1 /* Handle parameterized types (templates) for GNU C++.
2 Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
3 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010, 2011, 2012
4 Free Software Foundation, Inc.
5 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
6 Rewritten by Jason Merrill (jason@cygnus.com).
8 This file is part of GCC.
10 GCC is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3, or (at your option)
15 GCC is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with GCC; see the file COPYING3. If not see
22 <http://www.gnu.org/licenses/>. */
24 /* Known bugs or deficiencies include:
26 all methods must be provided in header files; can't use a source
27 file that contains only the method templates and "just win". */
31 #include "coretypes.h"
35 #include "pointer-set.h"
38 #include "c-family/c-common.h"
39 #include "c-family/c-objc.h"
40 #include "cp-objcp-common.h"
41 #include "tree-inline.h"
46 #include "tree-iterator.h"
49 /* The type of functions taking a tree, and some additional data, and
51 typedef int (*tree_fn_t) (tree, void*);
53 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
54 instantiations have been deferred, either because their definitions
55 were not yet available, or because we were putting off doing the work. */
56 struct GTY ((chain_next ("%h.next"))) pending_template {
57 struct pending_template *next;
58 struct tinst_level *tinst;
61 static GTY(()) struct pending_template *pending_templates;
62 static GTY(()) struct pending_template *last_pending_template;
64 int processing_template_parmlist;
65 static int template_header_count;
67 static GTY(()) tree saved_trees;
68 static VEC(int,heap) *inline_parm_levels;
70 static GTY(()) struct tinst_level *current_tinst_level;
72 static GTY(()) tree saved_access_scope;
74 /* Live only within one (recursive) call to tsubst_expr. We use
75 this to pass the statement expression node from the STMT_EXPR
76 to the EXPR_STMT that is its result. */
77 static tree cur_stmt_expr;
79 /* A map from local variable declarations in the body of the template
80 presently being instantiated to the corresponding instantiated
82 static htab_t local_specializations;
84 typedef struct GTY(()) spec_entry
91 static GTY ((param_is (spec_entry)))
92 htab_t decl_specializations;
94 static GTY ((param_is (spec_entry)))
95 htab_t type_specializations;
97 /* Contains canonical template parameter types. The vector is indexed by
98 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
99 TREE_LIST, whose TREE_VALUEs contain the canonical template
100 parameters of various types and levels. */
101 static GTY(()) VEC(tree,gc) *canonical_template_parms;
103 #define UNIFY_ALLOW_NONE 0
104 #define UNIFY_ALLOW_MORE_CV_QUAL 1
105 #define UNIFY_ALLOW_LESS_CV_QUAL 2
106 #define UNIFY_ALLOW_DERIVED 4
107 #define UNIFY_ALLOW_INTEGER 8
108 #define UNIFY_ALLOW_OUTER_LEVEL 16
109 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
110 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
112 enum template_base_result {
114 tbr_ambiguous_baseclass,
118 static void push_access_scope (tree);
119 static void pop_access_scope (tree);
120 static void push_deduction_access_scope (tree);
121 static void pop_deduction_access_scope (tree);
122 static bool resolve_overloaded_unification (tree, tree, tree, tree,
123 unification_kind_t, int,
125 static int try_one_overload (tree, tree, tree, tree, tree,
126 unification_kind_t, int, bool, bool);
127 static int unify (tree, tree, tree, tree, int, bool);
128 static void add_pending_template (tree);
129 static tree reopen_tinst_level (struct tinst_level *);
130 static tree tsubst_initializer_list (tree, tree);
131 static tree get_class_bindings (tree, tree, tree);
132 static tree coerce_template_parms (tree, tree, tree, tsubst_flags_t,
134 static void tsubst_enum (tree, tree, tree);
135 static tree add_to_template_args (tree, tree);
136 static tree add_outermost_template_args (tree, tree);
137 static bool check_instantiated_args (tree, tree, tsubst_flags_t);
138 static int maybe_adjust_types_for_deduction (unification_kind_t, tree*, tree*,
140 static int type_unification_real (tree, tree, tree, const tree *,
141 unsigned int, int, unification_kind_t, int,
143 static void note_template_header (int);
144 static tree convert_nontype_argument_function (tree, tree);
145 static tree convert_nontype_argument (tree, tree, tsubst_flags_t);
146 static tree convert_template_argument (tree, tree, tree,
147 tsubst_flags_t, int, tree);
148 static int for_each_template_parm (tree, tree_fn_t, void*,
149 struct pointer_set_t*, bool);
150 static tree expand_template_argument_pack (tree);
151 static tree build_template_parm_index (int, int, int, int, tree, tree);
152 static bool inline_needs_template_parms (tree);
153 static void push_inline_template_parms_recursive (tree, int);
154 static tree retrieve_local_specialization (tree);
155 static void register_local_specialization (tree, tree);
156 static hashval_t hash_specialization (const void *p);
157 static tree reduce_template_parm_level (tree, tree, int, tree, tsubst_flags_t);
158 static int mark_template_parm (tree, void *);
159 static int template_parm_this_level_p (tree, void *);
160 static tree tsubst_friend_function (tree, tree);
161 static tree tsubst_friend_class (tree, tree);
162 static int can_complete_type_without_circularity (tree);
163 static tree get_bindings (tree, tree, tree, bool);
164 static int template_decl_level (tree);
165 static int check_cv_quals_for_unify (int, tree, tree);
166 static void template_parm_level_and_index (tree, int*, int*);
167 static int unify_pack_expansion (tree, tree, tree,
168 tree, unification_kind_t, bool, bool);
169 static tree tsubst_template_arg (tree, tree, tsubst_flags_t, tree);
170 static tree tsubst_template_args (tree, tree, tsubst_flags_t, tree);
171 static tree tsubst_template_parms (tree, tree, tsubst_flags_t);
172 static void regenerate_decl_from_template (tree, tree);
173 static tree most_specialized_class (tree, tree, tsubst_flags_t);
174 static tree tsubst_aggr_type (tree, tree, tsubst_flags_t, tree, int);
175 static tree tsubst_arg_types (tree, tree, tsubst_flags_t, tree);
176 static tree tsubst_function_type (tree, tree, tsubst_flags_t, tree);
177 static bool check_specialization_scope (void);
178 static tree process_partial_specialization (tree);
179 static void set_current_access_from_decl (tree);
180 static enum template_base_result get_template_base (tree, tree, tree, tree,
182 static tree try_class_unification (tree, tree, tree, tree, bool);
183 static int coerce_template_template_parms (tree, tree, tsubst_flags_t,
185 static bool template_template_parm_bindings_ok_p (tree, tree);
186 static int template_args_equal (tree, tree);
187 static void tsubst_default_arguments (tree);
188 static tree for_each_template_parm_r (tree *, int *, void *);
189 static tree copy_default_args_to_explicit_spec_1 (tree, tree);
190 static void copy_default_args_to_explicit_spec (tree);
191 static int invalid_nontype_parm_type_p (tree, tsubst_flags_t);
192 static int eq_local_specializations (const void *, const void *);
193 static bool dependent_template_arg_p (tree);
194 static bool any_template_arguments_need_structural_equality_p (tree);
195 static bool dependent_type_p_r (tree);
196 static tree tsubst_expr (tree, tree, tsubst_flags_t, tree, bool);
197 static tree tsubst_copy (tree, tree, tsubst_flags_t, tree);
198 static tree tsubst_pack_expansion (tree, tree, tsubst_flags_t, tree);
199 static tree tsubst_decl (tree, tree, tsubst_flags_t);
200 static void perform_typedefs_access_check (tree tmpl, tree targs);
201 static void append_type_to_template_for_access_check_1 (tree, tree, tree,
203 static tree listify (tree);
204 static tree listify_autos (tree, tree);
205 static tree template_parm_to_arg (tree t);
206 static bool arg_from_parm_pack_p (tree, tree);
207 static tree current_template_args (void);
208 static tree fixup_template_type_parm_type (tree, int);
209 static tree fixup_template_parm_index (tree, tree, int);
210 static tree tsubst_template_parm (tree, tree, tsubst_flags_t);
212 /* Make the current scope suitable for access checking when we are
213 processing T. T can be FUNCTION_DECL for instantiated function
214 template, or VAR_DECL for static member variable (need by
215 instantiate_decl). */
218 push_access_scope (tree t)
220 gcc_assert (TREE_CODE (t) == FUNCTION_DECL
221 || TREE_CODE (t) == VAR_DECL);
223 if (DECL_FRIEND_CONTEXT (t))
224 push_nested_class (DECL_FRIEND_CONTEXT (t));
225 else if (DECL_CLASS_SCOPE_P (t))
226 push_nested_class (DECL_CONTEXT (t));
228 push_to_top_level ();
230 if (TREE_CODE (t) == FUNCTION_DECL)
232 saved_access_scope = tree_cons
233 (NULL_TREE, current_function_decl, saved_access_scope);
234 current_function_decl = t;
238 /* Restore the scope set up by push_access_scope. T is the node we
242 pop_access_scope (tree t)
244 if (TREE_CODE (t) == FUNCTION_DECL)
246 current_function_decl = TREE_VALUE (saved_access_scope);
247 saved_access_scope = TREE_CHAIN (saved_access_scope);
250 if (DECL_FRIEND_CONTEXT (t) || DECL_CLASS_SCOPE_P (t))
253 pop_from_top_level ();
256 /* Do any processing required when DECL (a member template
257 declaration) is finished. Returns the TEMPLATE_DECL corresponding
258 to DECL, unless it is a specialization, in which case the DECL
259 itself is returned. */
262 finish_member_template_decl (tree decl)
264 if (decl == error_mark_node)
265 return error_mark_node;
267 gcc_assert (DECL_P (decl));
269 if (TREE_CODE (decl) == TYPE_DECL)
273 type = TREE_TYPE (decl);
274 if (type == error_mark_node)
275 return error_mark_node;
276 if (MAYBE_CLASS_TYPE_P (type)
277 && CLASSTYPE_TEMPLATE_INFO (type)
278 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
280 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
281 check_member_template (tmpl);
286 else if (TREE_CODE (decl) == FIELD_DECL)
287 error ("data member %qD cannot be a member template", decl);
288 else if (DECL_TEMPLATE_INFO (decl))
290 if (!DECL_TEMPLATE_SPECIALIZATION (decl))
292 check_member_template (DECL_TI_TEMPLATE (decl));
293 return DECL_TI_TEMPLATE (decl);
299 error ("invalid member template declaration %qD", decl);
301 return error_mark_node;
304 /* Create a template info node. */
307 build_template_info (tree template_decl, tree template_args)
309 tree result = make_node (TEMPLATE_INFO);
310 TI_TEMPLATE (result) = template_decl;
311 TI_ARGS (result) = template_args;
315 /* Return the template info node corresponding to T, whatever T is. */
318 get_template_info (const_tree t)
320 tree tinfo = NULL_TREE;
322 if (!t || t == error_mark_node)
325 if (DECL_P (t) && DECL_LANG_SPECIFIC (t))
326 tinfo = DECL_TEMPLATE_INFO (t);
328 if (!tinfo && DECL_IMPLICIT_TYPEDEF_P (t))
331 if (TAGGED_TYPE_P (t))
332 tinfo = TYPE_TEMPLATE_INFO (t);
333 else if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
334 tinfo = TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (t);
339 /* Returns the template nesting level of the indicated class TYPE.
349 A<T>::B<U> has depth two, while A<T> has depth one.
350 Both A<T>::B<int> and A<int>::B<U> have depth one, if
351 they are instantiations, not specializations.
353 This function is guaranteed to return 0 if passed NULL_TREE so
354 that, for example, `template_class_depth (current_class_type)' is
358 template_class_depth (tree type)
363 type && TREE_CODE (type) != NAMESPACE_DECL;
364 type = (TREE_CODE (type) == FUNCTION_DECL)
365 ? CP_DECL_CONTEXT (type) : CP_TYPE_CONTEXT (type))
367 tree tinfo = get_template_info (type);
369 if (tinfo && PRIMARY_TEMPLATE_P (TI_TEMPLATE (tinfo))
370 && uses_template_parms (INNERMOST_TEMPLATE_ARGS (TI_ARGS (tinfo))))
377 /* Subroutine of maybe_begin_member_template_processing.
378 Returns true if processing DECL needs us to push template parms. */
381 inline_needs_template_parms (tree decl)
383 if (! DECL_TEMPLATE_INFO (decl))
386 return (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (most_general_template (decl)))
387 > (processing_template_decl + DECL_TEMPLATE_SPECIALIZATION (decl)));
390 /* Subroutine of maybe_begin_member_template_processing.
391 Push the template parms in PARMS, starting from LEVELS steps into the
392 chain, and ending at the beginning, since template parms are listed
396 push_inline_template_parms_recursive (tree parmlist, int levels)
398 tree parms = TREE_VALUE (parmlist);
402 push_inline_template_parms_recursive (TREE_CHAIN (parmlist), levels - 1);
404 ++processing_template_decl;
405 current_template_parms
406 = tree_cons (size_int (processing_template_decl),
407 parms, current_template_parms);
408 TEMPLATE_PARMS_FOR_INLINE (current_template_parms) = 1;
410 begin_scope (TREE_VEC_LENGTH (parms) ? sk_template_parms : sk_template_spec,
412 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
414 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
416 if (parm == error_mark_node)
419 gcc_assert (DECL_P (parm));
421 switch (TREE_CODE (parm))
430 /* Make a CONST_DECL as is done in process_template_parm.
431 It is ugly that we recreate this here; the original
432 version built in process_template_parm is no longer
434 tree decl = build_decl (DECL_SOURCE_LOCATION (parm),
435 CONST_DECL, DECL_NAME (parm),
437 DECL_ARTIFICIAL (decl) = 1;
438 TREE_CONSTANT (decl) = 1;
439 TREE_READONLY (decl) = 1;
440 DECL_INITIAL (decl) = DECL_INITIAL (parm);
441 SET_DECL_TEMPLATE_PARM_P (decl);
452 /* Restore the template parameter context for a member template or
453 a friend template defined in a class definition. */
456 maybe_begin_member_template_processing (tree decl)
461 if (inline_needs_template_parms (decl))
463 parms = DECL_TEMPLATE_PARMS (most_general_template (decl));
464 levels = TMPL_PARMS_DEPTH (parms) - processing_template_decl;
466 if (DECL_TEMPLATE_SPECIALIZATION (decl))
469 parms = TREE_CHAIN (parms);
472 push_inline_template_parms_recursive (parms, levels);
475 /* Remember how many levels of template parameters we pushed so that
476 we can pop them later. */
477 VEC_safe_push (int, heap, inline_parm_levels, levels);
480 /* Undo the effects of maybe_begin_member_template_processing. */
483 maybe_end_member_template_processing (void)
488 if (VEC_length (int, inline_parm_levels) == 0)
491 last = VEC_pop (int, inline_parm_levels);
492 for (i = 0; i < last; ++i)
494 --processing_template_decl;
495 current_template_parms = TREE_CHAIN (current_template_parms);
500 /* Return a new template argument vector which contains all of ARGS,
501 but has as its innermost set of arguments the EXTRA_ARGS. */
504 add_to_template_args (tree args, tree extra_args)
511 if (args == NULL_TREE || extra_args == error_mark_node)
514 extra_depth = TMPL_ARGS_DEPTH (extra_args);
515 new_args = make_tree_vec (TMPL_ARGS_DEPTH (args) + extra_depth);
517 for (i = 1; i <= TMPL_ARGS_DEPTH (args); ++i)
518 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (args, i));
520 for (j = 1; j <= extra_depth; ++j, ++i)
521 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (extra_args, j));
526 /* Like add_to_template_args, but only the outermost ARGS are added to
527 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
528 (EXTRA_ARGS) levels are added. This function is used to combine
529 the template arguments from a partial instantiation with the
530 template arguments used to attain the full instantiation from the
531 partial instantiation. */
534 add_outermost_template_args (tree args, tree extra_args)
538 /* If there are more levels of EXTRA_ARGS than there are ARGS,
539 something very fishy is going on. */
540 gcc_assert (TMPL_ARGS_DEPTH (args) >= TMPL_ARGS_DEPTH (extra_args));
542 /* If *all* the new arguments will be the EXTRA_ARGS, just return
544 if (TMPL_ARGS_DEPTH (args) == TMPL_ARGS_DEPTH (extra_args))
547 /* For the moment, we make ARGS look like it contains fewer levels. */
548 TREE_VEC_LENGTH (args) -= TMPL_ARGS_DEPTH (extra_args);
550 new_args = add_to_template_args (args, extra_args);
552 /* Now, we restore ARGS to its full dimensions. */
553 TREE_VEC_LENGTH (args) += TMPL_ARGS_DEPTH (extra_args);
558 /* Return the N levels of innermost template arguments from the ARGS. */
561 get_innermost_template_args (tree args, int n)
569 /* If N is 1, just return the innermost set of template arguments. */
571 return TMPL_ARGS_LEVEL (args, TMPL_ARGS_DEPTH (args));
573 /* If we're not removing anything, just return the arguments we were
575 extra_levels = TMPL_ARGS_DEPTH (args) - n;
576 gcc_assert (extra_levels >= 0);
577 if (extra_levels == 0)
580 /* Make a new set of arguments, not containing the outer arguments. */
581 new_args = make_tree_vec (n);
582 for (i = 1; i <= n; ++i)
583 SET_TMPL_ARGS_LEVEL (new_args, i,
584 TMPL_ARGS_LEVEL (args, i + extra_levels));
589 /* The inverse of get_innermost_template_args: Return all but the innermost
590 EXTRA_LEVELS levels of template arguments from the ARGS. */
593 strip_innermost_template_args (tree args, int extra_levels)
596 int n = TMPL_ARGS_DEPTH (args) - extra_levels;
601 /* If N is 1, just return the outermost set of template arguments. */
603 return TMPL_ARGS_LEVEL (args, 1);
605 /* If we're not removing anything, just return the arguments we were
607 gcc_assert (extra_levels >= 0);
608 if (extra_levels == 0)
611 /* Make a new set of arguments, not containing the inner arguments. */
612 new_args = make_tree_vec (n);
613 for (i = 1; i <= n; ++i)
614 SET_TMPL_ARGS_LEVEL (new_args, i,
615 TMPL_ARGS_LEVEL (args, i));
620 /* We've got a template header coming up; push to a new level for storing
624 begin_template_parm_list (void)
626 /* We use a non-tag-transparent scope here, which causes pushtag to
627 put tags in this scope, rather than in the enclosing class or
628 namespace scope. This is the right thing, since we want
629 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
630 global template class, push_template_decl handles putting the
631 TEMPLATE_DECL into top-level scope. For a nested template class,
634 template <class T> struct S1 {
635 template <class T> struct S2 {};
638 pushtag contains special code to call pushdecl_with_scope on the
639 TEMPLATE_DECL for S2. */
640 begin_scope (sk_template_parms, NULL);
641 ++processing_template_decl;
642 ++processing_template_parmlist;
643 note_template_header (0);
646 /* This routine is called when a specialization is declared. If it is
647 invalid to declare a specialization here, an error is reported and
648 false is returned, otherwise this routine will return true. */
651 check_specialization_scope (void)
653 tree scope = current_scope ();
657 An explicit specialization shall be declared in the namespace of
658 which the template is a member, or, for member templates, in the
659 namespace of which the enclosing class or enclosing class
660 template is a member. An explicit specialization of a member
661 function, member class or static data member of a class template
662 shall be declared in the namespace of which the class template
664 if (scope && TREE_CODE (scope) != NAMESPACE_DECL)
666 error ("explicit specialization in non-namespace scope %qD", scope);
672 In an explicit specialization declaration for a member of a class
673 template or a member template that appears in namespace scope,
674 the member template and some of its enclosing class templates may
675 remain unspecialized, except that the declaration shall not
676 explicitly specialize a class member template if its enclosing
677 class templates are not explicitly specialized as well. */
678 if (current_template_parms)
680 error ("enclosing class templates are not explicitly specialized");
687 /* We've just seen template <>. */
690 begin_specialization (void)
692 begin_scope (sk_template_spec, NULL);
693 note_template_header (1);
694 return check_specialization_scope ();
697 /* Called at then end of processing a declaration preceded by
701 end_specialization (void)
704 reset_specialization ();
707 /* Any template <>'s that we have seen thus far are not referring to a
708 function specialization. */
711 reset_specialization (void)
713 processing_specialization = 0;
714 template_header_count = 0;
717 /* We've just seen a template header. If SPECIALIZATION is nonzero,
718 it was of the form template <>. */
721 note_template_header (int specialization)
723 processing_specialization = specialization;
724 template_header_count++;
727 /* We're beginning an explicit instantiation. */
730 begin_explicit_instantiation (void)
732 gcc_assert (!processing_explicit_instantiation);
733 processing_explicit_instantiation = true;
738 end_explicit_instantiation (void)
740 gcc_assert (processing_explicit_instantiation);
741 processing_explicit_instantiation = false;
744 /* An explicit specialization or partial specialization TMPL is being
745 declared. Check that the namespace in which the specialization is
746 occurring is permissible. Returns false iff it is invalid to
747 specialize TMPL in the current namespace. */
750 check_specialization_namespace (tree tmpl)
752 tree tpl_ns = decl_namespace_context (tmpl);
756 An explicit specialization shall be declared in the namespace of
757 which the template is a member, or, for member templates, in the
758 namespace of which the enclosing class or enclosing class
759 template is a member. An explicit specialization of a member
760 function, member class or static data member of a class template
761 shall be declared in the namespace of which the class template is
763 if (current_scope() != DECL_CONTEXT (tmpl)
764 && !at_namespace_scope_p ())
766 error ("specialization of %qD must appear at namespace scope", tmpl);
769 if (is_associated_namespace (current_namespace, tpl_ns))
770 /* Same or super-using namespace. */
774 permerror (input_location, "specialization of %qD in different namespace", tmpl);
775 permerror (input_location, " from definition of %q+#D", tmpl);
780 /* SPEC is an explicit instantiation. Check that it is valid to
781 perform this explicit instantiation in the current namespace. */
784 check_explicit_instantiation_namespace (tree spec)
788 /* DR 275: An explicit instantiation shall appear in an enclosing
789 namespace of its template. */
790 ns = decl_namespace_context (spec);
791 if (!is_ancestor (current_namespace, ns))
792 permerror (input_location, "explicit instantiation of %qD in namespace %qD "
793 "(which does not enclose namespace %qD)",
794 spec, current_namespace, ns);
797 /* The TYPE is being declared. If it is a template type, that means it
798 is a partial specialization. Do appropriate error-checking. */
801 maybe_process_partial_specialization (tree type)
805 if (type == error_mark_node)
806 return error_mark_node;
808 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
810 error ("name of class shadows template template parameter %qD",
812 return error_mark_node;
815 context = TYPE_CONTEXT (type);
817 if ((CLASS_TYPE_P (type) && CLASSTYPE_USE_TEMPLATE (type))
818 /* Consider non-class instantiations of alias templates as
821 && TYPE_TEMPLATE_INFO (type)
822 && DECL_LANG_SPECIFIC (TYPE_NAME (type))
823 && DECL_USE_TEMPLATE (TYPE_NAME (type))))
825 /* This is for ordinary explicit specialization and partial
826 specialization of a template class such as:
828 template <> class C<int>;
832 template <class T> class C<T*>;
834 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
836 if (CLASS_TYPE_P (type)
837 && CLASSTYPE_IMPLICIT_INSTANTIATION (type)
838 && !COMPLETE_TYPE_P (type))
840 check_specialization_namespace (CLASSTYPE_TI_TEMPLATE (type));
841 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
842 if (processing_template_decl)
844 if (push_template_decl (TYPE_MAIN_DECL (type))
846 return error_mark_node;
849 else if (CLASS_TYPE_P (type)
850 && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
851 error ("specialization of %qT after instantiation", type);
853 if (DECL_ALIAS_TEMPLATE_P (TYPE_TI_TEMPLATE (type)))
855 error ("partial specialization of alias template %qD",
856 TYPE_TI_TEMPLATE (type));
857 return error_mark_node;
860 else if (CLASS_TYPE_P (type)
861 && !CLASSTYPE_USE_TEMPLATE (type)
862 && CLASSTYPE_TEMPLATE_INFO (type)
863 && context && CLASS_TYPE_P (context)
864 && CLASSTYPE_TEMPLATE_INFO (context))
866 /* This is for an explicit specialization of member class
867 template according to [temp.expl.spec/18]:
869 template <> template <class U> class C<int>::D;
871 The context `C<int>' must be an implicit instantiation.
872 Otherwise this is just a member class template declared
875 template <> class C<int> { template <class U> class D; };
876 template <> template <class U> class C<int>::D;
878 In the first case, `C<int>::D' is a specialization of `C<T>::D'
879 while in the second case, `C<int>::D' is a primary template
880 and `C<T>::D' may not exist. */
882 if (CLASSTYPE_IMPLICIT_INSTANTIATION (context)
883 && !COMPLETE_TYPE_P (type))
886 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
888 if (current_namespace
889 != decl_namespace_context (tmpl))
891 permerror (input_location, "specializing %q#T in different namespace", type);
892 permerror (input_location, " from definition of %q+#D", tmpl);
895 /* Check for invalid specialization after instantiation:
897 template <> template <> class C<int>::D<int>;
898 template <> template <class U> class C<int>::D; */
900 for (t = DECL_TEMPLATE_INSTANTIATIONS (tmpl);
901 t; t = TREE_CHAIN (t))
903 tree inst = TREE_VALUE (t);
904 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (inst))
906 /* We already have a full specialization of this partial
907 instantiation. Reassign it to the new member
908 specialization template. */
913 elt.tmpl = most_general_template (tmpl);
914 elt.args = CLASSTYPE_TI_ARGS (inst);
917 htab_remove_elt (type_specializations, &elt);
920 elt.args = INNERMOST_TEMPLATE_ARGS (elt.args);
922 slot = htab_find_slot (type_specializations, &elt, INSERT);
923 entry = ggc_alloc_spec_entry ();
927 else if (COMPLETE_OR_OPEN_TYPE_P (inst))
928 /* But if we've had an implicit instantiation, that's a
929 problem ([temp.expl.spec]/6). */
930 error ("specialization %qT after instantiation %qT",
934 /* Mark TYPE as a specialization. And as a result, we only
935 have one level of template argument for the innermost
937 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
938 CLASSTYPE_TI_ARGS (type)
939 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type));
942 else if (processing_specialization)
944 /* Someday C++0x may allow for enum template specialization. */
945 if (cxx_dialect > cxx98 && TREE_CODE (type) == ENUMERAL_TYPE
946 && CLASS_TYPE_P (context) && CLASSTYPE_USE_TEMPLATE (context))
947 pedwarn (input_location, OPT_pedantic, "template specialization "
948 "of %qD not allowed by ISO C++", type);
951 error ("explicit specialization of non-template %qT", type);
952 return error_mark_node;
959 /* Returns nonzero if we can optimize the retrieval of specializations
960 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
961 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
964 optimize_specialization_lookup_p (tree tmpl)
966 return (DECL_FUNCTION_TEMPLATE_P (tmpl)
967 && DECL_CLASS_SCOPE_P (tmpl)
968 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
970 && CLASS_TYPE_P (DECL_CONTEXT (tmpl))
971 /* The optimized lookup depends on the fact that the
972 template arguments for the member function template apply
973 purely to the containing class, which is not true if the
974 containing class is an explicit or partial
976 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (tmpl))
977 && !DECL_MEMBER_TEMPLATE_P (tmpl)
978 && !DECL_CONV_FN_P (tmpl)
979 /* It is possible to have a template that is not a member
980 template and is not a member of a template class:
982 template <typename T>
983 struct S { friend A::f(); };
985 Here, the friend function is a template, but the context does
986 not have template information. The optimized lookup relies
987 on having ARGS be the template arguments for both the class
988 and the function template. */
989 && !DECL_FRIEND_P (DECL_TEMPLATE_RESULT (tmpl)));
992 /* Retrieve the specialization (in the sense of [temp.spec] - a
993 specialization is either an instantiation or an explicit
994 specialization) of TMPL for the given template ARGS. If there is
995 no such specialization, return NULL_TREE. The ARGS are a vector of
996 arguments, or a vector of vectors of arguments, in the case of
997 templates with more than one level of parameters.
999 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
1000 then we search for a partial specialization matching ARGS. This
1001 parameter is ignored if TMPL is not a class template. */
1004 retrieve_specialization (tree tmpl, tree args, hashval_t hash)
1006 if (args == error_mark_node)
1009 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
1011 /* There should be as many levels of arguments as there are
1012 levels of parameters. */
1013 gcc_assert (TMPL_ARGS_DEPTH (args)
1014 == TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl)));
1016 if (optimize_specialization_lookup_p (tmpl))
1018 tree class_template;
1019 tree class_specialization;
1020 VEC(tree,gc) *methods;
1024 /* The template arguments actually apply to the containing
1025 class. Find the class specialization with those
1027 class_template = CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (tmpl));
1028 class_specialization
1029 = retrieve_specialization (class_template, args, 0);
1030 if (!class_specialization)
1032 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
1033 for the specialization. */
1034 idx = class_method_index_for_fn (class_specialization, tmpl);
1037 /* Iterate through the methods with the indicated name, looking
1038 for the one that has an instance of TMPL. */
1039 methods = CLASSTYPE_METHOD_VEC (class_specialization);
1040 for (fns = VEC_index (tree, methods, idx); fns; fns = OVL_NEXT (fns))
1042 tree fn = OVL_CURRENT (fns);
1043 if (DECL_TEMPLATE_INFO (fn) && DECL_TI_TEMPLATE (fn) == tmpl
1044 /* using-declarations can add base methods to the method vec,
1045 and we don't want those here. */
1046 && DECL_CONTEXT (fn) == class_specialization)
1055 htab_t specializations;
1059 elt.spec = NULL_TREE;
1061 if (DECL_CLASS_TEMPLATE_P (tmpl))
1062 specializations = type_specializations;
1064 specializations = decl_specializations;
1067 hash = hash_specialization (&elt);
1068 found = (spec_entry *) htab_find_with_hash (specializations, &elt, hash);
1076 /* Like retrieve_specialization, but for local declarations. */
1079 retrieve_local_specialization (tree tmpl)
1083 if (local_specializations == NULL)
1086 spec = (tree) htab_find_with_hash (local_specializations, tmpl,
1087 htab_hash_pointer (tmpl));
1088 return spec ? TREE_PURPOSE (spec) : NULL_TREE;
1091 /* Returns nonzero iff DECL is a specialization of TMPL. */
1094 is_specialization_of (tree decl, tree tmpl)
1098 if (TREE_CODE (decl) == FUNCTION_DECL)
1102 t = DECL_TEMPLATE_INFO (t) ? DECL_TI_TEMPLATE (t) : NULL_TREE)
1108 gcc_assert (TREE_CODE (decl) == TYPE_DECL);
1110 for (t = TREE_TYPE (decl);
1112 t = CLASSTYPE_USE_TEMPLATE (t)
1113 ? TREE_TYPE (CLASSTYPE_TI_TEMPLATE (t)) : NULL_TREE)
1114 if (same_type_ignoring_top_level_qualifiers_p (t, TREE_TYPE (tmpl)))
1121 /* Returns nonzero iff DECL is a specialization of friend declaration
1122 FRIEND_DECL according to [temp.friend]. */
1125 is_specialization_of_friend (tree decl, tree friend_decl)
1127 bool need_template = true;
1130 gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
1131 || TREE_CODE (decl) == TYPE_DECL);
1133 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1134 of a template class, we want to check if DECL is a specialization
1136 if (TREE_CODE (friend_decl) == FUNCTION_DECL
1137 && DECL_TEMPLATE_INFO (friend_decl)
1138 && !DECL_USE_TEMPLATE (friend_decl))
1140 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1141 friend_decl = DECL_TI_TEMPLATE (friend_decl);
1142 need_template = false;
1144 else if (TREE_CODE (friend_decl) == TEMPLATE_DECL
1145 && !PRIMARY_TEMPLATE_P (friend_decl))
1146 need_template = false;
1148 /* There is nothing to do if this is not a template friend. */
1149 if (TREE_CODE (friend_decl) != TEMPLATE_DECL)
1152 if (is_specialization_of (decl, friend_decl))
1156 A member of a class template may be declared to be a friend of a
1157 non-template class. In this case, the corresponding member of
1158 every specialization of the class template is a friend of the
1159 class granting friendship.
1161 For example, given a template friend declaration
1163 template <class T> friend void A<T>::f();
1165 the member function below is considered a friend
1167 template <> struct A<int> {
1171 For this type of template friend, TEMPLATE_DEPTH below will be
1172 nonzero. To determine if DECL is a friend of FRIEND, we first
1173 check if the enclosing class is a specialization of another. */
1175 template_depth = template_class_depth (CP_DECL_CONTEXT (friend_decl));
1177 && DECL_CLASS_SCOPE_P (decl)
1178 && is_specialization_of (TYPE_NAME (DECL_CONTEXT (decl)),
1179 CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (friend_decl))))
1181 /* Next, we check the members themselves. In order to handle
1182 a few tricky cases, such as when FRIEND_DECL's are
1184 template <class T> friend void A<T>::g(T t);
1185 template <class T> template <T t> friend void A<T>::h();
1189 void A<int>::g(int);
1190 template <int> void A<int>::h();
1192 we need to figure out ARGS, the template arguments from
1193 the context of DECL. This is required for template substitution
1194 of `T' in the function parameter of `g' and template parameter
1195 of `h' in the above examples. Here ARGS corresponds to `int'. */
1197 tree context = DECL_CONTEXT (decl);
1198 tree args = NULL_TREE;
1199 int current_depth = 0;
1201 while (current_depth < template_depth)
1203 if (CLASSTYPE_TEMPLATE_INFO (context))
1205 if (current_depth == 0)
1206 args = TYPE_TI_ARGS (context);
1208 args = add_to_template_args (TYPE_TI_ARGS (context), args);
1211 context = TYPE_CONTEXT (context);
1214 if (TREE_CODE (decl) == FUNCTION_DECL)
1219 tree friend_args_type;
1220 tree decl_args_type;
1222 /* Make sure that both DECL and FRIEND_DECL are templates or
1224 is_template = DECL_TEMPLATE_INFO (decl)
1225 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (decl));
1226 if (need_template ^ is_template)
1228 else if (is_template)
1230 /* If both are templates, check template parameter list. */
1232 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1234 if (!comp_template_parms
1235 (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (decl)),
1239 decl_type = TREE_TYPE (DECL_TI_TEMPLATE (decl));
1242 decl_type = TREE_TYPE (decl);
1244 friend_type = tsubst_function_type (TREE_TYPE (friend_decl), args,
1245 tf_none, NULL_TREE);
1246 if (friend_type == error_mark_node)
1249 /* Check if return types match. */
1250 if (!same_type_p (TREE_TYPE (decl_type), TREE_TYPE (friend_type)))
1253 /* Check if function parameter types match, ignoring the
1254 `this' parameter. */
1255 friend_args_type = TYPE_ARG_TYPES (friend_type);
1256 decl_args_type = TYPE_ARG_TYPES (decl_type);
1257 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (friend_decl))
1258 friend_args_type = TREE_CHAIN (friend_args_type);
1259 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1260 decl_args_type = TREE_CHAIN (decl_args_type);
1262 return compparms (decl_args_type, friend_args_type);
1266 /* DECL is a TYPE_DECL */
1268 tree decl_type = TREE_TYPE (decl);
1270 /* Make sure that both DECL and FRIEND_DECL are templates or
1273 = CLASSTYPE_TEMPLATE_INFO (decl_type)
1274 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (decl_type));
1276 if (need_template ^ is_template)
1278 else if (is_template)
1281 /* If both are templates, check the name of the two
1282 TEMPLATE_DECL's first because is_friend didn't. */
1283 if (DECL_NAME (CLASSTYPE_TI_TEMPLATE (decl_type))
1284 != DECL_NAME (friend_decl))
1287 /* Now check template parameter list. */
1289 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1291 return comp_template_parms
1292 (DECL_TEMPLATE_PARMS (CLASSTYPE_TI_TEMPLATE (decl_type)),
1296 return (DECL_NAME (decl)
1297 == DECL_NAME (friend_decl));
1303 /* Register the specialization SPEC as a specialization of TMPL with
1304 the indicated ARGS. IS_FRIEND indicates whether the specialization
1305 is actually just a friend declaration. Returns SPEC, or an
1306 equivalent prior declaration, if available. */
1309 register_specialization (tree spec, tree tmpl, tree args, bool is_friend,
1316 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL && DECL_P (spec));
1318 if (TREE_CODE (spec) == FUNCTION_DECL
1319 && uses_template_parms (DECL_TI_ARGS (spec)))
1320 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1321 register it; we want the corresponding TEMPLATE_DECL instead.
1322 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1323 the more obvious `uses_template_parms (spec)' to avoid problems
1324 with default function arguments. In particular, given
1325 something like this:
1327 template <class T> void f(T t1, T t = T())
1329 the default argument expression is not substituted for in an
1330 instantiation unless and until it is actually needed. */
1333 if (optimize_specialization_lookup_p (tmpl))
1334 /* We don't put these specializations in the hash table, but we might
1335 want to give an error about a mismatch. */
1336 fn = retrieve_specialization (tmpl, args, 0);
1344 hash = hash_specialization (&elt);
1347 htab_find_slot_with_hash (decl_specializations, &elt, hash, INSERT);
1349 fn = ((spec_entry *) *slot)->spec;
1354 /* We can sometimes try to re-register a specialization that we've
1355 already got. In particular, regenerate_decl_from_template calls
1356 duplicate_decls which will update the specialization list. But,
1357 we'll still get called again here anyhow. It's more convenient
1358 to simply allow this than to try to prevent it. */
1361 else if (fn && DECL_TEMPLATE_SPECIALIZATION (spec))
1363 if (DECL_TEMPLATE_INSTANTIATION (fn))
1365 if (DECL_ODR_USED (fn)
1366 || DECL_EXPLICIT_INSTANTIATION (fn))
1368 error ("specialization of %qD after instantiation",
1370 return error_mark_node;
1375 /* This situation should occur only if the first
1376 specialization is an implicit instantiation, the
1377 second is an explicit specialization, and the
1378 implicit instantiation has not yet been used. That
1379 situation can occur if we have implicitly
1380 instantiated a member function and then specialized
1383 We can also wind up here if a friend declaration that
1384 looked like an instantiation turns out to be a
1387 template <class T> void foo(T);
1388 class S { friend void foo<>(int) };
1389 template <> void foo(int);
1391 We transform the existing DECL in place so that any
1392 pointers to it become pointers to the updated
1395 If there was a definition for the template, but not
1396 for the specialization, we want this to look as if
1397 there were no definition, and vice versa. */
1398 DECL_INITIAL (fn) = NULL_TREE;
1399 duplicate_decls (spec, fn, is_friend);
1400 /* The call to duplicate_decls will have applied
1403 An explicit specialization of a function template
1404 is inline only if it is explicitly declared to be,
1405 and independently of whether its function template
1408 to the primary function; now copy the inline bits to
1409 the various clones. */
1410 FOR_EACH_CLONE (clone, fn)
1412 DECL_DECLARED_INLINE_P (clone)
1413 = DECL_DECLARED_INLINE_P (fn);
1414 DECL_SOURCE_LOCATION (clone)
1415 = DECL_SOURCE_LOCATION (fn);
1417 check_specialization_namespace (fn);
1422 else if (DECL_TEMPLATE_SPECIALIZATION (fn))
1424 if (!duplicate_decls (spec, fn, is_friend) && DECL_INITIAL (spec))
1425 /* Dup decl failed, but this is a new definition. Set the
1426 line number so any errors match this new
1428 DECL_SOURCE_LOCATION (fn) = DECL_SOURCE_LOCATION (spec);
1434 return duplicate_decls (spec, fn, is_friend);
1436 /* A specialization must be declared in the same namespace as the
1437 template it is specializing. */
1438 if (DECL_TEMPLATE_SPECIALIZATION (spec)
1439 && !check_specialization_namespace (tmpl))
1440 DECL_CONTEXT (spec) = DECL_CONTEXT (tmpl);
1442 if (slot != NULL /* !optimize_specialization_lookup_p (tmpl) */)
1444 spec_entry *entry = ggc_alloc_spec_entry ();
1445 gcc_assert (tmpl && args && spec);
1448 if (TREE_CODE (spec) == FUNCTION_DECL && DECL_NAMESPACE_SCOPE_P (spec)
1449 && PRIMARY_TEMPLATE_P (tmpl)
1450 && DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (tmpl)) == NULL_TREE)
1451 /* TMPL is a forward declaration of a template function; keep a list
1452 of all specializations in case we need to reassign them to a friend
1453 template later in tsubst_friend_function. */
1454 DECL_TEMPLATE_INSTANTIATIONS (tmpl)
1455 = tree_cons (args, spec, DECL_TEMPLATE_INSTANTIATIONS (tmpl));
1461 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1462 TMPL and ARGS members, ignores SPEC. */
1465 eq_specializations (const void *p1, const void *p2)
1467 const spec_entry *e1 = (const spec_entry *)p1;
1468 const spec_entry *e2 = (const spec_entry *)p2;
1470 return (e1->tmpl == e2->tmpl
1471 && comp_template_args (e1->args, e2->args));
1474 /* Returns a hash for a template TMPL and template arguments ARGS. */
1477 hash_tmpl_and_args (tree tmpl, tree args)
1479 hashval_t val = DECL_UID (tmpl);
1480 return iterative_hash_template_arg (args, val);
1483 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1487 hash_specialization (const void *p)
1489 const spec_entry *e = (const spec_entry *)p;
1490 return hash_tmpl_and_args (e->tmpl, e->args);
1493 /* Recursively calculate a hash value for a template argument ARG, for use
1494 in the hash tables of template specializations. */
1497 iterative_hash_template_arg (tree arg, hashval_t val)
1499 unsigned HOST_WIDE_INT i;
1500 enum tree_code code;
1503 if (arg == NULL_TREE)
1504 return iterative_hash_object (arg, val);
1509 if (TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
1510 /* We can get one of these when re-hashing a previous entry in the middle
1511 of substituting into a pack expansion. Just look through it. */
1512 arg = ARGUMENT_PACK_SELECT_FROM_PACK (arg);
1514 code = TREE_CODE (arg);
1515 tclass = TREE_CODE_CLASS (code);
1517 val = iterative_hash_object (code, val);
1524 case IDENTIFIER_NODE:
1525 return iterative_hash_object (IDENTIFIER_HASH_VALUE (arg), val);
1529 int i, len = TREE_VEC_LENGTH (arg);
1530 for (i = 0; i < len; ++i)
1531 val = iterative_hash_template_arg (TREE_VEC_ELT (arg, i), val);
1535 case TYPE_PACK_EXPANSION:
1536 case EXPR_PACK_EXPANSION:
1537 val = iterative_hash_template_arg (PACK_EXPANSION_PATTERN (arg), val);
1538 return iterative_hash_template_arg (PACK_EXPANSION_EXTRA_ARGS (arg), val);
1540 case TYPE_ARGUMENT_PACK:
1541 case NONTYPE_ARGUMENT_PACK:
1542 return iterative_hash_template_arg (ARGUMENT_PACK_ARGS (arg), val);
1545 for (; arg; arg = TREE_CHAIN (arg))
1546 val = iterative_hash_template_arg (TREE_VALUE (arg), val);
1550 for (; arg; arg = OVL_NEXT (arg))
1551 val = iterative_hash_template_arg (OVL_CURRENT (arg), val);
1557 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg), i, field, value)
1559 val = iterative_hash_template_arg (field, val);
1560 val = iterative_hash_template_arg (value, val);
1566 if (!DECL_ARTIFICIAL (arg))
1568 val = iterative_hash_object (DECL_PARM_INDEX (arg), val);
1569 val = iterative_hash_object (DECL_PARM_LEVEL (arg), val);
1571 return iterative_hash_template_arg (TREE_TYPE (arg), val);
1574 return iterative_hash_template_arg (TARGET_EXPR_INITIAL (arg), val);
1577 val = iterative_hash_template_arg (PTRMEM_CST_CLASS (arg), val);
1578 return iterative_hash_template_arg (PTRMEM_CST_MEMBER (arg), val);
1580 case TEMPLATE_PARM_INDEX:
1581 val = iterative_hash_template_arg
1582 (TREE_TYPE (TEMPLATE_PARM_DECL (arg)), val);
1583 val = iterative_hash_object (TEMPLATE_PARM_LEVEL (arg), val);
1584 return iterative_hash_object (TEMPLATE_PARM_IDX (arg), val);
1587 val = iterative_hash_object (TRAIT_EXPR_KIND (arg), val);
1588 val = iterative_hash_template_arg (TRAIT_EXPR_TYPE1 (arg), val);
1589 return iterative_hash_template_arg (TRAIT_EXPR_TYPE2 (arg), val);
1592 val = iterative_hash_template_arg (BINFO_TYPE (BASELINK_BINFO (arg)),
1594 return iterative_hash_template_arg (DECL_NAME (get_first_fn (arg)),
1598 val = iterative_hash_template_arg (TREE_OPERAND (arg, 0), val);
1599 code = TREE_CODE (TREE_OPERAND (arg, 1));
1600 val = iterative_hash_object (code, val);
1601 return iterative_hash_template_arg (TREE_OPERAND (arg, 2), val);
1604 /* A lambda can't appear in a template arg, but don't crash on
1606 gcc_assert (seen_error ());
1610 case IMPLICIT_CONV_EXPR:
1611 case STATIC_CAST_EXPR:
1612 case REINTERPRET_CAST_EXPR:
1613 case CONST_CAST_EXPR:
1614 case DYNAMIC_CAST_EXPR:
1616 val = iterative_hash_template_arg (TREE_TYPE (arg), val);
1617 /* Now hash operands as usual. */
1627 if (TYPE_CANONICAL (arg))
1628 return iterative_hash_object (TYPE_HASH (TYPE_CANONICAL (arg)),
1630 else if (TREE_CODE (arg) == DECLTYPE_TYPE)
1631 return iterative_hash_template_arg (DECLTYPE_TYPE_EXPR (arg), val);
1632 /* Otherwise just compare the types during lookup. */
1635 case tcc_declaration:
1637 return iterative_hash_expr (arg, val);
1640 gcc_assert (IS_EXPR_CODE_CLASS (tclass));
1642 unsigned n = cp_tree_operand_length (arg);
1643 for (i = 0; i < n; ++i)
1644 val = iterative_hash_template_arg (TREE_OPERAND (arg, i), val);
1652 /* Unregister the specialization SPEC as a specialization of TMPL.
1653 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1654 if the SPEC was listed as a specialization of TMPL.
1656 Note that SPEC has been ggc_freed, so we can't look inside it. */
1659 reregister_specialization (tree spec, tree tinfo, tree new_spec)
1664 elt.tmpl = most_general_template (TI_TEMPLATE (tinfo));
1665 elt.args = TI_ARGS (tinfo);
1666 elt.spec = NULL_TREE;
1668 entry = (spec_entry *) htab_find (decl_specializations, &elt);
1671 gcc_assert (entry->spec == spec || entry->spec == new_spec);
1672 gcc_assert (new_spec != NULL_TREE);
1673 entry->spec = new_spec;
1680 /* Compare an entry in the local specializations hash table P1 (which
1681 is really a pointer to a TREE_LIST) with P2 (which is really a
1685 eq_local_specializations (const void *p1, const void *p2)
1687 return TREE_VALUE ((const_tree) p1) == (const_tree) p2;
1690 /* Hash P1, an entry in the local specializations table. */
1693 hash_local_specialization (const void* p1)
1695 return htab_hash_pointer (TREE_VALUE ((const_tree) p1));
1698 /* Like register_specialization, but for local declarations. We are
1699 registering SPEC, an instantiation of TMPL. */
1702 register_local_specialization (tree spec, tree tmpl)
1706 slot = htab_find_slot_with_hash (local_specializations, tmpl,
1707 htab_hash_pointer (tmpl), INSERT);
1708 *slot = build_tree_list (spec, tmpl);
1711 /* TYPE is a class type. Returns true if TYPE is an explicitly
1712 specialized class. */
1715 explicit_class_specialization_p (tree type)
1717 if (!CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
1719 return !uses_template_parms (CLASSTYPE_TI_ARGS (type));
1722 /* Print the list of functions at FNS, going through all the overloads
1723 for each element of the list. Alternatively, FNS can not be a
1724 TREE_LIST, in which case it will be printed together with all the
1727 MORE and *STR should respectively be FALSE and NULL when the function
1728 is called from the outside. They are used internally on recursive
1729 calls. print_candidates manages the two parameters and leaves NULL
1730 in *STR when it ends. */
1733 print_candidates_1 (tree fns, bool more, const char **str)
1736 char *spaces = NULL;
1738 for (fn = fns; fn; fn = OVL_NEXT (fn))
1739 if (TREE_CODE (fn) == TREE_LIST)
1741 for (fn2 = fn; fn2 != NULL_TREE; fn2 = TREE_CHAIN (fn2))
1742 print_candidates_1 (TREE_VALUE (fn2),
1743 TREE_CHAIN (fn2) || more, str);
1749 /* Pick the prefix string. */
1750 if (!more && !OVL_NEXT (fns))
1752 error ("candidate is: %+#D", OVL_CURRENT (fn));
1756 *str = _("candidates are:");
1757 spaces = get_spaces (*str);
1759 error ("%s %+#D", *str, OVL_CURRENT (fn));
1760 *str = spaces ? spaces : *str;
1770 /* Print the list of candidate FNS in an error message. FNS can also
1771 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1774 print_candidates (tree fns)
1776 const char *str = NULL;
1777 print_candidates_1 (fns, false, &str);
1778 gcc_assert (str == NULL);
1781 /* Returns the template (one of the functions given by TEMPLATE_ID)
1782 which can be specialized to match the indicated DECL with the
1783 explicit template args given in TEMPLATE_ID. The DECL may be
1784 NULL_TREE if none is available. In that case, the functions in
1785 TEMPLATE_ID are non-members.
1787 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1788 specialization of a member template.
1790 The TEMPLATE_COUNT is the number of references to qualifying
1791 template classes that appeared in the name of the function. See
1792 check_explicit_specialization for a more accurate description.
1794 TSK indicates what kind of template declaration (if any) is being
1795 declared. TSK_TEMPLATE indicates that the declaration given by
1796 DECL, though a FUNCTION_DECL, has template parameters, and is
1797 therefore a template function.
1799 The template args (those explicitly specified and those deduced)
1800 are output in a newly created vector *TARGS_OUT.
1802 If it is impossible to determine the result, an error message is
1803 issued. The error_mark_node is returned to indicate failure. */
1806 determine_specialization (tree template_id,
1809 int need_member_template,
1815 tree explicit_targs;
1816 tree candidates = NULL_TREE;
1817 /* A TREE_LIST of templates of which DECL may be a specialization.
1818 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1819 corresponding TREE_PURPOSE is the set of template arguments that,
1820 when used to instantiate the template, would produce a function
1821 with the signature of DECL. */
1822 tree templates = NULL_TREE;
1824 cp_binding_level *b;
1826 *targs_out = NULL_TREE;
1828 if (template_id == error_mark_node || decl == error_mark_node)
1829 return error_mark_node;
1831 fns = TREE_OPERAND (template_id, 0);
1832 explicit_targs = TREE_OPERAND (template_id, 1);
1834 if (fns == error_mark_node)
1835 return error_mark_node;
1837 /* Check for baselinks. */
1838 if (BASELINK_P (fns))
1839 fns = BASELINK_FUNCTIONS (fns);
1841 if (!is_overloaded_fn (fns))
1843 error ("%qD is not a function template", fns);
1844 return error_mark_node;
1847 /* Count the number of template headers specified for this
1850 for (b = current_binding_level;
1851 b->kind == sk_template_parms;
1855 for (; fns; fns = OVL_NEXT (fns))
1857 tree fn = OVL_CURRENT (fns);
1859 if (TREE_CODE (fn) == TEMPLATE_DECL)
1861 tree decl_arg_types;
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;
3241 PACK_EXPANSION_LOCAL_P (result) = at_function_scope_p ();
3246 /* Checks T for any "bare" parameter packs, which have not yet been
3247 expanded, and issues an error if any are found. This operation can
3248 only be done on full expressions or types (e.g., an expression
3249 statement, "if" condition, etc.), because we could have expressions like:
3251 foo(f(g(h(args)))...)
3253 where "args" is a parameter pack. check_for_bare_parameter_packs
3254 should not be called for the subexpressions args, h(args),
3255 g(h(args)), or f(g(h(args))), because we would produce erroneous
3258 Returns TRUE and emits an error if there were bare parameter packs,
3259 returns FALSE otherwise. */
3261 check_for_bare_parameter_packs (tree t)
3263 tree parameter_packs = NULL_TREE;
3264 struct find_parameter_pack_data ppd;
3266 if (!processing_template_decl || !t || t == error_mark_node)
3269 if (TREE_CODE (t) == TYPE_DECL)
3272 ppd.parameter_packs = ¶meter_packs;
3273 ppd.visited = pointer_set_create ();
3274 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
3275 pointer_set_destroy (ppd.visited);
3277 if (parameter_packs)
3279 error ("parameter packs not expanded with %<...%>:");
3280 while (parameter_packs)
3282 tree pack = TREE_VALUE (parameter_packs);
3283 tree name = NULL_TREE;
3285 if (TREE_CODE (pack) == TEMPLATE_TYPE_PARM
3286 || TREE_CODE (pack) == TEMPLATE_TEMPLATE_PARM)
3287 name = TYPE_NAME (pack);
3288 else if (TREE_CODE (pack) == TEMPLATE_PARM_INDEX)
3289 name = DECL_NAME (TEMPLATE_PARM_DECL (pack));
3291 name = DECL_NAME (pack);
3294 inform (input_location, " %qD", name);
3296 inform (input_location, " <anonymous>");
3298 parameter_packs = TREE_CHAIN (parameter_packs);
3307 /* Expand any parameter packs that occur in the template arguments in
3310 expand_template_argument_pack (tree args)
3312 tree result_args = NULL_TREE;
3313 int in_arg, out_arg = 0, nargs = args ? TREE_VEC_LENGTH (args) : 0;
3314 int num_result_args = -1;
3315 int non_default_args_count = -1;
3317 /* First, determine if we need to expand anything, and the number of
3318 slots we'll need. */
3319 for (in_arg = 0; in_arg < nargs; ++in_arg)
3321 tree arg = TREE_VEC_ELT (args, in_arg);
3322 if (arg == NULL_TREE)
3324 if (ARGUMENT_PACK_P (arg))
3326 int num_packed = TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg));
3327 if (num_result_args < 0)
3328 num_result_args = in_arg + num_packed;
3330 num_result_args += num_packed;
3334 if (num_result_args >= 0)
3339 /* If no expansion is necessary, we're done. */
3340 if (num_result_args < 0)
3343 /* Expand arguments. */
3344 result_args = make_tree_vec (num_result_args);
3345 if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (args))
3346 non_default_args_count =
3347 GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (args);
3348 for (in_arg = 0; in_arg < nargs; ++in_arg)
3350 tree arg = TREE_VEC_ELT (args, in_arg);
3351 if (ARGUMENT_PACK_P (arg))
3353 tree packed = ARGUMENT_PACK_ARGS (arg);
3354 int i, num_packed = TREE_VEC_LENGTH (packed);
3355 for (i = 0; i < num_packed; ++i, ++out_arg)
3356 TREE_VEC_ELT (result_args, out_arg) = TREE_VEC_ELT(packed, i);
3357 if (non_default_args_count > 0)
3358 non_default_args_count += num_packed;
3362 TREE_VEC_ELT (result_args, out_arg) = arg;
3366 if (non_default_args_count >= 0)
3367 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (result_args, non_default_args_count);
3371 /* Checks if DECL shadows a template parameter.
3373 [temp.local]: A template-parameter shall not be redeclared within its
3374 scope (including nested scopes).
3376 Emits an error and returns TRUE if the DECL shadows a parameter,
3377 returns FALSE otherwise. */
3380 check_template_shadow (tree decl)
3384 /* If we're not in a template, we can't possibly shadow a template
3386 if (!current_template_parms)
3389 /* Figure out what we're shadowing. */
3390 if (TREE_CODE (decl) == OVERLOAD)
3391 decl = OVL_CURRENT (decl);
3392 olddecl = innermost_non_namespace_value (DECL_NAME (decl));
3394 /* If there's no previous binding for this name, we're not shadowing
3395 anything, let alone a template parameter. */
3399 /* If we're not shadowing a template parameter, we're done. Note
3400 that OLDDECL might be an OVERLOAD (or perhaps even an
3401 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3403 if (!DECL_P (olddecl) || !DECL_TEMPLATE_PARM_P (olddecl))
3406 /* We check for decl != olddecl to avoid bogus errors for using a
3407 name inside a class. We check TPFI to avoid duplicate errors for
3408 inline member templates. */
3410 || TEMPLATE_PARMS_FOR_INLINE (current_template_parms))
3413 error ("declaration of %q+#D", decl);
3414 error (" shadows template parm %q+#D", olddecl);
3418 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3419 ORIG_LEVEL, DECL, and TYPE. NUM_SIBLINGS is the total number of
3420 template parameters. */
3423 build_template_parm_index (int index,
3430 tree t = make_node (TEMPLATE_PARM_INDEX);
3431 TEMPLATE_PARM_IDX (t) = index;
3432 TEMPLATE_PARM_LEVEL (t) = level;
3433 TEMPLATE_PARM_ORIG_LEVEL (t) = orig_level;
3434 TEMPLATE_PARM_NUM_SIBLINGS (t) = num_siblings;
3435 TEMPLATE_PARM_DECL (t) = decl;
3436 TREE_TYPE (t) = type;
3437 TREE_CONSTANT (t) = TREE_CONSTANT (decl);
3438 TREE_READONLY (t) = TREE_READONLY (decl);
3443 /* Find the canonical type parameter for the given template type
3444 parameter. Returns the canonical type parameter, which may be TYPE
3445 if no such parameter existed. */
3448 canonical_type_parameter (tree type)
3451 int idx = TEMPLATE_TYPE_IDX (type);
3452 if (!canonical_template_parms)
3453 canonical_template_parms = VEC_alloc (tree, gc, idx+1);
3455 while (VEC_length (tree, canonical_template_parms) <= (unsigned)idx)
3456 VEC_safe_push (tree, gc, canonical_template_parms, NULL_TREE);
3458 list = VEC_index (tree, canonical_template_parms, idx);
3459 while (list && !comptypes (type, TREE_VALUE (list), COMPARE_STRUCTURAL))
3460 list = TREE_CHAIN (list);
3463 return TREE_VALUE (list);
3466 VEC_replace(tree, canonical_template_parms, idx,
3467 tree_cons (NULL_TREE, type,
3468 VEC_index (tree, canonical_template_parms, idx)));
3473 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3474 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3475 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3476 new one is created. */
3479 reduce_template_parm_level (tree index, tree type, int levels, tree args,
3480 tsubst_flags_t complain)
3482 if (TEMPLATE_PARM_DESCENDANTS (index) == NULL_TREE
3483 || (TEMPLATE_PARM_LEVEL (TEMPLATE_PARM_DESCENDANTS (index))
3484 != TEMPLATE_PARM_LEVEL (index) - levels)
3485 || !same_type_p (type, TREE_TYPE (TEMPLATE_PARM_DESCENDANTS (index))))
3487 tree orig_decl = TEMPLATE_PARM_DECL (index);
3490 decl = build_decl (DECL_SOURCE_LOCATION (orig_decl),
3491 TREE_CODE (orig_decl), DECL_NAME (orig_decl), type);
3492 TREE_CONSTANT (decl) = TREE_CONSTANT (orig_decl);
3493 TREE_READONLY (decl) = TREE_READONLY (orig_decl);
3494 DECL_ARTIFICIAL (decl) = 1;
3495 SET_DECL_TEMPLATE_PARM_P (decl);
3497 t = build_template_parm_index (TEMPLATE_PARM_IDX (index),
3498 TEMPLATE_PARM_LEVEL (index) - levels,
3499 TEMPLATE_PARM_ORIG_LEVEL (index),
3500 TEMPLATE_PARM_NUM_SIBLINGS (index),
3502 TEMPLATE_PARM_DESCENDANTS (index) = t;
3503 TEMPLATE_PARM_PARAMETER_PACK (t)
3504 = TEMPLATE_PARM_PARAMETER_PACK (index);
3506 /* Template template parameters need this. */
3507 if (TREE_CODE (decl) == TEMPLATE_DECL)
3508 DECL_TEMPLATE_PARMS (decl) = tsubst_template_parms
3509 (DECL_TEMPLATE_PARMS (TEMPLATE_PARM_DECL (index)),
3513 return TEMPLATE_PARM_DESCENDANTS (index);
3516 /* Process information from new template parameter PARM and append it
3517 to the LIST being built. This new parameter is a non-type
3518 parameter iff IS_NON_TYPE is true. This new parameter is a
3519 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3520 is in PARM_LOC. NUM_TEMPLATE_PARMS is the size of the template
3521 parameter list PARM belongs to. This is used used to create a
3522 proper canonical type for the type of PARM that is to be created,
3523 iff PARM is a type. If the size is not known, this parameter shall
3527 process_template_parm (tree list, location_t parm_loc, tree parm,
3528 bool is_non_type, bool is_parameter_pack,
3529 unsigned num_template_parms)
3536 gcc_assert (TREE_CODE (parm) == TREE_LIST);
3537 defval = TREE_PURPOSE (parm);
3541 tree p = tree_last (list);
3543 if (p && TREE_VALUE (p) != error_mark_node)
3546 if (TREE_CODE (p) == TYPE_DECL || TREE_CODE (p) == TEMPLATE_DECL)
3547 idx = TEMPLATE_TYPE_IDX (TREE_TYPE (p));
3549 idx = TEMPLATE_PARM_IDX (DECL_INITIAL (p));
3559 parm = TREE_VALUE (parm);
3561 SET_DECL_TEMPLATE_PARM_P (parm);
3563 if (TREE_TYPE (parm) == error_mark_node)
3565 err_parm_list = build_tree_list (defval, parm);
3566 TREE_VALUE (err_parm_list) = error_mark_node;
3567 return chainon (list, err_parm_list);
3573 The top-level cv-qualifiers on the template-parameter are
3574 ignored when determining its type. */
3575 TREE_TYPE (parm) = TYPE_MAIN_VARIANT (TREE_TYPE (parm));
3576 if (invalid_nontype_parm_type_p (TREE_TYPE (parm), 1))
3578 err_parm_list = build_tree_list (defval, parm);
3579 TREE_VALUE (err_parm_list) = error_mark_node;
3580 return chainon (list, err_parm_list);
3583 if (uses_parameter_packs (TREE_TYPE (parm)) && !is_parameter_pack)
3585 /* This template parameter is not a parameter pack, but it
3586 should be. Complain about "bare" parameter packs. */
3587 check_for_bare_parameter_packs (TREE_TYPE (parm));
3589 /* Recover by calling this a parameter pack. */
3590 is_parameter_pack = true;
3594 /* A template parameter is not modifiable. */
3595 TREE_CONSTANT (parm) = 1;
3596 TREE_READONLY (parm) = 1;
3597 decl = build_decl (parm_loc,
3598 CONST_DECL, DECL_NAME (parm), TREE_TYPE (parm));
3599 TREE_CONSTANT (decl) = 1;
3600 TREE_READONLY (decl) = 1;
3601 DECL_INITIAL (parm) = DECL_INITIAL (decl)
3602 = build_template_parm_index (idx, processing_template_decl,
3603 processing_template_decl,
3605 decl, TREE_TYPE (parm));
3607 TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))
3608 = is_parameter_pack;
3613 parm = TREE_VALUE (TREE_VALUE (parm));
3615 if (parm && TREE_CODE (parm) == TEMPLATE_DECL)
3617 t = cxx_make_type (TEMPLATE_TEMPLATE_PARM);
3618 /* This is for distinguishing between real templates and template
3619 template parameters */
3620 TREE_TYPE (parm) = t;
3621 TREE_TYPE (DECL_TEMPLATE_RESULT (parm)) = t;
3626 t = cxx_make_type (TEMPLATE_TYPE_PARM);
3627 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3628 decl = build_decl (parm_loc,
3629 TYPE_DECL, parm, t);
3632 TYPE_NAME (t) = decl;
3633 TYPE_STUB_DECL (t) = decl;
3635 TEMPLATE_TYPE_PARM_INDEX (t)
3636 = build_template_parm_index (idx, processing_template_decl,
3637 processing_template_decl,
3639 decl, TREE_TYPE (parm));
3640 TEMPLATE_TYPE_PARAMETER_PACK (t) = is_parameter_pack;
3641 TYPE_CANONICAL (t) = canonical_type_parameter (t);
3643 DECL_ARTIFICIAL (decl) = 1;
3644 SET_DECL_TEMPLATE_PARM_P (decl);
3646 parm = build_tree_list (defval, parm);
3647 return chainon (list, parm);
3650 /* The end of a template parameter list has been reached. Process the
3651 tree list into a parameter vector, converting each parameter into a more
3652 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3656 end_template_parm_list (tree parms)
3660 tree saved_parmlist = make_tree_vec (list_length (parms));
3662 current_template_parms
3663 = tree_cons (size_int (processing_template_decl),
3664 saved_parmlist, current_template_parms);
3666 for (parm = parms, nparms = 0; parm; parm = next, nparms++)
3668 next = TREE_CHAIN (parm);
3669 TREE_VEC_ELT (saved_parmlist, nparms) = parm;
3670 TREE_CHAIN (parm) = NULL_TREE;
3673 --processing_template_parmlist;
3675 return saved_parmlist;
3678 /* Create a new type almost identical to TYPE but which has the
3679 following differences:
3681 1/ T has a new TEMPLATE_PARM_INDEX that carries the new number of
3682 template sibling parameters of T.
3684 2/ T has a new canonical type that matches the new number
3687 3/ From now on, T is going to be what lookups referring to the
3688 name of TYPE will return. No lookup should return TYPE anymore.
3690 NUM_PARMS is the new number of sibling parms TYPE belongs to.
3692 This is a subroutine of fixup_template_parms. */
3695 fixup_template_type_parm_type (tree type, int num_parms)
3697 tree orig_idx = TEMPLATE_TYPE_PARM_INDEX (type), idx;
3699 /* This is the decl which name is inserted into the symbol table for
3700 the template parm type. So whenever we lookup the type name, this
3701 is the DECL we get. */
3704 /* Do not fix up the type twice. */
3705 if (orig_idx && TEMPLATE_PARM_NUM_SIBLINGS (orig_idx) != 0)
3708 t = copy_type (type);
3709 decl = TYPE_NAME (t);
3711 TYPE_MAIN_VARIANT (t) = t;
3712 TYPE_NEXT_VARIANT (t)= NULL_TREE;
3713 TYPE_POINTER_TO (t) = 0;
3714 TYPE_REFERENCE_TO (t) = 0;
3716 idx = build_template_parm_index (TEMPLATE_PARM_IDX (orig_idx),
3717 TEMPLATE_PARM_LEVEL (orig_idx),
3718 TEMPLATE_PARM_ORIG_LEVEL (orig_idx),
3721 TEMPLATE_PARM_DESCENDANTS (idx) = TEMPLATE_PARM_DESCENDANTS (orig_idx);
3722 TEMPLATE_PARM_PARAMETER_PACK (idx) = TEMPLATE_PARM_PARAMETER_PACK (orig_idx);
3723 TEMPLATE_TYPE_PARM_INDEX (t) = idx;
3725 TYPE_STUB_DECL (t) = decl;
3726 TEMPLATE_TYPE_DECL (t) = decl;
3727 if (TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM)
3728 TREE_TYPE (DECL_TEMPLATE_RESULT (decl)) = t;
3730 /* Update the type associated to the type name stored in the symbol
3731 table. Now, whenever the type name is looked up, the resulting
3732 type is properly fixed up. */
3733 TREE_TYPE (decl) = t;
3735 TYPE_CANONICAL (t) = canonical_type_parameter (t);
3740 /* Create and return a new TEMPLATE_PARM_INDEX that is almost
3741 identical to I, but that is fixed up as to:
3743 1/ carry the number of sibling parms (NUM_PARMS) of the template
3744 parm represented by I.
3746 2/ replace all references to template parm types declared before I
3747 (in the same template parm list as I) by references to template
3748 parm types contained in ARGS. ARGS should contain the list of
3749 template parms that have been fixed up so far, in a form suitable
3750 to be passed to tsubst.
3752 This is a subroutine of fixup_template_parms. */
3755 fixup_template_parm_index (tree i, tree args, int num_parms)
3757 tree index, decl, type;
3760 || TREE_CODE (i) != TEMPLATE_PARM_INDEX
3761 /* Do not fix up the index twice. */
3762 || (TEMPLATE_PARM_NUM_SIBLINGS (i) != 0))
3765 decl = TEMPLATE_PARM_DECL (i);
3766 type = TREE_TYPE (decl);
3768 index = build_template_parm_index (TEMPLATE_PARM_IDX (i),
3769 TEMPLATE_PARM_LEVEL (i),
3770 TEMPLATE_PARM_ORIG_LEVEL (i),
3774 TEMPLATE_PARM_DESCENDANTS (index) = TEMPLATE_PARM_DESCENDANTS (i);
3775 TEMPLATE_PARM_PARAMETER_PACK (index) = TEMPLATE_PARM_PARAMETER_PACK (i);
3777 type = tsubst (type, args, tf_none, NULL_TREE);
3779 TREE_TYPE (decl) = type;
3780 TREE_TYPE (index) = type;
3786 This is a subroutine of fixup_template_parms.
3788 It computes the canonical type of the type of the template
3789 parameter PARM_DESC and update all references to that type so that
3790 they use the newly computed canonical type. No access check is
3791 performed during the fixup. PARM_DESC is a TREE_LIST which
3792 TREE_VALUE is the template parameter and its TREE_PURPOSE is the
3793 default argument of the template parm if any. IDX is the index of
3794 the template parameter, starting at 0. NUM_PARMS is the number of
3795 template parameters in the set PARM_DESC belongs to. ARGLIST is a
3796 TREE_VEC containing the full set of template parameters in a form
3797 suitable to be passed to substs functions as their ARGS
3798 argument. This is what current_template_args returns for a given
3799 template. The innermost vector of args in ARGLIST is the set of
3800 template parms that have been fixed up so far. This function adds
3801 the fixed up parameter into that vector. */
3804 fixup_template_parm (tree parm_desc,
3809 tree parm = TREE_VALUE (parm_desc);
3810 tree fixedup_args = INNERMOST_TEMPLATE_ARGS (arglist);
3812 push_deferring_access_checks (dk_no_check);
3814 if (TREE_CODE (parm) == TYPE_DECL)
3816 /* PARM is a template type parameter. Fix up its type, add
3817 the fixed-up template parm to the vector of fixed-up
3818 template parms so far, and substitute the fixed-up
3819 template parms into the default argument of this
3822 fixup_template_type_parm_type (TREE_TYPE (parm), num_parms);
3823 TREE_TYPE (parm) = t;
3825 TREE_VEC_ELT (fixedup_args, idx) = template_parm_to_arg (parm_desc);
3827 else if (TREE_CODE (parm) == TEMPLATE_DECL)
3829 /* PARM is a template template parameter. This is going to
3831 tree tparms, targs, innermost_args, t;
3834 /* First, fix up the parms of the template template parm
3835 because the parms are involved in defining the new canonical
3836 type of the template template parm. */
3838 /* So we need to substitute the template parm types that have
3839 been fixed up so far into the template parms of this template
3840 template parm. E.g, consider this:
3842 template<class T, template<T u> class TT> class S;
3844 In this case we want to substitute T into the
3845 template parameters of TT.
