1 /* Handle parameterized types (templates) for GNU C++.
2 Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
3 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010, 2011
4 Free Software Foundation, Inc.
5 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
6 Rewritten by Jason Merrill (jason@cygnus.com).
8 This file is part of GCC.
10 GCC is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3, or (at your option)
15 GCC is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with GCC; see the file COPYING3. If not see
22 <http://www.gnu.org/licenses/>. */
24 /* Known bugs or deficiencies include:
26 all methods must be provided in header files; can't use a source
27 file that contains only the method templates and "just win". */
31 #include "coretypes.h"
35 #include "pointer-set.h"
38 #include "c-family/c-common.h"
39 #include "c-family/c-objc.h"
40 #include "cp-objcp-common.h"
41 #include "tree-inline.h"
46 #include "tree-iterator.h"
49 /* The type of functions taking a tree, and some additional data, and
51 typedef int (*tree_fn_t) (tree, void*);
53 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
54 instantiations have been deferred, either because their definitions
55 were not yet available, or because we were putting off doing the work. */
56 struct GTY ((chain_next ("%h.next"))) pending_template {
57 struct pending_template *next;
58 struct tinst_level *tinst;
61 static GTY(()) struct pending_template *pending_templates;
62 static GTY(()) struct pending_template *last_pending_template;
64 int processing_template_parmlist;
65 static int template_header_count;
67 static GTY(()) tree saved_trees;
68 static VEC(int,heap) *inline_parm_levels;
70 static GTY(()) struct tinst_level *current_tinst_level;
72 static GTY(()) tree saved_access_scope;
74 /* Live only within one (recursive) call to tsubst_expr. We use
75 this to pass the statement expression node from the STMT_EXPR
76 to the EXPR_STMT that is its result. */
77 static tree cur_stmt_expr;
79 /* A map from local variable declarations in the body of the template
80 presently being instantiated to the corresponding instantiated
82 static htab_t local_specializations;
84 typedef struct GTY(()) spec_entry
91 static GTY ((param_is (spec_entry)))
92 htab_t decl_specializations;
94 static GTY ((param_is (spec_entry)))
95 htab_t type_specializations;
97 /* Contains canonical template parameter types. The vector is indexed by
98 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
99 TREE_LIST, whose TREE_VALUEs contain the canonical template
100 parameters of various types and levels. */
101 static GTY(()) VEC(tree,gc) *canonical_template_parms;
103 #define UNIFY_ALLOW_NONE 0
104 #define UNIFY_ALLOW_MORE_CV_QUAL 1
105 #define UNIFY_ALLOW_LESS_CV_QUAL 2
106 #define UNIFY_ALLOW_DERIVED 4
107 #define UNIFY_ALLOW_INTEGER 8
108 #define UNIFY_ALLOW_OUTER_LEVEL 16
109 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
110 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
112 static void push_access_scope (tree);
113 static void pop_access_scope (tree);
114 static void push_deduction_access_scope (tree);
115 static void pop_deduction_access_scope (tree);
116 static bool resolve_overloaded_unification (tree, tree, tree, tree,
117 unification_kind_t, int);
118 static int try_one_overload (tree, tree, tree, tree, tree,
119 unification_kind_t, int, bool);
120 static int unify (tree, tree, tree, tree, int);
121 static void add_pending_template (tree);
122 static tree reopen_tinst_level (struct tinst_level *);
123 static tree tsubst_initializer_list (tree, tree);
124 static tree get_class_bindings (tree, tree, tree);
125 static tree coerce_template_parms (tree, tree, tree, tsubst_flags_t,
127 static void tsubst_enum (tree, tree, tree);
128 static tree add_to_template_args (tree, tree);
129 static tree add_outermost_template_args (tree, tree);
130 static bool check_instantiated_args (tree, tree, tsubst_flags_t);
131 static int maybe_adjust_types_for_deduction (unification_kind_t, tree*, tree*,
133 static int type_unification_real (tree, tree, tree, const tree *,
134 unsigned int, int, unification_kind_t, int);
135 static void note_template_header (int);
136 static tree convert_nontype_argument_function (tree, tree);
137 static tree convert_nontype_argument (tree, tree, tsubst_flags_t);
138 static tree convert_template_argument (tree, tree, tree,
139 tsubst_flags_t, int, tree);
140 static int for_each_template_parm (tree, tree_fn_t, void*,
141 struct pointer_set_t*, bool);
142 static tree expand_template_argument_pack (tree);
143 static tree build_template_parm_index (int, int, int, int, tree, tree);
144 static bool inline_needs_template_parms (tree);
145 static void push_inline_template_parms_recursive (tree, int);
146 static tree retrieve_local_specialization (tree);
147 static void register_local_specialization (tree, tree);
148 static hashval_t hash_specialization (const void *p);
149 static tree reduce_template_parm_level (tree, tree, int, tree, tsubst_flags_t);
150 static int mark_template_parm (tree, void *);
151 static int template_parm_this_level_p (tree, void *);
152 static tree tsubst_friend_function (tree, tree);
153 static tree tsubst_friend_class (tree, tree);
154 static int can_complete_type_without_circularity (tree);
155 static tree get_bindings (tree, tree, tree, bool);
156 static int template_decl_level (tree);
157 static int check_cv_quals_for_unify (int, tree, tree);
158 static void template_parm_level_and_index (tree, int*, int*);
159 static int unify_pack_expansion (tree, tree, tree, tree, int, bool, bool);
160 static tree tsubst_template_arg (tree, tree, tsubst_flags_t, tree);
161 static tree tsubst_template_args (tree, tree, tsubst_flags_t, tree);
162 static tree tsubst_template_parms (tree, tree, tsubst_flags_t);
163 static void regenerate_decl_from_template (tree, tree);
164 static tree most_specialized_class (tree, tree, tsubst_flags_t);
165 static tree tsubst_aggr_type (tree, tree, tsubst_flags_t, tree, int);
166 static tree tsubst_arg_types (tree, tree, tsubst_flags_t, tree);
167 static tree tsubst_function_type (tree, tree, tsubst_flags_t, tree);
168 static bool check_specialization_scope (void);
169 static tree process_partial_specialization (tree);
170 static void set_current_access_from_decl (tree);
171 static tree get_template_base (tree, tree, tree, tree);
172 static tree try_class_unification (tree, tree, tree, tree);
173 static int coerce_template_template_parms (tree, tree, tsubst_flags_t,
175 static bool template_template_parm_bindings_ok_p (tree, tree);
176 static int template_args_equal (tree, tree);
177 static void tsubst_default_arguments (tree);
178 static tree for_each_template_parm_r (tree *, int *, void *);
179 static tree copy_default_args_to_explicit_spec_1 (tree, tree);
180 static void copy_default_args_to_explicit_spec (tree);
181 static int invalid_nontype_parm_type_p (tree, tsubst_flags_t);
182 static int eq_local_specializations (const void *, const void *);
183 static bool dependent_template_arg_p (tree);
184 static bool any_template_arguments_need_structural_equality_p (tree);
185 static bool dependent_type_p_r (tree);
186 static tree tsubst_expr (tree, tree, tsubst_flags_t, tree, bool);
187 static tree tsubst_copy (tree, tree, tsubst_flags_t, tree);
188 static tree tsubst_pack_expansion (tree, tree, tsubst_flags_t, tree);
189 static tree tsubst_decl (tree, tree, tsubst_flags_t);
190 static void perform_typedefs_access_check (tree tmpl, tree targs);
191 static void append_type_to_template_for_access_check_1 (tree, tree, tree,
193 static tree listify (tree);
194 static tree listify_autos (tree, tree);
195 static tree template_parm_to_arg (tree t);
196 static tree current_template_args (void);
197 static tree fixup_template_type_parm_type (tree, int);
198 static tree fixup_template_parm_index (tree, tree, int);
199 static tree tsubst_template_parm (tree, tree, tsubst_flags_t);
201 /* Make the current scope suitable for access checking when we are
202 processing T. T can be FUNCTION_DECL for instantiated function
203 template, or VAR_DECL for static member variable (need by
204 instantiate_decl). */
207 push_access_scope (tree t)
209 gcc_assert (TREE_CODE (t) == FUNCTION_DECL
210 || TREE_CODE (t) == VAR_DECL);
212 if (DECL_FRIEND_CONTEXT (t))
213 push_nested_class (DECL_FRIEND_CONTEXT (t));
214 else if (DECL_CLASS_SCOPE_P (t))
215 push_nested_class (DECL_CONTEXT (t));
217 pushclass (NULL_TREE);
219 if (TREE_CODE (t) == FUNCTION_DECL)
221 saved_access_scope = tree_cons
222 (NULL_TREE, current_function_decl, saved_access_scope);
223 current_function_decl = t;
227 /* Restore the scope set up by push_access_scope. T is the node we
231 pop_access_scope (tree t)
233 if (TREE_CODE (t) == FUNCTION_DECL)
235 current_function_decl = TREE_VALUE (saved_access_scope);
236 saved_access_scope = TREE_CHAIN (saved_access_scope);
239 if (DECL_FRIEND_CONTEXT (t) || DECL_CLASS_SCOPE_P (t))
245 /* Do any processing required when DECL (a member template
246 declaration) is finished. Returns the TEMPLATE_DECL corresponding
247 to DECL, unless it is a specialization, in which case the DECL
248 itself is returned. */
251 finish_member_template_decl (tree decl)
253 if (decl == error_mark_node)
254 return error_mark_node;
256 gcc_assert (DECL_P (decl));
258 if (TREE_CODE (decl) == TYPE_DECL)
262 type = TREE_TYPE (decl);
263 if (type == error_mark_node)
264 return error_mark_node;
265 if (MAYBE_CLASS_TYPE_P (type)
266 && CLASSTYPE_TEMPLATE_INFO (type)
267 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
269 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
270 check_member_template (tmpl);
275 else if (TREE_CODE (decl) == FIELD_DECL)
276 error ("data member %qD cannot be a member template", decl);
277 else if (DECL_TEMPLATE_INFO (decl))
279 if (!DECL_TEMPLATE_SPECIALIZATION (decl))
281 check_member_template (DECL_TI_TEMPLATE (decl));
282 return DECL_TI_TEMPLATE (decl);
288 error ("invalid member template declaration %qD", decl);
290 return error_mark_node;
293 /* Create a template info node. */
296 build_template_info (tree template_decl, tree template_args)
298 tree result = make_node (TEMPLATE_INFO);
299 TI_TEMPLATE (result) = template_decl;
300 TI_ARGS (result) = template_args;
304 /* Return the template info node corresponding to T, whatever T is. */
307 get_template_info (const_tree t)
309 tree tinfo = NULL_TREE;
311 if (!t || t == error_mark_node)
314 if (DECL_P (t) && DECL_LANG_SPECIFIC (t))
315 tinfo = DECL_TEMPLATE_INFO (t);
317 if (!tinfo && DECL_IMPLICIT_TYPEDEF_P (t))
320 if (TAGGED_TYPE_P (t))
321 tinfo = TYPE_TEMPLATE_INFO (t);
322 else if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
323 tinfo = TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (t);
328 /* Returns the template nesting level of the indicated class TYPE.
338 A<T>::B<U> has depth two, while A<T> has depth one.
339 Both A<T>::B<int> and A<int>::B<U> have depth one, if
340 they are instantiations, not specializations.
342 This function is guaranteed to return 0 if passed NULL_TREE so
343 that, for example, `template_class_depth (current_class_type)' is
347 template_class_depth (tree type)
352 type && TREE_CODE (type) != NAMESPACE_DECL;
353 type = (TREE_CODE (type) == FUNCTION_DECL)
354 ? CP_DECL_CONTEXT (type) : CP_TYPE_CONTEXT (type))
356 tree tinfo = get_template_info (type);
358 if (tinfo && PRIMARY_TEMPLATE_P (TI_TEMPLATE (tinfo))
359 && uses_template_parms (INNERMOST_TEMPLATE_ARGS (TI_ARGS (tinfo))))
366 /* Subroutine of maybe_begin_member_template_processing.
367 Returns true if processing DECL needs us to push template parms. */
370 inline_needs_template_parms (tree decl)
372 if (! DECL_TEMPLATE_INFO (decl))
375 return (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (most_general_template (decl)))
376 > (processing_template_decl + DECL_TEMPLATE_SPECIALIZATION (decl)));
379 /* Subroutine of maybe_begin_member_template_processing.
380 Push the template parms in PARMS, starting from LEVELS steps into the
381 chain, and ending at the beginning, since template parms are listed
385 push_inline_template_parms_recursive (tree parmlist, int levels)
387 tree parms = TREE_VALUE (parmlist);
391 push_inline_template_parms_recursive (TREE_CHAIN (parmlist), levels - 1);
393 ++processing_template_decl;
394 current_template_parms
395 = tree_cons (size_int (processing_template_decl),
396 parms, current_template_parms);
397 TEMPLATE_PARMS_FOR_INLINE (current_template_parms) = 1;
399 begin_scope (TREE_VEC_LENGTH (parms) ? sk_template_parms : sk_template_spec,
401 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
403 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
405 if (parm == error_mark_node)
408 gcc_assert (DECL_P (parm));
410 switch (TREE_CODE (parm))
419 /* Make a CONST_DECL as is done in process_template_parm.
420 It is ugly that we recreate this here; the original
421 version built in process_template_parm is no longer
423 tree decl = build_decl (DECL_SOURCE_LOCATION (parm),
424 CONST_DECL, DECL_NAME (parm),
426 DECL_ARTIFICIAL (decl) = 1;
427 TREE_CONSTANT (decl) = 1;
428 TREE_READONLY (decl) = 1;
429 DECL_INITIAL (decl) = DECL_INITIAL (parm);
430 SET_DECL_TEMPLATE_PARM_P (decl);
441 /* Restore the template parameter context for a member template or
442 a friend template defined in a class definition. */
445 maybe_begin_member_template_processing (tree decl)
450 if (inline_needs_template_parms (decl))
452 parms = DECL_TEMPLATE_PARMS (most_general_template (decl));
453 levels = TMPL_PARMS_DEPTH (parms) - processing_template_decl;
455 if (DECL_TEMPLATE_SPECIALIZATION (decl))
458 parms = TREE_CHAIN (parms);
461 push_inline_template_parms_recursive (parms, levels);
464 /* Remember how many levels of template parameters we pushed so that
465 we can pop them later. */
466 VEC_safe_push (int, heap, inline_parm_levels, levels);
469 /* Undo the effects of maybe_begin_member_template_processing. */
472 maybe_end_member_template_processing (void)
477 if (VEC_length (int, inline_parm_levels) == 0)
480 last = VEC_pop (int, inline_parm_levels);
481 for (i = 0; i < last; ++i)
483 --processing_template_decl;
484 current_template_parms = TREE_CHAIN (current_template_parms);
489 /* Return a new template argument vector which contains all of ARGS,
490 but has as its innermost set of arguments the EXTRA_ARGS. */
493 add_to_template_args (tree args, tree extra_args)
500 if (args == NULL_TREE || extra_args == error_mark_node)
503 extra_depth = TMPL_ARGS_DEPTH (extra_args);
504 new_args = make_tree_vec (TMPL_ARGS_DEPTH (args) + extra_depth);
506 for (i = 1; i <= TMPL_ARGS_DEPTH (args); ++i)
507 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (args, i));
509 for (j = 1; j <= extra_depth; ++j, ++i)
510 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (extra_args, j));
515 /* Like add_to_template_args, but only the outermost ARGS are added to
516 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
517 (EXTRA_ARGS) levels are added. This function is used to combine
518 the template arguments from a partial instantiation with the
519 template arguments used to attain the full instantiation from the
520 partial instantiation. */
523 add_outermost_template_args (tree args, tree extra_args)
527 /* If there are more levels of EXTRA_ARGS than there are ARGS,
528 something very fishy is going on. */
529 gcc_assert (TMPL_ARGS_DEPTH (args) >= TMPL_ARGS_DEPTH (extra_args));
531 /* If *all* the new arguments will be the EXTRA_ARGS, just return
533 if (TMPL_ARGS_DEPTH (args) == TMPL_ARGS_DEPTH (extra_args))
536 /* For the moment, we make ARGS look like it contains fewer levels. */
537 TREE_VEC_LENGTH (args) -= TMPL_ARGS_DEPTH (extra_args);
539 new_args = add_to_template_args (args, extra_args);
541 /* Now, we restore ARGS to its full dimensions. */
542 TREE_VEC_LENGTH (args) += TMPL_ARGS_DEPTH (extra_args);
547 /* Return the N levels of innermost template arguments from the ARGS. */
550 get_innermost_template_args (tree args, int n)
558 /* If N is 1, just return the innermost set of template arguments. */
560 return TMPL_ARGS_LEVEL (args, TMPL_ARGS_DEPTH (args));
562 /* If we're not removing anything, just return the arguments we were
564 extra_levels = TMPL_ARGS_DEPTH (args) - n;
565 gcc_assert (extra_levels >= 0);
566 if (extra_levels == 0)
569 /* Make a new set of arguments, not containing the outer arguments. */
570 new_args = make_tree_vec (n);
571 for (i = 1; i <= n; ++i)
572 SET_TMPL_ARGS_LEVEL (new_args, i,
573 TMPL_ARGS_LEVEL (args, i + extra_levels));
578 /* The inverse of get_innermost_template_args: Return all but the innermost
579 EXTRA_LEVELS levels of template arguments from the ARGS. */
582 strip_innermost_template_args (tree args, int extra_levels)
585 int n = TMPL_ARGS_DEPTH (args) - extra_levels;
590 /* If N is 1, just return the outermost set of template arguments. */
592 return TMPL_ARGS_LEVEL (args, 1);
594 /* If we're not removing anything, just return the arguments we were
596 gcc_assert (extra_levels >= 0);
597 if (extra_levels == 0)
600 /* Make a new set of arguments, not containing the inner arguments. */
601 new_args = make_tree_vec (n);
602 for (i = 1; i <= n; ++i)
603 SET_TMPL_ARGS_LEVEL (new_args, i,
604 TMPL_ARGS_LEVEL (args, i));
609 /* We've got a template header coming up; push to a new level for storing
613 begin_template_parm_list (void)
615 /* We use a non-tag-transparent scope here, which causes pushtag to
616 put tags in this scope, rather than in the enclosing class or
617 namespace scope. This is the right thing, since we want
618 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
619 global template class, push_template_decl handles putting the
620 TEMPLATE_DECL into top-level scope. For a nested template class,
623 template <class T> struct S1 {
624 template <class T> struct S2 {};
627 pushtag contains special code to call pushdecl_with_scope on the
628 TEMPLATE_DECL for S2. */
629 begin_scope (sk_template_parms, NULL);
630 ++processing_template_decl;
631 ++processing_template_parmlist;
632 note_template_header (0);
635 /* This routine is called when a specialization is declared. If it is
636 invalid to declare a specialization here, an error is reported and
637 false is returned, otherwise this routine will return true. */
640 check_specialization_scope (void)
642 tree scope = current_scope ();
646 An explicit specialization shall be declared in the namespace of
647 which the template is a member, or, for member templates, in the
648 namespace of which the enclosing class or enclosing class
649 template is a member. An explicit specialization of a member
650 function, member class or static data member of a class template
651 shall be declared in the namespace of which the class template
653 if (scope && TREE_CODE (scope) != NAMESPACE_DECL)
655 error ("explicit specialization in non-namespace scope %qD", scope);
661 In an explicit specialization declaration for a member of a class
662 template or a member template that appears in namespace scope,
663 the member template and some of its enclosing class templates may
664 remain unspecialized, except that the declaration shall not
665 explicitly specialize a class member template if its enclosing
666 class templates are not explicitly specialized as well. */
667 if (current_template_parms)
669 error ("enclosing class templates are not explicitly specialized");
676 /* We've just seen template <>. */
679 begin_specialization (void)
681 begin_scope (sk_template_spec, NULL);
682 note_template_header (1);
683 return check_specialization_scope ();
686 /* Called at then end of processing a declaration preceded by
690 end_specialization (void)
693 reset_specialization ();
696 /* Any template <>'s that we have seen thus far are not referring to a
697 function specialization. */
700 reset_specialization (void)
702 processing_specialization = 0;
703 template_header_count = 0;
706 /* We've just seen a template header. If SPECIALIZATION is nonzero,
707 it was of the form template <>. */
710 note_template_header (int specialization)
712 processing_specialization = specialization;
713 template_header_count++;
716 /* We're beginning an explicit instantiation. */
719 begin_explicit_instantiation (void)
721 gcc_assert (!processing_explicit_instantiation);
722 processing_explicit_instantiation = true;
727 end_explicit_instantiation (void)
729 gcc_assert (processing_explicit_instantiation);
730 processing_explicit_instantiation = false;
733 /* An explicit specialization or partial specialization TMPL is being
734 declared. Check that the namespace in which the specialization is
735 occurring is permissible. Returns false iff it is invalid to
736 specialize TMPL in the current namespace. */
739 check_specialization_namespace (tree tmpl)
741 tree tpl_ns = decl_namespace_context (tmpl);
745 An explicit specialization shall be declared in the namespace of
746 which the template is a member, or, for member templates, in the
747 namespace of which the enclosing class or enclosing class
748 template is a member. An explicit specialization of a member
749 function, member class or static data member of a class template
750 shall be declared in the namespace of which the class template is
752 if (current_scope() != DECL_CONTEXT (tmpl)
753 && !at_namespace_scope_p ())
755 error ("specialization of %qD must appear at namespace scope", tmpl);
758 if (is_associated_namespace (current_namespace, tpl_ns))
759 /* Same or super-using namespace. */
763 permerror (input_location, "specialization of %qD in different namespace", tmpl);
764 permerror (input_location, " from definition of %q+#D", tmpl);
769 /* SPEC is an explicit instantiation. Check that it is valid to
770 perform this explicit instantiation in the current namespace. */
773 check_explicit_instantiation_namespace (tree spec)
777 /* DR 275: An explicit instantiation shall appear in an enclosing
778 namespace of its template. */
779 ns = decl_namespace_context (spec);
780 if (!is_ancestor (current_namespace, ns))
781 permerror (input_location, "explicit instantiation of %qD in namespace %qD "
782 "(which does not enclose namespace %qD)",
783 spec, current_namespace, ns);
786 /* The TYPE is being declared. If it is a template type, that means it
787 is a partial specialization. Do appropriate error-checking. */
790 maybe_process_partial_specialization (tree type)
794 if (type == error_mark_node)
795 return error_mark_node;
797 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
799 error ("name of class shadows template template parameter %qD",
801 return error_mark_node;
804 context = TYPE_CONTEXT (type);
806 if (CLASS_TYPE_P (type) && CLASSTYPE_USE_TEMPLATE (type))
808 /* This is for ordinary explicit specialization and partial
809 specialization of a template class such as:
811 template <> class C<int>;
815 template <class T> class C<T*>;
817 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
819 if (CLASSTYPE_IMPLICIT_INSTANTIATION (type)
820 && !COMPLETE_TYPE_P (type))
822 check_specialization_namespace (CLASSTYPE_TI_TEMPLATE (type));
823 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
824 if (processing_template_decl)
826 if (push_template_decl (TYPE_MAIN_DECL (type))
828 return error_mark_node;
831 else if (CLASSTYPE_TEMPLATE_INSTANTIATION (type))
832 error ("specialization of %qT after instantiation", type);
834 else if (CLASS_TYPE_P (type)
835 && !CLASSTYPE_USE_TEMPLATE (type)
836 && CLASSTYPE_TEMPLATE_INFO (type)
837 && context && CLASS_TYPE_P (context)
838 && CLASSTYPE_TEMPLATE_INFO (context))
840 /* This is for an explicit specialization of member class
841 template according to [temp.expl.spec/18]:
843 template <> template <class U> class C<int>::D;
845 The context `C<int>' must be an implicit instantiation.
846 Otherwise this is just a member class template declared
849 template <> class C<int> { template <class U> class D; };
850 template <> template <class U> class C<int>::D;
852 In the first case, `C<int>::D' is a specialization of `C<T>::D'
853 while in the second case, `C<int>::D' is a primary template
854 and `C<T>::D' may not exist. */
856 if (CLASSTYPE_IMPLICIT_INSTANTIATION (context)
857 && !COMPLETE_TYPE_P (type))
860 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
862 if (current_namespace
863 != decl_namespace_context (tmpl))
865 permerror (input_location, "specializing %q#T in different namespace", type);
866 permerror (input_location, " from definition of %q+#D", tmpl);
869 /* Check for invalid specialization after instantiation:
871 template <> template <> class C<int>::D<int>;
872 template <> template <class U> class C<int>::D; */
874 for (t = DECL_TEMPLATE_INSTANTIATIONS (tmpl);
875 t; t = TREE_CHAIN (t))
877 tree inst = TREE_VALUE (t);
878 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (inst))
880 /* We already have a full specialization of this partial
881 instantiation. Reassign it to the new member
882 specialization template. */
886 elt.tmpl = most_general_template (tmpl);
887 elt.args = CLASSTYPE_TI_ARGS (inst);
890 htab_remove_elt (type_specializations, &elt);
893 elt.args = INNERMOST_TEMPLATE_ARGS (elt.args);
895 slot = (spec_entry **)
896 htab_find_slot (type_specializations, &elt, INSERT);
897 *slot = ggc_alloc_spec_entry ();
900 else if (COMPLETE_OR_OPEN_TYPE_P (inst))
901 /* But if we've had an implicit instantiation, that's a
902 problem ([temp.expl.spec]/6). */
903 error ("specialization %qT after instantiation %qT",
907 /* Mark TYPE as a specialization. And as a result, we only
908 have one level of template argument for the innermost
910 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
911 CLASSTYPE_TI_ARGS (type)
912 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type));
915 else if (processing_specialization)
917 /* Someday C++0x may allow for enum template specialization. */
918 if (cxx_dialect > cxx98 && TREE_CODE (type) == ENUMERAL_TYPE
919 && CLASS_TYPE_P (context) && CLASSTYPE_USE_TEMPLATE (context))
920 pedwarn (input_location, OPT_pedantic, "template specialization "
921 "of %qD not allowed by ISO C++", type);
924 error ("explicit specialization of non-template %qT", type);
925 return error_mark_node;
932 /* Returns nonzero if we can optimize the retrieval of specializations
933 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
934 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
937 optimize_specialization_lookup_p (tree tmpl)
939 return (DECL_FUNCTION_TEMPLATE_P (tmpl)
940 && DECL_CLASS_SCOPE_P (tmpl)
941 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
943 && CLASS_TYPE_P (DECL_CONTEXT (tmpl))
944 /* The optimized lookup depends on the fact that the
945 template arguments for the member function template apply
946 purely to the containing class, which is not true if the
947 containing class is an explicit or partial
949 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (tmpl))
950 && !DECL_MEMBER_TEMPLATE_P (tmpl)
951 && !DECL_CONV_FN_P (tmpl)
952 /* It is possible to have a template that is not a member
953 template and is not a member of a template class:
955 template <typename T>
956 struct S { friend A::f(); };
958 Here, the friend function is a template, but the context does
959 not have template information. The optimized lookup relies
960 on having ARGS be the template arguments for both the class
961 and the function template. */
962 && !DECL_FRIEND_P (DECL_TEMPLATE_RESULT (tmpl)));
965 /* Retrieve the specialization (in the sense of [temp.spec] - a
966 specialization is either an instantiation or an explicit
967 specialization) of TMPL for the given template ARGS. If there is
968 no such specialization, return NULL_TREE. The ARGS are a vector of
969 arguments, or a vector of vectors of arguments, in the case of
970 templates with more than one level of parameters.
972 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
973 then we search for a partial specialization matching ARGS. This
974 parameter is ignored if TMPL is not a class template. */
977 retrieve_specialization (tree tmpl, tree args, hashval_t hash)
979 if (args == error_mark_node)
982 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
984 /* There should be as many levels of arguments as there are
985 levels of parameters. */
986 gcc_assert (TMPL_ARGS_DEPTH (args)
987 == TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl)));
989 if (optimize_specialization_lookup_p (tmpl))
992 tree class_specialization;
993 VEC(tree,gc) *methods;
997 /* The template arguments actually apply to the containing
998 class. Find the class specialization with those
1000 class_template = CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (tmpl));
1001 class_specialization
1002 = retrieve_specialization (class_template, args, 0);
1003 if (!class_specialization)
1005 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
1006 for the specialization. */
1007 idx = class_method_index_for_fn (class_specialization, tmpl);
1010 /* Iterate through the methods with the indicated name, looking
1011 for the one that has an instance of TMPL. */
1012 methods = CLASSTYPE_METHOD_VEC (class_specialization);
1013 for (fns = VEC_index (tree, methods, idx); fns; fns = OVL_NEXT (fns))
1015 tree fn = OVL_CURRENT (fns);
1016 if (DECL_TEMPLATE_INFO (fn) && DECL_TI_TEMPLATE (fn) == tmpl
1017 /* using-declarations can add base methods to the method vec,
1018 and we don't want those here. */
1019 && DECL_CONTEXT (fn) == class_specialization)
1028 htab_t specializations;
1032 elt.spec = NULL_TREE;
1034 if (DECL_CLASS_TEMPLATE_P (tmpl))
1035 specializations = type_specializations;
1037 specializations = decl_specializations;
1040 hash = hash_specialization (&elt);
1041 found = (spec_entry *) htab_find_with_hash (specializations, &elt, hash);
1049 /* Like retrieve_specialization, but for local declarations. */
1052 retrieve_local_specialization (tree tmpl)
1056 if (local_specializations == NULL)
1059 spec = (tree) htab_find_with_hash (local_specializations, tmpl,
1060 htab_hash_pointer (tmpl));
1061 return spec ? TREE_PURPOSE (spec) : NULL_TREE;
1064 /* Returns nonzero iff DECL is a specialization of TMPL. */
1067 is_specialization_of (tree decl, tree tmpl)
1071 if (TREE_CODE (decl) == FUNCTION_DECL)
1075 t = DECL_TEMPLATE_INFO (t) ? DECL_TI_TEMPLATE (t) : NULL_TREE)
1081 gcc_assert (TREE_CODE (decl) == TYPE_DECL);
1083 for (t = TREE_TYPE (decl);
1085 t = CLASSTYPE_USE_TEMPLATE (t)
1086 ? TREE_TYPE (CLASSTYPE_TI_TEMPLATE (t)) : NULL_TREE)
1087 if (same_type_ignoring_top_level_qualifiers_p (t, TREE_TYPE (tmpl)))
1094 /* Returns nonzero iff DECL is a specialization of friend declaration
1095 FRIEND_DECL according to [temp.friend]. */
1098 is_specialization_of_friend (tree decl, tree friend_decl)
1100 bool need_template = true;
1103 gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
1104 || TREE_CODE (decl) == TYPE_DECL);
1106 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1107 of a template class, we want to check if DECL is a specialization
1109 if (TREE_CODE (friend_decl) == FUNCTION_DECL
1110 && DECL_TEMPLATE_INFO (friend_decl)
1111 && !DECL_USE_TEMPLATE (friend_decl))
1113 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1114 friend_decl = DECL_TI_TEMPLATE (friend_decl);
1115 need_template = false;
1117 else if (TREE_CODE (friend_decl) == TEMPLATE_DECL
1118 && !PRIMARY_TEMPLATE_P (friend_decl))
1119 need_template = false;
1121 /* There is nothing to do if this is not a template friend. */
1122 if (TREE_CODE (friend_decl) != TEMPLATE_DECL)
1125 if (is_specialization_of (decl, friend_decl))
1129 A member of a class template may be declared to be a friend of a
1130 non-template class. In this case, the corresponding member of
1131 every specialization of the class template is a friend of the
1132 class granting friendship.
1134 For example, given a template friend declaration
1136 template <class T> friend void A<T>::f();
1138 the member function below is considered a friend
1140 template <> struct A<int> {
1144 For this type of template friend, TEMPLATE_DEPTH below will be
1145 nonzero. To determine if DECL is a friend of FRIEND, we first
1146 check if the enclosing class is a specialization of another. */
1148 template_depth = template_class_depth (CP_DECL_CONTEXT (friend_decl));
1150 && DECL_CLASS_SCOPE_P (decl)
1151 && is_specialization_of (TYPE_NAME (DECL_CONTEXT (decl)),
1152 CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (friend_decl))))
1154 /* Next, we check the members themselves. In order to handle
1155 a few tricky cases, such as when FRIEND_DECL's are
1157 template <class T> friend void A<T>::g(T t);
1158 template <class T> template <T t> friend void A<T>::h();
1162 void A<int>::g(int);
1163 template <int> void A<int>::h();
1165 we need to figure out ARGS, the template arguments from
1166 the context of DECL. This is required for template substitution
1167 of `T' in the function parameter of `g' and template parameter
1168 of `h' in the above examples. Here ARGS corresponds to `int'. */
1170 tree context = DECL_CONTEXT (decl);
1171 tree args = NULL_TREE;
1172 int current_depth = 0;
1174 while (current_depth < template_depth)
1176 if (CLASSTYPE_TEMPLATE_INFO (context))
1178 if (current_depth == 0)
1179 args = TYPE_TI_ARGS (context);
1181 args = add_to_template_args (TYPE_TI_ARGS (context), args);
1184 context = TYPE_CONTEXT (context);
1187 if (TREE_CODE (decl) == FUNCTION_DECL)
1192 tree friend_args_type;
1193 tree decl_args_type;
1195 /* Make sure that both DECL and FRIEND_DECL are templates or
1197 is_template = DECL_TEMPLATE_INFO (decl)
1198 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (decl));
1199 if (need_template ^ is_template)
1201 else if (is_template)
1203 /* If both are templates, check template parameter list. */
1205 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1207 if (!comp_template_parms
1208 (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (decl)),
1212 decl_type = TREE_TYPE (DECL_TI_TEMPLATE (decl));
1215 decl_type = TREE_TYPE (decl);
1217 friend_type = tsubst_function_type (TREE_TYPE (friend_decl), args,
1218 tf_none, NULL_TREE);
1219 if (friend_type == error_mark_node)
1222 /* Check if return types match. */
1223 if (!same_type_p (TREE_TYPE (decl_type), TREE_TYPE (friend_type)))
1226 /* Check if function parameter types match, ignoring the
1227 `this' parameter. */
1228 friend_args_type = TYPE_ARG_TYPES (friend_type);
1229 decl_args_type = TYPE_ARG_TYPES (decl_type);
1230 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (friend_decl))
1231 friend_args_type = TREE_CHAIN (friend_args_type);
1232 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1233 decl_args_type = TREE_CHAIN (decl_args_type);
1235 return compparms (decl_args_type, friend_args_type);
1239 /* DECL is a TYPE_DECL */
1241 tree decl_type = TREE_TYPE (decl);
1243 /* Make sure that both DECL and FRIEND_DECL are templates or
1246 = CLASSTYPE_TEMPLATE_INFO (decl_type)
1247 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (decl_type));
1249 if (need_template ^ is_template)
1251 else if (is_template)
1254 /* If both are templates, check the name of the two
1255 TEMPLATE_DECL's first because is_friend didn't. */
1256 if (DECL_NAME (CLASSTYPE_TI_TEMPLATE (decl_type))
1257 != DECL_NAME (friend_decl))
1260 /* Now check template parameter list. */
1262 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1264 return comp_template_parms
1265 (DECL_TEMPLATE_PARMS (CLASSTYPE_TI_TEMPLATE (decl_type)),
1269 return (DECL_NAME (decl)
1270 == DECL_NAME (friend_decl));
1276 /* Register the specialization SPEC as a specialization of TMPL with
1277 the indicated ARGS. IS_FRIEND indicates whether the specialization
1278 is actually just a friend declaration. Returns SPEC, or an
1279 equivalent prior declaration, if available. */
1282 register_specialization (tree spec, tree tmpl, tree args, bool is_friend,
1286 spec_entry **slot = NULL;
1289 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL && DECL_P (spec));
1291 if (TREE_CODE (spec) == FUNCTION_DECL
1292 && uses_template_parms (DECL_TI_ARGS (spec)))
1293 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1294 register it; we want the corresponding TEMPLATE_DECL instead.
1295 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1296 the more obvious `uses_template_parms (spec)' to avoid problems
1297 with default function arguments. In particular, given
1298 something like this:
1300 template <class T> void f(T t1, T t = T())
1302 the default argument expression is not substituted for in an
1303 instantiation unless and until it is actually needed. */
1306 if (optimize_specialization_lookup_p (tmpl))
1307 /* We don't put these specializations in the hash table, but we might
1308 want to give an error about a mismatch. */
1309 fn = retrieve_specialization (tmpl, args, 0);
1317 hash = hash_specialization (&elt);
1319 slot = (spec_entry **)
1320 htab_find_slot_with_hash (decl_specializations, &elt, hash, INSERT);
1327 /* We can sometimes try to re-register a specialization that we've
1328 already got. In particular, regenerate_decl_from_template calls
1329 duplicate_decls which will update the specialization list. But,
1330 we'll still get called again here anyhow. It's more convenient
1331 to simply allow this than to try to prevent it. */
1334 else if (fn && DECL_TEMPLATE_SPECIALIZATION (spec))
1336 if (DECL_TEMPLATE_INSTANTIATION (fn))
1338 if (DECL_ODR_USED (fn)
1339 || DECL_EXPLICIT_INSTANTIATION (fn))
1341 error ("specialization of %qD after instantiation",
1343 return error_mark_node;
1348 /* This situation should occur only if the first
1349 specialization is an implicit instantiation, the
1350 second is an explicit specialization, and the
1351 implicit instantiation has not yet been used. That
1352 situation can occur if we have implicitly
1353 instantiated a member function and then specialized
1356 We can also wind up here if a friend declaration that
1357 looked like an instantiation turns out to be a
1360 template <class T> void foo(T);
1361 class S { friend void foo<>(int) };
1362 template <> void foo(int);
1364 We transform the existing DECL in place so that any
1365 pointers to it become pointers to the updated
1368 If there was a definition for the template, but not
1369 for the specialization, we want this to look as if
1370 there were no definition, and vice versa. */
1371 DECL_INITIAL (fn) = NULL_TREE;
1372 duplicate_decls (spec, fn, is_friend);
1373 /* The call to duplicate_decls will have applied
1376 An explicit specialization of a function template
1377 is inline only if it is explicitly declared to be,
1378 and independently of whether its function template
1381 to the primary function; now copy the inline bits to
1382 the various clones. */
1383 FOR_EACH_CLONE (clone, fn)
1385 DECL_DECLARED_INLINE_P (clone)
1386 = DECL_DECLARED_INLINE_P (fn);
1387 DECL_SOURCE_LOCATION (clone)
1388 = DECL_SOURCE_LOCATION (fn);
1390 check_specialization_namespace (fn);
1395 else if (DECL_TEMPLATE_SPECIALIZATION (fn))
1397 if (!duplicate_decls (spec, fn, is_friend) && DECL_INITIAL (spec))
1398 /* Dup decl failed, but this is a new definition. Set the
1399 line number so any errors match this new
1401 DECL_SOURCE_LOCATION (fn) = DECL_SOURCE_LOCATION (spec);
1407 return duplicate_decls (spec, fn, is_friend);
1409 /* A specialization must be declared in the same namespace as the
1410 template it is specializing. */
1411 if (DECL_TEMPLATE_SPECIALIZATION (spec)
1412 && !check_specialization_namespace (tmpl))
1413 DECL_CONTEXT (spec) = DECL_CONTEXT (tmpl);
1415 if (!optimize_specialization_lookup_p (tmpl))
1417 gcc_assert (tmpl && args && spec);
1418 *slot = ggc_alloc_spec_entry ();
1420 if (TREE_CODE (spec) == FUNCTION_DECL && DECL_NAMESPACE_SCOPE_P (spec)
1421 && PRIMARY_TEMPLATE_P (tmpl)
1422 && DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (tmpl)) == NULL_TREE)
1423 /* TMPL is a forward declaration of a template function; keep a list
1424 of all specializations in case we need to reassign them to a friend
1425 template later in tsubst_friend_function. */
1426 DECL_TEMPLATE_INSTANTIATIONS (tmpl)
1427 = tree_cons (args, spec, DECL_TEMPLATE_INSTANTIATIONS (tmpl));
1433 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1434 TMPL and ARGS members, ignores SPEC. */
1437 eq_specializations (const void *p1, const void *p2)
1439 const spec_entry *e1 = (const spec_entry *)p1;
1440 const spec_entry *e2 = (const spec_entry *)p2;
1442 return (e1->tmpl == e2->tmpl
1443 && comp_template_args (e1->args, e2->args));
1446 /* Returns a hash for a template TMPL and template arguments ARGS. */
1449 hash_tmpl_and_args (tree tmpl, tree args)
1451 hashval_t val = DECL_UID (tmpl);
1452 return iterative_hash_template_arg (args, val);
1455 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1459 hash_specialization (const void *p)
1461 const spec_entry *e = (const spec_entry *)p;
1462 return hash_tmpl_and_args (e->tmpl, e->args);
1465 /* Recursively calculate a hash value for a template argument ARG, for use
1466 in the hash tables of template specializations. */
1469 iterative_hash_template_arg (tree arg, hashval_t val)
1471 unsigned HOST_WIDE_INT i;
1472 enum tree_code code;
1475 if (arg == NULL_TREE)
1476 return iterative_hash_object (arg, val);
1481 if (TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
1482 /* We can get one of these when re-hashing a previous entry in the middle
1483 of substituting into a pack expansion. Just look through it. */
1484 arg = ARGUMENT_PACK_SELECT_FROM_PACK (arg);
1486 code = TREE_CODE (arg);
1487 tclass = TREE_CODE_CLASS (code);
1489 val = iterative_hash_object (code, val);
1496 case IDENTIFIER_NODE:
1497 return iterative_hash_object (IDENTIFIER_HASH_VALUE (arg), val);
1501 int i, len = TREE_VEC_LENGTH (arg);
1502 for (i = 0; i < len; ++i)
1503 val = iterative_hash_template_arg (TREE_VEC_ELT (arg, i), val);
1507 case TYPE_PACK_EXPANSION:
1508 case EXPR_PACK_EXPANSION:
1509 return iterative_hash_template_arg (PACK_EXPANSION_PATTERN (arg), val);
1511 case TYPE_ARGUMENT_PACK:
1512 case NONTYPE_ARGUMENT_PACK:
1513 return iterative_hash_template_arg (ARGUMENT_PACK_ARGS (arg), val);
1516 for (; arg; arg = TREE_CHAIN (arg))
1517 val = iterative_hash_template_arg (TREE_VALUE (arg), val);
1521 for (; arg; arg = OVL_NEXT (arg))
1522 val = iterative_hash_template_arg (OVL_CURRENT (arg), val);
1528 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg), i, field, value)
1530 val = iterative_hash_template_arg (field, val);
1531 val = iterative_hash_template_arg (value, val);
1537 if (!DECL_ARTIFICIAL (arg))
1539 val = iterative_hash_object (DECL_PARM_INDEX (arg), val);
1540 val = iterative_hash_object (DECL_PARM_LEVEL (arg), val);
1542 return iterative_hash_template_arg (TREE_TYPE (arg), val);
1545 return iterative_hash_template_arg (TARGET_EXPR_INITIAL (arg), val);
1548 val = iterative_hash_template_arg (PTRMEM_CST_CLASS (arg), val);
1549 return iterative_hash_template_arg (PTRMEM_CST_MEMBER (arg), val);
1551 case TEMPLATE_PARM_INDEX:
1552 val = iterative_hash_template_arg
1553 (TREE_TYPE (TEMPLATE_PARM_DECL (arg)), val);
1554 val = iterative_hash_object (TEMPLATE_PARM_LEVEL (arg), val);
1555 return iterative_hash_object (TEMPLATE_PARM_IDX (arg), val);
1558 val = iterative_hash_object (TRAIT_EXPR_KIND (arg), val);
1559 val = iterative_hash_template_arg (TRAIT_EXPR_TYPE1 (arg), val);
1560 return iterative_hash_template_arg (TRAIT_EXPR_TYPE2 (arg), val);
1563 val = iterative_hash_template_arg (BINFO_TYPE (BASELINK_BINFO (arg)),
1565 return iterative_hash_template_arg (DECL_NAME (get_first_fn (arg)),
1569 val = iterative_hash_template_arg (TREE_OPERAND (arg, 0), val);
1570 code = TREE_CODE (TREE_OPERAND (arg, 1));
1571 val = iterative_hash_object (code, val);
1572 return iterative_hash_template_arg (TREE_OPERAND (arg, 2), val);
1575 /* A lambda can't appear in a template arg, but don't crash on
1577 gcc_assert (seen_error ());
1581 case STATIC_CAST_EXPR:
1582 case REINTERPRET_CAST_EXPR:
1583 case CONST_CAST_EXPR:
1584 case DYNAMIC_CAST_EXPR:
1586 val = iterative_hash_template_arg (TREE_TYPE (arg), val);
1587 /* Now hash operands as usual. */
1597 if (TYPE_CANONICAL (arg))
1598 return iterative_hash_object (TYPE_HASH (TYPE_CANONICAL (arg)),
1600 else if (TREE_CODE (arg) == DECLTYPE_TYPE)
1601 return iterative_hash_template_arg (DECLTYPE_TYPE_EXPR (arg), val);
1602 /* Otherwise just compare the types during lookup. */
1605 case tcc_declaration:
1607 return iterative_hash_expr (arg, val);
1610 gcc_assert (IS_EXPR_CODE_CLASS (tclass));
1612 unsigned n = cp_tree_operand_length (arg);
1613 for (i = 0; i < n; ++i)
1614 val = iterative_hash_template_arg (TREE_OPERAND (arg, i), val);
1622 /* Unregister the specialization SPEC as a specialization of TMPL.
1623 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1624 if the SPEC was listed as a specialization of TMPL.
1626 Note that SPEC has been ggc_freed, so we can't look inside it. */
1629 reregister_specialization (tree spec, tree tinfo, tree new_spec)
1634 elt.tmpl = most_general_template (TI_TEMPLATE (tinfo));
1635 elt.args = TI_ARGS (tinfo);
1636 elt.spec = NULL_TREE;
1638 slot = (spec_entry **) htab_find_slot (decl_specializations, &elt, INSERT);
1641 gcc_assert ((*slot)->spec == spec || (*slot)->spec == new_spec);
1642 gcc_assert (new_spec != NULL_TREE);
1643 (*slot)->spec = new_spec;
1650 /* Compare an entry in the local specializations hash table P1 (which
1651 is really a pointer to a TREE_LIST) with P2 (which is really a
1655 eq_local_specializations (const void *p1, const void *p2)
1657 return TREE_VALUE ((const_tree) p1) == (const_tree) p2;
1660 /* Hash P1, an entry in the local specializations table. */
1663 hash_local_specialization (const void* p1)
1665 return htab_hash_pointer (TREE_VALUE ((const_tree) p1));
1668 /* Like register_specialization, but for local declarations. We are
1669 registering SPEC, an instantiation of TMPL. */
1672 register_local_specialization (tree spec, tree tmpl)
1676 slot = htab_find_slot_with_hash (local_specializations, tmpl,
1677 htab_hash_pointer (tmpl), INSERT);
1678 *slot = build_tree_list (spec, tmpl);
1681 /* TYPE is a class type. Returns true if TYPE is an explicitly
1682 specialized class. */
1685 explicit_class_specialization_p (tree type)
1687 if (!CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
1689 return !uses_template_parms (CLASSTYPE_TI_ARGS (type));
1692 /* Print the list of functions at FNS, going through all the overloads
1693 for each element of the list. Alternatively, FNS can not be a
1694 TREE_LIST, in which case it will be printed together with all the
1697 MORE and *STR should respectively be FALSE and NULL when the function
1698 is called from the outside. They are used internally on recursive
1699 calls. print_candidates manages the two parameters and leaves NULL
1700 in *STR when it ends. */
1703 print_candidates_1 (tree fns, bool more, const char **str)
1706 char *spaces = NULL;
1708 for (fn = fns; fn; fn = OVL_NEXT (fn))
1709 if (TREE_CODE (fn) == TREE_LIST)
1711 for (fn2 = fn; fn2 != NULL_TREE; fn2 = TREE_CHAIN (fn2))
1712 print_candidates_1 (TREE_VALUE (fn2),
1713 TREE_CHAIN (fn2) || more, str);
1719 /* Pick the prefix string. */
1720 if (!more && !OVL_NEXT (fns))
1722 error ("candidate is: %+#D", OVL_CURRENT (fn));
1726 *str = _("candidates are:");
1727 spaces = get_spaces (*str);
1729 error ("%s %+#D", *str, OVL_CURRENT (fn));
1730 *str = spaces ? spaces : *str;
1740 /* Print the list of candidate FNS in an error message. FNS can also
1741 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1744 print_candidates (tree fns)
1746 const char *str = NULL;
1747 print_candidates_1 (fns, false, &str);
1748 gcc_assert (str == NULL);
1751 /* Returns the template (one of the functions given by TEMPLATE_ID)
1752 which can be specialized to match the indicated DECL with the
1753 explicit template args given in TEMPLATE_ID. The DECL may be
1754 NULL_TREE if none is available. In that case, the functions in
1755 TEMPLATE_ID are non-members.
1757 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1758 specialization of a member template.
1760 The TEMPLATE_COUNT is the number of references to qualifying
1761 template classes that appeared in the name of the function. See
1762 check_explicit_specialization for a more accurate description.
1764 TSK indicates what kind of template declaration (if any) is being
1765 declared. TSK_TEMPLATE indicates that the declaration given by
1766 DECL, though a FUNCTION_DECL, has template parameters, and is
1767 therefore a template function.
1769 The template args (those explicitly specified and those deduced)
1770 are output in a newly created vector *TARGS_OUT.
1772 If it is impossible to determine the result, an error message is
1773 issued. The error_mark_node is returned to indicate failure. */
1776 determine_specialization (tree template_id,
1779 int need_member_template,
1785 tree explicit_targs;
1786 tree candidates = NULL_TREE;
1787 /* A TREE_LIST of templates of which DECL may be a specialization.
1788 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1789 corresponding TREE_PURPOSE is the set of template arguments that,
1790 when used to instantiate the template, would produce a function
1791 with the signature of DECL. */
1792 tree templates = NULL_TREE;
1794 struct cp_binding_level *b;
1796 *targs_out = NULL_TREE;
1798 if (template_id == error_mark_node || decl == error_mark_node)
1799 return error_mark_node;
1801 fns = TREE_OPERAND (template_id, 0);
1802 explicit_targs = TREE_OPERAND (template_id, 1);
1804 if (fns == error_mark_node)
1805 return error_mark_node;
1807 /* Check for baselinks. */
1808 if (BASELINK_P (fns))
1809 fns = BASELINK_FUNCTIONS (fns);
1811 if (!is_overloaded_fn (fns))
1813 error ("%qD is not a function template", fns);
1814 return error_mark_node;
1817 /* Count the number of template headers specified for this
1820 for (b = current_binding_level;
1821 b->kind == sk_template_parms;
1825 for (; fns; fns = OVL_NEXT (fns))
1827 tree fn = OVL_CURRENT (fns);
1829 if (TREE_CODE (fn) == TEMPLATE_DECL)
1831 tree decl_arg_types;
1834 /* In case of explicit specialization, we need to check if
1835 the number of template headers appearing in the specialization
1836 is correct. This is usually done in check_explicit_specialization,
1837 but the check done there cannot be exhaustive when specializing
1838 member functions. Consider the following code:
1840 template <> void A<int>::f(int);
1841 template <> template <> void A<int>::f(int);
1843 Assuming that A<int> is not itself an explicit specialization
1844 already, the first line specializes "f" which is a non-template
1845 member function, whilst the second line specializes "f" which
1846 is a template member function. So both lines are syntactically
1847 correct, and check_explicit_specialization does not reject
1850 Here, we can do better, as we are matching the specialization
1851 against the declarations. We count the number of template
1852 headers, and we check if they match TEMPLATE_COUNT + 1
1853 (TEMPLATE_COUNT is the number of qualifying template classes,
1854 plus there must be another header for the member template
1857 Notice that if header_count is zero, this is not a
1858 specialization but rather a template instantiation, so there
1859 is no check we can perform here. */
1860 if (header_count && header_count != template_count + 1)
1863 /* Check that the number of template arguments at the
1864 innermost level for DECL is the same as for FN. */
1865 if (current_binding_level->kind == sk_template_parms
1866 && !current_binding_level->explicit_spec_p
1867 && (TREE_VEC_LENGTH (DECL_INNERMOST_TEMPLATE_PARMS (fn))
1868 != TREE_VEC_LENGTH (INNERMOST_TEMPLATE_PARMS
1869 (current_template_parms))))
1872 /* DECL might be a specialization of FN. */
1873 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1874 fn_arg_types = TYPE_ARG_TYPES (TREE_TYPE (fn));
1876 /* For a non-static member function, we need to make sure
1877 that the const qualification is the same. Since
1878 get_bindings does not try to merge the "this" parameter,
1879 we must do the comparison explicitly. */
1880 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
1881 && !same_type_p (TREE_VALUE (fn_arg_types),
1882 TREE_VALUE (decl_arg_types)))
1885 /* Skip the "this" parameter and, for constructors of
1886 classes with virtual bases, the VTT parameter. A
1887 full specialization of a constructor will have a VTT
1888 parameter, but a template never will. */
1890 = skip_artificial_parms_for (decl, decl_arg_types);
1892 = skip_artificial_parms_for (fn, fn_arg_types);
1894 /* Check that the number of function parameters matches.
1896 template <class T> void f(int i = 0);
1897 template <> void f<int>();
1898 The specialization f<int> is invalid but is not caught
1899 by get_bindings below. */
1900 if (list_length (fn_arg_types) != list_length (decl_arg_types))
1903 /* Function templates cannot be specializations; there are
1904 no partial specializations of functions. Therefore, if
1905 the type of DECL does not match FN, there is no
1907 if (tsk == tsk_template)
1909 if (compparms (fn_arg_types, decl_arg_types))
1910 candidates = tree_cons (NULL_TREE, fn, candidates);
1914 /* See whether this function might be a specialization of this
1916 targs = get_bindings (fn, decl, explicit_targs, /*check_ret=*/true);
1919 /* We cannot deduce template arguments that when used to
1920 specialize TMPL will produce DECL. */
1923 /* Save this template, and the arguments deduced. */
1924 templates = tree_cons (targs, fn, templates);
1926 else if (need_member_template)
1927 /* FN is an ordinary member function, and we need a
1928 specialization of a member template. */
1930 else if (TREE_CODE (fn) != FUNCTION_DECL)
1931 /* We can get IDENTIFIER_NODEs here in certain erroneous
1934 else if (!DECL_FUNCTION_MEMBER_P (fn))
1935 /* This is just an ordinary non-member function. Nothing can
1936 be a specialization of that. */
1938 else if (DECL_ARTIFICIAL (fn))
1939 /* Cannot specialize functions that are created implicitly. */
1943 tree decl_arg_types;
1945 /* This is an ordinary member function. However, since
1946 we're here, we can assume it's enclosing class is a
1947 template class. For example,
1949 template <typename T> struct S { void f(); };
1950 template <> void S<int>::f() {}
1952 Here, S<int>::f is a non-template, but S<int> is a
1953 template class. If FN has the same type as DECL, we
1954 might be in business. */
1956 if (!DECL_TEMPLATE_INFO (fn))
1957 /* Its enclosing class is an explicit specialization
1958 of a template class. This is not a candidate. */
1961 if (!same_type_p (TREE_TYPE (TREE_TYPE (decl)),
1962 TREE_TYPE (TREE_TYPE (fn))))
1963 /* The return types differ. */
1966 /* Adjust the type of DECL in case FN is a static member. */
1967 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1968 if (DECL_STATIC_FUNCTION_P (fn)
1969 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1970 decl_arg_types = TREE_CHAIN (decl_arg_types);
1972 if (compparms (TYPE_ARG_TYPES (TREE_TYPE (fn)),
1975 candidates = tree_cons (NULL_TREE, fn, candidates);
1979 if (templates && TREE_CHAIN (templates))
1985 It is possible for a specialization with a given function
1986 signature to be instantiated from more than one function
1987 template. In such cases, explicit specification of the
1988 template arguments must be used to uniquely identify the
1989 function template specialization being specialized.
1991 Note that here, there's no suggestion that we're supposed to
1992 determine which of the candidate templates is most
1993 specialized. However, we, also have:
1997 Partial ordering of overloaded function template
1998 declarations is used in the following contexts to select
1999 the function template to which a function template
2000 specialization refers:
2002 -- when an explicit specialization refers to a function
2005 So, we do use the partial ordering rules, at least for now.
2006 This extension can only serve to make invalid programs valid,
2007 so it's safe. And, there is strong anecdotal evidence that
2008 the committee intended the partial ordering rules to apply;
2009 the EDG front end has that behavior, and John Spicer claims
2010 that the committee simply forgot to delete the wording in
2011 [temp.expl.spec]. */
2012 tree tmpl = most_specialized_instantiation (templates);
2013 if (tmpl != error_mark_node)
2016 TREE_CHAIN (templates) = NULL_TREE;
2020 if (templates == NULL_TREE && candidates == NULL_TREE)
2022 error ("template-id %qD for %q+D does not match any template "
2023 "declaration", template_id, decl);
2024 if (header_count && header_count != template_count + 1)
2025 inform (input_location, "saw %d %<template<>%>, need %d for "
2026 "specializing a member function template",
2027 header_count, template_count + 1);
2028 return error_mark_node;
2030 else if ((templates && TREE_CHAIN (templates))
2031 || (candidates && TREE_CHAIN (candidates))
2032 || (templates && candidates))
2034 error ("ambiguous template specialization %qD for %q+D",
2036 candidates = chainon (candidates, templates);
2037 print_candidates (candidates);
2038 return error_mark_node;
2041 /* We have one, and exactly one, match. */
2044 tree fn = TREE_VALUE (candidates);
2045 *targs_out = copy_node (DECL_TI_ARGS (fn));
2046 /* DECL is a re-declaration or partial instantiation of a template
2048 if (TREE_CODE (fn) == TEMPLATE_DECL)
2050 /* It was a specialization of an ordinary member function in a
2052 return DECL_TI_TEMPLATE (fn);
2055 /* It was a specialization of a template. */
2056 targs = DECL_TI_ARGS (DECL_TEMPLATE_RESULT (TREE_VALUE (templates)));
2057 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (targs))
2059 *targs_out = copy_node (targs);
2060 SET_TMPL_ARGS_LEVEL (*targs_out,
2061 TMPL_ARGS_DEPTH (*targs_out),
2062 TREE_PURPOSE (templates));
2065 *targs_out = TREE_PURPOSE (templates);
2066 return TREE_VALUE (templates);
2069 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2070 but with the default argument values filled in from those in the
2074 copy_default_args_to_explicit_spec_1 (tree spec_types,
2077 tree new_spec_types;
2082 if (spec_types == void_list_node)
2083 return void_list_node;
2085 /* Substitute into the rest of the list. */
2087 copy_default_args_to_explicit_spec_1 (TREE_CHAIN (spec_types),
2088 TREE_CHAIN (tmpl_types));
2090 /* Add the default argument for this parameter. */
2091 return hash_tree_cons (TREE_PURPOSE (tmpl_types),
2092 TREE_VALUE (spec_types),
2096 /* DECL is an explicit specialization. Replicate default arguments
2097 from the template it specializes. (That way, code like:
2099 template <class T> void f(T = 3);
2100 template <> void f(double);
2103 works, as required.) An alternative approach would be to look up
2104 the correct default arguments at the call-site, but this approach
2105 is consistent with how implicit instantiations are handled. */
2108 copy_default_args_to_explicit_spec (tree decl)
2113 tree new_spec_types;
2117 tree object_type = NULL_TREE;
2118 tree in_charge = NULL_TREE;
2119 tree vtt = NULL_TREE;
2121 /* See if there's anything we need to do. */
2122 tmpl = DECL_TI_TEMPLATE (decl);
2123 tmpl_types = TYPE_ARG_TYPES (TREE_TYPE (DECL_TEMPLATE_RESULT (tmpl)));
2124 for (t = tmpl_types; t; t = TREE_CHAIN (t))
2125 if (TREE_PURPOSE (t))
2130 old_type = TREE_TYPE (decl);
2131 spec_types = TYPE_ARG_TYPES (old_type);
2133 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2135 /* Remove the this pointer, but remember the object's type for
2137 object_type = TREE_TYPE (TREE_VALUE (spec_types));
2138 spec_types = TREE_CHAIN (spec_types);
2139 tmpl_types = TREE_CHAIN (tmpl_types);
2141 if (DECL_HAS_IN_CHARGE_PARM_P (decl))
2143 /* DECL may contain more parameters than TMPL due to the extra
2144 in-charge parameter in constructors and destructors. */
2145 in_charge = spec_types;
2146 spec_types = TREE_CHAIN (spec_types);
2148 if (DECL_HAS_VTT_PARM_P (decl))
2151 spec_types = TREE_CHAIN (spec_types);
2155 /* Compute the merged default arguments. */
2157 copy_default_args_to_explicit_spec_1 (spec_types, tmpl_types);
2159 /* Compute the new FUNCTION_TYPE. */
2163 new_spec_types = hash_tree_cons (TREE_PURPOSE (vtt),
2168 /* Put the in-charge parameter back. */
2169 new_spec_types = hash_tree_cons (TREE_PURPOSE (in_charge),
2170 TREE_VALUE (in_charge),
2173 new_type = build_method_type_directly (object_type,
2174 TREE_TYPE (old_type),
2178 new_type = build_function_type (TREE_TYPE (old_type),
2180 new_type = cp_build_type_attribute_variant (new_type,
2181 TYPE_ATTRIBUTES (old_type));
2182 new_type = build_exception_variant (new_type,
2183 TYPE_RAISES_EXCEPTIONS (old_type));
2184 TREE_TYPE (decl) = new_type;
2187 /* Check to see if the function just declared, as indicated in
2188 DECLARATOR, and in DECL, is a specialization of a function
2189 template. We may also discover that the declaration is an explicit
2190 instantiation at this point.
2192 Returns DECL, or an equivalent declaration that should be used
2193 instead if all goes well. Issues an error message if something is
2194 amiss. Returns error_mark_node if the error is not easily
2197 FLAGS is a bitmask consisting of the following flags:
2199 2: The function has a definition.
2200 4: The function is a friend.
2202 The TEMPLATE_COUNT is the number of references to qualifying
2203 template classes that appeared in the name of the function. For
2206 template <class T> struct S { void f(); };
2209 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2210 classes are not counted in the TEMPLATE_COUNT, so that in
2212 template <class T> struct S {};
2213 template <> struct S<int> { void f(); }
2214 template <> void S<int>::f();
2216 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2217 invalid; there should be no template <>.)
2219 If the function is a specialization, it is marked as such via
2220 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2221 is set up correctly, and it is added to the list of specializations
2222 for that template. */
2225 check_explicit_specialization (tree declarator,
2230 int have_def = flags & 2;
2231 int is_friend = flags & 4;
2232 int specialization = 0;
2233 int explicit_instantiation = 0;
2234 int member_specialization = 0;
2235 tree ctype = DECL_CLASS_CONTEXT (decl);
2236 tree dname = DECL_NAME (decl);
2241 if (!processing_specialization)
2244 tsk = tsk_excessive_parms;
2247 tsk = current_tmpl_spec_kind (template_count);
2252 if (processing_specialization)
2255 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2257 else if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2260 /* This could be something like:
2262 template <class T> void f(T);
2263 class S { friend void f<>(int); } */
2267 /* This case handles bogus declarations like template <>
2268 template <class T> void f<int>(); */
2270 error ("template-id %qD in declaration of primary template",
2277 case tsk_invalid_member_spec:
2278 /* The error has already been reported in
2279 check_specialization_scope. */
2280 return error_mark_node;
2282 case tsk_invalid_expl_inst:
2283 error ("template parameter list used in explicit instantiation");
2289 error ("definition provided for explicit instantiation");
2291 explicit_instantiation = 1;
2294 case tsk_excessive_parms:
2295 case tsk_insufficient_parms:
2296 if (tsk == tsk_excessive_parms)
2297 error ("too many template parameter lists in declaration of %qD",
2299 else if (template_header_count)
2300 error("too few template parameter lists in declaration of %qD", decl);
2302 error("explicit specialization of %qD must be introduced by "
2303 "%<template <>%>", decl);
2307 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2309 member_specialization = 1;
2315 if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2317 /* This case handles bogus declarations like template <>
2318 template <class T> void f<int>(); */
2320 if (uses_template_parms (declarator))
2321 error ("function template partial specialization %qD "
2322 "is not allowed", declarator);
2324 error ("template-id %qD in declaration of primary template",
2329 if (ctype && CLASSTYPE_TEMPLATE_INSTANTIATION (ctype))
2330 /* This is a specialization of a member template, without
2331 specialization the containing class. Something like:
2333 template <class T> struct S {
2334 template <class U> void f (U);
2336 template <> template <class U> void S<int>::f(U) {}
2338 That's a specialization -- but of the entire template. */
2346 if (specialization || member_specialization)
2348 tree t = TYPE_ARG_TYPES (TREE_TYPE (decl));
2349 for (; t; t = TREE_CHAIN (t))
2350 if (TREE_PURPOSE (t))
2352 permerror (input_location,
2353 "default argument specified in explicit specialization");
2358 if (specialization || member_specialization || explicit_instantiation)
2360 tree tmpl = NULL_TREE;
2361 tree targs = NULL_TREE;
2363 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2364 if (TREE_CODE (declarator) != TEMPLATE_ID_EXPR)
2368 gcc_assert (TREE_CODE (declarator) == IDENTIFIER_NODE);
2373 /* If there is no class context, the explicit instantiation
2374 must be at namespace scope. */
2375 gcc_assert (DECL_NAMESPACE_SCOPE_P (decl));
2377 /* Find the namespace binding, using the declaration
2379 fns = lookup_qualified_name (CP_DECL_CONTEXT (decl), dname,
2381 if (fns == error_mark_node || !is_overloaded_fn (fns))
2383 error ("%qD is not a template function", dname);
2384 fns = error_mark_node;
2388 tree fn = OVL_CURRENT (fns);
2389 if (!is_associated_namespace (CP_DECL_CONTEXT (decl),
2390 CP_DECL_CONTEXT (fn)))
2391 error ("%qD is not declared in %qD",
2392 decl, current_namespace);
2396 declarator = lookup_template_function (fns, NULL_TREE);
2399 if (declarator == error_mark_node)
2400 return error_mark_node;
2402 if (ctype != NULL_TREE && TYPE_BEING_DEFINED (ctype))
2404 if (!explicit_instantiation)
2405 /* A specialization in class scope. This is invalid,
2406 but the error will already have been flagged by
2407 check_specialization_scope. */
2408 return error_mark_node;
2411 /* It's not valid to write an explicit instantiation in
2414 class C { template void f(); }
2416 This case is caught by the parser. However, on
2419 template class C { void f(); };
2421 (which is invalid) we can get here. The error will be
2428 else if (ctype != NULL_TREE
2429 && (TREE_CODE (TREE_OPERAND (declarator, 0)) ==
2432 /* Find the list of functions in ctype that have the same
2433 name as the declared function. */
2434 tree name = TREE_OPERAND (declarator, 0);
2435 tree fns = NULL_TREE;
2438 if (constructor_name_p (name, ctype))
2440 int is_constructor = DECL_CONSTRUCTOR_P (decl);
2442 if (is_constructor ? !TYPE_HAS_USER_CONSTRUCTOR (ctype)
2443 : !CLASSTYPE_DESTRUCTORS (ctype))
2445 /* From [temp.expl.spec]:
2447 If such an explicit specialization for the member
2448 of a class template names an implicitly-declared
2449 special member function (clause _special_), the
2450 program is ill-formed.
2452 Similar language is found in [temp.explicit]. */
2453 error ("specialization of implicitly-declared special member function");
2454 return error_mark_node;
2457 name = is_constructor ? ctor_identifier : dtor_identifier;
2460 if (!DECL_CONV_FN_P (decl))
2462 idx = lookup_fnfields_1 (ctype, name);
2464 fns = VEC_index (tree, CLASSTYPE_METHOD_VEC (ctype), idx);
2468 VEC(tree,gc) *methods;
2471 /* For a type-conversion operator, we cannot do a
2472 name-based lookup. We might be looking for `operator
2473 int' which will be a specialization of `operator T'.
2474 So, we find *all* the conversion operators, and then
2475 select from them. */
2478 methods = CLASSTYPE_METHOD_VEC (ctype);
2480 for (idx = CLASSTYPE_FIRST_CONVERSION_SLOT;
2481 VEC_iterate (tree, methods, idx, ovl);
2484 if (!DECL_CONV_FN_P (OVL_CURRENT (ovl)))
2485 /* There are no more conversion functions. */
2488 /* Glue all these conversion functions together
2489 with those we already have. */
2490 for (; ovl; ovl = OVL_NEXT (ovl))
2491 fns = ovl_cons (OVL_CURRENT (ovl), fns);
2495 if (fns == NULL_TREE)
2497 error ("no member function %qD declared in %qT", name, ctype);
2498 return error_mark_node;
2501 TREE_OPERAND (declarator, 0) = fns;
2504 /* Figure out what exactly is being specialized at this point.
2505 Note that for an explicit instantiation, even one for a
2506 member function, we cannot tell apriori whether the
2507 instantiation is for a member template, or just a member
2508 function of a template class. Even if a member template is
2509 being instantiated, the member template arguments may be
2510 elided if they can be deduced from the rest of the
2512 tmpl = determine_specialization (declarator, decl,
2514 member_specialization,
2518 if (!tmpl || tmpl == error_mark_node)
2519 /* We couldn't figure out what this declaration was
2521 return error_mark_node;
2524 tree gen_tmpl = most_general_template (tmpl);
2526 if (explicit_instantiation)
2528 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2529 is done by do_decl_instantiation later. */
2531 int arg_depth = TMPL_ARGS_DEPTH (targs);
2532 int parm_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
2534 if (arg_depth > parm_depth)
2536 /* If TMPL is not the most general template (for
2537 example, if TMPL is a friend template that is
2538 injected into namespace scope), then there will
2539 be too many levels of TARGS. Remove some of them
2544 new_targs = make_tree_vec (parm_depth);
2545 for (i = arg_depth - parm_depth; i < arg_depth; ++i)
2546 TREE_VEC_ELT (new_targs, i - (arg_depth - parm_depth))
2547 = TREE_VEC_ELT (targs, i);
2551 return instantiate_template (tmpl, targs, tf_error);
2554 /* If we thought that the DECL was a member function, but it
2555 turns out to be specializing a static member function,
2556 make DECL a static member function as well. */
2557 if (DECL_STATIC_FUNCTION_P (tmpl)
2558 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2559 revert_static_member_fn (decl);
2561 /* If this is a specialization of a member template of a
2562 template class, we want to return the TEMPLATE_DECL, not
2563 the specialization of it. */
2564 if (tsk == tsk_template)
2566 tree result = DECL_TEMPLATE_RESULT (tmpl);
2567 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
2568 DECL_INITIAL (result) = NULL_TREE;
2572 DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl);
2573 DECL_SOURCE_LOCATION (result)
2574 = DECL_SOURCE_LOCATION (decl);
2575 /* We want to use the argument list specified in the
2576 definition, not in the original declaration. */
2577 DECL_ARGUMENTS (result) = DECL_ARGUMENTS (decl);
2578 for (parm = DECL_ARGUMENTS (result); parm;
2579 parm = DECL_CHAIN (parm))
2580 DECL_CONTEXT (parm) = result;
2582 return register_specialization (tmpl, gen_tmpl, targs,
2586 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2587 DECL_TEMPLATE_INFO (decl) = build_template_info (tmpl, targs);
2589 /* Inherit default function arguments from the template
2590 DECL is specializing. */
2591 copy_default_args_to_explicit_spec (decl);
2593 /* This specialization has the same protection as the
2594 template it specializes. */
2595 TREE_PRIVATE (decl) = TREE_PRIVATE (gen_tmpl);
2596 TREE_PROTECTED (decl) = TREE_PROTECTED (gen_tmpl);
2598 /* 7.1.1-1 [dcl.stc]
2600 A storage-class-specifier shall not be specified in an
2601 explicit specialization...
