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, 2012
4 Free Software Foundation, Inc.
5 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
6 Rewritten by Jason Merrill (jason@cygnus.com).
8 This file is part of GCC.
10 GCC is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3, or (at your option)
15 GCC is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with GCC; see the file COPYING3. If not see
22 <http://www.gnu.org/licenses/>. */
24 /* Known bugs or deficiencies include:
26 all methods must be provided in header files; can't use a source
27 file that contains only the method templates and "just win". */
31 #include "coretypes.h"
35 #include "pointer-set.h"
38 #include "c-family/c-common.h"
39 #include "c-family/c-objc.h"
40 #include "cp-objcp-common.h"
41 #include "tree-inline.h"
46 #include "tree-iterator.h"
49 /* The type of functions taking a tree, and some additional data, and
51 typedef int (*tree_fn_t) (tree, void*);
53 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
54 instantiations have been deferred, either because their definitions
55 were not yet available, or because we were putting off doing the work. */
56 struct GTY ((chain_next ("%h.next"))) pending_template {
57 struct pending_template *next;
58 struct tinst_level *tinst;
61 static GTY(()) struct pending_template *pending_templates;
62 static GTY(()) struct pending_template *last_pending_template;
64 int processing_template_parmlist;
65 static int template_header_count;
67 static GTY(()) tree saved_trees;
68 static VEC(int,heap) *inline_parm_levels;
70 static GTY(()) struct tinst_level *current_tinst_level;
72 static GTY(()) tree saved_access_scope;
74 /* Live only within one (recursive) call to tsubst_expr. We use
75 this to pass the statement expression node from the STMT_EXPR
76 to the EXPR_STMT that is its result. */
77 static tree cur_stmt_expr;
79 /* A map from local variable declarations in the body of the template
80 presently being instantiated to the corresponding instantiated
82 static htab_t local_specializations;
84 typedef struct GTY(()) spec_entry
91 static GTY ((param_is (spec_entry)))
92 htab_t decl_specializations;
94 static GTY ((param_is (spec_entry)))
95 htab_t type_specializations;
97 /* Contains canonical template parameter types. The vector is indexed by
98 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
99 TREE_LIST, whose TREE_VALUEs contain the canonical template
100 parameters of various types and levels. */
101 static GTY(()) VEC(tree,gc) *canonical_template_parms;
103 #define UNIFY_ALLOW_NONE 0
104 #define UNIFY_ALLOW_MORE_CV_QUAL 1
105 #define UNIFY_ALLOW_LESS_CV_QUAL 2
106 #define UNIFY_ALLOW_DERIVED 4
107 #define UNIFY_ALLOW_INTEGER 8
108 #define UNIFY_ALLOW_OUTER_LEVEL 16
109 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
110 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
112 enum template_base_result {
114 tbr_ambiguous_baseclass,
118 static void push_access_scope (tree);
119 static void pop_access_scope (tree);
120 static void push_deduction_access_scope (tree);
121 static void pop_deduction_access_scope (tree);
122 static bool resolve_overloaded_unification (tree, tree, tree, tree,
123 unification_kind_t, int,
125 static int try_one_overload (tree, tree, tree, tree, tree,
126 unification_kind_t, int, bool, bool);
127 static int unify (tree, tree, tree, tree, int, bool);
128 static void add_pending_template (tree);
129 static tree reopen_tinst_level (struct tinst_level *);
130 static tree tsubst_initializer_list (tree, tree);
131 static tree get_class_bindings (tree, tree, tree);
132 static tree coerce_template_parms (tree, tree, tree, tsubst_flags_t,
134 static void tsubst_enum (tree, tree, tree);
135 static tree add_to_template_args (tree, tree);
136 static tree add_outermost_template_args (tree, tree);
137 static bool check_instantiated_args (tree, tree, tsubst_flags_t);
138 static int maybe_adjust_types_for_deduction (unification_kind_t, tree*, tree*,
140 static int type_unification_real (tree, tree, tree, const tree *,
141 unsigned int, int, unification_kind_t, int,
143 static void note_template_header (int);
144 static tree convert_nontype_argument_function (tree, tree);
145 static tree convert_nontype_argument (tree, tree, tsubst_flags_t);
146 static tree convert_template_argument (tree, tree, tree,
147 tsubst_flags_t, int, tree);
148 static int for_each_template_parm (tree, tree_fn_t, void*,
149 struct pointer_set_t*, bool);
150 static tree expand_template_argument_pack (tree);
151 static tree build_template_parm_index (int, int, int, int, tree, tree);
152 static bool inline_needs_template_parms (tree);
153 static void push_inline_template_parms_recursive (tree, int);
154 static tree retrieve_local_specialization (tree);
155 static void register_local_specialization (tree, tree);
156 static hashval_t hash_specialization (const void *p);
157 static tree reduce_template_parm_level (tree, tree, int, tree, tsubst_flags_t);
158 static int mark_template_parm (tree, void *);
159 static int template_parm_this_level_p (tree, void *);
160 static tree tsubst_friend_function (tree, tree);
161 static tree tsubst_friend_class (tree, tree);
162 static int can_complete_type_without_circularity (tree);
163 static tree get_bindings (tree, tree, tree, bool);
164 static int template_decl_level (tree);
165 static int check_cv_quals_for_unify (int, tree, tree);
166 static void template_parm_level_and_index (tree, int*, int*);
167 static int unify_pack_expansion (tree, tree, tree,
168 tree, unification_kind_t, bool, bool);
169 static tree tsubst_template_arg (tree, tree, tsubst_flags_t, tree);
170 static tree tsubst_template_args (tree, tree, tsubst_flags_t, tree);
171 static tree tsubst_template_parms (tree, tree, tsubst_flags_t);
172 static void regenerate_decl_from_template (tree, tree);
173 static tree most_specialized_class (tree, tree, tsubst_flags_t);
174 static tree tsubst_aggr_type (tree, tree, tsubst_flags_t, tree, int);
175 static tree tsubst_arg_types (tree, tree, tsubst_flags_t, tree);
176 static tree tsubst_function_type (tree, tree, tsubst_flags_t, tree);
177 static bool check_specialization_scope (void);
178 static tree process_partial_specialization (tree);
179 static void set_current_access_from_decl (tree);
180 static enum template_base_result get_template_base (tree, tree, tree, tree,
182 static tree try_class_unification (tree, tree, tree, tree, bool);
183 static int coerce_template_template_parms (tree, tree, tsubst_flags_t,
185 static bool template_template_parm_bindings_ok_p (tree, tree);
186 static int template_args_equal (tree, tree);
187 static void tsubst_default_arguments (tree);
188 static tree for_each_template_parm_r (tree *, int *, void *);
189 static tree copy_default_args_to_explicit_spec_1 (tree, tree);
190 static void copy_default_args_to_explicit_spec (tree);
191 static int invalid_nontype_parm_type_p (tree, tsubst_flags_t);
192 static int eq_local_specializations (const void *, const void *);
193 static bool dependent_template_arg_p (tree);
194 static bool any_template_arguments_need_structural_equality_p (tree);
195 static bool dependent_type_p_r (tree);
196 static tree tsubst_expr (tree, tree, tsubst_flags_t, tree, bool);
197 static tree tsubst_copy (tree, tree, tsubst_flags_t, tree);
198 static tree tsubst_pack_expansion (tree, tree, tsubst_flags_t, tree);
199 static tree tsubst_decl (tree, tree, tsubst_flags_t);
200 static void perform_typedefs_access_check (tree tmpl, tree targs);
201 static void append_type_to_template_for_access_check_1 (tree, tree, tree,
203 static tree listify (tree);
204 static tree listify_autos (tree, tree);
205 static tree template_parm_to_arg (tree t);
206 static bool arg_from_parm_pack_p (tree, tree);
207 static tree current_template_args (void);
208 static tree fixup_template_type_parm_type (tree, int);
209 static tree fixup_template_parm_index (tree, tree, int);
210 static tree tsubst_template_parm (tree, tree, tsubst_flags_t);
212 /* Make the current scope suitable for access checking when we are
213 processing T. T can be FUNCTION_DECL for instantiated function
214 template, or VAR_DECL for static member variable (need by
215 instantiate_decl). */
218 push_access_scope (tree t)
220 gcc_assert (TREE_CODE (t) == FUNCTION_DECL
221 || TREE_CODE (t) == VAR_DECL);
223 if (DECL_FRIEND_CONTEXT (t))
224 push_nested_class (DECL_FRIEND_CONTEXT (t));
225 else if (DECL_CLASS_SCOPE_P (t))
226 push_nested_class (DECL_CONTEXT (t));
228 push_to_top_level ();
230 if (TREE_CODE (t) == FUNCTION_DECL)
232 saved_access_scope = tree_cons
233 (NULL_TREE, current_function_decl, saved_access_scope);
234 current_function_decl = t;
238 /* Restore the scope set up by push_access_scope. T is the node we
242 pop_access_scope (tree t)
244 if (TREE_CODE (t) == FUNCTION_DECL)
246 current_function_decl = TREE_VALUE (saved_access_scope);
247 saved_access_scope = TREE_CHAIN (saved_access_scope);
250 if (DECL_FRIEND_CONTEXT (t) || DECL_CLASS_SCOPE_P (t))
253 pop_from_top_level ();
256 /* Do any processing required when DECL (a member template
257 declaration) is finished. Returns the TEMPLATE_DECL corresponding
258 to DECL, unless it is a specialization, in which case the DECL
259 itself is returned. */
262 finish_member_template_decl (tree decl)
264 if (decl == error_mark_node)
265 return error_mark_node;
267 gcc_assert (DECL_P (decl));
269 if (TREE_CODE (decl) == TYPE_DECL)
273 type = TREE_TYPE (decl);
274 if (type == error_mark_node)
275 return error_mark_node;
276 if (MAYBE_CLASS_TYPE_P (type)
277 && CLASSTYPE_TEMPLATE_INFO (type)
278 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
280 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
281 check_member_template (tmpl);
286 else if (TREE_CODE (decl) == FIELD_DECL)
287 error ("data member %qD cannot be a member template", decl);
288 else if (DECL_TEMPLATE_INFO (decl))
290 if (!DECL_TEMPLATE_SPECIALIZATION (decl))
292 check_member_template (DECL_TI_TEMPLATE (decl));
293 return DECL_TI_TEMPLATE (decl);
299 error ("invalid member template declaration %qD", decl);
301 return error_mark_node;
304 /* Create a template info node. */
307 build_template_info (tree template_decl, tree template_args)
309 tree result = make_node (TEMPLATE_INFO);
310 TI_TEMPLATE (result) = template_decl;
311 TI_ARGS (result) = template_args;
315 /* Return the template info node corresponding to T, whatever T is. */
318 get_template_info (const_tree t)
320 tree tinfo = NULL_TREE;
322 if (!t || t == error_mark_node)
325 if (DECL_P (t) && DECL_LANG_SPECIFIC (t))
326 tinfo = DECL_TEMPLATE_INFO (t);
328 if (!tinfo && DECL_IMPLICIT_TYPEDEF_P (t))
331 if (TAGGED_TYPE_P (t))
332 tinfo = TYPE_TEMPLATE_INFO (t);
333 else if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
334 tinfo = TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (t);
339 /* Returns the template nesting level of the indicated class TYPE.
349 A<T>::B<U> has depth two, while A<T> has depth one.
350 Both A<T>::B<int> and A<int>::B<U> have depth one, if
351 they are instantiations, not specializations.
353 This function is guaranteed to return 0 if passed NULL_TREE so
354 that, for example, `template_class_depth (current_class_type)' is
358 template_class_depth (tree type)
363 type && TREE_CODE (type) != NAMESPACE_DECL;
364 type = (TREE_CODE (type) == FUNCTION_DECL)
365 ? CP_DECL_CONTEXT (type) : CP_TYPE_CONTEXT (type))
367 tree tinfo = get_template_info (type);
369 if (tinfo && PRIMARY_TEMPLATE_P (TI_TEMPLATE (tinfo))
370 && uses_template_parms (INNERMOST_TEMPLATE_ARGS (TI_ARGS (tinfo))))
377 /* Subroutine of maybe_begin_member_template_processing.
378 Returns true if processing DECL needs us to push template parms. */
381 inline_needs_template_parms (tree decl)
383 if (! DECL_TEMPLATE_INFO (decl))
386 return (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (most_general_template (decl)))
387 > (processing_template_decl + DECL_TEMPLATE_SPECIALIZATION (decl)));
390 /* Subroutine of maybe_begin_member_template_processing.
391 Push the template parms in PARMS, starting from LEVELS steps into the
392 chain, and ending at the beginning, since template parms are listed
396 push_inline_template_parms_recursive (tree parmlist, int levels)
398 tree parms = TREE_VALUE (parmlist);
402 push_inline_template_parms_recursive (TREE_CHAIN (parmlist), levels - 1);
404 ++processing_template_decl;
405 current_template_parms
406 = tree_cons (size_int (processing_template_decl),
407 parms, current_template_parms);
408 TEMPLATE_PARMS_FOR_INLINE (current_template_parms) = 1;
410 begin_scope (TREE_VEC_LENGTH (parms) ? sk_template_parms : sk_template_spec,
412 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
414 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
416 if (parm == error_mark_node)
419 gcc_assert (DECL_P (parm));
421 switch (TREE_CODE (parm))
430 /* Make a CONST_DECL as is done in process_template_parm.
431 It is ugly that we recreate this here; the original
432 version built in process_template_parm is no longer
434 tree decl = build_decl (DECL_SOURCE_LOCATION (parm),
435 CONST_DECL, DECL_NAME (parm),
437 DECL_ARTIFICIAL (decl) = 1;
438 TREE_CONSTANT (decl) = 1;
439 TREE_READONLY (decl) = 1;
440 DECL_INITIAL (decl) = DECL_INITIAL (parm);
441 SET_DECL_TEMPLATE_PARM_P (decl);
452 /* Restore the template parameter context for a member template or
453 a friend template defined in a class definition. */
456 maybe_begin_member_template_processing (tree decl)
461 if (inline_needs_template_parms (decl))
463 parms = DECL_TEMPLATE_PARMS (most_general_template (decl));
464 levels = TMPL_PARMS_DEPTH (parms) - processing_template_decl;
466 if (DECL_TEMPLATE_SPECIALIZATION (decl))
469 parms = TREE_CHAIN (parms);
472 push_inline_template_parms_recursive (parms, levels);
475 /* Remember how many levels of template parameters we pushed so that
476 we can pop them later. */
477 VEC_safe_push (int, heap, inline_parm_levels, levels);
480 /* Undo the effects of maybe_begin_member_template_processing. */
483 maybe_end_member_template_processing (void)
488 if (VEC_length (int, inline_parm_levels) == 0)
491 last = VEC_pop (int, inline_parm_levels);
492 for (i = 0; i < last; ++i)
494 --processing_template_decl;
495 current_template_parms = TREE_CHAIN (current_template_parms);
500 /* Return a new template argument vector which contains all of ARGS,
501 but has as its innermost set of arguments the EXTRA_ARGS. */
504 add_to_template_args (tree args, tree extra_args)
511 if (args == NULL_TREE || extra_args == error_mark_node)
514 extra_depth = TMPL_ARGS_DEPTH (extra_args);
515 new_args = make_tree_vec (TMPL_ARGS_DEPTH (args) + extra_depth);
517 for (i = 1; i <= TMPL_ARGS_DEPTH (args); ++i)
518 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (args, i));
520 for (j = 1; j <= extra_depth; ++j, ++i)
521 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (extra_args, j));
526 /* Like add_to_template_args, but only the outermost ARGS are added to
527 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
528 (EXTRA_ARGS) levels are added. This function is used to combine
529 the template arguments from a partial instantiation with the
530 template arguments used to attain the full instantiation from the
531 partial instantiation. */
534 add_outermost_template_args (tree args, tree extra_args)
538 /* If there are more levels of EXTRA_ARGS than there are ARGS,
539 something very fishy is going on. */
540 gcc_assert (TMPL_ARGS_DEPTH (args) >= TMPL_ARGS_DEPTH (extra_args));
542 /* If *all* the new arguments will be the EXTRA_ARGS, just return
544 if (TMPL_ARGS_DEPTH (args) == TMPL_ARGS_DEPTH (extra_args))
547 /* For the moment, we make ARGS look like it contains fewer levels. */
548 TREE_VEC_LENGTH (args) -= TMPL_ARGS_DEPTH (extra_args);
550 new_args = add_to_template_args (args, extra_args);
552 /* Now, we restore ARGS to its full dimensions. */
553 TREE_VEC_LENGTH (args) += TMPL_ARGS_DEPTH (extra_args);
558 /* Return the N levels of innermost template arguments from the ARGS. */
561 get_innermost_template_args (tree args, int n)
569 /* If N is 1, just return the innermost set of template arguments. */
571 return TMPL_ARGS_LEVEL (args, TMPL_ARGS_DEPTH (args));
573 /* If we're not removing anything, just return the arguments we were
575 extra_levels = TMPL_ARGS_DEPTH (args) - n;
576 gcc_assert (extra_levels >= 0);
577 if (extra_levels == 0)
580 /* Make a new set of arguments, not containing the outer arguments. */
581 new_args = make_tree_vec (n);
582 for (i = 1; i <= n; ++i)
583 SET_TMPL_ARGS_LEVEL (new_args, i,
584 TMPL_ARGS_LEVEL (args, i + extra_levels));
589 /* The inverse of get_innermost_template_args: Return all but the innermost
590 EXTRA_LEVELS levels of template arguments from the ARGS. */
593 strip_innermost_template_args (tree args, int extra_levels)
596 int n = TMPL_ARGS_DEPTH (args) - extra_levels;
601 /* If N is 1, just return the outermost set of template arguments. */
603 return TMPL_ARGS_LEVEL (args, 1);
605 /* If we're not removing anything, just return the arguments we were
607 gcc_assert (extra_levels >= 0);
608 if (extra_levels == 0)
611 /* Make a new set of arguments, not containing the inner arguments. */
612 new_args = make_tree_vec (n);
613 for (i = 1; i <= n; ++i)
614 SET_TMPL_ARGS_LEVEL (new_args, i,
615 TMPL_ARGS_LEVEL (args, i));
620 /* We've got a template header coming up; push to a new level for storing
624 begin_template_parm_list (void)
626 /* We use a non-tag-transparent scope here, which causes pushtag to
627 put tags in this scope, rather than in the enclosing class or
628 namespace scope. This is the right thing, since we want
629 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
630 global template class, push_template_decl handles putting the
631 TEMPLATE_DECL into top-level scope. For a nested template class,
634 template <class T> struct S1 {
635 template <class T> struct S2 {};
638 pushtag contains special code to call pushdecl_with_scope on the
639 TEMPLATE_DECL for S2. */
640 begin_scope (sk_template_parms, NULL);
641 ++processing_template_decl;
642 ++processing_template_parmlist;
643 note_template_header (0);
646 /* This routine is called when a specialization is declared. If it is
647 invalid to declare a specialization here, an error is reported and
648 false is returned, otherwise this routine will return true. */
651 check_specialization_scope (void)
653 tree scope = current_scope ();
657 An explicit specialization shall be declared in the namespace of
658 which the template is a member, or, for member templates, in the
659 namespace of which the enclosing class or enclosing class
660 template is a member. An explicit specialization of a member
661 function, member class or static data member of a class template
662 shall be declared in the namespace of which the class template
664 if (scope && TREE_CODE (scope) != NAMESPACE_DECL)
666 error ("explicit specialization in non-namespace scope %qD", scope);
672 In an explicit specialization declaration for a member of a class
673 template or a member template that appears in namespace scope,
674 the member template and some of its enclosing class templates may
675 remain unspecialized, except that the declaration shall not
676 explicitly specialize a class member template if its enclosing
677 class templates are not explicitly specialized as well. */
678 if (current_template_parms)
680 error ("enclosing class templates are not explicitly specialized");
687 /* We've just seen template <>. */
690 begin_specialization (void)
692 begin_scope (sk_template_spec, NULL);
693 note_template_header (1);
694 return check_specialization_scope ();
697 /* Called at then end of processing a declaration preceded by
701 end_specialization (void)
704 reset_specialization ();
707 /* Any template <>'s that we have seen thus far are not referring to a
708 function specialization. */
711 reset_specialization (void)
713 processing_specialization = 0;
714 template_header_count = 0;
717 /* We've just seen a template header. If SPECIALIZATION is nonzero,
718 it was of the form template <>. */
721 note_template_header (int specialization)
723 processing_specialization = specialization;
724 template_header_count++;
727 /* We're beginning an explicit instantiation. */
730 begin_explicit_instantiation (void)
732 gcc_assert (!processing_explicit_instantiation);
733 processing_explicit_instantiation = true;
738 end_explicit_instantiation (void)
740 gcc_assert (processing_explicit_instantiation);
741 processing_explicit_instantiation = false;
744 /* An explicit specialization or partial specialization TMPL is being
745 declared. Check that the namespace in which the specialization is
746 occurring is permissible. Returns false iff it is invalid to
747 specialize TMPL in the current namespace. */
750 check_specialization_namespace (tree tmpl)
752 tree tpl_ns = decl_namespace_context (tmpl);
756 An explicit specialization shall be declared in the namespace of
757 which the template is a member, or, for member templates, in the
758 namespace of which the enclosing class or enclosing class
759 template is a member. An explicit specialization of a member
760 function, member class or static data member of a class template
761 shall be declared in the namespace of which the class template is
763 if (current_scope() != DECL_CONTEXT (tmpl)
764 && !at_namespace_scope_p ())
766 error ("specialization of %qD must appear at namespace scope", tmpl);
769 if (is_associated_namespace (current_namespace, tpl_ns))
770 /* Same or super-using namespace. */
774 permerror (input_location, "specialization of %qD in different namespace", tmpl);
775 permerror (input_location, " from definition of %q+#D", tmpl);
780 /* SPEC is an explicit instantiation. Check that it is valid to
781 perform this explicit instantiation in the current namespace. */
784 check_explicit_instantiation_namespace (tree spec)
788 /* DR 275: An explicit instantiation shall appear in an enclosing
789 namespace of its template. */
790 ns = decl_namespace_context (spec);
791 if (!is_ancestor (current_namespace, ns))
792 permerror (input_location, "explicit instantiation of %qD in namespace %qD "
793 "(which does not enclose namespace %qD)",
794 spec, current_namespace, ns);
797 /* The TYPE is being declared. If it is a template type, that means it
798 is a partial specialization. Do appropriate error-checking. */
801 maybe_process_partial_specialization (tree type)
805 if (type == error_mark_node)
806 return error_mark_node;
808 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
810 error ("name of class shadows template template parameter %qD",
812 return error_mark_node;
815 context = TYPE_CONTEXT (type);
817 if ((CLASS_TYPE_P (type) && CLASSTYPE_USE_TEMPLATE (type))
818 /* Consider non-class instantiations of alias templates as
821 && TYPE_TEMPLATE_INFO (type)
822 && DECL_LANG_SPECIFIC (TYPE_NAME (type))
823 && DECL_USE_TEMPLATE (TYPE_NAME (type))))
825 /* This is for ordinary explicit specialization and partial
826 specialization of a template class such as:
828 template <> class C<int>;
832 template <class T> class C<T*>;
834 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
836 if (CLASS_TYPE_P (type)
837 && CLASSTYPE_IMPLICIT_INSTANTIATION (type)
838 && !COMPLETE_TYPE_P (type))
840 check_specialization_namespace (CLASSTYPE_TI_TEMPLATE (type));
841 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
842 if (processing_template_decl)
844 if (push_template_decl (TYPE_MAIN_DECL (type))
846 return error_mark_node;
849 else if (CLASS_TYPE_P (type)
850 && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
851 error ("specialization of %qT after instantiation", type);
853 if (DECL_ALIAS_TEMPLATE_P (TYPE_TI_TEMPLATE (type)))
855 error ("partial specialization of alias template %qD",
856 TYPE_TI_TEMPLATE (type));
857 return error_mark_node;
860 else if (CLASS_TYPE_P (type)
861 && !CLASSTYPE_USE_TEMPLATE (type)
862 && CLASSTYPE_TEMPLATE_INFO (type)
863 && context && CLASS_TYPE_P (context)
864 && CLASSTYPE_TEMPLATE_INFO (context))
866 /* This is for an explicit specialization of member class
867 template according to [temp.expl.spec/18]:
869 template <> template <class U> class C<int>::D;
871 The context `C<int>' must be an implicit instantiation.
872 Otherwise this is just a member class template declared
875 template <> class C<int> { template <class U> class D; };
876 template <> template <class U> class C<int>::D;
878 In the first case, `C<int>::D' is a specialization of `C<T>::D'
879 while in the second case, `C<int>::D' is a primary template
880 and `C<T>::D' may not exist. */
882 if (CLASSTYPE_IMPLICIT_INSTANTIATION (context)
883 && !COMPLETE_TYPE_P (type))
886 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
888 if (current_namespace
889 != decl_namespace_context (tmpl))
891 permerror (input_location, "specializing %q#T in different namespace", type);
892 permerror (input_location, " from definition of %q+#D", tmpl);
895 /* Check for invalid specialization after instantiation:
897 template <> template <> class C<int>::D<int>;
898 template <> template <class U> class C<int>::D; */
900 for (t = DECL_TEMPLATE_INSTANTIATIONS (tmpl);
901 t; t = TREE_CHAIN (t))
903 tree inst = TREE_VALUE (t);
904 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (inst))
906 /* We already have a full specialization of this partial
907 instantiation. Reassign it to the new member
908 specialization template. */
913 elt.tmpl = most_general_template (tmpl);
914 elt.args = CLASSTYPE_TI_ARGS (inst);
917 htab_remove_elt (type_specializations, &elt);
920 elt.args = INNERMOST_TEMPLATE_ARGS (elt.args);
922 slot = htab_find_slot (type_specializations, &elt, INSERT);
923 entry = ggc_alloc_spec_entry ();
927 else if (COMPLETE_OR_OPEN_TYPE_P (inst))
928 /* But if we've had an implicit instantiation, that's a
929 problem ([temp.expl.spec]/6). */
930 error ("specialization %qT after instantiation %qT",
934 /* Mark TYPE as a specialization. And as a result, we only
935 have one level of template argument for the innermost
937 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
938 CLASSTYPE_TI_ARGS (type)
939 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type));
942 else if (processing_specialization)
944 /* Someday C++0x may allow for enum template specialization. */
945 if (cxx_dialect > cxx98 && TREE_CODE (type) == ENUMERAL_TYPE
946 && CLASS_TYPE_P (context) && CLASSTYPE_USE_TEMPLATE (context))
947 pedwarn (input_location, OPT_pedantic, "template specialization "
948 "of %qD not allowed by ISO C++", type);
951 error ("explicit specialization of non-template %qT", type);
952 return error_mark_node;
959 /* Returns nonzero if we can optimize the retrieval of specializations
960 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
961 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
964 optimize_specialization_lookup_p (tree tmpl)
966 return (DECL_FUNCTION_TEMPLATE_P (tmpl)
967 && DECL_CLASS_SCOPE_P (tmpl)
968 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
970 && CLASS_TYPE_P (DECL_CONTEXT (tmpl))
971 /* The optimized lookup depends on the fact that the
972 template arguments for the member function template apply
973 purely to the containing class, which is not true if the
974 containing class is an explicit or partial
976 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (tmpl))
977 && !DECL_MEMBER_TEMPLATE_P (tmpl)
978 && !DECL_CONV_FN_P (tmpl)
979 /* It is possible to have a template that is not a member
980 template and is not a member of a template class:
982 template <typename T>
983 struct S { friend A::f(); };
985 Here, the friend function is a template, but the context does
986 not have template information. The optimized lookup relies
987 on having ARGS be the template arguments for both the class
988 and the function template. */
989 && !DECL_FRIEND_P (DECL_TEMPLATE_RESULT (tmpl)));
992 /* Retrieve the specialization (in the sense of [temp.spec] - a
993 specialization is either an instantiation or an explicit
994 specialization) of TMPL for the given template ARGS. If there is
995 no such specialization, return NULL_TREE. The ARGS are a vector of
996 arguments, or a vector of vectors of arguments, in the case of
997 templates with more than one level of parameters.
999 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
1000 then we search for a partial specialization matching ARGS. This
1001 parameter is ignored if TMPL is not a class template. */
1004 retrieve_specialization (tree tmpl, tree args, hashval_t hash)
1006 if (args == error_mark_node)
1009 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
1011 /* There should be as many levels of arguments as there are
1012 levels of parameters. */
1013 gcc_assert (TMPL_ARGS_DEPTH (args)
1014 == TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl)));
1016 if (optimize_specialization_lookup_p (tmpl))
1018 tree class_template;
1019 tree class_specialization;
1020 VEC(tree,gc) *methods;
1024 /* The template arguments actually apply to the containing
1025 class. Find the class specialization with those
1027 class_template = CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (tmpl));
1028 class_specialization
1029 = retrieve_specialization (class_template, args, 0);
1030 if (!class_specialization)
1032 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
1033 for the specialization. */
1034 idx = class_method_index_for_fn (class_specialization, tmpl);
1037 /* Iterate through the methods with the indicated name, looking
1038 for the one that has an instance of TMPL. */
1039 methods = CLASSTYPE_METHOD_VEC (class_specialization);
1040 for (fns = VEC_index (tree, methods, idx); fns; fns = OVL_NEXT (fns))
1042 tree fn = OVL_CURRENT (fns);
1043 if (DECL_TEMPLATE_INFO (fn) && DECL_TI_TEMPLATE (fn) == tmpl
1044 /* using-declarations can add base methods to the method vec,
1045 and we don't want those here. */
1046 && DECL_CONTEXT (fn) == class_specialization)
1055 htab_t specializations;
1059 elt.spec = NULL_TREE;
1061 if (DECL_CLASS_TEMPLATE_P (tmpl))
1062 specializations = type_specializations;
1064 specializations = decl_specializations;
1067 hash = hash_specialization (&elt);
1068 found = (spec_entry *) htab_find_with_hash (specializations, &elt, hash);
1076 /* Like retrieve_specialization, but for local declarations. */
1079 retrieve_local_specialization (tree tmpl)
1083 if (local_specializations == NULL)
1086 spec = (tree) htab_find_with_hash (local_specializations, tmpl,
1087 htab_hash_pointer (tmpl));
1088 return spec ? TREE_PURPOSE (spec) : NULL_TREE;
1091 /* Returns nonzero iff DECL is a specialization of TMPL. */
1094 is_specialization_of (tree decl, tree tmpl)
1098 if (TREE_CODE (decl) == FUNCTION_DECL)
1102 t = DECL_TEMPLATE_INFO (t) ? DECL_TI_TEMPLATE (t) : NULL_TREE)
1108 gcc_assert (TREE_CODE (decl) == TYPE_DECL);
1110 for (t = TREE_TYPE (decl);
1112 t = CLASSTYPE_USE_TEMPLATE (t)
1113 ? TREE_TYPE (CLASSTYPE_TI_TEMPLATE (t)) : NULL_TREE)
1114 if (same_type_ignoring_top_level_qualifiers_p (t, TREE_TYPE (tmpl)))
1121 /* Returns nonzero iff DECL is a specialization of friend declaration
1122 FRIEND_DECL according to [temp.friend]. */
1125 is_specialization_of_friend (tree decl, tree friend_decl)
1127 bool need_template = true;
1130 gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
1131 || TREE_CODE (decl) == TYPE_DECL);
1133 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1134 of a template class, we want to check if DECL is a specialization
1136 if (TREE_CODE (friend_decl) == FUNCTION_DECL
1137 && DECL_TEMPLATE_INFO (friend_decl)
1138 && !DECL_USE_TEMPLATE (friend_decl))
1140 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1141 friend_decl = DECL_TI_TEMPLATE (friend_decl);
1142 need_template = false;
1144 else if (TREE_CODE (friend_decl) == TEMPLATE_DECL
1145 && !PRIMARY_TEMPLATE_P (friend_decl))
1146 need_template = false;
1148 /* There is nothing to do if this is not a template friend. */
1149 if (TREE_CODE (friend_decl) != TEMPLATE_DECL)
1152 if (is_specialization_of (decl, friend_decl))
1156 A member of a class template may be declared to be a friend of a
1157 non-template class. In this case, the corresponding member of
1158 every specialization of the class template is a friend of the
1159 class granting friendship.
1161 For example, given a template friend declaration
1163 template <class T> friend void A<T>::f();
1165 the member function below is considered a friend
1167 template <> struct A<int> {
1171 For this type of template friend, TEMPLATE_DEPTH below will be
1172 nonzero. To determine if DECL is a friend of FRIEND, we first
1173 check if the enclosing class is a specialization of another. */
1175 template_depth = template_class_depth (CP_DECL_CONTEXT (friend_decl));
1177 && DECL_CLASS_SCOPE_P (decl)
1178 && is_specialization_of (TYPE_NAME (DECL_CONTEXT (decl)),
1179 CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (friend_decl))))
1181 /* Next, we check the members themselves. In order to handle
1182 a few tricky cases, such as when FRIEND_DECL's are
1184 template <class T> friend void A<T>::g(T t);
1185 template <class T> template <T t> friend void A<T>::h();
1189 void A<int>::g(int);
1190 template <int> void A<int>::h();
1192 we need to figure out ARGS, the template arguments from
1193 the context of DECL. This is required for template substitution
1194 of `T' in the function parameter of `g' and template parameter
1195 of `h' in the above examples. Here ARGS corresponds to `int'. */
1197 tree context = DECL_CONTEXT (decl);
1198 tree args = NULL_TREE;
1199 int current_depth = 0;
1201 while (current_depth < template_depth)
1203 if (CLASSTYPE_TEMPLATE_INFO (context))
1205 if (current_depth == 0)
1206 args = TYPE_TI_ARGS (context);
1208 args = add_to_template_args (TYPE_TI_ARGS (context), args);
1211 context = TYPE_CONTEXT (context);
1214 if (TREE_CODE (decl) == FUNCTION_DECL)
1219 tree friend_args_type;
1220 tree decl_args_type;
1222 /* Make sure that both DECL and FRIEND_DECL are templates or
1224 is_template = DECL_TEMPLATE_INFO (decl)
1225 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (decl));
1226 if (need_template ^ is_template)
1228 else if (is_template)
1230 /* If both are templates, check template parameter list. */
1232 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1234 if (!comp_template_parms
1235 (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (decl)),
1239 decl_type = TREE_TYPE (DECL_TI_TEMPLATE (decl));
1242 decl_type = TREE_TYPE (decl);
1244 friend_type = tsubst_function_type (TREE_TYPE (friend_decl), args,
1245 tf_none, NULL_TREE);
1246 if (friend_type == error_mark_node)
1249 /* Check if return types match. */
1250 if (!same_type_p (TREE_TYPE (decl_type), TREE_TYPE (friend_type)))
1253 /* Check if function parameter types match, ignoring the
1254 `this' parameter. */
1255 friend_args_type = TYPE_ARG_TYPES (friend_type);
1256 decl_args_type = TYPE_ARG_TYPES (decl_type);
1257 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (friend_decl))
1258 friend_args_type = TREE_CHAIN (friend_args_type);
1259 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1260 decl_args_type = TREE_CHAIN (decl_args_type);
1262 return compparms (decl_args_type, friend_args_type);
1266 /* DECL is a TYPE_DECL */
1268 tree decl_type = TREE_TYPE (decl);
1270 /* Make sure that both DECL and FRIEND_DECL are templates or
1273 = CLASSTYPE_TEMPLATE_INFO (decl_type)
1274 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (decl_type));
1276 if (need_template ^ is_template)
1278 else if (is_template)
1281 /* If both are templates, check the name of the two
1282 TEMPLATE_DECL's first because is_friend didn't. */
1283 if (DECL_NAME (CLASSTYPE_TI_TEMPLATE (decl_type))
1284 != DECL_NAME (friend_decl))
1287 /* Now check template parameter list. */
1289 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1291 return comp_template_parms
1292 (DECL_TEMPLATE_PARMS (CLASSTYPE_TI_TEMPLATE (decl_type)),
1296 return (DECL_NAME (decl)
1297 == DECL_NAME (friend_decl));
1303 /* Register the specialization SPEC as a specialization of TMPL with
1304 the indicated ARGS. IS_FRIEND indicates whether the specialization
1305 is actually just a friend declaration. Returns SPEC, or an
1306 equivalent prior declaration, if available. */
1309 register_specialization (tree spec, tree tmpl, tree args, bool is_friend,
1316 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL && DECL_P (spec));
1318 if (TREE_CODE (spec) == FUNCTION_DECL
1319 && uses_template_parms (DECL_TI_ARGS (spec)))
1320 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1321 register it; we want the corresponding TEMPLATE_DECL instead.
1322 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1323 the more obvious `uses_template_parms (spec)' to avoid problems
1324 with default function arguments. In particular, given
1325 something like this:
1327 template <class T> void f(T t1, T t = T())
1329 the default argument expression is not substituted for in an
1330 instantiation unless and until it is actually needed. */
1333 if (optimize_specialization_lookup_p (tmpl))
1334 /* We don't put these specializations in the hash table, but we might
1335 want to give an error about a mismatch. */
1336 fn = retrieve_specialization (tmpl, args, 0);
1344 hash = hash_specialization (&elt);
1347 htab_find_slot_with_hash (decl_specializations, &elt, hash, INSERT);
1349 fn = ((spec_entry *) *slot)->spec;
1354 /* We can sometimes try to re-register a specialization that we've
1355 already got. In particular, regenerate_decl_from_template calls
1356 duplicate_decls which will update the specialization list. But,
1357 we'll still get called again here anyhow. It's more convenient
1358 to simply allow this than to try to prevent it. */
1361 else if (fn && DECL_TEMPLATE_SPECIALIZATION (spec))
1363 if (DECL_TEMPLATE_INSTANTIATION (fn))
1365 if (DECL_ODR_USED (fn)
1366 || DECL_EXPLICIT_INSTANTIATION (fn))
1368 error ("specialization of %qD after instantiation",
1370 return error_mark_node;
1375 /* This situation should occur only if the first
1376 specialization is an implicit instantiation, the
1377 second is an explicit specialization, and the
1378 implicit instantiation has not yet been used. That
1379 situation can occur if we have implicitly
1380 instantiated a member function and then specialized
1383 We can also wind up here if a friend declaration that
1384 looked like an instantiation turns out to be a
1387 template <class T> void foo(T);
1388 class S { friend void foo<>(int) };
1389 template <> void foo(int);
1391 We transform the existing DECL in place so that any
1392 pointers to it become pointers to the updated
1395 If there was a definition for the template, but not
1396 for the specialization, we want this to look as if
1397 there were no definition, and vice versa. */
1398 DECL_INITIAL (fn) = NULL_TREE;
1399 duplicate_decls (spec, fn, is_friend);
1400 /* The call to duplicate_decls will have applied
1403 An explicit specialization of a function template
1404 is inline only if it is explicitly declared to be,
1405 and independently of whether its function template
1408 to the primary function; now copy the inline bits to
1409 the various clones. */
1410 FOR_EACH_CLONE (clone, fn)
1412 DECL_DECLARED_INLINE_P (clone)
1413 = DECL_DECLARED_INLINE_P (fn);
1414 DECL_SOURCE_LOCATION (clone)
1415 = DECL_SOURCE_LOCATION (fn);
1417 check_specialization_namespace (fn);
1422 else if (DECL_TEMPLATE_SPECIALIZATION (fn))
1424 if (!duplicate_decls (spec, fn, is_friend) && DECL_INITIAL (spec))
1425 /* Dup decl failed, but this is a new definition. Set the
1426 line number so any errors match this new
1428 DECL_SOURCE_LOCATION (fn) = DECL_SOURCE_LOCATION (spec);
1434 return duplicate_decls (spec, fn, is_friend);
1436 /* A specialization must be declared in the same namespace as the
1437 template it is specializing. */
1438 if (DECL_TEMPLATE_SPECIALIZATION (spec)
1439 && !check_specialization_namespace (tmpl))
1440 DECL_CONTEXT (spec) = DECL_CONTEXT (tmpl);
1442 if (slot != NULL /* !optimize_specialization_lookup_p (tmpl) */)
1444 spec_entry *entry = ggc_alloc_spec_entry ();
1445 gcc_assert (tmpl && args && spec);
1448 if (TREE_CODE (spec) == FUNCTION_DECL && DECL_NAMESPACE_SCOPE_P (spec)
1449 && PRIMARY_TEMPLATE_P (tmpl)
1450 && DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (tmpl)) == NULL_TREE)
1451 /* TMPL is a forward declaration of a template function; keep a list
1452 of all specializations in case we need to reassign them to a friend
1453 template later in tsubst_friend_function. */
1454 DECL_TEMPLATE_INSTANTIATIONS (tmpl)
1455 = tree_cons (args, spec, DECL_TEMPLATE_INSTANTIATIONS (tmpl));
1461 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1462 TMPL and ARGS members, ignores SPEC. */
1465 eq_specializations (const void *p1, const void *p2)
1467 const spec_entry *e1 = (const spec_entry *)p1;
1468 const spec_entry *e2 = (const spec_entry *)p2;
1470 return (e1->tmpl == e2->tmpl
1471 && comp_template_args (e1->args, e2->args));
1474 /* Returns a hash for a template TMPL and template arguments ARGS. */
1477 hash_tmpl_and_args (tree tmpl, tree args)
1479 hashval_t val = DECL_UID (tmpl);
1480 return iterative_hash_template_arg (args, val);
1483 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1487 hash_specialization (const void *p)
1489 const spec_entry *e = (const spec_entry *)p;
1490 return hash_tmpl_and_args (e->tmpl, e->args);
1493 /* Recursively calculate a hash value for a template argument ARG, for use
1494 in the hash tables of template specializations. */
1497 iterative_hash_template_arg (tree arg, hashval_t val)
1499 unsigned HOST_WIDE_INT i;
1500 enum tree_code code;
1503 if (arg == NULL_TREE)
1504 return iterative_hash_object (arg, val);
1509 if (TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
1510 /* We can get one of these when re-hashing a previous entry in the middle
1511 of substituting into a pack expansion. Just look through it. */
1512 arg = ARGUMENT_PACK_SELECT_FROM_PACK (arg);
1514 code = TREE_CODE (arg);
1515 tclass = TREE_CODE_CLASS (code);
1517 val = iterative_hash_object (code, val);
1524 case IDENTIFIER_NODE:
1525 return iterative_hash_object (IDENTIFIER_HASH_VALUE (arg), val);
1529 int i, len = TREE_VEC_LENGTH (arg);
1530 for (i = 0; i < len; ++i)
1531 val = iterative_hash_template_arg (TREE_VEC_ELT (arg, i), val);
1535 case TYPE_PACK_EXPANSION:
1536 case EXPR_PACK_EXPANSION:
1537 val = iterative_hash_template_arg (PACK_EXPANSION_PATTERN (arg), val);
1538 return iterative_hash_template_arg (PACK_EXPANSION_EXTRA_ARGS (arg), val);
1540 case TYPE_ARGUMENT_PACK:
1541 case NONTYPE_ARGUMENT_PACK:
1542 return iterative_hash_template_arg (ARGUMENT_PACK_ARGS (arg), val);
1545 for (; arg; arg = TREE_CHAIN (arg))
1546 val = iterative_hash_template_arg (TREE_VALUE (arg), val);
1550 for (; arg; arg = OVL_NEXT (arg))
1551 val = iterative_hash_template_arg (OVL_CURRENT (arg), val);
1557 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg), i, field, value)
1559 val = iterative_hash_template_arg (field, val);
1560 val = iterative_hash_template_arg (value, val);
1566 if (!DECL_ARTIFICIAL (arg))
1568 val = iterative_hash_object (DECL_PARM_INDEX (arg), val);
1569 val = iterative_hash_object (DECL_PARM_LEVEL (arg), val);
1571 return iterative_hash_template_arg (TREE_TYPE (arg), val);
1574 return iterative_hash_template_arg (TARGET_EXPR_INITIAL (arg), val);
1577 val = iterative_hash_template_arg (PTRMEM_CST_CLASS (arg), val);
1578 return iterative_hash_template_arg (PTRMEM_CST_MEMBER (arg), val);
1580 case TEMPLATE_PARM_INDEX:
1581 val = iterative_hash_template_arg
1582 (TREE_TYPE (TEMPLATE_PARM_DECL (arg)), val);
1583 val = iterative_hash_object (TEMPLATE_PARM_LEVEL (arg), val);
1584 return iterative_hash_object (TEMPLATE_PARM_IDX (arg), val);
1587 val = iterative_hash_object (TRAIT_EXPR_KIND (arg), val);
1588 val = iterative_hash_template_arg (TRAIT_EXPR_TYPE1 (arg), val);
1589 return iterative_hash_template_arg (TRAIT_EXPR_TYPE2 (arg), val);
1592 val = iterative_hash_template_arg (BINFO_TYPE (BASELINK_BINFO (arg)),
1594 return iterative_hash_template_arg (DECL_NAME (get_first_fn (arg)),
1598 val = iterative_hash_template_arg (TREE_OPERAND (arg, 0), val);
1599 code = TREE_CODE (TREE_OPERAND (arg, 1));
1600 val = iterative_hash_object (code, val);
1601 return iterative_hash_template_arg (TREE_OPERAND (arg, 2), val);
1604 /* A lambda can't appear in a template arg, but don't crash on
1606 gcc_assert (seen_error ());
1610 case IMPLICIT_CONV_EXPR:
1611 case STATIC_CAST_EXPR:
1612 case REINTERPRET_CAST_EXPR:
1613 case CONST_CAST_EXPR:
1614 case DYNAMIC_CAST_EXPR:
1616 val = iterative_hash_template_arg (TREE_TYPE (arg), val);
1617 /* Now hash operands as usual. */
1627 if (TYPE_CANONICAL (arg))
1628 return iterative_hash_object (TYPE_HASH (TYPE_CANONICAL (arg)),
1630 else if (TREE_CODE (arg) == DECLTYPE_TYPE)
1631 return iterative_hash_template_arg (DECLTYPE_TYPE_EXPR (arg), val);
1632 /* Otherwise just compare the types during lookup. */
1635 case tcc_declaration:
1637 return iterative_hash_expr (arg, val);
1640 gcc_assert (IS_EXPR_CODE_CLASS (tclass));
1642 unsigned n = cp_tree_operand_length (arg);
1643 for (i = 0; i < n; ++i)
1644 val = iterative_hash_template_arg (TREE_OPERAND (arg, i), val);
1652 /* Unregister the specialization SPEC as a specialization of TMPL.
1653 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1654 if the SPEC was listed as a specialization of TMPL.
1656 Note that SPEC has been ggc_freed, so we can't look inside it. */
1659 reregister_specialization (tree spec, tree tinfo, tree new_spec)
1664 elt.tmpl = most_general_template (TI_TEMPLATE (tinfo));
1665 elt.args = TI_ARGS (tinfo);
1666 elt.spec = NULL_TREE;
1668 entry = (spec_entry *) htab_find (decl_specializations, &elt);
1671 gcc_assert (entry->spec == spec || entry->spec == new_spec);
1672 gcc_assert (new_spec != NULL_TREE);
1673 entry->spec = new_spec;
1680 /* Compare an entry in the local specializations hash table P1 (which
1681 is really a pointer to a TREE_LIST) with P2 (which is really a
1685 eq_local_specializations (const void *p1, const void *p2)
1687 return TREE_VALUE ((const_tree) p1) == (const_tree) p2;
1690 /* Hash P1, an entry in the local specializations table. */
1693 hash_local_specialization (const void* p1)
1695 return htab_hash_pointer (TREE_VALUE ((const_tree) p1));
1698 /* Like register_specialization, but for local declarations. We are
1699 registering SPEC, an instantiation of TMPL. */
1702 register_local_specialization (tree spec, tree tmpl)
1706 slot = htab_find_slot_with_hash (local_specializations, tmpl,
1707 htab_hash_pointer (tmpl), INSERT);
1708 *slot = build_tree_list (spec, tmpl);
1711 /* TYPE is a class type. Returns true if TYPE is an explicitly
1712 specialized class. */
1715 explicit_class_specialization_p (tree type)
1717 if (!CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
1719 return !uses_template_parms (CLASSTYPE_TI_ARGS (type));
1722 /* Print the list of functions at FNS, going through all the overloads
1723 for each element of the list. Alternatively, FNS can not be a
1724 TREE_LIST, in which case it will be printed together with all the
1727 MORE and *STR should respectively be FALSE and NULL when the function
1728 is called from the outside. They are used internally on recursive
1729 calls. print_candidates manages the two parameters and leaves NULL
1730 in *STR when it ends. */
1733 print_candidates_1 (tree fns, bool more, const char **str)
1736 char *spaces = NULL;
1738 for (fn = fns; fn; fn = OVL_NEXT (fn))
1739 if (TREE_CODE (fn) == TREE_LIST)
1741 for (fn2 = fn; fn2 != NULL_TREE; fn2 = TREE_CHAIN (fn2))
1742 print_candidates_1 (TREE_VALUE (fn2),
1743 TREE_CHAIN (fn2) || more, str);
1749 /* Pick the prefix string. */
1750 if (!more && !OVL_NEXT (fns))
1752 error ("candidate is: %+#D", OVL_CURRENT (fn));
1756 *str = _("candidates are:");
1757 spaces = get_spaces (*str);
1759 error ("%s %+#D", *str, OVL_CURRENT (fn));
1760 *str = spaces ? spaces : *str;
1770 /* Print the list of candidate FNS in an error message. FNS can also
1771 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1774 print_candidates (tree fns)
1776 const char *str = NULL;
1777 print_candidates_1 (fns, false, &str);
1778 gcc_assert (str == NULL);
1781 /* Returns the template (one of the functions given by TEMPLATE_ID)
1782 which can be specialized to match the indicated DECL with the
1783 explicit template args given in TEMPLATE_ID. The DECL may be
1784 NULL_TREE if none is available. In that case, the functions in
1785 TEMPLATE_ID are non-members.
1787 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1788 specialization of a member template.
1790 The TEMPLATE_COUNT is the number of references to qualifying
1791 template classes that appeared in the name of the function. See
1792 check_explicit_specialization for a more accurate description.
1794 TSK indicates what kind of template declaration (if any) is being
1795 declared. TSK_TEMPLATE indicates that the declaration given by
1796 DECL, though a FUNCTION_DECL, has template parameters, and is
1797 therefore a template function.
1799 The template args (those explicitly specified and those deduced)
1800 are output in a newly created vector *TARGS_OUT.
1802 If it is impossible to determine the result, an error message is
1803 issued. The error_mark_node is returned to indicate failure. */
1806 determine_specialization (tree template_id,
1809 int need_member_template,
1815 tree explicit_targs;
1816 tree candidates = NULL_TREE;
1817 /* A TREE_LIST of templates of which DECL may be a specialization.
1818 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1819 corresponding TREE_PURPOSE is the set of template arguments that,
1820 when used to instantiate the template, would produce a function
1821 with the signature of DECL. */
1822 tree templates = NULL_TREE;
1824 cp_binding_level *b;
1826 *targs_out = NULL_TREE;
1828 if (template_id == error_mark_node || decl == error_mark_node)
1829 return error_mark_node;
1831 fns = TREE_OPERAND (template_id, 0);
1832 explicit_targs = TREE_OPERAND (template_id, 1);
1834 if (fns == error_mark_node)
1835 return error_mark_node;
1837 /* Check for baselinks. */
1838 if (BASELINK_P (fns))
1839 fns = BASELINK_FUNCTIONS (fns);
1841 if (!is_overloaded_fn (fns))
1843 error ("%qD is not a function template", fns);
1844 return error_mark_node;
1847 /* Count the number of template headers specified for this
1850 for (b = current_binding_level;
1851 b->kind == sk_template_parms;
1855 for (; fns; fns = OVL_NEXT (fns))
1857 tree fn = OVL_CURRENT (fns);
1859 if (TREE_CODE (fn) == TEMPLATE_DECL)
1861 tree decl_arg_types;
1865 /* In case of explicit specialization, we need to check if
1866 the number of template headers appearing in the specialization
1867 is correct. This is usually done in check_explicit_specialization,
1868 but the check done there cannot be exhaustive when specializing
1869 member functions. Consider the following code:
1871 template <> void A<int>::f(int);
1872 template <> template <> void A<int>::f(int);
1874 Assuming that A<int> is not itself an explicit specialization
1875 already, the first line specializes "f" which is a non-template
1876 member function, whilst the second line specializes "f" which
1877 is a template member function. So both lines are syntactically
1878 correct, and check_explicit_specialization does not reject
1881 Here, we can do better, as we are matching the specialization
1882 against the declarations. We count the number of template
1883 headers, and we check if they match TEMPLATE_COUNT + 1
1884 (TEMPLATE_COUNT is the number of qualifying template classes,
1885 plus there must be another header for the member template
1888 Notice that if header_count is zero, this is not a
1889 specialization but rather a template instantiation, so there
1890 is no check we can perform here. */
1891 if (header_count && header_count != template_count + 1)
1894 /* Check that the number of template arguments at the
1895 innermost level for DECL is the same as for FN. */
1896 if (current_binding_level->kind == sk_template_parms
1897 && !current_binding_level->explicit_spec_p
1898 && (TREE_VEC_LENGTH (DECL_INNERMOST_TEMPLATE_PARMS (fn))
1899 != TREE_VEC_LENGTH (INNERMOST_TEMPLATE_PARMS
1900 (current_template_parms))))
1903 /* DECL might be a specialization of FN. */
1904 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1905 fn_arg_types = TYPE_ARG_TYPES (TREE_TYPE (fn));
1907 /* For a non-static member function, we need to make sure
1908 that the const qualification is the same. Since
1909 get_bindings does not try to merge the "this" parameter,
1910 we must do the comparison explicitly. */
1911 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
1912 && !same_type_p (TREE_VALUE (fn_arg_types),
1913 TREE_VALUE (decl_arg_types)))
1916 /* Skip the "this" parameter and, for constructors of
1917 classes with virtual bases, the VTT parameter. A
1918 full specialization of a constructor will have a VTT
1919 parameter, but a template never will. */
1921 = skip_artificial_parms_for (decl, decl_arg_types);
1923 = skip_artificial_parms_for (fn, fn_arg_types);
1925 /* Check that the number of function parameters matches.
1927 template <class T> void f(int i = 0);
1928 template <> void f<int>();
1929 The specialization f<int> is invalid but is not caught
1930 by get_bindings below. */
1931 if (cxx_dialect < cxx11
1932 && list_length (fn_arg_types) != list_length (decl_arg_types))
1935 /* Function templates cannot be specializations; there are
1936 no partial specializations of functions. Therefore, if
1937 the type of DECL does not match FN, there is no
1939 if (tsk == tsk_template)
1941 if (compparms (fn_arg_types, decl_arg_types))
1942 candidates = tree_cons (NULL_TREE, fn, candidates);
1946 /* See whether this function might be a specialization of this
1948 targs = get_bindings (fn, decl, explicit_targs, /*check_ret=*/true);
1951 /* We cannot deduce template arguments that when used to
1952 specialize TMPL will produce DECL. */
1955 if (cxx_dialect >= cxx11)
1957 /* Make sure that the deduced arguments actually work. */
1958 insttype = tsubst (TREE_TYPE (fn), targs, tf_none, NULL_TREE);
1959 if (insttype == error_mark_node)
1962 = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (insttype));
1963 if (!compparms (fn_arg_types, decl_arg_types))
1967 /* Save this template, and the arguments deduced. */
1968 templates = tree_cons (targs, fn, templates);
1970 else if (need_member_template)
1971 /* FN is an ordinary member function, and we need a
1972 specialization of a member template. */
1974 else if (TREE_CODE (fn) != FUNCTION_DECL)
1975 /* We can get IDENTIFIER_NODEs here in certain erroneous
1978 else if (!DECL_FUNCTION_MEMBER_P (fn))
1979 /* This is just an ordinary non-member function. Nothing can
1980 be a specialization of that. */
1982 else if (DECL_ARTIFICIAL (fn))
1983 /* Cannot specialize functions that are created implicitly. */
1987 tree decl_arg_types;
1989 /* This is an ordinary member function. However, since
1990 we're here, we can assume it's enclosing class is a
1991 template class. For example,
1993 template <typename T> struct S { void f(); };
1994 template <> void S<int>::f() {}
1996 Here, S<int>::f is a non-template, but S<int> is a
1997 template class. If FN has the same type as DECL, we
1998 might be in business. */
2000 if (!DECL_TEMPLATE_INFO (fn))
2001 /* Its enclosing class is an explicit specialization
2002 of a template class. This is not a candidate. */
2005 if (!same_type_p (TREE_TYPE (TREE_TYPE (decl)),
2006 TREE_TYPE (TREE_TYPE (fn))))
2007 /* The return types differ. */
2010 /* Adjust the type of DECL in case FN is a static member. */
2011 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
2012 if (DECL_STATIC_FUNCTION_P (fn)
2013 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2014 decl_arg_types = TREE_CHAIN (decl_arg_types);
2016 if (compparms (TYPE_ARG_TYPES (TREE_TYPE (fn)),
2019 candidates = tree_cons (NULL_TREE, fn, candidates);
2023 if (templates && TREE_CHAIN (templates))
2029 It is possible for a specialization with a given function
2030 signature to be instantiated from more than one function
2031 template. In such cases, explicit specification of the
2032 template arguments must be used to uniquely identify the
2033 function template specialization being specialized.
2035 Note that here, there's no suggestion that we're supposed to
2036 determine which of the candidate templates is most
2037 specialized. However, we, also have:
2041 Partial ordering of overloaded function template
2042 declarations is used in the following contexts to select
2043 the function template to which a function template
2044 specialization refers:
2046 -- when an explicit specialization refers to a function
2049 So, we do use the partial ordering rules, at least for now.
2050 This extension can only serve to make invalid programs valid,
2051 so it's safe. And, there is strong anecdotal evidence that
2052 the committee intended the partial ordering rules to apply;
2053 the EDG front end has that behavior, and John Spicer claims
2054 that the committee simply forgot to delete the wording in
2055 [temp.expl.spec]. */
2056 tree tmpl = most_specialized_instantiation (templates);
2057 if (tmpl != error_mark_node)
2060 TREE_CHAIN (templates) = NULL_TREE;
2064 if (templates == NULL_TREE && candidates == NULL_TREE)
2066 error ("template-id %qD for %q+D does not match any template "
2067 "declaration", template_id, decl);
2068 if (header_count && header_count != template_count + 1)
2069 inform (input_location, "saw %d %<template<>%>, need %d for "
2070 "specializing a member function template",
2071 header_count, template_count + 1);
2072 return error_mark_node;
2074 else if ((templates && TREE_CHAIN (templates))
2075 || (candidates && TREE_CHAIN (candidates))
2076 || (templates && candidates))
2078 error ("ambiguous template specialization %qD for %q+D",
2080 candidates = chainon (candidates, templates);
2081 print_candidates (candidates);
2082 return error_mark_node;
2085 /* We have one, and exactly one, match. */
2088 tree fn = TREE_VALUE (candidates);
2089 *targs_out = copy_node (DECL_TI_ARGS (fn));
2090 /* DECL is a re-declaration or partial instantiation of a template
2092 if (TREE_CODE (fn) == TEMPLATE_DECL)
2094 /* It was a specialization of an ordinary member function in a
2096 return DECL_TI_TEMPLATE (fn);
2099 /* It was a specialization of a template. */
2100 targs = DECL_TI_ARGS (DECL_TEMPLATE_RESULT (TREE_VALUE (templates)));
2101 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (targs))
2103 *targs_out = copy_node (targs);
2104 SET_TMPL_ARGS_LEVEL (*targs_out,
2105 TMPL_ARGS_DEPTH (*targs_out),
2106 TREE_PURPOSE (templates));
2109 *targs_out = TREE_PURPOSE (templates);
2110 return TREE_VALUE (templates);
2113 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2114 but with the default argument values filled in from those in the
2118 copy_default_args_to_explicit_spec_1 (tree spec_types,
2121 tree new_spec_types;
2126 if (spec_types == void_list_node)
2127 return void_list_node;
2129 /* Substitute into the rest of the list. */
2131 copy_default_args_to_explicit_spec_1 (TREE_CHAIN (spec_types),
2132 TREE_CHAIN (tmpl_types));
2134 /* Add the default argument for this parameter. */
2135 return hash_tree_cons (TREE_PURPOSE (tmpl_types),
2136 TREE_VALUE (spec_types),
2140 /* DECL is an explicit specialization. Replicate default arguments
2141 from the template it specializes. (That way, code like:
2143 template <class T> void f(T = 3);
2144 template <> void f(double);
2147 works, as required.) An alternative approach would be to look up
2148 the correct default arguments at the call-site, but this approach
2149 is consistent with how implicit instantiations are handled. */
2152 copy_default_args_to_explicit_spec (tree decl)
2157 tree new_spec_types;
2161 tree object_type = NULL_TREE;
2162 tree in_charge = NULL_TREE;
2163 tree vtt = NULL_TREE;
2165 /* See if there's anything we need to do. */
2166 tmpl = DECL_TI_TEMPLATE (decl);
2167 tmpl_types = TYPE_ARG_TYPES (TREE_TYPE (DECL_TEMPLATE_RESULT (tmpl)));
2168 for (t = tmpl_types; t; t = TREE_CHAIN (t))
2169 if (TREE_PURPOSE (t))
2174 old_type = TREE_TYPE (decl);
2175 spec_types = TYPE_ARG_TYPES (old_type);
2177 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2179 /* Remove the this pointer, but remember the object's type for
2181 object_type = TREE_TYPE (TREE_VALUE (spec_types));
2182 spec_types = TREE_CHAIN (spec_types);
2183 tmpl_types = TREE_CHAIN (tmpl_types);
2185 if (DECL_HAS_IN_CHARGE_PARM_P (decl))
2187 /* DECL may contain more parameters than TMPL due to the extra
2188 in-charge parameter in constructors and destructors. */
2189 in_charge = spec_types;
2190 spec_types = TREE_CHAIN (spec_types);
2192 if (DECL_HAS_VTT_PARM_P (decl))
2195 spec_types = TREE_CHAIN (spec_types);
2199 /* Compute the merged default arguments. */
2201 copy_default_args_to_explicit_spec_1 (spec_types, tmpl_types);
2203 /* Compute the new FUNCTION_TYPE. */
2207 new_spec_types = hash_tree_cons (TREE_PURPOSE (vtt),
2212 /* Put the in-charge parameter back. */
2213 new_spec_types = hash_tree_cons (TREE_PURPOSE (in_charge),
2214 TREE_VALUE (in_charge),
2217 new_type = build_method_type_directly (object_type,
2218 TREE_TYPE (old_type),
2222 new_type = build_function_type (TREE_TYPE (old_type),
2224 new_type = cp_build_type_attribute_variant (new_type,
2225 TYPE_ATTRIBUTES (old_type));
2226 new_type = build_exception_variant (new_type,
2227 TYPE_RAISES_EXCEPTIONS (old_type));
2228 TREE_TYPE (decl) = new_type;
2231 /* Check to see if the function just declared, as indicated in
2232 DECLARATOR, and in DECL, is a specialization of a function
2233 template. We may also discover that the declaration is an explicit
2234 instantiation at this point.
2236 Returns DECL, or an equivalent declaration that should be used
2237 instead if all goes well. Issues an error message if something is
2238 amiss. Returns error_mark_node if the error is not easily
2241 FLAGS is a bitmask consisting of the following flags:
2243 2: The function has a definition.
2244 4: The function is a friend.
2246 The TEMPLATE_COUNT is the number of references to qualifying
2247 template classes that appeared in the name of the function. For
2250 template <class T> struct S { void f(); };
2253 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2254 classes are not counted in the TEMPLATE_COUNT, so that in
2256 template <class T> struct S {};
2257 template <> struct S<int> { void f(); }
2258 template <> void S<int>::f();
2260 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2261 invalid; there should be no template <>.)
2263 If the function is a specialization, it is marked as such via
2264 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2265 is set up correctly, and it is added to the list of specializations
2266 for that template. */
2269 check_explicit_specialization (tree declarator,
2274 int have_def = flags & 2;
2275 int is_friend = flags & 4;
2276 int specialization = 0;
2277 int explicit_instantiation = 0;
2278 int member_specialization = 0;
2279 tree ctype = DECL_CLASS_CONTEXT (decl);
2280 tree dname = DECL_NAME (decl);
2285 if (!processing_specialization)
2288 tsk = tsk_excessive_parms;
2291 tsk = current_tmpl_spec_kind (template_count);
2296 if (processing_specialization)
2299 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2301 else if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2304 /* This could be something like:
2306 template <class T> void f(T);
2307 class S { friend void f<>(int); } */
2311 /* This case handles bogus declarations like template <>
2312 template <class T> void f<int>(); */
2314 error ("template-id %qD in declaration of primary template",
2321 case tsk_invalid_member_spec:
2322 /* The error has already been reported in
2323 check_specialization_scope. */
2324 return error_mark_node;
2326 case tsk_invalid_expl_inst:
2327 error ("template parameter list used in explicit instantiation");
2333 error ("definition provided for explicit instantiation");
2335 explicit_instantiation = 1;
2338 case tsk_excessive_parms:
2339 case tsk_insufficient_parms:
2340 if (tsk == tsk_excessive_parms)
2341 error ("too many template parameter lists in declaration of %qD",
2343 else if (template_header_count)
2344 error("too few template parameter lists in declaration of %qD", decl);
2346 error("explicit specialization of %qD must be introduced by "
2347 "%<template <>%>", decl);
2351 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2353 member_specialization = 1;
2359 if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2361 /* This case handles bogus declarations like template <>
2362 template <class T> void f<int>(); */
2364 if (uses_template_parms (declarator))
2365 error ("function template partial specialization %qD "
2366 "is not allowed", declarator);
2368 error ("template-id %qD in declaration of primary template",
2373 if (ctype && CLASSTYPE_TEMPLATE_INSTANTIATION (ctype))
2374 /* This is a specialization of a member template, without
2375 specialization the containing class. Something like:
2377 template <class T> struct S {
2378 template <class U> void f (U);
2380 template <> template <class U> void S<int>::f(U) {}
2382 That's a specialization -- but of the entire template. */
2390 if (specialization || member_specialization)
2392 tree t = TYPE_ARG_TYPES (TREE_TYPE (decl));
2393 for (; t; t = TREE_CHAIN (t))
2394 if (TREE_PURPOSE (t))
2396 permerror (input_location,
2397 "default argument specified in explicit specialization");
2402 if (specialization || member_specialization || explicit_instantiation)
2404 tree tmpl = NULL_TREE;
2405 tree targs = NULL_TREE;
2407 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2408 if (TREE_CODE (declarator) != TEMPLATE_ID_EXPR)
2412 gcc_assert (TREE_CODE (declarator) == IDENTIFIER_NODE);
2417 /* If there is no class context, the explicit instantiation
2418 must be at namespace scope. */
2419 gcc_assert (DECL_NAMESPACE_SCOPE_P (decl));
2421 /* Find the namespace binding, using the declaration
2423 fns = lookup_qualified_name (CP_DECL_CONTEXT (decl), dname,
2425 if (fns == error_mark_node || !is_overloaded_fn (fns))
2427 error ("%qD is not a template function", dname);
2428 fns = error_mark_node;
2432 tree fn = OVL_CURRENT (fns);
2433 if (!is_associated_namespace (CP_DECL_CONTEXT (decl),
2434 CP_DECL_CONTEXT (fn)))
2435 error ("%qD is not declared in %qD",
2436 decl, current_namespace);
2440 declarator = lookup_template_function (fns, NULL_TREE);
2443 if (declarator == error_mark_node)
2444 return error_mark_node;
2446 if (ctype != NULL_TREE && TYPE_BEING_DEFINED (ctype))
2448 if (!explicit_instantiation)
2449 /* A specialization in class scope. This is invalid,
2450 but the error will already have been flagged by
2451 check_specialization_scope. */
2452 return error_mark_node;
2455 /* It's not valid to write an explicit instantiation in
2458 class C { template void f(); }
2460 This case is caught by the parser. However, on
2463 template class C { void f(); };
2465 (which is invalid) we can get here. The error will be
2472 else if (ctype != NULL_TREE
2473 && (TREE_CODE (TREE_OPERAND (declarator, 0)) ==
2476 /* Find the list of functions in ctype that have the same
2477 name as the declared function. */
2478 tree name = TREE_OPERAND (declarator, 0);
2479 tree fns = NULL_TREE;
2482 if (constructor_name_p (name, ctype))
2484 int is_constructor = DECL_CONSTRUCTOR_P (decl);
2486 if (is_constructor ? !TYPE_HAS_USER_CONSTRUCTOR (ctype)
2487 : !CLASSTYPE_DESTRUCTORS (ctype))
2489 /* From [temp.expl.spec]:
2491 If such an explicit specialization for the member
2492 of a class template names an implicitly-declared
2493 special member function (clause _special_), the
2494 program is ill-formed.
2496 Similar language is found in [temp.explicit]. */
2497 error ("specialization of implicitly-declared special member function");
2498 return error_mark_node;
2501 name = is_constructor ? ctor_identifier : dtor_identifier;
2504 if (!DECL_CONV_FN_P (decl))
2506 idx = lookup_fnfields_1 (ctype, name);
2508 fns = VEC_index (tree, CLASSTYPE_METHOD_VEC (ctype), idx);
2512 VEC(tree,gc) *methods;
2515 /* For a type-conversion operator, we cannot do a
2516 name-based lookup. We might be looking for `operator
2517 int' which will be a specialization of `operator T'.
2518 So, we find *all* the conversion operators, and then
2519 select from them. */
2522 methods = CLASSTYPE_METHOD_VEC (ctype);
2524 for (idx = CLASSTYPE_FIRST_CONVERSION_SLOT;
2525 VEC_iterate (tree, methods, idx, ovl);
2528 if (!DECL_CONV_FN_P (OVL_CURRENT (ovl)))
2529 /* There are no more conversion functions. */
2532 /* Glue all these conversion functions together
2533 with those we already have. */
2534 for (; ovl; ovl = OVL_NEXT (ovl))
2535 fns = ovl_cons (OVL_CURRENT (ovl), fns);
2539 if (fns == NULL_TREE)
2541 error ("no member function %qD declared in %qT", name, ctype);
2542 return error_mark_node;
2545 TREE_OPERAND (declarator, 0) = fns;
2548 /* Figure out what exactly is being specialized at this point.
2549 Note that for an explicit instantiation, even one for a
2550 member function, we cannot tell apriori whether the
2551 instantiation is for a member template, or just a member
2552 function of a template class. Even if a member template is
2553 being instantiated, the member template arguments may be
2554 elided if they can be deduced from the rest of the
2556 tmpl = determine_specialization (declarator, decl,
2558 member_specialization,
2562 if (!tmpl || tmpl == error_mark_node)
2563 /* We couldn't figure out what this declaration was
2565 return error_mark_node;
2568 tree gen_tmpl = most_general_template (tmpl);
2570 if (explicit_instantiation)
2572 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2573 is done by do_decl_instantiation later. */
2575 int arg_depth = TMPL_ARGS_DEPTH (targs);
2576 int parm_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
2578 if (arg_depth > parm_depth)
2580 /* If TMPL is not the most general template (for
2581 example, if TMPL is a friend template that is
2582 injected into namespace scope), then there will
2583 be too many levels of TARGS. Remove some of them
2588 new_targs = make_tree_vec (parm_depth);
2589 for (i = arg_depth - parm_depth; i < arg_depth; ++i)
2590 TREE_VEC_ELT (new_targs, i - (arg_depth - parm_depth))
2591 = TREE_VEC_ELT (targs, i);
2595 return instantiate_template (tmpl, targs, tf_error);
2598 /* If we thought that the DECL was a member function, but it
2599 turns out to be specializing a static member function,
2600 make DECL a static member function as well. */
2601 if (DECL_STATIC_FUNCTION_P (tmpl)
2602 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2603 revert_static_member_fn (decl);
2605 /* If this is a specialization of a member template of a
2606 template class, we want to return the TEMPLATE_DECL, not
2607 the specialization of it. */
2608 if (tsk == tsk_template)
2610 tree result = DECL_TEMPLATE_RESULT (tmpl);
2611 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
2612 DECL_INITIAL (result) = NULL_TREE;
2616 DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl);
2617 DECL_SOURCE_LOCATION (result)
2618 = DECL_SOURCE_LOCATION (decl);
2619 /* We want to use the argument list specified in the
2620 definition, not in the original declaration. */
2621 DECL_ARGUMENTS (result) = DECL_ARGUMENTS (decl);
2622 for (parm = DECL_ARGUMENTS (result); parm;
2623 parm = DECL_CHAIN (parm))
2624 DECL_CONTEXT (parm) = result;
2626 return register_specialization (tmpl, gen_tmpl, targs,
2630 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2631 DECL_TEMPLATE_INFO (decl) = build_template_info (tmpl, targs);
2633 /* Inherit default function arguments from the template
2634 DECL is specializing. */
2635 copy_default_args_to_explicit_spec (decl);
2637 /* This specialization has the same protection as the
2638 template it specializes. */
2639 TREE_PRIVATE (decl) = TREE_PRIVATE (gen_tmpl);
2640 TREE_PROTECTED (decl) = TREE_PROTECTED (gen_tmpl);
2642 /* 7.1.1-1 [dcl.stc]
2644 A storage-class-specifier shall not be specified in an
2645 explicit specialization...
2647 The parser rejects these, so unless action is taken here,
2648 explicit function specializations will always appear with
2651 The action recommended by the C++ CWG in response to C++
2652 defect report 605 is to make the storage class and linkage
2653 of the explicit specialization match the templated function:
2655 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2657 if (tsk == tsk_expl_spec && DECL_FUNCTION_TEMPLATE_P (gen_tmpl))
2659 tree tmpl_func = DECL_TEMPLATE_RESULT (gen_tmpl);
2660 gcc_assert (TREE_CODE (tmpl_func) == FUNCTION_DECL);
2662 /* This specialization has the same linkage and visibility as
2663 the function template it specializes. */
2664 TREE_PUBLIC (decl) = TREE_PUBLIC (tmpl_func);
2665 if (! TREE_PUBLIC (decl))
2667 DECL_INTERFACE_KNOWN (decl) = 1;
2668 DECL_NOT_REALLY_EXTERN (decl) = 1;
2670 DECL_THIS_STATIC (decl) = DECL_THIS_STATIC (tmpl_func);
2671 if (DECL_VISIBILITY_SPECIFIED (tmpl_func))
2673 DECL_VISIBILITY_SPECIFIED (decl) = 1;
2674 DECL_VISIBILITY (decl) = DECL_VISIBILITY (tmpl_func);
2678 /* If DECL is a friend declaration, declared using an
2679 unqualified name, the namespace associated with DECL may
2680 have been set incorrectly. For example, in:
2682 template <typename T> void f(T);
2684 struct S { friend void f<int>(int); }
2687 we will have set the DECL_CONTEXT for the friend
2688 declaration to N, rather than to the global namespace. */
2689 if (DECL_NAMESPACE_SCOPE_P (decl))
2690 DECL_CONTEXT (decl) = DECL_CONTEXT (tmpl);
2692 if (is_friend && !have_def)
2693 /* This is not really a declaration of a specialization.
