1 /* Handle parameterized types (templates) for GNU C++.
2 Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
3 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010, 2011, 2012
4 Free Software Foundation, Inc.
5 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
6 Rewritten by Jason Merrill (jason@cygnus.com).
8 This file is part of GCC.
10 GCC is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3, or (at your option)
15 GCC is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with GCC; see the file COPYING3. If not see
22 <http://www.gnu.org/licenses/>. */
24 /* Known bugs or deficiencies include:
26 all methods must be provided in header files; can't use a source
27 file that contains only the method templates and "just win". */
31 #include "coretypes.h"
35 #include "pointer-set.h"
38 #include "c-family/c-common.h"
39 #include "c-family/c-objc.h"
40 #include "cp-objcp-common.h"
41 #include "tree-inline.h"
46 #include "tree-iterator.h"
49 /* The type of functions taking a tree, and some additional data, and
51 typedef int (*tree_fn_t) (tree, void*);
53 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
54 instantiations have been deferred, either because their definitions
55 were not yet available, or because we were putting off doing the work. */
56 struct GTY ((chain_next ("%h.next"))) pending_template {
57 struct pending_template *next;
58 struct tinst_level *tinst;
61 static GTY(()) struct pending_template *pending_templates;
62 static GTY(()) struct pending_template *last_pending_template;
64 int processing_template_parmlist;
65 static int template_header_count;
67 static GTY(()) tree saved_trees;
68 static VEC(int,heap) *inline_parm_levels;
70 static GTY(()) struct tinst_level *current_tinst_level;
72 static GTY(()) tree saved_access_scope;
74 /* Live only within one (recursive) call to tsubst_expr. We use
75 this to pass the statement expression node from the STMT_EXPR
76 to the EXPR_STMT that is its result. */
77 static tree cur_stmt_expr;
79 /* A map from local variable declarations in the body of the template
80 presently being instantiated to the corresponding instantiated
82 static htab_t local_specializations;
84 typedef struct GTY(()) spec_entry
91 static GTY ((param_is (spec_entry)))
92 htab_t decl_specializations;
94 static GTY ((param_is (spec_entry)))
95 htab_t type_specializations;
97 /* Contains canonical template parameter types. The vector is indexed by
98 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
99 TREE_LIST, whose TREE_VALUEs contain the canonical template
100 parameters of various types and levels. */
101 static GTY(()) VEC(tree,gc) *canonical_template_parms;
103 #define UNIFY_ALLOW_NONE 0
104 #define UNIFY_ALLOW_MORE_CV_QUAL 1
105 #define UNIFY_ALLOW_LESS_CV_QUAL 2
106 #define UNIFY_ALLOW_DERIVED 4
107 #define UNIFY_ALLOW_INTEGER 8
108 #define UNIFY_ALLOW_OUTER_LEVEL 16
109 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
110 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
112 enum template_base_result {
114 tbr_ambiguous_baseclass,
118 static void push_access_scope (tree);
119 static void pop_access_scope (tree);
120 static void push_deduction_access_scope (tree);
121 static void pop_deduction_access_scope (tree);
122 static bool resolve_overloaded_unification (tree, tree, tree, tree,
123 unification_kind_t, int,
125 static int try_one_overload (tree, tree, tree, tree, tree,
126 unification_kind_t, int, bool, bool);
127 static int unify (tree, tree, tree, tree, int, bool);
128 static void add_pending_template (tree);
129 static tree reopen_tinst_level (struct tinst_level *);
130 static tree tsubst_initializer_list (tree, tree);
131 static tree get_class_bindings (tree, tree, tree);
132 static tree coerce_template_parms (tree, tree, tree, tsubst_flags_t,
134 static void tsubst_enum (tree, tree, tree);
135 static tree add_to_template_args (tree, tree);
136 static tree add_outermost_template_args (tree, tree);
137 static bool check_instantiated_args (tree, tree, tsubst_flags_t);
138 static int maybe_adjust_types_for_deduction (unification_kind_t, tree*, tree*,
140 static int type_unification_real (tree, tree, tree, const tree *,
141 unsigned int, int, unification_kind_t, int,
143 static void note_template_header (int);
144 static tree convert_nontype_argument_function (tree, tree);
145 static tree convert_nontype_argument (tree, tree, tsubst_flags_t);
146 static tree convert_template_argument (tree, tree, tree,
147 tsubst_flags_t, int, tree);
148 static int for_each_template_parm (tree, tree_fn_t, void*,
149 struct pointer_set_t*, bool);
150 static tree expand_template_argument_pack (tree);
151 static tree build_template_parm_index (int, int, int, int, tree, tree);
152 static bool inline_needs_template_parms (tree);
153 static void push_inline_template_parms_recursive (tree, int);
154 static tree retrieve_local_specialization (tree);
155 static void register_local_specialization (tree, tree);
156 static hashval_t hash_specialization (const void *p);
157 static tree reduce_template_parm_level (tree, tree, int, tree, tsubst_flags_t);
158 static int mark_template_parm (tree, void *);
159 static int template_parm_this_level_p (tree, void *);
160 static tree tsubst_friend_function (tree, tree);
161 static tree tsubst_friend_class (tree, tree);
162 static int can_complete_type_without_circularity (tree);
163 static tree get_bindings (tree, tree, tree, bool);
164 static int template_decl_level (tree);
165 static int check_cv_quals_for_unify (int, tree, tree);
166 static void template_parm_level_and_index (tree, int*, int*);
167 static int unify_pack_expansion (tree, tree, tree,
168 tree, unification_kind_t, bool, bool);
169 static tree tsubst_template_arg (tree, tree, tsubst_flags_t, tree);
170 static tree tsubst_template_args (tree, tree, tsubst_flags_t, tree);
171 static tree tsubst_template_parms (tree, tree, tsubst_flags_t);
172 static void regenerate_decl_from_template (tree, tree);
173 static tree most_specialized_class (tree, tree, tsubst_flags_t);
174 static tree tsubst_aggr_type (tree, tree, tsubst_flags_t, tree, int);
175 static tree tsubst_arg_types (tree, tree, tsubst_flags_t, tree);
176 static tree tsubst_function_type (tree, tree, tsubst_flags_t, tree);
177 static bool check_specialization_scope (void);
178 static tree process_partial_specialization (tree);
179 static void set_current_access_from_decl (tree);
180 static enum template_base_result get_template_base (tree, tree, tree, tree,
182 static tree try_class_unification (tree, tree, tree, tree, bool);
183 static int coerce_template_template_parms (tree, tree, tsubst_flags_t,
185 static bool template_template_parm_bindings_ok_p (tree, tree);
186 static int template_args_equal (tree, tree);
187 static void tsubst_default_arguments (tree);
188 static tree for_each_template_parm_r (tree *, int *, void *);
189 static tree copy_default_args_to_explicit_spec_1 (tree, tree);
190 static void copy_default_args_to_explicit_spec (tree);
191 static int invalid_nontype_parm_type_p (tree, tsubst_flags_t);
192 static int eq_local_specializations (const void *, const void *);
193 static bool dependent_template_arg_p (tree);
194 static bool any_template_arguments_need_structural_equality_p (tree);
195 static bool dependent_type_p_r (tree);
196 static tree tsubst_expr (tree, tree, tsubst_flags_t, tree, bool);
197 static tree tsubst_copy (tree, tree, tsubst_flags_t, tree);
198 static tree tsubst_pack_expansion (tree, tree, tsubst_flags_t, tree);
199 static tree tsubst_decl (tree, tree, tsubst_flags_t);
200 static void perform_typedefs_access_check (tree tmpl, tree targs);
201 static void append_type_to_template_for_access_check_1 (tree, tree, tree,
203 static tree listify (tree);
204 static tree listify_autos (tree, tree);
205 static tree template_parm_to_arg (tree t);
206 static bool arg_from_parm_pack_p (tree, tree);
207 static tree current_template_args (void);
208 static tree fixup_template_type_parm_type (tree, int);
209 static tree fixup_template_parm_index (tree, tree, int);
210 static tree tsubst_template_parm (tree, tree, tsubst_flags_t);
212 /* Make the current scope suitable for access checking when we are
213 processing T. T can be FUNCTION_DECL for instantiated function
214 template, or VAR_DECL for static member variable (need by
215 instantiate_decl). */
218 push_access_scope (tree t)
220 gcc_assert (TREE_CODE (t) == FUNCTION_DECL
221 || TREE_CODE (t) == VAR_DECL);
223 if (DECL_FRIEND_CONTEXT (t))
224 push_nested_class (DECL_FRIEND_CONTEXT (t));
225 else if (DECL_CLASS_SCOPE_P (t))
226 push_nested_class (DECL_CONTEXT (t));
228 push_to_top_level ();
230 if (TREE_CODE (t) == FUNCTION_DECL)
232 saved_access_scope = tree_cons
233 (NULL_TREE, current_function_decl, saved_access_scope);
234 current_function_decl = t;
238 /* Restore the scope set up by push_access_scope. T is the node we
242 pop_access_scope (tree t)
244 if (TREE_CODE (t) == FUNCTION_DECL)
246 current_function_decl = TREE_VALUE (saved_access_scope);
247 saved_access_scope = TREE_CHAIN (saved_access_scope);
250 if (DECL_FRIEND_CONTEXT (t) || DECL_CLASS_SCOPE_P (t))
253 pop_from_top_level ();
256 /* Do any processing required when DECL (a member template
257 declaration) is finished. Returns the TEMPLATE_DECL corresponding
258 to DECL, unless it is a specialization, in which case the DECL
259 itself is returned. */
262 finish_member_template_decl (tree decl)
264 if (decl == error_mark_node)
265 return error_mark_node;
267 gcc_assert (DECL_P (decl));
269 if (TREE_CODE (decl) == TYPE_DECL)
273 type = TREE_TYPE (decl);
274 if (type == error_mark_node)
275 return error_mark_node;
276 if (MAYBE_CLASS_TYPE_P (type)
277 && CLASSTYPE_TEMPLATE_INFO (type)
278 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
280 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
281 check_member_template (tmpl);
286 else if (TREE_CODE (decl) == FIELD_DECL)
287 error ("data member %qD cannot be a member template", decl);
288 else if (DECL_TEMPLATE_INFO (decl))
290 if (!DECL_TEMPLATE_SPECIALIZATION (decl))
292 check_member_template (DECL_TI_TEMPLATE (decl));
293 return DECL_TI_TEMPLATE (decl);
299 error ("invalid member template declaration %qD", decl);
301 return error_mark_node;
304 /* Create a template info node. */
307 build_template_info (tree template_decl, tree template_args)
309 tree result = make_node (TEMPLATE_INFO);
310 TI_TEMPLATE (result) = template_decl;
311 TI_ARGS (result) = template_args;
315 /* Return the template info node corresponding to T, whatever T is. */
318 get_template_info (const_tree t)
320 tree tinfo = NULL_TREE;
322 if (!t || t == error_mark_node)
325 if (DECL_P (t) && DECL_LANG_SPECIFIC (t))
326 tinfo = DECL_TEMPLATE_INFO (t);
328 if (!tinfo && DECL_IMPLICIT_TYPEDEF_P (t))
331 if (TAGGED_TYPE_P (t))
332 tinfo = TYPE_TEMPLATE_INFO (t);
333 else if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
334 tinfo = TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (t);
339 /* Returns the template nesting level of the indicated class TYPE.
349 A<T>::B<U> has depth two, while A<T> has depth one.
350 Both A<T>::B<int> and A<int>::B<U> have depth one, if
351 they are instantiations, not specializations.
353 This function is guaranteed to return 0 if passed NULL_TREE so
354 that, for example, `template_class_depth (current_class_type)' is
358 template_class_depth (tree type)
363 type && TREE_CODE (type) != NAMESPACE_DECL;
364 type = (TREE_CODE (type) == FUNCTION_DECL)
365 ? CP_DECL_CONTEXT (type) : CP_TYPE_CONTEXT (type))
367 tree tinfo = get_template_info (type);
369 if (tinfo && PRIMARY_TEMPLATE_P (TI_TEMPLATE (tinfo))
370 && uses_template_parms (INNERMOST_TEMPLATE_ARGS (TI_ARGS (tinfo))))
377 /* Subroutine of maybe_begin_member_template_processing.
378 Returns true if processing DECL needs us to push template parms. */
381 inline_needs_template_parms (tree decl)
383 if (! DECL_TEMPLATE_INFO (decl))
386 return (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (most_general_template (decl)))
387 > (processing_template_decl + DECL_TEMPLATE_SPECIALIZATION (decl)));
390 /* Subroutine of maybe_begin_member_template_processing.
391 Push the template parms in PARMS, starting from LEVELS steps into the
392 chain, and ending at the beginning, since template parms are listed
396 push_inline_template_parms_recursive (tree parmlist, int levels)
398 tree parms = TREE_VALUE (parmlist);
402 push_inline_template_parms_recursive (TREE_CHAIN (parmlist), levels - 1);
404 ++processing_template_decl;
405 current_template_parms
406 = tree_cons (size_int (processing_template_decl),
407 parms, current_template_parms);
408 TEMPLATE_PARMS_FOR_INLINE (current_template_parms) = 1;
410 begin_scope (TREE_VEC_LENGTH (parms) ? sk_template_parms : sk_template_spec,
412 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
414 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
416 if (parm == error_mark_node)
419 gcc_assert (DECL_P (parm));
421 switch (TREE_CODE (parm))
430 /* Make a CONST_DECL as is done in process_template_parm.
431 It is ugly that we recreate this here; the original
432 version built in process_template_parm is no longer
434 tree decl = build_decl (DECL_SOURCE_LOCATION (parm),
435 CONST_DECL, DECL_NAME (parm),
437 DECL_ARTIFICIAL (decl) = 1;
438 TREE_CONSTANT (decl) = 1;
439 TREE_READONLY (decl) = 1;
440 DECL_INITIAL (decl) = DECL_INITIAL (parm);
441 SET_DECL_TEMPLATE_PARM_P (decl);
452 /* Restore the template parameter context for a member template or
453 a friend template defined in a class definition. */
456 maybe_begin_member_template_processing (tree decl)
461 if (inline_needs_template_parms (decl))
463 parms = DECL_TEMPLATE_PARMS (most_general_template (decl));
464 levels = TMPL_PARMS_DEPTH (parms) - processing_template_decl;
466 if (DECL_TEMPLATE_SPECIALIZATION (decl))
469 parms = TREE_CHAIN (parms);
472 push_inline_template_parms_recursive (parms, levels);
475 /* Remember how many levels of template parameters we pushed so that
476 we can pop them later. */
477 VEC_safe_push (int, heap, inline_parm_levels, levels);
480 /* Undo the effects of maybe_begin_member_template_processing. */
483 maybe_end_member_template_processing (void)
488 if (VEC_length (int, inline_parm_levels) == 0)
491 last = VEC_pop (int, inline_parm_levels);
492 for (i = 0; i < last; ++i)
494 --processing_template_decl;
495 current_template_parms = TREE_CHAIN (current_template_parms);
500 /* Return a new template argument vector which contains all of ARGS,
501 but has as its innermost set of arguments the EXTRA_ARGS. */
504 add_to_template_args (tree args, tree extra_args)
511 if (args == NULL_TREE || extra_args == error_mark_node)
514 extra_depth = TMPL_ARGS_DEPTH (extra_args);
515 new_args = make_tree_vec (TMPL_ARGS_DEPTH (args) + extra_depth);
517 for (i = 1; i <= TMPL_ARGS_DEPTH (args); ++i)
518 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (args, i));
520 for (j = 1; j <= extra_depth; ++j, ++i)
521 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (extra_args, j));
526 /* Like add_to_template_args, but only the outermost ARGS are added to
527 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
528 (EXTRA_ARGS) levels are added. This function is used to combine
529 the template arguments from a partial instantiation with the
530 template arguments used to attain the full instantiation from the
531 partial instantiation. */
534 add_outermost_template_args (tree args, tree extra_args)
538 /* If there are more levels of EXTRA_ARGS than there are ARGS,
539 something very fishy is going on. */
540 gcc_assert (TMPL_ARGS_DEPTH (args) >= TMPL_ARGS_DEPTH (extra_args));
542 /* If *all* the new arguments will be the EXTRA_ARGS, just return
544 if (TMPL_ARGS_DEPTH (args) == TMPL_ARGS_DEPTH (extra_args))
547 /* For the moment, we make ARGS look like it contains fewer levels. */
548 TREE_VEC_LENGTH (args) -= TMPL_ARGS_DEPTH (extra_args);
550 new_args = add_to_template_args (args, extra_args);
552 /* Now, we restore ARGS to its full dimensions. */
553 TREE_VEC_LENGTH (args) += TMPL_ARGS_DEPTH (extra_args);
558 /* Return the N levels of innermost template arguments from the ARGS. */
561 get_innermost_template_args (tree args, int n)
569 /* If N is 1, just return the innermost set of template arguments. */
571 return TMPL_ARGS_LEVEL (args, TMPL_ARGS_DEPTH (args));
573 /* If we're not removing anything, just return the arguments we were
575 extra_levels = TMPL_ARGS_DEPTH (args) - n;
576 gcc_assert (extra_levels >= 0);
577 if (extra_levels == 0)
580 /* Make a new set of arguments, not containing the outer arguments. */
581 new_args = make_tree_vec (n);
582 for (i = 1; i <= n; ++i)
583 SET_TMPL_ARGS_LEVEL (new_args, i,
584 TMPL_ARGS_LEVEL (args, i + extra_levels));
589 /* The inverse of get_innermost_template_args: Return all but the innermost
590 EXTRA_LEVELS levels of template arguments from the ARGS. */
593 strip_innermost_template_args (tree args, int extra_levels)
596 int n = TMPL_ARGS_DEPTH (args) - extra_levels;
601 /* If N is 1, just return the outermost set of template arguments. */
603 return TMPL_ARGS_LEVEL (args, 1);
605 /* If we're not removing anything, just return the arguments we were
607 gcc_assert (extra_levels >= 0);
608 if (extra_levels == 0)
611 /* Make a new set of arguments, not containing the inner arguments. */
612 new_args = make_tree_vec (n);
613 for (i = 1; i <= n; ++i)
614 SET_TMPL_ARGS_LEVEL (new_args, i,
615 TMPL_ARGS_LEVEL (args, i));
620 /* We've got a template header coming up; push to a new level for storing
624 begin_template_parm_list (void)
626 /* We use a non-tag-transparent scope here, which causes pushtag to
627 put tags in this scope, rather than in the enclosing class or
628 namespace scope. This is the right thing, since we want
629 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
630 global template class, push_template_decl handles putting the
631 TEMPLATE_DECL into top-level scope. For a nested template class,
634 template <class T> struct S1 {
635 template <class T> struct S2 {};
638 pushtag contains special code to call pushdecl_with_scope on the
639 TEMPLATE_DECL for S2. */
640 begin_scope (sk_template_parms, NULL);
641 ++processing_template_decl;
642 ++processing_template_parmlist;
643 note_template_header (0);
646 /* This routine is called when a specialization is declared. If it is
647 invalid to declare a specialization here, an error is reported and
648 false is returned, otherwise this routine will return true. */
651 check_specialization_scope (void)
653 tree scope = current_scope ();
657 An explicit specialization shall be declared in the namespace of
658 which the template is a member, or, for member templates, in the
659 namespace of which the enclosing class or enclosing class
660 template is a member. An explicit specialization of a member
661 function, member class or static data member of a class template
662 shall be declared in the namespace of which the class template
664 if (scope && TREE_CODE (scope) != NAMESPACE_DECL)
666 error ("explicit specialization in non-namespace scope %qD", scope);
672 In an explicit specialization declaration for a member of a class
673 template or a member template that appears in namespace scope,
674 the member template and some of its enclosing class templates may
675 remain unspecialized, except that the declaration shall not
676 explicitly specialize a class member template if its enclosing
677 class templates are not explicitly specialized as well. */
678 if (current_template_parms)
680 error ("enclosing class templates are not explicitly specialized");
687 /* We've just seen template <>. */
690 begin_specialization (void)
692 begin_scope (sk_template_spec, NULL);
693 note_template_header (1);
694 return check_specialization_scope ();
697 /* Called at then end of processing a declaration preceded by
701 end_specialization (void)
704 reset_specialization ();
707 /* Any template <>'s that we have seen thus far are not referring to a
708 function specialization. */
711 reset_specialization (void)
713 processing_specialization = 0;
714 template_header_count = 0;
717 /* We've just seen a template header. If SPECIALIZATION is nonzero,
718 it was of the form template <>. */
721 note_template_header (int specialization)
723 processing_specialization = specialization;
724 template_header_count++;
727 /* We're beginning an explicit instantiation. */
730 begin_explicit_instantiation (void)
732 gcc_assert (!processing_explicit_instantiation);
733 processing_explicit_instantiation = true;
738 end_explicit_instantiation (void)
740 gcc_assert (processing_explicit_instantiation);
741 processing_explicit_instantiation = false;
744 /* An explicit specialization or partial specialization TMPL is being
745 declared. Check that the namespace in which the specialization is
746 occurring is permissible. Returns false iff it is invalid to
747 specialize TMPL in the current namespace. */
750 check_specialization_namespace (tree tmpl)
752 tree tpl_ns = decl_namespace_context (tmpl);
756 An explicit specialization shall be declared in the namespace of
757 which the template is a member, or, for member templates, in the
758 namespace of which the enclosing class or enclosing class
759 template is a member. An explicit specialization of a member
760 function, member class or static data member of a class template
761 shall be declared in the namespace of which the class template is
763 if (current_scope() != DECL_CONTEXT (tmpl)
764 && !at_namespace_scope_p ())
766 error ("specialization of %qD must appear at namespace scope", tmpl);
769 if (is_associated_namespace (current_namespace, tpl_ns))
770 /* Same or super-using namespace. */
774 permerror (input_location, "specialization of %qD in different namespace", tmpl);
775 permerror (input_location, " from definition of %q+#D", tmpl);
780 /* SPEC is an explicit instantiation. Check that it is valid to
781 perform this explicit instantiation in the current namespace. */
784 check_explicit_instantiation_namespace (tree spec)
788 /* DR 275: An explicit instantiation shall appear in an enclosing
789 namespace of its template. */
790 ns = decl_namespace_context (spec);
791 if (!is_ancestor (current_namespace, ns))
792 permerror (input_location, "explicit instantiation of %qD in namespace %qD "
793 "(which does not enclose namespace %qD)",
794 spec, current_namespace, ns);
797 /* The TYPE is being declared. If it is a template type, that means it
798 is a partial specialization. Do appropriate error-checking. */
801 maybe_process_partial_specialization (tree type)
805 if (type == error_mark_node)
806 return error_mark_node;
808 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
810 error ("name of class shadows template template parameter %qD",
812 return error_mark_node;
815 context = TYPE_CONTEXT (type);
817 if ((CLASS_TYPE_P (type) && CLASSTYPE_USE_TEMPLATE (type))
818 /* Consider non-class instantiations of alias templates as
821 && TYPE_TEMPLATE_INFO (type)
822 && DECL_LANG_SPECIFIC (TYPE_NAME (type))
823 && DECL_USE_TEMPLATE (TYPE_NAME (type))))
825 /* This is for ordinary explicit specialization and partial
826 specialization of a template class such as:
828 template <> class C<int>;
832 template <class T> class C<T*>;
834 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
836 if (CLASS_TYPE_P (type)
837 && CLASSTYPE_IMPLICIT_INSTANTIATION (type)
838 && !COMPLETE_TYPE_P (type))
840 check_specialization_namespace (CLASSTYPE_TI_TEMPLATE (type));
841 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
842 if (processing_template_decl)
844 if (push_template_decl (TYPE_MAIN_DECL (type))
846 return error_mark_node;
849 else if (CLASS_TYPE_P (type)
850 && CLASSTYPE_TEMPLATE_INSTANTIATION (type))
851 error ("specialization of %qT after instantiation", type);
853 if (DECL_ALIAS_TEMPLATE_P (TYPE_TI_TEMPLATE (type)))
855 error ("partial specialization of alias template %qD",
856 TYPE_TI_TEMPLATE (type));
857 return error_mark_node;
860 else if (CLASS_TYPE_P (type)
861 && !CLASSTYPE_USE_TEMPLATE (type)
862 && CLASSTYPE_TEMPLATE_INFO (type)
863 && context && CLASS_TYPE_P (context)
864 && CLASSTYPE_TEMPLATE_INFO (context))
866 /* This is for an explicit specialization of member class
867 template according to [temp.expl.spec/18]:
869 template <> template <class U> class C<int>::D;
871 The context `C<int>' must be an implicit instantiation.
872 Otherwise this is just a member class template declared
875 template <> class C<int> { template <class U> class D; };
876 template <> template <class U> class C<int>::D;
878 In the first case, `C<int>::D' is a specialization of `C<T>::D'
879 while in the second case, `C<int>::D' is a primary template
880 and `C<T>::D' may not exist. */
882 if (CLASSTYPE_IMPLICIT_INSTANTIATION (context)
883 && !COMPLETE_TYPE_P (type))
886 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
888 if (current_namespace
889 != decl_namespace_context (tmpl))
891 permerror (input_location, "specializing %q#T in different namespace", type);
892 permerror (input_location, " from definition of %q+#D", tmpl);
895 /* Check for invalid specialization after instantiation:
897 template <> template <> class C<int>::D<int>;
898 template <> template <class U> class C<int>::D; */
900 for (t = DECL_TEMPLATE_INSTANTIATIONS (tmpl);
901 t; t = TREE_CHAIN (t))
903 tree inst = TREE_VALUE (t);
904 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (inst))
906 /* We already have a full specialization of this partial
907 instantiation. Reassign it to the new member
908 specialization template. */
913 elt.tmpl = most_general_template (tmpl);
914 elt.args = CLASSTYPE_TI_ARGS (inst);
917 htab_remove_elt (type_specializations, &elt);
920 elt.args = INNERMOST_TEMPLATE_ARGS (elt.args);
922 slot = htab_find_slot (type_specializations, &elt, INSERT);
923 entry = ggc_alloc_spec_entry ();
927 else if (COMPLETE_OR_OPEN_TYPE_P (inst))
928 /* But if we've had an implicit instantiation, that's a
929 problem ([temp.expl.spec]/6). */
930 error ("specialization %qT after instantiation %qT",
934 /* Mark TYPE as a specialization. And as a result, we only
935 have one level of template argument for the innermost
937 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
938 CLASSTYPE_TI_ARGS (type)
939 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type));
942 else if (processing_specialization)
944 /* Someday C++0x may allow for enum template specialization. */
945 if (cxx_dialect > cxx98 && TREE_CODE (type) == ENUMERAL_TYPE
946 && CLASS_TYPE_P (context) && CLASSTYPE_USE_TEMPLATE (context))
947 pedwarn (input_location, OPT_pedantic, "template specialization "
948 "of %qD not allowed by ISO C++", type);
951 error ("explicit specialization of non-template %qT", type);
952 return error_mark_node;
959 /* Returns nonzero if we can optimize the retrieval of specializations
960 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
961 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
964 optimize_specialization_lookup_p (tree tmpl)
966 return (DECL_FUNCTION_TEMPLATE_P (tmpl)
967 && DECL_CLASS_SCOPE_P (tmpl)
968 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
970 && CLASS_TYPE_P (DECL_CONTEXT (tmpl))
971 /* The optimized lookup depends on the fact that the
972 template arguments for the member function template apply
973 purely to the containing class, which is not true if the
974 containing class is an explicit or partial
976 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (tmpl))
977 && !DECL_MEMBER_TEMPLATE_P (tmpl)
978 && !DECL_CONV_FN_P (tmpl)
979 /* It is possible to have a template that is not a member
980 template and is not a member of a template class:
982 template <typename T>
983 struct S { friend A::f(); };
985 Here, the friend function is a template, but the context does
986 not have template information. The optimized lookup relies
987 on having ARGS be the template arguments for both the class
988 and the function template. */
989 && !DECL_FRIEND_P (DECL_TEMPLATE_RESULT (tmpl)));
992 /* Retrieve the specialization (in the sense of [temp.spec] - a
993 specialization is either an instantiation or an explicit
994 specialization) of TMPL for the given template ARGS. If there is
995 no such specialization, return NULL_TREE. The ARGS are a vector of
996 arguments, or a vector of vectors of arguments, in the case of
997 templates with more than one level of parameters.
999 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
1000 then we search for a partial specialization matching ARGS. This
1001 parameter is ignored if TMPL is not a class template. */
1004 retrieve_specialization (tree tmpl, tree args, hashval_t hash)
1006 if (args == error_mark_node)
1009 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
1011 /* There should be as many levels of arguments as there are
1012 levels of parameters. */
1013 gcc_assert (TMPL_ARGS_DEPTH (args)
1014 == TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl)));
1016 if (optimize_specialization_lookup_p (tmpl))
1018 tree class_template;
1019 tree class_specialization;
1020 VEC(tree,gc) *methods;
1024 /* The template arguments actually apply to the containing
1025 class. Find the class specialization with those
1027 class_template = CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (tmpl));
1028 class_specialization
1029 = retrieve_specialization (class_template, args, 0);
1030 if (!class_specialization)
1032 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
1033 for the specialization. */
1034 idx = class_method_index_for_fn (class_specialization, tmpl);
1037 /* Iterate through the methods with the indicated name, looking
1038 for the one that has an instance of TMPL. */
1039 methods = CLASSTYPE_METHOD_VEC (class_specialization);
1040 for (fns = VEC_index (tree, methods, idx); fns; fns = OVL_NEXT (fns))
1042 tree fn = OVL_CURRENT (fns);
1043 if (DECL_TEMPLATE_INFO (fn) && DECL_TI_TEMPLATE (fn) == tmpl
1044 /* using-declarations can add base methods to the method vec,
1045 and we don't want those here. */
1046 && DECL_CONTEXT (fn) == class_specialization)
1055 htab_t specializations;
1059 elt.spec = NULL_TREE;
1061 if (DECL_CLASS_TEMPLATE_P (tmpl))
1062 specializations = type_specializations;
1064 specializations = decl_specializations;
1067 hash = hash_specialization (&elt);
1068 found = (spec_entry *) htab_find_with_hash (specializations, &elt, hash);
1076 /* Like retrieve_specialization, but for local declarations. */
1079 retrieve_local_specialization (tree tmpl)
1083 if (local_specializations == NULL)
1086 spec = (tree) htab_find_with_hash (local_specializations, tmpl,
1087 htab_hash_pointer (tmpl));
1088 return spec ? TREE_PURPOSE (spec) : NULL_TREE;
1091 /* Returns nonzero iff DECL is a specialization of TMPL. */
1094 is_specialization_of (tree decl, tree tmpl)
1098 if (TREE_CODE (decl) == FUNCTION_DECL)
1102 t = DECL_TEMPLATE_INFO (t) ? DECL_TI_TEMPLATE (t) : NULL_TREE)
1108 gcc_assert (TREE_CODE (decl) == TYPE_DECL);
1110 for (t = TREE_TYPE (decl);
1112 t = CLASSTYPE_USE_TEMPLATE (t)
1113 ? TREE_TYPE (CLASSTYPE_TI_TEMPLATE (t)) : NULL_TREE)
1114 if (same_type_ignoring_top_level_qualifiers_p (t, TREE_TYPE (tmpl)))
1121 /* Returns nonzero iff DECL is a specialization of friend declaration
1122 FRIEND_DECL according to [temp.friend]. */
1125 is_specialization_of_friend (tree decl, tree friend_decl)
1127 bool need_template = true;
1130 gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
1131 || TREE_CODE (decl) == TYPE_DECL);
1133 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1134 of a template class, we want to check if DECL is a specialization
1136 if (TREE_CODE (friend_decl) == FUNCTION_DECL
1137 && DECL_TEMPLATE_INFO (friend_decl)
1138 && !DECL_USE_TEMPLATE (friend_decl))
1140 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1141 friend_decl = DECL_TI_TEMPLATE (friend_decl);
1142 need_template = false;
1144 else if (TREE_CODE (friend_decl) == TEMPLATE_DECL
1145 && !PRIMARY_TEMPLATE_P (friend_decl))
1146 need_template = false;
1148 /* There is nothing to do if this is not a template friend. */
1149 if (TREE_CODE (friend_decl) != TEMPLATE_DECL)
1152 if (is_specialization_of (decl, friend_decl))
1156 A member of a class template may be declared to be a friend of a
1157 non-template class. In this case, the corresponding member of
1158 every specialization of the class template is a friend of the
1159 class granting friendship.
1161 For example, given a template friend declaration
1163 template <class T> friend void A<T>::f();
1165 the member function below is considered a friend
1167 template <> struct A<int> {
1171 For this type of template friend, TEMPLATE_DEPTH below will be
1172 nonzero. To determine if DECL is a friend of FRIEND, we first
1173 check if the enclosing class is a specialization of another. */
1175 template_depth = template_class_depth (CP_DECL_CONTEXT (friend_decl));
1177 && DECL_CLASS_SCOPE_P (decl)
1178 && is_specialization_of (TYPE_NAME (DECL_CONTEXT (decl)),
1179 CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (friend_decl))))
1181 /* Next, we check the members themselves. In order to handle
1182 a few tricky cases, such as when FRIEND_DECL's are
1184 template <class T> friend void A<T>::g(T t);
1185 template <class T> template <T t> friend void A<T>::h();
1189 void A<int>::g(int);
1190 template <int> void A<int>::h();
1192 we need to figure out ARGS, the template arguments from
1193 the context of DECL. This is required for template substitution
1194 of `T' in the function parameter of `g' and template parameter
1195 of `h' in the above examples. Here ARGS corresponds to `int'. */
1197 tree context = DECL_CONTEXT (decl);
1198 tree args = NULL_TREE;
1199 int current_depth = 0;
1201 while (current_depth < template_depth)
1203 if (CLASSTYPE_TEMPLATE_INFO (context))
1205 if (current_depth == 0)
1206 args = TYPE_TI_ARGS (context);
1208 args = add_to_template_args (TYPE_TI_ARGS (context), args);
1211 context = TYPE_CONTEXT (context);
1214 if (TREE_CODE (decl) == FUNCTION_DECL)
1219 tree friend_args_type;
1220 tree decl_args_type;
1222 /* Make sure that both DECL and FRIEND_DECL are templates or
1224 is_template = DECL_TEMPLATE_INFO (decl)
1225 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (decl));
1226 if (need_template ^ is_template)
1228 else if (is_template)
1230 /* If both are templates, check template parameter list. */
1232 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1234 if (!comp_template_parms
1235 (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (decl)),
1239 decl_type = TREE_TYPE (DECL_TI_TEMPLATE (decl));
1242 decl_type = TREE_TYPE (decl);
1244 friend_type = tsubst_function_type (TREE_TYPE (friend_decl), args,
1245 tf_none, NULL_TREE);
1246 if (friend_type == error_mark_node)
1249 /* Check if return types match. */
1250 if (!same_type_p (TREE_TYPE (decl_type), TREE_TYPE (friend_type)))
1253 /* Check if function parameter types match, ignoring the
1254 `this' parameter. */
1255 friend_args_type = TYPE_ARG_TYPES (friend_type);
1256 decl_args_type = TYPE_ARG_TYPES (decl_type);
1257 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (friend_decl))
1258 friend_args_type = TREE_CHAIN (friend_args_type);
1259 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1260 decl_args_type = TREE_CHAIN (decl_args_type);
1262 return compparms (decl_args_type, friend_args_type);
1266 /* DECL is a TYPE_DECL */
1268 tree decl_type = TREE_TYPE (decl);
1270 /* Make sure that both DECL and FRIEND_DECL are templates or
1273 = CLASSTYPE_TEMPLATE_INFO (decl_type)
1274 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (decl_type));
1276 if (need_template ^ is_template)
1278 else if (is_template)
1281 /* If both are templates, check the name of the two
1282 TEMPLATE_DECL's first because is_friend didn't. */
1283 if (DECL_NAME (CLASSTYPE_TI_TEMPLATE (decl_type))
1284 != DECL_NAME (friend_decl))
1287 /* Now check template parameter list. */
1289 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1291 return comp_template_parms
1292 (DECL_TEMPLATE_PARMS (CLASSTYPE_TI_TEMPLATE (decl_type)),
1296 return (DECL_NAME (decl)
1297 == DECL_NAME (friend_decl));
1303 /* Register the specialization SPEC as a specialization of TMPL with
1304 the indicated ARGS. IS_FRIEND indicates whether the specialization
1305 is actually just a friend declaration. Returns SPEC, or an
1306 equivalent prior declaration, if available. */
1309 register_specialization (tree spec, tree tmpl, tree args, bool is_friend,
1316 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL && DECL_P (spec));
1318 if (TREE_CODE (spec) == FUNCTION_DECL
1319 && uses_template_parms (DECL_TI_ARGS (spec)))
1320 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1321 register it; we want the corresponding TEMPLATE_DECL instead.
1322 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1323 the more obvious `uses_template_parms (spec)' to avoid problems
1324 with default function arguments. In particular, given
1325 something like this:
1327 template <class T> void f(T t1, T t = T())
1329 the default argument expression is not substituted for in an
1330 instantiation unless and until it is actually needed. */
1333 if (optimize_specialization_lookup_p (tmpl))
1334 /* We don't put these specializations in the hash table, but we might
1335 want to give an error about a mismatch. */
1336 fn = retrieve_specialization (tmpl, args, 0);
1344 hash = hash_specialization (&elt);
1347 htab_find_slot_with_hash (decl_specializations, &elt, hash, INSERT);
1349 fn = ((spec_entry *) *slot)->spec;
1354 /* We can sometimes try to re-register a specialization that we've
1355 already got. In particular, regenerate_decl_from_template calls
1356 duplicate_decls which will update the specialization list. But,
1357 we'll still get called again here anyhow. It's more convenient
1358 to simply allow this than to try to prevent it. */
1361 else if (fn && DECL_TEMPLATE_SPECIALIZATION (spec))
1363 if (DECL_TEMPLATE_INSTANTIATION (fn))
1365 if (DECL_ODR_USED (fn)
1366 || DECL_EXPLICIT_INSTANTIATION (fn))
1368 error ("specialization of %qD after instantiation",
1370 return error_mark_node;
1375 /* This situation should occur only if the first
1376 specialization is an implicit instantiation, the
1377 second is an explicit specialization, and the
1378 implicit instantiation has not yet been used. That
1379 situation can occur if we have implicitly
1380 instantiated a member function and then specialized
1383 We can also wind up here if a friend declaration that
1384 looked like an instantiation turns out to be a
1387 template <class T> void foo(T);
1388 class S { friend void foo<>(int) };
1389 template <> void foo(int);
1391 We transform the existing DECL in place so that any
1392 pointers to it become pointers to the updated
1395 If there was a definition for the template, but not
1396 for the specialization, we want this to look as if
1397 there were no definition, and vice versa. */
1398 DECL_INITIAL (fn) = NULL_TREE;
1399 duplicate_decls (spec, fn, is_friend);
1400 /* The call to duplicate_decls will have applied
1403 An explicit specialization of a function template
1404 is inline only if it is explicitly declared to be,
1405 and independently of whether its function template
1408 to the primary function; now copy the inline bits to
1409 the various clones. */
1410 FOR_EACH_CLONE (clone, fn)
1412 DECL_DECLARED_INLINE_P (clone)
1413 = DECL_DECLARED_INLINE_P (fn);
1414 DECL_SOURCE_LOCATION (clone)
1415 = DECL_SOURCE_LOCATION (fn);
1417 check_specialization_namespace (fn);
1422 else if (DECL_TEMPLATE_SPECIALIZATION (fn))
1424 if (!duplicate_decls (spec, fn, is_friend) && DECL_INITIAL (spec))
1425 /* Dup decl failed, but this is a new definition. Set the
1426 line number so any errors match this new
1428 DECL_SOURCE_LOCATION (fn) = DECL_SOURCE_LOCATION (spec);
1434 return duplicate_decls (spec, fn, is_friend);
1436 /* A specialization must be declared in the same namespace as the
1437 template it is specializing. */
1438 if (DECL_TEMPLATE_SPECIALIZATION (spec)
1439 && !check_specialization_namespace (tmpl))
1440 DECL_CONTEXT (spec) = DECL_CONTEXT (tmpl);
1442 if (slot != NULL /* !optimize_specialization_lookup_p (tmpl) */)
1444 spec_entry *entry = ggc_alloc_spec_entry ();
1445 gcc_assert (tmpl && args && spec);
1448 if (TREE_CODE (spec) == FUNCTION_DECL && DECL_NAMESPACE_SCOPE_P (spec)
1449 && PRIMARY_TEMPLATE_P (tmpl)
1450 && DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (tmpl)) == NULL_TREE)
1451 /* TMPL is a forward declaration of a template function; keep a list
1452 of all specializations in case we need to reassign them to a friend
1453 template later in tsubst_friend_function. */
1454 DECL_TEMPLATE_INSTANTIATIONS (tmpl)
1455 = tree_cons (args, spec, DECL_TEMPLATE_INSTANTIATIONS (tmpl));
1461 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1462 TMPL and ARGS members, ignores SPEC. */
1465 eq_specializations (const void *p1, const void *p2)
1467 const spec_entry *e1 = (const spec_entry *)p1;
1468 const spec_entry *e2 = (const spec_entry *)p2;
1470 return (e1->tmpl == e2->tmpl
1471 && comp_template_args (e1->args, e2->args));
1474 /* Returns a hash for a template TMPL and template arguments ARGS. */
1477 hash_tmpl_and_args (tree tmpl, tree args)
1479 hashval_t val = DECL_UID (tmpl);
1480 return iterative_hash_template_arg (args, val);
1483 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1487 hash_specialization (const void *p)
1489 const spec_entry *e = (const spec_entry *)p;
1490 return hash_tmpl_and_args (e->tmpl, e->args);
1493 /* Recursively calculate a hash value for a template argument ARG, for use
1494 in the hash tables of template specializations. */
1497 iterative_hash_template_arg (tree arg, hashval_t val)
1499 unsigned HOST_WIDE_INT i;
1500 enum tree_code code;
1503 if (arg == NULL_TREE)
1504 return iterative_hash_object (arg, val);
1509 if (TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
1510 /* We can get one of these when re-hashing a previous entry in the middle
1511 of substituting into a pack expansion. Just look through it. */
1512 arg = ARGUMENT_PACK_SELECT_FROM_PACK (arg);
1514 code = TREE_CODE (arg);
1515 tclass = TREE_CODE_CLASS (code);
1517 val = iterative_hash_object (code, val);
1524 case IDENTIFIER_NODE:
1525 return iterative_hash_object (IDENTIFIER_HASH_VALUE (arg), val);
1529 int i, len = TREE_VEC_LENGTH (arg);
1530 for (i = 0; i < len; ++i)
1531 val = iterative_hash_template_arg (TREE_VEC_ELT (arg, i), val);
1535 case TYPE_PACK_EXPANSION:
1536 case EXPR_PACK_EXPANSION:
1537 val = iterative_hash_template_arg (PACK_EXPANSION_PATTERN (arg), val);
1538 return iterative_hash_template_arg (PACK_EXPANSION_EXTRA_ARGS (arg), val);
1540 case TYPE_ARGUMENT_PACK:
1541 case NONTYPE_ARGUMENT_PACK:
1542 return iterative_hash_template_arg (ARGUMENT_PACK_ARGS (arg), val);
1545 for (; arg; arg = TREE_CHAIN (arg))
1546 val = iterative_hash_template_arg (TREE_VALUE (arg), val);
1550 for (; arg; arg = OVL_NEXT (arg))
1551 val = iterative_hash_template_arg (OVL_CURRENT (arg), val);
1557 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg), i, field, value)
1559 val = iterative_hash_template_arg (field, val);
1560 val = iterative_hash_template_arg (value, val);
1566 if (!DECL_ARTIFICIAL (arg))
1568 val = iterative_hash_object (DECL_PARM_INDEX (arg), val);
1569 val = iterative_hash_object (DECL_PARM_LEVEL (arg), val);
1571 return iterative_hash_template_arg (TREE_TYPE (arg), val);
1574 return iterative_hash_template_arg (TARGET_EXPR_INITIAL (arg), val);
1577 val = iterative_hash_template_arg (PTRMEM_CST_CLASS (arg), val);
1578 return iterative_hash_template_arg (PTRMEM_CST_MEMBER (arg), val);
1580 case TEMPLATE_PARM_INDEX:
1581 val = iterative_hash_template_arg
1582 (TREE_TYPE (TEMPLATE_PARM_DECL (arg)), val);
1583 val = iterative_hash_object (TEMPLATE_PARM_LEVEL (arg), val);
1584 return iterative_hash_object (TEMPLATE_PARM_IDX (arg), val);
1587 val = iterative_hash_object (TRAIT_EXPR_KIND (arg), val);
1588 val = iterative_hash_template_arg (TRAIT_EXPR_TYPE1 (arg), val);
1589 return iterative_hash_template_arg (TRAIT_EXPR_TYPE2 (arg), val);
1592 val = iterative_hash_template_arg (BINFO_TYPE (BASELINK_BINFO (arg)),
1594 return iterative_hash_template_arg (DECL_NAME (get_first_fn (arg)),
1598 val = iterative_hash_template_arg (TREE_OPERAND (arg, 0), val);
1599 code = TREE_CODE (TREE_OPERAND (arg, 1));
1600 val = iterative_hash_object (code, val);
1601 return iterative_hash_template_arg (TREE_OPERAND (arg, 2), val);
1604 /* A lambda can't appear in a template arg, but don't crash on
1606 gcc_assert (seen_error ());
1610 case IMPLICIT_CONV_EXPR:
1611 case STATIC_CAST_EXPR:
1612 case REINTERPRET_CAST_EXPR:
1613 case CONST_CAST_EXPR:
1614 case DYNAMIC_CAST_EXPR:
1616 val = iterative_hash_template_arg (TREE_TYPE (arg), val);
1617 /* Now hash operands as usual. */
1627 if (TYPE_CANONICAL (arg))
1628 return iterative_hash_object (TYPE_HASH (TYPE_CANONICAL (arg)),
1630 else if (TREE_CODE (arg) == DECLTYPE_TYPE)
1631 return iterative_hash_template_arg (DECLTYPE_TYPE_EXPR (arg), val);
1632 /* Otherwise just compare the types during lookup. */
1635 case tcc_declaration:
1637 return iterative_hash_expr (arg, val);
1640 gcc_assert (IS_EXPR_CODE_CLASS (tclass));
1642 unsigned n = cp_tree_operand_length (arg);
1643 for (i = 0; i < n; ++i)
1644 val = iterative_hash_template_arg (TREE_OPERAND (arg, i), val);
1652 /* Unregister the specialization SPEC as a specialization of TMPL.
1653 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1654 if the SPEC was listed as a specialization of TMPL.
1656 Note that SPEC has been ggc_freed, so we can't look inside it. */
1659 reregister_specialization (tree spec, tree tinfo, tree new_spec)
1664 elt.tmpl = most_general_template (TI_TEMPLATE (tinfo));
1665 elt.args = TI_ARGS (tinfo);
1666 elt.spec = NULL_TREE;
1668 entry = (spec_entry *) htab_find (decl_specializations, &elt);
1671 gcc_assert (entry->spec == spec || entry->spec == new_spec);
1672 gcc_assert (new_spec != NULL_TREE);
1673 entry->spec = new_spec;
1680 /* Compare an entry in the local specializations hash table P1 (which
1681 is really a pointer to a TREE_LIST) with P2 (which is really a
1685 eq_local_specializations (const void *p1, const void *p2)
1687 return TREE_VALUE ((const_tree) p1) == (const_tree) p2;
1690 /* Hash P1, an entry in the local specializations table. */
1693 hash_local_specialization (const void* p1)
1695 return htab_hash_pointer (TREE_VALUE ((const_tree) p1));
1698 /* Like register_specialization, but for local declarations. We are
1699 registering SPEC, an instantiation of TMPL. */
1702 register_local_specialization (tree spec, tree tmpl)
1706 slot = htab_find_slot_with_hash (local_specializations, tmpl,
1707 htab_hash_pointer (tmpl), INSERT);
1708 *slot = build_tree_list (spec, tmpl);
1711 /* TYPE is a class type. Returns true if TYPE is an explicitly
1712 specialized class. */
1715 explicit_class_specialization_p (tree type)
1717 if (!CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
1719 return !uses_template_parms (CLASSTYPE_TI_ARGS (type));
1722 /* Print the list of functions at FNS, going through all the overloads
1723 for each element of the list. Alternatively, FNS can not be a
1724 TREE_LIST, in which case it will be printed together with all the
1727 MORE and *STR should respectively be FALSE and NULL when the function
1728 is called from the outside. They are used internally on recursive
1729 calls. print_candidates manages the two parameters and leaves NULL
1730 in *STR when it ends. */
1733 print_candidates_1 (tree fns, bool more, const char **str)
1736 char *spaces = NULL;
1738 for (fn = fns; fn; fn = OVL_NEXT (fn))
1739 if (TREE_CODE (fn) == TREE_LIST)
1741 for (fn2 = fn; fn2 != NULL_TREE; fn2 = TREE_CHAIN (fn2))
1742 print_candidates_1 (TREE_VALUE (fn2),
1743 TREE_CHAIN (fn2) || more, str);
1749 /* Pick the prefix string. */
1750 if (!more && !OVL_NEXT (fns))
1752 error ("candidate is: %+#D", OVL_CURRENT (fn));
1756 *str = _("candidates are:");
1757 spaces = get_spaces (*str);
1759 error ("%s %+#D", *str, OVL_CURRENT (fn));
1760 *str = spaces ? spaces : *str;
1770 /* Print the list of candidate FNS in an error message. FNS can also
1771 be a TREE_LIST of non-functions in the case of an ambiguous lookup. */
1774 print_candidates (tree fns)
1776 const char *str = NULL;
1777 print_candidates_1 (fns, false, &str);
1778 gcc_assert (str == NULL);
1781 /* Returns the template (one of the functions given by TEMPLATE_ID)
1782 which can be specialized to match the indicated DECL with the
1783 explicit template args given in TEMPLATE_ID. The DECL may be
1784 NULL_TREE if none is available. In that case, the functions in
1785 TEMPLATE_ID are non-members.
1787 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1788 specialization of a member template.
1790 The TEMPLATE_COUNT is the number of references to qualifying
1791 template classes that appeared in the name of the function. See
1792 check_explicit_specialization for a more accurate description.
1794 TSK indicates what kind of template declaration (if any) is being
1795 declared. TSK_TEMPLATE indicates that the declaration given by
1796 DECL, though a FUNCTION_DECL, has template parameters, and is
1797 therefore a template function.
1799 The template args (those explicitly specified and those deduced)
1800 are output in a newly created vector *TARGS_OUT.
1802 If it is impossible to determine the result, an error message is
1803 issued. The error_mark_node is returned to indicate failure. */
1806 determine_specialization (tree template_id,
1809 int need_member_template,
1815 tree explicit_targs;
1816 tree candidates = NULL_TREE;
1817 /* A TREE_LIST of templates of which DECL may be a specialization.
1818 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1819 corresponding TREE_PURPOSE is the set of template arguments that,
1820 when used to instantiate the template, would produce a function
1821 with the signature of DECL. */
1822 tree templates = NULL_TREE;
1824 cp_binding_level *b;
1826 *targs_out = NULL_TREE;
1828 if (template_id == error_mark_node || decl == error_mark_node)
1829 return error_mark_node;
1831 fns = TREE_OPERAND (template_id, 0);
1832 explicit_targs = TREE_OPERAND (template_id, 1);
1834 if (fns == error_mark_node)
1835 return error_mark_node;
1837 /* Check for baselinks. */
1838 if (BASELINK_P (fns))
1839 fns = BASELINK_FUNCTIONS (fns);
1841 if (!is_overloaded_fn (fns))
1843 error ("%qD is not a function template", fns);
1844 return error_mark_node;
1847 /* Count the number of template headers specified for this
1850 for (b = current_binding_level;
1851 b->kind == sk_template_parms;
1855 for (; fns; fns = OVL_NEXT (fns))
1857 tree fn = OVL_CURRENT (fns);
1859 if (TREE_CODE (fn) == TEMPLATE_DECL)
1861 tree decl_arg_types;
1864 /* In case of explicit specialization, we need to check if
1865 the number of template headers appearing in the specialization
1866 is correct. This is usually done in check_explicit_specialization,
1867 but the check done there cannot be exhaustive when specializing
1868 member functions. Consider the following code:
1870 template <> void A<int>::f(int);
1871 template <> template <> void A<int>::f(int);
1873 Assuming that A<int> is not itself an explicit specialization
1874 already, the first line specializes "f" which is a non-template
1875 member function, whilst the second line specializes "f" which
1876 is a template member function. So both lines are syntactically
1877 correct, and check_explicit_specialization does not reject
1880 Here, we can do better, as we are matching the specialization
1881 against the declarations. We count the number of template
1882 headers, and we check if they match TEMPLATE_COUNT + 1
1883 (TEMPLATE_COUNT is the number of qualifying template classes,
1884 plus there must be another header for the member template
1887 Notice that if header_count is zero, this is not a
1888 specialization but rather a template instantiation, so there
1889 is no check we can perform here. */
1890 if (header_count && header_count != template_count + 1)
1893 /* Check that the number of template arguments at the
1894 innermost level for DECL is the same as for FN. */
1895 if (current_binding_level->kind == sk_template_parms
1896 && !current_binding_level->explicit_spec_p
1897 && (TREE_VEC_LENGTH (DECL_INNERMOST_TEMPLATE_PARMS (fn))
1898 != TREE_VEC_LENGTH (INNERMOST_TEMPLATE_PARMS
1899 (current_template_parms))))
1902 /* DECL might be a specialization of FN. */
1903 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1904 fn_arg_types = TYPE_ARG_TYPES (TREE_TYPE (fn));
1906 /* For a non-static member function, we need to make sure
1907 that the const qualification is the same. Since
1908 get_bindings does not try to merge the "this" parameter,
1909 we must do the comparison explicitly. */
1910 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
1911 && !same_type_p (TREE_VALUE (fn_arg_types),
1912 TREE_VALUE (decl_arg_types)))
1915 /* Skip the "this" parameter and, for constructors of
1916 classes with virtual bases, the VTT parameter. A
1917 full specialization of a constructor will have a VTT
1918 parameter, but a template never will. */
1920 = skip_artificial_parms_for (decl, decl_arg_types);
1922 = skip_artificial_parms_for (fn, fn_arg_types);
1924 /* Check that the number of function parameters matches.
1926 template <class T> void f(int i = 0);
1927 template <> void f<int>();
1928 The specialization f<int> is invalid but is not caught
1929 by get_bindings below. */
1930 if (list_length (fn_arg_types) != list_length (decl_arg_types))
1933 /* Function templates cannot be specializations; there are
1934 no partial specializations of functions. Therefore, if
1935 the type of DECL does not match FN, there is no
1937 if (tsk == tsk_template)
1939 if (compparms (fn_arg_types, decl_arg_types))
1940 candidates = tree_cons (NULL_TREE, fn, candidates);
1944 /* See whether this function might be a specialization of this
1946 targs = get_bindings (fn, decl, explicit_targs, /*check_ret=*/true);
1949 /* We cannot deduce template arguments that when used to
1950 specialize TMPL will produce DECL. */
1953 /* Save this template, and the arguments deduced. */
1954 templates = tree_cons (targs, fn, templates);
1956 else if (need_member_template)
1957 /* FN is an ordinary member function, and we need a
1958 specialization of a member template. */
1960 else if (TREE_CODE (fn) != FUNCTION_DECL)
1961 /* We can get IDENTIFIER_NODEs here in certain erroneous
1964 else if (!DECL_FUNCTION_MEMBER_P (fn))
1965 /* This is just an ordinary non-member function. Nothing can
1966 be a specialization of that. */
1968 else if (DECL_ARTIFICIAL (fn))
1969 /* Cannot specialize functions that are created implicitly. */
1973 tree decl_arg_types;
1975 /* This is an ordinary member function. However, since
1976 we're here, we can assume it's enclosing class is a
1977 template class. For example,
1979 template <typename T> struct S { void f(); };
1980 template <> void S<int>::f() {}
1982 Here, S<int>::f is a non-template, but S<int> is a
1983 template class. If FN has the same type as DECL, we
1984 might be in business. */
1986 if (!DECL_TEMPLATE_INFO (fn))
1987 /* Its enclosing class is an explicit specialization
1988 of a template class. This is not a candidate. */
1991 if (!same_type_p (TREE_TYPE (TREE_TYPE (decl)),
1992 TREE_TYPE (TREE_TYPE (fn))))
1993 /* The return types differ. */
1996 /* Adjust the type of DECL in case FN is a static member. */
1997 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1998 if (DECL_STATIC_FUNCTION_P (fn)
1999 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2000 decl_arg_types = TREE_CHAIN (decl_arg_types);
2002 if (compparms (TYPE_ARG_TYPES (TREE_TYPE (fn)),
2005 candidates = tree_cons (NULL_TREE, fn, candidates);
2009 if (templates && TREE_CHAIN (templates))
2015 It is possible for a specialization with a given function
2016 signature to be instantiated from more than one function
2017 template. In such cases, explicit specification of the
2018 template arguments must be used to uniquely identify the
2019 function template specialization being specialized.
2021 Note that here, there's no suggestion that we're supposed to
2022 determine which of the candidate templates is most
2023 specialized. However, we, also have:
2027 Partial ordering of overloaded function template
2028 declarations is used in the following contexts to select
2029 the function template to which a function template
2030 specialization refers:
2032 -- when an explicit specialization refers to a function
2035 So, we do use the partial ordering rules, at least for now.
2036 This extension can only serve to make invalid programs valid,
2037 so it's safe. And, there is strong anecdotal evidence that
2038 the committee intended the partial ordering rules to apply;
2039 the EDG front end has that behavior, and John Spicer claims
2040 that the committee simply forgot to delete the wording in
2041 [temp.expl.spec]. */
2042 tree tmpl = most_specialized_instantiation (templates);
2043 if (tmpl != error_mark_node)
2046 TREE_CHAIN (templates) = NULL_TREE;
2050 if (templates == NULL_TREE && candidates == NULL_TREE)
2052 error ("template-id %qD for %q+D does not match any template "
2053 "declaration", template_id, decl);
2054 if (header_count && header_count != template_count + 1)
2055 inform (input_location, "saw %d %<template<>%>, need %d for "
2056 "specializing a member function template",
2057 header_count, template_count + 1);
2058 return error_mark_node;
2060 else if ((templates && TREE_CHAIN (templates))
2061 || (candidates && TREE_CHAIN (candidates))
2062 || (templates && candidates))
2064 error ("ambiguous template specialization %qD for %q+D",
2066 candidates = chainon (candidates, templates);
2067 print_candidates (candidates);
2068 return error_mark_node;
2071 /* We have one, and exactly one, match. */
2074 tree fn = TREE_VALUE (candidates);
2075 *targs_out = copy_node (DECL_TI_ARGS (fn));
2076 /* DECL is a re-declaration or partial instantiation of a template
2078 if (TREE_CODE (fn) == TEMPLATE_DECL)
2080 /* It was a specialization of an ordinary member function in a
2082 return DECL_TI_TEMPLATE (fn);
2085 /* It was a specialization of a template. */
2086 targs = DECL_TI_ARGS (DECL_TEMPLATE_RESULT (TREE_VALUE (templates)));
2087 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (targs))
2089 *targs_out = copy_node (targs);
2090 SET_TMPL_ARGS_LEVEL (*targs_out,
2091 TMPL_ARGS_DEPTH (*targs_out),
2092 TREE_PURPOSE (templates));
2095 *targs_out = TREE_PURPOSE (templates);
2096 return TREE_VALUE (templates);
2099 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2100 but with the default argument values filled in from those in the
2104 copy_default_args_to_explicit_spec_1 (tree spec_types,
2107 tree new_spec_types;
2112 if (spec_types == void_list_node)
2113 return void_list_node;
2115 /* Substitute into the rest of the list. */
2117 copy_default_args_to_explicit_spec_1 (TREE_CHAIN (spec_types),
2118 TREE_CHAIN (tmpl_types));
2120 /* Add the default argument for this parameter. */
2121 return hash_tree_cons (TREE_PURPOSE (tmpl_types),
2122 TREE_VALUE (spec_types),
2126 /* DECL is an explicit specialization. Replicate default arguments
2127 from the template it specializes. (That way, code like:
2129 template <class T> void f(T = 3);
2130 template <> void f(double);
2133 works, as required.) An alternative approach would be to look up
2134 the correct default arguments at the call-site, but this approach
2135 is consistent with how implicit instantiations are handled. */
2138 copy_default_args_to_explicit_spec (tree decl)
2143 tree new_spec_types;
2147 tree object_type = NULL_TREE;
2148 tree in_charge = NULL_TREE;
2149 tree vtt = NULL_TREE;
2151 /* See if there's anything we need to do. */
2152 tmpl = DECL_TI_TEMPLATE (decl);
2153 tmpl_types = TYPE_ARG_TYPES (TREE_TYPE (DECL_TEMPLATE_RESULT (tmpl)));
2154 for (t = tmpl_types; t; t = TREE_CHAIN (t))
2155 if (TREE_PURPOSE (t))
2160 old_type = TREE_TYPE (decl);
2161 spec_types = TYPE_ARG_TYPES (old_type);
2163 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2165 /* Remove the this pointer, but remember the object's type for
2167 object_type = TREE_TYPE (TREE_VALUE (spec_types));
2168 spec_types = TREE_CHAIN (spec_types);
2169 tmpl_types = TREE_CHAIN (tmpl_types);
2171 if (DECL_HAS_IN_CHARGE_PARM_P (decl))
2173 /* DECL may contain more parameters than TMPL due to the extra
2174 in-charge parameter in constructors and destructors. */
2175 in_charge = spec_types;
2176 spec_types = TREE_CHAIN (spec_types);
2178 if (DECL_HAS_VTT_PARM_P (decl))
2181 spec_types = TREE_CHAIN (spec_types);
2185 /* Compute the merged default arguments. */
2187 copy_default_args_to_explicit_spec_1 (spec_types, tmpl_types);
2189 /* Compute the new FUNCTION_TYPE. */
2193 new_spec_types = hash_tree_cons (TREE_PURPOSE (vtt),
2198 /* Put the in-charge parameter back. */
2199 new_spec_types = hash_tree_cons (TREE_PURPOSE (in_charge),
2200 TREE_VALUE (in_charge),
2203 new_type = build_method_type_directly (object_type,
2204 TREE_TYPE (old_type),
2208 new_type = build_function_type (TREE_TYPE (old_type),
2210 new_type = cp_build_type_attribute_variant (new_type,
2211 TYPE_ATTRIBUTES (old_type));
2212 new_type = build_exception_variant (new_type,
2213 TYPE_RAISES_EXCEPTIONS (old_type));
2214 TREE_TYPE (decl) = new_type;
2217 /* Check to see if the function just declared, as indicated in
2218 DECLARATOR, and in DECL, is a specialization of a function
2219 template. We may also discover that the declaration is an explicit
2220 instantiation at this point.
2222 Returns DECL, or an equivalent declaration that should be used
2223 instead if all goes well. Issues an error message if something is
2224 amiss. Returns error_mark_node if the error is not easily
2227 FLAGS is a bitmask consisting of the following flags:
2229 2: The function has a definition.
2230 4: The function is a friend.
2232 The TEMPLATE_COUNT is the number of references to qualifying
2233 template classes that appeared in the name of the function. For
2236 template <class T> struct S { void f(); };
2239 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2240 classes are not counted in the TEMPLATE_COUNT, so that in
2242 template <class T> struct S {};
2243 template <> struct S<int> { void f(); }
2244 template <> void S<int>::f();
2246 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2247 invalid; there should be no template <>.)
2249 If the function is a specialization, it is marked as such via
2250 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2251 is set up correctly, and it is added to the list of specializations
2252 for that template. */
2255 check_explicit_specialization (tree declarator,
2260 int have_def = flags & 2;
2261 int is_friend = flags & 4;
2262 int specialization = 0;
2263 int explicit_instantiation = 0;
2264 int member_specialization = 0;
2265 tree ctype = DECL_CLASS_CONTEXT (decl);
2266 tree dname = DECL_NAME (decl);
2271 if (!processing_specialization)
2274 tsk = tsk_excessive_parms;
2277 tsk = current_tmpl_spec_kind (template_count);
2282 if (processing_specialization)
2285 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2287 else if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2290 /* This could be something like:
2292 template <class T> void f(T);
2293 class S { friend void f<>(int); } */
2297 /* This case handles bogus declarations like template <>
2298 template <class T> void f<int>(); */
2300 error ("template-id %qD in declaration of primary template",
2307 case tsk_invalid_member_spec:
2308 /* The error has already been reported in
2309 check_specialization_scope. */
2310 return error_mark_node;
2312 case tsk_invalid_expl_inst:
2313 error ("template parameter list used in explicit instantiation");
2319 error ("definition provided for explicit instantiation");
2321 explicit_instantiation = 1;
2324 case tsk_excessive_parms:
2325 case tsk_insufficient_parms:
2326 if (tsk == tsk_excessive_parms)
2327 error ("too many template parameter lists in declaration of %qD",
2329 else if (template_header_count)
2330 error("too few template parameter lists in declaration of %qD", decl);
2332 error("explicit specialization of %qD must be introduced by "
2333 "%<template <>%>", decl);
2337 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2339 member_specialization = 1;
2345 if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2347 /* This case handles bogus declarations like template <>
2348 template <class T> void f<int>(); */
2350 if (uses_template_parms (declarator))
2351 error ("function template partial specialization %qD "
2352 "is not allowed", declarator);
2354 error ("template-id %qD in declaration of primary template",
2359 if (ctype && CLASSTYPE_TEMPLATE_INSTANTIATION (ctype))
2360 /* This is a specialization of a member template, without
2361 specialization the containing class. Something like:
2363 template <class T> struct S {
2364 template <class U> void f (U);
2366 template <> template <class U> void S<int>::f(U) {}
2368 That's a specialization -- but of the entire template. */
2376 if (specialization || member_specialization)
2378 tree t = TYPE_ARG_TYPES (TREE_TYPE (decl));
2379 for (; t; t = TREE_CHAIN (t))
2380 if (TREE_PURPOSE (t))
2382 permerror (input_location,
2383 "default argument specified in explicit specialization");
2388 if (specialization || member_specialization || explicit_instantiation)
2390 tree tmpl = NULL_TREE;
2391 tree targs = NULL_TREE;
2393 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2394 if (TREE_CODE (declarator) != TEMPLATE_ID_EXPR)
2398 gcc_assert (TREE_CODE (declarator) == IDENTIFIER_NODE);
2403 /* If there is no class context, the explicit instantiation
2404 must be at namespace scope. */
2405 gcc_assert (DECL_NAMESPACE_SCOPE_P (decl));
2407 /* Find the namespace binding, using the declaration
2409 fns = lookup_qualified_name (CP_DECL_CONTEXT (decl), dname,
2411 if (fns == error_mark_node || !is_overloaded_fn (fns))
2413 error ("%qD is not a template function", dname);
2414 fns = error_mark_node;
2418 tree fn = OVL_CURRENT (fns);
2419 if (!is_associated_namespace (CP_DECL_CONTEXT (decl),
2420 CP_DECL_CONTEXT (fn)))
2421 error ("%qD is not declared in %qD",
2422 decl, current_namespace);
2426 declarator = lookup_template_function (fns, NULL_TREE);
2429 if (declarator == error_mark_node)
2430 return error_mark_node;
2432 if (ctype != NULL_TREE && TYPE_BEING_DEFINED (ctype))
2434 if (!explicit_instantiation)
2435 /* A specialization in class scope. This is invalid,
2436 but the error will already have been flagged by
2437 check_specialization_scope. */
2438 return error_mark_node;
2441 /* It's not valid to write an explicit instantiation in
2444 class C { template void f(); }
2446 This case is caught by the parser. However, on
2449 template class C { void f(); };
2451 (which is invalid) we can get here. The error will be
2458 else if (ctype != NULL_TREE
2459 && (TREE_CODE (TREE_OPERAND (declarator, 0)) ==
2462 /* Find the list of functions in ctype that have the same
2463 name as the declared function. */
2464 tree name = TREE_OPERAND (declarator, 0);
2465 tree fns = NULL_TREE;
2468 if (constructor_name_p (name, ctype))
2470 int is_constructor = DECL_CONSTRUCTOR_P (decl);
2472 if (is_constructor ? !TYPE_HAS_USER_CONSTRUCTOR (ctype)
2473 : !CLASSTYPE_DESTRUCTORS (ctype))
2475 /* From [temp.expl.spec]:
2477 If such an explicit specialization for the member
2478 of a class template names an implicitly-declared
2479 special member function (clause _special_), the
2480 program is ill-formed.
2482 Similar language is found in [temp.explicit]. */
2483 error ("specialization of implicitly-declared special member function");
2484 return error_mark_node;
2487 name = is_constructor ? ctor_identifier : dtor_identifier;
2490 if (!DECL_CONV_FN_P (decl))
2492 idx = lookup_fnfields_1 (ctype, name);
2494 fns = VEC_index (tree, CLASSTYPE_METHOD_VEC (ctype), idx);
2498 VEC(tree,gc) *methods;
2501 /* For a type-conversion operator, we cannot do a
2502 name-based lookup. We might be looking for `operator
2503 int' which will be a specialization of `operator T'.
2504 So, we find *all* the conversion operators, and then
2505 select from them. */
2508 methods = CLASSTYPE_METHOD_VEC (ctype);
2510 for (idx = CLASSTYPE_FIRST_CONVERSION_SLOT;
2511 VEC_iterate (tree, methods, idx, ovl);
2514 if (!DECL_CONV_FN_P (OVL_CURRENT (ovl)))
2515 /* There are no more conversion functions. */
2518 /* Glue all these conversion functions together
2519 with those we already have. */
2520 for (; ovl; ovl = OVL_NEXT (ovl))
2521 fns = ovl_cons (OVL_CURRENT (ovl), fns);
2525 if (fns == NULL_TREE)
2527 error ("no member function %qD declared in %qT", name, ctype);
2528 return error_mark_node;
2531 TREE_OPERAND (declarator, 0) = fns;
2534 /* Figure out what exactly is being specialized at this point.
2535 Note that for an explicit instantiation, even one for a
2536 member function, we cannot tell apriori whether the
2537 instantiation is for a member template, or just a member
2538 function of a template class. Even if a member template is
2539 being instantiated, the member template arguments may be
2540 elided if they can be deduced from the rest of the
2542 tmpl = determine_specialization (declarator, decl,
2544 member_specialization,
2548 if (!tmpl || tmpl == error_mark_node)
2549 /* We couldn't figure out what this declaration was
2551 return error_mark_node;
2554 tree gen_tmpl = most_general_template (tmpl);
2556 if (explicit_instantiation)
2558 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2559 is done by do_decl_instantiation later. */
2561 int arg_depth = TMPL_ARGS_DEPTH (targs);
2562 int parm_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
2564 if (arg_depth > parm_depth)
2566 /* If TMPL is not the most general template (for
2567 example, if TMPL is a friend template that is
2568 injected into namespace scope), then there will
2569 be too many levels of TARGS. Remove some of them
2574 new_targs = make_tree_vec (parm_depth);
2575 for (i = arg_depth - parm_depth; i < arg_depth; ++i)
2576 TREE_VEC_ELT (new_targs, i - (arg_depth - parm_depth))
2577 = TREE_VEC_ELT (targs, i);
2581 return instantiate_template (tmpl, targs, tf_error);
2584 /* If we thought that the DECL was a member function, but it
2585 turns out to be specializing a static member function,
2586 make DECL a static member function as well. */
2587 if (DECL_STATIC_FUNCTION_P (tmpl)
2588 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2589 revert_static_member_fn (decl);
2591 /* If this is a specialization of a member template of a
2592 template class, we want to return the TEMPLATE_DECL, not
2593 the specialization of it. */
2594 if (tsk == tsk_template)
2596 tree result = DECL_TEMPLATE_RESULT (tmpl);
2597 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
2598 DECL_INITIAL (result) = NULL_TREE;
2602 DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl);
2603 DECL_SOURCE_LOCATION (result)
2604 = DECL_SOURCE_LOCATION (decl);
2605 /* We want to use the argument list specified in the
2606 definition, not in the original declaration. */
2607 DECL_ARGUMENTS (result) = DECL_ARGUMENTS (decl);
2608 for (parm = DECL_ARGUMENTS (result); parm;
2609 parm = DECL_CHAIN (parm))
2610 DECL_CONTEXT (parm) = result;
2612 return register_specialization (tmpl, gen_tmpl, targs,
2616 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2617 DECL_TEMPLATE_INFO (decl) = build_template_info (tmpl, targs);
2619 /* Inherit default function arguments from the template
2620 DECL is specializing. */
2621 copy_default_args_to_explicit_spec (decl);
2623 /* This specialization has the same protection as the
2624 template it specializes. */
2625 TREE_PRIVATE (decl) = TREE_PRIVATE (gen_tmpl);
2626 TREE_PROTECTED (decl) = TREE_PROTECTED (gen_tmpl);
2628 /* 7.1.1-1 [dcl.stc]
2630 A storage-class-specifier shall not be specified in an
2631 explicit specialization...
2633 The parser rejects these, so unless action is taken here,
2634 explicit function specializations will always appear with
2637 The action recommended by the C++ CWG in response to C++
2638 defect report 605 is to make the storage class and linkage
2639 of the explicit specialization match the templated function:
2641 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2643 if (tsk == tsk_expl_spec && DECL_FUNCTION_TEMPLATE_P (gen_tmpl))
2645 tree tmpl_func = DECL_TEMPLATE_RESULT (gen_tmpl);
2646 gcc_assert (TREE_CODE (tmpl_func) == FUNCTION_DECL);
2648 /* This specialization has the same linkage and visibility as
2649 the function template it specializes. */
2650 TREE_PUBLIC (decl) = TREE_PUBLIC (tmpl_func);
2651 if (! TREE_PUBLIC (decl))
2653 DECL_INTERFACE_KNOWN (decl) = 1;
2654 DECL_NOT_REALLY_EXTERN (decl) = 1;
2656 DECL_THIS_STATIC (decl) = DECL_THIS_STATIC (tmpl_func);
2657 if (DECL_VISIBILITY_SPECIFIED (tmpl_func))
2659 DECL_VISIBILITY_SPECIFIED (decl) = 1;
2660 DECL_VISIBILITY (decl) = DECL_VISIBILITY (tmpl_func);
2664 /* If DECL is a friend declaration, declared using an
2665 unqualified name, the namespace associated with DECL may
2666 have been set incorrectly. For example, in:
2668 template <typename T> void f(T);
2670 struct S { friend void f<int>(int); }
2673 we will have set the DECL_CONTEXT for the friend
2674 declaration to N, rather than to the global namespace. */
2675 if (DECL_NAMESPACE_SCOPE_P (decl))
2676 DECL_CONTEXT (decl) = DECL_CONTEXT (tmpl);
2678 if (is_friend && !have_def)
2679 /* This is not really a declaration of a specialization.
