1 /* Handle parameterized types (templates) for GNU C++.
2 Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
3 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010, 2011
4 Free Software Foundation, Inc.
5 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
6 Rewritten by Jason Merrill (jason@cygnus.com).
8 This file is part of GCC.
10 GCC is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3, or (at your option)
15 GCC is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with GCC; see the file COPYING3. If not see
22 <http://www.gnu.org/licenses/>. */
24 /* Known bugs or deficiencies include:
26 all methods must be provided in header files; can't use a source
27 file that contains only the method templates and "just win". */
31 #include "coretypes.h"
35 #include "pointer-set.h"
38 #include "c-family/c-common.h"
39 #include "c-family/c-objc.h"
40 #include "cp-objcp-common.h"
41 #include "tree-inline.h"
46 #include "tree-iterator.h"
49 /* The type of functions taking a tree, and some additional data, and
51 typedef int (*tree_fn_t) (tree, void*);
53 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
54 instantiations have been deferred, either because their definitions
55 were not yet available, or because we were putting off doing the work. */
56 struct GTY ((chain_next ("%h.next"))) pending_template {
57 struct pending_template *next;
58 struct tinst_level *tinst;
61 static GTY(()) struct pending_template *pending_templates;
62 static GTY(()) struct pending_template *last_pending_template;
64 int processing_template_parmlist;
65 static int template_header_count;
67 static GTY(()) tree saved_trees;
68 static VEC(int,heap) *inline_parm_levels;
70 static GTY(()) struct tinst_level *current_tinst_level;
72 static GTY(()) tree saved_access_scope;
74 /* Live only within one (recursive) call to tsubst_expr. We use
75 this to pass the statement expression node from the STMT_EXPR
76 to the EXPR_STMT that is its result. */
77 static tree cur_stmt_expr;
79 /* A map from local variable declarations in the body of the template
80 presently being instantiated to the corresponding instantiated
82 static htab_t local_specializations;
84 typedef struct GTY(()) spec_entry
91 static GTY ((param_is (spec_entry)))
92 htab_t decl_specializations;
94 static GTY ((param_is (spec_entry)))
95 htab_t type_specializations;
97 /* Contains canonical template parameter types. The vector is indexed by
98 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
99 TREE_LIST, whose TREE_VALUEs contain the canonical template
100 parameters of various types and levels. */
101 static GTY(()) VEC(tree,gc) *canonical_template_parms;
103 #define UNIFY_ALLOW_NONE 0
104 #define UNIFY_ALLOW_MORE_CV_QUAL 1
105 #define UNIFY_ALLOW_LESS_CV_QUAL 2
106 #define UNIFY_ALLOW_DERIVED 4
107 #define UNIFY_ALLOW_INTEGER 8
108 #define UNIFY_ALLOW_OUTER_LEVEL 16
109 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
110 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
112 enum template_base_result {
114 tbr_ambiguous_baseclass,
118 static void push_access_scope (tree);
119 static void pop_access_scope (tree);
120 static void push_deduction_access_scope (tree);
121 static void pop_deduction_access_scope (tree);
122 static bool resolve_overloaded_unification (tree, tree, tree, tree,
123 unification_kind_t, int,
125 static int try_one_overload (tree, tree, tree, tree, tree,
126 unification_kind_t, int, bool, bool);
127 static int unify (tree, tree, tree, tree, int, bool);
128 static void add_pending_template (tree);
129 static tree reopen_tinst_level (struct tinst_level *);
130 static tree tsubst_initializer_list (tree, tree);
131 static tree get_class_bindings (tree, tree, tree);
132 static tree coerce_template_parms (tree, tree, tree, tsubst_flags_t,
134 static void tsubst_enum (tree, tree, tree);
135 static tree add_to_template_args (tree, tree);
136 static tree add_outermost_template_args (tree, tree);
137 static bool check_instantiated_args (tree, tree, tsubst_flags_t);
138 static int maybe_adjust_types_for_deduction (unification_kind_t, tree*, tree*,
140 static int type_unification_real (tree, tree, tree, const tree *,
141 unsigned int, int, unification_kind_t, int,
143 static void note_template_header (int);
144 static tree convert_nontype_argument_function (tree, tree);
145 static tree convert_nontype_argument (tree, tree, tsubst_flags_t);
146 static tree convert_template_argument (tree, tree, tree,
147 tsubst_flags_t, int, tree);
148 static int for_each_template_parm (tree, tree_fn_t, void*,
149 struct pointer_set_t*, bool);
150 static tree expand_template_argument_pack (tree);
151 static tree build_template_parm_index (int, int, int, int, tree, tree);
152 static bool inline_needs_template_parms (tree);
153 static void push_inline_template_parms_recursive (tree, int);
154 static tree retrieve_local_specialization (tree);
155 static void register_local_specialization (tree, tree);
156 static hashval_t hash_specialization (const void *p);
157 static tree reduce_template_parm_level (tree, tree, int, tree, tsubst_flags_t);
158 static int mark_template_parm (tree, void *);
159 static int template_parm_this_level_p (tree, void *);
160 static tree tsubst_friend_function (tree, tree);
161 static tree tsubst_friend_class (tree, tree);
162 static int can_complete_type_without_circularity (tree);
163 static tree get_bindings (tree, tree, tree, bool);
164 static int template_decl_level (tree);
165 static int check_cv_quals_for_unify (int, tree, tree);
166 static void template_parm_level_and_index (tree, int*, int*);
167 static int unify_pack_expansion (tree, tree, tree,
168 tree, unification_kind_t, bool, bool);
169 static tree tsubst_template_arg (tree, tree, tsubst_flags_t, tree);
170 static tree tsubst_template_args (tree, tree, tsubst_flags_t, tree);
171 static tree tsubst_template_parms (tree, tree, tsubst_flags_t);
172 static void regenerate_decl_from_template (tree, tree);
173 static tree most_specialized_class (tree, tree, tsubst_flags_t);
174 static tree tsubst_aggr_type (tree, tree, tsubst_flags_t, tree, int);
175 static tree tsubst_arg_types (tree, tree, tsubst_flags_t, tree);
176 static tree tsubst_function_type (tree, tree, tsubst_flags_t, tree);
177 static bool check_specialization_scope (void);
178 static tree process_partial_specialization (tree);
179 static void set_current_access_from_decl (tree);
180 static enum template_base_result get_template_base (tree, tree, tree, tree,
182 static tree try_class_unification (tree, tree, tree, tree, bool);
183 static int coerce_template_template_parms (tree, tree, tsubst_flags_t,
185 static bool template_template_parm_bindings_ok_p (tree, tree);
186 static int template_args_equal (tree, tree);
187 static void tsubst_default_arguments (tree);
188 static tree for_each_template_parm_r (tree *, int *, void *);
189 static tree copy_default_args_to_explicit_spec_1 (tree, tree);
190 static void copy_default_args_to_explicit_spec (tree);
191 static int invalid_nontype_parm_type_p (tree, tsubst_flags_t);
192 static int eq_local_specializations (const void *, const void *);
193 static bool dependent_template_arg_p (tree);
194 static bool any_template_arguments_need_structural_equality_p (tree);
195 static bool dependent_type_p_r (tree);
196 static tree tsubst_expr (tree, tree, tsubst_flags_t, tree, bool);
197 static tree tsubst_copy (tree, tree, tsubst_flags_t, tree);
198 static tree tsubst_pack_expansion (tree, tree, tsubst_flags_t, tree);
199 static tree tsubst_decl (tree, tree, tsubst_flags_t);
200 static void perform_typedefs_access_check (tree tmpl, tree targs);
201 static void append_type_to_template_for_access_check_1 (tree, tree, tree,
203 static tree listify (tree);
204 static tree listify_autos (tree, tree);
205 static tree template_parm_to_arg (tree t);
206 static bool arg_from_parm_pack_p (tree, tree);
207 static tree current_template_args (void);
208 static tree fixup_template_type_parm_type (tree, int);
209 static tree fixup_template_parm_index (tree, tree, int);
210 static tree tsubst_template_parm (tree, tree, tsubst_flags_t);
212 /* Make the current scope suitable for access checking when we are
213 processing T. T can be FUNCTION_DECL for instantiated function
214 template, or VAR_DECL for static member variable (need by
215 instantiate_decl). */
218 push_access_scope (tree t)
220 gcc_assert (TREE_CODE (t) == FUNCTION_DECL
221 || TREE_CODE (t) == VAR_DECL);
223 if (DECL_FRIEND_CONTEXT (t))
224 push_nested_class (DECL_FRIEND_CONTEXT (t));
225 else if (DECL_CLASS_SCOPE_P (t))
226 push_nested_class (DECL_CONTEXT (t));
228 push_to_top_level ();
230 if (TREE_CODE (t) == FUNCTION_DECL)
232 saved_access_scope = tree_cons
233 (NULL_TREE, current_function_decl, saved_access_scope);
234 current_function_decl = t;
238 /* Restore the scope set up by push_access_scope. T is the node we
242 pop_access_scope (tree t)
244 if (TREE_CODE (t) == FUNCTION_DECL)
246 current_function_decl = TREE_VALUE (saved_access_scope);
247 saved_access_scope = TREE_CHAIN (saved_access_scope);
250 if (DECL_FRIEND_CONTEXT (t) || DECL_CLASS_SCOPE_P (t))
253 pop_from_top_level ();
256 /* Do any processing required when DECL (a member template
257 declaration) is finished. Returns the TEMPLATE_DECL corresponding
258 to DECL, unless it is a specialization, in which case the DECL
259 itself is returned. */
262 finish_member_template_decl (tree decl)
264 if (decl == error_mark_node)
265 return error_mark_node;
267 gcc_assert (DECL_P (decl));
269 if (TREE_CODE (decl) == TYPE_DECL)
273 type = TREE_TYPE (decl);
274 if (type == error_mark_node)
275 return error_mark_node;
276 if (MAYBE_CLASS_TYPE_P (type)
277 && CLASSTYPE_TEMPLATE_INFO (type)
278 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
280 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
281 check_member_template (tmpl);
286 else if (TREE_CODE (decl) == FIELD_DECL)
287 error ("data member %qD cannot be a member template", decl);
288 else if (DECL_TEMPLATE_INFO (decl))
290 if (!DECL_TEMPLATE_SPECIALIZATION (decl))
292 check_member_template (DECL_TI_TEMPLATE (decl));
293 return DECL_TI_TEMPLATE (decl);
299 error ("invalid member template declaration %qD", decl);
301 return error_mark_node;
304 /* Create a template info node. */
307 build_template_info (tree template_decl, tree template_args)
309 tree result = make_node (TEMPLATE_INFO);
310 TI_TEMPLATE (result) = template_decl;
311 TI_ARGS (result) = template_args;
315 /* Return the template info node corresponding to T, whatever T is. */
318 get_template_info (const_tree t)
320 tree tinfo = NULL_TREE;
322 if (!t || t == error_mark_node)
325 if (DECL_P (t) && DECL_LANG_SPECIFIC (t))
326 tinfo = DECL_TEMPLATE_INFO (t);
328 if (!tinfo && DECL_IMPLICIT_TYPEDEF_P (t))
331 if (TAGGED_TYPE_P (t))
332 tinfo = TYPE_TEMPLATE_INFO (t);
333 else if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
334 tinfo = TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (t);
339 /* Returns the template nesting level of the indicated class TYPE.
349 A<T>::B<U> has depth two, while A<T> has depth one.
350 Both A<T>::B<int> and A<int>::B<U> have depth one, if
351 they are instantiations, not specializations.
353 This function is guaranteed to return 0 if passed NULL_TREE so
354 that, for example, `template_class_depth (current_class_type)' is
358 template_class_depth (tree type)
363 type && TREE_CODE (type) != NAMESPACE_DECL;
364 type = (TREE_CODE (type) == FUNCTION_DECL)
365 ? CP_DECL_CONTEXT (type) : CP_TYPE_CONTEXT (type))
367 tree tinfo = get_template_info (type);
369 if (tinfo && PRIMARY_TEMPLATE_P (TI_TEMPLATE (tinfo))
370 && uses_template_parms (INNERMOST_TEMPLATE_ARGS (TI_ARGS (tinfo))))
377 /* Subroutine of maybe_begin_member_template_processing.
378 Returns true if processing DECL needs us to push template parms. */
381 inline_needs_template_parms (tree decl)
383 if (! DECL_TEMPLATE_INFO (decl))
386 return (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (most_general_template (decl)))
387 > (processing_template_decl + DECL_TEMPLATE_SPECIALIZATION (decl)));
390 /* Subroutine of maybe_begin_member_template_processing.
391 Push the template parms in PARMS, starting from LEVELS steps into the
392 chain, and ending at the beginning, since template parms are listed
396 push_inline_template_parms_recursive (tree parmlist, int levels)
398 tree parms = TREE_VALUE (parmlist);
402 push_inline_template_parms_recursive (TREE_CHAIN (parmlist), levels - 1);
404 ++processing_template_decl;
405 current_template_parms
406 = tree_cons (size_int (processing_template_decl),
407 parms, current_template_parms);
408 TEMPLATE_PARMS_FOR_INLINE (current_template_parms) = 1;
410 begin_scope (TREE_VEC_LENGTH (parms) ? sk_template_parms : sk_template_spec,
412 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
414 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
416 if (parm == error_mark_node)
419 gcc_assert (DECL_P (parm));
421 switch (TREE_CODE (parm))
430 /* Make a CONST_DECL as is done in process_template_parm.
431 It is ugly that we recreate this here; the original
432 version built in process_template_parm is no longer
434 tree decl = build_decl (DECL_SOURCE_LOCATION (parm),
435 CONST_DECL, DECL_NAME (parm),
437 DECL_ARTIFICIAL (decl) = 1;
438 TREE_CONSTANT (decl) = 1;
439 TREE_READONLY (decl) = 1;
440 DECL_INITIAL (decl) = DECL_INITIAL (parm);
441 SET_DECL_TEMPLATE_PARM_P (decl);
452 /* Restore the template parameter context for a member template or
453 a friend template defined in a class definition. */
456 maybe_begin_member_template_processing (tree decl)
461 if (inline_needs_template_parms (decl))
463 parms = DECL_TEMPLATE_PARMS (most_general_template (decl));
464 levels = TMPL_PARMS_DEPTH (parms) - processing_template_decl;
466 if (DECL_TEMPLATE_SPECIALIZATION (decl))
469 parms = TREE_CHAIN (parms);
472 push_inline_template_parms_recursive (parms, levels);
475 /* Remember how many levels of template parameters we pushed so that
476 we can pop them later. */
477 VEC_safe_push (int, heap, inline_parm_levels, levels);
480 /* Undo the effects of maybe_begin_member_template_processing. */
483 maybe_end_member_template_processing (void)
488 if (VEC_length (int, inline_parm_levels) == 0)
491 last = VEC_pop (int, inline_parm_levels);
492 for (i = 0; i < last; ++i)
494 --processing_template_decl;
495 current_template_parms = TREE_CHAIN (current_template_parms);
500 /* Return a new template argument vector which contains all of ARGS,
501 but has as its innermost set of arguments the EXTRA_ARGS. */
504 add_to_template_args (tree args, tree extra_args)
511 if (args == NULL_TREE || extra_args == error_mark_node)
514 extra_depth = TMPL_ARGS_DEPTH (extra_args);
515 new_args = make_tree_vec (TMPL_ARGS_DEPTH (args) + extra_depth);
517 for (i = 1; i <= TMPL_ARGS_DEPTH (args); ++i)
518 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (args, i));
520 for (j = 1; j <= extra_depth; ++j, ++i)
521 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (extra_args, j));
526 /* Like add_to_template_args, but only the outermost ARGS are added to
527 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
528 (EXTRA_ARGS) levels are added. This function is used to combine
529 the template arguments from a partial instantiation with the
530 template arguments used to attain the full instantiation from the
531 partial instantiation. */
534 add_outermost_template_args (tree args, tree extra_args)
538 /* If there are more levels of EXTRA_ARGS than there are ARGS,
539 something very fishy is going on. */
540 gcc_assert (TMPL_ARGS_DEPTH (args) >= TMPL_ARGS_DEPTH (extra_args));
542 /* If *all* the new arguments will be the EXTRA_ARGS, just return
544 if (TMPL_ARGS_DEPTH (args) == TMPL_ARGS_DEPTH (extra_args))
547 /* For the moment, we make ARGS look like it contains fewer levels. */
548 TREE_VEC_LENGTH (args) -= TMPL_ARGS_DEPTH (extra_args);
550 new_args = add_to_template_args (args, extra_args);
552 /* Now, we restore ARGS to its full dimensions. */
553 TREE_VEC_LENGTH (args) += TMPL_ARGS_DEPTH (extra_args);
558 /* Return the N levels of innermost template arguments from the ARGS. */
561 get_innermost_template_args (tree args, int n)
569 /* If N is 1, just return the innermost set of template arguments. */
571 return TMPL_ARGS_LEVEL (args, TMPL_ARGS_DEPTH (args));
573 /* If we're not removing anything, just return the arguments we were
575 extra_levels = TMPL_ARGS_DEPTH (args) - n;
576 gcc_assert (extra_levels >= 0);
577 if (extra_levels == 0)
580 /* Make a new set of arguments, not containing the outer arguments. */
581 new_args = make_tree_vec (n);
582 for (i = 1; i <= n; ++i)
583 SET_TMPL_ARGS_LEVEL (new_args, i,
584 TMPL_ARGS_LEVEL (args, i + extra_levels));
589 /* The inverse of get_innermost_template_args: Return all but the innermost
590 EXTRA_LEVELS levels of template arguments from the ARGS. */
593 strip_innermost_template_args (tree args, int extra_levels)
596 int n = TMPL_ARGS_DEPTH (args) - extra_levels;
601 /* If N is 1, just return the outermost set of template arguments. */
603 return TMPL_ARGS_LEVEL (args, 1);
605 /* If we're not removing anything, just return the arguments we were
607 gcc_assert (extra_levels >= 0);
608 if (extra_levels == 0)
611 /* Make a new set of arguments, not containing the inner arguments. */
612 new_args = make_tree_vec (n);
613 for (i = 1; i <= n; ++i)
614 SET_TMPL_ARGS_LEVEL (new_args, i,
615 TMPL_ARGS_LEVEL (args, i));
620 /* We've got a template header coming up; push to a new level for storing
624 begin_template_parm_list (void)
626 /* We use a non-tag-transparent scope here, which causes pushtag to
627 put tags in this scope, rather than in the enclosing class or
628 namespace scope. This is the right thing, since we want
629 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
630 global template class, push_template_decl handles putting the
631 TEMPLATE_DECL into top-level scope. For a nested template class,
634 template <class T> struct S1 {
635 template <class T> struct S2 {};
638 pushtag contains special code to call pushdecl_with_scope on the
639 TEMPLATE_DECL for S2. */
640 begin_scope (sk_template_parms, NULL);
641 ++processing_template_decl;
642 ++processing_template_parmlist;
643 note_template_header (0);
646 /* This routine is called when a specialization is declared. If it is
647 invalid to declare a specialization here, an error is reported and
648 false is returned, otherwise this routine will return true. */
651 check_specialization_scope (void)
653 tree scope = current_scope ();
657 An explicit specialization shall be declared in the namespace of
658 which the template is a member, or, for member templates, in the
659 namespace of which the enclosing class or enclosing class
660 template is a member. An explicit specialization of a member
661 function, member class or static data member of a class template
662 shall be declared in the namespace of which the class template
664 if (scope && TREE_CODE (scope) != NAMESPACE_DECL)
666 error ("explicit specialization in non-namespace scope %qD", scope);
672 In an explicit specialization declaration for a member of a class
673 template or a member template that appears in namespace scope,
674 the member template and some of its enclosing class templates may
675 remain unspecialized, except that the declaration shall not
676 explicitly specialize a class member template if its enclosing
677 class templates are not explicitly specialized as well. */
678 if (current_template_parms)
680 error ("enclosing class templates are not explicitly specialized");
687 /* We've just seen template <>. */
690 begin_specialization (void)
692 begin_scope (sk_template_spec, NULL);
693 note_template_header (1);
694 return check_specialization_scope ();
697 /* Called at then end of processing a declaration preceded by
701 end_specialization (void)
704 reset_specialization ();
707 /* Any template <>'s that we have seen thus far are not referring to a
708 function specialization. */
711 reset_specialization (void)
713 processing_specialization = 0;
714 template_header_count = 0;
717 /* We've just seen a template header. If SPECIALIZATION is nonzero,
718 it was of the form template <>. */
721 note_template_header (int specialization)
723 processing_specialization = specialization;
724 template_header_count++;
727 /* We're beginning an explicit instantiation. */
730 begin_explicit_instantiation (void)
732 gcc_assert (!processing_explicit_instantiation);
733 processing_explicit_instantiation = true;
738 end_explicit_instantiation (void)
740 gcc_assert (processing_explicit_instantiation);
741 processing_explicit_instantiation = false;
744 /* An explicit specialization or partial specialization TMPL is being
745 declared. Check that the namespace in which the specialization is
746 occurring is permissible. Returns false iff it is invalid to
747 specialize TMPL in the current namespace. */
750 check_specialization_namespace (tree tmpl)
752 tree tpl_ns = decl_namespace_context (tmpl);
756 An explicit specialization shall be declared in the namespace of
757 which the template is a member, or, for member templates, in the
758 namespace of which the enclosing class or enclosing class
759 template is a member. An explicit specialization of a member
760 function, member class or static data member of a class template
761 shall be declared in the namespace of which the class template is
763 if (current_scope() != DECL_CONTEXT (tmpl)
764 && !at_namespace_scope_p ())
766 error ("specialization of %qD must appear at namespace scope", tmpl);
769 if (is_associated_namespace (current_namespace, tpl_ns))
770 /* Same or super-using namespace. */
774 permerror (input_location, "specialization of %qD in different namespace", tmpl);
775 permerror (input_location, " from definition of %q+#D", tmpl);
780 /* SPEC is an explicit instantiation. Check that it is valid to
781 perform this explicit instantiation in the current namespace. */
784 check_explicit_instantiation_namespace (tree spec)
788 /* DR 275: An explicit instantiation shall appear in an enclosing
789 namespace of its template. */
790 ns = decl_namespace_context (spec);
791 if (!is_ancestor (current_namespace, ns))
792 permerror (input_location, "explicit instantiation of %qD in namespace %qD "
793 "(which does not enclose namespace %qD)",
794 spec, current_namespace, ns);
797 /* The TYPE is being declared. If it is a template type, that means it
798 is a partial specialization. Do appropriate error-checking. */
801 maybe_process_partial_specialization (tree type)
805 if (type == error_mark_node)
806 return error_mark_node;
808 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
810 error ("name of class shadows template template parameter %qD",
812 return error_mark_node;
815 context = TYPE_CONTEXT (type);
817 if ((CLASS_TYPE_P (type) && CLASSTYPE_USE_TEMPLATE (type))
818 /* Consider non-class instantiations of alias templates as
821 && TYPE_TEMPLATE_INFO (type)
822 && DECL_LANG_SPECIFIC (TYPE_NAME (type))
823 && DECL_USE_TEMPLATE (TYPE_NAME (type))))
825 /* This is for ordinary explicit specialization and partial
826 specialization of a template class such as:
828 template <> class C<int>;
832 template <class T> class C<T*>;
834 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
836 if (CLASS_TYPE_P (type)
837 && CLASSTYPE_IMPLICIT_INSTANTIATION (type)
838 && !COMPLETE_TYPE_P (type))
840 check_specialization_namespace (CLASSTYPE_TI_TEMPLATE (type));
841 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
842 if (processing_template_decl)
844 if (push_template_decl (TYPE_MAIN_DECL (type))
846 return error_mark_node;
849 else if (CLASS_TYPE_P (type)
850 && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
851 error ("specialization of %qT after instantiation", type);
853 if (DECL_ALIAS_TEMPLATE_P (TYPE_TI_TEMPLATE (type)))
855 error ("partial specialization of alias template %qD",
856 TYPE_TI_TEMPLATE (type));
857 return error_mark_node;
860 else if (CLASS_TYPE_P (type)
861 && !CLASSTYPE_USE_TEMPLATE (type)
862 && CLASSTYPE_TEMPLATE_INFO (type)
863 && context && CLASS_TYPE_P (context)
864 && CLASSTYPE_TEMPLATE_INFO (context))
866 /* This is for an explicit specialization of member class
867 template according to [temp.expl.spec/18]:
869 template <> template <class U> class C<int>::D;
871 The context `C<int>' must be an implicit instantiation.
872 Otherwise this is just a member class template declared
875 template <> class C<int> { template <class U> class D; };
876 template <> template <class U> class C<int>::D;
878 In the first case, `C<int>::D' is a specialization of `C<T>::D'
879 while in the second case, `C<int>::D' is a primary template
880 and `C<T>::D' may not exist. */
882 if (CLASSTYPE_IMPLICIT_INSTANTIATION (context)
883 && !COMPLETE_TYPE_P (type))
886 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
888 if (current_namespace
889 != decl_namespace_context (tmpl))
891 permerror (input_location, "specializing %q#T in different namespace", type);
892 permerror (input_location, " from definition of %q+#D", tmpl);
895 /* Check for invalid specialization after instantiation:
897 template <> template <> class C<int>::D<int>;
898 template <> template <class U> class C<int>::D; */
900 for (t = DECL_TEMPLATE_INSTANTIATIONS (tmpl);
901 t; t = TREE_CHAIN (t))
903 tree inst = TREE_VALUE (t);
904 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (inst))
906 /* We already have a full specialization of this partial
907 instantiation. Reassign it to the new member
908 specialization template. */
913 elt.tmpl = most_general_template (tmpl);
914 elt.args = CLASSTYPE_TI_ARGS (inst);
917 htab_remove_elt (type_specializations, &elt);
920 elt.args = INNERMOST_TEMPLATE_ARGS (elt.args);
922 slot = htab_find_slot (type_specializations, &elt, INSERT);
923 entry = ggc_alloc_spec_entry ();
927 else if (COMPLETE_OR_OPEN_TYPE_P (inst))
928 /* But if we've had an implicit instantiation, that's a
929 problem ([temp.expl.spec]/6). */
930 error ("specialization %qT after instantiation %qT",
934 /* Mark TYPE as a specialization. And as a result, we only
935 have one level of template argument for the innermost
937 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
938 CLASSTYPE_TI_ARGS (type)
939 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type));
942 else if (processing_specialization)
944 /* Someday C++0x may allow for enum template specialization. */
945 if (cxx_dialect > cxx98 && TREE_CODE (type) == ENUMERAL_TYPE
946 && CLASS_TYPE_P (context) && CLASSTYPE_USE_TEMPLATE (context))
947 pedwarn (input_location, OPT_pedantic, "template specialization "
948 "of %qD not allowed by ISO C++", type);
951 error ("explicit specialization of non-template %qT", type);
952 return error_mark_node;
959 /* Returns nonzero if we can optimize the retrieval of specializations
960 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
961 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
964 optimize_specialization_lookup_p (tree tmpl)
966 return (DECL_FUNCTION_TEMPLATE_P (tmpl)
967 && DECL_CLASS_SCOPE_P (tmpl)
968 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
970 && CLASS_TYPE_P (DECL_CONTEXT (tmpl))
971 /* The optimized lookup depends on the fact that the
972 template arguments for the member function template apply
973 purely to the containing class, which is not true if the
974 containing class is an explicit or partial
976 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (tmpl))
977 && !DECL_MEMBER_TEMPLATE_P (tmpl)
978 && !DECL_CONV_FN_P (tmpl)
979 /* It is possible to have a template that is not a member
980 template and is not a member of a template class:
982 template <typename T>
983 struct S { friend A::f(); };
985 Here, the friend function is a template, but the context does
986 not have template information. The optimized lookup relies
987 on having ARGS be the template arguments for both the class
988 and the function template. */
989 && !DECL_FRIEND_P (DECL_TEMPLATE_RESULT (tmpl)));
992 /* Retrieve the specialization (in the sense of [temp.spec] - a
993 specialization is either an instantiation or an explicit
994 specialization) of TMPL for the given template ARGS. If there is
995 no such specialization, return NULL_TREE. The ARGS are a vector of
996 arguments, or a vector of vectors of arguments, in the case of
997 templates with more than one level of parameters.
999 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
1000 then we search for a partial specialization matching ARGS. This
1001 parameter is ignored if TMPL is not a class template. */
1004 retrieve_specialization (tree tmpl, tree args, hashval_t hash)
1006 if (args == error_mark_node)
1009 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
1011 /* There should be as many levels of arguments as there are
1012 levels of parameters. */
1013 gcc_assert (TMPL_ARGS_DEPTH (args)
1014 == TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl)));
1016 if (optimize_specialization_lookup_p (tmpl))
1018 tree class_template;
1019 tree class_specialization;
1020 VEC(tree,gc) *methods;
1024 /* The template arguments actually apply to the containing
1025 class. Find the class specialization with those
1027 class_template = CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (tmpl));
1028 class_specialization
1029 = retrieve_specialization (class_template, args, 0);
1030 if (!class_specialization)
1032 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
1033 for the specialization. */
1034 idx = class_method_index_for_fn (class_specialization, tmpl);
1037 /* Iterate through the methods with the indicated name, looking
1038 for the one that has an instance of TMPL. */
1039 methods = CLASSTYPE_METHOD_VEC (class_specialization);
1040 for (fns = VEC_index (tree, methods, idx); fns; fns = OVL_NEXT (fns))
1042 tree fn = OVL_CURRENT (fns);
1043 if (DECL_TEMPLATE_INFO (fn) && DECL_TI_TEMPLATE (fn) == tmpl
1044 /* using-declarations can add base methods to the method vec,
1045 and we don't want those here. */
1046 && DECL_CONTEXT (fn) == class_specialization)
1055 htab_t specializations;
1059 elt.spec = NULL_TREE;
1061 if (DECL_CLASS_TEMPLATE_P (tmpl))
1062 specializations = type_specializations;
1064 specializations = decl_specializations;
1067 hash = hash_specialization (&elt);
1068 found = (spec_entry *) htab_find_with_hash (specializations, &elt, hash);
1076 /* Like retrieve_specialization, but for local declarations. */
1079 retrieve_local_specialization (tree tmpl)
1083 if (local_specializations == NULL)
1086 spec = (tree) htab_find_with_hash (local_specializations, tmpl,
1087 htab_hash_pointer (tmpl));
1088 return spec ? TREE_PURPOSE (spec) : NULL_TREE;
1091 /* Returns nonzero iff DECL is a specialization of TMPL. */
1094 is_specialization_of (tree decl, tree tmpl)
1098 if (TREE_CODE (decl) == FUNCTION_DECL)
1102 t = DECL_TEMPLATE_INFO (t) ? DECL_TI_TEMPLATE (t) : NULL_TREE)
1108 gcc_assert (TREE_CODE (decl) == TYPE_DECL);
1110 for (t = TREE_TYPE (decl);
1112 t = CLASSTYPE_USE_TEMPLATE (t)
1113 ? TREE_TYPE (CLASSTYPE_TI_TEMPLATE (t)) : NULL_TREE)
1114 if (same_type_ignoring_top_level_qualifiers_p (t, TREE_TYPE (tmpl)))
1121 /* Returns nonzero iff DECL is a specialization of friend declaration
1122 FRIEND_DECL according to [temp.friend]. */
1125 is_specialization_of_friend (tree decl, tree friend_decl)
1127 bool need_template = true;
1130 gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
1131 || TREE_CODE (decl) == TYPE_DECL);
1133 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1134 of a template class, we want to check if DECL is a specialization
1136 if (TREE_CODE (friend_decl) == FUNCTION_DECL
1137 && DECL_TEMPLATE_INFO (friend_decl)
1138 && !DECL_USE_TEMPLATE (friend_decl))
1140 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1141 friend_decl = DECL_TI_TEMPLATE (friend_decl);
1142 need_template = false;
1144 else if (TREE_CODE (friend_decl) == TEMPLATE_DECL
1145 && !PRIMARY_TEMPLATE_P (friend_decl))
1146 need_template = false;
1148 /* There is nothing to do if this is not a template friend. */
1149 if (TREE_CODE (friend_decl) != TEMPLATE_DECL)
1152 if (is_specialization_of (decl, friend_decl))
1156 A member of a class template may be declared to be a friend of a
1157 non-template class. In this case, the corresponding member of
1158 every specialization of the class template is a friend of the
1159 class granting friendship.
1161 For example, given a template friend declaration
1163 template <class T> friend void A<T>::f();
1165 the member function below is considered a friend
1167 template <> struct A<int> {
1171 For this type of template friend, TEMPLATE_DEPTH below will be
1172 nonzero. To determine if DECL is a friend of FRIEND, we first
1173 check if the enclosing class is a specialization of another. */
1175 template_depth = template_class_depth (CP_DECL_CONTEXT (friend_decl));
1177 && DECL_CLASS_SCOPE_P (decl)
1178 && is_specialization_of (TYPE_NAME (DECL_CONTEXT (decl)),
1179 CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (friend_decl))))
1181 /* Next, we check the members themselves. In order to handle
1182 a few tricky cases, such as when FRIEND_DECL's are
1184 template <class T> friend void A<T>::g(T t);
1185 template <class T> template <T t> friend void A<T>::h();
1189 void A<int>::g(int);
1190 template <int> void A<int>::h();
1192 we need to figure out ARGS, the template arguments from
1193 the context of DECL. This is required for template substitution
1194 of `T' in the function parameter of `g' and template parameter
1195 of `h' in the above examples. Here ARGS corresponds to `int'. */
1197 tree context = DECL_CONTEXT (decl);
1198 tree args = NULL_TREE;
1199 int current_depth = 0;
1201 while (current_depth < template_depth)
1203 if (CLASSTYPE_TEMPLATE_INFO (context))
1205 if (current_depth == 0)
1206 args = TYPE_TI_ARGS (context);
1208 args = add_to_template_args (TYPE_TI_ARGS (context), args);
1211 context = TYPE_CONTEXT (context);
1214 if (TREE_CODE (decl) == FUNCTION_DECL)
1219 tree friend_args_type;
1220 tree decl_args_type;
1222 /* Make sure that both DECL and FRIEND_DECL are templates or
1224 is_template = DECL_TEMPLATE_INFO (decl)
1225 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (decl));
1226 if (need_template ^ is_template)
1228 else if (is_template)
1230 /* If both are templates, check template parameter list. */
1232 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1234 if (!comp_template_parms
1235 (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (decl)),
1239 decl_type = TREE_TYPE (DECL_TI_TEMPLATE (decl));
1242 decl_type = TREE_TYPE (decl);
1244 friend_type = tsubst_function_type (TREE_TYPE (friend_decl), args,
1245 tf_none, NULL_TREE);
1246 if (friend_type == error_mark_node)
1249 /* Check if return types match. */
1250 if (!same_type_p (TREE_TYPE (decl_type), TREE_TYPE (friend_type)))
1253 /* Check if function parameter types match, ignoring the
1254 `this' parameter. */
1255 friend_args_type = TYPE_ARG_TYPES (friend_type);
1256 decl_args_type = TYPE_ARG_TYPES (decl_type);
1257 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (friend_decl))
1258 friend_args_type = TREE_CHAIN (friend_args_type);
1259 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1260 decl_args_type = TREE_CHAIN (decl_args_type);
1262 return compparms (decl_args_type, friend_args_type);
1266 /* DECL is a TYPE_DECL */
1268 tree decl_type = TREE_TYPE (decl);
1270 /* Make sure that both DECL and FRIEND_DECL are templates or
1273 = CLASSTYPE_TEMPLATE_INFO (decl_type)
1274 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (decl_type));
1276 if (need_template ^ is_template)
1278 else if (is_template)
1281 /* If both are templates, check the name of the two
1282 TEMPLATE_DECL's first because is_friend didn't. */
1283 if (DECL_NAME (CLASSTYPE_TI_TEMPLATE (decl_type))
1284 != DECL_NAME (friend_decl))
1287 /* Now check template parameter list. */
1289 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1291 return comp_template_parms
1292 (DECL_TEMPLATE_PARMS (CLASSTYPE_TI_TEMPLATE (decl_type)),
1296 return (DECL_NAME (decl)
1297 == DECL_NAME (friend_decl));
1303 /* Register the specialization SPEC as a specialization of TMPL with
1304 the indicated ARGS. IS_FRIEND indicates whether the specialization
1305 is actually just a friend declaration. Returns SPEC, or an
1306 equivalent prior declaration, if available. */
1309 register_specialization (tree spec, tree tmpl, tree args, bool is_friend,
1316 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL && DECL_P (spec));
1318 if (TREE_CODE (spec) == FUNCTION_DECL
1319 && uses_template_parms (DECL_TI_ARGS (spec)))
1320 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1321 register it; we want the corresponding TEMPLATE_DECL instead.
1322 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1323 the more obvious `uses_template_parms (spec)' to avoid problems
1324 with default function arguments. In particular, given
1325 something like this:
1327 template <class T> void f(T t1, T t = T())
1329 the default argument expression is not substituted for in an
1330 instantiation unless and until it is actually needed. */
1333 if (optimize_specialization_lookup_p (tmpl))
1334 /* We don't put these specializations in the hash table, but we might
1335 want to give an error about a mismatch. */
1336 fn = retrieve_specialization (tmpl, args, 0);
1344 hash = hash_specialization (&elt);
1347 htab_find_slot_with_hash (decl_specializations, &elt, hash, INSERT);
1349 fn = ((spec_entry *) *slot)->spec;
1354 /* We can sometimes try to re-register a specialization that we've
1355 already got. In particular, regenerate_decl_from_template calls
1356 duplicate_decls which will update the specialization list. But,
1357 we'll still get called again here anyhow. It's more convenient
1358 to simply allow this than to try to prevent it. */
1361 else if (fn && DECL_TEMPLATE_SPECIALIZATION (spec))
1363 if (DECL_TEMPLATE_INSTANTIATION (fn))
1365 if (DECL_ODR_USED (fn)
1366 || DECL_EXPLICIT_INSTANTIATION (fn))
1368 error ("specialization of %qD after instantiation",
1370 return error_mark_node;
1375 /* This situation should occur only if the first
1376 specialization is an implicit instantiation, the
1377 second is an explicit specialization, and the
1378 implicit instantiation has not yet been used. That
1379 situation can occur if we have implicitly
1380 instantiated a member function and then specialized
1383 We can also wind up here if a friend declaration that
1384 looked like an instantiation turns out to be a
1387 template <class T> void foo(T);
1388 class S { friend void foo<>(int) };
1389 template <> void foo(int);
1391 We transform the existing DECL in place so that any
1392 pointers to it become pointers to the updated
1395 If there was a definition for the template, but not
1396 for the specialization, we want this to look as if
1397 there were no definition, and vice versa. */
1398 DECL_INITIAL (fn) = NULL_TREE;
1399 duplicate_decls (spec, fn, is_friend);
1400 /* The call to duplicate_decls will have applied
1403 An explicit specialization of a function template
1404 is inline only if it is explicitly declared to be,
1405 and independently of whether its function template
1408 to the primary function; now copy the inline bits to
1409 the various clones. */
1410 FOR_EACH_CLONE (clone, fn)
1412 DECL_DECLARED_INLINE_P (clone)
1413 = DECL_DECLARED_INLINE_P (fn);
1414 DECL_SOURCE_LOCATION (clone)
1415 = DECL_SOURCE_LOCATION (fn);
1417 check_specialization_namespace (fn);
1422 else if (DECL_TEMPLATE_SPECIALIZATION (fn))
1424 if (!duplicate_decls (spec, fn, is_friend) && DECL_INITIAL (spec))
1425 /* Dup decl failed, but this is a new definition. Set the
1426 line number so any errors match this new
1428 DECL_SOURCE_LOCATION (fn) = DECL_SOURCE_LOCATION (spec);
1434 return duplicate_decls (spec, fn, is_friend);
1436 /* A specialization must be declared in the same namespace as the
1437 template it is specializing. */
1438 if (DECL_TEMPLATE_SPECIALIZATION (spec)
1439 && !check_specialization_namespace (tmpl))
1440 DECL_CONTEXT (spec) = DECL_CONTEXT (tmpl);
1442 if (slot != NULL /* !optimize_specialization_lookup_p (tmpl) */)
1444 spec_entry *entry = ggc_alloc_spec_entry ();
1445 gcc_assert (tmpl && args && spec);
1448 if (TREE_CODE (spec) == FUNCTION_DECL && DECL_NAMESPACE_SCOPE_P (spec)
1449 && PRIMARY_TEMPLATE_P (tmpl)
1450 && DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (tmpl)) == NULL_TREE)
1451 /* TMPL is a forward declaration of a template function; keep a list
1452 of all specializations in case we need to reassign them to a friend
1453 template later in tsubst_friend_function. */
1454 DECL_TEMPLATE_INSTANTIATIONS (tmpl)
1455 = tree_cons (args, spec, DECL_TEMPLATE_INSTANTIATIONS (tmpl));
1461 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1462 TMPL and ARGS members, ignores SPEC. */
1465 eq_specializations (const void *p1, const void *p2)
1467 const spec_entry *e1 = (const spec_entry *)p1;
1468 const spec_entry *e2 = (const spec_entry *)p2;
1470 return (e1->tmpl == e2->tmpl
1471 && comp_template_args (e1->args, e2->args));
1474 /* Returns a hash for a template TMPL and template arguments ARGS. */
1477 hash_tmpl_and_args (tree tmpl, tree args)
1479 hashval_t val = DECL_UID (tmpl);
1480 return iterative_hash_template_arg (args, val);
1483 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1487 hash_specialization (const void *p)
1489 const spec_entry *e = (const spec_entry *)p;
1490 return hash_tmpl_and_args (e->tmpl, e->args);
1493 /* Recursively calculate a hash value for a template argument ARG, for use
1494 in the hash tables of template specializations. */
1497 iterative_hash_template_arg (tree arg, hashval_t val)
1499 unsigned HOST_WIDE_INT i;
1500 enum tree_code code;
1503 if (arg == NULL_TREE)
1504 return iterative_hash_object (arg, val);
1509 if (TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
1510 /* We can get one of these when re-hashing a previous entry in the middle
1511 of substituting into a pack expansion. Just look through it. */
1512 arg = ARGUMENT_PACK_SELECT_FROM_PACK (arg);
1514 code = TREE_CODE (arg);
1515 tclass = TREE_CODE_CLASS (code);
1517 val = iterative_hash_object (code, val);
1524 case IDENTIFIER_NODE:
1525 return iterative_hash_object (IDENTIFIER_HASH_VALUE (arg), val);
1529 int i, len = TREE_VEC_LENGTH (arg);
1530 for (i = 0; i < len; ++i)
1531 val = iterative_hash_template_arg (TREE_VEC_ELT (arg, i), val);
1535 case TYPE_PACK_EXPANSION:
1536 case EXPR_PACK_EXPANSION:
1537 return iterative_hash_template_arg (PACK_EXPANSION_PATTERN (arg), val);
1539 case TYPE_ARGUMENT_PACK:
1540 case NONTYPE_ARGUMENT_PACK:
1541 return iterative_hash_template_arg (ARGUMENT_PACK_ARGS (arg), val);
1544 for (; arg; arg = TREE_CHAIN (arg))
1545 val = iterative_hash_template_arg (TREE_VALUE (arg), val);
1549 for (; arg; arg = OVL_NEXT (arg))
1550 val = iterative_hash_template_arg (OVL_CURRENT (arg), val);
1556 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg), i, field, value)
1558 val = iterative_hash_template_arg (field, val);
1559 val = iterative_hash_template_arg (value, val);
1565 if (!DECL_ARTIFICIAL (arg))
1567 val = iterative_hash_object (DECL_PARM_INDEX (arg), val);
1568 val = iterative_hash_object (DECL_PARM_LEVEL (arg), val);
1570 return iterative_hash_template_arg (TREE_TYPE (arg), val);
1573 return iterative_hash_template_arg (TARGET_EXPR_INITIAL (arg), val);
1576 val = iterative_hash_template_arg (PTRMEM_CST_CLASS (arg), val);
1577 return iterative_hash_template_arg (PTRMEM_CST_MEMBER (arg), val);
1579 case TEMPLATE_PARM_INDEX:
1580 val = iterative_hash_template_arg
1581 (TREE_TYPE (TEMPLATE_PARM_DECL (arg)), val);
1582 val = iterative_hash_object (TEMPLATE_PARM_LEVEL (arg), val);
1583 return iterative_hash_object (TEMPLATE_PARM_IDX (arg), val);
1586 val = iterative_hash_object (TRAIT_EXPR_KIND (arg), val);
1587 val = iterative_hash_template_arg (TRAIT_EXPR_TYPE1 (arg), val);
1588 return iterative_hash_template_arg (TRAIT_EXPR_TYPE2 (arg), val);
1591 val = iterative_hash_template_arg (BINFO_TYPE (BASELINK_BINFO (arg)),
1593 return iterative_hash_template_arg (DECL_NAME (get_first_fn (arg)),
1597 val = iterative_hash_template_arg (TREE_OPERAND (arg, 0), val);
1598 code = TREE_CODE (TREE_OPERAND (arg, 1));
1599 val = iterative_hash_object (code, val);
1600 return iterative_hash_template_arg (TREE_OPERAND (arg, 2), val);
1603 /* A lambda can't appear in a template arg, but don't crash on
1605 gcc_assert (seen_error ());
1609 case IMPLICIT_CONV_EXPR:
1610 case STATIC_CAST_EXPR:
1611 case REINTERPRET_CAST_EXPR:
1612 case CONST_CAST_EXPR:
1613 case DYNAMIC_CAST_EXPR:
1615 val = iterative_hash_template_arg (TREE_TYPE (arg), val);
1616 /* Now hash operands as usual. */
1626 if (TYPE_CANONICAL (arg))
1627 return iterative_hash_object (TYPE_HASH (TYPE_CANONICAL (arg)),
1629 else if (TREE_CODE (arg) == DECLTYPE_TYPE)
1630 return iterative_hash_template_arg (DECLTYPE_TYPE_EXPR (arg), val);
1631 /* Otherwise just compare the types during lookup. */
1634 case tcc_declaration:
1636 return iterative_hash_expr (arg, val);
1639 gcc_assert (IS_EXPR_CODE_CLASS (tclass));
1641 unsigned n = cp_tree_operand_length (arg);
1642 for (i = 0; i < n; ++i)
1643 val = iterative_hash_template_arg (TREE_OPERAND (arg, i), val);
1651 /* Unregister the specialization SPEC as a specialization of TMPL.
1652 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1653 if the SPEC was listed as a specialization of TMPL.
1655 Note that SPEC has been ggc_freed, so we can't look inside it. */
1658 reregister_specialization (tree spec, tree tinfo, tree new_spec)
1663 elt.tmpl = most_general_template (TI_TEMPLATE (tinfo));
1664 elt.args = TI_ARGS (tinfo);
1665 elt.spec = NULL_TREE;
1667 entry = (spec_entry *) htab_find (decl_specializations, &elt);
1670 gcc_assert (entry->spec == spec || entry->spec == new_spec);
1671 gcc_assert (new_spec != NULL_TREE);
1672 entry->spec = new_spec;
1679 /* Compare an entry in the local specializations hash table P1 (which
1680 is really a pointer to a TREE_LIST) with P2 (which is really a
1684 eq_local_specializations (const void *p1, const void *p2)
1686 return TREE_VALUE ((const_tree) p1) == (const_tree) p2;
1689 /* Hash P1, an entry in the local specializations table. */
1692 hash_local_specialization (const void* p1)
1694 return htab_hash_pointer (TREE_VALUE ((const_tree) p1));
1697 /* Like register_specialization, but for local declarations. We are
1698 registering SPEC, an instantiation of TMPL. */
1701 register_local_specialization (tree spec, tree tmpl)
1705 slot = htab_find_slot_with_hash (local_specializations, tmpl,
1706 htab_hash_pointer (tmpl), INSERT);
1707 *slot = build_tree_list (spec, tmpl);
1710 /* TYPE is a class type. Returns true if TYPE is an explicitly
1711 specialized class. */
1714 explicit_class_specialization_p (tree type)
1716 if (!CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
1718 return !uses_template_parms (CLASSTYPE_TI_ARGS (type));
1721 /* Print the list of functions at FNS, going through all the overloads
1722 for each element of the list. Alternatively, FNS can not be a
1723 TREE_LIST, in which case it will be printed together with all the
1726 MORE and *STR should respectively be FALSE and NULL when the function
1727 is called from the outside. They are used internally on recursive
1728 calls. print_candidates manages the two parameters and leaves NULL
1729 in *STR when it ends. */
1732 print_candidates_1 (tree fns, bool more, const char **str)
1735 char *spaces = NULL;
1737 for (fn = fns; fn; fn = OVL_NEXT (fn))
1738 if (TREE_CODE (fn) == TREE_LIST)
1740 for (fn2 = fn; fn2 != NULL_TREE; fn2 = TREE_CHAIN (fn2))
1741 print_candidates_1 (TREE_VALUE (fn2),
1742 TREE_CHAIN (fn2) || more, str);
1748 /* Pick the prefix string. */
1749 if (!more && !OVL_NEXT (fns))
1751 error ("candidate is: %+#D", OVL_CURRENT (fn));
1755 *str = _("candidates are:");
1756 spaces = get_spaces (*str);
1758 error ("%s %+#D", *str, OVL_CURRENT (fn));
1759 *str = spaces ? spaces : *str;
1769 /* Print the list of candidate FNS in an error message. FNS can also
1770 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1773 print_candidates (tree fns)
1775 const char *str = NULL;
1776 print_candidates_1 (fns, false, &str);
1777 gcc_assert (str == NULL);
1780 /* Returns the template (one of the functions given by TEMPLATE_ID)
1781 which can be specialized to match the indicated DECL with the
1782 explicit template args given in TEMPLATE_ID. The DECL may be
1783 NULL_TREE if none is available. In that case, the functions in
1784 TEMPLATE_ID are non-members.
1786 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1787 specialization of a member template.
1789 The TEMPLATE_COUNT is the number of references to qualifying
1790 template classes that appeared in the name of the function. See
1791 check_explicit_specialization for a more accurate description.
1793 TSK indicates what kind of template declaration (if any) is being
1794 declared. TSK_TEMPLATE indicates that the declaration given by
1795 DECL, though a FUNCTION_DECL, has template parameters, and is
1796 therefore a template function.
1798 The template args (those explicitly specified and those deduced)
1799 are output in a newly created vector *TARGS_OUT.
1801 If it is impossible to determine the result, an error message is
1802 issued. The error_mark_node is returned to indicate failure. */
1805 determine_specialization (tree template_id,
1808 int need_member_template,
1814 tree explicit_targs;
1815 tree candidates = NULL_TREE;
1816 /* A TREE_LIST of templates of which DECL may be a specialization.
1817 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1818 corresponding TREE_PURPOSE is the set of template arguments that,
1819 when used to instantiate the template, would produce a function
1820 with the signature of DECL. */
1821 tree templates = NULL_TREE;
1823 cp_binding_level *b;
1825 *targs_out = NULL_TREE;
1827 if (template_id == error_mark_node || decl == error_mark_node)
1828 return error_mark_node;
1830 fns = TREE_OPERAND (template_id, 0);
1831 explicit_targs = TREE_OPERAND (template_id, 1);
1833 if (fns == error_mark_node)
1834 return error_mark_node;
1836 /* Check for baselinks. */
1837 if (BASELINK_P (fns))
1838 fns = BASELINK_FUNCTIONS (fns);
1840 if (!is_overloaded_fn (fns))
1842 error ("%qD is not a function template", fns);
1843 return error_mark_node;
1846 /* Count the number of template headers specified for this
1849 for (b = current_binding_level;
1850 b->kind == sk_template_parms;
1854 for (; fns; fns = OVL_NEXT (fns))
1856 tree fn = OVL_CURRENT (fns);
1858 if (TREE_CODE (fn) == TEMPLATE_DECL)
1860 tree decl_arg_types;
1863 /* In case of explicit specialization, we need to check if
1864 the number of template headers appearing in the specialization
1865 is correct. This is usually done in check_explicit_specialization,
1866 but the check done there cannot be exhaustive when specializing
1867 member functions. Consider the following code:
1869 template <> void A<int>::f(int);
1870 template <> template <> void A<int>::f(int);
1872 Assuming that A<int> is not itself an explicit specialization
1873 already, the first line specializes "f" which is a non-template
1874 member function, whilst the second line specializes "f" which
1875 is a template member function. So both lines are syntactically
1876 correct, and check_explicit_specialization does not reject
1879 Here, we can do better, as we are matching the specialization
1880 against the declarations. We count the number of template
1881 headers, and we check if they match TEMPLATE_COUNT + 1
1882 (TEMPLATE_COUNT is the number of qualifying template classes,
1883 plus there must be another header for the member template
1886 Notice that if header_count is zero, this is not a
1887 specialization but rather a template instantiation, so there
1888 is no check we can perform here. */
1889 if (header_count && header_count != template_count + 1)
1892 /* Check that the number of template arguments at the
1893 innermost level for DECL is the same as for FN. */
1894 if (current_binding_level->kind == sk_template_parms
1895 && !current_binding_level->explicit_spec_p
1896 && (TREE_VEC_LENGTH (DECL_INNERMOST_TEMPLATE_PARMS (fn))
1897 != TREE_VEC_LENGTH (INNERMOST_TEMPLATE_PARMS
1898 (current_template_parms))))
1901 /* DECL might be a specialization of FN. */
1902 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1903 fn_arg_types = TYPE_ARG_TYPES (TREE_TYPE (fn));
1905 /* For a non-static member function, we need to make sure
1906 that the const qualification is the same. Since
1907 get_bindings does not try to merge the "this" parameter,
1908 we must do the comparison explicitly. */
1909 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
1910 && !same_type_p (TREE_VALUE (fn_arg_types),
1911 TREE_VALUE (decl_arg_types)))
1914 /* Skip the "this" parameter and, for constructors of
1915 classes with virtual bases, the VTT parameter. A
1916 full specialization of a constructor will have a VTT
1917 parameter, but a template never will. */
1919 = skip_artificial_parms_for (decl, decl_arg_types);
1921 = skip_artificial_parms_for (fn, fn_arg_types);
1923 /* Check that the number of function parameters matches.
1925 template <class T> void f(int i = 0);
1926 template <> void f<int>();
1927 The specialization f<int> is invalid but is not caught
1928 by get_bindings below. */
1929 if (list_length (fn_arg_types) != list_length (decl_arg_types))
1932 /* Function templates cannot be specializations; there are
1933 no partial specializations of functions. Therefore, if
1934 the type of DECL does not match FN, there is no
1936 if (tsk == tsk_template)
1938 if (compparms (fn_arg_types, decl_arg_types))
1939 candidates = tree_cons (NULL_TREE, fn, candidates);
1943 /* See whether this function might be a specialization of this
1945 targs = get_bindings (fn, decl, explicit_targs, /*check_ret=*/true);
1948 /* We cannot deduce template arguments that when used to
1949 specialize TMPL will produce DECL. */
1952 /* Save this template, and the arguments deduced. */
1953 templates = tree_cons (targs, fn, templates);
1955 else if (need_member_template)
1956 /* FN is an ordinary member function, and we need a
1957 specialization of a member template. */
1959 else if (TREE_CODE (fn) != FUNCTION_DECL)
1960 /* We can get IDENTIFIER_NODEs here in certain erroneous
1963 else if (!DECL_FUNCTION_MEMBER_P (fn))
1964 /* This is just an ordinary non-member function. Nothing can
1965 be a specialization of that. */
1967 else if (DECL_ARTIFICIAL (fn))
1968 /* Cannot specialize functions that are created implicitly. */
1972 tree decl_arg_types;
1974 /* This is an ordinary member function. However, since
1975 we're here, we can assume it's enclosing class is a
1976 template class. For example,
1978 template <typename T> struct S { void f(); };
1979 template <> void S<int>::f() {}
1981 Here, S<int>::f is a non-template, but S<int> is a
1982 template class. If FN has the same type as DECL, we
1983 might be in business. */
1985 if (!DECL_TEMPLATE_INFO (fn))
1986 /* Its enclosing class is an explicit specialization
1987 of a template class. This is not a candidate. */
1990 if (!same_type_p (TREE_TYPE (TREE_TYPE (decl)),
1991 TREE_TYPE (TREE_TYPE (fn))))
1992 /* The return types differ. */
1995 /* Adjust the type of DECL in case FN is a static member. */
1996 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1997 if (DECL_STATIC_FUNCTION_P (fn)
1998 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1999 decl_arg_types = TREE_CHAIN (decl_arg_types);
2001 if (compparms (TYPE_ARG_TYPES (TREE_TYPE (fn)),
2004 candidates = tree_cons (NULL_TREE, fn, candidates);
2008 if (templates && TREE_CHAIN (templates))
2014 It is possible for a specialization with a given function
2015 signature to be instantiated from more than one function
2016 template. In such cases, explicit specification of the
2017 template arguments must be used to uniquely identify the
2018 function template specialization being specialized.
2020 Note that here, there's no suggestion that we're supposed to
2021 determine which of the candidate templates is most
2022 specialized. However, we, also have:
2026 Partial ordering of overloaded function template
2027 declarations is used in the following contexts to select
2028 the function template to which a function template
2029 specialization refers:
2031 -- when an explicit specialization refers to a function
2034 So, we do use the partial ordering rules, at least for now.
2035 This extension can only serve to make invalid programs valid,
2036 so it's safe. And, there is strong anecdotal evidence that
2037 the committee intended the partial ordering rules to apply;
2038 the EDG front end has that behavior, and John Spicer claims
2039 that the committee simply forgot to delete the wording in
2040 [temp.expl.spec]. */
2041 tree tmpl = most_specialized_instantiation (templates);
2042 if (tmpl != error_mark_node)
2045 TREE_CHAIN (templates) = NULL_TREE;
2049 if (templates == NULL_TREE && candidates == NULL_TREE)
2051 error ("template-id %qD for %q+D does not match any template "
2052 "declaration", template_id, decl);
2053 if (header_count && header_count != template_count + 1)
2054 inform (input_location, "saw %d %<template<>%>, need %d for "
2055 "specializing a member function template",
2056 header_count, template_count + 1);
2057 return error_mark_node;
2059 else if ((templates && TREE_CHAIN (templates))
2060 || (candidates && TREE_CHAIN (candidates))
2061 || (templates && candidates))
2063 error ("ambiguous template specialization %qD for %q+D",
2065 candidates = chainon (candidates, templates);
2066 print_candidates (candidates);
2067 return error_mark_node;
2070 /* We have one, and exactly one, match. */
2073 tree fn = TREE_VALUE (candidates);
2074 *targs_out = copy_node (DECL_TI_ARGS (fn));
2075 /* DECL is a re-declaration or partial instantiation of a template
2077 if (TREE_CODE (fn) == TEMPLATE_DECL)
2079 /* It was a specialization of an ordinary member function in a
2081 return DECL_TI_TEMPLATE (fn);
2084 /* It was a specialization of a template. */
2085 targs = DECL_TI_ARGS (DECL_TEMPLATE_RESULT (TREE_VALUE (templates)));
2086 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (targs))
2088 *targs_out = copy_node (targs);
2089 SET_TMPL_ARGS_LEVEL (*targs_out,
2090 TMPL_ARGS_DEPTH (*targs_out),
2091 TREE_PURPOSE (templates));
2094 *targs_out = TREE_PURPOSE (templates);
2095 return TREE_VALUE (templates);
2098 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2099 but with the default argument values filled in from those in the
2103 copy_default_args_to_explicit_spec_1 (tree spec_types,
2106 tree new_spec_types;
2111 if (spec_types == void_list_node)
2112 return void_list_node;
2114 /* Substitute into the rest of the list. */
2116 copy_default_args_to_explicit_spec_1 (TREE_CHAIN (spec_types),
2117 TREE_CHAIN (tmpl_types));
2119 /* Add the default argument for this parameter. */
2120 return hash_tree_cons (TREE_PURPOSE (tmpl_types),
2121 TREE_VALUE (spec_types),
2125 /* DECL is an explicit specialization. Replicate default arguments
2126 from the template it specializes. (That way, code like:
2128 template <class T> void f(T = 3);
2129 template <> void f(double);
2132 works, as required.) An alternative approach would be to look up
2133 the correct default arguments at the call-site, but this approach
2134 is consistent with how implicit instantiations are handled. */
2137 copy_default_args_to_explicit_spec (tree decl)
2142 tree new_spec_types;
2146 tree object_type = NULL_TREE;
2147 tree in_charge = NULL_TREE;
2148 tree vtt = NULL_TREE;
2150 /* See if there's anything we need to do. */
2151 tmpl = DECL_TI_TEMPLATE (decl);
2152 tmpl_types = TYPE_ARG_TYPES (TREE_TYPE (DECL_TEMPLATE_RESULT (tmpl)));
2153 for (t = tmpl_types; t; t = TREE_CHAIN (t))
2154 if (TREE_PURPOSE (t))
2159 old_type = TREE_TYPE (decl);
2160 spec_types = TYPE_ARG_TYPES (old_type);
2162 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2164 /* Remove the this pointer, but remember the object's type for
2166 object_type = TREE_TYPE (TREE_VALUE (spec_types));
2167 spec_types = TREE_CHAIN (spec_types);
2168 tmpl_types = TREE_CHAIN (tmpl_types);
2170 if (DECL_HAS_IN_CHARGE_PARM_P (decl))
2172 /* DECL may contain more parameters than TMPL due to the extra
2173 in-charge parameter in constructors and destructors. */
2174 in_charge = spec_types;
2175 spec_types = TREE_CHAIN (spec_types);
2177 if (DECL_HAS_VTT_PARM_P (decl))
2180 spec_types = TREE_CHAIN (spec_types);
2184 /* Compute the merged default arguments. */
2186 copy_default_args_to_explicit_spec_1 (spec_types, tmpl_types);
2188 /* Compute the new FUNCTION_TYPE. */
2192 new_spec_types = hash_tree_cons (TREE_PURPOSE (vtt),
2197 /* Put the in-charge parameter back. */
2198 new_spec_types = hash_tree_cons (TREE_PURPOSE (in_charge),
2199 TREE_VALUE (in_charge),
2202 new_type = build_method_type_directly (object_type,
2203 TREE_TYPE (old_type),
2207 new_type = build_function_type (TREE_TYPE (old_type),
2209 new_type = cp_build_type_attribute_variant (new_type,
2210 TYPE_ATTRIBUTES (old_type));
2211 new_type = build_exception_variant (new_type,
2212 TYPE_RAISES_EXCEPTIONS (old_type));
2213 TREE_TYPE (decl) = new_type;
2216 /* Check to see if the function just declared, as indicated in
2217 DECLARATOR, and in DECL, is a specialization of a function
2218 template. We may also discover that the declaration is an explicit
2219 instantiation at this point.
2221 Returns DECL, or an equivalent declaration that should be used
2222 instead if all goes well. Issues an error message if something is
2223 amiss. Returns error_mark_node if the error is not easily
2226 FLAGS is a bitmask consisting of the following flags:
2228 2: The function has a definition.
2229 4: The function is a friend.
2231 The TEMPLATE_COUNT is the number of references to qualifying
2232 template classes that appeared in the name of the function. For
2235 template <class T> struct S { void f(); };
2238 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2239 classes are not counted in the TEMPLATE_COUNT, so that in
2241 template <class T> struct S {};
2242 template <> struct S<int> { void f(); }
2243 template <> void S<int>::f();
2245 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2246 invalid; there should be no template <>.)
2248 If the function is a specialization, it is marked as such via
2249 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2250 is set up correctly, and it is added to the list of specializations
2251 for that template. */
2254 check_explicit_specialization (tree declarator,
2259 int have_def = flags & 2;
2260 int is_friend = flags & 4;
2261 int specialization = 0;
2262 int explicit_instantiation = 0;
2263 int member_specialization = 0;
2264 tree ctype = DECL_CLASS_CONTEXT (decl);
2265 tree dname = DECL_NAME (decl);
2270 if (!processing_specialization)
2273 tsk = tsk_excessive_parms;
2276 tsk = current_tmpl_spec_kind (template_count);
2281 if (processing_specialization)
2284 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2286 else if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2289 /* This could be something like:
2291 template <class T> void f(T);
2292 class S { friend void f<>(int); } */
2296 /* This case handles bogus declarations like template <>
2297 template <class T> void f<int>(); */
2299 error ("template-id %qD in declaration of primary template",
2306 case tsk_invalid_member_spec:
2307 /* The error has already been reported in
2308 check_specialization_scope. */
2309 return error_mark_node;
2311 case tsk_invalid_expl_inst:
2312 error ("template parameter list used in explicit instantiation");
2318 error ("definition provided for explicit instantiation");
2320 explicit_instantiation = 1;
2323 case tsk_excessive_parms:
2324 case tsk_insufficient_parms:
2325 if (tsk == tsk_excessive_parms)
2326 error ("too many template parameter lists in declaration of %qD",
2328 else if (template_header_count)
2329 error("too few template parameter lists in declaration of %qD", decl);
2331 error("explicit specialization of %qD must be introduced by "
2332 "%<template <>%>", decl);
2336 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2338 member_specialization = 1;
2344 if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2346 /* This case handles bogus declarations like template <>
2347 template <class T> void f<int>(); */
2349 if (uses_template_parms (declarator))
2350 error ("function template partial specialization %qD "
2351 "is not allowed", declarator);
2353 error ("template-id %qD in declaration of primary template",
2358 if (ctype && CLASSTYPE_TEMPLATE_INSTANTIATION (ctype))
2359 /* This is a specialization of a member template, without
2360 specialization the containing class. Something like:
2362 template <class T> struct S {
2363 template <class U> void f (U);
2365 template <> template <class U> void S<int>::f(U) {}
2367 That's a specialization -- but of the entire template. */
2375 if (specialization || member_specialization)
2377 tree t = TYPE_ARG_TYPES (TREE_TYPE (decl));
2378 for (; t; t = TREE_CHAIN (t))
2379 if (TREE_PURPOSE (t))
2381 permerror (input_location,
2382 "default argument specified in explicit specialization");
2387 if (specialization || member_specialization || explicit_instantiation)
2389 tree tmpl = NULL_TREE;
2390 tree targs = NULL_TREE;
2392 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2393 if (TREE_CODE (declarator) != TEMPLATE_ID_EXPR)
2397 gcc_assert (TREE_CODE (declarator) == IDENTIFIER_NODE);
2402 /* If there is no class context, the explicit instantiation
2403 must be at namespace scope. */
2404 gcc_assert (DECL_NAMESPACE_SCOPE_P (decl));
2406 /* Find the namespace binding, using the declaration
2408 fns = lookup_qualified_name (CP_DECL_CONTEXT (decl), dname,
2410 if (fns == error_mark_node || !is_overloaded_fn (fns))
2412 error ("%qD is not a template function", dname);
2413 fns = error_mark_node;
2417 tree fn = OVL_CURRENT (fns);
2418 if (!is_associated_namespace (CP_DECL_CONTEXT (decl),
2419 CP_DECL_CONTEXT (fn)))
2420 error ("%qD is not declared in %qD",
2421 decl, current_namespace);
2425 declarator = lookup_template_function (fns, NULL_TREE);
2428 if (declarator == error_mark_node)
2429 return error_mark_node;
2431 if (ctype != NULL_TREE && TYPE_BEING_DEFINED (ctype))
2433 if (!explicit_instantiation)
2434 /* A specialization in class scope. This is invalid,
2435 but the error will already have been flagged by
2436 check_specialization_scope. */
2437 return error_mark_node;
2440 /* It's not valid to write an explicit instantiation in
2443 class C { template void f(); }
2445 This case is caught by the parser. However, on
2448 template class C { void f(); };
2450 (which is invalid) we can get here. The error will be
2457 else if (ctype != NULL_TREE
2458 && (TREE_CODE (TREE_OPERAND (declarator, 0)) ==
2461 /* Find the list of functions in ctype that have the same
2462 name as the declared function. */
2463 tree name = TREE_OPERAND (declarator, 0);
2464 tree fns = NULL_TREE;
2467 if (constructor_name_p (name, ctype))
2469 int is_constructor = DECL_CONSTRUCTOR_P (decl);
2471 if (is_constructor ? !TYPE_HAS_USER_CONSTRUCTOR (ctype)
2472 : !CLASSTYPE_DESTRUCTORS (ctype))
2474 /* From [temp.expl.spec]:
2476 If such an explicit specialization for the member
2477 of a class template names an implicitly-declared
2478 special member function (clause _special_), the
2479 program is ill-formed.
2481 Similar language is found in [temp.explicit]. */
2482 error ("specialization of implicitly-declared special member function");
2483 return error_mark_node;
2486 name = is_constructor ? ctor_identifier : dtor_identifier;
2489 if (!DECL_CONV_FN_P (decl))
2491 idx = lookup_fnfields_1 (ctype, name);
2493 fns = VEC_index (tree, CLASSTYPE_METHOD_VEC (ctype), idx);
2497 VEC(tree,gc) *methods;
2500 /* For a type-conversion operator, we cannot do a
2501 name-based lookup. We might be looking for `operator
2502 int' which will be a specialization of `operator T'.
2503 So, we find *all* the conversion operators, and then
2504 select from them. */
2507 methods = CLASSTYPE_METHOD_VEC (ctype);
2509 for (idx = CLASSTYPE_FIRST_CONVERSION_SLOT;
2510 VEC_iterate (tree, methods, idx, ovl);
2513 if (!DECL_CONV_FN_P (OVL_CURRENT (ovl)))
2514 /* There are no more conversion functions. */
2517 /* Glue all these conversion functions together
2518 with those we already have. */
2519 for (; ovl; ovl = OVL_NEXT (ovl))
2520 fns = ovl_cons (OVL_CURRENT (ovl), fns);
2524 if (fns == NULL_TREE)
2526 error ("no member function %qD declared in %qT", name, ctype);
2527 return error_mark_node;
2530 TREE_OPERAND (declarator, 0) = fns;
2533 /* Figure out what exactly is being specialized at this point.
2534 Note that for an explicit instantiation, even one for a
2535 member function, we cannot tell apriori whether the
2536 instantiation is for a member template, or just a member
2537 function of a template class. Even if a member template is
2538 being instantiated, the member template arguments may be
2539 elided if they can be deduced from the rest of the
2541 tmpl = determine_specialization (declarator, decl,
2543 member_specialization,
2547 if (!tmpl || tmpl == error_mark_node)
2548 /* We couldn't figure out what this declaration was
2550 return error_mark_node;
2553 tree gen_tmpl = most_general_template (tmpl);
2555 if (explicit_instantiation)
2557 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2558 is done by do_decl_instantiation later. */
2560 int arg_depth = TMPL_ARGS_DEPTH (targs);
2561 int parm_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
2563 if (arg_depth > parm_depth)
2565 /* If TMPL is not the most general template (for
2566 example, if TMPL is a friend template that is
2567 injected into namespace scope), then there will
2568 be too many levels of TARGS. Remove some of them
2573 new_targs = make_tree_vec (parm_depth);
2574 for (i = arg_depth - parm_depth; i < arg_depth; ++i)
2575 TREE_VEC_ELT (new_targs, i - (arg_depth - parm_depth))
2576 = TREE_VEC_ELT (targs, i);
2580 return instantiate_template (tmpl, targs, tf_error);
2583 /* If we thought that the DECL was a member function, but it
2584 turns out to be specializing a static member function,
2585 make DECL a static member function as well. */
2586 if (DECL_STATIC_FUNCTION_P (tmpl)
2587 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2588 revert_static_member_fn (decl);
2590 /* If this is a specialization of a member template of a
2591 template class, we want to return the TEMPLATE_DECL, not
2592 the specialization of it. */
2593 if (tsk == tsk_template)
2595 tree result = DECL_TEMPLATE_RESULT (tmpl);
2596 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
2597 DECL_INITIAL (result) = NULL_TREE;
2601 DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl);
2602 DECL_SOURCE_LOCATION (result)
2603 = DECL_SOURCE_LOCATION (decl);
2604 /* We want to use the argument list specified in the
2605 definition, not in the original declaration. */
2606 DECL_ARGUMENTS (result) = DECL_ARGUMENTS (decl);
2607 for (parm = DECL_ARGUMENTS (result); parm;
2608 parm = DECL_CHAIN (parm))
2609 DECL_CONTEXT (parm) = result;
2611 return register_specialization (tmpl, gen_tmpl, targs,
2615 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2616 DECL_TEMPLATE_INFO (decl) = build_template_info (tmpl, targs);
2618 /* Inherit default function arguments from the template
2619 DECL is specializing. */
2620 copy_default_args_to_explicit_spec (decl);
2622 /* This specialization has the same protection as the
2623 template it specializes. */
2624 TREE_PRIVATE (decl) = TREE_PRIVATE (gen_tmpl);
2625 TREE_PROTECTED (decl) = TREE_PROTECTED (gen_tmpl);
2627 /* 7.1.1-1 [dcl.stc]
2629 A storage-class-specifier shall not be specified in an
2630 explicit specialization...
2632 The parser rejects these, so unless action is taken here,
2633 explicit function specializations will always appear with
2636 The action recommended by the C++ CWG in response to C++
2637 defect report 605 is to make the storage class and linkage
2638 of the explicit specialization match the templated function:
2640 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2642 if (tsk == tsk_expl_spec && DECL_FUNCTION_TEMPLATE_P (gen_tmpl))
2644 tree tmpl_func = DECL_TEMPLATE_RESULT (gen_tmpl);
2645 gcc_assert (TREE_CODE (tmpl_func) == FUNCTION_DECL);
2647 /* This specialization has the same linkage and visibility as
2648 the function template it specializes. */
2649 TREE_PUBLIC (decl) = TREE_PUBLIC (tmpl_func);
2650 if (! TREE_PUBLIC (decl))
2652 DECL_INTERFACE_KNOWN (decl) = 1;
2653 DECL_NOT_REALLY_EXTERN (decl) = 1;
2655 DECL_THIS_STATIC (decl) = DECL_THIS_STATIC (tmpl_func);
2656 if (DECL_VISIBILITY_SPECIFIED (tmpl_func))
2658 DECL_VISIBILITY_SPECIFIED (decl) = 1;
2659 DECL_VISIBILITY (decl) = DECL_VISIBILITY (tmpl_func);
2663 /* If DECL is a friend declaration, declared using an
2664 unqualified name, the namespace associated with DECL may
2665 have been set incorrectly. For example, in:
2667 template <typename T> void f(T);
2669 struct S { friend void f<int>(int); }
2672 we will have set the DECL_CONTEXT for the friend
2673 declaration to N, rather than to the global namespace. */
2674 if (DECL_NAMESPACE_SCOPE_P (decl))
2675 DECL_CONTEXT (decl) = DECL_CONTEXT (tmpl);
2677 if (is_friend && !have_def)
2678 /* This is not really a declaration of a specialization.