3847 So let's walk the template parms of PARM here, and
3848 tsubst ARGLIST into into each of the template
3851 /* For this substitution we need to build the full set of
3852 template parameters and use that as arguments for the
3853 tsubsting function. */
3854 tparms = INNERMOST_TEMPLATE_PARMS (DECL_TEMPLATE_PARMS (parm));
3856 /* This will contain the innermost parms of PARM into which
3857 we have substituted so far. */
3858 innermost_args = make_tree_vec (TREE_VEC_LENGTH (tparms));
3859 targs = add_to_template_args (arglist, innermost_args);
3860 for (j = 0; j < TREE_VEC_LENGTH (tparms); ++j)
3864 parameter = TREE_VEC_ELT (tparms, j);
3866 /* INNERMOST_ARGS needs to have at least the same number
3867 of elements as the index PARAMETER, ortherwise
3868 tsubsting into PARAMETER will result in partially
3869 instantiating it, reducing its tempate parm
3870 level. Let's tactically fill INNERMOST_ARGS for that
3872 TREE_VEC_ELT (innermost_args, j) =
3873 template_parm_to_arg (parameter);
3875 fixup_template_parm (parameter, j,
3876 TREE_VEC_LENGTH (tparms),
3880 /* Now fix up the type of the template template parm. */
3882 t = fixup_template_type_parm_type (TREE_TYPE (parm), num_parms);
3883 TREE_TYPE (parm) = t;
3885 TREE_VEC_ELT (fixedup_args, idx) =
3886 template_parm_to_arg (parm_desc);
3888 else if (TREE_CODE (parm) == PARM_DECL)
3890 /* PARM is a non-type template parameter. We need to:
3892 * Fix up its TEMPLATE_PARM_INDEX to make it carry the
3893 proper number of sibling parameters.
3895 * Make lookups of the template parameter return a reference
3896 to the fixed-up index. No lookup should return references
3897 to the former index anymore.
3899 * Substitute the template parms that got fixed up so far
3901 * into the type of PARM. */
3903 tree index = DECL_INITIAL (parm);
3905 /* PUSHED_DECL is the decl added to the symbol table with
3906 the name of the parameter. E,g:
3908 template<class T, T u> //#0
3909 auto my_function(T t) -> decltype(u); //#1
3911 Here, when looking up u at //#1, we get the decl of u
3912 resulting from the declaration in #0. This is what
3913 PUSHED_DECL is. We need to replace the reference to the
3914 old TEMPLATE_PARM_INDEX carried by PUSHED_DECL by the
3915 fixed-up TEMPLATE_PARM_INDEX. */
3916 tree pushed_decl = TEMPLATE_PARM_DECL (index);
3918 /* Let's fix up the TEMPLATE_PARM_INDEX then. Note that we must
3919 fixup the type of PUSHED_DECL as well and luckily
3920 fixup_template_parm_index does it for us too. */
3921 tree fixed_up_index =
3922 fixup_template_parm_index (index, arglist, num_parms);
3924 DECL_INITIAL (pushed_decl) = DECL_INITIAL (parm) = fixed_up_index;
3926 /* Add this fixed up PARM to the template parms we've fixed
3927 up so far and use that to substitute the fixed-up
3928 template parms into the type of PARM. */
3929 TREE_VEC_ELT (fixedup_args, idx) =
3930 template_parm_to_arg (parm_desc);
3931 TREE_TYPE (parm) = tsubst (TREE_TYPE (parm), arglist,
3932 tf_none, NULL_TREE);
3935 TREE_PURPOSE (parm_desc) =
3936 tsubst_template_arg (TREE_PURPOSE (parm_desc),
3937 arglist, tf_none, parm);
3939 pop_deferring_access_checks ();
3942 /* Walk the current template parms and properly compute the canonical
3943 types of the dependent types created during
3944 cp_parser_template_parameter_list. */
3947 fixup_template_parms (void)
3954 parameter_vec = INNERMOST_TEMPLATE_PARMS (current_template_parms);
3955 if (parameter_vec == NULL_TREE)
3958 num_parms = TREE_VEC_LENGTH (parameter_vec);
3960 /* This vector contains the current innermost template parms that
3961 have been fixed up so far. The form of FIXEDUP_ARGS is suitable
3962 to be passed to tsubst* functions as their ARGS argument. */
3963 fixedup_args = make_tree_vec (num_parms);
3965 /* This vector contains the full set of template parms in a form
3966 suitable to be passed to substs functions as their ARGS
3968 arglist = current_template_args ();
3969 arglist = add_outermost_template_args (arglist, fixedup_args);
3971 /* Let's do the proper fixup now. */
3972 for (i = 0; i < num_parms; ++i)
3973 fixup_template_parm (TREE_VEC_ELT (parameter_vec, i),
3974 i, num_parms, arglist);
3977 /* end_template_decl is called after a template declaration is seen. */
3980 end_template_decl (void)
3982 reset_specialization ();
3984 if (! processing_template_decl)
3987 /* This matches the pushlevel in begin_template_parm_list. */
3990 --processing_template_decl;
3991 current_template_parms = TREE_CHAIN (current_template_parms);
3994 /* Takes a TREE_LIST representing a template parameter and convert it
3995 into an argument suitable to be passed to the type substitution
3996 functions. Note that If the TREE_LIST contains an error_mark
3997 node, the returned argument is error_mark_node. */
4000 template_parm_to_arg (tree t)
4004 || TREE_CODE (t) != TREE_LIST)
4007 if (error_operand_p (TREE_VALUE (t)))
4008 return error_mark_node;
4012 if (TREE_CODE (t) == TYPE_DECL
4013 || TREE_CODE (t) == TEMPLATE_DECL)
4017 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
4019 /* Turn this argument into a TYPE_ARGUMENT_PACK
4020 with a single element, which expands T. */
4021 tree vec = make_tree_vec (1);
4022 #ifdef ENABLE_CHECKING
4023 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
4024 (vec, TREE_VEC_LENGTH (vec));
4026 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
4028 t = cxx_make_type (TYPE_ARGUMENT_PACK);
4029 SET_ARGUMENT_PACK_ARGS (t, vec);
4034 t = DECL_INITIAL (t);
4036 if (TEMPLATE_PARM_PARAMETER_PACK (t))
4038 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
4039 with a single element, which expands T. */
4040 tree vec = make_tree_vec (1);
4041 tree type = TREE_TYPE (TEMPLATE_PARM_DECL (t));
4042 #ifdef ENABLE_CHECKING
4043 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
4044 (vec, TREE_VEC_LENGTH (vec));
4046 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
4048 t = make_node (NONTYPE_ARGUMENT_PACK);
4049 SET_ARGUMENT_PACK_ARGS (t, vec);
4050 TREE_TYPE (t) = type;
4056 /* This function returns TRUE if PARM_PACK is a template parameter
4057 pack and if ARG_PACK is what template_parm_to_arg returned when
4058 passed PARM_PACK. */
4061 arg_from_parm_pack_p (tree arg_pack, tree parm_pack)
4063 /* For clarity in the comments below let's use the representation
4064 argument_pack<elements>' to denote an argument pack and its
4067 In the 'if' block below, we want to detect cases where
4068 ARG_PACK is argument_pack<PARM_PACK...>. I.e, we want to
4069 check if ARG_PACK is an argument pack which sole element is
4070 the expansion of PARM_PACK. That argument pack is typically
4071 created by template_parm_to_arg when passed a parameter
4075 && TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack)) == 1
4076 && PACK_EXPANSION_P (TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0)))
4078 tree expansion = TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0);
4079 tree pattern = PACK_EXPANSION_PATTERN (expansion);
4080 /* So we have an argument_pack<P...>. We want to test if P
4081 is actually PARM_PACK. We will not use cp_tree_equal to
4082 test P and PARM_PACK because during type fixup (by
4083 fixup_template_parm) P can be a pre-fixup version of a
4084 type and PARM_PACK be its post-fixup version.
4085 cp_tree_equal would consider them as different even
4086 though we would want to consider them compatible for our
4087 precise purpose here.
4089 Thus we are going to consider that P and PARM_PACK are
4090 compatible if they have the same DECL. */
4091 if ((/* If ARG_PACK is a type parameter pack named by the
4092 same DECL as parm_pack ... */
4094 && TYPE_P (parm_pack)
4095 && TYPE_NAME (pattern) == TYPE_NAME (parm_pack))
4096 /* ... or if PARM_PACK is a non-type parameter named by the
4097 same DECL as ARG_PACK. Note that PARM_PACK being a
4098 non-type parameter means it's either a PARM_DECL or a
4099 TEMPLATE_PARM_INDEX. */
4100 || (TREE_CODE (pattern) == TEMPLATE_PARM_INDEX
4101 && ((TREE_CODE (parm_pack) == PARM_DECL
4102 && (TEMPLATE_PARM_DECL (pattern)
4103 == TEMPLATE_PARM_DECL (DECL_INITIAL (parm_pack))))
4104 || (TREE_CODE (parm_pack) == TEMPLATE_PARM_INDEX
4105 && (TEMPLATE_PARM_DECL (pattern)
4106 == TEMPLATE_PARM_DECL (parm_pack))))))
4107 && template_parameter_pack_p (pattern))
4113 /* Within the declaration of a template, return all levels of template
4114 parameters that apply. The template parameters are represented as
4115 a TREE_VEC, in the form documented in cp-tree.h for template
4119 current_template_args (void)
4122 tree args = NULL_TREE;
4123 int length = TMPL_PARMS_DEPTH (current_template_parms);
4126 /* If there is only one level of template parameters, we do not
4127 create a TREE_VEC of TREE_VECs. Instead, we return a single
4128 TREE_VEC containing the arguments. */
4130 args = make_tree_vec (length);
4132 for (header = current_template_parms; header; header = TREE_CHAIN (header))
4134 tree a = copy_node (TREE_VALUE (header));
4137 TREE_TYPE (a) = NULL_TREE;
4138 for (i = TREE_VEC_LENGTH (a) - 1; i >= 0; --i)
4139 TREE_VEC_ELT (a, i) = template_parm_to_arg (TREE_VEC_ELT (a, i));
4141 #ifdef ENABLE_CHECKING
4142 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (a, TREE_VEC_LENGTH (a));
4146 TREE_VEC_ELT (args, --l) = a;
4151 if (length > 1 && TREE_VEC_ELT (args, 0) == NULL_TREE)
4152 /* This can happen for template parms of a template template
4155 template<template<class T, class U> class TT> struct S;
4157 Consider the level of the parms of TT; T and U both have
4158 level 2; TT has no template parm of level 1. So in this case
4159 the first element of full_template_args is NULL_TREE. If we
4160 leave it like this TMPL_ARG_DEPTH on args returns 1 instead
4161 of 2. This will make tsubst wrongly consider that T and U
4162 have level 1. Instead, let's create a dummy vector as the
4163 first element of full_template_args so that TMPL_ARG_DEPTH
4164 returns the correct depth for args. */
4165 TREE_VEC_ELT (args, 0) = make_tree_vec (1);
4169 /* Update the declared TYPE by doing any lookups which were thought to be
4170 dependent, but are not now that we know the SCOPE of the declarator. */
4173 maybe_update_decl_type (tree orig_type, tree scope)
4175 tree type = orig_type;
4177 if (type == NULL_TREE)
4180 if (TREE_CODE (orig_type) == TYPE_DECL)
4181 type = TREE_TYPE (type);
4183 if (scope && TYPE_P (scope) && dependent_type_p (scope)
4184 && dependent_type_p (type)
4185 /* Don't bother building up the args in this case. */
4186 && TREE_CODE (type) != TEMPLATE_TYPE_PARM)
4188 /* tsubst in the args corresponding to the template parameters,
4189 including auto if present. Most things will be unchanged, but
4190 make_typename_type and tsubst_qualified_id will resolve
4191 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4192 tree args = current_template_args ();
4193 tree auto_node = type_uses_auto (type);
4197 tree auto_vec = make_tree_vec (1);
4198 TREE_VEC_ELT (auto_vec, 0) = auto_node;
4199 args = add_to_template_args (args, auto_vec);
4201 pushed = push_scope (scope);
4202 type = tsubst (type, args, tf_warning_or_error, NULL_TREE);
4207 if (type == error_mark_node)
4210 if (TREE_CODE (orig_type) == TYPE_DECL)
4212 if (same_type_p (type, TREE_TYPE (orig_type)))
4215 type = TYPE_NAME (type);
4220 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4221 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
4222 a member template. Used by push_template_decl below. */
4225 build_template_decl (tree decl, tree parms, bool member_template_p)
4227 tree tmpl = build_lang_decl (TEMPLATE_DECL, DECL_NAME (decl), NULL_TREE);
4228 DECL_TEMPLATE_PARMS (tmpl) = parms;
4229 DECL_CONTEXT (tmpl) = DECL_CONTEXT (decl);
4230 DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl);
4231 DECL_MEMBER_TEMPLATE_P (tmpl) = member_template_p;
4236 struct template_parm_data
4238 /* The level of the template parameters we are currently
4242 /* The index of the specialization argument we are currently
4246 /* An array whose size is the number of template parameters. The
4247 elements are nonzero if the parameter has been used in any one
4248 of the arguments processed so far. */
4251 /* An array whose size is the number of template arguments. The
4252 elements are nonzero if the argument makes use of template
4253 parameters of this level. */
4254 int* arg_uses_template_parms;
4257 /* Subroutine of push_template_decl used to see if each template
4258 parameter in a partial specialization is used in the explicit
4259 argument list. If T is of the LEVEL given in DATA (which is
4260 treated as a template_parm_data*), then DATA->PARMS is marked
4264 mark_template_parm (tree t, void* data)
4268 struct template_parm_data* tpd = (struct template_parm_data*) data;
4270 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
4272 level = TEMPLATE_PARM_LEVEL (t);
4273 idx = TEMPLATE_PARM_IDX (t);
4277 level = TEMPLATE_TYPE_LEVEL (t);
4278 idx = TEMPLATE_TYPE_IDX (t);
4281 if (level == tpd->level)
4283 tpd->parms[idx] = 1;
4284 tpd->arg_uses_template_parms[tpd->current_arg] = 1;
4287 /* Return zero so that for_each_template_parm will continue the
4288 traversal of the tree; we want to mark *every* template parm. */
4292 /* Process the partial specialization DECL. */
4295 process_partial_specialization (tree decl)
4297 tree type = TREE_TYPE (decl);
4298 tree maintmpl = CLASSTYPE_TI_TEMPLATE (type);
4299 tree specargs = CLASSTYPE_TI_ARGS (type);
4300 tree inner_args = INNERMOST_TEMPLATE_ARGS (specargs);
4301 tree main_inner_parms = DECL_INNERMOST_TEMPLATE_PARMS (maintmpl);
4304 int nargs = TREE_VEC_LENGTH (inner_args);
4307 bool did_error_intro = false;
4308 struct template_parm_data tpd;
4309 struct template_parm_data tpd2;
4311 gcc_assert (current_template_parms);
4313 inner_parms = INNERMOST_TEMPLATE_PARMS (current_template_parms);
4314 ntparms = TREE_VEC_LENGTH (inner_parms);
4316 /* We check that each of the template parameters given in the
4317 partial specialization is used in the argument list to the
4318 specialization. For example:
4320 template <class T> struct S;
4321 template <class T> struct S<T*>;
4323 The second declaration is OK because `T*' uses the template
4324 parameter T, whereas
4326 template <class T> struct S<int>;
4328 is no good. Even trickier is:
4339 The S2<T> declaration is actually invalid; it is a
4340 full-specialization. Of course,
4343 struct S2<T (*)(U)>;
4345 or some such would have been OK. */
4346 tpd.level = TMPL_PARMS_DEPTH (current_template_parms);
4347 tpd.parms = XALLOCAVEC (int, ntparms);
4348 memset (tpd.parms, 0, sizeof (int) * ntparms);
4350 tpd.arg_uses_template_parms = XALLOCAVEC (int, nargs);
4351 memset (tpd.arg_uses_template_parms, 0, sizeof (int) * nargs);
4352 for (i = 0; i < nargs; ++i)
4354 tpd.current_arg = i;
4355 for_each_template_parm (TREE_VEC_ELT (inner_args, i),
4356 &mark_template_parm,
4359 /*include_nondeduced_p=*/false);
4361 for (i = 0; i < ntparms; ++i)
4362 if (tpd.parms[i] == 0)
4364 /* One of the template parms was not used in the
4366 if (!did_error_intro)
4368 error ("template parameters not used in partial specialization:");
4369 did_error_intro = true;
4372 error (" %qD", TREE_VALUE (TREE_VEC_ELT (inner_parms, i)));
4375 if (did_error_intro)
4376 return error_mark_node;
4378 /* [temp.class.spec]
4380 The argument list of the specialization shall not be identical to
4381 the implicit argument list of the primary template. */
4382 if (comp_template_args
4384 INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE
4386 error ("partial specialization %qT does not specialize any template arguments", type);
4388 /* [temp.class.spec]
4390 A partially specialized non-type argument expression shall not
4391 involve template parameters of the partial specialization except
4392 when the argument expression is a simple identifier.
4394 The type of a template parameter corresponding to a specialized
4395 non-type argument shall not be dependent on a parameter of the
4398 Also, we verify that pack expansions only occur at the
4399 end of the argument list. */
4400 gcc_assert (nargs == DECL_NTPARMS (maintmpl));
4402 for (i = 0; i < nargs; ++i)
4404 tree parm = TREE_VALUE (TREE_VEC_ELT (main_inner_parms, i));
4405 tree arg = TREE_VEC_ELT (inner_args, i);
4406 tree packed_args = NULL_TREE;
4409 if (ARGUMENT_PACK_P (arg))
4411 /* Extract the arguments from the argument pack. We'll be
4412 iterating over these in the following loop. */
4413 packed_args = ARGUMENT_PACK_ARGS (arg);
4414 len = TREE_VEC_LENGTH (packed_args);
4417 for (j = 0; j < len; j++)
4420 /* Get the Jth argument in the parameter pack. */
4421 arg = TREE_VEC_ELT (packed_args, j);
4423 if (PACK_EXPANSION_P (arg))
4425 /* Pack expansions must come at the end of the
4427 if ((packed_args && j < len - 1)
4428 || (!packed_args && i < nargs - 1))
4430 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
4431 error ("parameter pack argument %qE must be at the "
4432 "end of the template argument list", arg);
4434 error ("parameter pack argument %qT must be at the "
4435 "end of the template argument list", arg);
4439 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
4440 /* We only care about the pattern. */
4441 arg = PACK_EXPANSION_PATTERN (arg);
4443 if (/* These first two lines are the `non-type' bit. */
4445 && TREE_CODE (arg) != TEMPLATE_DECL
4446 /* This next line is the `argument expression is not just a
4447 simple identifier' condition and also the `specialized
4448 non-type argument' bit. */
4449 && TREE_CODE (arg) != TEMPLATE_PARM_INDEX)
4451 if ((!packed_args && tpd.arg_uses_template_parms[i])
4452 || (packed_args && uses_template_parms (arg)))
4453 error ("template argument %qE involves template parameter(s)",
4457 /* Look at the corresponding template parameter,
4458 marking which template parameters its type depends
4460 tree type = TREE_TYPE (parm);
4464 /* We haven't yet initialized TPD2. Do so now. */
4465 tpd2.arg_uses_template_parms = XALLOCAVEC (int, nargs);
4466 /* The number of parameters here is the number in the
4467 main template, which, as checked in the assertion
4469 tpd2.parms = XALLOCAVEC (int, nargs);
4471 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (maintmpl));
4474 /* Mark the template parameters. But this time, we're
4475 looking for the template parameters of the main
4476 template, not in the specialization. */
4477 tpd2.current_arg = i;
4478 tpd2.arg_uses_template_parms[i] = 0;
4479 memset (tpd2.parms, 0, sizeof (int) * nargs);
4480 for_each_template_parm (type,
4481 &mark_template_parm,
4484 /*include_nondeduced_p=*/false);
4486 if (tpd2.arg_uses_template_parms [i])
4488 /* The type depended on some template parameters.
4489 If they are fully specialized in the
4490 specialization, that's OK. */
4493 for (j = 0; j < nargs; ++j)
4494 if (tpd2.parms[j] != 0
4495 && tpd.arg_uses_template_parms [j])
4498 error_n (input_location, count,
4499 "type %qT of template argument %qE depends "
4500 "on a template parameter",
4501 "type %qT of template argument %qE depends "
4502 "on template parameters",
4511 /* We should only get here once. */
4512 gcc_assert (!COMPLETE_TYPE_P (type));
4514 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)
4515 = tree_cons (specargs, inner_parms,
4516 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl));
4517 TREE_TYPE (DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)) = type;
4519 for (inst = DECL_TEMPLATE_INSTANTIATIONS (maintmpl); inst;
4520 inst = TREE_CHAIN (inst))
4522 tree inst_type = TREE_VALUE (inst);
4523 if (COMPLETE_TYPE_P (inst_type)
4524 && CLASSTYPE_IMPLICIT_INSTANTIATION (inst_type))
4526 tree spec = most_specialized_class (inst_type, maintmpl, tf_none);
4527 if (spec && TREE_TYPE (spec) == type)
4528 permerror (input_location,
4529 "partial specialization of %qT after instantiation "
4530 "of %qT", type, inst_type);
4537 /* Check that a template declaration's use of default arguments and
4538 parameter packs is not invalid. Here, PARMS are the template
4539 parameters. IS_PRIMARY is nonzero if DECL is the thing declared by
4540 a primary template. IS_PARTIAL is nonzero if DECL is a partial
4544 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4545 declaration (but not a definition); 1 indicates a declaration, 2
4546 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4547 emitted for extraneous default arguments.
4549 Returns TRUE if there were no errors found, FALSE otherwise. */
4552 check_default_tmpl_args (tree decl, tree parms, int is_primary,
4553 int is_partial, int is_friend_decl)
4556 int last_level_to_check;
4558 bool no_errors = true;
4562 A default template-argument shall not be specified in a
4563 function template declaration or a function template definition, nor
4564 in the template-parameter-list of the definition of a member of a
4567 if (TREE_CODE (CP_DECL_CONTEXT (decl)) == FUNCTION_DECL)
4568 /* You can't have a function template declaration in a local
4569 scope, nor you can you define a member of a class template in a
4573 if (current_class_type
4574 && !TYPE_BEING_DEFINED (current_class_type)
4575 && DECL_LANG_SPECIFIC (decl)
4576 && DECL_DECLARES_FUNCTION_P (decl)
4577 /* If this is either a friend defined in the scope of the class
4578 or a member function. */
4579 && (DECL_FUNCTION_MEMBER_P (decl)
4580 ? same_type_p (DECL_CONTEXT (decl), current_class_type)
4581 : DECL_FRIEND_CONTEXT (decl)
4582 ? same_type_p (DECL_FRIEND_CONTEXT (decl), current_class_type)
4584 /* And, if it was a member function, it really was defined in
4585 the scope of the class. */
4586 && (!DECL_FUNCTION_MEMBER_P (decl)
4587 || DECL_INITIALIZED_IN_CLASS_P (decl)))
4588 /* We already checked these parameters when the template was
4589 declared, so there's no need to do it again now. This function
4590 was defined in class scope, but we're processing it's body now
4591 that the class is complete. */
4594 /* Core issue 226 (C++0x only): the following only applies to class
4596 if ((cxx_dialect == cxx98) || TREE_CODE (decl) != FUNCTION_DECL)
4600 If a template-parameter has a default template-argument, all
4601 subsequent template-parameters shall have a default
4602 template-argument supplied. */
4603 for (parm_level = parms; parm_level; parm_level = TREE_CHAIN (parm_level))
4605 tree inner_parms = TREE_VALUE (parm_level);
4606 int ntparms = TREE_VEC_LENGTH (inner_parms);
4607 int seen_def_arg_p = 0;
4610 for (i = 0; i < ntparms; ++i)
4612 tree parm = TREE_VEC_ELT (inner_parms, i);
4614 if (parm == error_mark_node)
4617 if (TREE_PURPOSE (parm))
4619 else if (seen_def_arg_p
4620 && !template_parameter_pack_p (TREE_VALUE (parm)))
4622 error ("no default argument for %qD", TREE_VALUE (parm));
4623 /* For better subsequent error-recovery, we indicate that
4624 there should have been a default argument. */
4625 TREE_PURPOSE (parm) = error_mark_node;
4631 /* Don't complain about an enclosing partial
4633 && parm_level == parms
4634 && TREE_CODE (decl) == TYPE_DECL
4636 && template_parameter_pack_p (TREE_VALUE (parm)))
4638 /* A primary class template can only have one
4639 parameter pack, at the end of the template
4642 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL)
4643 error ("parameter pack %qE must be at the end of the"
4644 " template parameter list", TREE_VALUE (parm));
4646 error ("parameter pack %qT must be at the end of the"
4647 " template parameter list",
4648 TREE_TYPE (TREE_VALUE (parm)));
4650 TREE_VALUE (TREE_VEC_ELT (inner_parms, i))
4658 if (((cxx_dialect == cxx98) && TREE_CODE (decl) != TYPE_DECL)
4662 /* For an ordinary class template, default template arguments are
4663 allowed at the innermost level, e.g.:
4664 template <class T = int>
4666 but, in a partial specialization, they're not allowed even
4667 there, as we have in [temp.class.spec]:
4669 The template parameter list of a specialization shall not
4670 contain default template argument values.
4672 So, for a partial specialization, or for a function template
4673 (in C++98/C++03), we look at all of them. */
4676 /* But, for a primary class template that is not a partial
4677 specialization we look at all template parameters except the
4679 parms = TREE_CHAIN (parms);
4681 /* Figure out what error message to issue. */
4682 if (is_friend_decl == 2)
4683 msg = G_("default template arguments may not be used in function template "
4684 "friend re-declaration");
4685 else if (is_friend_decl)
4686 msg = G_("default template arguments may not be used in function template "
4687 "friend declarations");
4688 else if (TREE_CODE (decl) == FUNCTION_DECL && (cxx_dialect == cxx98))
4689 msg = G_("default template arguments may not be used in function templates "
4690 "without -std=c++11 or -std=gnu++11");
4691 else if (is_partial)
4692 msg = G_("default template arguments may not be used in "
4693 "partial specializations");
4695 msg = G_("default argument for template parameter for class enclosing %qD");
4697 if (current_class_type && TYPE_BEING_DEFINED (current_class_type))
4698 /* If we're inside a class definition, there's no need to
4699 examine the parameters to the class itself. On the one
4700 hand, they will be checked when the class is defined, and,
4701 on the other, default arguments are valid in things like:
4702 template <class T = double>
4703 struct S { template <class U> void f(U); };
4704 Here the default argument for `S' has no bearing on the
4705 declaration of `f'. */
4706 last_level_to_check = template_class_depth (current_class_type) + 1;
4708 /* Check everything. */
4709 last_level_to_check = 0;
4711 for (parm_level = parms;
4712 parm_level && TMPL_PARMS_DEPTH (parm_level) >= last_level_to_check;
4713 parm_level = TREE_CHAIN (parm_level))
4715 tree inner_parms = TREE_VALUE (parm_level);
4719 ntparms = TREE_VEC_LENGTH (inner_parms);
4720 for (i = 0; i < ntparms; ++i)
4722 if (TREE_VEC_ELT (inner_parms, i) == error_mark_node)
4725 if (TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)))
4730 if (is_friend_decl == 2)
4737 /* Clear out the default argument so that we are not
4739 TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)) = NULL_TREE;
4743 /* At this point, if we're still interested in issuing messages,
4744 they must apply to classes surrounding the object declared. */
4746 msg = G_("default argument for template parameter for class "
4753 /* Worker for push_template_decl_real, called via
4754 for_each_template_parm. DATA is really an int, indicating the
4755 level of the parameters we are interested in. If T is a template
4756 parameter of that level, return nonzero. */
4759 template_parm_this_level_p (tree t, void* data)
4761 int this_level = *(int *)data;
4764 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
4765 level = TEMPLATE_PARM_LEVEL (t);
4767 level = TEMPLATE_TYPE_LEVEL (t);
4768 return level == this_level;
4771 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4772 parameters given by current_template_args, or reuses a
4773 previously existing one, if appropriate. Returns the DECL, or an
4774 equivalent one, if it is replaced via a call to duplicate_decls.
4776 If IS_FRIEND is true, DECL is a friend declaration. */
4779 push_template_decl_real (tree decl, bool is_friend)
4787 int new_template_p = 0;
4788 /* True if the template is a member template, in the sense of
4790 bool member_template_p = false;
4792 if (decl == error_mark_node || !current_template_parms)
4793 return error_mark_node;
4795 /* See if this is a partial specialization. */
4796 is_partial = (DECL_IMPLICIT_TYPEDEF_P (decl)
4797 && TREE_CODE (TREE_TYPE (decl)) != ENUMERAL_TYPE
4798 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)));
4800 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_FRIEND_P (decl))
4804 /* For a friend, we want the context of the friend function, not
4805 the type of which it is a friend. */
4806 ctx = CP_DECL_CONTEXT (decl);
4807 else if (CP_DECL_CONTEXT (decl)
4808 && TREE_CODE (CP_DECL_CONTEXT (decl)) != NAMESPACE_DECL)
4809 /* In the case of a virtual function, we want the class in which
4811 ctx = CP_DECL_CONTEXT (decl);
4813 /* Otherwise, if we're currently defining some class, the DECL
4814 is assumed to be a member of the class. */
4815 ctx = current_scope ();
4817 if (ctx && TREE_CODE (ctx) == NAMESPACE_DECL)
4820 if (!DECL_CONTEXT (decl))
4821 DECL_CONTEXT (decl) = FROB_CONTEXT (current_namespace);
4823 /* See if this is a primary template. */
4824 if (is_friend && ctx)
4825 /* A friend template that specifies a class context, i.e.
4826 template <typename T> friend void A<T>::f();
4830 primary = template_parm_scope_p ();
4834 if (DECL_CLASS_SCOPE_P (decl))
4835 member_template_p = true;
4836 if (TREE_CODE (decl) == TYPE_DECL
4837 && ANON_AGGRNAME_P (DECL_NAME (decl)))
4839 error ("template class without a name");
4840 return error_mark_node;
4842 else if (TREE_CODE (decl) == FUNCTION_DECL)
4844 if (DECL_DESTRUCTOR_P (decl))
4848 A destructor shall not be a member template. */
4849 error ("destructor %qD declared as member template", decl);
4850 return error_mark_node;
4852 if (NEW_DELETE_OPNAME_P (DECL_NAME (decl))
4853 && (!prototype_p (TREE_TYPE (decl))
4854 || TYPE_ARG_TYPES (TREE_TYPE (decl)) == void_list_node
4855 || !TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (decl)))
4856 || (TREE_CHAIN (TYPE_ARG_TYPES ((TREE_TYPE (decl))))
4857 == void_list_node)))
4859 /* [basic.stc.dynamic.allocation]
4861 An allocation function can be a function
4862 template. ... Template allocation functions shall
4863 have two or more parameters. */
4864 error ("invalid template declaration of %qD", decl);
4865 return error_mark_node;
4868 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4869 && CLASS_TYPE_P (TREE_TYPE (decl)))
4871 else if (TREE_CODE (decl) == TYPE_DECL
4872 && TYPE_DECL_ALIAS_P (decl))
4873 /* alias-declaration */
4874 gcc_assert (!DECL_ARTIFICIAL (decl));
4877 error ("template declaration of %q#D", decl);
4878 return error_mark_node;
4882 /* Check to see that the rules regarding the use of default
4883 arguments are not being violated. */
4884 check_default_tmpl_args (decl, current_template_parms,
4885 primary, is_partial, /*is_friend_decl=*/0);
4887 /* Ensure that there are no parameter packs in the type of this
4888 declaration that have not been expanded. */
4889 if (TREE_CODE (decl) == FUNCTION_DECL)
4891 /* Check each of the arguments individually to see if there are
4892 any bare parameter packs. */
4893 tree type = TREE_TYPE (decl);
4894 tree arg = DECL_ARGUMENTS (decl);
4895 tree argtype = TYPE_ARG_TYPES (type);
4897 while (arg && argtype)
4899 if (!FUNCTION_PARAMETER_PACK_P (arg)
4900 && check_for_bare_parameter_packs (TREE_TYPE (arg)))
4902 /* This is a PARM_DECL that contains unexpanded parameter
4903 packs. We have already complained about this in the
4904 check_for_bare_parameter_packs call, so just replace
4905 these types with ERROR_MARK_NODE. */
4906 TREE_TYPE (arg) = error_mark_node;
4907 TREE_VALUE (argtype) = error_mark_node;
4910 arg = DECL_CHAIN (arg);
4911 argtype = TREE_CHAIN (argtype);
4914 /* Check for bare parameter packs in the return type and the
4915 exception specifiers. */
4916 if (check_for_bare_parameter_packs (TREE_TYPE (type)))
4917 /* Errors were already issued, set return type to int
4918 as the frontend doesn't expect error_mark_node as
4920 TREE_TYPE (type) = integer_type_node;
4921 if (check_for_bare_parameter_packs (TYPE_RAISES_EXCEPTIONS (type)))
4922 TYPE_RAISES_EXCEPTIONS (type) = NULL_TREE;
4924 else if (check_for_bare_parameter_packs ((TREE_CODE (decl) == TYPE_DECL
4925 && TYPE_DECL_ALIAS_P (decl))
4926 ? DECL_ORIGINAL_TYPE (decl)
4927 : TREE_TYPE (decl)))
4929 TREE_TYPE (decl) = error_mark_node;
4930 return error_mark_node;
4934 return process_partial_specialization (decl);
4936 args = current_template_args ();
4939 || TREE_CODE (ctx) == FUNCTION_DECL
4940 || (CLASS_TYPE_P (ctx) && TYPE_BEING_DEFINED (ctx))
4941 || (is_friend && !DECL_TEMPLATE_INFO (decl)))
4943 if (DECL_LANG_SPECIFIC (decl)
4944 && DECL_TEMPLATE_INFO (decl)
4945 && DECL_TI_TEMPLATE (decl))
4946 tmpl = DECL_TI_TEMPLATE (decl);
4947 /* If DECL is a TYPE_DECL for a class-template, then there won't
4948 be DECL_LANG_SPECIFIC. The information equivalent to
4949 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4950 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4951 && TYPE_TEMPLATE_INFO (TREE_TYPE (decl))
4952 && TYPE_TI_TEMPLATE (TREE_TYPE (decl)))
4954 /* Since a template declaration already existed for this
4955 class-type, we must be redeclaring it here. Make sure
4956 that the redeclaration is valid. */
4957 redeclare_class_template (TREE_TYPE (decl),
4958 current_template_parms);
4959 /* We don't need to create a new TEMPLATE_DECL; just use the
4960 one we already had. */
4961 tmpl = TYPE_TI_TEMPLATE (TREE_TYPE (decl));
4965 tmpl = build_template_decl (decl, current_template_parms,
4969 if (DECL_LANG_SPECIFIC (decl)
4970 && DECL_TEMPLATE_SPECIALIZATION (decl))
4972 /* A specialization of a member template of a template
4974 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
4975 DECL_TEMPLATE_INFO (tmpl) = DECL_TEMPLATE_INFO (decl);
4976 DECL_TEMPLATE_INFO (decl) = NULL_TREE;
4982 tree a, t, current, parms;
4984 tree tinfo = get_template_info (decl);
4988 error ("template definition of non-template %q#D", decl);
4989 return error_mark_node;
4992 tmpl = TI_TEMPLATE (tinfo);
4994 if (DECL_FUNCTION_TEMPLATE_P (tmpl)
4995 && DECL_TEMPLATE_INFO (decl) && DECL_TI_ARGS (decl)
4996 && DECL_TEMPLATE_SPECIALIZATION (decl)
4997 && DECL_MEMBER_TEMPLATE_P (tmpl))
5001 /* The declaration is a specialization of a member
5002 template, declared outside the class. Therefore, the
5003 innermost template arguments will be NULL, so we
5004 replace them with the arguments determined by the
5005 earlier call to check_explicit_specialization. */
5006 args = DECL_TI_ARGS (decl);
5009 = build_template_decl (decl, current_template_parms,
5011 DECL_TEMPLATE_RESULT (new_tmpl) = decl;
5012 TREE_TYPE (new_tmpl) = TREE_TYPE (decl);
5013 DECL_TI_TEMPLATE (decl) = new_tmpl;
5014 SET_DECL_TEMPLATE_SPECIALIZATION (new_tmpl);
5015 DECL_TEMPLATE_INFO (new_tmpl)
5016 = build_template_info (tmpl, args);
5018 register_specialization (new_tmpl,
5019 most_general_template (tmpl),
5025 /* Make sure the template headers we got make sense. */
5027 parms = DECL_TEMPLATE_PARMS (tmpl);
5028 i = TMPL_PARMS_DEPTH (parms);
5029 if (TMPL_ARGS_DEPTH (args) != i)
5031 error ("expected %d levels of template parms for %q#D, got %d",
5032 i, decl, TMPL_ARGS_DEPTH (args));
5035 for (current = decl; i > 0; --i, parms = TREE_CHAIN (parms))
5037 a = TMPL_ARGS_LEVEL (args, i);
5038 t = INNERMOST_TEMPLATE_PARMS (parms);
5040 if (TREE_VEC_LENGTH (t) != TREE_VEC_LENGTH (a))
5042 if (current == decl)
5043 error ("got %d template parameters for %q#D",
5044 TREE_VEC_LENGTH (a), decl);
5046 error ("got %d template parameters for %q#T",
5047 TREE_VEC_LENGTH (a), current);
5048 error (" but %d required", TREE_VEC_LENGTH (t));
5049 return error_mark_node;
5052 if (current == decl)
5054 else if (current == NULL_TREE)
5055 /* Can happen in erroneous input. */
5058 current = (TYPE_P (current)
5059 ? TYPE_CONTEXT (current)
5060 : DECL_CONTEXT (current));
5063 /* Check that the parms are used in the appropriate qualifying scopes
5064 in the declarator. */
5065 if (!comp_template_args
5067 TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (tmpl)))))
5070 template arguments to %qD do not match original template %qD",
5071 decl, DECL_TEMPLATE_RESULT (tmpl));
5072 if (!uses_template_parms (TI_ARGS (tinfo)))
5073 inform (input_location, "use template<> for an explicit specialization");
5074 /* Avoid crash in import_export_decl. */
5075 DECL_INTERFACE_KNOWN (decl) = 1;
5076 return error_mark_node;
5080 DECL_TEMPLATE_RESULT (tmpl) = decl;
5081 TREE_TYPE (tmpl) = TREE_TYPE (decl);
5083 /* Push template declarations for global functions and types. Note
5084 that we do not try to push a global template friend declared in a
5085 template class; such a thing may well depend on the template
5086 parameters of the class. */
5087 if (new_template_p && !ctx
5088 && !(is_friend && template_class_depth (current_class_type) > 0))
5090 tmpl = pushdecl_namespace_level (tmpl, is_friend);
5091 if (tmpl == error_mark_node)
5092 return error_mark_node;
5094 /* Hide template friend classes that haven't been declared yet. */
5095 if (is_friend && TREE_CODE (decl) == TYPE_DECL)
5097 DECL_ANTICIPATED (tmpl) = 1;
5098 DECL_FRIEND_P (tmpl) = 1;
5104 tree parms = DECL_TEMPLATE_PARMS (tmpl);
5107 DECL_PRIMARY_TEMPLATE (tmpl) = tmpl;
5108 if (DECL_CONV_FN_P (tmpl))
5110 int depth = TMPL_PARMS_DEPTH (parms);
5112 /* It is a conversion operator. See if the type converted to
5113 depends on innermost template operands. */
5115 if (uses_template_parms_level (TREE_TYPE (TREE_TYPE (tmpl)),
5117 DECL_TEMPLATE_CONV_FN_P (tmpl) = 1;
5120 /* Give template template parms a DECL_CONTEXT of the template
5121 for which they are a parameter. */
5122 parms = INNERMOST_TEMPLATE_PARMS (parms);
5123 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
5125 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
5126 if (TREE_CODE (parm) == TEMPLATE_DECL)
5127 DECL_CONTEXT (parm) = tmpl;
5131 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5132 back to its most general template. If TMPL is a specialization,
5133 ARGS may only have the innermost set of arguments. Add the missing
5134 argument levels if necessary. */
5135 if (DECL_TEMPLATE_INFO (tmpl))
5136 args = add_outermost_template_args (DECL_TI_ARGS (tmpl), args);
5138 info = build_template_info (tmpl, args);
5140 if (DECL_IMPLICIT_TYPEDEF_P (decl))
5141 SET_TYPE_TEMPLATE_INFO (TREE_TYPE (tmpl), info);
5144 if (primary && !DECL_LANG_SPECIFIC (decl))
5145 retrofit_lang_decl (decl);
5146 if (DECL_LANG_SPECIFIC (decl))
5147 DECL_TEMPLATE_INFO (decl) = info;
5150 return DECL_TEMPLATE_RESULT (tmpl);
5154 push_template_decl (tree decl)
5156 return push_template_decl_real (decl, false);
5159 /* Called when a class template TYPE is redeclared with the indicated
5160 template PARMS, e.g.:
5162 template <class T> struct S;
5163 template <class T> struct S {}; */
5166 redeclare_class_template (tree type, tree parms)
5172 if (!TYPE_TEMPLATE_INFO (type))
5174 error ("%qT is not a template type", type);
5178 tmpl = TYPE_TI_TEMPLATE (type);
5179 if (!PRIMARY_TEMPLATE_P (tmpl))
5180 /* The type is nested in some template class. Nothing to worry
5181 about here; there are no new template parameters for the nested
5187 error ("template specifiers not specified in declaration of %qD",
5192 parms = INNERMOST_TEMPLATE_PARMS (parms);
5193 tmpl_parms = DECL_INNERMOST_TEMPLATE_PARMS (tmpl);
5195 if (TREE_VEC_LENGTH (parms) != TREE_VEC_LENGTH (tmpl_parms))
5197 error_n (input_location, TREE_VEC_LENGTH (parms),
5198 "redeclared with %d template parameter",
5199 "redeclared with %d template parameters",
5200 TREE_VEC_LENGTH (parms));
5201 inform_n (input_location, TREE_VEC_LENGTH (tmpl_parms),
5202 "previous declaration %q+D used %d template parameter",
5203 "previous declaration %q+D used %d template parameters",
5204 tmpl, TREE_VEC_LENGTH (tmpl_parms));
5208 for (i = 0; i < TREE_VEC_LENGTH (tmpl_parms); ++i)
5215 if (TREE_VEC_ELT (tmpl_parms, i) == error_mark_node
5216 || TREE_VEC_ELT (parms, i) == error_mark_node)
5219 tmpl_parm = TREE_VALUE (TREE_VEC_ELT (tmpl_parms, i));
5220 if (tmpl_parm == error_mark_node)
5223 parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
5224 tmpl_default = TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i));
5225 parm_default = TREE_PURPOSE (TREE_VEC_ELT (parms, i));
5227 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5229 if (TREE_CODE (tmpl_parm) != TREE_CODE (parm)
5230 || (TREE_CODE (tmpl_parm) != TYPE_DECL
5231 && !same_type_p (TREE_TYPE (tmpl_parm), TREE_TYPE (parm)))
5232 || (TREE_CODE (tmpl_parm) != PARM_DECL
5233 && (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (tmpl_parm))
5234 != TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm))))
5235 || (TREE_CODE (tmpl_parm) == PARM_DECL
5236 && (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (tmpl_parm))
5237 != TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))))
5239 error ("template parameter %q+#D", tmpl_parm);
5240 error ("redeclared here as %q#D", parm);
5244 if (tmpl_default != NULL_TREE && parm_default != NULL_TREE)
5246 /* We have in [temp.param]:
5248 A template-parameter may not be given default arguments
5249 by two different declarations in the same scope. */
5250 error_at (input_location, "redefinition of default argument for %q#D", parm);
5251 inform (DECL_SOURCE_LOCATION (tmpl_parm),
5252 "original definition appeared here");
5256 if (parm_default != NULL_TREE)
5257 /* Update the previous template parameters (which are the ones
5258 that will really count) with the new default value. */
5259 TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i)) = parm_default;
5260 else if (tmpl_default != NULL_TREE)
5261 /* Update the new parameters, too; they'll be used as the
5262 parameters for any members. */
5263 TREE_PURPOSE (TREE_VEC_ELT (parms, i)) = tmpl_default;
5269 /* Simplify EXPR if it is a non-dependent expression. Returns the
5270 (possibly simplified) expression. */
5273 fold_non_dependent_expr_sfinae (tree expr, tsubst_flags_t complain)
5275 if (expr == NULL_TREE)
5278 /* If we're in a template, but EXPR isn't value dependent, simplify
5279 it. We're supposed to treat:
5281 template <typename T> void f(T[1 + 1]);
5282 template <typename T> void f(T[2]);
5284 as two declarations of the same function, for example. */
5285 if (processing_template_decl
5286 && !type_dependent_expression_p (expr)
5287 && potential_constant_expression (expr)
5288 && !value_dependent_expression_p (expr))
5290 HOST_WIDE_INT saved_processing_template_decl;
5292 saved_processing_template_decl = processing_template_decl;
5293 processing_template_decl = 0;
5294 expr = tsubst_copy_and_build (expr,
5297 /*in_decl=*/NULL_TREE,
5298 /*function_p=*/false,
5299 /*integral_constant_expression_p=*/true);
5300 processing_template_decl = saved_processing_template_decl;
5306 fold_non_dependent_expr (tree expr)
5308 return fold_non_dependent_expr_sfinae (expr, tf_error);
5311 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5312 template declaration, or a TYPE_DECL for an alias declaration. */
5315 alias_type_or_template_p (tree t)
5319 return ((TREE_CODE (t) == TYPE_DECL && TYPE_DECL_ALIAS_P (t))
5322 && TYPE_DECL_ALIAS_P (TYPE_NAME (t)))
5323 || DECL_ALIAS_TEMPLATE_P (t));
5326 /* Return TRUE iff is a specialization of an alias template. */
5329 alias_template_specialization_p (tree t)
5333 return (primary_template_instantiation_p (t)
5334 && DECL_ALIAS_TEMPLATE_P (TYPE_TI_TEMPLATE (t)));
5337 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5338 must be a function or a pointer-to-function type, as specified
5339 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5340 and check that the resulting function has external linkage. */
5343 convert_nontype_argument_function (tree type, tree expr)
5347 linkage_kind linkage;
5349 fn = instantiate_type (type, fns, tf_none);
5350 if (fn == error_mark_node)
5351 return error_mark_node;
5354 if (TREE_CODE (fn_no_ptr) == ADDR_EXPR)
5355 fn_no_ptr = TREE_OPERAND (fn_no_ptr, 0);
5356 if (BASELINK_P (fn_no_ptr))
5357 fn_no_ptr = BASELINK_FUNCTIONS (fn_no_ptr);
5359 /* [temp.arg.nontype]/1
5361 A template-argument for a non-type, non-template template-parameter
5364 -- the address of an object or function with external [C++11: or
5365 internal] linkage. */
5366 linkage = decl_linkage (fn_no_ptr);
5367 if (cxx_dialect >= cxx0x ? linkage == lk_none : linkage != lk_external)
5369 if (cxx_dialect >= cxx0x)
5370 error ("%qE is not a valid template argument for type %qT "
5371 "because %qD has no linkage",
5372 expr, type, fn_no_ptr);
5374 error ("%qE is not a valid template argument for type %qT "
5375 "because %qD does not have external linkage",
5376 expr, type, fn_no_ptr);
5383 /* Subroutine of convert_nontype_argument.
5384 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5385 Emit an error otherwise. */
5388 check_valid_ptrmem_cst_expr (tree type, tree expr,
5389 tsubst_flags_t complain)
5392 if (expr && (null_ptr_cst_p (expr) || TREE_CODE (expr) == PTRMEM_CST))
5394 if (cxx_dialect >= cxx0x && null_member_pointer_value_p (expr))
5396 if (complain & tf_error)
5398 error ("%qE is not a valid template argument for type %qT",
5400 error ("it must be a pointer-to-member of the form %<&X::Y%>");
5405 /* Returns TRUE iff the address of OP is value-dependent.
5407 14.6.2.4 [temp.dep.temp]:
5408 A non-integral non-type template-argument is dependent if its type is
5409 dependent or it has either of the following forms
5412 and contains a nested-name-specifier which specifies a class-name that
5413 names a dependent type.
5415 We generalize this to just say that the address of a member of a
5416 dependent class is value-dependent; the above doesn't cover the
5417 address of a static data member named with an unqualified-id. */
5420 has_value_dependent_address (tree op)
5422 /* We could use get_inner_reference here, but there's no need;
5423 this is only relevant for template non-type arguments, which
5424 can only be expressed as &id-expression. */
5427 tree ctx = CP_DECL_CONTEXT (op);
5428 if (TYPE_P (ctx) && dependent_type_p (ctx))
5435 /* The next set of functions are used for providing helpful explanatory
5436 diagnostics for failed overload resolution. Their messages should be
5437 indented by two spaces for consistency with the messages in
5441 unify_success (bool explain_p ATTRIBUTE_UNUSED)
5447 unify_parameter_deduction_failure (bool explain_p, tree parm)
5450 inform (input_location,
5451 " couldn't deduce template parameter %qD", parm);
5456 unify_invalid (bool explain_p ATTRIBUTE_UNUSED)
5462 unify_cv_qual_mismatch (bool explain_p, tree parm, tree arg)
5465 inform (input_location,
5466 " types %qT and %qT have incompatible cv-qualifiers",
5472 unify_type_mismatch (bool explain_p, tree parm, tree arg)
5475 inform (input_location, " mismatched types %qT and %qT", parm, arg);
5480 unify_parameter_pack_mismatch (bool explain_p, tree parm, tree arg)
5483 inform (input_location,
5484 " template parameter %qD is not a parameter pack, but "
5491 unify_ptrmem_cst_mismatch (bool explain_p, tree parm, tree arg)
5494 inform (input_location,
5495 " template argument %qE does not match "
5496 "pointer-to-member constant %qE",
5502 unify_expression_unequal (bool explain_p, tree parm, tree arg)
5505 inform (input_location, " %qE is not equivalent to %qE", parm, arg);
5510 unify_parameter_pack_inconsistent (bool explain_p, tree old_arg, tree new_arg)
5513 inform (input_location,
5514 " inconsistent parameter pack deduction with %qT and %qT",
5520 unify_inconsistency (bool explain_p, tree parm, tree first, tree second)
5525 inform (input_location,
5526 " deduced conflicting types for parameter %qT (%qT and %qT)",
5527 parm, first, second);
5529 inform (input_location,
5530 " deduced conflicting values for non-type parameter "
5531 "%qE (%qE and %qE)", parm, first, second);
5537 unify_vla_arg (bool explain_p, tree arg)
5540 inform (input_location,
5541 " variable-sized array type %qT is not "
5542 "a valid template argument",
5548 unify_method_type_error (bool explain_p, tree arg)
5551 inform (input_location,
5552 " member function type %qT is not a valid template argument",
5558 unify_arity (bool explain_p, int have, int wanted)
5561 inform_n (input_location, wanted,
5562 " candidate expects %d argument, %d provided",
5563 " candidate expects %d arguments, %d provided",
5569 unify_too_many_arguments (bool explain_p, int have, int wanted)
5571 return unify_arity (explain_p, have, wanted);
5575 unify_too_few_arguments (bool explain_p, int have, int wanted)
5577 return unify_arity (explain_p, have, wanted);
5581 unify_arg_conversion (bool explain_p, tree to_type,
5582 tree from_type, tree arg)
5585 inform (input_location, " cannot convert %qE (type %qT) to type %qT",
5586 arg, from_type, to_type);
5591 unify_no_common_base (bool explain_p, enum template_base_result r,
5592 tree parm, tree arg)
5597 case tbr_ambiguous_baseclass:
5598 inform (input_location, " %qT is an ambiguous base class of %qT",
5602 inform (input_location, " %qT is not derived from %qT", arg, parm);
5609 unify_inconsistent_template_template_parameters (bool explain_p)
5612 inform (input_location,
5613 " template parameters of a template template argument are "
5614 "inconsistent with other deduced template arguments");
5619 unify_template_deduction_failure (bool explain_p, tree parm, tree arg)
5622 inform (input_location,
5623 " can't deduce a template for %qT from non-template type %qT",
5629 unify_template_argument_mismatch (bool explain_p, tree parm, tree arg)
5632 inform (input_location,
5633 " template argument %qE does not match %qD", arg, parm);
5638 unify_overload_resolution_failure (bool explain_p, tree arg)
5641 inform (input_location,
5642 " could not resolve address from overloaded function %qE",
5647 /* Attempt to convert the non-type template parameter EXPR to the
5648 indicated TYPE. If the conversion is successful, return the
5649 converted value. If the conversion is unsuccessful, return
5650 NULL_TREE if we issued an error message, or error_mark_node if we
5651 did not. We issue error messages for out-and-out bad template
5652 parameters, but not simply because the conversion failed, since we
5653 might be just trying to do argument deduction. Both TYPE and EXPR
5654 must be non-dependent.
5656 The conversion follows the special rules described in
5657 [temp.arg.nontype], and it is much more strict than an implicit
5660 This function is called twice for each template argument (see
5661 lookup_template_class for a more accurate description of this
5662 problem). This means that we need to handle expressions which
5663 are not valid in a C++ source, but can be created from the
5664 first call (for instance, casts to perform conversions). These
5665 hacks can go away after we fix the double coercion problem. */
5668 convert_nontype_argument (tree type, tree expr, tsubst_flags_t complain)
5672 /* Detect immediately string literals as invalid non-type argument.
5673 This special-case is not needed for correctness (we would easily
5674 catch this later), but only to provide better diagnostic for this
5675 common user mistake. As suggested by DR 100, we do not mention
5676 linkage issues in the diagnostic as this is not the point. */
5677 /* FIXME we're making this OK. */
5678 if (TREE_CODE (expr) == STRING_CST)
5680 if (complain & tf_error)
5681 error ("%qE is not a valid template argument for type %qT "
5682 "because string literals can never be used in this context",
5687 /* Add the ADDR_EXPR now for the benefit of
5688 value_dependent_expression_p. */
5689 if (TYPE_PTROBV_P (type)
5690 && TREE_CODE (TREE_TYPE (expr)) == ARRAY_TYPE)
5691 expr = decay_conversion (expr);
5693 /* If we are in a template, EXPR may be non-dependent, but still
5694 have a syntactic, rather than semantic, form. For example, EXPR
5695 might be a SCOPE_REF, rather than the VAR_DECL to which the
5696 SCOPE_REF refers. Preserving the qualifying scope is necessary
5697 so that access checking can be performed when the template is
5698 instantiated -- but here we need the resolved form so that we can
5699 convert the argument. */
5700 if (TYPE_REF_OBJ_P (type)
5701 && has_value_dependent_address (expr))
5702 /* If we want the address and it's value-dependent, don't fold. */;
5703 else if (!type_unknown_p (expr))
5704 expr = fold_non_dependent_expr_sfinae (expr, complain);
5705 if (error_operand_p (expr))
5706 return error_mark_node;
5707 expr_type = TREE_TYPE (expr);
5708 if (TREE_CODE (type) == REFERENCE_TYPE)
5709 expr = mark_lvalue_use (expr);
5711 expr = mark_rvalue_use (expr);
5713 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
5714 to a non-type argument of "nullptr". */
5715 if (expr == nullptr_node
5716 && (TYPE_PTR_P (type) || TYPE_PTR_TO_MEMBER_P (type)))
5717 expr = convert (type, expr);
5719 /* In C++11, integral or enumeration non-type template arguments can be
5720 arbitrary constant expressions. Pointer and pointer to
5721 member arguments can be general constant expressions that evaluate
5722 to a null value, but otherwise still need to be of a specific form. */
5723 if (cxx_dialect >= cxx0x)
5725 if (TREE_CODE (expr) == PTRMEM_CST)
5726 /* A PTRMEM_CST is already constant, and a valid template
5727 argument for a parameter of pointer to member type, we just want
5728 to leave it in that form rather than lower it to a
5730 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
5731 expr = maybe_constant_value (expr);
5732 else if (TYPE_PTR_P (type)
5733 || TYPE_PTR_TO_MEMBER_P (type))
5735 tree folded = maybe_constant_value (expr);
5736 if (TYPE_PTR_P (type) ? integer_zerop (folded)
5737 : null_member_pointer_value_p (folded))
5742 /* HACK: Due to double coercion, we can get a
5743 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5744 which is the tree that we built on the first call (see
5745 below when coercing to reference to object or to reference to
5746 function). We just strip everything and get to the arg.
5747 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5749 if (TYPE_REF_OBJ_P (type) || TYPE_REFFN_P (type))
5751 tree probe_type, probe = expr;
5752 if (REFERENCE_REF_P (probe))
5753 probe = TREE_OPERAND (probe, 0);
5754 probe_type = TREE_TYPE (probe);
5755 if (TREE_CODE (probe) == NOP_EXPR)
5757 /* ??? Maybe we could use convert_from_reference here, but we
5758 would need to relax its constraints because the NOP_EXPR
5759 could actually change the type to something more cv-qualified,
5760 and this is not folded by convert_from_reference. */
5761 tree addr = TREE_OPERAND (probe, 0);
5762 gcc_assert (TREE_CODE (probe_type) == REFERENCE_TYPE);
5763 gcc_assert (TREE_CODE (addr) == ADDR_EXPR);
5764 gcc_assert (TREE_CODE (TREE_TYPE (addr)) == POINTER_TYPE);
5765 gcc_assert (same_type_ignoring_top_level_qualifiers_p
5766 (TREE_TYPE (probe_type),
5767 TREE_TYPE (TREE_TYPE (addr))));
5769 expr = TREE_OPERAND (addr, 0);
5770 expr_type = TREE_TYPE (expr);
5774 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5775 parameter is a pointer to object, through decay and
5776 qualification conversion. Let's strip everything. */
5777 else if (TREE_CODE (expr) == NOP_EXPR && TYPE_PTROBV_P (type))
5780 gcc_assert (TREE_CODE (expr) == ADDR_EXPR);
5781 gcc_assert (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE);
5782 /* Skip the ADDR_EXPR only if it is part of the decay for
5783 an array. Otherwise, it is part of the original argument
5784 in the source code. */
5785 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == ARRAY_TYPE)
5786 expr = TREE_OPERAND (expr, 0);
5787 expr_type = TREE_TYPE (expr);
5790 /* [temp.arg.nontype]/5, bullet 1
5792 For a non-type template-parameter of integral or enumeration type,
5793 integral promotions (_conv.prom_) and integral conversions
5794 (_conv.integral_) are applied. */
5795 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
5797 tree t = build_integral_nontype_arg_conv (type, expr, complain);
5798 t = maybe_constant_value (t);
5799 if (t != error_mark_node)
5802 if (!same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (expr)))
5803 return error_mark_node;
5805 /* Notice that there are constant expressions like '4 % 0' which
5806 do not fold into integer constants. */
5807 if (TREE_CODE (expr) != INTEGER_CST)
5809 if (complain & tf_error)
5811 int errs = errorcount, warns = warningcount;
5812 if (processing_template_decl
5813 && !require_potential_constant_expression (expr))
5815 expr = cxx_constant_value (expr);
5816 if (errorcount > errs || warningcount > warns)
5817 inform (EXPR_LOC_OR_HERE (expr),
5818 "in template argument for type %qT ", type);
5819 if (expr == error_mark_node)
5821 /* else cxx_constant_value complained but gave us
5822 a real constant, so go ahead. */
5823 gcc_assert (TREE_CODE (expr) == INTEGER_CST);
5829 /* [temp.arg.nontype]/5, bullet 2
5831 For a non-type template-parameter of type pointer to object,
5832 qualification conversions (_conv.qual_) and the array-to-pointer
5833 conversion (_conv.array_) are applied. */
5834 else if (TYPE_PTROBV_P (type))
5836 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5838 A template-argument for a non-type, non-template template-parameter
5839 shall be one of: [...]
5841 -- the name of a non-type template-parameter;
5842 -- the address of an object or function with external linkage, [...]
5843 expressed as "& id-expression" where the & is optional if the name
5844 refers to a function or array, or if the corresponding
5845 template-parameter is a reference.
5847 Here, we do not care about functions, as they are invalid anyway
5848 for a parameter of type pointer-to-object. */
5850 if (DECL_P (expr) && DECL_TEMPLATE_PARM_P (expr))
5851 /* Non-type template parameters are OK. */
5853 else if (cxx_dialect >= cxx0x && integer_zerop (expr))
5854 /* Null pointer values are OK in C++11. */;
5855 else if (TREE_CODE (expr) != ADDR_EXPR
5856 && TREE_CODE (expr_type) != ARRAY_TYPE)
5858 if (TREE_CODE (expr) == VAR_DECL)
5860 error ("%qD is not a valid template argument "
5861 "because %qD is a variable, not the address of "
5866 /* Other values, like integer constants, might be valid
5867 non-type arguments of some other type. */
5868 return error_mark_node;
5874 decl = ((TREE_CODE (expr) == ADDR_EXPR)
5875 ? TREE_OPERAND (expr, 0) : expr);
5876 if (TREE_CODE (decl) != VAR_DECL)
5878 error ("%qE is not a valid template argument of type %qT "
5879 "because %qE is not a variable",
5883 else if (cxx_dialect < cxx0x && !DECL_EXTERNAL_LINKAGE_P (decl))
5885 error ("%qE is not a valid template argument of type %qT "
5886 "because %qD does not have external linkage",
5890 else if (cxx_dialect >= cxx0x && decl_linkage (decl) == lk_none)
5892 error ("%qE is not a valid template argument of type %qT "
5893 "because %qD has no linkage",
5899 expr = decay_conversion (expr);
5900 if (expr == error_mark_node)
5901 return error_mark_node;
5903 expr = perform_qualification_conversions (type, expr);
5904 if (expr == error_mark_node)
5905 return error_mark_node;
5907 /* [temp.arg.nontype]/5, bullet 3
5909 For a non-type template-parameter of type reference to object, no
5910 conversions apply. The type referred to by the reference may be more
5911 cv-qualified than the (otherwise identical) type of the
5912 template-argument. The template-parameter is bound directly to the
5913 template-argument, which must be an lvalue. */
5914 else if (TYPE_REF_OBJ_P (type))
5916 if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type),
5918 return error_mark_node;
5920 if (!at_least_as_qualified_p (TREE_TYPE (type), expr_type))
5922 error ("%qE is not a valid template argument for type %qT "
5923 "because of conflicts in cv-qualification", expr, type);
5927 if (!real_lvalue_p (expr))
5929 error ("%qE is not a valid template argument for type %qT "
5930 "because it is not an lvalue", expr, type);
5934 /* [temp.arg.nontype]/1
5936 A template-argument for a non-type, non-template template-parameter
5937 shall be one of: [...]
5939 -- the address of an object or function with external linkage. */
5940 if (TREE_CODE (expr) == INDIRECT_REF
5941 && TYPE_REF_OBJ_P (TREE_TYPE (TREE_OPERAND (expr, 0))))
5943 expr = TREE_OPERAND (expr, 0);
5946 error ("%q#D is not a valid template argument for type %qT "
5947 "because a reference variable does not have a constant "
5948 "address", expr, type);
5955 error ("%qE is not a valid template argument for type %qT "
5956 "because it is not an object with external linkage",
5961 if (!DECL_EXTERNAL_LINKAGE_P (expr))
5963 error ("%qE is not a valid template argument for type %qT "
5964 "because object %qD has not external linkage",
5969 expr = build_nop (type, build_address (expr));
5971 /* [temp.arg.nontype]/5, bullet 4
5973 For a non-type template-parameter of type pointer to function, only
5974 the function-to-pointer conversion (_conv.func_) is applied. If the
5975 template-argument represents a set of overloaded functions (or a
5976 pointer to such), the matching function is selected from the set
5978 else if (TYPE_PTRFN_P (type))
5980 /* If the argument is a template-id, we might not have enough
5981 context information to decay the pointer. */
5982 if (!type_unknown_p (expr_type))
5984 expr = decay_conversion (expr);
5985 if (expr == error_mark_node)
5986 return error_mark_node;
5989 if (cxx_dialect >= cxx0x && integer_zerop (expr))
5990 /* Null pointer values are OK in C++11. */
5991 return perform_qualification_conversions (type, expr);
5993 expr = convert_nontype_argument_function (type, expr);
5994 if (!expr || expr == error_mark_node)
5997 if (TREE_CODE (expr) != ADDR_EXPR)
5999 error ("%qE is not a valid template argument for type %qT", expr, type);
6000 error ("it must be the address of a function with external linkage");
6004 /* [temp.arg.nontype]/5, bullet 5
6006 For a non-type template-parameter of type reference to function, no
6007 conversions apply. If the template-argument represents a set of
6008 overloaded functions, the matching function is selected from the set
6010 else if (TYPE_REFFN_P (type))
6012 if (TREE_CODE (expr) == ADDR_EXPR)
6014 error ("%qE is not a valid template argument for type %qT "
6015 "because it is a pointer", expr, type);
6016 inform (input_location, "try using %qE instead", TREE_OPERAND (expr, 0));
6020 expr = convert_nontype_argument_function (TREE_TYPE (type), expr);
6021 if (!expr || expr == error_mark_node)
6024 expr = build_nop (type, build_address (expr));
6026 /* [temp.arg.nontype]/5, bullet 6
6028 For a non-type template-parameter of type pointer to member function,
6029 no conversions apply. If the template-argument represents a set of
6030 overloaded member functions, the matching member function is selected
6031 from the set (_over.over_). */
6032 else if (TYPE_PTRMEMFUNC_P (type))
6034 expr = instantiate_type (type, expr, tf_none);
6035 if (expr == error_mark_node)
6036 return error_mark_node;
6038 /* [temp.arg.nontype] bullet 1 says the pointer to member
6039 expression must be a pointer-to-member constant. */
6040 if (!check_valid_ptrmem_cst_expr (type, expr, complain))
6041 return error_mark_node;
6043 /* There is no way to disable standard conversions in
6044 resolve_address_of_overloaded_function (called by
6045 instantiate_type). It is possible that the call succeeded by
6046 converting &B::I to &D::I (where B is a base of D), so we need
6047 to reject this conversion here.
6049 Actually, even if there was a way to disable standard conversions,
6050 it would still be better to reject them here so that we can
6051 provide a superior diagnostic. */
6052 if (!same_type_p (TREE_TYPE (expr), type))
6054 error ("%qE is not a valid template argument for type %qT "
6055 "because it is of type %qT", expr, type,
6057 /* If we are just one standard conversion off, explain. */
6058 if (can_convert (type, TREE_TYPE (expr)))
6059 inform (input_location,
6060 "standard conversions are not allowed in this context");
6064 /* [temp.arg.nontype]/5, bullet 7
6066 For a non-type template-parameter of type pointer to data member,
6067 qualification conversions (_conv.qual_) are applied. */
6068 else if (TYPE_PTRMEM_P (type))
6070 /* [temp.arg.nontype] bullet 1 says the pointer to member
6071 expression must be a pointer-to-member constant. */
6072 if (!check_valid_ptrmem_cst_expr (type, expr, complain))
6073 return error_mark_node;
6075 expr = perform_qualification_conversions (type, expr);
6076 if (expr == error_mark_node)
6079 else if (NULLPTR_TYPE_P (type))
6081 if (expr != nullptr_node)
6083 error ("%qE is not a valid template argument for type %qT "
6084 "because it is of type %qT", expr, type, TREE_TYPE (expr));
6089 /* A template non-type parameter must be one of the above. */
6093 /* Sanity check: did we actually convert the argument to the
6095 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6096 (type, TREE_TYPE (expr)));
6100 /* Subroutine of coerce_template_template_parms, which returns 1 if
6101 PARM_PARM and ARG_PARM match using the rule for the template
6102 parameters of template template parameters. Both PARM and ARG are
6103 template parameters; the rest of the arguments are the same as for
6104 coerce_template_template_parms.
