration is seen. */
3932 end_template_decl (void)
3934 reset_specialization ();
3936 if (! processing_template_decl)
3939 /* This matches the pushlevel in begin_template_parm_list. */
3942 --processing_template_decl;
3943 current_template_parms = TREE_CHAIN (current_template_parms);
3946 /* Takes a TREE_LIST representing a template parameter and convert it
3947 into an argument suitable to be passed to the type substitution
3948 functions. Note that If the TREE_LIST contains an error_mark
3949 node, the returned argument is error_mark_node. */
3952 template_parm_to_arg (tree t)
3956 || TREE_CODE (t) != TREE_LIST)
3959 if (error_operand_p (TREE_VALUE (t)))
3960 return error_mark_node;
3964 if (TREE_CODE (t) == TYPE_DECL
3965 || TREE_CODE (t) == TEMPLATE_DECL)
3969 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
3971 /* Turn this argument into a TYPE_ARGUMENT_PACK
3972 with a single element, which expands T. */
3973 tree vec = make_tree_vec (1);
3974 #ifdef ENABLE_CHECKING
3975 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3976 (vec, TREE_VEC_LENGTH (vec));
3978 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
3980 t = cxx_make_type (TYPE_ARGUMENT_PACK);
3981 SET_ARGUMENT_PACK_ARGS (t, vec);
3986 t = DECL_INITIAL (t);
3988 if (TEMPLATE_PARM_PARAMETER_PACK (t))
3990 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3991 with a single element, which expands T. */
3992 tree vec = make_tree_vec (1);
3993 tree type = TREE_TYPE (TEMPLATE_PARM_DECL (t));
3994 #ifdef ENABLE_CHECKING
3995 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3996 (vec, TREE_VEC_LENGTH (vec));
3998 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
4000 t = make_node (NONTYPE_ARGUMENT_PACK);
4001 SET_ARGUMENT_PACK_ARGS (t, vec);
4002 TREE_TYPE (t) = type;
4008 /* Within the declaration of a template, return all levels of template
4009 parameters that apply. The template parameters are represented as
4010 a TREE_VEC, in the form documented in cp-tree.h for template
4014 current_template_args (void)
4017 tree args = NULL_TREE;
4018 int length = TMPL_PARMS_DEPTH (current_template_parms);
4021 /* If there is only one level of template parameters, we do not
4022 create a TREE_VEC of TREE_VECs. Instead, we return a single
4023 TREE_VEC containing the arguments. */
4025 args = make_tree_vec (length);
4027 for (header = current_template_parms; header; header = TREE_CHAIN (header))
4029 tree a = copy_node (TREE_VALUE (header));
4032 TREE_TYPE (a) = NULL_TREE;
4033 for (i = TREE_VEC_LENGTH (a) - 1; i >= 0; --i)
4034 TREE_VEC_ELT (a, i) = template_parm_to_arg (TREE_VEC_ELT (a, i));
4036 #ifdef ENABLE_CHECKING
4037 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (a, TREE_VEC_LENGTH (a));
4041 TREE_VEC_ELT (args, --l) = a;
4046 if (length > 1 && TREE_VEC_ELT (args, 0) == NULL_TREE)
4047 /* This can happen for template parms of a template template
4050 template<template<class T, class U> class TT> struct S;
4052 Consider the level of the parms of TT; T and U both have
4053 level 2; TT has no template parm of level 1. So in this case
4054 the first element of full_template_args is NULL_TREE. If we
4055 leave it like this TMPL_ARG_DEPTH on args returns 1 instead
4056 of 2. This will make tsubst wrongly consider that T and U
4057 have level 1. Instead, let's create a dummy vector as the
4058 first element of full_template_args so that TMPL_ARG_DEPTH
4059 returns the correct depth for args. */
4060 TREE_VEC_ELT (args, 0) = make_tree_vec (1);
4064 /* Update the declared TYPE by doing any lookups which were thought to be
4065 dependent, but are not now that we know the SCOPE of the declarator. */
4068 maybe_update_decl_type (tree orig_type, tree scope)
4070 tree type = orig_type;
4072 if (type == NULL_TREE)
4075 if (TREE_CODE (orig_type) == TYPE_DECL)
4076 type = TREE_TYPE (type);
4078 if (scope && TYPE_P (scope) && dependent_type_p (scope)
4079 && dependent_type_p (type)
4080 /* Don't bother building up the args in this case. */
4081 && TREE_CODE (type) != TEMPLATE_TYPE_PARM)
4083 /* tsubst in the args corresponding to the template parameters,
4084 including auto if present. Most things will be unchanged, but
4085 make_typename_type and tsubst_qualified_id will resolve
4086 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4087 tree args = current_template_args ();
4088 tree auto_node = type_uses_auto (type);
4092 tree auto_vec = make_tree_vec (1);
4093 TREE_VEC_ELT (auto_vec, 0) = auto_node;
4094 args = add_to_template_args (args, auto_vec);
4096 pushed = push_scope (scope);
4097 type = tsubst (type, args, tf_warning_or_error, NULL_TREE);
4102 if (type == error_mark_node)
4105 if (TREE_CODE (orig_type) == TYPE_DECL)
4107 if (same_type_p (type, TREE_TYPE (orig_type)))
4110 type = TYPE_NAME (type);
4115 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4116 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
4117 a member template. Used by push_template_decl below. */
4120 build_template_decl (tree decl, tree parms, bool member_template_p)
4122 tree tmpl = build_lang_decl (TEMPLATE_DECL, DECL_NAME (decl), NULL_TREE);
4123 DECL_TEMPLATE_PARMS (tmpl) = parms;
4124 DECL_CONTEXT (tmpl) = DECL_CONTEXT (decl);
4125 DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl);
4126 DECL_MEMBER_TEMPLATE_P (tmpl) = member_template_p;
4131 struct template_parm_data
4133 /* The level of the template parameters we are currently
4137 /* The index of the specialization argument we are currently
4141 /* An array whose size is the number of template parameters. The
4142 elements are nonzero if the parameter has been used in any one
4143 of the arguments processed so far. */
4146 /* An array whose size is the number of template arguments. The
4147 elements are nonzero if the argument makes use of template
4148 parameters of this level. */
4149 int* arg_uses_template_parms;
4152 /* Subroutine of push_template_decl used to see if each template
4153 parameter in a partial specialization is used in the explicit
4154 argument list. If T is of the LEVEL given in DATA (which is
4155 treated as a template_parm_data*), then DATA->PARMS is marked
4159 mark_template_parm (tree t, void* data)
4163 struct template_parm_data* tpd = (struct template_parm_data*) data;
4165 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
4167 level = TEMPLATE_PARM_LEVEL (t);
4168 idx = TEMPLATE_PARM_IDX (t);
4172 level = TEMPLATE_TYPE_LEVEL (t);
4173 idx = TEMPLATE_TYPE_IDX (t);
4176 if (level == tpd->level)
4178 tpd->parms[idx] = 1;
4179 tpd->arg_uses_template_parms[tpd->current_arg] = 1;
4182 /* Return zero so that for_each_template_parm will continue the
4183 traversal of the tree; we want to mark *every* template parm. */
4187 /* Process the partial specialization DECL. */
4190 process_partial_specialization (tree decl)
4192 tree type = TREE_TYPE (decl);
4193 tree maintmpl = CLASSTYPE_TI_TEMPLATE (type);
4194 tree specargs = CLASSTYPE_TI_ARGS (type);
4195 tree inner_args = INNERMOST_TEMPLATE_ARGS (specargs);
4196 tree main_inner_parms = DECL_INNERMOST_TEMPLATE_PARMS (maintmpl);
4199 int nargs = TREE_VEC_LENGTH (inner_args);
4202 bool did_error_intro = false;
4203 struct template_parm_data tpd;
4204 struct template_parm_data tpd2;
4206 gcc_assert (current_template_parms);
4208 inner_parms = INNERMOST_TEMPLATE_PARMS (current_template_parms);
4209 ntparms = TREE_VEC_LENGTH (inner_parms);
4211 /* We check that each of the template parameters given in the
4212 partial specialization is used in the argument list to the
4213 specialization. For example:
4215 template <class T> struct S;
4216 template <class T> struct S<T*>;
4218 The second declaration is OK because `T*' uses the template
4219 parameter T, whereas
4221 template <class T> struct S<int>;
4223 is no good. Even trickier is:
4234 The S2<T> declaration is actually invalid; it is a
4235 full-specialization. Of course,
4238 struct S2<T (*)(U)>;
4240 or some such would have been OK. */
4241 tpd.level = TMPL_PARMS_DEPTH (current_template_parms);
4242 tpd.parms = XALLOCAVEC (int, ntparms);
4243 memset (tpd.parms, 0, sizeof (int) * ntparms);
4245 tpd.arg_uses_template_parms = XALLOCAVEC (int, nargs);
4246 memset (tpd.arg_uses_template_parms, 0, sizeof (int) * nargs);
4247 for (i = 0; i < nargs; ++i)
4249 tpd.current_arg = i;
4250 for_each_template_parm (TREE_VEC_ELT (inner_args, i),
4251 &mark_template_parm,
4254 /*include_nondeduced_p=*/false);
4256 for (i = 0; i < ntparms; ++i)
4257 if (tpd.parms[i] == 0)
4259 /* One of the template parms was not used in the
4261 if (!did_error_intro)
4263 error ("template parameters not used in partial specialization:");
4264 did_error_intro = true;
4267 error (" %qD", TREE_VALUE (TREE_VEC_ELT (inner_parms, i)));
4270 if (did_error_intro)
4271 return error_mark_node;
4273 /* [temp.class.spec]
4275 The argument list of the specialization shall not be identical to
4276 the implicit argument list of the primary template. */
4277 if (comp_template_args
4279 INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE
4281 error ("partial specialization %qT does not specialize any template arguments", type);
4283 /* [temp.class.spec]
4285 A partially specialized non-type argument expression shall not
4286 involve template parameters of the partial specialization except
4287 when the argument expression is a simple identifier.
4289 The type of a template parameter corresponding to a specialized
4290 non-type argument shall not be dependent on a parameter of the
4293 Also, we verify that pack expansions only occur at the
4294 end of the argument list. */
4295 gcc_assert (nargs == DECL_NTPARMS (maintmpl));
4297 for (i = 0; i < nargs; ++i)
4299 tree parm = TREE_VALUE (TREE_VEC_ELT (main_inner_parms, i));
4300 tree arg = TREE_VEC_ELT (inner_args, i);
4301 tree packed_args = NULL_TREE;
4304 if (ARGUMENT_PACK_P (arg))
4306 /* Extract the arguments from the argument pack. We'll be
4307 iterating over these in the following loop. */
4308 packed_args = ARGUMENT_PACK_ARGS (arg);
4309 len = TREE_VEC_LENGTH (packed_args);
4312 for (j = 0; j < len; j++)
4315 /* Get the Jth argument in the parameter pack. */
4316 arg = TREE_VEC_ELT (packed_args, j);
4318 if (PACK_EXPANSION_P (arg))
4320 /* Pack expansions must come at the end of the
4322 if ((packed_args && j < len - 1)
4323 || (!packed_args && i < nargs - 1))
4325 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
4326 error ("parameter pack argument %qE must be at the "
4327 "end of the template argument list", arg);
4329 error ("parameter pack argument %qT must be at the "
4330 "end of the template argument list", arg);
4334 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
4335 /* We only care about the pattern. */
4336 arg = PACK_EXPANSION_PATTERN (arg);
4338 if (/* These first two lines are the `non-type' bit. */
4340 && TREE_CODE (arg) != TEMPLATE_DECL
4341 /* This next line is the `argument expression is not just a
4342 simple identifier' condition and also the `specialized
4343 non-type argument' bit. */
4344 && TREE_CODE (arg) != TEMPLATE_PARM_INDEX)
4346 if ((!packed_args && tpd.arg_uses_template_parms[i])
4347 || (packed_args && uses_template_parms (arg)))
4348 error ("template argument %qE involves template parameter(s)",
4352 /* Look at the corresponding template parameter,
4353 marking which template parameters its type depends
4355 tree type = TREE_TYPE (parm);
4359 /* We haven't yet initialized TPD2. Do so now. */
4360 tpd2.arg_uses_template_parms = XALLOCAVEC (int, nargs);
4361 /* The number of parameters here is the number in the
4362 main template, which, as checked in the assertion
4364 tpd2.parms = XALLOCAVEC (int, nargs);
4366 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (maintmpl));
4369 /* Mark the template parameters. But this time, we're
4370 looking for the template parameters of the main
4371 template, not in the specialization. */
4372 tpd2.current_arg = i;
4373 tpd2.arg_uses_template_parms[i] = 0;
4374 memset (tpd2.parms, 0, sizeof (int) * nargs);
4375 for_each_template_parm (type,
4376 &mark_template_parm,
4379 /*include_nondeduced_p=*/false);
4381 if (tpd2.arg_uses_template_parms [i])
4383 /* The type depended on some template parameters.
4384 If they are fully specialized in the
4385 specialization, that's OK. */
4388 for (j = 0; j < nargs; ++j)
4389 if (tpd2.parms[j] != 0
4390 && tpd.arg_uses_template_parms [j])
4393 error_n (input_location, count,
4394 "type %qT of template argument %qE depends "
4395 "on a template parameter",
4396 "type %qT of template argument %qE depends "
4397 "on template parameters",
4406 /* We should only get here once. */
4407 gcc_assert (!COMPLETE_TYPE_P (type));
4409 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)
4410 = tree_cons (specargs, inner_parms,
4411 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl));
4412 TREE_TYPE (DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)) = type;
4414 for (inst = DECL_TEMPLATE_INSTANTIATIONS (maintmpl); inst;
4415 inst = TREE_CHAIN (inst))
4417 tree inst_type = TREE_VALUE (inst);
4418 if (COMPLETE_TYPE_P (inst_type)
4419 && CLASSTYPE_IMPLICIT_INSTANTIATION (inst_type))
4421 tree spec = most_specialized_class (inst_type, maintmpl, tf_none);
4422 if (spec && TREE_TYPE (spec) == type)
4423 permerror (input_location,
4424 "partial specialization of %qT after instantiation "
4425 "of %qT", type, inst_type);
4432 /* Check that a template declaration's use of default arguments and
4433 parameter packs is not invalid. Here, PARMS are the template
4434 parameters. IS_PRIMARY is nonzero if DECL is the thing declared by
4435 a primary template. IS_PARTIAL is nonzero if DECL is a partial
4439 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4440 declaration (but not a definition); 1 indicates a declaration, 2
4441 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4442 emitted for extraneous default arguments.
4444 Returns TRUE if there were no errors found, FALSE otherwise. */
4447 check_default_tmpl_args (tree decl, tree parms, int is_primary,
4448 int is_partial, int is_friend_decl)
4451 int last_level_to_check;
4453 bool no_errors = true;
4457 A default template-argument shall not be specified in a
4458 function template declaration or a function template definition, nor
4459 in the template-parameter-list of the definition of a member of a
4462 if (TREE_CODE (CP_DECL_CONTEXT (decl)) == FUNCTION_DECL)
4463 /* You can't have a function template declaration in a local
4464 scope, nor you can you define a member of a class template in a
4468 if (current_class_type
4469 && !TYPE_BEING_DEFINED (current_class_type)
4470 && DECL_LANG_SPECIFIC (decl)
4471 && DECL_DECLARES_FUNCTION_P (decl)
4472 /* If this is either a friend defined in the scope of the class
4473 or a member function. */
4474 && (DECL_FUNCTION_MEMBER_P (decl)
4475 ? same_type_p (DECL_CONTEXT (decl), current_class_type)
4476 : DECL_FRIEND_CONTEXT (decl)
4477 ? same_type_p (DECL_FRIEND_CONTEXT (decl), current_class_type)
4479 /* And, if it was a member function, it really was defined in
4480 the scope of the class. */
4481 && (!DECL_FUNCTION_MEMBER_P (decl)
4482 || DECL_INITIALIZED_IN_CLASS_P (decl)))
4483 /* We already checked these parameters when the template was
4484 declared, so there's no need to do it again now. This function
4485 was defined in class scope, but we're processing it's body now
4486 that the class is complete. */
4489 /* Core issue 226 (C++0x only): the following only applies to class
4491 if ((cxx_dialect == cxx98) || TREE_CODE (decl) != FUNCTION_DECL)
4495 If a template-parameter has a default template-argument, all
4496 subsequent template-parameters shall have a default
4497 template-argument supplied. */
4498 for (parm_level = parms; parm_level; parm_level = TREE_CHAIN (parm_level))
4500 tree inner_parms = TREE_VALUE (parm_level);
4501 int ntparms = TREE_VEC_LENGTH (inner_parms);
4502 int seen_def_arg_p = 0;
4505 for (i = 0; i < ntparms; ++i)
4507 tree parm = TREE_VEC_ELT (inner_parms, i);
4509 if (parm == error_mark_node)
4512 if (TREE_PURPOSE (parm))
4514 else if (seen_def_arg_p
4515 && !template_parameter_pack_p (TREE_VALUE (parm)))
4517 error ("no default argument for %qD", TREE_VALUE (parm));
4518 /* For better subsequent error-recovery, we indicate that
4519 there should have been a default argument. */
4520 TREE_PURPOSE (parm) = error_mark_node;
4526 /* Don't complain about an enclosing partial
4528 && parm_level == parms
4529 && TREE_CODE (decl) == TYPE_DECL
4531 && template_parameter_pack_p (TREE_VALUE (parm)))
4533 /* A primary class template can only have one
4534 parameter pack, at the end of the template
4537 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL)
4538 error ("parameter pack %qE must be at the end of the"
4539 " template parameter list", TREE_VALUE (parm));
4541 error ("parameter pack %qT must be at the end of the"
4542 " template parameter list",
4543 TREE_TYPE (TREE_VALUE (parm)));
4545 TREE_VALUE (TREE_VEC_ELT (inner_parms, i))
4553 if (((cxx_dialect == cxx98) && TREE_CODE (decl) != TYPE_DECL)
4557 /* For an ordinary class template, default template arguments are
4558 allowed at the innermost level, e.g.:
4559 template <class T = int>
4561 but, in a partial specialization, they're not allowed even
4562 there, as we have in [temp.class.spec]:
4564 The template parameter list of a specialization shall not
4565 contain default template argument values.
4567 So, for a partial specialization, or for a function template
4568 (in C++98/C++03), we look at all of them. */
4571 /* But, for a primary class template that is not a partial
4572 specialization we look at all template parameters except the
4574 parms = TREE_CHAIN (parms);
4576 /* Figure out what error message to issue. */
4577 if (is_friend_decl == 2)
4578 msg = G_("default template arguments may not be used in function template "
4579 "friend re-declaration");
4580 else if (is_friend_decl)
4581 msg = G_("default template arguments may not be used in function template "
4582 "friend declarations");
4583 else if (TREE_CODE (decl) == FUNCTION_DECL && (cxx_dialect == cxx98))
4584 msg = G_("default template arguments may not be used in function templates "
4585 "without -std=c++0x or -std=gnu++0x");
4586 else if (is_partial)
4587 msg = G_("default template arguments may not be used in "
4588 "partial specializations");
4590 msg = G_("default argument for template parameter for class enclosing %qD");
4592 if (current_class_type && TYPE_BEING_DEFINED (current_class_type))
4593 /* If we're inside a class definition, there's no need to
4594 examine the parameters to the class itself. On the one
4595 hand, they will be checked when the class is defined, and,
4596 on the other, default arguments are valid in things like:
4597 template <class T = double>
4598 struct S { template <class U> void f(U); };
4599 Here the default argument for `S' has no bearing on the
4600 declaration of `f'. */
4601 last_level_to_check = template_class_depth (current_class_type) + 1;
4603 /* Check everything. */
4604 last_level_to_check = 0;
4606 for (parm_level = parms;
4607 parm_level && TMPL_PARMS_DEPTH (parm_level) >= last_level_to_check;
4608 parm_level = TREE_CHAIN (parm_level))
4610 tree inner_parms = TREE_VALUE (parm_level);
4614 ntparms = TREE_VEC_LENGTH (inner_parms);
4615 for (i = 0; i < ntparms; ++i)
4617 if (TREE_VEC_ELT (inner_parms, i) == error_mark_node)
4620 if (TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)))
4625 if (is_friend_decl == 2)
4632 /* Clear out the default argument so that we are not
4634 TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)) = NULL_TREE;
4638 /* At this point, if we're still interested in issuing messages,
4639 they must apply to classes surrounding the object declared. */
4641 msg = G_("default argument for template parameter for class "
4648 /* Worker for push_template_decl_real, called via
4649 for_each_template_parm. DATA is really an int, indicating the
4650 level of the parameters we are interested in. If T is a template
4651 parameter of that level, return nonzero. */
4654 template_parm_this_level_p (tree t, void* data)
4656 int this_level = *(int *)data;
4659 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
4660 level = TEMPLATE_PARM_LEVEL (t);
4662 level = TEMPLATE_TYPE_LEVEL (t);
4663 return level == this_level;
4666 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4667 parameters given by current_template_args, or reuses a
4668 previously existing one, if appropriate. Returns the DECL, or an
4669 equivalent one, if it is replaced via a call to duplicate_decls.
4671 If IS_FRIEND is true, DECL is a friend declaration. */
4674 push_template_decl_real (tree decl, bool is_friend)
4682 int new_template_p = 0;
4683 /* True if the template is a member template, in the sense of
4685 bool member_template_p = false;
4687 if (decl == error_mark_node || !current_template_parms)
4688 return error_mark_node;
4690 /* See if this is a partial specialization. */
4691 is_partial = (DECL_IMPLICIT_TYPEDEF_P (decl)
4692 && TREE_CODE (TREE_TYPE (decl)) != ENUMERAL_TYPE
4693 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)));
4695 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_FRIEND_P (decl))
4699 /* For a friend, we want the context of the friend function, not
4700 the type of which it is a friend. */
4701 ctx = CP_DECL_CONTEXT (decl);
4702 else if (CP_DECL_CONTEXT (decl)
4703 && TREE_CODE (CP_DECL_CONTEXT (decl)) != NAMESPACE_DECL)
4704 /* In the case of a virtual function, we want the class in which
4706 ctx = CP_DECL_CONTEXT (decl);
4708 /* Otherwise, if we're currently defining some class, the DECL
4709 is assumed to be a member of the class. */
4710 ctx = current_scope ();
4712 if (ctx && TREE_CODE (ctx) == NAMESPACE_DECL)
4715 if (!DECL_CONTEXT (decl))
4716 DECL_CONTEXT (decl) = FROB_CONTEXT (current_namespace);
4718 /* See if this is a primary template. */
4719 if (is_friend && ctx)
4720 /* A friend template that specifies a class context, i.e.
4721 template <typename T> friend void A<T>::f();
4725 primary = template_parm_scope_p ();
4729 if (DECL_CLASS_SCOPE_P (decl))
4730 member_template_p = true;
4731 if (TREE_CODE (decl) == TYPE_DECL
4732 && ANON_AGGRNAME_P (DECL_NAME (decl)))
4734 error ("template class without a name");
4735 return error_mark_node;
4737 else if (TREE_CODE (decl) == FUNCTION_DECL)
4739 if (DECL_DESTRUCTOR_P (decl))
4743 A destructor shall not be a member template. */
4744 error ("destructor %qD declared as member template", decl);
4745 return error_mark_node;
4747 if (NEW_DELETE_OPNAME_P (DECL_NAME (decl))
4748 && (!prototype_p (TREE_TYPE (decl))
4749 || TYPE_ARG_TYPES (TREE_TYPE (decl)) == void_list_node
4750 || !TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (decl)))
4751 || (TREE_CHAIN (TYPE_ARG_TYPES ((TREE_TYPE (decl))))
4752 == void_list_node)))
4754 /* [basic.stc.dynamic.allocation]
4756 An allocation function can be a function
4757 template. ... Template allocation functions shall
4758 have two or more parameters. */
4759 error ("invalid template declaration of %qD", decl);
4760 return error_mark_node;
4763 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4764 && CLASS_TYPE_P (TREE_TYPE (decl)))
4768 error ("template declaration of %q#D", decl);
4769 return error_mark_node;
4773 /* Check to see that the rules regarding the use of default
4774 arguments are not being violated. */
4775 check_default_tmpl_args (decl, current_template_parms,
4776 primary, is_partial, /*is_friend_decl=*/0);
4778 /* Ensure that there are no parameter packs in the type of this
4779 declaration that have not been expanded. */
4780 if (TREE_CODE (decl) == FUNCTION_DECL)
4782 /* Check each of the arguments individually to see if there are
4783 any bare parameter packs. */
4784 tree type = TREE_TYPE (decl);
4785 tree arg = DECL_ARGUMENTS (decl);
4786 tree argtype = TYPE_ARG_TYPES (type);
4788 while (arg && argtype)
4790 if (!FUNCTION_PARAMETER_PACK_P (arg)
4791 && check_for_bare_parameter_packs (TREE_TYPE (arg)))
4793 /* This is a PARM_DECL that contains unexpanded parameter
4794 packs. We have already complained about this in the
4795 check_for_bare_parameter_packs call, so just replace
4796 these types with ERROR_MARK_NODE. */
4797 TREE_TYPE (arg) = error_mark_node;
4798 TREE_VALUE (argtype) = error_mark_node;
4801 arg = DECL_CHAIN (arg);
4802 argtype = TREE_CHAIN (argtype);
4805 /* Check for bare parameter packs in the return type and the
4806 exception specifiers. */
4807 if (check_for_bare_parameter_packs (TREE_TYPE (type)))
4808 /* Errors were already issued, set return type to int
4809 as the frontend doesn't expect error_mark_node as
4811 TREE_TYPE (type) = integer_type_node;
4812 if (check_for_bare_parameter_packs (TYPE_RAISES_EXCEPTIONS (type)))
4813 TYPE_RAISES_EXCEPTIONS (type) = NULL_TREE;
4815 else if (check_for_bare_parameter_packs (TREE_TYPE (decl)))
4817 TREE_TYPE (decl) = error_mark_node;
4818 return error_mark_node;
4822 return process_partial_specialization (decl);
4824 args = current_template_args ();
4827 || TREE_CODE (ctx) == FUNCTION_DECL
4828 || (CLASS_TYPE_P (ctx) && TYPE_BEING_DEFINED (ctx))
4829 || (is_friend && !DECL_TEMPLATE_INFO (decl)))
4831 if (DECL_LANG_SPECIFIC (decl)
4832 && DECL_TEMPLATE_INFO (decl)
4833 && DECL_TI_TEMPLATE (decl))
4834 tmpl = DECL_TI_TEMPLATE (decl);
4835 /* If DECL is a TYPE_DECL for a class-template, then there won't
4836 be DECL_LANG_SPECIFIC. The information equivalent to
4837 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4838 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4839 && TYPE_TEMPLATE_INFO (TREE_TYPE (decl))
4840 && TYPE_TI_TEMPLATE (TREE_TYPE (decl)))
4842 /* Since a template declaration already existed for this
4843 class-type, we must be redeclaring it here. Make sure
4844 that the redeclaration is valid. */
4845 redeclare_class_template (TREE_TYPE (decl),
4846 current_template_parms);
4847 /* We don't need to create a new TEMPLATE_DECL; just use the
4848 one we already had. */
4849 tmpl = TYPE_TI_TEMPLATE (TREE_TYPE (decl));
4853 tmpl = build_template_decl (decl, current_template_parms,
4857 if (DECL_LANG_SPECIFIC (decl)
4858 && DECL_TEMPLATE_SPECIALIZATION (decl))
4860 /* A specialization of a member template of a template
4862 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
4863 DECL_TEMPLATE_INFO (tmpl) = DECL_TEMPLATE_INFO (decl);
4864 DECL_TEMPLATE_INFO (decl) = NULL_TREE;
4870 tree a, t, current, parms;
4872 tree tinfo = get_template_info (decl);
4876 error ("template definition of non-template %q#D", decl);
4877 return error_mark_node;
4880 tmpl = TI_TEMPLATE (tinfo);
4882 if (DECL_FUNCTION_TEMPLATE_P (tmpl)
4883 && DECL_TEMPLATE_INFO (decl) && DECL_TI_ARGS (decl)
4884 && DECL_TEMPLATE_SPECIALIZATION (decl)
4885 && DECL_MEMBER_TEMPLATE_P (tmpl))
4889 /* The declaration is a specialization of a member
4890 template, declared outside the class. Therefore, the
4891 innermost template arguments will be NULL, so we
4892 replace them with the arguments determined by the
4893 earlier call to check_explicit_specialization. */
4894 args = DECL_TI_ARGS (decl);
4897 = build_template_decl (decl, current_template_parms,
4899 DECL_TEMPLATE_RESULT (new_tmpl) = decl;
4900 TREE_TYPE (new_tmpl) = TREE_TYPE (decl);
4901 DECL_TI_TEMPLATE (decl) = new_tmpl;
4902 SET_DECL_TEMPLATE_SPECIALIZATION (new_tmpl);
4903 DECL_TEMPLATE_INFO (new_tmpl)
4904 = build_template_info (tmpl, args);
4906 register_specialization (new_tmpl,
4907 most_general_template (tmpl),
4913 /* Make sure the template headers we got make sense. */
4915 parms = DECL_TEMPLATE_PARMS (tmpl);
4916 i = TMPL_PARMS_DEPTH (parms);
4917 if (TMPL_ARGS_DEPTH (args) != i)
4919 error ("expected %d levels of template parms for %q#D, got %d",
4920 i, decl, TMPL_ARGS_DEPTH (args));
4923 for (current = decl; i > 0; --i, parms = TREE_CHAIN (parms))
4925 a = TMPL_ARGS_LEVEL (args, i);
4926 t = INNERMOST_TEMPLATE_PARMS (parms);
4928 if (TREE_VEC_LENGTH (t) != TREE_VEC_LENGTH (a))
4930 if (current == decl)
4931 error ("got %d template parameters for %q#D",
4932 TREE_VEC_LENGTH (a), decl);
4934 error ("got %d template parameters for %q#T",
4935 TREE_VEC_LENGTH (a), current);
4936 error (" but %d required", TREE_VEC_LENGTH (t));
4937 return error_mark_node;
4940 if (current == decl)
4942 else if (current == NULL_TREE)
4943 /* Can happen in erroneous input. */
4946 current = (TYPE_P (current)
4947 ? TYPE_CONTEXT (current)
4948 : DECL_CONTEXT (current));
4951 /* Check that the parms are used in the appropriate qualifying scopes
4952 in the declarator. */
4953 if (!comp_template_args
4955 TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (tmpl)))))
4958 template arguments to %qD do not match original template %qD",
4959 decl, DECL_TEMPLATE_RESULT (tmpl));
4960 if (!uses_template_parms (TI_ARGS (tinfo)))
4961 inform (input_location, "use template<> for an explicit specialization");
4962 /* Avoid crash in import_export_decl. */
4963 DECL_INTERFACE_KNOWN (decl) = 1;
4964 return error_mark_node;
4968 DECL_TEMPLATE_RESULT (tmpl) = decl;
4969 TREE_TYPE (tmpl) = TREE_TYPE (decl);
4971 /* Push template declarations for global functions and types. Note
4972 that we do not try to push a global template friend declared in a
4973 template class; such a thing may well depend on the template
4974 parameters of the class. */
4975 if (new_template_p && !ctx
4976 && !(is_friend && template_class_depth (current_class_type) > 0))
4978 tmpl = pushdecl_namespace_level (tmpl, is_friend);
4979 if (tmpl == error_mark_node)
4980 return error_mark_node;
4982 /* Hide template friend classes that haven't been declared yet. */
4983 if (is_friend && TREE_CODE (decl) == TYPE_DECL)
4985 DECL_ANTICIPATED (tmpl) = 1;
4986 DECL_FRIEND_P (tmpl) = 1;
4992 tree parms = DECL_TEMPLATE_PARMS (tmpl);
4995 DECL_PRIMARY_TEMPLATE (tmpl) = tmpl;
4996 if (DECL_CONV_FN_P (tmpl))
4998 int depth = TMPL_PARMS_DEPTH (parms);
5000 /* It is a conversion operator. See if the type converted to
5001 depends on innermost template operands. */
5003 if (uses_template_parms_level (TREE_TYPE (TREE_TYPE (tmpl)),
5005 DECL_TEMPLATE_CONV_FN_P (tmpl) = 1;
5008 /* Give template template parms a DECL_CONTEXT of the template
5009 for which they are a parameter. */
5010 parms = INNERMOST_TEMPLATE_PARMS (parms);
5011 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
5013 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
5014 if (TREE_CODE (parm) == TEMPLATE_DECL)
5015 DECL_CONTEXT (parm) = tmpl;
5019 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5020 back to its most general template. If TMPL is a specialization,
5021 ARGS may only have the innermost set of arguments. Add the missing
5022 argument levels if necessary. */
5023 if (DECL_TEMPLATE_INFO (tmpl))
5024 args = add_outermost_template_args (DECL_TI_ARGS (tmpl), args);
5026 info = build_template_info (tmpl, args);
5028 if (DECL_IMPLICIT_TYPEDEF_P (decl))
5029 SET_TYPE_TEMPLATE_INFO (TREE_TYPE (tmpl), info);
5030 else if (DECL_LANG_SPECIFIC (decl))
5031 DECL_TEMPLATE_INFO (decl) = info;
5033 return DECL_TEMPLATE_RESULT (tmpl);
5037 push_template_decl (tree decl)
5039 return push_template_decl_real (decl, false);
5042 /* Called when a class template TYPE is redeclared with the indicated
5043 template PARMS, e.g.:
5045 template <class T> struct S;
5046 template <class T> struct S {}; */
5049 redeclare_class_template (tree type, tree parms)
5055 if (!TYPE_TEMPLATE_INFO (type))
5057 error ("%qT is not a template type", type);
5061 tmpl = TYPE_TI_TEMPLATE (type);
5062 if (!PRIMARY_TEMPLATE_P (tmpl))
5063 /* The type is nested in some template class. Nothing to worry
5064 about here; there are no new template parameters for the nested
5070 error ("template specifiers not specified in declaration of %qD",
5075 parms = INNERMOST_TEMPLATE_PARMS (parms);
5076 tmpl_parms = DECL_INNERMOST_TEMPLATE_PARMS (tmpl);
5078 if (TREE_VEC_LENGTH (parms) != TREE_VEC_LENGTH (tmpl_parms))
5080 error_n (input_location, TREE_VEC_LENGTH (parms),
5081 "redeclared with %d template parameter",
5082 "redeclared with %d template parameters",
5083 TREE_VEC_LENGTH (parms));
5084 inform_n (input_location, TREE_VEC_LENGTH (tmpl_parms),
5085 "previous declaration %q+D used %d template parameter",
5086 "previous declaration %q+D used %d template parameters",
5087 tmpl, TREE_VEC_LENGTH (tmpl_parms));
5091 for (i = 0; i < TREE_VEC_LENGTH (tmpl_parms); ++i)
5098 if (TREE_VEC_ELT (tmpl_parms, i) == error_mark_node
5099 || TREE_VEC_ELT (parms, i) == error_mark_node)
5102 tmpl_parm = TREE_VALUE (TREE_VEC_ELT (tmpl_parms, i));
5103 if (tmpl_parm == error_mark_node)
5106 parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
5107 tmpl_default = TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i));
5108 parm_default = TREE_PURPOSE (TREE_VEC_ELT (parms, i));
5110 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5112 if (TREE_CODE (tmpl_parm) != TREE_CODE (parm)
5113 || (TREE_CODE (tmpl_parm) != TYPE_DECL
5114 && !same_type_p (TREE_TYPE (tmpl_parm), TREE_TYPE (parm)))
5115 || (TREE_CODE (tmpl_parm) != PARM_DECL
5116 && (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (tmpl_parm))
5117 != TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm))))
5118 || (TREE_CODE (tmpl_parm) == PARM_DECL
5119 && (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (tmpl_parm))
5120 != TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))))
5122 error ("template parameter %q+#D", tmpl_parm);
5123 error ("redeclared here as %q#D", parm);
5127 if (tmpl_default != NULL_TREE && parm_default != NULL_TREE)
5129 /* We have in [temp.param]:
5131 A template-parameter may not be given default arguments
5132 by two different declarations in the same scope. */
5133 error_at (input_location, "redefinition of default argument for %q#D", parm);
5134 inform (DECL_SOURCE_LOCATION (tmpl_parm),
5135 "original definition appeared here");
5139 if (parm_default != NULL_TREE)
5140 /* Update the previous template parameters (which are the ones
5141 that will really count) with the new default value. */
5142 TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i)) = parm_default;
5143 else if (tmpl_default != NULL_TREE)
5144 /* Update the new parameters, too; they'll be used as the
5145 parameters for any members. */
5146 TREE_PURPOSE (TREE_VEC_ELT (parms, i)) = tmpl_default;
5152 /* Simplify EXPR if it is a non-dependent expression. Returns the
5153 (possibly simplified) expression. */
5156 fold_non_dependent_expr_sfinae (tree expr, tsubst_flags_t complain)
5158 if (expr == NULL_TREE)
5161 /* If we're in a template, but EXPR isn't value dependent, simplify
5162 it. We're supposed to treat:
5164 template <typename T> void f(T[1 + 1]);
5165 template <typename T> void f(T[2]);
5167 as two declarations of the same function, for example. */
5168 if (processing_template_decl
5169 && !type_dependent_expression_p (expr)
5170 && potential_constant_expression (expr)
5171 && !value_dependent_expression_p (expr))
5173 HOST_WIDE_INT saved_processing_template_decl;
5175 saved_processing_template_decl = processing_template_decl;
5176 processing_template_decl = 0;
5177 expr = tsubst_copy_and_build (expr,
5180 /*in_decl=*/NULL_TREE,
5181 /*function_p=*/false,
5182 /*integral_constant_expression_p=*/true);
5183 processing_template_decl = saved_processing_template_decl;
5189 fold_non_dependent_expr (tree expr)
5191 return fold_non_dependent_expr_sfinae (expr, tf_error);
5194 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5195 must be a function or a pointer-to-function type, as specified
5196 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5197 and check that the resulting function has external linkage. */
5200 convert_nontype_argument_function (tree type, tree expr)
5205 fn = instantiate_type (type, fns, tf_none);
5206 if (fn == error_mark_node)
5207 return error_mark_node;
5210 if (TREE_CODE (fn_no_ptr) == ADDR_EXPR)
5211 fn_no_ptr = TREE_OPERAND (fn_no_ptr, 0);
5212 if (TREE_CODE (fn_no_ptr) == BASELINK)
5213 fn_no_ptr = BASELINK_FUNCTIONS (fn_no_ptr);
5215 /* [temp.arg.nontype]/1
5217 A template-argument for a non-type, non-template template-parameter
5220 -- the address of an object or function with external linkage. */
5221 if (!DECL_EXTERNAL_LINKAGE_P (fn_no_ptr))
5223 error ("%qE is not a valid template argument for type %qT "
5224 "because function %qD has not external linkage",
5225 expr, type, fn_no_ptr);
5232 /* Subroutine of convert_nontype_argument.
5233 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5234 Emit an error otherwise. */
5237 check_valid_ptrmem_cst_expr (tree type, tree expr,
5238 tsubst_flags_t complain)
5241 if (expr && (null_ptr_cst_p (expr) || TREE_CODE (expr) == PTRMEM_CST))
5243 if (complain & tf_error)
5245 error ("%qE is not a valid template argument for type %qT",
5247 error ("it must be a pointer-to-member of the form %<&X::Y%>");
5252 /* Returns TRUE iff the address of OP is value-dependent.
5254 14.6.2.4 [temp.dep.temp]:
5255 A non-integral non-type template-argument is dependent if its type is
5256 dependent or it has either of the following forms
5259 and contains a nested-name-specifier which specifies a class-name that
5260 names a dependent type.
5262 We generalize this to just say that the address of a member of a
5263 dependent class is value-dependent; the above doesn't cover the
5264 address of a static data member named with an unqualified-id. */
5267 has_value_dependent_address (tree op)
5269 /* We could use get_inner_reference here, but there's no need;
5270 this is only relevant for template non-type arguments, which
5271 can only be expressed as &id-expression. */
5274 tree ctx = CP_DECL_CONTEXT (op);
5275 if (TYPE_P (ctx) && dependent_type_p (ctx))
5282 /* The next set of functions are used for providing helpful explanatory
5283 diagnostics for failed overload resolution. Their messages should be
5284 indented by two spaces for consistency with the messages in
5288 unify_success (bool explain_p ATTRIBUTE_UNUSED)
5294 unify_parameter_deduction_failure (bool explain_p, tree parm)
5297 inform (input_location,
5298 " couldn't deduce template parameter %qD", parm);
5303 unify_invalid (bool explain_p ATTRIBUTE_UNUSED)
5309 unify_cv_qual_mismatch (bool explain_p, tree parm, tree arg)
5312 inform (input_location,
5313 " types %qT and %qT have incompatible cv-qualifiers",
5319 unify_type_mismatch (bool explain_p, tree parm, tree arg)
5322 inform (input_location, " mismatched types %qT and %qT", parm, arg);
5327 unify_parameter_pack_mismatch (bool explain_p, tree parm, tree arg)
5330 inform (input_location,
5331 " template parameter %qD is not a parameter pack, but "
5338 unify_ptrmem_cst_mismatch (bool explain_p, tree parm, tree arg)
5341 inform (input_location,
5342 " template argument %qE does not match "
5343 "pointer-to-member constant %qE",
5349 unify_expression_unequal (bool explain_p, tree parm, tree arg)
5352 inform (input_location, " %qE is not equivalent to %qE", parm, arg);
5357 unify_parameter_pack_inconsistent (bool explain_p, tree old_arg, tree new_arg)
5360 inform (input_location,
5361 " inconsistent parameter pack deduction with %qT and %qT",
5367 unify_inconsistency (bool explain_p, tree parm, tree first, tree second)
5370 inform (input_location,
5371 " deduced conflicting types for parameter %qT (%qT and %qT)",
5372 parm, first, second);
5377 unify_vla_arg (bool explain_p, tree arg)
5380 inform (input_location,
5381 " variable-sized array type %qT is not "
5382 "a valid template argument",
5388 unify_method_type_error (bool explain_p, tree arg)
5391 inform (input_location,
5392 " member function type %qT is not a valid template argument",
5398 unify_arity (bool explain_p, int have, int wanted)
5401 inform_n (input_location, wanted,
5402 " candidate expects %d argument, %d provided",
5403 " candidate expects %d arguments, %d provided",
5409 unify_too_many_arguments (bool explain_p, int have, int wanted)
5411 return unify_arity (explain_p, have, wanted);
5415 unify_too_few_arguments (bool explain_p, int have, int wanted)
5417 return unify_arity (explain_p, have, wanted);
5421 unify_arg_conversion (bool explain_p, tree to_type,
5422 tree from_type, tree arg)
5425 inform (input_location, " cannot convert %qE (type %qT) to type %qT",
5426 arg, from_type, to_type);
5431 unify_no_common_base (bool explain_p, enum template_base_result r,
5432 tree parm, tree arg)
5437 case tbr_ambiguous_baseclass:
5438 inform (input_location, " %qT is an ambiguous base class of %qT",
5442 inform (input_location, " %qT is not derived from %qT", arg, parm);
5449 unify_inconsistent_template_template_parameters (bool explain_p)
5452 inform (input_location,
5453 " template parameters of a template template argument are "
5454 "inconsistent with other deduced template arguments");
5459 unify_template_deduction_failure (bool explain_p, tree parm, tree arg)
5462 inform (input_location,
5463 " can't deduce a template for %qT from non-template type %qT",
5469 unify_template_argument_mismatch (bool explain_p, tree parm, tree arg)
5472 inform (input_location,
5473 " template argument %qE does not match %qD", arg, parm);
5478 unify_overload_resolution_failure (bool explain_p, tree arg)
5481 inform (input_location,
5482 " could not resolve address from overloaded function %qE",
5487 /* Attempt to convert the non-type template parameter EXPR to the
5488 indicated TYPE. If the conversion is successful, return the
5489 converted value. If the conversion is unsuccessful, return
5490 NULL_TREE if we issued an error message, or error_mark_node if we
5491 did not. We issue error messages for out-and-out bad template
5492 parameters, but not simply because the conversion failed, since we
5493 might be just trying to do argument deduction. Both TYPE and EXPR
5494 must be non-dependent.
5496 The conversion follows the special rules described in
5497 [temp.arg.nontype], and it is much more strict than an implicit
5500 This function is called twice for each template argument (see
5501 lookup_template_class for a more accurate description of this
5502 problem). This means that we need to handle expressions which
5503 are not valid in a C++ source, but can be created from the
5504 first call (for instance, casts to perform conversions). These
5505 hacks can go away after we fix the double coercion problem. */
5508 convert_nontype_argument (tree type, tree expr, tsubst_flags_t complain)
5512 /* Detect immediately string literals as invalid non-type argument.
5513 This special-case is not needed for correctness (we would easily
5514 catch this later), but only to provide better diagnostic for this
5515 common user mistake. As suggested by DR 100, we do not mention
5516 linkage issues in the diagnostic as this is not the point. */
5517 /* FIXME we're making this OK. */
5518 if (TREE_CODE (expr) == STRING_CST)
5520 if (complain & tf_error)
5521 error ("%qE is not a valid template argument for type %qT "
5522 "because string literals can never be used in this context",
5527 /* Add the ADDR_EXPR now for the benefit of
5528 value_dependent_expression_p. */
5529 if (TYPE_PTROBV_P (type)
5530 && TREE_CODE (TREE_TYPE (expr)) == ARRAY_TYPE)
5531 expr = decay_conversion (expr);
5533 /* If we are in a template, EXPR may be non-dependent, but still
5534 have a syntactic, rather than semantic, form. For example, EXPR
5535 might be a SCOPE_REF, rather than the VAR_DECL to which the
5536 SCOPE_REF refers. Preserving the qualifying scope is necessary
5537 so that access checking can be performed when the template is
5538 instantiated -- but here we need the resolved form so that we can
5539 convert the argument. */
5540 if (TYPE_REF_OBJ_P (type)
5541 && has_value_dependent_address (expr))
5542 /* If we want the address and it's value-dependent, don't fold. */;
5543 else if (!type_unknown_p (expr))
5544 expr = fold_non_dependent_expr_sfinae (expr, complain);
5545 if (error_operand_p (expr))
5546 return error_mark_node;
5547 expr_type = TREE_TYPE (expr);
5548 if (TREE_CODE (type) == REFERENCE_TYPE)
5549 expr = mark_lvalue_use (expr);
5551 expr = mark_rvalue_use (expr);
5553 /* HACK: Due to double coercion, we can get a
5554 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5555 which is the tree that we built on the first call (see
5556 below when coercing to reference to object or to reference to
5557 function). We just strip everything and get to the arg.
5558 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5560 if (TYPE_REF_OBJ_P (type) || TYPE_REFFN_P (type))
5562 tree probe_type, probe = expr;
5563 if (REFERENCE_REF_P (probe))
5564 probe = TREE_OPERAND (probe, 0);
5565 probe_type = TREE_TYPE (probe);
5566 if (TREE_CODE (probe) == NOP_EXPR)
5568 /* ??? Maybe we could use convert_from_reference here, but we
5569 would need to relax its constraints because the NOP_EXPR
5570 could actually change the type to something more cv-qualified,
5571 and this is not folded by convert_from_reference. */
5572 tree addr = TREE_OPERAND (probe, 0);
5573 gcc_assert (TREE_CODE (probe_type) == REFERENCE_TYPE);
5574 gcc_assert (TREE_CODE (addr) == ADDR_EXPR);
5575 gcc_assert (TREE_CODE (TREE_TYPE (addr)) == POINTER_TYPE);
5576 gcc_assert (same_type_ignoring_top_level_qualifiers_p
5577 (TREE_TYPE (probe_type),
5578 TREE_TYPE (TREE_TYPE (addr))));
5580 expr = TREE_OPERAND (addr, 0);
5581 expr_type = TREE_TYPE (expr);
5585 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5586 parameter is a pointer to object, through decay and
5587 qualification conversion. Let's strip everything. */
5588 else if (TREE_CODE (expr) == NOP_EXPR && TYPE_PTROBV_P (type))
5591 gcc_assert (TREE_CODE (expr) == ADDR_EXPR);
5592 gcc_assert (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE);
5593 /* Skip the ADDR_EXPR only if it is part of the decay for
5594 an array. Otherwise, it is part of the original argument
5595 in the source code. */
5596 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == ARRAY_TYPE)
5597 expr = TREE_OPERAND (expr, 0);
5598 expr_type = TREE_TYPE (expr);
5601 /* [temp.arg.nontype]/5, bullet 1
5603 For a non-type template-parameter of integral or enumeration type,
5604 integral promotions (_conv.prom_) and integral conversions
5605 (_conv.integral_) are applied. */
5606 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
5608 tree t = build_integral_nontype_arg_conv (type, expr, complain);
5609 t = maybe_constant_value (t);
5610 if (t != error_mark_node)
5613 if (!same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (expr)))
5614 return error_mark_node;
5616 /* Notice that there are constant expressions like '4 % 0' which
5617 do not fold into integer constants. */
5618 if (TREE_CODE (expr) != INTEGER_CST)
5620 if (complain & tf_error)
5622 int errs = errorcount, warns = warningcount;
5623 expr = cxx_constant_value (expr);
5624 if (errorcount > errs || warningcount > warns)
5625 inform (EXPR_LOC_OR_HERE (expr),
5626 "in template argument for type %qT ", type);
5627 if (expr == error_mark_node)
5629 /* else cxx_constant_value complained but gave us
5630 a real constant, so go ahead. */
5631 gcc_assert (TREE_CODE (expr) == INTEGER_CST);
5637 /* [temp.arg.nontype]/5, bullet 2
5639 For a non-type template-parameter of type pointer to object,
5640 qualification conversions (_conv.qual_) and the array-to-pointer
5641 conversion (_conv.array_) are applied. */
5642 else if (TYPE_PTROBV_P (type))
5644 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5646 A template-argument for a non-type, non-template template-parameter
5647 shall be one of: [...]
5649 -- the name of a non-type template-parameter;
5650 -- the address of an object or function with external linkage, [...]
5651 expressed as "& id-expression" where the & is optional if the name
5652 refers to a function or array, or if the corresponding
5653 template-parameter is a reference.
5655 Here, we do not care about functions, as they are invalid anyway
5656 for a parameter of type pointer-to-object. */
5658 if (DECL_P (expr) && DECL_TEMPLATE_PARM_P (expr))
5659 /* Non-type template parameters are OK. */
5661 else if (TREE_CODE (expr) != ADDR_EXPR
5662 && TREE_CODE (expr_type) != ARRAY_TYPE)
5664 if (TREE_CODE (expr) == VAR_DECL)
5666 error ("%qD is not a valid template argument "
5667 "because %qD is a variable, not the address of "
5672 /* Other values, like integer constants, might be valid
5673 non-type arguments of some other type. */
5674 return error_mark_node;
5680 decl = ((TREE_CODE (expr) == ADDR_EXPR)
5681 ? TREE_OPERAND (expr, 0) : expr);
5682 if (TREE_CODE (decl) != VAR_DECL)
5684 error ("%qE is not a valid template argument of type %qT "
5685 "because %qE is not a variable",
5689 else if (!DECL_EXTERNAL_LINKAGE_P (decl))
5691 error ("%qE is not a valid template argument of type %qT "
5692 "because %qD does not have external linkage",
5698 expr = decay_conversion (expr);
5699 if (expr == error_mark_node)
5700 return error_mark_node;
5702 expr = perform_qualification_conversions (type, expr);
5703 if (expr == error_mark_node)
5704 return error_mark_node;
5706 /* [temp.arg.nontype]/5, bullet 3
5708 For a non-type template-parameter of type reference to object, no
5709 conversions apply. The type referred to by the reference may be more
5710 cv-qualified than the (otherwise identical) type of the
5711 template-argument. The template-parameter is bound directly to the
5712 template-argument, which must be an lvalue. */
5713 else if (TYPE_REF_OBJ_P (type))
5715 if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type),
5717 return error_mark_node;
5719 if (!at_least_as_qualified_p (TREE_TYPE (type), expr_type))
5721 error ("%qE is not a valid template argument for type %qT "
5722 "because of conflicts in cv-qualification", expr, type);
5726 if (!real_lvalue_p (expr))
5728 error ("%qE is not a valid template argument for type %qT "
5729 "because it is not an lvalue", expr, type);
5733 /* [temp.arg.nontype]/1
5735 A template-argument for a non-type, non-template template-parameter
5736 shall be one of: [...]
5738 -- the address of an object or function with external linkage. */
5739 if (TREE_CODE (expr) == INDIRECT_REF
5740 && TYPE_REF_OBJ_P (TREE_TYPE (TREE_OPERAND (expr, 0))))
5742 expr = TREE_OPERAND (expr, 0);
5745 error ("%q#D is not a valid template argument for type %qT "
5746 "because a reference variable does not have a constant "
5747 "address", expr, type);
5754 error ("%qE is not a valid template argument for type %qT "
5755 "because it is not an object with external linkage",
5760 if (!DECL_EXTERNAL_LINKAGE_P (expr))
5762 error ("%qE is not a valid template argument for type %qT "
5763 "because object %qD has not external linkage",
5768 expr = build_nop (type, build_address (expr));
5770 /* [temp.arg.nontype]/5, bullet 4
5772 For a non-type template-parameter of type pointer to function, only
5773 the function-to-pointer conversion (_conv.func_) is applied. If the
5774 template-argument represents a set of overloaded functions (or a
5775 pointer to such), the matching function is selected from the set
5777 else if (TYPE_PTRFN_P (type))
5779 /* If the argument is a template-id, we might not have enough
5780 context information to decay the pointer. */
5781 if (!type_unknown_p (expr_type))
5783 expr = decay_conversion (expr);
5784 if (expr == error_mark_node)
5785 return error_mark_node;
5788 expr = convert_nontype_argument_function (type, expr);
5789 if (!expr || expr == error_mark_node)
5792 if (TREE_CODE (expr) != ADDR_EXPR)
5794 error ("%qE is not a valid template argument for type %qT", expr, type);
5795 error ("it must be the address of a function with external linkage");
5799 /* [temp.arg.nontype]/5, bullet 5
5801 For a non-type template-parameter of type reference to function, no
5802 conversions apply. If the template-argument represents a set of
5803 overloaded functions, the matching function is selected from the set
5805 else if (TYPE_REFFN_P (type))
5807 if (TREE_CODE (expr) == ADDR_EXPR)
5809 error ("%qE is not a valid template argument for type %qT "
5810 "because it is a pointer", expr, type);
5811 inform (input_location, "try using %qE instead", TREE_OPERAND (expr, 0));
5815 expr = convert_nontype_argument_function (TREE_TYPE (type), expr);
5816 if (!expr || expr == error_mark_node)
5819 expr = build_nop (type, build_address (expr));
5821 /* [temp.arg.nontype]/5, bullet 6
5823 For a non-type template-parameter of type pointer to member function,
5824 no conversions apply. If the template-argument represents a set of
5825 overloaded member functions, the matching member function is selected
5826 from the set (_over.over_). */
5827 else if (TYPE_PTRMEMFUNC_P (type))
5829 expr = instantiate_type (type, expr, tf_none);
5830 if (expr == error_mark_node)
5831 return error_mark_node;
5833 /* [temp.arg.nontype] bullet 1 says the pointer to member
5834 expression must be a pointer-to-member constant. */
5835 if (!check_valid_ptrmem_cst_expr (type, expr, complain))
5836 return error_mark_node;
5838 /* There is no way to disable standard conversions in
5839 resolve_address_of_overloaded_function (called by
5840 instantiate_type). It is possible that the call succeeded by
5841 converting &B::I to &D::I (where B is a base of D), so we need
5842 to reject this conversion here.
5844 Actually, even if there was a way to disable standard conversions,
5845 it would still be better to reject them here so that we can
5846 provide a superior diagnostic. */
5847 if (!same_type_p (TREE_TYPE (expr), type))
5849 error ("%qE is not a valid template argument for type %qT "
5850 "because it is of type %qT", expr, type,
5852 /* If we are just one standard conversion off, explain. */
5853 if (can_convert (type, TREE_TYPE (expr)))
5854 inform (input_location,
5855 "standard conversions are not allowed in this context");
5859 /* [temp.arg.nontype]/5, bullet 7
5861 For a non-type template-parameter of type pointer to data member,
5862 qualification conversions (_conv.qual_) are applied. */
5863 else if (TYPE_PTRMEM_P (type))
5865 /* [temp.arg.nontype] bullet 1 says the pointer to member
5866 expression must be a pointer-to-member constant. */
5867 if (!check_valid_ptrmem_cst_expr (type, expr, complain))
5868 return error_mark_node;
5870 expr = perform_qualification_conversions (type, expr);
5871 if (expr == error_mark_node)
5874 /* A template non-type parameter must be one of the above. */
5878 /* Sanity check: did we actually convert the argument to the
5880 gcc_assert (same_type_ignoring_top_level_qualifiers_p
5881 (type, TREE_TYPE (expr)));
5885 /* Subroutine of coerce_template_template_parms, which returns 1 if
5886 PARM_PARM and ARG_PARM match using the rule for the template
5887 parameters of template template parameters. Both PARM and ARG are
5888 template parameters; the rest of the arguments are the same as for
5889 coerce_template_template_parms.