2679 It's just the name of an instantiation. But, it's not
2680 a request for an instantiation, either. */
2681 SET_DECL_IMPLICIT_INSTANTIATION (decl);
2682 else if (DECL_CONSTRUCTOR_P (decl) || DECL_DESTRUCTOR_P (decl))
2683 /* This is indeed a specialization. In case of constructors
2684 and destructors, we need in-charge and not-in-charge
2685 versions in V3 ABI. */
2686 clone_function_decl (decl, /*update_method_vec_p=*/0);
2688 /* Register this specialization so that we can find it
2690 decl = register_specialization (decl, gen_tmpl, targs, is_friend, 0);
2697 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2698 parameters. These are represented in the same format used for
2699 DECL_TEMPLATE_PARMS. */
2702 comp_template_parms (const_tree parms1, const_tree parms2)
2707 if (parms1 == parms2)
2710 for (p1 = parms1, p2 = parms2;
2711 p1 != NULL_TREE && p2 != NULL_TREE;
2712 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2))
2714 tree t1 = TREE_VALUE (p1);
2715 tree t2 = TREE_VALUE (p2);
2718 gcc_assert (TREE_CODE (t1) == TREE_VEC);
2719 gcc_assert (TREE_CODE (t2) == TREE_VEC);
2721 if (TREE_VEC_LENGTH (t1) != TREE_VEC_LENGTH (t2))
2724 for (i = 0; i < TREE_VEC_LENGTH (t2); ++i)
2726 tree parm1 = TREE_VALUE (TREE_VEC_ELT (t1, i));
2727 tree parm2 = TREE_VALUE (TREE_VEC_ELT (t2, i));
2729 /* If either of the template parameters are invalid, assume
2730 they match for the sake of error recovery. */
2731 if (parm1 == error_mark_node || parm2 == error_mark_node)
2734 if (TREE_CODE (parm1) != TREE_CODE (parm2))
2737 if (TREE_CODE (parm1) == TEMPLATE_TYPE_PARM
2738 && (TEMPLATE_TYPE_PARAMETER_PACK (parm1)
2739 == TEMPLATE_TYPE_PARAMETER_PACK (parm2)))
2741 else if (!same_type_p (TREE_TYPE (parm1), TREE_TYPE (parm2)))
2746 if ((p1 != NULL_TREE) != (p2 != NULL_TREE))
2747 /* One set of parameters has more parameters lists than the
2754 /* Determine whether PARM is a parameter pack. */
2757 template_parameter_pack_p (const_tree parm)
2759 /* Determine if we have a non-type template parameter pack. */
2760 if (TREE_CODE (parm) == PARM_DECL)
2761 return (DECL_TEMPLATE_PARM_P (parm)
2762 && TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)));
2763 if (TREE_CODE (parm) == TEMPLATE_PARM_INDEX)
2764 return TEMPLATE_PARM_PARAMETER_PACK (parm);
2766 /* If this is a list of template parameters, we could get a
2767 TYPE_DECL or a TEMPLATE_DECL. */
2768 if (TREE_CODE (parm) == TYPE_DECL || TREE_CODE (parm) == TEMPLATE_DECL)
2769 parm = TREE_TYPE (parm);
2771 /* Otherwise it must be a type template parameter. */
2772 return ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
2773 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM)
2774 && TEMPLATE_TYPE_PARAMETER_PACK (parm));
2777 /* Determine if T is a function parameter pack. */
2780 function_parameter_pack_p (const_tree t)
2782 if (t && TREE_CODE (t) == PARM_DECL)
2783 return FUNCTION_PARAMETER_PACK_P (t);
2787 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2788 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2791 get_function_template_decl (const_tree primary_func_tmpl_inst)
2793 if (! primary_func_tmpl_inst
2794 || TREE_CODE (primary_func_tmpl_inst) != FUNCTION_DECL
2795 || ! primary_template_instantiation_p (primary_func_tmpl_inst))
2798 return DECL_TEMPLATE_RESULT (DECL_TI_TEMPLATE (primary_func_tmpl_inst));
2801 /* Return true iff the function parameter PARAM_DECL was expanded
2802 from the function parameter pack PACK. */
2805 function_parameter_expanded_from_pack_p (tree param_decl, tree pack)
2807 if (DECL_ARTIFICIAL (param_decl)
2808 || !function_parameter_pack_p (pack))
2811 /* The parameter pack and its pack arguments have the same
2813 return DECL_PARM_INDEX (pack) == DECL_PARM_INDEX (param_decl);
2816 /* Determine whether ARGS describes a variadic template args list,
2817 i.e., one that is terminated by a template argument pack. */
2820 template_args_variadic_p (tree args)
2825 if (args == NULL_TREE)
2828 args = INNERMOST_TEMPLATE_ARGS (args);
2829 nargs = TREE_VEC_LENGTH (args);
2834 last_parm = TREE_VEC_ELT (args, nargs - 1);
2836 return ARGUMENT_PACK_P (last_parm);
2839 /* Generate a new name for the parameter pack name NAME (an
2840 IDENTIFIER_NODE) that incorporates its */
2843 make_ith_pack_parameter_name (tree name, int i)
2845 /* Munge the name to include the parameter index. */
2846 #define NUMBUF_LEN 128
2847 char numbuf[NUMBUF_LEN];
2851 snprintf (numbuf, NUMBUF_LEN, "%i", i);
2852 newname_len = IDENTIFIER_LENGTH (name)
2853 + strlen (numbuf) + 2;
2854 newname = (char*)alloca (newname_len);
2855 snprintf (newname, newname_len,
2856 "%s#%i", IDENTIFIER_POINTER (name), i);
2857 return get_identifier (newname);
2860 /* Return true if T is a primary function, class or alias template
2864 primary_template_instantiation_p (const_tree t)
2869 if (TREE_CODE (t) == FUNCTION_DECL)
2870 return DECL_LANG_SPECIFIC (t)
2871 && DECL_TEMPLATE_INSTANTIATION (t)
2872 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (t));
2873 else if (CLASS_TYPE_P (t) && !TYPE_DECL_ALIAS_P (TYPE_NAME (t)))
2874 return CLASSTYPE_TEMPLATE_INSTANTIATION (t)
2875 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (t));
2877 && TYPE_TEMPLATE_INFO (t)
2878 && PRIMARY_TEMPLATE_P (TYPE_TI_TEMPLATE (t))
2879 && DECL_TEMPLATE_INSTANTIATION (TYPE_NAME (t)))
2884 /* Return true if PARM is a template template parameter. */
2887 template_template_parameter_p (const_tree parm)
2889 return DECL_TEMPLATE_TEMPLATE_PARM_P (parm);
2892 /* Return the template parameters of T if T is a
2893 primary template instantiation, NULL otherwise. */
2896 get_primary_template_innermost_parameters (const_tree t)
2898 tree parms = NULL, template_info = NULL;
2900 if ((template_info = get_template_info (t))
2901 && primary_template_instantiation_p (t))
2902 parms = INNERMOST_TEMPLATE_PARMS
2903 (DECL_TEMPLATE_PARMS (TI_TEMPLATE (template_info)));
2908 /* Return the template parameters of the LEVELth level from the full list
2909 of template parameters PARMS. */
2912 get_template_parms_at_level (tree parms, int level)
2916 || TREE_CODE (parms) != TREE_LIST
2917 || level > TMPL_PARMS_DEPTH (parms))
2920 for (p = parms; p; p = TREE_CHAIN (p))
2921 if (TMPL_PARMS_DEPTH (p) == level)
2927 /* Returns the template arguments of T if T is a template instantiation,
2931 get_template_innermost_arguments (const_tree t)
2933 tree args = NULL, template_info = NULL;
2935 if ((template_info = get_template_info (t))
2936 && TI_ARGS (template_info))
2937 args = INNERMOST_TEMPLATE_ARGS (TI_ARGS (template_info));
2942 /* Return the argument pack elements of T if T is a template argument pack,
2946 get_template_argument_pack_elems (const_tree t)
2948 if (TREE_CODE (t) != TYPE_ARGUMENT_PACK
2949 && TREE_CODE (t) != NONTYPE_ARGUMENT_PACK)
2952 return ARGUMENT_PACK_ARGS (t);
2955 /* Structure used to track the progress of find_parameter_packs_r. */
2956 struct find_parameter_pack_data
2958 /* TREE_LIST that will contain all of the parameter packs found by
2960 tree* parameter_packs;
2962 /* Set of AST nodes that have been visited by the traversal. */
2963 struct pointer_set_t *visited;
2966 /* Identifies all of the argument packs that occur in a template
2967 argument and appends them to the TREE_LIST inside DATA, which is a
2968 find_parameter_pack_data structure. This is a subroutine of
2969 make_pack_expansion and uses_parameter_packs. */
2971 find_parameter_packs_r (tree *tp, int *walk_subtrees, void* data)
2974 struct find_parameter_pack_data* ppd =
2975 (struct find_parameter_pack_data*)data;
2976 bool parameter_pack_p = false;
2978 /* Identify whether this is a parameter pack or not. */
2979 switch (TREE_CODE (t))
2981 case TEMPLATE_PARM_INDEX:
2982 if (TEMPLATE_PARM_PARAMETER_PACK (t))
2983 parameter_pack_p = true;
2986 case TEMPLATE_TYPE_PARM:
2987 t = TYPE_MAIN_VARIANT (t);
2988 case TEMPLATE_TEMPLATE_PARM:
2989 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
2990 parameter_pack_p = true;
2994 if (FUNCTION_PARAMETER_PACK_P (t))
2996 /* We don't want to walk into the type of a PARM_DECL,
2997 because we don't want to see the type parameter pack. */
2999 parameter_pack_p = true;
3004 parameter_pack_p = true;
3007 /* Not a parameter pack. */
3011 if (parameter_pack_p)
3013 /* Add this parameter pack to the list. */
3014 *ppd->parameter_packs = tree_cons (NULL_TREE, t, *ppd->parameter_packs);
3018 cp_walk_tree (&TYPE_CONTEXT (t),
3019 &find_parameter_packs_r, ppd, ppd->visited);
3021 /* This switch statement will return immediately if we don't find a
3023 switch (TREE_CODE (t))
3025 case TEMPLATE_PARM_INDEX:
3028 case BOUND_TEMPLATE_TEMPLATE_PARM:
3029 /* Check the template itself. */
3030 cp_walk_tree (&TREE_TYPE (TYPE_TI_TEMPLATE (t)),
3031 &find_parameter_packs_r, ppd, ppd->visited);
3032 /* Check the template arguments. */
3033 cp_walk_tree (&TYPE_TI_ARGS (t), &find_parameter_packs_r, ppd,
3038 case TEMPLATE_TYPE_PARM:
3039 case TEMPLATE_TEMPLATE_PARM:
3046 if (TYPE_PTRMEMFUNC_P (t))
3052 if (TYPE_TEMPLATE_INFO (t))
3053 cp_walk_tree (&TI_ARGS (TYPE_TEMPLATE_INFO (t)),
3054 &find_parameter_packs_r, ppd, ppd->visited);
3061 cp_walk_tree (&TREE_TYPE (t),
3062 &find_parameter_packs_r, ppd, ppd->visited);
3066 cp_walk_tree (&TYPENAME_TYPE_FULLNAME (t), &find_parameter_packs_r,
3071 case TYPE_PACK_EXPANSION:
3072 case EXPR_PACK_EXPANSION:
3077 cp_walk_tree (&TYPE_MAX_VALUE (t), &find_parameter_packs_r,
3082 case IDENTIFIER_NODE:
3083 cp_walk_tree (&TREE_TYPE (t), &find_parameter_packs_r, ppd,
3095 /* Determines if the expression or type T uses any parameter packs. */
3097 uses_parameter_packs (tree t)
3099 tree parameter_packs = NULL_TREE;
3100 struct find_parameter_pack_data ppd;
3101 ppd.parameter_packs = ¶meter_packs;
3102 ppd.visited = pointer_set_create ();
3103 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
3104 pointer_set_destroy (ppd.visited);
3105 return parameter_packs != NULL_TREE;
3108 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3109 representation a base-class initializer into a parameter pack
3110 expansion. If all goes well, the resulting node will be an
3111 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3114 make_pack_expansion (tree arg)
3117 tree parameter_packs = NULL_TREE;
3118 bool for_types = false;
3119 struct find_parameter_pack_data ppd;
3121 if (!arg || arg == error_mark_node)
3124 if (TREE_CODE (arg) == TREE_LIST)
3126 /* The only time we will see a TREE_LIST here is for a base
3127 class initializer. In this case, the TREE_PURPOSE will be a
3128 _TYPE node (representing the base class expansion we're
3129 initializing) and the TREE_VALUE will be a TREE_LIST
3130 containing the initialization arguments.
3132 The resulting expansion looks somewhat different from most
3133 expansions. Rather than returning just one _EXPANSION, we
3134 return a TREE_LIST whose TREE_PURPOSE is a
3135 TYPE_PACK_EXPANSION containing the bases that will be
3136 initialized. The TREE_VALUE will be identical to the
3137 original TREE_VALUE, which is a list of arguments that will
3138 be passed to each base. We do not introduce any new pack
3139 expansion nodes into the TREE_VALUE (although it is possible
3140 that some already exist), because the TREE_PURPOSE and
3141 TREE_VALUE all need to be expanded together with the same
3142 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3143 resulting TREE_PURPOSE will mention the parameter packs in
3144 both the bases and the arguments to the bases. */
3147 tree parameter_packs = NULL_TREE;
3149 /* Determine which parameter packs will be used by the base
3151 ppd.visited = pointer_set_create ();
3152 ppd.parameter_packs = ¶meter_packs;
3153 cp_walk_tree (&TREE_PURPOSE (arg), &find_parameter_packs_r,
3156 if (parameter_packs == NULL_TREE)
3158 error ("base initializer expansion %<%T%> contains no parameter packs", arg);
3159 pointer_set_destroy (ppd.visited);
3160 return error_mark_node;
3163 if (TREE_VALUE (arg) != void_type_node)
3165 /* Collect the sets of parameter packs used in each of the
3166 initialization arguments. */
3167 for (value = TREE_VALUE (arg); value; value = TREE_CHAIN (value))
3169 /* Determine which parameter packs will be expanded in this
3171 cp_walk_tree (&TREE_VALUE (value), &find_parameter_packs_r,
3176 pointer_set_destroy (ppd.visited);
3178 /* Create the pack expansion type for the base type. */
3179 purpose = cxx_make_type (TYPE_PACK_EXPANSION);
3180 SET_PACK_EXPANSION_PATTERN (purpose, TREE_PURPOSE (arg));
3181 PACK_EXPANSION_PARAMETER_PACKS (purpose) = parameter_packs;
3183 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3184 they will rarely be compared to anything. */
3185 SET_TYPE_STRUCTURAL_EQUALITY (purpose);
3187 return tree_cons (purpose, TREE_VALUE (arg), NULL_TREE);
3190 if (TYPE_P (arg) || TREE_CODE (arg) == TEMPLATE_DECL)
3193 /* Build the PACK_EXPANSION_* node. */
3195 ? cxx_make_type (TYPE_PACK_EXPANSION)
3196 : make_node (EXPR_PACK_EXPANSION);
3197 SET_PACK_EXPANSION_PATTERN (result, arg);
3198 if (TREE_CODE (result) == EXPR_PACK_EXPANSION)
3200 /* Propagate type and const-expression information. */
3201 TREE_TYPE (result) = TREE_TYPE (arg);
3202 TREE_CONSTANT (result) = TREE_CONSTANT (arg);
3205 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3206 they will rarely be compared to anything. */
3207 SET_TYPE_STRUCTURAL_EQUALITY (result);
3209 /* Determine which parameter packs will be expanded. */
3210 ppd.parameter_packs = ¶meter_packs;
3211 ppd.visited = pointer_set_create ();
3212 cp_walk_tree (&arg, &find_parameter_packs_r, &ppd, ppd.visited);
3213 pointer_set_destroy (ppd.visited);
3215 /* Make sure we found some parameter packs. */
3216 if (parameter_packs == NULL_TREE)
3219 error ("expansion pattern %<%T%> contains no argument packs", arg);
3221 error ("expansion pattern %<%E%> contains no argument packs", arg);
3222 return error_mark_node;
3224 PACK_EXPANSION_PARAMETER_PACKS (result) = parameter_packs;
3229 /* Checks T for any "bare" parameter packs, which have not yet been
3230 expanded, and issues an error if any are found. This operation can
3231 only be done on full expressions or types (e.g., an expression
3232 statement, "if" condition, etc.), because we could have expressions like:
3234 foo(f(g(h(args)))...)
3236 where "args" is a parameter pack. check_for_bare_parameter_packs
3237 should not be called for the subexpressions args, h(args),
3238 g(h(args)), or f(g(h(args))), because we would produce erroneous
3241 Returns TRUE and emits an error if there were bare parameter packs,
3242 returns FALSE otherwise. */
3244 check_for_bare_parameter_packs (tree t)
3246 tree parameter_packs = NULL_TREE;
3247 struct find_parameter_pack_data ppd;
3249 if (!processing_template_decl || !t || t == error_mark_node)
3252 if (TREE_CODE (t) == TYPE_DECL)
3255 ppd.parameter_packs = ¶meter_packs;
3256 ppd.visited = pointer_set_create ();
3257 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
3258 pointer_set_destroy (ppd.visited);
3260 if (parameter_packs)
3262 error ("parameter packs not expanded with %<...%>:");
3263 while (parameter_packs)
3265 tree pack = TREE_VALUE (parameter_packs);
3266 tree name = NULL_TREE;
3268 if (TREE_CODE (pack) == TEMPLATE_TYPE_PARM
3269 || TREE_CODE (pack) == TEMPLATE_TEMPLATE_PARM)
3270 name = TYPE_NAME (pack);
3271 else if (TREE_CODE (pack) == TEMPLATE_PARM_INDEX)
3272 name = DECL_NAME (TEMPLATE_PARM_DECL (pack));
3274 name = DECL_NAME (pack);
3277 inform (input_location, " %qD", name);
3279 inform (input_location, " <anonymous>");
3281 parameter_packs = TREE_CHAIN (parameter_packs);
3290 /* Expand any parameter packs that occur in the template arguments in
3293 expand_template_argument_pack (tree args)
3295 tree result_args = NULL_TREE;
3296 int in_arg, out_arg = 0, nargs = args ? TREE_VEC_LENGTH (args) : 0;
3297 int num_result_args = -1;
3298 int non_default_args_count = -1;
3300 /* First, determine if we need to expand anything, and the number of
3301 slots we'll need. */
3302 for (in_arg = 0; in_arg < nargs; ++in_arg)
3304 tree arg = TREE_VEC_ELT (args, in_arg);
3305 if (arg == NULL_TREE)
3307 if (ARGUMENT_PACK_P (arg))
3309 int num_packed = TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg));
3310 if (num_result_args < 0)
3311 num_result_args = in_arg + num_packed;
3313 num_result_args += num_packed;
3317 if (num_result_args >= 0)
3322 /* If no expansion is necessary, we're done. */
3323 if (num_result_args < 0)
3326 /* Expand arguments. */
3327 result_args = make_tree_vec (num_result_args);
3328 if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (args))
3329 non_default_args_count =
3330 GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (args);
3331 for (in_arg = 0; in_arg < nargs; ++in_arg)
3333 tree arg = TREE_VEC_ELT (args, in_arg);
3334 if (ARGUMENT_PACK_P (arg))
3336 tree packed = ARGUMENT_PACK_ARGS (arg);
3337 int i, num_packed = TREE_VEC_LENGTH (packed);
3338 for (i = 0; i < num_packed; ++i, ++out_arg)
3339 TREE_VEC_ELT (result_args, out_arg) = TREE_VEC_ELT(packed, i);
3340 if (non_default_args_count > 0)
3341 non_default_args_count += num_packed;
3345 TREE_VEC_ELT (result_args, out_arg) = arg;
3349 if (non_default_args_count >= 0)
3350 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (result_args, non_default_args_count);
3354 /* Checks if DECL shadows a template parameter.
3356 [temp.local]: A template-parameter shall not be redeclared within its
3357 scope (including nested scopes).
3359 Emits an error and returns TRUE if the DECL shadows a parameter,
3360 returns FALSE otherwise. */
3363 check_template_shadow (tree decl)
3367 /* If we're not in a template, we can't possibly shadow a template
3369 if (!current_template_parms)
3372 /* Figure out what we're shadowing. */
3373 if (TREE_CODE (decl) == OVERLOAD)
3374 decl = OVL_CURRENT (decl);
3375 olddecl = innermost_non_namespace_value (DECL_NAME (decl));
3377 /* If there's no previous binding for this name, we're not shadowing
3378 anything, let alone a template parameter. */
3382 /* If we're not shadowing a template parameter, we're done. Note
3383 that OLDDECL might be an OVERLOAD (or perhaps even an
3384 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3386 if (!DECL_P (olddecl) || !DECL_TEMPLATE_PARM_P (olddecl))
3389 /* We check for decl != olddecl to avoid bogus errors for using a
3390 name inside a class. We check TPFI to avoid duplicate errors for
3391 inline member templates. */
3393 || TEMPLATE_PARMS_FOR_INLINE (current_template_parms))
3396 error ("declaration of %q+#D", decl);
3397 error (" shadows template parm %q+#D", olddecl);
3401 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3402 ORIG_LEVEL, DECL, and TYPE. NUM_SIBLINGS is the total number of
3403 template parameters. */
3406 build_template_parm_index (int index,
3413 tree t = make_node (TEMPLATE_PARM_INDEX);
3414 TEMPLATE_PARM_IDX (t) = index;
3415 TEMPLATE_PARM_LEVEL (t) = level;
3416 TEMPLATE_PARM_ORIG_LEVEL (t) = orig_level;
3417 TEMPLATE_PARM_NUM_SIBLINGS (t) = num_siblings;
3418 TEMPLATE_PARM_DECL (t) = decl;
3419 TREE_TYPE (t) = type;
3420 TREE_CONSTANT (t) = TREE_CONSTANT (decl);
3421 TREE_READONLY (t) = TREE_READONLY (decl);
3426 /* Find the canonical type parameter for the given template type
3427 parameter. Returns the canonical type parameter, which may be TYPE
3428 if no such parameter existed. */
3431 canonical_type_parameter (tree type)
3434 int idx = TEMPLATE_TYPE_IDX (type);
3435 if (!canonical_template_parms)
3436 canonical_template_parms = VEC_alloc (tree, gc, idx+1);
3438 while (VEC_length (tree, canonical_template_parms) <= (unsigned)idx)
3439 VEC_safe_push (tree, gc, canonical_template_parms, NULL_TREE);
3441 list = VEC_index (tree, canonical_template_parms, idx);
3442 while (list && !comptypes (type, TREE_VALUE (list), COMPARE_STRUCTURAL))
3443 list = TREE_CHAIN (list);
3446 return TREE_VALUE (list);
3449 VEC_replace(tree, canonical_template_parms, idx,
3450 tree_cons (NULL_TREE, type,
3451 VEC_index (tree, canonical_template_parms, idx)));
3456 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3457 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3458 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3459 new one is created. */
3462 reduce_template_parm_level (tree index, tree type, int levels, tree args,
3463 tsubst_flags_t complain)
3465 if (TEMPLATE_PARM_DESCENDANTS (index) == NULL_TREE
3466 || (TEMPLATE_PARM_LEVEL (TEMPLATE_PARM_DESCENDANTS (index))
3467 != TEMPLATE_PARM_LEVEL (index) - levels)
3468 || !same_type_p (type, TREE_TYPE (TEMPLATE_PARM_DESCENDANTS (index))))
3470 tree orig_decl = TEMPLATE_PARM_DECL (index);
3473 decl = build_decl (DECL_SOURCE_LOCATION (orig_decl),
3474 TREE_CODE (orig_decl), DECL_NAME (orig_decl), type);
3475 TREE_CONSTANT (decl) = TREE_CONSTANT (orig_decl);
3476 TREE_READONLY (decl) = TREE_READONLY (orig_decl);
3477 DECL_ARTIFICIAL (decl) = 1;
3478 SET_DECL_TEMPLATE_PARM_P (decl);
3480 t = build_template_parm_index (TEMPLATE_PARM_IDX (index),
3481 TEMPLATE_PARM_LEVEL (index) - levels,
3482 TEMPLATE_PARM_ORIG_LEVEL (index),
3483 TEMPLATE_PARM_NUM_SIBLINGS (index),
3485 TEMPLATE_PARM_DESCENDANTS (index) = t;
3486 TEMPLATE_PARM_PARAMETER_PACK (t)
3487 = TEMPLATE_PARM_PARAMETER_PACK (index);
3489 /* Template template parameters need this. */
3490 if (TREE_CODE (decl) == TEMPLATE_DECL)
3491 DECL_TEMPLATE_PARMS (decl) = tsubst_template_parms
3492 (DECL_TEMPLATE_PARMS (TEMPLATE_PARM_DECL (index)),
3496 return TEMPLATE_PARM_DESCENDANTS (index);
3499 /* Process information from new template parameter PARM and append it
3500 to the LIST being built. This new parameter is a non-type
3501 parameter iff IS_NON_TYPE is true. This new parameter is a
3502 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3503 is in PARM_LOC. NUM_TEMPLATE_PARMS is the size of the template
3504 parameter list PARM belongs to. This is used used to create a
3505 proper canonical type for the type of PARM that is to be created,
3506 iff PARM is a type. If the size is not known, this parameter shall
3510 process_template_parm (tree list, location_t parm_loc, tree parm,
3511 bool is_non_type, bool is_parameter_pack,
3512 unsigned num_template_parms)
3519 gcc_assert (TREE_CODE (parm) == TREE_LIST);
3520 defval = TREE_PURPOSE (parm);
3524 tree p = tree_last (list);
3526 if (p && TREE_VALUE (p) != error_mark_node)
3529 if (TREE_CODE (p) == TYPE_DECL || TREE_CODE (p) == TEMPLATE_DECL)
3530 idx = TEMPLATE_TYPE_IDX (TREE_TYPE (p));
3532 idx = TEMPLATE_PARM_IDX (DECL_INITIAL (p));
3542 parm = TREE_VALUE (parm);
3544 SET_DECL_TEMPLATE_PARM_P (parm);
3546 if (TREE_TYPE (parm) == error_mark_node)
3548 err_parm_list = build_tree_list (defval, parm);
3549 TREE_VALUE (err_parm_list) = error_mark_node;
3550 return chainon (list, err_parm_list);
3556 The top-level cv-qualifiers on the template-parameter are
3557 ignored when determining its type. */
3558 TREE_TYPE (parm) = TYPE_MAIN_VARIANT (TREE_TYPE (parm));
3559 if (invalid_nontype_parm_type_p (TREE_TYPE (parm), 1))
3561 err_parm_list = build_tree_list (defval, parm);
3562 TREE_VALUE (err_parm_list) = error_mark_node;
3563 return chainon (list, err_parm_list);
3566 if (uses_parameter_packs (TREE_TYPE (parm)) && !is_parameter_pack)
3568 /* This template parameter is not a parameter pack, but it
3569 should be. Complain about "bare" parameter packs. */
3570 check_for_bare_parameter_packs (TREE_TYPE (parm));
3572 /* Recover by calling this a parameter pack. */
3573 is_parameter_pack = true;
3577 /* A template parameter is not modifiable. */
3578 TREE_CONSTANT (parm) = 1;
3579 TREE_READONLY (parm) = 1;
3580 decl = build_decl (parm_loc,
3581 CONST_DECL, DECL_NAME (parm), TREE_TYPE (parm));
3582 TREE_CONSTANT (decl) = 1;
3583 TREE_READONLY (decl) = 1;
3584 DECL_INITIAL (parm) = DECL_INITIAL (decl)
3585 = build_template_parm_index (idx, processing_template_decl,
3586 processing_template_decl,
3588 decl, TREE_TYPE (parm));
3590 TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))
3591 = is_parameter_pack;
3596 parm = TREE_VALUE (TREE_VALUE (parm));
3598 if (parm && TREE_CODE (parm) == TEMPLATE_DECL)
3600 t = cxx_make_type (TEMPLATE_TEMPLATE_PARM);
3601 /* This is for distinguishing between real templates and template
3602 template parameters */
3603 TREE_TYPE (parm) = t;
3604 TREE_TYPE (DECL_TEMPLATE_RESULT (parm)) = t;
3609 t = cxx_make_type (TEMPLATE_TYPE_PARM);
3610 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3611 decl = build_decl (parm_loc,
3612 TYPE_DECL, parm, t);
3615 TYPE_NAME (t) = decl;
3616 TYPE_STUB_DECL (t) = decl;
3618 TEMPLATE_TYPE_PARM_INDEX (t)
3619 = build_template_parm_index (idx, processing_template_decl,
3620 processing_template_decl,
3622 decl, TREE_TYPE (parm));
3623 TEMPLATE_TYPE_PARAMETER_PACK (t) = is_parameter_pack;
3624 TYPE_CANONICAL (t) = canonical_type_parameter (t);
3626 DECL_ARTIFICIAL (decl) = 1;
3627 SET_DECL_TEMPLATE_PARM_P (decl);
3629 parm = build_tree_list (defval, parm);
3630 return chainon (list, parm);
3633 /* The end of a template parameter list has been reached. Process the
3634 tree list into a parameter vector, converting each parameter into a more
3635 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3639 end_template_parm_list (tree parms)
3643 tree saved_parmlist = make_tree_vec (list_length (parms));
3645 current_template_parms
3646 = tree_cons (size_int (processing_template_decl),
3647 saved_parmlist, current_template_parms);
3649 for (parm = parms, nparms = 0; parm; parm = next, nparms++)
3651 next = TREE_CHAIN (parm);
3652 TREE_VEC_ELT (saved_parmlist, nparms) = parm;
3653 TREE_CHAIN (parm) = NULL_TREE;
3656 --processing_template_parmlist;
3658 return saved_parmlist;
3661 /* Create a new type almost identical to TYPE but which has the
3662 following differences:
3664 1/ T has a new TEMPLATE_PARM_INDEX that carries the new number of
3665 template sibling parameters of T.
3667 2/ T has a new canonical type that matches the new number
3670 3/ From now on, T is going to be what lookups referring to the
3671 name of TYPE will return. No lookup should return TYPE anymore.
3673 NUM_PARMS is the new number of sibling parms TYPE belongs to.
3675 This is a subroutine of fixup_template_parms. */
3678 fixup_template_type_parm_type (tree type, int num_parms)
3680 tree orig_idx = TEMPLATE_TYPE_PARM_INDEX (type), idx;
3682 /* This is the decl which name is inserted into the symbol table for
3683 the template parm type. So whenever we lookup the type name, this
3684 is the DECL we get. */
3687 /* Do not fix up the type twice. */
3688 if (orig_idx && TEMPLATE_PARM_NUM_SIBLINGS (orig_idx) != 0)
3691 t = copy_type (type);
3692 decl = TYPE_NAME (t);
3694 TYPE_MAIN_VARIANT (t) = t;
3695 TYPE_NEXT_VARIANT (t)= NULL_TREE;
3696 TYPE_POINTER_TO (t) = 0;
3697 TYPE_REFERENCE_TO (t) = 0;
3699 idx = build_template_parm_index (TEMPLATE_PARM_IDX (orig_idx),
3700 TEMPLATE_PARM_LEVEL (orig_idx),
3701 TEMPLATE_PARM_ORIG_LEVEL (orig_idx),
3704 TEMPLATE_PARM_DESCENDANTS (idx) = TEMPLATE_PARM_DESCENDANTS (orig_idx);
3705 TEMPLATE_PARM_PARAMETER_PACK (idx) = TEMPLATE_PARM_PARAMETER_PACK (orig_idx);
3706 TEMPLATE_TYPE_PARM_INDEX (t) = idx;
3708 TYPE_STUB_DECL (t) = decl;
3709 TEMPLATE_TYPE_DECL (t) = decl;
3710 if (TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM)
3711 TREE_TYPE (DECL_TEMPLATE_RESULT (decl)) = t;
3713 /* Update the type associated to the type name stored in the symbol
3714 table. Now, whenever the type name is looked up, the resulting
3715 type is properly fixed up. */
3716 TREE_TYPE (decl) = t;
3718 TYPE_CANONICAL (t) = canonical_type_parameter (t);
3723 /* Create and return a new TEMPLATE_PARM_INDEX that is almost
3724 identical to I, but that is fixed up as to:
3726 1/ carry the number of sibling parms (NUM_PARMS) of the template
3727 parm represented by I.
3729 2/ replace all references to template parm types declared before I
3730 (in the same template parm list as I) by references to template
3731 parm types contained in ARGS. ARGS should contain the list of
3732 template parms that have been fixed up so far, in a form suitable
3733 to be passed to tsubst.
3735 This is a subroutine of fixup_template_parms. */
3738 fixup_template_parm_index (tree i, tree args, int num_parms)
3740 tree index, decl, type;
3743 || TREE_CODE (i) != TEMPLATE_PARM_INDEX
3744 /* Do not fix up the index twice. */
3745 || (TEMPLATE_PARM_NUM_SIBLINGS (i) != 0))
3748 decl = TEMPLATE_PARM_DECL (i);
3749 type = TREE_TYPE (decl);
3751 index = build_template_parm_index (TEMPLATE_PARM_IDX (i),
3752 TEMPLATE_PARM_LEVEL (i),
3753 TEMPLATE_PARM_ORIG_LEVEL (i),
3757 TEMPLATE_PARM_DESCENDANTS (index) = TEMPLATE_PARM_DESCENDANTS (i);
3758 TEMPLATE_PARM_PARAMETER_PACK (index) = TEMPLATE_PARM_PARAMETER_PACK (i);
3760 type = tsubst (type, args, tf_none, NULL_TREE);
3762 TREE_TYPE (decl) = type;
3763 TREE_TYPE (index) = type;
3769 This is a subroutine of fixup_template_parms.
3771 It computes the canonical type of the type of the template
3772 parameter PARM_DESC and update all references to that type so that
3773 they use the newly computed canonical type. No access check is
3774 performed during the fixup. PARM_DESC is a TREE_LIST which
3775 TREE_VALUE is the template parameter and its TREE_PURPOSE is the
3776 default argument of the template parm if any. IDX is the index of
3777 the template parameter, starting at 0. NUM_PARMS is the number of
3778 template parameters in the set PARM_DESC belongs to. ARGLIST is a
3779 TREE_VEC containing the full set of template parameters in a form
3780 suitable to be passed to substs functions as their ARGS
3781 argument. This is what current_template_args returns for a given
3782 template. The innermost vector of args in ARGLIST is the set of
3783 template parms that have been fixed up so far. This function adds
3784 the fixed up parameter into that vector. */
3787 fixup_template_parm (tree parm_desc,
3792 tree parm = TREE_VALUE (parm_desc);
3793 tree fixedup_args = INNERMOST_TEMPLATE_ARGS (arglist);
3795 push_deferring_access_checks (dk_no_check);
3797 if (TREE_CODE (parm) == TYPE_DECL)
3799 /* PARM is a template type parameter. Fix up its type, add
3800 the fixed-up template parm to the vector of fixed-up
3801 template parms so far, and substitute the fixed-up
3802 template parms into the default argument of this
3805 fixup_template_type_parm_type (TREE_TYPE (parm), num_parms);
3806 TREE_TYPE (parm) = t;
3808 TREE_VEC_ELT (fixedup_args, idx) = template_parm_to_arg (parm_desc);
3810 else if (TREE_CODE (parm) == TEMPLATE_DECL)
3812 /* PARM is a template template parameter. This is going to
3814 tree tparms, targs, innermost_args, t;
3817 /* First, fix up the parms of the template template parm
3818 because the parms are involved in defining the new canonical
3819 type of the template template parm. */
3821 /* So we need to substitute the template parm types that have
3822 been fixed up so far into the template parms of this template
3823 template parm. E.g, consider this:
3825 template<class T, template<T u> class TT> class S;
3827 In this case we want to substitute T into the
3828 template parameters of TT.
3830 So let's walk the template parms of PARM here, and
3831 tsubst ARGLIST into into each of the template
3834 /* For this substitution we need to build the full set of
3835 template parameters and use that as arguments for the
3836 tsubsting function. */
3837 tparms = INNERMOST_TEMPLATE_PARMS (DECL_TEMPLATE_PARMS (parm));
3839 /* This will contain the innermost parms of PARM into which
3840 we have substituted so far. */
3841 innermost_args = make_tree_vec (TREE_VEC_LENGTH (tparms));
3842 targs = add_to_template_args (arglist, innermost_args);
3843 for (j = 0; j < TREE_VEC_LENGTH (tparms); ++j)
3847 parameter = TREE_VEC_ELT (tparms, j);
3849 /* INNERMOST_ARGS needs to have at least the same number
3850 of elements as the index PARAMETER, ortherwise
3851 tsubsting into PARAMETER will result in partially
3852 instantiating it, reducing its tempate parm
3853 level. Let's tactically fill INNERMOST_ARGS for that
3855 TREE_VEC_ELT (innermost_args, j) =
3856 template_parm_to_arg (parameter);
3858 fixup_template_parm (parameter, j,
3859 TREE_VEC_LENGTH (tparms),
3863 /* Now fix up the type of the template template parm. */
3865 t = fixup_template_type_parm_type (TREE_TYPE (parm), num_parms);
3866 TREE_TYPE (parm) = t;
3868 TREE_VEC_ELT (fixedup_args, idx) =
3869 template_parm_to_arg (parm_desc);
3871 else if (TREE_CODE (parm) == PARM_DECL)
3873 /* PARM is a non-type template parameter. We need to:
3875 * Fix up its TEMPLATE_PARM_INDEX to make it carry the
3876 proper number of sibling parameters.
3878 * Make lookups of the template parameter return a reference
3879 to the fixed-up index. No lookup should return references
3880 to the former index anymore.
3882 * Substitute the template parms that got fixed up so far
3884 * into the type of PARM. */
3886 tree index = DECL_INITIAL (parm);
3888 /* PUSHED_DECL is the decl added to the symbol table with
3889 the name of the parameter. E,g:
3891 template<class T, T u> //#0
3892 auto my_function(T t) -> decltype(u); //#1
3894 Here, when looking up u at //#1, we get the decl of u
3895 resulting from the declaration in #0. This is what
3896 PUSHED_DECL is. We need to replace the reference to the
3897 old TEMPLATE_PARM_INDEX carried by PUSHED_DECL by the
3898 fixed-up TEMPLATE_PARM_INDEX. */
3899 tree pushed_decl = TEMPLATE_PARM_DECL (index);
3901 /* Let's fix up the TEMPLATE_PARM_INDEX then. Note that we must
3902 fixup the type of PUSHED_DECL as well and luckily
3903 fixup_template_parm_index does it for us too. */
3904 tree fixed_up_index =
3905 fixup_template_parm_index (index, arglist, num_parms);
3907 DECL_INITIAL (pushed_decl) = DECL_INITIAL (parm) = fixed_up_index;
3909 /* Add this fixed up PARM to the template parms we've fixed
3910 up so far and use that to substitute the fixed-up
3911 template parms into the type of PARM. */
3912 TREE_VEC_ELT (fixedup_args, idx) =
3913 template_parm_to_arg (parm_desc);
3914 TREE_TYPE (parm) = tsubst (TREE_TYPE (parm), arglist,
3915 tf_none, NULL_TREE);
3918 TREE_PURPOSE (parm_desc) =
3919 tsubst_template_arg (TREE_PURPOSE (parm_desc),
3920 arglist, tf_none, parm);
3922 pop_deferring_access_checks ();
3925 /* Walk the current template parms and properly compute the canonical
3926 types of the dependent types created during
3927 cp_parser_template_parameter_list. */
3930 fixup_template_parms (void)
3937 parameter_vec = INNERMOST_TEMPLATE_PARMS (current_template_parms);
3938 if (parameter_vec == NULL_TREE)
3941 num_parms = TREE_VEC_LENGTH (parameter_vec);
3943 /* This vector contains the current innermost template parms that
3944 have been fixed up so far. The form of FIXEDUP_ARGS is suitable
3945 to be passed to tsubst* functions as their ARGS argument. */
3946 fixedup_args = make_tree_vec (num_parms);
3948 /* This vector contains the full set of template parms in a form
3949 suitable to be passed to substs functions as their ARGS
3951 arglist = current_template_args ();
3952 arglist = add_outermost_template_args (arglist, fixedup_args);
3954 /* Let's do the proper fixup now. */
3955 for (i = 0; i < num_parms; ++i)
3956 fixup_template_parm (TREE_VEC_ELT (parameter_vec, i),
3957 i, num_parms, arglist);
3960 /* end_template_decl is called after a template declaration is seen. */
3963 end_template_decl (void)
3965 reset_specialization ();
3967 if (! processing_template_decl)
3970 /* This matches the pushlevel in begin_template_parm_list. */
3973 --processing_template_decl;
3974 current_template_parms = TREE_CHAIN (current_template_parms);
3977 /* Takes a TREE_LIST representing a template parameter and convert it
3978 into an argument suitable to be passed to the type substitution
3979 functions. Note that If the TREE_LIST contains an error_mark
3980 node, the returned argument is error_mark_node. */
3983 template_parm_to_arg (tree t)
3987 || TREE_CODE (t) != TREE_LIST)
3990 if (error_operand_p (TREE_VALUE (t)))
3991 return error_mark_node;
3995 if (TREE_CODE (t) == TYPE_DECL
3996 || TREE_CODE (t) == TEMPLATE_DECL)
4000 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
4002 /* Turn this argument into a TYPE_ARGUMENT_PACK
4003 with a single element, which expands T. */
4004 tree vec = make_tree_vec (1);
4005 #ifdef ENABLE_CHECKING
4006 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
4007 (vec, TREE_VEC_LENGTH (vec));
4009 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
4011 t = cxx_make_type (TYPE_ARGUMENT_PACK);
4012 SET_ARGUMENT_PACK_ARGS (t, vec);
4017 t = DECL_INITIAL (t);
4019 if (TEMPLATE_PARM_PARAMETER_PACK (t))
4021 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
4022 with a single element, which expands T. */
4023 tree vec = make_tree_vec (1);
4024 tree type = TREE_TYPE (TEMPLATE_PARM_DECL (t));
4025 #ifdef ENABLE_CHECKING
4026 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
4027 (vec, TREE_VEC_LENGTH (vec));
4029 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
4031 t = make_node (NONTYPE_ARGUMENT_PACK);
4032 SET_ARGUMENT_PACK_ARGS (t, vec);
4033 TREE_TYPE (t) = type;
4039 /* This function returns TRUE if PARM_PACK is a template parameter
4040 pack and if ARG_PACK is what template_parm_to_arg returned when
4041 passed PARM_PACK. */
4044 arg_from_parm_pack_p (tree arg_pack, tree parm_pack)
4046 /* For clarity in the comments below let's use the representation
4047 argument_pack<elements>' to denote an argument pack and its
4050 In the 'if' block below, we want to detect cases where
4051 ARG_PACK is argument_pack<PARM_PACK...>. I.e, we want to
4052 check if ARG_PACK is an argument pack which sole element is
4053 the expansion of PARM_PACK. That argument pack is typically
4054 created by template_parm_to_arg when passed a parameter
4058 && TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack)) == 1
4059 && PACK_EXPANSION_P (TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0)))
4061 tree expansion = TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0);
4062 tree pattern = PACK_EXPANSION_PATTERN (expansion);
4063 /* So we have an argument_pack<P...>. We want to test if P
4064 is actually PARM_PACK. We will not use cp_tree_equal to
4065 test P and PARM_PACK because during type fixup (by
4066 fixup_template_parm) P can be a pre-fixup version of a
4067 type and PARM_PACK be its post-fixup version.
4068 cp_tree_equal would consider them as different even
4069 though we would want to consider them compatible for our
4070 precise purpose here.
4072 Thus we are going to consider that P and PARM_PACK are
4073 compatible if they have the same DECL. */
4074 if ((/* If ARG_PACK is a type parameter pack named by the
4075 same DECL as parm_pack ... */
4077 && TYPE_P (parm_pack)
4078 && TYPE_NAME (pattern) == TYPE_NAME (parm_pack))
4079 /* ... or if PARM_PACK is a non-type parameter named by the
4080 same DECL as ARG_PACK. Note that PARM_PACK being a
4081 non-type parameter means it's either a PARM_DECL or a
4082 TEMPLATE_PARM_INDEX. */
4083 || (TREE_CODE (pattern) == TEMPLATE_PARM_INDEX
4084 && ((TREE_CODE (parm_pack) == PARM_DECL
4085 && (TEMPLATE_PARM_DECL (pattern)
4086 == TEMPLATE_PARM_DECL (DECL_INITIAL (parm_pack))))
4087 || (TREE_CODE (parm_pack) == TEMPLATE_PARM_INDEX
4088 && (TEMPLATE_PARM_DECL (pattern)
4089 == TEMPLATE_PARM_DECL (parm_pack))))))
4090 && template_parameter_pack_p (pattern))
4096 /* Within the declaration of a template, return all levels of template
4097 parameters that apply. The template parameters are represented as
4098 a TREE_VEC, in the form documented in cp-tree.h for template
4102 current_template_args (void)
4105 tree args = NULL_TREE;
4106 int length = TMPL_PARMS_DEPTH (current_template_parms);
4109 /* If there is only one level of template parameters, we do not
4110 create a TREE_VEC of TREE_VECs. Instead, we return a single
4111 TREE_VEC containing the arguments. */
4113 args = make_tree_vec (length);
4115 for (header = current_template_parms; header; header = TREE_CHAIN (header))
4117 tree a = copy_node (TREE_VALUE (header));
4120 TREE_TYPE (a) = NULL_TREE;
4121 for (i = TREE_VEC_LENGTH (a) - 1; i >= 0; --i)
4122 TREE_VEC_ELT (a, i) = template_parm_to_arg (TREE_VEC_ELT (a, i));
4124 #ifdef ENABLE_CHECKING
4125 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (a, TREE_VEC_LENGTH (a));
4129 TREE_VEC_ELT (args, --l) = a;
4134 if (length > 1 && TREE_VEC_ELT (args, 0) == NULL_TREE)
4135 /* This can happen for template parms of a template template
4138 template<template<class T, class U> class TT> struct S;
4140 Consider the level of the parms of TT; T and U both have
4141 level 2; TT has no template parm of level 1. So in this case
4142 the first element of full_template_args is NULL_TREE. If we
4143 leave it like this TMPL_ARG_DEPTH on args returns 1 instead
4144 of 2. This will make tsubst wrongly consider that T and U
4145 have level 1. Instead, let's create a dummy vector as the
4146 first element of full_template_args so that TMPL_ARG_DEPTH
4147 returns the correct depth for args. */
4148 TREE_VEC_ELT (args, 0) = make_tree_vec (1);
4152 /* Update the declared TYPE by doing any lookups which were thought to be
4153 dependent, but are not now that we know the SCOPE of the declarator. */
4156 maybe_update_decl_type (tree orig_type, tree scope)
4158 tree type = orig_type;
4160 if (type == NULL_TREE)
4163 if (TREE_CODE (orig_type) == TYPE_DECL)
4164 type = TREE_TYPE (type);
4166 if (scope && TYPE_P (scope) && dependent_type_p (scope)
4167 && dependent_type_p (type)
4168 /* Don't bother building up the args in this case. */
4169 && TREE_CODE (type) != TEMPLATE_TYPE_PARM)
4171 /* tsubst in the args corresponding to the template parameters,
4172 including auto if present. Most things will be unchanged, but
4173 make_typename_type and tsubst_qualified_id will resolve
4174 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4175 tree args = current_template_args ();
4176 tree auto_node = type_uses_auto (type);
4180 tree auto_vec = make_tree_vec (1);
4181 TREE_VEC_ELT (auto_vec, 0) = auto_node;
4182 args = add_to_template_args (args, auto_vec);
4184 pushed = push_scope (scope);
4185 type = tsubst (type, args, tf_warning_or_error, NULL_TREE);
4190 if (type == error_mark_node)
4193 if (TREE_CODE (orig_type) == TYPE_DECL)
4195 if (same_type_p (type, TREE_TYPE (orig_type)))
4198 type = TYPE_NAME (type);
4203 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4204 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
4205 a member template. Used by push_template_decl below. */
4208 build_template_decl (tree decl, tree parms, bool member_template_p)
4210 tree tmpl = build_lang_decl (TEMPLATE_DECL, DECL_NAME (decl), NULL_TREE);
4211 DECL_TEMPLATE_PARMS (tmpl) = parms;
4212 DECL_CONTEXT (tmpl) = DECL_CONTEXT (decl);
4213 DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl);
4214 DECL_MEMBER_TEMPLATE_P (tmpl) = member_template_p;
4219 struct template_parm_data
4221 /* The level of the template parameters we are currently
4225 /* The index of the specialization argument we are currently
4229 /* An array whose size is the number of template parameters. The
4230 elements are nonzero if the parameter has been used in any one
4231 of the arguments processed so far. */
4234 /* An array whose size is the number of template arguments. The
4235 elements are nonzero if the argument makes use of template
4236 parameters of this level. */
4237 int* arg_uses_template_parms;
4240 /* Subroutine of push_template_decl used to see if each template
4241 parameter in a partial specialization is used in the explicit
4242 argument list. If T is of the LEVEL given in DATA (which is
4243 treated as a template_parm_data*), then DATA->PARMS is marked
4247 mark_template_parm (tree t, void* data)
4251 struct template_parm_data* tpd = (struct template_parm_data*) data;
4253 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
4255 level = TEMPLATE_PARM_LEVEL (t);
4256 idx = TEMPLATE_PARM_IDX (t);
4260 level = TEMPLATE_TYPE_LEVEL (t);
4261 idx = TEMPLATE_TYPE_IDX (t);
4264 if (level == tpd->level)
4266 tpd->parms[idx] = 1;
4267 tpd->arg_uses_template_parms[tpd->current_arg] = 1;
4270 /* Return zero so that for_each_template_parm will continue the
4271 traversal of the tree; we want to mark *every* template parm. */
4275 /* Process the partial specialization DECL. */
4278 process_partial_specialization (tree decl)
4280 tree type = TREE_TYPE (decl);
4281 tree maintmpl = CLASSTYPE_TI_TEMPLATE (type);
4282 tree specargs = CLASSTYPE_TI_ARGS (type);
4283 tree inner_args = INNERMOST_TEMPLATE_ARGS (specargs);
4284 tree main_inner_parms = DECL_INNERMOST_TEMPLATE_PARMS (maintmpl);
4287 int nargs = TREE_VEC_LENGTH (inner_args);
4290 bool did_error_intro = false;
4291 struct template_parm_data tpd;
4292 struct template_parm_data tpd2;
4294 gcc_assert (current_template_parms);
4296 inner_parms = INNERMOST_TEMPLATE_PARMS (current_template_parms);
4297 ntparms = TREE_VEC_LENGTH (inner_parms);
4299 /* We check that each of the template parameters given in the
4300 partial specialization is used in the argument list to the
4301 specialization. For example:
4303 template <class T> struct S;
4304 template <class T> struct S<T*>;
4306 The second declaration is OK because `T*' uses the template
4307 parameter T, whereas
4309 template <class T> struct S<int>;
4311 is no good. Even trickier is:
4322 The S2<T> declaration is actually invalid; it is a
4323 full-specialization. Of course,
4326 struct S2<T (*)(U)>;
4328 or some such would have been OK. */
4329 tpd.level = TMPL_PARMS_DEPTH (current_template_parms);
4330 tpd.parms = XALLOCAVEC (int, ntparms);
4331 memset (tpd.parms, 0, sizeof (int) * ntparms);
4333 tpd.arg_uses_template_parms = XALLOCAVEC (int, nargs);
4334 memset (tpd.arg_uses_template_parms, 0, sizeof (int) * nargs);
4335 for (i = 0; i < nargs; ++i)
4337 tpd.current_arg = i;
4338 for_each_template_parm (TREE_VEC_ELT (inner_args, i),
4339 &mark_template_parm,
4342 /*include_nondeduced_p=*/false);
4344 for (i = 0; i < ntparms; ++i)
4345 if (tpd.parms[i] == 0)
4347 /* One of the template parms was not used in the
4349 if (!did_error_intro)
4351 error ("template parameters not used in partial specialization:");
4352 did_error_intro = true;
4355 error (" %qD", TREE_VALUE (TREE_VEC_ELT (inner_parms, i)));
4358 if (did_error_intro)
4359 return error_mark_node;
4361 /* [temp.class.spec]
4363 The argument list of the specialization shall not be identical to
4364 the implicit argument list of the primary template. */
4365 if (comp_template_args
4367 INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE
4369 error ("partial specialization %qT does not specialize any template arguments", type);
4371 /* [temp.class.spec]
4373 A partially specialized non-type argument expression shall not
4374 involve template parameters of the partial specialization except
4375 when the argument expression is a simple identifier.
4377 The type of a template parameter corresponding to a specialized
4378 non-type argument shall not be dependent on a parameter of the
4381 Also, we verify that pack expansions only occur at the
4382 end of the argument list. */
4383 gcc_assert (nargs == DECL_NTPARMS (maintmpl));
4385 for (i = 0; i < nargs; ++i)
4387 tree parm = TREE_VALUE (TREE_VEC_ELT (main_inner_parms, i));
4388 tree arg = TREE_VEC_ELT (inner_args, i);
4389 tree packed_args = NULL_TREE;
4392 if (ARGUMENT_PACK_P (arg))
4394 /* Extract the arguments from the argument pack. We'll be
4395 iterating over these in the following loop. */
4396 packed_args = ARGUMENT_PACK_ARGS (arg);
4397 len = TREE_VEC_LENGTH (packed_args);
4400 for (j = 0; j < len; j++)
4403 /* Get the Jth argument in the parameter pack. */
4404 arg = TREE_VEC_ELT (packed_args, j);
4406 if (PACK_EXPANSION_P (arg))
4408 /* Pack expansions must come at the end of the
4410 if ((packed_args && j < len - 1)
4411 || (!packed_args && i < nargs - 1))
4413 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
4414 error ("parameter pack argument %qE must be at the "
4415 "end of the template argument list", arg);
4417 error ("parameter pack argument %qT must be at the "
4418 "end of the template argument list", arg);
4422 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
4423 /* We only care about the pattern. */
4424 arg = PACK_EXPANSION_PATTERN (arg);
4426 if (/* These first two lines are the `non-type' bit. */
4428 && TREE_CODE (arg) != TEMPLATE_DECL
4429 /* This next line is the `argument expression is not just a
4430 simple identifier' condition and also the `specialized
4431 non-type argument' bit. */
4432 && TREE_CODE (arg) != TEMPLATE_PARM_INDEX)
4434 if ((!packed_args && tpd.arg_uses_template_parms[i])
4435 || (packed_args && uses_template_parms (arg)))
4436 error ("template argument %qE involves template parameter(s)",
4440 /* Look at the corresponding template parameter,
4441 marking which template parameters its type depends
4443 tree type = TREE_TYPE (parm);
4447 /* We haven't yet initialized TPD2. Do so now. */
4448 tpd2.arg_uses_template_parms = XALLOCAVEC (int, nargs);
4449 /* The number of parameters here is the number in the
4450 main template, which, as checked in the assertion
4452 tpd2.parms = XALLOCAVEC (int, nargs);
4454 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (maintmpl));
4457 /* Mark the template parameters. But this time, we're
4458 looking for the template parameters of the main
4459 template, not in the specialization. */
4460 tpd2.current_arg = i;
4461 tpd2.arg_uses_template_parms[i] = 0;
4462 memset (tpd2.parms, 0, sizeof (int) * nargs);
4463 for_each_template_parm (type,
4464 &mark_template_parm,
4467 /*include_nondeduced_p=*/false);
4469 if (tpd2.arg_uses_template_parms [i])
4471 /* The type depended on some template parameters.
4472 If they are fully specialized in the
4473 specialization, that's OK. */
4476 for (j = 0; j < nargs; ++j)
4477 if (tpd2.parms[j] != 0
4478 && tpd.arg_uses_template_parms [j])
4481 error_n (input_location, count,
4482 "type %qT of template argument %qE depends "
4483 "on a template parameter",
4484 "type %qT of template argument %qE depends "
4485 "on template parameters",
4494 /* We should only get here once. */
4495 gcc_assert (!COMPLETE_TYPE_P (type));
4497 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)
4498 = tree_cons (specargs, inner_parms,
4499 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl));
4500 TREE_TYPE (DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)) = type;
4502 for (inst = DECL_TEMPLATE_INSTANTIATIONS (maintmpl); inst;
4503 inst = TREE_CHAIN (inst))
4505 tree inst_type = TREE_VALUE (inst);
4506 if (COMPLETE_TYPE_P (inst_type)
4507 && CLASSTYPE_IMPLICIT_INSTANTIATION (inst_type))
4509 tree spec = most_specialized_class (inst_type, maintmpl, tf_none);
4510 if (spec && TREE_TYPE (spec) == type)
4511 permerror (input_location,
4512 "partial specialization of %qT after instantiation "
4513 "of %qT", type, inst_type);
4520 /* Check that a template declaration's use of default arguments and
4521 parameter packs is not invalid. Here, PARMS are the template
4522 parameters. IS_PRIMARY is nonzero if DECL is the thing declared by
4523 a primary template. IS_PARTIAL is nonzero if DECL is a partial
4527 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4528 declaration (but not a definition); 1 indicates a declaration, 2
4529 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4530 emitted for extraneous default arguments.
4532 Returns TRUE if there were no errors found, FALSE otherwise. */
4535 check_default_tmpl_args (tree decl, tree parms, int is_primary,
4536 int is_partial, int is_friend_decl)
4539 int last_level_to_check;
4541 bool no_errors = true;
4545 A default template-argument shall not be specified in a
4546 function template declaration or a function template definition, nor
4547 in the template-parameter-list of the definition of a member of a
4550 if (TREE_CODE (CP_DECL_CONTEXT (decl)) == FUNCTION_DECL)
4551 /* You can't have a function template declaration in a local
4552 scope, nor you can you define a member of a class template in a
4556 if (current_class_type
4557 && !TYPE_BEING_DEFINED (current_class_type)
4558 && DECL_LANG_SPECIFIC (decl)
4559 && DECL_DECLARES_FUNCTION_P (decl)
4560 /* If this is either a friend defined in the scope of the class
4561 or a member function. */
4562 && (DECL_FUNCTION_MEMBER_P (decl)
4563 ? same_type_p (DECL_CONTEXT (decl), current_class_type)
4564 : DECL_FRIEND_CONTEXT (decl)
4565 ? same_type_p (DECL_FRIEND_CONTEXT (decl), current_class_type)
4567 /* And, if it was a member function, it really was defined in
4568 the scope of the class. */
4569 && (!DECL_FUNCTION_MEMBER_P (decl)
4570 || DECL_INITIALIZED_IN_CLASS_P (decl)))
4571 /* We already checked these parameters when the template was
4572 declared, so there's no need to do it again now. This function
4573 was defined in class scope, but we're processing it's body now
4574 that the class is complete. */
4577 /* Core issue 226 (C++0x only): the following only applies to class
4579 if ((cxx_dialect == cxx98) || TREE_CODE (decl) != FUNCTION_DECL)
4583 If a template-parameter has a default template-argument, all
4584 subsequent template-parameters shall have a default
4585 template-argument supplied. */
4586 for (parm_level = parms; parm_level; parm_level = TREE_CHAIN (parm_level))
4588 tree inner_parms = TREE_VALUE (parm_level);
4589 int ntparms = TREE_VEC_LENGTH (inner_parms);
4590 int seen_def_arg_p = 0;
4593 for (i = 0; i < ntparms; ++i)
4595 tree parm = TREE_VEC_ELT (inner_parms, i);
4597 if (parm == error_mark_node)
4600 if (TREE_PURPOSE (parm))
4602 else if (seen_def_arg_p
4603 && !template_parameter_pack_p (TREE_VALUE (parm)))
4605 error ("no default argument for %qD", TREE_VALUE (parm));
4606 /* For better subsequent error-recovery, we indicate that
4607 there should have been a default argument. */
4608 TREE_PURPOSE (parm) = error_mark_node;
4614 /* Don't complain about an enclosing partial
4616 && parm_level == parms
4617 && TREE_CODE (decl) == TYPE_DECL
4619 && template_parameter_pack_p (TREE_VALUE (parm)))
4621 /* A primary class template can only have one
4622 parameter pack, at the end of the template
4625 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL)
4626 error ("parameter pack %qE must be at the end of the"
4627 " template parameter list", TREE_VALUE (parm));
4629 error ("parameter pack %qT must be at the end of the"
4630 " template parameter list",
4631 TREE_TYPE (TREE_VALUE (parm)));
4633 TREE_VALUE (TREE_VEC_ELT (inner_parms, i))
4641 if (((cxx_dialect == cxx98) && TREE_CODE (decl) != TYPE_DECL)
4645 /* For an ordinary class template, default template arguments are
4646 allowed at the innermost level, e.g.:
4647 template <class T = int>
4649 but, in a partial specialization, they're not allowed even
4650 there, as we have in [temp.class.spec]:
4652 The template parameter list of a specialization shall not
4653 contain default template argument values.
4655 So, for a partial specialization, or for a function template
4656 (in C++98/C++03), we look at all of them. */
4659 /* But, for a primary class template that is not a partial
4660 specialization we look at all template parameters except the
4662 parms = TREE_CHAIN (parms);
4664 /* Figure out what error message to issue. */
4665 if (is_friend_decl == 2)
4666 msg = G_("default template arguments may not be used in function template "
4667 "friend re-declaration");
4668 else if (is_friend_decl)
4669 msg = G_("default template arguments may not be used in function template "
4670 "friend declarations");
4671 else if (TREE_CODE (decl) == FUNCTION_DECL && (cxx_dialect == cxx98))
4672 msg = G_("default template arguments may not be used in function templates "
4673 "without -std=c++11 or -std=gnu++11");
4674 else if (is_partial)
4675 msg = G_("default template arguments may not be used in "
4676 "partial specializations");
4678 msg = G_("default argument for template parameter for class enclosing %qD");
4680 if (current_class_type && TYPE_BEING_DEFINED (current_class_type))
4681 /* If we're inside a class definition, there's no need to
4682 examine the parameters to the class itself. On the one
4683 hand, they will be checked when the class is defined, and,
4684 on the other, default arguments are valid in things like:
4685 template <class T = double>
4686 struct S { template <class U> void f(U); };
4687 Here the default argument for `S' has no bearing on the
4688 declaration of `f'. */
4689 last_level_to_check = template_class_depth (current_class_type) + 1;
4691 /* Check everything. */
4692 last_level_to_check = 0;
4694 for (parm_level = parms;
4695 parm_level && TMPL_PARMS_DEPTH (parm_level) >= last_level_to_check;
4696 parm_level = TREE_CHAIN (parm_level))
4698 tree inner_parms = TREE_VALUE (parm_level);
4702 ntparms = TREE_VEC_LENGTH (inner_parms);
4703 for (i = 0; i < ntparms; ++i)
4705 if (TREE_VEC_ELT (inner_parms, i) == error_mark_node)
4708 if (TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)))
4713 if (is_friend_decl == 2)
4720 /* Clear out the default argument so that we are not
4722 TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)) = NULL_TREE;
4726 /* At this point, if we're still interested in issuing messages,
4727 they must apply to classes surrounding the object declared. */
4729 msg = G_("default argument for template parameter for class "
4736 /* Worker for push_template_decl_real, called via
4737 for_each_template_parm. DATA is really an int, indicating the
4738 level of the parameters we are interested in. If T is a template
4739 parameter of that level, return nonzero. */
4742 template_parm_this_level_p (tree t, void* data)
4744 int this_level = *(int *)data;
4747 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
4748 level = TEMPLATE_PARM_LEVEL (t);
4750 level = TEMPLATE_TYPE_LEVEL (t);
4751 return level == this_level;
4754 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4755 parameters given by current_template_args, or reuses a
4756 previously existing one, if appropriate. Returns the DECL, or an
4757 equivalent one, if it is replaced via a call to duplicate_decls.
4759 If IS_FRIEND is true, DECL is a friend declaration. */
4762 push_template_decl_real (tree decl, bool is_friend)
4770 int new_template_p = 0;
4771 /* True if the template is a member template, in the sense of
4773 bool member_template_p = false;
4775 if (decl == error_mark_node || !current_template_parms)
4776 return error_mark_node;
4778 /* See if this is a partial specialization. */
4779 is_partial = (DECL_IMPLICIT_TYPEDEF_P (decl)
4780 && TREE_CODE (TREE_TYPE (decl)) != ENUMERAL_TYPE
4781 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)));
4783 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_FRIEND_P (decl))
4787 /* For a friend, we want the context of the friend function, not
4788 the type of which it is a friend. */
4789 ctx = CP_DECL_CONTEXT (decl);
4790 else if (CP_DECL_CONTEXT (decl)
4791 && TREE_CODE (CP_DECL_CONTEXT (decl)) != NAMESPACE_DECL)
4792 /* In the case of a virtual function, we want the class in which
4794 ctx = CP_DECL_CONTEXT (decl);
4796 /* Otherwise, if we're currently defining some class, the DECL
4797 is assumed to be a member of the class. */
4798 ctx = current_scope ();
4800 if (ctx && TREE_CODE (ctx) == NAMESPACE_DECL)
4803 if (!DECL_CONTEXT (decl))
4804 DECL_CONTEXT (decl) = FROB_CONTEXT (current_namespace);
4806 /* See if this is a primary template. */
4807 if (is_friend && ctx)
4808 /* A friend template that specifies a class context, i.e.
4809 template <typename T> friend void A<T>::f();
4813 primary = template_parm_scope_p ();
4817 if (DECL_CLASS_SCOPE_P (decl))
4818 member_template_p = true;
4819 if (TREE_CODE (decl) == TYPE_DECL
4820 && ANON_AGGRNAME_P (DECL_NAME (decl)))
4822 error ("template class without a name");
4823 return error_mark_node;
4825 else if (TREE_CODE (decl) == FUNCTION_DECL)
4827 if (DECL_DESTRUCTOR_P (decl))
4831 A destructor shall not be a member template. */
4832 error ("destructor %qD declared as member template", decl);
4833 return error_mark_node;
4835 if (NEW_DELETE_OPNAME_P (DECL_NAME (decl))
4836 && (!prototype_p (TREE_TYPE (decl))
4837 || TYPE_ARG_TYPES (TREE_TYPE (decl)) == void_list_node
4838 || !TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (decl)))
4839 || (TREE_CHAIN (TYPE_ARG_TYPES ((TREE_TYPE (decl))))
4840 == void_list_node)))
4842 /* [basic.stc.dynamic.allocation]
4844 An allocation function can be a function
4845 template. ... Template allocation functions shall
4846 have two or more parameters. */
4847 error ("invalid template declaration of %qD", decl);
4848 return error_mark_node;
4851 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4852 && CLASS_TYPE_P (TREE_TYPE (decl)))
4854 else if (TREE_CODE (decl) == TYPE_DECL
4855 && TYPE_DECL_ALIAS_P (decl))
4856 /* alias-declaration */
4857 gcc_assert (!DECL_ARTIFICIAL (decl));
4860 error ("template declaration of %q#D", decl);
4861 return error_mark_node;
4865 /* Check to see that the rules regarding the use of default
4866 arguments are not being violated. */
4867 check_default_tmpl_args (decl, current_template_parms,
4868 primary, is_partial, /*is_friend_decl=*/0);
4870 /* Ensure that there are no parameter packs in the type of this
4871 declaration that have not been expanded. */
4872 if (TREE_CODE (decl) == FUNCTION_DECL)
4874 /* Check each of the arguments individually to see if there are
4875 any bare parameter packs. */
4876 tree type = TREE_TYPE (decl);
4877 tree arg = DECL_ARGUMENTS (decl);
4878 tree argtype = TYPE_ARG_TYPES (type);
4880 while (arg && argtype)
4882 if (!FUNCTION_PARAMETER_PACK_P (arg)
4883 && check_for_bare_parameter_packs (TREE_TYPE (arg)))
4885 /* This is a PARM_DECL that contains unexpanded parameter
4886 packs. We have already complained about this in the
4887 check_for_bare_parameter_packs call, so just replace
4888 these types with ERROR_MARK_NODE. */
4889 TREE_TYPE (arg) = error_mark_node;
4890 TREE_VALUE (argtype) = error_mark_node;
4893 arg = DECL_CHAIN (arg);
4894 argtype = TREE_CHAIN (argtype);
4897 /* Check for bare parameter packs in the return type and the
4898 exception specifiers. */
4899 if (check_for_bare_parameter_packs (TREE_TYPE (type)))
4900 /* Errors were already issued, set return type to int
4901 as the frontend doesn't expect error_mark_node as
4903 TREE_TYPE (type) = integer_type_node;
4904 if (check_for_bare_parameter_packs (TYPE_RAISES_EXCEPTIONS (type)))
4905 TYPE_RAISES_EXCEPTIONS (type) = NULL_TREE;
4907 else if (check_for_bare_parameter_packs (TREE_TYPE (decl)))
4909 TREE_TYPE (decl) = error_mark_node;
4910 return error_mark_node;
4914 return process_partial_specialization (decl);
4916 args = current_template_args ();
4919 || TREE_CODE (ctx) == FUNCTION_DECL
4920 || (CLASS_TYPE_P (ctx) && TYPE_BEING_DEFINED (ctx))
4921 || (is_friend && !DECL_TEMPLATE_INFO (decl)))
4923 if (DECL_LANG_SPECIFIC (decl)
4924 && DECL_TEMPLATE_INFO (decl)
4925 && DECL_TI_TEMPLATE (decl))
4926 tmpl = DECL_TI_TEMPLATE (decl);
4927 /* If DECL is a TYPE_DECL for a class-template, then there won't
4928 be DECL_LANG_SPECIFIC. The information equivalent to
4929 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4930 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4931 && TYPE_TEMPLATE_INFO (TREE_TYPE (decl))
4932 && TYPE_TI_TEMPLATE (TREE_TYPE (decl)))
4934 /* Since a template declaration already existed for this
4935 class-type, we must be redeclaring it here. Make sure
4936 that the redeclaration is valid. */
4937 redeclare_class_template (TREE_TYPE (decl),
4938 current_template_parms);
4939 /* We don't need to create a new TEMPLATE_DECL; just use the
4940 one we already had. */
4941 tmpl = TYPE_TI_TEMPLATE (TREE_TYPE (decl));
4945 tmpl = build_template_decl (decl, current_template_parms,
4949 if (DECL_LANG_SPECIFIC (decl)
4950 && DECL_TEMPLATE_SPECIALIZATION (decl))
4952 /* A specialization of a member template of a template
4954 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
4955 DECL_TEMPLATE_INFO (tmpl) = DECL_TEMPLATE_INFO (decl);
4956 DECL_TEMPLATE_INFO (decl) = NULL_TREE;
4962 tree a, t, current, parms;
4964 tree tinfo = get_template_info (decl);
4968 error ("template definition of non-template %q#D", decl);
4969 return error_mark_node;
4972 tmpl = TI_TEMPLATE (tinfo);
4974 if (DECL_FUNCTION_TEMPLATE_P (tmpl)
4975 && DECL_TEMPLATE_INFO (decl) && DECL_TI_ARGS (decl)
4976 && DECL_TEMPLATE_SPECIALIZATION (decl)
4977 && DECL_MEMBER_TEMPLATE_P (tmpl))
4981 /* The declaration is a specialization of a member
4982 template, declared outside the class. Therefore, the
4983 innermost template arguments will be NULL, so we
4984 replace them with the arguments determined by the
4985 earlier call to check_explicit_specialization. */
4986 args = DECL_TI_ARGS (decl);
4989 = build_template_decl (decl, current_template_parms,
4991 DECL_TEMPLATE_RESULT (new_tmpl) = decl;
4992 TREE_TYPE (new_tmpl) = TREE_TYPE (decl);
4993 DECL_TI_TEMPLATE (decl) = new_tmpl;
4994 SET_DECL_TEMPLATE_SPECIALIZATION (new_tmpl);
4995 DECL_TEMPLATE_INFO (new_tmpl)
4996 = build_template_info (tmpl, args);
4998 register_specialization (new_tmpl,
4999 most_general_template (tmpl),
5005 /* Make sure the template headers we got make sense. */
5007 parms = DECL_TEMPLATE_PARMS (tmpl);
5008 i = TMPL_PARMS_DEPTH (parms);
5009 if (TMPL_ARGS_DEPTH (args) != i)
5011 error ("expected %d levels of template parms for %q#D, got %d",
5012 i, decl, TMPL_ARGS_DEPTH (args));
5015 for (current = decl; i > 0; --i, parms = TREE_CHAIN (parms))
5017 a = TMPL_ARGS_LEVEL (args, i);
5018 t = INNERMOST_TEMPLATE_PARMS (parms);
5020 if (TREE_VEC_LENGTH (t) != TREE_VEC_LENGTH (a))
5022 if (current == decl)
5023 error ("got %d template parameters for %q#D",
5024 TREE_VEC_LENGTH (a), decl);
5026 error ("got %d template parameters for %q#T",
5027 TREE_VEC_LENGTH (a), current);
5028 error (" but %d required", TREE_VEC_LENGTH (t));
5029 return error_mark_node;
5032 if (current == decl)
5034 else if (current == NULL_TREE)
5035 /* Can happen in erroneous input. */
5038 current = (TYPE_P (current)
5039 ? TYPE_CONTEXT (current)
5040 : DECL_CONTEXT (current));
5043 /* Check that the parms are used in the appropriate qualifying scopes
5044 in the declarator. */
5045 if (!comp_template_args
5047 TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (tmpl)))))
5050 template arguments to %qD do not match original template %qD",
5051 decl, DECL_TEMPLATE_RESULT (tmpl));
5052 if (!uses_template_parms (TI_ARGS (tinfo)))
5053 inform (input_location, "use template<> for an explicit specialization");
5054 /* Avoid crash in import_export_decl. */
5055 DECL_INTERFACE_KNOWN (decl) = 1;
5056 return error_mark_node;
5060 DECL_TEMPLATE_RESULT (tmpl) = decl;
5061 TREE_TYPE (tmpl) = TREE_TYPE (decl);
5063 /* Push template declarations for global functions and types. Note
5064 that we do not try to push a global template friend declared in a
5065 template class; such a thing may well depend on the template
5066 parameters of the class. */
5067 if (new_template_p && !ctx
5068 && !(is_friend && template_class_depth (current_class_type) > 0))
5070 tmpl = pushdecl_namespace_level (tmpl, is_friend);
5071 if (tmpl == error_mark_node)
5072 return error_mark_node;
5074 /* Hide template friend classes that haven't been declared yet. */
5075 if (is_friend && TREE_CODE (decl) == TYPE_DECL)
5077 DECL_ANTICIPATED (tmpl) = 1;
5078 DECL_FRIEND_P (tmpl) = 1;
5084 tree parms = DECL_TEMPLATE_PARMS (tmpl);
5087 DECL_PRIMARY_TEMPLATE (tmpl) = tmpl;
5088 if (DECL_CONV_FN_P (tmpl))
5090 int depth = TMPL_PARMS_DEPTH (parms);
5092 /* It is a conversion operator. See if the type converted to
5093 depends on innermost template operands. */
5095 if (uses_template_parms_level (TREE_TYPE (TREE_TYPE (tmpl)),
5097 DECL_TEMPLATE_CONV_FN_P (tmpl) = 1;
5100 /* Give template template parms a DECL_CONTEXT of the template
5101 for which they are a parameter. */
5102 parms = INNERMOST_TEMPLATE_PARMS (parms);
5103 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
5105 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
5106 if (TREE_CODE (parm) == TEMPLATE_DECL)
5107 DECL_CONTEXT (parm) = tmpl;
5111 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5112 back to its most general template. If TMPL is a specialization,
5113 ARGS may only have the innermost set of arguments. Add the missing
5114 argument levels if necessary. */
5115 if (DECL_TEMPLATE_INFO (tmpl))
5116 args = add_outermost_template_args (DECL_TI_ARGS (tmpl), args);
5118 info = build_template_info (tmpl, args);
5120 if (DECL_IMPLICIT_TYPEDEF_P (decl))
5121 SET_TYPE_TEMPLATE_INFO (TREE_TYPE (tmpl), info);
5124 if (primary && !DECL_LANG_SPECIFIC (decl))
5125 retrofit_lang_decl (decl);
5126 if (DECL_LANG_SPECIFIC (decl))
5127 DECL_TEMPLATE_INFO (decl) = info;
5130 return DECL_TEMPLATE_RESULT (tmpl);
5134 push_template_decl (tree decl)
5136 return push_template_decl_real (decl, false);
5139 /* Called when a class template TYPE is redeclared with the indicated
5140 template PARMS, e.g.:
5142 template <class T> struct S;
5143 template <class T> struct S {}; */
5146 redeclare_class_template (tree type, tree parms)
5152 if (!TYPE_TEMPLATE_INFO (type))
5154 error ("%qT is not a template type", type);
5158 tmpl = TYPE_TI_TEMPLATE (type);
5159 if (!PRIMARY_TEMPLATE_P (tmpl))
5160 /* The type is nested in some template class. Nothing to worry
5161 about here; there are no new template parameters for the nested
5167 error ("template specifiers not specified in declaration of %qD",
5172 parms = INNERMOST_TEMPLATE_PARMS (parms);
5173 tmpl_parms = DECL_INNERMOST_TEMPLATE_PARMS (tmpl);
5175 if (TREE_VEC_LENGTH (parms) != TREE_VEC_LENGTH (tmpl_parms))
5177 error_n (input_location, TREE_VEC_LENGTH (parms),
5178 "redeclared with %d template parameter",
5179 "redeclared with %d template parameters",
5180 TREE_VEC_LENGTH (parms));
5181 inform_n (input_location, TREE_VEC_LENGTH (tmpl_parms),
5182 "previous declaration %q+D used %d template parameter",
5183 "previous declaration %q+D used %d template parameters",
5184 tmpl, TREE_VEC_LENGTH (tmpl_parms));
5188 for (i = 0; i < TREE_VEC_LENGTH (tmpl_parms); ++i)
5195 if (TREE_VEC_ELT (tmpl_parms, i) == error_mark_node
5196 || TREE_VEC_ELT (parms, i) == error_mark_node)
5199 tmpl_parm = TREE_VALUE (TREE_VEC_ELT (tmpl_parms, i));
5200 if (tmpl_parm == error_mark_node)
5203 parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
5204 tmpl_default = TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i));
5205 parm_default = TREE_PURPOSE (TREE_VEC_ELT (parms, i));
5207 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5209 if (TREE_CODE (tmpl_parm) != TREE_CODE (parm)
5210 || (TREE_CODE (tmpl_parm) != TYPE_DECL
5211 && !same_type_p (TREE_TYPE (tmpl_parm), TREE_TYPE (parm)))
5212 || (TREE_CODE (tmpl_parm) != PARM_DECL
5213 && (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (tmpl_parm))
5214 != TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm))))
5215 || (TREE_CODE (tmpl_parm) == PARM_DECL
5216 && (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (tmpl_parm))
5217 != TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))))
5219 error ("template parameter %q+#D", tmpl_parm);
5220 error ("redeclared here as %q#D", parm);
5224 if (tmpl_default != NULL_TREE && parm_default != NULL_TREE)
5226 /* We have in [temp.param]:
5228 A template-parameter may not be given default arguments
5229 by two different declarations in the same scope. */
5230 error_at (input_location, "redefinition of default argument for %q#D", parm);
5231 inform (DECL_SOURCE_LOCATION (tmpl_parm),
5232 "original definition appeared here");
5236 if (parm_default != NULL_TREE)
5237 /* Update the previous template parameters (which are the ones
5238 that will really count) with the new default value. */
5239 TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i)) = parm_default;
5240 else if (tmpl_default != NULL_TREE)
5241 /* Update the new parameters, too; they'll be used as the
5242 parameters for any members. */
5243 TREE_PURPOSE (TREE_VEC_ELT (parms, i)) = tmpl_default;
5249 /* Simplify EXPR if it is a non-dependent expression. Returns the
5250 (possibly simplified) expression. */
5253 fold_non_dependent_expr_sfinae (tree expr, tsubst_flags_t complain)
5255 if (expr == NULL_TREE)
5258 /* If we're in a template, but EXPR isn't value dependent, simplify
5259 it. We're supposed to treat:
5261 template <typename T> void f(T[1 + 1]);
5262 template <typename T> void f(T[2]);
5264 as two declarations of the same function, for example. */
5265 if (processing_template_decl
5266 && !type_dependent_expression_p (expr)
5267 && potential_constant_expression (expr)
5268 && !value_dependent_expression_p (expr))
5270 HOST_WIDE_INT saved_processing_template_decl;
5272 saved_processing_template_decl = processing_template_decl;
5273 processing_template_decl = 0;
5274 expr = tsubst_copy_and_build (expr,
5277 /*in_decl=*/NULL_TREE,
5278 /*function_p=*/false,
5279 /*integral_constant_expression_p=*/true);
5280 processing_template_decl = saved_processing_template_decl;
5286 fold_non_dependent_expr (tree expr)
5288 return fold_non_dependent_expr_sfinae (expr, tf_error);
5291 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5292 template declaration, or a TYPE_DECL for an alias declaration. */
5295 alias_type_or_template_p (tree t)
5299 return ((TREE_CODE (t) == TYPE_DECL && TYPE_DECL_ALIAS_P (t))
5302 && TYPE_DECL_ALIAS_P (TYPE_NAME (t)))
5303 || DECL_ALIAS_TEMPLATE_P (t));
5306 /* Return TRUE iff is a specialization of an alias template. */
5309 alias_template_specialization_p (tree t)
5313 return (primary_template_instantiation_p (t)
5314 && DECL_ALIAS_TEMPLATE_P (TYPE_TI_TEMPLATE (t)));
5317 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5318 must be a function or a pointer-to-function type, as specified
5319 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5320 and check that the resulting function has external linkage. */
5323 convert_nontype_argument_function (tree type, tree expr)
5327 linkage_kind linkage;
5329 fn = instantiate_type (type, fns, tf_none);
5330 if (fn == error_mark_node)
5331 return error_mark_node;
5334 if (TREE_CODE (fn_no_ptr) == ADDR_EXPR)
5335 fn_no_ptr = TREE_OPERAND (fn_no_ptr, 0);
5336 if (BASELINK_P (fn_no_ptr))
5337 fn_no_ptr = BASELINK_FUNCTIONS (fn_no_ptr);
5339 /* [temp.arg.nontype]/1
5341 A template-argument for a non-type, non-template template-parameter
5344 -- the address of an object or function with external [C++11: or
5345 internal] linkage. */
5346 linkage = decl_linkage (fn_no_ptr);
5347 if (cxx_dialect >= cxx0x ? linkage == lk_none : linkage != lk_external)
5349 if (cxx_dialect >= cxx0x)
5350 error ("%qE is not a valid template argument for type %qT "
5351 "because %qD has no linkage",
5352 expr, type, fn_no_ptr);
5354 error ("%qE is not a valid template argument for type %qT "
5355 "because %qD does not have external linkage",
5356 expr, type, fn_no_ptr);
5363 /* Subroutine of convert_nontype_argument.