6107 coerce_template_template_parm (tree parm,
6109 tsubst_flags_t complain,
6113 if (arg == NULL_TREE || arg == error_mark_node
6114 || parm == NULL_TREE || parm == error_mark_node)
6117 if (TREE_CODE (arg) != TREE_CODE (parm))
6120 switch (TREE_CODE (parm))
6123 /* We encounter instantiations of templates like
6124 template <template <template <class> class> class TT>
6127 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
6128 tree argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
6130 if (!coerce_template_template_parms
6131 (parmparm, argparm, complain, in_decl, outer_args))
6137 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (arg))
6138 && !TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
6139 /* Argument is a parameter pack but parameter is not. */
6144 /* The tsubst call is used to handle cases such as
6146 template <int> class C {};
6147 template <class T, template <T> class TT> class D {};
6150 i.e. the parameter list of TT depends on earlier parameters. */
6151 if (!uses_template_parms (TREE_TYPE (arg))
6153 (tsubst (TREE_TYPE (parm), outer_args, complain, in_decl),
6157 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (arg))
6158 && !TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
6159 /* Argument is a parameter pack but parameter is not. */
6172 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
6173 template template parameters. Both PARM_PARMS and ARG_PARMS are
6174 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
6177 Consider the example:
6178 template <class T> class A;
6179 template<template <class U> class TT> class B;
6181 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
6182 the parameters to A, and OUTER_ARGS contains A. */
6185 coerce_template_template_parms (tree parm_parms,
6187 tsubst_flags_t complain,
6191 int nparms, nargs, i;
6195 gcc_assert (TREE_CODE (parm_parms) == TREE_VEC);
6196 gcc_assert (TREE_CODE (arg_parms) == TREE_VEC);
6198 nparms = TREE_VEC_LENGTH (parm_parms);
6199 nargs = TREE_VEC_LENGTH (arg_parms);
6201 /* Determine whether we have a parameter pack at the end of the
6202 template template parameter's template parameter list. */
6203 if (TREE_VEC_ELT (parm_parms, nparms - 1) != error_mark_node)
6205 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, nparms - 1));
6207 if (parm == error_mark_node)
6210 switch (TREE_CODE (parm))
6214 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
6219 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
6229 && !(variadic_p && nargs >= nparms - 1))
6232 /* Check all of the template parameters except the parameter pack at
6233 the end (if any). */
6234 for (i = 0; i < nparms - variadic_p; ++i)
6236 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node
6237 || TREE_VEC_ELT (arg_parms, i) == error_mark_node)
6240 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
6241 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
6243 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
6251 /* Check each of the template parameters in the template
6252 argument against the template parameter pack at the end of
6253 the template template parameter. */
6254 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node)
6257 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
6259 for (; i < nargs; ++i)
6261 if (TREE_VEC_ELT (arg_parms, i) == error_mark_node)
6264 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
6266 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
6275 /* Verifies that the deduced template arguments (in TARGS) for the
6276 template template parameters (in TPARMS) represent valid bindings,
6277 by comparing the template parameter list of each template argument
6278 to the template parameter list of its corresponding template
6279 template parameter, in accordance with DR150. This
6280 routine can only be called after all template arguments have been
6281 deduced. It will return TRUE if all of the template template
6282 parameter bindings are okay, FALSE otherwise. */
6284 template_template_parm_bindings_ok_p (tree tparms, tree targs)
6286 int i, ntparms = TREE_VEC_LENGTH (tparms);
6289 /* We're dealing with template parms in this process. */
6290 ++processing_template_decl;
6292 targs = INNERMOST_TEMPLATE_ARGS (targs);
6294 for (i = 0; i < ntparms; ++i)
6296 tree tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
6297 tree targ = TREE_VEC_ELT (targs, i);
6299 if (TREE_CODE (tparm) == TEMPLATE_DECL && targ)
6301 tree packed_args = NULL_TREE;
6304 if (ARGUMENT_PACK_P (targ))
6306 /* Look inside the argument pack. */
6307 packed_args = ARGUMENT_PACK_ARGS (targ);
6308 len = TREE_VEC_LENGTH (packed_args);
6311 for (idx = 0; idx < len; ++idx)
6313 tree targ_parms = NULL_TREE;
6316 /* Extract the next argument from the argument
6318 targ = TREE_VEC_ELT (packed_args, idx);
6320 if (PACK_EXPANSION_P (targ))
6321 /* Look at the pattern of the pack expansion. */
6322 targ = PACK_EXPANSION_PATTERN (targ);
6324 /* Extract the template parameters from the template
6326 if (TREE_CODE (targ) == TEMPLATE_DECL)
6327 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (targ);
6328 else if (TREE_CODE (targ) == TEMPLATE_TEMPLATE_PARM)
6329 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (TYPE_NAME (targ));
6331 /* Verify that we can coerce the template template
6332 parameters from the template argument to the template
6333 parameter. This requires an exact match. */
6335 && !coerce_template_template_parms
6336 (DECL_INNERMOST_TEMPLATE_PARMS (tparm),
6351 --processing_template_decl;
6355 /* Since type attributes aren't mangled, we need to strip them from
6356 template type arguments. */
6359 canonicalize_type_argument (tree arg, tsubst_flags_t complain)
6362 if (!arg || arg == error_mark_node || arg == TYPE_CANONICAL (arg))
6364 mv = TYPE_MAIN_VARIANT (arg);
6365 arg = strip_typedefs (arg);
6366 if (TYPE_ALIGN (arg) != TYPE_ALIGN (mv)
6367 || TYPE_ATTRIBUTES (arg) != TYPE_ATTRIBUTES (mv))
6369 if (complain & tf_warning)
6370 warning (0, "ignoring attributes on template argument %qT", arg);
6371 arg = build_aligned_type (arg, TYPE_ALIGN (mv));
6372 arg = cp_build_type_attribute_variant (arg, TYPE_ATTRIBUTES (mv));
6377 /* Convert the indicated template ARG as necessary to match the
6378 indicated template PARM. Returns the converted ARG, or
6379 error_mark_node if the conversion was unsuccessful. Error and
6380 warning messages are issued under control of COMPLAIN. This
6381 conversion is for the Ith parameter in the parameter list. ARGS is
6382 the full set of template arguments deduced so far. */
6385 convert_template_argument (tree parm,
6388 tsubst_flags_t complain,
6394 int is_type, requires_type, is_tmpl_type, requires_tmpl_type;
6396 if (TREE_CODE (arg) == TREE_LIST
6397 && TREE_CODE (TREE_VALUE (arg)) == OFFSET_REF)
6399 /* The template argument was the name of some
6400 member function. That's usually
6401 invalid, but static members are OK. In any
6402 case, grab the underlying fields/functions
6403 and issue an error later if required. */
6404 orig_arg = TREE_VALUE (arg);
6405 TREE_TYPE (arg) = unknown_type_node;
6410 requires_tmpl_type = TREE_CODE (parm) == TEMPLATE_DECL;
6411 requires_type = (TREE_CODE (parm) == TYPE_DECL
6412 || requires_tmpl_type);
6414 /* When determining whether an argument pack expansion is a template,
6415 look at the pattern. */
6416 if (TREE_CODE (arg) == TYPE_PACK_EXPANSION)
6417 arg = PACK_EXPANSION_PATTERN (arg);
6419 /* Deal with an injected-class-name used as a template template arg. */
6420 if (requires_tmpl_type && CLASS_TYPE_P (arg))
6422 tree t = maybe_get_template_decl_from_type_decl (TYPE_NAME (arg));
6423 if (TREE_CODE (t) == TEMPLATE_DECL)
6425 if (cxx_dialect >= cxx0x)
6426 /* OK under DR 1004. */;
6427 else if (complain & tf_warning_or_error)
6428 pedwarn (input_location, OPT_pedantic, "injected-class-name %qD"
6429 " used as template template argument", TYPE_NAME (arg));
6430 else if (flag_pedantic_errors)
6438 ((TREE_CODE (arg) == TEMPLATE_DECL
6439 && TREE_CODE (DECL_TEMPLATE_RESULT (arg)) == TYPE_DECL)
6440 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
6441 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE);
6444 && (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
6445 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE))
6446 arg = TYPE_STUB_DECL (arg);
6448 is_type = TYPE_P (arg) || is_tmpl_type;
6450 if (requires_type && ! is_type && TREE_CODE (arg) == SCOPE_REF
6451 && TREE_CODE (TREE_OPERAND (arg, 0)) == TEMPLATE_TYPE_PARM)
6453 if (TREE_CODE (TREE_OPERAND (arg, 1)) == BIT_NOT_EXPR)
6455 if (complain & tf_error)
6456 error ("invalid use of destructor %qE as a type", orig_arg);
6457 return error_mark_node;
6460 permerror (input_location,
6461 "to refer to a type member of a template parameter, "
6462 "use %<typename %E%>", orig_arg);
6464 orig_arg = make_typename_type (TREE_OPERAND (arg, 0),
6465 TREE_OPERAND (arg, 1),
6467 complain & tf_error);
6471 if (is_type != requires_type)
6475 if (complain & tf_error)
6477 error ("type/value mismatch at argument %d in template "
6478 "parameter list for %qD",
6481 error (" expected a constant of type %qT, got %qT",
6483 (DECL_P (arg) ? DECL_NAME (arg) : orig_arg));
6484 else if (requires_tmpl_type)
6485 error (" expected a class template, got %qE", orig_arg);
6487 error (" expected a type, got %qE", orig_arg);
6490 return error_mark_node;
6492 if (is_tmpl_type ^ requires_tmpl_type)
6494 if (in_decl && (complain & tf_error))
6496 error ("type/value mismatch at argument %d in template "
6497 "parameter list for %qD",
6500 error (" expected a type, got %qT", DECL_NAME (arg));
6502 error (" expected a class template, got %qT", orig_arg);
6504 return error_mark_node;
6509 if (requires_tmpl_type)
6511 if (TREE_CODE (TREE_TYPE (arg)) == UNBOUND_CLASS_TEMPLATE)
6512 /* The number of argument required is not known yet.
6513 Just accept it for now. */
6514 val = TREE_TYPE (arg);
6517 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
6520 argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
6522 if (coerce_template_template_parms (parmparm, argparm,
6528 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6530 if (val != error_mark_node)
6532 if (DECL_TEMPLATE_TEMPLATE_PARM_P (val))
6533 val = TREE_TYPE (val);
6534 if (TREE_CODE (orig_arg) == TYPE_PACK_EXPANSION)
6535 val = make_pack_expansion (val);
6540 if (in_decl && (complain & tf_error))
6542 error ("type/value mismatch at argument %d in "
6543 "template parameter list for %qD",
6545 error (" expected a template of type %qD, got %qT",
6549 val = error_mark_node;
6555 /* We only form one instance of each template specialization.
6556 Therefore, if we use a non-canonical variant (i.e., a
6557 typedef), any future messages referring to the type will use
6558 the typedef, which is confusing if those future uses do not
6559 themselves also use the typedef. */
6561 val = canonicalize_type_argument (val, complain);
6565 tree t = tsubst (TREE_TYPE (parm), args, complain, in_decl);
6567 if (invalid_nontype_parm_type_p (t, complain))
6568 return error_mark_node;
6570 if (template_parameter_pack_p (parm) && ARGUMENT_PACK_P (orig_arg))
6572 if (same_type_p (t, TREE_TYPE (orig_arg)))
6576 /* Not sure if this is reachable, but it doesn't hurt
6578 error ("type mismatch in nontype parameter pack");
6579 val = error_mark_node;
6582 else if (!uses_template_parms (orig_arg) && !uses_template_parms (t))
6583 /* We used to call digest_init here. However, digest_init
6584 will report errors, which we don't want when complain
6585 is zero. More importantly, digest_init will try too
6586 hard to convert things: for example, `0' should not be
6587 converted to pointer type at this point according to
6588 the standard. Accepting this is not merely an
6589 extension, since deciding whether or not these
6590 conversions can occur is part of determining which
6591 function template to call, or whether a given explicit
6592 argument specification is valid. */
6593 val = convert_nontype_argument (t, orig_arg, complain);
6597 if (val == NULL_TREE)
6598 val = error_mark_node;
6599 else if (val == error_mark_node && (complain & tf_error))
6600 error ("could not convert template argument %qE to %qT", orig_arg, t);
6602 if (TREE_CODE (val) == SCOPE_REF)
6604 /* Strip typedefs from the SCOPE_REF. */
6605 tree type = canonicalize_type_argument (TREE_TYPE (val), complain);
6606 tree scope = canonicalize_type_argument (TREE_OPERAND (val, 0),
6608 val = build_qualified_name (type, scope, TREE_OPERAND (val, 1),
6609 QUALIFIED_NAME_IS_TEMPLATE (val));
6616 /* Coerces the remaining template arguments in INNER_ARGS (from
6617 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6618 Returns the coerced argument pack. PARM_IDX is the position of this
6619 parameter in the template parameter list. ARGS is the original
6620 template argument list. */
6622 coerce_template_parameter_pack (tree parms,
6630 tsubst_flags_t complain)
6632 tree parm = TREE_VEC_ELT (parms, parm_idx);
6633 int nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
6636 tree packed_types = NULL_TREE;
6638 if (arg_idx > nargs)
6641 packed_args = make_tree_vec (nargs - arg_idx);
6643 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL
6644 && uses_parameter_packs (TREE_TYPE (TREE_VALUE (parm))))
6646 /* When the template parameter is a non-type template
6647 parameter pack whose type uses parameter packs, we need
6648 to look at each of the template arguments
6649 separately. Build a vector of the types for these
6650 non-type template parameters in PACKED_TYPES. */
6652 = make_pack_expansion (TREE_TYPE (TREE_VALUE (parm)));
6653 packed_types = tsubst_pack_expansion (expansion, args,
6656 if (packed_types == error_mark_node)
6657 return error_mark_node;
6659 /* Check that we have the right number of arguments. */
6661 && !PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx))
6662 && nargs - arg_idx != TREE_VEC_LENGTH (packed_types))
6665 = TREE_VEC_LENGTH (parms) - 1 + TREE_VEC_LENGTH (packed_types);
6666 error ("wrong number of template arguments (%d, should be %d)",
6667 nargs, needed_parms);
6668 return error_mark_node;
6671 /* If we aren't able to check the actual arguments now
6672 (because they haven't been expanded yet), we can at least
6673 verify that all of the types used for the non-type
6674 template parameter pack are, in fact, valid for non-type
6675 template parameters. */
6677 && PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx)))
6679 int j, len = TREE_VEC_LENGTH (packed_types);
6680 for (j = 0; j < len; ++j)
6682 tree t = TREE_VEC_ELT (packed_types, j);
6683 if (invalid_nontype_parm_type_p (t, complain))
6684 return error_mark_node;
6689 /* Convert the remaining arguments, which will be a part of the
6690 parameter pack "parm". */
6691 for (; arg_idx < nargs; ++arg_idx)
6693 tree arg = TREE_VEC_ELT (inner_args, arg_idx);
6694 tree actual_parm = TREE_VALUE (parm);
6696 if (packed_types && !PACK_EXPANSION_P (arg))
6698 /* When we have a vector of types (corresponding to the
6699 non-type template parameter pack that uses parameter
6700 packs in its type, as mention above), and the
6701 argument is not an expansion (which expands to a
6702 currently unknown number of arguments), clone the
6703 parm and give it the next type in PACKED_TYPES. */
6704 actual_parm = copy_node (actual_parm);
6705 TREE_TYPE (actual_parm) =
6706 TREE_VEC_ELT (packed_types, arg_idx - parm_idx);
6709 if (arg != error_mark_node)
6710 arg = convert_template_argument (actual_parm,
6711 arg, new_args, complain, parm_idx,
6713 if (arg == error_mark_node)
6715 TREE_VEC_ELT (packed_args, arg_idx - parm_idx) = arg;
6718 if (TREE_CODE (TREE_VALUE (parm)) == TYPE_DECL
6719 || TREE_CODE (TREE_VALUE (parm)) == TEMPLATE_DECL)
6720 argument_pack = cxx_make_type (TYPE_ARGUMENT_PACK);
6723 argument_pack = make_node (NONTYPE_ARGUMENT_PACK);
6724 TREE_TYPE (argument_pack)
6725 = tsubst (TREE_TYPE (TREE_VALUE (parm)), new_args, complain, in_decl);
6726 TREE_CONSTANT (argument_pack) = 1;
6729 SET_ARGUMENT_PACK_ARGS (argument_pack, packed_args);
6730 #ifdef ENABLE_CHECKING
6731 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (packed_args,
6732 TREE_VEC_LENGTH (packed_args));
6734 return argument_pack;
6737 /* Convert all template arguments to their appropriate types, and
6738 return a vector containing the innermost resulting template
6739 arguments. If any error occurs, return error_mark_node. Error and
6740 warning messages are issued under control of COMPLAIN.
6742 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6743 for arguments not specified in ARGS. Otherwise, if
6744 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6745 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6746 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6750 coerce_template_parms (tree parms,
6753 tsubst_flags_t complain,
6754 bool require_all_args,
6755 bool use_default_args)
6757 int nparms, nargs, parm_idx, arg_idx, lost = 0;
6760 tree new_inner_args;
6761 int saved_unevaluated_operand;
6762 int saved_inhibit_evaluation_warnings;
6764 /* When used as a boolean value, indicates whether this is a
6765 variadic template parameter list. Since it's an int, we can also
6766 subtract it from nparms to get the number of non-variadic
6769 int post_variadic_parms = 0;
6771 if (args == error_mark_node)
6772 return error_mark_node;
6774 nparms = TREE_VEC_LENGTH (parms);
6776 /* Determine if there are any parameter packs. */
6777 for (parm_idx = 0; parm_idx < nparms; ++parm_idx)
6779 tree tparm = TREE_VALUE (TREE_VEC_ELT (parms, parm_idx));
6781 ++post_variadic_parms;
6782 if (template_parameter_pack_p (tparm))
6786 inner_args = INNERMOST_TEMPLATE_ARGS (args);
6787 /* If there are no parameters that follow a parameter pack, we need to
6788 expand any argument packs so that we can deduce a parameter pack from
6789 some non-packed args followed by an argument pack, as in variadic85.C.
6790 If there are such parameters, we need to leave argument packs intact
6791 so the arguments are assigned properly. This can happen when dealing
6792 with a nested class inside a partial specialization of a class
6793 template, as in variadic92.C, or when deducing a template parameter pack
6794 from a sub-declarator, as in variadic114.C. */
6795 if (!post_variadic_parms)
6796 inner_args = expand_template_argument_pack (inner_args);
6798 nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
6799 if ((nargs > nparms && !variadic_p)
6800 || (nargs < nparms - variadic_p
6802 && (!use_default_args
6803 || (TREE_VEC_ELT (parms, nargs) != error_mark_node
6804 && !TREE_PURPOSE (TREE_VEC_ELT (parms, nargs))))))
6806 if (complain & tf_error)
6810 nparms -= variadic_p;
6811 error ("wrong number of template arguments "
6812 "(%d, should be %d or more)", nargs, nparms);
6815 error ("wrong number of template arguments "
6816 "(%d, should be %d)", nargs, nparms);
6819 error ("provided for %q+D", in_decl);
6822 return error_mark_node;
6825 /* We need to evaluate the template arguments, even though this
6826 template-id may be nested within a "sizeof". */
6827 saved_unevaluated_operand = cp_unevaluated_operand;
6828 cp_unevaluated_operand = 0;
6829 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
6830 c_inhibit_evaluation_warnings = 0;
6831 new_inner_args = make_tree_vec (nparms);
6832 new_args = add_outermost_template_args (args, new_inner_args);
6833 for (parm_idx = 0, arg_idx = 0; parm_idx < nparms; parm_idx++, arg_idx++)
6838 /* Get the Ith template parameter. */
6839 parm = TREE_VEC_ELT (parms, parm_idx);
6841 if (parm == error_mark_node)
6843 TREE_VEC_ELT (new_inner_args, arg_idx) = error_mark_node;
6847 /* Calculate the next argument. */
6848 if (arg_idx < nargs)
6849 arg = TREE_VEC_ELT (inner_args, arg_idx);
6853 if (template_parameter_pack_p (TREE_VALUE (parm))
6854 && !(arg && ARGUMENT_PACK_P (arg)))
6856 /* All remaining arguments will be placed in the
6857 template parameter pack PARM. */
6858 arg = coerce_template_parameter_pack (parms, parm_idx, args,
6859 inner_args, arg_idx,
6863 /* Store this argument. */
6864 if (arg == error_mark_node)
6866 TREE_VEC_ELT (new_inner_args, parm_idx) = arg;
6868 /* We are done with all of the arguments. */
6875 if (PACK_EXPANSION_P (arg))
6877 /* We don't know how many args we have yet, just
6878 use the unconverted ones for now. */
6879 new_inner_args = args;
6883 else if (require_all_args)
6885 /* There must be a default arg in this case. */
6886 arg = tsubst_template_arg (TREE_PURPOSE (parm), new_args,
6888 /* The position of the first default template argument,
6889 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6891 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args))
6892 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args, arg_idx);
6897 if (arg == error_mark_node)
6899 if (complain & tf_error)
6900 error ("template argument %d is invalid", arg_idx + 1);
6903 /* This only occurs if there was an error in the template
6904 parameter list itself (which we would already have
6905 reported) that we are trying to recover from, e.g., a class
6906 template with a parameter list such as
6907 template<typename..., typename>. */
6910 arg = convert_template_argument (TREE_VALUE (parm),
6911 arg, new_args, complain,
6914 if (arg == error_mark_node)
6916 TREE_VEC_ELT (new_inner_args, arg_idx) = arg;
6918 cp_unevaluated_operand = saved_unevaluated_operand;
6919 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
6922 return error_mark_node;
6924 #ifdef ENABLE_CHECKING
6925 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args))
6926 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args,
6927 TREE_VEC_LENGTH (new_inner_args));
6930 return new_inner_args;
6933 /* Returns 1 if template args OT and NT are equivalent. */
6936 template_args_equal (tree ot, tree nt)
6940 if (nt == NULL_TREE || ot == NULL_TREE)
6943 if (TREE_CODE (nt) == TREE_VEC)
6944 /* For member templates */
6945 return TREE_CODE (ot) == TREE_VEC && comp_template_args (ot, nt);
6946 else if (PACK_EXPANSION_P (ot))
6947 return (PACK_EXPANSION_P (nt)
6948 && template_args_equal (PACK_EXPANSION_PATTERN (ot),
6949 PACK_EXPANSION_PATTERN (nt))
6950 && template_args_equal (PACK_EXPANSION_EXTRA_ARGS (ot),
6951 PACK_EXPANSION_EXTRA_ARGS (nt)));
6952 else if (ARGUMENT_PACK_P (ot))
6957 if (!ARGUMENT_PACK_P (nt))
6960 opack = ARGUMENT_PACK_ARGS (ot);
6961 npack = ARGUMENT_PACK_ARGS (nt);
6962 len = TREE_VEC_LENGTH (opack);
6963 if (TREE_VEC_LENGTH (npack) != len)
6965 for (i = 0; i < len; ++i)
6966 if (!template_args_equal (TREE_VEC_ELT (opack, i),
6967 TREE_VEC_ELT (npack, i)))
6971 else if (ot && TREE_CODE (ot) == ARGUMENT_PACK_SELECT)
6973 /* We get here probably because we are in the middle of substituting
6974 into the pattern of a pack expansion. In that case the
6975 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
6976 interested in. So we want to use the initial pack argument for
6978 ot = ARGUMENT_PACK_SELECT_FROM_PACK (ot);
6979 if (nt && TREE_CODE (nt) == ARGUMENT_PACK_SELECT)
6980 nt = ARGUMENT_PACK_SELECT_FROM_PACK (nt);
6981 return template_args_equal (ot, nt);
6983 else if (TYPE_P (nt))
6984 return TYPE_P (ot) && same_type_p (ot, nt);
6985 else if (TREE_CODE (ot) == TREE_VEC || TYPE_P (ot))
6988 return cp_tree_equal (ot, nt);
6991 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
6992 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
6993 NEWARG_PTR with the offending arguments if they are non-NULL. */
6996 comp_template_args_with_info (tree oldargs, tree newargs,
6997 tree *oldarg_ptr, tree *newarg_ptr)
7001 if (oldargs == newargs)
7004 if (!oldargs || !newargs)
7007 if (TREE_VEC_LENGTH (oldargs) != TREE_VEC_LENGTH (newargs))
7010 for (i = 0; i < TREE_VEC_LENGTH (oldargs); ++i)
7012 tree nt = TREE_VEC_ELT (newargs, i);
7013 tree ot = TREE_VEC_ELT (oldargs, i);
7015 if (! template_args_equal (ot, nt))
7017 if (oldarg_ptr != NULL)
7019 if (newarg_ptr != NULL)
7027 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
7028 of template arguments. Returns 0 otherwise. */
7031 comp_template_args (tree oldargs, tree newargs)
7033 return comp_template_args_with_info (oldargs, newargs, NULL, NULL);
7037 add_pending_template (tree d)
7039 tree ti = (TYPE_P (d)
7040 ? CLASSTYPE_TEMPLATE_INFO (d)
7041 : DECL_TEMPLATE_INFO (d));
7042 struct pending_template *pt;
7045 if (TI_PENDING_TEMPLATE_FLAG (ti))
7048 /* We are called both from instantiate_decl, where we've already had a
7049 tinst_level pushed, and instantiate_template, where we haven't.
7051 level = !current_tinst_level || current_tinst_level->decl != d;
7054 push_tinst_level (d);
7056 pt = ggc_alloc_pending_template ();
7058 pt->tinst = current_tinst_level;
7059 if (last_pending_template)
7060 last_pending_template->next = pt;
7062 pending_templates = pt;
7064 last_pending_template = pt;
7066 TI_PENDING_TEMPLATE_FLAG (ti) = 1;
7073 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
7074 ARGLIST. Valid choices for FNS are given in the cp-tree.def
7075 documentation for TEMPLATE_ID_EXPR. */
7078 lookup_template_function (tree fns, tree arglist)
7082 if (fns == error_mark_node || arglist == error_mark_node)
7083 return error_mark_node;
7085 gcc_assert (!arglist || TREE_CODE (arglist) == TREE_VEC);
7087 if (!is_overloaded_fn (fns) && TREE_CODE (fns) != IDENTIFIER_NODE)
7089 error ("%q#D is not a function template", fns);
7090 return error_mark_node;
7093 if (BASELINK_P (fns))
7095 BASELINK_FUNCTIONS (fns) = build2 (TEMPLATE_ID_EXPR,
7097 BASELINK_FUNCTIONS (fns),
7102 type = TREE_TYPE (fns);
7103 if (TREE_CODE (fns) == OVERLOAD || !type)
7104 type = unknown_type_node;
7106 return build2 (TEMPLATE_ID_EXPR, type, fns, arglist);
7109 /* Within the scope of a template class S<T>, the name S gets bound
7110 (in build_self_reference) to a TYPE_DECL for the class, not a
7111 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
7112 or one of its enclosing classes, and that type is a template,
7113 return the associated TEMPLATE_DECL. Otherwise, the original
7116 Also handle the case when DECL is a TREE_LIST of ambiguous
7117 injected-class-names from different bases. */
7120 maybe_get_template_decl_from_type_decl (tree decl)
7122 if (decl == NULL_TREE)
7125 /* DR 176: A lookup that finds an injected-class-name (10.2
7126 [class.member.lookup]) can result in an ambiguity in certain cases
7127 (for example, if it is found in more than one base class). If all of
7128 the injected-class-names that are found refer to specializations of
7129 the same class template, and if the name is followed by a
7130 template-argument-list, the reference refers to the class template
7131 itself and not a specialization thereof, and is not ambiguous. */
7132 if (TREE_CODE (decl) == TREE_LIST)
7134 tree t, tmpl = NULL_TREE;
7135 for (t = decl; t; t = TREE_CHAIN (t))
7137 tree elt = maybe_get_template_decl_from_type_decl (TREE_VALUE (t));
7140 else if (tmpl != elt)
7143 if (tmpl && t == NULL_TREE)
7149 return (decl != NULL_TREE
7150 && DECL_SELF_REFERENCE_P (decl)
7151 && CLASSTYPE_TEMPLATE_INFO (TREE_TYPE (decl)))
7152 ? CLASSTYPE_TI_TEMPLATE (TREE_TYPE (decl)) : decl;
7155 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
7156 parameters, find the desired type.
7158 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
7160 IN_DECL, if non-NULL, is the template declaration we are trying to
7163 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
7164 the class we are looking up.
7166 Issue error and warning messages under control of COMPLAIN.
7168 If the template class is really a local class in a template
7169 function, then the FUNCTION_CONTEXT is the function in which it is
7172 ??? Note that this function is currently called *twice* for each
7173 template-id: the first time from the parser, while creating the
7174 incomplete type (finish_template_type), and the second type during the
7175 real instantiation (instantiate_template_class). This is surely something
7176 that we want to avoid. It also causes some problems with argument
7177 coercion (see convert_nontype_argument for more information on this). */
7180 lookup_template_class_1 (tree d1, tree arglist, tree in_decl, tree context,
7181 int entering_scope, tsubst_flags_t complain)
7183 tree templ = NULL_TREE, parmlist;
7190 if (TREE_CODE (d1) == IDENTIFIER_NODE)
7192 tree value = innermost_non_namespace_value (d1);
7193 if (value && DECL_TEMPLATE_TEMPLATE_PARM_P (value))
7198 push_decl_namespace (context);
7199 templ = lookup_name (d1);
7200 templ = maybe_get_template_decl_from_type_decl (templ);
7202 pop_decl_namespace ();
7205 context = DECL_CONTEXT (templ);
7207 else if (TREE_CODE (d1) == TYPE_DECL && MAYBE_CLASS_TYPE_P (TREE_TYPE (d1)))
7209 tree type = TREE_TYPE (d1);
7211 /* If we are declaring a constructor, say A<T>::A<T>, we will get
7212 an implicit typename for the second A. Deal with it. */
7213 if (TREE_CODE (type) == TYPENAME_TYPE && TREE_TYPE (type))
7214 type = TREE_TYPE (type);
7216 if (CLASSTYPE_TEMPLATE_INFO (type))
7218 templ = CLASSTYPE_TI_TEMPLATE (type);
7219 d1 = DECL_NAME (templ);
7222 else if (TREE_CODE (d1) == ENUMERAL_TYPE
7223 || (TYPE_P (d1) && MAYBE_CLASS_TYPE_P (d1)))
7225 templ = TYPE_TI_TEMPLATE (d1);
7226 d1 = DECL_NAME (templ);
7228 else if (TREE_CODE (d1) == TEMPLATE_DECL
7229 && DECL_TEMPLATE_RESULT (d1)
7230 && TREE_CODE (DECL_TEMPLATE_RESULT (d1)) == TYPE_DECL)
7233 d1 = DECL_NAME (templ);
7234 context = DECL_CONTEXT (templ);
7237 /* Issue an error message if we didn't find a template. */
7240 if (complain & tf_error)
7241 error ("%qT is not a template", d1);
7242 return error_mark_node;
7245 if (TREE_CODE (templ) != TEMPLATE_DECL
7246 /* Make sure it's a user visible template, if it was named by
7248 || ((complain & tf_user) && !DECL_TEMPLATE_PARM_P (templ)
7249 && !PRIMARY_TEMPLATE_P (templ)))
7251 if (complain & tf_error)
7253 error ("non-template type %qT used as a template", d1);
7255 error ("for template declaration %q+D", in_decl);
7257 return error_mark_node;
7260 complain &= ~tf_user;
7262 if (DECL_TEMPLATE_TEMPLATE_PARM_P (templ))
7264 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
7265 template arguments */
7271 parmlist = DECL_INNERMOST_TEMPLATE_PARMS (templ);
7273 /* Consider an example where a template template parameter declared as
7275 template <class T, class U = std::allocator<T> > class TT
7277 The template parameter level of T and U are one level larger than
7278 of TT. To proper process the default argument of U, say when an
7279 instantiation `TT<int>' is seen, we need to build the full
7280 arguments containing {int} as the innermost level. Outer levels,
7281 available when not appearing as default template argument, can be
7282 obtained from the arguments of the enclosing template.
7284 Suppose that TT is later substituted with std::vector. The above
7285 instantiation is `TT<int, std::allocator<T> >' with TT at
7286 level 1, and T at level 2, while the template arguments at level 1
7287 becomes {std::vector} and the inner level 2 is {int}. */
7289 outer = DECL_CONTEXT (templ);
7291 outer = TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (outer)));
7292 else if (current_template_parms)
7293 /* This is an argument of the current template, so we haven't set
7294 DECL_CONTEXT yet. */
7295 outer = current_template_args ();
7298 arglist = add_to_template_args (outer, arglist);
7300 arglist2 = coerce_template_parms (parmlist, arglist, templ,
7302 /*require_all_args=*/true,
7303 /*use_default_args=*/true);
7304 if (arglist2 == error_mark_node
7305 || (!uses_template_parms (arglist2)
7306 && check_instantiated_args (templ, arglist2, complain)))
7307 return error_mark_node;
7309 parm = bind_template_template_parm (TREE_TYPE (templ), arglist2);
7314 tree template_type = TREE_TYPE (templ);
7317 tree found = NULL_TREE;
7320 int is_dependent_type;
7321 int use_partial_inst_tmpl = false;
7323 if (template_type == error_mark_node)
7324 /* An error occured while building the template TEMPL, and a
7325 diagnostic has most certainly been emitted for that
7326 already. Let's propagate that error. */
7327 return error_mark_node;
7329 gen_tmpl = most_general_template (templ);
7330 parmlist = DECL_TEMPLATE_PARMS (gen_tmpl);
7331 parm_depth = TMPL_PARMS_DEPTH (parmlist);
7332 arg_depth = TMPL_ARGS_DEPTH (arglist);
7334 if (arg_depth == 1 && parm_depth > 1)
7336 /* We've been given an incomplete set of template arguments.
7339 template <class T> struct S1 {
7340 template <class U> struct S2 {};
7341 template <class U> struct S2<U*> {};
7344 we will be called with an ARGLIST of `U*', but the
7345 TEMPLATE will be `template <class T> template
7346 <class U> struct S1<T>::S2'. We must fill in the missing
7349 = add_outermost_template_args (TYPE_TI_ARGS (TREE_TYPE (templ)),
7351 arg_depth = TMPL_ARGS_DEPTH (arglist);
7354 /* Now we should have enough arguments. */
7355 gcc_assert (parm_depth == arg_depth);
7357 /* From here on, we're only interested in the most general
7360 /* Calculate the BOUND_ARGS. These will be the args that are
7361 actually tsubst'd into the definition to create the
7365 /* We have multiple levels of arguments to coerce, at once. */
7367 int saved_depth = TMPL_ARGS_DEPTH (arglist);
7369 tree bound_args = make_tree_vec (parm_depth);
7371 for (i = saved_depth,
7372 t = DECL_TEMPLATE_PARMS (gen_tmpl);
7373 i > 0 && t != NULL_TREE;
7374 --i, t = TREE_CHAIN (t))
7377 if (i == saved_depth)
7378 a = coerce_template_parms (TREE_VALUE (t),
7381 /*require_all_args=*/true,
7382 /*use_default_args=*/true);
7384 /* Outer levels should have already been coerced. */
7385 a = TMPL_ARGS_LEVEL (arglist, i);
7387 /* Don't process further if one of the levels fails. */
7388 if (a == error_mark_node)
7390 /* Restore the ARGLIST to its full size. */
7391 TREE_VEC_LENGTH (arglist) = saved_depth;
7392 return error_mark_node;
7395 SET_TMPL_ARGS_LEVEL (bound_args, i, a);
7397 /* We temporarily reduce the length of the ARGLIST so
7398 that coerce_template_parms will see only the arguments
7399 corresponding to the template parameters it is
7401 TREE_VEC_LENGTH (arglist)--;
7404 /* Restore the ARGLIST to its full size. */
7405 TREE_VEC_LENGTH (arglist) = saved_depth;
7407 arglist = bound_args;
7411 = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parmlist),
7412 INNERMOST_TEMPLATE_ARGS (arglist),
7415 /*require_all_args=*/true,
7416 /*use_default_args=*/true);
7418 if (arglist == error_mark_node)
7419 /* We were unable to bind the arguments. */
7420 return error_mark_node;
7422 /* In the scope of a template class, explicit references to the
7423 template class refer to the type of the template, not any
7424 instantiation of it. For example, in:
7426 template <class T> class C { void f(C<T>); }
7428 the `C<T>' is just the same as `C'. Outside of the
7429 class, however, such a reference is an instantiation. */
7431 || !PRIMARY_TEMPLATE_P (gen_tmpl)
7432 || currently_open_class (template_type))
7433 /* comp_template_args is expensive, check it last. */
7434 && comp_template_args (TYPE_TI_ARGS (template_type),
7436 return template_type;
7438 /* If we already have this specialization, return it. */
7439 elt.tmpl = gen_tmpl;
7441 hash = hash_specialization (&elt);
7442 entry = (spec_entry *) htab_find_with_hash (type_specializations,
7448 is_dependent_type = uses_template_parms (arglist);
7450 /* If the deduced arguments are invalid, then the binding
7452 if (!is_dependent_type
7453 && check_instantiated_args (gen_tmpl,
7454 INNERMOST_TEMPLATE_ARGS (arglist),
7456 return error_mark_node;
7458 if (!is_dependent_type
7459 && !PRIMARY_TEMPLATE_P (gen_tmpl)
7460 && !LAMBDA_TYPE_P (TREE_TYPE (gen_tmpl))
7461 && TREE_CODE (CP_DECL_CONTEXT (gen_tmpl)) == NAMESPACE_DECL)
7463 found = xref_tag_from_type (TREE_TYPE (gen_tmpl),
7464 DECL_NAME (gen_tmpl),
7465 /*tag_scope=*/ts_global);
7469 context = tsubst (DECL_CONTEXT (gen_tmpl), arglist,
7471 if (context == error_mark_node)
7472 return error_mark_node;
7475 context = global_namespace;
7477 /* Create the type. */
7478 if (TREE_CODE (template_type) == ENUMERAL_TYPE)
7480 if (!is_dependent_type)
7482 set_current_access_from_decl (TYPE_NAME (template_type));
7483 t = start_enum (TYPE_IDENTIFIER (template_type), NULL_TREE,
7484 tsubst (ENUM_UNDERLYING_TYPE (template_type),
7485 arglist, complain, in_decl),
7486 SCOPED_ENUM_P (template_type), NULL);
7490 /* We don't want to call start_enum for this type, since
7491 the values for the enumeration constants may involve
7492 template parameters. And, no one should be interested
7493 in the enumeration constants for such a type. */
7494 t = cxx_make_type (ENUMERAL_TYPE);
7495 SET_SCOPED_ENUM_P (t, SCOPED_ENUM_P (template_type));
7497 SET_OPAQUE_ENUM_P (t, OPAQUE_ENUM_P (template_type));
7498 ENUM_FIXED_UNDERLYING_TYPE_P (t)
7499 = ENUM_FIXED_UNDERLYING_TYPE_P (template_type);
7501 else if (DECL_ALIAS_TEMPLATE_P (gen_tmpl))
7503 /* The user referred to a specialization of an alias
7504 template represented by GEN_TMPL.
7506 [temp.alias]/2 says:
7508 When a template-id refers to the specialization of an
7509 alias template, it is equivalent to the associated
7510 type obtained by substitution of its
7511 template-arguments for the template-parameters in the
7512 type-id of the alias template. */
7514 t = tsubst (TREE_TYPE (gen_tmpl), arglist, complain, in_decl);
7515 /* Note that the call above (by indirectly calling
7516 register_specialization in tsubst_decl) registers the
7517 TYPE_DECL representing the specialization of the alias
7518 template. So next time someone substitutes ARGLIST for
7519 the template parms into the alias template (GEN_TMPL),
7520 she'll get that TYPE_DECL back. */
7522 if (t == error_mark_node)
7525 else if (CLASS_TYPE_P (template_type))
7527 t = make_class_type (TREE_CODE (template_type));
7528 CLASSTYPE_DECLARED_CLASS (t)
7529 = CLASSTYPE_DECLARED_CLASS (template_type);
7530 SET_CLASSTYPE_IMPLICIT_INSTANTIATION (t);
7531 TYPE_FOR_JAVA (t) = TYPE_FOR_JAVA (template_type);
7533 /* A local class. Make sure the decl gets registered properly. */
7534 if (context == current_function_decl)
7535 pushtag (DECL_NAME (gen_tmpl), t, /*tag_scope=*/ts_current);
7537 if (comp_template_args (CLASSTYPE_TI_ARGS (template_type), arglist))
7538 /* This instantiation is another name for the primary
7539 template type. Set the TYPE_CANONICAL field
7541 TYPE_CANONICAL (t) = template_type;
7542 else if (any_template_arguments_need_structural_equality_p (arglist))
7543 /* Some of the template arguments require structural
7544 equality testing, so this template class requires
7545 structural equality testing. */
7546 SET_TYPE_STRUCTURAL_EQUALITY (t);
7551 /* If we called start_enum or pushtag above, this information
7552 will already be set up. */
7555 TYPE_CONTEXT (t) = FROB_CONTEXT (context);
7557 type_decl = create_implicit_typedef (DECL_NAME (gen_tmpl), t);
7558 DECL_CONTEXT (type_decl) = TYPE_CONTEXT (t);
7559 DECL_SOURCE_LOCATION (type_decl)
7560 = DECL_SOURCE_LOCATION (TYPE_STUB_DECL (template_type));
7563 type_decl = TYPE_NAME (t);
7565 if (CLASS_TYPE_P (template_type))
7567 TREE_PRIVATE (type_decl)
7568 = TREE_PRIVATE (TYPE_STUB_DECL (template_type));
7569 TREE_PROTECTED (type_decl)
7570 = TREE_PROTECTED (TYPE_STUB_DECL (template_type));
7571 if (CLASSTYPE_VISIBILITY_SPECIFIED (template_type))
7573 DECL_VISIBILITY_SPECIFIED (type_decl) = 1;
7574 DECL_VISIBILITY (type_decl) = CLASSTYPE_VISIBILITY (template_type);
7578 /* Let's consider the explicit specialization of a member
7579 of a class template specialization that is implicitely instantiated,
7584 template<class U> struct M {}; //#0
7589 struct S<int>::M<char> //#1
7593 [temp.expl.spec]/4 says this is valid.
7595 In this case, when we write:
7598 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7601 When we encounter #1, we want to store the partial instantiation
7602 of M (template<class T> S<int>::M<T>) in it's CLASSTYPE_TI_TEMPLATE.
7604 For all cases other than this "explicit specialization of member of a
7605 class template", we just want to store the most general template into
7606 the CLASSTYPE_TI_TEMPLATE of M.
7608 This case of "explicit specialization of member of a class template"
7610 1/ the enclosing class is an instantiation of, and therefore not
7611 the same as, the context of the most general template, and
7612 2/ we aren't looking at the partial instantiation itself, i.e.
7613 the innermost arguments are not the same as the innermost parms of
7614 the most general template.
7616 So it's only when 1/ and 2/ happens that we want to use the partial
7617 instantiation of the member template in lieu of its most general
7620 if (PRIMARY_TEMPLATE_P (gen_tmpl)
7621 && TMPL_ARGS_HAVE_MULTIPLE_LEVELS (arglist)
7622 /* the enclosing class must be an instantiation... */
7623 && CLASS_TYPE_P (context)
7624 && !same_type_p (context, DECL_CONTEXT (gen_tmpl)))
7626 tree partial_inst_args;
7627 TREE_VEC_LENGTH (arglist)--;
7628 ++processing_template_decl;
7630 tsubst (INNERMOST_TEMPLATE_ARGS
7631 (TYPE_TI_ARGS (TREE_TYPE (gen_tmpl))),
7632 arglist, complain, NULL_TREE);
7633 --processing_template_decl;
7634 TREE_VEC_LENGTH (arglist)++;
7635 use_partial_inst_tmpl =
7636 /*...and we must not be looking at the partial instantiation
7638 !comp_template_args (INNERMOST_TEMPLATE_ARGS (arglist),
7642 if (!use_partial_inst_tmpl)
7643 /* This case is easy; there are no member templates involved. */
7647 /* This is a full instantiation of a member template. Find
7648 the partial instantiation of which this is an instance. */
7650 /* Temporarily reduce by one the number of levels in the ARGLIST
7651 so as to avoid comparing the last set of arguments. */
7652 TREE_VEC_LENGTH (arglist)--;
7653 found = tsubst (gen_tmpl, arglist, complain, NULL_TREE);
7654 TREE_VEC_LENGTH (arglist)++;
7655 /* FOUND is either a proper class type, or an alias
7656 template specialization. In the later case, it's a
7657 TYPE_DECL, resulting from the substituting of arguments
7658 for parameters in the TYPE_DECL of the alias template
7659 done earlier. So be careful while getting the template
7661 found = TREE_CODE (found) == TYPE_DECL
7662 ? TYPE_TI_TEMPLATE (TREE_TYPE (found))
7663 : CLASSTYPE_TI_TEMPLATE (found);
7666 SET_TYPE_TEMPLATE_INFO (t, build_template_info (found, arglist));
7669 slot = htab_find_slot_with_hash (type_specializations,
7670 &elt, hash, INSERT);
7671 entry = ggc_alloc_spec_entry ();
7675 /* Note this use of the partial instantiation so we can check it
7676 later in maybe_process_partial_specialization. */
7677 DECL_TEMPLATE_INSTANTIATIONS (templ)
7678 = tree_cons (arglist, t,
7679 DECL_TEMPLATE_INSTANTIATIONS (templ));
7681 if (TREE_CODE (t) == ENUMERAL_TYPE && !is_dependent_type)
7682 /* Now that the type has been registered on the instantiations
7683 list, we set up the enumerators. Because the enumeration
7684 constants may involve the enumeration type itself, we make
7685 sure to register the type first, and then create the
7686 constants. That way, doing tsubst_expr for the enumeration
7687 constants won't result in recursive calls here; we'll find
7688 the instantiation and exit above. */
7689 tsubst_enum (template_type, t, arglist);
7691 if (CLASS_TYPE_P (template_type) && is_dependent_type)
7692 /* If the type makes use of template parameters, the
7693 code that generates debugging information will crash. */
7694 DECL_IGNORED_P (TYPE_STUB_DECL (t)) = 1;
7696 /* Possibly limit visibility based on template args. */
7697 TREE_PUBLIC (type_decl) = 1;
7698 determine_visibility (type_decl);
7704 /* Wrapper for lookup_template_class_1. */
7707 lookup_template_class (tree d1, tree arglist, tree in_decl, tree context,
7708 int entering_scope, tsubst_flags_t complain)
7711 timevar_push (TV_TEMPLATE_INST);
7712 ret = lookup_template_class_1 (d1, arglist, in_decl, context,
7713 entering_scope, complain);
7714 timevar_pop (TV_TEMPLATE_INST);
7722 /* True when we should also visit template parameters that occur in
7723 non-deduced contexts. */
7724 bool include_nondeduced_p;
7725 struct pointer_set_t *visited;
7728 /* Called from for_each_template_parm via walk_tree. */
7731 for_each_template_parm_r (tree *tp, int *walk_subtrees, void *d)
7734 struct pair_fn_data *pfd = (struct pair_fn_data *) d;
7735 tree_fn_t fn = pfd->fn;
7736 void *data = pfd->data;
7739 && (pfd->include_nondeduced_p || TREE_CODE (t) != TYPENAME_TYPE)
7740 && for_each_template_parm (TYPE_CONTEXT (t), fn, data, pfd->visited,
7741 pfd->include_nondeduced_p))
7742 return error_mark_node;
7744 switch (TREE_CODE (t))
7747 if (TYPE_PTRMEMFUNC_P (t))
7753 if (!TYPE_TEMPLATE_INFO (t))
7755 else if (for_each_template_parm (TI_ARGS (TYPE_TEMPLATE_INFO (t)),
7756 fn, data, pfd->visited,
7757 pfd->include_nondeduced_p))
7758 return error_mark_node;
7762 if (for_each_template_parm (TYPE_MIN_VALUE (t),
7763 fn, data, pfd->visited,
7764 pfd->include_nondeduced_p)
7765 || for_each_template_parm (TYPE_MAX_VALUE (t),
7766 fn, data, pfd->visited,
7767 pfd->include_nondeduced_p))
7768 return error_mark_node;
7772 /* Since we're not going to walk subtrees, we have to do this
7774 if (for_each_template_parm (TYPE_METHOD_BASETYPE (t), fn, data,
7775 pfd->visited, pfd->include_nondeduced_p))
7776 return error_mark_node;
7780 /* Check the return type. */
7781 if (for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
7782 pfd->include_nondeduced_p))
7783 return error_mark_node;
7785 /* Check the parameter types. Since default arguments are not
7786 instantiated until they are needed, the TYPE_ARG_TYPES may
7787 contain expressions that involve template parameters. But,
7788 no-one should be looking at them yet. And, once they're
7789 instantiated, they don't contain template parameters, so
7790 there's no point in looking at them then, either. */
7794 for (parm = TYPE_ARG_TYPES (t); parm; parm = TREE_CHAIN (parm))
7795 if (for_each_template_parm (TREE_VALUE (parm), fn, data,
7796 pfd->visited, pfd->include_nondeduced_p))
7797 return error_mark_node;
7799 /* Since we've already handled the TYPE_ARG_TYPES, we don't
7800 want walk_tree walking into them itself. */
7806 case UNDERLYING_TYPE:
7807 if (pfd->include_nondeduced_p
7808 && for_each_template_parm (TYPE_FIELDS (t), fn, data,
7810 pfd->include_nondeduced_p))
7811 return error_mark_node;
7816 if (DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t)
7817 && for_each_template_parm (DECL_TI_ARGS (t), fn, data,
7818 pfd->visited, pfd->include_nondeduced_p))
7819 return error_mark_node;
7824 if (TREE_CODE (t) == CONST_DECL && DECL_TEMPLATE_PARM_P (t)
7825 && for_each_template_parm (DECL_INITIAL (t), fn, data,
7826 pfd->visited, pfd->include_nondeduced_p))
7827 return error_mark_node;
7828 if (DECL_CONTEXT (t)
7829 && pfd->include_nondeduced_p
7830 && for_each_template_parm (DECL_CONTEXT (t), fn, data,
7831 pfd->visited, pfd->include_nondeduced_p))
7832 return error_mark_node;
7835 case BOUND_TEMPLATE_TEMPLATE_PARM:
7836 /* Record template parameters such as `T' inside `TT<T>'. */
7837 if (for_each_template_parm (TYPE_TI_ARGS (t), fn, data, pfd->visited,
7838 pfd->include_nondeduced_p))
7839 return error_mark_node;
7842 case TEMPLATE_TEMPLATE_PARM:
7843 case TEMPLATE_TYPE_PARM:
7844 case TEMPLATE_PARM_INDEX:
7845 if (fn && (*fn)(t, data))
7846 return error_mark_node;
7848 return error_mark_node;
7852 /* A template template parameter is encountered. */
7853 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t)
7854 && for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
7855 pfd->include_nondeduced_p))
7856 return error_mark_node;
7858 /* Already substituted template template parameter */
7864 || for_each_template_parm (TYPENAME_TYPE_FULLNAME (t), fn,
7866 pfd->include_nondeduced_p))
7867 return error_mark_node;
7871 if (TREE_TYPE (t) && TYPE_PTRMEMFUNC_P (TREE_TYPE (t))
7872 && pfd->include_nondeduced_p
7873 && for_each_template_parm (TYPE_PTRMEMFUNC_FN_TYPE
7874 (TREE_TYPE (t)), fn, data,
7875 pfd->visited, pfd->include_nondeduced_p))
7876 return error_mark_node;
7881 /* If there's no type, then this thing must be some expression
7882 involving template parameters. */
7883 if (!fn && !TREE_TYPE (t))
7884 return error_mark_node;
7889 case IMPLICIT_CONV_EXPR:
7890 case REINTERPRET_CAST_EXPR:
7891 case CONST_CAST_EXPR:
7892 case STATIC_CAST_EXPR:
7893 case DYNAMIC_CAST_EXPR:
7897 case PSEUDO_DTOR_EXPR:
7899 return error_mark_node;
7906 /* We didn't find any template parameters we liked. */
7910 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
7911 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
7912 call FN with the parameter and the DATA.
7913 If FN returns nonzero, the iteration is terminated, and
7914 for_each_template_parm returns 1. Otherwise, the iteration
7915 continues. If FN never returns a nonzero value, the value
7916 returned by for_each_template_parm is 0. If FN is NULL, it is
7917 considered to be the function which always returns 1.
7919 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
7920 parameters that occur in non-deduced contexts. When false, only
7921 visits those template parameters that can be deduced. */
7924 for_each_template_parm (tree t, tree_fn_t fn, void* data,
7925 struct pointer_set_t *visited,
7926 bool include_nondeduced_p)
7928 struct pair_fn_data pfd;
7934 pfd.include_nondeduced_p = include_nondeduced_p;
7936 /* Walk the tree. (Conceptually, we would like to walk without
7937 duplicates, but for_each_template_parm_r recursively calls
7938 for_each_template_parm, so we would need to reorganize a fair
7939 bit to use walk_tree_without_duplicates, so we keep our own
7942 pfd.visited = visited;
7944 pfd.visited = pointer_set_create ();
7945 result = cp_walk_tree (&t,
7946 for_each_template_parm_r,
7948 pfd.visited) != NULL_TREE;
7953 pointer_set_destroy (pfd.visited);
7960 /* Returns true if T depends on any template parameter. */
7963 uses_template_parms (tree t)
7966 int saved_processing_template_decl;
7968 saved_processing_template_decl = processing_template_decl;
7969 if (!saved_processing_template_decl)
7970 processing_template_decl = 1;
7972 dependent_p = dependent_type_p (t);
7973 else if (TREE_CODE (t) == TREE_VEC)
7974 dependent_p = any_dependent_template_arguments_p (t);
7975 else if (TREE_CODE (t) == TREE_LIST)
7976 dependent_p = (uses_template_parms (TREE_VALUE (t))
7977 || uses_template_parms (TREE_CHAIN (t)));
7978 else if (TREE_CODE (t) == TYPE_DECL)
7979 dependent_p = dependent_type_p (TREE_TYPE (t));
7982 || TREE_CODE (t) == TEMPLATE_PARM_INDEX
7983 || TREE_CODE (t) == OVERLOAD
7985 || TREE_CODE (t) == IDENTIFIER_NODE
7986 || TREE_CODE (t) == TRAIT_EXPR
7987 || TREE_CODE (t) == CONSTRUCTOR
7988 || CONSTANT_CLASS_P (t))
7989 dependent_p = (type_dependent_expression_p (t)
7990 || value_dependent_expression_p (t));
7993 gcc_assert (t == error_mark_node);
7994 dependent_p = false;
7997 processing_template_decl = saved_processing_template_decl;
8002 /* Returns true if T depends on any template parameter with level LEVEL. */
8005 uses_template_parms_level (tree t, int level)
8007 return for_each_template_parm (t, template_parm_this_level_p, &level, NULL,
8008 /*include_nondeduced_p=*/true);
8011 /* Returns TRUE iff INST is an instantiation we don't need to do in an
8012 ill-formed translation unit, i.e. a variable or function that isn't
8013 usable in a constant expression. */
8016 neglectable_inst_p (tree d)
8019 && !(TREE_CODE (d) == FUNCTION_DECL ? DECL_DECLARED_CONSTEXPR_P (d)
8020 : decl_maybe_constant_var_p (d)));
8023 /* Returns TRUE iff we should refuse to instantiate DECL because it's
8024 neglectable and instantiated from within an erroneous instantiation. */
8027 limit_bad_template_recursion (tree decl)
8029 struct tinst_level *lev = current_tinst_level;
8030 int errs = errorcount + sorrycount;
8031 if (lev == NULL || errs == 0 || !neglectable_inst_p (decl))
8034 for (; lev; lev = lev->next)
8035 if (neglectable_inst_p (lev->decl))
8038 return (lev && errs > lev->errors);
8041 static int tinst_depth;
8042 extern int max_tinst_depth;
8043 #ifdef GATHER_STATISTICS
8046 static GTY(()) struct tinst_level *last_error_tinst_level;
8048 /* We're starting to instantiate D; record the template instantiation context
8049 for diagnostics and to restore it later. */
8052 push_tinst_level (tree d)
8054 struct tinst_level *new_level;
8056 if (tinst_depth >= max_tinst_depth)
8058 last_error_tinst_level = current_tinst_level;
8059 if (TREE_CODE (d) == TREE_LIST)
8060 error ("template instantiation depth exceeds maximum of %d (use "
8061 "-ftemplate-depth= to increase the maximum) substituting %qS",
8062 max_tinst_depth, d);
8064 error ("template instantiation depth exceeds maximum of %d (use "
8065 "-ftemplate-depth= to increase the maximum) instantiating %qD",
8066 max_tinst_depth, d);
8068 print_instantiation_context ();
8073 /* If the current instantiation caused problems, don't let it instantiate
8074 anything else. Do allow deduction substitution and decls usable in
8075 constant expressions. */
8076 if (limit_bad_template_recursion (d))
8079 new_level = ggc_alloc_tinst_level ();
8080 new_level->decl = d;
8081 new_level->locus = input_location;
8082 new_level->errors = errorcount+sorrycount;
8083 new_level->in_system_header_p = in_system_header;
8084 new_level->next = current_tinst_level;
8085 current_tinst_level = new_level;
8088 #ifdef GATHER_STATISTICS
8089 if (tinst_depth > depth_reached)
8090 depth_reached = tinst_depth;
8096 /* We're done instantiating this template; return to the instantiation
8100 pop_tinst_level (void)
8102 /* Restore the filename and line number stashed away when we started
8103 this instantiation. */
8104 input_location = current_tinst_level->locus;
8105 current_tinst_level = current_tinst_level->next;
8109 /* We're instantiating a deferred template; restore the template
8110 instantiation context in which the instantiation was requested, which
8111 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
8114 reopen_tinst_level (struct tinst_level *level)
8116 struct tinst_level *t;
8119 for (t = level; t; t = t->next)
8122 current_tinst_level = level;
8124 if (current_tinst_level)
8125 current_tinst_level->errors = errorcount+sorrycount;
8129 /* Returns the TINST_LEVEL which gives the original instantiation
8132 struct tinst_level *
8133 outermost_tinst_level (void)
8135 struct tinst_level *level = current_tinst_level;
8138 level = level->next;
8142 /* Returns TRUE if PARM is a parameter of the template TEMPL. */
8145 parameter_of_template_p (tree parm, tree templ)
8150 if (!parm || !templ)
8153 gcc_assert (DECL_TEMPLATE_PARM_P (parm));
8154 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
8156 parms = DECL_TEMPLATE_PARMS (templ);
8157 parms = INNERMOST_TEMPLATE_PARMS (parms);
8159 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
8161 tree p = TREE_VALUE (TREE_VEC_ELT (parms, i));
8162 if (p == error_mark_node)
8166 || (DECL_INITIAL (parm)
8167 && DECL_INITIAL (parm) == DECL_INITIAL (p)))
8174 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
8175 vector of template arguments, as for tsubst.
8177 Returns an appropriate tsubst'd friend declaration. */
8180 tsubst_friend_function (tree decl, tree args)
8184 if (TREE_CODE (decl) == FUNCTION_DECL
8185 && DECL_TEMPLATE_INSTANTIATION (decl)
8186 && TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
8187 /* This was a friend declared with an explicit template
8188 argument list, e.g.:
8192 to indicate that f was a template instantiation, not a new
8193 function declaration. Now, we have to figure out what
8194 instantiation of what template. */
8196 tree template_id, arglist, fns;
8199 tree ns = decl_namespace_context (TYPE_MAIN_DECL (current_class_type));
8201 /* Friend functions are looked up in the containing namespace scope.
8202 We must enter that scope, to avoid finding member functions of the
8203 current class with same name. */
8204 push_nested_namespace (ns);
8205 fns = tsubst_expr (DECL_TI_TEMPLATE (decl), args,
8206 tf_warning_or_error, NULL_TREE,
8207 /*integral_constant_expression_p=*/false);
8208 pop_nested_namespace (ns);
8209 arglist = tsubst (DECL_TI_ARGS (decl), args,
8210 tf_warning_or_error, NULL_TREE);
8211 template_id = lookup_template_function (fns, arglist);
8213 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
8214 tmpl = determine_specialization (template_id, new_friend,
8216 /*need_member_template=*/0,
8217 TREE_VEC_LENGTH (args),
8219 return instantiate_template (tmpl, new_args, tf_error);
8222 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
8224 /* The NEW_FRIEND will look like an instantiation, to the
8225 compiler, but is not an instantiation from the point of view of
8226 the language. For example, we might have had:
8228 template <class T> struct S {
8229 template <class U> friend void f(T, U);
8232 Then, in S<int>, template <class U> void f(int, U) is not an
8233 instantiation of anything. */
8234 if (new_friend == error_mark_node)
8235 return error_mark_node;
8237 DECL_USE_TEMPLATE (new_friend) = 0;
8238 if (TREE_CODE (decl) == TEMPLATE_DECL)
8240 DECL_USE_TEMPLATE (DECL_TEMPLATE_RESULT (new_friend)) = 0;
8241 DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (new_friend))
8242 = DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (decl));
8245 /* The mangled name for the NEW_FRIEND is incorrect. The function
8246 is not a template instantiation and should not be mangled like
8247 one. Therefore, we forget the mangling here; we'll recompute it
8248 later if we need it. */
8249 if (TREE_CODE (new_friend) != TEMPLATE_DECL)
8251 SET_DECL_RTL (new_friend, NULL);
8252 SET_DECL_ASSEMBLER_NAME (new_friend, NULL_TREE);
8255 if (DECL_NAMESPACE_SCOPE_P (new_friend))
8258 tree new_friend_template_info;
8259 tree new_friend_result_template_info;
8261 int new_friend_is_defn;
8263 /* We must save some information from NEW_FRIEND before calling
8264 duplicate decls since that function will free NEW_FRIEND if
8266 new_friend_template_info = DECL_TEMPLATE_INFO (new_friend);
8267 new_friend_is_defn =
8268 (DECL_INITIAL (DECL_TEMPLATE_RESULT
8269 (template_for_substitution (new_friend)))
8271 if (TREE_CODE (new_friend) == TEMPLATE_DECL)
8273 /* This declaration is a `primary' template. */
8274 DECL_PRIMARY_TEMPLATE (new_friend) = new_friend;
8276 new_friend_result_template_info
8277 = DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (new_friend));
8280 new_friend_result_template_info = NULL_TREE;
8282 /* Make the init_value nonzero so pushdecl knows this is a defn. */
8283 if (new_friend_is_defn)
8284 DECL_INITIAL (new_friend) = error_mark_node;
8286 /* Inside pushdecl_namespace_level, we will push into the
8287 current namespace. However, the friend function should go
8288 into the namespace of the template. */
8289 ns = decl_namespace_context (new_friend);
8290 push_nested_namespace (ns);
8291 old_decl = pushdecl_namespace_level (new_friend, /*is_friend=*/true);
8292 pop_nested_namespace (ns);
8294 if (old_decl == error_mark_node)
8295 return error_mark_node;
8297 if (old_decl != new_friend)
8299 /* This new friend declaration matched an existing
8300 declaration. For example, given:
8302 template <class T> void f(T);
8303 template <class U> class C {
8304 template <class T> friend void f(T) {}
8307 the friend declaration actually provides the definition
8308 of `f', once C has been instantiated for some type. So,
8309 old_decl will be the out-of-class template declaration,
8310 while new_friend is the in-class definition.
8312 But, if `f' was called before this point, the
8313 instantiation of `f' will have DECL_TI_ARGS corresponding
8314 to `T' but not to `U', references to which might appear
8315 in the definition of `f'. Previously, the most general
8316 template for an instantiation of `f' was the out-of-class
8317 version; now it is the in-class version. Therefore, we
8318 run through all specialization of `f', adding to their
8319 DECL_TI_ARGS appropriately. In particular, they need a
8320 new set of outer arguments, corresponding to the
8321 arguments for this class instantiation.
8323 The same situation can arise with something like this:
8326 template <class T> class C {
8330 when `C<int>' is instantiated. Now, `f(int)' is defined
8333 if (!new_friend_is_defn)
8334 /* On the other hand, if the in-class declaration does
8335 *not* provide a definition, then we don't want to alter
8336 existing definitions. We can just leave everything
8341 tree new_template = TI_TEMPLATE (new_friend_template_info);
8342 tree new_args = TI_ARGS (new_friend_template_info);
8344 /* Overwrite whatever template info was there before, if
8345 any, with the new template information pertaining to
8347 DECL_TEMPLATE_INFO (old_decl) = new_friend_template_info;
8349 if (TREE_CODE (old_decl) != TEMPLATE_DECL)
8351 /* We should have called reregister_specialization in
8353 gcc_assert (retrieve_specialization (new_template,
8357 /* Instantiate it if the global has already been used. */
8358 if (DECL_ODR_USED (old_decl))
8359 instantiate_decl (old_decl, /*defer_ok=*/true,
8360 /*expl_inst_class_mem_p=*/false);
8366 /* Indicate that the old function template is a partial
8368 DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (old_decl))
8369 = new_friend_result_template_info;
8371 gcc_assert (new_template
8372 == most_general_template (new_template));
8373 gcc_assert (new_template != old_decl);
8375 /* Reassign any specializations already in the hash table
8376 to the new more general template, and add the
8377 additional template args. */
8378 for (t = DECL_TEMPLATE_INSTANTIATIONS (old_decl);
8382 tree spec = TREE_VALUE (t);
8385 elt.tmpl = old_decl;
8386 elt.args = DECL_TI_ARGS (spec);
8387 elt.spec = NULL_TREE;
8389 htab_remove_elt (decl_specializations, &elt);
8392 = add_outermost_template_args (new_args,
8393 DECL_TI_ARGS (spec));
8395 register_specialization
8396 (spec, new_template, DECL_TI_ARGS (spec), true, 0);
8399 DECL_TEMPLATE_INSTANTIATIONS (old_decl) = NULL_TREE;
8403 /* The information from NEW_FRIEND has been merged into OLD_DECL
8404 by duplicate_decls. */
8405 new_friend = old_decl;
8410 tree context = DECL_CONTEXT (new_friend);
8414 template <class T> class C {
8415 template <class U> friend void C1<U>::f (); // case 1
8416 friend void C2<T>::f (); // case 2
8418 we only need to make sure CONTEXT is a complete type for
8419 case 2. To distinguish between the two cases, we note that
8420 CONTEXT of case 1 remains dependent type after tsubst while
8421 this isn't true for case 2. */
8422 ++processing_template_decl;
8423 dependent_p = dependent_type_p (context);
8424 --processing_template_decl;
8427 && !complete_type_or_else (context, NULL_TREE))
8428 return error_mark_node;
8430 if (COMPLETE_TYPE_P (context))
8432 /* Check to see that the declaration is really present, and,
8433 possibly obtain an improved declaration. */
8434 tree fn = check_classfn (context,
8435 new_friend, NULL_TREE);
8445 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
8446 template arguments, as for tsubst.
8448 Returns an appropriate tsubst'd friend type or error_mark_node on
8452 tsubst_friend_class (tree friend_tmpl, tree args)
8458 context = CP_DECL_CONTEXT (friend_tmpl);
8460 if (context != global_namespace)
8462 if (TREE_CODE (context) == NAMESPACE_DECL)
8463 push_nested_namespace (context);
8465 push_nested_class (tsubst (context, args, tf_none, NULL_TREE));
8468 /* Look for a class template declaration. We look for hidden names
8469 because two friend declarations of the same template are the
8470 same. For example, in:
8473 template <typename> friend class F;
8475 template <typename> struct B {
8476 template <typename> friend class F;
8479 both F templates are the same. */
8480 tmpl = lookup_name_real (DECL_NAME (friend_tmpl), 0, 0,
8481 /*block_p=*/true, 0,
8482 LOOKUP_COMPLAIN | LOOKUP_HIDDEN);
8484 /* But, if we don't find one, it might be because we're in a
8485 situation like this:
8493 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
8494 for `S<int>', not the TEMPLATE_DECL. */
8495 if (!tmpl || !DECL_CLASS_TEMPLATE_P (tmpl))
8497 tmpl = lookup_name_prefer_type (DECL_NAME (friend_tmpl), 1);
8498 tmpl = maybe_get_template_decl_from_type_decl (tmpl);
8501 if (tmpl && DECL_CLASS_TEMPLATE_P (tmpl))
8503 /* The friend template has already been declared. Just
8504 check to see that the declarations match, and install any new
8505 default parameters. We must tsubst the default parameters,
8506 of course. We only need the innermost template parameters
8507 because that is all that redeclare_class_template will look
8509 if (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (friend_tmpl))
8510 > TMPL_ARGS_DEPTH (args))
8513 location_t saved_input_location;
8514 parms = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_tmpl),
8515 args, tf_warning_or_error);
8517 saved_input_location = input_location;
8518 input_location = DECL_SOURCE_LOCATION (friend_tmpl);
8519 redeclare_class_template (TREE_TYPE (tmpl), parms);
8520 input_location = saved_input_location;
8524 friend_type = TREE_TYPE (tmpl);
8528 /* The friend template has not already been declared. In this
8529 case, the instantiation of the template class will cause the
8530 injection of this template into the global scope. */
8531 tmpl = tsubst (friend_tmpl, args, tf_warning_or_error, NULL_TREE);
8532 if (tmpl == error_mark_node)
8533 return error_mark_node;
8535 /* The new TMPL is not an instantiation of anything, so we
8536 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
8537 the new type because that is supposed to be the corresponding
8538 template decl, i.e., TMPL. */
8539 DECL_USE_TEMPLATE (tmpl) = 0;
8540 DECL_TEMPLATE_INFO (tmpl) = NULL_TREE;
8541 CLASSTYPE_USE_TEMPLATE (TREE_TYPE (tmpl)) = 0;
8542 CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl))
8543 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl)));
8545 /* Inject this template into the global scope. */
8546 friend_type = TREE_TYPE (pushdecl_top_level_maybe_friend (tmpl, true));
8549 if (context != global_namespace)
8551 if (TREE_CODE (context) == NAMESPACE_DECL)
8552 pop_nested_namespace (context);
8554 pop_nested_class ();
8560 /* Returns zero if TYPE cannot be completed later due to circularity.
8561 Otherwise returns one. */
8564 can_complete_type_without_circularity (tree type)
8566 if (type == NULL_TREE || type == error_mark_node)
8568 else if (COMPLETE_TYPE_P (type))
8570 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
8571 return can_complete_type_without_circularity (TREE_TYPE (type));
8572 else if (CLASS_TYPE_P (type)
8573 && TYPE_BEING_DEFINED (TYPE_MAIN_VARIANT (type)))
8579 /* Apply any attributes which had to be deferred until instantiation
8580 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
8581 ARGS, COMPLAIN, IN_DECL are as tsubst. */
8584 apply_late_template_attributes (tree *decl_p, tree attributes, int attr_flags,
8585 tree args, tsubst_flags_t complain, tree in_decl)
8587 tree last_dep = NULL_TREE;
8591 for (t = attributes; t; t = TREE_CHAIN (t))
8592 if (ATTR_IS_DEPENDENT (t))
8595 attributes = copy_list (attributes);
8599 if (DECL_P (*decl_p))
8601 if (TREE_TYPE (*decl_p) == error_mark_node)
8603 p = &DECL_ATTRIBUTES (*decl_p);
8606 p = &TYPE_ATTRIBUTES (*decl_p);
8610 tree late_attrs = NULL_TREE;
8611 tree *q = &late_attrs;
8613 for (*p = attributes; *p; )
8616 if (ATTR_IS_DEPENDENT (t))
8618 *p = TREE_CHAIN (t);
8619 TREE_CHAIN (t) = NULL_TREE;
8620 /* If the first attribute argument is an identifier, don't
8621 pass it through tsubst. Attributes like mode, format,
8622 cleanup and several target specific attributes expect it
8625 && TREE_CODE (TREE_VALUE (t)) == TREE_LIST
8626 && TREE_VALUE (TREE_VALUE (t))
8627 && (TREE_CODE (TREE_VALUE (TREE_VALUE (t)))
8628 == IDENTIFIER_NODE))
8631 = tsubst_expr (TREE_CHAIN (TREE_VALUE (t)), args, complain,
8633 /*integral_constant_expression_p=*/false);
8634 if (chain != TREE_CHAIN (TREE_VALUE (t)))
8636 = tree_cons (NULL_TREE, TREE_VALUE (TREE_VALUE (t)),
8641 = tsubst_expr (TREE_VALUE (t), args, complain, in_decl,
8642 /*integral_constant_expression_p=*/false);
8644 q = &TREE_CHAIN (t);
8647 p = &TREE_CHAIN (t);
8650 cplus_decl_attributes (decl_p, late_attrs, attr_flags);
8654 /* Perform (or defer) access check for typedefs that were referenced
8655 from within the template TMPL code.
8656 This is a subroutine of instantiate_template and instantiate_class_template.
8657 TMPL is the template to consider and TARGS is the list of arguments of
8661 perform_typedefs_access_check (tree tmpl, tree targs)
8663 location_t saved_location;
8665 qualified_typedef_usage_t *iter;
8668 || (!CLASS_TYPE_P (tmpl)
8669 && TREE_CODE (tmpl) != FUNCTION_DECL))
8672 saved_location = input_location;
8673 FOR_EACH_VEC_ELT (qualified_typedef_usage_t,
8674 get_types_needing_access_check (tmpl),
8677 tree type_decl = iter->typedef_decl;
8678 tree type_scope = iter->context;
8680 if (!type_decl || !type_scope || !CLASS_TYPE_P (type_scope))
8683 if (uses_template_parms (type_decl))
8684 type_decl = tsubst (type_decl, targs, tf_error, NULL_TREE);
8685 if (uses_template_parms (type_scope))
8686 type_scope = tsubst (type_scope, targs, tf_error, NULL_TREE);
8688 /* Make access check error messages point to the location
8689 of the use of the typedef. */
8690 input_location = iter->locus;
8691 perform_or_defer_access_check (TYPE_BINFO (type_scope),
8692 type_decl, type_decl);
8694 input_location = saved_location;
8698 instantiate_class_template_1 (tree type)
8700 tree templ, args, pattern, t, member;
8704 unsigned int saved_maximum_field_alignment;
8706 if (type == error_mark_node)
8707 return error_mark_node;
8709 if (COMPLETE_OR_OPEN_TYPE_P (type)
8710 || uses_template_parms (type))
8713 /* Figure out which template is being instantiated. */
8714 templ = most_general_template (CLASSTYPE_TI_TEMPLATE (type));
8715 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
8717 /* Determine what specialization of the original template to
8719 t = most_specialized_class (type, templ, tf_warning_or_error);
8720 if (t == error_mark_node)
8722 TYPE_BEING_DEFINED (type) = 1;
8723 return error_mark_node;
8727 /* This TYPE is actually an instantiation of a partial
8728 specialization. We replace the innermost set of ARGS with
8729 the arguments appropriate for substitution. For example,
8732 template <class T> struct S {};
8733 template <class T> struct S<T*> {};
8735 and supposing that we are instantiating S<int*>, ARGS will
8736 presently be {int*} -- but we need {int}. */
8737 pattern = TREE_TYPE (t);
8738 args = TREE_PURPOSE (t);
8742 pattern = TREE_TYPE (templ);
8743 args = CLASSTYPE_TI_ARGS (type);
8746 /* If the template we're instantiating is incomplete, then clearly
8747 there's nothing we can do. */
8748 if (!COMPLETE_TYPE_P (pattern))
8751 /* If we've recursively instantiated too many templates, stop. */
8752 if (! push_tinst_level (type))
8755 /* Now we're really doing the instantiation. Mark the type as in
8756 the process of being defined. */
8757 TYPE_BEING_DEFINED (type) = 1;
8759 /* We may be in the middle of deferred access check. Disable
8761 push_deferring_access_checks (dk_no_deferred);
8763 push_to_top_level ();
8764 /* Use #pragma pack from the template context. */
8765 saved_maximum_field_alignment = maximum_field_alignment;
8766 maximum_field_alignment = TYPE_PRECISION (pattern);
8768 SET_CLASSTYPE_INTERFACE_UNKNOWN (type);
8770 /* Set the input location to the most specialized template definition.
