1 /* Handle parameterized types (templates) for GNU C++.
2 Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
3 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010, 2011
4 Free Software Foundation, Inc.
5 Written by Ken Raeburn (raeburn@cygnus.com) while at Watchmaker Computing.
6 Rewritten by Jason Merrill (jason@cygnus.com).
8 This file is part of GCC.
10 GCC is free software; you can redistribute it and/or modify
11 it under the terms of the GNU General Public License as published by
12 the Free Software Foundation; either version 3, or (at your option)
15 GCC is distributed in the hope that it will be useful,
16 but WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 GNU General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with GCC; see the file COPYING3. If not see
22 <http://www.gnu.org/licenses/>. */
24 /* Known bugs or deficiencies include:
26 all methods must be provided in header files; can't use a source
27 file that contains only the method templates and "just win". */
31 #include "coretypes.h"
35 #include "pointer-set.h"
38 #include "c-family/c-common.h"
39 #include "c-family/c-objc.h"
40 #include "cp-objcp-common.h"
41 #include "tree-inline.h"
46 #include "tree-iterator.h"
49 /* The type of functions taking a tree, and some additional data, and
51 typedef int (*tree_fn_t) (tree, void*);
53 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
54 instantiations have been deferred, either because their definitions
55 were not yet available, or because we were putting off doing the work. */
56 struct GTY ((chain_next ("%h.next"))) pending_template {
57 struct pending_template *next;
58 struct tinst_level *tinst;
61 static GTY(()) struct pending_template *pending_templates;
62 static GTY(()) struct pending_template *last_pending_template;
64 int processing_template_parmlist;
65 static int template_header_count;
67 static GTY(()) tree saved_trees;
68 static VEC(int,heap) *inline_parm_levels;
70 static GTY(()) struct tinst_level *current_tinst_level;
72 static GTY(()) tree saved_access_scope;
74 /* Live only within one (recursive) call to tsubst_expr. We use
75 this to pass the statement expression node from the STMT_EXPR
76 to the EXPR_STMT that is its result. */
77 static tree cur_stmt_expr;
79 /* A map from local variable declarations in the body of the template
80 presently being instantiated to the corresponding instantiated
82 static htab_t local_specializations;
84 typedef struct GTY(()) spec_entry
91 static GTY ((param_is (spec_entry)))
92 htab_t decl_specializations;
94 static GTY ((param_is (spec_entry)))
95 htab_t type_specializations;
97 /* Contains canonical template parameter types. The vector is indexed by
98 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
99 TREE_LIST, whose TREE_VALUEs contain the canonical template
100 parameters of various types and levels. */
101 static GTY(()) VEC(tree,gc) *canonical_template_parms;
103 #define UNIFY_ALLOW_NONE 0
104 #define UNIFY_ALLOW_MORE_CV_QUAL 1
105 #define UNIFY_ALLOW_LESS_CV_QUAL 2
106 #define UNIFY_ALLOW_DERIVED 4
107 #define UNIFY_ALLOW_INTEGER 8
108 #define UNIFY_ALLOW_OUTER_LEVEL 16
109 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
110 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
112 static void push_access_scope (tree);
113 static void pop_access_scope (tree);
114 static bool resolve_overloaded_unification (tree, tree, tree, tree,
115 unification_kind_t, int);
116 static int try_one_overload (tree, tree, tree, tree, tree,
117 unification_kind_t, int, bool);
118 static int unify (tree, tree, tree, tree, int);
119 static void add_pending_template (tree);
120 static tree reopen_tinst_level (struct tinst_level *);
121 static tree tsubst_initializer_list (tree, tree);
122 static tree get_class_bindings (tree, tree, tree);
123 static tree coerce_template_parms (tree, tree, tree, tsubst_flags_t,
125 static void tsubst_enum (tree, tree, tree);
126 static tree add_to_template_args (tree, tree);
127 static tree add_outermost_template_args (tree, tree);