5364 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5365 Emit an error otherwise. */
5368 check_valid_ptrmem_cst_expr (tree type, tree expr,
5369 tsubst_flags_t complain)
5372 if (expr && (null_ptr_cst_p (expr) || TREE_CODE (expr) == PTRMEM_CST))
5374 if (cxx_dialect >= cxx0x && null_member_pointer_value_p (expr))
5376 if (complain & tf_error)
5378 error ("%qE is not a valid template argument for type %qT",
5380 error ("it must be a pointer-to-member of the form %<&X::Y%>");
5385 /* Returns TRUE iff the address of OP is value-dependent.
5387 14.6.2.4 [temp.dep.temp]:
5388 A non-integral non-type template-argument is dependent if its type is
5389 dependent or it has either of the following forms
5392 and contains a nested-name-specifier which specifies a class-name that
5393 names a dependent type.
5395 We generalize this to just say that the address of a member of a
5396 dependent class is value-dependent; the above doesn't cover the
5397 address of a static data member named with an unqualified-id. */
5400 has_value_dependent_address (tree op)
5402 /* We could use get_inner_reference here, but there's no need;
5403 this is only relevant for template non-type arguments, which
5404 can only be expressed as &id-expression. */
5407 tree ctx = CP_DECL_CONTEXT (op);
5408 if (TYPE_P (ctx) && dependent_type_p (ctx))
5415 /* The next set of functions are used for providing helpful explanatory
5416 diagnostics for failed overload resolution. Their messages should be
5417 indented by two spaces for consistency with the messages in
5421 unify_success (bool explain_p ATTRIBUTE_UNUSED)
5427 unify_parameter_deduction_failure (bool explain_p, tree parm)
5430 inform (input_location,
5431 " couldn't deduce template parameter %qD", parm);
5436 unify_invalid (bool explain_p ATTRIBUTE_UNUSED)
5442 unify_cv_qual_mismatch (bool explain_p, tree parm, tree arg)
5445 inform (input_location,
5446 " types %qT and %qT have incompatible cv-qualifiers",
5452 unify_type_mismatch (bool explain_p, tree parm, tree arg)
5455 inform (input_location, " mismatched types %qT and %qT", parm, arg);
5460 unify_parameter_pack_mismatch (bool explain_p, tree parm, tree arg)
5463 inform (input_location,
5464 " template parameter %qD is not a parameter pack, but "
5471 unify_ptrmem_cst_mismatch (bool explain_p, tree parm, tree arg)
5474 inform (input_location,
5475 " template argument %qE does not match "
5476 "pointer-to-member constant %qE",
5482 unify_expression_unequal (bool explain_p, tree parm, tree arg)
5485 inform (input_location, " %qE is not equivalent to %qE", parm, arg);
5490 unify_parameter_pack_inconsistent (bool explain_p, tree old_arg, tree new_arg)
5493 inform (input_location,
5494 " inconsistent parameter pack deduction with %qT and %qT",
5500 unify_inconsistency (bool explain_p, tree parm, tree first, tree second)
5503 inform (input_location,
5504 " deduced conflicting types for parameter %qT (%qT and %qT)",
5505 parm, first, second);
5510 unify_vla_arg (bool explain_p, tree arg)
5513 inform (input_location,
5514 " variable-sized array type %qT is not "
5515 "a valid template argument",
5521 unify_method_type_error (bool explain_p, tree arg)
5524 inform (input_location,
5525 " member function type %qT is not a valid template argument",
5531 unify_arity (bool explain_p, int have, int wanted)
5534 inform_n (input_location, wanted,
5535 " candidate expects %d argument, %d provided",
5536 " candidate expects %d arguments, %d provided",
5542 unify_too_many_arguments (bool explain_p, int have, int wanted)
5544 return unify_arity (explain_p, have, wanted);
5548 unify_too_few_arguments (bool explain_p, int have, int wanted)
5550 return unify_arity (explain_p, have, wanted);
5554 unify_arg_conversion (bool explain_p, tree to_type,
5555 tree from_type, tree arg)
5558 inform (input_location, " cannot convert %qE (type %qT) to type %qT",
5559 arg, from_type, to_type);
5564 unify_no_common_base (bool explain_p, enum template_base_result r,
5565 tree parm, tree arg)
5570 case tbr_ambiguous_baseclass:
5571 inform (input_location, " %qT is an ambiguous base class of %qT",
5575 inform (input_location, " %qT is not derived from %qT", arg, parm);
5582 unify_inconsistent_template_template_parameters (bool explain_p)
5585 inform (input_location,
5586 " template parameters of a template template argument are "
5587 "inconsistent with other deduced template arguments");
5592 unify_template_deduction_failure (bool explain_p, tree parm, tree arg)
5595 inform (input_location,
5596 " can't deduce a template for %qT from non-template type %qT",
5602 unify_template_argument_mismatch (bool explain_p, tree parm, tree arg)
5605 inform (input_location,
5606 " template argument %qE does not match %qD", arg, parm);
5611 unify_overload_resolution_failure (bool explain_p, tree arg)
5614 inform (input_location,
5615 " could not resolve address from overloaded function %qE",
5620 /* Attempt to convert the non-type template parameter EXPR to the
5621 indicated TYPE. If the conversion is successful, return the
5622 converted value. If the conversion is unsuccessful, return
5623 NULL_TREE if we issued an error message, or error_mark_node if we
5624 did not. We issue error messages for out-and-out bad template
5625 parameters, but not simply because the conversion failed, since we
5626 might be just trying to do argument deduction. Both TYPE and EXPR
5627 must be non-dependent.
5629 The conversion follows the special rules described in
5630 [temp.arg.nontype], and it is much more strict than an implicit
5633 This function is called twice for each template argument (see
5634 lookup_template_class for a more accurate description of this
5635 problem). This means that we need to handle expressions which
5636 are not valid in a C++ source, but can be created from the
5637 first call (for instance, casts to perform conversions). These
5638 hacks can go away after we fix the double coercion problem. */
5641 convert_nontype_argument (tree type, tree expr, tsubst_flags_t complain)
5645 /* Detect immediately string literals as invalid non-type argument.
5646 This special-case is not needed for correctness (we would easily
5647 catch this later), but only to provide better diagnostic for this
5648 common user mistake. As suggested by DR 100, we do not mention
5649 linkage issues in the diagnostic as this is not the point. */
5650 /* FIXME we're making this OK. */
5651 if (TREE_CODE (expr) == STRING_CST)
5653 if (complain & tf_error)
5654 error ("%qE is not a valid template argument for type %qT "
5655 "because string literals can never be used in this context",
5660 /* Add the ADDR_EXPR now for the benefit of
5661 value_dependent_expression_p. */
5662 if (TYPE_PTROBV_P (type)
5663 && TREE_CODE (TREE_TYPE (expr)) == ARRAY_TYPE)
5664 expr = decay_conversion (expr);
5666 /* If we are in a template, EXPR may be non-dependent, but still
5667 have a syntactic, rather than semantic, form. For example, EXPR
5668 might be a SCOPE_REF, rather than the VAR_DECL to which the
5669 SCOPE_REF refers. Preserving the qualifying scope is necessary
5670 so that access checking can be performed when the template is
5671 instantiated -- but here we need the resolved form so that we can
5672 convert the argument. */
5673 if (TYPE_REF_OBJ_P (type)
5674 && has_value_dependent_address (expr))
5675 /* If we want the address and it's value-dependent, don't fold. */;
5676 else if (!type_unknown_p (expr))
5677 expr = fold_non_dependent_expr_sfinae (expr, complain);
5678 if (error_operand_p (expr))
5679 return error_mark_node;
5680 expr_type = TREE_TYPE (expr);
5681 if (TREE_CODE (type) == REFERENCE_TYPE)
5682 expr = mark_lvalue_use (expr);
5684 expr = mark_rvalue_use (expr);
5686 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
5687 to a non-type argument of "nullptr". */
5688 if (expr == nullptr_node
5689 && (TYPE_PTR_P (type) || TYPE_PTR_TO_MEMBER_P (type)))
5690 expr = convert (type, expr);
5692 /* In C++11, integral or enumeration non-type template arguments can be
5693 arbitrary constant expressions. Pointer and pointer to
5694 member arguments can be general constant expressions that evaluate
5695 to a null value, but otherwise still need to be of a specific form. */
5696 if (cxx_dialect >= cxx0x)
5698 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
5699 expr = maybe_constant_value (expr);
5700 else if (TYPE_PTR_P (type)
5701 || (TYPE_PTR_TO_MEMBER_P (type)
5702 && TREE_CODE (expr) != PTRMEM_CST))
5704 tree folded = maybe_constant_value (expr);
5705 if (TYPE_PTR_P (type) ? integer_zerop (folded)
5706 : null_member_pointer_value_p (folded))
5711 /* HACK: Due to double coercion, we can get a
5712 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5713 which is the tree that we built on the first call (see
5714 below when coercing to reference to object or to reference to
5715 function). We just strip everything and get to the arg.
5716 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5718 if (TYPE_REF_OBJ_P (type) || TYPE_REFFN_P (type))
5720 tree probe_type, probe = expr;
5721 if (REFERENCE_REF_P (probe))
5722 probe = TREE_OPERAND (probe, 0);
5723 probe_type = TREE_TYPE (probe);
5724 if (TREE_CODE (probe) == NOP_EXPR)
5726 /* ??? Maybe we could use convert_from_reference here, but we
5727 would need to relax its constraints because the NOP_EXPR
5728 could actually change the type to something more cv-qualified,
5729 and this is not folded by convert_from_reference. */
5730 tree addr = TREE_OPERAND (probe, 0);
5731 gcc_assert (TREE_CODE (probe_type) == REFERENCE_TYPE);
5732 gcc_assert (TREE_CODE (addr) == ADDR_EXPR);
5733 gcc_assert (TREE_CODE (TREE_TYPE (addr)) == POINTER_TYPE);
5734 gcc_assert (same_type_ignoring_top_level_qualifiers_p
5735 (TREE_TYPE (probe_type),
5736 TREE_TYPE (TREE_TYPE (addr))));
5738 expr = TREE_OPERAND (addr, 0);
5739 expr_type = TREE_TYPE (expr);
5743 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5744 parameter is a pointer to object, through decay and
5745 qualification conversion. Let's strip everything. */
5746 else if (TREE_CODE (expr) == NOP_EXPR && TYPE_PTROBV_P (type))
5749 gcc_assert (TREE_CODE (expr) == ADDR_EXPR);
5750 gcc_assert (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE);
5751 /* Skip the ADDR_EXPR only if it is part of the decay for
5752 an array. Otherwise, it is part of the original argument
5753 in the source code. */
5754 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == ARRAY_TYPE)
5755 expr = TREE_OPERAND (expr, 0);
5756 expr_type = TREE_TYPE (expr);
5759 /* [temp.arg.nontype]/5, bullet 1
5761 For a non-type template-parameter of integral or enumeration type,
5762 integral promotions (_conv.prom_) and integral conversions
5763 (_conv.integral_) are applied. */
5764 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
5766 tree t = build_integral_nontype_arg_conv (type, expr, complain);
5767 t = maybe_constant_value (t);
5768 if (t != error_mark_node)
5771 if (!same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (expr)))
5772 return error_mark_node;
5774 /* Notice that there are constant expressions like '4 % 0' which
5775 do not fold into integer constants. */
5776 if (TREE_CODE (expr) != INTEGER_CST)
5778 if (complain & tf_error)
5780 int errs = errorcount, warns = warningcount;
5781 expr = cxx_constant_value (expr);
5782 if (errorcount > errs || warningcount > warns)
5783 inform (EXPR_LOC_OR_HERE (expr),
5784 "in template argument for type %qT ", type);
5785 if (expr == error_mark_node)
5787 /* else cxx_constant_value complained but gave us
5788 a real constant, so go ahead. */
5789 gcc_assert (TREE_CODE (expr) == INTEGER_CST);
5795 /* [temp.arg.nontype]/5, bullet 2
5797 For a non-type template-parameter of type pointer to object,
5798 qualification conversions (_conv.qual_) and the array-to-pointer
5799 conversion (_conv.array_) are applied. */
5800 else if (TYPE_PTROBV_P (type))
5802 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5804 A template-argument for a non-type, non-template template-parameter
5805 shall be one of: [...]
5807 -- the name of a non-type template-parameter;
5808 -- the address of an object or function with external linkage, [...]
5809 expressed as "& id-expression" where the & is optional if the name
5810 refers to a function or array, or if the corresponding
5811 template-parameter is a reference.
5813 Here, we do not care about functions, as they are invalid anyway
5814 for a parameter of type pointer-to-object. */
5816 if (DECL_P (expr) && DECL_TEMPLATE_PARM_P (expr))
5817 /* Non-type template parameters are OK. */
5819 else if (cxx_dialect >= cxx0x && integer_zerop (expr))
5820 /* Null pointer values are OK in C++11. */;
5821 else if (TREE_CODE (expr) != ADDR_EXPR
5822 && TREE_CODE (expr_type) != ARRAY_TYPE)
5824 if (TREE_CODE (expr) == VAR_DECL)
5826 error ("%qD is not a valid template argument "
5827 "because %qD is a variable, not the address of "
5832 /* Other values, like integer constants, might be valid
5833 non-type arguments of some other type. */
5834 return error_mark_node;
5840 decl = ((TREE_CODE (expr) == ADDR_EXPR)
5841 ? TREE_OPERAND (expr, 0) : expr);
5842 if (TREE_CODE (decl) != VAR_DECL)
5844 error ("%qE is not a valid template argument of type %qT "
5845 "because %qE is not a variable",
5849 else if (cxx_dialect < cxx0x && !DECL_EXTERNAL_LINKAGE_P (decl))
5851 error ("%qE is not a valid template argument of type %qT "
5852 "because %qD does not have external linkage",
5856 else if (cxx_dialect >= cxx0x && decl_linkage (decl) == lk_none)
5858 error ("%qE is not a valid template argument of type %qT "
5859 "because %qD has no linkage",
5865 expr = decay_conversion (expr);
5866 if (expr == error_mark_node)
5867 return error_mark_node;
5869 expr = perform_qualification_conversions (type, expr);
5870 if (expr == error_mark_node)
5871 return error_mark_node;
5873 /* [temp.arg.nontype]/5, bullet 3
5875 For a non-type template-parameter of type reference to object, no
5876 conversions apply. The type referred to by the reference may be more
5877 cv-qualified than the (otherwise identical) type of the
5878 template-argument. The template-parameter is bound directly to the
5879 template-argument, which must be an lvalue. */
5880 else if (TYPE_REF_OBJ_P (type))
5882 if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type),
5884 return error_mark_node;
5886 if (!at_least_as_qualified_p (TREE_TYPE (type), expr_type))
5888 error ("%qE is not a valid template argument for type %qT "
5889 "because of conflicts in cv-qualification", expr, type);
5893 if (!real_lvalue_p (expr))
5895 error ("%qE is not a valid template argument for type %qT "
5896 "because it is not an lvalue", expr, type);
5900 /* [temp.arg.nontype]/1
5902 A template-argument for a non-type, non-template template-parameter
5903 shall be one of: [...]
5905 -- the address of an object or function with external linkage. */
5906 if (TREE_CODE (expr) == INDIRECT_REF
5907 && TYPE_REF_OBJ_P (TREE_TYPE (TREE_OPERAND (expr, 0))))
5909 expr = TREE_OPERAND (expr, 0);
5912 error ("%q#D is not a valid template argument for type %qT "
5913 "because a reference variable does not have a constant "
5914 "address", expr, type);
5921 error ("%qE is not a valid template argument for type %qT "
5922 "because it is not an object with external linkage",
5927 if (!DECL_EXTERNAL_LINKAGE_P (expr))
5929 error ("%qE is not a valid template argument for type %qT "
5930 "because object %qD has not external linkage",
5935 expr = build_nop (type, build_address (expr));
5937 /* [temp.arg.nontype]/5, bullet 4
5939 For a non-type template-parameter of type pointer to function, only
5940 the function-to-pointer conversion (_conv.func_) is applied. If the
5941 template-argument represents a set of overloaded functions (or a
5942 pointer to such), the matching function is selected from the set
5944 else if (TYPE_PTRFN_P (type))
5946 /* If the argument is a template-id, we might not have enough
5947 context information to decay the pointer. */
5948 if (!type_unknown_p (expr_type))
5950 expr = decay_conversion (expr);
5951 if (expr == error_mark_node)
5952 return error_mark_node;
5955 if (cxx_dialect >= cxx0x && integer_zerop (expr))
5956 /* Null pointer values are OK in C++11. */
5957 return perform_qualification_conversions (type, expr);
5959 expr = convert_nontype_argument_function (type, expr);
5960 if (!expr || expr == error_mark_node)
5963 if (TREE_CODE (expr) != ADDR_EXPR)
5965 error ("%qE is not a valid template argument for type %qT", expr, type);
5966 error ("it must be the address of a function with external linkage");
5970 /* [temp.arg.nontype]/5, bullet 5
5972 For a non-type template-parameter of type reference to function, no
5973 conversions apply. If the template-argument represents a set of
5974 overloaded functions, the matching function is selected from the set
5976 else if (TYPE_REFFN_P (type))
5978 if (TREE_CODE (expr) == ADDR_EXPR)
5980 error ("%qE is not a valid template argument for type %qT "
5981 "because it is a pointer", expr, type);
5982 inform (input_location, "try using %qE instead", TREE_OPERAND (expr, 0));
5986 expr = convert_nontype_argument_function (TREE_TYPE (type), expr);
5987 if (!expr || expr == error_mark_node)
5990 expr = build_nop (type, build_address (expr));
5992 /* [temp.arg.nontype]/5, bullet 6
5994 For a non-type template-parameter of type pointer to member function,
5995 no conversions apply. If the template-argument represents a set of
5996 overloaded member functions, the matching member function is selected
5997 from the set (_over.over_). */
5998 else if (TYPE_PTRMEMFUNC_P (type))
6000 expr = instantiate_type (type, expr, tf_none);
6001 if (expr == error_mark_node)
6002 return error_mark_node;
6004 /* [temp.arg.nontype] bullet 1 says the pointer to member
6005 expression must be a pointer-to-member constant. */
6006 if (!check_valid_ptrmem_cst_expr (type, expr, complain))
6007 return error_mark_node;
6009 /* There is no way to disable standard conversions in
6010 resolve_address_of_overloaded_function (called by
6011 instantiate_type). It is possible that the call succeeded by
6012 converting &B::I to &D::I (where B is a base of D), so we need
6013 to reject this conversion here.
6015 Actually, even if there was a way to disable standard conversions,
6016 it would still be better to reject them here so that we can
6017 provide a superior diagnostic. */
6018 if (!same_type_p (TREE_TYPE (expr), type))
6020 error ("%qE is not a valid template argument for type %qT "
6021 "because it is of type %qT", expr, type,
6023 /* If we are just one standard conversion off, explain. */
6024 if (can_convert (type, TREE_TYPE (expr)))
6025 inform (input_location,
6026 "standard conversions are not allowed in this context");
6030 /* [temp.arg.nontype]/5, bullet 7
6032 For a non-type template-parameter of type pointer to data member,
6033 qualification conversions (_conv.qual_) are applied. */
6034 else if (TYPE_PTRMEM_P (type))
6036 /* [temp.arg.nontype] bullet 1 says the pointer to member
6037 expression must be a pointer-to-member constant. */
6038 if (!check_valid_ptrmem_cst_expr (type, expr, complain))
6039 return error_mark_node;
6041 expr = perform_qualification_conversions (type, expr);
6042 if (expr == error_mark_node)
6045 else if (NULLPTR_TYPE_P (type))
6047 if (expr != nullptr_node)
6049 error ("%qE is not a valid template argument for type %qT "
6050 "because it is of type %qT", expr, type, TREE_TYPE (expr));
6055 /* A template non-type parameter must be one of the above. */
6059 /* Sanity check: did we actually convert the argument to the
6061 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6062 (type, TREE_TYPE (expr)));
6066 /* Subroutine of coerce_template_template_parms, which returns 1 if
6067 PARM_PARM and ARG_PARM match using the rule for the template
6068 parameters of template template parameters. Both PARM and ARG are
6069 template parameters; the rest of the arguments are the same as for
6070 coerce_template_template_parms.
6073 coerce_template_template_parm (tree parm,
6075 tsubst_flags_t complain,
6079 if (arg == NULL_TREE || arg == error_mark_node
6080 || parm == NULL_TREE || parm == error_mark_node)
6083 if (TREE_CODE (arg) != TREE_CODE (parm))
6086 switch (TREE_CODE (parm))
6089 /* We encounter instantiations of templates like
6090 template <template <template <class> class> class TT>
6093 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
6094 tree argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
6096 if (!coerce_template_template_parms
6097 (parmparm, argparm, complain, in_decl, outer_args))
6103 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (arg))
6104 && !TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
6105 /* Argument is a parameter pack but parameter is not. */
6110 /* The tsubst call is used to handle cases such as
6112 template <int> class C {};
6113 template <class T, template <T> class TT> class D {};
6116 i.e. the parameter list of TT depends on earlier parameters. */
6117 if (!uses_template_parms (TREE_TYPE (arg))
6119 (tsubst (TREE_TYPE (parm), outer_args, complain, in_decl),
6123 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (arg))
6124 && !TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
6125 /* Argument is a parameter pack but parameter is not. */
6138 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
6139 template template parameters. Both PARM_PARMS and ARG_PARMS are
6140 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
6143 Consider the example:
6144 template <class T> class A;
6145 template<template <class U> class TT> class B;
6147 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
6148 the parameters to A, and OUTER_ARGS contains A. */
6151 coerce_template_template_parms (tree parm_parms,
6153 tsubst_flags_t complain,
6157 int nparms, nargs, i;
6161 gcc_assert (TREE_CODE (parm_parms) == TREE_VEC);
6162 gcc_assert (TREE_CODE (arg_parms) == TREE_VEC);
6164 nparms = TREE_VEC_LENGTH (parm_parms);
6165 nargs = TREE_VEC_LENGTH (arg_parms);
6167 /* Determine whether we have a parameter pack at the end of the
6168 template template parameter's template parameter list. */
6169 if (TREE_VEC_ELT (parm_parms, nparms - 1) != error_mark_node)
6171 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, nparms - 1));
6173 if (parm == error_mark_node)
6176 switch (TREE_CODE (parm))
6180 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
6185 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
6195 && !(variadic_p && nargs >= nparms - 1))
6198 /* Check all of the template parameters except the parameter pack at
6199 the end (if any). */
6200 for (i = 0; i < nparms - variadic_p; ++i)
6202 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node
6203 || TREE_VEC_ELT (arg_parms, i) == error_mark_node)
6206 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
6207 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
6209 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
6217 /* Check each of the template parameters in the template
6218 argument against the template parameter pack at the end of
6219 the template template parameter. */
6220 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node)
6223 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
6225 for (; i < nargs; ++i)
6227 if (TREE_VEC_ELT (arg_parms, i) == error_mark_node)
6230 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
6232 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
6241 /* Verifies that the deduced template arguments (in TARGS) for the
6242 template template parameters (in TPARMS) represent valid bindings,
6243 by comparing the template parameter list of each template argument
6244 to the template parameter list of its corresponding template
6245 template parameter, in accordance with DR150. This
6246 routine can only be called after all template arguments have been
6247 deduced. It will return TRUE if all of the template template
6248 parameter bindings are okay, FALSE otherwise. */
6250 template_template_parm_bindings_ok_p (tree tparms, tree targs)
6252 int i, ntparms = TREE_VEC_LENGTH (tparms);
6255 /* We're dealing with template parms in this process. */
6256 ++processing_template_decl;
6258 targs = INNERMOST_TEMPLATE_ARGS (targs);
6260 for (i = 0; i < ntparms; ++i)
6262 tree tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
6263 tree targ = TREE_VEC_ELT (targs, i);
6265 if (TREE_CODE (tparm) == TEMPLATE_DECL && targ)
6267 tree packed_args = NULL_TREE;
6270 if (ARGUMENT_PACK_P (targ))
6272 /* Look inside the argument pack. */
6273 packed_args = ARGUMENT_PACK_ARGS (targ);
6274 len = TREE_VEC_LENGTH (packed_args);
6277 for (idx = 0; idx < len; ++idx)
6279 tree targ_parms = NULL_TREE;
6282 /* Extract the next argument from the argument
6284 targ = TREE_VEC_ELT (packed_args, idx);
6286 if (PACK_EXPANSION_P (targ))
6287 /* Look at the pattern of the pack expansion. */
6288 targ = PACK_EXPANSION_PATTERN (targ);
6290 /* Extract the template parameters from the template
6292 if (TREE_CODE (targ) == TEMPLATE_DECL)
6293 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (targ);
6294 else if (TREE_CODE (targ) == TEMPLATE_TEMPLATE_PARM)
6295 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (TYPE_NAME (targ));
6297 /* Verify that we can coerce the template template
6298 parameters from the template argument to the template
6299 parameter. This requires an exact match. */
6301 && !coerce_template_template_parms
6302 (DECL_INNERMOST_TEMPLATE_PARMS (tparm),
6317 --processing_template_decl;
6321 /* Since type attributes aren't mangled, we need to strip them from
6322 template type arguments. */
6325 canonicalize_type_argument (tree arg, tsubst_flags_t complain)
6328 if (!arg || arg == error_mark_node || arg == TYPE_CANONICAL (arg))
6330 mv = TYPE_MAIN_VARIANT (arg);
6331 arg = strip_typedefs (arg);
6332 if (TYPE_ALIGN (arg) != TYPE_ALIGN (mv)
6333 || TYPE_ATTRIBUTES (arg) != TYPE_ATTRIBUTES (mv))
6335 if (complain & tf_warning)
6336 warning (0, "ignoring attributes on template argument %qT", arg);
6337 arg = build_aligned_type (arg, TYPE_ALIGN (mv));
6338 arg = cp_build_type_attribute_variant (arg, TYPE_ATTRIBUTES (mv));
6343 /* Convert the indicated template ARG as necessary to match the
6344 indicated template PARM. Returns the converted ARG, or
6345 error_mark_node if the conversion was unsuccessful. Error and
6346 warning messages are issued under control of COMPLAIN. This
6347 conversion is for the Ith parameter in the parameter list. ARGS is
6348 the full set of template arguments deduced so far. */
6351 convert_template_argument (tree parm,
6354 tsubst_flags_t complain,
6360 int is_type, requires_type, is_tmpl_type, requires_tmpl_type;
6362 if (TREE_CODE (arg) == TREE_LIST
6363 && TREE_CODE (TREE_VALUE (arg)) == OFFSET_REF)
6365 /* The template argument was the name of some
6366 member function. That's usually
6367 invalid, but static members are OK. In any
6368 case, grab the underlying fields/functions
6369 and issue an error later if required. */
6370 orig_arg = TREE_VALUE (arg);
6371 TREE_TYPE (arg) = unknown_type_node;
6376 requires_tmpl_type = TREE_CODE (parm) == TEMPLATE_DECL;
6377 requires_type = (TREE_CODE (parm) == TYPE_DECL
6378 || requires_tmpl_type);
6380 /* When determining whether an argument pack expansion is a template,
6381 look at the pattern. */
6382 if (TREE_CODE (arg) == TYPE_PACK_EXPANSION)
6383 arg = PACK_EXPANSION_PATTERN (arg);
6385 /* Deal with an injected-class-name used as a template template arg. */
6386 if (requires_tmpl_type && CLASS_TYPE_P (arg))
6388 tree t = maybe_get_template_decl_from_type_decl (TYPE_NAME (arg));
6389 if (TREE_CODE (t) == TEMPLATE_DECL)
6391 if (cxx_dialect >= cxx0x)
6392 /* OK under DR 1004. */;
6393 else if (complain & tf_warning_or_error)
6394 pedwarn (input_location, OPT_pedantic, "injected-class-name %qD"
6395 " used as template template argument", TYPE_NAME (arg));
6396 else if (flag_pedantic_errors)
6404 ((TREE_CODE (arg) == TEMPLATE_DECL
6405 && TREE_CODE (DECL_TEMPLATE_RESULT (arg)) == TYPE_DECL)
6406 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
6407 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE);
6410 && (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
6411 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE))
6412 arg = TYPE_STUB_DECL (arg);
6414 is_type = TYPE_P (arg) || is_tmpl_type;
6416 if (requires_type && ! is_type && TREE_CODE (arg) == SCOPE_REF
6417 && TREE_CODE (TREE_OPERAND (arg, 0)) == TEMPLATE_TYPE_PARM)
6419 permerror (input_location, "to refer to a type member of a template parameter, "
6420 "use %<typename %E%>", orig_arg);
6422 orig_arg = make_typename_type (TREE_OPERAND (arg, 0),
6423 TREE_OPERAND (arg, 1),
6425 complain & tf_error);
6429 if (is_type != requires_type)
6433 if (complain & tf_error)
6435 error ("type/value mismatch at argument %d in template "
6436 "parameter list for %qD",
6439 error (" expected a constant of type %qT, got %qT",
6441 (DECL_P (arg) ? DECL_NAME (arg) : orig_arg));
6442 else if (requires_tmpl_type)
6443 error (" expected a class template, got %qE", orig_arg);
6445 error (" expected a type, got %qE", orig_arg);
6448 return error_mark_node;
6450 if (is_tmpl_type ^ requires_tmpl_type)
6452 if (in_decl && (complain & tf_error))
6454 error ("type/value mismatch at argument %d in template "
6455 "parameter list for %qD",
6458 error (" expected a type, got %qT", DECL_NAME (arg));
6460 error (" expected a class template, got %qT", orig_arg);
6462 return error_mark_node;
6467 if (requires_tmpl_type)
6469 if (TREE_CODE (TREE_TYPE (arg)) == UNBOUND_CLASS_TEMPLATE)
6470 /* The number of argument required is not known yet.
6471 Just accept it for now. */
6472 val = TREE_TYPE (arg);
6475 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
6478 argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
6480 if (coerce_template_template_parms (parmparm, argparm,
6486 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6488 if (val != error_mark_node)
6490 if (DECL_TEMPLATE_TEMPLATE_PARM_P (val))
6491 val = TREE_TYPE (val);
6492 if (TREE_CODE (orig_arg) == TYPE_PACK_EXPANSION)
6493 val = make_pack_expansion (val);
6498 if (in_decl && (complain & tf_error))
6500 error ("type/value mismatch at argument %d in "
6501 "template parameter list for %qD",
6503 error (" expected a template of type %qD, got %qT",
6507 val = error_mark_node;
6513 /* We only form one instance of each template specialization.
6514 Therefore, if we use a non-canonical variant (i.e., a
6515 typedef), any future messages referring to the type will use
6516 the typedef, which is confusing if those future uses do not
6517 themselves also use the typedef. */
6519 val = canonicalize_type_argument (val, complain);
6523 tree t = tsubst (TREE_TYPE (parm), args, complain, in_decl);
6525 if (invalid_nontype_parm_type_p (t, complain))
6526 return error_mark_node;
6528 if (template_parameter_pack_p (parm) && ARGUMENT_PACK_P (orig_arg))
6530 if (same_type_p (t, TREE_TYPE (orig_arg)))
6534 /* Not sure if this is reachable, but it doesn't hurt
6536 error ("type mismatch in nontype parameter pack");
6537 val = error_mark_node;
6540 else if (!uses_template_parms (orig_arg) && !uses_template_parms (t))
6541 /* We used to call digest_init here. However, digest_init
6542 will report errors, which we don't want when complain
6543 is zero. More importantly, digest_init will try too
6544 hard to convert things: for example, `0' should not be
6545 converted to pointer type at this point according to
6546 the standard. Accepting this is not merely an
6547 extension, since deciding whether or not these
6548 conversions can occur is part of determining which
6549 function template to call, or whether a given explicit
6550 argument specification is valid. */
6551 val = convert_nontype_argument (t, orig_arg, complain);
6555 if (val == NULL_TREE)
6556 val = error_mark_node;
6557 else if (val == error_mark_node && (complain & tf_error))
6558 error ("could not convert template argument %qE to %qT", orig_arg, t);
6560 if (TREE_CODE (val) == SCOPE_REF)
6562 /* Strip typedefs from the SCOPE_REF. */
6563 tree type = canonicalize_type_argument (TREE_TYPE (val), complain);
6564 tree scope = canonicalize_type_argument (TREE_OPERAND (val, 0),
6566 val = build_qualified_name (type, scope, TREE_OPERAND (val, 1),
6567 QUALIFIED_NAME_IS_TEMPLATE (val));
6574 /* Coerces the remaining template arguments in INNER_ARGS (from
6575 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6576 Returns the coerced argument pack. PARM_IDX is the position of this
6577 parameter in the template parameter list. ARGS is the original
6578 template argument list. */
6580 coerce_template_parameter_pack (tree parms,
6588 tsubst_flags_t complain)
6590 tree parm = TREE_VEC_ELT (parms, parm_idx);
6591 int nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
6594 tree packed_types = NULL_TREE;
6596 if (arg_idx > nargs)
6599 packed_args = make_tree_vec (nargs - arg_idx);
6601 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL
6602 && uses_parameter_packs (TREE_TYPE (TREE_VALUE (parm))))
6604 /* When the template parameter is a non-type template
6605 parameter pack whose type uses parameter packs, we need
6606 to look at each of the template arguments
6607 separately. Build a vector of the types for these
6608 non-type template parameters in PACKED_TYPES. */
6610 = make_pack_expansion (TREE_TYPE (TREE_VALUE (parm)));
6611 packed_types = tsubst_pack_expansion (expansion, args,
6614 if (packed_types == error_mark_node)
6615 return error_mark_node;
6617 /* Check that we have the right number of arguments. */
6619 && !PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx))
6620 && nargs - arg_idx != TREE_VEC_LENGTH (packed_types))
6623 = TREE_VEC_LENGTH (parms) - 1 + TREE_VEC_LENGTH (packed_types);
6624 error ("wrong number of template arguments (%d, should be %d)",
6625 nargs, needed_parms);
6626 return error_mark_node;
6629 /* If we aren't able to check the actual arguments now
6630 (because they haven't been expanded yet), we can at least
6631 verify that all of the types used for the non-type
6632 template parameter pack are, in fact, valid for non-type
6633 template parameters. */
6635 && PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx)))
6637 int j, len = TREE_VEC_LENGTH (packed_types);
6638 for (j = 0; j < len; ++j)
6640 tree t = TREE_VEC_ELT (packed_types, j);
6641 if (invalid_nontype_parm_type_p (t, complain))
6642 return error_mark_node;
6647 /* Convert the remaining arguments, which will be a part of the
6648 parameter pack "parm". */
6649 for (; arg_idx < nargs; ++arg_idx)
6651 tree arg = TREE_VEC_ELT (inner_args, arg_idx);
6652 tree actual_parm = TREE_VALUE (parm);
6654 if (packed_types && !PACK_EXPANSION_P (arg))
6656 /* When we have a vector of types (corresponding to the
6657 non-type template parameter pack that uses parameter
6658 packs in its type, as mention above), and the
6659 argument is not an expansion (which expands to a
6660 currently unknown number of arguments), clone the
6661 parm and give it the next type in PACKED_TYPES. */
6662 actual_parm = copy_node (actual_parm);
6663 TREE_TYPE (actual_parm) =
6664 TREE_VEC_ELT (packed_types, arg_idx - parm_idx);
6667 if (arg != error_mark_node)
6668 arg = convert_template_argument (actual_parm,
6669 arg, new_args, complain, parm_idx,
6671 if (arg == error_mark_node)
6673 TREE_VEC_ELT (packed_args, arg_idx - parm_idx) = arg;
6676 if (TREE_CODE (TREE_VALUE (parm)) == TYPE_DECL
6677 || TREE_CODE (TREE_VALUE (parm)) == TEMPLATE_DECL)
6678 argument_pack = cxx_make_type (TYPE_ARGUMENT_PACK);
6681 argument_pack = make_node (NONTYPE_ARGUMENT_PACK);
6682 TREE_TYPE (argument_pack)
6683 = tsubst (TREE_TYPE (TREE_VALUE (parm)), new_args, complain, in_decl);
6684 TREE_CONSTANT (argument_pack) = 1;
6687 SET_ARGUMENT_PACK_ARGS (argument_pack, packed_args);
6688 #ifdef ENABLE_CHECKING
6689 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (packed_args,
6690 TREE_VEC_LENGTH (packed_args));
6692 return argument_pack;
6695 /* Convert all template arguments to their appropriate types, and
6696 return a vector containing the innermost resulting template
6697 arguments. If any error occurs, return error_mark_node. Error and
6698 warning messages are issued under control of COMPLAIN.
6700 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6701 for arguments not specified in ARGS. Otherwise, if
6702 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6703 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6704 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6708 coerce_template_parms (tree parms,
6711 tsubst_flags_t complain,
6712 bool require_all_args,
6713 bool use_default_args)
6715 int nparms, nargs, parm_idx, arg_idx, lost = 0;
6718 tree new_inner_args;
6719 int saved_unevaluated_operand;
6720 int saved_inhibit_evaluation_warnings;
6722 /* When used as a boolean value, indicates whether this is a
6723 variadic template parameter list. Since it's an int, we can also
6724 subtract it from nparms to get the number of non-variadic
6727 int post_variadic_parms = 0;
6729 if (args == error_mark_node)
6730 return error_mark_node;
6732 nparms = TREE_VEC_LENGTH (parms);
6734 /* Determine if there are any parameter packs. */
6735 for (parm_idx = 0; parm_idx < nparms; ++parm_idx)
6737 tree tparm = TREE_VALUE (TREE_VEC_ELT (parms, parm_idx));
6739 ++post_variadic_parms;
6740 if (template_parameter_pack_p (tparm))
6744 inner_args = INNERMOST_TEMPLATE_ARGS (args);
6745 /* If there are no parameters that follow a parameter pack, we need to
6746 expand any argument packs so that we can deduce a parameter pack from
6747 some non-packed args followed by an argument pack, as in variadic85.C.
6748 If there are such parameters, we need to leave argument packs intact
6749 so the arguments are assigned properly. This can happen when dealing
6750 with a nested class inside a partial specialization of a class
6751 template, as in variadic92.C, or when deducing a template parameter pack
6752 from a sub-declarator, as in variadic114.C. */
6753 if (!post_variadic_parms)
6754 inner_args = expand_template_argument_pack (inner_args);
6756 nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
6757 if ((nargs > nparms && !variadic_p)
6758 || (nargs < nparms - variadic_p
6760 && (!use_default_args
6761 || (TREE_VEC_ELT (parms, nargs) != error_mark_node
6762 && !TREE_PURPOSE (TREE_VEC_ELT (parms, nargs))))))
6764 if (complain & tf_error)
6768 nparms -= variadic_p;
6769 error ("wrong number of template arguments "
6770 "(%d, should be %d or more)", nargs, nparms);
6773 error ("wrong number of template arguments "
6774 "(%d, should be %d)", nargs, nparms);
6777 error ("provided for %q+D", in_decl);
6780 return error_mark_node;
6783 /* We need to evaluate the template arguments, even though this
6784 template-id may be nested within a "sizeof". */
6785 saved_unevaluated_operand = cp_unevaluated_operand;
6786 cp_unevaluated_operand = 0;
6787 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
6788 c_inhibit_evaluation_warnings = 0;
6789 new_inner_args = make_tree_vec (nparms);
6790 new_args = add_outermost_template_args (args, new_inner_args);
6791 for (parm_idx = 0, arg_idx = 0; parm_idx < nparms; parm_idx++, arg_idx++)
6796 /* Get the Ith template parameter. */
6797 parm = TREE_VEC_ELT (parms, parm_idx);
6799 if (parm == error_mark_node)
6801 TREE_VEC_ELT (new_inner_args, arg_idx) = error_mark_node;
6805 /* Calculate the next argument. */
6806 if (arg_idx < nargs)
6807 arg = TREE_VEC_ELT (inner_args, arg_idx);
6811 if (template_parameter_pack_p (TREE_VALUE (parm))
6812 && !(arg && ARGUMENT_PACK_P (arg)))
6814 /* All remaining arguments will be placed in the
6815 template parameter pack PARM. */
6816 arg = coerce_template_parameter_pack (parms, parm_idx, args,
6817 inner_args, arg_idx,
6821 /* Store this argument. */
6822 if (arg == error_mark_node)
6824 TREE_VEC_ELT (new_inner_args, parm_idx) = arg;
6826 /* We are done with all of the arguments. */
6833 if (PACK_EXPANSION_P (arg))
6835 /* We don't know how many args we have yet, just
6836 use the unconverted ones for now. */
6837 new_inner_args = args;
6841 else if (require_all_args)
6843 /* There must be a default arg in this case. */
6844 arg = tsubst_template_arg (TREE_PURPOSE (parm), new_args,
6846 /* The position of the first default template argument,
6847 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6849 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args))
6850 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args, arg_idx);
6855 if (arg == error_mark_node)
6857 if (complain & tf_error)
6858 error ("template argument %d is invalid", arg_idx + 1);
6861 /* This only occurs if there was an error in the template
6862 parameter list itself (which we would already have
6863 reported) that we are trying to recover from, e.g., a class
6864 template with a parameter list such as
6865 template<typename..., typename>. */
6868 arg = convert_template_argument (TREE_VALUE (parm),
6869 arg, new_args, complain,
6872 if (arg == error_mark_node)
6874 TREE_VEC_ELT (new_inner_args, arg_idx) = arg;
6876 cp_unevaluated_operand = saved_unevaluated_operand;
6877 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
6880 return error_mark_node;
6882 #ifdef ENABLE_CHECKING
6883 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args))
6884 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args,
6885 TREE_VEC_LENGTH (new_inner_args));
6888 return new_inner_args;
6891 /* Returns 1 if template args OT and NT are equivalent. */
6894 template_args_equal (tree ot, tree nt)
6898 if (nt == NULL_TREE || ot == NULL_TREE)
6901 if (TREE_CODE (nt) == TREE_VEC)
6902 /* For member templates */
6903 return TREE_CODE (ot) == TREE_VEC && comp_template_args (ot, nt);
6904 else if (PACK_EXPANSION_P (ot))
6905 return PACK_EXPANSION_P (nt)
6906 && template_args_equal (PACK_EXPANSION_PATTERN (ot),
6907 PACK_EXPANSION_PATTERN (nt));
6908 else if (ARGUMENT_PACK_P (ot))
6913 if (!ARGUMENT_PACK_P (nt))
6916 opack = ARGUMENT_PACK_ARGS (ot);
6917 npack = ARGUMENT_PACK_ARGS (nt);
6918 len = TREE_VEC_LENGTH (opack);
6919 if (TREE_VEC_LENGTH (npack) != len)
6921 for (i = 0; i < len; ++i)
6922 if (!template_args_equal (TREE_VEC_ELT (opack, i),
6923 TREE_VEC_ELT (npack, i)))
6927 else if (ot && TREE_CODE (ot) == ARGUMENT_PACK_SELECT)
6929 /* We get here probably because we are in the middle of substituting
6930 into the pattern of a pack expansion. In that case the
6931 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
6932 interested in. So we want to use the initial pack argument for
6934 ot = ARGUMENT_PACK_SELECT_FROM_PACK (ot);
6935 if (nt && TREE_CODE (nt) == ARGUMENT_PACK_SELECT)
6936 nt = ARGUMENT_PACK_SELECT_FROM_PACK (nt);
6937 return template_args_equal (ot, nt);
6939 else if (TYPE_P (nt))
6940 return TYPE_P (ot) && same_type_p (ot, nt);
6941 else if (TREE_CODE (ot) == TREE_VEC || TYPE_P (ot))
6944 return cp_tree_equal (ot, nt);
6947 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
6948 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
6949 NEWARG_PTR with the offending arguments if they are non-NULL. */
6952 comp_template_args_with_info (tree oldargs, tree newargs,
6953 tree *oldarg_ptr, tree *newarg_ptr)
6957 if (TREE_VEC_LENGTH (oldargs) != TREE_VEC_LENGTH (newargs))
6960 for (i = 0; i < TREE_VEC_LENGTH (oldargs); ++i)
6962 tree nt = TREE_VEC_ELT (newargs, i);
6963 tree ot = TREE_VEC_ELT (oldargs, i);
6965 if (! template_args_equal (ot, nt))
6967 if (oldarg_ptr != NULL)
6969 if (newarg_ptr != NULL)
6977 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
6978 of template arguments. Returns 0 otherwise. */
6981 comp_template_args (tree oldargs, tree newargs)
6983 return comp_template_args_with_info (oldargs, newargs, NULL, NULL);
6987 add_pending_template (tree d)
6989 tree ti = (TYPE_P (d)
6990 ? CLASSTYPE_TEMPLATE_INFO (d)
6991 : DECL_TEMPLATE_INFO (d));
6992 struct pending_template *pt;
6995 if (TI_PENDING_TEMPLATE_FLAG (ti))
6998 /* We are called both from instantiate_decl, where we've already had a
6999 tinst_level pushed, and instantiate_template, where we haven't.
7001 level = !current_tinst_level || current_tinst_level->decl != d;
7004 push_tinst_level (d);
7006 pt = ggc_alloc_pending_template ();
7008 pt->tinst = current_tinst_level;
7009 if (last_pending_template)
7010 last_pending_template->next = pt;
7012 pending_templates = pt;
7014 last_pending_template = pt;
7016 TI_PENDING_TEMPLATE_FLAG (ti) = 1;
7023 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
7024 ARGLIST. Valid choices for FNS are given in the cp-tree.def
7025 documentation for TEMPLATE_ID_EXPR. */
7028 lookup_template_function (tree fns, tree arglist)
7032 if (fns == error_mark_node || arglist == error_mark_node)
7033 return error_mark_node;
7035 gcc_assert (!arglist || TREE_CODE (arglist) == TREE_VEC);
7037 if (!is_overloaded_fn (fns) && TREE_CODE (fns) != IDENTIFIER_NODE)
7039 error ("%q#D is not a function template", fns);
7040 return error_mark_node;
7043 if (BASELINK_P (fns))
7045 BASELINK_FUNCTIONS (fns) = build2 (TEMPLATE_ID_EXPR,
7047 BASELINK_FUNCTIONS (fns),
7052 type = TREE_TYPE (fns);
7053 if (TREE_CODE (fns) == OVERLOAD || !type)
7054 type = unknown_type_node;
7056 return build2 (TEMPLATE_ID_EXPR, type, fns, arglist);
7059 /* Within the scope of a template class S<T>, the name S gets bound
7060 (in build_self_reference) to a TYPE_DECL for the class, not a
7061 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
7062 or one of its enclosing classes, and that type is a template,
7063 return the associated TEMPLATE_DECL. Otherwise, the original
7066 Also handle the case when DECL is a TREE_LIST of ambiguous
7067 injected-class-names from different bases. */
7070 maybe_get_template_decl_from_type_decl (tree decl)
7072 if (decl == NULL_TREE)
7075 /* DR 176: A lookup that finds an injected-class-name (10.2
7076 [class.member.lookup]) can result in an ambiguity in certain cases
7077 (for example, if it is found in more than one base class). If all of
7078 the injected-class-names that are found refer to specializations of
7079 the same class template, and if the name is followed by a
7080 template-argument-list, the reference refers to the class template
7081 itself and not a specialization thereof, and is not ambiguous. */
7082 if (TREE_CODE (decl) == TREE_LIST)
7084 tree t, tmpl = NULL_TREE;
7085 for (t = decl; t; t = TREE_CHAIN (t))
7087 tree elt = maybe_get_template_decl_from_type_decl (TREE_VALUE (t));
7090 else if (tmpl != elt)
7093 if (tmpl && t == NULL_TREE)
7099 return (decl != NULL_TREE
7100 && DECL_SELF_REFERENCE_P (decl)
7101 && CLASSTYPE_TEMPLATE_INFO (TREE_TYPE (decl)))
7102 ? CLASSTYPE_TI_TEMPLATE (TREE_TYPE (decl)) : decl;
7105 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
7106 parameters, find the desired type.
7108 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
7110 IN_DECL, if non-NULL, is the template declaration we are trying to
7113 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
7114 the class we are looking up.
7116 Issue error and warning messages under control of COMPLAIN.
7118 If the template class is really a local class in a template
7119 function, then the FUNCTION_CONTEXT is the function in which it is
7122 ??? Note that this function is currently called *twice* for each
7123 template-id: the first time from the parser, while creating the
7124 incomplete type (finish_template_type), and the second type during the
7125 real instantiation (instantiate_template_class). This is surely something
7126 that we want to avoid. It also causes some problems with argument
7127 coercion (see convert_nontype_argument for more information on this). */
7130 lookup_template_class_1 (tree d1, tree arglist, tree in_decl, tree context,
7131 int entering_scope, tsubst_flags_t complain)
7133 tree templ = NULL_TREE, parmlist;
7140 if (TREE_CODE (d1) == IDENTIFIER_NODE)
7142 tree value = innermost_non_namespace_value (d1);
7143 if (value && DECL_TEMPLATE_TEMPLATE_PARM_P (value))
7148 push_decl_namespace (context);
7149 templ = lookup_name (d1);
7150 templ = maybe_get_template_decl_from_type_decl (templ);
7152 pop_decl_namespace ();
7155 context = DECL_CONTEXT (templ);
7157 else if (TREE_CODE (d1) == TYPE_DECL && MAYBE_CLASS_TYPE_P (TREE_TYPE (d1)))
7159 tree type = TREE_TYPE (d1);
7161 /* If we are declaring a constructor, say A<T>::A<T>, we will get
7162 an implicit typename for the second A. Deal with it. */
7163 if (TREE_CODE (type) == TYPENAME_TYPE && TREE_TYPE (type))
7164 type = TREE_TYPE (type);
7166 if (CLASSTYPE_TEMPLATE_INFO (type))
7168 templ = CLASSTYPE_TI_TEMPLATE (type);
7169 d1 = DECL_NAME (templ);
7172 else if (TREE_CODE (d1) == ENUMERAL_TYPE
7173 || (TYPE_P (d1) && MAYBE_CLASS_TYPE_P (d1)))
7175 templ = TYPE_TI_TEMPLATE (d1);
7176 d1 = DECL_NAME (templ);
7178 else if (TREE_CODE (d1) == TEMPLATE_DECL
7179 && DECL_TEMPLATE_RESULT (d1)
7180 && TREE_CODE (DECL_TEMPLATE_RESULT (d1)) == TYPE_DECL)
7183 d1 = DECL_NAME (templ);
7184 context = DECL_CONTEXT (templ);
7187 /* Issue an error message if we didn't find a template. */
7190 if (complain & tf_error)
7191 error ("%qT is not a template", d1);
7192 return error_mark_node;
7195 if (TREE_CODE (templ) != TEMPLATE_DECL
7196 /* Make sure it's a user visible template, if it was named by
7198 || ((complain & tf_user) && !DECL_TEMPLATE_PARM_P (templ)
7199 && !PRIMARY_TEMPLATE_P (templ)))
7201 if (complain & tf_error)
7203 error ("non-template type %qT used as a template", d1);
7205 error ("for template declaration %q+D", in_decl);
7207 return error_mark_node;
7210 complain &= ~tf_user;
7212 if (DECL_TEMPLATE_TEMPLATE_PARM_P (templ))
7214 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
7215 template arguments */
7221 parmlist = DECL_INNERMOST_TEMPLATE_PARMS (templ);
7223 /* Consider an example where a template template parameter declared as
7225 template <class T, class U = std::allocator<T> > class TT
7227 The template parameter level of T and U are one level larger than
7228 of TT. To proper process the default argument of U, say when an
7229 instantiation `TT<int>' is seen, we need to build the full
7230 arguments containing {int} as the innermost level. Outer levels,
7231 available when not appearing as default template argument, can be
7232 obtained from the arguments of the enclosing template.
7234 Suppose that TT is later substituted with std::vector. The above
7235 instantiation is `TT<int, std::allocator<T> >' with TT at
7236 level 1, and T at level 2, while the template arguments at level 1
7237 becomes {std::vector} and the inner level 2 is {int}. */
7239 outer = DECL_CONTEXT (templ);
7241 outer = TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (outer)));
7242 else if (current_template_parms)
7243 /* This is an argument of the current template, so we haven't set
7244 DECL_CONTEXT yet. */
7245 outer = current_template_args ();
7248 arglist = add_to_template_args (outer, arglist);
7250 arglist2 = coerce_template_parms (parmlist, arglist, templ,
7252 /*require_all_args=*/true,
7253 /*use_default_args=*/true);
7254 if (arglist2 == error_mark_node
7255 || (!uses_template_parms (arglist2)
7256 && check_instantiated_args (templ, arglist2, complain)))
7257 return error_mark_node;
7259 parm = bind_template_template_parm (TREE_TYPE (templ), arglist2);
7264 tree template_type = TREE_TYPE (templ);
7267 tree found = NULL_TREE;
7270 int is_dependent_type;
7271 int use_partial_inst_tmpl = false;
7273 gen_tmpl = most_general_template (templ);
7274 parmlist = DECL_TEMPLATE_PARMS (gen_tmpl);
7275 parm_depth = TMPL_PARMS_DEPTH (parmlist);
7276 arg_depth = TMPL_ARGS_DEPTH (arglist);
7278 if (arg_depth == 1 && parm_depth > 1)
7280 /* We've been given an incomplete set of template arguments.
7283 template <class T> struct S1 {
7284 template <class U> struct S2 {};
7285 template <class U> struct S2<U*> {};
7288 we will be called with an ARGLIST of `U*', but the
7289 TEMPLATE will be `template <class T> template
7290 <class U> struct S1<T>::S2'. We must fill in the missing
7293 = add_outermost_template_args (TYPE_TI_ARGS (TREE_TYPE (templ)),
7295 arg_depth = TMPL_ARGS_DEPTH (arglist);
7298 /* Now we should have enough arguments. */
7299 gcc_assert (parm_depth == arg_depth);
7301 /* From here on, we're only interested in the most general
7304 /* Calculate the BOUND_ARGS. These will be the args that are
7305 actually tsubst'd into the definition to create the
7309 /* We have multiple levels of arguments to coerce, at once. */
7311 int saved_depth = TMPL_ARGS_DEPTH (arglist);
7313 tree bound_args = make_tree_vec (parm_depth);
7315 for (i = saved_depth,
7316 t = DECL_TEMPLATE_PARMS (gen_tmpl);
7317 i > 0 && t != NULL_TREE;
7318 --i, t = TREE_CHAIN (t))
7321 if (i == saved_depth)
7322 a = coerce_template_parms (TREE_VALUE (t),
7325 /*require_all_args=*/true,
7326 /*use_default_args=*/true);
7328 /* Outer levels should have already been coerced. */
7329 a = TMPL_ARGS_LEVEL (arglist, i);
7331 /* Don't process further if one of the levels fails. */
7332 if (a == error_mark_node)
7334 /* Restore the ARGLIST to its full size. */
7335 TREE_VEC_LENGTH (arglist) = saved_depth;
7336 return error_mark_node;
7339 SET_TMPL_ARGS_LEVEL (bound_args, i, a);
7341 /* We temporarily reduce the length of the ARGLIST so
7342 that coerce_template_parms will see only the arguments
7343 corresponding to the template parameters it is
7345 TREE_VEC_LENGTH (arglist)--;
7348 /* Restore the ARGLIST to its full size. */
7349 TREE_VEC_LENGTH (arglist) = saved_depth;
7351 arglist = bound_args;
7355 = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parmlist),
7356 INNERMOST_TEMPLATE_ARGS (arglist),
7359 /*require_all_args=*/true,
7360 /*use_default_args=*/true);
7362 if (arglist == error_mark_node)
7363 /* We were unable to bind the arguments. */
7364 return error_mark_node;
7366 /* In the scope of a template class, explicit references to the
7367 template class refer to the type of the template, not any
7368 instantiation of it. For example, in:
7370 template <class T> class C { void f(C<T>); }
7372 the `C<T>' is just the same as `C'. Outside of the
7373 class, however, such a reference is an instantiation. */
7375 || !PRIMARY_TEMPLATE_P (gen_tmpl)
7376 || currently_open_class (template_type))
7377 /* comp_template_args is expensive, check it last. */
7378 && comp_template_args (TYPE_TI_ARGS (template_type),
7380 return template_type;
7382 /* If we already have this specialization, return it. */
7383 elt.tmpl = gen_tmpl;
7385 hash = hash_specialization (&elt);
7386 entry = (spec_entry *) htab_find_with_hash (type_specializations,
7392 is_dependent_type = uses_template_parms (arglist);
7394 /* If the deduced arguments are invalid, then the binding
7396 if (!is_dependent_type
7397 && check_instantiated_args (gen_tmpl,
7398 INNERMOST_TEMPLATE_ARGS (arglist),
7400 return error_mark_node;
7402 if (!is_dependent_type
7403 && !PRIMARY_TEMPLATE_P (gen_tmpl)
7404 && !LAMBDA_TYPE_P (TREE_TYPE (gen_tmpl))
7405 && TREE_CODE (CP_DECL_CONTEXT (gen_tmpl)) == NAMESPACE_DECL)
7407 found = xref_tag_from_type (TREE_TYPE (gen_tmpl),
7408 DECL_NAME (gen_tmpl),
7409 /*tag_scope=*/ts_global);
7413 context = tsubst (DECL_CONTEXT (gen_tmpl), arglist,
7416 context = global_namespace;
7418 /* Create the type. */
7419 if (TREE_CODE (template_type) == ENUMERAL_TYPE)
7421 if (!is_dependent_type)
7423 set_current_access_from_decl (TYPE_NAME (template_type));
7424 t = start_enum (TYPE_IDENTIFIER (template_type), NULL_TREE,
7425 tsubst (ENUM_UNDERLYING_TYPE (template_type),
7426 arglist, complain, in_decl),
7427 SCOPED_ENUM_P (template_type), NULL);
7431 /* We don't want to call start_enum for this type, since
7432 the values for the enumeration constants may involve
7433 template parameters. And, no one should be interested
7434 in the enumeration constants for such a type. */
7435 t = cxx_make_type (ENUMERAL_TYPE);
7436 SET_SCOPED_ENUM_P (t, SCOPED_ENUM_P (template_type));
7438 SET_OPAQUE_ENUM_P (t, OPAQUE_ENUM_P (template_type));
7439 ENUM_FIXED_UNDERLYING_TYPE_P (t)
7440 = ENUM_FIXED_UNDERLYING_TYPE_P (template_type);
7442 else if (DECL_ALIAS_TEMPLATE_P (gen_tmpl))
7444 /* The user referred to a specialization of an alias
7445 template represented by GEN_TMPL.
7447 [temp.alias]/2 says:
7449 When a template-id refers to the specialization of an
7450 alias template, it is equivalent to the associated
7451 type obtained by substitution of its
7452 template-arguments for the template-parameters in the
7453 type-id of the alias template. */
7455 t = tsubst (TREE_TYPE (gen_tmpl), arglist, complain, in_decl);
7456 /* Note that the call above (by indirectly calling
7457 register_specialization in tsubst_decl) registers the
7458 TYPE_DECL representing the specialization of the alias
7459 template. So next time someone substitutes ARGLIST for
7460 the template parms into the alias template (GEN_TMPL),
7461 she'll get that TYPE_DECL back. */
7463 if (t == error_mark_node)
7466 else if (CLASS_TYPE_P (template_type))
7468 t = make_class_type (TREE_CODE (template_type));
7469 CLASSTYPE_DECLARED_CLASS (t)
7470 = CLASSTYPE_DECLARED_CLASS (template_type);
7471 SET_CLASSTYPE_IMPLICIT_INSTANTIATION (t);
7472 TYPE_FOR_JAVA (t) = TYPE_FOR_JAVA (template_type);
7474 /* A local class. Make sure the decl gets registered properly. */
7475 if (context == current_function_decl)
7476 pushtag (DECL_NAME (gen_tmpl), t, /*tag_scope=*/ts_current);
7478 if (comp_template_args (CLASSTYPE_TI_ARGS (template_type), arglist))
7479 /* This instantiation is another name for the primary
7480 template type. Set the TYPE_CANONICAL field
7482 TYPE_CANONICAL (t) = template_type;
7483 else if (any_template_arguments_need_structural_equality_p (arglist))
7484 /* Some of the template arguments require structural
7485 equality testing, so this template class requires
7486 structural equality testing. */
7487 SET_TYPE_STRUCTURAL_EQUALITY (t);
7492 /* If we called start_enum or pushtag above, this information
7493 will already be set up. */
7496 TYPE_CONTEXT (t) = FROB_CONTEXT (context);
7498 type_decl = create_implicit_typedef (DECL_NAME (gen_tmpl), t);
7499 DECL_CONTEXT (type_decl) = TYPE_CONTEXT (t);
7500 DECL_SOURCE_LOCATION (type_decl)
7501 = DECL_SOURCE_LOCATION (TYPE_STUB_DECL (template_type));
7504 type_decl = TYPE_NAME (t);
7506 if (CLASS_TYPE_P (template_type))
7508 TREE_PRIVATE (type_decl)
7509 = TREE_PRIVATE (TYPE_STUB_DECL (template_type));
7510 TREE_PROTECTED (type_decl)
7511 = TREE_PROTECTED (TYPE_STUB_DECL (template_type));
7512 if (CLASSTYPE_VISIBILITY_SPECIFIED (template_type))
7514 DECL_VISIBILITY_SPECIFIED (type_decl) = 1;
7515 DECL_VISIBILITY (type_decl) = CLASSTYPE_VISIBILITY (template_type);
7519 /* Let's consider the explicit specialization of a member
7520 of a class template specialization that is implicitely instantiated,
7525 template<class U> struct M {}; //#0
7530 struct S<int>::M<char> //#1
7534 [temp.expl.spec]/4 says this is valid.
7536 In this case, when we write:
7539 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7542 When we encounter #1, we want to store the partial instantiation
7543 of M (template<class T> S<int>::M<T>) in it's CLASSTYPE_TI_TEMPLATE.
7545 For all cases other than this "explicit specialization of member of a
7546 class template", we just want to store the most general template into
7547 the CLASSTYPE_TI_TEMPLATE of M.
7549 This case of "explicit specialization of member of a class template"
7551 1/ the enclosing class is an instantiation of, and therefore not
7552 the same as, the context of the most general template, and
7553 2/ we aren't looking at the partial instantiation itself, i.e.
7554 the innermost arguments are not the same as the innermost parms of
7555 the most general template.
7557 So it's only when 1/ and 2/ happens that we want to use the partial
7558 instantiation of the member template in lieu of its most general
7561 if (PRIMARY_TEMPLATE_P (gen_tmpl)
7562 && TMPL_ARGS_HAVE_MULTIPLE_LEVELS (arglist)
7563 /* the enclosing class must be an instantiation... */
7564 && CLASS_TYPE_P (context)
7565 && !same_type_p (context, DECL_CONTEXT (gen_tmpl)))
7567 tree partial_inst_args;
7568 TREE_VEC_LENGTH (arglist)--;
7569 ++processing_template_decl;
7571 tsubst (INNERMOST_TEMPLATE_ARGS
7572 (TYPE_TI_ARGS (TREE_TYPE (gen_tmpl))),
7573 arglist, complain, NULL_TREE);
7574 --processing_template_decl;
7575 TREE_VEC_LENGTH (arglist)++;
7576 use_partial_inst_tmpl =
7577 /*...and we must not be looking at the partial instantiation
7579 !comp_template_args (INNERMOST_TEMPLATE_ARGS (arglist),
7583 if (!use_partial_inst_tmpl)
7584 /* This case is easy; there are no member templates involved. */
7588 /* This is a full instantiation of a member template. Find
7589 the partial instantiation of which this is an instance. */
7591 /* Temporarily reduce by one the number of levels in the ARGLIST
7592 so as to avoid comparing the last set of arguments. */
7593 TREE_VEC_LENGTH (arglist)--;
7594 found = tsubst (gen_tmpl, arglist, complain, NULL_TREE);
7595 TREE_VEC_LENGTH (arglist)++;
7596 /* FOUND is either a proper class type, or an alias
7597 template specialization. In the later case, it's a
7598 TYPE_DECL, resulting from the substituting of arguments
7599 for parameters in the TYPE_DECL of the alias template
7600 done earlier. So be careful while getting the template
7602 found = TREE_CODE (found) == TYPE_DECL
7603 ? TYPE_TI_TEMPLATE (TREE_TYPE (found))
7604 : CLASSTYPE_TI_TEMPLATE (found);
7607 SET_TYPE_TEMPLATE_INFO (t, build_template_info (found, arglist));
7610 slot = htab_find_slot_with_hash (type_specializations,
7611 &elt, hash, INSERT);
7612 entry = ggc_alloc_spec_entry ();
7616 /* Note this use of the partial instantiation so we can check it
7617 later in maybe_process_partial_specialization. */
7618 DECL_TEMPLATE_INSTANTIATIONS (templ)
7619 = tree_cons (arglist, t,
7620 DECL_TEMPLATE_INSTANTIATIONS (templ));
7622 if (TREE_CODE (t) == ENUMERAL_TYPE && !is_dependent_type)
7623 /* Now that the type has been registered on the instantiations
7624 list, we set up the enumerators. Because the enumeration
7625 constants may involve the enumeration type itself, we make
7626 sure to register the type first, and then create the
7627 constants. That way, doing tsubst_expr for the enumeration
7628 constants won't result in recursive calls here; we'll find
7629 the instantiation and exit above. */
7630 tsubst_enum (template_type, t, arglist);
7632 if (CLASS_TYPE_P (template_type) && is_dependent_type)
7633 /* If the type makes use of template parameters, the
7634 code that generates debugging information will crash. */
7635 DECL_IGNORED_P (TYPE_STUB_DECL (t)) = 1;
7637 /* Possibly limit visibility based on template args. */
7638 TREE_PUBLIC (type_decl) = 1;
7639 determine_visibility (type_decl);
7645 /* Wrapper for lookup_template_class_1. */
7648 lookup_template_class (tree d1, tree arglist, tree in_decl, tree context,
7649 int entering_scope, tsubst_flags_t complain)
7652 timevar_push (TV_TEMPLATE_INST);
7653 ret = lookup_template_class_1 (d1, arglist, in_decl, context,
7654 entering_scope, complain);
7655 timevar_pop (TV_TEMPLATE_INST);
7663 /* True when we should also visit template parameters that occur in
7664 non-deduced contexts. */
7665 bool include_nondeduced_p;
7666 struct pointer_set_t *visited;
7669 /* Called from for_each_template_parm via walk_tree. */
7672 for_each_template_parm_r (tree *tp, int *walk_subtrees, void *d)
7675 struct pair_fn_data *pfd = (struct pair_fn_data *) d;
7676 tree_fn_t fn = pfd->fn;
7677 void *data = pfd->data;
7680 && (pfd->include_nondeduced_p || TREE_CODE (t) != TYPENAME_TYPE)
7681 && for_each_template_parm (TYPE_CONTEXT (t), fn, data, pfd->visited,
7682 pfd->include_nondeduced_p))
7683 return error_mark_node;
7685 switch (TREE_CODE (t))
7688 if (TYPE_PTRMEMFUNC_P (t))
7694 if (!TYPE_TEMPLATE_INFO (t))
7696 else if (for_each_template_parm (TI_ARGS (TYPE_TEMPLATE_INFO (t)),
7697 fn, data, pfd->visited,
7698 pfd->include_nondeduced_p))
7699 return error_mark_node;
7703 if (for_each_template_parm (TYPE_MIN_VALUE (t),
7704 fn, data, pfd->visited,
7705 pfd->include_nondeduced_p)
7706 || for_each_template_parm (TYPE_MAX_VALUE (t),
7707 fn, data, pfd->visited,
7708 pfd->include_nondeduced_p))
7709 return error_mark_node;
7713 /* Since we're not going to walk subtrees, we have to do this
7715 if (for_each_template_parm (TYPE_METHOD_BASETYPE (t), fn, data,
7716 pfd->visited, pfd->include_nondeduced_p))
7717 return error_mark_node;
7721 /* Check the return type. */
7722 if (for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
7723 pfd->include_nondeduced_p))
7724 return error_mark_node;
7726 /* Check the parameter types. Since default arguments are not
7727 instantiated until they are needed, the TYPE_ARG_TYPES may
7728 contain expressions that involve template parameters. But,
7729 no-one should be looking at them yet. And, once they're
7730 instantiated, they don't contain template parameters, so
7731 there's no point in looking at them then, either. */
7735 for (parm = TYPE_ARG_TYPES (t); parm; parm = TREE_CHAIN (parm))
7736 if (for_each_template_parm (TREE_VALUE (parm), fn, data,
7737 pfd->visited, pfd->include_nondeduced_p))
7738 return error_mark_node;
7740 /* Since we've already handled the TYPE_ARG_TYPES, we don't
7741 want walk_tree walking into them itself. */
7747 case UNDERLYING_TYPE:
7748 if (pfd->include_nondeduced_p
7749 && for_each_template_parm (TYPE_FIELDS (t), fn, data,
7751 pfd->include_nondeduced_p))
7752 return error_mark_node;
7757 if (DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t)
7758 && for_each_template_parm (DECL_TI_ARGS (t), fn, data,
7759 pfd->visited, pfd->include_nondeduced_p))
7760 return error_mark_node;
7765 if (TREE_CODE (t) == CONST_DECL && DECL_TEMPLATE_PARM_P (t)
7766 && for_each_template_parm (DECL_INITIAL (t), fn, data,
7767 pfd->visited, pfd->include_nondeduced_p))
7768 return error_mark_node;
7769 if (DECL_CONTEXT (t)
7770 && pfd->include_nondeduced_p
7771 && for_each_template_parm (DECL_CONTEXT (t), fn, data,
7772 pfd->visited, pfd->include_nondeduced_p))
7773 return error_mark_node;
7776 case BOUND_TEMPLATE_TEMPLATE_PARM:
7777 /* Record template parameters such as `T' inside `TT<T>'. */
7778 if (for_each_template_parm (TYPE_TI_ARGS (t), fn, data, pfd->visited,
7779 pfd->include_nondeduced_p))
7780 return error_mark_node;
7783 case TEMPLATE_TEMPLATE_PARM:
7784 case TEMPLATE_TYPE_PARM:
7785 case TEMPLATE_PARM_INDEX:
7786 if (fn && (*fn)(t, data))
7787 return error_mark_node;
7789 return error_mark_node;
7793 /* A template template parameter is encountered. */
7794 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t)
7795 && for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
7796 pfd->include_nondeduced_p))
7797 return error_mark_node;
7799 /* Already substituted template template parameter */
7805 || for_each_template_parm (TYPENAME_TYPE_FULLNAME (t), fn,
7807 pfd->include_nondeduced_p))
7808 return error_mark_node;
7812 if (TREE_TYPE (t) && TYPE_PTRMEMFUNC_P (TREE_TYPE (t))
7813 && pfd->include_nondeduced_p
7814 && for_each_template_parm (TYPE_PTRMEMFUNC_FN_TYPE
7815 (TREE_TYPE (t)), fn, data,
7816 pfd->visited, pfd->include_nondeduced_p))
7817 return error_mark_node;
7822 /* If there's no type, then this thing must be some expression
7823 involving template parameters. */
7824 if (!fn && !TREE_TYPE (t))
7825 return error_mark_node;
7830 case IMPLICIT_CONV_EXPR:
7831 case REINTERPRET_CAST_EXPR:
7832 case CONST_CAST_EXPR:
7833 case STATIC_CAST_EXPR:
7834 case DYNAMIC_CAST_EXPR:
7838 case PSEUDO_DTOR_EXPR:
7840 return error_mark_node;
7847 /* We didn't find any template parameters we liked. */
7851 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
7852 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
7853 call FN with the parameter and the DATA.