5892 coerce_template_template_parm (tree parm,
5894 tsubst_flags_t complain,
5898 if (arg == NULL_TREE || arg == error_mark_node
5899 || parm == NULL_TREE || parm == error_mark_node)
5902 if (TREE_CODE (arg) != TREE_CODE (parm))
5905 switch (TREE_CODE (parm))
5908 /* We encounter instantiations of templates like
5909 template <template <template <class> class> class TT>
5912 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
5913 tree argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
5915 if (!coerce_template_template_parms
5916 (parmparm, argparm, complain, in_decl, outer_args))
5922 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (arg))
5923 && !TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
5924 /* Argument is a parameter pack but parameter is not. */
5929 /* The tsubst call is used to handle cases such as
5931 template <int> class C {};
5932 template <class T, template <T> class TT> class D {};
5935 i.e. the parameter list of TT depends on earlier parameters. */
5936 if (!uses_template_parms (TREE_TYPE (arg))
5938 (tsubst (TREE_TYPE (parm), outer_args, complain, in_decl),
5942 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (arg))
5943 && !TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
5944 /* Argument is a parameter pack but parameter is not. */
5957 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
5958 template template parameters. Both PARM_PARMS and ARG_PARMS are
5959 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
5962 Consider the example:
5963 template <class T> class A;
5964 template<template <class U> class TT> class B;
5966 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
5967 the parameters to A, and OUTER_ARGS contains A. */
5970 coerce_template_template_parms (tree parm_parms,
5972 tsubst_flags_t complain,
5976 int nparms, nargs, i;
5980 gcc_assert (TREE_CODE (parm_parms) == TREE_VEC);
5981 gcc_assert (TREE_CODE (arg_parms) == TREE_VEC);
5983 nparms = TREE_VEC_LENGTH (parm_parms);
5984 nargs = TREE_VEC_LENGTH (arg_parms);
5986 /* Determine whether we have a parameter pack at the end of the
5987 template template parameter's template parameter list. */
5988 if (TREE_VEC_ELT (parm_parms, nparms - 1) != error_mark_node)
5990 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, nparms - 1));
5992 if (parm == error_mark_node)
5995 switch (TREE_CODE (parm))
5999 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
6004 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
6014 && !(variadic_p && nargs >= nparms - 1))
6017 /* Check all of the template parameters except the parameter pack at
6018 the end (if any). */
6019 for (i = 0; i < nparms - variadic_p; ++i)
6021 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node
6022 || TREE_VEC_ELT (arg_parms, i) == error_mark_node)
6025 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
6026 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
6028 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
6036 /* Check each of the template parameters in the template
6037 argument against the template parameter pack at the end of
6038 the template template parameter. */
6039 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node)
6042 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
6044 for (; i < nargs; ++i)
6046 if (TREE_VEC_ELT (arg_parms, i) == error_mark_node)
6049 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
6051 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
6060 /* Verifies that the deduced template arguments (in TARGS) for the
6061 template template parameters (in TPARMS) represent valid bindings,
6062 by comparing the template parameter list of each template argument
6063 to the template parameter list of its corresponding template
6064 template parameter, in accordance with DR150. This
6065 routine can only be called after all template arguments have been
6066 deduced. It will return TRUE if all of the template template
6067 parameter bindings are okay, FALSE otherwise. */
6069 template_template_parm_bindings_ok_p (tree tparms, tree targs)
6071 int i, ntparms = TREE_VEC_LENGTH (tparms);
6074 /* We're dealing with template parms in this process. */
6075 ++processing_template_decl;
6077 targs = INNERMOST_TEMPLATE_ARGS (targs);
6079 for (i = 0; i < ntparms; ++i)
6081 tree tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
6082 tree targ = TREE_VEC_ELT (targs, i);
6084 if (TREE_CODE (tparm) == TEMPLATE_DECL && targ)
6086 tree packed_args = NULL_TREE;
6089 if (ARGUMENT_PACK_P (targ))
6091 /* Look inside the argument pack. */
6092 packed_args = ARGUMENT_PACK_ARGS (targ);
6093 len = TREE_VEC_LENGTH (packed_args);
6096 for (idx = 0; idx < len; ++idx)
6098 tree targ_parms = NULL_TREE;
6101 /* Extract the next argument from the argument
6103 targ = TREE_VEC_ELT (packed_args, idx);
6105 if (PACK_EXPANSION_P (targ))
6106 /* Look at the pattern of the pack expansion. */
6107 targ = PACK_EXPANSION_PATTERN (targ);
6109 /* Extract the template parameters from the template
6111 if (TREE_CODE (targ) == TEMPLATE_DECL)
6112 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (targ);
6113 else if (TREE_CODE (targ) == TEMPLATE_TEMPLATE_PARM)
6114 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (TYPE_NAME (targ));
6116 /* Verify that we can coerce the template template
6117 parameters from the template argument to the template
6118 parameter. This requires an exact match. */
6120 && !coerce_template_template_parms
6121 (DECL_INNERMOST_TEMPLATE_PARMS (tparm),
6136 --processing_template_decl;
6140 /* Since type attributes aren't mangled, we need to strip them from
6141 template type arguments. */
6144 canonicalize_type_argument (tree arg, tsubst_flags_t complain)
6147 if (!arg || arg == error_mark_node || arg == TYPE_CANONICAL (arg))
6149 mv = TYPE_MAIN_VARIANT (arg);
6150 arg = strip_typedefs (arg);
6151 if (TYPE_ALIGN (arg) != TYPE_ALIGN (mv)
6152 || TYPE_ATTRIBUTES (arg) != TYPE_ATTRIBUTES (mv))
6154 if (complain & tf_warning)
6155 warning (0, "ignoring attributes on template argument %qT", arg);
6156 arg = build_aligned_type (arg, TYPE_ALIGN (mv));
6157 arg = cp_build_type_attribute_variant (arg, TYPE_ATTRIBUTES (mv));
6162 /* Convert the indicated template ARG as necessary to match the
6163 indicated template PARM. Returns the converted ARG, or
6164 error_mark_node if the conversion was unsuccessful. Error and
6165 warning messages are issued under control of COMPLAIN. This
6166 conversion is for the Ith parameter in the parameter list. ARGS is
6167 the full set of template arguments deduced so far. */
6170 convert_template_argument (tree parm,
6173 tsubst_flags_t complain,
6179 int is_type, requires_type, is_tmpl_type, requires_tmpl_type;
6181 if (TREE_CODE (arg) == TREE_LIST
6182 && TREE_CODE (TREE_VALUE (arg)) == OFFSET_REF)
6184 /* The template argument was the name of some
6185 member function. That's usually
6186 invalid, but static members are OK. In any
6187 case, grab the underlying fields/functions
6188 and issue an error later if required. */
6189 orig_arg = TREE_VALUE (arg);
6190 TREE_TYPE (arg) = unknown_type_node;
6195 requires_tmpl_type = TREE_CODE (parm) == TEMPLATE_DECL;
6196 requires_type = (TREE_CODE (parm) == TYPE_DECL
6197 || requires_tmpl_type);
6199 /* When determining whether an argument pack expansion is a template,
6200 look at the pattern. */
6201 if (TREE_CODE (arg) == TYPE_PACK_EXPANSION)
6202 arg = PACK_EXPANSION_PATTERN (arg);
6204 /* Deal with an injected-class-name used as a template template arg. */
6205 if (requires_tmpl_type && CLASS_TYPE_P (arg))
6207 tree t = maybe_get_template_decl_from_type_decl (TYPE_NAME (arg));
6208 if (TREE_CODE (t) == TEMPLATE_DECL)
6210 if (cxx_dialect >= cxx0x)
6211 /* OK under DR 1004. */;
6212 else if (complain & tf_warning_or_error)
6213 pedwarn (input_location, OPT_pedantic, "injected-class-name %qD"
6214 " used as template template argument", TYPE_NAME (arg));
6215 else if (flag_pedantic_errors)
6223 ((TREE_CODE (arg) == TEMPLATE_DECL
6224 && TREE_CODE (DECL_TEMPLATE_RESULT (arg)) == TYPE_DECL)
6225 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
6226 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE);
6229 && (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
6230 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE))
6231 arg = TYPE_STUB_DECL (arg);
6233 is_type = TYPE_P (arg) || is_tmpl_type;
6235 if (requires_type && ! is_type && TREE_CODE (arg) == SCOPE_REF
6236 && TREE_CODE (TREE_OPERAND (arg, 0)) == TEMPLATE_TYPE_PARM)
6238 permerror (input_location, "to refer to a type member of a template parameter, "
6239 "use %<typename %E%>", orig_arg);
6241 orig_arg = make_typename_type (TREE_OPERAND (arg, 0),
6242 TREE_OPERAND (arg, 1),
6244 complain & tf_error);
6248 if (is_type != requires_type)
6252 if (complain & tf_error)
6254 error ("type/value mismatch at argument %d in template "
6255 "parameter list for %qD",
6258 error (" expected a constant of type %qT, got %qT",
6260 (DECL_P (arg) ? DECL_NAME (arg) : orig_arg));
6261 else if (requires_tmpl_type)
6262 error (" expected a class template, got %qE", orig_arg);
6264 error (" expected a type, got %qE", orig_arg);
6267 return error_mark_node;
6269 if (is_tmpl_type ^ requires_tmpl_type)
6271 if (in_decl && (complain & tf_error))
6273 error ("type/value mismatch at argument %d in template "
6274 "parameter list for %qD",
6277 error (" expected a type, got %qT", DECL_NAME (arg));
6279 error (" expected a class template, got %qT", orig_arg);
6281 return error_mark_node;
6286 if (requires_tmpl_type)
6288 if (TREE_CODE (TREE_TYPE (arg)) == UNBOUND_CLASS_TEMPLATE)
6289 /* The number of argument required is not known yet.
6290 Just accept it for now. */
6291 val = TREE_TYPE (arg);
6294 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
6297 argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
6299 if (coerce_template_template_parms (parmparm, argparm,
6305 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6307 if (val != error_mark_node)
6309 if (DECL_TEMPLATE_TEMPLATE_PARM_P (val))
6310 val = TREE_TYPE (val);
6311 if (TREE_CODE (orig_arg) == TYPE_PACK_EXPANSION)
6312 val = make_pack_expansion (val);
6317 if (in_decl && (complain & tf_error))
6319 error ("type/value mismatch at argument %d in "
6320 "template parameter list for %qD",
6322 error (" expected a template of type %qD, got %qT",
6326 val = error_mark_node;
6332 /* We only form one instance of each template specialization.
6333 Therefore, if we use a non-canonical variant (i.e., a
6334 typedef), any future messages referring to the type will use
6335 the typedef, which is confusing if those future uses do not
6336 themselves also use the typedef. */
6338 val = canonicalize_type_argument (val, complain);
6342 tree t = tsubst (TREE_TYPE (parm), args, complain, in_decl);
6344 if (invalid_nontype_parm_type_p (t, complain))
6345 return error_mark_node;
6347 if (template_parameter_pack_p (parm) && ARGUMENT_PACK_P (orig_arg))
6349 if (same_type_p (t, TREE_TYPE (orig_arg)))
6353 /* Not sure if this is reachable, but it doesn't hurt
6355 error ("type mismatch in nontype parameter pack");
6356 val = error_mark_node;
6359 else if (!uses_template_parms (orig_arg) && !uses_template_parms (t))
6360 /* We used to call digest_init here. However, digest_init
6361 will report errors, which we don't want when complain
6362 is zero. More importantly, digest_init will try too
6363 hard to convert things: for example, `0' should not be
6364 converted to pointer type at this point according to
6365 the standard. Accepting this is not merely an
6366 extension, since deciding whether or not these
6367 conversions can occur is part of determining which
6368 function template to call, or whether a given explicit
6369 argument specification is valid. */
6370 val = convert_nontype_argument (t, orig_arg, complain);
6374 if (val == NULL_TREE)
6375 val = error_mark_node;
6376 else if (val == error_mark_node && (complain & tf_error))
6377 error ("could not convert template argument %qE to %qT", orig_arg, t);
6379 if (TREE_CODE (val) == SCOPE_REF)
6381 /* Strip typedefs from the SCOPE_REF. */
6382 tree type = canonicalize_type_argument (TREE_TYPE (val), complain);
6383 tree scope = canonicalize_type_argument (TREE_OPERAND (val, 0),
6385 val = build_qualified_name (type, scope, TREE_OPERAND (val, 1),
6386 QUALIFIED_NAME_IS_TEMPLATE (val));
6393 /* Coerces the remaining template arguments in INNER_ARGS (from
6394 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6395 Returns the coerced argument pack. PARM_IDX is the position of this
6396 parameter in the template parameter list. ARGS is the original
6397 template argument list. */
6399 coerce_template_parameter_pack (tree parms,
6407 tsubst_flags_t complain)
6409 tree parm = TREE_VEC_ELT (parms, parm_idx);
6410 int nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
6413 tree packed_types = NULL_TREE;
6415 if (arg_idx > nargs)
6418 packed_args = make_tree_vec (nargs - arg_idx);
6420 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL
6421 && uses_parameter_packs (TREE_TYPE (TREE_VALUE (parm))))
6423 /* When the template parameter is a non-type template
6424 parameter pack whose type uses parameter packs, we need
6425 to look at each of the template arguments
6426 separately. Build a vector of the types for these
6427 non-type template parameters in PACKED_TYPES. */
6429 = make_pack_expansion (TREE_TYPE (TREE_VALUE (parm)));
6430 packed_types = tsubst_pack_expansion (expansion, args,
6433 if (packed_types == error_mark_node)
6434 return error_mark_node;
6436 /* Check that we have the right number of arguments. */
6438 && !PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx))
6439 && nargs - arg_idx != TREE_VEC_LENGTH (packed_types))
6442 = TREE_VEC_LENGTH (parms) - 1 + TREE_VEC_LENGTH (packed_types);
6443 error ("wrong number of template arguments (%d, should be %d)",
6444 nargs, needed_parms);
6445 return error_mark_node;
6448 /* If we aren't able to check the actual arguments now
6449 (because they haven't been expanded yet), we can at least
6450 verify that all of the types used for the non-type
6451 template parameter pack are, in fact, valid for non-type
6452 template parameters. */
6454 && PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx)))
6456 int j, len = TREE_VEC_LENGTH (packed_types);
6457 for (j = 0; j < len; ++j)
6459 tree t = TREE_VEC_ELT (packed_types, j);
6460 if (invalid_nontype_parm_type_p (t, complain))
6461 return error_mark_node;
6466 /* Convert the remaining arguments, which will be a part of the
6467 parameter pack "parm". */
6468 for (; arg_idx < nargs; ++arg_idx)
6470 tree arg = TREE_VEC_ELT (inner_args, arg_idx);
6471 tree actual_parm = TREE_VALUE (parm);
6473 if (packed_types && !PACK_EXPANSION_P (arg))
6475 /* When we have a vector of types (corresponding to the
6476 non-type template parameter pack that uses parameter
6477 packs in its type, as mention above), and the
6478 argument is not an expansion (which expands to a
6479 currently unknown number of arguments), clone the
6480 parm and give it the next type in PACKED_TYPES. */
6481 actual_parm = copy_node (actual_parm);
6482 TREE_TYPE (actual_parm) =
6483 TREE_VEC_ELT (packed_types, arg_idx - parm_idx);
6486 if (arg != error_mark_node)
6487 arg = convert_template_argument (actual_parm,
6488 arg, new_args, complain, parm_idx,
6490 if (arg == error_mark_node)
6492 TREE_VEC_ELT (packed_args, arg_idx - parm_idx) = arg;
6495 if (TREE_CODE (TREE_VALUE (parm)) == TYPE_DECL
6496 || TREE_CODE (TREE_VALUE (parm)) == TEMPLATE_DECL)
6497 argument_pack = cxx_make_type (TYPE_ARGUMENT_PACK);
6500 argument_pack = make_node (NONTYPE_ARGUMENT_PACK);
6501 TREE_TYPE (argument_pack)
6502 = tsubst (TREE_TYPE (TREE_VALUE (parm)), new_args, complain, in_decl);
6503 TREE_CONSTANT (argument_pack) = 1;
6506 SET_ARGUMENT_PACK_ARGS (argument_pack, packed_args);
6507 #ifdef ENABLE_CHECKING
6508 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (packed_args,
6509 TREE_VEC_LENGTH (packed_args));
6511 return argument_pack;
6514 /* Convert all template arguments to their appropriate types, and
6515 return a vector containing the innermost resulting template
6516 arguments. If any error occurs, return error_mark_node. Error and
6517 warning messages are issued under control of COMPLAIN.
6519 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6520 for arguments not specified in ARGS. Otherwise, if
6521 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6522 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6523 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6527 coerce_template_parms (tree parms,
6530 tsubst_flags_t complain,
6531 bool require_all_args,
6532 bool use_default_args)
6534 int nparms, nargs, parm_idx, arg_idx, lost = 0;
6537 tree new_inner_args;
6538 int saved_unevaluated_operand;
6539 int saved_inhibit_evaluation_warnings;
6541 /* When used as a boolean value, indicates whether this is a
6542 variadic template parameter list. Since it's an int, we can also
6543 subtract it from nparms to get the number of non-variadic
6546 int post_variadic_parms = 0;
6548 if (args == error_mark_node)
6549 return error_mark_node;
6551 nparms = TREE_VEC_LENGTH (parms);
6553 /* Determine if there are any parameter packs. */
6554 for (parm_idx = 0; parm_idx < nparms; ++parm_idx)
6556 tree tparm = TREE_VALUE (TREE_VEC_ELT (parms, parm_idx));
6558 ++post_variadic_parms;
6559 if (template_parameter_pack_p (tparm))
6563 inner_args = INNERMOST_TEMPLATE_ARGS (args);
6564 /* If there are no parameters that follow a parameter pack, we need to
6565 expand any argument packs so that we can deduce a parameter pack from
6566 some non-packed args followed by an argument pack, as in variadic85.C.
6567 If there are such parameters, we need to leave argument packs intact
6568 so the arguments are assigned properly. This can happen when dealing
6569 with a nested class inside a partial specialization of a class
6570 template, as in variadic92.C, or when deducing a template parameter pack
6571 from a sub-declarator, as in variadic114.C. */
6572 if (!post_variadic_parms)
6573 inner_args = expand_template_argument_pack (inner_args);
6575 nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
6576 if ((nargs > nparms && !variadic_p)
6577 || (nargs < nparms - variadic_p
6579 && (!use_default_args
6580 || (TREE_VEC_ELT (parms, nargs) != error_mark_node
6581 && !TREE_PURPOSE (TREE_VEC_ELT (parms, nargs))))))
6583 if (complain & tf_error)
6587 nparms -= variadic_p;
6588 error ("wrong number of template arguments "
6589 "(%d, should be %d or more)", nargs, nparms);
6592 error ("wrong number of template arguments "
6593 "(%d, should be %d)", nargs, nparms);
6596 error ("provided for %q+D", in_decl);
6599 return error_mark_node;
6602 /* We need to evaluate the template arguments, even though this
6603 template-id may be nested within a "sizeof". */
6604 saved_unevaluated_operand = cp_unevaluated_operand;
6605 cp_unevaluated_operand = 0;
6606 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
6607 c_inhibit_evaluation_warnings = 0;
6608 new_inner_args = make_tree_vec (nparms);
6609 new_args = add_outermost_template_args (args, new_inner_args);
6610 for (parm_idx = 0, arg_idx = 0; parm_idx < nparms; parm_idx++, arg_idx++)
6615 /* Get the Ith template parameter. */
6616 parm = TREE_VEC_ELT (parms, parm_idx);
6618 if (parm == error_mark_node)
6620 TREE_VEC_ELT (new_inner_args, arg_idx) = error_mark_node;
6624 /* Calculate the next argument. */
6625 if (arg_idx < nargs)
6626 arg = TREE_VEC_ELT (inner_args, arg_idx);
6630 if (template_parameter_pack_p (TREE_VALUE (parm))
6631 && !(arg && ARGUMENT_PACK_P (arg)))
6633 /* All remaining arguments will be placed in the
6634 template parameter pack PARM. */
6635 arg = coerce_template_parameter_pack (parms, parm_idx, args,
6636 inner_args, arg_idx,
6640 /* Store this argument. */
6641 if (arg == error_mark_node)
6643 TREE_VEC_ELT (new_inner_args, parm_idx) = arg;
6645 /* We are done with all of the arguments. */
6652 if (PACK_EXPANSION_P (arg))
6654 if (complain & tf_error)
6656 /* FIXME this restriction was removed by N2555; see
6658 /* If ARG is a pack expansion, but PARM is not a
6659 template parameter pack (if it were, we would have
6660 handled it above), we're trying to expand into a
6661 fixed-length argument list. */
6662 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
6663 sorry ("cannot expand %<%E%> into a fixed-length "
6664 "argument list", arg);
6666 sorry ("cannot expand %<%T%> into a fixed-length "
6667 "argument list", arg);
6672 else if (require_all_args)
6674 /* There must be a default arg in this case. */
6675 arg = tsubst_template_arg (TREE_PURPOSE (parm), new_args,
6677 /* The position of the first default template argument,
6678 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6680 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args))
6681 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args, arg_idx);
6686 if (arg == error_mark_node)
6688 if (complain & tf_error)
6689 error ("template argument %d is invalid", arg_idx + 1);
6692 /* This only occurs if there was an error in the template
6693 parameter list itself (which we would already have
6694 reported) that we are trying to recover from, e.g., a class
6695 template with a parameter list such as
6696 template<typename..., typename>. */
6699 arg = convert_template_argument (TREE_VALUE (parm),
6700 arg, new_args, complain,
6703 if (arg == error_mark_node)
6705 TREE_VEC_ELT (new_inner_args, arg_idx) = arg;
6707 cp_unevaluated_operand = saved_unevaluated_operand;
6708 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
6711 return error_mark_node;
6713 #ifdef ENABLE_CHECKING
6714 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args))
6715 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args,
6716 TREE_VEC_LENGTH (new_inner_args));
6719 return new_inner_args;
6722 /* Returns 1 if template args OT and NT are equivalent. */
6725 template_args_equal (tree ot, tree nt)
6729 if (nt == NULL_TREE || ot == NULL_TREE)
6732 if (TREE_CODE (nt) == TREE_VEC)
6733 /* For member templates */
6734 return TREE_CODE (ot) == TREE_VEC && comp_template_args (ot, nt);
6735 else if (PACK_EXPANSION_P (ot))
6736 return PACK_EXPANSION_P (nt)
6737 && template_args_equal (PACK_EXPANSION_PATTERN (ot),
6738 PACK_EXPANSION_PATTERN (nt));
6739 else if (ARGUMENT_PACK_P (ot))
6744 if (!ARGUMENT_PACK_P (nt))
6747 opack = ARGUMENT_PACK_ARGS (ot);
6748 npack = ARGUMENT_PACK_ARGS (nt);
6749 len = TREE_VEC_LENGTH (opack);
6750 if (TREE_VEC_LENGTH (npack) != len)
6752 for (i = 0; i < len; ++i)
6753 if (!template_args_equal (TREE_VEC_ELT (opack, i),
6754 TREE_VEC_ELT (npack, i)))
6758 else if (ot && TREE_CODE (ot) == ARGUMENT_PACK_SELECT)
6760 /* We get here probably because we are in the middle of substituting
6761 into the pattern of a pack expansion. In that case the
6762 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
6763 interested in. So we want to use the initial pack argument for
6765 ot = ARGUMENT_PACK_SELECT_FROM_PACK (ot);
6766 if (nt && TREE_CODE (nt) == ARGUMENT_PACK_SELECT)
6767 nt = ARGUMENT_PACK_SELECT_FROM_PACK (nt);
6768 return template_args_equal (ot, nt);
6770 else if (TYPE_P (nt))
6771 return TYPE_P (ot) && same_type_p (ot, nt);
6772 else if (TREE_CODE (ot) == TREE_VEC || TYPE_P (ot))
6775 return cp_tree_equal (ot, nt);
6778 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
6779 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
6780 NEWARG_PTR with the offending arguments if they are non-NULL. */
6783 comp_template_args_with_info (tree oldargs, tree newargs,
6784 tree *oldarg_ptr, tree *newarg_ptr)
6788 if (TREE_VEC_LENGTH (oldargs) != TREE_VEC_LENGTH (newargs))
6791 for (i = 0; i < TREE_VEC_LENGTH (oldargs); ++i)
6793 tree nt = TREE_VEC_ELT (newargs, i);
6794 tree ot = TREE_VEC_ELT (oldargs, i);
6796 if (! template_args_equal (ot, nt))
6798 if (oldarg_ptr != NULL)
6800 if (newarg_ptr != NULL)
6808 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
6809 of template arguments. Returns 0 otherwise. */
6812 comp_template_args (tree oldargs, tree newargs)
6814 return comp_template_args_with_info (oldargs, newargs, NULL, NULL);
6818 add_pending_template (tree d)
6820 tree ti = (TYPE_P (d)
6821 ? CLASSTYPE_TEMPLATE_INFO (d)
6822 : DECL_TEMPLATE_INFO (d));
6823 struct pending_template *pt;
6826 if (TI_PENDING_TEMPLATE_FLAG (ti))
6829 /* We are called both from instantiate_decl, where we've already had a
6830 tinst_level pushed, and instantiate_template, where we haven't.
6832 level = !current_tinst_level || current_tinst_level->decl != d;
6835 push_tinst_level (d);
6837 pt = ggc_alloc_pending_template ();
6839 pt->tinst = current_tinst_level;
6840 if (last_pending_template)
6841 last_pending_template->next = pt;
6843 pending_templates = pt;
6845 last_pending_template = pt;
6847 TI_PENDING_TEMPLATE_FLAG (ti) = 1;
6854 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
6855 ARGLIST. Valid choices for FNS are given in the cp-tree.def
6856 documentation for TEMPLATE_ID_EXPR. */
6859 lookup_template_function (tree fns, tree arglist)
6863 if (fns == error_mark_node || arglist == error_mark_node)
6864 return error_mark_node;
6866 gcc_assert (!arglist || TREE_CODE (arglist) == TREE_VEC);
6868 if (!is_overloaded_fn (fns) && TREE_CODE (fns) != IDENTIFIER_NODE)
6870 error ("%q#D is not a function template", fns);
6871 return error_mark_node;
6874 if (BASELINK_P (fns))
6876 BASELINK_FUNCTIONS (fns) = build2 (TEMPLATE_ID_EXPR,
6878 BASELINK_FUNCTIONS (fns),
6883 type = TREE_TYPE (fns);
6884 if (TREE_CODE (fns) == OVERLOAD || !type)
6885 type = unknown_type_node;
6887 return build2 (TEMPLATE_ID_EXPR, type, fns, arglist);
6890 /* Within the scope of a template class S<T>, the name S gets bound
6891 (in build_self_reference) to a TYPE_DECL for the class, not a
6892 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
6893 or one of its enclosing classes, and that type is a template,
6894 return the associated TEMPLATE_DECL. Otherwise, the original
6897 Also handle the case when DECL is a TREE_LIST of ambiguous
6898 injected-class-names from different bases. */
6901 maybe_get_template_decl_from_type_decl (tree decl)
6903 if (decl == NULL_TREE)
6906 /* DR 176: A lookup that finds an injected-class-name (10.2
6907 [class.member.lookup]) can result in an ambiguity in certain cases
6908 (for example, if it is found in more than one base class). If all of
6909 the injected-class-names that are found refer to specializations of
6910 the same class template, and if the name is followed by a
6911 template-argument-list, the reference refers to the class template
6912 itself and not a specialization thereof, and is not ambiguous. */
6913 if (TREE_CODE (decl) == TREE_LIST)
6915 tree t, tmpl = NULL_TREE;
6916 for (t = decl; t; t = TREE_CHAIN (t))
6918 tree elt = maybe_get_template_decl_from_type_decl (TREE_VALUE (t));
6921 else if (tmpl != elt)
6924 if (tmpl && t == NULL_TREE)
6930 return (decl != NULL_TREE
6931 && DECL_SELF_REFERENCE_P (decl)
6932 && CLASSTYPE_TEMPLATE_INFO (TREE_TYPE (decl)))
6933 ? CLASSTYPE_TI_TEMPLATE (TREE_TYPE (decl)) : decl;
6936 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
6937 parameters, find the desired type.
6939 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
6941 IN_DECL, if non-NULL, is the template declaration we are trying to
6944 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
6945 the class we are looking up.
6947 Issue error and warning messages under control of COMPLAIN.
6949 If the template class is really a local class in a template
6950 function, then the FUNCTION_CONTEXT is the function in which it is
6953 ??? Note that this function is currently called *twice* for each
6954 template-id: the first time from the parser, while creating the
6955 incomplete type (finish_template_type), and the second type during the
6956 real instantiation (instantiate_template_class). This is surely something
6957 that we want to avoid. It also causes some problems with argument
6958 coercion (see convert_nontype_argument for more information on this). */
6961 lookup_template_class_1 (tree d1, tree arglist, tree in_decl, tree context,
6962 int entering_scope, tsubst_flags_t complain)
6964 tree templ = NULL_TREE, parmlist;
6971 if (TREE_CODE (d1) == IDENTIFIER_NODE)
6973 tree value = innermost_non_namespace_value (d1);
6974 if (value && DECL_TEMPLATE_TEMPLATE_PARM_P (value))
6979 push_decl_namespace (context);
6980 templ = lookup_name (d1);
6981 templ = maybe_get_template_decl_from_type_decl (templ);
6983 pop_decl_namespace ();
6986 context = DECL_CONTEXT (templ);
6988 else if (TREE_CODE (d1) == TYPE_DECL && MAYBE_CLASS_TYPE_P (TREE_TYPE (d1)))
6990 tree type = TREE_TYPE (d1);
6992 /* If we are declaring a constructor, say A<T>::A<T>, we will get
6993 an implicit typename for the second A. Deal with it. */
6994 if (TREE_CODE (type) == TYPENAME_TYPE && TREE_TYPE (type))
6995 type = TREE_TYPE (type);
6997 if (CLASSTYPE_TEMPLATE_INFO (type))
6999 templ = CLASSTYPE_TI_TEMPLATE (type);
7000 d1 = DECL_NAME (templ);
7003 else if (TREE_CODE (d1) == ENUMERAL_TYPE
7004 || (TYPE_P (d1) && MAYBE_CLASS_TYPE_P (d1)))
7006 templ = TYPE_TI_TEMPLATE (d1);
7007 d1 = DECL_NAME (templ);
7009 else if (TREE_CODE (d1) == TEMPLATE_DECL
7010 && DECL_TEMPLATE_RESULT (d1)
7011 && TREE_CODE (DECL_TEMPLATE_RESULT (d1)) == TYPE_DECL)
7014 d1 = DECL_NAME (templ);
7015 context = DECL_CONTEXT (templ);
7018 /* Issue an error message if we didn't find a template. */
7021 if (complain & tf_error)
7022 error ("%qT is not a template", d1);
7023 return error_mark_node;
7026 if (TREE_CODE (templ) != TEMPLATE_DECL
7027 /* Make sure it's a user visible template, if it was named by
7029 || ((complain & tf_user) && !DECL_TEMPLATE_PARM_P (templ)
7030 && !PRIMARY_TEMPLATE_P (templ)))
7032 if (complain & tf_error)
7034 error ("non-template type %qT used as a template", d1);
7036 error ("for template declaration %q+D", in_decl);
7038 return error_mark_node;
7041 complain &= ~tf_user;
7043 if (DECL_TEMPLATE_TEMPLATE_PARM_P (templ))
7045 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
7046 template arguments */
7052 parmlist = DECL_INNERMOST_TEMPLATE_PARMS (templ);
7054 /* Consider an example where a template template parameter declared as
7056 template <class T, class U = std::allocator<T> > class TT
7058 The template parameter level of T and U are one level larger than
7059 of TT. To proper process the default argument of U, say when an
7060 instantiation `TT<int>' is seen, we need to build the full
7061 arguments containing {int} as the innermost level. Outer levels,
7062 available when not appearing as default template argument, can be
7063 obtained from the arguments of the enclosing template.
7065 Suppose that TT is later substituted with std::vector. The above
7066 instantiation is `TT<int, std::allocator<T> >' with TT at
7067 level 1, and T at level 2, while the template arguments at level 1
7068 becomes {std::vector} and the inner level 2 is {int}. */
7070 outer = DECL_CONTEXT (templ);
7072 outer = TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (outer)));
7073 else if (current_template_parms)
7074 /* This is an argument of the current template, so we haven't set
7075 DECL_CONTEXT yet. */
7076 outer = current_template_args ();
7079 arglist = add_to_template_args (outer, arglist);
7081 arglist2 = coerce_template_parms (parmlist, arglist, templ,
7083 /*require_all_args=*/true,
7084 /*use_default_args=*/true);
7085 if (arglist2 == error_mark_node
7086 || (!uses_template_parms (arglist2)
7087 && check_instantiated_args (templ, arglist2, complain)))
7088 return error_mark_node;
7090 parm = bind_template_template_parm (TREE_TYPE (templ), arglist2);
7095 tree template_type = TREE_TYPE (templ);
7098 tree found = NULL_TREE;
7101 int is_dependent_type;
7102 int use_partial_inst_tmpl = false;
7104 gen_tmpl = most_general_template (templ);
7105 parmlist = DECL_TEMPLATE_PARMS (gen_tmpl);
7106 parm_depth = TMPL_PARMS_DEPTH (parmlist);
7107 arg_depth = TMPL_ARGS_DEPTH (arglist);
7109 if (arg_depth == 1 && parm_depth > 1)
7111 /* We've been given an incomplete set of template arguments.
7114 template <class T> struct S1 {
7115 template <class U> struct S2 {};
7116 template <class U> struct S2<U*> {};
7119 we will be called with an ARGLIST of `U*', but the
7120 TEMPLATE will be `template <class T> template
7121 <class U> struct S1<T>::S2'. We must fill in the missing
7124 = add_outermost_template_args (TYPE_TI_ARGS (TREE_TYPE (templ)),
7126 arg_depth = TMPL_ARGS_DEPTH (arglist);
7129 /* Now we should have enough arguments. */
7130 gcc_assert (parm_depth == arg_depth);
7132 /* From here on, we're only interested in the most general
7135 /* Calculate the BOUND_ARGS. These will be the args that are
7136 actually tsubst'd into the definition to create the
7140 /* We have multiple levels of arguments to coerce, at once. */
7142 int saved_depth = TMPL_ARGS_DEPTH (arglist);
7144 tree bound_args = make_tree_vec (parm_depth);
7146 for (i = saved_depth,
7147 t = DECL_TEMPLATE_PARMS (gen_tmpl);
7148 i > 0 && t != NULL_TREE;
7149 --i, t = TREE_CHAIN (t))
7152 if (i == saved_depth)
7153 a = coerce_template_parms (TREE_VALUE (t),
7156 /*require_all_args=*/true,
7157 /*use_default_args=*/true);
7159 /* Outer levels should have already been coerced. */
7160 a = TMPL_ARGS_LEVEL (arglist, i);
7162 /* Don't process further if one of the levels fails. */
7163 if (a == error_mark_node)
7165 /* Restore the ARGLIST to its full size. */
7166 TREE_VEC_LENGTH (arglist) = saved_depth;
7167 return error_mark_node;
7170 SET_TMPL_ARGS_LEVEL (bound_args, i, a);
7172 /* We temporarily reduce the length of the ARGLIST so
7173 that coerce_template_parms will see only the arguments
7174 corresponding to the template parameters it is
7176 TREE_VEC_LENGTH (arglist)--;
7179 /* Restore the ARGLIST to its full size. */
7180 TREE_VEC_LENGTH (arglist) = saved_depth;
7182 arglist = bound_args;
7186 = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parmlist),
7187 INNERMOST_TEMPLATE_ARGS (arglist),
7190 /*require_all_args=*/true,
7191 /*use_default_args=*/true);
7193 if (arglist == error_mark_node)
7194 /* We were unable to bind the arguments. */
7195 return error_mark_node;
7197 /* In the scope of a template class, explicit references to the
7198 template class refer to the type of the template, not any
7199 instantiation of it. For example, in:
7201 template <class T> class C { void f(C<T>); }
7203 the `C<T>' is just the same as `C'. Outside of the
7204 class, however, such a reference is an instantiation. */
7206 || !PRIMARY_TEMPLATE_P (gen_tmpl)
7207 || currently_open_class (template_type))
7208 /* comp_template_args is expensive, check it last. */
7209 && comp_template_args (TYPE_TI_ARGS (template_type),
7211 return template_type;
7213 /* If we already have this specialization, return it. */
7214 elt.tmpl = gen_tmpl;
7216 hash = hash_specialization (&elt);
7217 entry = (spec_entry *) htab_find_with_hash (type_specializations,
7223 is_dependent_type = uses_template_parms (arglist);
7225 /* If the deduced arguments are invalid, then the binding
7227 if (!is_dependent_type
7228 && check_instantiated_args (gen_tmpl,
7229 INNERMOST_TEMPLATE_ARGS (arglist),
7231 return error_mark_node;
7233 if (!is_dependent_type
7234 && !PRIMARY_TEMPLATE_P (gen_tmpl)
7235 && !LAMBDA_TYPE_P (TREE_TYPE (gen_tmpl))
7236 && TREE_CODE (CP_DECL_CONTEXT (gen_tmpl)) == NAMESPACE_DECL)
7238 found = xref_tag_from_type (TREE_TYPE (gen_tmpl),
7239 DECL_NAME (gen_tmpl),
7240 /*tag_scope=*/ts_global);
7244 context = tsubst (DECL_CONTEXT (gen_tmpl), arglist,
7247 context = global_namespace;
7249 /* Create the type. */
7250 if (TREE_CODE (template_type) == ENUMERAL_TYPE)
7252 if (!is_dependent_type)
7254 set_current_access_from_decl (TYPE_NAME (template_type));
7255 t = start_enum (TYPE_IDENTIFIER (template_type), NULL_TREE,
7256 tsubst (ENUM_UNDERLYING_TYPE (template_type),
7257 arglist, complain, in_decl),
7258 SCOPED_ENUM_P (template_type), NULL);
7262 /* We don't want to call start_enum for this type, since
7263 the values for the enumeration constants may involve
7264 template parameters. And, no one should be interested
7265 in the enumeration constants for such a type. */
7266 t = cxx_make_type (ENUMERAL_TYPE);
7267 SET_SCOPED_ENUM_P (t, SCOPED_ENUM_P (template_type));
7269 SET_OPAQUE_ENUM_P (t, OPAQUE_ENUM_P (template_type));
7270 ENUM_FIXED_UNDERLYING_TYPE_P (t)
7271 = ENUM_FIXED_UNDERLYING_TYPE_P (template_type);
7275 t = make_class_type (TREE_CODE (template_type));
7276 CLASSTYPE_DECLARED_CLASS (t)
7277 = CLASSTYPE_DECLARED_CLASS (template_type);
7278 SET_CLASSTYPE_IMPLICIT_INSTANTIATION (t);
7279 TYPE_FOR_JAVA (t) = TYPE_FOR_JAVA (template_type);
7281 /* A local class. Make sure the decl gets registered properly. */
7282 if (context == current_function_decl)
7283 pushtag (DECL_NAME (gen_tmpl), t, /*tag_scope=*/ts_current);
7285 if (comp_template_args (CLASSTYPE_TI_ARGS (template_type), arglist))
7286 /* This instantiation is another name for the primary
7287 template type. Set the TYPE_CANONICAL field
7289 TYPE_CANONICAL (t) = template_type;
7290 else if (any_template_arguments_need_structural_equality_p (arglist))
7291 /* Some of the template arguments require structural
7292 equality testing, so this template class requires
7293 structural equality testing. */
7294 SET_TYPE_STRUCTURAL_EQUALITY (t);
7297 /* If we called start_enum or pushtag above, this information
7298 will already be set up. */
7301 TYPE_CONTEXT (t) = FROB_CONTEXT (context);
7303 type_decl = create_implicit_typedef (DECL_NAME (gen_tmpl), t);
7304 DECL_CONTEXT (type_decl) = TYPE_CONTEXT (t);
7305 DECL_SOURCE_LOCATION (type_decl)
7306 = DECL_SOURCE_LOCATION (TYPE_STUB_DECL (template_type));
7309 type_decl = TYPE_NAME (t);
7311 TREE_PRIVATE (type_decl)
7312 = TREE_PRIVATE (TYPE_STUB_DECL (template_type));
7313 TREE_PROTECTED (type_decl)
7314 = TREE_PROTECTED (TYPE_STUB_DECL (template_type));
7315 if (CLASSTYPE_VISIBILITY_SPECIFIED (template_type))
7317 DECL_VISIBILITY_SPECIFIED (type_decl) = 1;
7318 DECL_VISIBILITY (type_decl) = CLASSTYPE_VISIBILITY (template_type);
7321 /* Let's consider the explicit specialization of a member
7322 of a class template specialization that is implicitely instantiated,
7327 template<class U> struct M {}; //#0
7332 struct S<int>::M<char> //#1
7336 [temp.expl.spec]/4 says this is valid.
7338 In this case, when we write:
7341 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7344 When we encounter #1, we want to store the partial instantiation
7345 of M (template<class T> S<int>::M<T>) in it's CLASSTYPE_TI_TEMPLATE.
7347 For all cases other than this "explicit specialization of member of a
7348 class template", we just want to store the most general template into
7349 the CLASSTYPE_TI_TEMPLATE of M.
7351 This case of "explicit specialization of member of a class template"
7353 1/ the enclosing class is an instantiation of, and therefore not
7354 the same as, the context of the most general template, and
7355 2/ we aren't looking at the partial instantiation itself, i.e.
7356 the innermost arguments are not the same as the innermost parms of
7357 the most general template.
7359 So it's only when 1/ and 2/ happens that we want to use the partial
7360 instantiation of the member template in lieu of its most general
7363 if (PRIMARY_TEMPLATE_P (gen_tmpl)
7364 && TMPL_ARGS_HAVE_MULTIPLE_LEVELS (arglist)
7365 /* the enclosing class must be an instantiation... */
7366 && CLASS_TYPE_P (context)
7367 && !same_type_p (context, DECL_CONTEXT (gen_tmpl)))
7369 tree partial_inst_args;
7370 TREE_VEC_LENGTH (arglist)--;
7371 ++processing_template_decl;
7373 tsubst (INNERMOST_TEMPLATE_ARGS
7374 (CLASSTYPE_TI_ARGS (TREE_TYPE (gen_tmpl))),
7375 arglist, complain, NULL_TREE);
7376 --processing_template_decl;
7377 TREE_VEC_LENGTH (arglist)++;
7378 use_partial_inst_tmpl =
7379 /*...and we must not be looking at the partial instantiation
7381 !comp_template_args (INNERMOST_TEMPLATE_ARGS (arglist),
7385 if (!use_partial_inst_tmpl)
7386 /* This case is easy; there are no member templates involved. */
7390 /* This is a full instantiation of a member template. Find
7391 the partial instantiation of which this is an instance. */
7393 /* Temporarily reduce by one the number of levels in the ARGLIST
7394 so as to avoid comparing the last set of arguments. */
7395 TREE_VEC_LENGTH (arglist)--;
7396 found = tsubst (gen_tmpl, arglist, complain, NULL_TREE);
7397 TREE_VEC_LENGTH (arglist)++;
7398 found = CLASSTYPE_TI_TEMPLATE (found);
7401 SET_TYPE_TEMPLATE_INFO (t, build_template_info (found, arglist));
7404 slot = (spec_entry **) htab_find_slot_with_hash (type_specializations,
7405 &elt, hash, INSERT);
7406 *slot = ggc_alloc_spec_entry ();
7409 /* Note this use of the partial instantiation so we can check it
7410 later in maybe_process_partial_specialization. */
7411 DECL_TEMPLATE_INSTANTIATIONS (templ)
7412 = tree_cons (arglist, t,
7413 DECL_TEMPLATE_INSTANTIATIONS (templ));
7415 if (TREE_CODE (t) == ENUMERAL_TYPE && !is_dependent_type)
7416 /* Now that the type has been registered on the instantiations
7417 list, we set up the enumerators. Because the enumeration
7418 constants may involve the enumeration type itself, we make
7419 sure to register the type first, and then create the
7420 constants. That way, doing tsubst_expr for the enumeration
7421 constants won't result in recursive calls here; we'll find
7422 the instantiation and exit above. */
7423 tsubst_enum (template_type, t, arglist);
7425 if (is_dependent_type)
7426 /* If the type makes use of template parameters, the
7427 code that generates debugging information will crash. */
7428 DECL_IGNORED_P (TYPE_STUB_DECL (t)) = 1;
7430 /* Possibly limit visibility based on template args. */
7431 TREE_PUBLIC (type_decl) = 1;
7432 determine_visibility (type_decl);
7438 /* Wrapper for lookup_template_class_1. */
7441 lookup_template_class (tree d1, tree arglist, tree in_decl, tree context,
7442 int entering_scope, tsubst_flags_t complain)
7445 timevar_push (TV_TEMPLATE_INST);
7446 ret = lookup_template_class_1 (d1, arglist, in_decl, context,
7447 entering_scope, complain);
7448 timevar_pop (TV_TEMPLATE_INST);
7456 /* True when we should also visit template parameters that occur in
7457 non-deduced contexts. */
7458 bool include_nondeduced_p;
7459 struct pointer_set_t *visited;
7462 /* Called from for_each_template_parm via walk_tree. */
7465 for_each_template_parm_r (tree *tp, int *walk_subtrees, void *d)
7468 struct pair_fn_data *pfd = (struct pair_fn_data *) d;
7469 tree_fn_t fn = pfd->fn;
7470 void *data = pfd->data;
7473 && (pfd->include_nondeduced_p || TREE_CODE (t) != TYPENAME_TYPE)
7474 && for_each_template_parm (TYPE_CONTEXT (t), fn, data, pfd->visited,
7475 pfd->include_nondeduced_p))
7476 return error_mark_node;
7478 switch (TREE_CODE (t))
7481 if (TYPE_PTRMEMFUNC_P (t))
7487 if (!TYPE_TEMPLATE_INFO (t))
7489 else if (for_each_template_parm (TI_ARGS (TYPE_TEMPLATE_INFO (t)),
7490 fn, data, pfd->visited,
7491 pfd->include_nondeduced_p))
7492 return error_mark_node;
7496 if (for_each_template_parm (TYPE_MIN_VALUE (t),
7497 fn, data, pfd->visited,
7498 pfd->include_nondeduced_p)
7499 || for_each_template_parm (TYPE_MAX_VALUE (t),
7500 fn, data, pfd->visited,
7501 pfd->include_nondeduced_p))
7502 return error_mark_node;
7506 /* Since we're not going to walk subtrees, we have to do this
7508 if (for_each_template_parm (TYPE_METHOD_BASETYPE (t), fn, data,
7509 pfd->visited, pfd->include_nondeduced_p))
7510 return error_mark_node;
7514 /* Check the return type. */
7515 if (for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
7516 pfd->include_nondeduced_p))
7517 return error_mark_node;
7519 /* Check the parameter types. Since default arguments are not
7520 instantiated until they are needed, the TYPE_ARG_TYPES may
7521 contain expressions that involve template parameters. But,
7522 no-one should be looking at them yet. And, once they're
7523 instantiated, they don't contain template parameters, so
7524 there's no point in looking at them then, either. */
7528 for (parm = TYPE_ARG_TYPES (t); parm; parm = TREE_CHAIN (parm))
7529 if (for_each_template_parm (TREE_VALUE (parm), fn, data,
7530 pfd->visited, pfd->include_nondeduced_p))
7531 return error_mark_node;
7533 /* Since we've already handled the TYPE_ARG_TYPES, we don't
7534 want walk_tree walking into them itself. */
7540 case UNDERLYING_TYPE:
7541 if (pfd->include_nondeduced_p
7542 && for_each_template_parm (TYPE_FIELDS (t), fn, data,
7544 pfd->include_nondeduced_p))
7545 return error_mark_node;
7550 if (DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t)
7551 && for_each_template_parm (DECL_TI_ARGS (t), fn, data,
7552 pfd->visited, pfd->include_nondeduced_p))
7553 return error_mark_node;
7558 if (TREE_CODE (t) == CONST_DECL && DECL_TEMPLATE_PARM_P (t)
7559 && for_each_template_parm (DECL_INITIAL (t), fn, data,
7560 pfd->visited, pfd->include_nondeduced_p))
7561 return error_mark_node;
7562 if (DECL_CONTEXT (t)
7563 && pfd->include_nondeduced_p
7564 && for_each_template_parm (DECL_CONTEXT (t), fn, data,
7565 pfd->visited, pfd->include_nondeduced_p))
7566 return error_mark_node;
7569 case BOUND_TEMPLATE_TEMPLATE_PARM:
7570 /* Record template parameters such as `T' inside `TT<T>'. */
7571 if (for_each_template_parm (TYPE_TI_ARGS (t), fn, data, pfd->visited,
7572 pfd->include_nondeduced_p))
7573 return error_mark_node;
7576 case TEMPLATE_TEMPLATE_PARM:
7577 case TEMPLATE_TYPE_PARM:
7578 case TEMPLATE_PARM_INDEX:
7579 if (fn && (*fn)(t, data))
7580 return error_mark_node;
7582 return error_mark_node;
7586 /* A template template parameter is encountered. */
7587 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t)
7588 && for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
7589 pfd->include_nondeduced_p))
7590 return error_mark_node;
7592 /* Already substituted template template parameter */
7598 || for_each_template_parm (TYPENAME_TYPE_FULLNAME (t), fn,
7600 pfd->include_nondeduced_p))
7601 return error_mark_node;
7605 if (TREE_TYPE (t) && TYPE_PTRMEMFUNC_P (TREE_TYPE (t))
7606 && pfd->include_nondeduced_p
7607 && for_each_template_parm (TYPE_PTRMEMFUNC_FN_TYPE
7608 (TREE_TYPE (t)), fn, data,
7609 pfd->visited, pfd->include_nondeduced_p))
7610 return error_mark_node;
7615 /* If there's no type, then this thing must be some expression
7616 involving template parameters. */
7617 if (!fn && !TREE_TYPE (t))
7618 return error_mark_node;
7623 case REINTERPRET_CAST_EXPR:
7624 case CONST_CAST_EXPR:
7625 case STATIC_CAST_EXPR:
7626 case DYNAMIC_CAST_EXPR:
7630 case PSEUDO_DTOR_EXPR:
7632 return error_mark_node;
7639 /* We didn't find any template parameters we liked. */
7643 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
7644 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
7645 call FN with the parameter and the DATA.
7646 If FN returns nonzero, the iteration is terminated, and
7647 for_each_template_parm returns 1. Otherwise, the iteration
7648 continues. If FN never returns a nonzero value, the value
7649 returned by for_each_template_parm is 0. If FN is NULL, it is
7650 considered to be the function which always returns 1.
7652 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
7653 parameters that occur in non-deduced contexts. When false, only
7654 visits those template parameters that can be deduced. */
7657 for_each_template_parm (tree t, tree_fn_t fn, void* data,
7658 struct pointer_set_t *visited,
7659 bool include_nondeduced_p)
7661 struct pair_fn_data pfd;
7667 pfd.include_nondeduced_p = include_nondeduced_p;
7669 /* Walk the tree. (Conceptually, we would like to walk without
7670 duplicates, but for_each_template_parm_r recursively calls
7671 for_each_template_parm, so we would need to reorganize a fair
7672 bit to use walk_tree_without_duplicates, so we keep our own
7675 pfd.visited = visited;
7677 pfd.visited = pointer_set_create ();
7678 result = cp_walk_tree (&t,
7679 for_each_template_parm_r,
7681 pfd.visited) != NULL_TREE;
7686 pointer_set_destroy (pfd.visited);
7693 /* Returns true if T depends on any template parameter. */
7696 uses_template_parms (tree t)
7699 int saved_processing_template_decl;
7701 saved_processing_template_decl = processing_template_decl;
7702 if (!saved_processing_template_decl)
7703 processing_template_decl = 1;
7705 dependent_p = dependent_type_p (t);
7706 else if (TREE_CODE (t) == TREE_VEC)
7707 dependent_p = any_dependent_template_arguments_p (t);
7708 else if (TREE_CODE (t) == TREE_LIST)
7709 dependent_p = (uses_template_parms (TREE_VALUE (t))
7710 || uses_template_parms (TREE_CHAIN (t)));
7711 else if (TREE_CODE (t) == TYPE_DECL)
7712 dependent_p = dependent_type_p (TREE_TYPE (t));
7715 || TREE_CODE (t) == TEMPLATE_PARM_INDEX
7716 || TREE_CODE (t) == OVERLOAD
7717 || TREE_CODE (t) == BASELINK
7718 || TREE_CODE (t) == IDENTIFIER_NODE
7719 || TREE_CODE (t) == TRAIT_EXPR
7720 || TREE_CODE (t) == CONSTRUCTOR
7721 || CONSTANT_CLASS_P (t))
7722 dependent_p = (type_dependent_expression_p (t)
7723 || value_dependent_expression_p (t));
7726 gcc_assert (t == error_mark_node);
7727 dependent_p = false;
7730 processing_template_decl = saved_processing_template_decl;
7735 /* Returns true if T depends on any template parameter with level LEVEL. */
7738 uses_template_parms_level (tree t, int level)
7740 return for_each_template_parm (t, template_parm_this_level_p, &level, NULL,
7741 /*include_nondeduced_p=*/true);
7744 /* Returns TRUE iff INST is an instantiation we don't need to do in an
7745 ill-formed translation unit, i.e. a variable or function that isn't
7746 usable in a constant expression. */
7749 neglectable_inst_p (tree d)
7752 && !(TREE_CODE (d) == FUNCTION_DECL ? DECL_DECLARED_CONSTEXPR_P (d)
7753 : decl_maybe_constant_var_p (d)));
7756 /* Returns TRUE iff we should refuse to instantiate DECL because it's
7757 neglectable and instantiated from within an erroneous instantiation. */
7760 limit_bad_template_recursion (tree decl)
7762 struct tinst_level *lev = current_tinst_level;
7763 int errs = errorcount + sorrycount;
7764 if (lev == NULL || errs == 0 || !neglectable_inst_p (decl))
7767 for (; lev; lev = lev->next)
7768 if (neglectable_inst_p (lev->decl))
7771 return (lev && errs > lev->errors);
7774 static int tinst_depth;
7775 extern int max_tinst_depth;
7776 #ifdef GATHER_STATISTICS
7779 static GTY(()) struct tinst_level *last_error_tinst_level;
7781 /* We're starting to instantiate D; record the template instantiation context
7782 for diagnostics and to restore it later. */
7785 push_tinst_level (tree d)
7787 struct tinst_level *new_level;
7789 if (tinst_depth >= max_tinst_depth)
7791 last_error_tinst_level = current_tinst_level;
7792 if (TREE_CODE (d) == TREE_LIST)
7793 error ("template instantiation depth exceeds maximum of %d (use "
7794 "-ftemplate-depth= to increase the maximum) substituting %qS",
7795 max_tinst_depth, d);
7797 error ("template instantiation depth exceeds maximum of %d (use "
7798 "-ftemplate-depth= to increase the maximum) instantiating %qD",
7799 max_tinst_depth, d);
7801 print_instantiation_context ();
7806 /* If the current instantiation caused problems, don't let it instantiate
7807 anything else. Do allow deduction substitution and decls usable in
7808 constant expressions. */
7809 if (limit_bad_template_recursion (d))
7812 new_level = ggc_alloc_tinst_level ();
7813 new_level->decl = d;
7814 new_level->locus = input_location;
7815 new_level->errors = errorcount+sorrycount;
7816 new_level->in_system_header_p = in_system_header;
7817 new_level->next = current_tinst_level;
7818 current_tinst_level = new_level;
7821 #ifdef GATHER_STATISTICS
7822 if (tinst_depth > depth_reached)
7823 depth_reached = tinst_depth;
7829 /* We're done instantiating this template; return to the instantiation
7833 pop_tinst_level (void)
7835 /* Restore the filename and line number stashed away when we started
7836 this instantiation. */
7837 input_location = current_tinst_level->locus;
7838 current_tinst_level = current_tinst_level->next;
7842 /* We're instantiating a deferred template; restore the template
7843 instantiation context in which the instantiation was requested, which
7844 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
7847 reopen_tinst_level (struct tinst_level *level)
7849 struct tinst_level *t;
7852 for (t = level; t; t = t->next)
7855 current_tinst_level = level;
7857 if (current_tinst_level)
7858 current_tinst_level->errors = errorcount+sorrycount;
7862 /* Returns the TINST_LEVEL which gives the original instantiation
7865 struct tinst_level *
7866 outermost_tinst_level (void)
7868 struct tinst_level *level = current_tinst_level;
7871 level = level->next;
7875 /* Returns TRUE if PARM is a parameter of the template TEMPL. */
7878 parameter_of_template_p (tree parm, tree templ)
7883 if (!parm || !templ)
7886 gcc_assert (DECL_TEMPLATE_PARM_P (parm));
7887 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
7889 parms = DECL_TEMPLATE_PARMS (templ);
7890 parms = INNERMOST_TEMPLATE_PARMS (parms);
7892 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
7893 if (parm == TREE_VALUE (TREE_VEC_ELT (parms, i)))
7899 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
7900 vector of template arguments, as for tsubst.
7902 Returns an appropriate tsubst'd friend declaration. */
7905 tsubst_friend_function (tree decl, tree args)
7909 if (TREE_CODE (decl) == FUNCTION_DECL
7910 && DECL_TEMPLATE_INSTANTIATION (decl)
7911 && TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
7912 /* This was a friend declared with an explicit template
7913 argument list, e.g.:
7917 to indicate that f was a template instantiation, not a new
7918 function declaration. Now, we have to figure out what
7919 instantiation of what template. */
7921 tree template_id, arglist, fns;
7924 tree ns = decl_namespace_context (TYPE_MAIN_DECL (current_class_type));
7926 /* Friend functions are looked up in the containing namespace scope.
7927 We must enter that scope, to avoid finding member functions of the
7928 current class with same name. */
7929 push_nested_namespace (ns);
7930 fns = tsubst_expr (DECL_TI_TEMPLATE (decl), args,
7931 tf_warning_or_error, NULL_TREE,
7932 /*integral_constant_expression_p=*/false);
7933 pop_nested_namespace (ns);
7934 arglist = tsubst (DECL_TI_ARGS (decl), args,
7935 tf_warning_or_error, NULL_TREE);
7936 template_id = lookup_template_function (fns, arglist);
7938 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
7939 tmpl = determine_specialization (template_id, new_friend,
7941 /*need_member_template=*/0,
7942 TREE_VEC_LENGTH (args),
7944 return instantiate_template (tmpl, new_args, tf_error);
7947 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
7949 /* The NEW_FRIEND will look like an instantiation, to the
7950 compiler, but is not an instantiation from the point of view of
7951 the language. For example, we might have had:
7953 template <class T> struct S {
7954 template <class U> friend void f(T, U);
7957 Then, in S<int>, template <class U> void f(int, U) is not an
7958 instantiation of anything. */
7959 if (new_friend == error_mark_node)
7960 return error_mark_node;
7962 DECL_USE_TEMPLATE (new_friend) = 0;
7963 if (TREE_CODE (decl) == TEMPLATE_DECL)
7965 DECL_USE_TEMPLATE (DECL_TEMPLATE_RESULT (new_friend)) = 0;
7966 DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (new_friend))
7967 = DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (decl));
7970 /* The mangled name for the NEW_FRIEND is incorrect. The function
7971 is not a template instantiation and should not be mangled like
7972 one. Therefore, we forget the mangling here; we'll recompute it
7973 later if we need it. */
7974 if (TREE_CODE (new_friend) != TEMPLATE_DECL)
7976 SET_DECL_RTL (new_friend, NULL);
7977 SET_DECL_ASSEMBLER_NAME (new_friend, NULL_TREE);
7980 if (DECL_NAMESPACE_SCOPE_P (new_friend))
7983 tree new_friend_template_info;
7984 tree new_friend_result_template_info;
7986 int new_friend_is_defn;
7988 /* We must save some information from NEW_FRIEND before calling
7989 duplicate decls since that function will free NEW_FRIEND if
7991 new_friend_template_info = DECL_TEMPLATE_INFO (new_friend);
7992 new_friend_is_defn =
7993 (DECL_INITIAL (DECL_TEMPLATE_RESULT
7994 (template_for_substitution (new_friend)))
7996 if (TREE_CODE (new_friend) == TEMPLATE_DECL)
7998 /* This declaration is a `primary' template. */
7999 DECL_PRIMARY_TEMPLATE (new_friend) = new_friend;
8001 new_friend_result_template_info
8002 = DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (new_friend));
8005 new_friend_result_template_info = NULL_TREE;
8007 /* Make the init_value nonzero so pushdecl knows this is a defn. */
8008 if (new_friend_is_defn)
8009 DECL_INITIAL (new_friend) = error_mark_node;
8011 /* Inside pushdecl_namespace_level, we will push into the
8012 current namespace. However, the friend function should go
8013 into the namespace of the template. */
8014 ns = decl_namespace_context (new_friend);
8015 push_nested_namespace (ns);
8016 old_decl = pushdecl_namespace_level (new_friend, /*is_friend=*/true);
8017 pop_nested_namespace (ns);
8019 if (old_decl == error_mark_node)
8020 return error_mark_node;
8022 if (old_decl != new_friend)
8024 /* This new friend declaration matched an existing
8025 declaration. For example, given:
8027 template <class T> void f(T);
8028 template <class U> class C {
8029 template <class T> friend void f(T) {}
8032 the friend declaration actually provides the definition
8033 of `f', once C has been instantiated for some type. So,
8034 old_decl will be the out-of-class template declaration,
8035 while new_friend is the in-class definition.
8037 But, if `f' was called before this point, the
8038 instantiation of `f' will have DECL_TI_ARGS corresponding
8039 to `T' but not to `U', references to which might appear
8040 in the definition of `f'. Previously, the most general
8041 template for an instantiation of `f' was the out-of-class
8042 version; now it is the in-class version. Therefore, we
8043 run through all specialization of `f', adding to their
8044 DECL_TI_ARGS appropriately. In particular, they need a
8045 new set of outer arguments, corresponding to the
8046 arguments for this class instantiation.