2694 It's just the name of an instantiation. But, it's not
2695 a request for an instantiation, either. */
2696 SET_DECL_IMPLICIT_INSTANTIATION (decl);
2697 else if (DECL_CONSTRUCTOR_P (decl) || DECL_DESTRUCTOR_P (decl))
2698 /* This is indeed a specialization. In case of constructors
2699 and destructors, we need in-charge and not-in-charge
2700 versions in V3 ABI. */
2701 clone_function_decl (decl, /*update_method_vec_p=*/0);
2703 /* Register this specialization so that we can find it
2705 decl = register_specialization (decl, gen_tmpl, targs, is_friend, 0);
2712 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2713 parameters. These are represented in the same format used for
2714 DECL_TEMPLATE_PARMS. */
2717 comp_template_parms (const_tree parms1, const_tree parms2)
2722 if (parms1 == parms2)
2725 for (p1 = parms1, p2 = parms2;
2726 p1 != NULL_TREE && p2 != NULL_TREE;
2727 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2))
2729 tree t1 = TREE_VALUE (p1);
2730 tree t2 = TREE_VALUE (p2);
2733 gcc_assert (TREE_CODE (t1) == TREE_VEC);
2734 gcc_assert (TREE_CODE (t2) == TREE_VEC);
2736 if (TREE_VEC_LENGTH (t1) != TREE_VEC_LENGTH (t2))
2739 for (i = 0; i < TREE_VEC_LENGTH (t2); ++i)
2741 tree parm1 = TREE_VALUE (TREE_VEC_ELT (t1, i));
2742 tree parm2 = TREE_VALUE (TREE_VEC_ELT (t2, i));
2744 /* If either of the template parameters are invalid, assume
2745 they match for the sake of error recovery. */
2746 if (parm1 == error_mark_node || parm2 == error_mark_node)
2749 if (TREE_CODE (parm1) != TREE_CODE (parm2))
2752 if (TREE_CODE (parm1) == TEMPLATE_TYPE_PARM
2753 && (TEMPLATE_TYPE_PARAMETER_PACK (parm1)
2754 == TEMPLATE_TYPE_PARAMETER_PACK (parm2)))
2756 else if (!same_type_p (TREE_TYPE (parm1), TREE_TYPE (parm2)))
2761 if ((p1 != NULL_TREE) != (p2 != NULL_TREE))
2762 /* One set of parameters has more parameters lists than the
2769 /* Determine whether PARM is a parameter pack. */
2772 template_parameter_pack_p (const_tree parm)
2774 /* Determine if we have a non-type template parameter pack. */
2775 if (TREE_CODE (parm) == PARM_DECL)
2776 return (DECL_TEMPLATE_PARM_P (parm)
2777 && TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)));
2778 if (TREE_CODE (parm) == TEMPLATE_PARM_INDEX)
2779 return TEMPLATE_PARM_PARAMETER_PACK (parm);
2781 /* If this is a list of template parameters, we could get a
2782 TYPE_DECL or a TEMPLATE_DECL. */
2783 if (TREE_CODE (parm) == TYPE_DECL || TREE_CODE (parm) == TEMPLATE_DECL)
2784 parm = TREE_TYPE (parm);
2786 /* Otherwise it must be a type template parameter. */
2787 return ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
2788 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM)
2789 && TEMPLATE_TYPE_PARAMETER_PACK (parm));
2792 /* Determine if T is a function parameter pack. */
2795 function_parameter_pack_p (const_tree t)
2797 if (t && TREE_CODE (t) == PARM_DECL)
2798 return FUNCTION_PARAMETER_PACK_P (t);
2802 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2803 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2806 get_function_template_decl (const_tree primary_func_tmpl_inst)
2808 if (! primary_func_tmpl_inst
2809 || TREE_CODE (primary_func_tmpl_inst) != FUNCTION_DECL
2810 || ! primary_template_instantiation_p (primary_func_tmpl_inst))
2813 return DECL_TEMPLATE_RESULT (DECL_TI_TEMPLATE (primary_func_tmpl_inst));
2816 /* Return true iff the function parameter PARAM_DECL was expanded
2817 from the function parameter pack PACK. */
2820 function_parameter_expanded_from_pack_p (tree param_decl, tree pack)
2822 if (DECL_ARTIFICIAL (param_decl)
2823 || !function_parameter_pack_p (pack))
2826 /* The parameter pack and its pack arguments have the same
2828 return DECL_PARM_INDEX (pack) == DECL_PARM_INDEX (param_decl);
2831 /* Determine whether ARGS describes a variadic template args list,
2832 i.e., one that is terminated by a template argument pack. */
2835 template_args_variadic_p (tree args)
2840 if (args == NULL_TREE)
2843 args = INNERMOST_TEMPLATE_ARGS (args);
2844 nargs = TREE_VEC_LENGTH (args);
2849 last_parm = TREE_VEC_ELT (args, nargs - 1);
2851 return ARGUMENT_PACK_P (last_parm);
2854 /* Generate a new name for the parameter pack name NAME (an
2855 IDENTIFIER_NODE) that incorporates its */
2858 make_ith_pack_parameter_name (tree name, int i)
2860 /* Munge the name to include the parameter index. */
2861 #define NUMBUF_LEN 128
2862 char numbuf[NUMBUF_LEN];
2866 snprintf (numbuf, NUMBUF_LEN, "%i", i);
2867 newname_len = IDENTIFIER_LENGTH (name)
2868 + strlen (numbuf) + 2;
2869 newname = (char*)alloca (newname_len);
2870 snprintf (newname, newname_len,
2871 "%s#%i", IDENTIFIER_POINTER (name), i);
2872 return get_identifier (newname);
2875 /* Return true if T is a primary function, class or alias template
2879 primary_template_instantiation_p (const_tree t)
2884 if (TREE_CODE (t) == FUNCTION_DECL)
2885 return DECL_LANG_SPECIFIC (t)
2886 && DECL_TEMPLATE_INSTANTIATION (t)
2887 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (t));
2888 else if (CLASS_TYPE_P (t) && !TYPE_DECL_ALIAS_P (TYPE_NAME (t)))
2889 return CLASSTYPE_TEMPLATE_INSTANTIATION (t)
2890 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (t));
2892 && TYPE_TEMPLATE_INFO (t)
2893 && PRIMARY_TEMPLATE_P (TYPE_TI_TEMPLATE (t))
2894 && DECL_TEMPLATE_INSTANTIATION (TYPE_NAME (t)))
2899 /* Return true if PARM is a template template parameter. */
2902 template_template_parameter_p (const_tree parm)
2904 return DECL_TEMPLATE_TEMPLATE_PARM_P (parm);
2907 /* Return the template parameters of T if T is a
2908 primary template instantiation, NULL otherwise. */
2911 get_primary_template_innermost_parameters (const_tree t)
2913 tree parms = NULL, template_info = NULL;
2915 if ((template_info = get_template_info (t))
2916 && primary_template_instantiation_p (t))
2917 parms = INNERMOST_TEMPLATE_PARMS
2918 (DECL_TEMPLATE_PARMS (TI_TEMPLATE (template_info)));
2923 /* Return the template parameters of the LEVELth level from the full list
2924 of template parameters PARMS. */
2927 get_template_parms_at_level (tree parms, int level)
2931 || TREE_CODE (parms) != TREE_LIST
2932 || level > TMPL_PARMS_DEPTH (parms))
2935 for (p = parms; p; p = TREE_CHAIN (p))
2936 if (TMPL_PARMS_DEPTH (p) == level)
2942 /* Returns the template arguments of T if T is a template instantiation,
2946 get_template_innermost_arguments (const_tree t)
2948 tree args = NULL, template_info = NULL;
2950 if ((template_info = get_template_info (t))
2951 && TI_ARGS (template_info))
2952 args = INNERMOST_TEMPLATE_ARGS (TI_ARGS (template_info));
2957 /* Return the argument pack elements of T if T is a template argument pack,
2961 get_template_argument_pack_elems (const_tree t)
2963 if (TREE_CODE (t) != TYPE_ARGUMENT_PACK
2964 && TREE_CODE (t) != NONTYPE_ARGUMENT_PACK)
2967 return ARGUMENT_PACK_ARGS (t);
2970 /* Structure used to track the progress of find_parameter_packs_r. */
2971 struct find_parameter_pack_data
2973 /* TREE_LIST that will contain all of the parameter packs found by
2975 tree* parameter_packs;
2977 /* Set of AST nodes that have been visited by the traversal. */
2978 struct pointer_set_t *visited;
2981 /* Identifies all of the argument packs that occur in a template
2982 argument and appends them to the TREE_LIST inside DATA, which is a
2983 find_parameter_pack_data structure. This is a subroutine of
2984 make_pack_expansion and uses_parameter_packs. */
2986 find_parameter_packs_r (tree *tp, int *walk_subtrees, void* data)
2989 struct find_parameter_pack_data* ppd =
2990 (struct find_parameter_pack_data*)data;
2991 bool parameter_pack_p = false;
2993 /* Handle type aliases/typedefs. */
2996 && TREE_CODE (TYPE_NAME (t)) == TYPE_DECL
2997 && TYPE_DECL_ALIAS_P (TYPE_NAME (t)))
2999 if (TYPE_TEMPLATE_INFO (t))
3000 cp_walk_tree (&TYPE_TI_ARGS (t),
3001 &find_parameter_packs_r,
3007 /* Identify whether this is a parameter pack or not. */
3008 switch (TREE_CODE (t))
3010 case TEMPLATE_PARM_INDEX:
3011 if (TEMPLATE_PARM_PARAMETER_PACK (t))
3012 parameter_pack_p = true;
3015 case TEMPLATE_TYPE_PARM:
3016 t = TYPE_MAIN_VARIANT (t);
3017 case TEMPLATE_TEMPLATE_PARM:
3018 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
3019 parameter_pack_p = true;
3023 if (FUNCTION_PARAMETER_PACK_P (t))
3025 /* We don't want to walk into the type of a PARM_DECL,
3026 because we don't want to see the type parameter pack. */
3028 parameter_pack_p = true;
3033 parameter_pack_p = true;
3036 /* Not a parameter pack. */
3040 if (parameter_pack_p)
3042 /* Add this parameter pack to the list. */
3043 *ppd->parameter_packs = tree_cons (NULL_TREE, t, *ppd->parameter_packs);
3047 cp_walk_tree (&TYPE_CONTEXT (t),
3048 &find_parameter_packs_r, ppd, ppd->visited);
3050 /* This switch statement will return immediately if we don't find a
3052 switch (TREE_CODE (t))
3054 case TEMPLATE_PARM_INDEX:
3057 case BOUND_TEMPLATE_TEMPLATE_PARM:
3058 /* Check the template itself. */
3059 cp_walk_tree (&TREE_TYPE (TYPE_TI_TEMPLATE (t)),
3060 &find_parameter_packs_r, ppd, ppd->visited);
3061 /* Check the template arguments. */
3062 cp_walk_tree (&TYPE_TI_ARGS (t), &find_parameter_packs_r, ppd,
3067 case TEMPLATE_TYPE_PARM:
3068 case TEMPLATE_TEMPLATE_PARM:
3075 if (TYPE_PTRMEMFUNC_P (t))
3081 if (TYPE_TEMPLATE_INFO (t))
3082 cp_walk_tree (&TI_ARGS (TYPE_TEMPLATE_INFO (t)),
3083 &find_parameter_packs_r, ppd, ppd->visited);
3090 cp_walk_tree (&TREE_TYPE (t),
3091 &find_parameter_packs_r, ppd, ppd->visited);
3095 cp_walk_tree (&TYPENAME_TYPE_FULLNAME (t), &find_parameter_packs_r,
3100 case TYPE_PACK_EXPANSION:
3101 case EXPR_PACK_EXPANSION:
3106 cp_walk_tree (&TYPE_MAX_VALUE (t), &find_parameter_packs_r,
3111 case IDENTIFIER_NODE:
3112 cp_walk_tree (&TREE_TYPE (t), &find_parameter_packs_r, ppd,
3124 /* Determines if the expression or type T uses any parameter packs. */
3126 uses_parameter_packs (tree t)
3128 tree parameter_packs = NULL_TREE;
3129 struct find_parameter_pack_data ppd;
3130 ppd.parameter_packs = ¶meter_packs;
3131 ppd.visited = pointer_set_create ();
3132 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
3133 pointer_set_destroy (ppd.visited);
3134 return parameter_packs != NULL_TREE;
3137 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3138 representation a base-class initializer into a parameter pack
3139 expansion. If all goes well, the resulting node will be an
3140 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3143 make_pack_expansion (tree arg)
3146 tree parameter_packs = NULL_TREE;
3147 bool for_types = false;
3148 struct find_parameter_pack_data ppd;
3150 if (!arg || arg == error_mark_node)
3153 if (TREE_CODE (arg) == TREE_LIST)
3155 /* The only time we will see a TREE_LIST here is for a base
3156 class initializer. In this case, the TREE_PURPOSE will be a
3157 _TYPE node (representing the base class expansion we're
3158 initializing) and the TREE_VALUE will be a TREE_LIST
3159 containing the initialization arguments.
3161 The resulting expansion looks somewhat different from most
3162 expansions. Rather than returning just one _EXPANSION, we
3163 return a TREE_LIST whose TREE_PURPOSE is a
3164 TYPE_PACK_EXPANSION containing the bases that will be
3165 initialized. The TREE_VALUE will be identical to the
3166 original TREE_VALUE, which is a list of arguments that will
3167 be passed to each base. We do not introduce any new pack
3168 expansion nodes into the TREE_VALUE (although it is possible
3169 that some already exist), because the TREE_PURPOSE and
3170 TREE_VALUE all need to be expanded together with the same
3171 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3172 resulting TREE_PURPOSE will mention the parameter packs in
3173 both the bases and the arguments to the bases. */
3176 tree parameter_packs = NULL_TREE;
3178 /* Determine which parameter packs will be used by the base
3180 ppd.visited = pointer_set_create ();
3181 ppd.parameter_packs = ¶meter_packs;
3182 cp_walk_tree (&TREE_PURPOSE (arg), &find_parameter_packs_r,
3185 if (parameter_packs == NULL_TREE)
3187 error ("base initializer expansion %<%T%> contains no parameter packs", arg);
3188 pointer_set_destroy (ppd.visited);
3189 return error_mark_node;
3192 if (TREE_VALUE (arg) != void_type_node)
3194 /* Collect the sets of parameter packs used in each of the
3195 initialization arguments. */
3196 for (value = TREE_VALUE (arg); value; value = TREE_CHAIN (value))
3198 /* Determine which parameter packs will be expanded in this
3200 cp_walk_tree (&TREE_VALUE (value), &find_parameter_packs_r,
3205 pointer_set_destroy (ppd.visited);
3207 /* Create the pack expansion type for the base type. */
3208 purpose = cxx_make_type (TYPE_PACK_EXPANSION);
3209 SET_PACK_EXPANSION_PATTERN (purpose, TREE_PURPOSE (arg));
3210 PACK_EXPANSION_PARAMETER_PACKS (purpose) = parameter_packs;
3212 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3213 they will rarely be compared to anything. */
3214 SET_TYPE_STRUCTURAL_EQUALITY (purpose);
3216 return tree_cons (purpose, TREE_VALUE (arg), NULL_TREE);
3219 if (TYPE_P (arg) || TREE_CODE (arg) == TEMPLATE_DECL)
3222 /* Build the PACK_EXPANSION_* node. */
3224 ? cxx_make_type (TYPE_PACK_EXPANSION)
3225 : make_node (EXPR_PACK_EXPANSION);
3226 SET_PACK_EXPANSION_PATTERN (result, arg);
3227 if (TREE_CODE (result) == EXPR_PACK_EXPANSION)
3229 /* Propagate type and const-expression information. */
3230 TREE_TYPE (result) = TREE_TYPE (arg);
3231 TREE_CONSTANT (result) = TREE_CONSTANT (arg);
3234 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3235 they will rarely be compared to anything. */
3236 SET_TYPE_STRUCTURAL_EQUALITY (result);
3238 /* Determine which parameter packs will be expanded. */
3239 ppd.parameter_packs = ¶meter_packs;
3240 ppd.visited = pointer_set_create ();
3241 cp_walk_tree (&arg, &find_parameter_packs_r, &ppd, ppd.visited);
3242 pointer_set_destroy (ppd.visited);
3244 /* Make sure we found some parameter packs. */
3245 if (parameter_packs == NULL_TREE)
3248 error ("expansion pattern %<%T%> contains no argument packs", arg);
3250 error ("expansion pattern %<%E%> contains no argument packs", arg);
3251 return error_mark_node;
3253 PACK_EXPANSION_PARAMETER_PACKS (result) = parameter_packs;
3255 PACK_EXPANSION_LOCAL_P (result) = at_function_scope_p ();
3260 /* Checks T for any "bare" parameter packs, which have not yet been
3261 expanded, and issues an error if any are found. This operation can
3262 only be done on full expressions or types (e.g., an expression
3263 statement, "if" condition, etc.), because we could have expressions like:
3265 foo(f(g(h(args)))...)
3267 where "args" is a parameter pack. check_for_bare_parameter_packs
3268 should not be called for the subexpressions args, h(args),
3269 g(h(args)), or f(g(h(args))), because we would produce erroneous
3272 Returns TRUE and emits an error if there were bare parameter packs,
3273 returns FALSE otherwise. */
3275 check_for_bare_parameter_packs (tree t)
3277 tree parameter_packs = NULL_TREE;
3278 struct find_parameter_pack_data ppd;
3280 if (!processing_template_decl || !t || t == error_mark_node)
3283 if (TREE_CODE (t) == TYPE_DECL)
3286 ppd.parameter_packs = ¶meter_packs;
3287 ppd.visited = pointer_set_create ();
3288 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
3289 pointer_set_destroy (ppd.visited);
3291 if (parameter_packs)
3293 error ("parameter packs not expanded with %<...%>:");
3294 while (parameter_packs)
3296 tree pack = TREE_VALUE (parameter_packs);
3297 tree name = NULL_TREE;
3299 if (TREE_CODE (pack) == TEMPLATE_TYPE_PARM
3300 || TREE_CODE (pack) == TEMPLATE_TEMPLATE_PARM)
3301 name = TYPE_NAME (pack);
3302 else if (TREE_CODE (pack) == TEMPLATE_PARM_INDEX)
3303 name = DECL_NAME (TEMPLATE_PARM_DECL (pack));
3305 name = DECL_NAME (pack);
3308 inform (input_location, " %qD", name);
3310 inform (input_location, " <anonymous>");
3312 parameter_packs = TREE_CHAIN (parameter_packs);
3321 /* Expand any parameter packs that occur in the template arguments in
3324 expand_template_argument_pack (tree args)
3326 tree result_args = NULL_TREE;
3327 int in_arg, out_arg = 0, nargs = args ? TREE_VEC_LENGTH (args) : 0;
3328 int num_result_args = -1;
3329 int non_default_args_count = -1;
3331 /* First, determine if we need to expand anything, and the number of
3332 slots we'll need. */
3333 for (in_arg = 0; in_arg < nargs; ++in_arg)
3335 tree arg = TREE_VEC_ELT (args, in_arg);
3336 if (arg == NULL_TREE)
3338 if (ARGUMENT_PACK_P (arg))
3340 int num_packed = TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg));
3341 if (num_result_args < 0)
3342 num_result_args = in_arg + num_packed;
3344 num_result_args += num_packed;
3348 if (num_result_args >= 0)
3353 /* If no expansion is necessary, we're done. */
3354 if (num_result_args < 0)
3357 /* Expand arguments. */
3358 result_args = make_tree_vec (num_result_args);
3359 if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (args))
3360 non_default_args_count =
3361 GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (args);
3362 for (in_arg = 0; in_arg < nargs; ++in_arg)
3364 tree arg = TREE_VEC_ELT (args, in_arg);
3365 if (ARGUMENT_PACK_P (arg))
3367 tree packed = ARGUMENT_PACK_ARGS (arg);
3368 int i, num_packed = TREE_VEC_LENGTH (packed);
3369 for (i = 0; i < num_packed; ++i, ++out_arg)
3370 TREE_VEC_ELT (result_args, out_arg) = TREE_VEC_ELT(packed, i);
3371 if (non_default_args_count > 0)
3372 non_default_args_count += num_packed;
3376 TREE_VEC_ELT (result_args, out_arg) = arg;
3380 if (non_default_args_count >= 0)
3381 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (result_args, non_default_args_count);
3385 /* Checks if DECL shadows a template parameter.
3387 [temp.local]: A template-parameter shall not be redeclared within its
3388 scope (including nested scopes).
3390 Emits an error and returns TRUE if the DECL shadows a parameter,
3391 returns FALSE otherwise. */
3394 check_template_shadow (tree decl)
3398 /* If we're not in a template, we can't possibly shadow a template
3400 if (!current_template_parms)
3403 /* Figure out what we're shadowing. */
3404 if (TREE_CODE (decl) == OVERLOAD)
3405 decl = OVL_CURRENT (decl);
3406 olddecl = innermost_non_namespace_value (DECL_NAME (decl));
3408 /* If there's no previous binding for this name, we're not shadowing
3409 anything, let alone a template parameter. */
3413 /* If we're not shadowing a template parameter, we're done. Note
3414 that OLDDECL might be an OVERLOAD (or perhaps even an
3415 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3417 if (!DECL_P (olddecl) || !DECL_TEMPLATE_PARM_P (olddecl))
3420 /* We check for decl != olddecl to avoid bogus errors for using a
3421 name inside a class. We check TPFI to avoid duplicate errors for
3422 inline member templates. */
3424 || TEMPLATE_PARMS_FOR_INLINE (current_template_parms))
3427 error ("declaration of %q+#D", decl);
3428 error (" shadows template parm %q+#D", olddecl);
3432 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3433 ORIG_LEVEL, DECL, and TYPE. NUM_SIBLINGS is the total number of
3434 template parameters. */
3437 build_template_parm_index (int index,
3444 tree t = make_node (TEMPLATE_PARM_INDEX);
3445 TEMPLATE_PARM_IDX (t) = index;
3446 TEMPLATE_PARM_LEVEL (t) = level;
3447 TEMPLATE_PARM_ORIG_LEVEL (t) = orig_level;
3448 TEMPLATE_PARM_NUM_SIBLINGS (t) = num_siblings;
3449 TEMPLATE_PARM_DECL (t) = decl;
3450 TREE_TYPE (t) = type;
3451 TREE_CONSTANT (t) = TREE_CONSTANT (decl);
3452 TREE_READONLY (t) = TREE_READONLY (decl);
3457 /* Find the canonical type parameter for the given template type
3458 parameter. Returns the canonical type parameter, which may be TYPE
3459 if no such parameter existed. */
3462 canonical_type_parameter (tree type)
3465 int idx = TEMPLATE_TYPE_IDX (type);
3466 if (!canonical_template_parms)
3467 canonical_template_parms = VEC_alloc (tree, gc, idx+1);
3469 while (VEC_length (tree, canonical_template_parms) <= (unsigned)idx)
3470 VEC_safe_push (tree, gc, canonical_template_parms, NULL_TREE);
3472 list = VEC_index (tree, canonical_template_parms, idx);
3473 while (list && !comptypes (type, TREE_VALUE (list), COMPARE_STRUCTURAL))
3474 list = TREE_CHAIN (list);
3477 return TREE_VALUE (list);
3480 VEC_replace(tree, canonical_template_parms, idx,
3481 tree_cons (NULL_TREE, type,
3482 VEC_index (tree, canonical_template_parms, idx)));
3487 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3488 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3489 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3490 new one is created. */
3493 reduce_template_parm_level (tree index, tree type, int levels, tree args,
3494 tsubst_flags_t complain)
3496 if (TEMPLATE_PARM_DESCENDANTS (index) == NULL_TREE
3497 || (TEMPLATE_PARM_LEVEL (TEMPLATE_PARM_DESCENDANTS (index))
3498 != TEMPLATE_PARM_LEVEL (index) - levels)
3499 || !same_type_p (type, TREE_TYPE (TEMPLATE_PARM_DESCENDANTS (index))))
3501 tree orig_decl = TEMPLATE_PARM_DECL (index);
3504 decl = build_decl (DECL_SOURCE_LOCATION (orig_decl),
3505 TREE_CODE (orig_decl), DECL_NAME (orig_decl), type);
3506 TREE_CONSTANT (decl) = TREE_CONSTANT (orig_decl);
3507 TREE_READONLY (decl) = TREE_READONLY (orig_decl);
3508 DECL_ARTIFICIAL (decl) = 1;
3509 SET_DECL_TEMPLATE_PARM_P (decl);
3511 t = build_template_parm_index (TEMPLATE_PARM_IDX (index),
3512 TEMPLATE_PARM_LEVEL (index) - levels,
3513 TEMPLATE_PARM_ORIG_LEVEL (index),
3514 TEMPLATE_PARM_NUM_SIBLINGS (index),
3516 TEMPLATE_PARM_DESCENDANTS (index) = t;
3517 TEMPLATE_PARM_PARAMETER_PACK (t)
3518 = TEMPLATE_PARM_PARAMETER_PACK (index);
3520 /* Template template parameters need this. */
3521 if (TREE_CODE (decl) == TEMPLATE_DECL)
3522 DECL_TEMPLATE_PARMS (decl) = tsubst_template_parms
3523 (DECL_TEMPLATE_PARMS (TEMPLATE_PARM_DECL (index)),
3527 return TEMPLATE_PARM_DESCENDANTS (index);
3530 /* Process information from new template parameter PARM and append it
3531 to the LIST being built. This new parameter is a non-type
3532 parameter iff IS_NON_TYPE is true. This new parameter is a
3533 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3534 is in PARM_LOC. NUM_TEMPLATE_PARMS is the size of the template
3535 parameter list PARM belongs to. This is used used to create a
3536 proper canonical type for the type of PARM that is to be created,
3537 iff PARM is a type. If the size is not known, this parameter shall
3541 process_template_parm (tree list, location_t parm_loc, tree parm,
3542 bool is_non_type, bool is_parameter_pack,
3543 unsigned num_template_parms)
3550 gcc_assert (TREE_CODE (parm) == TREE_LIST);
3551 defval = TREE_PURPOSE (parm);
3555 tree p = tree_last (list);
3557 if (p && TREE_VALUE (p) != error_mark_node)
3560 if (TREE_CODE (p) == TYPE_DECL || TREE_CODE (p) == TEMPLATE_DECL)
3561 idx = TEMPLATE_TYPE_IDX (TREE_TYPE (p));
3563 idx = TEMPLATE_PARM_IDX (DECL_INITIAL (p));
3573 parm = TREE_VALUE (parm);
3575 SET_DECL_TEMPLATE_PARM_P (parm);
3577 if (TREE_TYPE (parm) == error_mark_node)
3579 err_parm_list = build_tree_list (defval, parm);
3580 TREE_VALUE (err_parm_list) = error_mark_node;
3581 return chainon (list, err_parm_list);
3587 The top-level cv-qualifiers on the template-parameter are
3588 ignored when determining its type. */
3589 TREE_TYPE (parm) = TYPE_MAIN_VARIANT (TREE_TYPE (parm));
3590 if (invalid_nontype_parm_type_p (TREE_TYPE (parm), 1))
3592 err_parm_list = build_tree_list (defval, parm);
3593 TREE_VALUE (err_parm_list) = error_mark_node;
3594 return chainon (list, err_parm_list);
3597 if (uses_parameter_packs (TREE_TYPE (parm)) && !is_parameter_pack)
3599 /* This template parameter is not a parameter pack, but it
3600 should be. Complain about "bare" parameter packs. */
3601 check_for_bare_parameter_packs (TREE_TYPE (parm));
3603 /* Recover by calling this a parameter pack. */
3604 is_parameter_pack = true;
3608 /* A template parameter is not modifiable. */
3609 TREE_CONSTANT (parm) = 1;
3610 TREE_READONLY (parm) = 1;
3611 decl = build_decl (parm_loc,
3612 CONST_DECL, DECL_NAME (parm), TREE_TYPE (parm));
3613 TREE_CONSTANT (decl) = 1;
3614 TREE_READONLY (decl) = 1;
3615 DECL_INITIAL (parm) = DECL_INITIAL (decl)
3616 = build_template_parm_index (idx, processing_template_decl,
3617 processing_template_decl,
3619 decl, TREE_TYPE (parm));
3621 TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))
3622 = is_parameter_pack;
3627 parm = TREE_VALUE (TREE_VALUE (parm));
3629 if (parm && TREE_CODE (parm) == TEMPLATE_DECL)
3631 t = cxx_make_type (TEMPLATE_TEMPLATE_PARM);
3632 /* This is for distinguishing between real templates and template
3633 template parameters */
3634 TREE_TYPE (parm) = t;
3635 TREE_TYPE (DECL_TEMPLATE_RESULT (parm)) = t;
3640 t = cxx_make_type (TEMPLATE_TYPE_PARM);
3641 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3642 decl = build_decl (parm_loc,
3643 TYPE_DECL, parm, t);
3646 TYPE_NAME (t) = decl;
3647 TYPE_STUB_DECL (t) = decl;
3649 TEMPLATE_TYPE_PARM_INDEX (t)
3650 = build_template_parm_index (idx, processing_template_decl,
3651 processing_template_decl,
3653 decl, TREE_TYPE (parm));
3654 TEMPLATE_TYPE_PARAMETER_PACK (t) = is_parameter_pack;
3655 TYPE_CANONICAL (t) = canonical_type_parameter (t);
3657 DECL_ARTIFICIAL (decl) = 1;
3658 SET_DECL_TEMPLATE_PARM_P (decl);
3660 parm = build_tree_list (defval, parm);
3661 return chainon (list, parm);
3664 /* The end of a template parameter list has been reached. Process the
3665 tree list into a parameter vector, converting each parameter into a more
3666 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3670 end_template_parm_list (tree parms)
3674 tree saved_parmlist = make_tree_vec (list_length (parms));
3676 current_template_parms
3677 = tree_cons (size_int (processing_template_decl),
3678 saved_parmlist, current_template_parms);
3680 for (parm = parms, nparms = 0; parm; parm = next, nparms++)
3682 next = TREE_CHAIN (parm);
3683 TREE_VEC_ELT (saved_parmlist, nparms) = parm;
3684 TREE_CHAIN (parm) = NULL_TREE;
3687 --processing_template_parmlist;
3689 return saved_parmlist;
3692 /* Create a new type almost identical to TYPE but which has the
3693 following differences:
3695 1/ T has a new TEMPLATE_PARM_INDEX that carries the new number of
3696 template sibling parameters of T.
3698 2/ T has a new canonical type that matches the new number
3701 3/ From now on, T is going to be what lookups referring to the
3702 name of TYPE will return. No lookup should return TYPE anymore.
3704 NUM_PARMS is the new number of sibling parms TYPE belongs to.
3706 This is a subroutine of fixup_template_parms. */
3709 fixup_template_type_parm_type (tree type, int num_parms)
3711 tree orig_idx = TEMPLATE_TYPE_PARM_INDEX (type), idx;
3713 /* This is the decl which name is inserted into the symbol table for
3714 the template parm type. So whenever we lookup the type name, this
3715 is the DECL we get. */
3718 /* Do not fix up the type twice. */
3719 if (orig_idx && TEMPLATE_PARM_NUM_SIBLINGS (orig_idx) != 0)
3722 t = copy_type (type);
3723 decl = TYPE_NAME (t);
3725 TYPE_MAIN_VARIANT (t) = t;
3726 TYPE_NEXT_VARIANT (t)= NULL_TREE;
3727 TYPE_POINTER_TO (t) = 0;
3728 TYPE_REFERENCE_TO (t) = 0;
3730 idx = build_template_parm_index (TEMPLATE_PARM_IDX (orig_idx),
3731 TEMPLATE_PARM_LEVEL (orig_idx),
3732 TEMPLATE_PARM_ORIG_LEVEL (orig_idx),
3735 TEMPLATE_PARM_DESCENDANTS (idx) = TEMPLATE_PARM_DESCENDANTS (orig_idx);
3736 TEMPLATE_PARM_PARAMETER_PACK (idx) = TEMPLATE_PARM_PARAMETER_PACK (orig_idx);
3737 TEMPLATE_TYPE_PARM_INDEX (t) = idx;
3739 TYPE_STUB_DECL (t) = decl;
3740 TEMPLATE_TYPE_DECL (t) = decl;
3741 if (TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM)
3742 TREE_TYPE (DECL_TEMPLATE_RESULT (decl)) = t;
3744 /* Update the type associated to the type name stored in the symbol
3745 table. Now, whenever the type name is looked up, the resulting
3746 type is properly fixed up. */
3747 TREE_TYPE (decl) = t;
3749 TYPE_CANONICAL (t) = canonical_type_parameter (t);
3754 /* Create and return a new TEMPLATE_PARM_INDEX that is almost
3755 identical to I, but that is fixed up as to:
3757 1/ carry the number of sibling parms (NUM_PARMS) of the template
3758 parm represented by I.
3760 2/ replace all references to template parm types declared before I
3761 (in the same template parm list as I) by references to template
3762 parm types contained in ARGS. ARGS should contain the list of
3763 template parms that have been fixed up so far, in a form suitable
3764 to be passed to tsubst.
3766 This is a subroutine of fixup_template_parms. */
3769 fixup_template_parm_index (tree i, tree args, int num_parms)
3771 tree index, decl, type;
3774 || TREE_CODE (i) != TEMPLATE_PARM_INDEX
3775 /* Do not fix up the index twice. */
3776 || (TEMPLATE_PARM_NUM_SIBLINGS (i) != 0))
3779 decl = TEMPLATE_PARM_DECL (i);
3780 type = TREE_TYPE (decl);
3782 index = build_template_parm_index (TEMPLATE_PARM_IDX (i),
3783 TEMPLATE_PARM_LEVEL (i),
3784 TEMPLATE_PARM_ORIG_LEVEL (i),
3788 TEMPLATE_PARM_DESCENDANTS (index) = TEMPLATE_PARM_DESCENDANTS (i);
3789 TEMPLATE_PARM_PARAMETER_PACK (index) = TEMPLATE_PARM_PARAMETER_PACK (i);
3791 type = tsubst (type, args, tf_none, NULL_TREE);
3793 TREE_TYPE (decl) = type;
3794 TREE_TYPE (index) = type;
3800 This is a subroutine of fixup_template_parms.
3802 It computes the canonical type of the type of the template
3803 parameter PARM_DESC and update all references to that type so that
3804 they use the newly computed canonical type. No access check is
3805 performed during the fixup. PARM_DESC is a TREE_LIST which
3806 TREE_VALUE is the template parameter and its TREE_PURPOSE is the
3807 default argument of the template parm if any. IDX is the index of
3808 the template parameter, starting at 0. NUM_PARMS is the number of
3809 template parameters in the set PARM_DESC belongs to. ARGLIST is a
3810 TREE_VEC containing the full set of template parameters in a form
3811 suitable to be passed to substs functions as their ARGS
3812 argument. This is what current_template_args returns for a given
3813 template. The innermost vector of args in ARGLIST is the set of
3814 template parms that have been fixed up so far. This function adds
3815 the fixed up parameter into that vector. */
3818 fixup_template_parm (tree parm_desc,
3823 tree parm = TREE_VALUE (parm_desc);
3824 tree fixedup_args = INNERMOST_TEMPLATE_ARGS (arglist);
3826 push_deferring_access_checks (dk_no_check);
3828 if (TREE_CODE (parm) == TYPE_DECL)
3830 /* PARM is a template type parameter. Fix up its type, add
3831 the fixed-up template parm to the vector of fixed-up
3832 template parms so far, and substitute the fixed-up
3833 template parms into the default argument of this
3836 fixup_template_type_parm_type (TREE_TYPE (parm), num_parms);
3837 TREE_TYPE (parm) = t;
3839 TREE_VEC_ELT (fixedup_args, idx) = template_parm_to_arg (parm_desc);
3841 else if (TREE_CODE (parm) == TEMPLATE_DECL)
3843 /* PARM is a template template parameter. This is going to
3845 tree tparms, targs, innermost_args, t;
3848 /* First, fix up the parms of the template template parm
3849 because the parms are involved in defining the new canonical
3850 type of the template template parm. */
3852 /* So we need to substitute the template parm types that have
3853 been fixed up so far into the template parms of this template
3854 template parm. E.g, consider this:
3856 template<class T, template<T u> class TT> class S;
3858 In this case we want to substitute T into the
3859 template parameters of TT.
3861 So let's walk the template parms of PARM here, and
3862 tsubst ARGLIST into into each of the template
3865 /* For this substitution we need to build the full set of
3866 template parameters and use that as arguments for the
3867 tsubsting function. */
3868 tparms = INNERMOST_TEMPLATE_PARMS (DECL_TEMPLATE_PARMS (parm));
3870 /* This will contain the innermost parms of PARM into which
3871 we have substituted so far. */
3872 innermost_args = make_tree_vec (TREE_VEC_LENGTH (tparms));
3873 targs = add_to_template_args (arglist, innermost_args);
3874 for (j = 0; j < TREE_VEC_LENGTH (tparms); ++j)
3878 parameter = TREE_VEC_ELT (tparms, j);
3880 /* INNERMOST_ARGS needs to have at least the same number
3881 of elements as the index PARAMETER, ortherwise
3882 tsubsting into PARAMETER will result in partially
3883 instantiating it, reducing its tempate parm
3884 level. Let's tactically fill INNERMOST_ARGS for that
3886 TREE_VEC_ELT (innermost_args, j) =
3887 template_parm_to_arg (parameter);
3889 fixup_template_parm (parameter, j,
3890 TREE_VEC_LENGTH (tparms),
3894 /* Now fix up the type of the template template parm. */
3896 t = fixup_template_type_parm_type (TREE_TYPE (parm), num_parms);
3897 TREE_TYPE (parm) = t;
3899 TREE_VEC_ELT (fixedup_args, idx) =
3900 template_parm_to_arg (parm_desc);
3902 else if (TREE_CODE (parm) == PARM_DECL)
3904 /* PARM is a non-type template parameter. We need to:
3906 * Fix up its TEMPLATE_PARM_INDEX to make it carry the
3907 proper number of sibling parameters.
3909 * Make lookups of the template parameter return a reference
3910 to the fixed-up index. No lookup should return references
3911 to the former index anymore.
3913 * Substitute the template parms that got fixed up so far
3915 * into the type of PARM. */
3917 tree index = DECL_INITIAL (parm);
3919 /* PUSHED_DECL is the decl added to the symbol table with
3920 the name of the parameter. E,g:
3922 template<class T, T u> //#0
3923 auto my_function(T t) -> decltype(u); //#1
3925 Here, when looking up u at //#1, we get the decl of u
3926 resulting from the declaration in #0. This is what
3927 PUSHED_DECL is. We need to replace the reference to the
3928 old TEMPLATE_PARM_INDEX carried by PUSHED_DECL by the
3929 fixed-up TEMPLATE_PARM_INDEX. */
3930 tree pushed_decl = TEMPLATE_PARM_DECL (index);
3932 /* Let's fix up the TEMPLATE_PARM_INDEX then. Note that we must
3933 fixup the type of PUSHED_DECL as well and luckily
3934 fixup_template_parm_index does it for us too. */
3935 tree fixed_up_index =
3936 fixup_template_parm_index (index, arglist, num_parms);
3938 DECL_INITIAL (pushed_decl) = DECL_INITIAL (parm) = fixed_up_index;
3940 /* Add this fixed up PARM to the template parms we've fixed
3941 up so far and use that to substitute the fixed-up
3942 template parms into the type of PARM. */
3943 TREE_VEC_ELT (fixedup_args, idx) =
3944 template_parm_to_arg (parm_desc);
3945 TREE_TYPE (parm) = tsubst (TREE_TYPE (parm), arglist,
3946 tf_none, NULL_TREE);
3949 TREE_PURPOSE (parm_desc) =
3950 tsubst_template_arg (TREE_PURPOSE (parm_desc),
3951 arglist, tf_none, parm);
3953 pop_deferring_access_checks ();
3956 /* Walk the current template parms and properly compute the canonical
3957 types of the dependent types created during
3958 cp_parser_template_parameter_list. */
3961 fixup_template_parms (void)
3968 parameter_vec = INNERMOST_TEMPLATE_PARMS (current_template_parms);
3969 if (parameter_vec == NULL_TREE)
3972 num_parms = TREE_VEC_LENGTH (parameter_vec);
3974 /* This vector contains the current innermost template parms that
3975 have been fixed up so far. The form of FIXEDUP_ARGS is suitable
3976 to be passed to tsubst* functions as their ARGS argument. */
3977 fixedup_args = make_tree_vec (num_parms);
3979 /* This vector contains the full set of template parms in a form
3980 suitable to be passed to substs functions as their ARGS
3982 arglist = current_template_args ();
3983 arglist = add_outermost_template_args (arglist, fixedup_args);
3985 /* Let's do the proper fixup now. */
3986 for (i = 0; i < num_parms; ++i)
3987 fixup_template_parm (TREE_VEC_ELT (parameter_vec, i),
3988 i, num_parms, arglist);
3991 /* end_template_decl is called after a template declaration is seen. */
3994 end_template_decl (void)
3996 reset_specialization ();
3998 if (! processing_template_decl)
4001 /* This matches the pushlevel in begin_template_parm_list. */
4004 --processing_template_decl;
4005 current_template_parms = TREE_CHAIN (current_template_parms);
4008 /* Takes a TREE_LIST representing a template parameter and convert it
4009 into an argument suitable to be passed to the type substitution
4010 functions. Note that If the TREE_LIST contains an error_mark
4011 node, the returned argument is error_mark_node. */
4014 template_parm_to_arg (tree t)
4018 || TREE_CODE (t) != TREE_LIST)
4021 if (error_operand_p (TREE_VALUE (t)))
4022 return error_mark_node;
4026 if (TREE_CODE (t) == TYPE_DECL
4027 || TREE_CODE (t) == TEMPLATE_DECL)
4031 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
4033 /* Turn this argument into a TYPE_ARGUMENT_PACK
4034 with a single element, which expands T. */
4035 tree vec = make_tree_vec (1);
4036 #ifdef ENABLE_CHECKING
4037 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
4038 (vec, TREE_VEC_LENGTH (vec));
4040 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
4042 t = cxx_make_type (TYPE_ARGUMENT_PACK);
4043 SET_ARGUMENT_PACK_ARGS (t, vec);
4048 t = DECL_INITIAL (t);
4050 if (TEMPLATE_PARM_PARAMETER_PACK (t))
4052 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
4053 with a single element, which expands T. */
4054 tree vec = make_tree_vec (1);
4055 tree type = TREE_TYPE (TEMPLATE_PARM_DECL (t));
4056 #ifdef ENABLE_CHECKING
4057 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
4058 (vec, TREE_VEC_LENGTH (vec));
4060 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
4062 t = make_node (NONTYPE_ARGUMENT_PACK);
4063 SET_ARGUMENT_PACK_ARGS (t, vec);
4064 TREE_TYPE (t) = type;
4070 /* This function returns TRUE if PARM_PACK is a template parameter
4071 pack and if ARG_PACK is what template_parm_to_arg returned when
4072 passed PARM_PACK. */
4075 arg_from_parm_pack_p (tree arg_pack, tree parm_pack)
4077 /* For clarity in the comments below let's use the representation
4078 argument_pack<elements>' to denote an argument pack and its
4081 In the 'if' block below, we want to detect cases where
4082 ARG_PACK is argument_pack<PARM_PACK...>. I.e, we want to
4083 check if ARG_PACK is an argument pack which sole element is
4084 the expansion of PARM_PACK. That argument pack is typically
4085 created by template_parm_to_arg when passed a parameter
4089 && TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack)) == 1
4090 && PACK_EXPANSION_P (TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0)))
4092 tree expansion = TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0);
4093 tree pattern = PACK_EXPANSION_PATTERN (expansion);
4094 /* So we have an argument_pack<P...>. We want to test if P
4095 is actually PARM_PACK. We will not use cp_tree_equal to
4096 test P and PARM_PACK because during type fixup (by
4097 fixup_template_parm) P can be a pre-fixup version of a
4098 type and PARM_PACK be its post-fixup version.
4099 cp_tree_equal would consider them as different even
4100 though we would want to consider them compatible for our
4101 precise purpose here.
4103 Thus we are going to consider that P and PARM_PACK are
4104 compatible if they have the same DECL. */
4105 if ((/* If ARG_PACK is a type parameter pack named by the
4106 same DECL as parm_pack ... */
4108 && TYPE_P (parm_pack)
4109 && TYPE_NAME (pattern) == TYPE_NAME (parm_pack))
4110 /* ... or if PARM_PACK is a non-type parameter named by the
4111 same DECL as ARG_PACK. Note that PARM_PACK being a
4112 non-type parameter means it's either a PARM_DECL or a
4113 TEMPLATE_PARM_INDEX. */
4114 || (TREE_CODE (pattern) == TEMPLATE_PARM_INDEX
4115 && ((TREE_CODE (parm_pack) == PARM_DECL
4116 && (TEMPLATE_PARM_DECL (pattern)
4117 == TEMPLATE_PARM_DECL (DECL_INITIAL (parm_pack))))
4118 || (TREE_CODE (parm_pack) == TEMPLATE_PARM_INDEX
4119 && (TEMPLATE_PARM_DECL (pattern)
4120 == TEMPLATE_PARM_DECL (parm_pack))))))
4121 && template_parameter_pack_p (pattern))
4127 /* Within the declaration of a template, return all levels of template
4128 parameters that apply. The template parameters are represented as
4129 a TREE_VEC, in the form documented in cp-tree.h for template
4133 current_template_args (void)
4136 tree args = NULL_TREE;
4137 int length = TMPL_PARMS_DEPTH (current_template_parms);
4140 /* If there is only one level of template parameters, we do not
4141 create a TREE_VEC of TREE_VECs. Instead, we return a single
4142 TREE_VEC containing the arguments. */
4144 args = make_tree_vec (length);
4146 for (header = current_template_parms; header; header = TREE_CHAIN (header))
4148 tree a = copy_node (TREE_VALUE (header));
4151 TREE_TYPE (a) = NULL_TREE;
4152 for (i = TREE_VEC_LENGTH (a) - 1; i >= 0; --i)
4153 TREE_VEC_ELT (a, i) = template_parm_to_arg (TREE_VEC_ELT (a, i));
4155 #ifdef ENABLE_CHECKING
4156 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (a, TREE_VEC_LENGTH (a));
4160 TREE_VEC_ELT (args, --l) = a;
4165 if (length > 1 && TREE_VEC_ELT (args, 0) == NULL_TREE)
4166 /* This can happen for template parms of a template template
4169 template<template<class T, class U> class TT> struct S;
4171 Consider the level of the parms of TT; T and U both have
4172 level 2; TT has no template parm of level 1. So in this case
4173 the first element of full_template_args is NULL_TREE. If we
4174 leave it like this TMPL_ARG_DEPTH on args returns 1 instead
4175 of 2. This will make tsubst wrongly consider that T and U
4176 have level 1. Instead, let's create a dummy vector as the
4177 first element of full_template_args so that TMPL_ARG_DEPTH
4178 returns the correct depth for args. */
4179 TREE_VEC_ELT (args, 0) = make_tree_vec (1);
4183 /* Update the declared TYPE by doing any lookups which were thought to be
4184 dependent, but are not now that we know the SCOPE of the declarator. */
4187 maybe_update_decl_type (tree orig_type, tree scope)
4189 tree type = orig_type;
4191 if (type == NULL_TREE)
4194 if (TREE_CODE (orig_type) == TYPE_DECL)
4195 type = TREE_TYPE (type);
4197 if (scope && TYPE_P (scope) && dependent_type_p (scope)
4198 && dependent_type_p (type)
4199 /* Don't bother building up the args in this case. */
4200 && TREE_CODE (type) != TEMPLATE_TYPE_PARM)
4202 /* tsubst in the args corresponding to the template parameters,
4203 including auto if present. Most things will be unchanged, but
4204 make_typename_type and tsubst_qualified_id will resolve
4205 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4206 tree args = current_template_args ();
4207 tree auto_node = type_uses_auto (type);
4211 tree auto_vec = make_tree_vec (1);
4212 TREE_VEC_ELT (auto_vec, 0) = auto_node;
4213 args = add_to_template_args (args, auto_vec);
4215 pushed = push_scope (scope);
4216 type = tsubst (type, args, tf_warning_or_error, NULL_TREE);
4221 if (type == error_mark_node)
4224 if (TREE_CODE (orig_type) == TYPE_DECL)
4226 if (same_type_p (type, TREE_TYPE (orig_type)))
4229 type = TYPE_NAME (type);
4234 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4235 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
4236 a member template. Used by push_template_decl below. */
4239 build_template_decl (tree decl, tree parms, bool member_template_p)
4241 tree tmpl = build_lang_decl (TEMPLATE_DECL, DECL_NAME (decl), NULL_TREE);
4242 DECL_TEMPLATE_PARMS (tmpl) = parms;
4243 DECL_CONTEXT (tmpl) = DECL_CONTEXT (decl);
4244 DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl);
4245 DECL_MEMBER_TEMPLATE_P (tmpl) = member_template_p;
4250 struct template_parm_data
4252 /* The level of the template parameters we are currently
4256 /* The index of the specialization argument we are currently
4260 /* An array whose size is the number of template parameters. The
4261 elements are nonzero if the parameter has been used in any one
4262 of the arguments processed so far. */
4265 /* An array whose size is the number of template arguments. The
4266 elements are nonzero if the argument makes use of template
4267 parameters of this level. */
4268 int* arg_uses_template_parms;
4271 /* Subroutine of push_template_decl used to see if each template
4272 parameter in a partial specialization is used in the explicit
4273 argument list. If T is of the LEVEL given in DATA (which is
4274 treated as a template_parm_data*), then DATA->PARMS is marked
4278 mark_template_parm (tree t, void* data)
4282 struct template_parm_data* tpd = (struct template_parm_data*) data;
4284 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
4286 level = TEMPLATE_PARM_LEVEL (t);
4287 idx = TEMPLATE_PARM_IDX (t);
4291 level = TEMPLATE_TYPE_LEVEL (t);
4292 idx = TEMPLATE_TYPE_IDX (t);
4295 if (level == tpd->level)
4297 tpd->parms[idx] = 1;
4298 tpd->arg_uses_template_parms[tpd->current_arg] = 1;
4301 /* Return zero so that for_each_template_parm will continue the
4302 traversal of the tree; we want to mark *every* template parm. */
4306 /* Process the partial specialization DECL. */
4309 process_partial_specialization (tree decl)
4311 tree type = TREE_TYPE (decl);
4312 tree maintmpl = CLASSTYPE_TI_TEMPLATE (type);
4313 tree specargs = CLASSTYPE_TI_ARGS (type);
4314 tree inner_args = INNERMOST_TEMPLATE_ARGS (specargs);
4315 tree main_inner_parms = DECL_INNERMOST_TEMPLATE_PARMS (maintmpl);
4318 int nargs = TREE_VEC_LENGTH (inner_args);
4321 bool did_error_intro = false;
4322 struct template_parm_data tpd;
4323 struct template_parm_data tpd2;
4325 gcc_assert (current_template_parms);
4327 inner_parms = INNERMOST_TEMPLATE_PARMS (current_template_parms);
4328 ntparms = TREE_VEC_LENGTH (inner_parms);
4330 /* We check that each of the template parameters given in the
4331 partial specialization is used in the argument list to the
4332 specialization. For example:
4334 template <class T> struct S;
4335 template <class T> struct S<T*>;
4337 The second declaration is OK because `T*' uses the template
4338 parameter T, whereas
4340 template <class T> struct S<int>;
4342 is no good. Even trickier is:
4353 The S2<T> declaration is actually invalid; it is a
4354 full-specialization. Of course,
4357 struct S2<T (*)(U)>;
4359 or some such would have been OK. */
4360 tpd.level = TMPL_PARMS_DEPTH (current_template_parms);
4361 tpd.parms = XALLOCAVEC (int, ntparms);
4362 memset (tpd.parms, 0, sizeof (int) * ntparms);
4364 tpd.arg_uses_template_parms = XALLOCAVEC (int, nargs);
4365 memset (tpd.arg_uses_template_parms, 0, sizeof (int) * nargs);
4366 for (i = 0; i < nargs; ++i)
4368 tpd.current_arg = i;
4369 for_each_template_parm (TREE_VEC_ELT (inner_args, i),
4370 &mark_template_parm,
4373 /*include_nondeduced_p=*/false);
4375 for (i = 0; i < ntparms; ++i)
4376 if (tpd.parms[i] == 0)
4378 /* One of the template parms was not used in the
4380 if (!did_error_intro)
4382 error ("template parameters not used in partial specialization:");
4383 did_error_intro = true;
4386 error (" %qD", TREE_VALUE (TREE_VEC_ELT (inner_parms, i)));
4389 if (did_error_intro)
4390 return error_mark_node;
4392 /* [temp.class.spec]
4394 The argument list of the specialization shall not be identical to
4395 the implicit argument list of the primary template. */
4396 if (comp_template_args
4398 INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE
4400 error ("partial specialization %qT does not specialize any template arguments", type);
4402 /* [temp.class.spec]
4404 A partially specialized non-type argument expression shall not
4405 involve template parameters of the partial specialization except
4406 when the argument expression is a simple identifier.
4408 The type of a template parameter corresponding to a specialized
4409 non-type argument shall not be dependent on a parameter of the
4412 Also, we verify that pack expansions only occur at the
4413 end of the argument list. */
4414 gcc_assert (nargs == DECL_NTPARMS (maintmpl));
4416 for (i = 0; i < nargs; ++i)
4418 tree parm = TREE_VALUE (TREE_VEC_ELT (main_inner_parms, i));
4419 tree arg = TREE_VEC_ELT (inner_args, i);
4420 tree packed_args = NULL_TREE;
4423 if (ARGUMENT_PACK_P (arg))
4425 /* Extract the arguments from the argument pack. We'll be
4426 iterating over these in the following loop. */
4427 packed_args = ARGUMENT_PACK_ARGS (arg);
4428 len = TREE_VEC_LENGTH (packed_args);
4431 for (j = 0; j < len; j++)
4434 /* Get the Jth argument in the parameter pack. */
4435 arg = TREE_VEC_ELT (packed_args, j);
4437 if (PACK_EXPANSION_P (arg))
4439 /* Pack expansions must come at the end of the
4441 if ((packed_args && j < len - 1)
4442 || (!packed_args && i < nargs - 1))
4444 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
4445 error ("parameter pack argument %qE must be at the "
4446 "end of the template argument list", arg);
4448 error ("parameter pack argument %qT must be at the "
4449 "end of the template argument list", arg);
4453 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
4454 /* We only care about the pattern. */
4455 arg = PACK_EXPANSION_PATTERN (arg);
4457 if (/* These first two lines are the `non-type' bit. */
4459 && TREE_CODE (arg) != TEMPLATE_DECL
4460 /* This next line is the `argument expression is not just a
4461 simple identifier' condition and also the `specialized
4462 non-type argument' bit. */
4463 && TREE_CODE (arg) != TEMPLATE_PARM_INDEX)
4465 if ((!packed_args && tpd.arg_uses_template_parms[i])
4466 || (packed_args && uses_template_parms (arg)))
4467 error ("template argument %qE involves template parameter(s)",
4471 /* Look at the corresponding template parameter,
4472 marking which template parameters its type depends
4474 tree type = TREE_TYPE (parm);
4478 /* We haven't yet initialized TPD2. Do so now. */
4479 tpd2.arg_uses_template_parms = XALLOCAVEC (int, nargs);
4480 /* The number of parameters here is the number in the
4481 main template, which, as checked in the assertion
4483 tpd2.parms = XALLOCAVEC (int, nargs);
4485 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (maintmpl));
4488 /* Mark the template parameters. But this time, we're
4489 looking for the template parameters of the main
4490 template, not in the specialization. */
4491 tpd2.current_arg = i;
4492 tpd2.arg_uses_template_parms[i] = 0;
4493 memset (tpd2.parms, 0, sizeof (int) * nargs);
4494 for_each_template_parm (type,
4495 &mark_template_parm,
4498 /*include_nondeduced_p=*/false);
4500 if (tpd2.arg_uses_template_parms [i])
4502 /* The type depended on some template parameters.
4503 If they are fully specialized in the
4504 specialization, that's OK. */
4507 for (j = 0; j < nargs; ++j)
4508 if (tpd2.parms[j] != 0
4509 && tpd.arg_uses_template_parms [j])
4512 error_n (input_location, count,
4513 "type %qT of template argument %qE depends "
4514 "on a template parameter",
4515 "type %qT of template argument %qE depends "
4516 "on template parameters",
4525 /* We should only get here once. */
4526 gcc_assert (!COMPLETE_TYPE_P (type));
4528 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)
4529 = tree_cons (specargs, inner_parms,
4530 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl));
4531 TREE_TYPE (DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)) = type;
4533 for (inst = DECL_TEMPLATE_INSTANTIATIONS (maintmpl); inst;
4534 inst = TREE_CHAIN (inst))
4536 tree inst_type = TREE_VALUE (inst);
4537 if (COMPLETE_TYPE_P (inst_type)
4538 && CLASSTYPE_IMPLICIT_INSTANTIATION (inst_type))
4540 tree spec = most_specialized_class (inst_type, maintmpl, tf_none);
4541 if (spec && TREE_TYPE (spec) == type)
4542 permerror (input_location,
4543 "partial specialization of %qT after instantiation "
4544 "of %qT", type, inst_type);
4551 /* Check that a template declaration's use of default arguments and
4552 parameter packs is not invalid. Here, PARMS are the template
4553 parameters. IS_PRIMARY is nonzero if DECL is the thing declared by
4554 a primary template. IS_PARTIAL is nonzero if DECL is a partial
4558 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4559 declaration (but not a definition); 1 indicates a declaration, 2
4560 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4561 emitted for extraneous default arguments.
4563 Returns TRUE if there were no errors found, FALSE otherwise. */
4566 check_default_tmpl_args (tree decl, tree parms, int is_primary,
4567 int is_partial, int is_friend_decl)
4570 int last_level_to_check;
4572 bool no_errors = true;
4576 A default template-argument shall not be specified in a
4577 function template declaration or a function template definition, nor
4578 in the template-parameter-list of the definition of a member of a
4581 if (TREE_CODE (CP_DECL_CONTEXT (decl)) == FUNCTION_DECL)
4582 /* You can't have a function template declaration in a local
4583 scope, nor you can you define a member of a class template in a
4587 if (current_class_type
4588 && !TYPE_BEING_DEFINED (current_class_type)
4589 && DECL_LANG_SPECIFIC (decl)
4590 && DECL_DECLARES_FUNCTION_P (decl)
4591 /* If this is either a friend defined in the scope of the class
4592 or a member function. */
4593 && (DECL_FUNCTION_MEMBER_P (decl)
4594 ? same_type_p (DECL_CONTEXT (decl), current_class_type)
4595 : DECL_FRIEND_CONTEXT (decl)
4596 ? same_type_p (DECL_FRIEND_CONTEXT (decl), current_class_type)
4598 /* And, if it was a member function, it really was defined in
4599 the scope of the class. */
4600 && (!DECL_FUNCTION_MEMBER_P (decl)
4601 || DECL_INITIALIZED_IN_CLASS_P (decl)))
4602 /* We already checked these parameters when the template was
4603 declared, so there's no need to do it again now. This function
4604 was defined in class scope, but we're processing it's body now
4605 that the class is complete. */
4608 /* Core issue 226 (C++0x only): the following only applies to class
4610 if ((cxx_dialect == cxx98) || TREE_CODE (decl) != FUNCTION_DECL)
4614 If a template-parameter has a default template-argument, all
4615 subsequent template-parameters shall have a default
4616 template-argument supplied. */
4617 for (parm_level = parms; parm_level; parm_level = TREE_CHAIN (parm_level))
4619 tree inner_parms = TREE_VALUE (parm_level);
4620 int ntparms = TREE_VEC_LENGTH (inner_parms);
4621 int seen_def_arg_p = 0;
4624 for (i = 0; i < ntparms; ++i)
4626 tree parm = TREE_VEC_ELT (inner_parms, i);
4628 if (parm == error_mark_node)
4631 if (TREE_PURPOSE (parm))
4633 else if (seen_def_arg_p
4634 && !template_parameter_pack_p (TREE_VALUE (parm)))
4636 error ("no default argument for %qD", TREE_VALUE (parm));
4637 /* For better subsequent error-recovery, we indicate that
4638 there should have been a default argument. */
4639 TREE_PURPOSE (parm) = error_mark_node;
4645 /* Don't complain about an enclosing partial
4647 && parm_level == parms
4648 && TREE_CODE (decl) == TYPE_DECL
4650 && template_parameter_pack_p (TREE_VALUE (parm)))
4652 /* A primary class template can only have one
4653 parameter pack, at the end of the template
4656 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL)
4657 error ("parameter pack %qE must be at the end of the"
4658 " template parameter list", TREE_VALUE (parm));
4660 error ("parameter pack %qT must be at the end of the"
4661 " template parameter list",
4662 TREE_TYPE (TREE_VALUE (parm)));
4664 TREE_VALUE (TREE_VEC_ELT (inner_parms, i))
4672 if (((cxx_dialect == cxx98) && TREE_CODE (decl) != TYPE_DECL)
4676 /* For an ordinary class template, default template arguments are
4677 allowed at the innermost level, e.g.:
4678 template <class T = int>
4680 but, in a partial specialization, they're not allowed even
4681 there, as we have in [temp.class.spec]:
4683 The template parameter list of a specialization shall not
4684 contain default template argument values.
4686 So, for a partial specialization, or for a function template
4687 (in C++98/C++03), we look at all of them. */
4690 /* But, for a primary class template that is not a partial
4691 specialization we look at all template parameters except the
4693 parms = TREE_CHAIN (parms);
4695 /* Figure out what error message to issue. */
4696 if (is_friend_decl == 2)
4697 msg = G_("default template arguments may not be used in function template "
4698 "friend re-declaration");
4699 else if (is_friend_decl)
4700 msg = G_("default template arguments may not be used in function template "
4701 "friend declarations");
4702 else if (TREE_CODE (decl) == FUNCTION_DECL && (cxx_dialect == cxx98))
4703 msg = G_("default template arguments may not be used in function templates "
4704 "without -std=c++11 or -std=gnu++11");
4705 else if (is_partial)
4706 msg = G_("default template arguments may not be used in "
4707 "partial specializations");
4709 msg = G_("default argument for template parameter for class enclosing %qD");
4711 if (current_class_type && TYPE_BEING_DEFINED (current_class_type))
4712 /* If we're inside a class definition, there's no need to
4713 examine the parameters to the class itself. On the one
4714 hand, they will be checked when the class is defined, and,
4715 on the other, default arguments are valid in things like:
4716 template <class T = double>
4717 struct S { template <class U> void f(U); };
4718 Here the default argument for `S' has no bearing on the
4719 declaration of `f'. */
4720 last_level_to_check = template_class_depth (current_class_type) + 1;
4722 /* Check everything. */
4723 last_level_to_check = 0;
4725 for (parm_level = parms;
4726 parm_level && TMPL_PARMS_DEPTH (parm_level) >= last_level_to_check;
4727 parm_level = TREE_CHAIN (parm_level))
4729 tree inner_parms = TREE_VALUE (parm_level);
4733 ntparms = TREE_VEC_LENGTH (inner_parms);
4734 for (i = 0; i < ntparms; ++i)
4736 if (TREE_VEC_ELT (inner_parms, i) == error_mark_node)
4739 if (TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)))
4744 if (is_friend_decl == 2)
4751 /* Clear out the default argument so that we are not
4753 TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)) = NULL_TREE;
4757 /* At this point, if we're still interested in issuing messages,
4758 they must apply to classes surrounding the object declared. */
4760 msg = G_("default argument for template parameter for class "
4767 /* Worker for push_template_decl_real, called via
4768 for_each_template_parm. DATA is really an int, indicating the
4769 level of the parameters we are interested in. If T is a template
4770 parameter of that level, return nonzero. */
4773 template_parm_this_level_p (tree t, void* data)
4775 int this_level = *(int *)data;
4778 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
4779 level = TEMPLATE_PARM_LEVEL (t);
4781 level = TEMPLATE_TYPE_LEVEL (t);
4782 return level == this_level;
4785 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4786 parameters given by current_template_args, or reuses a
4787 previously existing one, if appropriate. Returns the DECL, or an
4788 equivalent one, if it is replaced via a call to duplicate_decls.
4790 If IS_FRIEND is true, DECL is a friend declaration. */
4793 push_template_decl_real (tree decl, bool is_friend)
4801 int new_template_p = 0;
4802 /* True if the template is a member template, in the sense of
4804 bool member_template_p = false;
4806 if (decl == error_mark_node || !current_template_parms)
4807 return error_mark_node;
4809 /* See if this is a partial specialization. */
4810 is_partial = (DECL_IMPLICIT_TYPEDEF_P (decl)
4811 && TREE_CODE (TREE_TYPE (decl)) != ENUMERAL_TYPE
4812 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)));
4814 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_FRIEND_P (decl))
4818 /* For a friend, we want the context of the friend function, not
4819 the type of which it is a friend. */
4820 ctx = CP_DECL_CONTEXT (decl);
4821 else if (CP_DECL_CONTEXT (decl)
4822 && TREE_CODE (CP_DECL_CONTEXT (decl)) != NAMESPACE_DECL)
4823 /* In the case of a virtual function, we want the class in which
4825 ctx = CP_DECL_CONTEXT (decl);
4827 /* Otherwise, if we're currently defining some class, the DECL
4828 is assumed to be a member of the class. */
4829 ctx = current_scope ();
4831 if (ctx && TREE_CODE (ctx) == NAMESPACE_DECL)
4834 if (!DECL_CONTEXT (decl))
4835 DECL_CONTEXT (decl) = FROB_CONTEXT (current_namespace);
4837 /* See if this is a primary template. */
4838 if (is_friend && ctx)
4839 /* A friend template that specifies a class context, i.e.
4840 template <typename T> friend void A<T>::f();
4844 primary = template_parm_scope_p ();
4848 if (DECL_CLASS_SCOPE_P (decl))
4849 member_template_p = true;
4850 if (TREE_CODE (decl) == TYPE_DECL
4851 && ANON_AGGRNAME_P (DECL_NAME (decl)))
4853 error ("template class without a name");
4854 return error_mark_node;
4856 else if (TREE_CODE (decl) == FUNCTION_DECL)
4858 if (DECL_DESTRUCTOR_P (decl))
4862 A destructor shall not be a member template. */
4863 error ("destructor %qD declared as member template", decl);
4864 return error_mark_node;
4866 if (NEW_DELETE_OPNAME_P (DECL_NAME (decl))
4867 && (!prototype_p (TREE_TYPE (decl))
4868 || TYPE_ARG_TYPES (TREE_TYPE (decl)) == void_list_node
4869 || !TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (decl)))
4870 || (TREE_CHAIN (TYPE_ARG_TYPES ((TREE_TYPE (decl))))
4871 == void_list_node)))
4873 /* [basic.stc.dynamic.allocation]
4875 An allocation function can be a function
4876 template. ... Template allocation functions shall
4877 have two or more parameters. */
4878 error ("invalid template declaration of %qD", decl);
4879 return error_mark_node;
4882 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4883 && CLASS_TYPE_P (TREE_TYPE (decl)))
4885 else if (TREE_CODE (decl) == TYPE_DECL
4886 && TYPE_DECL_ALIAS_P (decl))
4887 /* alias-declaration */
4888 gcc_assert (!DECL_ARTIFICIAL (decl));
4891 error ("template declaration of %q#D", decl);
4892 return error_mark_node;
4896 /* Check to see that the rules regarding the use of default
4897 arguments are not being violated. */
4898 check_default_tmpl_args (decl, current_template_parms,
4899 primary, is_partial, /*is_friend_decl=*/0);
4901 /* Ensure that there are no parameter packs in the type of this
4902 declaration that have not been expanded. */
4903 if (TREE_CODE (decl) == FUNCTION_DECL)
4905 /* Check each of the arguments individually to see if there are
4906 any bare parameter packs. */
4907 tree type = TREE_TYPE (decl);
4908 tree arg = DECL_ARGUMENTS (decl);
4909 tree argtype = TYPE_ARG_TYPES (type);
4911 while (arg && argtype)
4913 if (!FUNCTION_PARAMETER_PACK_P (arg)
4914 && check_for_bare_parameter_packs (TREE_TYPE (arg)))
4916 /* This is a PARM_DECL that contains unexpanded parameter
4917 packs. We have already complained about this in the
4918 check_for_bare_parameter_packs call, so just replace
4919 these types with ERROR_MARK_NODE. */
4920 TREE_TYPE (arg) = error_mark_node;
4921 TREE_VALUE (argtype) = error_mark_node;
4924 arg = DECL_CHAIN (arg);
4925 argtype = TREE_CHAIN (argtype);
4928 /* Check for bare parameter packs in the return type and the
4929 exception specifiers. */
4930 if (check_for_bare_parameter_packs (TREE_TYPE (type)))
4931 /* Errors were already issued, set return type to int
4932 as the frontend doesn't expect error_mark_node as
4934 TREE_TYPE (type) = integer_type_node;
4935 if (check_for_bare_parameter_packs (TYPE_RAISES_EXCEPTIONS (type)))
4936 TYPE_RAISES_EXCEPTIONS (type) = NULL_TREE;
4938 else if (check_for_bare_parameter_packs ((TREE_CODE (decl) == TYPE_DECL
4939 && TYPE_DECL_ALIAS_P (decl))
4940 ? DECL_ORIGINAL_TYPE (decl)
4941 : TREE_TYPE (decl)))
4943 TREE_TYPE (decl) = error_mark_node;
4944 return error_mark_node;
4948 return process_partial_specialization (decl);
4950 args = current_template_args ();
4953 || TREE_CODE (ctx) == FUNCTION_DECL
4954 || (CLASS_TYPE_P (ctx) && TYPE_BEING_DEFINED (ctx))
4955 || (is_friend && !DECL_TEMPLATE_INFO (decl)))
4957 if (DECL_LANG_SPECIFIC (decl)
4958 && DECL_TEMPLATE_INFO (decl)
4959 && DECL_TI_TEMPLATE (decl))
4960 tmpl = DECL_TI_TEMPLATE (decl);
4961 /* If DECL is a TYPE_DECL for a class-template, then there won't
4962 be DECL_LANG_SPECIFIC. The information equivalent to
4963 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4964 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4965 && TYPE_TEMPLATE_INFO (TREE_TYPE (decl))
4966 && TYPE_TI_TEMPLATE (TREE_TYPE (decl)))
4968 /* Since a template declaration already existed for this
4969 class-type, we must be redeclaring it here. Make sure
4970 that the redeclaration is valid. */
4971 redeclare_class_template (TREE_TYPE (decl),
4972 current_template_parms);
4973 /* We don't need to create a new TEMPLATE_DECL; just use the
4974 one we already had. */
4975 tmpl = TYPE_TI_TEMPLATE (TREE_TYPE (decl));
4979 tmpl = build_template_decl (decl, current_template_parms,
4983 if (DECL_LANG_SPECIFIC (decl)
4984 && DECL_TEMPLATE_SPECIALIZATION (decl))
4986 /* A specialization of a member template of a template
4988 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
4989 DECL_TEMPLATE_INFO (tmpl) = DECL_TEMPLATE_INFO (decl);
4990 DECL_TEMPLATE_INFO (decl) = NULL_TREE;
4996 tree a, t, current, parms;
4998 tree tinfo = get_template_info (decl);
5002 error ("template definition of non-template %q#D", decl);
5003 return error_mark_node;
5006 tmpl = TI_TEMPLATE (tinfo);
5008 if (DECL_FUNCTION_TEMPLATE_P (tmpl)
5009 && DECL_TEMPLATE_INFO (decl) && DECL_TI_ARGS (decl)
5010 && DECL_TEMPLATE_SPECIALIZATION (decl)
5011 && DECL_MEMBER_TEMPLATE_P (tmpl))
5015 /* The declaration is a specialization of a member
5016 template, declared outside the class. Therefore, the
5017 innermost template arguments will be NULL, so we
5018 replace them with the arguments determined by the
5019 earlier call to check_explicit_specialization. */
5020 args = DECL_TI_ARGS (decl);
5023 = build_template_decl (decl, current_template_parms,
5025 DECL_TEMPLATE_RESULT (new_tmpl) = decl;
5026 TREE_TYPE (new_tmpl) = TREE_TYPE (decl);
5027 DECL_TI_TEMPLATE (decl) = new_tmpl;
5028 SET_DECL_TEMPLATE_SPECIALIZATION (new_tmpl);
5029 DECL_TEMPLATE_INFO (new_tmpl)
5030 = build_template_info (tmpl, args);
5032 register_specialization (new_tmpl,
5033 most_general_template (tmpl),
5039 /* Make sure the template headers we got make sense. */
5041 parms = DECL_TEMPLATE_PARMS (tmpl);
5042 i = TMPL_PARMS_DEPTH (parms);
5043 if (TMPL_ARGS_DEPTH (args) != i)
5045 error ("expected %d levels of template parms for %q#D, got %d",
5046 i, decl, TMPL_ARGS_DEPTH (args));
5049 for (current = decl; i > 0; --i, parms = TREE_CHAIN (parms))
5051 a = TMPL_ARGS_LEVEL (args, i);
5052 t = INNERMOST_TEMPLATE_PARMS (parms);
5054 if (TREE_VEC_LENGTH (t) != TREE_VEC_LENGTH (a))
5056 if (current == decl)
5057 error ("got %d template parameters for %q#D",
5058 TREE_VEC_LENGTH (a), decl);
5060 error ("got %d template parameters for %q#T",
5061 TREE_VEC_LENGTH (a), current);
5062 error (" but %d required", TREE_VEC_LENGTH (t));
5063 return error_mark_node;
5066 if (current == decl)
5068 else if (current == NULL_TREE)
5069 /* Can happen in erroneous input. */
5072 current = (TYPE_P (current)
5073 ? TYPE_CONTEXT (current)
5074 : DECL_CONTEXT (current));
5077 /* Check that the parms are used in the appropriate qualifying scopes
5078 in the declarator. */
5079 if (!comp_template_args
5081 TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (tmpl)))))
5084 template arguments to %qD do not match original template %qD",
5085 decl, DECL_TEMPLATE_RESULT (tmpl));
5086 if (!uses_template_parms (TI_ARGS (tinfo)))
5087 inform (input_location, "use template<> for an explicit specialization");
5088 /* Avoid crash in import_export_decl. */
5089 DECL_INTERFACE_KNOWN (decl) = 1;
5090 return error_mark_node;
5094 DECL_TEMPLATE_RESULT (tmpl) = decl;
5095 TREE_TYPE (tmpl) = TREE_TYPE (decl);
5097 /* Push template declarations for global functions and types. Note
5098 that we do not try to push a global template friend declared in a
5099 template class; such a thing may well depend on the template
5100 parameters of the class. */
5101 if (new_template_p && !ctx
5102 && !(is_friend && template_class_depth (current_class_type) > 0))
5104 tmpl = pushdecl_namespace_level (tmpl, is_friend);
5105 if (tmpl == error_mark_node)
5106 return error_mark_node;
5108 /* Hide template friend classes that haven't been declared yet. */
5109 if (is_friend && TREE_CODE (decl) == TYPE_DECL)
5111 DECL_ANTICIPATED (tmpl) = 1;
5112 DECL_FRIEND_P (tmpl) = 1;
5118 tree parms = DECL_TEMPLATE_PARMS (tmpl);
5121 DECL_PRIMARY_TEMPLATE (tmpl) = tmpl;
5122 if (DECL_CONV_FN_P (tmpl))
5124 int depth = TMPL_PARMS_DEPTH (parms);
5126 /* It is a conversion operator. See if the type converted to
5127 depends on innermost template operands. */
5129 if (uses_template_parms_level (TREE_TYPE (TREE_TYPE (tmpl)),
5131 DECL_TEMPLATE_CONV_FN_P (tmpl) = 1;
5134 /* Give template template parms a DECL_CONTEXT of the template
5135 for which they are a parameter. */
5136 parms = INNERMOST_TEMPLATE_PARMS (parms);
5137 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
5139 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
5140 if (TREE_CODE (parm) == TEMPLATE_DECL)
5141 DECL_CONTEXT (parm) = tmpl;
5145 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5146 back to its most general template. If TMPL is a specialization,
5147 ARGS may only have the innermost set of arguments. Add the missing
5148 argument levels if necessary. */
5149 if (DECL_TEMPLATE_INFO (tmpl))
5150 args = add_outermost_template_args (DECL_TI_ARGS (tmpl), args);
5152 info = build_template_info (tmpl, args);
5154 if (DECL_IMPLICIT_TYPEDEF_P (decl))
5155 SET_TYPE_TEMPLATE_INFO (TREE_TYPE (tmpl), info);
5158 if (primary && !DECL_LANG_SPECIFIC (decl))
5159 retrofit_lang_decl (decl);
5160 if (DECL_LANG_SPECIFIC (decl))
5161 DECL_TEMPLATE_INFO (decl) = info;
5164 return DECL_TEMPLATE_RESULT (tmpl);
5168 push_template_decl (tree decl)
5170 return push_template_decl_real (decl, false);
5173 /* Called when a class template TYPE is redeclared with the indicated
5174 template PARMS, e.g.:
5176 template <class T> struct S;
5177 template <class T> struct S {}; */
5180 redeclare_class_template (tree type, tree parms)
5186 if (!TYPE_TEMPLATE_INFO (type))
5188 error ("%qT is not a template type", type);
5192 tmpl = TYPE_TI_TEMPLATE (type);
5193 if (!PRIMARY_TEMPLATE_P (tmpl))
5194 /* The type is nested in some template class. Nothing to worry
5195 about here; there are no new template parameters for the nested
5201 error ("template specifiers not specified in declaration of %qD",
5206 parms = INNERMOST_TEMPLATE_PARMS (parms);
5207 tmpl_parms = DECL_INNERMOST_TEMPLATE_PARMS (tmpl);
5209 if (TREE_VEC_LENGTH (parms) != TREE_VEC_LENGTH (tmpl_parms))
5211 error_n (input_location, TREE_VEC_LENGTH (parms),
5212 "redeclared with %d template parameter",
5213 "redeclared with %d template parameters",
5214 TREE_VEC_LENGTH (parms));
5215 inform_n (input_location, TREE_VEC_LENGTH (tmpl_parms),
5216 "previous declaration %q+D used %d template parameter",
5217 "previous declaration %q+D used %d template parameters",
5218 tmpl, TREE_VEC_LENGTH (tmpl_parms));
5222 for (i = 0; i < TREE_VEC_LENGTH (tmpl_parms); ++i)
5229 if (TREE_VEC_ELT (tmpl_parms, i) == error_mark_node
5230 || TREE_VEC_ELT (parms, i) == error_mark_node)
5233 tmpl_parm = TREE_VALUE (TREE_VEC_ELT (tmpl_parms, i));
5234 if (tmpl_parm == error_mark_node)
5237 parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
5238 tmpl_default = TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i));
5239 parm_default = TREE_PURPOSE (TREE_VEC_ELT (parms, i));
5241 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5243 if (TREE_CODE (tmpl_parm) != TREE_CODE (parm)
5244 || (TREE_CODE (tmpl_parm) != TYPE_DECL
5245 && !same_type_p (TREE_TYPE (tmpl_parm), TREE_TYPE (parm)))
5246 || (TREE_CODE (tmpl_parm) != PARM_DECL
5247 && (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (tmpl_parm))
5248 != TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm))))
5249 || (TREE_CODE (tmpl_parm) == PARM_DECL
5250 && (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (tmpl_parm))
5251 != TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))))
5253 error ("template parameter %q+#D", tmpl_parm);
5254 error ("redeclared here as %q#D", parm);
5258 if (tmpl_default != NULL_TREE && parm_default != NULL_TREE)
5260 /* We have in [temp.param]:
5262 A template-parameter may not be given default arguments
5263 by two different declarations in the same scope. */
5264 error_at (input_location, "redefinition of default argument for %q#D", parm);
5265 inform (DECL_SOURCE_LOCATION (tmpl_parm),
5266 "original definition appeared here");
5270 if (parm_default != NULL_TREE)
5271 /* Update the previous template parameters (which are the ones
5272 that will really count) with the new default value. */
5273 TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i)) = parm_default;
5274 else if (tmpl_default != NULL_TREE)
5275 /* Update the new parameters, too; they'll be used as the
5276 parameters for any members. */
5277 TREE_PURPOSE (TREE_VEC_ELT (parms, i)) = tmpl_default;
5283 /* Simplify EXPR if it is a non-dependent expression. Returns the
5284 (possibly simplified) expression. */
5287 fold_non_dependent_expr_sfinae (tree expr, tsubst_flags_t complain)
5289 if (expr == NULL_TREE)
5292 /* If we're in a template, but EXPR isn't value dependent, simplify
5293 it. We're supposed to treat:
5295 template <typename T> void f(T[1 + 1]);
5296 template <typename T> void f(T[2]);
5298 as two declarations of the same function, for example. */
5299 if (processing_template_decl
5300 && !type_dependent_expression_p (expr)
5301 && potential_constant_expression (expr)
5302 && !value_dependent_expression_p (expr))
5304 HOST_WIDE_INT saved_processing_template_decl;
5306 saved_processing_template_decl = processing_template_decl;
5307 processing_template_decl = 0;
5308 expr = tsubst_copy_and_build (expr,
5311 /*in_decl=*/NULL_TREE,
5312 /*function_p=*/false,
5313 /*integral_constant_expression_p=*/true);
5314 processing_template_decl = saved_processing_template_decl;
5320 fold_non_dependent_expr (tree expr)
5322 return fold_non_dependent_expr_sfinae (expr, tf_error);
5325 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5326 template declaration, or a TYPE_DECL for an alias declaration. */
5329 alias_type_or_template_p (tree t)
5333 return ((TREE_CODE (t) == TYPE_DECL && TYPE_DECL_ALIAS_P (t))
5336 && TYPE_DECL_ALIAS_P (TYPE_NAME (t)))
5337 || DECL_ALIAS_TEMPLATE_P (t));
5340 /* Return TRUE iff is a specialization of an alias template. */
5343 alias_template_specialization_p (tree t)
5347 return (primary_template_instantiation_p (t)
5348 && DECL_ALIAS_TEMPLATE_P (TYPE_TI_TEMPLATE (t)));
5351 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5352 must be a function or a pointer-to-function type, as specified
5353 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5354 and check that the resulting function has external linkage. */
5357 convert_nontype_argument_function (tree type, tree expr)
5361 linkage_kind linkage;
5363 fn = instantiate_type (type, fns, tf_none);
5364 if (fn == error_mark_node)
5365 return error_mark_node;
5368 if (TREE_CODE (fn_no_ptr) == ADDR_EXPR)
5369 fn_no_ptr = TREE_OPERAND (fn_no_ptr, 0);
5370 if (BASELINK_P (fn_no_ptr))
5371 fn_no_ptr = BASELINK_FUNCTIONS (fn_no_ptr);
5373 /* [temp.arg.nontype]/1
5375 A template-argument for a non-type, non-template template-parameter
5378 -- the address of an object or function with external [C++11: or
5379 internal] linkage. */
5380 linkage = decl_linkage (fn_no_ptr);
5381 if (cxx_dialect >= cxx0x ? linkage == lk_none : linkage != lk_external)
5383 if (cxx_dialect >= cxx0x)
5384 error ("%qE is not a valid template argument for type %qT "
5385 "because %qD has no linkage",
5386 expr, type, fn_no_ptr);
5388 error ("%qE is not a valid template argument for type %qT "
5389 "because %qD does not have external linkage",
5390 expr, type, fn_no_ptr);
5397 /* Subroutine of convert_nontype_argument.
