1 /* Handle parameterized types (templates) for GNU C++.
2 Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
3 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010, 2011
4 Free Software Foundation, Inc.
5 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
6 Rewritten by Jason Merrill (jason@cygnus.com).
8 This file is part of GCC.
10 GCC is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3, or (at your option)
15 GCC is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with GCC; see the file COPYING3. If not see
22 <http://www.gnu.org/licenses/>. */
24 /* Known bugs or deficiencies include:
26 all methods must be provided in header files; can't use a source
27 file that contains only the method templates and "just win". */
31 #include "coretypes.h"
35 #include "pointer-set.h"
38 #include "c-family/c-common.h"
39 #include "c-family/c-objc.h"
40 #include "cp-objcp-common.h"
41 #include "tree-inline.h"
46 #include "tree-iterator.h"
49 /* The type of functions taking a tree, and some additional data, and
51 typedef int (*tree_fn_t) (tree, void*);
53 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
54 instantiations have been deferred, either because their definitions
55 were not yet available, or because we were putting off doing the work. */
56 struct GTY ((chain_next ("%h.next"))) pending_template {
57 struct pending_template *next;
58 struct tinst_level *tinst;
61 static GTY(()) struct pending_template *pending_templates;
62 static GTY(()) struct pending_template *last_pending_template;
64 int processing_template_parmlist;
65 static int template_header_count;
67 static GTY(()) tree saved_trees;
68 static VEC(int,heap) *inline_parm_levels;
70 static GTY(()) struct tinst_level *current_tinst_level;
72 static GTY(()) tree saved_access_scope;
74 /* Live only within one (recursive) call to tsubst_expr. We use
75 this to pass the statement expression node from the STMT_EXPR
76 to the EXPR_STMT that is its result. */
77 static tree cur_stmt_expr;
79 /* A map from local variable declarations in the body of the template
80 presently being instantiated to the corresponding instantiated
82 static htab_t local_specializations;
84 typedef struct GTY(()) spec_entry
91 static GTY ((param_is (spec_entry)))
92 htab_t decl_specializations;
94 static GTY ((param_is (spec_entry)))
95 htab_t type_specializations;
97 /* Contains canonical template parameter types. The vector is indexed by
98 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
99 TREE_LIST, whose TREE_VALUEs contain the canonical template
100 parameters of various types and levels. */
101 static GTY(()) VEC(tree,gc) *canonical_template_parms;
103 #define UNIFY_ALLOW_NONE 0
104 #define UNIFY_ALLOW_MORE_CV_QUAL 1
105 #define UNIFY_ALLOW_LESS_CV_QUAL 2
106 #define UNIFY_ALLOW_DERIVED 4
107 #define UNIFY_ALLOW_INTEGER 8
108 #define UNIFY_ALLOW_OUTER_LEVEL 16
109 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
110 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
112 enum template_base_result {
114 tbr_ambiguous_baseclass,
118 static void push_access_scope (tree);
119 static void pop_access_scope (tree);
120 static void push_deduction_access_scope (tree);
121 static void pop_deduction_access_scope (tree);
122 static bool resolve_overloaded_unification (tree, tree, tree, tree,
123 unification_kind_t, int,
125 static int try_one_overload (tree, tree, tree, tree, tree,
126 unification_kind_t, int, bool, bool);
127 static int unify (tree, tree, tree, tree, int, bool);
128 static void add_pending_template (tree);
129 static tree reopen_tinst_level (struct tinst_level *);
130 static tree tsubst_initializer_list (tree, tree);
131 static tree get_class_bindings (tree, tree, tree);
132 static tree coerce_template_parms (tree, tree, tree, tsubst_flags_t,
134 static void tsubst_enum (tree, tree, tree);
135 static tree add_to_template_args (tree, tree);
136 static tree add_outermost_template_args (tree, tree);
137 static bool check_instantiated_args (tree, tree, tsubst_flags_t);
138 static int maybe_adjust_types_for_deduction (unification_kind_t, tree*, tree*,
140 static int type_unification_real (tree, tree, tree, const tree *,
141 unsigned int, int, unification_kind_t, int,
143 static void note_template_header (int);
144 static tree convert_nontype_argument_function (tree, tree);
145 static tree convert_nontype_argument (tree, tree, tsubst_flags_t);
146 static tree convert_template_argument (tree, tree, tree,
147 tsubst_flags_t, int, tree);
148 static int for_each_template_parm (tree, tree_fn_t, void*,
149 struct pointer_set_t*, bool);
150 static tree expand_template_argument_pack (tree);
151 static tree build_template_parm_index (int, int, int, int, tree, tree);
152 static bool inline_needs_template_parms (tree);
153 static void push_inline_template_parms_recursive (tree, int);
154 static tree retrieve_local_specialization (tree);
155 static void register_local_specialization (tree, tree);
156 static hashval_t hash_specialization (const void *p);
157 static tree reduce_template_parm_level (tree, tree, int, tree, tsubst_flags_t);
158 static int mark_template_parm (tree, void *);
159 static int template_parm_this_level_p (tree, void *);
160 static tree tsubst_friend_function (tree, tree);
161 static tree tsubst_friend_class (tree, tree);
162 static int can_complete_type_without_circularity (tree);
163 static tree get_bindings (tree, tree, tree, bool);
164 static int template_decl_level (tree);
165 static int check_cv_quals_for_unify (int, tree, tree);
166 static void template_parm_level_and_index (tree, int*, int*);
167 static int unify_pack_expansion (tree, tree, tree,
168 tree, unification_kind_t, bool, bool);
169 static tree tsubst_template_arg (tree, tree, tsubst_flags_t, tree);
170 static tree tsubst_template_args (tree, tree, tsubst_flags_t, tree);
171 static tree tsubst_template_parms (tree, tree, tsubst_flags_t);
172 static void regenerate_decl_from_template (tree, tree);
173 static tree most_specialized_class (tree, tree, tsubst_flags_t);
174 static tree tsubst_aggr_type (tree, tree, tsubst_flags_t, tree, int);
175 static tree tsubst_arg_types (tree, tree, tsubst_flags_t, tree);
176 static tree tsubst_function_type (tree, tree, tsubst_flags_t, tree);
177 static bool check_specialization_scope (void);
178 static tree process_partial_specialization (tree);
179 static void set_current_access_from_decl (tree);
180 static enum template_base_result get_template_base (tree, tree, tree, tree,
182 static tree try_class_unification (tree, tree, tree, tree, bool);
183 static int coerce_template_template_parms (tree, tree, tsubst_flags_t,
185 static bool template_template_parm_bindings_ok_p (tree, tree);
186 static int template_args_equal (tree, tree);
187 static void tsubst_default_arguments (tree);
188 static tree for_each_template_parm_r (tree *, int *, void *);
189 static tree copy_default_args_to_explicit_spec_1 (tree, tree);
190 static void copy_default_args_to_explicit_spec (tree);
191 static int invalid_nontype_parm_type_p (tree, tsubst_flags_t);
192 static int eq_local_specializations (const void *, const void *);
193 static bool dependent_template_arg_p (tree);
194 static bool any_template_arguments_need_structural_equality_p (tree);
195 static bool dependent_type_p_r (tree);
196 static tree tsubst_expr (tree, tree, tsubst_flags_t, tree, bool);
197 static tree tsubst_copy (tree, tree, tsubst_flags_t, tree);
198 static tree tsubst_pack_expansion (tree, tree, tsubst_flags_t, tree);
199 static tree tsubst_decl (tree, tree, tsubst_flags_t);
200 static void perform_typedefs_access_check (tree tmpl, tree targs);
201 static void append_type_to_template_for_access_check_1 (tree, tree, tree,
203 static tree listify (tree);
204 static tree listify_autos (tree, tree);
205 static tree template_parm_to_arg (tree t);
206 static bool arg_from_parm_pack_p (tree, tree);
207 static tree current_template_args (void);
208 static tree fixup_template_type_parm_type (tree, int);
209 static tree fixup_template_parm_index (tree, tree, int);
210 static tree tsubst_template_parm (tree, tree, tsubst_flags_t);
212 /* Make the current scope suitable for access checking when we are
213 processing T. T can be FUNCTION_DECL for instantiated function
214 template, or VAR_DECL for static member variable (need by
215 instantiate_decl). */
218 push_access_scope (tree t)
220 gcc_assert (TREE_CODE (t) == FUNCTION_DECL
221 || TREE_CODE (t) == VAR_DECL);
223 if (DECL_FRIEND_CONTEXT (t))
224 push_nested_class (DECL_FRIEND_CONTEXT (t));
225 else if (DECL_CLASS_SCOPE_P (t))
226 push_nested_class (DECL_CONTEXT (t));
228 push_to_top_level ();
230 if (TREE_CODE (t) == FUNCTION_DECL)
232 saved_access_scope = tree_cons
233 (NULL_TREE, current_function_decl, saved_access_scope);
234 current_function_decl = t;
238 /* Restore the scope set up by push_access_scope. T is the node we
242 pop_access_scope (tree t)
244 if (TREE_CODE (t) == FUNCTION_DECL)
246 current_function_decl = TREE_VALUE (saved_access_scope);
247 saved_access_scope = TREE_CHAIN (saved_access_scope);
250 if (DECL_FRIEND_CONTEXT (t) || DECL_CLASS_SCOPE_P (t))
253 pop_from_top_level ();
256 /* Do any processing required when DECL (a member template
257 declaration) is finished. Returns the TEMPLATE_DECL corresponding
258 to DECL, unless it is a specialization, in which case the DECL
259 itself is returned. */
262 finish_member_template_decl (tree decl)
264 if (decl == error_mark_node)
265 return error_mark_node;
267 gcc_assert (DECL_P (decl));
269 if (TREE_CODE (decl) == TYPE_DECL)
273 type = TREE_TYPE (decl);
274 if (type == error_mark_node)
275 return error_mark_node;
276 if (MAYBE_CLASS_TYPE_P (type)
277 && CLASSTYPE_TEMPLATE_INFO (type)
278 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
280 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
281 check_member_template (tmpl);
286 else if (TREE_CODE (decl) == FIELD_DECL)
287 error ("data member %qD cannot be a member template", decl);
288 else if (DECL_TEMPLATE_INFO (decl))
290 if (!DECL_TEMPLATE_SPECIALIZATION (decl))
292 check_member_template (DECL_TI_TEMPLATE (decl));
293 return DECL_TI_TEMPLATE (decl);
299 error ("invalid member template declaration %qD", decl);
301 return error_mark_node;
304 /* Create a template info node. */
307 build_template_info (tree template_decl, tree template_args)
309 tree result = make_node (TEMPLATE_INFO);
310 TI_TEMPLATE (result) = template_decl;
311 TI_ARGS (result) = template_args;
315 /* Return the template info node corresponding to T, whatever T is. */
318 get_template_info (const_tree t)
320 tree tinfo = NULL_TREE;
322 if (!t || t == error_mark_node)
325 if (DECL_P (t) && DECL_LANG_SPECIFIC (t))
326 tinfo = DECL_TEMPLATE_INFO (t);
328 if (!tinfo && DECL_IMPLICIT_TYPEDEF_P (t))
331 if (TAGGED_TYPE_P (t))
332 tinfo = TYPE_TEMPLATE_INFO (t);
333 else if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
334 tinfo = TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (t);
339 /* Returns the template nesting level of the indicated class TYPE.
349 A<T>::B<U> has depth two, while A<T> has depth one.
350 Both A<T>::B<int> and A<int>::B<U> have depth one, if
351 they are instantiations, not specializations.
353 This function is guaranteed to return 0 if passed NULL_TREE so
354 that, for example, `template_class_depth (current_class_type)' is
358 template_class_depth (tree type)
363 type && TREE_CODE (type) != NAMESPACE_DECL;
364 type = (TREE_CODE (type) == FUNCTION_DECL)
365 ? CP_DECL_CONTEXT (type) : CP_TYPE_CONTEXT (type))
367 tree tinfo = get_template_info (type);
369 if (tinfo && PRIMARY_TEMPLATE_P (TI_TEMPLATE (tinfo))
370 && uses_template_parms (INNERMOST_TEMPLATE_ARGS (TI_ARGS (tinfo))))
377 /* Subroutine of maybe_begin_member_template_processing.
378 Returns true if processing DECL needs us to push template parms. */
381 inline_needs_template_parms (tree decl)
383 if (! DECL_TEMPLATE_INFO (decl))
386 return (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (most_general_template (decl)))
387 > (processing_template_decl + DECL_TEMPLATE_SPECIALIZATION (decl)));
390 /* Subroutine of maybe_begin_member_template_processing.
391 Push the template parms in PARMS, starting from LEVELS steps into the
392 chain, and ending at the beginning, since template parms are listed
396 push_inline_template_parms_recursive (tree parmlist, int levels)
398 tree parms = TREE_VALUE (parmlist);
402 push_inline_template_parms_recursive (TREE_CHAIN (parmlist), levels - 1);
404 ++processing_template_decl;
405 current_template_parms
406 = tree_cons (size_int (processing_template_decl),
407 parms, current_template_parms);
408 TEMPLATE_PARMS_FOR_INLINE (current_template_parms) = 1;
410 begin_scope (TREE_VEC_LENGTH (parms) ? sk_template_parms : sk_template_spec,
412 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
414 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
416 if (parm == error_mark_node)
419 gcc_assert (DECL_P (parm));
421 switch (TREE_CODE (parm))
430 /* Make a CONST_DECL as is done in process_template_parm.
431 It is ugly that we recreate this here; the original
432 version built in process_template_parm is no longer
434 tree decl = build_decl (DECL_SOURCE_LOCATION (parm),
435 CONST_DECL, DECL_NAME (parm),
437 DECL_ARTIFICIAL (decl) = 1;
438 TREE_CONSTANT (decl) = 1;
439 TREE_READONLY (decl) = 1;
440 DECL_INITIAL (decl) = DECL_INITIAL (parm);
441 SET_DECL_TEMPLATE_PARM_P (decl);
452 /* Restore the template parameter context for a member template or
453 a friend template defined in a class definition. */
456 maybe_begin_member_template_processing (tree decl)
461 if (inline_needs_template_parms (decl))
463 parms = DECL_TEMPLATE_PARMS (most_general_template (decl));
464 levels = TMPL_PARMS_DEPTH (parms) - processing_template_decl;
466 if (DECL_TEMPLATE_SPECIALIZATION (decl))
469 parms = TREE_CHAIN (parms);
472 push_inline_template_parms_recursive (parms, levels);
475 /* Remember how many levels of template parameters we pushed so that
476 we can pop them later. */
477 VEC_safe_push (int, heap, inline_parm_levels, levels);
480 /* Undo the effects of maybe_begin_member_template_processing. */
483 maybe_end_member_template_processing (void)
488 if (VEC_length (int, inline_parm_levels) == 0)
491 last = VEC_pop (int, inline_parm_levels);
492 for (i = 0; i < last; ++i)
494 --processing_template_decl;
495 current_template_parms = TREE_CHAIN (current_template_parms);
500 /* Return a new template argument vector which contains all of ARGS,
501 but has as its innermost set of arguments the EXTRA_ARGS. */
504 add_to_template_args (tree args, tree extra_args)
511 if (args == NULL_TREE || extra_args == error_mark_node)
514 extra_depth = TMPL_ARGS_DEPTH (extra_args);
515 new_args = make_tree_vec (TMPL_ARGS_DEPTH (args) + extra_depth);
517 for (i = 1; i <= TMPL_ARGS_DEPTH (args); ++i)
518 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (args, i));
520 for (j = 1; j <= extra_depth; ++j, ++i)
521 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (extra_args, j));
526 /* Like add_to_template_args, but only the outermost ARGS are added to
527 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
528 (EXTRA_ARGS) levels are added. This function is used to combine
529 the template arguments from a partial instantiation with the
530 template arguments used to attain the full instantiation from the
531 partial instantiation. */
534 add_outermost_template_args (tree args, tree extra_args)
538 /* If there are more levels of EXTRA_ARGS than there are ARGS,
539 something very fishy is going on. */
540 gcc_assert (TMPL_ARGS_DEPTH (args) >= TMPL_ARGS_DEPTH (extra_args));
542 /* If *all* the new arguments will be the EXTRA_ARGS, just return
544 if (TMPL_ARGS_DEPTH (args) == TMPL_ARGS_DEPTH (extra_args))
547 /* For the moment, we make ARGS look like it contains fewer levels. */
548 TREE_VEC_LENGTH (args) -= TMPL_ARGS_DEPTH (extra_args);
550 new_args = add_to_template_args (args, extra_args);
552 /* Now, we restore ARGS to its full dimensions. */
553 TREE_VEC_LENGTH (args) += TMPL_ARGS_DEPTH (extra_args);
558 /* Return the N levels of innermost template arguments from the ARGS. */
561 get_innermost_template_args (tree args, int n)
569 /* If N is 1, just return the innermost set of template arguments. */
571 return TMPL_ARGS_LEVEL (args, TMPL_ARGS_DEPTH (args));
573 /* If we're not removing anything, just return the arguments we were
575 extra_levels = TMPL_ARGS_DEPTH (args) - n;
576 gcc_assert (extra_levels >= 0);
577 if (extra_levels == 0)
580 /* Make a new set of arguments, not containing the outer arguments. */
581 new_args = make_tree_vec (n);
582 for (i = 1; i <= n; ++i)
583 SET_TMPL_ARGS_LEVEL (new_args, i,
584 TMPL_ARGS_LEVEL (args, i + extra_levels));
589 /* The inverse of get_innermost_template_args: Return all but the innermost
590 EXTRA_LEVELS levels of template arguments from the ARGS. */
593 strip_innermost_template_args (tree args, int extra_levels)
596 int n = TMPL_ARGS_DEPTH (args) - extra_levels;
601 /* If N is 1, just return the outermost set of template arguments. */
603 return TMPL_ARGS_LEVEL (args, 1);
605 /* If we're not removing anything, just return the arguments we were
607 gcc_assert (extra_levels >= 0);
608 if (extra_levels == 0)
611 /* Make a new set of arguments, not containing the inner arguments. */
612 new_args = make_tree_vec (n);
613 for (i = 1; i <= n; ++i)
614 SET_TMPL_ARGS_LEVEL (new_args, i,
615 TMPL_ARGS_LEVEL (args, i));
620 /* We've got a template header coming up; push to a new level for storing
624 begin_template_parm_list (void)
626 /* We use a non-tag-transparent scope here, which causes pushtag to
627 put tags in this scope, rather than in the enclosing class or
628 namespace scope. This is the right thing, since we want
629 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
630 global template class, push_template_decl handles putting the
631 TEMPLATE_DECL into top-level scope. For a nested template class,
634 template <class T> struct S1 {
635 template <class T> struct S2 {};
638 pushtag contains special code to call pushdecl_with_scope on the
639 TEMPLATE_DECL for S2. */
640 begin_scope (sk_template_parms, NULL);
641 ++processing_template_decl;
642 ++processing_template_parmlist;
643 note_template_header (0);
646 /* This routine is called when a specialization is declared. If it is
647 invalid to declare a specialization here, an error is reported and
648 false is returned, otherwise this routine will return true. */
651 check_specialization_scope (void)
653 tree scope = current_scope ();
657 An explicit specialization shall be declared in the namespace of
658 which the template is a member, or, for member templates, in the
659 namespace of which the enclosing class or enclosing class
660 template is a member. An explicit specialization of a member
661 function, member class or static data member of a class template
662 shall be declared in the namespace of which the class template
664 if (scope && TREE_CODE (scope) != NAMESPACE_DECL)
666 error ("explicit specialization in non-namespace scope %qD", scope);
672 In an explicit specialization declaration for a member of a class
673 template or a member template that appears in namespace scope,
674 the member template and some of its enclosing class templates may
675 remain unspecialized, except that the declaration shall not
676 explicitly specialize a class member template if its enclosing
677 class templates are not explicitly specialized as well. */
678 if (current_template_parms)
680 error ("enclosing class templates are not explicitly specialized");
687 /* We've just seen template <>. */
690 begin_specialization (void)
692 begin_scope (sk_template_spec, NULL);
693 note_template_header (1);
694 return check_specialization_scope ();
697 /* Called at then end of processing a declaration preceded by
701 end_specialization (void)
704 reset_specialization ();
707 /* Any template <>'s that we have seen thus far are not referring to a
708 function specialization. */
711 reset_specialization (void)
713 processing_specialization = 0;
714 template_header_count = 0;
717 /* We've just seen a template header. If SPECIALIZATION is nonzero,
718 it was of the form template <>. */
721 note_template_header (int specialization)
723 processing_specialization = specialization;
724 template_header_count++;
727 /* We're beginning an explicit instantiation. */
730 begin_explicit_instantiation (void)
732 gcc_assert (!processing_explicit_instantiation);
733 processing_explicit_instantiation = true;
738 end_explicit_instantiation (void)
740 gcc_assert (processing_explicit_instantiation);
741 processing_explicit_instantiation = false;
744 /* An explicit specialization or partial specialization TMPL is being
745 declared. Check that the namespace in which the specialization is
746 occurring is permissible. Returns false iff it is invalid to
747 specialize TMPL in the current namespace. */
750 check_specialization_namespace (tree tmpl)
752 tree tpl_ns = decl_namespace_context (tmpl);
756 An explicit specialization shall be declared in the namespace of
757 which the template is a member, or, for member templates, in the
758 namespace of which the enclosing class or enclosing class
759 template is a member. An explicit specialization of a member
760 function, member class or static data member of a class template
761 shall be declared in the namespace of which the class template is
763 if (current_scope() != DECL_CONTEXT (tmpl)
764 && !at_namespace_scope_p ())
766 error ("specialization of %qD must appear at namespace scope", tmpl);
769 if (is_associated_namespace (current_namespace, tpl_ns))
770 /* Same or super-using namespace. */
774 permerror (input_location, "specialization of %qD in different namespace", tmpl);
775 permerror (input_location, " from definition of %q+#D", tmpl);
780 /* SPEC is an explicit instantiation. Check that it is valid to
781 perform this explicit instantiation in the current namespace. */
784 check_explicit_instantiation_namespace (tree spec)
788 /* DR 275: An explicit instantiation shall appear in an enclosing
789 namespace of its template. */
790 ns = decl_namespace_context (spec);
791 if (!is_ancestor (current_namespace, ns))
792 permerror (input_location, "explicit instantiation of %qD in namespace %qD "
793 "(which does not enclose namespace %qD)",
794 spec, current_namespace, ns);
797 /* The TYPE is being declared. If it is a template type, that means it
798 is a partial specialization. Do appropriate error-checking. */
801 maybe_process_partial_specialization (tree type)
805 if (type == error_mark_node)
806 return error_mark_node;
808 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
810 error ("name of class shadows template template parameter %qD",
812 return error_mark_node;
815 context = TYPE_CONTEXT (type);
817 if ((CLASS_TYPE_P (type) && CLASSTYPE_USE_TEMPLATE (type))
818 /* Consider non-class instantiations of alias templates as
821 && TYPE_TEMPLATE_INFO (type)
822 && DECL_LANG_SPECIFIC (TYPE_NAME (type))
823 && DECL_USE_TEMPLATE (TYPE_NAME (type))))
825 /* This is for ordinary explicit specialization and partial
826 specialization of a template class such as:
828 template <> class C<int>;
832 template <class T> class C<T*>;
834 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
836 if (CLASS_TYPE_P (type)
837 && CLASSTYPE_IMPLICIT_INSTANTIATION (type)
838 && !COMPLETE_TYPE_P (type))
840 check_specialization_namespace (CLASSTYPE_TI_TEMPLATE (type));
841 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
842 if (processing_template_decl)
844 if (push_template_decl (TYPE_MAIN_DECL (type))
846 return error_mark_node;
849 else if (CLASS_TYPE_P (type)
850 && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
851 error ("specialization of %qT after instantiation", type);
853 if (DECL_ALIAS_TEMPLATE_P (TYPE_TI_TEMPLATE (type)))
855 error ("partial specialization of alias template %qD",
856 TYPE_TI_TEMPLATE (type));
857 return error_mark_node;
860 else if (CLASS_TYPE_P (type)
861 && !CLASSTYPE_USE_TEMPLATE (type)
862 && CLASSTYPE_TEMPLATE_INFO (type)
863 && context && CLASS_TYPE_P (context)
864 && CLASSTYPE_TEMPLATE_INFO (context))
866 /* This is for an explicit specialization of member class
867 template according to [temp.expl.spec/18]:
869 template <> template <class U> class C<int>::D;
871 The context `C<int>' must be an implicit instantiation.
872 Otherwise this is just a member class template declared
875 template <> class C<int> { template <class U> class D; };
876 template <> template <class U> class C<int>::D;
878 In the first case, `C<int>::D' is a specialization of `C<T>::D'
879 while in the second case, `C<int>::D' is a primary template
880 and `C<T>::D' may not exist. */
882 if (CLASSTYPE_IMPLICIT_INSTANTIATION (context)
883 && !COMPLETE_TYPE_P (type))
886 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
888 if (current_namespace
889 != decl_namespace_context (tmpl))
891 permerror (input_location, "specializing %q#T in different namespace", type);
892 permerror (input_location, " from definition of %q+#D", tmpl);
895 /* Check for invalid specialization after instantiation:
897 template <> template <> class C<int>::D<int>;
898 template <> template <class U> class C<int>::D; */
900 for (t = DECL_TEMPLATE_INSTANTIATIONS (tmpl);
901 t; t = TREE_CHAIN (t))
903 tree inst = TREE_VALUE (t);
904 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (inst))
906 /* We already have a full specialization of this partial
907 instantiation. Reassign it to the new member
908 specialization template. */
913 elt.tmpl = most_general_template (tmpl);
914 elt.args = CLASSTYPE_TI_ARGS (inst);
917 htab_remove_elt (type_specializations, &elt);
920 elt.args = INNERMOST_TEMPLATE_ARGS (elt.args);
922 slot = htab_find_slot (type_specializations, &elt, INSERT);
923 entry = ggc_alloc_spec_entry ();
927 else if (COMPLETE_OR_OPEN_TYPE_P (inst))
928 /* But if we've had an implicit instantiation, that's a
929 problem ([temp.expl.spec]/6). */
930 error ("specialization %qT after instantiation %qT",
934 /* Mark TYPE as a specialization. And as a result, we only
935 have one level of template argument for the innermost
937 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
938 CLASSTYPE_TI_ARGS (type)
939 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type));
942 else if (processing_specialization)
944 /* Someday C++0x may allow for enum template specialization. */
945 if (cxx_dialect > cxx98 && TREE_CODE (type) == ENUMERAL_TYPE
946 && CLASS_TYPE_P (context) && CLASSTYPE_USE_TEMPLATE (context))
947 pedwarn (input_location, OPT_pedantic, "template specialization "
948 "of %qD not allowed by ISO C++", type);
951 error ("explicit specialization of non-template %qT", type);
952 return error_mark_node;
959 /* Returns nonzero if we can optimize the retrieval of specializations
960 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
961 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
964 optimize_specialization_lookup_p (tree tmpl)
966 return (DECL_FUNCTION_TEMPLATE_P (tmpl)
967 && DECL_CLASS_SCOPE_P (tmpl)
968 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
970 && CLASS_TYPE_P (DECL_CONTEXT (tmpl))
971 /* The optimized lookup depends on the fact that the
972 template arguments for the member function template apply
973 purely to the containing class, which is not true if the
974 containing class is an explicit or partial
976 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (tmpl))
977 && !DECL_MEMBER_TEMPLATE_P (tmpl)
978 && !DECL_CONV_FN_P (tmpl)
979 /* It is possible to have a template that is not a member
980 template and is not a member of a template class:
982 template <typename T>
983 struct S { friend A::f(); };
985 Here, the friend function is a template, but the context does
986 not have template information. The optimized lookup relies
987 on having ARGS be the template arguments for both the class
988 and the function template. */
989 && !DECL_FRIEND_P (DECL_TEMPLATE_RESULT (tmpl)));
992 /* Retrieve the specialization (in the sense of [temp.spec] - a
993 specialization is either an instantiation or an explicit
994 specialization) of TMPL for the given template ARGS. If there is
995 no such specialization, return NULL_TREE. The ARGS are a vector of
996 arguments, or a vector of vectors of arguments, in the case of
997 templates with more than one level of parameters.
999 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
1000 then we search for a partial specialization matching ARGS. This
1001 parameter is ignored if TMPL is not a class template. */
1004 retrieve_specialization (tree tmpl, tree args, hashval_t hash)
1006 if (args == error_mark_node)
1009 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
1011 /* There should be as many levels of arguments as there are
1012 levels of parameters. */
1013 gcc_assert (TMPL_ARGS_DEPTH (args)
1014 == TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl)));
1016 if (optimize_specialization_lookup_p (tmpl))
1018 tree class_template;
1019 tree class_specialization;
1020 VEC(tree,gc) *methods;
1024 /* The template arguments actually apply to the containing
1025 class. Find the class specialization with those
1027 class_template = CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (tmpl));
1028 class_specialization
1029 = retrieve_specialization (class_template, args, 0);
1030 if (!class_specialization)
1032 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
1033 for the specialization. */
1034 idx = class_method_index_for_fn (class_specialization, tmpl);
1037 /* Iterate through the methods with the indicated name, looking
1038 for the one that has an instance of TMPL. */
1039 methods = CLASSTYPE_METHOD_VEC (class_specialization);
1040 for (fns = VEC_index (tree, methods, idx); fns; fns = OVL_NEXT (fns))
1042 tree fn = OVL_CURRENT (fns);
1043 if (DECL_TEMPLATE_INFO (fn) && DECL_TI_TEMPLATE (fn) == tmpl
1044 /* using-declarations can add base methods to the method vec,
1045 and we don't want those here. */
1046 && DECL_CONTEXT (fn) == class_specialization)
1055 htab_t specializations;
1059 elt.spec = NULL_TREE;
1061 if (DECL_CLASS_TEMPLATE_P (tmpl))
1062 specializations = type_specializations;
1064 specializations = decl_specializations;
1067 hash = hash_specialization (&elt);
1068 found = (spec_entry *) htab_find_with_hash (specializations, &elt, hash);
1076 /* Like retrieve_specialization, but for local declarations. */
1079 retrieve_local_specialization (tree tmpl)
1083 if (local_specializations == NULL)
1086 spec = (tree) htab_find_with_hash (local_specializations, tmpl,
1087 htab_hash_pointer (tmpl));
1088 return spec ? TREE_PURPOSE (spec) : NULL_TREE;
1091 /* Returns nonzero iff DECL is a specialization of TMPL. */
1094 is_specialization_of (tree decl, tree tmpl)
1098 if (TREE_CODE (decl) == FUNCTION_DECL)
1102 t = DECL_TEMPLATE_INFO (t) ? DECL_TI_TEMPLATE (t) : NULL_TREE)
1108 gcc_assert (TREE_CODE (decl) == TYPE_DECL);
1110 for (t = TREE_TYPE (decl);
1112 t = CLASSTYPE_USE_TEMPLATE (t)
1113 ? TREE_TYPE (CLASSTYPE_TI_TEMPLATE (t)) : NULL_TREE)
1114 if (same_type_ignoring_top_level_qualifiers_p (t, TREE_TYPE (tmpl)))
1121 /* Returns nonzero iff DECL is a specialization of friend declaration
1122 FRIEND_DECL according to [temp.friend]. */
1125 is_specialization_of_friend (tree decl, tree friend_decl)
1127 bool need_template = true;
1130 gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
1131 || TREE_CODE (decl) == TYPE_DECL);
1133 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1134 of a template class, we want to check if DECL is a specialization
1136 if (TREE_CODE (friend_decl) == FUNCTION_DECL
1137 && DECL_TEMPLATE_INFO (friend_decl)
1138 && !DECL_USE_TEMPLATE (friend_decl))
1140 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1141 friend_decl = DECL_TI_TEMPLATE (friend_decl);
1142 need_template = false;
1144 else if (TREE_CODE (friend_decl) == TEMPLATE_DECL
1145 && !PRIMARY_TEMPLATE_P (friend_decl))
1146 need_template = false;
1148 /* There is nothing to do if this is not a template friend. */
1149 if (TREE_CODE (friend_decl) != TEMPLATE_DECL)
1152 if (is_specialization_of (decl, friend_decl))
1156 A member of a class template may be declared to be a friend of a
1157 non-template class. In this case, the corresponding member of
1158 every specialization of the class template is a friend of the
1159 class granting friendship.
1161 For example, given a template friend declaration
1163 template <class T> friend void A<T>::f();
1165 the member function below is considered a friend
1167 template <> struct A<int> {
1171 For this type of template friend, TEMPLATE_DEPTH below will be
1172 nonzero. To determine if DECL is a friend of FRIEND, we first
1173 check if the enclosing class is a specialization of another. */
1175 template_depth = template_class_depth (CP_DECL_CONTEXT (friend_decl));
1177 && DECL_CLASS_SCOPE_P (decl)
1178 && is_specialization_of (TYPE_NAME (DECL_CONTEXT (decl)),
1179 CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (friend_decl))))
1181 /* Next, we check the members themselves. In order to handle
1182 a few tricky cases, such as when FRIEND_DECL's are
1184 template <class T> friend void A<T>::g(T t);
1185 template <class T> template <T t> friend void A<T>::h();
1189 void A<int>::g(int);
1190 template <int> void A<int>::h();
1192 we need to figure out ARGS, the template arguments from
1193 the context of DECL. This is required for template substitution
1194 of `T' in the function parameter of `g' and template parameter
1195 of `h' in the above examples. Here ARGS corresponds to `int'. */
1197 tree context = DECL_CONTEXT (decl);
1198 tree args = NULL_TREE;
1199 int current_depth = 0;
1201 while (current_depth < template_depth)
1203 if (CLASSTYPE_TEMPLATE_INFO (context))
1205 if (current_depth == 0)
1206 args = TYPE_TI_ARGS (context);
1208 args = add_to_template_args (TYPE_TI_ARGS (context), args);
1211 context = TYPE_CONTEXT (context);
1214 if (TREE_CODE (decl) == FUNCTION_DECL)
1219 tree friend_args_type;
1220 tree decl_args_type;
1222 /* Make sure that both DECL and FRIEND_DECL are templates or
1224 is_template = DECL_TEMPLATE_INFO (decl)
1225 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (decl));
1226 if (need_template ^ is_template)
1228 else if (is_template)
1230 /* If both are templates, check template parameter list. */
1232 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1234 if (!comp_template_parms
1235 (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (decl)),
1239 decl_type = TREE_TYPE (DECL_TI_TEMPLATE (decl));
1242 decl_type = TREE_TYPE (decl);
1244 friend_type = tsubst_function_type (TREE_TYPE (friend_decl), args,
1245 tf_none, NULL_TREE);
1246 if (friend_type == error_mark_node)
1249 /* Check if return types match. */
1250 if (!same_type_p (TREE_TYPE (decl_type), TREE_TYPE (friend_type)))
1253 /* Check if function parameter types match, ignoring the
1254 `this' parameter. */
1255 friend_args_type = TYPE_ARG_TYPES (friend_type);
1256 decl_args_type = TYPE_ARG_TYPES (decl_type);
1257 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (friend_decl))
1258 friend_args_type = TREE_CHAIN (friend_args_type);
1259 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1260 decl_args_type = TREE_CHAIN (decl_args_type);
1262 return compparms (decl_args_type, friend_args_type);
1266 /* DECL is a TYPE_DECL */
1268 tree decl_type = TREE_TYPE (decl);
1270 /* Make sure that both DECL and FRIEND_DECL are templates or
1273 = CLASSTYPE_TEMPLATE_INFO (decl_type)
1274 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (decl_type));
1276 if (need_template ^ is_template)
1278 else if (is_template)
1281 /* If both are templates, check the name of the two
1282 TEMPLATE_DECL's first because is_friend didn't. */
1283 if (DECL_NAME (CLASSTYPE_TI_TEMPLATE (decl_type))
1284 != DECL_NAME (friend_decl))
1287 /* Now check template parameter list. */
1289 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1291 return comp_template_parms
1292 (DECL_TEMPLATE_PARMS (CLASSTYPE_TI_TEMPLATE (decl_type)),
1296 return (DECL_NAME (decl)
1297 == DECL_NAME (friend_decl));
1303 /* Register the specialization SPEC as a specialization of TMPL with
1304 the indicated ARGS. IS_FRIEND indicates whether the specialization
1305 is actually just a friend declaration. Returns SPEC, or an
1306 equivalent prior declaration, if available. */
1309 register_specialization (tree spec, tree tmpl, tree args, bool is_friend,
1316 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL && DECL_P (spec));
1318 if (TREE_CODE (spec) == FUNCTION_DECL
1319 && uses_template_parms (DECL_TI_ARGS (spec)))
1320 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1321 register it; we want the corresponding TEMPLATE_DECL instead.
1322 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1323 the more obvious `uses_template_parms (spec)' to avoid problems
1324 with default function arguments. In particular, given
1325 something like this:
1327 template <class T> void f(T t1, T t = T())
1329 the default argument expression is not substituted for in an
1330 instantiation unless and until it is actually needed. */
1333 if (optimize_specialization_lookup_p (tmpl))
1334 /* We don't put these specializations in the hash table, but we might
1335 want to give an error about a mismatch. */
1336 fn = retrieve_specialization (tmpl, args, 0);
1344 hash = hash_specialization (&elt);
1347 htab_find_slot_with_hash (decl_specializations, &elt, hash, INSERT);
1349 fn = ((spec_entry *) *slot)->spec;
1354 /* We can sometimes try to re-register a specialization that we've
1355 already got. In particular, regenerate_decl_from_template calls
1356 duplicate_decls which will update the specialization list. But,
1357 we'll still get called again here anyhow. It's more convenient
1358 to simply allow this than to try to prevent it. */
1361 else if (fn && DECL_TEMPLATE_SPECIALIZATION (spec))
1363 if (DECL_TEMPLATE_INSTANTIATION (fn))
1365 if (DECL_ODR_USED (fn)
1366 || DECL_EXPLICIT_INSTANTIATION (fn))
1368 error ("specialization of %qD after instantiation",
1370 return error_mark_node;
1375 /* This situation should occur only if the first
1376 specialization is an implicit instantiation, the
1377 second is an explicit specialization, and the
1378 implicit instantiation has not yet been used. That
1379 situation can occur if we have implicitly
1380 instantiated a member function and then specialized
1383 We can also wind up here if a friend declaration that
1384 looked like an instantiation turns out to be a
1387 template <class T> void foo(T);
1388 class S { friend void foo<>(int) };
1389 template <> void foo(int);
1391 We transform the existing DECL in place so that any
1392 pointers to it become pointers to the updated
1395 If there was a definition for the template, but not
1396 for the specialization, we want this to look as if
1397 there were no definition, and vice versa. */
1398 DECL_INITIAL (fn) = NULL_TREE;
1399 duplicate_decls (spec, fn, is_friend);
1400 /* The call to duplicate_decls will have applied
1403 An explicit specialization of a function template
1404 is inline only if it is explicitly declared to be,
1405 and independently of whether its function template
1408 to the primary function; now copy the inline bits to
1409 the various clones. */
1410 FOR_EACH_CLONE (clone, fn)
1412 DECL_DECLARED_INLINE_P (clone)
1413 = DECL_DECLARED_INLINE_P (fn);
1414 DECL_SOURCE_LOCATION (clone)
1415 = DECL_SOURCE_LOCATION (fn);
1417 check_specialization_namespace (fn);
1422 else if (DECL_TEMPLATE_SPECIALIZATION (fn))
1424 if (!duplicate_decls (spec, fn, is_friend) && DECL_INITIAL (spec))
1425 /* Dup decl failed, but this is a new definition. Set the
1426 line number so any errors match this new
1428 DECL_SOURCE_LOCATION (fn) = DECL_SOURCE_LOCATION (spec);
1434 return duplicate_decls (spec, fn, is_friend);
1436 /* A specialization must be declared in the same namespace as the
1437 template it is specializing. */
1438 if (DECL_TEMPLATE_SPECIALIZATION (spec)
1439 && !check_specialization_namespace (tmpl))
1440 DECL_CONTEXT (spec) = DECL_CONTEXT (tmpl);
1442 if (slot != NULL /* !optimize_specialization_lookup_p (tmpl) */)
1444 spec_entry *entry = ggc_alloc_spec_entry ();
1445 gcc_assert (tmpl && args && spec);
1448 if (TREE_CODE (spec) == FUNCTION_DECL && DECL_NAMESPACE_SCOPE_P (spec)
1449 && PRIMARY_TEMPLATE_P (tmpl)
1450 && DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (tmpl)) == NULL_TREE)
1451 /* TMPL is a forward declaration of a template function; keep a list
1452 of all specializations in case we need to reassign them to a friend
1453 template later in tsubst_friend_function. */
1454 DECL_TEMPLATE_INSTANTIATIONS (tmpl)
1455 = tree_cons (args, spec, DECL_TEMPLATE_INSTANTIATIONS (tmpl));
1461 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1462 TMPL and ARGS members, ignores SPEC. */
1465 eq_specializations (const void *p1, const void *p2)
1467 const spec_entry *e1 = (const spec_entry *)p1;
1468 const spec_entry *e2 = (const spec_entry *)p2;
1470 return (e1->tmpl == e2->tmpl
1471 && comp_template_args (e1->args, e2->args));
1474 /* Returns a hash for a template TMPL and template arguments ARGS. */
1477 hash_tmpl_and_args (tree tmpl, tree args)
1479 hashval_t val = DECL_UID (tmpl);
1480 return iterative_hash_template_arg (args, val);
1483 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1487 hash_specialization (const void *p)
1489 const spec_entry *e = (const spec_entry *)p;
1490 return hash_tmpl_and_args (e->tmpl, e->args);
1493 /* Recursively calculate a hash value for a template argument ARG, for use
1494 in the hash tables of template specializations. */
1497 iterative_hash_template_arg (tree arg, hashval_t val)
1499 unsigned HOST_WIDE_INT i;
1500 enum tree_code code;
1503 if (arg == NULL_TREE)
1504 return iterative_hash_object (arg, val);
1509 if (TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
1510 /* We can get one of these when re-hashing a previous entry in the middle
1511 of substituting into a pack expansion. Just look through it. */
1512 arg = ARGUMENT_PACK_SELECT_FROM_PACK (arg);
1514 code = TREE_CODE (arg);
1515 tclass = TREE_CODE_CLASS (code);
1517 val = iterative_hash_object (code, val);
1524 case IDENTIFIER_NODE:
1525 return iterative_hash_object (IDENTIFIER_HASH_VALUE (arg), val);
1529 int i, len = TREE_VEC_LENGTH (arg);
1530 for (i = 0; i < len; ++i)
1531 val = iterative_hash_template_arg (TREE_VEC_ELT (arg, i), val);
1535 case TYPE_PACK_EXPANSION:
1536 case EXPR_PACK_EXPANSION:
1537 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;
1864 /* In case of explicit specialization, we need to check if
1865 the number of template headers appearing in the specialization
1866 is correct. This is usually done in check_explicit_specialization,
1867 but the check done there cannot be exhaustive when specializing
1868 member functions. Consider the following code:
1870 template <> void A<int>::f(int);
1871 template <> template <> void A<int>::f(int);
1873 Assuming that A<int> is not itself an explicit specialization
1874 already, the first line specializes "f" which is a non-template
1875 member function, whilst the second line specializes "f" which
1876 is a template member function. So both lines are syntactically
1877 correct, and check_explicit_specialization does not reject
1880 Here, we can do better, as we are matching the specialization
1881 against the declarations. We count the number of template
1882 headers, and we check if they match TEMPLATE_COUNT + 1
1883 (TEMPLATE_COUNT is the number of qualifying template classes,
1884 plus there must be another header for the member template
1887 Notice that if header_count is zero, this is not a
1888 specialization but rather a template instantiation, so there
1889 is no check we can perform here. */
1890 if (header_count && header_count != template_count + 1)
1893 /* Check that the number of template arguments at the
1894 innermost level for DECL is the same as for FN. */
1895 if (current_binding_level->kind == sk_template_parms
1896 && !current_binding_level->explicit_spec_p
1897 && (TREE_VEC_LENGTH (DECL_INNERMOST_TEMPLATE_PARMS (fn))
1898 != TREE_VEC_LENGTH (INNERMOST_TEMPLATE_PARMS
1899 (current_template_parms))))
1902 /* DECL might be a specialization of FN. */
1903 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1904 fn_arg_types = TYPE_ARG_TYPES (TREE_TYPE (fn));
1906 /* For a non-static member function, we need to make sure
1907 that the const qualification is the same. Since
1908 get_bindings does not try to merge the "this" parameter,
1909 we must do the comparison explicitly. */
1910 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
1911 && !same_type_p (TREE_VALUE (fn_arg_types),
1912 TREE_VALUE (decl_arg_types)))
1915 /* Skip the "this" parameter and, for constructors of
1916 classes with virtual bases, the VTT parameter. A
1917 full specialization of a constructor will have a VTT
1918 parameter, but a template never will. */
1920 = skip_artificial_parms_for (decl, decl_arg_types);
1922 = skip_artificial_parms_for (fn, fn_arg_types);
1924 /* Check that the number of function parameters matches.
1926 template <class T> void f(int i = 0);
1927 template <> void f<int>();
1928 The specialization f<int> is invalid but is not caught
1929 by get_bindings below. */
1930 if (list_length (fn_arg_types) != list_length (decl_arg_types))
1933 /* Function templates cannot be specializations; there are
1934 no partial specializations of functions. Therefore, if
1935 the type of DECL does not match FN, there is no
1937 if (tsk == tsk_template)
1939 if (compparms (fn_arg_types, decl_arg_types))
1940 candidates = tree_cons (NULL_TREE, fn, candidates);
1944 /* See whether this function might be a specialization of this
1946 targs = get_bindings (fn, decl, explicit_targs, /*check_ret=*/true);
1949 /* We cannot deduce template arguments that when used to
1950 specialize TMPL will produce DECL. */
1953 /* Save this template, and the arguments deduced. */
1954 templates = tree_cons (targs, fn, templates);
1956 else if (need_member_template)
1957 /* FN is an ordinary member function, and we need a
1958 specialization of a member template. */
1960 else if (TREE_CODE (fn) != FUNCTION_DECL)
1961 /* We can get IDENTIFIER_NODEs here in certain erroneous
1964 else if (!DECL_FUNCTION_MEMBER_P (fn))
1965 /* This is just an ordinary non-member function. Nothing can
1966 be a specialization of that. */
1968 else if (DECL_ARTIFICIAL (fn))
1969 /* Cannot specialize functions that are created implicitly. */
1973 tree decl_arg_types;
1975 /* This is an ordinary member function. However, since
1976 we're here, we can assume it's enclosing class is a
1977 template class. For example,
1979 template <typename T> struct S { void f(); };
1980 template <> void S<int>::f() {}
1982 Here, S<int>::f is a non-template, but S<int> is a
1983 template class. If FN has the same type as DECL, we
1984 might be in business. */
1986 if (!DECL_TEMPLATE_INFO (fn))
1987 /* Its enclosing class is an explicit specialization
1988 of a template class. This is not a candidate. */
1991 if (!same_type_p (TREE_TYPE (TREE_TYPE (decl)),
1992 TREE_TYPE (TREE_TYPE (fn))))
1993 /* The return types differ. */
1996 /* Adjust the type of DECL in case FN is a static member. */
1997 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1998 if (DECL_STATIC_FUNCTION_P (fn)
1999 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2000 decl_arg_types = TREE_CHAIN (decl_arg_types);
2002 if (compparms (TYPE_ARG_TYPES (TREE_TYPE (fn)),
2005 candidates = tree_cons (NULL_TREE, fn, candidates);
2009 if (templates && TREE_CHAIN (templates))
2015 It is possible for a specialization with a given function
2016 signature to be instantiated from more than one function
2017 template. In such cases, explicit specification of the
2018 template arguments must be used to uniquely identify the
2019 function template specialization being specialized.
2021 Note that here, there's no suggestion that we're supposed to
2022 determine which of the candidate templates is most
2023 specialized. However, we, also have:
2027 Partial ordering of overloaded function template
2028 declarations is used in the following contexts to select
2029 the function template to which a function template
2030 specialization refers:
2032 -- when an explicit specialization refers to a function
2035 So, we do use the partial ordering rules, at least for now.
2036 This extension can only serve to make invalid programs valid,
2037 so it's safe. And, there is strong anecdotal evidence that
2038 the committee intended the partial ordering rules to apply;
2039 the EDG front end has that behavior, and John Spicer claims
2040 that the committee simply forgot to delete the wording in
2041 [temp.expl.spec]. */
2042 tree tmpl = most_specialized_instantiation (templates);
2043 if (tmpl != error_mark_node)
2046 TREE_CHAIN (templates) = NULL_TREE;
2050 if (templates == NULL_TREE && candidates == NULL_TREE)
2052 error ("template-id %qD for %q+D does not match any template "
2053 "declaration", template_id, decl);
2054 if (header_count && header_count != template_count + 1)
2055 inform (input_location, "saw %d %<template<>%>, need %d for "
2056 "specializing a member function template",
2057 header_count, template_count + 1);
2058 return error_mark_node;
2060 else if ((templates && TREE_CHAIN (templates))
2061 || (candidates && TREE_CHAIN (candidates))
2062 || (templates && candidates))
2064 error ("ambiguous template specialization %qD for %q+D",
2066 candidates = chainon (candidates, templates);
2067 print_candidates (candidates);
2068 return error_mark_node;
2071 /* We have one, and exactly one, match. */
2074 tree fn = TREE_VALUE (candidates);
2075 *targs_out = copy_node (DECL_TI_ARGS (fn));
2076 /* DECL is a re-declaration or partial instantiation of a template
2078 if (TREE_CODE (fn) == TEMPLATE_DECL)
2080 /* It was a specialization of an ordinary member function in a
2082 return DECL_TI_TEMPLATE (fn);
2085 /* It was a specialization of a template. */
2086 targs = DECL_TI_ARGS (DECL_TEMPLATE_RESULT (TREE_VALUE (templates)));
2087 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (targs))
2089 *targs_out = copy_node (targs);
2090 SET_TMPL_ARGS_LEVEL (*targs_out,
2091 TMPL_ARGS_DEPTH (*targs_out),
2092 TREE_PURPOSE (templates));
2095 *targs_out = TREE_PURPOSE (templates);
2096 return TREE_VALUE (templates);
2099 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2100 but with the default argument values filled in from those in the
2104 copy_default_args_to_explicit_spec_1 (tree spec_types,
2107 tree new_spec_types;
2112 if (spec_types == void_list_node)
2113 return void_list_node;
2115 /* Substitute into the rest of the list. */
2117 copy_default_args_to_explicit_spec_1 (TREE_CHAIN (spec_types),
2118 TREE_CHAIN (tmpl_types));
2120 /* Add the default argument for this parameter. */
2121 return hash_tree_cons (TREE_PURPOSE (tmpl_types),
2122 TREE_VALUE (spec_types),
2126 /* DECL is an explicit specialization. Replicate default arguments
2127 from the template it specializes. (That way, code like:
2129 template <class T> void f(T = 3);
2130 template <> void f(double);
2133 works, as required.) An alternative approach would be to look up
2134 the correct default arguments at the call-site, but this approach
2135 is consistent with how implicit instantiations are handled. */
2138 copy_default_args_to_explicit_spec (tree decl)
2143 tree new_spec_types;
2147 tree object_type = NULL_TREE;
2148 tree in_charge = NULL_TREE;
2149 tree vtt = NULL_TREE;
2151 /* See if there's anything we need to do. */
2152 tmpl = DECL_TI_TEMPLATE (decl);
2153 tmpl_types = TYPE_ARG_TYPES (TREE_TYPE (DECL_TEMPLATE_RESULT (tmpl)));
2154 for (t = tmpl_types; t; t = TREE_CHAIN (t))
2155 if (TREE_PURPOSE (t))
2160 old_type = TREE_TYPE (decl);
2161 spec_types = TYPE_ARG_TYPES (old_type);
2163 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2165 /* Remove the this pointer, but remember the object's type for
2167 object_type = TREE_TYPE (TREE_VALUE (spec_types));
2168 spec_types = TREE_CHAIN (spec_types);
2169 tmpl_types = TREE_CHAIN (tmpl_types);
2171 if (DECL_HAS_IN_CHARGE_PARM_P (decl))
2173 /* DECL may contain more parameters than TMPL due to the extra
2174 in-charge parameter in constructors and destructors. */
2175 in_charge = spec_types;
2176 spec_types = TREE_CHAIN (spec_types);
2178 if (DECL_HAS_VTT_PARM_P (decl))
2181 spec_types = TREE_CHAIN (spec_types);
2185 /* Compute the merged default arguments. */
2187 copy_default_args_to_explicit_spec_1 (spec_types, tmpl_types);
2189 /* Compute the new FUNCTION_TYPE. */
2193 new_spec_types = hash_tree_cons (TREE_PURPOSE (vtt),
2198 /* Put the in-charge parameter back. */
2199 new_spec_types = hash_tree_cons (TREE_PURPOSE (in_charge),
2200 TREE_VALUE (in_charge),
2203 new_type = build_method_type_directly (object_type,
2204 TREE_TYPE (old_type),
2208 new_type = build_function_type (TREE_TYPE (old_type),
2210 new_type = cp_build_type_attribute_variant (new_type,
2211 TYPE_ATTRIBUTES (old_type));
2212 new_type = build_exception_variant (new_type,
2213 TYPE_RAISES_EXCEPTIONS (old_type));
2214 TREE_TYPE (decl) = new_type;
2217 /* Check to see if the function just declared, as indicated in
2218 DECLARATOR, and in DECL, is a specialization of a function
2219 template. We may also discover that the declaration is an explicit
2220 instantiation at this point.
2222 Returns DECL, or an equivalent declaration that should be used
2223 instead if all goes well. Issues an error message if something is
2224 amiss. Returns error_mark_node if the error is not easily
2227 FLAGS is a bitmask consisting of the following flags:
2229 2: The function has a definition.
2230 4: The function is a friend.
2232 The TEMPLATE_COUNT is the number of references to qualifying
2233 template classes that appeared in the name of the function. For
2236 template <class T> struct S { void f(); };
2239 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2240 classes are not counted in the TEMPLATE_COUNT, so that in
2242 template <class T> struct S {};
2243 template <> struct S<int> { void f(); }
2244 template <> void S<int>::f();
2246 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2247 invalid; there should be no template <>.)
2249 If the function is a specialization, it is marked as such via
2250 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2251 is set up correctly, and it is added to the list of specializations
2252 for that template. */
2255 check_explicit_specialization (tree declarator,
2260 int have_def = flags & 2;
2261 int is_friend = flags & 4;
2262 int specialization = 0;
2263 int explicit_instantiation = 0;
2264 int member_specialization = 0;
2265 tree ctype = DECL_CLASS_CONTEXT (decl);
2266 tree dname = DECL_NAME (decl);
2271 if (!processing_specialization)
2274 tsk = tsk_excessive_parms;
2277 tsk = current_tmpl_spec_kind (template_count);
2282 if (processing_specialization)
2285 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2287 else if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2290 /* This could be something like:
2292 template <class T> void f(T);
2293 class S { friend void f<>(int); } */
2297 /* This case handles bogus declarations like template <>
2298 template <class T> void f<int>(); */
2300 error ("template-id %qD in declaration of primary template",
2307 case tsk_invalid_member_spec:
2308 /* The error has already been reported in
2309 check_specialization_scope. */
2310 return error_mark_node;
2312 case tsk_invalid_expl_inst:
2313 error ("template parameter list used in explicit instantiation");
2319 error ("definition provided for explicit instantiation");
2321 explicit_instantiation = 1;
2324 case tsk_excessive_parms:
2325 case tsk_insufficient_parms:
2326 if (tsk == tsk_excessive_parms)
2327 error ("too many template parameter lists in declaration of %qD",
2329 else if (template_header_count)
2330 error("too few template parameter lists in declaration of %qD", decl);
2332 error("explicit specialization of %qD must be introduced by "
2333 "%<template <>%>", decl);
2337 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2339 member_specialization = 1;
2345 if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2347 /* This case handles bogus declarations like template <>
2348 template <class T> void f<int>(); */
2350 if (uses_template_parms (declarator))
2351 error ("function template partial specialization %qD "
2352 "is not allowed", declarator);
2354 error ("template-id %qD in declaration of primary template",
2359 if (ctype && CLASSTYPE_TEMPLATE_INSTANTIATION (ctype))
2360 /* This is a specialization of a member template, without
2361 specialization the containing class. Something like:
2363 template <class T> struct S {
2364 template <class U> void f (U);
2366 template <> template <class U> void S<int>::f(U) {}
2368 That's a specialization -- but of the entire template. */
2376 if (specialization || member_specialization)
2378 tree t = TYPE_ARG_TYPES (TREE_TYPE (decl));
2379 for (; t; t = TREE_CHAIN (t))
2380 if (TREE_PURPOSE (t))
2382 permerror (input_location,
2383 "default argument specified in explicit specialization");
2388 if (specialization || member_specialization || explicit_instantiation)
2390 tree tmpl = NULL_TREE;
2391 tree targs = NULL_TREE;
2393 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2394 if (TREE_CODE (declarator) != TEMPLATE_ID_EXPR)
2398 gcc_assert (TREE_CODE (declarator) == IDENTIFIER_NODE);
2403 /* If there is no class context, the explicit instantiation
2404 must be at namespace scope. */
2405 gcc_assert (DECL_NAMESPACE_SCOPE_P (decl));
2407 /* Find the namespace binding, using the declaration
2409 fns = lookup_qualified_name (CP_DECL_CONTEXT (decl), dname,
2411 if (fns == error_mark_node || !is_overloaded_fn (fns))
2413 error ("%qD is not a template function", dname);
2414 fns = error_mark_node;
2418 tree fn = OVL_CURRENT (fns);
2419 if (!is_associated_namespace (CP_DECL_CONTEXT (decl),
2420 CP_DECL_CONTEXT (fn)))
2421 error ("%qD is not declared in %qD",
2422 decl, current_namespace);
2426 declarator = lookup_template_function (fns, NULL_TREE);
2429 if (declarator == error_mark_node)
2430 return error_mark_node;
2432 if (ctype != NULL_TREE && TYPE_BEING_DEFINED (ctype))
2434 if (!explicit_instantiation)
2435 /* A specialization in class scope. This is invalid,
2436 but the error will already have been flagged by
2437 check_specialization_scope. */
2438 return error_mark_node;
2441 /* It's not valid to write an explicit instantiation in
2444 class C { template void f(); }
2446 This case is caught by the parser. However, on
2449 template class C { void f(); };
2451 (which is invalid) we can get here. The error will be
2458 else if (ctype != NULL_TREE
2459 && (TREE_CODE (TREE_OPERAND (declarator, 0)) ==
2462 /* Find the list of functions in ctype that have the same
2463 name as the declared function. */
2464 tree name = TREE_OPERAND (declarator, 0);
2465 tree fns = NULL_TREE;
2468 if (constructor_name_p (name, ctype))
2470 int is_constructor = DECL_CONSTRUCTOR_P (decl);
2472 if (is_constructor ? !TYPE_HAS_USER_CONSTRUCTOR (ctype)
2473 : !CLASSTYPE_DESTRUCTORS (ctype))
2475 /* From [temp.expl.spec]:
2477 If such an explicit specialization for the member
2478 of a class template names an implicitly-declared
2479 special member function (clause _special_), the
2480 program is ill-formed.
2482 Similar language is found in [temp.explicit]. */
2483 error ("specialization of implicitly-declared special member function");
2484 return error_mark_node;
2487 name = is_constructor ? ctor_identifier : dtor_identifier;
2490 if (!DECL_CONV_FN_P (decl))
2492 idx = lookup_fnfields_1 (ctype, name);
2494 fns = VEC_index (tree, CLASSTYPE_METHOD_VEC (ctype), idx);
2498 VEC(tree,gc) *methods;
2501 /* For a type-conversion operator, we cannot do a
2502 name-based lookup. We might be looking for `operator
2503 int' which will be a specialization of `operator T'.
2504 So, we find *all* the conversion operators, and then
2505 select from them. */
2508 methods = CLASSTYPE_METHOD_VEC (ctype);
2510 for (idx = CLASSTYPE_FIRST_CONVERSION_SLOT;
2511 VEC_iterate (tree, methods, idx, ovl);
2514 if (!DECL_CONV_FN_P (OVL_CURRENT (ovl)))
2515 /* There are no more conversion functions. */
2518 /* Glue all these conversion functions together
2519 with those we already have. */
2520 for (; ovl; ovl = OVL_NEXT (ovl))
2521 fns = ovl_cons (OVL_CURRENT (ovl), fns);
2525 if (fns == NULL_TREE)
2527 error ("no member function %qD declared in %qT", name, ctype);
2528 return error_mark_node;
2531 TREE_OPERAND (declarator, 0) = fns;
2534 /* Figure out what exactly is being specialized at this point.
2535 Note that for an explicit instantiation, even one for a
2536 member function, we cannot tell apriori whether the
2537 instantiation is for a member template, or just a member
2538 function of a template class. Even if a member template is
2539 being instantiated, the member template arguments may be
2540 elided if they can be deduced from the rest of the
2542 tmpl = determine_specialization (declarator, decl,
2544 member_specialization,
2548 if (!tmpl || tmpl == error_mark_node)
2549 /* We couldn't figure out what this declaration was
2551 return error_mark_node;
2554 tree gen_tmpl = most_general_template (tmpl);
2556 if (explicit_instantiation)
2558 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2559 is done by do_decl_instantiation later. */
2561 int arg_depth = TMPL_ARGS_DEPTH (targs);
2562 int parm_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
2564 if (arg_depth > parm_depth)
2566 /* If TMPL is not the most general template (for
2567 example, if TMPL is a friend template that is
2568 injected into namespace scope), then there will
2569 be too many levels of TARGS. Remove some of them
2574 new_targs = make_tree_vec (parm_depth);
2575 for (i = arg_depth - parm_depth; i < arg_depth; ++i)
2576 TREE_VEC_ELT (new_targs, i - (arg_depth - parm_depth))
2577 = TREE_VEC_ELT (targs, i);
2581 return instantiate_template (tmpl, targs, tf_error);
2584 /* If we thought that the DECL was a member function, but it
2585 turns out to be specializing a static member function,
2586 make DECL a static member function as well. */
2587 if (DECL_STATIC_FUNCTION_P (tmpl)
2588 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2589 revert_static_member_fn (decl);
2591 /* If this is a specialization of a member template of a
2592 template class, we want to return the TEMPLATE_DECL, not
2593 the specialization of it. */
2594 if (tsk == tsk_template)
2596 tree result = DECL_TEMPLATE_RESULT (tmpl);
2597 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
2598 DECL_INITIAL (result) = NULL_TREE;
2602 DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl);
2603 DECL_SOURCE_LOCATION (result)
2604 = DECL_SOURCE_LOCATION (decl);
2605 /* We want to use the argument list specified in the
2606 definition, not in the original declaration. */
2607 DECL_ARGUMENTS (result) = DECL_ARGUMENTS (decl);
2608 for (parm = DECL_ARGUMENTS (result); parm;
2609 parm = DECL_CHAIN (parm))
2610 DECL_CONTEXT (parm) = result;
2612 return register_specialization (tmpl, gen_tmpl, targs,
2616 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2617 DECL_TEMPLATE_INFO (decl) = build_template_info (tmpl, targs);
2619 /* Inherit default function arguments from the template
2620 DECL is specializing. */
2621 copy_default_args_to_explicit_spec (decl);
2623 /* This specialization has the same protection as the
2624 template it specializes. */
2625 TREE_PRIVATE (decl) = TREE_PRIVATE (gen_tmpl);
2626 TREE_PROTECTED (decl) = TREE_PROTECTED (gen_tmpl);
2628 /* 7.1.1-1 [dcl.stc]
2630 A storage-class-specifier shall not be specified in an
2631 explicit specialization...
2633 The parser rejects these, so unless action is taken here,
2634 explicit function specializations will always appear with
2637 The action recommended by the C++ CWG in response to C++
2638 defect report 605 is to make the storage class and linkage
2639 of the explicit specialization match the templated function:
2641 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2643 if (tsk == tsk_expl_spec && DECL_FUNCTION_TEMPLATE_P (gen_tmpl))
2645 tree tmpl_func = DECL_TEMPLATE_RESULT (gen_tmpl);
2646 gcc_assert (TREE_CODE (tmpl_func) == FUNCTION_DECL);
2648 /* This specialization has the same linkage and visibility as
2649 the function template it specializes. */
2650 TREE_PUBLIC (decl) = TREE_PUBLIC (tmpl_func);
2651 if (! TREE_PUBLIC (decl))
2653 DECL_INTERFACE_KNOWN (decl) = 1;
2654 DECL_NOT_REALLY_EXTERN (decl) = 1;
2656 DECL_THIS_STATIC (decl) = DECL_THIS_STATIC (tmpl_func);
2657 if (DECL_VISIBILITY_SPECIFIED (tmpl_func))
2659 DECL_VISIBILITY_SPECIFIED (decl) = 1;
2660 DECL_VISIBILITY (decl) = DECL_VISIBILITY (tmpl_func);
2664 /* If DECL is a friend declaration, declared using an
2665 unqualified name, the namespace associated with DECL may
2666 have been set incorrectly. For example, in:
2668 template <typename T> void f(T);
2670 struct S { friend void f<int>(int); }
2673 we will have set the DECL_CONTEXT for the friend
2674 declaration to N, rather than to the global namespace. */
2675 if (DECL_NAMESPACE_SCOPE_P (decl))
2676 DECL_CONTEXT (decl) = DECL_CONTEXT (tmpl);
2678 if (is_friend && !have_def)
2679 /* This is not really a declaration of a specialization.
2680 It's just the name of an instantiation. But, it's not
2681 a request for an instantiation, either. */
2682 SET_DECL_IMPLICIT_INSTANTIATION (decl);
2683 else if (DECL_CONSTRUCTOR_P (decl) || DECL_DESTRUCTOR_P (decl))
2684 /* This is indeed a specialization. In case of constructors
2685 and destructors, we need in-charge and not-in-charge
2686 versions in V3 ABI. */
2687 clone_function_decl (decl, /*update_method_vec_p=*/0);
2689 /* Register this specialization so that we can find it
2691 decl = register_specialization (decl, gen_tmpl, targs, is_friend, 0);
2698 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2699 parameters. These are represented in the same format used for
2700 DECL_TEMPLATE_PARMS. */
2703 comp_template_parms (const_tree parms1, const_tree parms2)
2708 if (parms1 == parms2)
2711 for (p1 = parms1, p2 = parms2;
2712 p1 != NULL_TREE && p2 != NULL_TREE;
2713 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2))
2715 tree t1 = TREE_VALUE (p1);
2716 tree t2 = TREE_VALUE (p2);
2719 gcc_assert (TREE_CODE (t1) == TREE_VEC);
2720 gcc_assert (TREE_CODE (t2) == TREE_VEC);
2722 if (TREE_VEC_LENGTH (t1) != TREE_VEC_LENGTH (t2))
2725 for (i = 0; i < TREE_VEC_LENGTH (t2); ++i)
2727 tree parm1 = TREE_VALUE (TREE_VEC_ELT (t1, i));
2728 tree parm2 = TREE_VALUE (TREE_VEC_ELT (t2, i));
2730 /* If either of the template parameters are invalid, assume
2731 they match for the sake of error recovery. */
2732 if (parm1 == error_mark_node || parm2 == error_mark_node)
2735 if (TREE_CODE (parm1) != TREE_CODE (parm2))
2738 if (TREE_CODE (parm1) == TEMPLATE_TYPE_PARM
2739 && (TEMPLATE_TYPE_PARAMETER_PACK (parm1)
2740 == TEMPLATE_TYPE_PARAMETER_PACK (parm2)))
2742 else if (!same_type_p (TREE_TYPE (parm1), TREE_TYPE (parm2)))
2747 if ((p1 != NULL_TREE) != (p2 != NULL_TREE))
2748 /* One set of parameters has more parameters lists than the
2755 /* Determine whether PARM is a parameter pack. */
2758 template_parameter_pack_p (const_tree parm)
2760 /* Determine if we have a non-type template parameter pack. */
2761 if (TREE_CODE (parm) == PARM_DECL)
2762 return (DECL_TEMPLATE_PARM_P (parm)
2763 && TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)));
2764 if (TREE_CODE (parm) == TEMPLATE_PARM_INDEX)
2765 return TEMPLATE_PARM_PARAMETER_PACK (parm);
2767 /* If this is a list of template parameters, we could get a
2768 TYPE_DECL or a TEMPLATE_DECL. */
2769 if (TREE_CODE (parm) == TYPE_DECL || TREE_CODE (parm) == TEMPLATE_DECL)
2770 parm = TREE_TYPE (parm);
2772 /* Otherwise it must be a type template parameter. */
2773 return ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
2774 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM)
2775 && TEMPLATE_TYPE_PARAMETER_PACK (parm));
2778 /* Determine if T is a function parameter pack. */
2781 function_parameter_pack_p (const_tree t)
2783 if (t && TREE_CODE (t) == PARM_DECL)
2784 return FUNCTION_PARAMETER_PACK_P (t);
2788 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2789 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2792 get_function_template_decl (const_tree primary_func_tmpl_inst)
2794 if (! primary_func_tmpl_inst
2795 || TREE_CODE (primary_func_tmpl_inst) != FUNCTION_DECL
2796 || ! primary_template_instantiation_p (primary_func_tmpl_inst))
2799 return DECL_TEMPLATE_RESULT (DECL_TI_TEMPLATE (primary_func_tmpl_inst));
2802 /* Return true iff the function parameter PARAM_DECL was expanded
2803 from the function parameter pack PACK. */
2806 function_parameter_expanded_from_pack_p (tree param_decl, tree pack)
2808 if (DECL_ARTIFICIAL (param_decl)
2809 || !function_parameter_pack_p (pack))
2812 /* The parameter pack and its pack arguments have the same
2814 return DECL_PARM_INDEX (pack) == DECL_PARM_INDEX (param_decl);
2817 /* Determine whether ARGS describes a variadic template args list,
2818 i.e., one that is terminated by a template argument pack. */
2821 template_args_variadic_p (tree args)
2826 if (args == NULL_TREE)
2829 args = INNERMOST_TEMPLATE_ARGS (args);
2830 nargs = TREE_VEC_LENGTH (args);
2835 last_parm = TREE_VEC_ELT (args, nargs - 1);
2837 return ARGUMENT_PACK_P (last_parm);
2840 /* Generate a new name for the parameter pack name NAME (an
2841 IDENTIFIER_NODE) that incorporates its */
2844 make_ith_pack_parameter_name (tree name, int i)
2846 /* Munge the name to include the parameter index. */
2847 #define NUMBUF_LEN 128
2848 char numbuf[NUMBUF_LEN];
2852 snprintf (numbuf, NUMBUF_LEN, "%i", i);
2853 newname_len = IDENTIFIER_LENGTH (name)
2854 + strlen (numbuf) + 2;
2855 newname = (char*)alloca (newname_len);
2856 snprintf (newname, newname_len,
2857 "%s#%i", IDENTIFIER_POINTER (name), i);
2858 return get_identifier (newname);
2861 /* Return true if T is a primary function, class or alias template
2865 primary_template_instantiation_p (const_tree t)
2870 if (TREE_CODE (t) == FUNCTION_DECL)
2871 return DECL_LANG_SPECIFIC (t)
2872 && DECL_TEMPLATE_INSTANTIATION (t)
2873 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (t));
2874 else if (CLASS_TYPE_P (t) && !TYPE_DECL_ALIAS_P (TYPE_NAME (t)))
2875 return CLASSTYPE_TEMPLATE_INSTANTIATION (t)
2876 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (t));
2878 && TYPE_TEMPLATE_INFO (t)
2879 && PRIMARY_TEMPLATE_P (TYPE_TI_TEMPLATE (t))
2880 && DECL_TEMPLATE_INSTANTIATION (TYPE_NAME (t)))
2885 /* Return true if PARM is a template template parameter. */
2888 template_template_parameter_p (const_tree parm)
2890 return DECL_TEMPLATE_TEMPLATE_PARM_P (parm);
2893 /* Return the template parameters of T if T is a
2894 primary template instantiation, NULL otherwise. */
2897 get_primary_template_innermost_parameters (const_tree t)
2899 tree parms = NULL, template_info = NULL;
2901 if ((template_info = get_template_info (t))
2902 && primary_template_instantiation_p (t))
2903 parms = INNERMOST_TEMPLATE_PARMS
2904 (DECL_TEMPLATE_PARMS (TI_TEMPLATE (template_info)));
2909 /* Return the template parameters of the LEVELth level from the full list
2910 of template parameters PARMS. */
2913 get_template_parms_at_level (tree parms, int level)
2917 || TREE_CODE (parms) != TREE_LIST
2918 || level > TMPL_PARMS_DEPTH (parms))
2921 for (p = parms; p; p = TREE_CHAIN (p))
2922 if (TMPL_PARMS_DEPTH (p) == level)
2928 /* Returns the template arguments of T if T is a template instantiation,
2932 get_template_innermost_arguments (const_tree t)
2934 tree args = NULL, template_info = NULL;
2936 if ((template_info = get_template_info (t))
2937 && TI_ARGS (template_info))
2938 args = INNERMOST_TEMPLATE_ARGS (TI_ARGS (template_info));
2943 /* Return the argument pack elements of T if T is a template argument pack,
2947 get_template_argument_pack_elems (const_tree t)
2949 if (TREE_CODE (t) != TYPE_ARGUMENT_PACK
2950 && TREE_CODE (t) != NONTYPE_ARGUMENT_PACK)
2953 return ARGUMENT_PACK_ARGS (t);
2956 /* Structure used to track the progress of find_parameter_packs_r. */
2957 struct find_parameter_pack_data
2959 /* TREE_LIST that will contain all of the parameter packs found by
2961 tree* parameter_packs;
2963 /* Set of AST nodes that have been visited by the traversal. */
2964 struct pointer_set_t *visited;
2967 /* Identifies all of the argument packs that occur in a template
2968 argument and appends them to the TREE_LIST inside DATA, which is a
2969 find_parameter_pack_data structure. This is a subroutine of
2970 make_pack_expansion and uses_parameter_packs. */
2972 find_parameter_packs_r (tree *tp, int *walk_subtrees, void* data)
2975 struct find_parameter_pack_data* ppd =
2976 (struct find_parameter_pack_data*)data;
2977 bool parameter_pack_p = false;
2979 /* Handle type aliases/typedefs. */
2982 && TREE_CODE (TYPE_NAME (t)) == TYPE_DECL
2983 && TYPE_DECL_ALIAS_P (TYPE_NAME (t)))
2985 if (TYPE_TEMPLATE_INFO (t))
2986 cp_walk_tree (&TYPE_TI_ARGS (t),
2987 &find_parameter_packs_r,
2993 /* Identify whether this is a parameter pack or not. */
2994 switch (TREE_CODE (t))
2996 case TEMPLATE_PARM_INDEX:
2997 if (TEMPLATE_PARM_PARAMETER_PACK (t))
2998 parameter_pack_p = true;
3001 case TEMPLATE_TYPE_PARM:
3002 t = TYPE_MAIN_VARIANT (t);
3003 case TEMPLATE_TEMPLATE_PARM:
3004 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
3005 parameter_pack_p = true;
3009 if (FUNCTION_PARAMETER_PACK_P (t))
3011 /* We don't want to walk into the type of a PARM_DECL,
3012 because we don't want to see the type parameter pack. */
3014 parameter_pack_p = true;
3019 parameter_pack_p = true;
3022 /* Not a parameter pack. */
3026 if (parameter_pack_p)
3028 /* Add this parameter pack to the list. */
3029 *ppd->parameter_packs = tree_cons (NULL_TREE, t, *ppd->parameter_packs);
3033 cp_walk_tree (&TYPE_CONTEXT (t),
3034 &find_parameter_packs_r, ppd, ppd->visited);
3036 /* This switch statement will return immediately if we don't find a
3038 switch (TREE_CODE (t))
3040 case TEMPLATE_PARM_INDEX:
3043 case BOUND_TEMPLATE_TEMPLATE_PARM:
3044 /* Check the template itself. */
3045 cp_walk_tree (&TREE_TYPE (TYPE_TI_TEMPLATE (t)),
3046 &find_parameter_packs_r, ppd, ppd->visited);
3047 /* Check the template arguments. */
3048 cp_walk_tree (&TYPE_TI_ARGS (t), &find_parameter_packs_r, ppd,
3053 case TEMPLATE_TYPE_PARM:
3054 case TEMPLATE_TEMPLATE_PARM:
3061 if (TYPE_PTRMEMFUNC_P (t))
3067 if (TYPE_TEMPLATE_INFO (t))
3068 cp_walk_tree (&TI_ARGS (TYPE_TEMPLATE_INFO (t)),
3069 &find_parameter_packs_r, ppd, ppd->visited);
3076 cp_walk_tree (&TREE_TYPE (t),
3077 &find_parameter_packs_r, ppd, ppd->visited);
3081 cp_walk_tree (&TYPENAME_TYPE_FULLNAME (t), &find_parameter_packs_r,
3086 case TYPE_PACK_EXPANSION:
3087 case EXPR_PACK_EXPANSION:
3092 cp_walk_tree (&TYPE_MAX_VALUE (t), &find_parameter_packs_r,
3097 case IDENTIFIER_NODE:
3098 cp_walk_tree (&TREE_TYPE (t), &find_parameter_packs_r, ppd,
3110 /* Determines if the expression or type T uses any parameter packs. */
3112 uses_parameter_packs (tree t)
3114 tree parameter_packs = NULL_TREE;
3115 struct find_parameter_pack_data ppd;
3116 ppd.parameter_packs = ¶meter_packs;
3117 ppd.visited = pointer_set_create ();
3118 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
3119 pointer_set_destroy (ppd.visited);
3120 return parameter_packs != NULL_TREE;
3123 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3124 representation a base-class initializer into a parameter pack
3125 expansion. If all goes well, the resulting node will be an
3126 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3129 make_pack_expansion (tree arg)
3132 tree parameter_packs = NULL_TREE;
3133 bool for_types = false;
3134 struct find_parameter_pack_data ppd;
3136 if (!arg || arg == error_mark_node)
3139 if (TREE_CODE (arg) == TREE_LIST)
3141 /* The only time we will see a TREE_LIST here is for a base
3142 class initializer. In this case, the TREE_PURPOSE will be a
3143 _TYPE node (representing the base class expansion we're
3144 initializing) and the TREE_VALUE will be a TREE_LIST
3145 containing the initialization arguments.