128 static bool check_instantiated_args (tree, tree, tsubst_flags_t);
129 static int maybe_adjust_types_for_deduction (unification_kind_t, tree*, tree*,
131 static int type_unification_real (tree, tree, tree, const tree *,
132 unsigned int, int, unification_kind_t, int);
133 static void note_template_header (int);
134 static tree convert_nontype_argument_function (tree, tree);
135 static tree convert_nontype_argument (tree, tree, tsubst_flags_t);
136 static tree convert_template_argument (tree, tree, tree,
137 tsubst_flags_t, int, tree);
138 static int for_each_template_parm (tree, tree_fn_t, void*,
139 struct pointer_set_t*, bool);
140 static tree expand_template_argument_pack (tree);
141 static tree build_template_parm_index (int, int, int, int, tree, tree);
142 static bool inline_needs_template_parms (tree);
143 static void push_inline_template_parms_recursive (tree, int);
144 static tree retrieve_local_specialization (tree);
145 static void register_local_specialization (tree, tree);
146 static hashval_t hash_specialization (const void *p);
147 static tree reduce_template_parm_level (tree, tree, int, tree, tsubst_flags_t);
148 static int mark_template_parm (tree, void *);
149 static int template_parm_this_level_p (tree, void *);
150 static tree tsubst_friend_function (tree, tree);
151 static tree tsubst_friend_class (tree, tree);
152 static int can_complete_type_without_circularity (tree);
153 static tree get_bindings (tree, tree, tree, bool);
154 static int template_decl_level (tree);
155 static int check_cv_quals_for_unify (int, tree, tree);
156 static void template_parm_level_and_index (tree, int*, int*);
157 static int unify_pack_expansion (tree, tree, tree, tree, int, bool, bool);
158 static tree tsubst_template_arg (tree, tree, tsubst_flags_t, tree);
159 static tree tsubst_template_args (tree, tree, tsubst_flags_t, tree);
160 static tree tsubst_template_parms (tree, tree, tsubst_flags_t);
161 static void regenerate_decl_from_template (tree, tree);
162 static tree most_specialized_class (tree, tree, tsubst_flags_t);
163 static tree tsubst_aggr_type (tree, tree, tsubst_flags_t, tree, int);
164 static tree tsubst_arg_types (tree, tree, tsubst_flags_t, tree);
165 static tree tsubst_function_type (tree, tree, tsubst_flags_t, tree);
166 static bool check_specialization_scope (void);
167 static tree process_partial_specialization (tree);
168 static void set_current_access_from_decl (tree);
169 static tree get_template_base (tree, tree, tree, tree);
170 static tree try_class_unification (tree, tree, tree, tree);
171 static int coerce_template_template_parms (tree, tree, tsubst_flags_t,
173 static bool template_template_parm_bindings_ok_p (tree, tree);
174 static int template_args_equal (tree, tree);
175 static void tsubst_default_arguments (tree);
176 static tree for_each_template_parm_r (tree *, int *, void *);
177 static tree copy_default_args_to_explicit_spec_1 (tree, tree);
178 static void copy_default_args_to_explicit_spec (tree);
179 static int invalid_nontype_parm_type_p (tree, tsubst_flags_t);
180 static int eq_local_specializations (const void *, const void *);
181 static bool dependent_template_arg_p (tree);
182 static bool any_template_arguments_need_structural_equality_p (tree);
183 static bool dependent_type_p_r (tree);
184 static tree tsubst_expr (tree, tree, tsubst_flags_t, tree, bool);
185 static tree tsubst_copy (tree, tree, tsubst_flags_t, tree);
186 static tree tsubst_pack_expansion (tree, tree, tsubst_flags_t, tree);
187 static tree tsubst_decl (tree, tree, tsubst_flags_t);
188 static void perform_typedefs_access_check (tree tmpl, tree targs);
189 static void append_type_to_template_for_access_check_1 (tree, tree, tree,
191 static tree listify (tree);
192 static tree listify_autos (tree, tree);
193 static tree template_parm_to_arg (tree t);
194 static tree current_template_args (void);
195 static tree fixup_template_type_parm_type (tree, int);
196 static tree fixup_template_parm_index (tree, tree, int);
197 static tree tsubst_template_parm (tree, tree, tsubst_flags_t);