2603 The parser rejects these, so unless action is taken here,
2604 explicit function specializations will always appear with
2607 The action recommended by the C++ CWG in response to C++
2608 defect report 605 is to make the storage class and linkage
2609 of the explicit specialization match the templated function:
2611 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2613 if (tsk == tsk_expl_spec && DECL_FUNCTION_TEMPLATE_P (gen_tmpl))
2615 tree tmpl_func = DECL_TEMPLATE_RESULT (gen_tmpl);
2616 gcc_assert (TREE_CODE (tmpl_func) == FUNCTION_DECL);
2618 /* This specialization has the same linkage and visibility as
2619 the function template it specializes. */
2620 TREE_PUBLIC (decl) = TREE_PUBLIC (tmpl_func);
2621 if (! TREE_PUBLIC (decl))
2623 DECL_INTERFACE_KNOWN (decl) = 1;
2624 DECL_NOT_REALLY_EXTERN (decl) = 1;
2626 DECL_THIS_STATIC (decl) = DECL_THIS_STATIC (tmpl_func);
2627 if (DECL_VISIBILITY_SPECIFIED (tmpl_func))
2629 DECL_VISIBILITY_SPECIFIED (decl) = 1;
2630 DECL_VISIBILITY (decl) = DECL_VISIBILITY (tmpl_func);
2634 /* If DECL is a friend declaration, declared using an
2635 unqualified name, the namespace associated with DECL may
2636 have been set incorrectly. For example, in:
2638 template <typename T> void f(T);
2640 struct S { friend void f<int>(int); }
2643 we will have set the DECL_CONTEXT for the friend
2644 declaration to N, rather than to the global namespace. */
2645 if (DECL_NAMESPACE_SCOPE_P (decl))
2646 DECL_CONTEXT (decl) = DECL_CONTEXT (tmpl);
2648 if (is_friend && !have_def)
2649 /* This is not really a declaration of a specialization.
2650 It's just the name of an instantiation. But, it's not
2651 a request for an instantiation, either. */
2652 SET_DECL_IMPLICIT_INSTANTIATION (decl);
2653 else if (DECL_CONSTRUCTOR_P (decl) || DECL_DESTRUCTOR_P (decl))
2654 /* This is indeed a specialization. In case of constructors
2655 and destructors, we need in-charge and not-in-charge
2656 versions in V3 ABI. */
2657 clone_function_decl (decl, /*update_method_vec_p=*/0);
2659 /* Register this specialization so that we can find it
2661 decl = register_specialization (decl, gen_tmpl, targs, is_friend, 0);
2668 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2669 parameters. These are represented in the same format used for
2670 DECL_TEMPLATE_PARMS. */
2673 comp_template_parms (const_tree parms1, const_tree parms2)
2678 if (parms1 == parms2)
2681 for (p1 = parms1, p2 = parms2;
2682 p1 != NULL_TREE && p2 != NULL_TREE;
2683 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2))
2685 tree t1 = TREE_VALUE (p1);
2686 tree t2 = TREE_VALUE (p2);
2689 gcc_assert (TREE_CODE (t1) == TREE_VEC);
2690 gcc_assert (TREE_CODE (t2) == TREE_VEC);
2692 if (TREE_VEC_LENGTH (t1) != TREE_VEC_LENGTH (t2))
2695 for (i = 0; i < TREE_VEC_LENGTH (t2); ++i)
2697 tree parm1 = TREE_VALUE (TREE_VEC_ELT (t1, i));
2698 tree parm2 = TREE_VALUE (TREE_VEC_ELT (t2, i));
2700 /* If either of the template parameters are invalid, assume
2701 they match for the sake of error recovery. */
2702 if (parm1 == error_mark_node || parm2 == error_mark_node)
2705 if (TREE_CODE (parm1) != TREE_CODE (parm2))
2708 if (TREE_CODE (parm1) == TEMPLATE_TYPE_PARM
2709 && (TEMPLATE_TYPE_PARAMETER_PACK (parm1)
2710 == TEMPLATE_TYPE_PARAMETER_PACK (parm2)))
2712 else if (!same_type_p (TREE_TYPE (parm1), TREE_TYPE (parm2)))
2717 if ((p1 != NULL_TREE) != (p2 != NULL_TREE))
2718 /* One set of parameters has more parameters lists than the
2725 /* Determine whether PARM is a parameter pack. */
2728 template_parameter_pack_p (const_tree parm)
2730 /* Determine if we have a non-type template parameter pack. */
2731 if (TREE_CODE (parm) == PARM_DECL)
2732 return (DECL_TEMPLATE_PARM_P (parm)
2733 && TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)));
2735 /* If this is a list of template parameters, we could get a
2736 TYPE_DECL or a TEMPLATE_DECL. */
2737 if (TREE_CODE (parm) == TYPE_DECL || TREE_CODE (parm) == TEMPLATE_DECL)
2738 parm = TREE_TYPE (parm);
2740 return ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
2741 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM)
2742 && TEMPLATE_TYPE_PARAMETER_PACK (parm));
2745 /* Determine if T is a function parameter pack. */
2748 function_parameter_pack_p (const_tree t)
2750 if (t && TREE_CODE (t) == PARM_DECL)
2751 return FUNCTION_PARAMETER_PACK_P (t);
2755 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2756 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2759 get_function_template_decl (const_tree primary_func_tmpl_inst)
2761 if (! primary_func_tmpl_inst
2762 || TREE_CODE (primary_func_tmpl_inst) != FUNCTION_DECL
2763 || ! primary_template_instantiation_p (primary_func_tmpl_inst))
2766 return DECL_TEMPLATE_RESULT (DECL_TI_TEMPLATE (primary_func_tmpl_inst));
2769 /* Return true iff the function parameter PARAM_DECL was expanded
2770 from the function parameter pack PACK. */
2773 function_parameter_expanded_from_pack_p (tree param_decl, tree pack)
2775 if (DECL_ARTIFICIAL (param_decl)
2776 || !function_parameter_pack_p (pack))
2779 /* The parameter pack and its pack arguments have the same
2781 return DECL_PARM_INDEX (pack) == DECL_PARM_INDEX (param_decl);
2784 /* Determine whether ARGS describes a variadic template args list,
2785 i.e., one that is terminated by a template argument pack. */
2788 template_args_variadic_p (tree args)
2793 if (args == NULL_TREE)
2796 args = INNERMOST_TEMPLATE_ARGS (args);
2797 nargs = TREE_VEC_LENGTH (args);
2802 last_parm = TREE_VEC_ELT (args, nargs - 1);
2804 return ARGUMENT_PACK_P (last_parm);
2807 /* Generate a new name for the parameter pack name NAME (an
2808 IDENTIFIER_NODE) that incorporates its */
2811 make_ith_pack_parameter_name (tree name, int i)
2813 /* Munge the name to include the parameter index. */
2814 #define NUMBUF_LEN 128
2815 char numbuf[NUMBUF_LEN];
2819 snprintf (numbuf, NUMBUF_LEN, "%i", i);
2820 newname_len = IDENTIFIER_LENGTH (name)
2821 + strlen (numbuf) + 2;
2822 newname = (char*)alloca (newname_len);
2823 snprintf (newname, newname_len,
2824 "%s#%i", IDENTIFIER_POINTER (name), i);
2825 return get_identifier (newname);
2828 /* Return true if T is a primary function
2829 or class template instantiation. */
2832 primary_template_instantiation_p (const_tree t)
2837 if (TREE_CODE (t) == FUNCTION_DECL)
2838 return DECL_LANG_SPECIFIC (t)
2839 && DECL_TEMPLATE_INSTANTIATION (t)
2840 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (t));
2841 else if (CLASS_TYPE_P (t))
2842 return CLASSTYPE_TEMPLATE_INSTANTIATION (t)
2843 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (t));
2847 /* Return true if PARM is a template template parameter. */
2850 template_template_parameter_p (const_tree parm)
2852 return DECL_TEMPLATE_TEMPLATE_PARM_P (parm);
2855 /* Return the template parameters of T if T is a
2856 primary template instantiation, NULL otherwise. */
2859 get_primary_template_innermost_parameters (const_tree t)
2861 tree parms = NULL, template_info = NULL;
2863 if ((template_info = get_template_info (t))
2864 && primary_template_instantiation_p (t))
2865 parms = INNERMOST_TEMPLATE_PARMS
2866 (DECL_TEMPLATE_PARMS (TI_TEMPLATE (template_info)));
2871 /* Return the template parameters of the LEVELth level from the full list
2872 of template parameters PARMS. */
2875 get_template_parms_at_level (tree parms, int level)
2879 || TREE_CODE (parms) != TREE_LIST
2880 || level > TMPL_PARMS_DEPTH (parms))
2883 for (p = parms; p; p = TREE_CHAIN (p))
2884 if (TMPL_PARMS_DEPTH (p) == level)
2890 /* Returns the template arguments of T if T is a template instantiation,
2894 get_template_innermost_arguments (const_tree t)
2896 tree args = NULL, template_info = NULL;
2898 if ((template_info = get_template_info (t))
2899 && TI_ARGS (template_info))
2900 args = INNERMOST_TEMPLATE_ARGS (TI_ARGS (template_info));
2905 /* Return the argument pack elements of T if T is a template argument pack,
2909 get_template_argument_pack_elems (const_tree t)
2911 if (TREE_CODE (t) != TYPE_ARGUMENT_PACK
2912 && TREE_CODE (t) != NONTYPE_ARGUMENT_PACK)
2915 return ARGUMENT_PACK_ARGS (t);
2918 /* Structure used to track the progress of find_parameter_packs_r. */
2919 struct find_parameter_pack_data
2921 /* TREE_LIST that will contain all of the parameter packs found by
2923 tree* parameter_packs;
2925 /* Set of AST nodes that have been visited by the traversal. */
2926 struct pointer_set_t *visited;
2929 /* Identifies all of the argument packs that occur in a template
2930 argument and appends them to the TREE_LIST inside DATA, which is a
2931 find_parameter_pack_data structure. This is a subroutine of
2932 make_pack_expansion and uses_parameter_packs. */
2934 find_parameter_packs_r (tree *tp, int *walk_subtrees, void* data)
2937 struct find_parameter_pack_data* ppd =
2938 (struct find_parameter_pack_data*)data;
2939 bool parameter_pack_p = false;
2941 /* Identify whether this is a parameter pack or not. */
2942 switch (TREE_CODE (t))
2944 case TEMPLATE_PARM_INDEX:
2945 if (TEMPLATE_PARM_PARAMETER_PACK (t))
2946 parameter_pack_p = true;
2949 case TEMPLATE_TYPE_PARM:
2950 case TEMPLATE_TEMPLATE_PARM:
2951 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
2952 parameter_pack_p = true;
2956 if (FUNCTION_PARAMETER_PACK_P (t))
2958 /* We don't want to walk into the type of a PARM_DECL,
2959 because we don't want to see the type parameter pack. */
2961 parameter_pack_p = true;
2966 /* Not a parameter pack. */
2970 if (parameter_pack_p)
2972 /* Add this parameter pack to the list. */
2973 *ppd->parameter_packs = tree_cons (NULL_TREE, t, *ppd->parameter_packs);
2977 cp_walk_tree (&TYPE_CONTEXT (t),
2978 &find_parameter_packs_r, ppd, ppd->visited);
2980 /* This switch statement will return immediately if we don't find a
2982 switch (TREE_CODE (t))
2984 case TEMPLATE_PARM_INDEX:
2987 case BOUND_TEMPLATE_TEMPLATE_PARM:
2988 /* Check the template itself. */
2989 cp_walk_tree (&TREE_TYPE (TYPE_TI_TEMPLATE (t)),
2990 &find_parameter_packs_r, ppd, ppd->visited);
2991 /* Check the template arguments. */
2992 cp_walk_tree (&TYPE_TI_ARGS (t), &find_parameter_packs_r, ppd,
2997 case TEMPLATE_TYPE_PARM:
2998 case TEMPLATE_TEMPLATE_PARM:
3005 if (TYPE_PTRMEMFUNC_P (t))
3011 if (TYPE_TEMPLATE_INFO (t))
3012 cp_walk_tree (&TI_ARGS (TYPE_TEMPLATE_INFO (t)),
3013 &find_parameter_packs_r, ppd, ppd->visited);
3019 cp_walk_tree (&TREE_TYPE (t),
3020 &find_parameter_packs_r, ppd, ppd->visited);
3024 cp_walk_tree (&TYPENAME_TYPE_FULLNAME (t), &find_parameter_packs_r,
3029 case TYPE_PACK_EXPANSION:
3030 case EXPR_PACK_EXPANSION:
3035 cp_walk_tree (&TYPE_MAX_VALUE (t), &find_parameter_packs_r,
3040 case IDENTIFIER_NODE:
3041 cp_walk_tree (&TREE_TYPE (t), &find_parameter_packs_r, ppd,
3053 /* Determines if the expression or type T uses any parameter packs. */
3055 uses_parameter_packs (tree t)
3057 tree parameter_packs = NULL_TREE;
3058 struct find_parameter_pack_data ppd;
3059 ppd.parameter_packs = ¶meter_packs;
3060 ppd.visited = pointer_set_create ();
3061 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
3062 pointer_set_destroy (ppd.visited);
3063 return parameter_packs != NULL_TREE;
3066 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3067 representation a base-class initializer into a parameter pack
3068 expansion. If all goes well, the resulting node will be an
3069 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3072 make_pack_expansion (tree arg)
3075 tree parameter_packs = NULL_TREE;
3076 bool for_types = false;
3077 struct find_parameter_pack_data ppd;
3079 if (!arg || arg == error_mark_node)
3082 if (TREE_CODE (arg) == TREE_LIST)
3084 /* The only time we will see a TREE_LIST here is for a base
3085 class initializer. In this case, the TREE_PURPOSE will be a
3086 _TYPE node (representing the base class expansion we're
3087 initializing) and the TREE_VALUE will be a TREE_LIST
3088 containing the initialization arguments.
3090 The resulting expansion looks somewhat different from most
3091 expansions. Rather than returning just one _EXPANSION, we
3092 return a TREE_LIST whose TREE_PURPOSE is a
3093 TYPE_PACK_EXPANSION containing the bases that will be
3094 initialized. The TREE_VALUE will be identical to the
3095 original TREE_VALUE, which is a list of arguments that will
3096 be passed to each base. We do not introduce any new pack
3097 expansion nodes into the TREE_VALUE (although it is possible
3098 that some already exist), because the TREE_PURPOSE and
3099 TREE_VALUE all need to be expanded together with the same
3100 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3101 resulting TREE_PURPOSE will mention the parameter packs in
3102 both the bases and the arguments to the bases. */
3105 tree parameter_packs = NULL_TREE;
3107 /* Determine which parameter packs will be used by the base
3109 ppd.visited = pointer_set_create ();
3110 ppd.parameter_packs = ¶meter_packs;
3111 cp_walk_tree (&TREE_PURPOSE (arg), &find_parameter_packs_r,
3114 if (parameter_packs == NULL_TREE)
3116 error ("base initializer expansion %<%T%> contains no parameter packs", arg);
3117 pointer_set_destroy (ppd.visited);
3118 return error_mark_node;
3121 if (TREE_VALUE (arg) != void_type_node)
3123 /* Collect the sets of parameter packs used in each of the
3124 initialization arguments. */
3125 for (value = TREE_VALUE (arg); value; value = TREE_CHAIN (value))
3127 /* Determine which parameter packs will be expanded in this
3129 cp_walk_tree (&TREE_VALUE (value), &find_parameter_packs_r,
3134 pointer_set_destroy (ppd.visited);
3136 /* Create the pack expansion type for the base type. */
3137 purpose = cxx_make_type (TYPE_PACK_EXPANSION);
3138 SET_PACK_EXPANSION_PATTERN (purpose, TREE_PURPOSE (arg));
3139 PACK_EXPANSION_PARAMETER_PACKS (purpose) = parameter_packs;
3141 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3142 they will rarely be compared to anything. */
3143 SET_TYPE_STRUCTURAL_EQUALITY (purpose);
3145 return tree_cons (purpose, TREE_VALUE (arg), NULL_TREE);
3148 if (TYPE_P (arg) || TREE_CODE (arg) == TEMPLATE_DECL)
3151 /* Build the PACK_EXPANSION_* node. */
3153 ? cxx_make_type (TYPE_PACK_EXPANSION)
3154 : make_node (EXPR_PACK_EXPANSION);
3155 SET_PACK_EXPANSION_PATTERN (result, arg);
3156 if (TREE_CODE (result) == EXPR_PACK_EXPANSION)
3158 /* Propagate type and const-expression information. */
3159 TREE_TYPE (result) = TREE_TYPE (arg);
3160 TREE_CONSTANT (result) = TREE_CONSTANT (arg);
3163 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3164 they will rarely be compared to anything. */
3165 SET_TYPE_STRUCTURAL_EQUALITY (result);
3167 /* Determine which parameter packs will be expanded. */
3168 ppd.parameter_packs = ¶meter_packs;
3169 ppd.visited = pointer_set_create ();
3170 cp_walk_tree (&arg, &find_parameter_packs_r, &ppd, ppd.visited);
3171 pointer_set_destroy (ppd.visited);
3173 /* Make sure we found some parameter packs. */
3174 if (parameter_packs == NULL_TREE)
3177 error ("expansion pattern %<%T%> contains no argument packs", arg);
3179 error ("expansion pattern %<%E%> contains no argument packs", arg);
3180 return error_mark_node;
3182 PACK_EXPANSION_PARAMETER_PACKS (result) = parameter_packs;
3187 /* Checks T for any "bare" parameter packs, which have not yet been
3188 expanded, and issues an error if any are found. This operation can
3189 only be done on full expressions or types (e.g., an expression
3190 statement, "if" condition, etc.), because we could have expressions like:
3192 foo(f(g(h(args)))...)
3194 where "args" is a parameter pack. check_for_bare_parameter_packs
3195 should not be called for the subexpressions args, h(args),
3196 g(h(args)), or f(g(h(args))), because we would produce erroneous
3199 Returns TRUE and emits an error if there were bare parameter packs,
3200 returns FALSE otherwise. */
3202 check_for_bare_parameter_packs (tree t)
3204 tree parameter_packs = NULL_TREE;
3205 struct find_parameter_pack_data ppd;
3207 if (!processing_template_decl || !t || t == error_mark_node)
3210 if (TREE_CODE (t) == TYPE_DECL)
3213 ppd.parameter_packs = ¶meter_packs;
3214 ppd.visited = pointer_set_create ();
3215 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
3216 pointer_set_destroy (ppd.visited);
3218 if (parameter_packs)
3220 error ("parameter packs not expanded with %<...%>:");
3221 while (parameter_packs)
3223 tree pack = TREE_VALUE (parameter_packs);
3224 tree name = NULL_TREE;
3226 if (TREE_CODE (pack) == TEMPLATE_TYPE_PARM
3227 || TREE_CODE (pack) == TEMPLATE_TEMPLATE_PARM)
3228 name = TYPE_NAME (pack);
3229 else if (TREE_CODE (pack) == TEMPLATE_PARM_INDEX)
3230 name = DECL_NAME (TEMPLATE_PARM_DECL (pack));
3232 name = DECL_NAME (pack);
3235 inform (input_location, " %qD", name);
3237 inform (input_location, " <anonymous>");
3239 parameter_packs = TREE_CHAIN (parameter_packs);
3248 /* Expand any parameter packs that occur in the template arguments in
3251 expand_template_argument_pack (tree args)
3253 tree result_args = NULL_TREE;
3254 int in_arg, out_arg = 0, nargs = args ? TREE_VEC_LENGTH (args) : 0;
3255 int num_result_args = -1;
3256 int non_default_args_count = -1;
3258 /* First, determine if we need to expand anything, and the number of
3259 slots we'll need. */
3260 for (in_arg = 0; in_arg < nargs; ++in_arg)
3262 tree arg = TREE_VEC_ELT (args, in_arg);
3263 if (arg == NULL_TREE)
3265 if (ARGUMENT_PACK_P (arg))
3267 int num_packed = TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg));
3268 if (num_result_args < 0)
3269 num_result_args = in_arg + num_packed;
3271 num_result_args += num_packed;
3275 if (num_result_args >= 0)
3280 /* If no expansion is necessary, we're done. */
3281 if (num_result_args < 0)
3284 /* Expand arguments. */
3285 result_args = make_tree_vec (num_result_args);
3286 if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (args))
3287 non_default_args_count =
3288 GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (args);
3289 for (in_arg = 0; in_arg < nargs; ++in_arg)
3291 tree arg = TREE_VEC_ELT (args, in_arg);
3292 if (ARGUMENT_PACK_P (arg))
3294 tree packed = ARGUMENT_PACK_ARGS (arg);
3295 int i, num_packed = TREE_VEC_LENGTH (packed);
3296 for (i = 0; i < num_packed; ++i, ++out_arg)
3297 TREE_VEC_ELT (result_args, out_arg) = TREE_VEC_ELT(packed, i);
3298 if (non_default_args_count > 0)
3299 non_default_args_count += num_packed;
3303 TREE_VEC_ELT (result_args, out_arg) = arg;
3307 if (non_default_args_count >= 0)
3308 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (result_args, non_default_args_count);
3312 /* Checks if DECL shadows a template parameter.
3314 [temp.local]: A template-parameter shall not be redeclared within its
3315 scope (including nested scopes).
3317 Emits an error and returns TRUE if the DECL shadows a parameter,
3318 returns FALSE otherwise. */
3321 check_template_shadow (tree decl)
3325 /* If we're not in a template, we can't possibly shadow a template
3327 if (!current_template_parms)
3330 /* Figure out what we're shadowing. */
3331 if (TREE_CODE (decl) == OVERLOAD)
3332 decl = OVL_CURRENT (decl);
3333 olddecl = innermost_non_namespace_value (DECL_NAME (decl));
3335 /* If there's no previous binding for this name, we're not shadowing
3336 anything, let alone a template parameter. */
3340 /* If we're not shadowing a template parameter, we're done. Note
3341 that OLDDECL might be an OVERLOAD (or perhaps even an
3342 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3344 if (!DECL_P (olddecl) || !DECL_TEMPLATE_PARM_P (olddecl))
3347 /* We check for decl != olddecl to avoid bogus errors for using a
3348 name inside a class. We check TPFI to avoid duplicate errors for
3349 inline member templates. */
3351 || TEMPLATE_PARMS_FOR_INLINE (current_template_parms))
3354 error ("declaration of %q+#D", decl);
3355 error (" shadows template parm %q+#D", olddecl);
3359 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3360 ORIG_LEVEL, DECL, and TYPE. NUM_SIBLINGS is the total number of
3361 template parameters. */
3364 build_template_parm_index (int index,
3371 tree t = make_node (TEMPLATE_PARM_INDEX);
3372 TEMPLATE_PARM_IDX (t) = index;
3373 TEMPLATE_PARM_LEVEL (t) = level;
3374 TEMPLATE_PARM_ORIG_LEVEL (t) = orig_level;
3375 TEMPLATE_PARM_NUM_SIBLINGS (t) = num_siblings;
3376 TEMPLATE_PARM_DECL (t) = decl;
3377 TREE_TYPE (t) = type;
3378 TREE_CONSTANT (t) = TREE_CONSTANT (decl);
3379 TREE_READONLY (t) = TREE_READONLY (decl);
3384 /* Find the canonical type parameter for the given template type
3385 parameter. Returns the canonical type parameter, which may be TYPE
3386 if no such parameter existed. */
3389 canonical_type_parameter (tree type)
3392 int idx = TEMPLATE_TYPE_IDX (type);
3393 if (!canonical_template_parms)
3394 canonical_template_parms = VEC_alloc (tree, gc, idx+1);
3396 while (VEC_length (tree, canonical_template_parms) <= (unsigned)idx)
3397 VEC_safe_push (tree, gc, canonical_template_parms, NULL_TREE);
3399 list = VEC_index (tree, canonical_template_parms, idx);
3400 while (list && !comptypes (type, TREE_VALUE (list), COMPARE_STRUCTURAL))
3401 list = TREE_CHAIN (list);
3404 return TREE_VALUE (list);
3407 VEC_replace(tree, canonical_template_parms, idx,
3408 tree_cons (NULL_TREE, type,
3409 VEC_index (tree, canonical_template_parms, idx)));
3414 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3415 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3416 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3417 new one is created. */
3420 reduce_template_parm_level (tree index, tree type, int levels, tree args,
3421 tsubst_flags_t complain)
3423 if (TEMPLATE_PARM_DESCENDANTS (index) == NULL_TREE
3424 || (TEMPLATE_PARM_LEVEL (TEMPLATE_PARM_DESCENDANTS (index))
3425 != TEMPLATE_PARM_LEVEL (index) - levels)
3426 || !same_type_p (type, TREE_TYPE (TEMPLATE_PARM_DESCENDANTS (index))))
3428 tree orig_decl = TEMPLATE_PARM_DECL (index);
3431 decl = build_decl (DECL_SOURCE_LOCATION (orig_decl),
3432 TREE_CODE (orig_decl), DECL_NAME (orig_decl), type);
3433 TREE_CONSTANT (decl) = TREE_CONSTANT (orig_decl);
3434 TREE_READONLY (decl) = TREE_READONLY (orig_decl);
3435 DECL_ARTIFICIAL (decl) = 1;
3436 SET_DECL_TEMPLATE_PARM_P (decl);
3438 t = build_template_parm_index (TEMPLATE_PARM_IDX (index),
3439 TEMPLATE_PARM_LEVEL (index) - levels,
3440 TEMPLATE_PARM_ORIG_LEVEL (index),
3441 TEMPLATE_PARM_NUM_SIBLINGS (index),
3443 TEMPLATE_PARM_DESCENDANTS (index) = t;
3444 TEMPLATE_PARM_PARAMETER_PACK (t)
3445 = TEMPLATE_PARM_PARAMETER_PACK (index);
3447 /* Template template parameters need this. */
3448 if (TREE_CODE (decl) == TEMPLATE_DECL)
3449 DECL_TEMPLATE_PARMS (decl) = tsubst_template_parms
3450 (DECL_TEMPLATE_PARMS (TEMPLATE_PARM_DECL (index)),
3454 return TEMPLATE_PARM_DESCENDANTS (index);
3457 /* Process information from new template parameter PARM and append it
3458 to the LIST being built. This new parameter is a non-type
3459 parameter iff IS_NON_TYPE is true. This new parameter is a
3460 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3461 is in PARM_LOC. NUM_TEMPLATE_PARMS is the size of the template
3462 parameter list PARM belongs to. This is used used to create a
3463 proper canonical type for the type of PARM that is to be created,
3464 iff PARM is a type. If the size is not known, this parameter shall
3468 process_template_parm (tree list, location_t parm_loc, tree parm,
3469 bool is_non_type, bool is_parameter_pack,
3470 unsigned num_template_parms)
3477 gcc_assert (TREE_CODE (parm) == TREE_LIST);
3478 defval = TREE_PURPOSE (parm);
3482 tree p = tree_last (list);
3484 if (p && TREE_VALUE (p) != error_mark_node)
3487 if (TREE_CODE (p) == TYPE_DECL || TREE_CODE (p) == TEMPLATE_DECL)
3488 idx = TEMPLATE_TYPE_IDX (TREE_TYPE (p));
3490 idx = TEMPLATE_PARM_IDX (DECL_INITIAL (p));
3500 parm = TREE_VALUE (parm);
3502 SET_DECL_TEMPLATE_PARM_P (parm);
3504 if (TREE_TYPE (parm) == error_mark_node)
3506 err_parm_list = build_tree_list (defval, parm);
3507 TREE_VALUE (err_parm_list) = error_mark_node;
3508 return chainon (list, err_parm_list);
3514 The top-level cv-qualifiers on the template-parameter are
3515 ignored when determining its type. */
3516 TREE_TYPE (parm) = TYPE_MAIN_VARIANT (TREE_TYPE (parm));
3517 if (invalid_nontype_parm_type_p (TREE_TYPE (parm), 1))
3519 err_parm_list = build_tree_list (defval, parm);
3520 TREE_VALUE (err_parm_list) = error_mark_node;
3521 return chainon (list, err_parm_list);
3524 if (uses_parameter_packs (TREE_TYPE (parm)) && !is_parameter_pack)
3526 /* This template parameter is not a parameter pack, but it
3527 should be. Complain about "bare" parameter packs. */
3528 check_for_bare_parameter_packs (TREE_TYPE (parm));
3530 /* Recover by calling this a parameter pack. */
3531 is_parameter_pack = true;
3535 /* A template parameter is not modifiable. */
3536 TREE_CONSTANT (parm) = 1;
3537 TREE_READONLY (parm) = 1;
3538 decl = build_decl (parm_loc,
3539 CONST_DECL, DECL_NAME (parm), TREE_TYPE (parm));
3540 TREE_CONSTANT (decl) = 1;
3541 TREE_READONLY (decl) = 1;
3542 DECL_INITIAL (parm) = DECL_INITIAL (decl)
3543 = build_template_parm_index (idx, processing_template_decl,
3544 processing_template_decl,
3546 decl, TREE_TYPE (parm));
3548 TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))
3549 = is_parameter_pack;
3554 parm = TREE_VALUE (TREE_VALUE (parm));
3556 if (parm && TREE_CODE (parm) == TEMPLATE_DECL)
3558 t = cxx_make_type (TEMPLATE_TEMPLATE_PARM);
3559 /* This is for distinguishing between real templates and template
3560 template parameters */
3561 TREE_TYPE (parm) = t;
3562 TREE_TYPE (DECL_TEMPLATE_RESULT (parm)) = t;
3567 t = cxx_make_type (TEMPLATE_TYPE_PARM);
3568 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3569 decl = build_decl (parm_loc,
3570 TYPE_DECL, parm, t);
3573 TYPE_NAME (t) = decl;
3574 TYPE_STUB_DECL (t) = decl;
3576 TEMPLATE_TYPE_PARM_INDEX (t)
3577 = build_template_parm_index (idx, processing_template_decl,
3578 processing_template_decl,
3580 decl, TREE_TYPE (parm));
3581 TEMPLATE_TYPE_PARAMETER_PACK (t) = is_parameter_pack;
3582 TYPE_CANONICAL (t) = canonical_type_parameter (t);
3584 DECL_ARTIFICIAL (decl) = 1;
3585 SET_DECL_TEMPLATE_PARM_P (decl);
3587 parm = build_tree_list (defval, parm);
3588 return chainon (list, parm);
3591 /* The end of a template parameter list has been reached. Process the
3592 tree list into a parameter vector, converting each parameter into a more
3593 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3597 end_template_parm_list (tree parms)
3601 tree saved_parmlist = make_tree_vec (list_length (parms));
3603 current_template_parms
3604 = tree_cons (size_int (processing_template_decl),
3605 saved_parmlist, current_template_parms);
3607 for (parm = parms, nparms = 0; parm; parm = next, nparms++)
3609 next = TREE_CHAIN (parm);
3610 TREE_VEC_ELT (saved_parmlist, nparms) = parm;
3611 TREE_CHAIN (parm) = NULL_TREE;
3614 --processing_template_parmlist;
3616 return saved_parmlist;
3619 /* Create a new type almost identical to TYPE but which has the
3620 following differences:
3622 1/ T has a new TEMPLATE_PARM_INDEX that carries the new number of
3623 template sibling parameters of T.
3625 2/ T has a new canonical type that matches the new number
3628 3/ From now on, T is going to be what lookups referring to the
3629 name of TYPE will return. No lookup should return TYPE anymore.
3631 NUM_PARMS is the new number of sibling parms TYPE belongs to.
3633 This is a subroutine of fixup_template_parms. */
3636 fixup_template_type_parm_type (tree type, int num_parms)
3638 tree orig_idx = TEMPLATE_TYPE_PARM_INDEX (type), idx;
3640 /* This is the decl which name is inserted into the symbol table for
3641 the template parm type. So whenever we lookup the type name, this
3642 is the DECL we get. */
3645 /* Do not fix up the type twice. */
3646 if (orig_idx && TEMPLATE_PARM_NUM_SIBLINGS (orig_idx) != 0)
3649 t = copy_type (type);
3650 decl = TYPE_NAME (t);
3652 TYPE_MAIN_VARIANT (t) = t;
3653 TYPE_NEXT_VARIANT (t)= NULL_TREE;
3654 TYPE_POINTER_TO (t) = 0;
3655 TYPE_REFERENCE_TO (t) = 0;
3657 idx = build_template_parm_index (TEMPLATE_PARM_IDX (orig_idx),
3658 TEMPLATE_PARM_LEVEL (orig_idx),
3659 TEMPLATE_PARM_ORIG_LEVEL (orig_idx),
3662 TEMPLATE_PARM_DESCENDANTS (idx) = TEMPLATE_PARM_DESCENDANTS (orig_idx);
3663 TEMPLATE_PARM_PARAMETER_PACK (idx) = TEMPLATE_PARM_PARAMETER_PACK (orig_idx);
3664 TEMPLATE_TYPE_PARM_INDEX (t) = idx;
3666 TYPE_STUB_DECL (t) = decl;
3667 TEMPLATE_TYPE_DECL (t) = decl;
3668 if (TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM)
3669 TREE_TYPE (DECL_TEMPLATE_RESULT (decl)) = t;
3671 /* Update the type associated to the type name stored in the symbol
3672 table. Now, whenever the type name is looked up, the resulting
3673 type is properly fixed up. */
3674 TREE_TYPE (decl) = t;
3676 TYPE_CANONICAL (t) = canonical_type_parameter (t);
3681 /* Create and return a new TEMPLATE_PARM_INDEX that is almost
3682 identical to I, but that is fixed up as to:
3684 1/ carry the number of sibling parms (NUM_PARMS) of the template
3685 parm represented by I.
3687 2/ replace all references to template parm types declared before I
3688 (in the same template parm list as I) by references to template
3689 parm types contained in ARGS. ARGS should contain the list of
3690 template parms that have been fixed up so far, in a form suitable
3691 to be passed to tsubst.
3693 This is a subroutine of fixup_template_parms. */
3696 fixup_template_parm_index (tree i, tree args, int num_parms)
3698 tree index, decl, type;
3701 || TREE_CODE (i) != TEMPLATE_PARM_INDEX
3702 /* Do not fix up the index twice. */
3703 || (TEMPLATE_PARM_NUM_SIBLINGS (i) != 0))
3706 decl = TEMPLATE_PARM_DECL (i);
3707 type = TREE_TYPE (decl);
3709 index = build_template_parm_index (TEMPLATE_PARM_IDX (i),
3710 TEMPLATE_PARM_LEVEL (i),
3711 TEMPLATE_PARM_ORIG_LEVEL (i),
3715 TEMPLATE_PARM_DESCENDANTS (index) = TEMPLATE_PARM_DESCENDANTS (i);
3716 TEMPLATE_PARM_PARAMETER_PACK (index) = TEMPLATE_PARM_PARAMETER_PACK (i);
3718 type = tsubst (type, args, tf_none, NULL_TREE);
3720 TREE_TYPE (decl) = type;
3721 TREE_TYPE (index) = type;
3727 This is a subroutine of fixup_template_parms.
3729 It computes the canonical type of the type of the template
3730 parameter PARM_DESC and update all references to that type so that
3731 they use the newly computed canonical type. No access check is
3732 performed during the fixup. PARM_DESC is a TREE_LIST which
3733 TREE_VALUE is the template parameter and its TREE_PURPOSE is the
3734 default argument of the template parm if any. IDX is the index of
3735 the template parameter, starting at 0. NUM_PARMS is the number of
3736 template parameters in the set PARM_DESC belongs to. ARGLIST is a
3737 TREE_VEC containing the full set of template parameters in a form
3738 suitable to be passed to substs functions as their ARGS
3739 argument. This is what current_template_args returns for a given
3740 template. The innermost vector of args in ARGLIST is the set of
3741 template parms that have been fixed up so far. This function adds
3742 the fixed up parameter into that vector. */
3745 fixup_template_parm (tree parm_desc,
3750 tree parm = TREE_VALUE (parm_desc);
3751 tree fixedup_args = INNERMOST_TEMPLATE_ARGS (arglist);
3753 push_deferring_access_checks (dk_no_check);
3755 if (TREE_CODE (parm) == TYPE_DECL)
3757 /* PARM is a template type parameter. Fix up its type, add
3758 the fixed-up template parm to the vector of fixed-up
3759 template parms so far, and substitute the fixed-up
3760 template parms into the default argument of this
3763 fixup_template_type_parm_type (TREE_TYPE (parm), num_parms);
3764 TREE_TYPE (parm) = t;
3766 TREE_VEC_ELT (fixedup_args, idx) = template_parm_to_arg (parm_desc);
3768 else if (TREE_CODE (parm) == TEMPLATE_DECL)
3770 /* PARM is a template template parameter. This is going to
3772 tree tparms, targs, innermost_args, t;
3775 /* First, fix up the parms of the template template parm
3776 because the parms are involved in defining the new canonical
3777 type of the template template parm. */
3779 /* So we need to substitute the template parm types that have
3780 been fixed up so far into the template parms of this template
3781 template parm. E.g, consider this:
3783 template<class T, template<T u> class TT> class S;
3785 In this case we want to substitute T into the
3786 template parameters of TT.
3788 So let's walk the template parms of PARM here, and
3789 tsubst ARGLIST into into each of the template
3792 /* For this substitution we need to build the full set of
3793 template parameters and use that as arguments for the
3794 tsubsting function. */
3795 tparms = INNERMOST_TEMPLATE_PARMS (DECL_TEMPLATE_PARMS (parm));
3797 /* This will contain the innermost parms of PARM into which
3798 we have substituted so far. */
3799 innermost_args = make_tree_vec (TREE_VEC_LENGTH (tparms));
3800 targs = add_to_template_args (arglist, innermost_args);
3801 for (j = 0; j < TREE_VEC_LENGTH (tparms); ++j)
3805 parameter = TREE_VEC_ELT (tparms, j);
3807 /* INNERMOST_ARGS needs to have at least the same number
3808 of elements as the index PARAMETER, ortherwise
3809 tsubsting into PARAMETER will result in partially
3810 instantiating it, reducing its tempate parm
3811 level. Let's tactically fill INNERMOST_ARGS for that
3813 TREE_VEC_ELT (innermost_args, j) =
3814 template_parm_to_arg (parameter);
3816 fixup_template_parm (parameter, j,
3817 TREE_VEC_LENGTH (tparms),
3821 /* Now fix up the type of the template template parm. */
3823 t = fixup_template_type_parm_type (TREE_TYPE (parm), num_parms);
3824 TREE_TYPE (parm) = t;
3826 TREE_VEC_ELT (fixedup_args, idx) =
3827 template_parm_to_arg (parm_desc);
3829 else if (TREE_CODE (parm) == PARM_DECL)
3831 /* PARM is a non-type template parameter. We need to:
3833 * Fix up its TEMPLATE_PARM_INDEX to make it carry the
3834 proper number of sibling parameters.
3836 * Make lookups of the template parameter return a reference
3837 to the fixed-up index. No lookup should return references
3838 to the former index anymore.
3840 * Substitute the template parms that got fixed up so far
3842 * into the type of PARM. */
3844 tree index = DECL_INITIAL (parm);
3846 /* PUSHED_DECL is the decl added to the symbol table with
3847 the name of the parameter. E,g:
3849 template<class T, T u> //#0
3850 auto my_function(T t) -> decltype(u); //#1
3852 Here, when looking up u at //#1, we get the decl of u
3853 resulting from the declaration in #0. This is what
3854 PUSHED_DECL is. We need to replace the reference to the
3855 old TEMPLATE_PARM_INDEX carried by PUSHED_DECL by the
3856 fixed-up TEMPLATE_PARM_INDEX. */
3857 tree pushed_decl = TEMPLATE_PARM_DECL (index);
3859 /* Let's fix up the TEMPLATE_PARM_INDEX then. Note that we must
3860 fixup the type of PUSHED_DECL as well and luckily
3861 fixup_template_parm_index does it for us too. */
3862 tree fixed_up_index =
3863 fixup_template_parm_index (index, arglist, num_parms);
3865 DECL_INITIAL (pushed_decl) = DECL_INITIAL (parm) = fixed_up_index;
3867 /* Add this fixed up PARM to the template parms we've fixed
3868 up so far and use that to substitute the fixed-up
3869 template parms into the type of PARM. */
3870 TREE_VEC_ELT (fixedup_args, idx) =
3871 template_parm_to_arg (parm_desc);
3872 TREE_TYPE (parm) = tsubst (TREE_TYPE (parm), arglist,
3873 tf_none, NULL_TREE);
3876 TREE_PURPOSE (parm_desc) =
3877 tsubst_template_arg (TREE_PURPOSE (parm_desc),
3878 arglist, tf_none, parm);
3880 pop_deferring_access_checks ();
3883 /* Walk the current template parms and properly compute the canonical
3884 types of the dependent types created during
3885 cp_parser_template_parameter_list. */
3888 fixup_template_parms (void)
3895 parameter_vec = INNERMOST_TEMPLATE_PARMS (current_template_parms);
3896 if (parameter_vec == NULL_TREE)
3899 num_parms = TREE_VEC_LENGTH (parameter_vec);
3901 /* This vector contains the current innermost template parms that
3902 have been fixed up so far. The form of FIXEDUP_ARGS is suitable
3903 to be passed to tsubst* functions as their ARGS argument. */
3904 fixedup_args = make_tree_vec (num_parms);
3906 /* This vector contains the full set of template parms in a form
3907 suitable to be passed to substs functions as their ARGS
3909 arglist = current_template_args ();
3910 arglist = add_outermost_template_args (arglist, fixedup_args);
3912 /* Let's do the proper fixup now. */
3913 for (i = 0; i < num_parms; ++i)
3914 fixup_template_parm (TREE_VEC_ELT (parameter_vec, i),
3915 i, num_parms, arglist);
3918 /* end_template_decl is called after a template declaration is seen. */
3921 end_template_decl (void)
3923 reset_specialization ();
3925 if (! processing_template_decl)
3928 /* This matches the pushlevel in begin_template_parm_list. */
3931 --processing_template_decl;
3932 current_template_parms = TREE_CHAIN (current_template_parms);
3935 /* Takes a TREE_LIST representing a template parameter and convert it
3936 into an argument suitable to be passed to the type substitution
3937 functions. Note that If the TREE_LIST contains an error_mark
3938 node, the returned argument is error_mark_node. */
3941 template_parm_to_arg (tree t)
3945 || TREE_CODE (t) != TREE_LIST)
3948 if (error_operand_p (TREE_VALUE (t)))
3949 return error_mark_node;
3953 if (TREE_CODE (t) == TYPE_DECL
3954 || TREE_CODE (t) == TEMPLATE_DECL)
3958 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
3960 /* Turn this argument into a TYPE_ARGUMENT_PACK
3961 with a single element, which expands T. */
3962 tree vec = make_tree_vec (1);
3963 #ifdef ENABLE_CHECKING
3964 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3965 (vec, TREE_VEC_LENGTH (vec));
3967 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
3969 t = cxx_make_type (TYPE_ARGUMENT_PACK);
3970 SET_ARGUMENT_PACK_ARGS (t, vec);
3975 t = DECL_INITIAL (t);
3977 if (TEMPLATE_PARM_PARAMETER_PACK (t))
3979 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3980 with a single element, which expands T. */
3981 tree vec = make_tree_vec (1);
3982 tree type = TREE_TYPE (TEMPLATE_PARM_DECL (t));
3983 #ifdef ENABLE_CHECKING
3984 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3985 (vec, TREE_VEC_LENGTH (vec));
3987 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
3989 t = make_node (NONTYPE_ARGUMENT_PACK);
3990 SET_ARGUMENT_PACK_ARGS (t, vec);
3991 TREE_TYPE (t) = type;
3997 /* Within the declaration of a template, return all levels of template
3998 parameters that apply. The template parameters are represented as
3999 a TREE_VEC, in the form documented in cp-tree.h for template
4003 current_template_args (void)
4006 tree args = NULL_TREE;
4007 int length = TMPL_PARMS_DEPTH (current_template_parms);
4010 /* If there is only one level of template parameters, we do not
4011 create a TREE_VEC of TREE_VECs. Instead, we return a single
4012 TREE_VEC containing the arguments. */
4014 args = make_tree_vec (length);
4016 for (header = current_template_parms; header; header = TREE_CHAIN (header))
4018 tree a = copy_node (TREE_VALUE (header));
4021 TREE_TYPE (a) = NULL_TREE;
4022 for (i = TREE_VEC_LENGTH (a) - 1; i >= 0; --i)
4023 TREE_VEC_ELT (a, i) = template_parm_to_arg (TREE_VEC_ELT (a, i));
4025 #ifdef ENABLE_CHECKING
4026 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (a, TREE_VEC_LENGTH (a));
4030 TREE_VEC_ELT (args, --l) = a;
4035 if (length > 1 && TREE_VEC_ELT (args, 0) == NULL_TREE)
4036 /* This can happen for template parms of a template template
4039 template<template<class T, class U> class TT> struct S;
4041 Consider the level of the parms of TT; T and U both have
4042 level 2; TT has no template parm of level 1. So in this case
4043 the first element of full_template_args is NULL_TREE. If we
4044 leave it like this TMPL_ARG_DEPTH on args returns 1 instead
4045 of 2. This will make tsubst wrongly consider that T and U
4046 have level 1. Instead, let's create a dummy vector as the
4047 first element of full_template_args so that TMPL_ARG_DEPTH
4048 returns the correct depth for args. */
4049 TREE_VEC_ELT (args, 0) = make_tree_vec (1);
4053 /* Update the declared TYPE by doing any lookups which were thought to be
4054 dependent, but are not now that we know the SCOPE of the declarator. */
4057 maybe_update_decl_type (tree orig_type, tree scope)
4059 tree type = orig_type;
4061 if (type == NULL_TREE)
4064 if (TREE_CODE (orig_type) == TYPE_DECL)
4065 type = TREE_TYPE (type);
4067 if (scope && TYPE_P (scope) && dependent_type_p (scope)
4068 && dependent_type_p (type)
4069 /* Don't bother building up the args in this case. */
4070 && TREE_CODE (type) != TEMPLATE_TYPE_PARM)
4072 /* tsubst in the args corresponding to the template parameters,
4073 including auto if present. Most things will be unchanged, but
4074 make_typename_type and tsubst_qualified_id will resolve
4075 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4076 tree args = current_template_args ();
4077 tree auto_node = type_uses_auto (type);
4081 tree auto_vec = make_tree_vec (1);
4082 TREE_VEC_ELT (auto_vec, 0) = auto_node;
4083 args = add_to_template_args (args, auto_vec);
4085 pushed = push_scope (scope);
4086 type = tsubst (type, args, tf_warning_or_error, NULL_TREE);
4091 if (type == error_mark_node)
4094 if (TREE_CODE (orig_type) == TYPE_DECL)
4096 if (same_type_p (type, TREE_TYPE (orig_type)))
4099 type = TYPE_NAME (type);
4104 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4105 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
4106 a member template. Used by push_template_decl below. */
4109 build_template_decl (tree decl, tree parms, bool member_template_p)
4111 tree tmpl = build_lang_decl (TEMPLATE_DECL, DECL_NAME (decl), NULL_TREE);
4112 DECL_TEMPLATE_PARMS (tmpl) = parms;
4113 DECL_CONTEXT (tmpl) = DECL_CONTEXT (decl);
4114 DECL_MEMBER_TEMPLATE_P (tmpl) = member_template_p;
4119 struct template_parm_data
4121 /* The level of the template parameters we are currently
4125 /* The index of the specialization argument we are currently
4129 /* An array whose size is the number of template parameters. The
4130 elements are nonzero if the parameter has been used in any one
4131 of the arguments processed so far. */
4134 /* An array whose size is the number of template arguments. The
4135 elements are nonzero if the argument makes use of template
4136 parameters of this level. */
4137 int* arg_uses_template_parms;
4140 /* Subroutine of push_template_decl used to see if each template
4141 parameter in a partial specialization is used in the explicit
4142 argument list. If T is of the LEVEL given in DATA (which is
4143 treated as a template_parm_data*), then DATA->PARMS is marked
4147 mark_template_parm (tree t, void* data)
4151 struct template_parm_data* tpd = (struct template_parm_data*) data;
4153 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
4155 level = TEMPLATE_PARM_LEVEL (t);
4156 idx = TEMPLATE_PARM_IDX (t);
4160 level = TEMPLATE_TYPE_LEVEL (t);
4161 idx = TEMPLATE_TYPE_IDX (t);
4164 if (level == tpd->level)
4166 tpd->parms[idx] = 1;
4167 tpd->arg_uses_template_parms[tpd->current_arg] = 1;
4170 /* Return zero so that for_each_template_parm will continue the
4171 traversal of the tree; we want to mark *every* template parm. */
4175 /* Process the partial specialization DECL. */
4178 process_partial_specialization (tree decl)
4180 tree type = TREE_TYPE (decl);
4181 tree maintmpl = CLASSTYPE_TI_TEMPLATE (type);
4182 tree specargs = CLASSTYPE_TI_ARGS (type);
4183 tree inner_args = INNERMOST_TEMPLATE_ARGS (specargs);
4184 tree main_inner_parms = DECL_INNERMOST_TEMPLATE_PARMS (maintmpl);
4187 int nargs = TREE_VEC_LENGTH (inner_args);
4190 bool did_error_intro = false;
4191 struct template_parm_data tpd;
4192 struct template_parm_data tpd2;
4194 gcc_assert (current_template_parms);
4196 inner_parms = INNERMOST_TEMPLATE_PARMS (current_template_parms);
4197 ntparms = TREE_VEC_LENGTH (inner_parms);
4199 /* We check that each of the template parameters given in the
4200 partial specialization is used in the argument list to the
4201 specialization. For example:
4203 template <class T> struct S;
4204 template <class T> struct S<T*>;
4206 The second declaration is OK because `T*' uses the template
4207 parameter T, whereas
4209 template <class T> struct S<int>;
4211 is no good. Even trickier is:
4222 The S2<T> declaration is actually invalid; it is a
4223 full-specialization. Of course,
4226 struct S2<T (*)(U)>;
4228 or some such would have been OK. */
4229 tpd.level = TMPL_PARMS_DEPTH (current_template_parms);
4230 tpd.parms = XALLOCAVEC (int, ntparms);
4231 memset (tpd.parms, 0, sizeof (int) * ntparms);
4233 tpd.arg_uses_template_parms = XALLOCAVEC (int, nargs);
4234 memset (tpd.arg_uses_template_parms, 0, sizeof (int) * nargs);
4235 for (i = 0; i < nargs; ++i)
4237 tpd.current_arg = i;
4238 for_each_template_parm (TREE_VEC_ELT (inner_args, i),
4239 &mark_template_parm,
4242 /*include_nondeduced_p=*/false);
4244 for (i = 0; i < ntparms; ++i)
4245 if (tpd.parms[i] == 0)
4247 /* One of the template parms was not used in the
4249 if (!did_error_intro)
4251 error ("template parameters not used in partial specialization:");
4252 did_error_intro = true;
4255 error (" %qD", TREE_VALUE (TREE_VEC_ELT (inner_parms, i)));
4258 if (did_error_intro)
4259 return error_mark_node;
4261 /* [temp.class.spec]
4263 The argument list of the specialization shall not be identical to
4264 the implicit argument list of the primary template. */
4265 if (comp_template_args
4267 INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE
4269 error ("partial specialization %qT does not specialize any template arguments", type);
4271 /* [temp.class.spec]
4273 A partially specialized non-type argument expression shall not
4274 involve template parameters of the partial specialization except
4275 when the argument expression is a simple identifier.
4277 The type of a template parameter corresponding to a specialized
4278 non-type argument shall not be dependent on a parameter of the
4281 Also, we verify that pack expansions only occur at the
4282 end of the argument list. */
4283 gcc_assert (nargs == DECL_NTPARMS (maintmpl));
4285 for (i = 0; i < nargs; ++i)
4287 tree parm = TREE_VALUE (TREE_VEC_ELT (main_inner_parms, i));
4288 tree arg = TREE_VEC_ELT (inner_args, i);
4289 tree packed_args = NULL_TREE;
4292 if (ARGUMENT_PACK_P (arg))
4294 /* Extract the arguments from the argument pack. We'll be
4295 iterating over these in the following loop. */
4296 packed_args = ARGUMENT_PACK_ARGS (arg);
4297 len = TREE_VEC_LENGTH (packed_args);
4300 for (j = 0; j < len; j++)
4303 /* Get the Jth argument in the parameter pack. */
4304 arg = TREE_VEC_ELT (packed_args, j);
4306 if (PACK_EXPANSION_P (arg))
4308 /* Pack expansions must come at the end of the
4310 if ((packed_args && j < len - 1)
4311 || (!packed_args && i < nargs - 1))
4313 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
4314 error ("parameter pack argument %qE must be at the "
4315 "end of the template argument list", arg);
4317 error ("parameter pack argument %qT must be at the "
4318 "end of the template argument list", arg);
4322 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
4323 /* We only care about the pattern. */
4324 arg = PACK_EXPANSION_PATTERN (arg);
4326 if (/* These first two lines are the `non-type' bit. */
4328 && TREE_CODE (arg) != TEMPLATE_DECL
4329 /* This next line is the `argument expression is not just a
4330 simple identifier' condition and also the `specialized
4331 non-type argument' bit. */
4332 && TREE_CODE (arg) != TEMPLATE_PARM_INDEX)
4334 if ((!packed_args && tpd.arg_uses_template_parms[i])
4335 || (packed_args && uses_template_parms (arg)))
4336 error ("template argument %qE involves template parameter(s)",
4340 /* Look at the corresponding template parameter,
4341 marking which template parameters its type depends
4343 tree type = TREE_TYPE (parm);
4347 /* We haven't yet initialized TPD2. Do so now. */
4348 tpd2.arg_uses_template_parms = XALLOCAVEC (int, nargs);
4349 /* The number of parameters here is the number in the
4350 main template, which, as checked in the assertion
4352 tpd2.parms = XALLOCAVEC (int, nargs);
4354 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (maintmpl));
4357 /* Mark the template parameters. But this time, we're
4358 looking for the template parameters of the main
4359 template, not in the specialization. */
4360 tpd2.current_arg = i;
4361 tpd2.arg_uses_template_parms[i] = 0;
4362 memset (tpd2.parms, 0, sizeof (int) * nargs);
4363 for_each_template_parm (type,
4364 &mark_template_parm,
4367 /*include_nondeduced_p=*/false);
4369 if (tpd2.arg_uses_template_parms [i])
4371 /* The type depended on some template parameters.
4372 If they are fully specialized in the
4373 specialization, that's OK. */
4376 for (j = 0; j < nargs; ++j)
4377 if (tpd2.parms[j] != 0
4378 && tpd.arg_uses_template_parms [j])
4381 error_n (input_location, count,
4382 "type %qT of template argument %qE depends "
4383 "on a template parameter",
4384 "type %qT of template argument %qE depends "
4385 "on template parameters",
4394 /* We should only get here once. */
4395 gcc_assert (!COMPLETE_TYPE_P (type));
4397 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)
4398 = tree_cons (specargs, inner_parms,
4399 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl));
4400 TREE_TYPE (DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)) = type;
4402 for (inst = DECL_TEMPLATE_INSTANTIATIONS (maintmpl); inst;
4403 inst = TREE_CHAIN (inst))
4405 tree inst_type = TREE_VALUE (inst);
4406 if (COMPLETE_TYPE_P (inst_type)
4407 && CLASSTYPE_IMPLICIT_INSTANTIATION (inst_type))
4409 tree spec = most_specialized_class (inst_type, maintmpl, tf_none);
4410 if (spec && TREE_TYPE (spec) == type)
4411 permerror (input_location,
4412 "partial specialization of %qT after instantiation "
4413 "of %qT", type, inst_type);
4420 /* Check that a template declaration's use of default arguments and
4421 parameter packs is not invalid. Here, PARMS are the template
4422 parameters. IS_PRIMARY is nonzero if DECL is the thing declared by
4423 a primary template. IS_PARTIAL is nonzero if DECL is a partial
4427 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4428 declaration (but not a definition); 1 indicates a declaration, 2
4429 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4430 emitted for extraneous default arguments.
4432 Returns TRUE if there were no errors found, FALSE otherwise. */
4435 check_default_tmpl_args (tree decl, tree parms, int is_primary,
4436 int is_partial, int is_friend_decl)
4439 int last_level_to_check;
4441 bool no_errors = true;
4445 A default template-argument shall not be specified in a
4446 function template declaration or a function template definition, nor
4447 in the template-parameter-list of the definition of a member of a
4450 if (TREE_CODE (CP_DECL_CONTEXT (decl)) == FUNCTION_DECL)
4451 /* You can't have a function template declaration in a local
4452 scope, nor you can you define a member of a class template in a
4456 if (current_class_type
4457 && !TYPE_BEING_DEFINED (current_class_type)
4458 && DECL_LANG_SPECIFIC (decl)
4459 && DECL_DECLARES_FUNCTION_P (decl)
4460 /* If this is either a friend defined in the scope of the class
4461 or a member function. */
4462 && (DECL_FUNCTION_MEMBER_P (decl)
4463 ? same_type_p (DECL_CONTEXT (decl), current_class_type)
4464 : DECL_FRIEND_CONTEXT (decl)
4465 ? same_type_p (DECL_FRIEND_CONTEXT (decl), current_class_type)
4467 /* And, if it was a member function, it really was defined in
4468 the scope of the class. */
4469 && (!DECL_FUNCTION_MEMBER_P (decl)
4470 || DECL_INITIALIZED_IN_CLASS_P (decl)))
4471 /* We already checked these parameters when the template was
4472 declared, so there's no need to do it again now. This function
4473 was defined in class scope, but we're processing it's body now
4474 that the class is complete. */
4477 /* Core issue 226 (C++0x only): the following only applies to class
4479 if ((cxx_dialect == cxx98) || TREE_CODE (decl) != FUNCTION_DECL)
4483 If a template-parameter has a default template-argument, all
4484 subsequent template-parameters shall have a default
4485 template-argument supplied. */
4486 for (parm_level = parms; parm_level; parm_level = TREE_CHAIN (parm_level))
4488 tree inner_parms = TREE_VALUE (parm_level);
4489 int ntparms = TREE_VEC_LENGTH (inner_parms);
4490 int seen_def_arg_p = 0;
4493 for (i = 0; i < ntparms; ++i)
4495 tree parm = TREE_VEC_ELT (inner_parms, i);
4497 if (parm == error_mark_node)
4500 if (TREE_PURPOSE (parm))
4502 else if (seen_def_arg_p
4503 && !template_parameter_pack_p (TREE_VALUE (parm)))
4505 error ("no default argument for %qD", TREE_VALUE (parm));
4506 /* For better subsequent error-recovery, we indicate that
4507 there should have been a default argument. */
4508 TREE_PURPOSE (parm) = error_mark_node;
4514 /* Don't complain about an enclosing partial
4516 && parm_level == parms
4517 && TREE_CODE (decl) == TYPE_DECL
4519 && template_parameter_pack_p (TREE_VALUE (parm)))
4521 /* A primary class template can only have one
4522 parameter pack, at the end of the template
4525 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL)
4526 error ("parameter pack %qE must be at the end of the"
4527 " template parameter list", TREE_VALUE (parm));
4529 error ("parameter pack %qT must be at the end of the"
4530 " template parameter list",
4531 TREE_TYPE (TREE_VALUE (parm)));
4533 TREE_VALUE (TREE_VEC_ELT (inner_parms, i))
4541 if (((cxx_dialect == cxx98) && TREE_CODE (decl) != TYPE_DECL)
4545 /* For an ordinary class template, default template arguments are
4546 allowed at the innermost level, e.g.:
4547 template <class T = int>
4549 but, in a partial specialization, they're not allowed even
4550 there, as we have in [temp.class.spec]:
4552 The template parameter list of a specialization shall not
4553 contain default template argument values.
4555 So, for a partial specialization, or for a function template
4556 (in C++98/C++03), we look at all of them. */
4559 /* But, for a primary class template that is not a partial
4560 specialization we look at all template parameters except the
4562 parms = TREE_CHAIN (parms);
4564 /* Figure out what error message to issue. */
4565 if (is_friend_decl == 2)
4566 msg = G_("default template arguments may not be used in function template "
4567 "friend re-declaration");
4568 else if (is_friend_decl)
4569 msg = G_("default template arguments may not be used in function template "
4570 "friend declarations");
4571 else if (TREE_CODE (decl) == FUNCTION_DECL && (cxx_dialect == cxx98))
4572 msg = G_("default template arguments may not be used in function templates "
4573 "without -std=c++0x or -std=gnu++0x");
4574 else if (is_partial)
4575 msg = G_("default template arguments may not be used in "
4576 "partial specializations");
4578 msg = G_("default argument for template parameter for class enclosing %qD");
4580 if (current_class_type && TYPE_BEING_DEFINED (current_class_type))
4581 /* If we're inside a class definition, there's no need to
4582 examine the parameters to the class itself. On the one
4583 hand, they will be checked when the class is defined, and,
4584 on the other, default arguments are valid in things like:
4585 template <class T = double>
4586 struct S { template <class U> void f(U); };
4587 Here the default argument for `S' has no bearing on the
4588 declaration of `f'. */
4589 last_level_to_check = template_class_depth (current_class_type) + 1;
4591 /* Check everything. */
4592 last_level_to_check = 0;
4594 for (parm_level = parms;
4595 parm_level && TMPL_PARMS_DEPTH (parm_level) >= last_level_to_check;
4596 parm_level = TREE_CHAIN (parm_level))
4598 tree inner_parms = TREE_VALUE (parm_level);
4602 ntparms = TREE_VEC_LENGTH (inner_parms);
4603 for (i = 0; i < ntparms; ++i)
4605 if (TREE_VEC_ELT (inner_parms, i) == error_mark_node)
4608 if (TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)))
4613 if (is_friend_decl == 2)
4620 /* Clear out the default argument so that we are not
4622 TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)) = NULL_TREE;
4626 /* At this point, if we're still interested in issuing messages,
4627 they must apply to classes surrounding the object declared. */
4629 msg = G_("default argument for template parameter for class "
4636 /* Worker for push_template_decl_real, called via
4637 for_each_template_parm. DATA is really an int, indicating the
4638 level of the parameters we are interested in. If T is a template
4639 parameter of that level, return nonzero. */
4642 template_parm_this_level_p (tree t, void* data)
4644 int this_level = *(int *)data;
4647 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
4648 level = TEMPLATE_PARM_LEVEL (t);
4650 level = TEMPLATE_TYPE_LEVEL (t);
4651 return level == this_level;
4654 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4655 parameters given by current_template_args, or reuses a
4656 previously existing one, if appropriate. Returns the DECL, or an
4657 equivalent one, if it is replaced via a call to duplicate_decls.
4659 If IS_FRIEND is true, DECL is a friend declaration. */
4662 push_template_decl_real (tree decl, bool is_friend)
4670 int new_template_p = 0;
4671 /* True if the template is a member template, in the sense of
4673 bool member_template_p = false;
4675 if (decl == error_mark_node || !current_template_parms)
4676 return error_mark_node;
4678 /* See if this is a partial specialization. */
4679 is_partial = (DECL_IMPLICIT_TYPEDEF_P (decl)
4680 && TREE_CODE (TREE_TYPE (decl)) != ENUMERAL_TYPE
4681 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)));
4683 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_FRIEND_P (decl))
4687 /* For a friend, we want the context of the friend function, not
4688 the type of which it is a friend. */
4689 ctx = CP_DECL_CONTEXT (decl);
4690 else if (CP_DECL_CONTEXT (decl)
4691 && TREE_CODE (CP_DECL_CONTEXT (decl)) != NAMESPACE_DECL)
4692 /* In the case of a virtual function, we want the class in which
4694 ctx = CP_DECL_CONTEXT (decl);
4696 /* Otherwise, if we're currently defining some class, the DECL
4697 is assumed to be a member of the class. */
4698 ctx = current_scope ();
4700 if (ctx && TREE_CODE (ctx) == NAMESPACE_DECL)
4703 if (!DECL_CONTEXT (decl))
4704 DECL_CONTEXT (decl) = FROB_CONTEXT (current_namespace);
4706 /* See if this is a primary template. */
4707 if (is_friend && ctx)
4708 /* A friend template that specifies a class context, i.e.
4709 template <typename T> friend void A<T>::f();
4713 primary = template_parm_scope_p ();
4717 if (DECL_CLASS_SCOPE_P (decl))
4718 member_template_p = true;
4719 if (TREE_CODE (decl) == TYPE_DECL
4720 && ANON_AGGRNAME_P (DECL_NAME (decl)))
4722 error ("template class without a name");
4723 return error_mark_node;
4725 else if (TREE_CODE (decl) == FUNCTION_DECL)
4727 if (DECL_DESTRUCTOR_P (decl))
4731 A destructor shall not be a member template. */
4732 error ("destructor %qD declared as member template", decl);
4733 return error_mark_node;
4735 if (NEW_DELETE_OPNAME_P (DECL_NAME (decl))
4736 && (!prototype_p (TREE_TYPE (decl))
4737 || TYPE_ARG_TYPES (TREE_TYPE (decl)) == void_list_node
4738 || !TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (decl)))
4739 || (TREE_CHAIN (TYPE_ARG_TYPES ((TREE_TYPE (decl))))
4740 == void_list_node)))
4742 /* [basic.stc.dynamic.allocation]
4744 An allocation function can be a function
4745 template. ... Template allocation functions shall
4746 have two or more parameters. */
4747 error ("invalid template declaration of %qD", decl);
4748 return error_mark_node;
4751 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4752 && CLASS_TYPE_P (TREE_TYPE (decl)))
4756 error ("template declaration of %q#D", decl);
4757 return error_mark_node;
4761 /* Check to see that the rules regarding the use of default
4762 arguments are not being violated. */
4763 check_default_tmpl_args (decl, current_template_parms,
4764 primary, is_partial, /*is_friend_decl=*/0);
4766 /* Ensure that there are no parameter packs in the type of this
4767 declaration that have not been expanded. */
4768 if (TREE_CODE (decl) == FUNCTION_DECL)
4770 /* Check each of the arguments individually to see if there are
4771 any bare parameter packs. */
4772 tree type = TREE_TYPE (decl);
4773 tree arg = DECL_ARGUMENTS (decl);
4774 tree argtype = TYPE_ARG_TYPES (type);
4776 while (arg && argtype)
4778 if (!FUNCTION_PARAMETER_PACK_P (arg)
4779 && check_for_bare_parameter_packs (TREE_TYPE (arg)))
4781 /* This is a PARM_DECL that contains unexpanded parameter
4782 packs. We have already complained about this in the
4783 check_for_bare_parameter_packs call, so just replace
4784 these types with ERROR_MARK_NODE. */
4785 TREE_TYPE (arg) = error_mark_node;
4786 TREE_VALUE (argtype) = error_mark_node;
4789 arg = DECL_CHAIN (arg);
4790 argtype = TREE_CHAIN (argtype);
4793 /* Check for bare parameter packs in the return type and the
4794 exception specifiers. */
4795 if (check_for_bare_parameter_packs (TREE_TYPE (type)))
4796 /* Errors were already issued, set return type to int
4797 as the frontend doesn't expect error_mark_node as
4799 TREE_TYPE (type) = integer_type_node;
4800 if (check_for_bare_parameter_packs (TYPE_RAISES_EXCEPTIONS (type)))
4801 TYPE_RAISES_EXCEPTIONS (type) = NULL_TREE;
4803 else if (check_for_bare_parameter_packs (TREE_TYPE (decl)))
4805 TREE_TYPE (decl) = error_mark_node;
4806 return error_mark_node;
4810 return process_partial_specialization (decl);
4812 args = current_template_args ();
4815 || TREE_CODE (ctx) == FUNCTION_DECL
4816 || (CLASS_TYPE_P (ctx) && TYPE_BEING_DEFINED (ctx))
4817 || (is_friend && !DECL_TEMPLATE_INFO (decl)))
4819 if (DECL_LANG_SPECIFIC (decl)
4820 && DECL_TEMPLATE_INFO (decl)
4821 && DECL_TI_TEMPLATE (decl))
4822 tmpl = DECL_TI_TEMPLATE (decl);
4823 /* If DECL is a TYPE_DECL for a class-template, then there won't
4824 be DECL_LANG_SPECIFIC. The information equivalent to
4825 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4826 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4827 && TYPE_TEMPLATE_INFO (TREE_TYPE (decl))
4828 && TYPE_TI_TEMPLATE (TREE_TYPE (decl)))
4830 /* Since a template declaration already existed for this
4831 class-type, we must be redeclaring it here. Make sure
4832 that the redeclaration is valid. */
4833 redeclare_class_template (TREE_TYPE (decl),
4834 current_template_parms);
4835 /* We don't need to create a new TEMPLATE_DECL; just use the
4836 one we already had. */
4837 tmpl = TYPE_TI_TEMPLATE (TREE_TYPE (decl));
4841 tmpl = build_template_decl (decl, current_template_parms,
4845 if (DECL_LANG_SPECIFIC (decl)
4846 && DECL_TEMPLATE_SPECIALIZATION (decl))
4848 /* A specialization of a member template of a template
4850 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
4851 DECL_TEMPLATE_INFO (tmpl) = DECL_TEMPLATE_INFO (decl);
4852 DECL_TEMPLATE_INFO (decl) = NULL_TREE;
4858 tree a, t, current, parms;
4860 tree tinfo = get_template_info (decl);
4864 error ("template definition of non-template %q#D", decl);
4865 return error_mark_node;
4868 tmpl = TI_TEMPLATE (tinfo);
4870 if (DECL_FUNCTION_TEMPLATE_P (tmpl)
4871 && DECL_TEMPLATE_INFO (decl) && DECL_TI_ARGS (decl)
4872 && DECL_TEMPLATE_SPECIALIZATION (decl)
4873 && DECL_MEMBER_TEMPLATE_P (tmpl))
4877 /* The declaration is a specialization of a member
4878 template, declared outside the class. Therefore, the
4879 innermost template arguments will be NULL, so we
4880 replace them with the arguments determined by the
4881 earlier call to check_explicit_specialization. */
4882 args = DECL_TI_ARGS (decl);
4885 = build_template_decl (decl, current_template_parms,
4887 DECL_TEMPLATE_RESULT (new_tmpl) = decl;
4888 TREE_TYPE (new_tmpl) = TREE_TYPE (decl);
4889 DECL_TI_TEMPLATE (decl) = new_tmpl;
4890 SET_DECL_TEMPLATE_SPECIALIZATION (new_tmpl);
4891 DECL_TEMPLATE_INFO (new_tmpl)
4892 = build_template_info (tmpl, args);
4894 register_specialization (new_tmpl,
4895 most_general_template (tmpl),
4901 /* Make sure the template headers we got make sense. */
4903 parms = DECL_TEMPLATE_PARMS (tmpl);
4904 i = TMPL_PARMS_DEPTH (parms);
4905 if (TMPL_ARGS_DEPTH (args) != i)
4907 error ("expected %d levels of template parms for %q#D, got %d",
4908 i, decl, TMPL_ARGS_DEPTH (args));
4911 for (current = decl; i > 0; --i, parms = TREE_CHAIN (parms))
4913 a = TMPL_ARGS_LEVEL (args, i);
4914 t = INNERMOST_TEMPLATE_PARMS (parms);
4916 if (TREE_VEC_LENGTH (t) != TREE_VEC_LENGTH (a))
4918 if (current == decl)
4919 error ("got %d template parameters for %q#D",
4920 TREE_VEC_LENGTH (a), decl);
4922 error ("got %d template parameters for %q#T",
4923 TREE_VEC_LENGTH (a), current);
4924 error (" but %d required", TREE_VEC_LENGTH (t));
4925 return error_mark_node;
4928 if (current == decl)
4930 else if (current == NULL_TREE)
4931 /* Can happen in erroneous input. */
4934 current = (TYPE_P (current)
4935 ? TYPE_CONTEXT (current)
4936 : DECL_CONTEXT (current));
4939 /* Check that the parms are used in the appropriate qualifying scopes
4940 in the declarator. */
4941 if (!comp_template_args
4943 TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (tmpl)))))
4946 template arguments to %qD do not match original template %qD",
4947 decl, DECL_TEMPLATE_RESULT (tmpl));
4948 if (!uses_template_parms (TI_ARGS (tinfo)))
4949 inform (input_location, "use template<> for an explicit specialization");
4950 /* Avoid crash in import_export_decl. */
4951 DECL_INTERFACE_KNOWN (decl) = 1;
4952 return error_mark_node;
4956 DECL_TEMPLATE_RESULT (tmpl) = decl;
4957 TREE_TYPE (tmpl) = TREE_TYPE (decl);
4959 /* Push template declarations for global functions and types. Note
4960 that we do not try to push a global template friend declared in a
4961 template class; such a thing may well depend on the template
4962 parameters of the class. */
4963 if (new_template_p && !ctx
4964 && !(is_friend && template_class_depth (current_class_type) > 0))
4966 tmpl = pushdecl_namespace_level (tmpl, is_friend);
4967 if (tmpl == error_mark_node)
4968 return error_mark_node;
4970 /* Hide template friend classes that haven't been declared yet. */
4971 if (is_friend && TREE_CODE (decl) == TYPE_DECL)
4973 DECL_ANTICIPATED (tmpl) = 1;
4974 DECL_FRIEND_P (tmpl) = 1;
4980 tree parms = DECL_TEMPLATE_PARMS (tmpl);
4983 DECL_PRIMARY_TEMPLATE (tmpl) = tmpl;
4984 if (DECL_CONV_FN_P (tmpl))
4986 int depth = TMPL_PARMS_DEPTH (parms);
4988 /* It is a conversion operator. See if the type converted to
4989 depends on innermost template operands. */
4991 if (uses_template_parms_level (TREE_TYPE (TREE_TYPE (tmpl)),
4993 DECL_TEMPLATE_CONV_FN_P (tmpl) = 1;
4996 /* Give template template parms a DECL_CONTEXT of the template
4997 for which they are a parameter. */
4998 parms = INNERMOST_TEMPLATE_PARMS (parms);
4999 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
5001 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
5002 if (TREE_CODE (parm) == TEMPLATE_DECL)
5003 DECL_CONTEXT (parm) = tmpl;
5007 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5008 back to its most general template. If TMPL is a specialization,
5009 ARGS may only have the innermost set of arguments. Add the missing
5010 argument levels if necessary. */
5011 if (DECL_TEMPLATE_INFO (tmpl))
5012 args = add_outermost_template_args (DECL_TI_ARGS (tmpl), args);
5014 info = build_template_info (tmpl, args);
5016 if (DECL_IMPLICIT_TYPEDEF_P (decl))
5017 SET_TYPE_TEMPLATE_INFO (TREE_TYPE (tmpl), info);
5018 else if (DECL_LANG_SPECIFIC (decl))
5019 DECL_TEMPLATE_INFO (decl) = info;
5021 return DECL_TEMPLATE_RESULT (tmpl);
5025 push_template_decl (tree decl)
5027 return push_template_decl_real (decl, false);
5030 /* Called when a class template TYPE is redeclared with the indicated
5031 template PARMS, e.g.:
5033 template <class T> struct S;
5034 template <class T> struct S {}; */
5037 redeclare_class_template (tree type, tree parms)
5043 if (!TYPE_TEMPLATE_INFO (type))
5045 error ("%qT is not a template type", type);
5049 tmpl = TYPE_TI_TEMPLATE (type);
5050 if (!PRIMARY_TEMPLATE_P (tmpl))
5051 /* The type is nested in some template class. Nothing to worry
5052 about here; there are no new template parameters for the nested
5058 error ("template specifiers not specified in declaration of %qD",
5063 parms = INNERMOST_TEMPLATE_PARMS (parms);
5064 tmpl_parms = DECL_INNERMOST_TEMPLATE_PARMS (tmpl);
5066 if (TREE_VEC_LENGTH (parms) != TREE_VEC_LENGTH (tmpl_parms))
5068 error_n (input_location, TREE_VEC_LENGTH (parms),
5069 "redeclared with %d template parameter",
5070 "redeclared with %d template parameters",
5071 TREE_VEC_LENGTH (parms));
5072 inform_n (input_location, TREE_VEC_LENGTH (tmpl_parms),
5073 "previous declaration %q+D used %d template parameter",
5074 "previous declaration %q+D used %d template parameters",
5075 tmpl, TREE_VEC_LENGTH (tmpl_parms));
5079 for (i = 0; i < TREE_VEC_LENGTH (tmpl_parms); ++i)
5086 if (TREE_VEC_ELT (tmpl_parms, i) == error_mark_node
5087 || TREE_VEC_ELT (parms, i) == error_mark_node)
5090 tmpl_parm = TREE_VALUE (TREE_VEC_ELT (tmpl_parms, i));
5091 if (tmpl_parm == error_mark_node)
5094 parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
5095 tmpl_default = TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i));
5096 parm_default = TREE_PURPOSE (TREE_VEC_ELT (parms, i));
5098 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5100 if (TREE_CODE (tmpl_parm) != TREE_CODE (parm)
5101 || (TREE_CODE (tmpl_parm) != TYPE_DECL
5102 && !same_type_p (TREE_TYPE (tmpl_parm), TREE_TYPE (parm)))
5103 || (TREE_CODE (tmpl_parm) != PARM_DECL
5104 && (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (tmpl_parm))
5105 != TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm))))
5106 || (TREE_CODE (tmpl_parm) == PARM_DECL
5107 && (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (tmpl_parm))
5108 != TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))))
5110 error ("template parameter %q+#D", tmpl_parm);
5111 error ("redeclared here as %q#D", parm);
5115 if (tmpl_default != NULL_TREE && parm_default != NULL_TREE)
5117 /* We have in [temp.param]:
5119 A template-parameter may not be given default arguments
5120 by two different declarations in the same scope. */
5121 error_at (input_location, "redefinition of default argument for %q#D", parm);
5122 inform (DECL_SOURCE_LOCATION (tmpl_parm),
5123 "original definition appeared here");
5127 if (parm_default != NULL_TREE)
5128 /* Update the previous template parameters (which are the ones
5129 that will really count) with the new default value. */
5130 TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i)) = parm_default;
5131 else if (tmpl_default != NULL_TREE)
5132 /* Update the new parameters, too; they'll be used as the
5133 parameters for any members. */
5134 TREE_PURPOSE (TREE_VEC_ELT (parms, i)) = tmpl_default;
5140 /* Simplify EXPR if it is a non-dependent expression. Returns the
5141 (possibly simplified) expression. */
5144 fold_non_dependent_expr_sfinae (tree expr, tsubst_flags_t complain)
5146 if (expr == NULL_TREE)
5149 /* If we're in a template, but EXPR isn't value dependent, simplify
5150 it. We're supposed to treat:
5152 template <typename T> void f(T[1 + 1]);
5153 template <typename T> void f(T[2]);
5155 as two declarations of the same function, for example. */
5156 if (processing_template_decl
5157 && !type_dependent_expression_p (expr)
5158 && potential_constant_expression (expr)
5159 && !value_dependent_expression_p (expr))
5161 HOST_WIDE_INT saved_processing_template_decl;
5163 saved_processing_template_decl = processing_template_decl;
5164 processing_template_decl = 0;
5165 expr = tsubst_copy_and_build (expr,
5168 /*in_decl=*/NULL_TREE,
5169 /*function_p=*/false,
5170 /*integral_constant_expression_p=*/true);
5171 processing_template_decl = saved_processing_template_decl;
5177 fold_non_dependent_expr (tree expr)
5179 return fold_non_dependent_expr_sfinae (expr, tf_error);
5182 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5183 must be a function or a pointer-to-function type, as specified
5184 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5185 and check that the resulting function has external linkage. */
5188 convert_nontype_argument_function (tree type, tree expr)
5193 fn = instantiate_type (type, fns, tf_none);
5194 if (fn == error_mark_node)
5195 return error_mark_node;
5198 if (TREE_CODE (fn_no_ptr) == ADDR_EXPR)
5199 fn_no_ptr = TREE_OPERAND (fn_no_ptr, 0);
5200 if (TREE_CODE (fn_no_ptr) == BASELINK)
5201 fn_no_ptr = BASELINK_FUNCTIONS (fn_no_ptr);
5203 /* [temp.arg.nontype]/1
5205 A template-argument for a non-type, non-template template-parameter
5208 -- the address of an object or function with external linkage. */
5209 if (!DECL_EXTERNAL_LINKAGE_P (fn_no_ptr))
5211 error ("%qE is not a valid template argument for type %qT "
5212 "because function %qD has not external linkage",
5213 expr, type, fn_no_ptr);
5220 /* Subroutine of convert_nontype_argument.