5398 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5399 Emit an error otherwise. */
5402 check_valid_ptrmem_cst_expr (tree type, tree expr,
5403 tsubst_flags_t complain)
5406 if (expr && (null_ptr_cst_p (expr) || TREE_CODE (expr) == PTRMEM_CST))
5408 if (cxx_dialect >= cxx0x && null_member_pointer_value_p (expr))
5410 if (complain & tf_error)
5412 error ("%qE is not a valid template argument for type %qT",
5414 error ("it must be a pointer-to-member of the form %<&X::Y%>");
5419 /* Returns TRUE iff the address of OP is value-dependent.
5421 14.6.2.4 [temp.dep.temp]:
5422 A non-integral non-type template-argument is dependent if its type is
5423 dependent or it has either of the following forms
5426 and contains a nested-name-specifier which specifies a class-name that
5427 names a dependent type.
5429 We generalize this to just say that the address of a member of a
5430 dependent class is value-dependent; the above doesn't cover the
5431 address of a static data member named with an unqualified-id. */
5434 has_value_dependent_address (tree op)
5436 /* We could use get_inner_reference here, but there's no need;
5437 this is only relevant for template non-type arguments, which
5438 can only be expressed as &id-expression. */
5441 tree ctx = CP_DECL_CONTEXT (op);
5442 if (TYPE_P (ctx) && dependent_type_p (ctx))
5449 /* The next set of functions are used for providing helpful explanatory
5450 diagnostics for failed overload resolution. Their messages should be
5451 indented by two spaces for consistency with the messages in
5455 unify_success (bool explain_p ATTRIBUTE_UNUSED)
5461 unify_parameter_deduction_failure (bool explain_p, tree parm)
5464 inform (input_location,
5465 " couldn't deduce template parameter %qD", parm);
5470 unify_invalid (bool explain_p ATTRIBUTE_UNUSED)
5476 unify_cv_qual_mismatch (bool explain_p, tree parm, tree arg)
5479 inform (input_location,
5480 " types %qT and %qT have incompatible cv-qualifiers",
5486 unify_type_mismatch (bool explain_p, tree parm, tree arg)
5489 inform (input_location, " mismatched types %qT and %qT", parm, arg);
5494 unify_parameter_pack_mismatch (bool explain_p, tree parm, tree arg)
5497 inform (input_location,
5498 " template parameter %qD is not a parameter pack, but "
5505 unify_ptrmem_cst_mismatch (bool explain_p, tree parm, tree arg)
5508 inform (input_location,
5509 " template argument %qE does not match "
5510 "pointer-to-member constant %qE",
5516 unify_expression_unequal (bool explain_p, tree parm, tree arg)
5519 inform (input_location, " %qE is not equivalent to %qE", parm, arg);
5524 unify_parameter_pack_inconsistent (bool explain_p, tree old_arg, tree new_arg)
5527 inform (input_location,
5528 " inconsistent parameter pack deduction with %qT and %qT",
5534 unify_inconsistency (bool explain_p, tree parm, tree first, tree second)
5539 inform (input_location,
5540 " deduced conflicting types for parameter %qT (%qT and %qT)",
5541 parm, first, second);
5543 inform (input_location,
5544 " deduced conflicting values for non-type parameter "
5545 "%qE (%qE and %qE)", parm, first, second);
5551 unify_vla_arg (bool explain_p, tree arg)
5554 inform (input_location,
5555 " variable-sized array type %qT is not "
5556 "a valid template argument",
5562 unify_method_type_error (bool explain_p, tree arg)
5565 inform (input_location,
5566 " member function type %qT is not a valid template argument",
5572 unify_arity (bool explain_p, int have, int wanted)
5575 inform_n (input_location, wanted,
5576 " candidate expects %d argument, %d provided",
5577 " candidate expects %d arguments, %d provided",
5583 unify_too_many_arguments (bool explain_p, int have, int wanted)
5585 return unify_arity (explain_p, have, wanted);
5589 unify_too_few_arguments (bool explain_p, int have, int wanted)
5591 return unify_arity (explain_p, have, wanted);
5595 unify_arg_conversion (bool explain_p, tree to_type,
5596 tree from_type, tree arg)
5599 inform (input_location, " cannot convert %qE (type %qT) to type %qT",
5600 arg, from_type, to_type);
5605 unify_no_common_base (bool explain_p, enum template_base_result r,
5606 tree parm, tree arg)
5611 case tbr_ambiguous_baseclass:
5612 inform (input_location, " %qT is an ambiguous base class of %qT",
5616 inform (input_location, " %qT is not derived from %qT", arg, parm);
5623 unify_inconsistent_template_template_parameters (bool explain_p)
5626 inform (input_location,
5627 " template parameters of a template template argument are "
5628 "inconsistent with other deduced template arguments");
5633 unify_template_deduction_failure (bool explain_p, tree parm, tree arg)
5636 inform (input_location,
5637 " can't deduce a template for %qT from non-template type %qT",
5643 unify_template_argument_mismatch (bool explain_p, tree parm, tree arg)
5646 inform (input_location,
5647 " template argument %qE does not match %qD", arg, parm);
5652 unify_overload_resolution_failure (bool explain_p, tree arg)
5655 inform (input_location,
5656 " could not resolve address from overloaded function %qE",
5661 /* Attempt to convert the non-type template parameter EXPR to the
5662 indicated TYPE. If the conversion is successful, return the
5663 converted value. If the conversion is unsuccessful, return
5664 NULL_TREE if we issued an error message, or error_mark_node if we
5665 did not. We issue error messages for out-and-out bad template
5666 parameters, but not simply because the conversion failed, since we
5667 might be just trying to do argument deduction. Both TYPE and EXPR
5668 must be non-dependent.
5670 The conversion follows the special rules described in
5671 [temp.arg.nontype], and it is much more strict than an implicit
5674 This function is called twice for each template argument (see
5675 lookup_template_class for a more accurate description of this
5676 problem). This means that we need to handle expressions which
5677 are not valid in a C++ source, but can be created from the
5678 first call (for instance, casts to perform conversions). These
5679 hacks can go away after we fix the double coercion problem. */
5682 convert_nontype_argument (tree type, tree expr, tsubst_flags_t complain)
5686 /* Detect immediately string literals as invalid non-type argument.
5687 This special-case is not needed for correctness (we would easily
5688 catch this later), but only to provide better diagnostic for this
5689 common user mistake. As suggested by DR 100, we do not mention
5690 linkage issues in the diagnostic as this is not the point. */
5691 /* FIXME we're making this OK. */
5692 if (TREE_CODE (expr) == STRING_CST)
5694 if (complain & tf_error)
5695 error ("%qE is not a valid template argument for type %qT "
5696 "because string literals can never be used in this context",
5701 /* Add the ADDR_EXPR now for the benefit of
5702 value_dependent_expression_p. */
5703 if (TYPE_PTROBV_P (type)
5704 && TREE_CODE (TREE_TYPE (expr)) == ARRAY_TYPE)
5705 expr = decay_conversion (expr);
5707 /* If we are in a template, EXPR may be non-dependent, but still
5708 have a syntactic, rather than semantic, form. For example, EXPR
5709 might be a SCOPE_REF, rather than the VAR_DECL to which the
5710 SCOPE_REF refers. Preserving the qualifying scope is necessary
5711 so that access checking can be performed when the template is
5712 instantiated -- but here we need the resolved form so that we can
5713 convert the argument. */
5714 if (TYPE_REF_OBJ_P (type)
5715 && has_value_dependent_address (expr))
5716 /* If we want the address and it's value-dependent, don't fold. */;
5717 else if (!type_unknown_p (expr))
5718 expr = fold_non_dependent_expr_sfinae (expr, complain);
5719 if (error_operand_p (expr))
5720 return error_mark_node;
5721 expr_type = TREE_TYPE (expr);
5722 if (TREE_CODE (type) == REFERENCE_TYPE)
5723 expr = mark_lvalue_use (expr);
5725 expr = mark_rvalue_use (expr);
5727 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
5728 to a non-type argument of "nullptr". */
5729 if (expr == nullptr_node
5730 && (TYPE_PTR_P (type) || TYPE_PTR_TO_MEMBER_P (type)))
5731 expr = convert (type, expr);
5733 /* In C++11, integral or enumeration non-type template arguments can be
5734 arbitrary constant expressions. Pointer and pointer to
5735 member arguments can be general constant expressions that evaluate
5736 to a null value, but otherwise still need to be of a specific form. */
5737 if (cxx_dialect >= cxx0x)
5739 if (TREE_CODE (expr) == PTRMEM_CST)
5740 /* A PTRMEM_CST is already constant, and a valid template
5741 argument for a parameter of pointer to member type, we just want
5742 to leave it in that form rather than lower it to a
5744 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
5745 expr = maybe_constant_value (expr);
5746 else if (TYPE_PTR_P (type)
5747 || TYPE_PTR_TO_MEMBER_P (type))
5749 tree folded = maybe_constant_value (expr);
5750 if (TYPE_PTR_P (type) ? integer_zerop (folded)
5751 : null_member_pointer_value_p (folded))
5756 /* HACK: Due to double coercion, we can get a
5757 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5758 which is the tree that we built on the first call (see
5759 below when coercing to reference to object or to reference to
5760 function). We just strip everything and get to the arg.
5761 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5763 if (TYPE_REF_OBJ_P (type) || TYPE_REFFN_P (type))
5765 tree probe_type, probe = expr;
5766 if (REFERENCE_REF_P (probe))
5767 probe = TREE_OPERAND (probe, 0);
5768 probe_type = TREE_TYPE (probe);
5769 if (TREE_CODE (probe) == NOP_EXPR)
5771 /* ??? Maybe we could use convert_from_reference here, but we
5772 would need to relax its constraints because the NOP_EXPR
5773 could actually change the type to something more cv-qualified,
5774 and this is not folded by convert_from_reference. */
5775 tree addr = TREE_OPERAND (probe, 0);
5776 gcc_assert (TREE_CODE (probe_type) == REFERENCE_TYPE);
5777 gcc_assert (TREE_CODE (addr) == ADDR_EXPR);
5778 gcc_assert (TREE_CODE (TREE_TYPE (addr)) == POINTER_TYPE);
5779 gcc_assert (same_type_ignoring_top_level_qualifiers_p
5780 (TREE_TYPE (probe_type),
5781 TREE_TYPE (TREE_TYPE (addr))));
5783 expr = TREE_OPERAND (addr, 0);
5784 expr_type = TREE_TYPE (expr);
5788 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5789 parameter is a pointer to object, through decay and
5790 qualification conversion. Let's strip everything. */
5791 else if (TREE_CODE (expr) == NOP_EXPR && TYPE_PTROBV_P (type))
5794 gcc_assert (TREE_CODE (expr) == ADDR_EXPR);
5795 gcc_assert (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE);
5796 /* Skip the ADDR_EXPR only if it is part of the decay for
5797 an array. Otherwise, it is part of the original argument
5798 in the source code. */
5799 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == ARRAY_TYPE)
5800 expr = TREE_OPERAND (expr, 0);
5801 expr_type = TREE_TYPE (expr);
5804 /* [temp.arg.nontype]/5, bullet 1
5806 For a non-type template-parameter of integral or enumeration type,
5807 integral promotions (_conv.prom_) and integral conversions
5808 (_conv.integral_) are applied. */
5809 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
5811 tree t = build_integral_nontype_arg_conv (type, expr, complain);
5812 t = maybe_constant_value (t);
5813 if (t != error_mark_node)
5816 if (!same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (expr)))
5817 return error_mark_node;
5819 /* Notice that there are constant expressions like '4 % 0' which
5820 do not fold into integer constants. */
5821 if (TREE_CODE (expr) != INTEGER_CST)
5823 if (complain & tf_error)
5825 int errs = errorcount, warns = warningcount;
5826 if (processing_template_decl
5827 && !require_potential_constant_expression (expr))
5829 expr = cxx_constant_value (expr);
5830 if (errorcount > errs || warningcount > warns)
5831 inform (EXPR_LOC_OR_HERE (expr),
5832 "in template argument for type %qT ", type);
5833 if (expr == error_mark_node)
5835 /* else cxx_constant_value complained but gave us
5836 a real constant, so go ahead. */
5837 gcc_assert (TREE_CODE (expr) == INTEGER_CST);
5843 /* [temp.arg.nontype]/5, bullet 2
5845 For a non-type template-parameter of type pointer to object,
5846 qualification conversions (_conv.qual_) and the array-to-pointer
5847 conversion (_conv.array_) are applied. */
5848 else if (TYPE_PTROBV_P (type))
5850 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5852 A template-argument for a non-type, non-template template-parameter
5853 shall be one of: [...]
5855 -- the name of a non-type template-parameter;
5856 -- the address of an object or function with external linkage, [...]
5857 expressed as "& id-expression" where the & is optional if the name
5858 refers to a function or array, or if the corresponding
5859 template-parameter is a reference.
5861 Here, we do not care about functions, as they are invalid anyway
5862 for a parameter of type pointer-to-object. */
5864 if (DECL_P (expr) && DECL_TEMPLATE_PARM_P (expr))
5865 /* Non-type template parameters are OK. */
5867 else if (cxx_dialect >= cxx0x && integer_zerop (expr))
5868 /* Null pointer values are OK in C++11. */;
5869 else if (TREE_CODE (expr) != ADDR_EXPR
5870 && TREE_CODE (expr_type) != ARRAY_TYPE)
5872 if (TREE_CODE (expr) == VAR_DECL)
5874 error ("%qD is not a valid template argument "
5875 "because %qD is a variable, not the address of "
5880 /* Other values, like integer constants, might be valid
5881 non-type arguments of some other type. */
5882 return error_mark_node;
5888 decl = ((TREE_CODE (expr) == ADDR_EXPR)
5889 ? TREE_OPERAND (expr, 0) : expr);
5890 if (TREE_CODE (decl) != VAR_DECL)
5892 error ("%qE is not a valid template argument of type %qT "
5893 "because %qE is not a variable",
5897 else if (cxx_dialect < cxx0x && !DECL_EXTERNAL_LINKAGE_P (decl))
5899 error ("%qE is not a valid template argument of type %qT "
5900 "because %qD does not have external linkage",
5904 else if (cxx_dialect >= cxx0x && decl_linkage (decl) == lk_none)
5906 error ("%qE is not a valid template argument of type %qT "
5907 "because %qD has no linkage",
5913 expr = decay_conversion (expr);
5914 if (expr == error_mark_node)
5915 return error_mark_node;
5917 expr = perform_qualification_conversions (type, expr);
5918 if (expr == error_mark_node)
5919 return error_mark_node;
5921 /* [temp.arg.nontype]/5, bullet 3
5923 For a non-type template-parameter of type reference to object, no
5924 conversions apply. The type referred to by the reference may be more
5925 cv-qualified than the (otherwise identical) type of the
5926 template-argument. The template-parameter is bound directly to the
5927 template-argument, which must be an lvalue. */
5928 else if (TYPE_REF_OBJ_P (type))
5930 if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type),
5932 return error_mark_node;
5934 if (!at_least_as_qualified_p (TREE_TYPE (type), expr_type))
5936 error ("%qE is not a valid template argument for type %qT "
5937 "because of conflicts in cv-qualification", expr, type);
5941 if (!real_lvalue_p (expr))
5943 error ("%qE is not a valid template argument for type %qT "
5944 "because it is not an lvalue", expr, type);
5948 /* [temp.arg.nontype]/1
5950 A template-argument for a non-type, non-template template-parameter
5951 shall be one of: [...]
5953 -- the address of an object or function with external linkage. */
5954 if (TREE_CODE (expr) == INDIRECT_REF
5955 && TYPE_REF_OBJ_P (TREE_TYPE (TREE_OPERAND (expr, 0))))
5957 expr = TREE_OPERAND (expr, 0);
5960 error ("%q#D is not a valid template argument for type %qT "
5961 "because a reference variable does not have a constant "
5962 "address", expr, type);
5969 error ("%qE is not a valid template argument for type %qT "
5970 "because it is not an object with external linkage",
5975 if (!DECL_EXTERNAL_LINKAGE_P (expr))
5977 error ("%qE is not a valid template argument for type %qT "
5978 "because object %qD has not external linkage",
5983 expr = build_nop (type, build_address (expr));
5985 /* [temp.arg.nontype]/5, bullet 4
5987 For a non-type template-parameter of type pointer to function, only
5988 the function-to-pointer conversion (_conv.func_) is applied. If the
5989 template-argument represents a set of overloaded functions (or a
5990 pointer to such), the matching function is selected from the set
5992 else if (TYPE_PTRFN_P (type))
5994 /* If the argument is a template-id, we might not have enough
5995 context information to decay the pointer. */
5996 if (!type_unknown_p (expr_type))
5998 expr = decay_conversion (expr);
5999 if (expr == error_mark_node)
6000 return error_mark_node;
6003 if (cxx_dialect >= cxx0x && integer_zerop (expr))
6004 /* Null pointer values are OK in C++11. */
6005 return perform_qualification_conversions (type, expr);
6007 expr = convert_nontype_argument_function (type, expr);
6008 if (!expr || expr == error_mark_node)
6011 if (TREE_CODE (expr) != ADDR_EXPR)
6013 error ("%qE is not a valid template argument for type %qT", expr, type);
6014 error ("it must be the address of a function with external linkage");
6018 /* [temp.arg.nontype]/5, bullet 5
6020 For a non-type template-parameter of type reference to function, no
6021 conversions apply. If the template-argument represents a set of
6022 overloaded functions, the matching function is selected from the set
6024 else if (TYPE_REFFN_P (type))
6026 if (TREE_CODE (expr) == ADDR_EXPR)
6028 error ("%qE is not a valid template argument for type %qT "
6029 "because it is a pointer", expr, type);
6030 inform (input_location, "try using %qE instead", TREE_OPERAND (expr, 0));
6034 expr = convert_nontype_argument_function (TREE_TYPE (type), expr);
6035 if (!expr || expr == error_mark_node)
6038 expr = build_nop (type, build_address (expr));
6040 /* [temp.arg.nontype]/5, bullet 6
6042 For a non-type template-parameter of type pointer to member function,
6043 no conversions apply. If the template-argument represents a set of
6044 overloaded member functions, the matching member function is selected
6045 from the set (_over.over_). */
6046 else if (TYPE_PTRMEMFUNC_P (type))
6048 expr = instantiate_type (type, expr, tf_none);
6049 if (expr == error_mark_node)
6050 return error_mark_node;
6052 /* [temp.arg.nontype] bullet 1 says the pointer to member
6053 expression must be a pointer-to-member constant. */
6054 if (!check_valid_ptrmem_cst_expr (type, expr, complain))
6055 return error_mark_node;
6057 /* There is no way to disable standard conversions in
6058 resolve_address_of_overloaded_function (called by
6059 instantiate_type). It is possible that the call succeeded by
6060 converting &B::I to &D::I (where B is a base of D), so we need
6061 to reject this conversion here.
6063 Actually, even if there was a way to disable standard conversions,
6064 it would still be better to reject them here so that we can
6065 provide a superior diagnostic. */
6066 if (!same_type_p (TREE_TYPE (expr), type))
6068 error ("%qE is not a valid template argument for type %qT "
6069 "because it is of type %qT", expr, type,
6071 /* If we are just one standard conversion off, explain. */
6072 if (can_convert (type, TREE_TYPE (expr)))
6073 inform (input_location,
6074 "standard conversions are not allowed in this context");
6078 /* [temp.arg.nontype]/5, bullet 7
6080 For a non-type template-parameter of type pointer to data member,
6081 qualification conversions (_conv.qual_) are applied. */
6082 else if (TYPE_PTRMEM_P (type))
6084 /* [temp.arg.nontype] bullet 1 says the pointer to member
6085 expression must be a pointer-to-member constant. */
6086 if (!check_valid_ptrmem_cst_expr (type, expr, complain))
6087 return error_mark_node;
6089 expr = perform_qualification_conversions (type, expr);
6090 if (expr == error_mark_node)
6093 else if (NULLPTR_TYPE_P (type))
6095 if (expr != nullptr_node)
6097 error ("%qE is not a valid template argument for type %qT "
6098 "because it is of type %qT", expr, type, TREE_TYPE (expr));
6103 /* A template non-type parameter must be one of the above. */
6107 /* Sanity check: did we actually convert the argument to the
6109 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6110 (type, TREE_TYPE (expr)));
6114 /* Subroutine of coerce_template_template_parms, which returns 1 if
6115 PARM_PARM and ARG_PARM match using the rule for the template
6116 parameters of template template parameters. Both PARM and ARG are
6117 template parameters; the rest of the arguments are the same as for
6118 coerce_template_template_parms.
6121 coerce_template_template_parm (tree parm,
6123 tsubst_flags_t complain,
6127 if (arg == NULL_TREE || arg == error_mark_node
6128 || parm == NULL_TREE || parm == error_mark_node)
6131 if (TREE_CODE (arg) != TREE_CODE (parm))
6134 switch (TREE_CODE (parm))
6137 /* We encounter instantiations of templates like
6138 template <template <template <class> class> class TT>
6141 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
6142 tree argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
6144 if (!coerce_template_template_parms
6145 (parmparm, argparm, complain, in_decl, outer_args))
6151 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (arg))
6152 && !TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
6153 /* Argument is a parameter pack but parameter is not. */
6158 /* The tsubst call is used to handle cases such as
6160 template <int> class C {};
6161 template <class T, template <T> class TT> class D {};
6164 i.e. the parameter list of TT depends on earlier parameters. */
6165 if (!uses_template_parms (TREE_TYPE (arg))
6167 (tsubst (TREE_TYPE (parm), outer_args, complain, in_decl),
6171 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (arg))
6172 && !TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
6173 /* Argument is a parameter pack but parameter is not. */
6186 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
6187 template template parameters. Both PARM_PARMS and ARG_PARMS are
6188 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
6191 Consider the example:
6192 template <class T> class A;
6193 template<template <class U> class TT> class B;
6195 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
6196 the parameters to A, and OUTER_ARGS contains A. */
6199 coerce_template_template_parms (tree parm_parms,
6201 tsubst_flags_t complain,
6205 int nparms, nargs, i;
6209 gcc_assert (TREE_CODE (parm_parms) == TREE_VEC);
6210 gcc_assert (TREE_CODE (arg_parms) == TREE_VEC);
6212 nparms = TREE_VEC_LENGTH (parm_parms);
6213 nargs = TREE_VEC_LENGTH (arg_parms);
6215 /* Determine whether we have a parameter pack at the end of the
6216 template template parameter's template parameter list. */
6217 if (TREE_VEC_ELT (parm_parms, nparms - 1) != error_mark_node)
6219 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, nparms - 1));
6221 if (parm == error_mark_node)
6224 switch (TREE_CODE (parm))
6228 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
6233 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
6243 && !(variadic_p && nargs >= nparms - 1))
6246 /* Check all of the template parameters except the parameter pack at
6247 the end (if any). */
6248 for (i = 0; i < nparms - variadic_p; ++i)
6250 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node
6251 || TREE_VEC_ELT (arg_parms, i) == error_mark_node)
6254 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
6255 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
6257 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
6265 /* Check each of the template parameters in the template
6266 argument against the template parameter pack at the end of
6267 the template template parameter. */
6268 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node)
6271 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
6273 for (; i < nargs; ++i)
6275 if (TREE_VEC_ELT (arg_parms, i) == error_mark_node)
6278 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
6280 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
6289 /* Verifies that the deduced template arguments (in TARGS) for the
6290 template template parameters (in TPARMS) represent valid bindings,
6291 by comparing the template parameter list of each template argument
6292 to the template parameter list of its corresponding template
6293 template parameter, in accordance with DR150. This
6294 routine can only be called after all template arguments have been
6295 deduced. It will return TRUE if all of the template template
6296 parameter bindings are okay, FALSE otherwise. */
6298 template_template_parm_bindings_ok_p (tree tparms, tree targs)
6300 int i, ntparms = TREE_VEC_LENGTH (tparms);
6303 /* We're dealing with template parms in this process. */
6304 ++processing_template_decl;
6306 targs = INNERMOST_TEMPLATE_ARGS (targs);
6308 for (i = 0; i < ntparms; ++i)
6310 tree tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
6311 tree targ = TREE_VEC_ELT (targs, i);
6313 if (TREE_CODE (tparm) == TEMPLATE_DECL && targ)
6315 tree packed_args = NULL_TREE;
6318 if (ARGUMENT_PACK_P (targ))
6320 /* Look inside the argument pack. */
6321 packed_args = ARGUMENT_PACK_ARGS (targ);
6322 len = TREE_VEC_LENGTH (packed_args);
6325 for (idx = 0; idx < len; ++idx)
6327 tree targ_parms = NULL_TREE;
6330 /* Extract the next argument from the argument
6332 targ = TREE_VEC_ELT (packed_args, idx);
6334 if (PACK_EXPANSION_P (targ))
6335 /* Look at the pattern of the pack expansion. */
6336 targ = PACK_EXPANSION_PATTERN (targ);
6338 /* Extract the template parameters from the template
6340 if (TREE_CODE (targ) == TEMPLATE_DECL)
6341 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (targ);
6342 else if (TREE_CODE (targ) == TEMPLATE_TEMPLATE_PARM)
6343 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (TYPE_NAME (targ));
6345 /* Verify that we can coerce the template template
6346 parameters from the template argument to the template
6347 parameter. This requires an exact match. */
6349 && !coerce_template_template_parms
6350 (DECL_INNERMOST_TEMPLATE_PARMS (tparm),
6365 --processing_template_decl;
6369 /* Since type attributes aren't mangled, we need to strip them from
6370 template type arguments. */
6373 canonicalize_type_argument (tree arg, tsubst_flags_t complain)
6376 if (!arg || arg == error_mark_node || arg == TYPE_CANONICAL (arg))
6378 mv = TYPE_MAIN_VARIANT (arg);
6379 arg = strip_typedefs (arg);
6380 if (TYPE_ALIGN (arg) != TYPE_ALIGN (mv)
6381 || TYPE_ATTRIBUTES (arg) != TYPE_ATTRIBUTES (mv))
6383 if (complain & tf_warning)
6384 warning (0, "ignoring attributes on template argument %qT", arg);
6385 arg = build_aligned_type (arg, TYPE_ALIGN (mv));
6386 arg = cp_build_type_attribute_variant (arg, TYPE_ATTRIBUTES (mv));
6391 /* Convert the indicated template ARG as necessary to match the
6392 indicated template PARM. Returns the converted ARG, or
6393 error_mark_node if the conversion was unsuccessful. Error and
6394 warning messages are issued under control of COMPLAIN. This
6395 conversion is for the Ith parameter in the parameter list. ARGS is
6396 the full set of template arguments deduced so far. */
6399 convert_template_argument (tree parm,
6402 tsubst_flags_t complain,
6408 int is_type, requires_type, is_tmpl_type, requires_tmpl_type;
6410 if (TREE_CODE (arg) == TREE_LIST
6411 && TREE_CODE (TREE_VALUE (arg)) == OFFSET_REF)
6413 /* The template argument was the name of some
6414 member function. That's usually
6415 invalid, but static members are OK. In any
6416 case, grab the underlying fields/functions
6417 and issue an error later if required. */
6418 orig_arg = TREE_VALUE (arg);
6419 TREE_TYPE (arg) = unknown_type_node;
6424 requires_tmpl_type = TREE_CODE (parm) == TEMPLATE_DECL;
6425 requires_type = (TREE_CODE (parm) == TYPE_DECL
6426 || requires_tmpl_type);
6428 /* When determining whether an argument pack expansion is a template,
6429 look at the pattern. */
6430 if (TREE_CODE (arg) == TYPE_PACK_EXPANSION)
6431 arg = PACK_EXPANSION_PATTERN (arg);
6433 /* Deal with an injected-class-name used as a template template arg. */
6434 if (requires_tmpl_type && CLASS_TYPE_P (arg))
6436 tree t = maybe_get_template_decl_from_type_decl (TYPE_NAME (arg));
6437 if (TREE_CODE (t) == TEMPLATE_DECL)
6439 if (cxx_dialect >= cxx0x)
6440 /* OK under DR 1004. */;
6441 else if (complain & tf_warning_or_error)
6442 pedwarn (input_location, OPT_pedantic, "injected-class-name %qD"
6443 " used as template template argument", TYPE_NAME (arg));
6444 else if (flag_pedantic_errors)
6452 ((TREE_CODE (arg) == TEMPLATE_DECL
6453 && TREE_CODE (DECL_TEMPLATE_RESULT (arg)) == TYPE_DECL)
6454 || (requires_tmpl_type && TREE_CODE (arg) == TYPE_ARGUMENT_PACK)
6455 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
6456 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE);
6459 && (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
6460 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE))
6461 arg = TYPE_STUB_DECL (arg);
6463 is_type = TYPE_P (arg) || is_tmpl_type;
6465 if (requires_type && ! is_type && TREE_CODE (arg) == SCOPE_REF
6466 && TREE_CODE (TREE_OPERAND (arg, 0)) == TEMPLATE_TYPE_PARM)
6468 if (TREE_CODE (TREE_OPERAND (arg, 1)) == BIT_NOT_EXPR)
6470 if (complain & tf_error)
6471 error ("invalid use of destructor %qE as a type", orig_arg);
6472 return error_mark_node;
6475 permerror (input_location,
6476 "to refer to a type member of a template parameter, "
6477 "use %<typename %E%>", orig_arg);
6479 orig_arg = make_typename_type (TREE_OPERAND (arg, 0),
6480 TREE_OPERAND (arg, 1),
6482 complain & tf_error);
6486 if (is_type != requires_type)
6490 if (complain & tf_error)
6492 error ("type/value mismatch at argument %d in template "
6493 "parameter list for %qD",
6496 error (" expected a constant of type %qT, got %qT",
6498 (DECL_P (arg) ? DECL_NAME (arg) : orig_arg));
6499 else if (requires_tmpl_type)
6500 error (" expected a class template, got %qE", orig_arg);
6502 error (" expected a type, got %qE", orig_arg);
6505 return error_mark_node;
6507 if (is_tmpl_type ^ requires_tmpl_type)
6509 if (in_decl && (complain & tf_error))
6511 error ("type/value mismatch at argument %d in template "
6512 "parameter list for %qD",
6515 error (" expected a type, got %qT", DECL_NAME (arg));
6517 error (" expected a class template, got %qT", orig_arg);
6519 return error_mark_node;
6524 if (requires_tmpl_type)
6526 if (template_parameter_pack_p (parm) && ARGUMENT_PACK_P (orig_arg))
6528 else if (TREE_CODE (TREE_TYPE (arg)) == UNBOUND_CLASS_TEMPLATE)
6529 /* The number of argument required is not known yet.
6530 Just accept it for now. */
6531 val = TREE_TYPE (arg);
6534 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
6537 argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
6539 if (coerce_template_template_parms (parmparm, argparm,
6545 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6547 if (val != error_mark_node)
6549 if (DECL_TEMPLATE_TEMPLATE_PARM_P (val))
6550 val = TREE_TYPE (val);
6551 if (TREE_CODE (orig_arg) == TYPE_PACK_EXPANSION)
6552 val = make_pack_expansion (val);
6557 if (in_decl && (complain & tf_error))
6559 error ("type/value mismatch at argument %d in "
6560 "template parameter list for %qD",
6562 error (" expected a template of type %qD, got %qT",
6566 val = error_mark_node;
6572 /* We only form one instance of each template specialization.
6573 Therefore, if we use a non-canonical variant (i.e., a
6574 typedef), any future messages referring to the type will use
6575 the typedef, which is confusing if those future uses do not
6576 themselves also use the typedef. */
6578 val = canonicalize_type_argument (val, complain);
6582 tree t = tsubst (TREE_TYPE (parm), args, complain, in_decl);
6584 if (invalid_nontype_parm_type_p (t, complain))
6585 return error_mark_node;
6587 if (template_parameter_pack_p (parm) && ARGUMENT_PACK_P (orig_arg))
6589 if (same_type_p (t, TREE_TYPE (orig_arg)))
6593 /* Not sure if this is reachable, but it doesn't hurt
6595 error ("type mismatch in nontype parameter pack");
6596 val = error_mark_node;
6599 else if (!uses_template_parms (orig_arg) && !uses_template_parms (t))
6600 /* We used to call digest_init here. However, digest_init
6601 will report errors, which we don't want when complain
6602 is zero. More importantly, digest_init will try too
6603 hard to convert things: for example, `0' should not be
6604 converted to pointer type at this point according to
6605 the standard. Accepting this is not merely an
6606 extension, since deciding whether or not these
6607 conversions can occur is part of determining which
6608 function template to call, or whether a given explicit
6609 argument specification is valid. */
6610 val = convert_nontype_argument (t, orig_arg, complain);
6614 if (val == NULL_TREE)
6615 val = error_mark_node;
6616 else if (val == error_mark_node && (complain & tf_error))
6617 error ("could not convert template argument %qE to %qT", orig_arg, t);
6619 if (TREE_CODE (val) == SCOPE_REF)
6621 /* Strip typedefs from the SCOPE_REF. */
6622 tree type = canonicalize_type_argument (TREE_TYPE (val), complain);
6623 tree scope = canonicalize_type_argument (TREE_OPERAND (val, 0),
6625 val = build_qualified_name (type, scope, TREE_OPERAND (val, 1),
6626 QUALIFIED_NAME_IS_TEMPLATE (val));
6633 /* Coerces the remaining template arguments in INNER_ARGS (from
6634 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6635 Returns the coerced argument pack. PARM_IDX is the position of this
6636 parameter in the template parameter list. ARGS is the original
6637 template argument list. */
6639 coerce_template_parameter_pack (tree parms,
6647 tsubst_flags_t complain)
6649 tree parm = TREE_VEC_ELT (parms, parm_idx);
6650 int nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
6653 tree packed_types = NULL_TREE;
6655 if (arg_idx > nargs)
6658 packed_args = make_tree_vec (nargs - arg_idx);
6660 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL
6661 && uses_parameter_packs (TREE_TYPE (TREE_VALUE (parm))))
6663 /* When the template parameter is a non-type template
6664 parameter pack whose type uses parameter packs, we need
6665 to look at each of the template arguments
6666 separately. Build a vector of the types for these
6667 non-type template parameters in PACKED_TYPES. */
6669 = make_pack_expansion (TREE_TYPE (TREE_VALUE (parm)));
6670 packed_types = tsubst_pack_expansion (expansion, args,
6673 if (packed_types == error_mark_node)
6674 return error_mark_node;
6676 /* Check that we have the right number of arguments. */
6678 && !PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx))
6679 && nargs - arg_idx != TREE_VEC_LENGTH (packed_types))
6682 = TREE_VEC_LENGTH (parms) - 1 + TREE_VEC_LENGTH (packed_types);
6683 error ("wrong number of template arguments (%d, should be %d)",
6684 nargs, needed_parms);
6685 return error_mark_node;
6688 /* If we aren't able to check the actual arguments now
6689 (because they haven't been expanded yet), we can at least
6690 verify that all of the types used for the non-type
6691 template parameter pack are, in fact, valid for non-type
6692 template parameters. */
6694 && PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx)))
6696 int j, len = TREE_VEC_LENGTH (packed_types);
6697 for (j = 0; j < len; ++j)
6699 tree t = TREE_VEC_ELT (packed_types, j);
6700 if (invalid_nontype_parm_type_p (t, complain))
6701 return error_mark_node;
6706 /* Convert the remaining arguments, which will be a part of the
6707 parameter pack "parm". */
6708 for (; arg_idx < nargs; ++arg_idx)
6710 tree arg = TREE_VEC_ELT (inner_args, arg_idx);
6711 tree actual_parm = TREE_VALUE (parm);
6713 if (packed_types && !PACK_EXPANSION_P (arg))
6715 /* When we have a vector of types (corresponding to the
6716 non-type template parameter pack that uses parameter
6717 packs in its type, as mention above), and the
6718 argument is not an expansion (which expands to a
6719 currently unknown number of arguments), clone the
6720 parm and give it the next type in PACKED_TYPES. */
6721 actual_parm = copy_node (actual_parm);
6722 TREE_TYPE (actual_parm) =
6723 TREE_VEC_ELT (packed_types, arg_idx - parm_idx);
6726 if (arg != error_mark_node)
6727 arg = convert_template_argument (actual_parm,
6728 arg, new_args, complain, parm_idx,
6730 if (arg == error_mark_node)
6732 TREE_VEC_ELT (packed_args, arg_idx - parm_idx) = arg;
6735 if (TREE_CODE (TREE_VALUE (parm)) == TYPE_DECL
6736 || TREE_CODE (TREE_VALUE (parm)) == TEMPLATE_DECL)
6737 argument_pack = cxx_make_type (TYPE_ARGUMENT_PACK);
6740 argument_pack = make_node (NONTYPE_ARGUMENT_PACK);
6741 TREE_TYPE (argument_pack)
6742 = tsubst (TREE_TYPE (TREE_VALUE (parm)), new_args, complain, in_decl);
6743 TREE_CONSTANT (argument_pack) = 1;
6746 SET_ARGUMENT_PACK_ARGS (argument_pack, packed_args);
6747 #ifdef ENABLE_CHECKING
6748 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (packed_args,
6749 TREE_VEC_LENGTH (packed_args));
6751 return argument_pack;
6754 /* Returns true if the template argument vector ARGS contains
6755 any pack expansions, false otherwise. */
6758 any_pack_expanson_args_p (tree args)
6762 for (i = 0; i < TREE_VEC_LENGTH (args); ++i)
6763 if (PACK_EXPANSION_P (TREE_VEC_ELT (args, i)))
6768 /* Convert all template arguments to their appropriate types, and
6769 return a vector containing the innermost resulting template
6770 arguments. If any error occurs, return error_mark_node. Error and
6771 warning messages are issued under control of COMPLAIN.
6773 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6774 for arguments not specified in ARGS. Otherwise, if
6775 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6776 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6777 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6781 coerce_template_parms (tree parms,
6784 tsubst_flags_t complain,
6785 bool require_all_args,
6786 bool use_default_args)
6788 int nparms, nargs, parm_idx, arg_idx, lost = 0;
6791 tree new_inner_args;
6792 int saved_unevaluated_operand;
6793 int saved_inhibit_evaluation_warnings;
6795 /* When used as a boolean value, indicates whether this is a
6796 variadic template parameter list. Since it's an int, we can also
6797 subtract it from nparms to get the number of non-variadic
6800 int post_variadic_parms = 0;
6802 if (args == error_mark_node)
6803 return error_mark_node;
6805 nparms = TREE_VEC_LENGTH (parms);
6807 /* Determine if there are any parameter packs. */
6808 for (parm_idx = 0; parm_idx < nparms; ++parm_idx)
6810 tree tparm = TREE_VALUE (TREE_VEC_ELT (parms, parm_idx));
6812 ++post_variadic_parms;
6813 if (template_parameter_pack_p (tparm))
6817 inner_args = INNERMOST_TEMPLATE_ARGS (args);
6818 /* If there are no parameters that follow a parameter pack, we need to
6819 expand any argument packs so that we can deduce a parameter pack from
6820 some non-packed args followed by an argument pack, as in variadic85.C.
6821 If there are such parameters, we need to leave argument packs intact
6822 so the arguments are assigned properly. This can happen when dealing
6823 with a nested class inside a partial specialization of a class
6824 template, as in variadic92.C, or when deducing a template parameter pack
6825 from a sub-declarator, as in variadic114.C. */
6826 if (!post_variadic_parms)
6827 inner_args = expand_template_argument_pack (inner_args);
6829 nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
6830 if ((nargs > nparms && !variadic_p)
6831 || (nargs < nparms - variadic_p
6833 && !any_pack_expanson_args_p (inner_args)
6834 && (!use_default_args
6835 || (TREE_VEC_ELT (parms, nargs) != error_mark_node
6836 && !TREE_PURPOSE (TREE_VEC_ELT (parms, nargs))))))
6838 if (complain & tf_error)
6842 nparms -= variadic_p;
6843 error ("wrong number of template arguments "
6844 "(%d, should be %d or more)", nargs, nparms);
6847 error ("wrong number of template arguments "
6848 "(%d, should be %d)", nargs, nparms);
6851 error ("provided for %q+D", in_decl);
6854 return error_mark_node;
6857 /* We need to evaluate the template arguments, even though this
6858 template-id may be nested within a "sizeof". */
6859 saved_unevaluated_operand = cp_unevaluated_operand;
6860 cp_unevaluated_operand = 0;
6861 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
6862 c_inhibit_evaluation_warnings = 0;
6863 new_inner_args = make_tree_vec (nparms);
6864 new_args = add_outermost_template_args (args, new_inner_args);
6865 for (parm_idx = 0, arg_idx = 0; parm_idx < nparms; parm_idx++, arg_idx++)
6870 /* Get the Ith template parameter. */
6871 parm = TREE_VEC_ELT (parms, parm_idx);
6873 if (parm == error_mark_node)
6875 TREE_VEC_ELT (new_inner_args, arg_idx) = error_mark_node;
6879 /* Calculate the next argument. */
6880 if (arg_idx < nargs)
6881 arg = TREE_VEC_ELT (inner_args, arg_idx);
6885 if (template_parameter_pack_p (TREE_VALUE (parm))
6886 && !(arg && ARGUMENT_PACK_P (arg)))
6888 /* All remaining arguments will be placed in the
6889 template parameter pack PARM. */
6890 arg = coerce_template_parameter_pack (parms, parm_idx, args,
6891 inner_args, arg_idx,
6895 /* Store this argument. */
6896 if (arg == error_mark_node)
6898 TREE_VEC_ELT (new_inner_args, parm_idx) = arg;
6900 /* We are done with all of the arguments. */
6907 if (PACK_EXPANSION_P (arg))
6909 /* We don't know how many args we have yet, just
6910 use the unconverted ones for now. */
6911 new_inner_args = inner_args;
6915 else if (require_all_args)
6917 /* There must be a default arg in this case. */
6918 arg = tsubst_template_arg (TREE_PURPOSE (parm), new_args,
6920 /* The position of the first default template argument,
6921 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6923 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args))
6924 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args, arg_idx);
6929 if (arg == error_mark_node)
6931 if (complain & tf_error)
6932 error ("template argument %d is invalid", arg_idx + 1);
6935 /* This only occurs if there was an error in the template
6936 parameter list itself (which we would already have
6937 reported) that we are trying to recover from, e.g., a class
6938 template with a parameter list such as
6939 template<typename..., typename>. */
6942 arg = convert_template_argument (TREE_VALUE (parm),
6943 arg, new_args, complain,
6946 if (arg == error_mark_node)
6948 TREE_VEC_ELT (new_inner_args, arg_idx) = arg;
6950 cp_unevaluated_operand = saved_unevaluated_operand;
6951 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
6954 return error_mark_node;
6956 #ifdef ENABLE_CHECKING
6957 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args))
6958 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args,
6959 TREE_VEC_LENGTH (new_inner_args));
6962 return new_inner_args;
6965 /* Returns 1 if template args OT and NT are equivalent. */
6968 template_args_equal (tree ot, tree nt)
6972 if (nt == NULL_TREE || ot == NULL_TREE)
6975 if (TREE_CODE (nt) == TREE_VEC)
6976 /* For member templates */
6977 return TREE_CODE (ot) == TREE_VEC && comp_template_args (ot, nt);
6978 else if (PACK_EXPANSION_P (ot))
6979 return (PACK_EXPANSION_P (nt)
6980 && template_args_equal (PACK_EXPANSION_PATTERN (ot),
6981 PACK_EXPANSION_PATTERN (nt))
6982 && template_args_equal (PACK_EXPANSION_EXTRA_ARGS (ot),
6983 PACK_EXPANSION_EXTRA_ARGS (nt)));
6984 else if (ARGUMENT_PACK_P (ot))
6989 if (!ARGUMENT_PACK_P (nt))
6992 opack = ARGUMENT_PACK_ARGS (ot);
6993 npack = ARGUMENT_PACK_ARGS (nt);
6994 len = TREE_VEC_LENGTH (opack);
6995 if (TREE_VEC_LENGTH (npack) != len)
6997 for (i = 0; i < len; ++i)
6998 if (!template_args_equal (TREE_VEC_ELT (opack, i),
6999 TREE_VEC_ELT (npack, i)))
7003 else if (ot && TREE_CODE (ot) == ARGUMENT_PACK_SELECT)
7005 /* We get here probably because we are in the middle of substituting
7006 into the pattern of a pack expansion. In that case the
7007 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
7008 interested in. So we want to use the initial pack argument for
7010 ot = ARGUMENT_PACK_SELECT_FROM_PACK (ot);
7011 if (nt && TREE_CODE (nt) == ARGUMENT_PACK_SELECT)
7012 nt = ARGUMENT_PACK_SELECT_FROM_PACK (nt);
7013 return template_args_equal (ot, nt);
7015 else if (TYPE_P (nt))
7016 return TYPE_P (ot) && same_type_p (ot, nt);
7017 else if (TREE_CODE (ot) == TREE_VEC || TYPE_P (ot))
7020 return cp_tree_equal (ot, nt);
7023 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
7024 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
7025 NEWARG_PTR with the offending arguments if they are non-NULL. */
7028 comp_template_args_with_info (tree oldargs, tree newargs,
7029 tree *oldarg_ptr, tree *newarg_ptr)
7033 if (oldargs == newargs)
7036 if (!oldargs || !newargs)
7039 if (TREE_VEC_LENGTH (oldargs) != TREE_VEC_LENGTH (newargs))
7042 for (i = 0; i < TREE_VEC_LENGTH (oldargs); ++i)
7044 tree nt = TREE_VEC_ELT (newargs, i);
7045 tree ot = TREE_VEC_ELT (oldargs, i);
7047 if (! template_args_equal (ot, nt))
7049 if (oldarg_ptr != NULL)
7051 if (newarg_ptr != NULL)
7059 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
7060 of template arguments. Returns 0 otherwise. */
7063 comp_template_args (tree oldargs, tree newargs)
7065 return comp_template_args_with_info (oldargs, newargs, NULL, NULL);
7069 add_pending_template (tree d)
7071 tree ti = (TYPE_P (d)
7072 ? CLASSTYPE_TEMPLATE_INFO (d)
7073 : DECL_TEMPLATE_INFO (d));
7074 struct pending_template *pt;
7077 if (TI_PENDING_TEMPLATE_FLAG (ti))
7080 /* We are called both from instantiate_decl, where we've already had a
7081 tinst_level pushed, and instantiate_template, where we haven't.
7083 level = !current_tinst_level || current_tinst_level->decl != d;
7086 push_tinst_level (d);
7088 pt = ggc_alloc_pending_template ();
7090 pt->tinst = current_tinst_level;
7091 if (last_pending_template)
7092 last_pending_template->next = pt;
7094 pending_templates = pt;
7096 last_pending_template = pt;
7098 TI_PENDING_TEMPLATE_FLAG (ti) = 1;
7105 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
7106 ARGLIST. Valid choices for FNS are given in the cp-tree.def
7107 documentation for TEMPLATE_ID_EXPR. */
7110 lookup_template_function (tree fns, tree arglist)
7114 if (fns == error_mark_node || arglist == error_mark_node)
7115 return error_mark_node;
7117 gcc_assert (!arglist || TREE_CODE (arglist) == TREE_VEC);
7119 if (!is_overloaded_fn (fns) && TREE_CODE (fns) != IDENTIFIER_NODE)
7121 error ("%q#D is not a function template", fns);
7122 return error_mark_node;
7125 if (BASELINK_P (fns))
7127 BASELINK_FUNCTIONS (fns) = build2 (TEMPLATE_ID_EXPR,
7129 BASELINK_FUNCTIONS (fns),
7134 type = TREE_TYPE (fns);
7135 if (TREE_CODE (fns) == OVERLOAD || !type)
7136 type = unknown_type_node;
7138 return build2 (TEMPLATE_ID_EXPR, type, fns, arglist);
7141 /* Within the scope of a template class S<T>, the name S gets bound
7142 (in build_self_reference) to a TYPE_DECL for the class, not a
7143 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
7144 or one of its enclosing classes, and that type is a template,
7145 return the associated TEMPLATE_DECL. Otherwise, the original
7148 Also handle the case when DECL is a TREE_LIST of ambiguous
7149 injected-class-names from different bases. */
7152 maybe_get_template_decl_from_type_decl (tree decl)
7154 if (decl == NULL_TREE)
7157 /* DR 176: A lookup that finds an injected-class-name (10.2
7158 [class.member.lookup]) can result in an ambiguity in certain cases
7159 (for example, if it is found in more than one base class). If all of
7160 the injected-class-names that are found refer to specializations of
7161 the same class template, and if the name is followed by a
7162 template-argument-list, the reference refers to the class template
7163 itself and not a specialization thereof, and is not ambiguous. */
7164 if (TREE_CODE (decl) == TREE_LIST)
7166 tree t, tmpl = NULL_TREE;
7167 for (t = decl; t; t = TREE_CHAIN (t))
7169 tree elt = maybe_get_template_decl_from_type_decl (TREE_VALUE (t));
7172 else if (tmpl != elt)
7175 if (tmpl && t == NULL_TREE)
7181 return (decl != NULL_TREE
7182 && DECL_SELF_REFERENCE_P (decl)
7183 && CLASSTYPE_TEMPLATE_INFO (TREE_TYPE (decl)))
7184 ? CLASSTYPE_TI_TEMPLATE (TREE_TYPE (decl)) : decl;
7187 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
7188 parameters, find the desired type.
7190 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
7192 IN_DECL, if non-NULL, is the template declaration we are trying to
7195 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
7196 the class we are looking up.
7198 Issue error and warning messages under control of COMPLAIN.
7200 If the template class is really a local class in a template
7201 function, then the FUNCTION_CONTEXT is the function in which it is
7204 ??? Note that this function is currently called *twice* for each
7205 template-id: the first time from the parser, while creating the
7206 incomplete type (finish_template_type), and the second type during the
7207 real instantiation (instantiate_template_class). This is surely something
7208 that we want to avoid. It also causes some problems with argument
7209 coercion (see convert_nontype_argument for more information on this). */
7212 lookup_template_class_1 (tree d1, tree arglist, tree in_decl, tree context,
7213 int entering_scope, tsubst_flags_t complain)
7215 tree templ = NULL_TREE, parmlist;
7222 if (TREE_CODE (d1) == IDENTIFIER_NODE)
7224 tree value = innermost_non_namespace_value (d1);
7225 if (value && DECL_TEMPLATE_TEMPLATE_PARM_P (value))
7230 push_decl_namespace (context);
7231 templ = lookup_name (d1);
7232 templ = maybe_get_template_decl_from_type_decl (templ);
7234 pop_decl_namespace ();
7237 context = DECL_CONTEXT (templ);
7239 else if (TREE_CODE (d1) == TYPE_DECL && MAYBE_CLASS_TYPE_P (TREE_TYPE (d1)))
7241 tree type = TREE_TYPE (d1);
7243 /* If we are declaring a constructor, say A<T>::A<T>, we will get
7244 an implicit typename for the second A. Deal with it. */
7245 if (TREE_CODE (type) == TYPENAME_TYPE && TREE_TYPE (type))
7246 type = TREE_TYPE (type);
7248 if (CLASSTYPE_TEMPLATE_INFO (type))
7250 templ = CLASSTYPE_TI_TEMPLATE (type);
7251 d1 = DECL_NAME (templ);
7254 else if (TREE_CODE (d1) == ENUMERAL_TYPE
7255 || (TYPE_P (d1) && MAYBE_CLASS_TYPE_P (d1)))
7257 templ = TYPE_TI_TEMPLATE (d1);
7258 d1 = DECL_NAME (templ);
7260 else if (TREE_CODE (d1) == TEMPLATE_DECL
7261 && DECL_TEMPLATE_RESULT (d1)
7262 && TREE_CODE (DECL_TEMPLATE_RESULT (d1)) == TYPE_DECL)
7265 d1 = DECL_NAME (templ);
7266 context = DECL_CONTEXT (templ);
7269 /* Issue an error message if we didn't find a template. */
7272 if (complain & tf_error)
7273 error ("%qT is not a template", d1);
7274 return error_mark_node;
7277 if (TREE_CODE (templ) != TEMPLATE_DECL
7278 /* Make sure it's a user visible template, if it was named by
7280 || ((complain & tf_user) && !DECL_TEMPLATE_PARM_P (templ)
7281 && !PRIMARY_TEMPLATE_P (templ)))
7283 if (complain & tf_error)
7285 error ("non-template type %qT used as a template", d1);
7287 error ("for template declaration %q+D", in_decl);
7289 return error_mark_node;
7292 complain &= ~tf_user;
7294 if (DECL_TEMPLATE_TEMPLATE_PARM_P (templ))
7296 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
7297 template arguments */
7303 parmlist = DECL_INNERMOST_TEMPLATE_PARMS (templ);
7305 /* Consider an example where a template template parameter declared as
7307 template <class T, class U = std::allocator<T> > class TT
7309 The template parameter level of T and U are one level larger than
7310 of TT. To proper process the default argument of U, say when an
7311 instantiation `TT<int>' is seen, we need to build the full
7312 arguments containing {int} as the innermost level. Outer levels,
7313 available when not appearing as default template argument, can be
7314 obtained from the arguments of the enclosing template.
7316 Suppose that TT is later substituted with std::vector. The above
7317 instantiation is `TT<int, std::allocator<T> >' with TT at
7318 level 1, and T at level 2, while the template arguments at level 1
7319 becomes {std::vector} and the inner level 2 is {int}. */
7321 outer = DECL_CONTEXT (templ);
7323 outer = TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (outer)));
7324 else if (current_template_parms)
7325 /* This is an argument of the current template, so we haven't set
7326 DECL_CONTEXT yet. */
7327 outer = current_template_args ();
7330 arglist = add_to_template_args (outer, arglist);
7332 arglist2 = coerce_template_parms (parmlist, arglist, templ,
7334 /*require_all_args=*/true,
7335 /*use_default_args=*/true);
7336 if (arglist2 == error_mark_node
7337 || (!uses_template_parms (arglist2)
7338 && check_instantiated_args (templ, arglist2, complain)))
7339 return error_mark_node;
7341 parm = bind_template_template_parm (TREE_TYPE (templ), arglist2);
7346 tree template_type = TREE_TYPE (templ);
7349 tree found = NULL_TREE;
7352 int is_dependent_type;
7353 int use_partial_inst_tmpl = false;
7355 if (template_type == error_mark_node)
7356 /* An error occured while building the template TEMPL, and a
7357 diagnostic has most certainly been emitted for that
7358 already. Let's propagate that error. */
7359 return error_mark_node;
7361 gen_tmpl = most_general_template (templ);
7362 parmlist = DECL_TEMPLATE_PARMS (gen_tmpl);
7363 parm_depth = TMPL_PARMS_DEPTH (parmlist);
7364 arg_depth = TMPL_ARGS_DEPTH (arglist);
7366 if (arg_depth == 1 && parm_depth > 1)
7368 /* We've been given an incomplete set of template arguments.
7371 template <class T> struct S1 {
7372 template <class U> struct S2 {};
7373 template <class U> struct S2<U*> {};
7376 we will be called with an ARGLIST of `U*', but the
7377 TEMPLATE will be `template <class T> template
7378 <class U> struct S1<T>::S2'. We must fill in the missing
7381 = add_outermost_template_args (TYPE_TI_ARGS (TREE_TYPE (templ)),
7383 arg_depth = TMPL_ARGS_DEPTH (arglist);
7386 /* Now we should have enough arguments. */
7387 gcc_assert (parm_depth == arg_depth);
7389 /* From here on, we're only interested in the most general
7392 /* Calculate the BOUND_ARGS. These will be the args that are
7393 actually tsubst'd into the definition to create the
7397 /* We have multiple levels of arguments to coerce, at once. */
7399 int saved_depth = TMPL_ARGS_DEPTH (arglist);
7401 tree bound_args = make_tree_vec (parm_depth);
7403 for (i = saved_depth,
7404 t = DECL_TEMPLATE_PARMS (gen_tmpl);
7405 i > 0 && t != NULL_TREE;
7406 --i, t = TREE_CHAIN (t))
7409 if (i == saved_depth)
7410 a = coerce_template_parms (TREE_VALUE (t),
7413 /*require_all_args=*/true,
7414 /*use_default_args=*/true);
7416 /* Outer levels should have already been coerced. */
7417 a = TMPL_ARGS_LEVEL (arglist, i);
7419 /* Don't process further if one of the levels fails. */
7420 if (a == error_mark_node)
7422 /* Restore the ARGLIST to its full size. */
7423 TREE_VEC_LENGTH (arglist) = saved_depth;
7424 return error_mark_node;
7427 SET_TMPL_ARGS_LEVEL (bound_args, i, a);
7429 /* We temporarily reduce the length of the ARGLIST so
7430 that coerce_template_parms will see only the arguments
7431 corresponding to the template parameters it is
7433 TREE_VEC_LENGTH (arglist)--;
7436 /* Restore the ARGLIST to its full size. */
7437 TREE_VEC_LENGTH (arglist) = saved_depth;
7439 arglist = bound_args;
7443 = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parmlist),
7444 INNERMOST_TEMPLATE_ARGS (arglist),
7447 /*require_all_args=*/true,
7448 /*use_default_args=*/true);
7450 if (arglist == error_mark_node)
7451 /* We were unable to bind the arguments. */
7452 return error_mark_node;
7454 /* In the scope of a template class, explicit references to the
7455 template class refer to the type of the template, not any
7456 instantiation of it. For example, in:
7458 template <class T> class C { void f(C<T>); }
7460 the `C<T>' is just the same as `C'. Outside of the
7461 class, however, such a reference is an instantiation. */
7463 || !PRIMARY_TEMPLATE_P (gen_tmpl)
7464 || currently_open_class (template_type))
7465 /* comp_template_args is expensive, check it last. */
7466 && comp_template_args (TYPE_TI_ARGS (template_type),
7468 return template_type;
7470 /* If we already have this specialization, return it. */
7471 elt.tmpl = gen_tmpl;
7473 hash = hash_specialization (&elt);
7474 entry = (spec_entry *) htab_find_with_hash (type_specializations,
7480 is_dependent_type = uses_template_parms (arglist);
7482 /* If the deduced arguments are invalid, then the binding
7484 if (!is_dependent_type
7485 && check_instantiated_args (gen_tmpl,
7486 INNERMOST_TEMPLATE_ARGS (arglist),
7488 return error_mark_node;
7490 if (!is_dependent_type
7491 && !PRIMARY_TEMPLATE_P (gen_tmpl)
7492 && !LAMBDA_TYPE_P (TREE_TYPE (gen_tmpl))
7493 && TREE_CODE (CP_DECL_CONTEXT (gen_tmpl)) == NAMESPACE_DECL)
7495 found = xref_tag_from_type (TREE_TYPE (gen_tmpl),
7496 DECL_NAME (gen_tmpl),
7497 /*tag_scope=*/ts_global);
7501 context = tsubst (DECL_CONTEXT (gen_tmpl), arglist,
7503 if (context == error_mark_node)
7504 return error_mark_node;
7507 context = global_namespace;
7509 /* Create the type. */
7510 if (TREE_CODE (template_type) == ENUMERAL_TYPE)
7512 if (!is_dependent_type)
7514 set_current_access_from_decl (TYPE_NAME (template_type));
7515 t = start_enum (TYPE_IDENTIFIER (template_type), NULL_TREE,
7516 tsubst (ENUM_UNDERLYING_TYPE (template_type),
7517 arglist, complain, in_decl),
7518 SCOPED_ENUM_P (template_type), NULL);
7522 /* We don't want to call start_enum for this type, since
7523 the values for the enumeration constants may involve
7524 template parameters. And, no one should be interested
7525 in the enumeration constants for such a type. */
7526 t = cxx_make_type (ENUMERAL_TYPE);
7527 SET_SCOPED_ENUM_P (t, SCOPED_ENUM_P (template_type));
7529 SET_OPAQUE_ENUM_P (t, OPAQUE_ENUM_P (template_type));
7530 ENUM_FIXED_UNDERLYING_TYPE_P (t)
7531 = ENUM_FIXED_UNDERLYING_TYPE_P (template_type);
7533 else if (DECL_ALIAS_TEMPLATE_P (gen_tmpl))
7535 /* The user referred to a specialization of an alias
7536 template represented by GEN_TMPL.
7538 [temp.alias]/2 says:
7540 When a template-id refers to the specialization of an
7541 alias template, it is equivalent to the associated
7542 type obtained by substitution of its
7543 template-arguments for the template-parameters in the
7544 type-id of the alias template. */
7546 t = tsubst (TREE_TYPE (gen_tmpl), arglist, complain, in_decl);
7547 /* Note that the call above (by indirectly calling
7548 register_specialization in tsubst_decl) registers the
7549 TYPE_DECL representing the specialization of the alias
7550 template. So next time someone substitutes ARGLIST for
7551 the template parms into the alias template (GEN_TMPL),
7552 she'll get that TYPE_DECL back. */
7554 if (t == error_mark_node)
7557 else if (CLASS_TYPE_P (template_type))
7559 t = make_class_type (TREE_CODE (template_type));
7560 CLASSTYPE_DECLARED_CLASS (t)
7561 = CLASSTYPE_DECLARED_CLASS (template_type);
7562 SET_CLASSTYPE_IMPLICIT_INSTANTIATION (t);
7563 TYPE_FOR_JAVA (t) = TYPE_FOR_JAVA (template_type);
7565 /* A local class. Make sure the decl gets registered properly. */
7566 if (context == current_function_decl)
7567 pushtag (DECL_NAME (gen_tmpl), t, /*tag_scope=*/ts_global);
7569 if (comp_template_args (CLASSTYPE_TI_ARGS (template_type), arglist))
7570 /* This instantiation is another name for the primary
7571 template type. Set the TYPE_CANONICAL field
7573 TYPE_CANONICAL (t) = template_type;
7574 else if (any_template_arguments_need_structural_equality_p (arglist))
7575 /* Some of the template arguments require structural
7576 equality testing, so this template class requires
7577 structural equality testing. */
7578 SET_TYPE_STRUCTURAL_EQUALITY (t);
7583 /* If we called start_enum or pushtag above, this information
7584 will already be set up. */
7587 TYPE_CONTEXT (t) = FROB_CONTEXT (context);
7589 type_decl = create_implicit_typedef (DECL_NAME (gen_tmpl), t);
7590 DECL_CONTEXT (type_decl) = TYPE_CONTEXT (t);
7591 DECL_SOURCE_LOCATION (type_decl)
7592 = DECL_SOURCE_LOCATION (TYPE_STUB_DECL (template_type));
7595 type_decl = TYPE_NAME (t);
7597 if (CLASS_TYPE_P (template_type))
7599 TREE_PRIVATE (type_decl)
7600 = TREE_PRIVATE (TYPE_STUB_DECL (template_type));
7601 TREE_PROTECTED (type_decl)
7602 = TREE_PROTECTED (TYPE_STUB_DECL (template_type));
7603 if (CLASSTYPE_VISIBILITY_SPECIFIED (template_type))
7605 DECL_VISIBILITY_SPECIFIED (type_decl) = 1;
7606 DECL_VISIBILITY (type_decl) = CLASSTYPE_VISIBILITY (template_type);
7610 /* Let's consider the explicit specialization of a member
7611 of a class template specialization that is implicitely instantiated,
7616 template<class U> struct M {}; //#0
7621 struct S<int>::M<char> //#1
7625 [temp.expl.spec]/4 says this is valid.
7627 In this case, when we write:
7630 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7633 When we encounter #1, we want to store the partial instantiation
7634 of M (template<class T> S<int>::M<T>) in it's CLASSTYPE_TI_TEMPLATE.
7636 For all cases other than this "explicit specialization of member of a
7637 class template", we just want to store the most general template into
7638 the CLASSTYPE_TI_TEMPLATE of M.
7640 This case of "explicit specialization of member of a class template"
7642 1/ the enclosing class is an instantiation of, and therefore not
7643 the same as, the context of the most general template, and
7644 2/ we aren't looking at the partial instantiation itself, i.e.
7645 the innermost arguments are not the same as the innermost parms of
7646 the most general template.
7648 So it's only when 1/ and 2/ happens that we want to use the partial
7649 instantiation of the member template in lieu of its most general
7652 if (PRIMARY_TEMPLATE_P (gen_tmpl)
7653 && TMPL_ARGS_HAVE_MULTIPLE_LEVELS (arglist)
7654 /* the enclosing class must be an instantiation... */
7655 && CLASS_TYPE_P (context)
7656 && !same_type_p (context, DECL_CONTEXT (gen_tmpl)))
7658 tree partial_inst_args;
7659 TREE_VEC_LENGTH (arglist)--;
7660 ++processing_template_decl;
7662 tsubst (INNERMOST_TEMPLATE_ARGS
7663 (TYPE_TI_ARGS (TREE_TYPE (gen_tmpl))),
7664 arglist, complain, NULL_TREE);
7665 --processing_template_decl;
7666 TREE_VEC_LENGTH (arglist)++;
7667 use_partial_inst_tmpl =
7668 /*...and we must not be looking at the partial instantiation
7670 !comp_template_args (INNERMOST_TEMPLATE_ARGS (arglist),
7674 if (!use_partial_inst_tmpl)
7675 /* This case is easy; there are no member templates involved. */
7679 /* This is a full instantiation of a member template. Find
7680 the partial instantiation of which this is an instance. */
7682 /* Temporarily reduce by one the number of levels in the ARGLIST
7683 so as to avoid comparing the last set of arguments. */
7684 TREE_VEC_LENGTH (arglist)--;
7685 found = tsubst (gen_tmpl, arglist, complain, NULL_TREE);
7686 TREE_VEC_LENGTH (arglist)++;
7687 /* FOUND is either a proper class type, or an alias
7688 template specialization. In the later case, it's a
7689 TYPE_DECL, resulting from the substituting of arguments
7690 for parameters in the TYPE_DECL of the alias template
7691 done earlier. So be careful while getting the template
7693 found = TREE_CODE (found) == TYPE_DECL
7694 ? TYPE_TI_TEMPLATE (TREE_TYPE (found))
7695 : CLASSTYPE_TI_TEMPLATE (found);
7698 SET_TYPE_TEMPLATE_INFO (t, build_template_info (found, arglist));
7701 slot = htab_find_slot_with_hash (type_specializations,
7702 &elt, hash, INSERT);
7703 entry = ggc_alloc_spec_entry ();
7707 /* Note this use of the partial instantiation so we can check it
7708 later in maybe_process_partial_specialization. */
7709 DECL_TEMPLATE_INSTANTIATIONS (templ)
7710 = tree_cons (arglist, t,
7711 DECL_TEMPLATE_INSTANTIATIONS (templ));
7713 if (TREE_CODE (t) == ENUMERAL_TYPE && !is_dependent_type)
7714 /* Now that the type has been registered on the instantiations
7715 list, we set up the enumerators. Because the enumeration
7716 constants may involve the enumeration type itself, we make
7717 sure to register the type first, and then create the
7718 constants. That way, doing tsubst_expr for the enumeration
7719 constants won't result in recursive calls here; we'll find
7720 the instantiation and exit above. */
7721 tsubst_enum (template_type, t, arglist);
7723 if (CLASS_TYPE_P (template_type) && is_dependent_type)
7724 /* If the type makes use of template parameters, the
7725 code that generates debugging information will crash. */
7726 DECL_IGNORED_P (TYPE_STUB_DECL (t)) = 1;
7728 /* Possibly limit visibility based on template args. */
7729 TREE_PUBLIC (type_decl) = 1;
7730 determine_visibility (type_decl);
7736 /* Wrapper for lookup_template_class_1. */
7739 lookup_template_class (tree d1, tree arglist, tree in_decl, tree context,
7740 int entering_scope, tsubst_flags_t complain)
7743 timevar_push (TV_TEMPLATE_INST);
7744 ret = lookup_template_class_1 (d1, arglist, in_decl, context,
7745 entering_scope, complain);
7746 timevar_pop (TV_TEMPLATE_INST);
7754 /* True when we should also visit template parameters that occur in
7755 non-deduced contexts. */
7756 bool include_nondeduced_p;
7757 struct pointer_set_t *visited;
7760 /* Called from for_each_template_parm via walk_tree. */
7763 for_each_template_parm_r (tree *tp, int *walk_subtrees, void *d)
7766 struct pair_fn_data *pfd = (struct pair_fn_data *) d;
7767 tree_fn_t fn = pfd->fn;
7768 void *data = pfd->data;
7771 && (pfd->include_nondeduced_p || TREE_CODE (t) != TYPENAME_TYPE)
7772 && for_each_template_parm (TYPE_CONTEXT (t), fn, data, pfd->visited,
7773 pfd->include_nondeduced_p))
7774 return error_mark_node;
7776 switch (TREE_CODE (t))
7779 if (TYPE_PTRMEMFUNC_P (t))
7785 if (!TYPE_TEMPLATE_INFO (t))
7787 else if (for_each_template_parm (TI_ARGS (TYPE_TEMPLATE_INFO (t)),
7788 fn, data, pfd->visited,
7789 pfd->include_nondeduced_p))
7790 return error_mark_node;
7794 if (for_each_template_parm (TYPE_MIN_VALUE (t),
7795 fn, data, pfd->visited,
7796 pfd->include_nondeduced_p)
7797 || for_each_template_parm (TYPE_MAX_VALUE (t),
7798 fn, data, pfd->visited,
7799 pfd->include_nondeduced_p))
7800 return error_mark_node;
7804 /* Since we're not going to walk subtrees, we have to do this
7806 if (for_each_template_parm (TYPE_METHOD_BASETYPE (t), fn, data,
7807 pfd->visited, pfd->include_nondeduced_p))
7808 return error_mark_node;
7812 /* Check the return type. */
7813 if (for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
7814 pfd->include_nondeduced_p))
7815 return error_mark_node;
7817 /* Check the parameter types. Since default arguments are not
7818 instantiated until they are needed, the TYPE_ARG_TYPES may
7819 contain expressions that involve template parameters. But,
7820 no-one should be looking at them yet. And, once they're
7821 instantiated, they don't contain template parameters, so
7822 there's no point in looking at them then, either. */
7826 for (parm = TYPE_ARG_TYPES (t); parm; parm = TREE_CHAIN (parm))
7827 if (for_each_template_parm (TREE_VALUE (parm), fn, data,
7828 pfd->visited, pfd->include_nondeduced_p))
7829 return error_mark_node;
7831 /* Since we've already handled the TYPE_ARG_TYPES, we don't
7832 want walk_tree walking into them itself. */
7838 case UNDERLYING_TYPE:
7839 if (pfd->include_nondeduced_p
7840 && for_each_template_parm (TYPE_FIELDS (t), fn, data,
7842 pfd->include_nondeduced_p))
7843 return error_mark_node;
7848 if (DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t)
7849 && for_each_template_parm (DECL_TI_ARGS (t), fn, data,
7850 pfd->visited, pfd->include_nondeduced_p))
7851 return error_mark_node;
7856 if (TREE_CODE (t) == CONST_DECL && DECL_TEMPLATE_PARM_P (t)
7857 && for_each_template_parm (DECL_INITIAL (t), fn, data,
7858 pfd->visited, pfd->include_nondeduced_p))
7859 return error_mark_node;
7860 if (DECL_CONTEXT (t)
7861 && pfd->include_nondeduced_p
7862 && for_each_template_parm (DECL_CONTEXT (t), fn, data,
7863 pfd->visited, pfd->include_nondeduced_p))
7864 return error_mark_node;
7867 case BOUND_TEMPLATE_TEMPLATE_PARM:
7868 /* Record template parameters such as `T' inside `TT<T>'. */
7869 if (for_each_template_parm (TYPE_TI_ARGS (t), fn, data, pfd->visited,
7870 pfd->include_nondeduced_p))
7871 return error_mark_node;
7874 case TEMPLATE_TEMPLATE_PARM:
7875 case TEMPLATE_TYPE_PARM:
7876 case TEMPLATE_PARM_INDEX:
7877 if (fn && (*fn)(t, data))
7878 return error_mark_node;
7880 return error_mark_node;
7884 /* A template template parameter is encountered. */
7885 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t)
7886 && for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
7887 pfd->include_nondeduced_p))
7888 return error_mark_node;
7890 /* Already substituted template template parameter */
7896 || for_each_template_parm (TYPENAME_TYPE_FULLNAME (t), fn,
7898 pfd->include_nondeduced_p))
7899 return error_mark_node;
7903 if (TREE_TYPE (t) && TYPE_PTRMEMFUNC_P (TREE_TYPE (t))
7904 && pfd->include_nondeduced_p
7905 && for_each_template_parm (TYPE_PTRMEMFUNC_FN_TYPE
7906 (TREE_TYPE (t)), fn, data,
7907 pfd->visited, pfd->include_nondeduced_p))
7908 return error_mark_node;
7913 /* If there's no type, then this thing must be some expression
7914 involving template parameters. */
7915 if (!fn && !TREE_TYPE (t))
7916 return error_mark_node;
7921 case IMPLICIT_CONV_EXPR:
7922 case REINTERPRET_CAST_EXPR:
7923 case CONST_CAST_EXPR:
7924 case STATIC_CAST_EXPR:
7925 case DYNAMIC_CAST_EXPR:
7929 case PSEUDO_DTOR_EXPR:
7931 return error_mark_node;
7938 /* We didn't find any template parameters we liked. */
7942 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
7943 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
7944 call FN with the parameter and the DATA.