199 /* Make the current scope suitable for access checking when we are
200 processing T. T can be FUNCTION_DECL for instantiated function
201 template, or VAR_DECL for static member variable (need by
202 instantiate_decl). */
205 push_access_scope (tree t)
207 gcc_assert (TREE_CODE (t) == FUNCTION_DECL
208 || TREE_CODE (t) == VAR_DECL);
210 if (DECL_FRIEND_CONTEXT (t))
211 push_nested_class (DECL_FRIEND_CONTEXT (t));
212 else if (DECL_CLASS_SCOPE_P (t))
213 push_nested_class (DECL_CONTEXT (t));
215 push_to_top_level ();
217 if (TREE_CODE (t) == FUNCTION_DECL)
219 saved_access_scope = tree_cons
220 (NULL_TREE, current_function_decl, saved_access_scope);
221 current_function_decl = t;
225 /* Restore the scope set up by push_access_scope. T is the node we
229 pop_access_scope (tree t)
231 if (TREE_CODE (t) == FUNCTION_DECL)
233 current_function_decl = TREE_VALUE (saved_access_scope);
234 saved_access_scope = TREE_CHAIN (saved_access_scope);
237 if (DECL_FRIEND_CONTEXT (t) || DECL_CLASS_SCOPE_P (t))
240 pop_from_top_level ();
243 /* Do any processing required when DECL (a member template
244 declaration) is finished. Returns the TEMPLATE_DECL corresponding
245 to DECL, unless it is a specialization, in which case the DECL
246 itself is returned. */
249 finish_member_template_decl (tree decl)
251 if (decl == error_mark_node)
252 return error_mark_node;
254 gcc_assert (DECL_P (decl));
256 if (TREE_CODE (decl) == TYPE_DECL)
260 type = TREE_TYPE (decl);
261 if (type == error_mark_node)
262 return error_mark_node;
263 if (MAYBE_CLASS_TYPE_P (type)
264 && CLASSTYPE_TEMPLATE_INFO (type)
265 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
267 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
268 check_member_template (tmpl);
273 else if (TREE_CODE (decl) == FIELD_DECL)
274 error ("data member %qD cannot be a member template", decl);
275 else if (DECL_TEMPLATE_INFO (decl))
277 if (!DECL_TEMPLATE_SPECIALIZATION (decl))
279 check_member_template (DECL_TI_TEMPLATE (decl));
280 return DECL_TI_TEMPLATE (decl);
286 error ("invalid member template declaration %qD", decl);
288 return error_mark_node;
291 /* Create a template info node. */
294 build_template_info (tree template_decl, tree template_args)
296 tree result = make_node (TEMPLATE_INFO);
297 TI_TEMPLATE (result) = template_decl;
298 TI_ARGS (result) = template_args;
302 /* Return the template info node corresponding to T, whatever T is. */
305 get_template_info (const_tree t)
307 tree tinfo = NULL_TREE;
309 if (!t || t == error_mark_node)
312 if (DECL_P (t) && DECL_LANG_SPECIFIC (t))
313 tinfo = DECL_TEMPLATE_INFO (t);
315 if (!tinfo && DECL_IMPLICIT_TYPEDEF_P (t))
318 if (TAGGED_TYPE_P (t))
319 tinfo = TYPE_TEMPLATE_INFO (t);
320 else if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
321 tinfo = TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (t);
326 /* Returns the template nesting level of the indicated class TYPE.
336 A<T>::B<U> has depth two, while A<T> has depth one.
337 Both A<T>::B<int> and A<int>::B<U> have depth one, if
338 they are instantiations, not specializations.
340 This function is guaranteed to return 0 if passed NULL_TREE so
341 that, for example, `template_class_depth (current_class_type)' is
345 template_class_depth (tree type)
350 type && TREE_CODE (type) != NAMESPACE_DECL;
351 type = (TREE_CODE (type) == FUNCTION_DECL)
352 ? CP_DECL_CONTEXT (type) : CP_TYPE_CONTEXT (type))
354 tree tinfo = get_template_info (type);
356 if (tinfo && PRIMARY_TEMPLATE_P (TI_TEMPLATE (tinfo))
357 && uses_template_parms (INNERMOST_TEMPLATE_ARGS (TI_ARGS (tinfo))))
364 /* Subroutine of maybe_begin_member_template_processing.
365 Returns true if processing DECL needs us to push template parms. */
368 inline_needs_template_parms (tree decl)
370 if (! DECL_TEMPLATE_INFO (decl))
373 return (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (most_general_template (decl)))
374 > (processing_template_decl + DECL_TEMPLATE_SPECIALIZATION (decl)));
377 /* Subroutine of maybe_begin_member_template_processing.