2680 It's just the name of an instantiation. But, it's not
2681 a request for an instantiation, either. */
2682 SET_DECL_IMPLICIT_INSTANTIATION (decl);
2683 else if (DECL_CONSTRUCTOR_P (decl) || DECL_DESTRUCTOR_P (decl))
2684 /* This is indeed a specialization. In case of constructors
2685 and destructors, we need in-charge and not-in-charge
2686 versions in V3 ABI. */
2687 clone_function_decl (decl, /*update_method_vec_p=*/0);
2689 /* Register this specialization so that we can find it
2691 decl = register_specialization (decl, gen_tmpl, targs, is_friend, 0);
2698 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2699 parameters. These are represented in the same format used for
2700 DECL_TEMPLATE_PARMS. */
2703 comp_template_parms (const_tree parms1, const_tree parms2)
2708 if (parms1 == parms2)
2711 for (p1 = parms1, p2 = parms2;
2712 p1 != NULL_TREE && p2 != NULL_TREE;
2713 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2))
2715 tree t1 = TREE_VALUE (p1);
2716 tree t2 = TREE_VALUE (p2);
2719 gcc_assert (TREE_CODE (t1) == TREE_VEC);
2720 gcc_assert (TREE_CODE (t2) == TREE_VEC);
2722 if (TREE_VEC_LENGTH (t1) != TREE_VEC_LENGTH (t2))
2725 for (i = 0; i < TREE_VEC_LENGTH (t2); ++i)
2727 tree parm1 = TREE_VALUE (TREE_VEC_ELT (t1, i));
2728 tree parm2 = TREE_VALUE (TREE_VEC_ELT (t2, i));
2730 /* If either of the template parameters are invalid, assume
2731 they match for the sake of error recovery. */
2732 if (parm1 == error_mark_node || parm2 == error_mark_node)
2735 if (TREE_CODE (parm1) != TREE_CODE (parm2))
2738 if (TREE_CODE (parm1) == TEMPLATE_TYPE_PARM
2739 && (TEMPLATE_TYPE_PARAMETER_PACK (parm1)
2740 == TEMPLATE_TYPE_PARAMETER_PACK (parm2)))
2742 else if (!same_type_p (TREE_TYPE (parm1), TREE_TYPE (parm2)))
2747 if ((p1 != NULL_TREE) != (p2 != NULL_TREE))
2748 /* One set of parameters has more parameters lists than the
2755 /* Determine whether PARM is a parameter pack. */
2758 template_parameter_pack_p (const_tree parm)
2760 /* Determine if we have a non-type template parameter pack. */
2761 if (TREE_CODE (parm) == PARM_DECL)
2762 return (DECL_TEMPLATE_PARM_P (parm)
2763 && TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)));
2764 if (TREE_CODE (parm) == TEMPLATE_PARM_INDEX)
2765 return TEMPLATE_PARM_PARAMETER_PACK (parm);
2767 /* If this is a list of template parameters, we could get a
2768 TYPE_DECL or a TEMPLATE_DECL. */
2769 if (TREE_CODE (parm) == TYPE_DECL || TREE_CODE (parm) == TEMPLATE_DECL)
2770 parm = TREE_TYPE (parm);
2772 /* Otherwise it must be a type template parameter. */
2773 return ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
2774 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM)
2775 && TEMPLATE_TYPE_PARAMETER_PACK (parm));
2778 /* Determine if T is a function parameter pack. */
2781 function_parameter_pack_p (const_tree t)
2783 if (t && TREE_CODE (t) == PARM_DECL)
2784 return FUNCTION_PARAMETER_PACK_P (t);
2788 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2789 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2792 get_function_template_decl (const_tree primary_func_tmpl_inst)
2794 if (! primary_func_tmpl_inst
2795 || TREE_CODE (primary_func_tmpl_inst) != FUNCTION_DECL
2796 || ! primary_template_instantiation_p (primary_func_tmpl_inst))
2799 return DECL_TEMPLATE_RESULT (DECL_TI_TEMPLATE (primary_func_tmpl_inst));
2802 /* Return true iff the function parameter PARAM_DECL was expanded
2803 from the function parameter pack PACK. */
2806 function_parameter_expanded_from_pack_p (tree param_decl, tree pack)
2808 if (DECL_ARTIFICIAL (param_decl)
2809 || !function_parameter_pack_p (pack))
2812 /* The parameter pack and its pack arguments have the same
2814 return DECL_PARM_INDEX (pack) == DECL_PARM_INDEX (param_decl);
2817 /* Determine whether ARGS describes a variadic template args list,
2818 i.e., one that is terminated by a template argument pack. */
2821 template_args_variadic_p (tree args)
2826 if (args == NULL_TREE)
2829 args = INNERMOST_TEMPLATE_ARGS (args);
2830 nargs = TREE_VEC_LENGTH (args);
2835 last_parm = TREE_VEC_ELT (args, nargs - 1);
2837 return ARGUMENT_PACK_P (last_parm);
2840 /* Generate a new name for the parameter pack name NAME (an
2841 IDENTIFIER_NODE) that incorporates its */
2844 make_ith_pack_parameter_name (tree name, int i)
2846 /* Munge the name to include the parameter index. */
2847 #define NUMBUF_LEN 128
2848 char numbuf[NUMBUF_LEN];
2852 snprintf (numbuf, NUMBUF_LEN, "%i", i);
2853 newname_len = IDENTIFIER_LENGTH (name)
2854 + strlen (numbuf) + 2;
2855 newname = (char*)alloca (newname_len);
2856 snprintf (newname, newname_len,
2857 "%s#%i", IDENTIFIER_POINTER (name), i);
2858 return get_identifier (newname);
2861 /* Return true if T is a primary function, class or alias template
2865 primary_template_instantiation_p (const_tree t)
2870 if (TREE_CODE (t) == FUNCTION_DECL)
2871 return DECL_LANG_SPECIFIC (t)
2872 && DECL_TEMPLATE_INSTANTIATION (t)
2873 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (t));
2874 else if (CLASS_TYPE_P (t) && !TYPE_DECL_ALIAS_P (TYPE_NAME (t)))
2875 return CLASSTYPE_TEMPLATE_INSTANTIATION (t)
2876 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (t));
2878 && TYPE_TEMPLATE_INFO (t)
2879 && PRIMARY_TEMPLATE_P (TYPE_TI_TEMPLATE (t))
2880 && DECL_TEMPLATE_INSTANTIATION (TYPE_NAME (t)))
2885 /* Return true if PARM is a template template parameter. */
2888 template_template_parameter_p (const_tree parm)
2890 return DECL_TEMPLATE_TEMPLATE_PARM_P (parm);
2893 /* Return the template parameters of T if T is a
2894 primary template instantiation, NULL otherwise. */
2897 get_primary_template_innermost_parameters (const_tree t)
2899 tree parms = NULL, template_info = NULL;
2901 if ((template_info = get_template_info (t))
2902 && primary_template_instantiation_p (t))
2903 parms = INNERMOST_TEMPLATE_PARMS
2904 (DECL_TEMPLATE_PARMS (TI_TEMPLATE (template_info)));
2909 /* Return the template parameters of the LEVELth level from the full list
2910 of template parameters PARMS. */
2913 get_template_parms_at_level (tree parms, int level)
2917 || TREE_CODE (parms) != TREE_LIST
2918 || level > TMPL_PARMS_DEPTH (parms))
2921 for (p = parms; p; p = TREE_CHAIN (p))
2922 if (TMPL_PARMS_DEPTH (p) == level)
2928 /* Returns the template arguments of T if T is a template instantiation,
2932 get_template_innermost_arguments (const_tree t)
2934 tree args = NULL, template_info = NULL;
2936 if ((template_info = get_template_info (t))
2937 && TI_ARGS (template_info))
2938 args = INNERMOST_TEMPLATE_ARGS (TI_ARGS (template_info));
2943 /* Return the argument pack elements of T if T is a template argument pack,
2947 get_template_argument_pack_elems (const_tree t)
2949 if (TREE_CODE (t) != TYPE_ARGUMENT_PACK
2950 && TREE_CODE (t) != NONTYPE_ARGUMENT_PACK)
2953 return ARGUMENT_PACK_ARGS (t);
2956 /* Structure used to track the progress of find_parameter_packs_r. */
2957 struct find_parameter_pack_data
2959 /* TREE_LIST that will contain all of the parameter packs found by
2961 tree* parameter_packs;
2963 /* Set of AST nodes that have been visited by the traversal. */
2964 struct pointer_set_t *visited;
2967 /* Identifies all of the argument packs that occur in a template
2968 argument and appends them to the TREE_LIST inside DATA, which is a
2969 find_parameter_pack_data structure. This is a subroutine of
2970 make_pack_expansion and uses_parameter_packs. */
2972 find_parameter_packs_r (tree *tp, int *walk_subtrees, void* data)
2975 struct find_parameter_pack_data* ppd =
2976 (struct find_parameter_pack_data*)data;
2977 bool parameter_pack_p = false;
2979 /* Handle type aliases/typedefs. */
2982 && TREE_CODE (TYPE_NAME (t)) == TYPE_DECL
2983 && TYPE_DECL_ALIAS_P (TYPE_NAME (t)))
2985 if (TYPE_TEMPLATE_INFO (t))
2986 cp_walk_tree (&TYPE_TI_ARGS (t),
2987 &find_parameter_packs_r,
2993 /* Identify whether this is a parameter pack or not. */
2994 switch (TREE_CODE (t))
2996 case TEMPLATE_PARM_INDEX:
2997 if (TEMPLATE_PARM_PARAMETER_PACK (t))
2998 parameter_pack_p = true;
3001 case TEMPLATE_TYPE_PARM:
3002 t = TYPE_MAIN_VARIANT (t);
3003 case TEMPLATE_TEMPLATE_PARM:
3004 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
3005 parameter_pack_p = true;
3009 if (FUNCTION_PARAMETER_PACK_P (t))
3011 /* We don't want to walk into the type of a PARM_DECL,
3012 because we don't want to see the type parameter pack. */
3014 parameter_pack_p = true;
3019 parameter_pack_p = true;
3022 /* Not a parameter pack. */
3026 if (parameter_pack_p)
3028 /* Add this parameter pack to the list. */
3029 *ppd->parameter_packs = tree_cons (NULL_TREE, t, *ppd->parameter_packs);
3033 cp_walk_tree (&TYPE_CONTEXT (t),
3034 &find_parameter_packs_r, ppd, ppd->visited);
3036 /* This switch statement will return immediately if we don't find a
3038 switch (TREE_CODE (t))
3040 case TEMPLATE_PARM_INDEX:
3043 case BOUND_TEMPLATE_TEMPLATE_PARM:
3044 /* Check the template itself. */
3045 cp_walk_tree (&TREE_TYPE (TYPE_TI_TEMPLATE (t)),
3046 &find_parameter_packs_r, ppd, ppd->visited);
3047 /* Check the template arguments. */
3048 cp_walk_tree (&TYPE_TI_ARGS (t), &find_parameter_packs_r, ppd,
3053 case TEMPLATE_TYPE_PARM:
3054 case TEMPLATE_TEMPLATE_PARM:
3061 if (TYPE_PTRMEMFUNC_P (t))
3067 if (TYPE_TEMPLATE_INFO (t))
3068 cp_walk_tree (&TI_ARGS (TYPE_TEMPLATE_INFO (t)),
3069 &find_parameter_packs_r, ppd, ppd->visited);
3076 cp_walk_tree (&TREE_TYPE (t),
3077 &find_parameter_packs_r, ppd, ppd->visited);
3081 cp_walk_tree (&TYPENAME_TYPE_FULLNAME (t), &find_parameter_packs_r,
3086 case TYPE_PACK_EXPANSION:
3087 case EXPR_PACK_EXPANSION:
3092 cp_walk_tree (&TYPE_MAX_VALUE (t), &find_parameter_packs_r,
3097 case IDENTIFIER_NODE:
3098 cp_walk_tree (&TREE_TYPE (t), &find_parameter_packs_r, ppd,
3110 /* Determines if the expression or type T uses any parameter packs. */
3112 uses_parameter_packs (tree t)
3114 tree parameter_packs = NULL_TREE;
3115 struct find_parameter_pack_data ppd;
3116 ppd.parameter_packs = ¶meter_packs;
3117 ppd.visited = pointer_set_create ();
3118 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
3119 pointer_set_destroy (ppd.visited);
3120 return parameter_packs != NULL_TREE;
3123 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3124 representation a base-class initializer into a parameter pack
3125 expansion. If all goes well, the resulting node will be an
3126 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3129 make_pack_expansion (tree arg)
3132 tree parameter_packs = NULL_TREE;
3133 bool for_types = false;
3134 struct find_parameter_pack_data ppd;
3136 if (!arg || arg == error_mark_node)
3139 if (TREE_CODE (arg) == TREE_LIST)
3141 /* The only time we will see a TREE_LIST here is for a base
3142 class initializer. In this case, the TREE_PURPOSE will be a
3143 _TYPE node (representing the base class expansion we're
3144 initializing) and the TREE_VALUE will be a TREE_LIST
3145 containing the initialization arguments.
3147 The resulting expansion looks somewhat different from most
3148 expansions. Rather than returning just one _EXPANSION, we
3149 return a TREE_LIST whose TREE_PURPOSE is a
3150 TYPE_PACK_EXPANSION containing the bases that will be
3151 initialized. The TREE_VALUE will be identical to the
3152 original TREE_VALUE, which is a list of arguments that will
3153 be passed to each base. We do not introduce any new pack
3154 expansion nodes into the TREE_VALUE (although it is possible
3155 that some already exist), because the TREE_PURPOSE and
3156 TREE_VALUE all need to be expanded together with the same
3157 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3158 resulting TREE_PURPOSE will mention the parameter packs in
3159 both the bases and the arguments to the bases. */
3162 tree parameter_packs = NULL_TREE;
3164 /* Determine which parameter packs will be used by the base
3166 ppd.visited = pointer_set_create ();
3167 ppd.parameter_packs = ¶meter_packs;
3168 cp_walk_tree (&TREE_PURPOSE (arg), &find_parameter_packs_r,
3171 if (parameter_packs == NULL_TREE)
3173 error ("base initializer expansion %<%T%> contains no parameter packs", arg);
3174 pointer_set_destroy (ppd.visited);
3175 return error_mark_node;
3178 if (TREE_VALUE (arg) != void_type_node)
3180 /* Collect the sets of parameter packs used in each of the
3181 initialization arguments. */
3182 for (value = TREE_VALUE (arg); value; value = TREE_CHAIN (value))
3184 /* Determine which parameter packs will be expanded in this
3186 cp_walk_tree (&TREE_VALUE (value), &find_parameter_packs_r,
3191 pointer_set_destroy (ppd.visited);
3193 /* Create the pack expansion type for the base type. */
3194 purpose = cxx_make_type (TYPE_PACK_EXPANSION);
3195 SET_PACK_EXPANSION_PATTERN (purpose, TREE_PURPOSE (arg));
3196 PACK_EXPANSION_PARAMETER_PACKS (purpose) = parameter_packs;
3198 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3199 they will rarely be compared to anything. */
3200 SET_TYPE_STRUCTURAL_EQUALITY (purpose);
3202 return tree_cons (purpose, TREE_VALUE (arg), NULL_TREE);
3205 if (TYPE_P (arg) || TREE_CODE (arg) == TEMPLATE_DECL)
3208 /* Build the PACK_EXPANSION_* node. */
3210 ? cxx_make_type (TYPE_PACK_EXPANSION)
3211 : make_node (EXPR_PACK_EXPANSION);
3212 SET_PACK_EXPANSION_PATTERN (result, arg);
3213 if (TREE_CODE (result) == EXPR_PACK_EXPANSION)
3215 /* Propagate type and const-expression information. */
3216 TREE_TYPE (result) = TREE_TYPE (arg);
3217 TREE_CONSTANT (result) = TREE_CONSTANT (arg);
3220 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3221 they will rarely be compared to anything. */
3222 SET_TYPE_STRUCTURAL_EQUALITY (result);
3224 /* Determine which parameter packs will be expanded. */
3225 ppd.parameter_packs = ¶meter_packs;
3226 ppd.visited = pointer_set_create ();
3227 cp_walk_tree (&arg, &find_parameter_packs_r, &ppd, ppd.visited);
3228 pointer_set_destroy (ppd.visited);
3230 /* Make sure we found some parameter packs. */
3231 if (parameter_packs == NULL_TREE)
3234 error ("expansion pattern %<%T%> contains no argument packs", arg);
3236 error ("expansion pattern %<%E%> contains no argument packs", arg);
3237 return error_mark_node;
3239 PACK_EXPANSION_PARAMETER_PACKS (result) = parameter_packs;
3241 PACK_EXPANSION_LOCAL_P (result) = at_function_scope_p ();
3246 /* Checks T for any "bare" parameter packs, which have not yet been
3247 expanded, and issues an error if any are found. This operation can
3248 only be done on full expressions or types (e.g., an expression
3249 statement, "if" condition, etc.), because we could have expressions like:
3251 foo(f(g(h(args)))...)
3253 where "args" is a parameter pack. check_for_bare_parameter_packs
3254 should not be called for the subexpressions args, h(args),
3255 g(h(args)), or f(g(h(args))), because we would produce erroneous
3258 Returns TRUE and emits an error if there were bare parameter packs,
3259 returns FALSE otherwise. */
3261 check_for_bare_parameter_packs (tree t)
3263 tree parameter_packs = NULL_TREE;
3264 struct find_parameter_pack_data ppd;
3266 if (!processing_template_decl || !t || t == error_mark_node)
3269 if (TREE_CODE (t) == TYPE_DECL)
3272 ppd.parameter_packs = ¶meter_packs;
3273 ppd.visited = pointer_set_create ();
3274 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
3275 pointer_set_destroy (ppd.visited);
3277 if (parameter_packs)
3279 error ("parameter packs not expanded with %<...%>:");
3280 while (parameter_packs)
3282 tree pack = TREE_VALUE (parameter_packs);
3283 tree name = NULL_TREE;
3285 if (TREE_CODE (pack) == TEMPLATE_TYPE_PARM
3286 || TREE_CODE (pack) == TEMPLATE_TEMPLATE_PARM)
3287 name = TYPE_NAME (pack);
3288 else if (TREE_CODE (pack) == TEMPLATE_PARM_INDEX)
3289 name = DECL_NAME (TEMPLATE_PARM_DECL (pack));
3291 name = DECL_NAME (pack);
3294 inform (input_location, " %qD", name);
3296 inform (input_location, " <anonymous>");
3298 parameter_packs = TREE_CHAIN (parameter_packs);
3307 /* Expand any parameter packs that occur in the template arguments in
3310 expand_template_argument_pack (tree args)
3312 tree result_args = NULL_TREE;
3313 int in_arg, out_arg = 0, nargs = args ? TREE_VEC_LENGTH (args) : 0;
3314 int num_result_args = -1;
3315 int non_default_args_count = -1;
3317 /* First, determine if we need to expand anything, and the number of
3318 slots we'll need. */
3319 for (in_arg = 0; in_arg < nargs; ++in_arg)
3321 tree arg = TREE_VEC_ELT (args, in_arg);
3322 if (arg == NULL_TREE)
3324 if (ARGUMENT_PACK_P (arg))
3326 int num_packed = TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg));
3327 if (num_result_args < 0)
3328 num_result_args = in_arg + num_packed;
3330 num_result_args += num_packed;
3334 if (num_result_args >= 0)
3339 /* If no expansion is necessary, we're done. */
3340 if (num_result_args < 0)
3343 /* Expand arguments. */
3344 result_args = make_tree_vec (num_result_args);
3345 if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (args))
3346 non_default_args_count =
3347 GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (args);
3348 for (in_arg = 0; in_arg < nargs; ++in_arg)
3350 tree arg = TREE_VEC_ELT (args, in_arg);
3351 if (ARGUMENT_PACK_P (arg))
3353 tree packed = ARGUMENT_PACK_ARGS (arg);
3354 int i, num_packed = TREE_VEC_LENGTH (packed);
3355 for (i = 0; i < num_packed; ++i, ++out_arg)
3356 TREE_VEC_ELT (result_args, out_arg) = TREE_VEC_ELT(packed, i);
3357 if (non_default_args_count > 0)
3358 non_default_args_count += num_packed;
3362 TREE_VEC_ELT (result_args, out_arg) = arg;
3366 if (non_default_args_count >= 0)
3367 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (result_args, non_default_args_count);
3371 /* Checks if DECL shadows a template parameter.
3373 [temp.local]: A template-parameter shall not be redeclared within its
3374 scope (including nested scopes).
3376 Emits an error and returns TRUE if the DECL shadows a parameter,
3377 returns FALSE otherwise. */
3380 check_template_shadow (tree decl)
3384 /* If we're not in a template, we can't possibly shadow a template
3386 if (!current_template_parms)
3389 /* Figure out what we're shadowing. */
3390 if (TREE_CODE (decl) == OVERLOAD)
3391 decl = OVL_CURRENT (decl);
3392 olddecl = innermost_non_namespace_value (DECL_NAME (decl));
3394 /* If there's no previous binding for this name, we're not shadowing
3395 anything, let alone a template parameter. */
3399 /* If we're not shadowing a template parameter, we're done. Note
3400 that OLDDECL might be an OVERLOAD (or perhaps even an
3401 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3403 if (!DECL_P (olddecl) || !DECL_TEMPLATE_PARM_P (olddecl))
3406 /* We check for decl != olddecl to avoid bogus errors for using a
3407 name inside a class. We check TPFI to avoid duplicate errors for
3408 inline member templates. */
3410 || TEMPLATE_PARMS_FOR_INLINE (current_template_parms))
3413 error ("declaration of %q+#D", decl);
3414 error (" shadows template parm %q+#D", olddecl);
3418 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3419 ORIG_LEVEL, DECL, and TYPE. NUM_SIBLINGS is the total number of
3420 template parameters. */
3423 build_template_parm_index (int index,
3430 tree t = make_node (TEMPLATE_PARM_INDEX);
3431 TEMPLATE_PARM_IDX (t) = index;
3432 TEMPLATE_PARM_LEVEL (t) = level;
3433 TEMPLATE_PARM_ORIG_LEVEL (t) = orig_level;
3434 TEMPLATE_PARM_NUM_SIBLINGS (t) = num_siblings;
3435 TEMPLATE_PARM_DECL (t) = decl;
3436 TREE_TYPE (t) = type;
3437 TREE_CONSTANT (t) = TREE_CONSTANT (decl);
3438 TREE_READONLY (t) = TREE_READONLY (decl);
3443 /* Find the canonical type parameter for the given template type
3444 parameter. Returns the canonical type parameter, which may be TYPE
3445 if no such parameter existed. */
3448 canonical_type_parameter (tree type)
3451 int idx = TEMPLATE_TYPE_IDX (type);
3452 if (!canonical_template_parms)
3453 canonical_template_parms = VEC_alloc (tree, gc, idx+1);
3455 while (VEC_length (tree, canonical_template_parms) <= (unsigned)idx)
3456 VEC_safe_push (tree, gc, canonical_template_parms, NULL_TREE);
3458 list = VEC_index (tree, canonical_template_parms, idx);
3459 while (list && !comptypes (type, TREE_VALUE (list), COMPARE_STRUCTURAL))
3460 list = TREE_CHAIN (list);
3463 return TREE_VALUE (list);
3466 VEC_replace(tree, canonical_template_parms, idx,
3467 tree_cons (NULL_TREE, type,
3468 VEC_index (tree, canonical_template_parms, idx)));
3473 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3474 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3475 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3476 new one is created. */
3479 reduce_template_parm_level (tree index, tree type, int levels, tree args,
3480 tsubst_flags_t complain)
3482 if (TEMPLATE_PARM_DESCENDANTS (index) == NULL_TREE
3483 || (TEMPLATE_PARM_LEVEL (TEMPLATE_PARM_DESCENDANTS (index))
3484 != TEMPLATE_PARM_LEVEL (index) - levels)
3485 || !same_type_p (type, TREE_TYPE (TEMPLATE_PARM_DESCENDANTS (index))))
3487 tree orig_decl = TEMPLATE_PARM_DECL (index);
3490 decl = build_decl (DECL_SOURCE_LOCATION (orig_decl),
3491 TREE_CODE (orig_decl), DECL_NAME (orig_decl), type);
3492 TREE_CONSTANT (decl) = TREE_CONSTANT (orig_decl);
3493 TREE_READONLY (decl) = TREE_READONLY (orig_decl);
3494 DECL_ARTIFICIAL (decl) = 1;
3495 SET_DECL_TEMPLATE_PARM_P (decl);
3497 t = build_template_parm_index (TEMPLATE_PARM_IDX (index),
3498 TEMPLATE_PARM_LEVEL (index) - levels,
3499 TEMPLATE_PARM_ORIG_LEVEL (index),
3500 TEMPLATE_PARM_NUM_SIBLINGS (index),
3502 TEMPLATE_PARM_DESCENDANTS (index) = t;
3503 TEMPLATE_PARM_PARAMETER_PACK (t)
3504 = TEMPLATE_PARM_PARAMETER_PACK (index);
3506 /* Template template parameters need this. */
3507 if (TREE_CODE (decl) == TEMPLATE_DECL)
3508 DECL_TEMPLATE_PARMS (decl) = tsubst_template_parms
3509 (DECL_TEMPLATE_PARMS (TEMPLATE_PARM_DECL (index)),
3513 return TEMPLATE_PARM_DESCENDANTS (index);
3516 /* Process information from new template parameter PARM and append it
3517 to the LIST being built. This new parameter is a non-type
3518 parameter iff IS_NON_TYPE is true. This new parameter is a
3519 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3520 is in PARM_LOC. NUM_TEMPLATE_PARMS is the size of the template
3521 parameter list PARM belongs to. This is used used to create a
3522 proper canonical type for the type of PARM that is to be created,
3523 iff PARM is a type. If the size is not known, this parameter shall
3527 process_template_parm (tree list, location_t parm_loc, tree parm,
3528 bool is_non_type, bool is_parameter_pack,
3529 unsigned num_template_parms)
3536 gcc_assert (TREE_CODE (parm) == TREE_LIST);
3537 defval = TREE_PURPOSE (parm);
3541 tree p = tree_last (list);
3543 if (p && TREE_VALUE (p) != error_mark_node)
3546 if (TREE_CODE (p) == TYPE_DECL || TREE_CODE (p) == TEMPLATE_DECL)
3547 idx = TEMPLATE_TYPE_IDX (TREE_TYPE (p));
3549 idx = TEMPLATE_PARM_IDX (DECL_INITIAL (p));
3559 parm = TREE_VALUE (parm);
3561 SET_DECL_TEMPLATE_PARM_P (parm);
3563 if (TREE_TYPE (parm) == error_mark_node)
3565 err_parm_list = build_tree_list (defval, parm);
3566 TREE_VALUE (err_parm_list) = error_mark_node;
3567 return chainon (list, err_parm_list);
3573 The top-level cv-qualifiers on the template-parameter are
3574 ignored when determining its type. */
3575 TREE_TYPE (parm) = TYPE_MAIN_VARIANT (TREE_TYPE (parm));
3576 if (invalid_nontype_parm_type_p (TREE_TYPE (parm), 1))
3578 err_parm_list = build_tree_list (defval, parm);
3579 TREE_VALUE (err_parm_list) = error_mark_node;
3580 return chainon (list, err_parm_list);
3583 if (uses_parameter_packs (TREE_TYPE (parm)) && !is_parameter_pack)
3585 /* This template parameter is not a parameter pack, but it
3586 should be. Complain about "bare" parameter packs. */
3587 check_for_bare_parameter_packs (TREE_TYPE (parm));
3589 /* Recover by calling this a parameter pack. */
3590 is_parameter_pack = true;
3594 /* A template parameter is not modifiable. */
3595 TREE_CONSTANT (parm) = 1;
3596 TREE_READONLY (parm) = 1;
3597 decl = build_decl (parm_loc,
3598 CONST_DECL, DECL_NAME (parm), TREE_TYPE (parm));
3599 TREE_CONSTANT (decl) = 1;
3600 TREE_READONLY (decl) = 1;
3601 DECL_INITIAL (parm) = DECL_INITIAL (decl)
3602 = build_template_parm_index (idx, processing_template_decl,
3603 processing_template_decl,
3605 decl, TREE_TYPE (parm));
3607 TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))
3608 = is_parameter_pack;
3613 parm = TREE_VALUE (TREE_VALUE (parm));
3615 if (parm && TREE_CODE (parm) == TEMPLATE_DECL)
3617 t = cxx_make_type (TEMPLATE_TEMPLATE_PARM);
3618 /* This is for distinguishing between real templates and template
3619 template parameters */
3620 TREE_TYPE (parm) = t;
3621 TREE_TYPE (DECL_TEMPLATE_RESULT (parm)) = t;
3626 t = cxx_make_type (TEMPLATE_TYPE_PARM);
3627 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3628 decl = build_decl (parm_loc,
3629 TYPE_DECL, parm, t);
3632 TYPE_NAME (t) = decl;
3633 TYPE_STUB_DECL (t) = decl;
3635 TEMPLATE_TYPE_PARM_INDEX (t)
3636 = build_template_parm_index (idx, processing_template_decl,
3637 processing_template_decl,
3639 decl, TREE_TYPE (parm));
3640 TEMPLATE_TYPE_PARAMETER_PACK (t) = is_parameter_pack;
3641 TYPE_CANONICAL (t) = canonical_type_parameter (t);
3643 DECL_ARTIFICIAL (decl) = 1;
3644 SET_DECL_TEMPLATE_PARM_P (decl);
3646 parm = build_tree_list (defval, parm);
3647 return chainon (list, parm);
3650 /* The end of a template parameter list has been reached. Process the
3651 tree list into a parameter vector, converting each parameter into a more
3652 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3656 end_template_parm_list (tree parms)
3660 tree saved_parmlist = make_tree_vec (list_length (parms));
3662 current_template_parms
3663 = tree_cons (size_int (processing_template_decl),
3664 saved_parmlist, current_template_parms);
3666 for (parm = parms, nparms = 0; parm; parm = next, nparms++)
3668 next = TREE_CHAIN (parm);
3669 TREE_VEC_ELT (saved_parmlist, nparms) = parm;
3670 TREE_CHAIN (parm) = NULL_TREE;
3673 --processing_template_parmlist;
3675 return saved_parmlist;
3678 /* Create a new type almost identical to TYPE but which has the
3679 following differences:
3681 1/ T has a new TEMPLATE_PARM_INDEX that carries the new number of
3682 template sibling parameters of T.
3684 2/ T has a new canonical type that matches the new number
3687 3/ From now on, T is going to be what lookups referring to the
3688 name of TYPE will return. No lookup should return TYPE anymore.
3690 NUM_PARMS is the new number of sibling parms TYPE belongs to.
3692 This is a subroutine of fixup_template_parms. */
3695 fixup_template_type_parm_type (tree type, int num_parms)
3697 tree orig_idx = TEMPLATE_TYPE_PARM_INDEX (type), idx;
3699 /* This is the decl which name is inserted into the symbol table for
3700 the template parm type. So whenever we lookup the type name, this
3701 is the DECL we get. */
3704 /* Do not fix up the type twice. */
3705 if (orig_idx && TEMPLATE_PARM_NUM_SIBLINGS (orig_idx) != 0)
3708 t = copy_type (type);
3709 decl = TYPE_NAME (t);
3711 TYPE_MAIN_VARIANT (t) = t;
3712 TYPE_NEXT_VARIANT (t)= NULL_TREE;
3713 TYPE_POINTER_TO (t) = 0;
3714 TYPE_REFERENCE_TO (t) = 0;
3716 idx = build_template_parm_index (TEMPLATE_PARM_IDX (orig_idx),
3717 TEMPLATE_PARM_LEVEL (orig_idx),
3718 TEMPLATE_PARM_ORIG_LEVEL (orig_idx),
3721 TEMPLATE_PARM_DESCENDANTS (idx) = TEMPLATE_PARM_DESCENDANTS (orig_idx);
3722 TEMPLATE_PARM_PARAMETER_PACK (idx) = TEMPLATE_PARM_PARAMETER_PACK (orig_idx);
3723 TEMPLATE_TYPE_PARM_INDEX (t) = idx;
3725 TYPE_STUB_DECL (t) = decl;
3726 TEMPLATE_TYPE_DECL (t) = decl;
3727 if (TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM)
3728 TREE_TYPE (DECL_TEMPLATE_RESULT (decl)) = t;
3730 /* Update the type associated to the type name stored in the symbol
3731 table. Now, whenever the type name is looked up, the resulting
3732 type is properly fixed up. */
3733 TREE_TYPE (decl) = t;
3735 TYPE_CANONICAL (t) = canonical_type_parameter (t);
3740 /* Create and return a new TEMPLATE_PARM_INDEX that is almost
3741 identical to I, but that is fixed up as to:
3743 1/ carry the number of sibling parms (NUM_PARMS) of the template
3744 parm represented by I.
3746 2/ replace all references to template parm types declared before I
3747 (in the same template parm list as I) by references to template
3748 parm types contained in ARGS. ARGS should contain the list of
3749 template parms that have been fixed up so far, in a form suitable
3750 to be passed to tsubst.
3752 This is a subroutine of fixup_template_parms. */
3755 fixup_template_parm_index (tree i, tree args, int num_parms)
3757 tree index, decl, type;
3760 || TREE_CODE (i) != TEMPLATE_PARM_INDEX
3761 /* Do not fix up the index twice. */
3762 || (TEMPLATE_PARM_NUM_SIBLINGS (i) != 0))
3765 decl = TEMPLATE_PARM_DECL (i);
3766 type = TREE_TYPE (decl);
3768 index = build_template_parm_index (TEMPLATE_PARM_IDX (i),
3769 TEMPLATE_PARM_LEVEL (i),
3770 TEMPLATE_PARM_ORIG_LEVEL (i),
3774 TEMPLATE_PARM_DESCENDANTS (index) = TEMPLATE_PARM_DESCENDANTS (i);
3775 TEMPLATE_PARM_PARAMETER_PACK (index) = TEMPLATE_PARM_PARAMETER_PACK (i);
3777 type = tsubst (type, args, tf_none, NULL_TREE);
3779 TREE_TYPE (decl) = type;
3780 TREE_TYPE (index) = type;
3786 This is a subroutine of fixup_template_parms.
3788 It computes the canonical type of the type of the template
3789 parameter PARM_DESC and update all references to that type so that
3790 they use the newly computed canonical type. No access check is
3791 performed during the fixup. PARM_DESC is a TREE_LIST which
3792 TREE_VALUE is the template parameter and its TREE_PURPOSE is the
3793 default argument of the template parm if any. IDX is the index of
3794 the template parameter, starting at 0. NUM_PARMS is the number of
3795 template parameters in the set PARM_DESC belongs to. ARGLIST is a
3796 TREE_VEC containing the full set of template parameters in a form
3797 suitable to be passed to substs functions as their ARGS
3798 argument. This is what current_template_args returns for a given
3799 template. The innermost vector of args in ARGLIST is the set of
3800 template parms that have been fixed up so far. This function adds
3801 the fixed up parameter into that vector. */
3804 fixup_template_parm (tree parm_desc,
3809 tree parm = TREE_VALUE (parm_desc);
3810 tree fixedup_args = INNERMOST_TEMPLATE_ARGS (arglist);
3812 push_deferring_access_checks (dk_no_check);
3814 if (TREE_CODE (parm) == TYPE_DECL)
3816 /* PARM is a template type parameter. Fix up its type, add
3817 the fixed-up template parm to the vector of fixed-up
3818 template parms so far, and substitute the fixed-up
3819 template parms into the default argument of this
3822 fixup_template_type_parm_type (TREE_TYPE (parm), num_parms);
3823 TREE_TYPE (parm) = t;
3825 TREE_VEC_ELT (fixedup_args, idx) = template_parm_to_arg (parm_desc);
3827 else if (TREE_CODE (parm) == TEMPLATE_DECL)
3829 /* PARM is a template template parameter. This is going to
3831 tree tparms, targs, innermost_args, t;
3834 /* First, fix up the parms of the template template parm
3835 because the parms are involved in defining the new canonical
3836 type of the template template parm. */
3838 /* So we need to substitute the template parm types that have
3839 been fixed up so far into the template parms of this template
3840 template parm. E.g, consider this:
3842 template<class T, template<T u> class TT> class S;
3844 In this case we want to substitute T into the
3845 template parameters of TT.
3847 So let's walk the template parms of PARM here, and
3848 tsubst ARGLIST into into each of the template
3851 /* For this substitution we need to build the full set of
3852 template parameters and use that as arguments for the
3853 tsubsting function. */
3854 tparms = INNERMOST_TEMPLATE_PARMS (DECL_TEMPLATE_PARMS (parm));
3856 /* This will contain the innermost parms of PARM into which
3857 we have substituted so far. */
3858 innermost_args = make_tree_vec (TREE_VEC_LENGTH (tparms));
3859 targs = add_to_template_args (arglist, innermost_args);
3860 for (j = 0; j < TREE_VEC_LENGTH (tparms); ++j)
3864 parameter = TREE_VEC_ELT (tparms, j);
3866 /* INNERMOST_ARGS needs to have at least the same number
3867 of elements as the index PARAMETER, ortherwise
3868 tsubsting into PARAMETER will result in partially
3869 instantiating it, reducing its tempate parm
3870 level. Let's tactically fill INNERMOST_ARGS for that
3872 TREE_VEC_ELT (innermost_args, j) =
3873 template_parm_to_arg (parameter);
3875 fixup_template_parm (parameter, j,
3876 TREE_VEC_LENGTH (tparms),
3880 /* Now fix up the type of the template template parm. */
3882 t = fixup_template_type_parm_type (TREE_TYPE (parm), num_parms);
3883 TREE_TYPE (parm) = t;
3885 TREE_VEC_ELT (fixedup_args, idx) =
3886 template_parm_to_arg (parm_desc);
3888 else if (TREE_CODE (parm) == PARM_DECL)
3890 /* PARM is a non-type template parameter. We need to:
3892 * Fix up its TEMPLATE_PARM_INDEX to make it carry the
3893 proper number of sibling parameters.
3895 * Make lookups of the template parameter return a reference
3896 to the fixed-up index. No lookup should return references
3897 to the former index anymore.
3899 * Substitute the template parms that got fixed up so far
3901 * into the type of PARM. */
3903 tree index = DECL_INITIAL (parm);
3905 /* PUSHED_DECL is the decl added to the symbol table with
3906 the name of the parameter. E,g:
3908 template<class T, T u> //#0
3909 auto my_function(T t) -> decltype(u); //#1
3911 Here, when looking up u at //#1, we get the decl of u
3912 resulting from the declaration in #0. This is what
3913 PUSHED_DECL is. We need to replace the reference to the
3914 old TEMPLATE_PARM_INDEX carried by PUSHED_DECL by the
3915 fixed-up TEMPLATE_PARM_INDEX. */
3916 tree pushed_decl = TEMPLATE_PARM_DECL (index);
3918 /* Let's fix up the TEMPLATE_PARM_INDEX then. Note that we must
3919 fixup the type of PUSHED_DECL as well and luckily
3920 fixup_template_parm_index does it for us too. */
3921 tree fixed_up_index =
3922 fixup_template_parm_index (index, arglist, num_parms);
3924 DECL_INITIAL (pushed_decl) = DECL_INITIAL (parm) = fixed_up_index;
3926 /* Add this fixed up PARM to the template parms we've fixed
3927 up so far and use that to substitute the fixed-up
3928 template parms into the type of PARM. */
3929 TREE_VEC_ELT (fixedup_args, idx) =
3930 template_parm_to_arg (parm_desc);
3931 TREE_TYPE (parm) = tsubst (TREE_TYPE (parm), arglist,
3932 tf_none, NULL_TREE);
3935 TREE_PURPOSE (parm_desc) =
3936 tsubst_template_arg (TREE_PURPOSE (parm_desc),
3937 arglist, tf_none, parm);
3939 pop_deferring_access_checks ();
3942 /* Walk the current template parms and properly compute the canonical
3943 types of the dependent types created during
3944 cp_parser_template_parameter_list. */
3947 fixup_template_parms (void)
3954 parameter_vec = INNERMOST_TEMPLATE_PARMS (current_template_parms);
3955 if (parameter_vec == NULL_TREE)
3958 num_parms = TREE_VEC_LENGTH (parameter_vec);
3960 /* This vector contains the current innermost template parms that
3961 have been fixed up so far. The form of FIXEDUP_ARGS is suitable
3962 to be passed to tsubst* functions as their ARGS argument. */
3963 fixedup_args = make_tree_vec (num_parms);
3965 /* This vector contains the full set of template parms in a form
3966 suitable to be passed to substs functions as their ARGS
3968 arglist = current_template_args ();
3969 arglist = add_outermost_template_args (arglist, fixedup_args);
3971 /* Let's do the proper fixup now. */
3972 for (i = 0; i < num_parms; ++i)
3973 fixup_template_parm (TREE_VEC_ELT (parameter_vec, i),
3974 i, num_parms, arglist);
3977 /* end_template_decl is called after a template declaration is seen. */
3980 end_template_decl (void)
3982 reset_specialization ();
3984 if (! processing_template_decl)
3987 /* This matches the pushlevel in begin_template_parm_list. */
3990 --processing_template_decl;
3991 current_template_parms = TREE_CHAIN (current_template_parms);
3994 /* Takes a TREE_LIST representing a template parameter and convert it
3995 into an argument suitable to be passed to the type substitution
3996 functions. Note that If the TREE_LIST contains an error_mark
3997 node, the returned argument is error_mark_node. */
4000 template_parm_to_arg (tree t)
4004 || TREE_CODE (t) != TREE_LIST)
4007 if (error_operand_p (TREE_VALUE (t)))
4008 return error_mark_node;
4012 if (TREE_CODE (t) == TYPE_DECL
4013 || TREE_CODE (t) == TEMPLATE_DECL)
4017 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
4019 /* Turn this argument into a TYPE_ARGUMENT_PACK
4020 with a single element, which expands T. */
4021 tree vec = make_tree_vec (1);
4022 #ifdef ENABLE_CHECKING
4023 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
4024 (vec, TREE_VEC_LENGTH (vec));
4026 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
4028 t = cxx_make_type (TYPE_ARGUMENT_PACK);
4029 SET_ARGUMENT_PACK_ARGS (t, vec);
4034 t = DECL_INITIAL (t);
4036 if (TEMPLATE_PARM_PARAMETER_PACK (t))
4038 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
4039 with a single element, which expands T. */
4040 tree vec = make_tree_vec (1);
4041 tree type = TREE_TYPE (TEMPLATE_PARM_DECL (t));
4042 #ifdef ENABLE_CHECKING
4043 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
4044 (vec, TREE_VEC_LENGTH (vec));
4046 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
4048 t = make_node (NONTYPE_ARGUMENT_PACK);
4049 SET_ARGUMENT_PACK_ARGS (t, vec);
4050 TREE_TYPE (t) = type;
4056 /* This function returns TRUE if PARM_PACK is a template parameter
4057 pack and if ARG_PACK is what template_parm_to_arg returned when
4058 passed PARM_PACK. */
4061 arg_from_parm_pack_p (tree arg_pack, tree parm_pack)
4063 /* For clarity in the comments below let's use the representation
4064 argument_pack<elements>' to denote an argument pack and its
4067 In the 'if' block below, we want to detect cases where
4068 ARG_PACK is argument_pack<PARM_PACK...>. I.e, we want to
4069 check if ARG_PACK is an argument pack which sole element is
4070 the expansion of PARM_PACK. That argument pack is typically
4071 created by template_parm_to_arg when passed a parameter
4075 && TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack)) == 1
4076 && PACK_EXPANSION_P (TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0)))
4078 tree expansion = TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0);
4079 tree pattern = PACK_EXPANSION_PATTERN (expansion);
4080 /* So we have an argument_pack<P...>. We want to test if P
4081 is actually PARM_PACK. We will not use cp_tree_equal to
4082 test P and PARM_PACK because during type fixup (by
4083 fixup_template_parm) P can be a pre-fixup version of a
4084 type and PARM_PACK be its post-fixup version.
4085 cp_tree_equal would consider them as different even
4086 though we would want to consider them compatible for our
4087 precise purpose here.
4089 Thus we are going to consider that P and PARM_PACK are
4090 compatible if they have the same DECL. */
4091 if ((/* If ARG_PACK is a type parameter pack named by the
4092 same DECL as parm_pack ... */
4094 && TYPE_P (parm_pack)
4095 && TYPE_NAME (pattern) == TYPE_NAME (parm_pack))
4096 /* ... or if PARM_PACK is a non-type parameter named by the
4097 same DECL as ARG_PACK. Note that PARM_PACK being a
4098 non-type parameter means it's either a PARM_DECL or a
4099 TEMPLATE_PARM_INDEX. */
4100 || (TREE_CODE (pattern) == TEMPLATE_PARM_INDEX
4101 && ((TREE_CODE (parm_pack) == PARM_DECL
4102 && (TEMPLATE_PARM_DECL (pattern)
4103 == TEMPLATE_PARM_DECL (DECL_INITIAL (parm_pack))))
4104 || (TREE_CODE (parm_pack) == TEMPLATE_PARM_INDEX
4105 && (TEMPLATE_PARM_DECL (pattern)
4106 == TEMPLATE_PARM_DECL (parm_pack))))))
4107 && template_parameter_pack_p (pattern))
4113 /* Within the declaration of a template, return all levels of template
4114 parameters that apply. The template parameters are represented as
4115 a TREE_VEC, in the form documented in cp-tree.h for template
4119 current_template_args (void)
4122 tree args = NULL_TREE;
4123 int length = TMPL_PARMS_DEPTH (current_template_parms);
4126 /* If there is only one level of template parameters, we do not
4127 create a TREE_VEC of TREE_VECs. Instead, we return a single
4128 TREE_VEC containing the arguments. */
4130 args = make_tree_vec (length);
4132 for (header = current_template_parms; header; header = TREE_CHAIN (header))
4134 tree a = copy_node (TREE_VALUE (header));
4137 TREE_TYPE (a) = NULL_TREE;
4138 for (i = TREE_VEC_LENGTH (a) - 1; i >= 0; --i)
4139 TREE_VEC_ELT (a, i) = template_parm_to_arg (TREE_VEC_ELT (a, i));
4141 #ifdef ENABLE_CHECKING
4142 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (a, TREE_VEC_LENGTH (a));
4146 TREE_VEC_ELT (args, --l) = a;
4151 if (length > 1 && TREE_VEC_ELT (args, 0) == NULL_TREE)
4152 /* This can happen for template parms of a template template
4155 template<template<class T, class U> class TT> struct S;
4157 Consider the level of the parms of TT; T and U both have
4158 level 2; TT has no template parm of level 1. So in this case
4159 the first element of full_template_args is NULL_TREE. If we
4160 leave it like this TMPL_ARG_DEPTH on args returns 1 instead
4161 of 2. This will make tsubst wrongly consider that T and U
4162 have level 1. Instead, let's create a dummy vector as the
4163 first element of full_template_args so that TMPL_ARG_DEPTH
4164 returns the correct depth for args. */
4165 TREE_VEC_ELT (args, 0) = make_tree_vec (1);
4169 /* Update the declared TYPE by doing any lookups which were thought to be
4170 dependent, but are not now that we know the SCOPE of the declarator. */
4173 maybe_update_decl_type (tree orig_type, tree scope)
4175 tree type = orig_type;
4177 if (type == NULL_TREE)
4180 if (TREE_CODE (orig_type) == TYPE_DECL)
4181 type = TREE_TYPE (type);
4183 if (scope && TYPE_P (scope) && dependent_type_p (scope)
4184 && dependent_type_p (type)
4185 /* Don't bother building up the args in this case. */
4186 && TREE_CODE (type) != TEMPLATE_TYPE_PARM)
4188 /* tsubst in the args corresponding to the template parameters,
4189 including auto if present. Most things will be unchanged, but
4190 make_typename_type and tsubst_qualified_id will resolve
4191 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4192 tree args = current_template_args ();
4193 tree auto_node = type_uses_auto (type);
4197 tree auto_vec = make_tree_vec (1);
4198 TREE_VEC_ELT (auto_vec, 0) = auto_node;
4199 args = add_to_template_args (args, auto_vec);
4201 pushed = push_scope (scope);
4202 type = tsubst (type, args, tf_warning_or_error, NULL_TREE);
4207 if (type == error_mark_node)
4210 if (TREE_CODE (orig_type) == TYPE_DECL)
4212 if (same_type_p (type, TREE_TYPE (orig_type)))
4215 type = TYPE_NAME (type);
4220 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4221 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
4222 a member template. Used by push_template_decl below. */
4225 build_template_decl (tree decl, tree parms, bool member_template_p)
4227 tree tmpl = build_lang_decl (TEMPLATE_DECL, DECL_NAME (decl), NULL_TREE);
4228 DECL_TEMPLATE_PARMS (tmpl) = parms;
4229 DECL_CONTEXT (tmpl) = DECL_CONTEXT (decl);
4230 DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl);
4231 DECL_MEMBER_TEMPLATE_P (tmpl) = member_template_p;
4236 struct template_parm_data
4238 /* The level of the template parameters we are currently
4242 /* The index of the specialization argument we are currently
4246 /* An array whose size is the number of template parameters. The
4247 elements are nonzero if the parameter has been used in any one
4248 of the arguments processed so far. */
4251 /* An array whose size is the number of template arguments. The
4252 elements are nonzero if the argument makes use of template
4253 parameters of this level. */
4254 int* arg_uses_template_parms;
4257 /* Subroutine of push_template_decl used to see if each template
4258 parameter in a partial specialization is used in the explicit
4259 argument list. If T is of the LEVEL given in DATA (which is
4260 treated as a template_parm_data*), then DATA->PARMS is marked
4264 mark_template_parm (tree t, void* data)
4268 struct template_parm_data* tpd = (struct template_parm_data*) data;
4270 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
4272 level = TEMPLATE_PARM_LEVEL (t);
4273 idx = TEMPLATE_PARM_IDX (t);
4277 level = TEMPLATE_TYPE_LEVEL (t);
4278 idx = TEMPLATE_TYPE_IDX (t);
4281 if (level == tpd->level)
4283 tpd->parms[idx] = 1;
4284 tpd->arg_uses_template_parms[tpd->current_arg] = 1;
4287 /* Return zero so that for_each_template_parm will continue the
4288 traversal of the tree; we want to mark *every* template parm. */
4292 /* Process the partial specialization DECL. */
4295 process_partial_specialization (tree decl)
4297 tree type = TREE_TYPE (decl);
4298 tree maintmpl = CLASSTYPE_TI_TEMPLATE (type);
4299 tree specargs = CLASSTYPE_TI_ARGS (type);
4300 tree inner_args = INNERMOST_TEMPLATE_ARGS (specargs);
4301 tree main_inner_parms = DECL_INNERMOST_TEMPLATE_PARMS (maintmpl);
4304 int nargs = TREE_VEC_LENGTH (inner_args);
4307 bool did_error_intro = false;
4308 struct template_parm_data tpd;
4309 struct template_parm_data tpd2;
4311 gcc_assert (current_template_parms);
4313 inner_parms = INNERMOST_TEMPLATE_PARMS (current_template_parms);
4314 ntparms = TREE_VEC_LENGTH (inner_parms);
4316 /* We check that each of the template parameters given in the
4317 partial specialization is used in the argument list to the
4318 specialization. For example:
4320 template <class T> struct S;
4321 template <class T> struct S<T*>;
4323 The second declaration is OK because `T*' uses the template
4324 parameter T, whereas
4326 template <class T> struct S<int>;
4328 is no good. Even trickier is:
4339 The S2<T> declaration is actually invalid; it is a
4340 full-specialization. Of course,
4343 struct S2<T (*)(U)>;
4345 or some such would have been OK. */
4346 tpd.level = TMPL_PARMS_DEPTH (current_template_parms);
4347 tpd.parms = XALLOCAVEC (int, ntparms);
4348 memset (tpd.parms, 0, sizeof (int) * ntparms);
4350 tpd.arg_uses_template_parms = XALLOCAVEC (int, nargs);
4351 memset (tpd.arg_uses_template_parms, 0, sizeof (int) * nargs);
4352 for (i = 0; i < nargs; ++i)
4354 tpd.current_arg = i;
4355 for_each_template_parm (TREE_VEC_ELT (inner_args, i),
4356 &mark_template_parm,
4359 /*include_nondeduced_p=*/false);
4361 for (i = 0; i < ntparms; ++i)
4362 if (tpd.parms[i] == 0)
4364 /* One of the template parms was not used in the
4366 if (!did_error_intro)
4368 error ("template parameters not used in partial specialization:");
4369 did_error_intro = true;
4372 error (" %qD", TREE_VALUE (TREE_VEC_ELT (inner_parms, i)));
4375 if (did_error_intro)
4376 return error_mark_node;
4378 /* [temp.class.spec]
4380 The argument list of the specialization shall not be identical to
4381 the implicit argument list of the primary template. */
4382 if (comp_template_args
4384 INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE
4386 error ("partial specialization %qT does not specialize any template arguments", type);
4388 /* [temp.class.spec]
4390 A partially specialized non-type argument expression shall not
4391 involve template parameters of the partial specialization except
4392 when the argument expression is a simple identifier.
4394 The type of a template parameter corresponding to a specialized
4395 non-type argument shall not be dependent on a parameter of the
4398 Also, we verify that pack expansions only occur at the
4399 end of the argument list. */
4400 gcc_assert (nargs == DECL_NTPARMS (maintmpl));
4402 for (i = 0; i < nargs; ++i)
4404 tree parm = TREE_VALUE (TREE_VEC_ELT (main_inner_parms, i));
4405 tree arg = TREE_VEC_ELT (inner_args, i);
4406 tree packed_args = NULL_TREE;
4409 if (ARGUMENT_PACK_P (arg))
4411 /* Extract the arguments from the argument pack. We'll be
4412 iterating over these in the following loop. */
4413 packed_args = ARGUMENT_PACK_ARGS (arg);
4414 len = TREE_VEC_LENGTH (packed_args);
4417 for (j = 0; j < len; j++)
4420 /* Get the Jth argument in the parameter pack. */
4421 arg = TREE_VEC_ELT (packed_args, j);
4423 if (PACK_EXPANSION_P (arg))
4425 /* Pack expansions must come at the end of the
4427 if ((packed_args && j < len - 1)
4428 || (!packed_args && i < nargs - 1))
4430 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
4431 error ("parameter pack argument %qE must be at the "
4432 "end of the template argument list", arg);
4434 error ("parameter pack argument %qT must be at the "
4435 "end of the template argument list", arg);
4439 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
4440 /* We only care about the pattern. */
4441 arg = PACK_EXPANSION_PATTERN (arg);
4443 if (/* These first two lines are the `non-type' bit. */
4445 && TREE_CODE (arg) != TEMPLATE_DECL
4446 /* This next line is the `argument expression is not just a
4447 simple identifier' condition and also the `specialized
4448 non-type argument' bit. */
4449 && TREE_CODE (arg) != TEMPLATE_PARM_INDEX)
4451 if ((!packed_args && tpd.arg_uses_template_parms[i])
4452 || (packed_args && uses_template_parms (arg)))
4453 error ("template argument %qE involves template parameter(s)",
4457 /* Look at the corresponding template parameter,
4458 marking which template parameters its type depends
4460 tree type = TREE_TYPE (parm);
4464 /* We haven't yet initialized TPD2. Do so now. */
4465 tpd2.arg_uses_template_parms = XALLOCAVEC (int, nargs);
4466 /* The number of parameters here is the number in the
4467 main template, which, as checked in the assertion
4469 tpd2.parms = XALLOCAVEC (int, nargs);
4471 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (maintmpl));
4474 /* Mark the template parameters. But this time, we're
4475 looking for the template parameters of the main
4476 template, not in the specialization. */
4477 tpd2.current_arg = i;
4478 tpd2.arg_uses_template_parms[i] = 0;
4479 memset (tpd2.parms, 0, sizeof (int) * nargs);
4480 for_each_template_parm (type,
4481 &mark_template_parm,
4484 /*include_nondeduced_p=*/false);
4486 if (tpd2.arg_uses_template_parms [i])
4488 /* The type depended on some template parameters.
4489 If they are fully specialized in the
4490 specialization, that's OK. */
4493 for (j = 0; j < nargs; ++j)
4494 if (tpd2.parms[j] != 0
4495 && tpd.arg_uses_template_parms [j])
4498 error_n (input_location, count,
4499 "type %qT of template argument %qE depends "
4500 "on a template parameter",
4501 "type %qT of template argument %qE depends "
4502 "on template parameters",
4511 /* We should only get here once. */
4512 gcc_assert (!COMPLETE_TYPE_P (type));
4514 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)
4515 = tree_cons (specargs, inner_parms,
4516 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl));
4517 TREE_TYPE (DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)) = type;
4519 for (inst = DECL_TEMPLATE_INSTANTIATIONS (maintmpl); inst;
4520 inst = TREE_CHAIN (inst))
4522 tree inst_type = TREE_VALUE (inst);
4523 if (COMPLETE_TYPE_P (inst_type)
4524 && CLASSTYPE_IMPLICIT_INSTANTIATION (inst_type))
4526 tree spec = most_specialized_class (inst_type, maintmpl, tf_none);
4527 if (spec && TREE_TYPE (spec) == type)
4528 permerror (input_location,
4529 "partial specialization of %qT after instantiation "
4530 "of %qT", type, inst_type);
4537 /* Check that a template declaration's use of default arguments and
4538 parameter packs is not invalid. Here, PARMS are the template
4539 parameters. IS_PRIMARY is nonzero if DECL is the thing declared by
4540 a primary template. IS_PARTIAL is nonzero if DECL is a partial
4544 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4545 declaration (but not a definition); 1 indicates a declaration, 2
4546 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4547 emitted for extraneous default arguments.
4549 Returns TRUE if there were no errors found, FALSE otherwise. */
4552 check_default_tmpl_args (tree decl, tree parms, int is_primary,
4553 int is_partial, int is_friend_decl)
4556 int last_level_to_check;
4558 bool no_errors = true;
4562 A default template-argument shall not be specified in a
4563 function template declaration or a function template definition, nor
4564 in the template-parameter-list of the definition of a member of a
4567 if (TREE_CODE (CP_DECL_CONTEXT (decl)) == FUNCTION_DECL)
4568 /* You can't have a function template declaration in a local
4569 scope, nor you can you define a member of a class template in a
4573 if (current_class_type
4574 && !TYPE_BEING_DEFINED (current_class_type)
4575 && DECL_LANG_SPECIFIC (decl)
4576 && DECL_DECLARES_FUNCTION_P (decl)
4577 /* If this is either a friend defined in the scope of the class
4578 or a member function. */
4579 && (DECL_FUNCTION_MEMBER_P (decl)
4580 ? same_type_p (DECL_CONTEXT (decl), current_class_type)
4581 : DECL_FRIEND_CONTEXT (decl)
4582 ? same_type_p (DECL_FRIEND_CONTEXT (decl), current_class_type)
4584 /* And, if it was a member function, it really was defined in
4585 the scope of the class. */
4586 && (!DECL_FUNCTION_MEMBER_P (decl)
4587 || DECL_INITIALIZED_IN_CLASS_P (decl)))
4588 /* We already checked these parameters when the template was
4589 declared, so there's no need to do it again now. This function
4590 was defined in class scope, but we're processing it's body now
4591 that the class is complete. */
4594 /* Core issue 226 (C++0x only): the following only applies to class
4596 if ((cxx_dialect == cxx98) || TREE_CODE (decl) != FUNCTION_DECL)
4600 If a template-parameter has a default template-argument, all
4601 subsequent template-parameters shall have a default
4602 template-argument supplied. */
4603 for (parm_level = parms; parm_level; parm_level = TREE_CHAIN (parm_level))
4605 tree inner_parms = TREE_VALUE (parm_level);
4606 int ntparms = TREE_VEC_LENGTH (inner_parms);
4607 int seen_def_arg_p = 0;
4610 for (i = 0; i < ntparms; ++i)
4612 tree parm = TREE_VEC_ELT (inner_parms, i);
4614 if (parm == error_mark_node)
4617 if (TREE_PURPOSE (parm))
4619 else if (seen_def_arg_p
4620 && !template_parameter_pack_p (TREE_VALUE (parm)))
4622 error ("no default argument for %qD", TREE_VALUE (parm));
4623 /* For better subsequent error-recovery, we indicate that
4624 there should have been a default argument. */
4625 TREE_PURPOSE (parm) = error_mark_node;
4631 /* Don't complain about an enclosing partial
4633 && parm_level == parms
4634 && TREE_CODE (decl) == TYPE_DECL
4636 && template_parameter_pack_p (TREE_VALUE (parm)))
4638 /* A primary class template can only have one
4639 parameter pack, at the end of the template
4642 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL)
4643 error ("parameter pack %qE must be at the end of the"
4644 " template parameter list", TREE_VALUE (parm));
4646 error ("parameter pack %qT must be at the end of the"
4647 " template parameter list",
4648 TREE_TYPE (TREE_VALUE (parm)));
4650 TREE_VALUE (TREE_VEC_ELT (inner_parms, i))
4658 if (((cxx_dialect == cxx98) && TREE_CODE (decl) != TYPE_DECL)
4662 /* For an ordinary class template, default template arguments are
4663 allowed at the innermost level, e.g.:
4664 template <class T = int>
4666 but, in a partial specialization, they're not allowed even
4667 there, as we have in [temp.class.spec]:
4669 The template parameter list of a specialization shall not
4670 contain default template argument values.
4672 So, for a partial specialization, or for a function template
4673 (in C++98/C++03), we look at all of them. */
4676 /* But, for a primary class template that is not a partial
4677 specialization we look at all template parameters except the
4679 parms = TREE_CHAIN (parms);
4681 /* Figure out what error message to issue. */
4682 if (is_friend_decl == 2)
4683 msg = G_("default template arguments may not be used in function template "
4684 "friend re-declaration");
4685 else if (is_friend_decl)
4686 msg = G_("default template arguments may not be used in function template "
4687 "friend declarations");
4688 else if (TREE_CODE (decl) == FUNCTION_DECL && (cxx_dialect == cxx98))
4689 msg = G_("default template arguments may not be used in function templates "
4690 "without -std=c++11 or -std=gnu++11");
4691 else if (is_partial)
4692 msg = G_("default template arguments may not be used in "
4693 "partial specializations");
4695 msg = G_("default argument for template parameter for class enclosing %qD");
4697 if (current_class_type && TYPE_BEING_DEFINED (current_class_type))
4698 /* If we're inside a class definition, there's no need to
4699 examine the parameters to the class itself. On the one
4700 hand, they will be checked when the class is defined, and,
4701 on the other, default arguments are valid in things like:
4702 template <class T = double>
4703 struct S { template <class U> void f(U); };
4704 Here the default argument for `S' has no bearing on the
4705 declaration of `f'. */
4706 last_level_to_check = template_class_depth (current_class_type) + 1;
4708 /* Check everything. */
4709 last_level_to_check = 0;
4711 for (parm_level = parms;
4712 parm_level && TMPL_PARMS_DEPTH (parm_level) >= last_level_to_check;
4713 parm_level = TREE_CHAIN (parm_level))
4715 tree inner_parms = TREE_VALUE (parm_level);
4719 ntparms = TREE_VEC_LENGTH (inner_parms);
4720 for (i = 0; i < ntparms; ++i)
4722 if (TREE_VEC_ELT (inner_parms, i) == error_mark_node)
4725 if (TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)))
4730 if (is_friend_decl == 2)
4737 /* Clear out the default argument so that we are not
4739 TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)) = NULL_TREE;
4743 /* At this point, if we're still interested in issuing messages,
4744 they must apply to classes surrounding the object declared. */
4746 msg = G_("default argument for template parameter for class "
4753 /* Worker for push_template_decl_real, called via
4754 for_each_template_parm. DATA is really an int, indicating the
4755 level of the parameters we are interested in. If T is a template
4756 parameter of that level, return nonzero. */
4759 template_parm_this_level_p (tree t, void* data)
4761 int this_level = *(int *)data;
4764 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
4765 level = TEMPLATE_PARM_LEVEL (t);
4767 level = TEMPLATE_TYPE_LEVEL (t);
4768 return level == this_level;
4771 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4772 parameters given by current_template_args, or reuses a
4773 previously existing one, if appropriate. Returns the DECL, or an
4774 equivalent one, if it is replaced via a call to duplicate_decls.
4776 If IS_FRIEND is true, DECL is a friend declaration. */
4779 push_template_decl_real (tree decl, bool is_friend)
4787 int new_template_p = 0;
4788 /* True if the template is a member template, in the sense of
4790 bool member_template_p = false;
4792 if (decl == error_mark_node || !current_template_parms)
4793 return error_mark_node;
4795 /* See if this is a partial specialization. */
4796 is_partial = (DECL_IMPLICIT_TYPEDEF_P (decl)
4797 && TREE_CODE (TREE_TYPE (decl)) != ENUMERAL_TYPE
4798 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)));
4800 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_FRIEND_P (decl))
4804 /* For a friend, we want the context of the friend function, not
4805 the type of which it is a friend. */
4806 ctx = CP_DECL_CONTEXT (decl);
4807 else if (CP_DECL_CONTEXT (decl)
4808 && TREE_CODE (CP_DECL_CONTEXT (decl)) != NAMESPACE_DECL)
4809 /* In the case of a virtual function, we want the class in which
4811 ctx = CP_DECL_CONTEXT (decl);
4813 /* Otherwise, if we're currently defining some class, the DECL
4814 is assumed to be a member of the class. */
4815 ctx = current_scope ();
4817 if (ctx && TREE_CODE (ctx) == NAMESPACE_DECL)
4820 if (!DECL_CONTEXT (decl))
4821 DECL_CONTEXT (decl) = FROB_CONTEXT (current_namespace);
4823 /* See if this is a primary template. */
4824 if (is_friend && ctx)
4825 /* A friend template that specifies a class context, i.e.
4826 template <typename T> friend void A<T>::f();
4830 primary = template_parm_scope_p ();
4834 if (DECL_CLASS_SCOPE_P (decl))
4835 member_template_p = true;
4836 if (TREE_CODE (decl) == TYPE_DECL
4837 && ANON_AGGRNAME_P (DECL_NAME (decl)))
4839 error ("template class without a name");
4840 return error_mark_node;
4842 else if (TREE_CODE (decl) == FUNCTION_DECL)
4844 if (DECL_DESTRUCTOR_P (decl))
4848 A destructor shall not be a member template. */
4849 error ("destructor %qD declared as member template", decl);
4850 return error_mark_node;
4852 if (NEW_DELETE_OPNAME_P (DECL_NAME (decl))
4853 && (!prototype_p (TREE_TYPE (decl))
4854 || TYPE_ARG_TYPES (TREE_TYPE (decl)) == void_list_node
4855 || !TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (decl)))
4856 || (TREE_CHAIN (TYPE_ARG_TYPES ((TREE_TYPE (decl))))
4857 == void_list_node)))
4859 /* [basic.stc.dynamic.allocation]
4861 An allocation function can be a function
4862 template. ... Template allocation functions shall
4863 have two or more parameters. */
4864 error ("invalid template declaration of %qD", decl);
4865 return error_mark_node;
4868 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4869 && CLASS_TYPE_P (TREE_TYPE (decl)))
4871 else if (TREE_CODE (decl) == TYPE_DECL
4872 && TYPE_DECL_ALIAS_P (decl))
4873 /* alias-declaration */
4874 gcc_assert (!DECL_ARTIFICIAL (decl));
4877 error ("template declaration of %q#D", decl);
4878 return error_mark_node;
4882 /* Check to see that the rules regarding the use of default
4883 arguments are not being violated. */
4884 check_default_tmpl_args (decl, current_template_parms,
4885 primary, is_partial, /*is_friend_decl=*/0);
4887 /* Ensure that there are no parameter packs in the type of this
4888 declaration that have not been expanded. */
4889 if (TREE_CODE (decl) == FUNCTION_DECL)
4891 /* Check each of the arguments individually to see if there are
4892 any bare parameter packs. */
4893 tree type = TREE_TYPE (decl);
4894 tree arg = DECL_ARGUMENTS (decl);
4895 tree argtype = TYPE_ARG_TYPES (type);
4897 while (arg && argtype)
4899 if (!FUNCTION_PARAMETER_PACK_P (arg)
4900 && check_for_bare_parameter_packs (TREE_TYPE (arg)))
4902 /* This is a PARM_DECL that contains unexpanded parameter
4903 packs. We have already complained about this in the
4904 check_for_bare_parameter_packs call, so just replace
4905 these types with ERROR_MARK_NODE. */
4906 TREE_TYPE (arg) = error_mark_node;
4907 TREE_VALUE (argtype) = error_mark_node;
4910 arg = DECL_CHAIN (arg);
4911 argtype = TREE_CHAIN (argtype);
4914 /* Check for bare parameter packs in the return type and the
4915 exception specifiers. */
4916 if (check_for_bare_parameter_packs (TREE_TYPE (type)))
4917 /* Errors were already issued, set return type to int
4918 as the frontend doesn't expect error_mark_node as
4920 TREE_TYPE (type) = integer_type_node;
4921 if (check_for_bare_parameter_packs (TYPE_RAISES_EXCEPTIONS (type)))
4922 TYPE_RAISES_EXCEPTIONS (type) = NULL_TREE;
4924 else if (check_for_bare_parameter_packs ((TREE_CODE (decl) == TYPE_DECL
4925 && TYPE_DECL_ALIAS_P (decl))
4926 ? DECL_ORIGINAL_TYPE (decl)
4927 : TREE_TYPE (decl)))
4929 TREE_TYPE (decl) = error_mark_node;
4930 return error_mark_node;
4934 return process_partial_specialization (decl);
4936 args = current_template_args ();
4939 || TREE_CODE (ctx) == FUNCTION_DECL
4940 || (CLASS_TYPE_P (ctx) && TYPE_BEING_DEFINED (ctx))
4941 || (is_friend && !DECL_TEMPLATE_INFO (decl)))
4943 if (DECL_LANG_SPECIFIC (decl)
4944 && DECL_TEMPLATE_INFO (decl)
4945 && DECL_TI_TEMPLATE (decl))
4946 tmpl = DECL_TI_TEMPLATE (decl);
4947 /* If DECL is a TYPE_DECL for a class-template, then there won't
4948 be DECL_LANG_SPECIFIC. The information equivalent to
4949 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4950 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4951 && TYPE_TEMPLATE_INFO (TREE_TYPE (decl))
4952 && TYPE_TI_TEMPLATE (TREE_TYPE (decl)))
4954 /* Since a template declaration already existed for this
4955 class-type, we must be redeclaring it here. Make sure
4956 that the redeclaration is valid. */
4957 redeclare_class_template (TREE_TYPE (decl),
4958 current_template_parms);
4959 /* We don't need to create a new TEMPLATE_DECL; just use the
4960 one we already had. */
4961 tmpl = TYPE_TI_TEMPLATE (TREE_TYPE (decl));
4965 tmpl = build_template_decl (decl, current_template_parms,
4969 if (DECL_LANG_SPECIFIC (decl)
4970 && DECL_TEMPLATE_SPECIALIZATION (decl))
4972 /* A specialization of a member template of a template
4974 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
4975 DECL_TEMPLATE_INFO (tmpl) = DECL_TEMPLATE_INFO (decl);
4976 DECL_TEMPLATE_INFO (decl) = NULL_TREE;
4982 tree a, t, current, parms;
4984 tree tinfo = get_template_info (decl);
4988 error ("template definition of non-template %q#D", decl);
4989 return error_mark_node;
4992 tmpl = TI_TEMPLATE (tinfo);
4994 if (DECL_FUNCTION_TEMPLATE_P (tmpl)
4995 && DECL_TEMPLATE_INFO (decl) && DECL_TI_ARGS (decl)
4996 && DECL_TEMPLATE_SPECIALIZATION (decl)
4997 && DECL_MEMBER_TEMPLATE_P (tmpl))
5001 /* The declaration is a specialization of a member
5002 template, declared outside the class. Therefore, the
5003 innermost template arguments will be NULL, so we
5004 replace them with the arguments determined by the
5005 earlier call to check_explicit_specialization. */
5006 args = DECL_TI_ARGS (decl);
5009 = build_template_decl (decl, current_template_parms,
5011 DECL_TEMPLATE_RESULT (new_tmpl) = decl;
5012 TREE_TYPE (new_tmpl) = TREE_TYPE (decl);
5013 DECL_TI_TEMPLATE (decl) = new_tmpl;
5014 SET_DECL_TEMPLATE_SPECIALIZATION (new_tmpl);
5015 DECL_TEMPLATE_INFO (new_tmpl)
5016 = build_template_info (tmpl, args);
5018 register_specialization (new_tmpl,
5019 most_general_template (tmpl),
5025 /* Make sure the template headers we got make sense. */
5027 parms = DECL_TEMPLATE_PARMS (tmpl);
5028 i = TMPL_PARMS_DEPTH (parms);
5029 if (TMPL_ARGS_DEPTH (args) != i)
5031 error ("expected %d levels of template parms for %q#D, got %d",
5032 i, decl, TMPL_ARGS_DEPTH (args));
5035 for (current = decl; i > 0; --i, parms = TREE_CHAIN (parms))
5037 a = TMPL_ARGS_LEVEL (args, i);
5038 t = INNERMOST_TEMPLATE_PARMS (parms);
5040 if (TREE_VEC_LENGTH (t) != TREE_VEC_LENGTH (a))
5042 if (current == decl)
5043 error ("got %d template parameters for %q#D",
5044 TREE_VEC_LENGTH (a), decl);
5046 error ("got %d template parameters for %q#T",
5047 TREE_VEC_LENGTH (a), current);
5048 error (" but %d required", TREE_VEC_LENGTH (t));
5049 return error_mark_node;
5052 if (current == decl)
5054 else if (current == NULL_TREE)
5055 /* Can happen in erroneous input. */
5058 current = (TYPE_P (current)
5059 ? TYPE_CONTEXT (current)
5060 : DECL_CONTEXT (current));
5063 /* Check that the parms are used in the appropriate qualifying scopes
5064 in the declarator. */
5065 if (!comp_template_args
5067 TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (tmpl)))))
5070 template arguments to %qD do not match original template %qD",
5071 decl, DECL_TEMPLATE_RESULT (tmpl));
5072 if (!uses_template_parms (TI_ARGS (tinfo)))
5073 inform (input_location, "use template<> for an explicit specialization");
5074 /* Avoid crash in import_export_decl. */
5075 DECL_INTERFACE_KNOWN (decl) = 1;
5076 return error_mark_node;
5080 DECL_TEMPLATE_RESULT (tmpl) = decl;
5081 TREE_TYPE (tmpl) = TREE_TYPE (decl);
5083 /* Push template declarations for global functions and types. Note
5084 that we do not try to push a global template friend declared in a
5085 template class; such a thing may well depend on the template
5086 parameters of the class. */
5087 if (new_template_p && !ctx
5088 && !(is_friend && template_class_depth (current_class_type) > 0))
5090 tmpl = pushdecl_namespace_level (tmpl, is_friend);
5091 if (tmpl == error_mark_node)
5092 return error_mark_node;
5094 /* Hide template friend classes that haven't been declared yet. */
5095 if (is_friend && TREE_CODE (decl) == TYPE_DECL)
5097 DECL_ANTICIPATED (tmpl) = 1;
5098 DECL_FRIEND_P (tmpl) = 1;
5104 tree parms = DECL_TEMPLATE_PARMS (tmpl);
5107 DECL_PRIMARY_TEMPLATE (tmpl) = tmpl;
5108 if (DECL_CONV_FN_P (tmpl))
5110 int depth = TMPL_PARMS_DEPTH (parms);
5112 /* It is a conversion operator. See if the type converted to
5113 depends on innermost template operands. */
5115 if (uses_template_parms_level (TREE_TYPE (TREE_TYPE (tmpl)),
5117 DECL_TEMPLATE_CONV_FN_P (tmpl) = 1;
5120 /* Give template template parms a DECL_CONTEXT of the template
5121 for which they are a parameter. */
5122 parms = INNERMOST_TEMPLATE_PARMS (parms);
5123 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
5125 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
5126 if (TREE_CODE (parm) == TEMPLATE_DECL)
5127 DECL_CONTEXT (parm) = tmpl;
5131 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5132 back to its most general template. If TMPL is a specialization,
5133 ARGS may only have the innermost set of arguments. Add the missing
5134 argument levels if necessary. */
5135 if (DECL_TEMPLATE_INFO (tmpl))
5136 args = add_outermost_template_args (DECL_TI_ARGS (tmpl), args);
5138 info = build_template_info (tmpl, args);
5140 if (DECL_IMPLICIT_TYPEDEF_P (decl))
5141 SET_TYPE_TEMPLATE_INFO (TREE_TYPE (tmpl), info);
5144 if (primary && !DECL_LANG_SPECIFIC (decl))
5145 retrofit_lang_decl (decl);
5146 if (DECL_LANG_SPECIFIC (decl))
5147 DECL_TEMPLATE_INFO (decl) = info;
5150 return DECL_TEMPLATE_RESULT (tmpl);
5154 push_template_decl (tree decl)
5156 return push_template_decl_real (decl, false);
5159 /* Called when a class template TYPE is redeclared with the indicated
5160 template PARMS, e.g.:
5162 template <class T> struct S;
5163 template <class T> struct S {}; */
5166 redeclare_class_template (tree type, tree parms)
5172 if (!TYPE_TEMPLATE_INFO (type))
5174 error ("%qT is not a template type", type);
5178 tmpl = TYPE_TI_TEMPLATE (type);
5179 if (!PRIMARY_TEMPLATE_P (tmpl))
5180 /* The type is nested in some template class. Nothing to worry
5181 about here; there are no new template parameters for the nested
5187 error ("template specifiers not specified in declaration of %qD",
5192 parms = INNERMOST_TEMPLATE_PARMS (parms);
5193 tmpl_parms = DECL_INNERMOST_TEMPLATE_PARMS (tmpl);
5195 if (TREE_VEC_LENGTH (parms) != TREE_VEC_LENGTH (tmpl_parms))
5197 error_n (input_location, TREE_VEC_LENGTH (parms),
5198 "redeclared with %d template parameter",
5199 "redeclared with %d template parameters",
5200 TREE_VEC_LENGTH (parms));
5201 inform_n (input_location, TREE_VEC_LENGTH (tmpl_parms),
5202 "previous declaration %q+D used %d template parameter",
5203 "previous declaration %q+D used %d template parameters",
5204 tmpl, TREE_VEC_LENGTH (tmpl_parms));
5208 for (i = 0; i < TREE_VEC_LENGTH (tmpl_parms); ++i)
5215 if (TREE_VEC_ELT (tmpl_parms, i) == error_mark_node
5216 || TREE_VEC_ELT (parms, i) == error_mark_node)
5219 tmpl_parm = TREE_VALUE (TREE_VEC_ELT (tmpl_parms, i));
5220 if (tmpl_parm == error_mark_node)
5223 parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
5224 tmpl_default = TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i));
5225 parm_default = TREE_PURPOSE (TREE_VEC_ELT (parms, i));
5227 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5229 if (TREE_CODE (tmpl_parm) != TREE_CODE (parm)
5230 || (TREE_CODE (tmpl_parm) != TYPE_DECL
5231 && !same_type_p (TREE_TYPE (tmpl_parm), TREE_TYPE (parm)))
5232 || (TREE_CODE (tmpl_parm) != PARM_DECL
5233 && (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (tmpl_parm))
5234 != TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm))))
5235 || (TREE_CODE (tmpl_parm) == PARM_DECL
5236 && (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (tmpl_parm))
5237 != TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))))
5239 error ("template parameter %q+#D", tmpl_parm);
5240 error ("redeclared here as %q#D", parm);
5244 if (tmpl_default != NULL_TREE && parm_default != NULL_TREE)
5246 /* We have in [temp.param]:
5248 A template-parameter may not be given default arguments
5249 by two different declarations in the same scope. */
5250 error_at (input_location, "redefinition of default argument for %q#D", parm);
5251 inform (DECL_SOURCE_LOCATION (tmpl_parm),
5252 "original definition appeared here");
5256 if (parm_default != NULL_TREE)
5257 /* Update the previous template parameters (which are the ones
5258 that will really count) with the new default value. */
5259 TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i)) = parm_default;
5260 else if (tmpl_default != NULL_TREE)
5261 /* Update the new parameters, too; they'll be used as the
5262 parameters for any members. */
5263 TREE_PURPOSE (TREE_VEC_ELT (parms, i)) = tmpl_default;
5269 /* Simplify EXPR if it is a non-dependent expression. Returns the
5270 (possibly simplified) expression. */
5273 fold_non_dependent_expr_sfinae (tree expr, tsubst_flags_t complain)
5275 if (expr == NULL_TREE)
5278 /* If we're in a template, but EXPR isn't value dependent, simplify
5279 it. We're supposed to treat:
5281 template <typename T> void f(T[1 + 1]);
5282 template <typename T> void f(T[2]);
5284 as two declarations of the same function, for example. */
5285 if (processing_template_decl
5286 && !type_dependent_expression_p (expr)
5287 && potential_constant_expression (expr)
5288 && !value_dependent_expression_p (expr))
5290 HOST_WIDE_INT saved_processing_template_decl;
5292 saved_processing_template_decl = processing_template_decl;
5293 processing_template_decl = 0;
5294 expr = tsubst_copy_and_build (expr,
5297 /*in_decl=*/NULL_TREE,
5298 /*function_p=*/false,
5299 /*integral_constant_expression_p=*/true);
5300 processing_template_decl = saved_processing_template_decl;
5306 fold_non_dependent_expr (tree expr)
5308 return fold_non_dependent_expr_sfinae (expr, tf_error);
5311 /* Return TRUE iff T is a type alias, a TEMPLATE_DECL for an alias
5312 template declaration, or a TYPE_DECL for an alias declaration. */
5315 alias_type_or_template_p (tree t)
5319 return ((TREE_CODE (t) == TYPE_DECL && TYPE_DECL_ALIAS_P (t))
5322 && TYPE_DECL_ALIAS_P (TYPE_NAME (t)))
5323 || DECL_ALIAS_TEMPLATE_P (t));
5326 /* Return TRUE iff is a specialization of an alias template. */
5329 alias_template_specialization_p (tree t)
5333 return (primary_template_instantiation_p (t)
5334 && DECL_ALIAS_TEMPLATE_P (TYPE_TI_TEMPLATE (t)));
5337 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5338 must be a function or a pointer-to-function type, as specified
5339 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5340 and check that the resulting function has external linkage. */
5343 convert_nontype_argument_function (tree type, tree expr)
5347 linkage_kind linkage;
5349 fn = instantiate_type (type, fns, tf_none);
5350 if (fn == error_mark_node)
5351 return error_mark_node;
5354 if (TREE_CODE (fn_no_ptr) == ADDR_EXPR)
5355 fn_no_ptr = TREE_OPERAND (fn_no_ptr, 0);
5356 if (BASELINK_P (fn_no_ptr))
5357 fn_no_ptr = BASELINK_FUNCTIONS (fn_no_ptr);
5359 /* [temp.arg.nontype]/1
5361 A template-argument for a non-type, non-template template-parameter
5364 -- the address of an object or function with external [C++11: or
5365 internal] linkage. */
5366 linkage = decl_linkage (fn_no_ptr);
5367 if (cxx_dialect >= cxx0x ? linkage == lk_none : linkage != lk_external)
5369 if (cxx_dialect >= cxx0x)
5370 error ("%qE is not a valid template argument for type %qT "
5371 "because %qD has no linkage",
5372 expr, type, fn_no_ptr);
5374 error ("%qE is not a valid template argument for type %qT "
5375 "because %qD does not have external linkage",
5376 expr, type, fn_no_ptr);
5383 /* Subroutine of convert_nontype_argument.