8771 This is needed if tsubsting causes an error. */
8772 typedecl = TYPE_MAIN_DECL (pattern);
8773 input_location = DECL_SOURCE_LOCATION (TYPE_NAME (type)) =
8774 DECL_SOURCE_LOCATION (typedecl);
8776 TYPE_PACKED (type) = TYPE_PACKED (pattern);
8777 TYPE_ALIGN (type) = TYPE_ALIGN (pattern);
8778 TYPE_USER_ALIGN (type) = TYPE_USER_ALIGN (pattern);
8779 TYPE_FOR_JAVA (type) = TYPE_FOR_JAVA (pattern); /* For libjava's JArray<T> */
8780 if (ANON_AGGR_TYPE_P (pattern))
8781 SET_ANON_AGGR_TYPE_P (type);
8782 if (CLASSTYPE_VISIBILITY_SPECIFIED (pattern))
8784 CLASSTYPE_VISIBILITY_SPECIFIED (type) = 1;
8785 CLASSTYPE_VISIBILITY (type) = CLASSTYPE_VISIBILITY (pattern);
8786 /* Adjust visibility for template arguments. */
8787 determine_visibility (TYPE_MAIN_DECL (type));
8789 CLASSTYPE_FINAL (type) = CLASSTYPE_FINAL (pattern);
8791 pbinfo = TYPE_BINFO (pattern);
8793 /* We should never instantiate a nested class before its enclosing
8794 class; we need to look up the nested class by name before we can
8795 instantiate it, and that lookup should instantiate the enclosing
8797 gcc_assert (!DECL_CLASS_SCOPE_P (TYPE_MAIN_DECL (pattern))
8798 || COMPLETE_OR_OPEN_TYPE_P (TYPE_CONTEXT (type)));
8800 base_list = NULL_TREE;
8801 if (BINFO_N_BASE_BINFOS (pbinfo))
8807 /* We must enter the scope containing the type, as that is where
8808 the accessibility of types named in dependent bases are
8810 pushed_scope = push_scope (CP_TYPE_CONTEXT (type));
8812 /* Substitute into each of the bases to determine the actual
8814 for (i = 0; BINFO_BASE_ITERATE (pbinfo, i, pbase_binfo); i++)
8817 tree access = BINFO_BASE_ACCESS (pbinfo, i);
8818 tree expanded_bases = NULL_TREE;
8821 if (PACK_EXPANSION_P (BINFO_TYPE (pbase_binfo)))
8824 tsubst_pack_expansion (BINFO_TYPE (pbase_binfo),
8825 args, tf_error, NULL_TREE);
8826 if (expanded_bases == error_mark_node)
8829 len = TREE_VEC_LENGTH (expanded_bases);
8832 for (idx = 0; idx < len; idx++)
8835 /* Extract the already-expanded base class. */
8836 base = TREE_VEC_ELT (expanded_bases, idx);
8838 /* Substitute to figure out the base class. */
8839 base = tsubst (BINFO_TYPE (pbase_binfo), args, tf_error,
8842 if (base == error_mark_node)
8845 base_list = tree_cons (access, base, base_list);
8846 if (BINFO_VIRTUAL_P (pbase_binfo))
8847 TREE_TYPE (base_list) = integer_type_node;
8851 /* The list is now in reverse order; correct that. */
8852 base_list = nreverse (base_list);
8855 pop_scope (pushed_scope);
8857 /* Now call xref_basetypes to set up all the base-class
8859 xref_basetypes (type, base_list);
8861 apply_late_template_attributes (&type, TYPE_ATTRIBUTES (pattern),
8862 (int) ATTR_FLAG_TYPE_IN_PLACE,
8863 args, tf_error, NULL_TREE);
8864 fixup_attribute_variants (type);
8866 /* Now that our base classes are set up, enter the scope of the
8867 class, so that name lookups into base classes, etc. will work
8868 correctly. This is precisely analogous to what we do in
8869 begin_class_definition when defining an ordinary non-template
8870 class, except we also need to push the enclosing classes. */
8871 push_nested_class (type);
8873 /* Now members are processed in the order of declaration. */
8874 for (member = CLASSTYPE_DECL_LIST (pattern);
8875 member; member = TREE_CHAIN (member))
8877 tree t = TREE_VALUE (member);
8879 if (TREE_PURPOSE (member))
8883 /* Build new CLASSTYPE_NESTED_UTDS. */
8886 bool class_template_p;
8888 class_template_p = (TREE_CODE (t) != ENUMERAL_TYPE
8889 && TYPE_LANG_SPECIFIC (t)
8890 && CLASSTYPE_IS_TEMPLATE (t));
8891 /* If the member is a class template, then -- even after
8892 substitution -- there may be dependent types in the
8893 template argument list for the class. We increment
8894 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
8895 that function will assume that no types are dependent
8896 when outside of a template. */
8897 if (class_template_p)
8898 ++processing_template_decl;
8899 newtag = tsubst (t, args, tf_error, NULL_TREE);
8900 if (class_template_p)
8901 --processing_template_decl;
8902 if (newtag == error_mark_node)
8905 if (TREE_CODE (newtag) != ENUMERAL_TYPE)
8907 tree name = TYPE_IDENTIFIER (t);
8909 if (class_template_p)
8910 /* Unfortunately, lookup_template_class sets
8911 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
8912 instantiation (i.e., for the type of a member
8913 template class nested within a template class.)
8914 This behavior is required for
8915 maybe_process_partial_specialization to work
8916 correctly, but is not accurate in this case;
8917 the TAG is not an instantiation of anything.
8918 (The corresponding TEMPLATE_DECL is an
8919 instantiation, but the TYPE is not.) */
8920 CLASSTYPE_USE_TEMPLATE (newtag) = 0;
8922 /* Now, we call pushtag to put this NEWTAG into the scope of
8923 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
8924 pushtag calling push_template_decl. We don't have to do
8925 this for enums because it will already have been done in
8928 SET_IDENTIFIER_TYPE_VALUE (name, newtag);
8929 pushtag (name, newtag, /*tag_scope=*/ts_current);
8932 else if (TREE_CODE (t) == FUNCTION_DECL
8933 || DECL_FUNCTION_TEMPLATE_P (t))
8935 /* Build new TYPE_METHODS. */
8938 if (TREE_CODE (t) == TEMPLATE_DECL)
8939 ++processing_template_decl;
8940 r = tsubst (t, args, tf_error, NULL_TREE);
8941 if (TREE_CODE (t) == TEMPLATE_DECL)
8942 --processing_template_decl;
8943 set_current_access_from_decl (r);
8944 finish_member_declaration (r);
8945 /* Instantiate members marked with attribute used. */
8946 if (r != error_mark_node && DECL_PRESERVE_P (r))
8951 /* Build new TYPE_FIELDS. */
8952 if (TREE_CODE (t) == STATIC_ASSERT)
8955 tsubst_expr (STATIC_ASSERT_CONDITION (t), args,
8956 tf_warning_or_error, NULL_TREE,
8957 /*integral_constant_expression_p=*/true);
8958 finish_static_assert (condition,
8959 STATIC_ASSERT_MESSAGE (t),
8960 STATIC_ASSERT_SOURCE_LOCATION (t),
8963 else if (TREE_CODE (t) != CONST_DECL)
8967 /* The file and line for this declaration, to
8968 assist in error message reporting. Since we
8969 called push_tinst_level above, we don't need to
8971 input_location = DECL_SOURCE_LOCATION (t);
8973 if (TREE_CODE (t) == TEMPLATE_DECL)
8974 ++processing_template_decl;
8975 r = tsubst (t, args, tf_warning_or_error, NULL_TREE);
8976 if (TREE_CODE (t) == TEMPLATE_DECL)
8977 --processing_template_decl;
8978 if (TREE_CODE (r) == VAR_DECL)
8982 [t]he initialization (and any associated
8983 side-effects) of a static data member does
8984 not occur unless the static data member is
8985 itself used in a way that requires the
8986 definition of the static data member to
8989 Therefore, we do not substitute into the
8990 initialized for the static data member here. */
8991 finish_static_data_member_decl
8994 /*init_const_expr_p=*/false,
8995 /*asmspec_tree=*/NULL_TREE,
8997 /* Instantiate members marked with attribute used. */
8998 if (r != error_mark_node && DECL_PRESERVE_P (r))
9001 else if (TREE_CODE (r) == FIELD_DECL)
9003 /* Determine whether R has a valid type and can be
9004 completed later. If R is invalid, then it is
9005 replaced by error_mark_node so that it will not be
9006 added to TYPE_FIELDS. */
9007 tree rtype = TREE_TYPE (r);
9008 if (can_complete_type_without_circularity (rtype))
9009 complete_type (rtype);
9011 if (!COMPLETE_TYPE_P (rtype))
9013 cxx_incomplete_type_error (r, rtype);
9014 r = error_mark_node;
9018 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
9019 such a thing will already have been added to the field
9020 list by tsubst_enum in finish_member_declaration in the
9021 CLASSTYPE_NESTED_UTDS case above. */
9022 if (!(TREE_CODE (r) == TYPE_DECL
9023 && TREE_CODE (TREE_TYPE (r)) == ENUMERAL_TYPE
9024 && DECL_ARTIFICIAL (r)))
9026 set_current_access_from_decl (r);
9027 finish_member_declaration (r);
9034 if (TYPE_P (t) || DECL_CLASS_TEMPLATE_P (t))
9036 /* Build new CLASSTYPE_FRIEND_CLASSES. */
9038 tree friend_type = t;
9039 bool adjust_processing_template_decl = false;
9041 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
9043 /* template <class T> friend class C; */
9044 friend_type = tsubst_friend_class (friend_type, args);
9045 adjust_processing_template_decl = true;
9047 else if (TREE_CODE (friend_type) == UNBOUND_CLASS_TEMPLATE)
9049 /* template <class T> friend class C::D; */
9050 friend_type = tsubst (friend_type, args,
9051 tf_warning_or_error, NULL_TREE);
9052 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
9053 friend_type = TREE_TYPE (friend_type);
9054 adjust_processing_template_decl = true;
9056 else if (TREE_CODE (friend_type) == TYPENAME_TYPE
9057 || TREE_CODE (friend_type) == TEMPLATE_TYPE_PARM)
9059 /* This could be either
9063 when dependent_type_p is false or
9065 template <class U> friend class T::C;
9068 friend_type = tsubst (friend_type, args,
9069 tf_warning_or_error, NULL_TREE);
9070 /* Bump processing_template_decl for correct
9071 dependent_type_p calculation. */
9072 ++processing_template_decl;
9073 if (dependent_type_p (friend_type))
9074 adjust_processing_template_decl = true;
9075 --processing_template_decl;
9077 else if (!CLASSTYPE_USE_TEMPLATE (friend_type)
9078 && hidden_name_p (TYPE_NAME (friend_type)))
9082 where C hasn't been declared yet. Let's lookup name
9083 from namespace scope directly, bypassing any name that
9084 come from dependent base class. */
9085 tree ns = decl_namespace_context (TYPE_MAIN_DECL (friend_type));
9087 /* The call to xref_tag_from_type does injection for friend
9089 push_nested_namespace (ns);
9091 xref_tag_from_type (friend_type, NULL_TREE,
9092 /*tag_scope=*/ts_current);
9093 pop_nested_namespace (ns);
9095 else if (uses_template_parms (friend_type))
9096 /* friend class C<T>; */
9097 friend_type = tsubst (friend_type, args,
9098 tf_warning_or_error, NULL_TREE);
9103 where C is already declared or
9105 friend class C<int>;
9107 We don't have to do anything in these cases. */
9109 if (adjust_processing_template_decl)
9110 /* Trick make_friend_class into realizing that the friend
9111 we're adding is a template, not an ordinary class. It's
9112 important that we use make_friend_class since it will
9113 perform some error-checking and output cross-reference
9115 ++processing_template_decl;
9117 if (friend_type != error_mark_node)
9118 make_friend_class (type, friend_type, /*complain=*/false);
9120 if (adjust_processing_template_decl)
9121 --processing_template_decl;
9125 /* Build new DECL_FRIENDLIST. */
9128 /* The file and line for this declaration, to
9129 assist in error message reporting. Since we
9130 called push_tinst_level above, we don't need to
9132 input_location = DECL_SOURCE_LOCATION (t);
9134 if (TREE_CODE (t) == TEMPLATE_DECL)
9136 ++processing_template_decl;
9137 push_deferring_access_checks (dk_no_check);
9140 r = tsubst_friend_function (t, args);
9141 add_friend (type, r, /*complain=*/false);
9142 if (TREE_CODE (t) == TEMPLATE_DECL)
9144 pop_deferring_access_checks ();
9145 --processing_template_decl;
9151 if (CLASSTYPE_LAMBDA_EXPR (type))
9153 tree decl = lambda_function (type);
9156 tree lambda = CLASSTYPE_LAMBDA_EXPR (type);
9157 if (LAMBDA_EXPR_DEDUCE_RETURN_TYPE_P (lambda))
9159 apply_lambda_return_type (lambda, void_type_node);
9160 LAMBDA_EXPR_RETURN_TYPE (lambda) = NULL_TREE;
9162 instantiate_decl (decl, false, false);
9163 maybe_add_lambda_conv_op (type);
9166 gcc_assert (errorcount);
9169 /* Set the file and line number information to whatever is given for
9170 the class itself. This puts error messages involving generated
9171 implicit functions at a predictable point, and the same point
9172 that would be used for non-template classes. */
9173 input_location = DECL_SOURCE_LOCATION (typedecl);
9175 unreverse_member_declarations (type);
9176 finish_struct_1 (type);
9177 TYPE_BEING_DEFINED (type) = 0;
9179 /* We don't instantiate default arguments for member functions. 14.7.1:
9181 The implicit instantiation of a class template specialization causes
9182 the implicit instantiation of the declarations, but not of the
9183 definitions or default arguments, of the class member functions,
9184 member classes, static data members and member templates.... */
9186 /* Some typedefs referenced from within the template code need to be access
9187 checked at template instantiation time, i.e now. These types were
9188 added to the template at parsing time. Let's get those and perform
9189 the access checks then. */
9190 perform_typedefs_access_check (pattern, args);
9191 perform_deferred_access_checks ();
9192 pop_nested_class ();
9193 maximum_field_alignment = saved_maximum_field_alignment;
9194 pop_from_top_level ();
9195 pop_deferring_access_checks ();
9198 /* The vtable for a template class can be emitted in any translation
9199 unit in which the class is instantiated. When there is no key
9200 method, however, finish_struct_1 will already have added TYPE to
9201 the keyed_classes list. */
9202 if (TYPE_CONTAINS_VPTR_P (type) && CLASSTYPE_KEY_METHOD (type))
9203 keyed_classes = tree_cons (NULL_TREE, type, keyed_classes);
9208 /* Wrapper for instantiate_class_template_1. */
9211 instantiate_class_template (tree type)
9214 timevar_push (TV_TEMPLATE_INST);
9215 ret = instantiate_class_template_1 (type);
9216 timevar_pop (TV_TEMPLATE_INST);
9221 tsubst_template_arg (tree t, tree args, tsubst_flags_t complain, tree in_decl)
9227 else if (TYPE_P (t))
9228 r = tsubst (t, args, complain, in_decl);
9231 if (!(complain & tf_warning))
9232 ++c_inhibit_evaluation_warnings;
9233 r = tsubst_expr (t, args, complain, in_decl,
9234 /*integral_constant_expression_p=*/true);
9235 if (!(complain & tf_warning))
9236 --c_inhibit_evaluation_warnings;
9237 /* Preserve the raw-reference nature of T. */
9238 if (TREE_TYPE (t) && TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE
9239 && REFERENCE_REF_P (r))
9240 r = TREE_OPERAND (r, 0);
9245 /* Given a function parameter pack TMPL_PARM and some function parameters
9246 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
9247 and set *SPEC_P to point at the next point in the list. */
9250 extract_fnparm_pack (tree tmpl_parm, tree *spec_p)
9252 /* Collect all of the extra "packed" parameters into an
9256 tree argpack = make_node (NONTYPE_ARGUMENT_PACK);
9257 tree argtypepack = cxx_make_type (TYPE_ARGUMENT_PACK);
9258 tree spec_parm = *spec_p;
9261 for (len = 0; spec_parm; ++len, spec_parm = TREE_CHAIN (spec_parm))
9263 && !function_parameter_expanded_from_pack_p (spec_parm, tmpl_parm))
9266 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
9267 parmvec = make_tree_vec (len);
9268 parmtypevec = make_tree_vec (len);
9269 spec_parm = *spec_p;
9270 for (i = 0; i < len; i++, spec_parm = DECL_CHAIN (spec_parm))
9272 TREE_VEC_ELT (parmvec, i) = spec_parm;
9273 TREE_VEC_ELT (parmtypevec, i) = TREE_TYPE (spec_parm);
9276 /* Build the argument packs. */
9277 SET_ARGUMENT_PACK_ARGS (argpack, parmvec);
9278 SET_ARGUMENT_PACK_ARGS (argtypepack, parmtypevec);
9279 TREE_TYPE (argpack) = argtypepack;
9280 *spec_p = spec_parm;
9285 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
9286 NONTYPE_ARGUMENT_PACK. */
9289 make_fnparm_pack (tree spec_parm)
9291 return extract_fnparm_pack (NULL_TREE, &spec_parm);
9294 /* Substitute ARGS into T, which is an pack expansion
9295 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
9296 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
9297 (if only a partial substitution could be performed) or
9298 ERROR_MARK_NODE if there was an error. */
9300 tsubst_pack_expansion (tree t, tree args, tsubst_flags_t complain,
9304 tree pack, packs = NULL_TREE;
9305 bool unsubstituted_packs = false;
9306 bool real_packs = false;
9307 int missing_level = 0;
9310 htab_t saved_local_specializations = NULL;
9311 bool need_local_specializations = false;
9314 gcc_assert (PACK_EXPANSION_P (t));
9315 pattern = PACK_EXPANSION_PATTERN (t);
9317 /* Add in any args remembered from an earlier partial instantiation. */
9318 args = add_to_template_args (PACK_EXPANSION_EXTRA_ARGS (t), args);
9320 levels = TMPL_ARGS_DEPTH (args);
9322 /* Determine the argument packs that will instantiate the parameter
9323 packs used in the expansion expression. While we're at it,
9324 compute the number of arguments to be expanded and make sure it
9326 for (pack = PACK_EXPANSION_PARAMETER_PACKS (t); pack;
9327 pack = TREE_CHAIN (pack))
9329 tree parm_pack = TREE_VALUE (pack);
9330 tree arg_pack = NULL_TREE;
9331 tree orig_arg = NULL_TREE;
9334 if (TREE_CODE (parm_pack) == BASES)
9336 if (BASES_DIRECT (parm_pack))
9337 return calculate_direct_bases (tsubst_expr (BASES_TYPE (parm_pack),
9338 args, complain, in_decl, false));
9340 return calculate_bases (tsubst_expr (BASES_TYPE (parm_pack),
9341 args, complain, in_decl, false));
9343 if (TREE_CODE (parm_pack) == PARM_DECL)
9345 if (PACK_EXPANSION_LOCAL_P (t))
9346 arg_pack = retrieve_local_specialization (parm_pack);
9349 /* We can't rely on local_specializations for a parameter
9350 name used later in a function declaration (such as in a
9351 late-specified return type). Even if it exists, it might
9352 have the wrong value for a recursive call. Just make a
9353 dummy decl, since it's only used for its type. */
9354 arg_pack = tsubst_decl (parm_pack, args, complain);
9355 if (arg_pack && FUNCTION_PARAMETER_PACK_P (arg_pack))
9356 /* Partial instantiation of the parm_pack, we can't build
9357 up an argument pack yet. */
9358 arg_pack = NULL_TREE;
9360 arg_pack = make_fnparm_pack (arg_pack);
9361 need_local_specializations = true;
9367 template_parm_level_and_index (parm_pack, &level, &idx);
9369 if (level <= levels)
9370 arg_pack = TMPL_ARG (args, level, idx);
9373 orig_arg = arg_pack;
9374 if (arg_pack && TREE_CODE (arg_pack) == ARGUMENT_PACK_SELECT)
9375 arg_pack = ARGUMENT_PACK_SELECT_FROM_PACK (arg_pack);
9377 if (arg_pack && !ARGUMENT_PACK_P (arg_pack))
9378 /* This can only happen if we forget to expand an argument
9379 pack somewhere else. Just return an error, silently. */
9381 result = make_tree_vec (1);
9382 TREE_VEC_ELT (result, 0) = error_mark_node;
9386 if (arg_from_parm_pack_p (arg_pack, parm_pack))
9387 /* The argument pack that the parameter maps to is just an
9388 expansion of the parameter itself, such as one would find
9389 in the implicit typedef of a class inside the class itself.
9390 Consider this parameter "unsubstituted", so that we will
9391 maintain the outer pack expansion. */
9392 arg_pack = NULL_TREE;
9397 TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack));
9399 /* Don't bother trying to do a partial substitution with
9400 incomplete packs; we'll try again after deduction. */
9401 if (ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
9406 else if (len != my_len)
9408 if (!(complain & tf_error))
9409 /* Fail quietly. */;
9410 else if (TREE_CODE (t) == TYPE_PACK_EXPANSION)
9411 error ("mismatched argument pack lengths while expanding "
9415 error ("mismatched argument pack lengths while expanding "
9418 return error_mark_node;
9421 if (TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack)) == 1
9422 && PACK_EXPANSION_P (TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack),
9424 /* This isn't a real argument pack yet. */;
9428 /* Keep track of the parameter packs and their corresponding
9430 packs = tree_cons (parm_pack, arg_pack, packs);
9431 TREE_TYPE (packs) = orig_arg;
9435 /* We can't substitute for this parameter pack. We use a flag as
9436 well as the missing_level counter because function parameter
9437 packs don't have a level. */
9438 unsubstituted_packs = true;
9439 if (!missing_level || missing_level > level)
9440 missing_level = level;
9444 /* We cannot expand this expansion expression, because we don't have
9445 all of the argument packs we need. */
9446 if (unsubstituted_packs)
9450 /* We got some full packs, but we can't substitute them in until we
9451 have values for all the packs. So remember these until then. */
9454 t = make_pack_expansion (pattern);
9456 /* The call to add_to_template_args above assumes no overlap
9457 between saved args and new args, so prune away any fake
9458 args, i.e. those that satisfied arg_from_parm_pack_p above. */
9459 if (missing_level && levels >= missing_level)
9461 gcc_assert (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args)
9462 && missing_level > 1);
9463 TREE_VEC_LENGTH (args) = missing_level - 1;
9464 save_args = copy_node (args);
9465 TREE_VEC_LENGTH (args) = levels;
9470 PACK_EXPANSION_EXTRA_ARGS (t) = save_args;
9474 /* There were no real arguments, we're just replacing a parameter
9475 pack with another version of itself. Substitute into the
9476 pattern and return a PACK_EXPANSION_*. The caller will need to
9478 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
9479 t = tsubst_expr (pattern, args, complain, in_decl,
9480 /*integral_constant_expression_p=*/false);
9482 t = tsubst (pattern, args, complain, in_decl);
9483 t = make_pack_expansion (t);
9488 /* We could not find any argument packs that work. */
9490 return error_mark_node;
9492 if (need_local_specializations)
9494 /* We're in a late-specified return type, so create our own local
9495 specializations table; the current table is either NULL or (in the
9496 case of recursive unification) might have bindings that we don't
9497 want to use or alter. */
9498 saved_local_specializations = local_specializations;
9499 local_specializations = htab_create (37,
9500 hash_local_specialization,
9501 eq_local_specializations,
9505 /* For each argument in each argument pack, substitute into the
9507 result = make_tree_vec (len);
9508 for (i = 0; i < len; ++i)
9510 /* For parameter pack, change the substitution of the parameter
9511 pack to the ith argument in its argument pack, then expand
9513 for (pack = packs; pack; pack = TREE_CHAIN (pack))
9515 tree parm = TREE_PURPOSE (pack);
9518 /* Select the Ith argument from the pack. */
9519 if (TREE_CODE (parm) == PARM_DECL)
9523 arg = make_node (ARGUMENT_PACK_SELECT);
9524 ARGUMENT_PACK_SELECT_FROM_PACK (arg) = TREE_VALUE (pack);
9526 register_local_specialization (arg, parm);
9529 arg = retrieve_local_specialization (parm);
9534 template_parm_level_and_index (parm, &level, &idx);
9538 arg = make_node (ARGUMENT_PACK_SELECT);
9539 ARGUMENT_PACK_SELECT_FROM_PACK (arg) = TREE_VALUE (pack);
9540 /* Update the corresponding argument. */
9541 TMPL_ARG (args, level, idx) = arg;
9544 /* Re-use the ARGUMENT_PACK_SELECT. */
9545 arg = TMPL_ARG (args, level, idx);
9547 ARGUMENT_PACK_SELECT_INDEX (arg) = i;
9550 /* Substitute into the PATTERN with the altered arguments. */
9551 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
9552 TREE_VEC_ELT (result, i) =
9553 tsubst_expr (pattern, args, complain, in_decl,
9554 /*integral_constant_expression_p=*/false);
9556 TREE_VEC_ELT (result, i) = tsubst (pattern, args, complain, in_decl);
9558 if (TREE_VEC_ELT (result, i) == error_mark_node)
9560 result = error_mark_node;
9565 /* Update ARGS to restore the substitution from parameter packs to
9566 their argument packs. */
9567 for (pack = packs; pack; pack = TREE_CHAIN (pack))
9569 tree parm = TREE_PURPOSE (pack);
9571 if (TREE_CODE (parm) == PARM_DECL)
9572 register_local_specialization (TREE_TYPE (pack), parm);
9576 template_parm_level_and_index (parm, &level, &idx);
9578 /* Update the corresponding argument. */
9579 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
9580 TREE_VEC_ELT (TREE_VEC_ELT (args, level -1 ), idx) =
9583 TREE_VEC_ELT (args, idx) = TREE_TYPE (pack);
9587 if (need_local_specializations)
9589 htab_delete (local_specializations);
9590 local_specializations = saved_local_specializations;
9596 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
9597 TMPL. We do this using DECL_PARM_INDEX, which should work even with
9598 parameter packs; all parms generated from a function parameter pack will
9599 have the same DECL_PARM_INDEX. */
9602 get_pattern_parm (tree parm, tree tmpl)
9604 tree pattern = DECL_TEMPLATE_RESULT (tmpl);
9607 if (DECL_ARTIFICIAL (parm))
9609 for (patparm = DECL_ARGUMENTS (pattern);
9610 patparm; patparm = DECL_CHAIN (patparm))
9611 if (DECL_ARTIFICIAL (patparm)
9612 && DECL_NAME (parm) == DECL_NAME (patparm))
9617 patparm = FUNCTION_FIRST_USER_PARM (DECL_TEMPLATE_RESULT (tmpl));
9618 patparm = chain_index (DECL_PARM_INDEX (parm)-1, patparm);
9619 gcc_assert (DECL_PARM_INDEX (patparm)
9620 == DECL_PARM_INDEX (parm));
9626 /* Substitute ARGS into the vector or list of template arguments T. */
9629 tsubst_template_args (tree t, tree args, tsubst_flags_t complain, tree in_decl)
9632 int len, need_new = 0, i, expanded_len_adjust = 0, out;
9635 if (t == error_mark_node)
9636 return error_mark_node;
9638 len = TREE_VEC_LENGTH (t);
9639 elts = XALLOCAVEC (tree, len);
9641 for (i = 0; i < len; i++)
9643 tree orig_arg = TREE_VEC_ELT (t, i);
9646 if (TREE_CODE (orig_arg) == TREE_VEC)
9647 new_arg = tsubst_template_args (orig_arg, args, complain, in_decl);
9648 else if (PACK_EXPANSION_P (orig_arg))
9650 /* Substitute into an expansion expression. */
9651 new_arg = tsubst_pack_expansion (orig_arg, args, complain, in_decl);
9653 if (TREE_CODE (new_arg) == TREE_VEC)
9654 /* Add to the expanded length adjustment the number of
9655 expanded arguments. We subtract one from this
9656 measurement, because the argument pack expression
9657 itself is already counted as 1 in
9658 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
9659 the argument pack is empty. */
9660 expanded_len_adjust += TREE_VEC_LENGTH (new_arg) - 1;
9662 else if (ARGUMENT_PACK_P (orig_arg))
9664 /* Substitute into each of the arguments. */
9665 new_arg = TYPE_P (orig_arg)
9666 ? cxx_make_type (TREE_CODE (orig_arg))
9667 : make_node (TREE_CODE (orig_arg));
9669 SET_ARGUMENT_PACK_ARGS (
9671 tsubst_template_args (ARGUMENT_PACK_ARGS (orig_arg),
9672 args, complain, in_decl));
9674 if (ARGUMENT_PACK_ARGS (new_arg) == error_mark_node)
9675 new_arg = error_mark_node;
9677 if (TREE_CODE (new_arg) == NONTYPE_ARGUMENT_PACK) {
9678 TREE_TYPE (new_arg) = tsubst (TREE_TYPE (orig_arg), args,
9680 TREE_CONSTANT (new_arg) = TREE_CONSTANT (orig_arg);
9682 if (TREE_TYPE (new_arg) == error_mark_node)
9683 new_arg = error_mark_node;
9687 new_arg = tsubst_template_arg (orig_arg, args, complain, in_decl);
9689 if (new_arg == error_mark_node)
9690 return error_mark_node;
9693 if (new_arg != orig_arg)
9700 /* Make space for the expanded arguments coming from template
9702 t = make_tree_vec (len + expanded_len_adjust);
9703 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
9704 arguments for a member template.
9705 In that case each TREE_VEC in ORIG_T represents a level of template
9706 arguments, and ORIG_T won't carry any non defaulted argument count.
9707 It will rather be the nested TREE_VECs that will carry one.
9708 In other words, ORIG_T carries a non defaulted argument count only
9709 if it doesn't contain any nested TREE_VEC. */
9710 if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t))
9712 int count = GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t);
9713 count += expanded_len_adjust;
9714 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (t, count);
9716 for (i = 0, out = 0; i < len; i++)
9718 if ((PACK_EXPANSION_P (TREE_VEC_ELT (orig_t, i))
9719 || ARGUMENT_PACK_P (TREE_VEC_ELT (orig_t, i)))
9720 && TREE_CODE (elts[i]) == TREE_VEC)
9724 /* Now expand the template argument pack "in place". */
9725 for (idx = 0; idx < TREE_VEC_LENGTH (elts[i]); idx++, out++)
9726 TREE_VEC_ELT (t, out) = TREE_VEC_ELT (elts[i], idx);
9730 TREE_VEC_ELT (t, out) = elts[i];
9738 /* Return the result of substituting ARGS into the template parameters
9739 given by PARMS. If there are m levels of ARGS and m + n levels of
9740 PARMS, then the result will contain n levels of PARMS. For
9741 example, if PARMS is `template <class T> template <class U>
9742 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
9743 result will be `template <int*, double, class V>'. */
9746 tsubst_template_parms (tree parms, tree args, tsubst_flags_t complain)
9751 /* When substituting into a template, we must set
9752 PROCESSING_TEMPLATE_DECL as the template parameters may be
9753 dependent if they are based on one-another, and the dependency
9754 predicates are short-circuit outside of templates. */
9755 ++processing_template_decl;
9757 for (new_parms = &r;
9758 TMPL_PARMS_DEPTH (parms) > TMPL_ARGS_DEPTH (args);
9759 new_parms = &(TREE_CHAIN (*new_parms)),
9760 parms = TREE_CHAIN (parms))
9763 make_tree_vec (TREE_VEC_LENGTH (TREE_VALUE (parms)));
9766 for (i = 0; i < TREE_VEC_LENGTH (new_vec); ++i)
9770 if (parms == error_mark_node)
9773 tuple = TREE_VEC_ELT (TREE_VALUE (parms), i);
9775 if (tuple == error_mark_node)
9778 TREE_VEC_ELT (new_vec, i) =
9779 tsubst_template_parm (tuple, args, complain);
9783 tree_cons (size_int (TMPL_PARMS_DEPTH (parms)
9784 - TMPL_ARGS_DEPTH (args)),
9785 new_vec, NULL_TREE);
9788 --processing_template_decl;
9793 /* Return the result of substituting ARGS into one template parameter
9794 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
9795 parameter and which TREE_PURPOSE is the default argument of the
9796 template parameter. */
9799 tsubst_template_parm (tree t, tree args, tsubst_flags_t complain)
9801 tree default_value, parm_decl;
9803 if (args == NULL_TREE
9805 || t == error_mark_node)
9808 gcc_assert (TREE_CODE (t) == TREE_LIST);
9810 default_value = TREE_PURPOSE (t);
9811 parm_decl = TREE_VALUE (t);
9813 parm_decl = tsubst (parm_decl, args, complain, NULL_TREE);
9814 if (TREE_CODE (parm_decl) == PARM_DECL
9815 && invalid_nontype_parm_type_p (TREE_TYPE (parm_decl), complain))
9816 parm_decl = error_mark_node;
9817 default_value = tsubst_template_arg (default_value, args,
9818 complain, NULL_TREE);
9820 return build_tree_list (default_value, parm_decl);
9823 /* Substitute the ARGS into the indicated aggregate (or enumeration)
9824 type T. If T is not an aggregate or enumeration type, it is
9825 handled as if by tsubst. IN_DECL is as for tsubst. If
9826 ENTERING_SCOPE is nonzero, T is the context for a template which
9827 we are presently tsubst'ing. Return the substituted value. */
9830 tsubst_aggr_type (tree t,
9832 tsubst_flags_t complain,
9839 switch (TREE_CODE (t))
9842 if (TYPE_PTRMEMFUNC_P (t))
9843 return tsubst (TYPE_PTRMEMFUNC_FN_TYPE (t), args, complain, in_decl);
9845 /* Else fall through. */
9848 if (TYPE_TEMPLATE_INFO (t) && uses_template_parms (t))
9853 int saved_unevaluated_operand;
9854 int saved_inhibit_evaluation_warnings;
9856 /* In "sizeof(X<I>)" we need to evaluate "I". */
9857 saved_unevaluated_operand = cp_unevaluated_operand;
9858 cp_unevaluated_operand = 0;
9859 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
9860 c_inhibit_evaluation_warnings = 0;
9862 /* First, determine the context for the type we are looking
9864 context = TYPE_CONTEXT (t);
9865 if (context && TYPE_P (context))
9867 context = tsubst_aggr_type (context, args, complain,
9868 in_decl, /*entering_scope=*/1);
9869 /* If context is a nested class inside a class template,
9870 it may still need to be instantiated (c++/33959). */
9871 context = complete_type (context);
9874 /* Then, figure out what arguments are appropriate for the
9875 type we are trying to find. For example, given:
9877 template <class T> struct S;
9878 template <class T, class U> void f(T, U) { S<U> su; }
9880 and supposing that we are instantiating f<int, double>,
9881 then our ARGS will be {int, double}, but, when looking up
9882 S we only want {double}. */
9883 argvec = tsubst_template_args (TYPE_TI_ARGS (t), args,
9885 if (argvec == error_mark_node)
9886 r = error_mark_node;
9889 r = lookup_template_class (t, argvec, in_decl, context,
9890 entering_scope, complain);
9891 r = cp_build_qualified_type_real (r, cp_type_quals (t), complain);
9894 cp_unevaluated_operand = saved_unevaluated_operand;
9895 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
9900 /* This is not a template type, so there's nothing to do. */
9904 return tsubst (t, args, complain, in_decl);
9908 /* Substitute into the default argument ARG (a default argument for
9909 FN), which has the indicated TYPE. */
9912 tsubst_default_argument (tree fn, tree type, tree arg)
9914 tree saved_class_ptr = NULL_TREE;
9915 tree saved_class_ref = NULL_TREE;
9917 /* This can happen in invalid code. */
9918 if (TREE_CODE (arg) == DEFAULT_ARG)
9921 /* This default argument came from a template. Instantiate the
9922 default argument here, not in tsubst. In the case of
9931 we must be careful to do name lookup in the scope of S<T>,
9932 rather than in the current class. */
9933 push_access_scope (fn);
9934 /* The "this" pointer is not valid in a default argument. */
9937 saved_class_ptr = current_class_ptr;
9938 cp_function_chain->x_current_class_ptr = NULL_TREE;
9939 saved_class_ref = current_class_ref;
9940 cp_function_chain->x_current_class_ref = NULL_TREE;
9943 push_deferring_access_checks(dk_no_deferred);
9944 /* The default argument expression may cause implicitly defined
9945 member functions to be synthesized, which will result in garbage
9946 collection. We must treat this situation as if we were within
9947 the body of function so as to avoid collecting live data on the
9950 arg = tsubst_expr (arg, DECL_TI_ARGS (fn),
9951 tf_warning_or_error, NULL_TREE,
9952 /*integral_constant_expression_p=*/false);
9954 pop_deferring_access_checks();
9956 /* Restore the "this" pointer. */
9959 cp_function_chain->x_current_class_ptr = saved_class_ptr;
9960 cp_function_chain->x_current_class_ref = saved_class_ref;
9963 /* Make sure the default argument is reasonable. */
9964 arg = check_default_argument (type, arg);
9966 pop_access_scope (fn);
9971 /* Substitute into all the default arguments for FN. */
9974 tsubst_default_arguments (tree fn)
9979 tmpl_args = DECL_TI_ARGS (fn);
9981 /* If this function is not yet instantiated, we certainly don't need
9982 its default arguments. */
9983 if (uses_template_parms (tmpl_args))
9985 /* Don't do this again for clones. */
9986 if (DECL_CLONED_FUNCTION_P (fn))
9989 for (arg = TYPE_ARG_TYPES (TREE_TYPE (fn));
9991 arg = TREE_CHAIN (arg))
9992 if (TREE_PURPOSE (arg))
9993 TREE_PURPOSE (arg) = tsubst_default_argument (fn,
9995 TREE_PURPOSE (arg));
9998 /* Substitute the ARGS into the T, which is a _DECL. Return the
9999 result of the substitution. Issue error and warning messages under
10000 control of COMPLAIN. */
10003 tsubst_decl (tree t, tree args, tsubst_flags_t complain)
10005 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
10006 location_t saved_loc;
10007 tree r = NULL_TREE;
10009 hashval_t hash = 0;
10011 /* Set the filename and linenumber to improve error-reporting. */
10012 saved_loc = input_location;
10013 input_location = DECL_SOURCE_LOCATION (t);
10015 switch (TREE_CODE (t))
10017 case TEMPLATE_DECL:
10019 /* We can get here when processing a member function template,
10020 member class template, or template template parameter. */
10021 tree decl = DECL_TEMPLATE_RESULT (t);
10026 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
10028 /* Template template parameter is treated here. */
10029 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10030 if (new_type == error_mark_node)
10031 RETURN (error_mark_node);
10034 DECL_CHAIN (r) = NULL_TREE;
10035 TREE_TYPE (r) = new_type;
10036 DECL_TEMPLATE_RESULT (r)
10037 = build_decl (DECL_SOURCE_LOCATION (decl),
10038 TYPE_DECL, DECL_NAME (decl), new_type);
10039 DECL_TEMPLATE_PARMS (r)
10040 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
10042 TYPE_NAME (new_type) = r;
10046 /* We might already have an instance of this template.
10047 The ARGS are for the surrounding class type, so the
10048 full args contain the tsubst'd args for the context,
10049 plus the innermost args from the template decl. */
10050 tmpl_args = DECL_CLASS_TEMPLATE_P (t)
10051 ? CLASSTYPE_TI_ARGS (TREE_TYPE (t))
10052 : DECL_TI_ARGS (DECL_TEMPLATE_RESULT (t));
10053 /* Because this is a template, the arguments will still be
10054 dependent, even after substitution. If
10055 PROCESSING_TEMPLATE_DECL is not set, the dependency
10056 predicates will short-circuit. */
10057 ++processing_template_decl;
10058 full_args = tsubst_template_args (tmpl_args, args,
10059 complain, in_decl);
10060 --processing_template_decl;
10061 if (full_args == error_mark_node)
10062 RETURN (error_mark_node);
10064 /* If this is a default template template argument,
10065 tsubst might not have changed anything. */
10066 if (full_args == tmpl_args)
10069 hash = hash_tmpl_and_args (t, full_args);
10070 spec = retrieve_specialization (t, full_args, hash);
10071 if (spec != NULL_TREE)
10077 /* Make a new template decl. It will be similar to the
10078 original, but will record the current template arguments.
10079 We also create a new function declaration, which is just
10080 like the old one, but points to this new template, rather
10081 than the old one. */
10083 gcc_assert (DECL_LANG_SPECIFIC (r) != 0);
10084 DECL_CHAIN (r) = NULL_TREE;
10086 DECL_TEMPLATE_INFO (r) = build_template_info (t, args);
10088 if (TREE_CODE (decl) == TYPE_DECL
10089 && !TYPE_DECL_ALIAS_P (decl))
10092 ++processing_template_decl;
10093 new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10094 --processing_template_decl;
10095 if (new_type == error_mark_node)
10096 RETURN (error_mark_node);
10098 TREE_TYPE (r) = new_type;
10099 CLASSTYPE_TI_TEMPLATE (new_type) = r;
10100 DECL_TEMPLATE_RESULT (r) = TYPE_MAIN_DECL (new_type);
10101 DECL_TI_ARGS (r) = CLASSTYPE_TI_ARGS (new_type);
10102 DECL_CONTEXT (r) = TYPE_CONTEXT (new_type);
10107 ++processing_template_decl;
10108 new_decl = tsubst (decl, args, complain, in_decl);
10109 --processing_template_decl;
10110 if (new_decl == error_mark_node)
10111 RETURN (error_mark_node);
10113 DECL_TEMPLATE_RESULT (r) = new_decl;
10114 DECL_TI_TEMPLATE (new_decl) = r;
10115 TREE_TYPE (r) = TREE_TYPE (new_decl);
10116 DECL_TI_ARGS (r) = DECL_TI_ARGS (new_decl);
10117 DECL_CONTEXT (r) = DECL_CONTEXT (new_decl);
10120 SET_DECL_IMPLICIT_INSTANTIATION (r);
10121 DECL_TEMPLATE_INSTANTIATIONS (r) = NULL_TREE;
10122 DECL_TEMPLATE_SPECIALIZATIONS (r) = NULL_TREE;
10124 /* The template parameters for this new template are all the
10125 template parameters for the old template, except the
10126 outermost level of parameters. */
10127 DECL_TEMPLATE_PARMS (r)
10128 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
10131 if (PRIMARY_TEMPLATE_P (t))
10132 DECL_PRIMARY_TEMPLATE (r) = r;
10134 if (TREE_CODE (decl) != TYPE_DECL)
10135 /* Record this non-type partial instantiation. */
10136 register_specialization (r, t,
10137 DECL_TI_ARGS (DECL_TEMPLATE_RESULT (r)),
10142 case FUNCTION_DECL:
10145 tree argvec = NULL_TREE;
10153 /* Nobody should be tsubst'ing into non-template functions. */
10154 gcc_assert (DECL_TEMPLATE_INFO (t) != NULL_TREE);
10156 if (TREE_CODE (DECL_TI_TEMPLATE (t)) == TEMPLATE_DECL)
10161 /* If T is not dependent, just return it. We have to
10162 increment PROCESSING_TEMPLATE_DECL because
10163 value_dependent_expression_p assumes that nothing is
10164 dependent when PROCESSING_TEMPLATE_DECL is zero. */
10165 ++processing_template_decl;
10166 dependent_p = value_dependent_expression_p (t);
10167 --processing_template_decl;
10171 /* Calculate the most general template of which R is a
10172 specialization, and the complete set of arguments used to
10174 gen_tmpl = most_general_template (DECL_TI_TEMPLATE (t));
10175 argvec = tsubst_template_args (DECL_TI_ARGS
10176 (DECL_TEMPLATE_RESULT
10177 (DECL_TI_TEMPLATE (t))),
10178 args, complain, in_decl);
10179 if (argvec == error_mark_node)
10180 RETURN (error_mark_node);
10182 /* Check to see if we already have this specialization. */
10183 hash = hash_tmpl_and_args (gen_tmpl, argvec);
10184 spec = retrieve_specialization (gen_tmpl, argvec, hash);
10192 /* We can see more levels of arguments than parameters if
10193 there was a specialization of a member template, like
10196 template <class T> struct S { template <class U> void f(); }
10197 template <> template <class U> void S<int>::f(U);
10199 Here, we'll be substituting into the specialization,
10200 because that's where we can find the code we actually
10201 want to generate, but we'll have enough arguments for
10202 the most general template.
10204 We also deal with the peculiar case:
10206 template <class T> struct S {
10207 template <class U> friend void f();
10209 template <class U> void f() {}
10211 template void f<double>();
10213 Here, the ARGS for the instantiation of will be {int,
10214 double}. But, we only need as many ARGS as there are
10215 levels of template parameters in CODE_PATTERN. We are
10216 careful not to get fooled into reducing the ARGS in
10219 template <class T> struct S { template <class U> void f(U); }
10220 template <class T> template <> void S<T>::f(int) {}
10222 which we can spot because the pattern will be a
10223 specialization in this case. */
10224 args_depth = TMPL_ARGS_DEPTH (args);
10226 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (t)));
10227 if (args_depth > parms_depth
10228 && !DECL_TEMPLATE_SPECIALIZATION (t))
10229 args = get_innermost_template_args (args, parms_depth);
10233 /* This special case arises when we have something like this:
10235 template <class T> struct S {
10236 friend void f<int>(int, double);
10239 Here, the DECL_TI_TEMPLATE for the friend declaration
10240 will be an IDENTIFIER_NODE. We are being called from
10241 tsubst_friend_function, and we want only to create a
10242 new decl (R) with appropriate types so that we can call
10243 determine_specialization. */
10244 gen_tmpl = NULL_TREE;
10247 if (DECL_CLASS_SCOPE_P (t))
10249 if (DECL_NAME (t) == constructor_name (DECL_CONTEXT (t)))
10253 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args,
10254 complain, t, /*entering_scope=*/1);
10259 ctx = DECL_CONTEXT (t);
10261 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10262 if (type == error_mark_node)
10263 RETURN (error_mark_node);
10265 /* We do NOT check for matching decls pushed separately at this
10266 point, as they may not represent instantiations of this
10267 template, and in any case are considered separate under the
10270 DECL_USE_TEMPLATE (r) = 0;
10271 TREE_TYPE (r) = type;
10272 /* Clear out the mangled name and RTL for the instantiation. */
10273 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
10274 SET_DECL_RTL (r, NULL);
10275 /* Leave DECL_INITIAL set on deleted instantiations. */
10276 if (!DECL_DELETED_FN (r))
10277 DECL_INITIAL (r) = NULL_TREE;
10278 DECL_CONTEXT (r) = ctx;
10280 if (member && DECL_CONV_FN_P (r))
10281 /* Type-conversion operator. Reconstruct the name, in
10282 case it's the name of one of the template's parameters. */
10283 DECL_NAME (r) = mangle_conv_op_name_for_type (TREE_TYPE (type));
10285 DECL_ARGUMENTS (r) = tsubst (DECL_ARGUMENTS (t), args,
10287 DECL_RESULT (r) = NULL_TREE;
10289 TREE_STATIC (r) = 0;
10290 TREE_PUBLIC (r) = TREE_PUBLIC (t);
10291 DECL_EXTERNAL (r) = 1;
10292 /* If this is an instantiation of a function with internal
10293 linkage, we already know what object file linkage will be
10294 assigned to the instantiation. */
10295 DECL_INTERFACE_KNOWN (r) = !TREE_PUBLIC (r);
10296 DECL_DEFER_OUTPUT (r) = 0;
10297 DECL_CHAIN (r) = NULL_TREE;
10298 DECL_PENDING_INLINE_INFO (r) = 0;
10299 DECL_PENDING_INLINE_P (r) = 0;
10300 DECL_SAVED_TREE (r) = NULL_TREE;
10301 DECL_STRUCT_FUNCTION (r) = NULL;
10303 /* We'll re-clone as appropriate in instantiate_template. */
10304 DECL_CLONED_FUNCTION (r) = NULL_TREE;
10306 /* If we aren't complaining now, return on error before we register
10307 the specialization so that we'll complain eventually. */
10308 if ((complain & tf_error) == 0
10309 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
10310 && !grok_op_properties (r, /*complain=*/false))
10311 RETURN (error_mark_node);
10313 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
10314 this in the special friend case mentioned above where
10315 GEN_TMPL is NULL. */
10318 DECL_TEMPLATE_INFO (r)
10319 = build_template_info (gen_tmpl, argvec);
10320 SET_DECL_IMPLICIT_INSTANTIATION (r);
10321 register_specialization (r, gen_tmpl, argvec, false, hash);
10323 /* We're not supposed to instantiate default arguments
10324 until they are called, for a template. But, for a
10327 template <class T> void f ()
10328 { extern void g(int i = T()); }
10330 we should do the substitution when the template is
10331 instantiated. We handle the member function case in
10332 instantiate_class_template since the default arguments
10333 might refer to other members of the class. */
10335 && !PRIMARY_TEMPLATE_P (gen_tmpl)
10336 && !uses_template_parms (argvec))
10337 tsubst_default_arguments (r);
10340 DECL_TEMPLATE_INFO (r) = NULL_TREE;
10342 /* Copy the list of befriending classes. */
10343 for (friends = &DECL_BEFRIENDING_CLASSES (r);
10345 friends = &TREE_CHAIN (*friends))
10347 *friends = copy_node (*friends);
10348 TREE_VALUE (*friends) = tsubst (TREE_VALUE (*friends),
10353 if (DECL_CONSTRUCTOR_P (r) || DECL_DESTRUCTOR_P (r))
10355 maybe_retrofit_in_chrg (r);
10356 if (DECL_CONSTRUCTOR_P (r))
10357 grok_ctor_properties (ctx, r);
10358 /* If this is an instantiation of a member template, clone it.
10359 If it isn't, that'll be handled by
10360 clone_constructors_and_destructors. */
10361 if (PRIMARY_TEMPLATE_P (gen_tmpl))
10362 clone_function_decl (r, /*update_method_vec_p=*/0);
10364 else if ((complain & tf_error) != 0
10365 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
10366 && !grok_op_properties (r, /*complain=*/true))
10367 RETURN (error_mark_node);
10369 if (DECL_FRIEND_P (t) && DECL_FRIEND_CONTEXT (t))
10370 SET_DECL_FRIEND_CONTEXT (r,
10371 tsubst (DECL_FRIEND_CONTEXT (t),
10372 args, complain, in_decl));
10374 /* Possibly limit visibility based on template args. */
10375 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
10376 if (DECL_VISIBILITY_SPECIFIED (t))
10378 DECL_VISIBILITY_SPECIFIED (r) = 0;
10379 DECL_ATTRIBUTES (r)
10380 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
10382 determine_visibility (r);
10383 if (DECL_DEFAULTED_OUTSIDE_CLASS_P (r)
10384 && !processing_template_decl)
10385 defaulted_late_check (r);
10387 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
10388 args, complain, in_decl);
10394 tree type = NULL_TREE;
10396 tree expanded_types = NULL_TREE;
10397 tree prev_r = NULL_TREE;
10398 tree first_r = NULL_TREE;
10400 if (FUNCTION_PARAMETER_PACK_P (t))
10402 /* If there is a local specialization that isn't a
10403 parameter pack, it means that we're doing a "simple"
10404 substitution from inside tsubst_pack_expansion. Just
10405 return the local specialization (which will be a single
10407 tree spec = retrieve_local_specialization (t);
10409 && TREE_CODE (spec) == PARM_DECL
10410 && TREE_CODE (TREE_TYPE (spec)) != TYPE_PACK_EXPANSION)
10413 /* Expand the TYPE_PACK_EXPANSION that provides the types for
10414 the parameters in this function parameter pack. */
10415 expanded_types = tsubst_pack_expansion (TREE_TYPE (t), args,
10416 complain, in_decl);
10417 if (TREE_CODE (expanded_types) == TREE_VEC)
10419 len = TREE_VEC_LENGTH (expanded_types);
10421 /* Zero-length parameter packs are boring. Just substitute
10424 RETURN (tsubst (TREE_CHAIN (t), args, complain,
10429 /* All we did was update the type. Make a note of that. */
10430 type = expanded_types;
10431 expanded_types = NULL_TREE;
10435 /* Loop through all of the parameter's we'll build. When T is
10436 a function parameter pack, LEN is the number of expanded
10437 types in EXPANDED_TYPES; otherwise, LEN is 1. */
10439 for (i = 0; i < len; ++i)
10443 if (DECL_TEMPLATE_PARM_P (t))
10444 SET_DECL_TEMPLATE_PARM_P (r);
10446 if (expanded_types)
10447 /* We're on the Ith parameter of the function parameter
10450 /* An argument of a function parameter pack is not a parameter
10452 FUNCTION_PARAMETER_PACK_P (r) = false;
10454 /* Get the Ith type. */
10455 type = TREE_VEC_ELT (expanded_types, i);
10458 /* Rename the parameter to include the index. */
10460 make_ith_pack_parameter_name (DECL_NAME (r), i);
10463 /* We're dealing with a normal parameter. */
10464 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10466 type = type_decays_to (type);
10467 TREE_TYPE (r) = type;
10468 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
10470 if (DECL_INITIAL (r))
10472 if (TREE_CODE (DECL_INITIAL (r)) != TEMPLATE_PARM_INDEX)
10473 DECL_INITIAL (r) = TREE_TYPE (r);
10475 DECL_INITIAL (r) = tsubst (DECL_INITIAL (r), args,
10476 complain, in_decl);
10479 DECL_CONTEXT (r) = NULL_TREE;
10481 if (!DECL_TEMPLATE_PARM_P (r))
10482 DECL_ARG_TYPE (r) = type_passed_as (type);
10484 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
10485 args, complain, in_decl);
10487 /* Keep track of the first new parameter we
10488 generate. That's what will be returned to the
10493 /* Build a proper chain of parameters when substituting
10494 into a function parameter pack. */
10496 DECL_CHAIN (prev_r) = r;
10499 if (DECL_CHAIN (t))
10500 DECL_CHAIN (r) = tsubst (DECL_CHAIN (t), args,
10501 complain, DECL_CHAIN (t));
10503 /* FIRST_R contains the start of the chain we've built. */
10513 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10514 if (type == error_mark_node)
10515 RETURN (error_mark_node);
10516 TREE_TYPE (r) = type;
10517 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
10519 if (DECL_C_BIT_FIELD (r))
10520 /* For bit-fields, DECL_INITIAL gives the number of bits. For
10521 non-bit-fields DECL_INITIAL is a non-static data member
10522 initializer, which gets deferred instantiation. */
10524 = tsubst_expr (DECL_INITIAL (t), args,
10526 /*integral_constant_expression_p=*/true);
10527 else if (DECL_INITIAL (t))
10529 /* Set up DECL_TEMPLATE_INFO so that we can get at the
10530 NSDMI in perform_member_init. Still set DECL_INITIAL
10531 so that we know there is one. */
10532 DECL_INITIAL (r) = void_zero_node;
10533 gcc_assert (DECL_LANG_SPECIFIC (r) == NULL);
10534 retrofit_lang_decl (r);
10535 DECL_TEMPLATE_INFO (r) = build_template_info (t, args);
10537 /* We don't have to set DECL_CONTEXT here; it is set by
10538 finish_member_declaration. */
10539 DECL_CHAIN (r) = NULL_TREE;
10540 if (VOID_TYPE_P (type))
10541 error ("instantiation of %q+D as type %qT", r, type);
10543 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
10544 args, complain, in_decl);
10549 /* We reach here only for member using decls. */
10550 if (DECL_DEPENDENT_P (t))
10552 r = do_class_using_decl
10553 (tsubst_copy (USING_DECL_SCOPE (t), args, complain, in_decl),
10554 tsubst_copy (DECL_NAME (t), args, complain, in_decl));
10556 r = error_mark_node;
10559 TREE_PROTECTED (r) = TREE_PROTECTED (t);
10560 TREE_PRIVATE (r) = TREE_PRIVATE (t);
10566 DECL_CHAIN (r) = NULL_TREE;
10573 tree argvec = NULL_TREE;
10574 tree gen_tmpl = NULL_TREE;
10576 tree tmpl = NULL_TREE;
10578 tree type = NULL_TREE;
10581 if (TREE_CODE (t) == TYPE_DECL
10582 && t == TYPE_MAIN_DECL (TREE_TYPE (t)))
10584 /* If this is the canonical decl, we don't have to
10585 mess with instantiations, and often we can't (for
10586 typename, template type parms and such). Note that
10587 TYPE_NAME is not correct for the above test if
10588 we've copied the type for a typedef. */
10589 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10590 if (type == error_mark_node)
10591 RETURN (error_mark_node);
10592 r = TYPE_NAME (type);
10596 /* Check to see if we already have the specialization we
10599 if (DECL_CLASS_SCOPE_P (t) || DECL_NAMESPACE_SCOPE_P (t))
10601 /* T is a static data member or namespace-scope entity.
10602 We have to substitute into namespace-scope variables
10603 (even though such entities are never templates) because
10606 template <class T> void f() { extern T t; }
10608 where the entity referenced is not known until
10609 instantiation time. */
10611 ctx = DECL_CONTEXT (t);
10612 if (DECL_CLASS_SCOPE_P (t))
10614 ctx = tsubst_aggr_type (ctx, args,
10616 in_decl, /*entering_scope=*/1);
10617 /* If CTX is unchanged, then T is in fact the
10618 specialization we want. That situation occurs when
10619 referencing a static data member within in its own
10620 class. We can use pointer equality, rather than
10621 same_type_p, because DECL_CONTEXT is always
10623 if (ctx == DECL_CONTEXT (t)
10624 && (TREE_CODE (t) != TYPE_DECL
10625 /* ... unless T is a member template; in which
10626 case our caller can be willing to create a
10627 specialization of that template represented
10629 || !(DECL_TI_TEMPLATE (t)
10630 && DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (t)))))
10636 tmpl = DECL_TI_TEMPLATE (t);
10637 gen_tmpl = most_general_template (tmpl);
10638 argvec = tsubst (DECL_TI_ARGS (t), args, complain, in_decl);
10639 hash = hash_tmpl_and_args (gen_tmpl, argvec);
10640 spec = retrieve_specialization (gen_tmpl, argvec, hash);
10645 /* A local variable. */
10647 /* Subsequent calls to pushdecl will fill this in. */
10649 spec = retrieve_local_specialization (t);
10651 /* If we already have the specialization we need, there is
10652 nothing more to do. */
10659 /* Create a new node for the specialization we need. */
10661 if (type == NULL_TREE)
10663 if (is_typedef_decl (t))
10664 type = DECL_ORIGINAL_TYPE (t);
10666 type = TREE_TYPE (t);
10667 if (TREE_CODE (t) == VAR_DECL
10668 && VAR_HAD_UNKNOWN_BOUND (t)
10669 && type != error_mark_node)
10670 type = strip_array_domain (type);
10671 type = tsubst (type, args, complain, in_decl);
10673 if (TREE_CODE (r) == VAR_DECL)
10675 /* Even if the original location is out of scope, the
10676 newly substituted one is not. */
10677 DECL_DEAD_FOR_LOCAL (r) = 0;
10678 DECL_INITIALIZED_P (r) = 0;
10679 DECL_TEMPLATE_INSTANTIATED (r) = 0;
10680 if (type == error_mark_node)
10681 RETURN (error_mark_node);
10682 if (TREE_CODE (type) == FUNCTION_TYPE)
10684 /* It may seem that this case cannot occur, since:
10689 declares a function, not a variable. However:
10692 template <typename T> void g() { T t; }
10693 template void g<f>();
10695 is an attempt to declare a variable with function
10697 error ("variable %qD has function type",
10698 /* R is not yet sufficiently initialized, so we
10699 just use its name. */
10701 RETURN (error_mark_node);
10703 type = complete_type (type);
10704 /* Wait until cp_finish_decl to set this again, to handle
10705 circular dependency (template/instantiate6.C). */
10706 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r) = 0;
10707 type = check_var_type (DECL_NAME (r), type);
10709 if (DECL_HAS_VALUE_EXPR_P (t))
10711 tree ve = DECL_VALUE_EXPR (t);
10712 ve = tsubst_expr (ve, args, complain, in_decl,
10713 /*constant_expression_p=*/false);
10714 if (REFERENCE_REF_P (ve))
10716 gcc_assert (TREE_CODE (type) == REFERENCE_TYPE);
10717 ve = TREE_OPERAND (ve, 0);
10719 SET_DECL_VALUE_EXPR (r, ve);
10722 else if (DECL_SELF_REFERENCE_P (t))
10723 SET_DECL_SELF_REFERENCE_P (r);
10724 TREE_TYPE (r) = type;
10725 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
10726 DECL_CONTEXT (r) = ctx;
10727 /* Clear out the mangled name and RTL for the instantiation. */
10728 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
10729 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
10730 SET_DECL_RTL (r, NULL);
10731 /* The initializer must not be expanded until it is required;
10732 see [temp.inst]. */
10733 DECL_INITIAL (r) = NULL_TREE;
10734 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
10735 SET_DECL_RTL (r, NULL);
10736 DECL_SIZE (r) = DECL_SIZE_UNIT (r) = 0;
10737 if (TREE_CODE (r) == VAR_DECL)
10739 /* Possibly limit visibility based on template args. */
10740 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
10741 if (DECL_VISIBILITY_SPECIFIED (t))
10743 DECL_VISIBILITY_SPECIFIED (r) = 0;
10744 DECL_ATTRIBUTES (r)
10745 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
10747 determine_visibility (r);
10752 /* A static data member declaration is always marked
10753 external when it is declared in-class, even if an
10754 initializer is present. We mimic the non-template
10755 processing here. */
10756 DECL_EXTERNAL (r) = 1;
10758 register_specialization (r, gen_tmpl, argvec, false, hash);
10759 DECL_TEMPLATE_INFO (r) = build_template_info (tmpl, argvec);
10760 SET_DECL_IMPLICIT_INSTANTIATION (r);
10762 else if (cp_unevaluated_operand)
10764 /* We're substituting this var in a decltype outside of its
10765 scope, such as for a lambda return type. Don't add it to
10766 local_specializations, do perform auto deduction. */
10767 tree auto_node = type_uses_auto (type);
10771 = tsubst_expr (DECL_INITIAL (t), args, complain, in_decl,
10772 /*constant_expression_p=*/false);
10773 init = resolve_nondeduced_context (init);
10774 TREE_TYPE (r) = type
10775 = do_auto_deduction (type, init, auto_node);
10779 register_local_specialization (r, t);
10781 DECL_CHAIN (r) = NULL_TREE;
10783 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r),
10785 args, complain, in_decl);
10787 /* Preserve a typedef that names a type. */
10788 if (is_typedef_decl (r))
10790 DECL_ORIGINAL_TYPE (r) = NULL_TREE;
10791 set_underlying_type (r);
10794 layout_decl (r, 0);
10799 gcc_unreachable ();
10804 /* Restore the file and line information. */
10805 input_location = saved_loc;
10810 /* Substitute into the ARG_TYPES of a function type. */
10813 tsubst_arg_types (tree arg_types,
10815 tsubst_flags_t complain,
10818 tree remaining_arg_types;
10819 tree type = NULL_TREE;
10821 tree expanded_args = NULL_TREE;
10824 if (!arg_types || arg_types == void_list_node)
10827 remaining_arg_types = tsubst_arg_types (TREE_CHAIN (arg_types),
10828 args, complain, in_decl);
10829 if (remaining_arg_types == error_mark_node)
10830 return error_mark_node;
10832 if (PACK_EXPANSION_P (TREE_VALUE (arg_types)))
10834 /* For a pack expansion, perform substitution on the
10835 entire expression. Later on, we'll handle the arguments
10837 expanded_args = tsubst_pack_expansion (TREE_VALUE (arg_types),
10838 args, complain, in_decl);
10840 if (TREE_CODE (expanded_args) == TREE_VEC)
10841 /* So that we'll spin through the parameters, one by one. */
10842 i = TREE_VEC_LENGTH (expanded_args);
10845 /* We only partially substituted into the parameter
10846 pack. Our type is TYPE_PACK_EXPANSION. */
10847 type = expanded_args;
10848 expanded_args = NULL_TREE;
10856 type = TREE_VEC_ELT (expanded_args, i);
10858 type = tsubst (TREE_VALUE (arg_types), args, complain, in_decl);
10860 if (type == error_mark_node)
10861 return error_mark_node;
10862 if (VOID_TYPE_P (type))
10864 if (complain & tf_error)
10866 error ("invalid parameter type %qT", type);
10868 error ("in declaration %q+D", in_decl);
10870 return error_mark_node;
10873 /* Do array-to-pointer, function-to-pointer conversion, and ignore
10874 top-level qualifiers as required. */
10875 type = cv_unqualified (type_decays_to (type));
10877 /* We do not substitute into default arguments here. The standard
10878 mandates that they be instantiated only when needed, which is
10879 done in build_over_call. */
10880 default_arg = TREE_PURPOSE (arg_types);
10882 if (default_arg && TREE_CODE (default_arg) == DEFAULT_ARG)
10884 /* We've instantiated a template before its default arguments
10885 have been parsed. This can happen for a nested template
10886 class, and is not an error unless we require the default
10887 argument in a call of this function. */
10888 remaining_arg_types =
10889 tree_cons (default_arg, type, remaining_arg_types);
10890 VEC_safe_push (tree, gc, DEFARG_INSTANTIATIONS (default_arg),
10891 remaining_arg_types);
10894 remaining_arg_types =
10895 hash_tree_cons (default_arg, type, remaining_arg_types);
10898 return remaining_arg_types;
10901 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
10902 *not* handle the exception-specification for FNTYPE, because the
10903 initial substitution of explicitly provided template parameters
10904 during argument deduction forbids substitution into the
10905 exception-specification:
10909 All references in the function type of the function template to the
10910 corresponding template parameters are replaced by the specified tem-
10911 plate argument values. If a substitution in a template parameter or
10912 in the function type of the function template results in an invalid
10913 type, type deduction fails. [Note: The equivalent substitution in
10914 exception specifications is done only when the function is instanti-
10915 ated, at which point a program is ill-formed if the substitution
10916 results in an invalid type.] */
10919 tsubst_function_type (tree t,
10921 tsubst_flags_t complain,
10928 /* The TYPE_CONTEXT is not used for function/method types. */
10929 gcc_assert (TYPE_CONTEXT (t) == NULL_TREE);
10931 /* Substitute the return type. */
10932 return_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10933 if (return_type == error_mark_node)
10934 return error_mark_node;
10935 /* The standard does not presently indicate that creation of a
10936 function type with an invalid return type is a deduction failure.