378 Push the template parms in PARMS, starting from LEVELS steps into the
379 chain, and ending at the beginning, since template parms are listed
383 push_inline_template_parms_recursive (tree parmlist, int levels)
385 tree parms = TREE_VALUE (parmlist);
389 push_inline_template_parms_recursive (TREE_CHAIN (parmlist), levels - 1);
391 ++processing_template_decl;
392 current_template_parms
393 = tree_cons (size_int (processing_template_decl),
394 parms, current_template_parms);
395 TEMPLATE_PARMS_FOR_INLINE (current_template_parms) = 1;
397 begin_scope (TREE_VEC_LENGTH (parms) ? sk_template_parms : sk_template_spec,
399 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
401 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
403 if (parm == error_mark_node)
406 gcc_assert (DECL_P (parm));
408 switch (TREE_CODE (parm))
417 /* Make a CONST_DECL as is done in process_template_parm.
418 It is ugly that we recreate this here; the original
419 version built in process_template_parm is no longer
421 tree decl = build_decl (DECL_SOURCE_LOCATION (parm),
422 CONST_DECL, DECL_NAME (parm),
424 DECL_ARTIFICIAL (decl) = 1;
425 TREE_CONSTANT (decl) = 1;
426 TREE_READONLY (decl) = 1;
427 DECL_INITIAL (decl) = DECL_INITIAL (parm);
428 SET_DECL_TEMPLATE_PARM_P (decl);
439 /* Restore the template parameter context for a member template or
440 a friend template defined in a class definition. */
443 maybe_begin_member_template_processing (tree decl)
448 if (inline_needs_template_parms (decl))
450 parms = DECL_TEMPLATE_PARMS (most_general_template (decl));
451 levels = TMPL_PARMS_DEPTH (parms) - processing_template_decl;
453 if (DECL_TEMPLATE_SPECIALIZATION (decl))
456 parms = TREE_CHAIN (parms);
459 push_inline_template_parms_recursive (parms, levels);
462 /* Remember how many levels of template parameters we pushed so that
463 we can pop them later. */
464 VEC_safe_push (int, heap, inline_parm_levels, levels);
467 /* Undo the effects of maybe_begin_member_template_processing. */
470 maybe_end_member_template_processing (void)
475 if (VEC_length (int, inline_parm_levels) == 0)
478 last = VEC_pop (int, inline_parm_levels);
479 for (i = 0; i < last; ++i)
481 --processing_template_decl;
482 current_template_parms = TREE_CHAIN (current_template_parms);
487 /* Return a new template argument vector which contains all of ARGS,
488 but has as its innermost set of arguments the EXTRA_ARGS. */
491 add_to_template_args (tree args, tree extra_args)
498 if (args == NULL_TREE || extra_args == error_mark_node)
501 extra_depth = TMPL_ARGS_DEPTH (extra_args);
502 new_args = make_tree_vec (TMPL_ARGS_DEPTH (args) + extra_depth);
504 for (i = 1; i <= TMPL_ARGS_DEPTH (args); ++i)
505 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (args, i));
507 for (j = 1; j <= extra_depth; ++j, ++i)
508 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (extra_args, j));
513 /* Like add_to_template_args, but only the outermost ARGS are added to
514 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
515 (EXTRA_ARGS) levels are added. This function is used to combine
516 the template arguments from a partial instantiation with the
517 template arguments used to attain the full instantiation from the
518 partial instantiation. */
521 add_outermost_template_args (tree args, tree extra_args)
525 /* If there are more levels of EXTRA_ARGS than there are ARGS,
526 something very fishy is going on. */
527 gcc_assert (TMPL_ARGS_DEPTH (args) >= TMPL_ARGS_DEPTH (extra_args));
529 /* If *all* the new arguments will be the EXTRA_ARGS, just return
531 if (TMPL_ARGS_DEPTH (args) == TMPL_ARGS_DEPTH (extra_args))
534 /* For the moment, we make ARGS look like it contains fewer levels. */
535 TREE_VEC_LENGTH (args) -= TMPL_ARGS_DEPTH (extra_args);
537 new_args = add_to_template_args (args, extra_args);
539 /* Now, we restore ARGS to its full dimensions. */
540 TREE_VEC_LENGTH (args) += TMPL_ARGS_DEPTH (extra_args);
545 /* Return the N levels of innermost template arguments from the ARGS. */
548 get_innermost_template_args (tree args, int n)
556 /* If N is 1, just return the innermost set of template arguments. */
558 return TMPL_ARGS_LEVEL (args, TMPL_ARGS_DEPTH (args));
560 /* If we're not removing anything, just return the arguments we were
562 extra_levels = TMPL_ARGS_DEPTH (args) - n;
563 gcc_assert (extra_levels >= 0);
564 if (extra_levels == 0)
567 /* Make a new set of arguments, not containing the outer arguments. */