5384 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5385 Emit an error otherwise. */
5388 check_valid_ptrmem_cst_expr (tree type, tree expr,
5389 tsubst_flags_t complain)
5392 if (expr && (null_ptr_cst_p (expr) || TREE_CODE (expr) == PTRMEM_CST))
5394 if (cxx_dialect >= cxx0x && null_member_pointer_value_p (expr))
5396 if (complain & tf_error)
5398 error ("%qE is not a valid template argument for type %qT",
5400 error ("it must be a pointer-to-member of the form %<&X::Y%>");
5405 /* Returns TRUE iff the address of OP is value-dependent.
5407 14.6.2.4 [temp.dep.temp]:
5408 A non-integral non-type template-argument is dependent if its type is
5409 dependent or it has either of the following forms
5412 and contains a nested-name-specifier which specifies a class-name that
5413 names a dependent type.
5415 We generalize this to just say that the address of a member of a
5416 dependent class is value-dependent; the above doesn't cover the
5417 address of a static data member named with an unqualified-id. */
5420 has_value_dependent_address (tree op)
5422 /* We could use get_inner_reference here, but there's no need;
5423 this is only relevant for template non-type arguments, which
5424 can only be expressed as &id-expression. */
5427 tree ctx = CP_DECL_CONTEXT (op);
5428 if (TYPE_P (ctx) && dependent_type_p (ctx))
5435 /* The next set of functions are used for providing helpful explanatory
5436 diagnostics for failed overload resolution. Their messages should be
5437 indented by two spaces for consistency with the messages in
5441 unify_success (bool explain_p ATTRIBUTE_UNUSED)
5447 unify_parameter_deduction_failure (bool explain_p, tree parm)
5450 inform (input_location,
5451 " couldn't deduce template parameter %qD", parm);
5456 unify_invalid (bool explain_p ATTRIBUTE_UNUSED)
5462 unify_cv_qual_mismatch (bool explain_p, tree parm, tree arg)
5465 inform (input_location,
5466 " types %qT and %qT have incompatible cv-qualifiers",
5472 unify_type_mismatch (bool explain_p, tree parm, tree arg)
5475 inform (input_location, " mismatched types %qT and %qT", parm, arg);
5480 unify_parameter_pack_mismatch (bool explain_p, tree parm, tree arg)
5483 inform (input_location,
5484 " template parameter %qD is not a parameter pack, but "
5491 unify_ptrmem_cst_mismatch (bool explain_p, tree parm, tree arg)
5494 inform (input_location,
5495 " template argument %qE does not match "
5496 "pointer-to-member constant %qE",
5502 unify_expression_unequal (bool explain_p, tree parm, tree arg)
5505 inform (input_location, " %qE is not equivalent to %qE", parm, arg);
5510 unify_parameter_pack_inconsistent (bool explain_p, tree old_arg, tree new_arg)
5513 inform (input_location,
5514 " inconsistent parameter pack deduction with %qT and %qT",
5520 unify_inconsistency (bool explain_p, tree parm, tree first, tree second)
5525 inform (input_location,
5526 " deduced conflicting types for parameter %qT (%qT and %qT)",
5527 parm, first, second);
5529 inform (input_location,
5530 " deduced conflicting values for non-type parameter "
5531 "%qE (%qE and %qE)", parm, first, second);
5537 unify_vla_arg (bool explain_p, tree arg)
5540 inform (input_location,
5541 " variable-sized array type %qT is not "
5542 "a valid template argument",
5548 unify_method_type_error (bool explain_p, tree arg)
5551 inform (input_location,
5552 " member function type %qT is not a valid template argument",
5558 unify_arity (bool explain_p, int have, int wanted)
5561 inform_n (input_location, wanted,
5562 " candidate expects %d argument, %d provided",
5563 " candidate expects %d arguments, %d provided",
5569 unify_too_many_arguments (bool explain_p, int have, int wanted)
5571 return unify_arity (explain_p, have, wanted);
5575 unify_too_few_arguments (bool explain_p, int have, int wanted)
5577 return unify_arity (explain_p, have, wanted);
5581 unify_arg_conversion (bool explain_p, tree to_type,
5582 tree from_type, tree arg)
5585 inform (input_location, " cannot convert %qE (type %qT) to type %qT",
5586 arg, from_type, to_type);
5591 unify_no_common_base (bool explain_p, enum template_base_result r,
5592 tree parm, tree arg)
5597 case tbr_ambiguous_baseclass:
5598 inform (input_location, " %qT is an ambiguous base class of %qT",
5602 inform (input_location, " %qT is not derived from %qT", arg, parm);
5609 unify_inconsistent_template_template_parameters (bool explain_p)
5612 inform (input_location,
5613 " template parameters of a template template argument are "
5614 "inconsistent with other deduced template arguments");
5619 unify_template_deduction_failure (bool explain_p, tree parm, tree arg)
5622 inform (input_location,
5623 " can't deduce a template for %qT from non-template type %qT",
5629 unify_template_argument_mismatch (bool explain_p, tree parm, tree arg)
5632 inform (input_location,
5633 " template argument %qE does not match %qD", arg, parm);
5638 unify_overload_resolution_failure (bool explain_p, tree arg)
5641 inform (input_location,
5642 " could not resolve address from overloaded function %qE",
5647 /* Attempt to convert the non-type template parameter EXPR to the
5648 indicated TYPE. If the conversion is successful, return the
5649 converted value. If the conversion is unsuccessful, return
5650 NULL_TREE if we issued an error message, or error_mark_node if we
5651 did not. We issue error messages for out-and-out bad template
5652 parameters, but not simply because the conversion failed, since we
5653 might be just trying to do argument deduction. Both TYPE and EXPR
5654 must be non-dependent.
5656 The conversion follows the special rules described in
5657 [temp.arg.nontype], and it is much more strict than an implicit
5660 This function is called twice for each template argument (see
5661 lookup_template_class for a more accurate description of this
5662 problem). This means that we need to handle expressions which
5663 are not valid in a C++ source, but can be created from the
5664 first call (for instance, casts to perform conversions). These
5665 hacks can go away after we fix the double coercion problem. */
5668 convert_nontype_argument (tree type, tree expr, tsubst_flags_t complain)
5672 /* Detect immediately string literals as invalid non-type argument.
5673 This special-case is not needed for correctness (we would easily
5674 catch this later), but only to provide better diagnostic for this
5675 common user mistake. As suggested by DR 100, we do not mention
5676 linkage issues in the diagnostic as this is not the point. */
5677 /* FIXME we're making this OK. */
5678 if (TREE_CODE (expr) == STRING_CST)
5680 if (complain & tf_error)
5681 error ("%qE is not a valid template argument for type %qT "
5682 "because string literals can never be used in this context",
5687 /* Add the ADDR_EXPR now for the benefit of
5688 value_dependent_expression_p. */
5689 if (TYPE_PTROBV_P (type)
5690 && TREE_CODE (TREE_TYPE (expr)) == ARRAY_TYPE)
5691 expr = decay_conversion (expr);
5693 /* If we are in a template, EXPR may be non-dependent, but still
5694 have a syntactic, rather than semantic, form. For example, EXPR
5695 might be a SCOPE_REF, rather than the VAR_DECL to which the
5696 SCOPE_REF refers. Preserving the qualifying scope is necessary
5697 so that access checking can be performed when the template is
5698 instantiated -- but here we need the resolved form so that we can
5699 convert the argument. */
5700 if (TYPE_REF_OBJ_P (type)
5701 && has_value_dependent_address (expr))
5702 /* If we want the address and it's value-dependent, don't fold. */;
5703 else if (!type_unknown_p (expr))
5704 expr = fold_non_dependent_expr_sfinae (expr, complain);
5705 if (error_operand_p (expr))
5706 return error_mark_node;
5707 expr_type = TREE_TYPE (expr);
5708 if (TREE_CODE (type) == REFERENCE_TYPE)
5709 expr = mark_lvalue_use (expr);
5711 expr = mark_rvalue_use (expr);
5713 /* 14.3.2/5: The null pointer{,-to-member} conversion is applied
5714 to a non-type argument of "nullptr". */
5715 if (expr == nullptr_node
5716 && (TYPE_PTR_P (type) || TYPE_PTR_TO_MEMBER_P (type)))
5717 expr = convert (type, expr);
5719 /* In C++11, integral or enumeration non-type template arguments can be
5720 arbitrary constant expressions. Pointer and pointer to
5721 member arguments can be general constant expressions that evaluate
5722 to a null value, but otherwise still need to be of a specific form. */
5723 if (cxx_dialect >= cxx0x)
5725 if (TREE_CODE (expr) == PTRMEM_CST)
5726 /* A PTRMEM_CST is already constant, and a valid template
5727 argument for a parameter of pointer to member type, we just want
5728 to leave it in that form rather than lower it to a
5730 else if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
5731 expr = maybe_constant_value (expr);
5732 else if (TYPE_PTR_P (type)
5733 || TYPE_PTR_TO_MEMBER_P (type))
5735 tree folded = maybe_constant_value (expr);
5736 if (TYPE_PTR_P (type) ? integer_zerop (folded)
5737 : null_member_pointer_value_p (folded))
5742 /* HACK: Due to double coercion, we can get a
5743 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5744 which is the tree that we built on the first call (see
5745 below when coercing to reference to object or to reference to
5746 function). We just strip everything and get to the arg.
5747 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5749 if (TYPE_REF_OBJ_P (type) || TYPE_REFFN_P (type))
5751 tree probe_type, probe = expr;
5752 if (REFERENCE_REF_P (probe))
5753 probe = TREE_OPERAND (probe, 0);
5754 probe_type = TREE_TYPE (probe);
5755 if (TREE_CODE (probe) == NOP_EXPR)
5757 /* ??? Maybe we could use convert_from_reference here, but we
5758 would need to relax its constraints because the NOP_EXPR
5759 could actually change the type to something more cv-qualified,
5760 and this is not folded by convert_from_reference. */
5761 tree addr = TREE_OPERAND (probe, 0);
5762 gcc_assert (TREE_CODE (probe_type) == REFERENCE_TYPE);
5763 gcc_assert (TREE_CODE (addr) == ADDR_EXPR);
5764 gcc_assert (TREE_CODE (TREE_TYPE (addr)) == POINTER_TYPE);
5765 gcc_assert (same_type_ignoring_top_level_qualifiers_p
5766 (TREE_TYPE (probe_type),
5767 TREE_TYPE (TREE_TYPE (addr))));
5769 expr = TREE_OPERAND (addr, 0);
5770 expr_type = TREE_TYPE (expr);
5774 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5775 parameter is a pointer to object, through decay and
5776 qualification conversion. Let's strip everything. */
5777 else if (TREE_CODE (expr) == NOP_EXPR && TYPE_PTROBV_P (type))
5780 gcc_assert (TREE_CODE (expr) == ADDR_EXPR);
5781 gcc_assert (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE);
5782 /* Skip the ADDR_EXPR only if it is part of the decay for
5783 an array. Otherwise, it is part of the original argument
5784 in the source code. */
5785 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == ARRAY_TYPE)
5786 expr = TREE_OPERAND (expr, 0);
5787 expr_type = TREE_TYPE (expr);
5790 /* [temp.arg.nontype]/5, bullet 1
5792 For a non-type template-parameter of integral or enumeration type,
5793 integral promotions (_conv.prom_) and integral conversions
5794 (_conv.integral_) are applied. */
5795 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
5797 tree t = build_integral_nontype_arg_conv (type, expr, complain);
5798 t = maybe_constant_value (t);
5799 if (t != error_mark_node)
5802 if (!same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (expr)))
5803 return error_mark_node;
5805 /* Notice that there are constant expressions like '4 % 0' which
5806 do not fold into integer constants. */
5807 if (TREE_CODE (expr) != INTEGER_CST)
5809 if (complain & tf_error)
5811 int errs = errorcount, warns = warningcount;
5812 if (processing_template_decl
5813 && !require_potential_constant_expression (expr))
5815 expr = cxx_constant_value (expr);
5816 if (errorcount > errs || warningcount > warns)
5817 inform (EXPR_LOC_OR_HERE (expr),
5818 "in template argument for type %qT ", type);
5819 if (expr == error_mark_node)
5821 /* else cxx_constant_value complained but gave us
5822 a real constant, so go ahead. */
5823 gcc_assert (TREE_CODE (expr) == INTEGER_CST);
5829 /* [temp.arg.nontype]/5, bullet 2
5831 For a non-type template-parameter of type pointer to object,
5832 qualification conversions (_conv.qual_) and the array-to-pointer
5833 conversion (_conv.array_) are applied. */
5834 else if (TYPE_PTROBV_P (type))
5836 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5838 A template-argument for a non-type, non-template template-parameter
5839 shall be one of: [...]
5841 -- the name of a non-type template-parameter;
5842 -- the address of an object or function with external linkage, [...]
5843 expressed as "& id-expression" where the & is optional if the name
5844 refers to a function or array, or if the corresponding
5845 template-parameter is a reference.
5847 Here, we do not care about functions, as they are invalid anyway
5848 for a parameter of type pointer-to-object. */
5850 if (DECL_P (expr) && DECL_TEMPLATE_PARM_P (expr))
5851 /* Non-type template parameters are OK. */
5853 else if (cxx_dialect >= cxx0x && integer_zerop (expr))
5854 /* Null pointer values are OK in C++11. */;
5855 else if (TREE_CODE (expr) != ADDR_EXPR
5856 && TREE_CODE (expr_type) != ARRAY_TYPE)
5858 if (TREE_CODE (expr) == VAR_DECL)
5860 error ("%qD is not a valid template argument "
5861 "because %qD is a variable, not the address of "
5866 /* Other values, like integer constants, might be valid
5867 non-type arguments of some other type. */
5868 return error_mark_node;
5874 decl = ((TREE_CODE (expr) == ADDR_EXPR)
5875 ? TREE_OPERAND (expr, 0) : expr);
5876 if (TREE_CODE (decl) != VAR_DECL)
5878 error ("%qE is not a valid template argument of type %qT "
5879 "because %qE is not a variable",
5883 else if (cxx_dialect < cxx0x && !DECL_EXTERNAL_LINKAGE_P (decl))
5885 error ("%qE is not a valid template argument of type %qT "
5886 "because %qD does not have external linkage",
5890 else if (cxx_dialect >= cxx0x && decl_linkage (decl) == lk_none)
5892 error ("%qE is not a valid template argument of type %qT "
5893 "because %qD has no linkage",
5899 expr = decay_conversion (expr);
5900 if (expr == error_mark_node)
5901 return error_mark_node;
5903 expr = perform_qualification_conversions (type, expr);
5904 if (expr == error_mark_node)
5905 return error_mark_node;
5907 /* [temp.arg.nontype]/5, bullet 3
5909 For a non-type template-parameter of type reference to object, no
5910 conversions apply. The type referred to by the reference may be more
5911 cv-qualified than the (otherwise identical) type of the
5912 template-argument. The template-parameter is bound directly to the
5913 template-argument, which must be an lvalue. */
5914 else if (TYPE_REF_OBJ_P (type))
5916 if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type),
5918 return error_mark_node;
5920 if (!at_least_as_qualified_p (TREE_TYPE (type), expr_type))
5922 error ("%qE is not a valid template argument for type %qT "
5923 "because of conflicts in cv-qualification", expr, type);
5927 if (!real_lvalue_p (expr))
5929 error ("%qE is not a valid template argument for type %qT "
5930 "because it is not an lvalue", expr, type);
5934 /* [temp.arg.nontype]/1
5936 A template-argument for a non-type, non-template template-parameter
5937 shall be one of: [...]
5939 -- the address of an object or function with external linkage. */
5940 if (TREE_CODE (expr) == INDIRECT_REF
5941 && TYPE_REF_OBJ_P (TREE_TYPE (TREE_OPERAND (expr, 0))))
5943 expr = TREE_OPERAND (expr, 0);
5946 error ("%q#D is not a valid template argument for type %qT "
5947 "because a reference variable does not have a constant "
5948 "address", expr, type);
5955 error ("%qE is not a valid template argument for type %qT "
5956 "because it is not an object with external linkage",
5961 if (!DECL_EXTERNAL_LINKAGE_P (expr))
5963 error ("%qE is not a valid template argument for type %qT "
5964 "because object %qD has not external linkage",
5969 expr = build_nop (type, build_address (expr));
5971 /* [temp.arg.nontype]/5, bullet 4
5973 For a non-type template-parameter of type pointer to function, only
5974 the function-to-pointer conversion (_conv.func_) is applied. If the
5975 template-argument represents a set of overloaded functions (or a
5976 pointer to such), the matching function is selected from the set
5978 else if (TYPE_PTRFN_P (type))
5980 /* If the argument is a template-id, we might not have enough
5981 context information to decay the pointer. */
5982 if (!type_unknown_p (expr_type))
5984 expr = decay_conversion (expr);
5985 if (expr == error_mark_node)
5986 return error_mark_node;
5989 if (cxx_dialect >= cxx0x && integer_zerop (expr))
5990 /* Null pointer values are OK in C++11. */
5991 return perform_qualification_conversions (type, expr);
5993 expr = convert_nontype_argument_function (type, expr);
5994 if (!expr || expr == error_mark_node)
5997 if (TREE_CODE (expr) != ADDR_EXPR)
5999 error ("%qE is not a valid template argument for type %qT", expr, type);
6000 error ("it must be the address of a function with external linkage");
6004 /* [temp.arg.nontype]/5, bullet 5
6006 For a non-type template-parameter of type reference to function, no
6007 conversions apply. If the template-argument represents a set of
6008 overloaded functions, the matching function is selected from the set
6010 else if (TYPE_REFFN_P (type))
6012 if (TREE_CODE (expr) == ADDR_EXPR)
6014 error ("%qE is not a valid template argument for type %qT "
6015 "because it is a pointer", expr, type);
6016 inform (input_location, "try using %qE instead", TREE_OPERAND (expr, 0));
6020 expr = convert_nontype_argument_function (TREE_TYPE (type), expr);
6021 if (!expr || expr == error_mark_node)
6024 expr = build_nop (type, build_address (expr));
6026 /* [temp.arg.nontype]/5, bullet 6
6028 For a non-type template-parameter of type pointer to member function,
6029 no conversions apply. If the template-argument represents a set of
6030 overloaded member functions, the matching member function is selected
6031 from the set (_over.over_). */
6032 else if (TYPE_PTRMEMFUNC_P (type))
6034 expr = instantiate_type (type, expr, tf_none);
6035 if (expr == error_mark_node)
6036 return error_mark_node;
6038 /* [temp.arg.nontype] bullet 1 says the pointer to member
6039 expression must be a pointer-to-member constant. */
6040 if (!check_valid_ptrmem_cst_expr (type, expr, complain))
6041 return error_mark_node;
6043 /* There is no way to disable standard conversions in
6044 resolve_address_of_overloaded_function (called by
6045 instantiate_type). It is possible that the call succeeded by
6046 converting &B::I to &D::I (where B is a base of D), so we need
6047 to reject this conversion here.
6049 Actually, even if there was a way to disable standard conversions,
6050 it would still be better to reject them here so that we can
6051 provide a superior diagnostic. */
6052 if (!same_type_p (TREE_TYPE (expr), type))
6054 error ("%qE is not a valid template argument for type %qT "
6055 "because it is of type %qT", expr, type,
6057 /* If we are just one standard conversion off, explain. */
6058 if (can_convert (type, TREE_TYPE (expr)))
6059 inform (input_location,
6060 "standard conversions are not allowed in this context");
6064 /* [temp.arg.nontype]/5, bullet 7
6066 For a non-type template-parameter of type pointer to data member,
6067 qualification conversions (_conv.qual_) are applied. */
6068 else if (TYPE_PTRMEM_P (type))
6070 /* [temp.arg.nontype] bullet 1 says the pointer to member
6071 expression must be a pointer-to-member constant. */
6072 if (!check_valid_ptrmem_cst_expr (type, expr, complain))
6073 return error_mark_node;
6075 expr = perform_qualification_conversions (type, expr);
6076 if (expr == error_mark_node)
6079 else if (NULLPTR_TYPE_P (type))
6081 if (expr != nullptr_node)
6083 error ("%qE is not a valid template argument for type %qT "
6084 "because it is of type %qT", expr, type, TREE_TYPE (expr));
6089 /* A template non-type parameter must be one of the above. */
6093 /* Sanity check: did we actually convert the argument to the
6095 gcc_assert (same_type_ignoring_top_level_qualifiers_p
6096 (type, TREE_TYPE (expr)));
6100 /* Subroutine of coerce_template_template_parms, which returns 1 if
6101 PARM_PARM and ARG_PARM match using the rule for the template
6102 parameters of template template parameters. Both PARM and ARG are
6103 template parameters; the rest of the arguments are the same as for
6104 coerce_template_template_parms.
6107 coerce_template_template_parm (tree parm,
6109 tsubst_flags_t complain,
6113 if (arg == NULL_TREE || arg == error_mark_node
6114 || parm == NULL_TREE || parm == error_mark_node)
6117 if (TREE_CODE (arg) != TREE_CODE (parm))
6120 switch (TREE_CODE (parm))
6123 /* We encounter instantiations of templates like
6124 template <template <template <class> class> class TT>
6127 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
6128 tree argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
6130 if (!coerce_template_template_parms
6131 (parmparm, argparm, complain, in_decl, outer_args))
6137 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (arg))
6138 && !TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
6139 /* Argument is a parameter pack but parameter is not. */
6144 /* The tsubst call is used to handle cases such as
6146 template <int> class C {};
6147 template <class T, template <T> class TT> class D {};
6150 i.e. the parameter list of TT depends on earlier parameters. */
6151 if (!uses_template_parms (TREE_TYPE (arg))
6153 (tsubst (TREE_TYPE (parm), outer_args, complain, in_decl),
6157 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (arg))
6158 && !TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
6159 /* Argument is a parameter pack but parameter is not. */
6172 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
6173 template template parameters. Both PARM_PARMS and ARG_PARMS are
6174 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
6177 Consider the example:
6178 template <class T> class A;
6179 template<template <class U> class TT> class B;
6181 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
6182 the parameters to A, and OUTER_ARGS contains A. */
6185 coerce_template_template_parms (tree parm_parms,
6187 tsubst_flags_t complain,
6191 int nparms, nargs, i;
6195 gcc_assert (TREE_CODE (parm_parms) == TREE_VEC);
6196 gcc_assert (TREE_CODE (arg_parms) == TREE_VEC);
6198 nparms = TREE_VEC_LENGTH (parm_parms);
6199 nargs = TREE_VEC_LENGTH (arg_parms);
6201 /* Determine whether we have a parameter pack at the end of the
6202 template template parameter's template parameter list. */
6203 if (TREE_VEC_ELT (parm_parms, nparms - 1) != error_mark_node)
6205 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, nparms - 1));
6207 if (parm == error_mark_node)
6210 switch (TREE_CODE (parm))
6214 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
6219 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
6229 && !(variadic_p && nargs >= nparms - 1))
6232 /* Check all of the template parameters except the parameter pack at
6233 the end (if any). */
6234 for (i = 0; i < nparms - variadic_p; ++i)
6236 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node
6237 || TREE_VEC_ELT (arg_parms, i) == error_mark_node)
6240 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
6241 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
6243 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
6251 /* Check each of the template parameters in the template
6252 argument against the template parameter pack at the end of
6253 the template template parameter. */
6254 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node)
6257 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
6259 for (; i < nargs; ++i)
6261 if (TREE_VEC_ELT (arg_parms, i) == error_mark_node)
6264 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
6266 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
6275 /* Verifies that the deduced template arguments (in TARGS) for the
6276 template template parameters (in TPARMS) represent valid bindings,
6277 by comparing the template parameter list of each template argument
6278 to the template parameter list of its corresponding template
6279 template parameter, in accordance with DR150. This
6280 routine can only be called after all template arguments have been
6281 deduced. It will return TRUE if all of the template template
6282 parameter bindings are okay, FALSE otherwise. */
6284 template_template_parm_bindings_ok_p (tree tparms, tree targs)
6286 int i, ntparms = TREE_VEC_LENGTH (tparms);
6289 /* We're dealing with template parms in this process. */
6290 ++processing_template_decl;
6292 targs = INNERMOST_TEMPLATE_ARGS (targs);
6294 for (i = 0; i < ntparms; ++i)
6296 tree tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
6297 tree targ = TREE_VEC_ELT (targs, i);
6299 if (TREE_CODE (tparm) == TEMPLATE_DECL && targ)
6301 tree packed_args = NULL_TREE;
6304 if (ARGUMENT_PACK_P (targ))
6306 /* Look inside the argument pack. */
6307 packed_args = ARGUMENT_PACK_ARGS (targ);
6308 len = TREE_VEC_LENGTH (packed_args);
6311 for (idx = 0; idx < len; ++idx)
6313 tree targ_parms = NULL_TREE;
6316 /* Extract the next argument from the argument
6318 targ = TREE_VEC_ELT (packed_args, idx);
6320 if (PACK_EXPANSION_P (targ))
6321 /* Look at the pattern of the pack expansion. */
6322 targ = PACK_EXPANSION_PATTERN (targ);
6324 /* Extract the template parameters from the template
6326 if (TREE_CODE (targ) == TEMPLATE_DECL)
6327 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (targ);
6328 else if (TREE_CODE (targ) == TEMPLATE_TEMPLATE_PARM)
6329 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (TYPE_NAME (targ));
6331 /* Verify that we can coerce the template template
6332 parameters from the template argument to the template
6333 parameter. This requires an exact match. */
6335 && !coerce_template_template_parms
6336 (DECL_INNERMOST_TEMPLATE_PARMS (tparm),
6351 --processing_template_decl;
6355 /* Since type attributes aren't mangled, we need to strip them from
6356 template type arguments. */
6359 canonicalize_type_argument (tree arg, tsubst_flags_t complain)
6362 if (!arg || arg == error_mark_node || arg == TYPE_CANONICAL (arg))
6364 mv = TYPE_MAIN_VARIANT (arg);
6365 arg = strip_typedefs (arg);
6366 if (TYPE_ALIGN (arg) != TYPE_ALIGN (mv)
6367 || TYPE_ATTRIBUTES (arg) != TYPE_ATTRIBUTES (mv))
6369 if (complain & tf_warning)
6370 warning (0, "ignoring attributes on template argument %qT", arg);
6371 arg = build_aligned_type (arg, TYPE_ALIGN (mv));
6372 arg = cp_build_type_attribute_variant (arg, TYPE_ATTRIBUTES (mv));
6377 /* Convert the indicated template ARG as necessary to match the
6378 indicated template PARM. Returns the converted ARG, or
6379 error_mark_node if the conversion was unsuccessful. Error and
6380 warning messages are issued under control of COMPLAIN. This
6381 conversion is for the Ith parameter in the parameter list. ARGS is
6382 the full set of template arguments deduced so far. */
6385 convert_template_argument (tree parm,
6388 tsubst_flags_t complain,
6394 int is_type, requires_type, is_tmpl_type, requires_tmpl_type;
6396 if (TREE_CODE (arg) == TREE_LIST
6397 && TREE_CODE (TREE_VALUE (arg)) == OFFSET_REF)
6399 /* The template argument was the name of some
6400 member function. That's usually
6401 invalid, but static members are OK. In any
6402 case, grab the underlying fields/functions
6403 and issue an error later if required. */
6404 orig_arg = TREE_VALUE (arg);
6405 TREE_TYPE (arg) = unknown_type_node;
6410 requires_tmpl_type = TREE_CODE (parm) == TEMPLATE_DECL;
6411 requires_type = (TREE_CODE (parm) == TYPE_DECL
6412 || requires_tmpl_type);
6414 /* When determining whether an argument pack expansion is a template,
6415 look at the pattern. */
6416 if (TREE_CODE (arg) == TYPE_PACK_EXPANSION)
6417 arg = PACK_EXPANSION_PATTERN (arg);
6419 /* Deal with an injected-class-name used as a template template arg. */
6420 if (requires_tmpl_type && CLASS_TYPE_P (arg))
6422 tree t = maybe_get_template_decl_from_type_decl (TYPE_NAME (arg));
6423 if (TREE_CODE (t) == TEMPLATE_DECL)
6425 if (cxx_dialect >= cxx0x)
6426 /* OK under DR 1004. */;
6427 else if (complain & tf_warning_or_error)
6428 pedwarn (input_location, OPT_pedantic, "injected-class-name %qD"
6429 " used as template template argument", TYPE_NAME (arg));
6430 else if (flag_pedantic_errors)
6438 ((TREE_CODE (arg) == TEMPLATE_DECL
6439 && TREE_CODE (DECL_TEMPLATE_RESULT (arg)) == TYPE_DECL)
6440 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
6441 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE);
6444 && (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
6445 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE))
6446 arg = TYPE_STUB_DECL (arg);
6448 is_type = TYPE_P (arg) || is_tmpl_type;
6450 if (requires_type && ! is_type && TREE_CODE (arg) == SCOPE_REF
6451 && TREE_CODE (TREE_OPERAND (arg, 0)) == TEMPLATE_TYPE_PARM)
6453 if (TREE_CODE (TREE_OPERAND (arg, 1)) == BIT_NOT_EXPR)
6455 if (complain & tf_error)
6456 error ("invalid use of destructor %qE as a type", orig_arg);
6457 return error_mark_node;
6460 permerror (input_location,
6461 "to refer to a type member of a template parameter, "
6462 "use %<typename %E%>", orig_arg);
6464 orig_arg = make_typename_type (TREE_OPERAND (arg, 0),
6465 TREE_OPERAND (arg, 1),
6467 complain & tf_error);
6471 if (is_type != requires_type)
6475 if (complain & tf_error)
6477 error ("type/value mismatch at argument %d in template "
6478 "parameter list for %qD",
6481 error (" expected a constant of type %qT, got %qT",
6483 (DECL_P (arg) ? DECL_NAME (arg) : orig_arg));
6484 else if (requires_tmpl_type)
6485 error (" expected a class template, got %qE", orig_arg);
6487 error (" expected a type, got %qE", orig_arg);
6490 return error_mark_node;
6492 if (is_tmpl_type ^ requires_tmpl_type)
6494 if (in_decl && (complain & tf_error))
6496 error ("type/value mismatch at argument %d in template "
6497 "parameter list for %qD",
6500 error (" expected a type, got %qT", DECL_NAME (arg));
6502 error (" expected a class template, got %qT", orig_arg);
6504 return error_mark_node;
6509 if (requires_tmpl_type)
6511 if (TREE_CODE (TREE_TYPE (arg)) == UNBOUND_CLASS_TEMPLATE)
6512 /* The number of argument required is not known yet.
6513 Just accept it for now. */
6514 val = TREE_TYPE (arg);
6517 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
6520 argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
6522 if (coerce_template_template_parms (parmparm, argparm,
6528 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6530 if (val != error_mark_node)
6532 if (DECL_TEMPLATE_TEMPLATE_PARM_P (val))
6533 val = TREE_TYPE (val);
6534 if (TREE_CODE (orig_arg) == TYPE_PACK_EXPANSION)
6535 val = make_pack_expansion (val);
6540 if (in_decl && (complain & tf_error))
6542 error ("type/value mismatch at argument %d in "
6543 "template parameter list for %qD",
6545 error (" expected a template of type %qD, got %qT",
6549 val = error_mark_node;
6555 /* We only form one instance of each template specialization.
6556 Therefore, if we use a non-canonical variant (i.e., a
6557 typedef), any future messages referring to the type will use
6558 the typedef, which is confusing if those future uses do not
6559 themselves also use the typedef. */
6561 val = canonicalize_type_argument (val, complain);
6565 tree t = tsubst (TREE_TYPE (parm), args, complain, in_decl);
6567 if (invalid_nontype_parm_type_p (t, complain))
6568 return error_mark_node;
6570 if (template_parameter_pack_p (parm) && ARGUMENT_PACK_P (orig_arg))
6572 if (same_type_p (t, TREE_TYPE (orig_arg)))
6576 /* Not sure if this is reachable, but it doesn't hurt
6578 error ("type mismatch in nontype parameter pack");
6579 val = error_mark_node;
6582 else if (!uses_template_parms (orig_arg) && !uses_template_parms (t))
6583 /* We used to call digest_init here. However, digest_init
6584 will report errors, which we don't want when complain
6585 is zero. More importantly, digest_init will try too
6586 hard to convert things: for example, `0' should not be
6587 converted to pointer type at this point according to
6588 the standard. Accepting this is not merely an
6589 extension, since deciding whether or not these
6590 conversions can occur is part of determining which
6591 function template to call, or whether a given explicit
6592 argument specification is valid. */
6593 val = convert_nontype_argument (t, orig_arg, complain);
6597 if (val == NULL_TREE)
6598 val = error_mark_node;
6599 else if (val == error_mark_node && (complain & tf_error))
6600 error ("could not convert template argument %qE to %qT", orig_arg, t);
6602 if (TREE_CODE (val) == SCOPE_REF)
6604 /* Strip typedefs from the SCOPE_REF. */
6605 tree type = canonicalize_type_argument (TREE_TYPE (val), complain);
6606 tree scope = canonicalize_type_argument (TREE_OPERAND (val, 0),
6608 val = build_qualified_name (type, scope, TREE_OPERAND (val, 1),
6609 QUALIFIED_NAME_IS_TEMPLATE (val));
6616 /* Coerces the remaining template arguments in INNER_ARGS (from
6617 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6618 Returns the coerced argument pack. PARM_IDX is the position of this
6619 parameter in the template parameter list. ARGS is the original
6620 template argument list. */
6622 coerce_template_parameter_pack (tree parms,
6630 tsubst_flags_t complain)
6632 tree parm = TREE_VEC_ELT (parms, parm_idx);
6633 int nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
6636 tree packed_types = NULL_TREE;
6638 if (arg_idx > nargs)
6641 packed_args = make_tree_vec (nargs - arg_idx);
6643 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL
6644 && uses_parameter_packs (TREE_TYPE (TREE_VALUE (parm))))
6646 /* When the template parameter is a non-type template
6647 parameter pack whose type uses parameter packs, we need
6648 to look at each of the template arguments
6649 separately. Build a vector of the types for these
6650 non-type template parameters in PACKED_TYPES. */
6652 = make_pack_expansion (TREE_TYPE (TREE_VALUE (parm)));
6653 packed_types = tsubst_pack_expansion (expansion, args,
6656 if (packed_types == error_mark_node)
6657 return error_mark_node;
6659 /* Check that we have the right number of arguments. */
6661 && !PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx))
6662 && nargs - arg_idx != TREE_VEC_LENGTH (packed_types))
6665 = TREE_VEC_LENGTH (parms) - 1 + TREE_VEC_LENGTH (packed_types);
6666 error ("wrong number of template arguments (%d, should be %d)",
6667 nargs, needed_parms);
6668 return error_mark_node;
6671 /* If we aren't able to check the actual arguments now
6672 (because they haven't been expanded yet), we can at least
6673 verify that all of the types used for the non-type
6674 template parameter pack are, in fact, valid for non-type
6675 template parameters. */
6677 && PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx)))
6679 int j, len = TREE_VEC_LENGTH (packed_types);
6680 for (j = 0; j < len; ++j)
6682 tree t = TREE_VEC_ELT (packed_types, j);
6683 if (invalid_nontype_parm_type_p (t, complain))
6684 return error_mark_node;
6689 /* Convert the remaining arguments, which will be a part of the
6690 parameter pack "parm". */
6691 for (; arg_idx < nargs; ++arg_idx)
6693 tree arg = TREE_VEC_ELT (inner_args, arg_idx);
6694 tree actual_parm = TREE_VALUE (parm);
6696 if (packed_types && !PACK_EXPANSION_P (arg))
6698 /* When we have a vector of types (corresponding to the
6699 non-type template parameter pack that uses parameter
6700 packs in its type, as mention above), and the
6701 argument is not an expansion (which expands to a
6702 currently unknown number of arguments), clone the
6703 parm and give it the next type in PACKED_TYPES. */
6704 actual_parm = copy_node (actual_parm);
6705 TREE_TYPE (actual_parm) =
6706 TREE_VEC_ELT (packed_types, arg_idx - parm_idx);
6709 if (arg != error_mark_node)
6710 arg = convert_template_argument (actual_parm,
6711 arg, new_args, complain, parm_idx,
6713 if (arg == error_mark_node)
6715 TREE_VEC_ELT (packed_args, arg_idx - parm_idx) = arg;
6718 if (TREE_CODE (TREE_VALUE (parm)) == TYPE_DECL
6719 || TREE_CODE (TREE_VALUE (parm)) == TEMPLATE_DECL)
6720 argument_pack = cxx_make_type (TYPE_ARGUMENT_PACK);
6723 argument_pack = make_node (NONTYPE_ARGUMENT_PACK);
6724 TREE_TYPE (argument_pack)
6725 = tsubst (TREE_TYPE (TREE_VALUE (parm)), new_args, complain, in_decl);
6726 TREE_CONSTANT (argument_pack) = 1;
6729 SET_ARGUMENT_PACK_ARGS (argument_pack, packed_args);
6730 #ifdef ENABLE_CHECKING
6731 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (packed_args,
6732 TREE_VEC_LENGTH (packed_args));
6734 return argument_pack;
6737 /* Returns true if the template argument vector ARGS contains
6738 any pack expansions, false otherwise. */
6741 any_pack_expanson_args_p (tree args)
6745 for (i = 0; i < TREE_VEC_LENGTH (args); ++i)
6746 if (PACK_EXPANSION_P (TREE_VEC_ELT (args, i)))
6751 /* Convert all template arguments to their appropriate types, and
6752 return a vector containing the innermost resulting template
6753 arguments. If any error occurs, return error_mark_node. Error and
6754 warning messages are issued under control of COMPLAIN.
6756 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6757 for arguments not specified in ARGS. Otherwise, if
6758 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6759 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6760 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6764 coerce_template_parms (tree parms,
6767 tsubst_flags_t complain,
6768 bool require_all_args,
6769 bool use_default_args)
6771 int nparms, nargs, parm_idx, arg_idx, lost = 0;
6774 tree new_inner_args;
6775 int saved_unevaluated_operand;
6776 int saved_inhibit_evaluation_warnings;
6778 /* When used as a boolean value, indicates whether this is a
6779 variadic template parameter list. Since it's an int, we can also
6780 subtract it from nparms to get the number of non-variadic
6783 int post_variadic_parms = 0;
6785 if (args == error_mark_node)
6786 return error_mark_node;
6788 nparms = TREE_VEC_LENGTH (parms);
6790 /* Determine if there are any parameter packs. */
6791 for (parm_idx = 0; parm_idx < nparms; ++parm_idx)
6793 tree tparm = TREE_VALUE (TREE_VEC_ELT (parms, parm_idx));
6795 ++post_variadic_parms;
6796 if (template_parameter_pack_p (tparm))
6800 inner_args = INNERMOST_TEMPLATE_ARGS (args);
6801 /* If there are no parameters that follow a parameter pack, we need to
6802 expand any argument packs so that we can deduce a parameter pack from
6803 some non-packed args followed by an argument pack, as in variadic85.C.
6804 If there are such parameters, we need to leave argument packs intact
6805 so the arguments are assigned properly. This can happen when dealing
6806 with a nested class inside a partial specialization of a class
6807 template, as in variadic92.C, or when deducing a template parameter pack
6808 from a sub-declarator, as in variadic114.C. */
6809 if (!post_variadic_parms)
6810 inner_args = expand_template_argument_pack (inner_args);
6812 nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
6813 if ((nargs > nparms && !variadic_p)
6814 || (nargs < nparms - variadic_p
6816 && !any_pack_expanson_args_p (inner_args)
6817 && (!use_default_args
6818 || (TREE_VEC_ELT (parms, nargs) != error_mark_node
6819 && !TREE_PURPOSE (TREE_VEC_ELT (parms, nargs))))))
6821 if (complain & tf_error)
6825 nparms -= variadic_p;
6826 error ("wrong number of template arguments "
6827 "(%d, should be %d or more)", nargs, nparms);
6830 error ("wrong number of template arguments "
6831 "(%d, should be %d)", nargs, nparms);
6834 error ("provided for %q+D", in_decl);
6837 return error_mark_node;
6840 /* We need to evaluate the template arguments, even though this
6841 template-id may be nested within a "sizeof". */
6842 saved_unevaluated_operand = cp_unevaluated_operand;
6843 cp_unevaluated_operand = 0;
6844 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
6845 c_inhibit_evaluation_warnings = 0;
6846 new_inner_args = make_tree_vec (nparms);
6847 new_args = add_outermost_template_args (args, new_inner_args);
6848 for (parm_idx = 0, arg_idx = 0; parm_idx < nparms; parm_idx++, arg_idx++)
6853 /* Get the Ith template parameter. */
6854 parm = TREE_VEC_ELT (parms, parm_idx);
6856 if (parm == error_mark_node)
6858 TREE_VEC_ELT (new_inner_args, arg_idx) = error_mark_node;
6862 /* Calculate the next argument. */
6863 if (arg_idx < nargs)
6864 arg = TREE_VEC_ELT (inner_args, arg_idx);
6868 if (template_parameter_pack_p (TREE_VALUE (parm))
6869 && !(arg && ARGUMENT_PACK_P (arg)))
6871 /* All remaining arguments will be placed in the
6872 template parameter pack PARM. */
6873 arg = coerce_template_parameter_pack (parms, parm_idx, args,
6874 inner_args, arg_idx,
6878 /* Store this argument. */
6879 if (arg == error_mark_node)
6881 TREE_VEC_ELT (new_inner_args, parm_idx) = arg;
6883 /* We are done with all of the arguments. */
6890 if (PACK_EXPANSION_P (arg))
6892 /* We don't know how many args we have yet, just
6893 use the unconverted ones for now. */
6894 new_inner_args = inner_args;
6898 else if (require_all_args)
6900 /* There must be a default arg in this case. */
6901 arg = tsubst_template_arg (TREE_PURPOSE (parm), new_args,
6903 /* The position of the first default template argument,
6904 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6906 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args))
6907 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args, arg_idx);
6912 if (arg == error_mark_node)
6914 if (complain & tf_error)
6915 error ("template argument %d is invalid", arg_idx + 1);
6918 /* This only occurs if there was an error in the template
6919 parameter list itself (which we would already have
6920 reported) that we are trying to recover from, e.g., a class
6921 template with a parameter list such as
6922 template<typename..., typename>. */
6925 arg = convert_template_argument (TREE_VALUE (parm),
6926 arg, new_args, complain,
6929 if (arg == error_mark_node)
6931 TREE_VEC_ELT (new_inner_args, arg_idx) = arg;
6933 cp_unevaluated_operand = saved_unevaluated_operand;
6934 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
6937 return error_mark_node;
6939 #ifdef ENABLE_CHECKING
6940 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args))
6941 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args,
6942 TREE_VEC_LENGTH (new_inner_args));
6945 return new_inner_args;
6948 /* Returns 1 if template args OT and NT are equivalent. */
6951 template_args_equal (tree ot, tree nt)
6955 if (nt == NULL_TREE || ot == NULL_TREE)
6958 if (TREE_CODE (nt) == TREE_VEC)
6959 /* For member templates */
6960 return TREE_CODE (ot) == TREE_VEC && comp_template_args (ot, nt);
6961 else if (PACK_EXPANSION_P (ot))
6962 return (PACK_EXPANSION_P (nt)
6963 && template_args_equal (PACK_EXPANSION_PATTERN (ot),
6964 PACK_EXPANSION_PATTERN (nt))
6965 && template_args_equal (PACK_EXPANSION_EXTRA_ARGS (ot),
6966 PACK_EXPANSION_EXTRA_ARGS (nt)));
6967 else if (ARGUMENT_PACK_P (ot))
6972 if (!ARGUMENT_PACK_P (nt))
6975 opack = ARGUMENT_PACK_ARGS (ot);
6976 npack = ARGUMENT_PACK_ARGS (nt);
6977 len = TREE_VEC_LENGTH (opack);
6978 if (TREE_VEC_LENGTH (npack) != len)
6980 for (i = 0; i < len; ++i)
6981 if (!template_args_equal (TREE_VEC_ELT (opack, i),
6982 TREE_VEC_ELT (npack, i)))
6986 else if (ot && TREE_CODE (ot) == ARGUMENT_PACK_SELECT)
6988 /* We get here probably because we are in the middle of substituting
6989 into the pattern of a pack expansion. In that case the
6990 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
6991 interested in. So we want to use the initial pack argument for
6993 ot = ARGUMENT_PACK_SELECT_FROM_PACK (ot);
6994 if (nt && TREE_CODE (nt) == ARGUMENT_PACK_SELECT)
6995 nt = ARGUMENT_PACK_SELECT_FROM_PACK (nt);
6996 return template_args_equal (ot, nt);
6998 else if (TYPE_P (nt))
6999 return TYPE_P (ot) && same_type_p (ot, nt);
7000 else if (TREE_CODE (ot) == TREE_VEC || TYPE_P (ot))
7003 return cp_tree_equal (ot, nt);
7006 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets of
7007 template arguments. Returns 0 otherwise, and updates OLDARG_PTR and
7008 NEWARG_PTR with the offending arguments if they are non-NULL. */
7011 comp_template_args_with_info (tree oldargs, tree newargs,
7012 tree *oldarg_ptr, tree *newarg_ptr)
7016 if (oldargs == newargs)
7019 if (!oldargs || !newargs)
7022 if (TREE_VEC_LENGTH (oldargs) != TREE_VEC_LENGTH (newargs))
7025 for (i = 0; i < TREE_VEC_LENGTH (oldargs); ++i)
7027 tree nt = TREE_VEC_ELT (newargs, i);
7028 tree ot = TREE_VEC_ELT (oldargs, i);
7030 if (! template_args_equal (ot, nt))
7032 if (oldarg_ptr != NULL)
7034 if (newarg_ptr != NULL)
7042 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
7043 of template arguments. Returns 0 otherwise. */
7046 comp_template_args (tree oldargs, tree newargs)
7048 return comp_template_args_with_info (oldargs, newargs, NULL, NULL);
7052 add_pending_template (tree d)
7054 tree ti = (TYPE_P (d)
7055 ? CLASSTYPE_TEMPLATE_INFO (d)
7056 : DECL_TEMPLATE_INFO (d));
7057 struct pending_template *pt;
7060 if (TI_PENDING_TEMPLATE_FLAG (ti))
7063 /* We are called both from instantiate_decl, where we've already had a
7064 tinst_level pushed, and instantiate_template, where we haven't.
7066 level = !current_tinst_level || current_tinst_level->decl != d;
7069 push_tinst_level (d);
7071 pt = ggc_alloc_pending_template ();
7073 pt->tinst = current_tinst_level;
7074 if (last_pending_template)
7075 last_pending_template->next = pt;
7077 pending_templates = pt;
7079 last_pending_template = pt;
7081 TI_PENDING_TEMPLATE_FLAG (ti) = 1;
7088 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
7089 ARGLIST. Valid choices for FNS are given in the cp-tree.def
7090 documentation for TEMPLATE_ID_EXPR. */
7093 lookup_template_function (tree fns, tree arglist)
7097 if (fns == error_mark_node || arglist == error_mark_node)
7098 return error_mark_node;
7100 gcc_assert (!arglist || TREE_CODE (arglist) == TREE_VEC);
7102 if (!is_overloaded_fn (fns) && TREE_CODE (fns) != IDENTIFIER_NODE)
7104 error ("%q#D is not a function template", fns);
7105 return error_mark_node;
7108 if (BASELINK_P (fns))
7110 BASELINK_FUNCTIONS (fns) = build2 (TEMPLATE_ID_EXPR,
7112 BASELINK_FUNCTIONS (fns),
7117 type = TREE_TYPE (fns);
7118 if (TREE_CODE (fns) == OVERLOAD || !type)
7119 type = unknown_type_node;
7121 return build2 (TEMPLATE_ID_EXPR, type, fns, arglist);
7124 /* Within the scope of a template class S<T>, the name S gets bound
7125 (in build_self_reference) to a TYPE_DECL for the class, not a
7126 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
7127 or one of its enclosing classes, and that type is a template,
7128 return the associated TEMPLATE_DECL. Otherwise, the original
7131 Also handle the case when DECL is a TREE_LIST of ambiguous
7132 injected-class-names from different bases. */
7135 maybe_get_template_decl_from_type_decl (tree decl)
7137 if (decl == NULL_TREE)
7140 /* DR 176: A lookup that finds an injected-class-name (10.2
7141 [class.member.lookup]) can result in an ambiguity in certain cases
7142 (for example, if it is found in more than one base class). If all of
7143 the injected-class-names that are found refer to specializations of
7144 the same class template, and if the name is followed by a
7145 template-argument-list, the reference refers to the class template
7146 itself and not a specialization thereof, and is not ambiguous. */
7147 if (TREE_CODE (decl) == TREE_LIST)
7149 tree t, tmpl = NULL_TREE;
7150 for (t = decl; t; t = TREE_CHAIN (t))
7152 tree elt = maybe_get_template_decl_from_type_decl (TREE_VALUE (t));
7155 else if (tmpl != elt)
7158 if (tmpl && t == NULL_TREE)
7164 return (decl != NULL_TREE
7165 && DECL_SELF_REFERENCE_P (decl)
7166 && CLASSTYPE_TEMPLATE_INFO (TREE_TYPE (decl)))
7167 ? CLASSTYPE_TI_TEMPLATE (TREE_TYPE (decl)) : decl;
7170 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
7171 parameters, find the desired type.
7173 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
7175 IN_DECL, if non-NULL, is the template declaration we are trying to
7178 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
7179 the class we are looking up.
7181 Issue error and warning messages under control of COMPLAIN.
7183 If the template class is really a local class in a template
7184 function, then the FUNCTION_CONTEXT is the function in which it is
7187 ??? Note that this function is currently called *twice* for each
7188 template-id: the first time from the parser, while creating the
7189 incomplete type (finish_template_type), and the second type during the
7190 real instantiation (instantiate_template_class). This is surely something
7191 that we want to avoid. It also causes some problems with argument
7192 coercion (see convert_nontype_argument for more information on this). */
7195 lookup_template_class_1 (tree d1, tree arglist, tree in_decl, tree context,
7196 int entering_scope, tsubst_flags_t complain)
7198 tree templ = NULL_TREE, parmlist;
7205 if (TREE_CODE (d1) == IDENTIFIER_NODE)
7207 tree value = innermost_non_namespace_value (d1);
7208 if (value && DECL_TEMPLATE_TEMPLATE_PARM_P (value))
7213 push_decl_namespace (context);
7214 templ = lookup_name (d1);
7215 templ = maybe_get_template_decl_from_type_decl (templ);
7217 pop_decl_namespace ();
7220 context = DECL_CONTEXT (templ);
7222 else if (TREE_CODE (d1) == TYPE_DECL && MAYBE_CLASS_TYPE_P (TREE_TYPE (d1)))
7224 tree type = TREE_TYPE (d1);
7226 /* If we are declaring a constructor, say A<T>::A<T>, we will get
7227 an implicit typename for the second A. Deal with it. */
7228 if (TREE_CODE (type) == TYPENAME_TYPE && TREE_TYPE (type))
7229 type = TREE_TYPE (type);
7231 if (CLASSTYPE_TEMPLATE_INFO (type))
7233 templ = CLASSTYPE_TI_TEMPLATE (type);
7234 d1 = DECL_NAME (templ);
7237 else if (TREE_CODE (d1) == ENUMERAL_TYPE
7238 || (TYPE_P (d1) && MAYBE_CLASS_TYPE_P (d1)))
7240 templ = TYPE_TI_TEMPLATE (d1);
7241 d1 = DECL_NAME (templ);
7243 else if (TREE_CODE (d1) == TEMPLATE_DECL
7244 && DECL_TEMPLATE_RESULT (d1)
7245 && TREE_CODE (DECL_TEMPLATE_RESULT (d1)) == TYPE_DECL)
7248 d1 = DECL_NAME (templ);
7249 context = DECL_CONTEXT (templ);
7252 /* Issue an error message if we didn't find a template. */
7255 if (complain & tf_error)
7256 error ("%qT is not a template", d1);
7257 return error_mark_node;
7260 if (TREE_CODE (templ) != TEMPLATE_DECL
7261 /* Make sure it's a user visible template, if it was named by
7263 || ((complain & tf_user) && !DECL_TEMPLATE_PARM_P (templ)
7264 && !PRIMARY_TEMPLATE_P (templ)))
7266 if (complain & tf_error)
7268 error ("non-template type %qT used as a template", d1);
7270 error ("for template declaration %q+D", in_decl);
7272 return error_mark_node;
7275 complain &= ~tf_user;
7277 if (DECL_TEMPLATE_TEMPLATE_PARM_P (templ))
7279 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
7280 template arguments */
7286 parmlist = DECL_INNERMOST_TEMPLATE_PARMS (templ);
7288 /* Consider an example where a template template parameter declared as
7290 template <class T, class U = std::allocator<T> > class TT
7292 The template parameter level of T and U are one level larger than
7293 of TT. To proper process the default argument of U, say when an
7294 instantiation `TT<int>' is seen, we need to build the full
7295 arguments containing {int} as the innermost level. Outer levels,
7296 available when not appearing as default template argument, can be
7297 obtained from the arguments of the enclosing template.
7299 Suppose that TT is later substituted with std::vector. The above
7300 instantiation is `TT<int, std::allocator<T> >' with TT at
7301 level 1, and T at level 2, while the template arguments at level 1
7302 becomes {std::vector} and the inner level 2 is {int}. */
7304 outer = DECL_CONTEXT (templ);
7306 outer = TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (outer)));
7307 else if (current_template_parms)
7308 /* This is an argument of the current template, so we haven't set
7309 DECL_CONTEXT yet. */
7310 outer = current_template_args ();
7313 arglist = add_to_template_args (outer, arglist);
7315 arglist2 = coerce_template_parms (parmlist, arglist, templ,
7317 /*require_all_args=*/true,
7318 /*use_default_args=*/true);
7319 if (arglist2 == error_mark_node
7320 || (!uses_template_parms (arglist2)
7321 && check_instantiated_args (templ, arglist2, complain)))
7322 return error_mark_node;
7324 parm = bind_template_template_parm (TREE_TYPE (templ), arglist2);
7329 tree template_type = TREE_TYPE (templ);
7332 tree found = NULL_TREE;
7335 int is_dependent_type;
7336 int use_partial_inst_tmpl = false;
7338 if (template_type == error_mark_node)
7339 /* An error occured while building the template TEMPL, and a
7340 diagnostic has most certainly been emitted for that
7341 already. Let's propagate that error. */
7342 return error_mark_node;
7344 gen_tmpl = most_general_template (templ);
7345 parmlist = DECL_TEMPLATE_PARMS (gen_tmpl);
7346 parm_depth = TMPL_PARMS_DEPTH (parmlist);
7347 arg_depth = TMPL_ARGS_DEPTH (arglist);
7349 if (arg_depth == 1 && parm_depth > 1)
7351 /* We've been given an incomplete set of template arguments.
7354 template <class T> struct S1 {
7355 template <class U> struct S2 {};
7356 template <class U> struct S2<U*> {};
7359 we will be called with an ARGLIST of `U*', but the
7360 TEMPLATE will be `template <class T> template
7361 <class U> struct S1<T>::S2'. We must fill in the missing
7364 = add_outermost_template_args (TYPE_TI_ARGS (TREE_TYPE (templ)),
7366 arg_depth = TMPL_ARGS_DEPTH (arglist);
7369 /* Now we should have enough arguments. */
7370 gcc_assert (parm_depth == arg_depth);
7372 /* From here on, we're only interested in the most general
7375 /* Calculate the BOUND_ARGS. These will be the args that are
7376 actually tsubst'd into the definition to create the
7380 /* We have multiple levels of arguments to coerce, at once. */
7382 int saved_depth = TMPL_ARGS_DEPTH (arglist);
7384 tree bound_args = make_tree_vec (parm_depth);
7386 for (i = saved_depth,
7387 t = DECL_TEMPLATE_PARMS (gen_tmpl);
7388 i > 0 && t != NULL_TREE;
7389 --i, t = TREE_CHAIN (t))
7392 if (i == saved_depth)
7393 a = coerce_template_parms (TREE_VALUE (t),
7396 /*require_all_args=*/true,
7397 /*use_default_args=*/true);
7399 /* Outer levels should have already been coerced. */
7400 a = TMPL_ARGS_LEVEL (arglist, i);
7402 /* Don't process further if one of the levels fails. */
7403 if (a == error_mark_node)
7405 /* Restore the ARGLIST to its full size. */
7406 TREE_VEC_LENGTH (arglist) = saved_depth;
7407 return error_mark_node;
7410 SET_TMPL_ARGS_LEVEL (bound_args, i, a);
7412 /* We temporarily reduce the length of the ARGLIST so
7413 that coerce_template_parms will see only the arguments
7414 corresponding to the template parameters it is
7416 TREE_VEC_LENGTH (arglist)--;
7419 /* Restore the ARGLIST to its full size. */
7420 TREE_VEC_LENGTH (arglist) = saved_depth;
7422 arglist = bound_args;
7426 = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parmlist),
7427 INNERMOST_TEMPLATE_ARGS (arglist),
7430 /*require_all_args=*/true,
7431 /*use_default_args=*/true);
7433 if (arglist == error_mark_node)
7434 /* We were unable to bind the arguments. */
7435 return error_mark_node;
7437 /* In the scope of a template class, explicit references to the
7438 template class refer to the type of the template, not any
7439 instantiation of it. For example, in:
7441 template <class T> class C { void f(C<T>); }
7443 the `C<T>' is just the same as `C'. Outside of the
7444 class, however, such a reference is an instantiation. */
7446 || !PRIMARY_TEMPLATE_P (gen_tmpl)
7447 || currently_open_class (template_type))
7448 /* comp_template_args is expensive, check it last. */
7449 && comp_template_args (TYPE_TI_ARGS (template_type),
7451 return template_type;
7453 /* If we already have this specialization, return it. */
7454 elt.tmpl = gen_tmpl;
7456 hash = hash_specialization (&elt);
7457 entry = (spec_entry *) htab_find_with_hash (type_specializations,
7463 is_dependent_type = uses_template_parms (arglist);
7465 /* If the deduced arguments are invalid, then the binding
7467 if (!is_dependent_type
7468 && check_instantiated_args (gen_tmpl,
7469 INNERMOST_TEMPLATE_ARGS (arglist),
7471 return error_mark_node;
7473 if (!is_dependent_type
7474 && !PRIMARY_TEMPLATE_P (gen_tmpl)
7475 && !LAMBDA_TYPE_P (TREE_TYPE (gen_tmpl))
7476 && TREE_CODE (CP_DECL_CONTEXT (gen_tmpl)) == NAMESPACE_DECL)
7478 found = xref_tag_from_type (TREE_TYPE (gen_tmpl),
7479 DECL_NAME (gen_tmpl),
7480 /*tag_scope=*/ts_global);
7484 context = tsubst (DECL_CONTEXT (gen_tmpl), arglist,
7486 if (context == error_mark_node)
7487 return error_mark_node;
7490 context = global_namespace;
7492 /* Create the type. */
7493 if (TREE_CODE (template_type) == ENUMERAL_TYPE)
7495 if (!is_dependent_type)
7497 set_current_access_from_decl (TYPE_NAME (template_type));
7498 t = start_enum (TYPE_IDENTIFIER (template_type), NULL_TREE,
7499 tsubst (ENUM_UNDERLYING_TYPE (template_type),
7500 arglist, complain, in_decl),
7501 SCOPED_ENUM_P (template_type), NULL);
7505 /* We don't want to call start_enum for this type, since
7506 the values for the enumeration constants may involve
7507 template parameters. And, no one should be interested
7508 in the enumeration constants for such a type. */
7509 t = cxx_make_type (ENUMERAL_TYPE);
7510 SET_SCOPED_ENUM_P (t, SCOPED_ENUM_P (template_type));
7512 SET_OPAQUE_ENUM_P (t, OPAQUE_ENUM_P (template_type));
7513 ENUM_FIXED_UNDERLYING_TYPE_P (t)
7514 = ENUM_FIXED_UNDERLYING_TYPE_P (template_type);
7516 else if (DECL_ALIAS_TEMPLATE_P (gen_tmpl))
7518 /* The user referred to a specialization of an alias
7519 template represented by GEN_TMPL.
7521 [temp.alias]/2 says:
7523 When a template-id refers to the specialization of an
7524 alias template, it is equivalent to the associated
7525 type obtained by substitution of its
7526 template-arguments for the template-parameters in the
7527 type-id of the alias template. */
7529 t = tsubst (TREE_TYPE (gen_tmpl), arglist, complain, in_decl);
7530 /* Note that the call above (by indirectly calling
7531 register_specialization in tsubst_decl) registers the
7532 TYPE_DECL representing the specialization of the alias
7533 template. So next time someone substitutes ARGLIST for
7534 the template parms into the alias template (GEN_TMPL),
7535 she'll get that TYPE_DECL back. */
7537 if (t == error_mark_node)
7540 else if (CLASS_TYPE_P (template_type))
7542 t = make_class_type (TREE_CODE (template_type));
7543 CLASSTYPE_DECLARED_CLASS (t)
7544 = CLASSTYPE_DECLARED_CLASS (template_type);
7545 SET_CLASSTYPE_IMPLICIT_INSTANTIATION (t);
7546 TYPE_FOR_JAVA (t) = TYPE_FOR_JAVA (template_type);
7548 /* A local class. Make sure the decl gets registered properly. */
7549 if (context == current_function_decl)
7550 pushtag (DECL_NAME (gen_tmpl), t, /*tag_scope=*/ts_current);
7552 if (comp_template_args (CLASSTYPE_TI_ARGS (template_type), arglist))
7553 /* This instantiation is another name for the primary
7554 template type. Set the TYPE_CANONICAL field
7556 TYPE_CANONICAL (t) = template_type;
7557 else if (any_template_arguments_need_structural_equality_p (arglist))
7558 /* Some of the template arguments require structural
7559 equality testing, so this template class requires
7560 structural equality testing. */
7561 SET_TYPE_STRUCTURAL_EQUALITY (t);
7566 /* If we called start_enum or pushtag above, this information
7567 will already be set up. */
7570 TYPE_CONTEXT (t) = FROB_CONTEXT (context);
7572 type_decl = create_implicit_typedef (DECL_NAME (gen_tmpl), t);
7573 DECL_CONTEXT (type_decl) = TYPE_CONTEXT (t);
7574 DECL_SOURCE_LOCATION (type_decl)
7575 = DECL_SOURCE_LOCATION (TYPE_STUB_DECL (template_type));
7578 type_decl = TYPE_NAME (t);
7580 if (CLASS_TYPE_P (template_type))
7582 TREE_PRIVATE (type_decl)
7583 = TREE_PRIVATE (TYPE_STUB_DECL (template_type));
7584 TREE_PROTECTED (type_decl)
7585 = TREE_PROTECTED (TYPE_STUB_DECL (template_type));
7586 if (CLASSTYPE_VISIBILITY_SPECIFIED (template_type))
7588 DECL_VISIBILITY_SPECIFIED (type_decl) = 1;
7589 DECL_VISIBILITY (type_decl) = CLASSTYPE_VISIBILITY (template_type);
7593 /* Let's consider the explicit specialization of a member
7594 of a class template specialization that is implicitely instantiated,
7599 template<class U> struct M {}; //#0
7604 struct S<int>::M<char> //#1
7608 [temp.expl.spec]/4 says this is valid.
7610 In this case, when we write:
7613 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7616 When we encounter #1, we want to store the partial instantiation
7617 of M (template<class T> S<int>::M<T>) in it's CLASSTYPE_TI_TEMPLATE.
7619 For all cases other than this "explicit specialization of member of a
7620 class template", we just want to store the most general template into
7621 the CLASSTYPE_TI_TEMPLATE of M.
7623 This case of "explicit specialization of member of a class template"
7625 1/ the enclosing class is an instantiation of, and therefore not
7626 the same as, the context of the most general template, and
7627 2/ we aren't looking at the partial instantiation itself, i.e.
7628 the innermost arguments are not the same as the innermost parms of
7629 the most general template.
7631 So it's only when 1/ and 2/ happens that we want to use the partial
7632 instantiation of the member template in lieu of its most general
7635 if (PRIMARY_TEMPLATE_P (gen_tmpl)
7636 && TMPL_ARGS_HAVE_MULTIPLE_LEVELS (arglist)
7637 /* the enclosing class must be an instantiation... */
7638 && CLASS_TYPE_P (context)
7639 && !same_type_p (context, DECL_CONTEXT (gen_tmpl)))
7641 tree partial_inst_args;
7642 TREE_VEC_LENGTH (arglist)--;
7643 ++processing_template_decl;
7645 tsubst (INNERMOST_TEMPLATE_ARGS
7646 (TYPE_TI_ARGS (TREE_TYPE (gen_tmpl))),
7647 arglist, complain, NULL_TREE);
7648 --processing_template_decl;
7649 TREE_VEC_LENGTH (arglist)++;
7650 use_partial_inst_tmpl =
7651 /*...and we must not be looking at the partial instantiation
7653 !comp_template_args (INNERMOST_TEMPLATE_ARGS (arglist),
7657 if (!use_partial_inst_tmpl)
7658 /* This case is easy; there are no member templates involved. */
7662 /* This is a full instantiation of a member template. Find
7663 the partial instantiation of which this is an instance. */
7665 /* Temporarily reduce by one the number of levels in the ARGLIST
7666 so as to avoid comparing the last set of arguments. */
7667 TREE_VEC_LENGTH (arglist)--;
7668 found = tsubst (gen_tmpl, arglist, complain, NULL_TREE);
7669 TREE_VEC_LENGTH (arglist)++;
7670 /* FOUND is either a proper class type, or an alias
7671 template specialization. In the later case, it's a
7672 TYPE_DECL, resulting from the substituting of arguments
7673 for parameters in the TYPE_DECL of the alias template
7674 done earlier. So be careful while getting the template
7676 found = TREE_CODE (found) == TYPE_DECL
7677 ? TYPE_TI_TEMPLATE (TREE_TYPE (found))
7678 : CLASSTYPE_TI_TEMPLATE (found);
7681 SET_TYPE_TEMPLATE_INFO (t, build_template_info (found, arglist));
7684 slot = htab_find_slot_with_hash (type_specializations,
7685 &elt, hash, INSERT);
7686 entry = ggc_alloc_spec_entry ();
7690 /* Note this use of the partial instantiation so we can check it
7691 later in maybe_process_partial_specialization. */
7692 DECL_TEMPLATE_INSTANTIATIONS (templ)
7693 = tree_cons (arglist, t,
7694 DECL_TEMPLATE_INSTANTIATIONS (templ));
7696 if (TREE_CODE (t) == ENUMERAL_TYPE && !is_dependent_type)
7697 /* Now that the type has been registered on the instantiations
7698 list, we set up the enumerators. Because the enumeration
7699 constants may involve the enumeration type itself, we make
7700 sure to register the type first, and then create the
7701 constants. That way, doing tsubst_expr for the enumeration
7702 constants won't result in recursive calls here; we'll find
7703 the instantiation and exit above. */
7704 tsubst_enum (template_type, t, arglist);
7706 if (CLASS_TYPE_P (template_type) && is_dependent_type)
7707 /* If the type makes use of template parameters, the
7708 code that generates debugging information will crash. */
7709 DECL_IGNORED_P (TYPE_STUB_DECL (t)) = 1;
7711 /* Possibly limit visibility based on template args. */
7712 TREE_PUBLIC (type_decl) = 1;
7713 determine_visibility (type_decl);
7719 /* Wrapper for lookup_template_class_1. */
7722 lookup_template_class (tree d1, tree arglist, tree in_decl, tree context,
7723 int entering_scope, tsubst_flags_t complain)
7726 timevar_push (TV_TEMPLATE_INST);
7727 ret = lookup_template_class_1 (d1, arglist, in_decl, context,
7728 entering_scope, complain);
7729 timevar_pop (TV_TEMPLATE_INST);
7737 /* True when we should also visit template parameters that occur in
7738 non-deduced contexts. */
7739 bool include_nondeduced_p;
7740 struct pointer_set_t *visited;
7743 /* Called from for_each_template_parm via walk_tree. */
7746 for_each_template_parm_r (tree *tp, int *walk_subtrees, void *d)
7749 struct pair_fn_data *pfd = (struct pair_fn_data *) d;
7750 tree_fn_t fn = pfd->fn;
7751 void *data = pfd->data;
7754 && (pfd->include_nondeduced_p || TREE_CODE (t) != TYPENAME_TYPE)
7755 && for_each_template_parm (TYPE_CONTEXT (t), fn, data, pfd->visited,
7756 pfd->include_nondeduced_p))
7757 return error_mark_node;
7759 switch (TREE_CODE (t))
7762 if (TYPE_PTRMEMFUNC_P (t))
7768 if (!TYPE_TEMPLATE_INFO (t))
7770 else if (for_each_template_parm (TI_ARGS (TYPE_TEMPLATE_INFO (t)),
7771 fn, data, pfd->visited,
7772 pfd->include_nondeduced_p))
7773 return error_mark_node;
7777 if (for_each_template_parm (TYPE_MIN_VALUE (t),
7778 fn, data, pfd->visited,
7779 pfd->include_nondeduced_p)
7780 || for_each_template_parm (TYPE_MAX_VALUE (t),
7781 fn, data, pfd->visited,
7782 pfd->include_nondeduced_p))
7783 return error_mark_node;
7787 /* Since we're not going to walk subtrees, we have to do this
7789 if (for_each_template_parm (TYPE_METHOD_BASETYPE (t), fn, data,
7790 pfd->visited, pfd->include_nondeduced_p))
7791 return error_mark_node;
7795 /* Check the return type. */
7796 if (for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
7797 pfd->include_nondeduced_p))
7798 return error_mark_node;
7800 /* Check the parameter types. Since default arguments are not
7801 instantiated until they are needed, the TYPE_ARG_TYPES may
7802 contain expressions that involve template parameters. But,
7803 no-one should be looking at them yet. And, once they're
7804 instantiated, they don't contain template parameters, so
7805 there's no point in looking at them then, either. */
7809 for (parm = TYPE_ARG_TYPES (t); parm; parm = TREE_CHAIN (parm))
7810 if (for_each_template_parm (TREE_VALUE (parm), fn, data,
7811 pfd->visited, pfd->include_nondeduced_p))
7812 return error_mark_node;
7814 /* Since we've already handled the TYPE_ARG_TYPES, we don't
7815 want walk_tree walking into them itself. */
7821 case UNDERLYING_TYPE:
7822 if (pfd->include_nondeduced_p
7823 && for_each_template_parm (TYPE_FIELDS (t), fn, data,
7825 pfd->include_nondeduced_p))
7826 return error_mark_node;
7831 if (DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t)
7832 && for_each_template_parm (DECL_TI_ARGS (t), fn, data,
7833 pfd->visited, pfd->include_nondeduced_p))
7834 return error_mark_node;
7839 if (TREE_CODE (t) == CONST_DECL && DECL_TEMPLATE_PARM_P (t)
7840 && for_each_template_parm (DECL_INITIAL (t), fn, data,
7841 pfd->visited, pfd->include_nondeduced_p))
7842 return error_mark_node;
7843 if (DECL_CONTEXT (t)
7844 && pfd->include_nondeduced_p
7845 && for_each_template_parm (DECL_CONTEXT (t), fn, data,
7846 pfd->visited, pfd->include_nondeduced_p))
7847 return error_mark_node;
7850 case BOUND_TEMPLATE_TEMPLATE_PARM:
7851 /* Record template parameters such as `T' inside `TT<T>'. */
7852 if (for_each_template_parm (TYPE_TI_ARGS (t), fn, data, pfd->visited,
7853 pfd->include_nondeduced_p))
7854 return error_mark_node;
7857 case TEMPLATE_TEMPLATE_PARM:
7858 case TEMPLATE_TYPE_PARM:
7859 case TEMPLATE_PARM_INDEX:
7860 if (fn && (*fn)(t, data))
7861 return error_mark_node;
7863 return error_mark_node;
7867 /* A template template parameter is encountered. */
7868 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t)
7869 && for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
7870 pfd->include_nondeduced_p))
7871 return error_mark_node;
7873 /* Already substituted template template parameter */
7879 || for_each_template_parm (TYPENAME_TYPE_FULLNAME (t), fn,
7881 pfd->include_nondeduced_p))
7882 return error_mark_node;
7886 if (TREE_TYPE (t) && TYPE_PTRMEMFUNC_P (TREE_TYPE (t))
7887 && pfd->include_nondeduced_p
7888 && for_each_template_parm (TYPE_PTRMEMFUNC_FN_TYPE
7889 (TREE_TYPE (t)), fn, data,
7890 pfd->visited, pfd->include_nondeduced_p))
7891 return error_mark_node;
7896 /* If there's no type, then this thing must be some expression
7897 involving template parameters. */
7898 if (!fn && !TREE_TYPE (t))
7899 return error_mark_node;
7904 case IMPLICIT_CONV_EXPR:
7905 case REINTERPRET_CAST_EXPR:
7906 case CONST_CAST_EXPR:
7907 case STATIC_CAST_EXPR:
7908 case DYNAMIC_CAST_EXPR:
7912 case PSEUDO_DTOR_EXPR:
7914 return error_mark_node;
7921 /* We didn't find any template parameters we liked. */
7925 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
7926 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
7927 call FN with the parameter and the DATA.