7945 If FN returns nonzero, the iteration is terminated, and
7946 for_each_template_parm returns 1. Otherwise, the iteration
7947 continues. If FN never returns a nonzero value, the value
7948 returned by for_each_template_parm is 0. If FN is NULL, it is
7949 considered to be the function which always returns 1.
7951 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
7952 parameters that occur in non-deduced contexts. When false, only
7953 visits those template parameters that can be deduced. */
7956 for_each_template_parm (tree t, tree_fn_t fn, void* data,
7957 struct pointer_set_t *visited,
7958 bool include_nondeduced_p)
7960 struct pair_fn_data pfd;
7966 pfd.include_nondeduced_p = include_nondeduced_p;
7968 /* Walk the tree. (Conceptually, we would like to walk without
7969 duplicates, but for_each_template_parm_r recursively calls
7970 for_each_template_parm, so we would need to reorganize a fair
7971 bit to use walk_tree_without_duplicates, so we keep our own
7974 pfd.visited = visited;
7976 pfd.visited = pointer_set_create ();
7977 result = cp_walk_tree (&t,
7978 for_each_template_parm_r,
7980 pfd.visited) != NULL_TREE;
7985 pointer_set_destroy (pfd.visited);
7992 /* Returns true if T depends on any template parameter. */
7995 uses_template_parms (tree t)
7998 int saved_processing_template_decl;
8000 saved_processing_template_decl = processing_template_decl;
8001 if (!saved_processing_template_decl)
8002 processing_template_decl = 1;
8004 dependent_p = dependent_type_p (t);
8005 else if (TREE_CODE (t) == TREE_VEC)
8006 dependent_p = any_dependent_template_arguments_p (t);
8007 else if (TREE_CODE (t) == TREE_LIST)
8008 dependent_p = (uses_template_parms (TREE_VALUE (t))
8009 || uses_template_parms (TREE_CHAIN (t)));
8010 else if (TREE_CODE (t) == TYPE_DECL)
8011 dependent_p = dependent_type_p (TREE_TYPE (t));
8014 || TREE_CODE (t) == TEMPLATE_PARM_INDEX
8015 || TREE_CODE (t) == OVERLOAD
8017 || TREE_CODE (t) == IDENTIFIER_NODE
8018 || TREE_CODE (t) == TRAIT_EXPR
8019 || TREE_CODE (t) == CONSTRUCTOR
8020 || CONSTANT_CLASS_P (t))
8021 dependent_p = (type_dependent_expression_p (t)
8022 || value_dependent_expression_p (t));
8025 gcc_assert (t == error_mark_node);
8026 dependent_p = false;
8029 processing_template_decl = saved_processing_template_decl;
8034 /* Returns true if T depends on any template parameter with level LEVEL. */
8037 uses_template_parms_level (tree t, int level)
8039 return for_each_template_parm (t, template_parm_this_level_p, &level, NULL,
8040 /*include_nondeduced_p=*/true);
8043 /* Returns TRUE iff INST is an instantiation we don't need to do in an
8044 ill-formed translation unit, i.e. a variable or function that isn't
8045 usable in a constant expression. */
8048 neglectable_inst_p (tree d)
8051 && !(TREE_CODE (d) == FUNCTION_DECL ? DECL_DECLARED_CONSTEXPR_P (d)
8052 : decl_maybe_constant_var_p (d)));
8055 /* Returns TRUE iff we should refuse to instantiate DECL because it's
8056 neglectable and instantiated from within an erroneous instantiation. */
8059 limit_bad_template_recursion (tree decl)
8061 struct tinst_level *lev = current_tinst_level;
8062 int errs = errorcount + sorrycount;
8063 if (lev == NULL || errs == 0 || !neglectable_inst_p (decl))
8066 for (; lev; lev = lev->next)
8067 if (neglectable_inst_p (lev->decl))
8070 return (lev && errs > lev->errors);
8073 static int tinst_depth;
8074 extern int max_tinst_depth;
8075 #ifdef GATHER_STATISTICS
8078 static GTY(()) struct tinst_level *last_error_tinst_level;
8080 /* We're starting to instantiate D; record the template instantiation context
8081 for diagnostics and to restore it later. */
8084 push_tinst_level (tree d)
8086 struct tinst_level *new_level;
8088 if (tinst_depth >= max_tinst_depth)
8090 last_error_tinst_level = current_tinst_level;
8091 if (TREE_CODE (d) == TREE_LIST)
8092 error ("template instantiation depth exceeds maximum of %d (use "
8093 "-ftemplate-depth= to increase the maximum) substituting %qS",
8094 max_tinst_depth, d);
8096 error ("template instantiation depth exceeds maximum of %d (use "
8097 "-ftemplate-depth= to increase the maximum) instantiating %qD",
8098 max_tinst_depth, d);
8100 print_instantiation_context ();
8105 /* If the current instantiation caused problems, don't let it instantiate
8106 anything else. Do allow deduction substitution and decls usable in
8107 constant expressions. */
8108 if (limit_bad_template_recursion (d))
8111 new_level = ggc_alloc_tinst_level ();
8112 new_level->decl = d;
8113 new_level->locus = input_location;
8114 new_level->errors = errorcount+sorrycount;
8115 new_level->in_system_header_p = in_system_header;
8116 new_level->next = current_tinst_level;
8117 current_tinst_level = new_level;
8120 #ifdef GATHER_STATISTICS
8121 if (tinst_depth > depth_reached)
8122 depth_reached = tinst_depth;
8128 /* We're done instantiating this template; return to the instantiation
8132 pop_tinst_level (void)
8134 /* Restore the filename and line number stashed away when we started
8135 this instantiation. */
8136 input_location = current_tinst_level->locus;
8137 current_tinst_level = current_tinst_level->next;
8141 /* We're instantiating a deferred template; restore the template
8142 instantiation context in which the instantiation was requested, which
8143 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
8146 reopen_tinst_level (struct tinst_level *level)
8148 struct tinst_level *t;
8151 for (t = level; t; t = t->next)
8154 current_tinst_level = level;
8156 if (current_tinst_level)
8157 current_tinst_level->errors = errorcount+sorrycount;
8161 /* Returns the TINST_LEVEL which gives the original instantiation
8164 struct tinst_level *
8165 outermost_tinst_level (void)
8167 struct tinst_level *level = current_tinst_level;
8170 level = level->next;
8174 /* Returns TRUE if PARM is a parameter of the template TEMPL. */
8177 parameter_of_template_p (tree parm, tree templ)
8182 if (!parm || !templ)
8185 gcc_assert (DECL_TEMPLATE_PARM_P (parm));
8186 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
8188 parms = DECL_TEMPLATE_PARMS (templ);
8189 parms = INNERMOST_TEMPLATE_PARMS (parms);
8191 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
8193 tree p = TREE_VALUE (TREE_VEC_ELT (parms, i));
8194 if (p == error_mark_node)
8198 || (DECL_INITIAL (parm)
8199 && DECL_INITIAL (parm) == DECL_INITIAL (p)))
8206 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
8207 vector of template arguments, as for tsubst.
8209 Returns an appropriate tsubst'd friend declaration. */
8212 tsubst_friend_function (tree decl, tree args)
8216 if (TREE_CODE (decl) == FUNCTION_DECL
8217 && DECL_TEMPLATE_INSTANTIATION (decl)
8218 && TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
8219 /* This was a friend declared with an explicit template
8220 argument list, e.g.:
8224 to indicate that f was a template instantiation, not a new
8225 function declaration. Now, we have to figure out what
8226 instantiation of what template. */
8228 tree template_id, arglist, fns;
8231 tree ns = decl_namespace_context (TYPE_MAIN_DECL (current_class_type));
8233 /* Friend functions are looked up in the containing namespace scope.
8234 We must enter that scope, to avoid finding member functions of the
8235 current class with same name. */
8236 push_nested_namespace (ns);
8237 fns = tsubst_expr (DECL_TI_TEMPLATE (decl), args,
8238 tf_warning_or_error, NULL_TREE,
8239 /*integral_constant_expression_p=*/false);
8240 pop_nested_namespace (ns);
8241 arglist = tsubst (DECL_TI_ARGS (decl), args,
8242 tf_warning_or_error, NULL_TREE);
8243 template_id = lookup_template_function (fns, arglist);
8245 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
8246 tmpl = determine_specialization (template_id, new_friend,
8248 /*need_member_template=*/0,
8249 TREE_VEC_LENGTH (args),
8251 return instantiate_template (tmpl, new_args, tf_error);
8254 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
8256 /* The NEW_FRIEND will look like an instantiation, to the
8257 compiler, but is not an instantiation from the point of view of
8258 the language. For example, we might have had:
8260 template <class T> struct S {
8261 template <class U> friend void f(T, U);
8264 Then, in S<int>, template <class U> void f(int, U) is not an
8265 instantiation of anything. */
8266 if (new_friend == error_mark_node)
8267 return error_mark_node;
8269 DECL_USE_TEMPLATE (new_friend) = 0;
8270 if (TREE_CODE (decl) == TEMPLATE_DECL)
8272 DECL_USE_TEMPLATE (DECL_TEMPLATE_RESULT (new_friend)) = 0;
8273 DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (new_friend))
8274 = DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (decl));
8277 /* The mangled name for the NEW_FRIEND is incorrect. The function
8278 is not a template instantiation and should not be mangled like
8279 one. Therefore, we forget the mangling here; we'll recompute it
8280 later if we need it. */
8281 if (TREE_CODE (new_friend) != TEMPLATE_DECL)
8283 SET_DECL_RTL (new_friend, NULL);
8284 SET_DECL_ASSEMBLER_NAME (new_friend, NULL_TREE);
8287 if (DECL_NAMESPACE_SCOPE_P (new_friend))
8290 tree new_friend_template_info;
8291 tree new_friend_result_template_info;
8293 int new_friend_is_defn;
8295 /* We must save some information from NEW_FRIEND before calling
8296 duplicate decls since that function will free NEW_FRIEND if
8298 new_friend_template_info = DECL_TEMPLATE_INFO (new_friend);
8299 new_friend_is_defn =
8300 (DECL_INITIAL (DECL_TEMPLATE_RESULT
8301 (template_for_substitution (new_friend)))
8303 if (TREE_CODE (new_friend) == TEMPLATE_DECL)
8305 /* This declaration is a `primary' template. */
8306 DECL_PRIMARY_TEMPLATE (new_friend) = new_friend;
8308 new_friend_result_template_info
8309 = DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (new_friend));
8312 new_friend_result_template_info = NULL_TREE;
8314 /* Make the init_value nonzero so pushdecl knows this is a defn. */
8315 if (new_friend_is_defn)
8316 DECL_INITIAL (new_friend) = error_mark_node;
8318 /* Inside pushdecl_namespace_level, we will push into the
8319 current namespace. However, the friend function should go
8320 into the namespace of the template. */
8321 ns = decl_namespace_context (new_friend);
8322 push_nested_namespace (ns);
8323 old_decl = pushdecl_namespace_level (new_friend, /*is_friend=*/true);
8324 pop_nested_namespace (ns);
8326 if (old_decl == error_mark_node)
8327 return error_mark_node;
8329 if (old_decl != new_friend)
8331 /* This new friend declaration matched an existing
8332 declaration. For example, given:
8334 template <class T> void f(T);
8335 template <class U> class C {
8336 template <class T> friend void f(T) {}
8339 the friend declaration actually provides the definition
8340 of `f', once C has been instantiated for some type. So,
8341 old_decl will be the out-of-class template declaration,
8342 while new_friend is the in-class definition.
8344 But, if `f' was called before this point, the
8345 instantiation of `f' will have DECL_TI_ARGS corresponding
8346 to `T' but not to `U', references to which might appear
8347 in the definition of `f'. Previously, the most general
8348 template for an instantiation of `f' was the out-of-class
8349 version; now it is the in-class version. Therefore, we
8350 run through all specialization of `f', adding to their
8351 DECL_TI_ARGS appropriately. In particular, they need a
8352 new set of outer arguments, corresponding to the
8353 arguments for this class instantiation.
8355 The same situation can arise with something like this:
8358 template <class T> class C {
8362 when `C<int>' is instantiated. Now, `f(int)' is defined
8365 if (!new_friend_is_defn)
8366 /* On the other hand, if the in-class declaration does
8367 *not* provide a definition, then we don't want to alter
8368 existing definitions. We can just leave everything
8373 tree new_template = TI_TEMPLATE (new_friend_template_info);
8374 tree new_args = TI_ARGS (new_friend_template_info);
8376 /* Overwrite whatever template info was there before, if
8377 any, with the new template information pertaining to
8379 DECL_TEMPLATE_INFO (old_decl) = new_friend_template_info;
8381 if (TREE_CODE (old_decl) != TEMPLATE_DECL)
8383 /* We should have called reregister_specialization in
8385 gcc_assert (retrieve_specialization (new_template,
8389 /* Instantiate it if the global has already been used. */
8390 if (DECL_ODR_USED (old_decl))
8391 instantiate_decl (old_decl, /*defer_ok=*/true,
8392 /*expl_inst_class_mem_p=*/false);
8398 /* Indicate that the old function template is a partial
8400 DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (old_decl))
8401 = new_friend_result_template_info;
8403 gcc_assert (new_template
8404 == most_general_template (new_template));
8405 gcc_assert (new_template != old_decl);
8407 /* Reassign any specializations already in the hash table
8408 to the new more general template, and add the
8409 additional template args. */
8410 for (t = DECL_TEMPLATE_INSTANTIATIONS (old_decl);
8414 tree spec = TREE_VALUE (t);
8417 elt.tmpl = old_decl;
8418 elt.args = DECL_TI_ARGS (spec);
8419 elt.spec = NULL_TREE;
8421 htab_remove_elt (decl_specializations, &elt);
8424 = add_outermost_template_args (new_args,
8425 DECL_TI_ARGS (spec));
8427 register_specialization
8428 (spec, new_template, DECL_TI_ARGS (spec), true, 0);
8431 DECL_TEMPLATE_INSTANTIATIONS (old_decl) = NULL_TREE;
8435 /* The information from NEW_FRIEND has been merged into OLD_DECL
8436 by duplicate_decls. */
8437 new_friend = old_decl;
8442 tree context = DECL_CONTEXT (new_friend);
8446 template <class T> class C {
8447 template <class U> friend void C1<U>::f (); // case 1
8448 friend void C2<T>::f (); // case 2
8450 we only need to make sure CONTEXT is a complete type for
8451 case 2. To distinguish between the two cases, we note that
8452 CONTEXT of case 1 remains dependent type after tsubst while
8453 this isn't true for case 2. */
8454 ++processing_template_decl;
8455 dependent_p = dependent_type_p (context);
8456 --processing_template_decl;
8459 && !complete_type_or_else (context, NULL_TREE))
8460 return error_mark_node;
8462 if (COMPLETE_TYPE_P (context))
8464 /* Check to see that the declaration is really present, and,
8465 possibly obtain an improved declaration. */
8466 tree fn = check_classfn (context,
8467 new_friend, NULL_TREE);
8477 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
8478 template arguments, as for tsubst.
8480 Returns an appropriate tsubst'd friend type or error_mark_node on
8484 tsubst_friend_class (tree friend_tmpl, tree args)
8490 context = CP_DECL_CONTEXT (friend_tmpl);
8492 if (context != global_namespace)
8494 if (TREE_CODE (context) == NAMESPACE_DECL)
8495 push_nested_namespace (context);
8497 push_nested_class (tsubst (context, args, tf_none, NULL_TREE));
8500 /* Look for a class template declaration. We look for hidden names
8501 because two friend declarations of the same template are the
8502 same. For example, in:
8505 template <typename> friend class F;
8507 template <typename> struct B {
8508 template <typename> friend class F;
8511 both F templates are the same. */
8512 tmpl = lookup_name_real (DECL_NAME (friend_tmpl), 0, 0,
8513 /*block_p=*/true, 0,
8514 LOOKUP_COMPLAIN | LOOKUP_HIDDEN);
8516 /* But, if we don't find one, it might be because we're in a
8517 situation like this:
8525 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
8526 for `S<int>', not the TEMPLATE_DECL. */
8527 if (!tmpl || !DECL_CLASS_TEMPLATE_P (tmpl))
8529 tmpl = lookup_name_prefer_type (DECL_NAME (friend_tmpl), 1);
8530 tmpl = maybe_get_template_decl_from_type_decl (tmpl);
8533 if (tmpl && DECL_CLASS_TEMPLATE_P (tmpl))
8535 /* The friend template has already been declared. Just
8536 check to see that the declarations match, and install any new
8537 default parameters. We must tsubst the default parameters,
8538 of course. We only need the innermost template parameters
8539 because that is all that redeclare_class_template will look
8541 if (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (friend_tmpl))
8542 > TMPL_ARGS_DEPTH (args))
8545 location_t saved_input_location;
8546 parms = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_tmpl),
8547 args, tf_warning_or_error);
8549 saved_input_location = input_location;
8550 input_location = DECL_SOURCE_LOCATION (friend_tmpl);
8551 redeclare_class_template (TREE_TYPE (tmpl), parms);
8552 input_location = saved_input_location;
8556 friend_type = TREE_TYPE (tmpl);
8560 /* The friend template has not already been declared. In this
8561 case, the instantiation of the template class will cause the
8562 injection of this template into the global scope. */
8563 tmpl = tsubst (friend_tmpl, args, tf_warning_or_error, NULL_TREE);
8564 if (tmpl == error_mark_node)
8565 return error_mark_node;
8567 /* The new TMPL is not an instantiation of anything, so we
8568 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
8569 the new type because that is supposed to be the corresponding
8570 template decl, i.e., TMPL. */
8571 DECL_USE_TEMPLATE (tmpl) = 0;
8572 DECL_TEMPLATE_INFO (tmpl) = NULL_TREE;
8573 CLASSTYPE_USE_TEMPLATE (TREE_TYPE (tmpl)) = 0;
8574 CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl))
8575 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl)));
8577 /* Inject this template into the global scope. */
8578 friend_type = TREE_TYPE (pushdecl_top_level_maybe_friend (tmpl, true));
8581 if (context != global_namespace)
8583 if (TREE_CODE (context) == NAMESPACE_DECL)
8584 pop_nested_namespace (context);
8586 pop_nested_class ();
8592 /* Returns zero if TYPE cannot be completed later due to circularity.
8593 Otherwise returns one. */
8596 can_complete_type_without_circularity (tree type)
8598 if (type == NULL_TREE || type == error_mark_node)
8600 else if (COMPLETE_TYPE_P (type))
8602 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
8603 return can_complete_type_without_circularity (TREE_TYPE (type));
8604 else if (CLASS_TYPE_P (type)
8605 && TYPE_BEING_DEFINED (TYPE_MAIN_VARIANT (type)))
8611 /* Apply any attributes which had to be deferred until instantiation
8612 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
8613 ARGS, COMPLAIN, IN_DECL are as tsubst. */
8616 apply_late_template_attributes (tree *decl_p, tree attributes, int attr_flags,
8617 tree args, tsubst_flags_t complain, tree in_decl)
8619 tree last_dep = NULL_TREE;
8623 for (t = attributes; t; t = TREE_CHAIN (t))
8624 if (ATTR_IS_DEPENDENT (t))
8627 attributes = copy_list (attributes);
8631 if (DECL_P (*decl_p))
8633 if (TREE_TYPE (*decl_p) == error_mark_node)
8635 p = &DECL_ATTRIBUTES (*decl_p);
8638 p = &TYPE_ATTRIBUTES (*decl_p);
8642 tree late_attrs = NULL_TREE;
8643 tree *q = &late_attrs;
8645 for (*p = attributes; *p; )
8648 if (ATTR_IS_DEPENDENT (t))
8650 *p = TREE_CHAIN (t);
8651 TREE_CHAIN (t) = NULL_TREE;
8652 /* If the first attribute argument is an identifier, don't
8653 pass it through tsubst. Attributes like mode, format,
8654 cleanup and several target specific attributes expect it
8657 && TREE_CODE (TREE_VALUE (t)) == TREE_LIST
8658 && TREE_VALUE (TREE_VALUE (t))
8659 && (TREE_CODE (TREE_VALUE (TREE_VALUE (t)))
8660 == IDENTIFIER_NODE))
8663 = tsubst_expr (TREE_CHAIN (TREE_VALUE (t)), args, complain,
8665 /*integral_constant_expression_p=*/false);
8666 if (chain != TREE_CHAIN (TREE_VALUE (t)))
8668 = tree_cons (NULL_TREE, TREE_VALUE (TREE_VALUE (t)),
8673 = tsubst_expr (TREE_VALUE (t), args, complain, in_decl,
8674 /*integral_constant_expression_p=*/false);
8676 q = &TREE_CHAIN (t);
8679 p = &TREE_CHAIN (t);
8682 cplus_decl_attributes (decl_p, late_attrs, attr_flags);
8686 /* Perform (or defer) access check for typedefs that were referenced
8687 from within the template TMPL code.
8688 This is a subroutine of instantiate_template and instantiate_class_template.
8689 TMPL is the template to consider and TARGS is the list of arguments of
8693 perform_typedefs_access_check (tree tmpl, tree targs)
8695 location_t saved_location;
8697 qualified_typedef_usage_t *iter;
8700 || (!CLASS_TYPE_P (tmpl)
8701 && TREE_CODE (tmpl) != FUNCTION_DECL))
8704 saved_location = input_location;
8705 FOR_EACH_VEC_ELT (qualified_typedef_usage_t,
8706 get_types_needing_access_check (tmpl),
8709 tree type_decl = iter->typedef_decl;
8710 tree type_scope = iter->context;
8712 if (!type_decl || !type_scope || !CLASS_TYPE_P (type_scope))
8715 if (uses_template_parms (type_decl))
8716 type_decl = tsubst (type_decl, targs, tf_error, NULL_TREE);
8717 if (uses_template_parms (type_scope))
8718 type_scope = tsubst (type_scope, targs, tf_error, NULL_TREE);
8720 /* Make access check error messages point to the location
8721 of the use of the typedef. */
8722 input_location = iter->locus;
8723 perform_or_defer_access_check (TYPE_BINFO (type_scope),
8724 type_decl, type_decl);
8726 input_location = saved_location;
8730 instantiate_class_template_1 (tree type)
8732 tree templ, args, pattern, t, member;
8736 unsigned int saved_maximum_field_alignment;
8739 if (type == error_mark_node)
8740 return error_mark_node;
8742 if (COMPLETE_OR_OPEN_TYPE_P (type)
8743 || uses_template_parms (type))
8746 /* Figure out which template is being instantiated. */
8747 templ = most_general_template (CLASSTYPE_TI_TEMPLATE (type));
8748 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
8750 /* Determine what specialization of the original template to
8752 t = most_specialized_class (type, templ, tf_warning_or_error);
8753 if (t == error_mark_node)
8755 TYPE_BEING_DEFINED (type) = 1;
8756 return error_mark_node;
8760 /* This TYPE is actually an instantiation of a partial
8761 specialization. We replace the innermost set of ARGS with
8762 the arguments appropriate for substitution. For example,
8765 template <class T> struct S {};
8766 template <class T> struct S<T*> {};
8768 and supposing that we are instantiating S<int*>, ARGS will
8769 presently be {int*} -- but we need {int}. */
8770 pattern = TREE_TYPE (t);
8771 args = TREE_PURPOSE (t);
8775 pattern = TREE_TYPE (templ);
8776 args = CLASSTYPE_TI_ARGS (type);
8779 /* If the template we're instantiating is incomplete, then clearly
8780 there's nothing we can do. */
8781 if (!COMPLETE_TYPE_P (pattern))
8784 /* If we've recursively instantiated too many templates, stop. */
8785 if (! push_tinst_level (type))
8788 /* Now we're really doing the instantiation. Mark the type as in
8789 the process of being defined. */
8790 TYPE_BEING_DEFINED (type) = 1;
8792 /* We may be in the middle of deferred access check. Disable
8794 push_deferring_access_checks (dk_no_deferred);
8796 fn_context = decl_function_context (TYPE_MAIN_DECL (type));
8798 push_to_top_level ();
8799 /* Use #pragma pack from the template context. */
8800 saved_maximum_field_alignment = maximum_field_alignment;
8801 maximum_field_alignment = TYPE_PRECISION (pattern);
8803 SET_CLASSTYPE_INTERFACE_UNKNOWN (type);
8805 /* Set the input location to the most specialized template definition.
8806 This is needed if tsubsting causes an error. */
8807 typedecl = TYPE_MAIN_DECL (pattern);
8808 input_location = DECL_SOURCE_LOCATION (TYPE_NAME (type)) =
8809 DECL_SOURCE_LOCATION (typedecl);
8811 TYPE_PACKED (type) = TYPE_PACKED (pattern);
8812 TYPE_ALIGN (type) = TYPE_ALIGN (pattern);
8813 TYPE_USER_ALIGN (type) = TYPE_USER_ALIGN (pattern);
8814 TYPE_FOR_JAVA (type) = TYPE_FOR_JAVA (pattern); /* For libjava's JArray<T> */
8815 if (ANON_AGGR_TYPE_P (pattern))
8816 SET_ANON_AGGR_TYPE_P (type);
8817 if (CLASSTYPE_VISIBILITY_SPECIFIED (pattern))
8819 CLASSTYPE_VISIBILITY_SPECIFIED (type) = 1;
8820 CLASSTYPE_VISIBILITY (type) = CLASSTYPE_VISIBILITY (pattern);
8821 /* Adjust visibility for template arguments. */
8822 determine_visibility (TYPE_MAIN_DECL (type));
8824 CLASSTYPE_FINAL (type) = CLASSTYPE_FINAL (pattern);
8826 pbinfo = TYPE_BINFO (pattern);
8828 /* We should never instantiate a nested class before its enclosing
8829 class; we need to look up the nested class by name before we can
8830 instantiate it, and that lookup should instantiate the enclosing
8832 gcc_assert (!DECL_CLASS_SCOPE_P (TYPE_MAIN_DECL (pattern))
8833 || COMPLETE_OR_OPEN_TYPE_P (TYPE_CONTEXT (type)));
8835 base_list = NULL_TREE;
8836 if (BINFO_N_BASE_BINFOS (pbinfo))
8842 /* We must enter the scope containing the type, as that is where
8843 the accessibility of types named in dependent bases are
8845 pushed_scope = push_scope (CP_TYPE_CONTEXT (type));
8847 /* Substitute into each of the bases to determine the actual
8849 for (i = 0; BINFO_BASE_ITERATE (pbinfo, i, pbase_binfo); i++)
8852 tree access = BINFO_BASE_ACCESS (pbinfo, i);
8853 tree expanded_bases = NULL_TREE;
8856 if (PACK_EXPANSION_P (BINFO_TYPE (pbase_binfo)))
8859 tsubst_pack_expansion (BINFO_TYPE (pbase_binfo),
8860 args, tf_error, NULL_TREE);
8861 if (expanded_bases == error_mark_node)
8864 len = TREE_VEC_LENGTH (expanded_bases);
8867 for (idx = 0; idx < len; idx++)
8870 /* Extract the already-expanded base class. */
8871 base = TREE_VEC_ELT (expanded_bases, idx);
8873 /* Substitute to figure out the base class. */
8874 base = tsubst (BINFO_TYPE (pbase_binfo), args, tf_error,
8877 if (base == error_mark_node)
8880 base_list = tree_cons (access, base, base_list);
8881 if (BINFO_VIRTUAL_P (pbase_binfo))
8882 TREE_TYPE (base_list) = integer_type_node;
8886 /* The list is now in reverse order; correct that. */
8887 base_list = nreverse (base_list);
8890 pop_scope (pushed_scope);
8892 /* Now call xref_basetypes to set up all the base-class
8894 xref_basetypes (type, base_list);
8896 apply_late_template_attributes (&type, TYPE_ATTRIBUTES (pattern),
8897 (int) ATTR_FLAG_TYPE_IN_PLACE,
8898 args, tf_error, NULL_TREE);
8899 fixup_attribute_variants (type);
8901 /* Now that our base classes are set up, enter the scope of the
8902 class, so that name lookups into base classes, etc. will work
8903 correctly. This is precisely analogous to what we do in
8904 begin_class_definition when defining an ordinary non-template
8905 class, except we also need to push the enclosing classes. */
8906 push_nested_class (type);
8908 /* Now members are processed in the order of declaration. */
8909 for (member = CLASSTYPE_DECL_LIST (pattern);
8910 member; member = TREE_CHAIN (member))
8912 tree t = TREE_VALUE (member);
8914 if (TREE_PURPOSE (member))
8918 /* Build new CLASSTYPE_NESTED_UTDS. */
8921 bool class_template_p;
8923 class_template_p = (TREE_CODE (t) != ENUMERAL_TYPE
8924 && TYPE_LANG_SPECIFIC (t)
8925 && CLASSTYPE_IS_TEMPLATE (t));
8926 /* If the member is a class template, then -- even after
8927 substitution -- there may be dependent types in the
8928 template argument list for the class. We increment
8929 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
8930 that function will assume that no types are dependent
8931 when outside of a template. */
8932 if (class_template_p)
8933 ++processing_template_decl;
8934 newtag = tsubst (t, args, tf_error, NULL_TREE);
8935 if (class_template_p)
8936 --processing_template_decl;
8937 if (newtag == error_mark_node)
8940 if (TREE_CODE (newtag) != ENUMERAL_TYPE)
8942 tree name = TYPE_IDENTIFIER (t);
8944 if (class_template_p)
8945 /* Unfortunately, lookup_template_class sets
8946 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
8947 instantiation (i.e., for the type of a member
8948 template class nested within a template class.)
8949 This behavior is required for
8950 maybe_process_partial_specialization to work
8951 correctly, but is not accurate in this case;
8952 the TAG is not an instantiation of anything.
8953 (The corresponding TEMPLATE_DECL is an
8954 instantiation, but the TYPE is not.) */
8955 CLASSTYPE_USE_TEMPLATE (newtag) = 0;
8957 /* Now, we call pushtag to put this NEWTAG into the scope of
8958 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
8959 pushtag calling push_template_decl. We don't have to do
8960 this for enums because it will already have been done in
8963 SET_IDENTIFIER_TYPE_VALUE (name, newtag);
8964 pushtag (name, newtag, /*tag_scope=*/ts_current);
8967 else if (TREE_CODE (t) == FUNCTION_DECL
8968 || DECL_FUNCTION_TEMPLATE_P (t))
8970 /* Build new TYPE_METHODS. */
8973 if (TREE_CODE (t) == TEMPLATE_DECL)
8974 ++processing_template_decl;
8975 r = tsubst (t, args, tf_error, NULL_TREE);
8976 if (TREE_CODE (t) == TEMPLATE_DECL)
8977 --processing_template_decl;
8978 set_current_access_from_decl (r);
8979 finish_member_declaration (r);
8980 /* Instantiate members marked with attribute used. */
8981 if (r != error_mark_node && DECL_PRESERVE_P (r))
8986 /* Build new TYPE_FIELDS. */
8987 if (TREE_CODE (t) == STATIC_ASSERT)
8990 tsubst_expr (STATIC_ASSERT_CONDITION (t), args,
8991 tf_warning_or_error, NULL_TREE,
8992 /*integral_constant_expression_p=*/true);
8993 finish_static_assert (condition,
8994 STATIC_ASSERT_MESSAGE (t),
8995 STATIC_ASSERT_SOURCE_LOCATION (t),
8998 else if (TREE_CODE (t) != CONST_DECL)
9002 /* The file and line for this declaration, to
9003 assist in error message reporting. Since we
9004 called push_tinst_level above, we don't need to
9006 input_location = DECL_SOURCE_LOCATION (t);
9008 if (TREE_CODE (t) == TEMPLATE_DECL)
9009 ++processing_template_decl;
9010 r = tsubst (t, args, tf_warning_or_error, NULL_TREE);
9011 if (TREE_CODE (t) == TEMPLATE_DECL)
9012 --processing_template_decl;
9013 if (TREE_CODE (r) == VAR_DECL)
9017 [t]he initialization (and any associated
9018 side-effects) of a static data member does
9019 not occur unless the static data member is
9020 itself used in a way that requires the
9021 definition of the static data member to
9024 Therefore, we do not substitute into the
9025 initialized for the static data member here. */
9026 finish_static_data_member_decl
9029 /*init_const_expr_p=*/false,
9030 /*asmspec_tree=*/NULL_TREE,
9032 /* Instantiate members marked with attribute used. */
9033 if (r != error_mark_node && DECL_PRESERVE_P (r))
9036 else if (TREE_CODE (r) == FIELD_DECL)
9038 /* Determine whether R has a valid type and can be
9039 completed later. If R is invalid, then it is
9040 replaced by error_mark_node so that it will not be
9041 added to TYPE_FIELDS. */
9042 tree rtype = TREE_TYPE (r);
9043 if (can_complete_type_without_circularity (rtype))
9044 complete_type (rtype);
9046 if (!COMPLETE_TYPE_P (rtype))
9048 cxx_incomplete_type_error (r, rtype);
9049 r = error_mark_node;
9053 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
9054 such a thing will already have been added to the field
9055 list by tsubst_enum in finish_member_declaration in the
9056 CLASSTYPE_NESTED_UTDS case above. */
9057 if (!(TREE_CODE (r) == TYPE_DECL
9058 && TREE_CODE (TREE_TYPE (r)) == ENUMERAL_TYPE
9059 && DECL_ARTIFICIAL (r)))
9061 set_current_access_from_decl (r);
9062 finish_member_declaration (r);
9069 if (TYPE_P (t) || DECL_CLASS_TEMPLATE_P (t))
9071 /* Build new CLASSTYPE_FRIEND_CLASSES. */
9073 tree friend_type = t;
9074 bool adjust_processing_template_decl = false;
9076 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
9078 /* template <class T> friend class C; */
9079 friend_type = tsubst_friend_class (friend_type, args);
9080 adjust_processing_template_decl = true;
9082 else if (TREE_CODE (friend_type) == UNBOUND_CLASS_TEMPLATE)
9084 /* template <class T> friend class C::D; */
9085 friend_type = tsubst (friend_type, args,
9086 tf_warning_or_error, NULL_TREE);
9087 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
9088 friend_type = TREE_TYPE (friend_type);
9089 adjust_processing_template_decl = true;
9091 else if (TREE_CODE (friend_type) == TYPENAME_TYPE
9092 || TREE_CODE (friend_type) == TEMPLATE_TYPE_PARM)
9094 /* This could be either
9098 when dependent_type_p is false or
9100 template <class U> friend class T::C;
9103 friend_type = tsubst (friend_type, args,
9104 tf_warning_or_error, NULL_TREE);
9105 /* Bump processing_template_decl for correct
9106 dependent_type_p calculation. */
9107 ++processing_template_decl;
9108 if (dependent_type_p (friend_type))
9109 adjust_processing_template_decl = true;
9110 --processing_template_decl;
9112 else if (!CLASSTYPE_USE_TEMPLATE (friend_type)
9113 && hidden_name_p (TYPE_NAME (friend_type)))
9117 where C hasn't been declared yet. Let's lookup name
9118 from namespace scope directly, bypassing any name that
9119 come from dependent base class. */
9120 tree ns = decl_namespace_context (TYPE_MAIN_DECL (friend_type));
9122 /* The call to xref_tag_from_type does injection for friend
9124 push_nested_namespace (ns);
9126 xref_tag_from_type (friend_type, NULL_TREE,
9127 /*tag_scope=*/ts_current);
9128 pop_nested_namespace (ns);
9130 else if (uses_template_parms (friend_type))
9131 /* friend class C<T>; */
9132 friend_type = tsubst (friend_type, args,
9133 tf_warning_or_error, NULL_TREE);
9138 where C is already declared or
9140 friend class C<int>;
9142 We don't have to do anything in these cases. */
9144 if (adjust_processing_template_decl)
9145 /* Trick make_friend_class into realizing that the friend
9146 we're adding is a template, not an ordinary class. It's
9147 important that we use make_friend_class since it will
9148 perform some error-checking and output cross-reference
9150 ++processing_template_decl;
9152 if (friend_type != error_mark_node)
9153 make_friend_class (type, friend_type, /*complain=*/false);
9155 if (adjust_processing_template_decl)
9156 --processing_template_decl;
9160 /* Build new DECL_FRIENDLIST. */
9163 /* The file and line for this declaration, to
9164 assist in error message reporting. Since we
9165 called push_tinst_level above, we don't need to
9167 input_location = DECL_SOURCE_LOCATION (t);
9169 if (TREE_CODE (t) == TEMPLATE_DECL)
9171 ++processing_template_decl;
9172 push_deferring_access_checks (dk_no_check);
9175 r = tsubst_friend_function (t, args);
9176 add_friend (type, r, /*complain=*/false);
9177 if (TREE_CODE (t) == TEMPLATE_DECL)
9179 pop_deferring_access_checks ();
9180 --processing_template_decl;
9186 if (CLASSTYPE_LAMBDA_EXPR (type))
9188 tree decl = lambda_function (type);
9191 tree lambda = CLASSTYPE_LAMBDA_EXPR (type);
9192 if (LAMBDA_EXPR_DEDUCE_RETURN_TYPE_P (lambda))
9194 apply_lambda_return_type (lambda, void_type_node);
9195 LAMBDA_EXPR_RETURN_TYPE (lambda) = NULL_TREE;
9198 LAMBDA_EXPR_THIS_CAPTURE (lambda)
9199 = lookup_field_1 (type, get_identifier ("__this"), false);
9201 instantiate_decl (decl, false, false);
9202 maybe_add_lambda_conv_op (type);
9204 LAMBDA_EXPR_THIS_CAPTURE (lambda) = NULL_TREE;
9207 gcc_assert (errorcount);
9210 /* Set the file and line number information to whatever is given for
9211 the class itself. This puts error messages involving generated
9212 implicit functions at a predictable point, and the same point
9213 that would be used for non-template classes. */
9214 input_location = DECL_SOURCE_LOCATION (typedecl);
9216 unreverse_member_declarations (type);
9217 finish_struct_1 (type);
9218 TYPE_BEING_DEFINED (type) = 0;
9220 /* We don't instantiate default arguments for member functions. 14.7.1:
9222 The implicit instantiation of a class template specialization causes
9223 the implicit instantiation of the declarations, but not of the
9224 definitions or default arguments, of the class member functions,
9225 member classes, static data members and member templates.... */
9227 /* Some typedefs referenced from within the template code need to be access
9228 checked at template instantiation time, i.e now. These types were
9229 added to the template at parsing time. Let's get those and perform
9230 the access checks then. */
9231 perform_typedefs_access_check (pattern, args);
9232 perform_deferred_access_checks ();
9233 pop_nested_class ();
9234 maximum_field_alignment = saved_maximum_field_alignment;
9236 pop_from_top_level ();
9237 pop_deferring_access_checks ();
9240 /* The vtable for a template class can be emitted in any translation
9241 unit in which the class is instantiated. When there is no key
9242 method, however, finish_struct_1 will already have added TYPE to
9243 the keyed_classes list. */
9244 if (TYPE_CONTAINS_VPTR_P (type) && CLASSTYPE_KEY_METHOD (type))
9245 keyed_classes = tree_cons (NULL_TREE, type, keyed_classes);
9250 /* Wrapper for instantiate_class_template_1. */
9253 instantiate_class_template (tree type)
9256 timevar_push (TV_TEMPLATE_INST);
9257 ret = instantiate_class_template_1 (type);
9258 timevar_pop (TV_TEMPLATE_INST);
9263 tsubst_template_arg (tree t, tree args, tsubst_flags_t complain, tree in_decl)
9269 else if (TYPE_P (t))
9270 r = tsubst (t, args, complain, in_decl);
9273 if (!(complain & tf_warning))
9274 ++c_inhibit_evaluation_warnings;
9275 r = tsubst_expr (t, args, complain, in_decl,
9276 /*integral_constant_expression_p=*/true);
9277 if (!(complain & tf_warning))
9278 --c_inhibit_evaluation_warnings;
9279 /* Preserve the raw-reference nature of T. */
9280 if (TREE_TYPE (t) && TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE
9281 && REFERENCE_REF_P (r))
9282 r = TREE_OPERAND (r, 0);
9287 /* Given a function parameter pack TMPL_PARM and some function parameters
9288 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
9289 and set *SPEC_P to point at the next point in the list. */
9292 extract_fnparm_pack (tree tmpl_parm, tree *spec_p)
9294 /* Collect all of the extra "packed" parameters into an
9298 tree argpack = make_node (NONTYPE_ARGUMENT_PACK);
9299 tree argtypepack = cxx_make_type (TYPE_ARGUMENT_PACK);
9300 tree spec_parm = *spec_p;
9303 for (len = 0; spec_parm; ++len, spec_parm = TREE_CHAIN (spec_parm))
9305 && !function_parameter_expanded_from_pack_p (spec_parm, tmpl_parm))
9308 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
9309 parmvec = make_tree_vec (len);
9310 parmtypevec = make_tree_vec (len);
9311 spec_parm = *spec_p;
9312 for (i = 0; i < len; i++, spec_parm = DECL_CHAIN (spec_parm))
9314 TREE_VEC_ELT (parmvec, i) = spec_parm;
9315 TREE_VEC_ELT (parmtypevec, i) = TREE_TYPE (spec_parm);
9318 /* Build the argument packs. */
9319 SET_ARGUMENT_PACK_ARGS (argpack, parmvec);
9320 SET_ARGUMENT_PACK_ARGS (argtypepack, parmtypevec);
9321 TREE_TYPE (argpack) = argtypepack;
9322 *spec_p = spec_parm;
9327 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
9328 NONTYPE_ARGUMENT_PACK. */
9331 make_fnparm_pack (tree spec_parm)
9333 return extract_fnparm_pack (NULL_TREE, &spec_parm);
9336 /* Substitute ARGS into T, which is an pack expansion
9337 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
9338 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
9339 (if only a partial substitution could be performed) or
9340 ERROR_MARK_NODE if there was an error. */
9342 tsubst_pack_expansion (tree t, tree args, tsubst_flags_t complain,
9346 tree pack, packs = NULL_TREE;
9347 bool unsubstituted_packs = false;
9348 bool real_packs = false;
9349 int missing_level = 0;
9352 htab_t saved_local_specializations = NULL;
9353 bool need_local_specializations = false;
9356 gcc_assert (PACK_EXPANSION_P (t));
9357 pattern = PACK_EXPANSION_PATTERN (t);
9359 /* Add in any args remembered from an earlier partial instantiation. */
9360 args = add_to_template_args (PACK_EXPANSION_EXTRA_ARGS (t), args);
9362 levels = TMPL_ARGS_DEPTH (args);
9364 /* Determine the argument packs that will instantiate the parameter
9365 packs used in the expansion expression. While we're at it,
9366 compute the number of arguments to be expanded and make sure it
9368 for (pack = PACK_EXPANSION_PARAMETER_PACKS (t); pack;
9369 pack = TREE_CHAIN (pack))
9371 tree parm_pack = TREE_VALUE (pack);
9372 tree arg_pack = NULL_TREE;
9373 tree orig_arg = NULL_TREE;
9376 if (TREE_CODE (parm_pack) == BASES)
9378 if (BASES_DIRECT (parm_pack))
9379 return calculate_direct_bases (tsubst_expr (BASES_TYPE (parm_pack),
9380 args, complain, in_decl, false));
9382 return calculate_bases (tsubst_expr (BASES_TYPE (parm_pack),
9383 args, complain, in_decl, false));
9385 if (TREE_CODE (parm_pack) == PARM_DECL)
9387 if (PACK_EXPANSION_LOCAL_P (t))
9388 arg_pack = retrieve_local_specialization (parm_pack);
9391 /* We can't rely on local_specializations for a parameter
9392 name used later in a function declaration (such as in a
9393 late-specified return type). Even if it exists, it might
9394 have the wrong value for a recursive call. Just make a
9395 dummy decl, since it's only used for its type. */
9396 /* Copy before tsubsting so that we don't recurse into any
9397 later PARM_DECLs. */
9398 arg_pack = tsubst_decl (copy_node (parm_pack), args, complain);
9399 if (arg_pack && FUNCTION_PARAMETER_PACK_P (arg_pack))
9400 /* Partial instantiation of the parm_pack, we can't build
9401 up an argument pack yet. */
9402 arg_pack = NULL_TREE;
9404 arg_pack = make_fnparm_pack (arg_pack);
9405 need_local_specializations = true;
9411 template_parm_level_and_index (parm_pack, &level, &idx);
9413 if (level <= levels)
9414 arg_pack = TMPL_ARG (args, level, idx);
9417 orig_arg = arg_pack;
9418 if (arg_pack && TREE_CODE (arg_pack) == ARGUMENT_PACK_SELECT)
9419 arg_pack = ARGUMENT_PACK_SELECT_FROM_PACK (arg_pack);
9421 if (arg_pack && !ARGUMENT_PACK_P (arg_pack))
9422 /* This can only happen if we forget to expand an argument
9423 pack somewhere else. Just return an error, silently. */
9425 result = make_tree_vec (1);
9426 TREE_VEC_ELT (result, 0) = error_mark_node;
9430 if (arg_from_parm_pack_p (arg_pack, parm_pack))
9431 /* The argument pack that the parameter maps to is just an
9432 expansion of the parameter itself, such as one would find
9433 in the implicit typedef of a class inside the class itself.
9434 Consider this parameter "unsubstituted", so that we will
9435 maintain the outer pack expansion. */
9436 arg_pack = NULL_TREE;
9441 TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack));
9443 /* Don't bother trying to do a partial substitution with
9444 incomplete packs; we'll try again after deduction. */
9445 if (ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
9450 else if (len != my_len)
9452 if (!(complain & tf_error))
9453 /* Fail quietly. */;
9454 else if (TREE_CODE (t) == TYPE_PACK_EXPANSION)
9455 error ("mismatched argument pack lengths while expanding "
9459 error ("mismatched argument pack lengths while expanding "
9462 return error_mark_node;
9465 if (TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack)) == 1
9466 && PACK_EXPANSION_P (TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack),
9468 /* This isn't a real argument pack yet. */;
9472 /* Keep track of the parameter packs and their corresponding
9474 packs = tree_cons (parm_pack, arg_pack, packs);
9475 TREE_TYPE (packs) = orig_arg;
9479 /* We can't substitute for this parameter pack. We use a flag as
9480 well as the missing_level counter because function parameter
9481 packs don't have a level. */
9482 unsubstituted_packs = true;
9483 if (!missing_level || missing_level > level)
9484 missing_level = level;
9488 /* We cannot expand this expansion expression, because we don't have
9489 all of the argument packs we need. */
9490 if (unsubstituted_packs)
9494 /* We got some full packs, but we can't substitute them in until we
9495 have values for all the packs. So remember these until then. */
9498 t = make_pack_expansion (pattern);
9500 /* The call to add_to_template_args above assumes no overlap
9501 between saved args and new args, so prune away any fake
9502 args, i.e. those that satisfied arg_from_parm_pack_p above. */
9503 if (missing_level && levels >= missing_level)
9505 gcc_assert (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args)
9506 && missing_level > 1);
9507 TREE_VEC_LENGTH (args) = missing_level - 1;
9508 save_args = copy_node (args);
9509 TREE_VEC_LENGTH (args) = levels;
9514 PACK_EXPANSION_EXTRA_ARGS (t) = save_args;
9518 /* There were no real arguments, we're just replacing a parameter
9519 pack with another version of itself. Substitute into the
9520 pattern and return a PACK_EXPANSION_*. The caller will need to
9522 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
9523 t = tsubst_expr (pattern, args, complain, in_decl,
9524 /*integral_constant_expression_p=*/false);
9526 t = tsubst (pattern, args, complain, in_decl);
9527 t = make_pack_expansion (t);
9532 /* We could not find any argument packs that work. */
9534 return error_mark_node;
9536 if (need_local_specializations)
9538 /* We're in a late-specified return type, so create our own local
9539 specializations table; the current table is either NULL or (in the
9540 case of recursive unification) might have bindings that we don't
9541 want to use or alter. */
9542 saved_local_specializations = local_specializations;
9543 local_specializations = htab_create (37,
9544 hash_local_specialization,
9545 eq_local_specializations,
9549 /* For each argument in each argument pack, substitute into the
9551 result = make_tree_vec (len);
9552 for (i = 0; i < len; ++i)
9554 /* For parameter pack, change the substitution of the parameter
9555 pack to the ith argument in its argument pack, then expand
9557 for (pack = packs; pack; pack = TREE_CHAIN (pack))
9559 tree parm = TREE_PURPOSE (pack);
9562 /* Select the Ith argument from the pack. */
9563 if (TREE_CODE (parm) == PARM_DECL)
9567 arg = make_node (ARGUMENT_PACK_SELECT);
9568 ARGUMENT_PACK_SELECT_FROM_PACK (arg) = TREE_VALUE (pack);
9570 register_local_specialization (arg, parm);
9573 arg = retrieve_local_specialization (parm);
9578 template_parm_level_and_index (parm, &level, &idx);
9582 arg = make_node (ARGUMENT_PACK_SELECT);
9583 ARGUMENT_PACK_SELECT_FROM_PACK (arg) = TREE_VALUE (pack);
9584 /* Update the corresponding argument. */
9585 TMPL_ARG (args, level, idx) = arg;
9588 /* Re-use the ARGUMENT_PACK_SELECT. */
9589 arg = TMPL_ARG (args, level, idx);
9591 ARGUMENT_PACK_SELECT_INDEX (arg) = i;
9594 /* Substitute into the PATTERN with the altered arguments. */
9595 if (!TYPE_P (pattern))
9596 TREE_VEC_ELT (result, i) =
9597 tsubst_expr (pattern, args, complain, in_decl,
9598 /*integral_constant_expression_p=*/false);
9600 TREE_VEC_ELT (result, i) = tsubst (pattern, args, complain, in_decl);
9602 if (TREE_VEC_ELT (result, i) == error_mark_node)
9604 result = error_mark_node;
9609 /* Update ARGS to restore the substitution from parameter packs to
9610 their argument packs. */
9611 for (pack = packs; pack; pack = TREE_CHAIN (pack))
9613 tree parm = TREE_PURPOSE (pack);
9615 if (TREE_CODE (parm) == PARM_DECL)
9616 register_local_specialization (TREE_TYPE (pack), parm);
9620 template_parm_level_and_index (parm, &level, &idx);
9622 /* Update the corresponding argument. */
9623 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
9624 TREE_VEC_ELT (TREE_VEC_ELT (args, level -1 ), idx) =
9627 TREE_VEC_ELT (args, idx) = TREE_TYPE (pack);
9631 if (need_local_specializations)
9633 htab_delete (local_specializations);
9634 local_specializations = saved_local_specializations;
9640 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
9641 TMPL. We do this using DECL_PARM_INDEX, which should work even with
9642 parameter packs; all parms generated from a function parameter pack will
9643 have the same DECL_PARM_INDEX. */
9646 get_pattern_parm (tree parm, tree tmpl)
9648 tree pattern = DECL_TEMPLATE_RESULT (tmpl);
9651 if (DECL_ARTIFICIAL (parm))
9653 for (patparm = DECL_ARGUMENTS (pattern);
9654 patparm; patparm = DECL_CHAIN (patparm))
9655 if (DECL_ARTIFICIAL (patparm)
9656 && DECL_NAME (parm) == DECL_NAME (patparm))
9661 patparm = FUNCTION_FIRST_USER_PARM (DECL_TEMPLATE_RESULT (tmpl));
9662 patparm = chain_index (DECL_PARM_INDEX (parm)-1, patparm);
9663 gcc_assert (DECL_PARM_INDEX (patparm)
9664 == DECL_PARM_INDEX (parm));
9670 /* Substitute ARGS into the vector or list of template arguments T. */
9673 tsubst_template_args (tree t, tree args, tsubst_flags_t complain, tree in_decl)
9676 int len, need_new = 0, i, expanded_len_adjust = 0, out;
9679 if (t == error_mark_node)
9680 return error_mark_node;
9682 len = TREE_VEC_LENGTH (t);
9683 elts = XALLOCAVEC (tree, len);
9685 for (i = 0; i < len; i++)
9687 tree orig_arg = TREE_VEC_ELT (t, i);
9690 if (TREE_CODE (orig_arg) == TREE_VEC)
9691 new_arg = tsubst_template_args (orig_arg, args, complain, in_decl);
9692 else if (PACK_EXPANSION_P (orig_arg))
9694 /* Substitute into an expansion expression. */
9695 new_arg = tsubst_pack_expansion (orig_arg, args, complain, in_decl);
9697 if (TREE_CODE (new_arg) == TREE_VEC)
9698 /* Add to the expanded length adjustment the number of
9699 expanded arguments. We subtract one from this
9700 measurement, because the argument pack expression
9701 itself is already counted as 1 in
9702 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
9703 the argument pack is empty. */
9704 expanded_len_adjust += TREE_VEC_LENGTH (new_arg) - 1;
9706 else if (ARGUMENT_PACK_P (orig_arg))
9708 /* Substitute into each of the arguments. */
9709 new_arg = TYPE_P (orig_arg)
9710 ? cxx_make_type (TREE_CODE (orig_arg))
9711 : make_node (TREE_CODE (orig_arg));
9713 SET_ARGUMENT_PACK_ARGS (
9715 tsubst_template_args (ARGUMENT_PACK_ARGS (orig_arg),
9716 args, complain, in_decl));
9718 if (ARGUMENT_PACK_ARGS (new_arg) == error_mark_node)
9719 new_arg = error_mark_node;
9721 if (TREE_CODE (new_arg) == NONTYPE_ARGUMENT_PACK) {
9722 TREE_TYPE (new_arg) = tsubst (TREE_TYPE (orig_arg), args,
9724 TREE_CONSTANT (new_arg) = TREE_CONSTANT (orig_arg);
9726 if (TREE_TYPE (new_arg) == error_mark_node)
9727 new_arg = error_mark_node;
9731 new_arg = tsubst_template_arg (orig_arg, args, complain, in_decl);
9733 if (new_arg == error_mark_node)
9734 return error_mark_node;
9737 if (new_arg != orig_arg)
9744 /* Make space for the expanded arguments coming from template
9746 t = make_tree_vec (len + expanded_len_adjust);
9747 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
9748 arguments for a member template.
9749 In that case each TREE_VEC in ORIG_T represents a level of template
9750 arguments, and ORIG_T won't carry any non defaulted argument count.
9751 It will rather be the nested TREE_VECs that will carry one.
9752 In other words, ORIG_T carries a non defaulted argument count only
9753 if it doesn't contain any nested TREE_VEC. */
9754 if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t))
9756 int count = GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t);
9757 count += expanded_len_adjust;
9758 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (t, count);
9760 for (i = 0, out = 0; i < len; i++)
9762 if ((PACK_EXPANSION_P (TREE_VEC_ELT (orig_t, i))
9763 || ARGUMENT_PACK_P (TREE_VEC_ELT (orig_t, i)))
9764 && TREE_CODE (elts[i]) == TREE_VEC)
9768 /* Now expand the template argument pack "in place". */
9769 for (idx = 0; idx < TREE_VEC_LENGTH (elts[i]); idx++, out++)
9770 TREE_VEC_ELT (t, out) = TREE_VEC_ELT (elts[i], idx);
9774 TREE_VEC_ELT (t, out) = elts[i];
9782 /* Return the result of substituting ARGS into the template parameters
9783 given by PARMS. If there are m levels of ARGS and m + n levels of
9784 PARMS, then the result will contain n levels of PARMS. For
9785 example, if PARMS is `template <class T> template <class U>
9786 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
9787 result will be `template <int*, double, class V>'. */
9790 tsubst_template_parms (tree parms, tree args, tsubst_flags_t complain)
9795 /* When substituting into a template, we must set
9796 PROCESSING_TEMPLATE_DECL as the template parameters may be
9797 dependent if they are based on one-another, and the dependency
9798 predicates are short-circuit outside of templates. */
9799 ++processing_template_decl;
9801 for (new_parms = &r;
9802 TMPL_PARMS_DEPTH (parms) > TMPL_ARGS_DEPTH (args);
9803 new_parms = &(TREE_CHAIN (*new_parms)),
9804 parms = TREE_CHAIN (parms))
9807 make_tree_vec (TREE_VEC_LENGTH (TREE_VALUE (parms)));
9810 for (i = 0; i < TREE_VEC_LENGTH (new_vec); ++i)
9814 if (parms == error_mark_node)
9817 tuple = TREE_VEC_ELT (TREE_VALUE (parms), i);
9819 if (tuple == error_mark_node)
9822 TREE_VEC_ELT (new_vec, i) =
9823 tsubst_template_parm (tuple, args, complain);
9827 tree_cons (size_int (TMPL_PARMS_DEPTH (parms)
9828 - TMPL_ARGS_DEPTH (args)),
9829 new_vec, NULL_TREE);
9832 --processing_template_decl;
9837 /* Return the result of substituting ARGS into one template parameter
9838 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
9839 parameter and which TREE_PURPOSE is the default argument of the
9840 template parameter. */
9843 tsubst_template_parm (tree t, tree args, tsubst_flags_t complain)
9845 tree default_value, parm_decl;
9847 if (args == NULL_TREE
9849 || t == error_mark_node)
9852 gcc_assert (TREE_CODE (t) == TREE_LIST);
9854 default_value = TREE_PURPOSE (t);
9855 parm_decl = TREE_VALUE (t);
9857 parm_decl = tsubst (parm_decl, args, complain, NULL_TREE);
9858 if (TREE_CODE (parm_decl) == PARM_DECL
9859 && invalid_nontype_parm_type_p (TREE_TYPE (parm_decl), complain))
9860 parm_decl = error_mark_node;
9861 default_value = tsubst_template_arg (default_value, args,
9862 complain, NULL_TREE);
9864 return build_tree_list (default_value, parm_decl);
9867 /* Substitute the ARGS into the indicated aggregate (or enumeration)
9868 type T. If T is not an aggregate or enumeration type, it is
9869 handled as if by tsubst. IN_DECL is as for tsubst. If
9870 ENTERING_SCOPE is nonzero, T is the context for a template which
9871 we are presently tsubst'ing. Return the substituted value. */
9874 tsubst_aggr_type (tree t,
9876 tsubst_flags_t complain,
9883 switch (TREE_CODE (t))
9886 if (TYPE_PTRMEMFUNC_P (t))
9887 return tsubst (TYPE_PTRMEMFUNC_FN_TYPE (t), args, complain, in_decl);
9889 /* Else fall through. */
9892 if (TYPE_TEMPLATE_INFO (t) && uses_template_parms (t))
9897 int saved_unevaluated_operand;
9898 int saved_inhibit_evaluation_warnings;
9900 /* In "sizeof(X<I>)" we need to evaluate "I". */
9901 saved_unevaluated_operand = cp_unevaluated_operand;
9902 cp_unevaluated_operand = 0;
9903 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
9904 c_inhibit_evaluation_warnings = 0;
9906 /* First, determine the context for the type we are looking
9908 context = TYPE_CONTEXT (t);
9909 if (context && TYPE_P (context))
9911 context = tsubst_aggr_type (context, args, complain,
9912 in_decl, /*entering_scope=*/1);
9913 /* If context is a nested class inside a class template,
9914 it may still need to be instantiated (c++/33959). */
9915 context = complete_type (context);
9918 /* Then, figure out what arguments are appropriate for the
9919 type we are trying to find. For example, given:
9921 template <class T> struct S;
9922 template <class T, class U> void f(T, U) { S<U> su; }
9924 and supposing that we are instantiating f<int, double>,
9925 then our ARGS will be {int, double}, but, when looking up
9926 S we only want {double}. */
9927 argvec = tsubst_template_args (TYPE_TI_ARGS (t), args,
9929 if (argvec == error_mark_node)
9930 r = error_mark_node;
9933 r = lookup_template_class (t, argvec, in_decl, context,
9934 entering_scope, complain);
9935 r = cp_build_qualified_type_real (r, cp_type_quals (t), complain);
9938 cp_unevaluated_operand = saved_unevaluated_operand;
9939 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
9944 /* This is not a template type, so there's nothing to do. */
9948 return tsubst (t, args, complain, in_decl);
9952 /* Substitute into the default argument ARG (a default argument for
9953 FN), which has the indicated TYPE. */
9956 tsubst_default_argument (tree fn, tree type, tree arg)
9958 tree saved_class_ptr = NULL_TREE;
9959 tree saved_class_ref = NULL_TREE;
9961 /* This can happen in invalid code. */
9962 if (TREE_CODE (arg) == DEFAULT_ARG)
9965 /* This default argument came from a template. Instantiate the
9966 default argument here, not in tsubst. In the case of
9975 we must be careful to do name lookup in the scope of S<T>,
9976 rather than in the current class. */
9977 push_access_scope (fn);
9978 /* The "this" pointer is not valid in a default argument. */
9981 saved_class_ptr = current_class_ptr;
9982 cp_function_chain->x_current_class_ptr = NULL_TREE;
9983 saved_class_ref = current_class_ref;
9984 cp_function_chain->x_current_class_ref = NULL_TREE;
9987 push_deferring_access_checks(dk_no_deferred);
9988 /* The default argument expression may cause implicitly defined
9989 member functions to be synthesized, which will result in garbage
9990 collection. We must treat this situation as if we were within
9991 the body of function so as to avoid collecting live data on the
9994 arg = tsubst_expr (arg, DECL_TI_ARGS (fn),
9995 tf_warning_or_error, NULL_TREE,
9996 /*integral_constant_expression_p=*/false);
9998 pop_deferring_access_checks();
10000 /* Restore the "this" pointer. */
10003 cp_function_chain->x_current_class_ptr = saved_class_ptr;
10004 cp_function_chain->x_current_class_ref = saved_class_ref;
10007 /* Make sure the default argument is reasonable. */
10008 arg = check_default_argument (type, arg);
10010 pop_access_scope (fn);
10015 /* Substitute into all the default arguments for FN. */
10018 tsubst_default_arguments (tree fn)
10023 tmpl_args = DECL_TI_ARGS (fn);
10025 /* If this function is not yet instantiated, we certainly don't need
10026 its default arguments. */
10027 if (uses_template_parms (tmpl_args))
10029 /* Don't do this again for clones. */
10030 if (DECL_CLONED_FUNCTION_P (fn))
10033 for (arg = TYPE_ARG_TYPES (TREE_TYPE (fn));
10035 arg = TREE_CHAIN (arg))
10036 if (TREE_PURPOSE (arg))
10037 TREE_PURPOSE (arg) = tsubst_default_argument (fn,
10039 TREE_PURPOSE (arg));
10042 /* Substitute the ARGS into the T, which is a _DECL. Return the
10043 result of the substitution. Issue error and warning messages under
10044 control of COMPLAIN. */
10047 tsubst_decl (tree t, tree args, tsubst_flags_t complain)
10049 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
10050 location_t saved_loc;
10051 tree r = NULL_TREE;
10053 hashval_t hash = 0;
10055 /* Set the filename and linenumber to improve error-reporting. */
10056 saved_loc = input_location;
10057 input_location = DECL_SOURCE_LOCATION (t);
10059 switch (TREE_CODE (t))
10061 case TEMPLATE_DECL:
10063 /* We can get here when processing a member function template,
10064 member class template, or template template parameter. */
10065 tree decl = DECL_TEMPLATE_RESULT (t);
10070 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
10072 /* Template template parameter is treated here. */
10073 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10074 if (new_type == error_mark_node)
10075 RETURN (error_mark_node);
10078 DECL_CHAIN (r) = NULL_TREE;
10079 TREE_TYPE (r) = new_type;
10080 DECL_TEMPLATE_RESULT (r)
10081 = build_decl (DECL_SOURCE_LOCATION (decl),
10082 TYPE_DECL, DECL_NAME (decl), new_type);
10083 DECL_TEMPLATE_PARMS (r)
10084 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
10086 TYPE_NAME (new_type) = r;
10090 /* We might already have an instance of this template.
10091 The ARGS are for the surrounding class type, so the
10092 full args contain the tsubst'd args for the context,
10093 plus the innermost args from the template decl. */
10094 tmpl_args = DECL_CLASS_TEMPLATE_P (t)
10095 ? CLASSTYPE_TI_ARGS (TREE_TYPE (t))
10096 : DECL_TI_ARGS (DECL_TEMPLATE_RESULT (t));
10097 /* Because this is a template, the arguments will still be
10098 dependent, even after substitution. If
10099 PROCESSING_TEMPLATE_DECL is not set, the dependency
10100 predicates will short-circuit. */
10101 ++processing_template_decl;
10102 full_args = tsubst_template_args (tmpl_args, args,
10103 complain, in_decl);
10104 --processing_template_decl;
10105 if (full_args == error_mark_node)
10106 RETURN (error_mark_node);
10108 /* If this is a default template template argument,
10109 tsubst might not have changed anything. */
10110 if (full_args == tmpl_args)
10113 hash = hash_tmpl_and_args (t, full_args);
10114 spec = retrieve_specialization (t, full_args, hash);
10115 if (spec != NULL_TREE)
10121 /* Make a new template decl. It will be similar to the
10122 original, but will record the current template arguments.
10123 We also create a new function declaration, which is just
10124 like the old one, but points to this new template, rather
10125 than the old one. */
10127 gcc_assert (DECL_LANG_SPECIFIC (r) != 0);
10128 DECL_CHAIN (r) = NULL_TREE;
10130 DECL_TEMPLATE_INFO (r) = build_template_info (t, args);
10132 if (TREE_CODE (decl) == TYPE_DECL
10133 && !TYPE_DECL_ALIAS_P (decl))
10136 ++processing_template_decl;
10137 new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10138 --processing_template_decl;
10139 if (new_type == error_mark_node)
10140 RETURN (error_mark_node);
10142 TREE_TYPE (r) = new_type;
10143 CLASSTYPE_TI_TEMPLATE (new_type) = r;
10144 DECL_TEMPLATE_RESULT (r) = TYPE_MAIN_DECL (new_type);
10145 DECL_TI_ARGS (r) = CLASSTYPE_TI_ARGS (new_type);
10146 DECL_CONTEXT (r) = TYPE_CONTEXT (new_type);
10151 ++processing_template_decl;
10152 new_decl = tsubst (decl, args, complain, in_decl);
10153 --processing_template_decl;
10154 if (new_decl == error_mark_node)
10155 RETURN (error_mark_node);
10157 DECL_TEMPLATE_RESULT (r) = new_decl;
10158 DECL_TI_TEMPLATE (new_decl) = r;
10159 TREE_TYPE (r) = TREE_TYPE (new_decl);
10160 DECL_TI_ARGS (r) = DECL_TI_ARGS (new_decl);
10161 DECL_CONTEXT (r) = DECL_CONTEXT (new_decl);
10164 SET_DECL_IMPLICIT_INSTANTIATION (r);
10165 DECL_TEMPLATE_INSTANTIATIONS (r) = NULL_TREE;
10166 DECL_TEMPLATE_SPECIALIZATIONS (r) = NULL_TREE;
10168 /* The template parameters for this new template are all the
10169 template parameters for the old template, except the
10170 outermost level of parameters. */
10171 DECL_TEMPLATE_PARMS (r)
10172 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
10175 if (PRIMARY_TEMPLATE_P (t))
10176 DECL_PRIMARY_TEMPLATE (r) = r;
10178 if (TREE_CODE (decl) != TYPE_DECL)
10179 /* Record this non-type partial instantiation. */
10180 register_specialization (r, t,
10181 DECL_TI_ARGS (DECL_TEMPLATE_RESULT (r)),
10186 case FUNCTION_DECL:
10189 tree argvec = NULL_TREE;
10197 /* Nobody should be tsubst'ing into non-template functions. */
10198 gcc_assert (DECL_TEMPLATE_INFO (t) != NULL_TREE);
10200 if (TREE_CODE (DECL_TI_TEMPLATE (t)) == TEMPLATE_DECL)
10205 /* If T is not dependent, just return it. We have to
10206 increment PROCESSING_TEMPLATE_DECL because
10207 value_dependent_expression_p assumes that nothing is
10208 dependent when PROCESSING_TEMPLATE_DECL is zero. */
10209 ++processing_template_decl;
10210 dependent_p = value_dependent_expression_p (t);
10211 --processing_template_decl;
10215 /* Calculate the most general template of which R is a
10216 specialization, and the complete set of arguments used to
10218 gen_tmpl = most_general_template (DECL_TI_TEMPLATE (t));
10219 argvec = tsubst_template_args (DECL_TI_ARGS
10220 (DECL_TEMPLATE_RESULT
10221 (DECL_TI_TEMPLATE (t))),
10222 args, complain, in_decl);
10223 if (argvec == error_mark_node)
10224 RETURN (error_mark_node);
10226 /* Check to see if we already have this specialization. */
10227 hash = hash_tmpl_and_args (gen_tmpl, argvec);
10228 spec = retrieve_specialization (gen_tmpl, argvec, hash);
10236 /* We can see more levels of arguments than parameters if
10237 there was a specialization of a member template, like
10240 template <class T> struct S { template <class U> void f(); }
10241 template <> template <class U> void S<int>::f(U);
10243 Here, we'll be substituting into the specialization,
10244 because that's where we can find the code we actually
10245 want to generate, but we'll have enough arguments for
10246 the most general template.
10248 We also deal with the peculiar case:
10250 template <class T> struct S {
10251 template <class U> friend void f();
10253 template <class U> void f() {}
10255 template void f<double>();
10257 Here, the ARGS for the instantiation of will be {int,
10258 double}. But, we only need as many ARGS as there are
10259 levels of template parameters in CODE_PATTERN. We are
10260 careful not to get fooled into reducing the ARGS in
10263 template <class T> struct S { template <class U> void f(U); }
10264 template <class T> template <> void S<T>::f(int) {}
10266 which we can spot because the pattern will be a
10267 specialization in this case. */
10268 args_depth = TMPL_ARGS_DEPTH (args);
10270 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (t)));
10271 if (args_depth > parms_depth
10272 && !DECL_TEMPLATE_SPECIALIZATION (t))
10273 args = get_innermost_template_args (args, parms_depth);
10277 /* This special case arises when we have something like this:
10279 template <class T> struct S {
10280 friend void f<int>(int, double);
10283 Here, the DECL_TI_TEMPLATE for the friend declaration
10284 will be an IDENTIFIER_NODE. We are being called from
10285 tsubst_friend_function, and we want only to create a
10286 new decl (R) with appropriate types so that we can call
10287 determine_specialization. */
10288 gen_tmpl = NULL_TREE;
10291 if (DECL_CLASS_SCOPE_P (t))
10293 if (DECL_NAME (t) == constructor_name (DECL_CONTEXT (t)))
10297 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args,
10298 complain, t, /*entering_scope=*/1);
10303 ctx = DECL_CONTEXT (t);
10305 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10306 if (type == error_mark_node)
10307 RETURN (error_mark_node);
10309 /* We do NOT check for matching decls pushed separately at this
10310 point, as they may not represent instantiations of this
10311 template, and in any case are considered separate under the
10314 DECL_USE_TEMPLATE (r) = 0;
10315 TREE_TYPE (r) = type;
10316 /* Clear out the mangled name and RTL for the instantiation. */
10317 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
10318 SET_DECL_RTL (r, NULL);
10319 /* Leave DECL_INITIAL set on deleted instantiations. */
10320 if (!DECL_DELETED_FN (r))
10321 DECL_INITIAL (r) = NULL_TREE;
10322 DECL_CONTEXT (r) = ctx;
10324 if (member && DECL_CONV_FN_P (r))
10325 /* Type-conversion operator. Reconstruct the name, in
10326 case it's the name of one of the template's parameters. */
10327 DECL_NAME (r) = mangle_conv_op_name_for_type (TREE_TYPE (type));
10329 DECL_ARGUMENTS (r) = tsubst (DECL_ARGUMENTS (t), args,
10331 DECL_RESULT (r) = NULL_TREE;
10333 TREE_STATIC (r) = 0;
10334 TREE_PUBLIC (r) = TREE_PUBLIC (t);
10335 DECL_EXTERNAL (r) = 1;
10336 /* If this is an instantiation of a function with internal
10337 linkage, we already know what object file linkage will be
10338 assigned to the instantiation. */
10339 DECL_INTERFACE_KNOWN (r) = !TREE_PUBLIC (r);
10340 DECL_DEFER_OUTPUT (r) = 0;
10341 DECL_CHAIN (r) = NULL_TREE;
10342 DECL_PENDING_INLINE_INFO (r) = 0;
10343 DECL_PENDING_INLINE_P (r) = 0;
10344 DECL_SAVED_TREE (r) = NULL_TREE;
10345 DECL_STRUCT_FUNCTION (r) = NULL;
10347 /* We'll re-clone as appropriate in instantiate_template. */
10348 DECL_CLONED_FUNCTION (r) = NULL_TREE;
10350 /* If we aren't complaining now, return on error before we register
10351 the specialization so that we'll complain eventually. */
10352 if ((complain & tf_error) == 0
10353 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
10354 && !grok_op_properties (r, /*complain=*/false))
10355 RETURN (error_mark_node);
10357 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
10358 this in the special friend case mentioned above where
10359 GEN_TMPL is NULL. */
10362 DECL_TEMPLATE_INFO (r)
10363 = build_template_info (gen_tmpl, argvec);
10364 SET_DECL_IMPLICIT_INSTANTIATION (r);
10365 register_specialization (r, gen_tmpl, argvec, false, hash);
10367 /* We're not supposed to instantiate default arguments
10368 until they are called, for a template. But, for a
10371 template <class T> void f ()
10372 { extern void g(int i = T()); }
10374 we should do the substitution when the template is
10375 instantiated. We handle the member function case in
10376 instantiate_class_template since the default arguments
10377 might refer to other members of the class. */
10379 && !PRIMARY_TEMPLATE_P (gen_tmpl)
10380 && !uses_template_parms (argvec))
10381 tsubst_default_arguments (r);
10384 DECL_TEMPLATE_INFO (r) = NULL_TREE;
10386 /* Copy the list of befriending classes. */
10387 for (friends = &DECL_BEFRIENDING_CLASSES (r);
10389 friends = &TREE_CHAIN (*friends))
10391 *friends = copy_node (*friends);
10392 TREE_VALUE (*friends) = tsubst (TREE_VALUE (*friends),
10397 if (DECL_CONSTRUCTOR_P (r) || DECL_DESTRUCTOR_P (r))
10399 maybe_retrofit_in_chrg (r);
10400 if (DECL_CONSTRUCTOR_P (r))
10401 grok_ctor_properties (ctx, r);
10402 /* If this is an instantiation of a member template, clone it.