8048 The same situation can arise with something like this:
8051 template <class T> class C {
8055 when `C<int>' is instantiated. Now, `f(int)' is defined
8058 if (!new_friend_is_defn)
8059 /* On the other hand, if the in-class declaration does
8060 *not* provide a definition, then we don't want to alter
8061 existing definitions. We can just leave everything
8066 tree new_template = TI_TEMPLATE (new_friend_template_info);
8067 tree new_args = TI_ARGS (new_friend_template_info);
8069 /* Overwrite whatever template info was there before, if
8070 any, with the new template information pertaining to
8072 DECL_TEMPLATE_INFO (old_decl) = new_friend_template_info;
8074 if (TREE_CODE (old_decl) != TEMPLATE_DECL)
8076 /* We should have called reregister_specialization in
8078 gcc_assert (retrieve_specialization (new_template,
8082 /* Instantiate it if the global has already been used. */
8083 if (DECL_ODR_USED (old_decl))
8084 instantiate_decl (old_decl, /*defer_ok=*/true,
8085 /*expl_inst_class_mem_p=*/false);
8091 /* Indicate that the old function template is a partial
8093 DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (old_decl))
8094 = new_friend_result_template_info;
8096 gcc_assert (new_template
8097 == most_general_template (new_template));
8098 gcc_assert (new_template != old_decl);
8100 /* Reassign any specializations already in the hash table
8101 to the new more general template, and add the
8102 additional template args. */
8103 for (t = DECL_TEMPLATE_INSTANTIATIONS (old_decl);
8107 tree spec = TREE_VALUE (t);
8110 elt.tmpl = old_decl;
8111 elt.args = DECL_TI_ARGS (spec);
8112 elt.spec = NULL_TREE;
8114 htab_remove_elt (decl_specializations, &elt);
8117 = add_outermost_template_args (new_args,
8118 DECL_TI_ARGS (spec));
8120 register_specialization
8121 (spec, new_template, DECL_TI_ARGS (spec), true, 0);
8124 DECL_TEMPLATE_INSTANTIATIONS (old_decl) = NULL_TREE;
8128 /* The information from NEW_FRIEND has been merged into OLD_DECL
8129 by duplicate_decls. */
8130 new_friend = old_decl;
8135 tree context = DECL_CONTEXT (new_friend);
8139 template <class T> class C {
8140 template <class U> friend void C1<U>::f (); // case 1
8141 friend void C2<T>::f (); // case 2
8143 we only need to make sure CONTEXT is a complete type for
8144 case 2. To distinguish between the two cases, we note that
8145 CONTEXT of case 1 remains dependent type after tsubst while
8146 this isn't true for case 2. */
8147 ++processing_template_decl;
8148 dependent_p = dependent_type_p (context);
8149 --processing_template_decl;
8152 && !complete_type_or_else (context, NULL_TREE))
8153 return error_mark_node;
8155 if (COMPLETE_TYPE_P (context))
8157 /* Check to see that the declaration is really present, and,
8158 possibly obtain an improved declaration. */
8159 tree fn = check_classfn (context,
8160 new_friend, NULL_TREE);
8170 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
8171 template arguments, as for tsubst.
8173 Returns an appropriate tsubst'd friend type or error_mark_node on
8177 tsubst_friend_class (tree friend_tmpl, tree args)
8183 context = CP_DECL_CONTEXT (friend_tmpl);
8185 if (context != global_namespace)
8187 if (TREE_CODE (context) == NAMESPACE_DECL)
8188 push_nested_namespace (context);
8190 push_nested_class (tsubst (context, args, tf_none, NULL_TREE));
8193 /* Look for a class template declaration. We look for hidden names
8194 because two friend declarations of the same template are the
8195 same. For example, in:
8198 template <typename> friend class F;
8200 template <typename> struct B {
8201 template <typename> friend class F;
8204 both F templates are the same. */
8205 tmpl = lookup_name_real (DECL_NAME (friend_tmpl), 0, 0,
8206 /*block_p=*/true, 0,
8207 LOOKUP_COMPLAIN | LOOKUP_HIDDEN);
8209 /* But, if we don't find one, it might be because we're in a
8210 situation like this:
8218 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
8219 for `S<int>', not the TEMPLATE_DECL. */
8220 if (!tmpl || !DECL_CLASS_TEMPLATE_P (tmpl))
8222 tmpl = lookup_name_prefer_type (DECL_NAME (friend_tmpl), 1);
8223 tmpl = maybe_get_template_decl_from_type_decl (tmpl);
8226 if (tmpl && DECL_CLASS_TEMPLATE_P (tmpl))
8228 /* The friend template has already been declared. Just
8229 check to see that the declarations match, and install any new
8230 default parameters. We must tsubst the default parameters,
8231 of course. We only need the innermost template parameters
8232 because that is all that redeclare_class_template will look
8234 if (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (friend_tmpl))
8235 > TMPL_ARGS_DEPTH (args))
8238 location_t saved_input_location;
8239 parms = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_tmpl),
8240 args, tf_warning_or_error);
8242 saved_input_location = input_location;
8243 input_location = DECL_SOURCE_LOCATION (friend_tmpl);
8244 redeclare_class_template (TREE_TYPE (tmpl), parms);
8245 input_location = saved_input_location;
8249 friend_type = TREE_TYPE (tmpl);
8253 /* The friend template has not already been declared. In this
8254 case, the instantiation of the template class will cause the
8255 injection of this template into the global scope. */
8256 tmpl = tsubst (friend_tmpl, args, tf_warning_or_error, NULL_TREE);
8257 if (tmpl == error_mark_node)
8258 return error_mark_node;
8260 /* The new TMPL is not an instantiation of anything, so we
8261 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
8262 the new type because that is supposed to be the corresponding
8263 template decl, i.e., TMPL. */
8264 DECL_USE_TEMPLATE (tmpl) = 0;
8265 DECL_TEMPLATE_INFO (tmpl) = NULL_TREE;
8266 CLASSTYPE_USE_TEMPLATE (TREE_TYPE (tmpl)) = 0;
8267 CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl))
8268 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl)));
8270 /* Inject this template into the global scope. */
8271 friend_type = TREE_TYPE (pushdecl_top_level_maybe_friend (tmpl, true));
8274 if (context != global_namespace)
8276 if (TREE_CODE (context) == NAMESPACE_DECL)
8277 pop_nested_namespace (context);
8279 pop_nested_class ();
8285 /* Returns zero if TYPE cannot be completed later due to circularity.
8286 Otherwise returns one. */
8289 can_complete_type_without_circularity (tree type)
8291 if (type == NULL_TREE || type == error_mark_node)
8293 else if (COMPLETE_TYPE_P (type))
8295 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
8296 return can_complete_type_without_circularity (TREE_TYPE (type));
8297 else if (CLASS_TYPE_P (type)
8298 && TYPE_BEING_DEFINED (TYPE_MAIN_VARIANT (type)))
8304 /* Apply any attributes which had to be deferred until instantiation
8305 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
8306 ARGS, COMPLAIN, IN_DECL are as tsubst. */
8309 apply_late_template_attributes (tree *decl_p, tree attributes, int attr_flags,
8310 tree args, tsubst_flags_t complain, tree in_decl)
8312 tree last_dep = NULL_TREE;
8316 for (t = attributes; t; t = TREE_CHAIN (t))
8317 if (ATTR_IS_DEPENDENT (t))
8320 attributes = copy_list (attributes);
8324 if (DECL_P (*decl_p))
8326 if (TREE_TYPE (*decl_p) == error_mark_node)
8328 p = &DECL_ATTRIBUTES (*decl_p);
8331 p = &TYPE_ATTRIBUTES (*decl_p);
8335 tree late_attrs = NULL_TREE;
8336 tree *q = &late_attrs;
8338 for (*p = attributes; *p; )
8341 if (ATTR_IS_DEPENDENT (t))
8343 *p = TREE_CHAIN (t);
8344 TREE_CHAIN (t) = NULL_TREE;
8345 /* If the first attribute argument is an identifier, don't
8346 pass it through tsubst. Attributes like mode, format,
8347 cleanup and several target specific attributes expect it
8350 && TREE_CODE (TREE_VALUE (t)) == TREE_LIST
8351 && TREE_VALUE (TREE_VALUE (t))
8352 && (TREE_CODE (TREE_VALUE (TREE_VALUE (t)))
8353 == IDENTIFIER_NODE))
8356 = tsubst_expr (TREE_CHAIN (TREE_VALUE (t)), args, complain,
8358 /*integral_constant_expression_p=*/false);
8359 if (chain != TREE_CHAIN (TREE_VALUE (t)))
8361 = tree_cons (NULL_TREE, TREE_VALUE (TREE_VALUE (t)),
8366 = tsubst_expr (TREE_VALUE (t), args, complain, in_decl,
8367 /*integral_constant_expression_p=*/false);
8369 q = &TREE_CHAIN (t);
8372 p = &TREE_CHAIN (t);
8375 cplus_decl_attributes (decl_p, late_attrs, attr_flags);
8379 /* Perform (or defer) access check for typedefs that were referenced
8380 from within the template TMPL code.
8381 This is a subroutine of instantiate_template and instantiate_class_template.
8382 TMPL is the template to consider and TARGS is the list of arguments of
8386 perform_typedefs_access_check (tree tmpl, tree targs)
8388 location_t saved_location;
8390 qualified_typedef_usage_t *iter;
8393 || (!CLASS_TYPE_P (tmpl)
8394 && TREE_CODE (tmpl) != FUNCTION_DECL))
8397 saved_location = input_location;
8398 FOR_EACH_VEC_ELT (qualified_typedef_usage_t,
8399 get_types_needing_access_check (tmpl),
8402 tree type_decl = iter->typedef_decl;
8403 tree type_scope = iter->context;
8405 if (!type_decl || !type_scope || !CLASS_TYPE_P (type_scope))
8408 if (uses_template_parms (type_decl))
8409 type_decl = tsubst (type_decl, targs, tf_error, NULL_TREE);
8410 if (uses_template_parms (type_scope))
8411 type_scope = tsubst (type_scope, targs, tf_error, NULL_TREE);
8413 /* Make access check error messages point to the location
8414 of the use of the typedef. */
8415 input_location = iter->locus;
8416 perform_or_defer_access_check (TYPE_BINFO (type_scope),
8417 type_decl, type_decl);
8419 input_location = saved_location;
8423 instantiate_class_template_1 (tree type)
8425 tree templ, args, pattern, t, member;
8429 unsigned int saved_maximum_field_alignment;
8431 if (type == error_mark_node)
8432 return error_mark_node;
8434 if (COMPLETE_OR_OPEN_TYPE_P (type)
8435 || uses_template_parms (type))
8438 /* Figure out which template is being instantiated. */
8439 templ = most_general_template (CLASSTYPE_TI_TEMPLATE (type));
8440 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
8442 /* Determine what specialization of the original template to
8444 t = most_specialized_class (type, templ, tf_warning_or_error);
8445 if (t == error_mark_node)
8447 TYPE_BEING_DEFINED (type) = 1;
8448 return error_mark_node;
8452 /* This TYPE is actually an instantiation of a partial
8453 specialization. We replace the innermost set of ARGS with
8454 the arguments appropriate for substitution. For example,
8457 template <class T> struct S {};
8458 template <class T> struct S<T*> {};
8460 and supposing that we are instantiating S<int*>, ARGS will
8461 presently be {int*} -- but we need {int}. */
8462 pattern = TREE_TYPE (t);
8463 args = TREE_PURPOSE (t);
8467 pattern = TREE_TYPE (templ);
8468 args = CLASSTYPE_TI_ARGS (type);
8471 /* If the template we're instantiating is incomplete, then clearly
8472 there's nothing we can do. */
8473 if (!COMPLETE_TYPE_P (pattern))
8476 /* If we've recursively instantiated too many templates, stop. */
8477 if (! push_tinst_level (type))
8480 /* Now we're really doing the instantiation. Mark the type as in
8481 the process of being defined. */
8482 TYPE_BEING_DEFINED (type) = 1;
8484 /* We may be in the middle of deferred access check. Disable
8486 push_deferring_access_checks (dk_no_deferred);
8488 push_to_top_level ();
8489 /* Use #pragma pack from the template context. */
8490 saved_maximum_field_alignment = maximum_field_alignment;
8491 maximum_field_alignment = TYPE_PRECISION (pattern);
8493 SET_CLASSTYPE_INTERFACE_UNKNOWN (type);
8495 /* Set the input location to the most specialized template definition.
8496 This is needed if tsubsting causes an error. */
8497 typedecl = TYPE_MAIN_DECL (pattern);
8498 input_location = DECL_SOURCE_LOCATION (TYPE_NAME (type)) =
8499 DECL_SOURCE_LOCATION (typedecl);
8501 TYPE_HAS_USER_CONSTRUCTOR (type) = TYPE_HAS_USER_CONSTRUCTOR (pattern);
8502 TYPE_HAS_NEW_OPERATOR (type) = TYPE_HAS_NEW_OPERATOR (pattern);
8503 TYPE_HAS_ARRAY_NEW_OPERATOR (type) = TYPE_HAS_ARRAY_NEW_OPERATOR (pattern);
8504 TYPE_GETS_DELETE (type) = TYPE_GETS_DELETE (pattern);
8505 TYPE_HAS_COPY_ASSIGN (type) = TYPE_HAS_COPY_ASSIGN (pattern);
8506 TYPE_HAS_CONST_COPY_ASSIGN (type) = TYPE_HAS_CONST_COPY_ASSIGN (pattern);
8507 TYPE_HAS_COPY_CTOR (type) = TYPE_HAS_COPY_CTOR (pattern);
8508 TYPE_HAS_CONST_COPY_CTOR (type) = TYPE_HAS_CONST_COPY_CTOR (pattern);
8509 TYPE_HAS_DEFAULT_CONSTRUCTOR (type) = TYPE_HAS_DEFAULT_CONSTRUCTOR (pattern);
8510 TYPE_HAS_CONVERSION (type) = TYPE_HAS_CONVERSION (pattern);
8511 TYPE_PACKED (type) = TYPE_PACKED (pattern);
8512 TYPE_ALIGN (type) = TYPE_ALIGN (pattern);
8513 TYPE_USER_ALIGN (type) = TYPE_USER_ALIGN (pattern);
8514 TYPE_FOR_JAVA (type) = TYPE_FOR_JAVA (pattern); /* For libjava's JArray<T> */
8515 if (ANON_AGGR_TYPE_P (pattern))
8516 SET_ANON_AGGR_TYPE_P (type);
8517 if (CLASSTYPE_VISIBILITY_SPECIFIED (pattern))
8519 CLASSTYPE_VISIBILITY_SPECIFIED (type) = 1;
8520 CLASSTYPE_VISIBILITY (type) = CLASSTYPE_VISIBILITY (pattern);
8522 CLASSTYPE_FINAL (type) = CLASSTYPE_FINAL (pattern);
8524 pbinfo = TYPE_BINFO (pattern);
8526 /* We should never instantiate a nested class before its enclosing
8527 class; we need to look up the nested class by name before we can
8528 instantiate it, and that lookup should instantiate the enclosing
8530 gcc_assert (!DECL_CLASS_SCOPE_P (TYPE_MAIN_DECL (pattern))
8531 || COMPLETE_OR_OPEN_TYPE_P (TYPE_CONTEXT (type)));
8533 base_list = NULL_TREE;
8534 if (BINFO_N_BASE_BINFOS (pbinfo))
8540 /* We must enter the scope containing the type, as that is where
8541 the accessibility of types named in dependent bases are
8543 pushed_scope = push_scope (CP_TYPE_CONTEXT (type));
8545 /* Substitute into each of the bases to determine the actual
8547 for (i = 0; BINFO_BASE_ITERATE (pbinfo, i, pbase_binfo); i++)
8550 tree access = BINFO_BASE_ACCESS (pbinfo, i);
8551 tree expanded_bases = NULL_TREE;
8554 if (PACK_EXPANSION_P (BINFO_TYPE (pbase_binfo)))
8557 tsubst_pack_expansion (BINFO_TYPE (pbase_binfo),
8558 args, tf_error, NULL_TREE);
8559 if (expanded_bases == error_mark_node)
8562 len = TREE_VEC_LENGTH (expanded_bases);
8565 for (idx = 0; idx < len; idx++)
8568 /* Extract the already-expanded base class. */
8569 base = TREE_VEC_ELT (expanded_bases, idx);
8571 /* Substitute to figure out the base class. */
8572 base = tsubst (BINFO_TYPE (pbase_binfo), args, tf_error,
8575 if (base == error_mark_node)
8578 base_list = tree_cons (access, base, base_list);
8579 if (BINFO_VIRTUAL_P (pbase_binfo))
8580 TREE_TYPE (base_list) = integer_type_node;
8584 /* The list is now in reverse order; correct that. */
8585 base_list = nreverse (base_list);
8588 pop_scope (pushed_scope);
8590 /* Now call xref_basetypes to set up all the base-class
8592 xref_basetypes (type, base_list);
8594 apply_late_template_attributes (&type, TYPE_ATTRIBUTES (pattern),
8595 (int) ATTR_FLAG_TYPE_IN_PLACE,
8596 args, tf_error, NULL_TREE);
8597 fixup_attribute_variants (type);
8599 /* Now that our base classes are set up, enter the scope of the
8600 class, so that name lookups into base classes, etc. will work
8601 correctly. This is precisely analogous to what we do in
8602 begin_class_definition when defining an ordinary non-template
8603 class, except we also need to push the enclosing classes. */
8604 push_nested_class (type);
8606 /* Now members are processed in the order of declaration. */
8607 for (member = CLASSTYPE_DECL_LIST (pattern);
8608 member; member = TREE_CHAIN (member))
8610 tree t = TREE_VALUE (member);
8612 if (TREE_PURPOSE (member))
8616 /* Build new CLASSTYPE_NESTED_UTDS. */
8619 bool class_template_p;
8621 class_template_p = (TREE_CODE (t) != ENUMERAL_TYPE
8622 && TYPE_LANG_SPECIFIC (t)
8623 && CLASSTYPE_IS_TEMPLATE (t));
8624 /* If the member is a class template, then -- even after
8625 substitution -- there may be dependent types in the
8626 template argument list for the class. We increment
8627 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
8628 that function will assume that no types are dependent
8629 when outside of a template. */
8630 if (class_template_p)
8631 ++processing_template_decl;
8632 newtag = tsubst (t, args, tf_error, NULL_TREE);
8633 if (class_template_p)
8634 --processing_template_decl;
8635 if (newtag == error_mark_node)
8638 if (TREE_CODE (newtag) != ENUMERAL_TYPE)
8640 tree name = TYPE_IDENTIFIER (t);
8642 if (class_template_p)
8643 /* Unfortunately, lookup_template_class sets
8644 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
8645 instantiation (i.e., for the type of a member
8646 template class nested within a template class.)
8647 This behavior is required for
8648 maybe_process_partial_specialization to work
8649 correctly, but is not accurate in this case;
8650 the TAG is not an instantiation of anything.
8651 (The corresponding TEMPLATE_DECL is an
8652 instantiation, but the TYPE is not.) */
8653 CLASSTYPE_USE_TEMPLATE (newtag) = 0;
8655 /* Now, we call pushtag to put this NEWTAG into the scope of
8656 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
8657 pushtag calling push_template_decl. We don't have to do
8658 this for enums because it will already have been done in
8661 SET_IDENTIFIER_TYPE_VALUE (name, newtag);
8662 pushtag (name, newtag, /*tag_scope=*/ts_current);
8665 else if (TREE_CODE (t) == FUNCTION_DECL
8666 || DECL_FUNCTION_TEMPLATE_P (t))
8668 /* Build new TYPE_METHODS. */
8671 if (TREE_CODE (t) == TEMPLATE_DECL)
8672 ++processing_template_decl;
8673 r = tsubst (t, args, tf_error, NULL_TREE);
8674 if (TREE_CODE (t) == TEMPLATE_DECL)
8675 --processing_template_decl;
8676 set_current_access_from_decl (r);
8677 finish_member_declaration (r);
8681 /* Build new TYPE_FIELDS. */
8682 if (TREE_CODE (t) == STATIC_ASSERT)
8685 tsubst_expr (STATIC_ASSERT_CONDITION (t), args,
8686 tf_warning_or_error, NULL_TREE,
8687 /*integral_constant_expression_p=*/true);
8688 finish_static_assert (condition,
8689 STATIC_ASSERT_MESSAGE (t),
8690 STATIC_ASSERT_SOURCE_LOCATION (t),
8693 else if (TREE_CODE (t) != CONST_DECL)
8697 /* The file and line for this declaration, to
8698 assist in error message reporting. Since we
8699 called push_tinst_level above, we don't need to
8701 input_location = DECL_SOURCE_LOCATION (t);
8703 if (TREE_CODE (t) == TEMPLATE_DECL)
8704 ++processing_template_decl;
8705 r = tsubst (t, args, tf_warning_or_error, NULL_TREE);
8706 if (TREE_CODE (t) == TEMPLATE_DECL)
8707 --processing_template_decl;
8708 if (TREE_CODE (r) == VAR_DECL)
8712 [t]he initialization (and any associated
8713 side-effects) of a static data member does
8714 not occur unless the static data member is
8715 itself used in a way that requires the
8716 definition of the static data member to
8719 Therefore, we do not substitute into the
8720 initialized for the static data member here. */
8721 finish_static_data_member_decl
8724 /*init_const_expr_p=*/false,
8725 /*asmspec_tree=*/NULL_TREE,
8728 else if (TREE_CODE (r) == FIELD_DECL)
8730 /* Determine whether R has a valid type and can be
8731 completed later. If R is invalid, then it is
8732 replaced by error_mark_node so that it will not be
8733 added to TYPE_FIELDS. */
8734 tree rtype = TREE_TYPE (r);
8735 if (can_complete_type_without_circularity (rtype))
8736 complete_type (rtype);
8738 if (!COMPLETE_TYPE_P (rtype))
8740 cxx_incomplete_type_error (r, rtype);
8741 r = error_mark_node;
8745 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
8746 such a thing will already have been added to the field
8747 list by tsubst_enum in finish_member_declaration in the
8748 CLASSTYPE_NESTED_UTDS case above. */
8749 if (!(TREE_CODE (r) == TYPE_DECL
8750 && TREE_CODE (TREE_TYPE (r)) == ENUMERAL_TYPE
8751 && DECL_ARTIFICIAL (r)))
8753 set_current_access_from_decl (r);
8754 finish_member_declaration (r);
8761 if (TYPE_P (t) || DECL_CLASS_TEMPLATE_P (t))
8763 /* Build new CLASSTYPE_FRIEND_CLASSES. */
8765 tree friend_type = t;
8766 bool adjust_processing_template_decl = false;
8768 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
8770 /* template <class T> friend class C; */
8771 friend_type = tsubst_friend_class (friend_type, args);
8772 adjust_processing_template_decl = true;
8774 else if (TREE_CODE (friend_type) == UNBOUND_CLASS_TEMPLATE)
8776 /* template <class T> friend class C::D; */
8777 friend_type = tsubst (friend_type, args,
8778 tf_warning_or_error, NULL_TREE);
8779 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
8780 friend_type = TREE_TYPE (friend_type);
8781 adjust_processing_template_decl = true;
8783 else if (TREE_CODE (friend_type) == TYPENAME_TYPE
8784 || TREE_CODE (friend_type) == TEMPLATE_TYPE_PARM)
8786 /* This could be either
8790 when dependent_type_p is false or
8792 template <class U> friend class T::C;
8795 friend_type = tsubst (friend_type, args,
8796 tf_warning_or_error, NULL_TREE);
8797 /* Bump processing_template_decl for correct
8798 dependent_type_p calculation. */
8799 ++processing_template_decl;
8800 if (dependent_type_p (friend_type))
8801 adjust_processing_template_decl = true;
8802 --processing_template_decl;
8804 else if (!CLASSTYPE_USE_TEMPLATE (friend_type)
8805 && hidden_name_p (TYPE_NAME (friend_type)))
8809 where C hasn't been declared yet. Let's lookup name
8810 from namespace scope directly, bypassing any name that
8811 come from dependent base class. */
8812 tree ns = decl_namespace_context (TYPE_MAIN_DECL (friend_type));
8814 /* The call to xref_tag_from_type does injection for friend
8816 push_nested_namespace (ns);
8818 xref_tag_from_type (friend_type, NULL_TREE,
8819 /*tag_scope=*/ts_current);
8820 pop_nested_namespace (ns);
8822 else if (uses_template_parms (friend_type))
8823 /* friend class C<T>; */
8824 friend_type = tsubst (friend_type, args,
8825 tf_warning_or_error, NULL_TREE);
8830 where C is already declared or
8832 friend class C<int>;
8834 We don't have to do anything in these cases. */
8836 if (adjust_processing_template_decl)
8837 /* Trick make_friend_class into realizing that the friend
8838 we're adding is a template, not an ordinary class. It's
8839 important that we use make_friend_class since it will
8840 perform some error-checking and output cross-reference
8842 ++processing_template_decl;
8844 if (friend_type != error_mark_node)
8845 make_friend_class (type, friend_type, /*complain=*/false);
8847 if (adjust_processing_template_decl)
8848 --processing_template_decl;
8852 /* Build new DECL_FRIENDLIST. */
8855 /* The file and line for this declaration, to
8856 assist in error message reporting. Since we
8857 called push_tinst_level above, we don't need to
8859 input_location = DECL_SOURCE_LOCATION (t);
8861 if (TREE_CODE (t) == TEMPLATE_DECL)
8863 ++processing_template_decl;
8864 push_deferring_access_checks (dk_no_check);
8867 r = tsubst_friend_function (t, args);
8868 add_friend (type, r, /*complain=*/false);
8869 if (TREE_CODE (t) == TEMPLATE_DECL)
8871 pop_deferring_access_checks ();
8872 --processing_template_decl;
8878 if (CLASSTYPE_LAMBDA_EXPR (type))
8879 maybe_add_lambda_conv_op (type);
8881 /* Set the file and line number information to whatever is given for
8882 the class itself. This puts error messages involving generated
8883 implicit functions at a predictable point, and the same point
8884 that would be used for non-template classes. */
8885 input_location = DECL_SOURCE_LOCATION (typedecl);
8887 unreverse_member_declarations (type);
8888 finish_struct_1 (type);
8889 TYPE_BEING_DEFINED (type) = 0;
8891 /* We don't instantiate default arguments for member functions. 14.7.1:
8893 The implicit instantiation of a class template specialization causes
8894 the implicit instantiation of the declarations, but not of the
8895 definitions or default arguments, of the class member functions,
8896 member classes, static data members and member templates.... */
8898 /* Some typedefs referenced from within the template code need to be access
8899 checked at template instantiation time, i.e now. These types were
8900 added to the template at parsing time. Let's get those and perform
8901 the access checks then. */
8902 perform_typedefs_access_check (pattern, args);
8903 perform_deferred_access_checks ();
8904 pop_nested_class ();
8905 maximum_field_alignment = saved_maximum_field_alignment;
8906 pop_from_top_level ();
8907 pop_deferring_access_checks ();
8910 /* The vtable for a template class can be emitted in any translation
8911 unit in which the class is instantiated. When there is no key
8912 method, however, finish_struct_1 will already have added TYPE to
8913 the keyed_classes list. */
8914 if (TYPE_CONTAINS_VPTR_P (type) && CLASSTYPE_KEY_METHOD (type))
8915 keyed_classes = tree_cons (NULL_TREE, type, keyed_classes);
8920 /* Wrapper for instantiate_class_template_1. */
8923 instantiate_class_template (tree type)
8926 timevar_push (TV_TEMPLATE_INST);
8927 ret = instantiate_class_template_1 (type);
8928 timevar_pop (TV_TEMPLATE_INST);
8933 tsubst_template_arg (tree t, tree args, tsubst_flags_t complain, tree in_decl)
8939 else if (TYPE_P (t))
8940 r = tsubst (t, args, complain, in_decl);
8943 if (!(complain & tf_warning))
8944 ++c_inhibit_evaluation_warnings;
8945 r = tsubst_expr (t, args, complain, in_decl,
8946 /*integral_constant_expression_p=*/true);
8947 if (!(complain & tf_warning))
8948 --c_inhibit_evaluation_warnings;
8949 /* Preserve the raw-reference nature of T. */
8950 if (TREE_TYPE (t) && TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE
8951 && REFERENCE_REF_P (r))
8952 r = TREE_OPERAND (r, 0);
8957 /* Given a function parameter pack TMPL_PARM and some function parameters
8958 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
8959 and set *SPEC_P to point at the next point in the list. */
8962 extract_fnparm_pack (tree tmpl_parm, tree *spec_p)
8964 /* Collect all of the extra "packed" parameters into an
8968 tree argpack = make_node (NONTYPE_ARGUMENT_PACK);
8969 tree argtypepack = cxx_make_type (TYPE_ARGUMENT_PACK);
8970 tree spec_parm = *spec_p;
8973 for (len = 0; spec_parm; ++len, spec_parm = TREE_CHAIN (spec_parm))
8975 && !function_parameter_expanded_from_pack_p (spec_parm, tmpl_parm))
8978 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
8979 parmvec = make_tree_vec (len);
8980 parmtypevec = make_tree_vec (len);
8981 spec_parm = *spec_p;
8982 for (i = 0; i < len; i++, spec_parm = DECL_CHAIN (spec_parm))
8984 TREE_VEC_ELT (parmvec, i) = spec_parm;
8985 TREE_VEC_ELT (parmtypevec, i) = TREE_TYPE (spec_parm);
8988 /* Build the argument packs. */
8989 SET_ARGUMENT_PACK_ARGS (argpack, parmvec);
8990 SET_ARGUMENT_PACK_ARGS (argtypepack, parmtypevec);
8991 TREE_TYPE (argpack) = argtypepack;
8992 *spec_p = spec_parm;
8997 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
8998 NONTYPE_ARGUMENT_PACK. */
9001 make_fnparm_pack (tree spec_parm)
9003 return extract_fnparm_pack (NULL_TREE, &spec_parm);
9006 /* Substitute ARGS into T, which is an pack expansion
9007 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
9008 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
9009 (if only a partial substitution could be performed) or
9010 ERROR_MARK_NODE if there was an error. */
9012 tsubst_pack_expansion (tree t, tree args, tsubst_flags_t complain,
9016 tree pack, packs = NULL_TREE, unsubstituted_packs = NULL_TREE;
9020 htab_t saved_local_specializations = NULL;
9022 gcc_assert (PACK_EXPANSION_P (t));
9023 pattern = PACK_EXPANSION_PATTERN (t);
9025 /* Determine the argument packs that will instantiate the parameter
9026 packs used in the expansion expression. While we're at it,
9027 compute the number of arguments to be expanded and make sure it
9029 for (pack = PACK_EXPANSION_PARAMETER_PACKS (t); pack;
9030 pack = TREE_CHAIN (pack))
9032 tree parm_pack = TREE_VALUE (pack);
9033 tree arg_pack = NULL_TREE;
9034 tree orig_arg = NULL_TREE;
9036 if (TREE_CODE (parm_pack) == PARM_DECL)
9038 if (!cp_unevaluated_operand)
9039 arg_pack = retrieve_local_specialization (parm_pack);
9042 /* We can't rely on local_specializations for a parameter
9043 name used later in a function declaration (such as in a
9044 late-specified return type). Even if it exists, it might
9045 have the wrong value for a recursive call. Just make a
9046 dummy decl, since it's only used for its type. */
9047 arg_pack = tsubst_decl (parm_pack, args, complain);
9048 if (arg_pack && FUNCTION_PARAMETER_PACK_P (arg_pack))
9049 /* Partial instantiation of the parm_pack, we can't build
9050 up an argument pack yet. */
9051 arg_pack = NULL_TREE;
9053 arg_pack = make_fnparm_pack (arg_pack);
9058 int level, idx, levels;
9059 template_parm_level_and_index (parm_pack, &level, &idx);
9061 levels = TMPL_ARGS_DEPTH (args);
9062 if (level <= levels)
9063 arg_pack = TMPL_ARG (args, level, idx);
9066 orig_arg = arg_pack;
9067 if (arg_pack && TREE_CODE (arg_pack) == ARGUMENT_PACK_SELECT)
9068 arg_pack = ARGUMENT_PACK_SELECT_FROM_PACK (arg_pack);
9070 if (arg_pack && !ARGUMENT_PACK_P (arg_pack))
9071 /* This can only happen if we forget to expand an argument
9072 pack somewhere else. Just return an error, silently. */
9074 result = make_tree_vec (1);
9075 TREE_VEC_ELT (result, 0) = error_mark_node;
9079 /* For clarity in the comments below let's use the
9080 representation 'argument_pack<elements>' to denote an
9081 argument pack and its elements.
9083 In the 'if' block below, we want to detect cases where
9084 ARG_PACK is argument_pack<PARM_PACK...>. I.e, we want to
9085 check if ARG_PACK is an argument pack which sole element is
9086 the expansion of PARM_PACK. That argument pack is typically
9087 created by template_parm_to_arg when passed a parameter
9090 && TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack)) == 1
9091 && PACK_EXPANSION_P (TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0)))
9093 tree expansion = TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0);
9094 tree pattern = PACK_EXPANSION_PATTERN (expansion);
9095 /* So we have an argument_pack<P...>. We want to test if P
9096 is actually PARM_PACK. We will not use cp_tree_equal to
9097 test P and PARM_PACK because during type fixup (by
9098 fixup_template_parm) P can be a pre-fixup version of a
9099 type and PARM_PACK be its post-fixup version.
9100 cp_tree_equal would consider them as different even
9101 though we would want to consider them compatible for our
9102 precise purpose here.
9104 Thus we are going to consider that P and PARM_PACK are
9105 compatible if they have the same DECL. */
9106 if ((/* If ARG_PACK is a type parameter pack named by the
9107 same DECL as parm_pack ... */
9109 && TYPE_P (parm_pack)
9110 && TYPE_NAME (pattern) == TYPE_NAME (parm_pack))
9111 /* ... or if ARG_PACK is a non-type parameter
9112 named by the same DECL as parm_pack ... */
9113 || (TREE_CODE (pattern) == TEMPLATE_PARM_INDEX
9114 && TREE_CODE (parm_pack) == PARM_DECL
9115 && TEMPLATE_PARM_DECL (pattern)
9116 == TEMPLATE_PARM_DECL (DECL_INITIAL (parm_pack))))
9117 && template_parameter_pack_p (pattern))
9118 /* ... then the argument pack that the parameter maps to
9119 is just an expansion of the parameter itself, such as
9120 one would find in the implicit typedef of a class
9121 inside the class itself. Consider this parameter
9122 "unsubstituted", so that we will maintain the outer
9124 arg_pack = NULL_TREE;
9130 TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack));
9132 /* It's all-or-nothing with incomplete argument packs. */
9133 if (incomplete && !ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
9134 return error_mark_node;
9136 if (ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
9141 else if (len != my_len)
9144 /* We got explicit args for some packs but not others;
9145 do nothing now and try again after deduction. */
9147 if (TREE_CODE (t) == TYPE_PACK_EXPANSION)
9148 error ("mismatched argument pack lengths while expanding "
9152 error ("mismatched argument pack lengths while expanding "
9155 return error_mark_node;
9158 /* Keep track of the parameter packs and their corresponding
9160 packs = tree_cons (parm_pack, arg_pack, packs);
9161 TREE_TYPE (packs) = orig_arg;
9164 /* We can't substitute for this parameter pack. */
9165 unsubstituted_packs = tree_cons (TREE_PURPOSE (pack),
9167 unsubstituted_packs);
9170 /* We cannot expand this expansion expression, because we don't have
9171 all of the argument packs we need. Substitute into the pattern
9172 and return a PACK_EXPANSION_*. The caller will need to deal with
9174 if (unsubstituted_packs)
9177 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
9178 new_pat = tsubst_expr (pattern, args, complain, in_decl,
9179 /*integral_constant_expression_p=*/false);
9181 new_pat = tsubst (pattern, args, complain, in_decl);
9182 return make_pack_expansion (new_pat);
9185 /* We could not find any argument packs that work. */
9187 return error_mark_node;
9189 if (cp_unevaluated_operand)
9191 /* We're in a late-specified return type, so create our own local
9192 specializations table; the current table is either NULL or (in the
9193 case of recursive unification) might have bindings that we don't
9194 want to use or alter. */
9195 saved_local_specializations = local_specializations;
9196 local_specializations = htab_create (37,
9197 hash_local_specialization,
9198 eq_local_specializations,
9202 /* For each argument in each argument pack, substitute into the
9204 result = make_tree_vec (len + incomplete);
9205 for (i = 0; i < len + incomplete; ++i)
9207 /* For parameter pack, change the substitution of the parameter
9208 pack to the ith argument in its argument pack, then expand
9210 for (pack = packs; pack; pack = TREE_CHAIN (pack))
9212 tree parm = TREE_PURPOSE (pack);
9214 if (TREE_CODE (parm) == PARM_DECL)
9216 /* Select the Ith argument from the pack. */
9217 tree arg = make_node (ARGUMENT_PACK_SELECT);
9218 ARGUMENT_PACK_SELECT_FROM_PACK (arg) = TREE_VALUE (pack);
9219 ARGUMENT_PACK_SELECT_INDEX (arg) = i;
9221 register_local_specialization (arg, parm);
9227 template_parm_level_and_index (parm, &level, &idx);
9231 /* Select the Ith argument from the pack. */
9232 value = make_node (ARGUMENT_PACK_SELECT);
9233 ARGUMENT_PACK_SELECT_FROM_PACK (value) = TREE_VALUE (pack);
9234 ARGUMENT_PACK_SELECT_INDEX (value) = i;
9237 /* Update the corresponding argument. */
9238 TMPL_ARG (args, level, idx) = value;
9242 /* Substitute into the PATTERN with the altered arguments. */
9243 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
9244 TREE_VEC_ELT (result, i) =
9245 tsubst_expr (pattern, args, complain, in_decl,
9246 /*integral_constant_expression_p=*/false);
9248 TREE_VEC_ELT (result, i) = tsubst (pattern, args, complain, in_decl);
9251 /* When we have incomplete argument packs, the last "expanded"
9252 result is itself a pack expansion, which allows us
9253 to deduce more arguments. */
9254 TREE_VEC_ELT (result, i) =
9255 make_pack_expansion (TREE_VEC_ELT (result, i));
9257 if (TREE_VEC_ELT (result, i) == error_mark_node)
9259 result = error_mark_node;
9264 /* Update ARGS to restore the substitution from parameter packs to
9265 their argument packs. */
9266 for (pack = packs; pack; pack = TREE_CHAIN (pack))
9268 tree parm = TREE_PURPOSE (pack);
9270 if (TREE_CODE (parm) == PARM_DECL)
9271 register_local_specialization (TREE_TYPE (pack), parm);
9275 template_parm_level_and_index (parm, &level, &idx);
9277 /* Update the corresponding argument. */
9278 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
9279 TREE_VEC_ELT (TREE_VEC_ELT (args, level -1 ), idx) =
9282 TREE_VEC_ELT (args, idx) = TREE_TYPE (pack);
9286 if (saved_local_specializations)
9288 htab_delete (local_specializations);
9289 local_specializations = saved_local_specializations;
9295 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
9296 TMPL. We do this using DECL_PARM_INDEX, which should work even with
9297 parameter packs; all parms generated from a function parameter pack will
9298 have the same DECL_PARM_INDEX. */
9301 get_pattern_parm (tree parm, tree tmpl)
9303 tree pattern = DECL_TEMPLATE_RESULT (tmpl);
9306 if (DECL_ARTIFICIAL (parm))
9308 for (patparm = DECL_ARGUMENTS (pattern);
9309 patparm; patparm = DECL_CHAIN (patparm))
9310 if (DECL_ARTIFICIAL (patparm)
9311 && DECL_NAME (parm) == DECL_NAME (patparm))
9316 patparm = FUNCTION_FIRST_USER_PARM (DECL_TEMPLATE_RESULT (tmpl));
9317 patparm = chain_index (DECL_PARM_INDEX (parm)-1, patparm);
9318 gcc_assert (DECL_PARM_INDEX (patparm)
9319 == DECL_PARM_INDEX (parm));
9325 /* Substitute ARGS into the vector or list of template arguments T. */
9328 tsubst_template_args (tree t, tree args, tsubst_flags_t complain, tree in_decl)
9331 int len, need_new = 0, i, expanded_len_adjust = 0, out;
9334 if (t == error_mark_node)
9335 return error_mark_node;
9337 len = TREE_VEC_LENGTH (t);
9338 elts = XALLOCAVEC (tree, len);
9340 for (i = 0; i < len; i++)
9342 tree orig_arg = TREE_VEC_ELT (t, i);
9345 if (TREE_CODE (orig_arg) == TREE_VEC)
9346 new_arg = tsubst_template_args (orig_arg, args, complain, in_decl);
9347 else if (PACK_EXPANSION_P (orig_arg))
9349 /* Substitute into an expansion expression. */
9350 new_arg = tsubst_pack_expansion (orig_arg, args, complain, in_decl);
9352 if (TREE_CODE (new_arg) == TREE_VEC)
9353 /* Add to the expanded length adjustment the number of
9354 expanded arguments. We subtract one from this
9355 measurement, because the argument pack expression
9356 itself is already counted as 1 in
9357 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
9358 the argument pack is empty. */
9359 expanded_len_adjust += TREE_VEC_LENGTH (new_arg) - 1;
9361 else if (ARGUMENT_PACK_P (orig_arg))
9363 /* Substitute into each of the arguments. */
9364 new_arg = TYPE_P (orig_arg)
9365 ? cxx_make_type (TREE_CODE (orig_arg))
9366 : make_node (TREE_CODE (orig_arg));
9368 SET_ARGUMENT_PACK_ARGS (
9370 tsubst_template_args (ARGUMENT_PACK_ARGS (orig_arg),
9371 args, complain, in_decl));
9373 if (ARGUMENT_PACK_ARGS (new_arg) == error_mark_node)
9374 new_arg = error_mark_node;
9376 if (TREE_CODE (new_arg) == NONTYPE_ARGUMENT_PACK) {
9377 TREE_TYPE (new_arg) = tsubst (TREE_TYPE (orig_arg), args,
9379 TREE_CONSTANT (new_arg) = TREE_CONSTANT (orig_arg);
9381 if (TREE_TYPE (new_arg) == error_mark_node)
9382 new_arg = error_mark_node;
9386 new_arg = tsubst_template_arg (orig_arg, args, complain, in_decl);
9388 if (new_arg == error_mark_node)
9389 return error_mark_node;
9392 if (new_arg != orig_arg)
9399 /* Make space for the expanded arguments coming from template
9401 t = make_tree_vec (len + expanded_len_adjust);
9402 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
9403 arguments for a member template.
9404 In that case each TREE_VEC in ORIG_T represents a level of template
9405 arguments, and ORIG_T won't carry any non defaulted argument count.
9406 It will rather be the nested TREE_VECs that will carry one.
9407 In other words, ORIG_T carries a non defaulted argument count only
9408 if it doesn't contain any nested TREE_VEC. */
9409 if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t))
9411 int count = GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t);
9412 count += expanded_len_adjust;
9413 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (t, count);
9415 for (i = 0, out = 0; i < len; i++)
9417 if ((PACK_EXPANSION_P (TREE_VEC_ELT (orig_t, i))
9418 || ARGUMENT_PACK_P (TREE_VEC_ELT (orig_t, i)))
9419 && TREE_CODE (elts[i]) == TREE_VEC)
9423 /* Now expand the template argument pack "in place". */
9424 for (idx = 0; idx < TREE_VEC_LENGTH (elts[i]); idx++, out++)
9425 TREE_VEC_ELT (t, out) = TREE_VEC_ELT (elts[i], idx);
9429 TREE_VEC_ELT (t, out) = elts[i];
9437 /* Return the result of substituting ARGS into the template parameters
9438 given by PARMS. If there are m levels of ARGS and m + n levels of
9439 PARMS, then the result will contain n levels of PARMS. For
9440 example, if PARMS is `template <class T> template <class U>
9441 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
9442 result will be `template <int*, double, class V>'. */
9445 tsubst_template_parms (tree parms, tree args, tsubst_flags_t complain)
9450 /* When substituting into a template, we must set
9451 PROCESSING_TEMPLATE_DECL as the template parameters may be
9452 dependent if they are based on one-another, and the dependency
9453 predicates are short-circuit outside of templates. */
9454 ++processing_template_decl;
9456 for (new_parms = &r;
9457 TMPL_PARMS_DEPTH (parms) > TMPL_ARGS_DEPTH (args);
9458 new_parms = &(TREE_CHAIN (*new_parms)),
9459 parms = TREE_CHAIN (parms))
9462 make_tree_vec (TREE_VEC_LENGTH (TREE_VALUE (parms)));
9465 for (i = 0; i < TREE_VEC_LENGTH (new_vec); ++i)
9469 if (parms == error_mark_node)
9472 tuple = TREE_VEC_ELT (TREE_VALUE (parms), i);
9474 if (tuple == error_mark_node)
9477 TREE_VEC_ELT (new_vec, i) =
9478 tsubst_template_parm (tuple, args, complain);
9482 tree_cons (size_int (TMPL_PARMS_DEPTH (parms)
9483 - TMPL_ARGS_DEPTH (args)),
9484 new_vec, NULL_TREE);
9487 --processing_template_decl;
9492 /* Return the result of substituting ARGS into one template parameter
9493 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
9494 parameter and which TREE_PURPOSE is the default argument of the
9495 template parameter. */
9498 tsubst_template_parm (tree t, tree args, tsubst_flags_t complain)
9500 tree default_value, parm_decl;
9502 if (args == NULL_TREE
9504 || t == error_mark_node)
9507 gcc_assert (TREE_CODE (t) == TREE_LIST);
9509 default_value = TREE_PURPOSE (t);
9510 parm_decl = TREE_VALUE (t);
9512 parm_decl = tsubst (parm_decl, args, complain, NULL_TREE);
9513 if (TREE_CODE (parm_decl) == PARM_DECL
9514 && invalid_nontype_parm_type_p (TREE_TYPE (parm_decl), complain))
9515 parm_decl = error_mark_node;
9516 default_value = tsubst_template_arg (default_value, args,
9517 complain, NULL_TREE);
9519 return build_tree_list (default_value, parm_decl);
9522 /* Substitute the ARGS into the indicated aggregate (or enumeration)
9523 type T. If T is not an aggregate or enumeration type, it is
9524 handled as if by tsubst. IN_DECL is as for tsubst. If
9525 ENTERING_SCOPE is nonzero, T is the context for a template which
9526 we are presently tsubst'ing. Return the substituted value. */
9529 tsubst_aggr_type (tree t,
9531 tsubst_flags_t complain,
9538 switch (TREE_CODE (t))
9541 if (TYPE_PTRMEMFUNC_P (t))
9542 return tsubst (TYPE_PTRMEMFUNC_FN_TYPE (t), args, complain, in_decl);
9544 /* Else fall through. */
9547 if (TYPE_TEMPLATE_INFO (t) && uses_template_parms (t))
9552 int saved_unevaluated_operand;
9553 int saved_inhibit_evaluation_warnings;
9555 /* In "sizeof(X<I>)" we need to evaluate "I". */
9556 saved_unevaluated_operand = cp_unevaluated_operand;
9557 cp_unevaluated_operand = 0;
9558 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
9559 c_inhibit_evaluation_warnings = 0;
9561 /* First, determine the context for the type we are looking
9563 context = TYPE_CONTEXT (t);
9566 context = tsubst_aggr_type (context, args, complain,
9567 in_decl, /*entering_scope=*/1);
9568 /* If context is a nested class inside a class template,
9569 it may still need to be instantiated (c++/33959). */
9570 if (TYPE_P (context))
9571 context = complete_type (context);
9574 /* Then, figure out what arguments are appropriate for the
9575 type we are trying to find. For example, given:
9577 template <class T> struct S;
9578 template <class T, class U> void f(T, U) { S<U> su; }
9580 and supposing that we are instantiating f<int, double>,
9581 then our ARGS will be {int, double}, but, when looking up
9582 S we only want {double}. */
9583 argvec = tsubst_template_args (TYPE_TI_ARGS (t), args,
9585 if (argvec == error_mark_node)
9586 r = error_mark_node;
9589 r = lookup_template_class (t, argvec, in_decl, context,
9590 entering_scope, complain);
9591 r = cp_build_qualified_type_real (r, cp_type_quals (t), complain);
9594 cp_unevaluated_operand = saved_unevaluated_operand;
9595 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
9600 /* This is not a template type, so there's nothing to do. */
9604 return tsubst (t, args, complain, in_decl);
9608 /* Substitute into the default argument ARG (a default argument for
9609 FN), which has the indicated TYPE. */
9612 tsubst_default_argument (tree fn, tree type, tree arg)
9614 tree saved_class_ptr = NULL_TREE;
9615 tree saved_class_ref = NULL_TREE;
9617 /* This can happen in invalid code. */
9618 if (TREE_CODE (arg) == DEFAULT_ARG)
9621 /* This default argument came from a template. Instantiate the
9622 default argument here, not in tsubst. In the case of
9631 we must be careful to do name lookup in the scope of S<T>,
9632 rather than in the current class. */
9633 push_access_scope (fn);
9634 /* The "this" pointer is not valid in a default argument. */
9637 saved_class_ptr = current_class_ptr;
9638 cp_function_chain->x_current_class_ptr = NULL_TREE;
9639 saved_class_ref = current_class_ref;
9640 cp_function_chain->x_current_class_ref = NULL_TREE;
9643 push_deferring_access_checks(dk_no_deferred);
9644 /* The default argument expression may cause implicitly defined
9645 member functions to be synthesized, which will result in garbage
9646 collection. We must treat this situation as if we were within
9647 the body of function so as to avoid collecting live data on the
9650 arg = tsubst_expr (arg, DECL_TI_ARGS (fn),
9651 tf_warning_or_error, NULL_TREE,
9652 /*integral_constant_expression_p=*/false);
9654 pop_deferring_access_checks();
9656 /* Restore the "this" pointer. */
9659 cp_function_chain->x_current_class_ptr = saved_class_ptr;
9660 cp_function_chain->x_current_class_ref = saved_class_ref;
9663 /* Make sure the default argument is reasonable. */
9664 arg = check_default_argument (type, arg);
9666 pop_access_scope (fn);
9671 /* Substitute into all the default arguments for FN. */
9674 tsubst_default_arguments (tree fn)
9679 tmpl_args = DECL_TI_ARGS (fn);
9681 /* If this function is not yet instantiated, we certainly don't need
9682 its default arguments. */
9683 if (uses_template_parms (tmpl_args))
9685 /* Don't do this again for clones. */
9686 if (DECL_CLONED_FUNCTION_P (fn))
9689 for (arg = TYPE_ARG_TYPES (TREE_TYPE (fn));
9691 arg = TREE_CHAIN (arg))
9692 if (TREE_PURPOSE (arg))
9693 TREE_PURPOSE (arg) = tsubst_default_argument (fn,
9695 TREE_PURPOSE (arg));
9698 /* Substitute the ARGS into the T, which is a _DECL. Return the
9699 result of the substitution. Issue error and warning messages under
9700 control of COMPLAIN. */
9703 tsubst_decl (tree t, tree args, tsubst_flags_t complain)
9705 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
9706 location_t saved_loc;
9711 /* Set the filename and linenumber to improve error-reporting. */
9712 saved_loc = input_location;
9713 input_location = DECL_SOURCE_LOCATION (t);
9715 switch (TREE_CODE (t))
9719 /* We can get here when processing a member function template,
9720 member class template, or template template parameter. */
9721 tree decl = DECL_TEMPLATE_RESULT (t);
9726 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
9728 /* Template template parameter is treated here. */
9729 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9730 if (new_type == error_mark_node)
9731 RETURN (error_mark_node);
9734 DECL_CHAIN (r) = NULL_TREE;
9735 TREE_TYPE (r) = new_type;
9736 DECL_TEMPLATE_RESULT (r)
9737 = build_decl (DECL_SOURCE_LOCATION (decl),
9738 TYPE_DECL, DECL_NAME (decl), new_type);
9739 DECL_TEMPLATE_PARMS (r)
9740 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
9742 TYPE_NAME (new_type) = r;
9746 /* We might already have an instance of this template.
9747 The ARGS are for the surrounding class type, so the
9748 full args contain the tsubst'd args for the context,
9749 plus the innermost args from the template decl. */
9750 tmpl_args = DECL_CLASS_TEMPLATE_P (t)
9751 ? CLASSTYPE_TI_ARGS (TREE_TYPE (t))
9752 : DECL_TI_ARGS (DECL_TEMPLATE_RESULT (t));
9753 /* Because this is a template, the arguments will still be
9754 dependent, even after substitution. If
9755 PROCESSING_TEMPLATE_DECL is not set, the dependency
9756 predicates will short-circuit. */
9757 ++processing_template_decl;
9758 full_args = tsubst_template_args (tmpl_args, args,
9760 --processing_template_decl;
9761 if (full_args == error_mark_node)
9762 RETURN (error_mark_node);
9764 /* If this is a default template template argument,
9765 tsubst might not have changed anything. */
9766 if (full_args == tmpl_args)
9769 hash = hash_tmpl_and_args (t, full_args);
9770 spec = retrieve_specialization (t, full_args, hash);
9771 if (spec != NULL_TREE)
9777 /* Make a new template decl. It will be similar to the
9778 original, but will record the current template arguments.
9779 We also create a new function declaration, which is just
9780 like the old one, but points to this new template, rather
9781 than the old one. */
9783 gcc_assert (DECL_LANG_SPECIFIC (r) != 0);
9784 DECL_CHAIN (r) = NULL_TREE;
9786 DECL_TEMPLATE_INFO (r) = build_template_info (t, args);
9788 if (TREE_CODE (decl) == TYPE_DECL)
9791 ++processing_template_decl;
9792 new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9793 --processing_template_decl;
9794 if (new_type == error_mark_node)
9795 RETURN (error_mark_node);
9797 TREE_TYPE (r) = new_type;
9798 CLASSTYPE_TI_TEMPLATE (new_type) = r;
9799 DECL_TEMPLATE_RESULT (r) = TYPE_MAIN_DECL (new_type);
9800 DECL_TI_ARGS (r) = CLASSTYPE_TI_ARGS (new_type);
9801 DECL_CONTEXT (r) = TYPE_CONTEXT (new_type);
9806 ++processing_template_decl;
9807 new_decl = tsubst (decl, args, complain, in_decl);
9808 --processing_template_decl;
9809 if (new_decl == error_mark_node)
9810 RETURN (error_mark_node);
9812 DECL_TEMPLATE_RESULT (r) = new_decl;
9813 DECL_TI_TEMPLATE (new_decl) = r;
9814 TREE_TYPE (r) = TREE_TYPE (new_decl);
9815 DECL_TI_ARGS (r) = DECL_TI_ARGS (new_decl);
9816 DECL_CONTEXT (r) = DECL_CONTEXT (new_decl);
9819 SET_DECL_IMPLICIT_INSTANTIATION (r);
9820 DECL_TEMPLATE_INSTANTIATIONS (r) = NULL_TREE;
9821 DECL_TEMPLATE_SPECIALIZATIONS (r) = NULL_TREE;
9823 /* The template parameters for this new template are all the
9824 template parameters for the old template, except the
9825 outermost level of parameters. */
9826 DECL_TEMPLATE_PARMS (r)
9827 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
9830 if (PRIMARY_TEMPLATE_P (t))
9831 DECL_PRIMARY_TEMPLATE (r) = r;
9833 if (TREE_CODE (decl) != TYPE_DECL)
9834 /* Record this non-type partial instantiation. */
9835 register_specialization (r, t,
9836 DECL_TI_ARGS (DECL_TEMPLATE_RESULT (r)),
9844 tree argvec = NULL_TREE;
9852 /* Nobody should be tsubst'ing into non-template functions. */
9853 gcc_assert (DECL_TEMPLATE_INFO (t) != NULL_TREE);
9855 if (TREE_CODE (DECL_TI_TEMPLATE (t)) == TEMPLATE_DECL)
9860 /* If T is not dependent, just return it. We have to
9861 increment PROCESSING_TEMPLATE_DECL because
9862 value_dependent_expression_p assumes that nothing is
9863 dependent when PROCESSING_TEMPLATE_DECL is zero. */
9864 ++processing_template_decl;
9865 dependent_p = value_dependent_expression_p (t);
9866 --processing_template_decl;
9870 /* Calculate the most general template of which R is a
9871 specialization, and the complete set of arguments used to
9873 gen_tmpl = most_general_template (DECL_TI_TEMPLATE (t));
9874 argvec = tsubst_template_args (DECL_TI_ARGS
9875 (DECL_TEMPLATE_RESULT
9876 (DECL_TI_TEMPLATE (t))),
9877 args, complain, in_decl);
9878 if (argvec == error_mark_node)
9879 RETURN (error_mark_node);
9881 /* Check to see if we already have this specialization. */
9882 hash = hash_tmpl_and_args (gen_tmpl, argvec);
9883 spec = retrieve_specialization (gen_tmpl, argvec, hash);
9891 /* We can see more levels of arguments than parameters if
9892 there was a specialization of a member template, like
9895 template <class T> struct S { template <class U> void f(); }
9896 template <> template <class U> void S<int>::f(U);
9898 Here, we'll be substituting into the specialization,
9899 because that's where we can find the code we actually
9900 want to generate, but we'll have enough arguments for
9901 the most general template.
9903 We also deal with the peculiar case:
9905 template <class T> struct S {
9906 template <class U> friend void f();
9908 template <class U> void f() {}
9910 template void f<double>();
9912 Here, the ARGS for the instantiation of will be {int,
9913 double}. But, we only need as many ARGS as there are
9914 levels of template parameters in CODE_PATTERN. We are
9915 careful not to get fooled into reducing the ARGS in
9918 template <class T> struct S { template <class U> void f(U); }
9919 template <class T> template <> void S<T>::f(int) {}
9921 which we can spot because the pattern will be a
9922 specialization in this case. */
9923 args_depth = TMPL_ARGS_DEPTH (args);
9925 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (t)));
9926 if (args_depth > parms_depth
9927 && !DECL_TEMPLATE_SPECIALIZATION (t))
9928 args = get_innermost_template_args (args, parms_depth);
9932 /* This special case arises when we have something like this:
9934 template <class T> struct S {
9935 friend void f<int>(int, double);
9938 Here, the DECL_TI_TEMPLATE for the friend declaration
9939 will be an IDENTIFIER_NODE. We are being called from
9940 tsubst_friend_function, and we want only to create a
9941 new decl (R) with appropriate types so that we can call
9942 determine_specialization. */
9943 gen_tmpl = NULL_TREE;
9946 if (DECL_CLASS_SCOPE_P (t))
9948 if (DECL_NAME (t) == constructor_name (DECL_CONTEXT (t)))
9952 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args,
9953 complain, t, /*entering_scope=*/1);
9958 ctx = DECL_CONTEXT (t);
9960 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9961 if (type == error_mark_node)
9962 RETURN (error_mark_node);
9964 /* We do NOT check for matching decls pushed separately at this
9965 point, as they may not represent instantiations of this
9966 template, and in any case are considered separate under the
9969 DECL_USE_TEMPLATE (r) = 0;
9970 TREE_TYPE (r) = type;
9971 /* Clear out the mangled name and RTL for the instantiation. */
9972 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
9973 SET_DECL_RTL (r, NULL);
9974 /* Leave DECL_INITIAL set on deleted instantiations. */
9975 if (!DECL_DELETED_FN (r))
9976 DECL_INITIAL (r) = NULL_TREE;
9977 DECL_CONTEXT (r) = ctx;
9979 if (member && DECL_CONV_FN_P (r))
9980 /* Type-conversion operator. Reconstruct the name, in
9981 case it's the name of one of the template's parameters. */
9982 DECL_NAME (r) = mangle_conv_op_name_for_type (TREE_TYPE (type));
9984 DECL_ARGUMENTS (r) = tsubst (DECL_ARGUMENTS (t), args,
9986 DECL_RESULT (r) = NULL_TREE;
9988 TREE_STATIC (r) = 0;
9989 TREE_PUBLIC (r) = TREE_PUBLIC (t);
9990 DECL_EXTERNAL (r) = 1;
9991 /* If this is an instantiation of a function with internal
9992 linkage, we already know what object file linkage will be
9993 assigned to the instantiation. */
9994 DECL_INTERFACE_KNOWN (r) = !TREE_PUBLIC (r);
9995 DECL_DEFER_OUTPUT (r) = 0;
9996 DECL_CHAIN (r) = NULL_TREE;
9997 DECL_PENDING_INLINE_INFO (r) = 0;
9998 DECL_PENDING_INLINE_P (r) = 0;
9999 DECL_SAVED_TREE (r) = NULL_TREE;
10000 DECL_STRUCT_FUNCTION (r) = NULL;
10002 /* We'll re-clone as appropriate in instantiate_template. */
10003 DECL_CLONED_FUNCTION (r) = NULL_TREE;
10005 /* If we aren't complaining now, return on error before we register
10006 the specialization so that we'll complain eventually. */
10007 if ((complain & tf_error) == 0
10008 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
10009 && !grok_op_properties (r, /*complain=*/false))
10010 RETURN (error_mark_node);
10012 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
10013 this in the special friend case mentioned above where
10014 GEN_TMPL is NULL. */
10017 DECL_TEMPLATE_INFO (r)
10018 = build_template_info (gen_tmpl, argvec);
10019 SET_DECL_IMPLICIT_INSTANTIATION (r);
10020 register_specialization (r, gen_tmpl, argvec, false, hash);
10022 /* We're not supposed to instantiate default arguments
10023 until they are called, for a template. But, for a
10026 template <class T> void f ()
10027 { extern void g(int i = T()); }
10029 we should do the substitution when the template is
10030 instantiated. We handle the member function case in
10031 instantiate_class_template since the default arguments
10032 might refer to other members of the class. */
10034 && !PRIMARY_TEMPLATE_P (gen_tmpl)
10035 && !uses_template_parms (argvec))
10036 tsubst_default_arguments (r);
10039 DECL_TEMPLATE_INFO (r) = NULL_TREE;
10041 /* Copy the list of befriending classes. */
10042 for (friends = &DECL_BEFRIENDING_CLASSES (r);
10044 friends = &TREE_CHAIN (*friends))
10046 *friends = copy_node (*friends);
10047 TREE_VALUE (*friends) = tsubst (TREE_VALUE (*friends),
10052 if (DECL_CONSTRUCTOR_P (r) || DECL_DESTRUCTOR_P (r))
10054 maybe_retrofit_in_chrg (r);
10055 if (DECL_CONSTRUCTOR_P (r))
10056 grok_ctor_properties (ctx, r);
10057 /* If this is an instantiation of a member template, clone it.