568 new_args = make_tree_vec (n);
569 for (i = 1; i <= n; ++i)
570 SET_TMPL_ARGS_LEVEL (new_args, i,
571 TMPL_ARGS_LEVEL (args, i + extra_levels));
576 /* The inverse of get_innermost_template_args: Return all but the innermost
577 EXTRA_LEVELS levels of template arguments from the ARGS. */
580 strip_innermost_template_args (tree args, int extra_levels)
583 int n = TMPL_ARGS_DEPTH (args) - extra_levels;
588 /* If N is 1, just return the outermost set of template arguments. */
590 return TMPL_ARGS_LEVEL (args, 1);
592 /* If we're not removing anything, just return the arguments we were
594 gcc_assert (extra_levels >= 0);
595 if (extra_levels == 0)
598 /* Make a new set of arguments, not containing the inner arguments. */
599 new_args = make_tree_vec (n);
600 for (i = 1; i <= n; ++i)
601 SET_TMPL_ARGS_LEVEL (new_args, i,
602 TMPL_ARGS_LEVEL (args, i));
607 /* We've got a template header coming up; push to a new level for storing
611 begin_template_parm_list (void)
613 /* We use a non-tag-transparent scope here, which causes pushtag to
614 put tags in this scope, rather than in the enclosing class or
615 namespace scope. This is the right thing, since we want
616 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
617 global template class, push_template_decl handles putting the
618 TEMPLATE_DECL into top-level scope. For a nested template class,
621 template <class T> struct S1 {
622 template <class T> struct S2 {};
625 pushtag contains special code to call pushdecl_with_scope on the
626 TEMPLATE_DECL for S2. */
627 begin_scope (sk_template_parms, NULL);
628 ++processing_template_decl;
629 ++processing_template_parmlist;
630 note_template_header (0);
633 /* This routine is called when a specialization is declared. If it is
634 invalid to declare a specialization here, an error is reported and
635 false is returned, otherwise this routine will return true. */
638 check_specialization_scope (void)
640 tree scope = current_scope ();
644 An explicit specialization shall be declared in the namespace of
645 which the template is a member, or, for member templates, in the
646 namespace of which the enclosing class or enclosing class
647 template is a member. An explicit specialization of a member
648 function, member class or static data member of a class template
649 shall be declared in the namespace of which the class template
651 if (scope && TREE_CODE (scope) != NAMESPACE_DECL)
653 error ("explicit specialization in non-namespace scope %qD", scope);
659 In an explicit specialization declaration for a member of a class
660 template or a member template that appears in namespace scope,
661 the member template and some of its enclosing class templates may
662 remain unspecialized, except that the declaration shall not
663 explicitly specialize a class member template if its enclosing
664 class templates are not explicitly specialized as well. */
665 if (current_template_parms)
667 error ("enclosing class templates are not explicitly specialized");
674 /* We've just seen template <>. */
677 begin_specialization (void)
679 begin_scope (sk_template_spec, NULL);
680 note_template_header (1);
681 return check_specialization_scope ();
684 /* Called at then end of processing a declaration preceded by
688 end_specialization (void)
691 reset_specialization ();
694 /* Any template <>'s that we have seen thus far are not referring to a
695 function specialization. */
698 reset_specialization (void)
700 processing_specialization = 0;
701 template_header_count = 0;
704 /* We've just seen a template header. If SPECIALIZATION is nonzero,
705 it was of the form template <>. */
708 note_template_header (int specialization)
710 processing_specialization = specialization;
711 template_header_count++;
714 /* We're beginning an explicit instantiation. */
717 begin_explicit_instantiation (void)
719 gcc_assert (!processing_explicit_instantiation);
720 processing_explicit_instantiation = true;
725 end_explicit_instantiation (void)
727 gcc_assert (processing_explicit_instantiation);
728 processing_explicit_instantiation = false;
731 /* An explicit specialization or partial specialization TMPL is being
732 declared. Check that the namespace in which the specialization is
733 occurring is permissible. Returns false iff it is invalid to
734 specialize TMPL in the current namespace. */
737 check_specialization_namespace (tree tmpl)