3147 The resulting expansion looks somewhat different from most
3148 expansions. Rather than returning just one _EXPANSION, we
3149 return a TREE_LIST whose TREE_PURPOSE is a
3150 TYPE_PACK_EXPANSION containing the bases that will be
3151 initialized. The TREE_VALUE will be identical to the
3152 original TREE_VALUE, which is a list of arguments that will
3153 be passed to each base. We do not introduce any new pack
3154 expansion nodes into the TREE_VALUE (although it is possible
3155 that some already exist), because the TREE_PURPOSE and
3156 TREE_VALUE all need to be expanded together with the same
3157 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3158 resulting TREE_PURPOSE will mention the parameter packs in
3159 both the bases and the arguments to the bases. */
3162 tree parameter_packs = NULL_TREE;
3164 /* Determine which parameter packs will be used by the base
3166 ppd.visited = pointer_set_create ();
3167 ppd.parameter_packs = ¶meter_packs;
3168 cp_walk_tree (&TREE_PURPOSE (arg), &find_parameter_packs_r,
3171 if (parameter_packs == NULL_TREE)
3173 error ("base initializer expansion %<%T%> contains no parameter packs", arg);
3174 pointer_set_destroy (ppd.visited);
3175 return error_mark_node;
3178 if (TREE_VALUE (arg) != void_type_node)
3180 /* Collect the sets of parameter packs used in each of the
3181 initialization arguments. */
3182 for (value = TREE_VALUE (arg); value; value = TREE_CHAIN (value))
3184 /* Determine which parameter packs will be expanded in this
3186 cp_walk_tree (&TREE_VALUE (value), &find_parameter_packs_r,
3191 pointer_set_destroy (ppd.visited);
3193 /* Create the pack expansion type for the base type. */
3194 purpose = cxx_make_type (TYPE_PACK_EXPANSION);
3195 SET_PACK_EXPANSION_PATTERN (purpose, TREE_PURPOSE (arg));
3196 PACK_EXPANSION_PARAMETER_PACKS (purpose) = parameter_packs;
3198 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3199 they will rarely be compared to anything. */
3200 SET_TYPE_STRUCTURAL_EQUALITY (purpose);
3202 return tree_cons (purpose, TREE_VALUE (arg), NULL_TREE);
3205 if (TYPE_P (arg) || TREE_CODE (arg) == TEMPLATE_DECL)
3208 /* Build the PACK_EXPANSION_* node. */
3210 ? cxx_make_type (TYPE_PACK_EXPANSION)
3211 : make_node (EXPR_PACK_EXPANSION);
3212 SET_PACK_EXPANSION_PATTERN (result, arg);
3213 if (TREE_CODE (result) == EXPR_PACK_EXPANSION)
3215 /* Propagate type and const-expression information. */
3216 TREE_TYPE (result) = TREE_TYPE (arg);
3217 TREE_CONSTANT (result) = TREE_CONSTANT (arg);
3220 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3221 they will rarely be compared to anything. */
3222 SET_TYPE_STRUCTURAL_EQUALITY (result);
3224 /* Determine which parameter packs will be expanded. */
3225 ppd.parameter_packs = ¶meter_packs;
3226 ppd.visited = pointer_set_create ();
3227 cp_walk_tree (&arg, &find_parameter_packs_r, &ppd, ppd.visited);
3228 pointer_set_destroy (ppd.visited);
3230 /* Make sure we found some parameter packs. */
3231 if (parameter_packs == NULL_TREE)
3234 error ("expansion pattern %<%T%> contains no argument packs", arg);
3236 error ("expansion pattern %<%E%> contains no argument packs", arg);
3237 return error_mark_node;
3239 PACK_EXPANSION_PARAMETER_PACKS (result) = parameter_packs;
3244 /* Checks T for any "bare" parameter packs, which have not yet been
3245 expanded, and issues an error if any are found. This operation can
3246 only be done on full expressions or types (e.g., an expression
3247 statement, "if" condition, etc.), because we could have expressions like:
3249 foo(f(g(h(args)))...)
3251 where "args" is a parameter pack. check_for_bare_parameter_packs
3252 should not be called for the subexpressions args, h(args),
3253 g(h(args)), or f(g(h(args))), because we would produce erroneous
3256 Returns TRUE and emits an error if there were bare parameter packs,
3257 returns FALSE otherwise. */
3259 check_for_bare_parameter_packs (tree t)
3261 tree parameter_packs = NULL_TREE;
3262 struct find_parameter_pack_data ppd;
3264 if (!processing_template_decl || !t || t == error_mark_node)
3267 if (TREE_CODE (t) == TYPE_DECL)
3270 ppd.parameter_packs = ¶meter_packs;
3271 ppd.visited = pointer_set_create ();
3272 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
3273 pointer_set_destroy (ppd.visited);
3275 if (parameter_packs)
3277 error ("parameter packs not expanded with %<...%>:");
3278 while (parameter_packs)
3280 tree pack = TREE_VALUE (parameter_packs);
3281 tree name = NULL_TREE;
3283 if (TREE_CODE (pack) == TEMPLATE_TYPE_PARM
3284 || TREE_CODE (pack) == TEMPLATE_TEMPLATE_PARM)
3285 name = TYPE_NAME (pack);
3286 else if (TREE_CODE (pack) == TEMPLATE_PARM_INDEX)
3287 name = DECL_NAME (TEMPLATE_PARM_DECL (pack));
3289 name = DECL_NAME (pack);
3292 inform (input_location, " %qD", name);
3294 inform (input_location, " <anonymous>");
3296 parameter_packs = TREE_CHAIN (parameter_packs);
3305 /* Expand any parameter packs that occur in the template arguments in
3308 expand_template_argument_pack (tree args)
3310 tree result_args = NULL_TREE;
3311 int in_arg, out_arg = 0, nargs = args ? TREE_VEC_LENGTH (args) : 0;
3312 int num_result_args = -1;
3313 int non_default_args_count = -1;
3315 /* First, determine if we need to expand anything, and the number of
3316 slots we'll need. */
3317 for (in_arg = 0; in_arg < nargs; ++in_arg)
3319 tree arg = TREE_VEC_ELT (args, in_arg);
3320 if (arg == NULL_TREE)
3322 if (ARGUMENT_PACK_P (arg))
3324 int num_packed = TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg));
3325 if (num_result_args < 0)
3326 num_result_args = in_arg + num_packed;
3328 num_result_args += num_packed;
3332 if (num_result_args >= 0)
3337 /* If no expansion is necessary, we're done. */
3338 if (num_result_args < 0)
3341 /* Expand arguments. */
3342 result_args = make_tree_vec (num_result_args);
3343 if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (args))
3344 non_default_args_count =
3345 GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (args);
3346 for (in_arg = 0; in_arg < nargs; ++in_arg)
3348 tree arg = TREE_VEC_ELT (args, in_arg);
3349 if (ARGUMENT_PACK_P (arg))
3351 tree packed = ARGUMENT_PACK_ARGS (arg);
3352 int i, num_packed = TREE_VEC_LENGTH (packed);
3353 for (i = 0; i < num_packed; ++i, ++out_arg)
3354 TREE_VEC_ELT (result_args, out_arg) = TREE_VEC_ELT(packed, i);
3355 if (non_default_args_count > 0)
3356 non_default_args_count += num_packed;
3360 TREE_VEC_ELT (result_args, out_arg) = arg;
3364 if (non_default_args_count >= 0)
3365 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (result_args, non_default_args_count);
3369 /* Checks if DECL shadows a template parameter.
3371 [temp.local]: A template-parameter shall not be redeclared within its
3372 scope (including nested scopes).
3374 Emits an error and returns TRUE if the DECL shadows a parameter,
3375 returns FALSE otherwise. */
3378 check_template_shadow (tree decl)
3382 /* If we're not in a template, we can't possibly shadow a template
3384 if (!current_template_parms)
3387 /* Figure out what we're shadowing. */
3388 if (TREE_CODE (decl) == OVERLOAD)
3389 decl = OVL_CURRENT (decl);
3390 olddecl = innermost_non_namespace_value (DECL_NAME (decl));
3392 /* If there's no previous binding for this name, we're not shadowing
3393 anything, let alone a template parameter. */
3397 /* If we're not shadowing a template parameter, we're done. Note
3398 that OLDDECL might be an OVERLOAD (or perhaps even an
3399 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3401 if (!DECL_P (olddecl) || !DECL_TEMPLATE_PARM_P (olddecl))
3404 /* We check for decl != olddecl to avoid bogus errors for using a
3405 name inside a class. We check TPFI to avoid duplicate errors for
3406 inline member templates. */
3408 || TEMPLATE_PARMS_FOR_INLINE (current_template_parms))
3411 error ("declaration of %q+#D", decl);
3412 error (" shadows template parm %q+#D", olddecl);
3416 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3417 ORIG_LEVEL, DECL, and TYPE. NUM_SIBLINGS is the total number of
3418 template parameters. */
3421 build_template_parm_index (int index,
3428 tree t = make_node (TEMPLATE_PARM_INDEX);
3429 TEMPLATE_PARM_IDX (t) = index;
3430 TEMPLATE_PARM_LEVEL (t) = level;
3431 TEMPLATE_PARM_ORIG_LEVEL (t) = orig_level;
3432 TEMPLATE_PARM_NUM_SIBLINGS (t) = num_siblings;
3433 TEMPLATE_PARM_DECL (t) = decl;
3434 TREE_TYPE (t) = type;
3435 TREE_CONSTANT (t) = TREE_CONSTANT (decl);
3436 TREE_READONLY (t) = TREE_READONLY (decl);
3441 /* Find the canonical type parameter for the given template type
3442 parameter. Returns the canonical type parameter, which may be TYPE
3443 if no such parameter existed. */
3446 canonical_type_parameter (tree type)
3449 int idx = TEMPLATE_TYPE_IDX (type);
3450 if (!canonical_template_parms)
3451 canonical_template_parms = VEC_alloc (tree, gc, idx+1);
3453 while (VEC_length (tree, canonical_template_parms) <= (unsigned)idx)
3454 VEC_safe_push (tree, gc, canonical_template_parms, NULL_TREE);
3456 list = VEC_index (tree, canonical_template_parms, idx);
3457 while (list && !comptypes (type, TREE_VALUE (list), COMPARE_STRUCTURAL))
3458 list = TREE_CHAIN (list);
3461 return TREE_VALUE (list);
3464 VEC_replace(tree, canonical_template_parms, idx,
3465 tree_cons (NULL_TREE, type,
3466 VEC_index (tree, canonical_template_parms, idx)));
3471 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3472 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3473 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3474 new one is created. */
3477 reduce_template_parm_level (tree index, tree type, int levels, tree args,
3478 tsubst_flags_t complain)
3480 if (TEMPLATE_PARM_DESCENDANTS (index) == NULL_TREE
3481 || (TEMPLATE_PARM_LEVEL (TEMPLATE_PARM_DESCENDANTS (index))
3482 != TEMPLATE_PARM_LEVEL (index) - levels)
3483 || !same_type_p (type, TREE_TYPE (TEMPLATE_PARM_DESCENDANTS (index))))
3485 tree orig_decl = TEMPLATE_PARM_DECL (index);
3488 decl = build_decl (DECL_SOURCE_LOCATION (orig_decl),
3489 TREE_CODE (orig_decl), DECL_NAME (orig_decl), type);
3490 TREE_CONSTANT (decl) = TREE_CONSTANT (orig_decl);
3491 TREE_READONLY (decl) = TREE_READONLY (orig_decl);
3492 DECL_ARTIFICIAL (decl) = 1;
3493 SET_DECL_TEMPLATE_PARM_P (decl);
3495 t = build_template_parm_index (TEMPLATE_PARM_IDX (index),
3496 TEMPLATE_PARM_LEVEL (index) - levels,
3497 TEMPLATE_PARM_ORIG_LEVEL (index),
3498 TEMPLATE_PARM_NUM_SIBLINGS (index),
3500 TEMPLATE_PARM_DESCENDANTS (index) = t;
3501 TEMPLATE_PARM_PARAMETER_PACK (t)
3502 = TEMPLATE_PARM_PARAMETER_PACK (index);
3504 /* Template template parameters need this. */
3505 if (TREE_CODE (decl) == TEMPLATE_DECL)
3506 DECL_TEMPLATE_PARMS (decl) = tsubst_template_parms
3507 (DECL_TEMPLATE_PARMS (TEMPLATE_PARM_DECL (index)),
3511 return TEMPLATE_PARM_DESCENDANTS (index);
3514 /* Process information from new template parameter PARM and append it
3515 to the LIST being built. This new parameter is a non-type
3516 parameter iff IS_NON_TYPE is true. This new parameter is a
3517 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3518 is in PARM_LOC. NUM_TEMPLATE_PARMS is the size of the template
3519 parameter list PARM belongs to. This is used used to create a
3520 proper canonical type for the type of PARM that is to be created,
3521 iff PARM is a type. If the size is not known, this parameter shall
3525 process_template_parm (tree list, location_t parm_loc, tree parm,
3526 bool is_non_type, bool is_parameter_pack,
3527 unsigned num_template_parms)
3534 gcc_assert (TREE_CODE (parm) == TREE_LIST);
3535 defval = TREE_PURPOSE (parm);
3539 tree p = tree_last (list);
3541 if (p && TREE_VALUE (p) != error_mark_node)
3544 if (TREE_CODE (p) == TYPE_DECL || TREE_CODE (p) == TEMPLATE_DECL)
3545 idx = TEMPLATE_TYPE_IDX (TREE_TYPE (p));
3547 idx = TEMPLATE_PARM_IDX (DECL_INITIAL (p));
3557 parm = TREE_VALUE (parm);
3559 SET_DECL_TEMPLATE_PARM_P (parm);
3561 if (TREE_TYPE (parm) == error_mark_node)
3563 err_parm_list = build_tree_list (defval, parm);
3564 TREE_VALUE (err_parm_list) = error_mark_node;
3565 return chainon (list, err_parm_list);
3571 The top-level cv-qualifiers on the template-parameter are
3572 ignored when determining its type. */
3573 TREE_TYPE (parm) = TYPE_MAIN_VARIANT (TREE_TYPE (parm));
3574 if (invalid_nontype_parm_type_p (TREE_TYPE (parm), 1))
3576 err_parm_list = build_tree_list (defval, parm);
3577 TREE_VALUE (err_parm_list) = error_mark_node;
3578 return chainon (list, err_parm_list);
3581 if (uses_parameter_packs (TREE_TYPE (parm)) && !is_parameter_pack)
3583 /* This template parameter is not a parameter pack, but it
3584 should be. Complain about "bare" parameter packs. */
3585 check_for_bare_parameter_packs (TREE_TYPE (parm));
3587 /* Recover by calling this a parameter pack. */
3588 is_parameter_pack = true;
3592 /* A template parameter is not modifiable. */
3593 TREE_CONSTANT (parm) = 1;
3594 TREE_READONLY (parm) = 1;
3595 decl = build_decl (parm_loc,
3596 CONST_DECL, DECL_NAME (parm), TREE_TYPE (parm));
3597 TREE_CONSTANT (decl) = 1;
3598 TREE_READONLY (decl) = 1;
3599 DECL_INITIAL (parm) = DECL_INITIAL (decl)
3600 = build_template_parm_index (idx, processing_template_decl,
3601 processing_template_decl,
3603 decl, TREE_TYPE (parm));
3605 TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))
3606 = is_parameter_pack;
3611 parm = TREE_VALUE (TREE_VALUE (parm));
3613 if (parm && TREE_CODE (parm) == TEMPLATE_DECL)
3615 t = cxx_make_type (TEMPLATE_TEMPLATE_PARM);
3616 /* This is for distinguishing between real templates and template
3617 template parameters */
3618 TREE_TYPE (parm) = t;
3619 TREE_TYPE (DECL_TEMPLATE_RESULT (parm)) = t;
3624 t = cxx_make_type (TEMPLATE_TYPE_PARM);
3625 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3626 decl = build_decl (parm_loc,
3627 TYPE_DECL, parm, t);
3630 TYPE_NAME (t) = decl;
3631 TYPE_STUB_DECL (t) = decl;
3633 TEMPLATE_TYPE_PARM_INDEX (t)
3634 = build_template_parm_index (idx, processing_template_decl,
3635 processing_template_decl,
3637 decl, TREE_TYPE (parm));
3638 TEMPLATE_TYPE_PARAMETER_PACK (t) = is_parameter_pack;
3639 TYPE_CANONICAL (t) = canonical_type_parameter (t);
3641 DECL_ARTIFICIAL (decl) = 1;
3642 SET_DECL_TEMPLATE_PARM_P (decl);
3644 parm = build_tree_list (defval, parm);
3645 return chainon (list, parm);
3648 /* The end of a template parameter list has been reached. Process the
3649 tree list into a parameter vector, converting each parameter into a more
3650 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3654 end_template_parm_list (tree parms)
3658 tree saved_parmlist = make_tree_vec (list_length (parms));
3660 current_template_parms
3661 = tree_cons (size_int (processing_template_decl),
3662 saved_parmlist, current_template_parms);
3664 for (parm = parms, nparms = 0; parm; parm = next, nparms++)
3666 next = TREE_CHAIN (parm);
3667 TREE_VEC_ELT (saved_parmlist, nparms) = parm;
3668 TREE_CHAIN (parm) = NULL_TREE;
3671 --processing_template_parmlist;
3673 return saved_parmlist;
3676 /* Create a new type almost identical to TYPE but which has the
3677 following differences:
3679 1/ T has a new TEMPLATE_PARM_INDEX that carries the new number of
3680 template sibling parameters of T.
3682 2/ T has a new canonical type that matches the new number
3685 3/ From now on, T is going to be what lookups referring to the
3686 name of TYPE will return. No lookup should return TYPE anymore.
3688 NUM_PARMS is the new number of sibling parms TYPE belongs to.
3690 This is a subroutine of fixup_template_parms. */
3693 fixup_template_type_parm_type (tree type, int num_parms)
3695 tree orig_idx = TEMPLATE_TYPE_PARM_INDEX (type), idx;
3697 /* This is the decl which name is inserted into the symbol table for
3698 the template parm type. So whenever we lookup the type name, this
3699 is the DECL we get. */
3702 /* Do not fix up the type twice. */
3703 if (orig_idx && TEMPLATE_PARM_NUM_SIBLINGS (orig_idx) != 0)
3706 t = copy_type (type);
3707 decl = TYPE_NAME (t);
3709 TYPE_MAIN_VARIANT (t) = t;
3710 TYPE_NEXT_VARIANT (t)= NULL_TREE;
3711 TYPE_POINTER_TO (t) = 0;
3712 TYPE_REFERENCE_TO (t) = 0;
3714 idx = build_template_parm_index (TEMPLATE_PARM_IDX (orig_idx),
3715 TEMPLATE_PARM_LEVEL (orig_idx),
3716 TEMPLATE_PARM_ORIG_LEVEL (orig_idx),
3719 TEMPLATE_PARM_DESCENDANTS (idx) = TEMPLATE_PARM_DESCENDANTS (orig_idx);
3720 TEMPLATE_PARM_PARAMETER_PACK (idx) = TEMPLATE_PARM_PARAMETER_PACK (orig_idx);
3721 TEMPLATE_TYPE_PARM_INDEX (t) = idx;
3723 TYPE_STUB_DECL (t) = decl;
3724 TEMPLATE_TYPE_DECL (t) = decl;
3725 if (TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM)
3726 TREE_TYPE (DECL_TEMPLATE_RESULT (decl)) = t;
3728 /* Update the type associated to the type name stored in the symbol
3729 table. Now, whenever the type name is looked up, the resulting
3730 type is properly fixed up. */
3731 TREE_TYPE (decl) = t;
3733 TYPE_CANONICAL (t) = canonical_type_parameter (t);
3738 /* Create and return a new TEMPLATE_PARM_INDEX that is almost
3739 identical to I, but that is fixed up as to:
3741 1/ carry the number of sibling parms (NUM_PARMS) of the template
3742 parm represented by I.
3744 2/ replace all references to template parm types declared before I
3745 (in the same template parm list as I) by references to template
3746 parm types contained in ARGS. ARGS should contain the list of
3747 template parms that have been fixed up so far, in a form suitable
3748 to be passed to tsubst.
3750 This is a subroutine of fixup_template_parms. */
3753 fixup_template_parm_index (tree i, tree args, int num_parms)
3755 tree index, decl, type;
3758 || TREE_CODE (i) != TEMPLATE_PARM_INDEX
3759 /* Do not fix up the index twice. */
3760 || (TEMPLATE_PARM_NUM_SIBLINGS (i) != 0))
3763 decl = TEMPLATE_PARM_DECL (i);
3764 type = TREE_TYPE (decl);
3766 index = build_template_parm_index (TEMPLATE_PARM_IDX (i),
3767 TEMPLATE_PARM_LEVEL (i),
3768 TEMPLATE_PARM_ORIG_LEVEL (i),
3772 TEMPLATE_PARM_DESCENDANTS (index) = TEMPLATE_PARM_DESCENDANTS (i);
3773 TEMPLATE_PARM_PARAMETER_PACK (index) = TEMPLATE_PARM_PARAMETER_PACK (i);
3775 type = tsubst (type, args, tf_none, NULL_TREE);
3777 TREE_TYPE (decl) = type;
3778 TREE_TYPE (index) = type;
3784 This is a subroutine of fixup_template_parms.
3786 It computes the canonical type of the type of the template
3787 parameter PARM_DESC and update all references to that type so that
3788 they use the newly computed canonical type. No access check is
3789 performed during the fixup. PARM_DESC is a TREE_LIST which
3790 TREE_VALUE is the template parameter and its TREE_PURPOSE is the
3791 default argument of the template parm if any. IDX is the index of
3792 the template parameter, starting at 0. NUM_PARMS is the number of
3793 template parameters in the set PARM_DESC belongs to. ARGLIST is a
3794 TREE_VEC containing the full set of template parameters in a form
3795 suitable to be passed to substs functions as their ARGS
3796 argument. This is what current_template_args returns for a given
3797 template. The innermost vector of args in ARGLIST is the set of
3798 template parms that have been fixed up so far. This function adds
3799 the fixed up parameter into that vector. */
3802 fixup_template_parm (tree parm_desc,
3807 tree parm = TREE_VALUE (parm_desc);
3808 tree fixedup_args = INNERMOST_TEMPLATE_ARGS (arglist);
3810 push_deferring_access_checks (dk_no_check);
3812 if (TREE_CODE (parm) == TYPE_DECL)
3814 /* PARM is a template type parameter. Fix up its type, add
3815 the fixed-up template parm to the vector of fixed-up
3816 template parms so far, and substitute the fixed-up
3817 template parms into the default argument of this
3820 fixup_template_type_parm_type (TREE_TYPE (parm), num_parms);
3821 TREE_TYPE (parm) = t;
3823 TREE_VEC_ELT (fixedup_args, idx) = template_parm_to_arg (parm_desc);
3825 else if (TREE_CODE (parm) == TEMPLATE_DECL)
3827 /* PARM is a template template parameter. This is going to
3829 tree tparms, targs, innermost_args, t;
3832 /* First, fix up the parms of the template template parm
3833 because the parms are involved in defining the new canonical
3834 type of the template template parm. */
3836 /* So we need to substitute the template parm types that have
3837 been fixed up so far into the template parms of this template
3838 template parm. E.g, consider this:
3840 template<class T, template<T u> class TT> class S;
3842 In this case we want to substitute T into the
3843 template parameters of TT.
3845 So let's walk the template parms of PARM here, and
3846 tsubst ARGLIST into into each of the template
3849 /* For this substitution we need to build the full set of
3850 template parameters and use that as arguments for the
3851 tsubsting function. */
3852 tparms = INNERMOST_TEMPLATE_PARMS (DECL_TEMPLATE_PARMS (parm));
3854 /* This will contain the innermost parms of PARM into which
3855 we have substituted so far. */
3856 innermost_args = make_tree_vec (TREE_VEC_LENGTH (tparms));
3857 targs = add_to_template_args (arglist, innermost_args);
3858 for (j = 0; j < TREE_VEC_LENGTH (tparms); ++j)
3862 parameter = TREE_VEC_ELT (tparms, j);
3864 /* INNERMOST_ARGS needs to have at least the same number
3865 of elements as the index PARAMETER, ortherwise
3866 tsubsting into PARAMETER will result in partially
3867 instantiating it, reducing its tempate parm
3868 level. Let's tactically fill INNERMOST_ARGS for that
3870 TREE_VEC_ELT (innermost_args, j) =
3871 template_parm_to_arg (parameter);
3873 fixup_template_parm (parameter, j,
3874 TREE_VEC_LENGTH (tparms),
3878 /* Now fix up the type of the template template parm. */
3880 t = fixup_template_type_parm_type (TREE_TYPE (parm), num_parms);
3881 TREE_TYPE (parm) = t;
3883 TREE_VEC_ELT (fixedup_args, idx) =
3884 template_parm_to_arg (parm_desc);
3886 else if (TREE_CODE (parm) == PARM_DECL)
3888 /* PARM is a non-type template parameter. We need to:
3890 * Fix up its TEMPLATE_PARM_INDEX to make it carry the
3891 proper number of sibling parameters.
3893 * Make lookups of the template parameter return a reference
3894 to the fixed-up index. No lookup should return references
3895 to the former index anymore.
3897 * Substitute the template parms that got fixed up so far
3899 * into the type of PARM. */
3901 tree index = DECL_INITIAL (parm);
3903 /* PUSHED_DECL is the decl added to the symbol table with
3904 the name of the parameter. E,g:
3906 template<class T, T u> //#0
3907 auto my_function(T t) -> decltype(u); //#1
3909 Here, when looking up u at //#1, we get the decl of u
3910 resulting from the declaration in #0. This is what
3911 PUSHED_DECL is. We need to replace the reference to the
3912 old TEMPLATE_PARM_INDEX carried by PUSHED_DECL by the
3913 fixed-up TEMPLATE_PARM_INDEX. */
3914 tree pushed_decl = TEMPLATE_PARM_DECL (index);
3916 /* Let's fix up the TEMPLATE_PARM_INDEX then. Note that we must
3917 fixup the type of PUSHED_DECL as well and luckily
3918 fixup_template_parm_index does it for us too. */
3919 tree fixed_up_index =
3920 fixup_template_parm_index (index, arglist, num_parms);
3922 DECL_INITIAL (pushed_decl) = DECL_INITIAL (parm) = fixed_up_index;
3924 /* Add this fixed up PARM to the template parms we've fixed
3925 up so far and use that to substitute the fixed-up
3926 template parms into the type of PARM. */
3927 TREE_VEC_ELT (fixedup_args, idx) =
3928 template_parm_to_arg (parm_desc);
3929 TREE_TYPE (parm) = tsubst (TREE_TYPE (parm), arglist,
3930 tf_none, NULL_TREE);
3933 TREE_PURPOSE (parm_desc) =
3934 tsubst_template_arg (TREE_PURPOSE (parm_desc),
3935 arglist, tf_none, parm);
3937 pop_deferring_access_checks ();
3940 /* Walk the current template parms and properly compute the canonical
3941 types of the dependent types created during
3942 cp_parser_template_parameter_list. */
3945 fixup_template_parms (void)
3952 parameter_vec = INNERMOST_TEMPLATE_PARMS (current_template_parms);
3953 if (parameter_vec == NULL_TREE)
3956 num_parms = TREE_VEC_LENGTH (parameter_vec);
3958 /* This vector contains the current innermost template parms that
3959 have been fixed up so far. The form of FIXEDUP_ARGS is suitable
3960 to be passed to tsubst* functions as their ARGS argument. */
3961 fixedup_args = make_tree_vec (num_parms);
3963 /* This vector contains the full set of template parms in a form
3964 suitable to be passed to substs functions as their ARGS
3966 arglist = current_template_args ();
3967 arglist = add_outermost_template_args (arglist, fixedup_args);
3969 /* Let's do the proper fixup now. */
3970 for (i = 0; i < num_parms; ++i)
3971 fixup_template_parm (TREE_VEC_ELT (parameter_vec, i),
3972 i, num_parms, arglist);
3975 /* end_template_decl is called after a template declaration is seen. */
3978 end_template_decl (void)
3980 reset_specialization ();
3982 if (! processing_template_decl)
3985 /* This matches the pushlevel in begin_template_parm_list. */
3988 --processing_template_decl;
3989 current_template_parms = TREE_CHAIN (current_template_parms);
3992 /* Takes a TREE_LIST representing a template parameter and convert it
3993 into an argument suitable to be passed to the type substitution
3994 functions. Note that If the TREE_LIST contains an error_mark
3995 node, the returned argument is error_mark_node. */
3998 template_parm_to_arg (tree t)
4002 || TREE_CODE (t) != TREE_LIST)
4005 if (error_operand_p (TREE_VALUE (t)))
4006 return error_mark_node;
4010 if (TREE_CODE (t) == TYPE_DECL
4011 || TREE_CODE (t) == TEMPLATE_DECL)
4015 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
4017 /* Turn this argument into a TYPE_ARGUMENT_PACK
4018 with a single element, which expands T. */
4019 tree vec = make_tree_vec (1);
4020 #ifdef ENABLE_CHECKING
4021 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
4022 (vec, TREE_VEC_LENGTH (vec));
4024 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
4026 t = cxx_make_type (TYPE_ARGUMENT_PACK);
4027 SET_ARGUMENT_PACK_ARGS (t, vec);
4032 t = DECL_INITIAL (t);
4034 if (TEMPLATE_PARM_PARAMETER_PACK (t))
4036 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
4037 with a single element, which expands T. */
4038 tree vec = make_tree_vec (1);
4039 tree type = TREE_TYPE (TEMPLATE_PARM_DECL (t));
4040 #ifdef ENABLE_CHECKING
4041 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
4042 (vec, TREE_VEC_LENGTH (vec));
4044 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
4046 t = make_node (NONTYPE_ARGUMENT_PACK);
4047 SET_ARGUMENT_PACK_ARGS (t, vec);
4048 TREE_TYPE (t) = type;
4054 /* This function returns TRUE if PARM_PACK is a template parameter
4055 pack and if ARG_PACK is what template_parm_to_arg returned when
4056 passed PARM_PACK. */
4059 arg_from_parm_pack_p (tree arg_pack, tree parm_pack)
4061 /* For clarity in the comments below let's use the representation
4062 argument_pack<elements>' to denote an argument pack and its
4065 In the 'if' block below, we want to detect cases where
4066 ARG_PACK is argument_pack<PARM_PACK...>. I.e, we want to
4067 check if ARG_PACK is an argument pack which sole element is
4068 the expansion of PARM_PACK. That argument pack is typically
4069 created by template_parm_to_arg when passed a parameter
4073 && TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack)) == 1
4074 && PACK_EXPANSION_P (TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0)))
4076 tree expansion = TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0);
4077 tree pattern = PACK_EXPANSION_PATTERN (expansion);
4078 /* So we have an argument_pack<P...>. We want to test if P
4079 is actually PARM_PACK. We will not use cp_tree_equal to
4080 test P and PARM_PACK because during type fixup (by
4081 fixup_template_parm) P can be a pre-fixup version of a
4082 type and PARM_PACK be its post-fixup version.
4083 cp_tree_equal would consider them as different even
4084 though we would want to consider them compatible for our
4085 precise purpose here.
4087 Thus we are going to consider that P and PARM_PACK are
4088 compatible if they have the same DECL. */
4089 if ((/* If ARG_PACK is a type parameter pack named by the
4090 same DECL as parm_pack ... */
4092 && TYPE_P (parm_pack)
4093 && TYPE_NAME (pattern) == TYPE_NAME (parm_pack))
4094 /* ... or if PARM_PACK is a non-type parameter named by the
4095 same DECL as ARG_PACK. Note that PARM_PACK being a
4096 non-type parameter means it's either a PARM_DECL or a
4097 TEMPLATE_PARM_INDEX. */
4098 || (TREE_CODE (pattern) == TEMPLATE_PARM_INDEX
4099 && ((TREE_CODE (parm_pack) == PARM_DECL
4100 && (TEMPLATE_PARM_DECL (pattern)
4101 == TEMPLATE_PARM_DECL (DECL_INITIAL (parm_pack))))
4102 || (TREE_CODE (parm_pack) == TEMPLATE_PARM_INDEX
4103 && (TEMPLATE_PARM_DECL (pattern)
4104 == TEMPLATE_PARM_DECL (parm_pack))))))
4105 && template_parameter_pack_p (pattern))
4111 /* Within the declaration of a template, return all levels of template
4112 parameters that apply. The template parameters are represented as
4113 a TREE_VEC, in the form documented in cp-tree.h for template
4117 current_template_args (void)
4120 tree args = NULL_TREE;
4121 int length = TMPL_PARMS_DEPTH (current_template_parms);
4124 /* If there is only one level of template parameters, we do not
4125 create a TREE_VEC of TREE_VECs. Instead, we return a single
4126 TREE_VEC containing the arguments. */
4128 args = make_tree_vec (length);
4130 for (header = current_template_parms; header; header = TREE_CHAIN (header))
4132 tree a = copy_node (TREE_VALUE (header));
4135 TREE_TYPE (a) = NULL_TREE;
4136 for (i = TREE_VEC_LENGTH (a) - 1; i >= 0; --i)
4137 TREE_VEC_ELT (a, i) = template_parm_to_arg (TREE_VEC_ELT (a, i));
4139 #ifdef ENABLE_CHECKING
4140 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (a, TREE_VEC_LENGTH (a));
4144 TREE_VEC_ELT (args, --l) = a;
4149 if (length > 1 && TREE_VEC_ELT (args, 0) == NULL_TREE)
4150 /* This can happen for template parms of a template template
4153 template<template<class T, class U> class TT> struct S;
4155 Consider the level of the parms of TT; T and U both have
4156 level 2; TT has no template parm of level 1. So in this case
4157 the first element of full_template_args is NULL_TREE. If we
4158 leave it like this TMPL_ARG_DEPTH on args returns 1 instead
4159 of 2. This will make tsubst wrongly consider that T and U
4160 have level 1. Instead, let's create a dummy vector as the
4161 first element of full_template_args so that TMPL_ARG_DEPTH
4162 returns the correct depth for args. */
4163 TREE_VEC_ELT (args, 0) = make_tree_vec (1);
4167 /* Update the declared TYPE by doing any lookups which were thought to be
4168 dependent, but are not now that we know the SCOPE of the declarator. */
4171 maybe_update_decl_type (tree orig_type, tree scope)
4173 tree type = orig_type;
4175 if (type == NULL_TREE)
4178 if (TREE_CODE (orig_type) == TYPE_DECL)
4179 type = TREE_TYPE (type);
4181 if (scope && TYPE_P (scope) && dependent_type_p (scope)
4182 && dependent_type_p (type)
4183 /* Don't bother building up the args in this case. */
4184 && TREE_CODE (type) != TEMPLATE_TYPE_PARM)
4186 /* tsubst in the args corresponding to the template parameters,
4187 including auto if present. Most things will be unchanged, but
4188 make_typename_type and tsubst_qualified_id will resolve
4189 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4190 tree args = current_template_args ();
4191 tree auto_node = type_uses_auto (type);
4195 tree auto_vec = make_tree_vec (1);
4196 TREE_VEC_ELT (auto_vec, 0) = auto_node;
4197 args = add_to_template_args (args, auto_vec);
4199 pushed = push_scope (scope);
4200 type = tsubst (type, args, tf_warning_or_error, NULL_TREE);
4205 if (type == error_mark_node)
4208 if (TREE_CODE (orig_type) == TYPE_DECL)
4210 if (same_type_p (type, TREE_TYPE (orig_type)))
4213 type = TYPE_NAME (type);
4218 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4219 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
4220 a member template. Used by push_template_decl below. */
4223 build_template_decl (tree decl, tree parms, bool member_template_p)
4225 tree tmpl = build_lang_decl (TEMPLATE_DECL, DECL_NAME (decl), NULL_TREE);
4226 DECL_TEMPLATE_PARMS (tmpl) = parms;
4227 DECL_CONTEXT (tmpl) = DECL_CONTEXT (decl);
4228 DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl);
4229 DECL_MEMBER_TEMPLATE_P (tmpl) = member_template_p;
4234 struct template_parm_data
4236 /* The level of the template parameters we are currently
4240 /* The index of the specialization argument we are currently
4244 /* An array whose size is the number of template parameters. The
4245 elements are nonzero if the parameter has been used in any one
4246 of the arguments processed so far. */
4249 /* An array whose size is the number of template arguments. The
4250 elements are nonzero if the argument makes use of template
4251 parameters of this level. */
4252 int* arg_uses_template_parms;
4255 /* Subroutine of push_template_decl used to see if each template
4256 parameter in a partial specialization is used in the explicit
4257 argument list. If T is of the LEVEL given in DATA (which is
4258 treated as a template_parm_data*), then DATA->PARMS is marked
4262 mark_template_parm (tree t, void* data)
4266 struct template_parm_data* tpd = (struct template_parm_data*) data;
4268 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
4270 level = TEMPLATE_PARM_LEVEL (t);
4271 idx = TEMPLATE_PARM_IDX (t);
4275 level = TEMPLATE_TYPE_LEVEL (t);
4276 idx = TEMPLATE_TYPE_IDX (t);
4279 if (level == tpd->level)
4281 tpd->parms[idx] = 1;
4282 tpd->arg_uses_template_parms[tpd->current_arg] = 1;
4285 /* Return zero so that for_each_template_parm will continue the
4286 traversal of the tree; we want to mark *every* template parm. */
4290 /* Process the partial specialization DECL. */
4293 process_partial_specialization (tree decl)
4295 tree type = TREE_TYPE (decl);
4296 tree maintmpl = CLASSTYPE_TI_TEMPLATE (type);
4297 tree specargs = CLASSTYPE_TI_ARGS (type);
4298 tree inner_args = INNERMOST_TEMPLATE_ARGS (specargs);
4299 tree main_inner_parms = DECL_INNERMOST_TEMPLATE_PARMS (maintmpl);
4302 int nargs = TREE_VEC_LENGTH (inner_args);
4305 bool did_error_intro = false;
4306 struct template_parm_data tpd;
4307 struct template_parm_data tpd2;
4309 gcc_assert (current_template_parms);
4311 inner_parms = INNERMOST_TEMPLATE_PARMS (current_template_parms);
4312 ntparms = TREE_VEC_LENGTH (inner_parms);
4314 /* We check that each of the template parameters given in the
4315 partial specialization is used in the argument list to the
4316 specialization. For example:
4318 template <class T> struct S;
4319 template <class T> struct S<T*>;
4321 The second declaration is OK because `T*' uses the template
4322 parameter T, whereas
4324 template <class T> struct S<int>;
4326 is no good. Even trickier is:
4337 The S2<T> declaration is actually invalid; it is a
4338 full-specialization. Of course,
4341 struct S2<T (*)(U)>;
4343 or some such would have been OK. */
4344 tpd.level = TMPL_PARMS_DEPTH (current_template_parms);
4345 tpd.parms = XALLOCAVEC (int, ntparms);
4346 memset (tpd.parms, 0, sizeof (int) * ntparms);
4348 tpd.arg_uses_template_parms = XALLOCAVEC (int, nargs);
4349 memset (tpd.arg_uses_template_parms, 0, sizeof (int) * nargs);
4350 for (i = 0; i < nargs; ++i)
4352 tpd.current_arg = i;
4353 for_each_template_parm (TREE_VEC_ELT (inner_args, i),
4354 &mark_template_parm,
4357 /*include_nondeduced_p=*/false);
4359 for (i = 0; i < ntparms; ++i)
4360 if (tpd.parms[i] == 0)
4362 /* One of the template parms was not used in the
4364 if (!did_error_intro)
4366 error ("template parameters not used in partial specialization:");
4367 did_error_intro = true;
4370 error (" %qD", TREE_VALUE (TREE_VEC_ELT (inner_parms, i)));
4373 if (did_error_intro)
4374 return error_mark_node;
4376 /* [temp.class.spec]
4378 The argument list of the specialization shall not be identical to
4379 the implicit argument list of the primary template. */
4380 if (comp_template_args
4382 INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE
4384 error ("partial specialization %qT does not specialize any template arguments", type);
4386 /* [temp.class.spec]
4388 A partially specialized non-type argument expression shall not
4389 involve template parameters of the partial specialization except
4390 when the argument expression is a simple identifier.
4392 The type of a template parameter corresponding to a specialized
4393 non-type argument shall not be dependent on a parameter of the
4396 Also, we verify that pack expansions only occur at the
4397 end of the argument list. */
4398 gcc_assert (nargs == DECL_NTPARMS (maintmpl));
4400 for (i = 0; i < nargs; ++i)
4402 tree parm = TREE_VALUE (TREE_VEC_ELT (main_inner_parms, i));
4403 tree arg = TREE_VEC_ELT (inner_args, i);
4404 tree packed_args = NULL_TREE;
4407 if (ARGUMENT_PACK_P (arg))
4409 /* Extract the arguments from the argument pack. We'll be
4410 iterating over these in the following loop. */
4411 packed_args = ARGUMENT_PACK_ARGS (arg);
4412 len = TREE_VEC_LENGTH (packed_args);
4415 for (j = 0; j < len; j++)
4418 /* Get the Jth argument in the parameter pack. */
4419 arg = TREE_VEC_ELT (packed_args, j);
4421 if (PACK_EXPANSION_P (arg))
4423 /* Pack expansions must come at the end of the
4425 if ((packed_args && j < len - 1)
4426 || (!packed_args && i < nargs - 1))
4428 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
4429 error ("parameter pack argument %qE must be at the "
4430 "end of the template argument list", arg);
4432 error ("parameter pack argument %qT must be at the "
4433 "end of the template argument list", arg);
4437 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
4438 /* We only care about the pattern. */
4439 arg = PACK_EXPANSION_PATTERN (arg);
4441 if (/* These first two lines are the `non-type' bit. */
4443 && TREE_CODE (arg) != TEMPLATE_DECL
4444 /* This next line is the `argument expression is not just a
4445 simple identifier' condition and also the `specialized
4446 non-type argument' bit. */
4447 && TREE_CODE (arg) != TEMPLATE_PARM_INDEX)
4449 if ((!packed_args && tpd.arg_uses_template_parms[i])
4450 || (packed_args && uses_template_parms (arg)))
4451 error ("template argument %qE involves template parameter(s)",
4455 /* Look at the corresponding template parameter,
4456 marking which template parameters its type depends
4458 tree type = TREE_TYPE (parm);
4462 /* We haven't yet initialized TPD2. Do so now. */
4463 tpd2.arg_uses_template_parms = XALLOCAVEC (int, nargs);
4464 /* The number of parameters here is the number in the
4465 main template, which, as checked in the assertion
4467 tpd2.parms = XALLOCAVEC (int, nargs);
4469 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (maintmpl));
4472 /* Mark the template parameters. But this time, we're
4473 looking for the template parameters of the main
4474 template, not in the specialization. */
4475 tpd2.current_arg = i;
4476 tpd2.arg_uses_template_parms[i] = 0;
4477 memset (tpd2.parms, 0, sizeof (int) * nargs);
4478 for_each_template_parm (type,
4479 &mark_template_parm,
4482 /*include_nondeduced_p=*/false);
4484 if (tpd2.arg_uses_template_parms [i])
4486 /* The type depended on some template parameters.
4487 If they are fully specialized in the
4488 specialization, that's OK. */
4491 for (j = 0; j < nargs; ++j)
4492 if (tpd2.parms[j] != 0
4493 && tpd.arg_uses_template_parms [j])
4496 error_n (input_location, count,
4497 "type %qT of template argument %qE depends "
4498 "on a template parameter",
4499 "type %qT of template argument %qE depends "
4500 "on template parameters",
4509 /* We should only get here once. */
4510 gcc_assert (!COMPLETE_TYPE_P (type));
4512 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)
4513 = tree_cons (specargs, inner_parms,
4514 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl));
4515 TREE_TYPE (DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)) = type;
4517 for (inst = DECL_TEMPLATE_INSTANTIATIONS (maintmpl); inst;
4518 inst = TREE_CHAIN (inst))
4520 tree inst_type = TREE_VALUE (inst);
4521 if (COMPLETE_TYPE_P (inst_type)
4522 && CLASSTYPE_IMPLICIT_INSTANTIATION (inst_type))
4524 tree spec = most_specialized_class (inst_type, maintmpl, tf_none);
4525 if (spec && TREE_TYPE (spec) == type)
4526 permerror (input_location,
4527 "partial specialization of %qT after instantiation "
4528 "of %qT", type, inst_type);
4535 /* Check that a template declaration's use of default arguments and
4536 parameter packs is not invalid. Here, PARMS are the template
4537 parameters. IS_PRIMARY is nonzero if DECL is the thing declared by
4538 a primary template. IS_PARTIAL is nonzero if DECL is a partial
4542 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4543 declaration (but not a definition); 1 indicates a declaration, 2
4544 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4545 emitted for extraneous default arguments.
4547 Returns TRUE if there were no errors found, FALSE otherwise. */
4550 check_default_tmpl_args (tree decl, tree parms, int is_primary,
4551 int is_partial, int is_friend_decl)
4554 int last_level_to_check;
4556 bool no_errors = true;
4560 A default template-argument shall not be specified in a
4561 function template declaration or a function template definition, nor
4562 in the template-parameter-list of the definition of a member of a
4565 if (TREE_CODE (CP_DECL_CONTEXT (decl)) == FUNCTION_DECL)
4566 /* You can't have a function template declaration in a local
4567 scope, nor you can you define a member of a class template in a
4571 if (current_class_type
4572 && !TYPE_BEING_DEFINED (current_class_type)
4573 && DECL_LANG_SPECIFIC (decl)
4574 && DECL_DECLARES_FUNCTION_P (decl)
4575 /* If this is either a friend defined in the scope of the class
4576 or a member function. */
4577 && (DECL_FUNCTION_MEMBER_P (decl)
4578 ? same_type_p (DECL_CONTEXT (decl), current_class_type)
4579 : DECL_FRIEND_CONTEXT (decl)
4580 ? same_type_p (DECL_FRIEND_CONTEXT (decl), current_class_type)
4582 /* And, if it was a member function, it really was defined in
4583 the scope of the class. */
4584 && (!DECL_FUNCTION_MEMBER_P (decl)
4585 || DECL_INITIALIZED_IN_CLASS_P (decl)))
4586 /* We already checked these parameters when the template was
4587 declared, so there's no need to do it again now. This function
4588 was defined in class scope, but we're processing it's body now
4589 that the class is complete. */
4592 /* Core issue 226 (C++0x only): the following only applies to class
4594 if ((cxx_dialect == cxx98) || TREE_CODE (decl) != FUNCTION_DECL)
4598 If a template-parameter has a default template-argument, all
4599 subsequent template-parameters shall have a default
4600 template-argument supplied. */
4601 for (parm_level = parms; parm_level; parm_level = TREE_CHAIN (parm_level))
4603 tree inner_parms = TREE_VALUE (parm_level);
4604 int ntparms = TREE_VEC_LENGTH (inner_parms);
4605 int seen_def_arg_p = 0;
4608 for (i = 0; i < ntparms; ++i)
4610 tree parm = TREE_VEC_ELT (inner_parms, i);
4612 if (parm == error_mark_node)
4615 if (TREE_PURPOSE (parm))
4617 else if (seen_def_arg_p
4618 && !template_parameter_pack_p (TREE_VALUE (parm)))
4620 error ("no default argument for %qD", TREE_VALUE (parm));
4621 /* For better subsequent error-recovery, we indicate that
4622 there should have been a default argument. */
4623 TREE_PURPOSE (parm) = error_mark_node;
4629 /* Don't complain about an enclosing partial
4631 && parm_level == parms
4632 && TREE_CODE (decl) == TYPE_DECL
4634 && template_parameter_pack_p (TREE_VALUE (parm)))
4636 /* A primary class template can only have one
4637 parameter pack, at the end of the template
4640 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL)
4641 error ("parameter pack %qE must be at the end of the"
4642 " template parameter list", TREE_VALUE (parm));
4644 error ("parameter pack %qT must be at the end of the"
4645 " template parameter list",
4646 TREE_TYPE (TREE_VALUE (parm)));
4648 TREE_VALUE (TREE_VEC_ELT (inner_parms, i))
4656 if (((cxx_dialect == cxx98) && TREE_CODE (decl) != TYPE_DECL)
4660 /* For an ordinary class template, default template arguments are
4661 allowed at the innermost level, e.g.:
4662 template <class T = int>
4664 but, in a partial specialization, they're not allowed even
4665 there, as we have in [temp.class.spec]:
4667 The template parameter list of a specialization shall not
4668 contain default template argument values.
4670 So, for a partial specialization, or for a function template
4671 (in C++98/C++03), we look at all of them. */
4674 /* But, for a primary class template that is not a partial
4675 specialization we look at all template parameters except the
4677 parms = TREE_CHAIN (parms);
4679 /* Figure out what error message to issue. */
4680 if (is_friend_decl == 2)
4681 msg = G_("default template arguments may not be used in function template "
4682 "friend re-declaration");
4683 else if (is_friend_decl)
4684 msg = G_("default template arguments may not be used in function template "
4685 "friend declarations");
4686 else if (TREE_CODE (decl) == FUNCTION_DECL && (cxx_dialect == cxx98))
4687 msg = G_("default template arguments may not be used in function templates "
4688 "without -std=c++11 or -std=gnu++11");
4689 else if (is_partial)
4690 msg = G_("default template arguments may not be used in "
4691 "partial specializations");
4693 msg = G_("default argument for template parameter for class enclosing %qD");
4695 if (current_class_type && TYPE_BEING_DEFINED (current_class_type))
4696 /* If we're inside a class definition, there's no need to
4697 examine the parameters to the class itself. On the one
4698 hand, they will be checked when the class is defined, and,
4699 on the other, default arguments are valid in things like:
4700 template <class T = double>
4701 struct S { template <class U> void f(U); };
4702 Here the default argument for `S' has no bearing on the
4703 declaration of `f'. */
4704 last_level_to_check = template_class_depth (current_class_type) + 1;
4706 /* Check everything. */
4707 last_level_to_check = 0;
4709 for (parm_level = parms;
4710 parm_level && TMPL_PARMS_DEPTH (parm_level) >= last_level_to_check;
4711 parm_level = TREE_CHAIN (parm_level))
4713 tree inner_parms = TREE_VALUE (parm_level);
4717 ntparms = TREE_VEC_LENGTH (inner_parms);
4718 for (i = 0; i < ntparms; ++i)
4720 if (TREE_VEC_ELT (inner_parms, i) == error_mark_node)
4723 if (TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)))
4728 if (is_friend_decl == 2)
4735 /* Clear out the default argument so that we are not
4737 TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)) = NULL_TREE;
4741 /* At this point, if we're still interested in issuing messages,
4742 they must apply to classes surrounding the object declared. */
4744 msg = G_("default argument for template parameter for class "
4751 /* Worker for push_template_decl_real, called via
4752 for_each_template_parm. DATA is really an int, indicating the
4753 level of the parameters we are interested in. If T is a template
4754 parameter of that level, return nonzero. */
4757 template_parm_this_level_p (tree t, void* data)
4759 int this_level = *(int *)data;
4762 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
4763 level = TEMPLATE_PARM_LEVEL (t);
4765 level = TEMPLATE_TYPE_LEVEL (t);
4766 return level == this_level;
4769 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4770 parameters given by current_template_args, or reuses a
4771 previously existing one, if appropriate. Returns the DECL, or an
4772 equivalent one, if it is replaced via a call to duplicate_decls.
4774 If IS_FRIEND is true, DECL is a friend declaration. */
4777 push_template_decl_real (tree decl, bool is_friend)
4785 int new_template_p = 0;
4786 /* True if the template is a member template, in the sense of
4788 bool member_template_p = false;
4790 if (decl == error_mark_node || !current_template_parms)
4791 return error_mark_node;
4793 /* See if this is a partial specialization. */
4794 is_partial = (DECL_IMPLICIT_TYPEDEF_P (decl)
4795 && TREE_CODE (TREE_TYPE (decl)) != ENUMERAL_TYPE
4796 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)));
4798 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_FRIEND_P (decl))
4802 /* For a friend, we want the context of the friend function, not
4803 the type of which it is a friend. */
4804 ctx = CP_DECL_CONTEXT (decl);
4805 else if (CP_DECL_CONTEXT (decl)
4806 && TREE_CODE (CP_DECL_CONTEXT (decl)) != NAMESPACE_DECL)
4807 /* In the case of a virtual function, we want the class in which
4809 ctx = CP_DECL_CONTEXT (decl);
4811 /* Otherwise, if we're currently defining some class, the DECL
4812 is assumed to be a member of the class. */
4813 ctx = current_scope ();
4815 if (ctx && TREE_CODE (ctx) == NAMESPACE_DECL)
4818 if (!DECL_CONTEXT (decl))
4819 DECL_CONTEXT (decl) = FROB_CONTEXT (current_namespace);
4821 /* See if this is a primary template. */
4822 if (is_friend && ctx)
4823 /* A friend template that specifies a class context, i.e.
4824 template <typename T> friend void A<T>::f();
4828 primary = template_parm_scope_p ();
4832 if (DECL_CLASS_SCOPE_P (decl))
4833 member_template_p = true;
4834 if (TREE_CODE (decl) == TYPE_DECL
4835 && ANON_AGGRNAME_P (DECL_NAME (decl)))
4837 error ("template class without a name");
4838 return error_mark_node;
4840 else if (TREE_CODE (decl) == FUNCTION_DECL)
4842 if (DECL_DESTRUCTOR_P (decl))
4846 A destructor shall not be a member template. */
4847 error ("destructor %qD declared as member template", decl);
4848 return error_mark_node;
4850 if (NEW_DELETE_OPNAME_P (DECL_NAME (decl))
4851 && (!prototype_p (TREE_TYPE (decl))
4852 || TYPE_ARG_TYPES (TREE_TYPE (decl)) == void_list_node
4853 || !TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (decl)))
4854 || (TREE_CHAIN (TYPE_ARG_TYPES ((TREE_TYPE (decl))))
4855 == void_list_node)))
4857 /* [basic.stc.dynamic.allocation]
4859 An allocation function can be a function
4860 template. ... Template allocation functions shall
4861 have two or more parameters. */
4862 error ("invalid template declaration of %qD", decl);
4863 return error_mark_node;
4866 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4867 && CLASS_TYPE_P (TREE_TYPE (decl)))
4869 else if (TREE_CODE (decl) == TYPE_DECL
4870 && TYPE_DECL_ALIAS_P (decl))
4871 /* alias-declaration */
4872 gcc_assert (!DECL_ARTIFICIAL (decl));
4875 error ("template declaration of %q#D", decl);
4876 return error_mark_node;
4880 /* Check to see that the rules regarding the use of default
4881 arguments are not being violated. */
4882 check_default_tmpl_args (decl, current_template_parms,
4883 primary, is_partial, /*is_friend_decl=*/0);
4885 /* Ensure that there are no parameter packs in the type of this
4886 declaration that have not been expanded. */
4887 if (TREE_CODE (decl) == FUNCTION_DECL)
4889 /* Check each of the arguments individually to see if there are
4890 any bare parameter packs. */
4891 tree type = TREE_TYPE (decl);
4892 tree arg = DECL_ARGUMENTS (decl);
4893 tree argtype = TYPE_ARG_TYPES (type);
4895 while (arg && argtype)
4897 if (!FUNCTION_PARAMETER_PACK_P (arg)
4898 && check_for_bare_parameter_packs (TREE_TYPE (arg)))
4900 /* This is a PARM_DECL that contains unexpanded parameter
4901 packs. We have already complained about this in the
4902 check_for_bare_parameter_packs call, so just replace
4903 these types with ERROR_MARK_NODE. */
4904 TREE_TYPE (arg) = error_mark_node;
4905 TREE_VALUE (argtype) = error_mark_node;
4908 arg = DECL_CHAIN (arg);
4909 argtype = TREE_CHAIN (argtype);
4912 /* Check for bare parameter packs in the return type and the
4913 exception specifiers. */
4914 if (check_for_bare_parameter_packs (TREE_TYPE (type)))
4915 /* Errors were already issued, set return type to int
4916 as the frontend doesn't expect error_mark_node as
4918 TREE_TYPE (type) = integer_type_node;
4919 if (check_for_bare_parameter_packs (TYPE_RAISES_EXCEPTIONS (type)))
4920 TYPE_RAISES_EXCEPTIONS (type) = NULL_TREE;
4922 else if (check_for_bare_parameter_packs ((TREE_CODE (decl) == TYPE_DECL
4923 && TYPE_DECL_ALIAS_P (decl))
4924 ? DECL_ORIGINAL_TYPE (decl)
4925 : TREE_TYPE (decl)))
4927 TREE_TYPE (decl) = error_mark_node;
4928 return error_mark_node;
4932 return process_partial_specialization (decl);
4934 args = current_template_args ();
4937 || TREE_CODE (ctx) == FUNCTION_DECL
4938 || (CLASS_TYPE_P (ctx) && TYPE_BEING_DEFINED (ctx))
4939 || (is_friend && !DECL_TEMPLATE_INFO (decl)))
4941 if (DECL_LANG_SPECIFIC (decl)
4942 && DECL_TEMPLATE_INFO (decl)
4943 && DECL_TI_TEMPLATE (decl))
4944 tmpl = DECL_TI_TEMPLATE (decl);
4945 /* If DECL is a TYPE_DECL for a class-template, then there won't
4946 be DECL_LANG_SPECIFIC. The information equivalent to
4947 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4948 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4949 && TYPE_TEMPLATE_INFO (TREE_TYPE (decl))
4950 && TYPE_TI_TEMPLATE (TREE_TYPE (decl)))
4952 /* Since a template declaration already existed for this
4953 class-type, we must be redeclaring it here. Make sure
4954 that the redeclaration is valid. */
4955 redeclare_class_template (TREE_TYPE (decl),
4956 current_template_parms);
4957 /* We don't need to create a new TEMPLATE_DECL; just use the
4958 one we already had. */
4959 tmpl = TYPE_TI_TEMPLATE (TREE_TYPE (decl));
4963 tmpl = build_template_decl (decl, current_template_parms,
4967 if (DECL_LANG_SPECIFIC (decl)
4968 && DECL_TEMPLATE_SPECIALIZATION (decl))
4970 /* A specialization of a member template of a template
4972 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
4973 DECL_TEMPLATE_INFO (tmpl) = DECL_TEMPLATE_INFO (decl);
4974 DECL_TEMPLATE_INFO (decl) = NULL_TREE;
4980 tree a, t, current, parms;
4982 tree tinfo = get_template_info (decl);
4986 error ("template definition of non-template %q#D", decl);
4987 return error_mark_node;
4990 tmpl = TI_TEMPLATE (tinfo);
4992 if (DECL_FUNCTION_TEMPLATE_P (tmpl)
4993 && DECL_TEMPLATE_INFO (decl) && DECL_TI_ARGS (decl)
4994 && DECL_TEMPLATE_SPECIALIZATION (decl)
4995 && DECL_MEMBER_TEMPLATE_P (tmpl))
4999 /* The declaration is a specialization of a member
5000 template, declared outside the class. Therefore, the
5001 innermost template arguments will be NULL, so we
5002 replace them with the arguments determined by the
5003 earlier call to check_explicit_specialization. */
5004 args = DECL_TI_ARGS (decl);
5007 = build_template_decl (decl, current_template_parms,
5009 DECL_TEMPLATE_RESULT (new_tmpl) = decl;
5010 TREE_TYPE (new_tmpl) = TREE_TYPE (decl);
5011 DECL_TI_TEMPLATE (decl) = new_tmpl;
5012 SET_DECL_TEMPLATE_SPECIALIZATION (new_tmpl);
5013 DECL_TEMPLATE_INFO (new_tmpl)
5014 = build_template_info (tmpl, args);
5016 register_specialization (new_tmpl,
5017 most_general_template (tmpl),
5023 /* Make sure the template headers we got make sense. */
5025 parms = DECL_TEMPLATE_PARMS (tmpl);
5026 i = TMPL_PARMS_DEPTH (parms);
5027 if (TMPL_ARGS_DEPTH (args) != i)
5029 error ("expected %d levels of template parms for %q#D, got %d",
5030 i, decl, TMPL_ARGS_DEPTH (args));
5033 for (current = decl; i > 0; --i, parms = TREE_CHAIN (parms))
5035 a = TMPL_ARGS_LEVEL (args, i);
5036 t = INNERMOST_TEMPLATE_PARMS (parms);
5038 if (TREE_VEC_LENGTH (t) != TREE_VEC_LENGTH (a))
5040 if (current == decl)
5041 error ("got %d template parameters for %q#D",
5042 TREE_VEC_LENGTH (a), decl);
5044 error ("got %d template parameters for %q#T",
5045 TREE_VEC_LENGTH (a), current);
5046 error (" but %d required", TREE_VEC_LENGTH (t));
5047 return error_mark_node;
5050 if (current == decl)
5052 else if (current == NULL_TREE)
5053 /* Can happen in erroneous input. */
5056 current = (TYPE_P (current)
5057 ? TYPE_CONTEXT (current)
5058 : DECL_CONTEXT (current));
5061 /* Check that the parms are used in the appropriate qualifying scopes
5062 in the declarator. */
5063 if (!comp_template_args
5065 TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (tmpl)))))
5068 template arguments to %qD do not match original template %qD",
5069 decl, DECL_TEMPLATE_RESULT (tmpl));
5070 if (!uses_template_parms (TI_ARGS (tinfo)))
5071 inform (input_location, "use template<> for an explicit specialization");
5072 /* Avoid crash in import_export_decl. */
5073 DECL_INTERFACE_KNOWN (decl) = 1;
5074 return error_mark_node;
5078 DECL_TEMPLATE_RESULT (tmpl) = decl;
5079 TREE_TYPE (tmpl) = TREE_TYPE (decl);
5081 /* Push template declarations for global functions and types. Note
5082 that we do not try to push a global template friend declared in a
5083 template class; such a thing may well depend on the template
5084 parameters of the class. */
5085 if (new_template_p && !ctx
5086 && !(is_friend && template_class_depth (current_class_type) > 0))
5088 tmpl = pushdecl_namespace_level (tmpl, is_friend);
5089 if (tmpl == error_mark_node)
5090 return error_mark_node;
5092 /* Hide template friend classes that haven't been declared yet. */
5093 if (is_friend && TREE_CODE (decl) == TYPE_DECL)
5095 DECL_ANTICIPATED (tmpl) = 1;
5096 DECL_FRIEND_P (tmpl) = 1;
5102 tree parms = DECL_TEMPLATE_PARMS (tmpl);
5105 DECL_PRIMARY_TEMPLATE (tmpl) = tmpl;
5106 if (DECL_CONV_FN_P (tmpl))
5108 int depth = TMPL_PARMS_DEPTH (parms);
5110 /* It is a conversion operator. See if the type converted to
5111 depends on innermost template operands. */
5113 if (uses_template_parms_level (TREE_TYPE (TREE_TYPE (tmpl)),
5115 DECL_TEMPLATE_CONV_FN_P (tmpl) = 1;
5118 /* Give template template parms a DECL_CONTEXT of the template
5119 for which they are a parameter. */
5120 parms = INNERMOST_TEMPLATE_PARMS (parms);
5121 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
5123 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
5124 if (TREE_CODE (parm) == TEMPLATE_DECL)
5125 DECL_CONTEXT (parm) = tmpl;
5129 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5130 back to its most general template. If TMPL is a specialization,
5131 ARGS may only have the innermost set of arguments. Add the missing
5132 argument levels if necessary. */
5133 if (DECL_TEMPLATE_INFO (tmpl))
5134 args = add_outermost_template_args (DECL_TI_ARGS (tmpl), args);
5136 info = build_template_info (tmpl, args);
5138 if (DECL_IMPLICIT_TYPEDEF_P (decl))
5139 SET_TYPE_TEMPLATE_INFO (TREE_TYPE (tmpl), info);
5142 if (primary && !DECL_LANG_SPECIFIC (decl))
5143 retrofit_lang_decl (decl);
5144 if (DECL_LANG_SPECIFIC (decl))
5145 DECL_TEMPLATE_INFO (decl) = info;
5148 return DECL_TEMPLATE_RESULT (tmpl);
5152 push_template_decl (tree decl)
5154 return push_template_decl_real (decl, false);
5157 /* Called when a class template TYPE is redeclared with the indicated
5158 template PARMS, e.g.:
5160 template <class T> struct S;
5161 template <class T> struct S {}; */
5164 redeclare_class_template (tree type, tree parms)
5170 if (!TYPE_TEMPLATE_INFO (type))
5172 error ("%qT is not a template type", type);
5176 tmpl = TYPE_TI_TEMPLATE (type);
5177 if (!PRIMARY_TEMPLATE_P (tmpl))
5178 /* The type is nested in some template class. Nothing to worry
5179 about here; there are no new template parameters for the nested
5185 error ("template specifiers not specified in declaration of %qD",
5190 parms = INNERMOST_TEMPLATE_PARMS (parms);
5191 tmpl_parms = DECL_INNERMOST_TEMPLATE_PARMS (tmpl);
5193 if (TREE_VEC_LENGTH (parms) != TREE_VEC_LENGTH (tmpl_parms))
5195 error_n (input_location, TREE_VEC_LENGTH (parms),
5196 "redeclared with %d template parameter",
5197 "redeclared with %d template parameters",
5198 TREE_VEC_LENGTH (parms));
5199 inform_n (input_location, TREE_VEC_LENGTH (tmpl_parms),
5200 "previous declaration %q+D used %d template parameter",
5201 "previous declaration %q+D used %d template parameters",
5202 tmpl, TREE_VEC_LENGTH (tmpl_parms));
5206 for (i = 0; i < TREE_VEC_LENGTH (tmpl_parms); ++i)
5213 if (TREE_VEC_ELT (tmpl_parms, i) == error_mark_node
5214 || TREE_VEC_ELT (parms, i) == error_mark_node)
5217 tmpl_parm = TREE_VALUE (TREE_VEC_ELT (tmpl_parms, i));
5218 if (tmpl_parm == error_mark_node)
5221 parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
5222 tmpl_default = TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i));
5223 parm_default = TREE_PURPOSE (TREE_VEC_ELT (parms, i));
5225 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5227 if (TREE_CODE (tmpl_parm) != TREE_CODE (parm)
5228 || (TREE_CODE (tmpl_parm) != TYPE_DECL
5229 && !same_type_p (TREE_TYPE (tmpl_parm), TREE_TYPE (parm)))
5230 || (TREE_CODE (tmpl_parm) != PARM_DECL
5231 && (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (tmpl_parm))
5232 != TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm))))
5233 || (TREE_CODE (tmpl_parm) == PARM_DECL
5234 && (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (tmpl_parm))
5235 != TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))))
5237 error ("template parameter %q+#D", tmpl_parm);
5238 error ("redeclared here as %q#D", parm);
5242 if (tmpl_default != NULL_TREE && parm_default != NULL_TREE)
5244 /* We have in [temp.param]:
5246 A template-parameter may not be given default arguments
5247 by two different declarations in the same scope. */
5248 error_at (input_location, "redefinition of default argument for %q#D", parm);
5249 inform (DECL_SOURCE_LOCATION (tmpl_parm),
5250 "original definition appeared here");
5254 if (parm_default != NULL_TREE)
5255 /* Update the previous template parameters (which are the ones
5256 that will really count) with the new default value. */
5257 TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i)) = parm_default;
5258 else if (tmpl_default != NULL_TREE)
5259 /* Update the new parameters, too; they'll be used as the
5260 parameters for any members. */
5261 TREE_PURPOSE (TREE_VEC_ELT (parms, i)) = tmpl_default;
5267 /* Simplify EXPR if it is a non-dependent expression. Returns the
5268 (possibly simplified) expression. */
5271 fold_non_dependent_expr_sfinae (tree expr, tsubst_flags_t complain)
5273 if (expr == NULL_TREE)
5276 /* If we're in a template, but EXPR isn't value dependent, simplify
5277 it. We're supposed to treat:
5279 template <typename T> void f(T[1 + 1]);
5280 template <typename T> void f(T[2]);
5282 as two declarations of the same function, for example. */
5283 if (processing_template_decl
5284 && !type_dependent_expression_p (expr)
5285 && potential_constant_expression (expr)
5286 && !value_dependent_expression_p (expr))
5288 HOST_WIDE_INT saved_processing_template_decl;
5290 saved_processing_template_decl = processing_template_decl;
5291 processing_template_decl = 0;
5292 expr = tsubst_copy_and_build (expr,
5295 /*in_decl=*/NULL_TREE,
5296 /*function_p=*/false,
5297 /*integral_constant_expression_p=*/true);
5298 processing_template_decl = saved_processing_template_decl;
5304 fold_non_dependent_expr (tree expr)
5306 return fold_non_dependent_expr_sfinae (expr, tf_error);
5309 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5310 template declaration, or a TYPE_DECL for an alias declaration. */
5313 alias_type_or_template_p (tree t)
5317 return ((TREE_CODE (t) == TYPE_DECL && TYPE_DECL_ALIAS_P (t))
5320 && TYPE_DECL_ALIAS_P (TYPE_NAME (t)))
5321 || DECL_ALIAS_TEMPLATE_P (t));
5324 /* Return TRUE iff is a specialization of an alias template. */
5327 alias_template_specialization_p (tree t)
5331 return (primary_template_instantiation_p (t)
5332 && DECL_ALIAS_TEMPLATE_P (TYPE_TI_TEMPLATE (t)));
5335 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5336 must be a function or a pointer-to-function type, as specified
5337 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5338 and check that the resulting function has external linkage. */
5341 convert_nontype_argument_function (tree type, tree expr)
5345 linkage_kind linkage;
5347 fn = instantiate_type (type, fns, tf_none);
5348 if (fn == error_mark_node)
5349 return error_mark_node;
5352 if (TREE_CODE (fn_no_ptr) == ADDR_EXPR)
5353 fn_no_ptr = TREE_OPERAND (fn_no_ptr, 0);
5354 if (BASELINK_P (fn_no_ptr))
5355 fn_no_ptr = BASELINK_FUNCTIONS (fn_no_ptr);
5357 /* [temp.arg.nontype]/1
5359 A template-argument for a non-type, non-template template-parameter
5362 -- the address of an object or function with external [C++11: or
5363 internal] linkage. */
5364 linkage = decl_linkage (fn_no_ptr);
5365 if (cxx_dialect >= cxx0x ? linkage == lk_none : linkage != lk_external)
5367 if (cxx_dialect >= cxx0x)
5368 error ("%qE is not a valid template argument for type %qT "
5369 "because %qD has no linkage",
5370 expr, type, fn_no_ptr);
5372 error ("%qE is not a valid template argument for type %qT "
5373 "because %qD does not have external linkage",
5374 expr, type, fn_no_ptr);
5381 /* Subroutine of convert_nontype_argument.
5382 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5383 Emit an error otherwise. */
5386 check_valid_ptrmem_cst_expr (tree type, tree expr,
5387 tsubst_flags_t complain)
5390 if (expr && (null_ptr_cst_p (expr) || TREE_CODE (expr) == PTRMEM_CST))
5392 if (cxx_dialect >= cxx0x && null_member_pointer_value_p (expr))
5394 if (complain & tf_error)
5396 error ("%qE is not a valid template argument for type %qT",
5398 error ("it must be a pointer-to-member of the form %<&X::Y%>");
5403 /* Returns TRUE iff the address of OP is value-dependent.
5405 14.6.2.4 [temp.dep.temp]:
5406 A non-integral non-type template-argument is dependent if its type is
5407 dependent or it has either of the following forms
5410 and contains a nested-name-specifier which specifies a class-name that
5411 names a dependent type.