7928 If FN returns nonzero, the iteration is terminated, and
7929 for_each_template_parm returns 1. Otherwise, the iteration
7930 continues. If FN never returns a nonzero value, the value
7931 returned by for_each_template_parm is 0. If FN is NULL, it is
7932 considered to be the function which always returns 1.
7934 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
7935 parameters that occur in non-deduced contexts. When false, only
7936 visits those template parameters that can be deduced. */
7939 for_each_template_parm (tree t, tree_fn_t fn, void* data,
7940 struct pointer_set_t *visited,
7941 bool include_nondeduced_p)
7943 struct pair_fn_data pfd;
7949 pfd.include_nondeduced_p = include_nondeduced_p;
7951 /* Walk the tree. (Conceptually, we would like to walk without
7952 duplicates, but for_each_template_parm_r recursively calls
7953 for_each_template_parm, so we would need to reorganize a fair
7954 bit to use walk_tree_without_duplicates, so we keep our own
7957 pfd.visited = visited;
7959 pfd.visited = pointer_set_create ();
7960 result = cp_walk_tree (&t,
7961 for_each_template_parm_r,
7963 pfd.visited) != NULL_TREE;
7968 pointer_set_destroy (pfd.visited);
7975 /* Returns true if T depends on any template parameter. */
7978 uses_template_parms (tree t)
7981 int saved_processing_template_decl;
7983 saved_processing_template_decl = processing_template_decl;
7984 if (!saved_processing_template_decl)
7985 processing_template_decl = 1;
7987 dependent_p = dependent_type_p (t);
7988 else if (TREE_CODE (t) == TREE_VEC)
7989 dependent_p = any_dependent_template_arguments_p (t);
7990 else if (TREE_CODE (t) == TREE_LIST)
7991 dependent_p = (uses_template_parms (TREE_VALUE (t))
7992 || uses_template_parms (TREE_CHAIN (t)));
7993 else if (TREE_CODE (t) == TYPE_DECL)
7994 dependent_p = dependent_type_p (TREE_TYPE (t));
7997 || TREE_CODE (t) == TEMPLATE_PARM_INDEX
7998 || TREE_CODE (t) == OVERLOAD
8000 || TREE_CODE (t) == IDENTIFIER_NODE
8001 || TREE_CODE (t) == TRAIT_EXPR
8002 || TREE_CODE (t) == CONSTRUCTOR
8003 || CONSTANT_CLASS_P (t))
8004 dependent_p = (type_dependent_expression_p (t)
8005 || value_dependent_expression_p (t));
8008 gcc_assert (t == error_mark_node);
8009 dependent_p = false;
8012 processing_template_decl = saved_processing_template_decl;
8017 /* Returns true if T depends on any template parameter with level LEVEL. */
8020 uses_template_parms_level (tree t, int level)
8022 return for_each_template_parm (t, template_parm_this_level_p, &level, NULL,
8023 /*include_nondeduced_p=*/true);
8026 /* Returns TRUE iff INST is an instantiation we don't need to do in an
8027 ill-formed translation unit, i.e. a variable or function that isn't
8028 usable in a constant expression. */
8031 neglectable_inst_p (tree d)
8034 && !(TREE_CODE (d) == FUNCTION_DECL ? DECL_DECLARED_CONSTEXPR_P (d)
8035 : decl_maybe_constant_var_p (d)));
8038 /* Returns TRUE iff we should refuse to instantiate DECL because it's
8039 neglectable and instantiated from within an erroneous instantiation. */
8042 limit_bad_template_recursion (tree decl)
8044 struct tinst_level *lev = current_tinst_level;
8045 int errs = errorcount + sorrycount;
8046 if (lev == NULL || errs == 0 || !neglectable_inst_p (decl))
8049 for (; lev; lev = lev->next)
8050 if (neglectable_inst_p (lev->decl))
8053 return (lev && errs > lev->errors);
8056 static int tinst_depth;
8057 extern int max_tinst_depth;
8058 #ifdef GATHER_STATISTICS
8061 static GTY(()) struct tinst_level *last_error_tinst_level;
8063 /* We're starting to instantiate D; record the template instantiation context
8064 for diagnostics and to restore it later. */
8067 push_tinst_level (tree d)
8069 struct tinst_level *new_level;
8071 if (tinst_depth >= max_tinst_depth)
8073 last_error_tinst_level = current_tinst_level;
8074 if (TREE_CODE (d) == TREE_LIST)
8075 error ("template instantiation depth exceeds maximum of %d (use "
8076 "-ftemplate-depth= to increase the maximum) substituting %qS",
8077 max_tinst_depth, d);
8079 error ("template instantiation depth exceeds maximum of %d (use "
8080 "-ftemplate-depth= to increase the maximum) instantiating %qD",
8081 max_tinst_depth, d);
8083 print_instantiation_context ();
8088 /* If the current instantiation caused problems, don't let it instantiate
8089 anything else. Do allow deduction substitution and decls usable in
8090 constant expressions. */
8091 if (limit_bad_template_recursion (d))
8094 new_level = ggc_alloc_tinst_level ();
8095 new_level->decl = d;
8096 new_level->locus = input_location;
8097 new_level->errors = errorcount+sorrycount;
8098 new_level->in_system_header_p = in_system_header;
8099 new_level->next = current_tinst_level;
8100 current_tinst_level = new_level;
8103 #ifdef GATHER_STATISTICS
8104 if (tinst_depth > depth_reached)
8105 depth_reached = tinst_depth;
8111 /* We're done instantiating this template; return to the instantiation
8115 pop_tinst_level (void)
8117 /* Restore the filename and line number stashed away when we started
8118 this instantiation. */
8119 input_location = current_tinst_level->locus;
8120 current_tinst_level = current_tinst_level->next;
8124 /* We're instantiating a deferred template; restore the template
8125 instantiation context in which the instantiation was requested, which
8126 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
8129 reopen_tinst_level (struct tinst_level *level)
8131 struct tinst_level *t;
8134 for (t = level; t; t = t->next)
8137 current_tinst_level = level;
8139 if (current_tinst_level)
8140 current_tinst_level->errors = errorcount+sorrycount;
8144 /* Returns the TINST_LEVEL which gives the original instantiation
8147 struct tinst_level *
8148 outermost_tinst_level (void)
8150 struct tinst_level *level = current_tinst_level;
8153 level = level->next;
8157 /* Returns TRUE if PARM is a parameter of the template TEMPL. */
8160 parameter_of_template_p (tree parm, tree templ)
8165 if (!parm || !templ)
8168 gcc_assert (DECL_TEMPLATE_PARM_P (parm));
8169 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
8171 parms = DECL_TEMPLATE_PARMS (templ);
8172 parms = INNERMOST_TEMPLATE_PARMS (parms);
8174 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
8176 tree p = TREE_VALUE (TREE_VEC_ELT (parms, i));
8177 if (p == error_mark_node)
8181 || (DECL_INITIAL (parm)
8182 && DECL_INITIAL (parm) == DECL_INITIAL (p)))
8189 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
8190 vector of template arguments, as for tsubst.
8192 Returns an appropriate tsubst'd friend declaration. */
8195 tsubst_friend_function (tree decl, tree args)
8199 if (TREE_CODE (decl) == FUNCTION_DECL
8200 && DECL_TEMPLATE_INSTANTIATION (decl)
8201 && TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
8202 /* This was a friend declared with an explicit template
8203 argument list, e.g.:
8207 to indicate that f was a template instantiation, not a new
8208 function declaration. Now, we have to figure out what
8209 instantiation of what template. */
8211 tree template_id, arglist, fns;
8214 tree ns = decl_namespace_context (TYPE_MAIN_DECL (current_class_type));
8216 /* Friend functions are looked up in the containing namespace scope.
8217 We must enter that scope, to avoid finding member functions of the
8218 current class with same name. */
8219 push_nested_namespace (ns);
8220 fns = tsubst_expr (DECL_TI_TEMPLATE (decl), args,
8221 tf_warning_or_error, NULL_TREE,
8222 /*integral_constant_expression_p=*/false);
8223 pop_nested_namespace (ns);
8224 arglist = tsubst (DECL_TI_ARGS (decl), args,
8225 tf_warning_or_error, NULL_TREE);
8226 template_id = lookup_template_function (fns, arglist);
8228 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
8229 tmpl = determine_specialization (template_id, new_friend,
8231 /*need_member_template=*/0,
8232 TREE_VEC_LENGTH (args),
8234 return instantiate_template (tmpl, new_args, tf_error);
8237 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
8239 /* The NEW_FRIEND will look like an instantiation, to the
8240 compiler, but is not an instantiation from the point of view of
8241 the language. For example, we might have had:
8243 template <class T> struct S {
8244 template <class U> friend void f(T, U);
8247 Then, in S<int>, template <class U> void f(int, U) is not an
8248 instantiation of anything. */
8249 if (new_friend == error_mark_node)
8250 return error_mark_node;
8252 DECL_USE_TEMPLATE (new_friend) = 0;
8253 if (TREE_CODE (decl) == TEMPLATE_DECL)
8255 DECL_USE_TEMPLATE (DECL_TEMPLATE_RESULT (new_friend)) = 0;
8256 DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (new_friend))
8257 = DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (decl));
8260 /* The mangled name for the NEW_FRIEND is incorrect. The function
8261 is not a template instantiation and should not be mangled like
8262 one. Therefore, we forget the mangling here; we'll recompute it
8263 later if we need it. */
8264 if (TREE_CODE (new_friend) != TEMPLATE_DECL)
8266 SET_DECL_RTL (new_friend, NULL);
8267 SET_DECL_ASSEMBLER_NAME (new_friend, NULL_TREE);
8270 if (DECL_NAMESPACE_SCOPE_P (new_friend))
8273 tree new_friend_template_info;
8274 tree new_friend_result_template_info;
8276 int new_friend_is_defn;
8278 /* We must save some information from NEW_FRIEND before calling
8279 duplicate decls since that function will free NEW_FRIEND if
8281 new_friend_template_info = DECL_TEMPLATE_INFO (new_friend);
8282 new_friend_is_defn =
8283 (DECL_INITIAL (DECL_TEMPLATE_RESULT
8284 (template_for_substitution (new_friend)))
8286 if (TREE_CODE (new_friend) == TEMPLATE_DECL)
8288 /* This declaration is a `primary' template. */
8289 DECL_PRIMARY_TEMPLATE (new_friend) = new_friend;
8291 new_friend_result_template_info
8292 = DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (new_friend));
8295 new_friend_result_template_info = NULL_TREE;
8297 /* Make the init_value nonzero so pushdecl knows this is a defn. */
8298 if (new_friend_is_defn)
8299 DECL_INITIAL (new_friend) = error_mark_node;
8301 /* Inside pushdecl_namespace_level, we will push into the
8302 current namespace. However, the friend function should go
8303 into the namespace of the template. */
8304 ns = decl_namespace_context (new_friend);
8305 push_nested_namespace (ns);
8306 old_decl = pushdecl_namespace_level (new_friend, /*is_friend=*/true);
8307 pop_nested_namespace (ns);
8309 if (old_decl == error_mark_node)
8310 return error_mark_node;
8312 if (old_decl != new_friend)
8314 /* This new friend declaration matched an existing
8315 declaration. For example, given:
8317 template <class T> void f(T);
8318 template <class U> class C {
8319 template <class T> friend void f(T) {}
8322 the friend declaration actually provides the definition
8323 of `f', once C has been instantiated for some type. So,
8324 old_decl will be the out-of-class template declaration,
8325 while new_friend is the in-class definition.
8327 But, if `f' was called before this point, the
8328 instantiation of `f' will have DECL_TI_ARGS corresponding
8329 to `T' but not to `U', references to which might appear
8330 in the definition of `f'. Previously, the most general
8331 template for an instantiation of `f' was the out-of-class
8332 version; now it is the in-class version. Therefore, we
8333 run through all specialization of `f', adding to their
8334 DECL_TI_ARGS appropriately. In particular, they need a
8335 new set of outer arguments, corresponding to the
8336 arguments for this class instantiation.
8338 The same situation can arise with something like this:
8341 template <class T> class C {
8345 when `C<int>' is instantiated. Now, `f(int)' is defined
8348 if (!new_friend_is_defn)
8349 /* On the other hand, if the in-class declaration does
8350 *not* provide a definition, then we don't want to alter
8351 existing definitions. We can just leave everything
8356 tree new_template = TI_TEMPLATE (new_friend_template_info);
8357 tree new_args = TI_ARGS (new_friend_template_info);
8359 /* Overwrite whatever template info was there before, if
8360 any, with the new template information pertaining to
8362 DECL_TEMPLATE_INFO (old_decl) = new_friend_template_info;
8364 if (TREE_CODE (old_decl) != TEMPLATE_DECL)
8366 /* We should have called reregister_specialization in
8368 gcc_assert (retrieve_specialization (new_template,
8372 /* Instantiate it if the global has already been used. */
8373 if (DECL_ODR_USED (old_decl))
8374 instantiate_decl (old_decl, /*defer_ok=*/true,
8375 /*expl_inst_class_mem_p=*/false);
8381 /* Indicate that the old function template is a partial
8383 DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (old_decl))
8384 = new_friend_result_template_info;
8386 gcc_assert (new_template
8387 == most_general_template (new_template));
8388 gcc_assert (new_template != old_decl);
8390 /* Reassign any specializations already in the hash table
8391 to the new more general template, and add the
8392 additional template args. */
8393 for (t = DECL_TEMPLATE_INSTANTIATIONS (old_decl);
8397 tree spec = TREE_VALUE (t);
8400 elt.tmpl = old_decl;
8401 elt.args = DECL_TI_ARGS (spec);
8402 elt.spec = NULL_TREE;
8404 htab_remove_elt (decl_specializations, &elt);
8407 = add_outermost_template_args (new_args,
8408 DECL_TI_ARGS (spec));
8410 register_specialization
8411 (spec, new_template, DECL_TI_ARGS (spec), true, 0);
8414 DECL_TEMPLATE_INSTANTIATIONS (old_decl) = NULL_TREE;
8418 /* The information from NEW_FRIEND has been merged into OLD_DECL
8419 by duplicate_decls. */
8420 new_friend = old_decl;
8425 tree context = DECL_CONTEXT (new_friend);
8429 template <class T> class C {
8430 template <class U> friend void C1<U>::f (); // case 1
8431 friend void C2<T>::f (); // case 2
8433 we only need to make sure CONTEXT is a complete type for
8434 case 2. To distinguish between the two cases, we note that
8435 CONTEXT of case 1 remains dependent type after tsubst while
8436 this isn't true for case 2. */
8437 ++processing_template_decl;
8438 dependent_p = dependent_type_p (context);
8439 --processing_template_decl;
8442 && !complete_type_or_else (context, NULL_TREE))
8443 return error_mark_node;
8445 if (COMPLETE_TYPE_P (context))
8447 /* Check to see that the declaration is really present, and,
8448 possibly obtain an improved declaration. */
8449 tree fn = check_classfn (context,
8450 new_friend, NULL_TREE);
8460 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
8461 template arguments, as for tsubst.
8463 Returns an appropriate tsubst'd friend type or error_mark_node on
8467 tsubst_friend_class (tree friend_tmpl, tree args)
8473 context = CP_DECL_CONTEXT (friend_tmpl);
8475 if (context != global_namespace)
8477 if (TREE_CODE (context) == NAMESPACE_DECL)
8478 push_nested_namespace (context);
8480 push_nested_class (tsubst (context, args, tf_none, NULL_TREE));
8483 /* Look for a class template declaration. We look for hidden names
8484 because two friend declarations of the same template are the
8485 same. For example, in:
8488 template <typename> friend class F;
8490 template <typename> struct B {
8491 template <typename> friend class F;
8494 both F templates are the same. */
8495 tmpl = lookup_name_real (DECL_NAME (friend_tmpl), 0, 0,
8496 /*block_p=*/true, 0,
8497 LOOKUP_COMPLAIN | LOOKUP_HIDDEN);
8499 /* But, if we don't find one, it might be because we're in a
8500 situation like this:
8508 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
8509 for `S<int>', not the TEMPLATE_DECL. */
8510 if (!tmpl || !DECL_CLASS_TEMPLATE_P (tmpl))
8512 tmpl = lookup_name_prefer_type (DECL_NAME (friend_tmpl), 1);
8513 tmpl = maybe_get_template_decl_from_type_decl (tmpl);
8516 if (tmpl && DECL_CLASS_TEMPLATE_P (tmpl))
8518 /* The friend template has already been declared. Just
8519 check to see that the declarations match, and install any new
8520 default parameters. We must tsubst the default parameters,
8521 of course. We only need the innermost template parameters
8522 because that is all that redeclare_class_template will look
8524 if (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (friend_tmpl))
8525 > TMPL_ARGS_DEPTH (args))
8528 location_t saved_input_location;
8529 parms = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_tmpl),
8530 args, tf_warning_or_error);
8532 saved_input_location = input_location;
8533 input_location = DECL_SOURCE_LOCATION (friend_tmpl);
8534 redeclare_class_template (TREE_TYPE (tmpl), parms);
8535 input_location = saved_input_location;
8539 friend_type = TREE_TYPE (tmpl);
8543 /* The friend template has not already been declared. In this
8544 case, the instantiation of the template class will cause the
8545 injection of this template into the global scope. */
8546 tmpl = tsubst (friend_tmpl, args, tf_warning_or_error, NULL_TREE);
8547 if (tmpl == error_mark_node)
8548 return error_mark_node;
8550 /* The new TMPL is not an instantiation of anything, so we
8551 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
8552 the new type because that is supposed to be the corresponding
8553 template decl, i.e., TMPL. */
8554 DECL_USE_TEMPLATE (tmpl) = 0;
8555 DECL_TEMPLATE_INFO (tmpl) = NULL_TREE;
8556 CLASSTYPE_USE_TEMPLATE (TREE_TYPE (tmpl)) = 0;
8557 CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl))
8558 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl)));
8560 /* Inject this template into the global scope. */
8561 friend_type = TREE_TYPE (pushdecl_top_level_maybe_friend (tmpl, true));
8564 if (context != global_namespace)
8566 if (TREE_CODE (context) == NAMESPACE_DECL)
8567 pop_nested_namespace (context);
8569 pop_nested_class ();
8575 /* Returns zero if TYPE cannot be completed later due to circularity.
8576 Otherwise returns one. */
8579 can_complete_type_without_circularity (tree type)
8581 if (type == NULL_TREE || type == error_mark_node)
8583 else if (COMPLETE_TYPE_P (type))
8585 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
8586 return can_complete_type_without_circularity (TREE_TYPE (type));
8587 else if (CLASS_TYPE_P (type)
8588 && TYPE_BEING_DEFINED (TYPE_MAIN_VARIANT (type)))
8594 /* Apply any attributes which had to be deferred until instantiation
8595 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
8596 ARGS, COMPLAIN, IN_DECL are as tsubst. */
8599 apply_late_template_attributes (tree *decl_p, tree attributes, int attr_flags,
8600 tree args, tsubst_flags_t complain, tree in_decl)
8602 tree last_dep = NULL_TREE;
8606 for (t = attributes; t; t = TREE_CHAIN (t))
8607 if (ATTR_IS_DEPENDENT (t))
8610 attributes = copy_list (attributes);
8614 if (DECL_P (*decl_p))
8616 if (TREE_TYPE (*decl_p) == error_mark_node)
8618 p = &DECL_ATTRIBUTES (*decl_p);
8621 p = &TYPE_ATTRIBUTES (*decl_p);
8625 tree late_attrs = NULL_TREE;
8626 tree *q = &late_attrs;
8628 for (*p = attributes; *p; )
8631 if (ATTR_IS_DEPENDENT (t))
8633 *p = TREE_CHAIN (t);
8634 TREE_CHAIN (t) = NULL_TREE;
8635 /* If the first attribute argument is an identifier, don't
8636 pass it through tsubst. Attributes like mode, format,
8637 cleanup and several target specific attributes expect it
8640 && TREE_CODE (TREE_VALUE (t)) == TREE_LIST
8641 && TREE_VALUE (TREE_VALUE (t))
8642 && (TREE_CODE (TREE_VALUE (TREE_VALUE (t)))
8643 == IDENTIFIER_NODE))
8646 = tsubst_expr (TREE_CHAIN (TREE_VALUE (t)), args, complain,
8648 /*integral_constant_expression_p=*/false);
8649 if (chain != TREE_CHAIN (TREE_VALUE (t)))
8651 = tree_cons (NULL_TREE, TREE_VALUE (TREE_VALUE (t)),
8656 = tsubst_expr (TREE_VALUE (t), args, complain, in_decl,
8657 /*integral_constant_expression_p=*/false);
8659 q = &TREE_CHAIN (t);
8662 p = &TREE_CHAIN (t);
8665 cplus_decl_attributes (decl_p, late_attrs, attr_flags);
8669 /* Perform (or defer) access check for typedefs that were referenced
8670 from within the template TMPL code.
8671 This is a subroutine of instantiate_template and instantiate_class_template.
8672 TMPL is the template to consider and TARGS is the list of arguments of
8676 perform_typedefs_access_check (tree tmpl, tree targs)
8678 location_t saved_location;
8680 qualified_typedef_usage_t *iter;
8683 || (!CLASS_TYPE_P (tmpl)
8684 && TREE_CODE (tmpl) != FUNCTION_DECL))
8687 saved_location = input_location;
8688 FOR_EACH_VEC_ELT (qualified_typedef_usage_t,
8689 get_types_needing_access_check (tmpl),
8692 tree type_decl = iter->typedef_decl;
8693 tree type_scope = iter->context;
8695 if (!type_decl || !type_scope || !CLASS_TYPE_P (type_scope))
8698 if (uses_template_parms (type_decl))
8699 type_decl = tsubst (type_decl, targs, tf_error, NULL_TREE);
8700 if (uses_template_parms (type_scope))
8701 type_scope = tsubst (type_scope, targs, tf_error, NULL_TREE);
8703 /* Make access check error messages point to the location
8704 of the use of the typedef. */
8705 input_location = iter->locus;
8706 perform_or_defer_access_check (TYPE_BINFO (type_scope),
8707 type_decl, type_decl);
8709 input_location = saved_location;
8713 instantiate_class_template_1 (tree type)
8715 tree templ, args, pattern, t, member;
8719 unsigned int saved_maximum_field_alignment;
8721 if (type == error_mark_node)
8722 return error_mark_node;
8724 if (COMPLETE_OR_OPEN_TYPE_P (type)
8725 || uses_template_parms (type))
8728 /* Figure out which template is being instantiated. */
8729 templ = most_general_template (CLASSTYPE_TI_TEMPLATE (type));
8730 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
8732 /* Determine what specialization of the original template to
8734 t = most_specialized_class (type, templ, tf_warning_or_error);
8735 if (t == error_mark_node)
8737 TYPE_BEING_DEFINED (type) = 1;
8738 return error_mark_node;
8742 /* This TYPE is actually an instantiation of a partial
8743 specialization. We replace the innermost set of ARGS with
8744 the arguments appropriate for substitution. For example,
8747 template <class T> struct S {};
8748 template <class T> struct S<T*> {};
8750 and supposing that we are instantiating S<int*>, ARGS will
8751 presently be {int*} -- but we need {int}. */
8752 pattern = TREE_TYPE (t);
8753 args = TREE_PURPOSE (t);
8757 pattern = TREE_TYPE (templ);
8758 args = CLASSTYPE_TI_ARGS (type);
8761 /* If the template we're instantiating is incomplete, then clearly
8762 there's nothing we can do. */
8763 if (!COMPLETE_TYPE_P (pattern))
8766 /* If we've recursively instantiated too many templates, stop. */
8767 if (! push_tinst_level (type))
8770 /* Now we're really doing the instantiation. Mark the type as in
8771 the process of being defined. */
8772 TYPE_BEING_DEFINED (type) = 1;
8774 /* We may be in the middle of deferred access check. Disable
8776 push_deferring_access_checks (dk_no_deferred);
8778 push_to_top_level ();
8779 /* Use #pragma pack from the template context. */
8780 saved_maximum_field_alignment = maximum_field_alignment;
8781 maximum_field_alignment = TYPE_PRECISION (pattern);
8783 SET_CLASSTYPE_INTERFACE_UNKNOWN (type);
8785 /* Set the input location to the most specialized template definition.
8786 This is needed if tsubsting causes an error. */
8787 typedecl = TYPE_MAIN_DECL (pattern);
8788 input_location = DECL_SOURCE_LOCATION (TYPE_NAME (type)) =
8789 DECL_SOURCE_LOCATION (typedecl);
8791 TYPE_PACKED (type) = TYPE_PACKED (pattern);
8792 TYPE_ALIGN (type) = TYPE_ALIGN (pattern);
8793 TYPE_USER_ALIGN (type) = TYPE_USER_ALIGN (pattern);
8794 TYPE_FOR_JAVA (type) = TYPE_FOR_JAVA (pattern); /* For libjava's JArray<T> */
8795 if (ANON_AGGR_TYPE_P (pattern))
8796 SET_ANON_AGGR_TYPE_P (type);
8797 if (CLASSTYPE_VISIBILITY_SPECIFIED (pattern))
8799 CLASSTYPE_VISIBILITY_SPECIFIED (type) = 1;
8800 CLASSTYPE_VISIBILITY (type) = CLASSTYPE_VISIBILITY (pattern);
8801 /* Adjust visibility for template arguments. */
8802 determine_visibility (TYPE_MAIN_DECL (type));
8804 CLASSTYPE_FINAL (type) = CLASSTYPE_FINAL (pattern);
8806 pbinfo = TYPE_BINFO (pattern);
8808 /* We should never instantiate a nested class before its enclosing
8809 class; we need to look up the nested class by name before we can
8810 instantiate it, and that lookup should instantiate the enclosing
8812 gcc_assert (!DECL_CLASS_SCOPE_P (TYPE_MAIN_DECL (pattern))
8813 || COMPLETE_OR_OPEN_TYPE_P (TYPE_CONTEXT (type)));
8815 base_list = NULL_TREE;
8816 if (BINFO_N_BASE_BINFOS (pbinfo))
8822 /* We must enter the scope containing the type, as that is where
8823 the accessibility of types named in dependent bases are
8825 pushed_scope = push_scope (CP_TYPE_CONTEXT (type));
8827 /* Substitute into each of the bases to determine the actual
8829 for (i = 0; BINFO_BASE_ITERATE (pbinfo, i, pbase_binfo); i++)
8832 tree access = BINFO_BASE_ACCESS (pbinfo, i);
8833 tree expanded_bases = NULL_TREE;
8836 if (PACK_EXPANSION_P (BINFO_TYPE (pbase_binfo)))
8839 tsubst_pack_expansion (BINFO_TYPE (pbase_binfo),
8840 args, tf_error, NULL_TREE);
8841 if (expanded_bases == error_mark_node)
8844 len = TREE_VEC_LENGTH (expanded_bases);
8847 for (idx = 0; idx < len; idx++)
8850 /* Extract the already-expanded base class. */
8851 base = TREE_VEC_ELT (expanded_bases, idx);
8853 /* Substitute to figure out the base class. */
8854 base = tsubst (BINFO_TYPE (pbase_binfo), args, tf_error,
8857 if (base == error_mark_node)
8860 base_list = tree_cons (access, base, base_list);
8861 if (BINFO_VIRTUAL_P (pbase_binfo))
8862 TREE_TYPE (base_list) = integer_type_node;
8866 /* The list is now in reverse order; correct that. */
8867 base_list = nreverse (base_list);
8870 pop_scope (pushed_scope);
8872 /* Now call xref_basetypes to set up all the base-class
8874 xref_basetypes (type, base_list);
8876 apply_late_template_attributes (&type, TYPE_ATTRIBUTES (pattern),
8877 (int) ATTR_FLAG_TYPE_IN_PLACE,
8878 args, tf_error, NULL_TREE);
8879 fixup_attribute_variants (type);
8881 /* Now that our base classes are set up, enter the scope of the
8882 class, so that name lookups into base classes, etc. will work
8883 correctly. This is precisely analogous to what we do in
8884 begin_class_definition when defining an ordinary non-template
8885 class, except we also need to push the enclosing classes. */
8886 push_nested_class (type);
8888 /* Now members are processed in the order of declaration. */
8889 for (member = CLASSTYPE_DECL_LIST (pattern);
8890 member; member = TREE_CHAIN (member))
8892 tree t = TREE_VALUE (member);
8894 if (TREE_PURPOSE (member))
8898 /* Build new CLASSTYPE_NESTED_UTDS. */
8901 bool class_template_p;
8903 class_template_p = (TREE_CODE (t) != ENUMERAL_TYPE
8904 && TYPE_LANG_SPECIFIC (t)
8905 && CLASSTYPE_IS_TEMPLATE (t));
8906 /* If the member is a class template, then -- even after
8907 substitution -- there may be dependent types in the
8908 template argument list for the class. We increment
8909 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
8910 that function will assume that no types are dependent
8911 when outside of a template. */
8912 if (class_template_p)
8913 ++processing_template_decl;
8914 newtag = tsubst (t, args, tf_error, NULL_TREE);
8915 if (class_template_p)
8916 --processing_template_decl;
8917 if (newtag == error_mark_node)
8920 if (TREE_CODE (newtag) != ENUMERAL_TYPE)
8922 tree name = TYPE_IDENTIFIER (t);
8924 if (class_template_p)
8925 /* Unfortunately, lookup_template_class sets
8926 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
8927 instantiation (i.e., for the type of a member
8928 template class nested within a template class.)
8929 This behavior is required for
8930 maybe_process_partial_specialization to work
8931 correctly, but is not accurate in this case;
8932 the TAG is not an instantiation of anything.
8933 (The corresponding TEMPLATE_DECL is an
8934 instantiation, but the TYPE is not.) */
8935 CLASSTYPE_USE_TEMPLATE (newtag) = 0;
8937 /* Now, we call pushtag to put this NEWTAG into the scope of
8938 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
8939 pushtag calling push_template_decl. We don't have to do
8940 this for enums because it will already have been done in
8943 SET_IDENTIFIER_TYPE_VALUE (name, newtag);
8944 pushtag (name, newtag, /*tag_scope=*/ts_current);
8947 else if (TREE_CODE (t) == FUNCTION_DECL
8948 || DECL_FUNCTION_TEMPLATE_P (t))
8950 /* Build new TYPE_METHODS. */
8953 if (TREE_CODE (t) == TEMPLATE_DECL)
8954 ++processing_template_decl;
8955 r = tsubst (t, args, tf_error, NULL_TREE);
8956 if (TREE_CODE (t) == TEMPLATE_DECL)
8957 --processing_template_decl;
8958 set_current_access_from_decl (r);
8959 finish_member_declaration (r);
8960 /* Instantiate members marked with attribute used. */
8961 if (r != error_mark_node && DECL_PRESERVE_P (r))
8966 /* Build new TYPE_FIELDS. */
8967 if (TREE_CODE (t) == STATIC_ASSERT)
8970 tsubst_expr (STATIC_ASSERT_CONDITION (t), args,
8971 tf_warning_or_error, NULL_TREE,
8972 /*integral_constant_expression_p=*/true);
8973 finish_static_assert (condition,
8974 STATIC_ASSERT_MESSAGE (t),
8975 STATIC_ASSERT_SOURCE_LOCATION (t),
8978 else if (TREE_CODE (t) != CONST_DECL)
8982 /* The file and line for this declaration, to
8983 assist in error message reporting. Since we
8984 called push_tinst_level above, we don't need to
8986 input_location = DECL_SOURCE_LOCATION (t);
8988 if (TREE_CODE (t) == TEMPLATE_DECL)
8989 ++processing_template_decl;
8990 r = tsubst (t, args, tf_warning_or_error, NULL_TREE);
8991 if (TREE_CODE (t) == TEMPLATE_DECL)
8992 --processing_template_decl;
8993 if (TREE_CODE (r) == VAR_DECL)
8997 [t]he initialization (and any associated
8998 side-effects) of a static data member does
8999 not occur unless the static data member is
9000 itself used in a way that requires the
9001 definition of the static data member to
9004 Therefore, we do not substitute into the
9005 initialized for the static data member here. */
9006 finish_static_data_member_decl
9009 /*init_const_expr_p=*/false,
9010 /*asmspec_tree=*/NULL_TREE,
9012 /* Instantiate members marked with attribute used. */
9013 if (r != error_mark_node && DECL_PRESERVE_P (r))
9016 else if (TREE_CODE (r) == FIELD_DECL)
9018 /* Determine whether R has a valid type and can be
9019 completed later. If R is invalid, then it is
9020 replaced by error_mark_node so that it will not be
9021 added to TYPE_FIELDS. */
9022 tree rtype = TREE_TYPE (r);
9023 if (can_complete_type_without_circularity (rtype))
9024 complete_type (rtype);
9026 if (!COMPLETE_TYPE_P (rtype))
9028 cxx_incomplete_type_error (r, rtype);
9029 r = error_mark_node;
9033 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
9034 such a thing will already have been added to the field
9035 list by tsubst_enum in finish_member_declaration in the
9036 CLASSTYPE_NESTED_UTDS case above. */
9037 if (!(TREE_CODE (r) == TYPE_DECL
9038 && TREE_CODE (TREE_TYPE (r)) == ENUMERAL_TYPE
9039 && DECL_ARTIFICIAL (r)))
9041 set_current_access_from_decl (r);
9042 finish_member_declaration (r);
9049 if (TYPE_P (t) || DECL_CLASS_TEMPLATE_P (t))
9051 /* Build new CLASSTYPE_FRIEND_CLASSES. */
9053 tree friend_type = t;
9054 bool adjust_processing_template_decl = false;
9056 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
9058 /* template <class T> friend class C; */
9059 friend_type = tsubst_friend_class (friend_type, args);
9060 adjust_processing_template_decl = true;
9062 else if (TREE_CODE (friend_type) == UNBOUND_CLASS_TEMPLATE)
9064 /* template <class T> friend class C::D; */
9065 friend_type = tsubst (friend_type, args,
9066 tf_warning_or_error, NULL_TREE);
9067 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
9068 friend_type = TREE_TYPE (friend_type);
9069 adjust_processing_template_decl = true;
9071 else if (TREE_CODE (friend_type) == TYPENAME_TYPE
9072 || TREE_CODE (friend_type) == TEMPLATE_TYPE_PARM)
9074 /* This could be either
9078 when dependent_type_p is false or
9080 template <class U> friend class T::C;
9083 friend_type = tsubst (friend_type, args,
9084 tf_warning_or_error, NULL_TREE);
9085 /* Bump processing_template_decl for correct
9086 dependent_type_p calculation. */
9087 ++processing_template_decl;
9088 if (dependent_type_p (friend_type))
9089 adjust_processing_template_decl = true;
9090 --processing_template_decl;
9092 else if (!CLASSTYPE_USE_TEMPLATE (friend_type)
9093 && hidden_name_p (TYPE_NAME (friend_type)))
9097 where C hasn't been declared yet. Let's lookup name
9098 from namespace scope directly, bypassing any name that
9099 come from dependent base class. */
9100 tree ns = decl_namespace_context (TYPE_MAIN_DECL (friend_type));
9102 /* The call to xref_tag_from_type does injection for friend
9104 push_nested_namespace (ns);
9106 xref_tag_from_type (friend_type, NULL_TREE,
9107 /*tag_scope=*/ts_current);
9108 pop_nested_namespace (ns);
9110 else if (uses_template_parms (friend_type))
9111 /* friend class C<T>; */
9112 friend_type = tsubst (friend_type, args,
9113 tf_warning_or_error, NULL_TREE);
9118 where C is already declared or
9120 friend class C<int>;
9122 We don't have to do anything in these cases. */
9124 if (adjust_processing_template_decl)
9125 /* Trick make_friend_class into realizing that the friend
9126 we're adding is a template, not an ordinary class. It's
9127 important that we use make_friend_class since it will
9128 perform some error-checking and output cross-reference
9130 ++processing_template_decl;
9132 if (friend_type != error_mark_node)
9133 make_friend_class (type, friend_type, /*complain=*/false);
9135 if (adjust_processing_template_decl)
9136 --processing_template_decl;
9140 /* Build new DECL_FRIENDLIST. */
9143 /* The file and line for this declaration, to
9144 assist in error message reporting. Since we
9145 called push_tinst_level above, we don't need to
9147 input_location = DECL_SOURCE_LOCATION (t);
9149 if (TREE_CODE (t) == TEMPLATE_DECL)
9151 ++processing_template_decl;
9152 push_deferring_access_checks (dk_no_check);
9155 r = tsubst_friend_function (t, args);
9156 add_friend (type, r, /*complain=*/false);
9157 if (TREE_CODE (t) == TEMPLATE_DECL)
9159 pop_deferring_access_checks ();
9160 --processing_template_decl;
9166 if (CLASSTYPE_LAMBDA_EXPR (type))
9168 tree decl = lambda_function (type);
9171 tree lambda = CLASSTYPE_LAMBDA_EXPR (type);
9172 if (LAMBDA_EXPR_DEDUCE_RETURN_TYPE_P (lambda))
9174 apply_lambda_return_type (lambda, void_type_node);
9175 LAMBDA_EXPR_RETURN_TYPE (lambda) = NULL_TREE;
9177 instantiate_decl (decl, false, false);
9178 maybe_add_lambda_conv_op (type);
9181 gcc_assert (errorcount);
9184 /* Set the file and line number information to whatever is given for
9185 the class itself. This puts error messages involving generated
9186 implicit functions at a predictable point, and the same point
9187 that would be used for non-template classes. */
9188 input_location = DECL_SOURCE_LOCATION (typedecl);
9190 unreverse_member_declarations (type);
9191 finish_struct_1 (type);
9192 TYPE_BEING_DEFINED (type) = 0;
9194 /* We don't instantiate default arguments for member functions. 14.7.1:
9196 The implicit instantiation of a class template specialization causes
9197 the implicit instantiation of the declarations, but not of the
9198 definitions or default arguments, of the class member functions,
9199 member classes, static data members and member templates.... */
9201 /* Some typedefs referenced from within the template code need to be access
9202 checked at template instantiation time, i.e now. These types were
9203 added to the template at parsing time. Let's get those and perform
9204 the access checks then. */
9205 perform_typedefs_access_check (pattern, args);
9206 perform_deferred_access_checks ();
9207 pop_nested_class ();
9208 maximum_field_alignment = saved_maximum_field_alignment;
9209 pop_from_top_level ();
9210 pop_deferring_access_checks ();
9213 /* The vtable for a template class can be emitted in any translation
9214 unit in which the class is instantiated. When there is no key
9215 method, however, finish_struct_1 will already have added TYPE to
9216 the keyed_classes list. */
9217 if (TYPE_CONTAINS_VPTR_P (type) && CLASSTYPE_KEY_METHOD (type))
9218 keyed_classes = tree_cons (NULL_TREE, type, keyed_classes);
9223 /* Wrapper for instantiate_class_template_1. */
9226 instantiate_class_template (tree type)
9229 timevar_push (TV_TEMPLATE_INST);
9230 ret = instantiate_class_template_1 (type);
9231 timevar_pop (TV_TEMPLATE_INST);
9236 tsubst_template_arg (tree t, tree args, tsubst_flags_t complain, tree in_decl)
9242 else if (TYPE_P (t))
9243 r = tsubst (t, args, complain, in_decl);
9246 if (!(complain & tf_warning))
9247 ++c_inhibit_evaluation_warnings;
9248 r = tsubst_expr (t, args, complain, in_decl,
9249 /*integral_constant_expression_p=*/true);
9250 if (!(complain & tf_warning))
9251 --c_inhibit_evaluation_warnings;
9252 /* Preserve the raw-reference nature of T. */
9253 if (TREE_TYPE (t) && TREE_CODE (TREE_TYPE (t)) == REFERENCE_TYPE
9254 && REFERENCE_REF_P (r))
9255 r = TREE_OPERAND (r, 0);
9260 /* Given a function parameter pack TMPL_PARM and some function parameters
9261 instantiated from it at *SPEC_P, return a NONTYPE_ARGUMENT_PACK of them
9262 and set *SPEC_P to point at the next point in the list. */
9265 extract_fnparm_pack (tree tmpl_parm, tree *spec_p)
9267 /* Collect all of the extra "packed" parameters into an
9271 tree argpack = make_node (NONTYPE_ARGUMENT_PACK);
9272 tree argtypepack = cxx_make_type (TYPE_ARGUMENT_PACK);
9273 tree spec_parm = *spec_p;
9276 for (len = 0; spec_parm; ++len, spec_parm = TREE_CHAIN (spec_parm))
9278 && !function_parameter_expanded_from_pack_p (spec_parm, tmpl_parm))
9281 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
9282 parmvec = make_tree_vec (len);
9283 parmtypevec = make_tree_vec (len);
9284 spec_parm = *spec_p;
9285 for (i = 0; i < len; i++, spec_parm = DECL_CHAIN (spec_parm))
9287 TREE_VEC_ELT (parmvec, i) = spec_parm;
9288 TREE_VEC_ELT (parmtypevec, i) = TREE_TYPE (spec_parm);
9291 /* Build the argument packs. */
9292 SET_ARGUMENT_PACK_ARGS (argpack, parmvec);
9293 SET_ARGUMENT_PACK_ARGS (argtypepack, parmtypevec);
9294 TREE_TYPE (argpack) = argtypepack;
9295 *spec_p = spec_parm;
9300 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
9301 NONTYPE_ARGUMENT_PACK. */
9304 make_fnparm_pack (tree spec_parm)
9306 return extract_fnparm_pack (NULL_TREE, &spec_parm);
9309 /* Substitute ARGS into T, which is an pack expansion
9310 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
9311 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
9312 (if only a partial substitution could be performed) or
9313 ERROR_MARK_NODE if there was an error. */
9315 tsubst_pack_expansion (tree t, tree args, tsubst_flags_t complain,
9319 tree pack, packs = NULL_TREE;
9320 bool unsubstituted_packs = false;
9321 bool real_packs = false;
9322 int missing_level = 0;
9325 htab_t saved_local_specializations = NULL;
9326 bool need_local_specializations = false;
9329 gcc_assert (PACK_EXPANSION_P (t));
9330 pattern = PACK_EXPANSION_PATTERN (t);
9332 /* Add in any args remembered from an earlier partial instantiation. */
9333 args = add_to_template_args (PACK_EXPANSION_EXTRA_ARGS (t), args);
9335 levels = TMPL_ARGS_DEPTH (args);
9337 /* Determine the argument packs that will instantiate the parameter
9338 packs used in the expansion expression. While we're at it,
9339 compute the number of arguments to be expanded and make sure it
9341 for (pack = PACK_EXPANSION_PARAMETER_PACKS (t); pack;
9342 pack = TREE_CHAIN (pack))
9344 tree parm_pack = TREE_VALUE (pack);
9345 tree arg_pack = NULL_TREE;
9346 tree orig_arg = NULL_TREE;
9349 if (TREE_CODE (parm_pack) == BASES)
9351 if (BASES_DIRECT (parm_pack))
9352 return calculate_direct_bases (tsubst_expr (BASES_TYPE (parm_pack),
9353 args, complain, in_decl, false));
9355 return calculate_bases (tsubst_expr (BASES_TYPE (parm_pack),
9356 args, complain, in_decl, false));
9358 if (TREE_CODE (parm_pack) == PARM_DECL)
9360 if (PACK_EXPANSION_LOCAL_P (t))
9361 arg_pack = retrieve_local_specialization (parm_pack);
9364 /* We can't rely on local_specializations for a parameter
9365 name used later in a function declaration (such as in a
9366 late-specified return type). Even if it exists, it might
9367 have the wrong value for a recursive call. Just make a
9368 dummy decl, since it's only used for its type. */
9369 arg_pack = tsubst_decl (parm_pack, args, complain);
9370 if (arg_pack && FUNCTION_PARAMETER_PACK_P (arg_pack))
9371 /* Partial instantiation of the parm_pack, we can't build
9372 up an argument pack yet. */
9373 arg_pack = NULL_TREE;
9375 arg_pack = make_fnparm_pack (arg_pack);
9376 need_local_specializations = true;
9382 template_parm_level_and_index (parm_pack, &level, &idx);
9384 if (level <= levels)
9385 arg_pack = TMPL_ARG (args, level, idx);
9388 orig_arg = arg_pack;
9389 if (arg_pack && TREE_CODE (arg_pack) == ARGUMENT_PACK_SELECT)
9390 arg_pack = ARGUMENT_PACK_SELECT_FROM_PACK (arg_pack);
9392 if (arg_pack && !ARGUMENT_PACK_P (arg_pack))
9393 /* This can only happen if we forget to expand an argument
9394 pack somewhere else. Just return an error, silently. */
9396 result = make_tree_vec (1);
9397 TREE_VEC_ELT (result, 0) = error_mark_node;
9401 if (arg_from_parm_pack_p (arg_pack, parm_pack))
9402 /* The argument pack that the parameter maps to is just an
9403 expansion of the parameter itself, such as one would find
9404 in the implicit typedef of a class inside the class itself.
9405 Consider this parameter "unsubstituted", so that we will
9406 maintain the outer pack expansion. */
9407 arg_pack = NULL_TREE;
9412 TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack));
9414 /* Don't bother trying to do a partial substitution with
9415 incomplete packs; we'll try again after deduction. */
9416 if (ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
9421 else if (len != my_len)
9423 if (!(complain & tf_error))
9424 /* Fail quietly. */;
9425 else if (TREE_CODE (t) == TYPE_PACK_EXPANSION)
9426 error ("mismatched argument pack lengths while expanding "
9430 error ("mismatched argument pack lengths while expanding "
9433 return error_mark_node;
9436 if (TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack)) == 1
9437 && PACK_EXPANSION_P (TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack),
9439 /* This isn't a real argument pack yet. */;
9443 /* Keep track of the parameter packs and their corresponding
9445 packs = tree_cons (parm_pack, arg_pack, packs);
9446 TREE_TYPE (packs) = orig_arg;
9450 /* We can't substitute for this parameter pack. We use a flag as
9451 well as the missing_level counter because function parameter
9452 packs don't have a level. */
9453 unsubstituted_packs = true;
9454 if (!missing_level || missing_level > level)
9455 missing_level = level;
9459 /* We cannot expand this expansion expression, because we don't have
9460 all of the argument packs we need. */
9461 if (unsubstituted_packs)
9465 /* We got some full packs, but we can't substitute them in until we
9466 have values for all the packs. So remember these until then. */
9469 t = make_pack_expansion (pattern);
9471 /* The call to add_to_template_args above assumes no overlap
9472 between saved args and new args, so prune away any fake
9473 args, i.e. those that satisfied arg_from_parm_pack_p above. */
9474 if (missing_level && levels >= missing_level)
9476 gcc_assert (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args)
9477 && missing_level > 1);
9478 TREE_VEC_LENGTH (args) = missing_level - 1;
9479 save_args = copy_node (args);
9480 TREE_VEC_LENGTH (args) = levels;
9485 PACK_EXPANSION_EXTRA_ARGS (t) = save_args;
9489 /* There were no real arguments, we're just replacing a parameter
9490 pack with another version of itself. Substitute into the
9491 pattern and return a PACK_EXPANSION_*. The caller will need to
9493 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
9494 t = tsubst_expr (pattern, args, complain, in_decl,
9495 /*integral_constant_expression_p=*/false);
9497 t = tsubst (pattern, args, complain, in_decl);
9498 t = make_pack_expansion (t);
9503 /* We could not find any argument packs that work. */
9505 return error_mark_node;
9507 if (need_local_specializations)
9509 /* We're in a late-specified return type, so create our own local
9510 specializations table; the current table is either NULL or (in the
9511 case of recursive unification) might have bindings that we don't
9512 want to use or alter. */
9513 saved_local_specializations = local_specializations;
9514 local_specializations = htab_create (37,
9515 hash_local_specialization,
9516 eq_local_specializations,
9520 /* For each argument in each argument pack, substitute into the
9522 result = make_tree_vec (len);
9523 for (i = 0; i < len; ++i)
9525 /* For parameter pack, change the substitution of the parameter
9526 pack to the ith argument in its argument pack, then expand
9528 for (pack = packs; pack; pack = TREE_CHAIN (pack))
9530 tree parm = TREE_PURPOSE (pack);
9533 /* Select the Ith argument from the pack. */
9534 if (TREE_CODE (parm) == PARM_DECL)
9538 arg = make_node (ARGUMENT_PACK_SELECT);
9539 ARGUMENT_PACK_SELECT_FROM_PACK (arg) = TREE_VALUE (pack);
9541 register_local_specialization (arg, parm);
9544 arg = retrieve_local_specialization (parm);
9549 template_parm_level_and_index (parm, &level, &idx);
9553 arg = make_node (ARGUMENT_PACK_SELECT);
9554 ARGUMENT_PACK_SELECT_FROM_PACK (arg) = TREE_VALUE (pack);
9555 /* Update the corresponding argument. */
9556 TMPL_ARG (args, level, idx) = arg;
9559 /* Re-use the ARGUMENT_PACK_SELECT. */
9560 arg = TMPL_ARG (args, level, idx);
9562 ARGUMENT_PACK_SELECT_INDEX (arg) = i;
9565 /* Substitute into the PATTERN with the altered arguments. */
9566 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
9567 TREE_VEC_ELT (result, i) =
9568 tsubst_expr (pattern, args, complain, in_decl,
9569 /*integral_constant_expression_p=*/false);
9571 TREE_VEC_ELT (result, i) = tsubst (pattern, args, complain, in_decl);
9573 if (TREE_VEC_ELT (result, i) == error_mark_node)
9575 result = error_mark_node;
9580 /* Update ARGS to restore the substitution from parameter packs to
9581 their argument packs. */
9582 for (pack = packs; pack; pack = TREE_CHAIN (pack))
9584 tree parm = TREE_PURPOSE (pack);
9586 if (TREE_CODE (parm) == PARM_DECL)
9587 register_local_specialization (TREE_TYPE (pack), parm);
9591 template_parm_level_and_index (parm, &level, &idx);
9593 /* Update the corresponding argument. */
9594 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
9595 TREE_VEC_ELT (TREE_VEC_ELT (args, level -1 ), idx) =
9598 TREE_VEC_ELT (args, idx) = TREE_TYPE (pack);
9602 if (need_local_specializations)
9604 htab_delete (local_specializations);
9605 local_specializations = saved_local_specializations;
9611 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
9612 TMPL. We do this using DECL_PARM_INDEX, which should work even with
9613 parameter packs; all parms generated from a function parameter pack will
9614 have the same DECL_PARM_INDEX. */
9617 get_pattern_parm (tree parm, tree tmpl)
9619 tree pattern = DECL_TEMPLATE_RESULT (tmpl);
9622 if (DECL_ARTIFICIAL (parm))
9624 for (patparm = DECL_ARGUMENTS (pattern);
9625 patparm; patparm = DECL_CHAIN (patparm))
9626 if (DECL_ARTIFICIAL (patparm)
9627 && DECL_NAME (parm) == DECL_NAME (patparm))
9632 patparm = FUNCTION_FIRST_USER_PARM (DECL_TEMPLATE_RESULT (tmpl));
9633 patparm = chain_index (DECL_PARM_INDEX (parm)-1, patparm);
9634 gcc_assert (DECL_PARM_INDEX (patparm)
9635 == DECL_PARM_INDEX (parm));
9641 /* Substitute ARGS into the vector or list of template arguments T. */
9644 tsubst_template_args (tree t, tree args, tsubst_flags_t complain, tree in_decl)
9647 int len, need_new = 0, i, expanded_len_adjust = 0, out;
9650 if (t == error_mark_node)
9651 return error_mark_node;
9653 len = TREE_VEC_LENGTH (t);
9654 elts = XALLOCAVEC (tree, len);
9656 for (i = 0; i < len; i++)
9658 tree orig_arg = TREE_VEC_ELT (t, i);
9661 if (TREE_CODE (orig_arg) == TREE_VEC)
9662 new_arg = tsubst_template_args (orig_arg, args, complain, in_decl);
9663 else if (PACK_EXPANSION_P (orig_arg))
9665 /* Substitute into an expansion expression. */
9666 new_arg = tsubst_pack_expansion (orig_arg, args, complain, in_decl);
9668 if (TREE_CODE (new_arg) == TREE_VEC)
9669 /* Add to the expanded length adjustment the number of
9670 expanded arguments. We subtract one from this
9671 measurement, because the argument pack expression
9672 itself is already counted as 1 in
9673 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
9674 the argument pack is empty. */
9675 expanded_len_adjust += TREE_VEC_LENGTH (new_arg) - 1;
9677 else if (ARGUMENT_PACK_P (orig_arg))
9679 /* Substitute into each of the arguments. */
9680 new_arg = TYPE_P (orig_arg)
9681 ? cxx_make_type (TREE_CODE (orig_arg))
9682 : make_node (TREE_CODE (orig_arg));
9684 SET_ARGUMENT_PACK_ARGS (
9686 tsubst_template_args (ARGUMENT_PACK_ARGS (orig_arg),
9687 args, complain, in_decl));
9689 if (ARGUMENT_PACK_ARGS (new_arg) == error_mark_node)
9690 new_arg = error_mark_node;
9692 if (TREE_CODE (new_arg) == NONTYPE_ARGUMENT_PACK) {
9693 TREE_TYPE (new_arg) = tsubst (TREE_TYPE (orig_arg), args,
9695 TREE_CONSTANT (new_arg) = TREE_CONSTANT (orig_arg);
9697 if (TREE_TYPE (new_arg) == error_mark_node)
9698 new_arg = error_mark_node;
9702 new_arg = tsubst_template_arg (orig_arg, args, complain, in_decl);
9704 if (new_arg == error_mark_node)
9705 return error_mark_node;
9708 if (new_arg != orig_arg)
9715 /* Make space for the expanded arguments coming from template
9717 t = make_tree_vec (len + expanded_len_adjust);
9718 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
9719 arguments for a member template.
9720 In that case each TREE_VEC in ORIG_T represents a level of template
9721 arguments, and ORIG_T won't carry any non defaulted argument count.
9722 It will rather be the nested TREE_VECs that will carry one.
9723 In other words, ORIG_T carries a non defaulted argument count only
9724 if it doesn't contain any nested TREE_VEC. */
9725 if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t))
9727 int count = GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t);
9728 count += expanded_len_adjust;
9729 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (t, count);
9731 for (i = 0, out = 0; i < len; i++)
9733 if ((PACK_EXPANSION_P (TREE_VEC_ELT (orig_t, i))
9734 || ARGUMENT_PACK_P (TREE_VEC_ELT (orig_t, i)))
9735 && TREE_CODE (elts[i]) == TREE_VEC)
9739 /* Now expand the template argument pack "in place". */
9740 for (idx = 0; idx < TREE_VEC_LENGTH (elts[i]); idx++, out++)
9741 TREE_VEC_ELT (t, out) = TREE_VEC_ELT (elts[i], idx);
9745 TREE_VEC_ELT (t, out) = elts[i];
9753 /* Return the result of substituting ARGS into the template parameters
9754 given by PARMS. If there are m levels of ARGS and m + n levels of
9755 PARMS, then the result will contain n levels of PARMS. For
9756 example, if PARMS is `template <class T> template <class U>
9757 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
9758 result will be `template <int*, double, class V>'. */
9761 tsubst_template_parms (tree parms, tree args, tsubst_flags_t complain)
9766 /* When substituting into a template, we must set
9767 PROCESSING_TEMPLATE_DECL as the template parameters may be
9768 dependent if they are based on one-another, and the dependency
9769 predicates are short-circuit outside of templates. */
9770 ++processing_template_decl;
9772 for (new_parms = &r;
9773 TMPL_PARMS_DEPTH (parms) > TMPL_ARGS_DEPTH (args);
9774 new_parms = &(TREE_CHAIN (*new_parms)),
9775 parms = TREE_CHAIN (parms))
9778 make_tree_vec (TREE_VEC_LENGTH (TREE_VALUE (parms)));
9781 for (i = 0; i < TREE_VEC_LENGTH (new_vec); ++i)
9785 if (parms == error_mark_node)
9788 tuple = TREE_VEC_ELT (TREE_VALUE (parms), i);
9790 if (tuple == error_mark_node)
9793 TREE_VEC_ELT (new_vec, i) =
9794 tsubst_template_parm (tuple, args, complain);
9798 tree_cons (size_int (TMPL_PARMS_DEPTH (parms)
9799 - TMPL_ARGS_DEPTH (args)),
9800 new_vec, NULL_TREE);
9803 --processing_template_decl;
9808 /* Return the result of substituting ARGS into one template parameter
9809 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
9810 parameter and which TREE_PURPOSE is the default argument of the
9811 template parameter. */
9814 tsubst_template_parm (tree t, tree args, tsubst_flags_t complain)
9816 tree default_value, parm_decl;
9818 if (args == NULL_TREE
9820 || t == error_mark_node)
9823 gcc_assert (TREE_CODE (t) == TREE_LIST);
9825 default_value = TREE_PURPOSE (t);
9826 parm_decl = TREE_VALUE (t);
9828 parm_decl = tsubst (parm_decl, args, complain, NULL_TREE);
9829 if (TREE_CODE (parm_decl) == PARM_DECL
9830 && invalid_nontype_parm_type_p (TREE_TYPE (parm_decl), complain))
9831 parm_decl = error_mark_node;
9832 default_value = tsubst_template_arg (default_value, args,
9833 complain, NULL_TREE);
9835 return build_tree_list (default_value, parm_decl);
9838 /* Substitute the ARGS into the indicated aggregate (or enumeration)
9839 type T. If T is not an aggregate or enumeration type, it is
9840 handled as if by tsubst. IN_DECL is as for tsubst. If
9841 ENTERING_SCOPE is nonzero, T is the context for a template which
9842 we are presently tsubst'ing. Return the substituted value. */
9845 tsubst_aggr_type (tree t,
9847 tsubst_flags_t complain,
9854 switch (TREE_CODE (t))
9857 if (TYPE_PTRMEMFUNC_P (t))
9858 return tsubst (TYPE_PTRMEMFUNC_FN_TYPE (t), args, complain, in_decl);
9860 /* Else fall through. */
9863 if (TYPE_TEMPLATE_INFO (t) && uses_template_parms (t))
9868 int saved_unevaluated_operand;
9869 int saved_inhibit_evaluation_warnings;
9871 /* In "sizeof(X<I>)" we need to evaluate "I". */
9872 saved_unevaluated_operand = cp_unevaluated_operand;
9873 cp_unevaluated_operand = 0;
9874 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
9875 c_inhibit_evaluation_warnings = 0;
9877 /* First, determine the context for the type we are looking
9879 context = TYPE_CONTEXT (t);
9880 if (context && TYPE_P (context))
9882 context = tsubst_aggr_type (context, args, complain,
9883 in_decl, /*entering_scope=*/1);
9884 /* If context is a nested class inside a class template,
9885 it may still need to be instantiated (c++/33959). */
9886 context = complete_type (context);
9889 /* Then, figure out what arguments are appropriate for the
9890 type we are trying to find. For example, given:
9892 template <class T> struct S;
9893 template <class T, class U> void f(T, U) { S<U> su; }
9895 and supposing that we are instantiating f<int, double>,
9896 then our ARGS will be {int, double}, but, when looking up
9897 S we only want {double}. */
9898 argvec = tsubst_template_args (TYPE_TI_ARGS (t), args,
9900 if (argvec == error_mark_node)
9901 r = error_mark_node;
9904 r = lookup_template_class (t, argvec, in_decl, context,
9905 entering_scope, complain);
9906 r = cp_build_qualified_type_real (r, cp_type_quals (t), complain);
9909 cp_unevaluated_operand = saved_unevaluated_operand;
9910 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
9915 /* This is not a template type, so there's nothing to do. */
9919 return tsubst (t, args, complain, in_decl);
9923 /* Substitute into the default argument ARG (a default argument for
9924 FN), which has the indicated TYPE. */
9927 tsubst_default_argument (tree fn, tree type, tree arg)
9929 tree saved_class_ptr = NULL_TREE;
9930 tree saved_class_ref = NULL_TREE;
9932 /* This can happen in invalid code. */
9933 if (TREE_CODE (arg) == DEFAULT_ARG)
9936 /* This default argument came from a template. Instantiate the
9937 default argument here, not in tsubst. In the case of
9946 we must be careful to do name lookup in the scope of S<T>,
9947 rather than in the current class. */
9948 push_access_scope (fn);
9949 /* The "this" pointer is not valid in a default argument. */
9952 saved_class_ptr = current_class_ptr;
9953 cp_function_chain->x_current_class_ptr = NULL_TREE;
9954 saved_class_ref = current_class_ref;
9955 cp_function_chain->x_current_class_ref = NULL_TREE;
9958 push_deferring_access_checks(dk_no_deferred);
9959 /* The default argument expression may cause implicitly defined
9960 member functions to be synthesized, which will result in garbage
9961 collection. We must treat this situation as if we were within
9962 the body of function so as to avoid collecting live data on the
9965 arg = tsubst_expr (arg, DECL_TI_ARGS (fn),
9966 tf_warning_or_error, NULL_TREE,
9967 /*integral_constant_expression_p=*/false);
9969 pop_deferring_access_checks();
9971 /* Restore the "this" pointer. */
9974 cp_function_chain->x_current_class_ptr = saved_class_ptr;
9975 cp_function_chain->x_current_class_ref = saved_class_ref;
9978 /* Make sure the default argument is reasonable. */
9979 arg = check_default_argument (type, arg);
9981 pop_access_scope (fn);
9986 /* Substitute into all the default arguments for FN. */
9989 tsubst_default_arguments (tree fn)
9994 tmpl_args = DECL_TI_ARGS (fn);
9996 /* If this function is not yet instantiated, we certainly don't need
9997 its default arguments. */
9998 if (uses_template_parms (tmpl_args))
10000 /* Don't do this again for clones. */
10001 if (DECL_CLONED_FUNCTION_P (fn))
10004 for (arg = TYPE_ARG_TYPES (TREE_TYPE (fn));
10006 arg = TREE_CHAIN (arg))
10007 if (TREE_PURPOSE (arg))
10008 TREE_PURPOSE (arg) = tsubst_default_argument (fn,
10010 TREE_PURPOSE (arg));
10013 /* Substitute the ARGS into the T, which is a _DECL. Return the
10014 result of the substitution. Issue error and warning messages under
10015 control of COMPLAIN. */
10018 tsubst_decl (tree t, tree args, tsubst_flags_t complain)
10020 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
10021 location_t saved_loc;
10022 tree r = NULL_TREE;
10024 hashval_t hash = 0;
10026 /* Set the filename and linenumber to improve error-reporting. */
10027 saved_loc = input_location;
10028 input_location = DECL_SOURCE_LOCATION (t);
10030 switch (TREE_CODE (t))
10032 case TEMPLATE_DECL:
10034 /* We can get here when processing a member function template,
10035 member class template, or template template parameter. */
10036 tree decl = DECL_TEMPLATE_RESULT (t);
10041 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
10043 /* Template template parameter is treated here. */
10044 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10045 if (new_type == error_mark_node)
10046 RETURN (error_mark_node);
10049 DECL_CHAIN (r) = NULL_TREE;
10050 TREE_TYPE (r) = new_type;
10051 DECL_TEMPLATE_RESULT (r)
10052 = build_decl (DECL_SOURCE_LOCATION (decl),
10053 TYPE_DECL, DECL_NAME (decl), new_type);
10054 DECL_TEMPLATE_PARMS (r)
10055 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
10057 TYPE_NAME (new_type) = r;
10061 /* We might already have an instance of this template.
10062 The ARGS are for the surrounding class type, so the
10063 full args contain the tsubst'd args for the context,
10064 plus the innermost args from the template decl. */
10065 tmpl_args = DECL_CLASS_TEMPLATE_P (t)
10066 ? CLASSTYPE_TI_ARGS (TREE_TYPE (t))
10067 : DECL_TI_ARGS (DECL_TEMPLATE_RESULT (t));
10068 /* Because this is a template, the arguments will still be
10069 dependent, even after substitution. If
10070 PROCESSING_TEMPLATE_DECL is not set, the dependency
10071 predicates will short-circuit. */
10072 ++processing_template_decl;
10073 full_args = tsubst_template_args (tmpl_args, args,
10074 complain, in_decl);
10075 --processing_template_decl;
10076 if (full_args == error_mark_node)
10077 RETURN (error_mark_node);
10079 /* If this is a default template template argument,
10080 tsubst might not have changed anything. */
10081 if (full_args == tmpl_args)
10084 hash = hash_tmpl_and_args (t, full_args);
10085 spec = retrieve_specialization (t, full_args, hash);
10086 if (spec != NULL_TREE)
10092 /* Make a new template decl. It will be similar to the
10093 original, but will record the current template arguments.
10094 We also create a new function declaration, which is just
10095 like the old one, but points to this new template, rather
10096 than the old one. */
10098 gcc_assert (DECL_LANG_SPECIFIC (r) != 0);
10099 DECL_CHAIN (r) = NULL_TREE;
10101 DECL_TEMPLATE_INFO (r) = build_template_info (t, args);
10103 if (TREE_CODE (decl) == TYPE_DECL
10104 && !TYPE_DECL_ALIAS_P (decl))
10107 ++processing_template_decl;
10108 new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10109 --processing_template_decl;
10110 if (new_type == error_mark_node)
10111 RETURN (error_mark_node);
10113 TREE_TYPE (r) = new_type;
10114 CLASSTYPE_TI_TEMPLATE (new_type) = r;
10115 DECL_TEMPLATE_RESULT (r) = TYPE_MAIN_DECL (new_type);
10116 DECL_TI_ARGS (r) = CLASSTYPE_TI_ARGS (new_type);
10117 DECL_CONTEXT (r) = TYPE_CONTEXT (new_type);
10122 ++processing_template_decl;
10123 new_decl = tsubst (decl, args, complain, in_decl);
10124 --processing_template_decl;
10125 if (new_decl == error_mark_node)
10126 RETURN (error_mark_node);
10128 DECL_TEMPLATE_RESULT (r) = new_decl;
10129 DECL_TI_TEMPLATE (new_decl) = r;
10130 TREE_TYPE (r) = TREE_TYPE (new_decl);
10131 DECL_TI_ARGS (r) = DECL_TI_ARGS (new_decl);
10132 DECL_CONTEXT (r) = DECL_CONTEXT (new_decl);
10135 SET_DECL_IMPLICIT_INSTANTIATION (r);
10136 DECL_TEMPLATE_INSTANTIATIONS (r) = NULL_TREE;
10137 DECL_TEMPLATE_SPECIALIZATIONS (r) = NULL_TREE;
10139 /* The template parameters for this new template are all the
10140 template parameters for the old template, except the
10141 outermost level of parameters. */
10142 DECL_TEMPLATE_PARMS (r)
10143 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
10146 if (PRIMARY_TEMPLATE_P (t))
10147 DECL_PRIMARY_TEMPLATE (r) = r;
10149 if (TREE_CODE (decl) != TYPE_DECL)
10150 /* Record this non-type partial instantiation. */
10151 register_specialization (r, t,
10152 DECL_TI_ARGS (DECL_TEMPLATE_RESULT (r)),
10157 case FUNCTION_DECL:
10160 tree argvec = NULL_TREE;
10168 /* Nobody should be tsubst'ing into non-template functions. */
10169 gcc_assert (DECL_TEMPLATE_INFO (t) != NULL_TREE);
10171 if (TREE_CODE (DECL_TI_TEMPLATE (t)) == TEMPLATE_DECL)
10176 /* If T is not dependent, just return it. We have to
10177 increment PROCESSING_TEMPLATE_DECL because
10178 value_dependent_expression_p assumes that nothing is
10179 dependent when PROCESSING_TEMPLATE_DECL is zero. */
10180 ++processing_template_decl;
10181 dependent_p = value_dependent_expression_p (t);
10182 --processing_template_decl;
10186 /* Calculate the most general template of which R is a
10187 specialization, and the complete set of arguments used to
10189 gen_tmpl = most_general_template (DECL_TI_TEMPLATE (t));
10190 argvec = tsubst_template_args (DECL_TI_ARGS
10191 (DECL_TEMPLATE_RESULT
10192 (DECL_TI_TEMPLATE (t))),
10193 args, complain, in_decl);
10194 if (argvec == error_mark_node)
10195 RETURN (error_mark_node);
10197 /* Check to see if we already have this specialization. */
10198 hash = hash_tmpl_and_args (gen_tmpl, argvec);
10199 spec = retrieve_specialization (gen_tmpl, argvec, hash);
10207 /* We can see more levels of arguments than parameters if
10208 there was a specialization of a member template, like
10211 template <class T> struct S { template <class U> void f(); }
10212 template <> template <class U> void S<int>::f(U);
10214 Here, we'll be substituting into the specialization,
10215 because that's where we can find the code we actually
10216 want to generate, but we'll have enough arguments for
10217 the most general template.
10219 We also deal with the peculiar case:
10221 template <class T> struct S {
10222 template <class U> friend void f();
10224 template <class U> void f() {}
10226 template void f<double>();
10228 Here, the ARGS for the instantiation of will be {int,
10229 double}. But, we only need as many ARGS as there are
10230 levels of template parameters in CODE_PATTERN. We are
10231 careful not to get fooled into reducing the ARGS in
10234 template <class T> struct S { template <class U> void f(U); }
10235 template <class T> template <> void S<T>::f(int) {}
10237 which we can spot because the pattern will be a
10238 specialization in this case. */
10239 args_depth = TMPL_ARGS_DEPTH (args);
10241 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (t)));
10242 if (args_depth > parms_depth
10243 && !DECL_TEMPLATE_SPECIALIZATION (t))
10244 args = get_innermost_template_args (args, parms_depth);
10248 /* This special case arises when we have something like this:
10250 template <class T> struct S {
10251 friend void f<int>(int, double);
10254 Here, the DECL_TI_TEMPLATE for the friend declaration
10255 will be an IDENTIFIER_NODE. We are being called from
10256 tsubst_friend_function, and we want only to create a
10257 new decl (R) with appropriate types so that we can call
10258 determine_specialization. */
10259 gen_tmpl = NULL_TREE;
10262 if (DECL_CLASS_SCOPE_P (t))
10264 if (DECL_NAME (t) == constructor_name (DECL_CONTEXT (t)))
10268 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args,
10269 complain, t, /*entering_scope=*/1);
10274 ctx = DECL_CONTEXT (t);
10276 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10277 if (type == error_mark_node)
10278 RETURN (error_mark_node);
10280 /* We do NOT check for matching decls pushed separately at this
10281 point, as they may not represent instantiations of this
10282 template, and in any case are considered separate under the
10285 DECL_USE_TEMPLATE (r) = 0;
10286 TREE_TYPE (r) = type;
10287 /* Clear out the mangled name and RTL for the instantiation. */
10288 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
10289 SET_DECL_RTL (r, NULL);
10290 /* Leave DECL_INITIAL set on deleted instantiations. */
10291 if (!DECL_DELETED_FN (r))
10292 DECL_INITIAL (r) = NULL_TREE;
10293 DECL_CONTEXT (r) = ctx;
10295 if (member && DECL_CONV_FN_P (r))
10296 /* Type-conversion operator. Reconstruct the name, in
10297 case it's the name of one of the template's parameters. */
10298 DECL_NAME (r) = mangle_conv_op_name_for_type (TREE_TYPE (type));
10300 DECL_ARGUMENTS (r) = tsubst (DECL_ARGUMENTS (t), args,
10302 DECL_RESULT (r) = NULL_TREE;
10304 TREE_STATIC (r) = 0;
10305 TREE_PUBLIC (r) = TREE_PUBLIC (t);
10306 DECL_EXTERNAL (r) = 1;
10307 /* If this is an instantiation of a function with internal
10308 linkage, we already know what object file linkage will be
10309 assigned to the instantiation. */
10310 DECL_INTERFACE_KNOWN (r) = !TREE_PUBLIC (r);
10311 DECL_DEFER_OUTPUT (r) = 0;
10312 DECL_CHAIN (r) = NULL_TREE;
10313 DECL_PENDING_INLINE_INFO (r) = 0;
10314 DECL_PENDING_INLINE_P (r) = 0;
10315 DECL_SAVED_TREE (r) = NULL_TREE;
10316 DECL_STRUCT_FUNCTION (r) = NULL;
10318 /* We'll re-clone as appropriate in instantiate_template. */
10319 DECL_CLONED_FUNCTION (r) = NULL_TREE;
10321 /* If we aren't complaining now, return on error before we register
10322 the specialization so that we'll complain eventually. */
10323 if ((complain & tf_error) == 0
10324 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
10325 && !grok_op_properties (r, /*complain=*/false))
10326 RETURN (error_mark_node);
10328 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
10329 this in the special friend case mentioned above where
10330 GEN_TMPL is NULL. */
10333 DECL_TEMPLATE_INFO (r)
10334 = build_template_info (gen_tmpl, argvec);
10335 SET_DECL_IMPLICIT_INSTANTIATION (r);
10336 register_specialization (r, gen_tmpl, argvec, false, hash);
10338 /* We're not supposed to instantiate default arguments
10339 until they are called, for a template. But, for a
10342 template <class T> void f ()
10343 { extern void g(int i = T()); }
10345 we should do the substitution when the template is
10346 instantiated. We handle the member function case in
10347 instantiate_class_template since the default arguments
10348 might refer to other members of the class. */
10350 && !PRIMARY_TEMPLATE_P (gen_tmpl)
10351 && !uses_template_parms (argvec))
10352 tsubst_default_arguments (r);
10355 DECL_TEMPLATE_INFO (r) = NULL_TREE;
10357 /* Copy the list of befriending classes. */
10358 for (friends = &DECL_BEFRIENDING_CLASSES (r);
10360 friends = &TREE_CHAIN (*friends))
10362 *friends = copy_node (*friends);
10363 TREE_VALUE (*friends) = tsubst (TREE_VALUE (*friends),
10368 if (DECL_CONSTRUCTOR_P (r) || DECL_DESTRUCTOR_P (r))
10370 maybe_retrofit_in_chrg (r);
10371 if (DECL_CONSTRUCTOR_P (r))
10372 grok_ctor_properties (ctx, r);
10373 /* If this is an instantiation of a member template, clone it.