5221 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5222 Emit an error otherwise. */
5225 check_valid_ptrmem_cst_expr (tree type, tree expr,
5226 tsubst_flags_t complain)
5229 if (expr && (null_ptr_cst_p (expr) || TREE_CODE (expr) == PTRMEM_CST))
5231 if (complain & tf_error)
5233 error ("%qE is not a valid template argument for type %qT",
5235 error ("it must be a pointer-to-member of the form %<&X::Y%>");
5240 /* Returns TRUE iff the address of OP is value-dependent.
5242 14.6.2.4 [temp.dep.temp]:
5243 A non-integral non-type template-argument is dependent if its type is
5244 dependent or it has either of the following forms
5247 and contains a nested-name-specifier which specifies a class-name that
5248 names a dependent type.
5250 We generalize this to just say that the address of a member of a
5251 dependent class is value-dependent; the above doesn't cover the
5252 address of a static data member named with an unqualified-id. */
5255 has_value_dependent_address (tree op)
5257 /* We could use get_inner_reference here, but there's no need;
5258 this is only relevant for template non-type arguments, which
5259 can only be expressed as &id-expression. */
5262 tree ctx = CP_DECL_CONTEXT (op);
5263 if (TYPE_P (ctx) && dependent_type_p (ctx))
5270 /* Attempt to convert the non-type template parameter EXPR to the
5271 indicated TYPE. If the conversion is successful, return the
5272 converted value. If the conversion is unsuccessful, return
5273 NULL_TREE if we issued an error message, or error_mark_node if we
5274 did not. We issue error messages for out-and-out bad template
5275 parameters, but not simply because the conversion failed, since we
5276 might be just trying to do argument deduction. Both TYPE and EXPR
5277 must be non-dependent.
5279 The conversion follows the special rules described in
5280 [temp.arg.nontype], and it is much more strict than an implicit
5283 This function is called twice for each template argument (see
5284 lookup_template_class for a more accurate description of this
5285 problem). This means that we need to handle expressions which
5286 are not valid in a C++ source, but can be created from the
5287 first call (for instance, casts to perform conversions). These
5288 hacks can go away after we fix the double coercion problem. */
5291 convert_nontype_argument (tree type, tree expr, tsubst_flags_t complain)
5295 /* Detect immediately string literals as invalid non-type argument.
5296 This special-case is not needed for correctness (we would easily
5297 catch this later), but only to provide better diagnostic for this
5298 common user mistake. As suggested by DR 100, we do not mention
5299 linkage issues in the diagnostic as this is not the point. */
5300 /* FIXME we're making this OK. */
5301 if (TREE_CODE (expr) == STRING_CST)
5303 if (complain & tf_error)
5304 error ("%qE is not a valid template argument for type %qT "
5305 "because string literals can never be used in this context",
5310 /* Add the ADDR_EXPR now for the benefit of
5311 value_dependent_expression_p. */
5312 if (TYPE_PTROBV_P (type)
5313 && TREE_CODE (TREE_TYPE (expr)) == ARRAY_TYPE)
5314 expr = decay_conversion (expr);
5316 /* If we are in a template, EXPR may be non-dependent, but still
5317 have a syntactic, rather than semantic, form. For example, EXPR
5318 might be a SCOPE_REF, rather than the VAR_DECL to which the
5319 SCOPE_REF refers. Preserving the qualifying scope is necessary
5320 so that access checking can be performed when the template is
5321 instantiated -- but here we need the resolved form so that we can
5322 convert the argument. */
5323 if (TYPE_REF_OBJ_P (type)
5324 && has_value_dependent_address (expr))
5325 /* If we want the address and it's value-dependent, don't fold. */;
5326 else if (!type_unknown_p (expr))
5327 expr = fold_non_dependent_expr_sfinae (expr, complain);
5328 if (error_operand_p (expr))
5329 return error_mark_node;
5330 expr_type = TREE_TYPE (expr);
5331 if (TREE_CODE (type) == REFERENCE_TYPE)
5332 expr = mark_lvalue_use (expr);
5334 expr = mark_rvalue_use (expr);
5336 /* HACK: Due to double coercion, we can get a
5337 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5338 which is the tree that we built on the first call (see
5339 below when coercing to reference to object or to reference to
5340 function). We just strip everything and get to the arg.
5341 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5343 if (TREE_CODE (expr) == NOP_EXPR)
5345 if (TYPE_REF_OBJ_P (type) || TYPE_REFFN_P (type))
5347 /* ??? Maybe we could use convert_from_reference here, but we
5348 would need to relax its constraints because the NOP_EXPR
5349 could actually change the type to something more cv-qualified,
5350 and this is not folded by convert_from_reference. */
5351 tree addr = TREE_OPERAND (expr, 0);
5352 gcc_assert (TREE_CODE (expr_type) == REFERENCE_TYPE);
5353 gcc_assert (TREE_CODE (addr) == ADDR_EXPR);
5354 gcc_assert (TREE_CODE (TREE_TYPE (addr)) == POINTER_TYPE);
5355 gcc_assert (same_type_ignoring_top_level_qualifiers_p
5356 (TREE_TYPE (expr_type),
5357 TREE_TYPE (TREE_TYPE (addr))));
5359 expr = TREE_OPERAND (addr, 0);
5360 expr_type = TREE_TYPE (expr);
5363 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5364 parameter is a pointer to object, through decay and
5365 qualification conversion. Let's strip everything. */
5366 else if (TYPE_PTROBV_P (type))
5369 gcc_assert (TREE_CODE (expr) == ADDR_EXPR);
5370 gcc_assert (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE);
5371 /* Skip the ADDR_EXPR only if it is part of the decay for
5372 an array. Otherwise, it is part of the original argument
5373 in the source code. */
5374 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == ARRAY_TYPE)
5375 expr = TREE_OPERAND (expr, 0);
5376 expr_type = TREE_TYPE (expr);
5380 /* [temp.arg.nontype]/5, bullet 1
5382 For a non-type template-parameter of integral or enumeration type,
5383 integral promotions (_conv.prom_) and integral conversions
5384 (_conv.integral_) are applied. */
5385 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
5387 tree t = build_integral_nontype_arg_conv (type, expr, complain);
5388 t = maybe_constant_value (t);
5389 if (t != error_mark_node)
5392 if (!same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (expr)))
5393 return error_mark_node;
5395 /* Notice that there are constant expressions like '4 % 0' which
5396 do not fold into integer constants. */
5397 if (TREE_CODE (expr) != INTEGER_CST)
5399 if (complain & tf_error)
5401 int errs = errorcount, warns = warningcount;
5402 expr = cxx_constant_value (expr);
5403 if (errorcount > errs || warningcount > warns)
5404 inform (EXPR_LOC_OR_HERE (expr),
5405 "in template argument for type %qT ", type);
5406 if (expr == error_mark_node)
5408 /* else cxx_constant_value complained but gave us
5409 a real constant, so go ahead. */
5410 gcc_assert (TREE_CODE (expr) == INTEGER_CST);
5416 /* [temp.arg.nontype]/5, bullet 2
5418 For a non-type template-parameter of type pointer to object,
5419 qualification conversions (_conv.qual_) and the array-to-pointer
5420 conversion (_conv.array_) are applied. */
5421 else if (TYPE_PTROBV_P (type))
5423 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5425 A template-argument for a non-type, non-template template-parameter
5426 shall be one of: [...]
5428 -- the name of a non-type template-parameter;
5429 -- the address of an object or function with external linkage, [...]
5430 expressed as "& id-expression" where the & is optional if the name
5431 refers to a function or array, or if the corresponding
5432 template-parameter is a reference.
5434 Here, we do not care about functions, as they are invalid anyway
5435 for a parameter of type pointer-to-object. */
5437 if (DECL_P (expr) && DECL_TEMPLATE_PARM_P (expr))
5438 /* Non-type template parameters are OK. */
5440 else if (TREE_CODE (expr) != ADDR_EXPR
5441 && TREE_CODE (expr_type) != ARRAY_TYPE)
5443 if (TREE_CODE (expr) == VAR_DECL)
5445 error ("%qD is not a valid template argument "
5446 "because %qD is a variable, not the address of "
5451 /* Other values, like integer constants, might be valid
5452 non-type arguments of some other type. */
5453 return error_mark_node;
5459 decl = ((TREE_CODE (expr) == ADDR_EXPR)
5460 ? TREE_OPERAND (expr, 0) : expr);
5461 if (TREE_CODE (decl) != VAR_DECL)
5463 error ("%qE is not a valid template argument of type %qT "
5464 "because %qE is not a variable",
5468 else if (!DECL_EXTERNAL_LINKAGE_P (decl))
5470 error ("%qE is not a valid template argument of type %qT "
5471 "because %qD does not have external linkage",
5477 expr = decay_conversion (expr);
5478 if (expr == error_mark_node)
5479 return error_mark_node;
5481 expr = perform_qualification_conversions (type, expr);
5482 if (expr == error_mark_node)
5483 return error_mark_node;
5485 /* [temp.arg.nontype]/5, bullet 3
5487 For a non-type template-parameter of type reference to object, no
5488 conversions apply. The type referred to by the reference may be more
5489 cv-qualified than the (otherwise identical) type of the
5490 template-argument. The template-parameter is bound directly to the
5491 template-argument, which must be an lvalue. */
5492 else if (TYPE_REF_OBJ_P (type))
5494 if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type),
5496 return error_mark_node;
5498 if (!at_least_as_qualified_p (TREE_TYPE (type), expr_type))
5500 error ("%qE is not a valid template argument for type %qT "
5501 "because of conflicts in cv-qualification", expr, type);
5505 if (!real_lvalue_p (expr))
5507 error ("%qE is not a valid template argument for type %qT "
5508 "because it is not an lvalue", expr, type);
5512 /* [temp.arg.nontype]/1
5514 A template-argument for a non-type, non-template template-parameter
5515 shall be one of: [...]
5517 -- the address of an object or function with external linkage. */
5518 if (TREE_CODE (expr) == INDIRECT_REF
5519 && TYPE_REF_OBJ_P (TREE_TYPE (TREE_OPERAND (expr, 0))))
5521 expr = TREE_OPERAND (expr, 0);
5524 error ("%q#D is not a valid template argument for type %qT "
5525 "because a reference variable does not have a constant "
5526 "address", expr, type);
5533 error ("%qE is not a valid template argument for type %qT "
5534 "because it is not an object with external linkage",
5539 if (!DECL_EXTERNAL_LINKAGE_P (expr))
5541 error ("%qE is not a valid template argument for type %qT "
5542 "because object %qD has not external linkage",
5547 expr = build_nop (type, build_address (expr));
5549 /* [temp.arg.nontype]/5, bullet 4
5551 For a non-type template-parameter of type pointer to function, only
5552 the function-to-pointer conversion (_conv.func_) is applied. If the
5553 template-argument represents a set of overloaded functions (or a
5554 pointer to such), the matching function is selected from the set
5556 else if (TYPE_PTRFN_P (type))
5558 /* If the argument is a template-id, we might not have enough
5559 context information to decay the pointer. */
5560 if (!type_unknown_p (expr_type))
5562 expr = decay_conversion (expr);
5563 if (expr == error_mark_node)
5564 return error_mark_node;
5567 expr = convert_nontype_argument_function (type, expr);
5568 if (!expr || expr == error_mark_node)
5571 if (TREE_CODE (expr) != ADDR_EXPR)
5573 error ("%qE is not a valid template argument for type %qT", expr, type);
5574 error ("it must be the address of a function with external linkage");
5578 /* [temp.arg.nontype]/5, bullet 5
5580 For a non-type template-parameter of type reference to function, no
5581 conversions apply. If the template-argument represents a set of
5582 overloaded functions, the matching function is selected from the set
5584 else if (TYPE_REFFN_P (type))
5586 if (TREE_CODE (expr) == ADDR_EXPR)
5588 error ("%qE is not a valid template argument for type %qT "
5589 "because it is a pointer", expr, type);
5590 inform (input_location, "try using %qE instead", TREE_OPERAND (expr, 0));
5594 expr = convert_nontype_argument_function (TREE_TYPE (type), expr);
5595 if (!expr || expr == error_mark_node)
5598 expr = build_nop (type, build_address (expr));
5600 /* [temp.arg.nontype]/5, bullet 6
5602 For a non-type template-parameter of type pointer to member function,
5603 no conversions apply. If the template-argument represents a set of
5604 overloaded member functions, the matching member function is selected
5605 from the set (_over.over_). */
5606 else if (TYPE_PTRMEMFUNC_P (type))
5608 expr = instantiate_type (type, expr, tf_none);
5609 if (expr == error_mark_node)
5610 return error_mark_node;
5612 /* [temp.arg.nontype] bullet 1 says the pointer to member
5613 expression must be a pointer-to-member constant. */
5614 if (!check_valid_ptrmem_cst_expr (type, expr, complain))
5615 return error_mark_node;
5617 /* There is no way to disable standard conversions in
5618 resolve_address_of_overloaded_function (called by
5619 instantiate_type). It is possible that the call succeeded by
5620 converting &B::I to &D::I (where B is a base of D), so we need
5621 to reject this conversion here.
5623 Actually, even if there was a way to disable standard conversions,
5624 it would still be better to reject them here so that we can
5625 provide a superior diagnostic. */
5626 if (!same_type_p (TREE_TYPE (expr), type))
5628 error ("%qE is not a valid template argument for type %qT "
5629 "because it is of type %qT", expr, type,
5631 /* If we are just one standard conversion off, explain. */
5632 if (can_convert (type, TREE_TYPE (expr)))
5633 inform (input_location,
5634 "standard conversions are not allowed in this context");
5638 /* [temp.arg.nontype]/5, bullet 7
5640 For a non-type template-parameter of type pointer to data member,
5641 qualification conversions (_conv.qual_) are applied. */
5642 else if (TYPE_PTRMEM_P (type))
5644 /* [temp.arg.nontype] bullet 1 says the pointer to member
5645 expression must be a pointer-to-member constant. */
5646 if (!check_valid_ptrmem_cst_expr (type, expr, complain))
5647 return error_mark_node;
5649 expr = perform_qualification_conversions (type, expr);
5650 if (expr == error_mark_node)
5653 /* A template non-type parameter must be one of the above. */
5657 /* Sanity check: did we actually convert the argument to the
5659 gcc_assert (same_type_ignoring_top_level_qualifiers_p
5660 (type, TREE_TYPE (expr)));
5664 /* Subroutine of coerce_template_template_parms, which returns 1 if
5665 PARM_PARM and ARG_PARM match using the rule for the template
5666 parameters of template template parameters. Both PARM and ARG are
5667 template parameters; the rest of the arguments are the same as for
5668 coerce_template_template_parms.
5671 coerce_template_template_parm (tree parm,
5673 tsubst_flags_t complain,
5677 if (arg == NULL_TREE || arg == error_mark_node
5678 || parm == NULL_TREE || parm == error_mark_node)
5681 if (TREE_CODE (arg) != TREE_CODE (parm))
5684 switch (TREE_CODE (parm))
5687 /* We encounter instantiations of templates like
5688 template <template <template <class> class> class TT>
5691 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
5692 tree argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
5694 if (!coerce_template_template_parms
5695 (parmparm, argparm, complain, in_decl, outer_args))
5701 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (arg))
5702 && !TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
5703 /* Argument is a parameter pack but parameter is not. */
5708 /* The tsubst call is used to handle cases such as
5710 template <int> class C {};
5711 template <class T, template <T> class TT> class D {};
5714 i.e. the parameter list of TT depends on earlier parameters. */
5715 if (!uses_template_parms (TREE_TYPE (arg))
5717 (tsubst (TREE_TYPE (parm), outer_args, complain, in_decl),
5721 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (arg))
5722 && !TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
5723 /* Argument is a parameter pack but parameter is not. */
5736 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
5737 template template parameters. Both PARM_PARMS and ARG_PARMS are
5738 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
5741 Consider the example:
5742 template <class T> class A;
5743 template<template <class U> class TT> class B;
5745 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
5746 the parameters to A, and OUTER_ARGS contains A. */
5749 coerce_template_template_parms (tree parm_parms,
5751 tsubst_flags_t complain,
5755 int nparms, nargs, i;
5759 gcc_assert (TREE_CODE (parm_parms) == TREE_VEC);
5760 gcc_assert (TREE_CODE (arg_parms) == TREE_VEC);
5762 nparms = TREE_VEC_LENGTH (parm_parms);
5763 nargs = TREE_VEC_LENGTH (arg_parms);
5765 /* Determine whether we have a parameter pack at the end of the
5766 template template parameter's template parameter list. */
5767 if (TREE_VEC_ELT (parm_parms, nparms - 1) != error_mark_node)
5769 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, nparms - 1));
5771 if (parm == error_mark_node)
5774 switch (TREE_CODE (parm))
5778 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
5783 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
5793 && !(variadic_p && nargs >= nparms - 1))
5796 /* Check all of the template parameters except the parameter pack at
5797 the end (if any). */
5798 for (i = 0; i < nparms - variadic_p; ++i)
5800 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node
5801 || TREE_VEC_ELT (arg_parms, i) == error_mark_node)
5804 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
5805 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
5807 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
5815 /* Check each of the template parameters in the template
5816 argument against the template parameter pack at the end of
5817 the template template parameter. */
5818 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node)
5821 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
5823 for (; i < nargs; ++i)
5825 if (TREE_VEC_ELT (arg_parms, i) == error_mark_node)
5828 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
5830 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
5839 /* Verifies that the deduced template arguments (in TARGS) for the
5840 template template parameters (in TPARMS) represent valid bindings,
5841 by comparing the template parameter list of each template argument
5842 to the template parameter list of its corresponding template
5843 template parameter, in accordance with DR150. This
5844 routine can only be called after all template arguments have been
5845 deduced. It will return TRUE if all of the template template
5846 parameter bindings are okay, FALSE otherwise. */
5848 template_template_parm_bindings_ok_p (tree tparms, tree targs)
5850 int i, ntparms = TREE_VEC_LENGTH (tparms);
5853 /* We're dealing with template parms in this process. */
5854 ++processing_template_decl;
5856 targs = INNERMOST_TEMPLATE_ARGS (targs);
5858 for (i = 0; i < ntparms; ++i)
5860 tree tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
5861 tree targ = TREE_VEC_ELT (targs, i);
5863 if (TREE_CODE (tparm) == TEMPLATE_DECL && targ)
5865 tree packed_args = NULL_TREE;
5868 if (ARGUMENT_PACK_P (targ))
5870 /* Look inside the argument pack. */
5871 packed_args = ARGUMENT_PACK_ARGS (targ);
5872 len = TREE_VEC_LENGTH (packed_args);
5875 for (idx = 0; idx < len; ++idx)
5877 tree targ_parms = NULL_TREE;
5880 /* Extract the next argument from the argument
5882 targ = TREE_VEC_ELT (packed_args, idx);
5884 if (PACK_EXPANSION_P (targ))
5885 /* Look at the pattern of the pack expansion. */
5886 targ = PACK_EXPANSION_PATTERN (targ);
5888 /* Extract the template parameters from the template
5890 if (TREE_CODE (targ) == TEMPLATE_DECL)
5891 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (targ);
5892 else if (TREE_CODE (targ) == TEMPLATE_TEMPLATE_PARM)
5893 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (TYPE_NAME (targ));
5895 /* Verify that we can coerce the template template
5896 parameters from the template argument to the template
5897 parameter. This requires an exact match. */
5899 && !coerce_template_template_parms
5900 (DECL_INNERMOST_TEMPLATE_PARMS (tparm),
5915 --processing_template_decl;
5919 /* Since type attributes aren't mangled, we need to strip them from
5920 template type arguments. */
5923 canonicalize_type_argument (tree arg, tsubst_flags_t complain)
5926 if (!arg || arg == error_mark_node || arg == TYPE_CANONICAL (arg))
5928 mv = TYPE_MAIN_VARIANT (arg);
5929 arg = strip_typedefs (arg);
5930 if (TYPE_ALIGN (arg) != TYPE_ALIGN (mv)
5931 || TYPE_ATTRIBUTES (arg) != TYPE_ATTRIBUTES (mv))
5933 if (complain & tf_warning)
5934 warning (0, "ignoring attributes on template argument %qT", arg);
5935 arg = build_aligned_type (arg, TYPE_ALIGN (mv));
5936 arg = cp_build_type_attribute_variant (arg, TYPE_ATTRIBUTES (mv));
5941 /* Convert the indicated template ARG as necessary to match the
5942 indicated template PARM. Returns the converted ARG, or
5943 error_mark_node if the conversion was unsuccessful. Error and
5944 warning messages are issued under control of COMPLAIN. This
5945 conversion is for the Ith parameter in the parameter list. ARGS is
5946 the full set of template arguments deduced so far. */
5949 convert_template_argument (tree parm,
5952 tsubst_flags_t complain,
5958 int is_type, requires_type, is_tmpl_type, requires_tmpl_type;
5960 if (TREE_CODE (arg) == TREE_LIST
5961 && TREE_CODE (TREE_VALUE (arg)) == OFFSET_REF)
5963 /* The template argument was the name of some
5964 member function. That's usually
5965 invalid, but static members are OK. In any
5966 case, grab the underlying fields/functions
5967 and issue an error later if required. */
5968 orig_arg = TREE_VALUE (arg);
5969 TREE_TYPE (arg) = unknown_type_node;
5974 requires_tmpl_type = TREE_CODE (parm) == TEMPLATE_DECL;
5975 requires_type = (TREE_CODE (parm) == TYPE_DECL
5976 || requires_tmpl_type);
5978 /* When determining whether an argument pack expansion is a template,
5979 look at the pattern. */
5980 if (TREE_CODE (arg) == TYPE_PACK_EXPANSION)
5981 arg = PACK_EXPANSION_PATTERN (arg);
5983 /* Deal with an injected-class-name used as a template template arg. */
5984 if (requires_tmpl_type && CLASS_TYPE_P (arg))
5986 tree t = maybe_get_template_decl_from_type_decl (TYPE_NAME (arg));
5987 if (TREE_CODE (t) == TEMPLATE_DECL)
5989 if (cxx_dialect >= cxx0x)
5990 /* OK under DR 1004. */;
5991 else if (complain & tf_warning_or_error)
5992 pedwarn (input_location, OPT_pedantic, "injected-class-name %qD"
5993 " used as template template argument", TYPE_NAME (arg));
5994 else if (flag_pedantic_errors)
6002 ((TREE_CODE (arg) == TEMPLATE_DECL
6003 && TREE_CODE (DECL_TEMPLATE_RESULT (arg)) == TYPE_DECL)
6004 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
6005 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE);
6008 && (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
6009 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE))
6010 arg = TYPE_STUB_DECL (arg);
6012 is_type = TYPE_P (arg) || is_tmpl_type;
6014 if (requires_type && ! is_type && TREE_CODE (arg) == SCOPE_REF
6015 && TREE_CODE (TREE_OPERAND (arg, 0)) == TEMPLATE_TYPE_PARM)
6017 permerror (input_location, "to refer to a type member of a template parameter, "
6018 "use %<typename %E%>", orig_arg);
6020 orig_arg = make_typename_type (TREE_OPERAND (arg, 0),
6021 TREE_OPERAND (arg, 1),
6023 complain & tf_error);
6027 if (is_type != requires_type)
6031 if (complain & tf_error)
6033 error ("type/value mismatch at argument %d in template "
6034 "parameter list for %qD",
6037 error (" expected a constant of type %qT, got %qT",
6039 (DECL_P (arg) ? DECL_NAME (arg) : orig_arg));
6040 else if (requires_tmpl_type)
6041 error (" expected a class template, got %qE", orig_arg);
6043 error (" expected a type, got %qE", orig_arg);
6046 return error_mark_node;
6048 if (is_tmpl_type ^ requires_tmpl_type)
6050 if (in_decl && (complain & tf_error))
6052 error ("type/value mismatch at argument %d in template "
6053 "parameter list for %qD",
6056 error (" expected a type, got %qT", DECL_NAME (arg));
6058 error (" expected a class template, got %qT", orig_arg);
6060 return error_mark_node;
6065 if (requires_tmpl_type)
6067 if (TREE_CODE (TREE_TYPE (arg)) == UNBOUND_CLASS_TEMPLATE)
6068 /* The number of argument required is not known yet.
6069 Just accept it for now. */
6070 val = TREE_TYPE (arg);
6073 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
6076 argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
6078 if (coerce_template_template_parms (parmparm, argparm,
6084 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6086 if (val != error_mark_node)
6088 if (DECL_TEMPLATE_TEMPLATE_PARM_P (val))
6089 val = TREE_TYPE (val);
6090 if (TREE_CODE (orig_arg) == TYPE_PACK_EXPANSION)
6091 val = make_pack_expansion (val);
6096 if (in_decl && (complain & tf_error))
6098 error ("type/value mismatch at argument %d in "
6099 "template parameter list for %qD",
6101 error (" expected a template of type %qD, got %qT",
6105 val = error_mark_node;
6111 /* We only form one instance of each template specialization.
6112 Therefore, if we use a non-canonical variant (i.e., a
6113 typedef), any future messages referring to the type will use
6114 the typedef, which is confusing if those future uses do not
6115 themselves also use the typedef. */
6117 val = canonicalize_type_argument (val, complain);
6121 tree t = tsubst (TREE_TYPE (parm), args, complain, in_decl);
6123 if (invalid_nontype_parm_type_p (t, complain))
6124 return error_mark_node;
6126 if (template_parameter_pack_p (parm) && ARGUMENT_PACK_P (orig_arg))
6128 if (same_type_p (t, TREE_TYPE (orig_arg)))
6132 /* Not sure if this is reachable, but it doesn't hurt
6134 error ("type mismatch in nontype parameter pack");
6135 val = error_mark_node;
6138 else if (!uses_template_parms (orig_arg) && !uses_template_parms (t))
6139 /* We used to call digest_init here. However, digest_init
6140 will report errors, which we don't want when complain
6141 is zero. More importantly, digest_init will try too
6142 hard to convert things: for example, `0' should not be
6143 converted to pointer type at this point according to
6144 the standard. Accepting this is not merely an
6145 extension, since deciding whether or not these
6146 conversions can occur is part of determining which
6147 function template to call, or whether a given explicit
6148 argument specification is valid. */
6149 val = convert_nontype_argument (t, orig_arg, complain);
6153 if (val == NULL_TREE)
6154 val = error_mark_node;
6155 else if (val == error_mark_node && (complain & tf_error))
6156 error ("could not convert template argument %qE to %qT", orig_arg, t);
6158 if (TREE_CODE (val) == SCOPE_REF)
6160 /* Strip typedefs from the SCOPE_REF. */
6161 tree type = canonicalize_type_argument (TREE_TYPE (val), complain);
6162 tree scope = canonicalize_type_argument (TREE_OPERAND (val, 0),
6164 val = build_qualified_name (type, scope, TREE_OPERAND (val, 1),
6165 QUALIFIED_NAME_IS_TEMPLATE (val));
6172 /* Coerces the remaining template arguments in INNER_ARGS (from
6173 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6174 Returns the coerced argument pack. PARM_IDX is the position of this
6175 parameter in the template parameter list. ARGS is the original
6176 template argument list. */
6178 coerce_template_parameter_pack (tree parms,
6186 tsubst_flags_t complain)
6188 tree parm = TREE_VEC_ELT (parms, parm_idx);
6189 int nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
6192 tree packed_types = NULL_TREE;
6194 if (arg_idx > nargs)
6197 packed_args = make_tree_vec (nargs - arg_idx);
6199 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL
6200 && uses_parameter_packs (TREE_TYPE (TREE_VALUE (parm))))
6202 /* When the template parameter is a non-type template
6203 parameter pack whose type uses parameter packs, we need
6204 to look at each of the template arguments
6205 separately. Build a vector of the types for these
6206 non-type template parameters in PACKED_TYPES. */
6208 = make_pack_expansion (TREE_TYPE (TREE_VALUE (parm)));
6209 packed_types = tsubst_pack_expansion (expansion, args,
6212 if (packed_types == error_mark_node)
6213 return error_mark_node;
6215 /* Check that we have the right number of arguments. */
6217 && !PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx))
6218 && nargs - arg_idx != TREE_VEC_LENGTH (packed_types))
6221 = TREE_VEC_LENGTH (parms) - 1 + TREE_VEC_LENGTH (packed_types);
6222 error ("wrong number of template arguments (%d, should be %d)",
6223 nargs, needed_parms);
6224 return error_mark_node;
6227 /* If we aren't able to check the actual arguments now
6228 (because they haven't been expanded yet), we can at least
6229 verify that all of the types used for the non-type
6230 template parameter pack are, in fact, valid for non-type
6231 template parameters. */
6233 && PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx)))
6235 int j, len = TREE_VEC_LENGTH (packed_types);
6236 for (j = 0; j < len; ++j)
6238 tree t = TREE_VEC_ELT (packed_types, j);
6239 if (invalid_nontype_parm_type_p (t, complain))
6240 return error_mark_node;
6245 /* Convert the remaining arguments, which will be a part of the
6246 parameter pack "parm". */
6247 for (; arg_idx < nargs; ++arg_idx)
6249 tree arg = TREE_VEC_ELT (inner_args, arg_idx);
6250 tree actual_parm = TREE_VALUE (parm);
6252 if (packed_types && !PACK_EXPANSION_P (arg))
6254 /* When we have a vector of types (corresponding to the
6255 non-type template parameter pack that uses parameter
6256 packs in its type, as mention above), and the
6257 argument is not an expansion (which expands to a
6258 currently unknown number of arguments), clone the
6259 parm and give it the next type in PACKED_TYPES. */
6260 actual_parm = copy_node (actual_parm);
6261 TREE_TYPE (actual_parm) =
6262 TREE_VEC_ELT (packed_types, arg_idx - parm_idx);
6265 if (arg != error_mark_node)
6266 arg = convert_template_argument (actual_parm,
6267 arg, new_args, complain, parm_idx,
6269 if (arg == error_mark_node)
6271 TREE_VEC_ELT (packed_args, arg_idx - parm_idx) = arg;
6274 if (TREE_CODE (TREE_VALUE (parm)) == TYPE_DECL
6275 || TREE_CODE (TREE_VALUE (parm)) == TEMPLATE_DECL)
6276 argument_pack = cxx_make_type (TYPE_ARGUMENT_PACK);
6279 argument_pack = make_node (NONTYPE_ARGUMENT_PACK);
6280 TREE_TYPE (argument_pack)
6281 = tsubst (TREE_TYPE (TREE_VALUE (parm)), new_args, complain, in_decl);
6282 TREE_CONSTANT (argument_pack) = 1;
6285 SET_ARGUMENT_PACK_ARGS (argument_pack, packed_args);
6286 #ifdef ENABLE_CHECKING
6287 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (packed_args,
6288 TREE_VEC_LENGTH (packed_args));
6290 return argument_pack;
6293 /* Convert all template arguments to their appropriate types, and
6294 return a vector containing the innermost resulting template
6295 arguments. If any error occurs, return error_mark_node. Error and
6296 warning messages are issued under control of COMPLAIN.
6298 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6299 for arguments not specified in ARGS. Otherwise, if
6300 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6301 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6302 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6306 coerce_template_parms (tree parms,
6309 tsubst_flags_t complain,
6310 bool require_all_args,
6311 bool use_default_args)
6313 int nparms, nargs, parm_idx, arg_idx, lost = 0;
6316 tree new_inner_args;
6317 int saved_unevaluated_operand;
6318 int saved_inhibit_evaluation_warnings;
6320 /* When used as a boolean value, indicates whether this is a
6321 variadic template parameter list. Since it's an int, we can also
6322 subtract it from nparms to get the number of non-variadic
6326 if (args == error_mark_node)
6327 return error_mark_node;
6329 nparms = TREE_VEC_LENGTH (parms);
6331 /* Determine if there are any parameter packs. */
6332 for (parm_idx = 0; parm_idx < nparms; ++parm_idx)
6334 tree tparm = TREE_VALUE (TREE_VEC_ELT (parms, parm_idx));
6335 if (template_parameter_pack_p (tparm))
6339 inner_args = INNERMOST_TEMPLATE_ARGS (args);
6340 /* If there are 0 or 1 parameter packs, we need to expand any argument
6341 packs so that we can deduce a parameter pack from some non-packed args
6342 followed by an argument pack, as in variadic85.C. If there are more
6343 than that, we need to leave argument packs intact so the arguments are
6344 assigned to the right parameter packs. This should only happen when
6345 dealing with a nested class inside a partial specialization of a class
6346 template, as in variadic92.C. */
6347 if (variadic_p <= 1)
6348 inner_args = expand_template_argument_pack (inner_args);
6350 nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
6351 if ((nargs > nparms && !variadic_p)
6352 || (nargs < nparms - variadic_p
6354 && (!use_default_args
6355 || (TREE_VEC_ELT (parms, nargs) != error_mark_node
6356 && !TREE_PURPOSE (TREE_VEC_ELT (parms, nargs))))))
6358 if (complain & tf_error)
6363 error ("wrong number of template arguments "
6364 "(%d, should be %d or more)", nargs, nparms);
6367 error ("wrong number of template arguments "
6368 "(%d, should be %d)", nargs, nparms);
6371 error ("provided for %q+D", in_decl);
6374 return error_mark_node;
6377 /* We need to evaluate the template arguments, even though this
6378 template-id may be nested within a "sizeof". */
6379 saved_unevaluated_operand = cp_unevaluated_operand;
6380 cp_unevaluated_operand = 0;
6381 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
6382 c_inhibit_evaluation_warnings = 0;
6383 new_inner_args = make_tree_vec (nparms);
6384 new_args = add_outermost_template_args (args, new_inner_args);
6385 for (parm_idx = 0, arg_idx = 0; parm_idx < nparms; parm_idx++, arg_idx++)
6390 /* Get the Ith template parameter. */
6391 parm = TREE_VEC_ELT (parms, parm_idx);
6393 if (parm == error_mark_node)
6395 TREE_VEC_ELT (new_inner_args, arg_idx) = error_mark_node;
6399 /* Calculate the next argument. */
6400 if (arg_idx < nargs)
6401 arg = TREE_VEC_ELT (inner_args, arg_idx);
6405 if (template_parameter_pack_p (TREE_VALUE (parm))
6406 && !(arg && ARGUMENT_PACK_P (arg)))
6408 /* All remaining arguments will be placed in the
6409 template parameter pack PARM. */
6410 arg = coerce_template_parameter_pack (parms, parm_idx, args,
6411 inner_args, arg_idx,
6415 /* Store this argument. */
6416 if (arg == error_mark_node)
6418 TREE_VEC_ELT (new_inner_args, parm_idx) = arg;
6420 /* We are done with all of the arguments. */
6427 if (PACK_EXPANSION_P (arg))
6429 if (complain & tf_error)
6431 /* FIXME this restriction was removed by N2555; see
6433 /* If ARG is a pack expansion, but PARM is not a
6434 template parameter pack (if it were, we would have
6435 handled it above), we're trying to expand into a
6436 fixed-length argument list. */
6437 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
6438 sorry ("cannot expand %<%E%> into a fixed-length "
6439 "argument list", arg);
6441 sorry ("cannot expand %<%T%> into a fixed-length "
6442 "argument list", arg);
6447 else if (require_all_args)
6449 /* There must be a default arg in this case. */
6450 arg = tsubst_template_arg (TREE_PURPOSE (parm), new_args,
6452 /* The position of the first default template argument,
6453 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6455 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args))
6456 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args, arg_idx);
6461 if (arg == error_mark_node)
6463 if (complain & tf_error)
6464 error ("template argument %d is invalid", arg_idx + 1);
6467 /* This only occurs if there was an error in the template
6468 parameter list itself (which we would already have
6469 reported) that we are trying to recover from, e.g., a class
6470 template with a parameter list such as
6471 template<typename..., typename>. */
6474 arg = convert_template_argument (TREE_VALUE (parm),
6475 arg, new_args, complain,
6478 if (arg == error_mark_node)
6480 TREE_VEC_ELT (new_inner_args, arg_idx) = arg;
6482 cp_unevaluated_operand = saved_unevaluated_operand;
6483 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
6486 return error_mark_node;
6488 #ifdef ENABLE_CHECKING
6489 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args))
6490 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args,
6491 TREE_VEC_LENGTH (new_inner_args));
6494 return new_inner_args;
6497 /* Returns 1 if template args OT and NT are equivalent. */
6500 template_args_equal (tree ot, tree nt)
6504 if (nt == NULL_TREE || ot == NULL_TREE)
6507 if (TREE_CODE (nt) == TREE_VEC)
6508 /* For member templates */
6509 return TREE_CODE (ot) == TREE_VEC && comp_template_args (ot, nt);
6510 else if (PACK_EXPANSION_P (ot))
6511 return PACK_EXPANSION_P (nt)
6512 && template_args_equal (PACK_EXPANSION_PATTERN (ot),
6513 PACK_EXPANSION_PATTERN (nt));
6514 else if (ARGUMENT_PACK_P (ot))
6519 if (!ARGUMENT_PACK_P (nt))
6522 opack = ARGUMENT_PACK_ARGS (ot);
6523 npack = ARGUMENT_PACK_ARGS (nt);
6524 len = TREE_VEC_LENGTH (opack);
6525 if (TREE_VEC_LENGTH (npack) != len)
6527 for (i = 0; i < len; ++i)
6528 if (!template_args_equal (TREE_VEC_ELT (opack, i),
6529 TREE_VEC_ELT (npack, i)))
6533 else if (ot && TREE_CODE (ot) == ARGUMENT_PACK_SELECT)
6535 /* We get here probably because we are in the middle of substituting
6536 into the pattern of a pack expansion. In that case the
6537 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
6538 interested in. So we want to use the initial pack argument for
6540 ot = ARGUMENT_PACK_SELECT_FROM_PACK (ot);
6541 if (nt && TREE_CODE (nt) == ARGUMENT_PACK_SELECT)
6542 nt = ARGUMENT_PACK_SELECT_FROM_PACK (nt);
6543 return template_args_equal (ot, nt);
6545 else if (TYPE_P (nt))
6546 return TYPE_P (ot) && same_type_p (ot, nt);
6547 else if (TREE_CODE (ot) == TREE_VEC || TYPE_P (ot))
6550 return cp_tree_equal (ot, nt);
6553 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
6554 of template arguments. Returns 0 otherwise. */
6557 comp_template_args (tree oldargs, tree newargs)
6561 if (TREE_VEC_LENGTH (oldargs) != TREE_VEC_LENGTH (newargs))
6564 for (i = 0; i < TREE_VEC_LENGTH (oldargs); ++i)
6566 tree nt = TREE_VEC_ELT (newargs, i);
6567 tree ot = TREE_VEC_ELT (oldargs, i);
6569 if (! template_args_equal (ot, nt))
6576 add_pending_template (tree d)
6578 tree ti = (TYPE_P (d)
6579 ? CLASSTYPE_TEMPLATE_INFO (d)
6580 : DECL_TEMPLATE_INFO (d));
6581 struct pending_template *pt;
6584 if (TI_PENDING_TEMPLATE_FLAG (ti))
6587 /* We are called both from instantiate_decl, where we've already had a
6588 tinst_level pushed, and instantiate_template, where we haven't.
6590 level = !current_tinst_level || current_tinst_level->decl != d;
6593 push_tinst_level (d);
6595 pt = ggc_alloc_pending_template ();
6597 pt->tinst = current_tinst_level;
6598 if (last_pending_template)
6599 last_pending_template->next = pt;
6601 pending_templates = pt;
6603 last_pending_template = pt;
6605 TI_PENDING_TEMPLATE_FLAG (ti) = 1;
6612 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
6613 ARGLIST. Valid choices for FNS are given in the cp-tree.def
6614 documentation for TEMPLATE_ID_EXPR. */
6617 lookup_template_function (tree fns, tree arglist)
6621 if (fns == error_mark_node || arglist == error_mark_node)
6622 return error_mark_node;
6624 gcc_assert (!arglist || TREE_CODE (arglist) == TREE_VEC);
6626 if (!is_overloaded_fn (fns) && TREE_CODE (fns) != IDENTIFIER_NODE)
6628 error ("%q#D is not a function template", fns);
6629 return error_mark_node;
6632 if (BASELINK_P (fns))
6634 BASELINK_FUNCTIONS (fns) = build2 (TEMPLATE_ID_EXPR,
6636 BASELINK_FUNCTIONS (fns),
6641 type = TREE_TYPE (fns);
6642 if (TREE_CODE (fns) == OVERLOAD || !type)
6643 type = unknown_type_node;
6645 return build2 (TEMPLATE_ID_EXPR, type, fns, arglist);
6648 /* Within the scope of a template class S<T>, the name S gets bound
6649 (in build_self_reference) to a TYPE_DECL for the class, not a
6650 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
6651 or one of its enclosing classes, and that type is a template,
6652 return the associated TEMPLATE_DECL. Otherwise, the original
6655 Also handle the case when DECL is a TREE_LIST of ambiguous
6656 injected-class-names from different bases. */
6659 maybe_get_template_decl_from_type_decl (tree decl)
6661 if (decl == NULL_TREE)
6664 /* DR 176: A lookup that finds an injected-class-name (10.2
6665 [class.member.lookup]) can result in an ambiguity in certain cases
6666 (for example, if it is found in more than one base class). If all of
6667 the injected-class-names that are found refer to specializations of
6668 the same class template, and if the name is followed by a
6669 template-argument-list, the reference refers to the class template
6670 itself and not a specialization thereof, and is not ambiguous. */
6671 if (TREE_CODE (decl) == TREE_LIST)
6673 tree t, tmpl = NULL_TREE;
6674 for (t = decl; t; t = TREE_CHAIN (t))
6676 tree elt = maybe_get_template_decl_from_type_decl (TREE_VALUE (t));
6679 else if (tmpl != elt)
6682 if (tmpl && t == NULL_TREE)
6688 return (decl != NULL_TREE
6689 && DECL_SELF_REFERENCE_P (decl)
6690 && CLASSTYPE_TEMPLATE_INFO (TREE_TYPE (decl)))
6691 ? CLASSTYPE_TI_TEMPLATE (TREE_TYPE (decl)) : decl;
6694 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
6695 parameters, find the desired type.
6697 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
6699 IN_DECL, if non-NULL, is the template declaration we are trying to
6702 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
6703 the class we are looking up.
6705 Issue error and warning messages under control of COMPLAIN.
6707 If the template class is really a local class in a template
6708 function, then the FUNCTION_CONTEXT is the function in which it is
6711 ??? Note that this function is currently called *twice* for each
6712 template-id: the first time from the parser, while creating the
6713 incomplete type (finish_template_type), and the second type during the
6714 real instantiation (instantiate_template_class). This is surely something
6715 that we want to avoid. It also causes some problems with argument
6716 coercion (see convert_nontype_argument for more information on this). */
6719 lookup_template_class_1 (tree d1, tree arglist, tree in_decl, tree context,
6720 int entering_scope, tsubst_flags_t complain)
6722 tree templ = NULL_TREE, parmlist;
6729 if (TREE_CODE (d1) == IDENTIFIER_NODE)
6731 tree value = innermost_non_namespace_value (d1);
6732 if (value && DECL_TEMPLATE_TEMPLATE_PARM_P (value))
6737 push_decl_namespace (context);
6738 templ = lookup_name (d1);
6739 templ = maybe_get_template_decl_from_type_decl (templ);
6741 pop_decl_namespace ();
6744 context = DECL_CONTEXT (templ);
6746 else if (TREE_CODE (d1) == TYPE_DECL && MAYBE_CLASS_TYPE_P (TREE_TYPE (d1)))
6748 tree type = TREE_TYPE (d1);
6750 /* If we are declaring a constructor, say A<T>::A<T>, we will get
6751 an implicit typename for the second A. Deal with it. */
6752 if (TREE_CODE (type) == TYPENAME_TYPE && TREE_TYPE (type))
6753 type = TREE_TYPE (type);
6755 if (CLASSTYPE_TEMPLATE_INFO (type))
6757 templ = CLASSTYPE_TI_TEMPLATE (type);
6758 d1 = DECL_NAME (templ);
6761 else if (TREE_CODE (d1) == ENUMERAL_TYPE
6762 || (TYPE_P (d1) && MAYBE_CLASS_TYPE_P (d1)))
6764 templ = TYPE_TI_TEMPLATE (d1);
6765 d1 = DECL_NAME (templ);
6767 else if (TREE_CODE (d1) == TEMPLATE_DECL
6768 && DECL_TEMPLATE_RESULT (d1)
6769 && TREE_CODE (DECL_TEMPLATE_RESULT (d1)) == TYPE_DECL)
6772 d1 = DECL_NAME (templ);
6773 context = DECL_CONTEXT (templ);
6776 /* Issue an error message if we didn't find a template. */
6779 if (complain & tf_error)
6780 error ("%qT is not a template", d1);
6781 return error_mark_node;
6784 if (TREE_CODE (templ) != TEMPLATE_DECL
6785 /* Make sure it's a user visible template, if it was named by
6787 || ((complain & tf_user) && !DECL_TEMPLATE_PARM_P (templ)
6788 && !PRIMARY_TEMPLATE_P (templ)))
6790 if (complain & tf_error)
6792 error ("non-template type %qT used as a template", d1);
6794 error ("for template declaration %q+D", in_decl);
6796 return error_mark_node;
6799 complain &= ~tf_user;
6801 if (DECL_TEMPLATE_TEMPLATE_PARM_P (templ))
6803 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
6804 template arguments */
6810 parmlist = DECL_INNERMOST_TEMPLATE_PARMS (templ);
6812 /* Consider an example where a template template parameter declared as
6814 template <class T, class U = std::allocator<T> > class TT
6816 The template parameter level of T and U are one level larger than
6817 of TT. To proper process the default argument of U, say when an
6818 instantiation `TT<int>' is seen, we need to build the full
6819 arguments containing {int} as the innermost level. Outer levels,
6820 available when not appearing as default template argument, can be
6821 obtained from the arguments of the enclosing template.
6823 Suppose that TT is later substituted with std::vector. The above
6824 instantiation is `TT<int, std::allocator<T> >' with TT at
6825 level 1, and T at level 2, while the template arguments at level 1
6826 becomes {std::vector} and the inner level 2 is {int}. */
6828 outer = DECL_CONTEXT (templ);
6830 outer = TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (outer)));
6831 else if (current_template_parms)
6832 /* This is an argument of the current template, so we haven't set
6833 DECL_CONTEXT yet. */
6834 outer = current_template_args ();
6837 arglist = add_to_template_args (outer, arglist);
6839 arglist2 = coerce_template_parms (parmlist, arglist, templ,
6841 /*require_all_args=*/true,
6842 /*use_default_args=*/true);
6843 if (arglist2 == error_mark_node
6844 || (!uses_template_parms (arglist2)
6845 && check_instantiated_args (templ, arglist2, complain)))
6846 return error_mark_node;
6848 parm = bind_template_template_parm (TREE_TYPE (templ), arglist2);
6853 tree template_type = TREE_TYPE (templ);
6856 tree found = NULL_TREE;
6859 int is_dependent_type;
6860 int use_partial_inst_tmpl = false;
6862 gen_tmpl = most_general_template (templ);
6863 parmlist = DECL_TEMPLATE_PARMS (gen_tmpl);
6864 parm_depth = TMPL_PARMS_DEPTH (parmlist);
6865 arg_depth = TMPL_ARGS_DEPTH (arglist);
6867 if (arg_depth == 1 && parm_depth > 1)
6869 /* We've been given an incomplete set of template arguments.
6872 template <class T> struct S1 {
6873 template <class U> struct S2 {};
6874 template <class U> struct S2<U*> {};
6877 we will be called with an ARGLIST of `U*', but the
6878 TEMPLATE will be `template <class T> template
6879 <class U> struct S1<T>::S2'. We must fill in the missing
6882 = add_outermost_template_args (TYPE_TI_ARGS (TREE_TYPE (templ)),
6884 arg_depth = TMPL_ARGS_DEPTH (arglist);
6887 /* Now we should have enough arguments. */
6888 gcc_assert (parm_depth == arg_depth);
6890 /* From here on, we're only interested in the most general
6893 /* Calculate the BOUND_ARGS. These will be the args that are
6894 actually tsubst'd into the definition to create the
6898 /* We have multiple levels of arguments to coerce, at once. */
6900 int saved_depth = TMPL_ARGS_DEPTH (arglist);
6902 tree bound_args = make_tree_vec (parm_depth);
6904 for (i = saved_depth,
6905 t = DECL_TEMPLATE_PARMS (gen_tmpl);
6906 i > 0 && t != NULL_TREE;
6907 --i, t = TREE_CHAIN (t))
6910 if (i == saved_depth)
6911 a = coerce_template_parms (TREE_VALUE (t),
6914 /*require_all_args=*/true,
6915 /*use_default_args=*/true);
6917 /* Outer levels should have already been coerced. */
6918 a = TMPL_ARGS_LEVEL (arglist, i);
6920 /* Don't process further if one of the levels fails. */
6921 if (a == error_mark_node)
6923 /* Restore the ARGLIST to its full size. */
6924 TREE_VEC_LENGTH (arglist) = saved_depth;
6925 return error_mark_node;
6928 SET_TMPL_ARGS_LEVEL (bound_args, i, a);
6930 /* We temporarily reduce the length of the ARGLIST so
6931 that coerce_template_parms will see only the arguments
6932 corresponding to the template parameters it is
6934 TREE_VEC_LENGTH (arglist)--;
6937 /* Restore the ARGLIST to its full size. */
6938 TREE_VEC_LENGTH (arglist) = saved_depth;
6940 arglist = bound_args;
6944 = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parmlist),
6945 INNERMOST_TEMPLATE_ARGS (arglist),
6948 /*require_all_args=*/true,
6949 /*use_default_args=*/true);
6951 if (arglist == error_mark_node)
6952 /* We were unable to bind the arguments. */
6953 return error_mark_node;
6955 /* In the scope of a template class, explicit references to the
6956 template class refer to the type of the template, not any
6957 instantiation of it. For example, in:
6959 template <class T> class C { void f(C<T>); }
6961 the `C<T>' is just the same as `C'. Outside of the
6962 class, however, such a reference is an instantiation. */
6964 || !PRIMARY_TEMPLATE_P (gen_tmpl)
6965 || currently_open_class (template_type))
6966 /* comp_template_args is expensive, check it last. */
6967 && comp_template_args (TYPE_TI_ARGS (template_type),
6969 return template_type;
6971 /* If we already have this specialization, return it. */
6972 elt.tmpl = gen_tmpl;
6974 hash = hash_specialization (&elt);
6975 entry = (spec_entry *) htab_find_with_hash (type_specializations,
6981 is_dependent_type = uses_template_parms (arglist);
6983 /* If the deduced arguments are invalid, then the binding
6985 if (!is_dependent_type
6986 && check_instantiated_args (gen_tmpl,
6987 INNERMOST_TEMPLATE_ARGS (arglist),
6989 return error_mark_node;
6991 if (!is_dependent_type
6992 && !PRIMARY_TEMPLATE_P (gen_tmpl)
6993 && !LAMBDA_TYPE_P (TREE_TYPE (gen_tmpl))
6994 && TREE_CODE (CP_DECL_CONTEXT (gen_tmpl)) == NAMESPACE_DECL)
6996 found = xref_tag_from_type (TREE_TYPE (gen_tmpl),
6997 DECL_NAME (gen_tmpl),
6998 /*tag_scope=*/ts_global);
7002 context = tsubst (DECL_CONTEXT (gen_tmpl), arglist,
7005 context = global_namespace;
7007 /* Create the type. */
7008 if (TREE_CODE (template_type) == ENUMERAL_TYPE)
7010 if (!is_dependent_type)
7012 set_current_access_from_decl (TYPE_NAME (template_type));
7013 t = start_enum (TYPE_IDENTIFIER (template_type), NULL_TREE,
7014 tsubst (ENUM_UNDERLYING_TYPE (template_type),
7015 arglist, complain, in_decl),
7016 SCOPED_ENUM_P (template_type), NULL);
7020 /* We don't want to call start_enum for this type, since
7021 the values for the enumeration constants may involve
7022 template parameters. And, no one should be interested
7023 in the enumeration constants for such a type. */
7024 t = cxx_make_type (ENUMERAL_TYPE);
7025 SET_SCOPED_ENUM_P (t, SCOPED_ENUM_P (template_type));
7027 SET_OPAQUE_ENUM_P (t, OPAQUE_ENUM_P (template_type));
7028 ENUM_FIXED_UNDERLYING_TYPE_P (t)
7029 = ENUM_FIXED_UNDERLYING_TYPE_P (template_type);
7033 t = make_class_type (TREE_CODE (template_type));
7034 CLASSTYPE_DECLARED_CLASS (t)
7035 = CLASSTYPE_DECLARED_CLASS (template_type);
7036 SET_CLASSTYPE_IMPLICIT_INSTANTIATION (t);
7037 TYPE_FOR_JAVA (t) = TYPE_FOR_JAVA (template_type);
7039 /* A local class. Make sure the decl gets registered properly. */
7040 if (context == current_function_decl)
7041 pushtag (DECL_NAME (gen_tmpl), t, /*tag_scope=*/ts_current);
7043 if (comp_template_args (CLASSTYPE_TI_ARGS (template_type), arglist))
7044 /* This instantiation is another name for the primary
7045 template type. Set the TYPE_CANONICAL field
7047 TYPE_CANONICAL (t) = template_type;
7048 else if (any_template_arguments_need_structural_equality_p (arglist))
7049 /* Some of the template arguments require structural
7050 equality testing, so this template class requires
7051 structural equality testing. */
7052 SET_TYPE_STRUCTURAL_EQUALITY (t);
7055 /* If we called start_enum or pushtag above, this information
7056 will already be set up. */
7059 TYPE_CONTEXT (t) = FROB_CONTEXT (context);
7061 type_decl = create_implicit_typedef (DECL_NAME (gen_tmpl), t);
7062 DECL_CONTEXT (type_decl) = TYPE_CONTEXT (t);
7063 DECL_SOURCE_LOCATION (type_decl)
7064 = DECL_SOURCE_LOCATION (TYPE_STUB_DECL (template_type));
7067 type_decl = TYPE_NAME (t);
7069 TREE_PRIVATE (type_decl)
7070 = TREE_PRIVATE (TYPE_STUB_DECL (template_type));
7071 TREE_PROTECTED (type_decl)
7072 = TREE_PROTECTED (TYPE_STUB_DECL (template_type));
7073 if (CLASSTYPE_VISIBILITY_SPECIFIED (template_type))
7075 DECL_VISIBILITY_SPECIFIED (type_decl) = 1;
7076 DECL_VISIBILITY (type_decl) = CLASSTYPE_VISIBILITY (template_type);
7079 /* Let's consider the explicit specialization of a member
7080 of a class template specialization that is implicitely instantiated,
7085 template<class U> struct M {}; //#0
7090 struct S<int>::M<char> //#1
7094 [temp.expl.spec]/4 says this is valid.
7096 In this case, when we write:
7099 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7102 When we encounter #1, we want to store the partial instantiation
7103 of M (template<class T> S<int>::M<T>) in it's CLASSTYPE_TI_TEMPLATE.
7105 For all cases other than this "explicit specialization of member of a
7106 class template", we just want to store the most general template into
7107 the CLASSTYPE_TI_TEMPLATE of M.
7109 This case of "explicit specialization of member of a class template"
7111 1/ the enclosing class is an instantiation of, and therefore not
7112 the same as, the context of the most general template, and
7113 2/ we aren't looking at the partial instantiation itself, i.e.
7114 the innermost arguments are not the same as the innermost parms of
7115 the most general template.
7117 So it's only when 1/ and 2/ happens that we want to use the partial
7118 instantiation of the member template in lieu of its most general
7121 if (PRIMARY_TEMPLATE_P (gen_tmpl)
7122 && TMPL_ARGS_HAVE_MULTIPLE_LEVELS (arglist)
7123 /* the enclosing class must be an instantiation... */
7124 && CLASS_TYPE_P (context)
7125 && !same_type_p (context, DECL_CONTEXT (gen_tmpl)))
7127 tree partial_inst_args;
7128 TREE_VEC_LENGTH (arglist)--;
7129 ++processing_template_decl;
7131 tsubst (INNERMOST_TEMPLATE_ARGS
7132 (CLASSTYPE_TI_ARGS (TREE_TYPE (gen_tmpl))),
7133 arglist, complain, NULL_TREE);
7134 --processing_template_decl;
7135 TREE_VEC_LENGTH (arglist)++;
7136 use_partial_inst_tmpl =
7137 /*...and we must not be looking at the partial instantiation
7139 !comp_template_args (INNERMOST_TEMPLATE_ARGS (arglist),
7143 if (!use_partial_inst_tmpl)
7144 /* This case is easy; there are no member templates involved. */
7148 /* This is a full instantiation of a member template. Find
7149 the partial instantiation of which this is an instance. */
7151 /* Temporarily reduce by one the number of levels in the ARGLIST
7152 so as to avoid comparing the last set of arguments. */
7153 TREE_VEC_LENGTH (arglist)--;
7154 found = tsubst (gen_tmpl, arglist, complain, NULL_TREE);
7155 TREE_VEC_LENGTH (arglist)++;
7156 found = CLASSTYPE_TI_TEMPLATE (found);
7159 SET_TYPE_TEMPLATE_INFO (t, build_template_info (found, arglist));
7162 slot = (spec_entry **) htab_find_slot_with_hash (type_specializations,
7163 &elt, hash, INSERT);
7164 *slot = ggc_alloc_spec_entry ();
7167 /* Note this use of the partial instantiation so we can check it
7168 later in maybe_process_partial_specialization. */
7169 DECL_TEMPLATE_INSTANTIATIONS (templ)
7170 = tree_cons (arglist, t,
7171 DECL_TEMPLATE_INSTANTIATIONS (templ));
7173 if (TREE_CODE (t) == ENUMERAL_TYPE && !is_dependent_type)
7174 /* Now that the type has been registered on the instantiations
7175 list, we set up the enumerators. Because the enumeration
7176 constants may involve the enumeration type itself, we make
7177 sure to register the type first, and then create the
7178 constants. That way, doing tsubst_expr for the enumeration
7179 constants won't result in recursive calls here; we'll find
7180 the instantiation and exit above. */
7181 tsubst_enum (template_type, t, arglist);
7183 if (is_dependent_type)
7184 /* If the type makes use of template parameters, the
7185 code that generates debugging information will crash. */
7186 DECL_IGNORED_P (TYPE_STUB_DECL (t)) = 1;
7188 /* Possibly limit visibility based on template args. */
7189 TREE_PUBLIC (type_decl) = 1;
7190 determine_visibility (type_decl);
7196 /* Wrapper for lookup_template_class_1. */
7199 lookup_template_class (tree d1, tree arglist, tree in_decl, tree context,
7200 int entering_scope, tsubst_flags_t complain)
7203 timevar_push (TV_TEMPLATE_INST);
7204 ret = lookup_template_class_1 (d1, arglist, in_decl, context,
7205 entering_scope, complain);
7206 timevar_pop (TV_TEMPLATE_INST);
7214 /* True when we should also visit template parameters that occur in
7215 non-deduced contexts. */
7216 bool include_nondeduced_p;
7217 struct pointer_set_t *visited;
7220 /* Called from for_each_template_parm via walk_tree. */
7223 for_each_template_parm_r (tree *tp, int *walk_subtrees, void *d)
7226 struct pair_fn_data *pfd = (struct pair_fn_data *) d;
7227 tree_fn_t fn = pfd->fn;
7228 void *data = pfd->data;
7231 && (pfd->include_nondeduced_p || TREE_CODE (t) != TYPENAME_TYPE)
7232 && for_each_template_parm (TYPE_CONTEXT (t), fn, data, pfd->visited,
7233 pfd->include_nondeduced_p))
7234 return error_mark_node;
7236 switch (TREE_CODE (t))
7239 if (TYPE_PTRMEMFUNC_P (t))
7245 if (!TYPE_TEMPLATE_INFO (t))
7247 else if (for_each_template_parm (TI_ARGS (TYPE_TEMPLATE_INFO (t)),
7248 fn, data, pfd->visited,
7249 pfd->include_nondeduced_p))
7250 return error_mark_node;
7254 if (for_each_template_parm (TYPE_MIN_VALUE (t),
7255 fn, data, pfd->visited,
7256 pfd->include_nondeduced_p)
7257 || for_each_template_parm (TYPE_MAX_VALUE (t),
7258 fn, data, pfd->visited,
7259 pfd->include_nondeduced_p))
7260 return error_mark_node;
7264 /* Since we're not going to walk subtrees, we have to do this
7266 if (for_each_template_parm (TYPE_METHOD_BASETYPE (t), fn, data,
7267 pfd->visited, pfd->include_nondeduced_p))
7268 return error_mark_node;
7272 /* Check the return type. */
7273 if (for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
7274 pfd->include_nondeduced_p))
7275 return error_mark_node;
7277 /* Check the parameter types. Since default arguments are not
7278 instantiated until they are needed, the TYPE_ARG_TYPES may
7279 contain expressions that involve template parameters. But,
7280 no-one should be looking at them yet. And, once they're
7281 instantiated, they don't contain template parameters, so
7282 there's no point in looking at them then, either. */
7286 for (parm = TYPE_ARG_TYPES (t); parm; parm = TREE_CHAIN (parm))
7287 if (for_each_template_parm (TREE_VALUE (parm), fn, data,
7288 pfd->visited, pfd->include_nondeduced_p))
7289 return error_mark_node;
7291 /* Since we've already handled the TYPE_ARG_TYPES, we don't
7292 want walk_tree walking into them itself. */
7298 case UNDERLYING_TYPE:
7299 if (pfd->include_nondeduced_p
7300 && for_each_template_parm (TYPE_FIELDS (t), fn, data,
7302 pfd->include_nondeduced_p))
7303 return error_mark_node;
7308 if (DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t)
7309 && for_each_template_parm (DECL_TI_ARGS (t), fn, data,
7310 pfd->visited, pfd->include_nondeduced_p))
7311 return error_mark_node;
7316 if (TREE_CODE (t) == CONST_DECL && DECL_TEMPLATE_PARM_P (t)
7317 && for_each_template_parm (DECL_INITIAL (t), fn, data,
7318 pfd->visited, pfd->include_nondeduced_p))
7319 return error_mark_node;
7320 if (DECL_CONTEXT (t)
7321 && pfd->include_nondeduced_p
7322 && for_each_template_parm (DECL_CONTEXT (t), fn, data,
7323 pfd->visited, pfd->include_nondeduced_p))
7324 return error_mark_node;
7327 case BOUND_TEMPLATE_TEMPLATE_PARM:
7328 /* Record template parameters such as `T' inside `TT<T>'. */
7329 if (for_each_template_parm (TYPE_TI_ARGS (t), fn, data, pfd->visited,
7330 pfd->include_nondeduced_p))
7331 return error_mark_node;
7334 case TEMPLATE_TEMPLATE_PARM:
7335 case TEMPLATE_TYPE_PARM:
7336 case TEMPLATE_PARM_INDEX:
7337 if (fn && (*fn)(t, data))
7338 return error_mark_node;
7340 return error_mark_node;
7344 /* A template template parameter is encountered. */
7345 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t)
7346 && for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
7347 pfd->include_nondeduced_p))
7348 return error_mark_node;
7350 /* Already substituted template template parameter */
7356 || for_each_template_parm (TYPENAME_TYPE_FULLNAME (t), fn,
7358 pfd->include_nondeduced_p))
7359 return error_mark_node;
7363 if (TREE_TYPE (t) && TYPE_PTRMEMFUNC_P (TREE_TYPE (t))
7364 && pfd->include_nondeduced_p
7365 && for_each_template_parm (TYPE_PTRMEMFUNC_FN_TYPE
7366 (TREE_TYPE (t)), fn, data,
7367 pfd->visited, pfd->include_nondeduced_p))
7368 return error_mark_node;
7373 /* If there's no type, then this thing must be some expression
7374 involving template parameters. */
7375 if (!fn && !TREE_TYPE (t))
7376 return error_mark_node;
7381 case REINTERPRET_CAST_EXPR:
7382 case CONST_CAST_EXPR:
7383 case STATIC_CAST_EXPR:
7384 case DYNAMIC_CAST_EXPR:
7388 case PSEUDO_DTOR_EXPR:
7390 return error_mark_node;
7397 /* We didn't find any template parameters we liked. */
7401 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
7402 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
7403 call FN with the parameter and the DATA.
7404 If FN returns nonzero, the iteration is terminated, and
7405 for_each_template_parm returns 1. Otherwise, the iteration
7406 continues. If FN never returns a nonzero value, the value
7407 returned by for_each_template_parm is 0. If FN is NULL, it is
7408 considered to be the function which always returns 1.