10403 If it isn't, that'll be handled by
10404 clone_constructors_and_destructors. */
10405 if (PRIMARY_TEMPLATE_P (gen_tmpl))
10406 clone_function_decl (r, /*update_method_vec_p=*/0);
10408 else if ((complain & tf_error) != 0
10409 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
10410 && !grok_op_properties (r, /*complain=*/true))
10411 RETURN (error_mark_node);
10413 if (DECL_FRIEND_P (t) && DECL_FRIEND_CONTEXT (t))
10414 SET_DECL_FRIEND_CONTEXT (r,
10415 tsubst (DECL_FRIEND_CONTEXT (t),
10416 args, complain, in_decl));
10418 /* Possibly limit visibility based on template args. */
10419 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
10420 if (DECL_VISIBILITY_SPECIFIED (t))
10422 DECL_VISIBILITY_SPECIFIED (r) = 0;
10423 DECL_ATTRIBUTES (r)
10424 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
10426 determine_visibility (r);
10427 if (DECL_DEFAULTED_OUTSIDE_CLASS_P (r)
10428 && !processing_template_decl)
10429 defaulted_late_check (r);
10431 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
10432 args, complain, in_decl);
10438 tree type = NULL_TREE;
10440 tree expanded_types = NULL_TREE;
10441 tree prev_r = NULL_TREE;
10442 tree first_r = NULL_TREE;
10444 if (FUNCTION_PARAMETER_PACK_P (t))
10446 /* If there is a local specialization that isn't a
10447 parameter pack, it means that we're doing a "simple"
10448 substitution from inside tsubst_pack_expansion. Just
10449 return the local specialization (which will be a single
10451 tree spec = retrieve_local_specialization (t);
10453 && TREE_CODE (spec) == PARM_DECL
10454 && TREE_CODE (TREE_TYPE (spec)) != TYPE_PACK_EXPANSION)
10457 /* Expand the TYPE_PACK_EXPANSION that provides the types for
10458 the parameters in this function parameter pack. */
10459 expanded_types = tsubst_pack_expansion (TREE_TYPE (t), args,
10460 complain, in_decl);
10461 if (TREE_CODE (expanded_types) == TREE_VEC)
10463 len = TREE_VEC_LENGTH (expanded_types);
10465 /* Zero-length parameter packs are boring. Just substitute
10468 RETURN (tsubst (TREE_CHAIN (t), args, complain,
10473 /* All we did was update the type. Make a note of that. */
10474 type = expanded_types;
10475 expanded_types = NULL_TREE;
10479 /* Loop through all of the parameter's we'll build. When T is
10480 a function parameter pack, LEN is the number of expanded
10481 types in EXPANDED_TYPES; otherwise, LEN is 1. */
10483 for (i = 0; i < len; ++i)
10487 if (DECL_TEMPLATE_PARM_P (t))
10488 SET_DECL_TEMPLATE_PARM_P (r);
10490 if (expanded_types)
10491 /* We're on the Ith parameter of the function parameter
10494 /* An argument of a function parameter pack is not a parameter
10496 FUNCTION_PARAMETER_PACK_P (r) = false;
10498 /* Get the Ith type. */
10499 type = TREE_VEC_ELT (expanded_types, i);
10502 /* Rename the parameter to include the index. */
10504 make_ith_pack_parameter_name (DECL_NAME (r), i);
10507 /* We're dealing with a normal parameter. */
10508 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10510 type = type_decays_to (type);
10511 TREE_TYPE (r) = type;
10512 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
10514 if (DECL_INITIAL (r))
10516 if (TREE_CODE (DECL_INITIAL (r)) != TEMPLATE_PARM_INDEX)
10517 DECL_INITIAL (r) = TREE_TYPE (r);
10519 DECL_INITIAL (r) = tsubst (DECL_INITIAL (r), args,
10520 complain, in_decl);
10523 DECL_CONTEXT (r) = NULL_TREE;
10525 if (!DECL_TEMPLATE_PARM_P (r))
10526 DECL_ARG_TYPE (r) = type_passed_as (type);
10528 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
10529 args, complain, in_decl);
10531 /* Keep track of the first new parameter we
10532 generate. That's what will be returned to the
10537 /* Build a proper chain of parameters when substituting
10538 into a function parameter pack. */
10540 DECL_CHAIN (prev_r) = r;
10543 if (DECL_CHAIN (t))
10544 DECL_CHAIN (r) = tsubst (DECL_CHAIN (t), args,
10545 complain, DECL_CHAIN (t));
10547 /* FIRST_R contains the start of the chain we've built. */
10557 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10558 if (type == error_mark_node)
10559 RETURN (error_mark_node);
10560 TREE_TYPE (r) = type;
10561 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
10563 if (DECL_C_BIT_FIELD (r))
10564 /* For bit-fields, DECL_INITIAL gives the number of bits. For
10565 non-bit-fields DECL_INITIAL is a non-static data member
10566 initializer, which gets deferred instantiation. */
10568 = tsubst_expr (DECL_INITIAL (t), args,
10570 /*integral_constant_expression_p=*/true);
10571 else if (DECL_INITIAL (t))
10573 /* Set up DECL_TEMPLATE_INFO so that we can get at the
10574 NSDMI in perform_member_init. Still set DECL_INITIAL
10575 so that we know there is one. */
10576 DECL_INITIAL (r) = void_zero_node;
10577 gcc_assert (DECL_LANG_SPECIFIC (r) == NULL);
10578 retrofit_lang_decl (r);
10579 DECL_TEMPLATE_INFO (r) = build_template_info (t, args);
10581 /* We don't have to set DECL_CONTEXT here; it is set by
10582 finish_member_declaration. */
10583 DECL_CHAIN (r) = NULL_TREE;
10584 if (VOID_TYPE_P (type))
10585 error ("instantiation of %q+D as type %qT", r, type);
10587 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
10588 args, complain, in_decl);
10593 /* We reach here only for member using decls. We also need to check
10594 uses_template_parms because DECL_DEPENDENT_P is not set for a
10595 using-declaration that designates a member of the current
10596 instantiation (c++/53549). */
10597 if (DECL_DEPENDENT_P (t)
10598 || uses_template_parms (USING_DECL_SCOPE (t)))
10600 r = do_class_using_decl
10601 (tsubst_copy (USING_DECL_SCOPE (t), args, complain, in_decl),
10602 tsubst_copy (DECL_NAME (t), args, complain, in_decl));
10604 r = error_mark_node;
10607 TREE_PROTECTED (r) = TREE_PROTECTED (t);
10608 TREE_PRIVATE (r) = TREE_PRIVATE (t);
10614 DECL_CHAIN (r) = NULL_TREE;
10621 tree argvec = NULL_TREE;
10622 tree gen_tmpl = NULL_TREE;
10624 tree tmpl = NULL_TREE;
10626 tree type = NULL_TREE;
10629 if (TREE_CODE (t) == TYPE_DECL
10630 && t == TYPE_MAIN_DECL (TREE_TYPE (t)))
10632 /* If this is the canonical decl, we don't have to
10633 mess with instantiations, and often we can't (for
10634 typename, template type parms and such). Note that
10635 TYPE_NAME is not correct for the above test if
10636 we've copied the type for a typedef. */
10637 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10638 if (type == error_mark_node)
10639 RETURN (error_mark_node);
10640 r = TYPE_NAME (type);
10644 /* Check to see if we already have the specialization we
10647 if (DECL_CLASS_SCOPE_P (t) || DECL_NAMESPACE_SCOPE_P (t))
10649 /* T is a static data member or namespace-scope entity.
10650 We have to substitute into namespace-scope variables
10651 (even though such entities are never templates) because
10654 template <class T> void f() { extern T t; }
10656 where the entity referenced is not known until
10657 instantiation time. */
10659 ctx = DECL_CONTEXT (t);
10660 if (DECL_CLASS_SCOPE_P (t))
10662 ctx = tsubst_aggr_type (ctx, args,
10664 in_decl, /*entering_scope=*/1);
10665 /* If CTX is unchanged, then T is in fact the
10666 specialization we want. That situation occurs when
10667 referencing a static data member within in its own
10668 class. We can use pointer equality, rather than
10669 same_type_p, because DECL_CONTEXT is always
10671 if (ctx == DECL_CONTEXT (t)
10672 && (TREE_CODE (t) != TYPE_DECL
10673 /* ... unless T is a member template; in which
10674 case our caller can be willing to create a
10675 specialization of that template represented
10677 || !(DECL_TI_TEMPLATE (t)
10678 && DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (t)))))
10684 tmpl = DECL_TI_TEMPLATE (t);
10685 gen_tmpl = most_general_template (tmpl);
10686 argvec = tsubst (DECL_TI_ARGS (t), args, complain, in_decl);
10687 if (argvec == error_mark_node)
10688 RETURN (error_mark_node);
10689 hash = hash_tmpl_and_args (gen_tmpl, argvec);
10690 spec = retrieve_specialization (gen_tmpl, argvec, hash);
10695 /* A local variable. */
10697 /* Subsequent calls to pushdecl will fill this in. */
10699 spec = retrieve_local_specialization (t);
10701 /* If we already have the specialization we need, there is
10702 nothing more to do. */
10709 if (TREE_CODE (t) == VAR_DECL && DECL_ANON_UNION_VAR_P (t))
10711 /* Just use name lookup to find a member alias for an anonymous
10712 union, but then add it to the hash table. */
10713 r = lookup_name (DECL_NAME (t));
10714 gcc_assert (DECL_ANON_UNION_VAR_P (r));
10715 register_local_specialization (r, t);
10719 /* Create a new node for the specialization we need. */
10721 if (type == NULL_TREE)
10723 if (is_typedef_decl (t))
10724 type = DECL_ORIGINAL_TYPE (t);
10726 type = TREE_TYPE (t);
10727 if (TREE_CODE (t) == VAR_DECL
10728 && VAR_HAD_UNKNOWN_BOUND (t)
10729 && type != error_mark_node)
10730 type = strip_array_domain (type);
10731 type = tsubst (type, args, complain, in_decl);
10733 if (TREE_CODE (r) == VAR_DECL)
10735 /* Even if the original location is out of scope, the
10736 newly substituted one is not. */
10737 DECL_DEAD_FOR_LOCAL (r) = 0;
10738 DECL_INITIALIZED_P (r) = 0;
10739 DECL_TEMPLATE_INSTANTIATED (r) = 0;
10740 if (type == error_mark_node)
10741 RETURN (error_mark_node);
10742 if (TREE_CODE (type) == FUNCTION_TYPE)
10744 /* It may seem that this case cannot occur, since:
10749 declares a function, not a variable. However:
10752 template <typename T> void g() { T t; }
10753 template void g<f>();
10755 is an attempt to declare a variable with function
10757 error ("variable %qD has function type",
10758 /* R is not yet sufficiently initialized, so we
10759 just use its name. */
10761 RETURN (error_mark_node);
10763 type = complete_type (type);
10764 /* Wait until cp_finish_decl to set this again, to handle
10765 circular dependency (template/instantiate6.C). */
10766 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r) = 0;
10767 type = check_var_type (DECL_NAME (r), type);
10769 if (DECL_HAS_VALUE_EXPR_P (t))
10771 tree ve = DECL_VALUE_EXPR (t);
10772 ve = tsubst_expr (ve, args, complain, in_decl,
10773 /*constant_expression_p=*/false);
10774 if (REFERENCE_REF_P (ve))
10776 gcc_assert (TREE_CODE (type) == REFERENCE_TYPE);
10777 ve = TREE_OPERAND (ve, 0);
10779 SET_DECL_VALUE_EXPR (r, ve);
10782 else if (DECL_SELF_REFERENCE_P (t))
10783 SET_DECL_SELF_REFERENCE_P (r);
10784 TREE_TYPE (r) = type;
10785 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
10786 DECL_CONTEXT (r) = ctx;
10787 /* Clear out the mangled name and RTL for the instantiation. */
10788 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
10789 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
10790 SET_DECL_RTL (r, NULL);
10791 /* The initializer must not be expanded until it is required;
10792 see [temp.inst]. */
10793 DECL_INITIAL (r) = NULL_TREE;
10794 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
10795 SET_DECL_RTL (r, NULL);
10796 DECL_SIZE (r) = DECL_SIZE_UNIT (r) = 0;
10797 if (TREE_CODE (r) == VAR_DECL)
10799 /* Possibly limit visibility based on template args. */
10800 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
10801 if (DECL_VISIBILITY_SPECIFIED (t))
10803 DECL_VISIBILITY_SPECIFIED (r) = 0;
10804 DECL_ATTRIBUTES (r)
10805 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
10807 determine_visibility (r);
10812 /* A static data member declaration is always marked
10813 external when it is declared in-class, even if an
10814 initializer is present. We mimic the non-template
10815 processing here. */
10816 DECL_EXTERNAL (r) = 1;
10818 register_specialization (r, gen_tmpl, argvec, false, hash);
10819 DECL_TEMPLATE_INFO (r) = build_template_info (tmpl, argvec);
10820 SET_DECL_IMPLICIT_INSTANTIATION (r);
10822 else if (cp_unevaluated_operand)
10824 /* We're substituting this var in a decltype outside of its
10825 scope, such as for a lambda return type. Don't add it to
10826 local_specializations, do perform auto deduction. */
10827 tree auto_node = type_uses_auto (type);
10831 = tsubst_expr (DECL_INITIAL (t), args, complain, in_decl,
10832 /*constant_expression_p=*/false);
10833 init = resolve_nondeduced_context (init);
10834 TREE_TYPE (r) = type
10835 = do_auto_deduction (type, init, auto_node);
10839 register_local_specialization (r, t);
10841 DECL_CHAIN (r) = NULL_TREE;
10843 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r),
10845 args, complain, in_decl);
10847 /* Preserve a typedef that names a type. */
10848 if (is_typedef_decl (r))
10850 DECL_ORIGINAL_TYPE (r) = NULL_TREE;
10851 set_underlying_type (r);
10854 layout_decl (r, 0);
10859 gcc_unreachable ();
10864 /* Restore the file and line information. */
10865 input_location = saved_loc;
10870 /* Substitute into the ARG_TYPES of a function type. */
10873 tsubst_arg_types (tree arg_types,
10875 tsubst_flags_t complain,
10878 tree remaining_arg_types;
10879 tree type = NULL_TREE;
10881 tree expanded_args = NULL_TREE;
10884 if (!arg_types || arg_types == void_list_node)
10887 remaining_arg_types = tsubst_arg_types (TREE_CHAIN (arg_types),
10888 args, complain, in_decl);
10889 if (remaining_arg_types == error_mark_node)
10890 return error_mark_node;
10892 if (PACK_EXPANSION_P (TREE_VALUE (arg_types)))
10894 /* For a pack expansion, perform substitution on the
10895 entire expression. Later on, we'll handle the arguments
10897 expanded_args = tsubst_pack_expansion (TREE_VALUE (arg_types),
10898 args, complain, in_decl);
10900 if (TREE_CODE (expanded_args) == TREE_VEC)
10901 /* So that we'll spin through the parameters, one by one. */
10902 i = TREE_VEC_LENGTH (expanded_args);
10905 /* We only partially substituted into the parameter
10906 pack. Our type is TYPE_PACK_EXPANSION. */
10907 type = expanded_args;
10908 expanded_args = NULL_TREE;
10916 type = TREE_VEC_ELT (expanded_args, i);
10918 type = tsubst (TREE_VALUE (arg_types), args, complain, in_decl);
10920 if (type == error_mark_node)
10921 return error_mark_node;
10922 if (VOID_TYPE_P (type))
10924 if (complain & tf_error)
10926 error ("invalid parameter type %qT", type);
10928 error ("in declaration %q+D", in_decl);
10930 return error_mark_node;
10933 /* Do array-to-pointer, function-to-pointer conversion, and ignore
10934 top-level qualifiers as required. */
10935 type = cv_unqualified (type_decays_to (type));
10937 /* We do not substitute into default arguments here. The standard
10938 mandates that they be instantiated only when needed, which is
10939 done in build_over_call. */
10940 default_arg = TREE_PURPOSE (arg_types);
10942 if (default_arg && TREE_CODE (default_arg) == DEFAULT_ARG)
10944 /* We've instantiated a template before its default arguments
10945 have been parsed. This can happen for a nested template
10946 class, and is not an error unless we require the default
10947 argument in a call of this function. */
10948 remaining_arg_types =
10949 tree_cons (default_arg, type, remaining_arg_types);
10950 VEC_safe_push (tree, gc, DEFARG_INSTANTIATIONS (default_arg),
10951 remaining_arg_types);
10954 remaining_arg_types =
10955 hash_tree_cons (default_arg, type, remaining_arg_types);
10958 return remaining_arg_types;
10961 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
10962 *not* handle the exception-specification for FNTYPE, because the
10963 initial substitution of explicitly provided template parameters
10964 during argument deduction forbids substitution into the
10965 exception-specification:
10969 All references in the function type of the function template to the
10970 corresponding template parameters are replaced by the specified tem-
10971 plate argument values. If a substitution in a template parameter or
10972 in the function type of the function template results in an invalid
10973 type, type deduction fails. [Note: The equivalent substitution in
10974 exception specifications is done only when the function is instanti-
10975 ated, at which point a program is ill-formed if the substitution
10976 results in an invalid type.] */
10979 tsubst_function_type (tree t,
10981 tsubst_flags_t complain,
10988 /* The TYPE_CONTEXT is not used for function/method types. */
10989 gcc_assert (TYPE_CONTEXT (t) == NULL_TREE);
10991 /* Substitute the return type. */
10992 return_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10993 if (return_type == error_mark_node)
10994 return error_mark_node;
10995 /* The standard does not presently indicate that creation of a
10996 function type with an invalid return type is a deduction failure.
10997 However, that is clearly analogous to creating an array of "void"
10998 or a reference to a reference. This is core issue #486. */
10999 if (TREE_CODE (return_type) == ARRAY_TYPE
11000 || TREE_CODE (return_type) == FUNCTION_TYPE)
11002 if (complain & tf_error)
11004 if (TREE_CODE (return_type) == ARRAY_TYPE)
11005 error ("function returning an array");
11007 error ("function returning a function");
11009 return error_mark_node;
11012 /* Substitute the argument types. */
11013 arg_types = tsubst_arg_types (TYPE_ARG_TYPES (t), args,
11014 complain, in_decl);
11015 if (arg_types == error_mark_node)
11016 return error_mark_node;
11018 /* Construct a new type node and return it. */
11019 if (TREE_CODE (t) == FUNCTION_TYPE)
11021 fntype = build_function_type (return_type, arg_types);
11022 fntype = apply_memfn_quals (fntype, type_memfn_quals (t));
11026 tree r = TREE_TYPE (TREE_VALUE (arg_types));
11027 if (! MAYBE_CLASS_TYPE_P (r))
11031 Type deduction may fail for any of the following
11034 -- Attempting to create "pointer to member of T" when T
11035 is not a class type. */
11036 if (complain & tf_error)
11037 error ("creating pointer to member function of non-class type %qT",
11039 return error_mark_node;
11042 fntype = build_method_type_directly (r, return_type,
11043 TREE_CHAIN (arg_types));
11045 fntype = cp_build_type_attribute_variant (fntype, TYPE_ATTRIBUTES (t));
11050 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
11051 ARGS into that specification, and return the substituted
11052 specification. If there is no specification, return NULL_TREE. */
11055 tsubst_exception_specification (tree fntype,
11057 tsubst_flags_t complain,
11064 specs = TYPE_RAISES_EXCEPTIONS (fntype);
11065 new_specs = NULL_TREE;
11066 if (specs && TREE_PURPOSE (specs))
11068 /* A noexcept-specifier. */
11069 tree expr = TREE_PURPOSE (specs);
11070 if (expr == boolean_true_node || expr == boolean_false_node)
11074 /* Defer instantiation of noexcept-specifiers to avoid
11075 excessive instantiations (c++/49107). */
11076 new_specs = make_node (DEFERRED_NOEXCEPT);
11077 if (DEFERRED_NOEXCEPT_SPEC_P (specs))
11079 /* We already partially instantiated this member template,
11080 so combine the new args with the old. */
11081 DEFERRED_NOEXCEPT_PATTERN (new_specs)
11082 = DEFERRED_NOEXCEPT_PATTERN (expr);
11083 DEFERRED_NOEXCEPT_ARGS (new_specs)
11084 = add_to_template_args (DEFERRED_NOEXCEPT_ARGS (expr), args);
11088 DEFERRED_NOEXCEPT_PATTERN (new_specs) = expr;
11089 DEFERRED_NOEXCEPT_ARGS (new_specs) = args;
11093 new_specs = tsubst_copy_and_build
11094 (expr, args, complain, in_decl, /*function_p=*/false,
11095 /*integral_constant_expression_p=*/true);
11096 new_specs = build_noexcept_spec (new_specs, complain);
11100 if (! TREE_VALUE (specs))
11107 tree expanded_specs = NULL_TREE;
11109 if (PACK_EXPANSION_P (TREE_VALUE (specs)))
11111 /* Expand the pack expansion type. */
11112 expanded_specs = tsubst_pack_expansion (TREE_VALUE (specs),
11116 if (expanded_specs == error_mark_node)
11117 return error_mark_node;
11118 else if (TREE_CODE (expanded_specs) == TREE_VEC)
11119 len = TREE_VEC_LENGTH (expanded_specs);
11122 /* We're substituting into a member template, so
11123 we got a TYPE_PACK_EXPANSION back. Add that
11124 expansion and move on. */
11125 gcc_assert (TREE_CODE (expanded_specs)
11126 == TYPE_PACK_EXPANSION);
11127 new_specs = add_exception_specifier (new_specs,
11130 specs = TREE_CHAIN (specs);
11135 for (i = 0; i < len; ++i)
11137 if (expanded_specs)
11138 spec = TREE_VEC_ELT (expanded_specs, i);
11140 spec = tsubst (TREE_VALUE (specs), args, complain, in_decl);
11141 if (spec == error_mark_node)
11143 new_specs = add_exception_specifier (new_specs, spec,
11147 specs = TREE_CHAIN (specs);
11153 /* Take the tree structure T and replace template parameters used
11154 therein with the argument vector ARGS. IN_DECL is an associated
11155 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
11156 Issue error and warning messages under control of COMPLAIN. Note
11157 that we must be relatively non-tolerant of extensions here, in
11158 order to preserve conformance; if we allow substitutions that
11159 should not be allowed, we may allow argument deductions that should
11160 not succeed, and therefore report ambiguous overload situations
11161 where there are none. In theory, we could allow the substitution,
11162 but indicate that it should have failed, and allow our caller to
11163 make sure that the right thing happens, but we don't try to do this
11166 This function is used for dealing with types, decls and the like;
11167 for expressions, use tsubst_expr or tsubst_copy. */
11170 tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl)
11172 enum tree_code code;
11173 tree type, r = NULL_TREE;
11175 if (t == NULL_TREE || t == error_mark_node
11176 || t == integer_type_node
11177 || t == void_type_node
11178 || t == char_type_node
11179 || t == unknown_type_node
11180 || TREE_CODE (t) == NAMESPACE_DECL
11181 || TREE_CODE (t) == TRANSLATION_UNIT_DECL)
11185 return tsubst_decl (t, args, complain);
11187 if (args == NULL_TREE)
11190 code = TREE_CODE (t);
11192 if (code == IDENTIFIER_NODE)
11193 type = IDENTIFIER_TYPE_VALUE (t);
11195 type = TREE_TYPE (t);
11197 gcc_assert (type != unknown_type_node);
11199 /* Reuse typedefs. We need to do this to handle dependent attributes,
11200 such as attribute aligned. */
11202 && typedef_variant_p (t))
11204 tree decl = TYPE_NAME (t);
11206 if (TYPE_DECL_ALIAS_P (decl)
11207 && DECL_LANG_SPECIFIC (decl)
11208 && DECL_TEMPLATE_INFO (decl)
11209 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (decl)))
11211 /* DECL represents an alias template and we want to
11212 instantiate it. Let's substitute our arguments for the
11213 template parameters into the declaration and get the
11215 r = tsubst (decl, args, complain, decl);
11217 else if (DECL_CLASS_SCOPE_P (decl)
11218 && CLASSTYPE_TEMPLATE_INFO (DECL_CONTEXT (decl))
11219 && uses_template_parms (DECL_CONTEXT (decl)))
11221 tree tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
11222 tree gen_args = tsubst (DECL_TI_ARGS (decl), args, complain, in_decl);
11223 r = retrieve_specialization (tmpl, gen_args, 0);
11225 else if (DECL_FUNCTION_SCOPE_P (decl)
11226 && DECL_TEMPLATE_INFO (DECL_CONTEXT (decl))
11227 && uses_template_parms (DECL_TI_ARGS (DECL_CONTEXT (decl))))
11228 r = retrieve_local_specialization (decl);
11230 /* The typedef is from a non-template context. */
11236 r = cp_build_qualified_type_real
11237 (r, cp_type_quals (t) | cp_type_quals (r),
11238 complain | tf_ignore_bad_quals);
11242 /* We don't have an instantiation yet, so drop the typedef. */
11243 t = DECL_ORIGINAL_TYPE (decl);
11247 && code != TYPENAME_TYPE
11248 && code != TEMPLATE_TYPE_PARM
11249 && code != IDENTIFIER_NODE
11250 && code != FUNCTION_TYPE
11251 && code != METHOD_TYPE)
11252 type = tsubst (type, args, complain, in_decl);
11253 if (type == error_mark_node)
11254 return error_mark_node;
11260 case ENUMERAL_TYPE:
11261 return tsubst_aggr_type (t, args, complain, in_decl,
11262 /*entering_scope=*/0);
11265 case IDENTIFIER_NODE:
11276 if (t == integer_type_node)
11279 if (TREE_CODE (TYPE_MIN_VALUE (t)) == INTEGER_CST
11280 && TREE_CODE (TYPE_MAX_VALUE (t)) == INTEGER_CST)
11284 tree max, omax = TREE_OPERAND (TYPE_MAX_VALUE (t), 0);
11286 max = tsubst_expr (omax, args, complain, in_decl,
11287 /*integral_constant_expression_p=*/false);
11289 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
11291 if (TREE_CODE (max) == NOP_EXPR
11292 && TREE_SIDE_EFFECTS (omax)
11293 && !TREE_TYPE (max))
11294 TREE_TYPE (max) = TREE_TYPE (TREE_OPERAND (max, 0));
11296 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
11297 with TREE_SIDE_EFFECTS that indicates this is not an integral
11298 constant expression. */
11299 if (processing_template_decl
11300 && TREE_SIDE_EFFECTS (omax) && TREE_CODE (omax) == NOP_EXPR)
11302 gcc_assert (TREE_CODE (max) == NOP_EXPR);
11303 TREE_SIDE_EFFECTS (max) = 1;
11306 return compute_array_index_type (NULL_TREE, max, complain);
11309 case TEMPLATE_TYPE_PARM:
11310 case TEMPLATE_TEMPLATE_PARM:
11311 case BOUND_TEMPLATE_TEMPLATE_PARM:
11312 case TEMPLATE_PARM_INDEX:
11317 tree arg = NULL_TREE;
11321 gcc_assert (TREE_VEC_LENGTH (args) > 0);
11322 template_parm_level_and_index (t, &level, &idx);
11324 levels = TMPL_ARGS_DEPTH (args);
11325 if (level <= levels)
11327 arg = TMPL_ARG (args, level, idx);
11329 if (arg && TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
11330 /* See through ARGUMENT_PACK_SELECT arguments. */
11331 arg = ARGUMENT_PACK_SELECT_ARG (arg);
11334 if (arg == error_mark_node)
11335 return error_mark_node;
11336 else if (arg != NULL_TREE)
11338 if (ARGUMENT_PACK_P (arg))
11339 /* If ARG is an argument pack, we don't actually want to
11340 perform a substitution here, because substitutions
11341 for argument packs are only done
11342 element-by-element. We can get to this point when
11343 substituting the type of a non-type template
11344 parameter pack, when that type actually contains
11345 template parameter packs from an outer template, e.g.,
11347 template<typename... Types> struct A {
11348 template<Types... Values> struct B { };
11352 if (code == TEMPLATE_TYPE_PARM)
11355 gcc_assert (TYPE_P (arg));
11357 quals = cp_type_quals (arg) | cp_type_quals (t);
11359 return cp_build_qualified_type_real
11360 (arg, quals, complain | tf_ignore_bad_quals);
11362 else if (code == BOUND_TEMPLATE_TEMPLATE_PARM)
11364 /* We are processing a type constructed from a
11365 template template parameter. */
11366 tree argvec = tsubst (TYPE_TI_ARGS (t),
11367 args, complain, in_decl);
11368 if (argvec == error_mark_node)
11369 return error_mark_node;
11371 gcc_assert (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
11372 || TREE_CODE (arg) == TEMPLATE_DECL
11373 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE);
11375 if (TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE)
11376 /* Consider this code:
11378 template <template <class> class Template>
11380 template <class Arg> using Bind = Template<Arg>;
11383 template <template <class> class Template, class Arg>
11384 using Instantiate = Template<Arg>; //#0
11386 template <template <class> class Template,
11389 Instantiate<Internal<Template>::template Bind,
11392 When #1 is parsed, the
11393 BOUND_TEMPLATE_TEMPLATE_PARM representing the
11394 parameter `Template' in #0 matches the
11395 UNBOUND_CLASS_TEMPLATE representing the argument
11396 `Internal<Template>::template Bind'; We then want
11397 to assemble the type `Bind<Argument>' that can't
11398 be fully created right now, because
11399 `Internal<Template>' not being complete, the Bind
11400 template cannot be looked up in that context. So
11401 we need to "store" `Bind<Argument>' for later
11402 when the context of Bind becomes complete. Let's
11403 store that in a TYPENAME_TYPE. */
11404 return make_typename_type (TYPE_CONTEXT (arg),
11405 build_nt (TEMPLATE_ID_EXPR,
11406 TYPE_IDENTIFIER (arg),
11411 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
11412 are resolving nested-types in the signature of a
11413 member function templates. Otherwise ARG is a
11414 TEMPLATE_DECL and is the real template to be
11416 if (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
11417 arg = TYPE_NAME (arg);
11419 r = lookup_template_class (arg,
11421 DECL_CONTEXT (arg),
11422 /*entering_scope=*/0,
11424 return cp_build_qualified_type_real
11425 (r, cp_type_quals (t), complain);
11428 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
11429 return convert_from_reference (unshare_expr (arg));
11433 /* This can happen during the attempted tsubst'ing in
11434 unify. This means that we don't yet have any information
11435 about the template parameter in question. */
11438 /* If we get here, we must have been looking at a parm for a
11439 more deeply nested template. Make a new version of this
11440 template parameter, but with a lower level. */
11443 case TEMPLATE_TYPE_PARM:
11444 case TEMPLATE_TEMPLATE_PARM:
11445 case BOUND_TEMPLATE_TEMPLATE_PARM:
11446 if (cp_type_quals (t))
11448 r = tsubst (TYPE_MAIN_VARIANT (t), args, complain, in_decl);
11449 r = cp_build_qualified_type_real
11450 (r, cp_type_quals (t),
11451 complain | (code == TEMPLATE_TYPE_PARM
11452 ? tf_ignore_bad_quals : 0));
11457 TEMPLATE_TYPE_PARM_INDEX (r)
11458 = reduce_template_parm_level (TEMPLATE_TYPE_PARM_INDEX (t),
11459 r, levels, args, complain);
11460 TYPE_STUB_DECL (r) = TYPE_NAME (r) = TEMPLATE_TYPE_DECL (r);
11461 TYPE_MAIN_VARIANT (r) = r;
11462 TYPE_POINTER_TO (r) = NULL_TREE;
11463 TYPE_REFERENCE_TO (r) = NULL_TREE;
11465 if (TREE_CODE (r) == TEMPLATE_TEMPLATE_PARM)
11466 /* We have reduced the level of the template
11467 template parameter, but not the levels of its
11468 template parameters, so canonical_type_parameter
11469 will not be able to find the canonical template
11470 template parameter for this level. Thus, we
11471 require structural equality checking to compare
11472 TEMPLATE_TEMPLATE_PARMs. */
11473 SET_TYPE_STRUCTURAL_EQUALITY (r);
11474 else if (TYPE_STRUCTURAL_EQUALITY_P (t))
11475 SET_TYPE_STRUCTURAL_EQUALITY (r);
11477 TYPE_CANONICAL (r) = canonical_type_parameter (r);
11479 if (code == BOUND_TEMPLATE_TEMPLATE_PARM)
11481 tree argvec = tsubst (TYPE_TI_ARGS (t), args,
11482 complain, in_decl);
11483 if (argvec == error_mark_node)
11484 return error_mark_node;
11486 TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (r)
11487 = build_template_info (TYPE_TI_TEMPLATE (t), argvec);
11492 case TEMPLATE_PARM_INDEX:
11493 r = reduce_template_parm_level (t, type, levels, args, complain);
11497 gcc_unreachable ();
11505 tree purpose, value, chain;
11507 if (t == void_list_node)
11510 purpose = TREE_PURPOSE (t);
11513 purpose = tsubst (purpose, args, complain, in_decl);
11514 if (purpose == error_mark_node)
11515 return error_mark_node;
11517 value = TREE_VALUE (t);
11520 value = tsubst (value, args, complain, in_decl);
11521 if (value == error_mark_node)
11522 return error_mark_node;
11524 chain = TREE_CHAIN (t);
11525 if (chain && chain != void_type_node)
11527 chain = tsubst (chain, args, complain, in_decl);
11528 if (chain == error_mark_node)
11529 return error_mark_node;
11531 if (purpose == TREE_PURPOSE (t)
11532 && value == TREE_VALUE (t)
11533 && chain == TREE_CHAIN (t))
11535 return hash_tree_cons (purpose, value, chain);
11539 /* We should never be tsubsting a binfo. */
11540 gcc_unreachable ();
11543 /* A vector of template arguments. */
11544 gcc_assert (!type);
11545 return tsubst_template_args (t, args, complain, in_decl);
11548 case REFERENCE_TYPE:
11550 if (type == TREE_TYPE (t) && TREE_CODE (type) != METHOD_TYPE)
11555 Type deduction may fail for any of the following
11558 -- Attempting to create a pointer to reference type.
11559 -- Attempting to create a reference to a reference type or
11560 a reference to void.
11562 Core issue 106 says that creating a reference to a reference
11563 during instantiation is no longer a cause for failure. We
11564 only enforce this check in strict C++98 mode. */
11565 if ((TREE_CODE (type) == REFERENCE_TYPE
11566 && (((cxx_dialect == cxx98) && flag_iso) || code != REFERENCE_TYPE))
11567 || (code == REFERENCE_TYPE && TREE_CODE (type) == VOID_TYPE))
11569 static location_t last_loc;
11571 /* We keep track of the last time we issued this error
11572 message to avoid spewing a ton of messages during a
11573 single bad template instantiation. */
11574 if (complain & tf_error
11575 && last_loc != input_location)
11577 if (TREE_CODE (type) == VOID_TYPE)
11578 error ("forming reference to void");
11579 else if (code == POINTER_TYPE)
11580 error ("forming pointer to reference type %qT", type);
11582 error ("forming reference to reference type %qT", type);
11583 last_loc = input_location;
11586 return error_mark_node;
11588 else if (code == POINTER_TYPE)
11590 r = build_pointer_type (type);
11591 if (TREE_CODE (type) == METHOD_TYPE)
11592 r = build_ptrmemfunc_type (r);
11594 else if (TREE_CODE (type) == REFERENCE_TYPE)
11595 /* In C++0x, during template argument substitution, when there is an
11596 attempt to create a reference to a reference type, reference
11597 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
11599 "If a template-argument for a template-parameter T names a type
11600 that is a reference to a type A, an attempt to create the type
11601 'lvalue reference to cv T' creates the type 'lvalue reference to
11602 A,' while an attempt to create the type type rvalue reference to
11603 cv T' creates the type T"
11605 r = cp_build_reference_type
11607 TYPE_REF_IS_RVALUE (t) && TYPE_REF_IS_RVALUE (type));
11609 r = cp_build_reference_type (type, TYPE_REF_IS_RVALUE (t));
11610 r = cp_build_qualified_type_real (r, cp_type_quals (t), complain);
11612 if (r != error_mark_node)
11613 /* Will this ever be needed for TYPE_..._TO values? */
11620 r = tsubst (TYPE_OFFSET_BASETYPE (t), args, complain, in_decl);
11621 if (r == error_mark_node || !MAYBE_CLASS_TYPE_P (r))
11625 Type deduction may fail for any of the following
11628 -- Attempting to create "pointer to member of T" when T
11629 is not a class type. */
11630 if (complain & tf_error)
11631 error ("creating pointer to member of non-class type %qT", r);
11632 return error_mark_node;
11634 if (TREE_CODE (type) == REFERENCE_TYPE)
11636 if (complain & tf_error)
11637 error ("creating pointer to member reference type %qT", type);
11638 return error_mark_node;
11640 if (TREE_CODE (type) == VOID_TYPE)
11642 if (complain & tf_error)
11643 error ("creating pointer to member of type void");
11644 return error_mark_node;
11646 gcc_assert (TREE_CODE (type) != METHOD_TYPE);
11647 if (TREE_CODE (type) == FUNCTION_TYPE)
11649 /* The type of the implicit object parameter gets its
11650 cv-qualifiers from the FUNCTION_TYPE. */
11652 tree method_type = build_memfn_type (type, r, type_memfn_quals (type));
11653 memptr = build_ptrmemfunc_type (build_pointer_type (method_type));
11654 return cp_build_qualified_type_real (memptr, cp_type_quals (t),
11658 return cp_build_qualified_type_real (build_ptrmem_type (r, type),
11662 case FUNCTION_TYPE:
11667 fntype = tsubst_function_type (t, args, complain, in_decl);
11668 if (fntype == error_mark_node)
11669 return error_mark_node;
11671 /* Substitute the exception specification. */
11672 specs = tsubst_exception_specification (t, args, complain,
11673 in_decl, /*defer_ok*/true);
11674 if (specs == error_mark_node)
11675 return error_mark_node;
11677 fntype = build_exception_variant (fntype, specs);
11682 tree domain = tsubst (TYPE_DOMAIN (t), args, complain, in_decl);
11683 if (domain == error_mark_node)
11684 return error_mark_node;
11686 /* As an optimization, we avoid regenerating the array type if
11687 it will obviously be the same as T. */
11688 if (type == TREE_TYPE (t) && domain == TYPE_DOMAIN (t))
11691 /* These checks should match the ones in grokdeclarator.
11695 The deduction may fail for any of the following reasons:
11697 -- Attempting to create an array with an element type that
11698 is void, a function type, or a reference type, or [DR337]
11699 an abstract class type. */
11700 if (TREE_CODE (type) == VOID_TYPE
11701 || TREE_CODE (type) == FUNCTION_TYPE
11702 || TREE_CODE (type) == REFERENCE_TYPE)
11704 if (complain & tf_error)
11705 error ("creating array of %qT", type);
11706 return error_mark_node;
11708 if (CLASS_TYPE_P (type) && CLASSTYPE_PURE_VIRTUALS (type))
11710 if (complain & tf_error)
11711 error ("creating array of %qT, which is an abstract class type",
11713 return error_mark_node;
11716 r = build_cplus_array_type (type, domain);
11718 if (TYPE_USER_ALIGN (t))
11720 TYPE_ALIGN (r) = TYPE_ALIGN (t);
11721 TYPE_USER_ALIGN (r) = 1;
11727 case TYPENAME_TYPE:
11729 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
11730 in_decl, /*entering_scope=*/1);
11731 tree f = tsubst_copy (TYPENAME_TYPE_FULLNAME (t), args,
11732 complain, in_decl);
11734 if (ctx == error_mark_node || f == error_mark_node)
11735 return error_mark_node;
11737 if (!MAYBE_CLASS_TYPE_P (ctx))
11739 if (complain & tf_error)
11740 error ("%qT is not a class, struct, or union type", ctx);
11741 return error_mark_node;
11743 else if (!uses_template_parms (ctx) && !TYPE_BEING_DEFINED (ctx))
11745 /* Normally, make_typename_type does not require that the CTX
11746 have complete type in order to allow things like:
11748 template <class T> struct S { typename S<T>::X Y; };
11750 But, such constructs have already been resolved by this
11751 point, so here CTX really should have complete type, unless
11752 it's a partial instantiation. */
11753 ctx = complete_type (ctx);
11754 if (!COMPLETE_TYPE_P (ctx))
11756 if (complain & tf_error)
11757 cxx_incomplete_type_error (NULL_TREE, ctx);
11758 return error_mark_node;
11762 f = make_typename_type (ctx, f, typename_type,
11763 (complain & tf_error) | tf_keep_type_decl);
11764 if (f == error_mark_node)
11766 if (TREE_CODE (f) == TYPE_DECL)
11768 complain |= tf_ignore_bad_quals;
11772 if (TREE_CODE (f) != TYPENAME_TYPE)
11774 if (TYPENAME_IS_ENUM_P (t) && TREE_CODE (f) != ENUMERAL_TYPE)
11776 if (complain & tf_error)
11777 error ("%qT resolves to %qT, which is not an enumeration type",
11780 return error_mark_node;
11782 else if (TYPENAME_IS_CLASS_P (t) && !CLASS_TYPE_P (f))
11784 if (complain & tf_error)
11785 error ("%qT resolves to %qT, which is is not a class type",
11788 return error_mark_node;
11792 return cp_build_qualified_type_real
11793 (f, cp_type_quals (f) | cp_type_quals (t), complain);
11796 case UNBOUND_CLASS_TEMPLATE:
11798 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
11799 in_decl, /*entering_scope=*/1);
11800 tree name = TYPE_IDENTIFIER (t);
11801 tree parm_list = DECL_TEMPLATE_PARMS (TYPE_NAME (t));
11803 if (ctx == error_mark_node || name == error_mark_node)
11804 return error_mark_node;
11807 parm_list = tsubst_template_parms (parm_list, args, complain);
11808 return make_unbound_class_template (ctx, name, parm_list, complain);
11815 ++cp_unevaluated_operand;
11816 ++c_inhibit_evaluation_warnings;
11818 type = tsubst_expr (TYPEOF_TYPE_EXPR (t), args,
11820 /*integral_constant_expression_p=*/false);
11822 --cp_unevaluated_operand;
11823 --c_inhibit_evaluation_warnings;
11825 type = finish_typeof (type);
11826 return cp_build_qualified_type_real (type,
11828 | cp_type_quals (type),
11832 case DECLTYPE_TYPE:
11836 ++cp_unevaluated_operand;
11837 ++c_inhibit_evaluation_warnings;
11839 type = tsubst_expr (DECLTYPE_TYPE_EXPR (t), args,
11841 /*integral_constant_expression_p=*/false);
11843 --cp_unevaluated_operand;
11844 --c_inhibit_evaluation_warnings;
11846 if (DECLTYPE_FOR_LAMBDA_CAPTURE (t))
11847 type = lambda_capture_field_type (type);
11848 else if (DECLTYPE_FOR_LAMBDA_PROXY (t))
11849 type = lambda_proxy_type (type);
11851 type = finish_decltype_type
11852 (type, DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t), complain);
11853 return cp_build_qualified_type_real (type,
11855 | cp_type_quals (type),
11859 case UNDERLYING_TYPE:
11861 tree type = tsubst (UNDERLYING_TYPE_TYPE (t), args,
11862 complain, in_decl);
11863 return finish_underlying_type (type);
11866 case TYPE_ARGUMENT_PACK:
11867 case NONTYPE_ARGUMENT_PACK:
11869 tree r = TYPE_P (t) ? cxx_make_type (code) : make_node (code);
11871 tsubst_template_args (ARGUMENT_PACK_ARGS (t),
11875 SET_ARGUMENT_PACK_ARGS (r, packed_out);
11877 /* For template nontype argument packs, also substitute into
11879 if (code == NONTYPE_ARGUMENT_PACK)
11880 TREE_TYPE (r) = tsubst (TREE_TYPE (t), args, complain, in_decl);
11898 /* We should use one of the expression tsubsts for these codes. */
11899 gcc_unreachable ();
11902 sorry ("use of %qs in template", tree_code_name [(int) code]);
11903 return error_mark_node;
11907 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
11908 type of the expression on the left-hand side of the "." or "->"
11912 tsubst_baselink (tree baselink, tree object_type,
11913 tree args, tsubst_flags_t complain, tree in_decl)
11916 tree qualifying_scope;
11919 tree template_args = 0;
11920 bool template_id_p = false;
11921 bool qualified = BASELINK_QUALIFIED_P (baselink);
11923 /* A baselink indicates a function from a base class. Both the
11924 BASELINK_ACCESS_BINFO and the base class referenced may
11925 indicate bases of the template class, rather than the
11926 instantiated class. In addition, lookups that were not
11927 ambiguous before may be ambiguous now. Therefore, we perform
11928 the lookup again. */
11929 qualifying_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (baselink));
11930 qualifying_scope = tsubst (qualifying_scope, args,
11931 complain, in_decl);
11932 fns = BASELINK_FUNCTIONS (baselink);
11933 optype = tsubst (BASELINK_OPTYPE (baselink), args, complain, in_decl);
11934 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
11936 template_id_p = true;
11937 template_args = TREE_OPERAND (fns, 1);
11938 fns = TREE_OPERAND (fns, 0);
11940 template_args = tsubst_template_args (template_args, args,
11941 complain, in_decl);
11943 name = DECL_NAME (get_first_fn (fns));
11944 if (IDENTIFIER_TYPENAME_P (name))
11945 name = mangle_conv_op_name_for_type (optype);
11946 baselink = lookup_fnfields (qualifying_scope, name, /*protect=*/1);
11948 return error_mark_node;
11950 /* If lookup found a single function, mark it as used at this
11951 point. (If it lookup found multiple functions the one selected
11952 later by overload resolution will be marked as used at that
11954 if (BASELINK_P (baselink))
11955 fns = BASELINK_FUNCTIONS (baselink);
11956 if (!template_id_p && !really_overloaded_fn (fns))
11957 mark_used (OVL_CURRENT (fns));
11959 /* Add back the template arguments, if present. */
11960 if (BASELINK_P (baselink) && template_id_p)
11961 BASELINK_FUNCTIONS (baselink)
11962 = build_nt (TEMPLATE_ID_EXPR,
11963 BASELINK_FUNCTIONS (baselink),
11965 /* Update the conversion operator type. */
11966 BASELINK_OPTYPE (baselink) = optype;
11969 object_type = current_class_type;
11972 baselink = adjust_result_of_qualified_name_lookup (baselink,
11978 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
11979 true if the qualified-id will be a postfix-expression in-and-of
11980 itself; false if more of the postfix-expression follows the
11981 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
11985 tsubst_qualified_id (tree qualified_id, tree args,
11986 tsubst_flags_t complain, tree in_decl,
11987 bool done, bool address_p)
11993 tree template_args;
11995 gcc_assert (TREE_CODE (qualified_id) == SCOPE_REF);
11997 /* Figure out what name to look up. */
11998 name = TREE_OPERAND (qualified_id, 1);
11999 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
12001 is_template = true;
12002 template_args = TREE_OPERAND (name, 1);
12004 template_args = tsubst_template_args (template_args, args,
12005 complain, in_decl);
12006 name = TREE_OPERAND (name, 0);
12010 is_template = false;
12011 template_args = NULL_TREE;
12014 /* Substitute into the qualifying scope. When there are no ARGS, we
12015 are just trying to simplify a non-dependent expression. In that
12016 case the qualifying scope may be dependent, and, in any case,
12017 substituting will not help. */
12018 scope = TREE_OPERAND (qualified_id, 0);
12021 scope = tsubst (scope, args, complain, in_decl);
12022 expr = tsubst_copy (name, args, complain, in_decl);
12027 if (dependent_scope_p (scope))
12030 expr = build_min_nt (TEMPLATE_ID_EXPR, expr, template_args);
12031 return build_qualified_name (NULL_TREE, scope, expr,
12032 QUALIFIED_NAME_IS_TEMPLATE (qualified_id));
12035 if (!BASELINK_P (name) && !DECL_P (expr))
12037 if (TREE_CODE (expr) == BIT_NOT_EXPR)
12039 /* A BIT_NOT_EXPR is used to represent a destructor. */
12040 if (!check_dtor_name (scope, TREE_OPERAND (expr, 0)))
12042 error ("qualifying type %qT does not match destructor name ~%qT",
12043 scope, TREE_OPERAND (expr, 0));
12044 expr = error_mark_node;
12047 expr = lookup_qualified_name (scope, complete_dtor_identifier,
12048 /*is_type_p=*/0, false);
12051 expr = lookup_qualified_name (scope, expr, /*is_type_p=*/0, false);
12052 if (TREE_CODE (TREE_CODE (expr) == TEMPLATE_DECL
12053 ? DECL_TEMPLATE_RESULT (expr) : expr) == TYPE_DECL)
12055 if (complain & tf_error)
12057 error ("dependent-name %qE is parsed as a non-type, but "
12058 "instantiation yields a type", qualified_id);
12059 inform (input_location, "say %<typename %E%> if a type is meant", qualified_id);
12061 return error_mark_node;
12067 check_accessibility_of_qualified_id (expr, /*object_type=*/NULL_TREE,
12069 /* Remember that there was a reference to this entity. */
12073 if (expr == error_mark_node || TREE_CODE (expr) == TREE_LIST)
12075 if (complain & tf_error)
12076 qualified_name_lookup_error (scope,
12077 TREE_OPERAND (qualified_id, 1),
12078 expr, input_location);
12079 return error_mark_node;
12083 expr = lookup_template_function (expr, template_args);
12085 if (expr == error_mark_node && complain & tf_error)
12086 qualified_name_lookup_error (scope, TREE_OPERAND (qualified_id, 1),
12087 expr, input_location);
12088 else if (TYPE_P (scope))
12090 expr = (adjust_result_of_qualified_name_lookup
12091 (expr, scope, current_class_type));
12092 expr = (finish_qualified_id_expr
12093 (scope, expr, done, address_p && PTRMEM_OK_P (qualified_id),
12094 QUALIFIED_NAME_IS_TEMPLATE (qualified_id),
12095 /*template_arg_p=*/false));
12098 /* Expressions do not generally have reference type. */
12099 if (TREE_CODE (expr) != SCOPE_REF
12100 /* However, if we're about to form a pointer-to-member, we just
12101 want the referenced member referenced. */
12102 && TREE_CODE (expr) != OFFSET_REF)
12103 expr = convert_from_reference (expr);
12108 /* Like tsubst, but deals with expressions. This function just replaces
12109 template parms; to finish processing the resultant expression, use
12110 tsubst_copy_and_build or tsubst_expr. */
12113 tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl)
12115 enum tree_code code;
12118 if (t == NULL_TREE || t == error_mark_node || args == NULL_TREE)
12121 code = TREE_CODE (t);
12126 r = retrieve_local_specialization (t);
12132 /* We get here for a use of 'this' in an NSDMI. */
12133 if (DECL_NAME (t) == this_identifier
12134 && at_function_scope_p ()
12135 && DECL_CONSTRUCTOR_P (current_function_decl))
12136 return current_class_ptr;
12138 /* This can happen for a parameter name used later in a function
12139 declaration (such as in a late-specified return type). Just
12140 make a dummy decl, since it's only used for its type. */
12141 gcc_assert (cp_unevaluated_operand != 0);
12142 /* We copy T because want to tsubst the PARM_DECL only,
12143 not the following PARM_DECLs that are chained to T. */
12145 r = tsubst_decl (c, args, complain);
12146 /* Give it the template pattern as its context; its true context
12147 hasn't been instantiated yet and this is good enough for
12149 DECL_CONTEXT (r) = DECL_CONTEXT (t);
12152 if (TREE_CODE (r) == ARGUMENT_PACK_SELECT)
12153 r = ARGUMENT_PACK_SELECT_ARG (r);
12162 if (DECL_TEMPLATE_PARM_P (t))
12163 return tsubst_copy (DECL_INITIAL (t), args, complain, in_decl);
12164 /* There is no need to substitute into namespace-scope
12166 if (DECL_NAMESPACE_SCOPE_P (t))
12168 /* If ARGS is NULL, then T is known to be non-dependent. */
12169 if (args == NULL_TREE)
12170 return integral_constant_value (t);
12172 /* Unfortunately, we cannot just call lookup_name here.
12175 template <int I> int f() {
12177 struct S { void g() { E e = a; } };
12180 When we instantiate f<7>::S::g(), say, lookup_name is not
12181 clever enough to find f<7>::a. */
12183 = tsubst_aggr_type (TREE_TYPE (t), args, complain, in_decl,
12184 /*entering_scope=*/0);
12186 for (v = TYPE_VALUES (enum_type);
12188 v = TREE_CHAIN (v))
12189 if (TREE_PURPOSE (v) == DECL_NAME (t))
12190 return TREE_VALUE (v);
12192 /* We didn't find the name. That should never happen; if
12193 name-lookup found it during preliminary parsing, we
12194 should find it again here during instantiation. */
12195 gcc_unreachable ();
12200 if (DECL_CONTEXT (t))
12204 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args, complain, in_decl,
12205 /*entering_scope=*/1);
12206 if (ctx != DECL_CONTEXT (t))
12208 tree r = lookup_field (ctx, DECL_NAME (t), 0, false);
12211 if (complain & tf_error)
12212 error ("using invalid field %qD", t);
12213 return error_mark_node;
12222 case FUNCTION_DECL:
12223 if ((DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t))
12224 || local_variable_p (t))
12225 t = tsubst (t, args, complain, in_decl);
12229 case NAMESPACE_DECL:
12233 /* An OVERLOAD will always be a non-dependent overload set; an
12234 overload set from function scope will just be represented with an
12235 IDENTIFIER_NODE, and from class scope with a BASELINK. */
12236 gcc_assert (!uses_template_parms (t));
12240 return tsubst_baselink (t, current_class_type, args, complain, in_decl);
12242 case TEMPLATE_DECL:
12243 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
12244 return tsubst (TREE_TYPE (DECL_TEMPLATE_RESULT (t)),
12245 args, complain, in_decl);
12246 else if (DECL_FUNCTION_TEMPLATE_P (t) && DECL_MEMBER_TEMPLATE_P (t))
12247 return tsubst (t, args, complain, in_decl);
12248 else if (DECL_CLASS_SCOPE_P (t)
12249 && uses_template_parms (DECL_CONTEXT (t)))
12251 /* Template template argument like the following example need
12254 template <template <class> class TT> struct C {};
12255 template <class T> struct D {
12256 template <class U> struct E {};
12261 We are processing the template argument `E' in #1 for
12262 the template instantiation #2. Originally, `E' is a
12263 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
12264 have to substitute this with one having context `D<int>'. */
12266 tree context = tsubst (DECL_CONTEXT (t), args, complain, in_decl);
12267 return lookup_field (context, DECL_NAME(t), 0, false);
12270 /* Ordinary template template argument. */
12274 case REINTERPRET_CAST_EXPR:
12275 case CONST_CAST_EXPR:
12276 case STATIC_CAST_EXPR:
12277 case DYNAMIC_CAST_EXPR:
12278 case IMPLICIT_CONV_EXPR:
12282 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
12283 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
12286 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
12292 ++cp_unevaluated_operand;
12293 ++c_inhibit_evaluation_warnings;
12294 /* We only want to compute the number of arguments. */
12295 expanded = tsubst_pack_expansion (TREE_OPERAND (t, 0), args,
12296 complain, in_decl);
12297 --cp_unevaluated_operand;
12298 --c_inhibit_evaluation_warnings;
12300 if (TREE_CODE (expanded) == TREE_VEC)
12301 len = TREE_VEC_LENGTH (expanded);
12303 if (expanded == error_mark_node)
12304 return error_mark_node;
12305 else if (PACK_EXPANSION_P (expanded)
12306 || (TREE_CODE (expanded) == TREE_VEC
12308 && PACK_EXPANSION_P (TREE_VEC_ELT (expanded, len-1))))
12310 if (TREE_CODE (expanded) == TREE_VEC)
12311 expanded = TREE_VEC_ELT (expanded, len - 1);
12313 if (TYPE_P (expanded))
12314 return cxx_sizeof_or_alignof_type (expanded, SIZEOF_EXPR,
12315 complain & tf_error);
12317 return cxx_sizeof_or_alignof_expr (expanded, SIZEOF_EXPR,
12318 complain & tf_error);
12321 return build_int_cst (size_type_node, len);
12327 case TRUTH_NOT_EXPR:
12330 case UNARY_PLUS_EXPR: /* Unary + */
12332 case AT_ENCODE_EXPR:
12336 case REALPART_EXPR:
12337 case IMAGPART_EXPR:
12339 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
12340 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
12342 case COMPONENT_REF:
12347 object = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
12348 name = TREE_OPERAND (t, 1);
12349 if (TREE_CODE (name) == BIT_NOT_EXPR)
12351 name = tsubst_copy (TREE_OPERAND (name, 0), args,
12352 complain, in_decl);
12353 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
12355 else if (TREE_CODE (name) == SCOPE_REF
12356 && TREE_CODE (TREE_OPERAND (name, 1)) == BIT_NOT_EXPR)
12358 tree base = tsubst_copy (TREE_OPERAND (name, 0), args,
12359 complain, in_decl);
12360 name = TREE_OPERAND (name, 1);
12361 name = tsubst_copy (TREE_OPERAND (name, 0), args,
12362 complain, in_decl);
12363 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
12364 name = build_qualified_name (/*type=*/NULL_TREE,
12366 /*template_p=*/false);
12368 else if (BASELINK_P (name))
12369 name = tsubst_baselink (name,
12370 non_reference (TREE_TYPE (object)),
12374 name = tsubst_copy (name, args, complain, in_decl);
12375 return build_nt (COMPONENT_REF, object, name, NULL_TREE);
12381 case TRUNC_DIV_EXPR:
12382 case CEIL_DIV_EXPR:
12383 case FLOOR_DIV_EXPR:
12384 case ROUND_DIV_EXPR:
12385 case EXACT_DIV_EXPR:
12389 case TRUNC_MOD_EXPR:
12390 case FLOOR_MOD_EXPR:
12391 case TRUTH_ANDIF_EXPR:
12392 case TRUTH_ORIF_EXPR:
12393 case TRUTH_AND_EXPR:
12394 case TRUTH_OR_EXPR:
12407 case COMPOUND_EXPR:
12410 case PREDECREMENT_EXPR:
12411 case PREINCREMENT_EXPR:
12412 case POSTDECREMENT_EXPR:
12413 case POSTINCREMENT_EXPR:
12415 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12416 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
12419 return build_qualified_name (/*type=*/NULL_TREE,
12420 tsubst_copy (TREE_OPERAND (t, 0),
12421 args, complain, in_decl),
12422 tsubst_copy (TREE_OPERAND (t, 1),
12423 args, complain, in_decl),
12424 QUALIFIED_NAME_IS_TEMPLATE (t));
12429 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12430 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
12431 NULL_TREE, NULL_TREE);
12435 int n = VL_EXP_OPERAND_LENGTH (t);
12436 tree result = build_vl_exp (CALL_EXPR, n);
12438 for (i = 0; i < n; i++)
12439 TREE_OPERAND (t, i) = tsubst_copy (TREE_OPERAND (t, i), args,
12440 complain, in_decl);
12446 case PSEUDO_DTOR_EXPR:
12449 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12450 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
12451 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
12452 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
12459 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12460 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
12461 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
12462 NEW_EXPR_USE_GLOBAL (r) = NEW_EXPR_USE_GLOBAL (t);
12469 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12470 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
12471 DELETE_EXPR_USE_GLOBAL (r) = DELETE_EXPR_USE_GLOBAL (t);
12472 DELETE_EXPR_USE_VEC (r) = DELETE_EXPR_USE_VEC (t);
12476 case TEMPLATE_ID_EXPR:
12478 /* Substituted template arguments */
12479 tree fn = TREE_OPERAND (t, 0);
12480 tree targs = TREE_OPERAND (t, 1);
12482 fn = tsubst_copy (fn, args, complain, in_decl);
12484 targs = tsubst_template_args (targs, args, complain, in_decl);
12486 return lookup_template_function (fn, targs);
12491 tree purpose, value, chain;
12493 if (t == void_list_node)
12496 purpose = TREE_PURPOSE (t);
12498 purpose = tsubst_copy (purpose, args, complain, in_decl);
12499 value = TREE_VALUE (t);
12501 value = tsubst_copy (value, args, complain, in_decl);
12502 chain = TREE_CHAIN (t);
12503 if (chain && chain != void_type_node)
12504 chain = tsubst_copy (chain, args, complain, in_decl);
12505 if (purpose == TREE_PURPOSE (t)
12506 && value == TREE_VALUE (t)
12507 && chain == TREE_CHAIN (t))
12509 return tree_cons (purpose, value, chain);
12514 case ENUMERAL_TYPE:
12516 case TEMPLATE_TYPE_PARM:
12517 case TEMPLATE_TEMPLATE_PARM:
12518 case BOUND_TEMPLATE_TEMPLATE_PARM:
12519 case TEMPLATE_PARM_INDEX:
12521 case REFERENCE_TYPE:
12523 case FUNCTION_TYPE:
12526 case TYPENAME_TYPE:
12527 case UNBOUND_CLASS_TEMPLATE:
12529 case DECLTYPE_TYPE:
12531 return tsubst (t, args, complain, in_decl);
12533 case IDENTIFIER_NODE:
12534 if (IDENTIFIER_TYPENAME_P (t))
12536 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12537 return mangle_conv_op_name_for_type (new_type);
12543 /* This is handled by tsubst_copy_and_build. */
12544 gcc_unreachable ();
12547 return build_x_va_arg (tsubst_copy (TREE_OPERAND (t, 0), args, complain,
12549 tsubst (TREE_TYPE (t), args, complain, in_decl));
12551 case CLEANUP_POINT_EXPR:
12552 /* We shouldn't have built any of these during initial template
12553 generation. Instead, they should be built during instantiation
12554 in response to the saved STMT_IS_FULL_EXPR_P setting. */
12555 gcc_unreachable ();
12559 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
12560 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12561 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
12562 PTRMEM_OK_P (r) = PTRMEM_OK_P (t);
12563 mark_used (TREE_OPERAND (r, 1));
12566 case EXPR_PACK_EXPANSION:
12567 error ("invalid use of pack expansion expression");
12568 return error_mark_node;
12570 case NONTYPE_ARGUMENT_PACK:
12571 error ("use %<...%> to expand argument pack");
12572 return error_mark_node;
12579 /* Instantiate any typedefs in the type. */
12580 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12581 r = fold_convert (type, t);
12582 gcc_assert (TREE_CODE (r) == code);
12587 /* These can sometimes show up in a partial instantiation, but never
12588 involve template parms. */
12589 gcc_assert (!uses_template_parms (t));
12593 /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */
12594 gcc_checking_assert (false);
12599 /* Like tsubst_copy, but specifically for OpenMP clauses. */
12602 tsubst_omp_clauses (tree clauses, tree args, tsubst_flags_t complain,
12605 tree new_clauses = NULL, nc, oc;
12607 for (oc = clauses; oc ; oc = OMP_CLAUSE_CHAIN (oc))
12609 nc = copy_node (oc);
12610 OMP_CLAUSE_CHAIN (nc) = new_clauses;
12613 switch (OMP_CLAUSE_CODE (nc))
12615 case OMP_CLAUSE_LASTPRIVATE:
12616 if (OMP_CLAUSE_LASTPRIVATE_STMT (oc))
12618 OMP_CLAUSE_LASTPRIVATE_STMT (nc) = push_stmt_list ();
12619 tsubst_expr (OMP_CLAUSE_LASTPRIVATE_STMT (oc), args, complain,
12620 in_decl, /*integral_constant_expression_p=*/false);
12621 OMP_CLAUSE_LASTPRIVATE_STMT (nc)
12622 = pop_stmt_list (OMP_CLAUSE_LASTPRIVATE_STMT (nc));
12625 case OMP_CLAUSE_PRIVATE:
12626 case OMP_CLAUSE_SHARED:
12627 case OMP_CLAUSE_FIRSTPRIVATE:
12628 case OMP_CLAUSE_REDUCTION:
12629 case OMP_CLAUSE_COPYIN:
12630 case OMP_CLAUSE_COPYPRIVATE:
12631 case OMP_CLAUSE_IF:
12632 case OMP_CLAUSE_NUM_THREADS:
12633 case OMP_CLAUSE_SCHEDULE:
12634 case OMP_CLAUSE_COLLAPSE:
12635 case OMP_CLAUSE_FINAL:
12636 OMP_CLAUSE_OPERAND (nc, 0)
12637 = tsubst_expr (OMP_CLAUSE_OPERAND (oc, 0), args, complain,
12638 in_decl, /*integral_constant_expression_p=*/false);
12640 case OMP_CLAUSE_NOWAIT:
12641 case OMP_CLAUSE_ORDERED:
12642 case OMP_CLAUSE_DEFAULT:
12643 case OMP_CLAUSE_UNTIED:
12644 case OMP_CLAUSE_MERGEABLE:
12647 gcc_unreachable ();
12651 return finish_omp_clauses (nreverse (new_clauses));
12654 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
12657 tsubst_copy_asm_operands (tree t, tree args, tsubst_flags_t complain,
12660 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
12662 tree purpose, value, chain;
12667 if (TREE_CODE (t) != TREE_LIST)
12668 return tsubst_copy_and_build (t, args, complain, in_decl,
12669 /*function_p=*/false,
12670 /*integral_constant_expression_p=*/false);
12672 if (t == void_list_node)
12675 purpose = TREE_PURPOSE (t);
12677 purpose = RECUR (purpose);
12678 value = TREE_VALUE (t);
12681 if (TREE_CODE (value) != LABEL_DECL)
12682 value = RECUR (value);
12685 value = lookup_label (DECL_NAME (value));
12686 gcc_assert (TREE_CODE (value) == LABEL_DECL);
12687 TREE_USED (value) = 1;
12690 chain = TREE_CHAIN (t);
12691 if (chain && chain != void_type_node)
12692 chain = RECUR (chain);
12693 return tree_cons (purpose, value, chain);
12697 /* Substitute one OMP_FOR iterator. */
12700 tsubst_omp_for_iterator (tree t, int i, tree declv, tree initv,
12701 tree condv, tree incrv, tree *clauses,
12702 tree args, tsubst_flags_t complain, tree in_decl,
12703 bool integral_constant_expression_p)
12705 #define RECUR(NODE) \
12706 tsubst_expr ((NODE), args, complain, in_decl, \
12707 integral_constant_expression_p)
12708 tree decl, init, cond, incr, auto_node;
12710 init = TREE_VEC_ELT (OMP_FOR_INIT (t), i);
12711 gcc_assert (TREE_CODE (init) == MODIFY_EXPR);
12712 decl = RECUR (TREE_OPERAND (init, 0));
12713 init = TREE_OPERAND (init, 1);
12714 auto_node = type_uses_auto (TREE_TYPE (decl));
12715 if (auto_node && init)
12717 tree init_expr = init;
12718 if (TREE_CODE (init_expr) == DECL_EXPR)
12719 init_expr = DECL_INITIAL (DECL_EXPR_DECL (init_expr));
12720 init_expr = RECUR (init_expr);
12722 = do_auto_deduction (TREE_TYPE (decl), init_expr, auto_node);
12724 gcc_assert (!type_dependent_expression_p (decl));
12726 if (!CLASS_TYPE_P (TREE_TYPE (decl)))
12728 cond = RECUR (TREE_VEC_ELT (OMP_FOR_COND (t), i));
12729 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
12730 if (TREE_CODE (incr) == MODIFY_EXPR)
12731 incr = build_x_modify_expr (RECUR (TREE_OPERAND (incr, 0)), NOP_EXPR,
12732 RECUR (TREE_OPERAND (incr, 1)),
12735 incr = RECUR (incr);
12736 TREE_VEC_ELT (declv, i) = decl;
12737 TREE_VEC_ELT (initv, i) = init;
12738 TREE_VEC_ELT (condv, i) = cond;
12739 TREE_VEC_ELT (incrv, i) = incr;
12743 if (init && TREE_CODE (init) != DECL_EXPR)
12746 for (c = *clauses; c ; c = OMP_CLAUSE_CHAIN (c))
12748 if ((OMP_CLAUSE_CODE (c) == OMP_CLAUSE_PRIVATE
12749 || OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LASTPRIVATE)
12750 && OMP_CLAUSE_DECL (c) == decl)
12752 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_FIRSTPRIVATE
12753 && OMP_CLAUSE_DECL (c) == decl)
12754 error ("iteration variable %qD should not be firstprivate", decl);
12755 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_REDUCTION
12756 && OMP_CLAUSE_DECL (c) == decl)
12757 error ("iteration variable %qD should not be reduction", decl);
12761 c = build_omp_clause (input_location, OMP_CLAUSE_PRIVATE);
12762 OMP_CLAUSE_DECL (c) = decl;
12763 c = finish_omp_clauses (c);
12766 OMP_CLAUSE_CHAIN (c) = *clauses;
12771 cond = TREE_VEC_ELT (OMP_FOR_COND (t), i);
12772 if (COMPARISON_CLASS_P (cond))
12773 cond = build2 (TREE_CODE (cond), boolean_type_node,
12774 RECUR (TREE_OPERAND (cond, 0)),
12775 RECUR (TREE_OPERAND (cond, 1)));
12777 cond = RECUR (cond);
12778 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
12779 switch (TREE_CODE (incr))
12781 case PREINCREMENT_EXPR:
12782 case PREDECREMENT_EXPR:
12783 case POSTINCREMENT_EXPR:
12784 case POSTDECREMENT_EXPR:
12785 incr = build2 (TREE_CODE (incr), TREE_TYPE (decl),
12786 RECUR (TREE_OPERAND (incr, 0)), NULL_TREE);
12789 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
12790 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
12792 tree rhs = TREE_OPERAND (incr, 1);
12793 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
12794 RECUR (TREE_OPERAND (incr, 0)),
12795 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
12796 RECUR (TREE_OPERAND (rhs, 0)),
12797 RECUR (TREE_OPERAND (rhs, 1))));
12800 incr = RECUR (incr);
12803 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
12804 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
12806 tree lhs = RECUR (TREE_OPERAND (incr, 0));
12807 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl), lhs,
12808 build2 (TREE_CODE (TREE_OPERAND (incr, 1)),
12809 TREE_TYPE (decl), lhs,
12810 RECUR (TREE_OPERAND (incr, 2))));
12812 else if (TREE_CODE (TREE_OPERAND (incr, 1)) == NOP_EXPR
12813 && (TREE_CODE (TREE_OPERAND (incr, 2)) == PLUS_EXPR
12814 || (TREE_CODE (TREE_OPERAND (incr, 2)) == MINUS_EXPR)))
12816 tree rhs = TREE_OPERAND (incr, 2);
12817 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
12818 RECUR (TREE_OPERAND (incr, 0)),
12819 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
12820 RECUR (TREE_OPERAND (rhs, 0)),
12821 RECUR (TREE_OPERAND (rhs, 1))));
12824 incr = RECUR (incr);
12827 incr = RECUR (incr);
12831 TREE_VEC_ELT (declv, i) = decl;
12832 TREE_VEC_ELT (initv, i) = init;
12833 TREE_VEC_ELT (condv, i) = cond;
12834 TREE_VEC_ELT (incrv, i) = incr;
12838 /* Like tsubst_copy for expressions, etc. but also does semantic
12842 tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl,
12843 bool integral_constant_expression_p)
12845 #define RECUR(NODE) \
12846 tsubst_expr ((NODE), args, complain, in_decl, \
12847 integral_constant_expression_p)
12851 if (t == NULL_TREE || t == error_mark_node)
12854 if (EXPR_HAS_LOCATION (t))
12855 input_location = EXPR_LOCATION (t);
12856 if (STATEMENT_CODE_P (TREE_CODE (t)))
12857 current_stmt_tree ()->stmts_are_full_exprs_p = STMT_IS_FULL_EXPR_P (t);
12859 switch (TREE_CODE (t))
12861 case STATEMENT_LIST:
12863 tree_stmt_iterator i;
12864 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
12865 RECUR (tsi_stmt (i));
12869 case CTOR_INITIALIZER:
12870 finish_mem_initializers (tsubst_initializer_list
12871 (TREE_OPERAND (t, 0), args));
12875 finish_return_stmt (RECUR (TREE_OPERAND (t, 0)));
12879 tmp = RECUR (EXPR_STMT_EXPR (t));
12880 if (EXPR_STMT_STMT_EXPR_RESULT (t))
12881 finish_stmt_expr_expr (tmp, cur_stmt_expr);
12883 finish_expr_stmt (tmp);
12887 do_using_directive (USING_STMT_NAMESPACE (t));
12892 tree decl, pattern_decl;
12895 pattern_decl = decl = DECL_EXPR_DECL (t);
12896 if (TREE_CODE (decl) == LABEL_DECL)
12897 finish_label_decl (DECL_NAME (decl));
12898 else if (TREE_CODE (decl) == USING_DECL)
12900 tree scope = USING_DECL_SCOPE (decl);
12901 tree name = DECL_NAME (decl);
12904 scope = tsubst (scope, args, complain, in_decl);
12905 decl = lookup_qualified_name (scope, name,
12906 /*is_type_p=*/false,
12907 /*complain=*/false);
12908 if (decl == error_mark_node || TREE_CODE (decl) == TREE_LIST)
12909 qualified_name_lookup_error (scope, name, decl, input_location);
12911 do_local_using_decl (decl, scope, name);
12915 init = DECL_INITIAL (decl);
12916 decl = tsubst (decl, args, complain, in_decl);
12917 if (decl != error_mark_node)
12919 /* By marking the declaration as instantiated, we avoid
12920 trying to instantiate it. Since instantiate_decl can't
12921 handle local variables, and since we've already done
12922 all that needs to be done, that's the right thing to
12924 if (TREE_CODE (decl) == VAR_DECL)
12925 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
12926 if (TREE_CODE (decl) == VAR_DECL
12927 && ANON_AGGR_TYPE_P (TREE_TYPE (decl)))
12928 /* Anonymous aggregates are a special case. */
12929 finish_anon_union (decl);
12930 else if (is_capture_proxy (DECL_EXPR_DECL (t)))
12932 DECL_CONTEXT (decl) = current_function_decl;
12933 insert_capture_proxy (decl);
12937 int const_init = false;
12938 maybe_push_decl (decl);
12939 if (TREE_CODE (decl) == VAR_DECL
12940 && DECL_PRETTY_FUNCTION_P (decl))
12942 /* For __PRETTY_FUNCTION__ we have to adjust the
12944 const char *const name
12945 = cxx_printable_name (current_function_decl, 2);
12946 init = cp_fname_init (name, &TREE_TYPE (decl));
12950 tree t = RECUR (init);
12954 /* If we had an initializer but it
12955 instantiated to nothing,
12956 value-initialize the object. This will
12957 only occur when the initializer was a
12958 pack expansion where the parameter packs
12959 used in that expansion were of length
12961 init = build_value_init (TREE_TYPE (decl),
12963 if (TREE_CODE (init) == AGGR_INIT_EXPR)
12964 init = get_target_expr_sfinae (init, complain);
12970 if (TREE_CODE (decl) == VAR_DECL)
12971 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
12973 cp_finish_decl (decl, init, const_init, NULL_TREE, 0);
12978 /* A DECL_EXPR can also be used as an expression, in the condition
12979 clause of an if/for/while construct. */
12984 stmt = begin_for_stmt (NULL_TREE, NULL_TREE);
12985 RECUR (FOR_INIT_STMT (t));
12986 finish_for_init_stmt (stmt);
12987 tmp = RECUR (FOR_COND (t));
12988 finish_for_cond (tmp, stmt);
12989 tmp = RECUR (FOR_EXPR (t));
12990 finish_for_expr (tmp, stmt);
12991 RECUR (FOR_BODY (t));
12992 finish_for_stmt (stmt);
12995 case RANGE_FOR_STMT:
12998 stmt = begin_for_stmt (NULL_TREE, NULL_TREE);
12999 decl = RANGE_FOR_DECL (t);
13000 decl = tsubst (decl, args, complain, in_decl);
13001 maybe_push_decl (decl);
13002 expr = RECUR (RANGE_FOR_EXPR (t));