5413 We generalize this to just say that the address of a member of a
5414 dependent class is value-dependent; the above doesn't cover the
5415 address of a static data member named with an unqualified-id. */
5418 has_value_dependent_address (tree op)
5420 /* We could use get_inner_reference here, but there's no need;
5421 this is only relevant for template non-type arguments, which
5422 can only be expressed as &id-expression. */
5425 tree ctx = CP_DECL_CONTEXT (op);
5426 if (TYPE_P (ctx) && dependent_type_p (ctx))
5433 /* The next set of functions are used for providing helpful explanatory
5434 diagnostics for failed overload resolution. Their messages should be
5435 indented by two spaces for consistency with the messages in
5439 unify_success (bool explain_p ATTRIBUTE_UNUSED)
5445 unify_parameter_deduction_failure (bool explain_p, tree parm)
5448 inform (input_location,
5449 " couldn't deduce template parameter %qD", parm);
5454 unify_invalid (bool explain_p ATTRIBUTE_UNUSED)
5460 unify_cv_qual_mismatch (bool explain_p, tree parm, tree arg)
5463 inform (input_location,
5464 " types %qT and %qT have incompatible cv-qualifiers",
5470 unify_type_mismatch (bool explain_p, tree parm, tree arg)
5473 inform (input_location, " mismatched types %qT and %qT", parm, arg);
5478 unify_parameter_pack_mismatch (bool explain_p, tree parm, tree arg)
5481 inform (input_location,
5482 " template parameter %qD is not a parameter pack, but "
5489 unify_ptrmem_cst_mismatch (bool explain_p, tree parm, tree arg)
5492 inform (input_location,
5493 " template argument %qE does not match "
5494 "pointer-to-member constant %qE",
5500 unify_expression_unequal (bool explain_p, tree parm, tree arg)
5503 inform (input_location, " %qE is not equivalent to %qE", parm, arg);
5508 unify_parameter_pack_inconsistent (bool explain_p, tree old_arg, tree new_arg)
5511 inform (input_location,
5512 " inconsistent parameter pack deduction with %qT and %qT",
5518 unify_inconsistency (bool explain_p, tree parm, tree first, tree second)
5523 inform (input_location,
5524 " deduced conflicting types for parameter %qT (%qT and %qT)",
5525 parm, first, second);
5527 inform (input_location,
5528 " deduced conflicting values for non-type parameter "
5529 "%qE (%qE and %qE)", parm, first, second);
5535 unify_vla_arg (bool explain_p, tree arg)
5538 inform (input_location,
5539 " variable-sized array type %qT is not "
5540 "a valid template argument",
5546 unify_method_type_error (bool explain_p, tree arg)
5549 inform (input_location,
5550 " member function type %qT is not a valid template argument",
5556 unify_arity (bool explain_p, int have, int wanted)
5559 inform_n (input_location, wanted,
5560 " candidate expects %d argument, %d provided",
5561 " candidate expects %d arguments, %d provided",
5567 unify_too_many_arguments (bool explain_p, int have, int wanted)
5569 return unify_arity (explain_p, have, wanted);
5573 unify_too_few_arguments (bool explain_p, int have, int wanted)
5575 return unify_arity (explain_p, have, wanted);
5579 unify_arg_conversion (bool explain_p, tree to_type,
5580 tree from_type, tree arg)
5583 inform (input_location, " cannot convert %qE (type %qT) to type %qT",
5584 arg, from_type, to_type);
5589 unify_no_common_base (bool explain_p, enum template_base_result r,
5590 tree parm, tree arg)
5595 case tbr_ambiguous_baseclass:
5596 inform (input_location, " %qT is an ambiguous base class of %qT",
5600 inform (input_location, " %qT is not derived from %qT", arg, parm);
5607 unify_inconsistent_template_template_parameters (bool explain_p)
5610 inform (input_location,
5611 " template parameters of a template template argument are "
5612 "inconsistent with other deduced template arguments");
5617 unify_template_deduction_failure (bool explain_p, tree parm, tree arg)
5620 inform (input_location,
5621 " can't deduce a template for %qT from non-template type %qT",
5627 unify_template_argument_mismatch (bool explain_p, tree parm, tree arg)
5630 inform (input_location,
5631 " template argument %qE does not match %qD", arg, parm);
5636 unify_overload_resolution_failure (bool explain_p, tree arg)
5639 inform (input_location,
5640 " could not resolve address from overloaded function %qE",
5645 /* Attempt to convert the non-type template parameter EXPR to the
5646 indicated TYPE. If the conversion is successful, return the
5647 converted value. If the conversion is unsuccessful, return
5648 NULL_TREE if we issued an error message, or error_mark_node if we
5649 did not. We issue error messages for out-and-out bad template
5650 parameters, but not simply because the conversion failed, since we
5651 might be just trying to do argument deduction. Both TYPE and EXPR
5652 must be non-dependent.
5654 The conversion follows the special rules described in
5655 [temp.arg.nontype], and it is much more strict than an implicit
5658 This function is called twice for each template argument (see
5659 lookup_template_class for a more accurate description of this
5660 problem). This means that we need to handle expressions which
5661 are not valid in a C++ source, but can be created from the
5662 first call (for instance, casts to perform conversions). These
5663 hacks can go away after we fix the double coercion problem. */
5666 convert_nontype_argument (tree type, tree expr, tsubst_flags_t complain)
5670 /* Detect immediately string literals as invalid non-type argument.
5671 This special-case is not needed for correctness (we would easily
5672 catch this later), but only to provide better diagnostic for this
5673 common user mistake. As suggested by DR 100, we do not mention
5674 linkage issues in the diagnostic as this is not the point. */
5675 /* FIXME we're making this OK. */
5676 if (TREE_CODE (expr) == STRING_CST)
5678 if (complain & tf_error)
5679 error ("%qE is not a valid template argument for type %qT "
5680 "because string literals can never be used in this context",
5685 /* Add the ADDR_EXPR now for the benefit of
5686 value_dependent_expression_p. */
5687 if (TYPE_PTROBV_P (type)
5688 && TREE_CODE (TREE_TYPE (expr)) == ARRAY_TYPE)
5689 expr = decay_conversion (expr);
5691 /* If we are in a template, EXPR may be non-dependent, but still
5692 have a syntactic, rather than semantic, form. For example, EXPR
5693 might be a SCOPE_REF, rather than the VAR_DECL to which the
5694 SCOPE_REF refers. Preserving the qualifying scope is necessary
5695 so that access checking can be performed when the template is
5696 instantiated -- but here we need the resolved form so that we can
5697 convert the argument. */
5698 if (TYPE_REF_OBJ_P (type)
5699 && has_value_dependent_address (expr))
5700 /* If we want the address and it's value-dependent, don't fold. */;
5701 else if (!type_unknown_p (expr))
5702 expr = fold_non_dependent_expr_sfinae (expr, complain);
5703 if (error_operand_p (expr))
5704 return error_mark_node;
5705 expr_type = TREE_TYPE (expr);
5706 if (TREE_CODE (type) == REFERENCE_TYPE)
5707 expr = mark_lvalue_use (expr);
5709 expr = mark_rvalue_use (expr);
5711 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
5712 to a non-type argument of "nullptr". */
5713 if (expr == nullptr_node
5714 && (TYPE_PTR_P (type) || TYPE_PTR_TO_MEMBER_P (type)))
5715 expr = convert (type, expr);
5717 /* In C++11, integral or enumeration non-type template arguments can be
5718 arbitrary constant expressions. Pointer and pointer to
5719 member arguments can be general constant expressions that evaluate
5720 to a null value, but otherwise still need to be of a specific form. */
5721 if (cxx_dialect >= cxx0x)
5723 if (TREE_CODE (expr) == PTRMEM_CST)
5724 /* A PTRMEM_CST is already constant, and a valid template
5725 argument for a parameter of pointer to member type, we just want
5726 to leave it in that form rather than lower it to a
5728 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
5729 expr = maybe_constant_value (expr);
5730 else if (TYPE_PTR_P (type)
5731 || TYPE_PTR_TO_MEMBER_P (type))
5733 tree folded = maybe_constant_value (expr);
5734 if (TYPE_PTR_P (type) ? integer_zerop (folded)
5735 : null_member_pointer_value_p (folded))
5740 /* HACK: Due to double coercion, we can get a
5741 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5742 which is the tree that we built on the first call (see
5743 below when coercing to reference to object or to reference to
5744 function). We just strip everything and get to the arg.
5745 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5747 if (TYPE_REF_OBJ_P (type) || TYPE_REFFN_P (type))
5749 tree probe_type, probe = expr;
5750 if (REFERENCE_REF_P (probe))
5751 probe = TREE_OPERAND (probe, 0);
5752 probe_type = TREE_TYPE (probe);
5753 if (TREE_CODE (probe) == NOP_EXPR)
5755 /* ??? Maybe we could use convert_from_reference here, but we
5756 would need to relax its constraints because the NOP_EXPR
5757 could actually change the type to something more cv-qualified,
5758 and this is not folded by convert_from_reference. */
5759 tree addr = TREE_OPERAND (probe, 0);
5760 gcc_assert (TREE_CODE (probe_type) == REFERENCE_TYPE);
5761 gcc_assert (TREE_CODE (addr) == ADDR_EXPR);
5762 gcc_assert (TREE_CODE (TREE_TYPE (addr)) == POINTER_TYPE);
5763 gcc_assert (same_type_ignoring_top_level_qualifiers_p
5764 (TREE_TYPE (probe_type),
5765 TREE_TYPE (TREE_TYPE (addr))));
5767 expr = TREE_OPERAND (addr, 0);
5768 expr_type = TREE_TYPE (expr);
5772 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5773 parameter is a pointer to object, through decay and
5774 qualification conversion. Let's strip everything. */
5775 else if (TREE_CODE (expr) == NOP_EXPR && TYPE_PTROBV_P (type))
5778 gcc_assert (TREE_CODE (expr) == ADDR_EXPR);
5779 gcc_assert (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE);
5780 /* Skip the ADDR_EXPR only if it is part of the decay for
5781 an array. Otherwise, it is part of the original argument
5782 in the source code. */
5783 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == ARRAY_TYPE)
5784 expr = TREE_OPERAND (expr, 0);
5785 expr_type = TREE_TYPE (expr);
5788 /* [temp.arg.nontype]/5, bullet 1
5790 For a non-type template-parameter of integral or enumeration type,
5791 integral promotions (_conv.prom_) and integral conversions
5792 (_conv.integral_) are applied. */
5793 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
5795 tree t = build_integral_nontype_arg_conv (type, expr, complain);
5796 t = maybe_constant_value (t);
5797 if (t != error_mark_node)
5800 if (!same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (expr)))
5801 return error_mark_node;
5803 /* Notice that there are constant expressions like '4 % 0' which
5804 do not fold into integer constants. */
5805 if (TREE_CODE (expr) != INTEGER_CST)
5807 if (complain & tf_error)
5809 int errs = errorcount, warns = warningcount;
5810 expr = cxx_constant_value (expr);
5811 if (errorcount > errs || warningcount > warns)
5812 inform (EXPR_LOC_OR_HERE (expr),
5813 "in template argument for type %qT ", type);
5814 if (expr == error_mark_node)
5816 /* else cxx_constant_value complained but gave us
5817 a real constant, so go ahead. */
5818 gcc_assert (TREE_CODE (expr) == INTEGER_CST);
5824 /* [temp.arg.nontype]/5, bullet 2
5826 For a non-type template-parameter of type pointer to object,
5827 qualification conversions (_conv.qual_) and the array-to-pointer
5828 conversion (_conv.array_) are applied. */
5829 else if (TYPE_PTROBV_P (type))
5831 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5833 A template-argument for a non-type, non-template template-parameter
5834 shall be one of: [...]
5836 -- the name of a non-type template-parameter;
5837 -- the address of an object or function with external linkage, [...]
5838 expressed as "& id-expression" where the & is optional if the name
5839 refers to a function or array, or if the corresponding
5840 template-parameter is a reference.
5842 Here, we do not care about functions, as they are invalid anyway
5843 for a parameter of type pointer-to-object. */
5845 if (DECL_P (expr) && DECL_TEMPLATE_PARM_P (expr))
5846 /* Non-type template parameters are OK. */
5848 else if (cxx_dialect >= cxx0x && integer_zerop (expr))
5849 /* Null pointer values are OK in C++11. */;
5850 else if (TREE_CODE (expr) != ADDR_EXPR
5851 && TREE_CODE (expr_type) != ARRAY_TYPE)
5853 if (TREE_CODE (expr) == VAR_DECL)
5855 error ("%qD is not a valid template argument "
5856 "because %qD is a variable, not the address of "
5861 /* Other values, like integer constants, might be valid
5862 non-type arguments of some other type. */
5863 return error_mark_node;
5869 decl = ((TREE_CODE (expr) == ADDR_EXPR)
5870 ? TREE_OPERAND (expr, 0) : expr);
5871 if (TREE_CODE (decl) != VAR_DECL)
5873 error ("%qE is not a valid template argument of type %qT "
5874 "because %qE is not a variable",
5878 else if (cxx_dialect < cxx0x && !DECL_EXTERNAL_LINKAGE_P (decl))
5880 error ("%qE is not a valid template argument of type %qT "
5881 "because %qD does not have external linkage",
5885 else if (cxx_dialect >= cxx0x && decl_linkage (decl) == lk_none)
5887 error ("%qE is not a valid template argument of type %qT "
5888 "because %qD has no linkage",
5894 expr = decay_conversion (expr);
5895 if (expr == error_mark_node)
5896 return error_mark_node;
5898 expr = perform_qualification_conversions (type, expr);
5899 if (expr == error_mark_node)
5900 return error_mark_node;
5902 /* [temp.arg.nontype]/5, bullet 3
5904 For a non-type template-parameter of type reference to object, no
5905 conversions apply. The type referred to by the reference may be more
5906 cv-qualified than the (otherwise identical) type of the
5907 template-argument. The template-parameter is bound directly to the
5908 template-argument, which must be an lvalue. */
5909 else if (TYPE_REF_OBJ_P (type))
5911 if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type),
5913 return error_mark_node;
5915 if (!at_least_as_qualified_p (TREE_TYPE (type), expr_type))
5917 error ("%qE is not a valid template argument for type %qT "
5918 "because of conflicts in cv-qualification", expr, type);
5922 if (!real_lvalue_p (expr))
5924 error ("%qE is not a valid template argument for type %qT "
5925 "because it is not an lvalue", expr, type);
5929 /* [temp.arg.nontype]/1
5931 A template-argument for a non-type, non-template template-parameter
5932 shall be one of: [...]
5934 -- the address of an object or function with external linkage. */
5935 if (TREE_CODE (expr) == INDIRECT_REF
5936 && TYPE_REF_OBJ_P (TREE_TYPE (TREE_OPERAND (expr, 0))))
5938 expr = TREE_OPERAND (expr, 0);
5941 error ("%q#D is not a valid template argument for type %qT "
5942 "because a reference variable does not have a constant "
5943 "address", expr, type);
5950 error ("%qE is not a valid template argument for type %qT "
5951 "because it is not an object with external linkage",
5956 if (!DECL_EXTERNAL_LINKAGE_P (expr))
5958 error ("%qE is not a valid template argument for type %qT "
5959 "because object %qD has not external linkage",
5964 expr = build_nop (type, build_address (expr));
5966 /* [temp.arg.nontype]/5, bullet 4
5968 For a non-type template-parameter of type pointer to function, only
5969 the function-to-pointer conversion (_conv.func_) is applied. If the
5970 template-argument represents a set of overloaded functions (or a
5971 pointer to such), the matching function is selected from the set
5973 else if (TYPE_PTRFN_P (type))
5975 /* If the argument is a template-id, we might not have enough
5976 context information to decay the pointer. */
5977 if (!type_unknown_p (expr_type))
5979 expr = decay_conversion (expr);
5980 if (expr == error_mark_node)
5981 return error_mark_node;
5984 if (cxx_dialect >= cxx0x && integer_zerop (expr))
5985 /* Null pointer values are OK in C++11. */
5986 return perform_qualification_conversions (type, expr);
5988 expr = convert_nontype_argument_function (type, expr);
5989 if (!expr || expr == error_mark_node)
5992 if (TREE_CODE (expr) != ADDR_EXPR)
5994 error ("%qE is not a valid template argument for type %qT", expr, type);
5995 error ("it must be the address of a function with external linkage");
5999 /* [temp.arg.nontype]/5, bullet 5
6001 For a non-type template-parameter of type reference to function, no
6002 conversions apply. If the template-argument represents a set of
6003 overloaded functions, the matching function is selected from the set
6005 else if (TYPE_REFFN_P (type))
6007 if (TREE_CODE (expr) == ADDR_EXPR)
6009 error ("%qE is not a valid template argument for type %qT "
6010 "because it is a pointer", expr, type);
6011 inform (input_location, "try using %qE instead", TREE_OPERAND (expr, 0));
6015 expr = convert_nontype_argument_function (TREE_TYPE (type), expr);
6016 if (!expr || expr == error_mark_node)
6019 expr = build_nop (type, build_address (expr));
6021 /* [temp.arg.nontype]/5, bullet 6
6023 For a non-type template-parameter of type pointer to member function,
6024 no conversions apply. If the template-argument represents a set of
6025 overloaded member functions, the matching member function is selected
6026 from the set (_over.over_). */
6027 else if (TYPE_PTRMEMFUNC_P (type))
6029 expr = instantiate_type (type, expr, tf_none);
6030 if (expr == error_mark_node)
6031 return error_mark_node;
6033 /* [temp.arg.nontype] bullet 1 says the pointer to member
6034 expression must be a pointer-to-member constant. */
6035 if (!check_valid_ptrmem_cst_expr (type, expr, complain))
6036 return error_mark_node;
6038 /* There is no way to disable standard conversions in
6039 resolve_address_of_overloaded_function (called by
6040 instantiate_type). It is possible that the call succeeded by
6041 converting &B::I to &D::I (where B is a base of D), so we need
6042 to reject this conversion here.
6044 Actually, even if there was a way to disable standard conversions,
6045 it would still be better to reject them here so that we can
6046 provide a superior diagnostic. */
6047 if (!same_type_p (TREE_TYPE (expr), type))
6049 error ("%qE is not a valid template argument for type %qT "
6050 "because it is of type %qT", expr, type,
6052 /* If we are just one standard conversion off, explain. */
6053 if (can_convert (type, TREE_TYPE (expr)))
6054 inform (input_location,
6055 "standard conversions are not allowed in this context");
6059 /* [temp.arg.nontype]/5, bullet 7
6061 For a non-type template-parameter of type pointer to data member,
6062 qualification conversions (_conv.qual_) are applied. */
6063 else if (TYPE_PTRMEM_P (type))
6065 /* [temp.arg.nontype] bullet 1 says the pointer to member
6066 expression must be a pointer-to-member constant. */
6067 if (!check_valid_ptrmem_cst_expr (type, expr, complain))
6068 return error_mark_node;
6070 expr = perform_qualification_conversions (type, expr);
6071 if (expr == error_mark_node)
6074 else if (NULLPTR_TYPE_P (type))
6076 if (expr != nullptr_node)
6078 error ("%qE is not a valid template argument for type %qT "
6079 "because it is of type %qT", expr, type, TREE_TYPE (expr));
6084 /* A template non-type parameter must be one of the above. */
6088 /* Sanity check: did we actually convert the argument to the
6090 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6091 (type, TREE_TYPE (expr)));
6095 /* Subroutine of coerce_template_template_parms, which returns 1 if
6096 PARM_PARM and ARG_PARM match using the rule for the template
6097 parameters of template template parameters. Both PARM and ARG are
6098 template parameters; the rest of the arguments are the same as for
6099 coerce_template_template_parms.
6102 coerce_template_template_parm (tree parm,
6104 tsubst_flags_t complain,
6108 if (arg == NULL_TREE || arg == error_mark_node
6109 || parm == NULL_TREE || parm == error_mark_node)
6112 if (TREE_CODE (arg) != TREE_CODE (parm))
6115 switch (TREE_CODE (parm))
6118 /* We encounter instantiations of templates like
6119 template <template <template <class> class> class TT>
6122 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
6123 tree argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
6125 if (!coerce_template_template_parms
6126 (parmparm, argparm, complain, in_decl, outer_args))
6132 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (arg))
6133 && !TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
6134 /* Argument is a parameter pack but parameter is not. */
6139 /* The tsubst call is used to handle cases such as
6141 template <int> class C {};
6142 template <class T, template <T> class TT> class D {};
6145 i.e. the parameter list of TT depends on earlier parameters. */
6146 if (!uses_template_parms (TREE_TYPE (arg))
6148 (tsubst (TREE_TYPE (parm), outer_args, complain, in_decl),
6152 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (arg))
6153 && !TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
6154 /* Argument is a parameter pack but parameter is not. */
6167 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
6168 template template parameters. Both PARM_PARMS and ARG_PARMS are
6169 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
6172 Consider the example:
6173 template <class T> class A;
6174 template<template <class U> class TT> class B;
6176 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
6177 the parameters to A, and OUTER_ARGS contains A. */
6180 coerce_template_template_parms (tree parm_parms,
6182 tsubst_flags_t complain,
6186 int nparms, nargs, i;
6190 gcc_assert (TREE_CODE (parm_parms) == TREE_VEC);
6191 gcc_assert (TREE_CODE (arg_parms) == TREE_VEC);
6193 nparms = TREE_VEC_LENGTH (parm_parms);
6194 nargs = TREE_VEC_LENGTH (arg_parms);
6196 /* Determine whether we have a parameter pack at the end of the
6197 template template parameter's template parameter list. */
6198 if (TREE_VEC_ELT (parm_parms, nparms - 1) != error_mark_node)
6200 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, nparms - 1));
6202 if (parm == error_mark_node)
6205 switch (TREE_CODE (parm))
6209 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
6214 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
6224 && !(variadic_p && nargs >= nparms - 1))
6227 /* Check all of the template parameters except the parameter pack at
6228 the end (if any). */
6229 for (i = 0; i < nparms - variadic_p; ++i)
6231 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node
6232 || TREE_VEC_ELT (arg_parms, i) == error_mark_node)
6235 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
6236 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
6238 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
6246 /* Check each of the template parameters in the template
6247 argument against the template parameter pack at the end of
6248 the template template parameter. */
6249 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node)
6252 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
6254 for (; i < nargs; ++i)
6256 if (TREE_VEC_ELT (arg_parms, i) == error_mark_node)
6259 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
6261 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
6270 /* Verifies that the deduced template arguments (in TARGS) for the
6271 template template parameters (in TPARMS) represent valid bindings,
6272 by comparing the template parameter list of each template argument
6273 to the template parameter list of its corresponding template
6274 template parameter, in accordance with DR150. This
6275 routine can only be called after all template arguments have been
6276 deduced. It will return TRUE if all of the template template
6277 parameter bindings are okay, FALSE otherwise. */
6279 template_template_parm_bindings_ok_p (tree tparms, tree targs)
6281 int i, ntparms = TREE_VEC_LENGTH (tparms);
6284 /* We're dealing with template parms in this process. */
6285 ++processing_template_decl;
6287 targs = INNERMOST_TEMPLATE_ARGS (targs);
6289 for (i = 0; i < ntparms; ++i)
6291 tree tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
6292 tree targ = TREE_VEC_ELT (targs, i);
6294 if (TREE_CODE (tparm) == TEMPLATE_DECL && targ)
6296 tree packed_args = NULL_TREE;
6299 if (ARGUMENT_PACK_P (targ))
6301 /* Look inside the argument pack. */
6302 packed_args = ARGUMENT_PACK_ARGS (targ);
6303 len = TREE_VEC_LENGTH (packed_args);
6306 for (idx = 0; idx < len; ++idx)
6308 tree targ_parms = NULL_TREE;
6311 /* Extract the next argument from the argument
6313 targ = TREE_VEC_ELT (packed_args, idx);
6315 if (PACK_EXPANSION_P (targ))
6316 /* Look at the pattern of the pack expansion. */
6317 targ = PACK_EXPANSION_PATTERN (targ);
6319 /* Extract the template parameters from the template
6321 if (TREE_CODE (targ) == TEMPLATE_DECL)
6322 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (targ);
6323 else if (TREE_CODE (targ) == TEMPLATE_TEMPLATE_PARM)
6324 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (TYPE_NAME (targ));
6326 /* Verify that we can coerce the template template
6327 parameters from the template argument to the template
6328 parameter. This requires an exact match. */
6330 && !coerce_template_template_parms
6331 (DECL_INNERMOST_TEMPLATE_PARMS (tparm),
6346 --processing_template_decl;
6350 /* Since type attributes aren't mangled, we need to strip them from
6351 template type arguments. */
6354 canonicalize_type_argument (tree arg, tsubst_flags_t complain)
6357 if (!arg || arg == error_mark_node || arg == TYPE_CANONICAL (arg))
6359 mv = TYPE_MAIN_VARIANT (arg);
6360 arg = strip_typedefs (arg);
6361 if (TYPE_ALIGN (arg) != TYPE_ALIGN (mv)
6362 || TYPE_ATTRIBUTES (arg) != TYPE_ATTRIBUTES (mv))
6364 if (complain & tf_warning)
6365 warning (0, "ignoring attributes on template argument %qT", arg);
6366 arg = build_aligned_type (arg, TYPE_ALIGN (mv));
6367 arg = cp_build_type_attribute_variant (arg, TYPE_ATTRIBUTES (mv));
6372 /* Convert the indicated template ARG as necessary to match the
6373 indicated template PARM. Returns the converted ARG, or
6374 error_mark_node if the conversion was unsuccessful. Error and
6375 warning messages are issued under control of COMPLAIN. This
6376 conversion is for the Ith parameter in the parameter list. ARGS is
6377 the full set of template arguments deduced so far. */
6380 convert_template_argument (tree parm,
6383 tsubst_flags_t complain,
6389 int is_type, requires_type, is_tmpl_type, requires_tmpl_type;
6391 if (TREE_CODE (arg) == TREE_LIST
6392 && TREE_CODE (TREE_VALUE (arg)) == OFFSET_REF)
6394 /* The template argument was the name of some
6395 member function. That's usually
6396 invalid, but static members are OK. In any
6397 case, grab the underlying fields/functions
6398 and issue an error later if required. */
6399 orig_arg = TREE_VALUE (arg);
6400 TREE_TYPE (arg) = unknown_type_node;
6405 requires_tmpl_type = TREE_CODE (parm) == TEMPLATE_DECL;
6406 requires_type = (TREE_CODE (parm) == TYPE_DECL
6407 || requires_tmpl_type);
6409 /* When determining whether an argument pack expansion is a template,
6410 look at the pattern. */
6411 if (TREE_CODE (arg) == TYPE_PACK_EXPANSION)
6412 arg = PACK_EXPANSION_PATTERN (arg);
6414 /* Deal with an injected-class-name used as a template template arg. */
6415 if (requires_tmpl_type && CLASS_TYPE_P (arg))
6417 tree t = maybe_get_template_decl_from_type_decl (TYPE_NAME (arg));
6418 if (TREE_CODE (t) == TEMPLATE_DECL)
6420 if (cxx_dialect >= cxx0x)
6421 /* OK under DR 1004. */;
6422 else if (complain & tf_warning_or_error)
6423 pedwarn (input_location, OPT_pedantic, "injected-class-name %qD"
6424 " used as template template argument", TYPE_NAME (arg));
6425 else if (flag_pedantic_errors)
6433 ((TREE_CODE (arg) == TEMPLATE_DECL
6434 && TREE_CODE (DECL_TEMPLATE_RESULT (arg)) == TYPE_DECL)
6435 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
6436 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE);
6439 && (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
6440 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE))
6441 arg = TYPE_STUB_DECL (arg);
6443 is_type = TYPE_P (arg) || is_tmpl_type;
6445 if (requires_type && ! is_type && TREE_CODE (arg) == SCOPE_REF
6446 && TREE_CODE (TREE_OPERAND (arg, 0)) == TEMPLATE_TYPE_PARM)
6448 if (TREE_CODE (TREE_OPERAND (arg, 1)) == BIT_NOT_EXPR)
6450 if (complain & tf_error)
6451 error ("invalid use of destructor %qE as a type", orig_arg);
6452 return error_mark_node;
6455 permerror (input_location,
6456 "to refer to a type member of a template parameter, "
6457 "use %<typename %E%>", orig_arg);
6459 orig_arg = make_typename_type (TREE_OPERAND (arg, 0),
6460 TREE_OPERAND (arg, 1),
6462 complain & tf_error);
6466 if (is_type != requires_type)
6470 if (complain & tf_error)
6472 error ("type/value mismatch at argument %d in template "
6473 "parameter list for %qD",
6476 error (" expected a constant of type %qT, got %qT",
6478 (DECL_P (arg) ? DECL_NAME (arg) : orig_arg));
6479 else if (requires_tmpl_type)
6480 error (" expected a class template, got %qE", orig_arg);
6482 error (" expected a type, got %qE", orig_arg);
6485 return error_mark_node;
6487 if (is_tmpl_type ^ requires_tmpl_type)
6489 if (in_decl && (complain & tf_error))
6491 error ("type/value mismatch at argument %d in template "
6492 "parameter list for %qD",
6495 error (" expected a type, got %qT", DECL_NAME (arg));
6497 error (" expected a class template, got %qT", orig_arg);
6499 return error_mark_node;
6504 if (requires_tmpl_type)
6506 if (TREE_CODE (TREE_TYPE (arg)) == UNBOUND_CLASS_TEMPLATE)
6507 /* The number of argument required is not known yet.
6508 Just accept it for now. */
6509 val = TREE_TYPE (arg);
6512 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
6515 argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
6517 if (coerce_template_template_parms (parmparm, argparm,
6523 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6525 if (val != error_mark_node)
6527 if (DECL_TEMPLATE_TEMPLATE_PARM_P (val))
6528 val = TREE_TYPE (val);
6529 if (TREE_CODE (orig_arg) == TYPE_PACK_EXPANSION)
6530 val = make_pack_expansion (val);
6535 if (in_decl && (complain & tf_error))
6537 error ("type/value mismatch at argument %d in "
6538 "template parameter list for %qD",
6540 error (" expected a template of type %qD, got %qT",
6544 val = error_mark_node;
6550 /* We only form one instance of each template specialization.
6551 Therefore, if we use a non-canonical variant (i.e., a
6552 typedef), any future messages referring to the type will use
6553 the typedef, which is confusing if those future uses do not
6554 themselves also use the typedef. */
6556 val = canonicalize_type_argument (val, complain);
6560 tree t = tsubst (TREE_TYPE (parm), args, complain, in_decl);
6562 if (invalid_nontype_parm_type_p (t, complain))
6563 return error_mark_node;
6565 if (template_parameter_pack_p (parm) && ARGUMENT_PACK_P (orig_arg))
6567 if (same_type_p (t, TREE_TYPE (orig_arg)))
6571 /* Not sure if this is reachable, but it doesn't hurt
6573 error ("type mismatch in nontype parameter pack");
6574 val = error_mark_node;
6577 else if (!uses_template_parms (orig_arg) && !uses_template_parms (t))
6578 /* We used to call digest_init here. However, digest_init
6579 will report errors, which we don't want when complain
6580 is zero. More importantly, digest_init will try too
6581 hard to convert things: for example, `0' should not be
6582 converted to pointer type at this point according to
6583 the standard. Accepting this is not merely an
6584 extension, since deciding whether or not these
6585 conversions can occur is part of determining which
6586 function template to call, or whether a given explicit
6587 argument specification is valid. */
6588 val = convert_nontype_argument (t, orig_arg, complain);
6592 if (val == NULL_TREE)
6593 val = error_mark_node;
6594 else if (val == error_mark_node && (complain & tf_error))
6595 error ("could not convert template argument %qE to %qT", orig_arg, t);
6597 if (TREE_CODE (val) == SCOPE_REF)
6599 /* Strip typedefs from the SCOPE_REF. */
6600 tree type = canonicalize_type_argument (TREE_TYPE (val), complain);
6601 tree scope = canonicalize_type_argument (TREE_OPERAND (val, 0),
6603 val = build_qualified_name (type, scope, TREE_OPERAND (val, 1),
6604 QUALIFIED_NAME_IS_TEMPLATE (val));
6611 /* Coerces the remaining template arguments in INNER_ARGS (from
6612 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6613 Returns the coerced argument pack. PARM_IDX is the position of this
6614 parameter in the template parameter list. ARGS is the original
6615 template argument list. */
6617 coerce_template_parameter_pack (tree parms,
6625 tsubst_flags_t complain)
6627 tree parm = TREE_VEC_ELT (parms, parm_idx);
6628 int nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
6631 tree packed_types = NULL_TREE;
6633 if (arg_idx > nargs)
6636 packed_args = make_tree_vec (nargs - arg_idx);
6638 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL
6639 && uses_parameter_packs (TREE_TYPE (TREE_VALUE (parm))))
6641 /* When the template parameter is a non-type template
6642 parameter pack whose type uses parameter packs, we need
6643 to look at each of the template arguments
6644 separately. Build a vector of the types for these
6645 non-type template parameters in PACKED_TYPES. */
6647 = make_pack_expansion (TREE_TYPE (TREE_VALUE (parm)));
6648 packed_types = tsubst_pack_expansion (expansion, args,
6651 if (packed_types == error_mark_node)
6652 return error_mark_node;
6654 /* Check that we have the right number of arguments. */
6656 && !PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx))
6657 && nargs - arg_idx != TREE_VEC_LENGTH (packed_types))
6660 = TREE_VEC_LENGTH (parms) - 1 + TREE_VEC_LENGTH (packed_types);
6661 error ("wrong number of template arguments (%d, should be %d)",
6662 nargs, needed_parms);
6663 return error_mark_node;
6666 /* If we aren't able to check the actual arguments now
6667 (because they haven't been expanded yet), we can at least
6668 verify that all of the types used for the non-type
6669 template parameter pack are, in fact, valid for non-type
6670 template parameters. */
6672 && PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx)))
6674 int j, len = TREE_VEC_LENGTH (packed_types);
6675 for (j = 0; j < len; ++j)
6677 tree t = TREE_VEC_ELT (packed_types, j);
6678 if (invalid_nontype_parm_type_p (t, complain))
6679 return error_mark_node;
6684 /* Convert the remaining arguments, which will be a part of the
6685 parameter pack "parm". */
6686 for (; arg_idx < nargs; ++arg_idx)
6688 tree arg = TREE_VEC_ELT (inner_args, arg_idx);
6689 tree actual_parm = TREE_VALUE (parm);
6691 if (packed_types && !PACK_EXPANSION_P (arg))
6693 /* When we have a vector of types (corresponding to the
6694 non-type template parameter pack that uses parameter
6695 packs in its type, as mention above), and the
6696 argument is not an expansion (which expands to a
6697 currently unknown number of arguments), clone the
6698 parm and give it the next type in PACKED_TYPES. */
6699 actual_parm = copy_node (actual_parm);
6700 TREE_TYPE (actual_parm) =
6701 TREE_VEC_ELT (packed_types, arg_idx - parm_idx);
6704 if (arg != error_mark_node)
6705 arg = convert_template_argument (actual_parm,
6706 arg, new_args, complain, parm_idx,
6708 if (arg == error_mark_node)
6710 TREE_VEC_ELT (packed_args, arg_idx - parm_idx) = arg;
6713 if (TREE_CODE (TREE_VALUE (parm)) == TYPE_DECL
6714 || TREE_CODE (TREE_VALUE (parm)) == TEMPLATE_DECL)
6715 argument_pack = cxx_make_type (TYPE_ARGUMENT_PACK);
6718 argument_pack = make_node (NONTYPE_ARGUMENT_PACK);
6719 TREE_TYPE (argument_pack)
6720 = tsubst (TREE_TYPE (TREE_VALUE (parm)), new_args, complain, in_decl);
6721 TREE_CONSTANT (argument_pack) = 1;
6724 SET_ARGUMENT_PACK_ARGS (argument_pack, packed_args);
6725 #ifdef ENABLE_CHECKING
6726 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (packed_args,
6727 TREE_VEC_LENGTH (packed_args));
6729 return argument_pack;
6732 /* Convert all template arguments to their appropriate types, and
6733 return a vector containing the innermost resulting template
6734 arguments. If any error occurs, return error_mark_node. Error and
6735 warning messages are issued under control of COMPLAIN.
6737 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6738 for arguments not specified in ARGS. Otherwise, if
6739 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6740 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6741 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6745 coerce_template_parms (tree parms,
6748 tsubst_flags_t complain,
6749 bool require_all_args,
6750 bool use_default_args)
6752 int nparms, nargs, parm_idx, arg_idx, lost = 0;
6755 tree new_inner_args;
6756 int saved_unevaluated_operand;
6757 int saved_inhibit_evaluation_warnings;
6759 /* When used as a boolean value, indicates whether this is a
6760 variadic template parameter list. Since it's an int, we can also
6761 subtract it from nparms to get the number of non-variadic
6764 int post_variadic_parms = 0;
6766 if (args == error_mark_node)
6767 return error_mark_node;
6769 nparms = TREE_VEC_LENGTH (parms);
6771 /* Determine if there are any parameter packs. */
6772 for (parm_idx = 0; parm_idx < nparms; ++parm_idx)
6774 tree tparm = TREE_VALUE (TREE_VEC_ELT (parms, parm_idx));
6776 ++post_variadic_parms;
6777 if (template_parameter_pack_p (tparm))
6781 inner_args = INNERMOST_TEMPLATE_ARGS (args);
6782 /* If there are no parameters that follow a parameter pack, we need to
6783 expand any argument packs so that we can deduce a parameter pack from
6784 some non-packed args followed by an argument pack, as in variadic85.C.
6785 If there are such parameters, we need to leave argument packs intact
6786 so the arguments are assigned properly. This can happen when dealing
6787 with a nested class inside a partial specialization of a class
6788 template, as in variadic92.C, or when deducing a template parameter pack
6789 from a sub-declarator, as in variadic114.C. */
6790 if (!post_variadic_parms)
6791 inner_args = expand_template_argument_pack (inner_args);
6793 nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
6794 if ((nargs > nparms && !variadic_p)
6795 || (nargs < nparms - variadic_p
6797 && (!use_default_args
6798 || (TREE_VEC_ELT (parms, nargs) != error_mark_node
6799 && !TREE_PURPOSE (TREE_VEC_ELT (parms, nargs))))))
6801 if (complain & tf_error)
6805 nparms -= variadic_p;
6806 error ("wrong number of template arguments "
6807 "(%d, should be %d or more)", nargs, nparms);
6810 error ("wrong number of template arguments "
6811 "(%d, should be %d)", nargs, nparms);
6814 error ("provided for %q+D", in_decl);
6817 return error_mark_node;
6820 /* We need to evaluate the template arguments, even though this
6821 template-id may be nested within a "sizeof". */
6822 saved_unevaluated_operand = cp_unevaluated_operand;
6823 cp_unevaluated_operand = 0;
6824 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
6825 c_inhibit_evaluation_warnings = 0;
6826 new_inner_args = make_tree_vec (nparms);
6827 new_args = add_outermost_template_args (args, new_inner_args);
6828 for (parm_idx = 0, arg_idx = 0; parm_idx < nparms; parm_idx++, arg_idx++)
6833 /* Get the Ith template parameter. */
6834 parm = TREE_VEC_ELT (parms, parm_idx);
6836 if (parm == error_mark_node)
6838 TREE_VEC_ELT (new_inner_args, arg_idx) = error_mark_node;
6842 /* Calculate the next argument. */
6843 if (arg_idx < nargs)
6844 arg = TREE_VEC_ELT (inner_args, arg_idx);
6848 if (template_parameter_pack_p (TREE_VALUE (parm))
6849 && !(arg && ARGUMENT_PACK_P (arg)))
6851 /* All remaining arguments will be placed in the
6852 template parameter pack PARM. */
6853 arg = coerce_template_parameter_pack (parms, parm_idx, args,
6854 inner_args, arg_idx,
6858 /* Store this argument. */
6859 if (arg == error_mark_node)
6861 TREE_VEC_ELT (new_inner_args, parm_idx) = arg;
6863 /* We are done with all of the arguments. */
6870 if (PACK_EXPANSION_P (arg))
6872 /* We don't know how many args we have yet, just
6873 use the unconverted ones for now. */
6874 new_inner_args = args;
6878 else if (require_all_args)
6880 /* There must be a default arg in this case. */
6881 arg = tsubst_template_arg (TREE_PURPOSE (parm), new_args,
6883 /* The position of the first default template argument,
6884 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6886 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args))
6887 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args, arg_idx);
6892 if (arg == error_mark_node)
6894 if (complain & tf_error)
6895 error ("template argument %d is invalid", arg_idx + 1);
6898 /* This only occurs if there was an error in the template
6899 parameter list itself (which we would already have
6900 reported) that we are trying to recover from, e.g., a class
6901 template with a parameter list such as
6902 template<typename..., typename>. */
6905 arg = convert_template_argument (TREE_VALUE (parm),
6906 arg, new_args, complain,
6909 if (arg == error_mark_node)
6911 TREE_VEC_ELT (new_inner_args, arg_idx) = arg;
6913 cp_unevaluated_operand = saved_unevaluated_operand;
6914 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
6917 return error_mark_node;
6919 #ifdef ENABLE_CHECKING
6920 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args))
6921 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args,
6922 TREE_VEC_LENGTH (new_inner_args));
6925 return new_inner_args;
6928 /* Returns 1 if template args OT and NT are equivalent. */
6931 template_args_equal (tree ot, tree nt)
6935 if (nt == NULL_TREE || ot == NULL_TREE)
6938 if (TREE_CODE (nt) == TREE_VEC)
6939 /* For member templates */
6940 return TREE_CODE (ot) == TREE_VEC && comp_template_args (ot, nt);
6941 else if (PACK_EXPANSION_P (ot))
6942 return (PACK_EXPANSION_P (nt)
6943 && template_args_equal (PACK_EXPANSION_PATTERN (ot),
6944 PACK_EXPANSION_PATTERN (nt))
6945 && template_args_equal (PACK_EXPANSION_EXTRA_ARGS (ot),
6946 PACK_EXPANSION_EXTRA_ARGS (nt)));
6947 else if (ARGUMENT_PACK_P (ot))
6952 if (!ARGUMENT_PACK_P (nt))
6955 opack = ARGUMENT_PACK_ARGS (ot);
6956 npack = ARGUMENT_PACK_ARGS (nt);
6957 len = TREE_VEC_LENGTH (opack);
6958 if (TREE_VEC_LENGTH (npack) != len)
6960 for (i = 0; i < len; ++i)
6961 if (!template_args_equal (TREE_VEC_ELT (opack, i),
6962 TREE_VEC_ELT (npack, i)))
6966 else if (ot && TREE_CODE (ot) == ARGUMENT_PACK_SELECT)
6968 /* We get here probably because we are in the middle of substituting
6969 into the pattern of a pack expansion. In that case the
6970 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
6971 interested in. So we want to use the initial pack argument for
6973 ot = ARGUMENT_PACK_SELECT_FROM_PACK (ot);
6974 if (nt && TREE_CODE (nt) == ARGUMENT_PACK_SELECT)
6975 nt = ARGUMENT_PACK_SELECT_FROM_PACK (nt);
6976 return template_args_equal (ot, nt);
6978 else if (TYPE_P (nt))
6979 return TYPE_P (ot) && same_type_p (ot, nt);
6980 else if (TREE_CODE (ot) == TREE_VEC || TYPE_P (ot))
6983 return cp_tree_equal (ot, nt);
6986 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
6987 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
6988 NEWARG_PTR with the offending arguments if they are non-NULL. */
6991 comp_template_args_with_info (tree oldargs, tree newargs,
6992 tree *oldarg_ptr, tree *newarg_ptr)
6996 if (oldargs == newargs)
6999 if (!oldargs || !newargs)
7002 if (TREE_VEC_LENGTH (oldargs) != TREE_VEC_LENGTH (newargs))
7005 for (i = 0; i < TREE_VEC_LENGTH (oldargs); ++i)
7007 tree nt = TREE_VEC_ELT (newargs, i);
7008 tree ot = TREE_VEC_ELT (oldargs, i);
7010 if (! template_args_equal (ot, nt))
7012 if (oldarg_ptr != NULL)
7014 if (newarg_ptr != NULL)
7022 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
7023 of template arguments. Returns 0 otherwise. */
7026 comp_template_args (tree oldargs, tree newargs)
7028 return comp_template_args_with_info (oldargs, newargs, NULL, NULL);
7032 add_pending_template (tree d)
7034 tree ti = (TYPE_P (d)
7035 ? CLASSTYPE_TEMPLATE_INFO (d)
7036 : DECL_TEMPLATE_INFO (d));
7037 struct pending_template *pt;
7040 if (TI_PENDING_TEMPLATE_FLAG (ti))
7043 /* We are called both from instantiate_decl, where we've already had a
7044 tinst_level pushed, and instantiate_template, where we haven't.
7046 level = !current_tinst_level || current_tinst_level->decl != d;
7049 push_tinst_level (d);
7051 pt = ggc_alloc_pending_template ();
7053 pt->tinst = current_tinst_level;
7054 if (last_pending_template)
7055 last_pending_template->next = pt;
7057 pending_templates = pt;
7059 last_pending_template = pt;
7061 TI_PENDING_TEMPLATE_FLAG (ti) = 1;
7068 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
7069 ARGLIST. Valid choices for FNS are given in the cp-tree.def
7070 documentation for TEMPLATE_ID_EXPR. */
7073 lookup_template_function (tree fns, tree arglist)
7077 if (fns == error_mark_node || arglist == error_mark_node)
7078 return error_mark_node;
7080 gcc_assert (!arglist || TREE_CODE (arglist) == TREE_VEC);
7082 if (!is_overloaded_fn (fns) && TREE_CODE (fns) != IDENTIFIER_NODE)
7084 error ("%q#D is not a function template", fns);
7085 return error_mark_node;
7088 if (BASELINK_P (fns))
7090 BASELINK_FUNCTIONS (fns) = build2 (TEMPLATE_ID_EXPR,
7092 BASELINK_FUNCTIONS (fns),
7097 type = TREE_TYPE (fns);
7098 if (TREE_CODE (fns) == OVERLOAD || !type)
7099 type = unknown_type_node;
7101 return build2 (TEMPLATE_ID_EXPR, type, fns, arglist);
7104 /* Within the scope of a template class S<T>, the name S gets bound
7105 (in build_self_reference) to a TYPE_DECL for the class, not a
7106 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
7107 or one of its enclosing classes, and that type is a template,
7108 return the associated TEMPLATE_DECL. Otherwise, the original
7111 Also handle the case when DECL is a TREE_LIST of ambiguous
7112 injected-class-names from different bases. */
7115 maybe_get_template_decl_from_type_decl (tree decl)
7117 if (decl == NULL_TREE)
7120 /* DR 176: A lookup that finds an injected-class-name (10.2
7121 [class.member.lookup]) can result in an ambiguity in certain cases
7122 (for example, if it is found in more than one base class). If all of
7123 the injected-class-names that are found refer to specializations of
7124 the same class template, and if the name is followed by a
7125 template-argument-list, the reference refers to the class template
7126 itself and not a specialization thereof, and is not ambiguous. */
7127 if (TREE_CODE (decl) == TREE_LIST)
7129 tree t, tmpl = NULL_TREE;
7130 for (t = decl; t; t = TREE_CHAIN (t))
7132 tree elt = maybe_get_template_decl_from_type_decl (TREE_VALUE (t));
7135 else if (tmpl != elt)
7138 if (tmpl && t == NULL_TREE)
7144 return (decl != NULL_TREE
7145 && DECL_SELF_REFERENCE_P (decl)
7146 && CLASSTYPE_TEMPLATE_INFO (TREE_TYPE (decl)))
7147 ? CLASSTYPE_TI_TEMPLATE (TREE_TYPE (decl)) : decl;
7150 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
7151 parameters, find the desired type.
7153 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
7155 IN_DECL, if non-NULL, is the template declaration we are trying to
7158 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
7159 the class we are looking up.
7161 Issue error and warning messages under control of COMPLAIN.
7163 If the template class is really a local class in a template
7164 function, then the FUNCTION_CONTEXT is the function in which it is
7167 ??? Note that this function is currently called *twice* for each
7168 template-id: the first time from the parser, while creating the
7169 incomplete type (finish_template_type), and the second type during the
7170 real instantiation (instantiate_template_class). This is surely something
7171 that we want to avoid. It also causes some problems with argument
7172 coercion (see convert_nontype_argument for more information on this). */
7175 lookup_template_class_1 (tree d1, tree arglist, tree in_decl, tree context,
7176 int entering_scope, tsubst_flags_t complain)
7178 tree templ = NULL_TREE, parmlist;
7185 if (TREE_CODE (d1) == IDENTIFIER_NODE)
7187 tree value = innermost_non_namespace_value (d1);
7188 if (value && DECL_TEMPLATE_TEMPLATE_PARM_P (value))
7193 push_decl_namespace (context);
7194 templ = lookup_name (d1);
7195 templ = maybe_get_template_decl_from_type_decl (templ);
7197 pop_decl_namespace ();
7200 context = DECL_CONTEXT (templ);
7202 else if (TREE_CODE (d1) == TYPE_DECL && MAYBE_CLASS_TYPE_P (TREE_TYPE (d1)))
7204 tree type = TREE_TYPE (d1);
7206 /* If we are declaring a constructor, say A<T>::A<T>, we will get
7207 an implicit typename for the second A. Deal with it. */
7208 if (TREE_CODE (type) == TYPENAME_TYPE && TREE_TYPE (type))
7209 type = TREE_TYPE (type);
7211 if (CLASSTYPE_TEMPLATE_INFO (type))
7213 templ = CLASSTYPE_TI_TEMPLATE (type);
7214 d1 = DECL_NAME (templ);
7217 else if (TREE_CODE (d1) == ENUMERAL_TYPE
7218 || (TYPE_P (d1) && MAYBE_CLASS_TYPE_P (d1)))
7220 templ = TYPE_TI_TEMPLATE (d1);
7221 d1 = DECL_NAME (templ);
7223 else if (TREE_CODE (d1) == TEMPLATE_DECL
7224 && DECL_TEMPLATE_RESULT (d1)
7225 && TREE_CODE (DECL_TEMPLATE_RESULT (d1)) == TYPE_DECL)
7228 d1 = DECL_NAME (templ);
7229 context = DECL_CONTEXT (templ);
7232 /* Issue an error message if we didn't find a template. */
7235 if (complain & tf_error)
7236 error ("%qT is not a template", d1);
7237 return error_mark_node;
7240 if (TREE_CODE (templ) != TEMPLATE_DECL
7241 /* Make sure it's a user visible template, if it was named by
7243 || ((complain & tf_user) && !DECL_TEMPLATE_PARM_P (templ)
7244 && !PRIMARY_TEMPLATE_P (templ)))
7246 if (complain & tf_error)
7248 error ("non-template type %qT used as a template", d1);
7250 error ("for template declaration %q+D", in_decl);
7252 return error_mark_node;
7255 complain &= ~tf_user;
7257 if (DECL_TEMPLATE_TEMPLATE_PARM_P (templ))
7259 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
7260 template arguments */
7266 parmlist = DECL_INNERMOST_TEMPLATE_PARMS (templ);
7268 /* Consider an example where a template template parameter declared as
7270 template <class T, class U = std::allocator<T> > class TT
7272 The template parameter level of T and U are one level larger than
7273 of TT. To proper process the default argument of U, say when an
7274 instantiation `TT<int>' is seen, we need to build the full
7275 arguments containing {int} as the innermost level. Outer levels,
7276 available when not appearing as default template argument, can be
7277 obtained from the arguments of the enclosing template.
7279 Suppose that TT is later substituted with std::vector. The above
7280 instantiation is `TT<int, std::allocator<T> >' with TT at
7281 level 1, and T at level 2, while the template arguments at level 1
7282 becomes {std::vector} and the inner level 2 is {int}. */
7284 outer = DECL_CONTEXT (templ);
7286 outer = TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (outer)));
7287 else if (current_template_parms)
7288 /* This is an argument of the current template, so we haven't set
7289 DECL_CONTEXT yet. */
7290 outer = current_template_args ();
7293 arglist = add_to_template_args (outer, arglist);
7295 arglist2 = coerce_template_parms (parmlist, arglist, templ,
7297 /*require_all_args=*/true,
7298 /*use_default_args=*/true);
7299 if (arglist2 == error_mark_node
7300 || (!uses_template_parms (arglist2)
7301 && check_instantiated_args (templ, arglist2, complain)))
7302 return error_mark_node;
7304 parm = bind_template_template_parm (TREE_TYPE (templ), arglist2);
7309 tree template_type = TREE_TYPE (templ);
7312 tree found = NULL_TREE;
7315 int is_dependent_type;
7316 int use_partial_inst_tmpl = false;
7318 if (template_type == error_mark_node)
7319 /* An error occured while building the template TEMPL, and a
7320 diagnostic has most certainly been emitted for that
7321 already. Let's propagate that error. */
7322 return error_mark_node;
7324 gen_tmpl = most_general_template (templ);
7325 parmlist = DECL_TEMPLATE_PARMS (gen_tmpl);
7326 parm_depth = TMPL_PARMS_DEPTH (parmlist);
7327 arg_depth = TMPL_ARGS_DEPTH (arglist);
7329 if (arg_depth == 1 && parm_depth > 1)
7331 /* We've been given an incomplete set of template arguments.
7334 template <class T> struct S1 {
7335 template <class U> struct S2 {};
7336 template <class U> struct S2<U*> {};
7339 we will be called with an ARGLIST of `U*', but the
7340 TEMPLATE will be `template <class T> template
7341 <class U> struct S1<T>::S2'. We must fill in the missing
7344 = add_outermost_template_args (TYPE_TI_ARGS (TREE_TYPE (templ)),
7346 arg_depth = TMPL_ARGS_DEPTH (arglist);
7349 /* Now we should have enough arguments. */
7350 gcc_assert (parm_depth == arg_depth);
7352 /* From here on, we're only interested in the most general
7355 /* Calculate the BOUND_ARGS. These will be the args that are
7356 actually tsubst'd into the definition to create the
7360 /* We have multiple levels of arguments to coerce, at once. */
7362 int saved_depth = TMPL_ARGS_DEPTH (arglist);
7364 tree bound_args = make_tree_vec (parm_depth);
7366 for (i = saved_depth,
7367 t = DECL_TEMPLATE_PARMS (gen_tmpl);
7368 i > 0 && t != NULL_TREE;
7369 --i, t = TREE_CHAIN (t))
7372 if (i == saved_depth)
7373 a = coerce_template_parms (TREE_VALUE (t),
7376 /*require_all_args=*/true,
7377 /*use_default_args=*/true);
7379 /* Outer levels should have already been coerced. */
7380 a = TMPL_ARGS_LEVEL (arglist, i);
7382 /* Don't process further if one of the levels fails. */
7383 if (a == error_mark_node)
7385 /* Restore the ARGLIST to its full size. */
7386 TREE_VEC_LENGTH (arglist) = saved_depth;
7387 return error_mark_node;
7390 SET_TMPL_ARGS_LEVEL (bound_args, i, a);
7392 /* We temporarily reduce the length of the ARGLIST so
7393 that coerce_template_parms will see only the arguments
7394 corresponding to the template parameters it is
7396 TREE_VEC_LENGTH (arglist)--;
7399 /* Restore the ARGLIST to its full size. */
7400 TREE_VEC_LENGTH (arglist) = saved_depth;
7402 arglist = bound_args;
7406 = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parmlist),
7407 INNERMOST_TEMPLATE_ARGS (arglist),
7410 /*require_all_args=*/true,
7411 /*use_default_args=*/true);
7413 if (arglist == error_mark_node)
7414 /* We were unable to bind the arguments. */
7415 return error_mark_node;
7417 /* In the scope of a template class, explicit references to the
7418 template class refer to the type of the template, not any
7419 instantiation of it. For example, in:
7421 template <class T> class C { void f(C<T>); }
7423 the `C<T>' is just the same as `C'. Outside of the
7424 class, however, such a reference is an instantiation. */
7426 || !PRIMARY_TEMPLATE_P (gen_tmpl)
7427 || currently_open_class (template_type))
7428 /* comp_template_args is expensive, check it last. */
7429 && comp_template_args (TYPE_TI_ARGS (template_type),
7431 return template_type;
7433 /* If we already have this specialization, return it. */
7434 elt.tmpl = gen_tmpl;
7436 hash = hash_specialization (&elt);
7437 entry = (spec_entry *) htab_find_with_hash (type_specializations,
7443 is_dependent_type = uses_template_parms (arglist);
7445 /* If the deduced arguments are invalid, then the binding
7447 if (!is_dependent_type
7448 && check_instantiated_args (gen_tmpl,
7449 INNERMOST_TEMPLATE_ARGS (arglist),
7451 return error_mark_node;
7453 if (!is_dependent_type
7454 && !PRIMARY_TEMPLATE_P (gen_tmpl)
7455 && !LAMBDA_TYPE_P (TREE_TYPE (gen_tmpl))
7456 && TREE_CODE (CP_DECL_CONTEXT (gen_tmpl)) == NAMESPACE_DECL)
7458 found = xref_tag_from_type (TREE_TYPE (gen_tmpl),
7459 DECL_NAME (gen_tmpl),
7460 /*tag_scope=*/ts_global);
7464 context = tsubst (DECL_CONTEXT (gen_tmpl), arglist,
7467 context = global_namespace;
7469 /* Create the type. */
7470 if (TREE_CODE (template_type) == ENUMERAL_TYPE)
7472 if (!is_dependent_type)
7474 set_current_access_from_decl (TYPE_NAME (template_type));
7475 t = start_enum (TYPE_IDENTIFIER (template_type), NULL_TREE,
7476 tsubst (ENUM_UNDERLYING_TYPE (template_type),
7477 arglist, complain, in_decl),
7478 SCOPED_ENUM_P (template_type), NULL);
7482 /* We don't want to call start_enum for this type, since
7483 the values for the enumeration constants may involve
7484 template parameters. And, no one should be interested
7485 in the enumeration constants for such a type. */
7486 t = cxx_make_type (ENUMERAL_TYPE);
7487 SET_SCOPED_ENUM_P (t, SCOPED_ENUM_P (template_type));
7489 SET_OPAQUE_ENUM_P (t, OPAQUE_ENUM_P (template_type));
7490 ENUM_FIXED_UNDERLYING_TYPE_P (t)
7491 = ENUM_FIXED_UNDERLYING_TYPE_P (template_type);
7493 else if (DECL_ALIAS_TEMPLATE_P (gen_tmpl))
7495 /* The user referred to a specialization of an alias
7496 template represented by GEN_TMPL.
7498 [temp.alias]/2 says:
7500 When a template-id refers to the specialization of an
7501 alias template, it is equivalent to the associated
7502 type obtained by substitution of its
7503 template-arguments for the template-parameters in the
7504 type-id of the alias template. */
7506 t = tsubst (TREE_TYPE (gen_tmpl), arglist, complain, in_decl);
7507 /* Note that the call above (by indirectly calling
7508 register_specialization in tsubst_decl) registers the
7509 TYPE_DECL representing the specialization of the alias
7510 template. So next time someone substitutes ARGLIST for
7511 the template parms into the alias template (GEN_TMPL),
7512 she'll get that TYPE_DECL back. */
7514 if (t == error_mark_node)
7517 else if (CLASS_TYPE_P (template_type))
7519 t = make_class_type (TREE_CODE (template_type));
7520 CLASSTYPE_DECLARED_CLASS (t)
7521 = CLASSTYPE_DECLARED_CLASS (template_type);
7522 SET_CLASSTYPE_IMPLICIT_INSTANTIATION (t);
7523 TYPE_FOR_JAVA (t) = TYPE_FOR_JAVA (template_type);
7525 /* A local class. Make sure the decl gets registered properly. */
7526 if (context == current_function_decl)
7527 pushtag (DECL_NAME (gen_tmpl), t, /*tag_scope=*/ts_current);
7529 if (comp_template_args (CLASSTYPE_TI_ARGS (template_type), arglist))
7530 /* This instantiation is another name for the primary
7531 template type. Set the TYPE_CANONICAL field
7533 TYPE_CANONICAL (t) = template_type;
7534 else if (any_template_arguments_need_structural_equality_p (arglist))
7535 /* Some of the template arguments require structural
7536 equality testing, so this template class requires
7537 structural equality testing. */
7538 SET_TYPE_STRUCTURAL_EQUALITY (t);
7543 /* If we called start_enum or pushtag above, this information
7544 will already be set up. */
7547 TYPE_CONTEXT (t) = FROB_CONTEXT (context);
7549 type_decl = create_implicit_typedef (DECL_NAME (gen_tmpl), t);
7550 DECL_CONTEXT (type_decl) = TYPE_CONTEXT (t);
7551 DECL_SOURCE_LOCATION (type_decl)
7552 = DECL_SOURCE_LOCATION (TYPE_STUB_DECL (template_type));
7555 type_decl = TYPE_NAME (t);
7557 if (CLASS_TYPE_P (template_type))
7559 TREE_PRIVATE (type_decl)
7560 = TREE_PRIVATE (TYPE_STUB_DECL (template_type));
7561 TREE_PROTECTED (type_decl)
7562 = TREE_PROTECTED (TYPE_STUB_DECL (template_type));
7563 if (CLASSTYPE_VISIBILITY_SPECIFIED (template_type))
7565 DECL_VISIBILITY_SPECIFIED (type_decl) = 1;
7566 DECL_VISIBILITY (type_decl) = CLASSTYPE_VISIBILITY (template_type);
7570 /* Let's consider the explicit specialization of a member
7571 of a class template specialization that is implicitely instantiated,
7576 template<class U> struct M {}; //#0
7581 struct S<int>::M<char> //#1
7585 [temp.expl.spec]/4 says this is valid.
7587 In this case, when we write:
7590 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7593 When we encounter #1, we want to store the partial instantiation
7594 of M (template<class T> S<int>::M<T>) in it's CLASSTYPE_TI_TEMPLATE.
7596 For all cases other than this "explicit specialization of member of a
7597 class template", we just want to store the most general template into
7598 the CLASSTYPE_TI_TEMPLATE of M.
7600 This case of "explicit specialization of member of a class template"
7602 1/ the enclosing class is an instantiation of, and therefore not
7603 the same as, the context of the most general template, and
7604 2/ we aren't looking at the partial instantiation itself, i.e.
7605 the innermost arguments are not the same as the innermost parms of
7606 the most general template.
7608 So it's only when 1/ and 2/ happens that we want to use the partial
7609 instantiation of the member template in lieu of its most general
7612 if (PRIMARY_TEMPLATE_P (gen_tmpl)
7613 && TMPL_ARGS_HAVE_MULTIPLE_LEVELS (arglist)
7614 /* the enclosing class must be an instantiation... */
7615 && CLASS_TYPE_P (context)
7616 && !same_type_p (context, DECL_CONTEXT (gen_tmpl)))
7618 tree partial_inst_args;
7619 TREE_VEC_LENGTH (arglist)--;
7620 ++processing_template_decl;
7622 tsubst (INNERMOST_TEMPLATE_ARGS
7623 (TYPE_TI_ARGS (TREE_TYPE (gen_tmpl))),
7624 arglist, complain, NULL_TREE);
7625 --processing_template_decl;
7626 TREE_VEC_LENGTH (arglist)++;
7627 use_partial_inst_tmpl =
7628 /*...and we must not be looking at the partial instantiation
7630 !comp_template_args (INNERMOST_TEMPLATE_ARGS (arglist),
7634 if (!use_partial_inst_tmpl)
7635 /* This case is easy; there are no member templates involved. */
7639 /* This is a full instantiation of a member template. Find
7640 the partial instantiation of which this is an instance. */
7642 /* Temporarily reduce by one the number of levels in the ARGLIST
7643 so as to avoid comparing the last set of arguments. */
7644 TREE_VEC_LENGTH (arglist)--;
7645 found = tsubst (gen_tmpl, arglist, complain, NULL_TREE);
7646 TREE_VEC_LENGTH (arglist)++;
7647 /* FOUND is either a proper class type, or an alias
7648 template specialization. In the later case, it's a
7649 TYPE_DECL, resulting from the substituting of arguments
7650 for parameters in the TYPE_DECL of the alias template
7651 done earlier. So be careful while getting the template
7653 found = TREE_CODE (found) == TYPE_DECL
7654 ? TYPE_TI_TEMPLATE (TREE_TYPE (found))
7655 : CLASSTYPE_TI_TEMPLATE (found);
7658 SET_TYPE_TEMPLATE_INFO (t, build_template_info (found, arglist));
7661 slot = htab_find_slot_with_hash (type_specializations,
7662 &elt, hash, INSERT);
7663 entry = ggc_alloc_spec_entry ();
7667 /* Note this use of the partial instantiation so we can check it
7668 later in maybe_process_partial_specialization. */
7669 DECL_TEMPLATE_INSTANTIATIONS (templ)
7670 = tree_cons (arglist, t,
7671 DECL_TEMPLATE_INSTANTIATIONS (templ));
7673 if (TREE_CODE (t) == ENUMERAL_TYPE && !is_dependent_type)
7674 /* Now that the type has been registered on the instantiations
7675 list, we set up the enumerators. Because the enumeration
7676 constants may involve the enumeration type itself, we make
7677 sure to register the type first, and then create the
7678 constants. That way, doing tsubst_expr for the enumeration
7679 constants won't result in recursive calls here; we'll find
7680 the instantiation and exit above. */
7681 tsubst_enum (template_type, t, arglist);
7683 if (CLASS_TYPE_P (template_type) && is_dependent_type)
7684 /* If the type makes use of template parameters, the
7685 code that generates debugging information will crash. */
7686 DECL_IGNORED_P (TYPE_STUB_DECL (t)) = 1;
7688 /* Possibly limit visibility based on template args. */
7689 TREE_PUBLIC (type_decl) = 1;
7690 determine_visibility (type_decl);
7696 /* Wrapper for lookup_template_class_1. */
7699 lookup_template_class (tree d1, tree arglist, tree in_decl, tree context,
7700 int entering_scope, tsubst_flags_t complain)
7703 timevar_push (TV_TEMPLATE_INST);
7704 ret = lookup_template_class_1 (d1, arglist, in_decl, context,
7705 entering_scope, complain);
7706 timevar_pop (TV_TEMPLATE_INST);
7714 /* True when we should also visit template parameters that occur in
7715 non-deduced contexts. */
7716 bool include_nondeduced_p;
7717 struct pointer_set_t *visited;
7720 /* Called from for_each_template_parm via walk_tree. */
7723 for_each_template_parm_r (tree *tp, int *walk_subtrees, void *d)
7726 struct pair_fn_data *pfd = (struct pair_fn_data *) d;
7727 tree_fn_t fn = pfd->fn;
7728 void *data = pfd->data;
7731 && (pfd->include_nondeduced_p || TREE_CODE (t) != TYPENAME_TYPE)
7732 && for_each_template_parm (TYPE_CONTEXT (t), fn, data, pfd->visited,
7733 pfd->include_nondeduced_p))
7734 return error_mark_node;
7736 switch (TREE_CODE (t))
7739 if (TYPE_PTRMEMFUNC_P (t))
7745 if (!TYPE_TEMPLATE_INFO (t))
7747 else if (for_each_template_parm (TI_ARGS (TYPE_TEMPLATE_INFO (t)),
7748 fn, data, pfd->visited,
7749 pfd->include_nondeduced_p))
7750 return error_mark_node;
7754 if (for_each_template_parm (TYPE_MIN_VALUE (t),
7755 fn, data, pfd->visited,
7756 pfd->include_nondeduced_p)
7757 || for_each_template_parm (TYPE_MAX_VALUE (t),
7758 fn, data, pfd->visited,
7759 pfd->include_nondeduced_p))
7760 return error_mark_node;
7764 /* Since we're not going to walk subtrees, we have to do this
7766 if (for_each_template_parm (TYPE_METHOD_BASETYPE (t), fn, data,
7767 pfd->visited, pfd->include_nondeduced_p))
7768 return error_mark_node;
7772 /* Check the return type. */
7773 if (for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
7774 pfd->include_nondeduced_p))
7775 return error_mark_node;
7777 /* Check the parameter types. Since default arguments are not
7778 instantiated until they are needed, the TYPE_ARG_TYPES may
7779 contain expressions that involve template parameters. But,
7780 no-one should be looking at them yet. And, once they're
7781 instantiated, they don't contain template parameters, so
7782 there's no point in looking at them then, either. */
7786 for (parm = TYPE_ARG_TYPES (t); parm; parm = TREE_CHAIN (parm))
7787 if (for_each_template_parm (TREE_VALUE (parm), fn, data,
7788 pfd->visited, pfd->include_nondeduced_p))
7789 return error_mark_node;
7791 /* Since we've already handled the TYPE_ARG_TYPES, we don't
7792 want walk_tree walking into them itself. */
7798 case UNDERLYING_TYPE:
7799 if (pfd->include_nondeduced_p
7800 && for_each_template_parm (TYPE_FIELDS (t), fn, data,
7802 pfd->include_nondeduced_p))
7803 return error_mark_node;
7808 if (DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t)
7809 && for_each_template_parm (DECL_TI_ARGS (t), fn, data,
7810 pfd->visited, pfd->include_nondeduced_p))
7811 return error_mark_node;
7816 if (TREE_CODE (t) == CONST_DECL && DECL_TEMPLATE_PARM_P (t)
7817 && for_each_template_parm (DECL_INITIAL (t), fn, data,
7818 pfd->visited, pfd->include_nondeduced_p))
7819 return error_mark_node;
7820 if (DECL_CONTEXT (t)
7821 && pfd->include_nondeduced_p
7822 && for_each_template_parm (DECL_CONTEXT (t), fn, data,
7823 pfd->visited, pfd->include_nondeduced_p))
7824 return error_mark_node;
7827 case BOUND_TEMPLATE_TEMPLATE_PARM:
7828 /* Record template parameters such as `T' inside `TT<T>'. */
7829 if (for_each_template_parm (TYPE_TI_ARGS (t), fn, data, pfd->visited,
7830 pfd->include_nondeduced_p))
7831 return error_mark_node;
7834 case TEMPLATE_TEMPLATE_PARM:
7835 case TEMPLATE_TYPE_PARM:
7836 case TEMPLATE_PARM_INDEX:
7837 if (fn && (*fn)(t, data))
7838 return error_mark_node;
7840 return error_mark_node;
7844 /* A template template parameter is encountered. */
7845 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t)
7846 && for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
7847 pfd->include_nondeduced_p))
7848 return error_mark_node;
7850 /* Already substituted template template parameter */
7856 || for_each_template_parm (TYPENAME_TYPE_FULLNAME (t), fn,
7858 pfd->include_nondeduced_p))
7859 return error_mark_node;
7863 if (TREE_TYPE (t) && TYPE_PTRMEMFUNC_P (TREE_TYPE (t))
7864 && pfd->include_nondeduced_p
7865 && for_each_template_parm (TYPE_PTRMEMFUNC_FN_TYPE
7866 (TREE_TYPE (t)), fn, data,
7867 pfd->visited, pfd->include_nondeduced_p))
7868 return error_mark_node;
7873 /* If there's no type, then this thing must be some expression
7874 involving template parameters. */
7875 if (!fn && !TREE_TYPE (t))
7876 return error_mark_node;
7881 case IMPLICIT_CONV_EXPR:
7882 case REINTERPRET_CAST_EXPR:
7883 case CONST_CAST_EXPR:
7884 case STATIC_CAST_EXPR:
7885 case DYNAMIC_CAST_EXPR:
7889 case PSEUDO_DTOR_EXPR:
7891 return error_mark_node;
7898 /* We didn't find any template parameters we liked. */
7902 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
7903 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
7904 call FN with the parameter and the DATA.
7905 If FN returns nonzero, the iteration is terminated, and
7906 for_each_template_parm returns 1. Otherwise, the iteration
7907 continues. If FN never returns a nonzero value, the value
7908 returned by for_each_template_parm is 0. If FN is NULL, it is
7909 considered to be the function which always returns 1.
7911 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
7912 parameters that occur in non-deduced contexts. When false, only
7913 visits those template parameters that can be deduced. */
7916 for_each_template_parm (tree t, tree_fn_t fn, void* data,
7917 struct pointer_set_t *visited,
7918 bool include_nondeduced_p)
7920 struct pair_fn_data pfd;
7926 pfd.include_nondeduced_p = include_nondeduced_p;
7928 /* Walk the tree. (Conceptually, we would like to walk without
7929 duplicates, but for_each_template_parm_r recursively calls
7930 for_each_template_parm, so we would need to reorganize a fair
7931 bit to use walk_tree_without_duplicates, so we keep our own
7934 pfd.visited = visited;
7936 pfd.visited = pointer_set_create ();
7937 result = cp_walk_tree (&t,
7938 for_each_template_parm_r,
7940 pfd.visited) != NULL_TREE;
7945 pointer_set_destroy (pfd.visited);
7952 /* Returns true if T depends on any template parameter. */
7955 uses_template_parms (tree t)
7958 int saved_processing_template_decl;
7960 saved_processing_template_decl = processing_template_decl;
7961 if (!saved_processing_template_decl)
7962 processing_template_decl = 1;
7964 dependent_p = dependent_type_p (t);
7965 else if (TREE_CODE (t) == TREE_VEC)
7966 dependent_p = any_dependent_template_arguments_p (t);
7967 else if (TREE_CODE (t) == TREE_LIST)
7968 dependent_p = (uses_template_parms (TREE_VALUE (t))
7969 || uses_template_parms (TREE_CHAIN (t)));
7970 else if (TREE_CODE (t) == TYPE_DECL)
7971 dependent_p = dependent_type_p (TREE_TYPE (t));
7974 || TREE_CODE (t) == TEMPLATE_PARM_INDEX
7975 || TREE_CODE (t) == OVERLOAD
7977 || TREE_CODE (t) == IDENTIFIER_NODE
7978 || TREE_CODE (t) == TRAIT_EXPR
7979 || TREE_CODE (t) == CONSTRUCTOR
7980 || CONSTANT_CLASS_P (t))
7981 dependent_p = (type_dependent_expression_p (t)
7982 || value_dependent_expression_p (t));
7985 gcc_assert (t == error_mark_node);
7986 dependent_p = false;
7989 processing_template_decl = saved_processing_template_decl;
7994 /* Returns true if T depends on any template parameter with level LEVEL. */
7997 uses_template_parms_level (tree t, int level)
7999 return for_each_template_parm (t, template_parm_this_level_p, &level, NULL,
8000 /*include_nondeduced_p=*/true);
8003 /* Returns TRUE iff INST is an instantiation we don't need to do in an
8004 ill-formed translation unit, i.e. a variable or function that isn't
8005 usable in a constant expression. */
8008 neglectable_inst_p (tree d)
8011 && !(TREE_CODE (d) == FUNCTION_DECL ? DECL_DECLARED_CONSTEXPR_P (d)
8012 : decl_maybe_constant_var_p (d)));
8015 /* Returns TRUE iff we should refuse to instantiate DECL because it's
8016 neglectable and instantiated from within an erroneous instantiation. */
8019 limit_bad_template_recursion (tree decl)
8021 struct tinst_level *lev = current_tinst_level;
8022 int errs = errorcount + sorrycount;
8023 if (lev == NULL || errs == 0 || !neglectable_inst_p (decl))
8026 for (; lev; lev = lev->next)
8027 if (neglectable_inst_p (lev->decl))
8030 return (lev && errs > lev->errors);
8033 static int tinst_depth;
8034 extern int max_tinst_depth;
8035 #ifdef GATHER_STATISTICS
8038 static GTY(()) struct tinst_level *last_error_tinst_level;
8040 /* We're starting to instantiate D; record the template instantiation context
8041 for diagnostics and to restore it later. */
8044 push_tinst_level (tree d)
8046 struct tinst_level *new_level;
8048 if (tinst_depth >= max_tinst_depth)
8050 last_error_tinst_level = current_tinst_level;
8051 if (TREE_CODE (d) == TREE_LIST)
8052 error ("template instantiation depth exceeds maximum of %d (use "
8053 "-ftemplate-depth= to increase the maximum) substituting %qS",
8054 max_tinst_depth, d);
8056 error ("template instantiation depth exceeds maximum of %d (use "
8057 "-ftemplate-depth= to increase the maximum) instantiating %qD",
8058 max_tinst_depth, d);
8060 print_instantiation_context ();
8065 /* If the current instantiation caused problems, don't let it instantiate
8066 anything else. Do allow deduction substitution and decls usable in
8067 constant expressions. */
8068 if (limit_bad_template_recursion (d))
8071 new_level = ggc_alloc_tinst_level ();
8072 new_level->decl = d;
8073 new_level->locus = input_location;
8074 new_level->errors = errorcount+sorrycount;
8075 new_level->in_system_header_p = in_system_header;
8076 new_level->next = current_tinst_level;
8077 current_tinst_level = new_level;
8080 #ifdef GATHER_STATISTICS
8081 if (tinst_depth > depth_reached)
8082 depth_reached = tinst_depth;
8088 /* We're done instantiating this template; return to the instantiation
8092 pop_tinst_level (void)
8094 /* Restore the filename and line number stashed away when we started
8095 this instantiation. */
8096 input_location = current_tinst_level->locus;
8097 current_tinst_level = current_tinst_level->next;
8101 /* We're instantiating a deferred template; restore the template
8102 instantiation context in which the instantiation was requested, which
8103 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
8106 reopen_tinst_level (struct tinst_level *level)
8108 struct tinst_level *t;
8111 for (t = level; t; t = t->next)
8114 current_tinst_level = level;
8116 if (current_tinst_level)
8117 current_tinst_level->errors = errorcount+sorrycount;
8121 /* Returns the TINST_LEVEL which gives the original instantiation
8124 struct tinst_level *
8125 outermost_tinst_level (void)
8127 struct tinst_level *level = current_tinst_level;
8130 level = level->next;
8134 /* Returns TRUE if PARM is a parameter of the template TEMPL. */
8137 parameter_of_template_p (tree parm, tree templ)
8142 if (!parm || !templ)
8145 gcc_assert (DECL_TEMPLATE_PARM_P (parm));
8146 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
8148 parms = DECL_TEMPLATE_PARMS (templ);
8149 parms = INNERMOST_TEMPLATE_PARMS (parms);
8151 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
8153 tree p = TREE_VALUE (TREE_VEC_ELT (parms, i));
8155 || (DECL_INITIAL (parm)
8156 && DECL_INITIAL (parm) == DECL_INITIAL (p)))
8163 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
8164 vector of template arguments, as for tsubst.