10374 If it isn't, that'll be handled by
10375 clone_constructors_and_destructors. */
10376 if (PRIMARY_TEMPLATE_P (gen_tmpl))
10377 clone_function_decl (r, /*update_method_vec_p=*/0);
10379 else if ((complain & tf_error) != 0
10380 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
10381 && !grok_op_properties (r, /*complain=*/true))
10382 RETURN (error_mark_node);
10384 if (DECL_FRIEND_P (t) && DECL_FRIEND_CONTEXT (t))
10385 SET_DECL_FRIEND_CONTEXT (r,
10386 tsubst (DECL_FRIEND_CONTEXT (t),
10387 args, complain, in_decl));
10389 /* Possibly limit visibility based on template args. */
10390 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
10391 if (DECL_VISIBILITY_SPECIFIED (t))
10393 DECL_VISIBILITY_SPECIFIED (r) = 0;
10394 DECL_ATTRIBUTES (r)
10395 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
10397 determine_visibility (r);
10398 if (DECL_DEFAULTED_OUTSIDE_CLASS_P (r)
10399 && !processing_template_decl)
10400 defaulted_late_check (r);
10402 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
10403 args, complain, in_decl);
10409 tree type = NULL_TREE;
10411 tree expanded_types = NULL_TREE;
10412 tree prev_r = NULL_TREE;
10413 tree first_r = NULL_TREE;
10415 if (FUNCTION_PARAMETER_PACK_P (t))
10417 /* If there is a local specialization that isn't a
10418 parameter pack, it means that we're doing a "simple"
10419 substitution from inside tsubst_pack_expansion. Just
10420 return the local specialization (which will be a single
10422 tree spec = retrieve_local_specialization (t);
10424 && TREE_CODE (spec) == PARM_DECL
10425 && TREE_CODE (TREE_TYPE (spec)) != TYPE_PACK_EXPANSION)
10428 /* Expand the TYPE_PACK_EXPANSION that provides the types for
10429 the parameters in this function parameter pack. */
10430 expanded_types = tsubst_pack_expansion (TREE_TYPE (t), args,
10431 complain, in_decl);
10432 if (TREE_CODE (expanded_types) == TREE_VEC)
10434 len = TREE_VEC_LENGTH (expanded_types);
10436 /* Zero-length parameter packs are boring. Just substitute
10439 RETURN (tsubst (TREE_CHAIN (t), args, complain,
10444 /* All we did was update the type. Make a note of that. */
10445 type = expanded_types;
10446 expanded_types = NULL_TREE;
10450 /* Loop through all of the parameter's we'll build. When T is
10451 a function parameter pack, LEN is the number of expanded
10452 types in EXPANDED_TYPES; otherwise, LEN is 1. */
10454 for (i = 0; i < len; ++i)
10458 if (DECL_TEMPLATE_PARM_P (t))
10459 SET_DECL_TEMPLATE_PARM_P (r);
10461 if (expanded_types)
10462 /* We're on the Ith parameter of the function parameter
10465 /* An argument of a function parameter pack is not a parameter
10467 FUNCTION_PARAMETER_PACK_P (r) = false;
10469 /* Get the Ith type. */
10470 type = TREE_VEC_ELT (expanded_types, i);
10473 /* Rename the parameter to include the index. */
10475 make_ith_pack_parameter_name (DECL_NAME (r), i);
10478 /* We're dealing with a normal parameter. */
10479 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10481 type = type_decays_to (type);
10482 TREE_TYPE (r) = type;
10483 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
10485 if (DECL_INITIAL (r))
10487 if (TREE_CODE (DECL_INITIAL (r)) != TEMPLATE_PARM_INDEX)
10488 DECL_INITIAL (r) = TREE_TYPE (r);
10490 DECL_INITIAL (r) = tsubst (DECL_INITIAL (r), args,
10491 complain, in_decl);
10494 DECL_CONTEXT (r) = NULL_TREE;
10496 if (!DECL_TEMPLATE_PARM_P (r))
10497 DECL_ARG_TYPE (r) = type_passed_as (type);
10499 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
10500 args, complain, in_decl);
10502 /* Keep track of the first new parameter we
10503 generate. That's what will be returned to the
10508 /* Build a proper chain of parameters when substituting
10509 into a function parameter pack. */
10511 DECL_CHAIN (prev_r) = r;
10514 if (DECL_CHAIN (t))
10515 DECL_CHAIN (r) = tsubst (DECL_CHAIN (t), args,
10516 complain, DECL_CHAIN (t));
10518 /* FIRST_R contains the start of the chain we've built. */
10528 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10529 if (type == error_mark_node)
10530 RETURN (error_mark_node);
10531 TREE_TYPE (r) = type;
10532 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
10534 if (DECL_C_BIT_FIELD (r))
10535 /* For bit-fields, DECL_INITIAL gives the number of bits. For
10536 non-bit-fields DECL_INITIAL is a non-static data member
10537 initializer, which gets deferred instantiation. */
10539 = tsubst_expr (DECL_INITIAL (t), args,
10541 /*integral_constant_expression_p=*/true);
10542 else if (DECL_INITIAL (t))
10544 /* Set up DECL_TEMPLATE_INFO so that we can get at the
10545 NSDMI in perform_member_init. Still set DECL_INITIAL
10546 so that we know there is one. */
10547 DECL_INITIAL (r) = void_zero_node;
10548 gcc_assert (DECL_LANG_SPECIFIC (r) == NULL);
10549 retrofit_lang_decl (r);
10550 DECL_TEMPLATE_INFO (r) = build_template_info (t, args);
10552 /* We don't have to set DECL_CONTEXT here; it is set by
10553 finish_member_declaration. */
10554 DECL_CHAIN (r) = NULL_TREE;
10555 if (VOID_TYPE_P (type))
10556 error ("instantiation of %q+D as type %qT", r, type);
10558 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
10559 args, complain, in_decl);
10564 /* We reach here only for member using decls. */
10565 if (DECL_DEPENDENT_P (t))
10567 r = do_class_using_decl
10568 (tsubst_copy (USING_DECL_SCOPE (t), args, complain, in_decl),
10569 tsubst_copy (DECL_NAME (t), args, complain, in_decl));
10571 r = error_mark_node;
10574 TREE_PROTECTED (r) = TREE_PROTECTED (t);
10575 TREE_PRIVATE (r) = TREE_PRIVATE (t);
10581 DECL_CHAIN (r) = NULL_TREE;
10588 tree argvec = NULL_TREE;
10589 tree gen_tmpl = NULL_TREE;
10591 tree tmpl = NULL_TREE;
10593 tree type = NULL_TREE;
10596 if (TREE_CODE (t) == TYPE_DECL
10597 && t == TYPE_MAIN_DECL (TREE_TYPE (t)))
10599 /* If this is the canonical decl, we don't have to
10600 mess with instantiations, and often we can't (for
10601 typename, template type parms and such). Note that
10602 TYPE_NAME is not correct for the above test if
10603 we've copied the type for a typedef. */
10604 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10605 if (type == error_mark_node)
10606 RETURN (error_mark_node);
10607 r = TYPE_NAME (type);
10611 /* Check to see if we already have the specialization we
10614 if (DECL_CLASS_SCOPE_P (t) || DECL_NAMESPACE_SCOPE_P (t))
10616 /* T is a static data member or namespace-scope entity.
10617 We have to substitute into namespace-scope variables
10618 (even though such entities are never templates) because
10621 template <class T> void f() { extern T t; }
10623 where the entity referenced is not known until
10624 instantiation time. */
10626 ctx = DECL_CONTEXT (t);
10627 if (DECL_CLASS_SCOPE_P (t))
10629 ctx = tsubst_aggr_type (ctx, args,
10631 in_decl, /*entering_scope=*/1);
10632 /* If CTX is unchanged, then T is in fact the
10633 specialization we want. That situation occurs when
10634 referencing a static data member within in its own
10635 class. We can use pointer equality, rather than
10636 same_type_p, because DECL_CONTEXT is always
10638 if (ctx == DECL_CONTEXT (t)
10639 && (TREE_CODE (t) != TYPE_DECL
10640 /* ... unless T is a member template; in which
10641 case our caller can be willing to create a
10642 specialization of that template represented
10644 || !(DECL_TI_TEMPLATE (t)
10645 && DECL_MEMBER_TEMPLATE_P (DECL_TI_TEMPLATE (t)))))
10651 tmpl = DECL_TI_TEMPLATE (t);
10652 gen_tmpl = most_general_template (tmpl);
10653 argvec = tsubst (DECL_TI_ARGS (t), args, complain, in_decl);
10654 hash = hash_tmpl_and_args (gen_tmpl, argvec);
10655 spec = retrieve_specialization (gen_tmpl, argvec, hash);
10660 /* A local variable. */
10662 /* Subsequent calls to pushdecl will fill this in. */
10664 spec = retrieve_local_specialization (t);
10666 /* If we already have the specialization we need, there is
10667 nothing more to do. */
10674 /* Create a new node for the specialization we need. */
10676 if (type == NULL_TREE)
10678 if (is_typedef_decl (t))
10679 type = DECL_ORIGINAL_TYPE (t);
10681 type = TREE_TYPE (t);
10682 if (TREE_CODE (t) == VAR_DECL
10683 && VAR_HAD_UNKNOWN_BOUND (t)
10684 && type != error_mark_node)
10685 type = strip_array_domain (type);
10686 type = tsubst (type, args, complain, in_decl);
10688 if (TREE_CODE (r) == VAR_DECL)
10690 /* Even if the original location is out of scope, the
10691 newly substituted one is not. */
10692 DECL_DEAD_FOR_LOCAL (r) = 0;
10693 DECL_INITIALIZED_P (r) = 0;
10694 DECL_TEMPLATE_INSTANTIATED (r) = 0;
10695 if (type == error_mark_node)
10696 RETURN (error_mark_node);
10697 if (TREE_CODE (type) == FUNCTION_TYPE)
10699 /* It may seem that this case cannot occur, since:
10704 declares a function, not a variable. However:
10707 template <typename T> void g() { T t; }
10708 template void g<f>();
10710 is an attempt to declare a variable with function
10712 error ("variable %qD has function type",
10713 /* R is not yet sufficiently initialized, so we
10714 just use its name. */
10716 RETURN (error_mark_node);
10718 type = complete_type (type);
10719 /* Wait until cp_finish_decl to set this again, to handle
10720 circular dependency (template/instantiate6.C). */
10721 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r) = 0;
10722 type = check_var_type (DECL_NAME (r), type);
10724 if (DECL_HAS_VALUE_EXPR_P (t))
10726 tree ve = DECL_VALUE_EXPR (t);
10727 ve = tsubst_expr (ve, args, complain, in_decl,
10728 /*constant_expression_p=*/false);
10729 if (REFERENCE_REF_P (ve))
10731 gcc_assert (TREE_CODE (type) == REFERENCE_TYPE);
10732 ve = TREE_OPERAND (ve, 0);
10734 SET_DECL_VALUE_EXPR (r, ve);
10737 else if (DECL_SELF_REFERENCE_P (t))
10738 SET_DECL_SELF_REFERENCE_P (r);
10739 TREE_TYPE (r) = type;
10740 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
10741 DECL_CONTEXT (r) = ctx;
10742 /* Clear out the mangled name and RTL for the instantiation. */
10743 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
10744 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
10745 SET_DECL_RTL (r, NULL);
10746 /* The initializer must not be expanded until it is required;
10747 see [temp.inst]. */
10748 DECL_INITIAL (r) = NULL_TREE;
10749 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
10750 SET_DECL_RTL (r, NULL);
10751 DECL_SIZE (r) = DECL_SIZE_UNIT (r) = 0;
10752 if (TREE_CODE (r) == VAR_DECL)
10754 /* Possibly limit visibility based on template args. */
10755 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
10756 if (DECL_VISIBILITY_SPECIFIED (t))
10758 DECL_VISIBILITY_SPECIFIED (r) = 0;
10759 DECL_ATTRIBUTES (r)
10760 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
10762 determine_visibility (r);
10767 /* A static data member declaration is always marked
10768 external when it is declared in-class, even if an
10769 initializer is present. We mimic the non-template
10770 processing here. */
10771 DECL_EXTERNAL (r) = 1;
10773 register_specialization (r, gen_tmpl, argvec, false, hash);
10774 DECL_TEMPLATE_INFO (r) = build_template_info (tmpl, argvec);
10775 SET_DECL_IMPLICIT_INSTANTIATION (r);
10777 else if (cp_unevaluated_operand)
10779 /* We're substituting this var in a decltype outside of its
10780 scope, such as for a lambda return type. Don't add it to
10781 local_specializations, do perform auto deduction. */
10782 tree auto_node = type_uses_auto (type);
10786 = tsubst_expr (DECL_INITIAL (t), args, complain, in_decl,
10787 /*constant_expression_p=*/false);
10788 init = resolve_nondeduced_context (init);
10789 TREE_TYPE (r) = type
10790 = do_auto_deduction (type, init, auto_node);
10794 register_local_specialization (r, t);
10796 DECL_CHAIN (r) = NULL_TREE;
10798 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r),
10800 args, complain, in_decl);
10802 /* Preserve a typedef that names a type. */
10803 if (is_typedef_decl (r))
10805 DECL_ORIGINAL_TYPE (r) = NULL_TREE;
10806 set_underlying_type (r);
10809 layout_decl (r, 0);
10814 gcc_unreachable ();
10819 /* Restore the file and line information. */
10820 input_location = saved_loc;
10825 /* Substitute into the ARG_TYPES of a function type. */
10828 tsubst_arg_types (tree arg_types,
10830 tsubst_flags_t complain,
10833 tree remaining_arg_types;
10834 tree type = NULL_TREE;
10836 tree expanded_args = NULL_TREE;
10839 if (!arg_types || arg_types == void_list_node)
10842 remaining_arg_types = tsubst_arg_types (TREE_CHAIN (arg_types),
10843 args, complain, in_decl);
10844 if (remaining_arg_types == error_mark_node)
10845 return error_mark_node;
10847 if (PACK_EXPANSION_P (TREE_VALUE (arg_types)))
10849 /* For a pack expansion, perform substitution on the
10850 entire expression. Later on, we'll handle the arguments
10852 expanded_args = tsubst_pack_expansion (TREE_VALUE (arg_types),
10853 args, complain, in_decl);
10855 if (TREE_CODE (expanded_args) == TREE_VEC)
10856 /* So that we'll spin through the parameters, one by one. */
10857 i = TREE_VEC_LENGTH (expanded_args);
10860 /* We only partially substituted into the parameter
10861 pack. Our type is TYPE_PACK_EXPANSION. */
10862 type = expanded_args;
10863 expanded_args = NULL_TREE;
10871 type = TREE_VEC_ELT (expanded_args, i);
10873 type = tsubst (TREE_VALUE (arg_types), args, complain, in_decl);
10875 if (type == error_mark_node)
10876 return error_mark_node;
10877 if (VOID_TYPE_P (type))
10879 if (complain & tf_error)
10881 error ("invalid parameter type %qT", type);
10883 error ("in declaration %q+D", in_decl);
10885 return error_mark_node;
10888 /* Do array-to-pointer, function-to-pointer conversion, and ignore
10889 top-level qualifiers as required. */
10890 type = cv_unqualified (type_decays_to (type));
10892 /* We do not substitute into default arguments here. The standard
10893 mandates that they be instantiated only when needed, which is
10894 done in build_over_call. */
10895 default_arg = TREE_PURPOSE (arg_types);
10897 if (default_arg && TREE_CODE (default_arg) == DEFAULT_ARG)
10899 /* We've instantiated a template before its default arguments
10900 have been parsed. This can happen for a nested template
10901 class, and is not an error unless we require the default
10902 argument in a call of this function. */
10903 remaining_arg_types =
10904 tree_cons (default_arg, type, remaining_arg_types);
10905 VEC_safe_push (tree, gc, DEFARG_INSTANTIATIONS (default_arg),
10906 remaining_arg_types);
10909 remaining_arg_types =
10910 hash_tree_cons (default_arg, type, remaining_arg_types);
10913 return remaining_arg_types;
10916 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
10917 *not* handle the exception-specification for FNTYPE, because the
10918 initial substitution of explicitly provided template parameters
10919 during argument deduction forbids substitution into the
10920 exception-specification:
10924 All references in the function type of the function template to the
10925 corresponding template parameters are replaced by the specified tem-
10926 plate argument values. If a substitution in a template parameter or
10927 in the function type of the function template results in an invalid
10928 type, type deduction fails. [Note: The equivalent substitution in
10929 exception specifications is done only when the function is instanti-
10930 ated, at which point a program is ill-formed if the substitution
10931 results in an invalid type.] */
10934 tsubst_function_type (tree t,
10936 tsubst_flags_t complain,
10943 /* The TYPE_CONTEXT is not used for function/method types. */
10944 gcc_assert (TYPE_CONTEXT (t) == NULL_TREE);
10946 /* Substitute the return type. */
10947 return_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10948 if (return_type == error_mark_node)
10949 return error_mark_node;
10950 /* The standard does not presently indicate that creation of a
10951 function type with an invalid return type is a deduction failure.
10952 However, that is clearly analogous to creating an array of "void"
10953 or a reference to a reference. This is core issue #486. */
10954 if (TREE_CODE (return_type) == ARRAY_TYPE
10955 || TREE_CODE (return_type) == FUNCTION_TYPE)
10957 if (complain & tf_error)
10959 if (TREE_CODE (return_type) == ARRAY_TYPE)
10960 error ("function returning an array");
10962 error ("function returning a function");
10964 return error_mark_node;
10967 /* Substitute the argument types. */
10968 arg_types = tsubst_arg_types (TYPE_ARG_TYPES (t), args,
10969 complain, in_decl);
10970 if (arg_types == error_mark_node)
10971 return error_mark_node;
10973 /* Construct a new type node and return it. */
10974 if (TREE_CODE (t) == FUNCTION_TYPE)
10976 fntype = build_function_type (return_type, arg_types);
10977 fntype = apply_memfn_quals (fntype, type_memfn_quals (t));
10981 tree r = TREE_TYPE (TREE_VALUE (arg_types));
10982 if (! MAYBE_CLASS_TYPE_P (r))
10986 Type deduction may fail for any of the following
10989 -- Attempting to create "pointer to member of T" when T
10990 is not a class type. */
10991 if (complain & tf_error)
10992 error ("creating pointer to member function of non-class type %qT",
10994 return error_mark_node;
10997 fntype = build_method_type_directly (r, return_type,
10998 TREE_CHAIN (arg_types));
11000 fntype = cp_build_type_attribute_variant (fntype, TYPE_ATTRIBUTES (t));
11005 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
11006 ARGS into that specification, and return the substituted
11007 specification. If there is no specification, return NULL_TREE. */
11010 tsubst_exception_specification (tree fntype,
11012 tsubst_flags_t complain,
11019 specs = TYPE_RAISES_EXCEPTIONS (fntype);
11020 new_specs = NULL_TREE;
11021 if (specs && TREE_PURPOSE (specs))
11023 /* A noexcept-specifier. */
11024 tree expr = TREE_PURPOSE (specs);
11025 if (expr == boolean_true_node || expr == boolean_false_node)
11029 /* Defer instantiation of noexcept-specifiers to avoid
11030 excessive instantiations (c++/49107). */
11031 new_specs = make_node (DEFERRED_NOEXCEPT);
11032 if (DEFERRED_NOEXCEPT_SPEC_P (specs))
11034 /* We already partially instantiated this member template,
11035 so combine the new args with the old. */
11036 DEFERRED_NOEXCEPT_PATTERN (new_specs)
11037 = DEFERRED_NOEXCEPT_PATTERN (expr);
11038 DEFERRED_NOEXCEPT_ARGS (new_specs)
11039 = add_to_template_args (DEFERRED_NOEXCEPT_ARGS (expr), args);
11043 DEFERRED_NOEXCEPT_PATTERN (new_specs) = expr;
11044 DEFERRED_NOEXCEPT_ARGS (new_specs) = args;
11048 new_specs = tsubst_copy_and_build
11049 (expr, args, complain, in_decl, /*function_p=*/false,
11050 /*integral_constant_expression_p=*/true);
11051 new_specs = build_noexcept_spec (new_specs, complain);
11055 if (! TREE_VALUE (specs))
11062 tree expanded_specs = NULL_TREE;
11064 if (PACK_EXPANSION_P (TREE_VALUE (specs)))
11066 /* Expand the pack expansion type. */
11067 expanded_specs = tsubst_pack_expansion (TREE_VALUE (specs),
11071 if (expanded_specs == error_mark_node)
11072 return error_mark_node;
11073 else if (TREE_CODE (expanded_specs) == TREE_VEC)
11074 len = TREE_VEC_LENGTH (expanded_specs);
11077 /* We're substituting into a member template, so
11078 we got a TYPE_PACK_EXPANSION back. Add that
11079 expansion and move on. */
11080 gcc_assert (TREE_CODE (expanded_specs)
11081 == TYPE_PACK_EXPANSION);
11082 new_specs = add_exception_specifier (new_specs,
11085 specs = TREE_CHAIN (specs);
11090 for (i = 0; i < len; ++i)
11092 if (expanded_specs)
11093 spec = TREE_VEC_ELT (expanded_specs, i);
11095 spec = tsubst (TREE_VALUE (specs), args, complain, in_decl);
11096 if (spec == error_mark_node)
11098 new_specs = add_exception_specifier (new_specs, spec,
11102 specs = TREE_CHAIN (specs);
11108 /* Take the tree structure T and replace template parameters used
11109 therein with the argument vector ARGS. IN_DECL is an associated
11110 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
11111 Issue error and warning messages under control of COMPLAIN. Note
11112 that we must be relatively non-tolerant of extensions here, in
11113 order to preserve conformance; if we allow substitutions that
11114 should not be allowed, we may allow argument deductions that should
11115 not succeed, and therefore report ambiguous overload situations
11116 where there are none. In theory, we could allow the substitution,
11117 but indicate that it should have failed, and allow our caller to
11118 make sure that the right thing happens, but we don't try to do this
11121 This function is used for dealing with types, decls and the like;
11122 for expressions, use tsubst_expr or tsubst_copy. */
11125 tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl)
11127 enum tree_code code;
11128 tree type, r = NULL_TREE;
11130 if (t == NULL_TREE || t == error_mark_node
11131 || t == integer_type_node
11132 || t == void_type_node
11133 || t == char_type_node
11134 || t == unknown_type_node
11135 || TREE_CODE (t) == NAMESPACE_DECL
11136 || TREE_CODE (t) == TRANSLATION_UNIT_DECL)
11140 return tsubst_decl (t, args, complain);
11142 if (args == NULL_TREE)
11145 code = TREE_CODE (t);
11147 if (code == IDENTIFIER_NODE)
11148 type = IDENTIFIER_TYPE_VALUE (t);
11150 type = TREE_TYPE (t);
11152 gcc_assert (type != unknown_type_node);
11154 /* Reuse typedefs. We need to do this to handle dependent attributes,
11155 such as attribute aligned. */
11157 && typedef_variant_p (t))
11159 tree decl = TYPE_NAME (t);
11161 if (TYPE_DECL_ALIAS_P (decl)
11162 && DECL_LANG_SPECIFIC (decl)
11163 && DECL_TEMPLATE_INFO (decl)
11164 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (decl)))
11166 /* DECL represents an alias template and we want to
11167 instantiate it. Let's substitute our arguments for the
11168 template parameters into the declaration and get the
11170 r = tsubst (decl, args, complain, decl);
11172 else if (DECL_CLASS_SCOPE_P (decl)
11173 && CLASSTYPE_TEMPLATE_INFO (DECL_CONTEXT (decl))
11174 && uses_template_parms (DECL_CONTEXT (decl)))
11176 tree tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
11177 tree gen_args = tsubst (DECL_TI_ARGS (decl), args, complain, in_decl);
11178 r = retrieve_specialization (tmpl, gen_args, 0);
11180 else if (DECL_FUNCTION_SCOPE_P (decl)
11181 && DECL_TEMPLATE_INFO (DECL_CONTEXT (decl))
11182 && uses_template_parms (DECL_TI_ARGS (DECL_CONTEXT (decl))))
11183 r = retrieve_local_specialization (decl);
11185 /* The typedef is from a non-template context. */
11191 r = cp_build_qualified_type_real
11192 (r, cp_type_quals (t) | cp_type_quals (r),
11193 complain | tf_ignore_bad_quals);
11197 /* We don't have an instantiation yet, so drop the typedef. */
11198 t = DECL_ORIGINAL_TYPE (decl);
11202 && code != TYPENAME_TYPE
11203 && code != TEMPLATE_TYPE_PARM
11204 && code != IDENTIFIER_NODE
11205 && code != FUNCTION_TYPE
11206 && code != METHOD_TYPE)
11207 type = tsubst (type, args, complain, in_decl);
11208 if (type == error_mark_node)
11209 return error_mark_node;
11215 case ENUMERAL_TYPE:
11216 return tsubst_aggr_type (t, args, complain, in_decl,
11217 /*entering_scope=*/0);
11220 case IDENTIFIER_NODE:
11231 if (t == integer_type_node)
11234 if (TREE_CODE (TYPE_MIN_VALUE (t)) == INTEGER_CST
11235 && TREE_CODE (TYPE_MAX_VALUE (t)) == INTEGER_CST)
11239 tree max, omax = TREE_OPERAND (TYPE_MAX_VALUE (t), 0);
11241 max = tsubst_expr (omax, args, complain, in_decl,
11242 /*integral_constant_expression_p=*/false);
11244 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
11246 if (TREE_CODE (max) == NOP_EXPR
11247 && TREE_SIDE_EFFECTS (omax)
11248 && !TREE_TYPE (max))
11249 TREE_TYPE (max) = TREE_TYPE (TREE_OPERAND (max, 0));
11251 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
11252 with TREE_SIDE_EFFECTS that indicates this is not an integral
11253 constant expression. */
11254 if (processing_template_decl
11255 && TREE_SIDE_EFFECTS (omax) && TREE_CODE (omax) == NOP_EXPR)
11257 gcc_assert (TREE_CODE (max) == NOP_EXPR);
11258 TREE_SIDE_EFFECTS (max) = 1;
11261 return compute_array_index_type (NULL_TREE, max, complain);
11264 case TEMPLATE_TYPE_PARM:
11265 case TEMPLATE_TEMPLATE_PARM:
11266 case BOUND_TEMPLATE_TEMPLATE_PARM:
11267 case TEMPLATE_PARM_INDEX:
11272 tree arg = NULL_TREE;
11276 gcc_assert (TREE_VEC_LENGTH (args) > 0);
11277 template_parm_level_and_index (t, &level, &idx);
11279 levels = TMPL_ARGS_DEPTH (args);
11280 if (level <= levels)
11282 arg = TMPL_ARG (args, level, idx);
11284 if (arg && TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
11285 /* See through ARGUMENT_PACK_SELECT arguments. */
11286 arg = ARGUMENT_PACK_SELECT_ARG (arg);
11289 if (arg == error_mark_node)
11290 return error_mark_node;
11291 else if (arg != NULL_TREE)
11293 if (ARGUMENT_PACK_P (arg))
11294 /* If ARG is an argument pack, we don't actually want to
11295 perform a substitution here, because substitutions
11296 for argument packs are only done
11297 element-by-element. We can get to this point when
11298 substituting the type of a non-type template
11299 parameter pack, when that type actually contains
11300 template parameter packs from an outer template, e.g.,
11302 template<typename... Types> struct A {
11303 template<Types... Values> struct B { };
11307 if (code == TEMPLATE_TYPE_PARM)
11310 gcc_assert (TYPE_P (arg));
11312 quals = cp_type_quals (arg) | cp_type_quals (t);
11314 return cp_build_qualified_type_real
11315 (arg, quals, complain | tf_ignore_bad_quals);
11317 else if (code == BOUND_TEMPLATE_TEMPLATE_PARM)
11319 /* We are processing a type constructed from a
11320 template template parameter. */
11321 tree argvec = tsubst (TYPE_TI_ARGS (t),
11322 args, complain, in_decl);
11323 if (argvec == error_mark_node)
11324 return error_mark_node;
11326 gcc_assert (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
11327 || TREE_CODE (arg) == TEMPLATE_DECL
11328 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE);
11330 if (TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE)
11331 /* Consider this code:
11333 template <template <class> class Template>
11335 template <class Arg> using Bind = Template<Arg>;
11338 template <template <class> class Template, class Arg>
11339 using Instantiate = Template<Arg>; //#0
11341 template <template <class> class Template,
11344 Instantiate<Internal<Template>::template Bind,
11347 When #1 is parsed, the
11348 BOUND_TEMPLATE_TEMPLATE_PARM representing the
11349 parameter `Template' in #0 matches the
11350 UNBOUND_CLASS_TEMPLATE representing the argument
11351 `Internal<Template>::template Bind'; We then want
11352 to assemble the type `Bind<Argument>' that can't
11353 be fully created right now, because
11354 `Internal<Template>' not being complete, the Bind
11355 template cannot be looked up in that context. So
11356 we need to "store" `Bind<Argument>' for later
11357 when the context of Bind becomes complete. Let's
11358 store that in a TYPENAME_TYPE. */
11359 return make_typename_type (TYPE_CONTEXT (arg),
11360 build_nt (TEMPLATE_ID_EXPR,
11361 TYPE_IDENTIFIER (arg),
11366 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
11367 are resolving nested-types in the signature of a
11368 member function templates. Otherwise ARG is a
11369 TEMPLATE_DECL and is the real template to be
11371 if (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
11372 arg = TYPE_NAME (arg);
11374 r = lookup_template_class (arg,
11376 DECL_CONTEXT (arg),
11377 /*entering_scope=*/0,
11379 return cp_build_qualified_type_real
11380 (r, cp_type_quals (t), complain);
11383 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
11384 return convert_from_reference (unshare_expr (arg));
11388 /* This can happen during the attempted tsubst'ing in
11389 unify. This means that we don't yet have any information
11390 about the template parameter in question. */
11393 /* If we get here, we must have been looking at a parm for a
11394 more deeply nested template. Make a new version of this
11395 template parameter, but with a lower level. */
11398 case TEMPLATE_TYPE_PARM:
11399 case TEMPLATE_TEMPLATE_PARM:
11400 case BOUND_TEMPLATE_TEMPLATE_PARM:
11401 if (cp_type_quals (t))
11403 r = tsubst (TYPE_MAIN_VARIANT (t), args, complain, in_decl);
11404 r = cp_build_qualified_type_real
11405 (r, cp_type_quals (t),
11406 complain | (code == TEMPLATE_TYPE_PARM
11407 ? tf_ignore_bad_quals : 0));
11412 TEMPLATE_TYPE_PARM_INDEX (r)
11413 = reduce_template_parm_level (TEMPLATE_TYPE_PARM_INDEX (t),
11414 r, levels, args, complain);
11415 TYPE_STUB_DECL (r) = TYPE_NAME (r) = TEMPLATE_TYPE_DECL (r);
11416 TYPE_MAIN_VARIANT (r) = r;
11417 TYPE_POINTER_TO (r) = NULL_TREE;
11418 TYPE_REFERENCE_TO (r) = NULL_TREE;
11420 if (TREE_CODE (r) == TEMPLATE_TEMPLATE_PARM)
11421 /* We have reduced the level of the template
11422 template parameter, but not the levels of its
11423 template parameters, so canonical_type_parameter
11424 will not be able to find the canonical template
11425 template parameter for this level. Thus, we
11426 require structural equality checking to compare
11427 TEMPLATE_TEMPLATE_PARMs. */
11428 SET_TYPE_STRUCTURAL_EQUALITY (r);
11429 else if (TYPE_STRUCTURAL_EQUALITY_P (t))
11430 SET_TYPE_STRUCTURAL_EQUALITY (r);
11432 TYPE_CANONICAL (r) = canonical_type_parameter (r);
11434 if (code == BOUND_TEMPLATE_TEMPLATE_PARM)
11436 tree argvec = tsubst (TYPE_TI_ARGS (t), args,
11437 complain, in_decl);
11438 if (argvec == error_mark_node)
11439 return error_mark_node;
11441 TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (r)
11442 = build_template_info (TYPE_TI_TEMPLATE (t), argvec);
11447 case TEMPLATE_PARM_INDEX:
11448 r = reduce_template_parm_level (t, type, levels, args, complain);
11452 gcc_unreachable ();
11460 tree purpose, value, chain;
11462 if (t == void_list_node)
11465 purpose = TREE_PURPOSE (t);
11468 purpose = tsubst (purpose, args, complain, in_decl);
11469 if (purpose == error_mark_node)
11470 return error_mark_node;
11472 value = TREE_VALUE (t);
11475 value = tsubst (value, args, complain, in_decl);
11476 if (value == error_mark_node)
11477 return error_mark_node;
11479 chain = TREE_CHAIN (t);
11480 if (chain && chain != void_type_node)
11482 chain = tsubst (chain, args, complain, in_decl);
11483 if (chain == error_mark_node)
11484 return error_mark_node;
11486 if (purpose == TREE_PURPOSE (t)
11487 && value == TREE_VALUE (t)
11488 && chain == TREE_CHAIN (t))
11490 return hash_tree_cons (purpose, value, chain);
11494 /* We should never be tsubsting a binfo. */
11495 gcc_unreachable ();
11498 /* A vector of template arguments. */
11499 gcc_assert (!type);
11500 return tsubst_template_args (t, args, complain, in_decl);
11503 case REFERENCE_TYPE:
11505 if (type == TREE_TYPE (t) && TREE_CODE (type) != METHOD_TYPE)
11510 Type deduction may fail for any of the following
11513 -- Attempting to create a pointer to reference type.
11514 -- Attempting to create a reference to a reference type or
11515 a reference to void.
11517 Core issue 106 says that creating a reference to a reference
11518 during instantiation is no longer a cause for failure. We
11519 only enforce this check in strict C++98 mode. */
11520 if ((TREE_CODE (type) == REFERENCE_TYPE
11521 && (((cxx_dialect == cxx98) && flag_iso) || code != REFERENCE_TYPE))
11522 || (code == REFERENCE_TYPE && TREE_CODE (type) == VOID_TYPE))
11524 static location_t last_loc;
11526 /* We keep track of the last time we issued this error
11527 message to avoid spewing a ton of messages during a
11528 single bad template instantiation. */
11529 if (complain & tf_error
11530 && last_loc != input_location)
11532 if (TREE_CODE (type) == VOID_TYPE)
11533 error ("forming reference to void");
11534 else if (code == POINTER_TYPE)
11535 error ("forming pointer to reference type %qT", type);
11537 error ("forming reference to reference type %qT", type);
11538 last_loc = input_location;
11541 return error_mark_node;
11543 else if (code == POINTER_TYPE)
11545 r = build_pointer_type (type);
11546 if (TREE_CODE (type) == METHOD_TYPE)
11547 r = build_ptrmemfunc_type (r);
11549 else if (TREE_CODE (type) == REFERENCE_TYPE)
11550 /* In C++0x, during template argument substitution, when there is an
11551 attempt to create a reference to a reference type, reference
11552 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
11554 "If a template-argument for a template-parameter T names a type
11555 that is a reference to a type A, an attempt to create the type
11556 'lvalue reference to cv T' creates the type 'lvalue reference to
11557 A,' while an attempt to create the type type rvalue reference to
11558 cv T' creates the type T"
11560 r = cp_build_reference_type
11562 TYPE_REF_IS_RVALUE (t) && TYPE_REF_IS_RVALUE (type));
11564 r = cp_build_reference_type (type, TYPE_REF_IS_RVALUE (t));
11565 r = cp_build_qualified_type_real (r, cp_type_quals (t), complain);
11567 if (r != error_mark_node)
11568 /* Will this ever be needed for TYPE_..._TO values? */
11575 r = tsubst (TYPE_OFFSET_BASETYPE (t), args, complain, in_decl);
11576 if (r == error_mark_node || !MAYBE_CLASS_TYPE_P (r))
11580 Type deduction may fail for any of the following
11583 -- Attempting to create "pointer to member of T" when T
11584 is not a class type. */
11585 if (complain & tf_error)
11586 error ("creating pointer to member of non-class type %qT", r);
11587 return error_mark_node;
11589 if (TREE_CODE (type) == REFERENCE_TYPE)
11591 if (complain & tf_error)
11592 error ("creating pointer to member reference type %qT", type);
11593 return error_mark_node;
11595 if (TREE_CODE (type) == VOID_TYPE)
11597 if (complain & tf_error)
11598 error ("creating pointer to member of type void");
11599 return error_mark_node;
11601 gcc_assert (TREE_CODE (type) != METHOD_TYPE);
11602 if (TREE_CODE (type) == FUNCTION_TYPE)
11604 /* The type of the implicit object parameter gets its
11605 cv-qualifiers from the FUNCTION_TYPE. */
11607 tree method_type = build_memfn_type (type, r, type_memfn_quals (type));
11608 memptr = build_ptrmemfunc_type (build_pointer_type (method_type));
11609 return cp_build_qualified_type_real (memptr, cp_type_quals (t),
11613 return cp_build_qualified_type_real (build_ptrmem_type (r, type),
11617 case FUNCTION_TYPE:
11622 fntype = tsubst_function_type (t, args, complain, in_decl);
11623 if (fntype == error_mark_node)
11624 return error_mark_node;
11626 /* Substitute the exception specification. */
11627 specs = tsubst_exception_specification (t, args, complain,
11628 in_decl, /*defer_ok*/true);
11629 if (specs == error_mark_node)
11630 return error_mark_node;
11632 fntype = build_exception_variant (fntype, specs);
11637 tree domain = tsubst (TYPE_DOMAIN (t), args, complain, in_decl);
11638 if (domain == error_mark_node)
11639 return error_mark_node;
11641 /* As an optimization, we avoid regenerating the array type if
11642 it will obviously be the same as T. */
11643 if (type == TREE_TYPE (t) && domain == TYPE_DOMAIN (t))
11646 /* These checks should match the ones in grokdeclarator.
11650 The deduction may fail for any of the following reasons:
11652 -- Attempting to create an array with an element type that
11653 is void, a function type, or a reference type, or [DR337]
11654 an abstract class type. */
11655 if (TREE_CODE (type) == VOID_TYPE
11656 || TREE_CODE (type) == FUNCTION_TYPE
11657 || TREE_CODE (type) == REFERENCE_TYPE)
11659 if (complain & tf_error)
11660 error ("creating array of %qT", type);
11661 return error_mark_node;
11663 if (CLASS_TYPE_P (type) && CLASSTYPE_PURE_VIRTUALS (type))
11665 if (complain & tf_error)
11666 error ("creating array of %qT, which is an abstract class type",
11668 return error_mark_node;
11671 r = build_cplus_array_type (type, domain);
11673 if (TYPE_USER_ALIGN (t))
11675 TYPE_ALIGN (r) = TYPE_ALIGN (t);
11676 TYPE_USER_ALIGN (r) = 1;
11682 case TYPENAME_TYPE:
11684 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
11685 in_decl, /*entering_scope=*/1);
11686 tree f = tsubst_copy (TYPENAME_TYPE_FULLNAME (t), args,
11687 complain, in_decl);
11689 if (ctx == error_mark_node || f == error_mark_node)
11690 return error_mark_node;
11692 if (!MAYBE_CLASS_TYPE_P (ctx))
11694 if (complain & tf_error)
11695 error ("%qT is not a class, struct, or union type", ctx);
11696 return error_mark_node;
11698 else if (!uses_template_parms (ctx) && !TYPE_BEING_DEFINED (ctx))
11700 /* Normally, make_typename_type does not require that the CTX
11701 have complete type in order to allow things like:
11703 template <class T> struct S { typename S<T>::X Y; };
11705 But, such constructs have already been resolved by this
11706 point, so here CTX really should have complete type, unless
11707 it's a partial instantiation. */
11708 ctx = complete_type (ctx);
11709 if (!COMPLETE_TYPE_P (ctx))
11711 if (complain & tf_error)
11712 cxx_incomplete_type_error (NULL_TREE, ctx);
11713 return error_mark_node;
11717 f = make_typename_type (ctx, f, typename_type,
11718 (complain & tf_error) | tf_keep_type_decl);
11719 if (f == error_mark_node)
11721 if (TREE_CODE (f) == TYPE_DECL)
11723 complain |= tf_ignore_bad_quals;
11727 if (TREE_CODE (f) != TYPENAME_TYPE)
11729 if (TYPENAME_IS_ENUM_P (t) && TREE_CODE (f) != ENUMERAL_TYPE)
11731 if (complain & tf_error)
11732 error ("%qT resolves to %qT, which is not an enumeration type",
11735 return error_mark_node;
11737 else if (TYPENAME_IS_CLASS_P (t) && !CLASS_TYPE_P (f))
11739 if (complain & tf_error)
11740 error ("%qT resolves to %qT, which is is not a class type",
11743 return error_mark_node;
11747 return cp_build_qualified_type_real
11748 (f, cp_type_quals (f) | cp_type_quals (t), complain);
11751 case UNBOUND_CLASS_TEMPLATE:
11753 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
11754 in_decl, /*entering_scope=*/1);
11755 tree name = TYPE_IDENTIFIER (t);
11756 tree parm_list = DECL_TEMPLATE_PARMS (TYPE_NAME (t));
11758 if (ctx == error_mark_node || name == error_mark_node)
11759 return error_mark_node;
11762 parm_list = tsubst_template_parms (parm_list, args, complain);
11763 return make_unbound_class_template (ctx, name, parm_list, complain);
11770 ++cp_unevaluated_operand;
11771 ++c_inhibit_evaluation_warnings;
11773 type = tsubst_expr (TYPEOF_TYPE_EXPR (t), args,
11775 /*integral_constant_expression_p=*/false);
11777 --cp_unevaluated_operand;
11778 --c_inhibit_evaluation_warnings;
11780 type = finish_typeof (type);
11781 return cp_build_qualified_type_real (type,
11783 | cp_type_quals (type),
11787 case DECLTYPE_TYPE:
11791 ++cp_unevaluated_operand;
11792 ++c_inhibit_evaluation_warnings;
11794 type = tsubst_expr (DECLTYPE_TYPE_EXPR (t), args,
11796 /*integral_constant_expression_p=*/false);
11798 --cp_unevaluated_operand;
11799 --c_inhibit_evaluation_warnings;
11801 if (DECLTYPE_FOR_LAMBDA_CAPTURE (t))
11802 type = lambda_capture_field_type (type);
11803 else if (DECLTYPE_FOR_LAMBDA_PROXY (t))
11804 type = lambda_proxy_type (type);
11806 type = finish_decltype_type
11807 (type, DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t), complain);
11808 return cp_build_qualified_type_real (type,
11810 | cp_type_quals (type),
11814 case UNDERLYING_TYPE:
11816 tree type = tsubst (UNDERLYING_TYPE_TYPE (t), args,
11817 complain, in_decl);
11818 return finish_underlying_type (type);
11821 case TYPE_ARGUMENT_PACK:
11822 case NONTYPE_ARGUMENT_PACK:
11824 tree r = TYPE_P (t) ? cxx_make_type (code) : make_node (code);
11826 tsubst_template_args (ARGUMENT_PACK_ARGS (t),
11830 SET_ARGUMENT_PACK_ARGS (r, packed_out);
11832 /* For template nontype argument packs, also substitute into
11834 if (code == NONTYPE_ARGUMENT_PACK)
11835 TREE_TYPE (r) = tsubst (TREE_TYPE (t), args, complain, in_decl);
11853 /* We should use one of the expression tsubsts for these codes. */
11854 gcc_unreachable ();
11857 sorry ("use of %qs in template", tree_code_name [(int) code]);
11858 return error_mark_node;
11862 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
11863 type of the expression on the left-hand side of the "." or "->"
11867 tsubst_baselink (tree baselink, tree object_type,
11868 tree args, tsubst_flags_t complain, tree in_decl)
11871 tree qualifying_scope;
11874 tree template_args = 0;
11875 bool template_id_p = false;
11876 bool qualified = BASELINK_QUALIFIED_P (baselink);
11878 /* A baselink indicates a function from a base class. Both the
11879 BASELINK_ACCESS_BINFO and the base class referenced may
11880 indicate bases of the template class, rather than the
11881 instantiated class. In addition, lookups that were not
11882 ambiguous before may be ambiguous now. Therefore, we perform
11883 the lookup again. */
11884 qualifying_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (baselink));
11885 qualifying_scope = tsubst (qualifying_scope, args,
11886 complain, in_decl);
11887 fns = BASELINK_FUNCTIONS (baselink);
11888 optype = tsubst (BASELINK_OPTYPE (baselink), args, complain, in_decl);
11889 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
11891 template_id_p = true;
11892 template_args = TREE_OPERAND (fns, 1);
11893 fns = TREE_OPERAND (fns, 0);
11895 template_args = tsubst_template_args (template_args, args,
11896 complain, in_decl);
11898 name = DECL_NAME (get_first_fn (fns));
11899 if (IDENTIFIER_TYPENAME_P (name))
11900 name = mangle_conv_op_name_for_type (optype);
11901 baselink = lookup_fnfields (qualifying_scope, name, /*protect=*/1);
11903 return error_mark_node;
11905 /* If lookup found a single function, mark it as used at this
11906 point. (If it lookup found multiple functions the one selected
11907 later by overload resolution will be marked as used at that
11909 if (BASELINK_P (baselink))
11910 fns = BASELINK_FUNCTIONS (baselink);
11911 if (!template_id_p && !really_overloaded_fn (fns))
11912 mark_used (OVL_CURRENT (fns));
11914 /* Add back the template arguments, if present. */
11915 if (BASELINK_P (baselink) && template_id_p)
11916 BASELINK_FUNCTIONS (baselink)
11917 = build_nt (TEMPLATE_ID_EXPR,
11918 BASELINK_FUNCTIONS (baselink),
11920 /* Update the conversion operator type. */
11921 BASELINK_OPTYPE (baselink) = optype;
11924 object_type = current_class_type;
11927 baselink = adjust_result_of_qualified_name_lookup (baselink,
11933 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
11934 true if the qualified-id will be a postfix-expression in-and-of
11935 itself; false if more of the postfix-expression follows the
11936 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
11940 tsubst_qualified_id (tree qualified_id, tree args,
11941 tsubst_flags_t complain, tree in_decl,
11942 bool done, bool address_p)
11948 tree template_args;
11950 gcc_assert (TREE_CODE (qualified_id) == SCOPE_REF);
11952 /* Figure out what name to look up. */
11953 name = TREE_OPERAND (qualified_id, 1);
11954 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
11956 is_template = true;
11957 template_args = TREE_OPERAND (name, 1);
11959 template_args = tsubst_template_args (template_args, args,
11960 complain, in_decl);
11961 name = TREE_OPERAND (name, 0);
11965 is_template = false;
11966 template_args = NULL_TREE;
11969 /* Substitute into the qualifying scope. When there are no ARGS, we
11970 are just trying to simplify a non-dependent expression. In that
11971 case the qualifying scope may be dependent, and, in any case,
11972 substituting will not help. */
11973 scope = TREE_OPERAND (qualified_id, 0);
11976 scope = tsubst (scope, args, complain, in_decl);
11977 expr = tsubst_copy (name, args, complain, in_decl);
11982 if (dependent_scope_p (scope))
11985 expr = build_min_nt (TEMPLATE_ID_EXPR, expr, template_args);
11986 return build_qualified_name (NULL_TREE, scope, expr,
11987 QUALIFIED_NAME_IS_TEMPLATE (qualified_id));
11990 if (!BASELINK_P (name) && !DECL_P (expr))
11992 if (TREE_CODE (expr) == BIT_NOT_EXPR)
11994 /* A BIT_NOT_EXPR is used to represent a destructor. */
11995 if (!check_dtor_name (scope, TREE_OPERAND (expr, 0)))
11997 error ("qualifying type %qT does not match destructor name ~%qT",
11998 scope, TREE_OPERAND (expr, 0));
11999 expr = error_mark_node;
12002 expr = lookup_qualified_name (scope, complete_dtor_identifier,
12003 /*is_type_p=*/0, false);
12006 expr = lookup_qualified_name (scope, expr, /*is_type_p=*/0, false);
12007 if (TREE_CODE (TREE_CODE (expr) == TEMPLATE_DECL
12008 ? DECL_TEMPLATE_RESULT (expr) : expr) == TYPE_DECL)
12010 if (complain & tf_error)
12012 error ("dependent-name %qE is parsed as a non-type, but "
12013 "instantiation yields a type", qualified_id);
12014 inform (input_location, "say %<typename %E%> if a type is meant", qualified_id);
12016 return error_mark_node;
12022 check_accessibility_of_qualified_id (expr, /*object_type=*/NULL_TREE,
12024 /* Remember that there was a reference to this entity. */
12028 if (expr == error_mark_node || TREE_CODE (expr) == TREE_LIST)
12030 if (complain & tf_error)
12031 qualified_name_lookup_error (scope,
12032 TREE_OPERAND (qualified_id, 1),
12033 expr, input_location);
12034 return error_mark_node;
12038 expr = lookup_template_function (expr, template_args);
12040 if (expr == error_mark_node && complain & tf_error)
12041 qualified_name_lookup_error (scope, TREE_OPERAND (qualified_id, 1),
12042 expr, input_location);
12043 else if (TYPE_P (scope))
12045 expr = (adjust_result_of_qualified_name_lookup
12046 (expr, scope, current_class_type));
12047 expr = (finish_qualified_id_expr
12048 (scope, expr, done, address_p && PTRMEM_OK_P (qualified_id),
12049 QUALIFIED_NAME_IS_TEMPLATE (qualified_id),
12050 /*template_arg_p=*/false));
12053 /* Expressions do not generally have reference type. */
12054 if (TREE_CODE (expr) != SCOPE_REF
12055 /* However, if we're about to form a pointer-to-member, we just
12056 want the referenced member referenced. */
12057 && TREE_CODE (expr) != OFFSET_REF)
12058 expr = convert_from_reference (expr);
12063 /* Like tsubst, but deals with expressions. This function just replaces
12064 template parms; to finish processing the resultant expression, use
12065 tsubst_copy_and_build or tsubst_expr. */
12068 tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl)
12070 enum tree_code code;
12073 if (t == NULL_TREE || t == error_mark_node || args == NULL_TREE)
12076 code = TREE_CODE (t);
12081 r = retrieve_local_specialization (t);
12087 /* We get here for a use of 'this' in an NSDMI. */
12088 if (DECL_NAME (t) == this_identifier
12089 && at_function_scope_p ()
12090 && DECL_CONSTRUCTOR_P (current_function_decl))
12091 return current_class_ptr;
12093 /* This can happen for a parameter name used later in a function
12094 declaration (such as in a late-specified return type). Just
12095 make a dummy decl, since it's only used for its type. */
12096 gcc_assert (cp_unevaluated_operand != 0);
12097 /* We copy T because want to tsubst the PARM_DECL only,
12098 not the following PARM_DECLs that are chained to T. */
12100 r = tsubst_decl (c, args, complain);
12101 /* Give it the template pattern as its context; its true context
12102 hasn't been instantiated yet and this is good enough for
12104 DECL_CONTEXT (r) = DECL_CONTEXT (t);
12107 if (TREE_CODE (r) == ARGUMENT_PACK_SELECT)
12108 r = ARGUMENT_PACK_SELECT_ARG (r);
12117 if (DECL_TEMPLATE_PARM_P (t))
12118 return tsubst_copy (DECL_INITIAL (t), args, complain, in_decl);
12119 /* There is no need to substitute into namespace-scope
12121 if (DECL_NAMESPACE_SCOPE_P (t))
12123 /* If ARGS is NULL, then T is known to be non-dependent. */
12124 if (args == NULL_TREE)
12125 return integral_constant_value (t);
12127 /* Unfortunately, we cannot just call lookup_name here.
12130 template <int I> int f() {
12132 struct S { void g() { E e = a; } };
12135 When we instantiate f<7>::S::g(), say, lookup_name is not
12136 clever enough to find f<7>::a. */
12138 = tsubst_aggr_type (TREE_TYPE (t), args, complain, in_decl,
12139 /*entering_scope=*/0);
12141 for (v = TYPE_VALUES (enum_type);
12143 v = TREE_CHAIN (v))
12144 if (TREE_PURPOSE (v) == DECL_NAME (t))
12145 return TREE_VALUE (v);
12147 /* We didn't find the name. That should never happen; if
12148 name-lookup found it during preliminary parsing, we
12149 should find it again here during instantiation. */
12150 gcc_unreachable ();
12155 if (DECL_CONTEXT (t))
12159 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args, complain, in_decl,
12160 /*entering_scope=*/1);
12161 if (ctx != DECL_CONTEXT (t))
12163 tree r = lookup_field (ctx, DECL_NAME (t), 0, false);
12166 if (complain & tf_error)
12167 error ("using invalid field %qD", t);
12168 return error_mark_node;
12177 case FUNCTION_DECL:
12178 if ((DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t))
12179 || local_variable_p (t))
12180 t = tsubst (t, args, complain, in_decl);
12184 case NAMESPACE_DECL:
12188 /* An OVERLOAD will always be a non-dependent overload set; an
12189 overload set from function scope will just be represented with an
12190 IDENTIFIER_NODE, and from class scope with a BASELINK. */
12191 gcc_assert (!uses_template_parms (t));
12195 return tsubst_baselink (t, current_class_type, args, complain, in_decl);
12197 case TEMPLATE_DECL:
12198 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
12199 return tsubst (TREE_TYPE (DECL_TEMPLATE_RESULT (t)),
12200 args, complain, in_decl);
12201 else if (DECL_FUNCTION_TEMPLATE_P (t) && DECL_MEMBER_TEMPLATE_P (t))
12202 return tsubst (t, args, complain, in_decl);
12203 else if (DECL_CLASS_SCOPE_P (t)
12204 && uses_template_parms (DECL_CONTEXT (t)))
12206 /* Template template argument like the following example need
12209 template <template <class> class TT> struct C {};
12210 template <class T> struct D {
12211 template <class U> struct E {};
12216 We are processing the template argument `E' in #1 for
12217 the template instantiation #2. Originally, `E' is a
12218 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
12219 have to substitute this with one having context `D<int>'. */
12221 tree context = tsubst (DECL_CONTEXT (t), args, complain, in_decl);
12222 return lookup_field (context, DECL_NAME(t), 0, false);
12225 /* Ordinary template template argument. */
12229 case REINTERPRET_CAST_EXPR:
12230 case CONST_CAST_EXPR:
12231 case STATIC_CAST_EXPR:
12232 case DYNAMIC_CAST_EXPR:
12233 case IMPLICIT_CONV_EXPR:
12237 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
12238 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
12241 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
12247 ++cp_unevaluated_operand;
12248 ++c_inhibit_evaluation_warnings;
12249 /* We only want to compute the number of arguments. */
12250 expanded = tsubst_pack_expansion (TREE_OPERAND (t, 0), args,
12251 complain, in_decl);
12252 --cp_unevaluated_operand;
12253 --c_inhibit_evaluation_warnings;
12255 if (TREE_CODE (expanded) == TREE_VEC)
12256 len = TREE_VEC_LENGTH (expanded);
12258 if (expanded == error_mark_node)
12259 return error_mark_node;
12260 else if (PACK_EXPANSION_P (expanded)
12261 || (TREE_CODE (expanded) == TREE_VEC
12263 && PACK_EXPANSION_P (TREE_VEC_ELT (expanded, len-1))))
12265 if (TREE_CODE (expanded) == TREE_VEC)
12266 expanded = TREE_VEC_ELT (expanded, len - 1);
12268 if (TYPE_P (expanded))
12269 return cxx_sizeof_or_alignof_type (expanded, SIZEOF_EXPR,
12270 complain & tf_error);
12272 return cxx_sizeof_or_alignof_expr (expanded, SIZEOF_EXPR,
12273 complain & tf_error);
12276 return build_int_cst (size_type_node, len);
12282 case TRUTH_NOT_EXPR:
12285 case UNARY_PLUS_EXPR: /* Unary + */
12287 case AT_ENCODE_EXPR:
12291 case REALPART_EXPR:
12292 case IMAGPART_EXPR:
12294 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
12295 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
12297 case COMPONENT_REF:
12302 object = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
12303 name = TREE_OPERAND (t, 1);
12304 if (TREE_CODE (name) == BIT_NOT_EXPR)
12306 name = tsubst_copy (TREE_OPERAND (name, 0), args,
12307 complain, in_decl);
12308 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
12310 else if (TREE_CODE (name) == SCOPE_REF
12311 && TREE_CODE (TREE_OPERAND (name, 1)) == BIT_NOT_EXPR)
12313 tree base = tsubst_copy (TREE_OPERAND (name, 0), args,
12314 complain, in_decl);
12315 name = TREE_OPERAND (name, 1);
12316 name = tsubst_copy (TREE_OPERAND (name, 0), args,
12317 complain, in_decl);
12318 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
12319 name = build_qualified_name (/*type=*/NULL_TREE,
12321 /*template_p=*/false);
12323 else if (BASELINK_P (name))
12324 name = tsubst_baselink (name,
12325 non_reference (TREE_TYPE (object)),
12329 name = tsubst_copy (name, args, complain, in_decl);
12330 return build_nt (COMPONENT_REF, object, name, NULL_TREE);
12336 case TRUNC_DIV_EXPR:
12337 case CEIL_DIV_EXPR:
12338 case FLOOR_DIV_EXPR:
12339 case ROUND_DIV_EXPR:
12340 case EXACT_DIV_EXPR:
12344 case TRUNC_MOD_EXPR:
12345 case FLOOR_MOD_EXPR:
12346 case TRUTH_ANDIF_EXPR:
12347 case TRUTH_ORIF_EXPR:
12348 case TRUTH_AND_EXPR:
12349 case TRUTH_OR_EXPR:
12362 case COMPOUND_EXPR:
12365 case PREDECREMENT_EXPR:
12366 case PREINCREMENT_EXPR:
12367 case POSTDECREMENT_EXPR:
12368 case POSTINCREMENT_EXPR:
12370 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12371 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
12374 return build_qualified_name (/*type=*/NULL_TREE,
12375 tsubst_copy (TREE_OPERAND (t, 0),
12376 args, complain, in_decl),
12377 tsubst_copy (TREE_OPERAND (t, 1),
12378 args, complain, in_decl),
12379 QUALIFIED_NAME_IS_TEMPLATE (t));
12384 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12385 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
12386 NULL_TREE, NULL_TREE);
12390 int n = VL_EXP_OPERAND_LENGTH (t);
12391 tree result = build_vl_exp (CALL_EXPR, n);
12393 for (i = 0; i < n; i++)
12394 TREE_OPERAND (t, i) = tsubst_copy (TREE_OPERAND (t, i), args,
12395 complain, in_decl);
12401 case PSEUDO_DTOR_EXPR:
12404 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12405 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
12406 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
12407 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
12414 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12415 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
12416 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
12417 NEW_EXPR_USE_GLOBAL (r) = NEW_EXPR_USE_GLOBAL (t);
12424 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12425 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
12426 DELETE_EXPR_USE_GLOBAL (r) = DELETE_EXPR_USE_GLOBAL (t);
12427 DELETE_EXPR_USE_VEC (r) = DELETE_EXPR_USE_VEC (t);
12431 case TEMPLATE_ID_EXPR:
12433 /* Substituted template arguments */
12434 tree fn = TREE_OPERAND (t, 0);
12435 tree targs = TREE_OPERAND (t, 1);
12437 fn = tsubst_copy (fn, args, complain, in_decl);
12439 targs = tsubst_template_args (targs, args, complain, in_decl);
12441 return lookup_template_function (fn, targs);
12446 tree purpose, value, chain;
12448 if (t == void_list_node)
12451 purpose = TREE_PURPOSE (t);
12453 purpose = tsubst_copy (purpose, args, complain, in_decl);
12454 value = TREE_VALUE (t);
12456 value = tsubst_copy (value, args, complain, in_decl);
12457 chain = TREE_CHAIN (t);
12458 if (chain && chain != void_type_node)
12459 chain = tsubst_copy (chain, args, complain, in_decl);
12460 if (purpose == TREE_PURPOSE (t)
12461 && value == TREE_VALUE (t)
12462 && chain == TREE_CHAIN (t))
12464 return tree_cons (purpose, value, chain);
12469 case ENUMERAL_TYPE:
12471 case TEMPLATE_TYPE_PARM:
12472 case TEMPLATE_TEMPLATE_PARM:
12473 case BOUND_TEMPLATE_TEMPLATE_PARM:
12474 case TEMPLATE_PARM_INDEX:
12476 case REFERENCE_TYPE:
12478 case FUNCTION_TYPE:
12481 case TYPENAME_TYPE:
12482 case UNBOUND_CLASS_TEMPLATE:
12484 case DECLTYPE_TYPE:
12486 return tsubst (t, args, complain, in_decl);
12488 case IDENTIFIER_NODE:
12489 if (IDENTIFIER_TYPENAME_P (t))
12491 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12492 return mangle_conv_op_name_for_type (new_type);
12498 /* This is handled by tsubst_copy_and_build. */
12499 gcc_unreachable ();
12502 return build_x_va_arg (tsubst_copy (TREE_OPERAND (t, 0), args, complain,
12504 tsubst (TREE_TYPE (t), args, complain, in_decl));
12506 case CLEANUP_POINT_EXPR:
12507 /* We shouldn't have built any of these during initial template
12508 generation. Instead, they should be built during instantiation
12509 in response to the saved STMT_IS_FULL_EXPR_P setting. */
12510 gcc_unreachable ();
12514 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
12515 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
12516 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
12517 PTRMEM_OK_P (r) = PTRMEM_OK_P (t);
12518 mark_used (TREE_OPERAND (r, 1));
12521 case EXPR_PACK_EXPANSION:
12522 error ("invalid use of pack expansion expression");
12523 return error_mark_node;
12525 case NONTYPE_ARGUMENT_PACK:
12526 error ("use %<...%> to expand argument pack");
12527 return error_mark_node;
12534 /* Instantiate any typedefs in the type. */
12535 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12536 r = fold_convert (type, t);
12537 gcc_assert (TREE_CODE (r) == code);
12542 /* These can sometimes show up in a partial instantiation, but never
12543 involve template parms. */
12544 gcc_assert (!uses_template_parms (t));
12548 /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */
12549 gcc_checking_assert (false);
12554 /* Like tsubst_copy, but specifically for OpenMP clauses. */
12557 tsubst_omp_clauses (tree clauses, tree args, tsubst_flags_t complain,
12560 tree new_clauses = NULL, nc, oc;
12562 for (oc = clauses; oc ; oc = OMP_CLAUSE_CHAIN (oc))
12564 nc = copy_node (oc);
12565 OMP_CLAUSE_CHAIN (nc) = new_clauses;
12568 switch (OMP_CLAUSE_CODE (nc))
12570 case OMP_CLAUSE_LASTPRIVATE:
12571 if (OMP_CLAUSE_LASTPRIVATE_STMT (oc))
12573 OMP_CLAUSE_LASTPRIVATE_STMT (nc) = push_stmt_list ();
12574 tsubst_expr (OMP_CLAUSE_LASTPRIVATE_STMT (oc), args, complain,
12575 in_decl, /*integral_constant_expression_p=*/false);
12576 OMP_CLAUSE_LASTPRIVATE_STMT (nc)
12577 = pop_stmt_list (OMP_CLAUSE_LASTPRIVATE_STMT (nc));
12580 case OMP_CLAUSE_PRIVATE:
12581 case OMP_CLAUSE_SHARED:
12582 case OMP_CLAUSE_FIRSTPRIVATE:
12583 case OMP_CLAUSE_REDUCTION:
12584 case OMP_CLAUSE_COPYIN:
12585 case OMP_CLAUSE_COPYPRIVATE:
12586 case OMP_CLAUSE_IF:
12587 case OMP_CLAUSE_NUM_THREADS:
12588 case OMP_CLAUSE_SCHEDULE:
12589 case OMP_CLAUSE_COLLAPSE:
12590 case OMP_CLAUSE_FINAL:
12591 OMP_CLAUSE_OPERAND (nc, 0)
12592 = tsubst_expr (OMP_CLAUSE_OPERAND (oc, 0), args, complain,
12593 in_decl, /*integral_constant_expression_p=*/false);
12595 case OMP_CLAUSE_NOWAIT:
12596 case OMP_CLAUSE_ORDERED:
12597 case OMP_CLAUSE_DEFAULT:
12598 case OMP_CLAUSE_UNTIED:
12599 case OMP_CLAUSE_MERGEABLE:
12602 gcc_unreachable ();
12606 return finish_omp_clauses (nreverse (new_clauses));
12609 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
12612 tsubst_copy_asm_operands (tree t, tree args, tsubst_flags_t complain,
12615 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
12617 tree purpose, value, chain;
12622 if (TREE_CODE (t) != TREE_LIST)
12623 return tsubst_copy_and_build (t, args, complain, in_decl,
12624 /*function_p=*/false,
12625 /*integral_constant_expression_p=*/false);
12627 if (t == void_list_node)
12630 purpose = TREE_PURPOSE (t);
12632 purpose = RECUR (purpose);
12633 value = TREE_VALUE (t);
12636 if (TREE_CODE (value) != LABEL_DECL)
12637 value = RECUR (value);
12640 value = lookup_label (DECL_NAME (value));
12641 gcc_assert (TREE_CODE (value) == LABEL_DECL);
12642 TREE_USED (value) = 1;
12645 chain = TREE_CHAIN (t);
12646 if (chain && chain != void_type_node)
12647 chain = RECUR (chain);
12648 return tree_cons (purpose, value, chain);
12652 /* Substitute one OMP_FOR iterator. */
12655 tsubst_omp_for_iterator (tree t, int i, tree declv, tree initv,
12656 tree condv, tree incrv, tree *clauses,
12657 tree args, tsubst_flags_t complain, tree in_decl,
12658 bool integral_constant_expression_p)
12660 #define RECUR(NODE) \
12661 tsubst_expr ((NODE), args, complain, in_decl, \
12662 integral_constant_expression_p)
12663 tree decl, init, cond, incr, auto_node;
12665 init = TREE_VEC_ELT (OMP_FOR_INIT (t), i);
12666 gcc_assert (TREE_CODE (init) == MODIFY_EXPR);
12667 decl = RECUR (TREE_OPERAND (init, 0));
12668 init = TREE_OPERAND (init, 1);
12669 auto_node = type_uses_auto (TREE_TYPE (decl));
12670 if (auto_node && init)
12672 tree init_expr = init;
12673 if (TREE_CODE (init_expr) == DECL_EXPR)
12674 init_expr = DECL_INITIAL (DECL_EXPR_DECL (init_expr));
12675 init_expr = RECUR (init_expr);
12677 = do_auto_deduction (TREE_TYPE (decl), init_expr, auto_node);
12679 gcc_assert (!type_dependent_expression_p (decl));
12681 if (!CLASS_TYPE_P (TREE_TYPE (decl)))
12683 cond = RECUR (TREE_VEC_ELT (OMP_FOR_COND (t), i));
12684 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
12685 if (TREE_CODE (incr) == MODIFY_EXPR)
12686 incr = build_x_modify_expr (RECUR (TREE_OPERAND (incr, 0)), NOP_EXPR,
12687 RECUR (TREE_OPERAND (incr, 1)),
12690 incr = RECUR (incr);
12691 TREE_VEC_ELT (declv, i) = decl;
12692 TREE_VEC_ELT (initv, i) = init;
12693 TREE_VEC_ELT (condv, i) = cond;
12694 TREE_VEC_ELT (incrv, i) = incr;
12698 if (init && TREE_CODE (init) != DECL_EXPR)
12701 for (c = *clauses; c ; c = OMP_CLAUSE_CHAIN (c))
12703 if ((OMP_CLAUSE_CODE (c) == OMP_CLAUSE_PRIVATE
12704 || OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LASTPRIVATE)
12705 && OMP_CLAUSE_DECL (c) == decl)
12707 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_FIRSTPRIVATE
12708 && OMP_CLAUSE_DECL (c) == decl)
12709 error ("iteration variable %qD should not be firstprivate", decl);
12710 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_REDUCTION
12711 && OMP_CLAUSE_DECL (c) == decl)
12712 error ("iteration variable %qD should not be reduction", decl);
12716 c = build_omp_clause (input_location, OMP_CLAUSE_PRIVATE);
12717 OMP_CLAUSE_DECL (c) = decl;
12718 c = finish_omp_clauses (c);
12721 OMP_CLAUSE_CHAIN (c) = *clauses;
12726 cond = TREE_VEC_ELT (OMP_FOR_COND (t), i);
12727 if (COMPARISON_CLASS_P (cond))
12728 cond = build2 (TREE_CODE (cond), boolean_type_node,
12729 RECUR (TREE_OPERAND (cond, 0)),
12730 RECUR (TREE_OPERAND (cond, 1)));
12732 cond = RECUR (cond);
12733 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
12734 switch (TREE_CODE (incr))
12736 case PREINCREMENT_EXPR:
12737 case PREDECREMENT_EXPR:
12738 case POSTINCREMENT_EXPR:
12739 case POSTDECREMENT_EXPR:
12740 incr = build2 (TREE_CODE (incr), TREE_TYPE (decl),
12741 RECUR (TREE_OPERAND (incr, 0)), NULL_TREE);
12744 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
12745 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
12747 tree rhs = TREE_OPERAND (incr, 1);
12748 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
12749 RECUR (TREE_OPERAND (incr, 0)),
12750 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
12751 RECUR (TREE_OPERAND (rhs, 0)),
12752 RECUR (TREE_OPERAND (rhs, 1))));
12755 incr = RECUR (incr);
12758 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
12759 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
12761 tree lhs = RECUR (TREE_OPERAND (incr, 0));
12762 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl), lhs,
12763 build2 (TREE_CODE (TREE_OPERAND (incr, 1)),
12764 TREE_TYPE (decl), lhs,
12765 RECUR (TREE_OPERAND (incr, 2))));
12767 else if (TREE_CODE (TREE_OPERAND (incr, 1)) == NOP_EXPR
12768 && (TREE_CODE (TREE_OPERAND (incr, 2)) == PLUS_EXPR
12769 || (TREE_CODE (TREE_OPERAND (incr, 2)) == MINUS_EXPR)))
12771 tree rhs = TREE_OPERAND (incr, 2);
12772 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
12773 RECUR (TREE_OPERAND (incr, 0)),
12774 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
12775 RECUR (TREE_OPERAND (rhs, 0)),
12776 RECUR (TREE_OPERAND (rhs, 1))));
12779 incr = RECUR (incr);
12782 incr = RECUR (incr);
12786 TREE_VEC_ELT (declv, i) = decl;
12787 TREE_VEC_ELT (initv, i) = init;
12788 TREE_VEC_ELT (condv, i) = cond;
12789 TREE_VEC_ELT (incrv, i) = incr;
12793 /* Like tsubst_copy for expressions, etc. but also does semantic
12797 tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl,
12798 bool integral_constant_expression_p)
12800 #define RECUR(NODE) \
12801 tsubst_expr ((NODE), args, complain, in_decl, \
12802 integral_constant_expression_p)
12806 if (t == NULL_TREE || t == error_mark_node)
12809 if (EXPR_HAS_LOCATION (t))
12810 input_location = EXPR_LOCATION (t);
12811 if (STATEMENT_CODE_P (TREE_CODE (t)))
12812 current_stmt_tree ()->stmts_are_full_exprs_p = STMT_IS_FULL_EXPR_P (t);
12814 switch (TREE_CODE (t))
12816 case STATEMENT_LIST:
12818 tree_stmt_iterator i;
12819 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
12820 RECUR (tsi_stmt (i));
12824 case CTOR_INITIALIZER:
12825 finish_mem_initializers (tsubst_initializer_list
12826 (TREE_OPERAND (t, 0), args));
12830 finish_return_stmt (RECUR (TREE_OPERAND (t, 0)));
12834 tmp = RECUR (EXPR_STMT_EXPR (t));
12835 if (EXPR_STMT_STMT_EXPR_RESULT (t))
12836 finish_stmt_expr_expr (tmp, cur_stmt_expr);
12838 finish_expr_stmt (tmp);
12842 do_using_directive (USING_STMT_NAMESPACE (t));
12847 tree decl, pattern_decl;
12850 pattern_decl = decl = DECL_EXPR_DECL (t);
12851 if (TREE_CODE (decl) == LABEL_DECL)
12852 finish_label_decl (DECL_NAME (decl));
12853 else if (TREE_CODE (decl) == USING_DECL)
12855 tree scope = USING_DECL_SCOPE (decl);
12856 tree name = DECL_NAME (decl);
12859 scope = tsubst (scope, args, complain, in_decl);
12860 decl = lookup_qualified_name (scope, name,
12861 /*is_type_p=*/false,
12862 /*complain=*/false);
12863 if (decl == error_mark_node || TREE_CODE (decl) == TREE_LIST)
12864 qualified_name_lookup_error (scope, name, decl, input_location);
12866 do_local_using_decl (decl, scope, name);
12870 init = DECL_INITIAL (decl);
12871 decl = tsubst (decl, args, complain, in_decl);
12872 if (decl != error_mark_node)
12874 /* By marking the declaration as instantiated, we avoid
12875 trying to instantiate it. Since instantiate_decl can't
12876 handle local variables, and since we've already done
12877 all that needs to be done, that's the right thing to
12879 if (TREE_CODE (decl) == VAR_DECL)
12880 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
12881 if (TREE_CODE (decl) == VAR_DECL
12882 && ANON_AGGR_TYPE_P (TREE_TYPE (decl)))
12883 /* Anonymous aggregates are a special case. */
12884 finish_anon_union (decl);
12885 else if (is_capture_proxy (DECL_EXPR_DECL (t)))
12887 DECL_CONTEXT (decl) = current_function_decl;
12888 insert_capture_proxy (decl);
12892 int const_init = false;
12893 maybe_push_decl (decl);
12894 if (TREE_CODE (decl) == VAR_DECL
12895 && DECL_PRETTY_FUNCTION_P (decl))
12897 /* For __PRETTY_FUNCTION__ we have to adjust the
12899 const char *const name
12900 = cxx_printable_name (current_function_decl, 2);
12901 init = cp_fname_init (name, &TREE_TYPE (decl));
12905 tree t = RECUR (init);
12909 /* If we had an initializer but it
12910 instantiated to nothing,
12911 value-initialize the object. This will
12912 only occur when the initializer was a
12913 pack expansion where the parameter packs
12914 used in that expansion were of length
12916 init = build_value_init (TREE_TYPE (decl),
12918 if (TREE_CODE (init) == AGGR_INIT_EXPR)
12919 init = get_target_expr_sfinae (init, complain);
12925 if (TREE_CODE (decl) == VAR_DECL)
12926 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
12928 cp_finish_decl (decl, init, const_init, NULL_TREE, 0);
12933 /* A DECL_EXPR can also be used as an expression, in the condition
12934 clause of an if/for/while construct. */
12939 stmt = begin_for_stmt (NULL_TREE, NULL_TREE);
12940 RECUR (FOR_INIT_STMT (t));
12941 finish_for_init_stmt (stmt);
12942 tmp = RECUR (FOR_COND (t));
12943 finish_for_cond (tmp, stmt);
12944 tmp = RECUR (FOR_EXPR (t));
12945 finish_for_expr (tmp, stmt);
12946 RECUR (FOR_BODY (t));
12947 finish_for_stmt (stmt);
12950 case RANGE_FOR_STMT:
12953 stmt = begin_for_stmt (NULL_TREE, NULL_TREE);
12954 decl = RANGE_FOR_DECL (t);
12955 decl = tsubst (decl, args, complain, in_decl);
12956 maybe_push_decl (decl);
12957 expr = RECUR (RANGE_FOR_EXPR (t));
12958 stmt = cp_convert_range_for (stmt, decl, expr);
12959 RECUR (RANGE_FOR_BODY (t));
12960 finish_for_stmt (stmt);
12965 stmt = begin_while_stmt ();
12966 tmp = RECUR (WHILE_COND (t));
12967 finish_while_stmt_cond (tmp, stmt);
12968 RECUR (WHILE_BODY (t));
12969 finish_while_stmt (stmt);
12973 stmt = begin_do_stmt ();
12974 RECUR (DO_BODY (t));
12975 finish_do_body (stmt);
12976 tmp = RECUR (DO_COND (t));
12977 finish_do_stmt (tmp, stmt);
12981 stmt = begin_if_stmt ();
12982 tmp = RECUR (IF_COND (t));
12983 finish_if_stmt_cond (tmp, stmt);
12984 RECUR (THEN_CLAUSE (t));
12985 finish_then_clause (stmt);
12987 if (ELSE_CLAUSE (t))
12989 begin_else_clause (stmt);
12990 RECUR (ELSE_CLAUSE (t));
12991 finish_else_clause (stmt);
12994 finish_if_stmt (stmt);
12998 if (BIND_EXPR_BODY_BLOCK (t))
12999 stmt = begin_function_body ();
13001 stmt = begin_compound_stmt (BIND_EXPR_TRY_BLOCK (t)
13002 ? BCS_TRY_BLOCK : 0);
13004 RECUR (BIND_EXPR_BODY (t));
13006 if (BIND_EXPR_BODY_BLOCK (t))
13007 finish_function_body (stmt);
13009 finish_compound_stmt (stmt);
13013 finish_break_stmt ();
13016 case CONTINUE_STMT:
13017 finish_continue_stmt ();
13021 stmt = begin_switch_stmt ();
13022 tmp = RECUR (SWITCH_STMT_COND (t));
13023 finish_switch_cond (tmp, stmt);
13024 RECUR (SWITCH_STMT_BODY (t));
13025 finish_switch_stmt (stmt);
13028 case CASE_LABEL_EXPR:
13029 finish_case_label (EXPR_LOCATION (t),
13030 RECUR (CASE_LOW (t)),
13031 RECUR (CASE_HIGH (t)));
13036 tree decl = LABEL_EXPR_LABEL (t);
13039 label = finish_label_stmt (DECL_NAME (decl));
13040 if (DECL_ATTRIBUTES (decl) != NULL_TREE)
13041 cplus_decl_attributes (&label, DECL_ATTRIBUTES (decl), 0);
13046 tmp = GOTO_DESTINATION (t);
13047 if (TREE_CODE (tmp) != LABEL_DECL)
13048 /* Computed goto's must be tsubst'd into. On the other hand,
13049 non-computed gotos must not be; the identifier in question
13050 will have no binding. */
13053 tmp = DECL_NAME (tmp);
13054 finish_goto_stmt (tmp);
13058 tmp = finish_asm_stmt
13059 (ASM_VOLATILE_P (t),
13060 RECUR (ASM_STRING (t)),
13061 tsubst_copy_asm_operands (ASM_OUTPUTS (t), args, complain, in_decl),
13062 tsubst_copy_asm_operands (ASM_INPUTS (t), args, complain, in_decl),
13063 tsubst_copy_asm_operands (ASM_CLOBBERS (t), args, complain, in_decl),
13064 tsubst_copy_asm_operands (ASM_LABELS (t), args, complain, in_decl));
13066 tree asm_expr = tmp;
13067 if (TREE_CODE (asm_expr) == CLEANUP_POINT_EXPR)
13068 asm_expr = TREE_OPERAND (asm_expr, 0);
13069 ASM_INPUT_P (asm_expr) = ASM_INPUT_P (t);
13076 stmt = begin_try_block ();
13077 RECUR (TRY_STMTS (t));
13078 finish_cleanup_try_block (stmt);
13079 finish_cleanup (RECUR (TRY_HANDLERS (t)), stmt);
13083 tree compound_stmt = NULL_TREE;
13085 if (FN_TRY_BLOCK_P (t))
13086 stmt = begin_function_try_block (&compound_stmt);
13088 stmt = begin_try_block ();
13090 RECUR (TRY_STMTS (t));
13092 if (FN_TRY_BLOCK_P (t))
13093 finish_function_try_block (stmt);
13095 finish_try_block (stmt);
13097 RECUR (TRY_HANDLERS (t));
13098 if (FN_TRY_BLOCK_P (t))
13099 finish_function_handler_sequence (stmt, compound_stmt);
13101 finish_handler_sequence (stmt);
13107 tree decl = HANDLER_PARMS (t);
13111 decl = tsubst (decl, args, complain, in_decl);
13112 /* Prevent instantiate_decl from trying to instantiate
13113 this variable. We've already done all that needs to be
13115 if (decl != error_mark_node)
13116 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
13118 stmt = begin_handler ();
13119 finish_handler_parms (decl, stmt);
13120 RECUR (HANDLER_BODY (t));
13121 finish_handler (stmt);
13126 tsubst (TREE_TYPE (t), args, complain, NULL_TREE);
13129 case STATIC_ASSERT:
13132 tsubst_expr (STATIC_ASSERT_CONDITION (t),
13135 /*integral_constant_expression_p=*/true);
13136 finish_static_assert (condition,
13137 STATIC_ASSERT_MESSAGE (t),
13138 STATIC_ASSERT_SOURCE_LOCATION (t),
13139 /*member_p=*/false);
13144 tmp = tsubst_omp_clauses (OMP_PARALLEL_CLAUSES (t),
13145 args, complain, in_decl);
13146 stmt = begin_omp_parallel ();
13147 RECUR (OMP_PARALLEL_BODY (t));
13148 OMP_PARALLEL_COMBINED (finish_omp_parallel (tmp, stmt))
13149 = OMP_PARALLEL_COMBINED (t);
13153 tmp = tsubst_omp_clauses (OMP_TASK_CLAUSES (t),
13154 args, complain, in_decl);
13155 stmt = begin_omp_task ();
13156 RECUR (OMP_TASK_BODY (t));
13157 finish_omp_task (tmp, stmt);
13162 tree clauses, body, pre_body;
13163 tree declv, initv, condv, incrv;
13166 clauses = tsubst_omp_clauses (OMP_FOR_CLAUSES (t),
13167 args, complain, in_decl);
13168 declv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
13169 initv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
13170 condv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
13171 incrv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
13173 for (i = 0; i < TREE_VEC_LENGTH (OMP_FOR_INIT (t)); i++)
13174 tsubst_omp_for_iterator (t, i, declv, initv, condv, incrv,
13175 &clauses, args, complain, in_decl,
13176 integral_constant_expression_p);
13178 stmt = begin_omp_structured_block ();
13180 for (i = 0; i < TREE_VEC_LENGTH (initv); i++)
13181 if (TREE_VEC_ELT (initv, i) == NULL
13182 || TREE_CODE (TREE_VEC_ELT (initv, i)) != DECL_EXPR)
13183 TREE_VEC_ELT (initv, i) = RECUR (TREE_VEC_ELT (initv, i));
13184 else if (CLASS_TYPE_P (TREE_TYPE (TREE_VEC_ELT (initv, i))))
13186 tree init = RECUR (TREE_VEC_ELT (initv, i));
13187 gcc_assert (init == TREE_VEC_ELT (declv, i));
13188 TREE_VEC_ELT (initv, i) = NULL_TREE;
13192 tree decl_expr = TREE_VEC_ELT (initv, i);
13193 tree init = DECL_INITIAL (DECL_EXPR_DECL (decl_expr));
13194 gcc_assert (init != NULL);
13195 TREE_VEC_ELT (initv, i) = RECUR (init);
13196 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = NULL;
13198 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = init;
13201 pre_body = push_stmt_list ();
13202 RECUR (OMP_FOR_PRE_BODY (t));
13203 pre_body = pop_stmt_list (pre_body);
13205 body = push_stmt_list ();
13206 RECUR (OMP_FOR_BODY (t));
13207 body = pop_stmt_list (body);
13209 t = finish_omp_for (EXPR_LOCATION (t), declv, initv, condv, incrv,
13210 body, pre_body, clauses);
13212 add_stmt (finish_omp_structured_block (stmt));
13218 tmp = tsubst_omp_clauses (OMP_CLAUSES (t), args, complain, in_decl);
13219 stmt = push_stmt_list ();
13220 RECUR (OMP_BODY (t));
13221 stmt = pop_stmt_list (stmt);
13224 OMP_BODY (t) = stmt;
13225 OMP_CLAUSES (t) = tmp;
13233 stmt = push_stmt_list ();
13234 RECUR (OMP_BODY (t));
13235 stmt = pop_stmt_list (stmt);
13238 OMP_BODY (t) = stmt;
13243 gcc_assert (OMP_ATOMIC_DEPENDENT_P (t));
13244 if (TREE_CODE (TREE_OPERAND (t, 1)) != MODIFY_EXPR)
13246 tree op1 = TREE_OPERAND (t, 1);
13247 tree rhs1 = NULL_TREE;
13249 if (TREE_CODE (op1) == COMPOUND_EXPR)
13251 rhs1 = RECUR (TREE_OPERAND (op1, 0));
13252 op1 = TREE_OPERAND (op1, 1);
13254 lhs = RECUR (TREE_OPERAND (op1, 0));
13255 rhs = RECUR (TREE_OPERAND (op1, 1));
13256 finish_omp_atomic (OMP_ATOMIC, TREE_CODE (op1), lhs, rhs,
13257 NULL_TREE, NULL_TREE, rhs1);
13261 tree op1 = TREE_OPERAND (t, 1);
13262 tree v = NULL_TREE, lhs, rhs = NULL_TREE, lhs1 = NULL_TREE;
13263 tree rhs1 = NULL_TREE;
13264 enum tree_code code = TREE_CODE (TREE_OPERAND (op1, 1));
13265 enum tree_code opcode = NOP_EXPR;
13266 if (code == OMP_ATOMIC_READ)
13268 v = RECUR (TREE_OPERAND (op1, 0));
13269 lhs = RECUR (TREE_OPERAND (TREE_OPERAND (op1, 1), 0));
13271 else if (code == OMP_ATOMIC_CAPTURE_OLD
13272 || code == OMP_ATOMIC_CAPTURE_NEW)
13274 tree op11 = TREE_OPERAND (TREE_OPERAND (op1, 1), 1);
13275 v = RECUR (TREE_OPERAND (op1, 0));
13276 lhs1 = RECUR (TREE_OPERAND (TREE_OPERAND (op1, 1), 0));
13277 if (TREE_CODE (op11) == COMPOUND_EXPR)
13279 rhs1 = RECUR (TREE_OPERAND (op11, 0));
13280 op11 = TREE_OPERAND (op11, 1);
13282 lhs = RECUR (TREE_OPERAND (op11, 0));
13283 rhs = RECUR (TREE_OPERAND (op11, 1));
13284 opcode = TREE_CODE (op11);
13289 lhs = RECUR (TREE_OPERAND (op1, 0));
13290 rhs = RECUR (TREE_OPERAND (op1, 1));
13292 finish_omp_atomic (code, opcode, lhs, rhs, v, lhs1, rhs1);
13296 case TRANSACTION_EXPR:
13299 flags |= (TRANSACTION_EXPR_OUTER (t) ? TM_STMT_ATTR_OUTER : 0);
13300 flags |= (TRANSACTION_EXPR_RELAXED (t) ? TM_STMT_ATTR_RELAXED : 0);
13302 if (TRANSACTION_EXPR_IS_STMT (t))
13304 tree body = TRANSACTION_EXPR_BODY (t);
13305 tree noex = NULL_TREE;
13306 if (TREE_CODE (body) == MUST_NOT_THROW_EXPR)
13308 noex = MUST_NOT_THROW_COND (body);
13309 if (noex == NULL_TREE)
13310 noex = boolean_true_node;
13311 body = TREE_OPERAND (body, 0);
13313 stmt = begin_transaction_stmt (input_location, NULL, flags);
13315 finish_transaction_stmt (stmt, NULL, flags, RECUR (noex));
13319 stmt = build_transaction_expr (EXPR_LOCATION (t),
13320 RECUR (TRANSACTION_EXPR_BODY (t)),
13327 case MUST_NOT_THROW_EXPR:
13328 return build_must_not_throw_expr (RECUR (TREE_OPERAND (t, 0)),
13329 RECUR (MUST_NOT_THROW_COND (t)));
13331 case EXPR_PACK_EXPANSION:
13332 error ("invalid use of pack expansion expression");
13333 return error_mark_node;
13335 case NONTYPE_ARGUMENT_PACK:
13336 error ("use %<...%> to expand argument pack");
13337 return error_mark_node;
13340 gcc_assert (!STATEMENT_CODE_P (TREE_CODE (t)));
13342 return tsubst_copy_and_build (t, args, complain, in_decl,
13343 /*function_p=*/false,
13344 integral_constant_expression_p);
13351 /* T is a postfix-expression that is not being used in a function
13352 call. Return the substituted version of T. */
13355 tsubst_non_call_postfix_expression (tree t, tree args,
13356 tsubst_flags_t complain,
13359 if (TREE_CODE (t) == SCOPE_REF)
13360 t = tsubst_qualified_id (t, args, complain, in_decl,
13361 /*done=*/false, /*address_p=*/false);
13363 t = tsubst_copy_and_build (t, args, complain, in_decl,
13364 /*function_p=*/false,
13365 /*integral_constant_expression_p=*/false);
13370 /* Like tsubst but deals with expressions and performs semantic
13371 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
13374 tsubst_copy_and_build (tree t,
13376 tsubst_flags_t complain,
13379 bool integral_constant_expression_p)
13381 #define RECUR(NODE) \
13382 tsubst_copy_and_build (NODE, args, complain, in_decl, \
13383 /*function_p=*/false, \
13384 integral_constant_expression_p)
13388 if (t == NULL_TREE || t == error_mark_node)
13391 switch (TREE_CODE (t))
13395 /* Fall through. */
13396 case IDENTIFIER_NODE:
13400 bool non_integral_constant_expression_p;
13401 const char *error_msg;
13403 if (IDENTIFIER_TYPENAME_P (t))
13405 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
13406 t = mangle_conv_op_name_for_type (new_type);
13409 /* Look up the name. */
13410 decl = lookup_name (t);
13412 /* By convention, expressions use ERROR_MARK_NODE to indicate
13413 failure, not NULL_TREE. */
13414 if (decl == NULL_TREE)
13415 decl = error_mark_node;
13417 decl = finish_id_expression (t, decl, NULL_TREE,
13419 integral_constant_expression_p,
13420 /*allow_non_integral_constant_expression_p=*/(cxx_dialect >= cxx0x),
13421 &non_integral_constant_expression_p,
13422 /*template_p=*/false,
13424 /*address_p=*/false,
13425 /*template_arg_p=*/false,
13430 if (!function_p && TREE_CODE (decl) == IDENTIFIER_NODE)
13432 if (complain & tf_error)
13433 unqualified_name_lookup_error (decl);
13434 decl = error_mark_node;
13439 case TEMPLATE_ID_EXPR:
13442 tree templ = RECUR (TREE_OPERAND (t, 0));
13443 tree targs = TREE_OPERAND (t, 1);
13446 targs = tsubst_template_args (targs, args, complain, in_decl);
13448 if (TREE_CODE (templ) == COMPONENT_REF)
13450 object = TREE_OPERAND (templ, 0);
13451 templ = TREE_OPERAND (templ, 1);
13454 object = NULL_TREE;
13455 templ = lookup_template_function (templ, targs);
13458 return build3 (COMPONENT_REF, TREE_TYPE (templ),
13459 object, templ, NULL_TREE);
13461 return baselink_for_fns (templ);
13466 tree r = RECUR (TREE_OPERAND (t, 0));
13468 if (REFERENCE_REF_P (t))
13470 /* A type conversion to reference type will be enclosed in
13471 such an indirect ref, but the substitution of the cast
13472 will have also added such an indirect ref. */
13473 if (TREE_CODE (TREE_TYPE (r)) == REFERENCE_TYPE)
13474 r = convert_from_reference (r);
13477 r = build_x_indirect_ref (r, RO_UNARY_STAR, complain);
13483 (tsubst (TREE_TYPE (t), args, complain, in_decl),
13484 RECUR (TREE_OPERAND (t, 0)));
13486 case IMPLICIT_CONV_EXPR:
13488 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
13489 tree expr = RECUR (TREE_OPERAND (t, 0));
13490 int flags = LOOKUP_IMPLICIT;
13491 if (IMPLICIT_CONV_EXPR_DIRECT_INIT (t))
13492 flags = LOOKUP_NORMAL;
13493 return perform_implicit_conversion_flags (type, expr, complain,
13500 tsubst (TREE_TYPE (t), args, complain, in_decl),
13501 RECUR (TREE_OPERAND (t, 0)));
13504 case REINTERPRET_CAST_EXPR:
13505 case CONST_CAST_EXPR:
13506 case DYNAMIC_CAST_EXPR:
13507 case STATIC_CAST_EXPR:
13512 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
13513 if (integral_constant_expression_p
13514 && !cast_valid_in_integral_constant_expression_p (type))
13516 if (complain & tf_error)
13517 error ("a cast to a type other than an integral or "
13518 "enumeration type cannot appear in a constant-expression");
13519 return error_mark_node;
13522 op = RECUR (TREE_OPERAND (t, 0));
13524 switch (TREE_CODE (t))
13527 return build_functional_cast (type, op, complain);
13528 case REINTERPRET_CAST_EXPR:
13529 return build_reinterpret_cast (type, op, complain);
13530 case CONST_CAST_EXPR:
13531 return build_const_cast (type, op, complain);
13532 case DYNAMIC_CAST_EXPR:
13533 return build_dynamic_cast (type, op, complain);
13534 case STATIC_CAST_EXPR:
13535 return build_static_cast (type, op, complain);
13537 gcc_unreachable ();
13541 case POSTDECREMENT_EXPR:
13542 case POSTINCREMENT_EXPR:
13543 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
13544 args, complain, in_decl);
13545 return build_x_unary_op (TREE_CODE (t), op1, complain);
13547 case PREDECREMENT_EXPR:
13548 case PREINCREMENT_EXPR:
13552 case TRUTH_NOT_EXPR:
13553 case UNARY_PLUS_EXPR: /* Unary + */
13554 case REALPART_EXPR:
13555 case IMAGPART_EXPR:
13556 return build_x_unary_op (TREE_CODE (t), RECUR (TREE_OPERAND (t, 0)),
13559 case FIX_TRUNC_EXPR:
13560 return cp_build_unary_op (FIX_TRUNC_EXPR, RECUR (TREE_OPERAND (t, 0)),
13564 op1 = TREE_OPERAND (t, 0);
13565 if (TREE_CODE (op1) == LABEL_DECL)
13566 return finish_label_address_expr (DECL_NAME (op1),
13567 EXPR_LOCATION (op1));
13568 if (TREE_CODE (op1) == SCOPE_REF)
13569 op1 = tsubst_qualified_id (op1, args, complain, in_decl,
13570 /*done=*/true, /*address_p=*/true);
13572 op1 = tsubst_non_call_postfix_expression (op1, args, complain,
13574 return build_x_unary_op (ADDR_EXPR, op1, complain);
13579 case TRUNC_DIV_EXPR:
13580 case CEIL_DIV_EXPR:
13581 case FLOOR_DIV_EXPR:
13582 case ROUND_DIV_EXPR:
13583 case EXACT_DIV_EXPR:
13587 case TRUNC_MOD_EXPR:
13588 case FLOOR_MOD_EXPR:
13589 case TRUTH_ANDIF_EXPR:
13590 case TRUTH_ORIF_EXPR:
13591 case TRUTH_AND_EXPR:
13592 case TRUTH_OR_EXPR:
13608 tree r = build_x_binary_op
13610 RECUR (TREE_OPERAND (t, 0)),
13611 (TREE_NO_WARNING (TREE_OPERAND (t, 0))
13613 : TREE_CODE (TREE_OPERAND (t, 0))),
13614 RECUR (TREE_OPERAND (t, 1)),
13615 (TREE_NO_WARNING (TREE_OPERAND (t, 1))
13617 : TREE_CODE (TREE_OPERAND (t, 1))),
13620 if (EXPR_P (r) && TREE_NO_WARNING (t))
13621 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
13626 return tsubst_qualified_id (t, args, complain, in_decl, /*done=*/true,
13627 /*address_p=*/false);
13629 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
13630 args, complain, in_decl);
13631 return build_x_array_ref (op1, RECUR (TREE_OPERAND (t, 1)), complain);
13634 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
13635 return tsubst_copy (t, args, complain, in_decl);
13639 op1 = TREE_OPERAND (t, 0);
13642 /* When there are no ARGS, we are trying to evaluate a
13643 non-dependent expression from the parser. Trying to do
13644 the substitutions may not work. */
13646 op1 = TREE_TYPE (op1);
13650 ++cp_unevaluated_operand;
13651 ++c_inhibit_evaluation_warnings;
13652 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
13653 /*function_p=*/false,
13654 /*integral_constant_expression_p=*/false);
13655 --cp_unevaluated_operand;
13656 --c_inhibit_evaluation_warnings;
13659 return cxx_sizeof_or_alignof_type (op1, TREE_CODE (t),
13660 complain & tf_error);
13662 return cxx_sizeof_or_alignof_expr (op1, TREE_CODE (t),
13663 complain & tf_error);
13665 case AT_ENCODE_EXPR:
13667 op1 = TREE_OPERAND (t, 0);
13668 ++cp_unevaluated_operand;
13669 ++c_inhibit_evaluation_warnings;
13670 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
13671 /*function_p=*/false,
13672 /*integral_constant_expression_p=*/false);
13673 --cp_unevaluated_operand;
13674 --c_inhibit_evaluation_warnings;
13675 return objc_build_encode_expr (op1);
13678 case NOEXCEPT_EXPR:
13679 op1 = TREE_OPERAND (t, 0);
13680 ++cp_unevaluated_operand;
13681 ++c_inhibit_evaluation_warnings;
13682 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
13683 /*function_p=*/false,
13684 /*integral_constant_expression_p=*/false);
13685 --cp_unevaluated_operand;
13686 --c_inhibit_evaluation_warnings;
13687 return finish_noexcept_expr (op1, complain);
13691 tree r = build_x_modify_expr
13692 (RECUR (TREE_OPERAND (t, 0)),
13693 TREE_CODE (TREE_OPERAND (t, 1)),
13694 RECUR (TREE_OPERAND (t, 2)),
13696 /* TREE_NO_WARNING must be set if either the expression was
13697 parenthesized or it uses an operator such as >>= rather
13698 than plain assignment. In the former case, it was already
13699 set and must be copied. In the latter case,
13700 build_x_modify_expr sets it and it must not be reset
13702 if (TREE_NO_WARNING (t))
13703 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
13708 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
13709 args, complain, in_decl);
13710 /* Remember that there was a reference to this entity. */
13713 return build_x_arrow (op1);
13717 tree placement = RECUR (TREE_OPERAND (t, 0));
13718 tree init = RECUR (TREE_OPERAND (t, 3));
13719 VEC(tree,gc) *placement_vec;
13720 VEC(tree,gc) *init_vec;
13723 if (placement == NULL_TREE)
13724 placement_vec = NULL;
13727 placement_vec = make_tree_vector ();
13728 for (; placement != NULL_TREE; placement = TREE_CHAIN (placement))
13729 VEC_safe_push (tree, gc, placement_vec, TREE_VALUE (placement));
13732 /* If there was an initializer in the original tree, but it
13733 instantiated to an empty list, then we should pass a
13734 non-NULL empty vector to tell build_new that it was an
13735 empty initializer() rather than no initializer. This can
13736 only happen when the initializer is a pack expansion whose
13737 parameter packs are of length zero. */
13738 if (init == NULL_TREE && TREE_OPERAND (t, 3) == NULL_TREE)
13742 init_vec = make_tree_vector ();
13743 if (init == void_zero_node)
13744 gcc_assert (init_vec != NULL);
13747 for (; init != NULL_TREE; init = TREE_CHAIN (init))
13748 VEC_safe_push (tree, gc, init_vec, TREE_VALUE (init));
13752 ret = build_new (&placement_vec,
13753 tsubst (TREE_OPERAND (t, 1), args, complain, in_decl),
13754 RECUR (TREE_OPERAND (t, 2)),
13756 NEW_EXPR_USE_GLOBAL (t),
13759 if (placement_vec != NULL)
13760 release_tree_vector (placement_vec);
13761 if (init_vec != NULL)
13762 release_tree_vector (init_vec);
13768 return delete_sanity
13769 (RECUR (TREE_OPERAND (t, 0)),
13770 RECUR (TREE_OPERAND (t, 1)),
13771 DELETE_EXPR_USE_VEC (t),
13772 DELETE_EXPR_USE_GLOBAL (t),
13775 case COMPOUND_EXPR:
13776 return build_x_compound_expr (RECUR (TREE_OPERAND (t, 0)),
13777 RECUR (TREE_OPERAND (t, 1)),
13783 VEC(tree,gc) *call_args;
13784 unsigned int nargs, i;
13789 function = CALL_EXPR_FN (t);
13790 /* When we parsed the expression, we determined whether or
13791 not Koenig lookup should be performed. */
13792 koenig_p = KOENIG_LOOKUP_P (t);
13793 if (TREE_CODE (function) == SCOPE_REF)
13795 qualified_p = true;
13796 function = tsubst_qualified_id (function, args, complain, in_decl,
13798 /*address_p=*/false);
13800 else if (koenig_p && TREE_CODE (function) == IDENTIFIER_NODE)
13802 /* Do nothing; calling tsubst_copy_and_build on an identifier
13803 would incorrectly perform unqualified lookup again.