13003 stmt = cp_convert_range_for (stmt, decl, expr);
13004 RECUR (RANGE_FOR_BODY (t));
13005 finish_for_stmt (stmt);
13010 stmt = begin_while_stmt ();
13011 tmp = RECUR (WHILE_COND (t));
13012 finish_while_stmt_cond (tmp, stmt);
13013 RECUR (WHILE_BODY (t));
13014 finish_while_stmt (stmt);
13018 stmt = begin_do_stmt ();
13019 RECUR (DO_BODY (t));
13020 finish_do_body (stmt);
13021 tmp = RECUR (DO_COND (t));
13022 finish_do_stmt (tmp, stmt);
13026 stmt = begin_if_stmt ();
13027 tmp = RECUR (IF_COND (t));
13028 finish_if_stmt_cond (tmp, stmt);
13029 RECUR (THEN_CLAUSE (t));
13030 finish_then_clause (stmt);
13032 if (ELSE_CLAUSE (t))
13034 begin_else_clause (stmt);
13035 RECUR (ELSE_CLAUSE (t));
13036 finish_else_clause (stmt);
13039 finish_if_stmt (stmt);
13043 if (BIND_EXPR_BODY_BLOCK (t))
13044 stmt = begin_function_body ();
13046 stmt = begin_compound_stmt (BIND_EXPR_TRY_BLOCK (t)
13047 ? BCS_TRY_BLOCK : 0);
13049 RECUR (BIND_EXPR_BODY (t));
13051 if (BIND_EXPR_BODY_BLOCK (t))
13052 finish_function_body (stmt);
13054 finish_compound_stmt (stmt);
13058 finish_break_stmt ();
13061 case CONTINUE_STMT:
13062 finish_continue_stmt ();
13066 stmt = begin_switch_stmt ();
13067 tmp = RECUR (SWITCH_STMT_COND (t));
13068 finish_switch_cond (tmp, stmt);
13069 RECUR (SWITCH_STMT_BODY (t));
13070 finish_switch_stmt (stmt);
13073 case CASE_LABEL_EXPR:
13074 finish_case_label (EXPR_LOCATION (t),
13075 RECUR (CASE_LOW (t)),
13076 RECUR (CASE_HIGH (t)));
13081 tree decl = LABEL_EXPR_LABEL (t);
13084 label = finish_label_stmt (DECL_NAME (decl));
13085 if (DECL_ATTRIBUTES (decl) != NULL_TREE)
13086 cplus_decl_attributes (&label, DECL_ATTRIBUTES (decl), 0);
13091 tmp = GOTO_DESTINATION (t);
13092 if (TREE_CODE (tmp) != LABEL_DECL)
13093 /* Computed goto's must be tsubst'd into. On the other hand,
13094 non-computed gotos must not be; the identifier in question
13095 will have no binding. */
13098 tmp = DECL_NAME (tmp);
13099 finish_goto_stmt (tmp);
13103 tmp = finish_asm_stmt
13104 (ASM_VOLATILE_P (t),
13105 RECUR (ASM_STRING (t)),
13106 tsubst_copy_asm_operands (ASM_OUTPUTS (t), args, complain, in_decl),
13107 tsubst_copy_asm_operands (ASM_INPUTS (t), args, complain, in_decl),
13108 tsubst_copy_asm_operands (ASM_CLOBBERS (t), args, complain, in_decl),
13109 tsubst_copy_asm_operands (ASM_LABELS (t), args, complain, in_decl));
13111 tree asm_expr = tmp;
13112 if (TREE_CODE (asm_expr) == CLEANUP_POINT_EXPR)
13113 asm_expr = TREE_OPERAND (asm_expr, 0);
13114 ASM_INPUT_P (asm_expr) = ASM_INPUT_P (t);
13121 stmt = begin_try_block ();
13122 RECUR (TRY_STMTS (t));
13123 finish_cleanup_try_block (stmt);
13124 finish_cleanup (RECUR (TRY_HANDLERS (t)), stmt);
13128 tree compound_stmt = NULL_TREE;
13130 if (FN_TRY_BLOCK_P (t))
13131 stmt = begin_function_try_block (&compound_stmt);
13133 stmt = begin_try_block ();
13135 RECUR (TRY_STMTS (t));
13137 if (FN_TRY_BLOCK_P (t))
13138 finish_function_try_block (stmt);
13140 finish_try_block (stmt);
13142 RECUR (TRY_HANDLERS (t));
13143 if (FN_TRY_BLOCK_P (t))
13144 finish_function_handler_sequence (stmt, compound_stmt);
13146 finish_handler_sequence (stmt);
13152 tree decl = HANDLER_PARMS (t);
13156 decl = tsubst (decl, args, complain, in_decl);
13157 /* Prevent instantiate_decl from trying to instantiate
13158 this variable. We've already done all that needs to be
13160 if (decl != error_mark_node)
13161 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
13163 stmt = begin_handler ();
13164 finish_handler_parms (decl, stmt);
13165 RECUR (HANDLER_BODY (t));
13166 finish_handler (stmt);
13171 tsubst (TREE_TYPE (t), args, complain, NULL_TREE);
13174 case STATIC_ASSERT:
13177 tsubst_expr (STATIC_ASSERT_CONDITION (t),
13180 /*integral_constant_expression_p=*/true);
13181 finish_static_assert (condition,
13182 STATIC_ASSERT_MESSAGE (t),
13183 STATIC_ASSERT_SOURCE_LOCATION (t),
13184 /*member_p=*/false);
13189 tmp = tsubst_omp_clauses (OMP_PARALLEL_CLAUSES (t),
13190 args, complain, in_decl);
13191 stmt = begin_omp_parallel ();
13192 RECUR (OMP_PARALLEL_BODY (t));
13193 OMP_PARALLEL_COMBINED (finish_omp_parallel (tmp, stmt))
13194 = OMP_PARALLEL_COMBINED (t);
13198 tmp = tsubst_omp_clauses (OMP_TASK_CLAUSES (t),
13199 args, complain, in_decl);
13200 stmt = begin_omp_task ();
13201 RECUR (OMP_TASK_BODY (t));
13202 finish_omp_task (tmp, stmt);
13207 tree clauses, body, pre_body;
13208 tree declv, initv, condv, incrv;
13211 clauses = tsubst_omp_clauses (OMP_FOR_CLAUSES (t),
13212 args, complain, in_decl);
13213 declv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
13214 initv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
13215 condv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
13216 incrv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
13218 for (i = 0; i < TREE_VEC_LENGTH (OMP_FOR_INIT (t)); i++)
13219 tsubst_omp_for_iterator (t, i, declv, initv, condv, incrv,
13220 &clauses, args, complain, in_decl,
13221 integral_constant_expression_p);
13223 stmt = begin_omp_structured_block ();
13225 for (i = 0; i < TREE_VEC_LENGTH (initv); i++)
13226 if (TREE_VEC_ELT (initv, i) == NULL
13227 || TREE_CODE (TREE_VEC_ELT (initv, i)) != DECL_EXPR)
13228 TREE_VEC_ELT (initv, i) = RECUR (TREE_VEC_ELT (initv, i));
13229 else if (CLASS_TYPE_P (TREE_TYPE (TREE_VEC_ELT (initv, i))))
13231 tree init = RECUR (TREE_VEC_ELT (initv, i));
13232 gcc_assert (init == TREE_VEC_ELT (declv, i));
13233 TREE_VEC_ELT (initv, i) = NULL_TREE;
13237 tree decl_expr = TREE_VEC_ELT (initv, i);
13238 tree init = DECL_INITIAL (DECL_EXPR_DECL (decl_expr));
13239 gcc_assert (init != NULL);
13240 TREE_VEC_ELT (initv, i) = RECUR (init);
13241 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = NULL;
13243 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = init;
13246 pre_body = push_stmt_list ();
13247 RECUR (OMP_FOR_PRE_BODY (t));
13248 pre_body = pop_stmt_list (pre_body);
13250 body = push_stmt_list ();
13251 RECUR (OMP_FOR_BODY (t));
13252 body = pop_stmt_list (body);
13254 t = finish_omp_for (EXPR_LOCATION (t), declv, initv, condv, incrv,
13255 body, pre_body, clauses);
13257 add_stmt (finish_omp_structured_block (stmt));
13263 tmp = tsubst_omp_clauses (OMP_CLAUSES (t), args, complain, in_decl);
13264 stmt = push_stmt_list ();
13265 RECUR (OMP_BODY (t));
13266 stmt = pop_stmt_list (stmt);
13269 OMP_BODY (t) = stmt;
13270 OMP_CLAUSES (t) = tmp;
13278 stmt = push_stmt_list ();
13279 RECUR (OMP_BODY (t));
13280 stmt = pop_stmt_list (stmt);
13283 OMP_BODY (t) = stmt;
13288 gcc_assert (OMP_ATOMIC_DEPENDENT_P (t));
13289 if (TREE_CODE (TREE_OPERAND (t, 1)) != MODIFY_EXPR)
13291 tree op1 = TREE_OPERAND (t, 1);
13292 tree rhs1 = NULL_TREE;
13294 if (TREE_CODE (op1) == COMPOUND_EXPR)
13296 rhs1 = RECUR (TREE_OPERAND (op1, 0));
13297 op1 = TREE_OPERAND (op1, 1);
13299 lhs = RECUR (TREE_OPERAND (op1, 0));
13300 rhs = RECUR (TREE_OPERAND (op1, 1));
13301 finish_omp_atomic (OMP_ATOMIC, TREE_CODE (op1), lhs, rhs,
13302 NULL_TREE, NULL_TREE, rhs1);
13306 tree op1 = TREE_OPERAND (t, 1);
13307 tree v = NULL_TREE, lhs, rhs = NULL_TREE, lhs1 = NULL_TREE;
13308 tree rhs1 = NULL_TREE;
13309 enum tree_code code = TREE_CODE (TREE_OPERAND (op1, 1));
13310 enum tree_code opcode = NOP_EXPR;
13311 if (code == OMP_ATOMIC_READ)
13313 v = RECUR (TREE_OPERAND (op1, 0));
13314 lhs = RECUR (TREE_OPERAND (TREE_OPERAND (op1, 1), 0));
13316 else if (code == OMP_ATOMIC_CAPTURE_OLD
13317 || code == OMP_ATOMIC_CAPTURE_NEW)
13319 tree op11 = TREE_OPERAND (TREE_OPERAND (op1, 1), 1);
13320 v = RECUR (TREE_OPERAND (op1, 0));
13321 lhs1 = RECUR (TREE_OPERAND (TREE_OPERAND (op1, 1), 0));
13322 if (TREE_CODE (op11) == COMPOUND_EXPR)
13324 rhs1 = RECUR (TREE_OPERAND (op11, 0));
13325 op11 = TREE_OPERAND (op11, 1);
13327 lhs = RECUR (TREE_OPERAND (op11, 0));
13328 rhs = RECUR (TREE_OPERAND (op11, 1));
13329 opcode = TREE_CODE (op11);
13334 lhs = RECUR (TREE_OPERAND (op1, 0));
13335 rhs = RECUR (TREE_OPERAND (op1, 1));
13337 finish_omp_atomic (code, opcode, lhs, rhs, v, lhs1, rhs1);
13341 case TRANSACTION_EXPR:
13344 flags |= (TRANSACTION_EXPR_OUTER (t) ? TM_STMT_ATTR_OUTER : 0);
13345 flags |= (TRANSACTION_EXPR_RELAXED (t) ? TM_STMT_ATTR_RELAXED : 0);
13347 if (TRANSACTION_EXPR_IS_STMT (t))
13349 tree body = TRANSACTION_EXPR_BODY (t);
13350 tree noex = NULL_TREE;
13351 if (TREE_CODE (body) == MUST_NOT_THROW_EXPR)
13353 noex = MUST_NOT_THROW_COND (body);
13354 if (noex == NULL_TREE)
13355 noex = boolean_true_node;
13356 body = TREE_OPERAND (body, 0);
13358 stmt = begin_transaction_stmt (input_location, NULL, flags);
13360 finish_transaction_stmt (stmt, NULL, flags, RECUR (noex));
13364 stmt = build_transaction_expr (EXPR_LOCATION (t),
13365 RECUR (TRANSACTION_EXPR_BODY (t)),
13372 case MUST_NOT_THROW_EXPR:
13373 return build_must_not_throw_expr (RECUR (TREE_OPERAND (t, 0)),
13374 RECUR (MUST_NOT_THROW_COND (t)));
13376 case EXPR_PACK_EXPANSION:
13377 error ("invalid use of pack expansion expression");
13378 return error_mark_node;
13380 case NONTYPE_ARGUMENT_PACK:
13381 error ("use %<...%> to expand argument pack");
13382 return error_mark_node;
13385 gcc_assert (!STATEMENT_CODE_P (TREE_CODE (t)));
13387 return tsubst_copy_and_build (t, args, complain, in_decl,
13388 /*function_p=*/false,
13389 integral_constant_expression_p);
13396 /* T is a postfix-expression that is not being used in a function
13397 call. Return the substituted version of T. */
13400 tsubst_non_call_postfix_expression (tree t, tree args,
13401 tsubst_flags_t complain,
13404 if (TREE_CODE (t) == SCOPE_REF)
13405 t = tsubst_qualified_id (t, args, complain, in_decl,
13406 /*done=*/false, /*address_p=*/false);
13408 t = tsubst_copy_and_build (t, args, complain, in_decl,
13409 /*function_p=*/false,
13410 /*integral_constant_expression_p=*/false);
13415 /* Like tsubst but deals with expressions and performs semantic
13416 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
13419 tsubst_copy_and_build (tree t,
13421 tsubst_flags_t complain,
13424 bool integral_constant_expression_p)
13426 #define RECUR(NODE) \
13427 tsubst_copy_and_build (NODE, args, complain, in_decl, \
13428 /*function_p=*/false, \
13429 integral_constant_expression_p)
13433 if (t == NULL_TREE || t == error_mark_node)
13436 switch (TREE_CODE (t))
13440 /* Fall through. */
13441 case IDENTIFIER_NODE:
13445 bool non_integral_constant_expression_p;
13446 const char *error_msg;
13448 if (IDENTIFIER_TYPENAME_P (t))
13450 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
13451 t = mangle_conv_op_name_for_type (new_type);
13454 /* Look up the name. */
13455 decl = lookup_name (t);
13457 /* By convention, expressions use ERROR_MARK_NODE to indicate
13458 failure, not NULL_TREE. */
13459 if (decl == NULL_TREE)
13460 decl = error_mark_node;
13462 decl = finish_id_expression (t, decl, NULL_TREE,
13464 integral_constant_expression_p,
13465 /*allow_non_integral_constant_expression_p=*/(cxx_dialect >= cxx0x),
13466 &non_integral_constant_expression_p,
13467 /*template_p=*/false,
13469 /*address_p=*/false,
13470 /*template_arg_p=*/false,
13475 if (!function_p && TREE_CODE (decl) == IDENTIFIER_NODE)
13477 if (complain & tf_error)
13478 unqualified_name_lookup_error (decl);
13479 decl = error_mark_node;
13484 case TEMPLATE_ID_EXPR:
13487 tree templ = RECUR (TREE_OPERAND (t, 0));
13488 tree targs = TREE_OPERAND (t, 1);
13491 targs = tsubst_template_args (targs, args, complain, in_decl);
13493 if (TREE_CODE (templ) == COMPONENT_REF)
13495 object = TREE_OPERAND (templ, 0);
13496 templ = TREE_OPERAND (templ, 1);
13499 object = NULL_TREE;
13500 templ = lookup_template_function (templ, targs);
13503 return build3 (COMPONENT_REF, TREE_TYPE (templ),
13504 object, templ, NULL_TREE);
13506 return baselink_for_fns (templ);
13511 tree r = RECUR (TREE_OPERAND (t, 0));
13513 if (REFERENCE_REF_P (t))
13515 /* A type conversion to reference type will be enclosed in
13516 such an indirect ref, but the substitution of the cast
13517 will have also added such an indirect ref. */
13518 if (TREE_CODE (TREE_TYPE (r)) == REFERENCE_TYPE)
13519 r = convert_from_reference (r);
13522 r = build_x_indirect_ref (r, RO_UNARY_STAR, complain);
13528 (tsubst (TREE_TYPE (t), args, complain, in_decl),
13529 RECUR (TREE_OPERAND (t, 0)));
13531 case IMPLICIT_CONV_EXPR:
13533 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
13534 tree expr = RECUR (TREE_OPERAND (t, 0));
13535 int flags = LOOKUP_IMPLICIT;
13536 if (IMPLICIT_CONV_EXPR_DIRECT_INIT (t))
13537 flags = LOOKUP_NORMAL;
13538 return perform_implicit_conversion_flags (type, expr, complain,
13545 tsubst (TREE_TYPE (t), args, complain, in_decl),
13546 RECUR (TREE_OPERAND (t, 0)));
13549 case REINTERPRET_CAST_EXPR:
13550 case CONST_CAST_EXPR:
13551 case DYNAMIC_CAST_EXPR:
13552 case STATIC_CAST_EXPR:
13557 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
13558 if (integral_constant_expression_p
13559 && !cast_valid_in_integral_constant_expression_p (type))
13561 if (complain & tf_error)
13562 error ("a cast to a type other than an integral or "
13563 "enumeration type cannot appear in a constant-expression");
13564 return error_mark_node;
13567 op = RECUR (TREE_OPERAND (t, 0));
13569 switch (TREE_CODE (t))
13572 return build_functional_cast (type, op, complain);
13573 case REINTERPRET_CAST_EXPR:
13574 return build_reinterpret_cast (type, op, complain);
13575 case CONST_CAST_EXPR:
13576 return build_const_cast (type, op, complain);
13577 case DYNAMIC_CAST_EXPR:
13578 return build_dynamic_cast (type, op, complain);
13579 case STATIC_CAST_EXPR:
13580 return build_static_cast (type, op, complain);
13582 gcc_unreachable ();
13586 case POSTDECREMENT_EXPR:
13587 case POSTINCREMENT_EXPR:
13588 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
13589 args, complain, in_decl);
13590 return build_x_unary_op (TREE_CODE (t), op1, complain);
13592 case PREDECREMENT_EXPR:
13593 case PREINCREMENT_EXPR:
13597 case TRUTH_NOT_EXPR:
13598 case UNARY_PLUS_EXPR: /* Unary + */
13599 case REALPART_EXPR:
13600 case IMAGPART_EXPR:
13601 return build_x_unary_op (TREE_CODE (t), RECUR (TREE_OPERAND (t, 0)),
13604 case FIX_TRUNC_EXPR:
13605 return cp_build_unary_op (FIX_TRUNC_EXPR, RECUR (TREE_OPERAND (t, 0)),
13609 op1 = TREE_OPERAND (t, 0);
13610 if (TREE_CODE (op1) == LABEL_DECL)
13611 return finish_label_address_expr (DECL_NAME (op1),
13612 EXPR_LOCATION (op1));
13613 if (TREE_CODE (op1) == SCOPE_REF)
13614 op1 = tsubst_qualified_id (op1, args, complain, in_decl,
13615 /*done=*/true, /*address_p=*/true);
13617 op1 = tsubst_non_call_postfix_expression (op1, args, complain,
13619 return build_x_unary_op (ADDR_EXPR, op1, complain);
13624 case TRUNC_DIV_EXPR:
13625 case CEIL_DIV_EXPR:
13626 case FLOOR_DIV_EXPR:
13627 case ROUND_DIV_EXPR:
13628 case EXACT_DIV_EXPR:
13632 case TRUNC_MOD_EXPR:
13633 case FLOOR_MOD_EXPR:
13634 case TRUTH_ANDIF_EXPR:
13635 case TRUTH_ORIF_EXPR:
13636 case TRUTH_AND_EXPR:
13637 case TRUTH_OR_EXPR:
13653 tree r = build_x_binary_op
13655 RECUR (TREE_OPERAND (t, 0)),
13656 (TREE_NO_WARNING (TREE_OPERAND (t, 0))
13658 : TREE_CODE (TREE_OPERAND (t, 0))),
13659 RECUR (TREE_OPERAND (t, 1)),
13660 (TREE_NO_WARNING (TREE_OPERAND (t, 1))
13662 : TREE_CODE (TREE_OPERAND (t, 1))),
13665 if (EXPR_P (r) && TREE_NO_WARNING (t))
13666 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
13671 return tsubst_qualified_id (t, args, complain, in_decl, /*done=*/true,
13672 /*address_p=*/false);
13674 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
13675 args, complain, in_decl);
13676 return build_x_array_ref (op1, RECUR (TREE_OPERAND (t, 1)), complain);
13679 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
13680 return tsubst_copy (t, args, complain, in_decl);
13684 op1 = TREE_OPERAND (t, 0);
13687 /* When there are no ARGS, we are trying to evaluate a
13688 non-dependent expression from the parser. Trying to do
13689 the substitutions may not work. */
13691 op1 = TREE_TYPE (op1);
13695 ++cp_unevaluated_operand;
13696 ++c_inhibit_evaluation_warnings;
13697 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
13698 /*function_p=*/false,
13699 /*integral_constant_expression_p=*/false);
13700 --cp_unevaluated_operand;
13701 --c_inhibit_evaluation_warnings;
13704 return cxx_sizeof_or_alignof_type (op1, TREE_CODE (t),
13705 complain & tf_error);
13707 return cxx_sizeof_or_alignof_expr (op1, TREE_CODE (t),
13708 complain & tf_error);
13710 case AT_ENCODE_EXPR:
13712 op1 = TREE_OPERAND (t, 0);
13713 ++cp_unevaluated_operand;
13714 ++c_inhibit_evaluation_warnings;
13715 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
13716 /*function_p=*/false,
13717 /*integral_constant_expression_p=*/false);
13718 --cp_unevaluated_operand;
13719 --c_inhibit_evaluation_warnings;
13720 return objc_build_encode_expr (op1);
13723 case NOEXCEPT_EXPR:
13724 op1 = TREE_OPERAND (t, 0);
13725 ++cp_unevaluated_operand;
13726 ++c_inhibit_evaluation_warnings;
13727 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
13728 /*function_p=*/false,
13729 /*integral_constant_expression_p=*/false);
13730 --cp_unevaluated_operand;
13731 --c_inhibit_evaluation_warnings;
13732 return finish_noexcept_expr (op1, complain);
13736 tree r = build_x_modify_expr
13737 (RECUR (TREE_OPERAND (t, 0)),
13738 TREE_CODE (TREE_OPERAND (t, 1)),
13739 RECUR (TREE_OPERAND (t, 2)),
13741 /* TREE_NO_WARNING must be set if either the expression was
13742 parenthesized or it uses an operator such as >>= rather
13743 than plain assignment. In the former case, it was already
13744 set and must be copied. In the latter case,
13745 build_x_modify_expr sets it and it must not be reset
13747 if (TREE_NO_WARNING (t))
13748 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
13753 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
13754 args, complain, in_decl);
13755 /* Remember that there was a reference to this entity. */
13758 return build_x_arrow (op1);
13762 tree placement = RECUR (TREE_OPERAND (t, 0));
13763 tree init = RECUR (TREE_OPERAND (t, 3));
13764 VEC(tree,gc) *placement_vec;
13765 VEC(tree,gc) *init_vec;
13768 if (placement == NULL_TREE)
13769 placement_vec = NULL;
13772 placement_vec = make_tree_vector ();
13773 for (; placement != NULL_TREE; placement = TREE_CHAIN (placement))
13774 VEC_safe_push (tree, gc, placement_vec, TREE_VALUE (placement));
13777 /* If there was an initializer in the original tree, but it
13778 instantiated to an empty list, then we should pass a
13779 non-NULL empty vector to tell build_new that it was an
13780 empty initializer() rather than no initializer. This can
13781 only happen when the initializer is a pack expansion whose
13782 parameter packs are of length zero. */
13783 if (init == NULL_TREE && TREE_OPERAND (t, 3) == NULL_TREE)
13787 init_vec = make_tree_vector ();
13788 if (init == void_zero_node)
13789 gcc_assert (init_vec != NULL);
13792 for (; init != NULL_TREE; init = TREE_CHAIN (init))
13793 VEC_safe_push (tree, gc, init_vec, TREE_VALUE (init));
13797 ret = build_new (&placement_vec,
13798 tsubst (TREE_OPERAND (t, 1), args, complain, in_decl),
13799 RECUR (TREE_OPERAND (t, 2)),
13801 NEW_EXPR_USE_GLOBAL (t),
13804 if (placement_vec != NULL)
13805 release_tree_vector (placement_vec);
13806 if (init_vec != NULL)
13807 release_tree_vector (init_vec);
13813 return delete_sanity
13814 (RECUR (TREE_OPERAND (t, 0)),
13815 RECUR (TREE_OPERAND (t, 1)),
13816 DELETE_EXPR_USE_VEC (t),
13817 DELETE_EXPR_USE_GLOBAL (t),
13820 case COMPOUND_EXPR:
13821 return build_x_compound_expr (RECUR (TREE_OPERAND (t, 0)),
13822 RECUR (TREE_OPERAND (t, 1)),
13828 VEC(tree,gc) *call_args;
13829 unsigned int nargs, i;
13834 function = CALL_EXPR_FN (t);
13835 /* When we parsed the expression, we determined whether or
13836 not Koenig lookup should be performed. */
13837 koenig_p = KOENIG_LOOKUP_P (t);
13838 if (TREE_CODE (function) == SCOPE_REF)
13840 qualified_p = true;
13841 function = tsubst_qualified_id (function, args, complain, in_decl,
13843 /*address_p=*/false);
13845 else if (koenig_p && TREE_CODE (function) == IDENTIFIER_NODE)
13847 /* Do nothing; calling tsubst_copy_and_build on an identifier
13848 would incorrectly perform unqualified lookup again.
13850 Note that we can also have an IDENTIFIER_NODE if the earlier
13851 unqualified lookup found a member function; in that case
13852 koenig_p will be false and we do want to do the lookup
13853 again to find the instantiated member function.
13855 FIXME but doing that causes c++/15272, so we need to stop
13856 using IDENTIFIER_NODE in that situation. */
13857 qualified_p = false;
13861 if (TREE_CODE (function) == COMPONENT_REF)
13863 tree op = TREE_OPERAND (function, 1);
13865 qualified_p = (TREE_CODE (op) == SCOPE_REF
13866 || (BASELINK_P (op)
13867 && BASELINK_QUALIFIED_P (op)));
13870 qualified_p = false;
13872 function = tsubst_copy_and_build (function, args, complain,
13875 integral_constant_expression_p);
13877 if (BASELINK_P (function))
13878 qualified_p = true;
13881 nargs = call_expr_nargs (t);
13882 call_args = make_tree_vector ();
13883 for (i = 0; i < nargs; ++i)
13885 tree arg = CALL_EXPR_ARG (t, i);
13887 if (!PACK_EXPANSION_P (arg))
13888 VEC_safe_push (tree, gc, call_args,
13889 RECUR (CALL_EXPR_ARG (t, i)));
13892 /* Expand the pack expansion and push each entry onto
13894 arg = tsubst_pack_expansion (arg, args, complain, in_decl);
13895 if (TREE_CODE (arg) == TREE_VEC)
13897 unsigned int len, j;
13899 len = TREE_VEC_LENGTH (arg);
13900 for (j = 0; j < len; ++j)
13902 tree value = TREE_VEC_ELT (arg, j);
13903 if (value != NULL_TREE)
13904 value = convert_from_reference (value);
13905 VEC_safe_push (tree, gc, call_args, value);
13910 /* A partial substitution. Add one entry. */
13911 VEC_safe_push (tree, gc, call_args, arg);
13916 /* We do not perform argument-dependent lookup if normal
13917 lookup finds a non-function, in accordance with the
13918 expected resolution of DR 218. */
13920 && ((is_overloaded_fn (function)
13921 /* If lookup found a member function, the Koenig lookup is
13922 not appropriate, even if an unqualified-name was used
13923 to denote the function. */
13924 && !DECL_FUNCTION_MEMBER_P (get_first_fn (function)))
13925 || TREE_CODE (function) == IDENTIFIER_NODE)
13926 /* Only do this when substitution turns a dependent call
13927 into a non-dependent call. */
13928 && type_dependent_expression_p_push (t)
13929 && !any_type_dependent_arguments_p (call_args))
13930 function = perform_koenig_lookup (function, call_args, false,
13933 if (TREE_CODE (function) == IDENTIFIER_NODE
13934 && !any_type_dependent_arguments_p (call_args))
13936 if (koenig_p && (complain & tf_warning_or_error))
13938 /* For backwards compatibility and good diagnostics, try
13939 the unqualified lookup again if we aren't in SFINAE
13941 tree unq = (tsubst_copy_and_build
13942 (function, args, complain, in_decl, true,
13943 integral_constant_expression_p));
13944 if (unq == error_mark_node)
13945 return error_mark_node;
13947 if (unq != function)
13950 if (TREE_CODE (fn) == INDIRECT_REF)
13951 fn = TREE_OPERAND (fn, 0);
13952 if (TREE_CODE (fn) == COMPONENT_REF)
13953 fn = TREE_OPERAND (fn, 1);
13954 if (is_overloaded_fn (fn))
13955 fn = get_first_fn (fn);
13956 permerror (EXPR_LOC_OR_HERE (t),
13957 "%qD was not declared in this scope, "
13958 "and no declarations were found by "
13959 "argument-dependent lookup at the point "
13960 "of instantiation", function);
13962 /* Can't say anything more. */;
13963 else if (DECL_CLASS_SCOPE_P (fn))
13965 inform (EXPR_LOC_OR_HERE (t),
13966 "declarations in dependent base %qT are "
13967 "not found by unqualified lookup",
13968 DECL_CLASS_CONTEXT (fn));
13969 if (current_class_ptr)
13970 inform (EXPR_LOC_OR_HERE (t),
13971 "use %<this->%D%> instead", function);
13973 inform (EXPR_LOC_OR_HERE (t),
13974 "use %<%T::%D%> instead",
13975 current_class_name, function);
13978 inform (0, "%q+D declared here, later in the "
13979 "translation unit", fn);
13983 if (TREE_CODE (function) == IDENTIFIER_NODE)
13985 unqualified_name_lookup_error (function);
13986 release_tree_vector (call_args);
13987 return error_mark_node;
13991 /* Remember that there was a reference to this entity. */
13992 if (DECL_P (function))
13993 mark_used (function);
13995 if (TREE_CODE (function) == OFFSET_REF)
13996 ret = build_offset_ref_call_from_tree (function, &call_args);
13997 else if (TREE_CODE (function) == COMPONENT_REF)
13999 tree instance = TREE_OPERAND (function, 0);
14000 tree fn = TREE_OPERAND (function, 1);
14002 if (processing_template_decl
14003 && (type_dependent_expression_p (instance)
14004 || (!BASELINK_P (fn)
14005 && TREE_CODE (fn) != FIELD_DECL)
14006 || type_dependent_expression_p (fn)
14007 || any_type_dependent_arguments_p (call_args)))
14008 ret = build_nt_call_vec (function, call_args);
14009 else if (!BASELINK_P (fn))
14010 ret = finish_call_expr (function, &call_args,
14011 /*disallow_virtual=*/false,
14012 /*koenig_p=*/false,
14015 ret = (build_new_method_call
14017 &call_args, NULL_TREE,
14018 qualified_p ? LOOKUP_NONVIRTUAL : LOOKUP_NORMAL,
14023 ret = finish_call_expr (function, &call_args,
14024 /*disallow_virtual=*/qualified_p,
14028 release_tree_vector (call_args);
14034 return build_x_conditional_expr
14035 (RECUR (TREE_OPERAND (t, 0)),
14036 RECUR (TREE_OPERAND (t, 1)),
14037 RECUR (TREE_OPERAND (t, 2)),
14040 case PSEUDO_DTOR_EXPR:
14041 return finish_pseudo_destructor_expr
14042 (RECUR (TREE_OPERAND (t, 0)),
14043 RECUR (TREE_OPERAND (t, 1)),
14044 tsubst (TREE_OPERAND (t, 2), args, complain, in_decl));
14048 tree purpose, value, chain;
14050 if (t == void_list_node)
14053 if ((TREE_PURPOSE (t) && PACK_EXPANSION_P (TREE_PURPOSE (t)))
14054 || (TREE_VALUE (t) && PACK_EXPANSION_P (TREE_VALUE (t))))
14056 /* We have pack expansions, so expand those and
14057 create a new list out of it. */
14058 tree purposevec = NULL_TREE;
14059 tree valuevec = NULL_TREE;
14063 /* Expand the argument expressions. */
14064 if (TREE_PURPOSE (t))
14065 purposevec = tsubst_pack_expansion (TREE_PURPOSE (t), args,
14066 complain, in_decl);
14067 if (TREE_VALUE (t))
14068 valuevec = tsubst_pack_expansion (TREE_VALUE (t), args,
14069 complain, in_decl);
14071 /* Build the rest of the list. */
14072 chain = TREE_CHAIN (t);
14073 if (chain && chain != void_type_node)
14074 chain = RECUR (chain);
14076 /* Determine the number of arguments. */
14077 if (purposevec && TREE_CODE (purposevec) == TREE_VEC)
14079 len = TREE_VEC_LENGTH (purposevec);
14080 gcc_assert (!valuevec || len == TREE_VEC_LENGTH (valuevec));
14082 else if (TREE_CODE (valuevec) == TREE_VEC)
14083 len = TREE_VEC_LENGTH (valuevec);
14086 /* Since we only performed a partial substitution into
14087 the argument pack, we only return a single list
14089 if (purposevec == TREE_PURPOSE (t)
14090 && valuevec == TREE_VALUE (t)
14091 && chain == TREE_CHAIN (t))
14094 return tree_cons (purposevec, valuevec, chain);
14097 /* Convert the argument vectors into a TREE_LIST */
14101 /* Grab the Ith values. */
14103 purpose = purposevec ? TREE_VEC_ELT (purposevec, i)
14106 = valuevec ? convert_from_reference (TREE_VEC_ELT (valuevec, i))
14109 /* Build the list (backwards). */
14110 chain = tree_cons (purpose, value, chain);
14116 purpose = TREE_PURPOSE (t);
14118 purpose = RECUR (purpose);
14119 value = TREE_VALUE (t);
14121 value = RECUR (value);
14122 chain = TREE_CHAIN (t);
14123 if (chain && chain != void_type_node)
14124 chain = RECUR (chain);
14125 if (purpose == TREE_PURPOSE (t)
14126 && value == TREE_VALUE (t)
14127 && chain == TREE_CHAIN (t))
14129 return tree_cons (purpose, value, chain);
14132 case COMPONENT_REF:
14138 object = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
14139 args, complain, in_decl);
14140 /* Remember that there was a reference to this entity. */
14141 if (DECL_P (object))
14142 mark_used (object);
14143 object_type = TREE_TYPE (object);
14145 member = TREE_OPERAND (t, 1);
14146 if (BASELINK_P (member))
14147 member = tsubst_baselink (member,
14148 non_reference (TREE_TYPE (object)),
14149 args, complain, in_decl);
14151 member = tsubst_copy (member, args, complain, in_decl);
14152 if (member == error_mark_node)
14153 return error_mark_node;
14155 if (type_dependent_expression_p (object))
14156 /* We can't do much here. */;
14157 else if (!CLASS_TYPE_P (object_type))
14159 if (SCALAR_TYPE_P (object_type))
14161 tree s = NULL_TREE;
14162 tree dtor = member;
14164 if (TREE_CODE (dtor) == SCOPE_REF)
14166 s = TREE_OPERAND (dtor, 0);
14167 dtor = TREE_OPERAND (dtor, 1);
14169 if (TREE_CODE (dtor) == BIT_NOT_EXPR)
14171 dtor = TREE_OPERAND (dtor, 0);
14173 return finish_pseudo_destructor_expr (object, s, dtor);
14177 else if (TREE_CODE (member) == SCOPE_REF
14178 && TREE_CODE (TREE_OPERAND (member, 1)) == TEMPLATE_ID_EXPR)
14180 /* Lookup the template functions now that we know what the
14182 tree scope = TREE_OPERAND (member, 0);
14183 tree tmpl = TREE_OPERAND (TREE_OPERAND (member, 1), 0);
14184 tree args = TREE_OPERAND (TREE_OPERAND (member, 1), 1);
14185 member = lookup_qualified_name (scope, tmpl,
14186 /*is_type_p=*/false,
14187 /*complain=*/false);
14188 if (BASELINK_P (member))
14190 BASELINK_FUNCTIONS (member)
14191 = build_nt (TEMPLATE_ID_EXPR, BASELINK_FUNCTIONS (member),
14193 member = (adjust_result_of_qualified_name_lookup
14194 (member, BINFO_TYPE (BASELINK_BINFO (member)),
14199 qualified_name_lookup_error (scope, tmpl, member,
14201 return error_mark_node;
14204 else if (TREE_CODE (member) == SCOPE_REF
14205 && !CLASS_TYPE_P (TREE_OPERAND (member, 0))
14206 && TREE_CODE (TREE_OPERAND (member, 0)) != NAMESPACE_DECL)
14208 if (complain & tf_error)
14210 if (TYPE_P (TREE_OPERAND (member, 0)))
14211 error ("%qT is not a class or namespace",
14212 TREE_OPERAND (member, 0));
14214 error ("%qD is not a class or namespace",
14215 TREE_OPERAND (member, 0));
14217 return error_mark_node;
14219 else if (TREE_CODE (member) == FIELD_DECL)
14220 return finish_non_static_data_member (member, object, NULL_TREE);
14222 return finish_class_member_access_expr (object, member,
14223 /*template_p=*/false,
14229 (RECUR (TREE_OPERAND (t, 0)));
14233 VEC(constructor_elt,gc) *n;
14234 constructor_elt *ce;
14235 unsigned HOST_WIDE_INT idx;
14236 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
14237 bool process_index_p;
14239 bool need_copy_p = false;
14242 if (type == error_mark_node)
14243 return error_mark_node;
14245 /* digest_init will do the wrong thing if we let it. */
14246 if (type && TYPE_PTRMEMFUNC_P (type))
14249 /* We do not want to process the index of aggregate
14250 initializers as they are identifier nodes which will be
14251 looked up by digest_init. */
14252 process_index_p = !(type && MAYBE_CLASS_TYPE_P (type));
14254 n = VEC_copy (constructor_elt, gc, CONSTRUCTOR_ELTS (t));
14255 newlen = VEC_length (constructor_elt, n);
14256 FOR_EACH_VEC_ELT (constructor_elt, n, idx, ce)
14258 if (ce->index && process_index_p)
14259 ce->index = RECUR (ce->index);
14261 if (PACK_EXPANSION_P (ce->value))
14263 /* Substitute into the pack expansion. */
14264 ce->value = tsubst_pack_expansion (ce->value, args, complain,
14267 if (ce->value == error_mark_node
14268 || PACK_EXPANSION_P (ce->value))
14270 else if (TREE_VEC_LENGTH (ce->value) == 1)
14271 /* Just move the argument into place. */
14272 ce->value = TREE_VEC_ELT (ce->value, 0);
14275 /* Update the length of the final CONSTRUCTOR
14276 arguments vector, and note that we will need to
14278 newlen = newlen + TREE_VEC_LENGTH (ce->value) - 1;
14279 need_copy_p = true;
14283 ce->value = RECUR (ce->value);
14288 VEC(constructor_elt,gc) *old_n = n;
14290 n = VEC_alloc (constructor_elt, gc, newlen);
14291 FOR_EACH_VEC_ELT (constructor_elt, old_n, idx, ce)
14293 if (TREE_CODE (ce->value) == TREE_VEC)
14295 int i, len = TREE_VEC_LENGTH (ce->value);
14296 for (i = 0; i < len; ++i)
14297 CONSTRUCTOR_APPEND_ELT (n, 0,
14298 TREE_VEC_ELT (ce->value, i));
14301 CONSTRUCTOR_APPEND_ELT (n, 0, ce->value);
14305 r = build_constructor (init_list_type_node, n);
14306 CONSTRUCTOR_IS_DIRECT_INIT (r) = CONSTRUCTOR_IS_DIRECT_INIT (t);
14308 if (TREE_HAS_CONSTRUCTOR (t))
14309 return finish_compound_literal (type, r, complain);
14311 TREE_TYPE (r) = type;
14317 tree operand_0 = TREE_OPERAND (t, 0);
14318 if (TYPE_P (operand_0))
14320 operand_0 = tsubst (operand_0, args, complain, in_decl);
14321 return get_typeid (operand_0);
14325 operand_0 = RECUR (operand_0);
14326 return build_typeid (operand_0);
14337 tree r = tsubst_copy (t, args, complain, in_decl);
14339 if (TREE_CODE (TREE_TYPE (t)) != REFERENCE_TYPE)
14340 /* If the original type was a reference, we'll be wrapped in
14341 the appropriate INDIRECT_REF. */
14342 r = convert_from_reference (r);
14347 return build_x_va_arg (RECUR (TREE_OPERAND (t, 0)),
14348 tsubst (TREE_TYPE (t), args, complain, in_decl));
14350 case OFFSETOF_EXPR:
14351 return finish_offsetof (RECUR (TREE_OPERAND (t, 0)));
14355 tree type1 = tsubst_copy (TRAIT_EXPR_TYPE1 (t), args,
14356 complain, in_decl);
14358 tree type2 = TRAIT_EXPR_TYPE2 (t);
14360 type2 = tsubst_copy (type2, args, complain, in_decl);
14362 return finish_trait_expr (TRAIT_EXPR_KIND (t), type1, type2);
14367 tree old_stmt_expr = cur_stmt_expr;
14368 tree stmt_expr = begin_stmt_expr ();
14370 cur_stmt_expr = stmt_expr;
14371 tsubst_expr (STMT_EXPR_STMT (t), args, complain, in_decl,
14372 integral_constant_expression_p);
14373 stmt_expr = finish_stmt_expr (stmt_expr, false);
14374 cur_stmt_expr = old_stmt_expr;
14376 /* If the resulting list of expression statement is empty,
14377 fold it further into void_zero_node. */
14378 if (empty_expr_stmt_p (stmt_expr))
14379 stmt_expr = void_zero_node;
14385 t = tsubst_copy (t, args, complain, in_decl);
14386 /* As in finish_id_expression, we resolve enumeration constants
14387 to their underlying values. */
14388 if (TREE_CODE (t) == CONST_DECL && !processing_template_decl)
14390 used_types_insert (TREE_TYPE (t));
14391 return DECL_INITIAL (t);
14397 tree r = build_lambda_expr ();
14399 tree type = tsubst (LAMBDA_EXPR_CLOSURE (t), args, complain, NULL_TREE);
14400 LAMBDA_EXPR_CLOSURE (r) = type;
14401 CLASSTYPE_LAMBDA_EXPR (type) = r;
14403 LAMBDA_EXPR_LOCATION (r)
14404 = LAMBDA_EXPR_LOCATION (t);
14405 LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (r)
14406 = LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (t);
14407 LAMBDA_EXPR_MUTABLE_P (r) = LAMBDA_EXPR_MUTABLE_P (t);
14408 LAMBDA_EXPR_DISCRIMINATOR (r)
14409 = (LAMBDA_EXPR_DISCRIMINATOR (t));
14410 LAMBDA_EXPR_EXTRA_SCOPE (r)
14411 = RECUR (LAMBDA_EXPR_EXTRA_SCOPE (t));
14412 if (LAMBDA_EXPR_RETURN_TYPE (t) == dependent_lambda_return_type_node)
14414 LAMBDA_EXPR_RETURN_TYPE (r) = dependent_lambda_return_type_node;
14415 LAMBDA_EXPR_DEDUCE_RETURN_TYPE_P (r) = true;
14418 LAMBDA_EXPR_RETURN_TYPE (r)
14419 = tsubst (LAMBDA_EXPR_RETURN_TYPE (t), args, complain, in_decl);
14421 gcc_assert (LAMBDA_EXPR_THIS_CAPTURE (t) == NULL_TREE
14422 && LAMBDA_EXPR_PENDING_PROXIES (t) == NULL);
14424 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
14425 determine_visibility (TYPE_NAME (type));
14426 /* Now that we know visibility, instantiate the type so we have a
14427 declaration of the op() for later calls to lambda_function. */
14428 complete_type (type);
14430 /* The capture list refers to closure members, so this needs to
14431 wait until after we finish instantiating the type. */
14432 LAMBDA_EXPR_CAPTURE_LIST (r)
14433 = RECUR (LAMBDA_EXPR_CAPTURE_LIST (t));
14435 return build_lambda_object (r);
14439 /* We can get here for a constant initializer of non-dependent type.
14440 FIXME stop folding in cp_parser_initializer_clause. */
14441 gcc_assert (TREE_CONSTANT (t));
14443 tree r = get_target_expr (RECUR (TARGET_EXPR_INITIAL (t)));
14444 TREE_CONSTANT (r) = true;
14448 case TRANSACTION_EXPR:
14449 return tsubst_expr(t, args, complain, in_decl,
14450 integral_constant_expression_p);
14453 /* Handle Objective-C++ constructs, if appropriate. */
14456 = objcp_tsubst_copy_and_build (t, args, complain,
14457 in_decl, /*function_p=*/false);
14461 return tsubst_copy (t, args, complain, in_decl);
14467 /* Verify that the instantiated ARGS are valid. For type arguments,
14468 make sure that the type's linkage is ok. For non-type arguments,
14469 make sure they are constants if they are integral or enumerations.
14470 Emit an error under control of COMPLAIN, and return TRUE on error. */
14473 check_instantiated_arg (tree tmpl, tree t, tsubst_flags_t complain)
14475 if (ARGUMENT_PACK_P (t))
14477 tree vec = ARGUMENT_PACK_ARGS (t);
14478 int len = TREE_VEC_LENGTH (vec);
14479 bool result = false;
14482 for (i = 0; i < len; ++i)
14483 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (vec, i), complain))
14487 else if (TYPE_P (t))
14489 /* [basic.link]: A name with no linkage (notably, the name
14490 of a class or enumeration declared in a local scope)
14491 shall not be used to declare an entity with linkage.
14492 This implies that names with no linkage cannot be used as
14495 DR 757 relaxes this restriction for C++0x. */
14496 tree nt = (cxx_dialect > cxx98 ? NULL_TREE
14497 : no_linkage_check (t, /*relaxed_p=*/false));
14501 /* DR 488 makes use of a type with no linkage cause
14502 type deduction to fail. */
14503 if (complain & tf_error)
14505 if (TYPE_ANONYMOUS_P (nt))
14506 error ("%qT is/uses anonymous type", t);
14508 error ("template argument for %qD uses local type %qT",
14513 /* In order to avoid all sorts of complications, we do not
14514 allow variably-modified types as template arguments. */
14515 else if (variably_modified_type_p (t, NULL_TREE))
14517 if (complain & tf_error)
14518 error ("%qT is a variably modified type", t);
14522 /* A non-type argument of integral or enumerated type must be a
14524 else if (TREE_TYPE (t)
14525 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t))
14526 && !TREE_CONSTANT (t))
14528 if (complain & tf_error)
14529 error ("integral expression %qE is not constant", t);
14536 check_instantiated_args (tree tmpl, tree args, tsubst_flags_t complain)
14538 int ix, len = DECL_NTPARMS (tmpl);
14539 bool result = false;
14541 for (ix = 0; ix != len; ix++)
14543 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (args, ix), complain))
14546 if (result && (complain & tf_error))
14547 error (" trying to instantiate %qD", tmpl);
14551 /* In C++0x, it's possible to have a function template whose type depends
14552 on itself recursively. This is most obvious with decltype, but can also
14553 occur with enumeration scope (c++/48969). So we need to catch infinite
14554 recursion and reject the substitution at deduction time; this function
14555 will return error_mark_node for any repeated substitution.
14557 This also catches excessive recursion such as when f<N> depends on
14558 f<N-1> across all integers, and returns error_mark_node for all the
14559 substitutions back up to the initial one.
14561 This is, of course, not reentrant. */
14564 deduction_tsubst_fntype (tree fn, tree targs, tsubst_flags_t complain)
14566 static bool excessive_deduction_depth;
14567 static int deduction_depth;
14568 struct pending_template *old_last_pend = last_pending_template;
14569 struct tinst_level *old_error_tinst = last_error_tinst_level;
14571 tree fntype = TREE_TYPE (fn);
14575 if (excessive_deduction_depth)
14576 return error_mark_node;
14578 tinst = build_tree_list (fn, targs);
14579 if (!push_tinst_level (tinst))
14581 excessive_deduction_depth = true;
14583 return error_mark_node;
14586 input_location = DECL_SOURCE_LOCATION (fn);
14588 push_deduction_access_scope (fn);
14589 r = tsubst (fntype, targs, complain, NULL_TREE);
14590 pop_deduction_access_scope (fn);
14593 if (excessive_deduction_depth)
14595 r = error_mark_node;
14596 if (deduction_depth == 0)
14597 /* Reset once we're all the way out. */
14598 excessive_deduction_depth = false;
14601 pop_tinst_level ();
14602 /* We can't free this if a pending_template entry or last_error_tinst_level
14603 is pointing at it. */
14604 if (last_pending_template == old_last_pend
14605 && last_error_tinst_level == old_error_tinst)
14610 /* Instantiate the indicated variable or function template TMPL with
14611 the template arguments in TARG_PTR. */
14614 instantiate_template_1 (tree tmpl, tree orig_args, tsubst_flags_t complain)
14616 tree targ_ptr = orig_args;
14621 if (tmpl == error_mark_node)
14622 return error_mark_node;
14624 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
14626 /* If this function is a clone, handle it specially. */
14627 if (DECL_CLONED_FUNCTION_P (tmpl))
14632 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
14633 DECL_CLONED_FUNCTION. */
14634 spec = instantiate_template (DECL_ABSTRACT_ORIGIN (tmpl),
14635 targ_ptr, complain);
14636 if (spec == error_mark_node)
14637 return error_mark_node;
14639 /* Look for the clone. */
14640 FOR_EACH_CLONE (clone, spec)
14641 if (DECL_NAME (clone) == DECL_NAME (tmpl))
14643 /* We should always have found the clone by now. */
14644 gcc_unreachable ();
14648 /* Check to see if we already have this specialization. */
14649 gen_tmpl = most_general_template (tmpl);
14650 if (tmpl != gen_tmpl)
14651 /* The TMPL is a partial instantiation. To get a full set of
14652 arguments we must add the arguments used to perform the
14653 partial instantiation. */
14654 targ_ptr = add_outermost_template_args (DECL_TI_ARGS (tmpl),
14657 /* It would be nice to avoid hashing here and then again in tsubst_decl,
14658 but it doesn't seem to be on the hot path. */
14659 spec = retrieve_specialization (gen_tmpl, targ_ptr, 0);
14661 gcc_assert (tmpl == gen_tmpl
14662 || ((fndecl = retrieve_specialization (tmpl, orig_args, 0))
14664 || fndecl == NULL_TREE);
14666 if (spec != NULL_TREE)
14669 if (check_instantiated_args (gen_tmpl, INNERMOST_TEMPLATE_ARGS (targ_ptr),
14671 return error_mark_node;
14673 /* We are building a FUNCTION_DECL, during which the access of its
14674 parameters and return types have to be checked. However this
14675 FUNCTION_DECL which is the desired context for access checking
14676 is not built yet. We solve this chicken-and-egg problem by
14677 deferring all checks until we have the FUNCTION_DECL. */
14678 push_deferring_access_checks (dk_deferred);
14680 /* Instantiation of the function happens in the context of the function
14681 template, not the context of the overload resolution we're doing. */
14682 push_to_top_level ();
14683 if (DECL_CLASS_SCOPE_P (gen_tmpl))
14685 tree ctx = tsubst (DECL_CONTEXT (gen_tmpl), targ_ptr,
14686 complain, gen_tmpl);
14687 push_nested_class (ctx);
14689 /* Substitute template parameters to obtain the specialization. */
14690 fndecl = tsubst (DECL_TEMPLATE_RESULT (gen_tmpl),
14691 targ_ptr, complain, gen_tmpl);
14692 if (DECL_CLASS_SCOPE_P (gen_tmpl))
14693 pop_nested_class ();
14694 pop_from_top_level ();
14696 if (fndecl == error_mark_node)
14697 return error_mark_node;
14699 /* Now we know the specialization, compute access previously
14701 push_access_scope (fndecl);
14703 /* Some typedefs referenced from within the template code need to be access
14704 checked at template instantiation time, i.e now. These types were
14705 added to the template at parsing time. Let's get those and perfom
14706 the acces checks then. */
14707 perform_typedefs_access_check (DECL_TEMPLATE_RESULT (tmpl), targ_ptr);
14708 perform_deferred_access_checks ();
14709 pop_access_scope (fndecl);
14710 pop_deferring_access_checks ();
14712 /* The DECL_TI_TEMPLATE should always be the immediate parent
14713 template, not the most general template. */
14714 DECL_TI_TEMPLATE (fndecl) = tmpl;
14716 /* If we've just instantiated the main entry point for a function,
14717 instantiate all the alternate entry points as well. We do this
14718 by cloning the instantiation of the main entry point, not by
14719 instantiating the template clones. */
14720 if (DECL_CHAIN (gen_tmpl) && DECL_CLONED_FUNCTION_P (DECL_CHAIN (gen_tmpl)))
14721 clone_function_decl (fndecl, /*update_method_vec_p=*/0);
14726 /* Wrapper for instantiate_template_1. */
14729 instantiate_template (tree tmpl, tree orig_args, tsubst_flags_t complain)
14732 timevar_push (TV_TEMPLATE_INST);
14733 ret = instantiate_template_1 (tmpl, orig_args, complain);
14734 timevar_pop (TV_TEMPLATE_INST);
14738 /* We're going to do deduction substitution on the type of TMPL, a function
14739 template. In C++11 mode, push into that access scope. In C++03 mode,
14740 disable access checking. */
14743 push_deduction_access_scope (tree tmpl)
14745 if (cxx_dialect >= cxx0x)
14747 int ptd = processing_template_decl;
14748 push_access_scope (DECL_TEMPLATE_RESULT (tmpl));
14749 /* Preserve processing_template_decl across push_to_top_level. */
14750 if (ptd && !processing_template_decl)
14751 ++processing_template_decl;
14754 push_deferring_access_checks (dk_no_check);
14757 /* And pop back out. */
14760 pop_deduction_access_scope (tree tmpl)
14762 if (cxx_dialect >= cxx0x)
14763 pop_access_scope (DECL_TEMPLATE_RESULT (tmpl));
14765 pop_deferring_access_checks ();
14768 /* PARM is a template parameter pack for FN. Returns true iff
14769 PARM is used in a deducible way in the argument list of FN. */
14772 pack_deducible_p (tree parm, tree fn)
14774 tree t = FUNCTION_FIRST_USER_PARMTYPE (fn);
14775 for (; t; t = TREE_CHAIN (t))
14777 tree type = TREE_VALUE (t);
14779 if (!PACK_EXPANSION_P (type))
14781 for (packs = PACK_EXPANSION_PARAMETER_PACKS (type);
14782 packs; packs = TREE_CHAIN (packs))
14783 if (TREE_VALUE (packs) == parm)
14785 /* The template parameter pack is used in a function parameter
14786 pack. If this is the end of the parameter list, the
14787 template parameter pack is deducible. */
14788 if (TREE_CHAIN (t) == void_list_node)
14791 /* Otherwise, not. Well, it could be deduced from
14792 a non-pack parameter, but doing so would end up with
14793 a deduction mismatch, so don't bother. */
14797 /* The template parameter pack isn't used in any function parameter
14798 packs, but it might be used deeper, e.g. tuple<Args...>. */
14802 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
14803 NARGS elements of the arguments that are being used when calling
14804 it. TARGS is a vector into which the deduced template arguments
14807 Return zero for success, 2 for an incomplete match that doesn't resolve
14808 all the types, and 1 for complete failure. An error message will be
14809 printed only for an incomplete match.
14811 If FN is a conversion operator, or we are trying to produce a specific
14812 specialization, RETURN_TYPE is the return type desired.
14814 The EXPLICIT_TARGS are explicit template arguments provided via a
14817 The parameter STRICT is one of:
14820 We are deducing arguments for a function call, as in
14821 [temp.deduct.call].
14824 We are deducing arguments for a conversion function, as in
14825 [temp.deduct.conv].
14828 We are deducing arguments when doing an explicit instantiation
14829 as in [temp.explicit], when determining an explicit specialization
14830 as in [temp.expl.spec], or when taking the address of a function
14831 template, as in [temp.deduct.funcaddr]. */
14834 fn_type_unification (tree fn,
14835 tree explicit_targs,
14838 unsigned int nargs,
14840 unification_kind_t strict,
14848 gcc_assert (TREE_CODE (fn) == TEMPLATE_DECL);
14850 fntype = TREE_TYPE (fn);
14851 if (explicit_targs)
14855 The specified template arguments must match the template
14856 parameters in kind (i.e., type, nontype, template), and there
14857 must not be more arguments than there are parameters;
14858 otherwise type deduction fails.
14860 Nontype arguments must match the types of the corresponding
14861 nontype template parameters, or must be convertible to the
14862 types of the corresponding nontype parameters as specified in
14863 _temp.arg.nontype_, otherwise type deduction fails.
14865 All references in the function type of the function template
14866 to the corresponding template parameters are replaced by the
14867 specified template argument values. If a substitution in a
14868 template parameter or in the function type of the function
14869 template results in an invalid type, type deduction fails. */
14870 tree tparms = DECL_INNERMOST_TEMPLATE_PARMS (fn);
14871 int i, len = TREE_VEC_LENGTH (tparms);
14872 tree converted_args;
14873 bool incomplete = false;
14875 if (explicit_targs == error_mark_node)
14876 return unify_invalid (explain_p);
14879 = (coerce_template_parms (tparms, explicit_targs, NULL_TREE,
14881 ? tf_warning_or_error
14883 /*require_all_args=*/false,
14884 /*use_default_args=*/false));
14885 if (converted_args == error_mark_node)
14888 /* Substitute the explicit args into the function type. This is
14889 necessary so that, for instance, explicitly declared function
14890 arguments can match null pointed constants. If we were given
14891 an incomplete set of explicit args, we must not do semantic
14892 processing during substitution as we could create partial
14894 for (i = 0; i < len; i++)
14896 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
14897 bool parameter_pack = false;
14898 tree targ = TREE_VEC_ELT (converted_args, i);
14900 /* Dig out the actual parm. */
14901 if (TREE_CODE (parm) == TYPE_DECL
14902 || TREE_CODE (parm) == TEMPLATE_DECL)
14904 parm = TREE_TYPE (parm);
14905 parameter_pack = TEMPLATE_TYPE_PARAMETER_PACK (parm);
14907 else if (TREE_CODE (parm) == PARM_DECL)
14909 parm = DECL_INITIAL (parm);
14910 parameter_pack = TEMPLATE_PARM_PARAMETER_PACK (parm);
14913 if (!parameter_pack && targ == NULL_TREE)
14914 /* No explicit argument for this template parameter. */
14917 if (parameter_pack && pack_deducible_p (parm, fn))
14919 /* Mark the argument pack as "incomplete". We could
14920 still deduce more arguments during unification.
14921 We remove this mark in type_unification_real. */
14924 ARGUMENT_PACK_INCOMPLETE_P(targ) = 1;
14925 ARGUMENT_PACK_EXPLICIT_ARGS (targ)
14926 = ARGUMENT_PACK_ARGS (targ);
14929 /* We have some incomplete argument packs. */
14934 processing_template_decl += incomplete;
14935 fntype = deduction_tsubst_fntype (fn, converted_args,
14937 ? tf_warning_or_error
14939 processing_template_decl -= incomplete;
14941 if (fntype == error_mark_node)
14944 /* Place the explicitly specified arguments in TARGS. */
14945 for (i = NUM_TMPL_ARGS (converted_args); i--;)
14946 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (converted_args, i);
14949 /* Never do unification on the 'this' parameter. */
14950 parms = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (fntype));
14956 parms = tree_cons (NULL_TREE, TREE_TYPE (fntype), parms);
14957 new_args = XALLOCAVEC (tree, nargs + 1);
14958 new_args[0] = return_type;
14959 memcpy (new_args + 1, args, nargs * sizeof (tree));
14964 /* We allow incomplete unification without an error message here
14965 because the standard doesn't seem to explicitly prohibit it. Our
14966 callers must be ready to deal with unification failures in any
14968 result = type_unification_real (DECL_INNERMOST_TEMPLATE_PARMS (fn),
14969 targs, parms, args, nargs, /*subr=*/0,
14970 strict, flags, explain_p);
14972 /* Now that we have bindings for all of the template arguments,
14973 ensure that the arguments deduced for the template template
14974 parameters have compatible template parameter lists. We cannot
14975 check this property before we have deduced all template
14976 arguments, because the template parameter types of a template
14977 template parameter might depend on prior template parameters
14978 deduced after the template template parameter. The following
14979 ill-formed example illustrates this issue:
14981 template<typename T, template<T> class C> void f(C<5>, T);
14983 template<int N> struct X {};
14986 f(X<5>(), 5l); // error: template argument deduction fails
14989 The template parameter list of 'C' depends on the template type
14990 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
14991 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
14992 time that we deduce 'C'. */
14994 && !template_template_parm_bindings_ok_p
14995 (DECL_INNERMOST_TEMPLATE_PARMS (fn), targs))
14996 return unify_inconsistent_template_template_parameters (explain_p);
14999 /* All is well so far. Now, check:
15003 When all template arguments have been deduced, all uses of
15004 template parameters in nondeduced contexts are replaced with
15005 the corresponding deduced argument values. If the
15006 substitution results in an invalid type, as described above,
15007 type deduction fails. */
15009 tree substed = deduction_tsubst_fntype (fn, targs,
15011 ? tf_warning_or_error
15013 if (substed == error_mark_node)
15016 /* If we're looking for an exact match, check that what we got
15017 is indeed an exact match. It might not be if some template
15018 parameters are used in non-deduced contexts. */
15019 if (strict == DEDUCE_EXACT)
15024 = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (substed));
15026 sarg = tree_cons (NULL_TREE, TREE_TYPE (substed), sarg);
15027 for (i = 0; i < nargs && sarg; ++i, sarg = TREE_CHAIN (sarg))
15028 if (!same_type_p (args[i], TREE_VALUE (sarg)))
15029 return unify_type_mismatch (explain_p, args[i],
15030 TREE_VALUE (sarg));
15037 /* Adjust types before performing type deduction, as described in
15038 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
15039 sections are symmetric. PARM is the type of a function parameter
15040 or the return type of the conversion function. ARG is the type of
15041 the argument passed to the call, or the type of the value
15042 initialized with the result of the conversion function.
15043 ARG_EXPR is the original argument expression, which may be null. */
15046 maybe_adjust_types_for_deduction (unification_kind_t strict,
15060 /* Swap PARM and ARG throughout the remainder of this
15061 function; the handling is precisely symmetric since PARM
15062 will initialize ARG rather than vice versa. */
15070 /* Core issue #873: Do the DR606 thing (see below) for these cases,
15071 too, but here handle it by stripping the reference from PARM
15072 rather than by adding it to ARG. */
15073 if (TREE_CODE (*parm) == REFERENCE_TYPE
15074 && TYPE_REF_IS_RVALUE (*parm)
15075 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
15076 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
15077 && TREE_CODE (*arg) == REFERENCE_TYPE
15078 && !TYPE_REF_IS_RVALUE (*arg))
15079 *parm = TREE_TYPE (*parm);
15080 /* Nothing else to do in this case. */
15084 gcc_unreachable ();
15087 if (TREE_CODE (*parm) != REFERENCE_TYPE)
15089 /* [temp.deduct.call]
15091 If P is not a reference type:
15093 --If A is an array type, the pointer type produced by the
15094 array-to-pointer standard conversion (_conv.array_) is
15095 used in place of A for type deduction; otherwise,
15097 --If A is a function type, the pointer type produced by
15098 the function-to-pointer standard conversion
15099 (_conv.func_) is used in place of A for type deduction;
15102 --If A is a cv-qualified type, the top level
15103 cv-qualifiers of A's type are ignored for type
15105 if (TREE_CODE (*arg) == ARRAY_TYPE)
15106 *arg = build_pointer_type (TREE_TYPE (*arg));
15107 else if (TREE_CODE (*arg) == FUNCTION_TYPE)
15108 *arg = build_pointer_type (*arg);
15110 *arg = TYPE_MAIN_VARIANT (*arg);
15113 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
15114 of the form T&&, where T is a template parameter, and the argument
15115 is an lvalue, T is deduced as A& */
15116 if (TREE_CODE (*parm) == REFERENCE_TYPE
15117 && TYPE_REF_IS_RVALUE (*parm)
15118 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
15119 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
15120 && (arg_expr ? real_lvalue_p (arg_expr)
15121 /* try_one_overload doesn't provide an arg_expr, but
15122 functions are always lvalues. */
15123 : TREE_CODE (*arg) == FUNCTION_TYPE))
15124 *arg = build_reference_type (*arg);
15126 /* [temp.deduct.call]
15128 If P is a cv-qualified type, the top level cv-qualifiers
15129 of P's type are ignored for type deduction. If P is a
15130 reference type, the type referred to by P is used for
15132 *parm = TYPE_MAIN_VARIANT (*parm);
15133 if (TREE_CODE (*parm) == REFERENCE_TYPE)
15135 *parm = TREE_TYPE (*parm);
15136 result |= UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
15139 /* DR 322. For conversion deduction, remove a reference type on parm
15140 too (which has been swapped into ARG). */
15141 if (strict == DEDUCE_CONV && TREE_CODE (*arg) == REFERENCE_TYPE)
15142 *arg = TREE_TYPE (*arg);
15147 /* Subroutine of unify_one_argument. PARM is a function parameter of a
15148 template which does contain any deducible template parameters; check if
15149 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
15150 unify_one_argument. */
15153 check_non_deducible_conversion (tree parm, tree arg, int strict,
15154 int flags, bool explain_p)
15159 type = TREE_TYPE (arg);
15163 if (same_type_p (parm, type))
15164 return unify_success (explain_p);
15166 if (strict == DEDUCE_CONV)
15168 if (can_convert_arg (type, parm, NULL_TREE, flags))
15169 return unify_success (explain_p);
15171 else if (strict != DEDUCE_EXACT)
15173 if (can_convert_arg (parm, type,
15174 TYPE_P (arg) ? NULL_TREE : arg,
15176 return unify_success (explain_p);
15179 if (strict == DEDUCE_EXACT)
15180 return unify_type_mismatch (explain_p, parm, arg);
15182 return unify_arg_conversion (explain_p, parm, type, arg);
15185 /* Subroutine of type_unification_real and unify_pack_expansion to
15186 handle unification of a single P/A pair. Parameters are as
15187 for those functions. */
15190 unify_one_argument (tree tparms, tree targs, tree parm, tree arg,
15191 int subr, unification_kind_t strict, int flags,
15194 tree arg_expr = NULL_TREE;
15197 if (arg == error_mark_node || parm == error_mark_node)
15198 return unify_invalid (explain_p);
15199 if (arg == unknown_type_node)
15200 /* We can't deduce anything from this, but we might get all the
15201 template args from other function args. */
15202 return unify_success (explain_p);
15204 /* FIXME uses_deducible_template_parms */
15205 if (TYPE_P (parm) && !uses_template_parms (parm))
15206 return check_non_deducible_conversion (parm, arg, strict, flags,
15212 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
15213 | UNIFY_ALLOW_MORE_CV_QUAL
15214 | UNIFY_ALLOW_DERIVED);
15218 arg_strict = UNIFY_ALLOW_LESS_CV_QUAL;
15222 arg_strict = UNIFY_ALLOW_NONE;
15226 gcc_unreachable ();
15229 /* We only do these transformations if this is the top-level
15230 parameter_type_list in a call or declaration matching; in other
15231 situations (nested function declarators, template argument lists) we
15232 won't be comparing a type to an expression, and we don't do any type
15238 gcc_assert (TREE_TYPE (arg) != NULL_TREE);
15239 if (type_unknown_p (arg))
15241 /* [temp.deduct.type] A template-argument can be
15242 deduced from a pointer to function or pointer
15243 to member function argument if the set of
15244 overloaded functions does not contain function
15245 templates and at most one of a set of
15246 overloaded functions provides a unique
15249 if (resolve_overloaded_unification
15250 (tparms, targs, parm, arg, strict,
15251 arg_strict, explain_p))
15252 return unify_success (explain_p);
15253 return unify_overload_resolution_failure (explain_p, arg);
15257 arg = unlowered_expr_type (arg);
15258 if (arg == error_mark_node)
15259 return unify_invalid (explain_p);
15263 maybe_adjust_types_for_deduction (strict, &parm, &arg, arg_expr);
15266 gcc_assert ((TYPE_P (parm) || TREE_CODE (parm) == TEMPLATE_DECL)
15267 == (TYPE_P (arg) || TREE_CODE (arg) == TEMPLATE_DECL));
15269 /* For deduction from an init-list we need the actual list. */
15270 if (arg_expr && BRACE_ENCLOSED_INITIALIZER_P (arg_expr))
15272 return unify (tparms, targs, parm, arg, arg_strict, explain_p);
15275 /* Most parms like fn_type_unification.
15277 If SUBR is 1, we're being called recursively (to unify the
15278 arguments of a function or method parameter of a function
15282 type_unification_real (tree tparms,
15286 unsigned int xnargs,
15288 unification_kind_t strict,
15294 int ntparms = TREE_VEC_LENGTH (tparms);
15295 int saw_undeduced = 0;
15298 unsigned int nargs;
15301 gcc_assert (TREE_CODE (tparms) == TREE_VEC);
15302 gcc_assert (xparms == NULL_TREE || TREE_CODE (xparms) == TREE_LIST);
15303 gcc_assert (ntparms > 0);
15305 /* Reset the number of non-defaulted template arguments contained
15307 NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs) = NULL_TREE;
15315 while (parms && parms != void_list_node
15318 parm = TREE_VALUE (parms);
15320 if (TREE_CODE (parm) == TYPE_PACK_EXPANSION
15321 && (!TREE_CHAIN (parms) || TREE_CHAIN (parms) == void_list_node))
15322 /* For a function parameter pack that occurs at the end of the
15323 parameter-declaration-list, the type A of each remaining
15324 argument of the call is compared with the type P of the
15325 declarator-id of the function parameter pack. */
15328 parms = TREE_CHAIN (parms);
15330 if (TREE_CODE (parm) == TYPE_PACK_EXPANSION)
15331 /* For a function parameter pack that does not occur at the
15332 end of the parameter-declaration-list, the type of the
15333 parameter pack is a non-deduced context. */
15339 if (unify_one_argument (tparms, targs, parm, arg, subr, strict,
15345 && parms != void_list_node
15346 && TREE_CODE (TREE_VALUE (parms)) == TYPE_PACK_EXPANSION)
15348 /* Unify the remaining arguments with the pack expansion type. */
15350 tree parmvec = make_tree_vec (1);
15352 /* Allocate a TREE_VEC and copy in all of the arguments */
15353 argvec = make_tree_vec (nargs - ia);
15354 for (i = 0; ia < nargs; ++ia, ++i)
15355 TREE_VEC_ELT (argvec, i) = args[ia];
15357 /* Copy the parameter into parmvec. */
15358 TREE_VEC_ELT (parmvec, 0) = TREE_VALUE (parms);
15359 if (unify_pack_expansion (tparms, targs, parmvec, argvec, strict,
15360 /*subr=*/subr, explain_p))
15363 /* Advance to the end of the list of parameters. */
15364 parms = TREE_CHAIN (parms);
15367 /* Fail if we've reached the end of the parm list, and more args
15368 are present, and the parm list isn't variadic. */
15369 if (ia < nargs && parms == void_list_node)
15370 return unify_too_many_arguments (explain_p, nargs, ia);
15371 /* Fail if parms are left and they don't have default values. */
15372 if (parms && parms != void_list_node
15373 && TREE_PURPOSE (parms) == NULL_TREE)
15375 unsigned int count = nargs;
15377 while (p && p != void_list_node)
15380 p = TREE_CHAIN (p);
15382 return unify_too_few_arguments (explain_p, ia, count);
15387 tsubst_flags_t complain = (explain_p
15388 ? tf_warning_or_error
15391 /* Check to see if we need another pass before we start clearing
15392 ARGUMENT_PACK_INCOMPLETE_P. */
15393 for (i = 0; i < ntparms; i++)
15395 tree targ = TREE_VEC_ELT (targs, i);
15396 tree tparm = TREE_VEC_ELT (tparms, i);
15398 if (targ || tparm == error_mark_node)
15400 tparm = TREE_VALUE (tparm);
15402 /* If this is an undeduced nontype parameter that depends on
15403 a type parameter, try another pass; its type may have been
15404 deduced from a later argument than the one from which
15405 this parameter can be deduced. */
15406 if (TREE_CODE (tparm) == PARM_DECL
15407 && uses_template_parms (TREE_TYPE (tparm))
15408 && !saw_undeduced++)
15412 for (i = 0; i < ntparms; i++)
15414 tree targ = TREE_VEC_ELT (targs, i);
15415 tree tparm = TREE_VEC_ELT (tparms, i);
15417 /* Clear the "incomplete" flags on all argument packs now so that
15418 substituting them into later default arguments works. */
15419 if (targ && ARGUMENT_PACK_P (targ))
15421 ARGUMENT_PACK_INCOMPLETE_P (targ) = 0;
15422 ARGUMENT_PACK_EXPLICIT_ARGS (targ) = NULL_TREE;
15425 if (targ || tparm == error_mark_node)
15427 tparm = TREE_VALUE (tparm);
15429 /* Core issue #226 (C++0x) [temp.deduct]:
15431 If a template argument has not been deduced, its
15432 default template argument, if any, is used.
15434 When we are in C++98 mode, TREE_PURPOSE will either
15435 be NULL_TREE or ERROR_MARK_NODE, so we do not need
15436 to explicitly check cxx_dialect here. */
15437 if (TREE_PURPOSE (TREE_VEC_ELT (tparms, i)))
15439 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
15440 tree arg = TREE_PURPOSE (TREE_VEC_ELT (tparms, i));
15441 location_t save_loc = input_location;
15443 input_location = DECL_SOURCE_LOCATION (parm);
15444 arg = tsubst_template_arg (arg, targs, complain, NULL_TREE);
15445 arg = convert_template_argument (parm, arg, targs, complain,
15447 input_location = save_loc;
15448 if (arg == error_mark_node)
15452 TREE_VEC_ELT (targs, i) = arg;
15453 /* The position of the first default template argument,
15454 is also the number of non-defaulted arguments in TARGS.
15456 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs))
15457 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, i);
15462 /* If the type parameter is a parameter pack, then it will
15463 be deduced to an empty parameter pack. */
15464 if (template_parameter_pack_p (tparm))
15468 if (TREE_CODE (tparm) == TEMPLATE_PARM_INDEX)
15470 arg = make_node (NONTYPE_ARGUMENT_PACK);
15471 TREE_TYPE (arg) = TREE_TYPE (TEMPLATE_PARM_DECL (tparm));
15472 TREE_CONSTANT (arg) = 1;
15475 arg = cxx_make_type (TYPE_ARGUMENT_PACK);
15477 SET_ARGUMENT_PACK_ARGS (arg, make_tree_vec (0));
15479 TREE_VEC_ELT (targs, i) = arg;
15483 return unify_parameter_deduction_failure (explain_p, tparm);
15486 #ifdef ENABLE_CHECKING
15487 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs))
15488 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, TREE_VEC_LENGTH (targs));
15491 return unify_success (explain_p);
15494 /* Subroutine of type_unification_real. Args are like the variables
15495 at the call site. ARG is an overloaded function (or template-id);
15496 we try deducing template args from each of the overloads, and if
15497 only one succeeds, we go with that. Modifies TARGS and returns
15498 true on success. */
15501 resolve_overloaded_unification (tree tparms,
15505 unification_kind_t strict,
15509 tree tempargs = copy_node (targs);
15511 tree goodfn = NULL_TREE;
15514 if (TREE_CODE (arg) == ADDR_EXPR)
15516 arg = TREE_OPERAND (arg, 0);
15522 if (TREE_CODE (arg) == COMPONENT_REF)
15523 /* Handle `&x' where `x' is some static or non-static member
15525 arg = TREE_OPERAND (arg, 1);
15527 if (TREE_CODE (arg) == OFFSET_REF)
15528 arg = TREE_OPERAND (arg, 1);
15530 /* Strip baselink information. */
15531 if (BASELINK_P (arg))
15532 arg = BASELINK_FUNCTIONS (arg);
15534 if (TREE_CODE (arg) == TEMPLATE_ID_EXPR)
15536 /* If we got some explicit template args, we need to plug them into
15537 the affected templates before we try to unify, in case the
15538 explicit args will completely resolve the templates in question. */
15541 tree expl_subargs = TREE_OPERAND (arg, 1);
15542 arg = TREE_OPERAND (arg, 0);
15544 for (; arg; arg = OVL_NEXT (arg))
15546 tree fn = OVL_CURRENT (arg);
15547 tree subargs, elem;
15549 if (TREE_CODE (fn) != TEMPLATE_DECL)
15552 ++processing_template_decl;
15553 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
15554 expl_subargs, /*check_ret=*/false);
15555 if (subargs && !any_dependent_template_arguments_p (subargs))
15557 elem = tsubst (TREE_TYPE (fn), subargs, tf_none, NULL_TREE);
15558 if (try_one_overload (tparms, targs, tempargs, parm,
15559 elem, strict, sub_strict, addr_p, explain_p)
15560 && (!goodfn || !same_type_p (goodfn, elem)))
15568 --processing_template_decl;
15570 /* If no templates (or more than one) are fully resolved by the
15571 explicit arguments, this template-id is a non-deduced context; it
15572 could still be OK if we deduce all template arguments for the
15573 enclosing call through other arguments. */
15577 else if (TREE_CODE (arg) != OVERLOAD
15578 && TREE_CODE (arg) != FUNCTION_DECL)
15579 /* If ARG is, for example, "(0, &f)" then its type will be unknown
15580 -- but the deduction does not succeed because the expression is
15581 not just the function on its own. */
15584 for (; arg; arg = OVL_NEXT (arg))
15585 if (try_one_overload (tparms, targs, tempargs, parm,
15586 TREE_TYPE (OVL_CURRENT (arg)),
15587 strict, sub_strict, addr_p, explain_p)
15588 && (!goodfn || !decls_match (goodfn, OVL_CURRENT (arg))))
15590 goodfn = OVL_CURRENT (arg);
15594 /* [temp.deduct.type] A template-argument can be deduced from a pointer
15595 to function or pointer to member function argument if the set of
15596 overloaded functions does not contain function templates and at most
15597 one of a set of overloaded functions provides a unique match.