8166 Returns an appropriate tsubst'd friend declaration. */
8169 tsubst_friend_function (tree decl, tree args)
8173 if (TREE_CODE (decl) == FUNCTION_DECL
8174 && DECL_TEMPLATE_INSTANTIATION (decl)
8175 && TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
8176 /* This was a friend declared with an explicit template
8177 argument list, e.g.:
8181 to indicate that f was a template instantiation, not a new
8182 function declaration. Now, we have to figure out what
8183 instantiation of what template. */
8185 tree template_id, arglist, fns;
8188 tree ns = decl_namespace_context (TYPE_MAIN_DECL (current_class_type));
8190 /* Friend functions are looked up in the containing namespace scope.
8191 We must enter that scope, to avoid finding member functions of the
8192 current class with same name. */
8193 push_nested_namespace (ns);
8194 fns = tsubst_expr (DECL_TI_TEMPLATE (decl), args,
8195 tf_warning_or_error, NULL_TREE,
8196 /*integral_constant_expression_p=*/false);
8197 pop_nested_namespace (ns);
8198 arglist = tsubst (DECL_TI_ARGS (decl), args,
8199 tf_warning_or_error, NULL_TREE);
8200 template_id = lookup_template_function (fns, arglist);
8202 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
8203 tmpl = determine_specialization (template_id, new_friend,
8205 /*need_member_template=*/0,
8206 TREE_VEC_LENGTH (args),
8208 return instantiate_template (tmpl, new_args, tf_error);
8211 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
8213 /* The NEW_FRIEND will look like an instantiation, to the
8214 compiler, but is not an instantiation from the point of view of
8215 the language. For example, we might have had:
8217 template <class T> struct S {
8218 template <class U> friend void f(T, U);
8221 Then, in S<int>, template <class U> void f(int, U) is not an
8222 instantiation of anything. */
8223 if (new_friend == error_mark_node)
8224 return error_mark_node;
8226 DECL_USE_TEMPLATE (new_friend) = 0;
8227 if (TREE_CODE (decl) == TEMPLATE_DECL)
8229 DECL_USE_TEMPLATE (DECL_TEMPLATE_RESULT (new_friend)) = 0;
8230 DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (new_friend))
8231 = DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (decl));
8234 /* The mangled name for the NEW_FRIEND is incorrect. The function
8235 is not a template instantiation and should not be mangled like
8236 one. Therefore, we forget the mangling here; we'll recompute it
8237 later if we need it. */
8238 if (TREE_CODE (new_friend) != TEMPLATE_DECL)
8240 SET_DECL_RTL (new_friend, NULL);
8241 SET_DECL_ASSEMBLER_NAME (new_friend, NULL_TREE);
8244 if (DECL_NAMESPACE_SCOPE_P (new_friend))
8247 tree new_friend_template_info;
8248 tree new_friend_result_template_info;
8250 int new_friend_is_defn;
8252 /* We must save some information from NEW_FRIEND before calling
8253 duplicate decls since that function will free NEW_FRIEND if
8255 new_friend_template_info = DECL_TEMPLATE_INFO (new_friend);
8256 new_friend_is_defn =
8257 (DECL_INITIAL (DECL_TEMPLATE_RESULT
8258 (template_for_substitution (new_friend)))
8260 if (TREE_CODE (new_friend) == TEMPLATE_DECL)
8262 /* This declaration is a `primary' template. */
8263 DECL_PRIMARY_TEMPLATE (new_friend) = new_friend;
8265 new_friend_result_template_info
8266 = DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (new_friend));
8269 new_friend_result_template_info = NULL_TREE;
8271 /* Make the init_value nonzero so pushdecl knows this is a defn. */
8272 if (new_friend_is_defn)
8273 DECL_INITIAL (new_friend) = error_mark_node;
8275 /* Inside pushdecl_namespace_level, we will push into the
8276 current namespace. However, the friend function should go
8277 into the namespace of the template. */
8278 ns = decl_namespace_context (new_friend);
8279 push_nested_namespace (ns);
8280 old_decl = pushdecl_namespace_level (new_friend, /*is_friend=*/true);
8281 pop_nested_namespace (ns);
8283 if (old_decl == error_mark_node)
8284 return error_mark_node;
8286 if (old_decl != new_friend)
8288 /* This new friend declaration matched an existing
8289 declaration. For example, given:
8291 template <class T> void f(T);
8292 template <class U> class C {
8293 template <class T> friend void f(T) {}
8296 the friend declaration actually provides the definition
8297 of `f', once C has been instantiated for some type. So,
8298 old_decl will be the out-of-class template declaration,
8299 while new_friend is the in-class definition.
8301 But, if `f' was called before this point, the
8302 instantiation of `f' will have DECL_TI_ARGS corresponding
8303 to `T' but not to `U', references to which might appear
8304 in the definition of `f'. Previously, the most general
8305 template for an instantiation of `f' was the out-of-class
8306 version; now it is the in-class version. Therefore, we
8307 run through all specialization of `f', adding to their
8308 DECL_TI_ARGS appropriately. In particular, they need a
8309 new set of outer arguments, corresponding to the
8310 arguments for this class instantiation.
8312 The same situation can arise with something like this:
8315 template <class T> class C {
8319 when `C<int>' is instantiated. Now, `f(int)' is defined
8322 if (!new_friend_is_defn)
8323 /* On the other hand, if the in-class declaration does
8324 *not* provide a definition, then we don't want to alter
8325 existing definitions. We can just leave everything
8330 tree new_template = TI_TEMPLATE (new_friend_template_info);
8331 tree new_args = TI_ARGS (new_friend_template_info);
8333 /* Overwrite whatever template info was there before, if
8334 any, with the new template information pertaining to
8336 DECL_TEMPLATE_INFO (old_decl) = new_friend_template_info;
8338 if (TREE_CODE (old_decl) != TEMPLATE_DECL)
8340 /* We should have called reregister_specialization in
8342 gcc_assert (retrieve_specialization (new_template,
8346 /* Instantiate it if the global has already been used. */
8347 if (DECL_ODR_USED (old_decl))
8348 instantiate_decl (old_decl, /*defer_ok=*/true,
8349 /*expl_inst_class_mem_p=*/false);
8355 /* Indicate that the old function template is a partial
8357 DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (old_decl))
8358 = new_friend_result_template_info;
8360 gcc_assert (new_template
8361 == most_general_template (new_template));
8362 gcc_assert (new_template != old_decl);
8364 /* Reassign any specializations already in the hash table
8365 to the new more general template, and add the
8366 additional template args. */
8367 for (t = DECL_TEMPLATE_INSTANTIATIONS (old_decl);
8371 tree spec = TREE_VALUE (t);
8374 elt.tmpl = old_decl;
8375 elt.args = DECL_TI_ARGS (spec);
8376 elt.spec = NULL_TREE;
8378 htab_remove_elt (decl_specializations, &elt);
8381 = add_outermost_template_args (new_args,
8382 DECL_TI_ARGS (spec));
8384 register_specialization
8385 (spec, new_template, DECL_TI_ARGS (spec), true, 0);
8388 DECL_TEMPLATE_INSTANTIATIONS (old_decl) = NULL_TREE;
8392 /* The information from NEW_FRIEND has been merged into OLD_DECL
8393 by duplicate_decls. */
8394 new_friend = old_decl;
8399 tree context = DECL_CONTEXT (new_friend);
8403 template <class T> class C {
8404 template <class U> friend void C1<U>::f (); // case 1
8405 friend void C2<T>::f (); // case 2
8407 we only need to make sure CONTEXT is a complete type for
8408 case 2. To distinguish between the two cases, we note that
8409 CONTEXT of case 1 remains dependent type after tsubst while
8410 this isn't true for case 2. */
8411 ++processing_template_decl;
8412 dependent_p = dependent_type_p (context);
8413 --processing_template_decl;
8416 && !complete_type_or_else (context, NULL_TREE))
8417 return error_mark_node;
8419 if (COMPLETE_TYPE_P (context))
8421 /* Check to see that the declaration is really present, and,
8422 possibly obtain an improved declaration. */
8423 tree fn = check_classfn (context,
8424 new_friend, NULL_TREE);
8434 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
8435 template arguments, as for tsubst.
8437 Returns an appropriate tsubst'd friend type or error_mark_node on
8441 tsubst_friend_class (tree friend_tmpl, tree args)
8447 context = CP_DECL_CONTEXT (friend_tmpl);
8449 if (context != global_namespace)
8451 if (TREE_CODE (context) == NAMESPACE_DECL)
8452 push_nested_namespace (context);
8454 push_nested_class (tsubst (context, args, tf_none, NULL_TREE));
8457 /* Look for a class template declaration. We look for hidden names
8458 because two friend declarations of the same template are the
8459 same. For example, in:
8462 template <typename> friend class F;
8464 template <typename> struct B {
8465 template <typename> friend class F;
8468 both F templates are the same. */
8469 tmpl = lookup_name_real (DECL_NAME (friend_tmpl), 0, 0,
8470 /*block_p=*/true, 0,
8471 LOOKUP_COMPLAIN | LOOKUP_HIDDEN);
8473 /* But, if we don't find one, it might be because we're in a
8474 situation like this:
8482 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
8483 for `S<int>', not the TEMPLATE_DECL. */
8484 if (!tmpl || !DECL_CLASS_TEMPLATE_P (tmpl))
8486 tmpl = lookup_name_prefer_type (DECL_NAME (friend_tmpl), 1);
8487 tmpl = maybe_get_template_decl_from_type_decl (tmpl);
8490 if (tmpl && DECL_CLASS_TEMPLATE_P (tmpl))
8492 /* The friend template has already been declared. Just
8493 check to see that the declarations match, and install any new
8494 default parameters. We must tsubst the default parameters,
8495 of course. We only need the innermost template parameters
8496 because that is all that redeclare_class_template will look
8498 if (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (friend_tmpl))
8499 > TMPL_ARGS_DEPTH (args))
8502 location_t saved_input_location;
8503 parms = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_tmpl),
8504 args, tf_warning_or_error);
8506 saved_input_location = input_location;
8507 input_location = DECL_SOURCE_LOCATION (friend_tmpl);
8508 redeclare_class_template (TREE_TYPE (tmpl), parms);
8509 input_location = saved_input_location;
8513 friend_type = TREE_TYPE (tmpl);
8517 /* The friend template has not already been declared. In this
8518 case, the instantiation of the template class will cause the
8519 injection of this template into the global scope. */
8520 tmpl = tsubst (friend_tmpl, args, tf_warning_or_error, NULL_TREE);
8521 if (tmpl == error_mark_node)
8522 return error_mark_node;
8524 /* The new TMPL is not an instantiation of anything, so we
8525 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
8526 the new type because that is supposed to be the corresponding
8527 template decl, i.e., TMPL. */
8528 DECL_USE_TEMPLATE (tmpl) = 0;
8529 DECL_TEMPLATE_INFO (tmpl) = NULL_TREE;
8530 CLASSTYPE_USE_TEMPLATE (TREE_TYPE (tmpl)) = 0;
8531 CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl))
8532 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl)));
8534 /* Inject this template into the global scope. */
8535 friend_type = TREE_TYPE (pushdecl_top_level_maybe_friend (tmpl, true));
8538 if (context != global_namespace)
8540 if (TREE_CODE (context) == NAMESPACE_DECL)
8541 pop_nested_namespace (context);
8543 pop_nested_class ();
8549 /* Returns zero if TYPE cannot be completed later due to circularity.
8550 Otherwise returns one. */
8553 can_complete_type_without_circularity (tree type)
8555 if (type == NULL_TREE || type == error_mark_node)
8557 else if (COMPLETE_TYPE_P (type))
8559 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
8560 return can_complete_type_without_circularity (TREE_TYPE (type));
8561 else if (CLASS_TYPE_P (type)
8562 && TYPE_BEING_DEFINED (TYPE_MAIN_VARIANT (type)))
8568 /* Apply any attributes which had to be deferred until instantiation
8569 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
8570 ARGS, COMPLAIN, IN_DECL are as tsubst. */
8573 apply_late_template_attributes (tree *decl_p, tree attributes, int attr_flags,
8574 tree args, tsubst_flags_t complain, tree in_decl)
8576 tree last_dep = NULL_TREE;
8580 for (t = attributes; t; t = TREE_CHAIN (t))
8581 if (ATTR_IS_DEPENDENT (t))
8584 attributes = copy_list (attributes);
8588 if (DECL_P (*decl_p))
8590 if (TREE_TYPE (*decl_p) == error_mark_node)
8592 p = &DECL_ATTRIBUTES (*decl_p);
8595 p = &TYPE_ATTRIBUTES (*decl_p);
8599 tree late_attrs = NULL_TREE;
8600 tree *q = &late_attrs;
8602 for (*p = attributes; *p; )
8605 if (ATTR_IS_DEPENDENT (t))
8607 *p = TREE_CHAIN (t);
8608 TREE_CHAIN (t) = NULL_TREE;
8609 /* If the first attribute argument is an identifier, don't
8610 pass it through tsubst. Attributes like mode, format,
8611 cleanup and several target specific attributes expect it
8614 && TREE_CODE (TREE_VALUE (t)) == TREE_LIST
8615 && TREE_VALUE (TREE_VALUE (t))
8616 && (TREE_CODE (TREE_VALUE (TREE_VALUE (t)))
8617 == IDENTIFIER_NODE))
8620 = tsubst_expr (TREE_CHAIN (TREE_VALUE (t)), args, complain,
8622 /*integral_constant_expression_p=*/false);
8623 if (chain != TREE_CHAIN (TREE_VALUE (t)))
8625 = tree_cons (NULL_TREE, TREE_VALUE (TREE_VALUE (t)),
8630 = tsubst_expr (TREE_VALUE (t), args, complain, in_decl,
8631 /*integral_constant_expression_p=*/false);
8633 q = &TREE_CHAIN (t);
8636 p = &TREE_CHAIN (t);
8639 cplus_decl_attributes (decl_p, late_attrs, attr_flags);
8643 /* Perform (or defer) access check for typedefs that were referenced
8644 from within the template TMPL code.
8645 This is a subroutine of instantiate_template and instantiate_class_template.
8646 TMPL is the template to consider and TARGS is the list of arguments of
8650 perform_typedefs_access_check (tree tmpl, tree targs)
8652 location_t saved_location;
8654 qualified_typedef_usage_t *iter;
8657 || (!CLASS_TYPE_P (tmpl)
8658 && TREE_CODE (tmpl) != FUNCTION_DECL))
8661 saved_location = input_location;
8662 FOR_EACH_VEC_ELT (qualified_typedef_usage_t,
8663 get_types_needing_access_check (tmpl),
8666 tree type_decl = iter->typedef_decl;
8667 tree type_scope = iter->context;
8669 if (!type_decl || !type_scope || !CLASS_TYPE_P (type_scope))
8672 if (uses_template_parms (type_decl))
8673 type_decl = tsubst (type_decl, targs, tf_error, NULL_TREE);
8674 if (uses_template_parms (type_scope))
8675 type_scope = tsubst (type_scope, targs, tf_error, NULL_TREE);
8677 /* Make access check error messages point to the location
8678 of the use of the typedef. */
8679 input_location = iter->locus;
8680 perform_or_defer_access_check (TYPE_BINFO (type_scope),
8681 type_decl, type_decl);
8683 input_location = saved_location;
8687 instantiate_class_template_1 (tree type)
8689 tree templ, args, pattern, t, member;
8693 unsigned int saved_maximum_field_alignment;
8695 if (type == error_mark_node)
8696 return error_mark_node;
8698 if (COMPLETE_OR_OPEN_TYPE_P (type)
8699 || uses_template_parms (type))
8702 /* Figure out which template is being instantiated. */
8703 templ = most_general_template (CLASSTYPE_TI_TEMPLATE (type));
8704 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
8706 /* Determine what specialization of the original template to
8708 t = most_specialized_class (type, templ, tf_warning_or_error);
8709 if (t == error_mark_node)
8711 TYPE_BEING_DEFINED (type) = 1;
8712 return error_mark_node;
8716 /* This TYPE is actually an instantiation of a partial
8717 specialization. We replace the innermost set of ARGS with
8718 the arguments appropriate for substitution. For example,
8721 template <class T> struct S {};
8722 template <class T> struct S<T*> {};
8724 and supposing that we are instantiating S<int*>, ARGS will
8725 presently be {int*} -- but we need {int}. */
8726 pattern = TREE_TYPE (t);
8727 args = TREE_PURPOSE (t);
8731 pattern = TREE_TYPE (templ);
8732 args = CLASSTYPE_TI_ARGS (type);
8735 /* If the template we're instantiating is incomplete, then clearly
8736 there's nothing we can do. */
8737 if (!COMPLETE_TYPE_P (pattern))
8740 /* If we've recursively instantiated too many templates, stop. */
8741 if (! push_tinst_level (type))
8744 /* Now we're really doing the instantiation. Mark the type as in
8745 the process of being defined. */
8746 TYPE_BEING_DEFINED (type) = 1;
8748 /* We may be in the middle of deferred access check. Disable
8750 push_deferring_access_checks (dk_no_deferred);
8752 push_to_top_level ();
8753 /* Use #pragma pack from the template context. */
8754 saved_maximum_field_alignment = maximum_field_alignment;
8755 maximum_field_alignment = TYPE_PRECISION (pattern);
8757 SET_CLASSTYPE_INTERFACE_UNKNOWN (type);
8759 /* Set the input location to the most specialized template definition.
8760 This is needed if tsubsting causes an error. */
8761 typedecl = TYPE_MAIN_DECL (pattern);
8762 input_location = DECL_SOURCE_LOCATION (TYPE_NAME (type)) =
8763 DECL_SOURCE_LOCATION (typedecl);
8765 TYPE_PACKED (type) = TYPE_PACKED (pattern);
8766 TYPE_ALIGN (type) = TYPE_ALIGN (pattern);
8767 TYPE_USER_ALIGN (type) = TYPE_USER_ALIGN (pattern);
8768 TYPE_FOR_JAVA (type) = TYPE_FOR_JAVA (pattern); /* For libjava's JArray<T> */
8769 if (ANON_AGGR_TYPE_P (pattern))
8770 SET_ANON_AGGR_TYPE_P (type);
8771 if (CLASSTYPE_VISIBILITY_SPECIFIED (pattern))
8773 CLASSTYPE_VISIBILITY_SPECIFIED (type) = 1;
8774 CLASSTYPE_VISIBILITY (type) = CLASSTYPE_VISIBILITY (pattern);
8775 /* Adjust visibility for template arguments. */
8776 determine_visibility (TYPE_MAIN_DECL (type));
8778 CLASSTYPE_FINAL (type) = CLASSTYPE_FINAL (pattern);
8780 pbinfo = TYPE_BINFO (pattern);
8782 /* We should never instantiate a nested class before its enclosing
8783 class; we need to look up the nested class by name before we can
8784 instantiate it, and that lookup should instantiate the enclosing
8786 gcc_assert (!DECL_CLASS_SCOPE_P (TYPE_MAIN_DECL (pattern))
8787 || COMPLETE_OR_OPEN_TYPE_P (TYPE_CONTEXT (type)));
8789 base_list = NULL_TREE;
8790 if (BINFO_N_BASE_BINFOS (pbinfo))
8796 /* We must enter the scope containing the type, as that is where
8797 the accessibility of types named in dependent bases are
8799 pushed_scope = push_scope (CP_TYPE_CONTEXT (type));
8801 /* Substitute into each of the bases to determine the actual
8803 for (i = 0; BINFO_BASE_ITERATE (pbinfo, i, pbase_binfo); i++)
8806 tree access = BINFO_BASE_ACCESS (pbinfo, i);
8807 tree expanded_bases = NULL_TREE;
8810 if (PACK_EXPANSION_P (BINFO_TYPE (pbase_binfo)))
8813 tsubst_pack_expansion (BINFO_TYPE (pbase_binfo),
8814 args, tf_error, NULL_TREE);
8815 if (expanded_bases == error_mark_node)
8818 len = TREE_VEC_LENGTH (expanded_bases);
8821 for (idx = 0; idx < len; idx++)
8824 /* Extract the already-expanded base class. */
8825 base = TREE_VEC_ELT (expanded_bases, idx);
8827 /* Substitute to figure out the base class. */
8828 base = tsubst (BINFO_TYPE (pbase_binfo), args, tf_error,
8831 if (base == error_mark_node)
8834 base_list = tree_cons (access, base, base_list);
8835 if (BINFO_VIRTUAL_P (pbase_binfo))
8836 TREE_TYPE (base_list) = integer_type_node;
8840 /* The list is now in reverse order; correct that. */
8841 base_list = nreverse (base_list);
8844 pop_scope (pushed_scope);
8846 /* Now call xref_basetypes to set up all the base-class
8848 xref_basetypes (type, base_list);
8850 apply_late_template_attributes (&type, TYPE_ATTRIBUTES (pattern),
8851 (int) ATTR_FLAG_TYPE_IN_PLACE,
8852 args, tf_error, NULL_TREE);
8853 fixup_attribute_variants (type);
8855 /* Now that our base classes are set up, enter the scope of the
8856 class, so that name lookups into base classes, etc. will work
8857 correctly. This is precisely analogous to what we do in
8858 begin_class_definition when defining an ordinary non-template
8859 class, except we also need to push the enclosing classes. */
8860 push_nested_class (type);
8862 /* Now members are processed in the order of declaration. */
8863 for (member = CLASSTYPE_DECL_LIST (pattern);
8864 member; member = TREE_CHAIN (member))
8866 tree t = TREE_VALUE (member);
8868 if (TREE_PURPOSE (member))
8872 /* Build new CLASSTYPE_NESTED_UTDS. */
8875 bool class_template_p;
8877 class_template_p = (TREE_CODE (t) != ENUMERAL_TYPE
8878 && TYPE_LANG_SPECIFIC (t)
8879 && CLASSTYPE_IS_TEMPLATE (t));
8880 /* If the member is a class template, then -- even after
8881 substitution -- there may be dependent types in the
8882 template argument list for the class. We increment
8883 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
8884 that function will assume that no types are dependent
8885 when outside of a template. */
8886 if (class_template_p)
8887 ++processing_template_decl;
8888 newtag = tsubst (t, args, tf_error, NULL_TREE);
8889 if (class_template_p)
8890 --processing_template_decl;
8891 if (newtag == error_mark_node)
8894 if (TREE_CODE (newtag) != ENUMERAL_TYPE)
8896 tree name = TYPE_IDENTIFIER (t);
8898 if (class_template_p)
8899 /* Unfortunately, lookup_template_class sets
8900 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
8901 instantiation (i.e., for the type of a member
8902 template class nested within a template class.)
8903 This behavior is required for
8904 maybe_process_partial_specialization to work
8905 correctly, but is not accurate in this case;
8906 the TAG is not an instantiation of anything.
8907 (The corresponding TEMPLATE_DECL is an
8908 instantiation, but the TYPE is not.) */
8909 CLASSTYPE_USE_TEMPLATE (newtag) = 0;
8911 /* Now, we call pushtag to put this NEWTAG into the scope of
8912 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
8913 pushtag calling push_template_decl. We don't have to do
8914 this for enums because it will already have been done in
8917 SET_IDENTIFIER_TYPE_VALUE (name, newtag);
8918 pushtag (name, newtag, /*tag_scope=*/ts_current);
8921 else if (TREE_CODE (t) == FUNCTION_DECL
8922 || DECL_FUNCTION_TEMPLATE_P (t))
8924 /* Build new TYPE_METHODS. */
8927 if (TREE_CODE (t) == TEMPLATE_DECL)
8928 ++processing_template_decl;
8929 r = tsubst (t, args, tf_error, NULL_TREE);
8930 if (TREE_CODE (t) == TEMPLATE_DECL)
8931 --processing_template_decl;
8932 set_current_access_from_decl (r);
8933 finish_member_declaration (r);
8934 /* Instantiate members marked with attribute used. */
8935 if (r != error_mark_node && DECL_PRESERVE_P (r))
8940 /* Build new TYPE_FIELDS. */
8941 if (TREE_CODE (t) == STATIC_ASSERT)
8944 tsubst_expr (STATIC_ASSERT_CONDITION (t), args,
8945 tf_warning_or_error, NULL_TREE,
8946 /*integral_constant_expression_p=*/true);
8947 finish_static_assert (condition,
8948 STATIC_ASSERT_MESSAGE (t),
8949 STATIC_ASSERT_SOURCE_LOCATION (t),
8952 else if (TREE_CODE (t) != CONST_DECL)
8956 /* The file and line for this declaration, to
8957 assist in error message reporting. Since we
8958 called push_tinst_level above, we don't need to
8960 input_location = DECL_SOURCE_LOCATION (t);
8962 if (TREE_CODE (t) == TEMPLATE_DECL)
8963 ++processing_template_decl;
8964 r = tsubst (t, args, tf_warning_or_error, NULL_TREE);
8965 if (TREE_CODE (t) == TEMPLATE_DECL)
8966 --processing_template_decl;
8967 if (TREE_CODE (r) == VAR_DECL)
8971 [t]he initialization (and any associated
8972 side-effects) of a static data member does
8973 not occur unless the static data member is
8974 itself used in a way that requires the
8975 definition of the static data member to
8978 Therefore, we do not substitute into the
8979 initialized for the static data member here. */
8980 finish_static_data_member_decl
8983 /*init_const_expr_p=*/false,
8984 /*asmspec_tree=*/NULL_TREE,
8986 /* Instantiate members marked with attribute used. */
8987 if (r != error_mark_node && DECL_PRESERVE_P (r))
8990 else if (TREE_CODE (r) == FIELD_DECL)
8992 /* Determine whether R has a valid type and can be
8993 completed later. If R is invalid, then it is
8994 replaced by error_mark_node so that it will not be
8995 added to TYPE_FIELDS. */
8996 tree rtype = TREE_TYPE (r);
8997 if (can_complete_type_without_circularity (rtype))
8998 complete_type (rtype);
9000 if (!COMPLETE_TYPE_P (rtype))
9002 cxx_incomplete_type_error (r, rtype);
9003 r = error_mark_node;
9007 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
9008 such a thing will already have been added to the field
9009 list by tsubst_enum in finish_member_declaration in the
9010 CLASSTYPE_NESTED_UTDS case above. */
9011 if (!(TREE_CODE (r) == TYPE_DECL
9012 && TREE_CODE (TREE_TYPE (r)) == ENUMERAL_TYPE
9013 && DECL_ARTIFICIAL (r)))
9015 set_current_access_from_decl (r);
9016 finish_member_declaration (r);
9023 if (TYPE_P (t) || DECL_CLASS_TEMPLATE_P (t))
9025 /* Build new CLASSTYPE_FRIEND_CLASSES. */
9027 tree friend_type = t;
9028 bool adjust_processing_template_decl = false;
9030 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
9032 /* template <class T> friend class C; */
9033 friend_type = tsubst_friend_class (friend_type, args);
9034 adjust_processing_template_decl = true;
9036 else if (TREE_CODE (friend_type) == UNBOUND_CLASS_TEMPLATE)
9038 /* template <class T> friend class C::D; */
9039 friend_type = tsubst (friend_type, args,
9040 tf_warning_or_error, NULL_TREE);
9041 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
9042 friend_type = TREE_TYPE (friend_type);
9043 adjust_processing_template_decl = true;
9045 else if (TREE_CODE (friend_type) == TYPENAME_TYPE
9046 || TREE_CODE (friend_type) == TEMPLATE_TYPE_PARM)
9048 /* This could be either
9052 when dependent_type_p is false or
9054 template <class U> friend class T::C;
9057 friend_type = tsubst (friend_type, args,
9058 tf_warning_or_error, NULL_TREE);
9059 /* Bump processing_template_decl for correct
9060 dependent_type_p calculation. */
9061 ++processing_template_decl;
9062 if (dependent_type_p (friend_type))
9063 adjust_processing_template_decl = true;
9064 --processing_template_decl;
9066 else if (!CLASSTYPE_USE_TEMPLATE (friend_type)
9067 && hidden_name_p (TYPE_NAME (friend_type)))
9071 where C hasn't been declared yet. Let's lookup name
9072 from namespace scope directly, bypassing any name that
9073 come from dependent base class. */
9074 tree ns = decl_namespace_context (TYPE_MAIN_DECL (friend_type));
9076 /* The call to xref_tag_from_type does injection for friend
9078 push_nested_namespace (ns);
9080 xref_tag_from_type (friend_type, NULL_TREE,
9081 /*tag_scope=*/ts_current);
9082 pop_nested_namespace (ns);
9084 else if (uses_template_parms (friend_type))
9085 /* friend class C<T>; */
9086 friend_type = tsubst (friend_type, args,
9087 tf_warning_or_error, NULL_TREE);
9092 where C is already declared or
9094 friend class C<int>;
9096 We don't have to do anything in these cases. */
9098 if (adjust_processing_template_decl)
9099 /* Trick make_friend_class into realizing that the friend
9100 we're adding is a template, not an ordinary class. It's
9101 important that we use make_friend_class since it will
9102 perform some error-checking and output cross-reference
9104 ++processing_template_decl;
9106 if (friend_type != error_mark_node)
9107 make_friend_class (type, friend_type, /*complain=*/false);
9109 if (adjust_processing_template_decl)
9110 --processing_template_decl;
9114 /* Build new DECL_FRIENDLIST. */
9117 /* The file and line for this declaration, to
9118 assist in error message reporting. Since we
9119 called push_tinst_level above, we don't need to
9121 input_location = DECL_SOURCE_LOCATION (t);
9123 if (TREE_CODE (t) == TEMPLATE_DECL)
9125 ++processing_template_decl;
9126 push_deferring_access_checks (dk_no_check);
9129 r = tsubst_friend_function (t, args);
9130 add_friend (type, r, /*complain=*/false);
9131 if (TREE_CODE (t) == TEMPLATE_DECL)
9133 pop_deferring_access_checks ();
9134 --processing_template_decl;
9140 if (CLASSTYPE_LAMBDA_EXPR (type))
9142 tree decl = lambda_function (type);
9145 tree lambda = CLASSTYPE_LAMBDA_EXPR (type);
9146 if (LAMBDA_EXPR_DEDUCE_RETURN_TYPE_P (lambda))
9148 apply_lambda_return_type (lambda, void_type_node);
9149 LAMBDA_EXPR_RETURN_TYPE (lambda) = NULL_TREE;
9151 instantiate_decl (decl, false, false);
9152 maybe_add_lambda_conv_op (type);
9155 gcc_assert (errorcount);
9158 /* Set the file and line number information to whatever is given for
9159 the class itself. This puts error messages involving generated
9160 implicit functions at a predictable point, and the same point
9161 that would be used for non-template classes. */
9162 input_location = DECL_SOURCE_LOCATION (typedecl);
9164 unreverse_member_declarations (type);
9165 finish_struct_1 (type);
9166 TYPE_BEING_DEFINED (type) = 0;
9168 /* We don't instantiate default arguments for member functions. 14.7.1:
9170 The implicit instantiation of a class template specialization causes
9171 the implicit instantiation of the declarations, but not of the
9172 definitions or default arguments, of the class member functions,
9173 member classes, static data members and member templates.... */
9175 /* Some typedefs referenced from within the template code need to be access
9176 checked at template instantiation time, i.e now. These types were
9177 added to the template at parsing time. Let's get those and perform
9178 the access checks then. */
9179 perform_typedefs_access_check (pattern, args);
9180 perform_deferred_access_checks ();
9181 pop_nested_class ();
9182 maximum_field_alignment = saved_maximum_field_alignment;
9183 pop_from_top_level ();
9184 pop_deferring_access_checks ();
9187 /* The vtable for a template class can be emitted in any translation
9188 unit in which the class is instantiated. When there is no key
9189 method, however, finish_struct_1 will already have added TYPE to
9190 the keyed_classes list. */
9191 if (TYPE_CONTAINS_VPTR_P (type) && CLASSTYPE_KEY_METHOD (type))
9192 keyed_classes = tree_cons (NULL_TREE, type, keyed_classes);
9197 /* Wrapper for instantiate_class_template_1. */
9200 instantiate_class_template (tree type)
9203 timevar_push (TV_TEMPLATE_INST);
9204 ret = instantiate_class_template_1 (type);
9205 timevar_pop (TV_TEMPLATE_INST);
9210 tsubst_template_arg (tree t, tree args, tsubst_flags_t complain, tree in_decl)
9216 else if (TYPE_P (t))
9217 r = tsubst (t, args, complain, in_decl);
9220 if (!(complain & tf_warning))
9221 ++c_inhibit_evaluation_warnings;
9222 r = tsubst_expr (t, args, complain, in_decl,
9223 /*integral_constant_expression_p=*/true);
9224 if (!(complain & tf_warning))
9225 --c_inhibit_evaluation_warnings;
9226 /* Preserve the raw-reference nature of T. */
9227 if (TREE_TYPE (t) && TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE
9228 && REFERENCE_REF_P (r))
9229 r = TREE_OPERAND (r, 0);
9234 /* Given a function parameter pack TMPL_PARM and some function parameters
9235 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
9236 and set *SPEC_P to point at the next point in the list. */
9239 extract_fnparm_pack (tree tmpl_parm, tree *spec_p)
9241 /* Collect all of the extra "packed" parameters into an
9245 tree argpack = make_node (NONTYPE_ARGUMENT_PACK);
9246 tree argtypepack = cxx_make_type (TYPE_ARGUMENT_PACK);
9247 tree spec_parm = *spec_p;
9250 for (len = 0; spec_parm; ++len, spec_parm = TREE_CHAIN (spec_parm))
9252 && !function_parameter_expanded_from_pack_p (spec_parm, tmpl_parm))
9255 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
9256 parmvec = make_tree_vec (len);
9257 parmtypevec = make_tree_vec (len);
9258 spec_parm = *spec_p;
9259 for (i = 0; i < len; i++, spec_parm = DECL_CHAIN (spec_parm))
9261 TREE_VEC_ELT (parmvec, i) = spec_parm;
9262 TREE_VEC_ELT (parmtypevec, i) = TREE_TYPE (spec_parm);
9265 /* Build the argument packs. */
9266 SET_ARGUMENT_PACK_ARGS (argpack, parmvec);
9267 SET_ARGUMENT_PACK_ARGS (argtypepack, parmtypevec);
9268 TREE_TYPE (argpack) = argtypepack;
9269 *spec_p = spec_parm;
9274 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
9275 NONTYPE_ARGUMENT_PACK. */
9278 make_fnparm_pack (tree spec_parm)
9280 return extract_fnparm_pack (NULL_TREE, &spec_parm);
9283 /* Substitute ARGS into T, which is an pack expansion
9284 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
9285 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
9286 (if only a partial substitution could be performed) or
9287 ERROR_MARK_NODE if there was an error. */
9289 tsubst_pack_expansion (tree t, tree args, tsubst_flags_t complain,
9293 tree pack, packs = NULL_TREE;
9294 bool unsubstituted_packs = false;
9295 bool real_packs = false;
9296 int missing_level = 0;
9299 htab_t saved_local_specializations = NULL;
9300 bool need_local_specializations = false;
9303 gcc_assert (PACK_EXPANSION_P (t));
9304 pattern = PACK_EXPANSION_PATTERN (t);
9306 /* Add in any args remembered from an earlier partial instantiation. */
9307 args = add_to_template_args (PACK_EXPANSION_EXTRA_ARGS (t), args);
9309 levels = TMPL_ARGS_DEPTH (args);
9311 /* Determine the argument packs that will instantiate the parameter
9312 packs used in the expansion expression. While we're at it,
9313 compute the number of arguments to be expanded and make sure it
9315 for (pack = PACK_EXPANSION_PARAMETER_PACKS (t); pack;
9316 pack = TREE_CHAIN (pack))
9318 tree parm_pack = TREE_VALUE (pack);
9319 tree arg_pack = NULL_TREE;
9320 tree orig_arg = NULL_TREE;
9323 if (TREE_CODE (parm_pack) == BASES)
9325 if (BASES_DIRECT (parm_pack))
9326 return calculate_direct_bases (tsubst_expr (BASES_TYPE (parm_pack),
9327 args, complain, in_decl, false));
9329 return calculate_bases (tsubst_expr (BASES_TYPE (parm_pack),
9330 args, complain, in_decl, false));
9332 if (TREE_CODE (parm_pack) == PARM_DECL)
9334 if (at_function_scope_p ())
9335 arg_pack = retrieve_local_specialization (parm_pack);
9338 /* We can't rely on local_specializations for a parameter
9339 name used later in a function declaration (such as in a
9340 late-specified return type). Even if it exists, it might
9341 have the wrong value for a recursive call. Just make a
9342 dummy decl, since it's only used for its type. */
9343 arg_pack = tsubst_decl (parm_pack, args, complain);
9344 if (arg_pack && FUNCTION_PARAMETER_PACK_P (arg_pack))
9345 /* Partial instantiation of the parm_pack, we can't build
9346 up an argument pack yet. */
9347 arg_pack = NULL_TREE;
9349 arg_pack = make_fnparm_pack (arg_pack);
9350 need_local_specializations = true;
9356 template_parm_level_and_index (parm_pack, &level, &idx);
9358 if (level <= levels)
9359 arg_pack = TMPL_ARG (args, level, idx);
9362 orig_arg = arg_pack;
9363 if (arg_pack && TREE_CODE (arg_pack) == ARGUMENT_PACK_SELECT)
9364 arg_pack = ARGUMENT_PACK_SELECT_FROM_PACK (arg_pack);
9366 if (arg_pack && !ARGUMENT_PACK_P (arg_pack))
9367 /* This can only happen if we forget to expand an argument
9368 pack somewhere else. Just return an error, silently. */
9370 result = make_tree_vec (1);
9371 TREE_VEC_ELT (result, 0) = error_mark_node;
9375 if (arg_from_parm_pack_p (arg_pack, parm_pack))
9376 /* The argument pack that the parameter maps to is just an
9377 expansion of the parameter itself, such as one would find
9378 in the implicit typedef of a class inside the class itself.
9379 Consider this parameter "unsubstituted", so that we will
9380 maintain the outer pack expansion. */
9381 arg_pack = NULL_TREE;
9386 TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack));
9388 /* Don't bother trying to do a partial substitution with
9389 incomplete packs; we'll try again after deduction. */
9390 if (ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
9395 else if (len != my_len)
9397 if (!(complain & tf_error))
9398 /* Fail quietly. */;
9399 else if (TREE_CODE (t) == TYPE_PACK_EXPANSION)
9400 error ("mismatched argument pack lengths while expanding "
9404 error ("mismatched argument pack lengths while expanding "
9407 return error_mark_node;
9410 if (TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack)) == 1
9411 && PACK_EXPANSION_P (TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack),
9413 /* This isn't a real argument pack yet. */;
9417 /* Keep track of the parameter packs and their corresponding
9419 packs = tree_cons (parm_pack, arg_pack, packs);
9420 TREE_TYPE (packs) = orig_arg;
9424 /* We can't substitute for this parameter pack. We use a flag as
9425 well as the missing_level counter because function parameter
9426 packs don't have a level. */
9427 unsubstituted_packs = true;
9428 if (!missing_level || missing_level > level)
9429 missing_level = level;
9433 /* We cannot expand this expansion expression, because we don't have
9434 all of the argument packs we need. */
9435 if (unsubstituted_packs)
9439 /* We got some full packs, but we can't substitute them in until we
9440 have values for all the packs. So remember these until then. */
9443 t = make_pack_expansion (pattern);
9445 /* The call to add_to_template_args above assumes no overlap
9446 between saved args and new args, so prune away any fake
9447 args, i.e. those that satisfied arg_from_parm_pack_p above. */
9448 if (missing_level && levels >= missing_level)
9450 gcc_assert (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args)
9451 && missing_level > 1);
9452 TREE_VEC_LENGTH (args) = missing_level - 1;
9453 save_args = copy_node (args);
9454 TREE_VEC_LENGTH (args) = levels;
9459 PACK_EXPANSION_EXTRA_ARGS (t) = save_args;
9463 /* There were no real arguments, we're just replacing a parameter
9464 pack with another version of itself. Substitute into the
9465 pattern and return a PACK_EXPANSION_*. The caller will need to
9467 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
9468 t = tsubst_expr (pattern, args, complain, in_decl,
9469 /*integral_constant_expression_p=*/false);
9471 t = tsubst (pattern, args, complain, in_decl);
9472 t = make_pack_expansion (t);
9477 /* We could not find any argument packs that work. */
9479 return error_mark_node;
9481 if (need_local_specializations)
9483 /* We're in a late-specified return type, so create our own local
9484 specializations table; the current table is either NULL or (in the
9485 case of recursive unification) might have bindings that we don't
9486 want to use or alter. */
9487 saved_local_specializations = local_specializations;
9488 local_specializations = htab_create (37,
9489 hash_local_specialization,
9490 eq_local_specializations,
9494 /* For each argument in each argument pack, substitute into the
9496 result = make_tree_vec (len);
9497 for (i = 0; i < len; ++i)
9499 /* For parameter pack, change the substitution of the parameter
9500 pack to the ith argument in its argument pack, then expand
9502 for (pack = packs; pack; pack = TREE_CHAIN (pack))
9504 tree parm = TREE_PURPOSE (pack);
9507 /* Select the Ith argument from the pack. */
9508 if (TREE_CODE (parm) == PARM_DECL)
9512 arg = make_node (ARGUMENT_PACK_SELECT);
9513 ARGUMENT_PACK_SELECT_FROM_PACK (arg) = TREE_VALUE (pack);
9515 register_local_specialization (arg, parm);
9518 arg = retrieve_local_specialization (parm);
9523 template_parm_level_and_index (parm, &level, &idx);
9527 arg = make_node (ARGUMENT_PACK_SELECT);
9528 ARGUMENT_PACK_SELECT_FROM_PACK (arg) = TREE_VALUE (pack);
9529 /* Update the corresponding argument. */
9530 TMPL_ARG (args, level, idx) = arg;
9533 /* Re-use the ARGUMENT_PACK_SELECT. */
9534 arg = TMPL_ARG (args, level, idx);
9536 ARGUMENT_PACK_SELECT_INDEX (arg) = i;
9539 /* Substitute into the PATTERN with the altered arguments. */
9540 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
9541 TREE_VEC_ELT (result, i) =
9542 tsubst_expr (pattern, args, complain, in_decl,
9543 /*integral_constant_expression_p=*/false);
9545 TREE_VEC_ELT (result, i) = tsubst (pattern, args, complain, in_decl);
9547 if (TREE_VEC_ELT (result, i) == error_mark_node)
9549 result = error_mark_node;
9554 /* Update ARGS to restore the substitution from parameter packs to
9555 their argument packs. */
9556 for (pack = packs; pack; pack = TREE_CHAIN (pack))
9558 tree parm = TREE_PURPOSE (pack);
9560 if (TREE_CODE (parm) == PARM_DECL)
9561 register_local_specialization (TREE_TYPE (pack), parm);
9565 template_parm_level_and_index (parm, &level, &idx);
9567 /* Update the corresponding argument. */
9568 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
9569 TREE_VEC_ELT (TREE_VEC_ELT (args, level -1 ), idx) =
9572 TREE_VEC_ELT (args, idx) = TREE_TYPE (pack);
9576 if (saved_local_specializations)
9578 htab_delete (local_specializations);
9579 local_specializations = saved_local_specializations;
9585 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
9586 TMPL. We do this using DECL_PARM_INDEX, which should work even with
9587 parameter packs; all parms generated from a function parameter pack will
9588 have the same DECL_PARM_INDEX. */
9591 get_pattern_parm (tree parm, tree tmpl)
9593 tree pattern = DECL_TEMPLATE_RESULT (tmpl);
9596 if (DECL_ARTIFICIAL (parm))
9598 for (patparm = DECL_ARGUMENTS (pattern);
9599 patparm; patparm = DECL_CHAIN (patparm))
9600 if (DECL_ARTIFICIAL (patparm)
9601 && DECL_NAME (parm) == DECL_NAME (patparm))
9606 patparm = FUNCTION_FIRST_USER_PARM (DECL_TEMPLATE_RESULT (tmpl));
9607 patparm = chain_index (DECL_PARM_INDEX (parm)-1, patparm);
9608 gcc_assert (DECL_PARM_INDEX (patparm)
9609 == DECL_PARM_INDEX (parm));
9615 /* Substitute ARGS into the vector or list of template arguments T. */
9618 tsubst_template_args (tree t, tree args, tsubst_flags_t complain, tree in_decl)
9621 int len, need_new = 0, i, expanded_len_adjust = 0, out;
9624 if (t == error_mark_node)
9625 return error_mark_node;
9627 len = TREE_VEC_LENGTH (t);
9628 elts = XALLOCAVEC (tree, len);
9630 for (i = 0; i < len; i++)
9632 tree orig_arg = TREE_VEC_ELT (t, i);
9635 if (TREE_CODE (orig_arg) == TREE_VEC)
9636 new_arg = tsubst_template_args (orig_arg, args, complain, in_decl);
9637 else if (PACK_EXPANSION_P (orig_arg))
9639 /* Substitute into an expansion expression. */
9640 new_arg = tsubst_pack_expansion (orig_arg, args, complain, in_decl);
9642 if (TREE_CODE (new_arg) == TREE_VEC)
9643 /* Add to the expanded length adjustment the number of
9644 expanded arguments. We subtract one from this
9645 measurement, because the argument pack expression
9646 itself is already counted as 1 in
9647 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
9648 the argument pack is empty. */
9649 expanded_len_adjust += TREE_VEC_LENGTH (new_arg) - 1;
9651 else if (ARGUMENT_PACK_P (orig_arg))
9653 /* Substitute into each of the arguments. */
9654 new_arg = TYPE_P (orig_arg)
9655 ? cxx_make_type (TREE_CODE (orig_arg))
9656 : make_node (TREE_CODE (orig_arg));
9658 SET_ARGUMENT_PACK_ARGS (
9660 tsubst_template_args (ARGUMENT_PACK_ARGS (orig_arg),
9661 args, complain, in_decl));
9663 if (ARGUMENT_PACK_ARGS (new_arg) == error_mark_node)
9664 new_arg = error_mark_node;
9666 if (TREE_CODE (new_arg) == NONTYPE_ARGUMENT_PACK) {
9667 TREE_TYPE (new_arg) = tsubst (TREE_TYPE (orig_arg), args,
9669 TREE_CONSTANT (new_arg) = TREE_CONSTANT (orig_arg);
9671 if (TREE_TYPE (new_arg) == error_mark_node)
9672 new_arg = error_mark_node;
9676 new_arg = tsubst_template_arg (orig_arg, args, complain, in_decl);
9678 if (new_arg == error_mark_node)
9679 return error_mark_node;
9682 if (new_arg != orig_arg)
9689 /* Make space for the expanded arguments coming from template
9691 t = make_tree_vec (len + expanded_len_adjust);
9692 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
9693 arguments for a member template.
9694 In that case each TREE_VEC in ORIG_T represents a level of template
9695 arguments, and ORIG_T won't carry any non defaulted argument count.
9696 It will rather be the nested TREE_VECs that will carry one.
9697 In other words, ORIG_T carries a non defaulted argument count only
9698 if it doesn't contain any nested TREE_VEC. */
9699 if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t))
9701 int count = GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t);
9702 count += expanded_len_adjust;
9703 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (t, count);
9705 for (i = 0, out = 0; i < len; i++)
9707 if ((PACK_EXPANSION_P (TREE_VEC_ELT (orig_t, i))
9708 || ARGUMENT_PACK_P (TREE_VEC_ELT (orig_t, i)))
9709 && TREE_CODE (elts[i]) == TREE_VEC)
9713 /* Now expand the template argument pack "in place". */
9714 for (idx = 0; idx < TREE_VEC_LENGTH (elts[i]); idx++, out++)
9715 TREE_VEC_ELT (t, out) = TREE_VEC_ELT (elts[i], idx);
9719 TREE_VEC_ELT (t, out) = elts[i];
9727 /* Return the result of substituting ARGS into the template parameters
9728 given by PARMS. If there are m levels of ARGS and m + n levels of
9729 PARMS, then the result will contain n levels of PARMS. For
9730 example, if PARMS is `template <class T> template <class U>
9731 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
9732 result will be `template <int*, double, class V>'. */
9735 tsubst_template_parms (tree parms, tree args, tsubst_flags_t complain)
9740 /* When substituting into a template, we must set
9741 PROCESSING_TEMPLATE_DECL as the template parameters may be
9742 dependent if they are based on one-another, and the dependency
9743 predicates are short-circuit outside of templates. */
9744 ++processing_template_decl;
9746 for (new_parms = &r;
9747 TMPL_PARMS_DEPTH (parms) > TMPL_ARGS_DEPTH (args);
9748 new_parms = &(TREE_CHAIN (*new_parms)),
9749 parms = TREE_CHAIN (parms))
9752 make_tree_vec (TREE_VEC_LENGTH (TREE_VALUE (parms)));
9755 for (i = 0; i < TREE_VEC_LENGTH (new_vec); ++i)
9759 if (parms == error_mark_node)
9762 tuple = TREE_VEC_ELT (TREE_VALUE (parms), i);
9764 if (tuple == error_mark_node)
9767 TREE_VEC_ELT (new_vec, i) =
9768 tsubst_template_parm (tuple, args, complain);
9772 tree_cons (size_int (TMPL_PARMS_DEPTH (parms)
9773 - TMPL_ARGS_DEPTH (args)),
9774 new_vec, NULL_TREE);
9777 --processing_template_decl;
9782 /* Return the result of substituting ARGS into one template parameter
9783 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
9784 parameter and which TREE_PURPOSE is the default argument of the
9785 template parameter. */
9788 tsubst_template_parm (tree t, tree args, tsubst_flags_t complain)
9790 tree default_value, parm_decl;
9792 if (args == NULL_TREE
9794 || t == error_mark_node)
9797 gcc_assert (TREE_CODE (t) == TREE_LIST);
9799 default_value = TREE_PURPOSE (t);
9800 parm_decl = TREE_VALUE (t);
9802 parm_decl = tsubst (parm_decl, args, complain, NULL_TREE);
9803 if (TREE_CODE (parm_decl) == PARM_DECL
9804 && invalid_nontype_parm_type_p (TREE_TYPE (parm_decl), complain))
9805 parm_decl = error_mark_node;
9806 default_value = tsubst_template_arg (default_value, args,
9807 complain, NULL_TREE);
9809 return build_tree_list (default_value, parm_decl);
9812 /* Substitute the ARGS into the indicated aggregate (or enumeration)
9813 type T. If T is not an aggregate or enumeration type, it is
9814 handled as if by tsubst. IN_DECL is as for tsubst. If
9815 ENTERING_SCOPE is nonzero, T is the context for a template which
9816 we are presently tsubst'ing. Return the substituted value. */
9819 tsubst_aggr_type (tree t,
9821 tsubst_flags_t complain,
9828 switch (TREE_CODE (t))
9831 if (TYPE_PTRMEMFUNC_P (t))
9832 return tsubst (TYPE_PTRMEMFUNC_FN_TYPE (t), args, complain, in_decl);
9834 /* Else fall through. */
9837 if (TYPE_TEMPLATE_INFO (t) && uses_template_parms (t))
9842 int saved_unevaluated_operand;
9843 int saved_inhibit_evaluation_warnings;
9845 /* In "sizeof(X<I>)" we need to evaluate "I". */
9846 saved_unevaluated_operand = cp_unevaluated_operand;
9847 cp_unevaluated_operand = 0;
9848 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
9849 c_inhibit_evaluation_warnings = 0;
9851 /* First, determine the context for the type we are looking
9853 context = TYPE_CONTEXT (t);
9854 if (context && TYPE_P (context))
9856 context = tsubst_aggr_type (context, args, complain,
9857 in_decl, /*entering_scope=*/1);
9858 /* If context is a nested class inside a class template,
9859 it may still need to be instantiated (c++/33959). */
9860 context = complete_type (context);
9863 /* Then, figure out what arguments are appropriate for the
9864 type we are trying to find. For example, given:
9866 template <class T> struct S;
9867 template <class T, class U> void f(T, U) { S<U> su; }
9869 and supposing that we are instantiating f<int, double>,
9870 then our ARGS will be {int, double}, but, when looking up
9871 S we only want {double}. */
9872 argvec = tsubst_template_args (TYPE_TI_ARGS (t), args,
9874 if (argvec == error_mark_node)
9875 r = error_mark_node;
9878 r = lookup_template_class (t, argvec, in_decl, context,
9879 entering_scope, complain);
9880 r = cp_build_qualified_type_real (r, cp_type_quals (t), complain);
9883 cp_unevaluated_operand = saved_unevaluated_operand;
9884 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
9889 /* This is not a template type, so there's nothing to do. */
9893 return tsubst (t, args, complain, in_decl);
9897 /* Substitute into the default argument ARG (a default argument for
9898 FN), which has the indicated TYPE. */
9901 tsubst_default_argument (tree fn, tree type, tree arg)
9903 tree saved_class_ptr = NULL_TREE;
9904 tree saved_class_ref = NULL_TREE;
9906 /* This can happen in invalid code. */
9907 if (TREE_CODE (arg) == DEFAULT_ARG)
9910 /* This default argument came from a template. Instantiate the
9911 default argument here, not in tsubst. In the case of
9920 we must be careful to do name lookup in the scope of S<T>,
9921 rather than in the current class. */
9922 push_access_scope (fn);
9923 /* The "this" pointer is not valid in a default argument. */
9926 saved_class_ptr = current_class_ptr;
9927 cp_function_chain->x_current_class_ptr = NULL_TREE;
9928 saved_class_ref = current_class_ref;
9929 cp_function_chain->x_current_class_ref = NULL_TREE;
9932 push_deferring_access_checks(dk_no_deferred);
9933 /* The default argument expression may cause implicitly defined
9934 member functions to be synthesized, which will result in garbage
9935 collection. We must treat this situation as if we were within
9936 the body of function so as to avoid collecting live data on the
9939 arg = tsubst_expr (arg, DECL_TI_ARGS (fn),
9940 tf_warning_or_error, NULL_TREE,
9941 /*integral_constant_expression_p=*/false);
9943 pop_deferring_access_checks();
9945 /* Restore the "this" pointer. */
9948 cp_function_chain->x_current_class_ptr = saved_class_ptr;
9949 cp_function_chain->x_current_class_ref = saved_class_ref;
9952 /* Make sure the default argument is reasonable. */
9953 arg = check_default_argument (type, arg);
9955 pop_access_scope (fn);
9960 /* Substitute into all the default arguments for FN. */
9963 tsubst_default_arguments (tree fn)
9968 tmpl_args = DECL_TI_ARGS (fn);
9970 /* If this function is not yet instantiated, we certainly don't need
9971 its default arguments. */
9972 if (uses_template_parms (tmpl_args))
9974 /* Don't do this again for clones. */
9975 if (DECL_CLONED_FUNCTION_P (fn))
9978 for (arg = TYPE_ARG_TYPES (TREE_TYPE (fn));
9980 arg = TREE_CHAIN (arg))
9981 if (TREE_PURPOSE (arg))
9982 TREE_PURPOSE (arg) = tsubst_default_argument (fn,
9984 TREE_PURPOSE (arg));
9987 /* Substitute the ARGS into the T, which is a _DECL. Return the
9988 result of the substitution. Issue error and warning messages under
9989 control of COMPLAIN. */
9992 tsubst_decl (tree t, tree args, tsubst_flags_t complain)
9994 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
9995 location_t saved_loc;
10000 /* Set the filename and linenumber to improve error-reporting. */
10001 saved_loc = input_location;
10002 input_location = DECL_SOURCE_LOCATION (t);
10004 switch (TREE_CODE (t))
10006 case TEMPLATE_DECL:
10008 /* We can get here when processing a member function template,
10009 member class template, or template template parameter. */
10010 tree decl = DECL_TEMPLATE_RESULT (t);
10015 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
10017 /* Template template parameter is treated here. */
10018 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10019 if (new_type == error_mark_node)
10020 RETURN (error_mark_node);
10023 DECL_CHAIN (r) = NULL_TREE;
10024 TREE_TYPE (r) = new_type;
10025 DECL_TEMPLATE_RESULT (r)
10026 = build_decl (DECL_SOURCE_LOCATION (decl),
10027 TYPE_DECL, DECL_NAME (decl), new_type);
10028 DECL_TEMPLATE_PARMS (r)
10029 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
10031 TYPE_NAME (new_type) = r;
10035 /* We might already have an instance of this template.
10036 The ARGS are for the surrounding class type, so the
10037 full args contain the tsubst'd args for the context,
10038 plus the innermost args from the template decl. */
10039 tmpl_args = DECL_CLASS_TEMPLATE_P (t)
10040 ? CLASSTYPE_TI_ARGS (TREE_TYPE (t))
10041 : DECL_TI_ARGS (DECL_TEMPLATE_RESULT (t));
10042 /* Because this is a template, the arguments will still be
10043 dependent, even after substitution. If
10044 PROCESSING_TEMPLATE_DECL is not set, the dependency
10045 predicates will short-circuit. */
10046 ++processing_template_decl;
10047 full_args = tsubst_template_args (tmpl_args, args,
10048 complain, in_decl);
10049 --processing_template_decl;
10050 if (full_args == error_mark_node)
10051 RETURN (error_mark_node);
10053 /* If this is a default template template argument,
10054 tsubst might not have changed anything. */
10055 if (full_args == tmpl_args)
10058 hash = hash_tmpl_and_args (t, full_args);
10059 spec = retrieve_specialization (t, full_args, hash);
10060 if (spec != NULL_TREE)
10066 /* Make a new template decl. It will be similar to the
10067 original, but will record the current template arguments.
10068 We also create a new function declaration, which is just
10069 like the old one, but points to this new template, rather
10070 than the old one. */
10072 gcc_assert (DECL_LANG_SPECIFIC (r) != 0);
10073 DECL_CHAIN (r) = NULL_TREE;
10075 DECL_TEMPLATE_INFO (r) = build_template_info (t, args);
10077 if (TREE_CODE (decl) == TYPE_DECL
10078 && !TYPE_DECL_ALIAS_P (decl))
10081 ++processing_template_decl;
10082 new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10083 --processing_template_decl;
10084 if (new_type == error_mark_node)
10085 RETURN (error_mark_node);
10087 TREE_TYPE (r) = new_type;
10088 CLASSTYPE_TI_TEMPLATE (new_type) = r;
10089 DECL_TEMPLATE_RESULT (r) = TYPE_MAIN_DECL (new_type);
10090 DECL_TI_ARGS (r) = CLASSTYPE_TI_ARGS (new_type);
10091 DECL_CONTEXT (r) = TYPE_CONTEXT (new_type);
10096 ++processing_template_decl;
10097 new_decl = tsubst (decl, args, complain, in_decl);
10098 --processing_template_decl;
10099 if (new_decl == error_mark_node)
10100 RETURN (error_mark_node);
10102 DECL_TEMPLATE_RESULT (r) = new_decl;
10103 DECL_TI_TEMPLATE (new_decl) = r;
10104 TREE_TYPE (r) = TREE_TYPE (new_decl);
10105 DECL_TI_ARGS (r) = DECL_TI_ARGS (new_decl);
10106 DECL_CONTEXT (r) = DECL_CONTEXT (new_decl);
10109 SET_DECL_IMPLICIT_INSTANTIATION (r);
10110 DECL_TEMPLATE_INSTANTIATIONS (r) = NULL_TREE;
10111 DECL_TEMPLATE_SPECIALIZATIONS (r) = NULL_TREE;
10113 /* The template parameters for this new template are all the
10114 template parameters for the old template, except the
10115 outermost level of parameters. */
10116 DECL_TEMPLATE_PARMS (r)
10117 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
10120 if (PRIMARY_TEMPLATE_P (t))
10121 DECL_PRIMARY_TEMPLATE (r) = r;
10123 if (TREE_CODE (decl) != TYPE_DECL)
10124 /* Record this non-type partial instantiation. */
10125 register_specialization (r, t,
10126 DECL_TI_ARGS (DECL_TEMPLATE_RESULT (r)),
10131 case FUNCTION_DECL:
10134 tree argvec = NULL_TREE;
10142 /* Nobody should be tsubst'ing into non-template functions. */
10143 gcc_assert (DECL_TEMPLATE_INFO (t) != NULL_TREE);
10145 if (TREE_CODE (DECL_TI_TEMPLATE (t)) == TEMPLATE_DECL)
10150 /* If T is not dependent, just return it. We have to
10151 increment PROCESSING_TEMPLATE_DECL because
10152 value_dependent_expression_p assumes that nothing is
10153 dependent when PROCESSING_TEMPLATE_DECL is zero. */
10154 ++processing_template_decl;
10155 dependent_p = value_dependent_expression_p (t);
10156 --processing_template_decl;
10160 /* Calculate the most general template of which R is a
10161 specialization, and the complete set of arguments used to
10163 gen_tmpl = most_general_template (DECL_TI_TEMPLATE (t));
10164 argvec = tsubst_template_args (DECL_TI_ARGS
10165 (DECL_TEMPLATE_RESULT
10166 (DECL_TI_TEMPLATE (t))),
10167 args, complain, in_decl);
10168 if (argvec == error_mark_node)
10169 RETURN (error_mark_node);
10171 /* Check to see if we already have this specialization. */
10172 hash = hash_tmpl_and_args (gen_tmpl, argvec);
10173 spec = retrieve_specialization (gen_tmpl, argvec, hash);
10181 /* We can see more levels of arguments than parameters if
10182 there was a specialization of a member template, like
10185 template <class T> struct S { template <class U> void f(); }
10186 template <> template <class U> void S<int>::f(U);
10188 Here, we'll be substituting into the specialization,
10189 because that's where we can find the code we actually
10190 want to generate, but we'll have enough arguments for
10191 the most general template.
10193 We also deal with the peculiar case:
10195 template <class T> struct S {
10196 template <class U> friend void f();
10198 template <class U> void f() {}
10200 template void f<double>();
10202 Here, the ARGS for the instantiation of will be {int,
10203 double}. But, we only need as many ARGS as there are
10204 levels of template parameters in CODE_PATTERN. We are
10205 careful not to get fooled into reducing the ARGS in
10208 template <class T> struct S { template <class U> void f(U); }
10209 template <class T> template <> void S<T>::f(int) {}
10211 which we can spot because the pattern will be a
10212 specialization in this case. */
10213 args_depth = TMPL_ARGS_DEPTH (args);
10215 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (t)));
10216 if (args_depth > parms_depth
10217 && !DECL_TEMPLATE_SPECIALIZATION (t))
10218 args = get_innermost_template_args (args, parms_depth);
10222 /* This special case arises when we have something like this:
10224 template <class T> struct S {
10225 friend void f<int>(int, double);
10228 Here, the DECL_TI_TEMPLATE for the friend declaration
10229 will be an IDENTIFIER_NODE. We are being called from
10230 tsubst_friend_function, and we want only to create a
10231 new decl (R) with appropriate types so that we can call
10232 determine_specialization. */
10233 gen_tmpl = NULL_TREE;
10236 if (DECL_CLASS_SCOPE_P (t))
10238 if (DECL_NAME (t) == constructor_name (DECL_CONTEXT (t)))
10242 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args,
10243 complain, t, /*entering_scope=*/1);
10248 ctx = DECL_CONTEXT (t);
10250 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10251 if (type == error_mark_node)
10252 RETURN (error_mark_node);
10254 /* We do NOT check for matching decls pushed separately at this
10255 point, as they may not represent instantiations of this
10256 template, and in any case are considered separate under the
10259 DECL_USE_TEMPLATE (r) = 0;
10260 TREE_TYPE (r) = type;
10261 /* Clear out the mangled name and RTL for the instantiation. */
10262 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
10263 SET_DECL_RTL (r, NULL);
10264 /* Leave DECL_INITIAL set on deleted instantiations. */
10265 if (!DECL_DELETED_FN (r))
10266 DECL_INITIAL (r) = NULL_TREE;
10267 DECL_CONTEXT (r) = ctx;
10269 if (member && DECL_CONV_FN_P (r))
10270 /* Type-conversion operator. Reconstruct the name, in
10271 case it's the name of one of the template's parameters. */
10272 DECL_NAME (r) = mangle_conv_op_name_for_type (TREE_TYPE (type));
10274 DECL_ARGUMENTS (r) = tsubst (DECL_ARGUMENTS (t), args,
10276 DECL_RESULT (r) = NULL_TREE;
10278 TREE_STATIC (r) = 0;
10279 TREE_PUBLIC (r) = TREE_PUBLIC (t);
10280 DECL_EXTERNAL (r) = 1;
10281 /* If this is an instantiation of a function with internal
10282 linkage, we already know what object file linkage will be
10283 assigned to the instantiation. */
10284 DECL_INTERFACE_KNOWN (r) = !TREE_PUBLIC (r);
10285 DECL_DEFER_OUTPUT (r) = 0;
10286 DECL_CHAIN (r) = NULL_TREE;
10287 DECL_PENDING_INLINE_INFO (r) = 0;
10288 DECL_PENDING_INLINE_P (r) = 0;
10289 DECL_SAVED_TREE (r) = NULL_TREE;
10290 DECL_STRUCT_FUNCTION (r) = NULL;
10292 /* We'll re-clone as appropriate in instantiate_template. */
10293 DECL_CLONED_FUNCTION (r) = NULL_TREE;
10295 /* If we aren't complaining now, return on error before we register
10296 the specialization so that we'll complain eventually. */
10297 if ((complain & tf_error) == 0
10298 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
10299 && !grok_op_properties (r, /*complain=*/false))
10300 RETURN (error_mark_node);
10302 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
10303 this in the special friend case mentioned above where
10304 GEN_TMPL is NULL. */
10307 DECL_TEMPLATE_INFO (r)
10308 = build_template_info (gen_tmpl, argvec);
10309 SET_DECL_IMPLICIT_INSTANTIATION (r);
10310 register_specialization (r, gen_tmpl, argvec, false, hash);
10312 /* We're not supposed to instantiate default arguments
10313 until they are called, for a template. But, for a
10316 template <class T> void f ()
10317 { extern void g(int i = T()); }
10319 we should do the substitution when the template is
10320 instantiated. We handle the member function case in
10321 instantiate_class_template since the default arguments
10322 might refer to other members of the class. */
10324 && !PRIMARY_TEMPLATE_P (gen_tmpl)
10325 && !uses_template_parms (argvec))
10326 tsubst_default_arguments (r);
10329 DECL_TEMPLATE_INFO (r) = NULL_TREE;
10331 /* Copy the list of befriending classes. */
10332 for (friends = &DECL_BEFRIENDING_CLASSES (r);
10334 friends = &TREE_CHAIN (*friends))
10336 *friends = copy_node (*friends);
10337 TREE_VALUE (*friends) = tsubst (TREE_VALUE (*friends),
10342 if (DECL_CONSTRUCTOR_P (r) || DECL_DESTRUCTOR_P (r))
10344 maybe_retrofit_in_chrg (r);
10345 if (DECL_CONSTRUCTOR_P (r))
10346 grok_ctor_properties (ctx, r);
10347 /* If this is an instantiation of a member template, clone it.
10348 If it isn't, that'll be handled by
10349 clone_constructors_and_destructors. */
10350 if (PRIMARY_TEMPLATE_P (gen_tmpl))
10351 clone_function_decl (r, /*update_method_vec_p=*/0);
10353 else if ((complain & tf_error) != 0
10354 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
10355 && !grok_op_properties (r, /*complain=*/true))
10356 RETURN (error_mark_node);
10358 if (DECL_FRIEND_P (t) && DECL_FRIEND_CONTEXT (t))
10359 SET_DECL_FRIEND_CONTEXT (r,
10360 tsubst (DECL_FRIEND_CONTEXT (t),
10361 args, complain, in_decl));
10363 /* Possibly limit visibility based on template args. */
10364 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
10365 if (DECL_VISIBILITY_SPECIFIED (t))
10367 DECL_VISIBILITY_SPECIFIED (r) = 0;
10368 DECL_ATTRIBUTES (r)
10369 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
10371 determine_visibility (r);
10372 if (DECL_DEFAULTED_OUTSIDE_CLASS_P (r)
10373 && !processing_template_decl)
10374 defaulted_late_check (r);
10376 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
10377 args, complain, in_decl);
10383 tree type = NULL_TREE;
10385 tree expanded_types = NULL_TREE;
10386 tree prev_r = NULL_TREE;
10387 tree first_r = NULL_TREE;
10389 if (FUNCTION_PARAMETER_PACK_P (t))
10391 /* If there is a local specialization that isn't a
10392 parameter pack, it means that we're doing a "simple"
10393 substitution from inside tsubst_pack_expansion. Just
10394 return the local specialization (which will be a single
10396 tree spec = retrieve_local_specialization (t);
10398 && TREE_CODE (spec) == PARM_DECL
10399 && TREE_CODE (TREE_TYPE (spec)) != TYPE_PACK_EXPANSION)
10402 /* Expand the TYPE_PACK_EXPANSION that provides the types for
10403 the parameters in this function parameter pack. */
10404 expanded_types = tsubst_pack_expansion (TREE_TYPE (t), args,
10405 complain, in_decl);
10406 if (TREE_CODE (expanded_types) == TREE_VEC)
10408 len = TREE_VEC_LENGTH (expanded_types);
10410 /* Zero-length parameter packs are boring. Just substitute
10413 RETURN (tsubst (TREE_CHAIN (t), args, complain,
10418 /* All we did was update the type. Make a note of that. */
10419 type = expanded_types;
10420 expanded_types = NULL_TREE;
10424 /* Loop through all of the parameter's we'll build. When T is
10425 a function parameter pack, LEN is the number of expanded
10426 types in EXPANDED_TYPES; otherwise, LEN is 1. */
10428 for (i = 0; i < len; ++i)
10432 if (DECL_TEMPLATE_PARM_P (t))
10433 SET_DECL_TEMPLATE_PARM_P (r);
10435 if (expanded_types)
10436 /* We're on the Ith parameter of the function parameter
10439 /* An argument of a function parameter pack is not a parameter
10441 FUNCTION_PARAMETER_PACK_P (r) = false;
10443 /* Get the Ith type. */
10444 type = TREE_VEC_ELT (expanded_types, i);
10447 /* Rename the parameter to include the index. */
10449 make_ith_pack_parameter_name (DECL_NAME (r), i);
10452 /* We're dealing with a normal parameter. */
10453 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10455 type = type_decays_to (type);
10456 TREE_TYPE (r) = type;
10457 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
10459 if (DECL_INITIAL (r))
10461 if (TREE_CODE (DECL_INITIAL (r)) != TEMPLATE_PARM_INDEX)
10462 DECL_INITIAL (r) = TREE_TYPE (r);
10464 DECL_INITIAL (r) = tsubst (DECL_INITIAL (r), args,
10465 complain, in_decl);
10468 DECL_CONTEXT (r) = NULL_TREE;
10470 if (!DECL_TEMPLATE_PARM_P (r))
10471 DECL_ARG_TYPE (r) = type_passed_as (type);
10473 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
10474 args, complain, in_decl);
10476 /* Keep track of the first new parameter we
10477 generate. That's what will be returned to the
10482 /* Build a proper chain of parameters when substituting
10483 into a function parameter pack. */
10485 DECL_CHAIN (prev_r) = r;
10488 if (DECL_CHAIN (t))
10489 DECL_CHAIN (r) = tsubst (DECL_CHAIN (t), args,
10490 complain, DECL_CHAIN (t));
10492 /* FIRST_R contains the start of the chain we've built. */
10502 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10503 if (type == error_mark_node)
10504 RETURN (error_mark_node);
10505 TREE_TYPE (r) = type;
10506 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
10508 if (DECL_C_BIT_FIELD (r))
10509 /* For bit-fields, DECL_INITIAL gives the number of bits. For
10510 non-bit-fields DECL_INITIAL is a non-static data member
10511 initializer, which gets deferred instantiation. */
10513 = tsubst_expr (DECL_INITIAL (t), args,
10515 /*integral_constant_expression_p=*/true);
10516 else if (DECL_INITIAL (t))
10518 /* Set up DECL_TEMPLATE_INFO so that we can get at the
10519 NSDMI in perform_member_init. Still set DECL_INITIAL
10520 so that we know there is one. */
10521 DECL_INITIAL (r) = void_zero_node;
10522 gcc_assert (DECL_LANG_SPECIFIC (r) == NULL);
10523 retrofit_lang_decl (r);
10524 DECL_TEMPLATE_INFO (r) = build_template_info (t, args);
10526 /* We don't have to set DECL_CONTEXT here; it is set by
10527 finish_member_declaration. */
10528 DECL_CHAIN (r) = NULL_TREE;
10529 if (VOID_TYPE_P (type))
10530 error ("instantiation of %q+D as type %qT", r, type);
10532 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
10533 args, complain, in_decl);
10538 /* We reach here only for member using decls. */
10539 if (DECL_DEPENDENT_P (t))
10541 r = do_class_using_decl
10542 (tsubst_copy (USING_DECL_SCOPE (t), args, complain, in_decl),
10543 tsubst_copy (DECL_NAME (t), args, complain, in_decl));
10545 r = error_mark_node;
10548 TREE_PROTECTED (r) = TREE_PROTECTED (t);
10549 TREE_PRIVATE (r) = TREE_PRIVATE (t);
10555 DECL_CHAIN (r) = NULL_TREE;
10562 tree argvec = NULL_TREE;
10563 tree gen_tmpl = NULL_TREE;
10565 tree tmpl = NULL_TREE;
10567 tree type = NULL_TREE;
10570 if (TREE_CODE (t) == TYPE_DECL
10571 && t == TYPE_MAIN_DECL (TREE_TYPE (t)))
10573 /* If this is the canonical decl, we don't have to
10574 mess with instantiations, and often we can't (for
10575 typename, template type parms and such). Note that
10576 TYPE_NAME is not correct for the above test if
10577 we've copied the type for a typedef. */
10578 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10579 if (type == error_mark_node)
10580 RETURN (error_mark_node);
10581 r = TYPE_NAME (type);
10585 /* Check to see if we already have the specialization we
10588 if (DECL_CLASS_SCOPE_P (t) || DECL_NAMESPACE_SCOPE_P (t))
10590 /* T is a static data member or namespace-scope entity.