10937 However, that is clearly analogous to creating an array of "void"
10938 or a reference to a reference. This is core issue #486. */
10939 if (TREE_CODE (return_type) == ARRAY_TYPE
10940 || TREE_CODE (return_type) == FUNCTION_TYPE)
10942 if (complain & tf_error)
10944 if (TREE_CODE (return_type) == ARRAY_TYPE)
10945 error ("function returning an array");
10947 error ("function returning a function");
10949 return error_mark_node;
10952 /* Substitute the argument types. */
10953 arg_types = tsubst_arg_types (TYPE_ARG_TYPES (t), args,
10954 complain, in_decl);
10955 if (arg_types == error_mark_node)
10956 return error_mark_node;
10958 /* Construct a new type node and return it. */
10959 if (TREE_CODE (t) == FUNCTION_TYPE)
10961 fntype = build_function_type (return_type, arg_types);
10962 fntype = apply_memfn_quals (fntype, type_memfn_quals (t));
10966 tree r = TREE_TYPE (TREE_VALUE (arg_types));
10967 if (! MAYBE_CLASS_TYPE_P (r))
10971 Type deduction may fail for any of the following
10974 -- Attempting to create "pointer to member of T" when T
10975 is not a class type. */
10976 if (complain & tf_error)
10977 error ("creating pointer to member function of non-class type %qT",
10979 return error_mark_node;
10982 fntype = build_method_type_directly (r, return_type,
10983 TREE_CHAIN (arg_types));
10985 fntype = cp_build_type_attribute_variant (fntype, TYPE_ATTRIBUTES (t));
10990 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
10991 ARGS into that specification, and return the substituted
10992 specification. If there is no specification, return NULL_TREE. */
10995 tsubst_exception_specification (tree fntype,
10997 tsubst_flags_t complain,
11004 specs = TYPE_RAISES_EXCEPTIONS (fntype);
11005 new_specs = NULL_TREE;
11006 if (specs && TREE_PURPOSE (specs))
11008 /* A noexcept-specifier. */
11009 tree expr = TREE_PURPOSE (specs);
11010 if (expr == boolean_true_node || expr == boolean_false_node)
11014 /* Defer instantiation of noexcept-specifiers to avoid
11015 excessive instantiations (c++/49107). */
11016 new_specs = make_node (DEFERRED_NOEXCEPT);
11017 if (DEFERRED_NOEXCEPT_SPEC_P (specs))
11019 /* We already partially instantiated this member template,
11020 so combine the new args with the old. */
11021 DEFERRED_NOEXCEPT_PATTERN (new_specs)
11022 = DEFERRED_NOEXCEPT_PATTERN (expr);
11023 DEFERRED_NOEXCEPT_ARGS (new_specs)
11024 = add_to_template_args (DEFERRED_NOEXCEPT_ARGS (expr), args);
11028 DEFERRED_NOEXCEPT_PATTERN (new_specs) = expr;
11029 DEFERRED_NOEXCEPT_ARGS (new_specs) = args;
11033 new_specs = tsubst_copy_and_build
11034 (expr, args, complain, in_decl, /*function_p=*/false,
11035 /*integral_constant_expression_p=*/true);
11036 new_specs = build_noexcept_spec (new_specs, complain);
11040 if (! TREE_VALUE (specs))
11047 tree expanded_specs = NULL_TREE;
11049 if (PACK_EXPANSION_P (TREE_VALUE (specs)))
11051 /* Expand the pack expansion type. */
11052 expanded_specs = tsubst_pack_expansion (TREE_VALUE (specs),
11056 if (expanded_specs == error_mark_node)
11057 return error_mark_node;
11058 else if (TREE_CODE (expanded_specs) == TREE_VEC)
11059 len = TREE_VEC_LENGTH (expanded_specs);
11062 /* We're substituting into a member template, so
11063 we got a TYPE_PACK_EXPANSION back. Add that
11064 expansion and move on. */
11065 gcc_assert (TREE_CODE (expanded_specs)
11066 == TYPE_PACK_EXPANSION);
11067 new_specs = add_exception_specifier (new_specs,
11070 specs = TREE_CHAIN (specs);
11075 for (i = 0; i < len; ++i)
11077 if (expanded_specs)
11078 spec = TREE_VEC_ELT (expanded_specs, i);
11080 spec = tsubst (TREE_VALUE (specs), args, complain, in_decl);
11081 if (spec == error_mark_node)
11083 new_specs = add_exception_specifier (new_specs, spec,
11087 specs = TREE_CHAIN (specs);
11093 /* Take the tree structure T and replace template parameters used
11094 therein with the argument vector ARGS. IN_DECL is an associated
11095 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
11096 Issue error and warning messages under control of COMPLAIN. Note
11097 that we must be relatively non-tolerant of extensions here, in
11098 order to preserve conformance; if we allow substitutions that
11099 should not be allowed, we may allow argument deductions that should
11100 not succeed, and therefore report ambiguous overload situations
11101 where there are none. In theory, we could allow the substitution,
11102 but indicate that it should have failed, and allow our caller to
11103 make sure that the right thing happens, but we don't try to do this
11106 This function is used for dealing with types, decls and the like;
11107 for expressions, use tsubst_expr or tsubst_copy. */
11110 tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl)
11112 enum tree_code code;
11113 tree type, r = NULL_TREE;
11115 if (t == NULL_TREE || t == error_mark_node
11116 || t == integer_type_node
11117 || t == void_type_node
11118 || t == char_type_node
11119 || t == unknown_type_node
11120 || TREE_CODE (t) == NAMESPACE_DECL
11121 || TREE_CODE (t) == TRANSLATION_UNIT_DECL)
11125 return tsubst_decl (t, args, complain);
11127 if (args == NULL_TREE)
11130 code = TREE_CODE (t);
11132 if (code == IDENTIFIER_NODE)
11133 type = IDENTIFIER_TYPE_VALUE (t);
11135 type = TREE_TYPE (t);
11137 gcc_assert (type != unknown_type_node);
11139 /* Reuse typedefs. We need to do this to handle dependent attributes,
11140 such as attribute aligned. */
11142 && typedef_variant_p (t))
11144 tree decl = TYPE_NAME (t);
11146 if (TYPE_DECL_ALIAS_P (decl)
11147 && DECL_LANG_SPECIFIC (decl)
11148 && DECL_TEMPLATE_INFO (decl)
11149 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (decl)))
11151 /* DECL represents an alias template and we want to
11152 instantiate it. Let's substitute our arguments for the
11153 template parameters into the declaration and get the
11155 r = tsubst (decl, args, complain, decl);
11157 else if (DECL_CLASS_SCOPE_P (decl)
11158 && CLASSTYPE_TEMPLATE_INFO (DECL_CONTEXT (decl))
11159 && uses_template_parms (DECL_CONTEXT (decl)))
11161 tree tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
11162 tree gen_args = tsubst (DECL_TI_ARGS (decl), args, complain, in_decl);
11163 r = retrieve_specialization (tmpl, gen_args, 0);
11165 else if (DECL_FUNCTION_SCOPE_P (decl)
11166 && DECL_TEMPLATE_INFO (DECL_CONTEXT (decl))
11167 && uses_template_parms (DECL_TI_ARGS (DECL_CONTEXT (decl))))
11168 r = retrieve_local_specialization (decl);
11170 /* The typedef is from a non-template context. */
11176 r = cp_build_qualified_type_real
11177 (r, cp_type_quals (t) | cp_type_quals (r),
11178 complain | tf_ignore_bad_quals);
11182 /* We don't have an instantiation yet, so drop the typedef. */
11183 t = DECL_ORIGINAL_TYPE (decl);
11187 && code != TYPENAME_TYPE
11188 && code != TEMPLATE_TYPE_PARM
11189 && code != IDENTIFIER_NODE
11190 && code != FUNCTION_TYPE
11191 && code != METHOD_TYPE)
11192 type = tsubst (type, args, complain, in_decl);
11193 if (type == error_mark_node)
11194 return error_mark_node;
11200 case ENUMERAL_TYPE:
11201 return tsubst_aggr_type (t, args, complain, in_decl,
11202 /*entering_scope=*/0);
11205 case IDENTIFIER_NODE:
11216 if (t == integer_type_node)
11219 if (TREE_CODE (TYPE_MIN_VALUE (t)) == INTEGER_CST
11220 && TREE_CODE (TYPE_MAX_VALUE (t)) == INTEGER_CST)
11224 tree max, omax = TREE_OPERAND (TYPE_MAX_VALUE (t), 0);
11226 max = tsubst_expr (omax, args, complain, in_decl,
11227 /*integral_constant_expression_p=*/false);
11229 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
11231 if (TREE_CODE (max) == NOP_EXPR
11232 && TREE_SIDE_EFFECTS (omax)
11233 && !TREE_TYPE (max))
11234 TREE_TYPE (max) = TREE_TYPE (TREE_OPERAND (max, 0));
11236 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
11237 with TREE_SIDE_EFFECTS that indicates this is not an integral
11238 constant expression. */
11239 if (processing_template_decl
11240 && TREE_SIDE_EFFECTS (omax) && TREE_CODE (omax) == NOP_EXPR)
11242 gcc_assert (TREE_CODE (max) == NOP_EXPR);
11243 TREE_SIDE_EFFECTS (max) = 1;
11246 return compute_array_index_type (NULL_TREE, max, complain);
11249 case TEMPLATE_TYPE_PARM:
11250 case TEMPLATE_TEMPLATE_PARM:
11251 case BOUND_TEMPLATE_TEMPLATE_PARM:
11252 case TEMPLATE_PARM_INDEX:
11257 tree arg = NULL_TREE;
11261 gcc_assert (TREE_VEC_LENGTH (args) > 0);
11262 template_parm_level_and_index (t, &level, &idx);
11264 levels = TMPL_ARGS_DEPTH (args);
11265 if (level <= levels)
11267 arg = TMPL_ARG (args, level, idx);
11269 if (arg && TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
11270 /* See through ARGUMENT_PACK_SELECT arguments. */
11271 arg = ARGUMENT_PACK_SELECT_ARG (arg);
11274 if (arg == error_mark_node)
11275 return error_mark_node;
11276 else if (arg != NULL_TREE)
11278 if (ARGUMENT_PACK_P (arg))
11279 /* If ARG is an argument pack, we don't actually want to
11280 perform a substitution here, because substitutions
11281 for argument packs are only done
11282 element-by-element. We can get to this point when
11283 substituting the type of a non-type template
11284 parameter pack, when that type actually contains
11285 template parameter packs from an outer template, e.g.,
11287 template<typename... Types> struct A {
11288 template<Types... Values> struct B { };
11292 if (code == TEMPLATE_TYPE_PARM)
11295 gcc_assert (TYPE_P (arg));
11297 quals = cp_type_quals (arg) | cp_type_quals (t);
11299 return cp_build_qualified_type_real
11300 (arg, quals, complain | tf_ignore_bad_quals);
11302 else if (code == BOUND_TEMPLATE_TEMPLATE_PARM)
11304 /* We are processing a type constructed from a
11305 template template parameter. */
11306 tree argvec = tsubst (TYPE_TI_ARGS (t),
11307 args, complain, in_decl);
11308 if (argvec == error_mark_node)
11309 return error_mark_node;
11311 gcc_assert (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
11312 || TREE_CODE (arg) == TEMPLATE_DECL
11313 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE);
11315 if (TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE)
11316 /* Consider this code:
11318 template <template <class> class Template>
11320 template <class Arg> using Bind = Template<Arg>;
11323 template <template <class> class Template, class Arg>
11324 using Instantiate = Template<Arg>; //#0
11326 template <template <class> class Template,
11329 Instantiate<Internal<Template>::template Bind,
11332 When #1 is parsed, the
11333 BOUND_TEMPLATE_TEMPLATE_PARM representing the
11334 parameter `Template' in #0 matches the
11335 UNBOUND_CLASS_TEMPLATE representing the argument
11336 `Internal<Template>::template Bind'; We then want
11337 to assemble the type `Bind<Argument>' that can't
11338 be fully created right now, because
11339 `Internal<Template>' not being complete, the Bind
11340 template cannot be looked up in that context. So
11341 we need to "store" `Bind<Argument>' for later
11342 when the context of Bind becomes complete. Let's
11343 store that in a TYPENAME_TYPE. */
11344 return make_typename_type (TYPE_CONTEXT (arg),
11345 build_nt (TEMPLATE_ID_EXPR,
11346 TYPE_IDENTIFIER (arg),
11351 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
11352 are resolving nested-types in the signature of a
11353 member function templates. Otherwise ARG is a
11354 TEMPLATE_DECL and is the real template to be
11356 if (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
11357 arg = TYPE_NAME (arg);
11359 r = lookup_template_class (arg,
11361 DECL_CONTEXT (arg),
11362 /*entering_scope=*/0,
11364 return cp_build_qualified_type_real
11365 (r, cp_type_quals (t), complain);
11368 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
11369 return convert_from_reference (unshare_expr (arg));
11373 /* This can happen during the attempted tsubst'ing in
11374 unify. This means that we don't yet have any information
11375 about the template parameter in question. */
11378 /* If we get here, we must have been looking at a parm for a
11379 more deeply nested template. Make a new version of this
11380 template parameter, but with a lower level. */
11383 case TEMPLATE_TYPE_PARM:
11384 case TEMPLATE_TEMPLATE_PARM:
11385 case BOUND_TEMPLATE_TEMPLATE_PARM:
11386 if (cp_type_quals (t))
11388 r = tsubst (TYPE_MAIN_VARIANT (t), args, complain, in_decl);
11389 r = cp_build_qualified_type_real
11390 (r, cp_type_quals (t),
11391 complain | (code == TEMPLATE_TYPE_PARM
11392 ? tf_ignore_bad_quals : 0));
11397 TEMPLATE_TYPE_PARM_INDEX (r)
11398 = reduce_template_parm_level (TEMPLATE_TYPE_PARM_INDEX (t),
11399 r, levels, args, complain);
11400 TYPE_STUB_DECL (r) = TYPE_NAME (r) = TEMPLATE_TYPE_DECL (r);
11401 TYPE_MAIN_VARIANT (r) = r;
11402 TYPE_POINTER_TO (r) = NULL_TREE;
11403 TYPE_REFERENCE_TO (r) = NULL_TREE;
11405 if (TREE_CODE (r) == TEMPLATE_TEMPLATE_PARM)
11406 /* We have reduced the level of the template
11407 template parameter, but not the levels of its
11408 template parameters, so canonical_type_parameter
11409 will not be able to find the canonical template
11410 template parameter for this level. Thus, we
11411 require structural equality checking to compare
11412 TEMPLATE_TEMPLATE_PARMs. */
11413 SET_TYPE_STRUCTURAL_EQUALITY (r);
11414 else if (TYPE_STRUCTURAL_EQUALITY_P (t))
11415 SET_TYPE_STRUCTURAL_EQUALITY (r);
11417 TYPE_CANONICAL (r) = canonical_type_parameter (r);
11419 if (code == BOUND_TEMPLATE_TEMPLATE_PARM)
11421 tree argvec = tsubst (TYPE_TI_ARGS (t), args,
11422 complain, in_decl);
11423 if (argvec == error_mark_node)
11424 return error_mark_node;
11426 TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (r)
11427 = build_template_info (TYPE_TI_TEMPLATE (t), argvec);
11432 case TEMPLATE_PARM_INDEX:
11433 r = reduce_template_parm_level (t, type, levels, args, complain);
11437 gcc_unreachable ();
11445 tree purpose, value, chain;
11447 if (t == void_list_node)
11450 purpose = TREE_PURPOSE (t);
11453 purpose = tsubst (purpose, args, complain, in_decl);
11454 if (purpose == error_mark_node)
11455 return error_mark_node;
11457 value = TREE_VALUE (t);
11460 value = tsubst (value, args, complain, in_decl);
11461 if (value == error_mark_node)
11462 return error_mark_node;
11464 chain = TREE_CHAIN (t);
11465 if (chain && chain != void_type_node)
11467 chain = tsubst (chain, args, complain, in_decl);
11468 if (chain == error_mark_node)
11469 return error_mark_node;
11471 if (purpose == TREE_PURPOSE (t)
11472 && value == TREE_VALUE (t)
11473 && chain == TREE_CHAIN (t))
11475 return hash_tree_cons (purpose, value, chain);
11479 /* We should never be tsubsting a binfo. */
11480 gcc_unreachable ();
11483 /* A vector of template arguments. */
11484 gcc_assert (!type);
11485 return tsubst_template_args (t, args, complain, in_decl);
11488 case REFERENCE_TYPE:
11490 if (type == TREE_TYPE (t) && TREE_CODE (type) != METHOD_TYPE)
11495 Type deduction may fail for any of the following
11498 -- Attempting to create a pointer to reference type.
11499 -- Attempting to create a reference to a reference type or
11500 a reference to void.
11502 Core issue 106 says that creating a reference to a reference
11503 during instantiation is no longer a cause for failure. We
11504 only enforce this check in strict C++98 mode. */
11505 if ((TREE_CODE (type) == REFERENCE_TYPE
11506 && (((cxx_dialect == cxx98) && flag_iso) || code != REFERENCE_TYPE))
11507 || (code == REFERENCE_TYPE && TREE_CODE (type) == VOID_TYPE))
11509 static location_t last_loc;
11511 /* We keep track of the last time we issued this error
11512 message to avoid spewing a ton of messages during a
11513 single bad template instantiation. */
11514 if (complain & tf_error
11515 && last_loc != input_location)
11517 if (TREE_CODE (type) == VOID_TYPE)
11518 error ("forming reference to void");
11519 else if (code == POINTER_TYPE)
11520 error ("forming pointer to reference type %qT", type);
11522 error ("forming reference to reference type %qT", type);
11523 last_loc = input_location;
11526 return error_mark_node;
11528 else if (code == POINTER_TYPE)
11530 r = build_pointer_type (type);
11531 if (TREE_CODE (type) == METHOD_TYPE)
11532 r = build_ptrmemfunc_type (r);
11534 else if (TREE_CODE (type) == REFERENCE_TYPE)
11535 /* In C++0x, during template argument substitution, when there is an
11536 attempt to create a reference to a reference type, reference
11537 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
11539 "If a template-argument for a template-parameter T names a type
11540 that is a reference to a type A, an attempt to create the type
11541 'lvalue reference to cv T' creates the type 'lvalue reference to
11542 A,' while an attempt to create the type type rvalue reference to
11543 cv T' creates the type T"
11545 r = cp_build_reference_type
11547 TYPE_REF_IS_RVALUE (t) && TYPE_REF_IS_RVALUE (type));
11549 r = cp_build_reference_type (type, TYPE_REF_IS_RVALUE (t));
11550 r = cp_build_qualified_type_real (r, cp_type_quals (t), complain);
11552 if (r != error_mark_node)
11553 /* Will this ever be needed for TYPE_..._TO values? */
11560 r = tsubst (TYPE_OFFSET_BASETYPE (t), args, complain, in_decl);
11561 if (r == error_mark_node || !MAYBE_CLASS_TYPE_P (r))
11565 Type deduction may fail for any of the following
11568 -- Attempting to create "pointer to member of T" when T
11569 is not a class type. */
11570 if (complain & tf_error)
11571 error ("creating pointer to member of non-class type %qT", r);
11572 return error_mark_node;
11574 if (TREE_CODE (type) == REFERENCE_TYPE)
11576 if (complain & tf_error)
11577 error ("creating pointer to member reference type %qT", type);
11578 return error_mark_node;
11580 if (TREE_CODE (type) == VOID_TYPE)
11582 if (complain & tf_error)
11583 error ("creating pointer to member of type void");
11584 return error_mark_node;
11586 gcc_assert (TREE_CODE (type) != METHOD_TYPE);
11587 if (TREE_CODE (type) == FUNCTION_TYPE)
11589 /* The type of the implicit object parameter gets its
11590 cv-qualifiers from the FUNCTION_TYPE. */
11592 tree method_type = build_memfn_type (type, r, type_memfn_quals (type));
11593 memptr = build_ptrmemfunc_type (build_pointer_type (method_type));
11594 return cp_build_qualified_type_real (memptr, cp_type_quals (t),
11598 return cp_build_qualified_type_real (build_ptrmem_type (r, type),
11602 case FUNCTION_TYPE:
11607 fntype = tsubst_function_type (t, args, complain, in_decl);
11608 if (fntype == error_mark_node)
11609 return error_mark_node;
11611 /* Substitute the exception specification. */
11612 specs = tsubst_exception_specification (t, args, complain,
11613 in_decl, /*defer_ok*/true);
11614 if (specs == error_mark_node)
11615 return error_mark_node;
11617 fntype = build_exception_variant (fntype, specs);
11622 tree domain = tsubst (TYPE_DOMAIN (t), args, complain, in_decl);
11623 if (domain == error_mark_node)
11624 return error_mark_node;
11626 /* As an optimization, we avoid regenerating the array type if
11627 it will obviously be the same as T. */
11628 if (type == TREE_TYPE (t) && domain == TYPE_DOMAIN (t))
11631 /* These checks should match the ones in grokdeclarator.
11635 The deduction may fail for any of the following reasons:
11637 -- Attempting to create an array with an element type that
11638 is void, a function type, or a reference type, or [DR337]
11639 an abstract class type. */
11640 if (TREE_CODE (type) == VOID_TYPE
11641 || TREE_CODE (type) == FUNCTION_TYPE
11642 || TREE_CODE (type) == REFERENCE_TYPE)
11644 if (complain & tf_error)
11645 error ("creating array of %qT", type);
11646 return error_mark_node;
11648 if (CLASS_TYPE_P (type) && CLASSTYPE_PURE_VIRTUALS (type))
11650 if (complain & tf_error)
11651 error ("creating array of %qT, which is an abstract class type",
11653 return error_mark_node;
11656 r = build_cplus_array_type (type, domain);
11658 if (TYPE_USER_ALIGN (t))
11660 TYPE_ALIGN (r) = TYPE_ALIGN (t);
11661 TYPE_USER_ALIGN (r) = 1;
11667 case TYPENAME_TYPE:
11669 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
11670 in_decl, /*entering_scope=*/1);
11671 tree f = tsubst_copy (TYPENAME_TYPE_FULLNAME (t), args,
11672 complain, in_decl);
11674 if (ctx == error_mark_node || f == error_mark_node)
11675 return error_mark_node;
11677 if (!MAYBE_CLASS_TYPE_P (ctx))
11679 if (complain & tf_error)
11680 error ("%qT is not a class, struct, or union type", ctx);
11681 return error_mark_node;
11683 else if (!uses_template_parms (ctx) && !TYPE_BEING_DEFINED (ctx))
11685 /* Normally, make_typename_type does not require that the CTX
11686 have complete type in order to allow things like:
11688 template <class T> struct S { typename S<T>::X Y; };
11690 But, such constructs have already been resolved by this
11691 point, so here CTX really should have complete type, unless
11692 it's a partial instantiation. */
11693 ctx = complete_type (ctx);
11694 if (!COMPLETE_TYPE_P (ctx))
11696 if (complain & tf_error)
11697 cxx_incomplete_type_error (NULL_TREE, ctx);
11698 return error_mark_node;
11702 f = make_typename_type (ctx, f, typename_type,
11703 (complain & tf_error) | tf_keep_type_decl);
11704 if (f == error_mark_node)
11706 if (TREE_CODE (f) == TYPE_DECL)
11708 complain |= tf_ignore_bad_quals;
11712 if (TREE_CODE (f) != TYPENAME_TYPE)
11714 if (TYPENAME_IS_ENUM_P (t) && TREE_CODE (f) != ENUMERAL_TYPE)
11716 if (complain & tf_error)
11717 error ("%qT resolves to %qT, which is not an enumeration type",
11720 return error_mark_node;
11722 else if (TYPENAME_IS_CLASS_P (t) && !CLASS_TYPE_P (f))
11724 if (complain & tf_error)
11725 error ("%qT resolves to %qT, which is is not a class type",
11728 return error_mark_node;
11732 return cp_build_qualified_type_real
11733 (f, cp_type_quals (f) | cp_type_quals (t), complain);
11736 case UNBOUND_CLASS_TEMPLATE:
11738 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
11739 in_decl, /*entering_scope=*/1);
11740 tree name = TYPE_IDENTIFIER (t);
11741 tree parm_list = DECL_TEMPLATE_PARMS (TYPE_NAME (t));
11743 if (ctx == error_mark_node || name == error_mark_node)
11744 return error_mark_node;
11747 parm_list = tsubst_template_parms (parm_list, args, complain);
11748 return make_unbound_class_template (ctx, name, parm_list, complain);
11755 ++cp_unevaluated_operand;
11756 ++c_inhibit_evaluation_warnings;
11758 type = tsubst_expr (TYPEOF_TYPE_EXPR (t), args,
11760 /*integral_constant_expression_p=*/false);
11762 --cp_unevaluated_operand;
11763 --c_inhibit_evaluation_warnings;
11765 type = finish_typeof (type);
11766 return cp_build_qualified_type_real (type,
11768 | cp_type_quals (type),
11772 case DECLTYPE_TYPE:
11776 ++cp_unevaluated_operand;
11777 ++c_inhibit_evaluation_warnings;
11779 type = tsubst_expr (DECLTYPE_TYPE_EXPR (t), args,
11781 /*integral_constant_expression_p=*/false);
11783 --cp_unevaluated_operand;
11784 --c_inhibit_evaluation_warnings;
11786 if (DECLTYPE_FOR_LAMBDA_CAPTURE (t))
11787 type = lambda_capture_field_type (type);
11788 else if (DECLTYPE_FOR_LAMBDA_PROXY (t))
11789 type = lambda_proxy_type (type);
11791 type = finish_decltype_type
11792 (type, DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t), complain);
11793 return cp_build_qualified_type_real (type,
11795 | cp_type_quals (type),
11799 case UNDERLYING_TYPE:
11801 tree type = tsubst (UNDERLYING_TYPE_TYPE (t), args,
11802 complain, in_decl);
11803 return finish_underlying_type (type);
11806 case TYPE_ARGUMENT_PACK:
11807 case NONTYPE_ARGUMENT_PACK:
11809 tree r = TYPE_P (t) ? cxx_make_type (code) : make_node (code);
11811 tsubst_template_args (ARGUMENT_PACK_ARGS (t),
11815 SET_ARGUMENT_PACK_ARGS (r, packed_out);
11817 /* For template nontype argument packs, also substitute into
11819 if (code == NONTYPE_ARGUMENT_PACK)
11820 TREE_TYPE (r) = tsubst (TREE_TYPE (t), args, complain, in_decl);
11838 /* We should use one of the expression tsubsts for these codes. */
11839 gcc_unreachable ();
11842 sorry ("use of %qs in template", tree_code_name [(int) code]);
11843 return error_mark_node;
11847 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
11848 type of the expression on the left-hand side of the "." or "->"
11852 tsubst_baselink (tree baselink, tree object_type,
11853 tree args, tsubst_flags_t complain, tree in_decl)
11856 tree qualifying_scope;
11859 tree template_args = 0;
11860 bool template_id_p = false;
11861 bool qualified = BASELINK_QUALIFIED_P (baselink);
11863 /* A baselink indicates a function from a base class. Both the
11864 BASELINK_ACCESS_BINFO and the base class referenced may
11865 indicate bases of the template class, rather than the
11866 instantiated class. In addition, lookups that were not
11867 ambiguous before may be ambiguous now. Therefore, we perform
11868 the lookup again. */
11869 qualifying_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (baselink));
11870 qualifying_scope = tsubst (qualifying_scope, args,
11871 complain, in_decl);
11872 fns = BASELINK_FUNCTIONS (baselink);
11873 optype = tsubst (BASELINK_OPTYPE (baselink), args, complain, in_decl);
11874 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
11876 template_id_p = true;
11877 template_args = TREE_OPERAND (fns, 1);
11878 fns = TREE_OPERAND (fns, 0);
11880 template_args = tsubst_template_args (template_args, args,
11881 complain, in_decl);
11883 name = DECL_NAME (get_first_fn (fns));
11884 if (IDENTIFIER_TYPENAME_P (name))
11885 name = mangle_conv_op_name_for_type (optype);
11886 baselink = lookup_fnfields (qualifying_scope, name, /*protect=*/1);
11888 return error_mark_node;
11890 /* If lookup found a single function, mark it as used at this
11891 point. (If it lookup found multiple functions the one selected
11892 later by overload resolution will be marked as used at that
11894 if (BASELINK_P (baselink))
11895 fns = BASELINK_FUNCTIONS (baselink);
11896 if (!template_id_p && !really_overloaded_fn (fns))
11897 mark_used (OVL_CURRENT (fns));
11899 /* Add back the template arguments, if present. */
11900 if (BASELINK_P (baselink) && template_id_p)
11901 BASELINK_FUNCTIONS (baselink)
11902 = build_nt (TEMPLATE_ID_EXPR,
11903 BASELINK_FUNCTIONS (baselink),
11905 /* Update the conversion operator type. */
11906 BASELINK_OPTYPE (baselink) = optype;
11909 object_type = current_class_type;
11912 baselink = adjust_result_of_qualified_name_lookup (baselink,
11918 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
11919 true if the qualified-id will be a postfix-expression in-and-of
11920 itself; false if more of the postfix-expression follows the
11921 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
11925 tsubst_qualified_id (tree qualified_id, tree args,
11926 tsubst_flags_t complain, tree in_decl,
11927 bool done, bool address_p)
11933 tree template_args;
11935 gcc_assert (TREE_CODE (qualified_id) == SCOPE_REF);
11937 /* Figure out what name to look up. */
11938 name = TREE_OPERAND (qualified_id, 1);
11939 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
11941 is_template = true;
11942 template_args = TREE_OPERAND (name, 1);
11944 template_args = tsubst_template_args (template_args, args,
11945 complain, in_decl);
11946 name = TREE_OPERAND (name, 0);
11950 is_template = false;
11951 template_args = NULL_TREE;
11954 /* Substitute into the qualifying scope. When there are no ARGS, we
11955 are just trying to simplify a non-dependent expression. In that
11956 case the qualifying scope may be dependent, and, in any case,
11957 substituting will not help. */
11958 scope = TREE_OPERAND (qualified_id, 0);
11961 scope = tsubst (scope, args, complain, in_decl);
11962 expr = tsubst_copy (name, args, complain, in_decl);
11967 if (dependent_scope_p (scope))
11970 expr = build_min_nt (TEMPLATE_ID_EXPR, expr, template_args);
11971 return build_qualified_name (NULL_TREE, scope, expr,
11972 QUALIFIED_NAME_IS_TEMPLATE (qualified_id));
11975 if (!BASELINK_P (name) && !DECL_P (expr))
11977 if (TREE_CODE (expr) == BIT_NOT_EXPR)
11979 /* A BIT_NOT_EXPR is used to represent a destructor. */
11980 if (!check_dtor_name (scope, TREE_OPERAND (expr, 0)))
11982 error ("qualifying type %qT does not match destructor name ~%qT",
11983 scope, TREE_OPERAND (expr, 0));
11984 expr = error_mark_node;
11987 expr = lookup_qualified_name (scope, complete_dtor_identifier,
11988 /*is_type_p=*/0, false);
11991 expr = lookup_qualified_name (scope, expr, /*is_type_p=*/0, false);
11992 if (TREE_CODE (TREE_CODE (expr) == TEMPLATE_DECL
11993 ? DECL_TEMPLATE_RESULT (expr) : expr) == TYPE_DECL)
11995 if (complain & tf_error)
11997 error ("dependent-name %qE is parsed as a non-type, but "
11998 "instantiation yields a type", qualified_id);
11999 inform (input_location, "say %<typename %E%> if a type is meant", qualified_id);
12001 return error_mark_node;
12007 check_accessibility_of_qualified_id (expr, /*object_type=*/NULL_TREE,
12009 /* Remember that there was a reference to this entity. */
12013 if (expr == error_mark_node || TREE_CODE (expr) == TREE_LIST)
12015 if (complain & tf_error)
12016 qualified_name_lookup_error (scope,
12017 TREE_OPERAND (qualified_id, 1),
12018 expr, input_location);
12019 return error_mark_node;
12023 expr = lookup_template_function (expr, template_args);
12025 if (expr == error_mark_node && complain & tf_error)
12026 qualified_name_lookup_error (scope, TREE_OPERAND (qualified_id, 1),
12027 expr, input_location);
12028 else if (TYPE_P (scope))
12030 expr = (adjust_result_of_qualified_name_lookup
12031 (expr, scope, current_class_type));
12032 expr = (finish_qualified_id_expr
12033 (scope, expr, done, address_p && PTRMEM_OK_P (qualified_id),
12034 QUALIFIED_NAME_IS_TEMPLATE (qualified_id),
12035 /*template_arg_p=*/false));
12038 /* Expressions do not generally have reference type. */
12039 if (TREE_CODE (expr) != SCOPE_REF
12040 /* However, if we're about to form a pointer-to-member, we just
12041 want the referenced member referenced. */
12042 && TREE_CODE (expr) != OFFSET_REF)
12043 expr = convert_from_reference (expr);
12048 /* Like tsubst, but deals with expressions. This function just replaces
12049 template parms; to finish processing the resultant expression, use
12050 tsubst_copy_and_build or tsubst_expr. */
12053 tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl)
12055 enum tree_code code;
12058 if (t == NULL_TREE || t == error_mark_node || args == NULL_TREE)
12061 code = TREE_CODE (t);
12066 r = retrieve_local_specialization (t);
12072 /* We get here for a use of 'this' in an NSDMI. */
12073 if (DECL_NAME (t) == this_identifier
12074 && at_function_scope_p ()
12075 && DECL_CONSTRUCTOR_P (current_function_decl))
12076 return current_class_ptr;
12078 /* This can happen for a parameter name used later in a function
12079 declaration (such as in a late-specified return type). Just
12080 make a dummy decl, since it's only used for its type. */
12081 gcc_assert (cp_unevaluated_operand != 0);
12082 /* We copy T because want to tsubst the PARM_DECL only,
12083 not the following PARM_DECLs that are chained to T. */
12085 r = tsubst_decl (c, args, complain);
12086 /* Give it the template pattern as its context; its true context
12087 hasn't been instantiated yet and this is good enough for
12089 DECL_CONTEXT (r) = DECL_CONTEXT (t);
12092 if (TREE_CODE (r) == ARGUMENT_PACK_SELECT)
12093 r = ARGUMENT_PACK_SELECT_ARG (r);
12102 if (DECL_TEMPLATE_PARM_P (t))
12103 return tsubst_copy (DECL_INITIAL (t), args, complain, in_decl);
12104 /* There is no need to substitute into namespace-scope
12106 if (DECL_NAMESPACE_SCOPE_P (t))
12108 /* If ARGS is NULL, then T is known to be non-dependent. */
12109 if (args == NULL_TREE)
12110 return integral_constant_value (t);
12112 /* Unfortunately, we cannot just call lookup_name here.
12115 template <int I> int f() {
12117 struct S { void g() { E e = a; } };
12120 When we instantiate f<7>::S::g(), say, lookup_name is not
12121 clever enough to find f<7>::a. */
12123 = tsubst_aggr_type (TREE_TYPE (t), args, complain, in_decl,
12124 /*entering_scope=*/0);
12126 for (v = TYPE_VALUES (enum_type);
12128 v = TREE_CHAIN (v))
12129 if (TREE_PURPOSE (v) == DECL_NAME (t))
12130 return TREE_VALUE (v);
12132 /* We didn't find the name. That should never happen; if
12133 name-lookup found it during preliminary parsing, we
12134 should find it again here during instantiation. */
12135 gcc_unreachable ();
12140 if (DECL_CONTEXT (t))
12144 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args, complain, in_decl,
12145 /*entering_scope=*/1);
12146 if (ctx != DECL_CONTEXT (t))
12148 tree r = lookup_field (ctx, DECL_NAME (t), 0, false);
12151 if (complain & tf_error)
12152 error ("using invalid field %qD", t);
12153 return error_mark_node;
12162 case FUNCTION_DECL:
12163 if ((DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t))
12164 || local_variable_p (t))
12165 t = tsubst (t, args, complain, in_decl);
12169 case NAMESPACE_DECL:
12173 /* An OVERLOAD will always be a non-dependent overload set; an
12174 overload set from function scope will just be represented with an
12175 IDENTIFIER_NODE, and from class scope with a BASELINK. */
12176 gcc_assert (!uses_template_parms (t));
12180 return tsubst_baselink (t, current_class_type, args, complain, in_decl);
12182 case TEMPLATE_DECL:
12183 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
12184 return tsubst (TREE_TYPE (DECL_TEMPLATE_RESULT (t)),
12185 args, complain, in_decl);
12186 else if (DECL_FUNCTION_TEMPLATE_P (t) && DECL_MEMBER_TEMPLATE_P (t))
12187 return tsubst (t, args, complain, in_decl);
12188 else if (DECL_CLASS_SCOPE_P (t)
12189 && uses_template_parms (DECL_CONTEXT (t)))
12191 /* Template template argument like the following example need
12194 template <template <class> class TT> struct C {};
12195 template <class T> struct D {
12196 template <class U> struct E {};
12201 We are processing the template argument `E' in #1 for
12202 the template instantiation #2. Originally, `E' is a
12203 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
12204 have to substitute this with one having context `D<int>'. */
12206 tree context = tsubst (DECL_CONTEXT (t), args, complain, in_decl);
12207 return lookup_field (context, DECL_NAME(t), 0, false);
12210 /* Ordinary template template argument. */
12214 case REINTERPRET_CAST_EXPR:
12215 case CONST_CAST_EXPR:
12216 case STATIC_CAST_EXPR:
12217 case DYNAMIC_CAST_EXPR:
12218 case IMPLICIT_CONV_EXPR:
12222 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
12223 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
12226 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
12232 ++cp_unevaluated_operand;
12233 ++c_inhibit_evaluation_warnings;
12234 /* We only want to compute the number of arguments. */
12235 expanded = tsubst_pack_expansion (TREE_OPERAND (t, 0), args,
12236 complain, in_decl);
12237 --cp_unevaluated_operand;
12238 --c_inhibit_evaluation_warnings;
12240 if (TREE_CODE (expanded) == TREE_VEC)
12241 len = TREE_VEC_LENGTH (expanded);
12243 if (expanded == error_mark_node)
12244 return error_mark_node;
12245 else if (PACK_EXPANSION_P (expanded)
12246 || (TREE_CODE (expanded) == TREE_VEC
12248 && PACK_EXPANSION_P (TREE_VEC_ELT (expanded, len-1))))
12250 if (TREE_CODE (expanded) == TREE_VEC)
12251 expanded = TREE_VEC_ELT (expanded, len - 1);
12253 if (TYPE_P (expanded))
12254 return cxx_sizeof_or_alignof_type (expanded, SIZEOF_EXPR,
12255 complain & tf_error);
12257 return cxx_sizeof_or_alignof_expr (expanded, SIZEOF_EXPR,
12258 complain & tf_error);
12261 return build_int_cst (size_type_node, len);
12267 case TRUTH_NOT_EXPR:
12270 case UNARY_PLUS_EXPR: /* Unary + */
12272 case AT_ENCODE_EXPR:
12276 case REALPART_EXPR:
12277 case IMAGPART_EXPR:
12279 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
12280 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
12282 case COMPONENT_REF:
12287 object = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
12288 name = TREE_OPERAND (t, 1);
12289 if (TREE_CODE (name) == BIT_NOT_EXPR)
12291 name = tsubst_copy (TREE_OPERAND (name, 0), args,
12292 complain, in_decl);
12293 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
12295 else if (TREE_CODE (name) == SCOPE_REF
12296 && TREE_CODE (TREE_OPERAND (name, 1)) == BIT_NOT_EXPR)
12298 tree base = tsubst_copy (TREE_OPERAND (name, 0), args,
12299 complain, in_decl);
12300 name = TREE_OPERAND (name, 1);
12301 name = tsubst_copy (TREE_OPERAND (name, 0), args,
12302 complain, in_decl);
12303 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
12304 name = build_qualified_name (/*type=*/NULL_TREE,
12306 /*template_p=*/false);
12308 else if (BASELINK_P (name))
12309 name = tsubst_baselink (name,
12310 non_reference (TREE_TYPE (object)),
12314 name = tsubst_copy (name, args, complain, in_decl);
12315 return build_nt (COMPONENT_REF, object, name, NULL_TREE);
12321 case TRUNC_DIV_EXPR:
12322 case CEIL_DIV_EXPR:
12323 case FLOOR_DIV_EXPR:
12324 case ROUND_DIV_EXPR:
12325 case EXACT_DIV_EXPR:
12329 case TRUNC_MOD_EXPR:
12330 case FLOOR_MOD_EXPR:
12331 case TRUTH_ANDIF_EXPR:
12332 case TRUTH_ORIF_EXPR:
12333 case TRUTH_AND_EXPR:
12334 case TRUTH_OR_EXPR:
12347 case COMPOUND_EXPR:
12350 case PREDECREMENT_EXPR:
12351 case PREINCREMENT_EXPR:
12352 case POSTDECREMENT_EXPR:
12353 case POSTINCREMENT_EXPR:
12355 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12356 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
12359 return build_qualified_name (/*type=*/NULL_TREE,
12360 tsubst_copy (TREE_OPERAND (t, 0),
12361 args, complain, in_decl),
12362 tsubst_copy (TREE_OPERAND (t, 1),
12363 args, complain, in_decl),
12364 QUALIFIED_NAME_IS_TEMPLATE (t));
12369 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12370 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
12371 NULL_TREE, NULL_TREE);
12375 int n = VL_EXP_OPERAND_LENGTH (t);
12376 tree result = build_vl_exp (CALL_EXPR, n);
12378 for (i = 0; i < n; i++)
12379 TREE_OPERAND (t, i) = tsubst_copy (TREE_OPERAND (t, i), args,
12380 complain, in_decl);
12386 case PSEUDO_DTOR_EXPR:
12389 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12390 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
12391 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
12392 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
12399 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12400 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
12401 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
12402 NEW_EXPR_USE_GLOBAL (r) = NEW_EXPR_USE_GLOBAL (t);
12409 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12410 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
12411 DELETE_EXPR_USE_GLOBAL (r) = DELETE_EXPR_USE_GLOBAL (t);
12412 DELETE_EXPR_USE_VEC (r) = DELETE_EXPR_USE_VEC (t);
12416 case TEMPLATE_ID_EXPR:
12418 /* Substituted template arguments */
12419 tree fn = TREE_OPERAND (t, 0);
12420 tree targs = TREE_OPERAND (t, 1);
12422 fn = tsubst_copy (fn, args, complain, in_decl);
12424 targs = tsubst_template_args (targs, args, complain, in_decl);
12426 return lookup_template_function (fn, targs);
12431 tree purpose, value, chain;
12433 if (t == void_list_node)
12436 purpose = TREE_PURPOSE (t);
12438 purpose = tsubst_copy (purpose, args, complain, in_decl);
12439 value = TREE_VALUE (t);
12441 value = tsubst_copy (value, args, complain, in_decl);
12442 chain = TREE_CHAIN (t);
12443 if (chain && chain != void_type_node)
12444 chain = tsubst_copy (chain, args, complain, in_decl);
12445 if (purpose == TREE_PURPOSE (t)
12446 && value == TREE_VALUE (t)
12447 && chain == TREE_CHAIN (t))
12449 return tree_cons (purpose, value, chain);
12454 case ENUMERAL_TYPE:
12456 case TEMPLATE_TYPE_PARM:
12457 case TEMPLATE_TEMPLATE_PARM:
12458 case BOUND_TEMPLATE_TEMPLATE_PARM:
12459 case TEMPLATE_PARM_INDEX:
12461 case REFERENCE_TYPE:
12463 case FUNCTION_TYPE:
12466 case TYPENAME_TYPE:
12467 case UNBOUND_CLASS_TEMPLATE:
12469 case DECLTYPE_TYPE:
12471 return tsubst (t, args, complain, in_decl);
12473 case IDENTIFIER_NODE:
12474 if (IDENTIFIER_TYPENAME_P (t))
12476 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12477 return mangle_conv_op_name_for_type (new_type);
12483 /* This is handled by tsubst_copy_and_build. */
12484 gcc_unreachable ();
12487 return build_x_va_arg (tsubst_copy (TREE_OPERAND (t, 0), args, complain,
12489 tsubst (TREE_TYPE (t), args, complain, in_decl));
12491 case CLEANUP_POINT_EXPR:
12492 /* We shouldn't have built any of these during initial template
12493 generation. Instead, they should be built during instantiation
12494 in response to the saved STMT_IS_FULL_EXPR_P setting. */
12495 gcc_unreachable ();
12499 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
12500 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12501 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
12502 PTRMEM_OK_P (r) = PTRMEM_OK_P (t);
12503 mark_used (TREE_OPERAND (r, 1));
12506 case EXPR_PACK_EXPANSION:
12507 error ("invalid use of pack expansion expression");
12508 return error_mark_node;
12510 case NONTYPE_ARGUMENT_PACK:
12511 error ("use %<...%> to expand argument pack");
12512 return error_mark_node;
12519 /* Instantiate any typedefs in the type. */
12520 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12521 r = fold_convert (type, t);
12522 gcc_assert (TREE_CODE (r) == code);
12527 /* These can sometimes show up in a partial instantiation, but never
12528 involve template parms. */
12529 gcc_assert (!uses_template_parms (t));
12533 /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */
12534 gcc_checking_assert (false);
12539 /* Like tsubst_copy, but specifically for OpenMP clauses. */
12542 tsubst_omp_clauses (tree clauses, tree args, tsubst_flags_t complain,
12545 tree new_clauses = NULL, nc, oc;
12547 for (oc = clauses; oc ; oc = OMP_CLAUSE_CHAIN (oc))
12549 nc = copy_node (oc);
12550 OMP_CLAUSE_CHAIN (nc) = new_clauses;
12553 switch (OMP_CLAUSE_CODE (nc))
12555 case OMP_CLAUSE_LASTPRIVATE:
12556 if (OMP_CLAUSE_LASTPRIVATE_STMT (oc))
12558 OMP_CLAUSE_LASTPRIVATE_STMT (nc) = push_stmt_list ();
12559 tsubst_expr (OMP_CLAUSE_LASTPRIVATE_STMT (oc), args, complain,
12560 in_decl, /*integral_constant_expression_p=*/false);
12561 OMP_CLAUSE_LASTPRIVATE_STMT (nc)
12562 = pop_stmt_list (OMP_CLAUSE_LASTPRIVATE_STMT (nc));
12565 case OMP_CLAUSE_PRIVATE:
12566 case OMP_CLAUSE_SHARED:
12567 case OMP_CLAUSE_FIRSTPRIVATE:
12568 case OMP_CLAUSE_REDUCTION:
12569 case OMP_CLAUSE_COPYIN:
12570 case OMP_CLAUSE_COPYPRIVATE:
12571 case OMP_CLAUSE_IF:
12572 case OMP_CLAUSE_NUM_THREADS:
12573 case OMP_CLAUSE_SCHEDULE:
12574 case OMP_CLAUSE_COLLAPSE:
12575 case OMP_CLAUSE_FINAL:
12576 OMP_CLAUSE_OPERAND (nc, 0)
12577 = tsubst_expr (OMP_CLAUSE_OPERAND (oc, 0), args, complain,
12578 in_decl, /*integral_constant_expression_p=*/false);
12580 case OMP_CLAUSE_NOWAIT:
12581 case OMP_CLAUSE_ORDERED:
12582 case OMP_CLAUSE_DEFAULT:
12583 case OMP_CLAUSE_UNTIED:
12584 case OMP_CLAUSE_MERGEABLE:
12587 gcc_unreachable ();
12591 return finish_omp_clauses (nreverse (new_clauses));
12594 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
12597 tsubst_copy_asm_operands (tree t, tree args, tsubst_flags_t complain,
12600 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
12602 tree purpose, value, chain;
12607 if (TREE_CODE (t) != TREE_LIST)
12608 return tsubst_copy_and_build (t, args, complain, in_decl,
12609 /*function_p=*/false,
12610 /*integral_constant_expression_p=*/false);
12612 if (t == void_list_node)
12615 purpose = TREE_PURPOSE (t);
12617 purpose = RECUR (purpose);
12618 value = TREE_VALUE (t);
12621 if (TREE_CODE (value) != LABEL_DECL)
12622 value = RECUR (value);
12625 value = lookup_label (DECL_NAME (value));
12626 gcc_assert (TREE_CODE (value) == LABEL_DECL);
12627 TREE_USED (value) = 1;
12630 chain = TREE_CHAIN (t);
12631 if (chain && chain != void_type_node)
12632 chain = RECUR (chain);
12633 return tree_cons (purpose, value, chain);
12637 /* Substitute one OMP_FOR iterator. */
12640 tsubst_omp_for_iterator (tree t, int i, tree declv, tree initv,
12641 tree condv, tree incrv, tree *clauses,
12642 tree args, tsubst_flags_t complain, tree in_decl,
12643 bool integral_constant_expression_p)
12645 #define RECUR(NODE) \
12646 tsubst_expr ((NODE), args, complain, in_decl, \
12647 integral_constant_expression_p)
12648 tree decl, init, cond, incr, auto_node;
12650 init = TREE_VEC_ELT (OMP_FOR_INIT (t), i);
12651 gcc_assert (TREE_CODE (init) == MODIFY_EXPR);
12652 decl = RECUR (TREE_OPERAND (init, 0));
12653 init = TREE_OPERAND (init, 1);
12654 auto_node = type_uses_auto (TREE_TYPE (decl));
12655 if (auto_node && init)
12657 tree init_expr = init;
12658 if (TREE_CODE (init_expr) == DECL_EXPR)
12659 init_expr = DECL_INITIAL (DECL_EXPR_DECL (init_expr));
12660 init_expr = RECUR (init_expr);
12662 = do_auto_deduction (TREE_TYPE (decl), init_expr, auto_node);
12664 gcc_assert (!type_dependent_expression_p (decl));
12666 if (!CLASS_TYPE_P (TREE_TYPE (decl)))
12668 cond = RECUR (TREE_VEC_ELT (OMP_FOR_COND (t), i));
12669 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
12670 if (TREE_CODE (incr) == MODIFY_EXPR)
12671 incr = build_x_modify_expr (RECUR (TREE_OPERAND (incr, 0)), NOP_EXPR,
12672 RECUR (TREE_OPERAND (incr, 1)),
12675 incr = RECUR (incr);
12676 TREE_VEC_ELT (declv, i) = decl;
12677 TREE_VEC_ELT (initv, i) = init;
12678 TREE_VEC_ELT (condv, i) = cond;
12679 TREE_VEC_ELT (incrv, i) = incr;
12683 if (init && TREE_CODE (init) != DECL_EXPR)
12686 for (c = *clauses; c ; c = OMP_CLAUSE_CHAIN (c))
12688 if ((OMP_CLAUSE_CODE (c) == OMP_CLAUSE_PRIVATE
12689 || OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LASTPRIVATE)
12690 && OMP_CLAUSE_DECL (c) == decl)
12692 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_FIRSTPRIVATE
12693 && OMP_CLAUSE_DECL (c) == decl)
12694 error ("iteration variable %qD should not be firstprivate", decl);
12695 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_REDUCTION
12696 && OMP_CLAUSE_DECL (c) == decl)
12697 error ("iteration variable %qD should not be reduction", decl);
12701 c = build_omp_clause (input_location, OMP_CLAUSE_PRIVATE);
12702 OMP_CLAUSE_DECL (c) = decl;
12703 c = finish_omp_clauses (c);
12706 OMP_CLAUSE_CHAIN (c) = *clauses;
12711 cond = TREE_VEC_ELT (OMP_FOR_COND (t), i);
12712 if (COMPARISON_CLASS_P (cond))
12713 cond = build2 (TREE_CODE (cond), boolean_type_node,
12714 RECUR (TREE_OPERAND (cond, 0)),
12715 RECUR (TREE_OPERAND (cond, 1)));
12717 cond = RECUR (cond);
12718 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
12719 switch (TREE_CODE (incr))
12721 case PREINCREMENT_EXPR:
12722 case PREDECREMENT_EXPR:
12723 case POSTINCREMENT_EXPR:
12724 case POSTDECREMENT_EXPR:
12725 incr = build2 (TREE_CODE (incr), TREE_TYPE (decl),
12726 RECUR (TREE_OPERAND (incr, 0)), NULL_TREE);
12729 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
12730 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
12732 tree rhs = TREE_OPERAND (incr, 1);
12733 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
12734 RECUR (TREE_OPERAND (incr, 0)),
12735 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
12736 RECUR (TREE_OPERAND (rhs, 0)),
12737 RECUR (TREE_OPERAND (rhs, 1))));
12740 incr = RECUR (incr);
12743 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
12744 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
12746 tree lhs = RECUR (TREE_OPERAND (incr, 0));
12747 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl), lhs,
12748 build2 (TREE_CODE (TREE_OPERAND (incr, 1)),
12749 TREE_TYPE (decl), lhs,
12750 RECUR (TREE_OPERAND (incr, 2))));
12752 else if (TREE_CODE (TREE_OPERAND (incr, 1)) == NOP_EXPR
12753 && (TREE_CODE (TREE_OPERAND (incr, 2)) == PLUS_EXPR
12754 || (TREE_CODE (TREE_OPERAND (incr, 2)) == MINUS_EXPR)))
12756 tree rhs = TREE_OPERAND (incr, 2);
12757 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
12758 RECUR (TREE_OPERAND (incr, 0)),
12759 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
12760 RECUR (TREE_OPERAND (rhs, 0)),
12761 RECUR (TREE_OPERAND (rhs, 1))));
12764 incr = RECUR (incr);
12767 incr = RECUR (incr);
12771 TREE_VEC_ELT (declv, i) = decl;
12772 TREE_VEC_ELT (initv, i) = init;
12773 TREE_VEC_ELT (condv, i) = cond;
12774 TREE_VEC_ELT (incrv, i) = incr;
12778 /* Like tsubst_copy for expressions, etc. but also does semantic
12782 tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl,
12783 bool integral_constant_expression_p)
12785 #define RECUR(NODE) \
12786 tsubst_expr ((NODE), args, complain, in_decl, \
12787 integral_constant_expression_p)
12791 if (t == NULL_TREE || t == error_mark_node)
12794 if (EXPR_HAS_LOCATION (t))
12795 input_location = EXPR_LOCATION (t);
12796 if (STATEMENT_CODE_P (TREE_CODE (t)))
12797 current_stmt_tree ()->stmts_are_full_exprs_p = STMT_IS_FULL_EXPR_P (t);
12799 switch (TREE_CODE (t))
12801 case STATEMENT_LIST:
12803 tree_stmt_iterator i;
12804 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
12805 RECUR (tsi_stmt (i));
12809 case CTOR_INITIALIZER:
12810 finish_mem_initializers (tsubst_initializer_list
12811 (TREE_OPERAND (t, 0), args));
12815 finish_return_stmt (RECUR (TREE_OPERAND (t, 0)));
12819 tmp = RECUR (EXPR_STMT_EXPR (t));
12820 if (EXPR_STMT_STMT_EXPR_RESULT (t))
12821 finish_stmt_expr_expr (tmp, cur_stmt_expr);
12823 finish_expr_stmt (tmp);
12827 do_using_directive (USING_STMT_NAMESPACE (t));
12832 tree decl, pattern_decl;
12835 pattern_decl = decl = DECL_EXPR_DECL (t);
12836 if (TREE_CODE (decl) == LABEL_DECL)
12837 finish_label_decl (DECL_NAME (decl));
12838 else if (TREE_CODE (decl) == USING_DECL)
12840 tree scope = USING_DECL_SCOPE (decl);
12841 tree name = DECL_NAME (decl);
12844 scope = tsubst (scope, args, complain, in_decl);
12845 decl = lookup_qualified_name (scope, name,
12846 /*is_type_p=*/false,
12847 /*complain=*/false);
12848 if (decl == error_mark_node || TREE_CODE (decl) == TREE_LIST)
12849 qualified_name_lookup_error (scope, name, decl, input_location);
12851 do_local_using_decl (decl, scope, name);
12855 init = DECL_INITIAL (decl);
12856 decl = tsubst (decl, args, complain, in_decl);
12857 if (decl != error_mark_node)
12859 /* By marking the declaration as instantiated, we avoid
12860 trying to instantiate it. Since instantiate_decl can't
12861 handle local variables, and since we've already done
12862 all that needs to be done, that's the right thing to
12864 if (TREE_CODE (decl) == VAR_DECL)
12865 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
12866 if (TREE_CODE (decl) == VAR_DECL
12867 && ANON_AGGR_TYPE_P (TREE_TYPE (decl)))
12868 /* Anonymous aggregates are a special case. */
12869 finish_anon_union (decl);
12870 else if (is_capture_proxy (DECL_EXPR_DECL (t)))
12872 DECL_CONTEXT (decl) = current_function_decl;
12873 insert_capture_proxy (decl);
12877 int const_init = false;
12878 maybe_push_decl (decl);
12879 if (TREE_CODE (decl) == VAR_DECL
12880 && DECL_PRETTY_FUNCTION_P (decl))
12882 /* For __PRETTY_FUNCTION__ we have to adjust the
12884 const char *const name
12885 = cxx_printable_name (current_function_decl, 2);
12886 init = cp_fname_init (name, &TREE_TYPE (decl));
12890 tree t = RECUR (init);
12894 /* If we had an initializer but it
12895 instantiated to nothing,
12896 value-initialize the object. This will
12897 only occur when the initializer was a
12898 pack expansion where the parameter packs
12899 used in that expansion were of length
12901 init = build_value_init (TREE_TYPE (decl),
12903 if (TREE_CODE (init) == AGGR_INIT_EXPR)
12904 init = get_target_expr_sfinae (init, complain);
12910 if (TREE_CODE (decl) == VAR_DECL)
12911 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
12913 cp_finish_decl (decl, init, const_init, NULL_TREE, 0);
12918 /* A DECL_EXPR can also be used as an expression, in the condition
12919 clause of an if/for/while construct. */
12924 stmt = begin_for_stmt (NULL_TREE, NULL_TREE);
12925 RECUR (FOR_INIT_STMT (t));
12926 finish_for_init_stmt (stmt);
12927 tmp = RECUR (FOR_COND (t));
12928 finish_for_cond (tmp, stmt);
12929 tmp = RECUR (FOR_EXPR (t));
12930 finish_for_expr (tmp, stmt);
12931 RECUR (FOR_BODY (t));
12932 finish_for_stmt (stmt);
12935 case RANGE_FOR_STMT:
12938 stmt = begin_for_stmt (NULL_TREE, NULL_TREE);
12939 decl = RANGE_FOR_DECL (t);
12940 decl = tsubst (decl, args, complain, in_decl);
12941 maybe_push_decl (decl);
12942 expr = RECUR (RANGE_FOR_EXPR (t));
12943 stmt = cp_convert_range_for (stmt, decl, expr);
12944 RECUR (RANGE_FOR_BODY (t));
12945 finish_for_stmt (stmt);
12950 stmt = begin_while_stmt ();
12951 tmp = RECUR (WHILE_COND (t));
12952 finish_while_stmt_cond (tmp, stmt);
12953 RECUR (WHILE_BODY (t));
12954 finish_while_stmt (stmt);
12958 stmt = begin_do_stmt ();
12959 RECUR (DO_BODY (t));
12960 finish_do_body (stmt);
12961 tmp = RECUR (DO_COND (t));
12962 finish_do_stmt (tmp, stmt);
12966 stmt = begin_if_stmt ();
12967 tmp = RECUR (IF_COND (t));
12968 finish_if_stmt_cond (tmp, stmt);
12969 RECUR (THEN_CLAUSE (t));
12970 finish_then_clause (stmt);
12972 if (ELSE_CLAUSE (t))
12974 begin_else_clause (stmt);
12975 RECUR (ELSE_CLAUSE (t));
12976 finish_else_clause (stmt);
12979 finish_if_stmt (stmt);
12983 if (BIND_EXPR_BODY_BLOCK (t))
12984 stmt = begin_function_body ();
12986 stmt = begin_compound_stmt (BIND_EXPR_TRY_BLOCK (t)
12987 ? BCS_TRY_BLOCK : 0);
12989 RECUR (BIND_EXPR_BODY (t));
12991 if (BIND_EXPR_BODY_BLOCK (t))
12992 finish_function_body (stmt);
12994 finish_compound_stmt (stmt);
12998 finish_break_stmt ();
13001 case CONTINUE_STMT:
13002 finish_continue_stmt ();
13006 stmt = begin_switch_stmt ();
13007 tmp = RECUR (SWITCH_STMT_COND (t));
13008 finish_switch_cond (tmp, stmt);
13009 RECUR (SWITCH_STMT_BODY (t));
13010 finish_switch_stmt (stmt);
13013 case CASE_LABEL_EXPR:
13014 finish_case_label (EXPR_LOCATION (t),
13015 RECUR (CASE_LOW (t)),
13016 RECUR (CASE_HIGH (t)));
13021 tree decl = LABEL_EXPR_LABEL (t);
13024 label = finish_label_stmt (DECL_NAME (decl));
13025 if (DECL_ATTRIBUTES (decl) != NULL_TREE)
13026 cplus_decl_attributes (&label, DECL_ATTRIBUTES (decl), 0);
13031 tmp = GOTO_DESTINATION (t);
13032 if (TREE_CODE (tmp) != LABEL_DECL)
13033 /* Computed goto's must be tsubst'd into. On the other hand,
13034 non-computed gotos must not be; the identifier in question
13035 will have no binding. */
13038 tmp = DECL_NAME (tmp);
13039 finish_goto_stmt (tmp);
13043 tmp = finish_asm_stmt
13044 (ASM_VOLATILE_P (t),
13045 RECUR (ASM_STRING (t)),
13046 tsubst_copy_asm_operands (ASM_OUTPUTS (t), args, complain, in_decl),
13047 tsubst_copy_asm_operands (ASM_INPUTS (t), args, complain, in_decl),
13048 tsubst_copy_asm_operands (ASM_CLOBBERS (t), args, complain, in_decl),
13049 tsubst_copy_asm_operands (ASM_LABELS (t), args, complain, in_decl));
13051 tree asm_expr = tmp;
13052 if (TREE_CODE (asm_expr) == CLEANUP_POINT_EXPR)
13053 asm_expr = TREE_OPERAND (asm_expr, 0);
13054 ASM_INPUT_P (asm_expr) = ASM_INPUT_P (t);
13061 stmt = begin_try_block ();
13062 RECUR (TRY_STMTS (t));
13063 finish_cleanup_try_block (stmt);
13064 finish_cleanup (RECUR (TRY_HANDLERS (t)), stmt);
13068 tree compound_stmt = NULL_TREE;
13070 if (FN_TRY_BLOCK_P (t))
13071 stmt = begin_function_try_block (&compound_stmt);
13073 stmt = begin_try_block ();
13075 RECUR (TRY_STMTS (t));
13077 if (FN_TRY_BLOCK_P (t))
13078 finish_function_try_block (stmt);
13080 finish_try_block (stmt);
13082 RECUR (TRY_HANDLERS (t));
13083 if (FN_TRY_BLOCK_P (t))
13084 finish_function_handler_sequence (stmt, compound_stmt);
13086 finish_handler_sequence (stmt);
13092 tree decl = HANDLER_PARMS (t);
13096 decl = tsubst (decl, args, complain, in_decl);
13097 /* Prevent instantiate_decl from trying to instantiate
13098 this variable. We've already done all that needs to be
13100 if (decl != error_mark_node)
13101 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
13103 stmt = begin_handler ();
13104 finish_handler_parms (decl, stmt);
13105 RECUR (HANDLER_BODY (t));
13106 finish_handler (stmt);
13111 tsubst (TREE_TYPE (t), args, complain, NULL_TREE);
13114 case STATIC_ASSERT:
13117 tsubst_expr (STATIC_ASSERT_CONDITION (t),
13120 /*integral_constant_expression_p=*/true);
13121 finish_static_assert (condition,
13122 STATIC_ASSERT_MESSAGE (t),
13123 STATIC_ASSERT_SOURCE_LOCATION (t),
13124 /*member_p=*/false);
13129 tmp = tsubst_omp_clauses (OMP_PARALLEL_CLAUSES (t),
13130 args, complain, in_decl);
13131 stmt = begin_omp_parallel ();
13132 RECUR (OMP_PARALLEL_BODY (t));
13133 OMP_PARALLEL_COMBINED (finish_omp_parallel (tmp, stmt))
13134 = OMP_PARALLEL_COMBINED (t);
13138 tmp = tsubst_omp_clauses (OMP_TASK_CLAUSES (t),
13139 args, complain, in_decl);
13140 stmt = begin_omp_task ();
13141 RECUR (OMP_TASK_BODY (t));
13142 finish_omp_task (tmp, stmt);
13147 tree clauses, body, pre_body;
13148 tree declv, initv, condv, incrv;
13151 clauses = tsubst_omp_clauses (OMP_FOR_CLAUSES (t),
13152 args, complain, in_decl);
13153 declv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
13154 initv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
13155 condv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
13156 incrv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
13158 for (i = 0; i < TREE_VEC_LENGTH (OMP_FOR_INIT (t)); i++)
13159 tsubst_omp_for_iterator (t, i, declv, initv, condv, incrv,
13160 &clauses, args, complain, in_decl,
13161 integral_constant_expression_p);
13163 stmt = begin_omp_structured_block ();
13165 for (i = 0; i < TREE_VEC_LENGTH (initv); i++)
13166 if (TREE_VEC_ELT (initv, i) == NULL
13167 || TREE_CODE (TREE_VEC_ELT (initv, i)) != DECL_EXPR)
13168 TREE_VEC_ELT (initv, i) = RECUR (TREE_VEC_ELT (initv, i));
13169 else if (CLASS_TYPE_P (TREE_TYPE (TREE_VEC_ELT (initv, i))))
13171 tree init = RECUR (TREE_VEC_ELT (initv, i));
13172 gcc_assert (init == TREE_VEC_ELT (declv, i));
13173 TREE_VEC_ELT (initv, i) = NULL_TREE;
13177 tree decl_expr = TREE_VEC_ELT (initv, i);
13178 tree init = DECL_INITIAL (DECL_EXPR_DECL (decl_expr));
13179 gcc_assert (init != NULL);
13180 TREE_VEC_ELT (initv, i) = RECUR (init);
13181 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = NULL;
13183 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = init;
13186 pre_body = push_stmt_list ();
13187 RECUR (OMP_FOR_PRE_BODY (t));
13188 pre_body = pop_stmt_list (pre_body);
13190 body = push_stmt_list ();
13191 RECUR (OMP_FOR_BODY (t));
13192 body = pop_stmt_list (body);
13194 t = finish_omp_for (EXPR_LOCATION (t), declv, initv, condv, incrv,
13195 body, pre_body, clauses);
13197 add_stmt (finish_omp_structured_block (stmt));
13203 tmp = tsubst_omp_clauses (OMP_CLAUSES (t), args, complain, in_decl);
13204 stmt = push_stmt_list ();
13205 RECUR (OMP_BODY (t));
13206 stmt = pop_stmt_list (stmt);
13209 OMP_BODY (t) = stmt;
13210 OMP_CLAUSES (t) = tmp;
13218 stmt = push_stmt_list ();
13219 RECUR (OMP_BODY (t));
13220 stmt = pop_stmt_list (stmt);
13223 OMP_BODY (t) = stmt;
13228 gcc_assert (OMP_ATOMIC_DEPENDENT_P (t));
13229 if (TREE_CODE (TREE_OPERAND (t, 1)) != MODIFY_EXPR)
13231 tree op1 = TREE_OPERAND (t, 1);
13232 tree rhs1 = NULL_TREE;
13234 if (TREE_CODE (op1) == COMPOUND_EXPR)
13236 rhs1 = RECUR (TREE_OPERAND (op1, 0));
13237 op1 = TREE_OPERAND (op1, 1);
13239 lhs = RECUR (TREE_OPERAND (op1, 0));
13240 rhs = RECUR (TREE_OPERAND (op1, 1));
13241 finish_omp_atomic (OMP_ATOMIC, TREE_CODE (op1), lhs, rhs,
13242 NULL_TREE, NULL_TREE, rhs1);
13246 tree op1 = TREE_OPERAND (t, 1);
13247 tree v = NULL_TREE, lhs, rhs = NULL_TREE, lhs1 = NULL_TREE;
13248 tree rhs1 = NULL_TREE;
13249 enum tree_code code = TREE_CODE (TREE_OPERAND (op1, 1));
13250 enum tree_code opcode = NOP_EXPR;
13251 if (code == OMP_ATOMIC_READ)
13253 v = RECUR (TREE_OPERAND (op1, 0));
13254 lhs = RECUR (TREE_OPERAND (TREE_OPERAND (op1, 1), 0));
13256 else if (code == OMP_ATOMIC_CAPTURE_OLD
13257 || code == OMP_ATOMIC_CAPTURE_NEW)
13259 tree op11 = TREE_OPERAND (TREE_OPERAND (op1, 1), 1);
13260 v = RECUR (TREE_OPERAND (op1, 0));
13261 lhs1 = RECUR (TREE_OPERAND (TREE_OPERAND (op1, 1), 0));
13262 if (TREE_CODE (op11) == COMPOUND_EXPR)
13264 rhs1 = RECUR (TREE_OPERAND (op11, 0));
13265 op11 = TREE_OPERAND (op11, 1);
13267 lhs = RECUR (TREE_OPERAND (op11, 0));
13268 rhs = RECUR (TREE_OPERAND (op11, 1));
13269 opcode = TREE_CODE (op11);
13274 lhs = RECUR (TREE_OPERAND (op1, 0));
13275 rhs = RECUR (TREE_OPERAND (op1, 1));
13277 finish_omp_atomic (code, opcode, lhs, rhs, v, lhs1, rhs1);
13281 case TRANSACTION_EXPR:
13284 flags |= (TRANSACTION_EXPR_OUTER (t) ? TM_STMT_ATTR_OUTER : 0);
13285 flags |= (TRANSACTION_EXPR_RELAXED (t) ? TM_STMT_ATTR_RELAXED : 0);
13287 if (TRANSACTION_EXPR_IS_STMT (t))
13289 tree body = TRANSACTION_EXPR_BODY (t);
13290 tree noex = NULL_TREE;
13291 if (TREE_CODE (body) == MUST_NOT_THROW_EXPR)
13293 noex = MUST_NOT_THROW_COND (body);
13294 if (noex == NULL_TREE)
13295 noex = boolean_true_node;
13296 body = TREE_OPERAND (body, 0);
13298 stmt = begin_transaction_stmt (input_location, NULL, flags);
13300 finish_transaction_stmt (stmt, NULL, flags, RECUR (noex));
13304 stmt = build_transaction_expr (EXPR_LOCATION (t),
13305 RECUR (TRANSACTION_EXPR_BODY (t)),
13312 case MUST_NOT_THROW_EXPR:
13313 return build_must_not_throw_expr (RECUR (TREE_OPERAND (t, 0)),
13314 RECUR (MUST_NOT_THROW_COND (t)));
13316 case EXPR_PACK_EXPANSION:
13317 error ("invalid use of pack expansion expression");
13318 return error_mark_node;
13320 case NONTYPE_ARGUMENT_PACK:
13321 error ("use %<...%> to expand argument pack");
13322 return error_mark_node;
13325 gcc_assert (!STATEMENT_CODE_P (TREE_CODE (t)));
13327 return tsubst_copy_and_build (t, args, complain, in_decl,
13328 /*function_p=*/false,
13329 integral_constant_expression_p);
13336 /* T is a postfix-expression that is not being used in a function
13337 call. Return the substituted version of T. */
13340 tsubst_non_call_postfix_expression (tree t, tree args,
13341 tsubst_flags_t complain,
13344 if (TREE_CODE (t) == SCOPE_REF)
13345 t = tsubst_qualified_id (t, args, complain, in_decl,
13346 /*done=*/false, /*address_p=*/false);
13348 t = tsubst_copy_and_build (t, args, complain, in_decl,
13349 /*function_p=*/false,
13350 /*integral_constant_expression_p=*/false);
13355 /* Like tsubst but deals with expressions and performs semantic
13356 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
13359 tsubst_copy_and_build (tree t,
13361 tsubst_flags_t complain,
13364 bool integral_constant_expression_p)
13366 #define RECUR(NODE) \
13367 tsubst_copy_and_build (NODE, args, complain, in_decl, \
13368 /*function_p=*/false, \
13369 integral_constant_expression_p)
13373 if (t == NULL_TREE || t == error_mark_node)
13376 switch (TREE_CODE (t))
13380 /* Fall through. */
13381 case IDENTIFIER_NODE:
13385 bool non_integral_constant_expression_p;
13386 const char *error_msg;
13388 if (IDENTIFIER_TYPENAME_P (t))
13390 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
13391 t = mangle_conv_op_name_for_type (new_type);
13394 /* Look up the name. */
13395 decl = lookup_name (t);
13397 /* By convention, expressions use ERROR_MARK_NODE to indicate
13398 failure, not NULL_TREE. */
13399 if (decl == NULL_TREE)
13400 decl = error_mark_node;
13402 decl = finish_id_expression (t, decl, NULL_TREE,
13404 integral_constant_expression_p,
13405 /*allow_non_integral_constant_expression_p=*/(cxx_dialect >= cxx0x),
13406 &non_integral_constant_expression_p,
13407 /*template_p=*/false,
13409 /*address_p=*/false,
13410 /*template_arg_p=*/false,
13415 if (!function_p && TREE_CODE (decl) == IDENTIFIER_NODE)
13417 if (complain & tf_error)
13418 unqualified_name_lookup_error (decl);
13419 decl = error_mark_node;
13424 case TEMPLATE_ID_EXPR:
13427 tree templ = RECUR (TREE_OPERAND (t, 0));
13428 tree targs = TREE_OPERAND (t, 1);
13431 targs = tsubst_template_args (targs, args, complain, in_decl);
13433 if (TREE_CODE (templ) == COMPONENT_REF)
13435 object = TREE_OPERAND (templ, 0);
13436 templ = TREE_OPERAND (templ, 1);
13439 object = NULL_TREE;
13440 templ = lookup_template_function (templ, targs);
13443 return build3 (COMPONENT_REF, TREE_TYPE (templ),
13444 object, templ, NULL_TREE);
13446 return baselink_for_fns (templ);
13451 tree r = RECUR (TREE_OPERAND (t, 0));
13453 if (REFERENCE_REF_P (t))
13455 /* A type conversion to reference type will be enclosed in
13456 such an indirect ref, but the substitution of the cast
13457 will have also added such an indirect ref. */
13458 if (TREE_CODE (TREE_TYPE (r)) == REFERENCE_TYPE)
13459 r = convert_from_reference (r);
13462 r = build_x_indirect_ref (r, RO_UNARY_STAR, complain);
13468 (tsubst (TREE_TYPE (t), args, complain, in_decl),
13469 RECUR (TREE_OPERAND (t, 0)));
13471 case IMPLICIT_CONV_EXPR:
13473 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
13474 tree expr = RECUR (TREE_OPERAND (t, 0));
13475 int flags = LOOKUP_IMPLICIT;
13476 if (IMPLICIT_CONV_EXPR_DIRECT_INIT (t))
13477 flags = LOOKUP_NORMAL;
13478 return perform_implicit_conversion_flags (type, expr, complain,
13485 tsubst (TREE_TYPE (t), args, complain, in_decl),
13486 RECUR (TREE_OPERAND (t, 0)));
13489 case REINTERPRET_CAST_EXPR:
13490 case CONST_CAST_EXPR:
13491 case DYNAMIC_CAST_EXPR:
13492 case STATIC_CAST_EXPR:
13497 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
13498 if (integral_constant_expression_p
13499 && !cast_valid_in_integral_constant_expression_p (type))
13501 if (complain & tf_error)
13502 error ("a cast to a type other than an integral or "
13503 "enumeration type cannot appear in a constant-expression");
13504 return error_mark_node;
13507 op = RECUR (TREE_OPERAND (t, 0));
13509 switch (TREE_CODE (t))
13512 return build_functional_cast (type, op, complain);
13513 case REINTERPRET_CAST_EXPR:
13514 return build_reinterpret_cast (type, op, complain);
13515 case CONST_CAST_EXPR:
13516 return build_const_cast (type, op, complain);
13517 case DYNAMIC_CAST_EXPR:
13518 return build_dynamic_cast (type, op, complain);
13519 case STATIC_CAST_EXPR:
13520 return build_static_cast (type, op, complain);
13522 gcc_unreachable ();
13526 case POSTDECREMENT_EXPR:
13527 case POSTINCREMENT_EXPR:
13528 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
13529 args, complain, in_decl);
13530 return build_x_unary_op (TREE_CODE (t), op1, complain);
13532 case PREDECREMENT_EXPR:
13533 case PREINCREMENT_EXPR:
13537 case TRUTH_NOT_EXPR:
13538 case UNARY_PLUS_EXPR: /* Unary + */
13539 case REALPART_EXPR:
13540 case IMAGPART_EXPR:
13541 return build_x_unary_op (TREE_CODE (t), RECUR (TREE_OPERAND (t, 0)),
13544 case FIX_TRUNC_EXPR:
13545 return cp_build_unary_op (FIX_TRUNC_EXPR, RECUR (TREE_OPERAND (t, 0)),
13549 op1 = TREE_OPERAND (t, 0);
13550 if (TREE_CODE (op1) == LABEL_DECL)
13551 return finish_label_address_expr (DECL_NAME (op1),
13552 EXPR_LOCATION (op1));
13553 if (TREE_CODE (op1) == SCOPE_REF)
13554 op1 = tsubst_qualified_id (op1, args, complain, in_decl,
13555 /*done=*/true, /*address_p=*/true);
13557 op1 = tsubst_non_call_postfix_expression (op1, args, complain,
13559 return build_x_unary_op (ADDR_EXPR, op1, complain);
13564 case TRUNC_DIV_EXPR:
13565 case CEIL_DIV_EXPR:
13566 case FLOOR_DIV_EXPR:
13567 case ROUND_DIV_EXPR:
13568 case EXACT_DIV_EXPR:
13572 case TRUNC_MOD_EXPR:
13573 case FLOOR_MOD_EXPR:
13574 case TRUTH_ANDIF_EXPR:
13575 case TRUTH_ORIF_EXPR:
13576 case TRUTH_AND_EXPR:
13577 case TRUTH_OR_EXPR:
13593 tree r = build_x_binary_op
13595 RECUR (TREE_OPERAND (t, 0)),
13596 (TREE_NO_WARNING (TREE_OPERAND (t, 0))
13598 : TREE_CODE (TREE_OPERAND (t, 0))),
13599 RECUR (TREE_OPERAND (t, 1)),
13600 (TREE_NO_WARNING (TREE_OPERAND (t, 1))
13602 : TREE_CODE (TREE_OPERAND (t, 1))),
13605 if (EXPR_P (r) && TREE_NO_WARNING (t))
13606 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
13611 return tsubst_qualified_id (t, args, complain, in_decl, /*done=*/true,
13612 /*address_p=*/false);
13614 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
13615 args, complain, in_decl);
13616 return build_x_array_ref (op1, RECUR (TREE_OPERAND (t, 1)), complain);
13619 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
13620 return tsubst_copy (t, args, complain, in_decl);
13624 op1 = TREE_OPERAND (t, 0);
13627 /* When there are no ARGS, we are trying to evaluate a
13628 non-dependent expression from the parser. Trying to do
13629 the substitutions may not work. */
13631 op1 = TREE_TYPE (op1);
13635 ++cp_unevaluated_operand;
13636 ++c_inhibit_evaluation_warnings;
13637 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
13638 /*function_p=*/false,
13639 /*integral_constant_expression_p=*/false);
13640 --cp_unevaluated_operand;
13641 --c_inhibit_evaluation_warnings;
13644 return cxx_sizeof_or_alignof_type (op1, TREE_CODE (t),
13645 complain & tf_error);
13647 return cxx_sizeof_or_alignof_expr (op1, TREE_CODE (t),
13648 complain & tf_error);
13650 case AT_ENCODE_EXPR:
13652 op1 = TREE_OPERAND (t, 0);
13653 ++cp_unevaluated_operand;
13654 ++c_inhibit_evaluation_warnings;
13655 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
13656 /*function_p=*/false,
13657 /*integral_constant_expression_p=*/false);
13658 --cp_unevaluated_operand;
13659 --c_inhibit_evaluation_warnings;
13660 return objc_build_encode_expr (op1);
13663 case NOEXCEPT_EXPR:
13664 op1 = TREE_OPERAND (t, 0);
13665 ++cp_unevaluated_operand;
13666 ++c_inhibit_evaluation_warnings;
13667 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
13668 /*function_p=*/false,
13669 /*integral_constant_expression_p=*/false);
13670 --cp_unevaluated_operand;
13671 --c_inhibit_evaluation_warnings;
13672 return finish_noexcept_expr (op1, complain);
13676 tree r = build_x_modify_expr
13677 (RECUR (TREE_OPERAND (t, 0)),
13678 TREE_CODE (TREE_OPERAND (t, 1)),
13679 RECUR (TREE_OPERAND (t, 2)),
13681 /* TREE_NO_WARNING must be set if either the expression was
13682 parenthesized or it uses an operator such as >>= rather
13683 than plain assignment. In the former case, it was already
13684 set and must be copied. In the latter case,
13685 build_x_modify_expr sets it and it must not be reset
13687 if (TREE_NO_WARNING (t))
13688 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
13693 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
13694 args, complain, in_decl);
13695 /* Remember that there was a reference to this entity. */
13698 return build_x_arrow (op1);
13702 tree placement = RECUR (TREE_OPERAND (t, 0));
13703 tree init = RECUR (TREE_OPERAND (t, 3));
13704 VEC(tree,gc) *placement_vec;
13705 VEC(tree,gc) *init_vec;
13708 if (placement == NULL_TREE)
13709 placement_vec = NULL;
13712 placement_vec = make_tree_vector ();
13713 for (; placement != NULL_TREE; placement = TREE_CHAIN (placement))
13714 VEC_safe_push (tree, gc, placement_vec, TREE_VALUE (placement));
13717 /* If there was an initializer in the original tree, but it
13718 instantiated to an empty list, then we should pass a
13719 non-NULL empty vector to tell build_new that it was an
13720 empty initializer() rather than no initializer. This can
13721 only happen when the initializer is a pack expansion whose
13722 parameter packs are of length zero. */
13723 if (init == NULL_TREE && TREE_OPERAND (t, 3) == NULL_TREE)
13727 init_vec = make_tree_vector ();
13728 if (init == void_zero_node)
13729 gcc_assert (init_vec != NULL);
13732 for (; init != NULL_TREE; init = TREE_CHAIN (init))
13733 VEC_safe_push (tree, gc, init_vec, TREE_VALUE (init));
13737 ret = build_new (&placement_vec,
13738 tsubst (TREE_OPERAND (t, 1), args, complain, in_decl),
13739 RECUR (TREE_OPERAND (t, 2)),
13741 NEW_EXPR_USE_GLOBAL (t),
13744 if (placement_vec != NULL)
13745 release_tree_vector (placement_vec);
13746 if (init_vec != NULL)
13747 release_tree_vector (init_vec);
13753 return delete_sanity
13754 (RECUR (TREE_OPERAND (t, 0)),
13755 RECUR (TREE_OPERAND (t, 1)),
13756 DELETE_EXPR_USE_VEC (t),
13757 DELETE_EXPR_USE_GLOBAL (t),
13760 case COMPOUND_EXPR:
13761 return build_x_compound_expr (RECUR (TREE_OPERAND (t, 0)),
13762 RECUR (TREE_OPERAND (t, 1)),
13768 VEC(tree,gc) *call_args;
13769 unsigned int nargs, i;
13774 function = CALL_EXPR_FN (t);
13775 /* When we parsed the expression, we determined whether or
13776 not Koenig lookup should be performed. */
13777 koenig_p = KOENIG_LOOKUP_P (t);
13778 if (TREE_CODE (function) == SCOPE_REF)
13780 qualified_p = true;
13781 function = tsubst_qualified_id (function, args, complain, in_decl,
13783 /*address_p=*/false);
13785 else if (koenig_p && TREE_CODE (function) == IDENTIFIER_NODE)
13787 /* Do nothing; calling tsubst_copy_and_build on an identifier
13788 would incorrectly perform unqualified lookup again.