10058 If it isn't, that'll be handled by
10059 clone_constructors_and_destructors. */
10060 if (PRIMARY_TEMPLATE_P (gen_tmpl))
10061 clone_function_decl (r, /*update_method_vec_p=*/0);
10063 else if ((complain & tf_error) != 0
10064 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
10065 && !grok_op_properties (r, /*complain=*/true))
10066 RETURN (error_mark_node);
10068 if (DECL_FRIEND_P (t) && DECL_FRIEND_CONTEXT (t))
10069 SET_DECL_FRIEND_CONTEXT (r,
10070 tsubst (DECL_FRIEND_CONTEXT (t),
10071 args, complain, in_decl));
10073 /* Possibly limit visibility based on template args. */
10074 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
10075 if (DECL_VISIBILITY_SPECIFIED (t))
10077 DECL_VISIBILITY_SPECIFIED (r) = 0;
10078 DECL_ATTRIBUTES (r)
10079 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
10081 determine_visibility (r);
10082 if (DECL_DEFAULTED_OUTSIDE_CLASS_P (r)
10083 && !processing_template_decl)
10084 defaulted_late_check (r);
10086 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
10087 args, complain, in_decl);
10093 tree type = NULL_TREE;
10095 tree expanded_types = NULL_TREE;
10096 tree prev_r = NULL_TREE;
10097 tree first_r = NULL_TREE;
10099 if (FUNCTION_PARAMETER_PACK_P (t))
10101 /* If there is a local specialization that isn't a
10102 parameter pack, it means that we're doing a "simple"
10103 substitution from inside tsubst_pack_expansion. Just
10104 return the local specialization (which will be a single
10106 tree spec = retrieve_local_specialization (t);
10108 && TREE_CODE (spec) == PARM_DECL
10109 && TREE_CODE (TREE_TYPE (spec)) != TYPE_PACK_EXPANSION)
10112 /* Expand the TYPE_PACK_EXPANSION that provides the types for
10113 the parameters in this function parameter pack. */
10114 expanded_types = tsubst_pack_expansion (TREE_TYPE (t), args,
10115 complain, in_decl);
10116 if (TREE_CODE (expanded_types) == TREE_VEC)
10118 len = TREE_VEC_LENGTH (expanded_types);
10120 /* Zero-length parameter packs are boring. Just substitute
10123 RETURN (tsubst (TREE_CHAIN (t), args, complain,
10128 /* All we did was update the type. Make a note of that. */
10129 type = expanded_types;
10130 expanded_types = NULL_TREE;
10134 /* Loop through all of the parameter's we'll build. When T is
10135 a function parameter pack, LEN is the number of expanded
10136 types in EXPANDED_TYPES; otherwise, LEN is 1. */
10138 for (i = 0; i < len; ++i)
10142 if (DECL_TEMPLATE_PARM_P (t))
10143 SET_DECL_TEMPLATE_PARM_P (r);
10145 if (expanded_types)
10146 /* We're on the Ith parameter of the function parameter
10149 /* An argument of a function parameter pack is not a parameter
10151 FUNCTION_PARAMETER_PACK_P (r) = false;
10153 /* Get the Ith type. */
10154 type = TREE_VEC_ELT (expanded_types, i);
10157 /* Rename the parameter to include the index. */
10159 make_ith_pack_parameter_name (DECL_NAME (r), i);
10162 /* We're dealing with a normal parameter. */
10163 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10165 type = type_decays_to (type);
10166 TREE_TYPE (r) = type;
10167 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
10169 if (DECL_INITIAL (r))
10171 if (TREE_CODE (DECL_INITIAL (r)) != TEMPLATE_PARM_INDEX)
10172 DECL_INITIAL (r) = TREE_TYPE (r);
10174 DECL_INITIAL (r) = tsubst (DECL_INITIAL (r), args,
10175 complain, in_decl);
10178 DECL_CONTEXT (r) = NULL_TREE;
10180 if (!DECL_TEMPLATE_PARM_P (r))
10181 DECL_ARG_TYPE (r) = type_passed_as (type);
10183 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
10184 args, complain, in_decl);
10186 /* Keep track of the first new parameter we
10187 generate. That's what will be returned to the
10192 /* Build a proper chain of parameters when substituting
10193 into a function parameter pack. */
10195 DECL_CHAIN (prev_r) = r;
10198 if (DECL_CHAIN (t))
10199 DECL_CHAIN (r) = tsubst (DECL_CHAIN (t), args,
10200 complain, DECL_CHAIN (t));
10202 /* FIRST_R contains the start of the chain we've built. */
10212 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10213 if (type == error_mark_node)
10214 RETURN (error_mark_node);
10215 TREE_TYPE (r) = type;
10216 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
10218 /* DECL_INITIAL gives the number of bits in a bit-field. */
10220 = tsubst_expr (DECL_INITIAL (t), args,
10222 /*integral_constant_expression_p=*/true);
10223 /* We don't have to set DECL_CONTEXT here; it is set by
10224 finish_member_declaration. */
10225 DECL_CHAIN (r) = NULL_TREE;
10226 if (VOID_TYPE_P (type))
10227 error ("instantiation of %q+D as type %qT", r, type);
10229 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
10230 args, complain, in_decl);
10235 /* We reach here only for member using decls. */
10236 if (DECL_DEPENDENT_P (t))
10238 r = do_class_using_decl
10239 (tsubst_copy (USING_DECL_SCOPE (t), args, complain, in_decl),
10240 tsubst_copy (DECL_NAME (t), args, complain, in_decl));
10242 r = error_mark_node;
10245 TREE_PROTECTED (r) = TREE_PROTECTED (t);
10246 TREE_PRIVATE (r) = TREE_PRIVATE (t);
10252 DECL_CHAIN (r) = NULL_TREE;
10259 tree argvec = NULL_TREE;
10260 tree gen_tmpl = NULL_TREE;
10262 tree tmpl = NULL_TREE;
10264 tree type = NULL_TREE;
10267 if (TREE_CODE (t) == TYPE_DECL
10268 && t == TYPE_MAIN_DECL (TREE_TYPE (t)))
10270 /* If this is the canonical decl, we don't have to
10271 mess with instantiations, and often we can't (for
10272 typename, template type parms and such). Note that
10273 TYPE_NAME is not correct for the above test if
10274 we've copied the type for a typedef. */
10275 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10276 if (type == error_mark_node)
10277 RETURN (error_mark_node);
10278 r = TYPE_NAME (type);
10282 /* Check to see if we already have the specialization we
10285 if (DECL_CLASS_SCOPE_P (t) || DECL_NAMESPACE_SCOPE_P (t))
10287 /* T is a static data member or namespace-scope entity.
10288 We have to substitute into namespace-scope variables
10289 (even though such entities are never templates) because
10292 template <class T> void f() { extern T t; }
10294 where the entity referenced is not known until
10295 instantiation time. */
10297 ctx = DECL_CONTEXT (t);
10298 if (DECL_CLASS_SCOPE_P (t))
10300 ctx = tsubst_aggr_type (ctx, args,
10302 in_decl, /*entering_scope=*/1);
10303 /* If CTX is unchanged, then T is in fact the
10304 specialization we want. That situation occurs when
10305 referencing a static data member within in its own
10306 class. We can use pointer equality, rather than
10307 same_type_p, because DECL_CONTEXT is always
10309 if (ctx == DECL_CONTEXT (t))
10315 tmpl = DECL_TI_TEMPLATE (t);
10316 gen_tmpl = most_general_template (tmpl);
10317 argvec = tsubst (DECL_TI_ARGS (t), args, complain, in_decl);
10318 hash = hash_tmpl_and_args (gen_tmpl, argvec);
10319 spec = retrieve_specialization (gen_tmpl, argvec, hash);
10324 /* A local variable. */
10326 /* Subsequent calls to pushdecl will fill this in. */
10328 spec = retrieve_local_specialization (t);
10330 /* If we already have the specialization we need, there is
10331 nothing more to do. */
10338 /* Create a new node for the specialization we need. */
10340 if (type == NULL_TREE)
10342 if (is_typedef_decl (t))
10343 type = DECL_ORIGINAL_TYPE (t);
10345 type = TREE_TYPE (t);
10346 if (TREE_CODE (t) == VAR_DECL && VAR_HAD_UNKNOWN_BOUND (t))
10347 type = strip_array_domain (type);
10348 type = tsubst (type, args, complain, in_decl);
10350 if (TREE_CODE (r) == VAR_DECL)
10352 /* Even if the original location is out of scope, the
10353 newly substituted one is not. */
10354 DECL_DEAD_FOR_LOCAL (r) = 0;
10355 DECL_INITIALIZED_P (r) = 0;
10356 DECL_TEMPLATE_INSTANTIATED (r) = 0;
10357 if (type == error_mark_node)
10358 RETURN (error_mark_node);
10359 if (TREE_CODE (type) == FUNCTION_TYPE)
10361 /* It may seem that this case cannot occur, since:
10366 declares a function, not a variable. However:
10369 template <typename T> void g() { T t; }
10370 template void g<f>();
10372 is an attempt to declare a variable with function
10374 error ("variable %qD has function type",
10375 /* R is not yet sufficiently initialized, so we
10376 just use its name. */
10378 RETURN (error_mark_node);
10380 type = complete_type (type);
10381 /* Wait until cp_finish_decl to set this again, to handle
10382 circular dependency (template/instantiate6.C). */
10383 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r) = 0;
10384 type = check_var_type (DECL_NAME (r), type);
10386 if (DECL_HAS_VALUE_EXPR_P (t))
10388 tree ve = DECL_VALUE_EXPR (t);
10389 ve = tsubst_expr (ve, args, complain, in_decl,
10390 /*constant_expression_p=*/false);
10391 if (REFERENCE_REF_P (ve))
10393 gcc_assert (TREE_CODE (type) == REFERENCE_TYPE);
10394 ve = TREE_OPERAND (ve, 0);
10396 SET_DECL_VALUE_EXPR (r, ve);
10399 else if (DECL_SELF_REFERENCE_P (t))
10400 SET_DECL_SELF_REFERENCE_P (r);
10401 TREE_TYPE (r) = type;
10402 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
10403 DECL_CONTEXT (r) = ctx;
10404 /* Clear out the mangled name and RTL for the instantiation. */
10405 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
10406 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
10407 SET_DECL_RTL (r, NULL);
10408 /* The initializer must not be expanded until it is required;
10409 see [temp.inst]. */
10410 DECL_INITIAL (r) = NULL_TREE;
10411 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
10412 SET_DECL_RTL (r, NULL);
10413 DECL_SIZE (r) = DECL_SIZE_UNIT (r) = 0;
10414 if (TREE_CODE (r) == VAR_DECL)
10416 /* Possibly limit visibility based on template args. */
10417 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
10418 if (DECL_VISIBILITY_SPECIFIED (t))
10420 DECL_VISIBILITY_SPECIFIED (r) = 0;
10421 DECL_ATTRIBUTES (r)
10422 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
10424 determine_visibility (r);
10429 /* A static data member declaration is always marked
10430 external when it is declared in-class, even if an
10431 initializer is present. We mimic the non-template
10432 processing here. */
10433 DECL_EXTERNAL (r) = 1;
10435 register_specialization (r, gen_tmpl, argvec, false, hash);
10436 DECL_TEMPLATE_INFO (r) = build_template_info (tmpl, argvec);
10437 SET_DECL_IMPLICIT_INSTANTIATION (r);
10439 else if (cp_unevaluated_operand)
10441 /* We're substituting this var in a decltype outside of its
10442 scope, such as for a lambda return type. Don't add it to
10443 local_specializations, do perform auto deduction. */
10444 tree auto_node = type_uses_auto (type);
10448 = tsubst_expr (DECL_INITIAL (t), args, complain, in_decl,
10449 /*constant_expression_p=*/false);
10450 init = resolve_nondeduced_context (init);
10451 TREE_TYPE (r) = type
10452 = do_auto_deduction (type, init, auto_node);
10456 register_local_specialization (r, t);
10458 DECL_CHAIN (r) = NULL_TREE;
10460 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r),
10462 args, complain, in_decl);
10464 /* Preserve a typedef that names a type. */
10465 if (is_typedef_decl (r))
10467 DECL_ORIGINAL_TYPE (r) = NULL_TREE;
10468 set_underlying_type (r);
10471 layout_decl (r, 0);
10476 gcc_unreachable ();
10481 /* Restore the file and line information. */
10482 input_location = saved_loc;
10487 /* Substitute into the ARG_TYPES of a function type. */
10490 tsubst_arg_types (tree arg_types,
10492 tsubst_flags_t complain,
10495 tree remaining_arg_types;
10496 tree type = NULL_TREE;
10498 tree expanded_args = NULL_TREE;
10501 if (!arg_types || arg_types == void_list_node)
10504 remaining_arg_types = tsubst_arg_types (TREE_CHAIN (arg_types),
10505 args, complain, in_decl);
10506 if (remaining_arg_types == error_mark_node)
10507 return error_mark_node;
10509 if (PACK_EXPANSION_P (TREE_VALUE (arg_types)))
10511 /* For a pack expansion, perform substitution on the
10512 entire expression. Later on, we'll handle the arguments
10514 expanded_args = tsubst_pack_expansion (TREE_VALUE (arg_types),
10515 args, complain, in_decl);
10517 if (TREE_CODE (expanded_args) == TREE_VEC)
10518 /* So that we'll spin through the parameters, one by one. */
10519 i = TREE_VEC_LENGTH (expanded_args);
10522 /* We only partially substituted into the parameter
10523 pack. Our type is TYPE_PACK_EXPANSION. */
10524 type = expanded_args;
10525 expanded_args = NULL_TREE;
10533 type = TREE_VEC_ELT (expanded_args, i);
10535 type = tsubst (TREE_VALUE (arg_types), args, complain, in_decl);
10537 if (type == error_mark_node)
10538 return error_mark_node;
10539 if (VOID_TYPE_P (type))
10541 if (complain & tf_error)
10543 error ("invalid parameter type %qT", type);
10545 error ("in declaration %q+D", in_decl);
10547 return error_mark_node;
10550 /* Do array-to-pointer, function-to-pointer conversion, and ignore
10551 top-level qualifiers as required. */
10552 type = cv_unqualified (type_decays_to (type));
10554 /* We do not substitute into default arguments here. The standard
10555 mandates that they be instantiated only when needed, which is
10556 done in build_over_call. */
10557 default_arg = TREE_PURPOSE (arg_types);
10559 if (default_arg && TREE_CODE (default_arg) == DEFAULT_ARG)
10561 /* We've instantiated a template before its default arguments
10562 have been parsed. This can happen for a nested template
10563 class, and is not an error unless we require the default
10564 argument in a call of this function. */
10565 remaining_arg_types =
10566 tree_cons (default_arg, type, remaining_arg_types);
10567 VEC_safe_push (tree, gc, DEFARG_INSTANTIATIONS (default_arg),
10568 remaining_arg_types);
10571 remaining_arg_types =
10572 hash_tree_cons (default_arg, type, remaining_arg_types);
10575 return remaining_arg_types;
10578 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
10579 *not* handle the exception-specification for FNTYPE, because the
10580 initial substitution of explicitly provided template parameters
10581 during argument deduction forbids substitution into the
10582 exception-specification:
10586 All references in the function type of the function template to the
10587 corresponding template parameters are replaced by the specified tem-
10588 plate argument values. If a substitution in a template parameter or
10589 in the function type of the function template results in an invalid
10590 type, type deduction fails. [Note: The equivalent substitution in
10591 exception specifications is done only when the function is instanti-
10592 ated, at which point a program is ill-formed if the substitution
10593 results in an invalid type.] */
10596 tsubst_function_type (tree t,
10598 tsubst_flags_t complain,
10605 /* The TYPE_CONTEXT is not used for function/method types. */
10606 gcc_assert (TYPE_CONTEXT (t) == NULL_TREE);
10608 /* Substitute the return type. */
10609 return_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10610 if (return_type == error_mark_node)
10611 return error_mark_node;
10612 /* The standard does not presently indicate that creation of a
10613 function type with an invalid return type is a deduction failure.
10614 However, that is clearly analogous to creating an array of "void"
10615 or a reference to a reference. This is core issue #486. */
10616 if (TREE_CODE (return_type) == ARRAY_TYPE
10617 || TREE_CODE (return_type) == FUNCTION_TYPE)
10619 if (complain & tf_error)
10621 if (TREE_CODE (return_type) == ARRAY_TYPE)
10622 error ("function returning an array");
10624 error ("function returning a function");
10626 return error_mark_node;
10629 /* Substitute the argument types. */
10630 arg_types = tsubst_arg_types (TYPE_ARG_TYPES (t), args,
10631 complain, in_decl);
10632 if (arg_types == error_mark_node)
10633 return error_mark_node;
10635 /* Construct a new type node and return it. */
10636 if (TREE_CODE (t) == FUNCTION_TYPE)
10638 fntype = build_function_type (return_type, arg_types);
10639 fntype = apply_memfn_quals (fntype, type_memfn_quals (t));
10643 tree r = TREE_TYPE (TREE_VALUE (arg_types));
10644 if (! MAYBE_CLASS_TYPE_P (r))
10648 Type deduction may fail for any of the following
10651 -- Attempting to create "pointer to member of T" when T
10652 is not a class type. */
10653 if (complain & tf_error)
10654 error ("creating pointer to member function of non-class type %qT",
10656 return error_mark_node;
10659 fntype = build_method_type_directly (r, return_type,
10660 TREE_CHAIN (arg_types));
10662 fntype = cp_build_type_attribute_variant (fntype, TYPE_ATTRIBUTES (t));
10667 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
10668 ARGS into that specification, and return the substituted
10669 specification. If there is no specification, return NULL_TREE. */
10672 tsubst_exception_specification (tree fntype,
10674 tsubst_flags_t complain,
10681 specs = TYPE_RAISES_EXCEPTIONS (fntype);
10682 new_specs = NULL_TREE;
10683 if (specs && TREE_PURPOSE (specs))
10685 /* A noexcept-specifier. */
10686 tree expr = TREE_PURPOSE (specs);
10687 if (expr == boolean_true_node || expr == boolean_false_node)
10691 /* Defer instantiation of noexcept-specifiers to avoid
10692 excessive instantiations (c++/49107). */
10693 new_specs = make_node (DEFERRED_NOEXCEPT);
10694 if (DEFERRED_NOEXCEPT_SPEC_P (specs))
10696 /* We already partially instantiated this member template,
10697 so combine the new args with the old. */
10698 DEFERRED_NOEXCEPT_PATTERN (new_specs)
10699 = DEFERRED_NOEXCEPT_PATTERN (expr);
10700 DEFERRED_NOEXCEPT_ARGS (new_specs)
10701 = add_to_template_args (DEFERRED_NOEXCEPT_ARGS (expr), args);
10705 DEFERRED_NOEXCEPT_PATTERN (new_specs) = expr;
10706 DEFERRED_NOEXCEPT_ARGS (new_specs) = args;
10710 new_specs = tsubst_copy_and_build
10711 (expr, args, complain, in_decl, /*function_p=*/false,
10712 /*integral_constant_expression_p=*/true);
10713 new_specs = build_noexcept_spec (new_specs, complain);
10717 if (! TREE_VALUE (specs))
10724 tree expanded_specs = NULL_TREE;
10726 if (PACK_EXPANSION_P (TREE_VALUE (specs)))
10728 /* Expand the pack expansion type. */
10729 expanded_specs = tsubst_pack_expansion (TREE_VALUE (specs),
10733 if (expanded_specs == error_mark_node)
10734 return error_mark_node;
10735 else if (TREE_CODE (expanded_specs) == TREE_VEC)
10736 len = TREE_VEC_LENGTH (expanded_specs);
10739 /* We're substituting into a member template, so
10740 we got a TYPE_PACK_EXPANSION back. Add that
10741 expansion and move on. */
10742 gcc_assert (TREE_CODE (expanded_specs)
10743 == TYPE_PACK_EXPANSION);
10744 new_specs = add_exception_specifier (new_specs,
10747 specs = TREE_CHAIN (specs);
10752 for (i = 0; i < len; ++i)
10754 if (expanded_specs)
10755 spec = TREE_VEC_ELT (expanded_specs, i);
10757 spec = tsubst (TREE_VALUE (specs), args, complain, in_decl);
10758 if (spec == error_mark_node)
10760 new_specs = add_exception_specifier (new_specs, spec,
10764 specs = TREE_CHAIN (specs);
10770 /* Take the tree structure T and replace template parameters used
10771 therein with the argument vector ARGS. IN_DECL is an associated
10772 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
10773 Issue error and warning messages under control of COMPLAIN. Note
10774 that we must be relatively non-tolerant of extensions here, in
10775 order to preserve conformance; if we allow substitutions that
10776 should not be allowed, we may allow argument deductions that should
10777 not succeed, and therefore report ambiguous overload situations
10778 where there are none. In theory, we could allow the substitution,
10779 but indicate that it should have failed, and allow our caller to
10780 make sure that the right thing happens, but we don't try to do this
10783 This function is used for dealing with types, decls and the like;
10784 for expressions, use tsubst_expr or tsubst_copy. */
10787 tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl)
10789 enum tree_code code;
10792 if (t == NULL_TREE || t == error_mark_node
10793 || t == integer_type_node
10794 || t == void_type_node
10795 || t == char_type_node
10796 || t == unknown_type_node
10797 || TREE_CODE (t) == NAMESPACE_DECL
10798 || TREE_CODE (t) == TRANSLATION_UNIT_DECL)
10802 return tsubst_decl (t, args, complain);
10804 if (args == NULL_TREE)
10807 code = TREE_CODE (t);
10809 if (code == IDENTIFIER_NODE)
10810 type = IDENTIFIER_TYPE_VALUE (t);
10812 type = TREE_TYPE (t);
10814 gcc_assert (type != unknown_type_node);
10816 /* Reuse typedefs. We need to do this to handle dependent attributes,
10817 such as attribute aligned. */
10819 && typedef_variant_p (t))
10821 tree decl = TYPE_NAME (t);
10823 if (DECL_CLASS_SCOPE_P (decl)
10824 && CLASSTYPE_TEMPLATE_INFO (DECL_CONTEXT (decl))
10825 && uses_template_parms (DECL_CONTEXT (decl)))
10827 tree tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
10828 tree gen_args = tsubst (DECL_TI_ARGS (decl), args, complain, in_decl);
10829 r = retrieve_specialization (tmpl, gen_args, 0);
10831 else if (DECL_FUNCTION_SCOPE_P (decl)
10832 && DECL_TEMPLATE_INFO (DECL_CONTEXT (decl))
10833 && uses_template_parms (DECL_TI_ARGS (DECL_CONTEXT (decl))))
10834 r = retrieve_local_specialization (decl);
10836 /* The typedef is from a non-template context. */
10842 r = cp_build_qualified_type_real
10843 (r, cp_type_quals (t) | cp_type_quals (r),
10844 complain | tf_ignore_bad_quals);
10847 /* Else we must be instantiating the typedef, so fall through. */
10851 && code != TYPENAME_TYPE
10852 && code != TEMPLATE_TYPE_PARM
10853 && code != IDENTIFIER_NODE
10854 && code != FUNCTION_TYPE
10855 && code != METHOD_TYPE)
10856 type = tsubst (type, args, complain, in_decl);
10857 if (type == error_mark_node)
10858 return error_mark_node;
10864 case ENUMERAL_TYPE:
10865 return tsubst_aggr_type (t, args, complain, in_decl,
10866 /*entering_scope=*/0);
10869 case IDENTIFIER_NODE:
10880 if (t == integer_type_node)
10883 if (TREE_CODE (TYPE_MIN_VALUE (t)) == INTEGER_CST
10884 && TREE_CODE (TYPE_MAX_VALUE (t)) == INTEGER_CST)
10888 tree max, omax = TREE_OPERAND (TYPE_MAX_VALUE (t), 0);
10890 max = tsubst_expr (omax, args, complain, in_decl,
10891 /*integral_constant_expression_p=*/false);
10893 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
10895 if (TREE_CODE (max) == NOP_EXPR
10896 && TREE_SIDE_EFFECTS (omax)
10897 && !TREE_TYPE (max))
10898 TREE_TYPE (max) = TREE_TYPE (TREE_OPERAND (max, 0));
10900 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
10901 with TREE_SIDE_EFFECTS that indicates this is not an integral
10902 constant expression. */
10903 if (processing_template_decl
10904 && TREE_SIDE_EFFECTS (omax) && TREE_CODE (omax) == NOP_EXPR)
10906 gcc_assert (TREE_CODE (max) == NOP_EXPR);
10907 TREE_SIDE_EFFECTS (max) = 1;
10910 return compute_array_index_type (NULL_TREE, max, complain);
10913 case TEMPLATE_TYPE_PARM:
10914 case TEMPLATE_TEMPLATE_PARM:
10915 case BOUND_TEMPLATE_TEMPLATE_PARM:
10916 case TEMPLATE_PARM_INDEX:
10921 tree arg = NULL_TREE;
10925 gcc_assert (TREE_VEC_LENGTH (args) > 0);
10926 template_parm_level_and_index (t, &level, &idx);
10928 levels = TMPL_ARGS_DEPTH (args);
10929 if (level <= levels)
10931 arg = TMPL_ARG (args, level, idx);
10933 if (arg && TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
10934 /* See through ARGUMENT_PACK_SELECT arguments. */
10935 arg = ARGUMENT_PACK_SELECT_ARG (arg);
10938 if (arg == error_mark_node)
10939 return error_mark_node;
10940 else if (arg != NULL_TREE)
10942 if (ARGUMENT_PACK_P (arg))
10943 /* If ARG is an argument pack, we don't actually want to
10944 perform a substitution here, because substitutions
10945 for argument packs are only done
10946 element-by-element. We can get to this point when
10947 substituting the type of a non-type template
10948 parameter pack, when that type actually contains
10949 template parameter packs from an outer template, e.g.,
10951 template<typename... Types> struct A {
10952 template<Types... Values> struct B { };
10956 if (code == TEMPLATE_TYPE_PARM)
10959 gcc_assert (TYPE_P (arg));
10961 quals = cp_type_quals (arg) | cp_type_quals (t);
10963 return cp_build_qualified_type_real
10964 (arg, quals, complain | tf_ignore_bad_quals);
10966 else if (code == BOUND_TEMPLATE_TEMPLATE_PARM)
10968 /* We are processing a type constructed from a
10969 template template parameter. */
10970 tree argvec = tsubst (TYPE_TI_ARGS (t),
10971 args, complain, in_decl);
10972 if (argvec == error_mark_node)
10973 return error_mark_node;
10975 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
10976 are resolving nested-types in the signature of a
10977 member function templates. Otherwise ARG is a
10978 TEMPLATE_DECL and is the real template to be
10980 if (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
10981 arg = TYPE_NAME (arg);
10983 r = lookup_template_class (arg,
10985 DECL_CONTEXT (arg),
10986 /*entering_scope=*/0,
10988 return cp_build_qualified_type_real
10989 (r, cp_type_quals (t), complain);
10992 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
10993 return convert_from_reference (unshare_expr (arg));
10997 /* This can happen during the attempted tsubst'ing in
10998 unify. This means that we don't yet have any information
10999 about the template parameter in question. */
11002 /* If we get here, we must have been looking at a parm for a
11003 more deeply nested template. Make a new version of this
11004 template parameter, but with a lower level. */
11007 case TEMPLATE_TYPE_PARM:
11008 case TEMPLATE_TEMPLATE_PARM:
11009 case BOUND_TEMPLATE_TEMPLATE_PARM:
11010 if (cp_type_quals (t))
11012 r = tsubst (TYPE_MAIN_VARIANT (t), args, complain, in_decl);
11013 r = cp_build_qualified_type_real
11014 (r, cp_type_quals (t),
11015 complain | (code == TEMPLATE_TYPE_PARM
11016 ? tf_ignore_bad_quals : 0));
11021 TEMPLATE_TYPE_PARM_INDEX (r)
11022 = reduce_template_parm_level (TEMPLATE_TYPE_PARM_INDEX (t),
11023 r, levels, args, complain);
11024 TYPE_STUB_DECL (r) = TYPE_NAME (r) = TEMPLATE_TYPE_DECL (r);
11025 TYPE_MAIN_VARIANT (r) = r;
11026 TYPE_POINTER_TO (r) = NULL_TREE;
11027 TYPE_REFERENCE_TO (r) = NULL_TREE;
11029 if (TREE_CODE (r) == TEMPLATE_TEMPLATE_PARM)
11030 /* We have reduced the level of the template
11031 template parameter, but not the levels of its
11032 template parameters, so canonical_type_parameter
11033 will not be able to find the canonical template
11034 template parameter for this level. Thus, we
11035 require structural equality checking to compare
11036 TEMPLATE_TEMPLATE_PARMs. */
11037 SET_TYPE_STRUCTURAL_EQUALITY (r);
11038 else if (TYPE_STRUCTURAL_EQUALITY_P (t))
11039 SET_TYPE_STRUCTURAL_EQUALITY (r);
11041 TYPE_CANONICAL (r) = canonical_type_parameter (r);
11043 if (code == BOUND_TEMPLATE_TEMPLATE_PARM)
11045 tree argvec = tsubst (TYPE_TI_ARGS (t), args,
11046 complain, in_decl);
11047 if (argvec == error_mark_node)
11048 return error_mark_node;
11050 TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (r)
11051 = build_template_info (TYPE_TI_TEMPLATE (t), argvec);
11056 case TEMPLATE_PARM_INDEX:
11057 r = reduce_template_parm_level (t, type, levels, args, complain);
11061 gcc_unreachable ();
11069 tree purpose, value, chain;
11071 if (t == void_list_node)
11074 purpose = TREE_PURPOSE (t);
11077 purpose = tsubst (purpose, args, complain, in_decl);
11078 if (purpose == error_mark_node)
11079 return error_mark_node;
11081 value = TREE_VALUE (t);
11084 value = tsubst (value, args, complain, in_decl);
11085 if (value == error_mark_node)
11086 return error_mark_node;
11088 chain = TREE_CHAIN (t);
11089 if (chain && chain != void_type_node)
11091 chain = tsubst (chain, args, complain, in_decl);
11092 if (chain == error_mark_node)
11093 return error_mark_node;
11095 if (purpose == TREE_PURPOSE (t)
11096 && value == TREE_VALUE (t)
11097 && chain == TREE_CHAIN (t))
11099 return hash_tree_cons (purpose, value, chain);
11103 /* We should never be tsubsting a binfo. */
11104 gcc_unreachable ();
11107 /* A vector of template arguments. */
11108 gcc_assert (!type);
11109 return tsubst_template_args (t, args, complain, in_decl);
11112 case REFERENCE_TYPE:
11114 if (type == TREE_TYPE (t) && TREE_CODE (type) != METHOD_TYPE)
11119 Type deduction may fail for any of the following
11122 -- Attempting to create a pointer to reference type.
11123 -- Attempting to create a reference to a reference type or
11124 a reference to void.
11126 Core issue 106 says that creating a reference to a reference
11127 during instantiation is no longer a cause for failure. We
11128 only enforce this check in strict C++98 mode. */
11129 if ((TREE_CODE (type) == REFERENCE_TYPE
11130 && (((cxx_dialect == cxx98) && flag_iso) || code != REFERENCE_TYPE))
11131 || (code == REFERENCE_TYPE && TREE_CODE (type) == VOID_TYPE))
11133 static location_t last_loc;
11135 /* We keep track of the last time we issued this error
11136 message to avoid spewing a ton of messages during a
11137 single bad template instantiation. */
11138 if (complain & tf_error
11139 && last_loc != input_location)
11141 if (TREE_CODE (type) == VOID_TYPE)
11142 error ("forming reference to void");
11143 else if (code == POINTER_TYPE)
11144 error ("forming pointer to reference type %qT", type);
11146 error ("forming reference to reference type %qT", type);
11147 last_loc = input_location;
11150 return error_mark_node;
11152 else if (code == POINTER_TYPE)
11154 r = build_pointer_type (type);
11155 if (TREE_CODE (type) == METHOD_TYPE)
11156 r = build_ptrmemfunc_type (r);
11158 else if (TREE_CODE (type) == REFERENCE_TYPE)
11159 /* In C++0x, during template argument substitution, when there is an
11160 attempt to create a reference to a reference type, reference
11161 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
11163 "If a template-argument for a template-parameter T names a type
11164 that is a reference to a type A, an attempt to create the type
11165 'lvalue reference to cv T' creates the type 'lvalue reference to
11166 A,' while an attempt to create the type type rvalue reference to
11167 cv T' creates the type T"
11169 r = cp_build_reference_type
11171 TYPE_REF_IS_RVALUE (t) && TYPE_REF_IS_RVALUE (type));
11173 r = cp_build_reference_type (type, TYPE_REF_IS_RVALUE (t));
11174 r = cp_build_qualified_type_real (r, cp_type_quals (t), complain);
11176 if (r != error_mark_node)
11177 /* Will this ever be needed for TYPE_..._TO values? */
11184 r = tsubst (TYPE_OFFSET_BASETYPE (t), args, complain, in_decl);
11185 if (r == error_mark_node || !MAYBE_CLASS_TYPE_P (r))
11189 Type deduction may fail for any of the following
11192 -- Attempting to create "pointer to member of T" when T
11193 is not a class type. */
11194 if (complain & tf_error)
11195 error ("creating pointer to member of non-class type %qT", r);
11196 return error_mark_node;
11198 if (TREE_CODE (type) == REFERENCE_TYPE)
11200 if (complain & tf_error)
11201 error ("creating pointer to member reference type %qT", type);
11202 return error_mark_node;
11204 if (TREE_CODE (type) == VOID_TYPE)
11206 if (complain & tf_error)
11207 error ("creating pointer to member of type void");
11208 return error_mark_node;
11210 gcc_assert (TREE_CODE (type) != METHOD_TYPE);
11211 if (TREE_CODE (type) == FUNCTION_TYPE)
11213 /* The type of the implicit object parameter gets its
11214 cv-qualifiers from the FUNCTION_TYPE. */
11216 tree method_type = build_memfn_type (type, r, type_memfn_quals (type));
11217 memptr = build_ptrmemfunc_type (build_pointer_type (method_type));
11218 return cp_build_qualified_type_real (memptr, cp_type_quals (t),
11222 return cp_build_qualified_type_real (build_ptrmem_type (r, type),
11226 case FUNCTION_TYPE:
11231 fntype = tsubst_function_type (t, args, complain, in_decl);
11232 if (fntype == error_mark_node)
11233 return error_mark_node;
11235 /* Substitute the exception specification. */
11236 specs = tsubst_exception_specification (t, args, complain,
11237 in_decl, /*defer_ok*/true);
11238 if (specs == error_mark_node)
11239 return error_mark_node;
11241 fntype = build_exception_variant (fntype, specs);
11246 tree domain = tsubst (TYPE_DOMAIN (t), args, complain, in_decl);
11247 if (domain == error_mark_node)
11248 return error_mark_node;
11250 /* As an optimization, we avoid regenerating the array type if
11251 it will obviously be the same as T. */
11252 if (type == TREE_TYPE (t) && domain == TYPE_DOMAIN (t))
11255 /* These checks should match the ones in grokdeclarator.
11259 The deduction may fail for any of the following reasons:
11261 -- Attempting to create an array with an element type that
11262 is void, a function type, or a reference type, or [DR337]
11263 an abstract class type. */
11264 if (TREE_CODE (type) == VOID_TYPE
11265 || TREE_CODE (type) == FUNCTION_TYPE
11266 || TREE_CODE (type) == REFERENCE_TYPE)
11268 if (complain & tf_error)
11269 error ("creating array of %qT", type);
11270 return error_mark_node;
11272 if (CLASS_TYPE_P (type) && CLASSTYPE_PURE_VIRTUALS (type))
11274 if (complain & tf_error)
11275 error ("creating array of %qT, which is an abstract class type",
11277 return error_mark_node;
11280 r = build_cplus_array_type (type, domain);
11282 if (TYPE_USER_ALIGN (t))
11284 TYPE_ALIGN (r) = TYPE_ALIGN (t);
11285 TYPE_USER_ALIGN (r) = 1;
11291 case TYPENAME_TYPE:
11293 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
11294 in_decl, /*entering_scope=*/1);
11295 tree f = tsubst_copy (TYPENAME_TYPE_FULLNAME (t), args,
11296 complain, in_decl);
11298 if (ctx == error_mark_node || f == error_mark_node)
11299 return error_mark_node;
11301 if (!MAYBE_CLASS_TYPE_P (ctx))
11303 if (complain & tf_error)
11304 error ("%qT is not a class, struct, or union type", ctx);
11305 return error_mark_node;
11307 else if (!uses_template_parms (ctx) && !TYPE_BEING_DEFINED (ctx))
11309 /* Normally, make_typename_type does not require that the CTX
11310 have complete type in order to allow things like:
11312 template <class T> struct S { typename S<T>::X Y; };
11314 But, such constructs have already been resolved by this
11315 point, so here CTX really should have complete type, unless
11316 it's a partial instantiation. */
11317 ctx = complete_type (ctx);
11318 if (!COMPLETE_TYPE_P (ctx))
11320 if (complain & tf_error)
11321 cxx_incomplete_type_error (NULL_TREE, ctx);
11322 return error_mark_node;
11326 f = make_typename_type (ctx, f, typename_type,
11327 (complain & tf_error) | tf_keep_type_decl);
11328 if (f == error_mark_node)
11330 if (TREE_CODE (f) == TYPE_DECL)
11332 complain |= tf_ignore_bad_quals;
11336 if (TREE_CODE (f) != TYPENAME_TYPE)
11338 if (TYPENAME_IS_ENUM_P (t) && TREE_CODE (f) != ENUMERAL_TYPE)
11340 if (complain & tf_error)
11341 error ("%qT resolves to %qT, which is not an enumeration type",
11344 return error_mark_node;
11346 else if (TYPENAME_IS_CLASS_P (t) && !CLASS_TYPE_P (f))
11348 if (complain & tf_error)
11349 error ("%qT resolves to %qT, which is is not a class type",
11352 return error_mark_node;
11356 return cp_build_qualified_type_real
11357 (f, cp_type_quals (f) | cp_type_quals (t), complain);
11360 case UNBOUND_CLASS_TEMPLATE:
11362 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
11363 in_decl, /*entering_scope=*/1);
11364 tree name = TYPE_IDENTIFIER (t);
11365 tree parm_list = DECL_TEMPLATE_PARMS (TYPE_NAME (t));
11367 if (ctx == error_mark_node || name == error_mark_node)
11368 return error_mark_node;
11371 parm_list = tsubst_template_parms (parm_list, args, complain);
11372 return make_unbound_class_template (ctx, name, parm_list, complain);
11379 ++cp_unevaluated_operand;
11380 ++c_inhibit_evaluation_warnings;
11382 type = tsubst_expr (TYPEOF_TYPE_EXPR (t), args,
11384 /*integral_constant_expression_p=*/false);
11386 --cp_unevaluated_operand;
11387 --c_inhibit_evaluation_warnings;
11389 type = finish_typeof (type);
11390 return cp_build_qualified_type_real (type,
11392 | cp_type_quals (type),
11396 case DECLTYPE_TYPE:
11400 ++cp_unevaluated_operand;
11401 ++c_inhibit_evaluation_warnings;
11403 type = tsubst_expr (DECLTYPE_TYPE_EXPR (t), args,
11405 /*integral_constant_expression_p=*/false);
11407 --cp_unevaluated_operand;
11408 --c_inhibit_evaluation_warnings;
11410 if (DECLTYPE_FOR_LAMBDA_CAPTURE (t))
11411 type = lambda_capture_field_type (type);
11412 else if (DECLTYPE_FOR_LAMBDA_RETURN (t))
11413 type = lambda_return_type (type);
11414 else if (DECLTYPE_FOR_LAMBDA_PROXY (t))
11415 type = lambda_proxy_type (type);
11417 type = finish_decltype_type
11418 (type, DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t), complain);
11419 return cp_build_qualified_type_real (type,
11421 | cp_type_quals (type),
11425 case UNDERLYING_TYPE:
11427 tree type = tsubst (UNDERLYING_TYPE_TYPE (t), args,
11428 complain, in_decl);
11429 return finish_underlying_type (type);
11432 case TYPE_ARGUMENT_PACK:
11433 case NONTYPE_ARGUMENT_PACK:
11435 tree r = TYPE_P (t) ? cxx_make_type (code) : make_node (code);
11437 tsubst_template_args (ARGUMENT_PACK_ARGS (t),
11441 SET_ARGUMENT_PACK_ARGS (r, packed_out);
11443 /* For template nontype argument packs, also substitute into
11445 if (code == NONTYPE_ARGUMENT_PACK)
11446 TREE_TYPE (r) = tsubst (TREE_TYPE (t), args, complain, in_decl);
11464 /* We should use one of the expression tsubsts for these codes. */
11465 gcc_unreachable ();
11468 sorry ("use of %qs in template", tree_code_name [(int) code]);
11469 return error_mark_node;
11473 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
11474 type of the expression on the left-hand side of the "." or "->"
11478 tsubst_baselink (tree baselink, tree object_type,
11479 tree args, tsubst_flags_t complain, tree in_decl)
11482 tree qualifying_scope;
11485 tree template_args = 0;
11486 bool template_id_p = false;
11488 /* A baselink indicates a function from a base class. Both the
11489 BASELINK_ACCESS_BINFO and the base class referenced may
11490 indicate bases of the template class, rather than the
11491 instantiated class. In addition, lookups that were not
11492 ambiguous before may be ambiguous now. Therefore, we perform
11493 the lookup again. */
11494 qualifying_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (baselink));
11495 qualifying_scope = tsubst (qualifying_scope, args,
11496 complain, in_decl);
11497 fns = BASELINK_FUNCTIONS (baselink);
11498 optype = tsubst (BASELINK_OPTYPE (baselink), args, complain, in_decl);
11499 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
11501 template_id_p = true;
11502 template_args = TREE_OPERAND (fns, 1);
11503 fns = TREE_OPERAND (fns, 0);
11505 template_args = tsubst_template_args (template_args, args,
11506 complain, in_decl);
11508 name = DECL_NAME (get_first_fn (fns));
11509 if (IDENTIFIER_TYPENAME_P (name))
11510 name = mangle_conv_op_name_for_type (optype);
11511 baselink = lookup_fnfields (qualifying_scope, name, /*protect=*/1);
11513 return error_mark_node;
11515 /* If lookup found a single function, mark it as used at this
11516 point. (If it lookup found multiple functions the one selected
11517 later by overload resolution will be marked as used at that
11519 if (BASELINK_P (baselink))
11520 fns = BASELINK_FUNCTIONS (baselink);
11521 if (!template_id_p && !really_overloaded_fn (fns))
11522 mark_used (OVL_CURRENT (fns));
11524 /* Add back the template arguments, if present. */
11525 if (BASELINK_P (baselink) && template_id_p)
11526 BASELINK_FUNCTIONS (baselink)
11527 = build_nt (TEMPLATE_ID_EXPR,
11528 BASELINK_FUNCTIONS (baselink),
11530 /* Update the conversion operator type. */
11531 BASELINK_OPTYPE (baselink) = optype;
11534 object_type = current_class_type;
11535 return adjust_result_of_qualified_name_lookup (baselink,
11540 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
11541 true if the qualified-id will be a postfix-expression in-and-of
11542 itself; false if more of the postfix-expression follows the
11543 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
11547 tsubst_qualified_id (tree qualified_id, tree args,
11548 tsubst_flags_t complain, tree in_decl,
11549 bool done, bool address_p)
11555 tree template_args;
11557 gcc_assert (TREE_CODE (qualified_id) == SCOPE_REF);
11559 /* Figure out what name to look up. */
11560 name = TREE_OPERAND (qualified_id, 1);
11561 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
11563 is_template = true;
11564 template_args = TREE_OPERAND (name, 1);
11566 template_args = tsubst_template_args (template_args, args,
11567 complain, in_decl);
11568 name = TREE_OPERAND (name, 0);
11572 is_template = false;
11573 template_args = NULL_TREE;
11576 /* Substitute into the qualifying scope. When there are no ARGS, we
11577 are just trying to simplify a non-dependent expression. In that
11578 case the qualifying scope may be dependent, and, in any case,
11579 substituting will not help. */
11580 scope = TREE_OPERAND (qualified_id, 0);
11583 scope = tsubst (scope, args, complain, in_decl);
11584 expr = tsubst_copy (name, args, complain, in_decl);
11589 if (dependent_scope_p (scope))
11592 expr = build_min_nt (TEMPLATE_ID_EXPR, expr, template_args);
11593 return build_qualified_name (NULL_TREE, scope, expr,
11594 QUALIFIED_NAME_IS_TEMPLATE (qualified_id));
11597 if (!BASELINK_P (name) && !DECL_P (expr))
11599 if (TREE_CODE (expr) == BIT_NOT_EXPR)
11601 /* A BIT_NOT_EXPR is used to represent a destructor. */
11602 if (!check_dtor_name (scope, TREE_OPERAND (expr, 0)))
11604 error ("qualifying type %qT does not match destructor name ~%qT",
11605 scope, TREE_OPERAND (expr, 0));
11606 expr = error_mark_node;
11609 expr = lookup_qualified_name (scope, complete_dtor_identifier,
11610 /*is_type_p=*/0, false);
11613 expr = lookup_qualified_name (scope, expr, /*is_type_p=*/0, false);
11614 if (TREE_CODE (TREE_CODE (expr) == TEMPLATE_DECL
11615 ? DECL_TEMPLATE_RESULT (expr) : expr) == TYPE_DECL)
11617 if (complain & tf_error)
11619 error ("dependent-name %qE is parsed as a non-type, but "
11620 "instantiation yields a type", qualified_id);
11621 inform (input_location, "say %<typename %E%> if a type is meant", qualified_id);
11623 return error_mark_node;
11629 check_accessibility_of_qualified_id (expr, /*object_type=*/NULL_TREE,
11631 /* Remember that there was a reference to this entity. */
11635 if (expr == error_mark_node || TREE_CODE (expr) == TREE_LIST)
11637 if (complain & tf_error)
11638 qualified_name_lookup_error (scope,
11639 TREE_OPERAND (qualified_id, 1),
11640 expr, input_location);
11641 return error_mark_node;
11645 expr = lookup_template_function (expr, template_args);
11647 if (expr == error_mark_node && complain & tf_error)
11648 qualified_name_lookup_error (scope, TREE_OPERAND (qualified_id, 1),
11649 expr, input_location);
11650 else if (TYPE_P (scope))
11652 expr = (adjust_result_of_qualified_name_lookup
11653 (expr, scope, current_class_type));
11654 expr = (finish_qualified_id_expr
11655 (scope, expr, done, address_p && PTRMEM_OK_P (qualified_id),
11656 QUALIFIED_NAME_IS_TEMPLATE (qualified_id),
11657 /*template_arg_p=*/false));
11660 /* Expressions do not generally have reference type. */
11661 if (TREE_CODE (expr) != SCOPE_REF
11662 /* However, if we're about to form a pointer-to-member, we just
11663 want the referenced member referenced. */
11664 && TREE_CODE (expr) != OFFSET_REF)
11665 expr = convert_from_reference (expr);
11670 /* Like tsubst, but deals with expressions. This function just replaces
11671 template parms; to finish processing the resultant expression, use
11675 tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl)
11677 enum tree_code code;
11680 if (t == NULL_TREE || t == error_mark_node || args == NULL_TREE)
11683 code = TREE_CODE (t);
11688 r = retrieve_local_specialization (t);
11693 /* This can happen for a parameter name used later in a function
11694 declaration (such as in a late-specified return type). Just
11695 make a dummy decl, since it's only used for its type. */
11696 gcc_assert (cp_unevaluated_operand != 0);
11697 /* We copy T because want to tsubst the PARM_DECL only,
11698 not the following PARM_DECLs that are chained to T. */
11700 r = tsubst_decl (c, args, complain);
11701 /* Give it the template pattern as its context; its true context
11702 hasn't been instantiated yet and this is good enough for
11704 DECL_CONTEXT (r) = DECL_CONTEXT (t);
11707 if (TREE_CODE (r) == ARGUMENT_PACK_SELECT)
11708 r = ARGUMENT_PACK_SELECT_ARG (r);
11717 if (DECL_TEMPLATE_PARM_P (t))
11718 return tsubst_copy (DECL_INITIAL (t), args, complain, in_decl);
11719 /* There is no need to substitute into namespace-scope
11721 if (DECL_NAMESPACE_SCOPE_P (t))
11723 /* If ARGS is NULL, then T is known to be non-dependent. */
11724 if (args == NULL_TREE)
11725 return integral_constant_value (t);
11727 /* Unfortunately, we cannot just call lookup_name here.