10591 We have to substitute into namespace-scope variables
10592 (even though such entities are never templates) because
10595 template <class T> void f() { extern T t; }
10597 where the entity referenced is not known until
10598 instantiation time. */
10600 ctx = DECL_CONTEXT (t);
10601 if (DECL_CLASS_SCOPE_P (t))
10603 ctx = tsubst_aggr_type (ctx, args,
10605 in_decl, /*entering_scope=*/1);
10606 /* If CTX is unchanged, then T is in fact the
10607 specialization we want. That situation occurs when
10608 referencing a static data member within in its own
10609 class. We can use pointer equality, rather than
10610 same_type_p, because DECL_CONTEXT is always
10612 if (ctx == DECL_CONTEXT (t)
10613 && (TREE_CODE (t) != TYPE_DECL
10614 /* ... unless T is a member template; in which
10615 case our caller can be willing to create a
10616 specialization of that template represented
10618 || !(DECL_TI_TEMPLATE (t)
10619 && DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (t)))))
10625 tmpl = DECL_TI_TEMPLATE (t);
10626 gen_tmpl = most_general_template (tmpl);
10627 argvec = tsubst (DECL_TI_ARGS (t), args, complain, in_decl);
10628 hash = hash_tmpl_and_args (gen_tmpl, argvec);
10629 spec = retrieve_specialization (gen_tmpl, argvec, hash);
10634 /* A local variable. */
10636 /* Subsequent calls to pushdecl will fill this in. */
10638 spec = retrieve_local_specialization (t);
10640 /* If we already have the specialization we need, there is
10641 nothing more to do. */
10648 /* Create a new node for the specialization we need. */
10650 if (type == NULL_TREE)
10652 if (is_typedef_decl (t))
10653 type = DECL_ORIGINAL_TYPE (t);
10655 type = TREE_TYPE (t);
10656 if (TREE_CODE (t) == VAR_DECL
10657 && VAR_HAD_UNKNOWN_BOUND (t)
10658 && type != error_mark_node)
10659 type = strip_array_domain (type);
10660 type = tsubst (type, args, complain, in_decl);
10662 if (TREE_CODE (r) == VAR_DECL)
10664 /* Even if the original location is out of scope, the
10665 newly substituted one is not. */
10666 DECL_DEAD_FOR_LOCAL (r) = 0;
10667 DECL_INITIALIZED_P (r) = 0;
10668 DECL_TEMPLATE_INSTANTIATED (r) = 0;
10669 if (type == error_mark_node)
10670 RETURN (error_mark_node);
10671 if (TREE_CODE (type) == FUNCTION_TYPE)
10673 /* It may seem that this case cannot occur, since:
10678 declares a function, not a variable. However:
10681 template <typename T> void g() { T t; }
10682 template void g<f>();
10684 is an attempt to declare a variable with function
10686 error ("variable %qD has function type",
10687 /* R is not yet sufficiently initialized, so we
10688 just use its name. */
10690 RETURN (error_mark_node);
10692 type = complete_type (type);
10693 /* Wait until cp_finish_decl to set this again, to handle
10694 circular dependency (template/instantiate6.C). */
10695 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r) = 0;
10696 type = check_var_type (DECL_NAME (r), type);
10698 if (DECL_HAS_VALUE_EXPR_P (t))
10700 tree ve = DECL_VALUE_EXPR (t);
10701 ve = tsubst_expr (ve, args, complain, in_decl,
10702 /*constant_expression_p=*/false);
10703 if (REFERENCE_REF_P (ve))
10705 gcc_assert (TREE_CODE (type) == REFERENCE_TYPE);
10706 ve = TREE_OPERAND (ve, 0);
10708 SET_DECL_VALUE_EXPR (r, ve);
10711 else if (DECL_SELF_REFERENCE_P (t))
10712 SET_DECL_SELF_REFERENCE_P (r);
10713 TREE_TYPE (r) = type;
10714 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
10715 DECL_CONTEXT (r) = ctx;
10716 /* Clear out the mangled name and RTL for the instantiation. */
10717 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
10718 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
10719 SET_DECL_RTL (r, NULL);
10720 /* The initializer must not be expanded until it is required;
10721 see [temp.inst]. */
10722 DECL_INITIAL (r) = NULL_TREE;
10723 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
10724 SET_DECL_RTL (r, NULL);
10725 DECL_SIZE (r) = DECL_SIZE_UNIT (r) = 0;
10726 if (TREE_CODE (r) == VAR_DECL)
10728 /* Possibly limit visibility based on template args. */
10729 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
10730 if (DECL_VISIBILITY_SPECIFIED (t))
10732 DECL_VISIBILITY_SPECIFIED (r) = 0;
10733 DECL_ATTRIBUTES (r)
10734 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
10736 determine_visibility (r);
10741 /* A static data member declaration is always marked
10742 external when it is declared in-class, even if an
10743 initializer is present. We mimic the non-template
10744 processing here. */
10745 DECL_EXTERNAL (r) = 1;
10747 register_specialization (r, gen_tmpl, argvec, false, hash);
10748 DECL_TEMPLATE_INFO (r) = build_template_info (tmpl, argvec);
10749 SET_DECL_IMPLICIT_INSTANTIATION (r);
10751 else if (cp_unevaluated_operand)
10753 /* We're substituting this var in a decltype outside of its
10754 scope, such as for a lambda return type. Don't add it to
10755 local_specializations, do perform auto deduction. */
10756 tree auto_node = type_uses_auto (type);
10760 = tsubst_expr (DECL_INITIAL (t), args, complain, in_decl,
10761 /*constant_expression_p=*/false);
10762 init = resolve_nondeduced_context (init);
10763 TREE_TYPE (r) = type
10764 = do_auto_deduction (type, init, auto_node);
10768 register_local_specialization (r, t);
10770 DECL_CHAIN (r) = NULL_TREE;
10772 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r),
10774 args, complain, in_decl);
10776 /* Preserve a typedef that names a type. */
10777 if (is_typedef_decl (r))
10779 DECL_ORIGINAL_TYPE (r) = NULL_TREE;
10780 set_underlying_type (r);
10783 layout_decl (r, 0);
10788 gcc_unreachable ();
10793 /* Restore the file and line information. */
10794 input_location = saved_loc;
10799 /* Substitute into the ARG_TYPES of a function type. */
10802 tsubst_arg_types (tree arg_types,
10804 tsubst_flags_t complain,
10807 tree remaining_arg_types;
10808 tree type = NULL_TREE;
10810 tree expanded_args = NULL_TREE;
10813 if (!arg_types || arg_types == void_list_node)
10816 remaining_arg_types = tsubst_arg_types (TREE_CHAIN (arg_types),
10817 args, complain, in_decl);
10818 if (remaining_arg_types == error_mark_node)
10819 return error_mark_node;
10821 if (PACK_EXPANSION_P (TREE_VALUE (arg_types)))
10823 /* For a pack expansion, perform substitution on the
10824 entire expression. Later on, we'll handle the arguments
10826 expanded_args = tsubst_pack_expansion (TREE_VALUE (arg_types),
10827 args, complain, in_decl);
10829 if (TREE_CODE (expanded_args) == TREE_VEC)
10830 /* So that we'll spin through the parameters, one by one. */
10831 i = TREE_VEC_LENGTH (expanded_args);
10834 /* We only partially substituted into the parameter
10835 pack. Our type is TYPE_PACK_EXPANSION. */
10836 type = expanded_args;
10837 expanded_args = NULL_TREE;
10845 type = TREE_VEC_ELT (expanded_args, i);
10847 type = tsubst (TREE_VALUE (arg_types), args, complain, in_decl);
10849 if (type == error_mark_node)
10850 return error_mark_node;
10851 if (VOID_TYPE_P (type))
10853 if (complain & tf_error)
10855 error ("invalid parameter type %qT", type);
10857 error ("in declaration %q+D", in_decl);
10859 return error_mark_node;
10862 /* Do array-to-pointer, function-to-pointer conversion, and ignore
10863 top-level qualifiers as required. */
10864 type = cv_unqualified (type_decays_to (type));
10866 /* We do not substitute into default arguments here. The standard
10867 mandates that they be instantiated only when needed, which is
10868 done in build_over_call. */
10869 default_arg = TREE_PURPOSE (arg_types);
10871 if (default_arg && TREE_CODE (default_arg) == DEFAULT_ARG)
10873 /* We've instantiated a template before its default arguments
10874 have been parsed. This can happen for a nested template
10875 class, and is not an error unless we require the default
10876 argument in a call of this function. */
10877 remaining_arg_types =
10878 tree_cons (default_arg, type, remaining_arg_types);
10879 VEC_safe_push (tree, gc, DEFARG_INSTANTIATIONS (default_arg),
10880 remaining_arg_types);
10883 remaining_arg_types =
10884 hash_tree_cons (default_arg, type, remaining_arg_types);
10887 return remaining_arg_types;
10890 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
10891 *not* handle the exception-specification for FNTYPE, because the
10892 initial substitution of explicitly provided template parameters
10893 during argument deduction forbids substitution into the
10894 exception-specification:
10898 All references in the function type of the function template to the
10899 corresponding template parameters are replaced by the specified tem-
10900 plate argument values. If a substitution in a template parameter or
10901 in the function type of the function template results in an invalid
10902 type, type deduction fails. [Note: The equivalent substitution in
10903 exception specifications is done only when the function is instanti-
10904 ated, at which point a program is ill-formed if the substitution
10905 results in an invalid type.] */
10908 tsubst_function_type (tree t,
10910 tsubst_flags_t complain,
10917 /* The TYPE_CONTEXT is not used for function/method types. */
10918 gcc_assert (TYPE_CONTEXT (t) == NULL_TREE);
10920 /* Substitute the return type. */
10921 return_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10922 if (return_type == error_mark_node)
10923 return error_mark_node;
10924 /* The standard does not presently indicate that creation of a
10925 function type with an invalid return type is a deduction failure.
10926 However, that is clearly analogous to creating an array of "void"
10927 or a reference to a reference. This is core issue #486. */
10928 if (TREE_CODE (return_type) == ARRAY_TYPE
10929 || TREE_CODE (return_type) == FUNCTION_TYPE)
10931 if (complain & tf_error)
10933 if (TREE_CODE (return_type) == ARRAY_TYPE)
10934 error ("function returning an array");
10936 error ("function returning a function");
10938 return error_mark_node;
10941 /* Substitute the argument types. */
10942 arg_types = tsubst_arg_types (TYPE_ARG_TYPES (t), args,
10943 complain, in_decl);
10944 if (arg_types == error_mark_node)
10945 return error_mark_node;
10947 /* Construct a new type node and return it. */
10948 if (TREE_CODE (t) == FUNCTION_TYPE)
10950 fntype = build_function_type (return_type, arg_types);
10951 fntype = apply_memfn_quals (fntype, type_memfn_quals (t));
10955 tree r = TREE_TYPE (TREE_VALUE (arg_types));
10956 if (! MAYBE_CLASS_TYPE_P (r))
10960 Type deduction may fail for any of the following
10963 -- Attempting to create "pointer to member of T" when T
10964 is not a class type. */
10965 if (complain & tf_error)
10966 error ("creating pointer to member function of non-class type %qT",
10968 return error_mark_node;
10971 fntype = build_method_type_directly (r, return_type,
10972 TREE_CHAIN (arg_types));
10974 fntype = cp_build_type_attribute_variant (fntype, TYPE_ATTRIBUTES (t));
10979 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
10980 ARGS into that specification, and return the substituted
10981 specification. If there is no specification, return NULL_TREE. */
10984 tsubst_exception_specification (tree fntype,
10986 tsubst_flags_t complain,
10993 specs = TYPE_RAISES_EXCEPTIONS (fntype);
10994 new_specs = NULL_TREE;
10995 if (specs && TREE_PURPOSE (specs))
10997 /* A noexcept-specifier. */
10998 tree expr = TREE_PURPOSE (specs);
10999 if (expr == boolean_true_node || expr == boolean_false_node)
11003 /* Defer instantiation of noexcept-specifiers to avoid
11004 excessive instantiations (c++/49107). */
11005 new_specs = make_node (DEFERRED_NOEXCEPT);
11006 if (DEFERRED_NOEXCEPT_SPEC_P (specs))
11008 /* We already partially instantiated this member template,
11009 so combine the new args with the old. */
11010 DEFERRED_NOEXCEPT_PATTERN (new_specs)
11011 = DEFERRED_NOEXCEPT_PATTERN (expr);
11012 DEFERRED_NOEXCEPT_ARGS (new_specs)
11013 = add_to_template_args (DEFERRED_NOEXCEPT_ARGS (expr), args);
11017 DEFERRED_NOEXCEPT_PATTERN (new_specs) = expr;
11018 DEFERRED_NOEXCEPT_ARGS (new_specs) = args;
11022 new_specs = tsubst_copy_and_build
11023 (expr, args, complain, in_decl, /*function_p=*/false,
11024 /*integral_constant_expression_p=*/true);
11025 new_specs = build_noexcept_spec (new_specs, complain);
11029 if (! TREE_VALUE (specs))
11036 tree expanded_specs = NULL_TREE;
11038 if (PACK_EXPANSION_P (TREE_VALUE (specs)))
11040 /* Expand the pack expansion type. */
11041 expanded_specs = tsubst_pack_expansion (TREE_VALUE (specs),
11045 if (expanded_specs == error_mark_node)
11046 return error_mark_node;
11047 else if (TREE_CODE (expanded_specs) == TREE_VEC)
11048 len = TREE_VEC_LENGTH (expanded_specs);
11051 /* We're substituting into a member template, so
11052 we got a TYPE_PACK_EXPANSION back. Add that
11053 expansion and move on. */
11054 gcc_assert (TREE_CODE (expanded_specs)
11055 == TYPE_PACK_EXPANSION);
11056 new_specs = add_exception_specifier (new_specs,
11059 specs = TREE_CHAIN (specs);
11064 for (i = 0; i < len; ++i)
11066 if (expanded_specs)
11067 spec = TREE_VEC_ELT (expanded_specs, i);
11069 spec = tsubst (TREE_VALUE (specs), args, complain, in_decl);
11070 if (spec == error_mark_node)
11072 new_specs = add_exception_specifier (new_specs, spec,
11076 specs = TREE_CHAIN (specs);
11082 /* Take the tree structure T and replace template parameters used
11083 therein with the argument vector ARGS. IN_DECL is an associated
11084 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
11085 Issue error and warning messages under control of COMPLAIN. Note
11086 that we must be relatively non-tolerant of extensions here, in
11087 order to preserve conformance; if we allow substitutions that
11088 should not be allowed, we may allow argument deductions that should
11089 not succeed, and therefore report ambiguous overload situations
11090 where there are none. In theory, we could allow the substitution,
11091 but indicate that it should have failed, and allow our caller to
11092 make sure that the right thing happens, but we don't try to do this
11095 This function is used for dealing with types, decls and the like;
11096 for expressions, use tsubst_expr or tsubst_copy. */
11099 tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl)
11101 enum tree_code code;
11102 tree type, r = NULL_TREE;
11104 if (t == NULL_TREE || t == error_mark_node
11105 || t == integer_type_node
11106 || t == void_type_node
11107 || t == char_type_node
11108 || t == unknown_type_node
11109 || TREE_CODE (t) == NAMESPACE_DECL
11110 || TREE_CODE (t) == TRANSLATION_UNIT_DECL)
11114 return tsubst_decl (t, args, complain);
11116 if (args == NULL_TREE)
11119 code = TREE_CODE (t);
11121 if (code == IDENTIFIER_NODE)
11122 type = IDENTIFIER_TYPE_VALUE (t);
11124 type = TREE_TYPE (t);
11126 gcc_assert (type != unknown_type_node);
11128 /* Reuse typedefs. We need to do this to handle dependent attributes,
11129 such as attribute aligned. */
11131 && typedef_variant_p (t))
11133 tree decl = TYPE_NAME (t);
11135 if (TYPE_DECL_ALIAS_P (decl)
11136 && DECL_LANG_SPECIFIC (decl)
11137 && DECL_TEMPLATE_INFO (decl)
11138 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (decl)))
11140 /* DECL represents an alias template and we want to
11141 instantiate it. Let's substitute our arguments for the
11142 template parameters into the declaration and get the
11144 r = tsubst (decl, args, complain, decl);
11146 else if (DECL_CLASS_SCOPE_P (decl)
11147 && CLASSTYPE_TEMPLATE_INFO (DECL_CONTEXT (decl))
11148 && uses_template_parms (DECL_CONTEXT (decl)))
11150 tree tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
11151 tree gen_args = tsubst (DECL_TI_ARGS (decl), args, complain, in_decl);
11152 r = retrieve_specialization (tmpl, gen_args, 0);
11154 else if (DECL_FUNCTION_SCOPE_P (decl)
11155 && DECL_TEMPLATE_INFO (DECL_CONTEXT (decl))
11156 && uses_template_parms (DECL_TI_ARGS (DECL_CONTEXT (decl))))
11157 r = retrieve_local_specialization (decl);
11159 /* The typedef is from a non-template context. */
11165 r = cp_build_qualified_type_real
11166 (r, cp_type_quals (t) | cp_type_quals (r),
11167 complain | tf_ignore_bad_quals);
11170 /* Else we must be instantiating the typedef, so fall through. */
11174 && code != TYPENAME_TYPE
11175 && code != TEMPLATE_TYPE_PARM
11176 && code != IDENTIFIER_NODE
11177 && code != FUNCTION_TYPE
11178 && code != METHOD_TYPE)
11179 type = tsubst (type, args, complain, in_decl);
11180 if (type == error_mark_node)
11181 return error_mark_node;
11187 case ENUMERAL_TYPE:
11188 return tsubst_aggr_type (t, args, complain, in_decl,
11189 /*entering_scope=*/0);
11192 case IDENTIFIER_NODE:
11203 if (t == integer_type_node)
11206 if (TREE_CODE (TYPE_MIN_VALUE (t)) == INTEGER_CST
11207 && TREE_CODE (TYPE_MAX_VALUE (t)) == INTEGER_CST)
11211 tree max, omax = TREE_OPERAND (TYPE_MAX_VALUE (t), 0);
11213 max = tsubst_expr (omax, args, complain, in_decl,
11214 /*integral_constant_expression_p=*/false);
11216 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
11218 if (TREE_CODE (max) == NOP_EXPR
11219 && TREE_SIDE_EFFECTS (omax)
11220 && !TREE_TYPE (max))
11221 TREE_TYPE (max) = TREE_TYPE (TREE_OPERAND (max, 0));
11223 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
11224 with TREE_SIDE_EFFECTS that indicates this is not an integral
11225 constant expression. */
11226 if (processing_template_decl
11227 && TREE_SIDE_EFFECTS (omax) && TREE_CODE (omax) == NOP_EXPR)
11229 gcc_assert (TREE_CODE (max) == NOP_EXPR);
11230 TREE_SIDE_EFFECTS (max) = 1;
11233 return compute_array_index_type (NULL_TREE, max, complain);
11236 case TEMPLATE_TYPE_PARM:
11237 case TEMPLATE_TEMPLATE_PARM:
11238 case BOUND_TEMPLATE_TEMPLATE_PARM:
11239 case TEMPLATE_PARM_INDEX:
11244 tree arg = NULL_TREE;
11248 gcc_assert (TREE_VEC_LENGTH (args) > 0);
11249 template_parm_level_and_index (t, &level, &idx);
11251 levels = TMPL_ARGS_DEPTH (args);
11252 if (level <= levels)
11254 arg = TMPL_ARG (args, level, idx);
11256 if (arg && TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
11257 /* See through ARGUMENT_PACK_SELECT arguments. */
11258 arg = ARGUMENT_PACK_SELECT_ARG (arg);
11261 if (arg == error_mark_node)
11262 return error_mark_node;
11263 else if (arg != NULL_TREE)
11265 if (ARGUMENT_PACK_P (arg))
11266 /* If ARG is an argument pack, we don't actually want to
11267 perform a substitution here, because substitutions
11268 for argument packs are only done
11269 element-by-element. We can get to this point when
11270 substituting the type of a non-type template
11271 parameter pack, when that type actually contains
11272 template parameter packs from an outer template, e.g.,
11274 template<typename... Types> struct A {
11275 template<Types... Values> struct B { };
11279 if (code == TEMPLATE_TYPE_PARM)
11282 gcc_assert (TYPE_P (arg));
11284 quals = cp_type_quals (arg) | cp_type_quals (t);
11286 return cp_build_qualified_type_real
11287 (arg, quals, complain | tf_ignore_bad_quals);
11289 else if (code == BOUND_TEMPLATE_TEMPLATE_PARM)
11291 /* We are processing a type constructed from a
11292 template template parameter. */
11293 tree argvec = tsubst (TYPE_TI_ARGS (t),
11294 args, complain, in_decl);
11295 if (argvec == error_mark_node)
11296 return error_mark_node;
11298 gcc_assert (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
11299 || TREE_CODE (arg) == TEMPLATE_DECL
11300 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE);
11302 if (TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE)
11303 /* Consider this code:
11305 template <template <class> class Template>
11307 template <class Arg> using Bind = Template<Arg>;
11310 template <template <class> class Template, class Arg>
11311 using Instantiate = Template<Arg>; //#0
11313 template <template <class> class Template,
11316 Instantiate<Internal<Template>::template Bind,
11319 When #1 is parsed, the
11320 BOUND_TEMPLATE_TEMPLATE_PARM representing the
11321 parameter `Template' in #0 matches the
11322 UNBOUND_CLASS_TEMPLATE representing the argument
11323 `Internal<Template>::template Bind'; We then want
11324 to assemble the type `Bind<Argument>' that can't
11325 be fully created right now, because
11326 `Internal<Template>' not being complete, the Bind
11327 template cannot be looked up in that context. So
11328 we need to "store" `Bind<Argument>' for later
11329 when the context of Bind becomes complete. Let's
11330 store that in a TYPENAME_TYPE. */
11331 return make_typename_type (TYPE_CONTEXT (arg),
11332 build_nt (TEMPLATE_ID_EXPR,
11333 TYPE_IDENTIFIER (arg),
11338 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
11339 are resolving nested-types in the signature of a
11340 member function templates. Otherwise ARG is a
11341 TEMPLATE_DECL and is the real template to be
11343 if (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
11344 arg = TYPE_NAME (arg);
11346 r = lookup_template_class (arg,
11348 DECL_CONTEXT (arg),
11349 /*entering_scope=*/0,
11351 return cp_build_qualified_type_real
11352 (r, cp_type_quals (t), complain);
11355 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
11356 return convert_from_reference (unshare_expr (arg));
11360 /* This can happen during the attempted tsubst'ing in
11361 unify. This means that we don't yet have any information
11362 about the template parameter in question. */
11365 /* If we get here, we must have been looking at a parm for a
11366 more deeply nested template. Make a new version of this
11367 template parameter, but with a lower level. */
11370 case TEMPLATE_TYPE_PARM:
11371 case TEMPLATE_TEMPLATE_PARM:
11372 case BOUND_TEMPLATE_TEMPLATE_PARM:
11373 if (cp_type_quals (t))
11375 r = tsubst (TYPE_MAIN_VARIANT (t), args, complain, in_decl);
11376 r = cp_build_qualified_type_real
11377 (r, cp_type_quals (t),
11378 complain | (code == TEMPLATE_TYPE_PARM
11379 ? tf_ignore_bad_quals : 0));
11384 TEMPLATE_TYPE_PARM_INDEX (r)
11385 = reduce_template_parm_level (TEMPLATE_TYPE_PARM_INDEX (t),
11386 r, levels, args, complain);
11387 TYPE_STUB_DECL (r) = TYPE_NAME (r) = TEMPLATE_TYPE_DECL (r);
11388 TYPE_MAIN_VARIANT (r) = r;
11389 TYPE_POINTER_TO (r) = NULL_TREE;
11390 TYPE_REFERENCE_TO (r) = NULL_TREE;
11392 if (TREE_CODE (r) == TEMPLATE_TEMPLATE_PARM)
11393 /* We have reduced the level of the template
11394 template parameter, but not the levels of its
11395 template parameters, so canonical_type_parameter
11396 will not be able to find the canonical template
11397 template parameter for this level. Thus, we
11398 require structural equality checking to compare
11399 TEMPLATE_TEMPLATE_PARMs. */
11400 SET_TYPE_STRUCTURAL_EQUALITY (r);
11401 else if (TYPE_STRUCTURAL_EQUALITY_P (t))
11402 SET_TYPE_STRUCTURAL_EQUALITY (r);
11404 TYPE_CANONICAL (r) = canonical_type_parameter (r);
11406 if (code == BOUND_TEMPLATE_TEMPLATE_PARM)
11408 tree argvec = tsubst (TYPE_TI_ARGS (t), args,
11409 complain, in_decl);
11410 if (argvec == error_mark_node)
11411 return error_mark_node;
11413 TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (r)
11414 = build_template_info (TYPE_TI_TEMPLATE (t), argvec);
11419 case TEMPLATE_PARM_INDEX:
11420 r = reduce_template_parm_level (t, type, levels, args, complain);
11424 gcc_unreachable ();
11432 tree purpose, value, chain;
11434 if (t == void_list_node)
11437 purpose = TREE_PURPOSE (t);
11440 purpose = tsubst (purpose, args, complain, in_decl);
11441 if (purpose == error_mark_node)
11442 return error_mark_node;
11444 value = TREE_VALUE (t);
11447 value = tsubst (value, args, complain, in_decl);
11448 if (value == error_mark_node)
11449 return error_mark_node;
11451 chain = TREE_CHAIN (t);
11452 if (chain && chain != void_type_node)
11454 chain = tsubst (chain, args, complain, in_decl);
11455 if (chain == error_mark_node)
11456 return error_mark_node;
11458 if (purpose == TREE_PURPOSE (t)
11459 && value == TREE_VALUE (t)
11460 && chain == TREE_CHAIN (t))
11462 return hash_tree_cons (purpose, value, chain);
11466 /* We should never be tsubsting a binfo. */
11467 gcc_unreachable ();
11470 /* A vector of template arguments. */
11471 gcc_assert (!type);
11472 return tsubst_template_args (t, args, complain, in_decl);
11475 case REFERENCE_TYPE:
11477 if (type == TREE_TYPE (t) && TREE_CODE (type) != METHOD_TYPE)
11482 Type deduction may fail for any of the following
11485 -- Attempting to create a pointer to reference type.
11486 -- Attempting to create a reference to a reference type or
11487 a reference to void.
11489 Core issue 106 says that creating a reference to a reference
11490 during instantiation is no longer a cause for failure. We
11491 only enforce this check in strict C++98 mode. */
11492 if ((TREE_CODE (type) == REFERENCE_TYPE
11493 && (((cxx_dialect == cxx98) && flag_iso) || code != REFERENCE_TYPE))
11494 || (code == REFERENCE_TYPE && TREE_CODE (type) == VOID_TYPE))
11496 static location_t last_loc;
11498 /* We keep track of the last time we issued this error
11499 message to avoid spewing a ton of messages during a
11500 single bad template instantiation. */
11501 if (complain & tf_error
11502 && last_loc != input_location)
11504 if (TREE_CODE (type) == VOID_TYPE)
11505 error ("forming reference to void");
11506 else if (code == POINTER_TYPE)
11507 error ("forming pointer to reference type %qT", type);
11509 error ("forming reference to reference type %qT", type);
11510 last_loc = input_location;
11513 return error_mark_node;
11515 else if (code == POINTER_TYPE)
11517 r = build_pointer_type (type);
11518 if (TREE_CODE (type) == METHOD_TYPE)
11519 r = build_ptrmemfunc_type (r);
11521 else if (TREE_CODE (type) == REFERENCE_TYPE)
11522 /* In C++0x, during template argument substitution, when there is an
11523 attempt to create a reference to a reference type, reference
11524 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
11526 "If a template-argument for a template-parameter T names a type
11527 that is a reference to a type A, an attempt to create the type
11528 'lvalue reference to cv T' creates the type 'lvalue reference to
11529 A,' while an attempt to create the type type rvalue reference to
11530 cv T' creates the type T"
11532 r = cp_build_reference_type
11534 TYPE_REF_IS_RVALUE (t) && TYPE_REF_IS_RVALUE (type));
11536 r = cp_build_reference_type (type, TYPE_REF_IS_RVALUE (t));
11537 r = cp_build_qualified_type_real (r, cp_type_quals (t), complain);
11539 if (r != error_mark_node)
11540 /* Will this ever be needed for TYPE_..._TO values? */
11547 r = tsubst (TYPE_OFFSET_BASETYPE (t), args, complain, in_decl);
11548 if (r == error_mark_node || !MAYBE_CLASS_TYPE_P (r))
11552 Type deduction may fail for any of the following
11555 -- Attempting to create "pointer to member of T" when T
11556 is not a class type. */
11557 if (complain & tf_error)
11558 error ("creating pointer to member of non-class type %qT", r);
11559 return error_mark_node;
11561 if (TREE_CODE (type) == REFERENCE_TYPE)
11563 if (complain & tf_error)
11564 error ("creating pointer to member reference type %qT", type);
11565 return error_mark_node;
11567 if (TREE_CODE (type) == VOID_TYPE)
11569 if (complain & tf_error)
11570 error ("creating pointer to member of type void");
11571 return error_mark_node;
11573 gcc_assert (TREE_CODE (type) != METHOD_TYPE);
11574 if (TREE_CODE (type) == FUNCTION_TYPE)
11576 /* The type of the implicit object parameter gets its
11577 cv-qualifiers from the FUNCTION_TYPE. */
11579 tree method_type = build_memfn_type (type, r, type_memfn_quals (type));
11580 memptr = build_ptrmemfunc_type (build_pointer_type (method_type));
11581 return cp_build_qualified_type_real (memptr, cp_type_quals (t),
11585 return cp_build_qualified_type_real (build_ptrmem_type (r, type),
11589 case FUNCTION_TYPE:
11594 fntype = tsubst_function_type (t, args, complain, in_decl);
11595 if (fntype == error_mark_node)
11596 return error_mark_node;
11598 /* Substitute the exception specification. */
11599 specs = tsubst_exception_specification (t, args, complain,
11600 in_decl, /*defer_ok*/true);
11601 if (specs == error_mark_node)
11602 return error_mark_node;
11604 fntype = build_exception_variant (fntype, specs);
11609 tree domain = tsubst (TYPE_DOMAIN (t), args, complain, in_decl);
11610 if (domain == error_mark_node)
11611 return error_mark_node;
11613 /* As an optimization, we avoid regenerating the array type if
11614 it will obviously be the same as T. */
11615 if (type == TREE_TYPE (t) && domain == TYPE_DOMAIN (t))
11618 /* These checks should match the ones in grokdeclarator.
11622 The deduction may fail for any of the following reasons:
11624 -- Attempting to create an array with an element type that
11625 is void, a function type, or a reference type, or [DR337]
11626 an abstract class type. */
11627 if (TREE_CODE (type) == VOID_TYPE
11628 || TREE_CODE (type) == FUNCTION_TYPE
11629 || TREE_CODE (type) == REFERENCE_TYPE)
11631 if (complain & tf_error)
11632 error ("creating array of %qT", type);
11633 return error_mark_node;
11635 if (CLASS_TYPE_P (type) && CLASSTYPE_PURE_VIRTUALS (type))
11637 if (complain & tf_error)
11638 error ("creating array of %qT, which is an abstract class type",
11640 return error_mark_node;
11643 r = build_cplus_array_type (type, domain);
11645 if (TYPE_USER_ALIGN (t))
11647 TYPE_ALIGN (r) = TYPE_ALIGN (t);
11648 TYPE_USER_ALIGN (r) = 1;
11654 case TYPENAME_TYPE:
11656 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
11657 in_decl, /*entering_scope=*/1);
11658 tree f = tsubst_copy (TYPENAME_TYPE_FULLNAME (t), args,
11659 complain, in_decl);
11661 if (ctx == error_mark_node || f == error_mark_node)
11662 return error_mark_node;
11664 if (!MAYBE_CLASS_TYPE_P (ctx))
11666 if (complain & tf_error)
11667 error ("%qT is not a class, struct, or union type", ctx);
11668 return error_mark_node;
11670 else if (!uses_template_parms (ctx) && !TYPE_BEING_DEFINED (ctx))
11672 /* Normally, make_typename_type does not require that the CTX
11673 have complete type in order to allow things like:
11675 template <class T> struct S { typename S<T>::X Y; };
11677 But, such constructs have already been resolved by this
11678 point, so here CTX really should have complete type, unless
11679 it's a partial instantiation. */
11680 ctx = complete_type (ctx);
11681 if (!COMPLETE_TYPE_P (ctx))
11683 if (complain & tf_error)
11684 cxx_incomplete_type_error (NULL_TREE, ctx);
11685 return error_mark_node;
11689 f = make_typename_type (ctx, f, typename_type,
11690 (complain & tf_error) | tf_keep_type_decl);
11691 if (f == error_mark_node)
11693 if (TREE_CODE (f) == TYPE_DECL)
11695 complain |= tf_ignore_bad_quals;
11699 if (TREE_CODE (f) != TYPENAME_TYPE)
11701 if (TYPENAME_IS_ENUM_P (t) && TREE_CODE (f) != ENUMERAL_TYPE)
11703 if (complain & tf_error)
11704 error ("%qT resolves to %qT, which is not an enumeration type",
11707 return error_mark_node;
11709 else if (TYPENAME_IS_CLASS_P (t) && !CLASS_TYPE_P (f))
11711 if (complain & tf_error)
11712 error ("%qT resolves to %qT, which is is not a class type",
11715 return error_mark_node;
11719 return cp_build_qualified_type_real
11720 (f, cp_type_quals (f) | cp_type_quals (t), complain);
11723 case UNBOUND_CLASS_TEMPLATE:
11725 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
11726 in_decl, /*entering_scope=*/1);
11727 tree name = TYPE_IDENTIFIER (t);
11728 tree parm_list = DECL_TEMPLATE_PARMS (TYPE_NAME (t));
11730 if (ctx == error_mark_node || name == error_mark_node)
11731 return error_mark_node;
11734 parm_list = tsubst_template_parms (parm_list, args, complain);
11735 return make_unbound_class_template (ctx, name, parm_list, complain);
11742 ++cp_unevaluated_operand;
11743 ++c_inhibit_evaluation_warnings;
11745 type = tsubst_expr (TYPEOF_TYPE_EXPR (t), args,
11747 /*integral_constant_expression_p=*/false);
11749 --cp_unevaluated_operand;
11750 --c_inhibit_evaluation_warnings;
11752 type = finish_typeof (type);
11753 return cp_build_qualified_type_real (type,
11755 | cp_type_quals (type),
11759 case DECLTYPE_TYPE:
11763 ++cp_unevaluated_operand;
11764 ++c_inhibit_evaluation_warnings;
11766 type = tsubst_expr (DECLTYPE_TYPE_EXPR (t), args,
11768 /*integral_constant_expression_p=*/false);
11770 --cp_unevaluated_operand;
11771 --c_inhibit_evaluation_warnings;
11773 if (DECLTYPE_FOR_LAMBDA_CAPTURE (t))
11774 type = lambda_capture_field_type (type);
11775 else if (DECLTYPE_FOR_LAMBDA_PROXY (t))
11776 type = lambda_proxy_type (type);
11778 type = finish_decltype_type
11779 (type, DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t), complain);
11780 return cp_build_qualified_type_real (type,
11782 | cp_type_quals (type),
11786 case UNDERLYING_TYPE:
11788 tree type = tsubst (UNDERLYING_TYPE_TYPE (t), args,
11789 complain, in_decl);
11790 return finish_underlying_type (type);
11793 case TYPE_ARGUMENT_PACK:
11794 case NONTYPE_ARGUMENT_PACK:
11796 tree r = TYPE_P (t) ? cxx_make_type (code) : make_node (code);
11798 tsubst_template_args (ARGUMENT_PACK_ARGS (t),
11802 SET_ARGUMENT_PACK_ARGS (r, packed_out);
11804 /* For template nontype argument packs, also substitute into
11806 if (code == NONTYPE_ARGUMENT_PACK)
11807 TREE_TYPE (r) = tsubst (TREE_TYPE (t), args, complain, in_decl);
11825 /* We should use one of the expression tsubsts for these codes. */
11826 gcc_unreachable ();
11829 sorry ("use of %qs in template", tree_code_name [(int) code]);
11830 return error_mark_node;
11834 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
11835 type of the expression on the left-hand side of the "." or "->"
11839 tsubst_baselink (tree baselink, tree object_type,
11840 tree args, tsubst_flags_t complain, tree in_decl)
11843 tree qualifying_scope;
11846 tree template_args = 0;
11847 bool template_id_p = false;
11849 /* A baselink indicates a function from a base class. Both the
11850 BASELINK_ACCESS_BINFO and the base class referenced may
11851 indicate bases of the template class, rather than the
11852 instantiated class. In addition, lookups that were not
11853 ambiguous before may be ambiguous now. Therefore, we perform
11854 the lookup again. */
11855 qualifying_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (baselink));
11856 qualifying_scope = tsubst (qualifying_scope, args,
11857 complain, in_decl);
11858 fns = BASELINK_FUNCTIONS (baselink);
11859 optype = tsubst (BASELINK_OPTYPE (baselink), args, complain, in_decl);
11860 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
11862 template_id_p = true;
11863 template_args = TREE_OPERAND (fns, 1);
11864 fns = TREE_OPERAND (fns, 0);
11866 template_args = tsubst_template_args (template_args, args,
11867 complain, in_decl);
11869 name = DECL_NAME (get_first_fn (fns));
11870 if (IDENTIFIER_TYPENAME_P (name))
11871 name = mangle_conv_op_name_for_type (optype);
11872 baselink = lookup_fnfields (qualifying_scope, name, /*protect=*/1);
11874 return error_mark_node;
11876 /* If lookup found a single function, mark it as used at this
11877 point. (If it lookup found multiple functions the one selected
11878 later by overload resolution will be marked as used at that
11880 if (BASELINK_P (baselink))
11881 fns = BASELINK_FUNCTIONS (baselink);
11882 if (!template_id_p && !really_overloaded_fn (fns))
11883 mark_used (OVL_CURRENT (fns));
11885 /* Add back the template arguments, if present. */
11886 if (BASELINK_P (baselink) && template_id_p)
11887 BASELINK_FUNCTIONS (baselink)
11888 = build_nt (TEMPLATE_ID_EXPR,
11889 BASELINK_FUNCTIONS (baselink),
11891 /* Update the conversion operator type. */
11892 BASELINK_OPTYPE (baselink) = optype;
11895 object_type = current_class_type;
11896 return adjust_result_of_qualified_name_lookup (baselink,
11901 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
11902 true if the qualified-id will be a postfix-expression in-and-of
11903 itself; false if more of the postfix-expression follows the
11904 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
11908 tsubst_qualified_id (tree qualified_id, tree args,
11909 tsubst_flags_t complain, tree in_decl,
11910 bool done, bool address_p)
11916 tree template_args;
11918 gcc_assert (TREE_CODE (qualified_id) == SCOPE_REF);
11920 /* Figure out what name to look up. */
11921 name = TREE_OPERAND (qualified_id, 1);
11922 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
11924 is_template = true;
11925 template_args = TREE_OPERAND (name, 1);
11927 template_args = tsubst_template_args (template_args, args,
11928 complain, in_decl);
11929 name = TREE_OPERAND (name, 0);
11933 is_template = false;
11934 template_args = NULL_TREE;
11937 /* Substitute into the qualifying scope. When there are no ARGS, we
11938 are just trying to simplify a non-dependent expression. In that
11939 case the qualifying scope may be dependent, and, in any case,
11940 substituting will not help. */
11941 scope = TREE_OPERAND (qualified_id, 0);
11944 scope = tsubst (scope, args, complain, in_decl);
11945 expr = tsubst_copy (name, args, complain, in_decl);
11950 if (dependent_scope_p (scope))
11953 expr = build_min_nt (TEMPLATE_ID_EXPR, expr, template_args);
11954 return build_qualified_name (NULL_TREE, scope, expr,
11955 QUALIFIED_NAME_IS_TEMPLATE (qualified_id));
11958 if (!BASELINK_P (name) && !DECL_P (expr))
11960 if (TREE_CODE (expr) == BIT_NOT_EXPR)
11962 /* A BIT_NOT_EXPR is used to represent a destructor. */
11963 if (!check_dtor_name (scope, TREE_OPERAND (expr, 0)))
11965 error ("qualifying type %qT does not match destructor name ~%qT",
11966 scope, TREE_OPERAND (expr, 0));
11967 expr = error_mark_node;
11970 expr = lookup_qualified_name (scope, complete_dtor_identifier,
11971 /*is_type_p=*/0, false);
11974 expr = lookup_qualified_name (scope, expr, /*is_type_p=*/0, false);
11975 if (TREE_CODE (TREE_CODE (expr) == TEMPLATE_DECL
11976 ? DECL_TEMPLATE_RESULT (expr) : expr) == TYPE_DECL)
11978 if (complain & tf_error)
11980 error ("dependent-name %qE is parsed as a non-type, but "
11981 "instantiation yields a type", qualified_id);
11982 inform (input_location, "say %<typename %E%> if a type is meant", qualified_id);
11984 return error_mark_node;
11990 check_accessibility_of_qualified_id (expr, /*object_type=*/NULL_TREE,
11992 /* Remember that there was a reference to this entity. */
11996 if (expr == error_mark_node || TREE_CODE (expr) == TREE_LIST)
11998 if (complain & tf_error)
11999 qualified_name_lookup_error (scope,
12000 TREE_OPERAND (qualified_id, 1),
12001 expr, input_location);
12002 return error_mark_node;
12006 expr = lookup_template_function (expr, template_args);
12008 if (expr == error_mark_node && complain & tf_error)
12009 qualified_name_lookup_error (scope, TREE_OPERAND (qualified_id, 1),
12010 expr, input_location);
12011 else if (TYPE_P (scope))
12013 expr = (adjust_result_of_qualified_name_lookup
12014 (expr, scope, current_class_type));
12015 expr = (finish_qualified_id_expr
12016 (scope, expr, done, address_p && PTRMEM_OK_P (qualified_id),
12017 QUALIFIED_NAME_IS_TEMPLATE (qualified_id),
12018 /*template_arg_p=*/false));
12021 /* Expressions do not generally have reference type. */
12022 if (TREE_CODE (expr) != SCOPE_REF
12023 /* However, if we're about to form a pointer-to-member, we just
12024 want the referenced member referenced. */
12025 && TREE_CODE (expr) != OFFSET_REF)
12026 expr = convert_from_reference (expr);
12031 /* Like tsubst, but deals with expressions. This function just replaces
12032 template parms; to finish processing the resultant expression, use
12033 tsubst_copy_and_build or tsubst_expr. */
12036 tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl)
12038 enum tree_code code;
12041 if (t == NULL_TREE || t == error_mark_node || args == NULL_TREE)
12044 code = TREE_CODE (t);
12049 r = retrieve_local_specialization (t);
12055 /* We get here for a use of 'this' in an NSDMI. */
12056 if (DECL_NAME (t) == this_identifier
12057 && at_function_scope_p ()
12058 && DECL_CONSTRUCTOR_P (current_function_decl))
12059 return current_class_ptr;
12061 /* This can happen for a parameter name used later in a function
12062 declaration (such as in a late-specified return type). Just
12063 make a dummy decl, since it's only used for its type. */
12064 gcc_assert (cp_unevaluated_operand != 0);
12065 /* We copy T because want to tsubst the PARM_DECL only,
12066 not the following PARM_DECLs that are chained to T. */
12068 r = tsubst_decl (c, args, complain);
12069 /* Give it the template pattern as its context; its true context
12070 hasn't been instantiated yet and this is good enough for
12072 DECL_CONTEXT (r) = DECL_CONTEXT (t);
12075 if (TREE_CODE (r) == ARGUMENT_PACK_SELECT)
12076 r = ARGUMENT_PACK_SELECT_ARG (r);
12085 if (DECL_TEMPLATE_PARM_P (t))
12086 return tsubst_copy (DECL_INITIAL (t), args, complain, in_decl);
12087 /* There is no need to substitute into namespace-scope
12089 if (DECL_NAMESPACE_SCOPE_P (t))
12091 /* If ARGS is NULL, then T is known to be non-dependent. */
12092 if (args == NULL_TREE)
12093 return integral_constant_value (t);
12095 /* Unfortunately, we cannot just call lookup_name here.
12098 template <int I> int f() {
12100 struct S { void g() { E e = a; } };
12103 When we instantiate f<7>::S::g(), say, lookup_name is not
12104 clever enough to find f<7>::a. */
12106 = tsubst_aggr_type (TREE_TYPE (t), args, complain, in_decl,
12107 /*entering_scope=*/0);
12109 for (v = TYPE_VALUES (enum_type);
12111 v = TREE_CHAIN (v))
12112 if (TREE_PURPOSE (v) == DECL_NAME (t))
12113 return TREE_VALUE (v);
12115 /* We didn't find the name. That should never happen; if
12116 name-lookup found it during preliminary parsing, we
12117 should find it again here during instantiation. */
12118 gcc_unreachable ();
12123 if (DECL_CONTEXT (t))
12127 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args, complain, in_decl,
12128 /*entering_scope=*/1);
12129 if (ctx != DECL_CONTEXT (t))
12131 tree r = lookup_field (ctx, DECL_NAME (t), 0, false);
12134 if (complain & tf_error)
12135 error ("using invalid field %qD", t);
12136 return error_mark_node;
12145 case FUNCTION_DECL:
12146 if ((DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t))
12147 || local_variable_p (t))
12148 t = tsubst (t, args, complain, in_decl);
12152 case NAMESPACE_DECL:
12156 /* An OVERLOAD will always be a non-dependent overload set; an
12157 overload set from function scope will just be represented with an
12158 IDENTIFIER_NODE, and from class scope with a BASELINK. */
12159 gcc_assert (!uses_template_parms (t));
12163 return tsubst_baselink (t, current_class_type, args, complain, in_decl);
12165 case TEMPLATE_DECL:
12166 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
12167 return tsubst (TREE_TYPE (DECL_TEMPLATE_RESULT (t)),
12168 args, complain, in_decl);
12169 else if (DECL_FUNCTION_TEMPLATE_P (t) && DECL_MEMBER_TEMPLATE_P (t))
12170 return tsubst (t, args, complain, in_decl);
12171 else if (DECL_CLASS_SCOPE_P (t)
12172 && uses_template_parms (DECL_CONTEXT (t)))
12174 /* Template template argument like the following example need
12177 template <template <class> class TT> struct C {};
12178 template <class T> struct D {
12179 template <class U> struct E {};
12184 We are processing the template argument `E' in #1 for
12185 the template instantiation #2. Originally, `E' is a
12186 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
12187 have to substitute this with one having context `D<int>'. */
12189 tree context = tsubst (DECL_CONTEXT (t), args, complain, in_decl);
12190 return lookup_field (context, DECL_NAME(t), 0, false);
12193 /* Ordinary template template argument. */
12197 case REINTERPRET_CAST_EXPR:
12198 case CONST_CAST_EXPR:
12199 case STATIC_CAST_EXPR:
12200 case DYNAMIC_CAST_EXPR:
12201 case IMPLICIT_CONV_EXPR:
12205 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
12206 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
12209 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
12215 ++cp_unevaluated_operand;
12216 ++c_inhibit_evaluation_warnings;
12217 /* We only want to compute the number of arguments. */
12218 expanded = tsubst_pack_expansion (TREE_OPERAND (t, 0), args,
12219 complain, in_decl);
12220 --cp_unevaluated_operand;
12221 --c_inhibit_evaluation_warnings;
12223 if (TREE_CODE (expanded) == TREE_VEC)
12224 len = TREE_VEC_LENGTH (expanded);
12226 if (expanded == error_mark_node)
12227 return error_mark_node;
12228 else if (PACK_EXPANSION_P (expanded)
12229 || (TREE_CODE (expanded) == TREE_VEC
12231 && PACK_EXPANSION_P (TREE_VEC_ELT (expanded, len-1))))
12233 if (TREE_CODE (expanded) == TREE_VEC)
12234 expanded = TREE_VEC_ELT (expanded, len - 1);
12236 if (TYPE_P (expanded))
12237 return cxx_sizeof_or_alignof_type (expanded, SIZEOF_EXPR,
12238 complain & tf_error);
12240 return cxx_sizeof_or_alignof_expr (expanded, SIZEOF_EXPR,
12241 complain & tf_error);
12244 return build_int_cst (size_type_node, len);
12250 case TRUTH_NOT_EXPR:
12253 case UNARY_PLUS_EXPR: /* Unary + */
12255 case AT_ENCODE_EXPR:
12259 case REALPART_EXPR:
12260 case IMAGPART_EXPR:
12262 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
12263 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
12265 case COMPONENT_REF:
12270 object = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
12271 name = TREE_OPERAND (t, 1);
12272 if (TREE_CODE (name) == BIT_NOT_EXPR)
12274 name = tsubst_copy (TREE_OPERAND (name, 0), args,
12275 complain, in_decl);
12276 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
12278 else if (TREE_CODE (name) == SCOPE_REF
12279 && TREE_CODE (TREE_OPERAND (name, 1)) == BIT_NOT_EXPR)
12281 tree base = tsubst_copy (TREE_OPERAND (name, 0), args,
12282 complain, in_decl);
12283 name = TREE_OPERAND (name, 1);
12284 name = tsubst_copy (TREE_OPERAND (name, 0), args,
12285 complain, in_decl);
12286 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
12287 name = build_qualified_name (/*type=*/NULL_TREE,
12289 /*template_p=*/false);
12291 else if (BASELINK_P (name))
12292 name = tsubst_baselink (name,
12293 non_reference (TREE_TYPE (object)),
12297 name = tsubst_copy (name, args, complain, in_decl);
12298 return build_nt (COMPONENT_REF, object, name, NULL_TREE);
12304 case TRUNC_DIV_EXPR:
12305 case CEIL_DIV_EXPR:
12306 case FLOOR_DIV_EXPR:
12307 case ROUND_DIV_EXPR:
12308 case EXACT_DIV_EXPR:
12312 case TRUNC_MOD_EXPR:
12313 case FLOOR_MOD_EXPR:
12314 case TRUTH_ANDIF_EXPR:
12315 case TRUTH_ORIF_EXPR:
12316 case TRUTH_AND_EXPR:
12317 case TRUTH_OR_EXPR:
12330 case COMPOUND_EXPR:
12333 case PREDECREMENT_EXPR:
12334 case PREINCREMENT_EXPR:
12335 case POSTDECREMENT_EXPR:
12336 case POSTINCREMENT_EXPR:
12338 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12339 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
12342 return build_qualified_name (/*type=*/NULL_TREE,
12343 tsubst_copy (TREE_OPERAND (t, 0),
12344 args, complain, in_decl),
12345 tsubst_copy (TREE_OPERAND (t, 1),
12346 args, complain, in_decl),
12347 QUALIFIED_NAME_IS_TEMPLATE (t));
12352 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12353 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
12354 NULL_TREE, NULL_TREE);
12358 int n = VL_EXP_OPERAND_LENGTH (t);
12359 tree result = build_vl_exp (CALL_EXPR, n);
12361 for (i = 0; i < n; i++)
12362 TREE_OPERAND (t, i) = tsubst_copy (TREE_OPERAND (t, i), args,
12363 complain, in_decl);
12369 case PSEUDO_DTOR_EXPR:
12372 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12373 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
12374 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
12375 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
12382 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12383 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
12384 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
12385 NEW_EXPR_USE_GLOBAL (r) = NEW_EXPR_USE_GLOBAL (t);
12392 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12393 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
12394 DELETE_EXPR_USE_GLOBAL (r) = DELETE_EXPR_USE_GLOBAL (t);
12395 DELETE_EXPR_USE_VEC (r) = DELETE_EXPR_USE_VEC (t);
12399 case TEMPLATE_ID_EXPR:
12401 /* Substituted template arguments */
12402 tree fn = TREE_OPERAND (t, 0);
12403 tree targs = TREE_OPERAND (t, 1);
12405 fn = tsubst_copy (fn, args, complain, in_decl);
12407 targs = tsubst_template_args (targs, args, complain, in_decl);
12409 return lookup_template_function (fn, targs);
12414 tree purpose, value, chain;
12416 if (t == void_list_node)
12419 purpose = TREE_PURPOSE (t);
12421 purpose = tsubst_copy (purpose, args, complain, in_decl);
12422 value = TREE_VALUE (t);
12424 value = tsubst_copy (value, args, complain, in_decl);
12425 chain = TREE_CHAIN (t);
12426 if (chain && chain != void_type_node)
12427 chain = tsubst_copy (chain, args, complain, in_decl);
12428 if (purpose == TREE_PURPOSE (t)
12429 && value == TREE_VALUE (t)
12430 && chain == TREE_CHAIN (t))
12432 return tree_cons (purpose, value, chain);
12437 case ENUMERAL_TYPE:
12439 case TEMPLATE_TYPE_PARM:
12440 case TEMPLATE_TEMPLATE_PARM:
12441 case BOUND_TEMPLATE_TEMPLATE_PARM:
12442 case TEMPLATE_PARM_INDEX:
12444 case REFERENCE_TYPE:
12446 case FUNCTION_TYPE:
12449 case TYPENAME_TYPE:
12450 case UNBOUND_CLASS_TEMPLATE:
12452 case DECLTYPE_TYPE:
12454 return tsubst (t, args, complain, in_decl);
12456 case IDENTIFIER_NODE:
12457 if (IDENTIFIER_TYPENAME_P (t))
12459 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12460 return mangle_conv_op_name_for_type (new_type);
12466 /* This is handled by tsubst_copy_and_build. */
12467 gcc_unreachable ();
12470 return build_x_va_arg (tsubst_copy (TREE_OPERAND (t, 0), args, complain,
12472 tsubst (TREE_TYPE (t), args, complain, in_decl));
12474 case CLEANUP_POINT_EXPR:
12475 /* We shouldn't have built any of these during initial template
12476 generation. Instead, they should be built during instantiation
12477 in response to the saved STMT_IS_FULL_EXPR_P setting. */
12478 gcc_unreachable ();
12482 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
12483 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12484 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
12485 PTRMEM_OK_P (r) = PTRMEM_OK_P (t);
12486 mark_used (TREE_OPERAND (r, 1));
12489 case EXPR_PACK_EXPANSION:
12490 error ("invalid use of pack expansion expression");
12491 return error_mark_node;
12493 case NONTYPE_ARGUMENT_PACK:
12494 error ("use %<...%> to expand argument pack");
12495 return error_mark_node;
12502 /* Instantiate any typedefs in the type. */
12503 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12504 r = fold_convert (type, t);
12505 gcc_assert (TREE_CODE (r) == code);
12510 /* These can sometimes show up in a partial instantiation, but never
12511 involve template parms. */
12512 gcc_assert (!uses_template_parms (t));
12516 /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */
12517 gcc_checking_assert (false);
12522 /* Like tsubst_copy, but specifically for OpenMP clauses. */
12525 tsubst_omp_clauses (tree clauses, tree args, tsubst_flags_t complain,
12528 tree new_clauses = NULL, nc, oc;
12530 for (oc = clauses; oc ; oc = OMP_CLAUSE_CHAIN (oc))
12532 nc = copy_node (oc);
12533 OMP_CLAUSE_CHAIN (nc) = new_clauses;
12536 switch (OMP_CLAUSE_CODE (nc))
12538 case OMP_CLAUSE_LASTPRIVATE:
12539 if (OMP_CLAUSE_LASTPRIVATE_STMT (oc))
12541 OMP_CLAUSE_LASTPRIVATE_STMT (nc) = push_stmt_list ();
12542 tsubst_expr (OMP_CLAUSE_LASTPRIVATE_STMT (oc), args, complain,
12543 in_decl, /*integral_constant_expression_p=*/false);
12544 OMP_CLAUSE_LASTPRIVATE_STMT (nc)
12545 = pop_stmt_list (OMP_CLAUSE_LASTPRIVATE_STMT (nc));
12548 case OMP_CLAUSE_PRIVATE:
12549 case OMP_CLAUSE_SHARED:
12550 case OMP_CLAUSE_FIRSTPRIVATE:
12551 case OMP_CLAUSE_REDUCTION:
12552 case OMP_CLAUSE_COPYIN:
12553 case OMP_CLAUSE_COPYPRIVATE:
12554 case OMP_CLAUSE_IF:
12555 case OMP_CLAUSE_NUM_THREADS:
12556 case OMP_CLAUSE_SCHEDULE:
12557 case OMP_CLAUSE_COLLAPSE:
12558 case OMP_CLAUSE_FINAL:
12559 OMP_CLAUSE_OPERAND (nc, 0)
12560 = tsubst_expr (OMP_CLAUSE_OPERAND (oc, 0), args, complain,
12561 in_decl, /*integral_constant_expression_p=*/false);
12563 case OMP_CLAUSE_NOWAIT:
12564 case OMP_CLAUSE_ORDERED:
12565 case OMP_CLAUSE_DEFAULT:
12566 case OMP_CLAUSE_UNTIED:
12567 case OMP_CLAUSE_MERGEABLE:
12570 gcc_unreachable ();
12574 return finish_omp_clauses (nreverse (new_clauses));
12577 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
12580 tsubst_copy_asm_operands (tree t, tree args, tsubst_flags_t complain,
12583 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
12585 tree purpose, value, chain;
12590 if (TREE_CODE (t) != TREE_LIST)
12591 return tsubst_copy_and_build (t, args, complain, in_decl,
12592 /*function_p=*/false,
12593 /*integral_constant_expression_p=*/false);
12595 if (t == void_list_node)
12598 purpose = TREE_PURPOSE (t);
12600 purpose = RECUR (purpose);
12601 value = TREE_VALUE (t);
12602 if (value && TREE_CODE (value) != LABEL_DECL)
12603 value = RECUR (value);
12604 chain = TREE_CHAIN (t);
12605 if (chain && chain != void_type_node)
12606 chain = RECUR (chain);
12607 return tree_cons (purpose, value, chain);
12611 /* Substitute one OMP_FOR iterator. */
12614 tsubst_omp_for_iterator (tree t, int i, tree declv, tree initv,
12615 tree condv, tree incrv, tree *clauses,
12616 tree args, tsubst_flags_t complain, tree in_decl,
12617 bool integral_constant_expression_p)
12619 #define RECUR(NODE) \
12620 tsubst_expr ((NODE), args, complain, in_decl, \
12621 integral_constant_expression_p)
12622 tree decl, init, cond, incr, auto_node;
12624 init = TREE_VEC_ELT (OMP_FOR_INIT (t), i);
12625 gcc_assert (TREE_CODE (init) == MODIFY_EXPR);
12626 decl = RECUR (TREE_OPERAND (init, 0));
12627 init = TREE_OPERAND (init, 1);
12628 auto_node = type_uses_auto (TREE_TYPE (decl));
12629 if (auto_node && init)
12631 tree init_expr = init;
12632 if (TREE_CODE (init_expr) == DECL_EXPR)
12633 init_expr = DECL_INITIAL (DECL_EXPR_DECL (init_expr));
12634 init_expr = RECUR (init_expr);
12636 = do_auto_deduction (TREE_TYPE (decl), init_expr, auto_node);
12638 gcc_assert (!type_dependent_expression_p (decl));
12640 if (!CLASS_TYPE_P (TREE_TYPE (decl)))
12642 cond = RECUR (TREE_VEC_ELT (OMP_FOR_COND (t), i));
12643 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
12644 if (TREE_CODE (incr) == MODIFY_EXPR)
12645 incr = build_x_modify_expr (RECUR (TREE_OPERAND (incr, 0)), NOP_EXPR,
12646 RECUR (TREE_OPERAND (incr, 1)),
12649 incr = RECUR (incr);
12650 TREE_VEC_ELT (declv, i) = decl;
12651 TREE_VEC_ELT (initv, i) = init;
12652 TREE_VEC_ELT (condv, i) = cond;
12653 TREE_VEC_ELT (incrv, i) = incr;
12657 if (init && TREE_CODE (init) != DECL_EXPR)
12660 for (c = *clauses; c ; c = OMP_CLAUSE_CHAIN (c))
12662 if ((OMP_CLAUSE_CODE (c) == OMP_CLAUSE_PRIVATE
12663 || OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LASTPRIVATE)
12664 && OMP_CLAUSE_DECL (c) == decl)
12666 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_FIRSTPRIVATE
12667 && OMP_CLAUSE_DECL (c) == decl)
12668 error ("iteration variable %qD should not be firstprivate", decl);
12669 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_REDUCTION
12670 && OMP_CLAUSE_DECL (c) == decl)
12671 error ("iteration variable %qD should not be reduction", decl);
12675 c = build_omp_clause (input_location, OMP_CLAUSE_PRIVATE);
12676 OMP_CLAUSE_DECL (c) = decl;
12677 c = finish_omp_clauses (c);
12680 OMP_CLAUSE_CHAIN (c) = *clauses;
12685 cond = TREE_VEC_ELT (OMP_FOR_COND (t), i);
12686 if (COMPARISON_CLASS_P (cond))
12687 cond = build2 (TREE_CODE (cond), boolean_type_node,
12688 RECUR (TREE_OPERAND (cond, 0)),
12689 RECUR (TREE_OPERAND (cond, 1)));
12691 cond = RECUR (cond);
12692 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
12693 switch (TREE_CODE (incr))
12695 case PREINCREMENT_EXPR:
12696 case PREDECREMENT_EXPR:
12697 case POSTINCREMENT_EXPR:
12698 case POSTDECREMENT_EXPR:
12699 incr = build2 (TREE_CODE (incr), TREE_TYPE (decl),
12700 RECUR (TREE_OPERAND (incr, 0)), NULL_TREE);
12703 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
12704 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
12706 tree rhs = TREE_OPERAND (incr, 1);
12707 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
12708 RECUR (TREE_OPERAND (incr, 0)),
12709 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
12710 RECUR (TREE_OPERAND (rhs, 0)),
12711 RECUR (TREE_OPERAND (rhs, 1))));
12714 incr = RECUR (incr);
12717 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
12718 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
12720 tree lhs = RECUR (TREE_OPERAND (incr, 0));
12721 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl), lhs,
12722 build2 (TREE_CODE (TREE_OPERAND (incr, 1)),
12723 TREE_TYPE (decl), lhs,
12724 RECUR (TREE_OPERAND (incr, 2))));
12726 else if (TREE_CODE (TREE_OPERAND (incr, 1)) == NOP_EXPR
12727 && (TREE_CODE (TREE_OPERAND (incr, 2)) == PLUS_EXPR
12728 || (TREE_CODE (TREE_OPERAND (incr, 2)) == MINUS_EXPR)))
12730 tree rhs = TREE_OPERAND (incr, 2);
12731 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
12732 RECUR (TREE_OPERAND (incr, 0)),
12733 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
12734 RECUR (TREE_OPERAND (rhs, 0)),
12735 RECUR (TREE_OPERAND (rhs, 1))));
12738 incr = RECUR (incr);
12741 incr = RECUR (incr);
12745 TREE_VEC_ELT (declv, i) = decl;
12746 TREE_VEC_ELT (initv, i) = init;
12747 TREE_VEC_ELT (condv, i) = cond;
12748 TREE_VEC_ELT (incrv, i) = incr;
12752 /* Like tsubst_copy for expressions, etc. but also does semantic
12756 tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl,
12757 bool integral_constant_expression_p)
12759 #define RECUR(NODE) \
12760 tsubst_expr ((NODE), args, complain, in_decl, \
12761 integral_constant_expression_p)
12765 if (t == NULL_TREE || t == error_mark_node)
12768 if (EXPR_HAS_LOCATION (t))
12769 input_location = EXPR_LOCATION (t);
12770 if (STATEMENT_CODE_P (TREE_CODE (t)))
12771 current_stmt_tree ()->stmts_are_full_exprs_p = STMT_IS_FULL_EXPR_P (t);
12773 switch (TREE_CODE (t))
12775 case STATEMENT_LIST:
12777 tree_stmt_iterator i;
12778 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
12779 RECUR (tsi_stmt (i));
12783 case CTOR_INITIALIZER:
12784 finish_mem_initializers (tsubst_initializer_list
12785 (TREE_OPERAND (t, 0), args));
12789 finish_return_stmt (RECUR (TREE_OPERAND (t, 0)));
12793 tmp = RECUR (EXPR_STMT_EXPR (t));
12794 if (EXPR_STMT_STMT_EXPR_RESULT (t))
12795 finish_stmt_expr_expr (tmp, cur_stmt_expr);
12797 finish_expr_stmt (tmp);
12801 do_using_directive (USING_STMT_NAMESPACE (t));
12806 tree decl, pattern_decl;
12809 pattern_decl = decl = DECL_EXPR_DECL (t);
12810 if (TREE_CODE (decl) == LABEL_DECL)
12811 finish_label_decl (DECL_NAME (decl));
12812 else if (TREE_CODE (decl) == USING_DECL)
12814 tree scope = USING_DECL_SCOPE (decl);
12815 tree name = DECL_NAME (decl);
12818 scope = tsubst (scope, args, complain, in_decl);
12819 decl = lookup_qualified_name (scope, name,
12820 /*is_type_p=*/false,
12821 /*complain=*/false);
12822 if (decl == error_mark_node || TREE_CODE (decl) == TREE_LIST)
12823 qualified_name_lookup_error (scope, name, decl, input_location);
12825 do_local_using_decl (decl, scope, name);
12829 init = DECL_INITIAL (decl);
12830 decl = tsubst (decl, args, complain, in_decl);
12831 if (decl != error_mark_node)
12833 /* By marking the declaration as instantiated, we avoid
12834 trying to instantiate it. Since instantiate_decl can't
12835 handle local variables, and since we've already done
12836 all that needs to be done, that's the right thing to
12838 if (TREE_CODE (decl) == VAR_DECL)
12839 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
12840 if (TREE_CODE (decl) == VAR_DECL
12841 && ANON_AGGR_TYPE_P (TREE_TYPE (decl)))
12842 /* Anonymous aggregates are a special case. */
12843 finish_anon_union (decl);
12844 else if (is_capture_proxy (DECL_EXPR_DECL (t)))
12846 DECL_CONTEXT (decl) = current_function_decl;
12847 insert_capture_proxy (decl);
12851 int const_init = false;
12852 maybe_push_decl (decl);
12853 if (TREE_CODE (decl) == VAR_DECL
12854 && DECL_PRETTY_FUNCTION_P (decl))
12856 /* For __PRETTY_FUNCTION__ we have to adjust the
12858 const char *const name
12859 = cxx_printable_name (current_function_decl, 2);
12860 init = cp_fname_init (name, &TREE_TYPE (decl));
12864 tree t = RECUR (init);
12868 /* If we had an initializer but it
12869 instantiated to nothing,
12870 value-initialize the object. This will
12871 only occur when the initializer was a
12872 pack expansion where the parameter packs
12873 used in that expansion were of length
12875 init = build_value_init (TREE_TYPE (decl),
12877 if (TREE_CODE (init) == AGGR_INIT_EXPR)
12878 init = get_target_expr_sfinae (init, complain);
12884 if (TREE_CODE (decl) == VAR_DECL)
12885 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
12887 cp_finish_decl (decl, init, const_init, NULL_TREE, 0);
12892 /* A DECL_EXPR can also be used as an expression, in the condition
12893 clause of an if/for/while construct. */
12898 stmt = begin_for_stmt (NULL_TREE, NULL_TREE);
12899 RECUR (FOR_INIT_STMT (t));
12900 finish_for_init_stmt (stmt);
12901 tmp = RECUR (FOR_COND (t));
12902 finish_for_cond (tmp, stmt);
12903 tmp = RECUR (FOR_EXPR (t));
12904 finish_for_expr (tmp, stmt);
12905 RECUR (FOR_BODY (t));
12906 finish_for_stmt (stmt);
12909 case RANGE_FOR_STMT:
12912 stmt = begin_for_stmt (NULL_TREE, NULL_TREE);
12913 decl = RANGE_FOR_DECL (t);
12914 decl = tsubst (decl, args, complain, in_decl);
12915 maybe_push_decl (decl);
12916 expr = RECUR (RANGE_FOR_EXPR (t));
12917 stmt = cp_convert_range_for (stmt, decl, expr);
12918 RECUR (RANGE_FOR_BODY (t));
12919 finish_for_stmt (stmt);
12924 stmt = begin_while_stmt ();
12925 tmp = RECUR (WHILE_COND (t));
12926 finish_while_stmt_cond (tmp, stmt);
12927 RECUR (WHILE_BODY (t));
12928 finish_while_stmt (stmt);
12932 stmt = begin_do_stmt ();
12933 RECUR (DO_BODY (t));
12934 finish_do_body (stmt);
12935 tmp = RECUR (DO_COND (t));
12936 finish_do_stmt (tmp, stmt);
12940 stmt = begin_if_stmt ();
12941 tmp = RECUR (IF_COND (t));
12942 finish_if_stmt_cond (tmp, stmt);
12943 RECUR (THEN_CLAUSE (t));
12944 finish_then_clause (stmt);
12946 if (ELSE_CLAUSE (t))
12948 begin_else_clause (stmt);
12949 RECUR (ELSE_CLAUSE (t));
12950 finish_else_clause (stmt);
12953 finish_if_stmt (stmt);
12957 if (BIND_EXPR_BODY_BLOCK (t))
12958 stmt = begin_function_body ();
12960 stmt = begin_compound_stmt (BIND_EXPR_TRY_BLOCK (t)
12961 ? BCS_TRY_BLOCK : 0);
12963 RECUR (BIND_EXPR_BODY (t));
12965 if (BIND_EXPR_BODY_BLOCK (t))
12966 finish_function_body (stmt);
12968 finish_compound_stmt (stmt);
12972 finish_break_stmt ();
12975 case CONTINUE_STMT:
12976 finish_continue_stmt ();
12980 stmt = begin_switch_stmt ();
12981 tmp = RECUR (SWITCH_STMT_COND (t));
12982 finish_switch_cond (tmp, stmt);
12983 RECUR (SWITCH_STMT_BODY (t));
12984 finish_switch_stmt (stmt);
12987 case CASE_LABEL_EXPR:
12988 finish_case_label (EXPR_LOCATION (t),
12989 RECUR (CASE_LOW (t)),
12990 RECUR (CASE_HIGH (t)));
12995 tree decl = LABEL_EXPR_LABEL (t);
12998 label = finish_label_stmt (DECL_NAME (decl));
12999 if (DECL_ATTRIBUTES (decl) != NULL_TREE)
13000 cplus_decl_attributes (&label, DECL_ATTRIBUTES (decl), 0);
13005 tmp = GOTO_DESTINATION (t);
13006 if (TREE_CODE (tmp) != LABEL_DECL)
13007 /* Computed goto's must be tsubst'd into. On the other hand,
13008 non-computed gotos must not be; the identifier in question
13009 will have no binding. */
13012 tmp = DECL_NAME (tmp);
13013 finish_goto_stmt (tmp);
13017 tmp = finish_asm_stmt
13018 (ASM_VOLATILE_P (t),
13019 RECUR (ASM_STRING (t)),
13020 tsubst_copy_asm_operands (ASM_OUTPUTS (t), args, complain, in_decl),
13021 tsubst_copy_asm_operands (ASM_INPUTS (t), args, complain, in_decl),
13022 tsubst_copy_asm_operands (ASM_CLOBBERS (t), args, complain, in_decl),
13023 tsubst_copy_asm_operands (ASM_LABELS (t), args, complain, in_decl));
13025 tree asm_expr = tmp;
13026 if (TREE_CODE (asm_expr) == CLEANUP_POINT_EXPR)
13027 asm_expr = TREE_OPERAND (asm_expr, 0);
13028 ASM_INPUT_P (asm_expr) = ASM_INPUT_P (t);
13035 stmt = begin_try_block ();
13036 RECUR (TRY_STMTS (t));
13037 finish_cleanup_try_block (stmt);
13038 finish_cleanup (RECUR (TRY_HANDLERS (t)), stmt);
13042 tree compound_stmt = NULL_TREE;
13044 if (FN_TRY_BLOCK_P (t))
13045 stmt = begin_function_try_block (&compound_stmt);
13047 stmt = begin_try_block ();
13049 RECUR (TRY_STMTS (t));
13051 if (FN_TRY_BLOCK_P (t))
13052 finish_function_try_block (stmt);
13054 finish_try_block (stmt);
13056 RECUR (TRY_HANDLERS (t));
13057 if (FN_TRY_BLOCK_P (t))
13058 finish_function_handler_sequence (stmt, compound_stmt);
13060 finish_handler_sequence (stmt);
13066 tree decl = HANDLER_PARMS (t);
13070 decl = tsubst (decl, args, complain, in_decl);
13071 /* Prevent instantiate_decl from trying to instantiate
13072 this variable. We've already done all that needs to be
13074 if (decl != error_mark_node)
13075 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
13077 stmt = begin_handler ();
13078 finish_handler_parms (decl, stmt);
13079 RECUR (HANDLER_BODY (t));
13080 finish_handler (stmt);
13085 tsubst (TREE_TYPE (t), args, complain, NULL_TREE);
13088 case STATIC_ASSERT:
13091 tsubst_expr (STATIC_ASSERT_CONDITION (t),
13094 /*integral_constant_expression_p=*/true);
13095 finish_static_assert (condition,
13096 STATIC_ASSERT_MESSAGE (t),
13097 STATIC_ASSERT_SOURCE_LOCATION (t),
13098 /*member_p=*/false);
13103 tmp = tsubst_omp_clauses (OMP_PARALLEL_CLAUSES (t),
13104 args, complain, in_decl);
13105 stmt = begin_omp_parallel ();
13106 RECUR (OMP_PARALLEL_BODY (t));
13107 OMP_PARALLEL_COMBINED (finish_omp_parallel (tmp, stmt))
13108 = OMP_PARALLEL_COMBINED (t);
13112 tmp = tsubst_omp_clauses (OMP_TASK_CLAUSES (t),
13113 args, complain, in_decl);
13114 stmt = begin_omp_task ();
13115 RECUR (OMP_TASK_BODY (t));
13116 finish_omp_task (tmp, stmt);
13121 tree clauses, body, pre_body;
13122 tree declv, initv, condv, incrv;
13125 clauses = tsubst_omp_clauses (OMP_FOR_CLAUSES (t),
13126 args, complain, in_decl);
13127 declv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
13128 initv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
13129 condv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
13130 incrv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
13132 for (i = 0; i < TREE_VEC_LENGTH (OMP_FOR_INIT (t)); i++)
13133 tsubst_omp_for_iterator (t, i, declv, initv, condv, incrv,
13134 &clauses, args, complain, in_decl,
13135 integral_constant_expression_p);
13137 stmt = begin_omp_structured_block ();
13139 for (i = 0; i < TREE_VEC_LENGTH (initv); i++)
13140 if (TREE_VEC_ELT (initv, i) == NULL
13141 || TREE_CODE (TREE_VEC_ELT (initv, i)) != DECL_EXPR)
13142 TREE_VEC_ELT (initv, i) = RECUR (TREE_VEC_ELT (initv, i));
13143 else if (CLASS_TYPE_P (TREE_TYPE (TREE_VEC_ELT (initv, i))))
13145 tree init = RECUR (TREE_VEC_ELT (initv, i));
13146 gcc_assert (init == TREE_VEC_ELT (declv, i));
13147 TREE_VEC_ELT (initv, i) = NULL_TREE;
13151 tree decl_expr = TREE_VEC_ELT (initv, i);
13152 tree init = DECL_INITIAL (DECL_EXPR_DECL (decl_expr));
13153 gcc_assert (init != NULL);
13154 TREE_VEC_ELT (initv, i) = RECUR (init);
13155 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = NULL;
13157 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = init;
13160 pre_body = push_stmt_list ();
13161 RECUR (OMP_FOR_PRE_BODY (t));
13162 pre_body = pop_stmt_list (pre_body);
13164 body = push_stmt_list ();
13165 RECUR (OMP_FOR_BODY (t));
13166 body = pop_stmt_list (body);
13168 t = finish_omp_for (EXPR_LOCATION (t), declv, initv, condv, incrv,
13169 body, pre_body, clauses);
13171 add_stmt (finish_omp_structured_block (stmt));
13177 tmp = tsubst_omp_clauses (OMP_CLAUSES (t), args, complain, in_decl);
13178 stmt = push_stmt_list ();
13179 RECUR (OMP_BODY (t));
13180 stmt = pop_stmt_list (stmt);
13183 OMP_BODY (t) = stmt;
13184 OMP_CLAUSES (t) = tmp;
13192 stmt = push_stmt_list ();
13193 RECUR (OMP_BODY (t));
13194 stmt = pop_stmt_list (stmt);
13197 OMP_BODY (t) = stmt;
13202 gcc_assert (OMP_ATOMIC_DEPENDENT_P (t));
13203 if (TREE_CODE (TREE_OPERAND (t, 1)) != MODIFY_EXPR)
13205 tree op1 = TREE_OPERAND (t, 1);
13206 tree rhs1 = NULL_TREE;
13208 if (TREE_CODE (op1) == COMPOUND_EXPR)
13210 rhs1 = RECUR (TREE_OPERAND (op1, 0));
13211 op1 = TREE_OPERAND (op1, 1);
13213 lhs = RECUR (TREE_OPERAND (op1, 0));
13214 rhs = RECUR (TREE_OPERAND (op1, 1));
13215 finish_omp_atomic (OMP_ATOMIC, TREE_CODE (op1), lhs, rhs,
13216 NULL_TREE, NULL_TREE, rhs1);
13220 tree op1 = TREE_OPERAND (t, 1);
13221 tree v = NULL_TREE, lhs, rhs = NULL_TREE, lhs1 = NULL_TREE;
13222 tree rhs1 = NULL_TREE;
13223 enum tree_code code = TREE_CODE (TREE_OPERAND (op1, 1));
13224 enum tree_code opcode = NOP_EXPR;
13225 if (code == OMP_ATOMIC_READ)
13227 v = RECUR (TREE_OPERAND (op1, 0));
13228 lhs = RECUR (TREE_OPERAND (TREE_OPERAND (op1, 1), 0));
13230 else if (code == OMP_ATOMIC_CAPTURE_OLD
13231 || code == OMP_ATOMIC_CAPTURE_NEW)
13233 tree op11 = TREE_OPERAND (TREE_OPERAND (op1, 1), 1);
13234 v = RECUR (TREE_OPERAND (op1, 0));
13235 lhs1 = RECUR (TREE_OPERAND (TREE_OPERAND (op1, 1), 0));
13236 if (TREE_CODE (op11) == COMPOUND_EXPR)
13238 rhs1 = RECUR (TREE_OPERAND (op11, 0));
13239 op11 = TREE_OPERAND (op11, 1);
13241 lhs = RECUR (TREE_OPERAND (op11, 0));
13242 rhs = RECUR (TREE_OPERAND (op11, 1));
13243 opcode = TREE_CODE (op11);
13248 lhs = RECUR (TREE_OPERAND (op1, 0));
13249 rhs = RECUR (TREE_OPERAND (op1, 1));
13251 finish_omp_atomic (code, opcode, lhs, rhs, v, lhs1, rhs1);
13255 case TRANSACTION_EXPR:
13258 flags |= (TRANSACTION_EXPR_OUTER (t) ? TM_STMT_ATTR_OUTER : 0);
13259 flags |= (TRANSACTION_EXPR_RELAXED (t) ? TM_STMT_ATTR_RELAXED : 0);
13261 if (TRANSACTION_EXPR_IS_STMT (t))
13263 tree body = TRANSACTION_EXPR_BODY (t);
13264 tree noex = NULL_TREE;
13265 if (TREE_CODE (body) == MUST_NOT_THROW_EXPR)
13267 noex = MUST_NOT_THROW_COND (body);
13268 if (noex == NULL_TREE)
13269 noex = boolean_true_node;
13270 body = TREE_OPERAND (body, 0);
13272 stmt = begin_transaction_stmt (input_location, NULL, flags);
13274 finish_transaction_stmt (stmt, NULL, flags, RECUR (noex));
13278 stmt = build_transaction_expr (EXPR_LOCATION (t),
13279 RECUR (TRANSACTION_EXPR_BODY (t)),
13286 case MUST_NOT_THROW_EXPR:
13287 return build_must_not_throw_expr (RECUR (TREE_OPERAND (t, 0)),
13288 RECUR (MUST_NOT_THROW_COND (t)));
13290 case EXPR_PACK_EXPANSION:
13291 error ("invalid use of pack expansion expression");
13292 return error_mark_node;
13294 case NONTYPE_ARGUMENT_PACK:
13295 error ("use %<...%> to expand argument pack");
13296 return error_mark_node;
13299 gcc_assert (!STATEMENT_CODE_P (TREE_CODE (t)));
13301 return tsubst_copy_and_build (t, args, complain, in_decl,
13302 /*function_p=*/false,
13303 integral_constant_expression_p);
13310 /* T is a postfix-expression that is not being used in a function
13311 call. Return the substituted version of T. */
13314 tsubst_non_call_postfix_expression (tree t, tree args,
13315 tsubst_flags_t complain,
13318 if (TREE_CODE (t) == SCOPE_REF)
13319 t = tsubst_qualified_id (t, args, complain, in_decl,
13320 /*done=*/false, /*address_p=*/false);
13322 t = tsubst_copy_and_build (t, args, complain, in_decl,
13323 /*function_p=*/false,
13324 /*integral_constant_expression_p=*/false);
13329 /* Like tsubst but deals with expressions and performs semantic
13330 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
13333 tsubst_copy_and_build (tree t,
13335 tsubst_flags_t complain,
13338 bool integral_constant_expression_p)
13340 #define RECUR(NODE) \
13341 tsubst_copy_and_build (NODE, args, complain, in_decl, \
13342 /*function_p=*/false, \
13343 integral_constant_expression_p)
13347 if (t == NULL_TREE || t == error_mark_node)
13350 switch (TREE_CODE (t))
13354 /* Fall through. */
13355 case IDENTIFIER_NODE:
13359 bool non_integral_constant_expression_p;
13360 const char *error_msg;
13362 if (IDENTIFIER_TYPENAME_P (t))
13364 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
13365 t = mangle_conv_op_name_for_type (new_type);
13368 /* Look up the name. */
13369 decl = lookup_name (t);
13371 /* By convention, expressions use ERROR_MARK_NODE to indicate
13372 failure, not NULL_TREE. */
13373 if (decl == NULL_TREE)
13374 decl = error_mark_node;
13376 decl = finish_id_expression (t, decl, NULL_TREE,
13378 integral_constant_expression_p,
13379 /*allow_non_integral_constant_expression_p=*/(cxx_dialect >= cxx0x),
13380 &non_integral_constant_expression_p,
13381 /*template_p=*/false,
13383 /*address_p=*/false,
13384 /*template_arg_p=*/false,
13389 if (!function_p && TREE_CODE (decl) == IDENTIFIER_NODE)
13391 if (complain & tf_error)
13392 unqualified_name_lookup_error (decl);
13393 decl = error_mark_node;
13398 case TEMPLATE_ID_EXPR:
13401 tree templ = RECUR (TREE_OPERAND (t, 0));
13402 tree targs = TREE_OPERAND (t, 1);
13405 targs = tsubst_template_args (targs, args, complain, in_decl);
13407 if (TREE_CODE (templ) == COMPONENT_REF)
13409 object = TREE_OPERAND (templ, 0);
13410 templ = TREE_OPERAND (templ, 1);
13413 object = NULL_TREE;
13414 templ = lookup_template_function (templ, targs);
13417 return build3 (COMPONENT_REF, TREE_TYPE (templ),
13418 object, templ, NULL_TREE);
13420 return baselink_for_fns (templ);
13425 tree r = RECUR (TREE_OPERAND (t, 0));
13427 if (REFERENCE_REF_P (t))
13429 /* A type conversion to reference type will be enclosed in
13430 such an indirect ref, but the substitution of the cast
13431 will have also added such an indirect ref. */
13432 if (TREE_CODE (TREE_TYPE (r)) == REFERENCE_TYPE)
13433 r = convert_from_reference (r);
13436 r = build_x_indirect_ref (r, RO_UNARY_STAR, complain);
13442 (tsubst (TREE_TYPE (t), args, complain, in_decl),
13443 RECUR (TREE_OPERAND (t, 0)));
13445 case IMPLICIT_CONV_EXPR:
13447 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
13448 tree expr = RECUR (TREE_OPERAND (t, 0));
13449 int flags = LOOKUP_IMPLICIT;
13450 if (IMPLICIT_CONV_EXPR_DIRECT_INIT (t))
13451 flags = LOOKUP_NORMAL;
13452 return perform_implicit_conversion_flags (type, expr, complain,
13459 tsubst (TREE_TYPE (t), args, complain, in_decl),
13460 RECUR (TREE_OPERAND (t, 0)));
13463 case REINTERPRET_CAST_EXPR:
13464 case CONST_CAST_EXPR:
13465 case DYNAMIC_CAST_EXPR:
13466 case STATIC_CAST_EXPR:
13471 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
13472 if (integral_constant_expression_p
13473 && !cast_valid_in_integral_constant_expression_p (type))
13475 if (complain & tf_error)
13476 error ("a cast to a type other than an integral or "
13477 "enumeration type cannot appear in a constant-expression");
13478 return error_mark_node;
13481 op = RECUR (TREE_OPERAND (t, 0));
13483 switch (TREE_CODE (t))
13486 return build_functional_cast (type, op, complain);
13487 case REINTERPRET_CAST_EXPR:
13488 return build_reinterpret_cast (type, op, complain);
13489 case CONST_CAST_EXPR:
13490 return build_const_cast (type, op, complain);
13491 case DYNAMIC_CAST_EXPR:
13492 return build_dynamic_cast (type, op, complain);
13493 case STATIC_CAST_EXPR:
13494 return build_static_cast (type, op, complain);
13496 gcc_unreachable ();
13500 case POSTDECREMENT_EXPR:
13501 case POSTINCREMENT_EXPR:
13502 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
13503 args, complain, in_decl);
13504 return build_x_unary_op (TREE_CODE (t), op1, complain);
13506 case PREDECREMENT_EXPR:
13507 case PREINCREMENT_EXPR:
13511 case TRUTH_NOT_EXPR:
13512 case UNARY_PLUS_EXPR: /* Unary + */
13513 case REALPART_EXPR:
13514 case IMAGPART_EXPR:
13515 return build_x_unary_op (TREE_CODE (t), RECUR (TREE_OPERAND (t, 0)),
13518 case FIX_TRUNC_EXPR:
13519 return cp_build_unary_op (FIX_TRUNC_EXPR, RECUR (TREE_OPERAND (t, 0)),
13523 op1 = TREE_OPERAND (t, 0);
13524 if (TREE_CODE (op1) == LABEL_DECL)
13525 return finish_label_address_expr (DECL_NAME (op1),
13526 EXPR_LOCATION (op1));
13527 if (TREE_CODE (op1) == SCOPE_REF)
13528 op1 = tsubst_qualified_id (op1, args, complain, in_decl,
13529 /*done=*/true, /*address_p=*/true);
13531 op1 = tsubst_non_call_postfix_expression (op1, args, complain,
13533 return build_x_unary_op (ADDR_EXPR, op1, complain);
13538 case TRUNC_DIV_EXPR:
13539 case CEIL_DIV_EXPR:
13540 case FLOOR_DIV_EXPR:
13541 case ROUND_DIV_EXPR:
13542 case EXACT_DIV_EXPR:
13546 case TRUNC_MOD_EXPR:
13547 case FLOOR_MOD_EXPR:
13548 case TRUTH_ANDIF_EXPR:
13549 case TRUTH_ORIF_EXPR:
13550 case TRUTH_AND_EXPR:
13551 case TRUTH_OR_EXPR:
13566 return build_x_binary_op
13568 RECUR (TREE_OPERAND (t, 0)),
13569 (TREE_NO_WARNING (TREE_OPERAND (t, 0))
13571 : TREE_CODE (TREE_OPERAND (t, 0))),
13572 RECUR (TREE_OPERAND (t, 1)),
13573 (TREE_NO_WARNING (TREE_OPERAND (t, 1))
13575 : TREE_CODE (TREE_OPERAND (t, 1))),
13580 return tsubst_qualified_id (t, args, complain, in_decl, /*done=*/true,
13581 /*address_p=*/false);
13583 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
13584 args, complain, in_decl);
13585 return build_x_array_ref (op1, RECUR (TREE_OPERAND (t, 1)), complain);
13588 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
13589 return tsubst_copy (t, args, complain, in_decl);
13593 op1 = TREE_OPERAND (t, 0);
13596 /* When there are no ARGS, we are trying to evaluate a
13597 non-dependent expression from the parser. Trying to do
13598 the substitutions may not work. */
13600 op1 = TREE_TYPE (op1);
13604 ++cp_unevaluated_operand;
13605 ++c_inhibit_evaluation_warnings;
13606 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
13607 /*function_p=*/false,
13608 /*integral_constant_expression_p=*/false);
13609 --cp_unevaluated_operand;
13610 --c_inhibit_evaluation_warnings;
13613 return cxx_sizeof_or_alignof_type (op1, TREE_CODE (t),
13614 complain & tf_error);
13616 return cxx_sizeof_or_alignof_expr (op1, TREE_CODE (t),
13617 complain & tf_error);
13619 case AT_ENCODE_EXPR:
13621 op1 = TREE_OPERAND (t, 0);
13622 ++cp_unevaluated_operand;
13623 ++c_inhibit_evaluation_warnings;
13624 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
13625 /*function_p=*/false,
13626 /*integral_constant_expression_p=*/false);
13627 --cp_unevaluated_operand;
13628 --c_inhibit_evaluation_warnings;
13629 return objc_build_encode_expr (op1);
13632 case NOEXCEPT_EXPR:
13633 op1 = TREE_OPERAND (t, 0);
13634 ++cp_unevaluated_operand;
13635 ++c_inhibit_evaluation_warnings;
13636 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
13637 /*function_p=*/false,
13638 /*integral_constant_expression_p=*/false);
13639 --cp_unevaluated_operand;
13640 --c_inhibit_evaluation_warnings;
13641 return finish_noexcept_expr (op1, complain);
13645 tree r = build_x_modify_expr
13646 (RECUR (TREE_OPERAND (t, 0)),
13647 TREE_CODE (TREE_OPERAND (t, 1)),
13648 RECUR (TREE_OPERAND (t, 2)),
13650 /* TREE_NO_WARNING must be set if either the expression was
13651 parenthesized or it uses an operator such as >>= rather
13652 than plain assignment. In the former case, it was already
13653 set and must be copied. In the latter case,
13654 build_x_modify_expr sets it and it must not be reset
13656 if (TREE_NO_WARNING (t))
13657 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
13662 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
13663 args, complain, in_decl);
13664 /* Remember that there was a reference to this entity. */
13667 return build_x_arrow (op1);
13671 tree placement = RECUR (TREE_OPERAND (t, 0));
13672 tree init = RECUR (TREE_OPERAND (t, 3));
13673 VEC(tree,gc) *placement_vec;
13674 VEC(tree,gc) *init_vec;
13677 if (placement == NULL_TREE)
13678 placement_vec = NULL;
13681 placement_vec = make_tree_vector ();
13682 for (; placement != NULL_TREE; placement = TREE_CHAIN (placement))
13683 VEC_safe_push (tree, gc, placement_vec, TREE_VALUE (placement));
13686 /* If there was an initializer in the original tree, but it
13687 instantiated to an empty list, then we should pass a
13688 non-NULL empty vector to tell build_new that it was an
13689 empty initializer() rather than no initializer. This can
13690 only happen when the initializer is a pack expansion whose
13691 parameter packs are of length zero. */
13692 if (init == NULL_TREE && TREE_OPERAND (t, 3) == NULL_TREE)
13696 init_vec = make_tree_vector ();
13697 if (init == void_zero_node)
13698 gcc_assert (init_vec != NULL);
13701 for (; init != NULL_TREE; init = TREE_CHAIN (init))
13702 VEC_safe_push (tree, gc, init_vec, TREE_VALUE (init));
13706 ret = build_new (&placement_vec,
13707 tsubst (TREE_OPERAND (t, 1), args, complain, in_decl),
13708 RECUR (TREE_OPERAND (t, 2)),
13710 NEW_EXPR_USE_GLOBAL (t),
13713 if (placement_vec != NULL)
13714 release_tree_vector (placement_vec);
13715 if (init_vec != NULL)
13716 release_tree_vector (init_vec);
13722 return delete_sanity
13723 (RECUR (TREE_OPERAND (t, 0)),
13724 RECUR (TREE_OPERAND (t, 1)),
13725 DELETE_EXPR_USE_VEC (t),
13726 DELETE_EXPR_USE_GLOBAL (t),
13729 case COMPOUND_EXPR:
13730 return build_x_compound_expr (RECUR (TREE_OPERAND (t, 0)),
13731 RECUR (TREE_OPERAND (t, 1)),
13737 VEC(tree,gc) *call_args;
13738 unsigned int nargs, i;
13743 function = CALL_EXPR_FN (t);
13744 /* When we parsed the expression, we determined whether or
13745 not Koenig lookup should be performed. */
13746 koenig_p = KOENIG_LOOKUP_P (t);
13747 if (TREE_CODE (function) == SCOPE_REF)
13749 qualified_p = true;
13750 function = tsubst_qualified_id (function, args, complain, in_decl,
13752 /*address_p=*/false);
13754 else if (koenig_p && TREE_CODE (function) == IDENTIFIER_NODE)
13756 /* Do nothing; calling tsubst_copy_and_build on an identifier
13757 would incorrectly perform unqualified lookup again.