13790 Note that we can also have an IDENTIFIER_NODE if the earlier
13791 unqualified lookup found a member function; in that case
13792 koenig_p will be false and we do want to do the lookup
13793 again to find the instantiated member function.
13795 FIXME but doing that causes c++/15272, so we need to stop
13796 using IDENTIFIER_NODE in that situation. */
13797 qualified_p = false;
13801 if (TREE_CODE (function) == COMPONENT_REF)
13803 tree op = TREE_OPERAND (function, 1);
13805 qualified_p = (TREE_CODE (op) == SCOPE_REF
13806 || (BASELINK_P (op)
13807 && BASELINK_QUALIFIED_P (op)));
13810 qualified_p = false;
13812 function = tsubst_copy_and_build (function, args, complain,
13815 integral_constant_expression_p);
13817 if (BASELINK_P (function))
13818 qualified_p = true;
13821 nargs = call_expr_nargs (t);
13822 call_args = make_tree_vector ();
13823 for (i = 0; i < nargs; ++i)
13825 tree arg = CALL_EXPR_ARG (t, i);
13827 if (!PACK_EXPANSION_P (arg))
13828 VEC_safe_push (tree, gc, call_args,
13829 RECUR (CALL_EXPR_ARG (t, i)));
13832 /* Expand the pack expansion and push each entry onto
13834 arg = tsubst_pack_expansion (arg, args, complain, in_decl);
13835 if (TREE_CODE (arg) == TREE_VEC)
13837 unsigned int len, j;
13839 len = TREE_VEC_LENGTH (arg);
13840 for (j = 0; j < len; ++j)
13842 tree value = TREE_VEC_ELT (arg, j);
13843 if (value != NULL_TREE)
13844 value = convert_from_reference (value);
13845 VEC_safe_push (tree, gc, call_args, value);
13850 /* A partial substitution. Add one entry. */
13851 VEC_safe_push (tree, gc, call_args, arg);
13856 /* We do not perform argument-dependent lookup if normal
13857 lookup finds a non-function, in accordance with the
13858 expected resolution of DR 218. */
13860 && ((is_overloaded_fn (function)
13861 /* If lookup found a member function, the Koenig lookup is
13862 not appropriate, even if an unqualified-name was used
13863 to denote the function. */
13864 && !DECL_FUNCTION_MEMBER_P (get_first_fn (function)))
13865 || TREE_CODE (function) == IDENTIFIER_NODE)
13866 /* Only do this when substitution turns a dependent call
13867 into a non-dependent call. */
13868 && type_dependent_expression_p_push (t)
13869 && !any_type_dependent_arguments_p (call_args))
13870 function = perform_koenig_lookup (function, call_args, false,
13873 if (TREE_CODE (function) == IDENTIFIER_NODE
13874 && !any_type_dependent_arguments_p (call_args))
13876 if (koenig_p && (complain & tf_warning_or_error))
13878 /* For backwards compatibility and good diagnostics, try
13879 the unqualified lookup again if we aren't in SFINAE
13881 tree unq = (tsubst_copy_and_build
13882 (function, args, complain, in_decl, true,
13883 integral_constant_expression_p));
13884 if (unq == error_mark_node)
13885 return error_mark_node;
13887 if (unq != function)
13890 if (TREE_CODE (fn) == INDIRECT_REF)
13891 fn = TREE_OPERAND (fn, 0);
13892 if (TREE_CODE (fn) == COMPONENT_REF)
13893 fn = TREE_OPERAND (fn, 1);
13894 if (is_overloaded_fn (fn))
13895 fn = get_first_fn (fn);
13896 permerror (EXPR_LOC_OR_HERE (t),
13897 "%qD was not declared in this scope, "
13898 "and no declarations were found by "
13899 "argument-dependent lookup at the point "
13900 "of instantiation", function);
13902 /* Can't say anything more. */;
13903 else if (DECL_CLASS_SCOPE_P (fn))
13905 inform (EXPR_LOC_OR_HERE (t),
13906 "declarations in dependent base %qT are "
13907 "not found by unqualified lookup",
13908 DECL_CLASS_CONTEXT (fn));
13909 if (current_class_ptr)
13910 inform (EXPR_LOC_OR_HERE (t),
13911 "use %<this->%D%> instead", function);
13913 inform (EXPR_LOC_OR_HERE (t),
13914 "use %<%T::%D%> instead",
13915 current_class_name, function);
13918 inform (0, "%q+D declared here, later in the "
13919 "translation unit", fn);
13923 if (TREE_CODE (function) == IDENTIFIER_NODE)
13925 unqualified_name_lookup_error (function);
13926 release_tree_vector (call_args);
13927 return error_mark_node;
13931 /* Remember that there was a reference to this entity. */
13932 if (DECL_P (function))
13933 mark_used (function);
13935 if (TREE_CODE (function) == OFFSET_REF)
13936 ret = build_offset_ref_call_from_tree (function, &call_args);
13937 else if (TREE_CODE (function) == COMPONENT_REF)
13939 tree instance = TREE_OPERAND (function, 0);
13940 tree fn = TREE_OPERAND (function, 1);
13942 if (processing_template_decl
13943 && (type_dependent_expression_p (instance)
13944 || (!BASELINK_P (fn)
13945 && TREE_CODE (fn) != FIELD_DECL)
13946 || type_dependent_expression_p (fn)
13947 || any_type_dependent_arguments_p (call_args)))
13948 ret = build_nt_call_vec (function, call_args);
13949 else if (!BASELINK_P (fn))
13950 ret = finish_call_expr (function, &call_args,
13951 /*disallow_virtual=*/false,
13952 /*koenig_p=*/false,
13955 ret = (build_new_method_call
13957 &call_args, NULL_TREE,
13958 qualified_p ? LOOKUP_NONVIRTUAL : LOOKUP_NORMAL,
13963 ret = finish_call_expr (function, &call_args,
13964 /*disallow_virtual=*/qualified_p,
13968 release_tree_vector (call_args);
13974 return build_x_conditional_expr
13975 (RECUR (TREE_OPERAND (t, 0)),
13976 RECUR (TREE_OPERAND (t, 1)),
13977 RECUR (TREE_OPERAND (t, 2)),
13980 case PSEUDO_DTOR_EXPR:
13981 return finish_pseudo_destructor_expr
13982 (RECUR (TREE_OPERAND (t, 0)),
13983 RECUR (TREE_OPERAND (t, 1)),
13984 tsubst (TREE_OPERAND (t, 2), args, complain, in_decl));
13988 tree purpose, value, chain;
13990 if (t == void_list_node)
13993 if ((TREE_PURPOSE (t) && PACK_EXPANSION_P (TREE_PURPOSE (t)))
13994 || (TREE_VALUE (t) && PACK_EXPANSION_P (TREE_VALUE (t))))
13996 /* We have pack expansions, so expand those and
13997 create a new list out of it. */
13998 tree purposevec = NULL_TREE;
13999 tree valuevec = NULL_TREE;
14003 /* Expand the argument expressions. */
14004 if (TREE_PURPOSE (t))
14005 purposevec = tsubst_pack_expansion (TREE_PURPOSE (t), args,
14006 complain, in_decl);
14007 if (TREE_VALUE (t))
14008 valuevec = tsubst_pack_expansion (TREE_VALUE (t), args,
14009 complain, in_decl);
14011 /* Build the rest of the list. */
14012 chain = TREE_CHAIN (t);
14013 if (chain && chain != void_type_node)
14014 chain = RECUR (chain);
14016 /* Determine the number of arguments. */
14017 if (purposevec && TREE_CODE (purposevec) == TREE_VEC)
14019 len = TREE_VEC_LENGTH (purposevec);
14020 gcc_assert (!valuevec || len == TREE_VEC_LENGTH (valuevec));
14022 else if (TREE_CODE (valuevec) == TREE_VEC)
14023 len = TREE_VEC_LENGTH (valuevec);
14026 /* Since we only performed a partial substitution into
14027 the argument pack, we only return a single list
14029 if (purposevec == TREE_PURPOSE (t)
14030 && valuevec == TREE_VALUE (t)
14031 && chain == TREE_CHAIN (t))
14034 return tree_cons (purposevec, valuevec, chain);
14037 /* Convert the argument vectors into a TREE_LIST */
14041 /* Grab the Ith values. */
14043 purpose = purposevec ? TREE_VEC_ELT (purposevec, i)
14046 = valuevec ? convert_from_reference (TREE_VEC_ELT (valuevec, i))
14049 /* Build the list (backwards). */
14050 chain = tree_cons (purpose, value, chain);
14056 purpose = TREE_PURPOSE (t);
14058 purpose = RECUR (purpose);
14059 value = TREE_VALUE (t);
14061 value = RECUR (value);
14062 chain = TREE_CHAIN (t);
14063 if (chain && chain != void_type_node)
14064 chain = RECUR (chain);
14065 if (purpose == TREE_PURPOSE (t)
14066 && value == TREE_VALUE (t)
14067 && chain == TREE_CHAIN (t))
14069 return tree_cons (purpose, value, chain);
14072 case COMPONENT_REF:
14078 object = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
14079 args, complain, in_decl);
14080 /* Remember that there was a reference to this entity. */
14081 if (DECL_P (object))
14082 mark_used (object);
14083 object_type = TREE_TYPE (object);
14085 member = TREE_OPERAND (t, 1);
14086 if (BASELINK_P (member))
14087 member = tsubst_baselink (member,
14088 non_reference (TREE_TYPE (object)),
14089 args, complain, in_decl);
14091 member = tsubst_copy (member, args, complain, in_decl);
14092 if (member == error_mark_node)
14093 return error_mark_node;
14095 if (type_dependent_expression_p (object))
14096 /* We can't do much here. */;
14097 else if (!CLASS_TYPE_P (object_type))
14099 if (SCALAR_TYPE_P (object_type))
14101 tree s = NULL_TREE;
14102 tree dtor = member;
14104 if (TREE_CODE (dtor) == SCOPE_REF)
14106 s = TREE_OPERAND (dtor, 0);
14107 dtor = TREE_OPERAND (dtor, 1);
14109 if (TREE_CODE (dtor) == BIT_NOT_EXPR)
14111 dtor = TREE_OPERAND (dtor, 0);
14113 return finish_pseudo_destructor_expr (object, s, dtor);
14117 else if (TREE_CODE (member) == SCOPE_REF
14118 && TREE_CODE (TREE_OPERAND (member, 1)) == TEMPLATE_ID_EXPR)
14120 /* Lookup the template functions now that we know what the
14122 tree scope = TREE_OPERAND (member, 0);
14123 tree tmpl = TREE_OPERAND (TREE_OPERAND (member, 1), 0);
14124 tree args = TREE_OPERAND (TREE_OPERAND (member, 1), 1);
14125 member = lookup_qualified_name (scope, tmpl,
14126 /*is_type_p=*/false,
14127 /*complain=*/false);
14128 if (BASELINK_P (member))
14130 BASELINK_FUNCTIONS (member)
14131 = build_nt (TEMPLATE_ID_EXPR, BASELINK_FUNCTIONS (member),
14133 member = (adjust_result_of_qualified_name_lookup
14134 (member, BINFO_TYPE (BASELINK_BINFO (member)),
14139 qualified_name_lookup_error (scope, tmpl, member,
14141 return error_mark_node;
14144 else if (TREE_CODE (member) == SCOPE_REF
14145 && !CLASS_TYPE_P (TREE_OPERAND (member, 0))
14146 && TREE_CODE (TREE_OPERAND (member, 0)) != NAMESPACE_DECL)
14148 if (complain & tf_error)
14150 if (TYPE_P (TREE_OPERAND (member, 0)))
14151 error ("%qT is not a class or namespace",
14152 TREE_OPERAND (member, 0));
14154 error ("%qD is not a class or namespace",
14155 TREE_OPERAND (member, 0));
14157 return error_mark_node;
14159 else if (TREE_CODE (member) == FIELD_DECL)
14160 return finish_non_static_data_member (member, object, NULL_TREE);
14162 return finish_class_member_access_expr (object, member,
14163 /*template_p=*/false,
14169 (RECUR (TREE_OPERAND (t, 0)));
14173 VEC(constructor_elt,gc) *n;
14174 constructor_elt *ce;
14175 unsigned HOST_WIDE_INT idx;
14176 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
14177 bool process_index_p;
14179 bool need_copy_p = false;
14182 if (type == error_mark_node)
14183 return error_mark_node;
14185 /* digest_init will do the wrong thing if we let it. */
14186 if (type && TYPE_PTRMEMFUNC_P (type))
14189 /* We do not want to process the index of aggregate
14190 initializers as they are identifier nodes which will be
14191 looked up by digest_init. */
14192 process_index_p = !(type && MAYBE_CLASS_TYPE_P (type));
14194 n = VEC_copy (constructor_elt, gc, CONSTRUCTOR_ELTS (t));
14195 newlen = VEC_length (constructor_elt, n);
14196 FOR_EACH_VEC_ELT (constructor_elt, n, idx, ce)
14198 if (ce->index && process_index_p)
14199 ce->index = RECUR (ce->index);
14201 if (PACK_EXPANSION_P (ce->value))
14203 /* Substitute into the pack expansion. */
14204 ce->value = tsubst_pack_expansion (ce->value, args, complain,
14207 if (ce->value == error_mark_node
14208 || PACK_EXPANSION_P (ce->value))
14210 else if (TREE_VEC_LENGTH (ce->value) == 1)
14211 /* Just move the argument into place. */
14212 ce->value = TREE_VEC_ELT (ce->value, 0);
14215 /* Update the length of the final CONSTRUCTOR
14216 arguments vector, and note that we will need to
14218 newlen = newlen + TREE_VEC_LENGTH (ce->value) - 1;
14219 need_copy_p = true;
14223 ce->value = RECUR (ce->value);
14228 VEC(constructor_elt,gc) *old_n = n;
14230 n = VEC_alloc (constructor_elt, gc, newlen);
14231 FOR_EACH_VEC_ELT (constructor_elt, old_n, idx, ce)
14233 if (TREE_CODE (ce->value) == TREE_VEC)
14235 int i, len = TREE_VEC_LENGTH (ce->value);
14236 for (i = 0; i < len; ++i)
14237 CONSTRUCTOR_APPEND_ELT (n, 0,
14238 TREE_VEC_ELT (ce->value, i));
14241 CONSTRUCTOR_APPEND_ELT (n, 0, ce->value);
14245 r = build_constructor (init_list_type_node, n);
14246 CONSTRUCTOR_IS_DIRECT_INIT (r) = CONSTRUCTOR_IS_DIRECT_INIT (t);
14248 if (TREE_HAS_CONSTRUCTOR (t))
14249 return finish_compound_literal (type, r, complain);
14251 TREE_TYPE (r) = type;
14257 tree operand_0 = TREE_OPERAND (t, 0);
14258 if (TYPE_P (operand_0))
14260 operand_0 = tsubst (operand_0, args, complain, in_decl);
14261 return get_typeid (operand_0);
14265 operand_0 = RECUR (operand_0);
14266 return build_typeid (operand_0);
14277 tree r = tsubst_copy (t, args, complain, in_decl);
14279 if (TREE_CODE (TREE_TYPE (t)) != REFERENCE_TYPE)
14280 /* If the original type was a reference, we'll be wrapped in
14281 the appropriate INDIRECT_REF. */
14282 r = convert_from_reference (r);
14287 return build_x_va_arg (RECUR (TREE_OPERAND (t, 0)),
14288 tsubst (TREE_TYPE (t), args, complain, in_decl));
14290 case OFFSETOF_EXPR:
14291 return finish_offsetof (RECUR (TREE_OPERAND (t, 0)));
14295 tree type1 = tsubst_copy (TRAIT_EXPR_TYPE1 (t), args,
14296 complain, in_decl);
14298 tree type2 = TRAIT_EXPR_TYPE2 (t);
14300 type2 = tsubst_copy (type2, args, complain, in_decl);
14302 return finish_trait_expr (TRAIT_EXPR_KIND (t), type1, type2);
14307 tree old_stmt_expr = cur_stmt_expr;
14308 tree stmt_expr = begin_stmt_expr ();
14310 cur_stmt_expr = stmt_expr;
14311 tsubst_expr (STMT_EXPR_STMT (t), args, complain, in_decl,
14312 integral_constant_expression_p);
14313 stmt_expr = finish_stmt_expr (stmt_expr, false);
14314 cur_stmt_expr = old_stmt_expr;
14316 /* If the resulting list of expression statement is empty,
14317 fold it further into void_zero_node. */
14318 if (empty_expr_stmt_p (stmt_expr))
14319 stmt_expr = void_zero_node;
14325 t = tsubst_copy (t, args, complain, in_decl);
14326 /* As in finish_id_expression, we resolve enumeration constants
14327 to their underlying values. */
14328 if (TREE_CODE (t) == CONST_DECL && !processing_template_decl)
14330 used_types_insert (TREE_TYPE (t));
14331 return DECL_INITIAL (t);
14337 tree r = build_lambda_expr ();
14339 tree type = tsubst (LAMBDA_EXPR_CLOSURE (t), args, complain, NULL_TREE);
14340 LAMBDA_EXPR_CLOSURE (r) = type;
14341 CLASSTYPE_LAMBDA_EXPR (type) = r;
14343 LAMBDA_EXPR_LOCATION (r)
14344 = LAMBDA_EXPR_LOCATION (t);
14345 LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (r)
14346 = LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (t);
14347 LAMBDA_EXPR_MUTABLE_P (r) = LAMBDA_EXPR_MUTABLE_P (t);
14348 LAMBDA_EXPR_DISCRIMINATOR (r)
14349 = (LAMBDA_EXPR_DISCRIMINATOR (t));
14350 LAMBDA_EXPR_EXTRA_SCOPE (r)
14351 = RECUR (LAMBDA_EXPR_EXTRA_SCOPE (t));
14352 if (LAMBDA_EXPR_RETURN_TYPE (t) == dependent_lambda_return_type_node)
14354 LAMBDA_EXPR_RETURN_TYPE (r) = dependent_lambda_return_type_node;
14355 LAMBDA_EXPR_DEDUCE_RETURN_TYPE_P (r) = true;
14358 LAMBDA_EXPR_RETURN_TYPE (r)
14359 = tsubst (LAMBDA_EXPR_RETURN_TYPE (t), args, complain, in_decl);
14361 gcc_assert (LAMBDA_EXPR_THIS_CAPTURE (t) == NULL_TREE
14362 && LAMBDA_EXPR_PENDING_PROXIES (t) == NULL);
14364 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
14365 determine_visibility (TYPE_NAME (type));
14366 /* Now that we know visibility, instantiate the type so we have a
14367 declaration of the op() for later calls to lambda_function. */
14368 complete_type (type);
14370 /* The capture list refers to closure members, so this needs to
14371 wait until after we finish instantiating the type. */
14372 LAMBDA_EXPR_CAPTURE_LIST (r)
14373 = RECUR (LAMBDA_EXPR_CAPTURE_LIST (t));
14375 return build_lambda_object (r);
14379 /* We can get here for a constant initializer of non-dependent type.
14380 FIXME stop folding in cp_parser_initializer_clause. */
14381 gcc_assert (TREE_CONSTANT (t));
14383 tree r = get_target_expr (RECUR (TARGET_EXPR_INITIAL (t)));
14384 TREE_CONSTANT (r) = true;
14388 case TRANSACTION_EXPR:
14389 return tsubst_expr(t, args, complain, in_decl,
14390 integral_constant_expression_p);
14393 /* Handle Objective-C++ constructs, if appropriate. */
14396 = objcp_tsubst_copy_and_build (t, args, complain,
14397 in_decl, /*function_p=*/false);
14401 return tsubst_copy (t, args, complain, in_decl);
14407 /* Verify that the instantiated ARGS are valid. For type arguments,
14408 make sure that the type's linkage is ok. For non-type arguments,
14409 make sure they are constants if they are integral or enumerations.
14410 Emit an error under control of COMPLAIN, and return TRUE on error. */
14413 check_instantiated_arg (tree tmpl, tree t, tsubst_flags_t complain)
14415 if (ARGUMENT_PACK_P (t))
14417 tree vec = ARGUMENT_PACK_ARGS (t);
14418 int len = TREE_VEC_LENGTH (vec);
14419 bool result = false;
14422 for (i = 0; i < len; ++i)
14423 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (vec, i), complain))
14427 else if (TYPE_P (t))
14429 /* [basic.link]: A name with no linkage (notably, the name
14430 of a class or enumeration declared in a local scope)
14431 shall not be used to declare an entity with linkage.
14432 This implies that names with no linkage cannot be used as
14435 DR 757 relaxes this restriction for C++0x. */
14436 tree nt = (cxx_dialect > cxx98 ? NULL_TREE
14437 : no_linkage_check (t, /*relaxed_p=*/false));
14441 /* DR 488 makes use of a type with no linkage cause
14442 type deduction to fail. */
14443 if (complain & tf_error)
14445 if (TYPE_ANONYMOUS_P (nt))
14446 error ("%qT is/uses anonymous type", t);
14448 error ("template argument for %qD uses local type %qT",
14453 /* In order to avoid all sorts of complications, we do not
14454 allow variably-modified types as template arguments. */
14455 else if (variably_modified_type_p (t, NULL_TREE))
14457 if (complain & tf_error)
14458 error ("%qT is a variably modified type", t);
14462 /* A non-type argument of integral or enumerated type must be a
14464 else if (TREE_TYPE (t)
14465 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t))
14466 && !TREE_CONSTANT (t))
14468 if (complain & tf_error)
14469 error ("integral expression %qE is not constant", t);
14476 check_instantiated_args (tree tmpl, tree args, tsubst_flags_t complain)
14478 int ix, len = DECL_NTPARMS (tmpl);
14479 bool result = false;
14481 for (ix = 0; ix != len; ix++)
14483 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (args, ix), complain))
14486 if (result && (complain & tf_error))
14487 error (" trying to instantiate %qD", tmpl);
14491 /* In C++0x, it's possible to have a function template whose type depends
14492 on itself recursively. This is most obvious with decltype, but can also
14493 occur with enumeration scope (c++/48969). So we need to catch infinite
14494 recursion and reject the substitution at deduction time; this function
14495 will return error_mark_node for any repeated substitution.
14497 This also catches excessive recursion such as when f<N> depends on
14498 f<N-1> across all integers, and returns error_mark_node for all the
14499 substitutions back up to the initial one.
14501 This is, of course, not reentrant. */
14504 deduction_tsubst_fntype (tree fn, tree targs, tsubst_flags_t complain)
14506 static bool excessive_deduction_depth;
14507 static int deduction_depth;
14508 struct pending_template *old_last_pend = last_pending_template;
14509 struct tinst_level *old_error_tinst = last_error_tinst_level;
14511 tree fntype = TREE_TYPE (fn);
14515 if (excessive_deduction_depth)
14516 return error_mark_node;
14518 tinst = build_tree_list (fn, targs);
14519 if (!push_tinst_level (tinst))
14521 excessive_deduction_depth = true;
14523 return error_mark_node;
14526 input_location = DECL_SOURCE_LOCATION (fn);
14528 push_deduction_access_scope (fn);
14529 r = tsubst (fntype, targs, complain, NULL_TREE);
14530 pop_deduction_access_scope (fn);
14533 if (excessive_deduction_depth)
14535 r = error_mark_node;
14536 if (deduction_depth == 0)
14537 /* Reset once we're all the way out. */
14538 excessive_deduction_depth = false;
14541 pop_tinst_level ();
14542 /* We can't free this if a pending_template entry or last_error_tinst_level
14543 is pointing at it. */
14544 if (last_pending_template == old_last_pend
14545 && last_error_tinst_level == old_error_tinst)
14550 /* Instantiate the indicated variable or function template TMPL with
14551 the template arguments in TARG_PTR. */
14554 instantiate_template_1 (tree tmpl, tree orig_args, tsubst_flags_t complain)
14556 tree targ_ptr = orig_args;
14561 if (tmpl == error_mark_node)
14562 return error_mark_node;
14564 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
14566 /* If this function is a clone, handle it specially. */
14567 if (DECL_CLONED_FUNCTION_P (tmpl))
14572 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
14573 DECL_CLONED_FUNCTION. */
14574 spec = instantiate_template (DECL_ABSTRACT_ORIGIN (tmpl),
14575 targ_ptr, complain);
14576 if (spec == error_mark_node)
14577 return error_mark_node;
14579 /* Look for the clone. */
14580 FOR_EACH_CLONE (clone, spec)
14581 if (DECL_NAME (clone) == DECL_NAME (tmpl))
14583 /* We should always have found the clone by now. */
14584 gcc_unreachable ();
14588 /* Check to see if we already have this specialization. */
14589 gen_tmpl = most_general_template (tmpl);
14590 if (tmpl != gen_tmpl)
14591 /* The TMPL is a partial instantiation. To get a full set of
14592 arguments we must add the arguments used to perform the
14593 partial instantiation. */
14594 targ_ptr = add_outermost_template_args (DECL_TI_ARGS (tmpl),
14597 /* It would be nice to avoid hashing here and then again in tsubst_decl,
14598 but it doesn't seem to be on the hot path. */
14599 spec = retrieve_specialization (gen_tmpl, targ_ptr, 0);
14601 gcc_assert (tmpl == gen_tmpl
14602 || ((fndecl = retrieve_specialization (tmpl, orig_args, 0))
14604 || fndecl == NULL_TREE);
14606 if (spec != NULL_TREE)
14609 if (check_instantiated_args (gen_tmpl, INNERMOST_TEMPLATE_ARGS (targ_ptr),
14611 return error_mark_node;
14613 /* We are building a FUNCTION_DECL, during which the access of its
14614 parameters and return types have to be checked. However this
14615 FUNCTION_DECL which is the desired context for access checking
14616 is not built yet. We solve this chicken-and-egg problem by
14617 deferring all checks until we have the FUNCTION_DECL. */
14618 push_deferring_access_checks (dk_deferred);
14620 /* Instantiation of the function happens in the context of the function
14621 template, not the context of the overload resolution we're doing. */
14622 push_to_top_level ();
14623 if (DECL_CLASS_SCOPE_P (gen_tmpl))
14625 tree ctx = tsubst (DECL_CONTEXT (gen_tmpl), targ_ptr,
14626 complain, gen_tmpl);
14627 push_nested_class (ctx);
14629 /* Substitute template parameters to obtain the specialization. */
14630 fndecl = tsubst (DECL_TEMPLATE_RESULT (gen_tmpl),
14631 targ_ptr, complain, gen_tmpl);
14632 if (DECL_CLASS_SCOPE_P (gen_tmpl))
14633 pop_nested_class ();
14634 pop_from_top_level ();
14636 if (fndecl == error_mark_node)
14637 return error_mark_node;
14639 /* Now we know the specialization, compute access previously
14641 push_access_scope (fndecl);
14643 /* Some typedefs referenced from within the template code need to be access
14644 checked at template instantiation time, i.e now. These types were
14645 added to the template at parsing time. Let's get those and perfom
14646 the acces checks then. */
14647 perform_typedefs_access_check (DECL_TEMPLATE_RESULT (tmpl), targ_ptr);
14648 perform_deferred_access_checks ();
14649 pop_access_scope (fndecl);
14650 pop_deferring_access_checks ();
14652 /* The DECL_TI_TEMPLATE should always be the immediate parent
14653 template, not the most general template. */
14654 DECL_TI_TEMPLATE (fndecl) = tmpl;
14656 /* If we've just instantiated the main entry point for a function,
14657 instantiate all the alternate entry points as well. We do this
14658 by cloning the instantiation of the main entry point, not by
14659 instantiating the template clones. */
14660 if (DECL_CHAIN (gen_tmpl) && DECL_CLONED_FUNCTION_P (DECL_CHAIN (gen_tmpl)))
14661 clone_function_decl (fndecl, /*update_method_vec_p=*/0);
14666 /* Wrapper for instantiate_template_1. */
14669 instantiate_template (tree tmpl, tree orig_args, tsubst_flags_t complain)
14672 timevar_push (TV_TEMPLATE_INST);
14673 ret = instantiate_template_1 (tmpl, orig_args, complain);
14674 timevar_pop (TV_TEMPLATE_INST);
14678 /* We're going to do deduction substitution on the type of TMPL, a function
14679 template. In C++11 mode, push into that access scope. In C++03 mode,
14680 disable access checking. */
14683 push_deduction_access_scope (tree tmpl)
14685 if (cxx_dialect >= cxx0x)
14687 int ptd = processing_template_decl;
14688 push_access_scope (DECL_TEMPLATE_RESULT (tmpl));
14689 /* Preserve processing_template_decl across push_to_top_level. */
14690 if (ptd && !processing_template_decl)
14691 ++processing_template_decl;
14694 push_deferring_access_checks (dk_no_check);
14697 /* And pop back out. */
14700 pop_deduction_access_scope (tree tmpl)
14702 if (cxx_dialect >= cxx0x)
14703 pop_access_scope (DECL_TEMPLATE_RESULT (tmpl));
14705 pop_deferring_access_checks ();
14708 /* PARM is a template parameter pack for FN. Returns true iff
14709 PARM is used in a deducible way in the argument list of FN. */
14712 pack_deducible_p (tree parm, tree fn)
14714 tree t = FUNCTION_FIRST_USER_PARMTYPE (fn);
14715 for (; t; t = TREE_CHAIN (t))
14717 tree type = TREE_VALUE (t);
14719 if (!PACK_EXPANSION_P (type))
14721 for (packs = PACK_EXPANSION_PARAMETER_PACKS (type);
14722 packs; packs = TREE_CHAIN (packs))
14723 if (TREE_VALUE (packs) == parm)
14725 /* The template parameter pack is used in a function parameter
14726 pack. If this is the end of the parameter list, the
14727 template parameter pack is deducible. */
14728 if (TREE_CHAIN (t) == void_list_node)
14731 /* Otherwise, not. Well, it could be deduced from
14732 a non-pack parameter, but doing so would end up with
14733 a deduction mismatch, so don't bother. */
14737 /* The template parameter pack isn't used in any function parameter
14738 packs, but it might be used deeper, e.g. tuple<Args...>. */
14742 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
14743 NARGS elements of the arguments that are being used when calling
14744 it. TARGS is a vector into which the deduced template arguments
14747 Return zero for success, 2 for an incomplete match that doesn't resolve
14748 all the types, and 1 for complete failure. An error message will be
14749 printed only for an incomplete match.
14751 If FN is a conversion operator, or we are trying to produce a specific
14752 specialization, RETURN_TYPE is the return type desired.
14754 The EXPLICIT_TARGS are explicit template arguments provided via a
14757 The parameter STRICT is one of:
14760 We are deducing arguments for a function call, as in
14761 [temp.deduct.call].
14764 We are deducing arguments for a conversion function, as in
14765 [temp.deduct.conv].
14768 We are deducing arguments when doing an explicit instantiation
14769 as in [temp.explicit], when determining an explicit specialization
14770 as in [temp.expl.spec], or when taking the address of a function
14771 template, as in [temp.deduct.funcaddr]. */
14774 fn_type_unification (tree fn,
14775 tree explicit_targs,
14778 unsigned int nargs,
14780 unification_kind_t strict,
14788 gcc_assert (TREE_CODE (fn) == TEMPLATE_DECL);
14790 fntype = TREE_TYPE (fn);
14791 if (explicit_targs)
14795 The specified template arguments must match the template
14796 parameters in kind (i.e., type, nontype, template), and there
14797 must not be more arguments than there are parameters;
14798 otherwise type deduction fails.
14800 Nontype arguments must match the types of the corresponding
14801 nontype template parameters, or must be convertible to the
14802 types of the corresponding nontype parameters as specified in
14803 _temp.arg.nontype_, otherwise type deduction fails.
14805 All references in the function type of the function template
14806 to the corresponding template parameters are replaced by the
14807 specified template argument values. If a substitution in a
14808 template parameter or in the function type of the function
14809 template results in an invalid type, type deduction fails. */
14810 tree tparms = DECL_INNERMOST_TEMPLATE_PARMS (fn);
14811 int i, len = TREE_VEC_LENGTH (tparms);
14812 tree converted_args;
14813 bool incomplete = false;
14815 if (explicit_targs == error_mark_node)
14816 return unify_invalid (explain_p);
14819 = (coerce_template_parms (tparms, explicit_targs, NULL_TREE,
14821 ? tf_warning_or_error
14823 /*require_all_args=*/false,
14824 /*use_default_args=*/false));
14825 if (converted_args == error_mark_node)
14828 /* Substitute the explicit args into the function type. This is
14829 necessary so that, for instance, explicitly declared function
14830 arguments can match null pointed constants. If we were given
14831 an incomplete set of explicit args, we must not do semantic
14832 processing during substitution as we could create partial
14834 for (i = 0; i < len; i++)
14836 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
14837 bool parameter_pack = false;
14838 tree targ = TREE_VEC_ELT (converted_args, i);
14840 /* Dig out the actual parm. */
14841 if (TREE_CODE (parm) == TYPE_DECL
14842 || TREE_CODE (parm) == TEMPLATE_DECL)
14844 parm = TREE_TYPE (parm);
14845 parameter_pack = TEMPLATE_TYPE_PARAMETER_PACK (parm);
14847 else if (TREE_CODE (parm) == PARM_DECL)
14849 parm = DECL_INITIAL (parm);
14850 parameter_pack = TEMPLATE_PARM_PARAMETER_PACK (parm);
14853 if (!parameter_pack && targ == NULL_TREE)
14854 /* No explicit argument for this template parameter. */
14857 if (parameter_pack && pack_deducible_p (parm, fn))
14859 /* Mark the argument pack as "incomplete". We could
14860 still deduce more arguments during unification.
14861 We remove this mark in type_unification_real. */
14864 ARGUMENT_PACK_INCOMPLETE_P(targ) = 1;
14865 ARGUMENT_PACK_EXPLICIT_ARGS (targ)
14866 = ARGUMENT_PACK_ARGS (targ);
14869 /* We have some incomplete argument packs. */
14874 processing_template_decl += incomplete;
14875 fntype = deduction_tsubst_fntype (fn, converted_args,
14877 ? tf_warning_or_error
14879 processing_template_decl -= incomplete;
14881 if (fntype == error_mark_node)
14884 /* Place the explicitly specified arguments in TARGS. */
14885 for (i = NUM_TMPL_ARGS (converted_args); i--;)
14886 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (converted_args, i);
14889 /* Never do unification on the 'this' parameter. */
14890 parms = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (fntype));
14896 parms = tree_cons (NULL_TREE, TREE_TYPE (fntype), parms);
14897 new_args = XALLOCAVEC (tree, nargs + 1);
14898 new_args[0] = return_type;
14899 memcpy (new_args + 1, args, nargs * sizeof (tree));
14904 /* We allow incomplete unification without an error message here
14905 because the standard doesn't seem to explicitly prohibit it. Our
14906 callers must be ready to deal with unification failures in any
14908 result = type_unification_real (DECL_INNERMOST_TEMPLATE_PARMS (fn),
14909 targs, parms, args, nargs, /*subr=*/0,
14910 strict, flags, explain_p);
14912 /* Now that we have bindings for all of the template arguments,
14913 ensure that the arguments deduced for the template template
14914 parameters have compatible template parameter lists. We cannot
14915 check this property before we have deduced all template
14916 arguments, because the template parameter types of a template
14917 template parameter might depend on prior template parameters
14918 deduced after the template template parameter. The following
14919 ill-formed example illustrates this issue:
14921 template<typename T, template<T> class C> void f(C<5>, T);
14923 template<int N> struct X {};
14926 f(X<5>(), 5l); // error: template argument deduction fails
14929 The template parameter list of 'C' depends on the template type
14930 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
14931 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
14932 time that we deduce 'C'. */
14934 && !template_template_parm_bindings_ok_p
14935 (DECL_INNERMOST_TEMPLATE_PARMS (fn), targs))
14936 return unify_inconsistent_template_template_parameters (explain_p);
14939 /* All is well so far. Now, check:
14943 When all template arguments have been deduced, all uses of
14944 template parameters in nondeduced contexts are replaced with
14945 the corresponding deduced argument values. If the
14946 substitution results in an invalid type, as described above,
14947 type deduction fails. */
14949 tree substed = deduction_tsubst_fntype (fn, targs,
14951 ? tf_warning_or_error
14953 if (substed == error_mark_node)
14956 /* If we're looking for an exact match, check that what we got
14957 is indeed an exact match. It might not be if some template
14958 parameters are used in non-deduced contexts. */
14959 if (strict == DEDUCE_EXACT)
14964 = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (substed));
14966 sarg = tree_cons (NULL_TREE, TREE_TYPE (substed), sarg);
14967 for (i = 0; i < nargs && sarg; ++i, sarg = TREE_CHAIN (sarg))
14968 if (!same_type_p (args[i], TREE_VALUE (sarg)))
14969 return unify_type_mismatch (explain_p, args[i],
14970 TREE_VALUE (sarg));
14977 /* Adjust types before performing type deduction, as described in
14978 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
14979 sections are symmetric. PARM is the type of a function parameter
14980 or the return type of the conversion function. ARG is the type of
14981 the argument passed to the call, or the type of the value
14982 initialized with the result of the conversion function.
14983 ARG_EXPR is the original argument expression, which may be null. */
14986 maybe_adjust_types_for_deduction (unification_kind_t strict,
15000 /* Swap PARM and ARG throughout the remainder of this
15001 function; the handling is precisely symmetric since PARM
15002 will initialize ARG rather than vice versa. */
15010 /* Core issue #873: Do the DR606 thing (see below) for these cases,
15011 too, but here handle it by stripping the reference from PARM
15012 rather than by adding it to ARG. */
15013 if (TREE_CODE (*parm) == REFERENCE_TYPE
15014 && TYPE_REF_IS_RVALUE (*parm)
15015 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
15016 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
15017 && TREE_CODE (*arg) == REFERENCE_TYPE
15018 && !TYPE_REF_IS_RVALUE (*arg))
15019 *parm = TREE_TYPE (*parm);
15020 /* Nothing else to do in this case. */
15024 gcc_unreachable ();
15027 if (TREE_CODE (*parm) != REFERENCE_TYPE)
15029 /* [temp.deduct.call]
15031 If P is not a reference type:
15033 --If A is an array type, the pointer type produced by the
15034 array-to-pointer standard conversion (_conv.array_) is
15035 used in place of A for type deduction; otherwise,
15037 --If A is a function type, the pointer type produced by
15038 the function-to-pointer standard conversion
15039 (_conv.func_) is used in place of A for type deduction;
15042 --If A is a cv-qualified type, the top level
15043 cv-qualifiers of A's type are ignored for type
15045 if (TREE_CODE (*arg) == ARRAY_TYPE)
15046 *arg = build_pointer_type (TREE_TYPE (*arg));
15047 else if (TREE_CODE (*arg) == FUNCTION_TYPE)
15048 *arg = build_pointer_type (*arg);
15050 *arg = TYPE_MAIN_VARIANT (*arg);
15053 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
15054 of the form T&&, where T is a template parameter, and the argument
15055 is an lvalue, T is deduced as A& */
15056 if (TREE_CODE (*parm) == REFERENCE_TYPE
15057 && TYPE_REF_IS_RVALUE (*parm)
15058 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
15059 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
15060 && (arg_expr ? real_lvalue_p (arg_expr)
15061 /* try_one_overload doesn't provide an arg_expr, but
15062 functions are always lvalues. */
15063 : TREE_CODE (*arg) == FUNCTION_TYPE))
15064 *arg = build_reference_type (*arg);
15066 /* [temp.deduct.call]
15068 If P is a cv-qualified type, the top level cv-qualifiers
15069 of P's type are ignored for type deduction. If P is a
15070 reference type, the type referred to by P is used for
15072 *parm = TYPE_MAIN_VARIANT (*parm);
15073 if (TREE_CODE (*parm) == REFERENCE_TYPE)
15075 *parm = TREE_TYPE (*parm);
15076 result |= UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
15079 /* DR 322. For conversion deduction, remove a reference type on parm
15080 too (which has been swapped into ARG). */
15081 if (strict == DEDUCE_CONV && TREE_CODE (*arg) == REFERENCE_TYPE)
15082 *arg = TREE_TYPE (*arg);
15087 /* Subroutine of unify_one_argument. PARM is a function parameter of a
15088 template which does contain any deducible template parameters; check if
15089 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
15090 unify_one_argument. */
15093 check_non_deducible_conversion (tree parm, tree arg, int strict,
15094 int flags, bool explain_p)
15099 type = TREE_TYPE (arg);
15103 if (same_type_p (parm, type))
15104 return unify_success (explain_p);
15106 if (strict == DEDUCE_CONV)
15108 if (can_convert_arg (type, parm, NULL_TREE, flags))
15109 return unify_success (explain_p);
15111 else if (strict != DEDUCE_EXACT)
15113 if (can_convert_arg (parm, type,
15114 TYPE_P (arg) ? NULL_TREE : arg,
15116 return unify_success (explain_p);
15119 if (strict == DEDUCE_EXACT)
15120 return unify_type_mismatch (explain_p, parm, arg);
15122 return unify_arg_conversion (explain_p, parm, type, arg);
15125 /* Subroutine of type_unification_real and unify_pack_expansion to
15126 handle unification of a single P/A pair. Parameters are as
15127 for those functions. */
15130 unify_one_argument (tree tparms, tree targs, tree parm, tree arg,
15131 int subr, unification_kind_t strict, int flags,
15134 tree arg_expr = NULL_TREE;
15137 if (arg == error_mark_node || parm == error_mark_node)
15138 return unify_invalid (explain_p);
15139 if (arg == unknown_type_node)
15140 /* We can't deduce anything from this, but we might get all the
15141 template args from other function args. */
15142 return unify_success (explain_p);
15144 /* FIXME uses_deducible_template_parms */
15145 if (TYPE_P (parm) && !uses_template_parms (parm))
15146 return check_non_deducible_conversion (parm, arg, strict, flags,
15152 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
15153 | UNIFY_ALLOW_MORE_CV_QUAL
15154 | UNIFY_ALLOW_DERIVED);
15158 arg_strict = UNIFY_ALLOW_LESS_CV_QUAL;
15162 arg_strict = UNIFY_ALLOW_NONE;
15166 gcc_unreachable ();
15169 /* We only do these transformations if this is the top-level
15170 parameter_type_list in a call or declaration matching; in other
15171 situations (nested function declarators, template argument lists) we
15172 won't be comparing a type to an expression, and we don't do any type
15178 gcc_assert (TREE_TYPE (arg) != NULL_TREE);
15179 if (type_unknown_p (arg))
15181 /* [temp.deduct.type] A template-argument can be
15182 deduced from a pointer to function or pointer
15183 to member function argument if the set of
15184 overloaded functions does not contain function
15185 templates and at most one of a set of
15186 overloaded functions provides a unique
15189 if (resolve_overloaded_unification
15190 (tparms, targs, parm, arg, strict,
15191 arg_strict, explain_p))
15192 return unify_success (explain_p);
15193 return unify_overload_resolution_failure (explain_p, arg);
15197 arg = unlowered_expr_type (arg);
15198 if (arg == error_mark_node)
15199 return unify_invalid (explain_p);
15203 maybe_adjust_types_for_deduction (strict, &parm, &arg, arg_expr);
15206 gcc_assert ((TYPE_P (parm) || TREE_CODE (parm) == TEMPLATE_DECL)
15207 == (TYPE_P (arg) || TREE_CODE (arg) == TEMPLATE_DECL));
15209 /* For deduction from an init-list we need the actual list. */
15210 if (arg_expr && BRACE_ENCLOSED_INITIALIZER_P (arg_expr))
15212 return unify (tparms, targs, parm, arg, arg_strict, explain_p);
15215 /* Most parms like fn_type_unification.
15217 If SUBR is 1, we're being called recursively (to unify the
15218 arguments of a function or method parameter of a function
15222 type_unification_real (tree tparms,
15226 unsigned int xnargs,
15228 unification_kind_t strict,
15234 int ntparms = TREE_VEC_LENGTH (tparms);
15235 int saw_undeduced = 0;
15238 unsigned int nargs;
15241 gcc_assert (TREE_CODE (tparms) == TREE_VEC);
15242 gcc_assert (xparms == NULL_TREE || TREE_CODE (xparms) == TREE_LIST);
15243 gcc_assert (ntparms > 0);
15245 /* Reset the number of non-defaulted template arguments contained
15247 NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs) = NULL_TREE;
15255 while (parms && parms != void_list_node
15258 parm = TREE_VALUE (parms);
15260 if (TREE_CODE (parm) == TYPE_PACK_EXPANSION
15261 && (!TREE_CHAIN (parms) || TREE_CHAIN (parms) == void_list_node))
15262 /* For a function parameter pack that occurs at the end of the
15263 parameter-declaration-list, the type A of each remaining
15264 argument of the call is compared with the type P of the
15265 declarator-id of the function parameter pack. */
15268 parms = TREE_CHAIN (parms);
15270 if (TREE_CODE (parm) == TYPE_PACK_EXPANSION)
15271 /* For a function parameter pack that does not occur at the
15272 end of the parameter-declaration-list, the type of the
15273 parameter pack is a non-deduced context. */
15279 if (unify_one_argument (tparms, targs, parm, arg, subr, strict,
15285 && parms != void_list_node
15286 && TREE_CODE (TREE_VALUE (parms)) == TYPE_PACK_EXPANSION)
15288 /* Unify the remaining arguments with the pack expansion type. */
15290 tree parmvec = make_tree_vec (1);
15292 /* Allocate a TREE_VEC and copy in all of the arguments */
15293 argvec = make_tree_vec (nargs - ia);
15294 for (i = 0; ia < nargs; ++ia, ++i)
15295 TREE_VEC_ELT (argvec, i) = args[ia];
15297 /* Copy the parameter into parmvec. */
15298 TREE_VEC_ELT (parmvec, 0) = TREE_VALUE (parms);
15299 if (unify_pack_expansion (tparms, targs, parmvec, argvec, strict,
15300 /*subr=*/subr, explain_p))
15303 /* Advance to the end of the list of parameters. */
15304 parms = TREE_CHAIN (parms);
15307 /* Fail if we've reached the end of the parm list, and more args
15308 are present, and the parm list isn't variadic. */
15309 if (ia < nargs && parms == void_list_node)
15310 return unify_too_many_arguments (explain_p, nargs, ia);
15311 /* Fail if parms are left and they don't have default values. */
15312 if (parms && parms != void_list_node
15313 && TREE_PURPOSE (parms) == NULL_TREE)
15315 unsigned int count = nargs;
15317 while (p && p != void_list_node)
15320 p = TREE_CHAIN (p);
15322 return unify_too_few_arguments (explain_p, ia, count);
15327 tsubst_flags_t complain = (explain_p
15328 ? tf_warning_or_error
15331 /* Check to see if we need another pass before we start clearing
15332 ARGUMENT_PACK_INCOMPLETE_P. */
15333 for (i = 0; i < ntparms; i++)
15335 tree targ = TREE_VEC_ELT (targs, i);
15336 tree tparm = TREE_VEC_ELT (tparms, i);
15338 if (targ || tparm == error_mark_node)
15340 tparm = TREE_VALUE (tparm);
15342 /* If this is an undeduced nontype parameter that depends on
15343 a type parameter, try another pass; its type may have been
15344 deduced from a later argument than the one from which
15345 this parameter can be deduced. */
15346 if (TREE_CODE (tparm) == PARM_DECL
15347 && uses_template_parms (TREE_TYPE (tparm))
15348 && !saw_undeduced++)
15352 for (i = 0; i < ntparms; i++)
15354 tree targ = TREE_VEC_ELT (targs, i);
15355 tree tparm = TREE_VEC_ELT (tparms, i);
15357 /* Clear the "incomplete" flags on all argument packs now so that
15358 substituting them into later default arguments works. */
15359 if (targ && ARGUMENT_PACK_P (targ))
15361 ARGUMENT_PACK_INCOMPLETE_P (targ) = 0;
15362 ARGUMENT_PACK_EXPLICIT_ARGS (targ) = NULL_TREE;
15365 if (targ || tparm == error_mark_node)
15367 tparm = TREE_VALUE (tparm);
15369 /* Core issue #226 (C++0x) [temp.deduct]:
15371 If a template argument has not been deduced, its
15372 default template argument, if any, is used.
15374 When we are in C++98 mode, TREE_PURPOSE will either
15375 be NULL_TREE or ERROR_MARK_NODE, so we do not need
15376 to explicitly check cxx_dialect here. */
15377 if (TREE_PURPOSE (TREE_VEC_ELT (tparms, i)))
15379 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
15380 tree arg = TREE_PURPOSE (TREE_VEC_ELT (tparms, i));
15381 location_t save_loc = input_location;
15383 input_location = DECL_SOURCE_LOCATION (parm);
15384 arg = tsubst_template_arg (arg, targs, complain, NULL_TREE);
15385 arg = convert_template_argument (parm, arg, targs, complain,
15387 input_location = save_loc;
15388 if (arg == error_mark_node)
15392 TREE_VEC_ELT (targs, i) = arg;
15393 /* The position of the first default template argument,
15394 is also the number of non-defaulted arguments in TARGS.
15396 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs))
15397 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, i);
15402 /* If the type parameter is a parameter pack, then it will
15403 be deduced to an empty parameter pack. */
15404 if (template_parameter_pack_p (tparm))
15408 if (TREE_CODE (tparm) == TEMPLATE_PARM_INDEX)
15410 arg = make_node (NONTYPE_ARGUMENT_PACK);
15411 TREE_TYPE (arg) = TREE_TYPE (TEMPLATE_PARM_DECL (tparm));
15412 TREE_CONSTANT (arg) = 1;
15415 arg = cxx_make_type (TYPE_ARGUMENT_PACK);
15417 SET_ARGUMENT_PACK_ARGS (arg, make_tree_vec (0));
15419 TREE_VEC_ELT (targs, i) = arg;
15423 return unify_parameter_deduction_failure (explain_p, tparm);
15426 #ifdef ENABLE_CHECKING
15427 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs))
15428 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, TREE_VEC_LENGTH (targs));
15431 return unify_success (explain_p);
15434 /* Subroutine of type_unification_real. Args are like the variables
15435 at the call site. ARG is an overloaded function (or template-id);
15436 we try deducing template args from each of the overloads, and if
15437 only one succeeds, we go with that. Modifies TARGS and returns
15438 true on success. */
15441 resolve_overloaded_unification (tree tparms,
15445 unification_kind_t strict,
15449 tree tempargs = copy_node (targs);
15451 tree goodfn = NULL_TREE;
15454 if (TREE_CODE (arg) == ADDR_EXPR)
15456 arg = TREE_OPERAND (arg, 0);
15462 if (TREE_CODE (arg) == COMPONENT_REF)
15463 /* Handle `&x' where `x' is some static or non-static member
15465 arg = TREE_OPERAND (arg, 1);
15467 if (TREE_CODE (arg) == OFFSET_REF)
15468 arg = TREE_OPERAND (arg, 1);
15470 /* Strip baselink information. */
15471 if (BASELINK_P (arg))
15472 arg = BASELINK_FUNCTIONS (arg);
15474 if (TREE_CODE (arg) == TEMPLATE_ID_EXPR)
15476 /* If we got some explicit template args, we need to plug them into
15477 the affected templates before we try to unify, in case the
15478 explicit args will completely resolve the templates in question. */
15481 tree expl_subargs = TREE_OPERAND (arg, 1);
15482 arg = TREE_OPERAND (arg, 0);
15484 for (; arg; arg = OVL_NEXT (arg))
15486 tree fn = OVL_CURRENT (arg);
15487 tree subargs, elem;
15489 if (TREE_CODE (fn) != TEMPLATE_DECL)
15492 ++processing_template_decl;
15493 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
15494 expl_subargs, /*check_ret=*/false);
15495 if (subargs && !any_dependent_template_arguments_p (subargs))
15497 elem = tsubst (TREE_TYPE (fn), subargs, tf_none, NULL_TREE);
15498 if (try_one_overload (tparms, targs, tempargs, parm,
15499 elem, strict, sub_strict, addr_p, explain_p)
15500 && (!goodfn || !same_type_p (goodfn, elem)))
15508 --processing_template_decl;
15510 /* If no templates (or more than one) are fully resolved by the
15511 explicit arguments, this template-id is a non-deduced context; it
15512 could still be OK if we deduce all template arguments for the
15513 enclosing call through other arguments. */
15517 else if (TREE_CODE (arg) != OVERLOAD
15518 && TREE_CODE (arg) != FUNCTION_DECL)
15519 /* If ARG is, for example, "(0, &f)" then its type will be unknown
15520 -- but the deduction does not succeed because the expression is
15521 not just the function on its own. */
15524 for (; arg; arg = OVL_NEXT (arg))
15525 if (try_one_overload (tparms, targs, tempargs, parm,
15526 TREE_TYPE (OVL_CURRENT (arg)),
15527 strict, sub_strict, addr_p, explain_p)
15528 && (!goodfn || !decls_match (goodfn, OVL_CURRENT (arg))))
15530 goodfn = OVL_CURRENT (arg);
15534 /* [temp.deduct.type] A template-argument can be deduced from a pointer
15535 to function or pointer to member function argument if the set of
15536 overloaded functions does not contain function templates and at most
15537 one of a set of overloaded functions provides a unique match.
15539 So if we found multiple possibilities, we return success but don't
15540 deduce anything. */
15544 int i = TREE_VEC_LENGTH (targs);
15546 if (TREE_VEC_ELT (tempargs, i))
15547 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (tempargs, i);
15555 /* Core DR 115: In contexts where deduction is done and fails, or in
15556 contexts where deduction is not done, if a template argument list is
15557 specified and it, along with any default template arguments, identifies
15558 a single function template specialization, then the template-id is an
15559 lvalue for the function template specialization. */
15562 resolve_nondeduced_context (tree orig_expr)
15564 tree expr, offset, baselink;
15567 if (!type_unknown_p (orig_expr))
15572 offset = NULL_TREE;
15573 baselink = NULL_TREE;
15575 if (TREE_CODE (expr) == ADDR_EXPR)
15577 expr = TREE_OPERAND (expr, 0);
15580 if (TREE_CODE (expr) == OFFSET_REF)
15583 expr = TREE_OPERAND (expr, 1);
15585 if (BASELINK_P (expr))
15588 expr = BASELINK_FUNCTIONS (expr);
15591 if (TREE_CODE (expr) == TEMPLATE_ID_EXPR)
15594 tree goodfn = NULL_TREE;
15596 /* If we got some explicit template args, we need to plug them into
15597 the affected templates before we try to unify, in case the
15598 explicit args will completely resolve the templates in question. */
15600 tree expl_subargs = TREE_OPERAND (expr, 1);
15601 tree arg = TREE_OPERAND (expr, 0);
15602 tree badfn = NULL_TREE;
15603 tree badargs = NULL_TREE;
15605 for (; arg; arg = OVL_NEXT (arg))
15607 tree fn = OVL_CURRENT (arg);
15608 tree subargs, elem;
15610 if (TREE_CODE (fn) != TEMPLATE_DECL)
15613 ++processing_template_decl;
15614 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
15615 expl_subargs, /*check_ret=*/false);
15616 if (subargs && !any_dependent_template_arguments_p (subargs))
15618 elem = instantiate_template (fn, subargs, tf_none);
15619 if (elem == error_mark_node)
15624 else if (elem && (!goodfn || !decls_match (goodfn, elem)))
15630 --processing_template_decl;
15634 mark_used (goodfn);
15637 expr = build_baselink (BASELINK_BINFO (baselink),
15638 BASELINK_ACCESS_BINFO (baselink),
15639 expr, BASELINK_OPTYPE (baselink));
15643 = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (offset, 0)));
15644 expr = build_offset_ref (base, expr, addr);
15647 expr = cp_build_addr_expr (expr, tf_warning_or_error);
15650 else if (good == 0 && badargs)
15651 /* There were no good options and at least one bad one, so let the
15652 user know what the problem is. */
15653 instantiate_template (badfn, badargs, tf_warning_or_error);
15658 /* Subroutine of resolve_overloaded_unification; does deduction for a single
15659 overload. Fills TARGS with any deduced arguments, or error_mark_node if
15660 different overloads deduce different arguments for a given parm.
15661 ADDR_P is true if the expression for which deduction is being
15662 performed was of the form "& fn" rather than simply "fn".
15664 Returns 1 on success. */
15667 try_one_overload (tree tparms,
15672 unification_kind_t strict,
15681 /* [temp.deduct.type] A template-argument can be deduced from a pointer
15682 to function or pointer to member function argument if the set of
15683 overloaded functions does not contain function templates and at most
15684 one of a set of overloaded functions provides a unique match.
15686 So if this is a template, just return success. */
15688 if (uses_template_parms (arg))
15691 if (TREE_CODE (arg) == METHOD_TYPE)
15692 arg = build_ptrmemfunc_type (build_pointer_type (arg));
15694 arg = build_pointer_type (arg);
15696 sub_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg, NULL);
15698 /* We don't copy orig_targs for this because if we have already deduced
15699 some template args from previous args, unify would complain when we
15700 try to deduce a template parameter for the same argument, even though
15701 there isn't really a conflict. */
15702 nargs = TREE_VEC_LENGTH (targs);
15703 tempargs = make_tree_vec (nargs);
15705 if (unify (tparms, tempargs, parm, arg, sub_strict, explain_p))
15708 /* First make sure we didn't deduce anything that conflicts with
15709 explicitly specified args. */
15710 for (i = nargs; i--; )
15712 tree elt = TREE_VEC_ELT (tempargs, i);
15713 tree oldelt = TREE_VEC_ELT (orig_targs, i);
15717 else if (uses_template_parms (elt))
15718 /* Since we're unifying against ourselves, we will fill in
15719 template args used in the function parm list with our own
15720 template parms. Discard them. */
15721 TREE_VEC_ELT (tempargs, i) = NULL_TREE;
15722 else if (oldelt && !template_args_equal (oldelt, elt))
15726 for (i = nargs; i--; )
15728 tree elt = TREE_VEC_ELT (tempargs, i);
15731 TREE_VEC_ELT (targs, i) = elt;
15737 /* PARM is a template class (perhaps with unbound template
15738 parameters). ARG is a fully instantiated type. If ARG can be
15739 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
15740 TARGS are as for unify. */
15743 try_class_unification (tree tparms, tree targs, tree parm, tree arg,
15746 tree copy_of_targs;
15748 if (!CLASSTYPE_TEMPLATE_INFO (arg)
15749 || (most_general_template (CLASSTYPE_TI_TEMPLATE (arg))
15750 != most_general_template (CLASSTYPE_TI_TEMPLATE (parm))))
15753 /* We need to make a new template argument vector for the call to
15754 unify. If we used TARGS, we'd clutter it up with the result of
15755 the attempted unification, even if this class didn't work out.
15756 We also don't want to commit ourselves to all the unifications
15757 we've already done, since unification is supposed to be done on
15758 an argument-by-argument basis. In other words, consider the
15759 following pathological case:
15761 template <int I, int J, int K>
15764 template <int I, int J>
15765 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
15767 template <int I, int J, int K>
15768 void f(S<I, J, K>, S<I, I, I>);
15777 Now, by the time we consider the unification involving `s2', we
15778 already know that we must have `f<0, 0, 0>'. But, even though
15779 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
15780 because there are two ways to unify base classes of S<0, 1, 2>
15781 with S<I, I, I>. If we kept the already deduced knowledge, we
15782 would reject the possibility I=1. */
15783 copy_of_targs = make_tree_vec (TREE_VEC_LENGTH (targs));
15785 /* If unification failed, we're done. */
15786 if (unify (tparms, copy_of_targs, CLASSTYPE_TI_ARGS (parm),
15787 CLASSTYPE_TI_ARGS (arg), UNIFY_ALLOW_NONE, explain_p))
15793 /* Given a template type PARM and a class type ARG, find the unique
15794 base type in ARG that is an instance of PARM. We do not examine
15795 ARG itself; only its base-classes. If there is not exactly one
15796 appropriate base class, return NULL_TREE. PARM may be the type of
15797 a partial specialization, as well as a plain template type. Used
15800 static enum template_base_result
15801 get_template_base (tree tparms, tree targs, tree parm, tree arg,
15802 bool explain_p, tree *result)
15804 tree rval = NULL_TREE;
15807 gcc_assert (RECORD_OR_UNION_CODE_P (TREE_CODE (arg)));
15809 binfo = TYPE_BINFO (complete_type (arg));
15812 /* The type could not be completed. */
15813 *result = NULL_TREE;
15814 return tbr_incomplete_type;
15817 /* Walk in inheritance graph order. The search order is not
15818 important, and this avoids multiple walks of virtual bases. */
15819 for (binfo = TREE_CHAIN (binfo); binfo; binfo = TREE_CHAIN (binfo))
15821 tree r = try_class_unification (tparms, targs, parm,
15822 BINFO_TYPE (binfo), explain_p);
15826 /* If there is more than one satisfactory baseclass, then:
15830 If they yield more than one possible deduced A, the type
15834 if (rval && !same_type_p (r, rval))
15836 *result = NULL_TREE;
15837 return tbr_ambiguous_baseclass;
15845 return tbr_success;
15848 /* Returns the level of DECL, which declares a template parameter. */
15851 template_decl_level (tree decl)
15853 switch (TREE_CODE (decl))
15856 case TEMPLATE_DECL:
15857 return TEMPLATE_TYPE_LEVEL (TREE_TYPE (decl));
15860 return TEMPLATE_PARM_LEVEL (DECL_INITIAL (decl));
15863 gcc_unreachable ();
15868 /* Decide whether ARG can be unified with PARM, considering only the
15869 cv-qualifiers of each type, given STRICT as documented for unify.