7854 If FN returns nonzero, the iteration is terminated, and
7855 for_each_template_parm returns 1. Otherwise, the iteration
7856 continues. If FN never returns a nonzero value, the value
7857 returned by for_each_template_parm is 0. If FN is NULL, it is
7858 considered to be the function which always returns 1.
7860 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
7861 parameters that occur in non-deduced contexts. When false, only
7862 visits those template parameters that can be deduced. */
7865 for_each_template_parm (tree t, tree_fn_t fn, void* data,
7866 struct pointer_set_t *visited,
7867 bool include_nondeduced_p)
7869 struct pair_fn_data pfd;
7875 pfd.include_nondeduced_p = include_nondeduced_p;
7877 /* Walk the tree. (Conceptually, we would like to walk without
7878 duplicates, but for_each_template_parm_r recursively calls
7879 for_each_template_parm, so we would need to reorganize a fair
7880 bit to use walk_tree_without_duplicates, so we keep our own
7883 pfd.visited = visited;
7885 pfd.visited = pointer_set_create ();
7886 result = cp_walk_tree (&t,
7887 for_each_template_parm_r,
7889 pfd.visited) != NULL_TREE;
7894 pointer_set_destroy (pfd.visited);
7901 /* Returns true if T depends on any template parameter. */
7904 uses_template_parms (tree t)
7907 int saved_processing_template_decl;
7909 saved_processing_template_decl = processing_template_decl;
7910 if (!saved_processing_template_decl)
7911 processing_template_decl = 1;
7913 dependent_p = dependent_type_p (t);
7914 else if (TREE_CODE (t) == TREE_VEC)
7915 dependent_p = any_dependent_template_arguments_p (t);
7916 else if (TREE_CODE (t) == TREE_LIST)
7917 dependent_p = (uses_template_parms (TREE_VALUE (t))
7918 || uses_template_parms (TREE_CHAIN (t)));
7919 else if (TREE_CODE (t) == TYPE_DECL)
7920 dependent_p = dependent_type_p (TREE_TYPE (t));
7923 || TREE_CODE (t) == TEMPLATE_PARM_INDEX
7924 || TREE_CODE (t) == OVERLOAD
7926 || TREE_CODE (t) == IDENTIFIER_NODE
7927 || TREE_CODE (t) == TRAIT_EXPR
7928 || TREE_CODE (t) == CONSTRUCTOR
7929 || CONSTANT_CLASS_P (t))
7930 dependent_p = (type_dependent_expression_p (t)
7931 || value_dependent_expression_p (t));
7934 gcc_assert (t == error_mark_node);
7935 dependent_p = false;
7938 processing_template_decl = saved_processing_template_decl;
7943 /* Returns true if T depends on any template parameter with level LEVEL. */
7946 uses_template_parms_level (tree t, int level)
7948 return for_each_template_parm (t, template_parm_this_level_p, &level, NULL,
7949 /*include_nondeduced_p=*/true);
7952 /* Returns TRUE iff INST is an instantiation we don't need to do in an
7953 ill-formed translation unit, i.e. a variable or function that isn't
7954 usable in a constant expression. */
7957 neglectable_inst_p (tree d)
7960 && !(TREE_CODE (d) == FUNCTION_DECL ? DECL_DECLARED_CONSTEXPR_P (d)
7961 : decl_maybe_constant_var_p (d)));
7964 /* Returns TRUE iff we should refuse to instantiate DECL because it's
7965 neglectable and instantiated from within an erroneous instantiation. */
7968 limit_bad_template_recursion (tree decl)
7970 struct tinst_level *lev = current_tinst_level;
7971 int errs = errorcount + sorrycount;
7972 if (lev == NULL || errs == 0 || !neglectable_inst_p (decl))
7975 for (; lev; lev = lev->next)
7976 if (neglectable_inst_p (lev->decl))
7979 return (lev && errs > lev->errors);
7982 static int tinst_depth;
7983 extern int max_tinst_depth;
7984 #ifdef GATHER_STATISTICS
7987 static GTY(()) struct tinst_level *last_error_tinst_level;
7989 /* We're starting to instantiate D; record the template instantiation context
7990 for diagnostics and to restore it later. */
7993 push_tinst_level (tree d)
7995 struct tinst_level *new_level;
7997 if (tinst_depth >= max_tinst_depth)
7999 last_error_tinst_level = current_tinst_level;
8000 if (TREE_CODE (d) == TREE_LIST)
8001 error ("template instantiation depth exceeds maximum of %d (use "
8002 "-ftemplate-depth= to increase the maximum) substituting %qS",
8003 max_tinst_depth, d);
8005 error ("template instantiation depth exceeds maximum of %d (use "
8006 "-ftemplate-depth= to increase the maximum) instantiating %qD",
8007 max_tinst_depth, d);
8009 print_instantiation_context ();
8014 /* If the current instantiation caused problems, don't let it instantiate
8015 anything else. Do allow deduction substitution and decls usable in
8016 constant expressions. */
8017 if (limit_bad_template_recursion (d))
8020 new_level = ggc_alloc_tinst_level ();
8021 new_level->decl = d;
8022 new_level->locus = input_location;
8023 new_level->errors = errorcount+sorrycount;
8024 new_level->in_system_header_p = in_system_header;
8025 new_level->next = current_tinst_level;
8026 current_tinst_level = new_level;
8029 #ifdef GATHER_STATISTICS
8030 if (tinst_depth > depth_reached)
8031 depth_reached = tinst_depth;
8037 /* We're done instantiating this template; return to the instantiation
8041 pop_tinst_level (void)
8043 /* Restore the filename and line number stashed away when we started
8044 this instantiation. */
8045 input_location = current_tinst_level->locus;
8046 current_tinst_level = current_tinst_level->next;
8050 /* We're instantiating a deferred template; restore the template
8051 instantiation context in which the instantiation was requested, which
8052 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
8055 reopen_tinst_level (struct tinst_level *level)
8057 struct tinst_level *t;
8060 for (t = level; t; t = t->next)
8063 current_tinst_level = level;
8065 if (current_tinst_level)
8066 current_tinst_level->errors = errorcount+sorrycount;
8070 /* Returns the TINST_LEVEL which gives the original instantiation
8073 struct tinst_level *
8074 outermost_tinst_level (void)
8076 struct tinst_level *level = current_tinst_level;
8079 level = level->next;
8083 /* Returns TRUE if PARM is a parameter of the template TEMPL. */
8086 parameter_of_template_p (tree parm, tree templ)
8091 if (!parm || !templ)
8094 gcc_assert (DECL_TEMPLATE_PARM_P (parm));
8095 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
8097 parms = DECL_TEMPLATE_PARMS (templ);
8098 parms = INNERMOST_TEMPLATE_PARMS (parms);
8100 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
8102 tree p = TREE_VALUE (TREE_VEC_ELT (parms, i));
8104 || (DECL_INITIAL (parm)
8105 && DECL_INITIAL (parm) == DECL_INITIAL (p)))
8112 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
8113 vector of template arguments, as for tsubst.
8115 Returns an appropriate tsubst'd friend declaration. */
8118 tsubst_friend_function (tree decl, tree args)
8122 if (TREE_CODE (decl) == FUNCTION_DECL
8123 && DECL_TEMPLATE_INSTANTIATION (decl)
8124 && TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
8125 /* This was a friend declared with an explicit template
8126 argument list, e.g.:
8130 to indicate that f was a template instantiation, not a new
8131 function declaration. Now, we have to figure out what
8132 instantiation of what template. */
8134 tree template_id, arglist, fns;
8137 tree ns = decl_namespace_context (TYPE_MAIN_DECL (current_class_type));
8139 /* Friend functions are looked up in the containing namespace scope.
8140 We must enter that scope, to avoid finding member functions of the
8141 current class with same name. */
8142 push_nested_namespace (ns);
8143 fns = tsubst_expr (DECL_TI_TEMPLATE (decl), args,
8144 tf_warning_or_error, NULL_TREE,
8145 /*integral_constant_expression_p=*/false);
8146 pop_nested_namespace (ns);
8147 arglist = tsubst (DECL_TI_ARGS (decl), args,
8148 tf_warning_or_error, NULL_TREE);
8149 template_id = lookup_template_function (fns, arglist);
8151 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
8152 tmpl = determine_specialization (template_id, new_friend,
8154 /*need_member_template=*/0,
8155 TREE_VEC_LENGTH (args),
8157 return instantiate_template (tmpl, new_args, tf_error);
8160 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
8162 /* The NEW_FRIEND will look like an instantiation, to the
8163 compiler, but is not an instantiation from the point of view of
8164 the language. For example, we might have had:
8166 template <class T> struct S {
8167 template <class U> friend void f(T, U);
8170 Then, in S<int>, template <class U> void f(int, U) is not an
8171 instantiation of anything. */
8172 if (new_friend == error_mark_node)
8173 return error_mark_node;
8175 DECL_USE_TEMPLATE (new_friend) = 0;
8176 if (TREE_CODE (decl) == TEMPLATE_DECL)
8178 DECL_USE_TEMPLATE (DECL_TEMPLATE_RESULT (new_friend)) = 0;
8179 DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (new_friend))
8180 = DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (decl));
8183 /* The mangled name for the NEW_FRIEND is incorrect. The function
8184 is not a template instantiation and should not be mangled like
8185 one. Therefore, we forget the mangling here; we'll recompute it
8186 later if we need it. */
8187 if (TREE_CODE (new_friend) != TEMPLATE_DECL)
8189 SET_DECL_RTL (new_friend, NULL);
8190 SET_DECL_ASSEMBLER_NAME (new_friend, NULL_TREE);
8193 if (DECL_NAMESPACE_SCOPE_P (new_friend))
8196 tree new_friend_template_info;
8197 tree new_friend_result_template_info;
8199 int new_friend_is_defn;
8201 /* We must save some information from NEW_FRIEND before calling
8202 duplicate decls since that function will free NEW_FRIEND if
8204 new_friend_template_info = DECL_TEMPLATE_INFO (new_friend);
8205 new_friend_is_defn =
8206 (DECL_INITIAL (DECL_TEMPLATE_RESULT
8207 (template_for_substitution (new_friend)))
8209 if (TREE_CODE (new_friend) == TEMPLATE_DECL)
8211 /* This declaration is a `primary' template. */
8212 DECL_PRIMARY_TEMPLATE (new_friend) = new_friend;
8214 new_friend_result_template_info
8215 = DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (new_friend));
8218 new_friend_result_template_info = NULL_TREE;
8220 /* Make the init_value nonzero so pushdecl knows this is a defn. */
8221 if (new_friend_is_defn)
8222 DECL_INITIAL (new_friend) = error_mark_node;
8224 /* Inside pushdecl_namespace_level, we will push into the
8225 current namespace. However, the friend function should go
8226 into the namespace of the template. */
8227 ns = decl_namespace_context (new_friend);
8228 push_nested_namespace (ns);
8229 old_decl = pushdecl_namespace_level (new_friend, /*is_friend=*/true);
8230 pop_nested_namespace (ns);
8232 if (old_decl == error_mark_node)
8233 return error_mark_node;
8235 if (old_decl != new_friend)
8237 /* This new friend declaration matched an existing
8238 declaration. For example, given:
8240 template <class T> void f(T);
8241 template <class U> class C {
8242 template <class T> friend void f(T) {}
8245 the friend declaration actually provides the definition
8246 of `f', once C has been instantiated for some type. So,
8247 old_decl will be the out-of-class template declaration,
8248 while new_friend is the in-class definition.
8250 But, if `f' was called before this point, the
8251 instantiation of `f' will have DECL_TI_ARGS corresponding
8252 to `T' but not to `U', references to which might appear
8253 in the definition of `f'. Previously, the most general
8254 template for an instantiation of `f' was the out-of-class
8255 version; now it is the in-class version. Therefore, we
8256 run through all specialization of `f', adding to their
8257 DECL_TI_ARGS appropriately. In particular, they need a
8258 new set of outer arguments, corresponding to the
8259 arguments for this class instantiation.
8261 The same situation can arise with something like this:
8264 template <class T> class C {
8268 when `C<int>' is instantiated. Now, `f(int)' is defined
8271 if (!new_friend_is_defn)
8272 /* On the other hand, if the in-class declaration does
8273 *not* provide a definition, then we don't want to alter
8274 existing definitions. We can just leave everything
8279 tree new_template = TI_TEMPLATE (new_friend_template_info);
8280 tree new_args = TI_ARGS (new_friend_template_info);
8282 /* Overwrite whatever template info was there before, if
8283 any, with the new template information pertaining to
8285 DECL_TEMPLATE_INFO (old_decl) = new_friend_template_info;
8287 if (TREE_CODE (old_decl) != TEMPLATE_DECL)
8289 /* We should have called reregister_specialization in
8291 gcc_assert (retrieve_specialization (new_template,
8295 /* Instantiate it if the global has already been used. */
8296 if (DECL_ODR_USED (old_decl))
8297 instantiate_decl (old_decl, /*defer_ok=*/true,
8298 /*expl_inst_class_mem_p=*/false);
8304 /* Indicate that the old function template is a partial
8306 DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (old_decl))
8307 = new_friend_result_template_info;
8309 gcc_assert (new_template
8310 == most_general_template (new_template));
8311 gcc_assert (new_template != old_decl);
8313 /* Reassign any specializations already in the hash table
8314 to the new more general template, and add the
8315 additional template args. */
8316 for (t = DECL_TEMPLATE_INSTANTIATIONS (old_decl);
8320 tree spec = TREE_VALUE (t);
8323 elt.tmpl = old_decl;
8324 elt.args = DECL_TI_ARGS (spec);
8325 elt.spec = NULL_TREE;
8327 htab_remove_elt (decl_specializations, &elt);
8330 = add_outermost_template_args (new_args,
8331 DECL_TI_ARGS (spec));
8333 register_specialization
8334 (spec, new_template, DECL_TI_ARGS (spec), true, 0);
8337 DECL_TEMPLATE_INSTANTIATIONS (old_decl) = NULL_TREE;
8341 /* The information from NEW_FRIEND has been merged into OLD_DECL
8342 by duplicate_decls. */
8343 new_friend = old_decl;
8348 tree context = DECL_CONTEXT (new_friend);
8352 template <class T> class C {
8353 template <class U> friend void C1<U>::f (); // case 1
8354 friend void C2<T>::f (); // case 2
8356 we only need to make sure CONTEXT is a complete type for
8357 case 2. To distinguish between the two cases, we note that
8358 CONTEXT of case 1 remains dependent type after tsubst while
8359 this isn't true for case 2. */
8360 ++processing_template_decl;
8361 dependent_p = dependent_type_p (context);
8362 --processing_template_decl;
8365 && !complete_type_or_else (context, NULL_TREE))
8366 return error_mark_node;
8368 if (COMPLETE_TYPE_P (context))
8370 /* Check to see that the declaration is really present, and,
8371 possibly obtain an improved declaration. */
8372 tree fn = check_classfn (context,
8373 new_friend, NULL_TREE);
8383 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
8384 template arguments, as for tsubst.
8386 Returns an appropriate tsubst'd friend type or error_mark_node on
8390 tsubst_friend_class (tree friend_tmpl, tree args)
8396 context = CP_DECL_CONTEXT (friend_tmpl);
8398 if (context != global_namespace)
8400 if (TREE_CODE (context) == NAMESPACE_DECL)
8401 push_nested_namespace (context);
8403 push_nested_class (tsubst (context, args, tf_none, NULL_TREE));
8406 /* Look for a class template declaration. We look for hidden names
8407 because two friend declarations of the same template are the
8408 same. For example, in:
8411 template <typename> friend class F;
8413 template <typename> struct B {
8414 template <typename> friend class F;
8417 both F templates are the same. */
8418 tmpl = lookup_name_real (DECL_NAME (friend_tmpl), 0, 0,
8419 /*block_p=*/true, 0,
8420 LOOKUP_COMPLAIN | LOOKUP_HIDDEN);
8422 /* But, if we don't find one, it might be because we're in a
8423 situation like this:
8431 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
8432 for `S<int>', not the TEMPLATE_DECL. */
8433 if (!tmpl || !DECL_CLASS_TEMPLATE_P (tmpl))
8435 tmpl = lookup_name_prefer_type (DECL_NAME (friend_tmpl), 1);
8436 tmpl = maybe_get_template_decl_from_type_decl (tmpl);
8439 if (tmpl && DECL_CLASS_TEMPLATE_P (tmpl))
8441 /* The friend template has already been declared. Just
8442 check to see that the declarations match, and install any new
8443 default parameters. We must tsubst the default parameters,
8444 of course. We only need the innermost template parameters
8445 because that is all that redeclare_class_template will look
8447 if (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (friend_tmpl))
8448 > TMPL_ARGS_DEPTH (args))
8451 location_t saved_input_location;
8452 parms = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_tmpl),
8453 args, tf_warning_or_error);
8455 saved_input_location = input_location;
8456 input_location = DECL_SOURCE_LOCATION (friend_tmpl);
8457 redeclare_class_template (TREE_TYPE (tmpl), parms);
8458 input_location = saved_input_location;
8462 friend_type = TREE_TYPE (tmpl);
8466 /* The friend template has not already been declared. In this
8467 case, the instantiation of the template class will cause the
8468 injection of this template into the global scope. */
8469 tmpl = tsubst (friend_tmpl, args, tf_warning_or_error, NULL_TREE);
8470 if (tmpl == error_mark_node)
8471 return error_mark_node;
8473 /* The new TMPL is not an instantiation of anything, so we
8474 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
8475 the new type because that is supposed to be the corresponding
8476 template decl, i.e., TMPL. */
8477 DECL_USE_TEMPLATE (tmpl) = 0;
8478 DECL_TEMPLATE_INFO (tmpl) = NULL_TREE;
8479 CLASSTYPE_USE_TEMPLATE (TREE_TYPE (tmpl)) = 0;
8480 CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl))
8481 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl)));
8483 /* Inject this template into the global scope. */
8484 friend_type = TREE_TYPE (pushdecl_top_level_maybe_friend (tmpl, true));
8487 if (context != global_namespace)
8489 if (TREE_CODE (context) == NAMESPACE_DECL)
8490 pop_nested_namespace (context);
8492 pop_nested_class ();
8498 /* Returns zero if TYPE cannot be completed later due to circularity.
8499 Otherwise returns one. */
8502 can_complete_type_without_circularity (tree type)
8504 if (type == NULL_TREE || type == error_mark_node)
8506 else if (COMPLETE_TYPE_P (type))
8508 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
8509 return can_complete_type_without_circularity (TREE_TYPE (type));
8510 else if (CLASS_TYPE_P (type)
8511 && TYPE_BEING_DEFINED (TYPE_MAIN_VARIANT (type)))
8517 /* Apply any attributes which had to be deferred until instantiation
8518 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
8519 ARGS, COMPLAIN, IN_DECL are as tsubst. */
8522 apply_late_template_attributes (tree *decl_p, tree attributes, int attr_flags,
8523 tree args, tsubst_flags_t complain, tree in_decl)
8525 tree last_dep = NULL_TREE;
8529 for (t = attributes; t; t = TREE_CHAIN (t))
8530 if (ATTR_IS_DEPENDENT (t))
8533 attributes = copy_list (attributes);
8537 if (DECL_P (*decl_p))
8539 if (TREE_TYPE (*decl_p) == error_mark_node)
8541 p = &DECL_ATTRIBUTES (*decl_p);
8544 p = &TYPE_ATTRIBUTES (*decl_p);
8548 tree late_attrs = NULL_TREE;
8549 tree *q = &late_attrs;
8551 for (*p = attributes; *p; )
8554 if (ATTR_IS_DEPENDENT (t))
8556 *p = TREE_CHAIN (t);
8557 TREE_CHAIN (t) = NULL_TREE;
8558 /* If the first attribute argument is an identifier, don't
8559 pass it through tsubst. Attributes like mode, format,
8560 cleanup and several target specific attributes expect it
8563 && TREE_CODE (TREE_VALUE (t)) == TREE_LIST
8564 && TREE_VALUE (TREE_VALUE (t))
8565 && (TREE_CODE (TREE_VALUE (TREE_VALUE (t)))
8566 == IDENTIFIER_NODE))
8569 = tsubst_expr (TREE_CHAIN (TREE_VALUE (t)), args, complain,
8571 /*integral_constant_expression_p=*/false);
8572 if (chain != TREE_CHAIN (TREE_VALUE (t)))
8574 = tree_cons (NULL_TREE, TREE_VALUE (TREE_VALUE (t)),
8579 = tsubst_expr (TREE_VALUE (t), args, complain, in_decl,
8580 /*integral_constant_expression_p=*/false);
8582 q = &TREE_CHAIN (t);
8585 p = &TREE_CHAIN (t);
8588 cplus_decl_attributes (decl_p, late_attrs, attr_flags);
8592 /* Perform (or defer) access check for typedefs that were referenced
8593 from within the template TMPL code.
8594 This is a subroutine of instantiate_template and instantiate_class_template.
8595 TMPL is the template to consider and TARGS is the list of arguments of
8599 perform_typedefs_access_check (tree tmpl, tree targs)
8601 location_t saved_location;
8603 qualified_typedef_usage_t *iter;
8606 || (!CLASS_TYPE_P (tmpl)
8607 && TREE_CODE (tmpl) != FUNCTION_DECL))
8610 saved_location = input_location;
8611 FOR_EACH_VEC_ELT (qualified_typedef_usage_t,
8612 get_types_needing_access_check (tmpl),
8615 tree type_decl = iter->typedef_decl;
8616 tree type_scope = iter->context;
8618 if (!type_decl || !type_scope || !CLASS_TYPE_P (type_scope))
8621 if (uses_template_parms (type_decl))
8622 type_decl = tsubst (type_decl, targs, tf_error, NULL_TREE);
8623 if (uses_template_parms (type_scope))
8624 type_scope = tsubst (type_scope, targs, tf_error, NULL_TREE);
8626 /* Make access check error messages point to the location
8627 of the use of the typedef. */
8628 input_location = iter->locus;
8629 perform_or_defer_access_check (TYPE_BINFO (type_scope),
8630 type_decl, type_decl);
8632 input_location = saved_location;
8636 instantiate_class_template_1 (tree type)
8638 tree templ, args, pattern, t, member;
8642 unsigned int saved_maximum_field_alignment;
8644 if (type == error_mark_node)
8645 return error_mark_node;
8647 if (COMPLETE_OR_OPEN_TYPE_P (type)
8648 || uses_template_parms (type))
8651 /* Figure out which template is being instantiated. */
8652 templ = most_general_template (CLASSTYPE_TI_TEMPLATE (type));
8653 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
8655 /* Determine what specialization of the original template to
8657 t = most_specialized_class (type, templ, tf_warning_or_error);
8658 if (t == error_mark_node)
8660 TYPE_BEING_DEFINED (type) = 1;
8661 return error_mark_node;
8665 /* This TYPE is actually an instantiation of a partial
8666 specialization. We replace the innermost set of ARGS with
8667 the arguments appropriate for substitution. For example,
8670 template <class T> struct S {};
8671 template <class T> struct S<T*> {};
8673 and supposing that we are instantiating S<int*>, ARGS will
8674 presently be {int*} -- but we need {int}. */
8675 pattern = TREE_TYPE (t);
8676 args = TREE_PURPOSE (t);
8680 pattern = TREE_TYPE (templ);
8681 args = CLASSTYPE_TI_ARGS (type);
8684 /* If the template we're instantiating is incomplete, then clearly
8685 there's nothing we can do. */
8686 if (!COMPLETE_TYPE_P (pattern))
8689 /* If we've recursively instantiated too many templates, stop. */
8690 if (! push_tinst_level (type))
8693 /* Now we're really doing the instantiation. Mark the type as in
8694 the process of being defined. */
8695 TYPE_BEING_DEFINED (type) = 1;
8697 /* We may be in the middle of deferred access check. Disable
8699 push_deferring_access_checks (dk_no_deferred);
8701 push_to_top_level ();
8702 /* Use #pragma pack from the template context. */
8703 saved_maximum_field_alignment = maximum_field_alignment;
8704 maximum_field_alignment = TYPE_PRECISION (pattern);
8706 SET_CLASSTYPE_INTERFACE_UNKNOWN (type);
8708 /* Set the input location to the most specialized template definition.
8709 This is needed if tsubsting causes an error. */
8710 typedecl = TYPE_MAIN_DECL (pattern);
8711 input_location = DECL_SOURCE_LOCATION (TYPE_NAME (type)) =
8712 DECL_SOURCE_LOCATION (typedecl);
8714 TYPE_PACKED (type) = TYPE_PACKED (pattern);
8715 TYPE_ALIGN (type) = TYPE_ALIGN (pattern);
8716 TYPE_USER_ALIGN (type) = TYPE_USER_ALIGN (pattern);
8717 TYPE_FOR_JAVA (type) = TYPE_FOR_JAVA (pattern); /* For libjava's JArray<T> */
8718 if (ANON_AGGR_TYPE_P (pattern))
8719 SET_ANON_AGGR_TYPE_P (type);
8720 if (CLASSTYPE_VISIBILITY_SPECIFIED (pattern))
8722 CLASSTYPE_VISIBILITY_SPECIFIED (type) = 1;
8723 CLASSTYPE_VISIBILITY (type) = CLASSTYPE_VISIBILITY (pattern);
8724 /* Adjust visibility for template arguments. */
8725 determine_visibility (TYPE_MAIN_DECL (type));
8727 CLASSTYPE_FINAL (type) = CLASSTYPE_FINAL (pattern);
8729 pbinfo = TYPE_BINFO (pattern);
8731 /* We should never instantiate a nested class before its enclosing
8732 class; we need to look up the nested class by name before we can
8733 instantiate it, and that lookup should instantiate the enclosing
8735 gcc_assert (!DECL_CLASS_SCOPE_P (TYPE_MAIN_DECL (pattern))
8736 || COMPLETE_OR_OPEN_TYPE_P (TYPE_CONTEXT (type)));
8738 base_list = NULL_TREE;
8739 if (BINFO_N_BASE_BINFOS (pbinfo))
8745 /* We must enter the scope containing the type, as that is where
8746 the accessibility of types named in dependent bases are
8748 pushed_scope = push_scope (CP_TYPE_CONTEXT (type));
8750 /* Substitute into each of the bases to determine the actual
8752 for (i = 0; BINFO_BASE_ITERATE (pbinfo, i, pbase_binfo); i++)
8755 tree access = BINFO_BASE_ACCESS (pbinfo, i);
8756 tree expanded_bases = NULL_TREE;
8759 if (PACK_EXPANSION_P (BINFO_TYPE (pbase_binfo)))
8762 tsubst_pack_expansion (BINFO_TYPE (pbase_binfo),
8763 args, tf_error, NULL_TREE);
8764 if (expanded_bases == error_mark_node)
8767 len = TREE_VEC_LENGTH (expanded_bases);
8770 for (idx = 0; idx < len; idx++)
8773 /* Extract the already-expanded base class. */
8774 base = TREE_VEC_ELT (expanded_bases, idx);
8776 /* Substitute to figure out the base class. */
8777 base = tsubst (BINFO_TYPE (pbase_binfo), args, tf_error,
8780 if (base == error_mark_node)
8783 base_list = tree_cons (access, base, base_list);
8784 if (BINFO_VIRTUAL_P (pbase_binfo))
8785 TREE_TYPE (base_list) = integer_type_node;
8789 /* The list is now in reverse order; correct that. */
8790 base_list = nreverse (base_list);
8793 pop_scope (pushed_scope);
8795 /* Now call xref_basetypes to set up all the base-class
8797 xref_basetypes (type, base_list);
8799 apply_late_template_attributes (&type, TYPE_ATTRIBUTES (pattern),
8800 (int) ATTR_FLAG_TYPE_IN_PLACE,
8801 args, tf_error, NULL_TREE);
8802 fixup_attribute_variants (type);
8804 /* Now that our base classes are set up, enter the scope of the
8805 class, so that name lookups into base classes, etc. will work
8806 correctly. This is precisely analogous to what we do in
8807 begin_class_definition when defining an ordinary non-template
8808 class, except we also need to push the enclosing classes. */
8809 push_nested_class (type);
8811 /* Now members are processed in the order of declaration. */
8812 for (member = CLASSTYPE_DECL_LIST (pattern);
8813 member; member = TREE_CHAIN (member))
8815 tree t = TREE_VALUE (member);
8817 if (TREE_PURPOSE (member))
8821 /* Build new CLASSTYPE_NESTED_UTDS. */
8824 bool class_template_p;
8826 class_template_p = (TREE_CODE (t) != ENUMERAL_TYPE
8827 && TYPE_LANG_SPECIFIC (t)
8828 && CLASSTYPE_IS_TEMPLATE (t));
8829 /* If the member is a class template, then -- even after
8830 substitution -- there may be dependent types in the
8831 template argument list for the class. We increment
8832 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
8833 that function will assume that no types are dependent
8834 when outside of a template. */
8835 if (class_template_p)
8836 ++processing_template_decl;
8837 newtag = tsubst (t, args, tf_error, NULL_TREE);
8838 if (class_template_p)
8839 --processing_template_decl;
8840 if (newtag == error_mark_node)
8843 if (TREE_CODE (newtag) != ENUMERAL_TYPE)
8845 tree name = TYPE_IDENTIFIER (t);
8847 if (class_template_p)
8848 /* Unfortunately, lookup_template_class sets
8849 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
8850 instantiation (i.e., for the type of a member
8851 template class nested within a template class.)
8852 This behavior is required for
8853 maybe_process_partial_specialization to work
8854 correctly, but is not accurate in this case;
8855 the TAG is not an instantiation of anything.
8856 (The corresponding TEMPLATE_DECL is an
8857 instantiation, but the TYPE is not.) */
8858 CLASSTYPE_USE_TEMPLATE (newtag) = 0;
8860 /* Now, we call pushtag to put this NEWTAG into the scope of
8861 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
8862 pushtag calling push_template_decl. We don't have to do
8863 this for enums because it will already have been done in
8866 SET_IDENTIFIER_TYPE_VALUE (name, newtag);
8867 pushtag (name, newtag, /*tag_scope=*/ts_current);
8870 else if (TREE_CODE (t) == FUNCTION_DECL
8871 || DECL_FUNCTION_TEMPLATE_P (t))
8873 /* Build new TYPE_METHODS. */
8876 if (TREE_CODE (t) == TEMPLATE_DECL)
8877 ++processing_template_decl;
8878 r = tsubst (t, args, tf_error, NULL_TREE);
8879 if (TREE_CODE (t) == TEMPLATE_DECL)
8880 --processing_template_decl;
8881 set_current_access_from_decl (r);
8882 finish_member_declaration (r);
8883 /* Instantiate members marked with attribute used. */
8884 if (r != error_mark_node && DECL_PRESERVE_P (r))
8889 /* Build new TYPE_FIELDS. */
8890 if (TREE_CODE (t) == STATIC_ASSERT)
8893 tsubst_expr (STATIC_ASSERT_CONDITION (t), args,
8894 tf_warning_or_error, NULL_TREE,
8895 /*integral_constant_expression_p=*/true);
8896 finish_static_assert (condition,
8897 STATIC_ASSERT_MESSAGE (t),
8898 STATIC_ASSERT_SOURCE_LOCATION (t),
8901 else if (TREE_CODE (t) != CONST_DECL)
8905 /* The file and line for this declaration, to
8906 assist in error message reporting. Since we
8907 called push_tinst_level above, we don't need to
8909 input_location = DECL_SOURCE_LOCATION (t);
8911 if (TREE_CODE (t) == TEMPLATE_DECL)
8912 ++processing_template_decl;
8913 r = tsubst (t, args, tf_warning_or_error, NULL_TREE);
8914 if (TREE_CODE (t) == TEMPLATE_DECL)
8915 --processing_template_decl;
8916 if (TREE_CODE (r) == VAR_DECL)
8920 [t]he initialization (and any associated
8921 side-effects) of a static data member does
8922 not occur unless the static data member is
8923 itself used in a way that requires the
8924 definition of the static data member to
8927 Therefore, we do not substitute into the
8928 initialized for the static data member here. */
8929 finish_static_data_member_decl
8932 /*init_const_expr_p=*/false,
8933 /*asmspec_tree=*/NULL_TREE,
8935 /* Instantiate members marked with attribute used. */
8936 if (r != error_mark_node && DECL_PRESERVE_P (r))
8939 else if (TREE_CODE (r) == FIELD_DECL)
8941 /* Determine whether R has a valid type and can be
8942 completed later. If R is invalid, then it is
8943 replaced by error_mark_node so that it will not be
8944 added to TYPE_FIELDS. */
8945 tree rtype = TREE_TYPE (r);
8946 if (can_complete_type_without_circularity (rtype))
8947 complete_type (rtype);
8949 if (!COMPLETE_TYPE_P (rtype))
8951 cxx_incomplete_type_error (r, rtype);
8952 r = error_mark_node;
8956 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
8957 such a thing will already have been added to the field
8958 list by tsubst_enum in finish_member_declaration in the
8959 CLASSTYPE_NESTED_UTDS case above. */
8960 if (!(TREE_CODE (r) == TYPE_DECL
8961 && TREE_CODE (TREE_TYPE (r)) == ENUMERAL_TYPE
8962 && DECL_ARTIFICIAL (r)))
8964 set_current_access_from_decl (r);
8965 finish_member_declaration (r);
8972 if (TYPE_P (t) || DECL_CLASS_TEMPLATE_P (t))
8974 /* Build new CLASSTYPE_FRIEND_CLASSES. */
8976 tree friend_type = t;
8977 bool adjust_processing_template_decl = false;
8979 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
8981 /* template <class T> friend class C; */
8982 friend_type = tsubst_friend_class (friend_type, args);
8983 adjust_processing_template_decl = true;
8985 else if (TREE_CODE (friend_type) == UNBOUND_CLASS_TEMPLATE)
8987 /* template <class T> friend class C::D; */
8988 friend_type = tsubst (friend_type, args,
8989 tf_warning_or_error, NULL_TREE);
8990 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
8991 friend_type = TREE_TYPE (friend_type);
8992 adjust_processing_template_decl = true;
8994 else if (TREE_CODE (friend_type) == TYPENAME_TYPE
8995 || TREE_CODE (friend_type) == TEMPLATE_TYPE_PARM)
8997 /* This could be either
9001 when dependent_type_p is false or
9003 template <class U> friend class T::C;
9006 friend_type = tsubst (friend_type, args,
9007 tf_warning_or_error, NULL_TREE);
9008 /* Bump processing_template_decl for correct
9009 dependent_type_p calculation. */
9010 ++processing_template_decl;
9011 if (dependent_type_p (friend_type))
9012 adjust_processing_template_decl = true;
9013 --processing_template_decl;
9015 else if (!CLASSTYPE_USE_TEMPLATE (friend_type)
9016 && hidden_name_p (TYPE_NAME (friend_type)))
9020 where C hasn't been declared yet. Let's lookup name
9021 from namespace scope directly, bypassing any name that
9022 come from dependent base class. */
9023 tree ns = decl_namespace_context (TYPE_MAIN_DECL (friend_type));
9025 /* The call to xref_tag_from_type does injection for friend
9027 push_nested_namespace (ns);
9029 xref_tag_from_type (friend_type, NULL_TREE,
9030 /*tag_scope=*/ts_current);
9031 pop_nested_namespace (ns);
9033 else if (uses_template_parms (friend_type))
9034 /* friend class C<T>; */
9035 friend_type = tsubst (friend_type, args,
9036 tf_warning_or_error, NULL_TREE);
9041 where C is already declared or
9043 friend class C<int>;
9045 We don't have to do anything in these cases. */
9047 if (adjust_processing_template_decl)
9048 /* Trick make_friend_class into realizing that the friend
9049 we're adding is a template, not an ordinary class. It's
9050 important that we use make_friend_class since it will
9051 perform some error-checking and output cross-reference
9053 ++processing_template_decl;
9055 if (friend_type != error_mark_node)
9056 make_friend_class (type, friend_type, /*complain=*/false);
9058 if (adjust_processing_template_decl)
9059 --processing_template_decl;
9063 /* Build new DECL_FRIENDLIST. */
9066 /* The file and line for this declaration, to
9067 assist in error message reporting. Since we
9068 called push_tinst_level above, we don't need to
9070 input_location = DECL_SOURCE_LOCATION (t);
9072 if (TREE_CODE (t) == TEMPLATE_DECL)
9074 ++processing_template_decl;
9075 push_deferring_access_checks (dk_no_check);
9078 r = tsubst_friend_function (t, args);
9079 add_friend (type, r, /*complain=*/false);
9080 if (TREE_CODE (t) == TEMPLATE_DECL)
9082 pop_deferring_access_checks ();
9083 --processing_template_decl;
9089 if (CLASSTYPE_LAMBDA_EXPR (type))
9091 tree lambda = CLASSTYPE_LAMBDA_EXPR (type);
9092 if (LAMBDA_EXPR_DEDUCE_RETURN_TYPE_P (lambda))
9094 apply_lambda_return_type (lambda, void_type_node);
9095 LAMBDA_EXPR_RETURN_TYPE (lambda) = NULL_TREE;
9097 instantiate_decl (lambda_function (type), false, false);
9098 maybe_add_lambda_conv_op (type);
9101 /* Set the file and line number information to whatever is given for
9102 the class itself. This puts error messages involving generated
9103 implicit functions at a predictable point, and the same point
9104 that would be used for non-template classes. */
9105 input_location = DECL_SOURCE_LOCATION (typedecl);
9107 unreverse_member_declarations (type);
9108 finish_struct_1 (type);
9109 TYPE_BEING_DEFINED (type) = 0;
9111 /* We don't instantiate default arguments for member functions. 14.7.1:
9113 The implicit instantiation of a class template specialization causes
9114 the implicit instantiation of the declarations, but not of the
9115 definitions or default arguments, of the class member functions,
9116 member classes, static data members and member templates.... */
9118 /* Some typedefs referenced from within the template code need to be access
9119 checked at template instantiation time, i.e now. These types were
9120 added to the template at parsing time. Let's get those and perform
9121 the access checks then. */
9122 perform_typedefs_access_check (pattern, args);
9123 perform_deferred_access_checks ();
9124 pop_nested_class ();
9125 maximum_field_alignment = saved_maximum_field_alignment;
9126 pop_from_top_level ();
9127 pop_deferring_access_checks ();
9130 /* The vtable for a template class can be emitted in any translation
9131 unit in which the class is instantiated. When there is no key
9132 method, however, finish_struct_1 will already have added TYPE to
9133 the keyed_classes list. */
9134 if (TYPE_CONTAINS_VPTR_P (type) && CLASSTYPE_KEY_METHOD (type))
9135 keyed_classes = tree_cons (NULL_TREE, type, keyed_classes);
9140 /* Wrapper for instantiate_class_template_1. */
9143 instantiate_class_template (tree type)
9146 timevar_push (TV_TEMPLATE_INST);
9147 ret = instantiate_class_template_1 (type);
9148 timevar_pop (TV_TEMPLATE_INST);
9153 tsubst_template_arg (tree t, tree args, tsubst_flags_t complain, tree in_decl)
9159 else if (TYPE_P (t))
9160 r = tsubst (t, args, complain, in_decl);
9163 if (!(complain & tf_warning))
9164 ++c_inhibit_evaluation_warnings;
9165 r = tsubst_expr (t, args, complain, in_decl,
9166 /*integral_constant_expression_p=*/true);
9167 if (!(complain & tf_warning))
9168 --c_inhibit_evaluation_warnings;
9169 /* Preserve the raw-reference nature of T. */
9170 if (TREE_TYPE (t) && TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE
9171 && REFERENCE_REF_P (r))
9172 r = TREE_OPERAND (r, 0);
9177 /* Given a function parameter pack TMPL_PARM and some function parameters
9178 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
9179 and set *SPEC_P to point at the next point in the list. */
9182 extract_fnparm_pack (tree tmpl_parm, tree *spec_p)
9184 /* Collect all of the extra "packed" parameters into an
9188 tree argpack = make_node (NONTYPE_ARGUMENT_PACK);
9189 tree argtypepack = cxx_make_type (TYPE_ARGUMENT_PACK);
9190 tree spec_parm = *spec_p;
9193 for (len = 0; spec_parm; ++len, spec_parm = TREE_CHAIN (spec_parm))
9195 && !function_parameter_expanded_from_pack_p (spec_parm, tmpl_parm))
9198 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
9199 parmvec = make_tree_vec (len);
9200 parmtypevec = make_tree_vec (len);
9201 spec_parm = *spec_p;
9202 for (i = 0; i < len; i++, spec_parm = DECL_CHAIN (spec_parm))
9204 TREE_VEC_ELT (parmvec, i) = spec_parm;
9205 TREE_VEC_ELT (parmtypevec, i) = TREE_TYPE (spec_parm);
9208 /* Build the argument packs. */
9209 SET_ARGUMENT_PACK_ARGS (argpack, parmvec);
9210 SET_ARGUMENT_PACK_ARGS (argtypepack, parmtypevec);
9211 TREE_TYPE (argpack) = argtypepack;
9212 *spec_p = spec_parm;
9217 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
9218 NONTYPE_ARGUMENT_PACK. */
9221 make_fnparm_pack (tree spec_parm)
9223 return extract_fnparm_pack (NULL_TREE, &spec_parm);
9226 /* Substitute ARGS into T, which is an pack expansion
9227 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
9228 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
9229 (if only a partial substitution could be performed) or
9230 ERROR_MARK_NODE if there was an error. */
9232 tsubst_pack_expansion (tree t, tree args, tsubst_flags_t complain,
9236 tree pack, packs = NULL_TREE;
9237 bool unsubstituted_packs = false;
9240 htab_t saved_local_specializations = NULL;
9242 gcc_assert (PACK_EXPANSION_P (t));
9243 pattern = PACK_EXPANSION_PATTERN (t);
9245 /* Determine the argument packs that will instantiate the parameter
9246 packs used in the expansion expression. While we're at it,
9247 compute the number of arguments to be expanded and make sure it
9249 for (pack = PACK_EXPANSION_PARAMETER_PACKS (t); pack;
9250 pack = TREE_CHAIN (pack))
9252 tree parm_pack = TREE_VALUE (pack);
9253 tree arg_pack = NULL_TREE;
9254 tree orig_arg = NULL_TREE;
9256 if (TREE_CODE (parm_pack) == BASES)
9258 if (BASES_DIRECT (parm_pack))
9259 return calculate_direct_bases (tsubst_expr (BASES_TYPE (parm_pack),
9260 args, complain, in_decl, false));
9262 return calculate_bases (tsubst_expr (BASES_TYPE (parm_pack),
9263 args, complain, in_decl, false));
9265 if (TREE_CODE (parm_pack) == PARM_DECL)
9267 if (!cp_unevaluated_operand)
9268 arg_pack = retrieve_local_specialization (parm_pack);
9271 /* We can't rely on local_specializations for a parameter
9272 name used later in a function declaration (such as in a
9273 late-specified return type). Even if it exists, it might
9274 have the wrong value for a recursive call. Just make a
9275 dummy decl, since it's only used for its type. */
9276 arg_pack = tsubst_decl (parm_pack, args, complain);
9277 if (arg_pack && FUNCTION_PARAMETER_PACK_P (arg_pack))
9278 /* Partial instantiation of the parm_pack, we can't build
9279 up an argument pack yet. */
9280 arg_pack = NULL_TREE;
9282 arg_pack = make_fnparm_pack (arg_pack);
9287 int level, idx, levels;
9288 template_parm_level_and_index (parm_pack, &level, &idx);
9290 levels = TMPL_ARGS_DEPTH (args);
9291 if (level <= levels)
9292 arg_pack = TMPL_ARG (args, level, idx);
9295 orig_arg = arg_pack;
9296 if (arg_pack && TREE_CODE (arg_pack) == ARGUMENT_PACK_SELECT)
9297 arg_pack = ARGUMENT_PACK_SELECT_FROM_PACK (arg_pack);
9299 if (arg_pack && !ARGUMENT_PACK_P (arg_pack))
9300 /* This can only happen if we forget to expand an argument
9301 pack somewhere else. Just return an error, silently. */
9303 result = make_tree_vec (1);
9304 TREE_VEC_ELT (result, 0) = error_mark_node;
9308 if (arg_from_parm_pack_p (arg_pack, parm_pack))
9309 /* The argument pack that the parameter maps to is just an
9310 expansion of the parameter itself, such as one would find
9311 in the implicit typedef of a class inside the class itself.
9312 Consider this parameter "unsubstituted", so that we will
9313 maintain the outer pack expansion. */
9314 arg_pack = NULL_TREE;
9319 TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack));
9321 /* Don't bother trying to do a partial substitution with
9322 incomplete packs; we'll try again after deduction. */
9323 if (ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
9328 else if (len != my_len)
9330 if (TREE_CODE (t) == TYPE_PACK_EXPANSION)
9331 error ("mismatched argument pack lengths while expanding "
9335 error ("mismatched argument pack lengths while expanding "
9338 return error_mark_node;
9341 /* Keep track of the parameter packs and their corresponding
9343 packs = tree_cons (parm_pack, arg_pack, packs);
9344 TREE_TYPE (packs) = orig_arg;
9348 /* We can't substitute for this parameter pack. */
9349 unsubstituted_packs = true;
9354 /* We cannot expand this expansion expression, because we don't have
9355 all of the argument packs we need. Substitute into the pattern
9356 and return a PACK_EXPANSION_*. The caller will need to deal with
9358 if (unsubstituted_packs)
9361 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
9362 new_pat = tsubst_expr (pattern, args, complain, in_decl,
9363 /*integral_constant_expression_p=*/false);
9365 new_pat = tsubst (pattern, args, complain, in_decl);
9366 return make_pack_expansion (new_pat);
9369 /* We could not find any argument packs that work. */
9371 return error_mark_node;
9373 if (cp_unevaluated_operand)
9375 /* We're in a late-specified return type, so create our own local
9376 specializations table; the current table is either NULL or (in the
9377 case of recursive unification) might have bindings that we don't
9378 want to use or alter. */
9379 saved_local_specializations = local_specializations;
9380 local_specializations = htab_create (37,
9381 hash_local_specialization,
9382 eq_local_specializations,
9386 /* For each argument in each argument pack, substitute into the
9388 result = make_tree_vec (len);
9389 for (i = 0; i < len; ++i)
9391 /* For parameter pack, change the substitution of the parameter
9392 pack to the ith argument in its argument pack, then expand
9394 for (pack = packs; pack; pack = TREE_CHAIN (pack))
9396 tree parm = TREE_PURPOSE (pack);
9399 /* Select the Ith argument from the pack. */
9400 if (TREE_CODE (parm) == PARM_DECL)
9404 arg = make_node (ARGUMENT_PACK_SELECT);
9405 ARGUMENT_PACK_SELECT_FROM_PACK (arg) = TREE_VALUE (pack);
9407 register_local_specialization (arg, parm);
9410 arg = retrieve_local_specialization (parm);
9415 template_parm_level_and_index (parm, &level, &idx);
9419 arg = make_node (ARGUMENT_PACK_SELECT);
9420 ARGUMENT_PACK_SELECT_FROM_PACK (arg) = TREE_VALUE (pack);
9421 /* Update the corresponding argument. */
9422 TMPL_ARG (args, level, idx) = arg;
9425 /* Re-use the ARGUMENT_PACK_SELECT. */
9426 arg = TMPL_ARG (args, level, idx);
9428 ARGUMENT_PACK_SELECT_INDEX (arg) = i;
9431 /* Substitute into the PATTERN with the altered arguments. */
9432 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
9433 TREE_VEC_ELT (result, i) =
9434 tsubst_expr (pattern, args, complain, in_decl,
9435 /*integral_constant_expression_p=*/false);
9437 TREE_VEC_ELT (result, i) = tsubst (pattern, args, complain, in_decl);
9439 if (TREE_VEC_ELT (result, i) == error_mark_node)
9441 result = error_mark_node;
9446 /* Update ARGS to restore the substitution from parameter packs to
9447 their argument packs. */
9448 for (pack = packs; pack; pack = TREE_CHAIN (pack))
9450 tree parm = TREE_PURPOSE (pack);
9452 if (TREE_CODE (parm) == PARM_DECL)
9453 register_local_specialization (TREE_TYPE (pack), parm);
9457 template_parm_level_and_index (parm, &level, &idx);
9459 /* Update the corresponding argument. */
9460 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
9461 TREE_VEC_ELT (TREE_VEC_ELT (args, level -1 ), idx) =
9464 TREE_VEC_ELT (args, idx) = TREE_TYPE (pack);
9468 if (saved_local_specializations)
9470 htab_delete (local_specializations);
9471 local_specializations = saved_local_specializations;
9477 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
9478 TMPL. We do this using DECL_PARM_INDEX, which should work even with
9479 parameter packs; all parms generated from a function parameter pack will
9480 have the same DECL_PARM_INDEX. */
9483 get_pattern_parm (tree parm, tree tmpl)
9485 tree pattern = DECL_TEMPLATE_RESULT (tmpl);
9488 if (DECL_ARTIFICIAL (parm))
9490 for (patparm = DECL_ARGUMENTS (pattern);
9491 patparm; patparm = DECL_CHAIN (patparm))
9492 if (DECL_ARTIFICIAL (patparm)
9493 && DECL_NAME (parm) == DECL_NAME (patparm))
9498 patparm = FUNCTION_FIRST_USER_PARM (DECL_TEMPLATE_RESULT (tmpl));
9499 patparm = chain_index (DECL_PARM_INDEX (parm)-1, patparm);
9500 gcc_assert (DECL_PARM_INDEX (patparm)
9501 == DECL_PARM_INDEX (parm));
9507 /* Substitute ARGS into the vector or list of template arguments T. */
9510 tsubst_template_args (tree t, tree args, tsubst_flags_t complain, tree in_decl)
9513 int len, need_new = 0, i, expanded_len_adjust = 0, out;
9516 if (t == error_mark_node)
9517 return error_mark_node;
9519 len = TREE_VEC_LENGTH (t);
9520 elts = XALLOCAVEC (tree, len);
9522 for (i = 0; i < len; i++)
9524 tree orig_arg = TREE_VEC_ELT (t, i);
9527 if (TREE_CODE (orig_arg) == TREE_VEC)
9528 new_arg = tsubst_template_args (orig_arg, args, complain, in_decl);
9529 else if (PACK_EXPANSION_P (orig_arg))
9531 /* Substitute into an expansion expression. */
9532 new_arg = tsubst_pack_expansion (orig_arg, args, complain, in_decl);
9534 if (TREE_CODE (new_arg) == TREE_VEC)
9535 /* Add to the expanded length adjustment the number of
9536 expanded arguments. We subtract one from this
9537 measurement, because the argument pack expression
9538 itself is already counted as 1 in
9539 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
9540 the argument pack is empty. */
9541 expanded_len_adjust += TREE_VEC_LENGTH (new_arg) - 1;
9543 else if (ARGUMENT_PACK_P (orig_arg))
9545 /* Substitute into each of the arguments. */
9546 new_arg = TYPE_P (orig_arg)
9547 ? cxx_make_type (TREE_CODE (orig_arg))
9548 : make_node (TREE_CODE (orig_arg));
9550 SET_ARGUMENT_PACK_ARGS (
9552 tsubst_template_args (ARGUMENT_PACK_ARGS (orig_arg),
9553 args, complain, in_decl));
9555 if (ARGUMENT_PACK_ARGS (new_arg) == error_mark_node)
9556 new_arg = error_mark_node;
9558 if (TREE_CODE (new_arg) == NONTYPE_ARGUMENT_PACK) {
9559 TREE_TYPE (new_arg) = tsubst (TREE_TYPE (orig_arg), args,
9561 TREE_CONSTANT (new_arg) = TREE_CONSTANT (orig_arg);
9563 if (TREE_TYPE (new_arg) == error_mark_node)
9564 new_arg = error_mark_node;
9568 new_arg = tsubst_template_arg (orig_arg, args, complain, in_decl);
9570 if (new_arg == error_mark_node)
9571 return error_mark_node;
9574 if (new_arg != orig_arg)
9581 /* Make space for the expanded arguments coming from template
9583 t = make_tree_vec (len + expanded_len_adjust);
9584 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
9585 arguments for a member template.
9586 In that case each TREE_VEC in ORIG_T represents a level of template
9587 arguments, and ORIG_T won't carry any non defaulted argument count.
9588 It will rather be the nested TREE_VECs that will carry one.
9589 In other words, ORIG_T carries a non defaulted argument count only
9590 if it doesn't contain any nested TREE_VEC. */
9591 if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t))
9593 int count = GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t);
9594 count += expanded_len_adjust;
9595 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (t, count);
9597 for (i = 0, out = 0; i < len; i++)
9599 if ((PACK_EXPANSION_P (TREE_VEC_ELT (orig_t, i))
9600 || ARGUMENT_PACK_P (TREE_VEC_ELT (orig_t, i)))
9601 && TREE_CODE (elts[i]) == TREE_VEC)
9605 /* Now expand the template argument pack "in place". */
9606 for (idx = 0; idx < TREE_VEC_LENGTH (elts[i]); idx++, out++)
9607 TREE_VEC_ELT (t, out) = TREE_VEC_ELT (elts[i], idx);
9611 TREE_VEC_ELT (t, out) = elts[i];
9619 /* Return the result of substituting ARGS into the template parameters
9620 given by PARMS. If there are m levels of ARGS and m + n levels of
9621 PARMS, then the result will contain n levels of PARMS. For
9622 example, if PARMS is `template <class T> template <class U>
9623 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
9624 result will be `template <int*, double, class V>'. */
9627 tsubst_template_parms (tree parms, tree args, tsubst_flags_t complain)
9632 /* When substituting into a template, we must set
9633 PROCESSING_TEMPLATE_DECL as the template parameters may be
9634 dependent if they are based on one-another, and the dependency
9635 predicates are short-circuit outside of templates. */
9636 ++processing_template_decl;
9638 for (new_parms = &r;
9639 TMPL_PARMS_DEPTH (parms) > TMPL_ARGS_DEPTH (args);
9640 new_parms = &(TREE_CHAIN (*new_parms)),
9641 parms = TREE_CHAIN (parms))
9644 make_tree_vec (TREE_VEC_LENGTH (TREE_VALUE (parms)));
9647 for (i = 0; i < TREE_VEC_LENGTH (new_vec); ++i)
9651 if (parms == error_mark_node)
9654 tuple = TREE_VEC_ELT (TREE_VALUE (parms), i);
9656 if (tuple == error_mark_node)
9659 TREE_VEC_ELT (new_vec, i) =
9660 tsubst_template_parm (tuple, args, complain);
9664 tree_cons (size_int (TMPL_PARMS_DEPTH (parms)
9665 - TMPL_ARGS_DEPTH (args)),
9666 new_vec, NULL_TREE);
9669 --processing_template_decl;
9674 /* Return the result of substituting ARGS into one template parameter
9675 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
9676 parameter and which TREE_PURPOSE is the default argument of the
9677 template parameter. */
9680 tsubst_template_parm (tree t, tree args, tsubst_flags_t complain)
9682 tree default_value, parm_decl;
9684 if (args == NULL_TREE
9686 || t == error_mark_node)
9689 gcc_assert (TREE_CODE (t) == TREE_LIST);
9691 default_value = TREE_PURPOSE (t);
9692 parm_decl = TREE_VALUE (t);
9694 parm_decl = tsubst (parm_decl, args, complain, NULL_TREE);
9695 if (TREE_CODE (parm_decl) == PARM_DECL
9696 && invalid_nontype_parm_type_p (TREE_TYPE (parm_decl), complain))
9697 parm_decl = error_mark_node;
9698 default_value = tsubst_template_arg (default_value, args,
9699 complain, NULL_TREE);
9701 return build_tree_list (default_value, parm_decl);
9704 /* Substitute the ARGS into the indicated aggregate (or enumeration)
9705 type T. If T is not an aggregate or enumeration type, it is
9706 handled as if by tsubst. IN_DECL is as for tsubst. If
9707 ENTERING_SCOPE is nonzero, T is the context for a template which
9708 we are presently tsubst'ing. Return the substituted value. */
9711 tsubst_aggr_type (tree t,
9713 tsubst_flags_t complain,
9720 switch (TREE_CODE (t))
9723 if (TYPE_PTRMEMFUNC_P (t))
9724 return tsubst (TYPE_PTRMEMFUNC_FN_TYPE (t), args, complain, in_decl);
9726 /* Else fall through. */
9729 if (TYPE_TEMPLATE_INFO (t) && uses_template_parms (t))
9734 int saved_unevaluated_operand;
9735 int saved_inhibit_evaluation_warnings;
9737 /* In "sizeof(X<I>)" we need to evaluate "I". */
9738 saved_unevaluated_operand = cp_unevaluated_operand;
9739 cp_unevaluated_operand = 0;
9740 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
9741 c_inhibit_evaluation_warnings = 0;
9743 /* First, determine the context for the type we are looking
9745 context = TYPE_CONTEXT (t);
9746 if (context && TYPE_P (context))
9748 context = tsubst_aggr_type (context, args, complain,
9749 in_decl, /*entering_scope=*/1);
9750 /* If context is a nested class inside a class template,
9751 it may still need to be instantiated (c++/33959). */
9752 context = complete_type (context);
9755 /* Then, figure out what arguments are appropriate for the
9756 type we are trying to find. For example, given:
9758 template <class T> struct S;
9759 template <class T, class U> void f(T, U) { S<U> su; }
9761 and supposing that we are instantiating f<int, double>,
9762 then our ARGS will be {int, double}, but, when looking up
9763 S we only want {double}. */
9764 argvec = tsubst_template_args (TYPE_TI_ARGS (t), args,
9766 if (argvec == error_mark_node)
9767 r = error_mark_node;
9770 r = lookup_template_class (t, argvec, in_decl, context,
9771 entering_scope, complain);
9772 r = cp_build_qualified_type_real (r, cp_type_quals (t), complain);
9775 cp_unevaluated_operand = saved_unevaluated_operand;
9776 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
9781 /* This is not a template type, so there's nothing to do. */
9785 return tsubst (t, args, complain, in_decl);
9789 /* Substitute into the default argument ARG (a default argument for
9790 FN), which has the indicated TYPE. */
9793 tsubst_default_argument (tree fn, tree type, tree arg)
9795 tree saved_class_ptr = NULL_TREE;
9796 tree saved_class_ref = NULL_TREE;
9798 /* This can happen in invalid code. */
9799 if (TREE_CODE (arg) == DEFAULT_ARG)
9802 /* This default argument came from a template. Instantiate the
9803 default argument here, not in tsubst. In the case of
9812 we must be careful to do name lookup in the scope of S<T>,
9813 rather than in the current class. */
9814 push_access_scope (fn);
9815 /* The "this" pointer is not valid in a default argument. */
9818 saved_class_ptr = current_class_ptr;
9819 cp_function_chain->x_current_class_ptr = NULL_TREE;
9820 saved_class_ref = current_class_ref;
9821 cp_function_chain->x_current_class_ref = NULL_TREE;
9824 push_deferring_access_checks(dk_no_deferred);
9825 /* The default argument expression may cause implicitly defined
9826 member functions to be synthesized, which will result in garbage
9827 collection. We must treat this situation as if we were within
9828 the body of function so as to avoid collecting live data on the
9831 arg = tsubst_expr (arg, DECL_TI_ARGS (fn),
9832 tf_warning_or_error, NULL_TREE,
9833 /*integral_constant_expression_p=*/false);
9835 pop_deferring_access_checks();
9837 /* Restore the "this" pointer. */
9840 cp_function_chain->x_current_class_ptr = saved_class_ptr;
9841 cp_function_chain->x_current_class_ref = saved_class_ref;
9844 /* Make sure the default argument is reasonable. */
9845 arg = check_default_argument (type, arg);
9847 pop_access_scope (fn);
9852 /* Substitute into all the default arguments for FN. */
9855 tsubst_default_arguments (tree fn)
9860 tmpl_args = DECL_TI_ARGS (fn);
9862 /* If this function is not yet instantiated, we certainly don't need
9863 its default arguments. */
9864 if (uses_template_parms (tmpl_args))
9866 /* Don't do this again for clones. */
9867 if (DECL_CLONED_FUNCTION_P (fn))
9870 for (arg = TYPE_ARG_TYPES (TREE_TYPE (fn));
9872 arg = TREE_CHAIN (arg))
9873 if (TREE_PURPOSE (arg))
9874 TREE_PURPOSE (arg) = tsubst_default_argument (fn,
9876 TREE_PURPOSE (arg));
9879 /* Substitute the ARGS into the T, which is a _DECL. Return the
9880 result of the substitution. Issue error and warning messages under
9881 control of COMPLAIN. */
9884 tsubst_decl (tree t, tree args, tsubst_flags_t complain)
9886 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
9887 location_t saved_loc;
9892 /* Set the filename and linenumber to improve error-reporting. */
9893 saved_loc = input_location;
9894 input_location = DECL_SOURCE_LOCATION (t);
9896 switch (TREE_CODE (t))
9900 /* We can get here when processing a member function template,
9901 member class template, or template template parameter. */
9902 tree decl = DECL_TEMPLATE_RESULT (t);
9907 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
9909 /* Template template parameter is treated here. */
9910 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9911 if (new_type == error_mark_node)
9912 RETURN (error_mark_node);
9915 DECL_CHAIN (r) = NULL_TREE;
9916 TREE_TYPE (r) = new_type;
9917 DECL_TEMPLATE_RESULT (r)
9918 = build_decl (DECL_SOURCE_LOCATION (decl),
9919 TYPE_DECL, DECL_NAME (decl), new_type);
9920 DECL_TEMPLATE_PARMS (r)
9921 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
9923 TYPE_NAME (new_type) = r;
9927 /* We might already have an instance of this template.
9928 The ARGS are for the surrounding class type, so the
9929 full args contain the tsubst'd args for the context,
9930 plus the innermost args from the template decl. */
9931 tmpl_args = DECL_CLASS_TEMPLATE_P (t)
9932 ? CLASSTYPE_TI_ARGS (TREE_TYPE (t))
9933 : DECL_TI_ARGS (DECL_TEMPLATE_RESULT (t));
9934 /* Because this is a template, the arguments will still be
9935 dependent, even after substitution. If
9936 PROCESSING_TEMPLATE_DECL is not set, the dependency
9937 predicates will short-circuit. */
9938 ++processing_template_decl;
9939 full_args = tsubst_template_args (tmpl_args, args,
9941 --processing_template_decl;
9942 if (full_args == error_mark_node)
9943 RETURN (error_mark_node);
9945 /* If this is a default template template argument,
9946 tsubst might not have changed anything. */
9947 if (full_args == tmpl_args)
9950 hash = hash_tmpl_and_args (t, full_args);
9951 spec = retrieve_specialization (t, full_args, hash);
9952 if (spec != NULL_TREE)
9958 /* Make a new template decl. It will be similar to the
9959 original, but will record the current template arguments.
9960 We also create a new function declaration, which is just
9961 like the old one, but points to this new template, rather
9962 than the old one. */
9964 gcc_assert (DECL_LANG_SPECIFIC (r) != 0);
9965 DECL_CHAIN (r) = NULL_TREE;
9967 DECL_TEMPLATE_INFO (r) = build_template_info (t, args);
9969 if (TREE_CODE (decl) == TYPE_DECL
9970 && !TYPE_DECL_ALIAS_P (decl))
9973 ++processing_template_decl;
9974 new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9975 --processing_template_decl;
9976 if (new_type == error_mark_node)
9977 RETURN (error_mark_node);
9979 TREE_TYPE (r) = new_type;
9980 CLASSTYPE_TI_TEMPLATE (new_type) = r;
9981 DECL_TEMPLATE_RESULT (r) = TYPE_MAIN_DECL (new_type);
9982 DECL_TI_ARGS (r) = CLASSTYPE_TI_ARGS (new_type);
9983 DECL_CONTEXT (r) = TYPE_CONTEXT (new_type);
9988 ++processing_template_decl;
9989 new_decl = tsubst (decl, args, complain, in_decl);
9990 --processing_template_decl;
9991 if (new_decl == error_mark_node)
9992 RETURN (error_mark_node);
9994 DECL_TEMPLATE_RESULT (r) = new_decl;
9995 DECL_TI_TEMPLATE (new_decl) = r;
9996 TREE_TYPE (r) = TREE_TYPE (new_decl);
9997 DECL_TI_ARGS (r) = DECL_TI_ARGS (new_decl);
9998 DECL_CONTEXT (r) = DECL_CONTEXT (new_decl);
10001 SET_DECL_IMPLICIT_INSTANTIATION (r);
10002 DECL_TEMPLATE_INSTANTIATIONS (r) = NULL_TREE;
10003 DECL_TEMPLATE_SPECIALIZATIONS (r) = NULL_TREE;
10005 /* The template parameters for this new template are all the
10006 template parameters for the old template, except the
10007 outermost level of parameters. */
10008 DECL_TEMPLATE_PARMS (r)
10009 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
10012 if (PRIMARY_TEMPLATE_P (t))
10013 DECL_PRIMARY_TEMPLATE (r) = r;
10015 if (TREE_CODE (decl) != TYPE_DECL)
10016 /* Record this non-type partial instantiation. */
10017 register_specialization (r, t,
10018 DECL_TI_ARGS (DECL_TEMPLATE_RESULT (r)),
10023 case FUNCTION_DECL:
10026 tree argvec = NULL_TREE;
10034 /* Nobody should be tsubst'ing into non-template functions. */
10035 gcc_assert (DECL_TEMPLATE_INFO (t) != NULL_TREE);
10037 if (TREE_CODE (DECL_TI_TEMPLATE (t)) == TEMPLATE_DECL)
10042 /* If T is not dependent, just return it. We have to
10043 increment PROCESSING_TEMPLATE_DECL because
10044 value_dependent_expression_p assumes that nothing is
10045 dependent when PROCESSING_TEMPLATE_DECL is zero. */
10046 ++processing_template_decl;
10047 dependent_p = value_dependent_expression_p (t);
10048 --processing_template_decl;
10052 /* Calculate the most general template of which R is a
10053 specialization, and the complete set of arguments used to
10055 gen_tmpl = most_general_template (DECL_TI_TEMPLATE (t));
10056 argvec = tsubst_template_args (DECL_TI_ARGS
10057 (DECL_TEMPLATE_RESULT
10058 (DECL_TI_TEMPLATE (t))),
10059 args, complain, in_decl);
10060 if (argvec == error_mark_node)
10061 RETURN (error_mark_node);
10063 /* Check to see if we already have this specialization. */
10064 hash = hash_tmpl_and_args (gen_tmpl, argvec);
10065 spec = retrieve_specialization (gen_tmpl, argvec, hash);
10073 /* We can see more levels of arguments than parameters if
10074 there was a specialization of a member template, like
10077 template <class T> struct S { template <class U> void f(); }
10078 template <> template <class U> void S<int>::f(U);
10080 Here, we'll be substituting into the specialization,
10081 because that's where we can find the code we actually
10082 want to generate, but we'll have enough arguments for
10083 the most general template.
10085 We also deal with the peculiar case:
10087 template <class T> struct S {
10088 template <class U> friend void f();
10090 template <class U> void f() {}
10092 template void f<double>();
10094 Here, the ARGS for the instantiation of will be {int,
10095 double}. But, we only need as many ARGS as there are
10096 levels of template parameters in CODE_PATTERN. We are
10097 careful not to get fooled into reducing the ARGS in
10100 template <class T> struct S { template <class U> void f(U); }
10101 template <class T> template <> void S<T>::f(int) {}
10103 which we can spot because the pattern will be a
10104 specialization in this case. */
10105 args_depth = TMPL_ARGS_DEPTH (args);
10107 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (t)));
10108 if (args_depth > parms_depth
10109 && !DECL_TEMPLATE_SPECIALIZATION (t))
10110 args = get_innermost_template_args (args, parms_depth);
10114 /* This special case arises when we have something like this:
10116 template <class T> struct S {
10117 friend void f<int>(int, double);
10120 Here, the DECL_TI_TEMPLATE for the friend declaration
10121 will be an IDENTIFIER_NODE. We are being called from
10122 tsubst_friend_function, and we want only to create a
10123 new decl (R) with appropriate types so that we can call
10124 determine_specialization. */
10125 gen_tmpl = NULL_TREE;
10128 if (DECL_CLASS_SCOPE_P (t))
10130 if (DECL_NAME (t) == constructor_name (DECL_CONTEXT (t)))
10134 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args,
10135 complain, t, /*entering_scope=*/1);
10140 ctx = DECL_CONTEXT (t);
10142 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10143 if (type == error_mark_node)
10144 RETURN (error_mark_node);
10146 /* We do NOT check for matching decls pushed separately at this
10147 point, as they may not represent instantiations of this
10148 template, and in any case are considered separate under the
10151 DECL_USE_TEMPLATE (r) = 0;
10152 TREE_TYPE (r) = type;
10153 /* Clear out the mangled name and RTL for the instantiation. */
10154 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
10155 SET_DECL_RTL (r, NULL);
10156 /* Leave DECL_INITIAL set on deleted instantiations. */
10157 if (!DECL_DELETED_FN (r))
10158 DECL_INITIAL (r) = NULL_TREE;
10159 DECL_CONTEXT (r) = ctx;
10161 if (member && DECL_CONV_FN_P (r))
10162 /* Type-conversion operator. Reconstruct the name, in
10163 case it's the name of one of the template's parameters. */
10164 DECL_NAME (r) = mangle_conv_op_name_for_type (TREE_TYPE (type));
10166 DECL_ARGUMENTS (r) = tsubst (DECL_ARGUMENTS (t), args,
10168 DECL_RESULT (r) = NULL_TREE;
10170 TREE_STATIC (r) = 0;
10171 TREE_PUBLIC (r) = TREE_PUBLIC (t);
10172 DECL_EXTERNAL (r) = 1;
10173 /* If this is an instantiation of a function with internal
10174 linkage, we already know what object file linkage will be
10175 assigned to the instantiation. */
10176 DECL_INTERFACE_KNOWN (r) = !TREE_PUBLIC (r);
10177 DECL_DEFER_OUTPUT (r) = 0;
10178 DECL_CHAIN (r) = NULL_TREE;
10179 DECL_PENDING_INLINE_INFO (r) = 0;
10180 DECL_PENDING_INLINE_P (r) = 0;
10181 DECL_SAVED_TREE (r) = NULL_TREE;
10182 DECL_STRUCT_FUNCTION (r) = NULL;
10184 /* We'll re-clone as appropriate in instantiate_template. */
10185 DECL_CLONED_FUNCTION (r) = NULL_TREE;
10187 /* If we aren't complaining now, return on error before we register
10188 the specialization so that we'll complain eventually. */
10189 if ((complain & tf_error) == 0
10190 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
10191 && !grok_op_properties (r, /*complain=*/false))
10192 RETURN (error_mark_node);
10194 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
10195 this in the special friend case mentioned above where
10196 GEN_TMPL is NULL. */
10199 DECL_TEMPLATE_INFO (r)
10200 = build_template_info (gen_tmpl, argvec);
10201 SET_DECL_IMPLICIT_INSTANTIATION (r);
10202 register_specialization (r, gen_tmpl, argvec, false, hash);
10204 /* We're not supposed to instantiate default arguments
10205 until they are called, for a template. But, for a
10208 template <class T> void f ()
10209 { extern void g(int i = T()); }
10211 we should do the substitution when the template is
10212 instantiated. We handle the member function case in
10213 instantiate_class_template since the default arguments
10214 might refer to other members of the class. */
10216 && !PRIMARY_TEMPLATE_P (gen_tmpl)
10217 && !uses_template_parms (argvec))
10218 tsubst_default_arguments (r);
10221 DECL_TEMPLATE_INFO (r) = NULL_TREE;
10223 /* Copy the list of befriending classes. */
10224 for (friends = &DECL_BEFRIENDING_CLASSES (r);
10226 friends = &TREE_CHAIN (*friends))
10228 *friends = copy_node (*friends);
10229 TREE_VALUE (*friends) = tsubst (TREE_VALUE (*friends),
10234 if (DECL_CONSTRUCTOR_P (r) || DECL_DESTRUCTOR_P (r))
10236 maybe_retrofit_in_chrg (r);
10237 if (DECL_CONSTRUCTOR_P (r))
10238 grok_ctor_properties (ctx, r);
10239 /* If this is an instantiation of a member template, clone it.