15599 So if we found multiple possibilities, we return success but don't
15600 deduce anything. */
15604 int i = TREE_VEC_LENGTH (targs);
15606 if (TREE_VEC_ELT (tempargs, i))
15607 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (tempargs, i);
15615 /* Core DR 115: In contexts where deduction is done and fails, or in
15616 contexts where deduction is not done, if a template argument list is
15617 specified and it, along with any default template arguments, identifies
15618 a single function template specialization, then the template-id is an
15619 lvalue for the function template specialization. */
15622 resolve_nondeduced_context (tree orig_expr)
15624 tree expr, offset, baselink;
15627 if (!type_unknown_p (orig_expr))
15632 offset = NULL_TREE;
15633 baselink = NULL_TREE;
15635 if (TREE_CODE (expr) == ADDR_EXPR)
15637 expr = TREE_OPERAND (expr, 0);
15640 if (TREE_CODE (expr) == OFFSET_REF)
15643 expr = TREE_OPERAND (expr, 1);
15645 if (BASELINK_P (expr))
15648 expr = BASELINK_FUNCTIONS (expr);
15651 if (TREE_CODE (expr) == TEMPLATE_ID_EXPR)
15654 tree goodfn = NULL_TREE;
15656 /* If we got some explicit template args, we need to plug them into
15657 the affected templates before we try to unify, in case the
15658 explicit args will completely resolve the templates in question. */
15660 tree expl_subargs = TREE_OPERAND (expr, 1);
15661 tree arg = TREE_OPERAND (expr, 0);
15662 tree badfn = NULL_TREE;
15663 tree badargs = NULL_TREE;
15665 for (; arg; arg = OVL_NEXT (arg))
15667 tree fn = OVL_CURRENT (arg);
15668 tree subargs, elem;
15670 if (TREE_CODE (fn) != TEMPLATE_DECL)
15673 ++processing_template_decl;
15674 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
15675 expl_subargs, /*check_ret=*/false);
15676 if (subargs && !any_dependent_template_arguments_p (subargs))
15678 elem = instantiate_template (fn, subargs, tf_none);
15679 if (elem == error_mark_node)
15684 else if (elem && (!goodfn || !decls_match (goodfn, elem)))
15690 --processing_template_decl;
15694 mark_used (goodfn);
15697 expr = build_baselink (BASELINK_BINFO (baselink),
15698 BASELINK_ACCESS_BINFO (baselink),
15699 expr, BASELINK_OPTYPE (baselink));
15703 = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (offset, 0)));
15704 expr = build_offset_ref (base, expr, addr);
15707 expr = cp_build_addr_expr (expr, tf_warning_or_error);
15710 else if (good == 0 && badargs)
15711 /* There were no good options and at least one bad one, so let the
15712 user know what the problem is. */
15713 instantiate_template (badfn, badargs, tf_warning_or_error);
15718 /* Subroutine of resolve_overloaded_unification; does deduction for a single
15719 overload. Fills TARGS with any deduced arguments, or error_mark_node if
15720 different overloads deduce different arguments for a given parm.
15721 ADDR_P is true if the expression for which deduction is being
15722 performed was of the form "& fn" rather than simply "fn".
15724 Returns 1 on success. */
15727 try_one_overload (tree tparms,
15732 unification_kind_t strict,
15741 /* [temp.deduct.type] A template-argument can be deduced from a pointer
15742 to function or pointer to member function argument if the set of
15743 overloaded functions does not contain function templates and at most
15744 one of a set of overloaded functions provides a unique match.
15746 So if this is a template, just return success. */
15748 if (uses_template_parms (arg))
15751 if (TREE_CODE (arg) == METHOD_TYPE)
15752 arg = build_ptrmemfunc_type (build_pointer_type (arg));
15754 arg = build_pointer_type (arg);
15756 sub_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg, NULL);
15758 /* We don't copy orig_targs for this because if we have already deduced
15759 some template args from previous args, unify would complain when we
15760 try to deduce a template parameter for the same argument, even though
15761 there isn't really a conflict. */
15762 nargs = TREE_VEC_LENGTH (targs);
15763 tempargs = make_tree_vec (nargs);
15765 if (unify (tparms, tempargs, parm, arg, sub_strict, explain_p))
15768 /* First make sure we didn't deduce anything that conflicts with
15769 explicitly specified args. */
15770 for (i = nargs; i--; )
15772 tree elt = TREE_VEC_ELT (tempargs, i);
15773 tree oldelt = TREE_VEC_ELT (orig_targs, i);
15777 else if (uses_template_parms (elt))
15778 /* Since we're unifying against ourselves, we will fill in
15779 template args used in the function parm list with our own
15780 template parms. Discard them. */
15781 TREE_VEC_ELT (tempargs, i) = NULL_TREE;
15782 else if (oldelt && !template_args_equal (oldelt, elt))
15786 for (i = nargs; i--; )
15788 tree elt = TREE_VEC_ELT (tempargs, i);
15791 TREE_VEC_ELT (targs, i) = elt;
15797 /* PARM is a template class (perhaps with unbound template
15798 parameters). ARG is a fully instantiated type. If ARG can be
15799 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
15800 TARGS are as for unify. */
15803 try_class_unification (tree tparms, tree targs, tree parm, tree arg,
15806 tree copy_of_targs;
15808 if (!CLASSTYPE_TEMPLATE_INFO (arg)
15809 || (most_general_template (CLASSTYPE_TI_TEMPLATE (arg))
15810 != most_general_template (CLASSTYPE_TI_TEMPLATE (parm))))
15813 /* We need to make a new template argument vector for the call to
15814 unify. If we used TARGS, we'd clutter it up with the result of
15815 the attempted unification, even if this class didn't work out.
15816 We also don't want to commit ourselves to all the unifications
15817 we've already done, since unification is supposed to be done on
15818 an argument-by-argument basis. In other words, consider the
15819 following pathological case:
15821 template <int I, int J, int K>
15824 template <int I, int J>
15825 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
15827 template <int I, int J, int K>
15828 void f(S<I, J, K>, S<I, I, I>);
15837 Now, by the time we consider the unification involving `s2', we
15838 already know that we must have `f<0, 0, 0>'. But, even though
15839 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
15840 because there are two ways to unify base classes of S<0, 1, 2>
15841 with S<I, I, I>. If we kept the already deduced knowledge, we
15842 would reject the possibility I=1. */
15843 copy_of_targs = make_tree_vec (TREE_VEC_LENGTH (targs));
15845 /* If unification failed, we're done. */
15846 if (unify (tparms, copy_of_targs, CLASSTYPE_TI_ARGS (parm),
15847 CLASSTYPE_TI_ARGS (arg), UNIFY_ALLOW_NONE, explain_p))
15853 /* Given a template type PARM and a class type ARG, find the unique
15854 base type in ARG that is an instance of PARM. We do not examine
15855 ARG itself; only its base-classes. If there is not exactly one
15856 appropriate base class, return NULL_TREE. PARM may be the type of
15857 a partial specialization, as well as a plain template type. Used
15860 static enum template_base_result
15861 get_template_base (tree tparms, tree targs, tree parm, tree arg,
15862 bool explain_p, tree *result)
15864 tree rval = NULL_TREE;
15867 gcc_assert (RECORD_OR_UNION_CODE_P (TREE_CODE (arg)));
15869 binfo = TYPE_BINFO (complete_type (arg));
15872 /* The type could not be completed. */
15873 *result = NULL_TREE;
15874 return tbr_incomplete_type;
15877 /* Walk in inheritance graph order. The search order is not
15878 important, and this avoids multiple walks of virtual bases. */
15879 for (binfo = TREE_CHAIN (binfo); binfo; binfo = TREE_CHAIN (binfo))
15881 tree r = try_class_unification (tparms, targs, parm,
15882 BINFO_TYPE (binfo), explain_p);
15886 /* If there is more than one satisfactory baseclass, then:
15890 If they yield more than one possible deduced A, the type
15894 if (rval && !same_type_p (r, rval))
15896 *result = NULL_TREE;
15897 return tbr_ambiguous_baseclass;
15905 return tbr_success;
15908 /* Returns the level of DECL, which declares a template parameter. */
15911 template_decl_level (tree decl)
15913 switch (TREE_CODE (decl))
15916 case TEMPLATE_DECL:
15917 return TEMPLATE_TYPE_LEVEL (TREE_TYPE (decl));
15920 return TEMPLATE_PARM_LEVEL (DECL_INITIAL (decl));
15923 gcc_unreachable ();
15928 /* Decide whether ARG can be unified with PARM, considering only the
15929 cv-qualifiers of each type, given STRICT as documented for unify.
15930 Returns nonzero iff the unification is OK on that basis. */
15933 check_cv_quals_for_unify (int strict, tree arg, tree parm)
15935 int arg_quals = cp_type_quals (arg);
15936 int parm_quals = cp_type_quals (parm);
15938 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
15939 && !(strict & UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
15941 /* Although a CVR qualifier is ignored when being applied to a
15942 substituted template parameter ([8.3.2]/1 for example), that
15943 does not allow us to unify "const T" with "int&" because both
15944 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
15945 It is ok when we're allowing additional CV qualifiers
15946 at the outer level [14.8.2.1]/3,1st bullet. */
15947 if ((TREE_CODE (arg) == REFERENCE_TYPE
15948 || TREE_CODE (arg) == FUNCTION_TYPE
15949 || TREE_CODE (arg) == METHOD_TYPE)
15950 && (parm_quals & (TYPE_QUAL_CONST | TYPE_QUAL_VOLATILE)))
15953 if ((!POINTER_TYPE_P (arg) && TREE_CODE (arg) != TEMPLATE_TYPE_PARM)
15954 && (parm_quals & TYPE_QUAL_RESTRICT))
15958 if (!(strict & (UNIFY_ALLOW_MORE_CV_QUAL | UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
15959 && (arg_quals & parm_quals) != parm_quals)
15962 if (!(strict & (UNIFY_ALLOW_LESS_CV_QUAL | UNIFY_ALLOW_OUTER_LESS_CV_QUAL))
15963 && (parm_quals & arg_quals) != arg_quals)
15969 /* Determines the LEVEL and INDEX for the template parameter PARM. */
15971 template_parm_level_and_index (tree parm, int* level, int* index)
15973 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
15974 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
15975 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
15977 *index = TEMPLATE_TYPE_IDX (parm);
15978 *level = TEMPLATE_TYPE_LEVEL (parm);
15982 *index = TEMPLATE_PARM_IDX (parm);
15983 *level = TEMPLATE_PARM_LEVEL (parm);
15987 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
15989 if (unify (TP, TA, P, A, S, EP)) \
15993 /* Unifies the remaining arguments in PACKED_ARGS with the pack
15994 expansion at the end of PACKED_PARMS. Returns 0 if the type
15995 deduction succeeds, 1 otherwise. STRICT is the same as in
15996 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
15997 call argument list. We'll need to adjust the arguments to make them
15998 types. SUBR tells us if this is from a recursive call to
15999 type_unification_real, or for comparing two template argument
16003 unify_pack_expansion (tree tparms, tree targs, tree packed_parms,
16004 tree packed_args, unification_kind_t strict,
16005 bool subr, bool explain_p)
16008 = TREE_VEC_ELT (packed_parms, TREE_VEC_LENGTH (packed_parms) - 1);
16009 tree pattern = PACK_EXPANSION_PATTERN (parm);
16010 tree pack, packs = NULL_TREE;
16011 int i, start = TREE_VEC_LENGTH (packed_parms) - 1;
16012 int len = TREE_VEC_LENGTH (packed_args);
16014 /* Determine the parameter packs we will be deducing from the
16015 pattern, and record their current deductions. */
16016 for (pack = PACK_EXPANSION_PARAMETER_PACKS (parm);
16017 pack; pack = TREE_CHAIN (pack))
16019 tree parm_pack = TREE_VALUE (pack);
16022 /* Determine the index and level of this parameter pack. */
16023 template_parm_level_and_index (parm_pack, &level, &idx);
16025 /* Keep track of the parameter packs and their corresponding
16027 packs = tree_cons (parm_pack, TMPL_ARG (targs, level, idx), packs);
16028 TREE_TYPE (packs) = make_tree_vec (len - start);
16031 /* Loop through all of the arguments that have not yet been
16032 unified and unify each with the pattern. */
16033 for (i = start; i < len; i++)
16036 bool any_explicit = false;
16037 tree arg = TREE_VEC_ELT (packed_args, i);
16039 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
16040 or the element of its argument pack at the current index if
16041 this argument was explicitly specified. */
16042 for (pack = packs; pack; pack = TREE_CHAIN (pack))
16046 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
16049 if (TREE_VALUE (pack)
16050 && (pargs = ARGUMENT_PACK_EXPLICIT_ARGS (TREE_VALUE (pack)))
16051 && (i < TREE_VEC_LENGTH (pargs)))
16053 any_explicit = true;
16054 arg = TREE_VEC_ELT (pargs, i);
16056 TMPL_ARG (targs, level, idx) = arg;
16059 /* If we had explicit template arguments, substitute them into the
16060 pattern before deduction. */
16063 /* Some arguments might still be unspecified or dependent. */
16065 ++processing_template_decl;
16066 dependent = any_dependent_template_arguments_p (targs);
16068 --processing_template_decl;
16069 parm = tsubst (pattern, targs,
16070 explain_p ? tf_warning_or_error : tf_none,
16073 --processing_template_decl;
16074 if (parm == error_mark_node)
16080 /* Unify the pattern with the current argument. */
16081 if (unify_one_argument (tparms, targs, parm, arg, subr, strict,
16082 LOOKUP_IMPLICIT, explain_p))
16085 /* For each parameter pack, collect the deduced value. */
16086 for (pack = packs; pack; pack = TREE_CHAIN (pack))
16089 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
16091 TREE_VEC_ELT (TREE_TYPE (pack), i - start) =
16092 TMPL_ARG (targs, level, idx);
16096 /* Verify that the results of unification with the parameter packs
16097 produce results consistent with what we've seen before, and make
16098 the deduced argument packs available. */
16099 for (pack = packs; pack; pack = TREE_CHAIN (pack))
16101 tree old_pack = TREE_VALUE (pack);
16102 tree new_args = TREE_TYPE (pack);
16103 int i, len = TREE_VEC_LENGTH (new_args);
16105 bool nondeduced_p = false;
16107 /* By default keep the original deduced argument pack.
16108 If necessary, more specific code is going to update the
16109 resulting deduced argument later down in this function. */
16110 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
16111 TMPL_ARG (targs, level, idx) = old_pack;
16113 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
16114 actually deduce anything. */
16115 for (i = 0; i < len && !nondeduced_p; ++i)
16116 if (TREE_VEC_ELT (new_args, i) == NULL_TREE)
16117 nondeduced_p = true;
16121 if (old_pack && ARGUMENT_PACK_INCOMPLETE_P (old_pack))
16123 /* If we had fewer function args than explicit template args,
16124 just use the explicits. */
16125 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
16126 int explicit_len = TREE_VEC_LENGTH (explicit_args);
16127 if (len < explicit_len)
16128 new_args = explicit_args;
16134 /* Build the deduced *_ARGUMENT_PACK. */
16135 if (TREE_CODE (TREE_PURPOSE (pack)) == TEMPLATE_PARM_INDEX)
16137 result = make_node (NONTYPE_ARGUMENT_PACK);
16138 TREE_TYPE (result) =
16139 TREE_TYPE (TEMPLATE_PARM_DECL (TREE_PURPOSE (pack)));
16140 TREE_CONSTANT (result) = 1;
16143 result = cxx_make_type (TYPE_ARGUMENT_PACK);
16145 SET_ARGUMENT_PACK_ARGS (result, new_args);
16147 /* Note the deduced argument packs for this parameter
16149 TMPL_ARG (targs, level, idx) = result;
16151 else if (ARGUMENT_PACK_INCOMPLETE_P (old_pack)
16152 && (ARGUMENT_PACK_ARGS (old_pack)
16153 == ARGUMENT_PACK_EXPLICIT_ARGS (old_pack)))
16155 /* We only had the explicitly-provided arguments before, but
16156 now we have a complete set of arguments. */
16157 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
16159 SET_ARGUMENT_PACK_ARGS (old_pack, new_args);
16160 ARGUMENT_PACK_INCOMPLETE_P (old_pack) = 1;
16161 ARGUMENT_PACK_EXPLICIT_ARGS (old_pack) = explicit_args;
16165 tree bad_old_arg = NULL_TREE, bad_new_arg = NULL_TREE;
16166 tree old_args = ARGUMENT_PACK_ARGS (old_pack);
16168 if (!comp_template_args_with_info (old_args, new_args,
16169 &bad_old_arg, &bad_new_arg))
16170 /* Inconsistent unification of this parameter pack. */
16171 return unify_parameter_pack_inconsistent (explain_p,
16177 return unify_success (explain_p);
16180 /* Deduce the value of template parameters. TPARMS is the (innermost)
16181 set of template parameters to a template. TARGS is the bindings
16182 for those template parameters, as determined thus far; TARGS may
16183 include template arguments for outer levels of template parameters
16184 as well. PARM is a parameter to a template function, or a
16185 subcomponent of that parameter; ARG is the corresponding argument.
16186 This function attempts to match PARM with ARG in a manner
16187 consistent with the existing assignments in TARGS. If more values
16188 are deduced, then TARGS is updated.
16190 Returns 0 if the type deduction succeeds, 1 otherwise. The
16191 parameter STRICT is a bitwise or of the following flags:
16194 Require an exact match between PARM and ARG.
16195 UNIFY_ALLOW_MORE_CV_QUAL:
16196 Allow the deduced ARG to be more cv-qualified (by qualification
16197 conversion) than ARG.
16198 UNIFY_ALLOW_LESS_CV_QUAL:
16199 Allow the deduced ARG to be less cv-qualified than ARG.
16200 UNIFY_ALLOW_DERIVED:
16201 Allow the deduced ARG to be a template base class of ARG,
16202 or a pointer to a template base class of the type pointed to by
16204 UNIFY_ALLOW_INTEGER:
16205 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
16206 case for more information.
16207 UNIFY_ALLOW_OUTER_LEVEL:
16208 This is the outermost level of a deduction. Used to determine validity
16209 of qualification conversions. A valid qualification conversion must
16210 have const qualified pointers leading up to the inner type which
16211 requires additional CV quals, except at the outer level, where const
16212 is not required [conv.qual]. It would be normal to set this flag in
16213 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
16214 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
16215 This is the outermost level of a deduction, and PARM can be more CV
16216 qualified at this point.
16217 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
16218 This is the outermost level of a deduction, and PARM can be less CV
16219 qualified at this point. */
16222 unify (tree tparms, tree targs, tree parm, tree arg, int strict,
16228 int strict_in = strict;
16230 /* I don't think this will do the right thing with respect to types.
16231 But the only case I've seen it in so far has been array bounds, where
16232 signedness is the only information lost, and I think that will be
16234 while (TREE_CODE (parm) == NOP_EXPR)
16235 parm = TREE_OPERAND (parm, 0);
16237 if (arg == error_mark_node)
16238 return unify_invalid (explain_p);
16239 if (arg == unknown_type_node
16240 || arg == init_list_type_node)
16241 /* We can't deduce anything from this, but we might get all the
16242 template args from other function args. */
16243 return unify_success (explain_p);
16245 /* If PARM uses template parameters, then we can't bail out here,
16246 even if ARG == PARM, since we won't record unifications for the
16247 template parameters. We might need them if we're trying to
16248 figure out which of two things is more specialized. */
16249 if (arg == parm && !uses_template_parms (parm))
16250 return unify_success (explain_p);
16252 /* Handle init lists early, so the rest of the function can assume
16253 we're dealing with a type. */
16254 if (BRACE_ENCLOSED_INITIALIZER_P (arg))
16258 tree orig_parm = parm;
16260 /* Replace T with std::initializer_list<T> for deduction. */
16261 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
16262 && flag_deduce_init_list)
16263 parm = listify (parm);
16265 if (!is_std_init_list (parm))
16266 /* We can only deduce from an initializer list argument if the
16267 parameter is std::initializer_list; otherwise this is a
16268 non-deduced context. */
16269 return unify_success (explain_p);
16271 elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (parm), 0);
16273 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg), i, elt)
16275 int elt_strict = strict;
16277 if (elt == error_mark_node)
16278 return unify_invalid (explain_p);
16280 if (!BRACE_ENCLOSED_INITIALIZER_P (elt))
16282 tree type = TREE_TYPE (elt);
16283 /* It should only be possible to get here for a call. */
16284 gcc_assert (elt_strict & UNIFY_ALLOW_OUTER_LEVEL);
16285 elt_strict |= maybe_adjust_types_for_deduction
16286 (DEDUCE_CALL, &elttype, &type, elt);
16290 RECUR_AND_CHECK_FAILURE (tparms, targs, elttype, elt, elt_strict,
16294 /* If the std::initializer_list<T> deduction worked, replace the
16295 deduced A with std::initializer_list<A>. */
16296 if (orig_parm != parm)
16298 idx = TEMPLATE_TYPE_IDX (orig_parm);
16299 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
16300 targ = listify (targ);
16301 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = targ;
16303 return unify_success (explain_p);
16306 /* Immediately reject some pairs that won't unify because of
16307 cv-qualification mismatches. */
16308 if (TREE_CODE (arg) == TREE_CODE (parm)
16310 /* It is the elements of the array which hold the cv quals of an array
16311 type, and the elements might be template type parms. We'll check
16312 when we recurse. */
16313 && TREE_CODE (arg) != ARRAY_TYPE
16314 /* We check the cv-qualifiers when unifying with template type
16315 parameters below. We want to allow ARG `const T' to unify with
16316 PARM `T' for example, when computing which of two templates
16317 is more specialized, for example. */
16318 && TREE_CODE (arg) != TEMPLATE_TYPE_PARM
16319 && !check_cv_quals_for_unify (strict_in, arg, parm))
16320 return unify_cv_qual_mismatch (explain_p, parm, arg);
16322 if (!(strict & UNIFY_ALLOW_OUTER_LEVEL)
16323 && TYPE_P (parm) && !CP_TYPE_CONST_P (parm))
16324 strict &= ~UNIFY_ALLOW_MORE_CV_QUAL;
16325 strict &= ~UNIFY_ALLOW_OUTER_LEVEL;
16326 strict &= ~UNIFY_ALLOW_DERIVED;
16327 strict &= ~UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
16328 strict &= ~UNIFY_ALLOW_OUTER_LESS_CV_QUAL;
16330 switch (TREE_CODE (parm))
16332 case TYPENAME_TYPE:
16334 case UNBOUND_CLASS_TEMPLATE:
16335 /* In a type which contains a nested-name-specifier, template
16336 argument values cannot be deduced for template parameters used
16337 within the nested-name-specifier. */
16338 return unify_success (explain_p);
16340 case TEMPLATE_TYPE_PARM:
16341 case TEMPLATE_TEMPLATE_PARM:
16342 case BOUND_TEMPLATE_TEMPLATE_PARM:
16343 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
16344 if (tparm == error_mark_node)
16345 return unify_invalid (explain_p);
16347 if (TEMPLATE_TYPE_LEVEL (parm)
16348 != template_decl_level (tparm))
16349 /* The PARM is not one we're trying to unify. Just check
16350 to see if it matches ARG. */
16352 if (TREE_CODE (arg) == TREE_CODE (parm)
16353 && same_type_p (parm, arg))
16354 return unify_success (explain_p);
16356 return unify_type_mismatch (explain_p, parm, arg);
16358 idx = TEMPLATE_TYPE_IDX (parm);
16359 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
16360 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, idx));
16361 if (tparm == error_mark_node)
16362 return unify_invalid (explain_p);
16364 /* Check for mixed types and values. */
16365 if ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
16366 && TREE_CODE (tparm) != TYPE_DECL)
16367 || (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
16368 && TREE_CODE (tparm) != TEMPLATE_DECL))
16369 gcc_unreachable ();
16371 if (TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
16373 /* ARG must be constructed from a template class or a template
16374 template parameter. */
16375 if (TREE_CODE (arg) != BOUND_TEMPLATE_TEMPLATE_PARM
16376 && !CLASSTYPE_SPECIALIZATION_OF_PRIMARY_TEMPLATE_P (arg))
16377 return unify_template_deduction_failure (explain_p, parm, arg);
16380 tree parmvec = TYPE_TI_ARGS (parm);
16381 tree argvec = INNERMOST_TEMPLATE_ARGS (TYPE_TI_ARGS (arg));
16382 tree full_argvec = add_to_template_args (targs, argvec);
16384 = DECL_INNERMOST_TEMPLATE_PARMS
16385 (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (parm));
16387 int parm_variadic_p = 0;
16389 /* The resolution to DR150 makes clear that default
16390 arguments for an N-argument may not be used to bind T
16391 to a template template parameter with fewer than N
16392 parameters. It is not safe to permit the binding of
16393 default arguments as an extension, as that may change
16394 the meaning of a conforming program. Consider:
16396 struct Dense { static const unsigned int dim = 1; };
16398 template <template <typename> class View,
16400 void operator+(float, View<Block> const&);
16402 template <typename Block,
16403 unsigned int Dim = Block::dim>
16404 struct Lvalue_proxy { operator float() const; };
16408 Lvalue_proxy<Dense> p;
16413 Here, if Lvalue_proxy is permitted to bind to View, then
16414 the global operator+ will be used; if they are not, the
16415 Lvalue_proxy will be converted to float. */
16416 if (coerce_template_parms (parm_parms,
16418 TYPE_TI_TEMPLATE (parm),
16420 ? tf_warning_or_error
16422 /*require_all_args=*/true,
16423 /*use_default_args=*/false)
16424 == error_mark_node)
16427 /* Deduce arguments T, i from TT<T> or TT<i>.
16428 We check each element of PARMVEC and ARGVEC individually
16429 rather than the whole TREE_VEC since they can have
16430 different number of elements. */
16432 parmvec = expand_template_argument_pack (parmvec);
16433 argvec = expand_template_argument_pack (argvec);
16435 len = TREE_VEC_LENGTH (parmvec);
16437 /* Check if the parameters end in a pack, making them
16440 && PACK_EXPANSION_P (TREE_VEC_ELT (parmvec, len - 1)))
16441 parm_variadic_p = 1;
16443 if (TREE_VEC_LENGTH (argvec) < len - parm_variadic_p)
16444 return unify_too_few_arguments (explain_p,
16445 TREE_VEC_LENGTH (argvec), len);
16447 for (i = 0; i < len - parm_variadic_p; ++i)
16449 RECUR_AND_CHECK_FAILURE (tparms, targs,
16450 TREE_VEC_ELT (parmvec, i),
16451 TREE_VEC_ELT (argvec, i),
16452 UNIFY_ALLOW_NONE, explain_p);
16455 if (parm_variadic_p
16456 && unify_pack_expansion (tparms, targs,
16459 /*subr=*/true, explain_p))
16462 arg = TYPE_TI_TEMPLATE (arg);
16464 /* Fall through to deduce template name. */
16467 if (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
16468 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
16470 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
16472 /* Simple cases: Value already set, does match or doesn't. */
16473 if (targ != NULL_TREE && template_args_equal (targ, arg))
16474 return unify_success (explain_p);
16476 return unify_inconsistency (explain_p, parm, targ, arg);
16480 /* If PARM is `const T' and ARG is only `int', we don't have
16481 a match unless we are allowing additional qualification.
16482 If ARG is `const int' and PARM is just `T' that's OK;
16483 that binds `const int' to `T'. */
16484 if (!check_cv_quals_for_unify (strict_in | UNIFY_ALLOW_LESS_CV_QUAL,
16486 return unify_cv_qual_mismatch (explain_p, parm, arg);
16488 /* Consider the case where ARG is `const volatile int' and
16489 PARM is `const T'. Then, T should be `volatile int'. */
16490 arg = cp_build_qualified_type_real
16491 (arg, cp_type_quals (arg) & ~cp_type_quals (parm), tf_none);
16492 if (arg == error_mark_node)
16493 return unify_invalid (explain_p);
16495 /* Simple cases: Value already set, does match or doesn't. */
16496 if (targ != NULL_TREE && same_type_p (targ, arg))
16497 return unify_success (explain_p);
16499 return unify_inconsistency (explain_p, parm, targ, arg);
16501 /* Make sure that ARG is not a variable-sized array. (Note
16502 that were talking about variable-sized arrays (like
16503 `int[n]'), rather than arrays of unknown size (like
16504 `int[]').) We'll get very confused by such a type since
16505 the bound of the array is not constant, and therefore
16506 not mangleable. Besides, such types are not allowed in
16507 ISO C++, so we can do as we please here. We do allow
16508 them for 'auto' deduction, since that isn't ABI-exposed. */
16509 if (!is_auto (parm) && variably_modified_type_p (arg, NULL_TREE))
16510 return unify_vla_arg (explain_p, arg);
16512 /* Strip typedefs as in convert_template_argument. */
16513 arg = canonicalize_type_argument (arg, tf_none);
16516 /* If ARG is a parameter pack or an expansion, we cannot unify
16517 against it unless PARM is also a parameter pack. */
16518 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
16519 && !template_parameter_pack_p (parm))
16520 return unify_parameter_pack_mismatch (explain_p, parm, arg);
16522 /* If the argument deduction results is a METHOD_TYPE,
16523 then there is a problem.
16524 METHOD_TYPE doesn't map to any real C++ type the result of
16525 the deduction can not be of that type. */
16526 if (TREE_CODE (arg) == METHOD_TYPE)
16527 return unify_method_type_error (explain_p, arg);
16529 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
16530 return unify_success (explain_p);
16532 case TEMPLATE_PARM_INDEX:
16533 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
16534 if (tparm == error_mark_node)
16535 return unify_invalid (explain_p);
16537 if (TEMPLATE_PARM_LEVEL (parm)
16538 != template_decl_level (tparm))
16540 /* The PARM is not one we're trying to unify. Just check
16541 to see if it matches ARG. */
16542 int result = !(TREE_CODE (arg) == TREE_CODE (parm)
16543 && cp_tree_equal (parm, arg));
16545 unify_expression_unequal (explain_p, parm, arg);
16549 idx = TEMPLATE_PARM_IDX (parm);
16550 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
16554 int x = !cp_tree_equal (targ, arg);
16556 unify_inconsistency (explain_p, parm, targ, arg);
16560 /* [temp.deduct.type] If, in the declaration of a function template
16561 with a non-type template-parameter, the non-type
16562 template-parameter is used in an expression in the function
16563 parameter-list and, if the corresponding template-argument is
16564 deduced, the template-argument type shall match the type of the
16565 template-parameter exactly, except that a template-argument
16566 deduced from an array bound may be of any integral type.
16567 The non-type parameter might use already deduced type parameters. */
16568 tparm = tsubst (TREE_TYPE (parm), targs, 0, NULL_TREE);
16569 if (!TREE_TYPE (arg))
16570 /* Template-parameter dependent expression. Just accept it for now.
16571 It will later be processed in convert_template_argument. */
16573 else if (same_type_p (TREE_TYPE (arg), tparm))
16575 else if ((strict & UNIFY_ALLOW_INTEGER)
16576 && (TREE_CODE (tparm) == INTEGER_TYPE
16577 || TREE_CODE (tparm) == BOOLEAN_TYPE))
16578 /* Convert the ARG to the type of PARM; the deduced non-type
16579 template argument must exactly match the types of the
16580 corresponding parameter. */
16581 arg = fold (build_nop (tparm, arg));
16582 else if (uses_template_parms (tparm))
16583 /* We haven't deduced the type of this parameter yet. Try again
16585 return unify_success (explain_p);
16587 return unify_type_mismatch (explain_p, tparm, arg);
16589 /* If ARG is a parameter pack or an expansion, we cannot unify
16590 against it unless PARM is also a parameter pack. */
16591 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
16592 && !TEMPLATE_PARM_PARAMETER_PACK (parm))
16593 return unify_parameter_pack_mismatch (explain_p, parm, arg);
16595 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
16596 return unify_success (explain_p);
16600 /* A pointer-to-member constant can be unified only with
16601 another constant. */
16602 if (TREE_CODE (arg) != PTRMEM_CST)
16603 return unify_ptrmem_cst_mismatch (explain_p, parm, arg);
16605 /* Just unify the class member. It would be useless (and possibly
16606 wrong, depending on the strict flags) to unify also
16607 PTRMEM_CST_CLASS, because we want to be sure that both parm and
16608 arg refer to the same variable, even if through different
16609 classes. For instance:
16611 struct A { int x; };
16614 Unification of &A::x and &B::x must succeed. */
16615 return unify (tparms, targs, PTRMEM_CST_MEMBER (parm),
16616 PTRMEM_CST_MEMBER (arg), strict, explain_p);
16621 if (TREE_CODE (arg) != POINTER_TYPE)
16622 return unify_type_mismatch (explain_p, parm, arg);
16624 /* [temp.deduct.call]
16626 A can be another pointer or pointer to member type that can
16627 be converted to the deduced A via a qualification
16628 conversion (_conv.qual_).
16630 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
16631 This will allow for additional cv-qualification of the
16632 pointed-to types if appropriate. */
16634 if (TREE_CODE (TREE_TYPE (arg)) == RECORD_TYPE)
16635 /* The derived-to-base conversion only persists through one
16636 level of pointers. */
16637 strict |= (strict_in & UNIFY_ALLOW_DERIVED);
16639 return unify (tparms, targs, TREE_TYPE (parm),
16640 TREE_TYPE (arg), strict, explain_p);
16643 case REFERENCE_TYPE:
16644 if (TREE_CODE (arg) != REFERENCE_TYPE)
16645 return unify_type_mismatch (explain_p, parm, arg);
16646 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
16647 strict & UNIFY_ALLOW_MORE_CV_QUAL, explain_p);
16650 if (TREE_CODE (arg) != ARRAY_TYPE)
16651 return unify_type_mismatch (explain_p, parm, arg);
16652 if ((TYPE_DOMAIN (parm) == NULL_TREE)
16653 != (TYPE_DOMAIN (arg) == NULL_TREE))
16654 return unify_type_mismatch (explain_p, parm, arg);
16655 if (TYPE_DOMAIN (parm) != NULL_TREE)
16662 /* Our representation of array types uses "N - 1" as the
16663 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
16664 not an integer constant. We cannot unify arbitrarily
16665 complex expressions, so we eliminate the MINUS_EXPRs
16667 parm_max = TYPE_MAX_VALUE (TYPE_DOMAIN (parm));
16668 parm_cst = TREE_CODE (parm_max) == INTEGER_CST;
16671 gcc_assert (TREE_CODE (parm_max) == MINUS_EXPR);
16672 parm_max = TREE_OPERAND (parm_max, 0);
16674 arg_max = TYPE_MAX_VALUE (TYPE_DOMAIN (arg));
16675 arg_cst = TREE_CODE (arg_max) == INTEGER_CST;
16678 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
16679 trying to unify the type of a variable with the type
16680 of a template parameter. For example:
16682 template <unsigned int N>
16683 void f (char (&) [N]);
16690 Here, the type of the ARG will be "int [g(i)]", and
16691 may be a SAVE_EXPR, etc. */
16692 if (TREE_CODE (arg_max) != MINUS_EXPR)
16693 return unify_vla_arg (explain_p, arg);
16694 arg_max = TREE_OPERAND (arg_max, 0);
16697 /* If only one of the bounds used a MINUS_EXPR, compensate
16698 by adding one to the other bound. */
16699 if (parm_cst && !arg_cst)
16700 parm_max = fold_build2_loc (input_location, PLUS_EXPR,
16704 else if (arg_cst && !parm_cst)
16705 arg_max = fold_build2_loc (input_location, PLUS_EXPR,
16710 RECUR_AND_CHECK_FAILURE (tparms, targs, parm_max, arg_max,
16711 UNIFY_ALLOW_INTEGER, explain_p);
16713 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
16714 strict & UNIFY_ALLOW_MORE_CV_QUAL, explain_p);
16721 case ENUMERAL_TYPE:
16724 if (TREE_CODE (arg) != TREE_CODE (parm))
16725 return unify_type_mismatch (explain_p, parm, arg);
16727 /* We have already checked cv-qualification at the top of the
16729 if (!same_type_ignoring_top_level_qualifiers_p (arg, parm))
16730 return unify_type_mismatch (explain_p, parm, arg);
16732 /* As far as unification is concerned, this wins. Later checks
16733 will invalidate it if necessary. */
16734 return unify_success (explain_p);
16736 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
16737 /* Type INTEGER_CST can come from ordinary constant template args. */
16739 while (TREE_CODE (arg) == NOP_EXPR)
16740 arg = TREE_OPERAND (arg, 0);
16742 if (TREE_CODE (arg) != INTEGER_CST)
16743 return unify_template_argument_mismatch (explain_p, parm, arg);
16744 return (tree_int_cst_equal (parm, arg)
16745 ? unify_success (explain_p)
16746 : unify_template_argument_mismatch (explain_p, parm, arg));
16750 int i, len, argslen;
16751 int parm_variadic_p = 0;
16753 if (TREE_CODE (arg) != TREE_VEC)
16754 return unify_template_argument_mismatch (explain_p, parm, arg);
16756 len = TREE_VEC_LENGTH (parm);
16757 argslen = TREE_VEC_LENGTH (arg);
16759 /* Check for pack expansions in the parameters. */
16760 for (i = 0; i < len; ++i)
16762 if (PACK_EXPANSION_P (TREE_VEC_ELT (parm, i)))
16765 /* We can unify against something with a trailing
16767 parm_variadic_p = 1;
16769 /* [temp.deduct.type]/9: If the template argument list of
16770 P contains a pack expansion that is not the last
16771 template argument, the entire template argument list
16772 is a non-deduced context. */
16773 return unify_success (explain_p);
16777 /* If we don't have enough arguments to satisfy the parameters
16778 (not counting the pack expression at the end), or we have
16779 too many arguments for a parameter list that doesn't end in
16780 a pack expression, we can't unify. */
16781 if (parm_variadic_p
16782 ? argslen < len - parm_variadic_p
16784 return unify_arity (explain_p, TREE_VEC_LENGTH (arg), len);
16786 /* Unify all of the parameters that precede the (optional)
16787 pack expression. */
16788 for (i = 0; i < len - parm_variadic_p; ++i)
16790 RECUR_AND_CHECK_FAILURE (tparms, targs,
16791 TREE_VEC_ELT (parm, i),
16792 TREE_VEC_ELT (arg, i),
16793 UNIFY_ALLOW_NONE, explain_p);
16795 if (parm_variadic_p)
16796 return unify_pack_expansion (tparms, targs, parm, arg,
16798 /*subr=*/true, explain_p);
16799 return unify_success (explain_p);
16804 if (TREE_CODE (arg) != TREE_CODE (parm))
16805 return unify_type_mismatch (explain_p, parm, arg);
16807 if (TYPE_PTRMEMFUNC_P (parm))
16809 if (!TYPE_PTRMEMFUNC_P (arg))
16810 return unify_type_mismatch (explain_p, parm, arg);
16812 return unify (tparms, targs,
16813 TYPE_PTRMEMFUNC_FN_TYPE (parm),
16814 TYPE_PTRMEMFUNC_FN_TYPE (arg),
16815 strict, explain_p);
16818 if (CLASSTYPE_TEMPLATE_INFO (parm))
16820 tree t = NULL_TREE;
16822 if (strict_in & UNIFY_ALLOW_DERIVED)
16824 /* First, we try to unify the PARM and ARG directly. */
16825 t = try_class_unification (tparms, targs,
16826 parm, arg, explain_p);
16830 /* Fallback to the special case allowed in
16831 [temp.deduct.call]:
16833 If P is a class, and P has the form
16834 template-id, then A can be a derived class of
16835 the deduced A. Likewise, if P is a pointer to
16836 a class of the form template-id, A can be a
16837 pointer to a derived class pointed to by the
16839 enum template_base_result r;
16840 r = get_template_base (tparms, targs, parm, arg,
16844 return unify_no_common_base (explain_p, r, parm, arg);
16847 else if (CLASSTYPE_TEMPLATE_INFO (arg)
16848 && (CLASSTYPE_TI_TEMPLATE (parm)
16849 == CLASSTYPE_TI_TEMPLATE (arg)))
16850 /* Perhaps PARM is something like S<U> and ARG is S<int>.
16851 Then, we should unify `int' and `U'. */
16854 /* There's no chance of unification succeeding. */
16855 return unify_type_mismatch (explain_p, parm, arg);
16857 return unify (tparms, targs, CLASSTYPE_TI_ARGS (parm),
16858 CLASSTYPE_TI_ARGS (t), UNIFY_ALLOW_NONE, explain_p);
16860 else if (!same_type_ignoring_top_level_qualifiers_p (parm, arg))
16861 return unify_type_mismatch (explain_p, parm, arg);
16862 return unify_success (explain_p);
16865 case FUNCTION_TYPE:
16867 unsigned int nargs;
16872 if (TREE_CODE (arg) != TREE_CODE (parm))
16873 return unify_type_mismatch (explain_p, parm, arg);
16875 /* CV qualifications for methods can never be deduced, they must
16876 match exactly. We need to check them explicitly here,
16877 because type_unification_real treats them as any other
16878 cv-qualified parameter. */
16879 if (TREE_CODE (parm) == METHOD_TYPE
16880 && (!check_cv_quals_for_unify
16882 class_of_this_parm (arg),
16883 class_of_this_parm (parm))))
16884 return unify_cv_qual_mismatch (explain_p, parm, arg);
16886 RECUR_AND_CHECK_FAILURE (tparms, targs, TREE_TYPE (parm),
16887 TREE_TYPE (arg), UNIFY_ALLOW_NONE, explain_p);
16889 nargs = list_length (TYPE_ARG_TYPES (arg));
16890 args = XALLOCAVEC (tree, nargs);
16891 for (a = TYPE_ARG_TYPES (arg), i = 0;
16892 a != NULL_TREE && a != void_list_node;
16893 a = TREE_CHAIN (a), ++i)
16894 args[i] = TREE_VALUE (a);
16897 return type_unification_real (tparms, targs, TYPE_ARG_TYPES (parm),
16898 args, nargs, 1, DEDUCE_EXACT,
16899 LOOKUP_NORMAL, explain_p);
16903 /* Unify a pointer to member with a pointer to member function, which
16904 deduces the type of the member as a function type. */
16905 if (TYPE_PTRMEMFUNC_P (arg))
16910 /* Check top-level cv qualifiers */
16911 if (!check_cv_quals_for_unify (UNIFY_ALLOW_NONE, arg, parm))
16912 return unify_cv_qual_mismatch (explain_p, parm, arg);
16914 RECUR_AND_CHECK_FAILURE (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
16915 TYPE_PTRMEMFUNC_OBJECT_TYPE (arg),
16916 UNIFY_ALLOW_NONE, explain_p);
16918 /* Determine the type of the function we are unifying against. */
16919 method_type = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (arg));
16921 build_function_type (TREE_TYPE (method_type),
16922 TREE_CHAIN (TYPE_ARG_TYPES (method_type)));
16924 /* Extract the cv-qualifiers of the member function from the
16925 implicit object parameter and place them on the function
16926 type to be restored later. */
16927 fntype = apply_memfn_quals (fntype, type_memfn_quals (method_type));
16928 return unify (tparms, targs, TREE_TYPE (parm), fntype, strict, explain_p);
16931 if (TREE_CODE (arg) != OFFSET_TYPE)
16932 return unify_type_mismatch (explain_p, parm, arg);
16933 RECUR_AND_CHECK_FAILURE (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
16934 TYPE_OFFSET_BASETYPE (arg),
16935 UNIFY_ALLOW_NONE, explain_p);
16936 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
16937 strict, explain_p);
16940 if (DECL_TEMPLATE_PARM_P (parm))
16941 return unify (tparms, targs, DECL_INITIAL (parm), arg, strict, explain_p);
16942 if (arg != integral_constant_value (parm))
16943 return unify_template_argument_mismatch (explain_p, parm, arg);
16944 return unify_success (explain_p);
16947 case TEMPLATE_DECL:
16948 /* Matched cases are handled by the ARG == PARM test above. */
16949 return unify_template_argument_mismatch (explain_p, parm, arg);
16952 /* A non-type template parameter that is a variable should be a
16953 an integral constant, in which case, it whould have been
16954 folded into its (constant) value. So we should not be getting
16955 a variable here. */
16956 gcc_unreachable ();
16958 case TYPE_ARGUMENT_PACK:
16959 case NONTYPE_ARGUMENT_PACK:
16960 return unify (tparms, targs, ARGUMENT_PACK_ARGS (parm),
16961 ARGUMENT_PACK_ARGS (arg), strict, explain_p);
16964 case DECLTYPE_TYPE:
16965 case UNDERLYING_TYPE:
16966 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
16967 or UNDERLYING_TYPE nodes. */
16968 return unify_success (explain_p);
16971 /* Unification fails if we hit an error node. */
16972 return unify_invalid (explain_p);
16975 /* An unresolved overload is a nondeduced context. */
16976 if (is_overloaded_fn (parm) || type_unknown_p (parm))
16977 return unify_success (explain_p);
16978 gcc_assert (EXPR_P (parm));
16980 /* We must be looking at an expression. This can happen with
16984 void foo(S<I>, S<I + 2>);
16986 This is a "nondeduced context":
16990 The nondeduced contexts are:
16992 --A type that is a template-id in which one or more of
16993 the template-arguments is an expression that references
16994 a template-parameter.
16996 In these cases, we assume deduction succeeded, but don't
16997 actually infer any unifications. */
16999 if (!uses_template_parms (parm)
17000 && !template_args_equal (parm, arg))
17001 return unify_expression_unequal (explain_p, parm, arg);
17003 return unify_success (explain_p);
17006 #undef RECUR_AND_CHECK_FAILURE
17008 /* Note that DECL can be defined in this translation unit, if
17012 mark_definable (tree decl)
17015 DECL_NOT_REALLY_EXTERN (decl) = 1;
17016 FOR_EACH_CLONE (clone, decl)
17017 DECL_NOT_REALLY_EXTERN (clone) = 1;
17020 /* Called if RESULT is explicitly instantiated, or is a member of an
17021 explicitly instantiated class. */
17024 mark_decl_instantiated (tree result, int extern_p)
17026 SET_DECL_EXPLICIT_INSTANTIATION (result);
17028 /* If this entity has already been written out, it's too late to
17029 make any modifications. */
17030 if (TREE_ASM_WRITTEN (result))
17033 if (TREE_CODE (result) != FUNCTION_DECL)
17034 /* The TREE_PUBLIC flag for function declarations will have been
17035 set correctly by tsubst. */
17036 TREE_PUBLIC (result) = 1;
17038 /* This might have been set by an earlier implicit instantiation. */
17039 DECL_COMDAT (result) = 0;
17042 DECL_NOT_REALLY_EXTERN (result) = 0;
17045 mark_definable (result);
17046 /* Always make artificials weak. */
17047 if (DECL_ARTIFICIAL (result) && flag_weak)
17048 comdat_linkage (result);
17049 /* For WIN32 we also want to put explicit instantiations in
17050 linkonce sections. */
17051 else if (TREE_PUBLIC (result))
17052 maybe_make_one_only (result);
17055 /* If EXTERN_P, then this function will not be emitted -- unless
17056 followed by an explicit instantiation, at which point its linkage
17057 will be adjusted. If !EXTERN_P, then this function will be
17058 emitted here. In neither circumstance do we want
17059 import_export_decl to adjust the linkage. */
17060 DECL_INTERFACE_KNOWN (result) = 1;
17063 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
17064 important template arguments. If any are missing, we check whether
17065 they're important by using error_mark_node for substituting into any
17066 args that were used for partial ordering (the ones between ARGS and END)
17067 and seeing if it bubbles up. */
17070 check_undeduced_parms (tree targs, tree args, tree end)
17072 bool found = false;
17074 for (i = TREE_VEC_LENGTH (targs) - 1; i >= 0; --i)
17075 if (TREE_VEC_ELT (targs, i) == NULL_TREE)
17078 TREE_VEC_ELT (targs, i) = error_mark_node;
17082 for (; args != end; args = TREE_CHAIN (args))
17084 tree substed = tsubst (TREE_VALUE (args), targs, tf_none, NULL_TREE);
17085 if (substed == error_mark_node)
17092 /* Given two function templates PAT1 and PAT2, return:
17094 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
17095 -1 if PAT2 is more specialized than PAT1.
17096 0 if neither is more specialized.
17098 LEN indicates the number of parameters we should consider
17099 (defaulted parameters should not be considered).
17101 The 1998 std underspecified function template partial ordering, and
17102 DR214 addresses the issue. We take pairs of arguments, one from
17103 each of the templates, and deduce them against each other. One of
17104 the templates will be more specialized if all the *other*
17105 template's arguments deduce against its arguments and at least one
17106 of its arguments *does* *not* deduce against the other template's
17107 corresponding argument. Deduction is done as for class templates.
17108 The arguments used in deduction have reference and top level cv
17109 qualifiers removed. Iff both arguments were originally reference
17110 types *and* deduction succeeds in both directions, the template
17111 with the more cv-qualified argument wins for that pairing (if
17112 neither is more cv-qualified, they both are equal). Unlike regular
17113 deduction, after all the arguments have been deduced in this way,
17114 we do *not* verify the deduced template argument values can be
17115 substituted into non-deduced contexts.
17117 The logic can be a bit confusing here, because we look at deduce1 and
17118 targs1 to see if pat2 is at least as specialized, and vice versa; if we
17119 can find template arguments for pat1 to make arg1 look like arg2, that
17120 means that arg2 is at least as specialized as arg1. */
17123 more_specialized_fn (tree pat1, tree pat2, int len)
17125 tree decl1 = DECL_TEMPLATE_RESULT (pat1);
17126 tree decl2 = DECL_TEMPLATE_RESULT (pat2);
17127 tree targs1 = make_tree_vec (DECL_NTPARMS (pat1));
17128 tree targs2 = make_tree_vec (DECL_NTPARMS (pat2));
17129 tree tparms1 = DECL_INNERMOST_TEMPLATE_PARMS (pat1);
17130 tree tparms2 = DECL_INNERMOST_TEMPLATE_PARMS (pat2);
17131 tree args1 = TYPE_ARG_TYPES (TREE_TYPE (decl1));
17132 tree args2 = TYPE_ARG_TYPES (TREE_TYPE (decl2));
17133 tree origs1, origs2;
17134 bool lose1 = false;
17135 bool lose2 = false;
17137 /* Remove the this parameter from non-static member functions. If
17138 one is a non-static member function and the other is not a static
17139 member function, remove the first parameter from that function
17140 also. This situation occurs for operator functions where we
17141 locate both a member function (with this pointer) and non-member
17142 operator (with explicit first operand). */
17143 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl1))
17145 len--; /* LEN is the number of significant arguments for DECL1 */
17146 args1 = TREE_CHAIN (args1);
17147 if (!DECL_STATIC_FUNCTION_P (decl2))
17148 args2 = TREE_CHAIN (args2);
17150 else if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl2))
17152 args2 = TREE_CHAIN (args2);
17153 if (!DECL_STATIC_FUNCTION_P (decl1))
17156 args1 = TREE_CHAIN (args1);
17160 /* If only one is a conversion operator, they are unordered. */
17161 if (DECL_CONV_FN_P (decl1) != DECL_CONV_FN_P (decl2))
17164 /* Consider the return type for a conversion function */
17165 if (DECL_CONV_FN_P (decl1))
17167 args1 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl1)), args1);
17168 args2 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl2)), args2);
17172 processing_template_decl++;
17178 /* Stop when an ellipsis is seen. */
17179 && args1 != NULL_TREE && args2 != NULL_TREE)
17181 tree arg1 = TREE_VALUE (args1);
17182 tree arg2 = TREE_VALUE (args2);
17183 int deduce1, deduce2;
17187 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
17188 && TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
17190 /* When both arguments are pack expansions, we need only
17191 unify the patterns themselves. */
17192 arg1 = PACK_EXPANSION_PATTERN (arg1);
17193 arg2 = PACK_EXPANSION_PATTERN (arg2);
17195 /* This is the last comparison we need to do. */
17199 if (TREE_CODE (arg1) == REFERENCE_TYPE)
17201 arg1 = TREE_TYPE (arg1);
17202 quals1 = cp_type_quals (arg1);
17205 if (TREE_CODE (arg2) == REFERENCE_TYPE)
17207 arg2 = TREE_TYPE (arg2);
17208 quals2 = cp_type_quals (arg2);
17211 if ((quals1 < 0) != (quals2 < 0))
17213 /* Only of the args is a reference, see if we should apply
17214 array/function pointer decay to it. This is not part of
17215 DR214, but is, IMHO, consistent with the deduction rules
17216 for the function call itself, and with our earlier
17217 implementation of the underspecified partial ordering
17218 rules. (nathan). */
17221 switch (TREE_CODE (arg1))
17224 arg1 = TREE_TYPE (arg1);
17226 case FUNCTION_TYPE:
17227 arg1 = build_pointer_type (arg1);
17236 switch (TREE_CODE (arg2))
17239 arg2 = TREE_TYPE (arg2);
17241 case FUNCTION_TYPE:
17242 arg2 = build_pointer_type (arg2);
17251 arg1 = TYPE_MAIN_VARIANT (arg1);
17252 arg2 = TYPE_MAIN_VARIANT (arg2);
17254 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION)
17256 int i, len2 = list_length (args2);
17257 tree parmvec = make_tree_vec (1);
17258 tree argvec = make_tree_vec (len2);
17261 /* Setup the parameter vector, which contains only ARG1. */
17262 TREE_VEC_ELT (parmvec, 0) = arg1;
17264 /* Setup the argument vector, which contains the remaining
17266 for (i = 0; i < len2; i++, ta = TREE_CHAIN (ta))
17267 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
17269 deduce1 = (unify_pack_expansion (tparms1, targs1, parmvec,
17270 argvec, DEDUCE_EXACT,
17271 /*subr=*/true, /*explain_p=*/false)
17274 /* We cannot deduce in the other direction, because ARG1 is
17275 a pack expansion but ARG2 is not. */
17278 else if (TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
17280 int i, len1 = list_length (args1);
17281 tree parmvec = make_tree_vec (1);
17282 tree argvec = make_tree_vec (len1);
17285 /* Setup the parameter vector, which contains only ARG1. */
17286 TREE_VEC_ELT (parmvec, 0) = arg2;
17288 /* Setup the argument vector, which contains the remaining
17290 for (i = 0; i < len1; i++, ta = TREE_CHAIN (ta))
17291 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
17293 deduce2 = (unify_pack_expansion (tparms2, targs2, parmvec,
17294 argvec, DEDUCE_EXACT,
17295 /*subr=*/true, /*explain_p=*/false)
17298 /* We cannot deduce in the other direction, because ARG2 is
17299 a pack expansion but ARG1 is not.*/
17305 /* The normal case, where neither argument is a pack
17307 deduce1 = (unify (tparms1, targs1, arg1, arg2,
17308 UNIFY_ALLOW_NONE, /*explain_p=*/false)
17310 deduce2 = (unify (tparms2, targs2, arg2, arg1,
17311 UNIFY_ALLOW_NONE, /*explain_p=*/false)
17315 /* If we couldn't deduce arguments for tparms1 to make arg1 match
17316 arg2, then arg2 is not as specialized as arg1. */
17322 /* "If, for a given type, deduction succeeds in both directions
17323 (i.e., the types are identical after the transformations above)
17324 and if the type from the argument template is more cv-qualified
17325 than the type from the parameter template (as described above)
17326 that type is considered to be more specialized than the other. If
17327 neither type is more cv-qualified than the other then neither type
17328 is more specialized than the other." */
17330 if (deduce1 && deduce2
17331 && quals1 != quals2 && quals1 >= 0 && quals2 >= 0)
17333 if ((quals1 & quals2) == quals2)
17335 if ((quals1 & quals2) == quals1)
17339 if (lose1 && lose2)
17340 /* We've failed to deduce something in either direction.
17341 These must be unordered. */
17344 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
17345 || TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
17346 /* We have already processed all of the arguments in our
17347 handing of the pack expansion type. */
17350 args1 = TREE_CHAIN (args1);
17351 args2 = TREE_CHAIN (args2);
17354 /* "In most cases, all template parameters must have values in order for
17355 deduction to succeed, but for partial ordering purposes a template
17356 parameter may remain without a value provided it is not used in the
17357 types being used for partial ordering."
17359 Thus, if we are missing any of the targs1 we need to substitute into
17360 origs1, then pat2 is not as specialized as pat1. This can happen when
17361 there is a nondeduced context. */
17362 if (!lose2 && check_undeduced_parms (targs1, origs1, args1))
17364 if (!lose1 && check_undeduced_parms (targs2, origs2, args2))
17367 processing_template_decl--;
17369 /* All things being equal, if the next argument is a pack expansion
17370 for one function but not for the other, prefer the
17371 non-variadic function. FIXME this is bogus; see c++/41958. */
17373 && args1 && TREE_VALUE (args1)
17374 && args2 && TREE_VALUE (args2))
17376 lose1 = TREE_CODE (TREE_VALUE (args1)) == TYPE_PACK_EXPANSION;
17377 lose2 = TREE_CODE (TREE_VALUE (args2)) == TYPE_PACK_EXPANSION;
17380 if (lose1 == lose2)
17388 /* Determine which of two partial specializations is more specialized.
17390 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
17391 to the first partial specialization. The TREE_VALUE is the
17392 innermost set of template parameters for the partial
17393 specialization. PAT2 is similar, but for the second template.
17395 Return 1 if the first partial specialization is more specialized;
17396 -1 if the second is more specialized; 0 if neither is more
17399 See [temp.class.order] for information about determining which of
17400 two templates is more specialized. */
17403 more_specialized_class (tree pat1, tree pat2)
17408 bool any_deductions = false;
17410 tmpl1 = TREE_TYPE (pat1);
17411 tmpl2 = TREE_TYPE (pat2);
17413 /* Just like what happens for functions, if we are ordering between
17414 different class template specializations, we may encounter dependent
17415 types in the arguments, and we need our dependency check functions
17416 to behave correctly. */
17417 ++processing_template_decl;
17418 targs = get_class_bindings (TREE_VALUE (pat1),
17419 CLASSTYPE_TI_ARGS (tmpl1),
17420 CLASSTYPE_TI_ARGS (tmpl2));
17424 any_deductions = true;
17427 targs = get_class_bindings (TREE_VALUE (pat2),
17428 CLASSTYPE_TI_ARGS (tmpl2),
17429 CLASSTYPE_TI_ARGS (tmpl1));
17433 any_deductions = true;
17435 --processing_template_decl;
17437 /* In the case of a tie where at least one of the class templates
17438 has a parameter pack at the end, the template with the most
17439 non-packed parameters wins. */
17442 && (template_args_variadic_p (TREE_PURPOSE (pat1))
17443 || template_args_variadic_p (TREE_PURPOSE (pat2))))
17445 tree args1 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat1));
17446 tree args2 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat2));
17447 int len1 = TREE_VEC_LENGTH (args1);
17448 int len2 = TREE_VEC_LENGTH (args2);
17450 /* We don't count the pack expansion at the end. */
17451 if (template_args_variadic_p (TREE_PURPOSE (pat1)))
17453 if (template_args_variadic_p (TREE_PURPOSE (pat2)))
17458 else if (len1 < len2)
17465 /* Return the template arguments that will produce the function signature
17466 DECL from the function template FN, with the explicit template
17467 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
17468 also match. Return NULL_TREE if no satisfactory arguments could be
17472 get_bindings (tree fn, tree decl, tree explicit_args, bool check_rettype)
17474 int ntparms = DECL_NTPARMS (fn);
17475 tree targs = make_tree_vec (ntparms);
17477 tree decl_arg_types;
17479 unsigned int nargs, ix;
17482 /* Substitute the explicit template arguments into the type of DECL.
17483 The call to fn_type_unification will handle substitution into the
17485 decl_type = TREE_TYPE (decl);
17486 if (explicit_args && uses_template_parms (decl_type))
17489 tree converted_args;
17491 if (DECL_TEMPLATE_INFO (decl))
17492 tmpl = DECL_TI_TEMPLATE (decl);
17494 /* We can get here for some invalid specializations. */
17498 = coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
17499 explicit_args, NULL_TREE,
17501 /*require_all_args=*/false,
17502 /*use_default_args=*/false);
17503 if (converted_args == error_mark_node)
17506 decl_type = tsubst (decl_type, converted_args, tf_none, NULL_TREE);
17507 if (decl_type == error_mark_node)
17511 /* Never do unification on the 'this' parameter. */
17512 decl_arg_types = skip_artificial_parms_for (decl,
17513 TYPE_ARG_TYPES (decl_type));
17515 nargs = list_length (decl_arg_types);
17516 args = XALLOCAVEC (tree, nargs);
17517 for (arg = decl_arg_types, ix = 0;
17518 arg != NULL_TREE && arg != void_list_node;
17519 arg = TREE_CHAIN (arg), ++ix)
17520 args[ix] = TREE_VALUE (arg);
17522 if (fn_type_unification (fn, explicit_args, targs,
17524 (check_rettype || DECL_CONV_FN_P (fn)
17525 ? TREE_TYPE (decl_type) : NULL_TREE),
17526 DEDUCE_EXACT, LOOKUP_NORMAL, /*explain_p=*/false))
17532 /* Return the innermost template arguments that, when applied to a
17533 template specialization whose innermost template parameters are
17534 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
17537 For example, suppose we have:
17539 template <class T, class U> struct S {};
17540 template <class T> struct S<T*, int> {};
17542 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
17543 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
17544 int}. The resulting vector will be {double}, indicating that `T'
17545 is bound to `double'. */
17548 get_class_bindings (tree tparms, tree spec_args, tree args)
17550 int i, ntparms = TREE_VEC_LENGTH (tparms);
17552 tree innermost_deduced_args;
17554 innermost_deduced_args = make_tree_vec (ntparms);
17555 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
17557 deduced_args = copy_node (args);
17558 SET_TMPL_ARGS_LEVEL (deduced_args,
17559 TMPL_ARGS_DEPTH (deduced_args),
17560 innermost_deduced_args);
17563 deduced_args = innermost_deduced_args;
17565 if (unify (tparms, deduced_args,
17566 INNERMOST_TEMPLATE_ARGS (spec_args),
17567 INNERMOST_TEMPLATE_ARGS (args),
17568 UNIFY_ALLOW_NONE, /*explain_p=*/false))
17571 for (i = 0; i < ntparms; ++i)
17572 if (! TREE_VEC_ELT (innermost_deduced_args, i))
17575 /* Verify that nondeduced template arguments agree with the type
17576 obtained from argument deduction.
17580 struct A { typedef int X; };
17581 template <class T, class U> struct C {};
17582 template <class T> struct C<T, typename T::X> {};
17584 Then with the instantiation `C<A, int>', we can deduce that
17585 `T' is `A' but unify () does not check whether `typename T::X'
17587 spec_args = tsubst (spec_args, deduced_args, tf_none, NULL_TREE);
17588 if (spec_args == error_mark_node
17589 /* We only need to check the innermost arguments; the other
17590 arguments will always agree. */
17591 || !comp_template_args (INNERMOST_TEMPLATE_ARGS (spec_args),
17592 INNERMOST_TEMPLATE_ARGS (args)))
17595 /* Now that we have bindings for all of the template arguments,
17596 ensure that the arguments deduced for the template template
17597 parameters have compatible template parameter lists. See the use
17598 of template_template_parm_bindings_ok_p in fn_type_unification
17599 for more information. */
17600 if (!template_template_parm_bindings_ok_p (tparms, deduced_args))
17603 return deduced_args;
17606 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
17607 Return the TREE_LIST node with the most specialized template, if
17608 any. If there is no most specialized template, the error_mark_node
17611 Note that this function does not look at, or modify, the
17612 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
17613 returned is one of the elements of INSTANTIATIONS, callers may
17614 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
17615 and retrieve it from the value returned. */
17618 most_specialized_instantiation (tree templates)
17622 ++processing_template_decl;
17625 for (fn = TREE_CHAIN (templates); fn; fn = TREE_CHAIN (fn))
17629 if (get_bindings (TREE_VALUE (champ),
17630 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
17631 NULL_TREE, /*check_ret=*/true))
17634 if (get_bindings (TREE_VALUE (fn),
17635 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
17636 NULL_TREE, /*check_ret=*/true))
17643 /* Equally specialized, move to next function. If there
17644 is no next function, nothing's most specialized. */
17645 fn = TREE_CHAIN (fn);
17653 /* Now verify that champ is better than everything earlier in the
17654 instantiation list. */
17655 for (fn = templates; fn != champ; fn = TREE_CHAIN (fn))
17656 if (get_bindings (TREE_VALUE (champ),
17657 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
17658 NULL_TREE, /*check_ret=*/true)
17659 || !get_bindings (TREE_VALUE (fn),
17660 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
17661 NULL_TREE, /*check_ret=*/true))
17667 processing_template_decl--;
17670 return error_mark_node;
17675 /* If DECL is a specialization of some template, return the most
17676 general such template. Otherwise, returns NULL_TREE.
17678 For example, given:
17680 template <class T> struct S { template <class U> void f(U); };
17682 if TMPL is `template <class U> void S<int>::f(U)' this will return
17683 the full template. This function will not trace past partial
17684 specializations, however. For example, given in addition:
17686 template <class T> struct S<T*> { template <class U> void f(U); };
17688 if TMPL is `template <class U> void S<int*>::f(U)' this will return
17689 `template <class T> template <class U> S<T*>::f(U)'. */
17692 most_general_template (tree decl)
17694 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
17695 an immediate specialization. */
17696 if (TREE_CODE (decl) == FUNCTION_DECL)
17698 if (DECL_TEMPLATE_INFO (decl)) {
17699 decl = DECL_TI_TEMPLATE (decl);
17701 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
17702 template friend. */
17703 if (TREE_CODE (decl) != TEMPLATE_DECL)
17709 /* Look for more and more general templates. */
17710 while (DECL_TEMPLATE_INFO (decl))
17712 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
17713 (See cp-tree.h for details.) */
17714 if (TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
17717 if (CLASS_TYPE_P (TREE_TYPE (decl))
17718 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)))
17721 /* Stop if we run into an explicitly specialized class template. */
17722 if (!DECL_NAMESPACE_SCOPE_P (decl)
17723 && DECL_CONTEXT (decl)
17724 && CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (decl)))
17727 decl = DECL_TI_TEMPLATE (decl);
17733 /* Return the most specialized of the class template partial
17734 specializations of TMPL which can produce TYPE, a specialization of
17735 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
17736 a _TYPE node corresponding to the partial specialization, while the
17737 TREE_PURPOSE is the set of template arguments that must be
17738 substituted into the TREE_TYPE in order to generate TYPE.
17740 If the choice of partial specialization is ambiguous, a diagnostic
17741 is issued, and the error_mark_node is returned. If there are no
17742 partial specializations of TMPL matching TYPE, then NULL_TREE is
17746 most_specialized_class (tree type, tree tmpl, tsubst_flags_t complain)
17748 tree list = NULL_TREE;
17754 tree outer_args = NULL_TREE;
17756 tmpl = most_general_template (tmpl);
17757 args = CLASSTYPE_TI_ARGS (type);
17759 /* For determining which partial specialization to use, only the
17760 innermost args are interesting. */
17761 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
17763 outer_args = strip_innermost_template_args (args, 1);
17764 args = INNERMOST_TEMPLATE_ARGS (args);
17767 for (t = DECL_TEMPLATE_SPECIALIZATIONS (tmpl); t; t = TREE_CHAIN (t))
17769 tree partial_spec_args;
17771 tree parms = TREE_VALUE (t);
17773 partial_spec_args = CLASSTYPE_TI_ARGS (TREE_TYPE (t));
17775 ++processing_template_decl;
17781 /* Discard the outer levels of args, and then substitute in the
17782 template args from the enclosing class. */
17783 partial_spec_args = INNERMOST_TEMPLATE_ARGS (partial_spec_args);
17784 partial_spec_args = tsubst_template_args
17785 (partial_spec_args, outer_args, tf_none, NULL_TREE);
17787 /* PARMS already refers to just the innermost parms, but the
17788 template parms in partial_spec_args had their levels lowered
17789 by tsubst, so we need to do the same for the parm list. We
17790 can't just tsubst the TREE_VEC itself, as tsubst wants to
17791 treat a TREE_VEC as an argument vector. */
17792 parms = copy_node (parms);
17793 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
17794 TREE_VEC_ELT (parms, i) =
17795 tsubst (TREE_VEC_ELT (parms, i), outer_args, tf_none, NULL_TREE);
17799 partial_spec_args =
17800 coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
17801 add_to_template_args (outer_args,
17802 partial_spec_args),
17804 /*require_all_args=*/true,
17805 /*use_default_args=*/true);
17807 --processing_template_decl;
17809 if (partial_spec_args == error_mark_node)
17810 return error_mark_node;
17812 spec_args = get_class_bindings (parms,
17818 spec_args = add_to_template_args (outer_args, spec_args);
17819 list = tree_cons (spec_args, TREE_VALUE (t), list);
17820 TREE_TYPE (list) = TREE_TYPE (t);
17827 ambiguous_p = false;
17830 t = TREE_CHAIN (t);
17831 for (; t; t = TREE_CHAIN (t))
17833 fate = more_specialized_class (champ, t);
17840 t = TREE_CHAIN (t);
17843 ambiguous_p = true;
17852 for (t = list; t && t != champ; t = TREE_CHAIN (t))
17854 fate = more_specialized_class (champ, t);
17857 ambiguous_p = true;
17865 char *spaces = NULL;
17866 if (!(complain & tf_error))
17867 return error_mark_node;
17868 error ("ambiguous class template instantiation for %q#T", type);
17869 str = ngettext ("candidate is:", "candidates are:", list_length (list));
17870 for (t = list; t; t = TREE_CHAIN (t))
17872 error ("%s %+#T", spaces ? spaces : str, TREE_TYPE (t));
17873 spaces = spaces ? spaces : get_spaces (str);
17876 return error_mark_node;
17882 /* Explicitly instantiate DECL. */
17885 do_decl_instantiation (tree decl, tree storage)
17887 tree result = NULL_TREE;
17890 if (!decl || decl == error_mark_node)
17891 /* An error occurred, for which grokdeclarator has already issued
17892 an appropriate message. */
17894 else if (! DECL_LANG_SPECIFIC (decl))
17896 error ("explicit instantiation of non-template %q#D", decl);
17899 else if (TREE_CODE (decl) == VAR_DECL)
17901 /* There is an asymmetry here in the way VAR_DECLs and
17902 FUNCTION_DECLs are handled by grokdeclarator. In the case of
17903 the latter, the DECL we get back will be marked as a
17904 template instantiation, and the appropriate
17905 DECL_TEMPLATE_INFO will be set up. This does not happen for
17906 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
17907 should handle VAR_DECLs as it currently handles
17909 if (!DECL_CLASS_SCOPE_P (decl))
17911 error ("%qD is not a static data member of a class template", decl);
17914 result = lookup_field (DECL_CONTEXT (decl), DECL_NAME (decl), 0, false);
17915 if (!result || TREE_CODE (result) != VAR_DECL)
17917 error ("no matching template for %qD found", decl);
17920 if (!same_type_p (TREE_TYPE (result), TREE_TYPE (decl)))
17922 error ("type %qT for explicit instantiation %qD does not match "
17923 "declared type %qT", TREE_TYPE (result), decl,
17928 else if (TREE_CODE (decl) != FUNCTION_DECL)
17930 error ("explicit instantiation of %q#D", decl);
17936 /* Check for various error cases. Note that if the explicit
17937 instantiation is valid the RESULT will currently be marked as an
17938 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
17939 until we get here. */
17941 if (DECL_TEMPLATE_SPECIALIZATION (result))
17943 /* DR 259 [temp.spec].
17945 Both an explicit instantiation and a declaration of an explicit
17946 specialization shall not appear in a program unless the explicit
17947 instantiation follows a declaration of the explicit specialization.
17949 For a given set of template parameters, if an explicit
17950 instantiation of a template appears after a declaration of an
17951 explicit specialization for that template, the explicit
17952 instantiation has no effect. */
17955 else if (DECL_EXPLICIT_INSTANTIATION (result))
17959 No program shall explicitly instantiate any template more
17962 We check DECL_NOT_REALLY_EXTERN so as not to complain when
17963 the first instantiation was `extern' and the second is not,
17964 and EXTERN_P for the opposite case. */
17965 if (DECL_NOT_REALLY_EXTERN (result) && !extern_p)
17966 permerror (input_location, "duplicate explicit instantiation of %q#D", result);
17967 /* If an "extern" explicit instantiation follows an ordinary
17968 explicit instantiation, the template is instantiated. */
17972 else if (!DECL_IMPLICIT_INSTANTIATION (result))
17974 error ("no matching template for %qD found", result);
17977 else if (!DECL_TEMPLATE_INFO (result))
17979 permerror (input_location, "explicit instantiation of non-template %q#D", result);
17983 if (storage == NULL_TREE)
17985 else if (storage == ridpointers[(int) RID_EXTERN])
17987 if (!in_system_header && (cxx_dialect == cxx98))
17988 pedwarn (input_location, OPT_pedantic,
17989 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
17994 error ("storage class %qD applied to template instantiation", storage);
17996 check_explicit_instantiation_namespace (result);
17997 mark_decl_instantiated (result, extern_p);
17999 instantiate_decl (result, /*defer_ok=*/1,
18000 /*expl_inst_class_mem_p=*/false);
18004 mark_class_instantiated (tree t, int extern_p)
18006 SET_CLASSTYPE_EXPLICIT_INSTANTIATION (t);
18007 SET_CLASSTYPE_INTERFACE_KNOWN (t);
18008 CLASSTYPE_INTERFACE_ONLY (t) = extern_p;
18009 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (t)) = extern_p;
18012 CLASSTYPE_DEBUG_REQUESTED (t) = 1;
18013 rest_of_type_compilation (t, 1);
18017 /* Called from do_type_instantiation through binding_table_foreach to
18018 do recursive instantiation for the type bound in ENTRY. */
18020 bt_instantiate_type_proc (binding_entry entry, void *data)
18022 tree storage = *(tree *) data;
18024 if (MAYBE_CLASS_TYPE_P (entry->type)
18025 && !uses_template_parms (CLASSTYPE_TI_ARGS (entry->type)))
18026 do_type_instantiation (TYPE_MAIN_DECL (entry->type), storage, 0);
18029 /* Called from do_type_instantiation to instantiate a member
18030 (a member function or a static member variable) of an
18031 explicitly instantiated class template. */
18033 instantiate_class_member (tree decl, int extern_p)
18035 mark_decl_instantiated (decl, extern_p);
18037 instantiate_decl (decl, /*defer_ok=*/1,
18038 /*expl_inst_class_mem_p=*/true);
18041 /* Perform an explicit instantiation of template class T. STORAGE, if
18042 non-null, is the RID for extern, inline or static. COMPLAIN is
18043 nonzero if this is called from the parser, zero if called recursively,
18044 since the standard is unclear (as detailed below). */
18047 do_type_instantiation (tree t, tree storage, tsubst_flags_t complain)
18052 int previous_instantiation_extern_p = 0;
18054 if (TREE_CODE (t) == TYPE_DECL)
18057 if (! CLASS_TYPE_P (t) || ! CLASSTYPE_TEMPLATE_INFO (t))
18060 (TYPE_TEMPLATE_INFO (t)) ? TYPE_TI_TEMPLATE (t) : NULL;
18062 error ("explicit instantiation of non-class template %qD", tmpl);
18064 error ("explicit instantiation of non-template type %qT", t);
18070 if (!COMPLETE_TYPE_P (t))
18072 if (complain & tf_error)
18073 error ("explicit instantiation of %q#T before definition of template",
18078 if (storage != NULL_TREE)
18080 if (!in_system_header)
18082 if (storage == ridpointers[(int) RID_EXTERN])
18084 if (cxx_dialect == cxx98)
18085 pedwarn (input_location, OPT_pedantic,
18086 "ISO C++ 1998 forbids the use of %<extern%> on "
18087 "explicit instantiations");
18090 pedwarn (input_location, OPT_pedantic,
18091 "ISO C++ forbids the use of %qE"
18092 " on explicit instantiations", storage);
18095 if (storage == ridpointers[(int) RID_INLINE])
18097 else if (storage == ridpointers[(int) RID_EXTERN])
18099 else if (storage == ridpointers[(int) RID_STATIC])
18103 error ("storage class %qD applied to template instantiation",
18109 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (t))
18111 /* DR 259 [temp.spec].
18113 Both an explicit instantiation and a declaration of an explicit
18114 specialization shall not appear in a program unless the explicit
18115 instantiation follows a declaration of the explicit specialization.
18117 For a given set of template parameters, if an explicit
18118 instantiation of a template appears after a declaration of an
18119 explicit specialization for that template, the explicit
18120 instantiation has no effect. */
18123 else if (CLASSTYPE_EXPLICIT_INSTANTIATION (t))
18127 No program shall explicitly instantiate any template more
18130 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
18131 instantiation was `extern'. If EXTERN_P then the second is.
18132 These cases are OK. */
18133 previous_instantiation_extern_p = CLASSTYPE_INTERFACE_ONLY (t);
18135 if (!previous_instantiation_extern_p && !extern_p
18136 && (complain & tf_error))
18137 permerror (input_location, "duplicate explicit instantiation of %q#T", t);
18139 /* If we've already instantiated the template, just return now. */
18140 if (!CLASSTYPE_INTERFACE_ONLY (t))
18144 check_explicit_instantiation_namespace (TYPE_NAME (t));
18145 mark_class_instantiated (t, extern_p);
18153 /* In contrast to implicit instantiation, where only the
18154 declarations, and not the definitions, of members are
18155 instantiated, we have here:
18159 The explicit instantiation of a class template specialization
18160 implies the instantiation of all of its members not
18161 previously explicitly specialized in the translation unit
18162 containing the explicit instantiation.