13805 Note that we can also have an IDENTIFIER_NODE if the earlier
13806 unqualified lookup found a member function; in that case
13807 koenig_p will be false and we do want to do the lookup
13808 again to find the instantiated member function.
13810 FIXME but doing that causes c++/15272, so we need to stop
13811 using IDENTIFIER_NODE in that situation. */
13812 qualified_p = false;
13816 if (TREE_CODE (function) == COMPONENT_REF)
13818 tree op = TREE_OPERAND (function, 1);
13820 qualified_p = (TREE_CODE (op) == SCOPE_REF
13821 || (BASELINK_P (op)
13822 && BASELINK_QUALIFIED_P (op)));
13825 qualified_p = false;
13827 function = tsubst_copy_and_build (function, args, complain,
13830 integral_constant_expression_p);
13832 if (BASELINK_P (function))
13833 qualified_p = true;
13836 nargs = call_expr_nargs (t);
13837 call_args = make_tree_vector ();
13838 for (i = 0; i < nargs; ++i)
13840 tree arg = CALL_EXPR_ARG (t, i);
13842 if (!PACK_EXPANSION_P (arg))
13843 VEC_safe_push (tree, gc, call_args,
13844 RECUR (CALL_EXPR_ARG (t, i)));
13847 /* Expand the pack expansion and push each entry onto
13849 arg = tsubst_pack_expansion (arg, args, complain, in_decl);
13850 if (TREE_CODE (arg) == TREE_VEC)
13852 unsigned int len, j;
13854 len = TREE_VEC_LENGTH (arg);
13855 for (j = 0; j < len; ++j)
13857 tree value = TREE_VEC_ELT (arg, j);
13858 if (value != NULL_TREE)
13859 value = convert_from_reference (value);
13860 VEC_safe_push (tree, gc, call_args, value);
13865 /* A partial substitution. Add one entry. */
13866 VEC_safe_push (tree, gc, call_args, arg);
13871 /* We do not perform argument-dependent lookup if normal
13872 lookup finds a non-function, in accordance with the
13873 expected resolution of DR 218. */
13875 && ((is_overloaded_fn (function)
13876 /* If lookup found a member function, the Koenig lookup is
13877 not appropriate, even if an unqualified-name was used
13878 to denote the function. */
13879 && !DECL_FUNCTION_MEMBER_P (get_first_fn (function)))
13880 || TREE_CODE (function) == IDENTIFIER_NODE)
13881 /* Only do this when substitution turns a dependent call
13882 into a non-dependent call. */
13883 && type_dependent_expression_p_push (t)
13884 && !any_type_dependent_arguments_p (call_args))
13885 function = perform_koenig_lookup (function, call_args, false,
13888 if (TREE_CODE (function) == IDENTIFIER_NODE
13889 && !any_type_dependent_arguments_p (call_args))
13891 if (koenig_p && (complain & tf_warning_or_error))
13893 /* For backwards compatibility and good diagnostics, try
13894 the unqualified lookup again if we aren't in SFINAE
13896 tree unq = (tsubst_copy_and_build
13897 (function, args, complain, in_decl, true,
13898 integral_constant_expression_p));
13899 if (unq == error_mark_node)
13900 return error_mark_node;
13902 if (unq != function)
13905 if (TREE_CODE (fn) == INDIRECT_REF)
13906 fn = TREE_OPERAND (fn, 0);
13907 if (TREE_CODE (fn) == COMPONENT_REF)
13908 fn = TREE_OPERAND (fn, 1);
13909 if (is_overloaded_fn (fn))
13910 fn = get_first_fn (fn);
13911 permerror (EXPR_LOC_OR_HERE (t),
13912 "%qD was not declared in this scope, "
13913 "and no declarations were found by "
13914 "argument-dependent lookup at the point "
13915 "of instantiation", function);
13917 /* Can't say anything more. */;
13918 else if (DECL_CLASS_SCOPE_P (fn))
13920 inform (EXPR_LOC_OR_HERE (t),
13921 "declarations in dependent base %qT are "
13922 "not found by unqualified lookup",
13923 DECL_CLASS_CONTEXT (fn));
13924 if (current_class_ptr)
13925 inform (EXPR_LOC_OR_HERE (t),
13926 "use %<this->%D%> instead", function);
13928 inform (EXPR_LOC_OR_HERE (t),
13929 "use %<%T::%D%> instead",
13930 current_class_name, function);
13933 inform (0, "%q+D declared here, later in the "
13934 "translation unit", fn);
13938 if (TREE_CODE (function) == IDENTIFIER_NODE)
13940 unqualified_name_lookup_error (function);
13941 release_tree_vector (call_args);
13942 return error_mark_node;
13946 /* Remember that there was a reference to this entity. */
13947 if (DECL_P (function))
13948 mark_used (function);
13950 if (TREE_CODE (function) == OFFSET_REF)
13951 ret = build_offset_ref_call_from_tree (function, &call_args);
13952 else if (TREE_CODE (function) == COMPONENT_REF)
13954 tree instance = TREE_OPERAND (function, 0);
13955 tree fn = TREE_OPERAND (function, 1);
13957 if (processing_template_decl
13958 && (type_dependent_expression_p (instance)
13959 || (!BASELINK_P (fn)
13960 && TREE_CODE (fn) != FIELD_DECL)
13961 || type_dependent_expression_p (fn)
13962 || any_type_dependent_arguments_p (call_args)))
13963 ret = build_nt_call_vec (function, call_args);
13964 else if (!BASELINK_P (fn))
13965 ret = finish_call_expr (function, &call_args,
13966 /*disallow_virtual=*/false,
13967 /*koenig_p=*/false,
13970 ret = (build_new_method_call
13972 &call_args, NULL_TREE,
13973 qualified_p ? LOOKUP_NONVIRTUAL : LOOKUP_NORMAL,
13978 ret = finish_call_expr (function, &call_args,
13979 /*disallow_virtual=*/qualified_p,
13983 release_tree_vector (call_args);
13989 return build_x_conditional_expr
13990 (RECUR (TREE_OPERAND (t, 0)),
13991 RECUR (TREE_OPERAND (t, 1)),
13992 RECUR (TREE_OPERAND (t, 2)),
13995 case PSEUDO_DTOR_EXPR:
13996 return finish_pseudo_destructor_expr
13997 (RECUR (TREE_OPERAND (t, 0)),
13998 RECUR (TREE_OPERAND (t, 1)),
13999 tsubst (TREE_OPERAND (t, 2), args, complain, in_decl));
14003 tree purpose, value, chain;
14005 if (t == void_list_node)
14008 if ((TREE_PURPOSE (t) && PACK_EXPANSION_P (TREE_PURPOSE (t)))
14009 || (TREE_VALUE (t) && PACK_EXPANSION_P (TREE_VALUE (t))))
14011 /* We have pack expansions, so expand those and
14012 create a new list out of it. */
14013 tree purposevec = NULL_TREE;
14014 tree valuevec = NULL_TREE;
14018 /* Expand the argument expressions. */
14019 if (TREE_PURPOSE (t))
14020 purposevec = tsubst_pack_expansion (TREE_PURPOSE (t), args,
14021 complain, in_decl);
14022 if (TREE_VALUE (t))
14023 valuevec = tsubst_pack_expansion (TREE_VALUE (t), args,
14024 complain, in_decl);
14026 /* Build the rest of the list. */
14027 chain = TREE_CHAIN (t);
14028 if (chain && chain != void_type_node)
14029 chain = RECUR (chain);
14031 /* Determine the number of arguments. */
14032 if (purposevec && TREE_CODE (purposevec) == TREE_VEC)
14034 len = TREE_VEC_LENGTH (purposevec);
14035 gcc_assert (!valuevec || len == TREE_VEC_LENGTH (valuevec));
14037 else if (TREE_CODE (valuevec) == TREE_VEC)
14038 len = TREE_VEC_LENGTH (valuevec);
14041 /* Since we only performed a partial substitution into
14042 the argument pack, we only return a single list
14044 if (purposevec == TREE_PURPOSE (t)
14045 && valuevec == TREE_VALUE (t)
14046 && chain == TREE_CHAIN (t))
14049 return tree_cons (purposevec, valuevec, chain);
14052 /* Convert the argument vectors into a TREE_LIST */
14056 /* Grab the Ith values. */
14058 purpose = purposevec ? TREE_VEC_ELT (purposevec, i)
14061 = valuevec ? convert_from_reference (TREE_VEC_ELT (valuevec, i))
14064 /* Build the list (backwards). */
14065 chain = tree_cons (purpose, value, chain);
14071 purpose = TREE_PURPOSE (t);
14073 purpose = RECUR (purpose);
14074 value = TREE_VALUE (t);
14076 value = RECUR (value);
14077 chain = TREE_CHAIN (t);
14078 if (chain && chain != void_type_node)
14079 chain = RECUR (chain);
14080 if (purpose == TREE_PURPOSE (t)
14081 && value == TREE_VALUE (t)
14082 && chain == TREE_CHAIN (t))
14084 return tree_cons (purpose, value, chain);
14087 case COMPONENT_REF:
14093 object = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
14094 args, complain, in_decl);
14095 /* Remember that there was a reference to this entity. */
14096 if (DECL_P (object))
14097 mark_used (object);
14098 object_type = TREE_TYPE (object);
14100 member = TREE_OPERAND (t, 1);
14101 if (BASELINK_P (member))
14102 member = tsubst_baselink (member,
14103 non_reference (TREE_TYPE (object)),
14104 args, complain, in_decl);
14106 member = tsubst_copy (member, args, complain, in_decl);
14107 if (member == error_mark_node)
14108 return error_mark_node;
14110 if (type_dependent_expression_p (object))
14111 /* We can't do much here. */;
14112 else if (!CLASS_TYPE_P (object_type))
14114 if (SCALAR_TYPE_P (object_type))
14116 tree s = NULL_TREE;
14117 tree dtor = member;
14119 if (TREE_CODE (dtor) == SCOPE_REF)
14121 s = TREE_OPERAND (dtor, 0);
14122 dtor = TREE_OPERAND (dtor, 1);
14124 if (TREE_CODE (dtor) == BIT_NOT_EXPR)
14126 dtor = TREE_OPERAND (dtor, 0);
14128 return finish_pseudo_destructor_expr (object, s, dtor);
14132 else if (TREE_CODE (member) == SCOPE_REF
14133 && TREE_CODE (TREE_OPERAND (member, 1)) == TEMPLATE_ID_EXPR)
14135 /* Lookup the template functions now that we know what the
14137 tree scope = TREE_OPERAND (member, 0);
14138 tree tmpl = TREE_OPERAND (TREE_OPERAND (member, 1), 0);
14139 tree args = TREE_OPERAND (TREE_OPERAND (member, 1), 1);
14140 member = lookup_qualified_name (scope, tmpl,
14141 /*is_type_p=*/false,
14142 /*complain=*/false);
14143 if (BASELINK_P (member))
14145 BASELINK_FUNCTIONS (member)
14146 = build_nt (TEMPLATE_ID_EXPR, BASELINK_FUNCTIONS (member),
14148 member = (adjust_result_of_qualified_name_lookup
14149 (member, BINFO_TYPE (BASELINK_BINFO (member)),
14154 qualified_name_lookup_error (scope, tmpl, member,
14156 return error_mark_node;
14159 else if (TREE_CODE (member) == SCOPE_REF
14160 && !CLASS_TYPE_P (TREE_OPERAND (member, 0))
14161 && TREE_CODE (TREE_OPERAND (member, 0)) != NAMESPACE_DECL)
14163 if (complain & tf_error)
14165 if (TYPE_P (TREE_OPERAND (member, 0)))
14166 error ("%qT is not a class or namespace",
14167 TREE_OPERAND (member, 0));
14169 error ("%qD is not a class or namespace",
14170 TREE_OPERAND (member, 0));
14172 return error_mark_node;
14174 else if (TREE_CODE (member) == FIELD_DECL)
14175 return finish_non_static_data_member (member, object, NULL_TREE);
14177 return finish_class_member_access_expr (object, member,
14178 /*template_p=*/false,
14184 (RECUR (TREE_OPERAND (t, 0)));
14188 VEC(constructor_elt,gc) *n;
14189 constructor_elt *ce;
14190 unsigned HOST_WIDE_INT idx;
14191 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
14192 bool process_index_p;
14194 bool need_copy_p = false;
14197 if (type == error_mark_node)
14198 return error_mark_node;
14200 /* digest_init will do the wrong thing if we let it. */
14201 if (type && TYPE_PTRMEMFUNC_P (type))
14204 /* We do not want to process the index of aggregate
14205 initializers as they are identifier nodes which will be
14206 looked up by digest_init. */
14207 process_index_p = !(type && MAYBE_CLASS_TYPE_P (type));
14209 n = VEC_copy (constructor_elt, gc, CONSTRUCTOR_ELTS (t));
14210 newlen = VEC_length (constructor_elt, n);
14211 FOR_EACH_VEC_ELT (constructor_elt, n, idx, ce)
14213 if (ce->index && process_index_p)
14214 ce->index = RECUR (ce->index);
14216 if (PACK_EXPANSION_P (ce->value))
14218 /* Substitute into the pack expansion. */
14219 ce->value = tsubst_pack_expansion (ce->value, args, complain,
14222 if (ce->value == error_mark_node
14223 || PACK_EXPANSION_P (ce->value))
14225 else if (TREE_VEC_LENGTH (ce->value) == 1)
14226 /* Just move the argument into place. */
14227 ce->value = TREE_VEC_ELT (ce->value, 0);
14230 /* Update the length of the final CONSTRUCTOR
14231 arguments vector, and note that we will need to
14233 newlen = newlen + TREE_VEC_LENGTH (ce->value) - 1;
14234 need_copy_p = true;
14238 ce->value = RECUR (ce->value);
14243 VEC(constructor_elt,gc) *old_n = n;
14245 n = VEC_alloc (constructor_elt, gc, newlen);
14246 FOR_EACH_VEC_ELT (constructor_elt, old_n, idx, ce)
14248 if (TREE_CODE (ce->value) == TREE_VEC)
14250 int i, len = TREE_VEC_LENGTH (ce->value);
14251 for (i = 0; i < len; ++i)
14252 CONSTRUCTOR_APPEND_ELT (n, 0,
14253 TREE_VEC_ELT (ce->value, i));
14256 CONSTRUCTOR_APPEND_ELT (n, 0, ce->value);
14260 r = build_constructor (init_list_type_node, n);
14261 CONSTRUCTOR_IS_DIRECT_INIT (r) = CONSTRUCTOR_IS_DIRECT_INIT (t);
14263 if (TREE_HAS_CONSTRUCTOR (t))
14264 return finish_compound_literal (type, r, complain);
14266 TREE_TYPE (r) = type;
14272 tree operand_0 = TREE_OPERAND (t, 0);
14273 if (TYPE_P (operand_0))
14275 operand_0 = tsubst (operand_0, args, complain, in_decl);
14276 return get_typeid (operand_0);
14280 operand_0 = RECUR (operand_0);
14281 return build_typeid (operand_0);
14292 tree r = tsubst_copy (t, args, complain, in_decl);
14294 if (TREE_CODE (TREE_TYPE (t)) != REFERENCE_TYPE)
14295 /* If the original type was a reference, we'll be wrapped in
14296 the appropriate INDIRECT_REF. */
14297 r = convert_from_reference (r);
14302 return build_x_va_arg (RECUR (TREE_OPERAND (t, 0)),
14303 tsubst (TREE_TYPE (t), args, complain, in_decl));
14305 case OFFSETOF_EXPR:
14306 return finish_offsetof (RECUR (TREE_OPERAND (t, 0)));
14310 tree type1 = tsubst_copy (TRAIT_EXPR_TYPE1 (t), args,
14311 complain, in_decl);
14313 tree type2 = TRAIT_EXPR_TYPE2 (t);
14315 type2 = tsubst_copy (type2, args, complain, in_decl);
14317 return finish_trait_expr (TRAIT_EXPR_KIND (t), type1, type2);
14322 tree old_stmt_expr = cur_stmt_expr;
14323 tree stmt_expr = begin_stmt_expr ();
14325 cur_stmt_expr = stmt_expr;
14326 tsubst_expr (STMT_EXPR_STMT (t), args, complain, in_decl,
14327 integral_constant_expression_p);
14328 stmt_expr = finish_stmt_expr (stmt_expr, false);
14329 cur_stmt_expr = old_stmt_expr;
14331 /* If the resulting list of expression statement is empty,
14332 fold it further into void_zero_node. */
14333 if (empty_expr_stmt_p (stmt_expr))
14334 stmt_expr = void_zero_node;
14340 t = tsubst_copy (t, args, complain, in_decl);
14341 /* As in finish_id_expression, we resolve enumeration constants
14342 to their underlying values. */
14343 if (TREE_CODE (t) == CONST_DECL && !processing_template_decl)
14345 used_types_insert (TREE_TYPE (t));
14346 return DECL_INITIAL (t);
14352 tree r = build_lambda_expr ();
14354 tree type = tsubst (LAMBDA_EXPR_CLOSURE (t), args, complain, NULL_TREE);
14355 LAMBDA_EXPR_CLOSURE (r) = type;
14356 CLASSTYPE_LAMBDA_EXPR (type) = r;
14358 LAMBDA_EXPR_LOCATION (r)
14359 = LAMBDA_EXPR_LOCATION (t);
14360 LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (r)
14361 = LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (t);
14362 LAMBDA_EXPR_MUTABLE_P (r) = LAMBDA_EXPR_MUTABLE_P (t);
14363 LAMBDA_EXPR_DISCRIMINATOR (r)
14364 = (LAMBDA_EXPR_DISCRIMINATOR (t));
14365 LAMBDA_EXPR_EXTRA_SCOPE (r)
14366 = RECUR (LAMBDA_EXPR_EXTRA_SCOPE (t));
14367 if (LAMBDA_EXPR_RETURN_TYPE (t) == dependent_lambda_return_type_node)
14369 LAMBDA_EXPR_RETURN_TYPE (r) = dependent_lambda_return_type_node;
14370 LAMBDA_EXPR_DEDUCE_RETURN_TYPE_P (r) = true;
14373 LAMBDA_EXPR_RETURN_TYPE (r)
14374 = tsubst (LAMBDA_EXPR_RETURN_TYPE (t), args, complain, in_decl);
14376 gcc_assert (LAMBDA_EXPR_THIS_CAPTURE (t) == NULL_TREE
14377 && LAMBDA_EXPR_PENDING_PROXIES (t) == NULL);
14379 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
14380 determine_visibility (TYPE_NAME (type));
14381 /* Now that we know visibility, instantiate the type so we have a
14382 declaration of the op() for later calls to lambda_function. */
14383 complete_type (type);
14385 /* The capture list refers to closure members, so this needs to
14386 wait until after we finish instantiating the type. */
14387 LAMBDA_EXPR_CAPTURE_LIST (r)
14388 = RECUR (LAMBDA_EXPR_CAPTURE_LIST (t));
14390 return build_lambda_object (r);
14394 /* We can get here for a constant initializer of non-dependent type.
14395 FIXME stop folding in cp_parser_initializer_clause. */
14396 gcc_assert (TREE_CONSTANT (t));
14398 tree r = get_target_expr (RECUR (TARGET_EXPR_INITIAL (t)));
14399 TREE_CONSTANT (r) = true;
14403 case TRANSACTION_EXPR:
14404 return tsubst_expr(t, args, complain, in_decl,
14405 integral_constant_expression_p);
14408 /* Handle Objective-C++ constructs, if appropriate. */
14411 = objcp_tsubst_copy_and_build (t, args, complain,
14412 in_decl, /*function_p=*/false);
14416 return tsubst_copy (t, args, complain, in_decl);
14422 /* Verify that the instantiated ARGS are valid. For type arguments,
14423 make sure that the type's linkage is ok. For non-type arguments,
14424 make sure they are constants if they are integral or enumerations.
14425 Emit an error under control of COMPLAIN, and return TRUE on error. */
14428 check_instantiated_arg (tree tmpl, tree t, tsubst_flags_t complain)
14430 if (ARGUMENT_PACK_P (t))
14432 tree vec = ARGUMENT_PACK_ARGS (t);
14433 int len = TREE_VEC_LENGTH (vec);
14434 bool result = false;
14437 for (i = 0; i < len; ++i)
14438 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (vec, i), complain))
14442 else if (TYPE_P (t))
14444 /* [basic.link]: A name with no linkage (notably, the name
14445 of a class or enumeration declared in a local scope)
14446 shall not be used to declare an entity with linkage.
14447 This implies that names with no linkage cannot be used as
14450 DR 757 relaxes this restriction for C++0x. */
14451 tree nt = (cxx_dialect > cxx98 ? NULL_TREE
14452 : no_linkage_check (t, /*relaxed_p=*/false));
14456 /* DR 488 makes use of a type with no linkage cause
14457 type deduction to fail. */
14458 if (complain & tf_error)
14460 if (TYPE_ANONYMOUS_P (nt))
14461 error ("%qT is/uses anonymous type", t);
14463 error ("template argument for %qD uses local type %qT",
14468 /* In order to avoid all sorts of complications, we do not
14469 allow variably-modified types as template arguments. */
14470 else if (variably_modified_type_p (t, NULL_TREE))
14472 if (complain & tf_error)
14473 error ("%qT is a variably modified type", t);
14477 /* A non-type argument of integral or enumerated type must be a
14479 else if (TREE_TYPE (t)
14480 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t))
14481 && !TREE_CONSTANT (t))
14483 if (complain & tf_error)
14484 error ("integral expression %qE is not constant", t);
14491 check_instantiated_args (tree tmpl, tree args, tsubst_flags_t complain)
14493 int ix, len = DECL_NTPARMS (tmpl);
14494 bool result = false;
14496 for (ix = 0; ix != len; ix++)
14498 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (args, ix), complain))
14501 if (result && (complain & tf_error))
14502 error (" trying to instantiate %qD", tmpl);
14506 /* In C++0x, it's possible to have a function template whose type depends
14507 on itself recursively. This is most obvious with decltype, but can also
14508 occur with enumeration scope (c++/48969). So we need to catch infinite
14509 recursion and reject the substitution at deduction time; this function
14510 will return error_mark_node for any repeated substitution.
14512 This also catches excessive recursion such as when f<N> depends on
14513 f<N-1> across all integers, and returns error_mark_node for all the
14514 substitutions back up to the initial one.
14516 This is, of course, not reentrant. */
14519 deduction_tsubst_fntype (tree fn, tree targs, tsubst_flags_t complain)
14521 static bool excessive_deduction_depth;
14522 static int deduction_depth;
14523 struct pending_template *old_last_pend = last_pending_template;
14524 struct tinst_level *old_error_tinst = last_error_tinst_level;
14526 tree fntype = TREE_TYPE (fn);
14530 if (excessive_deduction_depth)
14531 return error_mark_node;
14533 tinst = build_tree_list (fn, targs);
14534 if (!push_tinst_level (tinst))
14536 excessive_deduction_depth = true;
14538 return error_mark_node;
14541 input_location = DECL_SOURCE_LOCATION (fn);
14543 push_deduction_access_scope (fn);
14544 r = tsubst (fntype, targs, complain, NULL_TREE);
14545 pop_deduction_access_scope (fn);
14548 if (excessive_deduction_depth)
14550 r = error_mark_node;
14551 if (deduction_depth == 0)
14552 /* Reset once we're all the way out. */
14553 excessive_deduction_depth = false;
14556 pop_tinst_level ();
14557 /* We can't free this if a pending_template entry or last_error_tinst_level
14558 is pointing at it. */
14559 if (last_pending_template == old_last_pend
14560 && last_error_tinst_level == old_error_tinst)
14565 /* Instantiate the indicated variable or function template TMPL with
14566 the template arguments in TARG_PTR. */
14569 instantiate_template_1 (tree tmpl, tree orig_args, tsubst_flags_t complain)
14571 tree targ_ptr = orig_args;
14576 if (tmpl == error_mark_node)
14577 return error_mark_node;
14579 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
14581 /* If this function is a clone, handle it specially. */
14582 if (DECL_CLONED_FUNCTION_P (tmpl))
14587 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
14588 DECL_CLONED_FUNCTION. */
14589 spec = instantiate_template (DECL_ABSTRACT_ORIGIN (tmpl),
14590 targ_ptr, complain);
14591 if (spec == error_mark_node)
14592 return error_mark_node;
14594 /* Look for the clone. */
14595 FOR_EACH_CLONE (clone, spec)
14596 if (DECL_NAME (clone) == DECL_NAME (tmpl))
14598 /* We should always have found the clone by now. */
14599 gcc_unreachable ();
14603 /* Check to see if we already have this specialization. */
14604 gen_tmpl = most_general_template (tmpl);
14605 if (tmpl != gen_tmpl)
14606 /* The TMPL is a partial instantiation. To get a full set of
14607 arguments we must add the arguments used to perform the
14608 partial instantiation. */
14609 targ_ptr = add_outermost_template_args (DECL_TI_ARGS (tmpl),
14612 /* It would be nice to avoid hashing here and then again in tsubst_decl,
14613 but it doesn't seem to be on the hot path. */
14614 spec = retrieve_specialization (gen_tmpl, targ_ptr, 0);
14616 gcc_assert (tmpl == gen_tmpl
14617 || ((fndecl = retrieve_specialization (tmpl, orig_args, 0))
14619 || fndecl == NULL_TREE);
14621 if (spec != NULL_TREE)
14624 if (check_instantiated_args (gen_tmpl, INNERMOST_TEMPLATE_ARGS (targ_ptr),
14626 return error_mark_node;
14628 /* We are building a FUNCTION_DECL, during which the access of its
14629 parameters and return types have to be checked. However this
14630 FUNCTION_DECL which is the desired context for access checking
14631 is not built yet. We solve this chicken-and-egg problem by
14632 deferring all checks until we have the FUNCTION_DECL. */
14633 push_deferring_access_checks (dk_deferred);
14635 /* Instantiation of the function happens in the context of the function
14636 template, not the context of the overload resolution we're doing. */
14637 push_to_top_level ();
14638 if (DECL_CLASS_SCOPE_P (gen_tmpl))
14640 tree ctx = tsubst (DECL_CONTEXT (gen_tmpl), targ_ptr,
14641 complain, gen_tmpl);
14642 push_nested_class (ctx);
14644 /* Substitute template parameters to obtain the specialization. */
14645 fndecl = tsubst (DECL_TEMPLATE_RESULT (gen_tmpl),
14646 targ_ptr, complain, gen_tmpl);
14647 if (DECL_CLASS_SCOPE_P (gen_tmpl))
14648 pop_nested_class ();
14649 pop_from_top_level ();
14651 if (fndecl == error_mark_node)
14652 return error_mark_node;
14654 /* Now we know the specialization, compute access previously
14656 push_access_scope (fndecl);
14658 /* Some typedefs referenced from within the template code need to be access
14659 checked at template instantiation time, i.e now. These types were
14660 added to the template at parsing time. Let's get those and perfom
14661 the acces checks then. */
14662 perform_typedefs_access_check (DECL_TEMPLATE_RESULT (tmpl), targ_ptr);
14663 perform_deferred_access_checks ();
14664 pop_access_scope (fndecl);
14665 pop_deferring_access_checks ();
14667 /* The DECL_TI_TEMPLATE should always be the immediate parent
14668 template, not the most general template. */
14669 DECL_TI_TEMPLATE (fndecl) = tmpl;
14671 /* If we've just instantiated the main entry point for a function,
14672 instantiate all the alternate entry points as well. We do this
14673 by cloning the instantiation of the main entry point, not by
14674 instantiating the template clones. */
14675 if (DECL_CHAIN (gen_tmpl) && DECL_CLONED_FUNCTION_P (DECL_CHAIN (gen_tmpl)))
14676 clone_function_decl (fndecl, /*update_method_vec_p=*/0);
14681 /* Wrapper for instantiate_template_1. */
14684 instantiate_template (tree tmpl, tree orig_args, tsubst_flags_t complain)
14687 timevar_push (TV_TEMPLATE_INST);
14688 ret = instantiate_template_1 (tmpl, orig_args, complain);
14689 timevar_pop (TV_TEMPLATE_INST);
14693 /* We're going to do deduction substitution on the type of TMPL, a function
14694 template. In C++11 mode, push into that access scope. In C++03 mode,
14695 disable access checking. */
14698 push_deduction_access_scope (tree tmpl)
14700 if (cxx_dialect >= cxx0x)
14702 int ptd = processing_template_decl;
14703 push_access_scope (DECL_TEMPLATE_RESULT (tmpl));
14704 /* Preserve processing_template_decl across push_to_top_level. */
14705 if (ptd && !processing_template_decl)
14706 ++processing_template_decl;
14709 push_deferring_access_checks (dk_no_check);
14712 /* And pop back out. */
14715 pop_deduction_access_scope (tree tmpl)
14717 if (cxx_dialect >= cxx0x)
14718 pop_access_scope (DECL_TEMPLATE_RESULT (tmpl));
14720 pop_deferring_access_checks ();
14723 /* PARM is a template parameter pack for FN. Returns true iff
14724 PARM is used in a deducible way in the argument list of FN. */
14727 pack_deducible_p (tree parm, tree fn)
14729 tree t = FUNCTION_FIRST_USER_PARMTYPE (fn);
14730 for (; t; t = TREE_CHAIN (t))
14732 tree type = TREE_VALUE (t);
14734 if (!PACK_EXPANSION_P (type))
14736 for (packs = PACK_EXPANSION_PARAMETER_PACKS (type);
14737 packs; packs = TREE_CHAIN (packs))
14738 if (TREE_VALUE (packs) == parm)
14740 /* The template parameter pack is used in a function parameter
14741 pack. If this is the end of the parameter list, the
14742 template parameter pack is deducible. */
14743 if (TREE_CHAIN (t) == void_list_node)
14746 /* Otherwise, not. Well, it could be deduced from
14747 a non-pack parameter, but doing so would end up with
14748 a deduction mismatch, so don't bother. */
14752 /* The template parameter pack isn't used in any function parameter
14753 packs, but it might be used deeper, e.g. tuple<Args...>. */
14757 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
14758 NARGS elements of the arguments that are being used when calling
14759 it. TARGS is a vector into which the deduced template arguments
14762 Return zero for success, 2 for an incomplete match that doesn't resolve
14763 all the types, and 1 for complete failure. An error message will be
14764 printed only for an incomplete match.
14766 If FN is a conversion operator, or we are trying to produce a specific
14767 specialization, RETURN_TYPE is the return type desired.
14769 The EXPLICIT_TARGS are explicit template arguments provided via a
14772 The parameter STRICT is one of:
14775 We are deducing arguments for a function call, as in
14776 [temp.deduct.call].
14779 We are deducing arguments for a conversion function, as in
14780 [temp.deduct.conv].
14783 We are deducing arguments when doing an explicit instantiation
14784 as in [temp.explicit], when determining an explicit specialization
14785 as in [temp.expl.spec], or when taking the address of a function
14786 template, as in [temp.deduct.funcaddr]. */
14789 fn_type_unification (tree fn,
14790 tree explicit_targs,
14793 unsigned int nargs,
14795 unification_kind_t strict,
14803 gcc_assert (TREE_CODE (fn) == TEMPLATE_DECL);
14805 fntype = TREE_TYPE (fn);
14806 if (explicit_targs)
14810 The specified template arguments must match the template
14811 parameters in kind (i.e., type, nontype, template), and there
14812 must not be more arguments than there are parameters;
14813 otherwise type deduction fails.
14815 Nontype arguments must match the types of the corresponding
14816 nontype template parameters, or must be convertible to the
14817 types of the corresponding nontype parameters as specified in
14818 _temp.arg.nontype_, otherwise type deduction fails.
14820 All references in the function type of the function template
14821 to the corresponding template parameters are replaced by the
14822 specified template argument values. If a substitution in a
14823 template parameter or in the function type of the function
14824 template results in an invalid type, type deduction fails. */
14825 tree tparms = DECL_INNERMOST_TEMPLATE_PARMS (fn);
14826 int i, len = TREE_VEC_LENGTH (tparms);
14827 tree converted_args;
14828 bool incomplete = false;
14830 if (explicit_targs == error_mark_node)
14831 return unify_invalid (explain_p);
14834 = (coerce_template_parms (tparms, explicit_targs, NULL_TREE,
14836 ? tf_warning_or_error
14838 /*require_all_args=*/false,
14839 /*use_default_args=*/false));
14840 if (converted_args == error_mark_node)
14843 /* Substitute the explicit args into the function type. This is
14844 necessary so that, for instance, explicitly declared function
14845 arguments can match null pointed constants. If we were given
14846 an incomplete set of explicit args, we must not do semantic
14847 processing during substitution as we could create partial
14849 for (i = 0; i < len; i++)
14851 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
14852 bool parameter_pack = false;
14853 tree targ = TREE_VEC_ELT (converted_args, i);
14855 /* Dig out the actual parm. */
14856 if (TREE_CODE (parm) == TYPE_DECL
14857 || TREE_CODE (parm) == TEMPLATE_DECL)
14859 parm = TREE_TYPE (parm);
14860 parameter_pack = TEMPLATE_TYPE_PARAMETER_PACK (parm);
14862 else if (TREE_CODE (parm) == PARM_DECL)
14864 parm = DECL_INITIAL (parm);
14865 parameter_pack = TEMPLATE_PARM_PARAMETER_PACK (parm);
14868 if (!parameter_pack && targ == NULL_TREE)
14869 /* No explicit argument for this template parameter. */
14872 if (parameter_pack && pack_deducible_p (parm, fn))
14874 /* Mark the argument pack as "incomplete". We could
14875 still deduce more arguments during unification.
14876 We remove this mark in type_unification_real. */
14879 ARGUMENT_PACK_INCOMPLETE_P(targ) = 1;
14880 ARGUMENT_PACK_EXPLICIT_ARGS (targ)
14881 = ARGUMENT_PACK_ARGS (targ);
14884 /* We have some incomplete argument packs. */
14889 processing_template_decl += incomplete;
14890 fntype = deduction_tsubst_fntype (fn, converted_args,
14892 ? tf_warning_or_error
14894 processing_template_decl -= incomplete;
14896 if (fntype == error_mark_node)
14899 /* Place the explicitly specified arguments in TARGS. */
14900 for (i = NUM_TMPL_ARGS (converted_args); i--;)
14901 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (converted_args, i);
14904 /* Never do unification on the 'this' parameter. */
14905 parms = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (fntype));
14911 parms = tree_cons (NULL_TREE, TREE_TYPE (fntype), parms);
14912 new_args = XALLOCAVEC (tree, nargs + 1);
14913 new_args[0] = return_type;
14914 memcpy (new_args + 1, args, nargs * sizeof (tree));
14919 /* We allow incomplete unification without an error message here
14920 because the standard doesn't seem to explicitly prohibit it. Our
14921 callers must be ready to deal with unification failures in any
14923 result = type_unification_real (DECL_INNERMOST_TEMPLATE_PARMS (fn),
14924 targs, parms, args, nargs, /*subr=*/0,
14925 strict, flags, explain_p);
14927 /* Now that we have bindings for all of the template arguments,
14928 ensure that the arguments deduced for the template template
14929 parameters have compatible template parameter lists. We cannot
14930 check this property before we have deduced all template
14931 arguments, because the template parameter types of a template
14932 template parameter might depend on prior template parameters
14933 deduced after the template template parameter. The following
14934 ill-formed example illustrates this issue:
14936 template<typename T, template<T> class C> void f(C<5>, T);
14938 template<int N> struct X {};
14941 f(X<5>(), 5l); // error: template argument deduction fails
14944 The template parameter list of 'C' depends on the template type
14945 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
14946 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
14947 time that we deduce 'C'. */
14949 && !template_template_parm_bindings_ok_p
14950 (DECL_INNERMOST_TEMPLATE_PARMS (fn), targs))
14951 return unify_inconsistent_template_template_parameters (explain_p);
14954 /* All is well so far. Now, check:
14958 When all template arguments have been deduced, all uses of
14959 template parameters in nondeduced contexts are replaced with
14960 the corresponding deduced argument values. If the
14961 substitution results in an invalid type, as described above,
14962 type deduction fails. */
14964 tree substed = deduction_tsubst_fntype (fn, targs,
14966 ? tf_warning_or_error
14968 if (substed == error_mark_node)
14971 /* If we're looking for an exact match, check that what we got
14972 is indeed an exact match. It might not be if some template
14973 parameters are used in non-deduced contexts. */
14974 if (strict == DEDUCE_EXACT)
14979 = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (substed));
14981 sarg = tree_cons (NULL_TREE, TREE_TYPE (substed), sarg);
14982 for (i = 0; i < nargs && sarg; ++i, sarg = TREE_CHAIN (sarg))
14983 if (!same_type_p (args[i], TREE_VALUE (sarg)))
14984 return unify_type_mismatch (explain_p, args[i],
14985 TREE_VALUE (sarg));
14992 /* Adjust types before performing type deduction, as described in
14993 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
14994 sections are symmetric. PARM is the type of a function parameter
14995 or the return type of the conversion function. ARG is the type of
14996 the argument passed to the call, or the type of the value
14997 initialized with the result of the conversion function.
14998 ARG_EXPR is the original argument expression, which may be null. */
15001 maybe_adjust_types_for_deduction (unification_kind_t strict,
15015 /* Swap PARM and ARG throughout the remainder of this
15016 function; the handling is precisely symmetric since PARM
15017 will initialize ARG rather than vice versa. */
15025 /* Core issue #873: Do the DR606 thing (see below) for these cases,
15026 too, but here handle it by stripping the reference from PARM
15027 rather than by adding it to ARG. */
15028 if (TREE_CODE (*parm) == REFERENCE_TYPE
15029 && TYPE_REF_IS_RVALUE (*parm)
15030 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
15031 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
15032 && TREE_CODE (*arg) == REFERENCE_TYPE
15033 && !TYPE_REF_IS_RVALUE (*arg))
15034 *parm = TREE_TYPE (*parm);
15035 /* Nothing else to do in this case. */
15039 gcc_unreachable ();
15042 if (TREE_CODE (*parm) != REFERENCE_TYPE)
15044 /* [temp.deduct.call]
15046 If P is not a reference type:
15048 --If A is an array type, the pointer type produced by the
15049 array-to-pointer standard conversion (_conv.array_) is
15050 used in place of A for type deduction; otherwise,
15052 --If A is a function type, the pointer type produced by
15053 the function-to-pointer standard conversion
15054 (_conv.func_) is used in place of A for type deduction;
15057 --If A is a cv-qualified type, the top level
15058 cv-qualifiers of A's type are ignored for type
15060 if (TREE_CODE (*arg) == ARRAY_TYPE)
15061 *arg = build_pointer_type (TREE_TYPE (*arg));
15062 else if (TREE_CODE (*arg) == FUNCTION_TYPE)
15063 *arg = build_pointer_type (*arg);
15065 *arg = TYPE_MAIN_VARIANT (*arg);
15068 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
15069 of the form T&&, where T is a template parameter, and the argument
15070 is an lvalue, T is deduced as A& */
15071 if (TREE_CODE (*parm) == REFERENCE_TYPE
15072 && TYPE_REF_IS_RVALUE (*parm)
15073 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
15074 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
15075 && (arg_expr ? real_lvalue_p (arg_expr)
15076 /* try_one_overload doesn't provide an arg_expr, but
15077 functions are always lvalues. */
15078 : TREE_CODE (*arg) == FUNCTION_TYPE))
15079 *arg = build_reference_type (*arg);
15081 /* [temp.deduct.call]
15083 If P is a cv-qualified type, the top level cv-qualifiers
15084 of P's type are ignored for type deduction. If P is a
15085 reference type, the type referred to by P is used for
15087 *parm = TYPE_MAIN_VARIANT (*parm);
15088 if (TREE_CODE (*parm) == REFERENCE_TYPE)
15090 *parm = TREE_TYPE (*parm);
15091 result |= UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
15094 /* DR 322. For conversion deduction, remove a reference type on parm
15095 too (which has been swapped into ARG). */
15096 if (strict == DEDUCE_CONV && TREE_CODE (*arg) == REFERENCE_TYPE)
15097 *arg = TREE_TYPE (*arg);
15102 /* Subroutine of unify_one_argument. PARM is a function parameter of a
15103 template which does contain any deducible template parameters; check if
15104 ARG is a suitable match for it. STRICT, FLAGS and EXPLAIN_P are as in
15105 unify_one_argument. */
15108 check_non_deducible_conversion (tree parm, tree arg, int strict,
15109 int flags, bool explain_p)
15114 type = TREE_TYPE (arg);
15118 if (same_type_p (parm, type))
15119 return unify_success (explain_p);
15121 if (strict == DEDUCE_CONV)
15123 if (can_convert_arg (type, parm, NULL_TREE, flags))
15124 return unify_success (explain_p);
15126 else if (strict != DEDUCE_EXACT)
15128 if (can_convert_arg (parm, type,
15129 TYPE_P (arg) ? NULL_TREE : arg,
15131 return unify_success (explain_p);
15134 if (strict == DEDUCE_EXACT)
15135 return unify_type_mismatch (explain_p, parm, arg);
15137 return unify_arg_conversion (explain_p, parm, type, arg);
15140 /* Subroutine of type_unification_real and unify_pack_expansion to
15141 handle unification of a single P/A pair. Parameters are as
15142 for those functions. */
15145 unify_one_argument (tree tparms, tree targs, tree parm, tree arg,
15146 int subr, unification_kind_t strict, int flags,
15149 tree arg_expr = NULL_TREE;
15152 if (arg == error_mark_node || parm == error_mark_node)
15153 return unify_invalid (explain_p);
15154 if (arg == unknown_type_node)
15155 /* We can't deduce anything from this, but we might get all the
15156 template args from other function args. */
15157 return unify_success (explain_p);
15159 /* FIXME uses_deducible_template_parms */
15160 if (TYPE_P (parm) && !uses_template_parms (parm))
15161 return check_non_deducible_conversion (parm, arg, strict, flags,
15167 arg_strict = (UNIFY_ALLOW_OUTER_LEVEL
15168 | UNIFY_ALLOW_MORE_CV_QUAL
15169 | UNIFY_ALLOW_DERIVED);
15173 arg_strict = UNIFY_ALLOW_LESS_CV_QUAL;
15177 arg_strict = UNIFY_ALLOW_NONE;
15181 gcc_unreachable ();
15184 /* We only do these transformations if this is the top-level
15185 parameter_type_list in a call or declaration matching; in other
15186 situations (nested function declarators, template argument lists) we
15187 won't be comparing a type to an expression, and we don't do any type
15193 gcc_assert (TREE_TYPE (arg) != NULL_TREE);
15194 if (type_unknown_p (arg))
15196 /* [temp.deduct.type] A template-argument can be
15197 deduced from a pointer to function or pointer
15198 to member function argument if the set of
15199 overloaded functions does not contain function
15200 templates and at most one of a set of
15201 overloaded functions provides a unique
15204 if (resolve_overloaded_unification
15205 (tparms, targs, parm, arg, strict,
15206 arg_strict, explain_p))
15207 return unify_success (explain_p);
15208 return unify_overload_resolution_failure (explain_p, arg);
15212 arg = unlowered_expr_type (arg);
15213 if (arg == error_mark_node)
15214 return unify_invalid (explain_p);
15218 maybe_adjust_types_for_deduction (strict, &parm, &arg, arg_expr);
15221 gcc_assert ((TYPE_P (parm) || TREE_CODE (parm) == TEMPLATE_DECL)
15222 == (TYPE_P (arg) || TREE_CODE (arg) == TEMPLATE_DECL));
15224 /* For deduction from an init-list we need the actual list. */
15225 if (arg_expr && BRACE_ENCLOSED_INITIALIZER_P (arg_expr))
15227 return unify (tparms, targs, parm, arg, arg_strict, explain_p);
15230 /* Most parms like fn_type_unification.
15232 If SUBR is 1, we're being called recursively (to unify the
15233 arguments of a function or method parameter of a function
15237 type_unification_real (tree tparms,
15241 unsigned int xnargs,
15243 unification_kind_t strict,
15249 int ntparms = TREE_VEC_LENGTH (tparms);
15250 int saw_undeduced = 0;
15253 unsigned int nargs;
15256 gcc_assert (TREE_CODE (tparms) == TREE_VEC);
15257 gcc_assert (xparms == NULL_TREE || TREE_CODE (xparms) == TREE_LIST);
15258 gcc_assert (ntparms > 0);
15260 /* Reset the number of non-defaulted template arguments contained
15262 NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs) = NULL_TREE;
15270 while (parms && parms != void_list_node
15273 parm = TREE_VALUE (parms);
15275 if (TREE_CODE (parm) == TYPE_PACK_EXPANSION
15276 && (!TREE_CHAIN (parms) || TREE_CHAIN (parms) == void_list_node))
15277 /* For a function parameter pack that occurs at the end of the
15278 parameter-declaration-list, the type A of each remaining
15279 argument of the call is compared with the type P of the
15280 declarator-id of the function parameter pack. */
15283 parms = TREE_CHAIN (parms);
15285 if (TREE_CODE (parm) == TYPE_PACK_EXPANSION)
15286 /* For a function parameter pack that does not occur at the
15287 end of the parameter-declaration-list, the type of the
15288 parameter pack is a non-deduced context. */
15294 if (unify_one_argument (tparms, targs, parm, arg, subr, strict,
15300 && parms != void_list_node
15301 && TREE_CODE (TREE_VALUE (parms)) == TYPE_PACK_EXPANSION)
15303 /* Unify the remaining arguments with the pack expansion type. */
15305 tree parmvec = make_tree_vec (1);
15307 /* Allocate a TREE_VEC and copy in all of the arguments */
15308 argvec = make_tree_vec (nargs - ia);
15309 for (i = 0; ia < nargs; ++ia, ++i)
15310 TREE_VEC_ELT (argvec, i) = args[ia];
15312 /* Copy the parameter into parmvec. */
15313 TREE_VEC_ELT (parmvec, 0) = TREE_VALUE (parms);
15314 if (unify_pack_expansion (tparms, targs, parmvec, argvec, strict,
15315 /*subr=*/subr, explain_p))
15318 /* Advance to the end of the list of parameters. */
15319 parms = TREE_CHAIN (parms);
15322 /* Fail if we've reached the end of the parm list, and more args
15323 are present, and the parm list isn't variadic. */
15324 if (ia < nargs && parms == void_list_node)
15325 return unify_too_many_arguments (explain_p, nargs, ia);
15326 /* Fail if parms are left and they don't have default values. */
15327 if (parms && parms != void_list_node
15328 && TREE_PURPOSE (parms) == NULL_TREE)
15330 unsigned int count = nargs;
15332 while (p && p != void_list_node)
15335 p = TREE_CHAIN (p);
15337 return unify_too_few_arguments (explain_p, ia, count);
15342 tsubst_flags_t complain = (explain_p
15343 ? tf_warning_or_error
15346 /* Check to see if we need another pass before we start clearing
15347 ARGUMENT_PACK_INCOMPLETE_P. */
15348 for (i = 0; i < ntparms; i++)
15350 tree targ = TREE_VEC_ELT (targs, i);
15351 tree tparm = TREE_VEC_ELT (tparms, i);
15353 if (targ || tparm == error_mark_node)
15355 tparm = TREE_VALUE (tparm);
15357 /* If this is an undeduced nontype parameter that depends on
15358 a type parameter, try another pass; its type may have been
15359 deduced from a later argument than the one from which
15360 this parameter can be deduced. */
15361 if (TREE_CODE (tparm) == PARM_DECL
15362 && uses_template_parms (TREE_TYPE (tparm))
15363 && !saw_undeduced++)
15367 for (i = 0; i < ntparms; i++)
15369 tree targ = TREE_VEC_ELT (targs, i);
15370 tree tparm = TREE_VEC_ELT (tparms, i);
15372 /* Clear the "incomplete" flags on all argument packs now so that
15373 substituting them into later default arguments works. */
15374 if (targ && ARGUMENT_PACK_P (targ))
15376 ARGUMENT_PACK_INCOMPLETE_P (targ) = 0;
15377 ARGUMENT_PACK_EXPLICIT_ARGS (targ) = NULL_TREE;
15380 if (targ || tparm == error_mark_node)
15382 tparm = TREE_VALUE (tparm);
15384 /* Core issue #226 (C++0x) [temp.deduct]:
15386 If a template argument has not been deduced, its
15387 default template argument, if any, is used.
15389 When we are in C++98 mode, TREE_PURPOSE will either
15390 be NULL_TREE or ERROR_MARK_NODE, so we do not need
15391 to explicitly check cxx_dialect here. */
15392 if (TREE_PURPOSE (TREE_VEC_ELT (tparms, i)))
15394 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
15395 tree arg = TREE_PURPOSE (TREE_VEC_ELT (tparms, i));
15396 location_t save_loc = input_location;
15398 input_location = DECL_SOURCE_LOCATION (parm);
15399 arg = tsubst_template_arg (arg, targs, complain, NULL_TREE);
15400 arg = convert_template_argument (parm, arg, targs, complain,
15402 input_location = save_loc;
15403 if (arg == error_mark_node)
15407 TREE_VEC_ELT (targs, i) = arg;
15408 /* The position of the first default template argument,
15409 is also the number of non-defaulted arguments in TARGS.
15411 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs))
15412 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, i);
15417 /* If the type parameter is a parameter pack, then it will
15418 be deduced to an empty parameter pack. */
15419 if (template_parameter_pack_p (tparm))
15423 if (TREE_CODE (tparm) == TEMPLATE_PARM_INDEX)
15425 arg = make_node (NONTYPE_ARGUMENT_PACK);
15426 TREE_TYPE (arg) = TREE_TYPE (TEMPLATE_PARM_DECL (tparm));
15427 TREE_CONSTANT (arg) = 1;
15430 arg = cxx_make_type (TYPE_ARGUMENT_PACK);
15432 SET_ARGUMENT_PACK_ARGS (arg, make_tree_vec (0));
15434 TREE_VEC_ELT (targs, i) = arg;
15438 return unify_parameter_deduction_failure (explain_p, tparm);
15441 #ifdef ENABLE_CHECKING
15442 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs))
15443 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, TREE_VEC_LENGTH (targs));
15446 return unify_success (explain_p);
15449 /* Subroutine of type_unification_real. Args are like the variables
15450 at the call site. ARG is an overloaded function (or template-id);
15451 we try deducing template args from each of the overloads, and if
15452 only one succeeds, we go with that. Modifies TARGS and returns
15453 true on success. */
15456 resolve_overloaded_unification (tree tparms,
15460 unification_kind_t strict,
15464 tree tempargs = copy_node (targs);
15466 tree goodfn = NULL_TREE;
15469 if (TREE_CODE (arg) == ADDR_EXPR)
15471 arg = TREE_OPERAND (arg, 0);
15477 if (TREE_CODE (arg) == COMPONENT_REF)
15478 /* Handle `&x' where `x' is some static or non-static member
15480 arg = TREE_OPERAND (arg, 1);
15482 if (TREE_CODE (arg) == OFFSET_REF)
15483 arg = TREE_OPERAND (arg, 1);
15485 /* Strip baselink information. */
15486 if (BASELINK_P (arg))
15487 arg = BASELINK_FUNCTIONS (arg);
15489 if (TREE_CODE (arg) == TEMPLATE_ID_EXPR)
15491 /* If we got some explicit template args, we need to plug them into
15492 the affected templates before we try to unify, in case the
15493 explicit args will completely resolve the templates in question. */
15496 tree expl_subargs = TREE_OPERAND (arg, 1);
15497 arg = TREE_OPERAND (arg, 0);
15499 for (; arg; arg = OVL_NEXT (arg))
15501 tree fn = OVL_CURRENT (arg);
15502 tree subargs, elem;
15504 if (TREE_CODE (fn) != TEMPLATE_DECL)
15507 ++processing_template_decl;
15508 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
15509 expl_subargs, /*check_ret=*/false);
15510 if (subargs && !any_dependent_template_arguments_p (subargs))
15512 elem = tsubst (TREE_TYPE (fn), subargs, tf_none, NULL_TREE);
15513 if (try_one_overload (tparms, targs, tempargs, parm,
15514 elem, strict, sub_strict, addr_p, explain_p)
15515 && (!goodfn || !same_type_p (goodfn, elem)))
15523 --processing_template_decl;
15525 /* If no templates (or more than one) are fully resolved by the
15526 explicit arguments, this template-id is a non-deduced context; it
15527 could still be OK if we deduce all template arguments for the
15528 enclosing call through other arguments. */
15532 else if (TREE_CODE (arg) != OVERLOAD
15533 && TREE_CODE (arg) != FUNCTION_DECL)
15534 /* If ARG is, for example, "(0, &f)" then its type will be unknown
15535 -- but the deduction does not succeed because the expression is
15536 not just the function on its own. */
15539 for (; arg; arg = OVL_NEXT (arg))
15540 if (try_one_overload (tparms, targs, tempargs, parm,
15541 TREE_TYPE (OVL_CURRENT (arg)),
15542 strict, sub_strict, addr_p, explain_p)
15543 && (!goodfn || !decls_match (goodfn, OVL_CURRENT (arg))))
15545 goodfn = OVL_CURRENT (arg);
15549 /* [temp.deduct.type] A template-argument can be deduced from a pointer
15550 to function or pointer to member function argument if the set of
15551 overloaded functions does not contain function templates and at most
15552 one of a set of overloaded functions provides a unique match.