10240 If it isn't, that'll be handled by
10241 clone_constructors_and_destructors. */
10242 if (PRIMARY_TEMPLATE_P (gen_tmpl))
10243 clone_function_decl (r, /*update_method_vec_p=*/0);
10245 else if ((complain & tf_error) != 0
10246 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
10247 && !grok_op_properties (r, /*complain=*/true))
10248 RETURN (error_mark_node);
10250 if (DECL_FRIEND_P (t) && DECL_FRIEND_CONTEXT (t))
10251 SET_DECL_FRIEND_CONTEXT (r,
10252 tsubst (DECL_FRIEND_CONTEXT (t),
10253 args, complain, in_decl));
10255 /* Possibly limit visibility based on template args. */
10256 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
10257 if (DECL_VISIBILITY_SPECIFIED (t))
10259 DECL_VISIBILITY_SPECIFIED (r) = 0;
10260 DECL_ATTRIBUTES (r)
10261 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
10263 determine_visibility (r);
10264 if (DECL_DEFAULTED_OUTSIDE_CLASS_P (r)
10265 && !processing_template_decl)
10266 defaulted_late_check (r);
10268 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
10269 args, complain, in_decl);
10275 tree type = NULL_TREE;
10277 tree expanded_types = NULL_TREE;
10278 tree prev_r = NULL_TREE;
10279 tree first_r = NULL_TREE;
10281 if (FUNCTION_PARAMETER_PACK_P (t))
10283 /* If there is a local specialization that isn't a
10284 parameter pack, it means that we're doing a "simple"
10285 substitution from inside tsubst_pack_expansion. Just
10286 return the local specialization (which will be a single
10288 tree spec = retrieve_local_specialization (t);
10290 && TREE_CODE (spec) == PARM_DECL
10291 && TREE_CODE (TREE_TYPE (spec)) != TYPE_PACK_EXPANSION)
10294 /* Expand the TYPE_PACK_EXPANSION that provides the types for
10295 the parameters in this function parameter pack. */
10296 expanded_types = tsubst_pack_expansion (TREE_TYPE (t), args,
10297 complain, in_decl);
10298 if (TREE_CODE (expanded_types) == TREE_VEC)
10300 len = TREE_VEC_LENGTH (expanded_types);
10302 /* Zero-length parameter packs are boring. Just substitute
10305 RETURN (tsubst (TREE_CHAIN (t), args, complain,
10310 /* All we did was update the type. Make a note of that. */
10311 type = expanded_types;
10312 expanded_types = NULL_TREE;
10316 /* Loop through all of the parameter's we'll build. When T is
10317 a function parameter pack, LEN is the number of expanded
10318 types in EXPANDED_TYPES; otherwise, LEN is 1. */
10320 for (i = 0; i < len; ++i)
10324 if (DECL_TEMPLATE_PARM_P (t))
10325 SET_DECL_TEMPLATE_PARM_P (r);
10327 if (expanded_types)
10328 /* We're on the Ith parameter of the function parameter
10331 /* An argument of a function parameter pack is not a parameter
10333 FUNCTION_PARAMETER_PACK_P (r) = false;
10335 /* Get the Ith type. */
10336 type = TREE_VEC_ELT (expanded_types, i);
10339 /* Rename the parameter to include the index. */
10341 make_ith_pack_parameter_name (DECL_NAME (r), i);
10344 /* We're dealing with a normal parameter. */
10345 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10347 type = type_decays_to (type);
10348 TREE_TYPE (r) = type;
10349 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
10351 if (DECL_INITIAL (r))
10353 if (TREE_CODE (DECL_INITIAL (r)) != TEMPLATE_PARM_INDEX)
10354 DECL_INITIAL (r) = TREE_TYPE (r);
10356 DECL_INITIAL (r) = tsubst (DECL_INITIAL (r), args,
10357 complain, in_decl);
10360 DECL_CONTEXT (r) = NULL_TREE;
10362 if (!DECL_TEMPLATE_PARM_P (r))
10363 DECL_ARG_TYPE (r) = type_passed_as (type);
10365 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
10366 args, complain, in_decl);
10368 /* Keep track of the first new parameter we
10369 generate. That's what will be returned to the
10374 /* Build a proper chain of parameters when substituting
10375 into a function parameter pack. */
10377 DECL_CHAIN (prev_r) = r;
10380 if (DECL_CHAIN (t))
10381 DECL_CHAIN (r) = tsubst (DECL_CHAIN (t), args,
10382 complain, DECL_CHAIN (t));
10384 /* FIRST_R contains the start of the chain we've built. */
10394 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10395 if (type == error_mark_node)
10396 RETURN (error_mark_node);
10397 TREE_TYPE (r) = type;
10398 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
10400 if (DECL_C_BIT_FIELD (r))
10401 /* For bit-fields, DECL_INITIAL gives the number of bits. For
10402 non-bit-fields DECL_INITIAL is a non-static data member
10403 initializer, which gets deferred instantiation. */
10405 = tsubst_expr (DECL_INITIAL (t), args,
10407 /*integral_constant_expression_p=*/true);
10408 else if (DECL_INITIAL (t))
10410 /* Set up DECL_TEMPLATE_INFO so that we can get at the
10411 NSDMI in perform_member_init. Still set DECL_INITIAL
10412 so that we know there is one. */
10413 DECL_INITIAL (r) = void_zero_node;
10414 gcc_assert (DECL_LANG_SPECIFIC (r) == NULL);
10415 retrofit_lang_decl (r);
10416 DECL_TEMPLATE_INFO (r) = build_template_info (t, args);
10418 /* We don't have to set DECL_CONTEXT here; it is set by
10419 finish_member_declaration. */
10420 DECL_CHAIN (r) = NULL_TREE;
10421 if (VOID_TYPE_P (type))
10422 error ("instantiation of %q+D as type %qT", r, type);
10424 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
10425 args, complain, in_decl);
10430 /* We reach here only for member using decls. */
10431 if (DECL_DEPENDENT_P (t))
10433 r = do_class_using_decl
10434 (tsubst_copy (USING_DECL_SCOPE (t), args, complain, in_decl),
10435 tsubst_copy (DECL_NAME (t), args, complain, in_decl));
10437 r = error_mark_node;
10440 TREE_PROTECTED (r) = TREE_PROTECTED (t);
10441 TREE_PRIVATE (r) = TREE_PRIVATE (t);
10447 DECL_CHAIN (r) = NULL_TREE;
10454 tree argvec = NULL_TREE;
10455 tree gen_tmpl = NULL_TREE;
10457 tree tmpl = NULL_TREE;
10459 tree type = NULL_TREE;
10462 if (TREE_CODE (t) == TYPE_DECL
10463 && t == TYPE_MAIN_DECL (TREE_TYPE (t)))
10465 /* If this is the canonical decl, we don't have to
10466 mess with instantiations, and often we can't (for
10467 typename, template type parms and such). Note that
10468 TYPE_NAME is not correct for the above test if
10469 we've copied the type for a typedef. */
10470 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10471 if (type == error_mark_node)
10472 RETURN (error_mark_node);
10473 r = TYPE_NAME (type);
10477 /* Check to see if we already have the specialization we
10480 if (DECL_CLASS_SCOPE_P (t) || DECL_NAMESPACE_SCOPE_P (t))
10482 /* T is a static data member or namespace-scope entity.
10483 We have to substitute into namespace-scope variables
10484 (even though such entities are never templates) because
10487 template <class T> void f() { extern T t; }
10489 where the entity referenced is not known until
10490 instantiation time. */
10492 ctx = DECL_CONTEXT (t);
10493 if (DECL_CLASS_SCOPE_P (t))
10495 ctx = tsubst_aggr_type (ctx, args,
10497 in_decl, /*entering_scope=*/1);
10498 /* If CTX is unchanged, then T is in fact the
10499 specialization we want. That situation occurs when
10500 referencing a static data member within in its own
10501 class. We can use pointer equality, rather than
10502 same_type_p, because DECL_CONTEXT is always
10504 if (ctx == DECL_CONTEXT (t)
10505 && (TREE_CODE (t) != TYPE_DECL
10506 /* ... unless T is a member template; in which
10507 case our caller can be willing to create a
10508 specialization of that template represented
10510 || !(DECL_TI_TEMPLATE (t)
10511 && DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (t)))))
10517 tmpl = DECL_TI_TEMPLATE (t);
10518 gen_tmpl = most_general_template (tmpl);
10519 argvec = tsubst (DECL_TI_ARGS (t), args, complain, in_decl);
10520 hash = hash_tmpl_and_args (gen_tmpl, argvec);
10521 spec = retrieve_specialization (gen_tmpl, argvec, hash);
10526 /* A local variable. */
10528 /* Subsequent calls to pushdecl will fill this in. */
10530 spec = retrieve_local_specialization (t);
10532 /* If we already have the specialization we need, there is
10533 nothing more to do. */
10540 /* Create a new node for the specialization we need. */
10542 if (type == NULL_TREE)
10544 if (is_typedef_decl (t))
10545 type = DECL_ORIGINAL_TYPE (t);
10547 type = TREE_TYPE (t);
10548 if (TREE_CODE (t) == VAR_DECL && VAR_HAD_UNKNOWN_BOUND (t))
10549 type = strip_array_domain (type);
10550 type = tsubst (type, args, complain, in_decl);
10552 if (TREE_CODE (r) == VAR_DECL)
10554 /* Even if the original location is out of scope, the
10555 newly substituted one is not. */
10556 DECL_DEAD_FOR_LOCAL (r) = 0;
10557 DECL_INITIALIZED_P (r) = 0;
10558 DECL_TEMPLATE_INSTANTIATED (r) = 0;
10559 if (type == error_mark_node)
10560 RETURN (error_mark_node);
10561 if (TREE_CODE (type) == FUNCTION_TYPE)
10563 /* It may seem that this case cannot occur, since:
10568 declares a function, not a variable. However:
10571 template <typename T> void g() { T t; }
10572 template void g<f>();
10574 is an attempt to declare a variable with function
10576 error ("variable %qD has function type",
10577 /* R is not yet sufficiently initialized, so we
10578 just use its name. */
10580 RETURN (error_mark_node);
10582 type = complete_type (type);
10583 /* Wait until cp_finish_decl to set this again, to handle
10584 circular dependency (template/instantiate6.C). */
10585 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r) = 0;
10586 type = check_var_type (DECL_NAME (r), type);
10588 if (DECL_HAS_VALUE_EXPR_P (t))
10590 tree ve = DECL_VALUE_EXPR (t);
10591 ve = tsubst_expr (ve, args, complain, in_decl,
10592 /*constant_expression_p=*/false);
10593 if (REFERENCE_REF_P (ve))
10595 gcc_assert (TREE_CODE (type) == REFERENCE_TYPE);
10596 ve = TREE_OPERAND (ve, 0);
10598 SET_DECL_VALUE_EXPR (r, ve);
10601 else if (DECL_SELF_REFERENCE_P (t))
10602 SET_DECL_SELF_REFERENCE_P (r);
10603 TREE_TYPE (r) = type;
10604 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
10605 DECL_CONTEXT (r) = ctx;
10606 /* Clear out the mangled name and RTL for the instantiation. */
10607 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
10608 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
10609 SET_DECL_RTL (r, NULL);
10610 /* The initializer must not be expanded until it is required;
10611 see [temp.inst]. */
10612 DECL_INITIAL (r) = NULL_TREE;
10613 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
10614 SET_DECL_RTL (r, NULL);
10615 DECL_SIZE (r) = DECL_SIZE_UNIT (r) = 0;
10616 if (TREE_CODE (r) == VAR_DECL)
10618 /* Possibly limit visibility based on template args. */
10619 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
10620 if (DECL_VISIBILITY_SPECIFIED (t))
10622 DECL_VISIBILITY_SPECIFIED (r) = 0;
10623 DECL_ATTRIBUTES (r)
10624 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
10626 determine_visibility (r);
10631 /* A static data member declaration is always marked
10632 external when it is declared in-class, even if an
10633 initializer is present. We mimic the non-template
10634 processing here. */
10635 DECL_EXTERNAL (r) = 1;
10637 register_specialization (r, gen_tmpl, argvec, false, hash);
10638 DECL_TEMPLATE_INFO (r) = build_template_info (tmpl, argvec);
10639 SET_DECL_IMPLICIT_INSTANTIATION (r);
10641 else if (cp_unevaluated_operand)
10643 /* We're substituting this var in a decltype outside of its
10644 scope, such as for a lambda return type. Don't add it to
10645 local_specializations, do perform auto deduction. */
10646 tree auto_node = type_uses_auto (type);
10650 = tsubst_expr (DECL_INITIAL (t), args, complain, in_decl,
10651 /*constant_expression_p=*/false);
10652 init = resolve_nondeduced_context (init);
10653 TREE_TYPE (r) = type
10654 = do_auto_deduction (type, init, auto_node);
10658 register_local_specialization (r, t);
10660 DECL_CHAIN (r) = NULL_TREE;
10662 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r),
10664 args, complain, in_decl);
10666 /* Preserve a typedef that names a type. */
10667 if (is_typedef_decl (r))
10669 DECL_ORIGINAL_TYPE (r) = NULL_TREE;
10670 set_underlying_type (r);
10673 layout_decl (r, 0);
10678 gcc_unreachable ();
10683 /* Restore the file and line information. */
10684 input_location = saved_loc;
10689 /* Substitute into the ARG_TYPES of a function type. */
10692 tsubst_arg_types (tree arg_types,
10694 tsubst_flags_t complain,
10697 tree remaining_arg_types;
10698 tree type = NULL_TREE;
10700 tree expanded_args = NULL_TREE;
10703 if (!arg_types || arg_types == void_list_node)
10706 remaining_arg_types = tsubst_arg_types (TREE_CHAIN (arg_types),
10707 args, complain, in_decl);
10708 if (remaining_arg_types == error_mark_node)
10709 return error_mark_node;
10711 if (PACK_EXPANSION_P (TREE_VALUE (arg_types)))
10713 /* For a pack expansion, perform substitution on the
10714 entire expression. Later on, we'll handle the arguments
10716 expanded_args = tsubst_pack_expansion (TREE_VALUE (arg_types),
10717 args, complain, in_decl);
10719 if (TREE_CODE (expanded_args) == TREE_VEC)
10720 /* So that we'll spin through the parameters, one by one. */
10721 i = TREE_VEC_LENGTH (expanded_args);
10724 /* We only partially substituted into the parameter
10725 pack. Our type is TYPE_PACK_EXPANSION. */
10726 type = expanded_args;
10727 expanded_args = NULL_TREE;
10735 type = TREE_VEC_ELT (expanded_args, i);
10737 type = tsubst (TREE_VALUE (arg_types), args, complain, in_decl);
10739 if (type == error_mark_node)
10740 return error_mark_node;
10741 if (VOID_TYPE_P (type))
10743 if (complain & tf_error)
10745 error ("invalid parameter type %qT", type);
10747 error ("in declaration %q+D", in_decl);
10749 return error_mark_node;
10752 /* Do array-to-pointer, function-to-pointer conversion, and ignore
10753 top-level qualifiers as required. */
10754 type = cv_unqualified (type_decays_to (type));
10756 /* We do not substitute into default arguments here. The standard
10757 mandates that they be instantiated only when needed, which is
10758 done in build_over_call. */
10759 default_arg = TREE_PURPOSE (arg_types);
10761 if (default_arg && TREE_CODE (default_arg) == DEFAULT_ARG)
10763 /* We've instantiated a template before its default arguments
10764 have been parsed. This can happen for a nested template
10765 class, and is not an error unless we require the default
10766 argument in a call of this function. */
10767 remaining_arg_types =
10768 tree_cons (default_arg, type, remaining_arg_types);
10769 VEC_safe_push (tree, gc, DEFARG_INSTANTIATIONS (default_arg),
10770 remaining_arg_types);
10773 remaining_arg_types =
10774 hash_tree_cons (default_arg, type, remaining_arg_types);
10777 return remaining_arg_types;
10780 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
10781 *not* handle the exception-specification for FNTYPE, because the
10782 initial substitution of explicitly provided template parameters
10783 during argument deduction forbids substitution into the
10784 exception-specification:
10788 All references in the function type of the function template to the
10789 corresponding template parameters are replaced by the specified tem-
10790 plate argument values. If a substitution in a template parameter or
10791 in the function type of the function template results in an invalid
10792 type, type deduction fails. [Note: The equivalent substitution in
10793 exception specifications is done only when the function is instanti-
10794 ated, at which point a program is ill-formed if the substitution
10795 results in an invalid type.] */
10798 tsubst_function_type (tree t,
10800 tsubst_flags_t complain,
10807 /* The TYPE_CONTEXT is not used for function/method types. */
10808 gcc_assert (TYPE_CONTEXT (t) == NULL_TREE);
10810 /* Substitute the return type. */
10811 return_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10812 if (return_type == error_mark_node)
10813 return error_mark_node;
10814 /* The standard does not presently indicate that creation of a
10815 function type with an invalid return type is a deduction failure.
10816 However, that is clearly analogous to creating an array of "void"
10817 or a reference to a reference. This is core issue #486. */
10818 if (TREE_CODE (return_type) == ARRAY_TYPE
10819 || TREE_CODE (return_type) == FUNCTION_TYPE)
10821 if (complain & tf_error)
10823 if (TREE_CODE (return_type) == ARRAY_TYPE)
10824 error ("function returning an array");
10826 error ("function returning a function");
10828 return error_mark_node;
10831 /* Substitute the argument types. */
10832 arg_types = tsubst_arg_types (TYPE_ARG_TYPES (t), args,
10833 complain, in_decl);
10834 if (arg_types == error_mark_node)
10835 return error_mark_node;
10837 /* Construct a new type node and return it. */
10838 if (TREE_CODE (t) == FUNCTION_TYPE)
10840 fntype = build_function_type (return_type, arg_types);
10841 fntype = apply_memfn_quals (fntype, type_memfn_quals (t));
10845 tree r = TREE_TYPE (TREE_VALUE (arg_types));
10846 if (! MAYBE_CLASS_TYPE_P (r))
10850 Type deduction may fail for any of the following
10853 -- Attempting to create "pointer to member of T" when T
10854 is not a class type. */
10855 if (complain & tf_error)
10856 error ("creating pointer to member function of non-class type %qT",
10858 return error_mark_node;
10861 fntype = build_method_type_directly (r, return_type,
10862 TREE_CHAIN (arg_types));
10864 fntype = cp_build_type_attribute_variant (fntype, TYPE_ATTRIBUTES (t));
10869 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
10870 ARGS into that specification, and return the substituted
10871 specification. If there is no specification, return NULL_TREE. */
10874 tsubst_exception_specification (tree fntype,
10876 tsubst_flags_t complain,
10883 specs = TYPE_RAISES_EXCEPTIONS (fntype);
10884 new_specs = NULL_TREE;
10885 if (specs && TREE_PURPOSE (specs))
10887 /* A noexcept-specifier. */
10888 tree expr = TREE_PURPOSE (specs);
10889 if (expr == boolean_true_node || expr == boolean_false_node)
10893 /* Defer instantiation of noexcept-specifiers to avoid
10894 excessive instantiations (c++/49107). */
10895 new_specs = make_node (DEFERRED_NOEXCEPT);
10896 if (DEFERRED_NOEXCEPT_SPEC_P (specs))
10898 /* We already partially instantiated this member template,
10899 so combine the new args with the old. */
10900 DEFERRED_NOEXCEPT_PATTERN (new_specs)
10901 = DEFERRED_NOEXCEPT_PATTERN (expr);
10902 DEFERRED_NOEXCEPT_ARGS (new_specs)
10903 = add_to_template_args (DEFERRED_NOEXCEPT_ARGS (expr), args);
10907 DEFERRED_NOEXCEPT_PATTERN (new_specs) = expr;
10908 DEFERRED_NOEXCEPT_ARGS (new_specs) = args;
10912 new_specs = tsubst_copy_and_build
10913 (expr, args, complain, in_decl, /*function_p=*/false,
10914 /*integral_constant_expression_p=*/true);
10915 new_specs = build_noexcept_spec (new_specs, complain);
10919 if (! TREE_VALUE (specs))
10926 tree expanded_specs = NULL_TREE;
10928 if (PACK_EXPANSION_P (TREE_VALUE (specs)))
10930 /* Expand the pack expansion type. */
10931 expanded_specs = tsubst_pack_expansion (TREE_VALUE (specs),
10935 if (expanded_specs == error_mark_node)
10936 return error_mark_node;
10937 else if (TREE_CODE (expanded_specs) == TREE_VEC)
10938 len = TREE_VEC_LENGTH (expanded_specs);
10941 /* We're substituting into a member template, so
10942 we got a TYPE_PACK_EXPANSION back. Add that
10943 expansion and move on. */
10944 gcc_assert (TREE_CODE (expanded_specs)
10945 == TYPE_PACK_EXPANSION);
10946 new_specs = add_exception_specifier (new_specs,
10949 specs = TREE_CHAIN (specs);
10954 for (i = 0; i < len; ++i)
10956 if (expanded_specs)
10957 spec = TREE_VEC_ELT (expanded_specs, i);
10959 spec = tsubst (TREE_VALUE (specs), args, complain, in_decl);
10960 if (spec == error_mark_node)
10962 new_specs = add_exception_specifier (new_specs, spec,
10966 specs = TREE_CHAIN (specs);
10972 /* Take the tree structure T and replace template parameters used
10973 therein with the argument vector ARGS. IN_DECL is an associated
10974 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
10975 Issue error and warning messages under control of COMPLAIN. Note
10976 that we must be relatively non-tolerant of extensions here, in
10977 order to preserve conformance; if we allow substitutions that
10978 should not be allowed, we may allow argument deductions that should
10979 not succeed, and therefore report ambiguous overload situations
10980 where there are none. In theory, we could allow the substitution,
10981 but indicate that it should have failed, and allow our caller to
10982 make sure that the right thing happens, but we don't try to do this
10985 This function is used for dealing with types, decls and the like;
10986 for expressions, use tsubst_expr or tsubst_copy. */
10989 tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl)
10991 enum tree_code code;
10992 tree type, r = NULL_TREE;
10994 if (t == NULL_TREE || t == error_mark_node
10995 || t == integer_type_node
10996 || t == void_type_node
10997 || t == char_type_node
10998 || t == unknown_type_node
10999 || TREE_CODE (t) == NAMESPACE_DECL
11000 || TREE_CODE (t) == TRANSLATION_UNIT_DECL)
11004 return tsubst_decl (t, args, complain);
11006 if (args == NULL_TREE)
11009 code = TREE_CODE (t);
11011 if (code == IDENTIFIER_NODE)
11012 type = IDENTIFIER_TYPE_VALUE (t);
11014 type = TREE_TYPE (t);
11016 gcc_assert (type != unknown_type_node);
11018 /* Reuse typedefs. We need to do this to handle dependent attributes,
11019 such as attribute aligned. */
11021 && typedef_variant_p (t))
11023 tree decl = TYPE_NAME (t);
11025 if (TYPE_DECL_ALIAS_P (decl)
11026 && DECL_LANG_SPECIFIC (decl)
11027 && DECL_TEMPLATE_INFO (decl)
11028 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (decl)))
11030 /* DECL represents an alias template and we want to
11031 instantiate it. Let's substitute our arguments for the
11032 template parameters into the declaration and get the
11034 r = tsubst (decl, args, complain, decl);
11036 else if (DECL_CLASS_SCOPE_P (decl)
11037 && CLASSTYPE_TEMPLATE_INFO (DECL_CONTEXT (decl))
11038 && uses_template_parms (DECL_CONTEXT (decl)))
11040 tree tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
11041 tree gen_args = tsubst (DECL_TI_ARGS (decl), args, complain, in_decl);
11042 r = retrieve_specialization (tmpl, gen_args, 0);
11044 else if (DECL_FUNCTION_SCOPE_P (decl)
11045 && DECL_TEMPLATE_INFO (DECL_CONTEXT (decl))
11046 && uses_template_parms (DECL_TI_ARGS (DECL_CONTEXT (decl))))
11047 r = retrieve_local_specialization (decl);
11049 /* The typedef is from a non-template context. */
11055 r = cp_build_qualified_type_real
11056 (r, cp_type_quals (t) | cp_type_quals (r),
11057 complain | tf_ignore_bad_quals);
11060 /* Else we must be instantiating the typedef, so fall through. */
11064 && code != TYPENAME_TYPE
11065 && code != TEMPLATE_TYPE_PARM
11066 && code != IDENTIFIER_NODE
11067 && code != FUNCTION_TYPE
11068 && code != METHOD_TYPE)
11069 type = tsubst (type, args, complain, in_decl);
11070 if (type == error_mark_node)
11071 return error_mark_node;
11077 case ENUMERAL_TYPE:
11078 return tsubst_aggr_type (t, args, complain, in_decl,
11079 /*entering_scope=*/0);
11082 case IDENTIFIER_NODE:
11093 if (t == integer_type_node)
11096 if (TREE_CODE (TYPE_MIN_VALUE (t)) == INTEGER_CST
11097 && TREE_CODE (TYPE_MAX_VALUE (t)) == INTEGER_CST)
11101 tree max, omax = TREE_OPERAND (TYPE_MAX_VALUE (t), 0);
11103 max = tsubst_expr (omax, args, complain, in_decl,
11104 /*integral_constant_expression_p=*/false);
11106 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
11108 if (TREE_CODE (max) == NOP_EXPR
11109 && TREE_SIDE_EFFECTS (omax)
11110 && !TREE_TYPE (max))
11111 TREE_TYPE (max) = TREE_TYPE (TREE_OPERAND (max, 0));
11113 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
11114 with TREE_SIDE_EFFECTS that indicates this is not an integral
11115 constant expression. */
11116 if (processing_template_decl
11117 && TREE_SIDE_EFFECTS (omax) && TREE_CODE (omax) == NOP_EXPR)
11119 gcc_assert (TREE_CODE (max) == NOP_EXPR);
11120 TREE_SIDE_EFFECTS (max) = 1;
11123 return compute_array_index_type (NULL_TREE, max, complain);
11126 case TEMPLATE_TYPE_PARM:
11127 case TEMPLATE_TEMPLATE_PARM:
11128 case BOUND_TEMPLATE_TEMPLATE_PARM:
11129 case TEMPLATE_PARM_INDEX:
11134 tree arg = NULL_TREE;
11138 gcc_assert (TREE_VEC_LENGTH (args) > 0);
11139 template_parm_level_and_index (t, &level, &idx);
11141 levels = TMPL_ARGS_DEPTH (args);
11142 if (level <= levels)
11144 arg = TMPL_ARG (args, level, idx);
11146 if (arg && TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
11147 /* See through ARGUMENT_PACK_SELECT arguments. */
11148 arg = ARGUMENT_PACK_SELECT_ARG (arg);
11151 if (arg == error_mark_node)
11152 return error_mark_node;
11153 else if (arg != NULL_TREE)
11155 if (ARGUMENT_PACK_P (arg))
11156 /* If ARG is an argument pack, we don't actually want to
11157 perform a substitution here, because substitutions
11158 for argument packs are only done
11159 element-by-element. We can get to this point when
11160 substituting the type of a non-type template
11161 parameter pack, when that type actually contains
11162 template parameter packs from an outer template, e.g.,
11164 template<typename... Types> struct A {
11165 template<Types... Values> struct B { };
11169 if (code == TEMPLATE_TYPE_PARM)
11172 gcc_assert (TYPE_P (arg));
11174 quals = cp_type_quals (arg) | cp_type_quals (t);
11176 return cp_build_qualified_type_real
11177 (arg, quals, complain | tf_ignore_bad_quals);
11179 else if (code == BOUND_TEMPLATE_TEMPLATE_PARM)
11181 /* We are processing a type constructed from a
11182 template template parameter. */
11183 tree argvec = tsubst (TYPE_TI_ARGS (t),
11184 args, complain, in_decl);
11185 if (argvec == error_mark_node)
11186 return error_mark_node;
11188 gcc_assert (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
11189 || TREE_CODE (arg) == TEMPLATE_DECL
11190 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE);
11192 if (TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE)
11193 /* Consider this code:
11195 template <template <class> class Template>
11197 template <class Arg> using Bind = Template<Arg>;
11200 template <template <class> class Template, class Arg>
11201 using Instantiate = Template<Arg>; //#0
11203 template <template <class> class Template,
11206 Instantiate<Internal<Template>::template Bind,
11209 When #1 is parsed, the
11210 BOUND_TEMPLATE_TEMPLATE_PARM representing the
11211 parameter `Template' in #0 matches the
11212 UNBOUND_CLASS_TEMPLATE representing the argument
11213 `Internal<Template>::template Bind'; We then want
11214 to assemble the type `Bind<Argument>' that can't
11215 be fully created right now, because
11216 `Internal<Template>' not being complete, the Bind
11217 template cannot be looked up in that context. So
11218 we need to "store" `Bind<Argument>' for later
11219 when the context of Bind becomes complete. Let's
11220 store that in a TYPENAME_TYPE. */
11221 return make_typename_type (TYPE_CONTEXT (arg),
11222 build_nt (TEMPLATE_ID_EXPR,
11223 TYPE_IDENTIFIER (arg),
11228 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
11229 are resolving nested-types in the signature of a
11230 member function templates. Otherwise ARG is a
11231 TEMPLATE_DECL and is the real template to be
11233 if (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
11234 arg = TYPE_NAME (arg);
11236 r = lookup_template_class (arg,
11238 DECL_CONTEXT (arg),
11239 /*entering_scope=*/0,
11241 return cp_build_qualified_type_real
11242 (r, cp_type_quals (t), complain);
11245 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
11246 return convert_from_reference (unshare_expr (arg));
11250 /* This can happen during the attempted tsubst'ing in
11251 unify. This means that we don't yet have any information
11252 about the template parameter in question. */
11255 /* If we get here, we must have been looking at a parm for a
11256 more deeply nested template. Make a new version of this
11257 template parameter, but with a lower level. */
11260 case TEMPLATE_TYPE_PARM:
11261 case TEMPLATE_TEMPLATE_PARM:
11262 case BOUND_TEMPLATE_TEMPLATE_PARM:
11263 if (cp_type_quals (t))
11265 r = tsubst (TYPE_MAIN_VARIANT (t), args, complain, in_decl);
11266 r = cp_build_qualified_type_real
11267 (r, cp_type_quals (t),
11268 complain | (code == TEMPLATE_TYPE_PARM
11269 ? tf_ignore_bad_quals : 0));
11274 TEMPLATE_TYPE_PARM_INDEX (r)
11275 = reduce_template_parm_level (TEMPLATE_TYPE_PARM_INDEX (t),
11276 r, levels, args, complain);
11277 TYPE_STUB_DECL (r) = TYPE_NAME (r) = TEMPLATE_TYPE_DECL (r);
11278 TYPE_MAIN_VARIANT (r) = r;
11279 TYPE_POINTER_TO (r) = NULL_TREE;
11280 TYPE_REFERENCE_TO (r) = NULL_TREE;
11282 if (TREE_CODE (r) == TEMPLATE_TEMPLATE_PARM)
11283 /* We have reduced the level of the template
11284 template parameter, but not the levels of its
11285 template parameters, so canonical_type_parameter
11286 will not be able to find the canonical template
11287 template parameter for this level. Thus, we
11288 require structural equality checking to compare
11289 TEMPLATE_TEMPLATE_PARMs. */
11290 SET_TYPE_STRUCTURAL_EQUALITY (r);
11291 else if (TYPE_STRUCTURAL_EQUALITY_P (t))
11292 SET_TYPE_STRUCTURAL_EQUALITY (r);
11294 TYPE_CANONICAL (r) = canonical_type_parameter (r);
11296 if (code == BOUND_TEMPLATE_TEMPLATE_PARM)
11298 tree argvec = tsubst (TYPE_TI_ARGS (t), args,
11299 complain, in_decl);
11300 if (argvec == error_mark_node)
11301 return error_mark_node;
11303 TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (r)
11304 = build_template_info (TYPE_TI_TEMPLATE (t), argvec);
11309 case TEMPLATE_PARM_INDEX:
11310 r = reduce_template_parm_level (t, type, levels, args, complain);
11314 gcc_unreachable ();
11322 tree purpose, value, chain;
11324 if (t == void_list_node)
11327 purpose = TREE_PURPOSE (t);
11330 purpose = tsubst (purpose, args, complain, in_decl);
11331 if (purpose == error_mark_node)
11332 return error_mark_node;
11334 value = TREE_VALUE (t);
11337 value = tsubst (value, args, complain, in_decl);
11338 if (value == error_mark_node)
11339 return error_mark_node;
11341 chain = TREE_CHAIN (t);
11342 if (chain && chain != void_type_node)
11344 chain = tsubst (chain, args, complain, in_decl);
11345 if (chain == error_mark_node)
11346 return error_mark_node;
11348 if (purpose == TREE_PURPOSE (t)
11349 && value == TREE_VALUE (t)
11350 && chain == TREE_CHAIN (t))
11352 return hash_tree_cons (purpose, value, chain);
11356 /* We should never be tsubsting a binfo. */
11357 gcc_unreachable ();
11360 /* A vector of template arguments. */
11361 gcc_assert (!type);
11362 return tsubst_template_args (t, args, complain, in_decl);
11365 case REFERENCE_TYPE:
11367 if (type == TREE_TYPE (t) && TREE_CODE (type) != METHOD_TYPE)
11372 Type deduction may fail for any of the following
11375 -- Attempting to create a pointer to reference type.
11376 -- Attempting to create a reference to a reference type or
11377 a reference to void.
11379 Core issue 106 says that creating a reference to a reference
11380 during instantiation is no longer a cause for failure. We
11381 only enforce this check in strict C++98 mode. */
11382 if ((TREE_CODE (type) == REFERENCE_TYPE
11383 && (((cxx_dialect == cxx98) && flag_iso) || code != REFERENCE_TYPE))
11384 || (code == REFERENCE_TYPE && TREE_CODE (type) == VOID_TYPE))
11386 static location_t last_loc;
11388 /* We keep track of the last time we issued this error
11389 message to avoid spewing a ton of messages during a
11390 single bad template instantiation. */
11391 if (complain & tf_error
11392 && last_loc != input_location)
11394 if (TREE_CODE (type) == VOID_TYPE)
11395 error ("forming reference to void");
11396 else if (code == POINTER_TYPE)
11397 error ("forming pointer to reference type %qT", type);
11399 error ("forming reference to reference type %qT", type);
11400 last_loc = input_location;
11403 return error_mark_node;
11405 else if (code == POINTER_TYPE)
11407 r = build_pointer_type (type);
11408 if (TREE_CODE (type) == METHOD_TYPE)
11409 r = build_ptrmemfunc_type (r);
11411 else if (TREE_CODE (type) == REFERENCE_TYPE)
11412 /* In C++0x, during template argument substitution, when there is an
11413 attempt to create a reference to a reference type, reference
11414 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
11416 "If a template-argument for a template-parameter T names a type
11417 that is a reference to a type A, an attempt to create the type
11418 'lvalue reference to cv T' creates the type 'lvalue reference to
11419 A,' while an attempt to create the type type rvalue reference to
11420 cv T' creates the type T"
11422 r = cp_build_reference_type
11424 TYPE_REF_IS_RVALUE (t) && TYPE_REF_IS_RVALUE (type));
11426 r = cp_build_reference_type (type, TYPE_REF_IS_RVALUE (t));
11427 r = cp_build_qualified_type_real (r, cp_type_quals (t), complain);
11429 if (r != error_mark_node)
11430 /* Will this ever be needed for TYPE_..._TO values? */
11437 r = tsubst (TYPE_OFFSET_BASETYPE (t), args, complain, in_decl);
11438 if (r == error_mark_node || !MAYBE_CLASS_TYPE_P (r))
11442 Type deduction may fail for any of the following
11445 -- Attempting to create "pointer to member of T" when T
11446 is not a class type. */
11447 if (complain & tf_error)
11448 error ("creating pointer to member of non-class type %qT", r);
11449 return error_mark_node;
11451 if (TREE_CODE (type) == REFERENCE_TYPE)
11453 if (complain & tf_error)
11454 error ("creating pointer to member reference type %qT", type);
11455 return error_mark_node;
11457 if (TREE_CODE (type) == VOID_TYPE)
11459 if (complain & tf_error)
11460 error ("creating pointer to member of type void");
11461 return error_mark_node;
11463 gcc_assert (TREE_CODE (type) != METHOD_TYPE);
11464 if (TREE_CODE (type) == FUNCTION_TYPE)
11466 /* The type of the implicit object parameter gets its
11467 cv-qualifiers from the FUNCTION_TYPE. */
11469 tree method_type = build_memfn_type (type, r, type_memfn_quals (type));
11470 memptr = build_ptrmemfunc_type (build_pointer_type (method_type));
11471 return cp_build_qualified_type_real (memptr, cp_type_quals (t),
11475 return cp_build_qualified_type_real (build_ptrmem_type (r, type),
11479 case FUNCTION_TYPE:
11484 fntype = tsubst_function_type (t, args, complain, in_decl);
11485 if (fntype == error_mark_node)
11486 return error_mark_node;
11488 /* Substitute the exception specification. */
11489 specs = tsubst_exception_specification (t, args, complain,
11490 in_decl, /*defer_ok*/true);
11491 if (specs == error_mark_node)
11492 return error_mark_node;
11494 fntype = build_exception_variant (fntype, specs);
11499 tree domain = tsubst (TYPE_DOMAIN (t), args, complain, in_decl);
11500 if (domain == error_mark_node)
11501 return error_mark_node;
11503 /* As an optimization, we avoid regenerating the array type if
11504 it will obviously be the same as T. */
11505 if (type == TREE_TYPE (t) && domain == TYPE_DOMAIN (t))
11508 /* These checks should match the ones in grokdeclarator.
11512 The deduction may fail for any of the following reasons:
11514 -- Attempting to create an array with an element type that
11515 is void, a function type, or a reference type, or [DR337]
11516 an abstract class type. */
11517 if (TREE_CODE (type) == VOID_TYPE
11518 || TREE_CODE (type) == FUNCTION_TYPE
11519 || TREE_CODE (type) == REFERENCE_TYPE)
11521 if (complain & tf_error)
11522 error ("creating array of %qT", type);
11523 return error_mark_node;
11525 if (CLASS_TYPE_P (type) && CLASSTYPE_PURE_VIRTUALS (type))
11527 if (complain & tf_error)
11528 error ("creating array of %qT, which is an abstract class type",
11530 return error_mark_node;
11533 r = build_cplus_array_type (type, domain);
11535 if (TYPE_USER_ALIGN (t))
11537 TYPE_ALIGN (r) = TYPE_ALIGN (t);
11538 TYPE_USER_ALIGN (r) = 1;
11544 case TYPENAME_TYPE:
11546 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
11547 in_decl, /*entering_scope=*/1);
11548 tree f = tsubst_copy (TYPENAME_TYPE_FULLNAME (t), args,
11549 complain, in_decl);
11551 if (ctx == error_mark_node || f == error_mark_node)
11552 return error_mark_node;
11554 if (!MAYBE_CLASS_TYPE_P (ctx))
11556 if (complain & tf_error)
11557 error ("%qT is not a class, struct, or union type", ctx);
11558 return error_mark_node;
11560 else if (!uses_template_parms (ctx) && !TYPE_BEING_DEFINED (ctx))
11562 /* Normally, make_typename_type does not require that the CTX
11563 have complete type in order to allow things like:
11565 template <class T> struct S { typename S<T>::X Y; };
11567 But, such constructs have already been resolved by this
11568 point, so here CTX really should have complete type, unless
11569 it's a partial instantiation. */
11570 ctx = complete_type (ctx);
11571 if (!COMPLETE_TYPE_P (ctx))
11573 if (complain & tf_error)
11574 cxx_incomplete_type_error (NULL_TREE, ctx);
11575 return error_mark_node;
11579 f = make_typename_type (ctx, f, typename_type,
11580 (complain & tf_error) | tf_keep_type_decl);
11581 if (f == error_mark_node)
11583 if (TREE_CODE (f) == TYPE_DECL)
11585 complain |= tf_ignore_bad_quals;
11589 if (TREE_CODE (f) != TYPENAME_TYPE)
11591 if (TYPENAME_IS_ENUM_P (t) && TREE_CODE (f) != ENUMERAL_TYPE)
11593 if (complain & tf_error)
11594 error ("%qT resolves to %qT, which is not an enumeration type",
11597 return error_mark_node;
11599 else if (TYPENAME_IS_CLASS_P (t) && !CLASS_TYPE_P (f))
11601 if (complain & tf_error)
11602 error ("%qT resolves to %qT, which is is not a class type",
11605 return error_mark_node;
11609 return cp_build_qualified_type_real
11610 (f, cp_type_quals (f) | cp_type_quals (t), complain);
11613 case UNBOUND_CLASS_TEMPLATE:
11615 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
11616 in_decl, /*entering_scope=*/1);
11617 tree name = TYPE_IDENTIFIER (t);
11618 tree parm_list = DECL_TEMPLATE_PARMS (TYPE_NAME (t));
11620 if (ctx == error_mark_node || name == error_mark_node)
11621 return error_mark_node;
11624 parm_list = tsubst_template_parms (parm_list, args, complain);
11625 return make_unbound_class_template (ctx, name, parm_list, complain);
11632 ++cp_unevaluated_operand;
11633 ++c_inhibit_evaluation_warnings;
11635 type = tsubst_expr (TYPEOF_TYPE_EXPR (t), args,
11637 /*integral_constant_expression_p=*/false);
11639 --cp_unevaluated_operand;
11640 --c_inhibit_evaluation_warnings;
11642 type = finish_typeof (type);
11643 return cp_build_qualified_type_real (type,
11645 | cp_type_quals (type),
11649 case DECLTYPE_TYPE:
11653 ++cp_unevaluated_operand;
11654 ++c_inhibit_evaluation_warnings;
11656 type = tsubst_expr (DECLTYPE_TYPE_EXPR (t), args,
11658 /*integral_constant_expression_p=*/false);
11660 --cp_unevaluated_operand;
11661 --c_inhibit_evaluation_warnings;
11663 if (DECLTYPE_FOR_LAMBDA_CAPTURE (t))
11664 type = lambda_capture_field_type (type);
11665 else if (DECLTYPE_FOR_LAMBDA_PROXY (t))
11666 type = lambda_proxy_type (type);
11668 type = finish_decltype_type
11669 (type, DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t), complain);
11670 return cp_build_qualified_type_real (type,
11672 | cp_type_quals (type),
11676 case UNDERLYING_TYPE:
11678 tree type = tsubst (UNDERLYING_TYPE_TYPE (t), args,
11679 complain, in_decl);
11680 return finish_underlying_type (type);
11683 case TYPE_ARGUMENT_PACK:
11684 case NONTYPE_ARGUMENT_PACK:
11686 tree r = TYPE_P (t) ? cxx_make_type (code) : make_node (code);
11688 tsubst_template_args (ARGUMENT_PACK_ARGS (t),
11692 SET_ARGUMENT_PACK_ARGS (r, packed_out);
11694 /* For template nontype argument packs, also substitute into
11696 if (code == NONTYPE_ARGUMENT_PACK)
11697 TREE_TYPE (r) = tsubst (TREE_TYPE (t), args, complain, in_decl);
11715 /* We should use one of the expression tsubsts for these codes. */
11716 gcc_unreachable ();
11719 sorry ("use of %qs in template", tree_code_name [(int) code]);
11720 return error_mark_node;
11724 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
11725 type of the expression on the left-hand side of the "." or "->"
11729 tsubst_baselink (tree baselink, tree object_type,
11730 tree args, tsubst_flags_t complain, tree in_decl)
11733 tree qualifying_scope;
11736 tree template_args = 0;
11737 bool template_id_p = false;
11739 /* A baselink indicates a function from a base class. Both the
11740 BASELINK_ACCESS_BINFO and the base class referenced may
11741 indicate bases of the template class, rather than the
11742 instantiated class. In addition, lookups that were not
11743 ambiguous before may be ambiguous now. Therefore, we perform
11744 the lookup again. */
11745 qualifying_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (baselink));
11746 qualifying_scope = tsubst (qualifying_scope, args,
11747 complain, in_decl);
11748 fns = BASELINK_FUNCTIONS (baselink);
11749 optype = tsubst (BASELINK_OPTYPE (baselink), args, complain, in_decl);
11750 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
11752 template_id_p = true;
11753 template_args = TREE_OPERAND (fns, 1);
11754 fns = TREE_OPERAND (fns, 0);
11756 template_args = tsubst_template_args (template_args, args,
11757 complain, in_decl);
11759 name = DECL_NAME (get_first_fn (fns));
11760 if (IDENTIFIER_TYPENAME_P (name))
11761 name = mangle_conv_op_name_for_type (optype);
11762 baselink = lookup_fnfields (qualifying_scope, name, /*protect=*/1);
11764 return error_mark_node;
11766 /* If lookup found a single function, mark it as used at this
11767 point. (If it lookup found multiple functions the one selected
11768 later by overload resolution will be marked as used at that
11770 if (BASELINK_P (baselink))
11771 fns = BASELINK_FUNCTIONS (baselink);
11772 if (!template_id_p && !really_overloaded_fn (fns))
11773 mark_used (OVL_CURRENT (fns));
11775 /* Add back the template arguments, if present. */
11776 if (BASELINK_P (baselink) && template_id_p)
11777 BASELINK_FUNCTIONS (baselink)
11778 = build_nt (TEMPLATE_ID_EXPR,
11779 BASELINK_FUNCTIONS (baselink),
11781 /* Update the conversion operator type. */
11782 BASELINK_OPTYPE (baselink) = optype;
11785 object_type = current_class_type;
11786 return adjust_result_of_qualified_name_lookup (baselink,
11791 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
11792 true if the qualified-id will be a postfix-expression in-and-of
11793 itself; false if more of the postfix-expression follows the
11794 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
11798 tsubst_qualified_id (tree qualified_id, tree args,
11799 tsubst_flags_t complain, tree in_decl,
11800 bool done, bool address_p)
11806 tree template_args;
11808 gcc_assert (TREE_CODE (qualified_id) == SCOPE_REF);
11810 /* Figure out what name to look up. */
11811 name = TREE_OPERAND (qualified_id, 1);
11812 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
11814 is_template = true;
11815 template_args = TREE_OPERAND (name, 1);
11817 template_args = tsubst_template_args (template_args, args,
11818 complain, in_decl);
11819 name = TREE_OPERAND (name, 0);
11823 is_template = false;
11824 template_args = NULL_TREE;
11827 /* Substitute into the qualifying scope. When there are no ARGS, we
11828 are just trying to simplify a non-dependent expression. In that
11829 case the qualifying scope may be dependent, and, in any case,
11830 substituting will not help. */
11831 scope = TREE_OPERAND (qualified_id, 0);
11834 scope = tsubst (scope, args, complain, in_decl);
11835 expr = tsubst_copy (name, args, complain, in_decl);
11840 if (dependent_scope_p (scope))
11843 expr = build_min_nt (TEMPLATE_ID_EXPR, expr, template_args);
11844 return build_qualified_name (NULL_TREE, scope, expr,
11845 QUALIFIED_NAME_IS_TEMPLATE (qualified_id));
11848 if (!BASELINK_P (name) && !DECL_P (expr))
11850 if (TREE_CODE (expr) == BIT_NOT_EXPR)
11852 /* A BIT_NOT_EXPR is used to represent a destructor. */
11853 if (!check_dtor_name (scope, TREE_OPERAND (expr, 0)))
11855 error ("qualifying type %qT does not match destructor name ~%qT",
11856 scope, TREE_OPERAND (expr, 0));
11857 expr = error_mark_node;
11860 expr = lookup_qualified_name (scope, complete_dtor_identifier,
11861 /*is_type_p=*/0, false);
11864 expr = lookup_qualified_name (scope, expr, /*is_type_p=*/0, false);
11865 if (TREE_CODE (TREE_CODE (expr) == TEMPLATE_DECL
11866 ? DECL_TEMPLATE_RESULT (expr) : expr) == TYPE_DECL)
11868 if (complain & tf_error)
11870 error ("dependent-name %qE is parsed as a non-type, but "
11871 "instantiation yields a type", qualified_id);
11872 inform (input_location, "say %<typename %E%> if a type is meant", qualified_id);
11874 return error_mark_node;
11880 check_accessibility_of_qualified_id (expr, /*object_type=*/NULL_TREE,
11882 /* Remember that there was a reference to this entity. */
11886 if (expr == error_mark_node || TREE_CODE (expr) == TREE_LIST)
11888 if (complain & tf_error)
11889 qualified_name_lookup_error (scope,
11890 TREE_OPERAND (qualified_id, 1),
11891 expr, input_location);
11892 return error_mark_node;
11896 expr = lookup_template_function (expr, template_args);
11898 if (expr == error_mark_node && complain & tf_error)
11899 qualified_name_lookup_error (scope, TREE_OPERAND (qualified_id, 1),
11900 expr, input_location);
11901 else if (TYPE_P (scope))
11903 expr = (adjust_result_of_qualified_name_lookup
11904 (expr, scope, current_class_type));
11905 expr = (finish_qualified_id_expr
11906 (scope, expr, done, address_p && PTRMEM_OK_P (qualified_id),
11907 QUALIFIED_NAME_IS_TEMPLATE (qualified_id),
11908 /*template_arg_p=*/false));
11911 /* Expressions do not generally have reference type. */
11912 if (TREE_CODE (expr) != SCOPE_REF
11913 /* However, if we're about to form a pointer-to-member, we just
11914 want the referenced member referenced. */
11915 && TREE_CODE (expr) != OFFSET_REF)
11916 expr = convert_from_reference (expr);
11921 /* Like tsubst, but deals with expressions. This function just replaces
11922 template parms; to finish processing the resultant expression, use
11923 tsubst_copy_and_build or tsubst_expr. */
11926 tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl)
11928 enum tree_code code;
11931 if (t == NULL_TREE || t == error_mark_node || args == NULL_TREE)
11934 code = TREE_CODE (t);
11939 r = retrieve_local_specialization (t);
11945 /* We get here for a use of 'this' in an NSDMI. */
11946 if (DECL_NAME (t) == this_identifier
11947 && at_function_scope_p ()
11948 && DECL_CONSTRUCTOR_P (current_function_decl))
11949 return current_class_ptr;
11951 /* This can happen for a parameter name used later in a function
11952 declaration (such as in a late-specified return type). Just
11953 make a dummy decl, since it's only used for its type. */
11954 gcc_assert (cp_unevaluated_operand != 0);
11955 /* We copy T because want to tsubst the PARM_DECL only,
11956 not the following PARM_DECLs that are chained to T. */
11958 r = tsubst_decl (c, args, complain);
11959 /* Give it the template pattern as its context; its true context
11960 hasn't been instantiated yet and this is good enough for
11962 DECL_CONTEXT (r) = DECL_CONTEXT (t);
11965 if (TREE_CODE (r) == ARGUMENT_PACK_SELECT)
11966 r = ARGUMENT_PACK_SELECT_ARG (r);
11975 if (DECL_TEMPLATE_PARM_P (t))
11976 return tsubst_copy (DECL_INITIAL (t), args, complain, in_decl);
11977 /* There is no need to substitute into namespace-scope
11979 if (DECL_NAMESPACE_SCOPE_P (t))
11981 /* If ARGS is NULL, then T is known to be non-dependent. */
11982 if (args == NULL_TREE)
11983 return integral_constant_value (t);
11985 /* Unfortunately, we cannot just call lookup_name here.
11988 template <int I> int f() {
11990 struct S { void g() { E e = a; } };
11993 When we instantiate f<7>::S::g(), say, lookup_name is not
11994 clever enough to find f<7>::a. */
11996 = tsubst_aggr_type (TREE_TYPE (t), args, complain, in_decl,
11997 /*entering_scope=*/0);
11999 for (v = TYPE_VALUES (enum_type);
12001 v = TREE_CHAIN (v))
12002 if (TREE_PURPOSE (v) == DECL_NAME (t))
12003 return TREE_VALUE (v);
12005 /* We didn't find the name. That should never happen; if
12006 name-lookup found it during preliminary parsing, we
12007 should find it again here during instantiation. */
12008 gcc_unreachable ();
12013 if (DECL_CONTEXT (t))
12017 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args, complain, in_decl,
12018 /*entering_scope=*/1);
12019 if (ctx != DECL_CONTEXT (t))
12021 tree r = lookup_field (ctx, DECL_NAME (t), 0, false);
12024 if (complain & tf_error)
12025 error ("using invalid field %qD", t);
12026 return error_mark_node;
12035 case FUNCTION_DECL:
12036 if ((DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t))
12037 || local_variable_p (t))
12038 t = tsubst (t, args, complain, in_decl);
12042 case NAMESPACE_DECL:
12046 /* An OVERLOAD will always be a non-dependent overload set; an
12047 overload set from function scope will just be represented with an
12048 IDENTIFIER_NODE, and from class scope with a BASELINK. */
12049 gcc_assert (!uses_template_parms (t));
12053 return tsubst_baselink (t, current_class_type, args, complain, in_decl);
12055 case TEMPLATE_DECL:
12056 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
12057 return tsubst (TREE_TYPE (DECL_TEMPLATE_RESULT (t)),
12058 args, complain, in_decl);
12059 else if (DECL_FUNCTION_TEMPLATE_P (t) && DECL_MEMBER_TEMPLATE_P (t))
12060 return tsubst (t, args, complain, in_decl);
12061 else if (DECL_CLASS_SCOPE_P (t)
12062 && uses_template_parms (DECL_CONTEXT (t)))
12064 /* Template template argument like the following example need
12067 template <template <class> class TT> struct C {};
12068 template <class T> struct D {
12069 template <class U> struct E {};
12074 We are processing the template argument `E' in #1 for
12075 the template instantiation #2. Originally, `E' is a
12076 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
12077 have to substitute this with one having context `D<int>'. */
12079 tree context = tsubst (DECL_CONTEXT (t), args, complain, in_decl);
12080 return lookup_field (context, DECL_NAME(t), 0, false);
12083 /* Ordinary template template argument. */
12087 case REINTERPRET_CAST_EXPR:
12088 case CONST_CAST_EXPR:
12089 case STATIC_CAST_EXPR:
12090 case DYNAMIC_CAST_EXPR:
12091 case IMPLICIT_CONV_EXPR:
12095 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
12096 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
12099 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
12105 ++cp_unevaluated_operand;
12106 ++c_inhibit_evaluation_warnings;
12107 /* We only want to compute the number of arguments. */
12108 expanded = tsubst_pack_expansion (TREE_OPERAND (t, 0), args,
12109 complain, in_decl);
12110 --cp_unevaluated_operand;
12111 --c_inhibit_evaluation_warnings;
12113 if (TREE_CODE (expanded) == TREE_VEC)
12114 len = TREE_VEC_LENGTH (expanded);
12116 if (expanded == error_mark_node)
12117 return error_mark_node;
12118 else if (PACK_EXPANSION_P (expanded)
12119 || (TREE_CODE (expanded) == TREE_VEC
12121 && PACK_EXPANSION_P (TREE_VEC_ELT (expanded, len-1))))
12123 if (TREE_CODE (expanded) == TREE_VEC)
12124 expanded = TREE_VEC_ELT (expanded, len - 1);
12126 if (TYPE_P (expanded))
12127 return cxx_sizeof_or_alignof_type (expanded, SIZEOF_EXPR,
12128 complain & tf_error);
12130 return cxx_sizeof_or_alignof_expr (expanded, SIZEOF_EXPR,
12131 complain & tf_error);
12134 return build_int_cst (size_type_node, len);
12140 case TRUTH_NOT_EXPR:
12143 case UNARY_PLUS_EXPR: /* Unary + */
12145 case AT_ENCODE_EXPR:
12149 case REALPART_EXPR:
12150 case IMAGPART_EXPR:
12152 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
12153 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
12155 case COMPONENT_REF:
12160 object = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
12161 name = TREE_OPERAND (t, 1);
12162 if (TREE_CODE (name) == BIT_NOT_EXPR)
12164 name = tsubst_copy (TREE_OPERAND (name, 0), args,
12165 complain, in_decl);
12166 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
12168 else if (TREE_CODE (name) == SCOPE_REF
12169 && TREE_CODE (TREE_OPERAND (name, 1)) == BIT_NOT_EXPR)
12171 tree base = tsubst_copy (TREE_OPERAND (name, 0), args,
12172 complain, in_decl);
12173 name = TREE_OPERAND (name, 1);
12174 name = tsubst_copy (TREE_OPERAND (name, 0), args,
12175 complain, in_decl);
12176 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
12177 name = build_qualified_name (/*type=*/NULL_TREE,
12179 /*template_p=*/false);
12181 else if (BASELINK_P (name))
12182 name = tsubst_baselink (name,
12183 non_reference (TREE_TYPE (object)),
12187 name = tsubst_copy (name, args, complain, in_decl);
12188 return build_nt (COMPONENT_REF, object, name, NULL_TREE);
12194 case TRUNC_DIV_EXPR:
12195 case CEIL_DIV_EXPR:
12196 case FLOOR_DIV_EXPR:
12197 case ROUND_DIV_EXPR:
12198 case EXACT_DIV_EXPR:
12202 case TRUNC_MOD_EXPR:
12203 case FLOOR_MOD_EXPR:
12204 case TRUTH_ANDIF_EXPR:
12205 case TRUTH_ORIF_EXPR:
12206 case TRUTH_AND_EXPR:
12207 case TRUTH_OR_EXPR:
12220 case COMPOUND_EXPR:
12223 case PREDECREMENT_EXPR:
12224 case PREINCREMENT_EXPR:
12225 case POSTDECREMENT_EXPR:
12226 case POSTINCREMENT_EXPR:
12228 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12229 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
12232 return build_qualified_name (/*type=*/NULL_TREE,
12233 tsubst_copy (TREE_OPERAND (t, 0),
12234 args, complain, in_decl),
12235 tsubst_copy (TREE_OPERAND (t, 1),
12236 args, complain, in_decl),
12237 QUALIFIED_NAME_IS_TEMPLATE (t));
12242 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12243 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
12244 NULL_TREE, NULL_TREE);
12248 int n = VL_EXP_OPERAND_LENGTH (t);
12249 tree result = build_vl_exp (CALL_EXPR, n);
12251 for (i = 0; i < n; i++)
12252 TREE_OPERAND (t, i) = tsubst_copy (TREE_OPERAND (t, i), args,
12253 complain, in_decl);
12259 case PSEUDO_DTOR_EXPR:
12262 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12263 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
12264 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
12265 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
12272 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12273 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
12274 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
12275 NEW_EXPR_USE_GLOBAL (r) = NEW_EXPR_USE_GLOBAL (t);
12282 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12283 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
12284 DELETE_EXPR_USE_GLOBAL (r) = DELETE_EXPR_USE_GLOBAL (t);
12285 DELETE_EXPR_USE_VEC (r) = DELETE_EXPR_USE_VEC (t);
12289 case TEMPLATE_ID_EXPR:
12291 /* Substituted template arguments */
12292 tree fn = TREE_OPERAND (t, 0);
12293 tree targs = TREE_OPERAND (t, 1);
12295 fn = tsubst_copy (fn, args, complain, in_decl);
12297 targs = tsubst_template_args (targs, args, complain, in_decl);
12299 return lookup_template_function (fn, targs);
12304 tree purpose, value, chain;
12306 if (t == void_list_node)
12309 purpose = TREE_PURPOSE (t);
12311 purpose = tsubst_copy (purpose, args, complain, in_decl);
12312 value = TREE_VALUE (t);
12314 value = tsubst_copy (value, args, complain, in_decl);
12315 chain = TREE_CHAIN (t);
12316 if (chain && chain != void_type_node)
12317 chain = tsubst_copy (chain, args, complain, in_decl);
12318 if (purpose == TREE_PURPOSE (t)
12319 && value == TREE_VALUE (t)
12320 && chain == TREE_CHAIN (t))
12322 return tree_cons (purpose, value, chain);
12327 case ENUMERAL_TYPE:
12329 case TEMPLATE_TYPE_PARM:
12330 case TEMPLATE_TEMPLATE_PARM:
12331 case BOUND_TEMPLATE_TEMPLATE_PARM:
12332 case TEMPLATE_PARM_INDEX:
12334 case REFERENCE_TYPE:
12336 case FUNCTION_TYPE:
12339 case TYPENAME_TYPE:
12340 case UNBOUND_CLASS_TEMPLATE:
12342 case DECLTYPE_TYPE:
12344 return tsubst (t, args, complain, in_decl);
12346 case IDENTIFIER_NODE:
12347 if (IDENTIFIER_TYPENAME_P (t))
12349 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12350 return mangle_conv_op_name_for_type (new_type);
12356 /* This is handled by tsubst_copy_and_build. */
12357 gcc_unreachable ();
12360 return build_x_va_arg (tsubst_copy (TREE_OPERAND (t, 0), args, complain,
12362 tsubst (TREE_TYPE (t), args, complain, in_decl));
12364 case CLEANUP_POINT_EXPR:
12365 /* We shouldn't have built any of these during initial template
12366 generation. Instead, they should be built during instantiation
12367 in response to the saved STMT_IS_FULL_EXPR_P setting. */
12368 gcc_unreachable ();
12372 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
12373 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12374 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
12375 PTRMEM_OK_P (r) = PTRMEM_OK_P (t);
12376 mark_used (TREE_OPERAND (r, 1));
12379 case EXPR_PACK_EXPANSION:
12380 error ("invalid use of pack expansion expression");
12381 return error_mark_node;
12383 case NONTYPE_ARGUMENT_PACK:
12384 error ("use %<...%> to expand argument pack");
12385 return error_mark_node;
12392 /* Instantiate any typedefs in the type. */
12393 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12394 r = fold_convert (type, t);
12395 gcc_assert (TREE_CODE (r) == code);
12400 /* These can sometimes show up in a partial instantiation, but never
12401 involve template parms. */
12402 gcc_assert (!uses_template_parms (t));
12406 /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */
12407 gcc_checking_assert (false);
12412 /* Like tsubst_copy, but specifically for OpenMP clauses. */
12415 tsubst_omp_clauses (tree clauses, tree args, tsubst_flags_t complain,
12418 tree new_clauses = NULL, nc, oc;
12420 for (oc = clauses; oc ; oc = OMP_CLAUSE_CHAIN (oc))
12422 nc = copy_node (oc);
12423 OMP_CLAUSE_CHAIN (nc) = new_clauses;
12426 switch (OMP_CLAUSE_CODE (nc))
12428 case OMP_CLAUSE_LASTPRIVATE:
12429 if (OMP_CLAUSE_LASTPRIVATE_STMT (oc))
12431 OMP_CLAUSE_LASTPRIVATE_STMT (nc) = push_stmt_list ();
12432 tsubst_expr (OMP_CLAUSE_LASTPRIVATE_STMT (oc), args, complain,
12433 in_decl, /*integral_constant_expression_p=*/false);
12434 OMP_CLAUSE_LASTPRIVATE_STMT (nc)
12435 = pop_stmt_list (OMP_CLAUSE_LASTPRIVATE_STMT (nc));
12438 case OMP_CLAUSE_PRIVATE:
12439 case OMP_CLAUSE_SHARED:
12440 case OMP_CLAUSE_FIRSTPRIVATE:
12441 case OMP_CLAUSE_REDUCTION:
12442 case OMP_CLAUSE_COPYIN:
12443 case OMP_CLAUSE_COPYPRIVATE:
12444 case OMP_CLAUSE_IF:
12445 case OMP_CLAUSE_NUM_THREADS:
12446 case OMP_CLAUSE_SCHEDULE:
12447 case OMP_CLAUSE_COLLAPSE:
12448 case OMP_CLAUSE_FINAL:
12449 OMP_CLAUSE_OPERAND (nc, 0)
12450 = tsubst_expr (OMP_CLAUSE_OPERAND (oc, 0), args, complain,
12451 in_decl, /*integral_constant_expression_p=*/false);
12453 case OMP_CLAUSE_NOWAIT:
12454 case OMP_CLAUSE_ORDERED:
12455 case OMP_CLAUSE_DEFAULT:
12456 case OMP_CLAUSE_UNTIED:
12457 case OMP_CLAUSE_MERGEABLE:
12460 gcc_unreachable ();
12464 return finish_omp_clauses (nreverse (new_clauses));
12467 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
12470 tsubst_copy_asm_operands (tree t, tree args, tsubst_flags_t complain,
12473 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
12475 tree purpose, value, chain;
12480 if (TREE_CODE (t) != TREE_LIST)
12481 return tsubst_copy_and_build (t, args, complain, in_decl,
12482 /*function_p=*/false,
12483 /*integral_constant_expression_p=*/false);
12485 if (t == void_list_node)
12488 purpose = TREE_PURPOSE (t);
12490 purpose = RECUR (purpose);
12491 value = TREE_VALUE (t);
12492 if (value && TREE_CODE (value) != LABEL_DECL)
12493 value = RECUR (value);
12494 chain = TREE_CHAIN (t);
12495 if (chain && chain != void_type_node)
12496 chain = RECUR (chain);
12497 return tree_cons (purpose, value, chain);
12501 /* Substitute one OMP_FOR iterator. */
12504 tsubst_omp_for_iterator (tree t, int i, tree declv, tree initv,
12505 tree condv, tree incrv, tree *clauses,
12506 tree args, tsubst_flags_t complain, tree in_decl,
12507 bool integral_constant_expression_p)
12509 #define RECUR(NODE) \
12510 tsubst_expr ((NODE), args, complain, in_decl, \
12511 integral_constant_expression_p)
12512 tree decl, init, cond, incr, auto_node;
12514 init = TREE_VEC_ELT (OMP_FOR_INIT (t), i);
12515 gcc_assert (TREE_CODE (init) == MODIFY_EXPR);
12516 decl = RECUR (TREE_OPERAND (init, 0));
12517 init = TREE_OPERAND (init, 1);
12518 auto_node = type_uses_auto (TREE_TYPE (decl));
12519 if (auto_node && init)
12521 tree init_expr = init;
12522 if (TREE_CODE (init_expr) == DECL_EXPR)
12523 init_expr = DECL_INITIAL (DECL_EXPR_DECL (init_expr));
12524 init_expr = RECUR (init_expr);
12526 = do_auto_deduction (TREE_TYPE (decl), init_expr, auto_node);
12528 gcc_assert (!type_dependent_expression_p (decl));
12530 if (!CLASS_TYPE_P (TREE_TYPE (decl)))
12532 cond = RECUR (TREE_VEC_ELT (OMP_FOR_COND (t), i));
12533 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
12534 if (TREE_CODE (incr) == MODIFY_EXPR)
12535 incr = build_x_modify_expr (RECUR (TREE_OPERAND (incr, 0)), NOP_EXPR,
12536 RECUR (TREE_OPERAND (incr, 1)),
12539 incr = RECUR (incr);
12540 TREE_VEC_ELT (declv, i) = decl;
12541 TREE_VEC_ELT (initv, i) = init;
12542 TREE_VEC_ELT (condv, i) = cond;
12543 TREE_VEC_ELT (incrv, i) = incr;
12547 if (init && TREE_CODE (init) != DECL_EXPR)
12550 for (c = *clauses; c ; c = OMP_CLAUSE_CHAIN (c))
12552 if ((OMP_CLAUSE_CODE (c) == OMP_CLAUSE_PRIVATE
12553 || OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LASTPRIVATE)
12554 && OMP_CLAUSE_DECL (c) == decl)
12556 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_FIRSTPRIVATE
12557 && OMP_CLAUSE_DECL (c) == decl)
12558 error ("iteration variable %qD should not be firstprivate", decl);
12559 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_REDUCTION
12560 && OMP_CLAUSE_DECL (c) == decl)
12561 error ("iteration variable %qD should not be reduction", decl);
12565 c = build_omp_clause (input_location, OMP_CLAUSE_PRIVATE);
12566 OMP_CLAUSE_DECL (c) = decl;
12567 c = finish_omp_clauses (c);
12570 OMP_CLAUSE_CHAIN (c) = *clauses;
12575 cond = TREE_VEC_ELT (OMP_FOR_COND (t), i);
12576 if (COMPARISON_CLASS_P (cond))
12577 cond = build2 (TREE_CODE (cond), boolean_type_node,
12578 RECUR (TREE_OPERAND (cond, 0)),
12579 RECUR (TREE_OPERAND (cond, 1)));
12581 cond = RECUR (cond);
12582 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
12583 switch (TREE_CODE (incr))
12585 case PREINCREMENT_EXPR:
12586 case PREDECREMENT_EXPR:
12587 case POSTINCREMENT_EXPR:
12588 case POSTDECREMENT_EXPR:
12589 incr = build2 (TREE_CODE (incr), TREE_TYPE (decl),
12590 RECUR (TREE_OPERAND (incr, 0)), NULL_TREE);
12593 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
12594 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
12596 tree rhs = TREE_OPERAND (incr, 1);
12597 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
12598 RECUR (TREE_OPERAND (incr, 0)),
12599 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
12600 RECUR (TREE_OPERAND (rhs, 0)),
12601 RECUR (TREE_OPERAND (rhs, 1))));
12604 incr = RECUR (incr);
12607 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
12608 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
12610 tree lhs = RECUR (TREE_OPERAND (incr, 0));
12611 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl), lhs,
12612 build2 (TREE_CODE (TREE_OPERAND (incr, 1)),
12613 TREE_TYPE (decl), lhs,
12614 RECUR (TREE_OPERAND (incr, 2))));
12616 else if (TREE_CODE (TREE_OPERAND (incr, 1)) == NOP_EXPR
12617 && (TREE_CODE (TREE_OPERAND (incr, 2)) == PLUS_EXPR
12618 || (TREE_CODE (TREE_OPERAND (incr, 2)) == MINUS_EXPR)))
12620 tree rhs = TREE_OPERAND (incr, 2);
12621 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
12622 RECUR (TREE_OPERAND (incr, 0)),
12623 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
12624 RECUR (TREE_OPERAND (rhs, 0)),
12625 RECUR (TREE_OPERAND (rhs, 1))));
12628 incr = RECUR (incr);
12631 incr = RECUR (incr);
12635 TREE_VEC_ELT (declv, i) = decl;
12636 TREE_VEC_ELT (initv, i) = init;
12637 TREE_VEC_ELT (condv, i) = cond;
12638 TREE_VEC_ELT (incrv, i) = incr;
12642 /* Like tsubst_copy for expressions, etc. but also does semantic
12646 tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl,
12647 bool integral_constant_expression_p)
12649 #define RECUR(NODE) \
12650 tsubst_expr ((NODE), args, complain, in_decl, \
12651 integral_constant_expression_p)
12655 if (t == NULL_TREE || t == error_mark_node)
12658 if (EXPR_HAS_LOCATION (t))
12659 input_location = EXPR_LOCATION (t);
12660 if (STATEMENT_CODE_P (TREE_CODE (t)))
12661 current_stmt_tree ()->stmts_are_full_exprs_p = STMT_IS_FULL_EXPR_P (t);
12663 switch (TREE_CODE (t))
12665 case STATEMENT_LIST:
12667 tree_stmt_iterator i;
12668 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
12669 RECUR (tsi_stmt (i));
12673 case CTOR_INITIALIZER:
12674 finish_mem_initializers (tsubst_initializer_list
12675 (TREE_OPERAND (t, 0), args));
12679 finish_return_stmt (RECUR (TREE_OPERAND (t, 0)));
12683 tmp = RECUR (EXPR_STMT_EXPR (t));
12684 if (EXPR_STMT_STMT_EXPR_RESULT (t))
12685 finish_stmt_expr_expr (tmp, cur_stmt_expr);
12687 finish_expr_stmt (tmp);
12691 do_using_directive (USING_STMT_NAMESPACE (t));
12696 tree decl, pattern_decl;
12699 pattern_decl = decl = DECL_EXPR_DECL (t);
12700 if (TREE_CODE (decl) == LABEL_DECL)
12701 finish_label_decl (DECL_NAME (decl));
12702 else if (TREE_CODE (decl) == USING_DECL)
12704 tree scope = USING_DECL_SCOPE (decl);
12705 tree name = DECL_NAME (decl);
12708 scope = tsubst (scope, args, complain, in_decl);
12709 decl = lookup_qualified_name (scope, name,
12710 /*is_type_p=*/false,
12711 /*complain=*/false);
12712 if (decl == error_mark_node || TREE_CODE (decl) == TREE_LIST)
12713 qualified_name_lookup_error (scope, name, decl, input_location);
12715 do_local_using_decl (decl, scope, name);
12719 init = DECL_INITIAL (decl);
12720 decl = tsubst (decl, args, complain, in_decl);
12721 if (decl != error_mark_node)
12723 /* By marking the declaration as instantiated, we avoid
12724 trying to instantiate it. Since instantiate_decl can't
12725 handle local variables, and since we've already done
12726 all that needs to be done, that's the right thing to
12728 if (TREE_CODE (decl) == VAR_DECL)
12729 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
12730 if (TREE_CODE (decl) == VAR_DECL
12731 && ANON_AGGR_TYPE_P (TREE_TYPE (decl)))
12732 /* Anonymous aggregates are a special case. */
12733 finish_anon_union (decl);
12736 int const_init = false;
12737 maybe_push_decl (decl);
12738 if (TREE_CODE (decl) == VAR_DECL
12739 && DECL_PRETTY_FUNCTION_P (decl))
12741 /* For __PRETTY_FUNCTION__ we have to adjust the
12743 const char *const name
12744 = cxx_printable_name (current_function_decl, 2);
12745 init = cp_fname_init (name, &TREE_TYPE (decl));
12749 tree t = RECUR (init);
12753 /* If we had an initializer but it
12754 instantiated to nothing,
12755 value-initialize the object. This will
12756 only occur when the initializer was a
12757 pack expansion where the parameter packs
12758 used in that expansion were of length
12760 init = build_value_init (TREE_TYPE (decl),
12762 if (TREE_CODE (init) == AGGR_INIT_EXPR)
12763 init = get_target_expr_sfinae (init, complain);
12769 if (TREE_CODE (decl) == VAR_DECL)
12770 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
12772 cp_finish_decl (decl, init, const_init, NULL_TREE, 0);
12777 /* A DECL_EXPR can also be used as an expression, in the condition
12778 clause of an if/for/while construct. */
12783 stmt = begin_for_stmt (NULL_TREE, NULL_TREE);
12784 RECUR (FOR_INIT_STMT (t));
12785 finish_for_init_stmt (stmt);
12786 tmp = RECUR (FOR_COND (t));
12787 finish_for_cond (tmp, stmt);
12788 tmp = RECUR (FOR_EXPR (t));
12789 finish_for_expr (tmp, stmt);
12790 RECUR (FOR_BODY (t));
12791 finish_for_stmt (stmt);
12794 case RANGE_FOR_STMT:
12797 stmt = begin_for_stmt (NULL_TREE, NULL_TREE);
12798 decl = RANGE_FOR_DECL (t);
12799 decl = tsubst (decl, args, complain, in_decl);
12800 maybe_push_decl (decl);
12801 expr = RECUR (RANGE_FOR_EXPR (t));
12802 stmt = cp_convert_range_for (stmt, decl, expr);
12803 RECUR (RANGE_FOR_BODY (t));
12804 finish_for_stmt (stmt);
12809 stmt = begin_while_stmt ();
12810 tmp = RECUR (WHILE_COND (t));
12811 finish_while_stmt_cond (tmp, stmt);
12812 RECUR (WHILE_BODY (t));
12813 finish_while_stmt (stmt);
12817 stmt = begin_do_stmt ();
12818 RECUR (DO_BODY (t));
12819 finish_do_body (stmt);
12820 tmp = RECUR (DO_COND (t));
12821 finish_do_stmt (tmp, stmt);
12825 stmt = begin_if_stmt ();
12826 tmp = RECUR (IF_COND (t));
12827 finish_if_stmt_cond (tmp, stmt);
12828 RECUR (THEN_CLAUSE (t));
12829 finish_then_clause (stmt);
12831 if (ELSE_CLAUSE (t))
12833 begin_else_clause (stmt);
12834 RECUR (ELSE_CLAUSE (t));
12835 finish_else_clause (stmt);
12838 finish_if_stmt (stmt);
12842 if (BIND_EXPR_BODY_BLOCK (t))
12843 stmt = begin_function_body ();
12845 stmt = begin_compound_stmt (BIND_EXPR_TRY_BLOCK (t)
12846 ? BCS_TRY_BLOCK : 0);
12848 RECUR (BIND_EXPR_BODY (t));
12850 if (BIND_EXPR_BODY_BLOCK (t))
12851 finish_function_body (stmt);
12853 finish_compound_stmt (stmt);
12857 finish_break_stmt ();
12860 case CONTINUE_STMT:
12861 finish_continue_stmt ();
12865 stmt = begin_switch_stmt ();
12866 tmp = RECUR (SWITCH_STMT_COND (t));
12867 finish_switch_cond (tmp, stmt);
12868 RECUR (SWITCH_STMT_BODY (t));
12869 finish_switch_stmt (stmt);
12872 case CASE_LABEL_EXPR:
12873 finish_case_label (EXPR_LOCATION (t),
12874 RECUR (CASE_LOW (t)),
12875 RECUR (CASE_HIGH (t)));
12880 tree decl = LABEL_EXPR_LABEL (t);
12883 label = finish_label_stmt (DECL_NAME (decl));
12884 if (DECL_ATTRIBUTES (decl) != NULL_TREE)
12885 cplus_decl_attributes (&label, DECL_ATTRIBUTES (decl), 0);
12890 tmp = GOTO_DESTINATION (t);
12891 if (TREE_CODE (tmp) != LABEL_DECL)
12892 /* Computed goto's must be tsubst'd into. On the other hand,
12893 non-computed gotos must not be; the identifier in question
12894 will have no binding. */
12897 tmp = DECL_NAME (tmp);
12898 finish_goto_stmt (tmp);
12902 tmp = finish_asm_stmt
12903 (ASM_VOLATILE_P (t),
12904 RECUR (ASM_STRING (t)),
12905 tsubst_copy_asm_operands (ASM_OUTPUTS (t), args, complain, in_decl),
12906 tsubst_copy_asm_operands (ASM_INPUTS (t), args, complain, in_decl),
12907 tsubst_copy_asm_operands (ASM_CLOBBERS (t), args, complain, in_decl),
12908 tsubst_copy_asm_operands (ASM_LABELS (t), args, complain, in_decl));
12910 tree asm_expr = tmp;
12911 if (TREE_CODE (asm_expr) == CLEANUP_POINT_EXPR)
12912 asm_expr = TREE_OPERAND (asm_expr, 0);
12913 ASM_INPUT_P (asm_expr) = ASM_INPUT_P (t);
12920 stmt = begin_try_block ();
12921 RECUR (TRY_STMTS (t));
12922 finish_cleanup_try_block (stmt);
12923 finish_cleanup (RECUR (TRY_HANDLERS (t)), stmt);
12927 tree compound_stmt = NULL_TREE;
12929 if (FN_TRY_BLOCK_P (t))
12930 stmt = begin_function_try_block (&compound_stmt);
12932 stmt = begin_try_block ();
12934 RECUR (TRY_STMTS (t));
12936 if (FN_TRY_BLOCK_P (t))
12937 finish_function_try_block (stmt);
12939 finish_try_block (stmt);
12941 RECUR (TRY_HANDLERS (t));
12942 if (FN_TRY_BLOCK_P (t))
12943 finish_function_handler_sequence (stmt, compound_stmt);
12945 finish_handler_sequence (stmt);
12951 tree decl = HANDLER_PARMS (t);
12955 decl = tsubst (decl, args, complain, in_decl);
12956 /* Prevent instantiate_decl from trying to instantiate
12957 this variable. We've already done all that needs to be
12959 if (decl != error_mark_node)
12960 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
12962 stmt = begin_handler ();
12963 finish_handler_parms (decl, stmt);
12964 RECUR (HANDLER_BODY (t));
12965 finish_handler (stmt);
12970 tsubst (TREE_TYPE (t), args, complain, NULL_TREE);
12973 case STATIC_ASSERT:
12976 tsubst_expr (STATIC_ASSERT_CONDITION (t),
12979 /*integral_constant_expression_p=*/true);
12980 finish_static_assert (condition,
12981 STATIC_ASSERT_MESSAGE (t),
12982 STATIC_ASSERT_SOURCE_LOCATION (t),
12983 /*member_p=*/false);
12988 tmp = tsubst_omp_clauses (OMP_PARALLEL_CLAUSES (t),
12989 args, complain, in_decl);
12990 stmt = begin_omp_parallel ();
12991 RECUR (OMP_PARALLEL_BODY (t));
12992 OMP_PARALLEL_COMBINED (finish_omp_parallel (tmp, stmt))
12993 = OMP_PARALLEL_COMBINED (t);
12997 tmp = tsubst_omp_clauses (OMP_TASK_CLAUSES (t),
12998 args, complain, in_decl);
12999 stmt = begin_omp_task ();
13000 RECUR (OMP_TASK_BODY (t));
13001 finish_omp_task (tmp, stmt);
13006 tree clauses, body, pre_body;
13007 tree declv, initv, condv, incrv;
13010 clauses = tsubst_omp_clauses (OMP_FOR_CLAUSES (t),
13011 args, complain, in_decl);
13012 declv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
13013 initv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
13014 condv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
13015 incrv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
13017 for (i = 0; i < TREE_VEC_LENGTH (OMP_FOR_INIT (t)); i++)
13018 tsubst_omp_for_iterator (t, i, declv, initv, condv, incrv,
13019 &clauses, args, complain, in_decl,
13020 integral_constant_expression_p);
13022 stmt = begin_omp_structured_block ();
13024 for (i = 0; i < TREE_VEC_LENGTH (initv); i++)
13025 if (TREE_VEC_ELT (initv, i) == NULL
13026 || TREE_CODE (TREE_VEC_ELT (initv, i)) != DECL_EXPR)
13027 TREE_VEC_ELT (initv, i) = RECUR (TREE_VEC_ELT (initv, i));
13028 else if (CLASS_TYPE_P (TREE_TYPE (TREE_VEC_ELT (initv, i))))
13030 tree init = RECUR (TREE_VEC_ELT (initv, i));
13031 gcc_assert (init == TREE_VEC_ELT (declv, i));
13032 TREE_VEC_ELT (initv, i) = NULL_TREE;
13036 tree decl_expr = TREE_VEC_ELT (initv, i);
13037 tree init = DECL_INITIAL (DECL_EXPR_DECL (decl_expr));
13038 gcc_assert (init != NULL);
13039 TREE_VEC_ELT (initv, i) = RECUR (init);
13040 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = NULL;
13042 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = init;
13045 pre_body = push_stmt_list ();
13046 RECUR (OMP_FOR_PRE_BODY (t));
13047 pre_body = pop_stmt_list (pre_body);
13049 body = push_stmt_list ();
13050 RECUR (OMP_FOR_BODY (t));
13051 body = pop_stmt_list (body);
13053 t = finish_omp_for (EXPR_LOCATION (t), declv, initv, condv, incrv,
13054 body, pre_body, clauses);
13056 add_stmt (finish_omp_structured_block (stmt));
13062 tmp = tsubst_omp_clauses (OMP_CLAUSES (t), args, complain, in_decl);
13063 stmt = push_stmt_list ();
13064 RECUR (OMP_BODY (t));
13065 stmt = pop_stmt_list (stmt);
13068 OMP_BODY (t) = stmt;
13069 OMP_CLAUSES (t) = tmp;
13077 stmt = push_stmt_list ();
13078 RECUR (OMP_BODY (t));
13079 stmt = pop_stmt_list (stmt);
13082 OMP_BODY (t) = stmt;
13087 gcc_assert (OMP_ATOMIC_DEPENDENT_P (t));
13088 if (TREE_CODE (TREE_OPERAND (t, 1)) != MODIFY_EXPR)
13090 tree op1 = TREE_OPERAND (t, 1);
13091 tree rhs1 = NULL_TREE;
13093 if (TREE_CODE (op1) == COMPOUND_EXPR)
13095 rhs1 = RECUR (TREE_OPERAND (op1, 0));
13096 op1 = TREE_OPERAND (op1, 1);
13098 lhs = RECUR (TREE_OPERAND (op1, 0));
13099 rhs = RECUR (TREE_OPERAND (op1, 1));
13100 finish_omp_atomic (OMP_ATOMIC, TREE_CODE (op1), lhs, rhs,
13101 NULL_TREE, NULL_TREE, rhs1);
13105 tree op1 = TREE_OPERAND (t, 1);
13106 tree v = NULL_TREE, lhs, rhs = NULL_TREE, lhs1 = NULL_TREE;
13107 tree rhs1 = NULL_TREE;
13108 enum tree_code code = TREE_CODE (TREE_OPERAND (op1, 1));
13109 enum tree_code opcode = NOP_EXPR;
13110 if (code == OMP_ATOMIC_READ)
13112 v = RECUR (TREE_OPERAND (op1, 0));
13113 lhs = RECUR (TREE_OPERAND (TREE_OPERAND (op1, 1), 0));
13115 else if (code == OMP_ATOMIC_CAPTURE_OLD
13116 || code == OMP_ATOMIC_CAPTURE_NEW)
13118 tree op11 = TREE_OPERAND (TREE_OPERAND (op1, 1), 1);
13119 v = RECUR (TREE_OPERAND (op1, 0));
13120 lhs1 = RECUR (TREE_OPERAND (TREE_OPERAND (op1, 1), 0));
13121 if (TREE_CODE (op11) == COMPOUND_EXPR)
13123 rhs1 = RECUR (TREE_OPERAND (op11, 0));
13124 op11 = TREE_OPERAND (op11, 1);
13126 lhs = RECUR (TREE_OPERAND (op11, 0));
13127 rhs = RECUR (TREE_OPERAND (op11, 1));
13128 opcode = TREE_CODE (op11);
13133 lhs = RECUR (TREE_OPERAND (op1, 0));
13134 rhs = RECUR (TREE_OPERAND (op1, 1));
13136 finish_omp_atomic (code, opcode, lhs, rhs, v, lhs1, rhs1);
13140 case TRANSACTION_EXPR:
13143 flags |= (TRANSACTION_EXPR_OUTER (t) ? TM_STMT_ATTR_OUTER : 0);
13144 flags |= (TRANSACTION_EXPR_RELAXED (t) ? TM_STMT_ATTR_RELAXED : 0);
13146 if (TRANSACTION_EXPR_IS_STMT (t))
13148 stmt = begin_transaction_stmt (input_location, NULL, flags);
13149 RECUR (TRANSACTION_EXPR_BODY (t));
13150 finish_transaction_stmt (stmt, NULL, flags);
13154 stmt = build_transaction_expr (EXPR_LOCATION (t),
13155 RECUR (TRANSACTION_EXPR_BODY (t)),
13162 case EXPR_PACK_EXPANSION:
13163 error ("invalid use of pack expansion expression");
13164 return error_mark_node;
13166 case NONTYPE_ARGUMENT_PACK:
13167 error ("use %<...%> to expand argument pack");
13168 return error_mark_node;
13171 gcc_assert (!STATEMENT_CODE_P (TREE_CODE (t)));
13173 return tsubst_copy_and_build (t, args, complain, in_decl,
13174 /*function_p=*/false,
13175 integral_constant_expression_p);
13182 /* T is a postfix-expression that is not being used in a function
13183 call. Return the substituted version of T. */
13186 tsubst_non_call_postfix_expression (tree t, tree args,
13187 tsubst_flags_t complain,
13190 if (TREE_CODE (t) == SCOPE_REF)
13191 t = tsubst_qualified_id (t, args, complain, in_decl,
13192 /*done=*/false, /*address_p=*/false);
13194 t = tsubst_copy_and_build (t, args, complain, in_decl,
13195 /*function_p=*/false,
13196 /*integral_constant_expression_p=*/false);
13201 /* Like tsubst but deals with expressions and performs semantic
13202 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
13205 tsubst_copy_and_build (tree t,
13207 tsubst_flags_t complain,
13210 bool integral_constant_expression_p)
13212 #define RECUR(NODE) \
13213 tsubst_copy_and_build (NODE, args, complain, in_decl, \
13214 /*function_p=*/false, \
13215 integral_constant_expression_p)
13219 if (t == NULL_TREE || t == error_mark_node)
13222 switch (TREE_CODE (t))
13226 /* Fall through. */
13227 case IDENTIFIER_NODE:
13231 bool non_integral_constant_expression_p;
13232 const char *error_msg;
13234 if (IDENTIFIER_TYPENAME_P (t))
13236 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
13237 t = mangle_conv_op_name_for_type (new_type);
13240 /* Look up the name. */
13241 decl = lookup_name (t);
13243 /* By convention, expressions use ERROR_MARK_NODE to indicate
13244 failure, not NULL_TREE. */
13245 if (decl == NULL_TREE)
13246 decl = error_mark_node;
13248 decl = finish_id_expression (t, decl, NULL_TREE,
13250 integral_constant_expression_p,
13251 /*allow_non_integral_constant_expression_p=*/(cxx_dialect >= cxx0x),
13252 &non_integral_constant_expression_p,
13253 /*template_p=*/false,
13255 /*address_p=*/false,
13256 /*template_arg_p=*/false,
13261 if (!function_p && TREE_CODE (decl) == IDENTIFIER_NODE)
13263 if (complain & tf_error)
13264 unqualified_name_lookup_error (decl);
13265 decl = error_mark_node;
13270 case TEMPLATE_ID_EXPR:
13273 tree templ = RECUR (TREE_OPERAND (t, 0));
13274 tree targs = TREE_OPERAND (t, 1);
13277 targs = tsubst_template_args (targs, args, complain, in_decl);
13279 if (TREE_CODE (templ) == COMPONENT_REF)
13281 object = TREE_OPERAND (templ, 0);
13282 templ = TREE_OPERAND (templ, 1);
13285 object = NULL_TREE;
13286 templ = lookup_template_function (templ, targs);
13289 return build3 (COMPONENT_REF, TREE_TYPE (templ),
13290 object, templ, NULL_TREE);
13292 return baselink_for_fns (templ);
13297 tree r = RECUR (TREE_OPERAND (t, 0));
13299 if (REFERENCE_REF_P (t))
13301 /* A type conversion to reference type will be enclosed in
13302 such an indirect ref, but the substitution of the cast
13303 will have also added such an indirect ref. */
13304 if (TREE_CODE (TREE_TYPE (r)) == REFERENCE_TYPE)
13305 r = convert_from_reference (r);
13308 r = build_x_indirect_ref (r, RO_UNARY_STAR, complain);
13314 (tsubst (TREE_TYPE (t), args, complain, in_decl),
13315 RECUR (TREE_OPERAND (t, 0)));
13317 case IMPLICIT_CONV_EXPR:
13319 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
13320 tree expr = RECUR (TREE_OPERAND (t, 0));
13321 int flags = LOOKUP_IMPLICIT;
13322 if (IMPLICIT_CONV_EXPR_DIRECT_INIT (t))
13323 flags = LOOKUP_NORMAL;
13324 return perform_implicit_conversion_flags (type, expr, complain,
13331 tsubst (TREE_TYPE (t), args, complain, in_decl),
13332 RECUR (TREE_OPERAND (t, 0)));
13335 case REINTERPRET_CAST_EXPR:
13336 case CONST_CAST_EXPR:
13337 case DYNAMIC_CAST_EXPR:
13338 case STATIC_CAST_EXPR:
13343 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
13344 if (integral_constant_expression_p
13345 && !cast_valid_in_integral_constant_expression_p (type))
13347 if (complain & tf_error)
13348 error ("a cast to a type other than an integral or "
13349 "enumeration type cannot appear in a constant-expression");
13350 return error_mark_node;
13353 op = RECUR (TREE_OPERAND (t, 0));
13355 switch (TREE_CODE (t))
13358 return build_functional_cast (type, op, complain);
13359 case REINTERPRET_CAST_EXPR:
13360 return build_reinterpret_cast (type, op, complain);
13361 case CONST_CAST_EXPR:
13362 return build_const_cast (type, op, complain);
13363 case DYNAMIC_CAST_EXPR:
13364 return build_dynamic_cast (type, op, complain);
13365 case STATIC_CAST_EXPR:
13366 return build_static_cast (type, op, complain);
13368 gcc_unreachable ();
13372 case POSTDECREMENT_EXPR:
13373 case POSTINCREMENT_EXPR:
13374 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
13375 args, complain, in_decl);
13376 return build_x_unary_op (TREE_CODE (t), op1, complain);
13378 case PREDECREMENT_EXPR:
13379 case PREINCREMENT_EXPR:
13383 case TRUTH_NOT_EXPR:
13384 case UNARY_PLUS_EXPR: /* Unary + */
13385 case REALPART_EXPR:
13386 case IMAGPART_EXPR:
13387 return build_x_unary_op (TREE_CODE (t), RECUR (TREE_OPERAND (t, 0)),
13391 op1 = TREE_OPERAND (t, 0);
13392 if (TREE_CODE (op1) == LABEL_DECL)
13393 return finish_label_address_expr (DECL_NAME (op1),
13394 EXPR_LOCATION (op1));
13395 if (TREE_CODE (op1) == SCOPE_REF)
13396 op1 = tsubst_qualified_id (op1, args, complain, in_decl,
13397 /*done=*/true, /*address_p=*/true);
13399 op1 = tsubst_non_call_postfix_expression (op1, args, complain,
13401 return build_x_unary_op (ADDR_EXPR, op1, complain);
13406 case TRUNC_DIV_EXPR:
13407 case CEIL_DIV_EXPR:
13408 case FLOOR_DIV_EXPR:
13409 case ROUND_DIV_EXPR:
13410 case EXACT_DIV_EXPR:
13414 case TRUNC_MOD_EXPR:
13415 case FLOOR_MOD_EXPR:
13416 case TRUTH_ANDIF_EXPR:
13417 case TRUTH_ORIF_EXPR:
13418 case TRUTH_AND_EXPR:
13419 case TRUTH_OR_EXPR:
13434 return build_x_binary_op
13436 RECUR (TREE_OPERAND (t, 0)),
13437 (TREE_NO_WARNING (TREE_OPERAND (t, 0))
13439 : TREE_CODE (TREE_OPERAND (t, 0))),
13440 RECUR (TREE_OPERAND (t, 1)),
13441 (TREE_NO_WARNING (TREE_OPERAND (t, 1))
13443 : TREE_CODE (TREE_OPERAND (t, 1))),
13448 return tsubst_qualified_id (t, args, complain, in_decl, /*done=*/true,
13449 /*address_p=*/false);
13451 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
13452 args, complain, in_decl);
13453 return build_x_array_ref (op1, RECUR (TREE_OPERAND (t, 1)), complain);
13456 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
13457 return tsubst_copy (t, args, complain, in_decl);
13461 op1 = TREE_OPERAND (t, 0);
13464 /* When there are no ARGS, we are trying to evaluate a
13465 non-dependent expression from the parser. Trying to do
13466 the substitutions may not work. */
13468 op1 = TREE_TYPE (op1);
13472 ++cp_unevaluated_operand;
13473 ++c_inhibit_evaluation_warnings;
13474 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
13475 /*function_p=*/false,
13476 /*integral_constant_expression_p=*/false);
13477 --cp_unevaluated_operand;
13478 --c_inhibit_evaluation_warnings;
13481 return cxx_sizeof_or_alignof_type (op1, TREE_CODE (t),
13482 complain & tf_error);
13484 return cxx_sizeof_or_alignof_expr (op1, TREE_CODE (t),
13485 complain & tf_error);
13487 case AT_ENCODE_EXPR:
13489 op1 = TREE_OPERAND (t, 0);
13490 ++cp_unevaluated_operand;
13491 ++c_inhibit_evaluation_warnings;
13492 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
13493 /*function_p=*/false,
13494 /*integral_constant_expression_p=*/false);
13495 --cp_unevaluated_operand;
13496 --c_inhibit_evaluation_warnings;
13497 return objc_build_encode_expr (op1);
13500 case NOEXCEPT_EXPR:
13501 op1 = TREE_OPERAND (t, 0);
13502 ++cp_unevaluated_operand;
13503 ++c_inhibit_evaluation_warnings;
13504 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
13505 /*function_p=*/false,
13506 /*integral_constant_expression_p=*/false);
13507 --cp_unevaluated_operand;
13508 --c_inhibit_evaluation_warnings;
13509 return finish_noexcept_expr (op1, complain);
13513 tree r = build_x_modify_expr
13514 (RECUR (TREE_OPERAND (t, 0)),
13515 TREE_CODE (TREE_OPERAND (t, 1)),
13516 RECUR (TREE_OPERAND (t, 2)),
13518 /* TREE_NO_WARNING must be set if either the expression was
13519 parenthesized or it uses an operator such as >>= rather
13520 than plain assignment. In the former case, it was already
13521 set and must be copied. In the latter case,
13522 build_x_modify_expr sets it and it must not be reset
13524 if (TREE_NO_WARNING (t))
13525 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
13530 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
13531 args, complain, in_decl);
13532 /* Remember that there was a reference to this entity. */
13535 return build_x_arrow (op1);
13539 tree placement = RECUR (TREE_OPERAND (t, 0));
13540 tree init = RECUR (TREE_OPERAND (t, 3));
13541 VEC(tree,gc) *placement_vec;
13542 VEC(tree,gc) *init_vec;
13545 if (placement == NULL_TREE)
13546 placement_vec = NULL;
13549 placement_vec = make_tree_vector ();
13550 for (; placement != NULL_TREE; placement = TREE_CHAIN (placement))
13551 VEC_safe_push (tree, gc, placement_vec, TREE_VALUE (placement));
13554 /* If there was an initializer in the original tree, but it
13555 instantiated to an empty list, then we should pass a
13556 non-NULL empty vector to tell build_new that it was an
13557 empty initializer() rather than no initializer. This can
13558 only happen when the initializer is a pack expansion whose
13559 parameter packs are of length zero. */
13560 if (init == NULL_TREE && TREE_OPERAND (t, 3) == NULL_TREE)
13564 init_vec = make_tree_vector ();
13565 if (init == void_zero_node)
13566 gcc_assert (init_vec != NULL);
13569 for (; init != NULL_TREE; init = TREE_CHAIN (init))
13570 VEC_safe_push (tree, gc, init_vec, TREE_VALUE (init));
13574 ret = build_new (&placement_vec,
13575 tsubst (TREE_OPERAND (t, 1), args, complain, in_decl),
13576 RECUR (TREE_OPERAND (t, 2)),
13578 NEW_EXPR_USE_GLOBAL (t),
13581 if (placement_vec != NULL)
13582 release_tree_vector (placement_vec);
13583 if (init_vec != NULL)
13584 release_tree_vector (init_vec);
13590 return delete_sanity
13591 (RECUR (TREE_OPERAND (t, 0)),
13592 RECUR (TREE_OPERAND (t, 1)),
13593 DELETE_EXPR_USE_VEC (t),
13594 DELETE_EXPR_USE_GLOBAL (t),
13597 case COMPOUND_EXPR:
13598 return build_x_compound_expr (RECUR (TREE_OPERAND (t, 0)),
13599 RECUR (TREE_OPERAND (t, 1)),
13605 VEC(tree,gc) *call_args;
13606 unsigned int nargs, i;
13611 function = CALL_EXPR_FN (t);
13612 /* When we parsed the expression, we determined whether or
13613 not Koenig lookup should be performed. */
13614 koenig_p = KOENIG_LOOKUP_P (t);
13615 if (TREE_CODE (function) == SCOPE_REF)
13617 qualified_p = true;
13618 function = tsubst_qualified_id (function, args, complain, in_decl,
13620 /*address_p=*/false);
13622 else if (koenig_p && TREE_CODE (function) == IDENTIFIER_NODE)
13624 /* Do nothing; calling tsubst_copy_and_build on an identifier
13625 would incorrectly perform unqualified lookup again.