13759 Note that we can also have an IDENTIFIER_NODE if the earlier
13760 unqualified lookup found a member function; in that case
13761 koenig_p will be false and we do want to do the lookup
13762 again to find the instantiated member function.
13764 FIXME but doing that causes c++/15272, so we need to stop
13765 using IDENTIFIER_NODE in that situation. */
13766 qualified_p = false;
13770 if (TREE_CODE (function) == COMPONENT_REF)
13772 tree op = TREE_OPERAND (function, 1);
13774 qualified_p = (TREE_CODE (op) == SCOPE_REF
13775 || (BASELINK_P (op)
13776 && BASELINK_QUALIFIED_P (op)));
13779 qualified_p = false;
13781 function = tsubst_copy_and_build (function, args, complain,
13784 integral_constant_expression_p);
13786 if (BASELINK_P (function))
13787 qualified_p = true;
13790 nargs = call_expr_nargs (t);
13791 call_args = make_tree_vector ();
13792 for (i = 0; i < nargs; ++i)
13794 tree arg = CALL_EXPR_ARG (t, i);
13796 if (!PACK_EXPANSION_P (arg))
13797 VEC_safe_push (tree, gc, call_args,
13798 RECUR (CALL_EXPR_ARG (t, i)));
13801 /* Expand the pack expansion and push each entry onto
13803 arg = tsubst_pack_expansion (arg, args, complain, in_decl);
13804 if (TREE_CODE (arg) == TREE_VEC)
13806 unsigned int len, j;
13808 len = TREE_VEC_LENGTH (arg);
13809 for (j = 0; j < len; ++j)
13811 tree value = TREE_VEC_ELT (arg, j);
13812 if (value != NULL_TREE)
13813 value = convert_from_reference (value);
13814 VEC_safe_push (tree, gc, call_args, value);
13819 /* A partial substitution. Add one entry. */
13820 VEC_safe_push (tree, gc, call_args, arg);
13825 /* We do not perform argument-dependent lookup if normal
13826 lookup finds a non-function, in accordance with the
13827 expected resolution of DR 218. */
13829 && ((is_overloaded_fn (function)
13830 /* If lookup found a member function, the Koenig lookup is
13831 not appropriate, even if an unqualified-name was used
13832 to denote the function. */
13833 && !DECL_FUNCTION_MEMBER_P (get_first_fn (function)))
13834 || TREE_CODE (function) == IDENTIFIER_NODE)
13835 /* Only do this when substitution turns a dependent call
13836 into a non-dependent call. */
13837 && type_dependent_expression_p_push (t)
13838 && !any_type_dependent_arguments_p (call_args))
13839 function = perform_koenig_lookup (function, call_args, false,
13842 if (TREE_CODE (function) == IDENTIFIER_NODE
13843 && !any_type_dependent_arguments_p (call_args))
13845 if (koenig_p && (complain & tf_warning_or_error))
13847 /* For backwards compatibility and good diagnostics, try
13848 the unqualified lookup again if we aren't in SFINAE
13850 tree unq = (tsubst_copy_and_build
13851 (function, args, complain, in_decl, true,
13852 integral_constant_expression_p));
13853 if (unq == error_mark_node)
13854 return error_mark_node;
13856 if (unq != function)
13859 if (TREE_CODE (fn) == INDIRECT_REF)
13860 fn = TREE_OPERAND (fn, 0);
13861 if (TREE_CODE (fn) == COMPONENT_REF)
13862 fn = TREE_OPERAND (fn, 1);
13863 if (is_overloaded_fn (fn))
13864 fn = get_first_fn (fn);
13865 permerror (EXPR_LOC_OR_HERE (t),
13866 "%qD was not declared in this scope, "
13867 "and no declarations were found by "
13868 "argument-dependent lookup at the point "
13869 "of instantiation", function);
13871 /* Can't say anything more. */;
13872 else if (DECL_CLASS_SCOPE_P (fn))
13874 inform (EXPR_LOC_OR_HERE (t),
13875 "declarations in dependent base %qT are "
13876 "not found by unqualified lookup",
13877 DECL_CLASS_CONTEXT (fn));
13878 if (current_class_ptr)
13879 inform (EXPR_LOC_OR_HERE (t),
13880 "use %<this->%D%> instead", function);
13882 inform (EXPR_LOC_OR_HERE (t),
13883 "use %<%T::%D%> instead",
13884 current_class_name, function);
13887 inform (0, "%q+D declared here, later in the "
13888 "translation unit", fn);
13892 if (TREE_CODE (function) == IDENTIFIER_NODE)
13894 unqualified_name_lookup_error (function);
13895 release_tree_vector (call_args);
13896 return error_mark_node;
13900 /* Remember that there was a reference to this entity. */
13901 if (DECL_P (function))
13902 mark_used (function);
13904 if (TREE_CODE (function) == OFFSET_REF)
13905 ret = build_offset_ref_call_from_tree (function, &call_args);
13906 else if (TREE_CODE (function) == COMPONENT_REF)
13908 tree instance = TREE_OPERAND (function, 0);
13909 tree fn = TREE_OPERAND (function, 1);
13911 if (processing_template_decl
13912 && (type_dependent_expression_p (instance)
13913 || (!BASELINK_P (fn)
13914 && TREE_CODE (fn) != FIELD_DECL)
13915 || type_dependent_expression_p (fn)
13916 || any_type_dependent_arguments_p (call_args)))
13917 ret = build_nt_call_vec (function, call_args);
13918 else if (!BASELINK_P (fn))
13919 ret = finish_call_expr (function, &call_args,
13920 /*disallow_virtual=*/false,
13921 /*koenig_p=*/false,
13924 ret = (build_new_method_call
13926 &call_args, NULL_TREE,
13927 qualified_p ? LOOKUP_NONVIRTUAL : LOOKUP_NORMAL,
13932 ret = finish_call_expr (function, &call_args,
13933 /*disallow_virtual=*/qualified_p,
13937 release_tree_vector (call_args);
13943 return build_x_conditional_expr
13944 (RECUR (TREE_OPERAND (t, 0)),
13945 RECUR (TREE_OPERAND (t, 1)),
13946 RECUR (TREE_OPERAND (t, 2)),
13949 case PSEUDO_DTOR_EXPR:
13950 return finish_pseudo_destructor_expr
13951 (RECUR (TREE_OPERAND (t, 0)),
13952 RECUR (TREE_OPERAND (t, 1)),
13953 tsubst (TREE_OPERAND (t, 2), args, complain, in_decl));
13957 tree purpose, value, chain;
13959 if (t == void_list_node)
13962 if ((TREE_PURPOSE (t) && PACK_EXPANSION_P (TREE_PURPOSE (t)))
13963 || (TREE_VALUE (t) && PACK_EXPANSION_P (TREE_VALUE (t))))
13965 /* We have pack expansions, so expand those and
13966 create a new list out of it. */
13967 tree purposevec = NULL_TREE;
13968 tree valuevec = NULL_TREE;
13972 /* Expand the argument expressions. */
13973 if (TREE_PURPOSE (t))
13974 purposevec = tsubst_pack_expansion (TREE_PURPOSE (t), args,
13975 complain, in_decl);
13976 if (TREE_VALUE (t))
13977 valuevec = tsubst_pack_expansion (TREE_VALUE (t), args,
13978 complain, in_decl);
13980 /* Build the rest of the list. */
13981 chain = TREE_CHAIN (t);
13982 if (chain && chain != void_type_node)
13983 chain = RECUR (chain);
13985 /* Determine the number of arguments. */
13986 if (purposevec && TREE_CODE (purposevec) == TREE_VEC)
13988 len = TREE_VEC_LENGTH (purposevec);
13989 gcc_assert (!valuevec || len == TREE_VEC_LENGTH (valuevec));
13991 else if (TREE_CODE (valuevec) == TREE_VEC)
13992 len = TREE_VEC_LENGTH (valuevec);
13995 /* Since we only performed a partial substitution into
13996 the argument pack, we only return a single list
13998 if (purposevec == TREE_PURPOSE (t)
13999 && valuevec == TREE_VALUE (t)
14000 && chain == TREE_CHAIN (t))
14003 return tree_cons (purposevec, valuevec, chain);
14006 /* Convert the argument vectors into a TREE_LIST */
14010 /* Grab the Ith values. */
14012 purpose = purposevec ? TREE_VEC_ELT (purposevec, i)
14015 = valuevec ? convert_from_reference (TREE_VEC_ELT (valuevec, i))
14018 /* Build the list (backwards). */
14019 chain = tree_cons (purpose, value, chain);
14025 purpose = TREE_PURPOSE (t);
14027 purpose = RECUR (purpose);
14028 value = TREE_VALUE (t);
14030 value = RECUR (value);
14031 chain = TREE_CHAIN (t);
14032 if (chain && chain != void_type_node)
14033 chain = RECUR (chain);
14034 if (purpose == TREE_PURPOSE (t)
14035 && value == TREE_VALUE (t)
14036 && chain == TREE_CHAIN (t))
14038 return tree_cons (purpose, value, chain);
14041 case COMPONENT_REF:
14047 object = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
14048 args, complain, in_decl);
14049 /* Remember that there was a reference to this entity. */
14050 if (DECL_P (object))
14051 mark_used (object);
14052 object_type = TREE_TYPE (object);
14054 member = TREE_OPERAND (t, 1);
14055 if (BASELINK_P (member))
14056 member = tsubst_baselink (member,
14057 non_reference (TREE_TYPE (object)),
14058 args, complain, in_decl);
14060 member = tsubst_copy (member, args, complain, in_decl);
14061 if (member == error_mark_node)
14062 return error_mark_node;
14064 if (type_dependent_expression_p (object))
14065 /* We can't do much here. */;
14066 else if (!CLASS_TYPE_P (object_type))
14068 if (SCALAR_TYPE_P (object_type))
14070 tree s = NULL_TREE;
14071 tree dtor = member;
14073 if (TREE_CODE (dtor) == SCOPE_REF)
14075 s = TREE_OPERAND (dtor, 0);
14076 dtor = TREE_OPERAND (dtor, 1);
14078 if (TREE_CODE (dtor) == BIT_NOT_EXPR)
14080 dtor = TREE_OPERAND (dtor, 0);
14082 return finish_pseudo_destructor_expr (object, s, dtor);
14086 else if (TREE_CODE (member) == SCOPE_REF
14087 && TREE_CODE (TREE_OPERAND (member, 1)) == TEMPLATE_ID_EXPR)
14089 /* Lookup the template functions now that we know what the
14091 tree scope = TREE_OPERAND (member, 0);
14092 tree tmpl = TREE_OPERAND (TREE_OPERAND (member, 1), 0);
14093 tree args = TREE_OPERAND (TREE_OPERAND (member, 1), 1);
14094 member = lookup_qualified_name (scope, tmpl,
14095 /*is_type_p=*/false,
14096 /*complain=*/false);
14097 if (BASELINK_P (member))
14099 BASELINK_FUNCTIONS (member)
14100 = build_nt (TEMPLATE_ID_EXPR, BASELINK_FUNCTIONS (member),
14102 member = (adjust_result_of_qualified_name_lookup
14103 (member, BINFO_TYPE (BASELINK_BINFO (member)),
14108 qualified_name_lookup_error (scope, tmpl, member,
14110 return error_mark_node;
14113 else if (TREE_CODE (member) == SCOPE_REF
14114 && !CLASS_TYPE_P (TREE_OPERAND (member, 0))
14115 && TREE_CODE (TREE_OPERAND (member, 0)) != NAMESPACE_DECL)
14117 if (complain & tf_error)
14119 if (TYPE_P (TREE_OPERAND (member, 0)))
14120 error ("%qT is not a class or namespace",
14121 TREE_OPERAND (member, 0));
14123 error ("%qD is not a class or namespace",
14124 TREE_OPERAND (member, 0));
14126 return error_mark_node;
14128 else if (TREE_CODE (member) == FIELD_DECL)
14129 return finish_non_static_data_member (member, object, NULL_TREE);
14131 return finish_class_member_access_expr (object, member,
14132 /*template_p=*/false,
14138 (RECUR (TREE_OPERAND (t, 0)));
14142 VEC(constructor_elt,gc) *n;
14143 constructor_elt *ce;
14144 unsigned HOST_WIDE_INT idx;
14145 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
14146 bool process_index_p;
14148 bool need_copy_p = false;
14151 if (type == error_mark_node)
14152 return error_mark_node;
14154 /* digest_init will do the wrong thing if we let it. */
14155 if (type && TYPE_PTRMEMFUNC_P (type))
14158 /* We do not want to process the index of aggregate
14159 initializers as they are identifier nodes which will be
14160 looked up by digest_init. */
14161 process_index_p = !(type && MAYBE_CLASS_TYPE_P (type));
14163 n = VEC_copy (constructor_elt, gc, CONSTRUCTOR_ELTS (t));
14164 newlen = VEC_length (constructor_elt, n);
14165 FOR_EACH_VEC_ELT (constructor_elt, n, idx, ce)
14167 if (ce->index && process_index_p)
14168 ce->index = RECUR (ce->index);
14170 if (PACK_EXPANSION_P (ce->value))
14172 /* Substitute into the pack expansion. */
14173 ce->value = tsubst_pack_expansion (ce->value, args, complain,
14176 if (ce->value == error_mark_node
14177 || PACK_EXPANSION_P (ce->value))
14179 else if (TREE_VEC_LENGTH (ce->value) == 1)
14180 /* Just move the argument into place. */
14181 ce->value = TREE_VEC_ELT (ce->value, 0);
14184 /* Update the length of the final CONSTRUCTOR
14185 arguments vector, and note that we will need to
14187 newlen = newlen + TREE_VEC_LENGTH (ce->value) - 1;
14188 need_copy_p = true;
14192 ce->value = RECUR (ce->value);
14197 VEC(constructor_elt,gc) *old_n = n;
14199 n = VEC_alloc (constructor_elt, gc, newlen);
14200 FOR_EACH_VEC_ELT (constructor_elt, old_n, idx, ce)
14202 if (TREE_CODE (ce->value) == TREE_VEC)
14204 int i, len = TREE_VEC_LENGTH (ce->value);
14205 for (i = 0; i < len; ++i)
14206 CONSTRUCTOR_APPEND_ELT (n, 0,
14207 TREE_VEC_ELT (ce->value, i));
14210 CONSTRUCTOR_APPEND_ELT (n, 0, ce->value);
14214 r = build_constructor (init_list_type_node, n);
14215 CONSTRUCTOR_IS_DIRECT_INIT (r) = CONSTRUCTOR_IS_DIRECT_INIT (t);
14217 if (TREE_HAS_CONSTRUCTOR (t))
14218 return finish_compound_literal (type, r, complain);
14220 TREE_TYPE (r) = type;
14226 tree operand_0 = TREE_OPERAND (t, 0);
14227 if (TYPE_P (operand_0))
14229 operand_0 = tsubst (operand_0, args, complain, in_decl);
14230 return get_typeid (operand_0);
14234 operand_0 = RECUR (operand_0);
14235 return build_typeid (operand_0);
14246 tree r = tsubst_copy (t, args, complain, in_decl);
14248 if (TREE_CODE (TREE_TYPE (t)) != REFERENCE_TYPE)
14249 /* If the original type was a reference, we'll be wrapped in
14250 the appropriate INDIRECT_REF. */
14251 r = convert_from_reference (r);
14256 return build_x_va_arg (RECUR (TREE_OPERAND (t, 0)),
14257 tsubst (TREE_TYPE (t), args, complain, in_decl));
14259 case OFFSETOF_EXPR:
14260 return finish_offsetof (RECUR (TREE_OPERAND (t, 0)));
14264 tree type1 = tsubst_copy (TRAIT_EXPR_TYPE1 (t), args,
14265 complain, in_decl);
14267 tree type2 = TRAIT_EXPR_TYPE2 (t);
14269 type2 = tsubst_copy (type2, args, complain, in_decl);
14271 return finish_trait_expr (TRAIT_EXPR_KIND (t), type1, type2);
14276 tree old_stmt_expr = cur_stmt_expr;
14277 tree stmt_expr = begin_stmt_expr ();
14279 cur_stmt_expr = stmt_expr;
14280 tsubst_expr (STMT_EXPR_STMT (t), args, complain, in_decl,
14281 integral_constant_expression_p);
14282 stmt_expr = finish_stmt_expr (stmt_expr, false);
14283 cur_stmt_expr = old_stmt_expr;
14285 /* If the resulting list of expression statement is empty,
14286 fold it further into void_zero_node. */
14287 if (empty_expr_stmt_p (stmt_expr))
14288 stmt_expr = void_zero_node;
14294 t = tsubst_copy (t, args, complain, in_decl);
14295 /* As in finish_id_expression, we resolve enumeration constants
14296 to their underlying values. */
14297 if (TREE_CODE (t) == CONST_DECL && !processing_template_decl)
14299 used_types_insert (TREE_TYPE (t));
14300 return DECL_INITIAL (t);
14306 tree r = build_lambda_expr ();
14308 tree type = tsubst (LAMBDA_EXPR_CLOSURE (t), args, complain, NULL_TREE);
14309 LAMBDA_EXPR_CLOSURE (r) = type;
14310 CLASSTYPE_LAMBDA_EXPR (type) = r;
14312 LAMBDA_EXPR_LOCATION (r)
14313 = LAMBDA_EXPR_LOCATION (t);
14314 LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (r)
14315 = LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (t);
14316 LAMBDA_EXPR_MUTABLE_P (r) = LAMBDA_EXPR_MUTABLE_P (t);
14317 LAMBDA_EXPR_DISCRIMINATOR (r)
14318 = (LAMBDA_EXPR_DISCRIMINATOR (t));
14319 LAMBDA_EXPR_EXTRA_SCOPE (r)
14320 = RECUR (LAMBDA_EXPR_EXTRA_SCOPE (t));
14321 if (LAMBDA_EXPR_RETURN_TYPE (t) == dependent_lambda_return_type_node)
14323 LAMBDA_EXPR_RETURN_TYPE (r) = dependent_lambda_return_type_node;
14324 LAMBDA_EXPR_DEDUCE_RETURN_TYPE_P (r) = true;
14327 LAMBDA_EXPR_RETURN_TYPE (r)
14328 = tsubst (LAMBDA_EXPR_RETURN_TYPE (t), args, complain, in_decl);
14330 gcc_assert (LAMBDA_EXPR_THIS_CAPTURE (t) == NULL_TREE
14331 && LAMBDA_EXPR_PENDING_PROXIES (t) == NULL);
14333 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
14334 determine_visibility (TYPE_NAME (type));
14335 /* Now that we know visibility, instantiate the type so we have a
14336 declaration of the op() for later calls to lambda_function. */
14337 complete_type (type);
14339 /* The capture list refers to closure members, so this needs to
14340 wait until after we finish instantiating the type. */
14341 LAMBDA_EXPR_CAPTURE_LIST (r)
14342 = RECUR (LAMBDA_EXPR_CAPTURE_LIST (t));
14344 return build_lambda_object (r);
14348 /* We can get here for a constant initializer of non-dependent type.
14349 FIXME stop folding in cp_parser_initializer_clause. */
14350 gcc_assert (TREE_CONSTANT (t));
14352 tree r = get_target_expr (RECUR (TARGET_EXPR_INITIAL (t)));
14353 TREE_CONSTANT (r) = true;
14357 case TRANSACTION_EXPR:
14358 return tsubst_expr(t, args, complain, in_decl,
14359 integral_constant_expression_p);
14362 /* Handle Objective-C++ constructs, if appropriate. */
14365 = objcp_tsubst_copy_and_build (t, args, complain,
14366 in_decl, /*function_p=*/false);
14370 return tsubst_copy (t, args, complain, in_decl);
14376 /* Verify that the instantiated ARGS are valid. For type arguments,
14377 make sure that the type's linkage is ok. For non-type arguments,
14378 make sure they are constants if they are integral or enumerations.
14379 Emit an error under control of COMPLAIN, and return TRUE on error. */
14382 check_instantiated_arg (tree tmpl, tree t, tsubst_flags_t complain)
14384 if (ARGUMENT_PACK_P (t))
14386 tree vec = ARGUMENT_PACK_ARGS (t);
14387 int len = TREE_VEC_LENGTH (vec);
14388 bool result = false;
14391 for (i = 0; i < len; ++i)
14392 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (vec, i), complain))
14396 else if (TYPE_P (t))
14398 /* [basic.link]: A name with no linkage (notably, the name
14399 of a class or enumeration declared in a local scope)
14400 shall not be used to declare an entity with linkage.
14401 This implies that names with no linkage cannot be used as
14404 DR 757 relaxes this restriction for C++0x. */
14405 tree nt = (cxx_dialect > cxx98 ? NULL_TREE
14406 : no_linkage_check (t, /*relaxed_p=*/false));
14410 /* DR 488 makes use of a type with no linkage cause
14411 type deduction to fail. */
14412 if (complain & tf_error)
14414 if (TYPE_ANONYMOUS_P (nt))
14415 error ("%qT is/uses anonymous type", t);
14417 error ("template argument for %qD uses local type %qT",
14422 /* In order to avoid all sorts of complications, we do not
14423 allow variably-modified types as template arguments. */
14424 else if (variably_modified_type_p (t, NULL_TREE))
14426 if (complain & tf_error)
14427 error ("%qT is a variably modified type", t);
14431 /* A non-type argument of integral or enumerated type must be a
14433 else if (TREE_TYPE (t)
14434 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t))
14435 && !TREE_CONSTANT (t))
14437 if (complain & tf_error)
14438 error ("integral expression %qE is not constant", t);
14445 check_instantiated_args (tree tmpl, tree args, tsubst_flags_t complain)
14447 int ix, len = DECL_NTPARMS (tmpl);
14448 bool result = false;
14450 for (ix = 0; ix != len; ix++)
14452 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (args, ix), complain))
14455 if (result && (complain & tf_error))
14456 error (" trying to instantiate %qD", tmpl);
14460 /* In C++0x, it's possible to have a function template whose type depends
14461 on itself recursively. This is most obvious with decltype, but can also
14462 occur with enumeration scope (c++/48969). So we need to catch infinite
14463 recursion and reject the substitution at deduction time; this function
14464 will return error_mark_node for any repeated substitution.
14466 This also catches excessive recursion such as when f<N> depends on
14467 f<N-1> across all integers, and returns error_mark_node for all the
14468 substitutions back up to the initial one.
14470 This is, of course, not reentrant. */
14473 deduction_tsubst_fntype (tree fn, tree targs, tsubst_flags_t complain)
14475 static bool excessive_deduction_depth;
14476 static int deduction_depth;
14477 struct pending_template *old_last_pend = last_pending_template;
14478 struct tinst_level *old_error_tinst = last_error_tinst_level;
14480 tree fntype = TREE_TYPE (fn);
14484 if (excessive_deduction_depth)
14485 return error_mark_node;
14487 tinst = build_tree_list (fn, targs);
14488 if (!push_tinst_level (tinst))
14490 excessive_deduction_depth = true;
14492 return error_mark_node;
14495 input_location = DECL_SOURCE_LOCATION (fn);
14497 push_deduction_access_scope (fn);
14498 r = tsubst (fntype, targs, complain, NULL_TREE);
14499 pop_deduction_access_scope (fn);
14502 if (excessive_deduction_depth)
14504 r = error_mark_node;
14505 if (deduction_depth == 0)
14506 /* Reset once we're all the way out. */
14507 excessive_deduction_depth = false;
14510 pop_tinst_level ();
14511 /* We can't free this if a pending_template entry or last_error_tinst_level
14512 is pointing at it. */
14513 if (last_pending_template == old_last_pend
14514 && last_error_tinst_level == old_error_tinst)
14519 /* Instantiate the indicated variable or function template TMPL with
14520 the template arguments in TARG_PTR. */
14523 instantiate_template_1 (tree tmpl, tree orig_args, tsubst_flags_t complain)
14525 tree targ_ptr = orig_args;
14530 if (tmpl == error_mark_node)
14531 return error_mark_node;
14533 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
14535 /* If this function is a clone, handle it specially. */
14536 if (DECL_CLONED_FUNCTION_P (tmpl))
14541 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
14542 DECL_CLONED_FUNCTION. */
14543 spec = instantiate_template (DECL_ABSTRACT_ORIGIN (tmpl),
14544 targ_ptr, complain);
14545 if (spec == error_mark_node)
14546 return error_mark_node;
14548 /* Look for the clone. */
14549 FOR_EACH_CLONE (clone, spec)
14550 if (DECL_NAME (clone) == DECL_NAME (tmpl))
14552 /* We should always have found the clone by now. */
14553 gcc_unreachable ();
14557 /* Check to see if we already have this specialization. */
14558 gen_tmpl = most_general_template (tmpl);
14559 if (tmpl != gen_tmpl)
14560 /* The TMPL is a partial instantiation. To get a full set of
14561 arguments we must add the arguments used to perform the
14562 partial instantiation. */
14563 targ_ptr = add_outermost_template_args (DECL_TI_ARGS (tmpl),
14566 /* It would be nice to avoid hashing here and then again in tsubst_decl,
14567 but it doesn't seem to be on the hot path. */
14568 spec = retrieve_specialization (gen_tmpl, targ_ptr, 0);
14570 gcc_assert (tmpl == gen_tmpl
14571 || ((fndecl = retrieve_specialization (tmpl, orig_args, 0))
14573 || fndecl == NULL_TREE);
14575 if (spec != NULL_TREE)
14578 if (check_instantiated_args (gen_tmpl, INNERMOST_TEMPLATE_ARGS (targ_ptr),
14580 return error_mark_node;
14582 /* We are building a FUNCTION_DECL, during which the access of its
14583 parameters and return types have to be checked. However this
14584 FUNCTION_DECL which is the desired context for access checking
14585 is not built yet. We solve this chicken-and-egg problem by
14586 deferring all checks until we have the FUNCTION_DECL. */
14587 push_deferring_access_checks (dk_deferred);
14589 /* Instantiation of the function happens in the context of the function
14590 template, not the context of the overload resolution we're doing. */
14591 push_to_top_level ();
14592 if (DECL_CLASS_SCOPE_P (gen_tmpl))
14594 tree ctx = tsubst (DECL_CONTEXT (gen_tmpl), targ_ptr,
14595 complain, gen_tmpl);
14596 push_nested_class (ctx);
14598 /* Substitute template parameters to obtain the specialization. */
14599 fndecl = tsubst (DECL_TEMPLATE_RESULT (gen_tmpl),
14600 targ_ptr, complain, gen_tmpl);
14601 if (DECL_CLASS_SCOPE_P (gen_tmpl))
14602 pop_nested_class ();
14603 pop_from_top_level ();
14605 if (fndecl == error_mark_node)
14606 return error_mark_node;
14608 /* Now we know the specialization, compute access previously
14610 push_access_scope (fndecl);
14612 /* Some typedefs referenced from within the template code need to be access
14613 checked at template instantiation time, i.e now. These types were
14614 added to the template at parsing time. Let's get those and perfom
14615 the acces checks then. */
14616 perform_typedefs_access_check (DECL_TEMPLATE_RESULT (tmpl), targ_ptr);
14617 perform_deferred_access_checks ();
14618 pop_access_scope (fndecl);
14619 pop_deferring_access_checks ();
14621 /* The DECL_TI_TEMPLATE should always be the immediate parent
14622 template, not the most general template. */
14623 DECL_TI_TEMPLATE (fndecl) = tmpl;
14625 /* If we've just instantiated the main entry point for a function,
14626 instantiate all the alternate entry points as well. We do this
14627 by cloning the instantiation of the main entry point, not by
14628 instantiating the template clones. */
14629 if (DECL_CHAIN (gen_tmpl) && DECL_CLONED_FUNCTION_P (DECL_CHAIN (gen_tmpl)))
14630 clone_function_decl (fndecl, /*update_method_vec_p=*/0);
14635 /* Wrapper for instantiate_template_1. */
14638 instantiate_template (tree tmpl, tree orig_args, tsubst_flags_t complain)
14641 timevar_push (TV_TEMPLATE_INST);
14642 ret = instantiate_template_1 (tmpl, orig_args, complain);
14643 timevar_pop (TV_TEMPLATE_INST);
14647 /* We're going to do deduction substitution on the type of TMPL, a function
14648 template. In C++11 mode, push into that access scope. In C++03 mode,
14649 disable access checking. */
14652 push_deduction_access_scope (tree tmpl)
14654 if (cxx_dialect >= cxx0x)
14656 int ptd = processing_template_decl;
14657 push_access_scope (DECL_TEMPLATE_RESULT (tmpl));
14658 /* Preserve processing_template_decl across push_to_top_level. */
14659 if (ptd && !processing_template_decl)
14660 ++processing_template_decl;
14663 push_deferring_access_checks (dk_no_check);
14666 /* And pop back out. */
14669 pop_deduction_access_scope (tree tmpl)
14671 if (cxx_dialect >= cxx0x)
14672 pop_access_scope (DECL_TEMPLATE_RESULT (tmpl));
14674 pop_deferring_access_checks ();
14677 /* PARM is a template parameter pack for FN. Returns true iff
14678 PARM is used in a deducible way in the argument list of FN. */
14681 pack_deducible_p (tree parm, tree fn)
14683 tree t = FUNCTION_FIRST_USER_PARMTYPE (fn);
14684 for (; t; t = TREE_CHAIN (t))
14686 tree type = TREE_VALUE (t);
14688 if (!PACK_EXPANSION_P (type))
14690 for (packs = PACK_EXPANSION_PARAMETER_PACKS (type);
14691 packs; packs = TREE_CHAIN (packs))
14692 if (TREE_VALUE (packs) == parm)
14694 /* The template parameter pack is used in a function parameter
14695 pack. If this is the end of the parameter list, the
14696 template parameter pack is deducible. */
14697 if (TREE_CHAIN (t) == void_list_node)
14700 /* Otherwise, not. Well, it could be deduced from
14701 a non-pack parameter, but doing so would end up with
14702 a deduction mismatch, so don't bother. */
14706 /* The template parameter pack isn't used in any function parameter
14707 packs, but it might be used deeper, e.g. tuple<Args...>. */
14711 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
14712 NARGS elements of the arguments that are being used when calling
14713 it. TARGS is a vector into which the deduced template arguments
14716 Return zero for success, 2 for an incomplete match that doesn't resolve
14717 all the types, and 1 for complete failure. An error message will be
14718 printed only for an incomplete match.
14720 If FN is a conversion operator, or we are trying to produce a specific
14721 specialization, RETURN_TYPE is the return type desired.
14723 The EXPLICIT_TARGS are explicit template arguments provided via a
14726 The parameter STRICT is one of:
14729 We are deducing arguments for a function call, as in
14730 [temp.deduct.call].
14733 We are deducing arguments for a conversion function, as in
14734 [temp.deduct.conv].
14737 We are deducing arguments when doing an explicit instantiation
14738 as in [temp.explicit], when determining an explicit specialization
14739 as in [temp.expl.spec], or when taking the address of a function
14740 template, as in [temp.deduct.funcaddr]. */
14743 fn_type_unification (tree fn,
14744 tree explicit_targs,
14747 unsigned int nargs,
14749 unification_kind_t strict,
14757 gcc_assert (TREE_CODE (fn) == TEMPLATE_DECL);
14759 fntype = TREE_TYPE (fn);
14760 if (explicit_targs)
14764 The specified template arguments must match the template
14765 parameters in kind (i.e., type, nontype, template), and there
14766 must not be more arguments than there are parameters;
14767 otherwise type deduction fails.
14769 Nontype arguments must match the types of the corresponding
14770 nontype template parameters, or must be convertible to the
14771 types of the corresponding nontype parameters as specified in
14772 _temp.arg.nontype_, otherwise type deduction fails.
14774 All references in the function type of the function template
14775 to the corresponding template parameters are replaced by the
14776 specified template argument values. If a substitution in a
14777 template parameter or in the function type of the function
14778 template results in an invalid type, type deduction fails. */
14779 tree tparms = DECL_INNERMOST_TEMPLATE_PARMS (fn);
14780 int i, len = TREE_VEC_LENGTH (tparms);
14781 tree converted_args;
14782 bool incomplete = false;
14784 if (explicit_targs == error_mark_node)
14785 return unify_invalid (explain_p);
14788 = (coerce_template_parms (tparms, explicit_targs, NULL_TREE,
14790 ? tf_warning_or_error
14792 /*require_all_args=*/false,
14793 /*use_default_args=*/false));
14794 if (converted_args == error_mark_node)
14797 /* Substitute the explicit args into the function type. This is
14798 necessary so that, for instance, explicitly declared function
14799 arguments can match null pointed constants. If we were given
14800 an incomplete set of explicit args, we must not do semantic
14801 processing during substitution as we could create partial
14803 for (i = 0; i < len; i++)
14805 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
14806 bool parameter_pack = false;
14807 tree targ = TREE_VEC_ELT (converted_args, i);
14809 /* Dig out the actual parm. */
14810 if (TREE_CODE (parm) == TYPE_DECL
14811 || TREE_CODE (parm) == TEMPLATE_DECL)
14813 parm = TREE_TYPE (parm);
14814 parameter_pack = TEMPLATE_TYPE_PARAMETER_PACK (parm);
14816 else if (TREE_CODE (parm) == PARM_DECL)
14818 parm = DECL_INITIAL (parm);
14819 parameter_pack = TEMPLATE_PARM_PARAMETER_PACK (parm);
14822 if (!parameter_pack && targ == NULL_TREE)
14823 /* No explicit argument for this template parameter. */
14826 if (parameter_pack && pack_deducible_p (parm, fn))
14828 /* Mark the argument pack as "incomplete". We could
14829 still deduce more arguments during unification.
14830 We remove this mark in type_unification_real. */
14833 ARGUMENT_PACK_INCOMPLETE_P(targ) = 1;
14834 ARGUMENT_PACK_EXPLICIT_ARGS (targ)
14835 = ARGUMENT_PACK_ARGS (targ);
14838 /* We have some incomplete argument packs. */
14843 processing_template_decl += incomplete;
14844 fntype = deduction_tsubst_fntype (fn, converted_args,
14846 ? tf_warning_or_error
14848 processing_template_decl -= incomplete;
14850 if (fntype == error_mark_node)
14853 /* Place the explicitly specified arguments in TARGS. */
14854 for (i = NUM_TMPL_ARGS (converted_args); i--;)
14855 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (converted_args, i);
14858 /* Never do unification on the 'this' parameter. */
14859 parms = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (fntype));
14865 parms = tree_cons (NULL_TREE, TREE_TYPE (fntype), parms);
14866 new_args = XALLOCAVEC (tree, nargs + 1);
14867 new_args[0] = return_type;
14868 memcpy (new_args + 1, args, nargs * sizeof (tree));
14873 /* We allow incomplete unification without an error message here
14874 because the standard doesn't seem to explicitly prohibit it. Our
14875 callers must be ready to deal with unification failures in any
14877 result = type_unification_real (DECL_INNERMOST_TEMPLATE_PARMS (fn),
14878 targs, parms, args, nargs, /*subr=*/0,
14879 strict, flags, explain_p);
14881 /* Now that we have bindings for all of the template arguments,
14882 ensure that the arguments deduced for the template template
14883 parameters have compatible template parameter lists. We cannot
14884 check this property before we have deduced all template
14885 arguments, because the template parameter types of a template
14886 template parameter might depend on prior template parameters
14887 deduced after the template template parameter. The following
14888 ill-formed example illustrates this issue:
14890 template<typename T, template<T> class C> void f(C<5>, T);
14892 template<int N> struct X {};
14895 f(X<5>(), 5l); // error: template argument deduction fails
14898 The template parameter list of 'C' depends on the template type
14899 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
14900 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
14901 time that we deduce 'C'. */
14903 && !template_template_parm_bindings_ok_p
14904 (DECL_INNERMOST_TEMPLATE_PARMS (fn), targs))
14905 return unify_inconsistent_template_template_parameters (explain_p);
14908 /* All is well so far. Now, check:
14912 When all template arguments have been deduced, all uses of
14913 template parameters in nondeduced contexts are replaced with
14914 the corresponding deduced argument values. If the
14915 substitution results in an invalid type, as described above,
14916 type deduction fails. */
14918 tree substed = deduction_tsubst_fntype (fn, targs,
14920 ? tf_warning_or_error
14922 if (substed == error_mark_node)
14925 /* If we're looking for an exact match, check that what we got
14926 is indeed an exact match. It might not be if some template
14927 parameters are used in non-deduced contexts. */
14928 if (strict == DEDUCE_EXACT)
14933 = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (substed));
14935 sarg = tree_cons (NULL_TREE, TREE_TYPE (substed), sarg);
14936 for (i = 0; i < nargs && sarg; ++i, sarg = TREE_CHAIN (sarg))
14937 if (!same_type_p (args[i], TREE_VALUE (sarg)))
14938 return unify_type_mismatch (explain_p, args[i],
14939 TREE_VALUE (sarg));
14946 /* Adjust types before performing type deduction, as described in
14947 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
14948 sections are symmetric. PARM is the type of a function parameter
14949 or the return type of the conversion function. ARG is the type of
14950 the argument passed to the call, or the type of the value
14951 initialized with the result of the conversion function.
14952 ARG_EXPR is the original argument expression, which may be null. */
14955 maybe_adjust_types_for_deduction (unification_kind_t strict,
14969 /* Swap PARM and ARG throughout the remainder of this
14970 function; the handling is precisely symmetric since PARM
14971 will initialize ARG rather than vice versa. */
14979 /* Core issue #873: Do the DR606 thing (see below) for these cases,
14980 too, but here handle it by stripping the reference from PARM
14981 rather than by adding it to ARG. */
14982 if (TREE_CODE (*parm) == REFERENCE_TYPE
14983 && TYPE_REF_IS_RVALUE (*parm)
14984 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
14985 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
14986 && TREE_CODE (*arg) == REFERENCE_TYPE
14987 && !TYPE_REF_IS_RVALUE (*arg))
14988 *parm = TREE_TYPE (*parm);
14989 /* Nothing else to do in this case. */
14993 gcc_unreachable ();
14996 if (TREE_CODE (*parm) != REFERENCE_TYPE)
14998 /* [temp.deduct.call]
15000 If P is not a reference type:
15002 --If A is an array type, the pointer type produced by the
15003 array-to-pointer standard conversion (_conv.array_) is
15004 used in place of A for type deduction; otherwise,
15006 --If A is a function type, the pointer type produced by
15007 the function-to-pointer standard conversion
15008 (_conv.func_) is used in place of A for type deduction;
15011 --If A is a cv-qualified type, the top level
15012 cv-qualifiers of A's type are ignored for type
15014 if (TREE_CODE (*arg) == ARRAY_TYPE)
15015 *arg = build_pointer_type (TREE_TYPE (*arg));
15016 else if (TREE_CODE (*arg) == FUNCTION_TYPE)
15017 *arg = build_pointer_type (*arg);
15019 *arg = TYPE_MAIN_VARIANT (*arg);
15022 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
15023 of the form T&&, where T is a template parameter, and the argument
15024 is an lvalue, T is deduced as A& */
15025 if (TREE_CODE (*parm) == REFERENCE_TYPE
15026 && TYPE_REF_IS_RVALUE (*parm)
15027 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
15028 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
15029 && (arg_expr ? real_lvalue_p (arg_expr)
15030 /* try_one_overload doesn't provide an arg_expr, but
15031 functions are always lvalues. */
15032 : TREE_CODE (*arg) == FUNCTION_TYPE))
15033 *arg = build_reference_type (*arg);
15035 /* [temp.deduct.call]
15037 If P is a cv-qualified type, the top level cv-qualifiers
15038 of P's type are ignored for type deduction. If P is a
15039 reference type, the type referred to by P is used for
15041 *parm = TYPE_MAIN_VARIANT (*parm);
15042 if (TREE_CODE (*parm) == REFERENCE_TYPE)
15044 *parm = TREE_TYPE (*parm);
15045 result |= UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
15048 /* DR 322. For conversion deduction, remove a reference type on parm
15049 too (which has been swapped into ARG). */
15050 if (strict == DEDUCE_CONV && TREE_CODE (*arg) == REFERENCE_TYPE)
15051 *arg = TREE_TYPE (*arg);
15056 /* Subroutine of unify_one_argument. PARM is a function parameter of a
15057 template which does contain any deducible template parameters; check if
15058 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
15059 unify_one_argument. */
15062 check_non_deducible_conversion (tree parm, tree arg, int strict,
15063 int flags, bool explain_p)
15068 type = TREE_TYPE (arg);
15072 if (same_type_p (parm, type))
15073 return unify_success (explain_p);
15075 if (strict == DEDUCE_CONV)
15077 if (can_convert_arg (type, parm, NULL_TREE, flags))
15078 return unify_success (explain_p);
15080 else if (strict != DEDUCE_EXACT)
15082 if (can_convert_arg (parm, type,
15083 TYPE_P (arg) ? NULL_TREE : arg,
15085 return unify_success (explain_p);
15088 if (strict == DEDUCE_EXACT)
15089 return unify_type_mismatch (explain_p, parm, arg);
15091 return unify_arg_conversion (explain_p, parm, type, arg);
15094 /* Subroutine of type_unification_real and unify_pack_expansion to
15095 handle unification of a single P/A pair. Parameters are as
15096 for those functions. */
15099 unify_one_argument (tree tparms, tree targs, tree parm, tree arg,
15100 int subr, unification_kind_t strict, int flags,
15103 tree arg_expr = NULL_TREE;
15106 if (arg == error_mark_node || parm == error_mark_node)
15107 return unify_invalid (explain_p);
15108 if (arg == unknown_type_node)
15109 /* We can't deduce anything from this, but we might get all the
15110 template args from other function args. */
15111 return unify_success (explain_p);
15113 /* FIXME uses_deducible_template_parms */
15114 if (TYPE_P (parm) && !uses_template_parms (parm))
15115 return check_non_deducible_conversion (parm, arg, strict, flags,
15121 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
15122 | UNIFY_ALLOW_MORE_CV_QUAL
15123 | UNIFY_ALLOW_DERIVED);
15127 arg_strict = UNIFY_ALLOW_LESS_CV_QUAL;
15131 arg_strict = UNIFY_ALLOW_NONE;
15135 gcc_unreachable ();
15138 /* We only do these transformations if this is the top-level
15139 parameter_type_list in a call or declaration matching; in other
15140 situations (nested function declarators, template argument lists) we
15141 won't be comparing a type to an expression, and we don't do any type
15147 gcc_assert (TREE_TYPE (arg) != NULL_TREE);
15148 if (type_unknown_p (arg))
15150 /* [temp.deduct.type] A template-argument can be
15151 deduced from a pointer to function or pointer
15152 to member function argument if the set of
15153 overloaded functions does not contain function
15154 templates and at most one of a set of
15155 overloaded functions provides a unique
15158 if (resolve_overloaded_unification
15159 (tparms, targs, parm, arg, strict,
15160 arg_strict, explain_p))
15161 return unify_success (explain_p);
15162 return unify_overload_resolution_failure (explain_p, arg);
15166 arg = unlowered_expr_type (arg);
15167 if (arg == error_mark_node)
15168 return unify_invalid (explain_p);
15172 maybe_adjust_types_for_deduction (strict, &parm, &arg, arg_expr);
15175 gcc_assert ((TYPE_P (parm) || TREE_CODE (parm) == TEMPLATE_DECL)
15176 == (TYPE_P (arg) || TREE_CODE (arg) == TEMPLATE_DECL));
15178 /* For deduction from an init-list we need the actual list. */
15179 if (arg_expr && BRACE_ENCLOSED_INITIALIZER_P (arg_expr))
15181 return unify (tparms, targs, parm, arg, arg_strict, explain_p);
15184 /* Most parms like fn_type_unification.
15186 If SUBR is 1, we're being called recursively (to unify the
15187 arguments of a function or method parameter of a function
15191 type_unification_real (tree tparms,
15195 unsigned int xnargs,
15197 unification_kind_t strict,
15203 int ntparms = TREE_VEC_LENGTH (tparms);
15204 int saw_undeduced = 0;
15207 unsigned int nargs;
15210 gcc_assert (TREE_CODE (tparms) == TREE_VEC);
15211 gcc_assert (xparms == NULL_TREE || TREE_CODE (xparms) == TREE_LIST);
15212 gcc_assert (ntparms > 0);
15214 /* Reset the number of non-defaulted template arguments contained
15216 NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs) = NULL_TREE;
15224 while (parms && parms != void_list_node
15227 parm = TREE_VALUE (parms);
15229 if (TREE_CODE (parm) == TYPE_PACK_EXPANSION
15230 && (!TREE_CHAIN (parms) || TREE_CHAIN (parms) == void_list_node))
15231 /* For a function parameter pack that occurs at the end of the
15232 parameter-declaration-list, the type A of each remaining
15233 argument of the call is compared with the type P of the
15234 declarator-id of the function parameter pack. */
15237 parms = TREE_CHAIN (parms);
15239 if (TREE_CODE (parm) == TYPE_PACK_EXPANSION)
15240 /* For a function parameter pack that does not occur at the
15241 end of the parameter-declaration-list, the type of the
15242 parameter pack is a non-deduced context. */
15248 if (unify_one_argument (tparms, targs, parm, arg, subr, strict,
15254 && parms != void_list_node
15255 && TREE_CODE (TREE_VALUE (parms)) == TYPE_PACK_EXPANSION)
15257 /* Unify the remaining arguments with the pack expansion type. */
15259 tree parmvec = make_tree_vec (1);
15261 /* Allocate a TREE_VEC and copy in all of the arguments */
15262 argvec = make_tree_vec (nargs - ia);
15263 for (i = 0; ia < nargs; ++ia, ++i)
15264 TREE_VEC_ELT (argvec, i) = args[ia];
15266 /* Copy the parameter into parmvec. */
15267 TREE_VEC_ELT (parmvec, 0) = TREE_VALUE (parms);
15268 if (unify_pack_expansion (tparms, targs, parmvec, argvec, strict,
15269 /*subr=*/subr, explain_p))
15272 /* Advance to the end of the list of parameters. */
15273 parms = TREE_CHAIN (parms);
15276 /* Fail if we've reached the end of the parm list, and more args
15277 are present, and the parm list isn't variadic. */
15278 if (ia < nargs && parms == void_list_node)
15279 return unify_too_many_arguments (explain_p, nargs, ia);
15280 /* Fail if parms are left and they don't have default values. */
15281 if (parms && parms != void_list_node
15282 && TREE_PURPOSE (parms) == NULL_TREE)
15284 unsigned int count = nargs;
15286 while (p && p != void_list_node)
15289 p = TREE_CHAIN (p);
15291 return unify_too_few_arguments (explain_p, ia, count);
15296 tsubst_flags_t complain = (explain_p
15297 ? tf_warning_or_error
15300 /* Check to see if we need another pass before we start clearing
15301 ARGUMENT_PACK_INCOMPLETE_P. */
15302 for (i = 0; i < ntparms; i++)
15304 tree targ = TREE_VEC_ELT (targs, i);
15305 tree tparm = TREE_VEC_ELT (tparms, i);
15307 if (targ || tparm == error_mark_node)
15309 tparm = TREE_VALUE (tparm);
15311 /* If this is an undeduced nontype parameter that depends on
15312 a type parameter, try another pass; its type may have been
15313 deduced from a later argument than the one from which
15314 this parameter can be deduced. */
15315 if (TREE_CODE (tparm) == PARM_DECL
15316 && uses_template_parms (TREE_TYPE (tparm))
15317 && !saw_undeduced++)
15321 for (i = 0; i < ntparms; i++)
15323 tree targ = TREE_VEC_ELT (targs, i);
15324 tree tparm = TREE_VEC_ELT (tparms, i);
15326 /* Clear the "incomplete" flags on all argument packs now so that
15327 substituting them into later default arguments works. */
15328 if (targ && ARGUMENT_PACK_P (targ))
15330 ARGUMENT_PACK_INCOMPLETE_P (targ) = 0;
15331 ARGUMENT_PACK_EXPLICIT_ARGS (targ) = NULL_TREE;
15334 if (targ || tparm == error_mark_node)
15336 tparm = TREE_VALUE (tparm);
15338 /* Core issue #226 (C++0x) [temp.deduct]:
15340 If a template argument has not been deduced, its
15341 default template argument, if any, is used.
15343 When we are in C++98 mode, TREE_PURPOSE will either
15344 be NULL_TREE or ERROR_MARK_NODE, so we do not need
15345 to explicitly check cxx_dialect here. */
15346 if (TREE_PURPOSE (TREE_VEC_ELT (tparms, i)))
15348 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
15349 tree arg = TREE_PURPOSE (TREE_VEC_ELT (tparms, i));
15350 location_t save_loc = input_location;
15352 input_location = DECL_SOURCE_LOCATION (parm);
15353 arg = tsubst_template_arg (arg, targs, complain, NULL_TREE);
15354 arg = convert_template_argument (parm, arg, targs, complain,
15356 input_location = save_loc;
15357 if (arg == error_mark_node)
15361 TREE_VEC_ELT (targs, i) = arg;
15362 /* The position of the first default template argument,
15363 is also the number of non-defaulted arguments in TARGS.
15365 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs))
15366 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, i);
15371 /* If the type parameter is a parameter pack, then it will
15372 be deduced to an empty parameter pack. */
15373 if (template_parameter_pack_p (tparm))
15377 if (TREE_CODE (tparm) == TEMPLATE_PARM_INDEX)
15379 arg = make_node (NONTYPE_ARGUMENT_PACK);
15380 TREE_TYPE (arg) = TREE_TYPE (TEMPLATE_PARM_DECL (tparm));
15381 TREE_CONSTANT (arg) = 1;
15384 arg = cxx_make_type (TYPE_ARGUMENT_PACK);
15386 SET_ARGUMENT_PACK_ARGS (arg, make_tree_vec (0));
15388 TREE_VEC_ELT (targs, i) = arg;
15392 return unify_parameter_deduction_failure (explain_p, tparm);
15395 #ifdef ENABLE_CHECKING
15396 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs))
15397 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, TREE_VEC_LENGTH (targs));
15400 return unify_success (explain_p);
15403 /* Subroutine of type_unification_real. Args are like the variables
15404 at the call site. ARG is an overloaded function (or template-id);
15405 we try deducing template args from each of the overloads, and if
15406 only one succeeds, we go with that. Modifies TARGS and returns
15407 true on success. */
15410 resolve_overloaded_unification (tree tparms,
15414 unification_kind_t strict,
15418 tree tempargs = copy_node (targs);
15420 tree goodfn = NULL_TREE;
15423 if (TREE_CODE (arg) == ADDR_EXPR)
15425 arg = TREE_OPERAND (arg, 0);
15431 if (TREE_CODE (arg) == COMPONENT_REF)
15432 /* Handle `&x' where `x' is some static or non-static member
15434 arg = TREE_OPERAND (arg, 1);
15436 if (TREE_CODE (arg) == OFFSET_REF)
15437 arg = TREE_OPERAND (arg, 1);
15439 /* Strip baselink information. */
15440 if (BASELINK_P (arg))
15441 arg = BASELINK_FUNCTIONS (arg);
15443 if (TREE_CODE (arg) == TEMPLATE_ID_EXPR)
15445 /* If we got some explicit template args, we need to plug them into
15446 the affected templates before we try to unify, in case the
15447 explicit args will completely resolve the templates in question. */
15450 tree expl_subargs = TREE_OPERAND (arg, 1);
15451 arg = TREE_OPERAND (arg, 0);
15453 for (; arg; arg = OVL_NEXT (arg))
15455 tree fn = OVL_CURRENT (arg);
15456 tree subargs, elem;
15458 if (TREE_CODE (fn) != TEMPLATE_DECL)
15461 ++processing_template_decl;
15462 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
15463 expl_subargs, /*check_ret=*/false);
15464 if (subargs && !any_dependent_template_arguments_p (subargs))
15466 elem = tsubst (TREE_TYPE (fn), subargs, tf_none, NULL_TREE);
15467 if (try_one_overload (tparms, targs, tempargs, parm,
15468 elem, strict, sub_strict, addr_p, explain_p)
15469 && (!goodfn || !decls_match (goodfn, elem)))
15477 --processing_template_decl;
15479 /* If no templates (or more than one) are fully resolved by the
15480 explicit arguments, this template-id is a non-deduced context; it
15481 could still be OK if we deduce all template arguments for the
15482 enclosing call through other arguments. */
15486 else if (TREE_CODE (arg) != OVERLOAD
15487 && TREE_CODE (arg) != FUNCTION_DECL)
15488 /* If ARG is, for example, "(0, &f)" then its type will be unknown
15489 -- but the deduction does not succeed because the expression is
15490 not just the function on its own. */
15493 for (; arg; arg = OVL_NEXT (arg))
15494 if (try_one_overload (tparms, targs, tempargs, parm,
15495 TREE_TYPE (OVL_CURRENT (arg)),
15496 strict, sub_strict, addr_p, explain_p)
15497 && (!goodfn || !decls_match (goodfn, OVL_CURRENT (arg))))
15499 goodfn = OVL_CURRENT (arg);
15503 /* [temp.deduct.type] A template-argument can be deduced from a pointer
15504 to function or pointer to member function argument if the set of
15505 overloaded functions does not contain function templates and at most
15506 one of a set of overloaded functions provides a unique match.
15508 So if we found multiple possibilities, we return success but don't
15509 deduce anything. */
15513 int i = TREE_VEC_LENGTH (targs);
15515 if (TREE_VEC_ELT (tempargs, i))
15516 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (tempargs, i);
15524 /* Core DR 115: In contexts where deduction is done and fails, or in
15525 contexts where deduction is not done, if a template argument list is
15526 specified and it, along with any default template arguments, identifies
15527 a single function template specialization, then the template-id is an
15528 lvalue for the function template specialization. */
15531 resolve_nondeduced_context (tree orig_expr)
15533 tree expr, offset, baselink;
15536 if (!type_unknown_p (orig_expr))
15541 offset = NULL_TREE;
15542 baselink = NULL_TREE;
15544 if (TREE_CODE (expr) == ADDR_EXPR)
15546 expr = TREE_OPERAND (expr, 0);
15549 if (TREE_CODE (expr) == OFFSET_REF)
15552 expr = TREE_OPERAND (expr, 1);
15554 if (BASELINK_P (expr))
15557 expr = BASELINK_FUNCTIONS (expr);
15560 if (TREE_CODE (expr) == TEMPLATE_ID_EXPR)
15563 tree goodfn = NULL_TREE;
15565 /* If we got some explicit template args, we need to plug them into
15566 the affected templates before we try to unify, in case the
15567 explicit args will completely resolve the templates in question. */
15569 tree expl_subargs = TREE_OPERAND (expr, 1);
15570 tree arg = TREE_OPERAND (expr, 0);
15571 tree badfn = NULL_TREE;
15572 tree badargs = NULL_TREE;
15574 for (; arg; arg = OVL_NEXT (arg))
15576 tree fn = OVL_CURRENT (arg);
15577 tree subargs, elem;
15579 if (TREE_CODE (fn) != TEMPLATE_DECL)
15582 ++processing_template_decl;
15583 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
15584 expl_subargs, /*check_ret=*/false);
15585 if (subargs && !any_dependent_template_arguments_p (subargs))
15587 elem = instantiate_template (fn, subargs, tf_none);
15588 if (elem == error_mark_node)
15593 else if (elem && (!goodfn || !decls_match (goodfn, elem)))
15599 --processing_template_decl;
15603 mark_used (goodfn);
15606 expr = build_baselink (BASELINK_BINFO (baselink),
15607 BASELINK_ACCESS_BINFO (baselink),
15608 expr, BASELINK_OPTYPE (baselink));
15612 = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (offset, 0)));
15613 expr = build_offset_ref (base, expr, addr);
15616 expr = cp_build_addr_expr (expr, tf_warning_or_error);
15619 else if (good == 0 && badargs)
15620 /* There were no good options and at least one bad one, so let the
15621 user know what the problem is. */
15622 instantiate_template (badfn, badargs, tf_warning_or_error);
15627 /* Subroutine of resolve_overloaded_unification; does deduction for a single
15628 overload. Fills TARGS with any deduced arguments, or error_mark_node if
15629 different overloads deduce different arguments for a given parm.