15554 So if we found multiple possibilities, we return success but don't
15555 deduce anything. */
15559 int i = TREE_VEC_LENGTH (targs);
15561 if (TREE_VEC_ELT (tempargs, i))
15562 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (tempargs, i);
15570 /* Core DR 115: In contexts where deduction is done and fails, or in
15571 contexts where deduction is not done, if a template argument list is
15572 specified and it, along with any default template arguments, identifies
15573 a single function template specialization, then the template-id is an
15574 lvalue for the function template specialization. */
15577 resolve_nondeduced_context (tree orig_expr)
15579 tree expr, offset, baselink;
15582 if (!type_unknown_p (orig_expr))
15587 offset = NULL_TREE;
15588 baselink = NULL_TREE;
15590 if (TREE_CODE (expr) == ADDR_EXPR)
15592 expr = TREE_OPERAND (expr, 0);
15595 if (TREE_CODE (expr) == OFFSET_REF)
15598 expr = TREE_OPERAND (expr, 1);
15600 if (BASELINK_P (expr))
15603 expr = BASELINK_FUNCTIONS (expr);
15606 if (TREE_CODE (expr) == TEMPLATE_ID_EXPR)
15609 tree goodfn = NULL_TREE;
15611 /* If we got some explicit template args, we need to plug them into
15612 the affected templates before we try to unify, in case the
15613 explicit args will completely resolve the templates in question. */
15615 tree expl_subargs = TREE_OPERAND (expr, 1);
15616 tree arg = TREE_OPERAND (expr, 0);
15617 tree badfn = NULL_TREE;
15618 tree badargs = NULL_TREE;
15620 for (; arg; arg = OVL_NEXT (arg))
15622 tree fn = OVL_CURRENT (arg);
15623 tree subargs, elem;
15625 if (TREE_CODE (fn) != TEMPLATE_DECL)
15628 ++processing_template_decl;
15629 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
15630 expl_subargs, /*check_ret=*/false);
15631 if (subargs && !any_dependent_template_arguments_p (subargs))
15633 elem = instantiate_template (fn, subargs, tf_none);
15634 if (elem == error_mark_node)
15639 else if (elem && (!goodfn || !decls_match (goodfn, elem)))
15645 --processing_template_decl;
15649 mark_used (goodfn);
15652 expr = build_baselink (BASELINK_BINFO (baselink),
15653 BASELINK_ACCESS_BINFO (baselink),
15654 expr, BASELINK_OPTYPE (baselink));
15658 = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (offset, 0)));
15659 expr = build_offset_ref (base, expr, addr);
15662 expr = cp_build_addr_expr (expr, tf_warning_or_error);
15665 else if (good == 0 && badargs)
15666 /* There were no good options and at least one bad one, so let the
15667 user know what the problem is. */
15668 instantiate_template (badfn, badargs, tf_warning_or_error);
15673 /* Subroutine of resolve_overloaded_unification; does deduction for a single
15674 overload. Fills TARGS with any deduced arguments, or error_mark_node if
15675 different overloads deduce different arguments for a given parm.
15676 ADDR_P is true if the expression for which deduction is being
15677 performed was of the form "& fn" rather than simply "fn".
15679 Returns 1 on success. */
15682 try_one_overload (tree tparms,
15687 unification_kind_t strict,
15696 /* [temp.deduct.type] A template-argument can be deduced from a pointer
15697 to function or pointer to member function argument if the set of
15698 overloaded functions does not contain function templates and at most
15699 one of a set of overloaded functions provides a unique match.
15701 So if this is a template, just return success. */
15703 if (uses_template_parms (arg))
15706 if (TREE_CODE (arg) == METHOD_TYPE)
15707 arg = build_ptrmemfunc_type (build_pointer_type (arg));
15709 arg = build_pointer_type (arg);
15711 sub_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg, NULL);
15713 /* We don't copy orig_targs for this because if we have already deduced
15714 some template args from previous args, unify would complain when we
15715 try to deduce a template parameter for the same argument, even though
15716 there isn't really a conflict. */
15717 nargs = TREE_VEC_LENGTH (targs);
15718 tempargs = make_tree_vec (nargs);
15720 if (unify (tparms, tempargs, parm, arg, sub_strict, explain_p))
15723 /* First make sure we didn't deduce anything that conflicts with
15724 explicitly specified args. */
15725 for (i = nargs; i--; )
15727 tree elt = TREE_VEC_ELT (tempargs, i);
15728 tree oldelt = TREE_VEC_ELT (orig_targs, i);
15732 else if (uses_template_parms (elt))
15733 /* Since we're unifying against ourselves, we will fill in
15734 template args used in the function parm list with our own
15735 template parms. Discard them. */
15736 TREE_VEC_ELT (tempargs, i) = NULL_TREE;
15737 else if (oldelt && !template_args_equal (oldelt, elt))
15741 for (i = nargs; i--; )
15743 tree elt = TREE_VEC_ELT (tempargs, i);
15746 TREE_VEC_ELT (targs, i) = elt;
15752 /* PARM is a template class (perhaps with unbound template
15753 parameters). ARG is a fully instantiated type. If ARG can be
15754 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
15755 TARGS are as for unify. */
15758 try_class_unification (tree tparms, tree targs, tree parm, tree arg,
15761 tree copy_of_targs;
15763 if (!CLASSTYPE_TEMPLATE_INFO (arg)
15764 || (most_general_template (CLASSTYPE_TI_TEMPLATE (arg))
15765 != most_general_template (CLASSTYPE_TI_TEMPLATE (parm))))
15768 /* We need to make a new template argument vector for the call to
15769 unify. If we used TARGS, we'd clutter it up with the result of
15770 the attempted unification, even if this class didn't work out.
15771 We also don't want to commit ourselves to all the unifications
15772 we've already done, since unification is supposed to be done on
15773 an argument-by-argument basis. In other words, consider the
15774 following pathological case:
15776 template <int I, int J, int K>
15779 template <int I, int J>
15780 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
15782 template <int I, int J, int K>
15783 void f(S<I, J, K>, S<I, I, I>);
15792 Now, by the time we consider the unification involving `s2', we
15793 already know that we must have `f<0, 0, 0>'. But, even though
15794 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
15795 because there are two ways to unify base classes of S<0, 1, 2>
15796 with S<I, I, I>. If we kept the already deduced knowledge, we
15797 would reject the possibility I=1. */
15798 copy_of_targs = make_tree_vec (TREE_VEC_LENGTH (targs));
15800 /* If unification failed, we're done. */
15801 if (unify (tparms, copy_of_targs, CLASSTYPE_TI_ARGS (parm),
15802 CLASSTYPE_TI_ARGS (arg), UNIFY_ALLOW_NONE, explain_p))
15808 /* Given a template type PARM and a class type ARG, find the unique
15809 base type in ARG that is an instance of PARM. We do not examine
15810 ARG itself; only its base-classes. If there is not exactly one
15811 appropriate base class, return NULL_TREE. PARM may be the type of
15812 a partial specialization, as well as a plain template type. Used
15815 static enum template_base_result
15816 get_template_base (tree tparms, tree targs, tree parm, tree arg,
15817 bool explain_p, tree *result)
15819 tree rval = NULL_TREE;
15822 gcc_assert (RECORD_OR_UNION_CODE_P (TREE_CODE (arg)));
15824 binfo = TYPE_BINFO (complete_type (arg));
15827 /* The type could not be completed. */
15828 *result = NULL_TREE;
15829 return tbr_incomplete_type;
15832 /* Walk in inheritance graph order. The search order is not
15833 important, and this avoids multiple walks of virtual bases. */
15834 for (binfo = TREE_CHAIN (binfo); binfo; binfo = TREE_CHAIN (binfo))
15836 tree r = try_class_unification (tparms, targs, parm,
15837 BINFO_TYPE (binfo), explain_p);
15841 /* If there is more than one satisfactory baseclass, then:
15845 If they yield more than one possible deduced A, the type
15849 if (rval && !same_type_p (r, rval))
15851 *result = NULL_TREE;
15852 return tbr_ambiguous_baseclass;
15860 return tbr_success;
15863 /* Returns the level of DECL, which declares a template parameter. */
15866 template_decl_level (tree decl)
15868 switch (TREE_CODE (decl))
15871 case TEMPLATE_DECL:
15872 return TEMPLATE_TYPE_LEVEL (TREE_TYPE (decl));
15875 return TEMPLATE_PARM_LEVEL (DECL_INITIAL (decl));
15878 gcc_unreachable ();
15883 /* Decide whether ARG can be unified with PARM, considering only the
15884 cv-qualifiers of each type, given STRICT as documented for unify.
15885 Returns nonzero iff the unification is OK on that basis. */
15888 check_cv_quals_for_unify (int strict, tree arg, tree parm)
15890 int arg_quals = cp_type_quals (arg);
15891 int parm_quals = cp_type_quals (parm);
15893 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
15894 && !(strict & UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
15896 /* Although a CVR qualifier is ignored when being applied to a
15897 substituted template parameter ([8.3.2]/1 for example), that
15898 does not allow us to unify "const T" with "int&" because both
15899 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
15900 It is ok when we're allowing additional CV qualifiers
15901 at the outer level [14.8.2.1]/3,1st bullet. */
15902 if ((TREE_CODE (arg) == REFERENCE_TYPE
15903 || TREE_CODE (arg) == FUNCTION_TYPE
15904 || TREE_CODE (arg) == METHOD_TYPE)
15905 && (parm_quals & (TYPE_QUAL_CONST | TYPE_QUAL_VOLATILE)))
15908 if ((!POINTER_TYPE_P (arg) && TREE_CODE (arg) != TEMPLATE_TYPE_PARM)
15909 && (parm_quals & TYPE_QUAL_RESTRICT))
15913 if (!(strict & (UNIFY_ALLOW_MORE_CV_QUAL | UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
15914 && (arg_quals & parm_quals) != parm_quals)
15917 if (!(strict & (UNIFY_ALLOW_LESS_CV_QUAL | UNIFY_ALLOW_OUTER_LESS_CV_QUAL))
15918 && (parm_quals & arg_quals) != arg_quals)
15924 /* Determines the LEVEL and INDEX for the template parameter PARM. */
15926 template_parm_level_and_index (tree parm, int* level, int* index)
15928 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
15929 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
15930 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
15932 *index = TEMPLATE_TYPE_IDX (parm);
15933 *level = TEMPLATE_TYPE_LEVEL (parm);
15937 *index = TEMPLATE_PARM_IDX (parm);
15938 *level = TEMPLATE_PARM_LEVEL (parm);
15942 #define RECUR_AND_CHECK_FAILURE(TP, TA, P, A, S, EP) \
15944 if (unify (TP, TA, P, A, S, EP)) \
15948 /* Unifies the remaining arguments in PACKED_ARGS with the pack
15949 expansion at the end of PACKED_PARMS. Returns 0 if the type
15950 deduction succeeds, 1 otherwise. STRICT is the same as in
15951 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
15952 call argument list. We'll need to adjust the arguments to make them
15953 types. SUBR tells us if this is from a recursive call to
15954 type_unification_real, or for comparing two template argument
15958 unify_pack_expansion (tree tparms, tree targs, tree packed_parms,
15959 tree packed_args, unification_kind_t strict,
15960 bool subr, bool explain_p)
15963 = TREE_VEC_ELT (packed_parms, TREE_VEC_LENGTH (packed_parms) - 1);
15964 tree pattern = PACK_EXPANSION_PATTERN (parm);
15965 tree pack, packs = NULL_TREE;
15966 int i, start = TREE_VEC_LENGTH (packed_parms) - 1;
15967 int len = TREE_VEC_LENGTH (packed_args);
15969 /* Determine the parameter packs we will be deducing from the
15970 pattern, and record their current deductions. */
15971 for (pack = PACK_EXPANSION_PARAMETER_PACKS (parm);
15972 pack; pack = TREE_CHAIN (pack))
15974 tree parm_pack = TREE_VALUE (pack);
15977 /* Determine the index and level of this parameter pack. */
15978 template_parm_level_and_index (parm_pack, &level, &idx);
15980 /* Keep track of the parameter packs and their corresponding
15982 packs = tree_cons (parm_pack, TMPL_ARG (targs, level, idx), packs);
15983 TREE_TYPE (packs) = make_tree_vec (len - start);
15986 /* Loop through all of the arguments that have not yet been
15987 unified and unify each with the pattern. */
15988 for (i = start; i < len; i++)
15991 bool any_explicit = false;
15992 tree arg = TREE_VEC_ELT (packed_args, i);
15994 /* For each parameter pack, set its TMPL_ARG to either NULL_TREE
15995 or the element of its argument pack at the current index if
15996 this argument was explicitly specified. */
15997 for (pack = packs; pack; pack = TREE_CHAIN (pack))
16001 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
16004 if (TREE_VALUE (pack)
16005 && (pargs = ARGUMENT_PACK_EXPLICIT_ARGS (TREE_VALUE (pack)))
16006 && (i < TREE_VEC_LENGTH (pargs)))
16008 any_explicit = true;
16009 arg = TREE_VEC_ELT (pargs, i);
16011 TMPL_ARG (targs, level, idx) = arg;
16014 /* If we had explicit template arguments, substitute them into the
16015 pattern before deduction. */
16018 /* Some arguments might still be unspecified or dependent. */
16020 ++processing_template_decl;
16021 dependent = any_dependent_template_arguments_p (targs);
16023 --processing_template_decl;
16024 parm = tsubst (pattern, targs,
16025 explain_p ? tf_warning_or_error : tf_none,
16028 --processing_template_decl;
16029 if (parm == error_mark_node)
16035 /* Unify the pattern with the current argument. */
16036 if (unify_one_argument (tparms, targs, parm, arg, subr, strict,
16037 LOOKUP_IMPLICIT, explain_p))
16040 /* For each parameter pack, collect the deduced value. */
16041 for (pack = packs; pack; pack = TREE_CHAIN (pack))
16044 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
16046 TREE_VEC_ELT (TREE_TYPE (pack), i - start) =
16047 TMPL_ARG (targs, level, idx);
16051 /* Verify that the results of unification with the parameter packs
16052 produce results consistent with what we've seen before, and make
16053 the deduced argument packs available. */
16054 for (pack = packs; pack; pack = TREE_CHAIN (pack))
16056 tree old_pack = TREE_VALUE (pack);
16057 tree new_args = TREE_TYPE (pack);
16058 int i, len = TREE_VEC_LENGTH (new_args);
16060 bool nondeduced_p = false;
16062 /* By default keep the original deduced argument pack.
16063 If necessary, more specific code is going to update the
16064 resulting deduced argument later down in this function. */
16065 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
16066 TMPL_ARG (targs, level, idx) = old_pack;
16068 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
16069 actually deduce anything. */
16070 for (i = 0; i < len && !nondeduced_p; ++i)
16071 if (TREE_VEC_ELT (new_args, i) == NULL_TREE)
16072 nondeduced_p = true;
16076 if (old_pack && ARGUMENT_PACK_INCOMPLETE_P (old_pack))
16078 /* If we had fewer function args than explicit template args,
16079 just use the explicits. */
16080 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
16081 int explicit_len = TREE_VEC_LENGTH (explicit_args);
16082 if (len < explicit_len)
16083 new_args = explicit_args;
16089 /* Build the deduced *_ARGUMENT_PACK. */
16090 if (TREE_CODE (TREE_PURPOSE (pack)) == TEMPLATE_PARM_INDEX)
16092 result = make_node (NONTYPE_ARGUMENT_PACK);
16093 TREE_TYPE (result) =
16094 TREE_TYPE (TEMPLATE_PARM_DECL (TREE_PURPOSE (pack)));
16095 TREE_CONSTANT (result) = 1;
16098 result = cxx_make_type (TYPE_ARGUMENT_PACK);
16100 SET_ARGUMENT_PACK_ARGS (result, new_args);
16102 /* Note the deduced argument packs for this parameter
16104 TMPL_ARG (targs, level, idx) = result;
16106 else if (ARGUMENT_PACK_INCOMPLETE_P (old_pack)
16107 && (ARGUMENT_PACK_ARGS (old_pack)
16108 == ARGUMENT_PACK_EXPLICIT_ARGS (old_pack)))
16110 /* We only had the explicitly-provided arguments before, but
16111 now we have a complete set of arguments. */
16112 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
16114 SET_ARGUMENT_PACK_ARGS (old_pack, new_args);
16115 ARGUMENT_PACK_INCOMPLETE_P (old_pack) = 1;
16116 ARGUMENT_PACK_EXPLICIT_ARGS (old_pack) = explicit_args;
16120 tree bad_old_arg = NULL_TREE, bad_new_arg = NULL_TREE;
16121 tree old_args = ARGUMENT_PACK_ARGS (old_pack);
16123 if (!comp_template_args_with_info (old_args, new_args,
16124 &bad_old_arg, &bad_new_arg))
16125 /* Inconsistent unification of this parameter pack. */
16126 return unify_parameter_pack_inconsistent (explain_p,
16132 return unify_success (explain_p);
16135 /* Deduce the value of template parameters. TPARMS is the (innermost)
16136 set of template parameters to a template. TARGS is the bindings
16137 for those template parameters, as determined thus far; TARGS may
16138 include template arguments for outer levels of template parameters
16139 as well. PARM is a parameter to a template function, or a
16140 subcomponent of that parameter; ARG is the corresponding argument.
16141 This function attempts to match PARM with ARG in a manner
16142 consistent with the existing assignments in TARGS. If more values
16143 are deduced, then TARGS is updated.
16145 Returns 0 if the type deduction succeeds, 1 otherwise. The
16146 parameter STRICT is a bitwise or of the following flags:
16149 Require an exact match between PARM and ARG.
16150 UNIFY_ALLOW_MORE_CV_QUAL:
16151 Allow the deduced ARG to be more cv-qualified (by qualification
16152 conversion) than ARG.
16153 UNIFY_ALLOW_LESS_CV_QUAL:
16154 Allow the deduced ARG to be less cv-qualified than ARG.
16155 UNIFY_ALLOW_DERIVED:
16156 Allow the deduced ARG to be a template base class of ARG,
16157 or a pointer to a template base class of the type pointed to by
16159 UNIFY_ALLOW_INTEGER:
16160 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
16161 case for more information.
16162 UNIFY_ALLOW_OUTER_LEVEL:
16163 This is the outermost level of a deduction. Used to determine validity
16164 of qualification conversions. A valid qualification conversion must
16165 have const qualified pointers leading up to the inner type which
16166 requires additional CV quals, except at the outer level, where const
16167 is not required [conv.qual]. It would be normal to set this flag in
16168 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
16169 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
16170 This is the outermost level of a deduction, and PARM can be more CV
16171 qualified at this point.
16172 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
16173 This is the outermost level of a deduction, and PARM can be less CV
16174 qualified at this point. */
16177 unify (tree tparms, tree targs, tree parm, tree arg, int strict,
16183 int strict_in = strict;
16185 /* I don't think this will do the right thing with respect to types.
16186 But the only case I've seen it in so far has been array bounds, where
16187 signedness is the only information lost, and I think that will be
16189 while (TREE_CODE (parm) == NOP_EXPR)
16190 parm = TREE_OPERAND (parm, 0);
16192 if (arg == error_mark_node)
16193 return unify_invalid (explain_p);
16194 if (arg == unknown_type_node
16195 || arg == init_list_type_node)
16196 /* We can't deduce anything from this, but we might get all the
16197 template args from other function args. */
16198 return unify_success (explain_p);
16200 /* If PARM uses template parameters, then we can't bail out here,
16201 even if ARG == PARM, since we won't record unifications for the
16202 template parameters. We might need them if we're trying to
16203 figure out which of two things is more specialized. */
16204 if (arg == parm && !uses_template_parms (parm))
16205 return unify_success (explain_p);
16207 /* Handle init lists early, so the rest of the function can assume
16208 we're dealing with a type. */
16209 if (BRACE_ENCLOSED_INITIALIZER_P (arg))
16213 tree orig_parm = parm;
16215 /* Replace T with std::initializer_list<T> for deduction. */
16216 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
16217 && flag_deduce_init_list)
16218 parm = listify (parm);
16220 if (!is_std_init_list (parm))
16221 /* We can only deduce from an initializer list argument if the
16222 parameter is std::initializer_list; otherwise this is a
16223 non-deduced context. */
16224 return unify_success (explain_p);
16226 elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (parm), 0);
16228 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg), i, elt)
16230 int elt_strict = strict;
16232 if (elt == error_mark_node)
16233 return unify_invalid (explain_p);
16235 if (!BRACE_ENCLOSED_INITIALIZER_P (elt))
16237 tree type = TREE_TYPE (elt);
16238 /* It should only be possible to get here for a call. */
16239 gcc_assert (elt_strict & UNIFY_ALLOW_OUTER_LEVEL);
16240 elt_strict |= maybe_adjust_types_for_deduction
16241 (DEDUCE_CALL, &elttype, &type, elt);
16245 RECUR_AND_CHECK_FAILURE (tparms, targs, elttype, elt, elt_strict,
16249 /* If the std::initializer_list<T> deduction worked, replace the
16250 deduced A with std::initializer_list<A>. */
16251 if (orig_parm != parm)
16253 idx = TEMPLATE_TYPE_IDX (orig_parm);
16254 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
16255 targ = listify (targ);
16256 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = targ;
16258 return unify_success (explain_p);
16261 /* Immediately reject some pairs that won't unify because of
16262 cv-qualification mismatches. */
16263 if (TREE_CODE (arg) == TREE_CODE (parm)
16265 /* It is the elements of the array which hold the cv quals of an array
16266 type, and the elements might be template type parms. We'll check
16267 when we recurse. */
16268 && TREE_CODE (arg) != ARRAY_TYPE
16269 /* We check the cv-qualifiers when unifying with template type
16270 parameters below. We want to allow ARG `const T' to unify with
16271 PARM `T' for example, when computing which of two templates
16272 is more specialized, for example. */
16273 && TREE_CODE (arg) != TEMPLATE_TYPE_PARM
16274 && !check_cv_quals_for_unify (strict_in, arg, parm))
16275 return unify_cv_qual_mismatch (explain_p, parm, arg);
16277 if (!(strict & UNIFY_ALLOW_OUTER_LEVEL)
16278 && TYPE_P (parm) && !CP_TYPE_CONST_P (parm))
16279 strict &= ~UNIFY_ALLOW_MORE_CV_QUAL;
16280 strict &= ~UNIFY_ALLOW_OUTER_LEVEL;
16281 strict &= ~UNIFY_ALLOW_DERIVED;
16282 strict &= ~UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
16283 strict &= ~UNIFY_ALLOW_OUTER_LESS_CV_QUAL;
16285 switch (TREE_CODE (parm))
16287 case TYPENAME_TYPE:
16289 case UNBOUND_CLASS_TEMPLATE:
16290 /* In a type which contains a nested-name-specifier, template
16291 argument values cannot be deduced for template parameters used
16292 within the nested-name-specifier. */
16293 return unify_success (explain_p);
16295 case TEMPLATE_TYPE_PARM:
16296 case TEMPLATE_TEMPLATE_PARM:
16297 case BOUND_TEMPLATE_TEMPLATE_PARM:
16298 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
16299 if (tparm == error_mark_node)
16300 return unify_invalid (explain_p);
16302 if (TEMPLATE_TYPE_LEVEL (parm)
16303 != template_decl_level (tparm))
16304 /* The PARM is not one we're trying to unify. Just check
16305 to see if it matches ARG. */
16307 if (TREE_CODE (arg) == TREE_CODE (parm)
16308 && same_type_p (parm, arg))
16309 return unify_success (explain_p);
16311 return unify_type_mismatch (explain_p, parm, arg);
16313 idx = TEMPLATE_TYPE_IDX (parm);
16314 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
16315 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, idx));
16316 if (tparm == error_mark_node)
16317 return unify_invalid (explain_p);
16319 /* Check for mixed types and values. */
16320 if ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
16321 && TREE_CODE (tparm) != TYPE_DECL)
16322 || (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
16323 && TREE_CODE (tparm) != TEMPLATE_DECL))
16324 gcc_unreachable ();
16326 if (TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
16328 /* ARG must be constructed from a template class or a template
16329 template parameter. */
16330 if (TREE_CODE (arg) != BOUND_TEMPLATE_TEMPLATE_PARM
16331 && !CLASSTYPE_SPECIALIZATION_OF_PRIMARY_TEMPLATE_P (arg))
16332 return unify_template_deduction_failure (explain_p, parm, arg);
16335 tree parmvec = TYPE_TI_ARGS (parm);
16336 tree argvec = INNERMOST_TEMPLATE_ARGS (TYPE_TI_ARGS (arg));
16337 tree full_argvec = add_to_template_args (targs, argvec);
16339 = DECL_INNERMOST_TEMPLATE_PARMS
16340 (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (parm));
16342 int parm_variadic_p = 0;
16344 /* The resolution to DR150 makes clear that default
16345 arguments for an N-argument may not be used to bind T
16346 to a template template parameter with fewer than N
16347 parameters. It is not safe to permit the binding of
16348 default arguments as an extension, as that may change
16349 the meaning of a conforming program. Consider:
16351 struct Dense { static const unsigned int dim = 1; };
16353 template <template <typename> class View,
16355 void operator+(float, View<Block> const&);
16357 template <typename Block,
16358 unsigned int Dim = Block::dim>
16359 struct Lvalue_proxy { operator float() const; };
16363 Lvalue_proxy<Dense> p;
16368 Here, if Lvalue_proxy is permitted to bind to View, then
16369 the global operator+ will be used; if they are not, the
16370 Lvalue_proxy will be converted to float. */
16371 if (coerce_template_parms (parm_parms,
16373 TYPE_TI_TEMPLATE (parm),
16375 ? tf_warning_or_error
16377 /*require_all_args=*/true,
16378 /*use_default_args=*/false)
16379 == error_mark_node)
16382 /* Deduce arguments T, i from TT<T> or TT<i>.
16383 We check each element of PARMVEC and ARGVEC individually
16384 rather than the whole TREE_VEC since they can have
16385 different number of elements. */
16387 parmvec = expand_template_argument_pack (parmvec);
16388 argvec = expand_template_argument_pack (argvec);
16390 len = TREE_VEC_LENGTH (parmvec);
16392 /* Check if the parameters end in a pack, making them
16395 && PACK_EXPANSION_P (TREE_VEC_ELT (parmvec, len - 1)))
16396 parm_variadic_p = 1;
16398 if (TREE_VEC_LENGTH (argvec) < len - parm_variadic_p)
16399 return unify_too_few_arguments (explain_p,
16400 TREE_VEC_LENGTH (argvec), len);
16402 for (i = 0; i < len - parm_variadic_p; ++i)
16404 RECUR_AND_CHECK_FAILURE (tparms, targs,
16405 TREE_VEC_ELT (parmvec, i),
16406 TREE_VEC_ELT (argvec, i),
16407 UNIFY_ALLOW_NONE, explain_p);
16410 if (parm_variadic_p
16411 && unify_pack_expansion (tparms, targs,
16414 /*subr=*/true, explain_p))
16417 arg = TYPE_TI_TEMPLATE (arg);
16419 /* Fall through to deduce template name. */
16422 if (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
16423 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
16425 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
16427 /* Simple cases: Value already set, does match or doesn't. */
16428 if (targ != NULL_TREE && template_args_equal (targ, arg))
16429 return unify_success (explain_p);
16431 return unify_inconsistency (explain_p, parm, targ, arg);
16435 /* If PARM is `const T' and ARG is only `int', we don't have
16436 a match unless we are allowing additional qualification.
16437 If ARG is `const int' and PARM is just `T' that's OK;
16438 that binds `const int' to `T'. */
16439 if (!check_cv_quals_for_unify (strict_in | UNIFY_ALLOW_LESS_CV_QUAL,
16441 return unify_cv_qual_mismatch (explain_p, parm, arg);
16443 /* Consider the case where ARG is `const volatile int' and
16444 PARM is `const T'. Then, T should be `volatile int'. */
16445 arg = cp_build_qualified_type_real
16446 (arg, cp_type_quals (arg) & ~cp_type_quals (parm), tf_none);
16447 if (arg == error_mark_node)
16448 return unify_invalid (explain_p);
16450 /* Simple cases: Value already set, does match or doesn't. */
16451 if (targ != NULL_TREE && same_type_p (targ, arg))
16452 return unify_success (explain_p);
16454 return unify_inconsistency (explain_p, parm, targ, arg);
16456 /* Make sure that ARG is not a variable-sized array. (Note
16457 that were talking about variable-sized arrays (like
16458 `int[n]'), rather than arrays of unknown size (like
16459 `int[]').) We'll get very confused by such a type since
16460 the bound of the array is not constant, and therefore
16461 not mangleable. Besides, such types are not allowed in
16462 ISO C++, so we can do as we please here. We do allow
16463 them for 'auto' deduction, since that isn't ABI-exposed. */
16464 if (!is_auto (parm) && variably_modified_type_p (arg, NULL_TREE))
16465 return unify_vla_arg (explain_p, arg);
16467 /* Strip typedefs as in convert_template_argument. */
16468 arg = canonicalize_type_argument (arg, tf_none);
16471 /* If ARG is a parameter pack or an expansion, we cannot unify
16472 against it unless PARM is also a parameter pack. */
16473 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
16474 && !template_parameter_pack_p (parm))
16475 return unify_parameter_pack_mismatch (explain_p, parm, arg);
16477 /* If the argument deduction results is a METHOD_TYPE,
16478 then there is a problem.
16479 METHOD_TYPE doesn't map to any real C++ type the result of
16480 the deduction can not be of that type. */
16481 if (TREE_CODE (arg) == METHOD_TYPE)
16482 return unify_method_type_error (explain_p, arg);
16484 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
16485 return unify_success (explain_p);
16487 case TEMPLATE_PARM_INDEX:
16488 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
16489 if (tparm == error_mark_node)
16490 return unify_invalid (explain_p);
16492 if (TEMPLATE_PARM_LEVEL (parm)
16493 != template_decl_level (tparm))
16495 /* The PARM is not one we're trying to unify. Just check
16496 to see if it matches ARG. */
16497 int result = !(TREE_CODE (arg) == TREE_CODE (parm)
16498 && cp_tree_equal (parm, arg));
16500 unify_expression_unequal (explain_p, parm, arg);
16504 idx = TEMPLATE_PARM_IDX (parm);
16505 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
16509 int x = !cp_tree_equal (targ, arg);
16511 unify_inconsistency (explain_p, parm, targ, arg);
16515 /* [temp.deduct.type] If, in the declaration of a function template
16516 with a non-type template-parameter, the non-type
16517 template-parameter is used in an expression in the function
16518 parameter-list and, if the corresponding template-argument is
16519 deduced, the template-argument type shall match the type of the
16520 template-parameter exactly, except that a template-argument
16521 deduced from an array bound may be of any integral type.
16522 The non-type parameter might use already deduced type parameters. */
16523 tparm = tsubst (TREE_TYPE (parm), targs, 0, NULL_TREE);
16524 if (!TREE_TYPE (arg))
16525 /* Template-parameter dependent expression. Just accept it for now.
16526 It will later be processed in convert_template_argument. */
16528 else if (same_type_p (TREE_TYPE (arg), tparm))
16530 else if ((strict & UNIFY_ALLOW_INTEGER)
16531 && (TREE_CODE (tparm) == INTEGER_TYPE
16532 || TREE_CODE (tparm) == BOOLEAN_TYPE))
16533 /* Convert the ARG to the type of PARM; the deduced non-type
16534 template argument must exactly match the types of the
16535 corresponding parameter. */
16536 arg = fold (build_nop (tparm, arg));
16537 else if (uses_template_parms (tparm))
16538 /* We haven't deduced the type of this parameter yet. Try again
16540 return unify_success (explain_p);
16542 return unify_type_mismatch (explain_p, tparm, arg);
16544 /* If ARG is a parameter pack or an expansion, we cannot unify
16545 against it unless PARM is also a parameter pack. */
16546 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
16547 && !TEMPLATE_PARM_PARAMETER_PACK (parm))
16548 return unify_parameter_pack_mismatch (explain_p, parm, arg);
16550 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
16551 return unify_success (explain_p);
16555 /* A pointer-to-member constant can be unified only with
16556 another constant. */
16557 if (TREE_CODE (arg) != PTRMEM_CST)
16558 return unify_ptrmem_cst_mismatch (explain_p, parm, arg);
16560 /* Just unify the class member. It would be useless (and possibly
16561 wrong, depending on the strict flags) to unify also
16562 PTRMEM_CST_CLASS, because we want to be sure that both parm and
16563 arg refer to the same variable, even if through different
16564 classes. For instance:
16566 struct A { int x; };
16569 Unification of &A::x and &B::x must succeed. */
16570 return unify (tparms, targs, PTRMEM_CST_MEMBER (parm),
16571 PTRMEM_CST_MEMBER (arg), strict, explain_p);
16576 if (TREE_CODE (arg) != POINTER_TYPE)
16577 return unify_type_mismatch (explain_p, parm, arg);
16579 /* [temp.deduct.call]
16581 A can be another pointer or pointer to member type that can
16582 be converted to the deduced A via a qualification
16583 conversion (_conv.qual_).
16585 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
16586 This will allow for additional cv-qualification of the
16587 pointed-to types if appropriate. */
16589 if (TREE_CODE (TREE_TYPE (arg)) == RECORD_TYPE)
16590 /* The derived-to-base conversion only persists through one
16591 level of pointers. */
16592 strict |= (strict_in & UNIFY_ALLOW_DERIVED);
16594 return unify (tparms, targs, TREE_TYPE (parm),
16595 TREE_TYPE (arg), strict, explain_p);
16598 case REFERENCE_TYPE:
16599 if (TREE_CODE (arg) != REFERENCE_TYPE)
16600 return unify_type_mismatch (explain_p, parm, arg);
16601 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
16602 strict & UNIFY_ALLOW_MORE_CV_QUAL, explain_p);
16605 if (TREE_CODE (arg) != ARRAY_TYPE)
16606 return unify_type_mismatch (explain_p, parm, arg);
16607 if ((TYPE_DOMAIN (parm) == NULL_TREE)
16608 != (TYPE_DOMAIN (arg) == NULL_TREE))
16609 return unify_type_mismatch (explain_p, parm, arg);
16610 if (TYPE_DOMAIN (parm) != NULL_TREE)
16617 /* Our representation of array types uses "N - 1" as the
16618 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
16619 not an integer constant. We cannot unify arbitrarily
16620 complex expressions, so we eliminate the MINUS_EXPRs
16622 parm_max = TYPE_MAX_VALUE (TYPE_DOMAIN (parm));
16623 parm_cst = TREE_CODE (parm_max) == INTEGER_CST;
16626 gcc_assert (TREE_CODE (parm_max) == MINUS_EXPR);
16627 parm_max = TREE_OPERAND (parm_max, 0);
16629 arg_max = TYPE_MAX_VALUE (TYPE_DOMAIN (arg));
16630 arg_cst = TREE_CODE (arg_max) == INTEGER_CST;
16633 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
16634 trying to unify the type of a variable with the type
16635 of a template parameter. For example:
16637 template <unsigned int N>
16638 void f (char (&) [N]);
16645 Here, the type of the ARG will be "int [g(i)]", and
16646 may be a SAVE_EXPR, etc. */
16647 if (TREE_CODE (arg_max) != MINUS_EXPR)
16648 return unify_vla_arg (explain_p, arg);
16649 arg_max = TREE_OPERAND (arg_max, 0);
16652 /* If only one of the bounds used a MINUS_EXPR, compensate
16653 by adding one to the other bound. */
16654 if (parm_cst && !arg_cst)
16655 parm_max = fold_build2_loc (input_location, PLUS_EXPR,
16659 else if (arg_cst && !parm_cst)
16660 arg_max = fold_build2_loc (input_location, PLUS_EXPR,
16665 RECUR_AND_CHECK_FAILURE (tparms, targs, parm_max, arg_max,
16666 UNIFY_ALLOW_INTEGER, explain_p);
16668 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
16669 strict & UNIFY_ALLOW_MORE_CV_QUAL, explain_p);
16676 case ENUMERAL_TYPE:
16679 if (TREE_CODE (arg) != TREE_CODE (parm))
16680 return unify_type_mismatch (explain_p, parm, arg);
16682 /* We have already checked cv-qualification at the top of the
16684 if (!same_type_ignoring_top_level_qualifiers_p (arg, parm))
16685 return unify_type_mismatch (explain_p, parm, arg);
16687 /* As far as unification is concerned, this wins. Later checks
16688 will invalidate it if necessary. */
16689 return unify_success (explain_p);
16691 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
16692 /* Type INTEGER_CST can come from ordinary constant template args. */
16694 while (TREE_CODE (arg) == NOP_EXPR)
16695 arg = TREE_OPERAND (arg, 0);
16697 if (TREE_CODE (arg) != INTEGER_CST)
16698 return unify_template_argument_mismatch (explain_p, parm, arg);
16699 return (tree_int_cst_equal (parm, arg)
16700 ? unify_success (explain_p)
16701 : unify_template_argument_mismatch (explain_p, parm, arg));
16705 int i, len, argslen;
16706 int parm_variadic_p = 0;
16708 if (TREE_CODE (arg) != TREE_VEC)
16709 return unify_template_argument_mismatch (explain_p, parm, arg);
16711 len = TREE_VEC_LENGTH (parm);
16712 argslen = TREE_VEC_LENGTH (arg);
16714 /* Check for pack expansions in the parameters. */
16715 for (i = 0; i < len; ++i)
16717 if (PACK_EXPANSION_P (TREE_VEC_ELT (parm, i)))
16720 /* We can unify against something with a trailing
16722 parm_variadic_p = 1;
16724 /* [temp.deduct.type]/9: If the template argument list of
16725 P contains a pack expansion that is not the last
16726 template argument, the entire template argument list
16727 is a non-deduced context. */
16728 return unify_success (explain_p);
16732 /* If we don't have enough arguments to satisfy the parameters
16733 (not counting the pack expression at the end), or we have
16734 too many arguments for a parameter list that doesn't end in
16735 a pack expression, we can't unify. */
16736 if (parm_variadic_p
16737 ? argslen < len - parm_variadic_p
16739 return unify_arity (explain_p, TREE_VEC_LENGTH (arg), len);
16741 /* Unify all of the parameters that precede the (optional)
16742 pack expression. */
16743 for (i = 0; i < len - parm_variadic_p; ++i)
16745 RECUR_AND_CHECK_FAILURE (tparms, targs,
16746 TREE_VEC_ELT (parm, i),
16747 TREE_VEC_ELT (arg, i),
16748 UNIFY_ALLOW_NONE, explain_p);
16750 if (parm_variadic_p)
16751 return unify_pack_expansion (tparms, targs, parm, arg,
16753 /*subr=*/true, explain_p);
16754 return unify_success (explain_p);
16759 if (TREE_CODE (arg) != TREE_CODE (parm))
16760 return unify_type_mismatch (explain_p, parm, arg);
16762 if (TYPE_PTRMEMFUNC_P (parm))
16764 if (!TYPE_PTRMEMFUNC_P (arg))
16765 return unify_type_mismatch (explain_p, parm, arg);
16767 return unify (tparms, targs,
16768 TYPE_PTRMEMFUNC_FN_TYPE (parm),
16769 TYPE_PTRMEMFUNC_FN_TYPE (arg),
16770 strict, explain_p);
16773 if (CLASSTYPE_TEMPLATE_INFO (parm))
16775 tree t = NULL_TREE;
16777 if (strict_in & UNIFY_ALLOW_DERIVED)
16779 /* First, we try to unify the PARM and ARG directly. */
16780 t = try_class_unification (tparms, targs,
16781 parm, arg, explain_p);
16785 /* Fallback to the special case allowed in
16786 [temp.deduct.call]:
16788 If P is a class, and P has the form
16789 template-id, then A can be a derived class of
16790 the deduced A. Likewise, if P is a pointer to
16791 a class of the form template-id, A can be a
16792 pointer to a derived class pointed to by the
16794 enum template_base_result r;
16795 r = get_template_base (tparms, targs, parm, arg,
16799 return unify_no_common_base (explain_p, r, parm, arg);
16802 else if (CLASSTYPE_TEMPLATE_INFO (arg)
16803 && (CLASSTYPE_TI_TEMPLATE (parm)
16804 == CLASSTYPE_TI_TEMPLATE (arg)))
16805 /* Perhaps PARM is something like S<U> and ARG is S<int>.
16806 Then, we should unify `int' and `U'. */
16809 /* There's no chance of unification succeeding. */
16810 return unify_type_mismatch (explain_p, parm, arg);
16812 return unify (tparms, targs, CLASSTYPE_TI_ARGS (parm),
16813 CLASSTYPE_TI_ARGS (t), UNIFY_ALLOW_NONE, explain_p);
16815 else if (!same_type_ignoring_top_level_qualifiers_p (parm, arg))
16816 return unify_type_mismatch (explain_p, parm, arg);
16817 return unify_success (explain_p);
16820 case FUNCTION_TYPE:
16822 unsigned int nargs;
16827 if (TREE_CODE (arg) != TREE_CODE (parm))
16828 return unify_type_mismatch (explain_p, parm, arg);
16830 /* CV qualifications for methods can never be deduced, they must
16831 match exactly. We need to check them explicitly here,
16832 because type_unification_real treats them as any other
16833 cv-qualified parameter. */
16834 if (TREE_CODE (parm) == METHOD_TYPE
16835 && (!check_cv_quals_for_unify
16837 class_of_this_parm (arg),
16838 class_of_this_parm (parm))))
16839 return unify_cv_qual_mismatch (explain_p, parm, arg);
16841 RECUR_AND_CHECK_FAILURE (tparms, targs, TREE_TYPE (parm),
16842 TREE_TYPE (arg), UNIFY_ALLOW_NONE, explain_p);
16844 nargs = list_length (TYPE_ARG_TYPES (arg));
16845 args = XALLOCAVEC (tree, nargs);
16846 for (a = TYPE_ARG_TYPES (arg), i = 0;
16847 a != NULL_TREE && a != void_list_node;
16848 a = TREE_CHAIN (a), ++i)
16849 args[i] = TREE_VALUE (a);
16852 return type_unification_real (tparms, targs, TYPE_ARG_TYPES (parm),
16853 args, nargs, 1, DEDUCE_EXACT,
16854 LOOKUP_NORMAL, explain_p);
16858 /* Unify a pointer to member with a pointer to member function, which
16859 deduces the type of the member as a function type. */
16860 if (TYPE_PTRMEMFUNC_P (arg))
16865 /* Check top-level cv qualifiers */
16866 if (!check_cv_quals_for_unify (UNIFY_ALLOW_NONE, arg, parm))
16867 return unify_cv_qual_mismatch (explain_p, parm, arg);
16869 RECUR_AND_CHECK_FAILURE (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
16870 TYPE_PTRMEMFUNC_OBJECT_TYPE (arg),
16871 UNIFY_ALLOW_NONE, explain_p);
16873 /* Determine the type of the function we are unifying against. */
16874 method_type = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (arg));
16876 build_function_type (TREE_TYPE (method_type),
16877 TREE_CHAIN (TYPE_ARG_TYPES (method_type)));
16879 /* Extract the cv-qualifiers of the member function from the
16880 implicit object parameter and place them on the function
16881 type to be restored later. */
16882 fntype = apply_memfn_quals (fntype, type_memfn_quals (method_type));
16883 return unify (tparms, targs, TREE_TYPE (parm), fntype, strict, explain_p);
16886 if (TREE_CODE (arg) != OFFSET_TYPE)
16887 return unify_type_mismatch (explain_p, parm, arg);
16888 RECUR_AND_CHECK_FAILURE (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
16889 TYPE_OFFSET_BASETYPE (arg),
16890 UNIFY_ALLOW_NONE, explain_p);
16891 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
16892 strict, explain_p);
16895 if (DECL_TEMPLATE_PARM_P (parm))
16896 return unify (tparms, targs, DECL_INITIAL (parm), arg, strict, explain_p);
16897 if (arg != integral_constant_value (parm))
16898 return unify_template_argument_mismatch (explain_p, parm, arg);
16899 return unify_success (explain_p);
16902 case TEMPLATE_DECL:
16903 /* Matched cases are handled by the ARG == PARM test above. */
16904 return unify_template_argument_mismatch (explain_p, parm, arg);
16907 /* A non-type template parameter that is a variable should be a
16908 an integral constant, in which case, it whould have been
16909 folded into its (constant) value. So we should not be getting
16910 a variable here. */
16911 gcc_unreachable ();
16913 case TYPE_ARGUMENT_PACK:
16914 case NONTYPE_ARGUMENT_PACK:
16915 return unify (tparms, targs, ARGUMENT_PACK_ARGS (parm),
16916 ARGUMENT_PACK_ARGS (arg), strict, explain_p);
16919 case DECLTYPE_TYPE:
16920 case UNDERLYING_TYPE:
16921 /* Cannot deduce anything from TYPEOF_TYPE, DECLTYPE_TYPE,
16922 or UNDERLYING_TYPE nodes. */
16923 return unify_success (explain_p);
16926 /* Unification fails if we hit an error node. */
16927 return unify_invalid (explain_p);
16930 /* An unresolved overload is a nondeduced context. */
16931 if (is_overloaded_fn (parm) || type_unknown_p (parm))
16932 return unify_success (explain_p);
16933 gcc_assert (EXPR_P (parm));
16935 /* We must be looking at an expression. This can happen with
16939 void foo(S<I>, S<I + 2>);
16941 This is a "nondeduced context":
16945 The nondeduced contexts are:
16947 --A type that is a template-id in which one or more of
16948 the template-arguments is an expression that references
16949 a template-parameter.
16951 In these cases, we assume deduction succeeded, but don't
16952 actually infer any unifications. */
16954 if (!uses_template_parms (parm)
16955 && !template_args_equal (parm, arg))
16956 return unify_expression_unequal (explain_p, parm, arg);
16958 return unify_success (explain_p);
16961 #undef RECUR_AND_CHECK_FAILURE
16963 /* Note that DECL can be defined in this translation unit, if
16967 mark_definable (tree decl)
16970 DECL_NOT_REALLY_EXTERN (decl) = 1;
16971 FOR_EACH_CLONE (clone, decl)
16972 DECL_NOT_REALLY_EXTERN (clone) = 1;
16975 /* Called if RESULT is explicitly instantiated, or is a member of an
16976 explicitly instantiated class. */
16979 mark_decl_instantiated (tree result, int extern_p)
16981 SET_DECL_EXPLICIT_INSTANTIATION (result);
16983 /* If this entity has already been written out, it's too late to
16984 make any modifications. */
16985 if (TREE_ASM_WRITTEN (result))
16988 if (TREE_CODE (result) != FUNCTION_DECL)
16989 /* The TREE_PUBLIC flag for function declarations will have been
16990 set correctly by tsubst. */
16991 TREE_PUBLIC (result) = 1;
16993 /* This might have been set by an earlier implicit instantiation. */
16994 DECL_COMDAT (result) = 0;
16997 DECL_NOT_REALLY_EXTERN (result) = 0;
17000 mark_definable (result);
17001 /* Always make artificials weak. */
17002 if (DECL_ARTIFICIAL (result) && flag_weak)
17003 comdat_linkage (result);
17004 /* For WIN32 we also want to put explicit instantiations in
17005 linkonce sections. */
17006 else if (TREE_PUBLIC (result))
17007 maybe_make_one_only (result);
17010 /* If EXTERN_P, then this function will not be emitted -- unless
17011 followed by an explicit instantiation, at which point its linkage
17012 will be adjusted. If !EXTERN_P, then this function will be
17013 emitted here. In neither circumstance do we want
17014 import_export_decl to adjust the linkage. */
17015 DECL_INTERFACE_KNOWN (result) = 1;
17018 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
17019 important template arguments. If any are missing, we check whether
17020 they're important by using error_mark_node for substituting into any
17021 args that were used for partial ordering (the ones between ARGS and END)
17022 and seeing if it bubbles up. */
17025 check_undeduced_parms (tree targs, tree args, tree end)
17027 bool found = false;
17029 for (i = TREE_VEC_LENGTH (targs) - 1; i >= 0; --i)
17030 if (TREE_VEC_ELT (targs, i) == NULL_TREE)
17033 TREE_VEC_ELT (targs, i) = error_mark_node;
17037 for (; args != end; args = TREE_CHAIN (args))
17039 tree substed = tsubst (TREE_VALUE (args), targs, tf_none, NULL_TREE);
17040 if (substed == error_mark_node)
17047 /* Given two function templates PAT1 and PAT2, return:
17049 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
17050 -1 if PAT2 is more specialized than PAT1.
17051 0 if neither is more specialized.
17053 LEN indicates the number of parameters we should consider
17054 (defaulted parameters should not be considered).
17056 The 1998 std underspecified function template partial ordering, and
17057 DR214 addresses the issue. We take pairs of arguments, one from
17058 each of the templates, and deduce them against each other. One of
17059 the templates will be more specialized if all the *other*
17060 template's arguments deduce against its arguments and at least one
17061 of its arguments *does* *not* deduce against the other template's
17062 corresponding argument. Deduction is done as for class templates.
17063 The arguments used in deduction have reference and top level cv
17064 qualifiers removed. Iff both arguments were originally reference
17065 types *and* deduction succeeds in both directions, the template
17066 with the more cv-qualified argument wins for that pairing (if
17067 neither is more cv-qualified, they both are equal). Unlike regular
17068 deduction, after all the arguments have been deduced in this way,
17069 we do *not* verify the deduced template argument values can be
17070 substituted into non-deduced contexts.
17072 The logic can be a bit confusing here, because we look at deduce1 and
17073 targs1 to see if pat2 is at least as specialized, and vice versa; if we
17074 can find template arguments for pat1 to make arg1 look like arg2, that
17075 means that arg2 is at least as specialized as arg1. */
17078 more_specialized_fn (tree pat1, tree pat2, int len)
17080 tree decl1 = DECL_TEMPLATE_RESULT (pat1);
17081 tree decl2 = DECL_TEMPLATE_RESULT (pat2);
17082 tree targs1 = make_tree_vec (DECL_NTPARMS (pat1));
17083 tree targs2 = make_tree_vec (DECL_NTPARMS (pat2));
17084 tree tparms1 = DECL_INNERMOST_TEMPLATE_PARMS (pat1);
17085 tree tparms2 = DECL_INNERMOST_TEMPLATE_PARMS (pat2);
17086 tree args1 = TYPE_ARG_TYPES (TREE_TYPE (decl1));
17087 tree args2 = TYPE_ARG_TYPES (TREE_TYPE (decl2));
17088 tree origs1, origs2;
17089 bool lose1 = false;
17090 bool lose2 = false;
17092 /* Remove the this parameter from non-static member functions. If
17093 one is a non-static member function and the other is not a static
17094 member function, remove the first parameter from that function
17095 also. This situation occurs for operator functions where we
17096 locate both a member function (with this pointer) and non-member
17097 operator (with explicit first operand). */
17098 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl1))
17100 len--; /* LEN is the number of significant arguments for DECL1 */
17101 args1 = TREE_CHAIN (args1);
17102 if (!DECL_STATIC_FUNCTION_P (decl2))
17103 args2 = TREE_CHAIN (args2);
17105 else if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl2))
17107 args2 = TREE_CHAIN (args2);
17108 if (!DECL_STATIC_FUNCTION_P (decl1))
17111 args1 = TREE_CHAIN (args1);
17115 /* If only one is a conversion operator, they are unordered. */
17116 if (DECL_CONV_FN_P (decl1) != DECL_CONV_FN_P (decl2))
17119 /* Consider the return type for a conversion function */
17120 if (DECL_CONV_FN_P (decl1))
17122 args1 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl1)), args1);
17123 args2 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl2)), args2);
17127 processing_template_decl++;
17133 /* Stop when an ellipsis is seen. */
17134 && args1 != NULL_TREE && args2 != NULL_TREE)
17136 tree arg1 = TREE_VALUE (args1);
17137 tree arg2 = TREE_VALUE (args2);
17138 int deduce1, deduce2;
17142 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
17143 && TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
17145 /* When both arguments are pack expansions, we need only
17146 unify the patterns themselves. */
17147 arg1 = PACK_EXPANSION_PATTERN (arg1);
17148 arg2 = PACK_EXPANSION_PATTERN (arg2);
17150 /* This is the last comparison we need to do. */
17154 if (TREE_CODE (arg1) == REFERENCE_TYPE)
17156 arg1 = TREE_TYPE (arg1);
17157 quals1 = cp_type_quals (arg1);
17160 if (TREE_CODE (arg2) == REFERENCE_TYPE)
17162 arg2 = TREE_TYPE (arg2);
17163 quals2 = cp_type_quals (arg2);
17166 if ((quals1 < 0) != (quals2 < 0))
17168 /* Only of the args is a reference, see if we should apply
17169 array/function pointer decay to it. This is not part of
17170 DR214, but is, IMHO, consistent with the deduction rules
17171 for the function call itself, and with our earlier
17172 implementation of the underspecified partial ordering
17173 rules. (nathan). */
17176 switch (TREE_CODE (arg1))
17179 arg1 = TREE_TYPE (arg1);
17181 case FUNCTION_TYPE:
17182 arg1 = build_pointer_type (arg1);
17191 switch (TREE_CODE (arg2))
17194 arg2 = TREE_TYPE (arg2);
17196 case FUNCTION_TYPE:
17197 arg2 = build_pointer_type (arg2);
17206 arg1 = TYPE_MAIN_VARIANT (arg1);
17207 arg2 = TYPE_MAIN_VARIANT (arg2);
17209 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION)
17211 int i, len2 = list_length (args2);
17212 tree parmvec = make_tree_vec (1);
17213 tree argvec = make_tree_vec (len2);
17216 /* Setup the parameter vector, which contains only ARG1. */
17217 TREE_VEC_ELT (parmvec, 0) = arg1;
17219 /* Setup the argument vector, which contains the remaining
17221 for (i = 0; i < len2; i++, ta = TREE_CHAIN (ta))
17222 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
17224 deduce1 = (unify_pack_expansion (tparms1, targs1, parmvec,
17225 argvec, DEDUCE_EXACT,
17226 /*subr=*/true, /*explain_p=*/false)
17229 /* We cannot deduce in the other direction, because ARG1 is
17230 a pack expansion but ARG2 is not. */
17233 else if (TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
17235 int i, len1 = list_length (args1);
17236 tree parmvec = make_tree_vec (1);
17237 tree argvec = make_tree_vec (len1);
17240 /* Setup the parameter vector, which contains only ARG1. */
17241 TREE_VEC_ELT (parmvec, 0) = arg2;
17243 /* Setup the argument vector, which contains the remaining
17245 for (i = 0; i < len1; i++, ta = TREE_CHAIN (ta))
17246 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
17248 deduce2 = (unify_pack_expansion (tparms2, targs2, parmvec,
17249 argvec, DEDUCE_EXACT,
17250 /*subr=*/true, /*explain_p=*/false)
17253 /* We cannot deduce in the other direction, because ARG2 is
17254 a pack expansion but ARG1 is not.*/
17260 /* The normal case, where neither argument is a pack
17262 deduce1 = (unify (tparms1, targs1, arg1, arg2,
17263 UNIFY_ALLOW_NONE, /*explain_p=*/false)
17265 deduce2 = (unify (tparms2, targs2, arg2, arg1,
17266 UNIFY_ALLOW_NONE, /*explain_p=*/false)
17270 /* If we couldn't deduce arguments for tparms1 to make arg1 match
17271 arg2, then arg2 is not as specialized as arg1. */
17277 /* "If, for a given type, deduction succeeds in both directions
17278 (i.e., the types are identical after the transformations above)
17279 and if the type from the argument template is more cv-qualified
17280 than the type from the parameter template (as described above)
17281 that type is considered to be more specialized than the other. If
17282 neither type is more cv-qualified than the other then neither type
17283 is more specialized than the other." */
17285 if (deduce1 && deduce2
17286 && quals1 != quals2 && quals1 >= 0 && quals2 >= 0)
17288 if ((quals1 & quals2) == quals2)
17290 if ((quals1 & quals2) == quals1)
17294 if (lose1 && lose2)
17295 /* We've failed to deduce something in either direction.
17296 These must be unordered. */
17299 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
17300 || TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
17301 /* We have already processed all of the arguments in our
17302 handing of the pack expansion type. */
17305 args1 = TREE_CHAIN (args1);
17306 args2 = TREE_CHAIN (args2);
17309 /* "In most cases, all template parameters must have values in order for
17310 deduction to succeed, but for partial ordering purposes a template
17311 parameter may remain without a value provided it is not used in the
17312 types being used for partial ordering."
17314 Thus, if we are missing any of the targs1 we need to substitute into
17315 origs1, then pat2 is not as specialized as pat1. This can happen when
17316 there is a nondeduced context. */
17317 if (!lose2 && check_undeduced_parms (targs1, origs1, args1))
17319 if (!lose1 && check_undeduced_parms (targs2, origs2, args2))
17322 processing_template_decl--;
17324 /* All things being equal, if the next argument is a pack expansion
17325 for one function but not for the other, prefer the
17326 non-variadic function. FIXME this is bogus; see c++/41958. */
17328 && args1 && TREE_VALUE (args1)
17329 && args2 && TREE_VALUE (args2))
17331 lose1 = TREE_CODE (TREE_VALUE (args1)) == TYPE_PACK_EXPANSION;
17332 lose2 = TREE_CODE (TREE_VALUE (args2)) == TYPE_PACK_EXPANSION;
17335 if (lose1 == lose2)
17343 /* Determine which of two partial specializations is more specialized.
17345 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
17346 to the first partial specialization. The TREE_VALUE is the
17347 innermost set of template parameters for the partial
17348 specialization. PAT2 is similar, but for the second template.
17350 Return 1 if the first partial specialization is more specialized;
17351 -1 if the second is more specialized; 0 if neither is more
17354 See [temp.class.order] for information about determining which of
17355 two templates is more specialized. */
17358 more_specialized_class (tree pat1, tree pat2)
17363 bool any_deductions = false;
17365 tmpl1 = TREE_TYPE (pat1);
17366 tmpl2 = TREE_TYPE (pat2);
17368 /* Just like what happens for functions, if we are ordering between
17369 different class template specializations, we may encounter dependent
17370 types in the arguments, and we need our dependency check functions
17371 to behave correctly. */
17372 ++processing_template_decl;
17373 targs = get_class_bindings (TREE_VALUE (pat1),
17374 CLASSTYPE_TI_ARGS (tmpl1),
17375 CLASSTYPE_TI_ARGS (tmpl2));
17379 any_deductions = true;
17382 targs = get_class_bindings (TREE_VALUE (pat2),
17383 CLASSTYPE_TI_ARGS (tmpl2),
17384 CLASSTYPE_TI_ARGS (tmpl1));
17388 any_deductions = true;
17390 --processing_template_decl;
17392 /* In the case of a tie where at least one of the class templates
17393 has a parameter pack at the end, the template with the most
17394 non-packed parameters wins. */
17397 && (template_args_variadic_p (TREE_PURPOSE (pat1))
17398 || template_args_variadic_p (TREE_PURPOSE (pat2))))
17400 tree args1 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat1));
17401 tree args2 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat2));
17402 int len1 = TREE_VEC_LENGTH (args1);
17403 int len2 = TREE_VEC_LENGTH (args2);
17405 /* We don't count the pack expansion at the end. */
17406 if (template_args_variadic_p (TREE_PURPOSE (pat1)))
17408 if (template_args_variadic_p (TREE_PURPOSE (pat2)))
17413 else if (len1 < len2)
17420 /* Return the template arguments that will produce the function signature
17421 DECL from the function template FN, with the explicit template
17422 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
17423 also match. Return NULL_TREE if no satisfactory arguments could be
17427 get_bindings (tree fn, tree decl, tree explicit_args, bool check_rettype)
17429 int ntparms = DECL_NTPARMS (fn);
17430 tree targs = make_tree_vec (ntparms);
17432 tree decl_arg_types;
17434 unsigned int nargs, ix;
17437 /* Substitute the explicit template arguments into the type of DECL.
17438 The call to fn_type_unification will handle substitution into the
17440 decl_type = TREE_TYPE (decl);
17441 if (explicit_args && uses_template_parms (decl_type))
17444 tree converted_args;
17446 if (DECL_TEMPLATE_INFO (decl))
17447 tmpl = DECL_TI_TEMPLATE (decl);
17449 /* We can get here for some invalid specializations. */
17453 = coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
17454 explicit_args, NULL_TREE,
17456 /*require_all_args=*/false,
17457 /*use_default_args=*/false);
17458 if (converted_args == error_mark_node)
17461 decl_type = tsubst (decl_type, converted_args, tf_none, NULL_TREE);
17462 if (decl_type == error_mark_node)
17466 /* Never do unification on the 'this' parameter. */
17467 decl_arg_types = skip_artificial_parms_for (decl,
17468 TYPE_ARG_TYPES (decl_type));
17470 nargs = list_length (decl_arg_types);
17471 args = XALLOCAVEC (tree, nargs);
17472 for (arg = decl_arg_types, ix = 0;
17473 arg != NULL_TREE && arg != void_list_node;
17474 arg = TREE_CHAIN (arg), ++ix)
17475 args[ix] = TREE_VALUE (arg);
17477 if (fn_type_unification (fn, explicit_args, targs,
17479 (check_rettype || DECL_CONV_FN_P (fn)
17480 ? TREE_TYPE (decl_type) : NULL_TREE),
17481 DEDUCE_EXACT, LOOKUP_NORMAL, /*explain_p=*/false))
17487 /* Return the innermost template arguments that, when applied to a
17488 template specialization whose innermost template parameters are
17489 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
17492 For example, suppose we have:
17494 template <class T, class U> struct S {};
17495 template <class T> struct S<T*, int> {};
17497 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
17498 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
17499 int}. The resulting vector will be {double}, indicating that `T'
17500 is bound to `double'. */
17503 get_class_bindings (tree tparms, tree spec_args, tree args)
17505 int i, ntparms = TREE_VEC_LENGTH (tparms);
17507 tree innermost_deduced_args;
17509 innermost_deduced_args = make_tree_vec (ntparms);
17510 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
17512 deduced_args = copy_node (args);
17513 SET_TMPL_ARGS_LEVEL (deduced_args,
17514 TMPL_ARGS_DEPTH (deduced_args),
17515 innermost_deduced_args);
17518 deduced_args = innermost_deduced_args;
17520 if (unify (tparms, deduced_args,
17521 INNERMOST_TEMPLATE_ARGS (spec_args),
17522 INNERMOST_TEMPLATE_ARGS (args),
17523 UNIFY_ALLOW_NONE, /*explain_p=*/false))
17526 for (i = 0; i < ntparms; ++i)
17527 if (! TREE_VEC_ELT (innermost_deduced_args, i))
17530 /* Verify that nondeduced template arguments agree with the type
17531 obtained from argument deduction.
17535 struct A { typedef int X; };
17536 template <class T, class U> struct C {};
17537 template <class T> struct C<T, typename T::X> {};
17539 Then with the instantiation `C<A, int>', we can deduce that
17540 `T' is `A' but unify () does not check whether `typename T::X'
17542 spec_args = tsubst (spec_args, deduced_args, tf_none, NULL_TREE);
17543 if (spec_args == error_mark_node
17544 /* We only need to check the innermost arguments; the other
17545 arguments will always agree. */
17546 || !comp_template_args (INNERMOST_TEMPLATE_ARGS (spec_args),
17547 INNERMOST_TEMPLATE_ARGS (args)))
17550 /* Now that we have bindings for all of the template arguments,
17551 ensure that the arguments deduced for the template template
17552 parameters have compatible template parameter lists. See the use
17553 of template_template_parm_bindings_ok_p in fn_type_unification
17554 for more information. */
17555 if (!template_template_parm_bindings_ok_p (tparms, deduced_args))
17558 return deduced_args;
17561 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
17562 Return the TREE_LIST node with the most specialized template, if
17563 any. If there is no most specialized template, the error_mark_node
17566 Note that this function does not look at, or modify, the
17567 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
17568 returned is one of the elements of INSTANTIATIONS, callers may
17569 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
17570 and retrieve it from the value returned. */
17573 most_specialized_instantiation (tree templates)
17577 ++processing_template_decl;
17580 for (fn = TREE_CHAIN (templates); fn; fn = TREE_CHAIN (fn))
17584 if (get_bindings (TREE_VALUE (champ),
17585 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
17586 NULL_TREE, /*check_ret=*/true))
17589 if (get_bindings (TREE_VALUE (fn),
17590 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
17591 NULL_TREE, /*check_ret=*/true))
17598 /* Equally specialized, move to next function. If there
17599 is no next function, nothing's most specialized. */
17600 fn = TREE_CHAIN (fn);
17608 /* Now verify that champ is better than everything earlier in the
17609 instantiation list. */
17610 for (fn = templates; fn != champ; fn = TREE_CHAIN (fn))
17611 if (get_bindings (TREE_VALUE (champ),
17612 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
17613 NULL_TREE, /*check_ret=*/true)
17614 || !get_bindings (TREE_VALUE (fn),
17615 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
17616 NULL_TREE, /*check_ret=*/true))
17622 processing_template_decl--;
17625 return error_mark_node;
17630 /* If DECL is a specialization of some template, return the most
17631 general such template. Otherwise, returns NULL_TREE.
17633 For example, given:
17635 template <class T> struct S { template <class U> void f(U); };
17637 if TMPL is `template <class U> void S<int>::f(U)' this will return
17638 the full template. This function will not trace past partial
17639 specializations, however. For example, given in addition:
17641 template <class T> struct S<T*> { template <class U> void f(U); };
17643 if TMPL is `template <class U> void S<int*>::f(U)' this will return
17644 `template <class T> template <class U> S<T*>::f(U)'. */
17647 most_general_template (tree decl)
17649 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
17650 an immediate specialization. */
17651 if (TREE_CODE (decl) == FUNCTION_DECL)
17653 if (DECL_TEMPLATE_INFO (decl)) {
17654 decl = DECL_TI_TEMPLATE (decl);
17656 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
17657 template friend. */
17658 if (TREE_CODE (decl) != TEMPLATE_DECL)
17664 /* Look for more and more general templates. */
17665 while (DECL_TEMPLATE_INFO (decl))
17667 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
17668 (See cp-tree.h for details.) */
17669 if (TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
17672 if (CLASS_TYPE_P (TREE_TYPE (decl))
17673 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)))
17676 /* Stop if we run into an explicitly specialized class template. */
17677 if (!DECL_NAMESPACE_SCOPE_P (decl)
17678 && DECL_CONTEXT (decl)
17679 && CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (decl)))
17682 decl = DECL_TI_TEMPLATE (decl);
17688 /* Return the most specialized of the class template partial
17689 specializations of TMPL which can produce TYPE, a specialization of
17690 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
17691 a _TYPE node corresponding to the partial specialization, while the
17692 TREE_PURPOSE is the set of template arguments that must be
17693 substituted into the TREE_TYPE in order to generate TYPE.
17695 If the choice of partial specialization is ambiguous, a diagnostic
17696 is issued, and the error_mark_node is returned. If there are no
17697 partial specializations of TMPL matching TYPE, then NULL_TREE is
17701 most_specialized_class (tree type, tree tmpl, tsubst_flags_t complain)
17703 tree list = NULL_TREE;
17709 tree outer_args = NULL_TREE;
17711 tmpl = most_general_template (tmpl);
17712 args = CLASSTYPE_TI_ARGS (type);
17714 /* For determining which partial specialization to use, only the
17715 innermost args are interesting. */
17716 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
17718 outer_args = strip_innermost_template_args (args, 1);
17719 args = INNERMOST_TEMPLATE_ARGS (args);
17722 for (t = DECL_TEMPLATE_SPECIALIZATIONS (tmpl); t; t = TREE_CHAIN (t))
17724 tree partial_spec_args;
17726 tree parms = TREE_VALUE (t);
17728 partial_spec_args = CLASSTYPE_TI_ARGS (TREE_TYPE (t));
17730 ++processing_template_decl;
17736 /* Discard the outer levels of args, and then substitute in the
17737 template args from the enclosing class. */
17738 partial_spec_args = INNERMOST_TEMPLATE_ARGS (partial_spec_args);
17739 partial_spec_args = tsubst_template_args
17740 (partial_spec_args, outer_args, tf_none, NULL_TREE);
17742 /* PARMS already refers to just the innermost parms, but the
17743 template parms in partial_spec_args had their levels lowered
17744 by tsubst, so we need to do the same for the parm list. We
17745 can't just tsubst the TREE_VEC itself, as tsubst wants to
17746 treat a TREE_VEC as an argument vector. */
17747 parms = copy_node (parms);
17748 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
17749 TREE_VEC_ELT (parms, i) =
17750 tsubst (TREE_VEC_ELT (parms, i), outer_args, tf_none, NULL_TREE);
17754 partial_spec_args =
17755 coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
17756 add_to_template_args (outer_args,
17757 partial_spec_args),
17759 /*require_all_args=*/true,
17760 /*use_default_args=*/true);
17762 --processing_template_decl;
17764 if (partial_spec_args == error_mark_node)
17765 return error_mark_node;
17767 spec_args = get_class_bindings (parms,
17773 spec_args = add_to_template_args (outer_args, spec_args);
17774 list = tree_cons (spec_args, TREE_VALUE (t), list);
17775 TREE_TYPE (list) = TREE_TYPE (t);
17782 ambiguous_p = false;
17785 t = TREE_CHAIN (t);
17786 for (; t; t = TREE_CHAIN (t))
17788 fate = more_specialized_class (champ, t);
17795 t = TREE_CHAIN (t);
17798 ambiguous_p = true;
17807 for (t = list; t && t != champ; t = TREE_CHAIN (t))
17809 fate = more_specialized_class (champ, t);
17812 ambiguous_p = true;
17820 char *spaces = NULL;
17821 if (!(complain & tf_error))
17822 return error_mark_node;
17823 error ("ambiguous class template instantiation for %q#T", type);
17824 str = ngettext ("candidate is:", "candidates are:", list_length (list));
17825 for (t = list; t; t = TREE_CHAIN (t))
17827 error ("%s %+#T", spaces ? spaces : str, TREE_TYPE (t));
17828 spaces = spaces ? spaces : get_spaces (str);
17831 return error_mark_node;
17837 /* Explicitly instantiate DECL. */
17840 do_decl_instantiation (tree decl, tree storage)
17842 tree result = NULL_TREE;
17845 if (!decl || decl == error_mark_node)
17846 /* An error occurred, for which grokdeclarator has already issued
17847 an appropriate message. */
17849 else if (! DECL_LANG_SPECIFIC (decl))
17851 error ("explicit instantiation of non-template %q#D", decl);
17854 else if (TREE_CODE (decl) == VAR_DECL)
17856 /* There is an asymmetry here in the way VAR_DECLs and
17857 FUNCTION_DECLs are handled by grokdeclarator. In the case of
17858 the latter, the DECL we get back will be marked as a
17859 template instantiation, and the appropriate
17860 DECL_TEMPLATE_INFO will be set up. This does not happen for
17861 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
17862 should handle VAR_DECLs as it currently handles
17864 if (!DECL_CLASS_SCOPE_P (decl))
17866 error ("%qD is not a static data member of a class template", decl);
17869 result = lookup_field (DECL_CONTEXT (decl), DECL_NAME (decl), 0, false);
17870 if (!result || TREE_CODE (result) != VAR_DECL)
17872 error ("no matching template for %qD found", decl);
17875 if (!same_type_p (TREE_TYPE (result), TREE_TYPE (decl)))
17877 error ("type %qT for explicit instantiation %qD does not match "
17878 "declared type %qT", TREE_TYPE (result), decl,
17883 else if (TREE_CODE (decl) != FUNCTION_DECL)
17885 error ("explicit instantiation of %q#D", decl);
17891 /* Check for various error cases. Note that if the explicit
17892 instantiation is valid the RESULT will currently be marked as an
17893 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
17894 until we get here. */
17896 if (DECL_TEMPLATE_SPECIALIZATION (result))
17898 /* DR 259 [temp.spec].
17900 Both an explicit instantiation and a declaration of an explicit
17901 specialization shall not appear in a program unless the explicit
17902 instantiation follows a declaration of the explicit specialization.
17904 For a given set of template parameters, if an explicit
17905 instantiation of a template appears after a declaration of an
17906 explicit specialization for that template, the explicit
17907 instantiation has no effect. */
17910 else if (DECL_EXPLICIT_INSTANTIATION (result))
17914 No program shall explicitly instantiate any template more
17917 We check DECL_NOT_REALLY_EXTERN so as not to complain when
17918 the first instantiation was `extern' and the second is not,
17919 and EXTERN_P for the opposite case. */
17920 if (DECL_NOT_REALLY_EXTERN (result) && !extern_p)
17921 permerror (input_location, "duplicate explicit instantiation of %q#D", result);
17922 /* If an "extern" explicit instantiation follows an ordinary
17923 explicit instantiation, the template is instantiated. */
17927 else if (!DECL_IMPLICIT_INSTANTIATION (result))
17929 error ("no matching template for %qD found", result);
17932 else if (!DECL_TEMPLATE_INFO (result))
17934 permerror (input_location, "explicit instantiation of non-template %q#D", result);
17938 if (storage == NULL_TREE)
17940 else if (storage == ridpointers[(int) RID_EXTERN])
17942 if (!in_system_header && (cxx_dialect == cxx98))
17943 pedwarn (input_location, OPT_pedantic,
17944 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
17949 error ("storage class %qD applied to template instantiation", storage);
17951 check_explicit_instantiation_namespace (result);
17952 mark_decl_instantiated (result, extern_p);
17954 instantiate_decl (result, /*defer_ok=*/1,
17955 /*expl_inst_class_mem_p=*/false);
17959 mark_class_instantiated (tree t, int extern_p)
17961 SET_CLASSTYPE_EXPLICIT_INSTANTIATION (t);
17962 SET_CLASSTYPE_INTERFACE_KNOWN (t);
17963 CLASSTYPE_INTERFACE_ONLY (t) = extern_p;
17964 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (t)) = extern_p;
17967 CLASSTYPE_DEBUG_REQUESTED (t) = 1;
17968 rest_of_type_compilation (t, 1);
17972 /* Called from do_type_instantiation through binding_table_foreach to
17973 do recursive instantiation for the type bound in ENTRY. */
17975 bt_instantiate_type_proc (binding_entry entry, void *data)
17977 tree storage = *(tree *) data;
17979 if (MAYBE_CLASS_TYPE_P (entry->type)
17980 && !uses_template_parms (CLASSTYPE_TI_ARGS (entry->type)))
17981 do_type_instantiation (TYPE_MAIN_DECL (entry->type), storage, 0);
17984 /* Called from do_type_instantiation to instantiate a member
17985 (a member function or a static member variable) of an
17986 explicitly instantiated class template. */
17988 instantiate_class_member (tree decl, int extern_p)
17990 mark_decl_instantiated (decl, extern_p);
17992 instantiate_decl (decl, /*defer_ok=*/1,
17993 /*expl_inst_class_mem_p=*/true);
17996 /* Perform an explicit instantiation of template class T. STORAGE, if
17997 non-null, is the RID for extern, inline or static. COMPLAIN is
17998 nonzero if this is called from the parser, zero if called recursively,
17999 since the standard is unclear (as detailed below). */
18002 do_type_instantiation (tree t, tree storage, tsubst_flags_t complain)
18007 int previous_instantiation_extern_p = 0;
18009 if (TREE_CODE (t) == TYPE_DECL)
18012 if (! CLASS_TYPE_P (t) || ! CLASSTYPE_TEMPLATE_INFO (t))
18015 (TYPE_TEMPLATE_INFO (t)) ? TYPE_TI_TEMPLATE (t) : NULL;
18017 error ("explicit instantiation of non-class template %qD", tmpl);
18019 error ("explicit instantiation of non-template type %qT", t);
18025 if (!COMPLETE_TYPE_P (t))
18027 if (complain & tf_error)
18028 error ("explicit instantiation of %q#T before definition of template",
18033 if (storage != NULL_TREE)
18035 if (!in_system_header)
18037 if (storage == ridpointers[(int) RID_EXTERN])
18039 if (cxx_dialect == cxx98)
18040 pedwarn (input_location, OPT_pedantic,
18041 "ISO C++ 1998 forbids the use of %<extern%> on "
18042 "explicit instantiations");
18045 pedwarn (input_location, OPT_pedantic,
18046 "ISO C++ forbids the use of %qE"
18047 " on explicit instantiations", storage);
18050 if (storage == ridpointers[(int) RID_INLINE])
18052 else if (storage == ridpointers[(int) RID_EXTERN])
18054 else if (storage == ridpointers[(int) RID_STATIC])
18058 error ("storage class %qD applied to template instantiation",
18064 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (t))
18066 /* DR 259 [temp.spec].
18068 Both an explicit instantiation and a declaration of an explicit
18069 specialization shall not appear in a program unless the explicit
18070 instantiation follows a declaration of the explicit specialization.
18072 For a given set of template parameters, if an explicit
18073 instantiation of a template appears after a declaration of an
18074 explicit specialization for that template, the explicit
18075 instantiation has no effect. */
18078 else if (CLASSTYPE_EXPLICIT_INSTANTIATION (t))
18082 No program shall explicitly instantiate any template more
18085 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
18086 instantiation was `extern'. If EXTERN_P then the second is.
18087 These cases are OK. */
18088 previous_instantiation_extern_p = CLASSTYPE_INTERFACE_ONLY (t);
18090 if (!previous_instantiation_extern_p && !extern_p
18091 && (complain & tf_error))
18092 permerror (input_location, "duplicate explicit instantiation of %q#T", t);
18094 /* If we've already instantiated the template, just return now. */
18095 if (!CLASSTYPE_INTERFACE_ONLY (t))
18099 check_explicit_instantiation_namespace (TYPE_NAME (t));
18100 mark_class_instantiated (t, extern_p);
18108 /* In contrast to implicit instantiation, where only the
18109 declarations, and not the definitions, of members are
18110 instantiated, we have here:
18114 The explicit instantiation of a class template specialization
18115 implies the instantiation of all of its members not
18116 previously explicitly specialized in the translation unit
18117 containing the explicit instantiation.