13627 Note that we can also have an IDENTIFIER_NODE if the earlier
13628 unqualified lookup found a member function; in that case
13629 koenig_p will be false and we do want to do the lookup
13630 again to find the instantiated member function.
13632 FIXME but doing that causes c++/15272, so we need to stop
13633 using IDENTIFIER_NODE in that situation. */
13634 qualified_p = false;
13638 if (TREE_CODE (function) == COMPONENT_REF)
13640 tree op = TREE_OPERAND (function, 1);
13642 qualified_p = (TREE_CODE (op) == SCOPE_REF
13643 || (BASELINK_P (op)
13644 && BASELINK_QUALIFIED_P (op)));
13647 qualified_p = false;
13649 function = tsubst_copy_and_build (function, args, complain,
13652 integral_constant_expression_p);
13654 if (BASELINK_P (function))
13655 qualified_p = true;
13658 nargs = call_expr_nargs (t);
13659 call_args = make_tree_vector ();
13660 for (i = 0; i < nargs; ++i)
13662 tree arg = CALL_EXPR_ARG (t, i);
13664 if (!PACK_EXPANSION_P (arg))
13665 VEC_safe_push (tree, gc, call_args,
13666 RECUR (CALL_EXPR_ARG (t, i)));
13669 /* Expand the pack expansion and push each entry onto
13671 arg = tsubst_pack_expansion (arg, args, complain, in_decl);
13672 if (TREE_CODE (arg) == TREE_VEC)
13674 unsigned int len, j;
13676 len = TREE_VEC_LENGTH (arg);
13677 for (j = 0; j < len; ++j)
13679 tree value = TREE_VEC_ELT (arg, j);
13680 if (value != NULL_TREE)
13681 value = convert_from_reference (value);
13682 VEC_safe_push (tree, gc, call_args, value);
13687 /* A partial substitution. Add one entry. */
13688 VEC_safe_push (tree, gc, call_args, arg);
13693 /* We do not perform argument-dependent lookup if normal
13694 lookup finds a non-function, in accordance with the
13695 expected resolution of DR 218. */
13697 && ((is_overloaded_fn (function)
13698 /* If lookup found a member function, the Koenig lookup is
13699 not appropriate, even if an unqualified-name was used
13700 to denote the function. */
13701 && !DECL_FUNCTION_MEMBER_P (get_first_fn (function)))
13702 || TREE_CODE (function) == IDENTIFIER_NODE)
13703 /* Only do this when substitution turns a dependent call
13704 into a non-dependent call. */
13705 && type_dependent_expression_p_push (t)
13706 && !any_type_dependent_arguments_p (call_args))
13707 function = perform_koenig_lookup (function, call_args, false,
13710 if (TREE_CODE (function) == IDENTIFIER_NODE
13711 && !any_type_dependent_arguments_p (call_args))
13713 if (koenig_p && (complain & tf_warning_or_error))
13715 /* For backwards compatibility and good diagnostics, try
13716 the unqualified lookup again if we aren't in SFINAE
13718 tree unq = (tsubst_copy_and_build
13719 (function, args, complain, in_decl, true,
13720 integral_constant_expression_p));
13721 if (unq == error_mark_node)
13722 return error_mark_node;
13724 if (unq != function)
13727 if (TREE_CODE (fn) == INDIRECT_REF)
13728 fn = TREE_OPERAND (fn, 0);
13729 if (TREE_CODE (fn) == COMPONENT_REF)
13730 fn = TREE_OPERAND (fn, 1);
13731 if (is_overloaded_fn (fn))
13732 fn = get_first_fn (fn);
13733 permerror (EXPR_LOC_OR_HERE (t),
13734 "%qD was not declared in this scope, "
13735 "and no declarations were found by "
13736 "argument-dependent lookup at the point "
13737 "of instantiation", function);
13739 /* Can't say anything more. */;
13740 else if (DECL_CLASS_SCOPE_P (fn))
13742 inform (EXPR_LOC_OR_HERE (t),
13743 "declarations in dependent base %qT are "
13744 "not found by unqualified lookup",
13745 DECL_CLASS_CONTEXT (fn));
13746 if (current_class_ptr)
13747 inform (EXPR_LOC_OR_HERE (t),
13748 "use %<this->%D%> instead", function);
13750 inform (EXPR_LOC_OR_HERE (t),
13751 "use %<%T::%D%> instead",
13752 current_class_name, function);
13755 inform (0, "%q+D declared here, later in the "
13756 "translation unit", fn);
13760 if (TREE_CODE (function) == IDENTIFIER_NODE)
13762 unqualified_name_lookup_error (function);
13763 release_tree_vector (call_args);
13764 return error_mark_node;
13768 /* Remember that there was a reference to this entity. */
13769 if (DECL_P (function))
13770 mark_used (function);
13772 if (TREE_CODE (function) == OFFSET_REF)
13773 ret = build_offset_ref_call_from_tree (function, &call_args);
13774 else if (TREE_CODE (function) == COMPONENT_REF)
13776 tree instance = TREE_OPERAND (function, 0);
13777 tree fn = TREE_OPERAND (function, 1);
13779 if (processing_template_decl
13780 && (type_dependent_expression_p (instance)
13781 || (!BASELINK_P (fn)
13782 && TREE_CODE (fn) != FIELD_DECL)
13783 || type_dependent_expression_p (fn)
13784 || any_type_dependent_arguments_p (call_args)))
13785 ret = build_nt_call_vec (function, call_args);
13786 else if (!BASELINK_P (fn))
13787 ret = finish_call_expr (function, &call_args,
13788 /*disallow_virtual=*/false,
13789 /*koenig_p=*/false,
13792 ret = (build_new_method_call
13794 &call_args, NULL_TREE,
13795 qualified_p ? LOOKUP_NONVIRTUAL : LOOKUP_NORMAL,
13800 ret = finish_call_expr (function, &call_args,
13801 /*disallow_virtual=*/qualified_p,
13805 release_tree_vector (call_args);
13811 return build_x_conditional_expr
13812 (RECUR (TREE_OPERAND (t, 0)),
13813 RECUR (TREE_OPERAND (t, 1)),
13814 RECUR (TREE_OPERAND (t, 2)),
13817 case PSEUDO_DTOR_EXPR:
13818 return finish_pseudo_destructor_expr
13819 (RECUR (TREE_OPERAND (t, 0)),
13820 RECUR (TREE_OPERAND (t, 1)),
13821 tsubst (TREE_OPERAND (t, 2), args, complain, in_decl));
13825 tree purpose, value, chain;
13827 if (t == void_list_node)
13830 if ((TREE_PURPOSE (t) && PACK_EXPANSION_P (TREE_PURPOSE (t)))
13831 || (TREE_VALUE (t) && PACK_EXPANSION_P (TREE_VALUE (t))))
13833 /* We have pack expansions, so expand those and
13834 create a new list out of it. */
13835 tree purposevec = NULL_TREE;
13836 tree valuevec = NULL_TREE;
13840 /* Expand the argument expressions. */
13841 if (TREE_PURPOSE (t))
13842 purposevec = tsubst_pack_expansion (TREE_PURPOSE (t), args,
13843 complain, in_decl);
13844 if (TREE_VALUE (t))
13845 valuevec = tsubst_pack_expansion (TREE_VALUE (t), args,
13846 complain, in_decl);
13848 /* Build the rest of the list. */
13849 chain = TREE_CHAIN (t);
13850 if (chain && chain != void_type_node)
13851 chain = RECUR (chain);
13853 /* Determine the number of arguments. */
13854 if (purposevec && TREE_CODE (purposevec) == TREE_VEC)
13856 len = TREE_VEC_LENGTH (purposevec);
13857 gcc_assert (!valuevec || len == TREE_VEC_LENGTH (valuevec));
13859 else if (TREE_CODE (valuevec) == TREE_VEC)
13860 len = TREE_VEC_LENGTH (valuevec);
13863 /* Since we only performed a partial substitution into
13864 the argument pack, we only return a single list
13866 if (purposevec == TREE_PURPOSE (t)
13867 && valuevec == TREE_VALUE (t)
13868 && chain == TREE_CHAIN (t))
13871 return tree_cons (purposevec, valuevec, chain);
13874 /* Convert the argument vectors into a TREE_LIST */
13878 /* Grab the Ith values. */
13880 purpose = purposevec ? TREE_VEC_ELT (purposevec, i)
13883 = valuevec ? convert_from_reference (TREE_VEC_ELT (valuevec, i))
13886 /* Build the list (backwards). */
13887 chain = tree_cons (purpose, value, chain);
13893 purpose = TREE_PURPOSE (t);
13895 purpose = RECUR (purpose);
13896 value = TREE_VALUE (t);
13898 value = RECUR (value);
13899 chain = TREE_CHAIN (t);
13900 if (chain && chain != void_type_node)
13901 chain = RECUR (chain);
13902 if (purpose == TREE_PURPOSE (t)
13903 && value == TREE_VALUE (t)
13904 && chain == TREE_CHAIN (t))
13906 return tree_cons (purpose, value, chain);
13909 case COMPONENT_REF:
13915 object = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
13916 args, complain, in_decl);
13917 /* Remember that there was a reference to this entity. */
13918 if (DECL_P (object))
13919 mark_used (object);
13920 object_type = TREE_TYPE (object);
13922 member = TREE_OPERAND (t, 1);
13923 if (BASELINK_P (member))
13924 member = tsubst_baselink (member,
13925 non_reference (TREE_TYPE (object)),
13926 args, complain, in_decl);
13928 member = tsubst_copy (member, args, complain, in_decl);
13929 if (member == error_mark_node)
13930 return error_mark_node;
13932 if (type_dependent_expression_p (object))
13933 /* We can't do much here. */;
13934 else if (!CLASS_TYPE_P (object_type))
13936 if (SCALAR_TYPE_P (object_type))
13938 tree s = NULL_TREE;
13939 tree dtor = member;
13941 if (TREE_CODE (dtor) == SCOPE_REF)
13943 s = TREE_OPERAND (dtor, 0);
13944 dtor = TREE_OPERAND (dtor, 1);
13946 if (TREE_CODE (dtor) == BIT_NOT_EXPR)
13948 dtor = TREE_OPERAND (dtor, 0);
13950 return finish_pseudo_destructor_expr (object, s, dtor);
13954 else if (TREE_CODE (member) == SCOPE_REF
13955 && TREE_CODE (TREE_OPERAND (member, 1)) == TEMPLATE_ID_EXPR)
13957 /* Lookup the template functions now that we know what the
13959 tree scope = TREE_OPERAND (member, 0);
13960 tree tmpl = TREE_OPERAND (TREE_OPERAND (member, 1), 0);
13961 tree args = TREE_OPERAND (TREE_OPERAND (member, 1), 1);
13962 member = lookup_qualified_name (scope, tmpl,
13963 /*is_type_p=*/false,
13964 /*complain=*/false);
13965 if (BASELINK_P (member))
13967 BASELINK_FUNCTIONS (member)
13968 = build_nt (TEMPLATE_ID_EXPR, BASELINK_FUNCTIONS (member),
13970 member = (adjust_result_of_qualified_name_lookup
13971 (member, BINFO_TYPE (BASELINK_BINFO (member)),
13976 qualified_name_lookup_error (scope, tmpl, member,
13978 return error_mark_node;
13981 else if (TREE_CODE (member) == SCOPE_REF
13982 && !CLASS_TYPE_P (TREE_OPERAND (member, 0))
13983 && TREE_CODE (TREE_OPERAND (member, 0)) != NAMESPACE_DECL)
13985 if (complain & tf_error)
13987 if (TYPE_P (TREE_OPERAND (member, 0)))
13988 error ("%qT is not a class or namespace",
13989 TREE_OPERAND (member, 0));
13991 error ("%qD is not a class or namespace",
13992 TREE_OPERAND (member, 0));
13994 return error_mark_node;
13996 else if (TREE_CODE (member) == FIELD_DECL)
13997 return finish_non_static_data_member (member, object, NULL_TREE);
13999 return finish_class_member_access_expr (object, member,
14000 /*template_p=*/false,
14006 (RECUR (TREE_OPERAND (t, 0)));
14010 VEC(constructor_elt,gc) *n;
14011 constructor_elt *ce;
14012 unsigned HOST_WIDE_INT idx;
14013 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
14014 bool process_index_p;
14016 bool need_copy_p = false;
14019 if (type == error_mark_node)
14020 return error_mark_node;
14022 /* digest_init will do the wrong thing if we let it. */
14023 if (type && TYPE_PTRMEMFUNC_P (type))
14026 /* We do not want to process the index of aggregate
14027 initializers as they are identifier nodes which will be
14028 looked up by digest_init. */
14029 process_index_p = !(type && MAYBE_CLASS_TYPE_P (type));
14031 n = VEC_copy (constructor_elt, gc, CONSTRUCTOR_ELTS (t));
14032 newlen = VEC_length (constructor_elt, n);
14033 FOR_EACH_VEC_ELT (constructor_elt, n, idx, ce)
14035 if (ce->index && process_index_p)
14036 ce->index = RECUR (ce->index);
14038 if (PACK_EXPANSION_P (ce->value))
14040 /* Substitute into the pack expansion. */
14041 ce->value = tsubst_pack_expansion (ce->value, args, complain,
14044 if (ce->value == error_mark_node
14045 || PACK_EXPANSION_P (ce->value))
14047 else if (TREE_VEC_LENGTH (ce->value) == 1)
14048 /* Just move the argument into place. */
14049 ce->value = TREE_VEC_ELT (ce->value, 0);
14052 /* Update the length of the final CONSTRUCTOR
14053 arguments vector, and note that we will need to
14055 newlen = newlen + TREE_VEC_LENGTH (ce->value) - 1;
14056 need_copy_p = true;
14060 ce->value = RECUR (ce->value);
14065 VEC(constructor_elt,gc) *old_n = n;
14067 n = VEC_alloc (constructor_elt, gc, newlen);
14068 FOR_EACH_VEC_ELT (constructor_elt, old_n, idx, ce)
14070 if (TREE_CODE (ce->value) == TREE_VEC)
14072 int i, len = TREE_VEC_LENGTH (ce->value);
14073 for (i = 0; i < len; ++i)
14074 CONSTRUCTOR_APPEND_ELT (n, 0,
14075 TREE_VEC_ELT (ce->value, i));
14078 CONSTRUCTOR_APPEND_ELT (n, 0, ce->value);
14082 r = build_constructor (init_list_type_node, n);
14083 CONSTRUCTOR_IS_DIRECT_INIT (r) = CONSTRUCTOR_IS_DIRECT_INIT (t);
14085 if (TREE_HAS_CONSTRUCTOR (t))
14086 return finish_compound_literal (type, r, complain);
14088 TREE_TYPE (r) = type;
14094 tree operand_0 = TREE_OPERAND (t, 0);
14095 if (TYPE_P (operand_0))
14097 operand_0 = tsubst (operand_0, args, complain, in_decl);
14098 return get_typeid (operand_0);
14102 operand_0 = RECUR (operand_0);
14103 return build_typeid (operand_0);
14114 tree r = tsubst_copy (t, args, complain, in_decl);
14116 if (TREE_CODE (TREE_TYPE (t)) != REFERENCE_TYPE)
14117 /* If the original type was a reference, we'll be wrapped in
14118 the appropriate INDIRECT_REF. */
14119 r = convert_from_reference (r);
14124 return build_x_va_arg (RECUR (TREE_OPERAND (t, 0)),
14125 tsubst (TREE_TYPE (t), args, complain, in_decl));
14127 case OFFSETOF_EXPR:
14128 return finish_offsetof (RECUR (TREE_OPERAND (t, 0)));
14132 tree type1 = tsubst_copy (TRAIT_EXPR_TYPE1 (t), args,
14133 complain, in_decl);
14135 tree type2 = TRAIT_EXPR_TYPE2 (t);
14137 type2 = tsubst_copy (type2, args, complain, in_decl);
14139 return finish_trait_expr (TRAIT_EXPR_KIND (t), type1, type2);
14144 tree old_stmt_expr = cur_stmt_expr;
14145 tree stmt_expr = begin_stmt_expr ();
14147 cur_stmt_expr = stmt_expr;
14148 tsubst_expr (STMT_EXPR_STMT (t), args, complain, in_decl,
14149 integral_constant_expression_p);
14150 stmt_expr = finish_stmt_expr (stmt_expr, false);
14151 cur_stmt_expr = old_stmt_expr;
14153 /* If the resulting list of expression statement is empty,
14154 fold it further into void_zero_node. */
14155 if (empty_expr_stmt_p (stmt_expr))
14156 stmt_expr = void_zero_node;
14162 t = tsubst_copy (t, args, complain, in_decl);
14163 /* As in finish_id_expression, we resolve enumeration constants
14164 to their underlying values. */
14165 if (TREE_CODE (t) == CONST_DECL && !processing_template_decl)
14167 used_types_insert (TREE_TYPE (t));
14168 return DECL_INITIAL (t);
14174 tree r = build_lambda_expr ();
14176 tree type = tsubst (LAMBDA_EXPR_CLOSURE (t), args, complain, NULL_TREE);
14177 LAMBDA_EXPR_CLOSURE (r) = type;
14178 CLASSTYPE_LAMBDA_EXPR (type) = r;
14180 LAMBDA_EXPR_LOCATION (r)
14181 = LAMBDA_EXPR_LOCATION (t);
14182 LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (r)
14183 = LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (t);
14184 LAMBDA_EXPR_MUTABLE_P (r) = LAMBDA_EXPR_MUTABLE_P (t);
14185 LAMBDA_EXPR_DISCRIMINATOR (r)
14186 = (LAMBDA_EXPR_DISCRIMINATOR (t));
14187 LAMBDA_EXPR_EXTRA_SCOPE (r)
14188 = RECUR (LAMBDA_EXPR_EXTRA_SCOPE (t));
14189 if (LAMBDA_EXPR_RETURN_TYPE (t) == dependent_lambda_return_type_node)
14191 LAMBDA_EXPR_RETURN_TYPE (r) = dependent_lambda_return_type_node;
14192 LAMBDA_EXPR_DEDUCE_RETURN_TYPE_P (r) = true;
14195 LAMBDA_EXPR_RETURN_TYPE (r)
14196 = tsubst (LAMBDA_EXPR_RETURN_TYPE (t), args, complain, in_decl);
14198 gcc_assert (LAMBDA_EXPR_THIS_CAPTURE (t) == NULL_TREE
14199 && LAMBDA_EXPR_PENDING_PROXIES (t) == NULL);
14201 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
14202 determine_visibility (TYPE_NAME (type));
14203 /* Now that we know visibility, instantiate the type so we have a
14204 declaration of the op() for later calls to lambda_function. */
14205 complete_type (type);
14207 /* The capture list refers to closure members, so this needs to
14208 wait until after we finish instantiating the type. */
14209 LAMBDA_EXPR_CAPTURE_LIST (r)
14210 = RECUR (LAMBDA_EXPR_CAPTURE_LIST (t));
14212 return build_lambda_object (r);
14216 /* We can get here for a constant initializer of non-dependent type.
14217 FIXME stop folding in cp_parser_initializer_clause. */
14218 gcc_assert (TREE_CONSTANT (t));
14220 tree r = get_target_expr (RECUR (TARGET_EXPR_INITIAL (t)));
14221 TREE_CONSTANT (r) = true;
14226 /* Handle Objective-C++ constructs, if appropriate. */
14229 = objcp_tsubst_copy_and_build (t, args, complain,
14230 in_decl, /*function_p=*/false);
14234 return tsubst_copy (t, args, complain, in_decl);
14240 /* Verify that the instantiated ARGS are valid. For type arguments,
14241 make sure that the type's linkage is ok. For non-type arguments,
14242 make sure they are constants if they are integral or enumerations.
14243 Emit an error under control of COMPLAIN, and return TRUE on error. */
14246 check_instantiated_arg (tree tmpl, tree t, tsubst_flags_t complain)
14248 if (ARGUMENT_PACK_P (t))
14250 tree vec = ARGUMENT_PACK_ARGS (t);
14251 int len = TREE_VEC_LENGTH (vec);
14252 bool result = false;
14255 for (i = 0; i < len; ++i)
14256 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (vec, i), complain))
14260 else if (TYPE_P (t))
14262 /* [basic.link]: A name with no linkage (notably, the name
14263 of a class or enumeration declared in a local scope)
14264 shall not be used to declare an entity with linkage.
14265 This implies that names with no linkage cannot be used as
14268 DR 757 relaxes this restriction for C++0x. */
14269 tree nt = (cxx_dialect > cxx98 ? NULL_TREE
14270 : no_linkage_check (t, /*relaxed_p=*/false));
14274 /* DR 488 makes use of a type with no linkage cause
14275 type deduction to fail. */
14276 if (complain & tf_error)
14278 if (TYPE_ANONYMOUS_P (nt))
14279 error ("%qT is/uses anonymous type", t);
14281 error ("template argument for %qD uses local type %qT",
14286 /* In order to avoid all sorts of complications, we do not
14287 allow variably-modified types as template arguments. */
14288 else if (variably_modified_type_p (t, NULL_TREE))
14290 if (complain & tf_error)
14291 error ("%qT is a variably modified type", t);
14295 /* A non-type argument of integral or enumerated type must be a
14297 else if (TREE_TYPE (t)
14298 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t))
14299 && !TREE_CONSTANT (t))
14301 if (complain & tf_error)
14302 error ("integral expression %qE is not constant", t);
14309 check_instantiated_args (tree tmpl, tree args, tsubst_flags_t complain)
14311 int ix, len = DECL_NTPARMS (tmpl);
14312 bool result = false;
14314 for (ix = 0; ix != len; ix++)
14316 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (args, ix), complain))
14319 if (result && (complain & tf_error))
14320 error (" trying to instantiate %qD", tmpl);
14324 /* In C++0x, it's possible to have a function template whose type depends
14325 on itself recursively. This is most obvious with decltype, but can also
14326 occur with enumeration scope (c++/48969). So we need to catch infinite
14327 recursion and reject the substitution at deduction time; this function
14328 will return error_mark_node for any repeated substitution.
14330 This also catches excessive recursion such as when f<N> depends on
14331 f<N-1> across all integers, and returns error_mark_node for all the
14332 substitutions back up to the initial one.
14334 This is, of course, not reentrant. */
14337 deduction_tsubst_fntype (tree fn, tree targs, tsubst_flags_t complain)
14339 static bool excessive_deduction_depth;
14340 static int deduction_depth;
14341 struct pending_template *old_last_pend = last_pending_template;
14342 struct tinst_level *old_error_tinst = last_error_tinst_level;
14344 tree fntype = TREE_TYPE (fn);
14348 if (excessive_deduction_depth)
14349 return error_mark_node;
14351 tinst = build_tree_list (fn, targs);
14352 if (!push_tinst_level (tinst))
14354 excessive_deduction_depth = true;
14356 return error_mark_node;
14359 input_location = DECL_SOURCE_LOCATION (fn);
14361 push_deduction_access_scope (fn);
14362 r = tsubst (fntype, targs, complain, NULL_TREE);
14363 pop_deduction_access_scope (fn);
14366 if (excessive_deduction_depth)
14368 r = error_mark_node;
14369 if (deduction_depth == 0)
14370 /* Reset once we're all the way out. */
14371 excessive_deduction_depth = false;
14374 pop_tinst_level ();
14375 /* We can't free this if a pending_template entry or last_error_tinst_level
14376 is pointing at it. */
14377 if (last_pending_template == old_last_pend
14378 && last_error_tinst_level == old_error_tinst)
14383 /* Instantiate the indicated variable or function template TMPL with
14384 the template arguments in TARG_PTR. */
14387 instantiate_template_1 (tree tmpl, tree orig_args, tsubst_flags_t complain)
14389 tree targ_ptr = orig_args;
14393 HOST_WIDE_INT saved_processing_template_decl;
14395 if (tmpl == error_mark_node)
14396 return error_mark_node;
14398 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
14400 /* If this function is a clone, handle it specially. */
14401 if (DECL_CLONED_FUNCTION_P (tmpl))
14406 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
14407 DECL_CLONED_FUNCTION. */
14408 spec = instantiate_template (DECL_ABSTRACT_ORIGIN (tmpl),
14409 targ_ptr, complain);
14410 if (spec == error_mark_node)
14411 return error_mark_node;
14413 /* Look for the clone. */
14414 FOR_EACH_CLONE (clone, spec)
14415 if (DECL_NAME (clone) == DECL_NAME (tmpl))
14417 /* We should always have found the clone by now. */
14418 gcc_unreachable ();
14422 /* Check to see if we already have this specialization. */
14423 gen_tmpl = most_general_template (tmpl);
14424 if (tmpl != gen_tmpl)
14425 /* The TMPL is a partial instantiation. To get a full set of
14426 arguments we must add the arguments used to perform the
14427 partial instantiation. */
14428 targ_ptr = add_outermost_template_args (DECL_TI_ARGS (tmpl),
14431 /* It would be nice to avoid hashing here and then again in tsubst_decl,
14432 but it doesn't seem to be on the hot path. */
14433 spec = retrieve_specialization (gen_tmpl, targ_ptr, 0);
14435 gcc_assert (tmpl == gen_tmpl
14436 || ((fndecl = retrieve_specialization (tmpl, orig_args, 0))
14438 || fndecl == NULL_TREE);
14440 if (spec != NULL_TREE)
14443 if (check_instantiated_args (gen_tmpl, INNERMOST_TEMPLATE_ARGS (targ_ptr),
14445 return error_mark_node;
14447 /* We are building a FUNCTION_DECL, during which the access of its
14448 parameters and return types have to be checked. However this
14449 FUNCTION_DECL which is the desired context for access checking
14450 is not built yet. We solve this chicken-and-egg problem by
14451 deferring all checks until we have the FUNCTION_DECL. */
14452 push_deferring_access_checks (dk_deferred);
14454 /* Although PROCESSING_TEMPLATE_DECL may be true at this point
14455 (because, for example, we have encountered a non-dependent
14456 function call in the body of a template function and must now
14457 determine which of several overloaded functions will be called),
14458 within the instantiation itself we are not processing a
14460 saved_processing_template_decl = processing_template_decl;
14461 processing_template_decl = 0;
14462 /* Substitute template parameters to obtain the specialization. */
14463 fndecl = tsubst (DECL_TEMPLATE_RESULT (gen_tmpl),
14464 targ_ptr, complain, gen_tmpl);
14465 processing_template_decl = saved_processing_template_decl;
14466 if (fndecl == error_mark_node)
14467 return error_mark_node;
14469 /* Now we know the specialization, compute access previously
14471 push_access_scope (fndecl);
14473 /* Some typedefs referenced from within the template code need to be access
14474 checked at template instantiation time, i.e now. These types were
14475 added to the template at parsing time. Let's get those and perfom
14476 the acces checks then. */
14477 perform_typedefs_access_check (DECL_TEMPLATE_RESULT (tmpl), targ_ptr);
14478 perform_deferred_access_checks ();
14479 pop_access_scope (fndecl);
14480 pop_deferring_access_checks ();
14482 /* The DECL_TI_TEMPLATE should always be the immediate parent
14483 template, not the most general template. */
14484 DECL_TI_TEMPLATE (fndecl) = tmpl;
14486 /* If we've just instantiated the main entry point for a function,
14487 instantiate all the alternate entry points as well. We do this
14488 by cloning the instantiation of the main entry point, not by
14489 instantiating the template clones. */
14490 if (DECL_CHAIN (gen_tmpl) && DECL_CLONED_FUNCTION_P (DECL_CHAIN (gen_tmpl)))
14491 clone_function_decl (fndecl, /*update_method_vec_p=*/0);
14496 /* Wrapper for instantiate_template_1. */
14499 instantiate_template (tree tmpl, tree orig_args, tsubst_flags_t complain)
14502 timevar_push (TV_TEMPLATE_INST);
14503 ret = instantiate_template_1 (tmpl, orig_args, complain);
14504 timevar_pop (TV_TEMPLATE_INST);
14508 /* We're going to do deduction substitution on the type of TMPL, a function
14509 template. In C++11 mode, push into that access scope. In C++03 mode,
14510 disable access checking. */
14513 push_deduction_access_scope (tree tmpl)
14515 if (cxx_dialect >= cxx0x)
14517 int ptd = processing_template_decl;
14518 push_access_scope (DECL_TEMPLATE_RESULT (tmpl));
14519 /* Preserve processing_template_decl across push_to_top_level. */
14520 if (ptd && !processing_template_decl)
14521 ++processing_template_decl;
14524 push_deferring_access_checks (dk_no_check);
14527 /* And pop back out. */
14530 pop_deduction_access_scope (tree tmpl)
14532 if (cxx_dialect >= cxx0x)
14533 pop_access_scope (DECL_TEMPLATE_RESULT (tmpl));
14535 pop_deferring_access_checks ();
14538 /* PARM is a template parameter pack for FN. Returns true iff
14539 PARM is used in a deducible way in the argument list of FN. */
14542 pack_deducible_p (tree parm, tree fn)
14544 tree t = FUNCTION_FIRST_USER_PARMTYPE (fn);
14545 for (; t; t = TREE_CHAIN (t))
14547 tree type = TREE_VALUE (t);
14549 if (!PACK_EXPANSION_P (type))
14551 for (packs = PACK_EXPANSION_PARAMETER_PACKS (type);
14552 packs; packs = TREE_CHAIN (packs))
14553 if (TREE_VALUE (packs) == parm)
14555 /* The template parameter pack is used in a function parameter
14556 pack. If this is the end of the parameter list, the
14557 template parameter pack is deducible. */
14558 if (TREE_CHAIN (t) == void_list_node)
14561 /* Otherwise, not. Well, it could be deduced from
14562 a non-pack parameter, but doing so would end up with
14563 a deduction mismatch, so don't bother. */
14567 /* The template parameter pack isn't used in any function parameter
14568 packs, but it might be used deeper, e.g. tuple<Args...>. */
14572 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
14573 NARGS elements of the arguments that are being used when calling
14574 it. TARGS is a vector into which the deduced template arguments
14577 Return zero for success, 2 for an incomplete match that doesn't resolve
14578 all the types, and 1 for complete failure. An error message will be
14579 printed only for an incomplete match.
14581 If FN is a conversion operator, or we are trying to produce a specific
14582 specialization, RETURN_TYPE is the return type desired.
14584 The EXPLICIT_TARGS are explicit template arguments provided via a
14587 The parameter STRICT is one of:
14590 We are deducing arguments for a function call, as in
14591 [temp.deduct.call].
14594 We are deducing arguments for a conversion function, as in
14595 [temp.deduct.conv].
14598 We are deducing arguments when doing an explicit instantiation
14599 as in [temp.explicit], when determining an explicit specialization
14600 as in [temp.expl.spec], or when taking the address of a function
14601 template, as in [temp.deduct.funcaddr]. */
14604 fn_type_unification (tree fn,
14605 tree explicit_targs,
14608 unsigned int nargs,
14610 unification_kind_t strict,
14618 gcc_assert (TREE_CODE (fn) == TEMPLATE_DECL);
14620 fntype = TREE_TYPE (fn);
14621 if (explicit_targs)
14625 The specified template arguments must match the template
14626 parameters in kind (i.e., type, nontype, template), and there
14627 must not be more arguments than there are parameters;
14628 otherwise type deduction fails.
14630 Nontype arguments must match the types of the corresponding
14631 nontype template parameters, or must be convertible to the
14632 types of the corresponding nontype parameters as specified in
14633 _temp.arg.nontype_, otherwise type deduction fails.
14635 All references in the function type of the function template
14636 to the corresponding template parameters are replaced by the
14637 specified template argument values. If a substitution in a
14638 template parameter or in the function type of the function
14639 template results in an invalid type, type deduction fails. */
14640 tree tparms = DECL_INNERMOST_TEMPLATE_PARMS (fn);
14641 int i, len = TREE_VEC_LENGTH (tparms);
14642 tree converted_args;
14643 bool incomplete = false;
14645 if (explicit_targs == error_mark_node)
14646 return unify_invalid (explain_p);
14649 = (coerce_template_parms (tparms, explicit_targs, NULL_TREE,
14651 ? tf_warning_or_error
14653 /*require_all_args=*/false,
14654 /*use_default_args=*/false));
14655 if (converted_args == error_mark_node)
14658 /* Substitute the explicit args into the function type. This is
14659 necessary so that, for instance, explicitly declared function
14660 arguments can match null pointed constants. If we were given
14661 an incomplete set of explicit args, we must not do semantic
14662 processing during substitution as we could create partial
14664 for (i = 0; i < len; i++)
14666 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
14667 bool parameter_pack = false;
14668 tree targ = TREE_VEC_ELT (converted_args, i);
14670 /* Dig out the actual parm. */
14671 if (TREE_CODE (parm) == TYPE_DECL
14672 || TREE_CODE (parm) == TEMPLATE_DECL)
14674 parm = TREE_TYPE (parm);
14675 parameter_pack = TEMPLATE_TYPE_PARAMETER_PACK (parm);
14677 else if (TREE_CODE (parm) == PARM_DECL)
14679 parm = DECL_INITIAL (parm);
14680 parameter_pack = TEMPLATE_PARM_PARAMETER_PACK (parm);
14683 if (!parameter_pack && targ == NULL_TREE)
14684 /* No explicit argument for this template parameter. */
14687 if (parameter_pack && pack_deducible_p (parm, fn))
14689 /* Mark the argument pack as "incomplete". We could
14690 still deduce more arguments during unification.
14691 We remove this mark in type_unification_real. */
14694 ARGUMENT_PACK_INCOMPLETE_P(targ) = 1;
14695 ARGUMENT_PACK_EXPLICIT_ARGS (targ)
14696 = ARGUMENT_PACK_ARGS (targ);
14699 /* We have some incomplete argument packs. */
14704 processing_template_decl += incomplete;
14705 fntype = deduction_tsubst_fntype (fn, converted_args,
14707 ? tf_warning_or_error
14709 processing_template_decl -= incomplete;
14711 if (fntype == error_mark_node)
14714 /* Place the explicitly specified arguments in TARGS. */
14715 for (i = NUM_TMPL_ARGS (converted_args); i--;)
14716 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (converted_args, i);
14719 /* Never do unification on the 'this' parameter. */
14720 parms = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (fntype));
14726 parms = tree_cons (NULL_TREE, TREE_TYPE (fntype), parms);
14727 new_args = XALLOCAVEC (tree, nargs + 1);
14728 new_args[0] = return_type;
14729 memcpy (new_args + 1, args, nargs * sizeof (tree));
14734 /* We allow incomplete unification without an error message here
14735 because the standard doesn't seem to explicitly prohibit it. Our
14736 callers must be ready to deal with unification failures in any
14738 result = type_unification_real (DECL_INNERMOST_TEMPLATE_PARMS (fn),
14739 targs, parms, args, nargs, /*subr=*/0,
14740 strict, flags, explain_p);
14742 /* Now that we have bindings for all of the template arguments,
14743 ensure that the arguments deduced for the template template
14744 parameters have compatible template parameter lists. We cannot
14745 check this property before we have deduced all template
14746 arguments, because the template parameter types of a template
14747 template parameter might depend on prior template parameters
14748 deduced after the template template parameter. The following
14749 ill-formed example illustrates this issue:
14751 template<typename T, template<T> class C> void f(C<5>, T);
14753 template<int N> struct X {};
14756 f(X<5>(), 5l); // error: template argument deduction fails
14759 The template parameter list of 'C' depends on the template type
14760 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
14761 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
14762 time that we deduce 'C'. */
14764 && !template_template_parm_bindings_ok_p
14765 (DECL_INNERMOST_TEMPLATE_PARMS (fn), targs))
14766 return unify_inconsistent_template_template_parameters (explain_p);
14769 /* All is well so far. Now, check:
14773 When all template arguments have been deduced, all uses of
14774 template parameters in nondeduced contexts are replaced with
14775 the corresponding deduced argument values. If the
14776 substitution results in an invalid type, as described above,
14777 type deduction fails. */
14779 tree substed = deduction_tsubst_fntype (fn, targs,
14781 ? tf_warning_or_error
14783 if (substed == error_mark_node)
14786 /* If we're looking for an exact match, check that what we got
14787 is indeed an exact match. It might not be if some template
14788 parameters are used in non-deduced contexts. */
14789 if (strict == DEDUCE_EXACT)
14794 = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (substed));
14796 sarg = tree_cons (NULL_TREE, TREE_TYPE (substed), sarg);
14797 for (i = 0; i < nargs && sarg; ++i, sarg = TREE_CHAIN (sarg))
14798 if (!same_type_p (args[i], TREE_VALUE (sarg)))
14799 return unify_type_mismatch (explain_p, args[i],
14800 TREE_VALUE (sarg));
14807 /* Adjust types before performing type deduction, as described in
14808 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
14809 sections are symmetric. PARM is the type of a function parameter
14810 or the return type of the conversion function. ARG is the type of
14811 the argument passed to the call, or the type of the value
14812 initialized with the result of the conversion function.
14813 ARG_EXPR is the original argument expression, which may be null. */
14816 maybe_adjust_types_for_deduction (unification_kind_t strict,
14830 /* Swap PARM and ARG throughout the remainder of this
14831 function; the handling is precisely symmetric since PARM
14832 will initialize ARG rather than vice versa. */
14840 /* Core issue #873: Do the DR606 thing (see below) for these cases,
14841 too, but here handle it by stripping the reference from PARM
14842 rather than by adding it to ARG. */
14843 if (TREE_CODE (*parm) == REFERENCE_TYPE
14844 && TYPE_REF_IS_RVALUE (*parm)
14845 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
14846 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
14847 && TREE_CODE (*arg) == REFERENCE_TYPE
14848 && !TYPE_REF_IS_RVALUE (*arg))
14849 *parm = TREE_TYPE (*parm);
14850 /* Nothing else to do in this case. */
14854 gcc_unreachable ();
14857 if (TREE_CODE (*parm) != REFERENCE_TYPE)
14859 /* [temp.deduct.call]
14861 If P is not a reference type:
14863 --If A is an array type, the pointer type produced by the
14864 array-to-pointer standard conversion (_conv.array_) is
14865 used in place of A for type deduction; otherwise,
14867 --If A is a function type, the pointer type produced by
14868 the function-to-pointer standard conversion
14869 (_conv.func_) is used in place of A for type deduction;
14872 --If A is a cv-qualified type, the top level
14873 cv-qualifiers of A's type are ignored for type
14875 if (TREE_CODE (*arg) == ARRAY_TYPE)
14876 *arg = build_pointer_type (TREE_TYPE (*arg));
14877 else if (TREE_CODE (*arg) == FUNCTION_TYPE)
14878 *arg = build_pointer_type (*arg);
14880 *arg = TYPE_MAIN_VARIANT (*arg);
14883 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
14884 of the form T&&, where T is a template parameter, and the argument
14885 is an lvalue, T is deduced as A& */
14886 if (TREE_CODE (*parm) == REFERENCE_TYPE
14887 && TYPE_REF_IS_RVALUE (*parm)
14888 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
14889 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
14890 && (arg_expr ? real_lvalue_p (arg_expr)
14891 /* try_one_overload doesn't provide an arg_expr, but
14892 functions are always lvalues. */
14893 : TREE_CODE (*arg) == FUNCTION_TYPE))
14894 *arg = build_reference_type (*arg);
14896 /* [temp.deduct.call]
14898 If P is a cv-qualified type, the top level cv-qualifiers
14899 of P's type are ignored for type deduction. If P is a
14900 reference type, the type referred to by P is used for
14902 *parm = TYPE_MAIN_VARIANT (*parm);
14903 if (TREE_CODE (*parm) == REFERENCE_TYPE)
14905 *parm = TREE_TYPE (*parm);
14906 result |= UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
14909 /* DR 322. For conversion deduction, remove a reference type on parm
14910 too (which has been swapped into ARG). */
14911 if (strict == DEDUCE_CONV && TREE_CODE (*arg) == REFERENCE_TYPE)
14912 *arg = TREE_TYPE (*arg);
14917 /* Subroutine of unify_one_argument. PARM is a function parameter of a
14918 template which does contain any deducible template parameters; check if
14919 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
14920 unify_one_argument. */
14923 check_non_deducible_conversion (tree parm, tree arg, int strict,
14924 int flags, bool explain_p)
14929 type = TREE_TYPE (arg);
14933 if (same_type_p (parm, type))
14934 return unify_success (explain_p);
14936 if (strict == DEDUCE_CONV)
14938 if (can_convert_arg (type, parm, NULL_TREE, flags))
14939 return unify_success (explain_p);
14941 else if (strict != DEDUCE_EXACT)
14943 if (can_convert_arg (parm, type,
14944 TYPE_P (arg) ? NULL_TREE : arg,
14946 return unify_success (explain_p);
14949 if (strict == DEDUCE_EXACT)
14950 return unify_type_mismatch (explain_p, parm, arg);
14952 return unify_arg_conversion (explain_p, parm, type, arg);
14955 /* Subroutine of type_unification_real and unify_pack_expansion to
14956 handle unification of a single P/A pair. Parameters are as
14957 for those functions. */
14960 unify_one_argument (tree tparms, tree targs, tree parm, tree arg,
14961 int subr, unification_kind_t strict, int flags,
14964 tree arg_expr = NULL_TREE;
14967 if (arg == error_mark_node || parm == error_mark_node)
14968 return unify_invalid (explain_p);
14969 if (arg == unknown_type_node)
14970 /* We can't deduce anything from this, but we might get all the
14971 template args from other function args. */
14972 return unify_success (explain_p);
14974 /* FIXME uses_deducible_template_parms */
14975 if (TYPE_P (parm) && !uses_template_parms (parm))
14976 return check_non_deducible_conversion (parm, arg, strict, flags,
14982 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
14983 | UNIFY_ALLOW_MORE_CV_QUAL
14984 | UNIFY_ALLOW_DERIVED);
14988 arg_strict = UNIFY_ALLOW_LESS_CV_QUAL;
14992 arg_strict = UNIFY_ALLOW_NONE;
14996 gcc_unreachable ();
14999 /* We only do these transformations if this is the top-level
15000 parameter_type_list in a call or declaration matching; in other
15001 situations (nested function declarators, template argument lists) we
15002 won't be comparing a type to an expression, and we don't do any type
15008 gcc_assert (TREE_TYPE (arg) != NULL_TREE);
15009 if (type_unknown_p (arg))
15011 /* [temp.deduct.type] A template-argument can be
15012 deduced from a pointer to function or pointer
15013 to member function argument if the set of
15014 overloaded functions does not contain function
15015 templates and at most one of a set of
15016 overloaded functions provides a unique
15019 if (resolve_overloaded_unification
15020 (tparms, targs, parm, arg, strict,
15021 arg_strict, explain_p))
15022 return unify_success (explain_p);
15023 return unify_overload_resolution_failure (explain_p, arg);
15027 arg = unlowered_expr_type (arg);
15028 if (arg == error_mark_node)
15029 return unify_invalid (explain_p);
15033 maybe_adjust_types_for_deduction (strict, &parm, &arg, arg_expr);
15036 gcc_assert ((TYPE_P (parm) || TREE_CODE (parm) == TEMPLATE_DECL)
15037 == (TYPE_P (arg) || TREE_CODE (arg) == TEMPLATE_DECL));
15039 /* For deduction from an init-list we need the actual list. */
15040 if (arg_expr && BRACE_ENCLOSED_INITIALIZER_P (arg_expr))
15042 return unify (tparms, targs, parm, arg, arg_strict, explain_p);
15045 /* Most parms like fn_type_unification.
15047 If SUBR is 1, we're being called recursively (to unify the
15048 arguments of a function or method parameter of a function
15052 type_unification_real (tree tparms,
15056 unsigned int xnargs,
15058 unification_kind_t strict,
15064 int ntparms = TREE_VEC_LENGTH (tparms);
15065 int saw_undeduced = 0;
15068 unsigned int nargs;
15071 gcc_assert (TREE_CODE (tparms) == TREE_VEC);
15072 gcc_assert (xparms == NULL_TREE || TREE_CODE (xparms) == TREE_LIST);
15073 gcc_assert (ntparms > 0);
15075 /* Reset the number of non-defaulted template arguments contained
15077 NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs) = NULL_TREE;
15085 while (parms && parms != void_list_node
15088 parm = TREE_VALUE (parms);
15090 if (TREE_CODE (parm) == TYPE_PACK_EXPANSION
15091 && (!TREE_CHAIN (parms) || TREE_CHAIN (parms) == void_list_node))
15092 /* For a function parameter pack that occurs at the end of the
15093 parameter-declaration-list, the type A of each remaining
15094 argument of the call is compared with the type P of the
15095 declarator-id of the function parameter pack. */
15098 parms = TREE_CHAIN (parms);
15100 if (TREE_CODE (parm) == TYPE_PACK_EXPANSION)
15101 /* For a function parameter pack that does not occur at the
15102 end of the parameter-declaration-list, the type of the
15103 parameter pack is a non-deduced context. */
15109 if (unify_one_argument (tparms, targs, parm, arg, subr, strict,
15115 && parms != void_list_node
15116 && TREE_CODE (TREE_VALUE (parms)) == TYPE_PACK_EXPANSION)
15118 /* Unify the remaining arguments with the pack expansion type. */
15120 tree parmvec = make_tree_vec (1);
15122 /* Allocate a TREE_VEC and copy in all of the arguments */
15123 argvec = make_tree_vec (nargs - ia);
15124 for (i = 0; ia < nargs; ++ia, ++i)
15125 TREE_VEC_ELT (argvec, i) = args[ia];
15127 /* Copy the parameter into parmvec. */
15128 TREE_VEC_ELT (parmvec, 0) = TREE_VALUE (parms);
15129 if (unify_pack_expansion (tparms, targs, parmvec, argvec, strict,
15130 /*subr=*/subr, explain_p))
15133 /* Advance to the end of the list of parameters. */
15134 parms = TREE_CHAIN (parms);
15137 /* Fail if we've reached the end of the parm list, and more args
15138 are present, and the parm list isn't variadic. */
15139 if (ia < nargs && parms == void_list_node)
15140 return unify_too_many_arguments (explain_p, nargs, ia);
15141 /* Fail if parms are left and they don't have default values. */
15142 if (parms && parms != void_list_node
15143 && TREE_PURPOSE (parms) == NULL_TREE)
15145 unsigned int count = nargs;
15147 while (p && p != void_list_node)
15150 p = TREE_CHAIN (p);
15152 return unify_too_few_arguments (explain_p, ia, count);
15157 tsubst_flags_t complain = (explain_p
15158 ? tf_warning_or_error
15161 /* Check to see if we need another pass before we start clearing
15162 ARGUMENT_PACK_INCOMPLETE_P. */
15163 for (i = 0; i < ntparms; i++)
15165 tree targ = TREE_VEC_ELT (targs, i);
15166 tree tparm = TREE_VEC_ELT (tparms, i);
15168 if (targ || tparm == error_mark_node)
15170 tparm = TREE_VALUE (tparm);
15172 /* If this is an undeduced nontype parameter that depends on
15173 a type parameter, try another pass; its type may have been
15174 deduced from a later argument than the one from which
15175 this parameter can be deduced. */
15176 if (TREE_CODE (tparm) == PARM_DECL
15177 && uses_template_parms (TREE_TYPE (tparm))
15178 && !saw_undeduced++)
15182 for (i = 0; i < ntparms; i++)
15184 tree targ = TREE_VEC_ELT (targs, i);
15185 tree tparm = TREE_VEC_ELT (tparms, i);
15187 /* Clear the "incomplete" flags on all argument packs now so that
15188 substituting them into later default arguments works. */
15189 if (targ && ARGUMENT_PACK_P (targ))
15191 ARGUMENT_PACK_INCOMPLETE_P (targ) = 0;
15192 ARGUMENT_PACK_EXPLICIT_ARGS (targ) = NULL_TREE;
15195 if (targ || tparm == error_mark_node)
15197 tparm = TREE_VALUE (tparm);
15199 /* Core issue #226 (C++0x) [temp.deduct]:
15201 If a template argument has not been deduced, its
15202 default template argument, if any, is used.
15204 When we are in C++98 mode, TREE_PURPOSE will either
15205 be NULL_TREE or ERROR_MARK_NODE, so we do not need
15206 to explicitly check cxx_dialect here. */
15207 if (TREE_PURPOSE (TREE_VEC_ELT (tparms, i)))
15209 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
15210 tree arg = TREE_PURPOSE (TREE_VEC_ELT (tparms, i));
15211 arg = tsubst_template_arg (arg, targs, complain, NULL_TREE);
15212 arg = convert_template_argument (parm, arg, targs, complain,
15214 if (arg == error_mark_node)
15218 TREE_VEC_ELT (targs, i) = arg;
15219 /* The position of the first default template argument,
15220 is also the number of non-defaulted arguments in TARGS.
15222 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs))
15223 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, i);
15228 /* If the type parameter is a parameter pack, then it will
15229 be deduced to an empty parameter pack. */
15230 if (template_parameter_pack_p (tparm))
15234 if (TREE_CODE (tparm) == TEMPLATE_PARM_INDEX)
15236 arg = make_node (NONTYPE_ARGUMENT_PACK);
15237 TREE_TYPE (arg) = TREE_TYPE (TEMPLATE_PARM_DECL (tparm));
15238 TREE_CONSTANT (arg) = 1;
15241 arg = cxx_make_type (TYPE_ARGUMENT_PACK);
15243 SET_ARGUMENT_PACK_ARGS (arg, make_tree_vec (0));
15245 TREE_VEC_ELT (targs, i) = arg;
15249 return unify_parameter_deduction_failure (explain_p, tparm);
15252 #ifdef ENABLE_CHECKING
15253 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs))
15254 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, TREE_VEC_LENGTH (targs));
15257 return unify_success (explain_p);
15260 /* Subroutine of type_unification_real. Args are like the variables
15261 at the call site. ARG is an overloaded function (or template-id);
15262 we try deducing template args from each of the overloads, and if
15263 only one succeeds, we go with that. Modifies TARGS and returns
15264 true on success. */
15267 resolve_overloaded_unification (tree tparms,
15271 unification_kind_t strict,
15275 tree tempargs = copy_node (targs);
15277 tree goodfn = NULL_TREE;
15280 if (TREE_CODE (arg) == ADDR_EXPR)
15282 arg = TREE_OPERAND (arg, 0);
15288 if (TREE_CODE (arg) == COMPONENT_REF)
15289 /* Handle `&x' where `x' is some static or non-static member
15291 arg = TREE_OPERAND (arg, 1);
15293 if (TREE_CODE (arg) == OFFSET_REF)
15294 arg = TREE_OPERAND (arg, 1);
15296 /* Strip baselink information. */
15297 if (BASELINK_P (arg))
15298 arg = BASELINK_FUNCTIONS (arg);
15300 if (TREE_CODE (arg) == TEMPLATE_ID_EXPR)
15302 /* If we got some explicit template args, we need to plug them into
15303 the affected templates before we try to unify, in case the
15304 explicit args will completely resolve the templates in question. */
15307 tree expl_subargs = TREE_OPERAND (arg, 1);
15308 arg = TREE_OPERAND (arg, 0);
15310 for (; arg; arg = OVL_NEXT (arg))
15312 tree fn = OVL_CURRENT (arg);
15313 tree subargs, elem;
15315 if (TREE_CODE (fn) != TEMPLATE_DECL)
15318 ++processing_template_decl;
15319 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
15320 expl_subargs, /*check_ret=*/false);
15321 if (subargs && !any_dependent_template_arguments_p (subargs))
15323 elem = tsubst (TREE_TYPE (fn), subargs, tf_none, NULL_TREE);
15324 if (try_one_overload (tparms, targs, tempargs, parm,
15325 elem, strict, sub_strict, addr_p, explain_p)
15326 && (!goodfn || !decls_match (goodfn, elem)))
15334 --processing_template_decl;
15336 /* If no templates (or more than one) are fully resolved by the
15337 explicit arguments, this template-id is a non-deduced context; it
15338 could still be OK if we deduce all template arguments for the
15339 enclosing call through other arguments. */
15343 else if (TREE_CODE (arg) != OVERLOAD
15344 && TREE_CODE (arg) != FUNCTION_DECL)
15345 /* If ARG is, for example, "(0, &f)" then its type will be unknown
15346 -- but the deduction does not succeed because the expression is
15347 not just the function on its own. */
15350 for (; arg; arg = OVL_NEXT (arg))
15351 if (try_one_overload (tparms, targs, tempargs, parm,
15352 TREE_TYPE (OVL_CURRENT (arg)),
15353 strict, sub_strict, addr_p, explain_p)
15354 && (!goodfn || !decls_match (goodfn, OVL_CURRENT (arg))))
15356 goodfn = OVL_CURRENT (arg);
15360 /* [temp.deduct.type] A template-argument can be deduced from a pointer
15361 to function or pointer to member function argument if the set of
15362 overloaded functions does not contain function templates and at most
15363 one of a set of overloaded functions provides a unique match.
15365 So if we found multiple possibilities, we return success but don't
15366 deduce anything. */
15370 int i = TREE_VEC_LENGTH (targs);
15372 if (TREE_VEC_ELT (tempargs, i))
15373 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (tempargs, i);
15381 /* Core DR 115: In contexts where deduction is done and fails, or in
15382 contexts where deduction is not done, if a template argument list is
15383 specified and it, along with any default template arguments, identifies
15384 a single function template specialization, then the template-id is an
15385 lvalue for the function template specialization. */
15388 resolve_nondeduced_context (tree orig_expr)
15390 tree expr, offset, baselink;
15393 if (!type_unknown_p (orig_expr))
15398 offset = NULL_TREE;
15399 baselink = NULL_TREE;
15401 if (TREE_CODE (expr) == ADDR_EXPR)
15403 expr = TREE_OPERAND (expr, 0);
15406 if (TREE_CODE (expr) == OFFSET_REF)
15409 expr = TREE_OPERAND (expr, 1);
15411 if (BASELINK_P (expr))
15414 expr = BASELINK_FUNCTIONS (expr);
15417 if (TREE_CODE (expr) == TEMPLATE_ID_EXPR)
15420 tree goodfn = NULL_TREE;
15422 /* If we got some explicit template args, we need to plug them into
15423 the affected templates before we try to unify, in case the
15424 explicit args will completely resolve the templates in question. */
15426 tree expl_subargs = TREE_OPERAND (expr, 1);
15427 tree arg = TREE_OPERAND (expr, 0);
15428 tree badfn = NULL_TREE;
15429 tree badargs = NULL_TREE;
15431 for (; arg; arg = OVL_NEXT (arg))
15433 tree fn = OVL_CURRENT (arg);
15434 tree subargs, elem;
15436 if (TREE_CODE (fn) != TEMPLATE_DECL)
15439 ++processing_template_decl;
15440 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
15441 expl_subargs, /*check_ret=*/false);
15442 if (subargs && !any_dependent_template_arguments_p (subargs))
15444 elem = instantiate_template (fn, subargs, tf_none);
15445 if (elem == error_mark_node)
15450 else if (elem && (!goodfn || !decls_match (goodfn, elem)))
15456 --processing_template_decl;
15460 mark_used (goodfn);
15463 expr = build_baselink (BASELINK_BINFO (baselink),
15464 BASELINK_ACCESS_BINFO (baselink),
15465 expr, BASELINK_OPTYPE (baselink));
15469 = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (offset, 0)));
15470 expr = build_offset_ref (base, expr, addr);
15473 expr = cp_build_addr_expr (expr, tf_warning_or_error);
15476 else if (good == 0 && badargs)
15477 /* There were no good options and at least one bad one, so let the
15478 user know what the problem is. */
15479 instantiate_template (badfn, badargs, tf_warning_or_error);
15484 /* Subroutine of resolve_overloaded_unification; does deduction for a single
15485 overload. Fills TARGS with any deduced arguments, or error_mark_node if
15486 different overloads deduce different arguments for a given parm.