7410 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
7411 parameters that occur in non-deduced contexts. When false, only
7412 visits those template parameters that can be deduced. */
7415 for_each_template_parm (tree t, tree_fn_t fn, void* data,
7416 struct pointer_set_t *visited,
7417 bool include_nondeduced_p)
7419 struct pair_fn_data pfd;
7425 pfd.include_nondeduced_p = include_nondeduced_p;
7427 /* Walk the tree. (Conceptually, we would like to walk without
7428 duplicates, but for_each_template_parm_r recursively calls
7429 for_each_template_parm, so we would need to reorganize a fair
7430 bit to use walk_tree_without_duplicates, so we keep our own
7433 pfd.visited = visited;
7435 pfd.visited = pointer_set_create ();
7436 result = cp_walk_tree (&t,
7437 for_each_template_parm_r,
7439 pfd.visited) != NULL_TREE;
7444 pointer_set_destroy (pfd.visited);
7451 /* Returns true if T depends on any template parameter. */
7454 uses_template_parms (tree t)
7457 int saved_processing_template_decl;
7459 saved_processing_template_decl = processing_template_decl;
7460 if (!saved_processing_template_decl)
7461 processing_template_decl = 1;
7463 dependent_p = dependent_type_p (t);
7464 else if (TREE_CODE (t) == TREE_VEC)
7465 dependent_p = any_dependent_template_arguments_p (t);
7466 else if (TREE_CODE (t) == TREE_LIST)
7467 dependent_p = (uses_template_parms (TREE_VALUE (t))
7468 || uses_template_parms (TREE_CHAIN (t)));
7469 else if (TREE_CODE (t) == TYPE_DECL)
7470 dependent_p = dependent_type_p (TREE_TYPE (t));
7473 || TREE_CODE (t) == TEMPLATE_PARM_INDEX
7474 || TREE_CODE (t) == OVERLOAD
7475 || TREE_CODE (t) == BASELINK
7476 || TREE_CODE (t) == IDENTIFIER_NODE
7477 || TREE_CODE (t) == TRAIT_EXPR
7478 || TREE_CODE (t) == CONSTRUCTOR
7479 || CONSTANT_CLASS_P (t))
7480 dependent_p = (type_dependent_expression_p (t)
7481 || value_dependent_expression_p (t));
7484 gcc_assert (t == error_mark_node);
7485 dependent_p = false;
7488 processing_template_decl = saved_processing_template_decl;
7493 /* Returns true if T depends on any template parameter with level LEVEL. */
7496 uses_template_parms_level (tree t, int level)
7498 return for_each_template_parm (t, template_parm_this_level_p, &level, NULL,
7499 /*include_nondeduced_p=*/true);
7502 static int tinst_depth;
7503 extern int max_tinst_depth;
7504 #ifdef GATHER_STATISTICS
7507 static int tinst_level_tick;
7508 static int last_template_error_tick;
7510 /* We're starting to instantiate D; record the template instantiation context
7511 for diagnostics and to restore it later. */
7514 push_tinst_level (tree d)
7516 struct tinst_level *new_level;
7518 if (tinst_depth >= max_tinst_depth)
7520 last_template_error_tick = tinst_level_tick;
7521 if (TREE_CODE (d) == TREE_LIST)
7522 error ("template instantiation depth exceeds maximum of %d (use "
7523 "-ftemplate-depth= to increase the maximum) substituting %qS",
7524 max_tinst_depth, d);
7526 error ("template instantiation depth exceeds maximum of %d (use "
7527 "-ftemplate-depth= to increase the maximum) instantiating %qD",
7528 max_tinst_depth, d);
7530 print_instantiation_context ();
7535 new_level = ggc_alloc_tinst_level ();
7536 new_level->decl = d;
7537 new_level->locus = input_location;
7538 new_level->in_system_header_p = in_system_header;
7539 new_level->next = current_tinst_level;
7540 current_tinst_level = new_level;
7543 #ifdef GATHER_STATISTICS
7544 if (tinst_depth > depth_reached)
7545 depth_reached = tinst_depth;
7552 /* We're done instantiating this template; return to the instantiation
7556 pop_tinst_level (void)
7558 /* Restore the filename and line number stashed away when we started
7559 this instantiation. */
7560 input_location = current_tinst_level->locus;
7561 current_tinst_level = current_tinst_level->next;
7566 /* We're instantiating a deferred template; restore the template
7567 instantiation context in which the instantiation was requested, which
7568 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
7571 reopen_tinst_level (struct tinst_level *level)
7573 struct tinst_level *t;
7576 for (t = level; t; t = t->next)
7579 current_tinst_level = level;
7584 /* Returns the TINST_LEVEL which gives the original instantiation
7587 struct tinst_level *
7588 outermost_tinst_level (void)
7590 struct tinst_level *level = current_tinst_level;
7593 level = level->next;
7597 /* Returns TRUE if PARM is a parameter of the template TEMPL. */
7600 parameter_of_template_p (tree parm, tree templ)
7605 if (!parm || !templ)
7608 gcc_assert (DECL_TEMPLATE_PARM_P (parm));
7609 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
7611 parms = DECL_TEMPLATE_PARMS (templ);
7612 parms = INNERMOST_TEMPLATE_PARMS (parms);
7614 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
7615 if (parm == TREE_VALUE (TREE_VEC_ELT (parms, i)))
7621 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
7622 vector of template arguments, as for tsubst.
7624 Returns an appropriate tsubst'd friend declaration. */
7627 tsubst_friend_function (tree decl, tree args)
7631 if (TREE_CODE (decl) == FUNCTION_DECL
7632 && DECL_TEMPLATE_INSTANTIATION (decl)
7633 && TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
7634 /* This was a friend declared with an explicit template
7635 argument list, e.g.:
7639 to indicate that f was a template instantiation, not a new
7640 function declaration. Now, we have to figure out what
7641 instantiation of what template. */
7643 tree template_id, arglist, fns;
7646 tree ns = decl_namespace_context (TYPE_MAIN_DECL (current_class_type));
7648 /* Friend functions are looked up in the containing namespace scope.
7649 We must enter that scope, to avoid finding member functions of the
7650 current class with same name. */
7651 push_nested_namespace (ns);
7652 fns = tsubst_expr (DECL_TI_TEMPLATE (decl), args,
7653 tf_warning_or_error, NULL_TREE,
7654 /*integral_constant_expression_p=*/false);
7655 pop_nested_namespace (ns);
7656 arglist = tsubst (DECL_TI_ARGS (decl), args,
7657 tf_warning_or_error, NULL_TREE);
7658 template_id = lookup_template_function (fns, arglist);
7660 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
7661 tmpl = determine_specialization (template_id, new_friend,
7663 /*need_member_template=*/0,
7664 TREE_VEC_LENGTH (args),
7666 return instantiate_template (tmpl, new_args, tf_error);
7669 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
7671 /* The NEW_FRIEND will look like an instantiation, to the
7672 compiler, but is not an instantiation from the point of view of
7673 the language. For example, we might have had:
7675 template <class T> struct S {
7676 template <class U> friend void f(T, U);
7679 Then, in S<int>, template <class U> void f(int, U) is not an
7680 instantiation of anything. */
7681 if (new_friend == error_mark_node)
7682 return error_mark_node;
7684 DECL_USE_TEMPLATE (new_friend) = 0;
7685 if (TREE_CODE (decl) == TEMPLATE_DECL)
7687 DECL_USE_TEMPLATE (DECL_TEMPLATE_RESULT (new_friend)) = 0;
7688 DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (new_friend))
7689 = DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (decl));
7692 /* The mangled name for the NEW_FRIEND is incorrect. The function
7693 is not a template instantiation and should not be mangled like
7694 one. Therefore, we forget the mangling here; we'll recompute it
7695 later if we need it. */
7696 if (TREE_CODE (new_friend) != TEMPLATE_DECL)
7698 SET_DECL_RTL (new_friend, NULL);
7699 SET_DECL_ASSEMBLER_NAME (new_friend, NULL_TREE);
7702 if (DECL_NAMESPACE_SCOPE_P (new_friend))
7705 tree new_friend_template_info;
7706 tree new_friend_result_template_info;
7708 int new_friend_is_defn;
7710 /* We must save some information from NEW_FRIEND before calling
7711 duplicate decls since that function will free NEW_FRIEND if
7713 new_friend_template_info = DECL_TEMPLATE_INFO (new_friend);
7714 new_friend_is_defn =
7715 (DECL_INITIAL (DECL_TEMPLATE_RESULT
7716 (template_for_substitution (new_friend)))
7718 if (TREE_CODE (new_friend) == TEMPLATE_DECL)
7720 /* This declaration is a `primary' template. */
7721 DECL_PRIMARY_TEMPLATE (new_friend) = new_friend;
7723 new_friend_result_template_info
7724 = DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (new_friend));
7727 new_friend_result_template_info = NULL_TREE;
7729 /* Make the init_value nonzero so pushdecl knows this is a defn. */
7730 if (new_friend_is_defn)
7731 DECL_INITIAL (new_friend) = error_mark_node;
7733 /* Inside pushdecl_namespace_level, we will push into the
7734 current namespace. However, the friend function should go
7735 into the namespace of the template. */
7736 ns = decl_namespace_context (new_friend);
7737 push_nested_namespace (ns);
7738 old_decl = pushdecl_namespace_level (new_friend, /*is_friend=*/true);
7739 pop_nested_namespace (ns);
7741 if (old_decl == error_mark_node)
7742 return error_mark_node;
7744 if (old_decl != new_friend)
7746 /* This new friend declaration matched an existing
7747 declaration. For example, given:
7749 template <class T> void f(T);
7750 template <class U> class C {
7751 template <class T> friend void f(T) {}
7754 the friend declaration actually provides the definition
7755 of `f', once C has been instantiated for some type. So,
7756 old_decl will be the out-of-class template declaration,
7757 while new_friend is the in-class definition.
7759 But, if `f' was called before this point, the
7760 instantiation of `f' will have DECL_TI_ARGS corresponding
7761 to `T' but not to `U', references to which might appear
7762 in the definition of `f'. Previously, the most general
7763 template for an instantiation of `f' was the out-of-class
7764 version; now it is the in-class version. Therefore, we
7765 run through all specialization of `f', adding to their
7766 DECL_TI_ARGS appropriately. In particular, they need a
7767 new set of outer arguments, corresponding to the
7768 arguments for this class instantiation.
7770 The same situation can arise with something like this:
7773 template <class T> class C {
7777 when `C<int>' is instantiated. Now, `f(int)' is defined
7780 if (!new_friend_is_defn)
7781 /* On the other hand, if the in-class declaration does
7782 *not* provide a definition, then we don't want to alter
7783 existing definitions. We can just leave everything
7788 tree new_template = TI_TEMPLATE (new_friend_template_info);
7789 tree new_args = TI_ARGS (new_friend_template_info);
7791 /* Overwrite whatever template info was there before, if
7792 any, with the new template information pertaining to
7794 DECL_TEMPLATE_INFO (old_decl) = new_friend_template_info;
7796 if (TREE_CODE (old_decl) != TEMPLATE_DECL)
7798 /* We should have called reregister_specialization in
7800 gcc_assert (retrieve_specialization (new_template,
7804 /* Instantiate it if the global has already been used. */
7805 if (DECL_ODR_USED (old_decl))
7806 instantiate_decl (old_decl, /*defer_ok=*/true,
7807 /*expl_inst_class_mem_p=*/false);
7813 /* Indicate that the old function template is a partial
7815 DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (old_decl))
7816 = new_friend_result_template_info;
7818 gcc_assert (new_template
7819 == most_general_template (new_template));
7820 gcc_assert (new_template != old_decl);
7822 /* Reassign any specializations already in the hash table
7823 to the new more general template, and add the
7824 additional template args. */
7825 for (t = DECL_TEMPLATE_INSTANTIATIONS (old_decl);
7829 tree spec = TREE_VALUE (t);
7832 elt.tmpl = old_decl;
7833 elt.args = DECL_TI_ARGS (spec);
7834 elt.spec = NULL_TREE;
7836 htab_remove_elt (decl_specializations, &elt);
7839 = add_outermost_template_args (new_args,
7840 DECL_TI_ARGS (spec));
7842 register_specialization
7843 (spec, new_template, DECL_TI_ARGS (spec), true, 0);
7846 DECL_TEMPLATE_INSTANTIATIONS (old_decl) = NULL_TREE;
7850 /* The information from NEW_FRIEND has been merged into OLD_DECL
7851 by duplicate_decls. */
7852 new_friend = old_decl;
7857 tree context = DECL_CONTEXT (new_friend);
7861 template <class T> class C {
7862 template <class U> friend void C1<U>::f (); // case 1
7863 friend void C2<T>::f (); // case 2
7865 we only need to make sure CONTEXT is a complete type for
7866 case 2. To distinguish between the two cases, we note that
7867 CONTEXT of case 1 remains dependent type after tsubst while
7868 this isn't true for case 2. */
7869 ++processing_template_decl;
7870 dependent_p = dependent_type_p (context);
7871 --processing_template_decl;
7874 && !complete_type_or_else (context, NULL_TREE))
7875 return error_mark_node;
7877 if (COMPLETE_TYPE_P (context))
7879 /* Check to see that the declaration is really present, and,
7880 possibly obtain an improved declaration. */
7881 tree fn = check_classfn (context,
7882 new_friend, NULL_TREE);
7892 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
7893 template arguments, as for tsubst.
7895 Returns an appropriate tsubst'd friend type or error_mark_node on
7899 tsubst_friend_class (tree friend_tmpl, tree args)
7905 context = CP_DECL_CONTEXT (friend_tmpl);
7907 if (context != global_namespace)
7909 if (TREE_CODE (context) == NAMESPACE_DECL)
7910 push_nested_namespace (context);
7912 push_nested_class (tsubst (context, args, tf_none, NULL_TREE));
7915 /* Look for a class template declaration. We look for hidden names
7916 because two friend declarations of the same template are the
7917 same. For example, in:
7920 template <typename> friend class F;
7922 template <typename> struct B {
7923 template <typename> friend class F;
7926 both F templates are the same. */
7927 tmpl = lookup_name_real (DECL_NAME (friend_tmpl), 0, 0,
7928 /*block_p=*/true, 0,
7929 LOOKUP_COMPLAIN | LOOKUP_HIDDEN);
7931 /* But, if we don't find one, it might be because we're in a
7932 situation like this:
7940 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
7941 for `S<int>', not the TEMPLATE_DECL. */
7942 if (!tmpl || !DECL_CLASS_TEMPLATE_P (tmpl))
7944 tmpl = lookup_name_prefer_type (DECL_NAME (friend_tmpl), 1);
7945 tmpl = maybe_get_template_decl_from_type_decl (tmpl);
7948 if (tmpl && DECL_CLASS_TEMPLATE_P (tmpl))
7950 /* The friend template has already been declared. Just
7951 check to see that the declarations match, and install any new
7952 default parameters. We must tsubst the default parameters,
7953 of course. We only need the innermost template parameters
7954 because that is all that redeclare_class_template will look
7956 if (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (friend_tmpl))
7957 > TMPL_ARGS_DEPTH (args))
7960 location_t saved_input_location;
7961 parms = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_tmpl),
7962 args, tf_warning_or_error);
7964 saved_input_location = input_location;
7965 input_location = DECL_SOURCE_LOCATION (friend_tmpl);
7966 redeclare_class_template (TREE_TYPE (tmpl), parms);
7967 input_location = saved_input_location;
7971 friend_type = TREE_TYPE (tmpl);
7975 /* The friend template has not already been declared. In this
7976 case, the instantiation of the template class will cause the
7977 injection of this template into the global scope. */
7978 tmpl = tsubst (friend_tmpl, args, tf_warning_or_error, NULL_TREE);
7979 if (tmpl == error_mark_node)
7980 return error_mark_node;
7982 /* The new TMPL is not an instantiation of anything, so we
7983 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
7984 the new type because that is supposed to be the corresponding
7985 template decl, i.e., TMPL. */
7986 DECL_USE_TEMPLATE (tmpl) = 0;
7987 DECL_TEMPLATE_INFO (tmpl) = NULL_TREE;
7988 CLASSTYPE_USE_TEMPLATE (TREE_TYPE (tmpl)) = 0;
7989 CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl))
7990 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl)));
7992 /* Inject this template into the global scope. */
7993 friend_type = TREE_TYPE (pushdecl_top_level_maybe_friend (tmpl, true));
7996 if (context != global_namespace)
7998 if (TREE_CODE (context) == NAMESPACE_DECL)
7999 pop_nested_namespace (context);
8001 pop_nested_class ();
8007 /* Returns zero if TYPE cannot be completed later due to circularity.
8008 Otherwise returns one. */
8011 can_complete_type_without_circularity (tree type)
8013 if (type == NULL_TREE || type == error_mark_node)
8015 else if (COMPLETE_TYPE_P (type))
8017 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
8018 return can_complete_type_without_circularity (TREE_TYPE (type));
8019 else if (CLASS_TYPE_P (type)
8020 && TYPE_BEING_DEFINED (TYPE_MAIN_VARIANT (type)))
8026 /* Apply any attributes which had to be deferred until instantiation
8027 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
8028 ARGS, COMPLAIN, IN_DECL are as tsubst. */
8031 apply_late_template_attributes (tree *decl_p, tree attributes, int attr_flags,
8032 tree args, tsubst_flags_t complain, tree in_decl)
8034 tree last_dep = NULL_TREE;
8038 for (t = attributes; t; t = TREE_CHAIN (t))
8039 if (ATTR_IS_DEPENDENT (t))
8042 attributes = copy_list (attributes);
8046 if (DECL_P (*decl_p))
8048 if (TREE_TYPE (*decl_p) == error_mark_node)
8050 p = &DECL_ATTRIBUTES (*decl_p);
8053 p = &TYPE_ATTRIBUTES (*decl_p);
8057 tree late_attrs = NULL_TREE;
8058 tree *q = &late_attrs;
8060 for (*p = attributes; *p; )
8063 if (ATTR_IS_DEPENDENT (t))
8065 *p = TREE_CHAIN (t);
8066 TREE_CHAIN (t) = NULL_TREE;
8067 /* If the first attribute argument is an identifier, don't
8068 pass it through tsubst. Attributes like mode, format,
8069 cleanup and several target specific attributes expect it
8072 && TREE_CODE (TREE_VALUE (t)) == TREE_LIST
8073 && TREE_VALUE (TREE_VALUE (t))
8074 && (TREE_CODE (TREE_VALUE (TREE_VALUE (t)))
8075 == IDENTIFIER_NODE))
8078 = tsubst_expr (TREE_CHAIN (TREE_VALUE (t)), args, complain,
8080 /*integral_constant_expression_p=*/false);
8081 if (chain != TREE_CHAIN (TREE_VALUE (t)))
8083 = tree_cons (NULL_TREE, TREE_VALUE (TREE_VALUE (t)),
8088 = tsubst_expr (TREE_VALUE (t), args, complain, in_decl,
8089 /*integral_constant_expression_p=*/false);
8091 q = &TREE_CHAIN (t);
8094 p = &TREE_CHAIN (t);
8097 cplus_decl_attributes (decl_p, late_attrs, attr_flags);
8101 /* Perform (or defer) access check for typedefs that were referenced
8102 from within the template TMPL code.
8103 This is a subroutine of instantiate_template and instantiate_class_template.
8104 TMPL is the template to consider and TARGS is the list of arguments of
8108 perform_typedefs_access_check (tree tmpl, tree targs)
8110 location_t saved_location;
8112 qualified_typedef_usage_t *iter;
8115 || (!CLASS_TYPE_P (tmpl)
8116 && TREE_CODE (tmpl) != FUNCTION_DECL))
8119 saved_location = input_location;
8120 FOR_EACH_VEC_ELT (qualified_typedef_usage_t,
8121 get_types_needing_access_check (tmpl),
8124 tree type_decl = iter->typedef_decl;
8125 tree type_scope = iter->context;
8127 if (!type_decl || !type_scope || !CLASS_TYPE_P (type_scope))
8130 if (uses_template_parms (type_decl))
8131 type_decl = tsubst (type_decl, targs, tf_error, NULL_TREE);
8132 if (uses_template_parms (type_scope))
8133 type_scope = tsubst (type_scope, targs, tf_error, NULL_TREE);
8135 /* Make access check error messages point to the location
8136 of the use of the typedef. */
8137 input_location = iter->locus;
8138 perform_or_defer_access_check (TYPE_BINFO (type_scope),
8139 type_decl, type_decl);
8141 input_location = saved_location;
8145 instantiate_class_template_1 (tree type)
8147 tree templ, args, pattern, t, member;
8151 unsigned int saved_maximum_field_alignment;
8153 if (type == error_mark_node)
8154 return error_mark_node;
8156 if (COMPLETE_OR_OPEN_TYPE_P (type)
8157 || uses_template_parms (type))
8160 /* Figure out which template is being instantiated. */
8161 templ = most_general_template (CLASSTYPE_TI_TEMPLATE (type));
8162 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
8164 /* Determine what specialization of the original template to
8166 t = most_specialized_class (type, templ, tf_warning_or_error);
8167 if (t == error_mark_node)
8169 TYPE_BEING_DEFINED (type) = 1;
8170 return error_mark_node;
8174 /* This TYPE is actually an instantiation of a partial
8175 specialization. We replace the innermost set of ARGS with
8176 the arguments appropriate for substitution. For example,
8179 template <class T> struct S {};
8180 template <class T> struct S<T*> {};
8182 and supposing that we are instantiating S<int*>, ARGS will
8183 presently be {int*} -- but we need {int}. */
8184 pattern = TREE_TYPE (t);
8185 args = TREE_PURPOSE (t);
8189 pattern = TREE_TYPE (templ);
8190 args = CLASSTYPE_TI_ARGS (type);
8193 /* If the template we're instantiating is incomplete, then clearly
8194 there's nothing we can do. */
8195 if (!COMPLETE_TYPE_P (pattern))
8198 /* If we've recursively instantiated too many templates, stop. */
8199 if (! push_tinst_level (type))
8202 /* Now we're really doing the instantiation. Mark the type as in
8203 the process of being defined. */
8204 TYPE_BEING_DEFINED (type) = 1;
8206 /* We may be in the middle of deferred access check. Disable
8208 push_deferring_access_checks (dk_no_deferred);
8210 push_to_top_level ();
8211 /* Use #pragma pack from the template context. */
8212 saved_maximum_field_alignment = maximum_field_alignment;
8213 maximum_field_alignment = TYPE_PRECISION (pattern);
8215 SET_CLASSTYPE_INTERFACE_UNKNOWN (type);
8217 /* Set the input location to the most specialized template definition.
8218 This is needed if tsubsting causes an error. */
8219 typedecl = TYPE_MAIN_DECL (pattern);
8220 input_location = DECL_SOURCE_LOCATION (TYPE_NAME (type)) =
8221 DECL_SOURCE_LOCATION (typedecl);
8223 TYPE_HAS_USER_CONSTRUCTOR (type) = TYPE_HAS_USER_CONSTRUCTOR (pattern);
8224 TYPE_HAS_NEW_OPERATOR (type) = TYPE_HAS_NEW_OPERATOR (pattern);
8225 TYPE_HAS_ARRAY_NEW_OPERATOR (type) = TYPE_HAS_ARRAY_NEW_OPERATOR (pattern);
8226 TYPE_GETS_DELETE (type) = TYPE_GETS_DELETE (pattern);
8227 TYPE_HAS_COPY_ASSIGN (type) = TYPE_HAS_COPY_ASSIGN (pattern);
8228 TYPE_HAS_CONST_COPY_ASSIGN (type) = TYPE_HAS_CONST_COPY_ASSIGN (pattern);
8229 TYPE_HAS_COPY_CTOR (type) = TYPE_HAS_COPY_CTOR (pattern);
8230 TYPE_HAS_CONST_COPY_CTOR (type) = TYPE_HAS_CONST_COPY_CTOR (pattern);
8231 TYPE_HAS_DEFAULT_CONSTRUCTOR (type) = TYPE_HAS_DEFAULT_CONSTRUCTOR (pattern);
8232 TYPE_HAS_CONVERSION (type) = TYPE_HAS_CONVERSION (pattern);
8233 TYPE_PACKED (type) = TYPE_PACKED (pattern);
8234 TYPE_ALIGN (type) = TYPE_ALIGN (pattern);
8235 TYPE_USER_ALIGN (type) = TYPE_USER_ALIGN (pattern);
8236 TYPE_FOR_JAVA (type) = TYPE_FOR_JAVA (pattern); /* For libjava's JArray<T> */
8237 if (ANON_AGGR_TYPE_P (pattern))
8238 SET_ANON_AGGR_TYPE_P (type);
8239 if (CLASSTYPE_VISIBILITY_SPECIFIED (pattern))
8241 CLASSTYPE_VISIBILITY_SPECIFIED (type) = 1;
8242 CLASSTYPE_VISIBILITY (type) = CLASSTYPE_VISIBILITY (pattern);
8244 CLASSTYPE_FINAL (type) = CLASSTYPE_FINAL (pattern);
8246 pbinfo = TYPE_BINFO (pattern);
8248 /* We should never instantiate a nested class before its enclosing
8249 class; we need to look up the nested class by name before we can
8250 instantiate it, and that lookup should instantiate the enclosing
8252 gcc_assert (!DECL_CLASS_SCOPE_P (TYPE_MAIN_DECL (pattern))
8253 || COMPLETE_OR_OPEN_TYPE_P (TYPE_CONTEXT (type)));
8255 base_list = NULL_TREE;
8256 if (BINFO_N_BASE_BINFOS (pbinfo))
8262 /* We must enter the scope containing the type, as that is where
8263 the accessibility of types named in dependent bases are
8265 pushed_scope = push_scope (CP_TYPE_CONTEXT (type));
8267 /* Substitute into each of the bases to determine the actual
8269 for (i = 0; BINFO_BASE_ITERATE (pbinfo, i, pbase_binfo); i++)
8272 tree access = BINFO_BASE_ACCESS (pbinfo, i);
8273 tree expanded_bases = NULL_TREE;
8276 if (PACK_EXPANSION_P (BINFO_TYPE (pbase_binfo)))
8279 tsubst_pack_expansion (BINFO_TYPE (pbase_binfo),
8280 args, tf_error, NULL_TREE);
8281 if (expanded_bases == error_mark_node)
8284 len = TREE_VEC_LENGTH (expanded_bases);
8287 for (idx = 0; idx < len; idx++)
8290 /* Extract the already-expanded base class. */
8291 base = TREE_VEC_ELT (expanded_bases, idx);
8293 /* Substitute to figure out the base class. */
8294 base = tsubst (BINFO_TYPE (pbase_binfo), args, tf_error,
8297 if (base == error_mark_node)
8300 base_list = tree_cons (access, base, base_list);
8301 if (BINFO_VIRTUAL_P (pbase_binfo))
8302 TREE_TYPE (base_list) = integer_type_node;
8306 /* The list is now in reverse order; correct that. */
8307 base_list = nreverse (base_list);
8310 pop_scope (pushed_scope);
8312 /* Now call xref_basetypes to set up all the base-class
8314 xref_basetypes (type, base_list);
8316 apply_late_template_attributes (&type, TYPE_ATTRIBUTES (pattern),
8317 (int) ATTR_FLAG_TYPE_IN_PLACE,
8318 args, tf_error, NULL_TREE);
8319 fixup_attribute_variants (type);
8321 /* Now that our base classes are set up, enter the scope of the
8322 class, so that name lookups into base classes, etc. will work
8323 correctly. This is precisely analogous to what we do in
8324 begin_class_definition when defining an ordinary non-template
8325 class, except we also need to push the enclosing classes. */
8326 push_nested_class (type);
8328 /* Now members are processed in the order of declaration. */
8329 for (member = CLASSTYPE_DECL_LIST (pattern);
8330 member; member = TREE_CHAIN (member))
8332 tree t = TREE_VALUE (member);
8334 if (TREE_PURPOSE (member))
8338 /* Build new CLASSTYPE_NESTED_UTDS. */
8341 bool class_template_p;
8343 class_template_p = (TREE_CODE (t) != ENUMERAL_TYPE
8344 && TYPE_LANG_SPECIFIC (t)
8345 && CLASSTYPE_IS_TEMPLATE (t));
8346 /* If the member is a class template, then -- even after
8347 substitution -- there may be dependent types in the
8348 template argument list for the class. We increment
8349 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
8350 that function will assume that no types are dependent
8351 when outside of a template. */
8352 if (class_template_p)
8353 ++processing_template_decl;
8354 newtag = tsubst (t, args, tf_error, NULL_TREE);
8355 if (class_template_p)
8356 --processing_template_decl;
8357 if (newtag == error_mark_node)
8360 if (TREE_CODE (newtag) != ENUMERAL_TYPE)
8362 tree name = TYPE_IDENTIFIER (t);
8364 if (class_template_p)
8365 /* Unfortunately, lookup_template_class sets
8366 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
8367 instantiation (i.e., for the type of a member
8368 template class nested within a template class.)
8369 This behavior is required for
8370 maybe_process_partial_specialization to work
8371 correctly, but is not accurate in this case;
8372 the TAG is not an instantiation of anything.
8373 (The corresponding TEMPLATE_DECL is an
8374 instantiation, but the TYPE is not.) */
8375 CLASSTYPE_USE_TEMPLATE (newtag) = 0;
8377 /* Now, we call pushtag to put this NEWTAG into the scope of
8378 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
8379 pushtag calling push_template_decl. We don't have to do
8380 this for enums because it will already have been done in
8383 SET_IDENTIFIER_TYPE_VALUE (name, newtag);
8384 pushtag (name, newtag, /*tag_scope=*/ts_current);
8387 else if (TREE_CODE (t) == FUNCTION_DECL
8388 || DECL_FUNCTION_TEMPLATE_P (t))
8390 /* Build new TYPE_METHODS. */
8393 if (TREE_CODE (t) == TEMPLATE_DECL)
8394 ++processing_template_decl;
8395 r = tsubst (t, args, tf_error, NULL_TREE);
8396 if (TREE_CODE (t) == TEMPLATE_DECL)
8397 --processing_template_decl;
8398 set_current_access_from_decl (r);
8399 finish_member_declaration (r);
8403 /* Build new TYPE_FIELDS. */
8404 if (TREE_CODE (t) == STATIC_ASSERT)
8407 tsubst_expr (STATIC_ASSERT_CONDITION (t), args,
8408 tf_warning_or_error, NULL_TREE,
8409 /*integral_constant_expression_p=*/true);
8410 finish_static_assert (condition,
8411 STATIC_ASSERT_MESSAGE (t),
8412 STATIC_ASSERT_SOURCE_LOCATION (t),
8415 else if (TREE_CODE (t) != CONST_DECL)
8419 /* The file and line for this declaration, to
8420 assist in error message reporting. Since we
8421 called push_tinst_level above, we don't need to
8423 input_location = DECL_SOURCE_LOCATION (t);
8425 if (TREE_CODE (t) == TEMPLATE_DECL)
8426 ++processing_template_decl;
8427 r = tsubst (t, args, tf_warning_or_error, NULL_TREE);
8428 if (TREE_CODE (t) == TEMPLATE_DECL)
8429 --processing_template_decl;
8430 if (TREE_CODE (r) == VAR_DECL)
8434 [t]he initialization (and any associated
8435 side-effects) of a static data member does
8436 not occur unless the static data member is
8437 itself used in a way that requires the
8438 definition of the static data member to
8441 Therefore, we do not substitute into the
8442 initialized for the static data member here. */
8443 finish_static_data_member_decl
8446 /*init_const_expr_p=*/false,
8447 /*asmspec_tree=*/NULL_TREE,
8450 else if (TREE_CODE (r) == FIELD_DECL)
8452 /* Determine whether R has a valid type and can be
8453 completed later. If R is invalid, then it is
8454 replaced by error_mark_node so that it will not be
8455 added to TYPE_FIELDS. */
8456 tree rtype = TREE_TYPE (r);
8457 if (can_complete_type_without_circularity (rtype))
8458 complete_type (rtype);
8460 if (!COMPLETE_TYPE_P (rtype))
8462 cxx_incomplete_type_error (r, rtype);
8463 r = error_mark_node;
8467 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
8468 such a thing will already have been added to the field
8469 list by tsubst_enum in finish_member_declaration in the
8470 CLASSTYPE_NESTED_UTDS case above. */
8471 if (!(TREE_CODE (r) == TYPE_DECL
8472 && TREE_CODE (TREE_TYPE (r)) == ENUMERAL_TYPE
8473 && DECL_ARTIFICIAL (r)))
8475 set_current_access_from_decl (r);
8476 finish_member_declaration (r);
8483 if (TYPE_P (t) || DECL_CLASS_TEMPLATE_P (t))
8485 /* Build new CLASSTYPE_FRIEND_CLASSES. */
8487 tree friend_type = t;
8488 bool adjust_processing_template_decl = false;
8490 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
8492 /* template <class T> friend class C; */
8493 friend_type = tsubst_friend_class (friend_type, args);
8494 adjust_processing_template_decl = true;
8496 else if (TREE_CODE (friend_type) == UNBOUND_CLASS_TEMPLATE)
8498 /* template <class T> friend class C::D; */
8499 friend_type = tsubst (friend_type, args,
8500 tf_warning_or_error, NULL_TREE);
8501 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
8502 friend_type = TREE_TYPE (friend_type);
8503 adjust_processing_template_decl = true;
8505 else if (TREE_CODE (friend_type) == TYPENAME_TYPE
8506 || TREE_CODE (friend_type) == TEMPLATE_TYPE_PARM)
8508 /* This could be either
8512 when dependent_type_p is false or
8514 template <class U> friend class T::C;
8517 friend_type = tsubst (friend_type, args,
8518 tf_warning_or_error, NULL_TREE);
8519 /* Bump processing_template_decl for correct
8520 dependent_type_p calculation. */
8521 ++processing_template_decl;
8522 if (dependent_type_p (friend_type))
8523 adjust_processing_template_decl = true;
8524 --processing_template_decl;
8526 else if (!CLASSTYPE_USE_TEMPLATE (friend_type)
8527 && hidden_name_p (TYPE_NAME (friend_type)))
8531 where C hasn't been declared yet. Let's lookup name
8532 from namespace scope directly, bypassing any name that
8533 come from dependent base class. */
8534 tree ns = decl_namespace_context (TYPE_MAIN_DECL (friend_type));
8536 /* The call to xref_tag_from_type does injection for friend
8538 push_nested_namespace (ns);
8540 xref_tag_from_type (friend_type, NULL_TREE,
8541 /*tag_scope=*/ts_current);
8542 pop_nested_namespace (ns);
8544 else if (uses_template_parms (friend_type))
8545 /* friend class C<T>; */
8546 friend_type = tsubst (friend_type, args,
8547 tf_warning_or_error, NULL_TREE);
8552 where C is already declared or
8554 friend class C<int>;
8556 We don't have to do anything in these cases. */
8558 if (adjust_processing_template_decl)
8559 /* Trick make_friend_class into realizing that the friend
8560 we're adding is a template, not an ordinary class. It's
8561 important that we use make_friend_class since it will
8562 perform some error-checking and output cross-reference
8564 ++processing_template_decl;
8566 if (friend_type != error_mark_node)
8567 make_friend_class (type, friend_type, /*complain=*/false);
8569 if (adjust_processing_template_decl)
8570 --processing_template_decl;
8574 /* Build new DECL_FRIENDLIST. */
8577 /* The file and line for this declaration, to
8578 assist in error message reporting. Since we
8579 called push_tinst_level above, we don't need to
8581 input_location = DECL_SOURCE_LOCATION (t);
8583 if (TREE_CODE (t) == TEMPLATE_DECL)
8585 ++processing_template_decl;
8586 push_deferring_access_checks (dk_no_check);
8589 r = tsubst_friend_function (t, args);
8590 add_friend (type, r, /*complain=*/false);
8591 if (TREE_CODE (t) == TEMPLATE_DECL)
8593 pop_deferring_access_checks ();
8594 --processing_template_decl;
8600 if (CLASSTYPE_LAMBDA_EXPR (type))
8601 maybe_add_lambda_conv_op (type);
8603 /* Set the file and line number information to whatever is given for
8604 the class itself. This puts error messages involving generated
8605 implicit functions at a predictable point, and the same point
8606 that would be used for non-template classes. */
8607 input_location = DECL_SOURCE_LOCATION (typedecl);
8609 unreverse_member_declarations (type);
8610 finish_struct_1 (type);
8611 TYPE_BEING_DEFINED (type) = 0;
8613 /* We don't instantiate default arguments for member functions. 14.7.1:
8615 The implicit instantiation of a class template specialization causes
8616 the implicit instantiation of the declarations, but not of the
8617 definitions or default arguments, of the class member functions,
8618 member classes, static data members and member templates.... */
8620 /* Some typedefs referenced from within the template code need to be access
8621 checked at template instantiation time, i.e now. These types were
8622 added to the template at parsing time. Let's get those and perform
8623 the access checks then. */
8624 perform_typedefs_access_check (pattern, args);
8625 perform_deferred_access_checks ();
8626 pop_nested_class ();
8627 maximum_field_alignment = saved_maximum_field_alignment;
8628 pop_from_top_level ();
8629 pop_deferring_access_checks ();
8632 /* The vtable for a template class can be emitted in any translation
8633 unit in which the class is instantiated. When there is no key
8634 method, however, finish_struct_1 will already have added TYPE to
8635 the keyed_classes list. */
8636 if (TYPE_CONTAINS_VPTR_P (type) && CLASSTYPE_KEY_METHOD (type))
8637 keyed_classes = tree_cons (NULL_TREE, type, keyed_classes);
8642 /* Wrapper for instantiate_class_template_1. */
8645 instantiate_class_template (tree type)
8648 timevar_push (TV_TEMPLATE_INST);
8649 ret = instantiate_class_template_1 (type);
8650 timevar_pop (TV_TEMPLATE_INST);
8655 tsubst_template_arg (tree t, tree args, tsubst_flags_t complain, tree in_decl)
8661 else if (TYPE_P (t))
8662 r = tsubst (t, args, complain, in_decl);
8665 if (!(complain & tf_warning))
8666 ++c_inhibit_evaluation_warnings;
8667 r = tsubst_expr (t, args, complain, in_decl,
8668 /*integral_constant_expression_p=*/true);
8669 if (!(complain & tf_warning))
8670 --c_inhibit_evaluation_warnings;
8675 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
8676 NONTYPE_ARGUMENT_PACK. */
8679 make_fnparm_pack (tree spec_parm)
8681 /* Collect all of the extra "packed" parameters into an
8685 tree argpack = make_node (NONTYPE_ARGUMENT_PACK);
8686 tree argtypepack = cxx_make_type (TYPE_ARGUMENT_PACK);
8687 int i, len = list_length (spec_parm);
8689 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
8690 parmvec = make_tree_vec (len);
8691 parmtypevec = make_tree_vec (len);
8692 for (i = 0; i < len; i++, spec_parm = DECL_CHAIN (spec_parm))
8694 TREE_VEC_ELT (parmvec, i) = spec_parm;
8695 TREE_VEC_ELT (parmtypevec, i) = TREE_TYPE (spec_parm);
8698 /* Build the argument packs. */
8699 SET_ARGUMENT_PACK_ARGS (argpack, parmvec);
8700 SET_ARGUMENT_PACK_ARGS (argtypepack, parmtypevec);
8701 TREE_TYPE (argpack) = argtypepack;
8706 /* Substitute ARGS into T, which is an pack expansion
8707 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
8708 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
8709 (if only a partial substitution could be performed) or
8710 ERROR_MARK_NODE if there was an error. */
8712 tsubst_pack_expansion (tree t, tree args, tsubst_flags_t complain,
8716 tree pack, packs = NULL_TREE, unsubstituted_packs = NULL_TREE;
8720 htab_t saved_local_specializations = NULL;
8722 gcc_assert (PACK_EXPANSION_P (t));
8723 pattern = PACK_EXPANSION_PATTERN (t);
8725 /* Determine the argument packs that will instantiate the parameter
8726 packs used in the expansion expression. While we're at it,
8727 compute the number of arguments to be expanded and make sure it
8729 for (pack = PACK_EXPANSION_PARAMETER_PACKS (t); pack;
8730 pack = TREE_CHAIN (pack))
8732 tree parm_pack = TREE_VALUE (pack);
8733 tree arg_pack = NULL_TREE;
8734 tree orig_arg = NULL_TREE;
8736 if (TREE_CODE (parm_pack) == PARM_DECL)
8738 if (!cp_unevaluated_operand)
8739 arg_pack = retrieve_local_specialization (parm_pack);
8742 /* We can't rely on local_specializations for a parameter
8743 name used later in a function declaration (such as in a
8744 late-specified return type). Even if it exists, it might
8745 have the wrong value for a recursive call. Just make a
8746 dummy decl, since it's only used for its type. */
8747 arg_pack = tsubst_decl (parm_pack, args, complain);
8748 if (arg_pack && FUNCTION_PARAMETER_PACK_P (arg_pack))
8749 /* Partial instantiation of the parm_pack, we can't build
8750 up an argument pack yet. */
8751 arg_pack = NULL_TREE;
8753 arg_pack = make_fnparm_pack (arg_pack);
8758 int level, idx, levels;
8759 template_parm_level_and_index (parm_pack, &level, &idx);
8761 levels = TMPL_ARGS_DEPTH (args);
8762 if (level <= levels)
8763 arg_pack = TMPL_ARG (args, level, idx);
8766 orig_arg = arg_pack;
8767 if (arg_pack && TREE_CODE (arg_pack) == ARGUMENT_PACK_SELECT)
8768 arg_pack = ARGUMENT_PACK_SELECT_FROM_PACK (arg_pack);
8770 if (arg_pack && !ARGUMENT_PACK_P (arg_pack))
8771 /* This can only happen if we forget to expand an argument
8772 pack somewhere else. Just return an error, silently. */
8774 result = make_tree_vec (1);
8775 TREE_VEC_ELT (result, 0) = error_mark_node;
8779 /* For clarity in the comments below let's use the
8780 representation 'argument_pack<elements>' to denote an
8781 argument pack and its elements.
8783 In the 'if' block below, we want to detect cases where
8784 ARG_PACK is argument_pack<PARM_PACK...>. I.e, we want to
8785 check if ARG_PACK is an argument pack which sole element is
8786 the expansion of PARM_PACK. That argument pack is typically
8787 created by template_parm_to_arg when passed a parameter
8790 && TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack)) == 1
8791 && PACK_EXPANSION_P (TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0)))
8793 tree expansion = TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0);
8794 tree pattern = PACK_EXPANSION_PATTERN (expansion);
8795 /* So we have an argument_pack<P...>. We want to test if P
8796 is actually PARM_PACK. We will not use cp_tree_equal to
8797 test P and PARM_PACK because during type fixup (by
8798 fixup_template_parm) P can be a pre-fixup version of a
8799 type and PARM_PACK be its post-fixup version.
8800 cp_tree_equal would consider them as different even
8801 though we would want to consider them compatible for our
8802 precise purpose here.
8804 Thus we are going to consider that P and PARM_PACK are
8805 compatible if they have the same DECL. */
8806 if ((/* If ARG_PACK is a type parameter pack named by the
8807 same DECL as parm_pack ... */
8809 && TYPE_P (parm_pack)
8810 && TYPE_NAME (pattern) == TYPE_NAME (parm_pack))
8811 /* ... or if ARG_PACK is a non-type parameter
8812 named by the same DECL as parm_pack ... */
8813 || (TREE_CODE (pattern) == TEMPLATE_PARM_INDEX
8814 && TREE_CODE (parm_pack) == PARM_DECL
8815 && TEMPLATE_PARM_DECL (pattern)
8816 == TEMPLATE_PARM_DECL (DECL_INITIAL (parm_pack))))
8817 && template_parameter_pack_p (pattern))
8818 /* ... then the argument pack that the parameter maps to
8819 is just an expansion of the parameter itself, such as
8820 one would find in the implicit typedef of a class
8821 inside the class itself. Consider this parameter
8822 "unsubstituted", so that we will maintain the outer
8824 arg_pack = NULL_TREE;
8830 TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack));
8832 /* It's all-or-nothing with incomplete argument packs. */
8833 if (incomplete && !ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
8834 return error_mark_node;
8836 if (ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
8841 else if (len != my_len)
8844 /* We got explicit args for some packs but not others;
8845 do nothing now and try again after deduction. */
8847 if (TREE_CODE (t) == TYPE_PACK_EXPANSION)
8848 error ("mismatched argument pack lengths while expanding "
8852 error ("mismatched argument pack lengths while expanding "
8855 return error_mark_node;
8858 /* Keep track of the parameter packs and their corresponding
8860 packs = tree_cons (parm_pack, arg_pack, packs);
8861 TREE_TYPE (packs) = orig_arg;
8864 /* We can't substitute for this parameter pack. */
8865 unsubstituted_packs = tree_cons (TREE_PURPOSE (pack),
8867 unsubstituted_packs);
8870 /* We cannot expand this expansion expression, because we don't have
8871 all of the argument packs we need. Substitute into the pattern
8872 and return a PACK_EXPANSION_*. The caller will need to deal with
8874 if (unsubstituted_packs)
8877 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
8878 new_pat = tsubst_expr (pattern, args, complain, in_decl,
8879 /*integral_constant_expression_p=*/false);
8881 new_pat = tsubst (pattern, args, complain, in_decl);
8882 return make_pack_expansion (new_pat);
8885 /* We could not find any argument packs that work. */
8887 return error_mark_node;
8889 if (cp_unevaluated_operand)
8891 /* We're in a late-specified return type, so create our own local
8892 specializations table; the current table is either NULL or (in the
8893 case of recursive unification) might have bindings that we don't
8894 want to use or alter. */
8895 saved_local_specializations = local_specializations;
8896 local_specializations = htab_create (37,
8897 hash_local_specialization,
8898 eq_local_specializations,
8902 /* For each argument in each argument pack, substitute into the
8904 result = make_tree_vec (len + incomplete);
8905 for (i = 0; i < len + incomplete; ++i)
8907 /* For parameter pack, change the substitution of the parameter
8908 pack to the ith argument in its argument pack, then expand
8910 for (pack = packs; pack; pack = TREE_CHAIN (pack))
8912 tree parm = TREE_PURPOSE (pack);
8914 if (TREE_CODE (parm) == PARM_DECL)
8916 /* Select the Ith argument from the pack. */
8917 tree arg = make_node (ARGUMENT_PACK_SELECT);
8918 ARGUMENT_PACK_SELECT_FROM_PACK (arg) = TREE_VALUE (pack);
8919 ARGUMENT_PACK_SELECT_INDEX (arg) = i;
8921 register_local_specialization (arg, parm);
8927 template_parm_level_and_index (parm, &level, &idx);
8931 /* Select the Ith argument from the pack. */
8932 value = make_node (ARGUMENT_PACK_SELECT);
8933 ARGUMENT_PACK_SELECT_FROM_PACK (value) = TREE_VALUE (pack);
8934 ARGUMENT_PACK_SELECT_INDEX (value) = i;
8937 /* Update the corresponding argument. */
8938 TMPL_ARG (args, level, idx) = value;
8942 /* Substitute into the PATTERN with the altered arguments. */
8943 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
8944 TREE_VEC_ELT (result, i) =
8945 tsubst_expr (pattern, args, complain, in_decl,
8946 /*integral_constant_expression_p=*/false);
8948 TREE_VEC_ELT (result, i) = tsubst (pattern, args, complain, in_decl);
8951 /* When we have incomplete argument packs, the last "expanded"
8952 result is itself a pack expansion, which allows us
8953 to deduce more arguments. */
8954 TREE_VEC_ELT (result, i) =
8955 make_pack_expansion (TREE_VEC_ELT (result, i));
8957 if (TREE_VEC_ELT (result, i) == error_mark_node)
8959 result = error_mark_node;
8964 /* Update ARGS to restore the substitution from parameter packs to
8965 their argument packs. */
8966 for (pack = packs; pack; pack = TREE_CHAIN (pack))
8968 tree parm = TREE_PURPOSE (pack);
8970 if (TREE_CODE (parm) == PARM_DECL)
8971 register_local_specialization (TREE_TYPE (pack), parm);
8975 template_parm_level_and_index (parm, &level, &idx);
8977 /* Update the corresponding argument. */
8978 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
8979 TREE_VEC_ELT (TREE_VEC_ELT (args, level -1 ), idx) =
8982 TREE_VEC_ELT (args, idx) = TREE_TYPE (pack);
8986 if (saved_local_specializations)
8988 htab_delete (local_specializations);
8989 local_specializations = saved_local_specializations;
8995 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
8996 TMPL. We do this using DECL_PARM_INDEX, which should work even with
8997 parameter packs; all parms generated from a function parameter pack will
8998 have the same DECL_PARM_INDEX. */
9001 get_pattern_parm (tree parm, tree tmpl)
9003 tree pattern = DECL_TEMPLATE_RESULT (tmpl);
9006 if (DECL_ARTIFICIAL (parm))
9008 for (patparm = DECL_ARGUMENTS (pattern);
9009 patparm; patparm = DECL_CHAIN (patparm))
9010 if (DECL_ARTIFICIAL (patparm)
9011 && DECL_NAME (parm) == DECL_NAME (patparm))
9016 patparm = FUNCTION_FIRST_USER_PARM (DECL_TEMPLATE_RESULT (tmpl));
9017 patparm = chain_index (DECL_PARM_INDEX (parm)-1, patparm);
9018 gcc_assert (DECL_PARM_INDEX (patparm)
9019 == DECL_PARM_INDEX (parm));
9025 /* Substitute ARGS into the vector or list of template arguments T. */
9028 tsubst_template_args (tree t, tree args, tsubst_flags_t complain, tree in_decl)
9031 int len, need_new = 0, i, expanded_len_adjust = 0, out;
9034 if (t == error_mark_node)
9035 return error_mark_node;
9037 len = TREE_VEC_LENGTH (t);
9038 elts = XALLOCAVEC (tree, len);
9040 for (i = 0; i < len; i++)
9042 tree orig_arg = TREE_VEC_ELT (t, i);
9045 if (TREE_CODE (orig_arg) == TREE_VEC)
9046 new_arg = tsubst_template_args (orig_arg, args, complain, in_decl);
9047 else if (PACK_EXPANSION_P (orig_arg))
9049 /* Substitute into an expansion expression. */
9050 new_arg = tsubst_pack_expansion (orig_arg, args, complain, in_decl);
9052 if (TREE_CODE (new_arg) == TREE_VEC)
9053 /* Add to the expanded length adjustment the number of
9054 expanded arguments. We subtract one from this
9055 measurement, because the argument pack expression
9056 itself is already counted as 1 in
9057 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
9058 the argument pack is empty. */
9059 expanded_len_adjust += TREE_VEC_LENGTH (new_arg) - 1;
9061 else if (ARGUMENT_PACK_P (orig_arg))
9063 /* Substitute into each of the arguments. */
9064 new_arg = TYPE_P (orig_arg)
9065 ? cxx_make_type (TREE_CODE (orig_arg))
9066 : make_node (TREE_CODE (orig_arg));
9068 SET_ARGUMENT_PACK_ARGS (
9070 tsubst_template_args (ARGUMENT_PACK_ARGS (orig_arg),
9071 args, complain, in_decl));
9073 if (ARGUMENT_PACK_ARGS (new_arg) == error_mark_node)
9074 new_arg = error_mark_node;
9076 if (TREE_CODE (new_arg) == NONTYPE_ARGUMENT_PACK) {
9077 TREE_TYPE (new_arg) = tsubst (TREE_TYPE (orig_arg), args,
9079 TREE_CONSTANT (new_arg) = TREE_CONSTANT (orig_arg);
9081 if (TREE_TYPE (new_arg) == error_mark_node)
9082 new_arg = error_mark_node;
9086 new_arg = tsubst_template_arg (orig_arg, args, complain, in_decl);
9088 if (new_arg == error_mark_node)
9089 return error_mark_node;
9092 if (new_arg != orig_arg)
9099 /* Make space for the expanded arguments coming from template
9101 t = make_tree_vec (len + expanded_len_adjust);
9102 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
9103 arguments for a member template.
9104 In that case each TREE_VEC in ORIG_T represents a level of template
9105 arguments, and ORIG_T won't carry any non defaulted argument count.
9106 It will rather be the nested TREE_VECs that will carry one.
9107 In other words, ORIG_T carries a non defaulted argument count only
9108 if it doesn't contain any nested TREE_VEC. */
9109 if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t))
9111 int count = GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t);
9112 count += expanded_len_adjust;
9113 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (t, count);
9115 for (i = 0, out = 0; i < len; i++)
9117 if ((PACK_EXPANSION_P (TREE_VEC_ELT (orig_t, i))
9118 || ARGUMENT_PACK_P (TREE_VEC_ELT (orig_t, i)))
9119 && TREE_CODE (elts[i]) == TREE_VEC)
9123 /* Now expand the template argument pack "in place". */
9124 for (idx = 0; idx < TREE_VEC_LENGTH (elts[i]); idx++, out++)
9125 TREE_VEC_ELT (t, out) = TREE_VEC_ELT (elts[i], idx);
9129 TREE_VEC_ELT (t, out) = elts[i];
9137 /* Return the result of substituting ARGS into the template parameters
9138 given by PARMS. If there are m levels of ARGS and m + n levels of
9139 PARMS, then the result will contain n levels of PARMS. For
9140 example, if PARMS is `template <class T> template <class U>
9141 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
9142 result will be `template <int*, double, class V>'. */
9145 tsubst_template_parms (tree parms, tree args, tsubst_flags_t complain)
9150 /* When substituting into a template, we must set
9151 PROCESSING_TEMPLATE_DECL as the template parameters may be
9152 dependent if they are based on one-another, and the dependency
9153 predicates are short-circuit outside of templates. */
9154 ++processing_template_decl;
9156 for (new_parms = &r;
9157 TMPL_PARMS_DEPTH (parms) > TMPL_ARGS_DEPTH (args);
9158 new_parms = &(TREE_CHAIN (*new_parms)),
9159 parms = TREE_CHAIN (parms))
9162 make_tree_vec (TREE_VEC_LENGTH (TREE_VALUE (parms)));
9165 for (i = 0; i < TREE_VEC_LENGTH (new_vec); ++i)
9169 if (parms == error_mark_node)
9172 tuple = TREE_VEC_ELT (TREE_VALUE (parms), i);
9174 if (tuple == error_mark_node)
9177 TREE_VEC_ELT (new_vec, i) =
9178 tsubst_template_parm (tuple, args, complain);
9182 tree_cons (size_int (TMPL_PARMS_DEPTH (parms)
9183 - TMPL_ARGS_DEPTH (args)),
9184 new_vec, NULL_TREE);
9187 --processing_template_decl;
9192 /* Return the result of substituting ARGS into one template parameter
9193 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
9194 parameter and which TREE_PURPOSE is the default argument of the
9195 template parameter. */
9198 tsubst_template_parm (tree t, tree args, tsubst_flags_t complain)
9200 tree default_value, parm_decl;
9202 if (args == NULL_TREE
9204 || t == error_mark_node)
9207 gcc_assert (TREE_CODE (t) == TREE_LIST);
9209 default_value = TREE_PURPOSE (t);
9210 parm_decl = TREE_VALUE (t);
9212 parm_decl = tsubst (parm_decl, args, complain, NULL_TREE);
9213 if (TREE_CODE (parm_decl) == PARM_DECL
9214 && invalid_nontype_parm_type_p (TREE_TYPE (parm_decl), complain))
9215 parm_decl = error_mark_node;
9216 default_value = tsubst_template_arg (default_value, args,
9217 complain, NULL_TREE);
9219 return build_tree_list (default_value, parm_decl);
9222 /* Substitute the ARGS into the indicated aggregate (or enumeration)
9223 type T. If T is not an aggregate or enumeration type, it is
9224 handled as if by tsubst. IN_DECL is as for tsubst. If
9225 ENTERING_SCOPE is nonzero, T is the context for a template which
9226 we are presently tsubst'ing. Return the substituted value. */
9229 tsubst_aggr_type (tree t,
9231 tsubst_flags_t complain,
9238 switch (TREE_CODE (t))
9241 if (TYPE_PTRMEMFUNC_P (t))
9242 return tsubst (TYPE_PTRMEMFUNC_FN_TYPE (t), args, complain, in_decl);
9244 /* Else fall through. */
9247 if (TYPE_TEMPLATE_INFO (t) && uses_template_parms (t))
9252 int saved_unevaluated_operand;
9253 int saved_inhibit_evaluation_warnings;
9255 /* In "sizeof(X<I>)" we need to evaluate "I". */
9256 saved_unevaluated_operand = cp_unevaluated_operand;
9257 cp_unevaluated_operand = 0;
9258 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
9259 c_inhibit_evaluation_warnings = 0;
9261 /* First, determine the context for the type we are looking
9263 context = TYPE_CONTEXT (t);
9266 context = tsubst_aggr_type (context, args, complain,
9267 in_decl, /*entering_scope=*/1);
9268 /* If context is a nested class inside a class template,
9269 it may still need to be instantiated (c++/33959). */
9270 if (TYPE_P (context))
9271 context = complete_type (context);
9274 /* Then, figure out what arguments are appropriate for the
9275 type we are trying to find. For example, given:
9277 template <class T> struct S;
9278 template <class T, class U> void f(T, U) { S<U> su; }
9280 and supposing that we are instantiating f<int, double>,
9281 then our ARGS will be {int, double}, but, when looking up
9282 S we only want {double}. */
9283 argvec = tsubst_template_args (TYPE_TI_ARGS (t), args,
9285 if (argvec == error_mark_node)
9286 r = error_mark_node;
9289 r = lookup_template_class (t, argvec, in_decl, context,
9290 entering_scope, complain);
9291 r = cp_build_qualified_type_real (r, cp_type_quals (t), complain);
9294 cp_unevaluated_operand = saved_unevaluated_operand;
9295 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
9300 /* This is not a template type, so there's nothing to do. */
9304 return tsubst (t, args, complain, in_decl);
9308 /* Substitute into the default argument ARG (a default argument for
9309 FN), which has the indicated TYPE. */
9312 tsubst_default_argument (tree fn, tree type, tree arg)
9314 tree saved_class_ptr = NULL_TREE;
9315 tree saved_class_ref = NULL_TREE;
9317 /* This can happen in invalid code. */
9318 if (TREE_CODE (arg) == DEFAULT_ARG)
9321 /* This default argument came from a template. Instantiate the
9322 default argument here, not in tsubst. In the case of
9331 we must be careful to do name lookup in the scope of S<T>,
9332 rather than in the current class. */
9333 push_access_scope (fn);
9334 /* The "this" pointer is not valid in a default argument. */
9337 saved_class_ptr = current_class_ptr;
9338 cp_function_chain->x_current_class_ptr = NULL_TREE;
9339 saved_class_ref = current_class_ref;
9340 cp_function_chain->x_current_class_ref = NULL_TREE;
9343 push_deferring_access_checks(dk_no_deferred);
9344 /* The default argument expression may cause implicitly defined
9345 member functions to be synthesized, which will result in garbage
9346 collection. We must treat this situation as if we were within
9347 the body of function so as to avoid collecting live data on the
9350 arg = tsubst_expr (arg, DECL_TI_ARGS (fn),
9351 tf_warning_or_error, NULL_TREE,
9352 /*integral_constant_expression_p=*/false);
9354 pop_deferring_access_checks();
9356 /* Restore the "this" pointer. */
9359 cp_function_chain->x_current_class_ptr = saved_class_ptr;
9360 cp_function_chain->x_current_class_ref = saved_class_ref;
9363 /* Make sure the default argument is reasonable. */
9364 arg = check_default_argument (type, arg);
9366 pop_access_scope (fn);
9371 /* Substitute into all the default arguments for FN. */
9374 tsubst_default_arguments (tree fn)
9379 tmpl_args = DECL_TI_ARGS (fn);
9381 /* If this function is not yet instantiated, we certainly don't need
9382 its default arguments. */
9383 if (uses_template_parms (tmpl_args))
9385 /* Don't do this again for clones. */
9386 if (DECL_CLONED_FUNCTION_P (fn))
9389 for (arg = TYPE_ARG_TYPES (TREE_TYPE (fn));
9391 arg = TREE_CHAIN (arg))
9392 if (TREE_PURPOSE (arg))
9393 TREE_PURPOSE (arg) = tsubst_default_argument (fn,
9395 TREE_PURPOSE (arg));
9398 /* Substitute the ARGS into the T, which is a _DECL. Return the
9399 result of the substitution. Issue error and warning messages under
9400 control of COMPLAIN. */
9403 tsubst_decl (tree t, tree args, tsubst_flags_t complain)
9405 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
9406 location_t saved_loc;
9411 /* Set the filename and linenumber to improve error-reporting. */
9412 saved_loc = input_location;
9413 input_location = DECL_SOURCE_LOCATION (t);
9415 switch (TREE_CODE (t))
9419 /* We can get here when processing a member function template,
9420 member class template, or template template parameter. */
9421 tree decl = DECL_TEMPLATE_RESULT (t);
9426 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
9428 /* Template template parameter is treated here. */
9429 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9430 if (new_type == error_mark_node)
9431 RETURN (error_mark_node);
9434 DECL_CHAIN (r) = NULL_TREE;
9435 TREE_TYPE (r) = new_type;
9436 DECL_TEMPLATE_RESULT (r)
9437 = build_decl (DECL_SOURCE_LOCATION (decl),
9438 TYPE_DECL, DECL_NAME (decl), new_type);
9439 DECL_TEMPLATE_PARMS (r)
9440 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
9442 TYPE_NAME (new_type) = r;
9446 /* We might already have an instance of this template.
9447 The ARGS are for the surrounding class type, so the
9448 full args contain the tsubst'd args for the context,
9449 plus the innermost args from the template decl. */
9450 tmpl_args = DECL_CLASS_TEMPLATE_P (t)
9451 ? CLASSTYPE_TI_ARGS (TREE_TYPE (t))
9452 : DECL_TI_ARGS (DECL_TEMPLATE_RESULT (t));
9453 /* Because this is a template, the arguments will still be
9454 dependent, even after substitution. If
9455 PROCESSING_TEMPLATE_DECL is not set, the dependency
9456 predicates will short-circuit. */
9457 ++processing_template_decl;
9458 full_args = tsubst_template_args (tmpl_args, args,
9460 --processing_template_decl;
9461 if (full_args == error_mark_node)
9462 RETURN (error_mark_node);
9464 /* If this is a default template template argument,
9465 tsubst might not have changed anything. */
9466 if (full_args == tmpl_args)
9469 hash = hash_tmpl_and_args (t, full_args);
9470 spec = retrieve_specialization (t, full_args, hash);
9471 if (spec != NULL_TREE)
9477 /* Make a new template decl. It will be similar to the
9478 original, but will record the current template arguments.
9479 We also create a new function declaration, which is just
9480 like the old one, but points to this new template, rather
9481 than the old one. */
9483 gcc_assert (DECL_LANG_SPECIFIC (r) != 0);
9484 DECL_CHAIN (r) = NULL_TREE;
9486 DECL_TEMPLATE_INFO (r) = build_template_info (t, args);
9488 if (TREE_CODE (decl) == TYPE_DECL)
9491 ++processing_template_decl;
9492 new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9493 --processing_template_decl;
9494 if (new_type == error_mark_node)
9495 RETURN (error_mark_node);
9497 TREE_TYPE (r) = new_type;
9498 CLASSTYPE_TI_TEMPLATE (new_type) = r;
9499 DECL_TEMPLATE_RESULT (r) = TYPE_MAIN_DECL (new_type);
9500 DECL_TI_ARGS (r) = CLASSTYPE_TI_ARGS (new_type);
9501 DECL_CONTEXT (r) = TYPE_CONTEXT (new_type);
9506 ++processing_template_decl;
9507 new_decl = tsubst (decl, args, complain, in_decl);
9508 --processing_template_decl;
9509 if (new_decl == error_mark_node)
9510 RETURN (error_mark_node);
9512 DECL_TEMPLATE_RESULT (r) = new_decl;
9513 DECL_TI_TEMPLATE (new_decl) = r;
9514 TREE_TYPE (r) = TREE_TYPE (new_decl);
9515 DECL_TI_ARGS (r) = DECL_TI_ARGS (new_decl);
9516 DECL_CONTEXT (r) = DECL_CONTEXT (new_decl);
9519 SET_DECL_IMPLICIT_INSTANTIATION (r);
9520 DECL_TEMPLATE_INSTANTIATIONS (r) = NULL_TREE;
9521 DECL_TEMPLATE_SPECIALIZATIONS (r) = NULL_TREE;
9523 /* The template parameters for this new template are all the
9524 template parameters for the old template, except the
9525 outermost level of parameters. */
9526 DECL_TEMPLATE_PARMS (r)
9527 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
9530 if (PRIMARY_TEMPLATE_P (t))
9531 DECL_PRIMARY_TEMPLATE (r) = r;
9533 if (TREE_CODE (decl) != TYPE_DECL)
9534 /* Record this non-type partial instantiation. */
9535 register_specialization (r, t,
9536 DECL_TI_ARGS (DECL_TEMPLATE_RESULT (r)),
9544 tree argvec = NULL_TREE;
9552 /* Nobody should be tsubst'ing into non-template functions. */
9553 gcc_assert (DECL_TEMPLATE_INFO (t) != NULL_TREE);
9555 if (TREE_CODE (DECL_TI_TEMPLATE (t)) == TEMPLATE_DECL)
9560 /* If T is not dependent, just return it. We have to
9561 increment PROCESSING_TEMPLATE_DECL because
9562 value_dependent_expression_p assumes that nothing is
9563 dependent when PROCESSING_TEMPLATE_DECL is zero. */
9564 ++processing_template_decl;
9565 dependent_p = value_dependent_expression_p (t);
9566 --processing_template_decl;
9570 /* Calculate the most general template of which R is a
9571 specialization, and the complete set of arguments used to
9573 gen_tmpl = most_general_template (DECL_TI_TEMPLATE (t));
9574 argvec = tsubst_template_args (DECL_TI_ARGS
9575 (DECL_TEMPLATE_RESULT
9576 (DECL_TI_TEMPLATE (t))),
9577 args, complain, in_decl);
9578 if (argvec == error_mark_node)
9579 RETURN (error_mark_node);
9581 /* Check to see if we already have this specialization. */
9582 hash = hash_tmpl_and_args (gen_tmpl, argvec);
9583 spec = retrieve_specialization (gen_tmpl, argvec, hash);
9591 /* We can see more levels of arguments than parameters if
9592 there was a specialization of a member template, like
9595 template <class T> struct S { template <class U> void f(); }
9596 template <> template <class U> void S<int>::f(U);
9598 Here, we'll be substituting into the specialization,
9599 because that's where we can find the code we actually
9600 want to generate, but we'll have enough arguments for
9601 the most general template.
9603 We also deal with the peculiar case:
9605 template <class T> struct S {
9606 template <class U> friend void f();
9608 template <class U> void f() {}
9610 template void f<double>();
9612 Here, the ARGS for the instantiation of will be {int,
9613 double}. But, we only need as many ARGS as there are
9614 levels of template parameters in CODE_PATTERN. We are
9615 careful not to get fooled into reducing the ARGS in
9618 template <class T> struct S { template <class U> void f(U); }
9619 template <class T> template <> void S<T>::f(int) {}
9621 which we can spot because the pattern will be a
9622 specialization in this case. */
9623 args_depth = TMPL_ARGS_DEPTH (args);
9625 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (t)));
9626 if (args_depth > parms_depth
9627 && !DECL_TEMPLATE_SPECIALIZATION (t))
9628 args = get_innermost_template_args (args, parms_depth);
9632 /* This special case arises when we have something like this:
9634 template <class T> struct S {
9635 friend void f<int>(int, double);
9638 Here, the DECL_TI_TEMPLATE for the friend declaration
9639 will be an IDENTIFIER_NODE. We are being called from
9640 tsubst_friend_function, and we want only to create a
9641 new decl (R) with appropriate types so that we can call
9642 determine_specialization. */
9643 gen_tmpl = NULL_TREE;
9646 if (DECL_CLASS_SCOPE_P (t))
9648 if (DECL_NAME (t) == constructor_name (DECL_CONTEXT (t)))
9652 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args,
9653 complain, t, /*entering_scope=*/1);
9658 ctx = DECL_CONTEXT (t);
9660 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9661 if (type == error_mark_node)
9662 RETURN (error_mark_node);
9664 /* We do NOT check for matching decls pushed separately at this
9665 point, as they may not represent instantiations of this
9666 template, and in any case are considered separate under the
9669 DECL_USE_TEMPLATE (r) = 0;
9670 TREE_TYPE (r) = type;
9671 /* Clear out the mangled name and RTL for the instantiation. */
9672 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
9673 SET_DECL_RTL (r, NULL);
9674 /* Leave DECL_INITIAL set on deleted instantiations. */
9675 if (!DECL_DELETED_FN (r))
9676 DECL_INITIAL (r) = NULL_TREE;
9677 DECL_CONTEXT (r) = ctx;
9679 if (member && DECL_CONV_FN_P (r))
9680 /* Type-conversion operator. Reconstruct the name, in
9681 case it's the name of one of the template's parameters. */
9682 DECL_NAME (r) = mangle_conv_op_name_for_type (TREE_TYPE (type));
9684 DECL_ARGUMENTS (r) = tsubst (DECL_ARGUMENTS (t), args,
9686 DECL_RESULT (r) = NULL_TREE;
9688 TREE_STATIC (r) = 0;
9689 TREE_PUBLIC (r) = TREE_PUBLIC (t);
9690 DECL_EXTERNAL (r) = 1;
9691 /* If this is an instantiation of a function with internal
9692 linkage, we already know what object file linkage will be
9693 assigned to the instantiation. */
9694 DECL_INTERFACE_KNOWN (r) = !TREE_PUBLIC (r);
9695 DECL_DEFER_OUTPUT (r) = 0;
9696 DECL_CHAIN (r) = NULL_TREE;
9697 DECL_PENDING_INLINE_INFO (r) = 0;
9698 DECL_PENDING_INLINE_P (r) = 0;
9699 DECL_SAVED_TREE (r) = NULL_TREE;
9700 DECL_STRUCT_FUNCTION (r) = NULL;
9702 /* We'll re-clone as appropriate in instantiate_template. */
9703 DECL_CLONED_FUNCTION (r) = NULL_TREE;
9705 /* If we aren't complaining now, return on error before we register
9706 the specialization so that we'll complain eventually. */
9707 if ((complain & tf_error) == 0
9708 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
9709 && !grok_op_properties (r, /*complain=*/false))
9710 RETURN (error_mark_node);
9712 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
9713 this in the special friend case mentioned above where
9714 GEN_TMPL is NULL. */
9717 DECL_TEMPLATE_INFO (r)
9718 = build_template_info (gen_tmpl, argvec);
9719 SET_DECL_IMPLICIT_INSTANTIATION (r);
9720 register_specialization (r, gen_tmpl, argvec, false, hash);
9722 /* We're not supposed to instantiate default arguments
9723 until they are called, for a template. But, for a
9726 template <class T> void f ()
9727 { extern void g(int i = T()); }
9729 we should do the substitution when the template is
9730 instantiated. We handle the member function case in
9731 instantiate_class_template since the default arguments
9732 might refer to other members of the class. */
9734 && !PRIMARY_TEMPLATE_P (gen_tmpl)
9735 && !uses_template_parms (argvec))
9736 tsubst_default_arguments (r);
9739 DECL_TEMPLATE_INFO (r) = NULL_TREE;
9741 /* Copy the list of befriending classes. */
9742 for (friends = &DECL_BEFRIENDING_CLASSES (r);
9744 friends = &TREE_CHAIN (*friends))
9746 *friends = copy_node (*friends);
9747 TREE_VALUE (*friends) = tsubst (TREE_VALUE (*friends),
9752 if (DECL_CONSTRUCTOR_P (r) || DECL_DESTRUCTOR_P (r))
9754 maybe_retrofit_in_chrg (r);
9755 if (DECL_CONSTRUCTOR_P (r))
9756 grok_ctor_properties (ctx, r);
9757 /* If this is an instantiation of a member template, clone it.