11730 template <int I> int f() {
11732 struct S { void g() { E e = a; } };
11735 When we instantiate f<7>::S::g(), say, lookup_name is not
11736 clever enough to find f<7>::a. */
11738 = tsubst_aggr_type (TREE_TYPE (t), args, complain, in_decl,
11739 /*entering_scope=*/0);
11741 for (v = TYPE_VALUES (enum_type);
11743 v = TREE_CHAIN (v))
11744 if (TREE_PURPOSE (v) == DECL_NAME (t))
11745 return TREE_VALUE (v);
11747 /* We didn't find the name. That should never happen; if
11748 name-lookup found it during preliminary parsing, we
11749 should find it again here during instantiation. */
11750 gcc_unreachable ();
11755 if (DECL_CONTEXT (t))
11759 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args, complain, in_decl,
11760 /*entering_scope=*/1);
11761 if (ctx != DECL_CONTEXT (t))
11763 tree r = lookup_field (ctx, DECL_NAME (t), 0, false);
11766 if (complain & tf_error)
11767 error ("using invalid field %qD", t);
11768 return error_mark_node;
11777 case FUNCTION_DECL:
11778 if ((DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t))
11779 || local_variable_p (t))
11780 t = tsubst (t, args, complain, in_decl);
11785 /* An OVERLOAD will always be a non-dependent overload set; an
11786 overload set from function scope will just be represented with an
11787 IDENTIFIER_NODE, and from class scope with a BASELINK. */
11788 gcc_assert (!uses_template_parms (t));
11792 return tsubst_baselink (t, current_class_type, args, complain, in_decl);
11794 case TEMPLATE_DECL:
11795 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
11796 return tsubst (TREE_TYPE (DECL_TEMPLATE_RESULT (t)),
11797 args, complain, in_decl);
11798 else if (DECL_FUNCTION_TEMPLATE_P (t) && DECL_MEMBER_TEMPLATE_P (t))
11799 return tsubst (t, args, complain, in_decl);
11800 else if (DECL_CLASS_SCOPE_P (t)
11801 && uses_template_parms (DECL_CONTEXT (t)))
11803 /* Template template argument like the following example need
11806 template <template <class> class TT> struct C {};
11807 template <class T> struct D {
11808 template <class U> struct E {};
11813 We are processing the template argument `E' in #1 for
11814 the template instantiation #2. Originally, `E' is a
11815 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
11816 have to substitute this with one having context `D<int>'. */
11818 tree context = tsubst (DECL_CONTEXT (t), args, complain, in_decl);
11819 return lookup_field (context, DECL_NAME(t), 0, false);
11822 /* Ordinary template template argument. */
11826 case REINTERPRET_CAST_EXPR:
11827 case CONST_CAST_EXPR:
11828 case STATIC_CAST_EXPR:
11829 case DYNAMIC_CAST_EXPR:
11832 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
11833 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
11836 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
11842 ++cp_unevaluated_operand;
11843 ++c_inhibit_evaluation_warnings;
11844 /* We only want to compute the number of arguments. */
11845 expanded = tsubst_pack_expansion (TREE_OPERAND (t, 0), args,
11846 complain, in_decl);
11847 --cp_unevaluated_operand;
11848 --c_inhibit_evaluation_warnings;
11850 if (TREE_CODE (expanded) == TREE_VEC)
11851 len = TREE_VEC_LENGTH (expanded);
11853 if (expanded == error_mark_node)
11854 return error_mark_node;
11855 else if (PACK_EXPANSION_P (expanded)
11856 || (TREE_CODE (expanded) == TREE_VEC
11858 && PACK_EXPANSION_P (TREE_VEC_ELT (expanded, len-1))))
11860 if (TREE_CODE (expanded) == TREE_VEC)
11861 expanded = TREE_VEC_ELT (expanded, len - 1);
11863 if (TYPE_P (expanded))
11864 return cxx_sizeof_or_alignof_type (expanded, SIZEOF_EXPR,
11865 complain & tf_error);
11867 return cxx_sizeof_or_alignof_expr (expanded, SIZEOF_EXPR,
11868 complain & tf_error);
11871 return build_int_cst (size_type_node, len);
11877 case TRUTH_NOT_EXPR:
11880 case UNARY_PLUS_EXPR: /* Unary + */
11882 case AT_ENCODE_EXPR:
11886 case REALPART_EXPR:
11887 case IMAGPART_EXPR:
11889 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
11890 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
11892 case COMPONENT_REF:
11897 object = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
11898 name = TREE_OPERAND (t, 1);
11899 if (TREE_CODE (name) == BIT_NOT_EXPR)
11901 name = tsubst_copy (TREE_OPERAND (name, 0), args,
11902 complain, in_decl);
11903 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
11905 else if (TREE_CODE (name) == SCOPE_REF
11906 && TREE_CODE (TREE_OPERAND (name, 1)) == BIT_NOT_EXPR)
11908 tree base = tsubst_copy (TREE_OPERAND (name, 0), args,
11909 complain, in_decl);
11910 name = TREE_OPERAND (name, 1);
11911 name = tsubst_copy (TREE_OPERAND (name, 0), args,
11912 complain, in_decl);
11913 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
11914 name = build_qualified_name (/*type=*/NULL_TREE,
11916 /*template_p=*/false);
11918 else if (TREE_CODE (name) == BASELINK)
11919 name = tsubst_baselink (name,
11920 non_reference (TREE_TYPE (object)),
11924 name = tsubst_copy (name, args, complain, in_decl);
11925 return build_nt (COMPONENT_REF, object, name, NULL_TREE);
11931 case TRUNC_DIV_EXPR:
11932 case CEIL_DIV_EXPR:
11933 case FLOOR_DIV_EXPR:
11934 case ROUND_DIV_EXPR:
11935 case EXACT_DIV_EXPR:
11939 case TRUNC_MOD_EXPR:
11940 case FLOOR_MOD_EXPR:
11941 case TRUTH_ANDIF_EXPR:
11942 case TRUTH_ORIF_EXPR:
11943 case TRUTH_AND_EXPR:
11944 case TRUTH_OR_EXPR:
11957 case COMPOUND_EXPR:
11960 case PREDECREMENT_EXPR:
11961 case PREINCREMENT_EXPR:
11962 case POSTDECREMENT_EXPR:
11963 case POSTINCREMENT_EXPR:
11965 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11966 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
11969 return build_qualified_name (/*type=*/NULL_TREE,
11970 tsubst_copy (TREE_OPERAND (t, 0),
11971 args, complain, in_decl),
11972 tsubst_copy (TREE_OPERAND (t, 1),
11973 args, complain, in_decl),
11974 QUALIFIED_NAME_IS_TEMPLATE (t));
11979 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11980 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
11981 NULL_TREE, NULL_TREE);
11985 int n = VL_EXP_OPERAND_LENGTH (t);
11986 tree result = build_vl_exp (CALL_EXPR, n);
11988 for (i = 0; i < n; i++)
11989 TREE_OPERAND (t, i) = tsubst_copy (TREE_OPERAND (t, i), args,
11990 complain, in_decl);
11996 case PSEUDO_DTOR_EXPR:
11999 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12000 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
12001 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
12002 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
12009 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12010 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
12011 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
12012 NEW_EXPR_USE_GLOBAL (r) = NEW_EXPR_USE_GLOBAL (t);
12019 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12020 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
12021 DELETE_EXPR_USE_GLOBAL (r) = DELETE_EXPR_USE_GLOBAL (t);
12022 DELETE_EXPR_USE_VEC (r) = DELETE_EXPR_USE_VEC (t);
12026 case TEMPLATE_ID_EXPR:
12028 /* Substituted template arguments */
12029 tree fn = TREE_OPERAND (t, 0);
12030 tree targs = TREE_OPERAND (t, 1);
12032 fn = tsubst_copy (fn, args, complain, in_decl);
12034 targs = tsubst_template_args (targs, args, complain, in_decl);
12036 return lookup_template_function (fn, targs);
12041 tree purpose, value, chain;
12043 if (t == void_list_node)
12046 purpose = TREE_PURPOSE (t);
12048 purpose = tsubst_copy (purpose, args, complain, in_decl);
12049 value = TREE_VALUE (t);
12051 value = tsubst_copy (value, args, complain, in_decl);
12052 chain = TREE_CHAIN (t);
12053 if (chain && chain != void_type_node)
12054 chain = tsubst_copy (chain, args, complain, in_decl);
12055 if (purpose == TREE_PURPOSE (t)
12056 && value == TREE_VALUE (t)
12057 && chain == TREE_CHAIN (t))
12059 return tree_cons (purpose, value, chain);
12064 case ENUMERAL_TYPE:
12066 case TEMPLATE_TYPE_PARM:
12067 case TEMPLATE_TEMPLATE_PARM:
12068 case BOUND_TEMPLATE_TEMPLATE_PARM:
12069 case TEMPLATE_PARM_INDEX:
12071 case REFERENCE_TYPE:
12073 case FUNCTION_TYPE:
12076 case TYPENAME_TYPE:
12077 case UNBOUND_CLASS_TEMPLATE:
12079 case DECLTYPE_TYPE:
12081 return tsubst (t, args, complain, in_decl);
12083 case IDENTIFIER_NODE:
12084 if (IDENTIFIER_TYPENAME_P (t))
12086 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12087 return mangle_conv_op_name_for_type (new_type);
12093 /* This is handled by tsubst_copy_and_build. */
12094 gcc_unreachable ();
12097 return build_x_va_arg (tsubst_copy (TREE_OPERAND (t, 0), args, complain,
12099 tsubst (TREE_TYPE (t), args, complain, in_decl));
12101 case CLEANUP_POINT_EXPR:
12102 /* We shouldn't have built any of these during initial template
12103 generation. Instead, they should be built during instantiation
12104 in response to the saved STMT_IS_FULL_EXPR_P setting. */
12105 gcc_unreachable ();
12109 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
12110 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12111 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
12112 PTRMEM_OK_P (r) = PTRMEM_OK_P (t);
12113 mark_used (TREE_OPERAND (r, 1));
12116 case EXPR_PACK_EXPANSION:
12117 error ("invalid use of pack expansion expression");
12118 return error_mark_node;
12120 case NONTYPE_ARGUMENT_PACK:
12121 error ("use %<...%> to expand argument pack");
12122 return error_mark_node;
12129 /* Instantiate any typedefs in the type. */
12130 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12131 r = fold_convert (type, t);
12132 gcc_assert (TREE_CODE (r) == code);
12137 /* These can sometimes show up in a partial instantiation, but never
12138 involve template parms. */
12139 gcc_assert (!uses_template_parms (t));
12143 /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */
12144 gcc_checking_assert (false);
12149 /* Like tsubst_copy, but specifically for OpenMP clauses. */
12152 tsubst_omp_clauses (tree clauses, tree args, tsubst_flags_t complain,
12155 tree new_clauses = NULL, nc, oc;
12157 for (oc = clauses; oc ; oc = OMP_CLAUSE_CHAIN (oc))
12159 nc = copy_node (oc);
12160 OMP_CLAUSE_CHAIN (nc) = new_clauses;
12163 switch (OMP_CLAUSE_CODE (nc))
12165 case OMP_CLAUSE_LASTPRIVATE:
12166 if (OMP_CLAUSE_LASTPRIVATE_STMT (oc))
12168 OMP_CLAUSE_LASTPRIVATE_STMT (nc) = push_stmt_list ();
12169 tsubst_expr (OMP_CLAUSE_LASTPRIVATE_STMT (oc), args, complain,
12170 in_decl, /*integral_constant_expression_p=*/false);
12171 OMP_CLAUSE_LASTPRIVATE_STMT (nc)
12172 = pop_stmt_list (OMP_CLAUSE_LASTPRIVATE_STMT (nc));
12175 case OMP_CLAUSE_PRIVATE:
12176 case OMP_CLAUSE_SHARED:
12177 case OMP_CLAUSE_FIRSTPRIVATE:
12178 case OMP_CLAUSE_REDUCTION:
12179 case OMP_CLAUSE_COPYIN:
12180 case OMP_CLAUSE_COPYPRIVATE:
12181 case OMP_CLAUSE_IF:
12182 case OMP_CLAUSE_NUM_THREADS:
12183 case OMP_CLAUSE_SCHEDULE:
12184 case OMP_CLAUSE_COLLAPSE:
12185 case OMP_CLAUSE_FINAL:
12186 OMP_CLAUSE_OPERAND (nc, 0)
12187 = tsubst_expr (OMP_CLAUSE_OPERAND (oc, 0), args, complain,
12188 in_decl, /*integral_constant_expression_p=*/false);
12190 case OMP_CLAUSE_NOWAIT:
12191 case OMP_CLAUSE_ORDERED:
12192 case OMP_CLAUSE_DEFAULT:
12193 case OMP_CLAUSE_UNTIED:
12194 case OMP_CLAUSE_MERGEABLE:
12197 gcc_unreachable ();
12201 return finish_omp_clauses (nreverse (new_clauses));
12204 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
12207 tsubst_copy_asm_operands (tree t, tree args, tsubst_flags_t complain,
12210 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
12212 tree purpose, value, chain;
12217 if (TREE_CODE (t) != TREE_LIST)
12218 return tsubst_copy_and_build (t, args, complain, in_decl,
12219 /*function_p=*/false,
12220 /*integral_constant_expression_p=*/false);
12222 if (t == void_list_node)
12225 purpose = TREE_PURPOSE (t);
12227 purpose = RECUR (purpose);
12228 value = TREE_VALUE (t);
12229 if (value && TREE_CODE (value) != LABEL_DECL)
12230 value = RECUR (value);
12231 chain = TREE_CHAIN (t);
12232 if (chain && chain != void_type_node)
12233 chain = RECUR (chain);
12234 return tree_cons (purpose, value, chain);
12238 /* Substitute one OMP_FOR iterator. */
12241 tsubst_omp_for_iterator (tree t, int i, tree declv, tree initv,
12242 tree condv, tree incrv, tree *clauses,
12243 tree args, tsubst_flags_t complain, tree in_decl,
12244 bool integral_constant_expression_p)
12246 #define RECUR(NODE) \
12247 tsubst_expr ((NODE), args, complain, in_decl, \
12248 integral_constant_expression_p)
12249 tree decl, init, cond, incr, auto_node;
12251 init = TREE_VEC_ELT (OMP_FOR_INIT (t), i);
12252 gcc_assert (TREE_CODE (init) == MODIFY_EXPR);
12253 decl = RECUR (TREE_OPERAND (init, 0));
12254 init = TREE_OPERAND (init, 1);
12255 auto_node = type_uses_auto (TREE_TYPE (decl));
12256 if (auto_node && init)
12258 tree init_expr = init;
12259 if (TREE_CODE (init_expr) == DECL_EXPR)
12260 init_expr = DECL_INITIAL (DECL_EXPR_DECL (init_expr));
12261 init_expr = RECUR (init_expr);
12263 = do_auto_deduction (TREE_TYPE (decl), init_expr, auto_node);
12265 gcc_assert (!type_dependent_expression_p (decl));
12267 if (!CLASS_TYPE_P (TREE_TYPE (decl)))
12269 cond = RECUR (TREE_VEC_ELT (OMP_FOR_COND (t), i));
12270 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
12271 if (TREE_CODE (incr) == MODIFY_EXPR)
12272 incr = build_x_modify_expr (RECUR (TREE_OPERAND (incr, 0)), NOP_EXPR,
12273 RECUR (TREE_OPERAND (incr, 1)),
12276 incr = RECUR (incr);
12277 TREE_VEC_ELT (declv, i) = decl;
12278 TREE_VEC_ELT (initv, i) = init;
12279 TREE_VEC_ELT (condv, i) = cond;
12280 TREE_VEC_ELT (incrv, i) = incr;
12284 if (init && TREE_CODE (init) != DECL_EXPR)
12287 for (c = *clauses; c ; c = OMP_CLAUSE_CHAIN (c))
12289 if ((OMP_CLAUSE_CODE (c) == OMP_CLAUSE_PRIVATE
12290 || OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LASTPRIVATE)
12291 && OMP_CLAUSE_DECL (c) == decl)
12293 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_FIRSTPRIVATE
12294 && OMP_CLAUSE_DECL (c) == decl)
12295 error ("iteration variable %qD should not be firstprivate", decl);
12296 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_REDUCTION
12297 && OMP_CLAUSE_DECL (c) == decl)
12298 error ("iteration variable %qD should not be reduction", decl);
12302 c = build_omp_clause (input_location, OMP_CLAUSE_PRIVATE);
12303 OMP_CLAUSE_DECL (c) = decl;
12304 c = finish_omp_clauses (c);
12307 OMP_CLAUSE_CHAIN (c) = *clauses;
12312 cond = TREE_VEC_ELT (OMP_FOR_COND (t), i);
12313 if (COMPARISON_CLASS_P (cond))
12314 cond = build2 (TREE_CODE (cond), boolean_type_node,
12315 RECUR (TREE_OPERAND (cond, 0)),
12316 RECUR (TREE_OPERAND (cond, 1)));
12318 cond = RECUR (cond);
12319 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
12320 switch (TREE_CODE (incr))
12322 case PREINCREMENT_EXPR:
12323 case PREDECREMENT_EXPR:
12324 case POSTINCREMENT_EXPR:
12325 case POSTDECREMENT_EXPR:
12326 incr = build2 (TREE_CODE (incr), TREE_TYPE (decl),
12327 RECUR (TREE_OPERAND (incr, 0)), NULL_TREE);
12330 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
12331 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
12333 tree rhs = TREE_OPERAND (incr, 1);
12334 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
12335 RECUR (TREE_OPERAND (incr, 0)),
12336 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
12337 RECUR (TREE_OPERAND (rhs, 0)),
12338 RECUR (TREE_OPERAND (rhs, 1))));
12341 incr = RECUR (incr);
12344 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
12345 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
12347 tree lhs = RECUR (TREE_OPERAND (incr, 0));
12348 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl), lhs,
12349 build2 (TREE_CODE (TREE_OPERAND (incr, 1)),
12350 TREE_TYPE (decl), lhs,
12351 RECUR (TREE_OPERAND (incr, 2))));
12353 else if (TREE_CODE (TREE_OPERAND (incr, 1)) == NOP_EXPR
12354 && (TREE_CODE (TREE_OPERAND (incr, 2)) == PLUS_EXPR
12355 || (TREE_CODE (TREE_OPERAND (incr, 2)) == MINUS_EXPR)))
12357 tree rhs = TREE_OPERAND (incr, 2);
12358 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
12359 RECUR (TREE_OPERAND (incr, 0)),
12360 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
12361 RECUR (TREE_OPERAND (rhs, 0)),
12362 RECUR (TREE_OPERAND (rhs, 1))));
12365 incr = RECUR (incr);
12368 incr = RECUR (incr);
12372 TREE_VEC_ELT (declv, i) = decl;
12373 TREE_VEC_ELT (initv, i) = init;
12374 TREE_VEC_ELT (condv, i) = cond;
12375 TREE_VEC_ELT (incrv, i) = incr;
12379 /* Like tsubst_copy for expressions, etc. but also does semantic
12383 tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl,
12384 bool integral_constant_expression_p)
12386 #define RECUR(NODE) \
12387 tsubst_expr ((NODE), args, complain, in_decl, \
12388 integral_constant_expression_p)
12392 if (t == NULL_TREE || t == error_mark_node)
12395 if (EXPR_HAS_LOCATION (t))
12396 input_location = EXPR_LOCATION (t);
12397 if (STATEMENT_CODE_P (TREE_CODE (t)))
12398 current_stmt_tree ()->stmts_are_full_exprs_p = STMT_IS_FULL_EXPR_P (t);
12400 switch (TREE_CODE (t))
12402 case STATEMENT_LIST:
12404 tree_stmt_iterator i;
12405 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
12406 RECUR (tsi_stmt (i));
12410 case CTOR_INITIALIZER:
12411 finish_mem_initializers (tsubst_initializer_list
12412 (TREE_OPERAND (t, 0), args));
12416 finish_return_stmt (RECUR (TREE_OPERAND (t, 0)));
12420 tmp = RECUR (EXPR_STMT_EXPR (t));
12421 if (EXPR_STMT_STMT_EXPR_RESULT (t))
12422 finish_stmt_expr_expr (tmp, cur_stmt_expr);
12424 finish_expr_stmt (tmp);
12428 do_using_directive (USING_STMT_NAMESPACE (t));
12433 tree decl, pattern_decl;
12436 pattern_decl = decl = DECL_EXPR_DECL (t);
12437 if (TREE_CODE (decl) == LABEL_DECL)
12438 finish_label_decl (DECL_NAME (decl));
12439 else if (TREE_CODE (decl) == USING_DECL)
12441 tree scope = USING_DECL_SCOPE (decl);
12442 tree name = DECL_NAME (decl);
12445 scope = tsubst (scope, args, complain, in_decl);
12446 decl = lookup_qualified_name (scope, name,
12447 /*is_type_p=*/false,
12448 /*complain=*/false);
12449 if (decl == error_mark_node || TREE_CODE (decl) == TREE_LIST)
12450 qualified_name_lookup_error (scope, name, decl, input_location);
12452 do_local_using_decl (decl, scope, name);
12456 init = DECL_INITIAL (decl);
12457 decl = tsubst (decl, args, complain, in_decl);
12458 if (decl != error_mark_node)
12460 /* By marking the declaration as instantiated, we avoid
12461 trying to instantiate it. Since instantiate_decl can't
12462 handle local variables, and since we've already done
12463 all that needs to be done, that's the right thing to
12465 if (TREE_CODE (decl) == VAR_DECL)
12466 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
12467 if (TREE_CODE (decl) == VAR_DECL
12468 && ANON_AGGR_TYPE_P (TREE_TYPE (decl)))
12469 /* Anonymous aggregates are a special case. */
12470 finish_anon_union (decl);
12473 int const_init = false;
12474 maybe_push_decl (decl);
12475 if (TREE_CODE (decl) == VAR_DECL
12476 && DECL_PRETTY_FUNCTION_P (decl))
12478 /* For __PRETTY_FUNCTION__ we have to adjust the
12480 const char *const name
12481 = cxx_printable_name (current_function_decl, 2);
12482 init = cp_fname_init (name, &TREE_TYPE (decl));
12486 tree t = RECUR (init);
12490 /* If we had an initializer but it
12491 instantiated to nothing,
12492 value-initialize the object. This will
12493 only occur when the initializer was a
12494 pack expansion where the parameter packs
12495 used in that expansion were of length
12497 init = build_value_init (TREE_TYPE (decl),
12499 if (TREE_CODE (init) == AGGR_INIT_EXPR)
12500 init = get_target_expr_sfinae (init, complain);
12506 if (TREE_CODE (decl) == VAR_DECL)
12507 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
12509 cp_finish_decl (decl, init, const_init, NULL_TREE, 0);
12514 /* A DECL_EXPR can also be used as an expression, in the condition
12515 clause of an if/for/while construct. */
12520 stmt = begin_for_stmt (NULL_TREE, NULL_TREE);
12521 RECUR (FOR_INIT_STMT (t));
12522 finish_for_init_stmt (stmt);
12523 tmp = RECUR (FOR_COND (t));
12524 finish_for_cond (tmp, stmt);
12525 tmp = RECUR (FOR_EXPR (t));
12526 finish_for_expr (tmp, stmt);
12527 RECUR (FOR_BODY (t));
12528 finish_for_stmt (stmt);
12531 case RANGE_FOR_STMT:
12534 stmt = begin_for_stmt (NULL_TREE, NULL_TREE);
12535 decl = RANGE_FOR_DECL (t);
12536 decl = tsubst (decl, args, complain, in_decl);
12537 maybe_push_decl (decl);
12538 expr = RECUR (RANGE_FOR_EXPR (t));
12539 stmt = cp_convert_range_for (stmt, decl, expr);
12540 RECUR (RANGE_FOR_BODY (t));
12541 finish_for_stmt (stmt);
12546 stmt = begin_while_stmt ();
12547 tmp = RECUR (WHILE_COND (t));
12548 finish_while_stmt_cond (tmp, stmt);
12549 RECUR (WHILE_BODY (t));
12550 finish_while_stmt (stmt);
12554 stmt = begin_do_stmt ();
12555 RECUR (DO_BODY (t));
12556 finish_do_body (stmt);
12557 tmp = RECUR (DO_COND (t));
12558 finish_do_stmt (tmp, stmt);
12562 stmt = begin_if_stmt ();
12563 tmp = RECUR (IF_COND (t));
12564 finish_if_stmt_cond (tmp, stmt);
12565 RECUR (THEN_CLAUSE (t));
12566 finish_then_clause (stmt);
12568 if (ELSE_CLAUSE (t))
12570 begin_else_clause (stmt);
12571 RECUR (ELSE_CLAUSE (t));
12572 finish_else_clause (stmt);
12575 finish_if_stmt (stmt);
12579 if (BIND_EXPR_BODY_BLOCK (t))
12580 stmt = begin_function_body ();
12582 stmt = begin_compound_stmt (BIND_EXPR_TRY_BLOCK (t)
12583 ? BCS_TRY_BLOCK : 0);
12585 RECUR (BIND_EXPR_BODY (t));
12587 if (BIND_EXPR_BODY_BLOCK (t))
12588 finish_function_body (stmt);
12590 finish_compound_stmt (stmt);
12594 finish_break_stmt ();
12597 case CONTINUE_STMT:
12598 finish_continue_stmt ();
12602 stmt = begin_switch_stmt ();
12603 tmp = RECUR (SWITCH_STMT_COND (t));
12604 finish_switch_cond (tmp, stmt);
12605 RECUR (SWITCH_STMT_BODY (t));
12606 finish_switch_stmt (stmt);
12609 case CASE_LABEL_EXPR:
12610 finish_case_label (EXPR_LOCATION (t),
12611 RECUR (CASE_LOW (t)),
12612 RECUR (CASE_HIGH (t)));
12617 tree decl = LABEL_EXPR_LABEL (t);
12620 label = finish_label_stmt (DECL_NAME (decl));
12621 if (DECL_ATTRIBUTES (decl) != NULL_TREE)
12622 cplus_decl_attributes (&label, DECL_ATTRIBUTES (decl), 0);
12627 tmp = GOTO_DESTINATION (t);
12628 if (TREE_CODE (tmp) != LABEL_DECL)
12629 /* Computed goto's must be tsubst'd into. On the other hand,
12630 non-computed gotos must not be; the identifier in question
12631 will have no binding. */
12634 tmp = DECL_NAME (tmp);
12635 finish_goto_stmt (tmp);
12639 tmp = finish_asm_stmt
12640 (ASM_VOLATILE_P (t),
12641 RECUR (ASM_STRING (t)),
12642 tsubst_copy_asm_operands (ASM_OUTPUTS (t), args, complain, in_decl),
12643 tsubst_copy_asm_operands (ASM_INPUTS (t), args, complain, in_decl),
12644 tsubst_copy_asm_operands (ASM_CLOBBERS (t), args, complain, in_decl),
12645 tsubst_copy_asm_operands (ASM_LABELS (t), args, complain, in_decl));
12647 tree asm_expr = tmp;
12648 if (TREE_CODE (asm_expr) == CLEANUP_POINT_EXPR)
12649 asm_expr = TREE_OPERAND (asm_expr, 0);
12650 ASM_INPUT_P (asm_expr) = ASM_INPUT_P (t);
12657 stmt = begin_try_block ();
12658 RECUR (TRY_STMTS (t));
12659 finish_cleanup_try_block (stmt);
12660 finish_cleanup (RECUR (TRY_HANDLERS (t)), stmt);
12664 tree compound_stmt = NULL_TREE;
12666 if (FN_TRY_BLOCK_P (t))
12667 stmt = begin_function_try_block (&compound_stmt);
12669 stmt = begin_try_block ();
12671 RECUR (TRY_STMTS (t));
12673 if (FN_TRY_BLOCK_P (t))
12674 finish_function_try_block (stmt);
12676 finish_try_block (stmt);
12678 RECUR (TRY_HANDLERS (t));
12679 if (FN_TRY_BLOCK_P (t))
12680 finish_function_handler_sequence (stmt, compound_stmt);
12682 finish_handler_sequence (stmt);
12688 tree decl = HANDLER_PARMS (t);
12692 decl = tsubst (decl, args, complain, in_decl);
12693 /* Prevent instantiate_decl from trying to instantiate
12694 this variable. We've already done all that needs to be
12696 if (decl != error_mark_node)
12697 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
12699 stmt = begin_handler ();
12700 finish_handler_parms (decl, stmt);
12701 RECUR (HANDLER_BODY (t));
12702 finish_handler (stmt);
12707 tsubst (TREE_TYPE (t), args, complain, NULL_TREE);
12710 case STATIC_ASSERT:
12713 tsubst_expr (STATIC_ASSERT_CONDITION (t),
12716 /*integral_constant_expression_p=*/true);
12717 finish_static_assert (condition,
12718 STATIC_ASSERT_MESSAGE (t),
12719 STATIC_ASSERT_SOURCE_LOCATION (t),
12720 /*member_p=*/false);
12725 tmp = tsubst_omp_clauses (OMP_PARALLEL_CLAUSES (t),
12726 args, complain, in_decl);
12727 stmt = begin_omp_parallel ();
12728 RECUR (OMP_PARALLEL_BODY (t));
12729 OMP_PARALLEL_COMBINED (finish_omp_parallel (tmp, stmt))
12730 = OMP_PARALLEL_COMBINED (t);
12734 tmp = tsubst_omp_clauses (OMP_TASK_CLAUSES (t),
12735 args, complain, in_decl);
12736 stmt = begin_omp_task ();
12737 RECUR (OMP_TASK_BODY (t));
12738 finish_omp_task (tmp, stmt);
12743 tree clauses, body, pre_body;
12744 tree declv, initv, condv, incrv;
12747 clauses = tsubst_omp_clauses (OMP_FOR_CLAUSES (t),
12748 args, complain, in_decl);
12749 declv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
12750 initv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
12751 condv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
12752 incrv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
12754 for (i = 0; i < TREE_VEC_LENGTH (OMP_FOR_INIT (t)); i++)
12755 tsubst_omp_for_iterator (t, i, declv, initv, condv, incrv,
12756 &clauses, args, complain, in_decl,
12757 integral_constant_expression_p);
12759 stmt = begin_omp_structured_block ();
12761 for (i = 0; i < TREE_VEC_LENGTH (initv); i++)
12762 if (TREE_VEC_ELT (initv, i) == NULL
12763 || TREE_CODE (TREE_VEC_ELT (initv, i)) != DECL_EXPR)
12764 TREE_VEC_ELT (initv, i) = RECUR (TREE_VEC_ELT (initv, i));
12765 else if (CLASS_TYPE_P (TREE_TYPE (TREE_VEC_ELT (initv, i))))
12767 tree init = RECUR (TREE_VEC_ELT (initv, i));
12768 gcc_assert (init == TREE_VEC_ELT (declv, i));
12769 TREE_VEC_ELT (initv, i) = NULL_TREE;
12773 tree decl_expr = TREE_VEC_ELT (initv, i);
12774 tree init = DECL_INITIAL (DECL_EXPR_DECL (decl_expr));
12775 gcc_assert (init != NULL);
12776 TREE_VEC_ELT (initv, i) = RECUR (init);
12777 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = NULL;
12779 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = init;
12782 pre_body = push_stmt_list ();
12783 RECUR (OMP_FOR_PRE_BODY (t));
12784 pre_body = pop_stmt_list (pre_body);
12786 body = push_stmt_list ();
12787 RECUR (OMP_FOR_BODY (t));
12788 body = pop_stmt_list (body);
12790 t = finish_omp_for (EXPR_LOCATION (t), declv, initv, condv, incrv,
12791 body, pre_body, clauses);
12793 add_stmt (finish_omp_structured_block (stmt));
12799 tmp = tsubst_omp_clauses (OMP_CLAUSES (t), args, complain, in_decl);
12800 stmt = push_stmt_list ();
12801 RECUR (OMP_BODY (t));
12802 stmt = pop_stmt_list (stmt);
12805 OMP_BODY (t) = stmt;
12806 OMP_CLAUSES (t) = tmp;
12814 stmt = push_stmt_list ();
12815 RECUR (OMP_BODY (t));
12816 stmt = pop_stmt_list (stmt);
12819 OMP_BODY (t) = stmt;
12824 gcc_assert (OMP_ATOMIC_DEPENDENT_P (t));
12825 if (TREE_CODE (TREE_OPERAND (t, 1)) != MODIFY_EXPR)
12827 tree op1 = TREE_OPERAND (t, 1);
12828 tree rhs1 = NULL_TREE;
12830 if (TREE_CODE (op1) == COMPOUND_EXPR)
12832 rhs1 = RECUR (TREE_OPERAND (op1, 0));
12833 op1 = TREE_OPERAND (op1, 1);
12835 lhs = RECUR (TREE_OPERAND (op1, 0));
12836 rhs = RECUR (TREE_OPERAND (op1, 1));
12837 finish_omp_atomic (OMP_ATOMIC, TREE_CODE (op1), lhs, rhs,
12838 NULL_TREE, NULL_TREE, rhs1);
12842 tree op1 = TREE_OPERAND (t, 1);
12843 tree v = NULL_TREE, lhs, rhs = NULL_TREE, lhs1 = NULL_TREE;
12844 tree rhs1 = NULL_TREE;
12845 enum tree_code code = TREE_CODE (TREE_OPERAND (op1, 1));
12846 enum tree_code opcode = NOP_EXPR;
12847 if (code == OMP_ATOMIC_READ)
12849 v = RECUR (TREE_OPERAND (op1, 0));
12850 lhs = RECUR (TREE_OPERAND (TREE_OPERAND (op1, 1), 0));
12852 else if (code == OMP_ATOMIC_CAPTURE_OLD
12853 || code == OMP_ATOMIC_CAPTURE_NEW)
12855 tree op11 = TREE_OPERAND (TREE_OPERAND (op1, 1), 1);
12856 v = RECUR (TREE_OPERAND (op1, 0));
12857 lhs1 = RECUR (TREE_OPERAND (TREE_OPERAND (op1, 1), 0));
12858 if (TREE_CODE (op11) == COMPOUND_EXPR)
12860 rhs1 = RECUR (TREE_OPERAND (op11, 0));
12861 op11 = TREE_OPERAND (op11, 1);
12863 lhs = RECUR (TREE_OPERAND (op11, 0));
12864 rhs = RECUR (TREE_OPERAND (op11, 1));
12865 opcode = TREE_CODE (op11);
12870 lhs = RECUR (TREE_OPERAND (op1, 0));
12871 rhs = RECUR (TREE_OPERAND (op1, 1));
12873 finish_omp_atomic (code, opcode, lhs, rhs, v, lhs1, rhs1);
12877 case EXPR_PACK_EXPANSION:
12878 error ("invalid use of pack expansion expression");
12879 return error_mark_node;
12881 case NONTYPE_ARGUMENT_PACK:
12882 error ("use %<...%> to expand argument pack");
12883 return error_mark_node;
12886 gcc_assert (!STATEMENT_CODE_P (TREE_CODE (t)));
12888 return tsubst_copy_and_build (t, args, complain, in_decl,
12889 /*function_p=*/false,
12890 integral_constant_expression_p);
12897 /* T is a postfix-expression that is not being used in a function
12898 call. Return the substituted version of T. */
12901 tsubst_non_call_postfix_expression (tree t, tree args,
12902 tsubst_flags_t complain,
12905 if (TREE_CODE (t) == SCOPE_REF)
12906 t = tsubst_qualified_id (t, args, complain, in_decl,
12907 /*done=*/false, /*address_p=*/false);
12909 t = tsubst_copy_and_build (t, args, complain, in_decl,
12910 /*function_p=*/false,
12911 /*integral_constant_expression_p=*/false);
12916 /* Like tsubst but deals with expressions and performs semantic
12917 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
12920 tsubst_copy_and_build (tree t,
12922 tsubst_flags_t complain,
12925 bool integral_constant_expression_p)
12927 #define RECUR(NODE) \
12928 tsubst_copy_and_build (NODE, args, complain, in_decl, \
12929 /*function_p=*/false, \
12930 integral_constant_expression_p)
12934 if (t == NULL_TREE || t == error_mark_node)
12937 switch (TREE_CODE (t))
12941 /* Fall through. */
12942 case IDENTIFIER_NODE:
12946 bool non_integral_constant_expression_p;
12947 const char *error_msg;
12949 if (IDENTIFIER_TYPENAME_P (t))
12951 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12952 t = mangle_conv_op_name_for_type (new_type);
12955 /* Look up the name. */
12956 decl = lookup_name (t);
12958 /* By convention, expressions use ERROR_MARK_NODE to indicate
12959 failure, not NULL_TREE. */
12960 if (decl == NULL_TREE)
12961 decl = error_mark_node;
12963 decl = finish_id_expression (t, decl, NULL_TREE,
12965 integral_constant_expression_p,
12966 /*allow_non_integral_constant_expression_p=*/false,
12967 &non_integral_constant_expression_p,
12968 /*template_p=*/false,
12970 /*address_p=*/false,
12971 /*template_arg_p=*/false,
12976 if (!function_p && TREE_CODE (decl) == IDENTIFIER_NODE)
12977 decl = unqualified_name_lookup_error (decl);
12981 case TEMPLATE_ID_EXPR:
12984 tree templ = RECUR (TREE_OPERAND (t, 0));
12985 tree targs = TREE_OPERAND (t, 1);
12988 targs = tsubst_template_args (targs, args, complain, in_decl);
12990 if (TREE_CODE (templ) == COMPONENT_REF)
12992 object = TREE_OPERAND (templ, 0);
12993 templ = TREE_OPERAND (templ, 1);
12996 object = NULL_TREE;
12997 templ = lookup_template_function (templ, targs);
13000 return build3 (COMPONENT_REF, TREE_TYPE (templ),
13001 object, templ, NULL_TREE);
13003 return baselink_for_fns (templ);
13008 tree r = RECUR (TREE_OPERAND (t, 0));
13010 if (REFERENCE_REF_P (t))
13012 /* A type conversion to reference type will be enclosed in
13013 such an indirect ref, but the substitution of the cast
13014 will have also added such an indirect ref. */
13015 if (TREE_CODE (TREE_TYPE (r)) == REFERENCE_TYPE)
13016 r = convert_from_reference (r);
13019 r = build_x_indirect_ref (r, RO_UNARY_STAR, complain);
13025 (tsubst (TREE_TYPE (t), args, complain, in_decl),
13026 RECUR (TREE_OPERAND (t, 0)));
13029 case REINTERPRET_CAST_EXPR:
13030 case CONST_CAST_EXPR:
13031 case DYNAMIC_CAST_EXPR:
13032 case STATIC_CAST_EXPR:
13037 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
13038 if (integral_constant_expression_p
13039 && !cast_valid_in_integral_constant_expression_p (type))
13041 if (complain & tf_error)
13042 error ("a cast to a type other than an integral or "
13043 "enumeration type cannot appear in a constant-expression");
13044 return error_mark_node;
13047 op = RECUR (TREE_OPERAND (t, 0));
13049 switch (TREE_CODE (t))
13052 return build_functional_cast (type, op, complain);
13053 case REINTERPRET_CAST_EXPR:
13054 return build_reinterpret_cast (type, op, complain);
13055 case CONST_CAST_EXPR:
13056 return build_const_cast (type, op, complain);
13057 case DYNAMIC_CAST_EXPR:
13058 return build_dynamic_cast (type, op, complain);
13059 case STATIC_CAST_EXPR:
13060 return build_static_cast (type, op, complain);
13062 gcc_unreachable ();
13066 case POSTDECREMENT_EXPR:
13067 case POSTINCREMENT_EXPR:
13068 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
13069 args, complain, in_decl);
13070 return build_x_unary_op (TREE_CODE (t), op1, complain);
13072 case PREDECREMENT_EXPR:
13073 case PREINCREMENT_EXPR:
13077 case TRUTH_NOT_EXPR:
13078 case UNARY_PLUS_EXPR: /* Unary + */
13079 case REALPART_EXPR:
13080 case IMAGPART_EXPR:
13081 return build_x_unary_op (TREE_CODE (t), RECUR (TREE_OPERAND (t, 0)),
13085 op1 = TREE_OPERAND (t, 0);
13086 if (TREE_CODE (op1) == LABEL_DECL)
13087 return finish_label_address_expr (DECL_NAME (op1),
13088 EXPR_LOCATION (op1));
13089 if (TREE_CODE (op1) == SCOPE_REF)
13090 op1 = tsubst_qualified_id (op1, args, complain, in_decl,
13091 /*done=*/true, /*address_p=*/true);
13093 op1 = tsubst_non_call_postfix_expression (op1, args, complain,
13095 return build_x_unary_op (ADDR_EXPR, op1, complain);
13100 case TRUNC_DIV_EXPR:
13101 case CEIL_DIV_EXPR:
13102 case FLOOR_DIV_EXPR:
13103 case ROUND_DIV_EXPR:
13104 case EXACT_DIV_EXPR:
13108 case TRUNC_MOD_EXPR:
13109 case FLOOR_MOD_EXPR:
13110 case TRUTH_ANDIF_EXPR:
13111 case TRUTH_ORIF_EXPR:
13112 case TRUTH_AND_EXPR:
13113 case TRUTH_OR_EXPR:
13128 return build_x_binary_op
13130 RECUR (TREE_OPERAND (t, 0)),
13131 (TREE_NO_WARNING (TREE_OPERAND (t, 0))
13133 : TREE_CODE (TREE_OPERAND (t, 0))),
13134 RECUR (TREE_OPERAND (t, 1)),
13135 (TREE_NO_WARNING (TREE_OPERAND (t, 1))
13137 : TREE_CODE (TREE_OPERAND (t, 1))),
13142 return tsubst_qualified_id (t, args, complain, in_decl, /*done=*/true,
13143 /*address_p=*/false);
13145 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
13146 args, complain, in_decl);
13147 return build_x_array_ref (op1, RECUR (TREE_OPERAND (t, 1)), complain);
13150 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
13151 return tsubst_copy (t, args, complain, in_decl);
13155 op1 = TREE_OPERAND (t, 0);
13158 /* When there are no ARGS, we are trying to evaluate a
13159 non-dependent expression from the parser. Trying to do
13160 the substitutions may not work. */
13162 op1 = TREE_TYPE (op1);
13166 ++cp_unevaluated_operand;
13167 ++c_inhibit_evaluation_warnings;
13168 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
13169 /*function_p=*/false,
13170 /*integral_constant_expression_p=*/false);
13171 --cp_unevaluated_operand;
13172 --c_inhibit_evaluation_warnings;
13175 return cxx_sizeof_or_alignof_type (op1, TREE_CODE (t),
13176 complain & tf_error);
13178 return cxx_sizeof_or_alignof_expr (op1, TREE_CODE (t),
13179 complain & tf_error);
13181 case AT_ENCODE_EXPR:
13183 op1 = TREE_OPERAND (t, 0);
13184 ++cp_unevaluated_operand;
13185 ++c_inhibit_evaluation_warnings;
13186 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
13187 /*function_p=*/false,
13188 /*integral_constant_expression_p=*/false);
13189 --cp_unevaluated_operand;
13190 --c_inhibit_evaluation_warnings;
13191 return objc_build_encode_expr (op1);
13194 case NOEXCEPT_EXPR:
13195 op1 = TREE_OPERAND (t, 0);
13196 ++cp_unevaluated_operand;
13197 ++c_inhibit_evaluation_warnings;
13198 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
13199 /*function_p=*/false,
13200 /*integral_constant_expression_p=*/false);
13201 --cp_unevaluated_operand;
13202 --c_inhibit_evaluation_warnings;
13203 return finish_noexcept_expr (op1, complain);
13207 tree r = build_x_modify_expr
13208 (RECUR (TREE_OPERAND (t, 0)),
13209 TREE_CODE (TREE_OPERAND (t, 1)),
13210 RECUR (TREE_OPERAND (t, 2)),
13212 /* TREE_NO_WARNING must be set if either the expression was
13213 parenthesized or it uses an operator such as >>= rather
13214 than plain assignment. In the former case, it was already
13215 set and must be copied. In the latter case,
13216 build_x_modify_expr sets it and it must not be reset
13218 if (TREE_NO_WARNING (t))
13219 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
13224 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
13225 args, complain, in_decl);
13226 /* Remember that there was a reference to this entity. */
13229 return build_x_arrow (op1);
13233 tree placement = RECUR (TREE_OPERAND (t, 0));
13234 tree init = RECUR (TREE_OPERAND (t, 3));
13235 VEC(tree,gc) *placement_vec;
13236 VEC(tree,gc) *init_vec;
13239 if (placement == NULL_TREE)
13240 placement_vec = NULL;
13243 placement_vec = make_tree_vector ();
13244 for (; placement != NULL_TREE; placement = TREE_CHAIN (placement))
13245 VEC_safe_push (tree, gc, placement_vec, TREE_VALUE (placement));
13248 /* If there was an initializer in the original tree, but it
13249 instantiated to an empty list, then we should pass a
13250 non-NULL empty vector to tell build_new that it was an
13251 empty initializer() rather than no initializer. This can
13252 only happen when the initializer is a pack expansion whose
13253 parameter packs are of length zero. */
13254 if (init == NULL_TREE && TREE_OPERAND (t, 3) == NULL_TREE)
13258 init_vec = make_tree_vector ();
13259 if (init == void_zero_node)
13260 gcc_assert (init_vec != NULL);
13263 for (; init != NULL_TREE; init = TREE_CHAIN (init))
13264 VEC_safe_push (tree, gc, init_vec, TREE_VALUE (init));
13268 ret = build_new (&placement_vec,
13269 tsubst (TREE_OPERAND (t, 1), args, complain, in_decl),
13270 RECUR (TREE_OPERAND (t, 2)),
13272 NEW_EXPR_USE_GLOBAL (t),
13275 if (placement_vec != NULL)
13276 release_tree_vector (placement_vec);
13277 if (init_vec != NULL)
13278 release_tree_vector (init_vec);
13284 return delete_sanity
13285 (RECUR (TREE_OPERAND (t, 0)),
13286 RECUR (TREE_OPERAND (t, 1)),
13287 DELETE_EXPR_USE_VEC (t),
13288 DELETE_EXPR_USE_GLOBAL (t),
13291 case COMPOUND_EXPR:
13292 return build_x_compound_expr (RECUR (TREE_OPERAND (t, 0)),
13293 RECUR (TREE_OPERAND (t, 1)),
13299 VEC(tree,gc) *call_args;
13300 unsigned int nargs, i;
13305 function = CALL_EXPR_FN (t);
13306 /* When we parsed the expression, we determined whether or
13307 not Koenig lookup should be performed. */
13308 koenig_p = KOENIG_LOOKUP_P (t);
13309 if (TREE_CODE (function) == SCOPE_REF)
13311 qualified_p = true;
13312 function = tsubst_qualified_id (function, args, complain, in_decl,
13314 /*address_p=*/false);
13316 else if (koenig_p && TREE_CODE (function) == IDENTIFIER_NODE)
13318 /* Do nothing; calling tsubst_copy_and_build on an identifier
13319 would incorrectly perform unqualified lookup again.
13321 Note that we can also have an IDENTIFIER_NODE if the earlier
13322 unqualified lookup found a member function; in that case
13323 koenig_p will be false and we do want to do the lookup
13324 again to find the instantiated member function.
13326 FIXME but doing that causes c++/15272, so we need to stop
13327 using IDENTIFIER_NODE in that situation. */
13328 qualified_p = false;
13332 if (TREE_CODE (function) == COMPONENT_REF)
13334 tree op = TREE_OPERAND (function, 1);
13336 qualified_p = (TREE_CODE (op) == SCOPE_REF
13337 || (BASELINK_P (op)
13338 && BASELINK_QUALIFIED_P (op)));
13341 qualified_p = false;
13343 function = tsubst_copy_and_build (function, args, complain,
13346 integral_constant_expression_p);
13348 if (BASELINK_P (function))
13349 qualified_p = true;
13352 nargs = call_expr_nargs (t);
13353 call_args = make_tree_vector ();
13354 for (i = 0; i < nargs; ++i)
13356 tree arg = CALL_EXPR_ARG (t, i);
13358 if (!PACK_EXPANSION_P (arg))
13359 VEC_safe_push (tree, gc, call_args,
13360 RECUR (CALL_EXPR_ARG (t, i)));
13363 /* Expand the pack expansion and push each entry onto
13365 arg = tsubst_pack_expansion (arg, args, complain, in_decl);
13366 if (TREE_CODE (arg) == TREE_VEC)
13368 unsigned int len, j;
13370 len = TREE_VEC_LENGTH (arg);
13371 for (j = 0; j < len; ++j)
13373 tree value = TREE_VEC_ELT (arg, j);
13374 if (value != NULL_TREE)
13375 value = convert_from_reference (value);
13376 VEC_safe_push (tree, gc, call_args, value);
13381 /* A partial substitution. Add one entry. */
13382 VEC_safe_push (tree, gc, call_args, arg);
13387 /* We do not perform argument-dependent lookup if normal
13388 lookup finds a non-function, in accordance with the
13389 expected resolution of DR 218. */
13391 && ((is_overloaded_fn (function)
13392 /* If lookup found a member function, the Koenig lookup is
13393 not appropriate, even if an unqualified-name was used
13394 to denote the function. */
13395 && !DECL_FUNCTION_MEMBER_P (get_first_fn (function)))
13396 || TREE_CODE (function) == IDENTIFIER_NODE)
13397 /* Only do this when substitution turns a dependent call
13398 into a non-dependent call. */
13399 && type_dependent_expression_p_push (t)
13400 && !any_type_dependent_arguments_p (call_args))
13401 function = perform_koenig_lookup (function, call_args, false,
13404 if (TREE_CODE (function) == IDENTIFIER_NODE
13405 && !any_type_dependent_arguments_p (call_args))
13407 if (koenig_p && (complain & tf_warning_or_error))
13409 /* For backwards compatibility and good diagnostics, try
13410 the unqualified lookup again if we aren't in SFINAE
13412 tree unq = (tsubst_copy_and_build
13413 (function, args, complain, in_decl, true,
13414 integral_constant_expression_p));
13415 if (unq != function)
13418 if (TREE_CODE (fn) == COMPONENT_REF)
13419 fn = TREE_OPERAND (fn, 1);
13420 if (is_overloaded_fn (fn))
13421 fn = get_first_fn (fn);
13422 permerror (EXPR_LOC_OR_HERE (t),
13423 "%qD was not declared in this scope, "
13424 "and no declarations were found by "
13425 "argument-dependent lookup at the point "
13426 "of instantiation", function);
13427 if (DECL_CLASS_SCOPE_P (fn))
13429 inform (EXPR_LOC_OR_HERE (t),
13430 "declarations in dependent base %qT are "
13431 "not found by unqualified lookup",
13432 DECL_CLASS_CONTEXT (fn));
13433 if (current_class_ptr)
13434 inform (EXPR_LOC_OR_HERE (t),
13435 "use %<this->%D%> instead", function);
13437 inform (EXPR_LOC_OR_HERE (t),
13438 "use %<%T::%D%> instead",
13439 current_class_name, function);
13442 inform (0, "%q+D declared here, later in the "
13443 "translation unit", fn);
13447 if (TREE_CODE (function) == IDENTIFIER_NODE)
13449 unqualified_name_lookup_error (function);
13450 release_tree_vector (call_args);
13451 return error_mark_node;
13455 /* Remember that there was a reference to this entity. */
13456 if (DECL_P (function))
13457 mark_used (function);
13459 if (TREE_CODE (function) == OFFSET_REF)
13460 ret = build_offset_ref_call_from_tree (function, &call_args);
13461 else if (TREE_CODE (function) == COMPONENT_REF)
13463 tree instance = TREE_OPERAND (function, 0);
13464 tree fn = TREE_OPERAND (function, 1);
13466 if (processing_template_decl
13467 && (type_dependent_expression_p (instance)
13468 || (!BASELINK_P (fn)
13469 && TREE_CODE (fn) != FIELD_DECL)
13470 || type_dependent_expression_p (fn)
13471 || any_type_dependent_arguments_p (call_args)))
13472 ret = build_nt_call_vec (function, call_args);
13473 else if (!BASELINK_P (fn))
13474 ret = finish_call_expr (function, &call_args,
13475 /*disallow_virtual=*/false,
13476 /*koenig_p=*/false,
13479 ret = (build_new_method_call
13481 &call_args, NULL_TREE,
13482 qualified_p ? LOOKUP_NONVIRTUAL : LOOKUP_NORMAL,
13487 ret = finish_call_expr (function, &call_args,
13488 /*disallow_virtual=*/qualified_p,
13492 release_tree_vector (call_args);
13498 return build_x_conditional_expr
13499 (RECUR (TREE_OPERAND (t, 0)),
13500 RECUR (TREE_OPERAND (t, 1)),
13501 RECUR (TREE_OPERAND (t, 2)),
13504 case PSEUDO_DTOR_EXPR:
13505 return finish_pseudo_destructor_expr
13506 (RECUR (TREE_OPERAND (t, 0)),
13507 RECUR (TREE_OPERAND (t, 1)),
13508 tsubst (TREE_OPERAND (t, 2), args, complain, in_decl));
13512 tree purpose, value, chain;
13514 if (t == void_list_node)
13517 if ((TREE_PURPOSE (t) && PACK_EXPANSION_P (TREE_PURPOSE (t)))
13518 || (TREE_VALUE (t) && PACK_EXPANSION_P (TREE_VALUE (t))))
13520 /* We have pack expansions, so expand those and
13521 create a new list out of it. */
13522 tree purposevec = NULL_TREE;
13523 tree valuevec = NULL_TREE;
13527 /* Expand the argument expressions. */
13528 if (TREE_PURPOSE (t))
13529 purposevec = tsubst_pack_expansion (TREE_PURPOSE (t), args,
13530 complain, in_decl);
13531 if (TREE_VALUE (t))
13532 valuevec = tsubst_pack_expansion (TREE_VALUE (t), args,
13533 complain, in_decl);
13535 /* Build the rest of the list. */
13536 chain = TREE_CHAIN (t);
13537 if (chain && chain != void_type_node)
13538 chain = RECUR (chain);
13540 /* Determine the number of arguments. */
13541 if (purposevec && TREE_CODE (purposevec) == TREE_VEC)
13543 len = TREE_VEC_LENGTH (purposevec);
13544 gcc_assert (!valuevec || len == TREE_VEC_LENGTH (valuevec));
13546 else if (TREE_CODE (valuevec) == TREE_VEC)
13547 len = TREE_VEC_LENGTH (valuevec);
13550 /* Since we only performed a partial substitution into
13551 the argument pack, we only return a single list
13553 if (purposevec == TREE_PURPOSE (t)
13554 && valuevec == TREE_VALUE (t)
13555 && chain == TREE_CHAIN (t))
13558 return tree_cons (purposevec, valuevec, chain);
13561 /* Convert the argument vectors into a TREE_LIST */
13565 /* Grab the Ith values. */
13567 purpose = purposevec ? TREE_VEC_ELT (purposevec, i)
13570 = valuevec ? convert_from_reference (TREE_VEC_ELT (valuevec, i))
13573 /* Build the list (backwards). */
13574 chain = tree_cons (purpose, value, chain);
13580 purpose = TREE_PURPOSE (t);
13582 purpose = RECUR (purpose);
13583 value = TREE_VALUE (t);
13585 value = RECUR (value);
13586 chain = TREE_CHAIN (t);
13587 if (chain && chain != void_type_node)
13588 chain = RECUR (chain);
13589 if (purpose == TREE_PURPOSE (t)
13590 && value == TREE_VALUE (t)
13591 && chain == TREE_CHAIN (t))
13593 return tree_cons (purpose, value, chain);
13596 case COMPONENT_REF:
13602 object = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
13603 args, complain, in_decl);
13604 /* Remember that there was a reference to this entity. */
13605 if (DECL_P (object))
13606 mark_used (object);
13607 object_type = TREE_TYPE (object);
13609 member = TREE_OPERAND (t, 1);
13610 if (BASELINK_P (member))
13611 member = tsubst_baselink (member,
13612 non_reference (TREE_TYPE (object)),
13613 args, complain, in_decl);
13615 member = tsubst_copy (member, args, complain, in_decl);
13616 if (member == error_mark_node)
13617 return error_mark_node;
13619 if (object_type && !CLASS_TYPE_P (object_type))
13621 if (SCALAR_TYPE_P (object_type))
13623 tree s = NULL_TREE;
13624 tree dtor = member;
13626 if (TREE_CODE (dtor) == SCOPE_REF)
13628 s = TREE_OPERAND (dtor, 0);
13629 dtor = TREE_OPERAND (dtor, 1);
13631 if (TREE_CODE (dtor) == BIT_NOT_EXPR)
13633 dtor = TREE_OPERAND (dtor, 0);
13635 return finish_pseudo_destructor_expr (object, s, dtor);
13639 else if (TREE_CODE (member) == SCOPE_REF
13640 && TREE_CODE (TREE_OPERAND (member, 1)) == TEMPLATE_ID_EXPR)
13645 /* Lookup the template functions now that we know what the
13647 tmpl = TREE_OPERAND (TREE_OPERAND (member, 1), 0);
13648 args = TREE_OPERAND (TREE_OPERAND (member, 1), 1);
13649 member = lookup_qualified_name (TREE_OPERAND (member, 0), tmpl,
13650 /*is_type_p=*/false,
13651 /*complain=*/false);
13652 if (BASELINK_P (member))
13654 BASELINK_FUNCTIONS (member)
13655 = build_nt (TEMPLATE_ID_EXPR, BASELINK_FUNCTIONS (member),
13657 member = (adjust_result_of_qualified_name_lookup
13658 (member, BINFO_TYPE (BASELINK_BINFO (member)),
13663 qualified_name_lookup_error (object_type, tmpl, member,
13665 return error_mark_node;
13668 else if (TREE_CODE (member) == SCOPE_REF
13669 && !CLASS_TYPE_P (TREE_OPERAND (member, 0))
13670 && TREE_CODE (TREE_OPERAND (member, 0)) != NAMESPACE_DECL)
13672 if (complain & tf_error)
13674 if (TYPE_P (TREE_OPERAND (member, 0)))
13675 error ("%qT is not a class or namespace",
13676 TREE_OPERAND (member, 0));
13678 error ("%qD is not a class or namespace",
13679 TREE_OPERAND (member, 0));
13681 return error_mark_node;
13683 else if (TREE_CODE (member) == FIELD_DECL)
13684 return finish_non_static_data_member (member, object, NULL_TREE);
13686 return finish_class_member_access_expr (object, member,
13687 /*template_p=*/false,
13693 (RECUR (TREE_OPERAND (t, 0)));
13697 VEC(constructor_elt,gc) *n;
13698 constructor_elt *ce;
13699 unsigned HOST_WIDE_INT idx;
13700 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
13701 bool process_index_p;
13703 bool need_copy_p = false;
13706 if (type == error_mark_node)
13707 return error_mark_node;
13709 /* digest_init will do the wrong thing if we let it. */
13710 if (type && TYPE_PTRMEMFUNC_P (type))
13713 /* We do not want to process the index of aggregate
13714 initializers as they are identifier nodes which will be
13715 looked up by digest_init. */
13716 process_index_p = !(type && MAYBE_CLASS_TYPE_P (type));
13718 n = VEC_copy (constructor_elt, gc, CONSTRUCTOR_ELTS (t));
13719 newlen = VEC_length (constructor_elt, n);
13720 FOR_EACH_VEC_ELT (constructor_elt, n, idx, ce)
13722 if (ce->index && process_index_p)
13723 ce->index = RECUR (ce->index);
13725 if (PACK_EXPANSION_P (ce->value))
13727 /* Substitute into the pack expansion. */
13728 ce->value = tsubst_pack_expansion (ce->value, args, complain,
13731 if (ce->value == error_mark_node
13732 || PACK_EXPANSION_P (ce->value))
13734 else if (TREE_VEC_LENGTH (ce->value) == 1)
13735 /* Just move the argument into place. */
13736 ce->value = TREE_VEC_ELT (ce->value, 0);
13739 /* Update the length of the final CONSTRUCTOR
13740 arguments vector, and note that we will need to
13742 newlen = newlen + TREE_VEC_LENGTH (ce->value) - 1;
13743 need_copy_p = true;
13747 ce->value = RECUR (ce->value);
13752 VEC(constructor_elt,gc) *old_n = n;
13754 n = VEC_alloc (constructor_elt, gc, newlen);
13755 FOR_EACH_VEC_ELT (constructor_elt, old_n, idx, ce)
13757 if (TREE_CODE (ce->value) == TREE_VEC)
13759 int i, len = TREE_VEC_LENGTH (ce->value);
13760 for (i = 0; i < len; ++i)
13761 CONSTRUCTOR_APPEND_ELT (n, 0,
13762 TREE_VEC_ELT (ce->value, i));
13765 CONSTRUCTOR_APPEND_ELT (n, 0, ce->value);
13769 r = build_constructor (init_list_type_node, n);
13770 CONSTRUCTOR_IS_DIRECT_INIT (r) = CONSTRUCTOR_IS_DIRECT_INIT (t);
13772 if (TREE_HAS_CONSTRUCTOR (t))
13773 return finish_compound_literal (type, r, complain);
13775 TREE_TYPE (r) = type;
13781 tree operand_0 = TREE_OPERAND (t, 0);
13782 if (TYPE_P (operand_0))
13784 operand_0 = tsubst (operand_0, args, complain, in_decl);
13785 return get_typeid (operand_0);
13789 operand_0 = RECUR (operand_0);
13790 return build_typeid (operand_0);
13801 tree r = tsubst_copy (t, args, complain, in_decl);
13803 if (TREE_CODE (TREE_TYPE (t)) != REFERENCE_TYPE)
13804 /* If the original type was a reference, we'll be wrapped in
13805 the appropriate INDIRECT_REF. */
13806 r = convert_from_reference (r);
13811 return build_x_va_arg (RECUR (TREE_OPERAND (t, 0)),
13812 tsubst (TREE_TYPE (t), args, complain, in_decl));
13814 case OFFSETOF_EXPR:
13815 return finish_offsetof (RECUR (TREE_OPERAND (t, 0)));
13819 tree type1 = tsubst_copy (TRAIT_EXPR_TYPE1 (t), args,
13820 complain, in_decl);
13822 tree type2 = TRAIT_EXPR_TYPE2 (t);
13824 type2 = tsubst_copy (type2, args, complain, in_decl);
13826 return finish_trait_expr (TRAIT_EXPR_KIND (t), type1, type2);
13831 tree old_stmt_expr = cur_stmt_expr;
13832 tree stmt_expr = begin_stmt_expr ();
13834 cur_stmt_expr = stmt_expr;
13835 tsubst_expr (STMT_EXPR_STMT (t), args, complain, in_decl,
13836 integral_constant_expression_p);
13837 stmt_expr = finish_stmt_expr (stmt_expr, false);
13838 cur_stmt_expr = old_stmt_expr;
13840 /* If the resulting list of expression statement is empty,
13841 fold it further into void_zero_node. */
13842 if (empty_expr_stmt_p (stmt_expr))
13843 stmt_expr = void_zero_node;
13849 t = tsubst_copy (t, args, complain, in_decl);
13850 /* As in finish_id_expression, we resolve enumeration constants
13851 to their underlying values. */
13852 if (TREE_CODE (t) == CONST_DECL)
13854 used_types_insert (TREE_TYPE (t));
13855 return DECL_INITIAL (t);
13861 tree r = build_lambda_expr ();
13863 tree type = tsubst (TREE_TYPE (t), args, complain, NULL_TREE);
13864 TREE_TYPE (r) = type;
13865 CLASSTYPE_LAMBDA_EXPR (type) = r;
13867 LAMBDA_EXPR_LOCATION (r)
13868 = LAMBDA_EXPR_LOCATION (t);
13869 LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (r)
13870 = LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (t);
13871 LAMBDA_EXPR_MUTABLE_P (r) = LAMBDA_EXPR_MUTABLE_P (t);
13872 LAMBDA_EXPR_DISCRIMINATOR (r)
13873 = (LAMBDA_EXPR_DISCRIMINATOR (t));
13874 LAMBDA_EXPR_CAPTURE_LIST (r)
13875 = RECUR (LAMBDA_EXPR_CAPTURE_LIST (t));
13876 LAMBDA_EXPR_EXTRA_SCOPE (r)
13877 = RECUR (LAMBDA_EXPR_EXTRA_SCOPE (t));
13878 gcc_assert (LAMBDA_EXPR_THIS_CAPTURE (t) == NULL_TREE
13879 && LAMBDA_EXPR_PENDING_PROXIES (t) == NULL);
13881 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
13882 determine_visibility (TYPE_NAME (type));
13883 /* Now that we know visibility, instantiate the type so we have a
13884 declaration of the op() for later calls to lambda_function. */
13885 complete_type (type);
13887 type = tsubst (LAMBDA_EXPR_RETURN_TYPE (t), args, complain, in_decl);
13889 apply_lambda_return_type (r, type);
13891 return build_lambda_object (r);
13895 /* We can get here for a constant initializer of non-dependent type.
13896 FIXME stop folding in cp_parser_initializer_clause. */
13897 gcc_assert (TREE_CONSTANT (t));
13899 tree r = get_target_expr (RECUR (TARGET_EXPR_INITIAL (t)));
13900 TREE_CONSTANT (r) = true;
13905 /* Handle Objective-C++ constructs, if appropriate. */
13908 = objcp_tsubst_copy_and_build (t, args, complain,
13909 in_decl, /*function_p=*/false);
13913 return tsubst_copy (t, args, complain, in_decl);
13919 /* Verify that the instantiated ARGS are valid. For type arguments,
13920 make sure that the type's linkage is ok. For non-type arguments,
13921 make sure they are constants if they are integral or enumerations.
13922 Emit an error under control of COMPLAIN, and return TRUE on error. */
13925 check_instantiated_arg (tree tmpl, tree t, tsubst_flags_t complain)
13927 if (ARGUMENT_PACK_P (t))
13929 tree vec = ARGUMENT_PACK_ARGS (t);
13930 int len = TREE_VEC_LENGTH (vec);
13931 bool result = false;
13934 for (i = 0; i < len; ++i)
13935 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (vec, i), complain))
13939 else if (TYPE_P (t))
13941 /* [basic.link]: A name with no linkage (notably, the name
13942 of a class or enumeration declared in a local scope)
13943 shall not be used to declare an entity with linkage.
13944 This implies that names with no linkage cannot be used as
13947 DR 757 relaxes this restriction for C++0x. */
13948 tree nt = (cxx_dialect > cxx98 ? NULL_TREE
13949 : no_linkage_check (t, /*relaxed_p=*/false));
13953 /* DR 488 makes use of a type with no linkage cause
13954 type deduction to fail. */
13955 if (complain & tf_error)
13957 if (TYPE_ANONYMOUS_P (nt))
13958 error ("%qT is/uses anonymous type", t);
13960 error ("template argument for %qD uses local type %qT",
13965 /* In order to avoid all sorts of complications, we do not
13966 allow variably-modified types as template arguments. */
13967 else if (variably_modified_type_p (t, NULL_TREE))
13969 if (complain & tf_error)
13970 error ("%qT is a variably modified type", t);
13974 /* A non-type argument of integral or enumerated type must be a
13976 else if (TREE_TYPE (t)
13977 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t))
13978 && !TREE_CONSTANT (t))
13980 if (complain & tf_error)
13981 error ("integral expression %qE is not constant", t);
13988 check_instantiated_args (tree tmpl, tree args, tsubst_flags_t complain)
13990 int ix, len = DECL_NTPARMS (tmpl);
13991 bool result = false;
13993 for (ix = 0; ix != len; ix++)
13995 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (args, ix), complain))
13998 if (result && (complain & tf_error))
13999 error (" trying to instantiate %qD", tmpl);
14003 /* In C++0x, it's possible to have a function template whose type depends
14004 on itself recursively. This is most obvious with decltype, but can also
14005 occur with enumeration scope (c++/48969). So we need to catch infinite
14006 recursion and reject the substitution at deduction time; this function
14007 will return error_mark_node for any repeated substitution.
14009 This also catches excessive recursion such as when f<N> depends on
14010 f<N-1> across all integers, and returns error_mark_node for all the
14011 substitutions back up to the initial one.