15487 ADDR_P is true if the expression for which deduction is being
15488 performed was of the form "& fn" rather than simply "fn".
15490 Returns 1 on success. */
15493 try_one_overload (tree tparms,
15498 unification_kind_t strict,
15507 /* [temp.deduct.type] A template-argument can be deduced from a pointer
15508 to function or pointer to member function argument if the set of
15509 overloaded functions does not contain function templates and at most
15510 one of a set of overloaded functions provides a unique match.
15512 So if this is a template, just return success. */
15514 if (uses_template_parms (arg))
15517 if (TREE_CODE (arg) == METHOD_TYPE)
15518 arg = build_ptrmemfunc_type (build_pointer_type (arg));
15520 arg = build_pointer_type (arg);
15522 sub_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg, NULL);
15524 /* We don't copy orig_targs for this because if we have already deduced
15525 some template args from previous args, unify would complain when we
15526 try to deduce a template parameter for the same argument, even though
15527 there isn't really a conflict. */
15528 nargs = TREE_VEC_LENGTH (targs);
15529 tempargs = make_tree_vec (nargs);
15531 if (unify (tparms, tempargs, parm, arg, sub_strict, explain_p))
15534 /* First make sure we didn't deduce anything that conflicts with
15535 explicitly specified args. */
15536 for (i = nargs; i--; )
15538 tree elt = TREE_VEC_ELT (tempargs, i);
15539 tree oldelt = TREE_VEC_ELT (orig_targs, i);
15543 else if (uses_template_parms (elt))
15544 /* Since we're unifying against ourselves, we will fill in
15545 template args used in the function parm list with our own
15546 template parms. Discard them. */
15547 TREE_VEC_ELT (tempargs, i) = NULL_TREE;
15548 else if (oldelt && !template_args_equal (oldelt, elt))
15552 for (i = nargs; i--; )
15554 tree elt = TREE_VEC_ELT (tempargs, i);
15557 TREE_VEC_ELT (targs, i) = elt;
15563 /* PARM is a template class (perhaps with unbound template
15564 parameters). ARG is a fully instantiated type. If ARG can be
15565 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
15566 TARGS are as for unify. */
15569 try_class_unification (tree tparms, tree targs, tree parm, tree arg,
15572 tree copy_of_targs;
15574 if (!CLASSTYPE_TEMPLATE_INFO (arg)
15575 || (most_general_template (CLASSTYPE_TI_TEMPLATE (arg))
15576 != most_general_template (CLASSTYPE_TI_TEMPLATE (parm))))
15579 /* We need to make a new template argument vector for the call to
15580 unify. If we used TARGS, we'd clutter it up with the result of
15581 the attempted unification, even if this class didn't work out.
15582 We also don't want to commit ourselves to all the unifications
15583 we've already done, since unification is supposed to be done on
15584 an argument-by-argument basis. In other words, consider the
15585 following pathological case:
15587 template <int I, int J, int K>
15590 template <int I, int J>
15591 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
15593 template <int I, int J, int K>
15594 void f(S<I, J, K>, S<I, I, I>);
15603 Now, by the time we consider the unification involving `s2', we
15604 already know that we must have `f<0, 0, 0>'. But, even though
15605 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
15606 because there are two ways to unify base classes of S<0, 1, 2>
15607 with S<I, I, I>. If we kept the already deduced knowledge, we
15608 would reject the possibility I=1. */
15609 copy_of_targs = make_tree_vec (TREE_VEC_LENGTH (targs));
15611 /* If unification failed, we're done. */
15612 if (unify (tparms, copy_of_targs, CLASSTYPE_TI_ARGS (parm),
15613 CLASSTYPE_TI_ARGS (arg), UNIFY_ALLOW_NONE, explain_p))
15619 /* Given a template type PARM and a class type ARG, find the unique
15620 base type in ARG that is an instance of PARM. We do not examine
15621 ARG itself; only its base-classes. If there is not exactly one
15622 appropriate base class, return NULL_TREE. PARM may be the type of
15623 a partial specialization, as well as a plain template type. Used
15626 static enum template_base_result
15627 get_template_base (tree tparms, tree targs, tree parm, tree arg,
15628 bool explain_p, tree *result)
15630 tree rval = NULL_TREE;
15633 gcc_assert (RECORD_OR_UNION_CODE_P (TREE_CODE (arg)));
15635 binfo = TYPE_BINFO (complete_type (arg));
15638 /* The type could not be completed. */
15639 *result = NULL_TREE;
15640 return tbr_incomplete_type;
15643 /* Walk in inheritance graph order. The search order is not
15644 important, and this avoids multiple walks of virtual bases. */
15645 for (binfo = TREE_CHAIN (binfo); binfo; binfo = TREE_CHAIN (binfo))
15647 tree r = try_class_unification (tparms, targs, parm,
15648 BINFO_TYPE (binfo), explain_p);
15652 /* If there is more than one satisfactory baseclass, then:
15656 If they yield more than one possible deduced A, the type
15660 if (rval && !same_type_p (r, rval))
15662 *result = NULL_TREE;
15663 return tbr_ambiguous_baseclass;
15671 return tbr_success;
15674 /* Returns the level of DECL, which declares a template parameter. */
15677 template_decl_level (tree decl)
15679 switch (TREE_CODE (decl))
15682 case TEMPLATE_DECL:
15683 return TEMPLATE_TYPE_LEVEL (TREE_TYPE (decl));
15686 return TEMPLATE_PARM_LEVEL (DECL_INITIAL (decl));
15689 gcc_unreachable ();
15694 /* Decide whether ARG can be unified with PARM, considering only the
15695 cv-qualifiers of each type, given STRICT as documented for unify.
15696 Returns nonzero iff the unification is OK on that basis. */
15699 check_cv_quals_for_unify (int strict, tree arg, tree parm)
15701 int arg_quals = cp_type_quals (arg);
15702 int parm_quals = cp_type_quals (parm);
15704 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
15705 && !(strict & UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
15707 /* Although a CVR qualifier is ignored when being applied to a
15708 substituted template parameter ([8.3.2]/1 for example), that
15709 does not allow us to unify "const T" with "int&" because both
15710 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
15711 It is ok when we're allowing additional CV qualifiers
15712 at the outer level [14.8.2.1]/3,1st bullet. */
15713 if ((TREE_CODE (arg) == REFERENCE_TYPE
15714 || TREE_CODE (arg) == FUNCTION_TYPE
15715 || TREE_CODE (arg) == METHOD_TYPE)
15716 && (parm_quals & (TYPE_QUAL_CONST | TYPE_QUAL_VOLATILE)))
15719 if ((!POINTER_TYPE_P (arg) && TREE_CODE (arg) != TEMPLATE_TYPE_PARM)
15720 && (parm_quals & TYPE_QUAL_RESTRICT))
15724 if (!(strict & (UNIFY_ALLOW_MORE_CV_QUAL | UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
15725 && (arg_quals & parm_quals) != parm_quals)
15728 if (!(strict & (UNIFY_ALLOW_LESS_CV_QUAL | UNIFY_ALLOW_OUTER_LESS_CV_QUAL))
15729 && (parm_quals & arg_quals) != arg_quals)
15735 /* Determines the LEVEL and INDEX for the template parameter PARM. */
15737 template_parm_level_and_index (tree parm, int* level, int* index)
15739 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
15740 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
15741 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
15743 *index = TEMPLATE_TYPE_IDX (parm);
15744 *level = TEMPLATE_TYPE_LEVEL (parm);
15748 *index = TEMPLATE_PARM_IDX (parm);
15749 *level = TEMPLATE_PARM_LEVEL (parm);
15753 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
15755 if (unify (TP, TA, P, A, S, EP)) \
15759 /* Unifies the remaining arguments in PACKED_ARGS with the pack
15760 expansion at the end of PACKED_PARMS. Returns 0 if the type
15761 deduction succeeds, 1 otherwise. STRICT is the same as in
15762 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
15763 call argument list. We'll need to adjust the arguments to make them
15764 types. SUBR tells us if this is from a recursive call to
15765 type_unification_real, or for comparing two template argument
15769 unify_pack_expansion (tree tparms, tree targs, tree packed_parms,
15770 tree packed_args, unification_kind_t strict,
15771 bool subr, bool explain_p)
15774 = TREE_VEC_ELT (packed_parms, TREE_VEC_LENGTH (packed_parms) - 1);
15775 tree pattern = PACK_EXPANSION_PATTERN (parm);
15776 tree pack, packs = NULL_TREE;
15777 int i, start = TREE_VEC_LENGTH (packed_parms) - 1;
15778 int len = TREE_VEC_LENGTH (packed_args);
15780 /* Determine the parameter packs we will be deducing from the
15781 pattern, and record their current deductions. */
15782 for (pack = PACK_EXPANSION_PARAMETER_PACKS (parm);
15783 pack; pack = TREE_CHAIN (pack))
15785 tree parm_pack = TREE_VALUE (pack);
15788 /* Determine the index and level of this parameter pack. */
15789 template_parm_level_and_index (parm_pack, &level, &idx);
15791 /* Keep track of the parameter packs and their corresponding
15793 packs = tree_cons (parm_pack, TMPL_ARG (targs, level, idx), packs);
15794 TREE_TYPE (packs) = make_tree_vec (len - start);
15797 /* Loop through all of the arguments that have not yet been
15798 unified and unify each with the pattern. */
15799 for (i = start; i < len; i++)
15802 bool any_explicit = false;
15803 tree arg = TREE_VEC_ELT (packed_args, i);
15805 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
15806 or the element of its argument pack at the current index if
15807 this argument was explicitly specified. */
15808 for (pack = packs; pack; pack = TREE_CHAIN (pack))
15812 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
15815 if (TREE_VALUE (pack)
15816 && (pargs = ARGUMENT_PACK_EXPLICIT_ARGS (TREE_VALUE (pack)))
15817 && (i < TREE_VEC_LENGTH (pargs)))
15819 any_explicit = true;
15820 arg = TREE_VEC_ELT (pargs, i);
15822 TMPL_ARG (targs, level, idx) = arg;
15825 /* If we had explicit template arguments, substitute them into the
15826 pattern before deduction. */
15829 /* Some arguments might still be unspecified or dependent. */
15831 ++processing_template_decl;
15832 dependent = any_dependent_template_arguments_p (targs);
15834 --processing_template_decl;
15835 parm = tsubst (pattern, targs,
15836 explain_p ? tf_warning_or_error : tf_none,
15839 --processing_template_decl;
15840 if (parm == error_mark_node)
15846 /* Unify the pattern with the current argument. */
15847 if (unify_one_argument (tparms, targs, parm, arg, subr, strict,
15848 LOOKUP_IMPLICIT, explain_p))
15851 /* For each parameter pack, collect the deduced value. */
15852 for (pack = packs; pack; pack = TREE_CHAIN (pack))
15855 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
15857 TREE_VEC_ELT (TREE_TYPE (pack), i - start) =
15858 TMPL_ARG (targs, level, idx);
15862 /* Verify that the results of unification with the parameter packs
15863 produce results consistent with what we've seen before, and make
15864 the deduced argument packs available. */
15865 for (pack = packs; pack; pack = TREE_CHAIN (pack))
15867 tree old_pack = TREE_VALUE (pack);
15868 tree new_args = TREE_TYPE (pack);
15869 int i, len = TREE_VEC_LENGTH (new_args);
15871 bool nondeduced_p = false;
15873 /* By default keep the original deduced argument pack.
15874 If necessary, more specific code is going to update the
15875 resulting deduced argument later down in this function. */
15876 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
15877 TMPL_ARG (targs, level, idx) = old_pack;
15879 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
15880 actually deduce anything. */
15881 for (i = 0; i < len && !nondeduced_p; ++i)
15882 if (TREE_VEC_ELT (new_args, i) == NULL_TREE)
15883 nondeduced_p = true;
15887 if (old_pack && ARGUMENT_PACK_INCOMPLETE_P (old_pack))
15889 /* If we had fewer function args than explicit template args,
15890 just use the explicits. */
15891 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
15892 int explicit_len = TREE_VEC_LENGTH (explicit_args);
15893 if (len < explicit_len)
15894 new_args = explicit_args;
15900 /* Build the deduced *_ARGUMENT_PACK. */
15901 if (TREE_CODE (TREE_PURPOSE (pack)) == TEMPLATE_PARM_INDEX)
15903 result = make_node (NONTYPE_ARGUMENT_PACK);
15904 TREE_TYPE (result) =
15905 TREE_TYPE (TEMPLATE_PARM_DECL (TREE_PURPOSE (pack)));
15906 TREE_CONSTANT (result) = 1;
15909 result = cxx_make_type (TYPE_ARGUMENT_PACK);
15911 SET_ARGUMENT_PACK_ARGS (result, new_args);
15913 /* Note the deduced argument packs for this parameter
15915 TMPL_ARG (targs, level, idx) = result;
15917 else if (ARGUMENT_PACK_INCOMPLETE_P (old_pack)
15918 && (ARGUMENT_PACK_ARGS (old_pack)
15919 == ARGUMENT_PACK_EXPLICIT_ARGS (old_pack)))
15921 /* We only had the explicitly-provided arguments before, but
15922 now we have a complete set of arguments. */
15923 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
15925 SET_ARGUMENT_PACK_ARGS (old_pack, new_args);
15926 ARGUMENT_PACK_INCOMPLETE_P (old_pack) = 1;
15927 ARGUMENT_PACK_EXPLICIT_ARGS (old_pack) = explicit_args;
15931 tree bad_old_arg = NULL_TREE, bad_new_arg = NULL_TREE;
15932 tree old_args = ARGUMENT_PACK_ARGS (old_pack);
15934 if (!comp_template_args_with_info (old_args, new_args,
15935 &bad_old_arg, &bad_new_arg))
15936 /* Inconsistent unification of this parameter pack. */
15937 return unify_parameter_pack_inconsistent (explain_p,
15943 return unify_success (explain_p);
15946 /* Deduce the value of template parameters. TPARMS is the (innermost)
15947 set of template parameters to a template. TARGS is the bindings
15948 for those template parameters, as determined thus far; TARGS may
15949 include template arguments for outer levels of template parameters
15950 as well. PARM is a parameter to a template function, or a
15951 subcomponent of that parameter; ARG is the corresponding argument.
15952 This function attempts to match PARM with ARG in a manner
15953 consistent with the existing assignments in TARGS. If more values
15954 are deduced, then TARGS is updated.
15956 Returns 0 if the type deduction succeeds, 1 otherwise. The
15957 parameter STRICT is a bitwise or of the following flags:
15960 Require an exact match between PARM and ARG.
15961 UNIFY_ALLOW_MORE_CV_QUAL:
15962 Allow the deduced ARG to be more cv-qualified (by qualification
15963 conversion) than ARG.
15964 UNIFY_ALLOW_LESS_CV_QUAL:
15965 Allow the deduced ARG to be less cv-qualified than ARG.
15966 UNIFY_ALLOW_DERIVED:
15967 Allow the deduced ARG to be a template base class of ARG,
15968 or a pointer to a template base class of the type pointed to by
15970 UNIFY_ALLOW_INTEGER:
15971 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
15972 case for more information.
15973 UNIFY_ALLOW_OUTER_LEVEL:
15974 This is the outermost level of a deduction. Used to determine validity
15975 of qualification conversions. A valid qualification conversion must
15976 have const qualified pointers leading up to the inner type which
15977 requires additional CV quals, except at the outer level, where const
15978 is not required [conv.qual]. It would be normal to set this flag in
15979 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
15980 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
15981 This is the outermost level of a deduction, and PARM can be more CV
15982 qualified at this point.
15983 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
15984 This is the outermost level of a deduction, and PARM can be less CV
15985 qualified at this point. */
15988 unify (tree tparms, tree targs, tree parm, tree arg, int strict,
15994 int strict_in = strict;
15996 /* I don't think this will do the right thing with respect to types.
15997 But the only case I've seen it in so far has been array bounds, where
15998 signedness is the only information lost, and I think that will be
16000 while (TREE_CODE (parm) == NOP_EXPR)
16001 parm = TREE_OPERAND (parm, 0);
16003 if (arg == error_mark_node)
16004 return unify_invalid (explain_p);
16005 if (arg == unknown_type_node
16006 || arg == init_list_type_node)
16007 /* We can't deduce anything from this, but we might get all the
16008 template args from other function args. */
16009 return unify_success (explain_p);
16011 /* If PARM uses template parameters, then we can't bail out here,
16012 even if ARG == PARM, since we won't record unifications for the
16013 template parameters. We might need them if we're trying to
16014 figure out which of two things is more specialized. */
16015 if (arg == parm && !uses_template_parms (parm))
16016 return unify_success (explain_p);
16018 /* Handle init lists early, so the rest of the function can assume
16019 we're dealing with a type. */
16020 if (BRACE_ENCLOSED_INITIALIZER_P (arg))
16024 tree orig_parm = parm;
16026 /* Replace T with std::initializer_list<T> for deduction. */
16027 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
16028 && flag_deduce_init_list)
16029 parm = listify (parm);
16031 if (!is_std_init_list (parm))
16032 /* We can only deduce from an initializer list argument if the
16033 parameter is std::initializer_list; otherwise this is a
16034 non-deduced context. */
16035 return unify_success (explain_p);
16037 elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (parm), 0);
16039 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg), i, elt)
16041 int elt_strict = strict;
16043 if (elt == error_mark_node)
16044 return unify_invalid (explain_p);
16046 if (!BRACE_ENCLOSED_INITIALIZER_P (elt))
16048 tree type = TREE_TYPE (elt);
16049 /* It should only be possible to get here for a call. */
16050 gcc_assert (elt_strict & UNIFY_ALLOW_OUTER_LEVEL);
16051 elt_strict |= maybe_adjust_types_for_deduction
16052 (DEDUCE_CALL, &elttype, &type, elt);
16056 RECUR_AND_CHECK_FAILURE (tparms, targs, elttype, elt, elt_strict,
16060 /* If the std::initializer_list<T> deduction worked, replace the
16061 deduced A with std::initializer_list<A>. */
16062 if (orig_parm != parm)
16064 idx = TEMPLATE_TYPE_IDX (orig_parm);
16065 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
16066 targ = listify (targ);
16067 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = targ;
16069 return unify_success (explain_p);
16072 /* Immediately reject some pairs that won't unify because of
16073 cv-qualification mismatches. */
16074 if (TREE_CODE (arg) == TREE_CODE (parm)
16076 /* It is the elements of the array which hold the cv quals of an array
16077 type, and the elements might be template type parms. We'll check
16078 when we recurse. */
16079 && TREE_CODE (arg) != ARRAY_TYPE
16080 /* We check the cv-qualifiers when unifying with template type
16081 parameters below. We want to allow ARG `const T' to unify with
16082 PARM `T' for example, when computing which of two templates
16083 is more specialized, for example. */
16084 && TREE_CODE (arg) != TEMPLATE_TYPE_PARM
16085 && !check_cv_quals_for_unify (strict_in, arg, parm))
16086 return unify_cv_qual_mismatch (explain_p, parm, arg);
16088 if (!(strict & UNIFY_ALLOW_OUTER_LEVEL)
16089 && TYPE_P (parm) && !CP_TYPE_CONST_P (parm))
16090 strict &= ~UNIFY_ALLOW_MORE_CV_QUAL;
16091 strict &= ~UNIFY_ALLOW_OUTER_LEVEL;
16092 strict &= ~UNIFY_ALLOW_DERIVED;
16093 strict &= ~UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
16094 strict &= ~UNIFY_ALLOW_OUTER_LESS_CV_QUAL;
16096 switch (TREE_CODE (parm))
16098 case TYPENAME_TYPE:
16100 case UNBOUND_CLASS_TEMPLATE:
16101 /* In a type which contains a nested-name-specifier, template
16102 argument values cannot be deduced for template parameters used
16103 within the nested-name-specifier. */
16104 return unify_success (explain_p);
16106 case TEMPLATE_TYPE_PARM:
16107 case TEMPLATE_TEMPLATE_PARM:
16108 case BOUND_TEMPLATE_TEMPLATE_PARM:
16109 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
16110 if (tparm == error_mark_node)
16111 return unify_invalid (explain_p);
16113 if (TEMPLATE_TYPE_LEVEL (parm)
16114 != template_decl_level (tparm))
16115 /* The PARM is not one we're trying to unify. Just check
16116 to see if it matches ARG. */
16118 if (TREE_CODE (arg) == TREE_CODE (parm)
16119 && same_type_p (parm, arg))
16120 return unify_success (explain_p);
16122 return unify_type_mismatch (explain_p, parm, arg);
16124 idx = TEMPLATE_TYPE_IDX (parm);
16125 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
16126 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, idx));
16128 /* Check for mixed types and values. */
16129 if ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
16130 && TREE_CODE (tparm) != TYPE_DECL)
16131 || (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
16132 && TREE_CODE (tparm) != TEMPLATE_DECL))
16133 gcc_unreachable ();
16135 if (TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
16137 /* ARG must be constructed from a template class or a template
16138 template parameter. */
16139 if (TREE_CODE (arg) != BOUND_TEMPLATE_TEMPLATE_PARM
16140 && !CLASSTYPE_SPECIALIZATION_OF_PRIMARY_TEMPLATE_P (arg))
16141 return unify_template_deduction_failure (explain_p, parm, arg);
16144 tree parmvec = TYPE_TI_ARGS (parm);
16145 tree argvec = INNERMOST_TEMPLATE_ARGS (TYPE_TI_ARGS (arg));
16146 tree full_argvec = add_to_template_args (targs, argvec);
16148 = DECL_INNERMOST_TEMPLATE_PARMS
16149 (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (parm));
16151 int parm_variadic_p = 0;
16153 /* The resolution to DR150 makes clear that default
16154 arguments for an N-argument may not be used to bind T
16155 to a template template parameter with fewer than N
16156 parameters. It is not safe to permit the binding of
16157 default arguments as an extension, as that may change
16158 the meaning of a conforming program. Consider:
16160 struct Dense { static const unsigned int dim = 1; };
16162 template <template <typename> class View,
16164 void operator+(float, View<Block> const&);
16166 template <typename Block,
16167 unsigned int Dim = Block::dim>
16168 struct Lvalue_proxy { operator float() const; };
16172 Lvalue_proxy<Dense> p;
16177 Here, if Lvalue_proxy is permitted to bind to View, then
16178 the global operator+ will be used; if they are not, the
16179 Lvalue_proxy will be converted to float. */
16180 if (coerce_template_parms (parm_parms,
16182 TYPE_TI_TEMPLATE (parm),
16184 ? tf_warning_or_error
16186 /*require_all_args=*/true,
16187 /*use_default_args=*/false)
16188 == error_mark_node)
16191 /* Deduce arguments T, i from TT<T> or TT<i>.
16192 We check each element of PARMVEC and ARGVEC individually
16193 rather than the whole TREE_VEC since they can have
16194 different number of elements. */
16196 parmvec = expand_template_argument_pack (parmvec);
16197 argvec = expand_template_argument_pack (argvec);
16199 len = TREE_VEC_LENGTH (parmvec);
16201 /* Check if the parameters end in a pack, making them
16204 && PACK_EXPANSION_P (TREE_VEC_ELT (parmvec, len - 1)))
16205 parm_variadic_p = 1;
16207 if (TREE_VEC_LENGTH (argvec) < len - parm_variadic_p)
16208 return unify_too_few_arguments (explain_p,
16209 TREE_VEC_LENGTH (argvec), len);
16211 for (i = 0; i < len - parm_variadic_p; ++i)
16213 RECUR_AND_CHECK_FAILURE (tparms, targs,
16214 TREE_VEC_ELT (parmvec, i),
16215 TREE_VEC_ELT (argvec, i),
16216 UNIFY_ALLOW_NONE, explain_p);
16219 if (parm_variadic_p
16220 && unify_pack_expansion (tparms, targs,
16223 /*subr=*/true, explain_p))
16226 arg = TYPE_TI_TEMPLATE (arg);
16228 /* Fall through to deduce template name. */
16231 if (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
16232 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
16234 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
16236 /* Simple cases: Value already set, does match or doesn't. */
16237 if (targ != NULL_TREE && template_args_equal (targ, arg))
16238 return unify_success (explain_p);
16240 return unify_inconsistency (explain_p, parm, targ, arg);
16244 /* If PARM is `const T' and ARG is only `int', we don't have
16245 a match unless we are allowing additional qualification.
16246 If ARG is `const int' and PARM is just `T' that's OK;
16247 that binds `const int' to `T'. */
16248 if (!check_cv_quals_for_unify (strict_in | UNIFY_ALLOW_LESS_CV_QUAL,
16250 return unify_cv_qual_mismatch (explain_p, parm, arg);
16252 /* Consider the case where ARG is `const volatile int' and
16253 PARM is `const T'. Then, T should be `volatile int'. */
16254 arg = cp_build_qualified_type_real
16255 (arg, cp_type_quals (arg) & ~cp_type_quals (parm), tf_none);
16256 if (arg == error_mark_node)
16257 return unify_invalid (explain_p);
16259 /* Simple cases: Value already set, does match or doesn't. */
16260 if (targ != NULL_TREE && same_type_p (targ, arg))
16261 return unify_success (explain_p);
16263 return unify_inconsistency (explain_p, parm, targ, arg);
16265 /* Make sure that ARG is not a variable-sized array. (Note
16266 that were talking about variable-sized arrays (like
16267 `int[n]'), rather than arrays of unknown size (like
16268 `int[]').) We'll get very confused by such a type since
16269 the bound of the array is not constant, and therefore
16270 not mangleable. Besides, such types are not allowed in
16271 ISO C++, so we can do as we please here. We do allow
16272 them for 'auto' deduction, since that isn't ABI-exposed. */
16273 if (!is_auto (parm) && variably_modified_type_p (arg, NULL_TREE))
16274 return unify_vla_arg (explain_p, arg);
16276 /* Strip typedefs as in convert_template_argument. */
16277 arg = canonicalize_type_argument (arg, tf_none);
16280 /* If ARG is a parameter pack or an expansion, we cannot unify
16281 against it unless PARM is also a parameter pack. */
16282 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
16283 && !template_parameter_pack_p (parm))
16284 return unify_parameter_pack_mismatch (explain_p, parm, arg);
16286 /* If the argument deduction results is a METHOD_TYPE,
16287 then there is a problem.
16288 METHOD_TYPE doesn't map to any real C++ type the result of
16289 the deduction can not be of that type. */
16290 if (TREE_CODE (arg) == METHOD_TYPE)
16291 return unify_method_type_error (explain_p, arg);
16293 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
16294 return unify_success (explain_p);
16296 case TEMPLATE_PARM_INDEX:
16297 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
16298 if (tparm == error_mark_node)
16299 return unify_invalid (explain_p);
16301 if (TEMPLATE_PARM_LEVEL (parm)
16302 != template_decl_level (tparm))
16304 /* The PARM is not one we're trying to unify. Just check
16305 to see if it matches ARG. */
16306 int result = !(TREE_CODE (arg) == TREE_CODE (parm)
16307 && cp_tree_equal (parm, arg));
16309 unify_expression_unequal (explain_p, parm, arg);
16313 idx = TEMPLATE_PARM_IDX (parm);
16314 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
16318 int x = !cp_tree_equal (targ, arg);
16320 unify_inconsistency (explain_p, parm, targ, arg);
16324 /* [temp.deduct.type] If, in the declaration of a function template
16325 with a non-type template-parameter, the non-type
16326 template-parameter is used in an expression in the function
16327 parameter-list and, if the corresponding template-argument is
16328 deduced, the template-argument type shall match the type of the
16329 template-parameter exactly, except that a template-argument
16330 deduced from an array bound may be of any integral type.
16331 The non-type parameter might use already deduced type parameters. */
16332 tparm = tsubst (TREE_TYPE (parm), targs, 0, NULL_TREE);
16333 if (!TREE_TYPE (arg))
16334 /* Template-parameter dependent expression. Just accept it for now.
16335 It will later be processed in convert_template_argument. */
16337 else if (same_type_p (TREE_TYPE (arg), tparm))
16339 else if ((strict & UNIFY_ALLOW_INTEGER)
16340 && (TREE_CODE (tparm) == INTEGER_TYPE
16341 || TREE_CODE (tparm) == BOOLEAN_TYPE))
16342 /* Convert the ARG to the type of PARM; the deduced non-type
16343 template argument must exactly match the types of the
16344 corresponding parameter. */
16345 arg = fold (build_nop (tparm, arg));
16346 else if (uses_template_parms (tparm))
16347 /* We haven't deduced the type of this parameter yet. Try again
16349 return unify_success (explain_p);
16351 return unify_type_mismatch (explain_p, tparm, arg);
16353 /* If ARG is a parameter pack or an expansion, we cannot unify
16354 against it unless PARM is also a parameter pack. */
16355 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
16356 && !TEMPLATE_PARM_PARAMETER_PACK (parm))
16357 return unify_parameter_pack_mismatch (explain_p, parm, arg);
16359 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
16360 return unify_success (explain_p);
16364 /* A pointer-to-member constant can be unified only with
16365 another constant. */
16366 if (TREE_CODE (arg) != PTRMEM_CST)
16367 return unify_ptrmem_cst_mismatch (explain_p, parm, arg);
16369 /* Just unify the class member. It would be useless (and possibly
16370 wrong, depending on the strict flags) to unify also
16371 PTRMEM_CST_CLASS, because we want to be sure that both parm and
16372 arg refer to the same variable, even if through different
16373 classes. For instance:
16375 struct A { int x; };
16378 Unification of &A::x and &B::x must succeed. */
16379 return unify (tparms, targs, PTRMEM_CST_MEMBER (parm),
16380 PTRMEM_CST_MEMBER (arg), strict, explain_p);
16385 if (TREE_CODE (arg) != POINTER_TYPE)
16386 return unify_type_mismatch (explain_p, parm, arg);
16388 /* [temp.deduct.call]
16390 A can be another pointer or pointer to member type that can
16391 be converted to the deduced A via a qualification
16392 conversion (_conv.qual_).
16394 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
16395 This will allow for additional cv-qualification of the
16396 pointed-to types if appropriate. */
16398 if (TREE_CODE (TREE_TYPE (arg)) == RECORD_TYPE)
16399 /* The derived-to-base conversion only persists through one
16400 level of pointers. */
16401 strict |= (strict_in & UNIFY_ALLOW_DERIVED);
16403 return unify (tparms, targs, TREE_TYPE (parm),
16404 TREE_TYPE (arg), strict, explain_p);
16407 case REFERENCE_TYPE:
16408 if (TREE_CODE (arg) != REFERENCE_TYPE)
16409 return unify_type_mismatch (explain_p, parm, arg);
16410 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
16411 strict & UNIFY_ALLOW_MORE_CV_QUAL, explain_p);
16414 if (TREE_CODE (arg) != ARRAY_TYPE)
16415 return unify_type_mismatch (explain_p, parm, arg);
16416 if ((TYPE_DOMAIN (parm) == NULL_TREE)
16417 != (TYPE_DOMAIN (arg) == NULL_TREE))
16418 return unify_type_mismatch (explain_p, parm, arg);
16419 if (TYPE_DOMAIN (parm) != NULL_TREE)
16426 /* Our representation of array types uses "N - 1" as the
16427 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
16428 not an integer constant. We cannot unify arbitrarily
16429 complex expressions, so we eliminate the MINUS_EXPRs
16431 parm_max = TYPE_MAX_VALUE (TYPE_DOMAIN (parm));
16432 parm_cst = TREE_CODE (parm_max) == INTEGER_CST;
16435 gcc_assert (TREE_CODE (parm_max) == MINUS_EXPR);
16436 parm_max = TREE_OPERAND (parm_max, 0);
16438 arg_max = TYPE_MAX_VALUE (TYPE_DOMAIN (arg));
16439 arg_cst = TREE_CODE (arg_max) == INTEGER_CST;
16442 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
16443 trying to unify the type of a variable with the type
16444 of a template parameter. For example:
16446 template <unsigned int N>
16447 void f (char (&) [N]);
16454 Here, the type of the ARG will be "int [g(i)]", and
16455 may be a SAVE_EXPR, etc. */
16456 if (TREE_CODE (arg_max) != MINUS_EXPR)
16457 return unify_vla_arg (explain_p, arg);
16458 arg_max = TREE_OPERAND (arg_max, 0);
16461 /* If only one of the bounds used a MINUS_EXPR, compensate
16462 by adding one to the other bound. */
16463 if (parm_cst && !arg_cst)
16464 parm_max = fold_build2_loc (input_location, PLUS_EXPR,
16468 else if (arg_cst && !parm_cst)
16469 arg_max = fold_build2_loc (input_location, PLUS_EXPR,
16474 RECUR_AND_CHECK_FAILURE (tparms, targs, parm_max, arg_max,
16475 UNIFY_ALLOW_INTEGER, explain_p);
16477 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
16478 strict & UNIFY_ALLOW_MORE_CV_QUAL, explain_p);
16485 case ENUMERAL_TYPE:
16487 if (TREE_CODE (arg) != TREE_CODE (parm))
16488 return unify_type_mismatch (explain_p, parm, arg);
16490 /* We have already checked cv-qualification at the top of the
16492 if (!same_type_ignoring_top_level_qualifiers_p (arg, parm))
16493 return unify_type_mismatch (explain_p, parm, arg);
16495 /* As far as unification is concerned, this wins. Later checks
16496 will invalidate it if necessary. */
16497 return unify_success (explain_p);
16499 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
16500 /* Type INTEGER_CST can come from ordinary constant template args. */
16502 while (TREE_CODE (arg) == NOP_EXPR)
16503 arg = TREE_OPERAND (arg, 0);
16505 if (TREE_CODE (arg) != INTEGER_CST)
16506 return unify_template_argument_mismatch (explain_p, parm, arg);
16507 return (tree_int_cst_equal (parm, arg)
16508 ? unify_success (explain_p)
16509 : unify_template_argument_mismatch (explain_p, parm, arg));
16513 int i, len, argslen;
16514 int parm_variadic_p = 0;
16516 if (TREE_CODE (arg) != TREE_VEC)
16517 return unify_template_argument_mismatch (explain_p, parm, arg);
16519 len = TREE_VEC_LENGTH (parm);
16520 argslen = TREE_VEC_LENGTH (arg);
16522 /* Check for pack expansions in the parameters. */
16523 for (i = 0; i < len; ++i)
16525 if (PACK_EXPANSION_P (TREE_VEC_ELT (parm, i)))
16528 /* We can unify against something with a trailing
16530 parm_variadic_p = 1;
16532 /* [temp.deduct.type]/9: If the template argument list of
16533 P contains a pack expansion that is not the last
16534 template argument, the entire template argument list
16535 is a non-deduced context. */
16536 return unify_success (explain_p);
16540 /* If we don't have enough arguments to satisfy the parameters
16541 (not counting the pack expression at the end), or we have
16542 too many arguments for a parameter list that doesn't end in
16543 a pack expression, we can't unify. */
16544 if (parm_variadic_p
16545 ? argslen < len - parm_variadic_p
16547 return unify_arity (explain_p, TREE_VEC_LENGTH (arg), len);
16549 /* Unify all of the parameters that precede the (optional)
16550 pack expression. */
16551 for (i = 0; i < len - parm_variadic_p; ++i)
16553 RECUR_AND_CHECK_FAILURE (tparms, targs,
16554 TREE_VEC_ELT (parm, i),
16555 TREE_VEC_ELT (arg, i),
16556 UNIFY_ALLOW_NONE, explain_p);
16558 if (parm_variadic_p)
16559 return unify_pack_expansion (tparms, targs, parm, arg,
16561 /*subr=*/true, explain_p);
16562 return unify_success (explain_p);
16567 if (TREE_CODE (arg) != TREE_CODE (parm))
16568 return unify_type_mismatch (explain_p, parm, arg);
16570 if (TYPE_PTRMEMFUNC_P (parm))
16572 if (!TYPE_PTRMEMFUNC_P (arg))
16573 return unify_type_mismatch (explain_p, parm, arg);
16575 return unify (tparms, targs,
16576 TYPE_PTRMEMFUNC_FN_TYPE (parm),
16577 TYPE_PTRMEMFUNC_FN_TYPE (arg),
16578 strict, explain_p);
16581 if (CLASSTYPE_TEMPLATE_INFO (parm))
16583 tree t = NULL_TREE;
16585 if (strict_in & UNIFY_ALLOW_DERIVED)
16587 /* First, we try to unify the PARM and ARG directly. */
16588 t = try_class_unification (tparms, targs,
16589 parm, arg, explain_p);
16593 /* Fallback to the special case allowed in
16594 [temp.deduct.call]:
16596 If P is a class, and P has the form
16597 template-id, then A can be a derived class of
16598 the deduced A. Likewise, if P is a pointer to
16599 a class of the form template-id, A can be a
16600 pointer to a derived class pointed to by the
16602 enum template_base_result r;
16603 r = get_template_base (tparms, targs, parm, arg,
16607 return unify_no_common_base (explain_p, r, parm, arg);
16610 else if (CLASSTYPE_TEMPLATE_INFO (arg)
16611 && (CLASSTYPE_TI_TEMPLATE (parm)
16612 == CLASSTYPE_TI_TEMPLATE (arg)))
16613 /* Perhaps PARM is something like S<U> and ARG is S<int>.
16614 Then, we should unify `int' and `U'. */
16617 /* There's no chance of unification succeeding. */
16618 return unify_type_mismatch (explain_p, parm, arg);
16620 return unify (tparms, targs, CLASSTYPE_TI_ARGS (parm),
16621 CLASSTYPE_TI_ARGS (t), UNIFY_ALLOW_NONE, explain_p);
16623 else if (!same_type_ignoring_top_level_qualifiers_p (parm, arg))
16624 return unify_type_mismatch (explain_p, parm, arg);
16625 return unify_success (explain_p);
16628 case FUNCTION_TYPE:
16630 unsigned int nargs;
16635 if (TREE_CODE (arg) != TREE_CODE (parm))
16636 return unify_type_mismatch (explain_p, parm, arg);
16638 /* CV qualifications for methods can never be deduced, they must
16639 match exactly. We need to check them explicitly here,
16640 because type_unification_real treats them as any other
16641 cv-qualified parameter. */
16642 if (TREE_CODE (parm) == METHOD_TYPE
16643 && (!check_cv_quals_for_unify
16645 class_of_this_parm (arg),
16646 class_of_this_parm (parm))))
16647 return unify_cv_qual_mismatch (explain_p, parm, arg);
16649 RECUR_AND_CHECK_FAILURE (tparms, targs, TREE_TYPE (parm),
16650 TREE_TYPE (arg), UNIFY_ALLOW_NONE, explain_p);
16652 nargs = list_length (TYPE_ARG_TYPES (arg));
16653 args = XALLOCAVEC (tree, nargs);
16654 for (a = TYPE_ARG_TYPES (arg), i = 0;
16655 a != NULL_TREE && a != void_list_node;
16656 a = TREE_CHAIN (a), ++i)
16657 args[i] = TREE_VALUE (a);
16660 return type_unification_real (tparms, targs, TYPE_ARG_TYPES (parm),
16661 args, nargs, 1, DEDUCE_EXACT,
16662 LOOKUP_NORMAL, explain_p);
16666 /* Unify a pointer to member with a pointer to member function, which
16667 deduces the type of the member as a function type. */
16668 if (TYPE_PTRMEMFUNC_P (arg))
16673 /* Check top-level cv qualifiers */
16674 if (!check_cv_quals_for_unify (UNIFY_ALLOW_NONE, arg, parm))
16675 return unify_cv_qual_mismatch (explain_p, parm, arg);
16677 RECUR_AND_CHECK_FAILURE (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
16678 TYPE_PTRMEMFUNC_OBJECT_TYPE (arg),
16679 UNIFY_ALLOW_NONE, explain_p);
16681 /* Determine the type of the function we are unifying against. */
16682 method_type = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (arg));
16684 build_function_type (TREE_TYPE (method_type),
16685 TREE_CHAIN (TYPE_ARG_TYPES (method_type)));
16687 /* Extract the cv-qualifiers of the member function from the
16688 implicit object parameter and place them on the function
16689 type to be restored later. */
16690 fntype = apply_memfn_quals (fntype, type_memfn_quals (method_type));
16691 return unify (tparms, targs, TREE_TYPE (parm), fntype, strict, explain_p);
16694 if (TREE_CODE (arg) != OFFSET_TYPE)
16695 return unify_type_mismatch (explain_p, parm, arg);
16696 RECUR_AND_CHECK_FAILURE (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
16697 TYPE_OFFSET_BASETYPE (arg),
16698 UNIFY_ALLOW_NONE, explain_p);
16699 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
16700 strict, explain_p);
16703 if (DECL_TEMPLATE_PARM_P (parm))
16704 return unify (tparms, targs, DECL_INITIAL (parm), arg, strict, explain_p);
16705 if (arg != integral_constant_value (parm))
16706 return unify_template_argument_mismatch (explain_p, parm, arg);
16707 return unify_success (explain_p);
16710 case TEMPLATE_DECL:
16711 /* Matched cases are handled by the ARG == PARM test above. */
16712 return unify_template_argument_mismatch (explain_p, parm, arg);
16715 /* A non-type template parameter that is a variable should be a
16716 an integral constant, in which case, it whould have been
16717 folded into its (constant) value. So we should not be getting
16718 a variable here. */
16719 gcc_unreachable ();
16721 case TYPE_ARGUMENT_PACK:
16722 case NONTYPE_ARGUMENT_PACK:
16723 return unify (tparms, targs, ARGUMENT_PACK_ARGS (parm),
16724 ARGUMENT_PACK_ARGS (arg), strict, explain_p);
16727 case DECLTYPE_TYPE:
16728 case UNDERLYING_TYPE:
16729 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
16730 or UNDERLYING_TYPE nodes. */
16731 return unify_success (explain_p);
16734 /* Unification fails if we hit an error node. */
16735 return unify_invalid (explain_p);
16738 /* An unresolved overload is a nondeduced context. */
16739 if (type_unknown_p (parm))
16740 return unify_success (explain_p);
16741 gcc_assert (EXPR_P (parm));
16743 /* We must be looking at an expression. This can happen with
16747 void foo(S<I>, S<I + 2>);
16749 This is a "nondeduced context":
16753 The nondeduced contexts are:
16755 --A type that is a template-id in which one or more of
16756 the template-arguments is an expression that references
16757 a template-parameter.
16759 In these cases, we assume deduction succeeded, but don't
16760 actually infer any unifications. */
16762 if (!uses_template_parms (parm)
16763 && !template_args_equal (parm, arg))
16764 return unify_expression_unequal (explain_p, parm, arg);
16766 return unify_success (explain_p);
16769 #undef RECUR_AND_CHECK_FAILURE
16771 /* Note that DECL can be defined in this translation unit, if
16775 mark_definable (tree decl)
16778 DECL_NOT_REALLY_EXTERN (decl) = 1;
16779 FOR_EACH_CLONE (clone, decl)
16780 DECL_NOT_REALLY_EXTERN (clone) = 1;
16783 /* Called if RESULT is explicitly instantiated, or is a member of an
16784 explicitly instantiated class. */
16787 mark_decl_instantiated (tree result, int extern_p)
16789 SET_DECL_EXPLICIT_INSTANTIATION (result);
16791 /* If this entity has already been written out, it's too late to
16792 make any modifications. */
16793 if (TREE_ASM_WRITTEN (result))
16796 if (TREE_CODE (result) != FUNCTION_DECL)
16797 /* The TREE_PUBLIC flag for function declarations will have been
16798 set correctly by tsubst. */
16799 TREE_PUBLIC (result) = 1;
16801 /* This might have been set by an earlier implicit instantiation. */
16802 DECL_COMDAT (result) = 0;
16805 DECL_NOT_REALLY_EXTERN (result) = 0;
16808 mark_definable (result);
16809 /* Always make artificials weak. */
16810 if (DECL_ARTIFICIAL (result) && flag_weak)
16811 comdat_linkage (result);
16812 /* For WIN32 we also want to put explicit instantiations in
16813 linkonce sections. */
16814 else if (TREE_PUBLIC (result))
16815 maybe_make_one_only (result);
16818 /* If EXTERN_P, then this function will not be emitted -- unless
16819 followed by an explicit instantiation, at which point its linkage
16820 will be adjusted. If !EXTERN_P, then this function will be
16821 emitted here. In neither circumstance do we want
16822 import_export_decl to adjust the linkage. */
16823 DECL_INTERFACE_KNOWN (result) = 1;
16826 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
16827 important template arguments. If any are missing, we check whether
16828 they're important by using error_mark_node for substituting into any
16829 args that were used for partial ordering (the ones between ARGS and END)
16830 and seeing if it bubbles up. */
16833 check_undeduced_parms (tree targs, tree args, tree end)
16835 bool found = false;
16837 for (i = TREE_VEC_LENGTH (targs) - 1; i >= 0; --i)
16838 if (TREE_VEC_ELT (targs, i) == NULL_TREE)
16841 TREE_VEC_ELT (targs, i) = error_mark_node;
16845 for (; args != end; args = TREE_CHAIN (args))
16847 tree substed = tsubst (TREE_VALUE (args), targs, tf_none, NULL_TREE);
16848 if (substed == error_mark_node)
16855 /* Given two function templates PAT1 and PAT2, return:
16857 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
16858 -1 if PAT2 is more specialized than PAT1.
16859 0 if neither is more specialized.
16861 LEN indicates the number of parameters we should consider
16862 (defaulted parameters should not be considered).
16864 The 1998 std underspecified function template partial ordering, and
16865 DR214 addresses the issue. We take pairs of arguments, one from
16866 each of the templates, and deduce them against each other. One of
16867 the templates will be more specialized if all the *other*
16868 template's arguments deduce against its arguments and at least one
16869 of its arguments *does* *not* deduce against the other template's
16870 corresponding argument. Deduction is done as for class templates.
16871 The arguments used in deduction have reference and top level cv
16872 qualifiers removed. Iff both arguments were originally reference
16873 types *and* deduction succeeds in both directions, the template
16874 with the more cv-qualified argument wins for that pairing (if
16875 neither is more cv-qualified, they both are equal). Unlike regular
16876 deduction, after all the arguments have been deduced in this way,
16877 we do *not* verify the deduced template argument values can be
16878 substituted into non-deduced contexts.
16880 The logic can be a bit confusing here, because we look at deduce1 and
16881 targs1 to see if pat2 is at least as specialized, and vice versa; if we
16882 can find template arguments for pat1 to make arg1 look like arg2, that
16883 means that arg2 is at least as specialized as arg1. */
16886 more_specialized_fn (tree pat1, tree pat2, int len)
16888 tree decl1 = DECL_TEMPLATE_RESULT (pat1);
16889 tree decl2 = DECL_TEMPLATE_RESULT (pat2);
16890 tree targs1 = make_tree_vec (DECL_NTPARMS (pat1));
16891 tree targs2 = make_tree_vec (DECL_NTPARMS (pat2));
16892 tree tparms1 = DECL_INNERMOST_TEMPLATE_PARMS (pat1);
16893 tree tparms2 = DECL_INNERMOST_TEMPLATE_PARMS (pat2);
16894 tree args1 = TYPE_ARG_TYPES (TREE_TYPE (decl1));
16895 tree args2 = TYPE_ARG_TYPES (TREE_TYPE (decl2));
16896 tree origs1, origs2;
16897 bool lose1 = false;
16898 bool lose2 = false;
16900 /* Remove the this parameter from non-static member functions. If
16901 one is a non-static member function and the other is not a static
16902 member function, remove the first parameter from that function
16903 also. This situation occurs for operator functions where we
16904 locate both a member function (with this pointer) and non-member
16905 operator (with explicit first operand). */
16906 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl1))
16908 len--; /* LEN is the number of significant arguments for DECL1 */
16909 args1 = TREE_CHAIN (args1);
16910 if (!DECL_STATIC_FUNCTION_P (decl2))
16911 args2 = TREE_CHAIN (args2);
16913 else if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl2))
16915 args2 = TREE_CHAIN (args2);
16916 if (!DECL_STATIC_FUNCTION_P (decl1))
16919 args1 = TREE_CHAIN (args1);
16923 /* If only one is a conversion operator, they are unordered. */
16924 if (DECL_CONV_FN_P (decl1) != DECL_CONV_FN_P (decl2))
16927 /* Consider the return type for a conversion function */
16928 if (DECL_CONV_FN_P (decl1))
16930 args1 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl1)), args1);
16931 args2 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl2)), args2);
16935 processing_template_decl++;
16941 /* Stop when an ellipsis is seen. */
16942 && args1 != NULL_TREE && args2 != NULL_TREE)
16944 tree arg1 = TREE_VALUE (args1);
16945 tree arg2 = TREE_VALUE (args2);
16946 int deduce1, deduce2;
16950 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
16951 && TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
16953 /* When both arguments are pack expansions, we need only
16954 unify the patterns themselves. */
16955 arg1 = PACK_EXPANSION_PATTERN (arg1);
16956 arg2 = PACK_EXPANSION_PATTERN (arg2);
16958 /* This is the last comparison we need to do. */
16962 if (TREE_CODE (arg1) == REFERENCE_TYPE)
16964 arg1 = TREE_TYPE (arg1);
16965 quals1 = cp_type_quals (arg1);
16968 if (TREE_CODE (arg2) == REFERENCE_TYPE)
16970 arg2 = TREE_TYPE (arg2);
16971 quals2 = cp_type_quals (arg2);
16974 if ((quals1 < 0) != (quals2 < 0))
16976 /* Only of the args is a reference, see if we should apply
16977 array/function pointer decay to it. This is not part of
16978 DR214, but is, IMHO, consistent with the deduction rules
16979 for the function call itself, and with our earlier
16980 implementation of the underspecified partial ordering
16981 rules. (nathan). */
16984 switch (TREE_CODE (arg1))
16987 arg1 = TREE_TYPE (arg1);
16989 case FUNCTION_TYPE:
16990 arg1 = build_pointer_type (arg1);
16999 switch (TREE_CODE (arg2))
17002 arg2 = TREE_TYPE (arg2);
17004 case FUNCTION_TYPE:
17005 arg2 = build_pointer_type (arg2);
17014 arg1 = TYPE_MAIN_VARIANT (arg1);
17015 arg2 = TYPE_MAIN_VARIANT (arg2);
17017 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION)
17019 int i, len2 = list_length (args2);
17020 tree parmvec = make_tree_vec (1);
17021 tree argvec = make_tree_vec (len2);
17024 /* Setup the parameter vector, which contains only ARG1. */
17025 TREE_VEC_ELT (parmvec, 0) = arg1;
17027 /* Setup the argument vector, which contains the remaining
17029 for (i = 0; i < len2; i++, ta = TREE_CHAIN (ta))
17030 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
17032 deduce1 = (unify_pack_expansion (tparms1, targs1, parmvec,
17033 argvec, DEDUCE_EXACT,
17034 /*subr=*/true, /*explain_p=*/false)
17037 /* We cannot deduce in the other direction, because ARG1 is
17038 a pack expansion but ARG2 is not. */
17041 else if (TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
17043 int i, len1 = list_length (args1);
17044 tree parmvec = make_tree_vec (1);
17045 tree argvec = make_tree_vec (len1);
17048 /* Setup the parameter vector, which contains only ARG1. */
17049 TREE_VEC_ELT (parmvec, 0) = arg2;
17051 /* Setup the argument vector, which contains the remaining
17053 for (i = 0; i < len1; i++, ta = TREE_CHAIN (ta))
17054 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
17056 deduce2 = (unify_pack_expansion (tparms2, targs2, parmvec,
17057 argvec, DEDUCE_EXACT,
17058 /*subr=*/true, /*explain_p=*/false)
17061 /* We cannot deduce in the other direction, because ARG2 is
17062 a pack expansion but ARG1 is not.*/
17068 /* The normal case, where neither argument is a pack
17070 deduce1 = (unify (tparms1, targs1, arg1, arg2,
17071 UNIFY_ALLOW_NONE, /*explain_p=*/false)
17073 deduce2 = (unify (tparms2, targs2, arg2, arg1,
17074 UNIFY_ALLOW_NONE, /*explain_p=*/false)
17078 /* If we couldn't deduce arguments for tparms1 to make arg1 match
17079 arg2, then arg2 is not as specialized as arg1. */
17085 /* "If, for a given type, deduction succeeds in both directions
17086 (i.e., the types are identical after the transformations above)
17087 and if the type from the argument template is more cv-qualified
17088 than the type from the parameter template (as described above)
17089 that type is considered to be more specialized than the other. If
17090 neither type is more cv-qualified than the other then neither type
17091 is more specialized than the other." */
17093 if (deduce1 && deduce2
17094 && quals1 != quals2 && quals1 >= 0 && quals2 >= 0)
17096 if ((quals1 & quals2) == quals2)
17098 if ((quals1 & quals2) == quals1)
17102 if (lose1 && lose2)
17103 /* We've failed to deduce something in either direction.
17104 These must be unordered. */
17107 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
17108 || TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
17109 /* We have already processed all of the arguments in our
17110 handing of the pack expansion type. */
17113 args1 = TREE_CHAIN (args1);
17114 args2 = TREE_CHAIN (args2);
17117 /* "In most cases, all template parameters must have values in order for
17118 deduction to succeed, but for partial ordering purposes a template
17119 parameter may remain without a value provided it is not used in the
17120 types being used for partial ordering."
17122 Thus, if we are missing any of the targs1 we need to substitute into
17123 origs1, then pat2 is not as specialized as pat1. This can happen when
17124 there is a nondeduced context. */
17125 if (!lose2 && check_undeduced_parms (targs1, origs1, args1))
17127 if (!lose1 && check_undeduced_parms (targs2, origs2, args2))
17130 processing_template_decl--;
17132 /* All things being equal, if the next argument is a pack expansion
17133 for one function but not for the other, prefer the
17134 non-variadic function. FIXME this is bogus; see c++/41958. */
17136 && args1 && TREE_VALUE (args1)
17137 && args2 && TREE_VALUE (args2))
17139 lose1 = TREE_CODE (TREE_VALUE (args1)) == TYPE_PACK_EXPANSION;
17140 lose2 = TREE_CODE (TREE_VALUE (args2)) == TYPE_PACK_EXPANSION;
17143 if (lose1 == lose2)
17151 /* Determine which of two partial specializations is more specialized.
17153 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
17154 to the first partial specialization. The TREE_VALUE is the
17155 innermost set of template parameters for the partial
17156 specialization. PAT2 is similar, but for the second template.
17158 Return 1 if the first partial specialization is more specialized;
17159 -1 if the second is more specialized; 0 if neither is more
17162 See [temp.class.order] for information about determining which of
17163 two templates is more specialized. */
17166 more_specialized_class (tree pat1, tree pat2)
17171 bool any_deductions = false;
17173 tmpl1 = TREE_TYPE (pat1);
17174 tmpl2 = TREE_TYPE (pat2);
17176 /* Just like what happens for functions, if we are ordering between
17177 different class template specializations, we may encounter dependent
17178 types in the arguments, and we need our dependency check functions
17179 to behave correctly. */
17180 ++processing_template_decl;
17181 targs = get_class_bindings (TREE_VALUE (pat1),
17182 CLASSTYPE_TI_ARGS (tmpl1),
17183 CLASSTYPE_TI_ARGS (tmpl2));
17187 any_deductions = true;
17190 targs = get_class_bindings (TREE_VALUE (pat2),
17191 CLASSTYPE_TI_ARGS (tmpl2),
17192 CLASSTYPE_TI_ARGS (tmpl1));
17196 any_deductions = true;
17198 --processing_template_decl;
17200 /* In the case of a tie where at least one of the class templates
17201 has a parameter pack at the end, the template with the most
17202 non-packed parameters wins. */
17205 && (template_args_variadic_p (TREE_PURPOSE (pat1))
17206 || template_args_variadic_p (TREE_PURPOSE (pat2))))
17208 tree args1 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat1));
17209 tree args2 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat2));
17210 int len1 = TREE_VEC_LENGTH (args1);
17211 int len2 = TREE_VEC_LENGTH (args2);
17213 /* We don't count the pack expansion at the end. */
17214 if (template_args_variadic_p (TREE_PURPOSE (pat1)))
17216 if (template_args_variadic_p (TREE_PURPOSE (pat2)))
17221 else if (len1 < len2)
17228 /* Return the template arguments that will produce the function signature
17229 DECL from the function template FN, with the explicit template
17230 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
17231 also match. Return NULL_TREE if no satisfactory arguments could be
17235 get_bindings (tree fn, tree decl, tree explicit_args, bool check_rettype)
17237 int ntparms = DECL_NTPARMS (fn);
17238 tree targs = make_tree_vec (ntparms);
17240 tree decl_arg_types;
17242 unsigned int nargs, ix;
17245 /* Substitute the explicit template arguments into the type of DECL.
17246 The call to fn_type_unification will handle substitution into the
17248 decl_type = TREE_TYPE (decl);
17249 if (explicit_args && uses_template_parms (decl_type))
17252 tree converted_args;
17254 if (DECL_TEMPLATE_INFO (decl))
17255 tmpl = DECL_TI_TEMPLATE (decl);
17257 /* We can get here for some invalid specializations. */
17261 = coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
17262 explicit_args, NULL_TREE,
17264 /*require_all_args=*/false,
17265 /*use_default_args=*/false);
17266 if (converted_args == error_mark_node)
17269 decl_type = tsubst (decl_type, converted_args, tf_none, NULL_TREE);
17270 if (decl_type == error_mark_node)
17274 /* Never do unification on the 'this' parameter. */
17275 decl_arg_types = skip_artificial_parms_for (decl,
17276 TYPE_ARG_TYPES (decl_type));
17278 nargs = list_length (decl_arg_types);
17279 args = XALLOCAVEC (tree, nargs);
17280 for (arg = decl_arg_types, ix = 0;
17281 arg != NULL_TREE && arg != void_list_node;
17282 arg = TREE_CHAIN (arg), ++ix)
17283 args[ix] = TREE_VALUE (arg);
17285 if (fn_type_unification (fn, explicit_args, targs,
17287 (check_rettype || DECL_CONV_FN_P (fn)
17288 ? TREE_TYPE (decl_type) : NULL_TREE),
17289 DEDUCE_EXACT, LOOKUP_NORMAL, /*explain_p=*/false))
17295 /* Return the innermost template arguments that, when applied to a
17296 template specialization whose innermost template parameters are
17297 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
17300 For example, suppose we have:
17302 template <class T, class U> struct S {};
17303 template <class T> struct S<T*, int> {};
17305 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
17306 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
17307 int}. The resulting vector will be {double}, indicating that `T'
17308 is bound to `double'. */
17311 get_class_bindings (tree tparms, tree spec_args, tree args)
17313 int i, ntparms = TREE_VEC_LENGTH (tparms);
17315 tree innermost_deduced_args;
17317 innermost_deduced_args = make_tree_vec (ntparms);
17318 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
17320 deduced_args = copy_node (args);
17321 SET_TMPL_ARGS_LEVEL (deduced_args,
17322 TMPL_ARGS_DEPTH (deduced_args),
17323 innermost_deduced_args);
17326 deduced_args = innermost_deduced_args;
17328 if (unify (tparms, deduced_args,
17329 INNERMOST_TEMPLATE_ARGS (spec_args),
17330 INNERMOST_TEMPLATE_ARGS (args),
17331 UNIFY_ALLOW_NONE, /*explain_p=*/false))
17334 for (i = 0; i < ntparms; ++i)
17335 if (! TREE_VEC_ELT (innermost_deduced_args, i))
17338 /* Verify that nondeduced template arguments agree with the type
17339 obtained from argument deduction.
17343 struct A { typedef int X; };
17344 template <class T, class U> struct C {};
17345 template <class T> struct C<T, typename T::X> {};
17347 Then with the instantiation `C<A, int>', we can deduce that
17348 `T' is `A' but unify () does not check whether `typename T::X'
17350 spec_args = tsubst (spec_args, deduced_args, tf_none, NULL_TREE);
17351 if (spec_args == error_mark_node
17352 /* We only need to check the innermost arguments; the other
17353 arguments will always agree. */
17354 || !comp_template_args (INNERMOST_TEMPLATE_ARGS (spec_args),
17355 INNERMOST_TEMPLATE_ARGS (args)))
17358 /* Now that we have bindings for all of the template arguments,
17359 ensure that the arguments deduced for the template template
17360 parameters have compatible template parameter lists. See the use
17361 of template_template_parm_bindings_ok_p in fn_type_unification
17362 for more information. */
17363 if (!template_template_parm_bindings_ok_p (tparms, deduced_args))
17366 return deduced_args;
17369 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
17370 Return the TREE_LIST node with the most specialized template, if
17371 any. If there is no most specialized template, the error_mark_node
17374 Note that this function does not look at, or modify, the
17375 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
17376 returned is one of the elements of INSTANTIATIONS, callers may
17377 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
17378 and retrieve it from the value returned. */
17381 most_specialized_instantiation (tree templates)
17385 ++processing_template_decl;
17388 for (fn = TREE_CHAIN (templates); fn; fn = TREE_CHAIN (fn))
17392 if (get_bindings (TREE_VALUE (champ),
17393 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
17394 NULL_TREE, /*check_ret=*/true))
17397 if (get_bindings (TREE_VALUE (fn),
17398 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
17399 NULL_TREE, /*check_ret=*/true))
17406 /* Equally specialized, move to next function. If there
17407 is no next function, nothing's most specialized. */
17408 fn = TREE_CHAIN (fn);
17416 /* Now verify that champ is better than everything earlier in the
17417 instantiation list. */
17418 for (fn = templates; fn != champ; fn = TREE_CHAIN (fn))
17419 if (get_bindings (TREE_VALUE (champ),
17420 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
17421 NULL_TREE, /*check_ret=*/true)
17422 || !get_bindings (TREE_VALUE (fn),
17423 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
17424 NULL_TREE, /*check_ret=*/true))
17430 processing_template_decl--;
17433 return error_mark_node;
17438 /* If DECL is a specialization of some template, return the most
17439 general such template. Otherwise, returns NULL_TREE.
17441 For example, given:
17443 template <class T> struct S { template <class U> void f(U); };
17445 if TMPL is `template <class U> void S<int>::f(U)' this will return
17446 the full template. This function will not trace past partial
17447 specializations, however. For example, given in addition:
17449 template <class T> struct S<T*> { template <class U> void f(U); };
17451 if TMPL is `template <class U> void S<int*>::f(U)' this will return
17452 `template <class T> template <class U> S<T*>::f(U)'. */
17455 most_general_template (tree decl)
17457 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
17458 an immediate specialization. */
17459 if (TREE_CODE (decl) == FUNCTION_DECL)
17461 if (DECL_TEMPLATE_INFO (decl)) {
17462 decl = DECL_TI_TEMPLATE (decl);
17464 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
17465 template friend. */
17466 if (TREE_CODE (decl) != TEMPLATE_DECL)
17472 /* Look for more and more general templates. */
17473 while (DECL_TEMPLATE_INFO (decl))
17475 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
17476 (See cp-tree.h for details.) */
17477 if (TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
17480 if (CLASS_TYPE_P (TREE_TYPE (decl))
17481 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)))
17484 /* Stop if we run into an explicitly specialized class template. */
17485 if (!DECL_NAMESPACE_SCOPE_P (decl)
17486 && DECL_CONTEXT (decl)
17487 && CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (decl)))
17490 decl = DECL_TI_TEMPLATE (decl);
17496 /* Return the most specialized of the class template partial
17497 specializations of TMPL which can produce TYPE, a specialization of
17498 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
17499 a _TYPE node corresponding to the partial specialization, while the
17500 TREE_PURPOSE is the set of template arguments that must be
17501 substituted into the TREE_TYPE in order to generate TYPE.
17503 If the choice of partial specialization is ambiguous, a diagnostic
17504 is issued, and the error_mark_node is returned. If there are no
17505 partial specializations of TMPL matching TYPE, then NULL_TREE is
17509 most_specialized_class (tree type, tree tmpl, tsubst_flags_t complain)
17511 tree list = NULL_TREE;
17517 tree outer_args = NULL_TREE;
17519 tmpl = most_general_template (tmpl);
17520 args = CLASSTYPE_TI_ARGS (type);
17522 /* For determining which partial specialization to use, only the
17523 innermost args are interesting. */
17524 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
17526 outer_args = strip_innermost_template_args (args, 1);
17527 args = INNERMOST_TEMPLATE_ARGS (args);
17530 for (t = DECL_TEMPLATE_SPECIALIZATIONS (tmpl); t; t = TREE_CHAIN (t))
17532 tree partial_spec_args;
17534 tree parms = TREE_VALUE (t);
17536 partial_spec_args = CLASSTYPE_TI_ARGS (TREE_TYPE (t));
17538 ++processing_template_decl;
17544 /* Discard the outer levels of args, and then substitute in the
17545 template args from the enclosing class. */
17546 partial_spec_args = INNERMOST_TEMPLATE_ARGS (partial_spec_args);
17547 partial_spec_args = tsubst_template_args
17548 (partial_spec_args, outer_args, tf_none, NULL_TREE);
17550 /* PARMS already refers to just the innermost parms, but the
17551 template parms in partial_spec_args had their levels lowered
17552 by tsubst, so we need to do the same for the parm list. We
17553 can't just tsubst the TREE_VEC itself, as tsubst wants to
17554 treat a TREE_VEC as an argument vector. */
17555 parms = copy_node (parms);
17556 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
17557 TREE_VEC_ELT (parms, i) =
17558 tsubst (TREE_VEC_ELT (parms, i), outer_args, tf_none, NULL_TREE);
17562 partial_spec_args =
17563 coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
17564 add_to_template_args (outer_args,
17565 partial_spec_args),
17567 /*require_all_args=*/true,
17568 /*use_default_args=*/true);
17570 --processing_template_decl;
17572 if (partial_spec_args == error_mark_node)
17573 return error_mark_node;
17575 spec_args = get_class_bindings (parms,
17581 spec_args = add_to_template_args (outer_args, spec_args);
17582 list = tree_cons (spec_args, TREE_VALUE (t), list);
17583 TREE_TYPE (list) = TREE_TYPE (t);
17590 ambiguous_p = false;
17593 t = TREE_CHAIN (t);
17594 for (; t; t = TREE_CHAIN (t))
17596 fate = more_specialized_class (champ, t);
17603 t = TREE_CHAIN (t);
17606 ambiguous_p = true;
17615 for (t = list; t && t != champ; t = TREE_CHAIN (t))
17617 fate = more_specialized_class (champ, t);
17620 ambiguous_p = true;
17628 char *spaces = NULL;
17629 if (!(complain & tf_error))
17630 return error_mark_node;
17631 error ("ambiguous class template instantiation for %q#T", type);
17632 str = ngettext ("candidate is:", "candidates are:", list_length (list));
17633 for (t = list; t; t = TREE_CHAIN (t))
17635 error ("%s %+#T", spaces ? spaces : str, TREE_TYPE (t));
17636 spaces = spaces ? spaces : get_spaces (str);
17639 return error_mark_node;
17645 /* Explicitly instantiate DECL. */
17648 do_decl_instantiation (tree decl, tree storage)
17650 tree result = NULL_TREE;
17653 if (!decl || decl == error_mark_node)
17654 /* An error occurred, for which grokdeclarator has already issued
17655 an appropriate message. */
17657 else if (! DECL_LANG_SPECIFIC (decl))
17659 error ("explicit instantiation of non-template %q#D", decl);
17662 else if (TREE_CODE (decl) == VAR_DECL)
17664 /* There is an asymmetry here in the way VAR_DECLs and
17665 FUNCTION_DECLs are handled by grokdeclarator. In the case of
17666 the latter, the DECL we get back will be marked as a
17667 template instantiation, and the appropriate
17668 DECL_TEMPLATE_INFO will be set up. This does not happen for
17669 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
17670 should handle VAR_DECLs as it currently handles
17672 if (!DECL_CLASS_SCOPE_P (decl))
17674 error ("%qD is not a static data member of a class template", decl);
17677 result = lookup_field (DECL_CONTEXT (decl), DECL_NAME (decl), 0, false);
17678 if (!result || TREE_CODE (result) != VAR_DECL)
17680 error ("no matching template for %qD found", decl);
17683 if (!same_type_p (TREE_TYPE (result), TREE_TYPE (decl)))
17685 error ("type %qT for explicit instantiation %qD does not match "
17686 "declared type %qT", TREE_TYPE (result), decl,
17691 else if (TREE_CODE (decl) != FUNCTION_DECL)
17693 error ("explicit instantiation of %q#D", decl);
17699 /* Check for various error cases. Note that if the explicit
17700 instantiation is valid the RESULT will currently be marked as an
17701 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
17702 until we get here. */
17704 if (DECL_TEMPLATE_SPECIALIZATION (result))
17706 /* DR 259 [temp.spec].
17708 Both an explicit instantiation and a declaration of an explicit
17709 specialization shall not appear in a program unless the explicit
17710 instantiation follows a declaration of the explicit specialization.
17712 For a given set of template parameters, if an explicit
17713 instantiation of a template appears after a declaration of an
17714 explicit specialization for that template, the explicit
17715 instantiation has no effect. */
17718 else if (DECL_EXPLICIT_INSTANTIATION (result))
17722 No program shall explicitly instantiate any template more
17725 We check DECL_NOT_REALLY_EXTERN so as not to complain when
17726 the first instantiation was `extern' and the second is not,
17727 and EXTERN_P for the opposite case. */
17728 if (DECL_NOT_REALLY_EXTERN (result) && !extern_p)
17729 permerror (input_location, "duplicate explicit instantiation of %q#D", result);
17730 /* If an "extern" explicit instantiation follows an ordinary
17731 explicit instantiation, the template is instantiated. */
17735 else if (!DECL_IMPLICIT_INSTANTIATION (result))
17737 error ("no matching template for %qD found", result);
17740 else if (!DECL_TEMPLATE_INFO (result))
17742 permerror (input_location, "explicit instantiation of non-template %q#D", result);
17746 if (storage == NULL_TREE)
17748 else if (storage == ridpointers[(int) RID_EXTERN])
17750 if (!in_system_header && (cxx_dialect == cxx98))
17751 pedwarn (input_location, OPT_pedantic,
17752 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
17757 error ("storage class %qD applied to template instantiation", storage);
17759 check_explicit_instantiation_namespace (result);
17760 mark_decl_instantiated (result, extern_p);
17762 instantiate_decl (result, /*defer_ok=*/1,
17763 /*expl_inst_class_mem_p=*/false);
17767 mark_class_instantiated (tree t, int extern_p)
17769 SET_CLASSTYPE_EXPLICIT_INSTANTIATION (t);
17770 SET_CLASSTYPE_INTERFACE_KNOWN (t);
17771 CLASSTYPE_INTERFACE_ONLY (t) = extern_p;
17772 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (t)) = extern_p;
17775 CLASSTYPE_DEBUG_REQUESTED (t) = 1;
17776 rest_of_type_compilation (t, 1);
17780 /* Called from do_type_instantiation through binding_table_foreach to
17781 do recursive instantiation for the type bound in ENTRY. */
17783 bt_instantiate_type_proc (binding_entry entry, void *data)
17785 tree storage = *(tree *) data;
17787 if (MAYBE_CLASS_TYPE_P (entry->type)
17788 && !uses_template_parms (CLASSTYPE_TI_ARGS (entry->type)))
17789 do_type_instantiation (TYPE_MAIN_DECL (entry->type), storage, 0);
17792 /* Called from do_type_instantiation to instantiate a member
17793 (a member function or a static member variable) of an
17794 explicitly instantiated class template. */
17796 instantiate_class_member (tree decl, int extern_p)
17798 mark_decl_instantiated (decl, extern_p);
17800 instantiate_decl (decl, /*defer_ok=*/1,
17801 /*expl_inst_class_mem_p=*/true);
17804 /* Perform an explicit instantiation of template class T. STORAGE, if
17805 non-null, is the RID for extern, inline or static. COMPLAIN is
17806 nonzero if this is called from the parser, zero if called recursively,
17807 since the standard is unclear (as detailed below). */
17810 do_type_instantiation (tree t, tree storage, tsubst_flags_t complain)
17815 int previous_instantiation_extern_p = 0;
17817 if (TREE_CODE (t) == TYPE_DECL)
17820 if (! CLASS_TYPE_P (t) || ! CLASSTYPE_TEMPLATE_INFO (t))
17823 (TYPE_TEMPLATE_INFO (t)) ? TYPE_TI_TEMPLATE (t) : NULL;
17825 error ("explicit instantiation of non-class template %qD", tmpl);
17827 error ("explicit instantiation of non-template type %qT", t);
17833 if (!COMPLETE_TYPE_P (t))
17835 if (complain & tf_error)
17836 error ("explicit instantiation of %q#T before definition of template",
17841 if (storage != NULL_TREE)
17843 if (!in_system_header)
17845 if (storage == ridpointers[(int) RID_EXTERN])
17847 if (cxx_dialect == cxx98)
17848 pedwarn (input_location, OPT_pedantic,
17849 "ISO C++ 1998 forbids the use of %<extern%> on "
17850 "explicit instantiations");
17853 pedwarn (input_location, OPT_pedantic,
17854 "ISO C++ forbids the use of %qE"
17855 " on explicit instantiations", storage);
17858 if (storage == ridpointers[(int) RID_INLINE])
17860 else if (storage == ridpointers[(int) RID_EXTERN])
17862 else if (storage == ridpointers[(int) RID_STATIC])
17866 error ("storage class %qD applied to template instantiation",
17872 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (t))
17874 /* DR 259 [temp.spec].
17876 Both an explicit instantiation and a declaration of an explicit
17877 specialization shall not appear in a program unless the explicit
17878 instantiation follows a declaration of the explicit specialization.
17880 For a given set of template parameters, if an explicit
17881 instantiation of a template appears after a declaration of an
17882 explicit specialization for that template, the explicit
17883 instantiation has no effect. */
17886 else if (CLASSTYPE_EXPLICIT_INSTANTIATION (t))
17890 No program shall explicitly instantiate any template more
17893 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
17894 instantiation was `extern'. If EXTERN_P then the second is.
17895 These cases are OK. */
17896 previous_instantiation_extern_p = CLASSTYPE_INTERFACE_ONLY (t);
17898 if (!previous_instantiation_extern_p && !extern_p
17899 && (complain & tf_error))
17900 permerror (input_location, "duplicate explicit instantiation of %q#T", t);
17902 /* If we've already instantiated the template, just return now. */
17903 if (!CLASSTYPE_INTERFACE_ONLY (t))
17907 check_explicit_instantiation_namespace (TYPE_NAME (t));
17908 mark_class_instantiated (t, extern_p);
17916 /* In contrast to implicit instantiation, where only the
17917 declarations, and not the definitions, of members are
17918 instantiated, we have here:
17922 The explicit instantiation of a class template specialization
17923 implies the instantiation of all of its members not
17924 previously explicitly specialized in the translation unit
17925 containing the explicit instantiation.