9758 If it isn't, that'll be handled by
9759 clone_constructors_and_destructors. */
9760 if (PRIMARY_TEMPLATE_P (gen_tmpl))
9761 clone_function_decl (r, /*update_method_vec_p=*/0);
9763 else if ((complain & tf_error) != 0
9764 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
9765 && !grok_op_properties (r, /*complain=*/true))
9766 RETURN (error_mark_node);
9768 if (DECL_FRIEND_P (t) && DECL_FRIEND_CONTEXT (t))
9769 SET_DECL_FRIEND_CONTEXT (r,
9770 tsubst (DECL_FRIEND_CONTEXT (t),
9771 args, complain, in_decl));
9773 /* Possibly limit visibility based on template args. */
9774 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
9775 if (DECL_VISIBILITY_SPECIFIED (t))
9777 DECL_VISIBILITY_SPECIFIED (r) = 0;
9779 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
9781 determine_visibility (r);
9782 if (DECL_DEFAULTED_OUTSIDE_CLASS_P (r)
9783 && !processing_template_decl)
9784 defaulted_late_check (r);
9786 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
9787 args, complain, in_decl);
9793 tree type = NULL_TREE;
9795 tree expanded_types = NULL_TREE;
9796 tree prev_r = NULL_TREE;
9797 tree first_r = NULL_TREE;
9799 if (FUNCTION_PARAMETER_PACK_P (t))
9801 /* If there is a local specialization that isn't a
9802 parameter pack, it means that we're doing a "simple"
9803 substitution from inside tsubst_pack_expansion. Just
9804 return the local specialization (which will be a single
9806 tree spec = retrieve_local_specialization (t);
9808 && TREE_CODE (spec) == PARM_DECL
9809 && TREE_CODE (TREE_TYPE (spec)) != TYPE_PACK_EXPANSION)
9812 /* Expand the TYPE_PACK_EXPANSION that provides the types for
9813 the parameters in this function parameter pack. */
9814 expanded_types = tsubst_pack_expansion (TREE_TYPE (t), args,
9816 if (TREE_CODE (expanded_types) == TREE_VEC)
9818 len = TREE_VEC_LENGTH (expanded_types);
9820 /* Zero-length parameter packs are boring. Just substitute
9823 RETURN (tsubst (TREE_CHAIN (t), args, complain,
9828 /* All we did was update the type. Make a note of that. */
9829 type = expanded_types;
9830 expanded_types = NULL_TREE;
9834 /* Loop through all of the parameter's we'll build. When T is
9835 a function parameter pack, LEN is the number of expanded
9836 types in EXPANDED_TYPES; otherwise, LEN is 1. */
9838 for (i = 0; i < len; ++i)
9842 if (DECL_TEMPLATE_PARM_P (t))
9843 SET_DECL_TEMPLATE_PARM_P (r);
9846 /* We're on the Ith parameter of the function parameter
9849 /* An argument of a function parameter pack is not a parameter
9851 FUNCTION_PARAMETER_PACK_P (r) = false;
9853 /* Get the Ith type. */
9854 type = TREE_VEC_ELT (expanded_types, i);
9857 /* Rename the parameter to include the index. */
9859 make_ith_pack_parameter_name (DECL_NAME (r), i);
9862 /* We're dealing with a normal parameter. */
9863 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9865 type = type_decays_to (type);
9866 TREE_TYPE (r) = type;
9867 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
9869 if (DECL_INITIAL (r))
9871 if (TREE_CODE (DECL_INITIAL (r)) != TEMPLATE_PARM_INDEX)
9872 DECL_INITIAL (r) = TREE_TYPE (r);
9874 DECL_INITIAL (r) = tsubst (DECL_INITIAL (r), args,
9878 DECL_CONTEXT (r) = NULL_TREE;
9880 if (!DECL_TEMPLATE_PARM_P (r))
9881 DECL_ARG_TYPE (r) = type_passed_as (type);
9883 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
9884 args, complain, in_decl);
9886 /* Keep track of the first new parameter we
9887 generate. That's what will be returned to the
9892 /* Build a proper chain of parameters when substituting
9893 into a function parameter pack. */
9895 DECL_CHAIN (prev_r) = r;
9899 DECL_CHAIN (r) = tsubst (DECL_CHAIN (t), args,
9900 complain, DECL_CHAIN (t));
9902 /* FIRST_R contains the start of the chain we've built. */
9912 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9913 if (type == error_mark_node)
9914 RETURN (error_mark_node);
9915 TREE_TYPE (r) = type;
9916 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
9918 /* DECL_INITIAL gives the number of bits in a bit-field. */
9920 = tsubst_expr (DECL_INITIAL (t), args,
9922 /*integral_constant_expression_p=*/true);
9923 /* We don't have to set DECL_CONTEXT here; it is set by
9924 finish_member_declaration. */
9925 DECL_CHAIN (r) = NULL_TREE;
9926 if (VOID_TYPE_P (type))
9927 error ("instantiation of %q+D as type %qT", r, type);
9929 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
9930 args, complain, in_decl);
9935 /* We reach here only for member using decls. */
9936 if (DECL_DEPENDENT_P (t))
9938 r = do_class_using_decl
9939 (tsubst_copy (USING_DECL_SCOPE (t), args, complain, in_decl),
9940 tsubst_copy (DECL_NAME (t), args, complain, in_decl));
9942 r = error_mark_node;
9945 TREE_PROTECTED (r) = TREE_PROTECTED (t);
9946 TREE_PRIVATE (r) = TREE_PRIVATE (t);
9952 DECL_CHAIN (r) = NULL_TREE;
9959 tree argvec = NULL_TREE;
9960 tree gen_tmpl = NULL_TREE;
9962 tree tmpl = NULL_TREE;
9964 tree type = NULL_TREE;
9967 if (TREE_CODE (t) == TYPE_DECL
9968 && t == TYPE_MAIN_DECL (TREE_TYPE (t)))
9970 /* If this is the canonical decl, we don't have to
9971 mess with instantiations, and often we can't (for
9972 typename, template type parms and such). Note that
9973 TYPE_NAME is not correct for the above test if
9974 we've copied the type for a typedef. */
9975 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9976 if (type == error_mark_node)
9977 RETURN (error_mark_node);
9978 r = TYPE_NAME (type);
9982 /* Check to see if we already have the specialization we
9985 if (DECL_CLASS_SCOPE_P (t) || DECL_NAMESPACE_SCOPE_P (t))
9987 /* T is a static data member or namespace-scope entity.
9988 We have to substitute into namespace-scope variables
9989 (even though such entities are never templates) because
9992 template <class T> void f() { extern T t; }
9994 where the entity referenced is not known until
9995 instantiation time. */
9997 ctx = DECL_CONTEXT (t);
9998 if (DECL_CLASS_SCOPE_P (t))
10000 ctx = tsubst_aggr_type (ctx, args,
10002 in_decl, /*entering_scope=*/1);
10003 /* If CTX is unchanged, then T is in fact the
10004 specialization we want. That situation occurs when
10005 referencing a static data member within in its own
10006 class. We can use pointer equality, rather than
10007 same_type_p, because DECL_CONTEXT is always
10009 if (ctx == DECL_CONTEXT (t))
10015 tmpl = DECL_TI_TEMPLATE (t);
10016 gen_tmpl = most_general_template (tmpl);
10017 argvec = tsubst (DECL_TI_ARGS (t), args, complain, in_decl);
10018 hash = hash_tmpl_and_args (gen_tmpl, argvec);
10019 spec = retrieve_specialization (gen_tmpl, argvec, hash);
10024 /* A local variable. */
10026 /* Subsequent calls to pushdecl will fill this in. */
10028 spec = retrieve_local_specialization (t);
10030 /* If we already have the specialization we need, there is
10031 nothing more to do. */
10038 /* Create a new node for the specialization we need. */
10040 if (type == NULL_TREE)
10042 if (is_typedef_decl (t))
10043 type = DECL_ORIGINAL_TYPE (t);
10045 type = TREE_TYPE (t);
10046 if (TREE_CODE (t) == VAR_DECL && VAR_HAD_UNKNOWN_BOUND (t))
10047 type = strip_array_domain (type);
10048 type = tsubst (type, args, complain, in_decl);
10050 if (TREE_CODE (r) == VAR_DECL)
10052 /* Even if the original location is out of scope, the
10053 newly substituted one is not. */
10054 DECL_DEAD_FOR_LOCAL (r) = 0;
10055 DECL_INITIALIZED_P (r) = 0;
10056 DECL_TEMPLATE_INSTANTIATED (r) = 0;
10057 if (type == error_mark_node)
10058 RETURN (error_mark_node);
10059 if (TREE_CODE (type) == FUNCTION_TYPE)
10061 /* It may seem that this case cannot occur, since:
10066 declares a function, not a variable. However:
10069 template <typename T> void g() { T t; }
10070 template void g<f>();
10072 is an attempt to declare a variable with function
10074 error ("variable %qD has function type",
10075 /* R is not yet sufficiently initialized, so we
10076 just use its name. */
10078 RETURN (error_mark_node);
10080 type = complete_type (type);
10081 /* Wait until cp_finish_decl to set this again, to handle
10082 circular dependency (template/instantiate6.C). */
10083 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r) = 0;
10084 type = check_var_type (DECL_NAME (r), type);
10086 if (DECL_HAS_VALUE_EXPR_P (t))
10088 tree ve = DECL_VALUE_EXPR (t);
10089 ve = tsubst_expr (ve, args, complain, in_decl,
10090 /*constant_expression_p=*/false);
10091 if (REFERENCE_REF_P (ve))
10093 gcc_assert (TREE_CODE (type) == REFERENCE_TYPE);
10094 ve = TREE_OPERAND (ve, 0);
10096 SET_DECL_VALUE_EXPR (r, ve);
10099 else if (DECL_SELF_REFERENCE_P (t))
10100 SET_DECL_SELF_REFERENCE_P (r);
10101 TREE_TYPE (r) = type;
10102 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
10103 DECL_CONTEXT (r) = ctx;
10104 /* Clear out the mangled name and RTL for the instantiation. */
10105 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
10106 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
10107 SET_DECL_RTL (r, NULL);
10108 /* The initializer must not be expanded until it is required;
10109 see [temp.inst]. */
10110 DECL_INITIAL (r) = NULL_TREE;
10111 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
10112 SET_DECL_RTL (r, NULL);
10113 DECL_SIZE (r) = DECL_SIZE_UNIT (r) = 0;
10114 if (TREE_CODE (r) == VAR_DECL)
10116 /* Possibly limit visibility based on template args. */
10117 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
10118 if (DECL_VISIBILITY_SPECIFIED (t))
10120 DECL_VISIBILITY_SPECIFIED (r) = 0;
10121 DECL_ATTRIBUTES (r)
10122 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
10124 determine_visibility (r);
10129 /* A static data member declaration is always marked
10130 external when it is declared in-class, even if an
10131 initializer is present. We mimic the non-template
10132 processing here. */
10133 DECL_EXTERNAL (r) = 1;
10135 register_specialization (r, gen_tmpl, argvec, false, hash);
10136 DECL_TEMPLATE_INFO (r) = build_template_info (tmpl, argvec);
10137 SET_DECL_IMPLICIT_INSTANTIATION (r);
10139 else if (cp_unevaluated_operand)
10141 /* We're substituting this var in a decltype outside of its
10142 scope, such as for a lambda return type. Don't add it to
10143 local_specializations, do perform auto deduction. */
10144 tree auto_node = type_uses_auto (type);
10148 = tsubst_expr (DECL_INITIAL (t), args, complain, in_decl,
10149 /*constant_expression_p=*/false);
10150 init = resolve_nondeduced_context (init);
10151 TREE_TYPE (r) = type
10152 = do_auto_deduction (type, init, auto_node);
10156 register_local_specialization (r, t);
10158 DECL_CHAIN (r) = NULL_TREE;
10160 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r),
10162 args, complain, in_decl);
10164 /* Preserve a typedef that names a type. */
10165 if (is_typedef_decl (r))
10167 DECL_ORIGINAL_TYPE (r) = NULL_TREE;
10168 set_underlying_type (r);
10171 layout_decl (r, 0);
10176 gcc_unreachable ();
10181 /* Restore the file and line information. */
10182 input_location = saved_loc;
10187 /* Substitute into the ARG_TYPES of a function type. */
10190 tsubst_arg_types (tree arg_types,
10192 tsubst_flags_t complain,
10195 tree remaining_arg_types;
10196 tree type = NULL_TREE;
10198 tree expanded_args = NULL_TREE;
10201 if (!arg_types || arg_types == void_list_node)
10204 remaining_arg_types = tsubst_arg_types (TREE_CHAIN (arg_types),
10205 args, complain, in_decl);
10206 if (remaining_arg_types == error_mark_node)
10207 return error_mark_node;
10209 if (PACK_EXPANSION_P (TREE_VALUE (arg_types)))
10211 /* For a pack expansion, perform substitution on the
10212 entire expression. Later on, we'll handle the arguments
10214 expanded_args = tsubst_pack_expansion (TREE_VALUE (arg_types),
10215 args, complain, in_decl);
10217 if (TREE_CODE (expanded_args) == TREE_VEC)
10218 /* So that we'll spin through the parameters, one by one. */
10219 i = TREE_VEC_LENGTH (expanded_args);
10222 /* We only partially substituted into the parameter
10223 pack. Our type is TYPE_PACK_EXPANSION. */
10224 type = expanded_args;
10225 expanded_args = NULL_TREE;
10233 type = TREE_VEC_ELT (expanded_args, i);
10235 type = tsubst (TREE_VALUE (arg_types), args, complain, in_decl);
10237 if (type == error_mark_node)
10238 return error_mark_node;
10239 if (VOID_TYPE_P (type))
10241 if (complain & tf_error)
10243 error ("invalid parameter type %qT", type);
10245 error ("in declaration %q+D", in_decl);
10247 return error_mark_node;
10250 /* Do array-to-pointer, function-to-pointer conversion, and ignore
10251 top-level qualifiers as required. */
10252 type = cv_unqualified (type_decays_to (type));
10254 /* We do not substitute into default arguments here. The standard
10255 mandates that they be instantiated only when needed, which is
10256 done in build_over_call. */
10257 default_arg = TREE_PURPOSE (arg_types);
10259 if (default_arg && TREE_CODE (default_arg) == DEFAULT_ARG)
10261 /* We've instantiated a template before its default arguments
10262 have been parsed. This can happen for a nested template
10263 class, and is not an error unless we require the default
10264 argument in a call of this function. */
10265 remaining_arg_types =
10266 tree_cons (default_arg, type, remaining_arg_types);
10267 VEC_safe_push (tree, gc, DEFARG_INSTANTIATIONS (default_arg),
10268 remaining_arg_types);
10271 remaining_arg_types =
10272 hash_tree_cons (default_arg, type, remaining_arg_types);
10275 return remaining_arg_types;
10278 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
10279 *not* handle the exception-specification for FNTYPE, because the
10280 initial substitution of explicitly provided template parameters
10281 during argument deduction forbids substitution into the
10282 exception-specification:
10286 All references in the function type of the function template to the
10287 corresponding template parameters are replaced by the specified tem-
10288 plate argument values. If a substitution in a template parameter or
10289 in the function type of the function template results in an invalid
10290 type, type deduction fails. [Note: The equivalent substitution in
10291 exception specifications is done only when the function is instanti-
10292 ated, at which point a program is ill-formed if the substitution
10293 results in an invalid type.] */
10296 tsubst_function_type (tree t,
10298 tsubst_flags_t complain,
10305 /* The TYPE_CONTEXT is not used for function/method types. */
10306 gcc_assert (TYPE_CONTEXT (t) == NULL_TREE);
10308 /* Substitute the return type. */
10309 return_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10310 if (return_type == error_mark_node)
10311 return error_mark_node;
10312 /* The standard does not presently indicate that creation of a
10313 function type with an invalid return type is a deduction failure.
10314 However, that is clearly analogous to creating an array of "void"
10315 or a reference to a reference. This is core issue #486. */
10316 if (TREE_CODE (return_type) == ARRAY_TYPE
10317 || TREE_CODE (return_type) == FUNCTION_TYPE)
10319 if (complain & tf_error)
10321 if (TREE_CODE (return_type) == ARRAY_TYPE)
10322 error ("function returning an array");
10324 error ("function returning a function");
10326 return error_mark_node;
10329 /* Substitute the argument types. */
10330 arg_types = tsubst_arg_types (TYPE_ARG_TYPES (t), args,
10331 complain, in_decl);
10332 if (arg_types == error_mark_node)
10333 return error_mark_node;
10335 /* Construct a new type node and return it. */
10336 if (TREE_CODE (t) == FUNCTION_TYPE)
10338 fntype = build_function_type (return_type, arg_types);
10339 fntype = apply_memfn_quals (fntype, type_memfn_quals (t));
10343 tree r = TREE_TYPE (TREE_VALUE (arg_types));
10344 if (! MAYBE_CLASS_TYPE_P (r))
10348 Type deduction may fail for any of the following
10351 -- Attempting to create "pointer to member of T" when T
10352 is not a class type. */
10353 if (complain & tf_error)
10354 error ("creating pointer to member function of non-class type %qT",
10356 return error_mark_node;
10359 fntype = build_method_type_directly (r, return_type,
10360 TREE_CHAIN (arg_types));
10362 fntype = cp_build_type_attribute_variant (fntype, TYPE_ATTRIBUTES (t));
10367 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
10368 ARGS into that specification, and return the substituted
10369 specification. If there is no specification, return NULL_TREE. */
10372 tsubst_exception_specification (tree fntype,
10374 tsubst_flags_t complain,
10381 specs = TYPE_RAISES_EXCEPTIONS (fntype);
10382 new_specs = NULL_TREE;
10383 if (specs && TREE_PURPOSE (specs))
10385 /* A noexcept-specifier. */
10386 tree expr = TREE_PURPOSE (specs);
10387 if (expr == boolean_true_node || expr == boolean_false_node)
10391 /* Defer instantiation of noexcept-specifiers to avoid
10392 excessive instantiations (c++/49107). */
10393 new_specs = make_node (DEFERRED_NOEXCEPT);
10394 if (DEFERRED_NOEXCEPT_SPEC_P (specs))
10396 /* We already partially instantiated this member template,
10397 so combine the new args with the old. */
10398 DEFERRED_NOEXCEPT_PATTERN (new_specs)
10399 = DEFERRED_NOEXCEPT_PATTERN (expr);
10400 DEFERRED_NOEXCEPT_ARGS (new_specs)
10401 = add_to_template_args (DEFERRED_NOEXCEPT_ARGS (expr), args);
10405 DEFERRED_NOEXCEPT_PATTERN (new_specs) = expr;
10406 DEFERRED_NOEXCEPT_ARGS (new_specs) = args;
10410 new_specs = tsubst_copy_and_build
10411 (expr, args, complain, in_decl, /*function_p=*/false,
10412 /*integral_constant_expression_p=*/true);
10413 new_specs = build_noexcept_spec (new_specs, complain);
10417 if (! TREE_VALUE (specs))
10424 tree expanded_specs = NULL_TREE;
10426 if (PACK_EXPANSION_P (TREE_VALUE (specs)))
10428 /* Expand the pack expansion type. */
10429 expanded_specs = tsubst_pack_expansion (TREE_VALUE (specs),
10433 if (expanded_specs == error_mark_node)
10434 return error_mark_node;
10435 else if (TREE_CODE (expanded_specs) == TREE_VEC)
10436 len = TREE_VEC_LENGTH (expanded_specs);
10439 /* We're substituting into a member template, so
10440 we got a TYPE_PACK_EXPANSION back. Add that
10441 expansion and move on. */
10442 gcc_assert (TREE_CODE (expanded_specs)
10443 == TYPE_PACK_EXPANSION);
10444 new_specs = add_exception_specifier (new_specs,
10447 specs = TREE_CHAIN (specs);
10452 for (i = 0; i < len; ++i)
10454 if (expanded_specs)
10455 spec = TREE_VEC_ELT (expanded_specs, i);
10457 spec = tsubst (TREE_VALUE (specs), args, complain, in_decl);
10458 if (spec == error_mark_node)
10460 new_specs = add_exception_specifier (new_specs, spec,
10464 specs = TREE_CHAIN (specs);
10470 /* Take the tree structure T and replace template parameters used
10471 therein with the argument vector ARGS. IN_DECL is an associated
10472 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
10473 Issue error and warning messages under control of COMPLAIN. Note
10474 that we must be relatively non-tolerant of extensions here, in
10475 order to preserve conformance; if we allow substitutions that
10476 should not be allowed, we may allow argument deductions that should
10477 not succeed, and therefore report ambiguous overload situations
10478 where there are none. In theory, we could allow the substitution,
10479 but indicate that it should have failed, and allow our caller to
10480 make sure that the right thing happens, but we don't try to do this
10483 This function is used for dealing with types, decls and the like;
10484 for expressions, use tsubst_expr or tsubst_copy. */
10487 tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl)
10489 enum tree_code code;
10492 if (t == NULL_TREE || t == error_mark_node
10493 || t == integer_type_node
10494 || t == void_type_node
10495 || t == char_type_node
10496 || t == unknown_type_node
10497 || TREE_CODE (t) == NAMESPACE_DECL
10498 || TREE_CODE (t) == TRANSLATION_UNIT_DECL)
10502 return tsubst_decl (t, args, complain);
10504 if (args == NULL_TREE)
10507 code = TREE_CODE (t);
10509 if (code == IDENTIFIER_NODE)
10510 type = IDENTIFIER_TYPE_VALUE (t);
10512 type = TREE_TYPE (t);
10514 gcc_assert (type != unknown_type_node);
10516 /* Reuse typedefs. We need to do this to handle dependent attributes,
10517 such as attribute aligned. */
10519 && typedef_variant_p (t))
10521 tree decl = TYPE_NAME (t);
10523 if (DECL_CLASS_SCOPE_P (decl)
10524 && CLASSTYPE_TEMPLATE_INFO (DECL_CONTEXT (decl))
10525 && uses_template_parms (DECL_CONTEXT (decl)))
10527 tree tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
10528 tree gen_args = tsubst (DECL_TI_ARGS (decl), args, complain, in_decl);
10529 r = retrieve_specialization (tmpl, gen_args, 0);
10531 else if (DECL_FUNCTION_SCOPE_P (decl)
10532 && DECL_TEMPLATE_INFO (DECL_CONTEXT (decl))
10533 && uses_template_parms (DECL_TI_ARGS (DECL_CONTEXT (decl))))
10534 r = retrieve_local_specialization (decl);
10536 /* The typedef is from a non-template context. */
10542 r = cp_build_qualified_type_real
10543 (r, cp_type_quals (t) | cp_type_quals (r),
10544 complain | tf_ignore_bad_quals);
10547 /* Else we must be instantiating the typedef, so fall through. */
10551 && code != TYPENAME_TYPE
10552 && code != TEMPLATE_TYPE_PARM
10553 && code != IDENTIFIER_NODE
10554 && code != FUNCTION_TYPE
10555 && code != METHOD_TYPE)
10556 type = tsubst (type, args, complain, in_decl);
10557 if (type == error_mark_node)
10558 return error_mark_node;
10564 case ENUMERAL_TYPE:
10565 return tsubst_aggr_type (t, args, complain, in_decl,
10566 /*entering_scope=*/0);
10569 case IDENTIFIER_NODE:
10580 if (t == integer_type_node)
10583 if (TREE_CODE (TYPE_MIN_VALUE (t)) == INTEGER_CST
10584 && TREE_CODE (TYPE_MAX_VALUE (t)) == INTEGER_CST)
10588 tree max, omax = TREE_OPERAND (TYPE_MAX_VALUE (t), 0);
10590 max = tsubst_expr (omax, args, complain, in_decl,
10591 /*integral_constant_expression_p=*/false);
10593 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
10595 if (TREE_CODE (max) == NOP_EXPR
10596 && TREE_SIDE_EFFECTS (omax)
10597 && !TREE_TYPE (max))
10598 TREE_TYPE (max) = TREE_TYPE (TREE_OPERAND (max, 0));
10600 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
10601 with TREE_SIDE_EFFECTS that indicates this is not an integral
10602 constant expression. */
10603 if (processing_template_decl
10604 && TREE_SIDE_EFFECTS (omax) && TREE_CODE (omax) == NOP_EXPR)
10606 gcc_assert (TREE_CODE (max) == NOP_EXPR);
10607 TREE_SIDE_EFFECTS (max) = 1;
10610 return compute_array_index_type (NULL_TREE, max, complain);
10613 case TEMPLATE_TYPE_PARM:
10614 case TEMPLATE_TEMPLATE_PARM:
10615 case BOUND_TEMPLATE_TEMPLATE_PARM:
10616 case TEMPLATE_PARM_INDEX:
10621 tree arg = NULL_TREE;
10625 gcc_assert (TREE_VEC_LENGTH (args) > 0);
10626 template_parm_level_and_index (t, &level, &idx);
10628 levels = TMPL_ARGS_DEPTH (args);
10629 if (level <= levels)
10631 arg = TMPL_ARG (args, level, idx);
10633 if (arg && TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
10634 /* See through ARGUMENT_PACK_SELECT arguments. */
10635 arg = ARGUMENT_PACK_SELECT_ARG (arg);
10638 if (arg == error_mark_node)
10639 return error_mark_node;
10640 else if (arg != NULL_TREE)
10642 if (ARGUMENT_PACK_P (arg))
10643 /* If ARG is an argument pack, we don't actually want to
10644 perform a substitution here, because substitutions
10645 for argument packs are only done
10646 element-by-element. We can get to this point when
10647 substituting the type of a non-type template
10648 parameter pack, when that type actually contains
10649 template parameter packs from an outer template, e.g.,
10651 template<typename... Types> struct A {
10652 template<Types... Values> struct B { };
10656 if (code == TEMPLATE_TYPE_PARM)
10659 gcc_assert (TYPE_P (arg));
10661 quals = cp_type_quals (arg) | cp_type_quals (t);
10663 return cp_build_qualified_type_real
10664 (arg, quals, complain | tf_ignore_bad_quals);
10666 else if (code == BOUND_TEMPLATE_TEMPLATE_PARM)
10668 /* We are processing a type constructed from a
10669 template template parameter. */
10670 tree argvec = tsubst (TYPE_TI_ARGS (t),
10671 args, complain, in_decl);
10672 if (argvec == error_mark_node)
10673 return error_mark_node;
10675 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
10676 are resolving nested-types in the signature of a
10677 member function templates. Otherwise ARG is a
10678 TEMPLATE_DECL and is the real template to be
10680 if (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
10681 arg = TYPE_NAME (arg);
10683 r = lookup_template_class (arg,
10685 DECL_CONTEXT (arg),
10686 /*entering_scope=*/0,
10688 return cp_build_qualified_type_real
10689 (r, cp_type_quals (t), complain);
10692 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
10693 return unshare_expr (arg);
10697 /* This can happen during the attempted tsubst'ing in
10698 unify. This means that we don't yet have any information
10699 about the template parameter in question. */
10702 /* If we get here, we must have been looking at a parm for a
10703 more deeply nested template. Make a new version of this
10704 template parameter, but with a lower level. */
10707 case TEMPLATE_TYPE_PARM:
10708 case TEMPLATE_TEMPLATE_PARM:
10709 case BOUND_TEMPLATE_TEMPLATE_PARM:
10710 if (cp_type_quals (t))
10712 r = tsubst (TYPE_MAIN_VARIANT (t), args, complain, in_decl);
10713 r = cp_build_qualified_type_real
10714 (r, cp_type_quals (t),
10715 complain | (code == TEMPLATE_TYPE_PARM
10716 ? tf_ignore_bad_quals : 0));
10721 TEMPLATE_TYPE_PARM_INDEX (r)
10722 = reduce_template_parm_level (TEMPLATE_TYPE_PARM_INDEX (t),
10723 r, levels, args, complain);
10724 TYPE_STUB_DECL (r) = TYPE_NAME (r) = TEMPLATE_TYPE_DECL (r);
10725 TYPE_MAIN_VARIANT (r) = r;
10726 TYPE_POINTER_TO (r) = NULL_TREE;
10727 TYPE_REFERENCE_TO (r) = NULL_TREE;
10729 if (TREE_CODE (r) == TEMPLATE_TEMPLATE_PARM)
10730 /* We have reduced the level of the template
10731 template parameter, but not the levels of its
10732 template parameters, so canonical_type_parameter
10733 will not be able to find the canonical template
10734 template parameter for this level. Thus, we
10735 require structural equality checking to compare
10736 TEMPLATE_TEMPLATE_PARMs. */
10737 SET_TYPE_STRUCTURAL_EQUALITY (r);
10738 else if (TYPE_STRUCTURAL_EQUALITY_P (t))
10739 SET_TYPE_STRUCTURAL_EQUALITY (r);
10741 TYPE_CANONICAL (r) = canonical_type_parameter (r);
10743 if (code == BOUND_TEMPLATE_TEMPLATE_PARM)
10745 tree argvec = tsubst (TYPE_TI_ARGS (t), args,
10746 complain, in_decl);
10747 if (argvec == error_mark_node)
10748 return error_mark_node;
10750 TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (r)
10751 = build_template_info (TYPE_TI_TEMPLATE (t), argvec);
10756 case TEMPLATE_PARM_INDEX:
10757 r = reduce_template_parm_level (t, type, levels, args, complain);
10761 gcc_unreachable ();
10769 tree purpose, value, chain;
10771 if (t == void_list_node)
10774 purpose = TREE_PURPOSE (t);
10777 purpose = tsubst (purpose, args, complain, in_decl);
10778 if (purpose == error_mark_node)
10779 return error_mark_node;
10781 value = TREE_VALUE (t);
10784 value = tsubst (value, args, complain, in_decl);
10785 if (value == error_mark_node)
10786 return error_mark_node;
10788 chain = TREE_CHAIN (t);
10789 if (chain && chain != void_type_node)
10791 chain = tsubst (chain, args, complain, in_decl);
10792 if (chain == error_mark_node)
10793 return error_mark_node;
10795 if (purpose == TREE_PURPOSE (t)
10796 && value == TREE_VALUE (t)
10797 && chain == TREE_CHAIN (t))
10799 return hash_tree_cons (purpose, value, chain);
10803 /* We should never be tsubsting a binfo. */
10804 gcc_unreachable ();
10807 /* A vector of template arguments. */
10808 gcc_assert (!type);
10809 return tsubst_template_args (t, args, complain, in_decl);
10812 case REFERENCE_TYPE:
10814 if (type == TREE_TYPE (t) && TREE_CODE (type) != METHOD_TYPE)
10819 Type deduction may fail for any of the following
10822 -- Attempting to create a pointer to reference type.
10823 -- Attempting to create a reference to a reference type or
10824 a reference to void.
10826 Core issue 106 says that creating a reference to a reference
10827 during instantiation is no longer a cause for failure. We
10828 only enforce this check in strict C++98 mode. */
10829 if ((TREE_CODE (type) == REFERENCE_TYPE
10830 && (((cxx_dialect == cxx98) && flag_iso) || code != REFERENCE_TYPE))
10831 || (code == REFERENCE_TYPE && TREE_CODE (type) == VOID_TYPE))
10833 static location_t last_loc;
10835 /* We keep track of the last time we issued this error
10836 message to avoid spewing a ton of messages during a
10837 single bad template instantiation. */
10838 if (complain & tf_error
10839 && last_loc != input_location)
10841 if (TREE_CODE (type) == VOID_TYPE)
10842 error ("forming reference to void");
10843 else if (code == POINTER_TYPE)
10844 error ("forming pointer to reference type %qT", type);
10846 error ("forming reference to reference type %qT", type);
10847 last_loc = input_location;
10850 return error_mark_node;
10852 else if (code == POINTER_TYPE)
10854 r = build_pointer_type (type);
10855 if (TREE_CODE (type) == METHOD_TYPE)
10856 r = build_ptrmemfunc_type (r);
10858 else if (TREE_CODE (type) == REFERENCE_TYPE)
10859 /* In C++0x, during template argument substitution, when there is an
10860 attempt to create a reference to a reference type, reference
10861 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
10863 "If a template-argument for a template-parameter T names a type
10864 that is a reference to a type A, an attempt to create the type
10865 'lvalue reference to cv T' creates the type 'lvalue reference to
10866 A,' while an attempt to create the type type rvalue reference to
10867 cv T' creates the type T"
10869 r = cp_build_reference_type
10871 TYPE_REF_IS_RVALUE (t) && TYPE_REF_IS_RVALUE (type));
10873 r = cp_build_reference_type (type, TYPE_REF_IS_RVALUE (t));
10874 r = cp_build_qualified_type_real (r, cp_type_quals (t), complain);
10876 if (r != error_mark_node)
10877 /* Will this ever be needed for TYPE_..._TO values? */
10884 r = tsubst (TYPE_OFFSET_BASETYPE (t), args, complain, in_decl);
10885 if (r == error_mark_node || !MAYBE_CLASS_TYPE_P (r))
10889 Type deduction may fail for any of the following
10892 -- Attempting to create "pointer to member of T" when T
10893 is not a class type. */
10894 if (complain & tf_error)
10895 error ("creating pointer to member of non-class type %qT", r);
10896 return error_mark_node;
10898 if (TREE_CODE (type) == REFERENCE_TYPE)
10900 if (complain & tf_error)
10901 error ("creating pointer to member reference type %qT", type);
10902 return error_mark_node;
10904 if (TREE_CODE (type) == VOID_TYPE)
10906 if (complain & tf_error)
10907 error ("creating pointer to member of type void");
10908 return error_mark_node;
10910 gcc_assert (TREE_CODE (type) != METHOD_TYPE);
10911 if (TREE_CODE (type) == FUNCTION_TYPE)
10913 /* The type of the implicit object parameter gets its
10914 cv-qualifiers from the FUNCTION_TYPE. */
10916 tree method_type = build_memfn_type (type, r, type_memfn_quals (type));
10917 memptr = build_ptrmemfunc_type (build_pointer_type (method_type));
10918 return cp_build_qualified_type_real (memptr, cp_type_quals (t),
10922 return cp_build_qualified_type_real (build_ptrmem_type (r, type),
10926 case FUNCTION_TYPE:
10931 fntype = tsubst_function_type (t, args, complain, in_decl);
10932 if (fntype == error_mark_node)
10933 return error_mark_node;
10935 /* Substitute the exception specification. */
10936 specs = tsubst_exception_specification (t, args, complain,
10937 in_decl, /*defer_ok*/true);
10938 if (specs == error_mark_node)
10939 return error_mark_node;
10941 fntype = build_exception_variant (fntype, specs);
10946 tree domain = tsubst (TYPE_DOMAIN (t), args, complain, in_decl);
10947 if (domain == error_mark_node)
10948 return error_mark_node;
10950 /* As an optimization, we avoid regenerating the array type if
10951 it will obviously be the same as T. */
10952 if (type == TREE_TYPE (t) && domain == TYPE_DOMAIN (t))
10955 /* These checks should match the ones in grokdeclarator.
10959 The deduction may fail for any of the following reasons:
10961 -- Attempting to create an array with an element type that
10962 is void, a function type, or a reference type, or [DR337]
10963 an abstract class type. */
10964 if (TREE_CODE (type) == VOID_TYPE
10965 || TREE_CODE (type) == FUNCTION_TYPE
10966 || TREE_CODE (type) == REFERENCE_TYPE)
10968 if (complain & tf_error)
10969 error ("creating array of %qT", type);
10970 return error_mark_node;
10972 if (CLASS_TYPE_P (type) && CLASSTYPE_PURE_VIRTUALS (type))
10974 if (complain & tf_error)
10975 error ("creating array of %qT, which is an abstract class type",
10977 return error_mark_node;
10980 r = build_cplus_array_type (type, domain);
10982 if (TYPE_USER_ALIGN (t))
10984 TYPE_ALIGN (r) = TYPE_ALIGN (t);
10985 TYPE_USER_ALIGN (r) = 1;
10991 case TYPENAME_TYPE:
10993 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
10994 in_decl, /*entering_scope=*/1);
10995 tree f = tsubst_copy (TYPENAME_TYPE_FULLNAME (t), args,
10996 complain, in_decl);
10998 if (ctx == error_mark_node || f == error_mark_node)
10999 return error_mark_node;
11001 if (!MAYBE_CLASS_TYPE_P (ctx))
11003 if (complain & tf_error)
11004 error ("%qT is not a class, struct, or union type", ctx);
11005 return error_mark_node;
11007 else if (!uses_template_parms (ctx) && !TYPE_BEING_DEFINED (ctx))
11009 /* Normally, make_typename_type does not require that the CTX
11010 have complete type in order to allow things like:
11012 template <class T> struct S { typename S<T>::X Y; };
11014 But, such constructs have already been resolved by this
11015 point, so here CTX really should have complete type, unless
11016 it's a partial instantiation. */
11017 ctx = complete_type (ctx);
11018 if (!COMPLETE_TYPE_P (ctx))
11020 if (complain & tf_error)
11021 cxx_incomplete_type_error (NULL_TREE, ctx);
11022 return error_mark_node;
11026 f = make_typename_type (ctx, f, typename_type,
11027 (complain & tf_error) | tf_keep_type_decl);
11028 if (f == error_mark_node)
11030 if (TREE_CODE (f) == TYPE_DECL)
11032 complain |= tf_ignore_bad_quals;
11036 if (TREE_CODE (f) != TYPENAME_TYPE)
11038 if (TYPENAME_IS_ENUM_P (t) && TREE_CODE (f) != ENUMERAL_TYPE)
11040 if (complain & tf_error)
11041 error ("%qT resolves to %qT, which is not an enumeration type",
11044 return error_mark_node;
11046 else if (TYPENAME_IS_CLASS_P (t) && !CLASS_TYPE_P (f))
11048 if (complain & tf_error)
11049 error ("%qT resolves to %qT, which is is not a class type",
11052 return error_mark_node;
11056 return cp_build_qualified_type_real
11057 (f, cp_type_quals (f) | cp_type_quals (t), complain);
11060 case UNBOUND_CLASS_TEMPLATE:
11062 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
11063 in_decl, /*entering_scope=*/1);
11064 tree name = TYPE_IDENTIFIER (t);
11065 tree parm_list = DECL_TEMPLATE_PARMS (TYPE_NAME (t));
11067 if (ctx == error_mark_node || name == error_mark_node)
11068 return error_mark_node;
11071 parm_list = tsubst_template_parms (parm_list, args, complain);
11072 return make_unbound_class_template (ctx, name, parm_list, complain);
11079 ++cp_unevaluated_operand;
11080 ++c_inhibit_evaluation_warnings;
11082 type = tsubst_expr (TYPEOF_TYPE_EXPR (t), args,
11084 /*integral_constant_expression_p=*/false);
11086 --cp_unevaluated_operand;
11087 --c_inhibit_evaluation_warnings;
11089 type = finish_typeof (type);
11090 return cp_build_qualified_type_real (type,
11092 | cp_type_quals (type),
11096 case DECLTYPE_TYPE:
11100 ++cp_unevaluated_operand;
11101 ++c_inhibit_evaluation_warnings;
11103 type = tsubst_expr (DECLTYPE_TYPE_EXPR (t), args,
11105 /*integral_constant_expression_p=*/false);
11107 --cp_unevaluated_operand;
11108 --c_inhibit_evaluation_warnings;
11110 if (DECLTYPE_FOR_LAMBDA_CAPTURE (t))
11111 type = lambda_capture_field_type (type);
11112 else if (DECLTYPE_FOR_LAMBDA_RETURN (t))
11113 type = lambda_return_type (type);
11114 else if (DECLTYPE_FOR_LAMBDA_PROXY (t))
11115 type = lambda_proxy_type (type);
11117 type = finish_decltype_type
11118 (type, DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t), complain);
11119 return cp_build_qualified_type_real (type,
11121 | cp_type_quals (type),
11125 case UNDERLYING_TYPE:
11127 tree type = tsubst (UNDERLYING_TYPE_TYPE (t), args,
11128 complain, in_decl);
11129 return finish_underlying_type (type);
11132 case TYPE_ARGUMENT_PACK:
11133 case NONTYPE_ARGUMENT_PACK:
11135 tree r = TYPE_P (t) ? cxx_make_type (code) : make_node (code);
11137 tsubst_template_args (ARGUMENT_PACK_ARGS (t),
11141 SET_ARGUMENT_PACK_ARGS (r, packed_out);
11143 /* For template nontype argument packs, also substitute into
11145 if (code == NONTYPE_ARGUMENT_PACK)
11146 TREE_TYPE (r) = tsubst (TREE_TYPE (t), args, complain, in_decl);
11164 /* We should use one of the expression tsubsts for these codes. */
11165 gcc_unreachable ();
11168 sorry ("use of %qs in template", tree_code_name [(int) code]);
11169 return error_mark_node;
11173 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
11174 type of the expression on the left-hand side of the "." or "->"
11178 tsubst_baselink (tree baselink, tree object_type,
11179 tree args, tsubst_flags_t complain, tree in_decl)
11182 tree qualifying_scope;
11185 tree template_args = 0;
11186 bool template_id_p = false;
11188 /* A baselink indicates a function from a base class. Both the
11189 BASELINK_ACCESS_BINFO and the base class referenced may
11190 indicate bases of the template class, rather than the
11191 instantiated class. In addition, lookups that were not
11192 ambiguous before may be ambiguous now. Therefore, we perform
11193 the lookup again. */
11194 qualifying_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (baselink));
11195 qualifying_scope = tsubst (qualifying_scope, args,
11196 complain, in_decl);
11197 fns = BASELINK_FUNCTIONS (baselink);
11198 optype = tsubst (BASELINK_OPTYPE (baselink), args, complain, in_decl);
11199 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
11201 template_id_p = true;
11202 template_args = TREE_OPERAND (fns, 1);
11203 fns = TREE_OPERAND (fns, 0);
11205 template_args = tsubst_template_args (template_args, args,
11206 complain, in_decl);
11208 name = DECL_NAME (get_first_fn (fns));
11209 if (IDENTIFIER_TYPENAME_P (name))
11210 name = mangle_conv_op_name_for_type (optype);
11211 baselink = lookup_fnfields (qualifying_scope, name, /*protect=*/1);
11213 return error_mark_node;
11215 /* If lookup found a single function, mark it as used at this
11216 point. (If it lookup found multiple functions the one selected
11217 later by overload resolution will be marked as used at that
11219 if (BASELINK_P (baselink))
11220 fns = BASELINK_FUNCTIONS (baselink);
11221 if (!template_id_p && !really_overloaded_fn (fns))
11222 mark_used (OVL_CURRENT (fns));
11224 /* Add back the template arguments, if present. */
11225 if (BASELINK_P (baselink) && template_id_p)
11226 BASELINK_FUNCTIONS (baselink)
11227 = build_nt (TEMPLATE_ID_EXPR,
11228 BASELINK_FUNCTIONS (baselink),
11230 /* Update the conversion operator type. */
11231 BASELINK_OPTYPE (baselink) = optype;
11234 object_type = current_class_type;
11235 return adjust_result_of_qualified_name_lookup (baselink,
11240 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
11241 true if the qualified-id will be a postfix-expression in-and-of
11242 itself; false if more of the postfix-expression follows the
11243 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
11247 tsubst_qualified_id (tree qualified_id, tree args,
11248 tsubst_flags_t complain, tree in_decl,
11249 bool done, bool address_p)
11255 tree template_args;
11257 gcc_assert (TREE_CODE (qualified_id) == SCOPE_REF);
11259 /* Figure out what name to look up. */
11260 name = TREE_OPERAND (qualified_id, 1);
11261 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
11263 is_template = true;
11264 template_args = TREE_OPERAND (name, 1);
11266 template_args = tsubst_template_args (template_args, args,
11267 complain, in_decl);
11268 name = TREE_OPERAND (name, 0);
11272 is_template = false;
11273 template_args = NULL_TREE;
11276 /* Substitute into the qualifying scope. When there are no ARGS, we
11277 are just trying to simplify a non-dependent expression. In that
11278 case the qualifying scope may be dependent, and, in any case,
11279 substituting will not help. */
11280 scope = TREE_OPERAND (qualified_id, 0);
11283 scope = tsubst (scope, args, complain, in_decl);
11284 expr = tsubst_copy (name, args, complain, in_decl);
11289 if (dependent_scope_p (scope))
11290 return build_qualified_name (NULL_TREE, scope, expr,
11291 QUALIFIED_NAME_IS_TEMPLATE (qualified_id));
11293 if (!BASELINK_P (name) && !DECL_P (expr))
11295 if (TREE_CODE (expr) == BIT_NOT_EXPR)
11297 /* A BIT_NOT_EXPR is used to represent a destructor. */
11298 if (!check_dtor_name (scope, TREE_OPERAND (expr, 0)))
11300 error ("qualifying type %qT does not match destructor name ~%qT",
11301 scope, TREE_OPERAND (expr, 0));
11302 expr = error_mark_node;
11305 expr = lookup_qualified_name (scope, complete_dtor_identifier,
11306 /*is_type_p=*/0, false);
11309 expr = lookup_qualified_name (scope, expr, /*is_type_p=*/0, false);
11310 if (TREE_CODE (TREE_CODE (expr) == TEMPLATE_DECL
11311 ? DECL_TEMPLATE_RESULT (expr) : expr) == TYPE_DECL)
11313 if (complain & tf_error)
11315 error ("dependent-name %qE is parsed as a non-type, but "
11316 "instantiation yields a type", qualified_id);
11317 inform (input_location, "say %<typename %E%> if a type is meant", qualified_id);
11319 return error_mark_node;
11325 check_accessibility_of_qualified_id (expr, /*object_type=*/NULL_TREE,
11327 /* Remember that there was a reference to this entity. */
11331 if (expr == error_mark_node || TREE_CODE (expr) == TREE_LIST)
11333 if (complain & tf_error)
11334 qualified_name_lookup_error (scope,
11335 TREE_OPERAND (qualified_id, 1),
11336 expr, input_location);
11337 return error_mark_node;
11341 expr = lookup_template_function (expr, template_args);
11343 if (expr == error_mark_node && complain & tf_error)
11344 qualified_name_lookup_error (scope, TREE_OPERAND (qualified_id, 1),
11345 expr, input_location);
11346 else if (TYPE_P (scope))
11348 expr = (adjust_result_of_qualified_name_lookup
11349 (expr, scope, current_class_type));
11350 expr = (finish_qualified_id_expr
11351 (scope, expr, done, address_p && PTRMEM_OK_P (qualified_id),
11352 QUALIFIED_NAME_IS_TEMPLATE (qualified_id),
11353 /*template_arg_p=*/false));
11356 /* Expressions do not generally have reference type. */
11357 if (TREE_CODE (expr) != SCOPE_REF
11358 /* However, if we're about to form a pointer-to-member, we just
11359 want the referenced member referenced. */
11360 && TREE_CODE (expr) != OFFSET_REF)
11361 expr = convert_from_reference (expr);
11366 /* Like tsubst, but deals with expressions. This function just replaces
11367 template parms; to finish processing the resultant expression, use
11371 tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl)
11373 enum tree_code code;
11376 if (t == NULL_TREE || t == error_mark_node || args == NULL_TREE)
11379 code = TREE_CODE (t);
11384 r = retrieve_local_specialization (t);
11389 /* This can happen for a parameter name used later in a function
11390 declaration (such as in a late-specified return type). Just
11391 make a dummy decl, since it's only used for its type. */
11392 gcc_assert (cp_unevaluated_operand != 0);
11393 /* We copy T because want to tsubst the PARM_DECL only,
11394 not the following PARM_DECLs that are chained to T. */
11396 r = tsubst_decl (c, args, complain);
11397 /* Give it the template pattern as its context; its true context
11398 hasn't been instantiated yet and this is good enough for
11400 DECL_CONTEXT (r) = DECL_CONTEXT (t);
11403 if (TREE_CODE (r) == ARGUMENT_PACK_SELECT)
11404 r = ARGUMENT_PACK_SELECT_ARG (r);
11413 if (DECL_TEMPLATE_PARM_P (t))
11414 return tsubst_copy (DECL_INITIAL (t), args, complain, in_decl);
11415 /* There is no need to substitute into namespace-scope
11417 if (DECL_NAMESPACE_SCOPE_P (t))
11419 /* If ARGS is NULL, then T is known to be non-dependent. */
11420 if (args == NULL_TREE)
11421 return integral_constant_value (t);
11423 /* Unfortunately, we cannot just call lookup_name here.
11426 template <int I> int f() {
11428 struct S { void g() { E e = a; } };
11431 When we instantiate f<7>::S::g(), say, lookup_name is not
11432 clever enough to find f<7>::a. */
11434 = tsubst_aggr_type (TREE_TYPE (t), args, complain, in_decl,
11435 /*entering_scope=*/0);
11437 for (v = TYPE_VALUES (enum_type);
11439 v = TREE_CHAIN (v))
11440 if (TREE_PURPOSE (v) == DECL_NAME (t))
11441 return TREE_VALUE (v);
11443 /* We didn't find the name. That should never happen; if
11444 name-lookup found it during preliminary parsing, we
11445 should find it again here during instantiation. */
11446 gcc_unreachable ();
11451 if (DECL_CONTEXT (t))
11455 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args, complain, in_decl,
11456 /*entering_scope=*/1);
11457 if (ctx != DECL_CONTEXT (t))
11459 tree r = lookup_field (ctx, DECL_NAME (t), 0, false);
11462 if (complain & tf_error)
11463 error ("using invalid field %qD", t);
11464 return error_mark_node;
11473 case FUNCTION_DECL:
11474 if ((DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t))
11475 || local_variable_p (t))
11476 t = tsubst (t, args, complain, in_decl);
11481 /* An OVERLOAD will always be a non-dependent overload set; an
11482 overload set from function scope will just be represented with an
11483 IDENTIFIER_NODE, and from class scope with a BASELINK. */
11484 gcc_assert (!uses_template_parms (t));
11488 return tsubst_baselink (t, current_class_type, args, complain, in_decl);
11490 case TEMPLATE_DECL:
11491 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
11492 return tsubst (TREE_TYPE (DECL_TEMPLATE_RESULT (t)),
11493 args, complain, in_decl);
11494 else if (DECL_FUNCTION_TEMPLATE_P (t) && DECL_MEMBER_TEMPLATE_P (t))
11495 return tsubst (t, args, complain, in_decl);
11496 else if (DECL_CLASS_SCOPE_P (t)
11497 && uses_template_parms (DECL_CONTEXT (t)))
11499 /* Template template argument like the following example need
11502 template <template <class> class TT> struct C {};
11503 template <class T> struct D {
11504 template <class U> struct E {};
11509 We are processing the template argument `E' in #1 for
11510 the template instantiation #2. Originally, `E' is a
11511 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
11512 have to substitute this with one having context `D<int>'. */
11514 tree context = tsubst (DECL_CONTEXT (t), args, complain, in_decl);
11515 return lookup_field (context, DECL_NAME(t), 0, false);
11518 /* Ordinary template template argument. */
11522 case REINTERPRET_CAST_EXPR:
11523 case CONST_CAST_EXPR:
11524 case STATIC_CAST_EXPR:
11525 case DYNAMIC_CAST_EXPR:
11528 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
11529 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
11532 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
11538 ++cp_unevaluated_operand;
11539 ++c_inhibit_evaluation_warnings;
11540 /* We only want to compute the number of arguments. */
11541 expanded = tsubst_pack_expansion (TREE_OPERAND (t, 0), args,
11542 complain, in_decl);
11543 --cp_unevaluated_operand;
11544 --c_inhibit_evaluation_warnings;
11546 if (TREE_CODE (expanded) == TREE_VEC)
11547 len = TREE_VEC_LENGTH (expanded);
11549 if (expanded == error_mark_node)
11550 return error_mark_node;
11551 else if (PACK_EXPANSION_P (expanded)
11552 || (TREE_CODE (expanded) == TREE_VEC
11554 && PACK_EXPANSION_P (TREE_VEC_ELT (expanded, len-1))))
11556 if (TREE_CODE (expanded) == TREE_VEC)
11557 expanded = TREE_VEC_ELT (expanded, len - 1);
11559 if (TYPE_P (expanded))
11560 return cxx_sizeof_or_alignof_type (expanded, SIZEOF_EXPR,
11561 complain & tf_error);
11563 return cxx_sizeof_or_alignof_expr (expanded, SIZEOF_EXPR,
11564 complain & tf_error);
11567 return build_int_cst (size_type_node, len);
11573 case TRUTH_NOT_EXPR:
11576 case UNARY_PLUS_EXPR: /* Unary + */
11578 case AT_ENCODE_EXPR:
11582 case REALPART_EXPR:
11583 case IMAGPART_EXPR:
11585 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
11586 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
11588 case COMPONENT_REF:
11593 object = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
11594 name = TREE_OPERAND (t, 1);
11595 if (TREE_CODE (name) == BIT_NOT_EXPR)
11597 name = tsubst_copy (TREE_OPERAND (name, 0), args,
11598 complain, in_decl);
11599 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
11601 else if (TREE_CODE (name) == SCOPE_REF
11602 && TREE_CODE (TREE_OPERAND (name, 1)) == BIT_NOT_EXPR)
11604 tree base = tsubst_copy (TREE_OPERAND (name, 0), args,
11605 complain, in_decl);
11606 name = TREE_OPERAND (name, 1);
11607 name = tsubst_copy (TREE_OPERAND (name, 0), args,
11608 complain, in_decl);
11609 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
11610 name = build_qualified_name (/*type=*/NULL_TREE,
11612 /*template_p=*/false);
11614 else if (TREE_CODE (name) == BASELINK)
11615 name = tsubst_baselink (name,
11616 non_reference (TREE_TYPE (object)),
11620 name = tsubst_copy (name, args, complain, in_decl);
11621 return build_nt (COMPONENT_REF, object, name, NULL_TREE);
11627 case TRUNC_DIV_EXPR:
11628 case CEIL_DIV_EXPR:
11629 case FLOOR_DIV_EXPR:
11630 case ROUND_DIV_EXPR:
11631 case EXACT_DIV_EXPR:
11635 case TRUNC_MOD_EXPR:
11636 case FLOOR_MOD_EXPR:
11637 case TRUTH_ANDIF_EXPR:
11638 case TRUTH_ORIF_EXPR:
11639 case TRUTH_AND_EXPR:
11640 case TRUTH_OR_EXPR:
11653 case COMPOUND_EXPR:
11656 case PREDECREMENT_EXPR:
11657 case PREINCREMENT_EXPR:
11658 case POSTDECREMENT_EXPR:
11659 case POSTINCREMENT_EXPR:
11661 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11662 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
11665 return build_qualified_name (/*type=*/NULL_TREE,
11666 tsubst_copy (TREE_OPERAND (t, 0),
11667 args, complain, in_decl),
11668 tsubst_copy (TREE_OPERAND (t, 1),
11669 args, complain, in_decl),
11670 QUALIFIED_NAME_IS_TEMPLATE (t));
11675 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11676 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
11677 NULL_TREE, NULL_TREE);
11681 int n = VL_EXP_OPERAND_LENGTH (t);
11682 tree result = build_vl_exp (CALL_EXPR, n);
11684 for (i = 0; i < n; i++)
11685 TREE_OPERAND (t, i) = tsubst_copy (TREE_OPERAND (t, i), args,
11686 complain, in_decl);
11692 case PSEUDO_DTOR_EXPR:
11695 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11696 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
11697 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
11698 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
11705 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11706 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
11707 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
11708 NEW_EXPR_USE_GLOBAL (r) = NEW_EXPR_USE_GLOBAL (t);
11715 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11716 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
11717 DELETE_EXPR_USE_GLOBAL (r) = DELETE_EXPR_USE_GLOBAL (t);
11718 DELETE_EXPR_USE_VEC (r) = DELETE_EXPR_USE_VEC (t);
11722 case TEMPLATE_ID_EXPR:
11724 /* Substituted template arguments */
11725 tree fn = TREE_OPERAND (t, 0);
11726 tree targs = TREE_OPERAND (t, 1);
11728 fn = tsubst_copy (fn, args, complain, in_decl);
11730 targs = tsubst_template_args (targs, args, complain, in_decl);
11732 return lookup_template_function (fn, targs);
11737 tree purpose, value, chain;
11739 if (t == void_list_node)
11742 purpose = TREE_PURPOSE (t);
11744 purpose = tsubst_copy (purpose, args, complain, in_decl);
11745 value = TREE_VALUE (t);
11747 value = tsubst_copy (value, args, complain, in_decl);
11748 chain = TREE_CHAIN (t);
11749 if (chain && chain != void_type_node)
11750 chain = tsubst_copy (chain, args, complain, in_decl);
11751 if (purpose == TREE_PURPOSE (t)
11752 && value == TREE_VALUE (t)
11753 && chain == TREE_CHAIN (t))
11755 return tree_cons (purpose, value, chain);
11760 case ENUMERAL_TYPE:
11762 case TEMPLATE_TYPE_PARM:
11763 case TEMPLATE_TEMPLATE_PARM:
11764 case BOUND_TEMPLATE_TEMPLATE_PARM:
11765 case TEMPLATE_PARM_INDEX:
11767 case REFERENCE_TYPE:
11769 case FUNCTION_TYPE:
11772 case TYPENAME_TYPE:
11773 case UNBOUND_CLASS_TEMPLATE:
11775 case DECLTYPE_TYPE:
11777 return tsubst (t, args, complain, in_decl);
11779 case IDENTIFIER_NODE:
11780 if (IDENTIFIER_TYPENAME_P (t))
11782 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
11783 return mangle_conv_op_name_for_type (new_type);
11789 /* This is handled by tsubst_copy_and_build. */
11790 gcc_unreachable ();
11793 return build_x_va_arg (tsubst_copy (TREE_OPERAND (t, 0), args, complain,
11795 tsubst (TREE_TYPE (t), args, complain, in_decl));
11797 case CLEANUP_POINT_EXPR:
11798 /* We shouldn't have built any of these during initial template
11799 generation. Instead, they should be built during instantiation
11800 in response to the saved STMT_IS_FULL_EXPR_P setting. */
11801 gcc_unreachable ();
11805 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
11806 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11807 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
11808 PTRMEM_OK_P (r) = PTRMEM_OK_P (t);
11809 mark_used (TREE_OPERAND (r, 1));
11812 case EXPR_PACK_EXPANSION:
11813 error ("invalid use of pack expansion expression");
11814 return error_mark_node;
11816 case NONTYPE_ARGUMENT_PACK:
11817 error ("use %<...%> to expand argument pack");
11818 return error_mark_node;
11825 /* Instantiate any typedefs in the type. */
11826 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
11827 r = fold_convert (type, t);
11828 gcc_assert (TREE_CODE (r) == code);
11833 /* These can sometimes show up in a partial instantiation, but never
11834 involve template parms. */
11835 gcc_assert (!uses_template_parms (t));
11839 /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */
11840 gcc_checking_assert (false);
11845 /* Like tsubst_copy, but specifically for OpenMP clauses. */
11848 tsubst_omp_clauses (tree clauses, tree args, tsubst_flags_t complain,
11851 tree new_clauses = NULL, nc, oc;
11853 for (oc = clauses; oc ; oc = OMP_CLAUSE_CHAIN (oc))
11855 nc = copy_node (oc);
11856 OMP_CLAUSE_CHAIN (nc) = new_clauses;
11859 switch (OMP_CLAUSE_CODE (nc))
11861 case OMP_CLAUSE_LASTPRIVATE:
11862 if (OMP_CLAUSE_LASTPRIVATE_STMT (oc))
11864 OMP_CLAUSE_LASTPRIVATE_STMT (nc) = push_stmt_list ();
11865 tsubst_expr (OMP_CLAUSE_LASTPRIVATE_STMT (oc), args, complain,
11866 in_decl, /*integral_constant_expression_p=*/false);
11867 OMP_CLAUSE_LASTPRIVATE_STMT (nc)
11868 = pop_stmt_list (OMP_CLAUSE_LASTPRIVATE_STMT (nc));
11871 case OMP_CLAUSE_PRIVATE:
11872 case OMP_CLAUSE_SHARED:
11873 case OMP_CLAUSE_FIRSTPRIVATE:
11874 case OMP_CLAUSE_REDUCTION:
11875 case OMP_CLAUSE_COPYIN:
11876 case OMP_CLAUSE_COPYPRIVATE:
11877 case OMP_CLAUSE_IF:
11878 case OMP_CLAUSE_NUM_THREADS:
11879 case OMP_CLAUSE_SCHEDULE:
11880 case OMP_CLAUSE_COLLAPSE:
11881 OMP_CLAUSE_OPERAND (nc, 0)
11882 = tsubst_expr (OMP_CLAUSE_OPERAND (oc, 0), args, complain,
11883 in_decl, /*integral_constant_expression_p=*/false);
11885 case OMP_CLAUSE_NOWAIT:
11886 case OMP_CLAUSE_ORDERED:
11887 case OMP_CLAUSE_DEFAULT:
11888 case OMP_CLAUSE_UNTIED:
11891 gcc_unreachable ();
11895 return finish_omp_clauses (nreverse (new_clauses));
11898 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
11901 tsubst_copy_asm_operands (tree t, tree args, tsubst_flags_t complain,
11904 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
11906 tree purpose, value, chain;
11911 if (TREE_CODE (t) != TREE_LIST)
11912 return tsubst_copy_and_build (t, args, complain, in_decl,
11913 /*function_p=*/false,
11914 /*integral_constant_expression_p=*/false);
11916 if (t == void_list_node)
11919 purpose = TREE_PURPOSE (t);
11921 purpose = RECUR (purpose);
11922 value = TREE_VALUE (t);
11923 if (value && TREE_CODE (value) != LABEL_DECL)
11924 value = RECUR (value);
11925 chain = TREE_CHAIN (t);
11926 if (chain && chain != void_type_node)
11927 chain = RECUR (chain);
11928 return tree_cons (purpose, value, chain);
11932 /* Substitute one OMP_FOR iterator. */
11935 tsubst_omp_for_iterator (tree t, int i, tree declv, tree initv,
11936 tree condv, tree incrv, tree *clauses,
11937 tree args, tsubst_flags_t complain, tree in_decl,
11938 bool integral_constant_expression_p)
11940 #define RECUR(NODE) \
11941 tsubst_expr ((NODE), args, complain, in_decl, \
11942 integral_constant_expression_p)
11943 tree decl, init, cond, incr, auto_node;
11945 init = TREE_VEC_ELT (OMP_FOR_INIT (t), i);
11946 gcc_assert (TREE_CODE (init) == MODIFY_EXPR);
11947 decl = RECUR (TREE_OPERAND (init, 0));
11948 init = TREE_OPERAND (init, 1);
11949 auto_node = type_uses_auto (TREE_TYPE (decl));
11950 if (auto_node && init)
11952 tree init_expr = init;
11953 if (TREE_CODE (init_expr) == DECL_EXPR)
11954 init_expr = DECL_INITIAL (DECL_EXPR_DECL (init_expr));
11955 init_expr = RECUR (init_expr);
11957 = do_auto_deduction (TREE_TYPE (decl), init_expr, auto_node);
11959 gcc_assert (!type_dependent_expression_p (decl));
11961 if (!CLASS_TYPE_P (TREE_TYPE (decl)))
11963 cond = RECUR (TREE_VEC_ELT (OMP_FOR_COND (t), i));
11964 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
11965 if (TREE_CODE (incr) == MODIFY_EXPR)
11966 incr = build_x_modify_expr (RECUR (TREE_OPERAND (incr, 0)), NOP_EXPR,
11967 RECUR (TREE_OPERAND (incr, 1)),
11970 incr = RECUR (incr);
11971 TREE_VEC_ELT (declv, i) = decl;
11972 TREE_VEC_ELT (initv, i) = init;
11973 TREE_VEC_ELT (condv, i) = cond;
11974 TREE_VEC_ELT (incrv, i) = incr;
11978 if (init && TREE_CODE (init) != DECL_EXPR)
11981 for (c = *clauses; c ; c = OMP_CLAUSE_CHAIN (c))
11983 if ((OMP_CLAUSE_CODE (c) == OMP_CLAUSE_PRIVATE
11984 || OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LASTPRIVATE)
11985 && OMP_CLAUSE_DECL (c) == decl)
11987 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_FIRSTPRIVATE
11988 && OMP_CLAUSE_DECL (c) == decl)
11989 error ("iteration variable %qD should not be firstprivate", decl);
11990 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_REDUCTION
11991 && OMP_CLAUSE_DECL (c) == decl)
11992 error ("iteration variable %qD should not be reduction", decl);
11996 c = build_omp_clause (input_location, OMP_CLAUSE_PRIVATE);
11997 OMP_CLAUSE_DECL (c) = decl;
11998 c = finish_omp_clauses (c);
12001 OMP_CLAUSE_CHAIN (c) = *clauses;
12006 cond = TREE_VEC_ELT (OMP_FOR_COND (t), i);
12007 if (COMPARISON_CLASS_P (cond))
12008 cond = build2 (TREE_CODE (cond), boolean_type_node,
12009 RECUR (TREE_OPERAND (cond, 0)),
12010 RECUR (TREE_OPERAND (cond, 1)));
12012 cond = RECUR (cond);
12013 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
12014 switch (TREE_CODE (incr))
12016 case PREINCREMENT_EXPR:
12017 case PREDECREMENT_EXPR:
12018 case POSTINCREMENT_EXPR:
12019 case POSTDECREMENT_EXPR:
12020 incr = build2 (TREE_CODE (incr), TREE_TYPE (decl),
12021 RECUR (TREE_OPERAND (incr, 0)), NULL_TREE);
12024 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
12025 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
12027 tree rhs = TREE_OPERAND (incr, 1);
12028 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
12029 RECUR (TREE_OPERAND (incr, 0)),
12030 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
12031 RECUR (TREE_OPERAND (rhs, 0)),
12032 RECUR (TREE_OPERAND (rhs, 1))));
12035 incr = RECUR (incr);
12038 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
12039 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
12041 tree lhs = RECUR (TREE_OPERAND (incr, 0));
12042 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl), lhs,
12043 build2 (TREE_CODE (TREE_OPERAND (incr, 1)),
12044 TREE_TYPE (decl), lhs,
12045 RECUR (TREE_OPERAND (incr, 2))));
12047 else if (TREE_CODE (TREE_OPERAND (incr, 1)) == NOP_EXPR
12048 && (TREE_CODE (TREE_OPERAND (incr, 2)) == PLUS_EXPR
12049 || (TREE_CODE (TREE_OPERAND (incr, 2)) == MINUS_EXPR)))
12051 tree rhs = TREE_OPERAND (incr, 2);
12052 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
12053 RECUR (TREE_OPERAND (incr, 0)),
12054 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
12055 RECUR (TREE_OPERAND (rhs, 0)),
12056 RECUR (TREE_OPERAND (rhs, 1))));
12059 incr = RECUR (incr);
12062 incr = RECUR (incr);
12066 TREE_VEC_ELT (declv, i) = decl;
12067 TREE_VEC_ELT (initv, i) = init;
12068 TREE_VEC_ELT (condv, i) = cond;
12069 TREE_VEC_ELT (incrv, i) = incr;
12073 /* Like tsubst_copy for expressions, etc. but also does semantic
12077 tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl,
12078 bool integral_constant_expression_p)
12080 #define RECUR(NODE) \
12081 tsubst_expr ((NODE), args, complain, in_decl, \
12082 integral_constant_expression_p)
12086 if (t == NULL_TREE || t == error_mark_node)
12089 if (EXPR_HAS_LOCATION (t))
12090 input_location = EXPR_LOCATION (t);
12091 if (STATEMENT_CODE_P (TREE_CODE (t)))
12092 current_stmt_tree ()->stmts_are_full_exprs_p = STMT_IS_FULL_EXPR_P (t);
12094 switch (TREE_CODE (t))
12096 case STATEMENT_LIST:
12098 tree_stmt_iterator i;
12099 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
12100 RECUR (tsi_stmt (i));
12104 case CTOR_INITIALIZER:
12105 finish_mem_initializers (tsubst_initializer_list
12106 (TREE_OPERAND (t, 0), args));
12110 finish_return_stmt (RECUR (TREE_OPERAND (t, 0)));
12114 tmp = RECUR (EXPR_STMT_EXPR (t));
12115 if (EXPR_STMT_STMT_EXPR_RESULT (t))
12116 finish_stmt_expr_expr (tmp, cur_stmt_expr);
12118 finish_expr_stmt (tmp);
12122 do_using_directive (USING_STMT_NAMESPACE (t));
12127 tree decl, pattern_decl;
12130 pattern_decl = decl = DECL_EXPR_DECL (t);
12131 if (TREE_CODE (decl) == LABEL_DECL)
12132 finish_label_decl (DECL_NAME (decl));
12133 else if (TREE_CODE (decl) == USING_DECL)
12135 tree scope = USING_DECL_SCOPE (decl);
12136 tree name = DECL_NAME (decl);
12139 scope = tsubst (scope, args, complain, in_decl);
12140 decl = lookup_qualified_name (scope, name,
12141 /*is_type_p=*/false,
12142 /*complain=*/false);
12143 if (decl == error_mark_node || TREE_CODE (decl) == TREE_LIST)
12144 qualified_name_lookup_error (scope, name, decl, input_location);
12146 do_local_using_decl (decl, scope, name);
12150 init = DECL_INITIAL (decl);
12151 decl = tsubst (decl, args, complain, in_decl);
12152 if (decl != error_mark_node)
12154 /* By marking the declaration as instantiated, we avoid
12155 trying to instantiate it. Since instantiate_decl can't
12156 handle local variables, and since we've already done
12157 all that needs to be done, that's the right thing to
12159 if (TREE_CODE (decl) == VAR_DECL)
12160 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
12161 if (TREE_CODE (decl) == VAR_DECL
12162 && ANON_AGGR_TYPE_P (TREE_TYPE (decl)))
12163 /* Anonymous aggregates are a special case. */
12164 finish_anon_union (decl);
12167 int const_init = false;
12168 maybe_push_decl (decl);
12169 if (TREE_CODE (decl) == VAR_DECL
12170 && DECL_PRETTY_FUNCTION_P (decl))
12172 /* For __PRETTY_FUNCTION__ we have to adjust the
12174 const char *const name
12175 = cxx_printable_name (current_function_decl, 2);
12176 init = cp_fname_init (name, &TREE_TYPE (decl));
12180 tree t = RECUR (init);
12184 /* If we had an initializer but it
12185 instantiated to nothing,
12186 value-initialize the object. This will
12187 only occur when the initializer was a
12188 pack expansion where the parameter packs
12189 used in that expansion were of length
12191 init = build_value_init (TREE_TYPE (decl),
12193 if (TREE_CODE (init) == AGGR_INIT_EXPR)
12194 init = get_target_expr_sfinae (init, complain);
12200 if (TREE_CODE (decl) == VAR_DECL)
12201 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
12203 cp_finish_decl (decl, init, const_init, NULL_TREE, 0);
12208 /* A DECL_EXPR can also be used as an expression, in the condition
12209 clause of an if/for/while construct. */
12214 stmt = begin_for_stmt (NULL_TREE, NULL_TREE);
12215 RECUR (FOR_INIT_STMT (t));
12216 finish_for_init_stmt (stmt);
12217 tmp = RECUR (FOR_COND (t));
12218 finish_for_cond (tmp, stmt);
12219 tmp = RECUR (FOR_EXPR (t));
12220 finish_for_expr (tmp, stmt);
12221 RECUR (FOR_BODY (t));
12222 finish_for_stmt (stmt);
12225 case RANGE_FOR_STMT:
12228 stmt = begin_for_stmt (NULL_TREE, NULL_TREE);
12229 decl = RANGE_FOR_DECL (t);
12230 decl = tsubst (decl, args, complain, in_decl);
12231 maybe_push_decl (decl);
12232 expr = RECUR (RANGE_FOR_EXPR (t));
12233 stmt = cp_convert_range_for (stmt, decl, expr);
12234 RECUR (RANGE_FOR_BODY (t));
12235 finish_for_stmt (stmt);
12240 stmt = begin_while_stmt ();
12241 tmp = RECUR (WHILE_COND (t));
12242 finish_while_stmt_cond (tmp, stmt);
12243 RECUR (WHILE_BODY (t));
12244 finish_while_stmt (stmt);
12248 stmt = begin_do_stmt ();
12249 RECUR (DO_BODY (t));
12250 finish_do_body (stmt);
12251 tmp = RECUR (DO_COND (t));
12252 finish_do_stmt (tmp, stmt);
12256 stmt = begin_if_stmt ();
12257 tmp = RECUR (IF_COND (t));
12258 finish_if_stmt_cond (tmp, stmt);
12259 RECUR (THEN_CLAUSE (t));
12260 finish_then_clause (stmt);
12262 if (ELSE_CLAUSE (t))
12264 begin_else_clause (stmt);
12265 RECUR (ELSE_CLAUSE (t));
12266 finish_else_clause (stmt);
12269 finish_if_stmt (stmt);
12273 if (BIND_EXPR_BODY_BLOCK (t))
12274 stmt = begin_function_body ();
12276 stmt = begin_compound_stmt (BIND_EXPR_TRY_BLOCK (t)
12277 ? BCS_TRY_BLOCK : 0);
12279 RECUR (BIND_EXPR_BODY (t));
12281 if (BIND_EXPR_BODY_BLOCK (t))
12282 finish_function_body (stmt);
12284 finish_compound_stmt (stmt);
12288 finish_break_stmt ();
12291 case CONTINUE_STMT:
12292 finish_continue_stmt ();
12296 stmt = begin_switch_stmt ();
12297 tmp = RECUR (SWITCH_STMT_COND (t));
12298 finish_switch_cond (tmp, stmt);
12299 RECUR (SWITCH_STMT_BODY (t));
12300 finish_switch_stmt (stmt);
12303 case CASE_LABEL_EXPR:
12304 finish_case_label (EXPR_LOCATION (t),
12305 RECUR (CASE_LOW (t)),
12306 RECUR (CASE_HIGH (t)));
12311 tree decl = LABEL_EXPR_LABEL (t);
12314 label = finish_label_stmt (DECL_NAME (decl));
12315 if (DECL_ATTRIBUTES (decl) != NULL_TREE)
12316 cplus_decl_attributes (&label, DECL_ATTRIBUTES (decl), 0);
12321 tmp = GOTO_DESTINATION (t);
12322 if (TREE_CODE (tmp) != LABEL_DECL)
12323 /* Computed goto's must be tsubst'd into. On the other hand,
12324 non-computed gotos must not be; the identifier in question
12325 will have no binding. */
12328 tmp = DECL_NAME (tmp);
12329 finish_goto_stmt (tmp);
12333 tmp = finish_asm_stmt
12334 (ASM_VOLATILE_P (t),
12335 RECUR (ASM_STRING (t)),
12336 tsubst_copy_asm_operands (ASM_OUTPUTS (t), args, complain, in_decl),
12337 tsubst_copy_asm_operands (ASM_INPUTS (t), args, complain, in_decl),
12338 tsubst_copy_asm_operands (ASM_CLOBBERS (t), args, complain, in_decl),
12339 tsubst_copy_asm_operands (ASM_LABELS (t), args, complain, in_decl));
12341 tree asm_expr = tmp;
12342 if (TREE_CODE (asm_expr) == CLEANUP_POINT_EXPR)
12343 asm_expr = TREE_OPERAND (asm_expr, 0);
12344 ASM_INPUT_P (asm_expr) = ASM_INPUT_P (t);
12351 stmt = begin_try_block ();
12352 RECUR (TRY_STMTS (t));
12353 finish_cleanup_try_block (stmt);
12354 finish_cleanup (RECUR (TRY_HANDLERS (t)), stmt);
12358 tree compound_stmt = NULL_TREE;
12360 if (FN_TRY_BLOCK_P (t))
12361 stmt = begin_function_try_block (&compound_stmt);
12363 stmt = begin_try_block ();
12365 RECUR (TRY_STMTS (t));
12367 if (FN_TRY_BLOCK_P (t))
12368 finish_function_try_block (stmt);
12370 finish_try_block (stmt);
12372 RECUR (TRY_HANDLERS (t));
12373 if (FN_TRY_BLOCK_P (t))
12374 finish_function_handler_sequence (stmt, compound_stmt);
12376 finish_handler_sequence (stmt);
12382 tree decl = HANDLER_PARMS (t);
12386 decl = tsubst (decl, args, complain, in_decl);
12387 /* Prevent instantiate_decl from trying to instantiate
12388 this variable. We've already done all that needs to be
12390 if (decl != error_mark_node)
12391 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
12393 stmt = begin_handler ();
12394 finish_handler_parms (decl, stmt);
12395 RECUR (HANDLER_BODY (t));
12396 finish_handler (stmt);
12401 tsubst (TREE_TYPE (t), args, complain, NULL_TREE);
12404 case STATIC_ASSERT:
12407 tsubst_expr (STATIC_ASSERT_CONDITION (t),
12410 /*integral_constant_expression_p=*/true);
12411 finish_static_assert (condition,
12412 STATIC_ASSERT_MESSAGE (t),
12413 STATIC_ASSERT_SOURCE_LOCATION (t),
12414 /*member_p=*/false);
12419 tmp = tsubst_omp_clauses (OMP_PARALLEL_CLAUSES (t),
12420 args, complain, in_decl);
12421 stmt = begin_omp_parallel ();
12422 RECUR (OMP_PARALLEL_BODY (t));
12423 OMP_PARALLEL_COMBINED (finish_omp_parallel (tmp, stmt))
12424 = OMP_PARALLEL_COMBINED (t);
12428 tmp = tsubst_omp_clauses (OMP_TASK_CLAUSES (t),
12429 args, complain, in_decl);
12430 stmt = begin_omp_task ();
12431 RECUR (OMP_TASK_BODY (t));
12432 finish_omp_task (tmp, stmt);
12437 tree clauses, body, pre_body;
12438 tree declv, initv, condv, incrv;
12441 clauses = tsubst_omp_clauses (OMP_FOR_CLAUSES (t),
12442 args, complain, in_decl);
12443 declv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
12444 initv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
12445 condv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
12446 incrv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
12448 for (i = 0; i < TREE_VEC_LENGTH (OMP_FOR_INIT (t)); i++)
12449 tsubst_omp_for_iterator (t, i, declv, initv, condv, incrv,
12450 &clauses, args, complain, in_decl,
12451 integral_constant_expression_p);
12453 stmt = begin_omp_structured_block ();
12455 for (i = 0; i < TREE_VEC_LENGTH (initv); i++)
12456 if (TREE_VEC_ELT (initv, i) == NULL
12457 || TREE_CODE (TREE_VEC_ELT (initv, i)) != DECL_EXPR)
12458 TREE_VEC_ELT (initv, i) = RECUR (TREE_VEC_ELT (initv, i));
12459 else if (CLASS_TYPE_P (TREE_TYPE (TREE_VEC_ELT (initv, i))))
12461 tree init = RECUR (TREE_VEC_ELT (initv, i));
12462 gcc_assert (init == TREE_VEC_ELT (declv, i));
12463 TREE_VEC_ELT (initv, i) = NULL_TREE;
12467 tree decl_expr = TREE_VEC_ELT (initv, i);
12468 tree init = DECL_INITIAL (DECL_EXPR_DECL (decl_expr));
12469 gcc_assert (init != NULL);
12470 TREE_VEC_ELT (initv, i) = RECUR (init);
12471 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = NULL;
12473 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = init;
12476 pre_body = push_stmt_list ();
12477 RECUR (OMP_FOR_PRE_BODY (t));
12478 pre_body = pop_stmt_list (pre_body);
12480 body = push_stmt_list ();
12481 RECUR (OMP_FOR_BODY (t));
12482 body = pop_stmt_list (body);
12484 t = finish_omp_for (EXPR_LOCATION (t), declv, initv, condv, incrv,
12485 body, pre_body, clauses);
12487 add_stmt (finish_omp_structured_block (stmt));
12493 tmp = tsubst_omp_clauses (OMP_CLAUSES (t), args, complain, in_decl);
12494 stmt = push_stmt_list ();
12495 RECUR (OMP_BODY (t));
12496 stmt = pop_stmt_list (stmt);
12499 OMP_BODY (t) = stmt;
12500 OMP_CLAUSES (t) = tmp;
12508 stmt = push_stmt_list ();
12509 RECUR (OMP_BODY (t));
12510 stmt = pop_stmt_list (stmt);
12513 OMP_BODY (t) = stmt;
12518 gcc_assert (OMP_ATOMIC_DEPENDENT_P (t));
12520 tree op1 = TREE_OPERAND (t, 1);
12521 tree lhs = RECUR (TREE_OPERAND (op1, 0));
12522 tree rhs = RECUR (TREE_OPERAND (op1, 1));
12523 finish_omp_atomic (TREE_CODE (op1), lhs, rhs);
12527 case EXPR_PACK_EXPANSION:
12528 error ("invalid use of pack expansion expression");
12529 return error_mark_node;
12531 case NONTYPE_ARGUMENT_PACK:
12532 error ("use %<...%> to expand argument pack");
12533 return error_mark_node;
12536 gcc_assert (!STATEMENT_CODE_P (TREE_CODE (t)));
12538 return tsubst_copy_and_build (t, args, complain, in_decl,
12539 /*function_p=*/false,
12540 integral_constant_expression_p);
12547 /* T is a postfix-expression that is not being used in a function
12548 call. Return the substituted version of T. */
12551 tsubst_non_call_postfix_expression (tree t, tree args,
12552 tsubst_flags_t complain,
12555 if (TREE_CODE (t) == SCOPE_REF)
12556 t = tsubst_qualified_id (t, args, complain, in_decl,
12557 /*done=*/false, /*address_p=*/false);
12559 t = tsubst_copy_and_build (t, args, complain, in_decl,
12560 /*function_p=*/false,
12561 /*integral_constant_expression_p=*/false);
12566 /* Like tsubst but deals with expressions and performs semantic
12567 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
12570 tsubst_copy_and_build (tree t,
12572 tsubst_flags_t complain,
12575 bool integral_constant_expression_p)
12577 #define RECUR(NODE) \
12578 tsubst_copy_and_build (NODE, args, complain, in_decl, \
12579 /*function_p=*/false, \
12580 integral_constant_expression_p)
12584 if (t == NULL_TREE || t == error_mark_node)
12587 switch (TREE_CODE (t))
12591 /* Fall through. */
12592 case IDENTIFIER_NODE:
12596 bool non_integral_constant_expression_p;
12597 const char *error_msg;
12599 if (IDENTIFIER_TYPENAME_P (t))
12601 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12602 t = mangle_conv_op_name_for_type (new_type);
12605 /* Look up the name. */
12606 decl = lookup_name (t);
12608 /* By convention, expressions use ERROR_MARK_NODE to indicate
12609 failure, not NULL_TREE. */
12610 if (decl == NULL_TREE)
12611 decl = error_mark_node;
12613 decl = finish_id_expression (t, decl, NULL_TREE,
12615 integral_constant_expression_p,
12616 /*allow_non_integral_constant_expression_p=*/false,
12617 &non_integral_constant_expression_p,
12618 /*template_p=*/false,
12620 /*address_p=*/false,
12621 /*template_arg_p=*/false,
12626 if (!function_p && TREE_CODE (decl) == IDENTIFIER_NODE)
12627 decl = unqualified_name_lookup_error (decl);
12631 case TEMPLATE_ID_EXPR:
12634 tree templ = RECUR (TREE_OPERAND (t, 0));
12635 tree targs = TREE_OPERAND (t, 1);
12638 targs = tsubst_template_args (targs, args, complain, in_decl);
12640 if (TREE_CODE (templ) == COMPONENT_REF)
12642 object = TREE_OPERAND (templ, 0);
12643 templ = TREE_OPERAND (templ, 1);
12646 object = NULL_TREE;
12647 templ = lookup_template_function (templ, targs);
12650 return build3 (COMPONENT_REF, TREE_TYPE (templ),
12651 object, templ, NULL_TREE);
12653 return baselink_for_fns (templ);
12658 tree r = RECUR (TREE_OPERAND (t, 0));
12660 if (REFERENCE_REF_P (t))
12662 /* A type conversion to reference type will be enclosed in
12663 such an indirect ref, but the substitution of the cast
12664 will have also added such an indirect ref. */
12665 if (TREE_CODE (TREE_TYPE (r)) == REFERENCE_TYPE)
12666 r = convert_from_reference (r);
12669 r = build_x_indirect_ref (r, RO_UNARY_STAR, complain);
12675 (tsubst (TREE_TYPE (t), args, complain, in_decl),
12676 RECUR (TREE_OPERAND (t, 0)));
12679 case REINTERPRET_CAST_EXPR:
12680 case CONST_CAST_EXPR:
12681 case DYNAMIC_CAST_EXPR:
12682 case STATIC_CAST_EXPR:
12687 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12688 if (integral_constant_expression_p
12689 && !cast_valid_in_integral_constant_expression_p (type))
12691 if (complain & tf_error)
12692 error ("a cast to a type other than an integral or "
12693 "enumeration type cannot appear in a constant-expression");
12694 return error_mark_node;
12697 op = RECUR (TREE_OPERAND (t, 0));
12699 switch (TREE_CODE (t))
12702 return build_functional_cast (type, op, complain);
12703 case REINTERPRET_CAST_EXPR:
12704 return build_reinterpret_cast (type, op, complain);
12705 case CONST_CAST_EXPR:
12706 return build_const_cast (type, op, complain);
12707 case DYNAMIC_CAST_EXPR:
12708 return build_dynamic_cast (type, op, complain);
12709 case STATIC_CAST_EXPR:
12710 return build_static_cast (type, op, complain);
12712 gcc_unreachable ();
12716 case POSTDECREMENT_EXPR:
12717 case POSTINCREMENT_EXPR:
12718 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
12719 args, complain, in_decl);
12720 return build_x_unary_op (TREE_CODE (t), op1, complain);
12722 case PREDECREMENT_EXPR:
12723 case PREINCREMENT_EXPR:
12727 case TRUTH_NOT_EXPR:
12728 case UNARY_PLUS_EXPR: /* Unary + */
12729 case REALPART_EXPR:
12730 case IMAGPART_EXPR:
12731 return build_x_unary_op (TREE_CODE (t), RECUR (TREE_OPERAND (t, 0)),
12735 op1 = TREE_OPERAND (t, 0);
12736 if (TREE_CODE (op1) == LABEL_DECL)
12737 return finish_label_address_expr (DECL_NAME (op1),
12738 EXPR_LOCATION (op1));
12739 if (TREE_CODE (op1) == SCOPE_REF)
12740 op1 = tsubst_qualified_id (op1, args, complain, in_decl,
12741 /*done=*/true, /*address_p=*/true);
12743 op1 = tsubst_non_call_postfix_expression (op1, args, complain,
12745 return build_x_unary_op (ADDR_EXPR, op1, complain);
12750 case TRUNC_DIV_EXPR:
12751 case CEIL_DIV_EXPR:
12752 case FLOOR_DIV_EXPR:
12753 case ROUND_DIV_EXPR:
12754 case EXACT_DIV_EXPR:
12758 case TRUNC_MOD_EXPR:
12759 case FLOOR_MOD_EXPR:
12760 case TRUTH_ANDIF_EXPR:
12761 case TRUTH_ORIF_EXPR:
12762 case TRUTH_AND_EXPR:
12763 case TRUTH_OR_EXPR:
12778 return build_x_binary_op
12780 RECUR (TREE_OPERAND (t, 0)),
12781 (TREE_NO_WARNING (TREE_OPERAND (t, 0))
12783 : TREE_CODE (TREE_OPERAND (t, 0))),
12784 RECUR (TREE_OPERAND (t, 1)),
12785 (TREE_NO_WARNING (TREE_OPERAND (t, 1))
12787 : TREE_CODE (TREE_OPERAND (t, 1))),
12792 return tsubst_qualified_id (t, args, complain, in_decl, /*done=*/true,
12793 /*address_p=*/false);
12795 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
12796 args, complain, in_decl);
12797 return build_x_array_ref (op1, RECUR (TREE_OPERAND (t, 1)), complain);
12800 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
12801 return tsubst_copy (t, args, complain, in_decl);
12805 op1 = TREE_OPERAND (t, 0);
12808 /* When there are no ARGS, we are trying to evaluate a
12809 non-dependent expression from the parser. Trying to do
12810 the substitutions may not work. */
12812 op1 = TREE_TYPE (op1);
12816 ++cp_unevaluated_operand;
12817 ++c_inhibit_evaluation_warnings;
12818 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
12819 /*function_p=*/false,
12820 /*integral_constant_expression_p=*/false);
12821 --cp_unevaluated_operand;
12822 --c_inhibit_evaluation_warnings;
12825 return cxx_sizeof_or_alignof_type (op1, TREE_CODE (t),
12826 complain & tf_error);
12828 return cxx_sizeof_or_alignof_expr (op1, TREE_CODE (t),
12829 complain & tf_error);
12831 case AT_ENCODE_EXPR:
12833 op1 = TREE_OPERAND (t, 0);
12834 ++cp_unevaluated_operand;
12835 ++c_inhibit_evaluation_warnings;
12836 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
12837 /*function_p=*/false,
12838 /*integral_constant_expression_p=*/false);
12839 --cp_unevaluated_operand;
12840 --c_inhibit_evaluation_warnings;
12841 return objc_build_encode_expr (op1);
12844 case NOEXCEPT_EXPR:
12845 op1 = TREE_OPERAND (t, 0);
12846 ++cp_unevaluated_operand;
12847 ++c_inhibit_evaluation_warnings;
12848 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
12849 /*function_p=*/false,
12850 /*integral_constant_expression_p=*/false);
12851 --cp_unevaluated_operand;
12852 --c_inhibit_evaluation_warnings;
12853 return finish_noexcept_expr (op1, complain);
12857 tree r = build_x_modify_expr
12858 (RECUR (TREE_OPERAND (t, 0)),
12859 TREE_CODE (TREE_OPERAND (t, 1)),
12860 RECUR (TREE_OPERAND (t, 2)),
12862 /* TREE_NO_WARNING must be set if either the expression was
12863 parenthesized or it uses an operator such as >>= rather
12864 than plain assignment. In the former case, it was already
12865 set and must be copied. In the latter case,
12866 build_x_modify_expr sets it and it must not be reset
12868 if (TREE_NO_WARNING (t))
12869 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
12874 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
12875 args, complain, in_decl);
12876 /* Remember that there was a reference to this entity. */
12879 return build_x_arrow (op1);
12883 tree placement = RECUR (TREE_OPERAND (t, 0));
12884 tree init = RECUR (TREE_OPERAND (t, 3));
12885 VEC(tree,gc) *placement_vec;
12886 VEC(tree,gc) *init_vec;
12889 if (placement == NULL_TREE)
12890 placement_vec = NULL;
12893 placement_vec = make_tree_vector ();
12894 for (; placement != NULL_TREE; placement = TREE_CHAIN (placement))
12895 VEC_safe_push (tree, gc, placement_vec, TREE_VALUE (placement));
12898 /* If there was an initializer in the original tree, but it
12899 instantiated to an empty list, then we should pass a
12900 non-NULL empty vector to tell build_new that it was an
12901 empty initializer() rather than no initializer. This can
12902 only happen when the initializer is a pack expansion whose
12903 parameter packs are of length zero. */
12904 if (init == NULL_TREE && TREE_OPERAND (t, 3) == NULL_TREE)
12908 init_vec = make_tree_vector ();
12909 if (init == void_zero_node)
12910 gcc_assert (init_vec != NULL);
12913 for (; init != NULL_TREE; init = TREE_CHAIN (init))
12914 VEC_safe_push (tree, gc, init_vec, TREE_VALUE (init));
12918 ret = build_new (&placement_vec,
12919 tsubst (TREE_OPERAND (t, 1), args, complain, in_decl),
12920 RECUR (TREE_OPERAND (t, 2)),
12922 NEW_EXPR_USE_GLOBAL (t),
12925 if (placement_vec != NULL)
12926 release_tree_vector (placement_vec);
12927 if (init_vec != NULL)
12928 release_tree_vector (init_vec);
12934 return delete_sanity
12935 (RECUR (TREE_OPERAND (t, 0)),
12936 RECUR (TREE_OPERAND (t, 1)),
12937 DELETE_EXPR_USE_VEC (t),
12938 DELETE_EXPR_USE_GLOBAL (t),
12941 case COMPOUND_EXPR:
12942 return build_x_compound_expr (RECUR (TREE_OPERAND (t, 0)),
12943 RECUR (TREE_OPERAND (t, 1)),
12949 VEC(tree,gc) *call_args;
12950 unsigned int nargs, i;
12955 function = CALL_EXPR_FN (t);
12956 /* When we parsed the expression, we determined whether or
12957 not Koenig lookup should be performed. */
12958 koenig_p = KOENIG_LOOKUP_P (t);
12959 if (TREE_CODE (function) == SCOPE_REF)
12961 qualified_p = true;
12962 function = tsubst_qualified_id (function, args, complain, in_decl,
12964 /*address_p=*/false);
12966 else if (koenig_p && TREE_CODE (function) == IDENTIFIER_NODE)
12968 /* Do nothing; calling tsubst_copy_and_build on an identifier
12969 would incorrectly perform unqualified lookup again.