14013 This is, of course, not reentrant. */
14016 deduction_tsubst_fntype (tree fn, tree targs, tsubst_flags_t complain)
14018 static bool excessive_deduction_depth;
14019 static int deduction_depth;
14020 struct pending_template *old_last_pend = last_pending_template;
14021 struct tinst_level *old_error_tinst = last_error_tinst_level;
14023 tree fntype = TREE_TYPE (fn);
14027 if (excessive_deduction_depth)
14028 return error_mark_node;
14030 tinst = build_tree_list (fn, targs);
14031 if (!push_tinst_level (tinst))
14033 excessive_deduction_depth = true;
14035 return error_mark_node;
14038 input_location = DECL_SOURCE_LOCATION (fn);
14040 push_deduction_access_scope (fn);
14041 r = tsubst (fntype, targs, complain, NULL_TREE);
14042 pop_deduction_access_scope (fn);
14045 if (excessive_deduction_depth)
14047 r = error_mark_node;
14048 if (deduction_depth == 0)
14049 /* Reset once we're all the way out. */
14050 excessive_deduction_depth = false;
14053 pop_tinst_level ();
14054 /* We can't free this if a pending_template entry or last_error_tinst_level
14055 is pointing at it. */
14056 if (last_pending_template == old_last_pend
14057 && last_error_tinst_level == old_error_tinst)
14062 /* Instantiate the indicated variable or function template TMPL with
14063 the template arguments in TARG_PTR. */
14066 instantiate_template_1 (tree tmpl, tree orig_args, tsubst_flags_t complain)
14068 tree targ_ptr = orig_args;
14072 HOST_WIDE_INT saved_processing_template_decl;
14074 if (tmpl == error_mark_node)
14075 return error_mark_node;
14077 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
14079 /* If this function is a clone, handle it specially. */
14080 if (DECL_CLONED_FUNCTION_P (tmpl))
14085 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
14086 DECL_CLONED_FUNCTION. */
14087 spec = instantiate_template (DECL_ABSTRACT_ORIGIN (tmpl),
14088 targ_ptr, complain);
14089 if (spec == error_mark_node)
14090 return error_mark_node;
14092 /* Look for the clone. */
14093 FOR_EACH_CLONE (clone, spec)
14094 if (DECL_NAME (clone) == DECL_NAME (tmpl))
14096 /* We should always have found the clone by now. */
14097 gcc_unreachable ();
14101 /* Check to see if we already have this specialization. */
14102 gen_tmpl = most_general_template (tmpl);
14103 if (tmpl != gen_tmpl)
14104 /* The TMPL is a partial instantiation. To get a full set of
14105 arguments we must add the arguments used to perform the
14106 partial instantiation. */
14107 targ_ptr = add_outermost_template_args (DECL_TI_ARGS (tmpl),
14110 /* It would be nice to avoid hashing here and then again in tsubst_decl,
14111 but it doesn't seem to be on the hot path. */
14112 spec = retrieve_specialization (gen_tmpl, targ_ptr, 0);
14114 gcc_assert (tmpl == gen_tmpl
14115 || ((fndecl = retrieve_specialization (tmpl, orig_args, 0))
14117 || fndecl == NULL_TREE);
14119 if (spec != NULL_TREE)
14122 if (check_instantiated_args (gen_tmpl, INNERMOST_TEMPLATE_ARGS (targ_ptr),
14124 return error_mark_node;
14126 /* We are building a FUNCTION_DECL, during which the access of its
14127 parameters and return types have to be checked. However this
14128 FUNCTION_DECL which is the desired context for access checking
14129 is not built yet. We solve this chicken-and-egg problem by
14130 deferring all checks until we have the FUNCTION_DECL. */
14131 push_deferring_access_checks (dk_deferred);
14133 /* Although PROCESSING_TEMPLATE_DECL may be true at this point
14134 (because, for example, we have encountered a non-dependent
14135 function call in the body of a template function and must now
14136 determine which of several overloaded functions will be called),
14137 within the instantiation itself we are not processing a
14139 saved_processing_template_decl = processing_template_decl;
14140 processing_template_decl = 0;
14141 /* Substitute template parameters to obtain the specialization. */
14142 fndecl = tsubst (DECL_TEMPLATE_RESULT (gen_tmpl),
14143 targ_ptr, complain, gen_tmpl);
14144 processing_template_decl = saved_processing_template_decl;
14145 if (fndecl == error_mark_node)
14146 return error_mark_node;
14148 /* Now we know the specialization, compute access previously
14150 push_access_scope (fndecl);
14152 /* Some typedefs referenced from within the template code need to be access
14153 checked at template instantiation time, i.e now. These types were
14154 added to the template at parsing time. Let's get those and perfom
14155 the acces checks then. */
14156 perform_typedefs_access_check (DECL_TEMPLATE_RESULT (tmpl), targ_ptr);
14157 perform_deferred_access_checks ();
14158 pop_access_scope (fndecl);
14159 pop_deferring_access_checks ();
14161 /* The DECL_TI_TEMPLATE should always be the immediate parent
14162 template, not the most general template. */
14163 DECL_TI_TEMPLATE (fndecl) = tmpl;
14165 /* If we've just instantiated the main entry point for a function,
14166 instantiate all the alternate entry points as well. We do this
14167 by cloning the instantiation of the main entry point, not by
14168 instantiating the template clones. */
14169 if (DECL_CHAIN (gen_tmpl) && DECL_CLONED_FUNCTION_P (DECL_CHAIN (gen_tmpl)))
14170 clone_function_decl (fndecl, /*update_method_vec_p=*/0);
14175 /* Wrapper for instantiate_template_1. */
14178 instantiate_template (tree tmpl, tree orig_args, tsubst_flags_t complain)
14181 timevar_push (TV_TEMPLATE_INST);
14182 ret = instantiate_template_1 (tmpl, orig_args, complain);
14183 timevar_pop (TV_TEMPLATE_INST);
14187 /* We're going to do deduction substitution on the type of TMPL, a function
14188 template. In C++11 mode, push into that access scope. In C++03 mode,
14189 disable access checking. */
14192 push_deduction_access_scope (tree tmpl)
14194 if (cxx_dialect >= cxx0x)
14196 int ptd = processing_template_decl;
14197 push_access_scope (DECL_TEMPLATE_RESULT (tmpl));
14198 /* Preserve processing_template_decl across push_to_top_level. */
14199 if (ptd && !processing_template_decl)
14200 ++processing_template_decl;
14203 push_deferring_access_checks (dk_no_check);
14206 /* And pop back out. */
14209 pop_deduction_access_scope (tree tmpl)
14211 if (cxx_dialect >= cxx0x)
14212 pop_access_scope (DECL_TEMPLATE_RESULT (tmpl));
14214 pop_deferring_access_checks ();
14217 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
14218 NARGS elements of the arguments that are being used when calling
14219 it. TARGS is a vector into which the deduced template arguments
14222 Return zero for success, 2 for an incomplete match that doesn't resolve
14223 all the types, and 1 for complete failure. An error message will be
14224 printed only for an incomplete match.
14226 If FN is a conversion operator, or we are trying to produce a specific
14227 specialization, RETURN_TYPE is the return type desired.
14229 The EXPLICIT_TARGS are explicit template arguments provided via a
14232 The parameter STRICT is one of:
14235 We are deducing arguments for a function call, as in
14236 [temp.deduct.call].
14239 We are deducing arguments for a conversion function, as in
14240 [temp.deduct.conv].
14243 We are deducing arguments when doing an explicit instantiation
14244 as in [temp.explicit], when determining an explicit specialization
14245 as in [temp.expl.spec], or when taking the address of a function
14246 template, as in [temp.deduct.funcaddr]. */
14249 fn_type_unification (tree fn,
14250 tree explicit_targs,
14253 unsigned int nargs,
14255 unification_kind_t strict,
14262 bool incomplete_argument_packs_p = false;
14264 gcc_assert (TREE_CODE (fn) == TEMPLATE_DECL);
14266 fntype = TREE_TYPE (fn);
14267 if (explicit_targs)
14271 The specified template arguments must match the template
14272 parameters in kind (i.e., type, nontype, template), and there
14273 must not be more arguments than there are parameters;
14274 otherwise type deduction fails.
14276 Nontype arguments must match the types of the corresponding
14277 nontype template parameters, or must be convertible to the
14278 types of the corresponding nontype parameters as specified in
14279 _temp.arg.nontype_, otherwise type deduction fails.
14281 All references in the function type of the function template
14282 to the corresponding template parameters are replaced by the
14283 specified template argument values. If a substitution in a
14284 template parameter or in the function type of the function
14285 template results in an invalid type, type deduction fails. */
14286 tree tparms = DECL_INNERMOST_TEMPLATE_PARMS (fn);
14287 int i, len = TREE_VEC_LENGTH (tparms);
14288 tree converted_args;
14289 bool incomplete = false;
14291 if (explicit_targs == error_mark_node)
14292 return unify_invalid (explain_p);
14295 = (coerce_template_parms (tparms, explicit_targs, NULL_TREE,
14297 ? tf_warning_or_error
14299 /*require_all_args=*/false,
14300 /*use_default_args=*/false));
14301 if (converted_args == error_mark_node)
14304 /* Substitute the explicit args into the function type. This is
14305 necessary so that, for instance, explicitly declared function
14306 arguments can match null pointed constants. If we were given
14307 an incomplete set of explicit args, we must not do semantic
14308 processing during substitution as we could create partial
14310 for (i = 0; i < len; i++)
14312 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
14313 bool parameter_pack = false;
14315 /* Dig out the actual parm. */
14316 if (TREE_CODE (parm) == TYPE_DECL
14317 || TREE_CODE (parm) == TEMPLATE_DECL)
14319 parm = TREE_TYPE (parm);
14320 parameter_pack = TEMPLATE_TYPE_PARAMETER_PACK (parm);
14322 else if (TREE_CODE (parm) == PARM_DECL)
14324 parm = DECL_INITIAL (parm);
14325 parameter_pack = TEMPLATE_PARM_PARAMETER_PACK (parm);
14328 if (parameter_pack)
14332 template_parm_level_and_index (parm, &level, &idx);
14334 /* Mark the argument pack as "incomplete". We could
14335 still deduce more arguments during unification.
14336 We remove this mark in type_unification_real. */
14337 targ = TMPL_ARG (converted_args, level, idx);
14340 ARGUMENT_PACK_INCOMPLETE_P(targ) = 1;
14341 ARGUMENT_PACK_EXPLICIT_ARGS (targ)
14342 = ARGUMENT_PACK_ARGS (targ);
14345 /* We have some incomplete argument packs. */
14346 incomplete_argument_packs_p = true;
14350 if (incomplete_argument_packs_p)
14351 /* Any substitution is guaranteed to be incomplete if there
14352 are incomplete argument packs, because we can still deduce
14356 incomplete = NUM_TMPL_ARGS (explicit_targs) != NUM_TMPL_ARGS (targs);
14358 processing_template_decl += incomplete;
14359 fntype = deduction_tsubst_fntype (fn, converted_args,
14361 ? tf_warning_or_error
14363 processing_template_decl -= incomplete;
14365 if (fntype == error_mark_node)
14368 /* Place the explicitly specified arguments in TARGS. */
14369 for (i = NUM_TMPL_ARGS (converted_args); i--;)
14370 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (converted_args, i);
14373 /* Never do unification on the 'this' parameter. */
14374 parms = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (fntype));
14380 parms = tree_cons (NULL_TREE, TREE_TYPE (fntype), parms);
14381 new_args = XALLOCAVEC (tree, nargs + 1);
14382 new_args[0] = return_type;
14383 memcpy (new_args + 1, args, nargs * sizeof (tree));
14388 /* We allow incomplete unification without an error message here
14389 because the standard doesn't seem to explicitly prohibit it. Our
14390 callers must be ready to deal with unification failures in any
14392 result = type_unification_real (DECL_INNERMOST_TEMPLATE_PARMS (fn),
14393 targs, parms, args, nargs, /*subr=*/0,
14394 strict, flags, explain_p);
14396 /* Now that we have bindings for all of the template arguments,
14397 ensure that the arguments deduced for the template template
14398 parameters have compatible template parameter lists. We cannot
14399 check this property before we have deduced all template
14400 arguments, because the template parameter types of a template
14401 template parameter might depend on prior template parameters
14402 deduced after the template template parameter. The following
14403 ill-formed example illustrates this issue:
14405 template<typename T, template<T> class C> void f(C<5>, T);
14407 template<int N> struct X {};
14410 f(X<5>(), 5l); // error: template argument deduction fails
14413 The template parameter list of 'C' depends on the template type
14414 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
14415 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
14416 time that we deduce 'C'. */
14418 && !template_template_parm_bindings_ok_p
14419 (DECL_INNERMOST_TEMPLATE_PARMS (fn), targs))
14420 return unify_inconsistent_template_template_parameters (explain_p);
14423 /* All is well so far. Now, check:
14427 When all template arguments have been deduced, all uses of
14428 template parameters in nondeduced contexts are replaced with
14429 the corresponding deduced argument values. If the
14430 substitution results in an invalid type, as described above,
14431 type deduction fails. */
14433 tree substed = deduction_tsubst_fntype (fn, targs,
14435 ? tf_warning_or_error
14437 if (substed == error_mark_node)
14440 /* If we're looking for an exact match, check that what we got
14441 is indeed an exact match. It might not be if some template
14442 parameters are used in non-deduced contexts. */
14443 if (strict == DEDUCE_EXACT)
14448 = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (substed));
14450 sarg = tree_cons (NULL_TREE, TREE_TYPE (substed), sarg);
14451 for (i = 0; i < nargs && sarg; ++i, sarg = TREE_CHAIN (sarg))
14452 if (!same_type_p (args[i], TREE_VALUE (sarg)))
14453 return unify_type_mismatch (explain_p, args[i],
14454 TREE_VALUE (sarg));
14461 /* Adjust types before performing type deduction, as described in
14462 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
14463 sections are symmetric. PARM is the type of a function parameter
14464 or the return type of the conversion function. ARG is the type of
14465 the argument passed to the call, or the type of the value
14466 initialized with the result of the conversion function.
14467 ARG_EXPR is the original argument expression, which may be null. */
14470 maybe_adjust_types_for_deduction (unification_kind_t strict,
14484 /* Swap PARM and ARG throughout the remainder of this
14485 function; the handling is precisely symmetric since PARM
14486 will initialize ARG rather than vice versa. */
14494 /* Core issue #873: Do the DR606 thing (see below) for these cases,
14495 too, but here handle it by stripping the reference from PARM
14496 rather than by adding it to ARG. */
14497 if (TREE_CODE (*parm) == REFERENCE_TYPE
14498 && TYPE_REF_IS_RVALUE (*parm)
14499 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
14500 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
14501 && TREE_CODE (*arg) == REFERENCE_TYPE
14502 && !TYPE_REF_IS_RVALUE (*arg))
14503 *parm = TREE_TYPE (*parm);
14504 /* Nothing else to do in this case. */
14508 gcc_unreachable ();
14511 if (TREE_CODE (*parm) != REFERENCE_TYPE)
14513 /* [temp.deduct.call]
14515 If P is not a reference type:
14517 --If A is an array type, the pointer type produced by the
14518 array-to-pointer standard conversion (_conv.array_) is
14519 used in place of A for type deduction; otherwise,
14521 --If A is a function type, the pointer type produced by
14522 the function-to-pointer standard conversion
14523 (_conv.func_) is used in place of A for type deduction;
14526 --If A is a cv-qualified type, the top level
14527 cv-qualifiers of A's type are ignored for type
14529 if (TREE_CODE (*arg) == ARRAY_TYPE)
14530 *arg = build_pointer_type (TREE_TYPE (*arg));
14531 else if (TREE_CODE (*arg) == FUNCTION_TYPE)
14532 *arg = build_pointer_type (*arg);
14534 *arg = TYPE_MAIN_VARIANT (*arg);
14537 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
14538 of the form T&&, where T is a template parameter, and the argument
14539 is an lvalue, T is deduced as A& */
14540 if (TREE_CODE (*parm) == REFERENCE_TYPE
14541 && TYPE_REF_IS_RVALUE (*parm)
14542 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
14543 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
14544 && (arg_expr ? real_lvalue_p (arg_expr)
14545 /* try_one_overload doesn't provide an arg_expr, but
14546 functions are always lvalues. */
14547 : TREE_CODE (*arg) == FUNCTION_TYPE))
14548 *arg = build_reference_type (*arg);
14550 /* [temp.deduct.call]
14552 If P is a cv-qualified type, the top level cv-qualifiers
14553 of P's type are ignored for type deduction. If P is a
14554 reference type, the type referred to by P is used for
14556 *parm = TYPE_MAIN_VARIANT (*parm);
14557 if (TREE_CODE (*parm) == REFERENCE_TYPE)
14559 *parm = TREE_TYPE (*parm);
14560 result |= UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
14563 /* DR 322. For conversion deduction, remove a reference type on parm
14564 too (which has been swapped into ARG). */
14565 if (strict == DEDUCE_CONV && TREE_CODE (*arg) == REFERENCE_TYPE)
14566 *arg = TREE_TYPE (*arg);
14571 /* Most parms like fn_type_unification.
14573 If SUBR is 1, we're being called recursively (to unify the
14574 arguments of a function or method parameter of a function
14578 type_unification_real (tree tparms,
14582 unsigned int xnargs,
14584 unification_kind_t strict,
14588 tree parm, arg, arg_expr;
14590 int ntparms = TREE_VEC_LENGTH (tparms);
14592 int saw_undeduced = 0;
14595 unsigned int nargs;
14598 gcc_assert (TREE_CODE (tparms) == TREE_VEC);
14599 gcc_assert (xparms == NULL_TREE || TREE_CODE (xparms) == TREE_LIST);
14600 gcc_assert (ntparms > 0);
14602 /* Reset the number of non-defaulted template arguments contained
14604 NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs) = NULL_TREE;
14609 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL | UNIFY_ALLOW_MORE_CV_QUAL
14610 | UNIFY_ALLOW_DERIVED);
14614 sub_strict = UNIFY_ALLOW_LESS_CV_QUAL;
14618 sub_strict = UNIFY_ALLOW_NONE;
14622 gcc_unreachable ();
14631 while (parms && parms != void_list_node
14634 parm = TREE_VALUE (parms);
14636 if (TREE_CODE (parm) == TYPE_PACK_EXPANSION
14637 && (!TREE_CHAIN (parms) || TREE_CHAIN (parms) == void_list_node))
14638 /* For a function parameter pack that occurs at the end of the
14639 parameter-declaration-list, the type A of each remaining
14640 argument of the call is compared with the type P of the
14641 declarator-id of the function parameter pack. */
14644 parms = TREE_CHAIN (parms);
14646 if (TREE_CODE (parm) == TYPE_PACK_EXPANSION)
14647 /* For a function parameter pack that does not occur at the
14648 end of the parameter-declaration-list, the type of the
14649 parameter pack is a non-deduced context. */
14656 if (arg == error_mark_node)
14657 return unify_invalid (explain_p);
14658 if (arg == unknown_type_node)
14659 /* We can't deduce anything from this, but we might get all the
14660 template args from other function args. */
14663 /* Conversions will be performed on a function argument that
14664 corresponds with a function parameter that contains only
14665 non-deducible template parameters and explicitly specified
14666 template parameters. */
14667 if (!uses_template_parms (parm))
14672 type = TREE_TYPE (arg);
14676 if (same_type_p (parm, type))
14678 if (strict != DEDUCE_EXACT
14679 && can_convert_arg (parm, type, TYPE_P (arg) ? NULL_TREE : arg,
14683 if (strict == DEDUCE_EXACT)
14684 return unify_type_mismatch (explain_p, parm, arg);
14686 return unify_arg_conversion (explain_p, parm, type, arg);
14691 gcc_assert (TREE_TYPE (arg) != NULL_TREE);
14692 if (type_unknown_p (arg))
14694 /* [temp.deduct.type]
14696 A template-argument can be deduced from a pointer to
14697 function or pointer to member function argument if
14698 the set of overloaded functions does not contain
14699 function templates and at most one of a set of
14700 overloaded functions provides a unique match. */
14701 if (resolve_overloaded_unification
14702 (tparms, targs, parm, arg, strict, sub_strict, explain_p))
14705 return unify_overload_resolution_failure (explain_p, arg);
14708 arg = unlowered_expr_type (arg);
14709 if (arg == error_mark_node)
14710 return unify_invalid (explain_p);
14714 int arg_strict = sub_strict;
14717 arg_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg,
14720 if (arg == init_list_type_node && arg_expr)
14722 if (unify (tparms, targs, parm, arg, arg_strict, explain_p))
14723 /* If unification failed, the recursive call will have updated
14724 UI appropriately. */
14731 && parms != void_list_node
14732 && TREE_CODE (TREE_VALUE (parms)) == TYPE_PACK_EXPANSION)
14734 /* Unify the remaining arguments with the pack expansion type. */
14736 tree parmvec = make_tree_vec (1);
14738 /* Allocate a TREE_VEC and copy in all of the arguments */
14739 argvec = make_tree_vec (nargs - ia);
14740 for (i = 0; ia < nargs; ++ia, ++i)
14741 TREE_VEC_ELT (argvec, i) = args[ia];
14743 /* Copy the parameter into parmvec. */
14744 TREE_VEC_ELT (parmvec, 0) = TREE_VALUE (parms);
14745 if (unify_pack_expansion (tparms, targs, parmvec, argvec, strict,
14746 /*call_args_p=*/true, /*subr=*/subr, explain_p))
14749 /* Advance to the end of the list of parameters. */
14750 parms = TREE_CHAIN (parms);
14753 /* Fail if we've reached the end of the parm list, and more args
14754 are present, and the parm list isn't variadic. */
14755 if (ia < nargs && parms == void_list_node)
14756 return unify_too_many_arguments (explain_p, nargs, ia);
14757 /* Fail if parms are left and they don't have default values. */
14758 if (parms && parms != void_list_node
14759 && TREE_PURPOSE (parms) == NULL_TREE)
14761 unsigned int count = nargs;
14763 while (p && p != void_list_node)
14766 p = TREE_CHAIN (p);
14768 return unify_too_few_arguments (explain_p, ia, count);
14773 /* Check to see if we need another pass before we start clearing
14774 ARGUMENT_PACK_INCOMPLETE_P. */
14775 for (i = 0; i < ntparms; i++)
14777 tree targ = TREE_VEC_ELT (targs, i);
14778 tree tparm = TREE_VEC_ELT (tparms, i);
14780 if (targ || tparm == error_mark_node)
14782 tparm = TREE_VALUE (tparm);
14784 /* If this is an undeduced nontype parameter that depends on
14785 a type parameter, try another pass; its type may have been
14786 deduced from a later argument than the one from which
14787 this parameter can be deduced. */
14788 if (TREE_CODE (tparm) == PARM_DECL
14789 && uses_template_parms (TREE_TYPE (tparm))
14790 && !saw_undeduced++)
14794 for (i = 0; i < ntparms; i++)
14796 tree targ = TREE_VEC_ELT (targs, i);
14797 tree tparm = TREE_VEC_ELT (tparms, i);
14799 /* Clear the "incomplete" flags on all argument packs now so that
14800 substituting them into later default arguments works. */
14801 if (targ && ARGUMENT_PACK_P (targ))
14803 ARGUMENT_PACK_INCOMPLETE_P (targ) = 0;
14804 ARGUMENT_PACK_EXPLICIT_ARGS (targ) = NULL_TREE;
14807 if (targ || tparm == error_mark_node)
14809 tparm = TREE_VALUE (tparm);
14811 /* Core issue #226 (C++0x) [temp.deduct]:
14813 If a template argument has not been deduced, its
14814 default template argument, if any, is used.
14816 When we are in C++98 mode, TREE_PURPOSE will either
14817 be NULL_TREE or ERROR_MARK_NODE, so we do not need
14818 to explicitly check cxx_dialect here. */
14819 if (TREE_PURPOSE (TREE_VEC_ELT (tparms, i)))
14821 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
14822 tree arg = TREE_PURPOSE (TREE_VEC_ELT (tparms, i));
14823 arg = tsubst_template_arg (arg, targs, tf_none, NULL_TREE);
14824 arg = convert_template_argument (parm, arg, targs,
14826 ? tf_warning_or_error
14829 if (arg == error_mark_node)
14833 TREE_VEC_ELT (targs, i) = arg;
14834 /* The position of the first default template argument,
14835 is also the number of non-defaulted arguments in TARGS.
14837 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs))
14838 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, i);
14843 /* If the type parameter is a parameter pack, then it will
14844 be deduced to an empty parameter pack. */
14845 if (template_parameter_pack_p (tparm))
14849 if (TREE_CODE (tparm) == TEMPLATE_PARM_INDEX)
14851 arg = make_node (NONTYPE_ARGUMENT_PACK);
14852 TREE_TYPE (arg) = TREE_TYPE (TEMPLATE_PARM_DECL (tparm));
14853 TREE_CONSTANT (arg) = 1;
14856 arg = cxx_make_type (TYPE_ARGUMENT_PACK);
14858 SET_ARGUMENT_PACK_ARGS (arg, make_tree_vec (0));
14860 TREE_VEC_ELT (targs, i) = arg;
14864 return unify_parameter_deduction_failure (explain_p, tparm);
14867 #ifdef ENABLE_CHECKING
14868 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs))
14869 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, TREE_VEC_LENGTH (targs));
14872 return unify_success (explain_p);
14875 /* Subroutine of type_unification_real. Args are like the variables
14876 at the call site. ARG is an overloaded function (or template-id);
14877 we try deducing template args from each of the overloads, and if
14878 only one succeeds, we go with that. Modifies TARGS and returns
14879 true on success. */
14882 resolve_overloaded_unification (tree tparms,
14886 unification_kind_t strict,
14890 tree tempargs = copy_node (targs);
14892 tree goodfn = NULL_TREE;
14895 if (TREE_CODE (arg) == ADDR_EXPR)
14897 arg = TREE_OPERAND (arg, 0);
14903 if (TREE_CODE (arg) == COMPONENT_REF)
14904 /* Handle `&x' where `x' is some static or non-static member
14906 arg = TREE_OPERAND (arg, 1);
14908 if (TREE_CODE (arg) == OFFSET_REF)
14909 arg = TREE_OPERAND (arg, 1);
14911 /* Strip baselink information. */
14912 if (BASELINK_P (arg))
14913 arg = BASELINK_FUNCTIONS (arg);
14915 if (TREE_CODE (arg) == TEMPLATE_ID_EXPR)
14917 /* If we got some explicit template args, we need to plug them into
14918 the affected templates before we try to unify, in case the
14919 explicit args will completely resolve the templates in question. */
14922 tree expl_subargs = TREE_OPERAND (arg, 1);
14923 arg = TREE_OPERAND (arg, 0);
14925 for (; arg; arg = OVL_NEXT (arg))
14927 tree fn = OVL_CURRENT (arg);
14928 tree subargs, elem;
14930 if (TREE_CODE (fn) != TEMPLATE_DECL)
14933 ++processing_template_decl;
14934 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
14935 expl_subargs, /*check_ret=*/false);
14936 if (subargs && !any_dependent_template_arguments_p (subargs))
14938 elem = tsubst (TREE_TYPE (fn), subargs, tf_none, NULL_TREE);
14939 if (try_one_overload (tparms, targs, tempargs, parm,
14940 elem, strict, sub_strict, addr_p, explain_p)
14941 && (!goodfn || !decls_match (goodfn, elem)))
14949 --processing_template_decl;
14951 /* If no templates (or more than one) are fully resolved by the
14952 explicit arguments, this template-id is a non-deduced context; it
14953 could still be OK if we deduce all template arguments for the
14954 enclosing call through other arguments. */
14958 else if (TREE_CODE (arg) != OVERLOAD
14959 && TREE_CODE (arg) != FUNCTION_DECL)
14960 /* If ARG is, for example, "(0, &f)" then its type will be unknown
14961 -- but the deduction does not succeed because the expression is
14962 not just the function on its own. */
14965 for (; arg; arg = OVL_NEXT (arg))
14966 if (try_one_overload (tparms, targs, tempargs, parm,
14967 TREE_TYPE (OVL_CURRENT (arg)),
14968 strict, sub_strict, addr_p, explain_p)
14969 && (!goodfn || !decls_match (goodfn, OVL_CURRENT (arg))))
14971 goodfn = OVL_CURRENT (arg);
14975 /* [temp.deduct.type] A template-argument can be deduced from a pointer
14976 to function or pointer to member function argument if the set of
14977 overloaded functions does not contain function templates and at most
14978 one of a set of overloaded functions provides a unique match.
14980 So if we found multiple possibilities, we return success but don't
14981 deduce anything. */
14985 int i = TREE_VEC_LENGTH (targs);
14987 if (TREE_VEC_ELT (tempargs, i))
14988 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (tempargs, i);
14996 /* Core DR 115: In contexts where deduction is done and fails, or in
14997 contexts where deduction is not done, if a template argument list is
14998 specified and it, along with any default template arguments, identifies
14999 a single function template specialization, then the template-id is an
15000 lvalue for the function template specialization. */
15003 resolve_nondeduced_context (tree orig_expr)
15005 tree expr, offset, baselink;
15008 if (!type_unknown_p (orig_expr))
15013 offset = NULL_TREE;
15014 baselink = NULL_TREE;
15016 if (TREE_CODE (expr) == ADDR_EXPR)
15018 expr = TREE_OPERAND (expr, 0);
15021 if (TREE_CODE (expr) == OFFSET_REF)
15024 expr = TREE_OPERAND (expr, 1);
15026 if (TREE_CODE (expr) == BASELINK)
15029 expr = BASELINK_FUNCTIONS (expr);
15032 if (TREE_CODE (expr) == TEMPLATE_ID_EXPR)
15035 tree goodfn = NULL_TREE;
15037 /* If we got some explicit template args, we need to plug them into
15038 the affected templates before we try to unify, in case the
15039 explicit args will completely resolve the templates in question. */
15041 tree expl_subargs = TREE_OPERAND (expr, 1);
15042 tree arg = TREE_OPERAND (expr, 0);
15043 tree badfn = NULL_TREE;
15044 tree badargs = NULL_TREE;
15046 for (; arg; arg = OVL_NEXT (arg))
15048 tree fn = OVL_CURRENT (arg);
15049 tree subargs, elem;
15051 if (TREE_CODE (fn) != TEMPLATE_DECL)
15054 ++processing_template_decl;
15055 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
15056 expl_subargs, /*check_ret=*/false);
15057 if (subargs && !any_dependent_template_arguments_p (subargs))
15059 elem = instantiate_template (fn, subargs, tf_none);
15060 if (elem == error_mark_node)
15065 else if (elem && (!goodfn || !decls_match (goodfn, elem)))
15071 --processing_template_decl;
15075 mark_used (goodfn);
15078 expr = build_baselink (BASELINK_BINFO (baselink),
15079 BASELINK_ACCESS_BINFO (baselink),
15080 expr, BASELINK_OPTYPE (baselink));
15084 = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (offset, 0)));
15085 expr = build_offset_ref (base, expr, addr);
15088 expr = cp_build_addr_expr (expr, tf_warning_or_error);
15091 else if (good == 0 && badargs)
15092 /* There were no good options and at least one bad one, so let the
15093 user know what the problem is. */
15094 instantiate_template (badfn, badargs, tf_warning_or_error);
15099 /* Subroutine of resolve_overloaded_unification; does deduction for a single
15100 overload. Fills TARGS with any deduced arguments, or error_mark_node if
15101 different overloads deduce different arguments for a given parm.
15102 ADDR_P is true if the expression for which deduction is being
15103 performed was of the form "& fn" rather than simply "fn".
15105 Returns 1 on success. */
15108 try_one_overload (tree tparms,
15113 unification_kind_t strict,
15122 /* [temp.deduct.type] A template-argument can be deduced from a pointer
15123 to function or pointer to member function argument if the set of
15124 overloaded functions does not contain function templates and at most
15125 one of a set of overloaded functions provides a unique match.
15127 So if this is a template, just return success. */
15129 if (uses_template_parms (arg))
15132 if (TREE_CODE (arg) == METHOD_TYPE)
15133 arg = build_ptrmemfunc_type (build_pointer_type (arg));
15135 arg = build_pointer_type (arg);
15137 sub_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg, NULL);
15139 /* We don't copy orig_targs for this because if we have already deduced
15140 some template args from previous args, unify would complain when we
15141 try to deduce a template parameter for the same argument, even though
15142 there isn't really a conflict. */
15143 nargs = TREE_VEC_LENGTH (targs);
15144 tempargs = make_tree_vec (nargs);
15146 if (unify (tparms, tempargs, parm, arg, sub_strict, explain_p))
15149 /* First make sure we didn't deduce anything that conflicts with
15150 explicitly specified args. */
15151 for (i = nargs; i--; )
15153 tree elt = TREE_VEC_ELT (tempargs, i);
15154 tree oldelt = TREE_VEC_ELT (orig_targs, i);
15158 else if (uses_template_parms (elt))
15159 /* Since we're unifying against ourselves, we will fill in
15160 template args used in the function parm list with our own
15161 template parms. Discard them. */
15162 TREE_VEC_ELT (tempargs, i) = NULL_TREE;
15163 else if (oldelt && !template_args_equal (oldelt, elt))
15167 for (i = nargs; i--; )
15169 tree elt = TREE_VEC_ELT (tempargs, i);
15172 TREE_VEC_ELT (targs, i) = elt;
15178 /* PARM is a template class (perhaps with unbound template
15179 parameters). ARG is a fully instantiated type. If ARG can be
15180 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
15181 TARGS are as for unify. */
15184 try_class_unification (tree tparms, tree targs, tree parm, tree arg,
15187 tree copy_of_targs;
15189 if (!CLASSTYPE_TEMPLATE_INFO (arg)
15190 || (most_general_template (CLASSTYPE_TI_TEMPLATE (arg))
15191 != most_general_template (CLASSTYPE_TI_TEMPLATE (parm))))
15194 /* We need to make a new template argument vector for the call to
15195 unify. If we used TARGS, we'd clutter it up with the result of
15196 the attempted unification, even if this class didn't work out.
15197 We also don't want to commit ourselves to all the unifications
15198 we've already done, since unification is supposed to be done on
15199 an argument-by-argument basis. In other words, consider the
15200 following pathological case:
15202 template <int I, int J, int K>
15205 template <int I, int J>
15206 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
15208 template <int I, int J, int K>
15209 void f(S<I, J, K>, S<I, I, I>);
15218 Now, by the time we consider the unification involving `s2', we
15219 already know that we must have `f<0, 0, 0>'. But, even though
15220 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
15221 because there are two ways to unify base classes of S<0, 1, 2>
15222 with S<I, I, I>. If we kept the already deduced knowledge, we
15223 would reject the possibility I=1. */
15224 copy_of_targs = make_tree_vec (TREE_VEC_LENGTH (targs));
15226 /* If unification failed, we're done. */
15227 if (unify (tparms, copy_of_targs, CLASSTYPE_TI_ARGS (parm),
15228 CLASSTYPE_TI_ARGS (arg), UNIFY_ALLOW_NONE, explain_p))
15234 /* Given a template type PARM and a class type ARG, find the unique
15235 base type in ARG that is an instance of PARM. We do not examine
15236 ARG itself; only its base-classes. If there is not exactly one
15237 appropriate base class, return NULL_TREE. PARM may be the type of
15238 a partial specialization, as well as a plain template type. Used
15241 static enum template_base_result
15242 get_template_base (tree tparms, tree targs, tree parm, tree arg,
15243 bool explain_p, tree *result)
15245 tree rval = NULL_TREE;
15248 gcc_assert (RECORD_OR_UNION_CODE_P (TREE_CODE (arg)));
15250 binfo = TYPE_BINFO (complete_type (arg));
15253 /* The type could not be completed. */
15254 *result = NULL_TREE;
15255 return tbr_incomplete_type;
15258 /* Walk in inheritance graph order. The search order is not
15259 important, and this avoids multiple walks of virtual bases. */
15260 for (binfo = TREE_CHAIN (binfo); binfo; binfo = TREE_CHAIN (binfo))
15262 tree r = try_class_unification (tparms, targs, parm,
15263 BINFO_TYPE (binfo), explain_p);
15267 /* If there is more than one satisfactory baseclass, then:
15271 If they yield more than one possible deduced A, the type
15275 if (rval && !same_type_p (r, rval))
15277 *result = NULL_TREE;
15278 return tbr_ambiguous_baseclass;
15286 return tbr_success;
15289 /* Returns the level of DECL, which declares a template parameter. */
15292 template_decl_level (tree decl)
15294 switch (TREE_CODE (decl))
15297 case TEMPLATE_DECL:
15298 return TEMPLATE_TYPE_LEVEL (TREE_TYPE (decl));
15301 return TEMPLATE_PARM_LEVEL (DECL_INITIAL (decl));
15304 gcc_unreachable ();
15309 /* Decide whether ARG can be unified with PARM, considering only the
15310 cv-qualifiers of each type, given STRICT as documented for unify.
15311 Returns nonzero iff the unification is OK on that basis. */
15314 check_cv_quals_for_unify (int strict, tree arg, tree parm)
15316 int arg_quals = cp_type_quals (arg);
15317 int parm_quals = cp_type_quals (parm);
15319 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
15320 && !(strict & UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
15322 /* Although a CVR qualifier is ignored when being applied to a
15323 substituted template parameter ([8.3.2]/1 for example), that
15324 does not allow us to unify "const T" with "int&" because both
15325 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
15326 It is ok when we're allowing additional CV qualifiers
15327 at the outer level [14.8.2.1]/3,1st bullet. */
15328 if ((TREE_CODE (arg) == REFERENCE_TYPE
15329 || TREE_CODE (arg) == FUNCTION_TYPE
15330 || TREE_CODE (arg) == METHOD_TYPE)
15331 && (parm_quals & (TYPE_QUAL_CONST | TYPE_QUAL_VOLATILE)))
15334 if ((!POINTER_TYPE_P (arg) && TREE_CODE (arg) != TEMPLATE_TYPE_PARM)
15335 && (parm_quals & TYPE_QUAL_RESTRICT))
15339 if (!(strict & (UNIFY_ALLOW_MORE_CV_QUAL | UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
15340 && (arg_quals & parm_quals) != parm_quals)
15343 if (!(strict & (UNIFY_ALLOW_LESS_CV_QUAL | UNIFY_ALLOW_OUTER_LESS_CV_QUAL))
15344 && (parm_quals & arg_quals) != arg_quals)
15350 /* Determines the LEVEL and INDEX for the template parameter PARM. */
15352 template_parm_level_and_index (tree parm, int* level, int* index)
15354 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
15355 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
15356 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
15358 *index = TEMPLATE_TYPE_IDX (parm);
15359 *level = TEMPLATE_TYPE_LEVEL (parm);
15363 *index = TEMPLATE_PARM_IDX (parm);
15364 *level = TEMPLATE_PARM_LEVEL (parm);
15368 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
15370 if (unify (TP, TA, P, A, S, EP)) \
15374 /* Unifies the remaining arguments in PACKED_ARGS with the pack
15375 expansion at the end of PACKED_PARMS. Returns 0 if the type
15376 deduction succeeds, 1 otherwise. STRICT is the same as in
15377 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
15378 call argument list. We'll need to adjust the arguments to make them
15379 types. SUBR tells us if this is from a recursive call to
15380 type_unification_real. */
15382 unify_pack_expansion (tree tparms, tree targs, tree packed_parms,
15383 tree packed_args, int strict, bool call_args_p,
15384 bool subr, bool explain_p)
15387 = TREE_VEC_ELT (packed_parms, TREE_VEC_LENGTH (packed_parms) - 1);
15388 tree pattern = PACK_EXPANSION_PATTERN (parm);
15389 tree pack, packs = NULL_TREE;
15390 int i, start = TREE_VEC_LENGTH (packed_parms) - 1;
15391 int len = TREE_VEC_LENGTH (packed_args);
15393 /* Determine the parameter packs we will be deducing from the
15394 pattern, and record their current deductions. */
15395 for (pack = PACK_EXPANSION_PARAMETER_PACKS (parm);
15396 pack; pack = TREE_CHAIN (pack))
15398 tree parm_pack = TREE_VALUE (pack);
15401 /* Determine the index and level of this parameter pack. */
15402 template_parm_level_and_index (parm_pack, &level, &idx);
15404 /* Keep track of the parameter packs and their corresponding
15406 packs = tree_cons (parm_pack, TMPL_ARG (targs, level, idx), packs);
15407 TREE_TYPE (packs) = make_tree_vec (len - start);
15410 /* Loop through all of the arguments that have not yet been
15411 unified and unify each with the pattern. */
15412 for (i = start; i < len; i++)
15414 tree parm = pattern;
15416 /* For each parameter pack, clear out the deduced value so that
15417 we can deduce it again. */
15418 for (pack = packs; pack; pack = TREE_CHAIN (pack))
15421 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
15423 TMPL_ARG (targs, level, idx) = NULL_TREE;
15426 /* Unify the pattern with the current argument. */
15428 tree arg = TREE_VEC_ELT (packed_args, i);
15429 tree arg_expr = NULL_TREE;
15430 int arg_strict = strict;
15431 bool skip_arg_p = false;
15437 /* This mirrors what we do in type_unification_real. */
15441 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL
15442 | UNIFY_ALLOW_MORE_CV_QUAL
15443 | UNIFY_ALLOW_DERIVED);
15447 sub_strict = UNIFY_ALLOW_LESS_CV_QUAL;
15451 sub_strict = UNIFY_ALLOW_NONE;
15455 gcc_unreachable ();
15460 gcc_assert (TREE_TYPE (arg) != NULL_TREE);
15461 if (type_unknown_p (arg))
15463 /* [temp.deduct.type] A template-argument can be
15464 deduced from a pointer to function or pointer
15465 to member function argument if the set of
15466 overloaded functions does not contain function
15467 templates and at most one of a set of
15468 overloaded functions provides a unique
15471 if (resolve_overloaded_unification
15472 (tparms, targs, parm, arg,
15473 (unification_kind_t) strict,
15474 sub_strict, explain_p)
15483 arg = unlowered_expr_type (arg);
15484 if (arg == error_mark_node)
15489 arg_strict = sub_strict;
15493 maybe_adjust_types_for_deduction ((unification_kind_t) strict,
15494 &parm, &arg, arg_expr);
15499 /* For deduction from an init-list we need the actual list. */
15500 if (arg_expr && BRACE_ENCLOSED_INITIALIZER_P (arg_expr))
15502 RECUR_AND_CHECK_FAILURE (tparms, targs, parm, arg, arg_strict,
15507 /* For each parameter pack, collect the deduced value. */
15508 for (pack = packs; pack; pack = TREE_CHAIN (pack))
15511 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
15513 TREE_VEC_ELT (TREE_TYPE (pack), i - start) =
15514 TMPL_ARG (targs, level, idx);
15518 /* Verify that the results of unification with the parameter packs
15519 produce results consistent with what we've seen before, and make
15520 the deduced argument packs available. */
15521 for (pack = packs; pack; pack = TREE_CHAIN (pack))
15523 tree old_pack = TREE_VALUE (pack);
15524 tree new_args = TREE_TYPE (pack);
15525 int i, len = TREE_VEC_LENGTH (new_args);
15527 bool nondeduced_p = false;
15529 /* By default keep the original deduced argument pack.
15530 If necessary, more specific code is going to update the
15531 resulting deduced argument later down in this function. */
15532 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
15533 TMPL_ARG (targs, level, idx) = old_pack;
15535 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
15536 actually deduce anything. */
15537 for (i = 0; i < len && !nondeduced_p; ++i)
15538 if (TREE_VEC_ELT (new_args, i) == NULL_TREE)
15539 nondeduced_p = true;
15543 if (old_pack && ARGUMENT_PACK_INCOMPLETE_P (old_pack))
15545 /* Prepend the explicit arguments onto NEW_ARGS. */
15546 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
15547 tree old_args = new_args;
15548 int i, explicit_len = TREE_VEC_LENGTH (explicit_args);
15549 int len = explicit_len + TREE_VEC_LENGTH (old_args);
15551 /* Copy the explicit arguments. */
15552 new_args = make_tree_vec (len);
15553 for (i = 0; i < explicit_len; i++)
15554 TREE_VEC_ELT (new_args, i) = TREE_VEC_ELT (explicit_args, i);
15556 /* Copy the deduced arguments. */
15557 for (; i < len; i++)
15558 TREE_VEC_ELT (new_args, i) =
15559 TREE_VEC_ELT (old_args, i - explicit_len);
15565 /* Build the deduced *_ARGUMENT_PACK. */
15566 if (TREE_CODE (TREE_PURPOSE (pack)) == TEMPLATE_PARM_INDEX)
15568 result = make_node (NONTYPE_ARGUMENT_PACK);
15569 TREE_TYPE (result) =
15570 TREE_TYPE (TEMPLATE_PARM_DECL (TREE_PURPOSE (pack)));
15571 TREE_CONSTANT (result) = 1;
15574 result = cxx_make_type (TYPE_ARGUMENT_PACK);
15576 SET_ARGUMENT_PACK_ARGS (result, new_args);
15578 /* Note the deduced argument packs for this parameter
15580 TMPL_ARG (targs, level, idx) = result;
15582 else if (ARGUMENT_PACK_INCOMPLETE_P (old_pack)
15583 && (ARGUMENT_PACK_ARGS (old_pack)
15584 == ARGUMENT_PACK_EXPLICIT_ARGS (old_pack)))
15586 /* We only had the explicitly-provided arguments before, but
15587 now we have a complete set of arguments. */
15588 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
15590 SET_ARGUMENT_PACK_ARGS (old_pack, new_args);
15591 ARGUMENT_PACK_INCOMPLETE_P (old_pack) = 1;
15592 ARGUMENT_PACK_EXPLICIT_ARGS (old_pack) = explicit_args;
15596 tree bad_old_arg, bad_new_arg;
15597 tree old_args = ARGUMENT_PACK_ARGS (old_pack);
15599 if (!comp_template_args_with_info (old_args, new_args,
15600 &bad_old_arg, &bad_new_arg))
15601 /* Inconsistent unification of this parameter pack. */
15602 return unify_parameter_pack_inconsistent (explain_p,
15608 return unify_success (explain_p);
15611 /* Deduce the value of template parameters. TPARMS is the (innermost)
15612 set of template parameters to a template. TARGS is the bindings
15613 for those template parameters, as determined thus far; TARGS may
15614 include template arguments for outer levels of template parameters
15615 as well. PARM is a parameter to a template function, or a
15616 subcomponent of that parameter; ARG is the corresponding argument.
15617 This function attempts to match PARM with ARG in a manner
15618 consistent with the existing assignments in TARGS. If more values
15619 are deduced, then TARGS is updated.
15621 Returns 0 if the type deduction succeeds, 1 otherwise. The
15622 parameter STRICT is a bitwise or of the following flags:
15625 Require an exact match between PARM and ARG.
15626 UNIFY_ALLOW_MORE_CV_QUAL:
15627 Allow the deduced ARG to be more cv-qualified (by qualification
15628 conversion) than ARG.
15629 UNIFY_ALLOW_LESS_CV_QUAL:
15630 Allow the deduced ARG to be less cv-qualified than ARG.
15631 UNIFY_ALLOW_DERIVED:
15632 Allow the deduced ARG to be a template base class of ARG,
15633 or a pointer to a template base class of the type pointed to by
15635 UNIFY_ALLOW_INTEGER:
15636 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
15637 case for more information.
15638 UNIFY_ALLOW_OUTER_LEVEL:
15639 This is the outermost level of a deduction. Used to determine validity
15640 of qualification conversions. A valid qualification conversion must
15641 have const qualified pointers leading up to the inner type which
15642 requires additional CV quals, except at the outer level, where const
15643 is not required [conv.qual]. It would be normal to set this flag in
15644 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
15645 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
15646 This is the outermost level of a deduction, and PARM can be more CV
15647 qualified at this point.
15648 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
15649 This is the outermost level of a deduction, and PARM can be less CV
15650 qualified at this point. */
15653 unify (tree tparms, tree targs, tree parm, tree arg, int strict,
15659 int strict_in = strict;
15661 /* I don't think this will do the right thing with respect to types.
15662 But the only case I've seen it in so far has been array bounds, where
15663 signedness is the only information lost, and I think that will be
15665 while (TREE_CODE (parm) == NOP_EXPR)
15666 parm = TREE_OPERAND (parm, 0);
15668 if (arg == error_mark_node)
15669 return unify_invalid (explain_p);
15670 if (arg == unknown_type_node
15671 || arg == init_list_type_node)
15672 /* We can't deduce anything from this, but we might get all the
15673 template args from other function args. */
15674 return unify_success (explain_p);
15676 /* If PARM uses template parameters, then we can't bail out here,
15677 even if ARG == PARM, since we won't record unifications for the
15678 template parameters. We might need them if we're trying to
15679 figure out which of two things is more specialized. */
15680 if (arg == parm && !uses_template_parms (parm))
15681 return unify_success (explain_p);
15683 /* Handle init lists early, so the rest of the function can assume
15684 we're dealing with a type. */
15685 if (BRACE_ENCLOSED_INITIALIZER_P (arg))
15689 tree orig_parm = parm;
15691 /* Replace T with std::initializer_list<T> for deduction. */
15692 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
15693 && flag_deduce_init_list)
15694 parm = listify (parm);
15696 if (!is_std_init_list (parm))
15697 /* We can only deduce from an initializer list argument if the
15698 parameter is std::initializer_list; otherwise this is a
15699 non-deduced context. */
15700 return unify_success (explain_p);
15702 elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (parm), 0);
15704 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg), i, elt)
15706 int elt_strict = strict;
15708 if (elt == error_mark_node)
15709 return unify_invalid (explain_p);
15711 if (!BRACE_ENCLOSED_INITIALIZER_P (elt))
15713 tree type = TREE_TYPE (elt);
15714 /* It should only be possible to get here for a call. */
15715 gcc_assert (elt_strict & UNIFY_ALLOW_OUTER_LEVEL);
15716 elt_strict |= maybe_adjust_types_for_deduction
15717 (DEDUCE_CALL, &elttype, &type, elt);
15721 RECUR_AND_CHECK_FAILURE (tparms, targs, elttype, elt, elt_strict,
15725 /* If the std::initializer_list<T> deduction worked, replace the
15726 deduced A with std::initializer_list<A>. */
15727 if (orig_parm != parm)
15729 idx = TEMPLATE_TYPE_IDX (orig_parm);
15730 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
15731 targ = listify (targ);
15732 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = targ;
15734 return unify_success (explain_p);
15737 /* Immediately reject some pairs that won't unify because of
15738 cv-qualification mismatches. */
15739 if (TREE_CODE (arg) == TREE_CODE (parm)
15741 /* It is the elements of the array which hold the cv quals of an array
15742 type, and the elements might be template type parms. We'll check
15743 when we recurse. */
15744 && TREE_CODE (arg) != ARRAY_TYPE
15745 /* We check the cv-qualifiers when unifying with template type
15746 parameters below. We want to allow ARG `const T' to unify with
15747 PARM `T' for example, when computing which of two templates
15748 is more specialized, for example. */
15749 && TREE_CODE (arg) != TEMPLATE_TYPE_PARM
15750 && !check_cv_quals_for_unify (strict_in, arg, parm))
15751 return unify_cv_qual_mismatch (explain_p, parm, arg);
15753 if (!(strict & UNIFY_ALLOW_OUTER_LEVEL)
15754 && TYPE_P (parm) && !CP_TYPE_CONST_P (parm))
15755 strict &= ~UNIFY_ALLOW_MORE_CV_QUAL;
15756 strict &= ~UNIFY_ALLOW_OUTER_LEVEL;
15757 strict &= ~UNIFY_ALLOW_DERIVED;
15758 strict &= ~UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
15759 strict &= ~UNIFY_ALLOW_OUTER_LESS_CV_QUAL;
15761 switch (TREE_CODE (parm))
15763 case TYPENAME_TYPE:
15765 case UNBOUND_CLASS_TEMPLATE:
15766 /* In a type which contains a nested-name-specifier, template
15767 argument values cannot be deduced for template parameters used
15768 within the nested-name-specifier. */
15769 return unify_success (explain_p);
15771 case TEMPLATE_TYPE_PARM:
15772 case TEMPLATE_TEMPLATE_PARM:
15773 case BOUND_TEMPLATE_TEMPLATE_PARM:
15774 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
15775 if (tparm == error_mark_node)
15776 return unify_invalid (explain_p);
15778 if (TEMPLATE_TYPE_LEVEL (parm)
15779 != template_decl_level (tparm))
15780 /* The PARM is not one we're trying to unify. Just check
15781 to see if it matches ARG. */
15783 if (TREE_CODE (arg) == TREE_CODE (parm)
15784 && same_type_p (parm, arg))
15785 return unify_success (explain_p);
15787 return unify_type_mismatch (explain_p, parm, arg);
15789 idx = TEMPLATE_TYPE_IDX (parm);
15790 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
15791 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, idx));
15793 /* Check for mixed types and values. */
15794 if ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
15795 && TREE_CODE (tparm) != TYPE_DECL)
15796 || (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
15797 && TREE_CODE (tparm) != TEMPLATE_DECL))
15798 gcc_unreachable ();
15800 if (TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
15802 /* ARG must be constructed from a template class or a template
15803 template parameter. */
15804 if (TREE_CODE (arg) != BOUND_TEMPLATE_TEMPLATE_PARM
15805 && !CLASSTYPE_SPECIALIZATION_OF_PRIMARY_TEMPLATE_P (arg))
15806 return unify_template_deduction_failure (explain_p, parm, arg);
15809 tree parmvec = TYPE_TI_ARGS (parm);
15810 tree argvec = INNERMOST_TEMPLATE_ARGS (TYPE_TI_ARGS (arg));
15811 tree full_argvec = add_to_template_args (targs, argvec);
15813 = DECL_INNERMOST_TEMPLATE_PARMS
15814 (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (parm));
15816 int parm_variadic_p = 0;
15818 /* The resolution to DR150 makes clear that default
15819 arguments for an N-argument may not be used to bind T
15820 to a template template parameter with fewer than N
15821 parameters. It is not safe to permit the binding of
15822 default arguments as an extension, as that may change
15823 the meaning of a conforming program. Consider:
15825 struct Dense { static const unsigned int dim = 1; };
15827 template <template <typename> class View,
15829 void operator+(float, View<Block> const&);
15831 template <typename Block,
15832 unsigned int Dim = Block::dim>
15833 struct Lvalue_proxy { operator float() const; };
15837 Lvalue_proxy<Dense> p;
15842 Here, if Lvalue_proxy is permitted to bind to View, then
15843 the global operator+ will be used; if they are not, the
15844 Lvalue_proxy will be converted to float. */
15845 if (coerce_template_parms (parm_parms,
15847 TYPE_TI_TEMPLATE (parm),
15849 ? tf_warning_or_error
15851 /*require_all_args=*/true,
15852 /*use_default_args=*/false)
15853 == error_mark_node)
15856 /* Deduce arguments T, i from TT<T> or TT<i>.
15857 We check each element of PARMVEC and ARGVEC individually
15858 rather than the whole TREE_VEC since they can have
15859 different number of elements. */
15861 parmvec = expand_template_argument_pack (parmvec);
15862 argvec = expand_template_argument_pack (argvec);
15864 len = TREE_VEC_LENGTH (parmvec);
15866 /* Check if the parameters end in a pack, making them
15869 && PACK_EXPANSION_P (TREE_VEC_ELT (parmvec, len - 1)))
15870 parm_variadic_p = 1;
15872 if (TREE_VEC_LENGTH (argvec) < len - parm_variadic_p)
15873 return unify_too_few_arguments (explain_p,
15874 TREE_VEC_LENGTH (argvec), len);
15876 for (i = 0; i < len - parm_variadic_p; ++i)
15878 RECUR_AND_CHECK_FAILURE (tparms, targs,
15879 TREE_VEC_ELT (parmvec, i),
15880 TREE_VEC_ELT (argvec, i),
15881 UNIFY_ALLOW_NONE, explain_p);
15884 if (parm_variadic_p
15885 && unify_pack_expansion (tparms, targs,
15888 /*call_args_p=*/false,
15889 /*subr=*/false, explain_p))
15892 arg = TYPE_TI_TEMPLATE (arg);
15894 /* Fall through to deduce template name. */
15897 if (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
15898 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
15900 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
15902 /* Simple cases: Value already set, does match or doesn't. */
15903 if (targ != NULL_TREE && template_args_equal (targ, arg))
15904 return unify_success (explain_p);
15906 return unify_inconsistency (explain_p, parm, targ, arg);
15910 /* If PARM is `const T' and ARG is only `int', we don't have
15911 a match unless we are allowing additional qualification.
15912 If ARG is `const int' and PARM is just `T' that's OK;
15913 that binds `const int' to `T'. */
15914 if (!check_cv_quals_for_unify (strict_in | UNIFY_ALLOW_LESS_CV_QUAL,
15916 return unify_cv_qual_mismatch (explain_p, parm, arg);
15918 /* Consider the case where ARG is `const volatile int' and
15919 PARM is `const T'. Then, T should be `volatile int'. */
15920 arg = cp_build_qualified_type_real
15921 (arg, cp_type_quals (arg) & ~cp_type_quals (parm), tf_none);
15922 if (arg == error_mark_node)
15923 return unify_invalid (explain_p);
15925 /* Simple cases: Value already set, does match or doesn't. */
15926 if (targ != NULL_TREE && same_type_p (targ, arg))
15927 return unify_success (explain_p);
15929 return unify_inconsistency (explain_p, parm, targ, arg);
15931 /* Make sure that ARG is not a variable-sized array. (Note
15932 that were talking about variable-sized arrays (like
15933 `int[n]'), rather than arrays of unknown size (like
15934 `int[]').) We'll get very confused by such a type since
15935 the bound of the array is not constant, and therefore
15936 not mangleable. Besides, such types are not allowed in
15937 ISO C++, so we can do as we please here. We do allow
15938 them for 'auto' deduction, since that isn't ABI-exposed. */
15939 if (!is_auto (parm) && variably_modified_type_p (arg, NULL_TREE))
15940 return unify_vla_arg (explain_p, arg);
15942 /* Strip typedefs as in convert_template_argument. */
15943 arg = canonicalize_type_argument (arg, tf_none);
15946 /* If ARG is a parameter pack or an expansion, we cannot unify
15947 against it unless PARM is also a parameter pack. */
15948 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
15949 && !template_parameter_pack_p (parm))
15950 return unify_parameter_pack_mismatch (explain_p, parm, arg);
15952 /* If the argument deduction results is a METHOD_TYPE,
15953 then there is a problem.
15954 METHOD_TYPE doesn't map to any real C++ type the result of
15955 the deduction can not be of that type. */
15956 if (TREE_CODE (arg) == METHOD_TYPE)
15957 return unify_method_type_error (explain_p, arg);
15959 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
15960 return unify_success (explain_p);
15962 case TEMPLATE_PARM_INDEX:
15963 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
15964 if (tparm == error_mark_node)
15965 return unify_invalid (explain_p);
15967 if (TEMPLATE_PARM_LEVEL (parm)
15968 != template_decl_level (tparm))
15970 /* The PARM is not one we're trying to unify. Just check
15971 to see if it matches ARG. */
15972 int result = !(TREE_CODE (arg) == TREE_CODE (parm)
15973 && cp_tree_equal (parm, arg));
15975 unify_expression_unequal (explain_p, parm, arg);
15979 idx = TEMPLATE_PARM_IDX (parm);
15980 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
15984 int x = !cp_tree_equal (targ, arg);
15986 unify_inconsistency (explain_p, parm, targ, arg);
15990 /* [temp.deduct.type] If, in the declaration of a function template
15991 with a non-type template-parameter, the non-type
15992 template-parameter is used in an expression in the function
15993 parameter-list and, if the corresponding template-argument is
15994 deduced, the template-argument type shall match the type of the
15995 template-parameter exactly, except that a template-argument
15996 deduced from an array bound may be of any integral type.
15997 The non-type parameter might use already deduced type parameters. */
15998 tparm = tsubst (TREE_TYPE (parm), targs, 0, NULL_TREE);
15999 if (!TREE_TYPE (arg))
16000 /* Template-parameter dependent expression. Just accept it for now.
16001 It will later be processed in convert_template_argument. */
16003 else if (same_type_p (TREE_TYPE (arg), tparm))
16005 else if ((strict & UNIFY_ALLOW_INTEGER)
16006 && (TREE_CODE (tparm) == INTEGER_TYPE
16007 || TREE_CODE (tparm) == BOOLEAN_TYPE))
16008 /* Convert the ARG to the type of PARM; the deduced non-type
16009 template argument must exactly match the types of the
16010 corresponding parameter. */
16011 arg = fold (build_nop (tparm, arg));
16012 else if (uses_template_parms (tparm))
16013 /* We haven't deduced the type of this parameter yet. Try again
16015 return unify_success (explain_p);
16017 return unify_type_mismatch (explain_p, tparm, arg);
16019 /* If ARG is a parameter pack or an expansion, we cannot unify
16020 against it unless PARM is also a parameter pack. */
16021 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
16022 && !TEMPLATE_PARM_PARAMETER_PACK (parm))
16023 return unify_parameter_pack_mismatch (explain_p, parm, arg);
16025 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
16026 return unify_success (explain_p);
16030 /* A pointer-to-member constant can be unified only with
16031 another constant. */
16032 if (TREE_CODE (arg) != PTRMEM_CST)
16033 return unify_ptrmem_cst_mismatch (explain_p, parm, arg);
16035 /* Just unify the class member. It would be useless (and possibly
16036 wrong, depending on the strict flags) to unify also
16037 PTRMEM_CST_CLASS, because we want to be sure that both parm and
16038 arg refer to the same variable, even if through different
16039 classes. For instance:
16041 struct A { int x; };
16044 Unification of &A::x and &B::x must succeed. */
16045 return unify (tparms, targs, PTRMEM_CST_MEMBER (parm),
16046 PTRMEM_CST_MEMBER (arg), strict, explain_p);
16051 if (TREE_CODE (arg) != POINTER_TYPE)
16052 return unify_type_mismatch (explain_p, parm, arg);
16054 /* [temp.deduct.call]
16056 A can be another pointer or pointer to member type that can
16057 be converted to the deduced A via a qualification
16058 conversion (_conv.qual_).