18164 Of course, we can't instantiate member template classes, since
18165 we don't have any arguments for them. Note that the standard
18166 is unclear on whether the instantiation of the members are
18167 *explicit* instantiations or not. However, the most natural
18168 interpretation is that it should be an explicit instantiation. */
18171 for (tmp = TYPE_METHODS (t); tmp; tmp = DECL_CHAIN (tmp))
18172 if (TREE_CODE (tmp) == FUNCTION_DECL
18173 && DECL_TEMPLATE_INSTANTIATION (tmp))
18174 instantiate_class_member (tmp, extern_p);
18176 for (tmp = TYPE_FIELDS (t); tmp; tmp = DECL_CHAIN (tmp))
18177 if (TREE_CODE (tmp) == VAR_DECL && DECL_TEMPLATE_INSTANTIATION (tmp))
18178 instantiate_class_member (tmp, extern_p);
18180 if (CLASSTYPE_NESTED_UTDS (t))
18181 binding_table_foreach (CLASSTYPE_NESTED_UTDS (t),
18182 bt_instantiate_type_proc, &storage);
18186 /* Given a function DECL, which is a specialization of TMPL, modify
18187 DECL to be a re-instantiation of TMPL with the same template
18188 arguments. TMPL should be the template into which tsubst'ing
18189 should occur for DECL, not the most general template.
18191 One reason for doing this is a scenario like this:
18194 void f(const T&, int i);
18196 void g() { f(3, 7); }
18199 void f(const T& t, const int i) { }
18201 Note that when the template is first instantiated, with
18202 instantiate_template, the resulting DECL will have no name for the
18203 first parameter, and the wrong type for the second. So, when we go
18204 to instantiate the DECL, we regenerate it. */
18207 regenerate_decl_from_template (tree decl, tree tmpl)
18209 /* The arguments used to instantiate DECL, from the most general
18214 args = DECL_TI_ARGS (decl);
18215 code_pattern = DECL_TEMPLATE_RESULT (tmpl);
18217 /* Make sure that we can see identifiers, and compute access
18219 push_access_scope (decl);
18221 if (TREE_CODE (decl) == FUNCTION_DECL)
18229 args_depth = TMPL_ARGS_DEPTH (args);
18230 parms_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
18231 if (args_depth > parms_depth)
18232 args = get_innermost_template_args (args, parms_depth);
18234 specs = tsubst_exception_specification (TREE_TYPE (code_pattern),
18235 args, tf_error, NULL_TREE,
18236 /*defer_ok*/false);
18237 if (specs && specs != error_mark_node)
18238 TREE_TYPE (decl) = build_exception_variant (TREE_TYPE (decl),
18241 /* Merge parameter declarations. */
18242 decl_parm = skip_artificial_parms_for (decl,
18243 DECL_ARGUMENTS (decl));
18245 = skip_artificial_parms_for (code_pattern,
18246 DECL_ARGUMENTS (code_pattern));
18247 while (decl_parm && !FUNCTION_PARAMETER_PACK_P (pattern_parm))
18252 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
18253 DECL_NAME (decl_parm) = DECL_NAME (pattern_parm);
18254 parm_type = tsubst (TREE_TYPE (pattern_parm), args, tf_error,
18256 parm_type = type_decays_to (parm_type);
18257 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
18258 TREE_TYPE (decl_parm) = parm_type;
18259 attributes = DECL_ATTRIBUTES (pattern_parm);
18260 if (DECL_ATTRIBUTES (decl_parm) != attributes)
18262 DECL_ATTRIBUTES (decl_parm) = attributes;
18263 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
18265 decl_parm = DECL_CHAIN (decl_parm);
18266 pattern_parm = DECL_CHAIN (pattern_parm);
18268 /* Merge any parameters that match with the function parameter
18270 if (pattern_parm && FUNCTION_PARAMETER_PACK_P (pattern_parm))
18273 tree expanded_types;
18274 /* Expand the TYPE_PACK_EXPANSION that provides the types for
18275 the parameters in this function parameter pack. */
18276 expanded_types = tsubst_pack_expansion (TREE_TYPE (pattern_parm),
18277 args, tf_error, NULL_TREE);
18278 len = TREE_VEC_LENGTH (expanded_types);
18279 for (i = 0; i < len; i++)
18284 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
18285 /* Rename the parameter to include the index. */
18286 DECL_NAME (decl_parm) =
18287 make_ith_pack_parameter_name (DECL_NAME (pattern_parm), i);
18288 parm_type = TREE_VEC_ELT (expanded_types, i);
18289 parm_type = type_decays_to (parm_type);
18290 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
18291 TREE_TYPE (decl_parm) = parm_type;
18292 attributes = DECL_ATTRIBUTES (pattern_parm);
18293 if (DECL_ATTRIBUTES (decl_parm) != attributes)
18295 DECL_ATTRIBUTES (decl_parm) = attributes;
18296 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
18298 decl_parm = DECL_CHAIN (decl_parm);
18301 /* Merge additional specifiers from the CODE_PATTERN. */
18302 if (DECL_DECLARED_INLINE_P (code_pattern)
18303 && !DECL_DECLARED_INLINE_P (decl))
18304 DECL_DECLARED_INLINE_P (decl) = 1;
18306 else if (TREE_CODE (decl) == VAR_DECL)
18308 DECL_INITIAL (decl) =
18309 tsubst_expr (DECL_INITIAL (code_pattern), args,
18310 tf_error, DECL_TI_TEMPLATE (decl),
18311 /*integral_constant_expression_p=*/false);
18312 if (VAR_HAD_UNKNOWN_BOUND (decl))
18313 TREE_TYPE (decl) = tsubst (TREE_TYPE (code_pattern), args,
18314 tf_error, DECL_TI_TEMPLATE (decl));
18317 gcc_unreachable ();
18319 pop_access_scope (decl);
18322 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
18323 substituted to get DECL. */
18326 template_for_substitution (tree decl)
18328 tree tmpl = DECL_TI_TEMPLATE (decl);
18330 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
18331 for the instantiation. This is not always the most general
18332 template. Consider, for example:
18335 struct S { template <class U> void f();
18336 template <> void f<int>(); };
18338 and an instantiation of S<double>::f<int>. We want TD to be the
18339 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
18340 while (/* An instantiation cannot have a definition, so we need a
18341 more general template. */
18342 DECL_TEMPLATE_INSTANTIATION (tmpl)
18343 /* We must also deal with friend templates. Given:
18345 template <class T> struct S {
18346 template <class U> friend void f() {};
18349 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
18350 so far as the language is concerned, but that's still
18351 where we get the pattern for the instantiation from. On
18352 other hand, if the definition comes outside the class, say:
18354 template <class T> struct S {
18355 template <class U> friend void f();
18357 template <class U> friend void f() {}
18359 we don't need to look any further. That's what the check for
18360 DECL_INITIAL is for. */
18361 || (TREE_CODE (decl) == FUNCTION_DECL
18362 && DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION (tmpl)
18363 && !DECL_INITIAL (DECL_TEMPLATE_RESULT (tmpl))))
18365 /* The present template, TD, should not be a definition. If it
18366 were a definition, we should be using it! Note that we
18367 cannot restructure the loop to just keep going until we find
18368 a template with a definition, since that might go too far if
18369 a specialization was declared, but not defined. */
18370 gcc_assert (TREE_CODE (decl) != VAR_DECL
18371 || DECL_IN_AGGR_P (DECL_TEMPLATE_RESULT (tmpl)));
18373 /* Fetch the more general template. */
18374 tmpl = DECL_TI_TEMPLATE (tmpl);
18380 /* Returns true if we need to instantiate this template instance even if we
18381 know we aren't going to emit it.. */
18384 always_instantiate_p (tree decl)
18386 /* We always instantiate inline functions so that we can inline them. An
18387 explicit instantiation declaration prohibits implicit instantiation of
18388 non-inline functions. With high levels of optimization, we would
18389 normally inline non-inline functions -- but we're not allowed to do
18390 that for "extern template" functions. Therefore, we check
18391 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
18392 return ((TREE_CODE (decl) == FUNCTION_DECL
18393 && DECL_DECLARED_INLINE_P (decl))
18394 /* And we need to instantiate static data members so that
18395 their initializers are available in integral constant
18397 || (TREE_CODE (decl) == VAR_DECL
18398 && decl_maybe_constant_var_p (decl)));
18401 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
18402 instantiate it now, modifying TREE_TYPE (fn). */
18405 maybe_instantiate_noexcept (tree fn)
18407 tree fntype, spec, noex, clone;
18409 if (DECL_CLONED_FUNCTION_P (fn))
18410 fn = DECL_CLONED_FUNCTION (fn);
18411 fntype = TREE_TYPE (fn);
18412 spec = TYPE_RAISES_EXCEPTIONS (fntype);
18414 if (!DEFERRED_NOEXCEPT_SPEC_P (spec))
18417 noex = TREE_PURPOSE (spec);
18419 if (TREE_CODE (noex) == DEFERRED_NOEXCEPT)
18421 if (push_tinst_level (fn))
18423 push_access_scope (fn);
18424 input_location = DECL_SOURCE_LOCATION (fn);
18425 noex = tsubst_copy_and_build (DEFERRED_NOEXCEPT_PATTERN (noex),
18426 DEFERRED_NOEXCEPT_ARGS (noex),
18427 tf_warning_or_error, fn,
18428 /*function_p=*/false,
18429 /*integral_constant_expression_p=*/true);
18430 pop_access_scope (fn);
18431 pop_tinst_level ();
18432 spec = build_noexcept_spec (noex, tf_warning_or_error);
18433 if (spec == error_mark_node)
18434 spec = noexcept_false_spec;
18437 spec = noexcept_false_spec;
18441 /* This is an implicitly declared function, so NOEX is a list of
18442 other functions to evaluate and merge. */
18444 spec = noexcept_true_spec;
18445 for (elt = noex; elt; elt = OVL_NEXT (elt))
18447 tree fn = OVL_CURRENT (elt);
18449 maybe_instantiate_noexcept (fn);
18450 subspec = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (fn));
18451 spec = merge_exception_specifiers (spec, subspec, NULL_TREE);
18455 TREE_TYPE (fn) = build_exception_variant (fntype, spec);
18457 FOR_EACH_CLONE (clone, fn)
18459 if (TREE_TYPE (clone) == fntype)
18460 TREE_TYPE (clone) = TREE_TYPE (fn);
18462 TREE_TYPE (clone) = build_exception_variant (TREE_TYPE (clone), spec);
18466 /* Produce the definition of D, a _DECL generated from a template. If
18467 DEFER_OK is nonzero, then we don't have to actually do the
18468 instantiation now; we just have to do it sometime. Normally it is
18469 an error if this is an explicit instantiation but D is undefined.
18470 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
18471 explicitly instantiated class template. */
18474 instantiate_decl (tree d, int defer_ok,
18475 bool expl_inst_class_mem_p)
18477 tree tmpl = DECL_TI_TEMPLATE (d);
18484 bool pattern_defined;
18485 location_t saved_loc = input_location;
18490 /* This function should only be used to instantiate templates for
18491 functions and static member variables. */
18492 gcc_assert (TREE_CODE (d) == FUNCTION_DECL
18493 || TREE_CODE (d) == VAR_DECL);
18495 /* Variables are never deferred; if instantiation is required, they
18496 are instantiated right away. That allows for better code in the
18497 case that an expression refers to the value of the variable --
18498 if the variable has a constant value the referring expression can
18499 take advantage of that fact. */
18500 if (TREE_CODE (d) == VAR_DECL
18501 || DECL_DECLARED_CONSTEXPR_P (d))
18504 /* Don't instantiate cloned functions. Instead, instantiate the
18505 functions they cloned. */
18506 if (TREE_CODE (d) == FUNCTION_DECL && DECL_CLONED_FUNCTION_P (d))
18507 d = DECL_CLONED_FUNCTION (d);
18509 if (DECL_TEMPLATE_INSTANTIATED (d)
18510 || (TREE_CODE (d) == FUNCTION_DECL
18511 && DECL_DEFAULTED_FN (d) && DECL_INITIAL (d))
18512 || DECL_TEMPLATE_SPECIALIZATION (d))
18513 /* D has already been instantiated or explicitly specialized, so
18514 there's nothing for us to do here.
18516 It might seem reasonable to check whether or not D is an explicit
18517 instantiation, and, if so, stop here. But when an explicit
18518 instantiation is deferred until the end of the compilation,
18519 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
18520 the instantiation. */
18523 /* Check to see whether we know that this template will be
18524 instantiated in some other file, as with "extern template"
18526 external_p = (DECL_INTERFACE_KNOWN (d) && DECL_REALLY_EXTERN (d));
18528 /* In general, we do not instantiate such templates. */
18529 if (external_p && !always_instantiate_p (d))
18532 gen_tmpl = most_general_template (tmpl);
18533 gen_args = DECL_TI_ARGS (d);
18535 if (tmpl != gen_tmpl)
18536 /* We should already have the extra args. */
18537 gcc_assert (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (gen_tmpl))
18538 == TMPL_ARGS_DEPTH (gen_args));
18539 /* And what's in the hash table should match D. */
18540 gcc_assert ((spec = retrieve_specialization (gen_tmpl, gen_args, 0)) == d
18541 || spec == NULL_TREE);
18543 /* This needs to happen before any tsubsting. */
18544 if (! push_tinst_level (d))
18547 timevar_push (TV_TEMPLATE_INST);
18549 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
18550 for the instantiation. */
18551 td = template_for_substitution (d);
18552 code_pattern = DECL_TEMPLATE_RESULT (td);
18554 /* We should never be trying to instantiate a member of a class
18555 template or partial specialization. */
18556 gcc_assert (d != code_pattern);
18558 if ((DECL_NAMESPACE_SCOPE_P (d) && !DECL_INITIALIZED_IN_CLASS_P (d))
18559 || DECL_TEMPLATE_SPECIALIZATION (td))
18560 /* In the case of a friend template whose definition is provided
18561 outside the class, we may have too many arguments. Drop the
18562 ones we don't need. The same is true for specializations. */
18563 args = get_innermost_template_args
18564 (gen_args, TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (td)));
18568 if (TREE_CODE (d) == FUNCTION_DECL)
18569 pattern_defined = (DECL_SAVED_TREE (code_pattern) != NULL_TREE
18570 || DECL_DEFAULTED_OUTSIDE_CLASS_P (code_pattern));
18572 pattern_defined = ! DECL_IN_AGGR_P (code_pattern);
18574 /* We may be in the middle of deferred access check. Disable it now. */
18575 push_deferring_access_checks (dk_no_deferred);
18577 /* Unless an explicit instantiation directive has already determined
18578 the linkage of D, remember that a definition is available for
18580 if (pattern_defined
18581 && !DECL_INTERFACE_KNOWN (d)
18582 && !DECL_NOT_REALLY_EXTERN (d))
18583 mark_definable (d);
18585 DECL_SOURCE_LOCATION (td) = DECL_SOURCE_LOCATION (code_pattern);
18586 DECL_SOURCE_LOCATION (d) = DECL_SOURCE_LOCATION (code_pattern);
18587 input_location = DECL_SOURCE_LOCATION (d);
18589 /* If D is a member of an explicitly instantiated class template,
18590 and no definition is available, treat it like an implicit
18592 if (!pattern_defined && expl_inst_class_mem_p
18593 && DECL_EXPLICIT_INSTANTIATION (d))
18595 /* Leave linkage flags alone on instantiations with anonymous
18597 if (TREE_PUBLIC (d))
18599 DECL_NOT_REALLY_EXTERN (d) = 0;
18600 DECL_INTERFACE_KNOWN (d) = 0;
18602 SET_DECL_IMPLICIT_INSTANTIATION (d);
18605 if (TREE_CODE (d) == FUNCTION_DECL)
18606 maybe_instantiate_noexcept (d);
18608 /* Recheck the substitutions to obtain any warning messages
18609 about ignoring cv qualifiers. Don't do this for artificial decls,
18610 as it breaks the context-sensitive substitution for lambda op(). */
18611 if (!defer_ok && !DECL_ARTIFICIAL (d))
18613 tree gen = DECL_TEMPLATE_RESULT (gen_tmpl);
18614 tree type = TREE_TYPE (gen);
18616 /* Make sure that we can see identifiers, and compute access
18617 correctly. D is already the target FUNCTION_DECL with the
18619 push_access_scope (d);
18621 if (TREE_CODE (gen) == FUNCTION_DECL)
18623 tsubst (DECL_ARGUMENTS (gen), gen_args, tf_warning_or_error, d);
18624 tsubst_exception_specification (type, gen_args, tf_warning_or_error,
18625 d, /*defer_ok*/true);
18626 /* Don't simply tsubst the function type, as that will give
18627 duplicate warnings about poor parameter qualifications.
18628 The function arguments are the same as the decl_arguments
18629 without the top level cv qualifiers. */
18630 type = TREE_TYPE (type);
18632 tsubst (type, gen_args, tf_warning_or_error, d);
18634 pop_access_scope (d);
18637 /* Defer all other templates, unless we have been explicitly
18638 forbidden from doing so. */
18639 if (/* If there is no definition, we cannot instantiate the
18642 /* If it's OK to postpone instantiation, do so. */
18644 /* If this is a static data member that will be defined
18645 elsewhere, we don't want to instantiate the entire data
18646 member, but we do want to instantiate the initializer so that
18647 we can substitute that elsewhere. */
18648 || (external_p && TREE_CODE (d) == VAR_DECL))
18650 /* The definition of the static data member is now required so
18651 we must substitute the initializer. */
18652 if (TREE_CODE (d) == VAR_DECL
18653 && !DECL_INITIAL (d)
18654 && DECL_INITIAL (code_pattern))
18658 bool const_init = false;
18660 ns = decl_namespace_context (d);
18661 push_nested_namespace (ns);
18662 push_nested_class (DECL_CONTEXT (d));
18663 init = tsubst_expr (DECL_INITIAL (code_pattern),
18665 tf_warning_or_error, NULL_TREE,
18666 /*integral_constant_expression_p=*/false);
18667 /* Make sure the initializer is still constant, in case of
18668 circular dependency (template/instantiate6.C). */
18670 = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (code_pattern);
18671 cp_finish_decl (d, init, /*init_const_expr_p=*/const_init,
18672 /*asmspec_tree=*/NULL_TREE,
18673 LOOKUP_ONLYCONVERTING);
18674 pop_nested_class ();
18675 pop_nested_namespace (ns);
18678 /* We restore the source position here because it's used by
18679 add_pending_template. */
18680 input_location = saved_loc;
18682 if (at_eof && !pattern_defined
18683 && DECL_EXPLICIT_INSTANTIATION (d)
18684 && DECL_NOT_REALLY_EXTERN (d))
18687 The definition of a non-exported function template, a
18688 non-exported member function template, or a non-exported
18689 member function or static data member of a class template
18690 shall be present in every translation unit in which it is
18691 explicitly instantiated. */
18692 permerror (input_location, "explicit instantiation of %qD "
18693 "but no definition available", d);
18695 /* If we're in unevaluated context, we just wanted to get the
18696 constant value; this isn't an odr use, so don't queue
18697 a full instantiation. */
18698 if (cp_unevaluated_operand != 0)
18700 /* ??? Historically, we have instantiated inline functions, even
18701 when marked as "extern template". */
18702 if (!(external_p && TREE_CODE (d) == VAR_DECL))
18703 add_pending_template (d);
18706 /* Tell the repository that D is available in this translation unit
18707 -- and see if it is supposed to be instantiated here. */
18708 if (TREE_PUBLIC (d) && !DECL_REALLY_EXTERN (d) && !repo_emit_p (d))
18710 /* In a PCH file, despite the fact that the repository hasn't
18711 requested instantiation in the PCH it is still possible that
18712 an instantiation will be required in a file that includes the
18715 add_pending_template (d);
18716 /* Instantiate inline functions so that the inliner can do its
18717 job, even though we'll not be emitting a copy of this
18719 if (!(TREE_CODE (d) == FUNCTION_DECL && possibly_inlined_p (d)))
18723 fn_context = decl_function_context (d);
18724 nested = (current_function_decl != NULL_TREE);
18726 push_to_top_level ();
18728 push_function_context ();
18730 /* Mark D as instantiated so that recursive calls to
18731 instantiate_decl do not try to instantiate it again. */
18732 DECL_TEMPLATE_INSTANTIATED (d) = 1;
18734 /* Regenerate the declaration in case the template has been modified
18735 by a subsequent redeclaration. */
18736 regenerate_decl_from_template (d, td);
18738 /* We already set the file and line above. Reset them now in case
18739 they changed as a result of calling regenerate_decl_from_template. */
18740 input_location = DECL_SOURCE_LOCATION (d);
18742 if (TREE_CODE (d) == VAR_DECL)
18745 bool const_init = false;
18747 /* Clear out DECL_RTL; whatever was there before may not be right
18748 since we've reset the type of the declaration. */
18749 SET_DECL_RTL (d, NULL);
18750 DECL_IN_AGGR_P (d) = 0;
18752 /* The initializer is placed in DECL_INITIAL by
18753 regenerate_decl_from_template so we don't need to
18754 push/pop_access_scope again here. Pull it out so that
18755 cp_finish_decl can process it. */
18756 init = DECL_INITIAL (d);
18757 DECL_INITIAL (d) = NULL_TREE;
18758 DECL_INITIALIZED_P (d) = 0;
18760 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
18761 initializer. That function will defer actual emission until
18762 we have a chance to determine linkage. */
18763 DECL_EXTERNAL (d) = 0;
18765 /* Enter the scope of D so that access-checking works correctly. */
18766 push_nested_class (DECL_CONTEXT (d));
18767 const_init = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (code_pattern);
18768 cp_finish_decl (d, init, const_init, NULL_TREE, 0);
18769 pop_nested_class ();
18771 else if (TREE_CODE (d) == FUNCTION_DECL && DECL_DEFAULTED_FN (code_pattern))
18772 synthesize_method (d);
18773 else if (TREE_CODE (d) == FUNCTION_DECL)
18775 htab_t saved_local_specializations;
18780 /* Save away the current list, in case we are instantiating one
18781 template from within the body of another. */
18782 saved_local_specializations = local_specializations;
18784 /* Set up the list of local specializations. */
18785 local_specializations = htab_create (37,
18786 hash_local_specialization,
18787 eq_local_specializations,
18790 /* Set up context. */
18791 start_preparsed_function (d, NULL_TREE, SF_PRE_PARSED);
18793 /* Create substitution entries for the parameters. */
18794 subst_decl = DECL_TEMPLATE_RESULT (template_for_substitution (d));
18795 tmpl_parm = DECL_ARGUMENTS (subst_decl);
18796 spec_parm = DECL_ARGUMENTS (d);
18797 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (d))
18799 register_local_specialization (spec_parm, tmpl_parm);
18800 spec_parm = skip_artificial_parms_for (d, spec_parm);
18801 tmpl_parm = skip_artificial_parms_for (subst_decl, tmpl_parm);
18803 for (; tmpl_parm; tmpl_parm = DECL_CHAIN (tmpl_parm))
18805 if (!FUNCTION_PARAMETER_PACK_P (tmpl_parm))
18807 register_local_specialization (spec_parm, tmpl_parm);
18808 spec_parm = DECL_CHAIN (spec_parm);
18812 /* Register the (value) argument pack as a specialization of
18813 TMPL_PARM, then move on. */
18814 tree argpack = extract_fnparm_pack (tmpl_parm, &spec_parm);
18815 register_local_specialization (argpack, tmpl_parm);
18818 gcc_assert (!spec_parm);
18820 /* Substitute into the body of the function. */
18821 tsubst_expr (DECL_SAVED_TREE (code_pattern), args,
18822 tf_warning_or_error, tmpl,
18823 /*integral_constant_expression_p=*/false);
18825 /* Set the current input_location to the end of the function
18826 so that finish_function knows where we are. */
18827 input_location = DECL_STRUCT_FUNCTION (code_pattern)->function_end_locus;
18829 /* We don't need the local specializations any more. */
18830 htab_delete (local_specializations);
18831 local_specializations = saved_local_specializations;
18833 /* Finish the function. */
18834 d = finish_function (0);
18835 expand_or_defer_fn (d);
18838 /* We're not deferring instantiation any more. */
18839 TI_PENDING_TEMPLATE_FLAG (DECL_TEMPLATE_INFO (d)) = 0;
18842 pop_from_top_level ();
18844 pop_function_context ();
18847 input_location = saved_loc;
18848 pop_deferring_access_checks ();
18849 pop_tinst_level ();
18851 timevar_pop (TV_TEMPLATE_INST);
18856 /* Run through the list of templates that we wish we could
18857 instantiate, and instantiate any we can. RETRIES is the
18858 number of times we retry pending template instantiation. */
18861 instantiate_pending_templates (int retries)
18864 location_t saved_loc = input_location;
18866 /* Instantiating templates may trigger vtable generation. This in turn
18867 may require further template instantiations. We place a limit here
18868 to avoid infinite loop. */
18869 if (pending_templates && retries >= max_tinst_depth)
18871 tree decl = pending_templates->tinst->decl;
18873 error ("template instantiation depth exceeds maximum of %d"
18874 " instantiating %q+D, possibly from virtual table generation"
18875 " (use -ftemplate-depth= to increase the maximum)",
18876 max_tinst_depth, decl);
18877 if (TREE_CODE (decl) == FUNCTION_DECL)
18878 /* Pretend that we defined it. */
18879 DECL_INITIAL (decl) = error_mark_node;
18885 struct pending_template **t = &pending_templates;
18886 struct pending_template *last = NULL;
18890 tree instantiation = reopen_tinst_level ((*t)->tinst);
18891 bool complete = false;
18893 if (TYPE_P (instantiation))
18897 if (!COMPLETE_TYPE_P (instantiation))
18899 instantiate_class_template (instantiation);
18900 if (CLASSTYPE_TEMPLATE_INSTANTIATION (instantiation))
18901 for (fn = TYPE_METHODS (instantiation);
18903 fn = TREE_CHAIN (fn))
18904 if (! DECL_ARTIFICIAL (fn))
18905 instantiate_decl (fn,
18907 /*expl_inst_class_mem_p=*/false);
18908 if (COMPLETE_TYPE_P (instantiation))
18912 complete = COMPLETE_TYPE_P (instantiation);
18916 if (!DECL_TEMPLATE_SPECIALIZATION (instantiation)
18917 && !DECL_TEMPLATE_INSTANTIATED (instantiation))
18920 = instantiate_decl (instantiation,
18922 /*expl_inst_class_mem_p=*/false);
18923 if (DECL_TEMPLATE_INSTANTIATED (instantiation))
18927 complete = (DECL_TEMPLATE_SPECIALIZATION (instantiation)
18928 || DECL_TEMPLATE_INSTANTIATED (instantiation));
18932 /* If INSTANTIATION has been instantiated, then we don't
18933 need to consider it again in the future. */
18941 current_tinst_level = NULL;
18943 last_pending_template = last;
18945 while (reconsider);
18947 input_location = saved_loc;
18950 /* Substitute ARGVEC into T, which is a list of initializers for
18951 either base class or a non-static data member. The TREE_PURPOSEs
18952 are DECLs, and the TREE_VALUEs are the initializer values. Used by
18953 instantiate_decl. */
18956 tsubst_initializer_list (tree t, tree argvec)
18958 tree inits = NULL_TREE;
18960 for (; t; t = TREE_CHAIN (t))
18964 tree expanded_bases = NULL_TREE;
18965 tree expanded_arguments = NULL_TREE;
18968 if (TREE_CODE (TREE_PURPOSE (t)) == TYPE_PACK_EXPANSION)
18973 /* Expand the base class expansion type into separate base
18975 expanded_bases = tsubst_pack_expansion (TREE_PURPOSE (t), argvec,
18976 tf_warning_or_error,
18978 if (expanded_bases == error_mark_node)
18981 /* We'll be building separate TREE_LISTs of arguments for
18983 len = TREE_VEC_LENGTH (expanded_bases);
18984 expanded_arguments = make_tree_vec (len);
18985 for (i = 0; i < len; i++)
18986 TREE_VEC_ELT (expanded_arguments, i) = NULL_TREE;
18988 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
18989 expand each argument in the TREE_VALUE of t. */
18990 expr = make_node (EXPR_PACK_EXPANSION);
18991 PACK_EXPANSION_LOCAL_P (expr) = true;
18992 PACK_EXPANSION_PARAMETER_PACKS (expr) =
18993 PACK_EXPANSION_PARAMETER_PACKS (TREE_PURPOSE (t));
18995 if (TREE_VALUE (t) == void_type_node)
18996 /* VOID_TYPE_NODE is used to indicate
18997 value-initialization. */
18999 for (i = 0; i < len; i++)
19000 TREE_VEC_ELT (expanded_arguments, i) = void_type_node;
19004 /* Substitute parameter packs into each argument in the
19006 in_base_initializer = 1;
19007 for (arg = TREE_VALUE (t); arg; arg = TREE_CHAIN (arg))
19009 tree expanded_exprs;
19011 /* Expand the argument. */
19012 SET_PACK_EXPANSION_PATTERN (expr, TREE_VALUE (arg));
19014 = tsubst_pack_expansion (expr, argvec,
19015 tf_warning_or_error,
19017 if (expanded_exprs == error_mark_node)
19020 /* Prepend each of the expanded expressions to the
19021 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
19022 for (i = 0; i < len; i++)
19024 TREE_VEC_ELT (expanded_arguments, i) =
19025 tree_cons (NULL_TREE,
19026 TREE_VEC_ELT (expanded_exprs, i),
19027 TREE_VEC_ELT (expanded_arguments, i));
19030 in_base_initializer = 0;
19032 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
19033 since we built them backwards. */
19034 for (i = 0; i < len; i++)
19036 TREE_VEC_ELT (expanded_arguments, i) =
19037 nreverse (TREE_VEC_ELT (expanded_arguments, i));
19042 for (i = 0; i < len; ++i)
19044 if (expanded_bases)
19046 decl = TREE_VEC_ELT (expanded_bases, i);
19047 decl = expand_member_init (decl);
19048 init = TREE_VEC_ELT (expanded_arguments, i);
19053 decl = tsubst_copy (TREE_PURPOSE (t), argvec,
19054 tf_warning_or_error, NULL_TREE);
19056 decl = expand_member_init (decl);
19057 if (decl && !DECL_P (decl))
19058 in_base_initializer = 1;
19060 init = TREE_VALUE (t);
19062 if (init != void_type_node)
19063 init = tsubst_expr (init, argvec,
19064 tf_warning_or_error, NULL_TREE,
19065 /*integral_constant_expression_p=*/false);
19066 if (init == NULL_TREE && tmp != NULL_TREE)
19067 /* If we had an initializer but it instantiated to nothing,
19068 value-initialize the object. This will only occur when
19069 the initializer was a pack expansion where the parameter
19070 packs used in that expansion were of length zero. */
19071 init = void_type_node;
19072 in_base_initializer = 0;
19077 init = build_tree_list (decl, init);
19078 TREE_CHAIN (init) = inits;
19086 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
19089 set_current_access_from_decl (tree decl)
19091 if (TREE_PRIVATE (decl))
19092 current_access_specifier = access_private_node;
19093 else if (TREE_PROTECTED (decl))
19094 current_access_specifier = access_protected_node;
19096 current_access_specifier = access_public_node;
19099 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
19100 is the instantiation (which should have been created with
19101 start_enum) and ARGS are the template arguments to use. */
19104 tsubst_enum (tree tag, tree newtag, tree args)
19108 if (SCOPED_ENUM_P (newtag))
19109 begin_scope (sk_scoped_enum, newtag);
19111 for (e = TYPE_VALUES (tag); e; e = TREE_CHAIN (e))
19116 decl = TREE_VALUE (e);
19117 /* Note that in a template enum, the TREE_VALUE is the
19118 CONST_DECL, not the corresponding INTEGER_CST. */
19119 value = tsubst_expr (DECL_INITIAL (decl),
19120 args, tf_warning_or_error, NULL_TREE,
19121 /*integral_constant_expression_p=*/true);
19123 /* Give this enumeration constant the correct access. */
19124 set_current_access_from_decl (decl);
19126 /* Actually build the enumerator itself. */
19128 (DECL_NAME (decl), value, newtag, DECL_SOURCE_LOCATION (decl));
19131 if (SCOPED_ENUM_P (newtag))
19134 finish_enum_value_list (newtag);
19135 finish_enum (newtag);
19137 DECL_SOURCE_LOCATION (TYPE_NAME (newtag))
19138 = DECL_SOURCE_LOCATION (TYPE_NAME (tag));
19141 /* DECL is a FUNCTION_DECL that is a template specialization. Return
19142 its type -- but without substituting the innermost set of template
19143 arguments. So, innermost set of template parameters will appear in
19147 get_mostly_instantiated_function_type (tree decl)
19155 tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
19156 targs = DECL_TI_ARGS (decl);
19157 tparms = DECL_TEMPLATE_PARMS (tmpl);
19158 parm_depth = TMPL_PARMS_DEPTH (tparms);
19160 /* There should be as many levels of arguments as there are levels
19162 gcc_assert (parm_depth == TMPL_ARGS_DEPTH (targs));
19164 fn_type = TREE_TYPE (tmpl);
19166 if (parm_depth == 1)
19167 /* No substitution is necessary. */
19174 /* Replace the innermost level of the TARGS with NULL_TREEs to
19175 let tsubst know not to substitute for those parameters. */
19176 partial_args = make_tree_vec (TREE_VEC_LENGTH (targs));
19177 for (i = 1; i < TMPL_ARGS_DEPTH (targs); ++i)
19178 SET_TMPL_ARGS_LEVEL (partial_args, i,
19179 TMPL_ARGS_LEVEL (targs, i));
19180 SET_TMPL_ARGS_LEVEL (partial_args,
19181 TMPL_ARGS_DEPTH (targs),
19182 make_tree_vec (DECL_NTPARMS (tmpl)));
19184 /* Make sure that we can see identifiers, and compute access
19186 push_access_scope (decl);
19188 ++processing_template_decl;
19189 /* Now, do the (partial) substitution to figure out the
19190 appropriate function type. */
19191 fn_type = tsubst (fn_type, partial_args, tf_error, NULL_TREE);
19192 --processing_template_decl;
19194 /* Substitute into the template parameters to obtain the real
19195 innermost set of parameters. This step is important if the
19196 innermost set of template parameters contains value
19197 parameters whose types depend on outer template parameters. */
19198 TREE_VEC_LENGTH (partial_args)--;
19199 tparms = tsubst_template_parms (tparms, partial_args, tf_error);
19201 pop_access_scope (decl);
19207 /* Return truthvalue if we're processing a template different from
19208 the last one involved in diagnostics. */
19210 problematic_instantiation_changed (void)
19212 return current_tinst_level != last_error_tinst_level;
19215 /* Remember current template involved in diagnostics. */
19217 record_last_problematic_instantiation (void)
19219 last_error_tinst_level = current_tinst_level;
19222 struct tinst_level *
19223 current_instantiation (void)
19225 return current_tinst_level;
19228 /* [temp.param] Check that template non-type parm TYPE is of an allowable
19229 type. Return zero for ok, nonzero for disallowed. Issue error and
19230 warning messages under control of COMPLAIN. */
19233 invalid_nontype_parm_type_p (tree type, tsubst_flags_t complain)
19235 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
19237 else if (POINTER_TYPE_P (type))
19239 else if (TYPE_PTR_TO_MEMBER_P (type))
19241 else if (TREE_CODE (type) == TEMPLATE_TYPE_PARM)
19243 else if (TREE_CODE (type) == TYPENAME_TYPE)
19245 else if (TREE_CODE (type) == DECLTYPE_TYPE)
19247 else if (TREE_CODE (type) == NULLPTR_TYPE)
19250 if (complain & tf_error)
19252 if (type == error_mark_node)
19253 inform (input_location, "invalid template non-type parameter");
19255 error ("%q#T is not a valid type for a template non-type parameter",
19261 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
19262 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
19265 dependent_type_p_r (tree type)
19271 A type is dependent if it is:
19273 -- a template parameter. Template template parameters are types
19274 for us (since TYPE_P holds true for them) so we handle
19276 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
19277 || TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM)
19279 /* -- a qualified-id with a nested-name-specifier which contains a
19280 class-name that names a dependent type or whose unqualified-id
19281 names a dependent type. */
19282 if (TREE_CODE (type) == TYPENAME_TYPE)
19284 /* -- a cv-qualified type where the cv-unqualified type is
19286 type = TYPE_MAIN_VARIANT (type);
19287 /* -- a compound type constructed from any dependent type. */
19288 if (TYPE_PTR_TO_MEMBER_P (type))
19289 return (dependent_type_p (TYPE_PTRMEM_CLASS_TYPE (type))
19290 || dependent_type_p (TYPE_PTRMEM_POINTED_TO_TYPE
19292 else if (TREE_CODE (type) == POINTER_TYPE
19293 || TREE_CODE (type) == REFERENCE_TYPE)
19294 return dependent_type_p (TREE_TYPE (type));
19295 else if (TREE_CODE (type) == FUNCTION_TYPE
19296 || TREE_CODE (type) == METHOD_TYPE)
19300 if (dependent_type_p (TREE_TYPE (type)))
19302 for (arg_type = TYPE_ARG_TYPES (type);
19304 arg_type = TREE_CHAIN (arg_type))
19305 if (dependent_type_p (TREE_VALUE (arg_type)))
19309 /* -- an array type constructed from any dependent type or whose
19310 size is specified by a constant expression that is
19313 We checked for type- and value-dependence of the bounds in
19314 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
19315 if (TREE_CODE (type) == ARRAY_TYPE)
19317 if (TYPE_DOMAIN (type)
19318 && dependent_type_p (TYPE_DOMAIN (type)))
19320 return dependent_type_p (TREE_TYPE (type));
19323 /* -- a template-id in which either the template name is a template
19325 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
19327 /* ... or any of the template arguments is a dependent type or
19328 an expression that is type-dependent or value-dependent. */
19329 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INFO (type)
19330 && (any_dependent_template_arguments_p
19331 (INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type)))))
19334 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
19335 dependent; if the argument of the `typeof' expression is not
19336 type-dependent, then it should already been have resolved. */
19337 if (TREE_CODE (type) == TYPEOF_TYPE
19338 || TREE_CODE (type) == DECLTYPE_TYPE
19339 || TREE_CODE (type) == UNDERLYING_TYPE)
19342 /* A template argument pack is dependent if any of its packed
19344 if (TREE_CODE (type) == TYPE_ARGUMENT_PACK)
19346 tree args = ARGUMENT_PACK_ARGS (type);
19347 int i, len = TREE_VEC_LENGTH (args);
19348 for (i = 0; i < len; ++i)
19349 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
19353 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
19354 be template parameters. */
19355 if (TREE_CODE (type) == TYPE_PACK_EXPANSION)
19358 /* The standard does not specifically mention types that are local
19359 to template functions or local classes, but they should be
19360 considered dependent too. For example:
19362 template <int I> void f() {
19367 The size of `E' cannot be known until the value of `I' has been
19368 determined. Therefore, `E' must be considered dependent. */
19369 scope = TYPE_CONTEXT (type);
19370 if (scope && TYPE_P (scope))
19371 return dependent_type_p (scope);
19372 /* Don't use type_dependent_expression_p here, as it can lead
19373 to infinite recursion trying to determine whether a lambda
19374 nested in a lambda is dependent (c++/47687). */
19375 else if (scope && TREE_CODE (scope) == FUNCTION_DECL
19376 && DECL_LANG_SPECIFIC (scope)
19377 && DECL_TEMPLATE_INFO (scope)
19378 && (any_dependent_template_arguments_p
19379 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (scope)))))
19382 /* Other types are non-dependent. */
19386 /* Returns TRUE if TYPE is dependent, in the sense of
19387 [temp.dep.type]. Note that a NULL type is considered dependent. */
19390 dependent_type_p (tree type)
19392 /* If there are no template parameters in scope, then there can't be
19393 any dependent types. */
19394 if (!processing_template_decl)
19396 /* If we are not processing a template, then nobody should be
19397 providing us with a dependent type. */
19399 gcc_assert (TREE_CODE (type) != TEMPLATE_TYPE_PARM || is_auto (type));
19403 /* If the type is NULL, we have not computed a type for the entity
19404 in question; in that case, the type is dependent. */
19408 /* Erroneous types can be considered non-dependent. */
19409 if (type == error_mark_node)
19412 /* If we have not already computed the appropriate value for TYPE,
19414 if (!TYPE_DEPENDENT_P_VALID (type))
19416 TYPE_DEPENDENT_P (type) = dependent_type_p_r (type);
19417 TYPE_DEPENDENT_P_VALID (type) = 1;
19420 return TYPE_DEPENDENT_P (type);
19423 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
19424 lookup. In other words, a dependent type that is not the current
19428 dependent_scope_p (tree scope)
19430 return (scope && TYPE_P (scope) && dependent_type_p (scope)
19431 && !currently_open_class (scope));
19434 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
19435 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
19438 /* Note that this predicate is not appropriate for general expressions;
19439 only constant expressions (that satisfy potential_constant_expression)
19440 can be tested for value dependence.
19442 We should really also have a predicate for "instantiation-dependent".
19444 fold_non_dependent_expr: fold if constant and not type-dependent and not value-dependent.
19445 (what about instantiation-dependent constant-expressions?)
19446 is_late_template_attribute: defer if instantiation-dependent.
19447 compute_array_index_type: proceed if constant and not t- or v-dependent
19448 if instantiation-dependent, need to remember full expression
19449 uses_template_parms: FIXME - need to audit callers
19450 tsubst_decl [function_decl]: Why is this using value_dependent_expression_p?
19451 dependent_type_p [array_type]: dependent if index type is dependent
19453 static_assert - instantiation-dependent */
19456 value_dependent_expression_p (tree expression)
19458 if (!processing_template_decl)
19461 /* A name declared with a dependent type. */
19462 if (DECL_P (expression) && type_dependent_expression_p (expression))
19465 switch (TREE_CODE (expression))
19467 case IDENTIFIER_NODE:
19468 /* A name that has not been looked up -- must be dependent. */
19471 case TEMPLATE_PARM_INDEX:
19472 /* A non-type template parm. */
19476 /* A non-type template parm. */
19477 if (DECL_TEMPLATE_PARM_P (expression))
19479 return value_dependent_expression_p (DECL_INITIAL (expression));
19482 /* A constant with literal type and is initialized
19483 with an expression that is value-dependent.
19485 Note that a non-dependent parenthesized initializer will have
19486 already been replaced with its constant value, so if we see
19487 a TREE_LIST it must be dependent. */
19488 if (DECL_INITIAL (expression)
19489 && decl_constant_var_p (expression)
19490 && (TREE_CODE (DECL_INITIAL (expression)) == TREE_LIST
19491 || value_dependent_expression_p (DECL_INITIAL (expression))))
19495 case DYNAMIC_CAST_EXPR:
19496 case STATIC_CAST_EXPR:
19497 case CONST_CAST_EXPR:
19498 case REINTERPRET_CAST_EXPR:
19500 /* These expressions are value-dependent if the type to which
19501 the cast occurs is dependent or the expression being casted
19502 is value-dependent. */
19504 tree type = TREE_TYPE (expression);
19506 if (dependent_type_p (type))
19509 /* A functional cast has a list of operands. */
19510 expression = TREE_OPERAND (expression, 0);
19513 /* If there are no operands, it must be an expression such
19514 as "int()". This should not happen for aggregate types
19515 because it would form non-constant expressions. */
19516 gcc_assert (cxx_dialect >= cxx0x
19517 || INTEGRAL_OR_ENUMERATION_TYPE_P (type));
19522 if (TREE_CODE (expression) == TREE_LIST)
19523 return any_value_dependent_elements_p (expression);
19525 return value_dependent_expression_p (expression);
19531 /* A `sizeof' expression is value-dependent if the operand is
19532 type-dependent or is a pack expansion. */
19533 expression = TREE_OPERAND (expression, 0);
19534 if (PACK_EXPANSION_P (expression))
19536 else if (TYPE_P (expression))
19537 return dependent_type_p (expression);
19538 return type_dependent_expression_p (expression);
19540 case AT_ENCODE_EXPR:
19541 /* An 'encode' expression is value-dependent if the operand is
19543 expression = TREE_OPERAND (expression, 0);
19544 return dependent_type_p (expression);
19546 case NOEXCEPT_EXPR:
19547 expression = TREE_OPERAND (expression, 0);
19548 return type_dependent_expression_p (expression);
19552 tree name = TREE_OPERAND (expression, 1);
19553 return value_dependent_expression_p (name);
19556 case COMPONENT_REF:
19557 return (value_dependent_expression_p (TREE_OPERAND (expression, 0))
19558 || value_dependent_expression_p (TREE_OPERAND (expression, 1)));
19560 case NONTYPE_ARGUMENT_PACK:
19561 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
19562 is value-dependent. */
19564 tree values = ARGUMENT_PACK_ARGS (expression);
19565 int i, len = TREE_VEC_LENGTH (values);
19567 for (i = 0; i < len; ++i)
19568 if (value_dependent_expression_p (TREE_VEC_ELT (values, i)))
19576 tree type2 = TRAIT_EXPR_TYPE2 (expression);
19577 return (dependent_type_p (TRAIT_EXPR_TYPE1 (expression))
19578 || (type2 ? dependent_type_p (type2) : false));
19582 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
19583 || (value_dependent_expression_p (TREE_OPERAND (expression, 2))));
19586 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
19587 || (value_dependent_expression_p (TREE_OPERAND (expression, 1))));
19591 tree op = TREE_OPERAND (expression, 0);
19592 return (value_dependent_expression_p (op)
19593 || has_value_dependent_address (op));
19598 tree fn = get_callee_fndecl (expression);
19600 if (!fn && value_dependent_expression_p (CALL_EXPR_FN (expression)))
19602 nargs = call_expr_nargs (expression);
19603 for (i = 0; i < nargs; ++i)
19605 tree op = CALL_EXPR_ARG (expression, i);
19606 /* In a call to a constexpr member function, look through the
19607 implicit ADDR_EXPR on the object argument so that it doesn't
19608 cause the call to be considered value-dependent. We also
19609 look through it in potential_constant_expression. */
19610 if (i == 0 && fn && DECL_DECLARED_CONSTEXPR_P (fn)
19611 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
19612 && TREE_CODE (op) == ADDR_EXPR)
19613 op = TREE_OPERAND (op, 0);
19614 if (value_dependent_expression_p (op))
19620 case TEMPLATE_ID_EXPR:
19621 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
19623 return type_dependent_expression_p (expression);
19629 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), ix, val)
19630 if (value_dependent_expression_p (val))
19636 /* Treat a GNU statement expression as dependent to avoid crashing
19637 under fold_non_dependent_expr; it can't be constant. */
19641 /* A constant expression is value-dependent if any subexpression is
19642 value-dependent. */
19643 switch (TREE_CODE_CLASS (TREE_CODE (expression)))
19645 case tcc_reference:
19647 case tcc_comparison:
19649 case tcc_expression:
19652 int i, len = cp_tree_operand_length (expression);
19654 for (i = 0; i < len; i++)
19656 tree t = TREE_OPERAND (expression, i);
19658 /* In some cases, some of the operands may be missing.l
19659 (For example, in the case of PREDECREMENT_EXPR, the
19660 amount to increment by may be missing.) That doesn't
19661 make the expression dependent. */
19662 if (t && value_dependent_expression_p (t))
19673 /* The expression is not value-dependent. */
19677 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
19678 [temp.dep.expr]. Note that an expression with no type is
19679 considered dependent. Other parts of the compiler arrange for an
19680 expression with type-dependent subexpressions to have no type, so
19681 this function doesn't have to be fully recursive. */
19684 type_dependent_expression_p (tree expression)
19686 if (!processing_template_decl)
19689 if (expression == error_mark_node)
19692 /* An unresolved name is always dependent. */
19693 if (TREE_CODE (expression) == IDENTIFIER_NODE
19694 || TREE_CODE (expression) == USING_DECL)
19697 /* Some expression forms are never type-dependent. */
19698 if (TREE_CODE (expression) == PSEUDO_DTOR_EXPR
19699 || TREE_CODE (expression) == SIZEOF_EXPR
19700 || TREE_CODE (expression) == ALIGNOF_EXPR
19701 || TREE_CODE (expression) == AT_ENCODE_EXPR
19702 || TREE_CODE (expression) == NOEXCEPT_EXPR
19703 || TREE_CODE (expression) == TRAIT_EXPR
19704 || TREE_CODE (expression) == TYPEID_EXPR
19705 || TREE_CODE (expression) == DELETE_EXPR
19706 || TREE_CODE (expression) == VEC_DELETE_EXPR
19707 || TREE_CODE (expression) == THROW_EXPR)
19710 /* The types of these expressions depends only on the type to which
19711 the cast occurs. */
19712 if (TREE_CODE (expression) == DYNAMIC_CAST_EXPR
19713 || TREE_CODE (expression) == STATIC_CAST_EXPR
19714 || TREE_CODE (expression) == CONST_CAST_EXPR
19715 || TREE_CODE (expression) == REINTERPRET_CAST_EXPR
19716 || TREE_CODE (expression) == IMPLICIT_CONV_EXPR
19717 || TREE_CODE (expression) == CAST_EXPR)
19718 return dependent_type_p (TREE_TYPE (expression));
19720 /* The types of these expressions depends only on the type created
19721 by the expression. */
19722 if (TREE_CODE (expression) == NEW_EXPR
19723 || TREE_CODE (expression) == VEC_NEW_EXPR)
19725 /* For NEW_EXPR tree nodes created inside a template, either
19726 the object type itself or a TREE_LIST may appear as the
19728 tree type = TREE_OPERAND (expression, 1);
19729 if (TREE_CODE (type) == TREE_LIST)
19730 /* This is an array type. We need to check array dimensions
19732 return dependent_type_p (TREE_VALUE (TREE_PURPOSE (type)))
19733 || value_dependent_expression_p
19734 (TREE_OPERAND (TREE_VALUE (type), 1));
19736 return dependent_type_p (type);
19739 if (TREE_CODE (expression) == SCOPE_REF)
19741 tree scope = TREE_OPERAND (expression, 0);
19742 tree name = TREE_OPERAND (expression, 1);
19744 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
19745 contains an identifier associated by name lookup with one or more
19746 declarations declared with a dependent type, or...a
19747 nested-name-specifier or qualified-id that names a member of an
19748 unknown specialization. */
19749 return (type_dependent_expression_p (name)
19750 || dependent_scope_p (scope));
19753 if (TREE_CODE (expression) == FUNCTION_DECL
19754 && DECL_LANG_SPECIFIC (expression)
19755 && DECL_TEMPLATE_INFO (expression)
19756 && (any_dependent_template_arguments_p
19757 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (expression)))))
19760 if (TREE_CODE (expression) == TEMPLATE_DECL
19761 && !DECL_TEMPLATE_TEMPLATE_PARM_P (expression))
19764 if (TREE_CODE (expression) == STMT_EXPR)
19765 expression = stmt_expr_value_expr (expression);
19767 if (BRACE_ENCLOSED_INITIALIZER_P (expression))
19772 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), i, elt)
19774 if (type_dependent_expression_p (elt))
19780 /* A static data member of the current instantiation with incomplete
19781 array type is type-dependent, as the definition and specializations
19782 can have different bounds. */
19783 if (TREE_CODE (expression) == VAR_DECL
19784 && DECL_CLASS_SCOPE_P (expression)
19785 && dependent_type_p (DECL_CONTEXT (expression))
19786 && VAR_HAD_UNKNOWN_BOUND (expression))
19789 if (TREE_TYPE (expression) == unknown_type_node)
19791 if (TREE_CODE (expression) == ADDR_EXPR)
19792 return type_dependent_expression_p (TREE_OPERAND (expression, 0));
19793 if (TREE_CODE (expression) == COMPONENT_REF
19794 || TREE_CODE (expression) == OFFSET_REF)
19796 if (type_dependent_expression_p (TREE_OPERAND (expression, 0)))
19798 expression = TREE_OPERAND (expression, 1);
19799 if (TREE_CODE (expression) == IDENTIFIER_NODE)
19802 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
19803 if (TREE_CODE (expression) == SCOPE_REF)
19806 if (BASELINK_P (expression))
19807 expression = BASELINK_FUNCTIONS (expression);
19809 if (TREE_CODE (expression) == TEMPLATE_ID_EXPR)
19811 if (any_dependent_template_arguments_p
19812 (TREE_OPERAND (expression, 1)))
19814 expression = TREE_OPERAND (expression, 0);
19816 gcc_assert (TREE_CODE (expression) == OVERLOAD
19817 || TREE_CODE (expression) == FUNCTION_DECL);
19821 if (type_dependent_expression_p (OVL_CURRENT (expression)))
19823 expression = OVL_NEXT (expression);
19828 gcc_assert (TREE_CODE (expression) != TYPE_DECL);
19830 return (dependent_type_p (TREE_TYPE (expression)));
19833 /* Like type_dependent_expression_p, but it also works while not processing
19834 a template definition, i.e. during substitution or mangling. */
19837 type_dependent_expression_p_push (tree expr)
19840 ++processing_template_decl;
19841 b = type_dependent_expression_p (expr);
19842 --processing_template_decl;
19846 /* Returns TRUE if ARGS contains a type-dependent expression. */
19849 any_type_dependent_arguments_p (const VEC(tree,gc) *args)
19854 FOR_EACH_VEC_ELT (tree, args, i, arg)
19856 if (type_dependent_expression_p (arg))
19862 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
19863 expressions) contains any type-dependent expressions. */
19866 any_type_dependent_elements_p (const_tree list)
19868 for (; list; list = TREE_CHAIN (list))
19869 if (value_dependent_expression_p (TREE_VALUE (list)))
19875 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
19876 expressions) contains any value-dependent expressions. */
19879 any_value_dependent_elements_p (const_tree list)
19881 for (; list; list = TREE_CHAIN (list))
19882 if (value_dependent_expression_p (TREE_VALUE (list)))
19888 /* Returns TRUE if the ARG (a template argument) is dependent. */
19891 dependent_template_arg_p (tree arg)
19893 if (!processing_template_decl)
19896 /* Assume a template argument that was wrongly written by the user
19897 is dependent. This is consistent with what
19898 any_dependent_template_arguments_p [that calls this function]
19900 if (!arg || arg == error_mark_node)
19903 if (TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
19904 arg = ARGUMENT_PACK_SELECT_ARG (arg);
19906 if (TREE_CODE (arg) == TEMPLATE_DECL
19907 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
19908 return dependent_template_p (arg);
19909 else if (ARGUMENT_PACK_P (arg))
19911 tree args = ARGUMENT_PACK_ARGS (arg);
19912 int i, len = TREE_VEC_LENGTH (args);
19913 for (i = 0; i < len; ++i)
19915 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
19921 else if (TYPE_P (arg))
19922 return dependent_type_p (arg);
19924 return (type_dependent_expression_p (arg)
19925 || value_dependent_expression_p (arg));
19928 /* Returns true if ARGS (a collection of template arguments) contains
19929 any types that require structural equality testing. */
19932 any_template_arguments_need_structural_equality_p (tree args)
19939 if (args == error_mark_node)
19942 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
19944 tree level = TMPL_ARGS_LEVEL (args, i + 1);
19945 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
19947 tree arg = TREE_VEC_ELT (level, j);
19948 tree packed_args = NULL_TREE;
19951 if (ARGUMENT_PACK_P (arg))
19953 /* Look inside the argument pack. */
19954 packed_args = ARGUMENT_PACK_ARGS (arg);
19955 len = TREE_VEC_LENGTH (packed_args);
19958 for (k = 0; k < len; ++k)
19961 arg = TREE_VEC_ELT (packed_args, k);
19963 if (error_operand_p (arg))
19965 else if (TREE_CODE (arg) == TEMPLATE_DECL
19966 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
19968 else if (TYPE_P (arg) && TYPE_STRUCTURAL_EQUALITY_P (arg))
19970 else if (!TYPE_P (arg) && TREE_TYPE (arg)
19971 && TYPE_STRUCTURAL_EQUALITY_P (TREE_TYPE (arg)))
19980 /* Returns true if ARGS (a collection of template arguments) contains
19981 any dependent arguments. */
19984 any_dependent_template_arguments_p (const_tree args)
19991 if (args == error_mark_node)
19994 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
19996 const_tree level = TMPL_ARGS_LEVEL (args, i + 1);
19997 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
19998 if (dependent_template_arg_p (TREE_VEC_ELT (level, j)))
20005 /* Returns TRUE if the template TMPL is dependent. */
20008 dependent_template_p (tree tmpl)
20010 if (TREE_CODE (tmpl) == OVERLOAD)
20014 if (dependent_template_p (OVL_CURRENT (tmpl)))
20016 tmpl = OVL_NEXT (tmpl);
20021 /* Template template parameters are dependent. */
20022 if (DECL_TEMPLATE_TEMPLATE_PARM_P (tmpl)
20023 || TREE_CODE (tmpl) == TEMPLATE_TEMPLATE_PARM)
20025 /* So are names that have not been looked up. */
20026 if (TREE_CODE (tmpl) == SCOPE_REF
20027 || TREE_CODE (tmpl) == IDENTIFIER_NODE)
20029 /* So are member templates of dependent classes. */
20030 if (TYPE_P (CP_DECL_CONTEXT (tmpl)))
20031 return dependent_type_p (DECL_CONTEXT (tmpl));
20035 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
20038 dependent_template_id_p (tree tmpl, tree args)
20040 return (dependent_template_p (tmpl)
20041 || any_dependent_template_arguments_p (args));
20044 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
20048 dependent_omp_for_p (tree declv, tree initv, tree condv, tree incrv)
20052 if (!processing_template_decl)
20055 for (i = 0; i < TREE_VEC_LENGTH (declv); i++)
20057 tree decl = TREE_VEC_ELT (declv, i);
20058 tree init = TREE_VEC_ELT (initv, i);
20059 tree cond = TREE_VEC_ELT (condv, i);
20060 tree incr = TREE_VEC_ELT (incrv, i);
20062 if (type_dependent_expression_p (decl))
20065 if (init && type_dependent_expression_p (init))
20068 if (type_dependent_expression_p (cond))
20071 if (COMPARISON_CLASS_P (cond)
20072 && (type_dependent_expression_p (TREE_OPERAND (cond, 0))
20073 || type_dependent_expression_p (TREE_OPERAND (cond, 1))))
20076 if (TREE_CODE (incr) == MODOP_EXPR)
20078 if (type_dependent_expression_p (TREE_OPERAND (incr, 0))
20079 || type_dependent_expression_p (TREE_OPERAND (incr, 2)))
20082 else if (type_dependent_expression_p (incr))
20084 else if (TREE_CODE (incr) == MODIFY_EXPR)
20086 if (type_dependent_expression_p (TREE_OPERAND (incr, 0)))
20088 else if (BINARY_CLASS_P (TREE_OPERAND (incr, 1)))
20090 tree t = TREE_OPERAND (incr, 1);
20091 if (type_dependent_expression_p (TREE_OPERAND (t, 0))
20092 || type_dependent_expression_p (TREE_OPERAND (t, 1)))
20101 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
20102 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
20103 no such TYPE can be found. Note that this function peers inside
20104 uninstantiated templates and therefore should be used only in
20105 extremely limited situations. ONLY_CURRENT_P restricts this
20106 peering to the currently open classes hierarchy (which is required
20107 when comparing types). */
20110 resolve_typename_type (tree type, bool only_current_p)
20119 gcc_assert (TREE_CODE (type) == TYPENAME_TYPE);
20121 scope = TYPE_CONTEXT (type);
20122 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
20123 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
20124 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
20125 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
20126 identifier of the TYPENAME_TYPE anymore.
20127 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
20128 TYPENAME_TYPE instead, we avoid messing up with a possible
20129 typedef variant case. */
20130 name = TYPE_IDENTIFIER (TYPE_MAIN_VARIANT (type));
20132 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
20133 it first before we can figure out what NAME refers to. */
20134 if (TREE_CODE (scope) == TYPENAME_TYPE)
20135 scope = resolve_typename_type (scope, only_current_p);
20136 /* If we don't know what SCOPE refers to, then we cannot resolve the
20138 if (TREE_CODE (scope) == TYPENAME_TYPE)
20140 /* If the SCOPE is a template type parameter, we have no way of
20141 resolving the name. */
20142 if (TREE_CODE (scope) == TEMPLATE_TYPE_PARM)
20144 /* If the SCOPE is not the current instantiation, there's no reason
20145 to look inside it. */
20146 if (only_current_p && !currently_open_class (scope))
20148 /* If this is a typedef, we don't want to look inside (c++/11987). */
20149 if (typedef_variant_p (type))
20151 /* If SCOPE isn't the template itself, it will not have a valid
20152 TYPE_FIELDS list. */
20153 if (same_type_p (scope, CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope)))
20154 /* scope is either the template itself or a compatible instantiation
20155 like X<T>, so look up the name in the original template. */
20156 scope = CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope);
20158 /* scope is a partial instantiation, so we can't do the lookup or we
20159 will lose the template arguments. */
20161 /* Enter the SCOPE so that name lookup will be resolved as if we
20162 were in the class definition. In particular, SCOPE will no
20163 longer be considered a dependent type. */
20164 pushed_scope = push_scope (scope);
20165 /* Look up the declaration. */
20166 decl = lookup_member (scope, name, /*protect=*/0, /*want_type=*/true,
20167 tf_warning_or_error);
20169 result = NULL_TREE;
20171 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
20172 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
20175 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == IDENTIFIER_NODE
20176 && TREE_CODE (decl) == TYPE_DECL)
20178 result = TREE_TYPE (decl);
20179 if (result == error_mark_node)
20180 result = NULL_TREE;
20182 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == TEMPLATE_ID_EXPR
20183 && DECL_CLASS_TEMPLATE_P (decl))
20187 /* Obtain the template and the arguments. */
20188 tmpl = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 0);
20189 args = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 1);
20190 /* Instantiate the template. */
20191 result = lookup_template_class (tmpl, args, NULL_TREE, NULL_TREE,
20192 /*entering_scope=*/0,
20193 tf_error | tf_user);
20194 if (result == error_mark_node)
20195 result = NULL_TREE;
20198 /* Leave the SCOPE. */
20200 pop_scope (pushed_scope);
20202 /* If we failed to resolve it, return the original typename. */
20206 /* If lookup found a typename type, resolve that too. */
20207 if (TREE_CODE (result) == TYPENAME_TYPE && !TYPENAME_IS_RESOLVING_P (result))
20209 /* Ill-formed programs can cause infinite recursion here, so we
20210 must catch that. */
20211 TYPENAME_IS_RESOLVING_P (type) = 1;
20212 result = resolve_typename_type (result, only_current_p);
20213 TYPENAME_IS_RESOLVING_P (type) = 0;
20216 /* Qualify the resulting type. */
20217 quals = cp_type_quals (type);
20219 result = cp_build_qualified_type (result, cp_type_quals (result) | quals);
20224 /* EXPR is an expression which is not type-dependent. Return a proxy
20225 for EXPR that can be used to compute the types of larger
20226 expressions containing EXPR. */
20229 build_non_dependent_expr (tree expr)
20233 #ifdef ENABLE_CHECKING
20234 /* Try to get a constant value for all non-type-dependent expressions in
20235 order to expose bugs in *_dependent_expression_p and constexpr. */
20236 if (cxx_dialect >= cxx0x)
20237 maybe_constant_value (fold_non_dependent_expr_sfinae (expr, tf_none));
20240 /* Preserve OVERLOADs; the functions must be available to resolve
20243 if (TREE_CODE (inner_expr) == STMT_EXPR)
20244 inner_expr = stmt_expr_value_expr (inner_expr);
20245 if (TREE_CODE (inner_expr) == ADDR_EXPR)
20246 inner_expr = TREE_OPERAND (inner_expr, 0);
20247 if (TREE_CODE (inner_expr) == COMPONENT_REF)
20248 inner_expr = TREE_OPERAND (inner_expr, 1);
20249 if (is_overloaded_fn (inner_expr)
20250 || TREE_CODE (inner_expr) == OFFSET_REF)
20252 /* There is no need to return a proxy for a variable. */
20253 if (TREE_CODE (expr) == VAR_DECL)
20255 /* Preserve string constants; conversions from string constants to
20256 "char *" are allowed, even though normally a "const char *"
20257 cannot be used to initialize a "char *". */
20258 if (TREE_CODE (expr) == STRING_CST)
20260 /* Preserve arithmetic constants, as an optimization -- there is no
20261 reason to create a new node. */
20262 if (TREE_CODE (expr) == INTEGER_CST || TREE_CODE (expr) == REAL_CST)
20264 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
20265 There is at least one place where we want to know that a
20266 particular expression is a throw-expression: when checking a ?:
20267 expression, there are special rules if the second or third
20268 argument is a throw-expression. */
20269 if (TREE_CODE (expr) == THROW_EXPR)
20272 /* Don't wrap an initializer list, we need to be able to look inside. */
20273 if (BRACE_ENCLOSED_INITIALIZER_P (expr))
20276 if (TREE_CODE (expr) == COND_EXPR)
20277 return build3 (COND_EXPR,
20279 TREE_OPERAND (expr, 0),
20280 (TREE_OPERAND (expr, 1)
20281 ? build_non_dependent_expr (TREE_OPERAND (expr, 1))
20282 : build_non_dependent_expr (TREE_OPERAND (expr, 0))),
20283 build_non_dependent_expr (TREE_OPERAND (expr, 2)));
20284 if (TREE_CODE (expr) == COMPOUND_EXPR
20285 && !COMPOUND_EXPR_OVERLOADED (expr))
20286 return build2 (COMPOUND_EXPR,
20288 TREE_OPERAND (expr, 0),
20289 build_non_dependent_expr (TREE_OPERAND (expr, 1)));
20291 /* If the type is unknown, it can't really be non-dependent */
20292 gcc_assert (TREE_TYPE (expr) != unknown_type_node);
20294 /* Otherwise, build a NON_DEPENDENT_EXPR. */
20295 return build1 (NON_DEPENDENT_EXPR, TREE_TYPE (expr), expr);
20298 /* ARGS is a vector of expressions as arguments to a function call.
20299 Replace the arguments with equivalent non-dependent expressions.
20300 This modifies ARGS in place. */
20303 make_args_non_dependent (VEC(tree,gc) *args)
20308 FOR_EACH_VEC_ELT (tree, args, ix, arg)
20310 tree newarg = build_non_dependent_expr (arg);
20312 VEC_replace (tree, args, ix, newarg);
20316 /* Returns a type which represents 'auto'. We use a TEMPLATE_TYPE_PARM
20317 with a level one deeper than the actual template parms. */
20322 tree au = cxx_make_type (TEMPLATE_TYPE_PARM);
20323 TYPE_NAME (au) = build_decl (BUILTINS_LOCATION,
20324 TYPE_DECL, get_identifier ("auto"), au);
20325 TYPE_STUB_DECL (au) = TYPE_NAME (au);
20326 TEMPLATE_TYPE_PARM_INDEX (au) = build_template_parm_index
20327 (0, processing_template_decl + 1, processing_template_decl + 1,
20328 0, TYPE_NAME (au), NULL_TREE);
20329 TYPE_CANONICAL (au) = canonical_type_parameter (au);
20330 DECL_ARTIFICIAL (TYPE_NAME (au)) = 1;
20331 SET_DECL_TEMPLATE_PARM_P (TYPE_NAME (au));
20336 /* Given type ARG, return std::initializer_list<ARG>. */
20341 tree std_init_list = namespace_binding
20342 (get_identifier ("initializer_list"), std_node);
20344 if (!std_init_list || !DECL_CLASS_TEMPLATE_P (std_init_list))
20346 error ("deducing from brace-enclosed initializer list requires "
20347 "#include <initializer_list>");
20348 return error_mark_node;
20350 argvec = make_tree_vec (1);
20351 TREE_VEC_ELT (argvec, 0) = arg;
20352 return lookup_template_class (std_init_list, argvec, NULL_TREE,
20353 NULL_TREE, 0, tf_warning_or_error);
20356 /* Replace auto in TYPE with std::initializer_list<auto>. */
20359 listify_autos (tree type, tree auto_node)
20361 tree init_auto = listify (auto_node);
20362 tree argvec = make_tree_vec (1);
20363 TREE_VEC_ELT (argvec, 0) = init_auto;
20364 if (processing_template_decl)
20365 argvec = add_to_template_args (current_template_args (), argvec);
20366 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
20369 /* walk_tree helper for do_auto_deduction. */
20372 contains_auto_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
20375 /* Is this a variable with the type we're looking for? */
20377 && TREE_TYPE (*tp) == type)
20383 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
20384 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
20387 do_auto_deduction (tree type, tree init, tree auto_node)
20389 tree parms, tparms, targs;
20394 if (type_dependent_expression_p (init))
20395 /* Defining a subset of type-dependent expressions that we can deduce
20396 from ahead of time isn't worth the trouble. */
20399 /* The name of the object being declared shall not appear in the
20400 initializer expression. */
20401 decl = cp_walk_tree_without_duplicates (&init, contains_auto_r, type);
20404 error ("variable %q#D with %<auto%> type used in its own "
20405 "initializer", decl);
20406 return error_mark_node;
20409 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
20410 with either a new invented type template parameter U or, if the
20411 initializer is a braced-init-list (8.5.4), with
20412 std::initializer_list<U>. */
20413 if (BRACE_ENCLOSED_INITIALIZER_P (init))
20414 type = listify_autos (type, auto_node);
20416 init = resolve_nondeduced_context (init);
20418 parms = build_tree_list (NULL_TREE, type);
20420 tparms = make_tree_vec (1);
20421 targs = make_tree_vec (1);
20422 TREE_VEC_ELT (tparms, 0)
20423 = build_tree_list (NULL_TREE, TYPE_NAME (auto_node));
20424 val = type_unification_real (tparms, targs, parms, args, 1, 0,
20425 DEDUCE_CALL, LOOKUP_NORMAL,
20426 /*explain_p=*/false);
20429 if (processing_template_decl)
20430 /* Try again at instantiation time. */
20432 if (type && type != error_mark_node)
20433 /* If type is error_mark_node a diagnostic must have been
20434 emitted by now. Also, having a mention to '<type error>'
20435 in the diagnostic is not really useful to the user. */
20436 error ("unable to deduce %qT from %qE", type, init);
20437 return error_mark_node;
20440 /* If the list of declarators contains more than one declarator, the type
20441 of each declared variable is determined as described above. If the
20442 type deduced for the template parameter U is not the same in each
20443 deduction, the program is ill-formed. */
20444 if (TREE_TYPE (auto_node)
20445 && !same_type_p (TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0)))
20447 error ("inconsistent deduction for %qT: %qT and then %qT",
20448 auto_node, TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0));
20449 return error_mark_node;
20451 TREE_TYPE (auto_node) = TREE_VEC_ELT (targs, 0);
20453 if (processing_template_decl)
20454 targs = add_to_template_args (current_template_args (), targs);
20455 return tsubst (type, targs, tf_warning_or_error, NULL_TREE);
20458 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
20462 splice_late_return_type (tree type, tree late_return_type)
20466 if (late_return_type == NULL_TREE)
20468 argvec = make_tree_vec (1);
20469 TREE_VEC_ELT (argvec, 0) = late_return_type;
20470 if (processing_template_parmlist)
20471 /* For a late-specified return type in a template type-parameter, we
20472 need to add a dummy argument level for its parmlist. */
20473 argvec = add_to_template_args
20474 (make_tree_vec (processing_template_parmlist), argvec);
20475 if (current_template_parms)
20476 argvec = add_to_template_args (current_template_args (), argvec);
20477 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
20480 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto'. */
20483 is_auto (const_tree type)
20485 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
20486 && TYPE_IDENTIFIER (type) == get_identifier ("auto"))
20492 /* Returns true iff TYPE contains a use of 'auto'. Since auto can only
20493 appear as a type-specifier for the declaration in question, we don't
20494 have to look through the whole type. */
20497 type_uses_auto (tree type)
20499 enum tree_code code;
20500 if (is_auto (type))
20503 code = TREE_CODE (type);
20505 if (code == POINTER_TYPE || code == REFERENCE_TYPE
20506 || code == OFFSET_TYPE || code == FUNCTION_TYPE
20507 || code == METHOD_TYPE || code == ARRAY_TYPE)
20508 return type_uses_auto (TREE_TYPE (type));
20510 if (TYPE_PTRMEMFUNC_P (type))
20511 return type_uses_auto (TREE_TYPE (TREE_TYPE
20512 (TYPE_PTRMEMFUNC_FN_TYPE (type))));
20517 /* For a given template T, return the vector of typedefs referenced
20518 in T for which access check is needed at T instantiation time.
20519 T is either a FUNCTION_DECL or a RECORD_TYPE.
20520 Those typedefs were added to T by the function
20521 append_type_to_template_for_access_check. */
20523 VEC(qualified_typedef_usage_t,gc)*
20524 get_types_needing_access_check (tree t)
20527 VEC(qualified_typedef_usage_t,gc) *result = NULL;
20529 if (!t || t == error_mark_node)
20532 if (!(ti = get_template_info (t)))
20535 if (CLASS_TYPE_P (t)
20536 || TREE_CODE (t) == FUNCTION_DECL)
20538 if (!TI_TEMPLATE (ti))
20541 result = TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti);
20547 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
20548 tied to T. That list of typedefs will be access checked at
20549 T instantiation time.
20550 T is either a FUNCTION_DECL or a RECORD_TYPE.
20551 TYPE_DECL is a TYPE_DECL node representing a typedef.
20552 SCOPE is the scope through which TYPE_DECL is accessed.
20553 LOCATION is the location of the usage point of TYPE_DECL.
20555 This function is a subroutine of
20556 append_type_to_template_for_access_check. */
20559 append_type_to_template_for_access_check_1 (tree t,
20562 location_t location)
20564 qualified_typedef_usage_t typedef_usage;
20567 if (!t || t == error_mark_node)
20570 gcc_assert ((TREE_CODE (t) == FUNCTION_DECL
20571 || CLASS_TYPE_P (t))
20573 && TREE_CODE (type_decl) == TYPE_DECL
20576 if (!(ti = get_template_info (t)))
20579 gcc_assert (TI_TEMPLATE (ti));
20581 typedef_usage.typedef_decl = type_decl;
20582 typedef_usage.context = scope;
20583 typedef_usage.locus = location;
20585 VEC_safe_push (qualified_typedef_usage_t, gc,
20586 TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti),
20590 /* Append TYPE_DECL to the template TEMPL.
20591 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
20592 At TEMPL instanciation time, TYPE_DECL will be checked to see
20593 if it can be accessed through SCOPE.
20594 LOCATION is the location of the usage point of TYPE_DECL.
20596 e.g. consider the following code snippet:
20603 template<class U> struct S
20605 C::myint mi; // <-- usage point of the typedef C::myint
20610 At S<char> instantiation time, we need to check the access of C::myint
20611 In other words, we need to check the access of the myint typedef through
20612 the C scope. For that purpose, this function will add the myint typedef
20613 and the scope C through which its being accessed to a list of typedefs
20614 tied to the template S. That list will be walked at template instantiation
20615 time and access check performed on each typedefs it contains.
20616 Note that this particular code snippet should yield an error because
20617 myint is private to C. */
20620 append_type_to_template_for_access_check (tree templ,
20623 location_t location)
20625 qualified_typedef_usage_t *iter;
20628 gcc_assert (type_decl && (TREE_CODE (type_decl) == TYPE_DECL));
20630 /* Make sure we don't append the type to the template twice. */
20631 FOR_EACH_VEC_ELT (qualified_typedef_usage_t,
20632 get_types_needing_access_check (templ),
20634 if (iter->typedef_decl == type_decl && scope == iter->context)
20637 append_type_to_template_for_access_check_1 (templ, type_decl,
20641 /* Set up the hash tables for template instantiations. */
20644 init_template_processing (void)
20646 decl_specializations = htab_create_ggc (37,
20647 hash_specialization,
20648 eq_specializations,
20650 type_specializations = htab_create_ggc (37,
20651 hash_specialization,
20652 eq_specializations,
20656 /* Print stats about the template hash tables for -fstats. */
20659 print_template_statistics (void)
20661 fprintf (stderr, "decl_specializations: size %ld, %ld elements, "
20662 "%f collisions\n", (long) htab_size (decl_specializations),
20663 (long) htab_elements (decl_specializations),
20664 htab_collisions (decl_specializations));
20665 fprintf (stderr, "type_specializations: size %ld, %ld elements, "
20666 "%f collisions\n", (long) htab_size (type_specializations),
20667 (long) htab_elements (type_specializations),
20668 htab_collisions (type_specializations));
20671 #include "gt-cp-pt.h"