12971 Note that we can also have an IDENTIFIER_NODE if the earlier
12972 unqualified lookup found a member function; in that case
12973 koenig_p will be false and we do want to do the lookup
12974 again to find the instantiated member function.
12976 FIXME but doing that causes c++/15272, so we need to stop
12977 using IDENTIFIER_NODE in that situation. */
12978 qualified_p = false;
12982 if (TREE_CODE (function) == COMPONENT_REF)
12984 tree op = TREE_OPERAND (function, 1);
12986 qualified_p = (TREE_CODE (op) == SCOPE_REF
12987 || (BASELINK_P (op)
12988 && BASELINK_QUALIFIED_P (op)));
12991 qualified_p = false;
12993 function = tsubst_copy_and_build (function, args, complain,
12996 integral_constant_expression_p);
12998 if (BASELINK_P (function))
12999 qualified_p = true;
13002 nargs = call_expr_nargs (t);
13003 call_args = make_tree_vector ();
13004 for (i = 0; i < nargs; ++i)
13006 tree arg = CALL_EXPR_ARG (t, i);
13008 if (!PACK_EXPANSION_P (arg))
13009 VEC_safe_push (tree, gc, call_args,
13010 RECUR (CALL_EXPR_ARG (t, i)));
13013 /* Expand the pack expansion and push each entry onto
13015 arg = tsubst_pack_expansion (arg, args, complain, in_decl);
13016 if (TREE_CODE (arg) == TREE_VEC)
13018 unsigned int len, j;
13020 len = TREE_VEC_LENGTH (arg);
13021 for (j = 0; j < len; ++j)
13023 tree value = TREE_VEC_ELT (arg, j);
13024 if (value != NULL_TREE)
13025 value = convert_from_reference (value);
13026 VEC_safe_push (tree, gc, call_args, value);
13031 /* A partial substitution. Add one entry. */
13032 VEC_safe_push (tree, gc, call_args, arg);
13037 /* We do not perform argument-dependent lookup if normal
13038 lookup finds a non-function, in accordance with the
13039 expected resolution of DR 218. */
13041 && ((is_overloaded_fn (function)
13042 /* If lookup found a member function, the Koenig lookup is
13043 not appropriate, even if an unqualified-name was used
13044 to denote the function. */
13045 && !DECL_FUNCTION_MEMBER_P (get_first_fn (function)))
13046 || TREE_CODE (function) == IDENTIFIER_NODE)
13047 /* Only do this when substitution turns a dependent call
13048 into a non-dependent call. */
13049 && type_dependent_expression_p_push (t)
13050 && !any_type_dependent_arguments_p (call_args))
13051 function = perform_koenig_lookup (function, call_args, false,
13054 if (TREE_CODE (function) == IDENTIFIER_NODE
13055 && !any_type_dependent_arguments_p (call_args))
13057 if (koenig_p && (complain & tf_warning_or_error))
13059 /* For backwards compatibility and good diagnostics, try
13060 the unqualified lookup again if we aren't in SFINAE
13062 tree unq = (tsubst_copy_and_build
13063 (function, args, complain, in_decl, true,
13064 integral_constant_expression_p));
13065 if (unq != function)
13068 if (TREE_CODE (fn) == COMPONENT_REF)
13069 fn = TREE_OPERAND (fn, 1);
13070 if (is_overloaded_fn (fn))
13071 fn = get_first_fn (fn);
13072 permerror (EXPR_LOC_OR_HERE (t),
13073 "%qD was not declared in this scope, "
13074 "and no declarations were found by "
13075 "argument-dependent lookup at the point "
13076 "of instantiation", function);
13077 if (DECL_CLASS_SCOPE_P (fn))
13079 inform (EXPR_LOC_OR_HERE (t),
13080 "declarations in dependent base %qT are "
13081 "not found by unqualified lookup",
13082 DECL_CLASS_CONTEXT (fn));
13083 if (current_class_ptr)
13084 inform (EXPR_LOC_OR_HERE (t),
13085 "use %<this->%D%> instead", function);
13087 inform (EXPR_LOC_OR_HERE (t),
13088 "use %<%T::%D%> instead",
13089 current_class_name, function);
13092 inform (0, "%q+D declared here, later in the "
13093 "translation unit", fn);
13097 if (TREE_CODE (function) == IDENTIFIER_NODE)
13099 unqualified_name_lookup_error (function);
13100 release_tree_vector (call_args);
13101 return error_mark_node;
13105 /* Remember that there was a reference to this entity. */
13106 if (DECL_P (function))
13107 mark_used (function);
13109 if (TREE_CODE (function) == OFFSET_REF)
13110 ret = build_offset_ref_call_from_tree (function, &call_args);
13111 else if (TREE_CODE (function) == COMPONENT_REF)
13113 tree instance = TREE_OPERAND (function, 0);
13114 tree fn = TREE_OPERAND (function, 1);
13116 if (processing_template_decl
13117 && (type_dependent_expression_p (instance)
13118 || (!BASELINK_P (fn)
13119 && TREE_CODE (fn) != FIELD_DECL)
13120 || type_dependent_expression_p (fn)
13121 || any_type_dependent_arguments_p (call_args)))
13122 ret = build_nt_call_vec (function, call_args);
13123 else if (!BASELINK_P (fn))
13124 ret = finish_call_expr (function, &call_args,
13125 /*disallow_virtual=*/false,
13126 /*koenig_p=*/false,
13129 ret = (build_new_method_call
13131 &call_args, NULL_TREE,
13132 qualified_p ? LOOKUP_NONVIRTUAL : LOOKUP_NORMAL,
13137 ret = finish_call_expr (function, &call_args,
13138 /*disallow_virtual=*/qualified_p,
13142 release_tree_vector (call_args);
13148 return build_x_conditional_expr
13149 (RECUR (TREE_OPERAND (t, 0)),
13150 RECUR (TREE_OPERAND (t, 1)),
13151 RECUR (TREE_OPERAND (t, 2)),
13154 case PSEUDO_DTOR_EXPR:
13155 return finish_pseudo_destructor_expr
13156 (RECUR (TREE_OPERAND (t, 0)),
13157 RECUR (TREE_OPERAND (t, 1)),
13158 tsubst (TREE_OPERAND (t, 2), args, complain, in_decl));
13162 tree purpose, value, chain;
13164 if (t == void_list_node)
13167 if ((TREE_PURPOSE (t) && PACK_EXPANSION_P (TREE_PURPOSE (t)))
13168 || (TREE_VALUE (t) && PACK_EXPANSION_P (TREE_VALUE (t))))
13170 /* We have pack expansions, so expand those and
13171 create a new list out of it. */
13172 tree purposevec = NULL_TREE;
13173 tree valuevec = NULL_TREE;
13177 /* Expand the argument expressions. */
13178 if (TREE_PURPOSE (t))
13179 purposevec = tsubst_pack_expansion (TREE_PURPOSE (t), args,
13180 complain, in_decl);
13181 if (TREE_VALUE (t))
13182 valuevec = tsubst_pack_expansion (TREE_VALUE (t), args,
13183 complain, in_decl);
13185 /* Build the rest of the list. */
13186 chain = TREE_CHAIN (t);
13187 if (chain && chain != void_type_node)
13188 chain = RECUR (chain);
13190 /* Determine the number of arguments. */
13191 if (purposevec && TREE_CODE (purposevec) == TREE_VEC)
13193 len = TREE_VEC_LENGTH (purposevec);
13194 gcc_assert (!valuevec || len == TREE_VEC_LENGTH (valuevec));
13196 else if (TREE_CODE (valuevec) == TREE_VEC)
13197 len = TREE_VEC_LENGTH (valuevec);
13200 /* Since we only performed a partial substitution into
13201 the argument pack, we only return a single list
13203 if (purposevec == TREE_PURPOSE (t)
13204 && valuevec == TREE_VALUE (t)
13205 && chain == TREE_CHAIN (t))
13208 return tree_cons (purposevec, valuevec, chain);
13211 /* Convert the argument vectors into a TREE_LIST */
13215 /* Grab the Ith values. */
13217 purpose = purposevec ? TREE_VEC_ELT (purposevec, i)
13220 = valuevec ? convert_from_reference (TREE_VEC_ELT (valuevec, i))
13223 /* Build the list (backwards). */
13224 chain = tree_cons (purpose, value, chain);
13230 purpose = TREE_PURPOSE (t);
13232 purpose = RECUR (purpose);
13233 value = TREE_VALUE (t);
13235 value = RECUR (value);
13236 chain = TREE_CHAIN (t);
13237 if (chain && chain != void_type_node)
13238 chain = RECUR (chain);
13239 if (purpose == TREE_PURPOSE (t)
13240 && value == TREE_VALUE (t)
13241 && chain == TREE_CHAIN (t))
13243 return tree_cons (purpose, value, chain);
13246 case COMPONENT_REF:
13252 object = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
13253 args, complain, in_decl);
13254 /* Remember that there was a reference to this entity. */
13255 if (DECL_P (object))
13256 mark_used (object);
13257 object_type = TREE_TYPE (object);
13259 member = TREE_OPERAND (t, 1);
13260 if (BASELINK_P (member))
13261 member = tsubst_baselink (member,
13262 non_reference (TREE_TYPE (object)),
13263 args, complain, in_decl);
13265 member = tsubst_copy (member, args, complain, in_decl);
13266 if (member == error_mark_node)
13267 return error_mark_node;
13269 if (object_type && !CLASS_TYPE_P (object_type))
13271 if (SCALAR_TYPE_P (object_type))
13273 tree s = NULL_TREE;
13274 tree dtor = member;
13276 if (TREE_CODE (dtor) == SCOPE_REF)
13278 s = TREE_OPERAND (dtor, 0);
13279 dtor = TREE_OPERAND (dtor, 1);
13281 if (TREE_CODE (dtor) == BIT_NOT_EXPR)
13283 dtor = TREE_OPERAND (dtor, 0);
13285 return finish_pseudo_destructor_expr (object, s, dtor);
13289 else if (TREE_CODE (member) == SCOPE_REF
13290 && TREE_CODE (TREE_OPERAND (member, 1)) == TEMPLATE_ID_EXPR)
13295 /* Lookup the template functions now that we know what the
13297 tmpl = TREE_OPERAND (TREE_OPERAND (member, 1), 0);
13298 args = TREE_OPERAND (TREE_OPERAND (member, 1), 1);
13299 member = lookup_qualified_name (TREE_OPERAND (member, 0), tmpl,
13300 /*is_type_p=*/false,
13301 /*complain=*/false);
13302 if (BASELINK_P (member))
13304 BASELINK_FUNCTIONS (member)
13305 = build_nt (TEMPLATE_ID_EXPR, BASELINK_FUNCTIONS (member),
13307 member = (adjust_result_of_qualified_name_lookup
13308 (member, BINFO_TYPE (BASELINK_BINFO (member)),
13313 qualified_name_lookup_error (object_type, tmpl, member,
13315 return error_mark_node;
13318 else if (TREE_CODE (member) == SCOPE_REF
13319 && !CLASS_TYPE_P (TREE_OPERAND (member, 0))
13320 && TREE_CODE (TREE_OPERAND (member, 0)) != NAMESPACE_DECL)
13322 if (complain & tf_error)
13324 if (TYPE_P (TREE_OPERAND (member, 0)))
13325 error ("%qT is not a class or namespace",
13326 TREE_OPERAND (member, 0));
13328 error ("%qD is not a class or namespace",
13329 TREE_OPERAND (member, 0));
13331 return error_mark_node;
13333 else if (TREE_CODE (member) == FIELD_DECL)
13334 return finish_non_static_data_member (member, object, NULL_TREE);
13336 return finish_class_member_access_expr (object, member,
13337 /*template_p=*/false,
13343 (RECUR (TREE_OPERAND (t, 0)));
13347 VEC(constructor_elt,gc) *n;
13348 constructor_elt *ce;
13349 unsigned HOST_WIDE_INT idx;
13350 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
13351 bool process_index_p;
13353 bool need_copy_p = false;
13356 if (type == error_mark_node)
13357 return error_mark_node;
13359 /* digest_init will do the wrong thing if we let it. */
13360 if (type && TYPE_PTRMEMFUNC_P (type))
13363 /* We do not want to process the index of aggregate
13364 initializers as they are identifier nodes which will be
13365 looked up by digest_init. */
13366 process_index_p = !(type && MAYBE_CLASS_TYPE_P (type));
13368 n = VEC_copy (constructor_elt, gc, CONSTRUCTOR_ELTS (t));
13369 newlen = VEC_length (constructor_elt, n);
13370 FOR_EACH_VEC_ELT (constructor_elt, n, idx, ce)
13372 if (ce->index && process_index_p)
13373 ce->index = RECUR (ce->index);
13375 if (PACK_EXPANSION_P (ce->value))
13377 /* Substitute into the pack expansion. */
13378 ce->value = tsubst_pack_expansion (ce->value, args, complain,
13381 if (ce->value == error_mark_node
13382 || PACK_EXPANSION_P (ce->value))
13384 else if (TREE_VEC_LENGTH (ce->value) == 1)
13385 /* Just move the argument into place. */
13386 ce->value = TREE_VEC_ELT (ce->value, 0);
13389 /* Update the length of the final CONSTRUCTOR
13390 arguments vector, and note that we will need to
13392 newlen = newlen + TREE_VEC_LENGTH (ce->value) - 1;
13393 need_copy_p = true;
13397 ce->value = RECUR (ce->value);
13402 VEC(constructor_elt,gc) *old_n = n;
13404 n = VEC_alloc (constructor_elt, gc, newlen);
13405 FOR_EACH_VEC_ELT (constructor_elt, old_n, idx, ce)
13407 if (TREE_CODE (ce->value) == TREE_VEC)
13409 int i, len = TREE_VEC_LENGTH (ce->value);
13410 for (i = 0; i < len; ++i)
13411 CONSTRUCTOR_APPEND_ELT (n, 0,
13412 TREE_VEC_ELT (ce->value, i));
13415 CONSTRUCTOR_APPEND_ELT (n, 0, ce->value);
13419 r = build_constructor (init_list_type_node, n);
13420 CONSTRUCTOR_IS_DIRECT_INIT (r) = CONSTRUCTOR_IS_DIRECT_INIT (t);
13422 if (TREE_HAS_CONSTRUCTOR (t))
13423 return finish_compound_literal (type, r, complain);
13425 TREE_TYPE (r) = type;
13431 tree operand_0 = TREE_OPERAND (t, 0);
13432 if (TYPE_P (operand_0))
13434 operand_0 = tsubst (operand_0, args, complain, in_decl);
13435 return get_typeid (operand_0);
13439 operand_0 = RECUR (operand_0);
13440 return build_typeid (operand_0);
13451 tree r = tsubst_copy (t, args, complain, in_decl);
13453 if (TREE_CODE (TREE_TYPE (t)) != REFERENCE_TYPE)
13454 /* If the original type was a reference, we'll be wrapped in
13455 the appropriate INDIRECT_REF. */
13456 r = convert_from_reference (r);
13461 return build_x_va_arg (RECUR (TREE_OPERAND (t, 0)),
13462 tsubst (TREE_TYPE (t), args, complain, in_decl));
13464 case OFFSETOF_EXPR:
13465 return finish_offsetof (RECUR (TREE_OPERAND (t, 0)));
13469 tree type1 = tsubst_copy (TRAIT_EXPR_TYPE1 (t), args,
13470 complain, in_decl);
13472 tree type2 = TRAIT_EXPR_TYPE2 (t);
13474 type2 = tsubst_copy (type2, args, complain, in_decl);
13476 return finish_trait_expr (TRAIT_EXPR_KIND (t), type1, type2);
13481 tree old_stmt_expr = cur_stmt_expr;
13482 tree stmt_expr = begin_stmt_expr ();
13484 cur_stmt_expr = stmt_expr;
13485 tsubst_expr (STMT_EXPR_STMT (t), args, complain, in_decl,
13486 integral_constant_expression_p);
13487 stmt_expr = finish_stmt_expr (stmt_expr, false);
13488 cur_stmt_expr = old_stmt_expr;
13490 /* If the resulting list of expression statement is empty,
13491 fold it further into void_zero_node. */
13492 if (empty_expr_stmt_p (stmt_expr))
13493 stmt_expr = void_zero_node;
13499 t = tsubst_copy (t, args, complain, in_decl);
13500 /* As in finish_id_expression, we resolve enumeration constants
13501 to their underlying values. */
13502 if (TREE_CODE (t) == CONST_DECL)
13504 used_types_insert (TREE_TYPE (t));
13505 return DECL_INITIAL (t);
13511 tree r = build_lambda_expr ();
13513 tree type = tsubst (TREE_TYPE (t), args, complain, NULL_TREE);
13514 TREE_TYPE (r) = type;
13515 CLASSTYPE_LAMBDA_EXPR (type) = r;
13517 LAMBDA_EXPR_LOCATION (r)
13518 = LAMBDA_EXPR_LOCATION (t);
13519 LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (r)
13520 = LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (t);
13521 LAMBDA_EXPR_MUTABLE_P (r) = LAMBDA_EXPR_MUTABLE_P (t);
13522 LAMBDA_EXPR_DISCRIMINATOR (r)
13523 = (LAMBDA_EXPR_DISCRIMINATOR (t));
13524 LAMBDA_EXPR_CAPTURE_LIST (r)
13525 = RECUR (LAMBDA_EXPR_CAPTURE_LIST (t));
13526 LAMBDA_EXPR_EXTRA_SCOPE (r)
13527 = RECUR (LAMBDA_EXPR_EXTRA_SCOPE (t));
13528 gcc_assert (LAMBDA_EXPR_THIS_CAPTURE (t) == NULL_TREE
13529 && LAMBDA_EXPR_PENDING_PROXIES (t) == NULL);
13531 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
13532 determine_visibility (TYPE_NAME (type));
13533 /* Now that we know visibility, instantiate the type so we have a
13534 declaration of the op() for later calls to lambda_function. */
13535 complete_type (type);
13537 type = tsubst (LAMBDA_EXPR_RETURN_TYPE (t), args, complain, in_decl);
13539 apply_lambda_return_type (r, type);
13541 return build_lambda_object (r);
13545 /* We can get here for a constant initializer of non-dependent type.
13546 FIXME stop folding in cp_parser_initializer_clause. */
13547 gcc_assert (TREE_CONSTANT (t));
13549 tree r = get_target_expr (RECUR (TARGET_EXPR_INITIAL (t)));
13550 TREE_CONSTANT (r) = true;
13555 /* Handle Objective-C++ constructs, if appropriate. */
13558 = objcp_tsubst_copy_and_build (t, args, complain,
13559 in_decl, /*function_p=*/false);
13563 return tsubst_copy (t, args, complain, in_decl);
13569 /* Verify that the instantiated ARGS are valid. For type arguments,
13570 make sure that the type's linkage is ok. For non-type arguments,
13571 make sure they are constants if they are integral or enumerations.
13572 Emit an error under control of COMPLAIN, and return TRUE on error. */
13575 check_instantiated_arg (tree tmpl, tree t, tsubst_flags_t complain)
13577 if (ARGUMENT_PACK_P (t))
13579 tree vec = ARGUMENT_PACK_ARGS (t);
13580 int len = TREE_VEC_LENGTH (vec);
13581 bool result = false;
13584 for (i = 0; i < len; ++i)
13585 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (vec, i), complain))
13589 else if (TYPE_P (t))
13591 /* [basic.link]: A name with no linkage (notably, the name
13592 of a class or enumeration declared in a local scope)
13593 shall not be used to declare an entity with linkage.
13594 This implies that names with no linkage cannot be used as
13597 DR 757 relaxes this restriction for C++0x. */
13598 tree nt = (cxx_dialect > cxx98 ? NULL_TREE
13599 : no_linkage_check (t, /*relaxed_p=*/false));
13603 /* DR 488 makes use of a type with no linkage cause
13604 type deduction to fail. */
13605 if (complain & tf_error)
13607 if (TYPE_ANONYMOUS_P (nt))
13608 error ("%qT is/uses anonymous type", t);
13610 error ("template argument for %qD uses local type %qT",
13615 /* In order to avoid all sorts of complications, we do not
13616 allow variably-modified types as template arguments. */
13617 else if (variably_modified_type_p (t, NULL_TREE))
13619 if (complain & tf_error)
13620 error ("%qT is a variably modified type", t);
13624 /* A non-type argument of integral or enumerated type must be a
13626 else if (TREE_TYPE (t)
13627 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t))
13628 && !TREE_CONSTANT (t))
13630 if (complain & tf_error)
13631 error ("integral expression %qE is not constant", t);
13638 check_instantiated_args (tree tmpl, tree args, tsubst_flags_t complain)
13640 int ix, len = DECL_NTPARMS (tmpl);
13641 bool result = false;
13643 for (ix = 0; ix != len; ix++)
13645 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (args, ix), complain))
13648 if (result && (complain & tf_error))
13649 error (" trying to instantiate %qD", tmpl);
13653 /* In C++0x, it's possible to have a function template whose type depends
13654 on itself recursively. This is most obvious with decltype, but can also
13655 occur with enumeration scope (c++/48969). So we need to catch infinite
13656 recursion and reject the substitution at deduction time; this function
13657 will return error_mark_node for any repeated substitution.
13659 This also catches excessive recursion such as when f<N> depends on
13660 f<N-1> across all integers, and returns error_mark_node for all the
13661 substitutions back up to the initial one.
13663 This is, of course, not reentrant. */
13666 deduction_tsubst_fntype (tree fn, tree targs)
13668 static bool excessive_deduction_depth;
13669 static int deduction_depth;
13670 struct pending_template *old_last_pend = last_pending_template;
13672 tree fntype = TREE_TYPE (fn);
13676 if (excessive_deduction_depth)
13677 return error_mark_node;
13679 tinst = build_tree_list (fn, targs);
13680 if (!push_tinst_level (tinst))
13682 excessive_deduction_depth = true;
13684 return error_mark_node;
13687 input_location = DECL_SOURCE_LOCATION (fn);
13689 push_deduction_access_scope (fn);
13690 r = tsubst (fntype, targs, tf_none, NULL_TREE);
13691 pop_deduction_access_scope (fn);
13694 if (excessive_deduction_depth)
13696 r = error_mark_node;
13697 if (deduction_depth == 0)
13698 /* Reset once we're all the way out. */
13699 excessive_deduction_depth = false;
13702 pop_tinst_level ();
13703 /* We can't free this if a pending_template entry is pointing at it. */
13704 if (last_pending_template == old_last_pend)
13709 /* Instantiate the indicated variable or function template TMPL with
13710 the template arguments in TARG_PTR. */
13713 instantiate_template_1 (tree tmpl, tree orig_args, tsubst_flags_t complain)
13715 tree targ_ptr = orig_args;
13719 HOST_WIDE_INT saved_processing_template_decl;
13721 if (tmpl == error_mark_node)
13722 return error_mark_node;
13724 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
13726 /* If this function is a clone, handle it specially. */
13727 if (DECL_CLONED_FUNCTION_P (tmpl))
13732 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
13733 DECL_CLONED_FUNCTION. */
13734 spec = instantiate_template (DECL_ABSTRACT_ORIGIN (tmpl),
13735 targ_ptr, complain);
13736 if (spec == error_mark_node)
13737 return error_mark_node;
13739 /* Look for the clone. */
13740 FOR_EACH_CLONE (clone, spec)
13741 if (DECL_NAME (clone) == DECL_NAME (tmpl))
13743 /* We should always have found the clone by now. */
13744 gcc_unreachable ();
13748 /* Check to see if we already have this specialization. */
13749 gen_tmpl = most_general_template (tmpl);
13750 if (tmpl != gen_tmpl)
13751 /* The TMPL is a partial instantiation. To get a full set of
13752 arguments we must add the arguments used to perform the
13753 partial instantiation. */
13754 targ_ptr = add_outermost_template_args (DECL_TI_ARGS (tmpl),
13757 /* It would be nice to avoid hashing here and then again in tsubst_decl,
13758 but it doesn't seem to be on the hot path. */
13759 spec = retrieve_specialization (gen_tmpl, targ_ptr, 0);
13761 gcc_assert (tmpl == gen_tmpl
13762 || ((fndecl = retrieve_specialization (tmpl, orig_args, 0))
13764 || fndecl == NULL_TREE);
13766 if (spec != NULL_TREE)
13769 if (check_instantiated_args (gen_tmpl, INNERMOST_TEMPLATE_ARGS (targ_ptr),
13771 return error_mark_node;
13773 /* We are building a FUNCTION_DECL, during which the access of its
13774 parameters and return types have to be checked. However this
13775 FUNCTION_DECL which is the desired context for access checking
13776 is not built yet. We solve this chicken-and-egg problem by
13777 deferring all checks until we have the FUNCTION_DECL. */
13778 push_deferring_access_checks (dk_deferred);
13780 /* Although PROCESSING_TEMPLATE_DECL may be true at this point
13781 (because, for example, we have encountered a non-dependent
13782 function call in the body of a template function and must now
13783 determine which of several overloaded functions will be called),
13784 within the instantiation itself we are not processing a
13786 saved_processing_template_decl = processing_template_decl;
13787 processing_template_decl = 0;
13788 /* Substitute template parameters to obtain the specialization. */
13789 fndecl = tsubst (DECL_TEMPLATE_RESULT (gen_tmpl),
13790 targ_ptr, complain, gen_tmpl);
13791 processing_template_decl = saved_processing_template_decl;
13792 if (fndecl == error_mark_node)
13793 return error_mark_node;
13795 /* Now we know the specialization, compute access previously
13797 push_access_scope (fndecl);
13799 /* Some typedefs referenced from within the template code need to be access
13800 checked at template instantiation time, i.e now. These types were
13801 added to the template at parsing time. Let's get those and perfom
13802 the acces checks then. */
13803 perform_typedefs_access_check (DECL_TEMPLATE_RESULT (tmpl), targ_ptr);
13804 perform_deferred_access_checks ();
13805 pop_access_scope (fndecl);
13806 pop_deferring_access_checks ();
13808 /* The DECL_TI_TEMPLATE should always be the immediate parent
13809 template, not the most general template. */
13810 DECL_TI_TEMPLATE (fndecl) = tmpl;
13812 /* If we've just instantiated the main entry point for a function,
13813 instantiate all the alternate entry points as well. We do this
13814 by cloning the instantiation of the main entry point, not by
13815 instantiating the template clones. */
13816 if (DECL_CHAIN (gen_tmpl) && DECL_CLONED_FUNCTION_P (DECL_CHAIN (gen_tmpl)))
13817 clone_function_decl (fndecl, /*update_method_vec_p=*/0);
13822 /* Wrapper for instantiate_template_1. */
13825 instantiate_template (tree tmpl, tree orig_args, tsubst_flags_t complain)
13828 timevar_push (TV_TEMPLATE_INST);
13829 ret = instantiate_template_1 (tmpl, orig_args, complain);
13830 timevar_pop (TV_TEMPLATE_INST);
13834 /* We're going to do deduction substitution on the type of TMPL, a function
13835 template. In C++11 mode, push into that access scope. In C++03 mode,
13836 disable access checking. */
13839 push_deduction_access_scope (tree tmpl)
13841 if (cxx_dialect >= cxx0x)
13842 push_access_scope (DECL_TEMPLATE_RESULT (tmpl));
13844 push_deferring_access_checks (dk_no_check);
13847 /* And pop back out. */
13850 pop_deduction_access_scope (tree tmpl)
13852 if (cxx_dialect >= cxx0x)
13853 pop_access_scope (DECL_TEMPLATE_RESULT (tmpl));
13855 pop_deferring_access_checks ();
13858 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
13859 NARGS elements of the arguments that are being used when calling
13860 it. TARGS is a vector into which the deduced template arguments
13863 Return zero for success, 2 for an incomplete match that doesn't resolve
13864 all the types, and 1 for complete failure. An error message will be
13865 printed only for an incomplete match.
13867 If FN is a conversion operator, or we are trying to produce a specific
13868 specialization, RETURN_TYPE is the return type desired.
13870 The EXPLICIT_TARGS are explicit template arguments provided via a
13873 The parameter STRICT is one of:
13876 We are deducing arguments for a function call, as in
13877 [temp.deduct.call].
13880 We are deducing arguments for a conversion function, as in
13881 [temp.deduct.conv].
13884 We are deducing arguments when doing an explicit instantiation
13885 as in [temp.explicit], when determining an explicit specialization
13886 as in [temp.expl.spec], or when taking the address of a function
13887 template, as in [temp.deduct.funcaddr]. */
13890 fn_type_unification (tree fn,
13891 tree explicit_targs,
13894 unsigned int nargs,
13896 unification_kind_t strict,
13902 bool incomplete_argument_packs_p = false;
13904 gcc_assert (TREE_CODE (fn) == TEMPLATE_DECL);
13906 fntype = TREE_TYPE (fn);
13907 if (explicit_targs)
13911 The specified template arguments must match the template
13912 parameters in kind (i.e., type, nontype, template), and there
13913 must not be more arguments than there are parameters;
13914 otherwise type deduction fails.
13916 Nontype arguments must match the types of the corresponding
13917 nontype template parameters, or must be convertible to the
13918 types of the corresponding nontype parameters as specified in
13919 _temp.arg.nontype_, otherwise type deduction fails.
13921 All references in the function type of the function template
13922 to the corresponding template parameters are replaced by the
13923 specified template argument values. If a substitution in a
13924 template parameter or in the function type of the function
13925 template results in an invalid type, type deduction fails. */
13926 tree tparms = DECL_INNERMOST_TEMPLATE_PARMS (fn);
13927 int i, len = TREE_VEC_LENGTH (tparms);
13928 tree converted_args;
13929 bool incomplete = false;
13931 if (explicit_targs == error_mark_node)
13935 = (coerce_template_parms (tparms, explicit_targs, NULL_TREE, tf_none,
13936 /*require_all_args=*/false,
13937 /*use_default_args=*/false));
13938 if (converted_args == error_mark_node)
13941 /* Substitute the explicit args into the function type. This is
13942 necessary so that, for instance, explicitly declared function
13943 arguments can match null pointed constants. If we were given
13944 an incomplete set of explicit args, we must not do semantic
13945 processing during substitution as we could create partial
13947 for (i = 0; i < len; i++)
13949 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
13950 bool parameter_pack = false;
13952 /* Dig out the actual parm. */
13953 if (TREE_CODE (parm) == TYPE_DECL
13954 || TREE_CODE (parm) == TEMPLATE_DECL)
13956 parm = TREE_TYPE (parm);
13957 parameter_pack = TEMPLATE_TYPE_PARAMETER_PACK (parm);
13959 else if (TREE_CODE (parm) == PARM_DECL)
13961 parm = DECL_INITIAL (parm);
13962 parameter_pack = TEMPLATE_PARM_PARAMETER_PACK (parm);
13965 if (parameter_pack)
13969 template_parm_level_and_index (parm, &level, &idx);
13971 /* Mark the argument pack as "incomplete". We could
13972 still deduce more arguments during unification.
13973 We remove this mark in type_unification_real. */
13974 targ = TMPL_ARG (converted_args, level, idx);
13977 ARGUMENT_PACK_INCOMPLETE_P(targ) = 1;
13978 ARGUMENT_PACK_EXPLICIT_ARGS (targ)
13979 = ARGUMENT_PACK_ARGS (targ);
13982 /* We have some incomplete argument packs. */
13983 incomplete_argument_packs_p = true;
13987 if (incomplete_argument_packs_p)
13988 /* Any substitution is guaranteed to be incomplete if there
13989 are incomplete argument packs, because we can still deduce
13993 incomplete = NUM_TMPL_ARGS (explicit_targs) != NUM_TMPL_ARGS (targs);
13995 processing_template_decl += incomplete;
13996 fntype = deduction_tsubst_fntype (fn, converted_args);
13997 processing_template_decl -= incomplete;
13999 if (fntype == error_mark_node)
14002 /* Place the explicitly specified arguments in TARGS. */
14003 for (i = NUM_TMPL_ARGS (converted_args); i--;)
14004 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (converted_args, i);
14007 /* Never do unification on the 'this' parameter. */
14008 parms = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (fntype));
14014 parms = tree_cons (NULL_TREE, TREE_TYPE (fntype), parms);
14015 new_args = XALLOCAVEC (tree, nargs + 1);
14016 new_args[0] = return_type;
14017 memcpy (new_args + 1, args, nargs * sizeof (tree));
14022 /* We allow incomplete unification without an error message here
14023 because the standard doesn't seem to explicitly prohibit it. Our
14024 callers must be ready to deal with unification failures in any
14026 result = type_unification_real (DECL_INNERMOST_TEMPLATE_PARMS (fn),
14027 targs, parms, args, nargs, /*subr=*/0,
14030 /* Now that we have bindings for all of the template arguments,
14031 ensure that the arguments deduced for the template template
14032 parameters have compatible template parameter lists. We cannot
14033 check this property before we have deduced all template
14034 arguments, because the template parameter types of a template
14035 template parameter might depend on prior template parameters
14036 deduced after the template template parameter. The following
14037 ill-formed example illustrates this issue:
14039 template<typename T, template<T> class C> void f(C<5>, T);
14041 template<int N> struct X {};
14044 f(X<5>(), 5l); // error: template argument deduction fails
14047 The template parameter list of 'C' depends on the template type
14048 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
14049 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
14050 time that we deduce 'C'. */
14052 && !template_template_parm_bindings_ok_p
14053 (DECL_INNERMOST_TEMPLATE_PARMS (fn), targs))
14057 /* All is well so far. Now, check:
14061 When all template arguments have been deduced, all uses of
14062 template parameters in nondeduced contexts are replaced with
14063 the corresponding deduced argument values. If the
14064 substitution results in an invalid type, as described above,
14065 type deduction fails. */
14067 tree substed = deduction_tsubst_fntype (fn, targs);
14068 if (substed == error_mark_node)
14071 /* If we're looking for an exact match, check that what we got
14072 is indeed an exact match. It might not be if some template
14073 parameters are used in non-deduced contexts. */
14074 if (strict == DEDUCE_EXACT)
14079 = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (substed));
14081 sarg = tree_cons (NULL_TREE, TREE_TYPE (substed), sarg);
14082 for (i = 0; i < nargs && sarg; ++i, sarg = TREE_CHAIN (sarg))
14083 if (!same_type_p (args[i], TREE_VALUE (sarg)))
14091 /* Adjust types before performing type deduction, as described in
14092 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
14093 sections are symmetric. PARM is the type of a function parameter
14094 or the return type of the conversion function. ARG is the type of
14095 the argument passed to the call, or the type of the value
14096 initialized with the result of the conversion function.
14097 ARG_EXPR is the original argument expression, which may be null. */
14100 maybe_adjust_types_for_deduction (unification_kind_t strict,
14114 /* Swap PARM and ARG throughout the remainder of this
14115 function; the handling is precisely symmetric since PARM
14116 will initialize ARG rather than vice versa. */
14124 /* Core issue #873: Do the DR606 thing (see below) for these cases,
14125 too, but here handle it by stripping the reference from PARM
14126 rather than by adding it to ARG. */
14127 if (TREE_CODE (*parm) == REFERENCE_TYPE
14128 && TYPE_REF_IS_RVALUE (*parm)
14129 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
14130 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
14131 && TREE_CODE (*arg) == REFERENCE_TYPE
14132 && !TYPE_REF_IS_RVALUE (*arg))
14133 *parm = TREE_TYPE (*parm);
14134 /* Nothing else to do in this case. */
14138 gcc_unreachable ();
14141 if (TREE_CODE (*parm) != REFERENCE_TYPE)
14143 /* [temp.deduct.call]
14145 If P is not a reference type:
14147 --If A is an array type, the pointer type produced by the
14148 array-to-pointer standard conversion (_conv.array_) is
14149 used in place of A for type deduction; otherwise,
14151 --If A is a function type, the pointer type produced by
14152 the function-to-pointer standard conversion
14153 (_conv.func_) is used in place of A for type deduction;
14156 --If A is a cv-qualified type, the top level
14157 cv-qualifiers of A's type are ignored for type
14159 if (TREE_CODE (*arg) == ARRAY_TYPE)
14160 *arg = build_pointer_type (TREE_TYPE (*arg));
14161 else if (TREE_CODE (*arg) == FUNCTION_TYPE)
14162 *arg = build_pointer_type (*arg);
14164 *arg = TYPE_MAIN_VARIANT (*arg);
14167 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
14168 of the form T&&, where T is a template parameter, and the argument
14169 is an lvalue, T is deduced as A& */
14170 if (TREE_CODE (*parm) == REFERENCE_TYPE
14171 && TYPE_REF_IS_RVALUE (*parm)
14172 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
14173 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
14174 && (arg_expr ? real_lvalue_p (arg_expr)
14175 /* try_one_overload doesn't provide an arg_expr, but
14176 functions are always lvalues. */
14177 : TREE_CODE (*arg) == FUNCTION_TYPE))
14178 *arg = build_reference_type (*arg);
14180 /* [temp.deduct.call]
14182 If P is a cv-qualified type, the top level cv-qualifiers
14183 of P's type are ignored for type deduction. If P is a
14184 reference type, the type referred to by P is used for
14186 *parm = TYPE_MAIN_VARIANT (*parm);
14187 if (TREE_CODE (*parm) == REFERENCE_TYPE)
14189 *parm = TREE_TYPE (*parm);
14190 result |= UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
14193 /* DR 322. For conversion deduction, remove a reference type on parm
14194 too (which has been swapped into ARG). */
14195 if (strict == DEDUCE_CONV && TREE_CODE (*arg) == REFERENCE_TYPE)
14196 *arg = TREE_TYPE (*arg);
14201 /* Most parms like fn_type_unification.
14203 If SUBR is 1, we're being called recursively (to unify the
14204 arguments of a function or method parameter of a function
14208 type_unification_real (tree tparms,
14212 unsigned int xnargs,
14214 unification_kind_t strict,
14217 tree parm, arg, arg_expr;
14219 int ntparms = TREE_VEC_LENGTH (tparms);
14221 int saw_undeduced = 0;
14224 unsigned int nargs;
14227 gcc_assert (TREE_CODE (tparms) == TREE_VEC);
14228 gcc_assert (xparms == NULL_TREE || TREE_CODE (xparms) == TREE_LIST);
14229 gcc_assert (ntparms > 0);
14231 /* Reset the number of non-defaulted template arguments contained
14233 NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs) = NULL_TREE;
14238 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL | UNIFY_ALLOW_MORE_CV_QUAL
14239 | UNIFY_ALLOW_DERIVED);
14243 sub_strict = UNIFY_ALLOW_LESS_CV_QUAL;
14247 sub_strict = UNIFY_ALLOW_NONE;
14251 gcc_unreachable ();
14260 while (parms && parms != void_list_node
14263 parm = TREE_VALUE (parms);
14265 if (TREE_CODE (parm) == TYPE_PACK_EXPANSION
14266 && (!TREE_CHAIN (parms) || TREE_CHAIN (parms) == void_list_node))
14267 /* For a function parameter pack that occurs at the end of the
14268 parameter-declaration-list, the type A of each remaining
14269 argument of the call is compared with the type P of the
14270 declarator-id of the function parameter pack. */
14273 parms = TREE_CHAIN (parms);
14275 if (TREE_CODE (parm) == TYPE_PACK_EXPANSION)
14276 /* For a function parameter pack that does not occur at the
14277 end of the parameter-declaration-list, the type of the
14278 parameter pack is a non-deduced context. */
14285 if (arg == error_mark_node)
14287 if (arg == unknown_type_node)
14288 /* We can't deduce anything from this, but we might get all the
14289 template args from other function args. */
14292 /* Conversions will be performed on a function argument that
14293 corresponds with a function parameter that contains only
14294 non-deducible template parameters and explicitly specified
14295 template parameters. */
14296 if (!uses_template_parms (parm))
14301 type = TREE_TYPE (arg);
14305 if (same_type_p (parm, type))
14307 if (strict != DEDUCE_EXACT
14308 && can_convert_arg (parm, type, TYPE_P (arg) ? NULL_TREE : arg,
14317 gcc_assert (TREE_TYPE (arg) != NULL_TREE);
14318 if (type_unknown_p (arg))
14320 /* [temp.deduct.type]
14322 A template-argument can be deduced from a pointer to
14323 function or pointer to member function argument if
14324 the set of overloaded functions does not contain
14325 function templates and at most one of a set of
14326 overloaded functions provides a unique match. */
14327 if (resolve_overloaded_unification
14328 (tparms, targs, parm, arg, strict, sub_strict))
14334 arg = unlowered_expr_type (arg);
14335 if (arg == error_mark_node)
14340 int arg_strict = sub_strict;
14343 arg_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg,
14346 if (arg == init_list_type_node && arg_expr)
14348 if (unify (tparms, targs, parm, arg, arg_strict))
14355 && parms != void_list_node
14356 && TREE_CODE (TREE_VALUE (parms)) == TYPE_PACK_EXPANSION)
14358 /* Unify the remaining arguments with the pack expansion type. */
14360 tree parmvec = make_tree_vec (1);
14362 /* Allocate a TREE_VEC and copy in all of the arguments */
14363 argvec = make_tree_vec (nargs - ia);
14364 for (i = 0; ia < nargs; ++ia, ++i)
14365 TREE_VEC_ELT (argvec, i) = args[ia];
14367 /* Copy the parameter into parmvec. */
14368 TREE_VEC_ELT (parmvec, 0) = TREE_VALUE (parms);
14369 if (unify_pack_expansion (tparms, targs, parmvec, argvec, strict,
14370 /*call_args_p=*/true, /*subr=*/subr))
14373 /* Advance to the end of the list of parameters. */
14374 parms = TREE_CHAIN (parms);
14377 /* Fail if we've reached the end of the parm list, and more args
14378 are present, and the parm list isn't variadic. */
14379 if (ia < nargs && parms == void_list_node)
14381 /* Fail if parms are left and they don't have default values. */
14382 if (parms && parms != void_list_node
14383 && TREE_PURPOSE (parms) == NULL_TREE)
14388 /* Check to see if we need another pass before we start clearing
14389 ARGUMENT_PACK_INCOMPLETE_P. */
14390 for (i = 0; i < ntparms; i++)
14392 tree targ = TREE_VEC_ELT (targs, i);
14393 tree tparm = TREE_VEC_ELT (tparms, i);
14395 if (targ || tparm == error_mark_node)
14397 tparm = TREE_VALUE (tparm);
14399 /* If this is an undeduced nontype parameter that depends on
14400 a type parameter, try another pass; its type may have been
14401 deduced from a later argument than the one from which
14402 this parameter can be deduced. */
14403 if (TREE_CODE (tparm) == PARM_DECL
14404 && uses_template_parms (TREE_TYPE (tparm))
14405 && !saw_undeduced++)
14409 for (i = 0; i < ntparms; i++)
14411 tree targ = TREE_VEC_ELT (targs, i);
14412 tree tparm = TREE_VEC_ELT (tparms, i);
14414 /* Clear the "incomplete" flags on all argument packs now so that
14415 substituting them into later default arguments works. */
14416 if (targ && ARGUMENT_PACK_P (targ))
14418 ARGUMENT_PACK_INCOMPLETE_P (targ) = 0;
14419 ARGUMENT_PACK_EXPLICIT_ARGS (targ) = NULL_TREE;
14422 if (targ || tparm == error_mark_node)
14424 tparm = TREE_VALUE (tparm);
14426 /* Core issue #226 (C++0x) [temp.deduct]:
14428 If a template argument has not been deduced, its
14429 default template argument, if any, is used.
14431 When we are in C++98 mode, TREE_PURPOSE will either
14432 be NULL_TREE or ERROR_MARK_NODE, so we do not need
14433 to explicitly check cxx_dialect here. */
14434 if (TREE_PURPOSE (TREE_VEC_ELT (tparms, i)))
14436 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
14437 tree arg = TREE_PURPOSE (TREE_VEC_ELT (tparms, i));
14438 arg = tsubst_template_arg (arg, targs, tf_none, NULL_TREE);
14439 arg = convert_template_argument (parm, arg, targs, tf_none,
14441 if (arg == error_mark_node)
14445 TREE_VEC_ELT (targs, i) = arg;
14446 /* The position of the first default template argument,
14447 is also the number of non-defaulted arguments in TARGS.
14449 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs))
14450 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, i);
14455 /* If the type parameter is a parameter pack, then it will
14456 be deduced to an empty parameter pack. */
14457 if (template_parameter_pack_p (tparm))
14461 if (TREE_CODE (tparm) == TEMPLATE_PARM_INDEX)
14463 arg = make_node (NONTYPE_ARGUMENT_PACK);
14464 TREE_TYPE (arg) = TREE_TYPE (TEMPLATE_PARM_DECL (tparm));
14465 TREE_CONSTANT (arg) = 1;
14468 arg = cxx_make_type (TYPE_ARGUMENT_PACK);
14470 SET_ARGUMENT_PACK_ARGS (arg, make_tree_vec (0));
14472 TREE_VEC_ELT (targs, i) = arg;
14479 #ifdef ENABLE_CHECKING
14480 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs))
14481 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, TREE_VEC_LENGTH (targs));
14487 /* Subroutine of type_unification_real. Args are like the variables
14488 at the call site. ARG is an overloaded function (or template-id);
14489 we try deducing template args from each of the overloads, and if
14490 only one succeeds, we go with that. Modifies TARGS and returns
14491 true on success. */
14494 resolve_overloaded_unification (tree tparms,
14498 unification_kind_t strict,
14501 tree tempargs = copy_node (targs);
14503 tree goodfn = NULL_TREE;
14506 if (TREE_CODE (arg) == ADDR_EXPR)
14508 arg = TREE_OPERAND (arg, 0);
14514 if (TREE_CODE (arg) == COMPONENT_REF)
14515 /* Handle `&x' where `x' is some static or non-static member
14517 arg = TREE_OPERAND (arg, 1);
14519 if (TREE_CODE (arg) == OFFSET_REF)
14520 arg = TREE_OPERAND (arg, 1);
14522 /* Strip baselink information. */
14523 if (BASELINK_P (arg))
14524 arg = BASELINK_FUNCTIONS (arg);
14526 if (TREE_CODE (arg) == TEMPLATE_ID_EXPR)
14528 /* If we got some explicit template args, we need to plug them into
14529 the affected templates before we try to unify, in case the
14530 explicit args will completely resolve the templates in question. */
14533 tree expl_subargs = TREE_OPERAND (arg, 1);
14534 arg = TREE_OPERAND (arg, 0);
14536 for (; arg; arg = OVL_NEXT (arg))
14538 tree fn = OVL_CURRENT (arg);
14539 tree subargs, elem;
14541 if (TREE_CODE (fn) != TEMPLATE_DECL)
14544 ++processing_template_decl;
14545 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
14546 expl_subargs, /*check_ret=*/false);
14547 if (subargs && !any_dependent_template_arguments_p (subargs))
14549 elem = tsubst (TREE_TYPE (fn), subargs, tf_none, NULL_TREE);
14550 if (try_one_overload (tparms, targs, tempargs, parm,
14551 elem, strict, sub_strict, addr_p)
14552 && (!goodfn || !decls_match (goodfn, elem)))
14560 --processing_template_decl;
14562 /* If no templates (or more than one) are fully resolved by the
14563 explicit arguments, this template-id is a non-deduced context; it
14564 could still be OK if we deduce all template arguments for the
14565 enclosing call through other arguments. */
14569 else if (TREE_CODE (arg) != OVERLOAD
14570 && TREE_CODE (arg) != FUNCTION_DECL)
14571 /* If ARG is, for example, "(0, &f)" then its type will be unknown
14572 -- but the deduction does not succeed because the expression is
14573 not just the function on its own. */
14576 for (; arg; arg = OVL_NEXT (arg))
14577 if (try_one_overload (tparms, targs, tempargs, parm,
14578 TREE_TYPE (OVL_CURRENT (arg)),
14579 strict, sub_strict, addr_p)
14580 && (!goodfn || !decls_match (goodfn, OVL_CURRENT (arg))))
14582 goodfn = OVL_CURRENT (arg);
14586 /* [temp.deduct.type] A template-argument can be deduced from a pointer
14587 to function or pointer to member function argument if the set of
14588 overloaded functions does not contain function templates and at most
14589 one of a set of overloaded functions provides a unique match.
14591 So if we found multiple possibilities, we return success but don't
14592 deduce anything. */
14596 int i = TREE_VEC_LENGTH (targs);
14598 if (TREE_VEC_ELT (tempargs, i))
14599 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (tempargs, i);
14607 /* Core DR 115: In contexts where deduction is done and fails, or in
14608 contexts where deduction is not done, if a template argument list is
14609 specified and it, along with any default template arguments, identifies
14610 a single function template specialization, then the template-id is an
14611 lvalue for the function template specialization. */
14614 resolve_nondeduced_context (tree orig_expr)
14616 tree expr, offset, baselink;
14619 if (!type_unknown_p (orig_expr))
14624 offset = NULL_TREE;
14625 baselink = NULL_TREE;
14627 if (TREE_CODE (expr) == ADDR_EXPR)
14629 expr = TREE_OPERAND (expr, 0);
14632 if (TREE_CODE (expr) == OFFSET_REF)
14635 expr = TREE_OPERAND (expr, 1);
14637 if (TREE_CODE (expr) == BASELINK)
14640 expr = BASELINK_FUNCTIONS (expr);
14643 if (TREE_CODE (expr) == TEMPLATE_ID_EXPR)
14646 tree goodfn = NULL_TREE;
14648 /* If we got some explicit template args, we need to plug them into
14649 the affected templates before we try to unify, in case the
14650 explicit args will completely resolve the templates in question. */
14652 tree expl_subargs = TREE_OPERAND (expr, 1);
14653 tree arg = TREE_OPERAND (expr, 0);
14654 tree badfn = NULL_TREE;
14655 tree badargs = NULL_TREE;
14657 for (; arg; arg = OVL_NEXT (arg))
14659 tree fn = OVL_CURRENT (arg);
14660 tree subargs, elem;
14662 if (TREE_CODE (fn) != TEMPLATE_DECL)
14665 ++processing_template_decl;
14666 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
14667 expl_subargs, /*check_ret=*/false);
14668 if (subargs && !any_dependent_template_arguments_p (subargs))
14670 elem = instantiate_template (fn, subargs, tf_none);
14671 if (elem == error_mark_node)
14676 else if (elem && (!goodfn || !decls_match (goodfn, elem)))
14682 --processing_template_decl;
14686 mark_used (goodfn);
14689 expr = build_baselink (BASELINK_BINFO (baselink),
14690 BASELINK_ACCESS_BINFO (baselink),
14691 expr, BASELINK_OPTYPE (baselink));
14695 = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (offset, 0)));
14696 expr = build_offset_ref (base, expr, addr);
14699 expr = cp_build_addr_expr (expr, tf_warning_or_error);
14702 else if (good == 0 && badargs)
14703 /* There were no good options and at least one bad one, so let the
14704 user know what the problem is. */
14705 instantiate_template (badfn, badargs, tf_warning_or_error);
14710 /* Subroutine of resolve_overloaded_unification; does deduction for a single
14711 overload. Fills TARGS with any deduced arguments, or error_mark_node if
14712 different overloads deduce different arguments for a given parm.
14713 ADDR_P is true if the expression for which deduction is being
14714 performed was of the form "& fn" rather than simply "fn".
14716 Returns 1 on success. */
14719 try_one_overload (tree tparms,
14724 unification_kind_t strict,
14732 /* [temp.deduct.type] A template-argument can be deduced from a pointer
14733 to function or pointer to member function argument if the set of
14734 overloaded functions does not contain function templates and at most
14735 one of a set of overloaded functions provides a unique match.