15630 ADDR_P is true if the expression for which deduction is being
15631 performed was of the form "& fn" rather than simply "fn".
15633 Returns 1 on success. */
15636 try_one_overload (tree tparms,
15641 unification_kind_t strict,
15650 /* [temp.deduct.type] A template-argument can be deduced from a pointer
15651 to function or pointer to member function argument if the set of
15652 overloaded functions does not contain function templates and at most
15653 one of a set of overloaded functions provides a unique match.
15655 So if this is a template, just return success. */
15657 if (uses_template_parms (arg))
15660 if (TREE_CODE (arg) == METHOD_TYPE)
15661 arg = build_ptrmemfunc_type (build_pointer_type (arg));
15663 arg = build_pointer_type (arg);
15665 sub_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg, NULL);
15667 /* We don't copy orig_targs for this because if we have already deduced
15668 some template args from previous args, unify would complain when we
15669 try to deduce a template parameter for the same argument, even though
15670 there isn't really a conflict. */
15671 nargs = TREE_VEC_LENGTH (targs);
15672 tempargs = make_tree_vec (nargs);
15674 if (unify (tparms, tempargs, parm, arg, sub_strict, explain_p))
15677 /* First make sure we didn't deduce anything that conflicts with
15678 explicitly specified args. */
15679 for (i = nargs; i--; )
15681 tree elt = TREE_VEC_ELT (tempargs, i);
15682 tree oldelt = TREE_VEC_ELT (orig_targs, i);
15686 else if (uses_template_parms (elt))
15687 /* Since we're unifying against ourselves, we will fill in
15688 template args used in the function parm list with our own
15689 template parms. Discard them. */
15690 TREE_VEC_ELT (tempargs, i) = NULL_TREE;
15691 else if (oldelt && !template_args_equal (oldelt, elt))
15695 for (i = nargs; i--; )
15697 tree elt = TREE_VEC_ELT (tempargs, i);
15700 TREE_VEC_ELT (targs, i) = elt;
15706 /* PARM is a template class (perhaps with unbound template
15707 parameters). ARG is a fully instantiated type. If ARG can be
15708 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
15709 TARGS are as for unify. */
15712 try_class_unification (tree tparms, tree targs, tree parm, tree arg,
15715 tree copy_of_targs;
15717 if (!CLASSTYPE_TEMPLATE_INFO (arg)
15718 || (most_general_template (CLASSTYPE_TI_TEMPLATE (arg))
15719 != most_general_template (CLASSTYPE_TI_TEMPLATE (parm))))
15722 /* We need to make a new template argument vector for the call to
15723 unify. If we used TARGS, we'd clutter it up with the result of
15724 the attempted unification, even if this class didn't work out.
15725 We also don't want to commit ourselves to all the unifications
15726 we've already done, since unification is supposed to be done on
15727 an argument-by-argument basis. In other words, consider the
15728 following pathological case:
15730 template <int I, int J, int K>
15733 template <int I, int J>
15734 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
15736 template <int I, int J, int K>
15737 void f(S<I, J, K>, S<I, I, I>);
15746 Now, by the time we consider the unification involving `s2', we
15747 already know that we must have `f<0, 0, 0>'. But, even though
15748 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
15749 because there are two ways to unify base classes of S<0, 1, 2>
15750 with S<I, I, I>. If we kept the already deduced knowledge, we
15751 would reject the possibility I=1. */
15752 copy_of_targs = make_tree_vec (TREE_VEC_LENGTH (targs));
15754 /* If unification failed, we're done. */
15755 if (unify (tparms, copy_of_targs, CLASSTYPE_TI_ARGS (parm),
15756 CLASSTYPE_TI_ARGS (arg), UNIFY_ALLOW_NONE, explain_p))
15762 /* Given a template type PARM and a class type ARG, find the unique
15763 base type in ARG that is an instance of PARM. We do not examine
15764 ARG itself; only its base-classes. If there is not exactly one
15765 appropriate base class, return NULL_TREE. PARM may be the type of
15766 a partial specialization, as well as a plain template type. Used
15769 static enum template_base_result
15770 get_template_base (tree tparms, tree targs, tree parm, tree arg,
15771 bool explain_p, tree *result)
15773 tree rval = NULL_TREE;
15776 gcc_assert (RECORD_OR_UNION_CODE_P (TREE_CODE (arg)));
15778 binfo = TYPE_BINFO (complete_type (arg));
15781 /* The type could not be completed. */
15782 *result = NULL_TREE;
15783 return tbr_incomplete_type;
15786 /* Walk in inheritance graph order. The search order is not
15787 important, and this avoids multiple walks of virtual bases. */
15788 for (binfo = TREE_CHAIN (binfo); binfo; binfo = TREE_CHAIN (binfo))
15790 tree r = try_class_unification (tparms, targs, parm,
15791 BINFO_TYPE (binfo), explain_p);
15795 /* If there is more than one satisfactory baseclass, then:
15799 If they yield more than one possible deduced A, the type
15803 if (rval && !same_type_p (r, rval))
15805 *result = NULL_TREE;
15806 return tbr_ambiguous_baseclass;
15814 return tbr_success;
15817 /* Returns the level of DECL, which declares a template parameter. */
15820 template_decl_level (tree decl)
15822 switch (TREE_CODE (decl))
15825 case TEMPLATE_DECL:
15826 return TEMPLATE_TYPE_LEVEL (TREE_TYPE (decl));
15829 return TEMPLATE_PARM_LEVEL (DECL_INITIAL (decl));
15832 gcc_unreachable ();
15837 /* Decide whether ARG can be unified with PARM, considering only the
15838 cv-qualifiers of each type, given STRICT as documented for unify.
15839 Returns nonzero iff the unification is OK on that basis. */
15842 check_cv_quals_for_unify (int strict, tree arg, tree parm)
15844 int arg_quals = cp_type_quals (arg);
15845 int parm_quals = cp_type_quals (parm);
15847 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
15848 && !(strict & UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
15850 /* Although a CVR qualifier is ignored when being applied to a
15851 substituted template parameter ([8.3.2]/1 for example), that
15852 does not allow us to unify "const T" with "int&" because both
15853 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
15854 It is ok when we're allowing additional CV qualifiers
15855 at the outer level [14.8.2.1]/3,1st bullet. */
15856 if ((TREE_CODE (arg) == REFERENCE_TYPE
15857 || TREE_CODE (arg) == FUNCTION_TYPE
15858 || TREE_CODE (arg) == METHOD_TYPE)
15859 && (parm_quals & (TYPE_QUAL_CONST | TYPE_QUAL_VOLATILE)))
15862 if ((!POINTER_TYPE_P (arg) && TREE_CODE (arg) != TEMPLATE_TYPE_PARM)
15863 && (parm_quals & TYPE_QUAL_RESTRICT))
15867 if (!(strict & (UNIFY_ALLOW_MORE_CV_QUAL | UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
15868 && (arg_quals & parm_quals) != parm_quals)
15871 if (!(strict & (UNIFY_ALLOW_LESS_CV_QUAL | UNIFY_ALLOW_OUTER_LESS_CV_QUAL))
15872 && (parm_quals & arg_quals) != arg_quals)
15878 /* Determines the LEVEL and INDEX for the template parameter PARM. */
15880 template_parm_level_and_index (tree parm, int* level, int* index)
15882 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
15883 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
15884 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
15886 *index = TEMPLATE_TYPE_IDX (parm);
15887 *level = TEMPLATE_TYPE_LEVEL (parm);
15891 *index = TEMPLATE_PARM_IDX (parm);
15892 *level = TEMPLATE_PARM_LEVEL (parm);
15896 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
15898 if (unify (TP, TA, P, A, S, EP)) \
15902 /* Unifies the remaining arguments in PACKED_ARGS with the pack
15903 expansion at the end of PACKED_PARMS. Returns 0 if the type
15904 deduction succeeds, 1 otherwise. STRICT is the same as in
15905 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
15906 call argument list. We'll need to adjust the arguments to make them
15907 types. SUBR tells us if this is from a recursive call to
15908 type_unification_real, or for comparing two template argument
15912 unify_pack_expansion (tree tparms, tree targs, tree packed_parms,
15913 tree packed_args, unification_kind_t strict,
15914 bool subr, bool explain_p)
15917 = TREE_VEC_ELT (packed_parms, TREE_VEC_LENGTH (packed_parms) - 1);
15918 tree pattern = PACK_EXPANSION_PATTERN (parm);
15919 tree pack, packs = NULL_TREE;
15920 int i, start = TREE_VEC_LENGTH (packed_parms) - 1;
15921 int len = TREE_VEC_LENGTH (packed_args);
15923 /* Determine the parameter packs we will be deducing from the
15924 pattern, and record their current deductions. */
15925 for (pack = PACK_EXPANSION_PARAMETER_PACKS (parm);
15926 pack; pack = TREE_CHAIN (pack))
15928 tree parm_pack = TREE_VALUE (pack);
15931 /* Determine the index and level of this parameter pack. */
15932 template_parm_level_and_index (parm_pack, &level, &idx);
15934 /* Keep track of the parameter packs and their corresponding
15936 packs = tree_cons (parm_pack, TMPL_ARG (targs, level, idx), packs);
15937 TREE_TYPE (packs) = make_tree_vec (len - start);
15940 /* Loop through all of the arguments that have not yet been
15941 unified and unify each with the pattern. */
15942 for (i = start; i < len; i++)
15945 bool any_explicit = false;
15946 tree arg = TREE_VEC_ELT (packed_args, i);
15948 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
15949 or the element of its argument pack at the current index if
15950 this argument was explicitly specified. */
15951 for (pack = packs; pack; pack = TREE_CHAIN (pack))
15955 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
15958 if (TREE_VALUE (pack)
15959 && (pargs = ARGUMENT_PACK_EXPLICIT_ARGS (TREE_VALUE (pack)))
15960 && (i < TREE_VEC_LENGTH (pargs)))
15962 any_explicit = true;
15963 arg = TREE_VEC_ELT (pargs, i);
15965 TMPL_ARG (targs, level, idx) = arg;
15968 /* If we had explicit template arguments, substitute them into the
15969 pattern before deduction. */
15972 /* Some arguments might still be unspecified or dependent. */
15974 ++processing_template_decl;
15975 dependent = any_dependent_template_arguments_p (targs);
15977 --processing_template_decl;
15978 parm = tsubst (pattern, targs,
15979 explain_p ? tf_warning_or_error : tf_none,
15982 --processing_template_decl;
15983 if (parm == error_mark_node)
15989 /* Unify the pattern with the current argument. */
15990 if (unify_one_argument (tparms, targs, parm, arg, subr, strict,
15991 LOOKUP_IMPLICIT, explain_p))
15994 /* For each parameter pack, collect the deduced value. */
15995 for (pack = packs; pack; pack = TREE_CHAIN (pack))
15998 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
16000 TREE_VEC_ELT (TREE_TYPE (pack), i - start) =
16001 TMPL_ARG (targs, level, idx);
16005 /* Verify that the results of unification with the parameter packs
16006 produce results consistent with what we've seen before, and make
16007 the deduced argument packs available. */
16008 for (pack = packs; pack; pack = TREE_CHAIN (pack))
16010 tree old_pack = TREE_VALUE (pack);
16011 tree new_args = TREE_TYPE (pack);
16012 int i, len = TREE_VEC_LENGTH (new_args);
16014 bool nondeduced_p = false;
16016 /* By default keep the original deduced argument pack.
16017 If necessary, more specific code is going to update the
16018 resulting deduced argument later down in this function. */
16019 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
16020 TMPL_ARG (targs, level, idx) = old_pack;
16022 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
16023 actually deduce anything. */
16024 for (i = 0; i < len && !nondeduced_p; ++i)
16025 if (TREE_VEC_ELT (new_args, i) == NULL_TREE)
16026 nondeduced_p = true;
16030 if (old_pack && ARGUMENT_PACK_INCOMPLETE_P (old_pack))
16032 /* If we had fewer function args than explicit template args,
16033 just use the explicits. */
16034 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
16035 int explicit_len = TREE_VEC_LENGTH (explicit_args);
16036 if (len < explicit_len)
16037 new_args = explicit_args;
16043 /* Build the deduced *_ARGUMENT_PACK. */
16044 if (TREE_CODE (TREE_PURPOSE (pack)) == TEMPLATE_PARM_INDEX)
16046 result = make_node (NONTYPE_ARGUMENT_PACK);
16047 TREE_TYPE (result) =
16048 TREE_TYPE (TEMPLATE_PARM_DECL (TREE_PURPOSE (pack)));
16049 TREE_CONSTANT (result) = 1;
16052 result = cxx_make_type (TYPE_ARGUMENT_PACK);
16054 SET_ARGUMENT_PACK_ARGS (result, new_args);
16056 /* Note the deduced argument packs for this parameter
16058 TMPL_ARG (targs, level, idx) = result;
16060 else if (ARGUMENT_PACK_INCOMPLETE_P (old_pack)
16061 && (ARGUMENT_PACK_ARGS (old_pack)
16062 == ARGUMENT_PACK_EXPLICIT_ARGS (old_pack)))
16064 /* We only had the explicitly-provided arguments before, but
16065 now we have a complete set of arguments. */
16066 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
16068 SET_ARGUMENT_PACK_ARGS (old_pack, new_args);
16069 ARGUMENT_PACK_INCOMPLETE_P (old_pack) = 1;
16070 ARGUMENT_PACK_EXPLICIT_ARGS (old_pack) = explicit_args;
16074 tree bad_old_arg = NULL_TREE, bad_new_arg = NULL_TREE;
16075 tree old_args = ARGUMENT_PACK_ARGS (old_pack);
16077 if (!comp_template_args_with_info (old_args, new_args,
16078 &bad_old_arg, &bad_new_arg))
16079 /* Inconsistent unification of this parameter pack. */
16080 return unify_parameter_pack_inconsistent (explain_p,
16086 return unify_success (explain_p);
16089 /* Deduce the value of template parameters. TPARMS is the (innermost)
16090 set of template parameters to a template. TARGS is the bindings
16091 for those template parameters, as determined thus far; TARGS may
16092 include template arguments for outer levels of template parameters
16093 as well. PARM is a parameter to a template function, or a
16094 subcomponent of that parameter; ARG is the corresponding argument.
16095 This function attempts to match PARM with ARG in a manner
16096 consistent with the existing assignments in TARGS. If more values
16097 are deduced, then TARGS is updated.
16099 Returns 0 if the type deduction succeeds, 1 otherwise. The
16100 parameter STRICT is a bitwise or of the following flags:
16103 Require an exact match between PARM and ARG.
16104 UNIFY_ALLOW_MORE_CV_QUAL:
16105 Allow the deduced ARG to be more cv-qualified (by qualification
16106 conversion) than ARG.
16107 UNIFY_ALLOW_LESS_CV_QUAL:
16108 Allow the deduced ARG to be less cv-qualified than ARG.
16109 UNIFY_ALLOW_DERIVED:
16110 Allow the deduced ARG to be a template base class of ARG,
16111 or a pointer to a template base class of the type pointed to by
16113 UNIFY_ALLOW_INTEGER:
16114 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
16115 case for more information.
16116 UNIFY_ALLOW_OUTER_LEVEL:
16117 This is the outermost level of a deduction. Used to determine validity
16118 of qualification conversions. A valid qualification conversion must
16119 have const qualified pointers leading up to the inner type which
16120 requires additional CV quals, except at the outer level, where const
16121 is not required [conv.qual]. It would be normal to set this flag in
16122 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
16123 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
16124 This is the outermost level of a deduction, and PARM can be more CV
16125 qualified at this point.
16126 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
16127 This is the outermost level of a deduction, and PARM can be less CV
16128 qualified at this point. */
16131 unify (tree tparms, tree targs, tree parm, tree arg, int strict,
16137 int strict_in = strict;
16139 /* I don't think this will do the right thing with respect to types.
16140 But the only case I've seen it in so far has been array bounds, where
16141 signedness is the only information lost, and I think that will be
16143 while (TREE_CODE (parm) == NOP_EXPR)
16144 parm = TREE_OPERAND (parm, 0);
16146 if (arg == error_mark_node)
16147 return unify_invalid (explain_p);
16148 if (arg == unknown_type_node
16149 || arg == init_list_type_node)
16150 /* We can't deduce anything from this, but we might get all the
16151 template args from other function args. */
16152 return unify_success (explain_p);
16154 /* If PARM uses template parameters, then we can't bail out here,
16155 even if ARG == PARM, since we won't record unifications for the
16156 template parameters. We might need them if we're trying to
16157 figure out which of two things is more specialized. */
16158 if (arg == parm && !uses_template_parms (parm))
16159 return unify_success (explain_p);
16161 /* Handle init lists early, so the rest of the function can assume
16162 we're dealing with a type. */
16163 if (BRACE_ENCLOSED_INITIALIZER_P (arg))
16167 tree orig_parm = parm;
16169 /* Replace T with std::initializer_list<T> for deduction. */
16170 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
16171 && flag_deduce_init_list)
16172 parm = listify (parm);
16174 if (!is_std_init_list (parm))
16175 /* We can only deduce from an initializer list argument if the
16176 parameter is std::initializer_list; otherwise this is a
16177 non-deduced context. */
16178 return unify_success (explain_p);
16180 elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (parm), 0);
16182 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg), i, elt)
16184 int elt_strict = strict;
16186 if (elt == error_mark_node)
16187 return unify_invalid (explain_p);
16189 if (!BRACE_ENCLOSED_INITIALIZER_P (elt))
16191 tree type = TREE_TYPE (elt);
16192 /* It should only be possible to get here for a call. */
16193 gcc_assert (elt_strict & UNIFY_ALLOW_OUTER_LEVEL);
16194 elt_strict |= maybe_adjust_types_for_deduction
16195 (DEDUCE_CALL, &elttype, &type, elt);
16199 RECUR_AND_CHECK_FAILURE (tparms, targs, elttype, elt, elt_strict,
16203 /* If the std::initializer_list<T> deduction worked, replace the
16204 deduced A with std::initializer_list<A>. */
16205 if (orig_parm != parm)
16207 idx = TEMPLATE_TYPE_IDX (orig_parm);
16208 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
16209 targ = listify (targ);
16210 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = targ;
16212 return unify_success (explain_p);
16215 /* Immediately reject some pairs that won't unify because of
16216 cv-qualification mismatches. */
16217 if (TREE_CODE (arg) == TREE_CODE (parm)
16219 /* It is the elements of the array which hold the cv quals of an array
16220 type, and the elements might be template type parms. We'll check
16221 when we recurse. */
16222 && TREE_CODE (arg) != ARRAY_TYPE
16223 /* We check the cv-qualifiers when unifying with template type
16224 parameters below. We want to allow ARG `const T' to unify with
16225 PARM `T' for example, when computing which of two templates
16226 is more specialized, for example. */
16227 && TREE_CODE (arg) != TEMPLATE_TYPE_PARM
16228 && !check_cv_quals_for_unify (strict_in, arg, parm))
16229 return unify_cv_qual_mismatch (explain_p, parm, arg);
16231 if (!(strict & UNIFY_ALLOW_OUTER_LEVEL)
16232 && TYPE_P (parm) && !CP_TYPE_CONST_P (parm))
16233 strict &= ~UNIFY_ALLOW_MORE_CV_QUAL;
16234 strict &= ~UNIFY_ALLOW_OUTER_LEVEL;
16235 strict &= ~UNIFY_ALLOW_DERIVED;
16236 strict &= ~UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
16237 strict &= ~UNIFY_ALLOW_OUTER_LESS_CV_QUAL;
16239 switch (TREE_CODE (parm))
16241 case TYPENAME_TYPE:
16243 case UNBOUND_CLASS_TEMPLATE:
16244 /* In a type which contains a nested-name-specifier, template
16245 argument values cannot be deduced for template parameters used
16246 within the nested-name-specifier. */
16247 return unify_success (explain_p);
16249 case TEMPLATE_TYPE_PARM:
16250 case TEMPLATE_TEMPLATE_PARM:
16251 case BOUND_TEMPLATE_TEMPLATE_PARM:
16252 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
16253 if (tparm == error_mark_node)
16254 return unify_invalid (explain_p);
16256 if (TEMPLATE_TYPE_LEVEL (parm)
16257 != template_decl_level (tparm))
16258 /* The PARM is not one we're trying to unify. Just check
16259 to see if it matches ARG. */
16261 if (TREE_CODE (arg) == TREE_CODE (parm)
16262 && same_type_p (parm, arg))
16263 return unify_success (explain_p);
16265 return unify_type_mismatch (explain_p, parm, arg);
16267 idx = TEMPLATE_TYPE_IDX (parm);
16268 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
16269 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, idx));
16271 /* Check for mixed types and values. */
16272 if ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
16273 && TREE_CODE (tparm) != TYPE_DECL)
16274 || (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
16275 && TREE_CODE (tparm) != TEMPLATE_DECL))
16276 gcc_unreachable ();
16278 if (TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
16280 /* ARG must be constructed from a template class or a template
16281 template parameter. */
16282 if (TREE_CODE (arg) != BOUND_TEMPLATE_TEMPLATE_PARM
16283 && !CLASSTYPE_SPECIALIZATION_OF_PRIMARY_TEMPLATE_P (arg))
16284 return unify_template_deduction_failure (explain_p, parm, arg);
16287 tree parmvec = TYPE_TI_ARGS (parm);
16288 tree argvec = INNERMOST_TEMPLATE_ARGS (TYPE_TI_ARGS (arg));
16289 tree full_argvec = add_to_template_args (targs, argvec);
16291 = DECL_INNERMOST_TEMPLATE_PARMS
16292 (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (parm));
16294 int parm_variadic_p = 0;
16296 /* The resolution to DR150 makes clear that default
16297 arguments for an N-argument may not be used to bind T
16298 to a template template parameter with fewer than N
16299 parameters. It is not safe to permit the binding of
16300 default arguments as an extension, as that may change
16301 the meaning of a conforming program. Consider:
16303 struct Dense { static const unsigned int dim = 1; };
16305 template <template <typename> class View,
16307 void operator+(float, View<Block> const&);
16309 template <typename Block,
16310 unsigned int Dim = Block::dim>
16311 struct Lvalue_proxy { operator float() const; };
16315 Lvalue_proxy<Dense> p;
16320 Here, if Lvalue_proxy is permitted to bind to View, then
16321 the global operator+ will be used; if they are not, the
16322 Lvalue_proxy will be converted to float. */
16323 if (coerce_template_parms (parm_parms,
16325 TYPE_TI_TEMPLATE (parm),
16327 ? tf_warning_or_error
16329 /*require_all_args=*/true,
16330 /*use_default_args=*/false)
16331 == error_mark_node)
16334 /* Deduce arguments T, i from TT<T> or TT<i>.
16335 We check each element of PARMVEC and ARGVEC individually
16336 rather than the whole TREE_VEC since they can have
16337 different number of elements. */
16339 parmvec = expand_template_argument_pack (parmvec);
16340 argvec = expand_template_argument_pack (argvec);
16342 len = TREE_VEC_LENGTH (parmvec);
16344 /* Check if the parameters end in a pack, making them
16347 && PACK_EXPANSION_P (TREE_VEC_ELT (parmvec, len - 1)))
16348 parm_variadic_p = 1;
16350 if (TREE_VEC_LENGTH (argvec) < len - parm_variadic_p)
16351 return unify_too_few_arguments (explain_p,
16352 TREE_VEC_LENGTH (argvec), len);
16354 for (i = 0; i < len - parm_variadic_p; ++i)
16356 RECUR_AND_CHECK_FAILURE (tparms, targs,
16357 TREE_VEC_ELT (parmvec, i),
16358 TREE_VEC_ELT (argvec, i),
16359 UNIFY_ALLOW_NONE, explain_p);
16362 if (parm_variadic_p
16363 && unify_pack_expansion (tparms, targs,
16366 /*subr=*/true, explain_p))
16369 arg = TYPE_TI_TEMPLATE (arg);
16371 /* Fall through to deduce template name. */
16374 if (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
16375 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
16377 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
16379 /* Simple cases: Value already set, does match or doesn't. */
16380 if (targ != NULL_TREE && template_args_equal (targ, arg))
16381 return unify_success (explain_p);
16383 return unify_inconsistency (explain_p, parm, targ, arg);
16387 /* If PARM is `const T' and ARG is only `int', we don't have
16388 a match unless we are allowing additional qualification.
16389 If ARG is `const int' and PARM is just `T' that's OK;
16390 that binds `const int' to `T'. */
16391 if (!check_cv_quals_for_unify (strict_in | UNIFY_ALLOW_LESS_CV_QUAL,
16393 return unify_cv_qual_mismatch (explain_p, parm, arg);
16395 /* Consider the case where ARG is `const volatile int' and
16396 PARM is `const T'. Then, T should be `volatile int'. */
16397 arg = cp_build_qualified_type_real
16398 (arg, cp_type_quals (arg) & ~cp_type_quals (parm), tf_none);
16399 if (arg == error_mark_node)
16400 return unify_invalid (explain_p);
16402 /* Simple cases: Value already set, does match or doesn't. */
16403 if (targ != NULL_TREE && same_type_p (targ, arg))
16404 return unify_success (explain_p);
16406 return unify_inconsistency (explain_p, parm, targ, arg);
16408 /* Make sure that ARG is not a variable-sized array. (Note
16409 that were talking about variable-sized arrays (like
16410 `int[n]'), rather than arrays of unknown size (like
16411 `int[]').) We'll get very confused by such a type since
16412 the bound of the array is not constant, and therefore
16413 not mangleable. Besides, such types are not allowed in
16414 ISO C++, so we can do as we please here. We do allow
16415 them for 'auto' deduction, since that isn't ABI-exposed. */
16416 if (!is_auto (parm) && variably_modified_type_p (arg, NULL_TREE))
16417 return unify_vla_arg (explain_p, arg);
16419 /* Strip typedefs as in convert_template_argument. */
16420 arg = canonicalize_type_argument (arg, tf_none);
16423 /* If ARG is a parameter pack or an expansion, we cannot unify
16424 against it unless PARM is also a parameter pack. */
16425 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
16426 && !template_parameter_pack_p (parm))
16427 return unify_parameter_pack_mismatch (explain_p, parm, arg);
16429 /* If the argument deduction results is a METHOD_TYPE,
16430 then there is a problem.
16431 METHOD_TYPE doesn't map to any real C++ type the result of
16432 the deduction can not be of that type. */
16433 if (TREE_CODE (arg) == METHOD_TYPE)
16434 return unify_method_type_error (explain_p, arg);
16436 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
16437 return unify_success (explain_p);
16439 case TEMPLATE_PARM_INDEX:
16440 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
16441 if (tparm == error_mark_node)
16442 return unify_invalid (explain_p);
16444 if (TEMPLATE_PARM_LEVEL (parm)
16445 != template_decl_level (tparm))
16447 /* The PARM is not one we're trying to unify. Just check
16448 to see if it matches ARG. */
16449 int result = !(TREE_CODE (arg) == TREE_CODE (parm)
16450 && cp_tree_equal (parm, arg));
16452 unify_expression_unequal (explain_p, parm, arg);
16456 idx = TEMPLATE_PARM_IDX (parm);
16457 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
16461 int x = !cp_tree_equal (targ, arg);
16463 unify_inconsistency (explain_p, parm, targ, arg);
16467 /* [temp.deduct.type] If, in the declaration of a function template
16468 with a non-type template-parameter, the non-type
16469 template-parameter is used in an expression in the function
16470 parameter-list and, if the corresponding template-argument is
16471 deduced, the template-argument type shall match the type of the
16472 template-parameter exactly, except that a template-argument
16473 deduced from an array bound may be of any integral type.
16474 The non-type parameter might use already deduced type parameters. */
16475 tparm = tsubst (TREE_TYPE (parm), targs, 0, NULL_TREE);
16476 if (!TREE_TYPE (arg))
16477 /* Template-parameter dependent expression. Just accept it for now.
16478 It will later be processed in convert_template_argument. */
16480 else if (same_type_p (TREE_TYPE (arg), tparm))
16482 else if ((strict & UNIFY_ALLOW_INTEGER)
16483 && (TREE_CODE (tparm) == INTEGER_TYPE
16484 || TREE_CODE (tparm) == BOOLEAN_TYPE))
16485 /* Convert the ARG to the type of PARM; the deduced non-type
16486 template argument must exactly match the types of the
16487 corresponding parameter. */
16488 arg = fold (build_nop (tparm, arg));
16489 else if (uses_template_parms (tparm))
16490 /* We haven't deduced the type of this parameter yet. Try again
16492 return unify_success (explain_p);
16494 return unify_type_mismatch (explain_p, tparm, arg);
16496 /* If ARG is a parameter pack or an expansion, we cannot unify
16497 against it unless PARM is also a parameter pack. */
16498 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
16499 && !TEMPLATE_PARM_PARAMETER_PACK (parm))
16500 return unify_parameter_pack_mismatch (explain_p, parm, arg);
16502 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
16503 return unify_success (explain_p);
16507 /* A pointer-to-member constant can be unified only with
16508 another constant. */
16509 if (TREE_CODE (arg) != PTRMEM_CST)
16510 return unify_ptrmem_cst_mismatch (explain_p, parm, arg);
16512 /* Just unify the class member. It would be useless (and possibly
16513 wrong, depending on the strict flags) to unify also
16514 PTRMEM_CST_CLASS, because we want to be sure that both parm and
16515 arg refer to the same variable, even if through different
16516 classes. For instance:
16518 struct A { int x; };
16521 Unification of &A::x and &B::x must succeed. */
16522 return unify (tparms, targs, PTRMEM_CST_MEMBER (parm),
16523 PTRMEM_CST_MEMBER (arg), strict, explain_p);
16528 if (TREE_CODE (arg) != POINTER_TYPE)
16529 return unify_type_mismatch (explain_p, parm, arg);
16531 /* [temp.deduct.call]
16533 A can be another pointer or pointer to member type that can
16534 be converted to the deduced A via a qualification
16535 conversion (_conv.qual_).
16537 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
16538 This will allow for additional cv-qualification of the
16539 pointed-to types if appropriate. */
16541 if (TREE_CODE (TREE_TYPE (arg)) == RECORD_TYPE)
16542 /* The derived-to-base conversion only persists through one
16543 level of pointers. */
16544 strict |= (strict_in & UNIFY_ALLOW_DERIVED);
16546 return unify (tparms, targs, TREE_TYPE (parm),
16547 TREE_TYPE (arg), strict, explain_p);
16550 case REFERENCE_TYPE:
16551 if (TREE_CODE (arg) != REFERENCE_TYPE)
16552 return unify_type_mismatch (explain_p, parm, arg);
16553 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
16554 strict & UNIFY_ALLOW_MORE_CV_QUAL, explain_p);
16557 if (TREE_CODE (arg) != ARRAY_TYPE)
16558 return unify_type_mismatch (explain_p, parm, arg);
16559 if ((TYPE_DOMAIN (parm) == NULL_TREE)
16560 != (TYPE_DOMAIN (arg) == NULL_TREE))
16561 return unify_type_mismatch (explain_p, parm, arg);
16562 if (TYPE_DOMAIN (parm) != NULL_TREE)
16569 /* Our representation of array types uses "N - 1" as the
16570 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
16571 not an integer constant. We cannot unify arbitrarily
16572 complex expressions, so we eliminate the MINUS_EXPRs
16574 parm_max = TYPE_MAX_VALUE (TYPE_DOMAIN (parm));
16575 parm_cst = TREE_CODE (parm_max) == INTEGER_CST;
16578 gcc_assert (TREE_CODE (parm_max) == MINUS_EXPR);
16579 parm_max = TREE_OPERAND (parm_max, 0);
16581 arg_max = TYPE_MAX_VALUE (TYPE_DOMAIN (arg));
16582 arg_cst = TREE_CODE (arg_max) == INTEGER_CST;
16585 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
16586 trying to unify the type of a variable with the type
16587 of a template parameter. For example:
16589 template <unsigned int N>
16590 void f (char (&) [N]);
16597 Here, the type of the ARG will be "int [g(i)]", and
16598 may be a SAVE_EXPR, etc. */
16599 if (TREE_CODE (arg_max) != MINUS_EXPR)
16600 return unify_vla_arg (explain_p, arg);
16601 arg_max = TREE_OPERAND (arg_max, 0);
16604 /* If only one of the bounds used a MINUS_EXPR, compensate
16605 by adding one to the other bound. */
16606 if (parm_cst && !arg_cst)
16607 parm_max = fold_build2_loc (input_location, PLUS_EXPR,
16611 else if (arg_cst && !parm_cst)
16612 arg_max = fold_build2_loc (input_location, PLUS_EXPR,
16617 RECUR_AND_CHECK_FAILURE (tparms, targs, parm_max, arg_max,
16618 UNIFY_ALLOW_INTEGER, explain_p);
16620 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
16621 strict & UNIFY_ALLOW_MORE_CV_QUAL, explain_p);
16628 case ENUMERAL_TYPE:
16631 if (TREE_CODE (arg) != TREE_CODE (parm))
16632 return unify_type_mismatch (explain_p, parm, arg);
16634 /* We have already checked cv-qualification at the top of the
16636 if (!same_type_ignoring_top_level_qualifiers_p (arg, parm))
16637 return unify_type_mismatch (explain_p, parm, arg);
16639 /* As far as unification is concerned, this wins. Later checks
16640 will invalidate it if necessary. */
16641 return unify_success (explain_p);
16643 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
16644 /* Type INTEGER_CST can come from ordinary constant template args. */
16646 while (TREE_CODE (arg) == NOP_EXPR)
16647 arg = TREE_OPERAND (arg, 0);
16649 if (TREE_CODE (arg) != INTEGER_CST)
16650 return unify_template_argument_mismatch (explain_p, parm, arg);
16651 return (tree_int_cst_equal (parm, arg)
16652 ? unify_success (explain_p)
16653 : unify_template_argument_mismatch (explain_p, parm, arg));
16657 int i, len, argslen;
16658 int parm_variadic_p = 0;
16660 if (TREE_CODE (arg) != TREE_VEC)
16661 return unify_template_argument_mismatch (explain_p, parm, arg);
16663 len = TREE_VEC_LENGTH (parm);
16664 argslen = TREE_VEC_LENGTH (arg);
16666 /* Check for pack expansions in the parameters. */
16667 for (i = 0; i < len; ++i)
16669 if (PACK_EXPANSION_P (TREE_VEC_ELT (parm, i)))
16672 /* We can unify against something with a trailing
16674 parm_variadic_p = 1;
16676 /* [temp.deduct.type]/9: If the template argument list of
16677 P contains a pack expansion that is not the last
16678 template argument, the entire template argument list
16679 is a non-deduced context. */
16680 return unify_success (explain_p);
16684 /* If we don't have enough arguments to satisfy the parameters
16685 (not counting the pack expression at the end), or we have
16686 too many arguments for a parameter list that doesn't end in
16687 a pack expression, we can't unify. */
16688 if (parm_variadic_p
16689 ? argslen < len - parm_variadic_p
16691 return unify_arity (explain_p, TREE_VEC_LENGTH (arg), len);
16693 /* Unify all of the parameters that precede the (optional)
16694 pack expression. */
16695 for (i = 0; i < len - parm_variadic_p; ++i)
16697 RECUR_AND_CHECK_FAILURE (tparms, targs,
16698 TREE_VEC_ELT (parm, i),
16699 TREE_VEC_ELT (arg, i),
16700 UNIFY_ALLOW_NONE, explain_p);
16702 if (parm_variadic_p)
16703 return unify_pack_expansion (tparms, targs, parm, arg,
16705 /*subr=*/true, explain_p);
16706 return unify_success (explain_p);
16711 if (TREE_CODE (arg) != TREE_CODE (parm))
16712 return unify_type_mismatch (explain_p, parm, arg);
16714 if (TYPE_PTRMEMFUNC_P (parm))
16716 if (!TYPE_PTRMEMFUNC_P (arg))
16717 return unify_type_mismatch (explain_p, parm, arg);
16719 return unify (tparms, targs,
16720 TYPE_PTRMEMFUNC_FN_TYPE (parm),
16721 TYPE_PTRMEMFUNC_FN_TYPE (arg),
16722 strict, explain_p);
16725 if (CLASSTYPE_TEMPLATE_INFO (parm))
16727 tree t = NULL_TREE;
16729 if (strict_in & UNIFY_ALLOW_DERIVED)
16731 /* First, we try to unify the PARM and ARG directly. */
16732 t = try_class_unification (tparms, targs,
16733 parm, arg, explain_p);
16737 /* Fallback to the special case allowed in
16738 [temp.deduct.call]:
16740 If P is a class, and P has the form
16741 template-id, then A can be a derived class of
16742 the deduced A. Likewise, if P is a pointer to
16743 a class of the form template-id, A can be a
16744 pointer to a derived class pointed to by the
16746 enum template_base_result r;
16747 r = get_template_base (tparms, targs, parm, arg,
16751 return unify_no_common_base (explain_p, r, parm, arg);
16754 else if (CLASSTYPE_TEMPLATE_INFO (arg)
16755 && (CLASSTYPE_TI_TEMPLATE (parm)
16756 == CLASSTYPE_TI_TEMPLATE (arg)))
16757 /* Perhaps PARM is something like S<U> and ARG is S<int>.
16758 Then, we should unify `int' and `U'. */
16761 /* There's no chance of unification succeeding. */
16762 return unify_type_mismatch (explain_p, parm, arg);
16764 return unify (tparms, targs, CLASSTYPE_TI_ARGS (parm),
16765 CLASSTYPE_TI_ARGS (t), UNIFY_ALLOW_NONE, explain_p);
16767 else if (!same_type_ignoring_top_level_qualifiers_p (parm, arg))
16768 return unify_type_mismatch (explain_p, parm, arg);
16769 return unify_success (explain_p);
16772 case FUNCTION_TYPE:
16774 unsigned int nargs;
16779 if (TREE_CODE (arg) != TREE_CODE (parm))
16780 return unify_type_mismatch (explain_p, parm, arg);
16782 /* CV qualifications for methods can never be deduced, they must
16783 match exactly. We need to check them explicitly here,
16784 because type_unification_real treats them as any other
16785 cv-qualified parameter. */
16786 if (TREE_CODE (parm) == METHOD_TYPE
16787 && (!check_cv_quals_for_unify
16789 class_of_this_parm (arg),
16790 class_of_this_parm (parm))))
16791 return unify_cv_qual_mismatch (explain_p, parm, arg);
16793 RECUR_AND_CHECK_FAILURE (tparms, targs, TREE_TYPE (parm),
16794 TREE_TYPE (arg), UNIFY_ALLOW_NONE, explain_p);
16796 nargs = list_length (TYPE_ARG_TYPES (arg));
16797 args = XALLOCAVEC (tree, nargs);
16798 for (a = TYPE_ARG_TYPES (arg), i = 0;
16799 a != NULL_TREE && a != void_list_node;
16800 a = TREE_CHAIN (a), ++i)
16801 args[i] = TREE_VALUE (a);
16804 return type_unification_real (tparms, targs, TYPE_ARG_TYPES (parm),
16805 args, nargs, 1, DEDUCE_EXACT,
16806 LOOKUP_NORMAL, explain_p);
16810 /* Unify a pointer to member with a pointer to member function, which
16811 deduces the type of the member as a function type. */
16812 if (TYPE_PTRMEMFUNC_P (arg))
16817 /* Check top-level cv qualifiers */
16818 if (!check_cv_quals_for_unify (UNIFY_ALLOW_NONE, arg, parm))
16819 return unify_cv_qual_mismatch (explain_p, parm, arg);
16821 RECUR_AND_CHECK_FAILURE (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
16822 TYPE_PTRMEMFUNC_OBJECT_TYPE (arg),
16823 UNIFY_ALLOW_NONE, explain_p);
16825 /* Determine the type of the function we are unifying against. */
16826 method_type = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (arg));
16828 build_function_type (TREE_TYPE (method_type),
16829 TREE_CHAIN (TYPE_ARG_TYPES (method_type)));
16831 /* Extract the cv-qualifiers of the member function from the
16832 implicit object parameter and place them on the function
16833 type to be restored later. */
16834 fntype = apply_memfn_quals (fntype, type_memfn_quals (method_type));
16835 return unify (tparms, targs, TREE_TYPE (parm), fntype, strict, explain_p);
16838 if (TREE_CODE (arg) != OFFSET_TYPE)
16839 return unify_type_mismatch (explain_p, parm, arg);
16840 RECUR_AND_CHECK_FAILURE (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
16841 TYPE_OFFSET_BASETYPE (arg),
16842 UNIFY_ALLOW_NONE, explain_p);
16843 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
16844 strict, explain_p);
16847 if (DECL_TEMPLATE_PARM_P (parm))
16848 return unify (tparms, targs, DECL_INITIAL (parm), arg, strict, explain_p);
16849 if (arg != integral_constant_value (parm))
16850 return unify_template_argument_mismatch (explain_p, parm, arg);
16851 return unify_success (explain_p);
16854 case TEMPLATE_DECL:
16855 /* Matched cases are handled by the ARG == PARM test above. */
16856 return unify_template_argument_mismatch (explain_p, parm, arg);
16859 /* A non-type template parameter that is a variable should be a
16860 an integral constant, in which case, it whould have been
16861 folded into its (constant) value. So we should not be getting
16862 a variable here. */
16863 gcc_unreachable ();
16865 case TYPE_ARGUMENT_PACK:
16866 case NONTYPE_ARGUMENT_PACK:
16867 return unify (tparms, targs, ARGUMENT_PACK_ARGS (parm),
16868 ARGUMENT_PACK_ARGS (arg), strict, explain_p);
16871 case DECLTYPE_TYPE:
16872 case UNDERLYING_TYPE:
16873 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
16874 or UNDERLYING_TYPE nodes. */
16875 return unify_success (explain_p);
16878 /* Unification fails if we hit an error node. */
16879 return unify_invalid (explain_p);
16882 /* An unresolved overload is a nondeduced context. */
16883 if (type_unknown_p (parm))
16884 return unify_success (explain_p);
16885 gcc_assert (EXPR_P (parm));
16887 /* We must be looking at an expression. This can happen with
16891 void foo(S<I>, S<I + 2>);
16893 This is a "nondeduced context":
16897 The nondeduced contexts are:
16899 --A type that is a template-id in which one or more of
16900 the template-arguments is an expression that references
16901 a template-parameter.
16903 In these cases, we assume deduction succeeded, but don't
16904 actually infer any unifications. */
16906 if (!uses_template_parms (parm)
16907 && !template_args_equal (parm, arg))
16908 return unify_expression_unequal (explain_p, parm, arg);
16910 return unify_success (explain_p);
16913 #undef RECUR_AND_CHECK_FAILURE
16915 /* Note that DECL can be defined in this translation unit, if
16919 mark_definable (tree decl)
16922 DECL_NOT_REALLY_EXTERN (decl) = 1;
16923 FOR_EACH_CLONE (clone, decl)
16924 DECL_NOT_REALLY_EXTERN (clone) = 1;
16927 /* Called if RESULT is explicitly instantiated, or is a member of an
16928 explicitly instantiated class. */
16931 mark_decl_instantiated (tree result, int extern_p)
16933 SET_DECL_EXPLICIT_INSTANTIATION (result);
16935 /* If this entity has already been written out, it's too late to
16936 make any modifications. */
16937 if (TREE_ASM_WRITTEN (result))
16940 if (TREE_CODE (result) != FUNCTION_DECL)
16941 /* The TREE_PUBLIC flag for function declarations will have been
16942 set correctly by tsubst. */
16943 TREE_PUBLIC (result) = 1;
16945 /* This might have been set by an earlier implicit instantiation. */
16946 DECL_COMDAT (result) = 0;
16949 DECL_NOT_REALLY_EXTERN (result) = 0;
16952 mark_definable (result);
16953 /* Always make artificials weak. */
16954 if (DECL_ARTIFICIAL (result) && flag_weak)
16955 comdat_linkage (result);
16956 /* For WIN32 we also want to put explicit instantiations in
16957 linkonce sections. */
16958 else if (TREE_PUBLIC (result))
16959 maybe_make_one_only (result);
16962 /* If EXTERN_P, then this function will not be emitted -- unless
16963 followed by an explicit instantiation, at which point its linkage
16964 will be adjusted. If !EXTERN_P, then this function will be
16965 emitted here. In neither circumstance do we want
16966 import_export_decl to adjust the linkage. */
16967 DECL_INTERFACE_KNOWN (result) = 1;
16970 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
16971 important template arguments. If any are missing, we check whether
16972 they're important by using error_mark_node for substituting into any
16973 args that were used for partial ordering (the ones between ARGS and END)
16974 and seeing if it bubbles up. */
16977 check_undeduced_parms (tree targs, tree args, tree end)
16979 bool found = false;
16981 for (i = TREE_VEC_LENGTH (targs) - 1; i >= 0; --i)
16982 if (TREE_VEC_ELT (targs, i) == NULL_TREE)
16985 TREE_VEC_ELT (targs, i) = error_mark_node;
16989 for (; args != end; args = TREE_CHAIN (args))
16991 tree substed = tsubst (TREE_VALUE (args), targs, tf_none, NULL_TREE);
16992 if (substed == error_mark_node)
16999 /* Given two function templates PAT1 and PAT2, return:
17001 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
17002 -1 if PAT2 is more specialized than PAT1.
17003 0 if neither is more specialized.
17005 LEN indicates the number of parameters we should consider
17006 (defaulted parameters should not be considered).
17008 The 1998 std underspecified function template partial ordering, and
17009 DR214 addresses the issue. We take pairs of arguments, one from
17010 each of the templates, and deduce them against each other. One of
17011 the templates will be more specialized if all the *other*
17012 template's arguments deduce against its arguments and at least one
17013 of its arguments *does* *not* deduce against the other template's
17014 corresponding argument. Deduction is done as for class templates.
17015 The arguments used in deduction have reference and top level cv
17016 qualifiers removed. Iff both arguments were originally reference
17017 types *and* deduction succeeds in both directions, the template
17018 with the more cv-qualified argument wins for that pairing (if
17019 neither is more cv-qualified, they both are equal). Unlike regular
17020 deduction, after all the arguments have been deduced in this way,
17021 we do *not* verify the deduced template argument values can be
17022 substituted into non-deduced contexts.
17024 The logic can be a bit confusing here, because we look at deduce1 and
17025 targs1 to see if pat2 is at least as specialized, and vice versa; if we
17026 can find template arguments for pat1 to make arg1 look like arg2, that
17027 means that arg2 is at least as specialized as arg1. */
17030 more_specialized_fn (tree pat1, tree pat2, int len)
17032 tree decl1 = DECL_TEMPLATE_RESULT (pat1);
17033 tree decl2 = DECL_TEMPLATE_RESULT (pat2);
17034 tree targs1 = make_tree_vec (DECL_NTPARMS (pat1));
17035 tree targs2 = make_tree_vec (DECL_NTPARMS (pat2));
17036 tree tparms1 = DECL_INNERMOST_TEMPLATE_PARMS (pat1);
17037 tree tparms2 = DECL_INNERMOST_TEMPLATE_PARMS (pat2);
17038 tree args1 = TYPE_ARG_TYPES (TREE_TYPE (decl1));
17039 tree args2 = TYPE_ARG_TYPES (TREE_TYPE (decl2));
17040 tree origs1, origs2;
17041 bool lose1 = false;
17042 bool lose2 = false;
17044 /* Remove the this parameter from non-static member functions. If
17045 one is a non-static member function and the other is not a static
17046 member function, remove the first parameter from that function
17047 also. This situation occurs for operator functions where we
17048 locate both a member function (with this pointer) and non-member
17049 operator (with explicit first operand). */
17050 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl1))
17052 len--; /* LEN is the number of significant arguments for DECL1 */
17053 args1 = TREE_CHAIN (args1);
17054 if (!DECL_STATIC_FUNCTION_P (decl2))
17055 args2 = TREE_CHAIN (args2);
17057 else if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl2))
17059 args2 = TREE_CHAIN (args2);
17060 if (!DECL_STATIC_FUNCTION_P (decl1))
17063 args1 = TREE_CHAIN (args1);
17067 /* If only one is a conversion operator, they are unordered. */
17068 if (DECL_CONV_FN_P (decl1) != DECL_CONV_FN_P (decl2))
17071 /* Consider the return type for a conversion function */
17072 if (DECL_CONV_FN_P (decl1))
17074 args1 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl1)), args1);
17075 args2 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl2)), args2);
17079 processing_template_decl++;
17085 /* Stop when an ellipsis is seen. */
17086 && args1 != NULL_TREE && args2 != NULL_TREE)
17088 tree arg1 = TREE_VALUE (args1);
17089 tree arg2 = TREE_VALUE (args2);
17090 int deduce1, deduce2;
17094 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
17095 && TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
17097 /* When both arguments are pack expansions, we need only
17098 unify the patterns themselves. */
17099 arg1 = PACK_EXPANSION_PATTERN (arg1);
17100 arg2 = PACK_EXPANSION_PATTERN (arg2);
17102 /* This is the last comparison we need to do. */
17106 if (TREE_CODE (arg1) == REFERENCE_TYPE)
17108 arg1 = TREE_TYPE (arg1);
17109 quals1 = cp_type_quals (arg1);
17112 if (TREE_CODE (arg2) == REFERENCE_TYPE)
17114 arg2 = TREE_TYPE (arg2);
17115 quals2 = cp_type_quals (arg2);
17118 if ((quals1 < 0) != (quals2 < 0))
17120 /* Only of the args is a reference, see if we should apply
17121 array/function pointer decay to it. This is not part of
17122 DR214, but is, IMHO, consistent with the deduction rules
17123 for the function call itself, and with our earlier
17124 implementation of the underspecified partial ordering
17125 rules. (nathan). */
17128 switch (TREE_CODE (arg1))
17131 arg1 = TREE_TYPE (arg1);
17133 case FUNCTION_TYPE:
17134 arg1 = build_pointer_type (arg1);
17143 switch (TREE_CODE (arg2))
17146 arg2 = TREE_TYPE (arg2);
17148 case FUNCTION_TYPE:
17149 arg2 = build_pointer_type (arg2);
17158 arg1 = TYPE_MAIN_VARIANT (arg1);
17159 arg2 = TYPE_MAIN_VARIANT (arg2);
17161 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION)
17163 int i, len2 = list_length (args2);
17164 tree parmvec = make_tree_vec (1);
17165 tree argvec = make_tree_vec (len2);
17168 /* Setup the parameter vector, which contains only ARG1. */
17169 TREE_VEC_ELT (parmvec, 0) = arg1;
17171 /* Setup the argument vector, which contains the remaining
17173 for (i = 0; i < len2; i++, ta = TREE_CHAIN (ta))
17174 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
17176 deduce1 = (unify_pack_expansion (tparms1, targs1, parmvec,
17177 argvec, DEDUCE_EXACT,
17178 /*subr=*/true, /*explain_p=*/false)
17181 /* We cannot deduce in the other direction, because ARG1 is
17182 a pack expansion but ARG2 is not. */
17185 else if (TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
17187 int i, len1 = list_length (args1);
17188 tree parmvec = make_tree_vec (1);
17189 tree argvec = make_tree_vec (len1);
17192 /* Setup the parameter vector, which contains only ARG1. */
17193 TREE_VEC_ELT (parmvec, 0) = arg2;
17195 /* Setup the argument vector, which contains the remaining
17197 for (i = 0; i < len1; i++, ta = TREE_CHAIN (ta))
17198 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
17200 deduce2 = (unify_pack_expansion (tparms2, targs2, parmvec,
17201 argvec, DEDUCE_EXACT,
17202 /*subr=*/true, /*explain_p=*/false)
17205 /* We cannot deduce in the other direction, because ARG2 is
17206 a pack expansion but ARG1 is not.*/
17212 /* The normal case, where neither argument is a pack
17214 deduce1 = (unify (tparms1, targs1, arg1, arg2,
17215 UNIFY_ALLOW_NONE, /*explain_p=*/false)
17217 deduce2 = (unify (tparms2, targs2, arg2, arg1,
17218 UNIFY_ALLOW_NONE, /*explain_p=*/false)
17222 /* If we couldn't deduce arguments for tparms1 to make arg1 match
17223 arg2, then arg2 is not as specialized as arg1. */
17229 /* "If, for a given type, deduction succeeds in both directions
17230 (i.e., the types are identical after the transformations above)
17231 and if the type from the argument template is more cv-qualified
17232 than the type from the parameter template (as described above)
17233 that type is considered to be more specialized than the other. If
17234 neither type is more cv-qualified than the other then neither type
17235 is more specialized than the other." */
17237 if (deduce1 && deduce2
17238 && quals1 != quals2 && quals1 >= 0 && quals2 >= 0)
17240 if ((quals1 & quals2) == quals2)
17242 if ((quals1 & quals2) == quals1)
17246 if (lose1 && lose2)
17247 /* We've failed to deduce something in either direction.
17248 These must be unordered. */
17251 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
17252 || TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
17253 /* We have already processed all of the arguments in our
17254 handing of the pack expansion type. */
17257 args1 = TREE_CHAIN (args1);
17258 args2 = TREE_CHAIN (args2);
17261 /* "In most cases, all template parameters must have values in order for
17262 deduction to succeed, but for partial ordering purposes a template
17263 parameter may remain without a value provided it is not used in the
17264 types being used for partial ordering."
17266 Thus, if we are missing any of the targs1 we need to substitute into
17267 origs1, then pat2 is not as specialized as pat1. This can happen when
17268 there is a nondeduced context. */
17269 if (!lose2 && check_undeduced_parms (targs1, origs1, args1))
17271 if (!lose1 && check_undeduced_parms (targs2, origs2, args2))
17274 processing_template_decl--;
17276 /* All things being equal, if the next argument is a pack expansion
17277 for one function but not for the other, prefer the
17278 non-variadic function. FIXME this is bogus; see c++/41958. */
17280 && args1 && TREE_VALUE (args1)
17281 && args2 && TREE_VALUE (args2))
17283 lose1 = TREE_CODE (TREE_VALUE (args1)) == TYPE_PACK_EXPANSION;
17284 lose2 = TREE_CODE (TREE_VALUE (args2)) == TYPE_PACK_EXPANSION;
17287 if (lose1 == lose2)
17295 /* Determine which of two partial specializations is more specialized.
17297 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
17298 to the first partial specialization. The TREE_VALUE is the
17299 innermost set of template parameters for the partial
17300 specialization. PAT2 is similar, but for the second template.
17302 Return 1 if the first partial specialization is more specialized;
17303 -1 if the second is more specialized; 0 if neither is more
17306 See [temp.class.order] for information about determining which of
17307 two templates is more specialized. */
17310 more_specialized_class (tree pat1, tree pat2)
17315 bool any_deductions = false;
17317 tmpl1 = TREE_TYPE (pat1);
17318 tmpl2 = TREE_TYPE (pat2);
17320 /* Just like what happens for functions, if we are ordering between
17321 different class template specializations, we may encounter dependent
17322 types in the arguments, and we need our dependency check functions
17323 to behave correctly. */
17324 ++processing_template_decl;
17325 targs = get_class_bindings (TREE_VALUE (pat1),
17326 CLASSTYPE_TI_ARGS (tmpl1),
17327 CLASSTYPE_TI_ARGS (tmpl2));
17331 any_deductions = true;
17334 targs = get_class_bindings (TREE_VALUE (pat2),
17335 CLASSTYPE_TI_ARGS (tmpl2),
17336 CLASSTYPE_TI_ARGS (tmpl1));
17340 any_deductions = true;
17342 --processing_template_decl;
17344 /* In the case of a tie where at least one of the class templates
17345 has a parameter pack at the end, the template with the most
17346 non-packed parameters wins. */
17349 && (template_args_variadic_p (TREE_PURPOSE (pat1))
17350 || template_args_variadic_p (TREE_PURPOSE (pat2))))
17352 tree args1 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat1));
17353 tree args2 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat2));
17354 int len1 = TREE_VEC_LENGTH (args1);
17355 int len2 = TREE_VEC_LENGTH (args2);
17357 /* We don't count the pack expansion at the end. */
17358 if (template_args_variadic_p (TREE_PURPOSE (pat1)))
17360 if (template_args_variadic_p (TREE_PURPOSE (pat2)))
17365 else if (len1 < len2)
17372 /* Return the template arguments that will produce the function signature
17373 DECL from the function template FN, with the explicit template
17374 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
17375 also match. Return NULL_TREE if no satisfactory arguments could be
17379 get_bindings (tree fn, tree decl, tree explicit_args, bool check_rettype)
17381 int ntparms = DECL_NTPARMS (fn);
17382 tree targs = make_tree_vec (ntparms);
17384 tree decl_arg_types;
17386 unsigned int nargs, ix;
17389 /* Substitute the explicit template arguments into the type of DECL.
17390 The call to fn_type_unification will handle substitution into the
17392 decl_type = TREE_TYPE (decl);
17393 if (explicit_args && uses_template_parms (decl_type))
17396 tree converted_args;
17398 if (DECL_TEMPLATE_INFO (decl))
17399 tmpl = DECL_TI_TEMPLATE (decl);
17401 /* We can get here for some invalid specializations. */
17405 = coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
17406 explicit_args, NULL_TREE,
17408 /*require_all_args=*/false,
17409 /*use_default_args=*/false);
17410 if (converted_args == error_mark_node)
17413 decl_type = tsubst (decl_type, converted_args, tf_none, NULL_TREE);
17414 if (decl_type == error_mark_node)
17418 /* Never do unification on the 'this' parameter. */
17419 decl_arg_types = skip_artificial_parms_for (decl,
17420 TYPE_ARG_TYPES (decl_type));
17422 nargs = list_length (decl_arg_types);
17423 args = XALLOCAVEC (tree, nargs);
17424 for (arg = decl_arg_types, ix = 0;
17425 arg != NULL_TREE && arg != void_list_node;
17426 arg = TREE_CHAIN (arg), ++ix)
17427 args[ix] = TREE_VALUE (arg);
17429 if (fn_type_unification (fn, explicit_args, targs,
17431 (check_rettype || DECL_CONV_FN_P (fn)
17432 ? TREE_TYPE (decl_type) : NULL_TREE),
17433 DEDUCE_EXACT, LOOKUP_NORMAL, /*explain_p=*/false))
17439 /* Return the innermost template arguments that, when applied to a
17440 template specialization whose innermost template parameters are
17441 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
17444 For example, suppose we have:
17446 template <class T, class U> struct S {};
17447 template <class T> struct S<T*, int> {};
17449 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
17450 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
17451 int}. The resulting vector will be {double}, indicating that `T'
17452 is bound to `double'. */
17455 get_class_bindings (tree tparms, tree spec_args, tree args)
17457 int i, ntparms = TREE_VEC_LENGTH (tparms);
17459 tree innermost_deduced_args;
17461 innermost_deduced_args = make_tree_vec (ntparms);
17462 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
17464 deduced_args = copy_node (args);
17465 SET_TMPL_ARGS_LEVEL (deduced_args,
17466 TMPL_ARGS_DEPTH (deduced_args),
17467 innermost_deduced_args);
17470 deduced_args = innermost_deduced_args;
17472 if (unify (tparms, deduced_args,
17473 INNERMOST_TEMPLATE_ARGS (spec_args),
17474 INNERMOST_TEMPLATE_ARGS (args),
17475 UNIFY_ALLOW_NONE, /*explain_p=*/false))
17478 for (i = 0; i < ntparms; ++i)
17479 if (! TREE_VEC_ELT (innermost_deduced_args, i))
17482 /* Verify that nondeduced template arguments agree with the type
17483 obtained from argument deduction.
17487 struct A { typedef int X; };
17488 template <class T, class U> struct C {};
17489 template <class T> struct C<T, typename T::X> {};
17491 Then with the instantiation `C<A, int>', we can deduce that
17492 `T' is `A' but unify () does not check whether `typename T::X'
17494 spec_args = tsubst (spec_args, deduced_args, tf_none, NULL_TREE);
17495 if (spec_args == error_mark_node
17496 /* We only need to check the innermost arguments; the other
17497 arguments will always agree. */
17498 || !comp_template_args (INNERMOST_TEMPLATE_ARGS (spec_args),
17499 INNERMOST_TEMPLATE_ARGS (args)))
17502 /* Now that we have bindings for all of the template arguments,
17503 ensure that the arguments deduced for the template template
17504 parameters have compatible template parameter lists. See the use
17505 of template_template_parm_bindings_ok_p in fn_type_unification
17506 for more information. */
17507 if (!template_template_parm_bindings_ok_p (tparms, deduced_args))
17510 return deduced_args;
17513 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
17514 Return the TREE_LIST node with the most specialized template, if
17515 any. If there is no most specialized template, the error_mark_node
17518 Note that this function does not look at, or modify, the
17519 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
17520 returned is one of the elements of INSTANTIATIONS, callers may
17521 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
17522 and retrieve it from the value returned. */
17525 most_specialized_instantiation (tree templates)
17529 ++processing_template_decl;
17532 for (fn = TREE_CHAIN (templates); fn; fn = TREE_CHAIN (fn))
17536 if (get_bindings (TREE_VALUE (champ),
17537 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
17538 NULL_TREE, /*check_ret=*/true))
17541 if (get_bindings (TREE_VALUE (fn),
17542 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
17543 NULL_TREE, /*check_ret=*/true))
17550 /* Equally specialized, move to next function. If there
17551 is no next function, nothing's most specialized. */
17552 fn = TREE_CHAIN (fn);
17560 /* Now verify that champ is better than everything earlier in the
17561 instantiation list. */
17562 for (fn = templates; fn != champ; fn = TREE_CHAIN (fn))
17563 if (get_bindings (TREE_VALUE (champ),
17564 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
17565 NULL_TREE, /*check_ret=*/true)
17566 || !get_bindings (TREE_VALUE (fn),
17567 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
17568 NULL_TREE, /*check_ret=*/true))
17574 processing_template_decl--;
17577 return error_mark_node;
17582 /* If DECL is a specialization of some template, return the most
17583 general such template. Otherwise, returns NULL_TREE.
17585 For example, given:
17587 template <class T> struct S { template <class U> void f(U); };
17589 if TMPL is `template <class U> void S<int>::f(U)' this will return
17590 the full template. This function will not trace past partial
17591 specializations, however. For example, given in addition:
17593 template <class T> struct S<T*> { template <class U> void f(U); };
17595 if TMPL is `template <class U> void S<int*>::f(U)' this will return
17596 `template <class T> template <class U> S<T*>::f(U)'. */
17599 most_general_template (tree decl)
17601 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
17602 an immediate specialization. */
17603 if (TREE_CODE (decl) == FUNCTION_DECL)
17605 if (DECL_TEMPLATE_INFO (decl)) {
17606 decl = DECL_TI_TEMPLATE (decl);
17608 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
17609 template friend. */
17610 if (TREE_CODE (decl) != TEMPLATE_DECL)
17616 /* Look for more and more general templates. */
17617 while (DECL_TEMPLATE_INFO (decl))
17619 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
17620 (See cp-tree.h for details.) */
17621 if (TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
17624 if (CLASS_TYPE_P (TREE_TYPE (decl))
17625 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)))
17628 /* Stop if we run into an explicitly specialized class template. */
17629 if (!DECL_NAMESPACE_SCOPE_P (decl)
17630 && DECL_CONTEXT (decl)
17631 && CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (decl)))
17634 decl = DECL_TI_TEMPLATE (decl);
17640 /* Return the most specialized of the class template partial
17641 specializations of TMPL which can produce TYPE, a specialization of
17642 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
17643 a _TYPE node corresponding to the partial specialization, while the
17644 TREE_PURPOSE is the set of template arguments that must be
17645 substituted into the TREE_TYPE in order to generate TYPE.
17647 If the choice of partial specialization is ambiguous, a diagnostic
17648 is issued, and the error_mark_node is returned. If there are no
17649 partial specializations of TMPL matching TYPE, then NULL_TREE is
17653 most_specialized_class (tree type, tree tmpl, tsubst_flags_t complain)
17655 tree list = NULL_TREE;
17661 tree outer_args = NULL_TREE;
17663 tmpl = most_general_template (tmpl);
17664 args = CLASSTYPE_TI_ARGS (type);
17666 /* For determining which partial specialization to use, only the
17667 innermost args are interesting. */
17668 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
17670 outer_args = strip_innermost_template_args (args, 1);
17671 args = INNERMOST_TEMPLATE_ARGS (args);
17674 for (t = DECL_TEMPLATE_SPECIALIZATIONS (tmpl); t; t = TREE_CHAIN (t))
17676 tree partial_spec_args;
17678 tree parms = TREE_VALUE (t);
17680 partial_spec_args = CLASSTYPE_TI_ARGS (TREE_TYPE (t));
17682 ++processing_template_decl;
17688 /* Discard the outer levels of args, and then substitute in the
17689 template args from the enclosing class. */
17690 partial_spec_args = INNERMOST_TEMPLATE_ARGS (partial_spec_args);
17691 partial_spec_args = tsubst_template_args
17692 (partial_spec_args, outer_args, tf_none, NULL_TREE);
17694 /* PARMS already refers to just the innermost parms, but the
17695 template parms in partial_spec_args had their levels lowered
17696 by tsubst, so we need to do the same for the parm list. We
17697 can't just tsubst the TREE_VEC itself, as tsubst wants to
17698 treat a TREE_VEC as an argument vector. */
17699 parms = copy_node (parms);
17700 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
17701 TREE_VEC_ELT (parms, i) =
17702 tsubst (TREE_VEC_ELT (parms, i), outer_args, tf_none, NULL_TREE);
17706 partial_spec_args =
17707 coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
17708 add_to_template_args (outer_args,
17709 partial_spec_args),
17711 /*require_all_args=*/true,
17712 /*use_default_args=*/true);
17714 --processing_template_decl;
17716 if (partial_spec_args == error_mark_node)
17717 return error_mark_node;
17719 spec_args = get_class_bindings (parms,
17725 spec_args = add_to_template_args (outer_args, spec_args);
17726 list = tree_cons (spec_args, TREE_VALUE (t), list);
17727 TREE_TYPE (list) = TREE_TYPE (t);
17734 ambiguous_p = false;
17737 t = TREE_CHAIN (t);
17738 for (; t; t = TREE_CHAIN (t))
17740 fate = more_specialized_class (champ, t);
17747 t = TREE_CHAIN (t);
17750 ambiguous_p = true;
17759 for (t = list; t && t != champ; t = TREE_CHAIN (t))
17761 fate = more_specialized_class (champ, t);
17764 ambiguous_p = true;
17772 char *spaces = NULL;
17773 if (!(complain & tf_error))
17774 return error_mark_node;
17775 error ("ambiguous class template instantiation for %q#T", type);
17776 str = ngettext ("candidate is:", "candidates are:", list_length (list));
17777 for (t = list; t; t = TREE_CHAIN (t))
17779 error ("%s %+#T", spaces ? spaces : str, TREE_TYPE (t));
17780 spaces = spaces ? spaces : get_spaces (str);
17783 return error_mark_node;
17789 /* Explicitly instantiate DECL. */
17792 do_decl_instantiation (tree decl, tree storage)
17794 tree result = NULL_TREE;
17797 if (!decl || decl == error_mark_node)
17798 /* An error occurred, for which grokdeclarator has already issued
17799 an appropriate message. */
17801 else if (! DECL_LANG_SPECIFIC (decl))
17803 error ("explicit instantiation of non-template %q#D", decl);
17806 else if (TREE_CODE (decl) == VAR_DECL)
17808 /* There is an asymmetry here in the way VAR_DECLs and
17809 FUNCTION_DECLs are handled by grokdeclarator. In the case of
17810 the latter, the DECL we get back will be marked as a
17811 template instantiation, and the appropriate
17812 DECL_TEMPLATE_INFO will be set up. This does not happen for
17813 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
17814 should handle VAR_DECLs as it currently handles
17816 if (!DECL_CLASS_SCOPE_P (decl))
17818 error ("%qD is not a static data member of a class template", decl);
17821 result = lookup_field (DECL_CONTEXT (decl), DECL_NAME (decl), 0, false);
17822 if (!result || TREE_CODE (result) != VAR_DECL)
17824 error ("no matching template for %qD found", decl);
17827 if (!same_type_p (TREE_TYPE (result), TREE_TYPE (decl)))
17829 error ("type %qT for explicit instantiation %qD does not match "
17830 "declared type %qT", TREE_TYPE (result), decl,
17835 else if (TREE_CODE (decl) != FUNCTION_DECL)
17837 error ("explicit instantiation of %q#D", decl);
17843 /* Check for various error cases. Note that if the explicit
17844 instantiation is valid the RESULT will currently be marked as an
17845 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
17846 until we get here. */
17848 if (DECL_TEMPLATE_SPECIALIZATION (result))
17850 /* DR 259 [temp.spec].
17852 Both an explicit instantiation and a declaration of an explicit
17853 specialization shall not appear in a program unless the explicit
17854 instantiation follows a declaration of the explicit specialization.
17856 For a given set of template parameters, if an explicit
17857 instantiation of a template appears after a declaration of an
17858 explicit specialization for that template, the explicit
17859 instantiation has no effect. */
17862 else if (DECL_EXPLICIT_INSTANTIATION (result))
17866 No program shall explicitly instantiate any template more
17869 We check DECL_NOT_REALLY_EXTERN so as not to complain when
17870 the first instantiation was `extern' and the second is not,
17871 and EXTERN_P for the opposite case. */
17872 if (DECL_NOT_REALLY_EXTERN (result) && !extern_p)
17873 permerror (input_location, "duplicate explicit instantiation of %q#D", result);
17874 /* If an "extern" explicit instantiation follows an ordinary
17875 explicit instantiation, the template is instantiated. */
17879 else if (!DECL_IMPLICIT_INSTANTIATION (result))
17881 error ("no matching template for %qD found", result);
17884 else if (!DECL_TEMPLATE_INFO (result))
17886 permerror (input_location, "explicit instantiation of non-template %q#D", result);
17890 if (storage == NULL_TREE)
17892 else if (storage == ridpointers[(int) RID_EXTERN])
17894 if (!in_system_header && (cxx_dialect == cxx98))
17895 pedwarn (input_location, OPT_pedantic,
17896 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
17901 error ("storage class %qD applied to template instantiation", storage);
17903 check_explicit_instantiation_namespace (result);
17904 mark_decl_instantiated (result, extern_p);
17906 instantiate_decl (result, /*defer_ok=*/1,
17907 /*expl_inst_class_mem_p=*/false);
17911 mark_class_instantiated (tree t, int extern_p)
17913 SET_CLASSTYPE_EXPLICIT_INSTANTIATION (t);
17914 SET_CLASSTYPE_INTERFACE_KNOWN (t);
17915 CLASSTYPE_INTERFACE_ONLY (t) = extern_p;
17916 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (t)) = extern_p;
17919 CLASSTYPE_DEBUG_REQUESTED (t) = 1;
17920 rest_of_type_compilation (t, 1);
17924 /* Called from do_type_instantiation through binding_table_foreach to
17925 do recursive instantiation for the type bound in ENTRY. */
17927 bt_instantiate_type_proc (binding_entry entry, void *data)
17929 tree storage = *(tree *) data;
17931 if (MAYBE_CLASS_TYPE_P (entry->type)
17932 && !uses_template_parms (CLASSTYPE_TI_ARGS (entry->type)))
17933 do_type_instantiation (TYPE_MAIN_DECL (entry->type), storage, 0);
17936 /* Called from do_type_instantiation to instantiate a member
17937 (a member function or a static member variable) of an
17938 explicitly instantiated class template. */
17940 instantiate_class_member (tree decl, int extern_p)
17942 mark_decl_instantiated (decl, extern_p);
17944 instantiate_decl (decl, /*defer_ok=*/1,
17945 /*expl_inst_class_mem_p=*/true);
17948 /* Perform an explicit instantiation of template class T. STORAGE, if
17949 non-null, is the RID for extern, inline or static. COMPLAIN is
17950 nonzero if this is called from the parser, zero if called recursively,
17951 since the standard is unclear (as detailed below). */
17954 do_type_instantiation (tree t, tree storage, tsubst_flags_t complain)
17959 int previous_instantiation_extern_p = 0;
17961 if (TREE_CODE (t) == TYPE_DECL)
17964 if (! CLASS_TYPE_P (t) || ! CLASSTYPE_TEMPLATE_INFO (t))
17967 (TYPE_TEMPLATE_INFO (t)) ? TYPE_TI_TEMPLATE (t) : NULL;
17969 error ("explicit instantiation of non-class template %qD", tmpl);
17971 error ("explicit instantiation of non-template type %qT", t);
17977 if (!COMPLETE_TYPE_P (t))
17979 if (complain & tf_error)
17980 error ("explicit instantiation of %q#T before definition of template",
17985 if (storage != NULL_TREE)
17987 if (!in_system_header)
17989 if (storage == ridpointers[(int) RID_EXTERN])
17991 if (cxx_dialect == cxx98)
17992 pedwarn (input_location, OPT_pedantic,
17993 "ISO C++ 1998 forbids the use of %<extern%> on "
17994 "explicit instantiations");
17997 pedwarn (input_location, OPT_pedantic,
17998 "ISO C++ forbids the use of %qE"
17999 " on explicit instantiations", storage);
18002 if (storage == ridpointers[(int) RID_INLINE])
18004 else if (storage == ridpointers[(int) RID_EXTERN])
18006 else if (storage == ridpointers[(int) RID_STATIC])
18010 error ("storage class %qD applied to template instantiation",
18016 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (t))
18018 /* DR 259 [temp.spec].
18020 Both an explicit instantiation and a declaration of an explicit
18021 specialization shall not appear in a program unless the explicit
18022 instantiation follows a declaration of the explicit specialization.
18024 For a given set of template parameters, if an explicit
18025 instantiation of a template appears after a declaration of an
18026 explicit specialization for that template, the explicit
18027 instantiation has no effect. */
18030 else if (CLASSTYPE_EXPLICIT_INSTANTIATION (t))
18034 No program shall explicitly instantiate any template more
18037 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
18038 instantiation was `extern'. If EXTERN_P then the second is.
18039 These cases are OK. */
18040 previous_instantiation_extern_p = CLASSTYPE_INTERFACE_ONLY (t);
18042 if (!previous_instantiation_extern_p && !extern_p
18043 && (complain & tf_error))
18044 permerror (input_location, "duplicate explicit instantiation of %q#T", t);
18046 /* If we've already instantiated the template, just return now. */
18047 if (!CLASSTYPE_INTERFACE_ONLY (t))
18051 check_explicit_instantiation_namespace (TYPE_NAME (t));
18052 mark_class_instantiated (t, extern_p);
18060 /* In contrast to implicit instantiation, where only the
18061 declarations, and not the definitions, of members are
18062 instantiated, we have here:
18066 The explicit instantiation of a class template specialization
18067 implies the instantiation of all of its members not
18068 previously explicitly specialized in the translation unit
18069 containing the explicit instantiation.