15870 Returns nonzero iff the unification is OK on that basis. */
15873 check_cv_quals_for_unify (int strict, tree arg, tree parm)
15875 int arg_quals = cp_type_quals (arg);
15876 int parm_quals = cp_type_quals (parm);
15878 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
15879 && !(strict & UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
15881 /* Although a CVR qualifier is ignored when being applied to a
15882 substituted template parameter ([8.3.2]/1 for example), that
15883 does not allow us to unify "const T" with "int&" because both
15884 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
15885 It is ok when we're allowing additional CV qualifiers
15886 at the outer level [14.8.2.1]/3,1st bullet. */
15887 if ((TREE_CODE (arg) == REFERENCE_TYPE
15888 || TREE_CODE (arg) == FUNCTION_TYPE
15889 || TREE_CODE (arg) == METHOD_TYPE)
15890 && (parm_quals & (TYPE_QUAL_CONST | TYPE_QUAL_VOLATILE)))
15893 if ((!POINTER_TYPE_P (arg) && TREE_CODE (arg) != TEMPLATE_TYPE_PARM)
15894 && (parm_quals & TYPE_QUAL_RESTRICT))
15898 if (!(strict & (UNIFY_ALLOW_MORE_CV_QUAL | UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
15899 && (arg_quals & parm_quals) != parm_quals)
15902 if (!(strict & (UNIFY_ALLOW_LESS_CV_QUAL | UNIFY_ALLOW_OUTER_LESS_CV_QUAL))
15903 && (parm_quals & arg_quals) != arg_quals)
15909 /* Determines the LEVEL and INDEX for the template parameter PARM. */
15911 template_parm_level_and_index (tree parm, int* level, int* index)
15913 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
15914 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
15915 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
15917 *index = TEMPLATE_TYPE_IDX (parm);
15918 *level = TEMPLATE_TYPE_LEVEL (parm);
15922 *index = TEMPLATE_PARM_IDX (parm);
15923 *level = TEMPLATE_PARM_LEVEL (parm);
15927 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
15929 if (unify (TP, TA, P, A, S, EP)) \
15933 /* Unifies the remaining arguments in PACKED_ARGS with the pack
15934 expansion at the end of PACKED_PARMS. Returns 0 if the type
15935 deduction succeeds, 1 otherwise. STRICT is the same as in
15936 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
15937 call argument list. We'll need to adjust the arguments to make them
15938 types. SUBR tells us if this is from a recursive call to
15939 type_unification_real, or for comparing two template argument
15943 unify_pack_expansion (tree tparms, tree targs, tree packed_parms,
15944 tree packed_args, unification_kind_t strict,
15945 bool subr, bool explain_p)
15948 = TREE_VEC_ELT (packed_parms, TREE_VEC_LENGTH (packed_parms) - 1);
15949 tree pattern = PACK_EXPANSION_PATTERN (parm);
15950 tree pack, packs = NULL_TREE;
15951 int i, start = TREE_VEC_LENGTH (packed_parms) - 1;
15952 int len = TREE_VEC_LENGTH (packed_args);
15954 /* Determine the parameter packs we will be deducing from the
15955 pattern, and record their current deductions. */
15956 for (pack = PACK_EXPANSION_PARAMETER_PACKS (parm);
15957 pack; pack = TREE_CHAIN (pack))
15959 tree parm_pack = TREE_VALUE (pack);
15962 /* Determine the index and level of this parameter pack. */
15963 template_parm_level_and_index (parm_pack, &level, &idx);
15965 /* Keep track of the parameter packs and their corresponding
15967 packs = tree_cons (parm_pack, TMPL_ARG (targs, level, idx), packs);
15968 TREE_TYPE (packs) = make_tree_vec (len - start);
15971 /* Loop through all of the arguments that have not yet been
15972 unified and unify each with the pattern. */
15973 for (i = start; i < len; i++)
15976 bool any_explicit = false;
15977 tree arg = TREE_VEC_ELT (packed_args, i);
15979 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
15980 or the element of its argument pack at the current index if
15981 this argument was explicitly specified. */
15982 for (pack = packs; pack; pack = TREE_CHAIN (pack))
15986 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
15989 if (TREE_VALUE (pack)
15990 && (pargs = ARGUMENT_PACK_EXPLICIT_ARGS (TREE_VALUE (pack)))
15991 && (i < TREE_VEC_LENGTH (pargs)))
15993 any_explicit = true;
15994 arg = TREE_VEC_ELT (pargs, i);
15996 TMPL_ARG (targs, level, idx) = arg;
15999 /* If we had explicit template arguments, substitute them into the
16000 pattern before deduction. */
16003 /* Some arguments might still be unspecified or dependent. */
16005 ++processing_template_decl;
16006 dependent = any_dependent_template_arguments_p (targs);
16008 --processing_template_decl;
16009 parm = tsubst (pattern, targs,
16010 explain_p ? tf_warning_or_error : tf_none,
16013 --processing_template_decl;
16014 if (parm == error_mark_node)
16020 /* Unify the pattern with the current argument. */
16021 if (unify_one_argument (tparms, targs, parm, arg, subr, strict,
16022 LOOKUP_IMPLICIT, explain_p))
16025 /* For each parameter pack, collect the deduced value. */
16026 for (pack = packs; pack; pack = TREE_CHAIN (pack))
16029 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
16031 TREE_VEC_ELT (TREE_TYPE (pack), i - start) =
16032 TMPL_ARG (targs, level, idx);
16036 /* Verify that the results of unification with the parameter packs
16037 produce results consistent with what we've seen before, and make
16038 the deduced argument packs available. */
16039 for (pack = packs; pack; pack = TREE_CHAIN (pack))
16041 tree old_pack = TREE_VALUE (pack);
16042 tree new_args = TREE_TYPE (pack);
16043 int i, len = TREE_VEC_LENGTH (new_args);
16045 bool nondeduced_p = false;
16047 /* By default keep the original deduced argument pack.
16048 If necessary, more specific code is going to update the
16049 resulting deduced argument later down in this function. */
16050 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
16051 TMPL_ARG (targs, level, idx) = old_pack;
16053 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
16054 actually deduce anything. */
16055 for (i = 0; i < len && !nondeduced_p; ++i)
16056 if (TREE_VEC_ELT (new_args, i) == NULL_TREE)
16057 nondeduced_p = true;
16061 if (old_pack && ARGUMENT_PACK_INCOMPLETE_P (old_pack))
16063 /* If we had fewer function args than explicit template args,
16064 just use the explicits. */
16065 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
16066 int explicit_len = TREE_VEC_LENGTH (explicit_args);
16067 if (len < explicit_len)
16068 new_args = explicit_args;
16074 /* Build the deduced *_ARGUMENT_PACK. */
16075 if (TREE_CODE (TREE_PURPOSE (pack)) == TEMPLATE_PARM_INDEX)
16077 result = make_node (NONTYPE_ARGUMENT_PACK);
16078 TREE_TYPE (result) =
16079 TREE_TYPE (TEMPLATE_PARM_DECL (TREE_PURPOSE (pack)));
16080 TREE_CONSTANT (result) = 1;
16083 result = cxx_make_type (TYPE_ARGUMENT_PACK);
16085 SET_ARGUMENT_PACK_ARGS (result, new_args);
16087 /* Note the deduced argument packs for this parameter
16089 TMPL_ARG (targs, level, idx) = result;
16091 else if (ARGUMENT_PACK_INCOMPLETE_P (old_pack)
16092 && (ARGUMENT_PACK_ARGS (old_pack)
16093 == ARGUMENT_PACK_EXPLICIT_ARGS (old_pack)))
16095 /* We only had the explicitly-provided arguments before, but
16096 now we have a complete set of arguments. */
16097 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
16099 SET_ARGUMENT_PACK_ARGS (old_pack, new_args);
16100 ARGUMENT_PACK_INCOMPLETE_P (old_pack) = 1;
16101 ARGUMENT_PACK_EXPLICIT_ARGS (old_pack) = explicit_args;
16105 tree bad_old_arg = NULL_TREE, bad_new_arg = NULL_TREE;
16106 tree old_args = ARGUMENT_PACK_ARGS (old_pack);
16108 if (!comp_template_args_with_info (old_args, new_args,
16109 &bad_old_arg, &bad_new_arg))
16110 /* Inconsistent unification of this parameter pack. */
16111 return unify_parameter_pack_inconsistent (explain_p,
16117 return unify_success (explain_p);
16120 /* Deduce the value of template parameters. TPARMS is the (innermost)
16121 set of template parameters to a template. TARGS is the bindings
16122 for those template parameters, as determined thus far; TARGS may
16123 include template arguments for outer levels of template parameters
16124 as well. PARM is a parameter to a template function, or a
16125 subcomponent of that parameter; ARG is the corresponding argument.
16126 This function attempts to match PARM with ARG in a manner
16127 consistent with the existing assignments in TARGS. If more values
16128 are deduced, then TARGS is updated.
16130 Returns 0 if the type deduction succeeds, 1 otherwise. The
16131 parameter STRICT is a bitwise or of the following flags:
16134 Require an exact match between PARM and ARG.
16135 UNIFY_ALLOW_MORE_CV_QUAL:
16136 Allow the deduced ARG to be more cv-qualified (by qualification
16137 conversion) than ARG.
16138 UNIFY_ALLOW_LESS_CV_QUAL:
16139 Allow the deduced ARG to be less cv-qualified than ARG.
16140 UNIFY_ALLOW_DERIVED:
16141 Allow the deduced ARG to be a template base class of ARG,
16142 or a pointer to a template base class of the type pointed to by
16144 UNIFY_ALLOW_INTEGER:
16145 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
16146 case for more information.
16147 UNIFY_ALLOW_OUTER_LEVEL:
16148 This is the outermost level of a deduction. Used to determine validity
16149 of qualification conversions. A valid qualification conversion must
16150 have const qualified pointers leading up to the inner type which
16151 requires additional CV quals, except at the outer level, where const
16152 is not required [conv.qual]. It would be normal to set this flag in
16153 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
16154 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
16155 This is the outermost level of a deduction, and PARM can be more CV
16156 qualified at this point.
16157 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
16158 This is the outermost level of a deduction, and PARM can be less CV
16159 qualified at this point. */
16162 unify (tree tparms, tree targs, tree parm, tree arg, int strict,
16168 int strict_in = strict;
16170 /* I don't think this will do the right thing with respect to types.
16171 But the only case I've seen it in so far has been array bounds, where
16172 signedness is the only information lost, and I think that will be
16174 while (TREE_CODE (parm) == NOP_EXPR)
16175 parm = TREE_OPERAND (parm, 0);
16177 if (arg == error_mark_node)
16178 return unify_invalid (explain_p);
16179 if (arg == unknown_type_node
16180 || arg == init_list_type_node)
16181 /* We can't deduce anything from this, but we might get all the
16182 template args from other function args. */
16183 return unify_success (explain_p);
16185 /* If PARM uses template parameters, then we can't bail out here,
16186 even if ARG == PARM, since we won't record unifications for the
16187 template parameters. We might need them if we're trying to
16188 figure out which of two things is more specialized. */
16189 if (arg == parm && !uses_template_parms (parm))
16190 return unify_success (explain_p);
16192 /* Handle init lists early, so the rest of the function can assume
16193 we're dealing with a type. */
16194 if (BRACE_ENCLOSED_INITIALIZER_P (arg))
16198 tree orig_parm = parm;
16200 /* Replace T with std::initializer_list<T> for deduction. */
16201 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
16202 && flag_deduce_init_list)
16203 parm = listify (parm);
16205 if (!is_std_init_list (parm))
16206 /* We can only deduce from an initializer list argument if the
16207 parameter is std::initializer_list; otherwise this is a
16208 non-deduced context. */
16209 return unify_success (explain_p);
16211 elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (parm), 0);
16213 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg), i, elt)
16215 int elt_strict = strict;
16217 if (elt == error_mark_node)
16218 return unify_invalid (explain_p);
16220 if (!BRACE_ENCLOSED_INITIALIZER_P (elt))
16222 tree type = TREE_TYPE (elt);
16223 /* It should only be possible to get here for a call. */
16224 gcc_assert (elt_strict & UNIFY_ALLOW_OUTER_LEVEL);
16225 elt_strict |= maybe_adjust_types_for_deduction
16226 (DEDUCE_CALL, &elttype, &type, elt);
16230 RECUR_AND_CHECK_FAILURE (tparms, targs, elttype, elt, elt_strict,
16234 /* If the std::initializer_list<T> deduction worked, replace the
16235 deduced A with std::initializer_list<A>. */
16236 if (orig_parm != parm)
16238 idx = TEMPLATE_TYPE_IDX (orig_parm);
16239 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
16240 targ = listify (targ);
16241 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = targ;
16243 return unify_success (explain_p);
16246 /* Immediately reject some pairs that won't unify because of
16247 cv-qualification mismatches. */
16248 if (TREE_CODE (arg) == TREE_CODE (parm)
16250 /* It is the elements of the array which hold the cv quals of an array
16251 type, and the elements might be template type parms. We'll check
16252 when we recurse. */
16253 && TREE_CODE (arg) != ARRAY_TYPE
16254 /* We check the cv-qualifiers when unifying with template type
16255 parameters below. We want to allow ARG `const T' to unify with
16256 PARM `T' for example, when computing which of two templates
16257 is more specialized, for example. */
16258 && TREE_CODE (arg) != TEMPLATE_TYPE_PARM
16259 && !check_cv_quals_for_unify (strict_in, arg, parm))
16260 return unify_cv_qual_mismatch (explain_p, parm, arg);
16262 if (!(strict & UNIFY_ALLOW_OUTER_LEVEL)
16263 && TYPE_P (parm) && !CP_TYPE_CONST_P (parm))
16264 strict &= ~UNIFY_ALLOW_MORE_CV_QUAL;
16265 strict &= ~UNIFY_ALLOW_OUTER_LEVEL;
16266 strict &= ~UNIFY_ALLOW_DERIVED;
16267 strict &= ~UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
16268 strict &= ~UNIFY_ALLOW_OUTER_LESS_CV_QUAL;
16270 switch (TREE_CODE (parm))
16272 case TYPENAME_TYPE:
16274 case UNBOUND_CLASS_TEMPLATE:
16275 /* In a type which contains a nested-name-specifier, template
16276 argument values cannot be deduced for template parameters used
16277 within the nested-name-specifier. */
16278 return unify_success (explain_p);
16280 case TEMPLATE_TYPE_PARM:
16281 case TEMPLATE_TEMPLATE_PARM:
16282 case BOUND_TEMPLATE_TEMPLATE_PARM:
16283 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
16284 if (tparm == error_mark_node)
16285 return unify_invalid (explain_p);
16287 if (TEMPLATE_TYPE_LEVEL (parm)
16288 != template_decl_level (tparm))
16289 /* The PARM is not one we're trying to unify. Just check
16290 to see if it matches ARG. */
16292 if (TREE_CODE (arg) == TREE_CODE (parm)
16293 && same_type_p (parm, arg))
16294 return unify_success (explain_p);
16296 return unify_type_mismatch (explain_p, parm, arg);
16298 idx = TEMPLATE_TYPE_IDX (parm);
16299 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
16300 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, idx));
16301 if (tparm == error_mark_node)
16302 return unify_invalid (explain_p);
16304 /* Check for mixed types and values. */
16305 if ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
16306 && TREE_CODE (tparm) != TYPE_DECL)
16307 || (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
16308 && TREE_CODE (tparm) != TEMPLATE_DECL))
16309 gcc_unreachable ();
16311 if (TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
16313 /* ARG must be constructed from a template class or a template
16314 template parameter. */
16315 if (TREE_CODE (arg) != BOUND_TEMPLATE_TEMPLATE_PARM
16316 && !CLASSTYPE_SPECIALIZATION_OF_PRIMARY_TEMPLATE_P (arg))
16317 return unify_template_deduction_failure (explain_p, parm, arg);
16320 tree parmvec = TYPE_TI_ARGS (parm);
16321 tree argvec = INNERMOST_TEMPLATE_ARGS (TYPE_TI_ARGS (arg));
16322 tree full_argvec = add_to_template_args (targs, argvec);
16324 = DECL_INNERMOST_TEMPLATE_PARMS
16325 (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (parm));
16327 int parm_variadic_p = 0;
16329 /* The resolution to DR150 makes clear that default
16330 arguments for an N-argument may not be used to bind T
16331 to a template template parameter with fewer than N
16332 parameters. It is not safe to permit the binding of
16333 default arguments as an extension, as that may change
16334 the meaning of a conforming program. Consider:
16336 struct Dense { static const unsigned int dim = 1; };
16338 template <template <typename> class View,
16340 void operator+(float, View<Block> const&);
16342 template <typename Block,
16343 unsigned int Dim = Block::dim>
16344 struct Lvalue_proxy { operator float() const; };
16348 Lvalue_proxy<Dense> p;
16353 Here, if Lvalue_proxy is permitted to bind to View, then
16354 the global operator+ will be used; if they are not, the
16355 Lvalue_proxy will be converted to float. */
16356 if (coerce_template_parms (parm_parms,
16358 TYPE_TI_TEMPLATE (parm),
16360 ? tf_warning_or_error
16362 /*require_all_args=*/true,
16363 /*use_default_args=*/false)
16364 == error_mark_node)
16367 /* Deduce arguments T, i from TT<T> or TT<i>.
16368 We check each element of PARMVEC and ARGVEC individually
16369 rather than the whole TREE_VEC since they can have
16370 different number of elements. */
16372 parmvec = expand_template_argument_pack (parmvec);
16373 argvec = expand_template_argument_pack (argvec);
16375 len = TREE_VEC_LENGTH (parmvec);
16377 /* Check if the parameters end in a pack, making them
16380 && PACK_EXPANSION_P (TREE_VEC_ELT (parmvec, len - 1)))
16381 parm_variadic_p = 1;
16383 if (TREE_VEC_LENGTH (argvec) < len - parm_variadic_p)
16384 return unify_too_few_arguments (explain_p,
16385 TREE_VEC_LENGTH (argvec), len);
16387 for (i = 0; i < len - parm_variadic_p; ++i)
16389 RECUR_AND_CHECK_FAILURE (tparms, targs,
16390 TREE_VEC_ELT (parmvec, i),
16391 TREE_VEC_ELT (argvec, i),
16392 UNIFY_ALLOW_NONE, explain_p);
16395 if (parm_variadic_p
16396 && unify_pack_expansion (tparms, targs,
16399 /*subr=*/true, explain_p))
16402 arg = TYPE_TI_TEMPLATE (arg);
16404 /* Fall through to deduce template name. */
16407 if (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
16408 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
16410 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
16412 /* Simple cases: Value already set, does match or doesn't. */
16413 if (targ != NULL_TREE && template_args_equal (targ, arg))
16414 return unify_success (explain_p);
16416 return unify_inconsistency (explain_p, parm, targ, arg);
16420 /* If PARM is `const T' and ARG is only `int', we don't have
16421 a match unless we are allowing additional qualification.
16422 If ARG is `const int' and PARM is just `T' that's OK;
16423 that binds `const int' to `T'. */
16424 if (!check_cv_quals_for_unify (strict_in | UNIFY_ALLOW_LESS_CV_QUAL,
16426 return unify_cv_qual_mismatch (explain_p, parm, arg);
16428 /* Consider the case where ARG is `const volatile int' and
16429 PARM is `const T'. Then, T should be `volatile int'. */
16430 arg = cp_build_qualified_type_real
16431 (arg, cp_type_quals (arg) & ~cp_type_quals (parm), tf_none);
16432 if (arg == error_mark_node)
16433 return unify_invalid (explain_p);
16435 /* Simple cases: Value already set, does match or doesn't. */
16436 if (targ != NULL_TREE && same_type_p (targ, arg))
16437 return unify_success (explain_p);
16439 return unify_inconsistency (explain_p, parm, targ, arg);
16441 /* Make sure that ARG is not a variable-sized array. (Note
16442 that were talking about variable-sized arrays (like
16443 `int[n]'), rather than arrays of unknown size (like
16444 `int[]').) We'll get very confused by such a type since
16445 the bound of the array is not constant, and therefore
16446 not mangleable. Besides, such types are not allowed in
16447 ISO C++, so we can do as we please here. We do allow
16448 them for 'auto' deduction, since that isn't ABI-exposed. */
16449 if (!is_auto (parm) && variably_modified_type_p (arg, NULL_TREE))
16450 return unify_vla_arg (explain_p, arg);
16452 /* Strip typedefs as in convert_template_argument. */
16453 arg = canonicalize_type_argument (arg, tf_none);
16456 /* If ARG is a parameter pack or an expansion, we cannot unify
16457 against it unless PARM is also a parameter pack. */
16458 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
16459 && !template_parameter_pack_p (parm))
16460 return unify_parameter_pack_mismatch (explain_p, parm, arg);
16462 /* If the argument deduction results is a METHOD_TYPE,
16463 then there is a problem.
16464 METHOD_TYPE doesn't map to any real C++ type the result of
16465 the deduction can not be of that type. */
16466 if (TREE_CODE (arg) == METHOD_TYPE)
16467 return unify_method_type_error (explain_p, arg);
16469 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
16470 return unify_success (explain_p);
16472 case TEMPLATE_PARM_INDEX:
16473 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
16474 if (tparm == error_mark_node)
16475 return unify_invalid (explain_p);
16477 if (TEMPLATE_PARM_LEVEL (parm)
16478 != template_decl_level (tparm))
16480 /* The PARM is not one we're trying to unify. Just check
16481 to see if it matches ARG. */
16482 int result = !(TREE_CODE (arg) == TREE_CODE (parm)
16483 && cp_tree_equal (parm, arg));
16485 unify_expression_unequal (explain_p, parm, arg);
16489 idx = TEMPLATE_PARM_IDX (parm);
16490 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
16494 int x = !cp_tree_equal (targ, arg);
16496 unify_inconsistency (explain_p, parm, targ, arg);
16500 /* [temp.deduct.type] If, in the declaration of a function template
16501 with a non-type template-parameter, the non-type
16502 template-parameter is used in an expression in the function
16503 parameter-list and, if the corresponding template-argument is
16504 deduced, the template-argument type shall match the type of the
16505 template-parameter exactly, except that a template-argument
16506 deduced from an array bound may be of any integral type.
16507 The non-type parameter might use already deduced type parameters. */
16508 tparm = tsubst (TREE_TYPE (parm), targs, 0, NULL_TREE);
16509 if (!TREE_TYPE (arg))
16510 /* Template-parameter dependent expression. Just accept it for now.
16511 It will later be processed in convert_template_argument. */
16513 else if (same_type_p (TREE_TYPE (arg), tparm))
16515 else if ((strict & UNIFY_ALLOW_INTEGER)
16516 && (TREE_CODE (tparm) == INTEGER_TYPE
16517 || TREE_CODE (tparm) == BOOLEAN_TYPE))
16518 /* Convert the ARG to the type of PARM; the deduced non-type
16519 template argument must exactly match the types of the
16520 corresponding parameter. */
16521 arg = fold (build_nop (tparm, arg));
16522 else if (uses_template_parms (tparm))
16523 /* We haven't deduced the type of this parameter yet. Try again
16525 return unify_success (explain_p);
16527 return unify_type_mismatch (explain_p, tparm, arg);
16529 /* If ARG is a parameter pack or an expansion, we cannot unify
16530 against it unless PARM is also a parameter pack. */
16531 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
16532 && !TEMPLATE_PARM_PARAMETER_PACK (parm))
16533 return unify_parameter_pack_mismatch (explain_p, parm, arg);
16535 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
16536 return unify_success (explain_p);
16540 /* A pointer-to-member constant can be unified only with
16541 another constant. */
16542 if (TREE_CODE (arg) != PTRMEM_CST)
16543 return unify_ptrmem_cst_mismatch (explain_p, parm, arg);
16545 /* Just unify the class member. It would be useless (and possibly
16546 wrong, depending on the strict flags) to unify also
16547 PTRMEM_CST_CLASS, because we want to be sure that both parm and
16548 arg refer to the same variable, even if through different
16549 classes. For instance:
16551 struct A { int x; };
16554 Unification of &A::x and &B::x must succeed. */
16555 return unify (tparms, targs, PTRMEM_CST_MEMBER (parm),
16556 PTRMEM_CST_MEMBER (arg), strict, explain_p);
16561 if (TREE_CODE (arg) != POINTER_TYPE)
16562 return unify_type_mismatch (explain_p, parm, arg);
16564 /* [temp.deduct.call]
16566 A can be another pointer or pointer to member type that can
16567 be converted to the deduced A via a qualification
16568 conversion (_conv.qual_).
16570 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
16571 This will allow for additional cv-qualification of the
16572 pointed-to types if appropriate. */
16574 if (TREE_CODE (TREE_TYPE (arg)) == RECORD_TYPE)
16575 /* The derived-to-base conversion only persists through one
16576 level of pointers. */
16577 strict |= (strict_in & UNIFY_ALLOW_DERIVED);
16579 return unify (tparms, targs, TREE_TYPE (parm),
16580 TREE_TYPE (arg), strict, explain_p);
16583 case REFERENCE_TYPE:
16584 if (TREE_CODE (arg) != REFERENCE_TYPE)
16585 return unify_type_mismatch (explain_p, parm, arg);
16586 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
16587 strict & UNIFY_ALLOW_MORE_CV_QUAL, explain_p);
16590 if (TREE_CODE (arg) != ARRAY_TYPE)
16591 return unify_type_mismatch (explain_p, parm, arg);
16592 if ((TYPE_DOMAIN (parm) == NULL_TREE)
16593 != (TYPE_DOMAIN (arg) == NULL_TREE))
16594 return unify_type_mismatch (explain_p, parm, arg);
16595 if (TYPE_DOMAIN (parm) != NULL_TREE)
16602 /* Our representation of array types uses "N - 1" as the
16603 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
16604 not an integer constant. We cannot unify arbitrarily
16605 complex expressions, so we eliminate the MINUS_EXPRs
16607 parm_max = TYPE_MAX_VALUE (TYPE_DOMAIN (parm));
16608 parm_cst = TREE_CODE (parm_max) == INTEGER_CST;
16611 gcc_assert (TREE_CODE (parm_max) == MINUS_EXPR);
16612 parm_max = TREE_OPERAND (parm_max, 0);
16614 arg_max = TYPE_MAX_VALUE (TYPE_DOMAIN (arg));
16615 arg_cst = TREE_CODE (arg_max) == INTEGER_CST;
16618 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
16619 trying to unify the type of a variable with the type
16620 of a template parameter. For example:
16622 template <unsigned int N>
16623 void f (char (&) [N]);
16630 Here, the type of the ARG will be "int [g(i)]", and
16631 may be a SAVE_EXPR, etc. */
16632 if (TREE_CODE (arg_max) != MINUS_EXPR)
16633 return unify_vla_arg (explain_p, arg);
16634 arg_max = TREE_OPERAND (arg_max, 0);
16637 /* If only one of the bounds used a MINUS_EXPR, compensate
16638 by adding one to the other bound. */
16639 if (parm_cst && !arg_cst)
16640 parm_max = fold_build2_loc (input_location, PLUS_EXPR,
16644 else if (arg_cst && !parm_cst)
16645 arg_max = fold_build2_loc (input_location, PLUS_EXPR,
16650 RECUR_AND_CHECK_FAILURE (tparms, targs, parm_max, arg_max,
16651 UNIFY_ALLOW_INTEGER, explain_p);
16653 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
16654 strict & UNIFY_ALLOW_MORE_CV_QUAL, explain_p);
16661 case ENUMERAL_TYPE:
16664 if (TREE_CODE (arg) != TREE_CODE (parm))
16665 return unify_type_mismatch (explain_p, parm, arg);
16667 /* We have already checked cv-qualification at the top of the
16669 if (!same_type_ignoring_top_level_qualifiers_p (arg, parm))
16670 return unify_type_mismatch (explain_p, parm, arg);
16672 /* As far as unification is concerned, this wins. Later checks
16673 will invalidate it if necessary. */
16674 return unify_success (explain_p);
16676 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
16677 /* Type INTEGER_CST can come from ordinary constant template args. */
16679 while (TREE_CODE (arg) == NOP_EXPR)
16680 arg = TREE_OPERAND (arg, 0);
16682 if (TREE_CODE (arg) != INTEGER_CST)
16683 return unify_template_argument_mismatch (explain_p, parm, arg);
16684 return (tree_int_cst_equal (parm, arg)
16685 ? unify_success (explain_p)
16686 : unify_template_argument_mismatch (explain_p, parm, arg));
16690 int i, len, argslen;
16691 int parm_variadic_p = 0;
16693 if (TREE_CODE (arg) != TREE_VEC)
16694 return unify_template_argument_mismatch (explain_p, parm, arg);
16696 len = TREE_VEC_LENGTH (parm);
16697 argslen = TREE_VEC_LENGTH (arg);
16699 /* Check for pack expansions in the parameters. */
16700 for (i = 0; i < len; ++i)
16702 if (PACK_EXPANSION_P (TREE_VEC_ELT (parm, i)))
16705 /* We can unify against something with a trailing
16707 parm_variadic_p = 1;
16709 /* [temp.deduct.type]/9: If the template argument list of
16710 P contains a pack expansion that is not the last
16711 template argument, the entire template argument list
16712 is a non-deduced context. */
16713 return unify_success (explain_p);
16717 /* If we don't have enough arguments to satisfy the parameters
16718 (not counting the pack expression at the end), or we have
16719 too many arguments for a parameter list that doesn't end in
16720 a pack expression, we can't unify. */
16721 if (parm_variadic_p
16722 ? argslen < len - parm_variadic_p
16724 return unify_arity (explain_p, TREE_VEC_LENGTH (arg), len);
16726 /* Unify all of the parameters that precede the (optional)
16727 pack expression. */
16728 for (i = 0; i < len - parm_variadic_p; ++i)
16730 RECUR_AND_CHECK_FAILURE (tparms, targs,
16731 TREE_VEC_ELT (parm, i),
16732 TREE_VEC_ELT (arg, i),
16733 UNIFY_ALLOW_NONE, explain_p);
16735 if (parm_variadic_p)
16736 return unify_pack_expansion (tparms, targs, parm, arg,
16738 /*subr=*/true, explain_p);
16739 return unify_success (explain_p);
16744 if (TREE_CODE (arg) != TREE_CODE (parm))
16745 return unify_type_mismatch (explain_p, parm, arg);
16747 if (TYPE_PTRMEMFUNC_P (parm))
16749 if (!TYPE_PTRMEMFUNC_P (arg))
16750 return unify_type_mismatch (explain_p, parm, arg);
16752 return unify (tparms, targs,
16753 TYPE_PTRMEMFUNC_FN_TYPE (parm),
16754 TYPE_PTRMEMFUNC_FN_TYPE (arg),
16755 strict, explain_p);
16758 if (CLASSTYPE_TEMPLATE_INFO (parm))
16760 tree t = NULL_TREE;
16762 if (strict_in & UNIFY_ALLOW_DERIVED)
16764 /* First, we try to unify the PARM and ARG directly. */
16765 t = try_class_unification (tparms, targs,
16766 parm, arg, explain_p);
16770 /* Fallback to the special case allowed in
16771 [temp.deduct.call]:
16773 If P is a class, and P has the form
16774 template-id, then A can be a derived class of
16775 the deduced A. Likewise, if P is a pointer to
16776 a class of the form template-id, A can be a
16777 pointer to a derived class pointed to by the
16779 enum template_base_result r;
16780 r = get_template_base (tparms, targs, parm, arg,
16784 return unify_no_common_base (explain_p, r, parm, arg);
16787 else if (CLASSTYPE_TEMPLATE_INFO (arg)
16788 && (CLASSTYPE_TI_TEMPLATE (parm)
16789 == CLASSTYPE_TI_TEMPLATE (arg)))
16790 /* Perhaps PARM is something like S<U> and ARG is S<int>.
16791 Then, we should unify `int' and `U'. */
16794 /* There's no chance of unification succeeding. */
16795 return unify_type_mismatch (explain_p, parm, arg);
16797 return unify (tparms, targs, CLASSTYPE_TI_ARGS (parm),
16798 CLASSTYPE_TI_ARGS (t), UNIFY_ALLOW_NONE, explain_p);
16800 else if (!same_type_ignoring_top_level_qualifiers_p (parm, arg))
16801 return unify_type_mismatch (explain_p, parm, arg);
16802 return unify_success (explain_p);
16805 case FUNCTION_TYPE:
16807 unsigned int nargs;
16812 if (TREE_CODE (arg) != TREE_CODE (parm))
16813 return unify_type_mismatch (explain_p, parm, arg);
16815 /* CV qualifications for methods can never be deduced, they must
16816 match exactly. We need to check them explicitly here,
16817 because type_unification_real treats them as any other
16818 cv-qualified parameter. */
16819 if (TREE_CODE (parm) == METHOD_TYPE
16820 && (!check_cv_quals_for_unify
16822 class_of_this_parm (arg),
16823 class_of_this_parm (parm))))
16824 return unify_cv_qual_mismatch (explain_p, parm, arg);
16826 RECUR_AND_CHECK_FAILURE (tparms, targs, TREE_TYPE (parm),
16827 TREE_TYPE (arg), UNIFY_ALLOW_NONE, explain_p);
16829 nargs = list_length (TYPE_ARG_TYPES (arg));
16830 args = XALLOCAVEC (tree, nargs);
16831 for (a = TYPE_ARG_TYPES (arg), i = 0;
16832 a != NULL_TREE && a != void_list_node;
16833 a = TREE_CHAIN (a), ++i)
16834 args[i] = TREE_VALUE (a);
16837 return type_unification_real (tparms, targs, TYPE_ARG_TYPES (parm),
16838 args, nargs, 1, DEDUCE_EXACT,
16839 LOOKUP_NORMAL, explain_p);
16843 /* Unify a pointer to member with a pointer to member function, which
16844 deduces the type of the member as a function type. */
16845 if (TYPE_PTRMEMFUNC_P (arg))
16850 /* Check top-level cv qualifiers */
16851 if (!check_cv_quals_for_unify (UNIFY_ALLOW_NONE, arg, parm))
16852 return unify_cv_qual_mismatch (explain_p, parm, arg);
16854 RECUR_AND_CHECK_FAILURE (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
16855 TYPE_PTRMEMFUNC_OBJECT_TYPE (arg),
16856 UNIFY_ALLOW_NONE, explain_p);
16858 /* Determine the type of the function we are unifying against. */
16859 method_type = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (arg));
16861 build_function_type (TREE_TYPE (method_type),
16862 TREE_CHAIN (TYPE_ARG_TYPES (method_type)));
16864 /* Extract the cv-qualifiers of the member function from the
16865 implicit object parameter and place them on the function
16866 type to be restored later. */
16867 fntype = apply_memfn_quals (fntype, type_memfn_quals (method_type));
16868 return unify (tparms, targs, TREE_TYPE (parm), fntype, strict, explain_p);
16871 if (TREE_CODE (arg) != OFFSET_TYPE)
16872 return unify_type_mismatch (explain_p, parm, arg);
16873 RECUR_AND_CHECK_FAILURE (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
16874 TYPE_OFFSET_BASETYPE (arg),
16875 UNIFY_ALLOW_NONE, explain_p);
16876 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
16877 strict, explain_p);
16880 if (DECL_TEMPLATE_PARM_P (parm))
16881 return unify (tparms, targs, DECL_INITIAL (parm), arg, strict, explain_p);
16882 if (arg != integral_constant_value (parm))
16883 return unify_template_argument_mismatch (explain_p, parm, arg);
16884 return unify_success (explain_p);
16887 case TEMPLATE_DECL:
16888 /* Matched cases are handled by the ARG == PARM test above. */
16889 return unify_template_argument_mismatch (explain_p, parm, arg);
16892 /* A non-type template parameter that is a variable should be a
16893 an integral constant, in which case, it whould have been
16894 folded into its (constant) value. So we should not be getting
16895 a variable here. */
16896 gcc_unreachable ();
16898 case TYPE_ARGUMENT_PACK:
16899 case NONTYPE_ARGUMENT_PACK:
16900 return unify (tparms, targs, ARGUMENT_PACK_ARGS (parm),
16901 ARGUMENT_PACK_ARGS (arg), strict, explain_p);
16904 case DECLTYPE_TYPE:
16905 case UNDERLYING_TYPE:
16906 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
16907 or UNDERLYING_TYPE nodes. */
16908 return unify_success (explain_p);
16911 /* Unification fails if we hit an error node. */
16912 return unify_invalid (explain_p);
16915 /* An unresolved overload is a nondeduced context. */
16916 if (is_overloaded_fn (parm) || type_unknown_p (parm))
16917 return unify_success (explain_p);
16918 gcc_assert (EXPR_P (parm));
16920 /* We must be looking at an expression. This can happen with
16924 void foo(S<I>, S<I + 2>);
16926 This is a "nondeduced context":
16930 The nondeduced contexts are:
16932 --A type that is a template-id in which one or more of
16933 the template-arguments is an expression that references
16934 a template-parameter.
16936 In these cases, we assume deduction succeeded, but don't
16937 actually infer any unifications. */
16939 if (!uses_template_parms (parm)
16940 && !template_args_equal (parm, arg))
16941 return unify_expression_unequal (explain_p, parm, arg);
16943 return unify_success (explain_p);
16946 #undef RECUR_AND_CHECK_FAILURE
16948 /* Note that DECL can be defined in this translation unit, if
16952 mark_definable (tree decl)
16955 DECL_NOT_REALLY_EXTERN (decl) = 1;
16956 FOR_EACH_CLONE (clone, decl)
16957 DECL_NOT_REALLY_EXTERN (clone) = 1;
16960 /* Called if RESULT is explicitly instantiated, or is a member of an
16961 explicitly instantiated class. */
16964 mark_decl_instantiated (tree result, int extern_p)
16966 SET_DECL_EXPLICIT_INSTANTIATION (result);
16968 /* If this entity has already been written out, it's too late to
16969 make any modifications. */
16970 if (TREE_ASM_WRITTEN (result))
16973 if (TREE_CODE (result) != FUNCTION_DECL)
16974 /* The TREE_PUBLIC flag for function declarations will have been
16975 set correctly by tsubst. */
16976 TREE_PUBLIC (result) = 1;
16978 /* This might have been set by an earlier implicit instantiation. */
16979 DECL_COMDAT (result) = 0;
16982 DECL_NOT_REALLY_EXTERN (result) = 0;
16985 mark_definable (result);
16986 /* Always make artificials weak. */
16987 if (DECL_ARTIFICIAL (result) && flag_weak)
16988 comdat_linkage (result);
16989 /* For WIN32 we also want to put explicit instantiations in
16990 linkonce sections. */
16991 else if (TREE_PUBLIC (result))
16992 maybe_make_one_only (result);
16995 /* If EXTERN_P, then this function will not be emitted -- unless
16996 followed by an explicit instantiation, at which point its linkage
16997 will be adjusted. If !EXTERN_P, then this function will be
16998 emitted here. In neither circumstance do we want
16999 import_export_decl to adjust the linkage. */
17000 DECL_INTERFACE_KNOWN (result) = 1;
17003 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
17004 important template arguments. If any are missing, we check whether
17005 they're important by using error_mark_node for substituting into any
17006 args that were used for partial ordering (the ones between ARGS and END)
17007 and seeing if it bubbles up. */
17010 check_undeduced_parms (tree targs, tree args, tree end)
17012 bool found = false;
17014 for (i = TREE_VEC_LENGTH (targs) - 1; i >= 0; --i)
17015 if (TREE_VEC_ELT (targs, i) == NULL_TREE)
17018 TREE_VEC_ELT (targs, i) = error_mark_node;
17022 for (; args != end; args = TREE_CHAIN (args))
17024 tree substed = tsubst (TREE_VALUE (args), targs, tf_none, NULL_TREE);
17025 if (substed == error_mark_node)
17032 /* Given two function templates PAT1 and PAT2, return:
17034 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
17035 -1 if PAT2 is more specialized than PAT1.
17036 0 if neither is more specialized.
17038 LEN indicates the number of parameters we should consider
17039 (defaulted parameters should not be considered).
17041 The 1998 std underspecified function template partial ordering, and
17042 DR214 addresses the issue. We take pairs of arguments, one from
17043 each of the templates, and deduce them against each other. One of
17044 the templates will be more specialized if all the *other*
17045 template's arguments deduce against its arguments and at least one
17046 of its arguments *does* *not* deduce against the other template's
17047 corresponding argument. Deduction is done as for class templates.
17048 The arguments used in deduction have reference and top level cv
17049 qualifiers removed. Iff both arguments were originally reference
17050 types *and* deduction succeeds in both directions, the template
17051 with the more cv-qualified argument wins for that pairing (if
17052 neither is more cv-qualified, they both are equal). Unlike regular
17053 deduction, after all the arguments have been deduced in this way,
17054 we do *not* verify the deduced template argument values can be
17055 substituted into non-deduced contexts.
17057 The logic can be a bit confusing here, because we look at deduce1 and
17058 targs1 to see if pat2 is at least as specialized, and vice versa; if we
17059 can find template arguments for pat1 to make arg1 look like arg2, that
17060 means that arg2 is at least as specialized as arg1. */
17063 more_specialized_fn (tree pat1, tree pat2, int len)
17065 tree decl1 = DECL_TEMPLATE_RESULT (pat1);
17066 tree decl2 = DECL_TEMPLATE_RESULT (pat2);
17067 tree targs1 = make_tree_vec (DECL_NTPARMS (pat1));
17068 tree targs2 = make_tree_vec (DECL_NTPARMS (pat2));
17069 tree tparms1 = DECL_INNERMOST_TEMPLATE_PARMS (pat1);
17070 tree tparms2 = DECL_INNERMOST_TEMPLATE_PARMS (pat2);
17071 tree args1 = TYPE_ARG_TYPES (TREE_TYPE (decl1));
17072 tree args2 = TYPE_ARG_TYPES (TREE_TYPE (decl2));
17073 tree origs1, origs2;
17074 bool lose1 = false;
17075 bool lose2 = false;
17077 /* Remove the this parameter from non-static member functions. If
17078 one is a non-static member function and the other is not a static
17079 member function, remove the first parameter from that function
17080 also. This situation occurs for operator functions where we
17081 locate both a member function (with this pointer) and non-member
17082 operator (with explicit first operand). */
17083 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl1))
17085 len--; /* LEN is the number of significant arguments for DECL1 */
17086 args1 = TREE_CHAIN (args1);
17087 if (!DECL_STATIC_FUNCTION_P (decl2))
17088 args2 = TREE_CHAIN (args2);
17090 else if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl2))
17092 args2 = TREE_CHAIN (args2);
17093 if (!DECL_STATIC_FUNCTION_P (decl1))
17096 args1 = TREE_CHAIN (args1);
17100 /* If only one is a conversion operator, they are unordered. */
17101 if (DECL_CONV_FN_P (decl1) != DECL_CONV_FN_P (decl2))
17104 /* Consider the return type for a conversion function */
17105 if (DECL_CONV_FN_P (decl1))
17107 args1 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl1)), args1);
17108 args2 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl2)), args2);
17112 processing_template_decl++;
17118 /* Stop when an ellipsis is seen. */
17119 && args1 != NULL_TREE && args2 != NULL_TREE)
17121 tree arg1 = TREE_VALUE (args1);
17122 tree arg2 = TREE_VALUE (args2);
17123 int deduce1, deduce2;
17127 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
17128 && TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
17130 /* When both arguments are pack expansions, we need only
17131 unify the patterns themselves. */
17132 arg1 = PACK_EXPANSION_PATTERN (arg1);
17133 arg2 = PACK_EXPANSION_PATTERN (arg2);
17135 /* This is the last comparison we need to do. */
17139 if (TREE_CODE (arg1) == REFERENCE_TYPE)
17141 arg1 = TREE_TYPE (arg1);
17142 quals1 = cp_type_quals (arg1);
17145 if (TREE_CODE (arg2) == REFERENCE_TYPE)
17147 arg2 = TREE_TYPE (arg2);
17148 quals2 = cp_type_quals (arg2);
17151 if ((quals1 < 0) != (quals2 < 0))
17153 /* Only of the args is a reference, see if we should apply
17154 array/function pointer decay to it. This is not part of
17155 DR214, but is, IMHO, consistent with the deduction rules
17156 for the function call itself, and with our earlier
17157 implementation of the underspecified partial ordering
17158 rules. (nathan). */
17161 switch (TREE_CODE (arg1))
17164 arg1 = TREE_TYPE (arg1);
17166 case FUNCTION_TYPE:
17167 arg1 = build_pointer_type (arg1);
17176 switch (TREE_CODE (arg2))
17179 arg2 = TREE_TYPE (arg2);
17181 case FUNCTION_TYPE:
17182 arg2 = build_pointer_type (arg2);
17191 arg1 = TYPE_MAIN_VARIANT (arg1);
17192 arg2 = TYPE_MAIN_VARIANT (arg2);
17194 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION)
17196 int i, len2 = list_length (args2);
17197 tree parmvec = make_tree_vec (1);
17198 tree argvec = make_tree_vec (len2);
17201 /* Setup the parameter vector, which contains only ARG1. */
17202 TREE_VEC_ELT (parmvec, 0) = arg1;
17204 /* Setup the argument vector, which contains the remaining
17206 for (i = 0; i < len2; i++, ta = TREE_CHAIN (ta))
17207 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
17209 deduce1 = (unify_pack_expansion (tparms1, targs1, parmvec,
17210 argvec, DEDUCE_EXACT,
17211 /*subr=*/true, /*explain_p=*/false)
17214 /* We cannot deduce in the other direction, because ARG1 is
17215 a pack expansion but ARG2 is not. */
17218 else if (TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
17220 int i, len1 = list_length (args1);
17221 tree parmvec = make_tree_vec (1);
17222 tree argvec = make_tree_vec (len1);
17225 /* Setup the parameter vector, which contains only ARG1. */
17226 TREE_VEC_ELT (parmvec, 0) = arg2;
17228 /* Setup the argument vector, which contains the remaining
17230 for (i = 0; i < len1; i++, ta = TREE_CHAIN (ta))
17231 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
17233 deduce2 = (unify_pack_expansion (tparms2, targs2, parmvec,
17234 argvec, DEDUCE_EXACT,
17235 /*subr=*/true, /*explain_p=*/false)
17238 /* We cannot deduce in the other direction, because ARG2 is
17239 a pack expansion but ARG1 is not.*/
17245 /* The normal case, where neither argument is a pack
17247 deduce1 = (unify (tparms1, targs1, arg1, arg2,
17248 UNIFY_ALLOW_NONE, /*explain_p=*/false)
17250 deduce2 = (unify (tparms2, targs2, arg2, arg1,
17251 UNIFY_ALLOW_NONE, /*explain_p=*/false)
17255 /* If we couldn't deduce arguments for tparms1 to make arg1 match
17256 arg2, then arg2 is not as specialized as arg1. */
17262 /* "If, for a given type, deduction succeeds in both directions
17263 (i.e., the types are identical after the transformations above)
17264 and if the type from the argument template is more cv-qualified
17265 than the type from the parameter template (as described above)
17266 that type is considered to be more specialized than the other. If
17267 neither type is more cv-qualified than the other then neither type
17268 is more specialized than the other." */
17270 if (deduce1 && deduce2
17271 && quals1 != quals2 && quals1 >= 0 && quals2 >= 0)
17273 if ((quals1 & quals2) == quals2)
17275 if ((quals1 & quals2) == quals1)
17279 if (lose1 && lose2)
17280 /* We've failed to deduce something in either direction.
17281 These must be unordered. */
17284 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
17285 || TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
17286 /* We have already processed all of the arguments in our
17287 handing of the pack expansion type. */
17290 args1 = TREE_CHAIN (args1);
17291 args2 = TREE_CHAIN (args2);
17294 /* "In most cases, all template parameters must have values in order for
17295 deduction to succeed, but for partial ordering purposes a template
17296 parameter may remain without a value provided it is not used in the
17297 types being used for partial ordering."
17299 Thus, if we are missing any of the targs1 we need to substitute into
17300 origs1, then pat2 is not as specialized as pat1. This can happen when
17301 there is a nondeduced context. */
17302 if (!lose2 && check_undeduced_parms (targs1, origs1, args1))
17304 if (!lose1 && check_undeduced_parms (targs2, origs2, args2))
17307 processing_template_decl--;
17309 /* All things being equal, if the next argument is a pack expansion
17310 for one function but not for the other, prefer the
17311 non-variadic function. FIXME this is bogus; see c++/41958. */
17313 && args1 && TREE_VALUE (args1)
17314 && args2 && TREE_VALUE (args2))
17316 lose1 = TREE_CODE (TREE_VALUE (args1)) == TYPE_PACK_EXPANSION;
17317 lose2 = TREE_CODE (TREE_VALUE (args2)) == TYPE_PACK_EXPANSION;
17320 if (lose1 == lose2)
17328 /* Determine which of two partial specializations is more specialized.
17330 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
17331 to the first partial specialization. The TREE_VALUE is the
17332 innermost set of template parameters for the partial
17333 specialization. PAT2 is similar, but for the second template.
17335 Return 1 if the first partial specialization is more specialized;
17336 -1 if the second is more specialized; 0 if neither is more
17339 See [temp.class.order] for information about determining which of
17340 two templates is more specialized. */
17343 more_specialized_class (tree pat1, tree pat2)
17348 bool any_deductions = false;
17350 tmpl1 = TREE_TYPE (pat1);
17351 tmpl2 = TREE_TYPE (pat2);
17353 /* Just like what happens for functions, if we are ordering between
17354 different class template specializations, we may encounter dependent
17355 types in the arguments, and we need our dependency check functions
17356 to behave correctly. */
17357 ++processing_template_decl;
17358 targs = get_class_bindings (TREE_VALUE (pat1),
17359 CLASSTYPE_TI_ARGS (tmpl1),
17360 CLASSTYPE_TI_ARGS (tmpl2));
17364 any_deductions = true;
17367 targs = get_class_bindings (TREE_VALUE (pat2),
17368 CLASSTYPE_TI_ARGS (tmpl2),
17369 CLASSTYPE_TI_ARGS (tmpl1));
17373 any_deductions = true;
17375 --processing_template_decl;
17377 /* In the case of a tie where at least one of the class templates
17378 has a parameter pack at the end, the template with the most
17379 non-packed parameters wins. */
17382 && (template_args_variadic_p (TREE_PURPOSE (pat1))
17383 || template_args_variadic_p (TREE_PURPOSE (pat2))))
17385 tree args1 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat1));
17386 tree args2 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat2));
17387 int len1 = TREE_VEC_LENGTH (args1);
17388 int len2 = TREE_VEC_LENGTH (args2);
17390 /* We don't count the pack expansion at the end. */
17391 if (template_args_variadic_p (TREE_PURPOSE (pat1)))
17393 if (template_args_variadic_p (TREE_PURPOSE (pat2)))
17398 else if (len1 < len2)
17405 /* Return the template arguments that will produce the function signature
17406 DECL from the function template FN, with the explicit template
17407 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
17408 also match. Return NULL_TREE if no satisfactory arguments could be
17412 get_bindings (tree fn, tree decl, tree explicit_args, bool check_rettype)
17414 int ntparms = DECL_NTPARMS (fn);
17415 tree targs = make_tree_vec (ntparms);
17417 tree decl_arg_types;
17419 unsigned int nargs, ix;
17422 /* Substitute the explicit template arguments into the type of DECL.
17423 The call to fn_type_unification will handle substitution into the
17425 decl_type = TREE_TYPE (decl);
17426 if (explicit_args && uses_template_parms (decl_type))
17429 tree converted_args;
17431 if (DECL_TEMPLATE_INFO (decl))
17432 tmpl = DECL_TI_TEMPLATE (decl);
17434 /* We can get here for some invalid specializations. */
17438 = coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
17439 explicit_args, NULL_TREE,
17441 /*require_all_args=*/false,
17442 /*use_default_args=*/false);
17443 if (converted_args == error_mark_node)
17446 decl_type = tsubst (decl_type, converted_args, tf_none, NULL_TREE);
17447 if (decl_type == error_mark_node)
17451 /* Never do unification on the 'this' parameter. */
17452 decl_arg_types = skip_artificial_parms_for (decl,
17453 TYPE_ARG_TYPES (decl_type));
17455 nargs = list_length (decl_arg_types);
17456 args = XALLOCAVEC (tree, nargs);
17457 for (arg = decl_arg_types, ix = 0;
17458 arg != NULL_TREE && arg != void_list_node;
17459 arg = TREE_CHAIN (arg), ++ix)
17460 args[ix] = TREE_VALUE (arg);
17462 if (fn_type_unification (fn, explicit_args, targs,
17464 (check_rettype || DECL_CONV_FN_P (fn)
17465 ? TREE_TYPE (decl_type) : NULL_TREE),
17466 DEDUCE_EXACT, LOOKUP_NORMAL, /*explain_p=*/false))
17472 /* Return the innermost template arguments that, when applied to a
17473 template specialization whose innermost template parameters are
17474 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
17477 For example, suppose we have:
17479 template <class T, class U> struct S {};
17480 template <class T> struct S<T*, int> {};
17482 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
17483 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
17484 int}. The resulting vector will be {double}, indicating that `T'
17485 is bound to `double'. */
17488 get_class_bindings (tree tparms, tree spec_args, tree args)
17490 int i, ntparms = TREE_VEC_LENGTH (tparms);
17492 tree innermost_deduced_args;
17494 innermost_deduced_args = make_tree_vec (ntparms);
17495 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
17497 deduced_args = copy_node (args);
17498 SET_TMPL_ARGS_LEVEL (deduced_args,
17499 TMPL_ARGS_DEPTH (deduced_args),
17500 innermost_deduced_args);
17503 deduced_args = innermost_deduced_args;
17505 if (unify (tparms, deduced_args,
17506 INNERMOST_TEMPLATE_ARGS (spec_args),
17507 INNERMOST_TEMPLATE_ARGS (args),
17508 UNIFY_ALLOW_NONE, /*explain_p=*/false))
17511 for (i = 0; i < ntparms; ++i)
17512 if (! TREE_VEC_ELT (innermost_deduced_args, i))
17515 /* Verify that nondeduced template arguments agree with the type
17516 obtained from argument deduction.
17520 struct A { typedef int X; };
17521 template <class T, class U> struct C {};
17522 template <class T> struct C<T, typename T::X> {};
17524 Then with the instantiation `C<A, int>', we can deduce that
17525 `T' is `A' but unify () does not check whether `typename T::X'
17527 spec_args = tsubst (spec_args, deduced_args, tf_none, NULL_TREE);
17528 if (spec_args == error_mark_node
17529 /* We only need to check the innermost arguments; the other
17530 arguments will always agree. */
17531 || !comp_template_args (INNERMOST_TEMPLATE_ARGS (spec_args),
17532 INNERMOST_TEMPLATE_ARGS (args)))
17535 /* Now that we have bindings for all of the template arguments,
17536 ensure that the arguments deduced for the template template
17537 parameters have compatible template parameter lists. See the use
17538 of template_template_parm_bindings_ok_p in fn_type_unification
17539 for more information. */
17540 if (!template_template_parm_bindings_ok_p (tparms, deduced_args))
17543 return deduced_args;
17546 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
17547 Return the TREE_LIST node with the most specialized template, if
17548 any. If there is no most specialized template, the error_mark_node
17551 Note that this function does not look at, or modify, the
17552 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
17553 returned is one of the elements of INSTANTIATIONS, callers may
17554 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
17555 and retrieve it from the value returned. */
17558 most_specialized_instantiation (tree templates)
17562 ++processing_template_decl;
17565 for (fn = TREE_CHAIN (templates); fn; fn = TREE_CHAIN (fn))
17569 if (get_bindings (TREE_VALUE (champ),
17570 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
17571 NULL_TREE, /*check_ret=*/true))
17574 if (get_bindings (TREE_VALUE (fn),
17575 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
17576 NULL_TREE, /*check_ret=*/true))
17583 /* Equally specialized, move to next function. If there
17584 is no next function, nothing's most specialized. */
17585 fn = TREE_CHAIN (fn);
17593 /* Now verify that champ is better than everything earlier in the
17594 instantiation list. */
17595 for (fn = templates; fn != champ; fn = TREE_CHAIN (fn))
17596 if (get_bindings (TREE_VALUE (champ),
17597 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
17598 NULL_TREE, /*check_ret=*/true)
17599 || !get_bindings (TREE_VALUE (fn),
17600 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
17601 NULL_TREE, /*check_ret=*/true))
17607 processing_template_decl--;
17610 return error_mark_node;
17615 /* If DECL is a specialization of some template, return the most
17616 general such template. Otherwise, returns NULL_TREE.
17618 For example, given:
17620 template <class T> struct S { template <class U> void f(U); };
17622 if TMPL is `template <class U> void S<int>::f(U)' this will return
17623 the full template. This function will not trace past partial
17624 specializations, however. For example, given in addition:
17626 template <class T> struct S<T*> { template <class U> void f(U); };
17628 if TMPL is `template <class U> void S<int*>::f(U)' this will return
17629 `template <class T> template <class U> S<T*>::f(U)'. */
17632 most_general_template (tree decl)
17634 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
17635 an immediate specialization. */
17636 if (TREE_CODE (decl) == FUNCTION_DECL)
17638 if (DECL_TEMPLATE_INFO (decl)) {
17639 decl = DECL_TI_TEMPLATE (decl);
17641 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
17642 template friend. */
17643 if (TREE_CODE (decl) != TEMPLATE_DECL)
17649 /* Look for more and more general templates. */
17650 while (DECL_TEMPLATE_INFO (decl))
17652 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
17653 (See cp-tree.h for details.) */
17654 if (TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
17657 if (CLASS_TYPE_P (TREE_TYPE (decl))
17658 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)))
17661 /* Stop if we run into an explicitly specialized class template. */
17662 if (!DECL_NAMESPACE_SCOPE_P (decl)
17663 && DECL_CONTEXT (decl)
17664 && CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (decl)))
17667 decl = DECL_TI_TEMPLATE (decl);
17673 /* Return the most specialized of the class template partial
17674 specializations of TMPL which can produce TYPE, a specialization of
17675 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
17676 a _TYPE node corresponding to the partial specialization, while the
17677 TREE_PURPOSE is the set of template arguments that must be
17678 substituted into the TREE_TYPE in order to generate TYPE.
17680 If the choice of partial specialization is ambiguous, a diagnostic
17681 is issued, and the error_mark_node is returned. If there are no
17682 partial specializations of TMPL matching TYPE, then NULL_TREE is
17686 most_specialized_class (tree type, tree tmpl, tsubst_flags_t complain)
17688 tree list = NULL_TREE;
17694 tree outer_args = NULL_TREE;
17696 tmpl = most_general_template (tmpl);
17697 args = CLASSTYPE_TI_ARGS (type);
17699 /* For determining which partial specialization to use, only the
17700 innermost args are interesting. */
17701 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
17703 outer_args = strip_innermost_template_args (args, 1);
17704 args = INNERMOST_TEMPLATE_ARGS (args);
17707 for (t = DECL_TEMPLATE_SPECIALIZATIONS (tmpl); t; t = TREE_CHAIN (t))
17709 tree partial_spec_args;
17711 tree parms = TREE_VALUE (t);
17713 partial_spec_args = CLASSTYPE_TI_ARGS (TREE_TYPE (t));
17715 ++processing_template_decl;
17721 /* Discard the outer levels of args, and then substitute in the
17722 template args from the enclosing class. */
17723 partial_spec_args = INNERMOST_TEMPLATE_ARGS (partial_spec_args);
17724 partial_spec_args = tsubst_template_args
17725 (partial_spec_args, outer_args, tf_none, NULL_TREE);
17727 /* PARMS already refers to just the innermost parms, but the
17728 template parms in partial_spec_args had their levels lowered
17729 by tsubst, so we need to do the same for the parm list. We
17730 can't just tsubst the TREE_VEC itself, as tsubst wants to
17731 treat a TREE_VEC as an argument vector. */
17732 parms = copy_node (parms);
17733 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
17734 TREE_VEC_ELT (parms, i) =
17735 tsubst (TREE_VEC_ELT (parms, i), outer_args, tf_none, NULL_TREE);
17739 partial_spec_args =
17740 coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
17741 add_to_template_args (outer_args,
17742 partial_spec_args),
17744 /*require_all_args=*/true,
17745 /*use_default_args=*/true);
17747 --processing_template_decl;
17749 if (partial_spec_args == error_mark_node)
17750 return error_mark_node;
17752 spec_args = get_class_bindings (parms,
17758 spec_args = add_to_template_args (outer_args, spec_args);
17759 list = tree_cons (spec_args, TREE_VALUE (t), list);
17760 TREE_TYPE (list) = TREE_TYPE (t);
17767 ambiguous_p = false;
17770 t = TREE_CHAIN (t);
17771 for (; t; t = TREE_CHAIN (t))
17773 fate = more_specialized_class (champ, t);
17780 t = TREE_CHAIN (t);
17783 ambiguous_p = true;
17792 for (t = list; t && t != champ; t = TREE_CHAIN (t))
17794 fate = more_specialized_class (champ, t);
17797 ambiguous_p = true;
17805 char *spaces = NULL;
17806 if (!(complain & tf_error))
17807 return error_mark_node;
17808 error ("ambiguous class template instantiation for %q#T", type);
17809 str = ngettext ("candidate is:", "candidates are:", list_length (list));
17810 for (t = list; t; t = TREE_CHAIN (t))
17812 error ("%s %+#T", spaces ? spaces : str, TREE_TYPE (t));
17813 spaces = spaces ? spaces : get_spaces (str);
17816 return error_mark_node;
17822 /* Explicitly instantiate DECL. */
17825 do_decl_instantiation (tree decl, tree storage)
17827 tree result = NULL_TREE;
17830 if (!decl || decl == error_mark_node)
17831 /* An error occurred, for which grokdeclarator has already issued
17832 an appropriate message. */
17834 else if (! DECL_LANG_SPECIFIC (decl))
17836 error ("explicit instantiation of non-template %q#D", decl);
17839 else if (TREE_CODE (decl) == VAR_DECL)
17841 /* There is an asymmetry here in the way VAR_DECLs and
17842 FUNCTION_DECLs are handled by grokdeclarator. In the case of
17843 the latter, the DECL we get back will be marked as a
17844 template instantiation, and the appropriate
17845 DECL_TEMPLATE_INFO will be set up. This does not happen for
17846 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
17847 should handle VAR_DECLs as it currently handles
17849 if (!DECL_CLASS_SCOPE_P (decl))
17851 error ("%qD is not a static data member of a class template", decl);
17854 result = lookup_field (DECL_CONTEXT (decl), DECL_NAME (decl), 0, false);
17855 if (!result || TREE_CODE (result) != VAR_DECL)
17857 error ("no matching template for %qD found", decl);
17860 if (!same_type_p (TREE_TYPE (result), TREE_TYPE (decl)))
17862 error ("type %qT for explicit instantiation %qD does not match "
17863 "declared type %qT", TREE_TYPE (result), decl,
17868 else if (TREE_CODE (decl) != FUNCTION_DECL)
17870 error ("explicit instantiation of %q#D", decl);
17876 /* Check for various error cases. Note that if the explicit
17877 instantiation is valid the RESULT will currently be marked as an
17878 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
17879 until we get here. */
17881 if (DECL_TEMPLATE_SPECIALIZATION (result))
17883 /* DR 259 [temp.spec].
17885 Both an explicit instantiation and a declaration of an explicit
17886 specialization shall not appear in a program unless the explicit
17887 instantiation follows a declaration of the explicit specialization.
17889 For a given set of template parameters, if an explicit
17890 instantiation of a template appears after a declaration of an
17891 explicit specialization for that template, the explicit
17892 instantiation has no effect. */
17895 else if (DECL_EXPLICIT_INSTANTIATION (result))
17899 No program shall explicitly instantiate any template more
17902 We check DECL_NOT_REALLY_EXTERN so as not to complain when
17903 the first instantiation was `extern' and the second is not,
17904 and EXTERN_P for the opposite case. */
17905 if (DECL_NOT_REALLY_EXTERN (result) && !extern_p)
17906 permerror (input_location, "duplicate explicit instantiation of %q#D", result);
17907 /* If an "extern" explicit instantiation follows an ordinary
17908 explicit instantiation, the template is instantiated. */
17912 else if (!DECL_IMPLICIT_INSTANTIATION (result))
17914 error ("no matching template for %qD found", result);
17917 else if (!DECL_TEMPLATE_INFO (result))
17919 permerror (input_location, "explicit instantiation of non-template %q#D", result);
17923 if (storage == NULL_TREE)
17925 else if (storage == ridpointers[(int) RID_EXTERN])
17927 if (!in_system_header && (cxx_dialect == cxx98))
17928 pedwarn (input_location, OPT_pedantic,
17929 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
17934 error ("storage class %qD applied to template instantiation", storage);
17936 check_explicit_instantiation_namespace (result);
17937 mark_decl_instantiated (result, extern_p);
17939 instantiate_decl (result, /*defer_ok=*/1,
17940 /*expl_inst_class_mem_p=*/false);
17944 mark_class_instantiated (tree t, int extern_p)
17946 SET_CLASSTYPE_EXPLICIT_INSTANTIATION (t);
17947 SET_CLASSTYPE_INTERFACE_KNOWN (t);
17948 CLASSTYPE_INTERFACE_ONLY (t) = extern_p;
17949 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (t)) = extern_p;
17952 CLASSTYPE_DEBUG_REQUESTED (t) = 1;
17953 rest_of_type_compilation (t, 1);
17957 /* Called from do_type_instantiation through binding_table_foreach to
17958 do recursive instantiation for the type bound in ENTRY. */
17960 bt_instantiate_type_proc (binding_entry entry, void *data)
17962 tree storage = *(tree *) data;
17964 if (MAYBE_CLASS_TYPE_P (entry->type)
17965 && !uses_template_parms (CLASSTYPE_TI_ARGS (entry->type)))
17966 do_type_instantiation (TYPE_MAIN_DECL (entry->type), storage, 0);
17969 /* Called from do_type_instantiation to instantiate a member
17970 (a member function or a static member variable) of an
17971 explicitly instantiated class template. */
17973 instantiate_class_member (tree decl, int extern_p)
17975 mark_decl_instantiated (decl, extern_p);
17977 instantiate_decl (decl, /*defer_ok=*/1,
17978 /*expl_inst_class_mem_p=*/true);
17981 /* Perform an explicit instantiation of template class T. STORAGE, if
17982 non-null, is the RID for extern, inline or static. COMPLAIN is
17983 nonzero if this is called from the parser, zero if called recursively,
17984 since the standard is unclear (as detailed below). */
17987 do_type_instantiation (tree t, tree storage, tsubst_flags_t complain)
17992 int previous_instantiation_extern_p = 0;
17994 if (TREE_CODE (t) == TYPE_DECL)
17997 if (! CLASS_TYPE_P (t) || ! CLASSTYPE_TEMPLATE_INFO (t))
18000 (TYPE_TEMPLATE_INFO (t)) ? TYPE_TI_TEMPLATE (t) : NULL;
18002 error ("explicit instantiation of non-class template %qD", tmpl);
18004 error ("explicit instantiation of non-template type %qT", t);
18010 if (!COMPLETE_TYPE_P (t))
18012 if (complain & tf_error)
18013 error ("explicit instantiation of %q#T before definition of template",
18018 if (storage != NULL_TREE)
18020 if (!in_system_header)
18022 if (storage == ridpointers[(int) RID_EXTERN])
18024 if (cxx_dialect == cxx98)
18025 pedwarn (input_location, OPT_pedantic,
18026 "ISO C++ 1998 forbids the use of %<extern%> on "
18027 "explicit instantiations");
18030 pedwarn (input_location, OPT_pedantic,
18031 "ISO C++ forbids the use of %qE"
18032 " on explicit instantiations", storage);
18035 if (storage == ridpointers[(int) RID_INLINE])
18037 else if (storage == ridpointers[(int) RID_EXTERN])
18039 else if (storage == ridpointers[(int) RID_STATIC])
18043 error ("storage class %qD applied to template instantiation",
18049 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (t))
18051 /* DR 259 [temp.spec].
18053 Both an explicit instantiation and a declaration of an explicit
18054 specialization shall not appear in a program unless the explicit
18055 instantiation follows a declaration of the explicit specialization.
18057 For a given set of template parameters, if an explicit
18058 instantiation of a template appears after a declaration of an
18059 explicit specialization for that template, the explicit
18060 instantiation has no effect. */
18063 else if (CLASSTYPE_EXPLICIT_INSTANTIATION (t))
18067 No program shall explicitly instantiate any template more
18070 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
18071 instantiation was `extern'. If EXTERN_P then the second is.
18072 These cases are OK. */
18073 previous_instantiation_extern_p = CLASSTYPE_INTERFACE_ONLY (t);
18075 if (!previous_instantiation_extern_p && !extern_p
18076 && (complain & tf_error))
18077 permerror (input_location, "duplicate explicit instantiation of %q#T", t);
18079 /* If we've already instantiated the template, just return now. */
18080 if (!CLASSTYPE_INTERFACE_ONLY (t))
18084 check_explicit_instantiation_namespace (TYPE_NAME (t));
18085 mark_class_instantiated (t, extern_p);
18093 /* In contrast to implicit instantiation, where only the
18094 declarations, and not the definitions, of members are
18095 instantiated, we have here:
18099 The explicit instantiation of a class template specialization
18100 implies the instantiation of all of its members not
18101 previously explicitly specialized in the translation unit
18102 containing the explicit instantiation.
18104 Of course, we can't instantiate member template classes, since
18105 we don't have any arguments for them. Note that the standard
18106 is unclear on whether the instantiation of the members are
18107 *explicit* instantiations or not. However, the most natural
18108 interpretation is that it should be an explicit instantiation. */
18111 for (tmp = TYPE_METHODS (t); tmp; tmp = DECL_CHAIN (tmp))
18112 if (TREE_CODE (tmp) == FUNCTION_DECL
18113 && DECL_TEMPLATE_INSTANTIATION (tmp))
18114 instantiate_class_member (tmp, extern_p);
18116 for (tmp = TYPE_FIELDS (t); tmp; tmp = DECL_CHAIN (tmp))
18117 if (TREE_CODE (tmp) == VAR_DECL && DECL_TEMPLATE_INSTANTIATION (tmp))
18118 instantiate_class_member (tmp, extern_p);
18120 if (CLASSTYPE_NESTED_UTDS (t))
18121 binding_table_foreach (CLASSTYPE_NESTED_UTDS (t),
18122 bt_instantiate_type_proc, &storage);
18126 /* Given a function DECL, which is a specialization of TMPL, modify
18127 DECL to be a re-instantiation of TMPL with the same template
18128 arguments. TMPL should be the template into which tsubst'ing
18129 should occur for DECL, not the most general template.