16060 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
16061 This will allow for additional cv-qualification of the
16062 pointed-to types if appropriate. */
16064 if (TREE_CODE (TREE_TYPE (arg)) == RECORD_TYPE)
16065 /* The derived-to-base conversion only persists through one
16066 level of pointers. */
16067 strict |= (strict_in & UNIFY_ALLOW_DERIVED);
16069 return unify (tparms, targs, TREE_TYPE (parm),
16070 TREE_TYPE (arg), strict, explain_p);
16073 case REFERENCE_TYPE:
16074 if (TREE_CODE (arg) != REFERENCE_TYPE)
16075 return unify_type_mismatch (explain_p, parm, arg);
16076 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
16077 strict & UNIFY_ALLOW_MORE_CV_QUAL, explain_p);
16080 if (TREE_CODE (arg) != ARRAY_TYPE)
16081 return unify_type_mismatch (explain_p, parm, arg);
16082 if ((TYPE_DOMAIN (parm) == NULL_TREE)
16083 != (TYPE_DOMAIN (arg) == NULL_TREE))
16084 return unify_type_mismatch (explain_p, parm, arg);
16085 if (TYPE_DOMAIN (parm) != NULL_TREE)
16092 /* Our representation of array types uses "N - 1" as the
16093 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
16094 not an integer constant. We cannot unify arbitrarily
16095 complex expressions, so we eliminate the MINUS_EXPRs
16097 parm_max = TYPE_MAX_VALUE (TYPE_DOMAIN (parm));
16098 parm_cst = TREE_CODE (parm_max) == INTEGER_CST;
16101 gcc_assert (TREE_CODE (parm_max) == MINUS_EXPR);
16102 parm_max = TREE_OPERAND (parm_max, 0);
16104 arg_max = TYPE_MAX_VALUE (TYPE_DOMAIN (arg));
16105 arg_cst = TREE_CODE (arg_max) == INTEGER_CST;
16108 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
16109 trying to unify the type of a variable with the type
16110 of a template parameter. For example:
16112 template <unsigned int N>
16113 void f (char (&) [N]);
16120 Here, the type of the ARG will be "int [g(i)]", and
16121 may be a SAVE_EXPR, etc. */
16122 if (TREE_CODE (arg_max) != MINUS_EXPR)
16123 return unify_vla_arg (explain_p, arg);
16124 arg_max = TREE_OPERAND (arg_max, 0);
16127 /* If only one of the bounds used a MINUS_EXPR, compensate
16128 by adding one to the other bound. */
16129 if (parm_cst && !arg_cst)
16130 parm_max = fold_build2_loc (input_location, PLUS_EXPR,
16134 else if (arg_cst && !parm_cst)
16135 arg_max = fold_build2_loc (input_location, PLUS_EXPR,
16140 RECUR_AND_CHECK_FAILURE (tparms, targs, parm_max, arg_max,
16141 UNIFY_ALLOW_INTEGER, explain_p);
16143 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
16144 strict & UNIFY_ALLOW_MORE_CV_QUAL, explain_p);
16151 case ENUMERAL_TYPE:
16153 if (TREE_CODE (arg) != TREE_CODE (parm))
16154 return unify_type_mismatch (explain_p, parm, arg);
16156 /* We have already checked cv-qualification at the top of the
16158 if (!same_type_ignoring_top_level_qualifiers_p (arg, parm))
16159 return unify_type_mismatch (explain_p, parm, arg);
16161 /* As far as unification is concerned, this wins. Later checks
16162 will invalidate it if necessary. */
16163 return unify_success (explain_p);
16165 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
16166 /* Type INTEGER_CST can come from ordinary constant template args. */
16168 while (TREE_CODE (arg) == NOP_EXPR)
16169 arg = TREE_OPERAND (arg, 0);
16171 if (TREE_CODE (arg) != INTEGER_CST)
16172 return unify_template_argument_mismatch (explain_p, parm, arg);
16173 return (tree_int_cst_equal (parm, arg)
16174 ? unify_success (explain_p)
16175 : unify_template_argument_mismatch (explain_p, parm, arg));
16180 if (TREE_CODE (arg) != TREE_VEC)
16181 return unify_template_argument_mismatch (explain_p, parm, arg);
16182 if (TREE_VEC_LENGTH (parm) != TREE_VEC_LENGTH (arg))
16183 return unify_arity (explain_p, TREE_VEC_LENGTH (arg),
16184 TREE_VEC_LENGTH (parm));
16185 for (i = 0; i < TREE_VEC_LENGTH (parm); ++i)
16186 RECUR_AND_CHECK_FAILURE (tparms, targs,
16187 TREE_VEC_ELT (parm, i),
16188 TREE_VEC_ELT (arg, i),
16189 UNIFY_ALLOW_NONE, explain_p);
16190 return unify_success (explain_p);
16195 if (TREE_CODE (arg) != TREE_CODE (parm))
16196 return unify_type_mismatch (explain_p, parm, arg);
16198 if (TYPE_PTRMEMFUNC_P (parm))
16200 if (!TYPE_PTRMEMFUNC_P (arg))
16201 return unify_type_mismatch (explain_p, parm, arg);
16203 return unify (tparms, targs,
16204 TYPE_PTRMEMFUNC_FN_TYPE (parm),
16205 TYPE_PTRMEMFUNC_FN_TYPE (arg),
16206 strict, explain_p);
16209 if (CLASSTYPE_TEMPLATE_INFO (parm))
16211 tree t = NULL_TREE;
16213 if (strict_in & UNIFY_ALLOW_DERIVED)
16215 /* First, we try to unify the PARM and ARG directly. */
16216 t = try_class_unification (tparms, targs,
16217 parm, arg, explain_p);
16221 /* Fallback to the special case allowed in
16222 [temp.deduct.call]:
16224 If P is a class, and P has the form
16225 template-id, then A can be a derived class of
16226 the deduced A. Likewise, if P is a pointer to
16227 a class of the form template-id, A can be a
16228 pointer to a derived class pointed to by the
16230 enum template_base_result r;
16231 r = get_template_base (tparms, targs, parm, arg,
16235 return unify_no_common_base (explain_p, r, parm, arg);
16238 else if (CLASSTYPE_TEMPLATE_INFO (arg)
16239 && (CLASSTYPE_TI_TEMPLATE (parm)
16240 == CLASSTYPE_TI_TEMPLATE (arg)))
16241 /* Perhaps PARM is something like S<U> and ARG is S<int>.
16242 Then, we should unify `int' and `U'. */
16245 /* There's no chance of unification succeeding. */
16246 return unify_type_mismatch (explain_p, parm, arg);
16248 return unify (tparms, targs, CLASSTYPE_TI_ARGS (parm),
16249 CLASSTYPE_TI_ARGS (t), UNIFY_ALLOW_NONE, explain_p);
16251 else if (!same_type_ignoring_top_level_qualifiers_p (parm, arg))
16252 return unify_type_mismatch (explain_p, parm, arg);
16253 return unify_success (explain_p);
16256 case FUNCTION_TYPE:
16258 unsigned int nargs;
16263 if (TREE_CODE (arg) != TREE_CODE (parm))
16264 return unify_type_mismatch (explain_p, parm, arg);
16266 /* CV qualifications for methods can never be deduced, they must
16267 match exactly. We need to check them explicitly here,
16268 because type_unification_real treats them as any other
16269 cv-qualified parameter. */
16270 if (TREE_CODE (parm) == METHOD_TYPE
16271 && (!check_cv_quals_for_unify
16273 class_of_this_parm (arg),
16274 class_of_this_parm (parm))))
16275 return unify_cv_qual_mismatch (explain_p, parm, arg);
16277 RECUR_AND_CHECK_FAILURE (tparms, targs, TREE_TYPE (parm),
16278 TREE_TYPE (arg), UNIFY_ALLOW_NONE, explain_p);
16280 nargs = list_length (TYPE_ARG_TYPES (arg));
16281 args = XALLOCAVEC (tree, nargs);
16282 for (a = TYPE_ARG_TYPES (arg), i = 0;
16283 a != NULL_TREE && a != void_list_node;
16284 a = TREE_CHAIN (a), ++i)
16285 args[i] = TREE_VALUE (a);
16288 return type_unification_real (tparms, targs, TYPE_ARG_TYPES (parm),
16289 args, nargs, 1, DEDUCE_EXACT,
16290 LOOKUP_NORMAL, explain_p);
16294 /* Unify a pointer to member with a pointer to member function, which
16295 deduces the type of the member as a function type. */
16296 if (TYPE_PTRMEMFUNC_P (arg))
16301 /* Check top-level cv qualifiers */
16302 if (!check_cv_quals_for_unify (UNIFY_ALLOW_NONE, arg, parm))
16303 return unify_cv_qual_mismatch (explain_p, parm, arg);
16305 RECUR_AND_CHECK_FAILURE (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
16306 TYPE_PTRMEMFUNC_OBJECT_TYPE (arg),
16307 UNIFY_ALLOW_NONE, explain_p);
16309 /* Determine the type of the function we are unifying against. */
16310 method_type = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (arg));
16312 build_function_type (TREE_TYPE (method_type),
16313 TREE_CHAIN (TYPE_ARG_TYPES (method_type)));
16315 /* Extract the cv-qualifiers of the member function from the
16316 implicit object parameter and place them on the function
16317 type to be restored later. */
16318 fntype = apply_memfn_quals (fntype, type_memfn_quals (method_type));
16319 return unify (tparms, targs, TREE_TYPE (parm), fntype, strict, explain_p);
16322 if (TREE_CODE (arg) != OFFSET_TYPE)
16323 return unify_type_mismatch (explain_p, parm, arg);
16324 RECUR_AND_CHECK_FAILURE (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
16325 TYPE_OFFSET_BASETYPE (arg),
16326 UNIFY_ALLOW_NONE, explain_p);
16327 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
16328 strict, explain_p);
16331 if (DECL_TEMPLATE_PARM_P (parm))
16332 return unify (tparms, targs, DECL_INITIAL (parm), arg, strict, explain_p);
16333 if (arg != integral_constant_value (parm))
16334 return unify_template_argument_mismatch (explain_p, parm, arg);
16335 return unify_success (explain_p);
16338 case TEMPLATE_DECL:
16339 /* Matched cases are handled by the ARG == PARM test above. */
16340 return unify_template_argument_mismatch (explain_p, parm, arg);
16343 /* A non-type template parameter that is a variable should be a
16344 an integral constant, in which case, it whould have been
16345 folded into its (constant) value. So we should not be getting
16346 a variable here. */
16347 gcc_unreachable ();
16349 case TYPE_ARGUMENT_PACK:
16350 case NONTYPE_ARGUMENT_PACK:
16352 tree packed_parms = ARGUMENT_PACK_ARGS (parm);
16353 tree packed_args = ARGUMENT_PACK_ARGS (arg);
16354 int i, len = TREE_VEC_LENGTH (packed_parms);
16355 int argslen = TREE_VEC_LENGTH (packed_args);
16356 int parm_variadic_p = 0;
16358 for (i = 0; i < len; ++i)
16360 if (PACK_EXPANSION_P (TREE_VEC_ELT (packed_parms, i)))
16363 /* We can unify against something with a trailing
16365 parm_variadic_p = 1;
16367 /* Since there is something following the pack
16368 expansion, we cannot unify this template argument
16370 return unify_success (explain_p);
16375 /* If we don't have enough arguments to satisfy the parameters
16376 (not counting the pack expression at the end), or we have
16377 too many arguments for a parameter list that doesn't end in
16378 a pack expression, we can't unify. */
16379 if (argslen < (len - parm_variadic_p))
16380 return unify_too_few_arguments (explain_p, argslen, len);
16381 if (argslen > len && !parm_variadic_p)
16382 return unify_too_many_arguments (explain_p, argslen, len);
16384 /* Unify all of the parameters that precede the (optional)
16385 pack expression. */
16386 for (i = 0; i < len - parm_variadic_p; ++i)
16388 RECUR_AND_CHECK_FAILURE (tparms, targs,
16389 TREE_VEC_ELT (packed_parms, i),
16390 TREE_VEC_ELT (packed_args, i),
16391 strict, explain_p);
16394 if (parm_variadic_p)
16395 return unify_pack_expansion (tparms, targs,
16396 packed_parms, packed_args,
16397 strict, /*call_args_p=*/false,
16398 /*subr=*/false, explain_p);
16399 return unify_success (explain_p);
16405 case DECLTYPE_TYPE:
16406 case UNDERLYING_TYPE:
16407 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
16408 or UNDERLYING_TYPE nodes. */
16409 return unify_success (explain_p);
16412 /* Unification fails if we hit an error node. */
16413 return unify_invalid (explain_p);
16416 /* An unresolved overload is a nondeduced context. */
16417 if (type_unknown_p (parm))
16418 return unify_success (explain_p);
16419 gcc_assert (EXPR_P (parm));
16421 /* We must be looking at an expression. This can happen with
16425 void foo(S<I>, S<I + 2>);
16427 This is a "nondeduced context":
16431 The nondeduced contexts are:
16433 --A type that is a template-id in which one or more of
16434 the template-arguments is an expression that references
16435 a template-parameter.
16437 In these cases, we assume deduction succeeded, but don't
16438 actually infer any unifications. */
16440 if (!uses_template_parms (parm)
16441 && !template_args_equal (parm, arg))
16442 return unify_expression_unequal (explain_p, parm, arg);
16444 return unify_success (explain_p);
16447 #undef RECUR_AND_CHECK_FAILURE
16449 /* Note that DECL can be defined in this translation unit, if
16453 mark_definable (tree decl)
16456 DECL_NOT_REALLY_EXTERN (decl) = 1;
16457 FOR_EACH_CLONE (clone, decl)
16458 DECL_NOT_REALLY_EXTERN (clone) = 1;
16461 /* Called if RESULT is explicitly instantiated, or is a member of an
16462 explicitly instantiated class. */
16465 mark_decl_instantiated (tree result, int extern_p)
16467 SET_DECL_EXPLICIT_INSTANTIATION (result);
16469 /* If this entity has already been written out, it's too late to
16470 make any modifications. */
16471 if (TREE_ASM_WRITTEN (result))
16474 if (TREE_CODE (result) != FUNCTION_DECL)
16475 /* The TREE_PUBLIC flag for function declarations will have been
16476 set correctly by tsubst. */
16477 TREE_PUBLIC (result) = 1;
16479 /* This might have been set by an earlier implicit instantiation. */
16480 DECL_COMDAT (result) = 0;
16483 DECL_NOT_REALLY_EXTERN (result) = 0;
16486 mark_definable (result);
16487 /* Always make artificials weak. */
16488 if (DECL_ARTIFICIAL (result) && flag_weak)
16489 comdat_linkage (result);
16490 /* For WIN32 we also want to put explicit instantiations in
16491 linkonce sections. */
16492 else if (TREE_PUBLIC (result))
16493 maybe_make_one_only (result);
16496 /* If EXTERN_P, then this function will not be emitted -- unless
16497 followed by an explicit instantiation, at which point its linkage
16498 will be adjusted. If !EXTERN_P, then this function will be
16499 emitted here. In neither circumstance do we want
16500 import_export_decl to adjust the linkage. */
16501 DECL_INTERFACE_KNOWN (result) = 1;
16504 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
16505 important template arguments. If any are missing, we check whether
16506 they're important by using error_mark_node for substituting into any
16507 args that were used for partial ordering (the ones between ARGS and END)
16508 and seeing if it bubbles up. */
16511 check_undeduced_parms (tree targs, tree args, tree end)
16513 bool found = false;
16515 for (i = TREE_VEC_LENGTH (targs) - 1; i >= 0; --i)
16516 if (TREE_VEC_ELT (targs, i) == NULL_TREE)
16519 TREE_VEC_ELT (targs, i) = error_mark_node;
16523 for (; args != end; args = TREE_CHAIN (args))
16525 tree substed = tsubst (TREE_VALUE (args), targs, tf_none, NULL_TREE);
16526 if (substed == error_mark_node)
16533 /* Given two function templates PAT1 and PAT2, return:
16535 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
16536 -1 if PAT2 is more specialized than PAT1.
16537 0 if neither is more specialized.
16539 LEN indicates the number of parameters we should consider
16540 (defaulted parameters should not be considered).
16542 The 1998 std underspecified function template partial ordering, and
16543 DR214 addresses the issue. We take pairs of arguments, one from
16544 each of the templates, and deduce them against each other. One of
16545 the templates will be more specialized if all the *other*
16546 template's arguments deduce against its arguments and at least one
16547 of its arguments *does* *not* deduce against the other template's
16548 corresponding argument. Deduction is done as for class templates.
16549 The arguments used in deduction have reference and top level cv
16550 qualifiers removed. Iff both arguments were originally reference
16551 types *and* deduction succeeds in both directions, the template
16552 with the more cv-qualified argument wins for that pairing (if
16553 neither is more cv-qualified, they both are equal). Unlike regular
16554 deduction, after all the arguments have been deduced in this way,
16555 we do *not* verify the deduced template argument values can be
16556 substituted into non-deduced contexts.
16558 The logic can be a bit confusing here, because we look at deduce1 and
16559 targs1 to see if pat2 is at least as specialized, and vice versa; if we
16560 can find template arguments for pat1 to make arg1 look like arg2, that
16561 means that arg2 is at least as specialized as arg1. */
16564 more_specialized_fn (tree pat1, tree pat2, int len)
16566 tree decl1 = DECL_TEMPLATE_RESULT (pat1);
16567 tree decl2 = DECL_TEMPLATE_RESULT (pat2);
16568 tree targs1 = make_tree_vec (DECL_NTPARMS (pat1));
16569 tree targs2 = make_tree_vec (DECL_NTPARMS (pat2));
16570 tree tparms1 = DECL_INNERMOST_TEMPLATE_PARMS (pat1);
16571 tree tparms2 = DECL_INNERMOST_TEMPLATE_PARMS (pat2);
16572 tree args1 = TYPE_ARG_TYPES (TREE_TYPE (decl1));
16573 tree args2 = TYPE_ARG_TYPES (TREE_TYPE (decl2));
16574 tree origs1, origs2;
16575 bool lose1 = false;
16576 bool lose2 = false;
16578 /* Remove the this parameter from non-static member functions. If
16579 one is a non-static member function and the other is not a static
16580 member function, remove the first parameter from that function
16581 also. This situation occurs for operator functions where we
16582 locate both a member function (with this pointer) and non-member
16583 operator (with explicit first operand). */
16584 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl1))
16586 len--; /* LEN is the number of significant arguments for DECL1 */
16587 args1 = TREE_CHAIN (args1);
16588 if (!DECL_STATIC_FUNCTION_P (decl2))
16589 args2 = TREE_CHAIN (args2);
16591 else if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl2))
16593 args2 = TREE_CHAIN (args2);
16594 if (!DECL_STATIC_FUNCTION_P (decl1))
16597 args1 = TREE_CHAIN (args1);
16601 /* If only one is a conversion operator, they are unordered. */
16602 if (DECL_CONV_FN_P (decl1) != DECL_CONV_FN_P (decl2))
16605 /* Consider the return type for a conversion function */
16606 if (DECL_CONV_FN_P (decl1))
16608 args1 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl1)), args1);
16609 args2 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl2)), args2);
16613 processing_template_decl++;
16619 /* Stop when an ellipsis is seen. */
16620 && args1 != NULL_TREE && args2 != NULL_TREE)
16622 tree arg1 = TREE_VALUE (args1);
16623 tree arg2 = TREE_VALUE (args2);
16624 int deduce1, deduce2;
16628 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
16629 && TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
16631 /* When both arguments are pack expansions, we need only
16632 unify the patterns themselves. */
16633 arg1 = PACK_EXPANSION_PATTERN (arg1);
16634 arg2 = PACK_EXPANSION_PATTERN (arg2);
16636 /* This is the last comparison we need to do. */
16640 if (TREE_CODE (arg1) == REFERENCE_TYPE)
16642 arg1 = TREE_TYPE (arg1);
16643 quals1 = cp_type_quals (arg1);
16646 if (TREE_CODE (arg2) == REFERENCE_TYPE)
16648 arg2 = TREE_TYPE (arg2);
16649 quals2 = cp_type_quals (arg2);
16652 if ((quals1 < 0) != (quals2 < 0))
16654 /* Only of the args is a reference, see if we should apply
16655 array/function pointer decay to it. This is not part of
16656 DR214, but is, IMHO, consistent with the deduction rules
16657 for the function call itself, and with our earlier
16658 implementation of the underspecified partial ordering
16659 rules. (nathan). */
16662 switch (TREE_CODE (arg1))
16665 arg1 = TREE_TYPE (arg1);
16667 case FUNCTION_TYPE:
16668 arg1 = build_pointer_type (arg1);
16677 switch (TREE_CODE (arg2))
16680 arg2 = TREE_TYPE (arg2);
16682 case FUNCTION_TYPE:
16683 arg2 = build_pointer_type (arg2);
16692 arg1 = TYPE_MAIN_VARIANT (arg1);
16693 arg2 = TYPE_MAIN_VARIANT (arg2);
16695 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION)
16697 int i, len2 = list_length (args2);
16698 tree parmvec = make_tree_vec (1);
16699 tree argvec = make_tree_vec (len2);
16702 /* Setup the parameter vector, which contains only ARG1. */
16703 TREE_VEC_ELT (parmvec, 0) = arg1;
16705 /* Setup the argument vector, which contains the remaining
16707 for (i = 0; i < len2; i++, ta = TREE_CHAIN (ta))
16708 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
16710 deduce1 = (unify_pack_expansion (tparms1, targs1, parmvec,
16711 argvec, UNIFY_ALLOW_NONE,
16712 /*call_args_p=*/false,
16713 /*subr=*/0, /*explain_p=*/false)
16716 /* We cannot deduce in the other direction, because ARG1 is
16717 a pack expansion but ARG2 is not. */
16720 else if (TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
16722 int i, len1 = list_length (args1);
16723 tree parmvec = make_tree_vec (1);
16724 tree argvec = make_tree_vec (len1);
16727 /* Setup the parameter vector, which contains only ARG1. */
16728 TREE_VEC_ELT (parmvec, 0) = arg2;
16730 /* Setup the argument vector, which contains the remaining
16732 for (i = 0; i < len1; i++, ta = TREE_CHAIN (ta))
16733 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
16735 deduce2 = (unify_pack_expansion (tparms2, targs2, parmvec,
16736 argvec, UNIFY_ALLOW_NONE,
16737 /*call_args_p=*/false,
16738 /*subr=*/0, /*explain_p=*/false)
16741 /* We cannot deduce in the other direction, because ARG2 is
16742 a pack expansion but ARG1 is not.*/
16748 /* The normal case, where neither argument is a pack
16750 deduce1 = (unify (tparms1, targs1, arg1, arg2,
16751 UNIFY_ALLOW_NONE, /*explain_p=*/false)
16753 deduce2 = (unify (tparms2, targs2, arg2, arg1,
16754 UNIFY_ALLOW_NONE, /*explain_p=*/false)
16758 /* If we couldn't deduce arguments for tparms1 to make arg1 match
16759 arg2, then arg2 is not as specialized as arg1. */
16765 /* "If, for a given type, deduction succeeds in both directions
16766 (i.e., the types are identical after the transformations above)
16767 and if the type from the argument template is more cv-qualified
16768 than the type from the parameter template (as described above)
16769 that type is considered to be more specialized than the other. If
16770 neither type is more cv-qualified than the other then neither type
16771 is more specialized than the other." */
16773 if (deduce1 && deduce2
16774 && quals1 != quals2 && quals1 >= 0 && quals2 >= 0)
16776 if ((quals1 & quals2) == quals2)
16778 if ((quals1 & quals2) == quals1)
16782 if (lose1 && lose2)
16783 /* We've failed to deduce something in either direction.
16784 These must be unordered. */
16787 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
16788 || TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
16789 /* We have already processed all of the arguments in our
16790 handing of the pack expansion type. */
16793 args1 = TREE_CHAIN (args1);
16794 args2 = TREE_CHAIN (args2);
16797 /* "In most cases, all template parameters must have values in order for
16798 deduction to succeed, but for partial ordering purposes a template
16799 parameter may remain without a value provided it is not used in the
16800 types being used for partial ordering."
16802 Thus, if we are missing any of the targs1 we need to substitute into
16803 origs1, then pat2 is not as specialized as pat1. This can happen when
16804 there is a nondeduced context. */
16805 if (!lose2 && check_undeduced_parms (targs1, origs1, args1))
16807 if (!lose1 && check_undeduced_parms (targs2, origs2, args2))
16810 processing_template_decl--;
16812 /* All things being equal, if the next argument is a pack expansion
16813 for one function but not for the other, prefer the
16814 non-variadic function. FIXME this is bogus; see c++/41958. */
16816 && args1 && TREE_VALUE (args1)
16817 && args2 && TREE_VALUE (args2))
16819 lose1 = TREE_CODE (TREE_VALUE (args1)) == TYPE_PACK_EXPANSION;
16820 lose2 = TREE_CODE (TREE_VALUE (args2)) == TYPE_PACK_EXPANSION;
16823 if (lose1 == lose2)
16831 /* Determine which of two partial specializations is more specialized.
16833 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
16834 to the first partial specialization. The TREE_VALUE is the
16835 innermost set of template parameters for the partial
16836 specialization. PAT2 is similar, but for the second template.
16838 Return 1 if the first partial specialization is more specialized;
16839 -1 if the second is more specialized; 0 if neither is more
16842 See [temp.class.order] for information about determining which of
16843 two templates is more specialized. */
16846 more_specialized_class (tree pat1, tree pat2)
16851 bool any_deductions = false;
16853 tmpl1 = TREE_TYPE (pat1);
16854 tmpl2 = TREE_TYPE (pat2);
16856 /* Just like what happens for functions, if we are ordering between
16857 different class template specializations, we may encounter dependent
16858 types in the arguments, and we need our dependency check functions
16859 to behave correctly. */
16860 ++processing_template_decl;
16861 targs = get_class_bindings (TREE_VALUE (pat1),
16862 CLASSTYPE_TI_ARGS (tmpl1),
16863 CLASSTYPE_TI_ARGS (tmpl2));
16867 any_deductions = true;
16870 targs = get_class_bindings (TREE_VALUE (pat2),
16871 CLASSTYPE_TI_ARGS (tmpl2),
16872 CLASSTYPE_TI_ARGS (tmpl1));
16876 any_deductions = true;
16878 --processing_template_decl;
16880 /* In the case of a tie where at least one of the class templates
16881 has a parameter pack at the end, the template with the most
16882 non-packed parameters wins. */
16885 && (template_args_variadic_p (TREE_PURPOSE (pat1))
16886 || template_args_variadic_p (TREE_PURPOSE (pat2))))
16888 tree args1 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat1));
16889 tree args2 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat2));
16890 int len1 = TREE_VEC_LENGTH (args1);
16891 int len2 = TREE_VEC_LENGTH (args2);
16893 /* We don't count the pack expansion at the end. */
16894 if (template_args_variadic_p (TREE_PURPOSE (pat1)))
16896 if (template_args_variadic_p (TREE_PURPOSE (pat2)))
16901 else if (len1 < len2)
16908 /* Return the template arguments that will produce the function signature
16909 DECL from the function template FN, with the explicit template
16910 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
16911 also match. Return NULL_TREE if no satisfactory arguments could be
16915 get_bindings (tree fn, tree decl, tree explicit_args, bool check_rettype)
16917 int ntparms = DECL_NTPARMS (fn);
16918 tree targs = make_tree_vec (ntparms);
16920 tree decl_arg_types;
16922 unsigned int nargs, ix;
16925 /* Substitute the explicit template arguments into the type of DECL.
16926 The call to fn_type_unification will handle substitution into the
16928 decl_type = TREE_TYPE (decl);
16929 if (explicit_args && uses_template_parms (decl_type))
16932 tree converted_args;
16934 if (DECL_TEMPLATE_INFO (decl))
16935 tmpl = DECL_TI_TEMPLATE (decl);
16937 /* We can get here for some invalid specializations. */
16941 = coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
16942 explicit_args, NULL_TREE,
16944 /*require_all_args=*/false,
16945 /*use_default_args=*/false);
16946 if (converted_args == error_mark_node)
16949 decl_type = tsubst (decl_type, converted_args, tf_none, NULL_TREE);
16950 if (decl_type == error_mark_node)
16954 /* Never do unification on the 'this' parameter. */
16955 decl_arg_types = skip_artificial_parms_for (decl,
16956 TYPE_ARG_TYPES (decl_type));
16958 nargs = list_length (decl_arg_types);
16959 args = XALLOCAVEC (tree, nargs);
16960 for (arg = decl_arg_types, ix = 0;
16961 arg != NULL_TREE && arg != void_list_node;
16962 arg = TREE_CHAIN (arg), ++ix)
16963 args[ix] = TREE_VALUE (arg);
16965 if (fn_type_unification (fn, explicit_args, targs,
16967 (check_rettype || DECL_CONV_FN_P (fn)
16968 ? TREE_TYPE (decl_type) : NULL_TREE),
16969 DEDUCE_EXACT, LOOKUP_NORMAL, /*explain_p=*/false))
16975 /* Return the innermost template arguments that, when applied to a
16976 template specialization whose innermost template parameters are
16977 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
16980 For example, suppose we have:
16982 template <class T, class U> struct S {};
16983 template <class T> struct S<T*, int> {};
16985 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
16986 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
16987 int}. The resulting vector will be {double}, indicating that `T'
16988 is bound to `double'. */
16991 get_class_bindings (tree tparms, tree spec_args, tree args)
16993 int i, ntparms = TREE_VEC_LENGTH (tparms);
16995 tree innermost_deduced_args;
16997 innermost_deduced_args = make_tree_vec (ntparms);
16998 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
17000 deduced_args = copy_node (args);
17001 SET_TMPL_ARGS_LEVEL (deduced_args,
17002 TMPL_ARGS_DEPTH (deduced_args),
17003 innermost_deduced_args);
17006 deduced_args = innermost_deduced_args;
17008 if (unify (tparms, deduced_args,
17009 INNERMOST_TEMPLATE_ARGS (spec_args),
17010 INNERMOST_TEMPLATE_ARGS (args),
17011 UNIFY_ALLOW_NONE, /*explain_p=*/false))
17014 for (i = 0; i < ntparms; ++i)
17015 if (! TREE_VEC_ELT (innermost_deduced_args, i))
17018 /* Verify that nondeduced template arguments agree with the type
17019 obtained from argument deduction.
17023 struct A { typedef int X; };
17024 template <class T, class U> struct C {};
17025 template <class T> struct C<T, typename T::X> {};
17027 Then with the instantiation `C<A, int>', we can deduce that
17028 `T' is `A' but unify () does not check whether `typename T::X'
17030 spec_args = tsubst (spec_args, deduced_args, tf_none, NULL_TREE);
17031 if (spec_args == error_mark_node
17032 /* We only need to check the innermost arguments; the other
17033 arguments will always agree. */
17034 || !comp_template_args (INNERMOST_TEMPLATE_ARGS (spec_args),
17035 INNERMOST_TEMPLATE_ARGS (args)))
17038 /* Now that we have bindings for all of the template arguments,
17039 ensure that the arguments deduced for the template template
17040 parameters have compatible template parameter lists. See the use
17041 of template_template_parm_bindings_ok_p in fn_type_unification
17042 for more information. */
17043 if (!template_template_parm_bindings_ok_p (tparms, deduced_args))
17046 return deduced_args;
17049 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
17050 Return the TREE_LIST node with the most specialized template, if
17051 any. If there is no most specialized template, the error_mark_node
17054 Note that this function does not look at, or modify, the
17055 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
17056 returned is one of the elements of INSTANTIATIONS, callers may
17057 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
17058 and retrieve it from the value returned. */
17061 most_specialized_instantiation (tree templates)
17065 ++processing_template_decl;
17068 for (fn = TREE_CHAIN (templates); fn; fn = TREE_CHAIN (fn))
17072 if (get_bindings (TREE_VALUE (champ),
17073 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
17074 NULL_TREE, /*check_ret=*/true))
17077 if (get_bindings (TREE_VALUE (fn),
17078 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
17079 NULL_TREE, /*check_ret=*/true))
17086 /* Equally specialized, move to next function. If there
17087 is no next function, nothing's most specialized. */
17088 fn = TREE_CHAIN (fn);
17096 /* Now verify that champ is better than everything earlier in the
17097 instantiation list. */
17098 for (fn = templates; fn != champ; fn = TREE_CHAIN (fn))
17099 if (get_bindings (TREE_VALUE (champ),
17100 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
17101 NULL_TREE, /*check_ret=*/true)
17102 || !get_bindings (TREE_VALUE (fn),
17103 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
17104 NULL_TREE, /*check_ret=*/true))
17110 processing_template_decl--;
17113 return error_mark_node;
17118 /* If DECL is a specialization of some template, return the most
17119 general such template. Otherwise, returns NULL_TREE.
17121 For example, given:
17123 template <class T> struct S { template <class U> void f(U); };
17125 if TMPL is `template <class U> void S<int>::f(U)' this will return
17126 the full template. This function will not trace past partial
17127 specializations, however. For example, given in addition:
17129 template <class T> struct S<T*> { template <class U> void f(U); };
17131 if TMPL is `template <class U> void S<int*>::f(U)' this will return
17132 `template <class T> template <class U> S<T*>::f(U)'. */
17135 most_general_template (tree decl)
17137 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
17138 an immediate specialization. */
17139 if (TREE_CODE (decl) == FUNCTION_DECL)
17141 if (DECL_TEMPLATE_INFO (decl)) {
17142 decl = DECL_TI_TEMPLATE (decl);
17144 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
17145 template friend. */
17146 if (TREE_CODE (decl) != TEMPLATE_DECL)
17152 /* Look for more and more general templates. */
17153 while (DECL_TEMPLATE_INFO (decl))
17155 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
17156 (See cp-tree.h for details.) */
17157 if (TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
17160 if (CLASS_TYPE_P (TREE_TYPE (decl))
17161 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)))
17164 /* Stop if we run into an explicitly specialized class template. */
17165 if (!DECL_NAMESPACE_SCOPE_P (decl)
17166 && DECL_CONTEXT (decl)
17167 && CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (decl)))
17170 decl = DECL_TI_TEMPLATE (decl);
17176 /* Return the most specialized of the class template partial
17177 specializations of TMPL which can produce TYPE, a specialization of
17178 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
17179 a _TYPE node corresponding to the partial specialization, while the
17180 TREE_PURPOSE is the set of template arguments that must be
17181 substituted into the TREE_TYPE in order to generate TYPE.
17183 If the choice of partial specialization is ambiguous, a diagnostic
17184 is issued, and the error_mark_node is returned. If there are no
17185 partial specializations of TMPL matching TYPE, then NULL_TREE is
17189 most_specialized_class (tree type, tree tmpl, tsubst_flags_t complain)
17191 tree list = NULL_TREE;
17197 tree outer_args = NULL_TREE;
17199 tmpl = most_general_template (tmpl);
17200 args = CLASSTYPE_TI_ARGS (type);
17202 /* For determining which partial specialization to use, only the
17203 innermost args are interesting. */
17204 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
17206 outer_args = strip_innermost_template_args (args, 1);
17207 args = INNERMOST_TEMPLATE_ARGS (args);
17210 for (t = DECL_TEMPLATE_SPECIALIZATIONS (tmpl); t; t = TREE_CHAIN (t))
17212 tree partial_spec_args;
17214 tree parms = TREE_VALUE (t);
17216 partial_spec_args = CLASSTYPE_TI_ARGS (TREE_TYPE (t));
17218 ++processing_template_decl;
17224 /* Discard the outer levels of args, and then substitute in the
17225 template args from the enclosing class. */
17226 partial_spec_args = INNERMOST_TEMPLATE_ARGS (partial_spec_args);
17227 partial_spec_args = tsubst_template_args
17228 (partial_spec_args, outer_args, tf_none, NULL_TREE);
17230 /* PARMS already refers to just the innermost parms, but the
17231 template parms in partial_spec_args had their levels lowered
17232 by tsubst, so we need to do the same for the parm list. We
17233 can't just tsubst the TREE_VEC itself, as tsubst wants to
17234 treat a TREE_VEC as an argument vector. */
17235 parms = copy_node (parms);
17236 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
17237 TREE_VEC_ELT (parms, i) =
17238 tsubst (TREE_VEC_ELT (parms, i), outer_args, tf_none, NULL_TREE);
17242 partial_spec_args =
17243 coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
17244 add_to_template_args (outer_args,
17245 partial_spec_args),
17247 /*require_all_args=*/true,
17248 /*use_default_args=*/true);
17250 --processing_template_decl;
17252 if (partial_spec_args == error_mark_node)
17253 return error_mark_node;
17255 spec_args = get_class_bindings (parms,
17261 spec_args = add_to_template_args (outer_args, spec_args);
17262 list = tree_cons (spec_args, TREE_VALUE (t), list);
17263 TREE_TYPE (list) = TREE_TYPE (t);
17270 ambiguous_p = false;
17273 t = TREE_CHAIN (t);
17274 for (; t; t = TREE_CHAIN (t))
17276 fate = more_specialized_class (champ, t);
17283 t = TREE_CHAIN (t);
17286 ambiguous_p = true;
17295 for (t = list; t && t != champ; t = TREE_CHAIN (t))
17297 fate = more_specialized_class (champ, t);
17300 ambiguous_p = true;
17308 char *spaces = NULL;
17309 if (!(complain & tf_error))
17310 return error_mark_node;
17311 error ("ambiguous class template instantiation for %q#T", type);
17312 str = ngettext ("candidate is:", "candidates are:", list_length (list));
17313 for (t = list; t; t = TREE_CHAIN (t))
17315 error ("%s %+#T", spaces ? spaces : str, TREE_TYPE (t));
17316 spaces = spaces ? spaces : get_spaces (str);
17319 return error_mark_node;
17325 /* Explicitly instantiate DECL. */
17328 do_decl_instantiation (tree decl, tree storage)
17330 tree result = NULL_TREE;
17333 if (!decl || decl == error_mark_node)
17334 /* An error occurred, for which grokdeclarator has already issued
17335 an appropriate message. */
17337 else if (! DECL_LANG_SPECIFIC (decl))
17339 error ("explicit instantiation of non-template %q#D", decl);
17342 else if (TREE_CODE (decl) == VAR_DECL)
17344 /* There is an asymmetry here in the way VAR_DECLs and
17345 FUNCTION_DECLs are handled by grokdeclarator. In the case of
17346 the latter, the DECL we get back will be marked as a
17347 template instantiation, and the appropriate
17348 DECL_TEMPLATE_INFO will be set up. This does not happen for
17349 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
17350 should handle VAR_DECLs as it currently handles
17352 if (!DECL_CLASS_SCOPE_P (decl))
17354 error ("%qD is not a static data member of a class template", decl);
17357 result = lookup_field (DECL_CONTEXT (decl), DECL_NAME (decl), 0, false);
17358 if (!result || TREE_CODE (result) != VAR_DECL)
17360 error ("no matching template for %qD found", decl);
17363 if (!same_type_p (TREE_TYPE (result), TREE_TYPE (decl)))
17365 error ("type %qT for explicit instantiation %qD does not match "
17366 "declared type %qT", TREE_TYPE (result), decl,
17371 else if (TREE_CODE (decl) != FUNCTION_DECL)
17373 error ("explicit instantiation of %q#D", decl);
17379 /* Check for various error cases. Note that if the explicit
17380 instantiation is valid the RESULT will currently be marked as an
17381 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
17382 until we get here. */
17384 if (DECL_TEMPLATE_SPECIALIZATION (result))
17386 /* DR 259 [temp.spec].
17388 Both an explicit instantiation and a declaration of an explicit
17389 specialization shall not appear in a program unless the explicit
17390 instantiation follows a declaration of the explicit specialization.
17392 For a given set of template parameters, if an explicit
17393 instantiation of a template appears after a declaration of an
17394 explicit specialization for that template, the explicit
17395 instantiation has no effect. */
17398 else if (DECL_EXPLICIT_INSTANTIATION (result))
17402 No program shall explicitly instantiate any template more
17405 We check DECL_NOT_REALLY_EXTERN so as not to complain when
17406 the first instantiation was `extern' and the second is not,
17407 and EXTERN_P for the opposite case. */
17408 if (DECL_NOT_REALLY_EXTERN (result) && !extern_p)
17409 permerror (input_location, "duplicate explicit instantiation of %q#D", result);
17410 /* If an "extern" explicit instantiation follows an ordinary
17411 explicit instantiation, the template is instantiated. */
17415 else if (!DECL_IMPLICIT_INSTANTIATION (result))
17417 error ("no matching template for %qD found", result);
17420 else if (!DECL_TEMPLATE_INFO (result))
17422 permerror (input_location, "explicit instantiation of non-template %q#D", result);
17426 if (storage == NULL_TREE)
17428 else if (storage == ridpointers[(int) RID_EXTERN])
17430 if (!in_system_header && (cxx_dialect == cxx98))
17431 pedwarn (input_location, OPT_pedantic,
17432 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
17437 error ("storage class %qD applied to template instantiation", storage);
17439 check_explicit_instantiation_namespace (result);
17440 mark_decl_instantiated (result, extern_p);
17442 instantiate_decl (result, /*defer_ok=*/1,
17443 /*expl_inst_class_mem_p=*/false);
17447 mark_class_instantiated (tree t, int extern_p)
17449 SET_CLASSTYPE_EXPLICIT_INSTANTIATION (t);
17450 SET_CLASSTYPE_INTERFACE_KNOWN (t);
17451 CLASSTYPE_INTERFACE_ONLY (t) = extern_p;
17452 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (t)) = extern_p;
17455 CLASSTYPE_DEBUG_REQUESTED (t) = 1;
17456 rest_of_type_compilation (t, 1);
17460 /* Called from do_type_instantiation through binding_table_foreach to
17461 do recursive instantiation for the type bound in ENTRY. */
17463 bt_instantiate_type_proc (binding_entry entry, void *data)
17465 tree storage = *(tree *) data;
17467 if (MAYBE_CLASS_TYPE_P (entry->type)
17468 && !uses_template_parms (CLASSTYPE_TI_ARGS (entry->type)))
17469 do_type_instantiation (TYPE_MAIN_DECL (entry->type), storage, 0);
17472 /* Called from do_type_instantiation to instantiate a member
17473 (a member function or a static member variable) of an
17474 explicitly instantiated class template. */
17476 instantiate_class_member (tree decl, int extern_p)
17478 mark_decl_instantiated (decl, extern_p);
17480 instantiate_decl (decl, /*defer_ok=*/1,
17481 /*expl_inst_class_mem_p=*/true);
17484 /* Perform an explicit instantiation of template class T. STORAGE, if
17485 non-null, is the RID for extern, inline or static. COMPLAIN is
17486 nonzero if this is called from the parser, zero if called recursively,
17487 since the standard is unclear (as detailed below). */
17490 do_type_instantiation (tree t, tree storage, tsubst_flags_t complain)
17495 int previous_instantiation_extern_p = 0;
17497 if (TREE_CODE (t) == TYPE_DECL)
17500 if (! CLASS_TYPE_P (t) || ! CLASSTYPE_TEMPLATE_INFO (t))
17502 error ("explicit instantiation of non-template type %qT", t);
17508 if (!COMPLETE_TYPE_P (t))
17510 if (complain & tf_error)
17511 error ("explicit instantiation of %q#T before definition of template",
17516 if (storage != NULL_TREE)
17518 if (!in_system_header)
17520 if (storage == ridpointers[(int) RID_EXTERN])
17522 if (cxx_dialect == cxx98)
17523 pedwarn (input_location, OPT_pedantic,
17524 "ISO C++ 1998 forbids the use of %<extern%> on "
17525 "explicit instantiations");
17528 pedwarn (input_location, OPT_pedantic,
17529 "ISO C++ forbids the use of %qE"
17530 " on explicit instantiations", storage);
17533 if (storage == ridpointers[(int) RID_INLINE])
17535 else if (storage == ridpointers[(int) RID_EXTERN])
17537 else if (storage == ridpointers[(int) RID_STATIC])
17541 error ("storage class %qD applied to template instantiation",
17547 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (t))
17549 /* DR 259 [temp.spec].
17551 Both an explicit instantiation and a declaration of an explicit
17552 specialization shall not appear in a program unless the explicit
17553 instantiation follows a declaration of the explicit specialization.
17555 For a given set of template parameters, if an explicit
17556 instantiation of a template appears after a declaration of an
17557 explicit specialization for that template, the explicit
17558 instantiation has no effect. */
17561 else if (CLASSTYPE_EXPLICIT_INSTANTIATION (t))
17565 No program shall explicitly instantiate any template more
17568 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
17569 instantiation was `extern'. If EXTERN_P then the second is.
17570 These cases are OK. */
17571 previous_instantiation_extern_p = CLASSTYPE_INTERFACE_ONLY (t);
17573 if (!previous_instantiation_extern_p && !extern_p
17574 && (complain & tf_error))
17575 permerror (input_location, "duplicate explicit instantiation of %q#T", t);
17577 /* If we've already instantiated the template, just return now. */
17578 if (!CLASSTYPE_INTERFACE_ONLY (t))
17582 check_explicit_instantiation_namespace (TYPE_NAME (t));
17583 mark_class_instantiated (t, extern_p);
17591 /* In contrast to implicit instantiation, where only the
17592 declarations, and not the definitions, of members are
17593 instantiated, we have here:
17597 The explicit instantiation of a class template specialization
17598 implies the instantiation of all of its members not
17599 previously explicitly specialized in the translation unit
17600 containing the explicit instantiation.
17602 Of course, we can't instantiate member template classes, since
17603 we don't have any arguments for them. Note that the standard
17604 is unclear on whether the instantiation of the members are
17605 *explicit* instantiations or not. However, the most natural
17606 interpretation is that it should be an explicit instantiation. */
17609 for (tmp = TYPE_METHODS (t); tmp; tmp = DECL_CHAIN (tmp))
17610 if (TREE_CODE (tmp) == FUNCTION_DECL
17611 && DECL_TEMPLATE_INSTANTIATION (tmp))
17612 instantiate_class_member (tmp, extern_p);
17614 for (tmp = TYPE_FIELDS (t); tmp; tmp = DECL_CHAIN (tmp))
17615 if (TREE_CODE (tmp) == VAR_DECL && DECL_TEMPLATE_INSTANTIATION (tmp))
17616 instantiate_class_member (tmp, extern_p);
17618 if (CLASSTYPE_NESTED_UTDS (t))
17619 binding_table_foreach (CLASSTYPE_NESTED_UTDS (t),
17620 bt_instantiate_type_proc, &storage);
17624 /* Given a function DECL, which is a specialization of TMPL, modify
17625 DECL to be a re-instantiation of TMPL with the same template
17626 arguments. TMPL should be the template into which tsubst'ing
17627 should occur for DECL, not the most general template.
17629 One reason for doing this is a scenario like this:
17632 void f(const T&, int i);
17634 void g() { f(3, 7); }
17637 void f(const T& t, const int i) { }
17639 Note that when the template is first instantiated, with
17640 instantiate_template, the resulting DECL will have no name for the
17641 first parameter, and the wrong type for the second. So, when we go
17642 to instantiate the DECL, we regenerate it. */
17645 regenerate_decl_from_template (tree decl, tree tmpl)
17647 /* The arguments used to instantiate DECL, from the most general
17652 args = DECL_TI_ARGS (decl);
17653 code_pattern = DECL_TEMPLATE_RESULT (tmpl);
17655 /* Make sure that we can see identifiers, and compute access
17657 push_access_scope (decl);
17659 if (TREE_CODE (decl) == FUNCTION_DECL)
17667 args_depth = TMPL_ARGS_DEPTH (args);
17668 parms_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
17669 if (args_depth > parms_depth)
17670 args = get_innermost_template_args (args, parms_depth);
17672 specs = tsubst_exception_specification (TREE_TYPE (code_pattern),
17673 args, tf_error, NULL_TREE,
17674 /*defer_ok*/false);
17676 TREE_TYPE (decl) = build_exception_variant (TREE_TYPE (decl),
17679 /* Merge parameter declarations. */
17680 decl_parm = skip_artificial_parms_for (decl,
17681 DECL_ARGUMENTS (decl));
17683 = skip_artificial_parms_for (code_pattern,
17684 DECL_ARGUMENTS (code_pattern));
17685 while (decl_parm && !FUNCTION_PARAMETER_PACK_P (pattern_parm))
17690 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
17691 DECL_NAME (decl_parm) = DECL_NAME (pattern_parm);
17692 parm_type = tsubst (TREE_TYPE (pattern_parm), args, tf_error,
17694 parm_type = type_decays_to (parm_type);
17695 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
17696 TREE_TYPE (decl_parm) = parm_type;
17697 attributes = DECL_ATTRIBUTES (pattern_parm);
17698 if (DECL_ATTRIBUTES (decl_parm) != attributes)
17700 DECL_ATTRIBUTES (decl_parm) = attributes;
17701 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
17703 decl_parm = DECL_CHAIN (decl_parm);
17704 pattern_parm = DECL_CHAIN (pattern_parm);
17706 /* Merge any parameters that match with the function parameter
17708 if (pattern_parm && FUNCTION_PARAMETER_PACK_P (pattern_parm))
17711 tree expanded_types;
17712 /* Expand the TYPE_PACK_EXPANSION that provides the types for
17713 the parameters in this function parameter pack. */
17714 expanded_types = tsubst_pack_expansion (TREE_TYPE (pattern_parm),
17715 args, tf_error, NULL_TREE);
17716 len = TREE_VEC_LENGTH (expanded_types);
17717 for (i = 0; i < len; i++)
17722 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
17723 /* Rename the parameter to include the index. */
17724 DECL_NAME (decl_parm) =
17725 make_ith_pack_parameter_name (DECL_NAME (pattern_parm), i);
17726 parm_type = TREE_VEC_ELT (expanded_types, i);
17727 parm_type = type_decays_to (parm_type);
17728 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
17729 TREE_TYPE (decl_parm) = parm_type;
17730 attributes = DECL_ATTRIBUTES (pattern_parm);
17731 if (DECL_ATTRIBUTES (decl_parm) != attributes)
17733 DECL_ATTRIBUTES (decl_parm) = attributes;
17734 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
17736 decl_parm = DECL_CHAIN (decl_parm);
17739 /* Merge additional specifiers from the CODE_PATTERN. */
17740 if (DECL_DECLARED_INLINE_P (code_pattern)
17741 && !DECL_DECLARED_INLINE_P (decl))
17742 DECL_DECLARED_INLINE_P (decl) = 1;
17744 else if (TREE_CODE (decl) == VAR_DECL)
17746 DECL_INITIAL (decl) =
17747 tsubst_expr (DECL_INITIAL (code_pattern), args,
17748 tf_error, DECL_TI_TEMPLATE (decl),
17749 /*integral_constant_expression_p=*/false);
17750 if (VAR_HAD_UNKNOWN_BOUND (decl))
17751 TREE_TYPE (decl) = tsubst (TREE_TYPE (code_pattern), args,
17752 tf_error, DECL_TI_TEMPLATE (decl));
17755 gcc_unreachable ();
17757 pop_access_scope (decl);
17760 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
17761 substituted to get DECL. */
17764 template_for_substitution (tree decl)
17766 tree tmpl = DECL_TI_TEMPLATE (decl);
17768 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
17769 for the instantiation. This is not always the most general
17770 template. Consider, for example:
17773 struct S { template <class U> void f();
17774 template <> void f<int>(); };
17776 and an instantiation of S<double>::f<int>. We want TD to be the
17777 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
17778 while (/* An instantiation cannot have a definition, so we need a
17779 more general template. */
17780 DECL_TEMPLATE_INSTANTIATION (tmpl)
17781 /* We must also deal with friend templates. Given:
17783 template <class T> struct S {
17784 template <class U> friend void f() {};
17787 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
17788 so far as the language is concerned, but that's still
17789 where we get the pattern for the instantiation from. On
17790 other hand, if the definition comes outside the class, say:
17792 template <class T> struct S {
17793 template <class U> friend void f();
17795 template <class U> friend void f() {}
17797 we don't need to look any further. That's what the check for
17798 DECL_INITIAL is for. */
17799 || (TREE_CODE (decl) == FUNCTION_DECL
17800 && DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION (tmpl)
17801 && !DECL_INITIAL (DECL_TEMPLATE_RESULT (tmpl))))
17803 /* The present template, TD, should not be a definition. If it
17804 were a definition, we should be using it! Note that we
17805 cannot restructure the loop to just keep going until we find
17806 a template with a definition, since that might go too far if
17807 a specialization was declared, but not defined. */
17808 gcc_assert (TREE_CODE (decl) != VAR_DECL
17809 || DECL_IN_AGGR_P (DECL_TEMPLATE_RESULT (tmpl)));
17811 /* Fetch the more general template. */
17812 tmpl = DECL_TI_TEMPLATE (tmpl);
17818 /* Returns true if we need to instantiate this template instance even if we
17819 know we aren't going to emit it.. */
17822 always_instantiate_p (tree decl)
17824 /* We always instantiate inline functions so that we can inline them. An
17825 explicit instantiation declaration prohibits implicit instantiation of
17826 non-inline functions. With high levels of optimization, we would
17827 normally inline non-inline functions -- but we're not allowed to do
17828 that for "extern template" functions. Therefore, we check
17829 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
17830 return ((TREE_CODE (decl) == FUNCTION_DECL
17831 && DECL_DECLARED_INLINE_P (decl))
17832 /* And we need to instantiate static data members so that
17833 their initializers are available in integral constant
17835 || (TREE_CODE (decl) == VAR_DECL
17836 && decl_maybe_constant_var_p (decl)));
17839 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
17840 instantiate it now, modifying TREE_TYPE (fn). */
17843 maybe_instantiate_noexcept (tree fn)
17845 tree fntype, spec, noex, clone;
17847 if (DECL_CLONED_FUNCTION_P (fn))
17848 fn = DECL_CLONED_FUNCTION (fn);
17849 fntype = TREE_TYPE (fn);
17850 spec = TYPE_RAISES_EXCEPTIONS (fntype);
17852 if (!DEFERRED_NOEXCEPT_SPEC_P (spec))
17855 noex = TREE_PURPOSE (spec);
17857 if (TREE_CODE (noex) == DEFERRED_NOEXCEPT)
17859 push_tinst_level (fn);
17860 push_access_scope (fn);
17861 input_location = DECL_SOURCE_LOCATION (fn);
17862 noex = tsubst_copy_and_build (DEFERRED_NOEXCEPT_PATTERN (noex),
17863 DEFERRED_NOEXCEPT_ARGS (noex),
17864 tf_warning_or_error, fn, /*function_p=*/false,
17865 /*integral_constant_expression_p=*/true);
17866 pop_access_scope (fn);
17867 pop_tinst_level ();
17868 spec = build_noexcept_spec (noex, tf_warning_or_error);
17869 if (spec == error_mark_node)
17870 spec = noexcept_false_spec;
17874 /* This is an implicitly declared function, so NOEX is a list of
17875 other functions to evaluate and merge. */
17877 spec = noexcept_true_spec;
17878 for (elt = noex; elt; elt = OVL_NEXT (elt))
17880 tree fn = OVL_CURRENT (elt);
17882 maybe_instantiate_noexcept (fn);
17883 subspec = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (fn));
17884 spec = merge_exception_specifiers (spec, subspec, NULL_TREE);
17888 TREE_TYPE (fn) = build_exception_variant (fntype, spec);
17890 FOR_EACH_CLONE (clone, fn)
17892 if (TREE_TYPE (clone) == fntype)
17893 TREE_TYPE (clone) = TREE_TYPE (fn);
17895 TREE_TYPE (clone) = build_exception_variant (TREE_TYPE (clone), spec);
17899 /* Produce the definition of D, a _DECL generated from a template. If
17900 DEFER_OK is nonzero, then we don't have to actually do the
17901 instantiation now; we just have to do it sometime. Normally it is
17902 an error if this is an explicit instantiation but D is undefined.
17903 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
17904 explicitly instantiated class template. */
17907 instantiate_decl (tree d, int defer_ok,
17908 bool expl_inst_class_mem_p)
17910 tree tmpl = DECL_TI_TEMPLATE (d);
17917 bool pattern_defined;
17919 location_t saved_loc = input_location;
17922 /* This function should only be used to instantiate templates for
17923 functions and static member variables. */
17924 gcc_assert (TREE_CODE (d) == FUNCTION_DECL
17925 || TREE_CODE (d) == VAR_DECL);
17927 /* Variables are never deferred; if instantiation is required, they
17928 are instantiated right away. That allows for better code in the
17929 case that an expression refers to the value of the variable --
17930 if the variable has a constant value the referring expression can
17931 take advantage of that fact. */
17932 if (TREE_CODE (d) == VAR_DECL
17933 || DECL_DECLARED_CONSTEXPR_P (d))
17936 /* Don't instantiate cloned functions. Instead, instantiate the
17937 functions they cloned. */
17938 if (TREE_CODE (d) == FUNCTION_DECL && DECL_CLONED_FUNCTION_P (d))
17939 d = DECL_CLONED_FUNCTION (d);
17941 if (DECL_TEMPLATE_INSTANTIATED (d)
17942 || DECL_TEMPLATE_SPECIALIZATION (d))
17943 /* D has already been instantiated or explicitly specialized, so
17944 there's nothing for us to do here.
17946 It might seem reasonable to check whether or not D is an explicit
17947 instantiation, and, if so, stop here. But when an explicit
17948 instantiation is deferred until the end of the compilation,
17949 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
17950 the instantiation. */
17953 /* Check to see whether we know that this template will be
17954 instantiated in some other file, as with "extern template"
17956 external_p = (DECL_INTERFACE_KNOWN (d) && DECL_REALLY_EXTERN (d));
17958 /* In general, we do not instantiate such templates. */
17959 if (external_p && !always_instantiate_p (d))
17962 gen_tmpl = most_general_template (tmpl);
17963 gen_args = DECL_TI_ARGS (d);
17965 if (tmpl != gen_tmpl)
17966 /* We should already have the extra args. */
17967 gcc_assert (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (gen_tmpl))
17968 == TMPL_ARGS_DEPTH (gen_args));
17969 /* And what's in the hash table should match D. */
17970 gcc_assert ((spec = retrieve_specialization (gen_tmpl, gen_args, 0)) == d
17971 || spec == NULL_TREE);
17973 /* This needs to happen before any tsubsting. */
17974 if (! push_tinst_level (d))
17977 timevar_push (TV_TEMPLATE_INST);
17979 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
17980 for the instantiation. */
17981 td = template_for_substitution (d);
17982 code_pattern = DECL_TEMPLATE_RESULT (td);
17984 /* We should never be trying to instantiate a member of a class
17985 template or partial specialization. */
17986 gcc_assert (d != code_pattern);
17988 if ((DECL_NAMESPACE_SCOPE_P (d) && !DECL_INITIALIZED_IN_CLASS_P (d))
17989 || DECL_TEMPLATE_SPECIALIZATION (td))
17990 /* In the case of a friend template whose definition is provided
17991 outside the class, we may have too many arguments. Drop the
17992 ones we don't need. The same is true for specializations. */
17993 args = get_innermost_template_args
17994 (gen_args, TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (td)));
17998 if (TREE_CODE (d) == FUNCTION_DECL)
17999 pattern_defined = (DECL_SAVED_TREE (code_pattern) != NULL_TREE
18000 || DECL_DEFAULTED_OUTSIDE_CLASS_P (code_pattern));
18002 pattern_defined = ! DECL_IN_AGGR_P (code_pattern);
18004 /* We may be in the middle of deferred access check. Disable it now. */
18005 push_deferring_access_checks (dk_no_deferred);
18007 /* Unless an explicit instantiation directive has already determined
18008 the linkage of D, remember that a definition is available for
18010 if (pattern_defined
18011 && !DECL_INTERFACE_KNOWN (d)
18012 && !DECL_NOT_REALLY_EXTERN (d))
18013 mark_definable (d);
18015 DECL_SOURCE_LOCATION (td) = DECL_SOURCE_LOCATION (code_pattern);
18016 DECL_SOURCE_LOCATION (d) = DECL_SOURCE_LOCATION (code_pattern);
18017 input_location = DECL_SOURCE_LOCATION (d);
18019 /* If D is a member of an explicitly instantiated class template,
18020 and no definition is available, treat it like an implicit
18022 if (!pattern_defined && expl_inst_class_mem_p
18023 && DECL_EXPLICIT_INSTANTIATION (d))
18025 /* Leave linkage flags alone on instantiations with anonymous
18027 if (TREE_PUBLIC (d))
18029 DECL_NOT_REALLY_EXTERN (d) = 0;
18030 DECL_INTERFACE_KNOWN (d) = 0;
18032 SET_DECL_IMPLICIT_INSTANTIATION (d);
18035 if (TREE_CODE (d) == FUNCTION_DECL)
18036 maybe_instantiate_noexcept (d);
18038 /* Recheck the substitutions to obtain any warning messages
18039 about ignoring cv qualifiers. Don't do this for artificial decls,
18040 as it breaks the context-sensitive substitution for lambda op(). */
18041 if (!defer_ok && !DECL_ARTIFICIAL (d))
18043 tree gen = DECL_TEMPLATE_RESULT (gen_tmpl);
18044 tree type = TREE_TYPE (gen);
18046 /* Make sure that we can see identifiers, and compute access
18047 correctly. D is already the target FUNCTION_DECL with the
18049 push_access_scope (d);
18051 if (TREE_CODE (gen) == FUNCTION_DECL)
18053 tsubst (DECL_ARGUMENTS (gen), gen_args, tf_warning_or_error, d);
18054 tsubst_exception_specification (type, gen_args, tf_warning_or_error,
18055 d, /*defer_ok*/true);
18056 /* Don't simply tsubst the function type, as that will give
18057 duplicate warnings about poor parameter qualifications.