18119 Of course, we can't instantiate member template classes, since
18120 we don't have any arguments for them. Note that the standard
18121 is unclear on whether the instantiation of the members are
18122 *explicit* instantiations or not. However, the most natural
18123 interpretation is that it should be an explicit instantiation. */
18126 for (tmp = TYPE_METHODS (t); tmp; tmp = DECL_CHAIN (tmp))
18127 if (TREE_CODE (tmp) == FUNCTION_DECL
18128 && DECL_TEMPLATE_INSTANTIATION (tmp))
18129 instantiate_class_member (tmp, extern_p);
18131 for (tmp = TYPE_FIELDS (t); tmp; tmp = DECL_CHAIN (tmp))
18132 if (TREE_CODE (tmp) == VAR_DECL && DECL_TEMPLATE_INSTANTIATION (tmp))
18133 instantiate_class_member (tmp, extern_p);
18135 if (CLASSTYPE_NESTED_UTDS (t))
18136 binding_table_foreach (CLASSTYPE_NESTED_UTDS (t),
18137 bt_instantiate_type_proc, &storage);
18141 /* Given a function DECL, which is a specialization of TMPL, modify
18142 DECL to be a re-instantiation of TMPL with the same template
18143 arguments. TMPL should be the template into which tsubst'ing
18144 should occur for DECL, not the most general template.
18146 One reason for doing this is a scenario like this:
18149 void f(const T&, int i);
18151 void g() { f(3, 7); }
18154 void f(const T& t, const int i) { }
18156 Note that when the template is first instantiated, with
18157 instantiate_template, the resulting DECL will have no name for the
18158 first parameter, and the wrong type for the second. So, when we go
18159 to instantiate the DECL, we regenerate it. */
18162 regenerate_decl_from_template (tree decl, tree tmpl)
18164 /* The arguments used to instantiate DECL, from the most general
18169 args = DECL_TI_ARGS (decl);
18170 code_pattern = DECL_TEMPLATE_RESULT (tmpl);
18172 /* Make sure that we can see identifiers, and compute access
18174 push_access_scope (decl);
18176 if (TREE_CODE (decl) == FUNCTION_DECL)
18184 args_depth = TMPL_ARGS_DEPTH (args);
18185 parms_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
18186 if (args_depth > parms_depth)
18187 args = get_innermost_template_args (args, parms_depth);
18189 specs = tsubst_exception_specification (TREE_TYPE (code_pattern),
18190 args, tf_error, NULL_TREE,
18191 /*defer_ok*/false);
18192 if (specs && specs != error_mark_node)
18193 TREE_TYPE (decl) = build_exception_variant (TREE_TYPE (decl),
18196 /* Merge parameter declarations. */
18197 decl_parm = skip_artificial_parms_for (decl,
18198 DECL_ARGUMENTS (decl));
18200 = skip_artificial_parms_for (code_pattern,
18201 DECL_ARGUMENTS (code_pattern));
18202 while (decl_parm && !FUNCTION_PARAMETER_PACK_P (pattern_parm))
18207 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
18208 DECL_NAME (decl_parm) = DECL_NAME (pattern_parm);
18209 parm_type = tsubst (TREE_TYPE (pattern_parm), args, tf_error,
18211 parm_type = type_decays_to (parm_type);
18212 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
18213 TREE_TYPE (decl_parm) = parm_type;
18214 attributes = DECL_ATTRIBUTES (pattern_parm);
18215 if (DECL_ATTRIBUTES (decl_parm) != attributes)
18217 DECL_ATTRIBUTES (decl_parm) = attributes;
18218 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
18220 decl_parm = DECL_CHAIN (decl_parm);
18221 pattern_parm = DECL_CHAIN (pattern_parm);
18223 /* Merge any parameters that match with the function parameter
18225 if (pattern_parm && FUNCTION_PARAMETER_PACK_P (pattern_parm))
18228 tree expanded_types;
18229 /* Expand the TYPE_PACK_EXPANSION that provides the types for
18230 the parameters in this function parameter pack. */
18231 expanded_types = tsubst_pack_expansion (TREE_TYPE (pattern_parm),
18232 args, tf_error, NULL_TREE);
18233 len = TREE_VEC_LENGTH (expanded_types);
18234 for (i = 0; i < len; i++)
18239 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
18240 /* Rename the parameter to include the index. */
18241 DECL_NAME (decl_parm) =
18242 make_ith_pack_parameter_name (DECL_NAME (pattern_parm), i);
18243 parm_type = TREE_VEC_ELT (expanded_types, i);
18244 parm_type = type_decays_to (parm_type);
18245 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
18246 TREE_TYPE (decl_parm) = parm_type;
18247 attributes = DECL_ATTRIBUTES (pattern_parm);
18248 if (DECL_ATTRIBUTES (decl_parm) != attributes)
18250 DECL_ATTRIBUTES (decl_parm) = attributes;
18251 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
18253 decl_parm = DECL_CHAIN (decl_parm);
18256 /* Merge additional specifiers from the CODE_PATTERN. */
18257 if (DECL_DECLARED_INLINE_P (code_pattern)
18258 && !DECL_DECLARED_INLINE_P (decl))
18259 DECL_DECLARED_INLINE_P (decl) = 1;
18261 else if (TREE_CODE (decl) == VAR_DECL)
18263 DECL_INITIAL (decl) =
18264 tsubst_expr (DECL_INITIAL (code_pattern), args,
18265 tf_error, DECL_TI_TEMPLATE (decl),
18266 /*integral_constant_expression_p=*/false);
18267 if (VAR_HAD_UNKNOWN_BOUND (decl))
18268 TREE_TYPE (decl) = tsubst (TREE_TYPE (code_pattern), args,
18269 tf_error, DECL_TI_TEMPLATE (decl));
18272 gcc_unreachable ();
18274 pop_access_scope (decl);
18277 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
18278 substituted to get DECL. */
18281 template_for_substitution (tree decl)
18283 tree tmpl = DECL_TI_TEMPLATE (decl);
18285 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
18286 for the instantiation. This is not always the most general
18287 template. Consider, for example:
18290 struct S { template <class U> void f();
18291 template <> void f<int>(); };
18293 and an instantiation of S<double>::f<int>. We want TD to be the
18294 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
18295 while (/* An instantiation cannot have a definition, so we need a
18296 more general template. */
18297 DECL_TEMPLATE_INSTANTIATION (tmpl)
18298 /* We must also deal with friend templates. Given:
18300 template <class T> struct S {
18301 template <class U> friend void f() {};
18304 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
18305 so far as the language is concerned, but that's still
18306 where we get the pattern for the instantiation from. On
18307 other hand, if the definition comes outside the class, say:
18309 template <class T> struct S {
18310 template <class U> friend void f();
18312 template <class U> friend void f() {}
18314 we don't need to look any further. That's what the check for
18315 DECL_INITIAL is for. */
18316 || (TREE_CODE (decl) == FUNCTION_DECL
18317 && DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION (tmpl)
18318 && !DECL_INITIAL (DECL_TEMPLATE_RESULT (tmpl))))
18320 /* The present template, TD, should not be a definition. If it
18321 were a definition, we should be using it! Note that we
18322 cannot restructure the loop to just keep going until we find
18323 a template with a definition, since that might go too far if
18324 a specialization was declared, but not defined. */
18325 gcc_assert (TREE_CODE (decl) != VAR_DECL
18326 || DECL_IN_AGGR_P (DECL_TEMPLATE_RESULT (tmpl)));
18328 /* Fetch the more general template. */
18329 tmpl = DECL_TI_TEMPLATE (tmpl);
18335 /* Returns true if we need to instantiate this template instance even if we
18336 know we aren't going to emit it.. */
18339 always_instantiate_p (tree decl)
18341 /* We always instantiate inline functions so that we can inline them. An
18342 explicit instantiation declaration prohibits implicit instantiation of
18343 non-inline functions. With high levels of optimization, we would
18344 normally inline non-inline functions -- but we're not allowed to do
18345 that for "extern template" functions. Therefore, we check
18346 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
18347 return ((TREE_CODE (decl) == FUNCTION_DECL
18348 && DECL_DECLARED_INLINE_P (decl))
18349 /* And we need to instantiate static data members so that
18350 their initializers are available in integral constant
18352 || (TREE_CODE (decl) == VAR_DECL
18353 && decl_maybe_constant_var_p (decl)));
18356 /* If FN has a noexcept-specifier that hasn't been instantiated yet,
18357 instantiate it now, modifying TREE_TYPE (fn). */
18360 maybe_instantiate_noexcept (tree fn)
18362 tree fntype, spec, noex, clone;
18364 if (DECL_CLONED_FUNCTION_P (fn))
18365 fn = DECL_CLONED_FUNCTION (fn);
18366 fntype = TREE_TYPE (fn);
18367 spec = TYPE_RAISES_EXCEPTIONS (fntype);
18369 if (!DEFERRED_NOEXCEPT_SPEC_P (spec))
18372 noex = TREE_PURPOSE (spec);
18374 if (TREE_CODE (noex) == DEFERRED_NOEXCEPT)
18376 if (push_tinst_level (fn))
18378 push_access_scope (fn);
18379 input_location = DECL_SOURCE_LOCATION (fn);
18380 noex = tsubst_copy_and_build (DEFERRED_NOEXCEPT_PATTERN (noex),
18381 DEFERRED_NOEXCEPT_ARGS (noex),
18382 tf_warning_or_error, fn,
18383 /*function_p=*/false,
18384 /*integral_constant_expression_p=*/true);
18385 pop_access_scope (fn);
18386 pop_tinst_level ();
18387 spec = build_noexcept_spec (noex, tf_warning_or_error);
18388 if (spec == error_mark_node)
18389 spec = noexcept_false_spec;
18392 spec = noexcept_false_spec;
18396 /* This is an implicitly declared function, so NOEX is a list of
18397 other functions to evaluate and merge. */
18399 spec = noexcept_true_spec;
18400 for (elt = noex; elt; elt = OVL_NEXT (elt))
18402 tree fn = OVL_CURRENT (elt);
18404 maybe_instantiate_noexcept (fn);
18405 subspec = TYPE_RAISES_EXCEPTIONS (TREE_TYPE (fn));
18406 spec = merge_exception_specifiers (spec, subspec, NULL_TREE);
18410 TREE_TYPE (fn) = build_exception_variant (fntype, spec);
18412 FOR_EACH_CLONE (clone, fn)
18414 if (TREE_TYPE (clone) == fntype)
18415 TREE_TYPE (clone) = TREE_TYPE (fn);
18417 TREE_TYPE (clone) = build_exception_variant (TREE_TYPE (clone), spec);
18421 /* Produce the definition of D, a _DECL generated from a template. If
18422 DEFER_OK is nonzero, then we don't have to actually do the
18423 instantiation now; we just have to do it sometime. Normally it is
18424 an error if this is an explicit instantiation but D is undefined.
18425 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
18426 explicitly instantiated class template. */
18429 instantiate_decl (tree d, int defer_ok,
18430 bool expl_inst_class_mem_p)
18432 tree tmpl = DECL_TI_TEMPLATE (d);
18439 bool pattern_defined;
18441 location_t saved_loc = input_location;
18444 /* This function should only be used to instantiate templates for
18445 functions and static member variables. */
18446 gcc_assert (TREE_CODE (d) == FUNCTION_DECL
18447 || TREE_CODE (d) == VAR_DECL);
18449 /* Variables are never deferred; if instantiation is required, they
18450 are instantiated right away. That allows for better code in the
18451 case that an expression refers to the value of the variable --
18452 if the variable has a constant value the referring expression can
18453 take advantage of that fact. */
18454 if (TREE_CODE (d) == VAR_DECL
18455 || DECL_DECLARED_CONSTEXPR_P (d))
18458 /* Don't instantiate cloned functions. Instead, instantiate the
18459 functions they cloned. */
18460 if (TREE_CODE (d) == FUNCTION_DECL && DECL_CLONED_FUNCTION_P (d))
18461 d = DECL_CLONED_FUNCTION (d);
18463 if (DECL_TEMPLATE_INSTANTIATED (d)
18464 || (TREE_CODE (d) == FUNCTION_DECL
18465 && DECL_DEFAULTED_FN (d) && DECL_INITIAL (d))
18466 || DECL_TEMPLATE_SPECIALIZATION (d))
18467 /* D has already been instantiated or explicitly specialized, so
18468 there's nothing for us to do here.
18470 It might seem reasonable to check whether or not D is an explicit
18471 instantiation, and, if so, stop here. But when an explicit
18472 instantiation is deferred until the end of the compilation,
18473 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
18474 the instantiation. */
18477 /* Check to see whether we know that this template will be
18478 instantiated in some other file, as with "extern template"
18480 external_p = (DECL_INTERFACE_KNOWN (d) && DECL_REALLY_EXTERN (d));
18482 /* In general, we do not instantiate such templates. */
18483 if (external_p && !always_instantiate_p (d))
18486 gen_tmpl = most_general_template (tmpl);
18487 gen_args = DECL_TI_ARGS (d);
18489 if (tmpl != gen_tmpl)
18490 /* We should already have the extra args. */
18491 gcc_assert (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (gen_tmpl))
18492 == TMPL_ARGS_DEPTH (gen_args));
18493 /* And what's in the hash table should match D. */
18494 gcc_assert ((spec = retrieve_specialization (gen_tmpl, gen_args, 0)) == d
18495 || spec == NULL_TREE);
18497 /* This needs to happen before any tsubsting. */
18498 if (! push_tinst_level (d))
18501 timevar_push (TV_TEMPLATE_INST);
18503 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
18504 for the instantiation. */
18505 td = template_for_substitution (d);
18506 code_pattern = DECL_TEMPLATE_RESULT (td);
18508 /* We should never be trying to instantiate a member of a class
18509 template or partial specialization. */
18510 gcc_assert (d != code_pattern);
18512 if ((DECL_NAMESPACE_SCOPE_P (d) && !DECL_INITIALIZED_IN_CLASS_P (d))
18513 || DECL_TEMPLATE_SPECIALIZATION (td))
18514 /* In the case of a friend template whose definition is provided
18515 outside the class, we may have too many arguments. Drop the
18516 ones we don't need. The same is true for specializations. */
18517 args = get_innermost_template_args
18518 (gen_args, TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (td)));
18522 if (TREE_CODE (d) == FUNCTION_DECL)
18523 pattern_defined = (DECL_SAVED_TREE (code_pattern) != NULL_TREE
18524 || DECL_DEFAULTED_OUTSIDE_CLASS_P (code_pattern));
18526 pattern_defined = ! DECL_IN_AGGR_P (code_pattern);
18528 /* We may be in the middle of deferred access check. Disable it now. */
18529 push_deferring_access_checks (dk_no_deferred);
18531 /* Unless an explicit instantiation directive has already determined
18532 the linkage of D, remember that a definition is available for
18534 if (pattern_defined
18535 && !DECL_INTERFACE_KNOWN (d)
18536 && !DECL_NOT_REALLY_EXTERN (d))
18537 mark_definable (d);
18539 DECL_SOURCE_LOCATION (td) = DECL_SOURCE_LOCATION (code_pattern);
18540 DECL_SOURCE_LOCATION (d) = DECL_SOURCE_LOCATION (code_pattern);
18541 input_location = DECL_SOURCE_LOCATION (d);
18543 /* If D is a member of an explicitly instantiated class template,
18544 and no definition is available, treat it like an implicit
18546 if (!pattern_defined && expl_inst_class_mem_p
18547 && DECL_EXPLICIT_INSTANTIATION (d))
18549 /* Leave linkage flags alone on instantiations with anonymous
18551 if (TREE_PUBLIC (d))
18553 DECL_NOT_REALLY_EXTERN (d) = 0;
18554 DECL_INTERFACE_KNOWN (d) = 0;
18556 SET_DECL_IMPLICIT_INSTANTIATION (d);
18559 if (TREE_CODE (d) == FUNCTION_DECL)
18560 maybe_instantiate_noexcept (d);
18562 /* Recheck the substitutions to obtain any warning messages
18563 about ignoring cv qualifiers. Don't do this for artificial decls,
18564 as it breaks the context-sensitive substitution for lambda op(). */
18565 if (!defer_ok && !DECL_ARTIFICIAL (d))
18567 tree gen = DECL_TEMPLATE_RESULT (gen_tmpl);
18568 tree type = TREE_TYPE (gen);
18570 /* Make sure that we can see identifiers, and compute access
18571 correctly. D is already the target FUNCTION_DECL with the
18573 push_access_scope (d);
18575 if (TREE_CODE (gen) == FUNCTION_DECL)
18577 tsubst (DECL_ARGUMENTS (gen), gen_args, tf_warning_or_error, d);
18578 tsubst_exception_specification (type, gen_args, tf_warning_or_error,
18579 d, /*defer_ok*/true);
18580 /* Don't simply tsubst the function type, as that will give
18581 duplicate warnings about poor parameter qualifications.
18582 The function arguments are the same as the decl_arguments
18583 without the top level cv qualifiers. */
18584 type = TREE_TYPE (type);
18586 tsubst (type, gen_args, tf_warning_or_error, d);
18588 pop_access_scope (d);
18591 /* Defer all other templates, unless we have been explicitly
18592 forbidden from doing so. */
18593 if (/* If there is no definition, we cannot instantiate the
18596 /* If it's OK to postpone instantiation, do so. */
18598 /* If this is a static data member that will be defined
18599 elsewhere, we don't want to instantiate the entire data
18600 member, but we do want to instantiate the initializer so that
18601 we can substitute that elsewhere. */
18602 || (external_p && TREE_CODE (d) == VAR_DECL))
18604 /* The definition of the static data member is now required so
18605 we must substitute the initializer. */
18606 if (TREE_CODE (d) == VAR_DECL
18607 && !DECL_INITIAL (d)
18608 && DECL_INITIAL (code_pattern))
18612 bool const_init = false;
18614 ns = decl_namespace_context (d);
18615 push_nested_namespace (ns);
18616 push_nested_class (DECL_CONTEXT (d));
18617 init = tsubst_expr (DECL_INITIAL (code_pattern),
18619 tf_warning_or_error, NULL_TREE,
18620 /*integral_constant_expression_p=*/false);
18621 /* Make sure the initializer is still constant, in case of
18622 circular dependency (template/instantiate6.C). */
18624 = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (code_pattern);
18625 cp_finish_decl (d, init, /*init_const_expr_p=*/const_init,
18626 /*asmspec_tree=*/NULL_TREE,
18627 LOOKUP_ONLYCONVERTING);
18628 pop_nested_class ();
18629 pop_nested_namespace (ns);
18632 /* We restore the source position here because it's used by
18633 add_pending_template. */
18634 input_location = saved_loc;
18636 if (at_eof && !pattern_defined
18637 && DECL_EXPLICIT_INSTANTIATION (d)
18638 && DECL_NOT_REALLY_EXTERN (d))
18641 The definition of a non-exported function template, a
18642 non-exported member function template, or a non-exported
18643 member function or static data member of a class template
18644 shall be present in every translation unit in which it is
18645 explicitly instantiated. */
18646 permerror (input_location, "explicit instantiation of %qD "
18647 "but no definition available", d);
18649 /* If we're in unevaluated context, we just wanted to get the
18650 constant value; this isn't an odr use, so don't queue
18651 a full instantiation. */
18652 if (cp_unevaluated_operand != 0)
18654 /* ??? Historically, we have instantiated inline functions, even
18655 when marked as "extern template". */
18656 if (!(external_p && TREE_CODE (d) == VAR_DECL))
18657 add_pending_template (d);
18660 /* Tell the repository that D is available in this translation unit
18661 -- and see if it is supposed to be instantiated here. */
18662 if (TREE_PUBLIC (d) && !DECL_REALLY_EXTERN (d) && !repo_emit_p (d))
18664 /* In a PCH file, despite the fact that the repository hasn't
18665 requested instantiation in the PCH it is still possible that
18666 an instantiation will be required in a file that includes the
18669 add_pending_template (d);
18670 /* Instantiate inline functions so that the inliner can do its
18671 job, even though we'll not be emitting a copy of this
18673 if (!(TREE_CODE (d) == FUNCTION_DECL && possibly_inlined_p (d)))
18677 need_push = !cfun || !global_bindings_p ();
18679 push_to_top_level ();
18681 /* Mark D as instantiated so that recursive calls to
18682 instantiate_decl do not try to instantiate it again. */
18683 DECL_TEMPLATE_INSTANTIATED (d) = 1;
18685 /* Regenerate the declaration in case the template has been modified
18686 by a subsequent redeclaration. */
18687 regenerate_decl_from_template (d, td);
18689 /* We already set the file and line above. Reset them now in case
18690 they changed as a result of calling regenerate_decl_from_template. */
18691 input_location = DECL_SOURCE_LOCATION (d);
18693 if (TREE_CODE (d) == VAR_DECL)
18696 bool const_init = false;
18698 /* Clear out DECL_RTL; whatever was there before may not be right
18699 since we've reset the type of the declaration. */
18700 SET_DECL_RTL (d, NULL);
18701 DECL_IN_AGGR_P (d) = 0;
18703 /* The initializer is placed in DECL_INITIAL by
18704 regenerate_decl_from_template so we don't need to
18705 push/pop_access_scope again here. Pull it out so that
18706 cp_finish_decl can process it. */
18707 init = DECL_INITIAL (d);
18708 DECL_INITIAL (d) = NULL_TREE;
18709 DECL_INITIALIZED_P (d) = 0;
18711 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
18712 initializer. That function will defer actual emission until
18713 we have a chance to determine linkage. */
18714 DECL_EXTERNAL (d) = 0;
18716 /* Enter the scope of D so that access-checking works correctly. */
18717 push_nested_class (DECL_CONTEXT (d));
18718 const_init = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (code_pattern);
18719 cp_finish_decl (d, init, const_init, NULL_TREE, 0);
18720 pop_nested_class ();
18722 else if (TREE_CODE (d) == FUNCTION_DECL && DECL_DEFAULTED_FN (code_pattern))
18723 synthesize_method (d);
18724 else if (TREE_CODE (d) == FUNCTION_DECL)
18726 htab_t saved_local_specializations;
18731 /* Save away the current list, in case we are instantiating one
18732 template from within the body of another. */
18733 saved_local_specializations = local_specializations;
18735 /* Set up the list of local specializations. */
18736 local_specializations = htab_create (37,
18737 hash_local_specialization,
18738 eq_local_specializations,
18741 /* Set up context. */
18742 start_preparsed_function (d, NULL_TREE, SF_PRE_PARSED);
18744 /* Create substitution entries for the parameters. */
18745 subst_decl = DECL_TEMPLATE_RESULT (template_for_substitution (d));
18746 tmpl_parm = DECL_ARGUMENTS (subst_decl);
18747 spec_parm = DECL_ARGUMENTS (d);
18748 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (d))
18750 register_local_specialization (spec_parm, tmpl_parm);
18751 spec_parm = skip_artificial_parms_for (d, spec_parm);
18752 tmpl_parm = skip_artificial_parms_for (subst_decl, tmpl_parm);
18754 for (; tmpl_parm; tmpl_parm = DECL_CHAIN (tmpl_parm))
18756 if (!FUNCTION_PARAMETER_PACK_P (tmpl_parm))
18758 register_local_specialization (spec_parm, tmpl_parm);
18759 spec_parm = DECL_CHAIN (spec_parm);
18763 /* Register the (value) argument pack as a specialization of
18764 TMPL_PARM, then move on. */
18765 tree argpack = extract_fnparm_pack (tmpl_parm, &spec_parm);
18766 register_local_specialization (argpack, tmpl_parm);
18769 gcc_assert (!spec_parm);
18771 /* Substitute into the body of the function. */
18772 tsubst_expr (DECL_SAVED_TREE (code_pattern), args,
18773 tf_warning_or_error, tmpl,
18774 /*integral_constant_expression_p=*/false);
18776 /* Set the current input_location to the end of the function
18777 so that finish_function knows where we are. */
18778 input_location = DECL_STRUCT_FUNCTION (code_pattern)->function_end_locus;
18780 /* We don't need the local specializations any more. */
18781 htab_delete (local_specializations);
18782 local_specializations = saved_local_specializations;
18784 /* Finish the function. */
18785 d = finish_function (0);
18786 expand_or_defer_fn (d);
18789 /* We're not deferring instantiation any more. */
18790 TI_PENDING_TEMPLATE_FLAG (DECL_TEMPLATE_INFO (d)) = 0;
18793 pop_from_top_level ();
18796 input_location = saved_loc;
18797 pop_deferring_access_checks ();
18798 pop_tinst_level ();
18800 timevar_pop (TV_TEMPLATE_INST);
18805 /* Run through the list of templates that we wish we could
18806 instantiate, and instantiate any we can. RETRIES is the
18807 number of times we retry pending template instantiation. */
18810 instantiate_pending_templates (int retries)
18813 location_t saved_loc = input_location;
18815 /* Instantiating templates may trigger vtable generation. This in turn
18816 may require further template instantiations. We place a limit here
18817 to avoid infinite loop. */
18818 if (pending_templates && retries >= max_tinst_depth)
18820 tree decl = pending_templates->tinst->decl;
18822 error ("template instantiation depth exceeds maximum of %d"
18823 " instantiating %q+D, possibly from virtual table generation"
18824 " (use -ftemplate-depth= to increase the maximum)",
18825 max_tinst_depth, decl);
18826 if (TREE_CODE (decl) == FUNCTION_DECL)
18827 /* Pretend that we defined it. */
18828 DECL_INITIAL (decl) = error_mark_node;
18834 struct pending_template **t = &pending_templates;
18835 struct pending_template *last = NULL;
18839 tree instantiation = reopen_tinst_level ((*t)->tinst);
18840 bool complete = false;
18842 if (TYPE_P (instantiation))
18846 if (!COMPLETE_TYPE_P (instantiation))
18848 instantiate_class_template (instantiation);
18849 if (CLASSTYPE_TEMPLATE_INSTANTIATION (instantiation))
18850 for (fn = TYPE_METHODS (instantiation);
18852 fn = TREE_CHAIN (fn))
18853 if (! DECL_ARTIFICIAL (fn))
18854 instantiate_decl (fn,
18856 /*expl_inst_class_mem_p=*/false);
18857 if (COMPLETE_TYPE_P (instantiation))
18861 complete = COMPLETE_TYPE_P (instantiation);
18865 if (!DECL_TEMPLATE_SPECIALIZATION (instantiation)
18866 && !DECL_TEMPLATE_INSTANTIATED (instantiation))
18869 = instantiate_decl (instantiation,
18871 /*expl_inst_class_mem_p=*/false);
18872 if (DECL_TEMPLATE_INSTANTIATED (instantiation))
18876 complete = (DECL_TEMPLATE_SPECIALIZATION (instantiation)
18877 || DECL_TEMPLATE_INSTANTIATED (instantiation));
18881 /* If INSTANTIATION has been instantiated, then we don't
18882 need to consider it again in the future. */
18890 current_tinst_level = NULL;
18892 last_pending_template = last;
18894 while (reconsider);
18896 input_location = saved_loc;
18899 /* Substitute ARGVEC into T, which is a list of initializers for
18900 either base class or a non-static data member. The TREE_PURPOSEs
18901 are DECLs, and the TREE_VALUEs are the initializer values. Used by
18902 instantiate_decl. */
18905 tsubst_initializer_list (tree t, tree argvec)
18907 tree inits = NULL_TREE;
18909 for (; t; t = TREE_CHAIN (t))
18913 tree expanded_bases = NULL_TREE;
18914 tree expanded_arguments = NULL_TREE;
18917 if (TREE_CODE (TREE_PURPOSE (t)) == TYPE_PACK_EXPANSION)
18922 /* Expand the base class expansion type into separate base
18924 expanded_bases = tsubst_pack_expansion (TREE_PURPOSE (t), argvec,
18925 tf_warning_or_error,
18927 if (expanded_bases == error_mark_node)
18930 /* We'll be building separate TREE_LISTs of arguments for
18932 len = TREE_VEC_LENGTH (expanded_bases);
18933 expanded_arguments = make_tree_vec (len);
18934 for (i = 0; i < len; i++)
18935 TREE_VEC_ELT (expanded_arguments, i) = NULL_TREE;
18937 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
18938 expand each argument in the TREE_VALUE of t. */
18939 expr = make_node (EXPR_PACK_EXPANSION);
18940 PACK_EXPANSION_LOCAL_P (expr) = true;
18941 PACK_EXPANSION_PARAMETER_PACKS (expr) =
18942 PACK_EXPANSION_PARAMETER_PACKS (TREE_PURPOSE (t));
18944 if (TREE_VALUE (t) == void_type_node)
18945 /* VOID_TYPE_NODE is used to indicate
18946 value-initialization. */
18948 for (i = 0; i < len; i++)
18949 TREE_VEC_ELT (expanded_arguments, i) = void_type_node;
18953 /* Substitute parameter packs into each argument in the
18955 in_base_initializer = 1;
18956 for (arg = TREE_VALUE (t); arg; arg = TREE_CHAIN (arg))
18958 tree expanded_exprs;
18960 /* Expand the argument. */
18961 SET_PACK_EXPANSION_PATTERN (expr, TREE_VALUE (arg));
18963 = tsubst_pack_expansion (expr, argvec,
18964 tf_warning_or_error,
18966 if (expanded_exprs == error_mark_node)
18969 /* Prepend each of the expanded expressions to the
18970 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
18971 for (i = 0; i < len; i++)
18973 TREE_VEC_ELT (expanded_arguments, i) =
18974 tree_cons (NULL_TREE,
18975 TREE_VEC_ELT (expanded_exprs, i),
18976 TREE_VEC_ELT (expanded_arguments, i));
18979 in_base_initializer = 0;
18981 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
18982 since we built them backwards. */
18983 for (i = 0; i < len; i++)
18985 TREE_VEC_ELT (expanded_arguments, i) =
18986 nreverse (TREE_VEC_ELT (expanded_arguments, i));
18991 for (i = 0; i < len; ++i)
18993 if (expanded_bases)
18995 decl = TREE_VEC_ELT (expanded_bases, i);
18996 decl = expand_member_init (decl);
18997 init = TREE_VEC_ELT (expanded_arguments, i);
19002 decl = tsubst_copy (TREE_PURPOSE (t), argvec,
19003 tf_warning_or_error, NULL_TREE);
19005 decl = expand_member_init (decl);
19006 if (decl && !DECL_P (decl))
19007 in_base_initializer = 1;
19009 init = TREE_VALUE (t);
19011 if (init != void_type_node)
19012 init = tsubst_expr (init, argvec,
19013 tf_warning_or_error, NULL_TREE,
19014 /*integral_constant_expression_p=*/false);
19015 if (init == NULL_TREE && tmp != NULL_TREE)
19016 /* If we had an initializer but it instantiated to nothing,
19017 value-initialize the object. This will only occur when
19018 the initializer was a pack expansion where the parameter
19019 packs used in that expansion were of length zero. */
19020 init = void_type_node;
19021 in_base_initializer = 0;
19026 init = build_tree_list (decl, init);
19027 TREE_CHAIN (init) = inits;
19035 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
19038 set_current_access_from_decl (tree decl)
19040 if (TREE_PRIVATE (decl))
19041 current_access_specifier = access_private_node;
19042 else if (TREE_PROTECTED (decl))
19043 current_access_specifier = access_protected_node;
19045 current_access_specifier = access_public_node;
19048 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
19049 is the instantiation (which should have been created with
19050 start_enum) and ARGS are the template arguments to use. */
19053 tsubst_enum (tree tag, tree newtag, tree args)
19057 if (SCOPED_ENUM_P (newtag))
19058 begin_scope (sk_scoped_enum, newtag);
19060 for (e = TYPE_VALUES (tag); e; e = TREE_CHAIN (e))
19065 decl = TREE_VALUE (e);
19066 /* Note that in a template enum, the TREE_VALUE is the
19067 CONST_DECL, not the corresponding INTEGER_CST. */
19068 value = tsubst_expr (DECL_INITIAL (decl),
19069 args, tf_warning_or_error, NULL_TREE,
19070 /*integral_constant_expression_p=*/true);
19072 /* Give this enumeration constant the correct access. */
19073 set_current_access_from_decl (decl);
19075 /* Actually build the enumerator itself. */
19077 (DECL_NAME (decl), value, newtag, DECL_SOURCE_LOCATION (decl));
19080 if (SCOPED_ENUM_P (newtag))
19083 finish_enum_value_list (newtag);
19084 finish_enum (newtag);
19086 DECL_SOURCE_LOCATION (TYPE_NAME (newtag))
19087 = DECL_SOURCE_LOCATION (TYPE_NAME (tag));
19090 /* DECL is a FUNCTION_DECL that is a template specialization. Return
19091 its type -- but without substituting the innermost set of template
19092 arguments. So, innermost set of template parameters will appear in
19096 get_mostly_instantiated_function_type (tree decl)
19104 tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
19105 targs = DECL_TI_ARGS (decl);
19106 tparms = DECL_TEMPLATE_PARMS (tmpl);
19107 parm_depth = TMPL_PARMS_DEPTH (tparms);
19109 /* There should be as many levels of arguments as there are levels
19111 gcc_assert (parm_depth == TMPL_ARGS_DEPTH (targs));
19113 fn_type = TREE_TYPE (tmpl);
19115 if (parm_depth == 1)
19116 /* No substitution is necessary. */
19123 /* Replace the innermost level of the TARGS with NULL_TREEs to
19124 let tsubst know not to substitute for those parameters. */
19125 partial_args = make_tree_vec (TREE_VEC_LENGTH (targs));
19126 for (i = 1; i < TMPL_ARGS_DEPTH (targs); ++i)
19127 SET_TMPL_ARGS_LEVEL (partial_args, i,
19128 TMPL_ARGS_LEVEL (targs, i));
19129 SET_TMPL_ARGS_LEVEL (partial_args,
19130 TMPL_ARGS_DEPTH (targs),
19131 make_tree_vec (DECL_NTPARMS (tmpl)));
19133 /* Make sure that we can see identifiers, and compute access
19135 push_access_scope (decl);
19137 ++processing_template_decl;
19138 /* Now, do the (partial) substitution to figure out the
19139 appropriate function type. */
19140 fn_type = tsubst (fn_type, partial_args, tf_error, NULL_TREE);
19141 --processing_template_decl;
19143 /* Substitute into the template parameters to obtain the real
19144 innermost set of parameters. This step is important if the
19145 innermost set of template parameters contains value
19146 parameters whose types depend on outer template parameters. */
19147 TREE_VEC_LENGTH (partial_args)--;
19148 tparms = tsubst_template_parms (tparms, partial_args, tf_error);
19150 pop_access_scope (decl);
19156 /* Return truthvalue if we're processing a template different from
19157 the last one involved in diagnostics. */
19159 problematic_instantiation_changed (void)
19161 return current_tinst_level != last_error_tinst_level;
19164 /* Remember current template involved in diagnostics. */
19166 record_last_problematic_instantiation (void)
19168 last_error_tinst_level = current_tinst_level;
19171 struct tinst_level *
19172 current_instantiation (void)
19174 return current_tinst_level;
19177 /* [temp.param] Check that template non-type parm TYPE is of an allowable
19178 type. Return zero for ok, nonzero for disallowed. Issue error and
19179 warning messages under control of COMPLAIN. */
19182 invalid_nontype_parm_type_p (tree type, tsubst_flags_t complain)
19184 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
19186 else if (POINTER_TYPE_P (type))
19188 else if (TYPE_PTR_TO_MEMBER_P (type))
19190 else if (TREE_CODE (type) == TEMPLATE_TYPE_PARM)
19192 else if (TREE_CODE (type) == TYPENAME_TYPE)
19194 else if (TREE_CODE (type) == DECLTYPE_TYPE)
19196 else if (TREE_CODE (type) == NULLPTR_TYPE)
19199 if (complain & tf_error)
19201 if (type == error_mark_node)
19202 inform (input_location, "invalid template non-type parameter");
19204 error ("%q#T is not a valid type for a template non-type parameter",
19210 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
19211 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
19214 dependent_type_p_r (tree type)
19220 A type is dependent if it is:
19222 -- a template parameter. Template template parameters are types
19223 for us (since TYPE_P holds true for them) so we handle
19225 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
19226 || TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM)
19228 /* -- a qualified-id with a nested-name-specifier which contains a
19229 class-name that names a dependent type or whose unqualified-id
19230 names a dependent type. */
19231 if (TREE_CODE (type) == TYPENAME_TYPE)
19233 /* -- a cv-qualified type where the cv-unqualified type is
19235 type = TYPE_MAIN_VARIANT (type);
19236 /* -- a compound type constructed from any dependent type. */
19237 if (TYPE_PTR_TO_MEMBER_P (type))
19238 return (dependent_type_p (TYPE_PTRMEM_CLASS_TYPE (type))
19239 || dependent_type_p (TYPE_PTRMEM_POINTED_TO_TYPE
19241 else if (TREE_CODE (type) == POINTER_TYPE
19242 || TREE_CODE (type) == REFERENCE_TYPE)
19243 return dependent_type_p (TREE_TYPE (type));
19244 else if (TREE_CODE (type) == FUNCTION_TYPE
19245 || TREE_CODE (type) == METHOD_TYPE)
19249 if (dependent_type_p (TREE_TYPE (type)))
19251 for (arg_type = TYPE_ARG_TYPES (type);
19253 arg_type = TREE_CHAIN (arg_type))
19254 if (dependent_type_p (TREE_VALUE (arg_type)))
19258 /* -- an array type constructed from any dependent type or whose
19259 size is specified by a constant expression that is
19262 We checked for type- and value-dependence of the bounds in
19263 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
19264 if (TREE_CODE (type) == ARRAY_TYPE)
19266 if (TYPE_DOMAIN (type)
19267 && dependent_type_p (TYPE_DOMAIN (type)))
19269 return dependent_type_p (TREE_TYPE (type));
19272 /* -- a template-id in which either the template name is a template
19274 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
19276 /* ... or any of the template arguments is a dependent type or
19277 an expression that is type-dependent or value-dependent. */
19278 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INFO (type)
19279 && (any_dependent_template_arguments_p
19280 (INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type)))))
19283 /* All TYPEOF_TYPEs, DECLTYPE_TYPEs, and UNDERLYING_TYPEs are
19284 dependent; if the argument of the `typeof' expression is not
19285 type-dependent, then it should already been have resolved. */
19286 if (TREE_CODE (type) == TYPEOF_TYPE
19287 || TREE_CODE (type) == DECLTYPE_TYPE
19288 || TREE_CODE (type) == UNDERLYING_TYPE)
19291 /* A template argument pack is dependent if any of its packed
19293 if (TREE_CODE (type) == TYPE_ARGUMENT_PACK)
19295 tree args = ARGUMENT_PACK_ARGS (type);
19296 int i, len = TREE_VEC_LENGTH (args);
19297 for (i = 0; i < len; ++i)
19298 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
19302 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
19303 be template parameters. */
19304 if (TREE_CODE (type) == TYPE_PACK_EXPANSION)
19307 /* The standard does not specifically mention types that are local
19308 to template functions or local classes, but they should be
19309 considered dependent too. For example:
19311 template <int I> void f() {
19316 The size of `E' cannot be known until the value of `I' has been
19317 determined. Therefore, `E' must be considered dependent. */
19318 scope = TYPE_CONTEXT (type);
19319 if (scope && TYPE_P (scope))
19320 return dependent_type_p (scope);
19321 /* Don't use type_dependent_expression_p here, as it can lead
19322 to infinite recursion trying to determine whether a lambda
19323 nested in a lambda is dependent (c++/47687). */
19324 else if (scope && TREE_CODE (scope) == FUNCTION_DECL
19325 && DECL_LANG_SPECIFIC (scope)
19326 && DECL_TEMPLATE_INFO (scope)
19327 && (any_dependent_template_arguments_p
19328 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (scope)))))
19331 /* Other types are non-dependent. */
19335 /* Returns TRUE if TYPE is dependent, in the sense of
19336 [temp.dep.type]. Note that a NULL type is considered dependent. */
19339 dependent_type_p (tree type)
19341 /* If there are no template parameters in scope, then there can't be
19342 any dependent types. */
19343 if (!processing_template_decl)
19345 /* If we are not processing a template, then nobody should be
19346 providing us with a dependent type. */
19348 gcc_assert (TREE_CODE (type) != TEMPLATE_TYPE_PARM || is_auto (type));
19352 /* If the type is NULL, we have not computed a type for the entity
19353 in question; in that case, the type is dependent. */
19357 /* Erroneous types can be considered non-dependent. */
19358 if (type == error_mark_node)
19361 /* If we have not already computed the appropriate value for TYPE,
19363 if (!TYPE_DEPENDENT_P_VALID (type))
19365 TYPE_DEPENDENT_P (type) = dependent_type_p_r (type);
19366 TYPE_DEPENDENT_P_VALID (type) = 1;
19369 return TYPE_DEPENDENT_P (type);
19372 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
19373 lookup. In other words, a dependent type that is not the current
19377 dependent_scope_p (tree scope)
19379 return (scope && TYPE_P (scope) && dependent_type_p (scope)
19380 && !currently_open_class (scope));
19383 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
19384 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
19387 /* Note that this predicate is not appropriate for general expressions;
19388 only constant expressions (that satisfy potential_constant_expression)
19389 can be tested for value dependence.
19391 We should really also have a predicate for "instantiation-dependent".
19393 fold_non_dependent_expr: fold if constant and not type-dependent and not value-dependent.
19394 (what about instantiation-dependent constant-expressions?)
19395 is_late_template_attribute: defer if instantiation-dependent.
19396 compute_array_index_type: proceed if constant and not t- or v-dependent
19397 if instantiation-dependent, need to remember full expression
19398 uses_template_parms: FIXME - need to audit callers
19399 tsubst_decl [function_decl]: Why is this using value_dependent_expression_p?
19400 dependent_type_p [array_type]: dependent if index type is dependent
19402 static_assert - instantiation-dependent */
19405 value_dependent_expression_p (tree expression)
19407 if (!processing_template_decl)
19410 /* A name declared with a dependent type. */
19411 if (DECL_P (expression) && type_dependent_expression_p (expression))
19414 switch (TREE_CODE (expression))
19416 case IDENTIFIER_NODE:
19417 /* A name that has not been looked up -- must be dependent. */
19420 case TEMPLATE_PARM_INDEX:
19421 /* A non-type template parm. */
19425 /* A non-type template parm. */
19426 if (DECL_TEMPLATE_PARM_P (expression))
19428 return value_dependent_expression_p (DECL_INITIAL (expression));
19431 /* A constant with literal type and is initialized
19432 with an expression that is value-dependent. */
19433 if (DECL_INITIAL (expression)
19434 && decl_constant_var_p (expression)
19435 && value_dependent_expression_p (DECL_INITIAL (expression)))
19439 case DYNAMIC_CAST_EXPR:
19440 case STATIC_CAST_EXPR:
19441 case CONST_CAST_EXPR:
19442 case REINTERPRET_CAST_EXPR:
19444 /* These expressions are value-dependent if the type to which
19445 the cast occurs is dependent or the expression being casted
19446 is value-dependent. */
19448 tree type = TREE_TYPE (expression);
19450 if (dependent_type_p (type))
19453 /* A functional cast has a list of operands. */
19454 expression = TREE_OPERAND (expression, 0);
19457 /* If there are no operands, it must be an expression such
19458 as "int()". This should not happen for aggregate types
19459 because it would form non-constant expressions. */
19460 gcc_assert (cxx_dialect >= cxx0x
19461 || INTEGRAL_OR_ENUMERATION_TYPE_P (type));
19466 if (TREE_CODE (expression) == TREE_LIST)
19467 return any_value_dependent_elements_p (expression);
19469 return value_dependent_expression_p (expression);
19475 /* A `sizeof' expression is value-dependent if the operand is
19476 type-dependent or is a pack expansion. */
19477 expression = TREE_OPERAND (expression, 0);
19478 if (PACK_EXPANSION_P (expression))
19480 else if (TYPE_P (expression))
19481 return dependent_type_p (expression);
19482 return type_dependent_expression_p (expression);
19484 case AT_ENCODE_EXPR:
19485 /* An 'encode' expression is value-dependent if the operand is
19487 expression = TREE_OPERAND (expression, 0);
19488 return dependent_type_p (expression);
19490 case NOEXCEPT_EXPR:
19491 expression = TREE_OPERAND (expression, 0);
19492 return type_dependent_expression_p (expression);
19496 tree name = TREE_OPERAND (expression, 1);
19497 return value_dependent_expression_p (name);
19500 case COMPONENT_REF:
19501 return (value_dependent_expression_p (TREE_OPERAND (expression, 0))
19502 || value_dependent_expression_p (TREE_OPERAND (expression, 1)));
19504 case NONTYPE_ARGUMENT_PACK:
19505 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
19506 is value-dependent. */
19508 tree values = ARGUMENT_PACK_ARGS (expression);
19509 int i, len = TREE_VEC_LENGTH (values);
19511 for (i = 0; i < len; ++i)
19512 if (value_dependent_expression_p (TREE_VEC_ELT (values, i)))
19520 tree type2 = TRAIT_EXPR_TYPE2 (expression);
19521 return (dependent_type_p (TRAIT_EXPR_TYPE1 (expression))
19522 || (type2 ? dependent_type_p (type2) : false));
19526 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
19527 || (value_dependent_expression_p (TREE_OPERAND (expression, 2))));
19530 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
19531 || (value_dependent_expression_p (TREE_OPERAND (expression, 1))));
19535 tree op = TREE_OPERAND (expression, 0);
19536 return (value_dependent_expression_p (op)
19537 || has_value_dependent_address (op));
19542 tree fn = get_callee_fndecl (expression);
19544 if (!fn && value_dependent_expression_p (CALL_EXPR_FN (expression)))
19546 nargs = call_expr_nargs (expression);
19547 for (i = 0; i < nargs; ++i)
19549 tree op = CALL_EXPR_ARG (expression, i);
19550 /* In a call to a constexpr member function, look through the
19551 implicit ADDR_EXPR on the object argument so that it doesn't
19552 cause the call to be considered value-dependent. We also
19553 look through it in potential_constant_expression. */
19554 if (i == 0 && fn && DECL_DECLARED_CONSTEXPR_P (fn)
19555 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
19556 && TREE_CODE (op) == ADDR_EXPR)
19557 op = TREE_OPERAND (op, 0);
19558 if (value_dependent_expression_p (op))
19564 case TEMPLATE_ID_EXPR:
19565 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
19567 return type_dependent_expression_p (expression);
19573 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), ix, val)
19574 if (value_dependent_expression_p (val))
19580 /* Treat a GNU statement expression as dependent to avoid crashing
19581 under fold_non_dependent_expr; it can't be constant. */
19585 /* A constant expression is value-dependent if any subexpression is
19586 value-dependent. */
19587 switch (TREE_CODE_CLASS (TREE_CODE (expression)))
19589 case tcc_reference:
19591 case tcc_comparison:
19593 case tcc_expression:
19596 int i, len = cp_tree_operand_length (expression);
19598 for (i = 0; i < len; i++)
19600 tree t = TREE_OPERAND (expression, i);
19602 /* In some cases, some of the operands may be missing.l
19603 (For example, in the case of PREDECREMENT_EXPR, the
19604 amount to increment by may be missing.) That doesn't
19605 make the expression dependent. */
19606 if (t && value_dependent_expression_p (t))
19617 /* The expression is not value-dependent. */
19621 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
19622 [temp.dep.expr]. Note that an expression with no type is
19623 considered dependent. Other parts of the compiler arrange for an
19624 expression with type-dependent subexpressions to have no type, so
19625 this function doesn't have to be fully recursive. */
19628 type_dependent_expression_p (tree expression)
19630 if (!processing_template_decl)
19633 if (expression == error_mark_node)
19636 /* An unresolved name is always dependent. */
19637 if (TREE_CODE (expression) == IDENTIFIER_NODE
19638 || TREE_CODE (expression) == USING_DECL)
19641 /* Some expression forms are never type-dependent. */
19642 if (TREE_CODE (expression) == PSEUDO_DTOR_EXPR
19643 || TREE_CODE (expression) == SIZEOF_EXPR
19644 || TREE_CODE (expression) == ALIGNOF_EXPR
19645 || TREE_CODE (expression) == AT_ENCODE_EXPR
19646 || TREE_CODE (expression) == NOEXCEPT_EXPR
19647 || TREE_CODE (expression) == TRAIT_EXPR
19648 || TREE_CODE (expression) == TYPEID_EXPR
19649 || TREE_CODE (expression) == DELETE_EXPR
19650 || TREE_CODE (expression) == VEC_DELETE_EXPR
19651 || TREE_CODE (expression) == THROW_EXPR)
19654 /* The types of these expressions depends only on the type to which
19655 the cast occurs. */
19656 if (TREE_CODE (expression) == DYNAMIC_CAST_EXPR
19657 || TREE_CODE (expression) == STATIC_CAST_EXPR
19658 || TREE_CODE (expression) == CONST_CAST_EXPR
19659 || TREE_CODE (expression) == REINTERPRET_CAST_EXPR
19660 || TREE_CODE (expression) == IMPLICIT_CONV_EXPR
19661 || TREE_CODE (expression) == CAST_EXPR)
19662 return dependent_type_p (TREE_TYPE (expression));
19664 /* The types of these expressions depends only on the type created
19665 by the expression. */
19666 if (TREE_CODE (expression) == NEW_EXPR
19667 || TREE_CODE (expression) == VEC_NEW_EXPR)
19669 /* For NEW_EXPR tree nodes created inside a template, either
19670 the object type itself or a TREE_LIST may appear as the
19672 tree type = TREE_OPERAND (expression, 1);
19673 if (TREE_CODE (type) == TREE_LIST)
19674 /* This is an array type. We need to check array dimensions
19676 return dependent_type_p (TREE_VALUE (TREE_PURPOSE (type)))
19677 || value_dependent_expression_p
19678 (TREE_OPERAND (TREE_VALUE (type), 1));
19680 return dependent_type_p (type);
19683 if (TREE_CODE (expression) == SCOPE_REF)
19685 tree scope = TREE_OPERAND (expression, 0);
19686 tree name = TREE_OPERAND (expression, 1);
19688 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
19689 contains an identifier associated by name lookup with one or more
19690 declarations declared with a dependent type, or...a
19691 nested-name-specifier or qualified-id that names a member of an
19692 unknown specialization. */
19693 return (type_dependent_expression_p (name)
19694 || dependent_scope_p (scope));
19697 if (TREE_CODE (expression) == FUNCTION_DECL
19698 && DECL_LANG_SPECIFIC (expression)
19699 && DECL_TEMPLATE_INFO (expression)
19700 && (any_dependent_template_arguments_p
19701 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (expression)))))
19704 if (TREE_CODE (expression) == TEMPLATE_DECL
19705 && !DECL_TEMPLATE_TEMPLATE_PARM_P (expression))
19708 if (TREE_CODE (expression) == STMT_EXPR)
19709 expression = stmt_expr_value_expr (expression);
19711 if (BRACE_ENCLOSED_INITIALIZER_P (expression))
19716 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), i, elt)
19718 if (type_dependent_expression_p (elt))
19724 /* A static data member of the current instantiation with incomplete
19725 array type is type-dependent, as the definition and specializations
19726 can have different bounds. */
19727 if (TREE_CODE (expression) == VAR_DECL
19728 && DECL_CLASS_SCOPE_P (expression)
19729 && dependent_type_p (DECL_CONTEXT (expression))
19730 && VAR_HAD_UNKNOWN_BOUND (expression))
19733 if (TREE_TYPE (expression) == unknown_type_node)
19735 if (TREE_CODE (expression) == ADDR_EXPR)
19736 return type_dependent_expression_p (TREE_OPERAND (expression, 0));
19737 if (TREE_CODE (expression) == COMPONENT_REF
19738 || TREE_CODE (expression) == OFFSET_REF)
19740 if (type_dependent_expression_p (TREE_OPERAND (expression, 0)))
19742 expression = TREE_OPERAND (expression, 1);
19743 if (TREE_CODE (expression) == IDENTIFIER_NODE)
19746 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
19747 if (TREE_CODE (expression) == SCOPE_REF)
19750 if (BASELINK_P (expression))
19751 expression = BASELINK_FUNCTIONS (expression);
19753 if (TREE_CODE (expression) == TEMPLATE_ID_EXPR)
19755 if (any_dependent_template_arguments_p
19756 (TREE_OPERAND (expression, 1)))
19758 expression = TREE_OPERAND (expression, 0);
19760 gcc_assert (TREE_CODE (expression) == OVERLOAD
19761 || TREE_CODE (expression) == FUNCTION_DECL);
19765 if (type_dependent_expression_p (OVL_CURRENT (expression)))
19767 expression = OVL_NEXT (expression);
19772 gcc_assert (TREE_CODE (expression) != TYPE_DECL);
19774 return (dependent_type_p (TREE_TYPE (expression)));
19777 /* Like type_dependent_expression_p, but it also works while not processing
19778 a template definition, i.e. during substitution or mangling. */
19781 type_dependent_expression_p_push (tree expr)
19784 ++processing_template_decl;
19785 b = type_dependent_expression_p (expr);
19786 --processing_template_decl;
19790 /* Returns TRUE if ARGS contains a type-dependent expression. */
19793 any_type_dependent_arguments_p (const VEC(tree,gc) *args)
19798 FOR_EACH_VEC_ELT (tree, args, i, arg)
19800 if (type_dependent_expression_p (arg))
19806 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
19807 expressions) contains any type-dependent expressions. */
19810 any_type_dependent_elements_p (const_tree list)
19812 for (; list; list = TREE_CHAIN (list))
19813 if (value_dependent_expression_p (TREE_VALUE (list)))
19819 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
19820 expressions) contains any value-dependent expressions. */
19823 any_value_dependent_elements_p (const_tree list)
19825 for (; list; list = TREE_CHAIN (list))
19826 if (value_dependent_expression_p (TREE_VALUE (list)))
19832 /* Returns TRUE if the ARG (a template argument) is dependent. */
19835 dependent_template_arg_p (tree arg)
19837 if (!processing_template_decl)
19840 /* Assume a template argument that was wrongly written by the user
19841 is dependent. This is consistent with what
19842 any_dependent_template_arguments_p [that calls this function]
19844 if (!arg || arg == error_mark_node)
19847 if (TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
19848 arg = ARGUMENT_PACK_SELECT_ARG (arg);
19850 if (TREE_CODE (arg) == TEMPLATE_DECL
19851 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
19852 return dependent_template_p (arg);
19853 else if (ARGUMENT_PACK_P (arg))
19855 tree args = ARGUMENT_PACK_ARGS (arg);
19856 int i, len = TREE_VEC_LENGTH (args);
19857 for (i = 0; i < len; ++i)
19859 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
19865 else if (TYPE_P (arg))
19866 return dependent_type_p (arg);
19868 return (type_dependent_expression_p (arg)
19869 || value_dependent_expression_p (arg));
19872 /* Returns true if ARGS (a collection of template arguments) contains
19873 any types that require structural equality testing. */
19876 any_template_arguments_need_structural_equality_p (tree args)
19883 if (args == error_mark_node)
19886 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
19888 tree level = TMPL_ARGS_LEVEL (args, i + 1);
19889 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
19891 tree arg = TREE_VEC_ELT (level, j);
19892 tree packed_args = NULL_TREE;
19895 if (ARGUMENT_PACK_P (arg))
19897 /* Look inside the argument pack. */
19898 packed_args = ARGUMENT_PACK_ARGS (arg);
19899 len = TREE_VEC_LENGTH (packed_args);
19902 for (k = 0; k < len; ++k)
19905 arg = TREE_VEC_ELT (packed_args, k);
19907 if (error_operand_p (arg))
19909 else if (TREE_CODE (arg) == TEMPLATE_DECL
19910 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
19912 else if (TYPE_P (arg) && TYPE_STRUCTURAL_EQUALITY_P (arg))
19914 else if (!TYPE_P (arg) && TREE_TYPE (arg)
19915 && TYPE_STRUCTURAL_EQUALITY_P (TREE_TYPE (arg)))
19924 /* Returns true if ARGS (a collection of template arguments) contains
19925 any dependent arguments. */
19928 any_dependent_template_arguments_p (const_tree args)
19935 if (args == error_mark_node)
19938 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
19940 const_tree level = TMPL_ARGS_LEVEL (args, i + 1);
19941 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
19942 if (dependent_template_arg_p (TREE_VEC_ELT (level, j)))
19949 /* Returns TRUE if the template TMPL is dependent. */
19952 dependent_template_p (tree tmpl)
19954 if (TREE_CODE (tmpl) == OVERLOAD)
19958 if (dependent_template_p (OVL_CURRENT (tmpl)))
19960 tmpl = OVL_NEXT (tmpl);
19965 /* Template template parameters are dependent. */
19966 if (DECL_TEMPLATE_TEMPLATE_PARM_P (tmpl)
19967 || TREE_CODE (tmpl) == TEMPLATE_TEMPLATE_PARM)
19969 /* So are names that have not been looked up. */
19970 if (TREE_CODE (tmpl) == SCOPE_REF
19971 || TREE_CODE (tmpl) == IDENTIFIER_NODE)
19973 /* So are member templates of dependent classes. */
19974 if (TYPE_P (CP_DECL_CONTEXT (tmpl)))
19975 return dependent_type_p (DECL_CONTEXT (tmpl));
19979 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
19982 dependent_template_id_p (tree tmpl, tree args)
19984 return (dependent_template_p (tmpl)
19985 || any_dependent_template_arguments_p (args));
19988 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
19992 dependent_omp_for_p (tree declv, tree initv, tree condv, tree incrv)
19996 if (!processing_template_decl)
19999 for (i = 0; i < TREE_VEC_LENGTH (declv); i++)
20001 tree decl = TREE_VEC_ELT (declv, i);
20002 tree init = TREE_VEC_ELT (initv, i);
20003 tree cond = TREE_VEC_ELT (condv, i);
20004 tree incr = TREE_VEC_ELT (incrv, i);
20006 if (type_dependent_expression_p (decl))
20009 if (init && type_dependent_expression_p (init))
20012 if (type_dependent_expression_p (cond))
20015 if (COMPARISON_CLASS_P (cond)
20016 && (type_dependent_expression_p (TREE_OPERAND (cond, 0))
20017 || type_dependent_expression_p (TREE_OPERAND (cond, 1))))
20020 if (TREE_CODE (incr) == MODOP_EXPR)
20022 if (type_dependent_expression_p (TREE_OPERAND (incr, 0))
20023 || type_dependent_expression_p (TREE_OPERAND (incr, 2)))
20026 else if (type_dependent_expression_p (incr))
20028 else if (TREE_CODE (incr) == MODIFY_EXPR)
20030 if (type_dependent_expression_p (TREE_OPERAND (incr, 0)))
20032 else if (BINARY_CLASS_P (TREE_OPERAND (incr, 1)))
20034 tree t = TREE_OPERAND (incr, 1);
20035 if (type_dependent_expression_p (TREE_OPERAND (t, 0))
20036 || type_dependent_expression_p (TREE_OPERAND (t, 1)))
20045 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
20046 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
20047 no such TYPE can be found. Note that this function peers inside
20048 uninstantiated templates and therefore should be used only in
20049 extremely limited situations. ONLY_CURRENT_P restricts this
20050 peering to the currently open classes hierarchy (which is required
20051 when comparing types). */
20054 resolve_typename_type (tree type, bool only_current_p)
20063 gcc_assert (TREE_CODE (type) == TYPENAME_TYPE);
20065 scope = TYPE_CONTEXT (type);
20066 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
20067 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
20068 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
20069 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
20070 identifier of the TYPENAME_TYPE anymore.
20071 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
20072 TYPENAME_TYPE instead, we avoid messing up with a possible
20073 typedef variant case. */
20074 name = TYPE_IDENTIFIER (TYPE_MAIN_VARIANT (type));
20076 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
20077 it first before we can figure out what NAME refers to. */
20078 if (TREE_CODE (scope) == TYPENAME_TYPE)
20079 scope = resolve_typename_type (scope, only_current_p);
20080 /* If we don't know what SCOPE refers to, then we cannot resolve the
20082 if (TREE_CODE (scope) == TYPENAME_TYPE)
20084 /* If the SCOPE is a template type parameter, we have no way of
20085 resolving the name. */
20086 if (TREE_CODE (scope) == TEMPLATE_TYPE_PARM)
20088 /* If the SCOPE is not the current instantiation, there's no reason
20089 to look inside it. */
20090 if (only_current_p && !currently_open_class (scope))
20092 /* If this is a typedef, we don't want to look inside (c++/11987). */
20093 if (typedef_variant_p (type))
20095 /* If SCOPE isn't the template itself, it will not have a valid
20096 TYPE_FIELDS list. */
20097 if (same_type_p (scope, CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope)))
20098 /* scope is either the template itself or a compatible instantiation
20099 like X<T>, so look up the name in the original template. */
20100 scope = CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope);
20102 /* scope is a partial instantiation, so we can't do the lookup or we
20103 will lose the template arguments. */
20105 /* Enter the SCOPE so that name lookup will be resolved as if we
20106 were in the class definition. In particular, SCOPE will no
20107 longer be considered a dependent type. */
20108 pushed_scope = push_scope (scope);
20109 /* Look up the declaration. */
20110 decl = lookup_member (scope, name, /*protect=*/0, /*want_type=*/true,
20111 tf_warning_or_error);
20113 result = NULL_TREE;
20115 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
20116 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
20119 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == IDENTIFIER_NODE
20120 && TREE_CODE (decl) == TYPE_DECL)
20122 result = TREE_TYPE (decl);
20123 if (result == error_mark_node)
20124 result = NULL_TREE;
20126 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == TEMPLATE_ID_EXPR
20127 && DECL_CLASS_TEMPLATE_P (decl))
20131 /* Obtain the template and the arguments. */
20132 tmpl = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 0);
20133 args = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 1);
20134 /* Instantiate the template. */
20135 result = lookup_template_class (tmpl, args, NULL_TREE, NULL_TREE,
20136 /*entering_scope=*/0,
20137 tf_error | tf_user);
20138 if (result == error_mark_node)
20139 result = NULL_TREE;
20142 /* Leave the SCOPE. */
20144 pop_scope (pushed_scope);
20146 /* If we failed to resolve it, return the original typename. */
20150 /* If lookup found a typename type, resolve that too. */
20151 if (TREE_CODE (result) == TYPENAME_TYPE && !TYPENAME_IS_RESOLVING_P (result))
20153 /* Ill-formed programs can cause infinite recursion here, so we
20154 must catch that. */
20155 TYPENAME_IS_RESOLVING_P (type) = 1;
20156 result = resolve_typename_type (result, only_current_p);
20157 TYPENAME_IS_RESOLVING_P (type) = 0;
20160 /* Qualify the resulting type. */
20161 quals = cp_type_quals (type);
20163 result = cp_build_qualified_type (result, cp_type_quals (result) | quals);
20168 /* EXPR is an expression which is not type-dependent. Return a proxy
20169 for EXPR that can be used to compute the types of larger
20170 expressions containing EXPR. */
20173 build_non_dependent_expr (tree expr)
20177 #ifdef ENABLE_CHECKING
20178 /* Try to get a constant value for all non-type-dependent expressions in
20179 order to expose bugs in *_dependent_expression_p and constexpr. */
20180 if (cxx_dialect >= cxx0x)
20181 maybe_constant_value (fold_non_dependent_expr_sfinae (expr, tf_none));
20184 /* Preserve OVERLOADs; the functions must be available to resolve
20187 if (TREE_CODE (inner_expr) == STMT_EXPR)
20188 inner_expr = stmt_expr_value_expr (inner_expr);
20189 if (TREE_CODE (inner_expr) == ADDR_EXPR)
20190 inner_expr = TREE_OPERAND (inner_expr, 0);
20191 if (TREE_CODE (inner_expr) == COMPONENT_REF)
20192 inner_expr = TREE_OPERAND (inner_expr, 1);
20193 if (is_overloaded_fn (inner_expr)
20194 || TREE_CODE (inner_expr) == OFFSET_REF)
20196 /* There is no need to return a proxy for a variable. */
20197 if (TREE_CODE (expr) == VAR_DECL)
20199 /* Preserve string constants; conversions from string constants to
20200 "char *" are allowed, even though normally a "const char *"
20201 cannot be used to initialize a "char *". */
20202 if (TREE_CODE (expr) == STRING_CST)
20204 /* Preserve arithmetic constants, as an optimization -- there is no
20205 reason to create a new node. */
20206 if (TREE_CODE (expr) == INTEGER_CST || TREE_CODE (expr) == REAL_CST)
20208 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
20209 There is at least one place where we want to know that a
20210 particular expression is a throw-expression: when checking a ?:
20211 expression, there are special rules if the second or third
20212 argument is a throw-expression. */
20213 if (TREE_CODE (expr) == THROW_EXPR)
20216 /* Don't wrap an initializer list, we need to be able to look inside. */
20217 if (BRACE_ENCLOSED_INITIALIZER_P (expr))
20220 if (TREE_CODE (expr) == COND_EXPR)
20221 return build3 (COND_EXPR,
20223 TREE_OPERAND (expr, 0),
20224 (TREE_OPERAND (expr, 1)
20225 ? build_non_dependent_expr (TREE_OPERAND (expr, 1))
20226 : build_non_dependent_expr (TREE_OPERAND (expr, 0))),
20227 build_non_dependent_expr (TREE_OPERAND (expr, 2)));
20228 if (TREE_CODE (expr) == COMPOUND_EXPR
20229 && !COMPOUND_EXPR_OVERLOADED (expr))
20230 return build2 (COMPOUND_EXPR,
20232 TREE_OPERAND (expr, 0),
20233 build_non_dependent_expr (TREE_OPERAND (expr, 1)));
20235 /* If the type is unknown, it can't really be non-dependent */
20236 gcc_assert (TREE_TYPE (expr) != unknown_type_node);
20238 /* Otherwise, build a NON_DEPENDENT_EXPR. */
20239 return build1 (NON_DEPENDENT_EXPR, TREE_TYPE (expr), expr);
20242 /* ARGS is a vector of expressions as arguments to a function call.
20243 Replace the arguments with equivalent non-dependent expressions.
20244 This modifies ARGS in place. */
20247 make_args_non_dependent (VEC(tree,gc) *args)
20252 FOR_EACH_VEC_ELT (tree, args, ix, arg)
20254 tree newarg = build_non_dependent_expr (arg);
20256 VEC_replace (tree, args, ix, newarg);
20260 /* Returns a type which represents 'auto'. We use a TEMPLATE_TYPE_PARM
20261 with a level one deeper than the actual template parms. */
20266 tree au = cxx_make_type (TEMPLATE_TYPE_PARM);
20267 TYPE_NAME (au) = build_decl (BUILTINS_LOCATION,
20268 TYPE_DECL, get_identifier ("auto"), au);
20269 TYPE_STUB_DECL (au) = TYPE_NAME (au);
20270 TEMPLATE_TYPE_PARM_INDEX (au) = build_template_parm_index
20271 (0, processing_template_decl + 1, processing_template_decl + 1,
20272 0, TYPE_NAME (au), NULL_TREE);
20273 TYPE_CANONICAL (au) = canonical_type_parameter (au);
20274 DECL_ARTIFICIAL (TYPE_NAME (au)) = 1;
20275 SET_DECL_TEMPLATE_PARM_P (TYPE_NAME (au));
20280 /* Given type ARG, return std::initializer_list<ARG>. */
20285 tree std_init_list = namespace_binding
20286 (get_identifier ("initializer_list"), std_node);
20288 if (!std_init_list || !DECL_CLASS_TEMPLATE_P (std_init_list))
20290 error ("deducing from brace-enclosed initializer list requires "
20291 "#include <initializer_list>");
20292 return error_mark_node;
20294 argvec = make_tree_vec (1);
20295 TREE_VEC_ELT (argvec, 0) = arg;
20296 return lookup_template_class (std_init_list, argvec, NULL_TREE,
20297 NULL_TREE, 0, tf_warning_or_error);
20300 /* Replace auto in TYPE with std::initializer_list<auto>. */
20303 listify_autos (tree type, tree auto_node)
20305 tree init_auto = listify (auto_node);
20306 tree argvec = make_tree_vec (1);
20307 TREE_VEC_ELT (argvec, 0) = init_auto;
20308 if (processing_template_decl)
20309 argvec = add_to_template_args (current_template_args (), argvec);
20310 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
20313 /* walk_tree helper for do_auto_deduction. */
20316 contains_auto_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
20319 /* Is this a variable with the type we're looking for? */
20321 && TREE_TYPE (*tp) == type)
20327 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
20328 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
20331 do_auto_deduction (tree type, tree init, tree auto_node)
20333 tree parms, tparms, targs;
20338 if (processing_template_decl
20339 && (TREE_TYPE (init) == NULL_TREE
20340 || BRACE_ENCLOSED_INITIALIZER_P (init)))
20341 /* Not enough information to try this yet. */
20344 /* The name of the object being declared shall not appear in the
20345 initializer expression. */
20346 decl = cp_walk_tree_without_duplicates (&init, contains_auto_r, type);
20349 error ("variable %q#D with %<auto%> type used in its own "
20350 "initializer", decl);
20351 return error_mark_node;
20354 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
20355 with either a new invented type template parameter U or, if the
20356 initializer is a braced-init-list (8.5.4), with
20357 std::initializer_list<U>. */
20358 if (BRACE_ENCLOSED_INITIALIZER_P (init))
20359 type = listify_autos (type, auto_node);
20361 init = resolve_nondeduced_context (init);
20363 parms = build_tree_list (NULL_TREE, type);
20365 tparms = make_tree_vec (1);
20366 targs = make_tree_vec (1);
20367 TREE_VEC_ELT (tparms, 0)
20368 = build_tree_list (NULL_TREE, TYPE_NAME (auto_node));
20369 val = type_unification_real (tparms, targs, parms, args, 1, 0,
20370 DEDUCE_CALL, LOOKUP_NORMAL,
20371 /*explain_p=*/false);
20374 if (processing_template_decl)
20375 /* Try again at instantiation time. */
20377 if (type && type != error_mark_node)
20378 /* If type is error_mark_node a diagnostic must have been
20379 emitted by now. Also, having a mention to '<type error>'
20380 in the diagnostic is not really useful to the user. */
20381 error ("unable to deduce %qT from %qE", type, init);
20382 return error_mark_node;
20385 /* If the list of declarators contains more than one declarator, the type
20386 of each declared variable is determined as described above. If the
20387 type deduced for the template parameter U is not the same in each
20388 deduction, the program is ill-formed. */
20389 if (TREE_TYPE (auto_node)
20390 && !same_type_p (TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0)))
20392 error ("inconsistent deduction for %qT: %qT and then %qT",
20393 auto_node, TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0));
20394 return error_mark_node;
20396 TREE_TYPE (auto_node) = TREE_VEC_ELT (targs, 0);
20398 if (processing_template_decl)
20399 targs = add_to_template_args (current_template_args (), targs);
20400 return tsubst (type, targs, tf_warning_or_error, NULL_TREE);
20403 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
20407 splice_late_return_type (tree type, tree late_return_type)
20411 if (late_return_type == NULL_TREE)
20413 argvec = make_tree_vec (1);
20414 TREE_VEC_ELT (argvec, 0) = late_return_type;
20415 if (processing_template_parmlist)
20416 /* For a late-specified return type in a template type-parameter, we
20417 need to add a dummy argument level for its parmlist. */
20418 argvec = add_to_template_args
20419 (make_tree_vec (processing_template_parmlist), argvec);
20420 if (current_template_parms)
20421 argvec = add_to_template_args (current_template_args (), argvec);
20422 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
20425 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto'. */
20428 is_auto (const_tree type)
20430 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
20431 && TYPE_IDENTIFIER (type) == get_identifier ("auto"))
20437 /* Returns true iff TYPE contains a use of 'auto'. Since auto can only
20438 appear as a type-specifier for the declaration in question, we don't
20439 have to look through the whole type. */
20442 type_uses_auto (tree type)
20444 enum tree_code code;
20445 if (is_auto (type))
20448 code = TREE_CODE (type);
20450 if (code == POINTER_TYPE || code == REFERENCE_TYPE
20451 || code == OFFSET_TYPE || code == FUNCTION_TYPE
20452 || code == METHOD_TYPE || code == ARRAY_TYPE)
20453 return type_uses_auto (TREE_TYPE (type));
20455 if (TYPE_PTRMEMFUNC_P (type))
20456 return type_uses_auto (TREE_TYPE (TREE_TYPE
20457 (TYPE_PTRMEMFUNC_FN_TYPE (type))));
20462 /* For a given template T, return the vector of typedefs referenced
20463 in T for which access check is needed at T instantiation time.
20464 T is either a FUNCTION_DECL or a RECORD_TYPE.
20465 Those typedefs were added to T by the function
20466 append_type_to_template_for_access_check. */
20468 VEC(qualified_typedef_usage_t,gc)*
20469 get_types_needing_access_check (tree t)
20472 VEC(qualified_typedef_usage_t,gc) *result = NULL;
20474 if (!t || t == error_mark_node)
20477 if (!(ti = get_template_info (t)))
20480 if (CLASS_TYPE_P (t)
20481 || TREE_CODE (t) == FUNCTION_DECL)
20483 if (!TI_TEMPLATE (ti))
20486 result = TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti);
20492 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
20493 tied to T. That list of typedefs will be access checked at
20494 T instantiation time.
20495 T is either a FUNCTION_DECL or a RECORD_TYPE.
20496 TYPE_DECL is a TYPE_DECL node representing a typedef.
20497 SCOPE is the scope through which TYPE_DECL is accessed.
20498 LOCATION is the location of the usage point of TYPE_DECL.
20500 This function is a subroutine of
20501 append_type_to_template_for_access_check. */
20504 append_type_to_template_for_access_check_1 (tree t,
20507 location_t location)
20509 qualified_typedef_usage_t typedef_usage;
20512 if (!t || t == error_mark_node)
20515 gcc_assert ((TREE_CODE (t) == FUNCTION_DECL
20516 || CLASS_TYPE_P (t))
20518 && TREE_CODE (type_decl) == TYPE_DECL
20521 if (!(ti = get_template_info (t)))
20524 gcc_assert (TI_TEMPLATE (ti));
20526 typedef_usage.typedef_decl = type_decl;
20527 typedef_usage.context = scope;
20528 typedef_usage.locus = location;
20530 VEC_safe_push (qualified_typedef_usage_t, gc,
20531 TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti),
20535 /* Append TYPE_DECL to the template TEMPL.
20536 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
20537 At TEMPL instanciation time, TYPE_DECL will be checked to see
20538 if it can be accessed through SCOPE.
20539 LOCATION is the location of the usage point of TYPE_DECL.
20541 e.g. consider the following code snippet:
20548 template<class U> struct S
20550 C::myint mi; // <-- usage point of the typedef C::myint
20555 At S<char> instantiation time, we need to check the access of C::myint
20556 In other words, we need to check the access of the myint typedef through
20557 the C scope. For that purpose, this function will add the myint typedef
20558 and the scope C through which its being accessed to a list of typedefs
20559 tied to the template S. That list will be walked at template instantiation
20560 time and access check performed on each typedefs it contains.
20561 Note that this particular code snippet should yield an error because
20562 myint is private to C. */
20565 append_type_to_template_for_access_check (tree templ,
20568 location_t location)
20570 qualified_typedef_usage_t *iter;
20573 gcc_assert (type_decl && (TREE_CODE (type_decl) == TYPE_DECL));
20575 /* Make sure we don't append the type to the template twice. */
20576 FOR_EACH_VEC_ELT (qualified_typedef_usage_t,
20577 get_types_needing_access_check (templ),
20579 if (iter->typedef_decl == type_decl && scope == iter->context)
20582 append_type_to_template_for_access_check_1 (templ, type_decl,
20586 /* Set up the hash tables for template instantiations. */
20589 init_template_processing (void)
20591 decl_specializations = htab_create_ggc (37,
20592 hash_specialization,
20593 eq_specializations,
20595 type_specializations = htab_create_ggc (37,
20596 hash_specialization,
20597 eq_specializations,
20601 /* Print stats about the template hash tables for -fstats. */
20604 print_template_statistics (void)
20606 fprintf (stderr, "decl_specializations: size %ld, %ld elements, "
20607 "%f collisions\n", (long) htab_size (decl_specializations),
20608 (long) htab_elements (decl_specializations),
20609 htab_collisions (decl_specializations));
20610 fprintf (stderr, "type_specializations: size %ld, %ld elements, "
20611 "%f collisions\n", (long) htab_size (type_specializations),
20612 (long) htab_elements (type_specializations),
20613 htab_collisions (type_specializations));
20616 #include "gt-cp-pt.h"