18071 Of course, we can't instantiate member template classes, since
18072 we don't have any arguments for them. Note that the standard
18073 is unclear on whether the instantiation of the members are
18074 *explicit* instantiations or not. However, the most natural
18075 interpretation is that it should be an explicit instantiation. */
18078 for (tmp = TYPE_METHODS (t); tmp; tmp = DECL_CHAIN (tmp))
18079 if (TREE_CODE (tmp) == FUNCTION_DECL
18080 && DECL_TEMPLATE_INSTANTIATION (tmp))
18081 instantiate_class_member (tmp, extern_p);
18083 for (tmp = TYPE_FIELDS (t); tmp; tmp = DECL_CHAIN (tmp))
18084 if (TREE_CODE (tmp) == VAR_DECL && DECL_TEMPLATE_INSTANTIATION (tmp))
18085 instantiate_class_member (tmp, extern_p);
18087 if (CLASSTYPE_NESTED_UTDS (t))
18088 binding_table_foreach (CLASSTYPE_NESTED_UTDS (t),
18089 bt_instantiate_type_proc, &storage);
18093 /* Given a function DECL, which is a specialization of TMPL, modify
18094 DECL to be a re-instantiation of TMPL with the same template
18095 arguments. TMPL should be the template into which tsubst'ing
18096 should occur for DECL, not the most general template.
18098 One reason for doing this is a scenario like this:
18101 void f(const T&, int i);
18103 void g() { f(3, 7); }
18106 void f(const T& t, const int i) { }
18108 Note that when the template is first instantiated, with
18109 instantiate_template, the resulting DECL will have no name for the
18110 first parameter, and the wrong type for the second. So, when we go
18111 to instantiate the DECL, we regenerate it. */
18114 regenerate_decl_from_template (tree decl, tree tmpl)
18116 /* The arguments used to instantiate DECL, from the most general
18121 args = DECL_TI_ARGS (decl);
18122 code_pattern = DECL_TEMPLATE_RESULT (tmpl);
18124 /* Make sure that we can see identifiers, and compute access
18126 push_access_scope (decl);
18128 if (TREE_CODE (decl) == FUNCTION_DECL)
18136 args_depth = TMPL_ARGS_DEPTH (args);
18137 parms_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
18138 if (args_depth > parms_depth)
18139 args = get_innermost_template_args (args, parms_depth);
18141 specs = tsubst_exception_specification (TREE_TYPE (code_pattern),
18142 args, tf_error, NULL_TREE,
18143 /*defer_ok*/false);
18144 if (specs && specs != error_mark_node)
18145 TREE_TYPE (decl) = build_exception_variant (TREE_TYPE (decl),
18148 /* Merge parameter declarations. */
18149 decl_parm = skip_artificial_parms_for (decl,
18150 DECL_ARGUMENTS (decl));
18152 = skip_artificial_parms_for (code_pattern,
18153 DECL_ARGUMENTS (code_pattern));
18154 while (decl_parm && !FUNCTION_PARAMETER_PACK_P (pattern_parm))
18159 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
18160 DECL_NAME (decl_parm) = DECL_NAME (pattern_parm);
18161 parm_type = tsubst (TREE_TYPE (pattern_parm), args, tf_error,
18163 parm_type = type_decays_to (parm_type);
18164 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
18165 TREE_TYPE (decl_parm) = parm_type;
18166 attributes = DECL_ATTRIBUTES (pattern_parm);
18167 if (DECL_ATTRIBUTES (decl_parm) != attributes)
18169 DECL_ATTRIBUTES (decl_parm) = attributes;
18170 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
18172 decl_parm = DECL_CHAIN (decl_parm);
18173 pattern_parm = DECL_CHAIN (pattern_parm);
18175 /* Merge any parameters that match with the function parameter
18177 if (pattern_parm && FUNCTION_PARAMETER_PACK_P (pattern_parm))
18180 tree expanded_types;
18181 /* Expand the TYPE_PACK_EXPANSION that provides the types for
18182 the parameters in this function parameter pack. */
18183 expanded_types = tsubst_pack_expansion (TREE_TYPE (pattern_parm),
18184 args, tf_error, NULL_TREE);
18185 len = TREE_VEC_LENGTH (expanded_types);
18186 for (i = 0; i < len; i++)
18191 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
18192 /* Rename the parameter to include the index. */
18193 DECL_NAME (decl_parm) =
18194 make_ith_pack_parameter_name (DECL_NAME (pattern_parm), i);
18195 parm_type = TREE_VEC_ELT (expanded_types, i);
18196 parm_type = type_decays_to (parm_type);
18197 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
18198 TREE_TYPE (decl_parm) = parm_type;
18199 attributes = DECL_ATTRIBUTES (pattern_parm);
18200 if (DECL_ATTRIBUTES (decl_parm) != attributes)
18202 DECL_ATTRIBUTES (decl_parm) = attributes;
18203 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
18205 decl_parm = DECL_CHAIN (decl_parm);
18208 /* Merge additional specifiers from the CODE_PATTERN. */
18209 if (DECL_DECLARED_INLINE_P (code_pattern)
18210 && !DECL_DECLARED_INLINE_P (decl))
18211 DECL_DECLARED_INLINE_P (decl) = 1;
18213 else if (TREE_CODE (decl) == VAR_DECL)
18215 DECL_INITIAL (decl) =
18216 tsubst_expr (DECL_INITIAL (code_pattern), args,
18217 tf_error, DECL_TI_TEMPLATE (decl),
18218 /*integral_constant_expression_p=*/false);
18219 if (VAR_HAD_UNKNOWN_BOUND (decl))
18220 TREE_TYPE (decl) = tsubst (TREE_TYPE (code_pattern), args,
18221 tf_error, DECL_TI_TEMPLATE (decl));
18224 gcc_unreachable ();
18226 pop_access_scope (decl);
18229 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
18230 substituted to get DECL. */
18233 template_for_substitution (tree decl)
18235 tree tmpl = DECL_TI_TEMPLATE (decl);
18237 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
18238 for the instantiation. This is not always the most general
18239 template. Consider, for example:
18242 struct S { template <class U> void f();
18243 template <> void f<int>(); };
18245 and an instantiation of S<double>::f<int>. We want TD to be the
18246 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
18247 while (/* An instantiation cannot have a definition, so we need a
18248 more general template. */
18249 DECL_TEMPLATE_INSTANTIATION (tmpl)
18250 /* We must also deal with friend templates. Given:
18252 template <class T> struct S {
18253 template <class U> friend void f() {};
18256 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
18257 so far as the language is concerned, but that's still
18258 where we get the pattern for the instantiation from. On
18259 other hand, if the definition comes outside the class, say:
18261 template <class T> struct S {
18262 template <class U> friend void f();
18264 template <class U> friend void f() {}
18266 we don't need to look any further. That's what the check for
18267 DECL_INITIAL is for. */
18268 || (TREE_CODE (decl) == FUNCTION_DECL
18269 && DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION (tmpl)
18270 && !DECL_INITIAL (DECL_TEMPLATE_RESULT (tmpl))))
18272 /* The present template, TD, should not be a definition. If it
18273 were a definition, we should be using it! Note that we
18274 cannot restructure the loop to just keep going until we find
18275 a template with a definition, since that might go too far if
18276 a specialization was declared, but not defined. */
18277 gcc_assert (TREE_CODE (decl) != VAR_DECL
18278 || DECL_IN_AGGR_P (DECL_TEMPLATE_RESULT (tmpl)));
18280 /* Fetch the more general template. */
18281 tmpl = DECL_TI_TEMPLATE (tmpl);
18287 /* Returns true if we need to instantiate this template instance even if we
18288 know we aren't going to emit it.. */
18291 always_instantiate_p (tree decl)
18293 /* We always instantiate inline functions so that we can inline them. An
18294 explicit instantiation declaration prohibits implicit instantiation of
18295 non-inline functions. With high levels of optimization, we would
18296 normally inline non-inline functions -- but we're not allowed to do
18297 that for "extern template" functions. Therefore, we check
18298 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
18299 return ((TREE_CODE (decl) == FUNCTION_DECL
18300 && DECL_DECLARED_INLINE_P (decl))
18301 /* And we need to instantiate static data members so that
18302 their initializers are available in integral constant
18304 || (TREE_CODE (decl) == VAR_DECL
18305 && decl_maybe_constant_var_p (decl)));
18308 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
18309 instantiate it now, modifying TREE_TYPE (fn). */
18312 maybe_instantiate_noexcept (tree fn)
18314 tree fntype, spec, noex, clone;
18316 if (DECL_CLONED_FUNCTION_P (fn))
18317 fn = DECL_CLONED_FUNCTION (fn);
18318 fntype = TREE_TYPE (fn);
18319 spec = TYPE_RAISES_EXCEPTIONS (fntype);
18321 if (!DEFERRED_NOEXCEPT_SPEC_P (spec))
18324 noex = TREE_PURPOSE (spec);
18326 if (TREE_CODE (noex) == DEFERRED_NOEXCEPT)
18328 if (push_tinst_level (fn))
18330 push_access_scope (fn);
18331 input_location = DECL_SOURCE_LOCATION (fn);
18332 noex = tsubst_copy_and_build (DEFERRED_NOEXCEPT_PATTERN (noex),
18333 DEFERRED_NOEXCEPT_ARGS (noex),
18334 tf_warning_or_error, fn,
18335 /*function_p=*/false,
18336 /*integral_constant_expression_p=*/true);
18337 pop_access_scope (fn);
18338 pop_tinst_level ();
18339 spec = build_noexcept_spec (noex, tf_warning_or_error);
18340 if (spec == error_mark_node)
18341 spec = noexcept_false_spec;
18344 spec = noexcept_false_spec;
18348 /* This is an implicitly declared function, so NOEX is a list of
18349 other functions to evaluate and merge. */
18351 spec = noexcept_true_spec;
18352 for (elt = noex; elt; elt = OVL_NEXT (elt))
18354 tree fn = OVL_CURRENT (elt);
18356 maybe_instantiate_noexcept (fn);
18357 subspec = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (fn));
18358 spec = merge_exception_specifiers (spec, subspec, NULL_TREE);
18362 TREE_TYPE (fn) = build_exception_variant (fntype, spec);
18364 FOR_EACH_CLONE (clone, fn)
18366 if (TREE_TYPE (clone) == fntype)
18367 TREE_TYPE (clone) = TREE_TYPE (fn);
18369 TREE_TYPE (clone) = build_exception_variant (TREE_TYPE (clone), spec);
18373 /* Produce the definition of D, a _DECL generated from a template. If
18374 DEFER_OK is nonzero, then we don't have to actually do the
18375 instantiation now; we just have to do it sometime. Normally it is
18376 an error if this is an explicit instantiation but D is undefined.
18377 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
18378 explicitly instantiated class template. */
18381 instantiate_decl (tree d, int defer_ok,
18382 bool expl_inst_class_mem_p)
18384 tree tmpl = DECL_TI_TEMPLATE (d);
18391 bool pattern_defined;
18393 location_t saved_loc = input_location;
18396 /* This function should only be used to instantiate templates for
18397 functions and static member variables. */
18398 gcc_assert (TREE_CODE (d) == FUNCTION_DECL
18399 || TREE_CODE (d) == VAR_DECL);
18401 /* Variables are never deferred; if instantiation is required, they
18402 are instantiated right away. That allows for better code in the
18403 case that an expression refers to the value of the variable --
18404 if the variable has a constant value the referring expression can
18405 take advantage of that fact. */
18406 if (TREE_CODE (d) == VAR_DECL
18407 || DECL_DECLARED_CONSTEXPR_P (d))
18410 /* Don't instantiate cloned functions. Instead, instantiate the
18411 functions they cloned. */
18412 if (TREE_CODE (d) == FUNCTION_DECL && DECL_CLONED_FUNCTION_P (d))
18413 d = DECL_CLONED_FUNCTION (d);
18415 if (DECL_TEMPLATE_INSTANTIATED (d)
18416 || (TREE_CODE (d) == FUNCTION_DECL
18417 && DECL_DEFAULTED_FN (d) && DECL_INITIAL (d))
18418 || DECL_TEMPLATE_SPECIALIZATION (d))
18419 /* D has already been instantiated or explicitly specialized, so
18420 there's nothing for us to do here.
18422 It might seem reasonable to check whether or not D is an explicit
18423 instantiation, and, if so, stop here. But when an explicit
18424 instantiation is deferred until the end of the compilation,
18425 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
18426 the instantiation. */
18429 /* Check to see whether we know that this template will be
18430 instantiated in some other file, as with "extern template"
18432 external_p = (DECL_INTERFACE_KNOWN (d) && DECL_REALLY_EXTERN (d));
18434 /* In general, we do not instantiate such templates. */
18435 if (external_p && !always_instantiate_p (d))
18438 gen_tmpl = most_general_template (tmpl);
18439 gen_args = DECL_TI_ARGS (d);
18441 if (tmpl != gen_tmpl)
18442 /* We should already have the extra args. */
18443 gcc_assert (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (gen_tmpl))
18444 == TMPL_ARGS_DEPTH (gen_args));
18445 /* And what's in the hash table should match D. */
18446 gcc_assert ((spec = retrieve_specialization (gen_tmpl, gen_args, 0)) == d
18447 || spec == NULL_TREE);
18449 /* This needs to happen before any tsubsting. */
18450 if (! push_tinst_level (d))
18453 timevar_push (TV_TEMPLATE_INST);
18455 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
18456 for the instantiation. */
18457 td = template_for_substitution (d);
18458 code_pattern = DECL_TEMPLATE_RESULT (td);
18460 /* We should never be trying to instantiate a member of a class
18461 template or partial specialization. */
18462 gcc_assert (d != code_pattern);
18464 if ((DECL_NAMESPACE_SCOPE_P (d) && !DECL_INITIALIZED_IN_CLASS_P (d))
18465 || DECL_TEMPLATE_SPECIALIZATION (td))
18466 /* In the case of a friend template whose definition is provided
18467 outside the class, we may have too many arguments. Drop the
18468 ones we don't need. The same is true for specializations. */
18469 args = get_innermost_template_args
18470 (gen_args, TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (td)));
18474 if (TREE_CODE (d) == FUNCTION_DECL)
18475 pattern_defined = (DECL_SAVED_TREE (code_pattern) != NULL_TREE
18476 || DECL_DEFAULTED_OUTSIDE_CLASS_P (code_pattern));
18478 pattern_defined = ! DECL_IN_AGGR_P (code_pattern);
18480 /* We may be in the middle of deferred access check. Disable it now. */
18481 push_deferring_access_checks (dk_no_deferred);
18483 /* Unless an explicit instantiation directive has already determined
18484 the linkage of D, remember that a definition is available for
18486 if (pattern_defined
18487 && !DECL_INTERFACE_KNOWN (d)
18488 && !DECL_NOT_REALLY_EXTERN (d))
18489 mark_definable (d);
18491 DECL_SOURCE_LOCATION (td) = DECL_SOURCE_LOCATION (code_pattern);
18492 DECL_SOURCE_LOCATION (d) = DECL_SOURCE_LOCATION (code_pattern);
18493 input_location = DECL_SOURCE_LOCATION (d);
18495 /* If D is a member of an explicitly instantiated class template,
18496 and no definition is available, treat it like an implicit
18498 if (!pattern_defined && expl_inst_class_mem_p
18499 && DECL_EXPLICIT_INSTANTIATION (d))
18501 /* Leave linkage flags alone on instantiations with anonymous
18503 if (TREE_PUBLIC (d))
18505 DECL_NOT_REALLY_EXTERN (d) = 0;
18506 DECL_INTERFACE_KNOWN (d) = 0;
18508 SET_DECL_IMPLICIT_INSTANTIATION (d);
18511 if (TREE_CODE (d) == FUNCTION_DECL)
18512 maybe_instantiate_noexcept (d);
18514 /* Recheck the substitutions to obtain any warning messages
18515 about ignoring cv qualifiers. Don't do this for artificial decls,
18516 as it breaks the context-sensitive substitution for lambda op(). */
18517 if (!defer_ok && !DECL_ARTIFICIAL (d))
18519 tree gen = DECL_TEMPLATE_RESULT (gen_tmpl);
18520 tree type = TREE_TYPE (gen);
18522 /* Make sure that we can see identifiers, and compute access
18523 correctly. D is already the target FUNCTION_DECL with the
18525 push_access_scope (d);
18527 if (TREE_CODE (gen) == FUNCTION_DECL)
18529 tsubst (DECL_ARGUMENTS (gen), gen_args, tf_warning_or_error, d);
18530 tsubst_exception_specification (type, gen_args, tf_warning_or_error,
18531 d, /*defer_ok*/true);
18532 /* Don't simply tsubst the function type, as that will give
18533 duplicate warnings about poor parameter qualifications.
18534 The function arguments are the same as the decl_arguments
18535 without the top level cv qualifiers. */
18536 type = TREE_TYPE (type);
18538 tsubst (type, gen_args, tf_warning_or_error, d);
18540 pop_access_scope (d);
18543 /* Defer all other templates, unless we have been explicitly
18544 forbidden from doing so. */
18545 if (/* If there is no definition, we cannot instantiate the
18548 /* If it's OK to postpone instantiation, do so. */
18550 /* If this is a static data member that will be defined
18551 elsewhere, we don't want to instantiate the entire data
18552 member, but we do want to instantiate the initializer so that
18553 we can substitute that elsewhere. */
18554 || (external_p && TREE_CODE (d) == VAR_DECL))
18556 /* The definition of the static data member is now required so
18557 we must substitute the initializer. */
18558 if (TREE_CODE (d) == VAR_DECL
18559 && !DECL_INITIAL (d)
18560 && DECL_INITIAL (code_pattern))
18564 bool const_init = false;
18566 ns = decl_namespace_context (d);
18567 push_nested_namespace (ns);
18568 push_nested_class (DECL_CONTEXT (d));
18569 init = tsubst_expr (DECL_INITIAL (code_pattern),
18571 tf_warning_or_error, NULL_TREE,
18572 /*integral_constant_expression_p=*/false);
18573 /* Make sure the initializer is still constant, in case of
18574 circular dependency (template/instantiate6.C). */
18576 = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (code_pattern);
18577 cp_finish_decl (d, init, /*init_const_expr_p=*/const_init,
18578 /*asmspec_tree=*/NULL_TREE,
18579 LOOKUP_ONLYCONVERTING);
18580 pop_nested_class ();
18581 pop_nested_namespace (ns);
18584 /* We restore the source position here because it's used by
18585 add_pending_template. */
18586 input_location = saved_loc;
18588 if (at_eof && !pattern_defined
18589 && DECL_EXPLICIT_INSTANTIATION (d)
18590 && DECL_NOT_REALLY_EXTERN (d))
18593 The definition of a non-exported function template, a
18594 non-exported member function template, or a non-exported
18595 member function or static data member of a class template
18596 shall be present in every translation unit in which it is
18597 explicitly instantiated. */
18598 permerror (input_location, "explicit instantiation of %qD "
18599 "but no definition available", d);
18601 /* If we're in unevaluated context, we just wanted to get the
18602 constant value; this isn't an odr use, so don't queue
18603 a full instantiation. */
18604 if (cp_unevaluated_operand != 0)
18606 /* ??? Historically, we have instantiated inline functions, even
18607 when marked as "extern template". */
18608 if (!(external_p && TREE_CODE (d) == VAR_DECL))
18609 add_pending_template (d);
18612 /* Tell the repository that D is available in this translation unit
18613 -- and see if it is supposed to be instantiated here. */
18614 if (TREE_PUBLIC (d) && !DECL_REALLY_EXTERN (d) && !repo_emit_p (d))
18616 /* In a PCH file, despite the fact that the repository hasn't
18617 requested instantiation in the PCH it is still possible that
18618 an instantiation will be required in a file that includes the
18621 add_pending_template (d);
18622 /* Instantiate inline functions so that the inliner can do its
18623 job, even though we'll not be emitting a copy of this
18625 if (!(TREE_CODE (d) == FUNCTION_DECL && possibly_inlined_p (d)))
18629 need_push = !cfun || !global_bindings_p ();
18631 push_to_top_level ();
18633 /* Mark D as instantiated so that recursive calls to
18634 instantiate_decl do not try to instantiate it again. */
18635 DECL_TEMPLATE_INSTANTIATED (d) = 1;
18637 /* Regenerate the declaration in case the template has been modified
18638 by a subsequent redeclaration. */
18639 regenerate_decl_from_template (d, td);
18641 /* We already set the file and line above. Reset them now in case
18642 they changed as a result of calling regenerate_decl_from_template. */
18643 input_location = DECL_SOURCE_LOCATION (d);
18645 if (TREE_CODE (d) == VAR_DECL)
18648 bool const_init = false;
18650 /* Clear out DECL_RTL; whatever was there before may not be right
18651 since we've reset the type of the declaration. */
18652 SET_DECL_RTL (d, NULL);
18653 DECL_IN_AGGR_P (d) = 0;
18655 /* The initializer is placed in DECL_INITIAL by
18656 regenerate_decl_from_template so we don't need to
18657 push/pop_access_scope again here. Pull it out so that
18658 cp_finish_decl can process it. */
18659 init = DECL_INITIAL (d);
18660 DECL_INITIAL (d) = NULL_TREE;
18661 DECL_INITIALIZED_P (d) = 0;
18663 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
18664 initializer. That function will defer actual emission until
18665 we have a chance to determine linkage. */
18666 DECL_EXTERNAL (d) = 0;
18668 /* Enter the scope of D so that access-checking works correctly. */
18669 push_nested_class (DECL_CONTEXT (d));
18670 const_init = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (code_pattern);
18671 cp_finish_decl (d, init, const_init, NULL_TREE, 0);
18672 pop_nested_class ();
18674 else if (TREE_CODE (d) == FUNCTION_DECL && DECL_DEFAULTED_FN (code_pattern))
18675 synthesize_method (d);
18676 else if (TREE_CODE (d) == FUNCTION_DECL)
18678 htab_t saved_local_specializations;
18683 /* Save away the current list, in case we are instantiating one
18684 template from within the body of another. */
18685 saved_local_specializations = local_specializations;
18687 /* Set up the list of local specializations. */
18688 local_specializations = htab_create (37,
18689 hash_local_specialization,
18690 eq_local_specializations,
18693 /* Set up context. */
18694 start_preparsed_function (d, NULL_TREE, SF_PRE_PARSED);
18696 /* Create substitution entries for the parameters. */
18697 subst_decl = DECL_TEMPLATE_RESULT (template_for_substitution (d));
18698 tmpl_parm = DECL_ARGUMENTS (subst_decl);
18699 spec_parm = DECL_ARGUMENTS (d);
18700 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (d))
18702 register_local_specialization (spec_parm, tmpl_parm);
18703 spec_parm = skip_artificial_parms_for (d, spec_parm);
18704 tmpl_parm = skip_artificial_parms_for (subst_decl, tmpl_parm);
18706 for (; tmpl_parm; tmpl_parm = DECL_CHAIN (tmpl_parm))
18708 if (!FUNCTION_PARAMETER_PACK_P (tmpl_parm))
18710 register_local_specialization (spec_parm, tmpl_parm);
18711 spec_parm = DECL_CHAIN (spec_parm);
18715 /* Register the (value) argument pack as a specialization of
18716 TMPL_PARM, then move on. */
18717 tree argpack = extract_fnparm_pack (tmpl_parm, &spec_parm);
18718 register_local_specialization (argpack, tmpl_parm);
18721 gcc_assert (!spec_parm);
18723 /* Substitute into the body of the function. */
18724 tsubst_expr (DECL_SAVED_TREE (code_pattern), args,
18725 tf_warning_or_error, tmpl,
18726 /*integral_constant_expression_p=*/false);
18728 /* Set the current input_location to the end of the function
18729 so that finish_function knows where we are. */
18730 input_location = DECL_STRUCT_FUNCTION (code_pattern)->function_end_locus;
18732 /* We don't need the local specializations any more. */
18733 htab_delete (local_specializations);
18734 local_specializations = saved_local_specializations;
18736 /* Finish the function. */
18737 d = finish_function (0);
18738 expand_or_defer_fn (d);
18741 /* We're not deferring instantiation any more. */
18742 TI_PENDING_TEMPLATE_FLAG (DECL_TEMPLATE_INFO (d)) = 0;
18745 pop_from_top_level ();
18748 input_location = saved_loc;
18749 pop_deferring_access_checks ();
18750 pop_tinst_level ();
18752 timevar_pop (TV_TEMPLATE_INST);
18757 /* Run through the list of templates that we wish we could
18758 instantiate, and instantiate any we can. RETRIES is the
18759 number of times we retry pending template instantiation. */
18762 instantiate_pending_templates (int retries)
18765 location_t saved_loc = input_location;
18767 /* Instantiating templates may trigger vtable generation. This in turn
18768 may require further template instantiations. We place a limit here
18769 to avoid infinite loop. */
18770 if (pending_templates && retries >= max_tinst_depth)
18772 tree decl = pending_templates->tinst->decl;
18774 error ("template instantiation depth exceeds maximum of %d"
18775 " instantiating %q+D, possibly from virtual table generation"
18776 " (use -ftemplate-depth= to increase the maximum)",
18777 max_tinst_depth, decl);
18778 if (TREE_CODE (decl) == FUNCTION_DECL)
18779 /* Pretend that we defined it. */
18780 DECL_INITIAL (decl) = error_mark_node;
18786 struct pending_template **t = &pending_templates;
18787 struct pending_template *last = NULL;
18791 tree instantiation = reopen_tinst_level ((*t)->tinst);
18792 bool complete = false;
18794 if (TYPE_P (instantiation))
18798 if (!COMPLETE_TYPE_P (instantiation))
18800 instantiate_class_template (instantiation);
18801 if (CLASSTYPE_TEMPLATE_INSTANTIATION (instantiation))
18802 for (fn = TYPE_METHODS (instantiation);
18804 fn = TREE_CHAIN (fn))
18805 if (! DECL_ARTIFICIAL (fn))
18806 instantiate_decl (fn,
18808 /*expl_inst_class_mem_p=*/false);
18809 if (COMPLETE_TYPE_P (instantiation))
18813 complete = COMPLETE_TYPE_P (instantiation);
18817 if (!DECL_TEMPLATE_SPECIALIZATION (instantiation)
18818 && !DECL_TEMPLATE_INSTANTIATED (instantiation))
18821 = instantiate_decl (instantiation,
18823 /*expl_inst_class_mem_p=*/false);
18824 if (DECL_TEMPLATE_INSTANTIATED (instantiation))
18828 complete = (DECL_TEMPLATE_SPECIALIZATION (instantiation)
18829 || DECL_TEMPLATE_INSTANTIATED (instantiation));
18833 /* If INSTANTIATION has been instantiated, then we don't
18834 need to consider it again in the future. */
18842 current_tinst_level = NULL;
18844 last_pending_template = last;
18846 while (reconsider);
18848 input_location = saved_loc;
18851 /* Substitute ARGVEC into T, which is a list of initializers for
18852 either base class or a non-static data member. The TREE_PURPOSEs
18853 are DECLs, and the TREE_VALUEs are the initializer values. Used by
18854 instantiate_decl. */
18857 tsubst_initializer_list (tree t, tree argvec)
18859 tree inits = NULL_TREE;
18861 for (; t; t = TREE_CHAIN (t))
18865 tree expanded_bases = NULL_TREE;
18866 tree expanded_arguments = NULL_TREE;
18869 if (TREE_CODE (TREE_PURPOSE (t)) == TYPE_PACK_EXPANSION)
18874 /* Expand the base class expansion type into separate base
18876 expanded_bases = tsubst_pack_expansion (TREE_PURPOSE (t), argvec,
18877 tf_warning_or_error,
18879 if (expanded_bases == error_mark_node)
18882 /* We'll be building separate TREE_LISTs of arguments for
18884 len = TREE_VEC_LENGTH (expanded_bases);
18885 expanded_arguments = make_tree_vec (len);
18886 for (i = 0; i < len; i++)
18887 TREE_VEC_ELT (expanded_arguments, i) = NULL_TREE;
18889 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
18890 expand each argument in the TREE_VALUE of t. */
18891 expr = make_node (EXPR_PACK_EXPANSION);
18892 PACK_EXPANSION_PARAMETER_PACKS (expr) =
18893 PACK_EXPANSION_PARAMETER_PACKS (TREE_PURPOSE (t));
18895 if (TREE_VALUE (t) == void_type_node)
18896 /* VOID_TYPE_NODE is used to indicate
18897 value-initialization. */
18899 for (i = 0; i < len; i++)
18900 TREE_VEC_ELT (expanded_arguments, i) = void_type_node;
18904 /* Substitute parameter packs into each argument in the
18906 in_base_initializer = 1;
18907 for (arg = TREE_VALUE (t); arg; arg = TREE_CHAIN (arg))
18909 tree expanded_exprs;
18911 /* Expand the argument. */
18912 SET_PACK_EXPANSION_PATTERN (expr, TREE_VALUE (arg));
18914 = tsubst_pack_expansion (expr, argvec,
18915 tf_warning_or_error,
18917 if (expanded_exprs == error_mark_node)
18920 /* Prepend each of the expanded expressions to the
18921 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
18922 for (i = 0; i < len; i++)
18924 TREE_VEC_ELT (expanded_arguments, i) =
18925 tree_cons (NULL_TREE,
18926 TREE_VEC_ELT (expanded_exprs, i),
18927 TREE_VEC_ELT (expanded_arguments, i));
18930 in_base_initializer = 0;
18932 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
18933 since we built them backwards. */
18934 for (i = 0; i < len; i++)
18936 TREE_VEC_ELT (expanded_arguments, i) =
18937 nreverse (TREE_VEC_ELT (expanded_arguments, i));
18942 for (i = 0; i < len; ++i)
18944 if (expanded_bases)
18946 decl = TREE_VEC_ELT (expanded_bases, i);
18947 decl = expand_member_init (decl);
18948 init = TREE_VEC_ELT (expanded_arguments, i);
18952 decl = tsubst_copy (TREE_PURPOSE (t), argvec,
18953 tf_warning_or_error, NULL_TREE);
18955 decl = expand_member_init (decl);
18956 if (decl && !DECL_P (decl))
18957 in_base_initializer = 1;
18959 init = TREE_VALUE (t);
18960 if (init != void_type_node)
18961 init = tsubst_expr (init, argvec,
18962 tf_warning_or_error, NULL_TREE,
18963 /*integral_constant_expression_p=*/false);
18964 in_base_initializer = 0;
18969 init = build_tree_list (decl, init);
18970 TREE_CHAIN (init) = inits;
18978 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
18981 set_current_access_from_decl (tree decl)
18983 if (TREE_PRIVATE (decl))
18984 current_access_specifier = access_private_node;
18985 else if (TREE_PROTECTED (decl))
18986 current_access_specifier = access_protected_node;
18988 current_access_specifier = access_public_node;
18991 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
18992 is the instantiation (which should have been created with
18993 start_enum) and ARGS are the template arguments to use. */
18996 tsubst_enum (tree tag, tree newtag, tree args)
19000 if (SCOPED_ENUM_P (newtag))
19001 begin_scope (sk_scoped_enum, newtag);
19003 for (e = TYPE_VALUES (tag); e; e = TREE_CHAIN (e))
19008 decl = TREE_VALUE (e);
19009 /* Note that in a template enum, the TREE_VALUE is the
19010 CONST_DECL, not the corresponding INTEGER_CST. */
19011 value = tsubst_expr (DECL_INITIAL (decl),
19012 args, tf_warning_or_error, NULL_TREE,
19013 /*integral_constant_expression_p=*/true);
19015 /* Give this enumeration constant the correct access. */
19016 set_current_access_from_decl (decl);
19018 /* Actually build the enumerator itself. */
19020 (DECL_NAME (decl), value, newtag, DECL_SOURCE_LOCATION (decl));
19023 if (SCOPED_ENUM_P (newtag))
19026 finish_enum_value_list (newtag);
19027 finish_enum (newtag);
19029 DECL_SOURCE_LOCATION (TYPE_NAME (newtag))
19030 = DECL_SOURCE_LOCATION (TYPE_NAME (tag));
19033 /* DECL is a FUNCTION_DECL that is a template specialization. Return
19034 its type -- but without substituting the innermost set of template
19035 arguments. So, innermost set of template parameters will appear in
19039 get_mostly_instantiated_function_type (tree decl)
19047 tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
19048 targs = DECL_TI_ARGS (decl);
19049 tparms = DECL_TEMPLATE_PARMS (tmpl);
19050 parm_depth = TMPL_PARMS_DEPTH (tparms);
19052 /* There should be as many levels of arguments as there are levels
19054 gcc_assert (parm_depth == TMPL_ARGS_DEPTH (targs));
19056 fn_type = TREE_TYPE (tmpl);
19058 if (parm_depth == 1)
19059 /* No substitution is necessary. */
19066 /* Replace the innermost level of the TARGS with NULL_TREEs to
19067 let tsubst know not to substitute for those parameters. */
19068 partial_args = make_tree_vec (TREE_VEC_LENGTH (targs));
19069 for (i = 1; i < TMPL_ARGS_DEPTH (targs); ++i)
19070 SET_TMPL_ARGS_LEVEL (partial_args, i,
19071 TMPL_ARGS_LEVEL (targs, i));
19072 SET_TMPL_ARGS_LEVEL (partial_args,
19073 TMPL_ARGS_DEPTH (targs),
19074 make_tree_vec (DECL_NTPARMS (tmpl)));
19076 /* Make sure that we can see identifiers, and compute access
19078 push_access_scope (decl);
19080 ++processing_template_decl;
19081 /* Now, do the (partial) substitution to figure out the
19082 appropriate function type. */
19083 fn_type = tsubst (fn_type, partial_args, tf_error, NULL_TREE);
19084 --processing_template_decl;
19086 /* Substitute into the template parameters to obtain the real
19087 innermost set of parameters. This step is important if the
19088 innermost set of template parameters contains value
19089 parameters whose types depend on outer template parameters. */
19090 TREE_VEC_LENGTH (partial_args)--;
19091 tparms = tsubst_template_parms (tparms, partial_args, tf_error);
19093 pop_access_scope (decl);
19099 /* Return truthvalue if we're processing a template different from
19100 the last one involved in diagnostics. */
19102 problematic_instantiation_changed (void)
19104 return current_tinst_level != last_error_tinst_level;
19107 /* Remember current template involved in diagnostics. */
19109 record_last_problematic_instantiation (void)
19111 last_error_tinst_level = current_tinst_level;
19114 struct tinst_level *
19115 current_instantiation (void)
19117 return current_tinst_level;
19120 /* [temp.param] Check that template non-type parm TYPE is of an allowable
19121 type. Return zero for ok, nonzero for disallowed. Issue error and
19122 warning messages under control of COMPLAIN. */
19125 invalid_nontype_parm_type_p (tree type, tsubst_flags_t complain)
19127 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
19129 else if (POINTER_TYPE_P (type))
19131 else if (TYPE_PTR_TO_MEMBER_P (type))
19133 else if (TREE_CODE (type) == TEMPLATE_TYPE_PARM)
19135 else if (TREE_CODE (type) == TYPENAME_TYPE)
19137 else if (TREE_CODE (type) == DECLTYPE_TYPE)
19139 else if (TREE_CODE (type) == NULLPTR_TYPE)
19142 if (complain & tf_error)
19144 if (type == error_mark_node)
19145 inform (input_location, "invalid template non-type parameter");
19147 error ("%q#T is not a valid type for a template non-type parameter",
19153 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
19154 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
19157 dependent_type_p_r (tree type)
19163 A type is dependent if it is:
19165 -- a template parameter. Template template parameters are types
19166 for us (since TYPE_P holds true for them) so we handle
19168 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
19169 || TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM)
19171 /* -- a qualified-id with a nested-name-specifier which contains a
19172 class-name that names a dependent type or whose unqualified-id
19173 names a dependent type. */
19174 if (TREE_CODE (type) == TYPENAME_TYPE)
19176 /* -- a cv-qualified type where the cv-unqualified type is
19178 type = TYPE_MAIN_VARIANT (type);
19179 /* -- a compound type constructed from any dependent type. */
19180 if (TYPE_PTR_TO_MEMBER_P (type))
19181 return (dependent_type_p (TYPE_PTRMEM_CLASS_TYPE (type))
19182 || dependent_type_p (TYPE_PTRMEM_POINTED_TO_TYPE
19184 else if (TREE_CODE (type) == POINTER_TYPE
19185 || TREE_CODE (type) == REFERENCE_TYPE)
19186 return dependent_type_p (TREE_TYPE (type));
19187 else if (TREE_CODE (type) == FUNCTION_TYPE
19188 || TREE_CODE (type) == METHOD_TYPE)
19192 if (dependent_type_p (TREE_TYPE (type)))
19194 for (arg_type = TYPE_ARG_TYPES (type);
19196 arg_type = TREE_CHAIN (arg_type))
19197 if (dependent_type_p (TREE_VALUE (arg_type)))
19201 /* -- an array type constructed from any dependent type or whose
19202 size is specified by a constant expression that is
19205 We checked for type- and value-dependence of the bounds in
19206 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
19207 if (TREE_CODE (type) == ARRAY_TYPE)
19209 if (TYPE_DOMAIN (type)
19210 && dependent_type_p (TYPE_DOMAIN (type)))
19212 return dependent_type_p (TREE_TYPE (type));
19215 /* -- a template-id in which either the template name is a template
19217 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
19219 /* ... or any of the template arguments is a dependent type or
19220 an expression that is type-dependent or value-dependent. */
19221 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INFO (type)
19222 && (any_dependent_template_arguments_p
19223 (INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type)))))
19226 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
19227 dependent; if the argument of the `typeof' expression is not
19228 type-dependent, then it should already been have resolved. */
19229 if (TREE_CODE (type) == TYPEOF_TYPE
19230 || TREE_CODE (type) == DECLTYPE_TYPE
19231 || TREE_CODE (type) == UNDERLYING_TYPE)
19234 /* A template argument pack is dependent if any of its packed
19236 if (TREE_CODE (type) == TYPE_ARGUMENT_PACK)
19238 tree args = ARGUMENT_PACK_ARGS (type);
19239 int i, len = TREE_VEC_LENGTH (args);
19240 for (i = 0; i < len; ++i)
19241 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
19245 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
19246 be template parameters. */
19247 if (TREE_CODE (type) == TYPE_PACK_EXPANSION)
19250 /* The standard does not specifically mention types that are local
19251 to template functions or local classes, but they should be
19252 considered dependent too. For example:
19254 template <int I> void f() {
19259 The size of `E' cannot be known until the value of `I' has been
19260 determined. Therefore, `E' must be considered dependent. */
19261 scope = TYPE_CONTEXT (type);
19262 if (scope && TYPE_P (scope))
19263 return dependent_type_p (scope);
19264 /* Don't use type_dependent_expression_p here, as it can lead
19265 to infinite recursion trying to determine whether a lambda
19266 nested in a lambda is dependent (c++/47687). */
19267 else if (scope && TREE_CODE (scope) == FUNCTION_DECL
19268 && DECL_LANG_SPECIFIC (scope)
19269 && DECL_TEMPLATE_INFO (scope)
19270 && (any_dependent_template_arguments_p
19271 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (scope)))))
19274 /* Other types are non-dependent. */
19278 /* Returns TRUE if TYPE is dependent, in the sense of
19279 [temp.dep.type]. Note that a NULL type is considered dependent. */
19282 dependent_type_p (tree type)
19284 /* If there are no template parameters in scope, then there can't be
19285 any dependent types. */
19286 if (!processing_template_decl)
19288 /* If we are not processing a template, then nobody should be
19289 providing us with a dependent type. */
19291 gcc_assert (TREE_CODE (type) != TEMPLATE_TYPE_PARM || is_auto (type));
19295 /* If the type is NULL, we have not computed a type for the entity
19296 in question; in that case, the type is dependent. */
19300 /* Erroneous types can be considered non-dependent. */
19301 if (type == error_mark_node)
19304 /* If we have not already computed the appropriate value for TYPE,
19306 if (!TYPE_DEPENDENT_P_VALID (type))
19308 TYPE_DEPENDENT_P (type) = dependent_type_p_r (type);
19309 TYPE_DEPENDENT_P_VALID (type) = 1;
19312 return TYPE_DEPENDENT_P (type);
19315 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
19316 lookup. In other words, a dependent type that is not the current
19320 dependent_scope_p (tree scope)
19322 return (scope && TYPE_P (scope) && dependent_type_p (scope)
19323 && !currently_open_class (scope));
19326 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
19327 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
19330 /* Note that this predicate is not appropriate for general expressions;
19331 only constant expressions (that satisfy potential_constant_expression)
19332 can be tested for value dependence.
19334 We should really also have a predicate for "instantiation-dependent".
19336 fold_non_dependent_expr: fold if constant and not type-dependent and not value-dependent.
19337 (what about instantiation-dependent constant-expressions?)
19338 is_late_template_attribute: defer if instantiation-dependent.
19339 compute_array_index_type: proceed if constant and not t- or v-dependent
19340 if instantiation-dependent, need to remember full expression
19341 uses_template_parms: FIXME - need to audit callers
19342 tsubst_decl [function_decl]: Why is this using value_dependent_expression_p?
19343 dependent_type_p [array_type]: dependent if index type is dependent
19345 static_assert - instantiation-dependent */
19348 value_dependent_expression_p (tree expression)
19350 if (!processing_template_decl)
19353 /* A name declared with a dependent type. */
19354 if (DECL_P (expression) && type_dependent_expression_p (expression))
19357 switch (TREE_CODE (expression))
19359 case IDENTIFIER_NODE:
19360 /* A name that has not been looked up -- must be dependent. */
19363 case TEMPLATE_PARM_INDEX:
19364 /* A non-type template parm. */
19368 /* A non-type template parm. */
19369 if (DECL_TEMPLATE_PARM_P (expression))
19371 return value_dependent_expression_p (DECL_INITIAL (expression));
19374 /* A constant with literal type and is initialized
19375 with an expression that is value-dependent. */
19376 if (DECL_INITIAL (expression)
19377 && decl_constant_var_p (expression)
19378 && value_dependent_expression_p (DECL_INITIAL (expression)))
19382 case DYNAMIC_CAST_EXPR:
19383 case STATIC_CAST_EXPR:
19384 case CONST_CAST_EXPR:
19385 case REINTERPRET_CAST_EXPR:
19387 /* These expressions are value-dependent if the type to which
19388 the cast occurs is dependent or the expression being casted
19389 is value-dependent. */
19391 tree type = TREE_TYPE (expression);
19393 if (dependent_type_p (type))
19396 /* A functional cast has a list of operands. */
19397 expression = TREE_OPERAND (expression, 0);
19400 /* If there are no operands, it must be an expression such
19401 as "int()". This should not happen for aggregate types
19402 because it would form non-constant expressions. */
19403 gcc_assert (cxx_dialect >= cxx0x
19404 || INTEGRAL_OR_ENUMERATION_TYPE_P (type));
19409 if (TREE_CODE (expression) == TREE_LIST)
19410 return any_value_dependent_elements_p (expression);
19412 return value_dependent_expression_p (expression);
19418 /* A `sizeof' expression is value-dependent if the operand is
19419 type-dependent or is a pack expansion. */
19420 expression = TREE_OPERAND (expression, 0);
19421 if (PACK_EXPANSION_P (expression))
19423 else if (TYPE_P (expression))
19424 return dependent_type_p (expression);
19425 return type_dependent_expression_p (expression);
19427 case AT_ENCODE_EXPR:
19428 /* An 'encode' expression is value-dependent if the operand is
19430 expression = TREE_OPERAND (expression, 0);
19431 return dependent_type_p (expression);
19433 case NOEXCEPT_EXPR:
19434 expression = TREE_OPERAND (expression, 0);
19435 return type_dependent_expression_p (expression);
19439 tree name = TREE_OPERAND (expression, 1);
19440 return value_dependent_expression_p (name);
19443 case COMPONENT_REF:
19444 return (value_dependent_expression_p (TREE_OPERAND (expression, 0))
19445 || value_dependent_expression_p (TREE_OPERAND (expression, 1)));
19447 case NONTYPE_ARGUMENT_PACK:
19448 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
19449 is value-dependent. */
19451 tree values = ARGUMENT_PACK_ARGS (expression);
19452 int i, len = TREE_VEC_LENGTH (values);
19454 for (i = 0; i < len; ++i)
19455 if (value_dependent_expression_p (TREE_VEC_ELT (values, i)))
19463 tree type2 = TRAIT_EXPR_TYPE2 (expression);
19464 return (dependent_type_p (TRAIT_EXPR_TYPE1 (expression))
19465 || (type2 ? dependent_type_p (type2) : false));
19469 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
19470 || (value_dependent_expression_p (TREE_OPERAND (expression, 2))));
19473 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
19474 || (value_dependent_expression_p (TREE_OPERAND (expression, 1))));
19478 tree op = TREE_OPERAND (expression, 0);
19479 return (value_dependent_expression_p (op)
19480 || has_value_dependent_address (op));
19485 tree fn = get_callee_fndecl (expression);
19487 if (!fn && value_dependent_expression_p (CALL_EXPR_FN (expression)))
19489 nargs = call_expr_nargs (expression);
19490 for (i = 0; i < nargs; ++i)
19492 tree op = CALL_EXPR_ARG (expression, i);
19493 /* In a call to a constexpr member function, look through the
19494 implicit ADDR_EXPR on the object argument so that it doesn't
19495 cause the call to be considered value-dependent. We also
19496 look through it in potential_constant_expression. */
19497 if (i == 0 && fn && DECL_DECLARED_CONSTEXPR_P (fn)
19498 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
19499 && TREE_CODE (op) == ADDR_EXPR)
19500 op = TREE_OPERAND (op, 0);
19501 if (value_dependent_expression_p (op))
19507 case TEMPLATE_ID_EXPR:
19508 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
19510 return type_dependent_expression_p (expression);
19516 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), ix, val)
19517 if (value_dependent_expression_p (val))
19523 /* A constant expression is value-dependent if any subexpression is
19524 value-dependent. */
19525 switch (TREE_CODE_CLASS (TREE_CODE (expression)))
19527 case tcc_reference:
19529 case tcc_comparison:
19531 case tcc_expression:
19534 int i, len = cp_tree_operand_length (expression);
19536 for (i = 0; i < len; i++)
19538 tree t = TREE_OPERAND (expression, i);
19540 /* In some cases, some of the operands may be missing.l
19541 (For example, in the case of PREDECREMENT_EXPR, the
19542 amount to increment by may be missing.) That doesn't
19543 make the expression dependent. */
19544 if (t && value_dependent_expression_p (t))
19555 /* The expression is not value-dependent. */
19559 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
19560 [temp.dep.expr]. Note that an expression with no type is
19561 considered dependent. Other parts of the compiler arrange for an
19562 expression with type-dependent subexpressions to have no type, so
19563 this function doesn't have to be fully recursive. */
19566 type_dependent_expression_p (tree expression)
19568 if (!processing_template_decl)
19571 if (expression == error_mark_node)
19574 /* An unresolved name is always dependent. */
19575 if (TREE_CODE (expression) == IDENTIFIER_NODE
19576 || TREE_CODE (expression) == USING_DECL)
19579 /* Some expression forms are never type-dependent. */
19580 if (TREE_CODE (expression) == PSEUDO_DTOR_EXPR
19581 || TREE_CODE (expression) == SIZEOF_EXPR
19582 || TREE_CODE (expression) == ALIGNOF_EXPR
19583 || TREE_CODE (expression) == AT_ENCODE_EXPR
19584 || TREE_CODE (expression) == NOEXCEPT_EXPR
19585 || TREE_CODE (expression) == TRAIT_EXPR
19586 || TREE_CODE (expression) == TYPEID_EXPR
19587 || TREE_CODE (expression) == DELETE_EXPR
19588 || TREE_CODE (expression) == VEC_DELETE_EXPR
19589 || TREE_CODE (expression) == THROW_EXPR)
19592 /* The types of these expressions depends only on the type to which
19593 the cast occurs. */
19594 if (TREE_CODE (expression) == DYNAMIC_CAST_EXPR
19595 || TREE_CODE (expression) == STATIC_CAST_EXPR
19596 || TREE_CODE (expression) == CONST_CAST_EXPR
19597 || TREE_CODE (expression) == REINTERPRET_CAST_EXPR
19598 || TREE_CODE (expression) == IMPLICIT_CONV_EXPR
19599 || TREE_CODE (expression) == CAST_EXPR)
19600 return dependent_type_p (TREE_TYPE (expression));
19602 /* The types of these expressions depends only on the type created
19603 by the expression. */
19604 if (TREE_CODE (expression) == NEW_EXPR
19605 || TREE_CODE (expression) == VEC_NEW_EXPR)
19607 /* For NEW_EXPR tree nodes created inside a template, either
19608 the object type itself or a TREE_LIST may appear as the
19610 tree type = TREE_OPERAND (expression, 1);
19611 if (TREE_CODE (type) == TREE_LIST)
19612 /* This is an array type. We need to check array dimensions
19614 return dependent_type_p (TREE_VALUE (TREE_PURPOSE (type)))
19615 || value_dependent_expression_p
19616 (TREE_OPERAND (TREE_VALUE (type), 1));
19618 return dependent_type_p (type);
19621 if (TREE_CODE (expression) == SCOPE_REF)
19623 tree scope = TREE_OPERAND (expression, 0);
19624 tree name = TREE_OPERAND (expression, 1);
19626 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
19627 contains an identifier associated by name lookup with one or more
19628 declarations declared with a dependent type, or...a
19629 nested-name-specifier or qualified-id that names a member of an
19630 unknown specialization. */
19631 return (type_dependent_expression_p (name)
19632 || dependent_scope_p (scope));
19635 if (TREE_CODE (expression) == FUNCTION_DECL
19636 && DECL_LANG_SPECIFIC (expression)
19637 && DECL_TEMPLATE_INFO (expression)
19638 && (any_dependent_template_arguments_p
19639 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (expression)))))
19642 if (TREE_CODE (expression) == TEMPLATE_DECL
19643 && !DECL_TEMPLATE_TEMPLATE_PARM_P (expression))
19646 if (TREE_CODE (expression) == STMT_EXPR)
19647 expression = stmt_expr_value_expr (expression);
19649 if (BRACE_ENCLOSED_INITIALIZER_P (expression))
19654 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), i, elt)
19656 if (type_dependent_expression_p (elt))
19662 /* A static data member of the current instantiation with incomplete
19663 array type is type-dependent, as the definition and specializations
19664 can have different bounds. */
19665 if (TREE_CODE (expression) == VAR_DECL
19666 && DECL_CLASS_SCOPE_P (expression)
19667 && dependent_type_p (DECL_CONTEXT (expression))
19668 && VAR_HAD_UNKNOWN_BOUND (expression))
19671 if (TREE_TYPE (expression) == unknown_type_node)
19673 if (TREE_CODE (expression) == ADDR_EXPR)
19674 return type_dependent_expression_p (TREE_OPERAND (expression, 0));
19675 if (TREE_CODE (expression) == COMPONENT_REF
19676 || TREE_CODE (expression) == OFFSET_REF)
19678 if (type_dependent_expression_p (TREE_OPERAND (expression, 0)))
19680 expression = TREE_OPERAND (expression, 1);
19681 if (TREE_CODE (expression) == IDENTIFIER_NODE)
19684 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
19685 if (TREE_CODE (expression) == SCOPE_REF)
19688 if (BASELINK_P (expression))
19689 expression = BASELINK_FUNCTIONS (expression);
19691 if (TREE_CODE (expression) == TEMPLATE_ID_EXPR)
19693 if (any_dependent_template_arguments_p
19694 (TREE_OPERAND (expression, 1)))
19696 expression = TREE_OPERAND (expression, 0);
19698 gcc_assert (TREE_CODE (expression) == OVERLOAD
19699 || TREE_CODE (expression) == FUNCTION_DECL);
19703 if (type_dependent_expression_p (OVL_CURRENT (expression)))
19705 expression = OVL_NEXT (expression);
19710 gcc_assert (TREE_CODE (expression) != TYPE_DECL);
19712 return (dependent_type_p (TREE_TYPE (expression)));
19715 /* Like type_dependent_expression_p, but it also works while not processing
19716 a template definition, i.e. during substitution or mangling. */
19719 type_dependent_expression_p_push (tree expr)
19722 ++processing_template_decl;
19723 b = type_dependent_expression_p (expr);
19724 --processing_template_decl;
19728 /* Returns TRUE if ARGS contains a type-dependent expression. */
19731 any_type_dependent_arguments_p (const VEC(tree,gc) *args)
19736 FOR_EACH_VEC_ELT (tree, args, i, arg)
19738 if (type_dependent_expression_p (arg))
19744 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
19745 expressions) contains any type-dependent expressions. */
19748 any_type_dependent_elements_p (const_tree list)
19750 for (; list; list = TREE_CHAIN (list))
19751 if (value_dependent_expression_p (TREE_VALUE (list)))
19757 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
19758 expressions) contains any value-dependent expressions. */
19761 any_value_dependent_elements_p (const_tree list)
19763 for (; list; list = TREE_CHAIN (list))
19764 if (value_dependent_expression_p (TREE_VALUE (list)))
19770 /* Returns TRUE if the ARG (a template argument) is dependent. */
19773 dependent_template_arg_p (tree arg)
19775 if (!processing_template_decl)
19778 /* Assume a template argument that was wrongly written by the user
19779 is dependent. This is consistent with what
19780 any_dependent_template_arguments_p [that calls this function]
19782 if (!arg || arg == error_mark_node)
19785 if (TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
19786 arg = ARGUMENT_PACK_SELECT_ARG (arg);
19788 if (TREE_CODE (arg) == TEMPLATE_DECL
19789 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
19790 return dependent_template_p (arg);
19791 else if (ARGUMENT_PACK_P (arg))
19793 tree args = ARGUMENT_PACK_ARGS (arg);
19794 int i, len = TREE_VEC_LENGTH (args);
19795 for (i = 0; i < len; ++i)
19797 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
19803 else if (TYPE_P (arg))
19804 return dependent_type_p (arg);
19806 return (type_dependent_expression_p (arg)
19807 || value_dependent_expression_p (arg));
19810 /* Returns true if ARGS (a collection of template arguments) contains
19811 any types that require structural equality testing. */
19814 any_template_arguments_need_structural_equality_p (tree args)
19821 if (args == error_mark_node)
19824 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
19826 tree level = TMPL_ARGS_LEVEL (args, i + 1);
19827 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
19829 tree arg = TREE_VEC_ELT (level, j);
19830 tree packed_args = NULL_TREE;
19833 if (ARGUMENT_PACK_P (arg))
19835 /* Look inside the argument pack. */
19836 packed_args = ARGUMENT_PACK_ARGS (arg);
19837 len = TREE_VEC_LENGTH (packed_args);
19840 for (k = 0; k < len; ++k)
19843 arg = TREE_VEC_ELT (packed_args, k);
19845 if (error_operand_p (arg))
19847 else if (TREE_CODE (arg) == TEMPLATE_DECL
19848 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
19850 else if (TYPE_P (arg) && TYPE_STRUCTURAL_EQUALITY_P (arg))
19852 else if (!TYPE_P (arg) && TREE_TYPE (arg)
19853 && TYPE_STRUCTURAL_EQUALITY_P (TREE_TYPE (arg)))
19862 /* Returns true if ARGS (a collection of template arguments) contains
19863 any dependent arguments. */
19866 any_dependent_template_arguments_p (const_tree args)
19873 if (args == error_mark_node)
19876 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
19878 const_tree level = TMPL_ARGS_LEVEL (args, i + 1);
19879 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
19880 if (dependent_template_arg_p (TREE_VEC_ELT (level, j)))
19887 /* Returns TRUE if the template TMPL is dependent. */
19890 dependent_template_p (tree tmpl)
19892 if (TREE_CODE (tmpl) == OVERLOAD)
19896 if (dependent_template_p (OVL_CURRENT (tmpl)))
19898 tmpl = OVL_NEXT (tmpl);
19903 /* Template template parameters are dependent. */
19904 if (DECL_TEMPLATE_TEMPLATE_PARM_P (tmpl)
19905 || TREE_CODE (tmpl) == TEMPLATE_TEMPLATE_PARM)
19907 /* So are names that have not been looked up. */
19908 if (TREE_CODE (tmpl) == SCOPE_REF
19909 || TREE_CODE (tmpl) == IDENTIFIER_NODE)
19911 /* So are member templates of dependent classes. */
19912 if (TYPE_P (CP_DECL_CONTEXT (tmpl)))
19913 return dependent_type_p (DECL_CONTEXT (tmpl));
19917 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
19920 dependent_template_id_p (tree tmpl, tree args)
19922 return (dependent_template_p (tmpl)
19923 || any_dependent_template_arguments_p (args));
19926 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
19930 dependent_omp_for_p (tree declv, tree initv, tree condv, tree incrv)
19934 if (!processing_template_decl)
19937 for (i = 0; i < TREE_VEC_LENGTH (declv); i++)
19939 tree decl = TREE_VEC_ELT (declv, i);
19940 tree init = TREE_VEC_ELT (initv, i);
19941 tree cond = TREE_VEC_ELT (condv, i);
19942 tree incr = TREE_VEC_ELT (incrv, i);
19944 if (type_dependent_expression_p (decl))
19947 if (init && type_dependent_expression_p (init))
19950 if (type_dependent_expression_p (cond))
19953 if (COMPARISON_CLASS_P (cond)
19954 && (type_dependent_expression_p (TREE_OPERAND (cond, 0))
19955 || type_dependent_expression_p (TREE_OPERAND (cond, 1))))
19958 if (TREE_CODE (incr) == MODOP_EXPR)
19960 if (type_dependent_expression_p (TREE_OPERAND (incr, 0))
19961 || type_dependent_expression_p (TREE_OPERAND (incr, 2)))
19964 else if (type_dependent_expression_p (incr))
19966 else if (TREE_CODE (incr) == MODIFY_EXPR)
19968 if (type_dependent_expression_p (TREE_OPERAND (incr, 0)))
19970 else if (BINARY_CLASS_P (TREE_OPERAND (incr, 1)))
19972 tree t = TREE_OPERAND (incr, 1);
19973 if (type_dependent_expression_p (TREE_OPERAND (t, 0))
19974 || type_dependent_expression_p (TREE_OPERAND (t, 1)))
19983 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
19984 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
19985 no such TYPE can be found. Note that this function peers inside
19986 uninstantiated templates and therefore should be used only in
19987 extremely limited situations. ONLY_CURRENT_P restricts this
19988 peering to the currently open classes hierarchy (which is required
19989 when comparing types). */
19992 resolve_typename_type (tree type, bool only_current_p)
20001 gcc_assert (TREE_CODE (type) == TYPENAME_TYPE);
20003 scope = TYPE_CONTEXT (type);
20004 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
20005 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
20006 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
20007 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
20008 identifier of the TYPENAME_TYPE anymore.
20009 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
20010 TYPENAME_TYPE instead, we avoid messing up with a possible
20011 typedef variant case. */
20012 name = TYPE_IDENTIFIER (TYPE_MAIN_VARIANT (type));
20014 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
20015 it first before we can figure out what NAME refers to. */
20016 if (TREE_CODE (scope) == TYPENAME_TYPE)
20017 scope = resolve_typename_type (scope, only_current_p);
20018 /* If we don't know what SCOPE refers to, then we cannot resolve the
20020 if (TREE_CODE (scope) == TYPENAME_TYPE)
20022 /* If the SCOPE is a template type parameter, we have no way of
20023 resolving the name. */
20024 if (TREE_CODE (scope) == TEMPLATE_TYPE_PARM)
20026 /* If the SCOPE is not the current instantiation, there's no reason
20027 to look inside it. */
20028 if (only_current_p && !currently_open_class (scope))
20030 /* If this is a typedef, we don't want to look inside (c++/11987). */
20031 if (typedef_variant_p (type))
20033 /* If SCOPE isn't the template itself, it will not have a valid
20034 TYPE_FIELDS list. */
20035 if (same_type_p (scope, CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope)))
20036 /* scope is either the template itself or a compatible instantiation
20037 like X<T>, so look up the name in the original template. */
20038 scope = CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope);
20040 /* scope is a partial instantiation, so we can't do the lookup or we
20041 will lose the template arguments. */
20043 /* Enter the SCOPE so that name lookup will be resolved as if we
20044 were in the class definition. In particular, SCOPE will no
20045 longer be considered a dependent type. */
20046 pushed_scope = push_scope (scope);
20047 /* Look up the declaration. */
20048 decl = lookup_member (scope, name, /*protect=*/0, /*want_type=*/true,
20049 tf_warning_or_error);
20051 result = NULL_TREE;
20053 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
20054 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
20057 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == IDENTIFIER_NODE
20058 && TREE_CODE (decl) == TYPE_DECL)
20060 result = TREE_TYPE (decl);
20061 if (result == error_mark_node)
20062 result = NULL_TREE;
20064 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == TEMPLATE_ID_EXPR
20065 && DECL_CLASS_TEMPLATE_P (decl))
20069 /* Obtain the template and the arguments. */
20070 tmpl = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 0);
20071 args = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 1);
20072 /* Instantiate the template. */
20073 result = lookup_template_class (tmpl, args, NULL_TREE, NULL_TREE,
20074 /*entering_scope=*/0,
20075 tf_error | tf_user);
20076 if (result == error_mark_node)
20077 result = NULL_TREE;
20080 /* Leave the SCOPE. */
20082 pop_scope (pushed_scope);
20084 /* If we failed to resolve it, return the original typename. */
20088 /* If lookup found a typename type, resolve that too. */
20089 if (TREE_CODE (result) == TYPENAME_TYPE && !TYPENAME_IS_RESOLVING_P (result))
20091 /* Ill-formed programs can cause infinite recursion here, so we
20092 must catch that. */
20093 TYPENAME_IS_RESOLVING_P (type) = 1;
20094 result = resolve_typename_type (result, only_current_p);
20095 TYPENAME_IS_RESOLVING_P (type) = 0;
20098 /* Qualify the resulting type. */
20099 quals = cp_type_quals (type);
20101 result = cp_build_qualified_type (result, cp_type_quals (result) | quals);
20106 /* EXPR is an expression which is not type-dependent. Return a proxy
20107 for EXPR that can be used to compute the types of larger
20108 expressions containing EXPR. */
20111 build_non_dependent_expr (tree expr)
20115 #ifdef ENABLE_CHECKING
20116 /* Try to get a constant value for all non-type-dependent expressions in
20117 order to expose bugs in *_dependent_expression_p and constexpr. */
20118 if (cxx_dialect >= cxx0x)
20119 maybe_constant_value (fold_non_dependent_expr_sfinae (expr, tf_none));
20122 /* Preserve OVERLOADs; the functions must be available to resolve
20125 if (TREE_CODE (inner_expr) == STMT_EXPR)
20126 inner_expr = stmt_expr_value_expr (inner_expr);
20127 if (TREE_CODE (inner_expr) == ADDR_EXPR)
20128 inner_expr = TREE_OPERAND (inner_expr, 0);
20129 if (TREE_CODE (inner_expr) == COMPONENT_REF)
20130 inner_expr = TREE_OPERAND (inner_expr, 1);
20131 if (is_overloaded_fn (inner_expr)
20132 || TREE_CODE (inner_expr) == OFFSET_REF)
20134 /* There is no need to return a proxy for a variable. */
20135 if (TREE_CODE (expr) == VAR_DECL)
20137 /* Preserve string constants; conversions from string constants to
20138 "char *" are allowed, even though normally a "const char *"
20139 cannot be used to initialize a "char *". */
20140 if (TREE_CODE (expr) == STRING_CST)
20142 /* Preserve arithmetic constants, as an optimization -- there is no
20143 reason to create a new node. */
20144 if (TREE_CODE (expr) == INTEGER_CST || TREE_CODE (expr) == REAL_CST)
20146 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
20147 There is at least one place where we want to know that a
20148 particular expression is a throw-expression: when checking a ?:
20149 expression, there are special rules if the second or third
20150 argument is a throw-expression. */
20151 if (TREE_CODE (expr) == THROW_EXPR)
20154 /* Don't wrap an initializer list, we need to be able to look inside. */
20155 if (BRACE_ENCLOSED_INITIALIZER_P (expr))
20158 if (TREE_CODE (expr) == COND_EXPR)
20159 return build3 (COND_EXPR,
20161 TREE_OPERAND (expr, 0),
20162 (TREE_OPERAND (expr, 1)
20163 ? build_non_dependent_expr (TREE_OPERAND (expr, 1))
20164 : build_non_dependent_expr (TREE_OPERAND (expr, 0))),
20165 build_non_dependent_expr (TREE_OPERAND (expr, 2)));
20166 if (TREE_CODE (expr) == COMPOUND_EXPR
20167 && !COMPOUND_EXPR_OVERLOADED (expr))
20168 return build2 (COMPOUND_EXPR,
20170 TREE_OPERAND (expr, 0),
20171 build_non_dependent_expr (TREE_OPERAND (expr, 1)));
20173 /* If the type is unknown, it can't really be non-dependent */
20174 gcc_assert (TREE_TYPE (expr) != unknown_type_node);
20176 /* Otherwise, build a NON_DEPENDENT_EXPR. */
20177 return build1 (NON_DEPENDENT_EXPR, TREE_TYPE (expr), expr);
20180 /* ARGS is a vector of expressions as arguments to a function call.
20181 Replace the arguments with equivalent non-dependent expressions.
20182 This modifies ARGS in place. */
20185 make_args_non_dependent (VEC(tree,gc) *args)
20190 FOR_EACH_VEC_ELT (tree, args, ix, arg)
20192 tree newarg = build_non_dependent_expr (arg);
20194 VEC_replace (tree, args, ix, newarg);
20198 /* Returns a type which represents 'auto'. We use a TEMPLATE_TYPE_PARM
20199 with a level one deeper than the actual template parms. */
20204 tree au = cxx_make_type (TEMPLATE_TYPE_PARM);
20205 TYPE_NAME (au) = build_decl (BUILTINS_LOCATION,
20206 TYPE_DECL, get_identifier ("auto"), au);
20207 TYPE_STUB_DECL (au) = TYPE_NAME (au);
20208 TEMPLATE_TYPE_PARM_INDEX (au) = build_template_parm_index
20209 (0, processing_template_decl + 1, processing_template_decl + 1,
20210 0, TYPE_NAME (au), NULL_TREE);
20211 TYPE_CANONICAL (au) = canonical_type_parameter (au);
20212 DECL_ARTIFICIAL (TYPE_NAME (au)) = 1;
20213 SET_DECL_TEMPLATE_PARM_P (TYPE_NAME (au));
20218 /* Given type ARG, return std::initializer_list<ARG>. */
20223 tree std_init_list = namespace_binding
20224 (get_identifier ("initializer_list"), std_node);
20226 if (!std_init_list || !DECL_CLASS_TEMPLATE_P (std_init_list))
20228 error ("deducing from brace-enclosed initializer list requires "
20229 "#include <initializer_list>");
20230 return error_mark_node;
20232 argvec = make_tree_vec (1);
20233 TREE_VEC_ELT (argvec, 0) = arg;
20234 return lookup_template_class (std_init_list, argvec, NULL_TREE,
20235 NULL_TREE, 0, tf_warning_or_error);
20238 /* Replace auto in TYPE with std::initializer_list<auto>. */
20241 listify_autos (tree type, tree auto_node)
20243 tree init_auto = listify (auto_node);
20244 tree argvec = make_tree_vec (1);
20245 TREE_VEC_ELT (argvec, 0) = init_auto;
20246 if (processing_template_decl)
20247 argvec = add_to_template_args (current_template_args (), argvec);
20248 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
20251 /* walk_tree helper for do_auto_deduction. */
20254 contains_auto_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
20257 /* Is this a variable with the type we're looking for? */
20259 && TREE_TYPE (*tp) == type)
20265 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
20266 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
20269 do_auto_deduction (tree type, tree init, tree auto_node)
20271 tree parms, tparms, targs;
20276 if (processing_template_decl
20277 && (TREE_TYPE (init) == NULL_TREE
20278 || BRACE_ENCLOSED_INITIALIZER_P (init)))
20279 /* Not enough information to try this yet. */
20282 /* The name of the object being declared shall not appear in the
20283 initializer expression. */
20284 decl = cp_walk_tree_without_duplicates (&init, contains_auto_r, type);
20287 error ("variable %q#D with %<auto%> type used in its own "
20288 "initializer", decl);
20289 return error_mark_node;
20292 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
20293 with either a new invented type template parameter U or, if the
20294 initializer is a braced-init-list (8.5.4), with
20295 std::initializer_list<U>. */
20296 if (BRACE_ENCLOSED_INITIALIZER_P (init))
20297 type = listify_autos (type, auto_node);
20299 init = resolve_nondeduced_context (init);
20301 parms = build_tree_list (NULL_TREE, type);
20303 tparms = make_tree_vec (1);
20304 targs = make_tree_vec (1);
20305 TREE_VEC_ELT (tparms, 0)
20306 = build_tree_list (NULL_TREE, TYPE_NAME (auto_node));
20307 val = type_unification_real (tparms, targs, parms, args, 1, 0,
20308 DEDUCE_CALL, LOOKUP_NORMAL,
20309 /*explain_p=*/false);
20312 if (processing_template_decl)
20313 /* Try again at instantiation time. */
20315 if (type && type != error_mark_node)
20316 /* If type is error_mark_node a diagnostic must have been
20317 emitted by now. Also, having a mention to '<type error>'
20318 in the diagnostic is not really useful to the user. */
20319 error ("unable to deduce %qT from %qE", type, init);
20320 return error_mark_node;
20323 /* If the list of declarators contains more than one declarator, the type
20324 of each declared variable is determined as described above. If the
20325 type deduced for the template parameter U is not the same in each
20326 deduction, the program is ill-formed. */
20327 if (TREE_TYPE (auto_node)
20328 && !same_type_p (TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0)))
20330 error ("inconsistent deduction for %qT: %qT and then %qT",
20331 auto_node, TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0));
20332 return error_mark_node;
20334 TREE_TYPE (auto_node) = TREE_VEC_ELT (targs, 0);
20336 if (processing_template_decl)
20337 targs = add_to_template_args (current_template_args (), targs);
20338 return tsubst (type, targs, tf_warning_or_error, NULL_TREE);
20341 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
20345 splice_late_return_type (tree type, tree late_return_type)
20349 if (late_return_type == NULL_TREE)
20351 argvec = make_tree_vec (1);
20352 TREE_VEC_ELT (argvec, 0) = late_return_type;
20353 if (processing_template_parmlist)
20354 /* For a late-specified return type in a template type-parameter, we
20355 need to add a dummy argument level for its parmlist. */
20356 argvec = add_to_template_args
20357 (make_tree_vec (processing_template_parmlist), argvec);
20358 if (current_template_parms)
20359 argvec = add_to_template_args (current_template_args (), argvec);
20360 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
20363 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto'. */
20366 is_auto (const_tree type)
20368 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
20369 && TYPE_IDENTIFIER (type) == get_identifier ("auto"))
20375 /* Returns true iff TYPE contains a use of 'auto'. Since auto can only
20376 appear as a type-specifier for the declaration in question, we don't
20377 have to look through the whole type. */
20380 type_uses_auto (tree type)
20382 enum tree_code code;
20383 if (is_auto (type))
20386 code = TREE_CODE (type);
20388 if (code == POINTER_TYPE || code == REFERENCE_TYPE
20389 || code == OFFSET_TYPE || code == FUNCTION_TYPE
20390 || code == METHOD_TYPE || code == ARRAY_TYPE)
20391 return type_uses_auto (TREE_TYPE (type));
20393 if (TYPE_PTRMEMFUNC_P (type))
20394 return type_uses_auto (TREE_TYPE (TREE_TYPE
20395 (TYPE_PTRMEMFUNC_FN_TYPE (type))));
20400 /* For a given template T, return the vector of typedefs referenced
20401 in T for which access check is needed at T instantiation time.
20402 T is either a FUNCTION_DECL or a RECORD_TYPE.
20403 Those typedefs were added to T by the function
20404 append_type_to_template_for_access_check. */
20406 VEC(qualified_typedef_usage_t,gc)*
20407 get_types_needing_access_check (tree t)
20410 VEC(qualified_typedef_usage_t,gc) *result = NULL;
20412 if (!t || t == error_mark_node)
20415 if (!(ti = get_template_info (t)))
20418 if (CLASS_TYPE_P (t)
20419 || TREE_CODE (t) == FUNCTION_DECL)
20421 if (!TI_TEMPLATE (ti))
20424 result = TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti);
20430 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
20431 tied to T. That list of typedefs will be access checked at
20432 T instantiation time.
20433 T is either a FUNCTION_DECL or a RECORD_TYPE.
20434 TYPE_DECL is a TYPE_DECL node representing a typedef.
20435 SCOPE is the scope through which TYPE_DECL is accessed.
20436 LOCATION is the location of the usage point of TYPE_DECL.
20438 This function is a subroutine of
20439 append_type_to_template_for_access_check. */
20442 append_type_to_template_for_access_check_1 (tree t,
20445 location_t location)
20447 qualified_typedef_usage_t typedef_usage;
20450 if (!t || t == error_mark_node)
20453 gcc_assert ((TREE_CODE (t) == FUNCTION_DECL
20454 || CLASS_TYPE_P (t))
20456 && TREE_CODE (type_decl) == TYPE_DECL
20459 if (!(ti = get_template_info (t)))
20462 gcc_assert (TI_TEMPLATE (ti));
20464 typedef_usage.typedef_decl = type_decl;
20465 typedef_usage.context = scope;
20466 typedef_usage.locus = location;
20468 VEC_safe_push (qualified_typedef_usage_t, gc,
20469 TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti),
20473 /* Append TYPE_DECL to the template TEMPL.
20474 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
20475 At TEMPL instanciation time, TYPE_DECL will be checked to see
20476 if it can be accessed through SCOPE.
20477 LOCATION is the location of the usage point of TYPE_DECL.
20479 e.g. consider the following code snippet:
20486 template<class U> struct S
20488 C::myint mi; // <-- usage point of the typedef C::myint
20493 At S<char> instantiation time, we need to check the access of C::myint
20494 In other words, we need to check the access of the myint typedef through
20495 the C scope. For that purpose, this function will add the myint typedef
20496 and the scope C through which its being accessed to a list of typedefs
20497 tied to the template S. That list will be walked at template instantiation
20498 time and access check performed on each typedefs it contains.
20499 Note that this particular code snippet should yield an error because
20500 myint is private to C. */
20503 append_type_to_template_for_access_check (tree templ,
20506 location_t location)
20508 qualified_typedef_usage_t *iter;
20511 gcc_assert (type_decl && (TREE_CODE (type_decl) == TYPE_DECL));
20513 /* Make sure we don't append the type to the template twice. */
20514 FOR_EACH_VEC_ELT (qualified_typedef_usage_t,
20515 get_types_needing_access_check (templ),
20517 if (iter->typedef_decl == type_decl && scope == iter->context)
20520 append_type_to_template_for_access_check_1 (templ, type_decl,
20524 /* Set up the hash tables for template instantiations. */
20527 init_template_processing (void)
20529 decl_specializations = htab_create_ggc (37,
20530 hash_specialization,
20531 eq_specializations,
20533 type_specializations = htab_create_ggc (37,
20534 hash_specialization,
20535 eq_specializations,
20539 /* Print stats about the template hash tables for -fstats. */
20542 print_template_statistics (void)
20544 fprintf (stderr, "decl_specializations: size %ld, %ld elements, "
20545 "%f collisions\n", (long) htab_size (decl_specializations),
20546 (long) htab_elements (decl_specializations),
20547 htab_collisions (decl_specializations));
20548 fprintf (stderr, "type_specializations: size %ld, %ld elements, "
20549 "%f collisions\n", (long) htab_size (type_specializations),
20550 (long) htab_elements (type_specializations),
20551 htab_collisions (type_specializations));
20554 #include "gt-cp-pt.h"