18058 The function arguments are the same as the decl_arguments
18059 without the top level cv qualifiers. */
18060 type = TREE_TYPE (type);
18062 tsubst (type, gen_args, tf_warning_or_error, d);
18064 pop_access_scope (d);
18067 /* Defer all other templates, unless we have been explicitly
18068 forbidden from doing so. */
18069 if (/* If there is no definition, we cannot instantiate the
18072 /* If it's OK to postpone instantiation, do so. */
18074 /* If this is a static data member that will be defined
18075 elsewhere, we don't want to instantiate the entire data
18076 member, but we do want to instantiate the initializer so that
18077 we can substitute that elsewhere. */
18078 || (external_p && TREE_CODE (d) == VAR_DECL))
18080 /* The definition of the static data member is now required so
18081 we must substitute the initializer. */
18082 if (TREE_CODE (d) == VAR_DECL
18083 && !DECL_INITIAL (d)
18084 && DECL_INITIAL (code_pattern))
18088 bool const_init = false;
18090 ns = decl_namespace_context (d);
18091 push_nested_namespace (ns);
18092 push_nested_class (DECL_CONTEXT (d));
18093 init = tsubst_expr (DECL_INITIAL (code_pattern),
18095 tf_warning_or_error, NULL_TREE,
18096 /*integral_constant_expression_p=*/false);
18097 /* Make sure the initializer is still constant, in case of
18098 circular dependency (template/instantiate6.C). */
18100 = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (code_pattern);
18101 cp_finish_decl (d, init, /*init_const_expr_p=*/const_init,
18102 /*asmspec_tree=*/NULL_TREE,
18103 LOOKUP_ONLYCONVERTING);
18104 pop_nested_class ();
18105 pop_nested_namespace (ns);
18108 /* We restore the source position here because it's used by
18109 add_pending_template. */
18110 input_location = saved_loc;
18112 if (at_eof && !pattern_defined
18113 && DECL_EXPLICIT_INSTANTIATION (d)
18114 && DECL_NOT_REALLY_EXTERN (d))
18117 The definition of a non-exported function template, a
18118 non-exported member function template, or a non-exported
18119 member function or static data member of a class template
18120 shall be present in every translation unit in which it is
18121 explicitly instantiated. */
18122 permerror (input_location, "explicit instantiation of %qD "
18123 "but no definition available", d);
18125 /* If we're in unevaluated context, we just wanted to get the
18126 constant value; this isn't an odr use, so don't queue
18127 a full instantiation. */
18128 if (cp_unevaluated_operand != 0)
18130 /* ??? Historically, we have instantiated inline functions, even
18131 when marked as "extern template". */
18132 if (!(external_p && TREE_CODE (d) == VAR_DECL))
18133 add_pending_template (d);
18136 /* Tell the repository that D is available in this translation unit
18137 -- and see if it is supposed to be instantiated here. */
18138 if (TREE_PUBLIC (d) && !DECL_REALLY_EXTERN (d) && !repo_emit_p (d))
18140 /* In a PCH file, despite the fact that the repository hasn't
18141 requested instantiation in the PCH it is still possible that
18142 an instantiation will be required in a file that includes the
18145 add_pending_template (d);
18146 /* Instantiate inline functions so that the inliner can do its
18147 job, even though we'll not be emitting a copy of this
18149 if (!(TREE_CODE (d) == FUNCTION_DECL && possibly_inlined_p (d)))
18153 need_push = !cfun || !global_bindings_p ();
18155 push_to_top_level ();
18157 /* Mark D as instantiated so that recursive calls to
18158 instantiate_decl do not try to instantiate it again. */
18159 DECL_TEMPLATE_INSTANTIATED (d) = 1;
18161 /* Regenerate the declaration in case the template has been modified
18162 by a subsequent redeclaration. */
18163 regenerate_decl_from_template (d, td);
18165 /* We already set the file and line above. Reset them now in case
18166 they changed as a result of calling regenerate_decl_from_template. */
18167 input_location = DECL_SOURCE_LOCATION (d);
18169 if (TREE_CODE (d) == VAR_DECL)
18172 bool const_init = false;
18174 /* Clear out DECL_RTL; whatever was there before may not be right
18175 since we've reset the type of the declaration. */
18176 SET_DECL_RTL (d, NULL);
18177 DECL_IN_AGGR_P (d) = 0;
18179 /* The initializer is placed in DECL_INITIAL by
18180 regenerate_decl_from_template so we don't need to
18181 push/pop_access_scope again here. Pull it out so that
18182 cp_finish_decl can process it. */
18183 init = DECL_INITIAL (d);
18184 DECL_INITIAL (d) = NULL_TREE;
18185 DECL_INITIALIZED_P (d) = 0;
18187 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
18188 initializer. That function will defer actual emission until
18189 we have a chance to determine linkage. */
18190 DECL_EXTERNAL (d) = 0;
18192 /* Enter the scope of D so that access-checking works correctly. */
18193 push_nested_class (DECL_CONTEXT (d));
18194 const_init = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (code_pattern);
18195 cp_finish_decl (d, init, const_init, NULL_TREE, 0);
18196 pop_nested_class ();
18198 else if (TREE_CODE (d) == FUNCTION_DECL && DECL_DEFAULTED_FN (code_pattern))
18199 synthesize_method (d);
18200 else if (TREE_CODE (d) == FUNCTION_DECL)
18202 htab_t saved_local_specializations;
18207 /* Save away the current list, in case we are instantiating one
18208 template from within the body of another. */
18209 saved_local_specializations = local_specializations;
18211 /* Set up the list of local specializations. */
18212 local_specializations = htab_create (37,
18213 hash_local_specialization,
18214 eq_local_specializations,
18217 /* Set up context. */
18218 start_preparsed_function (d, NULL_TREE, SF_PRE_PARSED);
18220 /* Create substitution entries for the parameters. */
18221 subst_decl = DECL_TEMPLATE_RESULT (template_for_substitution (d));
18222 tmpl_parm = DECL_ARGUMENTS (subst_decl);
18223 spec_parm = DECL_ARGUMENTS (d);
18224 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (d))
18226 register_local_specialization (spec_parm, tmpl_parm);
18227 spec_parm = skip_artificial_parms_for (d, spec_parm);
18228 tmpl_parm = skip_artificial_parms_for (subst_decl, tmpl_parm);
18230 for (; tmpl_parm; tmpl_parm = DECL_CHAIN (tmpl_parm))
18232 if (!FUNCTION_PARAMETER_PACK_P (tmpl_parm))
18234 register_local_specialization (spec_parm, tmpl_parm);
18235 spec_parm = DECL_CHAIN (spec_parm);
18239 /* Register the (value) argument pack as a specialization of
18240 TMPL_PARM, then move on. */
18241 tree argpack = extract_fnparm_pack (tmpl_parm, &spec_parm);
18242 register_local_specialization (argpack, tmpl_parm);
18245 gcc_assert (!spec_parm);
18247 /* Substitute into the body of the function. */
18248 tsubst_expr (DECL_SAVED_TREE (code_pattern), args,
18249 tf_warning_or_error, tmpl,
18250 /*integral_constant_expression_p=*/false);
18252 /* Set the current input_location to the end of the function
18253 so that finish_function knows where we are. */
18254 input_location = DECL_STRUCT_FUNCTION (code_pattern)->function_end_locus;
18256 /* We don't need the local specializations any more. */
18257 htab_delete (local_specializations);
18258 local_specializations = saved_local_specializations;
18260 /* Finish the function. */
18261 d = finish_function (0);
18262 expand_or_defer_fn (d);
18265 /* We're not deferring instantiation any more. */
18266 TI_PENDING_TEMPLATE_FLAG (DECL_TEMPLATE_INFO (d)) = 0;
18269 pop_from_top_level ();
18272 input_location = saved_loc;
18273 pop_deferring_access_checks ();
18274 pop_tinst_level ();
18276 timevar_pop (TV_TEMPLATE_INST);
18281 /* Run through the list of templates that we wish we could
18282 instantiate, and instantiate any we can. RETRIES is the
18283 number of times we retry pending template instantiation. */
18286 instantiate_pending_templates (int retries)
18289 location_t saved_loc = input_location;
18291 /* Instantiating templates may trigger vtable generation. This in turn
18292 may require further template instantiations. We place a limit here
18293 to avoid infinite loop. */
18294 if (pending_templates && retries >= max_tinst_depth)
18296 tree decl = pending_templates->tinst->decl;
18298 error ("template instantiation depth exceeds maximum of %d"
18299 " instantiating %q+D, possibly from virtual table generation"
18300 " (use -ftemplate-depth= to increase the maximum)",
18301 max_tinst_depth, decl);
18302 if (TREE_CODE (decl) == FUNCTION_DECL)
18303 /* Pretend that we defined it. */
18304 DECL_INITIAL (decl) = error_mark_node;
18310 struct pending_template **t = &pending_templates;
18311 struct pending_template *last = NULL;
18315 tree instantiation = reopen_tinst_level ((*t)->tinst);
18316 bool complete = false;
18318 if (TYPE_P (instantiation))
18322 if (!COMPLETE_TYPE_P (instantiation))
18324 instantiate_class_template (instantiation);
18325 if (CLASSTYPE_TEMPLATE_INSTANTIATION (instantiation))
18326 for (fn = TYPE_METHODS (instantiation);
18328 fn = TREE_CHAIN (fn))
18329 if (! DECL_ARTIFICIAL (fn))
18330 instantiate_decl (fn,
18332 /*expl_inst_class_mem_p=*/false);
18333 if (COMPLETE_TYPE_P (instantiation))
18337 complete = COMPLETE_TYPE_P (instantiation);
18341 if (!DECL_TEMPLATE_SPECIALIZATION (instantiation)
18342 && !DECL_TEMPLATE_INSTANTIATED (instantiation))
18345 = instantiate_decl (instantiation,
18347 /*expl_inst_class_mem_p=*/false);
18348 if (DECL_TEMPLATE_INSTANTIATED (instantiation))
18352 complete = (DECL_TEMPLATE_SPECIALIZATION (instantiation)
18353 || DECL_TEMPLATE_INSTANTIATED (instantiation));
18357 /* If INSTANTIATION has been instantiated, then we don't
18358 need to consider it again in the future. */
18366 current_tinst_level = NULL;
18368 last_pending_template = last;
18370 while (reconsider);
18372 input_location = saved_loc;
18375 /* Substitute ARGVEC into T, which is a list of initializers for
18376 either base class or a non-static data member. The TREE_PURPOSEs
18377 are DECLs, and the TREE_VALUEs are the initializer values. Used by
18378 instantiate_decl. */
18381 tsubst_initializer_list (tree t, tree argvec)
18383 tree inits = NULL_TREE;
18385 for (; t; t = TREE_CHAIN (t))
18389 tree expanded_bases = NULL_TREE;
18390 tree expanded_arguments = NULL_TREE;
18393 if (TREE_CODE (TREE_PURPOSE (t)) == TYPE_PACK_EXPANSION)
18398 /* Expand the base class expansion type into separate base
18400 expanded_bases = tsubst_pack_expansion (TREE_PURPOSE (t), argvec,
18401 tf_warning_or_error,
18403 if (expanded_bases == error_mark_node)
18406 /* We'll be building separate TREE_LISTs of arguments for
18408 len = TREE_VEC_LENGTH (expanded_bases);
18409 expanded_arguments = make_tree_vec (len);
18410 for (i = 0; i < len; i++)
18411 TREE_VEC_ELT (expanded_arguments, i) = NULL_TREE;
18413 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
18414 expand each argument in the TREE_VALUE of t. */
18415 expr = make_node (EXPR_PACK_EXPANSION);
18416 PACK_EXPANSION_PARAMETER_PACKS (expr) =
18417 PACK_EXPANSION_PARAMETER_PACKS (TREE_PURPOSE (t));
18419 if (TREE_VALUE (t) == void_type_node)
18420 /* VOID_TYPE_NODE is used to indicate
18421 value-initialization. */
18423 for (i = 0; i < len; i++)
18424 TREE_VEC_ELT (expanded_arguments, i) = void_type_node;
18428 /* Substitute parameter packs into each argument in the
18430 in_base_initializer = 1;
18431 for (arg = TREE_VALUE (t); arg; arg = TREE_CHAIN (arg))
18433 tree expanded_exprs;
18435 /* Expand the argument. */
18436 SET_PACK_EXPANSION_PATTERN (expr, TREE_VALUE (arg));
18438 = tsubst_pack_expansion (expr, argvec,
18439 tf_warning_or_error,
18441 if (expanded_exprs == error_mark_node)
18444 /* Prepend each of the expanded expressions to the
18445 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
18446 for (i = 0; i < len; i++)
18448 TREE_VEC_ELT (expanded_arguments, i) =
18449 tree_cons (NULL_TREE,
18450 TREE_VEC_ELT (expanded_exprs, i),
18451 TREE_VEC_ELT (expanded_arguments, i));
18454 in_base_initializer = 0;
18456 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
18457 since we built them backwards. */
18458 for (i = 0; i < len; i++)
18460 TREE_VEC_ELT (expanded_arguments, i) =
18461 nreverse (TREE_VEC_ELT (expanded_arguments, i));
18466 for (i = 0; i < len; ++i)
18468 if (expanded_bases)
18470 decl = TREE_VEC_ELT (expanded_bases, i);
18471 decl = expand_member_init (decl);
18472 init = TREE_VEC_ELT (expanded_arguments, i);
18476 decl = tsubst_copy (TREE_PURPOSE (t), argvec,
18477 tf_warning_or_error, NULL_TREE);
18479 decl = expand_member_init (decl);
18480 if (decl && !DECL_P (decl))
18481 in_base_initializer = 1;
18483 init = TREE_VALUE (t);
18484 if (init != void_type_node)
18485 init = tsubst_expr (init, argvec,
18486 tf_warning_or_error, NULL_TREE,
18487 /*integral_constant_expression_p=*/false);
18488 in_base_initializer = 0;
18493 init = build_tree_list (decl, init);
18494 TREE_CHAIN (init) = inits;
18502 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
18505 set_current_access_from_decl (tree decl)
18507 if (TREE_PRIVATE (decl))
18508 current_access_specifier = access_private_node;
18509 else if (TREE_PROTECTED (decl))
18510 current_access_specifier = access_protected_node;
18512 current_access_specifier = access_public_node;
18515 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
18516 is the instantiation (which should have been created with
18517 start_enum) and ARGS are the template arguments to use. */
18520 tsubst_enum (tree tag, tree newtag, tree args)
18524 if (SCOPED_ENUM_P (newtag))
18525 begin_scope (sk_scoped_enum, newtag);
18527 for (e = TYPE_VALUES (tag); e; e = TREE_CHAIN (e))
18532 decl = TREE_VALUE (e);
18533 /* Note that in a template enum, the TREE_VALUE is the
18534 CONST_DECL, not the corresponding INTEGER_CST. */
18535 value = tsubst_expr (DECL_INITIAL (decl),
18536 args, tf_warning_or_error, NULL_TREE,
18537 /*integral_constant_expression_p=*/true);
18539 /* Give this enumeration constant the correct access. */
18540 set_current_access_from_decl (decl);
18542 /* Actually build the enumerator itself. */
18544 (DECL_NAME (decl), value, newtag, DECL_SOURCE_LOCATION (decl));
18547 if (SCOPED_ENUM_P (newtag))
18550 finish_enum_value_list (newtag);
18551 finish_enum (newtag);
18553 DECL_SOURCE_LOCATION (TYPE_NAME (newtag))
18554 = DECL_SOURCE_LOCATION (TYPE_NAME (tag));
18557 /* DECL is a FUNCTION_DECL that is a template specialization. Return
18558 its type -- but without substituting the innermost set of template
18559 arguments. So, innermost set of template parameters will appear in
18563 get_mostly_instantiated_function_type (tree decl)
18571 tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
18572 targs = DECL_TI_ARGS (decl);
18573 tparms = DECL_TEMPLATE_PARMS (tmpl);
18574 parm_depth = TMPL_PARMS_DEPTH (tparms);
18576 /* There should be as many levels of arguments as there are levels
18578 gcc_assert (parm_depth == TMPL_ARGS_DEPTH (targs));
18580 fn_type = TREE_TYPE (tmpl);
18582 if (parm_depth == 1)
18583 /* No substitution is necessary. */
18590 /* Replace the innermost level of the TARGS with NULL_TREEs to
18591 let tsubst know not to substitute for those parameters. */
18592 partial_args = make_tree_vec (TREE_VEC_LENGTH (targs));
18593 for (i = 1; i < TMPL_ARGS_DEPTH (targs); ++i)
18594 SET_TMPL_ARGS_LEVEL (partial_args, i,
18595 TMPL_ARGS_LEVEL (targs, i));
18596 SET_TMPL_ARGS_LEVEL (partial_args,
18597 TMPL_ARGS_DEPTH (targs),
18598 make_tree_vec (DECL_NTPARMS (tmpl)));
18600 /* Make sure that we can see identifiers, and compute access
18602 push_access_scope (decl);
18604 ++processing_template_decl;
18605 /* Now, do the (partial) substitution to figure out the
18606 appropriate function type. */
18607 fn_type = tsubst (fn_type, partial_args, tf_error, NULL_TREE);
18608 --processing_template_decl;
18610 /* Substitute into the template parameters to obtain the real
18611 innermost set of parameters. This step is important if the
18612 innermost set of template parameters contains value
18613 parameters whose types depend on outer template parameters. */
18614 TREE_VEC_LENGTH (partial_args)--;
18615 tparms = tsubst_template_parms (tparms, partial_args, tf_error);
18617 pop_access_scope (decl);
18623 /* Return truthvalue if we're processing a template different from
18624 the last one involved in diagnostics. */
18626 problematic_instantiation_changed (void)
18628 return current_tinst_level != last_error_tinst_level;
18631 /* Remember current template involved in diagnostics. */
18633 record_last_problematic_instantiation (void)
18635 last_error_tinst_level = current_tinst_level;
18638 struct tinst_level *
18639 current_instantiation (void)
18641 return current_tinst_level;
18644 /* [temp.param] Check that template non-type parm TYPE is of an allowable
18645 type. Return zero for ok, nonzero for disallowed. Issue error and
18646 warning messages under control of COMPLAIN. */
18649 invalid_nontype_parm_type_p (tree type, tsubst_flags_t complain)
18651 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
18653 else if (POINTER_TYPE_P (type))
18655 else if (TYPE_PTR_TO_MEMBER_P (type))
18657 else if (TREE_CODE (type) == TEMPLATE_TYPE_PARM)
18659 else if (TREE_CODE (type) == TYPENAME_TYPE)
18661 else if (TREE_CODE (type) == DECLTYPE_TYPE)
18664 if (complain & tf_error)
18665 error ("%q#T is not a valid type for a template constant parameter", type);
18669 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
18670 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
18673 dependent_type_p_r (tree type)
18679 A type is dependent if it is:
18681 -- a template parameter. Template template parameters are types
18682 for us (since TYPE_P holds true for them) so we handle
18684 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
18685 || TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM)
18687 /* -- a qualified-id with a nested-name-specifier which contains a
18688 class-name that names a dependent type or whose unqualified-id
18689 names a dependent type. */
18690 if (TREE_CODE (type) == TYPENAME_TYPE)
18692 /* -- a cv-qualified type where the cv-unqualified type is
18694 type = TYPE_MAIN_VARIANT (type);
18695 /* -- a compound type constructed from any dependent type. */
18696 if (TYPE_PTR_TO_MEMBER_P (type))
18697 return (dependent_type_p (TYPE_PTRMEM_CLASS_TYPE (type))
18698 || dependent_type_p (TYPE_PTRMEM_POINTED_TO_TYPE
18700 else if (TREE_CODE (type) == POINTER_TYPE
18701 || TREE_CODE (type) == REFERENCE_TYPE)
18702 return dependent_type_p (TREE_TYPE (type));
18703 else if (TREE_CODE (type) == FUNCTION_TYPE
18704 || TREE_CODE (type) == METHOD_TYPE)
18708 if (dependent_type_p (TREE_TYPE (type)))
18710 for (arg_type = TYPE_ARG_TYPES (type);
18712 arg_type = TREE_CHAIN (arg_type))
18713 if (dependent_type_p (TREE_VALUE (arg_type)))
18717 /* -- an array type constructed from any dependent type or whose
18718 size is specified by a constant expression that is
18721 We checked for type- and value-dependence of the bounds in
18722 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
18723 if (TREE_CODE (type) == ARRAY_TYPE)
18725 if (TYPE_DOMAIN (type)
18726 && dependent_type_p (TYPE_DOMAIN (type)))
18728 return dependent_type_p (TREE_TYPE (type));
18731 /* -- a template-id in which either the template name is a template
18733 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
18735 /* ... or any of the template arguments is a dependent type or
18736 an expression that is type-dependent or value-dependent. */
18737 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INFO (type)
18738 && (any_dependent_template_arguments_p
18739 (INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type)))))
18742 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
18743 dependent; if the argument of the `typeof' expression is not
18744 type-dependent, then it should already been have resolved. */
18745 if (TREE_CODE (type) == TYPEOF_TYPE
18746 || TREE_CODE (type) == DECLTYPE_TYPE
18747 || TREE_CODE (type) == UNDERLYING_TYPE)
18750 /* A template argument pack is dependent if any of its packed
18752 if (TREE_CODE (type) == TYPE_ARGUMENT_PACK)
18754 tree args = ARGUMENT_PACK_ARGS (type);
18755 int i, len = TREE_VEC_LENGTH (args);
18756 for (i = 0; i < len; ++i)
18757 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
18761 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
18762 be template parameters. */
18763 if (TREE_CODE (type) == TYPE_PACK_EXPANSION)
18766 /* The standard does not specifically mention types that are local
18767 to template functions or local classes, but they should be
18768 considered dependent too. For example:
18770 template <int I> void f() {
18775 The size of `E' cannot be known until the value of `I' has been
18776 determined. Therefore, `E' must be considered dependent. */
18777 scope = TYPE_CONTEXT (type);
18778 if (scope && TYPE_P (scope))
18779 return dependent_type_p (scope);
18780 /* Don't use type_dependent_expression_p here, as it can lead
18781 to infinite recursion trying to determine whether a lambda
18782 nested in a lambda is dependent (c++/47687). */
18783 else if (scope && TREE_CODE (scope) == FUNCTION_DECL
18784 && DECL_LANG_SPECIFIC (scope)
18785 && DECL_TEMPLATE_INFO (scope)
18786 && (any_dependent_template_arguments_p
18787 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (scope)))))
18790 /* Other types are non-dependent. */
18794 /* Returns TRUE if TYPE is dependent, in the sense of
18795 [temp.dep.type]. Note that a NULL type is considered dependent. */
18798 dependent_type_p (tree type)
18800 /* If there are no template parameters in scope, then there can't be
18801 any dependent types. */
18802 if (!processing_template_decl)
18804 /* If we are not processing a template, then nobody should be
18805 providing us with a dependent type. */
18807 gcc_assert (TREE_CODE (type) != TEMPLATE_TYPE_PARM || is_auto (type));
18811 /* If the type is NULL, we have not computed a type for the entity
18812 in question; in that case, the type is dependent. */
18816 /* Erroneous types can be considered non-dependent. */
18817 if (type == error_mark_node)
18820 /* If we have not already computed the appropriate value for TYPE,
18822 if (!TYPE_DEPENDENT_P_VALID (type))
18824 TYPE_DEPENDENT_P (type) = dependent_type_p_r (type);
18825 TYPE_DEPENDENT_P_VALID (type) = 1;
18828 return TYPE_DEPENDENT_P (type);
18831 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
18832 lookup. In other words, a dependent type that is not the current
18836 dependent_scope_p (tree scope)
18838 return (scope && TYPE_P (scope) && dependent_type_p (scope)
18839 && !currently_open_class (scope));
18842 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
18843 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
18846 /* Note that this predicate is not appropriate for general expressions;
18847 only constant expressions (that satisfy potential_constant_expression)
18848 can be tested for value dependence.
18850 We should really also have a predicate for "instantiation-dependent".
18852 fold_non_dependent_expr: fold if constant and not type-dependent and not value-dependent.
18853 (what about instantiation-dependent constant-expressions?)
18854 is_late_template_attribute: defer if instantiation-dependent.
18855 compute_array_index_type: proceed if constant and not t- or v-dependent
18856 if instantiation-dependent, need to remember full expression
18857 uses_template_parms: FIXME - need to audit callers
18858 tsubst_decl [function_decl]: Why is this using value_dependent_expression_p?
18859 dependent_type_p [array_type]: dependent if index type is dependent
18861 static_assert - instantiation-dependent */
18864 value_dependent_expression_p (tree expression)
18866 if (!processing_template_decl)
18869 /* A name declared with a dependent type. */
18870 if (DECL_P (expression) && type_dependent_expression_p (expression))
18873 switch (TREE_CODE (expression))
18875 case IDENTIFIER_NODE:
18876 /* A name that has not been looked up -- must be dependent. */
18879 case TEMPLATE_PARM_INDEX:
18880 /* A non-type template parm. */
18884 /* A non-type template parm. */
18885 if (DECL_TEMPLATE_PARM_P (expression))
18887 return value_dependent_expression_p (DECL_INITIAL (expression));
18890 /* A constant with literal type and is initialized
18891 with an expression that is value-dependent. */
18892 if (DECL_INITIAL (expression)
18893 && decl_constant_var_p (expression)
18894 && value_dependent_expression_p (DECL_INITIAL (expression)))
18898 case DYNAMIC_CAST_EXPR:
18899 case STATIC_CAST_EXPR:
18900 case CONST_CAST_EXPR:
18901 case REINTERPRET_CAST_EXPR:
18903 /* These expressions are value-dependent if the type to which
18904 the cast occurs is dependent or the expression being casted
18905 is value-dependent. */
18907 tree type = TREE_TYPE (expression);
18909 if (dependent_type_p (type))
18912 /* A functional cast has a list of operands. */
18913 expression = TREE_OPERAND (expression, 0);
18916 /* If there are no operands, it must be an expression such
18917 as "int()". This should not happen for aggregate types
18918 because it would form non-constant expressions. */
18919 gcc_assert (cxx_dialect >= cxx0x
18920 || INTEGRAL_OR_ENUMERATION_TYPE_P (type));
18925 if (TREE_CODE (expression) == TREE_LIST)
18926 return any_value_dependent_elements_p (expression);
18928 return value_dependent_expression_p (expression);
18934 /* A `sizeof' expression is value-dependent if the operand is
18935 type-dependent or is a pack expansion. */
18936 expression = TREE_OPERAND (expression, 0);
18937 if (PACK_EXPANSION_P (expression))
18939 else if (TYPE_P (expression))
18940 return dependent_type_p (expression);
18941 return type_dependent_expression_p (expression);
18943 case AT_ENCODE_EXPR:
18944 /* An 'encode' expression is value-dependent if the operand is
18946 expression = TREE_OPERAND (expression, 0);
18947 return dependent_type_p (expression);
18949 case NOEXCEPT_EXPR:
18950 expression = TREE_OPERAND (expression, 0);
18951 return type_dependent_expression_p (expression);
18955 tree name = TREE_OPERAND (expression, 1);
18956 return value_dependent_expression_p (name);
18959 case COMPONENT_REF:
18960 return (value_dependent_expression_p (TREE_OPERAND (expression, 0))
18961 || value_dependent_expression_p (TREE_OPERAND (expression, 1)));
18963 case NONTYPE_ARGUMENT_PACK:
18964 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
18965 is value-dependent. */
18967 tree values = ARGUMENT_PACK_ARGS (expression);
18968 int i, len = TREE_VEC_LENGTH (values);
18970 for (i = 0; i < len; ++i)
18971 if (value_dependent_expression_p (TREE_VEC_ELT (values, i)))
18979 tree type2 = TRAIT_EXPR_TYPE2 (expression);
18980 return (dependent_type_p (TRAIT_EXPR_TYPE1 (expression))
18981 || (type2 ? dependent_type_p (type2) : false));
18985 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
18986 || (value_dependent_expression_p (TREE_OPERAND (expression, 2))));
18989 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
18990 || (value_dependent_expression_p (TREE_OPERAND (expression, 1))));
18994 tree op = TREE_OPERAND (expression, 0);
18995 return (value_dependent_expression_p (op)
18996 || has_value_dependent_address (op));
19001 tree fn = get_callee_fndecl (expression);
19003 if (!fn && value_dependent_expression_p (CALL_EXPR_FN (expression)))
19005 nargs = call_expr_nargs (expression);
19006 for (i = 0; i < nargs; ++i)
19008 tree op = CALL_EXPR_ARG (expression, i);
19009 /* In a call to a constexpr member function, look through the
19010 implicit ADDR_EXPR on the object argument so that it doesn't
19011 cause the call to be considered value-dependent. We also
19012 look through it in potential_constant_expression. */
19013 if (i == 0 && fn && DECL_DECLARED_CONSTEXPR_P (fn)
19014 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
19015 && TREE_CODE (op) == ADDR_EXPR)
19016 op = TREE_OPERAND (op, 0);
19017 if (value_dependent_expression_p (op))
19023 case TEMPLATE_ID_EXPR:
19024 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
19026 return type_dependent_expression_p (expression);
19032 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), ix, val)
19033 if (value_dependent_expression_p (val))
19039 /* A constant expression is value-dependent if any subexpression is
19040 value-dependent. */
19041 switch (TREE_CODE_CLASS (TREE_CODE (expression)))
19043 case tcc_reference:
19045 case tcc_comparison:
19047 case tcc_expression:
19050 int i, len = cp_tree_operand_length (expression);
19052 for (i = 0; i < len; i++)
19054 tree t = TREE_OPERAND (expression, i);
19056 /* In some cases, some of the operands may be missing.l
19057 (For example, in the case of PREDECREMENT_EXPR, the
19058 amount to increment by may be missing.) That doesn't
19059 make the expression dependent. */
19060 if (t && value_dependent_expression_p (t))
19071 /* The expression is not value-dependent. */
19075 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
19076 [temp.dep.expr]. Note that an expression with no type is
19077 considered dependent. Other parts of the compiler arrange for an
19078 expression with type-dependent subexpressions to have no type, so
19079 this function doesn't have to be fully recursive. */
19082 type_dependent_expression_p (tree expression)
19084 if (!processing_template_decl)
19087 if (expression == error_mark_node)
19090 /* An unresolved name is always dependent. */
19091 if (TREE_CODE (expression) == IDENTIFIER_NODE
19092 || TREE_CODE (expression) == USING_DECL)
19095 /* Some expression forms are never type-dependent. */
19096 if (TREE_CODE (expression) == PSEUDO_DTOR_EXPR
19097 || TREE_CODE (expression) == SIZEOF_EXPR
19098 || TREE_CODE (expression) == ALIGNOF_EXPR
19099 || TREE_CODE (expression) == AT_ENCODE_EXPR
19100 || TREE_CODE (expression) == NOEXCEPT_EXPR
19101 || TREE_CODE (expression) == TRAIT_EXPR
19102 || TREE_CODE (expression) == TYPEID_EXPR
19103 || TREE_CODE (expression) == DELETE_EXPR
19104 || TREE_CODE (expression) == VEC_DELETE_EXPR
19105 || TREE_CODE (expression) == THROW_EXPR)
19108 /* The types of these expressions depends only on the type to which
19109 the cast occurs. */
19110 if (TREE_CODE (expression) == DYNAMIC_CAST_EXPR
19111 || TREE_CODE (expression) == STATIC_CAST_EXPR
19112 || TREE_CODE (expression) == CONST_CAST_EXPR
19113 || TREE_CODE (expression) == REINTERPRET_CAST_EXPR
19114 || TREE_CODE (expression) == CAST_EXPR)
19115 return dependent_type_p (TREE_TYPE (expression));
19117 /* The types of these expressions depends only on the type created
19118 by the expression. */
19119 if (TREE_CODE (expression) == NEW_EXPR
19120 || TREE_CODE (expression) == VEC_NEW_EXPR)
19122 /* For NEW_EXPR tree nodes created inside a template, either
19123 the object type itself or a TREE_LIST may appear as the
19125 tree type = TREE_OPERAND (expression, 1);
19126 if (TREE_CODE (type) == TREE_LIST)
19127 /* This is an array type. We need to check array dimensions
19129 return dependent_type_p (TREE_VALUE (TREE_PURPOSE (type)))
19130 || value_dependent_expression_p
19131 (TREE_OPERAND (TREE_VALUE (type), 1));
19133 return dependent_type_p (type);
19136 if (TREE_CODE (expression) == SCOPE_REF)
19138 tree scope = TREE_OPERAND (expression, 0);
19139 tree name = TREE_OPERAND (expression, 1);
19141 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
19142 contains an identifier associated by name lookup with one or more
19143 declarations declared with a dependent type, or...a
19144 nested-name-specifier or qualified-id that names a member of an
19145 unknown specialization. */
19146 return (type_dependent_expression_p (name)
19147 || dependent_scope_p (scope));
19150 if (TREE_CODE (expression) == FUNCTION_DECL
19151 && DECL_LANG_SPECIFIC (expression)
19152 && DECL_TEMPLATE_INFO (expression)
19153 && (any_dependent_template_arguments_p
19154 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (expression)))))
19157 if (TREE_CODE (expression) == TEMPLATE_DECL
19158 && !DECL_TEMPLATE_TEMPLATE_PARM_P (expression))
19161 if (TREE_CODE (expression) == STMT_EXPR)
19162 expression = stmt_expr_value_expr (expression);
19164 if (BRACE_ENCLOSED_INITIALIZER_P (expression))
19169 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), i, elt)
19171 if (type_dependent_expression_p (elt))
19177 /* A static data member of the current instantiation with incomplete
19178 array type is type-dependent, as the definition and specializations
19179 can have different bounds. */
19180 if (TREE_CODE (expression) == VAR_DECL
19181 && DECL_CLASS_SCOPE_P (expression)
19182 && dependent_type_p (DECL_CONTEXT (expression))
19183 && VAR_HAD_UNKNOWN_BOUND (expression))
19186 if (TREE_TYPE (expression) == unknown_type_node)
19188 if (TREE_CODE (expression) == ADDR_EXPR)
19189 return type_dependent_expression_p (TREE_OPERAND (expression, 0));
19190 if (TREE_CODE (expression) == COMPONENT_REF
19191 || TREE_CODE (expression) == OFFSET_REF)
19193 if (type_dependent_expression_p (TREE_OPERAND (expression, 0)))
19195 expression = TREE_OPERAND (expression, 1);
19196 if (TREE_CODE (expression) == IDENTIFIER_NODE)
19199 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
19200 if (TREE_CODE (expression) == SCOPE_REF)
19203 if (TREE_CODE (expression) == BASELINK)
19204 expression = BASELINK_FUNCTIONS (expression);
19206 if (TREE_CODE (expression) == TEMPLATE_ID_EXPR)
19208 if (any_dependent_template_arguments_p
19209 (TREE_OPERAND (expression, 1)))
19211 expression = TREE_OPERAND (expression, 0);
19213 gcc_assert (TREE_CODE (expression) == OVERLOAD
19214 || TREE_CODE (expression) == FUNCTION_DECL);
19218 if (type_dependent_expression_p (OVL_CURRENT (expression)))
19220 expression = OVL_NEXT (expression);
19225 gcc_assert (TREE_CODE (expression) != TYPE_DECL);
19227 return (dependent_type_p (TREE_TYPE (expression)));
19230 /* Like type_dependent_expression_p, but it also works while not processing
19231 a template definition, i.e. during substitution or mangling. */
19234 type_dependent_expression_p_push (tree expr)
19237 ++processing_template_decl;
19238 b = type_dependent_expression_p (expr);
19239 --processing_template_decl;
19243 /* Returns TRUE if ARGS contains a type-dependent expression. */
19246 any_type_dependent_arguments_p (const VEC(tree,gc) *args)
19251 FOR_EACH_VEC_ELT (tree, args, i, arg)
19253 if (type_dependent_expression_p (arg))
19259 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
19260 expressions) contains any type-dependent expressions. */
19263 any_type_dependent_elements_p (const_tree list)
19265 for (; list; list = TREE_CHAIN (list))
19266 if (value_dependent_expression_p (TREE_VALUE (list)))
19272 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
19273 expressions) contains any value-dependent expressions. */
19276 any_value_dependent_elements_p (const_tree list)
19278 for (; list; list = TREE_CHAIN (list))
19279 if (value_dependent_expression_p (TREE_VALUE (list)))
19285 /* Returns TRUE if the ARG (a template argument) is dependent. */
19288 dependent_template_arg_p (tree arg)
19290 if (!processing_template_decl)
19293 /* Assume a template argument that was wrongly written by the user
19294 is dependent. This is consistent with what
19295 any_dependent_template_arguments_p [that calls this function]
19297 if (!arg || arg == error_mark_node)
19300 if (TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
19301 arg = ARGUMENT_PACK_SELECT_ARG (arg);
19303 if (TREE_CODE (arg) == TEMPLATE_DECL
19304 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
19305 return dependent_template_p (arg);
19306 else if (ARGUMENT_PACK_P (arg))
19308 tree args = ARGUMENT_PACK_ARGS (arg);
19309 int i, len = TREE_VEC_LENGTH (args);
19310 for (i = 0; i < len; ++i)
19312 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
19318 else if (TYPE_P (arg))
19319 return dependent_type_p (arg);
19321 return (type_dependent_expression_p (arg)
19322 || value_dependent_expression_p (arg));
19325 /* Returns true if ARGS (a collection of template arguments) contains
19326 any types that require structural equality testing. */
19329 any_template_arguments_need_structural_equality_p (tree args)
19336 if (args == error_mark_node)
19339 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
19341 tree level = TMPL_ARGS_LEVEL (args, i + 1);
19342 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
19344 tree arg = TREE_VEC_ELT (level, j);
19345 tree packed_args = NULL_TREE;
19348 if (ARGUMENT_PACK_P (arg))
19350 /* Look inside the argument pack. */
19351 packed_args = ARGUMENT_PACK_ARGS (arg);
19352 len = TREE_VEC_LENGTH (packed_args);
19355 for (k = 0; k < len; ++k)
19358 arg = TREE_VEC_ELT (packed_args, k);
19360 if (error_operand_p (arg))
19362 else if (TREE_CODE (arg) == TEMPLATE_DECL
19363 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
19365 else if (TYPE_P (arg) && TYPE_STRUCTURAL_EQUALITY_P (arg))
19367 else if (!TYPE_P (arg) && TREE_TYPE (arg)
19368 && TYPE_STRUCTURAL_EQUALITY_P (TREE_TYPE (arg)))
19377 /* Returns true if ARGS (a collection of template arguments) contains
19378 any dependent arguments. */
19381 any_dependent_template_arguments_p (const_tree args)
19388 if (args == error_mark_node)
19391 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
19393 const_tree level = TMPL_ARGS_LEVEL (args, i + 1);
19394 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
19395 if (dependent_template_arg_p (TREE_VEC_ELT (level, j)))
19402 /* Returns TRUE if the template TMPL is dependent. */
19405 dependent_template_p (tree tmpl)
19407 if (TREE_CODE (tmpl) == OVERLOAD)
19411 if (dependent_template_p (OVL_CURRENT (tmpl)))
19413 tmpl = OVL_NEXT (tmpl);
19418 /* Template template parameters are dependent. */
19419 if (DECL_TEMPLATE_TEMPLATE_PARM_P (tmpl)
19420 || TREE_CODE (tmpl) == TEMPLATE_TEMPLATE_PARM)
19422 /* So are names that have not been looked up. */
19423 if (TREE_CODE (tmpl) == SCOPE_REF
19424 || TREE_CODE (tmpl) == IDENTIFIER_NODE)
19426 /* So are member templates of dependent classes. */
19427 if (TYPE_P (CP_DECL_CONTEXT (tmpl)))
19428 return dependent_type_p (DECL_CONTEXT (tmpl));
19432 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
19435 dependent_template_id_p (tree tmpl, tree args)
19437 return (dependent_template_p (tmpl)
19438 || any_dependent_template_arguments_p (args));
19441 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
19445 dependent_omp_for_p (tree declv, tree initv, tree condv, tree incrv)
19449 if (!processing_template_decl)
19452 for (i = 0; i < TREE_VEC_LENGTH (declv); i++)
19454 tree decl = TREE_VEC_ELT (declv, i);
19455 tree init = TREE_VEC_ELT (initv, i);
19456 tree cond = TREE_VEC_ELT (condv, i);
19457 tree incr = TREE_VEC_ELT (incrv, i);
19459 if (type_dependent_expression_p (decl))
19462 if (init && type_dependent_expression_p (init))
19465 if (type_dependent_expression_p (cond))
19468 if (COMPARISON_CLASS_P (cond)
19469 && (type_dependent_expression_p (TREE_OPERAND (cond, 0))
19470 || type_dependent_expression_p (TREE_OPERAND (cond, 1))))
19473 if (TREE_CODE (incr) == MODOP_EXPR)
19475 if (type_dependent_expression_p (TREE_OPERAND (incr, 0))
19476 || type_dependent_expression_p (TREE_OPERAND (incr, 2)))
19479 else if (type_dependent_expression_p (incr))
19481 else if (TREE_CODE (incr) == MODIFY_EXPR)
19483 if (type_dependent_expression_p (TREE_OPERAND (incr, 0)))
19485 else if (BINARY_CLASS_P (TREE_OPERAND (incr, 1)))
19487 tree t = TREE_OPERAND (incr, 1);
19488 if (type_dependent_expression_p (TREE_OPERAND (t, 0))
19489 || type_dependent_expression_p (TREE_OPERAND (t, 1)))
19498 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
19499 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
19500 no such TYPE can be found. Note that this function peers inside
19501 uninstantiated templates and therefore should be used only in
19502 extremely limited situations. ONLY_CURRENT_P restricts this
19503 peering to the currently open classes hierarchy (which is required
19504 when comparing types). */
19507 resolve_typename_type (tree type, bool only_current_p)
19516 gcc_assert (TREE_CODE (type) == TYPENAME_TYPE);
19518 scope = TYPE_CONTEXT (type);
19519 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
19520 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
19521 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
19522 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
19523 identifier of the TYPENAME_TYPE anymore.
19524 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
19525 TYPENAME_TYPE instead, we avoid messing up with a possible
19526 typedef variant case. */
19527 name = TYPE_IDENTIFIER (TYPE_MAIN_VARIANT (type));
19529 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
19530 it first before we can figure out what NAME refers to. */
19531 if (TREE_CODE (scope) == TYPENAME_TYPE)
19532 scope = resolve_typename_type (scope, only_current_p);
19533 /* If we don't know what SCOPE refers to, then we cannot resolve the
19535 if (TREE_CODE (scope) == TYPENAME_TYPE)
19537 /* If the SCOPE is a template type parameter, we have no way of
19538 resolving the name. */
19539 if (TREE_CODE (scope) == TEMPLATE_TYPE_PARM)
19541 /* If the SCOPE is not the current instantiation, there's no reason
19542 to look inside it. */
19543 if (only_current_p && !currently_open_class (scope))
19545 /* If this is a typedef, we don't want to look inside (c++/11987). */
19546 if (typedef_variant_p (type))
19548 /* If SCOPE isn't the template itself, it will not have a valid
19549 TYPE_FIELDS list. */
19550 if (same_type_p (scope, CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope)))
19551 /* scope is either the template itself or a compatible instantiation
19552 like X<T>, so look up the name in the original template. */
19553 scope = CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope);
19555 /* scope is a partial instantiation, so we can't do the lookup or we
19556 will lose the template arguments. */
19558 /* Enter the SCOPE so that name lookup will be resolved as if we
19559 were in the class definition. In particular, SCOPE will no
19560 longer be considered a dependent type. */
19561 pushed_scope = push_scope (scope);
19562 /* Look up the declaration. */
19563 decl = lookup_member (scope, name, /*protect=*/0, /*want_type=*/true);
19565 result = NULL_TREE;
19567 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
19568 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
19571 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == IDENTIFIER_NODE
19572 && TREE_CODE (decl) == TYPE_DECL)
19574 result = TREE_TYPE (decl);
19575 if (result == error_mark_node)
19576 result = NULL_TREE;
19578 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == TEMPLATE_ID_EXPR
19579 && DECL_CLASS_TEMPLATE_P (decl))
19583 /* Obtain the template and the arguments. */
19584 tmpl = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 0);
19585 args = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 1);
19586 /* Instantiate the template. */
19587 result = lookup_template_class (tmpl, args, NULL_TREE, NULL_TREE,
19588 /*entering_scope=*/0,
19589 tf_error | tf_user);
19590 if (result == error_mark_node)
19591 result = NULL_TREE;
19594 /* Leave the SCOPE. */
19596 pop_scope (pushed_scope);
19598 /* If we failed to resolve it, return the original typename. */
19602 /* If lookup found a typename type, resolve that too. */
19603 if (TREE_CODE (result) == TYPENAME_TYPE && !TYPENAME_IS_RESOLVING_P (result))
19605 /* Ill-formed programs can cause infinite recursion here, so we
19606 must catch that. */
19607 TYPENAME_IS_RESOLVING_P (type) = 1;
19608 result = resolve_typename_type (result, only_current_p);
19609 TYPENAME_IS_RESOLVING_P (type) = 0;
19612 /* Qualify the resulting type. */
19613 quals = cp_type_quals (type);
19615 result = cp_build_qualified_type (result, cp_type_quals (result) | quals);
19620 /* EXPR is an expression which is not type-dependent. Return a proxy
19621 for EXPR that can be used to compute the types of larger
19622 expressions containing EXPR. */
19625 build_non_dependent_expr (tree expr)
19629 #ifdef ENABLE_CHECKING
19630 /* Try to get a constant value for all non-type-dependent expressions in
19631 order to expose bugs in *_dependent_expression_p and constexpr. */
19632 if (cxx_dialect >= cxx0x)
19633 maybe_constant_value (fold_non_dependent_expr_sfinae (expr, tf_none));
19636 /* Preserve OVERLOADs; the functions must be available to resolve
19639 if (TREE_CODE (inner_expr) == STMT_EXPR)
19640 inner_expr = stmt_expr_value_expr (inner_expr);
19641 if (TREE_CODE (inner_expr) == ADDR_EXPR)
19642 inner_expr = TREE_OPERAND (inner_expr, 0);
19643 if (TREE_CODE (inner_expr) == COMPONENT_REF)
19644 inner_expr = TREE_OPERAND (inner_expr, 1);
19645 if (is_overloaded_fn (inner_expr)
19646 || TREE_CODE (inner_expr) == OFFSET_REF)
19648 /* There is no need to return a proxy for a variable. */
19649 if (TREE_CODE (expr) == VAR_DECL)
19651 /* Preserve string constants; conversions from string constants to
19652 "char *" are allowed, even though normally a "const char *"
19653 cannot be used to initialize a "char *". */
19654 if (TREE_CODE (expr) == STRING_CST)
19656 /* Preserve arithmetic constants, as an optimization -- there is no
19657 reason to create a new node. */
19658 if (TREE_CODE (expr) == INTEGER_CST || TREE_CODE (expr) == REAL_CST)
19660 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
19661 There is at least one place where we want to know that a
19662 particular expression is a throw-expression: when checking a ?:
19663 expression, there are special rules if the second or third
19664 argument is a throw-expression. */
19665 if (TREE_CODE (expr) == THROW_EXPR)
19668 if (TREE_CODE (expr) == COND_EXPR)
19669 return build3 (COND_EXPR,
19671 TREE_OPERAND (expr, 0),
19672 (TREE_OPERAND (expr, 1)
19673 ? build_non_dependent_expr (TREE_OPERAND (expr, 1))
19674 : build_non_dependent_expr (TREE_OPERAND (expr, 0))),
19675 build_non_dependent_expr (TREE_OPERAND (expr, 2)));
19676 if (TREE_CODE (expr) == COMPOUND_EXPR
19677 && !COMPOUND_EXPR_OVERLOADED (expr))
19678 return build2 (COMPOUND_EXPR,
19680 TREE_OPERAND (expr, 0),
19681 build_non_dependent_expr (TREE_OPERAND (expr, 1)));
19683 /* If the type is unknown, it can't really be non-dependent */
19684 gcc_assert (TREE_TYPE (expr) != unknown_type_node);
19686 /* Otherwise, build a NON_DEPENDENT_EXPR. */
19687 return build1 (NON_DEPENDENT_EXPR, TREE_TYPE (expr), expr);
19690 /* ARGS is a vector of expressions as arguments to a function call.
19691 Replace the arguments with equivalent non-dependent expressions.
19692 This modifies ARGS in place. */
19695 make_args_non_dependent (VEC(tree,gc) *args)
19700 FOR_EACH_VEC_ELT (tree, args, ix, arg)
19702 tree newarg = build_non_dependent_expr (arg);
19704 VEC_replace (tree, args, ix, newarg);
19708 /* Returns a type which represents 'auto'. We use a TEMPLATE_TYPE_PARM
19709 with a level one deeper than the actual template parms. */
19714 tree au = cxx_make_type (TEMPLATE_TYPE_PARM);
19715 TYPE_NAME (au) = build_decl (BUILTINS_LOCATION,
19716 TYPE_DECL, get_identifier ("auto"), au);
19717 TYPE_STUB_DECL (au) = TYPE_NAME (au);
19718 TEMPLATE_TYPE_PARM_INDEX (au) = build_template_parm_index
19719 (0, processing_template_decl + 1, processing_template_decl + 1,
19720 0, TYPE_NAME (au), NULL_TREE);
19721 TYPE_CANONICAL (au) = canonical_type_parameter (au);
19722 DECL_ARTIFICIAL (TYPE_NAME (au)) = 1;
19723 SET_DECL_TEMPLATE_PARM_P (TYPE_NAME (au));
19728 /* Given type ARG, return std::initializer_list<ARG>. */
19733 tree std_init_list = namespace_binding
19734 (get_identifier ("initializer_list"), std_node);
19736 if (!std_init_list || !DECL_CLASS_TEMPLATE_P (std_init_list))
19738 error ("deducing from brace-enclosed initializer list requires "
19739 "#include <initializer_list>");
19740 return error_mark_node;
19742 argvec = make_tree_vec (1);
19743 TREE_VEC_ELT (argvec, 0) = arg;
19744 return lookup_template_class (std_init_list, argvec, NULL_TREE,
19745 NULL_TREE, 0, tf_warning_or_error);
19748 /* Replace auto in TYPE with std::initializer_list<auto>. */
19751 listify_autos (tree type, tree auto_node)
19753 tree init_auto = listify (auto_node);
19754 tree argvec = make_tree_vec (1);
19755 TREE_VEC_ELT (argvec, 0) = init_auto;
19756 if (processing_template_decl)
19757 argvec = add_to_template_args (current_template_args (), argvec);
19758 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
19761 /* walk_tree helper for do_auto_deduction. */
19764 contains_auto_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
19767 /* Is this a variable with the type we're looking for? */
19769 && TREE_TYPE (*tp) == type)
19775 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
19776 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
19779 do_auto_deduction (tree type, tree init, tree auto_node)
19781 tree parms, tparms, targs;
19786 if (processing_template_decl
19787 && (TREE_TYPE (init) == NULL_TREE
19788 || BRACE_ENCLOSED_INITIALIZER_P (init)))
19789 /* Not enough information to try this yet. */
19792 /* The name of the object being declared shall not appear in the
19793 initializer expression. */
19794 decl = cp_walk_tree_without_duplicates (&init, contains_auto_r, type);
19797 error ("variable %q#D with %<auto%> type used in its own "
19798 "initializer", decl);
19799 return error_mark_node;
19802 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
19803 with either a new invented type template parameter U or, if the
19804 initializer is a braced-init-list (8.5.4), with
19805 std::initializer_list<U>. */
19806 if (BRACE_ENCLOSED_INITIALIZER_P (init))
19807 type = listify_autos (type, auto_node);
19809 init = resolve_nondeduced_context (init);
19811 parms = build_tree_list (NULL_TREE, type);
19813 tparms = make_tree_vec (1);
19814 targs = make_tree_vec (1);
19815 TREE_VEC_ELT (tparms, 0)
19816 = build_tree_list (NULL_TREE, TYPE_NAME (auto_node));
19817 val = type_unification_real (tparms, targs, parms, args, 1, 0,
19818 DEDUCE_CALL, LOOKUP_NORMAL,
19819 /*explain_p=*/false);
19822 if (processing_template_decl)
19823 /* Try again at instantiation time. */
19825 if (type && type != error_mark_node)
19826 /* If type is error_mark_node a diagnostic must have been
19827 emitted by now. Also, having a mention to '<type error>'
19828 in the diagnostic is not really useful to the user. */
19829 error ("unable to deduce %qT from %qE", type, init);
19830 return error_mark_node;
19833 /* If the list of declarators contains more than one declarator, the type
19834 of each declared variable is determined as described above. If the
19835 type deduced for the template parameter U is not the same in each
19836 deduction, the program is ill-formed. */
19837 if (TREE_TYPE (auto_node)
19838 && !same_type_p (TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0)))
19840 error ("inconsistent deduction for %qT: %qT and then %qT",
19841 auto_node, TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0));
19842 return error_mark_node;
19844 TREE_TYPE (auto_node) = TREE_VEC_ELT (targs, 0);
19846 if (processing_template_decl)
19847 targs = add_to_template_args (current_template_args (), targs);
19848 return tsubst (type, targs, tf_warning_or_error, NULL_TREE);
19851 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
19855 splice_late_return_type (tree type, tree late_return_type)
19859 if (late_return_type == NULL_TREE)
19861 argvec = make_tree_vec (1);
19862 TREE_VEC_ELT (argvec, 0) = late_return_type;
19863 if (processing_template_parmlist)
19864 /* For a late-specified return type in a template type-parameter, we
19865 need to add a dummy argument level for its parmlist. */
19866 argvec = add_to_template_args
19867 (make_tree_vec (processing_template_parmlist), argvec);
19868 if (current_template_parms)
19869 argvec = add_to_template_args (current_template_args (), argvec);
19870 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
19873 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto'. */
19876 is_auto (const_tree type)
19878 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
19879 && TYPE_IDENTIFIER (type) == get_identifier ("auto"))
19885 /* Returns true iff TYPE contains a use of 'auto'. Since auto can only
19886 appear as a type-specifier for the declaration in question, we don't
19887 have to look through the whole type. */
19890 type_uses_auto (tree type)
19892 enum tree_code code;
19893 if (is_auto (type))
19896 code = TREE_CODE (type);
19898 if (code == POINTER_TYPE || code == REFERENCE_TYPE
19899 || code == OFFSET_TYPE || code == FUNCTION_TYPE
19900 || code == METHOD_TYPE || code == ARRAY_TYPE)
19901 return type_uses_auto (TREE_TYPE (type));
19903 if (TYPE_PTRMEMFUNC_P (type))
19904 return type_uses_auto (TREE_TYPE (TREE_TYPE
19905 (TYPE_PTRMEMFUNC_FN_TYPE (type))));
19910 /* For a given template T, return the vector of typedefs referenced
19911 in T for which access check is needed at T instantiation time.
19912 T is either a FUNCTION_DECL or a RECORD_TYPE.
19913 Those typedefs were added to T by the function
19914 append_type_to_template_for_access_check. */
19916 VEC(qualified_typedef_usage_t,gc)*
19917 get_types_needing_access_check (tree t)
19920 VEC(qualified_typedef_usage_t,gc) *result = NULL;
19922 if (!t || t == error_mark_node)
19925 if (!(ti = get_template_info (t)))
19928 if (CLASS_TYPE_P (t)
19929 || TREE_CODE (t) == FUNCTION_DECL)
19931 if (!TI_TEMPLATE (ti))
19934 result = TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti);
19940 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
19941 tied to T. That list of typedefs will be access checked at
19942 T instantiation time.
19943 T is either a FUNCTION_DECL or a RECORD_TYPE.
19944 TYPE_DECL is a TYPE_DECL node representing a typedef.
19945 SCOPE is the scope through which TYPE_DECL is accessed.
19946 LOCATION is the location of the usage point of TYPE_DECL.
19948 This function is a subroutine of
19949 append_type_to_template_for_access_check. */
19952 append_type_to_template_for_access_check_1 (tree t,
19955 location_t location)
19957 qualified_typedef_usage_t typedef_usage;
19960 if (!t || t == error_mark_node)
19963 gcc_assert ((TREE_CODE (t) == FUNCTION_DECL
19964 || CLASS_TYPE_P (t))
19966 && TREE_CODE (type_decl) == TYPE_DECL
19969 if (!(ti = get_template_info (t)))
19972 gcc_assert (TI_TEMPLATE (ti));
19974 typedef_usage.typedef_decl = type_decl;
19975 typedef_usage.context = scope;
19976 typedef_usage.locus = location;
19978 VEC_safe_push (qualified_typedef_usage_t, gc,
19979 TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti),
19983 /* Append TYPE_DECL to the template TEMPL.
19984 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
19985 At TEMPL instanciation time, TYPE_DECL will be checked to see
19986 if it can be accessed through SCOPE.
19987 LOCATION is the location of the usage point of TYPE_DECL.
19989 e.g. consider the following code snippet:
19996 template<class U> struct S
19998 C::myint mi; // <-- usage point of the typedef C::myint
20003 At S<char> instantiation time, we need to check the access of C::myint
20004 In other words, we need to check the access of the myint typedef through
20005 the C scope. For that purpose, this function will add the myint typedef
20006 and the scope C through which its being accessed to a list of typedefs
20007 tied to the template S. That list will be walked at template instantiation
20008 time and access check performed on each typedefs it contains.
20009 Note that this particular code snippet should yield an error because
20010 myint is private to C. */
20013 append_type_to_template_for_access_check (tree templ,
20016 location_t location)
20018 qualified_typedef_usage_t *iter;
20021 gcc_assert (type_decl && (TREE_CODE (type_decl) == TYPE_DECL));
20023 /* Make sure we don't append the type to the template twice. */
20024 FOR_EACH_VEC_ELT (qualified_typedef_usage_t,
20025 get_types_needing_access_check (templ),
20027 if (iter->typedef_decl == type_decl && scope == iter->context)
20030 append_type_to_template_for_access_check_1 (templ, type_decl,
20034 /* Set up the hash tables for template instantiations. */
20037 init_template_processing (void)
20039 decl_specializations = htab_create_ggc (37,
20040 hash_specialization,
20041 eq_specializations,
20043 type_specializations = htab_create_ggc (37,
20044 hash_specialization,
20045 eq_specializations,
20049 /* Print stats about the template hash tables for -fstats. */
20052 print_template_statistics (void)
20054 fprintf (stderr, "decl_specializations: size %ld, %ld elements, "
20055 "%f collisions\n", (long) htab_size (decl_specializations),
20056 (long) htab_elements (decl_specializations),
20057 htab_collisions (decl_specializations));
20058 fprintf (stderr, "type_specializations: size %ld, %ld elements, "
20059 "%f collisions\n", (long) htab_size (type_specializations),
20060 (long) htab_elements (type_specializations),
20061 htab_collisions (type_specializations));
20064 #include "gt-cp-pt.h"