18131 One reason for doing this is a scenario like this:
18134 void f(const T&, int i);
18136 void g() { f(3, 7); }
18139 void f(const T& t, const int i) { }
18141 Note that when the template is first instantiated, with
18142 instantiate_template, the resulting DECL will have no name for the
18143 first parameter, and the wrong type for the second. So, when we go
18144 to instantiate the DECL, we regenerate it. */
18147 regenerate_decl_from_template (tree decl, tree tmpl)
18149 /* The arguments used to instantiate DECL, from the most general
18154 args = DECL_TI_ARGS (decl);
18155 code_pattern = DECL_TEMPLATE_RESULT (tmpl);
18157 /* Make sure that we can see identifiers, and compute access
18159 push_access_scope (decl);
18161 if (TREE_CODE (decl) == FUNCTION_DECL)
18169 args_depth = TMPL_ARGS_DEPTH (args);
18170 parms_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
18171 if (args_depth > parms_depth)
18172 args = get_innermost_template_args (args, parms_depth);
18174 specs = tsubst_exception_specification (TREE_TYPE (code_pattern),
18175 args, tf_error, NULL_TREE,
18176 /*defer_ok*/false);
18177 if (specs && specs != error_mark_node)
18178 TREE_TYPE (decl) = build_exception_variant (TREE_TYPE (decl),
18181 /* Merge parameter declarations. */
18182 decl_parm = skip_artificial_parms_for (decl,
18183 DECL_ARGUMENTS (decl));
18185 = skip_artificial_parms_for (code_pattern,
18186 DECL_ARGUMENTS (code_pattern));
18187 while (decl_parm && !FUNCTION_PARAMETER_PACK_P (pattern_parm))
18192 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
18193 DECL_NAME (decl_parm) = DECL_NAME (pattern_parm);
18194 parm_type = tsubst (TREE_TYPE (pattern_parm), args, tf_error,
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);
18206 pattern_parm = DECL_CHAIN (pattern_parm);
18208 /* Merge any parameters that match with the function parameter
18210 if (pattern_parm && FUNCTION_PARAMETER_PACK_P (pattern_parm))
18213 tree expanded_types;
18214 /* Expand the TYPE_PACK_EXPANSION that provides the types for
18215 the parameters in this function parameter pack. */
18216 expanded_types = tsubst_pack_expansion (TREE_TYPE (pattern_parm),
18217 args, tf_error, NULL_TREE);
18218 len = TREE_VEC_LENGTH (expanded_types);
18219 for (i = 0; i < len; i++)
18224 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
18225 /* Rename the parameter to include the index. */
18226 DECL_NAME (decl_parm) =
18227 make_ith_pack_parameter_name (DECL_NAME (pattern_parm), i);
18228 parm_type = TREE_VEC_ELT (expanded_types, i);
18229 parm_type = type_decays_to (parm_type);
18230 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
18231 TREE_TYPE (decl_parm) = parm_type;
18232 attributes = DECL_ATTRIBUTES (pattern_parm);
18233 if (DECL_ATTRIBUTES (decl_parm) != attributes)
18235 DECL_ATTRIBUTES (decl_parm) = attributes;
18236 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
18238 decl_parm = DECL_CHAIN (decl_parm);
18241 /* Merge additional specifiers from the CODE_PATTERN. */
18242 if (DECL_DECLARED_INLINE_P (code_pattern)
18243 && !DECL_DECLARED_INLINE_P (decl))
18244 DECL_DECLARED_INLINE_P (decl) = 1;
18246 else if (TREE_CODE (decl) == VAR_DECL)
18248 DECL_INITIAL (decl) =
18249 tsubst_expr (DECL_INITIAL (code_pattern), args,
18250 tf_error, DECL_TI_TEMPLATE (decl),
18251 /*integral_constant_expression_p=*/false);
18252 if (VAR_HAD_UNKNOWN_BOUND (decl))
18253 TREE_TYPE (decl) = tsubst (TREE_TYPE (code_pattern), args,
18254 tf_error, DECL_TI_TEMPLATE (decl));
18257 gcc_unreachable ();
18259 pop_access_scope (decl);
18262 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
18263 substituted to get DECL. */
18266 template_for_substitution (tree decl)
18268 tree tmpl = DECL_TI_TEMPLATE (decl);
18270 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
18271 for the instantiation. This is not always the most general
18272 template. Consider, for example:
18275 struct S { template <class U> void f();
18276 template <> void f<int>(); };
18278 and an instantiation of S<double>::f<int>. We want TD to be the
18279 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
18280 while (/* An instantiation cannot have a definition, so we need a
18281 more general template. */
18282 DECL_TEMPLATE_INSTANTIATION (tmpl)
18283 /* We must also deal with friend templates. Given:
18285 template <class T> struct S {
18286 template <class U> friend void f() {};
18289 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
18290 so far as the language is concerned, but that's still
18291 where we get the pattern for the instantiation from. On
18292 other hand, if the definition comes outside the class, say:
18294 template <class T> struct S {
18295 template <class U> friend void f();
18297 template <class U> friend void f() {}
18299 we don't need to look any further. That's what the check for
18300 DECL_INITIAL is for. */
18301 || (TREE_CODE (decl) == FUNCTION_DECL
18302 && DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION (tmpl)
18303 && !DECL_INITIAL (DECL_TEMPLATE_RESULT (tmpl))))
18305 /* The present template, TD, should not be a definition. If it
18306 were a definition, we should be using it! Note that we
18307 cannot restructure the loop to just keep going until we find
18308 a template with a definition, since that might go too far if
18309 a specialization was declared, but not defined. */
18310 gcc_assert (TREE_CODE (decl) != VAR_DECL
18311 || DECL_IN_AGGR_P (DECL_TEMPLATE_RESULT (tmpl)));
18313 /* Fetch the more general template. */
18314 tmpl = DECL_TI_TEMPLATE (tmpl);
18320 /* Returns true if we need to instantiate this template instance even if we
18321 know we aren't going to emit it.. */
18324 always_instantiate_p (tree decl)
18326 /* We always instantiate inline functions so that we can inline them. An
18327 explicit instantiation declaration prohibits implicit instantiation of
18328 non-inline functions. With high levels of optimization, we would
18329 normally inline non-inline functions -- but we're not allowed to do
18330 that for "extern template" functions. Therefore, we check
18331 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
18332 return ((TREE_CODE (decl) == FUNCTION_DECL
18333 && DECL_DECLARED_INLINE_P (decl))
18334 /* And we need to instantiate static data members so that
18335 their initializers are available in integral constant
18337 || (TREE_CODE (decl) == VAR_DECL
18338 && decl_maybe_constant_var_p (decl)));
18341 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
18342 instantiate it now, modifying TREE_TYPE (fn). */
18345 maybe_instantiate_noexcept (tree fn)
18347 tree fntype, spec, noex, clone;
18349 if (DECL_CLONED_FUNCTION_P (fn))
18350 fn = DECL_CLONED_FUNCTION (fn);
18351 fntype = TREE_TYPE (fn);
18352 spec = TYPE_RAISES_EXCEPTIONS (fntype);
18354 if (!DEFERRED_NOEXCEPT_SPEC_P (spec))
18357 noex = TREE_PURPOSE (spec);
18359 if (TREE_CODE (noex) == DEFERRED_NOEXCEPT)
18361 if (push_tinst_level (fn))
18363 push_access_scope (fn);
18364 input_location = DECL_SOURCE_LOCATION (fn);
18365 noex = tsubst_copy_and_build (DEFERRED_NOEXCEPT_PATTERN (noex),
18366 DEFERRED_NOEXCEPT_ARGS (noex),
18367 tf_warning_or_error, fn,
18368 /*function_p=*/false,
18369 /*integral_constant_expression_p=*/true);
18370 pop_access_scope (fn);
18371 pop_tinst_level ();
18372 spec = build_noexcept_spec (noex, tf_warning_or_error);
18373 if (spec == error_mark_node)
18374 spec = noexcept_false_spec;
18377 spec = noexcept_false_spec;
18381 /* This is an implicitly declared function, so NOEX is a list of
18382 other functions to evaluate and merge. */
18384 spec = noexcept_true_spec;
18385 for (elt = noex; elt; elt = OVL_NEXT (elt))
18387 tree fn = OVL_CURRENT (elt);
18389 maybe_instantiate_noexcept (fn);
18390 subspec = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (fn));
18391 spec = merge_exception_specifiers (spec, subspec, NULL_TREE);
18395 TREE_TYPE (fn) = build_exception_variant (fntype, spec);
18397 FOR_EACH_CLONE (clone, fn)
18399 if (TREE_TYPE (clone) == fntype)
18400 TREE_TYPE (clone) = TREE_TYPE (fn);
18402 TREE_TYPE (clone) = build_exception_variant (TREE_TYPE (clone), spec);
18406 /* Produce the definition of D, a _DECL generated from a template. If
18407 DEFER_OK is nonzero, then we don't have to actually do the
18408 instantiation now; we just have to do it sometime. Normally it is
18409 an error if this is an explicit instantiation but D is undefined.
18410 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
18411 explicitly instantiated class template. */
18414 instantiate_decl (tree d, int defer_ok,
18415 bool expl_inst_class_mem_p)
18417 tree tmpl = DECL_TI_TEMPLATE (d);
18424 bool pattern_defined;
18426 location_t saved_loc = input_location;
18429 /* This function should only be used to instantiate templates for
18430 functions and static member variables. */
18431 gcc_assert (TREE_CODE (d) == FUNCTION_DECL
18432 || TREE_CODE (d) == VAR_DECL);
18434 /* Variables are never deferred; if instantiation is required, they
18435 are instantiated right away. That allows for better code in the
18436 case that an expression refers to the value of the variable --
18437 if the variable has a constant value the referring expression can
18438 take advantage of that fact. */
18439 if (TREE_CODE (d) == VAR_DECL
18440 || DECL_DECLARED_CONSTEXPR_P (d))
18443 /* Don't instantiate cloned functions. Instead, instantiate the
18444 functions they cloned. */
18445 if (TREE_CODE (d) == FUNCTION_DECL && DECL_CLONED_FUNCTION_P (d))
18446 d = DECL_CLONED_FUNCTION (d);
18448 if (DECL_TEMPLATE_INSTANTIATED (d)
18449 || (TREE_CODE (d) == FUNCTION_DECL
18450 && DECL_DEFAULTED_FN (d) && DECL_INITIAL (d))
18451 || DECL_TEMPLATE_SPECIALIZATION (d))
18452 /* D has already been instantiated or explicitly specialized, so
18453 there's nothing for us to do here.
18455 It might seem reasonable to check whether or not D is an explicit
18456 instantiation, and, if so, stop here. But when an explicit
18457 instantiation is deferred until the end of the compilation,
18458 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
18459 the instantiation. */
18462 /* Check to see whether we know that this template will be
18463 instantiated in some other file, as with "extern template"
18465 external_p = (DECL_INTERFACE_KNOWN (d) && DECL_REALLY_EXTERN (d));
18467 /* In general, we do not instantiate such templates. */
18468 if (external_p && !always_instantiate_p (d))
18471 gen_tmpl = most_general_template (tmpl);
18472 gen_args = DECL_TI_ARGS (d);
18474 if (tmpl != gen_tmpl)
18475 /* We should already have the extra args. */
18476 gcc_assert (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (gen_tmpl))
18477 == TMPL_ARGS_DEPTH (gen_args));
18478 /* And what's in the hash table should match D. */
18479 gcc_assert ((spec = retrieve_specialization (gen_tmpl, gen_args, 0)) == d
18480 || spec == NULL_TREE);
18482 /* This needs to happen before any tsubsting. */
18483 if (! push_tinst_level (d))
18486 timevar_push (TV_TEMPLATE_INST);
18488 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
18489 for the instantiation. */
18490 td = template_for_substitution (d);
18491 code_pattern = DECL_TEMPLATE_RESULT (td);
18493 /* We should never be trying to instantiate a member of a class
18494 template or partial specialization. */
18495 gcc_assert (d != code_pattern);
18497 if ((DECL_NAMESPACE_SCOPE_P (d) && !DECL_INITIALIZED_IN_CLASS_P (d))
18498 || DECL_TEMPLATE_SPECIALIZATION (td))
18499 /* In the case of a friend template whose definition is provided
18500 outside the class, we may have too many arguments. Drop the
18501 ones we don't need. The same is true for specializations. */
18502 args = get_innermost_template_args
18503 (gen_args, TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (td)));
18507 if (TREE_CODE (d) == FUNCTION_DECL)
18508 pattern_defined = (DECL_SAVED_TREE (code_pattern) != NULL_TREE
18509 || DECL_DEFAULTED_OUTSIDE_CLASS_P (code_pattern));
18511 pattern_defined = ! DECL_IN_AGGR_P (code_pattern);
18513 /* We may be in the middle of deferred access check. Disable it now. */
18514 push_deferring_access_checks (dk_no_deferred);
18516 /* Unless an explicit instantiation directive has already determined
18517 the linkage of D, remember that a definition is available for
18519 if (pattern_defined
18520 && !DECL_INTERFACE_KNOWN (d)
18521 && !DECL_NOT_REALLY_EXTERN (d))
18522 mark_definable (d);
18524 DECL_SOURCE_LOCATION (td) = DECL_SOURCE_LOCATION (code_pattern);
18525 DECL_SOURCE_LOCATION (d) = DECL_SOURCE_LOCATION (code_pattern);
18526 input_location = DECL_SOURCE_LOCATION (d);
18528 /* If D is a member of an explicitly instantiated class template,
18529 and no definition is available, treat it like an implicit
18531 if (!pattern_defined && expl_inst_class_mem_p
18532 && DECL_EXPLICIT_INSTANTIATION (d))
18534 /* Leave linkage flags alone on instantiations with anonymous
18536 if (TREE_PUBLIC (d))
18538 DECL_NOT_REALLY_EXTERN (d) = 0;
18539 DECL_INTERFACE_KNOWN (d) = 0;
18541 SET_DECL_IMPLICIT_INSTANTIATION (d);
18544 if (TREE_CODE (d) == FUNCTION_DECL)
18545 maybe_instantiate_noexcept (d);
18547 /* Recheck the substitutions to obtain any warning messages
18548 about ignoring cv qualifiers. Don't do this for artificial decls,
18549 as it breaks the context-sensitive substitution for lambda op(). */
18550 if (!defer_ok && !DECL_ARTIFICIAL (d))
18552 tree gen = DECL_TEMPLATE_RESULT (gen_tmpl);
18553 tree type = TREE_TYPE (gen);
18555 /* Make sure that we can see identifiers, and compute access
18556 correctly. D is already the target FUNCTION_DECL with the
18558 push_access_scope (d);
18560 if (TREE_CODE (gen) == FUNCTION_DECL)
18562 tsubst (DECL_ARGUMENTS (gen), gen_args, tf_warning_or_error, d);
18563 tsubst_exception_specification (type, gen_args, tf_warning_or_error,
18564 d, /*defer_ok*/true);
18565 /* Don't simply tsubst the function type, as that will give
18566 duplicate warnings about poor parameter qualifications.
18567 The function arguments are the same as the decl_arguments
18568 without the top level cv qualifiers. */
18569 type = TREE_TYPE (type);
18571 tsubst (type, gen_args, tf_warning_or_error, d);
18573 pop_access_scope (d);
18576 /* Defer all other templates, unless we have been explicitly
18577 forbidden from doing so. */
18578 if (/* If there is no definition, we cannot instantiate the
18581 /* If it's OK to postpone instantiation, do so. */
18583 /* If this is a static data member that will be defined
18584 elsewhere, we don't want to instantiate the entire data
18585 member, but we do want to instantiate the initializer so that
18586 we can substitute that elsewhere. */
18587 || (external_p && TREE_CODE (d) == VAR_DECL))
18589 /* The definition of the static data member is now required so
18590 we must substitute the initializer. */
18591 if (TREE_CODE (d) == VAR_DECL
18592 && !DECL_INITIAL (d)
18593 && DECL_INITIAL (code_pattern))
18597 bool const_init = false;
18599 ns = decl_namespace_context (d);
18600 push_nested_namespace (ns);
18601 push_nested_class (DECL_CONTEXT (d));
18602 init = tsubst_expr (DECL_INITIAL (code_pattern),
18604 tf_warning_or_error, NULL_TREE,
18605 /*integral_constant_expression_p=*/false);
18606 /* Make sure the initializer is still constant, in case of
18607 circular dependency (template/instantiate6.C). */
18609 = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (code_pattern);
18610 cp_finish_decl (d, init, /*init_const_expr_p=*/const_init,
18611 /*asmspec_tree=*/NULL_TREE,
18612 LOOKUP_ONLYCONVERTING);
18613 pop_nested_class ();
18614 pop_nested_namespace (ns);
18617 /* We restore the source position here because it's used by
18618 add_pending_template. */
18619 input_location = saved_loc;
18621 if (at_eof && !pattern_defined
18622 && DECL_EXPLICIT_INSTANTIATION (d)
18623 && DECL_NOT_REALLY_EXTERN (d))
18626 The definition of a non-exported function template, a
18627 non-exported member function template, or a non-exported
18628 member function or static data member of a class template
18629 shall be present in every translation unit in which it is
18630 explicitly instantiated. */
18631 permerror (input_location, "explicit instantiation of %qD "
18632 "but no definition available", d);
18634 /* If we're in unevaluated context, we just wanted to get the
18635 constant value; this isn't an odr use, so don't queue
18636 a full instantiation. */
18637 if (cp_unevaluated_operand != 0)
18639 /* ??? Historically, we have instantiated inline functions, even
18640 when marked as "extern template". */
18641 if (!(external_p && TREE_CODE (d) == VAR_DECL))
18642 add_pending_template (d);
18645 /* Tell the repository that D is available in this translation unit
18646 -- and see if it is supposed to be instantiated here. */
18647 if (TREE_PUBLIC (d) && !DECL_REALLY_EXTERN (d) && !repo_emit_p (d))
18649 /* In a PCH file, despite the fact that the repository hasn't
18650 requested instantiation in the PCH it is still possible that
18651 an instantiation will be required in a file that includes the
18654 add_pending_template (d);
18655 /* Instantiate inline functions so that the inliner can do its
18656 job, even though we'll not be emitting a copy of this
18658 if (!(TREE_CODE (d) == FUNCTION_DECL && possibly_inlined_p (d)))
18662 need_push = !cfun || !global_bindings_p ();
18664 push_to_top_level ();
18666 /* Mark D as instantiated so that recursive calls to
18667 instantiate_decl do not try to instantiate it again. */
18668 DECL_TEMPLATE_INSTANTIATED (d) = 1;
18670 /* Regenerate the declaration in case the template has been modified
18671 by a subsequent redeclaration. */
18672 regenerate_decl_from_template (d, td);
18674 /* We already set the file and line above. Reset them now in case
18675 they changed as a result of calling regenerate_decl_from_template. */
18676 input_location = DECL_SOURCE_LOCATION (d);
18678 if (TREE_CODE (d) == VAR_DECL)
18681 bool const_init = false;
18683 /* Clear out DECL_RTL; whatever was there before may not be right
18684 since we've reset the type of the declaration. */
18685 SET_DECL_RTL (d, NULL);
18686 DECL_IN_AGGR_P (d) = 0;
18688 /* The initializer is placed in DECL_INITIAL by
18689 regenerate_decl_from_template so we don't need to
18690 push/pop_access_scope again here. Pull it out so that
18691 cp_finish_decl can process it. */
18692 init = DECL_INITIAL (d);
18693 DECL_INITIAL (d) = NULL_TREE;
18694 DECL_INITIALIZED_P (d) = 0;
18696 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
18697 initializer. That function will defer actual emission until
18698 we have a chance to determine linkage. */
18699 DECL_EXTERNAL (d) = 0;
18701 /* Enter the scope of D so that access-checking works correctly. */
18702 push_nested_class (DECL_CONTEXT (d));
18703 const_init = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (code_pattern);
18704 cp_finish_decl (d, init, const_init, NULL_TREE, 0);
18705 pop_nested_class ();
18707 else if (TREE_CODE (d) == FUNCTION_DECL && DECL_DEFAULTED_FN (code_pattern))
18708 synthesize_method (d);
18709 else if (TREE_CODE (d) == FUNCTION_DECL)
18711 htab_t saved_local_specializations;
18716 /* Save away the current list, in case we are instantiating one
18717 template from within the body of another. */
18718 saved_local_specializations = local_specializations;
18720 /* Set up the list of local specializations. */
18721 local_specializations = htab_create (37,
18722 hash_local_specialization,
18723 eq_local_specializations,
18726 /* Set up context. */
18727 start_preparsed_function (d, NULL_TREE, SF_PRE_PARSED);
18729 /* Create substitution entries for the parameters. */
18730 subst_decl = DECL_TEMPLATE_RESULT (template_for_substitution (d));
18731 tmpl_parm = DECL_ARGUMENTS (subst_decl);
18732 spec_parm = DECL_ARGUMENTS (d);
18733 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (d))
18735 register_local_specialization (spec_parm, tmpl_parm);
18736 spec_parm = skip_artificial_parms_for (d, spec_parm);
18737 tmpl_parm = skip_artificial_parms_for (subst_decl, tmpl_parm);
18739 for (; tmpl_parm; tmpl_parm = DECL_CHAIN (tmpl_parm))
18741 if (!FUNCTION_PARAMETER_PACK_P (tmpl_parm))
18743 register_local_specialization (spec_parm, tmpl_parm);
18744 spec_parm = DECL_CHAIN (spec_parm);
18748 /* Register the (value) argument pack as a specialization of
18749 TMPL_PARM, then move on. */
18750 tree argpack = extract_fnparm_pack (tmpl_parm, &spec_parm);
18751 register_local_specialization (argpack, tmpl_parm);
18754 gcc_assert (!spec_parm);
18756 /* Substitute into the body of the function. */
18757 tsubst_expr (DECL_SAVED_TREE (code_pattern), args,
18758 tf_warning_or_error, tmpl,
18759 /*integral_constant_expression_p=*/false);
18761 /* Set the current input_location to the end of the function
18762 so that finish_function knows where we are. */
18763 input_location = DECL_STRUCT_FUNCTION (code_pattern)->function_end_locus;
18765 /* We don't need the local specializations any more. */
18766 htab_delete (local_specializations);
18767 local_specializations = saved_local_specializations;
18769 /* Finish the function. */
18770 d = finish_function (0);
18771 expand_or_defer_fn (d);
18774 /* We're not deferring instantiation any more. */
18775 TI_PENDING_TEMPLATE_FLAG (DECL_TEMPLATE_INFO (d)) = 0;
18778 pop_from_top_level ();
18781 input_location = saved_loc;
18782 pop_deferring_access_checks ();
18783 pop_tinst_level ();
18785 timevar_pop (TV_TEMPLATE_INST);
18790 /* Run through the list of templates that we wish we could
18791 instantiate, and instantiate any we can. RETRIES is the
18792 number of times we retry pending template instantiation. */
18795 instantiate_pending_templates (int retries)
18798 location_t saved_loc = input_location;
18800 /* Instantiating templates may trigger vtable generation. This in turn
18801 may require further template instantiations. We place a limit here
18802 to avoid infinite loop. */
18803 if (pending_templates && retries >= max_tinst_depth)
18805 tree decl = pending_templates->tinst->decl;
18807 error ("template instantiation depth exceeds maximum of %d"
18808 " instantiating %q+D, possibly from virtual table generation"
18809 " (use -ftemplate-depth= to increase the maximum)",
18810 max_tinst_depth, decl);
18811 if (TREE_CODE (decl) == FUNCTION_DECL)
18812 /* Pretend that we defined it. */
18813 DECL_INITIAL (decl) = error_mark_node;
18819 struct pending_template **t = &pending_templates;
18820 struct pending_template *last = NULL;
18824 tree instantiation = reopen_tinst_level ((*t)->tinst);
18825 bool complete = false;
18827 if (TYPE_P (instantiation))
18831 if (!COMPLETE_TYPE_P (instantiation))
18833 instantiate_class_template (instantiation);
18834 if (CLASSTYPE_TEMPLATE_INSTANTIATION (instantiation))
18835 for (fn = TYPE_METHODS (instantiation);
18837 fn = TREE_CHAIN (fn))
18838 if (! DECL_ARTIFICIAL (fn))
18839 instantiate_decl (fn,
18841 /*expl_inst_class_mem_p=*/false);
18842 if (COMPLETE_TYPE_P (instantiation))
18846 complete = COMPLETE_TYPE_P (instantiation);
18850 if (!DECL_TEMPLATE_SPECIALIZATION (instantiation)
18851 && !DECL_TEMPLATE_INSTANTIATED (instantiation))
18854 = instantiate_decl (instantiation,
18856 /*expl_inst_class_mem_p=*/false);
18857 if (DECL_TEMPLATE_INSTANTIATED (instantiation))
18861 complete = (DECL_TEMPLATE_SPECIALIZATION (instantiation)
18862 || DECL_TEMPLATE_INSTANTIATED (instantiation));
18866 /* If INSTANTIATION has been instantiated, then we don't
18867 need to consider it again in the future. */
18875 current_tinst_level = NULL;
18877 last_pending_template = last;
18879 while (reconsider);
18881 input_location = saved_loc;
18884 /* Substitute ARGVEC into T, which is a list of initializers for
18885 either base class or a non-static data member. The TREE_PURPOSEs
18886 are DECLs, and the TREE_VALUEs are the initializer values. Used by
18887 instantiate_decl. */
18890 tsubst_initializer_list (tree t, tree argvec)
18892 tree inits = NULL_TREE;
18894 for (; t; t = TREE_CHAIN (t))
18898 tree expanded_bases = NULL_TREE;
18899 tree expanded_arguments = NULL_TREE;
18902 if (TREE_CODE (TREE_PURPOSE (t)) == TYPE_PACK_EXPANSION)
18907 /* Expand the base class expansion type into separate base
18909 expanded_bases = tsubst_pack_expansion (TREE_PURPOSE (t), argvec,
18910 tf_warning_or_error,
18912 if (expanded_bases == error_mark_node)
18915 /* We'll be building separate TREE_LISTs of arguments for
18917 len = TREE_VEC_LENGTH (expanded_bases);
18918 expanded_arguments = make_tree_vec (len);
18919 for (i = 0; i < len; i++)
18920 TREE_VEC_ELT (expanded_arguments, i) = NULL_TREE;
18922 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
18923 expand each argument in the TREE_VALUE of t. */
18924 expr = make_node (EXPR_PACK_EXPANSION);
18925 PACK_EXPANSION_LOCAL_P (expr) = true;
18926 PACK_EXPANSION_PARAMETER_PACKS (expr) =
18927 PACK_EXPANSION_PARAMETER_PACKS (TREE_PURPOSE (t));
18929 if (TREE_VALUE (t) == void_type_node)
18930 /* VOID_TYPE_NODE is used to indicate
18931 value-initialization. */
18933 for (i = 0; i < len; i++)
18934 TREE_VEC_ELT (expanded_arguments, i) = void_type_node;
18938 /* Substitute parameter packs into each argument in the
18940 in_base_initializer = 1;
18941 for (arg = TREE_VALUE (t); arg; arg = TREE_CHAIN (arg))
18943 tree expanded_exprs;
18945 /* Expand the argument. */
18946 SET_PACK_EXPANSION_PATTERN (expr, TREE_VALUE (arg));
18948 = tsubst_pack_expansion (expr, argvec,
18949 tf_warning_or_error,
18951 if (expanded_exprs == error_mark_node)
18954 /* Prepend each of the expanded expressions to the
18955 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
18956 for (i = 0; i < len; i++)
18958 TREE_VEC_ELT (expanded_arguments, i) =
18959 tree_cons (NULL_TREE,
18960 TREE_VEC_ELT (expanded_exprs, i),
18961 TREE_VEC_ELT (expanded_arguments, i));
18964 in_base_initializer = 0;
18966 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
18967 since we built them backwards. */
18968 for (i = 0; i < len; i++)
18970 TREE_VEC_ELT (expanded_arguments, i) =
18971 nreverse (TREE_VEC_ELT (expanded_arguments, i));
18976 for (i = 0; i < len; ++i)
18978 if (expanded_bases)
18980 decl = TREE_VEC_ELT (expanded_bases, i);
18981 decl = expand_member_init (decl);
18982 init = TREE_VEC_ELT (expanded_arguments, i);
18986 decl = tsubst_copy (TREE_PURPOSE (t), argvec,
18987 tf_warning_or_error, NULL_TREE);
18989 decl = expand_member_init (decl);
18990 if (decl && !DECL_P (decl))
18991 in_base_initializer = 1;
18993 init = TREE_VALUE (t);
18994 if (init != void_type_node)
18995 init = tsubst_expr (init, argvec,
18996 tf_warning_or_error, NULL_TREE,
18997 /*integral_constant_expression_p=*/false);
18998 in_base_initializer = 0;
19003 init = build_tree_list (decl, init);
19004 TREE_CHAIN (init) = inits;
19012 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
19015 set_current_access_from_decl (tree decl)
19017 if (TREE_PRIVATE (decl))
19018 current_access_specifier = access_private_node;
19019 else if (TREE_PROTECTED (decl))
19020 current_access_specifier = access_protected_node;
19022 current_access_specifier = access_public_node;
19025 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
19026 is the instantiation (which should have been created with
19027 start_enum) and ARGS are the template arguments to use. */
19030 tsubst_enum (tree tag, tree newtag, tree args)
19034 if (SCOPED_ENUM_P (newtag))
19035 begin_scope (sk_scoped_enum, newtag);
19037 for (e = TYPE_VALUES (tag); e; e = TREE_CHAIN (e))
19042 decl = TREE_VALUE (e);
19043 /* Note that in a template enum, the TREE_VALUE is the
19044 CONST_DECL, not the corresponding INTEGER_CST. */
19045 value = tsubst_expr (DECL_INITIAL (decl),
19046 args, tf_warning_or_error, NULL_TREE,
19047 /*integral_constant_expression_p=*/true);
19049 /* Give this enumeration constant the correct access. */
19050 set_current_access_from_decl (decl);
19052 /* Actually build the enumerator itself. */
19054 (DECL_NAME (decl), value, newtag, DECL_SOURCE_LOCATION (decl));
19057 if (SCOPED_ENUM_P (newtag))
19060 finish_enum_value_list (newtag);
19061 finish_enum (newtag);
19063 DECL_SOURCE_LOCATION (TYPE_NAME (newtag))
19064 = DECL_SOURCE_LOCATION (TYPE_NAME (tag));
19067 /* DECL is a FUNCTION_DECL that is a template specialization. Return
19068 its type -- but without substituting the innermost set of template
19069 arguments. So, innermost set of template parameters will appear in
19073 get_mostly_instantiated_function_type (tree decl)
19081 tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
19082 targs = DECL_TI_ARGS (decl);
19083 tparms = DECL_TEMPLATE_PARMS (tmpl);
19084 parm_depth = TMPL_PARMS_DEPTH (tparms);
19086 /* There should be as many levels of arguments as there are levels
19088 gcc_assert (parm_depth == TMPL_ARGS_DEPTH (targs));
19090 fn_type = TREE_TYPE (tmpl);
19092 if (parm_depth == 1)
19093 /* No substitution is necessary. */
19100 /* Replace the innermost level of the TARGS with NULL_TREEs to
19101 let tsubst know not to substitute for those parameters. */
19102 partial_args = make_tree_vec (TREE_VEC_LENGTH (targs));
19103 for (i = 1; i < TMPL_ARGS_DEPTH (targs); ++i)
19104 SET_TMPL_ARGS_LEVEL (partial_args, i,
19105 TMPL_ARGS_LEVEL (targs, i));
19106 SET_TMPL_ARGS_LEVEL (partial_args,
19107 TMPL_ARGS_DEPTH (targs),
19108 make_tree_vec (DECL_NTPARMS (tmpl)));
19110 /* Make sure that we can see identifiers, and compute access
19112 push_access_scope (decl);
19114 ++processing_template_decl;
19115 /* Now, do the (partial) substitution to figure out the
19116 appropriate function type. */
19117 fn_type = tsubst (fn_type, partial_args, tf_error, NULL_TREE);
19118 --processing_template_decl;
19120 /* Substitute into the template parameters to obtain the real
19121 innermost set of parameters. This step is important if the
19122 innermost set of template parameters contains value
19123 parameters whose types depend on outer template parameters. */
19124 TREE_VEC_LENGTH (partial_args)--;
19125 tparms = tsubst_template_parms (tparms, partial_args, tf_error);
19127 pop_access_scope (decl);
19133 /* Return truthvalue if we're processing a template different from
19134 the last one involved in diagnostics. */
19136 problematic_instantiation_changed (void)
19138 return current_tinst_level != last_error_tinst_level;
19141 /* Remember current template involved in diagnostics. */
19143 record_last_problematic_instantiation (void)
19145 last_error_tinst_level = current_tinst_level;
19148 struct tinst_level *
19149 current_instantiation (void)
19151 return current_tinst_level;
19154 /* [temp.param] Check that template non-type parm TYPE is of an allowable
19155 type. Return zero for ok, nonzero for disallowed. Issue error and
19156 warning messages under control of COMPLAIN. */
19159 invalid_nontype_parm_type_p (tree type, tsubst_flags_t complain)
19161 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
19163 else if (POINTER_TYPE_P (type))
19165 else if (TYPE_PTR_TO_MEMBER_P (type))
19167 else if (TREE_CODE (type) == TEMPLATE_TYPE_PARM)
19169 else if (TREE_CODE (type) == TYPENAME_TYPE)
19171 else if (TREE_CODE (type) == DECLTYPE_TYPE)
19173 else if (TREE_CODE (type) == NULLPTR_TYPE)
19176 if (complain & tf_error)
19178 if (type == error_mark_node)
19179 inform (input_location, "invalid template non-type parameter");
19181 error ("%q#T is not a valid type for a template non-type parameter",
19187 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
19188 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
19191 dependent_type_p_r (tree type)
19197 A type is dependent if it is:
19199 -- a template parameter. Template template parameters are types
19200 for us (since TYPE_P holds true for them) so we handle
19202 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
19203 || TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM)
19205 /* -- a qualified-id with a nested-name-specifier which contains a
19206 class-name that names a dependent type or whose unqualified-id
19207 names a dependent type. */
19208 if (TREE_CODE (type) == TYPENAME_TYPE)
19210 /* -- a cv-qualified type where the cv-unqualified type is
19212 type = TYPE_MAIN_VARIANT (type);
19213 /* -- a compound type constructed from any dependent type. */
19214 if (TYPE_PTR_TO_MEMBER_P (type))
19215 return (dependent_type_p (TYPE_PTRMEM_CLASS_TYPE (type))
19216 || dependent_type_p (TYPE_PTRMEM_POINTED_TO_TYPE
19218 else if (TREE_CODE (type) == POINTER_TYPE
19219 || TREE_CODE (type) == REFERENCE_TYPE)
19220 return dependent_type_p (TREE_TYPE (type));
19221 else if (TREE_CODE (type) == FUNCTION_TYPE
19222 || TREE_CODE (type) == METHOD_TYPE)
19226 if (dependent_type_p (TREE_TYPE (type)))
19228 for (arg_type = TYPE_ARG_TYPES (type);
19230 arg_type = TREE_CHAIN (arg_type))
19231 if (dependent_type_p (TREE_VALUE (arg_type)))
19235 /* -- an array type constructed from any dependent type or whose
19236 size is specified by a constant expression that is
19239 We checked for type- and value-dependence of the bounds in
19240 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
19241 if (TREE_CODE (type) == ARRAY_TYPE)
19243 if (TYPE_DOMAIN (type)
19244 && dependent_type_p (TYPE_DOMAIN (type)))
19246 return dependent_type_p (TREE_TYPE (type));
19249 /* -- a template-id in which either the template name is a template
19251 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
19253 /* ... or any of the template arguments is a dependent type or
19254 an expression that is type-dependent or value-dependent. */
19255 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INFO (type)
19256 && (any_dependent_template_arguments_p
19257 (INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type)))))
19260 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
19261 dependent; if the argument of the `typeof' expression is not
19262 type-dependent, then it should already been have resolved. */
19263 if (TREE_CODE (type) == TYPEOF_TYPE
19264 || TREE_CODE (type) == DECLTYPE_TYPE
19265 || TREE_CODE (type) == UNDERLYING_TYPE)
19268 /* A template argument pack is dependent if any of its packed
19270 if (TREE_CODE (type) == TYPE_ARGUMENT_PACK)
19272 tree args = ARGUMENT_PACK_ARGS (type);
19273 int i, len = TREE_VEC_LENGTH (args);
19274 for (i = 0; i < len; ++i)
19275 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
19279 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
19280 be template parameters. */
19281 if (TREE_CODE (type) == TYPE_PACK_EXPANSION)
19284 /* The standard does not specifically mention types that are local
19285 to template functions or local classes, but they should be
19286 considered dependent too. For example:
19288 template <int I> void f() {
19293 The size of `E' cannot be known until the value of `I' has been
19294 determined. Therefore, `E' must be considered dependent. */
19295 scope = TYPE_CONTEXT (type);
19296 if (scope && TYPE_P (scope))
19297 return dependent_type_p (scope);
19298 /* Don't use type_dependent_expression_p here, as it can lead
19299 to infinite recursion trying to determine whether a lambda
19300 nested in a lambda is dependent (c++/47687). */
19301 else if (scope && TREE_CODE (scope) == FUNCTION_DECL
19302 && DECL_LANG_SPECIFIC (scope)
19303 && DECL_TEMPLATE_INFO (scope)
19304 && (any_dependent_template_arguments_p
19305 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (scope)))))
19308 /* Other types are non-dependent. */
19312 /* Returns TRUE if TYPE is dependent, in the sense of
19313 [temp.dep.type]. Note that a NULL type is considered dependent. */
19316 dependent_type_p (tree type)
19318 /* If there are no template parameters in scope, then there can't be
19319 any dependent types. */
19320 if (!processing_template_decl)
19322 /* If we are not processing a template, then nobody should be
19323 providing us with a dependent type. */
19325 gcc_assert (TREE_CODE (type) != TEMPLATE_TYPE_PARM || is_auto (type));
19329 /* If the type is NULL, we have not computed a type for the entity
19330 in question; in that case, the type is dependent. */
19334 /* Erroneous types can be considered non-dependent. */
19335 if (type == error_mark_node)
19338 /* If we have not already computed the appropriate value for TYPE,
19340 if (!TYPE_DEPENDENT_P_VALID (type))
19342 TYPE_DEPENDENT_P (type) = dependent_type_p_r (type);
19343 TYPE_DEPENDENT_P_VALID (type) = 1;
19346 return TYPE_DEPENDENT_P (type);
19349 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
19350 lookup. In other words, a dependent type that is not the current
19354 dependent_scope_p (tree scope)
19356 return (scope && TYPE_P (scope) && dependent_type_p (scope)
19357 && !currently_open_class (scope));
19360 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
19361 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
19364 /* Note that this predicate is not appropriate for general expressions;
19365 only constant expressions (that satisfy potential_constant_expression)
19366 can be tested for value dependence.
19368 We should really also have a predicate for "instantiation-dependent".
19370 fold_non_dependent_expr: fold if constant and not type-dependent and not value-dependent.
19371 (what about instantiation-dependent constant-expressions?)
19372 is_late_template_attribute: defer if instantiation-dependent.
19373 compute_array_index_type: proceed if constant and not t- or v-dependent
19374 if instantiation-dependent, need to remember full expression
19375 uses_template_parms: FIXME - need to audit callers
19376 tsubst_decl [function_decl]: Why is this using value_dependent_expression_p?
19377 dependent_type_p [array_type]: dependent if index type is dependent
19379 static_assert - instantiation-dependent */
19382 value_dependent_expression_p (tree expression)
19384 if (!processing_template_decl)
19387 /* A name declared with a dependent type. */
19388 if (DECL_P (expression) && type_dependent_expression_p (expression))
19391 switch (TREE_CODE (expression))
19393 case IDENTIFIER_NODE:
19394 /* A name that has not been looked up -- must be dependent. */
19397 case TEMPLATE_PARM_INDEX:
19398 /* A non-type template parm. */
19402 /* A non-type template parm. */
19403 if (DECL_TEMPLATE_PARM_P (expression))
19405 return value_dependent_expression_p (DECL_INITIAL (expression));
19408 /* A constant with literal type and is initialized
19409 with an expression that is value-dependent. */
19410 if (DECL_INITIAL (expression)
19411 && decl_constant_var_p (expression)
19412 && value_dependent_expression_p (DECL_INITIAL (expression)))
19416 case DYNAMIC_CAST_EXPR:
19417 case STATIC_CAST_EXPR:
19418 case CONST_CAST_EXPR:
19419 case REINTERPRET_CAST_EXPR:
19421 /* These expressions are value-dependent if the type to which
19422 the cast occurs is dependent or the expression being casted
19423 is value-dependent. */
19425 tree type = TREE_TYPE (expression);
19427 if (dependent_type_p (type))
19430 /* A functional cast has a list of operands. */
19431 expression = TREE_OPERAND (expression, 0);
19434 /* If there are no operands, it must be an expression such
19435 as "int()". This should not happen for aggregate types
19436 because it would form non-constant expressions. */
19437 gcc_assert (cxx_dialect >= cxx0x
19438 || INTEGRAL_OR_ENUMERATION_TYPE_P (type));
19443 if (TREE_CODE (expression) == TREE_LIST)
19444 return any_value_dependent_elements_p (expression);
19446 return value_dependent_expression_p (expression);
19452 /* A `sizeof' expression is value-dependent if the operand is
19453 type-dependent or is a pack expansion. */
19454 expression = TREE_OPERAND (expression, 0);
19455 if (PACK_EXPANSION_P (expression))
19457 else if (TYPE_P (expression))
19458 return dependent_type_p (expression);
19459 return type_dependent_expression_p (expression);
19461 case AT_ENCODE_EXPR:
19462 /* An 'encode' expression is value-dependent if the operand is
19464 expression = TREE_OPERAND (expression, 0);
19465 return dependent_type_p (expression);
19467 case NOEXCEPT_EXPR:
19468 expression = TREE_OPERAND (expression, 0);
19469 return type_dependent_expression_p (expression);
19473 tree name = TREE_OPERAND (expression, 1);
19474 return value_dependent_expression_p (name);
19477 case COMPONENT_REF:
19478 return (value_dependent_expression_p (TREE_OPERAND (expression, 0))
19479 || value_dependent_expression_p (TREE_OPERAND (expression, 1)));
19481 case NONTYPE_ARGUMENT_PACK:
19482 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
19483 is value-dependent. */
19485 tree values = ARGUMENT_PACK_ARGS (expression);
19486 int i, len = TREE_VEC_LENGTH (values);
19488 for (i = 0; i < len; ++i)
19489 if (value_dependent_expression_p (TREE_VEC_ELT (values, i)))
19497 tree type2 = TRAIT_EXPR_TYPE2 (expression);
19498 return (dependent_type_p (TRAIT_EXPR_TYPE1 (expression))
19499 || (type2 ? dependent_type_p (type2) : false));
19503 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
19504 || (value_dependent_expression_p (TREE_OPERAND (expression, 2))));
19507 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
19508 || (value_dependent_expression_p (TREE_OPERAND (expression, 1))));
19512 tree op = TREE_OPERAND (expression, 0);
19513 return (value_dependent_expression_p (op)
19514 || has_value_dependent_address (op));
19519 tree fn = get_callee_fndecl (expression);
19521 if (!fn && value_dependent_expression_p (CALL_EXPR_FN (expression)))
19523 nargs = call_expr_nargs (expression);
19524 for (i = 0; i < nargs; ++i)
19526 tree op = CALL_EXPR_ARG (expression, i);
19527 /* In a call to a constexpr member function, look through the
19528 implicit ADDR_EXPR on the object argument so that it doesn't
19529 cause the call to be considered value-dependent. We also
19530 look through it in potential_constant_expression. */
19531 if (i == 0 && fn && DECL_DECLARED_CONSTEXPR_P (fn)
19532 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
19533 && TREE_CODE (op) == ADDR_EXPR)
19534 op = TREE_OPERAND (op, 0);
19535 if (value_dependent_expression_p (op))
19541 case TEMPLATE_ID_EXPR:
19542 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
19544 return type_dependent_expression_p (expression);
19550 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), ix, val)
19551 if (value_dependent_expression_p (val))
19557 /* Treat a GNU statement expression as dependent to avoid crashing
19558 under fold_non_dependent_expr; it can't be constant. */
19562 /* A constant expression is value-dependent if any subexpression is
19563 value-dependent. */
19564 switch (TREE_CODE_CLASS (TREE_CODE (expression)))
19566 case tcc_reference:
19568 case tcc_comparison:
19570 case tcc_expression:
19573 int i, len = cp_tree_operand_length (expression);
19575 for (i = 0; i < len; i++)
19577 tree t = TREE_OPERAND (expression, i);
19579 /* In some cases, some of the operands may be missing.l
19580 (For example, in the case of PREDECREMENT_EXPR, the
19581 amount to increment by may be missing.) That doesn't
19582 make the expression dependent. */
19583 if (t && value_dependent_expression_p (t))
19594 /* The expression is not value-dependent. */
19598 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
19599 [temp.dep.expr]. Note that an expression with no type is
19600 considered dependent. Other parts of the compiler arrange for an
19601 expression with type-dependent subexpressions to have no type, so
19602 this function doesn't have to be fully recursive. */
19605 type_dependent_expression_p (tree expression)
19607 if (!processing_template_decl)
19610 if (expression == error_mark_node)
19613 /* An unresolved name is always dependent. */
19614 if (TREE_CODE (expression) == IDENTIFIER_NODE
19615 || TREE_CODE (expression) == USING_DECL)
19618 /* Some expression forms are never type-dependent. */
19619 if (TREE_CODE (expression) == PSEUDO_DTOR_EXPR
19620 || TREE_CODE (expression) == SIZEOF_EXPR
19621 || TREE_CODE (expression) == ALIGNOF_EXPR
19622 || TREE_CODE (expression) == AT_ENCODE_EXPR
19623 || TREE_CODE (expression) == NOEXCEPT_EXPR
19624 || TREE_CODE (expression) == TRAIT_EXPR
19625 || TREE_CODE (expression) == TYPEID_EXPR
19626 || TREE_CODE (expression) == DELETE_EXPR
19627 || TREE_CODE (expression) == VEC_DELETE_EXPR
19628 || TREE_CODE (expression) == THROW_EXPR)
19631 /* The types of these expressions depends only on the type to which
19632 the cast occurs. */
19633 if (TREE_CODE (expression) == DYNAMIC_CAST_EXPR
19634 || TREE_CODE (expression) == STATIC_CAST_EXPR
19635 || TREE_CODE (expression) == CONST_CAST_EXPR
19636 || TREE_CODE (expression) == REINTERPRET_CAST_EXPR
19637 || TREE_CODE (expression) == IMPLICIT_CONV_EXPR
19638 || TREE_CODE (expression) == CAST_EXPR)
19639 return dependent_type_p (TREE_TYPE (expression));
19641 /* The types of these expressions depends only on the type created
19642 by the expression. */
19643 if (TREE_CODE (expression) == NEW_EXPR
19644 || TREE_CODE (expression) == VEC_NEW_EXPR)
19646 /* For NEW_EXPR tree nodes created inside a template, either
19647 the object type itself or a TREE_LIST may appear as the
19649 tree type = TREE_OPERAND (expression, 1);
19650 if (TREE_CODE (type) == TREE_LIST)
19651 /* This is an array type. We need to check array dimensions
19653 return dependent_type_p (TREE_VALUE (TREE_PURPOSE (type)))
19654 || value_dependent_expression_p
19655 (TREE_OPERAND (TREE_VALUE (type), 1));
19657 return dependent_type_p (type);
19660 if (TREE_CODE (expression) == SCOPE_REF)
19662 tree scope = TREE_OPERAND (expression, 0);
19663 tree name = TREE_OPERAND (expression, 1);
19665 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
19666 contains an identifier associated by name lookup with one or more
19667 declarations declared with a dependent type, or...a
19668 nested-name-specifier or qualified-id that names a member of an
19669 unknown specialization. */
19670 return (type_dependent_expression_p (name)
19671 || dependent_scope_p (scope));
19674 if (TREE_CODE (expression) == FUNCTION_DECL
19675 && DECL_LANG_SPECIFIC (expression)
19676 && DECL_TEMPLATE_INFO (expression)
19677 && (any_dependent_template_arguments_p
19678 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (expression)))))
19681 if (TREE_CODE (expression) == TEMPLATE_DECL
19682 && !DECL_TEMPLATE_TEMPLATE_PARM_P (expression))
19685 if (TREE_CODE (expression) == STMT_EXPR)
19686 expression = stmt_expr_value_expr (expression);
19688 if (BRACE_ENCLOSED_INITIALIZER_P (expression))
19693 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), i, elt)
19695 if (type_dependent_expression_p (elt))
19701 /* A static data member of the current instantiation with incomplete
19702 array type is type-dependent, as the definition and specializations
19703 can have different bounds. */
19704 if (TREE_CODE (expression) == VAR_DECL
19705 && DECL_CLASS_SCOPE_P (expression)
19706 && dependent_type_p (DECL_CONTEXT (expression))
19707 && VAR_HAD_UNKNOWN_BOUND (expression))
19710 if (TREE_TYPE (expression) == unknown_type_node)
19712 if (TREE_CODE (expression) == ADDR_EXPR)
19713 return type_dependent_expression_p (TREE_OPERAND (expression, 0));
19714 if (TREE_CODE (expression) == COMPONENT_REF
19715 || TREE_CODE (expression) == OFFSET_REF)
19717 if (type_dependent_expression_p (TREE_OPERAND (expression, 0)))
19719 expression = TREE_OPERAND (expression, 1);
19720 if (TREE_CODE (expression) == IDENTIFIER_NODE)
19723 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
19724 if (TREE_CODE (expression) == SCOPE_REF)
19727 if (BASELINK_P (expression))
19728 expression = BASELINK_FUNCTIONS (expression);
19730 if (TREE_CODE (expression) == TEMPLATE_ID_EXPR)
19732 if (any_dependent_template_arguments_p
19733 (TREE_OPERAND (expression, 1)))
19735 expression = TREE_OPERAND (expression, 0);
19737 gcc_assert (TREE_CODE (expression) == OVERLOAD
19738 || TREE_CODE (expression) == FUNCTION_DECL);
19742 if (type_dependent_expression_p (OVL_CURRENT (expression)))
19744 expression = OVL_NEXT (expression);
19749 gcc_assert (TREE_CODE (expression) != TYPE_DECL);
19751 return (dependent_type_p (TREE_TYPE (expression)));
19754 /* Like type_dependent_expression_p, but it also works while not processing
19755 a template definition, i.e. during substitution or mangling. */
19758 type_dependent_expression_p_push (tree expr)
19761 ++processing_template_decl;
19762 b = type_dependent_expression_p (expr);
19763 --processing_template_decl;
19767 /* Returns TRUE if ARGS contains a type-dependent expression. */
19770 any_type_dependent_arguments_p (const VEC(tree,gc) *args)
19775 FOR_EACH_VEC_ELT (tree, args, i, arg)
19777 if (type_dependent_expression_p (arg))
19783 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
19784 expressions) contains any type-dependent expressions. */
19787 any_type_dependent_elements_p (const_tree list)
19789 for (; list; list = TREE_CHAIN (list))
19790 if (value_dependent_expression_p (TREE_VALUE (list)))
19796 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
19797 expressions) contains any value-dependent expressions. */
19800 any_value_dependent_elements_p (const_tree list)
19802 for (; list; list = TREE_CHAIN (list))
19803 if (value_dependent_expression_p (TREE_VALUE (list)))
19809 /* Returns TRUE if the ARG (a template argument) is dependent. */
19812 dependent_template_arg_p (tree arg)
19814 if (!processing_template_decl)
19817 /* Assume a template argument that was wrongly written by the user
19818 is dependent. This is consistent with what
19819 any_dependent_template_arguments_p [that calls this function]
19821 if (!arg || arg == error_mark_node)
19824 if (TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
19825 arg = ARGUMENT_PACK_SELECT_ARG (arg);
19827 if (TREE_CODE (arg) == TEMPLATE_DECL
19828 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
19829 return dependent_template_p (arg);
19830 else if (ARGUMENT_PACK_P (arg))
19832 tree args = ARGUMENT_PACK_ARGS (arg);
19833 int i, len = TREE_VEC_LENGTH (args);
19834 for (i = 0; i < len; ++i)
19836 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
19842 else if (TYPE_P (arg))
19843 return dependent_type_p (arg);
19845 return (type_dependent_expression_p (arg)
19846 || value_dependent_expression_p (arg));
19849 /* Returns true if ARGS (a collection of template arguments) contains
19850 any types that require structural equality testing. */
19853 any_template_arguments_need_structural_equality_p (tree args)
19860 if (args == error_mark_node)
19863 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
19865 tree level = TMPL_ARGS_LEVEL (args, i + 1);
19866 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
19868 tree arg = TREE_VEC_ELT (level, j);
19869 tree packed_args = NULL_TREE;
19872 if (ARGUMENT_PACK_P (arg))
19874 /* Look inside the argument pack. */
19875 packed_args = ARGUMENT_PACK_ARGS (arg);
19876 len = TREE_VEC_LENGTH (packed_args);
19879 for (k = 0; k < len; ++k)
19882 arg = TREE_VEC_ELT (packed_args, k);
19884 if (error_operand_p (arg))
19886 else if (TREE_CODE (arg) == TEMPLATE_DECL
19887 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
19889 else if (TYPE_P (arg) && TYPE_STRUCTURAL_EQUALITY_P (arg))
19891 else if (!TYPE_P (arg) && TREE_TYPE (arg)
19892 && TYPE_STRUCTURAL_EQUALITY_P (TREE_TYPE (arg)))
19901 /* Returns true if ARGS (a collection of template arguments) contains
19902 any dependent arguments. */
19905 any_dependent_template_arguments_p (const_tree args)
19912 if (args == error_mark_node)
19915 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
19917 const_tree level = TMPL_ARGS_LEVEL (args, i + 1);
19918 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
19919 if (dependent_template_arg_p (TREE_VEC_ELT (level, j)))
19926 /* Returns TRUE if the template TMPL is dependent. */
19929 dependent_template_p (tree tmpl)
19931 if (TREE_CODE (tmpl) == OVERLOAD)
19935 if (dependent_template_p (OVL_CURRENT (tmpl)))
19937 tmpl = OVL_NEXT (tmpl);
19942 /* Template template parameters are dependent. */
19943 if (DECL_TEMPLATE_TEMPLATE_PARM_P (tmpl)
19944 || TREE_CODE (tmpl) == TEMPLATE_TEMPLATE_PARM)
19946 /* So are names that have not been looked up. */
19947 if (TREE_CODE (tmpl) == SCOPE_REF
19948 || TREE_CODE (tmpl) == IDENTIFIER_NODE)
19950 /* So are member templates of dependent classes. */
19951 if (TYPE_P (CP_DECL_CONTEXT (tmpl)))
19952 return dependent_type_p (DECL_CONTEXT (tmpl));
19956 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
19959 dependent_template_id_p (tree tmpl, tree args)
19961 return (dependent_template_p (tmpl)
19962 || any_dependent_template_arguments_p (args));
19965 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
19969 dependent_omp_for_p (tree declv, tree initv, tree condv, tree incrv)
19973 if (!processing_template_decl)
19976 for (i = 0; i < TREE_VEC_LENGTH (declv); i++)
19978 tree decl = TREE_VEC_ELT (declv, i);
19979 tree init = TREE_VEC_ELT (initv, i);
19980 tree cond = TREE_VEC_ELT (condv, i);
19981 tree incr = TREE_VEC_ELT (incrv, i);
19983 if (type_dependent_expression_p (decl))
19986 if (init && type_dependent_expression_p (init))
19989 if (type_dependent_expression_p (cond))
19992 if (COMPARISON_CLASS_P (cond)
19993 && (type_dependent_expression_p (TREE_OPERAND (cond, 0))
19994 || type_dependent_expression_p (TREE_OPERAND (cond, 1))))
19997 if (TREE_CODE (incr) == MODOP_EXPR)
19999 if (type_dependent_expression_p (TREE_OPERAND (incr, 0))
20000 || type_dependent_expression_p (TREE_OPERAND (incr, 2)))
20003 else if (type_dependent_expression_p (incr))
20005 else if (TREE_CODE (incr) == MODIFY_EXPR)
20007 if (type_dependent_expression_p (TREE_OPERAND (incr, 0)))
20009 else if (BINARY_CLASS_P (TREE_OPERAND (incr, 1)))
20011 tree t = TREE_OPERAND (incr, 1);
20012 if (type_dependent_expression_p (TREE_OPERAND (t, 0))
20013 || type_dependent_expression_p (TREE_OPERAND (t, 1)))
20022 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
20023 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
20024 no such TYPE can be found. Note that this function peers inside
20025 uninstantiated templates and therefore should be used only in
20026 extremely limited situations. ONLY_CURRENT_P restricts this
20027 peering to the currently open classes hierarchy (which is required
20028 when comparing types). */
20031 resolve_typename_type (tree type, bool only_current_p)
20040 gcc_assert (TREE_CODE (type) == TYPENAME_TYPE);
20042 scope = TYPE_CONTEXT (type);
20043 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
20044 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
20045 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
20046 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
20047 identifier of the TYPENAME_TYPE anymore.
20048 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
20049 TYPENAME_TYPE instead, we avoid messing up with a possible
20050 typedef variant case. */
20051 name = TYPE_IDENTIFIER (TYPE_MAIN_VARIANT (type));
20053 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
20054 it first before we can figure out what NAME refers to. */
20055 if (TREE_CODE (scope) == TYPENAME_TYPE)
20056 scope = resolve_typename_type (scope, only_current_p);
20057 /* If we don't know what SCOPE refers to, then we cannot resolve the
20059 if (TREE_CODE (scope) == TYPENAME_TYPE)
20061 /* If the SCOPE is a template type parameter, we have no way of
20062 resolving the name. */
20063 if (TREE_CODE (scope) == TEMPLATE_TYPE_PARM)
20065 /* If the SCOPE is not the current instantiation, there's no reason
20066 to look inside it. */
20067 if (only_current_p && !currently_open_class (scope))
20069 /* If this is a typedef, we don't want to look inside (c++/11987). */
20070 if (typedef_variant_p (type))
20072 /* If SCOPE isn't the template itself, it will not have a valid
20073 TYPE_FIELDS list. */
20074 if (same_type_p (scope, CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope)))
20075 /* scope is either the template itself or a compatible instantiation
20076 like X<T>, so look up the name in the original template. */
20077 scope = CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope);
20079 /* scope is a partial instantiation, so we can't do the lookup or we
20080 will lose the template arguments. */
20082 /* Enter the SCOPE so that name lookup will be resolved as if we
20083 were in the class definition. In particular, SCOPE will no
20084 longer be considered a dependent type. */
20085 pushed_scope = push_scope (scope);
20086 /* Look up the declaration. */
20087 decl = lookup_member (scope, name, /*protect=*/0, /*want_type=*/true,
20088 tf_warning_or_error);
20090 result = NULL_TREE;
20092 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
20093 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
20096 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == IDENTIFIER_NODE
20097 && TREE_CODE (decl) == TYPE_DECL)
20099 result = TREE_TYPE (decl);
20100 if (result == error_mark_node)
20101 result = NULL_TREE;
20103 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == TEMPLATE_ID_EXPR
20104 && DECL_CLASS_TEMPLATE_P (decl))
20108 /* Obtain the template and the arguments. */
20109 tmpl = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 0);
20110 args = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 1);
20111 /* Instantiate the template. */
20112 result = lookup_template_class (tmpl, args, NULL_TREE, NULL_TREE,
20113 /*entering_scope=*/0,
20114 tf_error | tf_user);
20115 if (result == error_mark_node)
20116 result = NULL_TREE;
20119 /* Leave the SCOPE. */
20121 pop_scope (pushed_scope);
20123 /* If we failed to resolve it, return the original typename. */
20127 /* If lookup found a typename type, resolve that too. */
20128 if (TREE_CODE (result) == TYPENAME_TYPE && !TYPENAME_IS_RESOLVING_P (result))
20130 /* Ill-formed programs can cause infinite recursion here, so we
20131 must catch that. */
20132 TYPENAME_IS_RESOLVING_P (type) = 1;
20133 result = resolve_typename_type (result, only_current_p);
20134 TYPENAME_IS_RESOLVING_P (type) = 0;
20137 /* Qualify the resulting type. */
20138 quals = cp_type_quals (type);
20140 result = cp_build_qualified_type (result, cp_type_quals (result) | quals);
20145 /* EXPR is an expression which is not type-dependent. Return a proxy
20146 for EXPR that can be used to compute the types of larger
20147 expressions containing EXPR. */
20150 build_non_dependent_expr (tree expr)
20154 #ifdef ENABLE_CHECKING
20155 /* Try to get a constant value for all non-type-dependent expressions in
20156 order to expose bugs in *_dependent_expression_p and constexpr. */
20157 if (cxx_dialect >= cxx0x)
20158 maybe_constant_value (fold_non_dependent_expr_sfinae (expr, tf_none));
20161 /* Preserve OVERLOADs; the functions must be available to resolve
20164 if (TREE_CODE (inner_expr) == STMT_EXPR)
20165 inner_expr = stmt_expr_value_expr (inner_expr);
20166 if (TREE_CODE (inner_expr) == ADDR_EXPR)
20167 inner_expr = TREE_OPERAND (inner_expr, 0);
20168 if (TREE_CODE (inner_expr) == COMPONENT_REF)
20169 inner_expr = TREE_OPERAND (inner_expr, 1);
20170 if (is_overloaded_fn (inner_expr)
20171 || TREE_CODE (inner_expr) == OFFSET_REF)
20173 /* There is no need to return a proxy for a variable. */
20174 if (TREE_CODE (expr) == VAR_DECL)
20176 /* Preserve string constants; conversions from string constants to
20177 "char *" are allowed, even though normally a "const char *"
20178 cannot be used to initialize a "char *". */
20179 if (TREE_CODE (expr) == STRING_CST)
20181 /* Preserve arithmetic constants, as an optimization -- there is no
20182 reason to create a new node. */
20183 if (TREE_CODE (expr) == INTEGER_CST || TREE_CODE (expr) == REAL_CST)
20185 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
20186 There is at least one place where we want to know that a
20187 particular expression is a throw-expression: when checking a ?:
20188 expression, there are special rules if the second or third
20189 argument is a throw-expression. */
20190 if (TREE_CODE (expr) == THROW_EXPR)
20193 /* Don't wrap an initializer list, we need to be able to look inside. */
20194 if (BRACE_ENCLOSED_INITIALIZER_P (expr))
20197 if (TREE_CODE (expr) == COND_EXPR)
20198 return build3 (COND_EXPR,
20200 TREE_OPERAND (expr, 0),
20201 (TREE_OPERAND (expr, 1)
20202 ? build_non_dependent_expr (TREE_OPERAND (expr, 1))
20203 : build_non_dependent_expr (TREE_OPERAND (expr, 0))),
20204 build_non_dependent_expr (TREE_OPERAND (expr, 2)));
20205 if (TREE_CODE (expr) == COMPOUND_EXPR
20206 && !COMPOUND_EXPR_OVERLOADED (expr))
20207 return build2 (COMPOUND_EXPR,
20209 TREE_OPERAND (expr, 0),
20210 build_non_dependent_expr (TREE_OPERAND (expr, 1)));
20212 /* If the type is unknown, it can't really be non-dependent */
20213 gcc_assert (TREE_TYPE (expr) != unknown_type_node);
20215 /* Otherwise, build a NON_DEPENDENT_EXPR. */
20216 return build1 (NON_DEPENDENT_EXPR, TREE_TYPE (expr), expr);
20219 /* ARGS is a vector of expressions as arguments to a function call.
20220 Replace the arguments with equivalent non-dependent expressions.
20221 This modifies ARGS in place. */
20224 make_args_non_dependent (VEC(tree,gc) *args)
20229 FOR_EACH_VEC_ELT (tree, args, ix, arg)
20231 tree newarg = build_non_dependent_expr (arg);
20233 VEC_replace (tree, args, ix, newarg);
20237 /* Returns a type which represents 'auto'. We use a TEMPLATE_TYPE_PARM
20238 with a level one deeper than the actual template parms. */
20243 tree au = cxx_make_type (TEMPLATE_TYPE_PARM);
20244 TYPE_NAME (au) = build_decl (BUILTINS_LOCATION,
20245 TYPE_DECL, get_identifier ("auto"), au);
20246 TYPE_STUB_DECL (au) = TYPE_NAME (au);
20247 TEMPLATE_TYPE_PARM_INDEX (au) = build_template_parm_index
20248 (0, processing_template_decl + 1, processing_template_decl + 1,
20249 0, TYPE_NAME (au), NULL_TREE);
20250 TYPE_CANONICAL (au) = canonical_type_parameter (au);
20251 DECL_ARTIFICIAL (TYPE_NAME (au)) = 1;
20252 SET_DECL_TEMPLATE_PARM_P (TYPE_NAME (au));
20257 /* Given type ARG, return std::initializer_list<ARG>. */
20262 tree std_init_list = namespace_binding
20263 (get_identifier ("initializer_list"), std_node);
20265 if (!std_init_list || !DECL_CLASS_TEMPLATE_P (std_init_list))
20267 error ("deducing from brace-enclosed initializer list requires "
20268 "#include <initializer_list>");
20269 return error_mark_node;
20271 argvec = make_tree_vec (1);
20272 TREE_VEC_ELT (argvec, 0) = arg;
20273 return lookup_template_class (std_init_list, argvec, NULL_TREE,
20274 NULL_TREE, 0, tf_warning_or_error);
20277 /* Replace auto in TYPE with std::initializer_list<auto>. */
20280 listify_autos (tree type, tree auto_node)
20282 tree init_auto = listify (auto_node);
20283 tree argvec = make_tree_vec (1);
20284 TREE_VEC_ELT (argvec, 0) = init_auto;
20285 if (processing_template_decl)
20286 argvec = add_to_template_args (current_template_args (), argvec);
20287 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
20290 /* walk_tree helper for do_auto_deduction. */
20293 contains_auto_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
20296 /* Is this a variable with the type we're looking for? */
20298 && TREE_TYPE (*tp) == type)
20304 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
20305 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
20308 do_auto_deduction (tree type, tree init, tree auto_node)
20310 tree parms, tparms, targs;
20315 if (processing_template_decl
20316 && (TREE_TYPE (init) == NULL_TREE
20317 || BRACE_ENCLOSED_INITIALIZER_P (init)))
20318 /* Not enough information to try this yet. */
20321 /* The name of the object being declared shall not appear in the
20322 initializer expression. */
20323 decl = cp_walk_tree_without_duplicates (&init, contains_auto_r, type);
20326 error ("variable %q#D with %<auto%> type used in its own "
20327 "initializer", decl);
20328 return error_mark_node;
20331 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
20332 with either a new invented type template parameter U or, if the
20333 initializer is a braced-init-list (8.5.4), with
20334 std::initializer_list<U>. */
20335 if (BRACE_ENCLOSED_INITIALIZER_P (init))
20336 type = listify_autos (type, auto_node);
20338 init = resolve_nondeduced_context (init);
20340 parms = build_tree_list (NULL_TREE, type);
20342 tparms = make_tree_vec (1);
20343 targs = make_tree_vec (1);
20344 TREE_VEC_ELT (tparms, 0)
20345 = build_tree_list (NULL_TREE, TYPE_NAME (auto_node));
20346 val = type_unification_real (tparms, targs, parms, args, 1, 0,
20347 DEDUCE_CALL, LOOKUP_NORMAL,
20348 /*explain_p=*/false);
20351 if (processing_template_decl)
20352 /* Try again at instantiation time. */
20354 if (type && type != error_mark_node)
20355 /* If type is error_mark_node a diagnostic must have been
20356 emitted by now. Also, having a mention to '<type error>'
20357 in the diagnostic is not really useful to the user. */
20358 error ("unable to deduce %qT from %qE", type, init);
20359 return error_mark_node;
20362 /* If the list of declarators contains more than one declarator, the type
20363 of each declared variable is determined as described above. If the
20364 type deduced for the template parameter U is not the same in each
20365 deduction, the program is ill-formed. */
20366 if (TREE_TYPE (auto_node)
20367 && !same_type_p (TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0)))
20369 error ("inconsistent deduction for %qT: %qT and then %qT",
20370 auto_node, TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0));
20371 return error_mark_node;
20373 TREE_TYPE (auto_node) = TREE_VEC_ELT (targs, 0);
20375 if (processing_template_decl)
20376 targs = add_to_template_args (current_template_args (), targs);
20377 return tsubst (type, targs, tf_warning_or_error, NULL_TREE);
20380 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
20384 splice_late_return_type (tree type, tree late_return_type)
20388 if (late_return_type == NULL_TREE)
20390 argvec = make_tree_vec (1);
20391 TREE_VEC_ELT (argvec, 0) = late_return_type;
20392 if (processing_template_parmlist)
20393 /* For a late-specified return type in a template type-parameter, we
20394 need to add a dummy argument level for its parmlist. */
20395 argvec = add_to_template_args
20396 (make_tree_vec (processing_template_parmlist), argvec);
20397 if (current_template_parms)
20398 argvec = add_to_template_args (current_template_args (), argvec);
20399 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
20402 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto'. */
20405 is_auto (const_tree type)
20407 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
20408 && TYPE_IDENTIFIER (type) == get_identifier ("auto"))
20414 /* Returns true iff TYPE contains a use of 'auto'. Since auto can only
20415 appear as a type-specifier for the declaration in question, we don't
20416 have to look through the whole type. */
20419 type_uses_auto (tree type)
20421 enum tree_code code;
20422 if (is_auto (type))
20425 code = TREE_CODE (type);
20427 if (code == POINTER_TYPE || code == REFERENCE_TYPE
20428 || code == OFFSET_TYPE || code == FUNCTION_TYPE
20429 || code == METHOD_TYPE || code == ARRAY_TYPE)
20430 return type_uses_auto (TREE_TYPE (type));
20432 if (TYPE_PTRMEMFUNC_P (type))
20433 return type_uses_auto (TREE_TYPE (TREE_TYPE
20434 (TYPE_PTRMEMFUNC_FN_TYPE (type))));
20439 /* For a given template T, return the vector of typedefs referenced
20440 in T for which access check is needed at T instantiation time.
20441 T is either a FUNCTION_DECL or a RECORD_TYPE.
20442 Those typedefs were added to T by the function
20443 append_type_to_template_for_access_check. */
20445 VEC(qualified_typedef_usage_t,gc)*
20446 get_types_needing_access_check (tree t)
20449 VEC(qualified_typedef_usage_t,gc) *result = NULL;
20451 if (!t || t == error_mark_node)
20454 if (!(ti = get_template_info (t)))
20457 if (CLASS_TYPE_P (t)
20458 || TREE_CODE (t) == FUNCTION_DECL)
20460 if (!TI_TEMPLATE (ti))
20463 result = TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti);
20469 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
20470 tied to T. That list of typedefs will be access checked at
20471 T instantiation time.
20472 T is either a FUNCTION_DECL or a RECORD_TYPE.
20473 TYPE_DECL is a TYPE_DECL node representing a typedef.
20474 SCOPE is the scope through which TYPE_DECL is accessed.
20475 LOCATION is the location of the usage point of TYPE_DECL.
20477 This function is a subroutine of
20478 append_type_to_template_for_access_check. */
20481 append_type_to_template_for_access_check_1 (tree t,
20484 location_t location)
20486 qualified_typedef_usage_t typedef_usage;
20489 if (!t || t == error_mark_node)
20492 gcc_assert ((TREE_CODE (t) == FUNCTION_DECL
20493 || CLASS_TYPE_P (t))
20495 && TREE_CODE (type_decl) == TYPE_DECL
20498 if (!(ti = get_template_info (t)))
20501 gcc_assert (TI_TEMPLATE (ti));
20503 typedef_usage.typedef_decl = type_decl;
20504 typedef_usage.context = scope;
20505 typedef_usage.locus = location;
20507 VEC_safe_push (qualified_typedef_usage_t, gc,
20508 TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti),
20512 /* Append TYPE_DECL to the template TEMPL.
20513 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
20514 At TEMPL instanciation time, TYPE_DECL will be checked to see
20515 if it can be accessed through SCOPE.
20516 LOCATION is the location of the usage point of TYPE_DECL.
20518 e.g. consider the following code snippet:
20525 template<class U> struct S
20527 C::myint mi; // <-- usage point of the typedef C::myint
20532 At S<char> instantiation time, we need to check the access of C::myint
20533 In other words, we need to check the access of the myint typedef through
20534 the C scope. For that purpose, this function will add the myint typedef
20535 and the scope C through which its being accessed to a list of typedefs
20536 tied to the template S. That list will be walked at template instantiation
20537 time and access check performed on each typedefs it contains.
20538 Note that this particular code snippet should yield an error because
20539 myint is private to C. */
20542 append_type_to_template_for_access_check (tree templ,
20545 location_t location)
20547 qualified_typedef_usage_t *iter;
20550 gcc_assert (type_decl && (TREE_CODE (type_decl) == TYPE_DECL));
20552 /* Make sure we don't append the type to the template twice. */
20553 FOR_EACH_VEC_ELT (qualified_typedef_usage_t,
20554 get_types_needing_access_check (templ),
20556 if (iter->typedef_decl == type_decl && scope == iter->context)
20559 append_type_to_template_for_access_check_1 (templ, type_decl,
20563 /* Set up the hash tables for template instantiations. */
20566 init_template_processing (void)
20568 decl_specializations = htab_create_ggc (37,
20569 hash_specialization,
20570 eq_specializations,
20572 type_specializations = htab_create_ggc (37,
20573 hash_specialization,
20574 eq_specializations,
20578 /* Print stats about the template hash tables for -fstats. */
20581 print_template_statistics (void)
20583 fprintf (stderr, "decl_specializations: size %ld, %ld elements, "
20584 "%f collisions\n", (long) htab_size (decl_specializations),
20585 (long) htab_elements (decl_specializations),
20586 htab_collisions (decl_specializations));
20587 fprintf (stderr, "type_specializations: size %ld, %ld elements, "
20588 "%f collisions\n", (long) htab_size (type_specializations),
20589 (long) htab_elements (type_specializations),
20590 htab_collisions (type_specializations));
20593 #include "gt-cp-pt.h"