14737 So if this is a template, just return success. */
14739 if (uses_template_parms (arg))
14742 if (TREE_CODE (arg) == METHOD_TYPE)
14743 arg = build_ptrmemfunc_type (build_pointer_type (arg));
14745 arg = build_pointer_type (arg);
14747 sub_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg, NULL);
14749 /* We don't copy orig_targs for this because if we have already deduced
14750 some template args from previous args, unify would complain when we
14751 try to deduce a template parameter for the same argument, even though
14752 there isn't really a conflict. */
14753 nargs = TREE_VEC_LENGTH (targs);
14754 tempargs = make_tree_vec (nargs);
14756 if (unify (tparms, tempargs, parm, arg, sub_strict) != 0)
14759 /* First make sure we didn't deduce anything that conflicts with
14760 explicitly specified args. */
14761 for (i = nargs; i--; )
14763 tree elt = TREE_VEC_ELT (tempargs, i);
14764 tree oldelt = TREE_VEC_ELT (orig_targs, i);
14768 else if (uses_template_parms (elt))
14769 /* Since we're unifying against ourselves, we will fill in
14770 template args used in the function parm list with our own
14771 template parms. Discard them. */
14772 TREE_VEC_ELT (tempargs, i) = NULL_TREE;
14773 else if (oldelt && !template_args_equal (oldelt, elt))
14777 for (i = nargs; i--; )
14779 tree elt = TREE_VEC_ELT (tempargs, i);
14782 TREE_VEC_ELT (targs, i) = elt;
14788 /* PARM is a template class (perhaps with unbound template
14789 parameters). ARG is a fully instantiated type. If ARG can be
14790 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
14791 TARGS are as for unify. */
14794 try_class_unification (tree tparms, tree targs, tree parm, tree arg)
14796 tree copy_of_targs;
14798 if (!CLASSTYPE_TEMPLATE_INFO (arg)
14799 || (most_general_template (CLASSTYPE_TI_TEMPLATE (arg))
14800 != most_general_template (CLASSTYPE_TI_TEMPLATE (parm))))
14803 /* We need to make a new template argument vector for the call to
14804 unify. If we used TARGS, we'd clutter it up with the result of
14805 the attempted unification, even if this class didn't work out.
14806 We also don't want to commit ourselves to all the unifications
14807 we've already done, since unification is supposed to be done on
14808 an argument-by-argument basis. In other words, consider the
14809 following pathological case:
14811 template <int I, int J, int K>
14814 template <int I, int J>
14815 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
14817 template <int I, int J, int K>
14818 void f(S<I, J, K>, S<I, I, I>);
14827 Now, by the time we consider the unification involving `s2', we
14828 already know that we must have `f<0, 0, 0>'. But, even though
14829 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
14830 because there are two ways to unify base classes of S<0, 1, 2>
14831 with S<I, I, I>. If we kept the already deduced knowledge, we
14832 would reject the possibility I=1. */
14833 copy_of_targs = make_tree_vec (TREE_VEC_LENGTH (targs));
14835 /* If unification failed, we're done. */
14836 if (unify (tparms, copy_of_targs, CLASSTYPE_TI_ARGS (parm),
14837 CLASSTYPE_TI_ARGS (arg), UNIFY_ALLOW_NONE))
14843 /* Given a template type PARM and a class type ARG, find the unique
14844 base type in ARG that is an instance of PARM. We do not examine
14845 ARG itself; only its base-classes. If there is not exactly one
14846 appropriate base class, return NULL_TREE. PARM may be the type of
14847 a partial specialization, as well as a plain template type. Used
14851 get_template_base (tree tparms, tree targs, tree parm, tree arg)
14853 tree rval = NULL_TREE;
14856 gcc_assert (RECORD_OR_UNION_CODE_P (TREE_CODE (arg)));
14858 binfo = TYPE_BINFO (complete_type (arg));
14860 /* The type could not be completed. */
14863 /* Walk in inheritance graph order. The search order is not
14864 important, and this avoids multiple walks of virtual bases. */
14865 for (binfo = TREE_CHAIN (binfo); binfo; binfo = TREE_CHAIN (binfo))
14867 tree r = try_class_unification (tparms, targs, parm, BINFO_TYPE (binfo));
14871 /* If there is more than one satisfactory baseclass, then:
14875 If they yield more than one possible deduced A, the type
14879 if (rval && !same_type_p (r, rval))
14889 /* Returns the level of DECL, which declares a template parameter. */
14892 template_decl_level (tree decl)
14894 switch (TREE_CODE (decl))
14897 case TEMPLATE_DECL:
14898 return TEMPLATE_TYPE_LEVEL (TREE_TYPE (decl));
14901 return TEMPLATE_PARM_LEVEL (DECL_INITIAL (decl));
14904 gcc_unreachable ();
14909 /* Decide whether ARG can be unified with PARM, considering only the
14910 cv-qualifiers of each type, given STRICT as documented for unify.
14911 Returns nonzero iff the unification is OK on that basis. */
14914 check_cv_quals_for_unify (int strict, tree arg, tree parm)
14916 int arg_quals = cp_type_quals (arg);
14917 int parm_quals = cp_type_quals (parm);
14919 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
14920 && !(strict & UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
14922 /* Although a CVR qualifier is ignored when being applied to a
14923 substituted template parameter ([8.3.2]/1 for example), that
14924 does not allow us to unify "const T" with "int&" because both
14925 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
14926 It is ok when we're allowing additional CV qualifiers
14927 at the outer level [14.8.2.1]/3,1st bullet. */
14928 if ((TREE_CODE (arg) == REFERENCE_TYPE
14929 || TREE_CODE (arg) == FUNCTION_TYPE
14930 || TREE_CODE (arg) == METHOD_TYPE)
14931 && (parm_quals & (TYPE_QUAL_CONST | TYPE_QUAL_VOLATILE)))
14934 if ((!POINTER_TYPE_P (arg) && TREE_CODE (arg) != TEMPLATE_TYPE_PARM)
14935 && (parm_quals & TYPE_QUAL_RESTRICT))
14939 if (!(strict & (UNIFY_ALLOW_MORE_CV_QUAL | UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
14940 && (arg_quals & parm_quals) != parm_quals)
14943 if (!(strict & (UNIFY_ALLOW_LESS_CV_QUAL | UNIFY_ALLOW_OUTER_LESS_CV_QUAL))
14944 && (parm_quals & arg_quals) != arg_quals)
14950 /* Determines the LEVEL and INDEX for the template parameter PARM. */
14952 template_parm_level_and_index (tree parm, int* level, int* index)
14954 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
14955 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
14956 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
14958 *index = TEMPLATE_TYPE_IDX (parm);
14959 *level = TEMPLATE_TYPE_LEVEL (parm);
14963 *index = TEMPLATE_PARM_IDX (parm);
14964 *level = TEMPLATE_PARM_LEVEL (parm);
14968 /* Unifies the remaining arguments in PACKED_ARGS with the pack
14969 expansion at the end of PACKED_PARMS. Returns 0 if the type
14970 deduction succeeds, 1 otherwise. STRICT is the same as in
14971 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
14972 call argument list. We'll need to adjust the arguments to make them
14973 types. SUBR tells us if this is from a recursive call to
14974 type_unification_real. */
14976 unify_pack_expansion (tree tparms, tree targs, tree packed_parms,
14977 tree packed_args, int strict, bool call_args_p,
14981 = TREE_VEC_ELT (packed_parms, TREE_VEC_LENGTH (packed_parms) - 1);
14982 tree pattern = PACK_EXPANSION_PATTERN (parm);
14983 tree pack, packs = NULL_TREE;
14984 int i, start = TREE_VEC_LENGTH (packed_parms) - 1;
14985 int len = TREE_VEC_LENGTH (packed_args);
14987 /* Determine the parameter packs we will be deducing from the
14988 pattern, and record their current deductions. */
14989 for (pack = PACK_EXPANSION_PARAMETER_PACKS (parm);
14990 pack; pack = TREE_CHAIN (pack))
14992 tree parm_pack = TREE_VALUE (pack);
14995 /* Determine the index and level of this parameter pack. */
14996 template_parm_level_and_index (parm_pack, &level, &idx);
14998 /* Keep track of the parameter packs and their corresponding
15000 packs = tree_cons (parm_pack, TMPL_ARG (targs, level, idx), packs);
15001 TREE_TYPE (packs) = make_tree_vec (len - start);
15004 /* Loop through all of the arguments that have not yet been
15005 unified and unify each with the pattern. */
15006 for (i = start; i < len; i++)
15008 tree parm = pattern;
15010 /* For each parameter pack, clear out the deduced value so that
15011 we can deduce it again. */
15012 for (pack = packs; pack; pack = TREE_CHAIN (pack))
15015 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
15017 TMPL_ARG (targs, level, idx) = NULL_TREE;
15020 /* Unify the pattern with the current argument. */
15022 tree arg = TREE_VEC_ELT (packed_args, i);
15023 tree arg_expr = NULL_TREE;
15024 int arg_strict = strict;
15025 bool skip_arg_p = false;
15031 /* This mirrors what we do in type_unification_real. */
15035 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL
15036 | UNIFY_ALLOW_MORE_CV_QUAL
15037 | UNIFY_ALLOW_DERIVED);
15041 sub_strict = UNIFY_ALLOW_LESS_CV_QUAL;
15045 sub_strict = UNIFY_ALLOW_NONE;
15049 gcc_unreachable ();
15054 gcc_assert (TREE_TYPE (arg) != NULL_TREE);
15055 if (type_unknown_p (arg))
15057 /* [temp.deduct.type] A template-argument can be
15058 deduced from a pointer to function or pointer
15059 to member function argument if the set of
15060 overloaded functions does not contain function
15061 templates and at most one of a set of
15062 overloaded functions provides a unique
15065 if (resolve_overloaded_unification
15066 (tparms, targs, parm, arg,
15067 (unification_kind_t) strict,
15077 arg = unlowered_expr_type (arg);
15078 if (arg == error_mark_node)
15083 arg_strict = sub_strict;
15087 maybe_adjust_types_for_deduction ((unification_kind_t) strict,
15088 &parm, &arg, arg_expr);
15093 /* For deduction from an init-list we need the actual list. */
15094 if (arg_expr && BRACE_ENCLOSED_INITIALIZER_P (arg_expr))
15096 if (unify (tparms, targs, parm, arg, arg_strict))
15101 /* For each parameter pack, collect the deduced value. */
15102 for (pack = packs; pack; pack = TREE_CHAIN (pack))
15105 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
15107 TREE_VEC_ELT (TREE_TYPE (pack), i - start) =
15108 TMPL_ARG (targs, level, idx);
15112 /* Verify that the results of unification with the parameter packs
15113 produce results consistent with what we've seen before, and make
15114 the deduced argument packs available. */
15115 for (pack = packs; pack; pack = TREE_CHAIN (pack))
15117 tree old_pack = TREE_VALUE (pack);
15118 tree new_args = TREE_TYPE (pack);
15119 int i, len = TREE_VEC_LENGTH (new_args);
15121 bool nondeduced_p = false;
15123 /* By default keep the original deduced argument pack.
15124 If necessary, more specific code is going to update the
15125 resulting deduced argument later down in this function. */
15126 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
15127 TMPL_ARG (targs, level, idx) = old_pack;
15129 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
15130 actually deduce anything. */
15131 for (i = 0; i < len && !nondeduced_p; ++i)
15132 if (TREE_VEC_ELT (new_args, i) == NULL_TREE)
15133 nondeduced_p = true;
15137 if (old_pack && ARGUMENT_PACK_INCOMPLETE_P (old_pack))
15139 /* Prepend the explicit arguments onto NEW_ARGS. */
15140 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
15141 tree old_args = new_args;
15142 int i, explicit_len = TREE_VEC_LENGTH (explicit_args);
15143 int len = explicit_len + TREE_VEC_LENGTH (old_args);
15145 /* Copy the explicit arguments. */
15146 new_args = make_tree_vec (len);
15147 for (i = 0; i < explicit_len; i++)
15148 TREE_VEC_ELT (new_args, i) = TREE_VEC_ELT (explicit_args, i);
15150 /* Copy the deduced arguments. */
15151 for (; i < len; i++)
15152 TREE_VEC_ELT (new_args, i) =
15153 TREE_VEC_ELT (old_args, i - explicit_len);
15159 /* Build the deduced *_ARGUMENT_PACK. */
15160 if (TREE_CODE (TREE_PURPOSE (pack)) == TEMPLATE_PARM_INDEX)
15162 result = make_node (NONTYPE_ARGUMENT_PACK);
15163 TREE_TYPE (result) =
15164 TREE_TYPE (TEMPLATE_PARM_DECL (TREE_PURPOSE (pack)));
15165 TREE_CONSTANT (result) = 1;
15168 result = cxx_make_type (TYPE_ARGUMENT_PACK);
15170 SET_ARGUMENT_PACK_ARGS (result, new_args);
15172 /* Note the deduced argument packs for this parameter
15174 TMPL_ARG (targs, level, idx) = result;
15176 else if (ARGUMENT_PACK_INCOMPLETE_P (old_pack)
15177 && (ARGUMENT_PACK_ARGS (old_pack)
15178 == ARGUMENT_PACK_EXPLICIT_ARGS (old_pack)))
15180 /* We only had the explicitly-provided arguments before, but
15181 now we have a complete set of arguments. */
15182 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
15184 SET_ARGUMENT_PACK_ARGS (old_pack, new_args);
15185 ARGUMENT_PACK_INCOMPLETE_P (old_pack) = 1;
15186 ARGUMENT_PACK_EXPLICIT_ARGS (old_pack) = explicit_args;
15188 else if (!comp_template_args (ARGUMENT_PACK_ARGS (old_pack),
15190 /* Inconsistent unification of this parameter pack. */
15197 /* Deduce the value of template parameters. TPARMS is the (innermost)
15198 set of template parameters to a template. TARGS is the bindings
15199 for those template parameters, as determined thus far; TARGS may
15200 include template arguments for outer levels of template parameters
15201 as well. PARM is a parameter to a template function, or a
15202 subcomponent of that parameter; ARG is the corresponding argument.
15203 This function attempts to match PARM with ARG in a manner
15204 consistent with the existing assignments in TARGS. If more values
15205 are deduced, then TARGS is updated.
15207 Returns 0 if the type deduction succeeds, 1 otherwise. The
15208 parameter STRICT is a bitwise or of the following flags:
15211 Require an exact match between PARM and ARG.
15212 UNIFY_ALLOW_MORE_CV_QUAL:
15213 Allow the deduced ARG to be more cv-qualified (by qualification
15214 conversion) than ARG.
15215 UNIFY_ALLOW_LESS_CV_QUAL:
15216 Allow the deduced ARG to be less cv-qualified than ARG.
15217 UNIFY_ALLOW_DERIVED:
15218 Allow the deduced ARG to be a template base class of ARG,
15219 or a pointer to a template base class of the type pointed to by
15221 UNIFY_ALLOW_INTEGER:
15222 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
15223 case for more information.
15224 UNIFY_ALLOW_OUTER_LEVEL:
15225 This is the outermost level of a deduction. Used to determine validity
15226 of qualification conversions. A valid qualification conversion must
15227 have const qualified pointers leading up to the inner type which
15228 requires additional CV quals, except at the outer level, where const
15229 is not required [conv.qual]. It would be normal to set this flag in
15230 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
15231 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
15232 This is the outermost level of a deduction, and PARM can be more CV
15233 qualified at this point.
15234 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
15235 This is the outermost level of a deduction, and PARM can be less CV
15236 qualified at this point. */
15239 unify (tree tparms, tree targs, tree parm, tree arg, int strict)
15244 int strict_in = strict;
15246 /* I don't think this will do the right thing with respect to types.
15247 But the only case I've seen it in so far has been array bounds, where
15248 signedness is the only information lost, and I think that will be
15250 while (TREE_CODE (parm) == NOP_EXPR)
15251 parm = TREE_OPERAND (parm, 0);
15253 if (arg == error_mark_node)
15255 if (arg == unknown_type_node
15256 || arg == init_list_type_node)
15257 /* We can't deduce anything from this, but we might get all the
15258 template args from other function args. */
15261 /* If PARM uses template parameters, then we can't bail out here,
15262 even if ARG == PARM, since we won't record unifications for the
15263 template parameters. We might need them if we're trying to
15264 figure out which of two things is more specialized. */
15265 if (arg == parm && !uses_template_parms (parm))
15268 /* Handle init lists early, so the rest of the function can assume
15269 we're dealing with a type. */
15270 if (BRACE_ENCLOSED_INITIALIZER_P (arg))
15274 tree orig_parm = parm;
15276 /* Replace T with std::initializer_list<T> for deduction. */
15277 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
15278 && flag_deduce_init_list)
15279 parm = listify (parm);
15281 if (!is_std_init_list (parm))
15282 /* We can only deduce from an initializer list argument if the
15283 parameter is std::initializer_list; otherwise this is a
15284 non-deduced context. */
15287 elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (parm), 0);
15289 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg), i, elt)
15291 int elt_strict = strict;
15293 if (elt == error_mark_node)
15296 if (!BRACE_ENCLOSED_INITIALIZER_P (elt))
15298 tree type = TREE_TYPE (elt);
15299 /* It should only be possible to get here for a call. */
15300 gcc_assert (elt_strict & UNIFY_ALLOW_OUTER_LEVEL);
15301 elt_strict |= maybe_adjust_types_for_deduction
15302 (DEDUCE_CALL, &elttype, &type, elt);
15306 if (unify (tparms, targs, elttype, elt, elt_strict))
15310 /* If the std::initializer_list<T> deduction worked, replace the
15311 deduced A with std::initializer_list<A>. */
15312 if (orig_parm != parm)
15314 idx = TEMPLATE_TYPE_IDX (orig_parm);
15315 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
15316 targ = listify (targ);
15317 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = targ;
15322 /* Immediately reject some pairs that won't unify because of
15323 cv-qualification mismatches. */
15324 if (TREE_CODE (arg) == TREE_CODE (parm)
15326 /* It is the elements of the array which hold the cv quals of an array
15327 type, and the elements might be template type parms. We'll check
15328 when we recurse. */
15329 && TREE_CODE (arg) != ARRAY_TYPE
15330 /* We check the cv-qualifiers when unifying with template type
15331 parameters below. We want to allow ARG `const T' to unify with
15332 PARM `T' for example, when computing which of two templates
15333 is more specialized, for example. */
15334 && TREE_CODE (arg) != TEMPLATE_TYPE_PARM
15335 && !check_cv_quals_for_unify (strict_in, arg, parm))
15338 if (!(strict & UNIFY_ALLOW_OUTER_LEVEL)
15339 && TYPE_P (parm) && !CP_TYPE_CONST_P (parm))
15340 strict &= ~UNIFY_ALLOW_MORE_CV_QUAL;
15341 strict &= ~UNIFY_ALLOW_OUTER_LEVEL;
15342 strict &= ~UNIFY_ALLOW_DERIVED;
15343 strict &= ~UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
15344 strict &= ~UNIFY_ALLOW_OUTER_LESS_CV_QUAL;
15346 switch (TREE_CODE (parm))
15348 case TYPENAME_TYPE:
15350 case UNBOUND_CLASS_TEMPLATE:
15351 /* In a type which contains a nested-name-specifier, template
15352 argument values cannot be deduced for template parameters used
15353 within the nested-name-specifier. */
15356 case TEMPLATE_TYPE_PARM:
15357 case TEMPLATE_TEMPLATE_PARM:
15358 case BOUND_TEMPLATE_TEMPLATE_PARM:
15359 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
15360 if (tparm == error_mark_node)
15363 if (TEMPLATE_TYPE_LEVEL (parm)
15364 != template_decl_level (tparm))
15365 /* The PARM is not one we're trying to unify. Just check
15366 to see if it matches ARG. */
15367 return (TREE_CODE (arg) == TREE_CODE (parm)
15368 && same_type_p (parm, arg)) ? 0 : 1;
15369 idx = TEMPLATE_TYPE_IDX (parm);
15370 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
15371 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, idx));
15373 /* Check for mixed types and values. */
15374 if ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
15375 && TREE_CODE (tparm) != TYPE_DECL)
15376 || (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
15377 && TREE_CODE (tparm) != TEMPLATE_DECL))
15380 if (TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
15382 /* ARG must be constructed from a template class or a template
15383 template parameter. */
15384 if (TREE_CODE (arg) != BOUND_TEMPLATE_TEMPLATE_PARM
15385 && !CLASSTYPE_SPECIALIZATION_OF_PRIMARY_TEMPLATE_P (arg))
15389 tree parmvec = TYPE_TI_ARGS (parm);
15390 tree argvec = INNERMOST_TEMPLATE_ARGS (TYPE_TI_ARGS (arg));
15391 tree full_argvec = add_to_template_args (targs, argvec);
15393 = DECL_INNERMOST_TEMPLATE_PARMS
15394 (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (parm));
15396 int parm_variadic_p = 0;
15398 /* The resolution to DR150 makes clear that default
15399 arguments for an N-argument may not be used to bind T
15400 to a template template parameter with fewer than N
15401 parameters. It is not safe to permit the binding of
15402 default arguments as an extension, as that may change
15403 the meaning of a conforming program. Consider:
15405 struct Dense { static const unsigned int dim = 1; };
15407 template <template <typename> class View,
15409 void operator+(float, View<Block> const&);
15411 template <typename Block,
15412 unsigned int Dim = Block::dim>
15413 struct Lvalue_proxy { operator float() const; };
15417 Lvalue_proxy<Dense> p;
15422 Here, if Lvalue_proxy is permitted to bind to View, then
15423 the global operator+ will be used; if they are not, the
15424 Lvalue_proxy will be converted to float. */
15425 if (coerce_template_parms (parm_parms,
15427 TYPE_TI_TEMPLATE (parm),
15429 /*require_all_args=*/true,
15430 /*use_default_args=*/false)
15431 == error_mark_node)
15434 /* Deduce arguments T, i from TT<T> or TT<i>.
15435 We check each element of PARMVEC and ARGVEC individually
15436 rather than the whole TREE_VEC since they can have
15437 different number of elements. */
15439 parmvec = expand_template_argument_pack (parmvec);
15440 argvec = expand_template_argument_pack (argvec);
15442 len = TREE_VEC_LENGTH (parmvec);
15444 /* Check if the parameters end in a pack, making them
15447 && PACK_EXPANSION_P (TREE_VEC_ELT (parmvec, len - 1)))
15448 parm_variadic_p = 1;
15450 if (TREE_VEC_LENGTH (argvec) < len - parm_variadic_p)
15453 for (i = 0; i < len - parm_variadic_p; ++i)
15455 if (unify (tparms, targs,
15456 TREE_VEC_ELT (parmvec, i),
15457 TREE_VEC_ELT (argvec, i),
15462 if (parm_variadic_p
15463 && unify_pack_expansion (tparms, targs,
15466 /*call_args_p=*/false,
15470 arg = TYPE_TI_TEMPLATE (arg);
15472 /* Fall through to deduce template name. */
15475 if (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
15476 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
15478 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
15480 /* Simple cases: Value already set, does match or doesn't. */
15481 if (targ != NULL_TREE && template_args_equal (targ, arg))
15488 /* If PARM is `const T' and ARG is only `int', we don't have
15489 a match unless we are allowing additional qualification.
15490 If ARG is `const int' and PARM is just `T' that's OK;
15491 that binds `const int' to `T'. */
15492 if (!check_cv_quals_for_unify (strict_in | UNIFY_ALLOW_LESS_CV_QUAL,
15496 /* Consider the case where ARG is `const volatile int' and
15497 PARM is `const T'. Then, T should be `volatile int'. */
15498 arg = cp_build_qualified_type_real
15499 (arg, cp_type_quals (arg) & ~cp_type_quals (parm), tf_none);
15500 if (arg == error_mark_node)
15503 /* Simple cases: Value already set, does match or doesn't. */
15504 if (targ != NULL_TREE && same_type_p (targ, arg))
15509 /* Make sure that ARG is not a variable-sized array. (Note
15510 that were talking about variable-sized arrays (like
15511 `int[n]'), rather than arrays of unknown size (like
15512 `int[]').) We'll get very confused by such a type since
15513 the bound of the array will not be computable in an
15514 instantiation. Besides, such types are not allowed in
15515 ISO C++, so we can do as we please here. */
15516 if (variably_modified_type_p (arg, NULL_TREE))
15519 /* Strip typedefs as in convert_template_argument. */
15520 arg = canonicalize_type_argument (arg, tf_none);
15523 /* If ARG is a parameter pack or an expansion, we cannot unify
15524 against it unless PARM is also a parameter pack. */
15525 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
15526 && !template_parameter_pack_p (parm))
15529 /* If the argument deduction results is a METHOD_TYPE,
15530 then there is a problem.
15531 METHOD_TYPE doesn't map to any real C++ type the result of
15532 the deduction can not be of that type. */
15533 if (TREE_CODE (arg) == METHOD_TYPE)
15536 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
15539 case TEMPLATE_PARM_INDEX:
15540 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
15541 if (tparm == error_mark_node)
15544 if (TEMPLATE_PARM_LEVEL (parm)
15545 != template_decl_level (tparm))
15546 /* The PARM is not one we're trying to unify. Just check
15547 to see if it matches ARG. */
15548 return !(TREE_CODE (arg) == TREE_CODE (parm)
15549 && cp_tree_equal (parm, arg));
15551 idx = TEMPLATE_PARM_IDX (parm);
15552 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
15555 return !cp_tree_equal (targ, arg);
15557 /* [temp.deduct.type] If, in the declaration of a function template
15558 with a non-type template-parameter, the non-type
15559 template-parameter is used in an expression in the function
15560 parameter-list and, if the corresponding template-argument is
15561 deduced, the template-argument type shall match the type of the
15562 template-parameter exactly, except that a template-argument
15563 deduced from an array bound may be of any integral type.
15564 The non-type parameter might use already deduced type parameters. */
15565 tparm = tsubst (TREE_TYPE (parm), targs, 0, NULL_TREE);
15566 if (!TREE_TYPE (arg))
15567 /* Template-parameter dependent expression. Just accept it for now.
15568 It will later be processed in convert_template_argument. */
15570 else if (same_type_p (TREE_TYPE (arg), tparm))
15572 else if ((strict & UNIFY_ALLOW_INTEGER)
15573 && (TREE_CODE (tparm) == INTEGER_TYPE
15574 || TREE_CODE (tparm) == BOOLEAN_TYPE))
15575 /* Convert the ARG to the type of PARM; the deduced non-type
15576 template argument must exactly match the types of the
15577 corresponding parameter. */
15578 arg = fold (build_nop (tparm, arg));
15579 else if (uses_template_parms (tparm))
15580 /* We haven't deduced the type of this parameter yet. Try again
15586 /* If ARG is a parameter pack or an expansion, we cannot unify
15587 against it unless PARM is also a parameter pack. */
15588 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
15589 && !TEMPLATE_PARM_PARAMETER_PACK (parm))
15592 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
15597 /* A pointer-to-member constant can be unified only with
15598 another constant. */
15599 if (TREE_CODE (arg) != PTRMEM_CST)
15602 /* Just unify the class member. It would be useless (and possibly
15603 wrong, depending on the strict flags) to unify also
15604 PTRMEM_CST_CLASS, because we want to be sure that both parm and
15605 arg refer to the same variable, even if through different
15606 classes. For instance:
15608 struct A { int x; };
15611 Unification of &A::x and &B::x must succeed. */
15612 return unify (tparms, targs, PTRMEM_CST_MEMBER (parm),
15613 PTRMEM_CST_MEMBER (arg), strict);
15618 if (TREE_CODE (arg) != POINTER_TYPE)
15621 /* [temp.deduct.call]
15623 A can be another pointer or pointer to member type that can
15624 be converted to the deduced A via a qualification
15625 conversion (_conv.qual_).
15627 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
15628 This will allow for additional cv-qualification of the
15629 pointed-to types if appropriate. */
15631 if (TREE_CODE (TREE_TYPE (arg)) == RECORD_TYPE)
15632 /* The derived-to-base conversion only persists through one
15633 level of pointers. */
15634 strict |= (strict_in & UNIFY_ALLOW_DERIVED);
15636 return unify (tparms, targs, TREE_TYPE (parm),
15637 TREE_TYPE (arg), strict);
15640 case REFERENCE_TYPE:
15641 if (TREE_CODE (arg) != REFERENCE_TYPE)
15643 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
15644 strict & UNIFY_ALLOW_MORE_CV_QUAL);
15647 if (TREE_CODE (arg) != ARRAY_TYPE)
15649 if ((TYPE_DOMAIN (parm) == NULL_TREE)
15650 != (TYPE_DOMAIN (arg) == NULL_TREE))
15652 if (TYPE_DOMAIN (parm) != NULL_TREE)
15659 /* Our representation of array types uses "N - 1" as the
15660 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
15661 not an integer constant. We cannot unify arbitrarily
15662 complex expressions, so we eliminate the MINUS_EXPRs
15664 parm_max = TYPE_MAX_VALUE (TYPE_DOMAIN (parm));
15665 parm_cst = TREE_CODE (parm_max) == INTEGER_CST;
15668 gcc_assert (TREE_CODE (parm_max) == MINUS_EXPR);
15669 parm_max = TREE_OPERAND (parm_max, 0);
15671 arg_max = TYPE_MAX_VALUE (TYPE_DOMAIN (arg));
15672 arg_cst = TREE_CODE (arg_max) == INTEGER_CST;
15675 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
15676 trying to unify the type of a variable with the type
15677 of a template parameter. For example:
15679 template <unsigned int N>
15680 void f (char (&) [N]);
15687 Here, the type of the ARG will be "int [g(i)]", and
15688 may be a SAVE_EXPR, etc. */
15689 if (TREE_CODE (arg_max) != MINUS_EXPR)
15691 arg_max = TREE_OPERAND (arg_max, 0);
15694 /* If only one of the bounds used a MINUS_EXPR, compensate
15695 by adding one to the other bound. */
15696 if (parm_cst && !arg_cst)
15697 parm_max = fold_build2_loc (input_location, PLUS_EXPR,
15701 else if (arg_cst && !parm_cst)
15702 arg_max = fold_build2_loc (input_location, PLUS_EXPR,
15707 if (unify (tparms, targs, parm_max, arg_max, UNIFY_ALLOW_INTEGER))
15710 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
15711 strict & UNIFY_ALLOW_MORE_CV_QUAL);
15718 case ENUMERAL_TYPE:
15720 if (TREE_CODE (arg) != TREE_CODE (parm))
15723 /* We have already checked cv-qualification at the top of the
15725 if (!same_type_ignoring_top_level_qualifiers_p (arg, parm))
15728 /* As far as unification is concerned, this wins. Later checks
15729 will invalidate it if necessary. */
15732 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
15733 /* Type INTEGER_CST can come from ordinary constant template args. */
15735 while (TREE_CODE (arg) == NOP_EXPR)
15736 arg = TREE_OPERAND (arg, 0);
15738 if (TREE_CODE (arg) != INTEGER_CST)
15740 return !tree_int_cst_equal (parm, arg);
15745 if (TREE_CODE (arg) != TREE_VEC)
15747 if (TREE_VEC_LENGTH (parm) != TREE_VEC_LENGTH (arg))
15749 for (i = 0; i < TREE_VEC_LENGTH (parm); ++i)
15750 if (unify (tparms, targs,
15751 TREE_VEC_ELT (parm, i), TREE_VEC_ELT (arg, i),
15759 if (TREE_CODE (arg) != TREE_CODE (parm))
15762 if (TYPE_PTRMEMFUNC_P (parm))
15764 if (!TYPE_PTRMEMFUNC_P (arg))
15767 return unify (tparms, targs,
15768 TYPE_PTRMEMFUNC_FN_TYPE (parm),
15769 TYPE_PTRMEMFUNC_FN_TYPE (arg),
15773 if (CLASSTYPE_TEMPLATE_INFO (parm))
15775 tree t = NULL_TREE;
15777 if (strict_in & UNIFY_ALLOW_DERIVED)
15779 /* First, we try to unify the PARM and ARG directly. */
15780 t = try_class_unification (tparms, targs,
15785 /* Fallback to the special case allowed in
15786 [temp.deduct.call]:
15788 If P is a class, and P has the form
15789 template-id, then A can be a derived class of
15790 the deduced A. Likewise, if P is a pointer to
15791 a class of the form template-id, A can be a
15792 pointer to a derived class pointed to by the
15794 t = get_template_base (tparms, targs, parm, arg);
15800 else if (CLASSTYPE_TEMPLATE_INFO (arg)
15801 && (CLASSTYPE_TI_TEMPLATE (parm)
15802 == CLASSTYPE_TI_TEMPLATE (arg)))
15803 /* Perhaps PARM is something like S<U> and ARG is S<int>.
15804 Then, we should unify `int' and `U'. */
15807 /* There's no chance of unification succeeding. */
15810 return unify (tparms, targs, CLASSTYPE_TI_ARGS (parm),
15811 CLASSTYPE_TI_ARGS (t), UNIFY_ALLOW_NONE);
15813 else if (!same_type_ignoring_top_level_qualifiers_p (parm, arg))
15818 case FUNCTION_TYPE:
15820 unsigned int nargs;
15825 if (TREE_CODE (arg) != TREE_CODE (parm))
15828 /* CV qualifications for methods can never be deduced, they must
15829 match exactly. We need to check them explicitly here,
15830 because type_unification_real treats them as any other
15831 cv-qualified parameter. */
15832 if (TREE_CODE (parm) == METHOD_TYPE
15833 && (!check_cv_quals_for_unify
15835 class_of_this_parm (arg),
15836 class_of_this_parm (parm))))
15839 if (unify (tparms, targs, TREE_TYPE (parm),
15840 TREE_TYPE (arg), UNIFY_ALLOW_NONE))
15843 nargs = list_length (TYPE_ARG_TYPES (arg));
15844 args = XALLOCAVEC (tree, nargs);
15845 for (a = TYPE_ARG_TYPES (arg), i = 0;
15846 a != NULL_TREE && a != void_list_node;
15847 a = TREE_CHAIN (a), ++i)
15848 args[i] = TREE_VALUE (a);
15851 return type_unification_real (tparms, targs, TYPE_ARG_TYPES (parm),
15852 args, nargs, 1, DEDUCE_EXACT,
15857 /* Unify a pointer to member with a pointer to member function, which
15858 deduces the type of the member as a function type. */
15859 if (TYPE_PTRMEMFUNC_P (arg))
15864 /* Check top-level cv qualifiers */
15865 if (!check_cv_quals_for_unify (UNIFY_ALLOW_NONE, arg, parm))
15868 if (unify (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
15869 TYPE_PTRMEMFUNC_OBJECT_TYPE (arg), UNIFY_ALLOW_NONE))
15872 /* Determine the type of the function we are unifying against. */
15873 method_type = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (arg));
15875 build_function_type (TREE_TYPE (method_type),
15876 TREE_CHAIN (TYPE_ARG_TYPES (method_type)));
15878 /* Extract the cv-qualifiers of the member function from the
15879 implicit object parameter and place them on the function
15880 type to be restored later. */
15881 fntype = apply_memfn_quals (fntype, type_memfn_quals (method_type));
15882 return unify (tparms, targs, TREE_TYPE (parm), fntype, strict);
15885 if (TREE_CODE (arg) != OFFSET_TYPE)
15887 if (unify (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
15888 TYPE_OFFSET_BASETYPE (arg), UNIFY_ALLOW_NONE))
15890 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
15894 if (DECL_TEMPLATE_PARM_P (parm))
15895 return unify (tparms, targs, DECL_INITIAL (parm), arg, strict);
15896 if (arg != integral_constant_value (parm))
15901 case TEMPLATE_DECL:
15902 /* Matched cases are handled by the ARG == PARM test above. */
15906 /* A non-type template parameter that is a variable should be a
15907 an integral constant, in which case, it whould have been
15908 folded into its (constant) value. So we should not be getting
15909 a variable here. */
15910 gcc_unreachable ();
15912 case TYPE_ARGUMENT_PACK:
15913 case NONTYPE_ARGUMENT_PACK:
15915 tree packed_parms = ARGUMENT_PACK_ARGS (parm);
15916 tree packed_args = ARGUMENT_PACK_ARGS (arg);
15917 int i, len = TREE_VEC_LENGTH (packed_parms);
15918 int argslen = TREE_VEC_LENGTH (packed_args);
15919 int parm_variadic_p = 0;
15921 for (i = 0; i < len; ++i)
15923 if (PACK_EXPANSION_P (TREE_VEC_ELT (packed_parms, i)))
15926 /* We can unify against something with a trailing
15928 parm_variadic_p = 1;
15930 /* Since there is something following the pack
15931 expansion, we cannot unify this template argument
15938 /* If we don't have enough arguments to satisfy the parameters
15939 (not counting the pack expression at the end), or we have
15940 too many arguments for a parameter list that doesn't end in
15941 a pack expression, we can't unify. */
15942 if (argslen < (len - parm_variadic_p)
15943 || (argslen > len && !parm_variadic_p))
15946 /* Unify all of the parameters that precede the (optional)
15947 pack expression. */
15948 for (i = 0; i < len - parm_variadic_p; ++i)
15950 if (unify (tparms, targs, TREE_VEC_ELT (packed_parms, i),
15951 TREE_VEC_ELT (packed_args, i), strict))
15955 if (parm_variadic_p)
15956 return unify_pack_expansion (tparms, targs,
15957 packed_parms, packed_args,
15958 strict, /*call_args_p=*/false,
15966 case DECLTYPE_TYPE:
15967 case UNDERLYING_TYPE:
15968 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
15969 or UNDERLYING_TYPE nodes. */
15973 /* Unification fails if we hit an error node. */
15977 /* An unresolved overload is a nondeduced context. */
15978 if (type_unknown_p (parm))
15980 gcc_assert (EXPR_P (parm));
15982 /* We must be looking at an expression. This can happen with
15986 void foo(S<I>, S<I + 2>);
15988 This is a "nondeduced context":
15992 The nondeduced contexts are:
15994 --A type that is a template-id in which one or more of
15995 the template-arguments is an expression that references
15996 a template-parameter.
15998 In these cases, we assume deduction succeeded, but don't
15999 actually infer any unifications. */
16001 if (!uses_template_parms (parm)
16002 && !template_args_equal (parm, arg))
16009 /* Note that DECL can be defined in this translation unit, if
16013 mark_definable (tree decl)
16016 DECL_NOT_REALLY_EXTERN (decl) = 1;
16017 FOR_EACH_CLONE (clone, decl)
16018 DECL_NOT_REALLY_EXTERN (clone) = 1;
16021 /* Called if RESULT is explicitly instantiated, or is a member of an
16022 explicitly instantiated class. */
16025 mark_decl_instantiated (tree result, int extern_p)
16027 SET_DECL_EXPLICIT_INSTANTIATION (result);
16029 /* If this entity has already been written out, it's too late to
16030 make any modifications. */
16031 if (TREE_ASM_WRITTEN (result))
16034 if (TREE_CODE (result) != FUNCTION_DECL)
16035 /* The TREE_PUBLIC flag for function declarations will have been
16036 set correctly by tsubst. */
16037 TREE_PUBLIC (result) = 1;
16039 /* This might have been set by an earlier implicit instantiation. */
16040 DECL_COMDAT (result) = 0;
16043 DECL_NOT_REALLY_EXTERN (result) = 0;
16046 mark_definable (result);
16047 /* Always make artificials weak. */
16048 if (DECL_ARTIFICIAL (result) && flag_weak)
16049 comdat_linkage (result);
16050 /* For WIN32 we also want to put explicit instantiations in
16051 linkonce sections. */
16052 else if (TREE_PUBLIC (result))
16053 maybe_make_one_only (result);
16056 /* If EXTERN_P, then this function will not be emitted -- unless
16057 followed by an explicit instantiation, at which point its linkage
16058 will be adjusted. If !EXTERN_P, then this function will be
16059 emitted here. In neither circumstance do we want
16060 import_export_decl to adjust the linkage. */
16061 DECL_INTERFACE_KNOWN (result) = 1;
16064 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
16065 important template arguments. If any are missing, we check whether
16066 they're important by using error_mark_node for substituting into any
16067 args that were used for partial ordering (the ones between ARGS and END)
16068 and seeing if it bubbles up. */
16071 check_undeduced_parms (tree targs, tree args, tree end)
16073 bool found = false;
16075 for (i = TREE_VEC_LENGTH (targs) - 1; i >= 0; --i)
16076 if (TREE_VEC_ELT (targs, i) == NULL_TREE)
16079 TREE_VEC_ELT (targs, i) = error_mark_node;
16083 for (; args != end; args = TREE_CHAIN (args))
16085 tree substed = tsubst (TREE_VALUE (args), targs, tf_none, NULL_TREE);
16086 if (substed == error_mark_node)
16093 /* Given two function templates PAT1 and PAT2, return:
16095 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
16096 -1 if PAT2 is more specialized than PAT1.
16097 0 if neither is more specialized.
16099 LEN indicates the number of parameters we should consider
16100 (defaulted parameters should not be considered).
16102 The 1998 std underspecified function template partial ordering, and
16103 DR214 addresses the issue. We take pairs of arguments, one from
16104 each of the templates, and deduce them against each other. One of
16105 the templates will be more specialized if all the *other*
16106 template's arguments deduce against its arguments and at least one
16107 of its arguments *does* *not* deduce against the other template's
16108 corresponding argument. Deduction is done as for class templates.
16109 The arguments used in deduction have reference and top level cv
16110 qualifiers removed. Iff both arguments were originally reference
16111 types *and* deduction succeeds in both directions, the template
16112 with the more cv-qualified argument wins for that pairing (if
16113 neither is more cv-qualified, they both are equal). Unlike regular
16114 deduction, after all the arguments have been deduced in this way,
16115 we do *not* verify the deduced template argument values can be
16116 substituted into non-deduced contexts.
16118 The logic can be a bit confusing here, because we look at deduce1 and
16119 targs1 to see if pat2 is at least as specialized, and vice versa; if we
16120 can find template arguments for pat1 to make arg1 look like arg2, that
16121 means that arg2 is at least as specialized as arg1. */
16124 more_specialized_fn (tree pat1, tree pat2, int len)
16126 tree decl1 = DECL_TEMPLATE_RESULT (pat1);
16127 tree decl2 = DECL_TEMPLATE_RESULT (pat2);
16128 tree targs1 = make_tree_vec (DECL_NTPARMS (pat1));
16129 tree targs2 = make_tree_vec (DECL_NTPARMS (pat2));
16130 tree tparms1 = DECL_INNERMOST_TEMPLATE_PARMS (pat1);
16131 tree tparms2 = DECL_INNERMOST_TEMPLATE_PARMS (pat2);
16132 tree args1 = TYPE_ARG_TYPES (TREE_TYPE (decl1));
16133 tree args2 = TYPE_ARG_TYPES (TREE_TYPE (decl2));
16134 tree origs1, origs2;
16135 bool lose1 = false;
16136 bool lose2 = false;
16138 /* Remove the this parameter from non-static member functions. If
16139 one is a non-static member function and the other is not a static
16140 member function, remove the first parameter from that function
16141 also. This situation occurs for operator functions where we
16142 locate both a member function (with this pointer) and non-member
16143 operator (with explicit first operand). */
16144 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl1))
16146 len--; /* LEN is the number of significant arguments for DECL1 */
16147 args1 = TREE_CHAIN (args1);
16148 if (!DECL_STATIC_FUNCTION_P (decl2))
16149 args2 = TREE_CHAIN (args2);
16151 else if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl2))
16153 args2 = TREE_CHAIN (args2);
16154 if (!DECL_STATIC_FUNCTION_P (decl1))
16157 args1 = TREE_CHAIN (args1);
16161 /* If only one is a conversion operator, they are unordered. */
16162 if (DECL_CONV_FN_P (decl1) != DECL_CONV_FN_P (decl2))
16165 /* Consider the return type for a conversion function */
16166 if (DECL_CONV_FN_P (decl1))
16168 args1 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl1)), args1);
16169 args2 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl2)), args2);
16173 processing_template_decl++;
16179 /* Stop when an ellipsis is seen. */
16180 && args1 != NULL_TREE && args2 != NULL_TREE)
16182 tree arg1 = TREE_VALUE (args1);
16183 tree arg2 = TREE_VALUE (args2);
16184 int deduce1, deduce2;
16188 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
16189 && TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
16191 /* When both arguments are pack expansions, we need only
16192 unify the patterns themselves. */
16193 arg1 = PACK_EXPANSION_PATTERN (arg1);
16194 arg2 = PACK_EXPANSION_PATTERN (arg2);
16196 /* This is the last comparison we need to do. */
16200 if (TREE_CODE (arg1) == REFERENCE_TYPE)
16202 arg1 = TREE_TYPE (arg1);
16203 quals1 = cp_type_quals (arg1);
16206 if (TREE_CODE (arg2) == REFERENCE_TYPE)
16208 arg2 = TREE_TYPE (arg2);
16209 quals2 = cp_type_quals (arg2);
16212 if ((quals1 < 0) != (quals2 < 0))
16214 /* Only of the args is a reference, see if we should apply
16215 array/function pointer decay to it. This is not part of
16216 DR214, but is, IMHO, consistent with the deduction rules
16217 for the function call itself, and with our earlier
16218 implementation of the underspecified partial ordering
16219 rules. (nathan). */
16222 switch (TREE_CODE (arg1))
16225 arg1 = TREE_TYPE (arg1);
16227 case FUNCTION_TYPE:
16228 arg1 = build_pointer_type (arg1);
16237 switch (TREE_CODE (arg2))
16240 arg2 = TREE_TYPE (arg2);
16242 case FUNCTION_TYPE:
16243 arg2 = build_pointer_type (arg2);
16252 arg1 = TYPE_MAIN_VARIANT (arg1);
16253 arg2 = TYPE_MAIN_VARIANT (arg2);
16255 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION)
16257 int i, len2 = list_length (args2);
16258 tree parmvec = make_tree_vec (1);
16259 tree argvec = make_tree_vec (len2);
16262 /* Setup the parameter vector, which contains only ARG1. */
16263 TREE_VEC_ELT (parmvec, 0) = arg1;
16265 /* Setup the argument vector, which contains the remaining
16267 for (i = 0; i < len2; i++, ta = TREE_CHAIN (ta))
16268 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
16270 deduce1 = !unify_pack_expansion (tparms1, targs1, parmvec,
16271 argvec, UNIFY_ALLOW_NONE,
16272 /*call_args_p=*/false,
16275 /* We cannot deduce in the other direction, because ARG1 is
16276 a pack expansion but ARG2 is not. */
16279 else if (TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
16281 int i, len1 = list_length (args1);
16282 tree parmvec = make_tree_vec (1);
16283 tree argvec = make_tree_vec (len1);
16286 /* Setup the parameter vector, which contains only ARG1. */
16287 TREE_VEC_ELT (parmvec, 0) = arg2;
16289 /* Setup the argument vector, which contains the remaining
16291 for (i = 0; i < len1; i++, ta = TREE_CHAIN (ta))
16292 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
16294 deduce2 = !unify_pack_expansion (tparms2, targs2, parmvec,
16295 argvec, UNIFY_ALLOW_NONE,
16296 /*call_args_p=*/false,
16299 /* We cannot deduce in the other direction, because ARG2 is
16300 a pack expansion but ARG1 is not.*/
16306 /* The normal case, where neither argument is a pack
16308 deduce1 = !unify (tparms1, targs1, arg1, arg2, UNIFY_ALLOW_NONE);
16309 deduce2 = !unify (tparms2, targs2, arg2, arg1, UNIFY_ALLOW_NONE);
16312 /* If we couldn't deduce arguments for tparms1 to make arg1 match
16313 arg2, then arg2 is not as specialized as arg1. */
16319 /* "If, for a given type, deduction succeeds in both directions
16320 (i.e., the types are identical after the transformations above)
16321 and if the type from the argument template is more cv-qualified
16322 than the type from the parameter template (as described above)
16323 that type is considered to be more specialized than the other. If
16324 neither type is more cv-qualified than the other then neither type
16325 is more specialized than the other." */
16327 if (deduce1 && deduce2
16328 && quals1 != quals2 && quals1 >= 0 && quals2 >= 0)
16330 if ((quals1 & quals2) == quals2)
16332 if ((quals1 & quals2) == quals1)
16336 if (lose1 && lose2)
16337 /* We've failed to deduce something in either direction.
16338 These must be unordered. */
16341 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
16342 || TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
16343 /* We have already processed all of the arguments in our
16344 handing of the pack expansion type. */
16347 args1 = TREE_CHAIN (args1);
16348 args2 = TREE_CHAIN (args2);
16351 /* "In most cases, all template parameters must have values in order for
16352 deduction to succeed, but for partial ordering purposes a template
16353 parameter may remain without a value provided it is not used in the
16354 types being used for partial ordering."
16356 Thus, if we are missing any of the targs1 we need to substitute into
16357 origs1, then pat2 is not as specialized as pat1. This can happen when
16358 there is a nondeduced context. */
16359 if (!lose2 && check_undeduced_parms (targs1, origs1, args1))
16361 if (!lose1 && check_undeduced_parms (targs2, origs2, args2))
16364 processing_template_decl--;
16366 /* All things being equal, if the next argument is a pack expansion
16367 for one function but not for the other, prefer the
16368 non-variadic function. FIXME this is bogus; see c++/41958. */
16370 && args1 && TREE_VALUE (args1)
16371 && args2 && TREE_VALUE (args2))
16373 lose1 = TREE_CODE (TREE_VALUE (args1)) == TYPE_PACK_EXPANSION;
16374 lose2 = TREE_CODE (TREE_VALUE (args2)) == TYPE_PACK_EXPANSION;
16377 if (lose1 == lose2)
16385 /* Determine which of two partial specializations is more specialized.
16387 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
16388 to the first partial specialization. The TREE_VALUE is the
16389 innermost set of template parameters for the partial
16390 specialization. PAT2 is similar, but for the second template.
16392 Return 1 if the first partial specialization is more specialized;
16393 -1 if the second is more specialized; 0 if neither is more
16396 See [temp.class.order] for information about determining which of
16397 two templates is more specialized. */
16400 more_specialized_class (tree pat1, tree pat2)
16405 bool any_deductions = false;
16407 tmpl1 = TREE_TYPE (pat1);
16408 tmpl2 = TREE_TYPE (pat2);
16410 /* Just like what happens for functions, if we are ordering between
16411 different class template specializations, we may encounter dependent
16412 types in the arguments, and we need our dependency check functions
16413 to behave correctly. */
16414 ++processing_template_decl;
16415 targs = get_class_bindings (TREE_VALUE (pat1),
16416 CLASSTYPE_TI_ARGS (tmpl1),
16417 CLASSTYPE_TI_ARGS (tmpl2));
16421 any_deductions = true;
16424 targs = get_class_bindings (TREE_VALUE (pat2),
16425 CLASSTYPE_TI_ARGS (tmpl2),
16426 CLASSTYPE_TI_ARGS (tmpl1));
16430 any_deductions = true;
16432 --processing_template_decl;
16434 /* In the case of a tie where at least one of the class templates
16435 has a parameter pack at the end, the template with the most
16436 non-packed parameters wins. */
16439 && (template_args_variadic_p (TREE_PURPOSE (pat1))
16440 || template_args_variadic_p (TREE_PURPOSE (pat2))))
16442 tree args1 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat1));
16443 tree args2 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat2));
16444 int len1 = TREE_VEC_LENGTH (args1);
16445 int len2 = TREE_VEC_LENGTH (args2);
16447 /* We don't count the pack expansion at the end. */
16448 if (template_args_variadic_p (TREE_PURPOSE (pat1)))
16450 if (template_args_variadic_p (TREE_PURPOSE (pat2)))
16455 else if (len1 < len2)
16462 /* Return the template arguments that will produce the function signature
16463 DECL from the function template FN, with the explicit template
16464 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
16465 also match. Return NULL_TREE if no satisfactory arguments could be
16469 get_bindings (tree fn, tree decl, tree explicit_args, bool check_rettype)
16471 int ntparms = DECL_NTPARMS (fn);
16472 tree targs = make_tree_vec (ntparms);
16474 tree decl_arg_types;
16476 unsigned int nargs, ix;
16479 /* Substitute the explicit template arguments into the type of DECL.
16480 The call to fn_type_unification will handle substitution into the
16482 decl_type = TREE_TYPE (decl);
16483 if (explicit_args && uses_template_parms (decl_type))
16486 tree converted_args;
16488 if (DECL_TEMPLATE_INFO (decl))
16489 tmpl = DECL_TI_TEMPLATE (decl);
16491 /* We can get here for some invalid specializations. */
16495 = coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
16496 explicit_args, NULL_TREE,
16498 /*require_all_args=*/false,
16499 /*use_default_args=*/false);
16500 if (converted_args == error_mark_node)
16503 decl_type = tsubst (decl_type, converted_args, tf_none, NULL_TREE);
16504 if (decl_type == error_mark_node)
16508 /* Never do unification on the 'this' parameter. */
16509 decl_arg_types = skip_artificial_parms_for (decl,
16510 TYPE_ARG_TYPES (decl_type));
16512 nargs = list_length (decl_arg_types);
16513 args = XALLOCAVEC (tree, nargs);
16514 for (arg = decl_arg_types, ix = 0;
16515 arg != NULL_TREE && arg != void_list_node;
16516 arg = TREE_CHAIN (arg), ++ix)
16517 args[ix] = TREE_VALUE (arg);
16519 if (fn_type_unification (fn, explicit_args, targs,
16521 (check_rettype || DECL_CONV_FN_P (fn)
16522 ? TREE_TYPE (decl_type) : NULL_TREE),
16523 DEDUCE_EXACT, LOOKUP_NORMAL))
16529 /* Return the innermost template arguments that, when applied to a
16530 template specialization whose innermost template parameters are
16531 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
16534 For example, suppose we have:
16536 template <class T, class U> struct S {};
16537 template <class T> struct S<T*, int> {};
16539 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
16540 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
16541 int}. The resulting vector will be {double}, indicating that `T'
16542 is bound to `double'. */
16545 get_class_bindings (tree tparms, tree spec_args, tree args)
16547 int i, ntparms = TREE_VEC_LENGTH (tparms);
16549 tree innermost_deduced_args;
16551 innermost_deduced_args = make_tree_vec (ntparms);
16552 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
16554 deduced_args = copy_node (args);
16555 SET_TMPL_ARGS_LEVEL (deduced_args,
16556 TMPL_ARGS_DEPTH (deduced_args),
16557 innermost_deduced_args);
16560 deduced_args = innermost_deduced_args;
16562 if (unify (tparms, deduced_args,
16563 INNERMOST_TEMPLATE_ARGS (spec_args),
16564 INNERMOST_TEMPLATE_ARGS (args),
16568 for (i = 0; i < ntparms; ++i)
16569 if (! TREE_VEC_ELT (innermost_deduced_args, i))
16572 /* Verify that nondeduced template arguments agree with the type
16573 obtained from argument deduction.
16577 struct A { typedef int X; };
16578 template <class T, class U> struct C {};
16579 template <class T> struct C<T, typename T::X> {};
16581 Then with the instantiation `C<A, int>', we can deduce that
16582 `T' is `A' but unify () does not check whether `typename T::X'
16584 spec_args = tsubst (spec_args, deduced_args, tf_none, NULL_TREE);
16585 if (spec_args == error_mark_node
16586 /* We only need to check the innermost arguments; the other
16587 arguments will always agree. */
16588 || !comp_template_args (INNERMOST_TEMPLATE_ARGS (spec_args),
16589 INNERMOST_TEMPLATE_ARGS (args)))
16592 /* Now that we have bindings for all of the template arguments,
16593 ensure that the arguments deduced for the template template
16594 parameters have compatible template parameter lists. See the use
16595 of template_template_parm_bindings_ok_p in fn_type_unification
16596 for more information. */
16597 if (!template_template_parm_bindings_ok_p (tparms, deduced_args))
16600 return deduced_args;
16603 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
16604 Return the TREE_LIST node with the most specialized template, if
16605 any. If there is no most specialized template, the error_mark_node
16608 Note that this function does not look at, or modify, the
16609 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
16610 returned is one of the elements of INSTANTIATIONS, callers may
16611 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
16612 and retrieve it from the value returned. */
16615 most_specialized_instantiation (tree templates)
16619 ++processing_template_decl;
16622 for (fn = TREE_CHAIN (templates); fn; fn = TREE_CHAIN (fn))
16626 if (get_bindings (TREE_VALUE (champ),
16627 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
16628 NULL_TREE, /*check_ret=*/true))
16631 if (get_bindings (TREE_VALUE (fn),
16632 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
16633 NULL_TREE, /*check_ret=*/true))
16640 /* Equally specialized, move to next function. If there
16641 is no next function, nothing's most specialized. */
16642 fn = TREE_CHAIN (fn);
16650 /* Now verify that champ is better than everything earlier in the
16651 instantiation list. */
16652 for (fn = templates; fn != champ; fn = TREE_CHAIN (fn))
16653 if (get_bindings (TREE_VALUE (champ),
16654 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
16655 NULL_TREE, /*check_ret=*/true)
16656 || !get_bindings (TREE_VALUE (fn),
16657 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
16658 NULL_TREE, /*check_ret=*/true))
16664 processing_template_decl--;
16667 return error_mark_node;
16672 /* If DECL is a specialization of some template, return the most
16673 general such template. Otherwise, returns NULL_TREE.
16675 For example, given:
16677 template <class T> struct S { template <class U> void f(U); };
16679 if TMPL is `template <class U> void S<int>::f(U)' this will return
16680 the full template. This function will not trace past partial
16681 specializations, however. For example, given in addition:
16683 template <class T> struct S<T*> { template <class U> void f(U); };
16685 if TMPL is `template <class U> void S<int*>::f(U)' this will return
16686 `template <class T> template <class U> S<T*>::f(U)'. */
16689 most_general_template (tree decl)
16691 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
16692 an immediate specialization. */
16693 if (TREE_CODE (decl) == FUNCTION_DECL)
16695 if (DECL_TEMPLATE_INFO (decl)) {
16696 decl = DECL_TI_TEMPLATE (decl);
16698 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
16699 template friend. */
16700 if (TREE_CODE (decl) != TEMPLATE_DECL)
16706 /* Look for more and more general templates. */
16707 while (DECL_TEMPLATE_INFO (decl))
16709 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
16710 (See cp-tree.h for details.) */
16711 if (TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
16714 if (CLASS_TYPE_P (TREE_TYPE (decl))
16715 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)))
16718 /* Stop if we run into an explicitly specialized class template. */
16719 if (!DECL_NAMESPACE_SCOPE_P (decl)
16720 && DECL_CONTEXT (decl)
16721 && CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (decl)))
16724 decl = DECL_TI_TEMPLATE (decl);
16730 /* Return the most specialized of the class template partial
16731 specializations of TMPL which can produce TYPE, a specialization of
16732 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
16733 a _TYPE node corresponding to the partial specialization, while the
16734 TREE_PURPOSE is the set of template arguments that must be
16735 substituted into the TREE_TYPE in order to generate TYPE.
16737 If the choice of partial specialization is ambiguous, a diagnostic
16738 is issued, and the error_mark_node is returned. If there are no
16739 partial specializations of TMPL matching TYPE, then NULL_TREE is
16743 most_specialized_class (tree type, tree tmpl, tsubst_flags_t complain)
16745 tree list = NULL_TREE;
16751 tree outer_args = NULL_TREE;
16753 tmpl = most_general_template (tmpl);
16754 args = CLASSTYPE_TI_ARGS (type);
16756 /* For determining which partial specialization to use, only the
16757 innermost args are interesting. */
16758 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
16760 outer_args = strip_innermost_template_args (args, 1);
16761 args = INNERMOST_TEMPLATE_ARGS (args);
16764 for (t = DECL_TEMPLATE_SPECIALIZATIONS (tmpl); t; t = TREE_CHAIN (t))
16766 tree partial_spec_args;
16768 tree parms = TREE_VALUE (t);
16770 partial_spec_args = CLASSTYPE_TI_ARGS (TREE_TYPE (t));
16772 ++processing_template_decl;
16778 /* Discard the outer levels of args, and then substitute in the
16779 template args from the enclosing class. */
16780 partial_spec_args = INNERMOST_TEMPLATE_ARGS (partial_spec_args);
16781 partial_spec_args = tsubst_template_args
16782 (partial_spec_args, outer_args, tf_none, NULL_TREE);
16784 /* PARMS already refers to just the innermost parms, but the
16785 template parms in partial_spec_args had their levels lowered
16786 by tsubst, so we need to do the same for the parm list. We
16787 can't just tsubst the TREE_VEC itself, as tsubst wants to
16788 treat a TREE_VEC as an argument vector. */
16789 parms = copy_node (parms);
16790 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
16791 TREE_VEC_ELT (parms, i) =
16792 tsubst (TREE_VEC_ELT (parms, i), outer_args, tf_none, NULL_TREE);
16796 partial_spec_args =
16797 coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
16798 add_to_template_args (outer_args,
16799 partial_spec_args),
16801 /*require_all_args=*/true,
16802 /*use_default_args=*/true);
16804 --processing_template_decl;
16806 if (partial_spec_args == error_mark_node)
16807 return error_mark_node;
16809 spec_args = get_class_bindings (parms,
16815 spec_args = add_to_template_args (outer_args, spec_args);
16816 list = tree_cons (spec_args, TREE_VALUE (t), list);
16817 TREE_TYPE (list) = TREE_TYPE (t);
16824 ambiguous_p = false;
16827 t = TREE_CHAIN (t);
16828 for (; t; t = TREE_CHAIN (t))
16830 fate = more_specialized_class (champ, t);
16837 t = TREE_CHAIN (t);
16840 ambiguous_p = true;
16849 for (t = list; t && t != champ; t = TREE_CHAIN (t))
16851 fate = more_specialized_class (champ, t);
16854 ambiguous_p = true;
16862 char *spaces = NULL;
16863 if (!(complain & tf_error))
16864 return error_mark_node;
16865 error ("ambiguous class template instantiation for %q#T", type);
16866 str = ngettext ("candidate is:", "candidates are:", list_length (list));
16867 for (t = list; t; t = TREE_CHAIN (t))
16869 error ("%s %+#T", spaces ? spaces : str, TREE_TYPE (t));
16870 spaces = spaces ? spaces : get_spaces (str);
16873 return error_mark_node;
16879 /* Explicitly instantiate DECL. */
16882 do_decl_instantiation (tree decl, tree storage)
16884 tree result = NULL_TREE;
16887 if (!decl || decl == error_mark_node)
16888 /* An error occurred, for which grokdeclarator has already issued
16889 an appropriate message. */
16891 else if (! DECL_LANG_SPECIFIC (decl))
16893 error ("explicit instantiation of non-template %q#D", decl);
16896 else if (TREE_CODE (decl) == VAR_DECL)
16898 /* There is an asymmetry here in the way VAR_DECLs and
16899 FUNCTION_DECLs are handled by grokdeclarator. In the case of
16900 the latter, the DECL we get back will be marked as a
16901 template instantiation, and the appropriate
16902 DECL_TEMPLATE_INFO will be set up. This does not happen for
16903 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
16904 should handle VAR_DECLs as it currently handles
16906 if (!DECL_CLASS_SCOPE_P (decl))
16908 error ("%qD is not a static data member of a class template", decl);
16911 result = lookup_field (DECL_CONTEXT (decl), DECL_NAME (decl), 0, false);
16912 if (!result || TREE_CODE (result) != VAR_DECL)
16914 error ("no matching template for %qD found", decl);
16917 if (!same_type_p (TREE_TYPE (result), TREE_TYPE (decl)))
16919 error ("type %qT for explicit instantiation %qD does not match "
16920 "declared type %qT", TREE_TYPE (result), decl,
16925 else if (TREE_CODE (decl) != FUNCTION_DECL)
16927 error ("explicit instantiation of %q#D", decl);
16933 /* Check for various error cases. Note that if the explicit
16934 instantiation is valid the RESULT will currently be marked as an
16935 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
16936 until we get here. */
16938 if (DECL_TEMPLATE_SPECIALIZATION (result))
16940 /* DR 259 [temp.spec].
16942 Both an explicit instantiation and a declaration of an explicit
16943 specialization shall not appear in a program unless the explicit
16944 instantiation follows a declaration of the explicit specialization.
16946 For a given set of template parameters, if an explicit
16947 instantiation of a template appears after a declaration of an
16948 explicit specialization for that template, the explicit
16949 instantiation has no effect. */
16952 else if (DECL_EXPLICIT_INSTANTIATION (result))
16956 No program shall explicitly instantiate any template more
16959 We check DECL_NOT_REALLY_EXTERN so as not to complain when
16960 the first instantiation was `extern' and the second is not,
16961 and EXTERN_P for the opposite case. */
16962 if (DECL_NOT_REALLY_EXTERN (result) && !extern_p)
16963 permerror (input_location, "duplicate explicit instantiation of %q#D", result);
16964 /* If an "extern" explicit instantiation follows an ordinary
16965 explicit instantiation, the template is instantiated. */
16969 else if (!DECL_IMPLICIT_INSTANTIATION (result))
16971 error ("no matching template for %qD found", result);
16974 else if (!DECL_TEMPLATE_INFO (result))
16976 permerror (input_location, "explicit instantiation of non-template %q#D", result);
16980 if (storage == NULL_TREE)
16982 else if (storage == ridpointers[(int) RID_EXTERN])
16984 if (!in_system_header && (cxx_dialect == cxx98))
16985 pedwarn (input_location, OPT_pedantic,
16986 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
16991 error ("storage class %qD applied to template instantiation", storage);
16993 check_explicit_instantiation_namespace (result);
16994 mark_decl_instantiated (result, extern_p);
16996 instantiate_decl (result, /*defer_ok=*/1,
16997 /*expl_inst_class_mem_p=*/false);
17001 mark_class_instantiated (tree t, int extern_p)
17003 SET_CLASSTYPE_EXPLICIT_INSTANTIATION (t);
17004 SET_CLASSTYPE_INTERFACE_KNOWN (t);
17005 CLASSTYPE_INTERFACE_ONLY (t) = extern_p;
17006 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (t)) = extern_p;
17009 CLASSTYPE_DEBUG_REQUESTED (t) = 1;
17010 rest_of_type_compilation (t, 1);
17014 /* Called from do_type_instantiation through binding_table_foreach to
17015 do recursive instantiation for the type bound in ENTRY. */
17017 bt_instantiate_type_proc (binding_entry entry, void *data)
17019 tree storage = *(tree *) data;
17021 if (MAYBE_CLASS_TYPE_P (entry->type)
17022 && !uses_template_parms (CLASSTYPE_TI_ARGS (entry->type)))
17023 do_type_instantiation (TYPE_MAIN_DECL (entry->type), storage, 0);
17026 /* Called from do_type_instantiation to instantiate a member
17027 (a member function or a static member variable) of an
17028 explicitly instantiated class template. */
17030 instantiate_class_member (tree decl, int extern_p)
17032 mark_decl_instantiated (decl, extern_p);
17034 instantiate_decl (decl, /*defer_ok=*/1,
17035 /*expl_inst_class_mem_p=*/true);
17038 /* Perform an explicit instantiation of template class T. STORAGE, if
17039 non-null, is the RID for extern, inline or static. COMPLAIN is
17040 nonzero if this is called from the parser, zero if called recursively,
17041 since the standard is unclear (as detailed below). */
17044 do_type_instantiation (tree t, tree storage, tsubst_flags_t complain)
17049 int previous_instantiation_extern_p = 0;
17051 if (TREE_CODE (t) == TYPE_DECL)
17054 if (! CLASS_TYPE_P (t) || ! CLASSTYPE_TEMPLATE_INFO (t))
17056 error ("explicit instantiation of non-template type %qT", t);
17062 if (!COMPLETE_TYPE_P (t))
17064 if (complain & tf_error)
17065 error ("explicit instantiation of %q#T before definition of template",
17070 if (storage != NULL_TREE)
17072 if (!in_system_header)
17074 if (storage == ridpointers[(int) RID_EXTERN])
17076 if (cxx_dialect == cxx98)
17077 pedwarn (input_location, OPT_pedantic,
17078 "ISO C++ 1998 forbids the use of %<extern%> on "
17079 "explicit instantiations");
17082 pedwarn (input_location, OPT_pedantic,
17083 "ISO C++ forbids the use of %qE"
17084 " on explicit instantiations", storage);
17087 if (storage == ridpointers[(int) RID_INLINE])
17089 else if (storage == ridpointers[(int) RID_EXTERN])
17091 else if (storage == ridpointers[(int) RID_STATIC])
17095 error ("storage class %qD applied to template instantiation",
17101 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (t))
17103 /* DR 259 [temp.spec].
17105 Both an explicit instantiation and a declaration of an explicit
17106 specialization shall not appear in a program unless the explicit
17107 instantiation follows a declaration of the explicit specialization.
17109 For a given set of template parameters, if an explicit
17110 instantiation of a template appears after a declaration of an
17111 explicit specialization for that template, the explicit
17112 instantiation has no effect. */
17115 else if (CLASSTYPE_EXPLICIT_INSTANTIATION (t))
17119 No program shall explicitly instantiate any template more
17122 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
17123 instantiation was `extern'. If EXTERN_P then the second is.
17124 These cases are OK. */
17125 previous_instantiation_extern_p = CLASSTYPE_INTERFACE_ONLY (t);
17127 if (!previous_instantiation_extern_p && !extern_p
17128 && (complain & tf_error))
17129 permerror (input_location, "duplicate explicit instantiation of %q#T", t);
17131 /* If we've already instantiated the template, just return now. */
17132 if (!CLASSTYPE_INTERFACE_ONLY (t))
17136 check_explicit_instantiation_namespace (TYPE_NAME (t));
17137 mark_class_instantiated (t, extern_p);
17145 /* In contrast to implicit instantiation, where only the
17146 declarations, and not the definitions, of members are
17147 instantiated, we have here:
17151 The explicit instantiation of a class template specialization
17152 implies the instantiation of all of its members not
17153 previously explicitly specialized in the translation unit
17154 containing the explicit instantiation.
17156 Of course, we can't instantiate member template classes, since
17157 we don't have any arguments for them. Note that the standard
17158 is unclear on whether the instantiation of the members are
17159 *explicit* instantiations or not. However, the most natural
17160 interpretation is that it should be an explicit instantiation. */
17163 for (tmp = TYPE_METHODS (t); tmp; tmp = DECL_CHAIN (tmp))
17164 if (TREE_CODE (tmp) == FUNCTION_DECL
17165 && DECL_TEMPLATE_INSTANTIATION (tmp))
17166 instantiate_class_member (tmp, extern_p);
17168 for (tmp = TYPE_FIELDS (t); tmp; tmp = DECL_CHAIN (tmp))
17169 if (TREE_CODE (tmp) == VAR_DECL && DECL_TEMPLATE_INSTANTIATION (tmp))
17170 instantiate_class_member (tmp, extern_p);
17172 if (CLASSTYPE_NESTED_UTDS (t))
17173 binding_table_foreach (CLASSTYPE_NESTED_UTDS (t),
17174 bt_instantiate_type_proc, &storage);
17178 /* Given a function DECL, which is a specialization of TMPL, modify
17179 DECL to be a re-instantiation of TMPL with the same template
17180 arguments. TMPL should be the template into which tsubst'ing
17181 should occur for DECL, not the most general template.