17927 Of course, we can't instantiate member template classes, since
17928 we don't have any arguments for them. Note that the standard
17929 is unclear on whether the instantiation of the members are
17930 *explicit* instantiations or not. However, the most natural
17931 interpretation is that it should be an explicit instantiation. */
17934 for (tmp = TYPE_METHODS (t); tmp; tmp = DECL_CHAIN (tmp))
17935 if (TREE_CODE (tmp) == FUNCTION_DECL
17936 && DECL_TEMPLATE_INSTANTIATION (tmp))
17937 instantiate_class_member (tmp, extern_p);
17939 for (tmp = TYPE_FIELDS (t); tmp; tmp = DECL_CHAIN (tmp))
17940 if (TREE_CODE (tmp) == VAR_DECL && DECL_TEMPLATE_INSTANTIATION (tmp))
17941 instantiate_class_member (tmp, extern_p);
17943 if (CLASSTYPE_NESTED_UTDS (t))
17944 binding_table_foreach (CLASSTYPE_NESTED_UTDS (t),
17945 bt_instantiate_type_proc, &storage);
17949 /* Given a function DECL, which is a specialization of TMPL, modify
17950 DECL to be a re-instantiation of TMPL with the same template
17951 arguments. TMPL should be the template into which tsubst'ing
17952 should occur for DECL, not the most general template.
17954 One reason for doing this is a scenario like this:
17957 void f(const T&, int i);
17959 void g() { f(3, 7); }
17962 void f(const T& t, const int i) { }
17964 Note that when the template is first instantiated, with
17965 instantiate_template, the resulting DECL will have no name for the
17966 first parameter, and the wrong type for the second. So, when we go
17967 to instantiate the DECL, we regenerate it. */
17970 regenerate_decl_from_template (tree decl, tree tmpl)
17972 /* The arguments used to instantiate DECL, from the most general
17977 args = DECL_TI_ARGS (decl);
17978 code_pattern = DECL_TEMPLATE_RESULT (tmpl);
17980 /* Make sure that we can see identifiers, and compute access
17982 push_access_scope (decl);
17984 if (TREE_CODE (decl) == FUNCTION_DECL)
17992 args_depth = TMPL_ARGS_DEPTH (args);
17993 parms_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
17994 if (args_depth > parms_depth)
17995 args = get_innermost_template_args (args, parms_depth);
17997 specs = tsubst_exception_specification (TREE_TYPE (code_pattern),
17998 args, tf_error, NULL_TREE,
17999 /*defer_ok*/false);
18000 if (specs && specs != error_mark_node)
18001 TREE_TYPE (decl) = build_exception_variant (TREE_TYPE (decl),
18004 /* Merge parameter declarations. */
18005 decl_parm = skip_artificial_parms_for (decl,
18006 DECL_ARGUMENTS (decl));
18008 = skip_artificial_parms_for (code_pattern,
18009 DECL_ARGUMENTS (code_pattern));
18010 while (decl_parm && !FUNCTION_PARAMETER_PACK_P (pattern_parm))
18015 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
18016 DECL_NAME (decl_parm) = DECL_NAME (pattern_parm);
18017 parm_type = tsubst (TREE_TYPE (pattern_parm), args, tf_error,
18019 parm_type = type_decays_to (parm_type);
18020 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
18021 TREE_TYPE (decl_parm) = parm_type;
18022 attributes = DECL_ATTRIBUTES (pattern_parm);
18023 if (DECL_ATTRIBUTES (decl_parm) != attributes)
18025 DECL_ATTRIBUTES (decl_parm) = attributes;
18026 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
18028 decl_parm = DECL_CHAIN (decl_parm);
18029 pattern_parm = DECL_CHAIN (pattern_parm);
18031 /* Merge any parameters that match with the function parameter
18033 if (pattern_parm && FUNCTION_PARAMETER_PACK_P (pattern_parm))
18036 tree expanded_types;
18037 /* Expand the TYPE_PACK_EXPANSION that provides the types for
18038 the parameters in this function parameter pack. */
18039 expanded_types = tsubst_pack_expansion (TREE_TYPE (pattern_parm),
18040 args, tf_error, NULL_TREE);
18041 len = TREE_VEC_LENGTH (expanded_types);
18042 for (i = 0; i < len; i++)
18047 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
18048 /* Rename the parameter to include the index. */
18049 DECL_NAME (decl_parm) =
18050 make_ith_pack_parameter_name (DECL_NAME (pattern_parm), i);
18051 parm_type = TREE_VEC_ELT (expanded_types, i);
18052 parm_type = type_decays_to (parm_type);
18053 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
18054 TREE_TYPE (decl_parm) = parm_type;
18055 attributes = DECL_ATTRIBUTES (pattern_parm);
18056 if (DECL_ATTRIBUTES (decl_parm) != attributes)
18058 DECL_ATTRIBUTES (decl_parm) = attributes;
18059 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
18061 decl_parm = DECL_CHAIN (decl_parm);
18064 /* Merge additional specifiers from the CODE_PATTERN. */
18065 if (DECL_DECLARED_INLINE_P (code_pattern)
18066 && !DECL_DECLARED_INLINE_P (decl))
18067 DECL_DECLARED_INLINE_P (decl) = 1;
18069 else if (TREE_CODE (decl) == VAR_DECL)
18071 DECL_INITIAL (decl) =
18072 tsubst_expr (DECL_INITIAL (code_pattern), args,
18073 tf_error, DECL_TI_TEMPLATE (decl),
18074 /*integral_constant_expression_p=*/false);
18075 if (VAR_HAD_UNKNOWN_BOUND (decl))
18076 TREE_TYPE (decl) = tsubst (TREE_TYPE (code_pattern), args,
18077 tf_error, DECL_TI_TEMPLATE (decl));
18080 gcc_unreachable ();
18082 pop_access_scope (decl);
18085 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
18086 substituted to get DECL. */
18089 template_for_substitution (tree decl)
18091 tree tmpl = DECL_TI_TEMPLATE (decl);
18093 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
18094 for the instantiation. This is not always the most general
18095 template. Consider, for example:
18098 struct S { template <class U> void f();
18099 template <> void f<int>(); };
18101 and an instantiation of S<double>::f<int>. We want TD to be the
18102 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
18103 while (/* An instantiation cannot have a definition, so we need a
18104 more general template. */
18105 DECL_TEMPLATE_INSTANTIATION (tmpl)
18106 /* We must also deal with friend templates. Given:
18108 template <class T> struct S {
18109 template <class U> friend void f() {};
18112 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
18113 so far as the language is concerned, but that's still
18114 where we get the pattern for the instantiation from. On
18115 other hand, if the definition comes outside the class, say:
18117 template <class T> struct S {
18118 template <class U> friend void f();
18120 template <class U> friend void f() {}
18122 we don't need to look any further. That's what the check for
18123 DECL_INITIAL is for. */
18124 || (TREE_CODE (decl) == FUNCTION_DECL
18125 && DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION (tmpl)
18126 && !DECL_INITIAL (DECL_TEMPLATE_RESULT (tmpl))))
18128 /* The present template, TD, should not be a definition. If it
18129 were a definition, we should be using it! Note that we
18130 cannot restructure the loop to just keep going until we find
18131 a template with a definition, since that might go too far if
18132 a specialization was declared, but not defined. */
18133 gcc_assert (TREE_CODE (decl) != VAR_DECL
18134 || DECL_IN_AGGR_P (DECL_TEMPLATE_RESULT (tmpl)));
18136 /* Fetch the more general template. */
18137 tmpl = DECL_TI_TEMPLATE (tmpl);
18143 /* Returns true if we need to instantiate this template instance even if we
18144 know we aren't going to emit it.. */
18147 always_instantiate_p (tree decl)
18149 /* We always instantiate inline functions so that we can inline them. An
18150 explicit instantiation declaration prohibits implicit instantiation of
18151 non-inline functions. With high levels of optimization, we would
18152 normally inline non-inline functions -- but we're not allowed to do
18153 that for "extern template" functions. Therefore, we check
18154 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
18155 return ((TREE_CODE (decl) == FUNCTION_DECL
18156 && DECL_DECLARED_INLINE_P (decl))
18157 /* And we need to instantiate static data members so that
18158 their initializers are available in integral constant
18160 || (TREE_CODE (decl) == VAR_DECL
18161 && decl_maybe_constant_var_p (decl)));
18164 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
18165 instantiate it now, modifying TREE_TYPE (fn). */
18168 maybe_instantiate_noexcept (tree fn)
18170 tree fntype, spec, noex, clone;
18172 if (DECL_CLONED_FUNCTION_P (fn))
18173 fn = DECL_CLONED_FUNCTION (fn);
18174 fntype = TREE_TYPE (fn);
18175 spec = TYPE_RAISES_EXCEPTIONS (fntype);
18177 if (!DEFERRED_NOEXCEPT_SPEC_P (spec))
18180 noex = TREE_PURPOSE (spec);
18182 if (TREE_CODE (noex) == DEFERRED_NOEXCEPT)
18184 if (push_tinst_level (fn))
18186 push_access_scope (fn);
18187 input_location = DECL_SOURCE_LOCATION (fn);
18188 noex = tsubst_copy_and_build (DEFERRED_NOEXCEPT_PATTERN (noex),
18189 DEFERRED_NOEXCEPT_ARGS (noex),
18190 tf_warning_or_error, fn,
18191 /*function_p=*/false,
18192 /*integral_constant_expression_p=*/true);
18193 pop_access_scope (fn);
18194 pop_tinst_level ();
18195 spec = build_noexcept_spec (noex, tf_warning_or_error);
18196 if (spec == error_mark_node)
18197 spec = noexcept_false_spec;
18200 spec = noexcept_false_spec;
18204 /* This is an implicitly declared function, so NOEX is a list of
18205 other functions to evaluate and merge. */
18207 spec = noexcept_true_spec;
18208 for (elt = noex; elt; elt = OVL_NEXT (elt))
18210 tree fn = OVL_CURRENT (elt);
18212 maybe_instantiate_noexcept (fn);
18213 subspec = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (fn));
18214 spec = merge_exception_specifiers (spec, subspec, NULL_TREE);
18218 TREE_TYPE (fn) = build_exception_variant (fntype, spec);
18220 FOR_EACH_CLONE (clone, fn)
18222 if (TREE_TYPE (clone) == fntype)
18223 TREE_TYPE (clone) = TREE_TYPE (fn);
18225 TREE_TYPE (clone) = build_exception_variant (TREE_TYPE (clone), spec);
18229 /* Produce the definition of D, a _DECL generated from a template. If
18230 DEFER_OK is nonzero, then we don't have to actually do the
18231 instantiation now; we just have to do it sometime. Normally it is
18232 an error if this is an explicit instantiation but D is undefined.
18233 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
18234 explicitly instantiated class template. */
18237 instantiate_decl (tree d, int defer_ok,
18238 bool expl_inst_class_mem_p)
18240 tree tmpl = DECL_TI_TEMPLATE (d);
18247 bool pattern_defined;
18249 location_t saved_loc = input_location;
18252 /* This function should only be used to instantiate templates for
18253 functions and static member variables. */
18254 gcc_assert (TREE_CODE (d) == FUNCTION_DECL
18255 || TREE_CODE (d) == VAR_DECL);
18257 /* Variables are never deferred; if instantiation is required, they
18258 are instantiated right away. That allows for better code in the
18259 case that an expression refers to the value of the variable --
18260 if the variable has a constant value the referring expression can
18261 take advantage of that fact. */
18262 if (TREE_CODE (d) == VAR_DECL
18263 || DECL_DECLARED_CONSTEXPR_P (d))
18266 /* Don't instantiate cloned functions. Instead, instantiate the
18267 functions they cloned. */
18268 if (TREE_CODE (d) == FUNCTION_DECL && DECL_CLONED_FUNCTION_P (d))
18269 d = DECL_CLONED_FUNCTION (d);
18271 if (DECL_TEMPLATE_INSTANTIATED (d)
18272 || (TREE_CODE (d) == FUNCTION_DECL
18273 && DECL_DEFAULTED_FN (d) && DECL_INITIAL (d))
18274 || DECL_TEMPLATE_SPECIALIZATION (d))
18275 /* D has already been instantiated or explicitly specialized, so
18276 there's nothing for us to do here.
18278 It might seem reasonable to check whether or not D is an explicit
18279 instantiation, and, if so, stop here. But when an explicit
18280 instantiation is deferred until the end of the compilation,
18281 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
18282 the instantiation. */
18285 /* Check to see whether we know that this template will be
18286 instantiated in some other file, as with "extern template"
18288 external_p = (DECL_INTERFACE_KNOWN (d) && DECL_REALLY_EXTERN (d));
18290 /* In general, we do not instantiate such templates. */
18291 if (external_p && !always_instantiate_p (d))
18294 gen_tmpl = most_general_template (tmpl);
18295 gen_args = DECL_TI_ARGS (d);
18297 if (tmpl != gen_tmpl)
18298 /* We should already have the extra args. */
18299 gcc_assert (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (gen_tmpl))
18300 == TMPL_ARGS_DEPTH (gen_args));
18301 /* And what's in the hash table should match D. */
18302 gcc_assert ((spec = retrieve_specialization (gen_tmpl, gen_args, 0)) == d
18303 || spec == NULL_TREE);
18305 /* This needs to happen before any tsubsting. */
18306 if (! push_tinst_level (d))
18309 timevar_push (TV_TEMPLATE_INST);
18311 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
18312 for the instantiation. */
18313 td = template_for_substitution (d);
18314 code_pattern = DECL_TEMPLATE_RESULT (td);
18316 /* We should never be trying to instantiate a member of a class
18317 template or partial specialization. */
18318 gcc_assert (d != code_pattern);
18320 if ((DECL_NAMESPACE_SCOPE_P (d) && !DECL_INITIALIZED_IN_CLASS_P (d))
18321 || DECL_TEMPLATE_SPECIALIZATION (td))
18322 /* In the case of a friend template whose definition is provided
18323 outside the class, we may have too many arguments. Drop the
18324 ones we don't need. The same is true for specializations. */
18325 args = get_innermost_template_args
18326 (gen_args, TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (td)));
18330 if (TREE_CODE (d) == FUNCTION_DECL)
18331 pattern_defined = (DECL_SAVED_TREE (code_pattern) != NULL_TREE
18332 || DECL_DEFAULTED_OUTSIDE_CLASS_P (code_pattern));
18334 pattern_defined = ! DECL_IN_AGGR_P (code_pattern);
18336 /* We may be in the middle of deferred access check. Disable it now. */
18337 push_deferring_access_checks (dk_no_deferred);
18339 /* Unless an explicit instantiation directive has already determined
18340 the linkage of D, remember that a definition is available for
18342 if (pattern_defined
18343 && !DECL_INTERFACE_KNOWN (d)
18344 && !DECL_NOT_REALLY_EXTERN (d))
18345 mark_definable (d);
18347 DECL_SOURCE_LOCATION (td) = DECL_SOURCE_LOCATION (code_pattern);
18348 DECL_SOURCE_LOCATION (d) = DECL_SOURCE_LOCATION (code_pattern);
18349 input_location = DECL_SOURCE_LOCATION (d);
18351 /* If D is a member of an explicitly instantiated class template,
18352 and no definition is available, treat it like an implicit
18354 if (!pattern_defined && expl_inst_class_mem_p
18355 && DECL_EXPLICIT_INSTANTIATION (d))
18357 /* Leave linkage flags alone on instantiations with anonymous
18359 if (TREE_PUBLIC (d))
18361 DECL_NOT_REALLY_EXTERN (d) = 0;
18362 DECL_INTERFACE_KNOWN (d) = 0;
18364 SET_DECL_IMPLICIT_INSTANTIATION (d);
18367 if (TREE_CODE (d) == FUNCTION_DECL)
18368 maybe_instantiate_noexcept (d);
18370 /* Recheck the substitutions to obtain any warning messages
18371 about ignoring cv qualifiers. Don't do this for artificial decls,
18372 as it breaks the context-sensitive substitution for lambda op(). */
18373 if (!defer_ok && !DECL_ARTIFICIAL (d))
18375 tree gen = DECL_TEMPLATE_RESULT (gen_tmpl);
18376 tree type = TREE_TYPE (gen);
18378 /* Make sure that we can see identifiers, and compute access
18379 correctly. D is already the target FUNCTION_DECL with the
18381 push_access_scope (d);
18383 if (TREE_CODE (gen) == FUNCTION_DECL)
18385 tsubst (DECL_ARGUMENTS (gen), gen_args, tf_warning_or_error, d);
18386 tsubst_exception_specification (type, gen_args, tf_warning_or_error,
18387 d, /*defer_ok*/true);
18388 /* Don't simply tsubst the function type, as that will give
18389 duplicate warnings about poor parameter qualifications.
18390 The function arguments are the same as the decl_arguments
18391 without the top level cv qualifiers. */
18392 type = TREE_TYPE (type);
18394 tsubst (type, gen_args, tf_warning_or_error, d);
18396 pop_access_scope (d);
18399 /* Defer all other templates, unless we have been explicitly
18400 forbidden from doing so. */
18401 if (/* If there is no definition, we cannot instantiate the
18404 /* If it's OK to postpone instantiation, do so. */
18406 /* If this is a static data member that will be defined
18407 elsewhere, we don't want to instantiate the entire data
18408 member, but we do want to instantiate the initializer so that
18409 we can substitute that elsewhere. */
18410 || (external_p && TREE_CODE (d) == VAR_DECL))
18412 /* The definition of the static data member is now required so
18413 we must substitute the initializer. */
18414 if (TREE_CODE (d) == VAR_DECL
18415 && !DECL_INITIAL (d)
18416 && DECL_INITIAL (code_pattern))
18420 bool const_init = false;
18422 ns = decl_namespace_context (d);
18423 push_nested_namespace (ns);
18424 push_nested_class (DECL_CONTEXT (d));
18425 init = tsubst_expr (DECL_INITIAL (code_pattern),
18427 tf_warning_or_error, NULL_TREE,
18428 /*integral_constant_expression_p=*/false);
18429 /* Make sure the initializer is still constant, in case of
18430 circular dependency (template/instantiate6.C). */
18432 = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (code_pattern);
18433 cp_finish_decl (d, init, /*init_const_expr_p=*/const_init,
18434 /*asmspec_tree=*/NULL_TREE,
18435 LOOKUP_ONLYCONVERTING);
18436 pop_nested_class ();
18437 pop_nested_namespace (ns);
18440 /* We restore the source position here because it's used by
18441 add_pending_template. */
18442 input_location = saved_loc;
18444 if (at_eof && !pattern_defined
18445 && DECL_EXPLICIT_INSTANTIATION (d)
18446 && DECL_NOT_REALLY_EXTERN (d))
18449 The definition of a non-exported function template, a
18450 non-exported member function template, or a non-exported
18451 member function or static data member of a class template
18452 shall be present in every translation unit in which it is
18453 explicitly instantiated. */
18454 permerror (input_location, "explicit instantiation of %qD "
18455 "but no definition available", d);
18457 /* If we're in unevaluated context, we just wanted to get the
18458 constant value; this isn't an odr use, so don't queue
18459 a full instantiation. */
18460 if (cp_unevaluated_operand != 0)
18462 /* ??? Historically, we have instantiated inline functions, even
18463 when marked as "extern template". */
18464 if (!(external_p && TREE_CODE (d) == VAR_DECL))
18465 add_pending_template (d);
18468 /* Tell the repository that D is available in this translation unit
18469 -- and see if it is supposed to be instantiated here. */
18470 if (TREE_PUBLIC (d) && !DECL_REALLY_EXTERN (d) && !repo_emit_p (d))
18472 /* In a PCH file, despite the fact that the repository hasn't
18473 requested instantiation in the PCH it is still possible that
18474 an instantiation will be required in a file that includes the
18477 add_pending_template (d);
18478 /* Instantiate inline functions so that the inliner can do its
18479 job, even though we'll not be emitting a copy of this
18481 if (!(TREE_CODE (d) == FUNCTION_DECL && possibly_inlined_p (d)))
18485 need_push = !cfun || !global_bindings_p ();
18487 push_to_top_level ();
18489 /* Mark D as instantiated so that recursive calls to
18490 instantiate_decl do not try to instantiate it again. */
18491 DECL_TEMPLATE_INSTANTIATED (d) = 1;
18493 /* Regenerate the declaration in case the template has been modified
18494 by a subsequent redeclaration. */
18495 regenerate_decl_from_template (d, td);
18497 /* We already set the file and line above. Reset them now in case
18498 they changed as a result of calling regenerate_decl_from_template. */
18499 input_location = DECL_SOURCE_LOCATION (d);
18501 if (TREE_CODE (d) == VAR_DECL)
18504 bool const_init = false;
18506 /* Clear out DECL_RTL; whatever was there before may not be right
18507 since we've reset the type of the declaration. */
18508 SET_DECL_RTL (d, NULL);
18509 DECL_IN_AGGR_P (d) = 0;
18511 /* The initializer is placed in DECL_INITIAL by
18512 regenerate_decl_from_template so we don't need to
18513 push/pop_access_scope again here. Pull it out so that
18514 cp_finish_decl can process it. */
18515 init = DECL_INITIAL (d);
18516 DECL_INITIAL (d) = NULL_TREE;
18517 DECL_INITIALIZED_P (d) = 0;
18519 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
18520 initializer. That function will defer actual emission until
18521 we have a chance to determine linkage. */
18522 DECL_EXTERNAL (d) = 0;
18524 /* Enter the scope of D so that access-checking works correctly. */
18525 push_nested_class (DECL_CONTEXT (d));
18526 const_init = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (code_pattern);
18527 cp_finish_decl (d, init, const_init, NULL_TREE, 0);
18528 pop_nested_class ();
18530 else if (TREE_CODE (d) == FUNCTION_DECL && DECL_DEFAULTED_FN (code_pattern))
18531 synthesize_method (d);
18532 else if (TREE_CODE (d) == FUNCTION_DECL)
18534 htab_t saved_local_specializations;
18539 /* Save away the current list, in case we are instantiating one
18540 template from within the body of another. */
18541 saved_local_specializations = local_specializations;
18543 /* Set up the list of local specializations. */
18544 local_specializations = htab_create (37,
18545 hash_local_specialization,
18546 eq_local_specializations,
18549 /* Set up context. */
18550 start_preparsed_function (d, NULL_TREE, SF_PRE_PARSED);
18552 /* Create substitution entries for the parameters. */
18553 subst_decl = DECL_TEMPLATE_RESULT (template_for_substitution (d));
18554 tmpl_parm = DECL_ARGUMENTS (subst_decl);
18555 spec_parm = DECL_ARGUMENTS (d);
18556 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (d))
18558 register_local_specialization (spec_parm, tmpl_parm);
18559 spec_parm = skip_artificial_parms_for (d, spec_parm);
18560 tmpl_parm = skip_artificial_parms_for (subst_decl, tmpl_parm);
18562 for (; tmpl_parm; tmpl_parm = DECL_CHAIN (tmpl_parm))
18564 if (!FUNCTION_PARAMETER_PACK_P (tmpl_parm))
18566 register_local_specialization (spec_parm, tmpl_parm);
18567 spec_parm = DECL_CHAIN (spec_parm);
18571 /* Register the (value) argument pack as a specialization of
18572 TMPL_PARM, then move on. */
18573 tree argpack = extract_fnparm_pack (tmpl_parm, &spec_parm);
18574 register_local_specialization (argpack, tmpl_parm);
18577 gcc_assert (!spec_parm);
18579 /* Substitute into the body of the function. */
18580 tsubst_expr (DECL_SAVED_TREE (code_pattern), args,
18581 tf_warning_or_error, tmpl,
18582 /*integral_constant_expression_p=*/false);
18584 /* Set the current input_location to the end of the function
18585 so that finish_function knows where we are. */
18586 input_location = DECL_STRUCT_FUNCTION (code_pattern)->function_end_locus;
18588 /* We don't need the local specializations any more. */
18589 htab_delete (local_specializations);
18590 local_specializations = saved_local_specializations;
18592 /* Finish the function. */
18593 d = finish_function (0);
18594 expand_or_defer_fn (d);
18597 /* We're not deferring instantiation any more. */
18598 TI_PENDING_TEMPLATE_FLAG (DECL_TEMPLATE_INFO (d)) = 0;
18601 pop_from_top_level ();
18604 input_location = saved_loc;
18605 pop_deferring_access_checks ();
18606 pop_tinst_level ();
18608 timevar_pop (TV_TEMPLATE_INST);
18613 /* Run through the list of templates that we wish we could
18614 instantiate, and instantiate any we can. RETRIES is the
18615 number of times we retry pending template instantiation. */
18618 instantiate_pending_templates (int retries)
18621 location_t saved_loc = input_location;
18623 /* Instantiating templates may trigger vtable generation. This in turn
18624 may require further template instantiations. We place a limit here
18625 to avoid infinite loop. */
18626 if (pending_templates && retries >= max_tinst_depth)
18628 tree decl = pending_templates->tinst->decl;
18630 error ("template instantiation depth exceeds maximum of %d"
18631 " instantiating %q+D, possibly from virtual table generation"
18632 " (use -ftemplate-depth= to increase the maximum)",
18633 max_tinst_depth, decl);
18634 if (TREE_CODE (decl) == FUNCTION_DECL)
18635 /* Pretend that we defined it. */
18636 DECL_INITIAL (decl) = error_mark_node;
18642 struct pending_template **t = &pending_templates;
18643 struct pending_template *last = NULL;
18647 tree instantiation = reopen_tinst_level ((*t)->tinst);
18648 bool complete = false;
18650 if (TYPE_P (instantiation))
18654 if (!COMPLETE_TYPE_P (instantiation))
18656 instantiate_class_template (instantiation);
18657 if (CLASSTYPE_TEMPLATE_INSTANTIATION (instantiation))
18658 for (fn = TYPE_METHODS (instantiation);
18660 fn = TREE_CHAIN (fn))
18661 if (! DECL_ARTIFICIAL (fn))
18662 instantiate_decl (fn,
18664 /*expl_inst_class_mem_p=*/false);
18665 if (COMPLETE_TYPE_P (instantiation))
18669 complete = COMPLETE_TYPE_P (instantiation);
18673 if (!DECL_TEMPLATE_SPECIALIZATION (instantiation)
18674 && !DECL_TEMPLATE_INSTANTIATED (instantiation))
18677 = instantiate_decl (instantiation,
18679 /*expl_inst_class_mem_p=*/false);
18680 if (DECL_TEMPLATE_INSTANTIATED (instantiation))
18684 complete = (DECL_TEMPLATE_SPECIALIZATION (instantiation)
18685 || DECL_TEMPLATE_INSTANTIATED (instantiation));
18689 /* If INSTANTIATION has been instantiated, then we don't
18690 need to consider it again in the future. */
18698 current_tinst_level = NULL;
18700 last_pending_template = last;
18702 while (reconsider);
18704 input_location = saved_loc;
18707 /* Substitute ARGVEC into T, which is a list of initializers for
18708 either base class or a non-static data member. The TREE_PURPOSEs
18709 are DECLs, and the TREE_VALUEs are the initializer values. Used by
18710 instantiate_decl. */
18713 tsubst_initializer_list (tree t, tree argvec)
18715 tree inits = NULL_TREE;
18717 for (; t; t = TREE_CHAIN (t))
18721 tree expanded_bases = NULL_TREE;
18722 tree expanded_arguments = NULL_TREE;
18725 if (TREE_CODE (TREE_PURPOSE (t)) == TYPE_PACK_EXPANSION)
18730 /* Expand the base class expansion type into separate base
18732 expanded_bases = tsubst_pack_expansion (TREE_PURPOSE (t), argvec,
18733 tf_warning_or_error,
18735 if (expanded_bases == error_mark_node)
18738 /* We'll be building separate TREE_LISTs of arguments for
18740 len = TREE_VEC_LENGTH (expanded_bases);
18741 expanded_arguments = make_tree_vec (len);
18742 for (i = 0; i < len; i++)
18743 TREE_VEC_ELT (expanded_arguments, i) = NULL_TREE;
18745 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
18746 expand each argument in the TREE_VALUE of t. */
18747 expr = make_node (EXPR_PACK_EXPANSION);
18748 PACK_EXPANSION_PARAMETER_PACKS (expr) =
18749 PACK_EXPANSION_PARAMETER_PACKS (TREE_PURPOSE (t));
18751 if (TREE_VALUE (t) == void_type_node)
18752 /* VOID_TYPE_NODE is used to indicate
18753 value-initialization. */
18755 for (i = 0; i < len; i++)
18756 TREE_VEC_ELT (expanded_arguments, i) = void_type_node;
18760 /* Substitute parameter packs into each argument in the
18762 in_base_initializer = 1;
18763 for (arg = TREE_VALUE (t); arg; arg = TREE_CHAIN (arg))
18765 tree expanded_exprs;
18767 /* Expand the argument. */
18768 SET_PACK_EXPANSION_PATTERN (expr, TREE_VALUE (arg));
18770 = tsubst_pack_expansion (expr, argvec,
18771 tf_warning_or_error,
18773 if (expanded_exprs == error_mark_node)
18776 /* Prepend each of the expanded expressions to the
18777 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
18778 for (i = 0; i < len; i++)
18780 TREE_VEC_ELT (expanded_arguments, i) =
18781 tree_cons (NULL_TREE,
18782 TREE_VEC_ELT (expanded_exprs, i),
18783 TREE_VEC_ELT (expanded_arguments, i));
18786 in_base_initializer = 0;
18788 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
18789 since we built them backwards. */
18790 for (i = 0; i < len; i++)
18792 TREE_VEC_ELT (expanded_arguments, i) =
18793 nreverse (TREE_VEC_ELT (expanded_arguments, i));
18798 for (i = 0; i < len; ++i)
18800 if (expanded_bases)
18802 decl = TREE_VEC_ELT (expanded_bases, i);
18803 decl = expand_member_init (decl);
18804 init = TREE_VEC_ELT (expanded_arguments, i);
18808 decl = tsubst_copy (TREE_PURPOSE (t), argvec,
18809 tf_warning_or_error, NULL_TREE);
18811 decl = expand_member_init (decl);
18812 if (decl && !DECL_P (decl))
18813 in_base_initializer = 1;
18815 init = TREE_VALUE (t);
18816 if (init != void_type_node)
18817 init = tsubst_expr (init, argvec,
18818 tf_warning_or_error, NULL_TREE,
18819 /*integral_constant_expression_p=*/false);
18820 in_base_initializer = 0;
18825 init = build_tree_list (decl, init);
18826 TREE_CHAIN (init) = inits;
18834 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
18837 set_current_access_from_decl (tree decl)
18839 if (TREE_PRIVATE (decl))
18840 current_access_specifier = access_private_node;
18841 else if (TREE_PROTECTED (decl))
18842 current_access_specifier = access_protected_node;
18844 current_access_specifier = access_public_node;
18847 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
18848 is the instantiation (which should have been created with
18849 start_enum) and ARGS are the template arguments to use. */
18852 tsubst_enum (tree tag, tree newtag, tree args)
18856 if (SCOPED_ENUM_P (newtag))
18857 begin_scope (sk_scoped_enum, newtag);
18859 for (e = TYPE_VALUES (tag); e; e = TREE_CHAIN (e))
18864 decl = TREE_VALUE (e);
18865 /* Note that in a template enum, the TREE_VALUE is the
18866 CONST_DECL, not the corresponding INTEGER_CST. */
18867 value = tsubst_expr (DECL_INITIAL (decl),
18868 args, tf_warning_or_error, NULL_TREE,
18869 /*integral_constant_expression_p=*/true);
18871 /* Give this enumeration constant the correct access. */
18872 set_current_access_from_decl (decl);
18874 /* Actually build the enumerator itself. */
18876 (DECL_NAME (decl), value, newtag, DECL_SOURCE_LOCATION (decl));
18879 if (SCOPED_ENUM_P (newtag))
18882 finish_enum_value_list (newtag);
18883 finish_enum (newtag);
18885 DECL_SOURCE_LOCATION (TYPE_NAME (newtag))
18886 = DECL_SOURCE_LOCATION (TYPE_NAME (tag));
18889 /* DECL is a FUNCTION_DECL that is a template specialization. Return
18890 its type -- but without substituting the innermost set of template
18891 arguments. So, innermost set of template parameters will appear in
18895 get_mostly_instantiated_function_type (tree decl)
18903 tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
18904 targs = DECL_TI_ARGS (decl);
18905 tparms = DECL_TEMPLATE_PARMS (tmpl);
18906 parm_depth = TMPL_PARMS_DEPTH (tparms);
18908 /* There should be as many levels of arguments as there are levels
18910 gcc_assert (parm_depth == TMPL_ARGS_DEPTH (targs));
18912 fn_type = TREE_TYPE (tmpl);
18914 if (parm_depth == 1)
18915 /* No substitution is necessary. */
18922 /* Replace the innermost level of the TARGS with NULL_TREEs to
18923 let tsubst know not to substitute for those parameters. */
18924 partial_args = make_tree_vec (TREE_VEC_LENGTH (targs));
18925 for (i = 1; i < TMPL_ARGS_DEPTH (targs); ++i)
18926 SET_TMPL_ARGS_LEVEL (partial_args, i,
18927 TMPL_ARGS_LEVEL (targs, i));
18928 SET_TMPL_ARGS_LEVEL (partial_args,
18929 TMPL_ARGS_DEPTH (targs),
18930 make_tree_vec (DECL_NTPARMS (tmpl)));
18932 /* Make sure that we can see identifiers, and compute access
18934 push_access_scope (decl);
18936 ++processing_template_decl;
18937 /* Now, do the (partial) substitution to figure out the
18938 appropriate function type. */
18939 fn_type = tsubst (fn_type, partial_args, tf_error, NULL_TREE);
18940 --processing_template_decl;
18942 /* Substitute into the template parameters to obtain the real
18943 innermost set of parameters. This step is important if the
18944 innermost set of template parameters contains value
18945 parameters whose types depend on outer template parameters. */
18946 TREE_VEC_LENGTH (partial_args)--;
18947 tparms = tsubst_template_parms (tparms, partial_args, tf_error);
18949 pop_access_scope (decl);
18955 /* Return truthvalue if we're processing a template different from
18956 the last one involved in diagnostics. */
18958 problematic_instantiation_changed (void)
18960 return current_tinst_level != last_error_tinst_level;
18963 /* Remember current template involved in diagnostics. */
18965 record_last_problematic_instantiation (void)
18967 last_error_tinst_level = current_tinst_level;
18970 struct tinst_level *
18971 current_instantiation (void)
18973 return current_tinst_level;
18976 /* [temp.param] Check that template non-type parm TYPE is of an allowable
18977 type. Return zero for ok, nonzero for disallowed. Issue error and
18978 warning messages under control of COMPLAIN. */
18981 invalid_nontype_parm_type_p (tree type, tsubst_flags_t complain)
18983 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
18985 else if (POINTER_TYPE_P (type))
18987 else if (TYPE_PTR_TO_MEMBER_P (type))
18989 else if (TREE_CODE (type) == TEMPLATE_TYPE_PARM)
18991 else if (TREE_CODE (type) == TYPENAME_TYPE)
18993 else if (TREE_CODE (type) == DECLTYPE_TYPE)
18995 else if (TREE_CODE (type) == NULLPTR_TYPE)
18998 if (complain & tf_error)
19000 if (type == error_mark_node)
19001 inform (input_location, "invalid template non-type parameter");
19003 error ("%q#T is not a valid type for a template non-type parameter",
19009 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
19010 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
19013 dependent_type_p_r (tree type)
19019 A type is dependent if it is:
19021 -- a template parameter. Template template parameters are types
19022 for us (since TYPE_P holds true for them) so we handle
19024 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
19025 || TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM)
19027 /* -- a qualified-id with a nested-name-specifier which contains a
19028 class-name that names a dependent type or whose unqualified-id
19029 names a dependent type. */
19030 if (TREE_CODE (type) == TYPENAME_TYPE)
19032 /* -- a cv-qualified type where the cv-unqualified type is
19034 type = TYPE_MAIN_VARIANT (type);
19035 /* -- a compound type constructed from any dependent type. */
19036 if (TYPE_PTR_TO_MEMBER_P (type))
19037 return (dependent_type_p (TYPE_PTRMEM_CLASS_TYPE (type))
19038 || dependent_type_p (TYPE_PTRMEM_POINTED_TO_TYPE
19040 else if (TREE_CODE (type) == POINTER_TYPE
19041 || TREE_CODE (type) == REFERENCE_TYPE)
19042 return dependent_type_p (TREE_TYPE (type));
19043 else if (TREE_CODE (type) == FUNCTION_TYPE
19044 || TREE_CODE (type) == METHOD_TYPE)
19048 if (dependent_type_p (TREE_TYPE (type)))
19050 for (arg_type = TYPE_ARG_TYPES (type);
19052 arg_type = TREE_CHAIN (arg_type))
19053 if (dependent_type_p (TREE_VALUE (arg_type)))
19057 /* -- an array type constructed from any dependent type or whose
19058 size is specified by a constant expression that is
19061 We checked for type- and value-dependence of the bounds in
19062 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
19063 if (TREE_CODE (type) == ARRAY_TYPE)
19065 if (TYPE_DOMAIN (type)
19066 && dependent_type_p (TYPE_DOMAIN (type)))
19068 return dependent_type_p (TREE_TYPE (type));
19071 /* -- a template-id in which either the template name is a template
19073 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
19075 /* ... or any of the template arguments is a dependent type or
19076 an expression that is type-dependent or value-dependent. */
19077 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INFO (type)
19078 && (any_dependent_template_arguments_p
19079 (INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type)))))
19082 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
19083 dependent; if the argument of the `typeof' expression is not
19084 type-dependent, then it should already been have resolved. */
19085 if (TREE_CODE (type) == TYPEOF_TYPE
19086 || TREE_CODE (type) == DECLTYPE_TYPE
19087 || TREE_CODE (type) == UNDERLYING_TYPE)
19090 /* A template argument pack is dependent if any of its packed
19092 if (TREE_CODE (type) == TYPE_ARGUMENT_PACK)
19094 tree args = ARGUMENT_PACK_ARGS (type);
19095 int i, len = TREE_VEC_LENGTH (args);
19096 for (i = 0; i < len; ++i)
19097 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
19101 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
19102 be template parameters. */
19103 if (TREE_CODE (type) == TYPE_PACK_EXPANSION)
19106 /* The standard does not specifically mention types that are local
19107 to template functions or local classes, but they should be
19108 considered dependent too. For example:
19110 template <int I> void f() {
19115 The size of `E' cannot be known until the value of `I' has been
19116 determined. Therefore, `E' must be considered dependent. */
19117 scope = TYPE_CONTEXT (type);
19118 if (scope && TYPE_P (scope))
19119 return dependent_type_p (scope);
19120 /* Don't use type_dependent_expression_p here, as it can lead
19121 to infinite recursion trying to determine whether a lambda
19122 nested in a lambda is dependent (c++/47687). */
19123 else if (scope && TREE_CODE (scope) == FUNCTION_DECL
19124 && DECL_LANG_SPECIFIC (scope)
19125 && DECL_TEMPLATE_INFO (scope)
19126 && (any_dependent_template_arguments_p
19127 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (scope)))))
19130 /* Other types are non-dependent. */
19134 /* Returns TRUE if TYPE is dependent, in the sense of
19135 [temp.dep.type]. Note that a NULL type is considered dependent. */
19138 dependent_type_p (tree type)
19140 /* If there are no template parameters in scope, then there can't be
19141 any dependent types. */
19142 if (!processing_template_decl)
19144 /* If we are not processing a template, then nobody should be
19145 providing us with a dependent type. */
19147 gcc_assert (TREE_CODE (type) != TEMPLATE_TYPE_PARM || is_auto (type));
19151 /* If the type is NULL, we have not computed a type for the entity
19152 in question; in that case, the type is dependent. */
19156 /* Erroneous types can be considered non-dependent. */
19157 if (type == error_mark_node)
19160 /* If we have not already computed the appropriate value for TYPE,
19162 if (!TYPE_DEPENDENT_P_VALID (type))
19164 TYPE_DEPENDENT_P (type) = dependent_type_p_r (type);
19165 TYPE_DEPENDENT_P_VALID (type) = 1;
19168 return TYPE_DEPENDENT_P (type);
19171 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
19172 lookup. In other words, a dependent type that is not the current
19176 dependent_scope_p (tree scope)
19178 return (scope && TYPE_P (scope) && dependent_type_p (scope)
19179 && !currently_open_class (scope));
19182 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
19183 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
19186 /* Note that this predicate is not appropriate for general expressions;
19187 only constant expressions (that satisfy potential_constant_expression)
19188 can be tested for value dependence.
19190 We should really also have a predicate for "instantiation-dependent".
19192 fold_non_dependent_expr: fold if constant and not type-dependent and not value-dependent.
19193 (what about instantiation-dependent constant-expressions?)
19194 is_late_template_attribute: defer if instantiation-dependent.
19195 compute_array_index_type: proceed if constant and not t- or v-dependent
19196 if instantiation-dependent, need to remember full expression
19197 uses_template_parms: FIXME - need to audit callers
19198 tsubst_decl [function_decl]: Why is this using value_dependent_expression_p?
19199 dependent_type_p [array_type]: dependent if index type is dependent
19201 static_assert - instantiation-dependent */
19204 value_dependent_expression_p (tree expression)
19206 if (!processing_template_decl)
19209 /* A name declared with a dependent type. */
19210 if (DECL_P (expression) && type_dependent_expression_p (expression))
19213 switch (TREE_CODE (expression))
19215 case IDENTIFIER_NODE:
19216 /* A name that has not been looked up -- must be dependent. */
19219 case TEMPLATE_PARM_INDEX:
19220 /* A non-type template parm. */
19224 /* A non-type template parm. */
19225 if (DECL_TEMPLATE_PARM_P (expression))
19227 return value_dependent_expression_p (DECL_INITIAL (expression));
19230 /* A constant with literal type and is initialized
19231 with an expression that is value-dependent. */
19232 if (DECL_INITIAL (expression)
19233 && decl_constant_var_p (expression)
19234 && value_dependent_expression_p (DECL_INITIAL (expression)))
19238 case DYNAMIC_CAST_EXPR:
19239 case STATIC_CAST_EXPR:
19240 case CONST_CAST_EXPR:
19241 case REINTERPRET_CAST_EXPR:
19243 /* These expressions are value-dependent if the type to which
19244 the cast occurs is dependent or the expression being casted
19245 is value-dependent. */
19247 tree type = TREE_TYPE (expression);
19249 if (dependent_type_p (type))
19252 /* A functional cast has a list of operands. */
19253 expression = TREE_OPERAND (expression, 0);
19256 /* If there are no operands, it must be an expression such
19257 as "int()". This should not happen for aggregate types
19258 because it would form non-constant expressions. */
19259 gcc_assert (cxx_dialect >= cxx0x
19260 || INTEGRAL_OR_ENUMERATION_TYPE_P (type));
19265 if (TREE_CODE (expression) == TREE_LIST)
19266 return any_value_dependent_elements_p (expression);
19268 return value_dependent_expression_p (expression);
19274 /* A `sizeof' expression is value-dependent if the operand is
19275 type-dependent or is a pack expansion. */
19276 expression = TREE_OPERAND (expression, 0);
19277 if (PACK_EXPANSION_P (expression))
19279 else if (TYPE_P (expression))
19280 return dependent_type_p (expression);
19281 return type_dependent_expression_p (expression);
19283 case AT_ENCODE_EXPR:
19284 /* An 'encode' expression is value-dependent if the operand is
19286 expression = TREE_OPERAND (expression, 0);
19287 return dependent_type_p (expression);
19289 case NOEXCEPT_EXPR:
19290 expression = TREE_OPERAND (expression, 0);
19291 return type_dependent_expression_p (expression);
19295 tree name = TREE_OPERAND (expression, 1);
19296 return value_dependent_expression_p (name);
19299 case COMPONENT_REF:
19300 return (value_dependent_expression_p (TREE_OPERAND (expression, 0))
19301 || value_dependent_expression_p (TREE_OPERAND (expression, 1)));
19303 case NONTYPE_ARGUMENT_PACK:
19304 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
19305 is value-dependent. */
19307 tree values = ARGUMENT_PACK_ARGS (expression);
19308 int i, len = TREE_VEC_LENGTH (values);
19310 for (i = 0; i < len; ++i)
19311 if (value_dependent_expression_p (TREE_VEC_ELT (values, i)))
19319 tree type2 = TRAIT_EXPR_TYPE2 (expression);
19320 return (dependent_type_p (TRAIT_EXPR_TYPE1 (expression))
19321 || (type2 ? dependent_type_p (type2) : false));
19325 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
19326 || (value_dependent_expression_p (TREE_OPERAND (expression, 2))));
19329 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
19330 || (value_dependent_expression_p (TREE_OPERAND (expression, 1))));
19334 tree op = TREE_OPERAND (expression, 0);
19335 return (value_dependent_expression_p (op)
19336 || has_value_dependent_address (op));
19341 tree fn = get_callee_fndecl (expression);
19343 if (!fn && value_dependent_expression_p (CALL_EXPR_FN (expression)))
19345 nargs = call_expr_nargs (expression);
19346 for (i = 0; i < nargs; ++i)
19348 tree op = CALL_EXPR_ARG (expression, i);
19349 /* In a call to a constexpr member function, look through the
19350 implicit ADDR_EXPR on the object argument so that it doesn't
19351 cause the call to be considered value-dependent. We also
19352 look through it in potential_constant_expression. */
19353 if (i == 0 && fn && DECL_DECLARED_CONSTEXPR_P (fn)
19354 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
19355 && TREE_CODE (op) == ADDR_EXPR)
19356 op = TREE_OPERAND (op, 0);
19357 if (value_dependent_expression_p (op))
19363 case TEMPLATE_ID_EXPR:
19364 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
19366 return type_dependent_expression_p (expression);
19372 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), ix, val)
19373 if (value_dependent_expression_p (val))
19379 /* A constant expression is value-dependent if any subexpression is
19380 value-dependent. */
19381 switch (TREE_CODE_CLASS (TREE_CODE (expression)))
19383 case tcc_reference:
19385 case tcc_comparison:
19387 case tcc_expression:
19390 int i, len = cp_tree_operand_length (expression);
19392 for (i = 0; i < len; i++)
19394 tree t = TREE_OPERAND (expression, i);
19396 /* In some cases, some of the operands may be missing.l
19397 (For example, in the case of PREDECREMENT_EXPR, the
19398 amount to increment by may be missing.) That doesn't
19399 make the expression dependent. */
19400 if (t && value_dependent_expression_p (t))
19411 /* The expression is not value-dependent. */
19415 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
19416 [temp.dep.expr]. Note that an expression with no type is
19417 considered dependent. Other parts of the compiler arrange for an
19418 expression with type-dependent subexpressions to have no type, so
19419 this function doesn't have to be fully recursive. */
19422 type_dependent_expression_p (tree expression)
19424 if (!processing_template_decl)
19427 if (expression == error_mark_node)
19430 /* An unresolved name is always dependent. */
19431 if (TREE_CODE (expression) == IDENTIFIER_NODE
19432 || TREE_CODE (expression) == USING_DECL)
19435 /* Some expression forms are never type-dependent. */
19436 if (TREE_CODE (expression) == PSEUDO_DTOR_EXPR
19437 || TREE_CODE (expression) == SIZEOF_EXPR
19438 || TREE_CODE (expression) == ALIGNOF_EXPR
19439 || TREE_CODE (expression) == AT_ENCODE_EXPR
19440 || TREE_CODE (expression) == NOEXCEPT_EXPR
19441 || TREE_CODE (expression) == TRAIT_EXPR
19442 || TREE_CODE (expression) == TYPEID_EXPR
19443 || TREE_CODE (expression) == DELETE_EXPR
19444 || TREE_CODE (expression) == VEC_DELETE_EXPR
19445 || TREE_CODE (expression) == THROW_EXPR)
19448 /* The types of these expressions depends only on the type to which
19449 the cast occurs. */
19450 if (TREE_CODE (expression) == DYNAMIC_CAST_EXPR
19451 || TREE_CODE (expression) == STATIC_CAST_EXPR
19452 || TREE_CODE (expression) == CONST_CAST_EXPR
19453 || TREE_CODE (expression) == REINTERPRET_CAST_EXPR
19454 || TREE_CODE (expression) == IMPLICIT_CONV_EXPR
19455 || TREE_CODE (expression) == CAST_EXPR)
19456 return dependent_type_p (TREE_TYPE (expression));
19458 /* The types of these expressions depends only on the type created
19459 by the expression. */
19460 if (TREE_CODE (expression) == NEW_EXPR
19461 || TREE_CODE (expression) == VEC_NEW_EXPR)
19463 /* For NEW_EXPR tree nodes created inside a template, either
19464 the object type itself or a TREE_LIST may appear as the
19466 tree type = TREE_OPERAND (expression, 1);
19467 if (TREE_CODE (type) == TREE_LIST)
19468 /* This is an array type. We need to check array dimensions
19470 return dependent_type_p (TREE_VALUE (TREE_PURPOSE (type)))
19471 || value_dependent_expression_p
19472 (TREE_OPERAND (TREE_VALUE (type), 1));
19474 return dependent_type_p (type);
19477 if (TREE_CODE (expression) == SCOPE_REF)
19479 tree scope = TREE_OPERAND (expression, 0);
19480 tree name = TREE_OPERAND (expression, 1);
19482 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
19483 contains an identifier associated by name lookup with one or more
19484 declarations declared with a dependent type, or...a
19485 nested-name-specifier or qualified-id that names a member of an
19486 unknown specialization. */
19487 return (type_dependent_expression_p (name)
19488 || dependent_scope_p (scope));
19491 if (TREE_CODE (expression) == FUNCTION_DECL
19492 && DECL_LANG_SPECIFIC (expression)
19493 && DECL_TEMPLATE_INFO (expression)
19494 && (any_dependent_template_arguments_p
19495 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (expression)))))
19498 if (TREE_CODE (expression) == TEMPLATE_DECL
19499 && !DECL_TEMPLATE_TEMPLATE_PARM_P (expression))
19502 if (TREE_CODE (expression) == STMT_EXPR)
19503 expression = stmt_expr_value_expr (expression);
19505 if (BRACE_ENCLOSED_INITIALIZER_P (expression))
19510 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), i, elt)
19512 if (type_dependent_expression_p (elt))
19518 /* A static data member of the current instantiation with incomplete
19519 array type is type-dependent, as the definition and specializations
19520 can have different bounds. */
19521 if (TREE_CODE (expression) == VAR_DECL
19522 && DECL_CLASS_SCOPE_P (expression)
19523 && dependent_type_p (DECL_CONTEXT (expression))
19524 && VAR_HAD_UNKNOWN_BOUND (expression))
19527 if (TREE_TYPE (expression) == unknown_type_node)
19529 if (TREE_CODE (expression) == ADDR_EXPR)
19530 return type_dependent_expression_p (TREE_OPERAND (expression, 0));
19531 if (TREE_CODE (expression) == COMPONENT_REF
19532 || TREE_CODE (expression) == OFFSET_REF)
19534 if (type_dependent_expression_p (TREE_OPERAND (expression, 0)))
19536 expression = TREE_OPERAND (expression, 1);
19537 if (TREE_CODE (expression) == IDENTIFIER_NODE)
19540 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
19541 if (TREE_CODE (expression) == SCOPE_REF)
19544 if (BASELINK_P (expression))
19545 expression = BASELINK_FUNCTIONS (expression);
19547 if (TREE_CODE (expression) == TEMPLATE_ID_EXPR)
19549 if (any_dependent_template_arguments_p
19550 (TREE_OPERAND (expression, 1)))
19552 expression = TREE_OPERAND (expression, 0);
19554 gcc_assert (TREE_CODE (expression) == OVERLOAD
19555 || TREE_CODE (expression) == FUNCTION_DECL);
19559 if (type_dependent_expression_p (OVL_CURRENT (expression)))
19561 expression = OVL_NEXT (expression);
19566 gcc_assert (TREE_CODE (expression) != TYPE_DECL);
19568 return (dependent_type_p (TREE_TYPE (expression)));
19571 /* Like type_dependent_expression_p, but it also works while not processing
19572 a template definition, i.e. during substitution or mangling. */
19575 type_dependent_expression_p_push (tree expr)
19578 ++processing_template_decl;
19579 b = type_dependent_expression_p (expr);
19580 --processing_template_decl;
19584 /* Returns TRUE if ARGS contains a type-dependent expression. */
19587 any_type_dependent_arguments_p (const VEC(tree,gc) *args)
19592 FOR_EACH_VEC_ELT (tree, args, i, arg)
19594 if (type_dependent_expression_p (arg))
19600 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
19601 expressions) contains any type-dependent expressions. */
19604 any_type_dependent_elements_p (const_tree list)
19606 for (; list; list = TREE_CHAIN (list))
19607 if (value_dependent_expression_p (TREE_VALUE (list)))
19613 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
19614 expressions) contains any value-dependent expressions. */
19617 any_value_dependent_elements_p (const_tree list)
19619 for (; list; list = TREE_CHAIN (list))
19620 if (value_dependent_expression_p (TREE_VALUE (list)))
19626 /* Returns TRUE if the ARG (a template argument) is dependent. */
19629 dependent_template_arg_p (tree arg)
19631 if (!processing_template_decl)
19634 /* Assume a template argument that was wrongly written by the user
19635 is dependent. This is consistent with what
19636 any_dependent_template_arguments_p [that calls this function]
19638 if (!arg || arg == error_mark_node)
19641 if (TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
19642 arg = ARGUMENT_PACK_SELECT_ARG (arg);
19644 if (TREE_CODE (arg) == TEMPLATE_DECL
19645 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
19646 return dependent_template_p (arg);
19647 else if (ARGUMENT_PACK_P (arg))
19649 tree args = ARGUMENT_PACK_ARGS (arg);
19650 int i, len = TREE_VEC_LENGTH (args);
19651 for (i = 0; i < len; ++i)
19653 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
19659 else if (TYPE_P (arg))
19660 return dependent_type_p (arg);
19662 return (type_dependent_expression_p (arg)
19663 || value_dependent_expression_p (arg));
19666 /* Returns true if ARGS (a collection of template arguments) contains
19667 any types that require structural equality testing. */
19670 any_template_arguments_need_structural_equality_p (tree args)
19677 if (args == error_mark_node)
19680 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
19682 tree level = TMPL_ARGS_LEVEL (args, i + 1);
19683 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
19685 tree arg = TREE_VEC_ELT (level, j);
19686 tree packed_args = NULL_TREE;
19689 if (ARGUMENT_PACK_P (arg))
19691 /* Look inside the argument pack. */
19692 packed_args = ARGUMENT_PACK_ARGS (arg);
19693 len = TREE_VEC_LENGTH (packed_args);
19696 for (k = 0; k < len; ++k)
19699 arg = TREE_VEC_ELT (packed_args, k);
19701 if (error_operand_p (arg))
19703 else if (TREE_CODE (arg) == TEMPLATE_DECL
19704 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
19706 else if (TYPE_P (arg) && TYPE_STRUCTURAL_EQUALITY_P (arg))
19708 else if (!TYPE_P (arg) && TREE_TYPE (arg)
19709 && TYPE_STRUCTURAL_EQUALITY_P (TREE_TYPE (arg)))
19718 /* Returns true if ARGS (a collection of template arguments) contains
19719 any dependent arguments. */
19722 any_dependent_template_arguments_p (const_tree args)
19729 if (args == error_mark_node)
19732 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
19734 const_tree level = TMPL_ARGS_LEVEL (args, i + 1);
19735 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
19736 if (dependent_template_arg_p (TREE_VEC_ELT (level, j)))
19743 /* Returns TRUE if the template TMPL is dependent. */
19746 dependent_template_p (tree tmpl)
19748 if (TREE_CODE (tmpl) == OVERLOAD)
19752 if (dependent_template_p (OVL_CURRENT (tmpl)))
19754 tmpl = OVL_NEXT (tmpl);
19759 /* Template template parameters are dependent. */
19760 if (DECL_TEMPLATE_TEMPLATE_PARM_P (tmpl)
19761 || TREE_CODE (tmpl) == TEMPLATE_TEMPLATE_PARM)
19763 /* So are names that have not been looked up. */
19764 if (TREE_CODE (tmpl) == SCOPE_REF
19765 || TREE_CODE (tmpl) == IDENTIFIER_NODE)
19767 /* So are member templates of dependent classes. */
19768 if (TYPE_P (CP_DECL_CONTEXT (tmpl)))
19769 return dependent_type_p (DECL_CONTEXT (tmpl));
19773 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
19776 dependent_template_id_p (tree tmpl, tree args)
19778 return (dependent_template_p (tmpl)
19779 || any_dependent_template_arguments_p (args));
19782 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
19786 dependent_omp_for_p (tree declv, tree initv, tree condv, tree incrv)
19790 if (!processing_template_decl)
19793 for (i = 0; i < TREE_VEC_LENGTH (declv); i++)
19795 tree decl = TREE_VEC_ELT (declv, i);
19796 tree init = TREE_VEC_ELT (initv, i);
19797 tree cond = TREE_VEC_ELT (condv, i);
19798 tree incr = TREE_VEC_ELT (incrv, i);
19800 if (type_dependent_expression_p (decl))
19803 if (init && type_dependent_expression_p (init))
19806 if (type_dependent_expression_p (cond))
19809 if (COMPARISON_CLASS_P (cond)
19810 && (type_dependent_expression_p (TREE_OPERAND (cond, 0))
19811 || type_dependent_expression_p (TREE_OPERAND (cond, 1))))
19814 if (TREE_CODE (incr) == MODOP_EXPR)
19816 if (type_dependent_expression_p (TREE_OPERAND (incr, 0))
19817 || type_dependent_expression_p (TREE_OPERAND (incr, 2)))
19820 else if (type_dependent_expression_p (incr))
19822 else if (TREE_CODE (incr) == MODIFY_EXPR)
19824 if (type_dependent_expression_p (TREE_OPERAND (incr, 0)))
19826 else if (BINARY_CLASS_P (TREE_OPERAND (incr, 1)))
19828 tree t = TREE_OPERAND (incr, 1);
19829 if (type_dependent_expression_p (TREE_OPERAND (t, 0))
19830 || type_dependent_expression_p (TREE_OPERAND (t, 1)))
19839 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
19840 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
19841 no such TYPE can be found. Note that this function peers inside
19842 uninstantiated templates and therefore should be used only in
19843 extremely limited situations. ONLY_CURRENT_P restricts this
19844 peering to the currently open classes hierarchy (which is required
19845 when comparing types). */
19848 resolve_typename_type (tree type, bool only_current_p)
19857 gcc_assert (TREE_CODE (type) == TYPENAME_TYPE);
19859 scope = TYPE_CONTEXT (type);
19860 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
19861 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
19862 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
19863 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
19864 identifier of the TYPENAME_TYPE anymore.
19865 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
19866 TYPENAME_TYPE instead, we avoid messing up with a possible
19867 typedef variant case. */
19868 name = TYPE_IDENTIFIER (TYPE_MAIN_VARIANT (type));
19870 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
19871 it first before we can figure out what NAME refers to. */
19872 if (TREE_CODE (scope) == TYPENAME_TYPE)
19873 scope = resolve_typename_type (scope, only_current_p);
19874 /* If we don't know what SCOPE refers to, then we cannot resolve the
19876 if (TREE_CODE (scope) == TYPENAME_TYPE)
19878 /* If the SCOPE is a template type parameter, we have no way of
19879 resolving the name. */
19880 if (TREE_CODE (scope) == TEMPLATE_TYPE_PARM)
19882 /* If the SCOPE is not the current instantiation, there's no reason
19883 to look inside it. */
19884 if (only_current_p && !currently_open_class (scope))
19886 /* If this is a typedef, we don't want to look inside (c++/11987). */
19887 if (typedef_variant_p (type))
19889 /* If SCOPE isn't the template itself, it will not have a valid
19890 TYPE_FIELDS list. */
19891 if (same_type_p (scope, CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope)))
19892 /* scope is either the template itself or a compatible instantiation
19893 like X<T>, so look up the name in the original template. */
19894 scope = CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope);
19896 /* scope is a partial instantiation, so we can't do the lookup or we
19897 will lose the template arguments. */
19899 /* Enter the SCOPE so that name lookup will be resolved as if we
19900 were in the class definition. In particular, SCOPE will no
19901 longer be considered a dependent type. */
19902 pushed_scope = push_scope (scope);
19903 /* Look up the declaration. */
19904 decl = lookup_member (scope, name, /*protect=*/0, /*want_type=*/true,
19905 tf_warning_or_error);
19907 result = NULL_TREE;
19909 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
19910 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
19913 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == IDENTIFIER_NODE
19914 && TREE_CODE (decl) == TYPE_DECL)
19916 result = TREE_TYPE (decl);
19917 if (result == error_mark_node)
19918 result = NULL_TREE;
19920 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == TEMPLATE_ID_EXPR
19921 && DECL_CLASS_TEMPLATE_P (decl))
19925 /* Obtain the template and the arguments. */
19926 tmpl = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 0);
19927 args = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 1);
19928 /* Instantiate the template. */
19929 result = lookup_template_class (tmpl, args, NULL_TREE, NULL_TREE,
19930 /*entering_scope=*/0,
19931 tf_error | tf_user);
19932 if (result == error_mark_node)
19933 result = NULL_TREE;
19936 /* Leave the SCOPE. */
19938 pop_scope (pushed_scope);
19940 /* If we failed to resolve it, return the original typename. */
19944 /* If lookup found a typename type, resolve that too. */
19945 if (TREE_CODE (result) == TYPENAME_TYPE && !TYPENAME_IS_RESOLVING_P (result))
19947 /* Ill-formed programs can cause infinite recursion here, so we
19948 must catch that. */
19949 TYPENAME_IS_RESOLVING_P (type) = 1;
19950 result = resolve_typename_type (result, only_current_p);
19951 TYPENAME_IS_RESOLVING_P (type) = 0;
19954 /* Qualify the resulting type. */
19955 quals = cp_type_quals (type);
19957 result = cp_build_qualified_type (result, cp_type_quals (result) | quals);
19962 /* EXPR is an expression which is not type-dependent. Return a proxy
19963 for EXPR that can be used to compute the types of larger
19964 expressions containing EXPR. */
19967 build_non_dependent_expr (tree expr)
19971 #ifdef ENABLE_CHECKING
19972 /* Try to get a constant value for all non-type-dependent expressions in
19973 order to expose bugs in *_dependent_expression_p and constexpr. */
19974 if (cxx_dialect >= cxx0x)
19975 maybe_constant_value (fold_non_dependent_expr_sfinae (expr, tf_none));
19978 /* Preserve OVERLOADs; the functions must be available to resolve
19981 if (TREE_CODE (inner_expr) == STMT_EXPR)
19982 inner_expr = stmt_expr_value_expr (inner_expr);
19983 if (TREE_CODE (inner_expr) == ADDR_EXPR)
19984 inner_expr = TREE_OPERAND (inner_expr, 0);
19985 if (TREE_CODE (inner_expr) == COMPONENT_REF)
19986 inner_expr = TREE_OPERAND (inner_expr, 1);
19987 if (is_overloaded_fn (inner_expr)
19988 || TREE_CODE (inner_expr) == OFFSET_REF)
19990 /* There is no need to return a proxy for a variable. */
19991 if (TREE_CODE (expr) == VAR_DECL)
19993 /* Preserve string constants; conversions from string constants to
19994 "char *" are allowed, even though normally a "const char *"
19995 cannot be used to initialize a "char *". */
19996 if (TREE_CODE (expr) == STRING_CST)
19998 /* Preserve arithmetic constants, as an optimization -- there is no
19999 reason to create a new node. */
20000 if (TREE_CODE (expr) == INTEGER_CST || TREE_CODE (expr) == REAL_CST)
20002 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
20003 There is at least one place where we want to know that a
20004 particular expression is a throw-expression: when checking a ?:
20005 expression, there are special rules if the second or third
20006 argument is a throw-expression. */
20007 if (TREE_CODE (expr) == THROW_EXPR)
20010 /* Don't wrap an initializer list, we need to be able to look inside. */
20011 if (BRACE_ENCLOSED_INITIALIZER_P (expr))
20014 if (TREE_CODE (expr) == COND_EXPR)
20015 return build3 (COND_EXPR,
20017 TREE_OPERAND (expr, 0),
20018 (TREE_OPERAND (expr, 1)
20019 ? build_non_dependent_expr (TREE_OPERAND (expr, 1))
20020 : build_non_dependent_expr (TREE_OPERAND (expr, 0))),
20021 build_non_dependent_expr (TREE_OPERAND (expr, 2)));
20022 if (TREE_CODE (expr) == COMPOUND_EXPR
20023 && !COMPOUND_EXPR_OVERLOADED (expr))
20024 return build2 (COMPOUND_EXPR,
20026 TREE_OPERAND (expr, 0),
20027 build_non_dependent_expr (TREE_OPERAND (expr, 1)));
20029 /* If the type is unknown, it can't really be non-dependent */
20030 gcc_assert (TREE_TYPE (expr) != unknown_type_node);
20032 /* Otherwise, build a NON_DEPENDENT_EXPR. */
20033 return build1 (NON_DEPENDENT_EXPR, TREE_TYPE (expr), expr);
20036 /* ARGS is a vector of expressions as arguments to a function call.
20037 Replace the arguments with equivalent non-dependent expressions.
20038 This modifies ARGS in place. */
20041 make_args_non_dependent (VEC(tree,gc) *args)
20046 FOR_EACH_VEC_ELT (tree, args, ix, arg)
20048 tree newarg = build_non_dependent_expr (arg);
20050 VEC_replace (tree, args, ix, newarg);
20054 /* Returns a type which represents 'auto'. We use a TEMPLATE_TYPE_PARM
20055 with a level one deeper than the actual template parms. */
20060 tree au = cxx_make_type (TEMPLATE_TYPE_PARM);
20061 TYPE_NAME (au) = build_decl (BUILTINS_LOCATION,
20062 TYPE_DECL, get_identifier ("auto"), au);
20063 TYPE_STUB_DECL (au) = TYPE_NAME (au);
20064 TEMPLATE_TYPE_PARM_INDEX (au) = build_template_parm_index
20065 (0, processing_template_decl + 1, processing_template_decl + 1,
20066 0, TYPE_NAME (au), NULL_TREE);
20067 TYPE_CANONICAL (au) = canonical_type_parameter (au);
20068 DECL_ARTIFICIAL (TYPE_NAME (au)) = 1;
20069 SET_DECL_TEMPLATE_PARM_P (TYPE_NAME (au));
20074 /* Given type ARG, return std::initializer_list<ARG>. */
20079 tree std_init_list = namespace_binding
20080 (get_identifier ("initializer_list"), std_node);
20082 if (!std_init_list || !DECL_CLASS_TEMPLATE_P (std_init_list))
20084 error ("deducing from brace-enclosed initializer list requires "
20085 "#include <initializer_list>");
20086 return error_mark_node;
20088 argvec = make_tree_vec (1);
20089 TREE_VEC_ELT (argvec, 0) = arg;
20090 return lookup_template_class (std_init_list, argvec, NULL_TREE,
20091 NULL_TREE, 0, tf_warning_or_error);
20094 /* Replace auto in TYPE with std::initializer_list<auto>. */
20097 listify_autos (tree type, tree auto_node)
20099 tree init_auto = listify (auto_node);
20100 tree argvec = make_tree_vec (1);
20101 TREE_VEC_ELT (argvec, 0) = init_auto;
20102 if (processing_template_decl)
20103 argvec = add_to_template_args (current_template_args (), argvec);
20104 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
20107 /* walk_tree helper for do_auto_deduction. */
20110 contains_auto_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
20113 /* Is this a variable with the type we're looking for? */
20115 && TREE_TYPE (*tp) == type)
20121 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
20122 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
20125 do_auto_deduction (tree type, tree init, tree auto_node)
20127 tree parms, tparms, targs;
20132 if (processing_template_decl
20133 && (TREE_TYPE (init) == NULL_TREE
20134 || BRACE_ENCLOSED_INITIALIZER_P (init)))
20135 /* Not enough information to try this yet. */
20138 /* The name of the object being declared shall not appear in the
20139 initializer expression. */
20140 decl = cp_walk_tree_without_duplicates (&init, contains_auto_r, type);
20143 error ("variable %q#D with %<auto%> type used in its own "
20144 "initializer", decl);
20145 return error_mark_node;
20148 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
20149 with either a new invented type template parameter U or, if the
20150 initializer is a braced-init-list (8.5.4), with
20151 std::initializer_list<U>. */
20152 if (BRACE_ENCLOSED_INITIALIZER_P (init))
20153 type = listify_autos (type, auto_node);
20155 init = resolve_nondeduced_context (init);
20157 parms = build_tree_list (NULL_TREE, type);
20159 tparms = make_tree_vec (1);
20160 targs = make_tree_vec (1);
20161 TREE_VEC_ELT (tparms, 0)
20162 = build_tree_list (NULL_TREE, TYPE_NAME (auto_node));
20163 val = type_unification_real (tparms, targs, parms, args, 1, 0,
20164 DEDUCE_CALL, LOOKUP_NORMAL,
20165 /*explain_p=*/false);
20168 if (processing_template_decl)
20169 /* Try again at instantiation time. */
20171 if (type && type != error_mark_node)
20172 /* If type is error_mark_node a diagnostic must have been
20173 emitted by now. Also, having a mention to '<type error>'
20174 in the diagnostic is not really useful to the user. */
20175 error ("unable to deduce %qT from %qE", type, init);
20176 return error_mark_node;
20179 /* If the list of declarators contains more than one declarator, the type
20180 of each declared variable is determined as described above. If the
20181 type deduced for the template parameter U is not the same in each
20182 deduction, the program is ill-formed. */
20183 if (TREE_TYPE (auto_node)
20184 && !same_type_p (TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0)))
20186 error ("inconsistent deduction for %qT: %qT and then %qT",
20187 auto_node, TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0));
20188 return error_mark_node;
20190 TREE_TYPE (auto_node) = TREE_VEC_ELT (targs, 0);
20192 if (processing_template_decl)
20193 targs = add_to_template_args (current_template_args (), targs);
20194 return tsubst (type, targs, tf_warning_or_error, NULL_TREE);
20197 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
20201 splice_late_return_type (tree type, tree late_return_type)
20205 if (late_return_type == NULL_TREE)
20207 argvec = make_tree_vec (1);
20208 TREE_VEC_ELT (argvec, 0) = late_return_type;
20209 if (processing_template_parmlist)
20210 /* For a late-specified return type in a template type-parameter, we
20211 need to add a dummy argument level for its parmlist. */
20212 argvec = add_to_template_args
20213 (make_tree_vec (processing_template_parmlist), argvec);
20214 if (current_template_parms)
20215 argvec = add_to_template_args (current_template_args (), argvec);
20216 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
20219 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto'. */
20222 is_auto (const_tree type)
20224 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
20225 && TYPE_IDENTIFIER (type) == get_identifier ("auto"))
20231 /* Returns true iff TYPE contains a use of 'auto'. Since auto can only
20232 appear as a type-specifier for the declaration in question, we don't
20233 have to look through the whole type. */
20236 type_uses_auto (tree type)
20238 enum tree_code code;
20239 if (is_auto (type))
20242 code = TREE_CODE (type);
20244 if (code == POINTER_TYPE || code == REFERENCE_TYPE
20245 || code == OFFSET_TYPE || code == FUNCTION_TYPE
20246 || code == METHOD_TYPE || code == ARRAY_TYPE)
20247 return type_uses_auto (TREE_TYPE (type));
20249 if (TYPE_PTRMEMFUNC_P (type))
20250 return type_uses_auto (TREE_TYPE (TREE_TYPE
20251 (TYPE_PTRMEMFUNC_FN_TYPE (type))));
20256 /* For a given template T, return the vector of typedefs referenced
20257 in T for which access check is needed at T instantiation time.
20258 T is either a FUNCTION_DECL or a RECORD_TYPE.
20259 Those typedefs were added to T by the function
20260 append_type_to_template_for_access_check. */
20262 VEC(qualified_typedef_usage_t,gc)*
20263 get_types_needing_access_check (tree t)
20266 VEC(qualified_typedef_usage_t,gc) *result = NULL;
20268 if (!t || t == error_mark_node)
20271 if (!(ti = get_template_info (t)))
20274 if (CLASS_TYPE_P (t)
20275 || TREE_CODE (t) == FUNCTION_DECL)
20277 if (!TI_TEMPLATE (ti))
20280 result = TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti);
20286 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
20287 tied to T. That list of typedefs will be access checked at
20288 T instantiation time.
20289 T is either a FUNCTION_DECL or a RECORD_TYPE.
20290 TYPE_DECL is a TYPE_DECL node representing a typedef.
20291 SCOPE is the scope through which TYPE_DECL is accessed.
20292 LOCATION is the location of the usage point of TYPE_DECL.
20294 This function is a subroutine of
20295 append_type_to_template_for_access_check. */
20298 append_type_to_template_for_access_check_1 (tree t,
20301 location_t location)
20303 qualified_typedef_usage_t typedef_usage;
20306 if (!t || t == error_mark_node)
20309 gcc_assert ((TREE_CODE (t) == FUNCTION_DECL
20310 || CLASS_TYPE_P (t))
20312 && TREE_CODE (type_decl) == TYPE_DECL
20315 if (!(ti = get_template_info (t)))
20318 gcc_assert (TI_TEMPLATE (ti));
20320 typedef_usage.typedef_decl = type_decl;
20321 typedef_usage.context = scope;
20322 typedef_usage.locus = location;
20324 VEC_safe_push (qualified_typedef_usage_t, gc,
20325 TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti),
20329 /* Append TYPE_DECL to the template TEMPL.
20330 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
20331 At TEMPL instanciation time, TYPE_DECL will be checked to see
20332 if it can be accessed through SCOPE.
20333 LOCATION is the location of the usage point of TYPE_DECL.
20335 e.g. consider the following code snippet:
20342 template<class U> struct S
20344 C::myint mi; // <-- usage point of the typedef C::myint
20349 At S<char> instantiation time, we need to check the access of C::myint
20350 In other words, we need to check the access of the myint typedef through
20351 the C scope. For that purpose, this function will add the myint typedef
20352 and the scope C through which its being accessed to a list of typedefs
20353 tied to the template S. That list will be walked at template instantiation
20354 time and access check performed on each typedefs it contains.
20355 Note that this particular code snippet should yield an error because
20356 myint is private to C. */
20359 append_type_to_template_for_access_check (tree templ,
20362 location_t location)
20364 qualified_typedef_usage_t *iter;
20367 gcc_assert (type_decl && (TREE_CODE (type_decl) == TYPE_DECL));
20369 /* Make sure we don't append the type to the template twice. */
20370 FOR_EACH_VEC_ELT (qualified_typedef_usage_t,
20371 get_types_needing_access_check (templ),
20373 if (iter->typedef_decl == type_decl && scope == iter->context)
20376 append_type_to_template_for_access_check_1 (templ, type_decl,
20380 /* Set up the hash tables for template instantiations. */
20383 init_template_processing (void)
20385 decl_specializations = htab_create_ggc (37,
20386 hash_specialization,
20387 eq_specializations,
20389 type_specializations = htab_create_ggc (37,
20390 hash_specialization,
20391 eq_specializations,
20395 /* Print stats about the template hash tables for -fstats. */
20398 print_template_statistics (void)
20400 fprintf (stderr, "decl_specializations: size %ld, %ld elements, "
20401 "%f collisions\n", (long) htab_size (decl_specializations),
20402 (long) htab_elements (decl_specializations),
20403 htab_collisions (decl_specializations));
20404 fprintf (stderr, "type_specializations: size %ld, %ld elements, "
20405 "%f collisions\n", (long) htab_size (type_specializations),
20406 (long) htab_elements (type_specializations),
20407 htab_collisions (type_specializations));
20410 #include "gt-cp-pt.h"