17183 One reason for doing this is a scenario like this:
17186 void f(const T&, int i);
17188 void g() { f(3, 7); }
17191 void f(const T& t, const int i) { }
17193 Note that when the template is first instantiated, with
17194 instantiate_template, the resulting DECL will have no name for the
17195 first parameter, and the wrong type for the second. So, when we go
17196 to instantiate the DECL, we regenerate it. */
17199 regenerate_decl_from_template (tree decl, tree tmpl)
17201 /* The arguments used to instantiate DECL, from the most general
17206 args = DECL_TI_ARGS (decl);
17207 code_pattern = DECL_TEMPLATE_RESULT (tmpl);
17209 /* Make sure that we can see identifiers, and compute access
17211 push_access_scope (decl);
17213 if (TREE_CODE (decl) == FUNCTION_DECL)
17221 args_depth = TMPL_ARGS_DEPTH (args);
17222 parms_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
17223 if (args_depth > parms_depth)
17224 args = get_innermost_template_args (args, parms_depth);
17226 specs = tsubst_exception_specification (TREE_TYPE (code_pattern),
17227 args, tf_error, NULL_TREE,
17228 /*defer_ok*/false);
17230 TREE_TYPE (decl) = build_exception_variant (TREE_TYPE (decl),
17233 /* Merge parameter declarations. */
17234 decl_parm = skip_artificial_parms_for (decl,
17235 DECL_ARGUMENTS (decl));
17237 = skip_artificial_parms_for (code_pattern,
17238 DECL_ARGUMENTS (code_pattern));
17239 while (decl_parm && !FUNCTION_PARAMETER_PACK_P (pattern_parm))
17244 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
17245 DECL_NAME (decl_parm) = DECL_NAME (pattern_parm);
17246 parm_type = tsubst (TREE_TYPE (pattern_parm), args, tf_error,
17248 parm_type = type_decays_to (parm_type);
17249 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
17250 TREE_TYPE (decl_parm) = parm_type;
17251 attributes = DECL_ATTRIBUTES (pattern_parm);
17252 if (DECL_ATTRIBUTES (decl_parm) != attributes)
17254 DECL_ATTRIBUTES (decl_parm) = attributes;
17255 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
17257 decl_parm = DECL_CHAIN (decl_parm);
17258 pattern_parm = DECL_CHAIN (pattern_parm);
17260 /* Merge any parameters that match with the function parameter
17262 if (pattern_parm && FUNCTION_PARAMETER_PACK_P (pattern_parm))
17265 tree expanded_types;
17266 /* Expand the TYPE_PACK_EXPANSION that provides the types for
17267 the parameters in this function parameter pack. */
17268 expanded_types = tsubst_pack_expansion (TREE_TYPE (pattern_parm),
17269 args, tf_error, NULL_TREE);
17270 len = TREE_VEC_LENGTH (expanded_types);
17271 for (i = 0; i < len; i++)
17276 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
17277 /* Rename the parameter to include the index. */
17278 DECL_NAME (decl_parm) =
17279 make_ith_pack_parameter_name (DECL_NAME (pattern_parm), i);
17280 parm_type = TREE_VEC_ELT (expanded_types, i);
17281 parm_type = type_decays_to (parm_type);
17282 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
17283 TREE_TYPE (decl_parm) = parm_type;
17284 attributes = DECL_ATTRIBUTES (pattern_parm);
17285 if (DECL_ATTRIBUTES (decl_parm) != attributes)
17287 DECL_ATTRIBUTES (decl_parm) = attributes;
17288 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
17290 decl_parm = DECL_CHAIN (decl_parm);
17293 /* Merge additional specifiers from the CODE_PATTERN. */
17294 if (DECL_DECLARED_INLINE_P (code_pattern)
17295 && !DECL_DECLARED_INLINE_P (decl))
17296 DECL_DECLARED_INLINE_P (decl) = 1;
17298 else if (TREE_CODE (decl) == VAR_DECL)
17300 DECL_INITIAL (decl) =
17301 tsubst_expr (DECL_INITIAL (code_pattern), args,
17302 tf_error, DECL_TI_TEMPLATE (decl),
17303 /*integral_constant_expression_p=*/false);
17304 if (VAR_HAD_UNKNOWN_BOUND (decl))
17305 TREE_TYPE (decl) = tsubst (TREE_TYPE (code_pattern), args,
17306 tf_error, DECL_TI_TEMPLATE (decl));
17309 gcc_unreachable ();
17311 pop_access_scope (decl);
17314 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
17315 substituted to get DECL. */
17318 template_for_substitution (tree decl)
17320 tree tmpl = DECL_TI_TEMPLATE (decl);
17322 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
17323 for the instantiation. This is not always the most general
17324 template. Consider, for example:
17327 struct S { template <class U> void f();
17328 template <> void f<int>(); };
17330 and an instantiation of S<double>::f<int>. We want TD to be the
17331 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
17332 while (/* An instantiation cannot have a definition, so we need a
17333 more general template. */
17334 DECL_TEMPLATE_INSTANTIATION (tmpl)
17335 /* We must also deal with friend templates. Given:
17337 template <class T> struct S {
17338 template <class U> friend void f() {};
17341 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
17342 so far as the language is concerned, but that's still
17343 where we get the pattern for the instantiation from. On
17344 other hand, if the definition comes outside the class, say:
17346 template <class T> struct S {
17347 template <class U> friend void f();
17349 template <class U> friend void f() {}
17351 we don't need to look any further. That's what the check for
17352 DECL_INITIAL is for. */
17353 || (TREE_CODE (decl) == FUNCTION_DECL
17354 && DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION (tmpl)
17355 && !DECL_INITIAL (DECL_TEMPLATE_RESULT (tmpl))))
17357 /* The present template, TD, should not be a definition. If it
17358 were a definition, we should be using it! Note that we
17359 cannot restructure the loop to just keep going until we find
17360 a template with a definition, since that might go too far if
17361 a specialization was declared, but not defined. */
17362 gcc_assert (TREE_CODE (decl) != VAR_DECL
17363 || DECL_IN_AGGR_P (DECL_TEMPLATE_RESULT (tmpl)));
17365 /* Fetch the more general template. */
17366 tmpl = DECL_TI_TEMPLATE (tmpl);
17372 /* Returns true if we need to instantiate this template instance even if we
17373 know we aren't going to emit it.. */
17376 always_instantiate_p (tree decl)
17378 /* We always instantiate inline functions so that we can inline them. An
17379 explicit instantiation declaration prohibits implicit instantiation of
17380 non-inline functions. With high levels of optimization, we would
17381 normally inline non-inline functions -- but we're not allowed to do
17382 that for "extern template" functions. Therefore, we check
17383 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
17384 return ((TREE_CODE (decl) == FUNCTION_DECL
17385 && DECL_DECLARED_INLINE_P (decl))
17386 /* And we need to instantiate static data members so that
17387 their initializers are available in integral constant
17389 || (TREE_CODE (decl) == VAR_DECL
17390 && decl_maybe_constant_var_p (decl)));
17393 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
17394 instantiate it now, modifying TREE_TYPE (fn). */
17397 maybe_instantiate_noexcept (tree fn)
17399 tree fntype, spec, noex, clone;
17401 if (DECL_CLONED_FUNCTION_P (fn))
17402 fn = DECL_CLONED_FUNCTION (fn);
17403 fntype = TREE_TYPE (fn);
17404 spec = TYPE_RAISES_EXCEPTIONS (fntype);
17406 if (!DEFERRED_NOEXCEPT_SPEC_P (spec))
17409 noex = TREE_PURPOSE (spec);
17411 if (TREE_CODE (noex) == DEFERRED_NOEXCEPT)
17413 push_tinst_level (fn);
17414 push_access_scope (fn);
17415 input_location = DECL_SOURCE_LOCATION (fn);
17416 noex = tsubst_copy_and_build (DEFERRED_NOEXCEPT_PATTERN (noex),
17417 DEFERRED_NOEXCEPT_ARGS (noex),
17418 tf_warning_or_error, fn, /*function_p=*/false,
17419 /*integral_constant_expression_p=*/true);
17420 pop_access_scope (fn);
17421 pop_tinst_level ();
17422 spec = build_noexcept_spec (noex, tf_warning_or_error);
17423 if (spec == error_mark_node)
17424 spec = noexcept_false_spec;
17428 /* This is an implicitly declared function, so NOEX is a list of
17429 other functions to evaluate and merge. */
17431 spec = noexcept_true_spec;
17432 for (elt = noex; elt; elt = OVL_NEXT (elt))
17434 tree fn = OVL_CURRENT (elt);
17436 maybe_instantiate_noexcept (fn);
17437 subspec = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (fn));
17438 spec = merge_exception_specifiers (spec, subspec, NULL_TREE);
17442 TREE_TYPE (fn) = build_exception_variant (fntype, spec);
17444 FOR_EACH_CLONE (clone, fn)
17446 if (TREE_TYPE (clone) == fntype)
17447 TREE_TYPE (clone) = TREE_TYPE (fn);
17449 TREE_TYPE (clone) = build_exception_variant (TREE_TYPE (clone), spec);
17453 /* Produce the definition of D, a _DECL generated from a template. If
17454 DEFER_OK is nonzero, then we don't have to actually do the
17455 instantiation now; we just have to do it sometime. Normally it is
17456 an error if this is an explicit instantiation but D is undefined.
17457 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
17458 explicitly instantiated class template. */
17461 instantiate_decl (tree d, int defer_ok,
17462 bool expl_inst_class_mem_p)
17464 tree tmpl = DECL_TI_TEMPLATE (d);
17471 bool pattern_defined;
17473 location_t saved_loc = input_location;
17476 /* This function should only be used to instantiate templates for
17477 functions and static member variables. */
17478 gcc_assert (TREE_CODE (d) == FUNCTION_DECL
17479 || TREE_CODE (d) == VAR_DECL);
17481 /* Variables are never deferred; if instantiation is required, they
17482 are instantiated right away. That allows for better code in the
17483 case that an expression refers to the value of the variable --
17484 if the variable has a constant value the referring expression can
17485 take advantage of that fact. */
17486 if (TREE_CODE (d) == VAR_DECL
17487 || DECL_DECLARED_CONSTEXPR_P (d))
17490 /* Don't instantiate cloned functions. Instead, instantiate the
17491 functions they cloned. */
17492 if (TREE_CODE (d) == FUNCTION_DECL && DECL_CLONED_FUNCTION_P (d))
17493 d = DECL_CLONED_FUNCTION (d);
17495 if (DECL_TEMPLATE_INSTANTIATED (d)
17496 || DECL_TEMPLATE_SPECIALIZATION (d))
17497 /* D has already been instantiated or explicitly specialized, so
17498 there's nothing for us to do here.
17500 It might seem reasonable to check whether or not D is an explicit
17501 instantiation, and, if so, stop here. But when an explicit
17502 instantiation is deferred until the end of the compilation,
17503 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
17504 the instantiation. */
17507 /* Check to see whether we know that this template will be
17508 instantiated in some other file, as with "extern template"
17510 external_p = (DECL_INTERFACE_KNOWN (d) && DECL_REALLY_EXTERN (d));
17512 /* In general, we do not instantiate such templates. */
17513 if (external_p && !always_instantiate_p (d))
17516 gen_tmpl = most_general_template (tmpl);
17517 gen_args = DECL_TI_ARGS (d);
17519 if (tmpl != gen_tmpl)
17520 /* We should already have the extra args. */
17521 gcc_assert (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (gen_tmpl))
17522 == TMPL_ARGS_DEPTH (gen_args));
17523 /* And what's in the hash table should match D. */
17524 gcc_assert ((spec = retrieve_specialization (gen_tmpl, gen_args, 0)) == d
17525 || spec == NULL_TREE);
17527 /* This needs to happen before any tsubsting. */
17528 if (! push_tinst_level (d))
17531 timevar_push (TV_TEMPLATE_INST);
17533 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
17534 for the instantiation. */
17535 td = template_for_substitution (d);
17536 code_pattern = DECL_TEMPLATE_RESULT (td);
17538 /* We should never be trying to instantiate a member of a class
17539 template or partial specialization. */
17540 gcc_assert (d != code_pattern);
17542 if ((DECL_NAMESPACE_SCOPE_P (d) && !DECL_INITIALIZED_IN_CLASS_P (d))
17543 || DECL_TEMPLATE_SPECIALIZATION (td))
17544 /* In the case of a friend template whose definition is provided
17545 outside the class, we may have too many arguments. Drop the
17546 ones we don't need. The same is true for specializations. */
17547 args = get_innermost_template_args
17548 (gen_args, TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (td)));
17552 if (TREE_CODE (d) == FUNCTION_DECL)
17553 pattern_defined = (DECL_SAVED_TREE (code_pattern) != NULL_TREE
17554 || DECL_DEFAULTED_OUTSIDE_CLASS_P (code_pattern));
17556 pattern_defined = ! DECL_IN_AGGR_P (code_pattern);
17558 /* We may be in the middle of deferred access check. Disable it now. */
17559 push_deferring_access_checks (dk_no_deferred);
17561 /* Unless an explicit instantiation directive has already determined
17562 the linkage of D, remember that a definition is available for
17564 if (pattern_defined
17565 && !DECL_INTERFACE_KNOWN (d)
17566 && !DECL_NOT_REALLY_EXTERN (d))
17567 mark_definable (d);
17569 DECL_SOURCE_LOCATION (td) = DECL_SOURCE_LOCATION (code_pattern);
17570 DECL_SOURCE_LOCATION (d) = DECL_SOURCE_LOCATION (code_pattern);
17571 input_location = DECL_SOURCE_LOCATION (d);
17573 /* If D is a member of an explicitly instantiated class template,
17574 and no definition is available, treat it like an implicit
17576 if (!pattern_defined && expl_inst_class_mem_p
17577 && DECL_EXPLICIT_INSTANTIATION (d))
17579 /* Leave linkage flags alone on instantiations with anonymous
17581 if (TREE_PUBLIC (d))
17583 DECL_NOT_REALLY_EXTERN (d) = 0;
17584 DECL_INTERFACE_KNOWN (d) = 0;
17586 SET_DECL_IMPLICIT_INSTANTIATION (d);
17589 if (TREE_CODE (d) == FUNCTION_DECL)
17590 maybe_instantiate_noexcept (d);
17592 /* Recheck the substitutions to obtain any warning messages
17593 about ignoring cv qualifiers. Don't do this for artificial decls,
17594 as it breaks the context-sensitive substitution for lambda op(). */
17595 if (!defer_ok && !DECL_ARTIFICIAL (d))
17597 tree gen = DECL_TEMPLATE_RESULT (gen_tmpl);
17598 tree type = TREE_TYPE (gen);
17600 /* Make sure that we can see identifiers, and compute access
17601 correctly. D is already the target FUNCTION_DECL with the
17603 push_access_scope (d);
17605 if (TREE_CODE (gen) == FUNCTION_DECL)
17607 tsubst (DECL_ARGUMENTS (gen), gen_args, tf_warning_or_error, d);
17608 tsubst_exception_specification (type, gen_args, tf_warning_or_error,
17609 d, /*defer_ok*/true);
17610 /* Don't simply tsubst the function type, as that will give
17611 duplicate warnings about poor parameter qualifications.
17612 The function arguments are the same as the decl_arguments
17613 without the top level cv qualifiers. */
17614 type = TREE_TYPE (type);
17616 tsubst (type, gen_args, tf_warning_or_error, d);
17618 pop_access_scope (d);
17621 /* Defer all other templates, unless we have been explicitly
17622 forbidden from doing so. */
17623 if (/* If there is no definition, we cannot instantiate the
17626 /* If it's OK to postpone instantiation, do so. */
17628 /* If this is a static data member that will be defined
17629 elsewhere, we don't want to instantiate the entire data
17630 member, but we do want to instantiate the initializer so that
17631 we can substitute that elsewhere. */
17632 || (external_p && TREE_CODE (d) == VAR_DECL))
17634 /* The definition of the static data member is now required so
17635 we must substitute the initializer. */
17636 if (TREE_CODE (d) == VAR_DECL
17637 && !DECL_INITIAL (d)
17638 && DECL_INITIAL (code_pattern))
17642 bool const_init = false;
17644 ns = decl_namespace_context (d);
17645 push_nested_namespace (ns);
17646 push_nested_class (DECL_CONTEXT (d));
17647 init = tsubst_expr (DECL_INITIAL (code_pattern),
17649 tf_warning_or_error, NULL_TREE,
17650 /*integral_constant_expression_p=*/false);
17651 /* Make sure the initializer is still constant, in case of
17652 circular dependency (template/instantiate6.C). */
17654 = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (code_pattern);
17655 cp_finish_decl (d, init, /*init_const_expr_p=*/const_init,
17656 /*asmspec_tree=*/NULL_TREE,
17657 LOOKUP_ONLYCONVERTING);
17658 pop_nested_class ();
17659 pop_nested_namespace (ns);
17662 /* We restore the source position here because it's used by
17663 add_pending_template. */
17664 input_location = saved_loc;
17666 if (at_eof && !pattern_defined
17667 && DECL_EXPLICIT_INSTANTIATION (d)
17668 && DECL_NOT_REALLY_EXTERN (d))
17671 The definition of a non-exported function template, a
17672 non-exported member function template, or a non-exported
17673 member function or static data member of a class template
17674 shall be present in every translation unit in which it is
17675 explicitly instantiated. */
17676 permerror (input_location, "explicit instantiation of %qD "
17677 "but no definition available", d);
17679 /* If we're in unevaluated context, we just wanted to get the
17680 constant value; this isn't an odr use, so don't queue
17681 a full instantiation. */
17682 if (cp_unevaluated_operand != 0)
17684 /* ??? Historically, we have instantiated inline functions, even
17685 when marked as "extern template". */
17686 if (!(external_p && TREE_CODE (d) == VAR_DECL))
17687 add_pending_template (d);
17690 /* Tell the repository that D is available in this translation unit
17691 -- and see if it is supposed to be instantiated here. */
17692 if (TREE_PUBLIC (d) && !DECL_REALLY_EXTERN (d) && !repo_emit_p (d))
17694 /* In a PCH file, despite the fact that the repository hasn't
17695 requested instantiation in the PCH it is still possible that
17696 an instantiation will be required in a file that includes the
17699 add_pending_template (d);
17700 /* Instantiate inline functions so that the inliner can do its
17701 job, even though we'll not be emitting a copy of this
17703 if (!(TREE_CODE (d) == FUNCTION_DECL && possibly_inlined_p (d)))
17707 need_push = !cfun || !global_bindings_p ();
17709 push_to_top_level ();
17711 /* Mark D as instantiated so that recursive calls to
17712 instantiate_decl do not try to instantiate it again. */
17713 DECL_TEMPLATE_INSTANTIATED (d) = 1;
17715 /* Regenerate the declaration in case the template has been modified
17716 by a subsequent redeclaration. */
17717 regenerate_decl_from_template (d, td);
17719 /* We already set the file and line above. Reset them now in case
17720 they changed as a result of calling regenerate_decl_from_template. */
17721 input_location = DECL_SOURCE_LOCATION (d);
17723 if (TREE_CODE (d) == VAR_DECL)
17726 bool const_init = false;
17728 /* Clear out DECL_RTL; whatever was there before may not be right
17729 since we've reset the type of the declaration. */
17730 SET_DECL_RTL (d, NULL);
17731 DECL_IN_AGGR_P (d) = 0;
17733 /* The initializer is placed in DECL_INITIAL by
17734 regenerate_decl_from_template so we don't need to
17735 push/pop_access_scope again here. Pull it out so that
17736 cp_finish_decl can process it. */
17737 init = DECL_INITIAL (d);
17738 DECL_INITIAL (d) = NULL_TREE;
17739 DECL_INITIALIZED_P (d) = 0;
17741 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
17742 initializer. That function will defer actual emission until
17743 we have a chance to determine linkage. */
17744 DECL_EXTERNAL (d) = 0;
17746 /* Enter the scope of D so that access-checking works correctly. */
17747 push_nested_class (DECL_CONTEXT (d));
17748 const_init = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (code_pattern);
17749 cp_finish_decl (d, init, const_init, NULL_TREE, 0);
17750 pop_nested_class ();
17752 else if (TREE_CODE (d) == FUNCTION_DECL && DECL_DEFAULTED_FN (code_pattern))
17753 synthesize_method (d);
17754 else if (TREE_CODE (d) == FUNCTION_DECL)
17756 htab_t saved_local_specializations;
17761 /* Save away the current list, in case we are instantiating one
17762 template from within the body of another. */
17763 saved_local_specializations = local_specializations;
17765 /* Set up the list of local specializations. */
17766 local_specializations = htab_create (37,
17767 hash_local_specialization,
17768 eq_local_specializations,
17771 /* Set up context. */
17772 start_preparsed_function (d, NULL_TREE, SF_PRE_PARSED);
17774 /* Create substitution entries for the parameters. */
17775 subst_decl = DECL_TEMPLATE_RESULT (template_for_substitution (d));
17776 tmpl_parm = DECL_ARGUMENTS (subst_decl);
17777 spec_parm = DECL_ARGUMENTS (d);
17778 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (d))
17780 register_local_specialization (spec_parm, tmpl_parm);
17781 spec_parm = skip_artificial_parms_for (d, spec_parm);
17782 tmpl_parm = skip_artificial_parms_for (subst_decl, tmpl_parm);
17784 while (tmpl_parm && !FUNCTION_PARAMETER_PACK_P (tmpl_parm))
17786 register_local_specialization (spec_parm, tmpl_parm);
17787 tmpl_parm = DECL_CHAIN (tmpl_parm);
17788 spec_parm = DECL_CHAIN (spec_parm);
17790 if (tmpl_parm && FUNCTION_PARAMETER_PACK_P (tmpl_parm))
17792 /* Register the (value) argument pack as a specialization of
17793 TMPL_PARM, then move on. */
17794 tree argpack = make_fnparm_pack (spec_parm);
17795 register_local_specialization (argpack, tmpl_parm);
17796 tmpl_parm = DECL_CHAIN (tmpl_parm);
17797 spec_parm = NULL_TREE;
17799 gcc_assert (!spec_parm);
17801 /* Substitute into the body of the function. */
17802 tsubst_expr (DECL_SAVED_TREE (code_pattern), args,
17803 tf_warning_or_error, tmpl,
17804 /*integral_constant_expression_p=*/false);
17806 /* Set the current input_location to the end of the function
17807 so that finish_function knows where we are. */
17808 input_location = DECL_STRUCT_FUNCTION (code_pattern)->function_end_locus;
17810 /* We don't need the local specializations any more. */
17811 htab_delete (local_specializations);
17812 local_specializations = saved_local_specializations;
17814 /* Finish the function. */
17815 d = finish_function (0);
17816 expand_or_defer_fn (d);
17819 /* We're not deferring instantiation any more. */
17820 TI_PENDING_TEMPLATE_FLAG (DECL_TEMPLATE_INFO (d)) = 0;
17823 pop_from_top_level ();
17826 input_location = saved_loc;
17827 pop_deferring_access_checks ();
17828 pop_tinst_level ();
17830 timevar_pop (TV_TEMPLATE_INST);
17835 /* Run through the list of templates that we wish we could
17836 instantiate, and instantiate any we can. RETRIES is the
17837 number of times we retry pending template instantiation. */
17840 instantiate_pending_templates (int retries)
17843 location_t saved_loc = input_location;
17845 /* Instantiating templates may trigger vtable generation. This in turn
17846 may require further template instantiations. We place a limit here
17847 to avoid infinite loop. */
17848 if (pending_templates && retries >= max_tinst_depth)
17850 tree decl = pending_templates->tinst->decl;
17852 error ("template instantiation depth exceeds maximum of %d"
17853 " instantiating %q+D, possibly from virtual table generation"
17854 " (use -ftemplate-depth= to increase the maximum)",
17855 max_tinst_depth, decl);
17856 if (TREE_CODE (decl) == FUNCTION_DECL)
17857 /* Pretend that we defined it. */
17858 DECL_INITIAL (decl) = error_mark_node;
17864 struct pending_template **t = &pending_templates;
17865 struct pending_template *last = NULL;
17869 tree instantiation = reopen_tinst_level ((*t)->tinst);
17870 bool complete = false;
17872 if (TYPE_P (instantiation))
17876 if (!COMPLETE_TYPE_P (instantiation))
17878 instantiate_class_template (instantiation);
17879 if (CLASSTYPE_TEMPLATE_INSTANTIATION (instantiation))
17880 for (fn = TYPE_METHODS (instantiation);
17882 fn = TREE_CHAIN (fn))
17883 if (! DECL_ARTIFICIAL (fn))
17884 instantiate_decl (fn,
17886 /*expl_inst_class_mem_p=*/false);
17887 if (COMPLETE_TYPE_P (instantiation))
17891 complete = COMPLETE_TYPE_P (instantiation);
17895 if (!DECL_TEMPLATE_SPECIALIZATION (instantiation)
17896 && !DECL_TEMPLATE_INSTANTIATED (instantiation))
17899 = instantiate_decl (instantiation,
17901 /*expl_inst_class_mem_p=*/false);
17902 if (DECL_TEMPLATE_INSTANTIATED (instantiation))
17906 complete = (DECL_TEMPLATE_SPECIALIZATION (instantiation)
17907 || DECL_TEMPLATE_INSTANTIATED (instantiation));
17911 /* If INSTANTIATION has been instantiated, then we don't
17912 need to consider it again in the future. */
17920 current_tinst_level = NULL;
17922 last_pending_template = last;
17924 while (reconsider);
17926 input_location = saved_loc;
17929 /* Substitute ARGVEC into T, which is a list of initializers for
17930 either base class or a non-static data member. The TREE_PURPOSEs
17931 are DECLs, and the TREE_VALUEs are the initializer values. Used by
17932 instantiate_decl. */
17935 tsubst_initializer_list (tree t, tree argvec)
17937 tree inits = NULL_TREE;
17939 for (; t; t = TREE_CHAIN (t))
17943 tree expanded_bases = NULL_TREE;
17944 tree expanded_arguments = NULL_TREE;
17947 if (TREE_CODE (TREE_PURPOSE (t)) == TYPE_PACK_EXPANSION)
17952 /* Expand the base class expansion type into separate base
17954 expanded_bases = tsubst_pack_expansion (TREE_PURPOSE (t), argvec,
17955 tf_warning_or_error,
17957 if (expanded_bases == error_mark_node)
17960 /* We'll be building separate TREE_LISTs of arguments for
17962 len = TREE_VEC_LENGTH (expanded_bases);
17963 expanded_arguments = make_tree_vec (len);
17964 for (i = 0; i < len; i++)
17965 TREE_VEC_ELT (expanded_arguments, i) = NULL_TREE;
17967 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
17968 expand each argument in the TREE_VALUE of t. */
17969 expr = make_node (EXPR_PACK_EXPANSION);
17970 PACK_EXPANSION_PARAMETER_PACKS (expr) =
17971 PACK_EXPANSION_PARAMETER_PACKS (TREE_PURPOSE (t));
17973 if (TREE_VALUE (t) == void_type_node)
17974 /* VOID_TYPE_NODE is used to indicate
17975 value-initialization. */
17977 for (i = 0; i < len; i++)
17978 TREE_VEC_ELT (expanded_arguments, i) = void_type_node;
17982 /* Substitute parameter packs into each argument in the
17984 in_base_initializer = 1;
17985 for (arg = TREE_VALUE (t); arg; arg = TREE_CHAIN (arg))
17987 tree expanded_exprs;
17989 /* Expand the argument. */
17990 SET_PACK_EXPANSION_PATTERN (expr, TREE_VALUE (arg));
17992 = tsubst_pack_expansion (expr, argvec,
17993 tf_warning_or_error,
17995 if (expanded_exprs == error_mark_node)
17998 /* Prepend each of the expanded expressions to the
17999 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
18000 for (i = 0; i < len; i++)
18002 TREE_VEC_ELT (expanded_arguments, i) =
18003 tree_cons (NULL_TREE,
18004 TREE_VEC_ELT (expanded_exprs, i),
18005 TREE_VEC_ELT (expanded_arguments, i));
18008 in_base_initializer = 0;
18010 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
18011 since we built them backwards. */
18012 for (i = 0; i < len; i++)
18014 TREE_VEC_ELT (expanded_arguments, i) =
18015 nreverse (TREE_VEC_ELT (expanded_arguments, i));
18020 for (i = 0; i < len; ++i)
18022 if (expanded_bases)
18024 decl = TREE_VEC_ELT (expanded_bases, i);
18025 decl = expand_member_init (decl);
18026 init = TREE_VEC_ELT (expanded_arguments, i);
18030 decl = tsubst_copy (TREE_PURPOSE (t), argvec,
18031 tf_warning_or_error, NULL_TREE);
18033 decl = expand_member_init (decl);
18034 if (decl && !DECL_P (decl))
18035 in_base_initializer = 1;
18037 init = TREE_VALUE (t);
18038 if (init != void_type_node)
18039 init = tsubst_expr (init, argvec,
18040 tf_warning_or_error, NULL_TREE,
18041 /*integral_constant_expression_p=*/false);
18042 in_base_initializer = 0;
18047 init = build_tree_list (decl, init);
18048 TREE_CHAIN (init) = inits;
18056 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
18059 set_current_access_from_decl (tree decl)
18061 if (TREE_PRIVATE (decl))
18062 current_access_specifier = access_private_node;
18063 else if (TREE_PROTECTED (decl))
18064 current_access_specifier = access_protected_node;
18066 current_access_specifier = access_public_node;
18069 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
18070 is the instantiation (which should have been created with
18071 start_enum) and ARGS are the template arguments to use. */
18074 tsubst_enum (tree tag, tree newtag, tree args)
18078 if (SCOPED_ENUM_P (newtag))
18079 begin_scope (sk_scoped_enum, newtag);
18081 for (e = TYPE_VALUES (tag); e; e = TREE_CHAIN (e))
18086 decl = TREE_VALUE (e);
18087 /* Note that in a template enum, the TREE_VALUE is the
18088 CONST_DECL, not the corresponding INTEGER_CST. */
18089 value = tsubst_expr (DECL_INITIAL (decl),
18090 args, tf_warning_or_error, NULL_TREE,
18091 /*integral_constant_expression_p=*/true);
18093 /* Give this enumeration constant the correct access. */
18094 set_current_access_from_decl (decl);
18096 /* Actually build the enumerator itself. */
18098 (DECL_NAME (decl), value, newtag, DECL_SOURCE_LOCATION (decl));
18101 if (SCOPED_ENUM_P (newtag))
18104 finish_enum_value_list (newtag);
18105 finish_enum (newtag);
18107 DECL_SOURCE_LOCATION (TYPE_NAME (newtag))
18108 = DECL_SOURCE_LOCATION (TYPE_NAME (tag));
18111 /* DECL is a FUNCTION_DECL that is a template specialization. Return
18112 its type -- but without substituting the innermost set of template
18113 arguments. So, innermost set of template parameters will appear in
18117 get_mostly_instantiated_function_type (tree decl)
18125 tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
18126 targs = DECL_TI_ARGS (decl);
18127 tparms = DECL_TEMPLATE_PARMS (tmpl);
18128 parm_depth = TMPL_PARMS_DEPTH (tparms);
18130 /* There should be as many levels of arguments as there are levels
18132 gcc_assert (parm_depth == TMPL_ARGS_DEPTH (targs));
18134 fn_type = TREE_TYPE (tmpl);
18136 if (parm_depth == 1)
18137 /* No substitution is necessary. */
18144 /* Replace the innermost level of the TARGS with NULL_TREEs to
18145 let tsubst know not to substitute for those parameters. */
18146 partial_args = make_tree_vec (TREE_VEC_LENGTH (targs));
18147 for (i = 1; i < TMPL_ARGS_DEPTH (targs); ++i)
18148 SET_TMPL_ARGS_LEVEL (partial_args, i,
18149 TMPL_ARGS_LEVEL (targs, i));
18150 SET_TMPL_ARGS_LEVEL (partial_args,
18151 TMPL_ARGS_DEPTH (targs),
18152 make_tree_vec (DECL_NTPARMS (tmpl)));
18154 /* Make sure that we can see identifiers, and compute access
18156 push_access_scope (decl);
18158 ++processing_template_decl;
18159 /* Now, do the (partial) substitution to figure out the
18160 appropriate function type. */
18161 fn_type = tsubst (fn_type, partial_args, tf_error, NULL_TREE);
18162 --processing_template_decl;
18164 /* Substitute into the template parameters to obtain the real
18165 innermost set of parameters. This step is important if the
18166 innermost set of template parameters contains value
18167 parameters whose types depend on outer template parameters. */
18168 TREE_VEC_LENGTH (partial_args)--;
18169 tparms = tsubst_template_parms (tparms, partial_args, tf_error);
18171 pop_access_scope (decl);
18177 /* Return truthvalue if we're processing a template different from
18178 the last one involved in diagnostics. */
18180 problematic_instantiation_changed (void)
18182 return last_template_error_tick != tinst_level_tick;
18185 /* Remember current template involved in diagnostics. */
18187 record_last_problematic_instantiation (void)
18189 last_template_error_tick = tinst_level_tick;
18192 struct tinst_level *
18193 current_instantiation (void)
18195 return current_tinst_level;
18198 /* [temp.param] Check that template non-type parm TYPE is of an allowable
18199 type. Return zero for ok, nonzero for disallowed. Issue error and
18200 warning messages under control of COMPLAIN. */
18203 invalid_nontype_parm_type_p (tree type, tsubst_flags_t complain)
18205 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
18207 else if (POINTER_TYPE_P (type))
18209 else if (TYPE_PTR_TO_MEMBER_P (type))
18211 else if (TREE_CODE (type) == TEMPLATE_TYPE_PARM)
18213 else if (TREE_CODE (type) == TYPENAME_TYPE)
18215 else if (TREE_CODE (type) == DECLTYPE_TYPE)
18218 if (complain & tf_error)
18219 error ("%q#T is not a valid type for a template constant parameter", type);
18223 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
18224 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
18227 dependent_type_p_r (tree type)
18233 A type is dependent if it is:
18235 -- a template parameter. Template template parameters are types
18236 for us (since TYPE_P holds true for them) so we handle
18238 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
18239 || TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM)
18241 /* -- a qualified-id with a nested-name-specifier which contains a
18242 class-name that names a dependent type or whose unqualified-id
18243 names a dependent type. */
18244 if (TREE_CODE (type) == TYPENAME_TYPE)
18246 /* -- a cv-qualified type where the cv-unqualified type is
18248 type = TYPE_MAIN_VARIANT (type);
18249 /* -- a compound type constructed from any dependent type. */
18250 if (TYPE_PTR_TO_MEMBER_P (type))
18251 return (dependent_type_p (TYPE_PTRMEM_CLASS_TYPE (type))
18252 || dependent_type_p (TYPE_PTRMEM_POINTED_TO_TYPE
18254 else if (TREE_CODE (type) == POINTER_TYPE
18255 || TREE_CODE (type) == REFERENCE_TYPE)
18256 return dependent_type_p (TREE_TYPE (type));
18257 else if (TREE_CODE (type) == FUNCTION_TYPE
18258 || TREE_CODE (type) == METHOD_TYPE)
18262 if (dependent_type_p (TREE_TYPE (type)))
18264 for (arg_type = TYPE_ARG_TYPES (type);
18266 arg_type = TREE_CHAIN (arg_type))
18267 if (dependent_type_p (TREE_VALUE (arg_type)))
18271 /* -- an array type constructed from any dependent type or whose
18272 size is specified by a constant expression that is
18275 We checked for type- and value-dependence of the bounds in
18276 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
18277 if (TREE_CODE (type) == ARRAY_TYPE)
18279 if (TYPE_DOMAIN (type)
18280 && dependent_type_p (TYPE_DOMAIN (type)))
18282 return dependent_type_p (TREE_TYPE (type));
18285 /* -- a template-id in which either the template name is a template
18287 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
18289 /* ... or any of the template arguments is a dependent type or
18290 an expression that is type-dependent or value-dependent. */
18291 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INFO (type)
18292 && (any_dependent_template_arguments_p
18293 (INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type)))))
18296 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
18297 dependent; if the argument of the `typeof' expression is not
18298 type-dependent, then it should already been have resolved. */
18299 if (TREE_CODE (type) == TYPEOF_TYPE
18300 || TREE_CODE (type) == DECLTYPE_TYPE
18301 || TREE_CODE (type) == UNDERLYING_TYPE)
18304 /* A template argument pack is dependent if any of its packed
18306 if (TREE_CODE (type) == TYPE_ARGUMENT_PACK)
18308 tree args = ARGUMENT_PACK_ARGS (type);
18309 int i, len = TREE_VEC_LENGTH (args);
18310 for (i = 0; i < len; ++i)
18311 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
18315 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
18316 be template parameters. */
18317 if (TREE_CODE (type) == TYPE_PACK_EXPANSION)
18320 /* The standard does not specifically mention types that are local
18321 to template functions or local classes, but they should be
18322 considered dependent too. For example:
18324 template <int I> void f() {
18329 The size of `E' cannot be known until the value of `I' has been
18330 determined. Therefore, `E' must be considered dependent. */
18331 scope = TYPE_CONTEXT (type);
18332 if (scope && TYPE_P (scope))
18333 return dependent_type_p (scope);
18334 /* Don't use type_dependent_expression_p here, as it can lead
18335 to infinite recursion trying to determine whether a lambda
18336 nested in a lambda is dependent (c++/47687). */
18337 else if (scope && TREE_CODE (scope) == FUNCTION_DECL
18338 && DECL_LANG_SPECIFIC (scope)
18339 && DECL_TEMPLATE_INFO (scope)
18340 && (any_dependent_template_arguments_p
18341 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (scope)))))
18344 /* Other types are non-dependent. */
18348 /* Returns TRUE if TYPE is dependent, in the sense of
18349 [temp.dep.type]. Note that a NULL type is considered dependent. */
18352 dependent_type_p (tree type)
18354 /* If there are no template parameters in scope, then there can't be
18355 any dependent types. */
18356 if (!processing_template_decl)
18358 /* If we are not processing a template, then nobody should be
18359 providing us with a dependent type. */
18361 gcc_assert (TREE_CODE (type) != TEMPLATE_TYPE_PARM || is_auto (type));
18365 /* If the type is NULL, we have not computed a type for the entity
18366 in question; in that case, the type is dependent. */
18370 /* Erroneous types can be considered non-dependent. */
18371 if (type == error_mark_node)
18374 /* If we have not already computed the appropriate value for TYPE,
18376 if (!TYPE_DEPENDENT_P_VALID (type))
18378 TYPE_DEPENDENT_P (type) = dependent_type_p_r (type);
18379 TYPE_DEPENDENT_P_VALID (type) = 1;
18382 return TYPE_DEPENDENT_P (type);
18385 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
18386 lookup. In other words, a dependent type that is not the current
18390 dependent_scope_p (tree scope)
18392 return (scope && TYPE_P (scope) && dependent_type_p (scope)
18393 && !currently_open_class (scope));
18396 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
18397 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
18400 /* Note that this predicate is not appropriate for general expressions;
18401 only constant expressions (that satisfy potential_constant_expression)
18402 can be tested for value dependence.
18404 We should really also have a predicate for "instantiation-dependent".
18406 fold_non_dependent_expr: fold if constant and not type-dependent and not value-dependent.
18407 (what about instantiation-dependent constant-expressions?)
18408 is_late_template_attribute: defer if instantiation-dependent.
18409 compute_array_index_type: proceed if constant and not t- or v-dependent
18410 if instantiation-dependent, need to remember full expression
18411 uses_template_parms: FIXME - need to audit callers
18412 tsubst_decl [function_decl]: Why is this using value_dependent_expression_p?
18413 dependent_type_p [array_type]: dependent if index type is dependent
18415 static_assert - instantiation-dependent */
18418 value_dependent_expression_p (tree expression)
18420 if (!processing_template_decl)
18423 /* A name declared with a dependent type. */
18424 if (DECL_P (expression) && type_dependent_expression_p (expression))
18427 switch (TREE_CODE (expression))
18429 case IDENTIFIER_NODE:
18430 /* A name that has not been looked up -- must be dependent. */
18433 case TEMPLATE_PARM_INDEX:
18434 /* A non-type template parm. */
18438 /* A non-type template parm. */
18439 if (DECL_TEMPLATE_PARM_P (expression))
18441 return value_dependent_expression_p (DECL_INITIAL (expression));
18444 /* A constant with literal type and is initialized
18445 with an expression that is value-dependent. */
18446 if (DECL_INITIAL (expression)
18447 && decl_constant_var_p (expression)
18448 && value_dependent_expression_p (DECL_INITIAL (expression)))
18452 case DYNAMIC_CAST_EXPR:
18453 case STATIC_CAST_EXPR:
18454 case CONST_CAST_EXPR:
18455 case REINTERPRET_CAST_EXPR:
18457 /* These expressions are value-dependent if the type to which
18458 the cast occurs is dependent or the expression being casted
18459 is value-dependent. */
18461 tree type = TREE_TYPE (expression);
18463 if (dependent_type_p (type))
18466 /* A functional cast has a list of operands. */
18467 expression = TREE_OPERAND (expression, 0);
18470 /* If there are no operands, it must be an expression such
18471 as "int()". This should not happen for aggregate types
18472 because it would form non-constant expressions. */
18473 gcc_assert (cxx_dialect >= cxx0x
18474 || INTEGRAL_OR_ENUMERATION_TYPE_P (type));
18479 if (TREE_CODE (expression) == TREE_LIST)
18480 return any_value_dependent_elements_p (expression);
18482 return value_dependent_expression_p (expression);
18488 /* A `sizeof' expression is value-dependent if the operand is
18489 type-dependent or is a pack expansion. */
18490 expression = TREE_OPERAND (expression, 0);
18491 if (PACK_EXPANSION_P (expression))
18493 else if (TYPE_P (expression))
18494 return dependent_type_p (expression);
18495 return type_dependent_expression_p (expression);
18497 case AT_ENCODE_EXPR:
18498 /* An 'encode' expression is value-dependent if the operand is
18500 expression = TREE_OPERAND (expression, 0);
18501 return dependent_type_p (expression);
18503 case NOEXCEPT_EXPR:
18504 expression = TREE_OPERAND (expression, 0);
18505 return type_dependent_expression_p (expression);
18509 tree name = TREE_OPERAND (expression, 1);
18510 return value_dependent_expression_p (name);
18513 case COMPONENT_REF:
18514 return (value_dependent_expression_p (TREE_OPERAND (expression, 0))
18515 || value_dependent_expression_p (TREE_OPERAND (expression, 1)));
18517 case NONTYPE_ARGUMENT_PACK:
18518 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
18519 is value-dependent. */
18521 tree values = ARGUMENT_PACK_ARGS (expression);
18522 int i, len = TREE_VEC_LENGTH (values);
18524 for (i = 0; i < len; ++i)
18525 if (value_dependent_expression_p (TREE_VEC_ELT (values, i)))
18533 tree type2 = TRAIT_EXPR_TYPE2 (expression);
18534 return (dependent_type_p (TRAIT_EXPR_TYPE1 (expression))
18535 || (type2 ? dependent_type_p (type2) : false));
18539 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
18540 || (value_dependent_expression_p (TREE_OPERAND (expression, 2))));
18543 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
18544 || (value_dependent_expression_p (TREE_OPERAND (expression, 1))));
18548 tree op = TREE_OPERAND (expression, 0);
18549 return (value_dependent_expression_p (op)
18550 || has_value_dependent_address (op));
18555 tree fn = get_callee_fndecl (expression);
18557 if (!fn && value_dependent_expression_p (CALL_EXPR_FN (expression)))
18559 nargs = call_expr_nargs (expression);
18560 for (i = 0; i < nargs; ++i)
18562 tree op = CALL_EXPR_ARG (expression, i);
18563 /* In a call to a constexpr member function, look through the
18564 implicit ADDR_EXPR on the object argument so that it doesn't
18565 cause the call to be considered value-dependent. We also
18566 look through it in potential_constant_expression. */
18567 if (i == 0 && fn && DECL_DECLARED_CONSTEXPR_P (fn)
18568 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
18569 && TREE_CODE (op) == ADDR_EXPR)
18570 op = TREE_OPERAND (op, 0);
18571 if (value_dependent_expression_p (op))
18577 case TEMPLATE_ID_EXPR:
18578 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
18580 return type_dependent_expression_p (expression);
18586 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), ix, val)
18587 if (value_dependent_expression_p (val))
18593 /* A constant expression is value-dependent if any subexpression is
18594 value-dependent. */
18595 switch (TREE_CODE_CLASS (TREE_CODE (expression)))
18597 case tcc_reference:
18599 case tcc_comparison:
18601 case tcc_expression:
18604 int i, len = cp_tree_operand_length (expression);
18606 for (i = 0; i < len; i++)
18608 tree t = TREE_OPERAND (expression, i);
18610 /* In some cases, some of the operands may be missing.l
18611 (For example, in the case of PREDECREMENT_EXPR, the
18612 amount to increment by may be missing.) That doesn't
18613 make the expression dependent. */
18614 if (t && value_dependent_expression_p (t))
18625 /* The expression is not value-dependent. */
18629 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
18630 [temp.dep.expr]. Note that an expression with no type is
18631 considered dependent. Other parts of the compiler arrange for an
18632 expression with type-dependent subexpressions to have no type, so
18633 this function doesn't have to be fully recursive. */
18636 type_dependent_expression_p (tree expression)
18638 if (!processing_template_decl)
18641 if (expression == error_mark_node)
18644 /* An unresolved name is always dependent. */
18645 if (TREE_CODE (expression) == IDENTIFIER_NODE
18646 || TREE_CODE (expression) == USING_DECL)
18649 /* Some expression forms are never type-dependent. */
18650 if (TREE_CODE (expression) == PSEUDO_DTOR_EXPR
18651 || TREE_CODE (expression) == SIZEOF_EXPR
18652 || TREE_CODE (expression) == ALIGNOF_EXPR
18653 || TREE_CODE (expression) == AT_ENCODE_EXPR
18654 || TREE_CODE (expression) == NOEXCEPT_EXPR
18655 || TREE_CODE (expression) == TRAIT_EXPR
18656 || TREE_CODE (expression) == TYPEID_EXPR
18657 || TREE_CODE (expression) == DELETE_EXPR
18658 || TREE_CODE (expression) == VEC_DELETE_EXPR
18659 || TREE_CODE (expression) == THROW_EXPR)
18662 /* The types of these expressions depends only on the type to which
18663 the cast occurs. */
18664 if (TREE_CODE (expression) == DYNAMIC_CAST_EXPR
18665 || TREE_CODE (expression) == STATIC_CAST_EXPR
18666 || TREE_CODE (expression) == CONST_CAST_EXPR
18667 || TREE_CODE (expression) == REINTERPRET_CAST_EXPR
18668 || TREE_CODE (expression) == CAST_EXPR)
18669 return dependent_type_p (TREE_TYPE (expression));
18671 /* The types of these expressions depends only on the type created
18672 by the expression. */
18673 if (TREE_CODE (expression) == NEW_EXPR
18674 || TREE_CODE (expression) == VEC_NEW_EXPR)
18676 /* For NEW_EXPR tree nodes created inside a template, either
18677 the object type itself or a TREE_LIST may appear as the
18679 tree type = TREE_OPERAND (expression, 1);
18680 if (TREE_CODE (type) == TREE_LIST)
18681 /* This is an array type. We need to check array dimensions
18683 return dependent_type_p (TREE_VALUE (TREE_PURPOSE (type)))
18684 || value_dependent_expression_p
18685 (TREE_OPERAND (TREE_VALUE (type), 1));
18687 return dependent_type_p (type);
18690 if (TREE_CODE (expression) == SCOPE_REF)
18692 tree scope = TREE_OPERAND (expression, 0);
18693 tree name = TREE_OPERAND (expression, 1);
18695 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
18696 contains an identifier associated by name lookup with one or more
18697 declarations declared with a dependent type, or...a
18698 nested-name-specifier or qualified-id that names a member of an
18699 unknown specialization. */
18700 return (type_dependent_expression_p (name)
18701 || dependent_scope_p (scope));
18704 if (TREE_CODE (expression) == FUNCTION_DECL
18705 && DECL_LANG_SPECIFIC (expression)
18706 && DECL_TEMPLATE_INFO (expression)
18707 && (any_dependent_template_arguments_p
18708 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (expression)))))
18711 if (TREE_CODE (expression) == TEMPLATE_DECL
18712 && !DECL_TEMPLATE_TEMPLATE_PARM_P (expression))
18715 if (TREE_CODE (expression) == STMT_EXPR)
18716 expression = stmt_expr_value_expr (expression);
18718 if (BRACE_ENCLOSED_INITIALIZER_P (expression))
18723 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), i, elt)
18725 if (type_dependent_expression_p (elt))
18731 /* A static data member of the current instantiation with incomplete
18732 array type is type-dependent, as the definition and specializations
18733 can have different bounds. */
18734 if (TREE_CODE (expression) == VAR_DECL
18735 && DECL_CLASS_SCOPE_P (expression)
18736 && dependent_type_p (DECL_CONTEXT (expression))
18737 && VAR_HAD_UNKNOWN_BOUND (expression))
18740 if (TREE_TYPE (expression) == unknown_type_node)
18742 if (TREE_CODE (expression) == ADDR_EXPR)
18743 return type_dependent_expression_p (TREE_OPERAND (expression, 0));
18744 if (TREE_CODE (expression) == COMPONENT_REF
18745 || TREE_CODE (expression) == OFFSET_REF)
18747 if (type_dependent_expression_p (TREE_OPERAND (expression, 0)))
18749 expression = TREE_OPERAND (expression, 1);
18750 if (TREE_CODE (expression) == IDENTIFIER_NODE)
18753 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
18754 if (TREE_CODE (expression) == SCOPE_REF)
18757 if (TREE_CODE (expression) == BASELINK)
18758 expression = BASELINK_FUNCTIONS (expression);
18760 if (TREE_CODE (expression) == TEMPLATE_ID_EXPR)
18762 if (any_dependent_template_arguments_p
18763 (TREE_OPERAND (expression, 1)))
18765 expression = TREE_OPERAND (expression, 0);
18767 gcc_assert (TREE_CODE (expression) == OVERLOAD
18768 || TREE_CODE (expression) == FUNCTION_DECL);
18772 if (type_dependent_expression_p (OVL_CURRENT (expression)))
18774 expression = OVL_NEXT (expression);
18779 gcc_assert (TREE_CODE (expression) != TYPE_DECL);
18781 return (dependent_type_p (TREE_TYPE (expression)));
18784 /* Like type_dependent_expression_p, but it also works while not processing
18785 a template definition, i.e. during substitution or mangling. */
18788 type_dependent_expression_p_push (tree expr)
18791 ++processing_template_decl;
18792 b = type_dependent_expression_p (expr);
18793 --processing_template_decl;
18797 /* Returns TRUE if ARGS contains a type-dependent expression. */
18800 any_type_dependent_arguments_p (const VEC(tree,gc) *args)
18805 FOR_EACH_VEC_ELT (tree, args, i, arg)
18807 if (type_dependent_expression_p (arg))
18813 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
18814 expressions) contains any type-dependent expressions. */
18817 any_type_dependent_elements_p (const_tree list)
18819 for (; list; list = TREE_CHAIN (list))
18820 if (value_dependent_expression_p (TREE_VALUE (list)))
18826 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
18827 expressions) contains any value-dependent expressions. */
18830 any_value_dependent_elements_p (const_tree list)
18832 for (; list; list = TREE_CHAIN (list))
18833 if (value_dependent_expression_p (TREE_VALUE (list)))
18839 /* Returns TRUE if the ARG (a template argument) is dependent. */
18842 dependent_template_arg_p (tree arg)
18844 if (!processing_template_decl)
18847 /* Assume a template argument that was wrongly written by the user
18848 is dependent. This is consistent with what
18849 any_dependent_template_arguments_p [that calls this function]
18851 if (!arg || arg == error_mark_node)
18854 if (TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
18855 arg = ARGUMENT_PACK_SELECT_ARG (arg);
18857 if (TREE_CODE (arg) == TEMPLATE_DECL
18858 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
18859 return dependent_template_p (arg);
18860 else if (ARGUMENT_PACK_P (arg))
18862 tree args = ARGUMENT_PACK_ARGS (arg);
18863 int i, len = TREE_VEC_LENGTH (args);
18864 for (i = 0; i < len; ++i)
18866 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
18872 else if (TYPE_P (arg))
18873 return dependent_type_p (arg);
18875 return (type_dependent_expression_p (arg)
18876 || value_dependent_expression_p (arg));
18879 /* Returns true if ARGS (a collection of template arguments) contains
18880 any types that require structural equality testing. */
18883 any_template_arguments_need_structural_equality_p (tree args)
18890 if (args == error_mark_node)
18893 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
18895 tree level = TMPL_ARGS_LEVEL (args, i + 1);
18896 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
18898 tree arg = TREE_VEC_ELT (level, j);
18899 tree packed_args = NULL_TREE;
18902 if (ARGUMENT_PACK_P (arg))
18904 /* Look inside the argument pack. */
18905 packed_args = ARGUMENT_PACK_ARGS (arg);
18906 len = TREE_VEC_LENGTH (packed_args);
18909 for (k = 0; k < len; ++k)
18912 arg = TREE_VEC_ELT (packed_args, k);
18914 if (error_operand_p (arg))
18916 else if (TREE_CODE (arg) == TEMPLATE_DECL
18917 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
18919 else if (TYPE_P (arg) && TYPE_STRUCTURAL_EQUALITY_P (arg))
18921 else if (!TYPE_P (arg) && TREE_TYPE (arg)
18922 && TYPE_STRUCTURAL_EQUALITY_P (TREE_TYPE (arg)))
18931 /* Returns true if ARGS (a collection of template arguments) contains
18932 any dependent arguments. */
18935 any_dependent_template_arguments_p (const_tree args)
18942 if (args == error_mark_node)
18945 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
18947 const_tree level = TMPL_ARGS_LEVEL (args, i + 1);
18948 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
18949 if (dependent_template_arg_p (TREE_VEC_ELT (level, j)))
18956 /* Returns TRUE if the template TMPL is dependent. */
18959 dependent_template_p (tree tmpl)
18961 if (TREE_CODE (tmpl) == OVERLOAD)
18965 if (dependent_template_p (OVL_CURRENT (tmpl)))
18967 tmpl = OVL_NEXT (tmpl);
18972 /* Template template parameters are dependent. */
18973 if (DECL_TEMPLATE_TEMPLATE_PARM_P (tmpl)
18974 || TREE_CODE (tmpl) == TEMPLATE_TEMPLATE_PARM)
18976 /* So are names that have not been looked up. */
18977 if (TREE_CODE (tmpl) == SCOPE_REF
18978 || TREE_CODE (tmpl) == IDENTIFIER_NODE)
18980 /* So are member templates of dependent classes. */
18981 if (TYPE_P (CP_DECL_CONTEXT (tmpl)))
18982 return dependent_type_p (DECL_CONTEXT (tmpl));
18986 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
18989 dependent_template_id_p (tree tmpl, tree args)
18991 return (dependent_template_p (tmpl)
18992 || any_dependent_template_arguments_p (args));
18995 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
18999 dependent_omp_for_p (tree declv, tree initv, tree condv, tree incrv)
19003 if (!processing_template_decl)
19006 for (i = 0; i < TREE_VEC_LENGTH (declv); i++)
19008 tree decl = TREE_VEC_ELT (declv, i);
19009 tree init = TREE_VEC_ELT (initv, i);
19010 tree cond = TREE_VEC_ELT (condv, i);
19011 tree incr = TREE_VEC_ELT (incrv, i);
19013 if (type_dependent_expression_p (decl))
19016 if (init && type_dependent_expression_p (init))
19019 if (type_dependent_expression_p (cond))
19022 if (COMPARISON_CLASS_P (cond)
19023 && (type_dependent_expression_p (TREE_OPERAND (cond, 0))
19024 || type_dependent_expression_p (TREE_OPERAND (cond, 1))))
19027 if (TREE_CODE (incr) == MODOP_EXPR)
19029 if (type_dependent_expression_p (TREE_OPERAND (incr, 0))
19030 || type_dependent_expression_p (TREE_OPERAND (incr, 2)))
19033 else if (type_dependent_expression_p (incr))
19035 else if (TREE_CODE (incr) == MODIFY_EXPR)
19037 if (type_dependent_expression_p (TREE_OPERAND (incr, 0)))
19039 else if (BINARY_CLASS_P (TREE_OPERAND (incr, 1)))
19041 tree t = TREE_OPERAND (incr, 1);
19042 if (type_dependent_expression_p (TREE_OPERAND (t, 0))
19043 || type_dependent_expression_p (TREE_OPERAND (t, 1)))
19052 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
19053 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
19054 no such TYPE can be found. Note that this function peers inside
19055 uninstantiated templates and therefore should be used only in
19056 extremely limited situations. ONLY_CURRENT_P restricts this
19057 peering to the currently open classes hierarchy (which is required
19058 when comparing types). */
19061 resolve_typename_type (tree type, bool only_current_p)
19070 gcc_assert (TREE_CODE (type) == TYPENAME_TYPE);
19072 scope = TYPE_CONTEXT (type);
19073 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
19074 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
19075 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
19076 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
19077 identifier of the TYPENAME_TYPE anymore.
19078 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
19079 TYPENAME_TYPE instead, we avoid messing up with a possible
19080 typedef variant case. */
19081 name = TYPE_IDENTIFIER (TYPE_MAIN_VARIANT (type));
19083 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
19084 it first before we can figure out what NAME refers to. */
19085 if (TREE_CODE (scope) == TYPENAME_TYPE)
19086 scope = resolve_typename_type (scope, only_current_p);
19087 /* If we don't know what SCOPE refers to, then we cannot resolve the
19089 if (TREE_CODE (scope) == TYPENAME_TYPE)
19091 /* If the SCOPE is a template type parameter, we have no way of
19092 resolving the name. */
19093 if (TREE_CODE (scope) == TEMPLATE_TYPE_PARM)
19095 /* If the SCOPE is not the current instantiation, there's no reason
19096 to look inside it. */
19097 if (only_current_p && !currently_open_class (scope))
19099 /* If this is a typedef, we don't want to look inside (c++/11987). */
19100 if (typedef_variant_p (type))
19102 /* If SCOPE isn't the template itself, it will not have a valid
19103 TYPE_FIELDS list. */
19104 if (same_type_p (scope, CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope)))
19105 /* scope is either the template itself or a compatible instantiation
19106 like X<T>, so look up the name in the original template. */
19107 scope = CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope);
19109 /* scope is a partial instantiation, so we can't do the lookup or we
19110 will lose the template arguments. */
19112 /* Enter the SCOPE so that name lookup will be resolved as if we
19113 were in the class definition. In particular, SCOPE will no
19114 longer be considered a dependent type. */
19115 pushed_scope = push_scope (scope);
19116 /* Look up the declaration. */
19117 decl = lookup_member (scope, name, /*protect=*/0, /*want_type=*/true);
19119 result = NULL_TREE;
19121 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
19122 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
19125 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == IDENTIFIER_NODE
19126 && TREE_CODE (decl) == TYPE_DECL)
19128 result = TREE_TYPE (decl);
19129 if (result == error_mark_node)
19130 result = NULL_TREE;
19132 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == TEMPLATE_ID_EXPR
19133 && DECL_CLASS_TEMPLATE_P (decl))
19137 /* Obtain the template and the arguments. */
19138 tmpl = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 0);
19139 args = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 1);
19140 /* Instantiate the template. */
19141 result = lookup_template_class (tmpl, args, NULL_TREE, NULL_TREE,
19142 /*entering_scope=*/0,
19143 tf_error | tf_user);
19144 if (result == error_mark_node)
19145 result = NULL_TREE;
19148 /* Leave the SCOPE. */
19150 pop_scope (pushed_scope);
19152 /* If we failed to resolve it, return the original typename. */
19156 /* If lookup found a typename type, resolve that too. */
19157 if (TREE_CODE (result) == TYPENAME_TYPE && !TYPENAME_IS_RESOLVING_P (result))
19159 /* Ill-formed programs can cause infinite recursion here, so we
19160 must catch that. */
19161 TYPENAME_IS_RESOLVING_P (type) = 1;
19162 result = resolve_typename_type (result, only_current_p);
19163 TYPENAME_IS_RESOLVING_P (type) = 0;
19166 /* Qualify the resulting type. */
19167 quals = cp_type_quals (type);
19169 result = cp_build_qualified_type (result, cp_type_quals (result) | quals);
19174 /* EXPR is an expression which is not type-dependent. Return a proxy
19175 for EXPR that can be used to compute the types of larger
19176 expressions containing EXPR. */
19179 build_non_dependent_expr (tree expr)
19183 #ifdef ENABLE_CHECKING
19184 /* Try to get a constant value for all non-type-dependent expressions in
19185 order to expose bugs in *_dependent_expression_p and constexpr. */
19186 if (cxx_dialect >= cxx0x)
19187 maybe_constant_value (fold_non_dependent_expr_sfinae (expr, tf_none));
19190 /* Preserve OVERLOADs; the functions must be available to resolve
19193 if (TREE_CODE (inner_expr) == STMT_EXPR)
19194 inner_expr = stmt_expr_value_expr (inner_expr);
19195 if (TREE_CODE (inner_expr) == ADDR_EXPR)
19196 inner_expr = TREE_OPERAND (inner_expr, 0);
19197 if (TREE_CODE (inner_expr) == COMPONENT_REF)
19198 inner_expr = TREE_OPERAND (inner_expr, 1);
19199 if (is_overloaded_fn (inner_expr)
19200 || TREE_CODE (inner_expr) == OFFSET_REF)
19202 /* There is no need to return a proxy for a variable. */
19203 if (TREE_CODE (expr) == VAR_DECL)
19205 /* Preserve string constants; conversions from string constants to
19206 "char *" are allowed, even though normally a "const char *"
19207 cannot be used to initialize a "char *". */
19208 if (TREE_CODE (expr) == STRING_CST)
19210 /* Preserve arithmetic constants, as an optimization -- there is no
19211 reason to create a new node. */
19212 if (TREE_CODE (expr) == INTEGER_CST || TREE_CODE (expr) == REAL_CST)
19214 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
19215 There is at least one place where we want to know that a
19216 particular expression is a throw-expression: when checking a ?:
19217 expression, there are special rules if the second or third
19218 argument is a throw-expression. */
19219 if (TREE_CODE (expr) == THROW_EXPR)
19222 if (TREE_CODE (expr) == COND_EXPR)
19223 return build3 (COND_EXPR,
19225 TREE_OPERAND (expr, 0),
19226 (TREE_OPERAND (expr, 1)
19227 ? build_non_dependent_expr (TREE_OPERAND (expr, 1))
19228 : build_non_dependent_expr (TREE_OPERAND (expr, 0))),
19229 build_non_dependent_expr (TREE_OPERAND (expr, 2)));
19230 if (TREE_CODE (expr) == COMPOUND_EXPR
19231 && !COMPOUND_EXPR_OVERLOADED (expr))
19232 return build2 (COMPOUND_EXPR,
19234 TREE_OPERAND (expr, 0),
19235 build_non_dependent_expr (TREE_OPERAND (expr, 1)));
19237 /* If the type is unknown, it can't really be non-dependent */
19238 gcc_assert (TREE_TYPE (expr) != unknown_type_node);
19240 /* Otherwise, build a NON_DEPENDENT_EXPR. */
19241 return build1 (NON_DEPENDENT_EXPR, TREE_TYPE (expr), expr);
19244 /* ARGS is a vector of expressions as arguments to a function call.
19245 Replace the arguments with equivalent non-dependent expressions.
19246 This modifies ARGS in place. */
19249 make_args_non_dependent (VEC(tree,gc) *args)
19254 FOR_EACH_VEC_ELT (tree, args, ix, arg)
19256 tree newarg = build_non_dependent_expr (arg);
19258 VEC_replace (tree, args, ix, newarg);
19262 /* Returns a type which represents 'auto'. We use a TEMPLATE_TYPE_PARM
19263 with a level one deeper than the actual template parms. */
19268 tree au = cxx_make_type (TEMPLATE_TYPE_PARM);
19269 TYPE_NAME (au) = build_decl (BUILTINS_LOCATION,
19270 TYPE_DECL, get_identifier ("auto"), au);
19271 TYPE_STUB_DECL (au) = TYPE_NAME (au);
19272 TEMPLATE_TYPE_PARM_INDEX (au) = build_template_parm_index
19273 (0, processing_template_decl + 1, processing_template_decl + 1,
19274 0, TYPE_NAME (au), NULL_TREE);
19275 TYPE_CANONICAL (au) = canonical_type_parameter (au);
19276 DECL_ARTIFICIAL (TYPE_NAME (au)) = 1;
19277 SET_DECL_TEMPLATE_PARM_P (TYPE_NAME (au));
19282 /* Given type ARG, return std::initializer_list<ARG>. */
19287 tree std_init_list = namespace_binding
19288 (get_identifier ("initializer_list"), std_node);
19290 if (!std_init_list || !DECL_CLASS_TEMPLATE_P (std_init_list))
19292 error ("deducing from brace-enclosed initializer list requires "
19293 "#include <initializer_list>");
19294 return error_mark_node;
19296 argvec = make_tree_vec (1);
19297 TREE_VEC_ELT (argvec, 0) = arg;
19298 return lookup_template_class (std_init_list, argvec, NULL_TREE,
19299 NULL_TREE, 0, tf_warning_or_error);
19302 /* Replace auto in TYPE with std::initializer_list<auto>. */
19305 listify_autos (tree type, tree auto_node)
19307 tree init_auto = listify (auto_node);
19308 tree argvec = make_tree_vec (1);
19309 TREE_VEC_ELT (argvec, 0) = init_auto;
19310 if (processing_template_decl)
19311 argvec = add_to_template_args (current_template_args (), argvec);
19312 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
19315 /* walk_tree helper for do_auto_deduction. */
19318 contains_auto_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
19321 /* Is this a variable with the type we're looking for? */
19323 && TREE_TYPE (*tp) == type)
19329 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
19330 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
19333 do_auto_deduction (tree type, tree init, tree auto_node)
19335 tree parms, tparms, targs;
19340 if (processing_template_decl
19341 && (TREE_TYPE (init) == NULL_TREE
19342 || BRACE_ENCLOSED_INITIALIZER_P (init)))
19343 /* Not enough information to try this yet. */
19346 /* The name of the object being declared shall not appear in the
19347 initializer expression. */
19348 decl = cp_walk_tree_without_duplicates (&init, contains_auto_r, type);
19351 error ("variable %q#D with %<auto%> type used in its own "
19352 "initializer", decl);
19353 return error_mark_node;
19356 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
19357 with either a new invented type template parameter U or, if the
19358 initializer is a braced-init-list (8.5.4), with
19359 std::initializer_list<U>. */
19360 if (BRACE_ENCLOSED_INITIALIZER_P (init))
19361 type = listify_autos (type, auto_node);
19363 init = resolve_nondeduced_context (init);
19365 parms = build_tree_list (NULL_TREE, type);
19367 tparms = make_tree_vec (1);
19368 targs = make_tree_vec (1);
19369 TREE_VEC_ELT (tparms, 0)
19370 = build_tree_list (NULL_TREE, TYPE_NAME (auto_node));
19371 val = type_unification_real (tparms, targs, parms, args, 1, 0,
19372 DEDUCE_CALL, LOOKUP_NORMAL);
19375 if (processing_template_decl)
19376 /* Try again at instantiation time. */
19378 if (type && type != error_mark_node)
19379 /* If type is error_mark_node a diagnostic must have been
19380 emitted by now. Also, having a mention to '<type error>'
19381 in the diagnostic is not really useful to the user. */
19382 error ("unable to deduce %qT from %qE", type, init);
19383 return error_mark_node;
19386 /* If the list of declarators contains more than one declarator, the type
19387 of each declared variable is determined as described above. If the
19388 type deduced for the template parameter U is not the same in each
19389 deduction, the program is ill-formed. */
19390 if (TREE_TYPE (auto_node)
19391 && !same_type_p (TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0)))
19393 error ("inconsistent deduction for %qT: %qT and then %qT",
19394 auto_node, TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0));
19395 return error_mark_node;
19397 TREE_TYPE (auto_node) = TREE_VEC_ELT (targs, 0);
19399 if (processing_template_decl)
19400 targs = add_to_template_args (current_template_args (), targs);
19401 return tsubst (type, targs, tf_warning_or_error, NULL_TREE);
19404 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
19408 splice_late_return_type (tree type, tree late_return_type)
19412 if (late_return_type == NULL_TREE)
19414 argvec = make_tree_vec (1);
19415 TREE_VEC_ELT (argvec, 0) = late_return_type;
19416 if (processing_template_parmlist)
19417 /* For a late-specified return type in a template type-parameter, we
19418 need to add a dummy argument level for its parmlist. */
19419 argvec = add_to_template_args
19420 (make_tree_vec (processing_template_parmlist), argvec);
19421 if (current_template_parms)
19422 argvec = add_to_template_args (current_template_args (), argvec);
19423 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
19426 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto'. */
19429 is_auto (const_tree type)
19431 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
19432 && TYPE_IDENTIFIER (type) == get_identifier ("auto"))
19438 /* Returns true iff TYPE contains a use of 'auto'. Since auto can only
19439 appear as a type-specifier for the declaration in question, we don't
19440 have to look through the whole type. */
19443 type_uses_auto (tree type)
19445 enum tree_code code;
19446 if (is_auto (type))
19449 code = TREE_CODE (type);
19451 if (code == POINTER_TYPE || code == REFERENCE_TYPE
19452 || code == OFFSET_TYPE || code == FUNCTION_TYPE
19453 || code == METHOD_TYPE || code == ARRAY_TYPE)
19454 return type_uses_auto (TREE_TYPE (type));
19456 if (TYPE_PTRMEMFUNC_P (type))
19457 return type_uses_auto (TREE_TYPE (TREE_TYPE
19458 (TYPE_PTRMEMFUNC_FN_TYPE (type))));
19463 /* For a given template T, return the vector of typedefs referenced
19464 in T for which access check is needed at T instantiation time.
19465 T is either a FUNCTION_DECL or a RECORD_TYPE.
19466 Those typedefs were added to T by the function
19467 append_type_to_template_for_access_check. */
19469 VEC(qualified_typedef_usage_t,gc)*
19470 get_types_needing_access_check (tree t)
19473 VEC(qualified_typedef_usage_t,gc) *result = NULL;
19475 if (!t || t == error_mark_node)
19478 if (!(ti = get_template_info (t)))
19481 if (CLASS_TYPE_P (t)
19482 || TREE_CODE (t) == FUNCTION_DECL)
19484 if (!TI_TEMPLATE (ti))
19487 result = TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti);
19493 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
19494 tied to T. That list of typedefs will be access checked at
19495 T instantiation time.
19496 T is either a FUNCTION_DECL or a RECORD_TYPE.
19497 TYPE_DECL is a TYPE_DECL node representing a typedef.
19498 SCOPE is the scope through which TYPE_DECL is accessed.
19499 LOCATION is the location of the usage point of TYPE_DECL.
19501 This function is a subroutine of
19502 append_type_to_template_for_access_check. */
19505 append_type_to_template_for_access_check_1 (tree t,
19508 location_t location)
19510 qualified_typedef_usage_t typedef_usage;
19513 if (!t || t == error_mark_node)
19516 gcc_assert ((TREE_CODE (t) == FUNCTION_DECL
19517 || CLASS_TYPE_P (t))
19519 && TREE_CODE (type_decl) == TYPE_DECL
19522 if (!(ti = get_template_info (t)))
19525 gcc_assert (TI_TEMPLATE (ti));
19527 typedef_usage.typedef_decl = type_decl;
19528 typedef_usage.context = scope;
19529 typedef_usage.locus = location;
19531 VEC_safe_push (qualified_typedef_usage_t, gc,
19532 TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti),
19536 /* Append TYPE_DECL to the template TEMPL.
19537 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
19538 At TEMPL instanciation time, TYPE_DECL will be checked to see
19539 if it can be accessed through SCOPE.
19540 LOCATION is the location of the usage point of TYPE_DECL.
19542 e.g. consider the following code snippet:
19549 template<class U> struct S
19551 C::myint mi; // <-- usage point of the typedef C::myint
19556 At S<char> instantiation time, we need to check the access of C::myint
19557 In other words, we need to check the access of the myint typedef through
19558 the C scope. For that purpose, this function will add the myint typedef
19559 and the scope C through which its being accessed to a list of typedefs
19560 tied to the template S. That list will be walked at template instantiation
19561 time and access check performed on each typedefs it contains.
19562 Note that this particular code snippet should yield an error because
19563 myint is private to C. */
19566 append_type_to_template_for_access_check (tree templ,
19569 location_t location)
19571 qualified_typedef_usage_t *iter;
19574 gcc_assert (type_decl && (TREE_CODE (type_decl) == TYPE_DECL));
19576 /* Make sure we don't append the type to the template twice. */
19577 FOR_EACH_VEC_ELT (qualified_typedef_usage_t,
19578 get_types_needing_access_check (templ),
19580 if (iter->typedef_decl == type_decl && scope == iter->context)
19583 append_type_to_template_for_access_check_1 (templ, type_decl,
19587 /* Set up the hash tables for template instantiations. */
19590 init_template_processing (void)
19592 decl_specializations = htab_create_ggc (37,
19593 hash_specialization,
19594 eq_specializations,
19596 type_specializations = htab_create_ggc (37,
19597 hash_specialization,
19598 eq_specializations,
19602 /* Print stats about the template hash tables for -fstats. */
19605 print_template_statistics (void)
19607 fprintf (stderr, "decl_specializations: size %ld, %ld elements, "
19608 "%f collisions\n", (long) htab_size (decl_specializations),
19609 (long) htab_elements (decl_specializations),
19610 htab_collisions (decl_specializations));
19611 fprintf (stderr, "type_specializations: size %ld, %ld elements, "
19612 "%f collisions\n", (long) htab_size (type_specializations),
19613 (long) htab_elements (type_specializations),
19614 htab_collisions (type_specializations));
19617 #include "gt-cp-pt.h"