739 tree tpl_ns = decl_namespace_context (tmpl);
743 An explicit specialization shall be declared in the namespace of
744 which the template is a member, or, for member templates, in the
745 namespace of which the enclosing class or enclosing class
746 template is a member. An explicit specialization of a member
747 function, member class or static data member of a class template
748 shall be declared in the namespace of which the class template is
750 if (current_scope() != DECL_CONTEXT (tmpl)
751 && !at_namespace_scope_p ())
753 error ("specialization of %qD must appear at namespace scope", tmpl);
756 if (is_associated_namespace (current_namespace, tpl_ns))
757 /* Same or super-using namespace. */
761 permerror (input_location, "specialization of %qD in different namespace", tmpl);
762 permerror (input_location, " from definition of %q+#D", tmpl);
767 /* SPEC is an explicit instantiation. Check that it is valid to
768 perform this explicit instantiation in the current namespace. */
771 check_explicit_instantiation_namespace (tree spec)
775 /* DR 275: An explicit instantiation shall appear in an enclosing
776 namespace of its template. */
777 ns = decl_namespace_context (spec);
778 if (!is_ancestor (current_namespace, ns))
779 permerror (input_location, "explicit instantiation of %qD in namespace %qD "
780 "(which does not enclose namespace %qD)",
781 spec, current_namespace, ns);
784 /* The TYPE is being declared. If it is a template type, that means it
785 is a partial specialization. Do appropriate error-checking. */
788 maybe_process_partial_specialization (tree type)
792 if (type == error_mark_node)
793 return error_mark_node;
795 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
797 error ("name of class shadows template template parameter %qD",
799 return error_mark_node;
802 context = TYPE_CONTEXT (type);
804 if (CLASS_TYPE_P (type) && CLASSTYPE_USE_TEMPLATE (type))
806 /* This is for ordinary explicit specialization and partial
807 specialization of a template class such as:
809 template <> class C<int>;
813 template <class T> class C<T*>;
815 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
817 if (CLASSTYPE_IMPLICIT_INSTANTIATION (type)
818 && !COMPLETE_TYPE_P (type))
820 check_specialization_namespace (CLASSTYPE_TI_TEMPLATE (type));
821 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
822 if (processing_template_decl)
824 if (push_template_decl (TYPE_MAIN_DECL (type))
826 return error_mark_node;
829 else if (CLASSTYPE_TEMPLATE_INSTANTIATION (type))
830 error ("specialization of %qT after instantiation", type);
832 else if (CLASS_TYPE_P (type)
833 && !CLASSTYPE_USE_TEMPLATE (type)
834 && CLASSTYPE_TEMPLATE_INFO (type)
835 && context && CLASS_TYPE_P (context)
836 && CLASSTYPE_TEMPLATE_INFO (context))
838 /* This is for an explicit specialization of member class
839 template according to [temp.expl.spec/18]:
841 template <> template <class U> class C<int>::D;
843 The context `C<int>' must be an implicit instantiation.
844 Otherwise this is just a member class template declared
847 template <> class C<int> { template <class U> class D; };
848 template <> template <class U> class C<int>::D;
850 In the first case, `C<int>::D' is a specialization of `C<T>::D'
851 while in the second case, `C<int>::D' is a primary template
852 and `C<T>::D' may not exist. */
854 if (CLASSTYPE_IMPLICIT_INSTANTIATION (context)
855 && !COMPLETE_TYPE_P (type))
858 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
860 if (current_namespace
861 != decl_namespace_context (tmpl))
863 permerror (input_location, "specializing %q#T in different namespace", type);
864 permerror (input_location, " from definition of %q+#D", tmpl);
867 /* Check for invalid specialization after instantiation:
869 template <> template <> class C<int>::D<int>;
870 template <> template <class U> class C<int>::D; */
872 for (t = DECL_TEMPLATE_INSTANTIATIONS (tmpl);
873 t; t = TREE_CHAIN (t))
875 tree inst = TREE_VALUE (t);
876 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (inst))
878 /* We already have a full specialization of this partial
879 instantiation. Reassign it to the new member
880 specialization template. */
884 elt.tmpl = most_general_template (tmpl);
885 elt.args = CLASSTYPE_TI_ARGS (inst);
888 htab_remove_elt (type_specializations, &elt);
891 elt.args = INNERMOST_TEMPLATE_ARGS (elt.args);
893 slot = (spec_entry **)
894 htab_find_slot (type_specializations, &elt, INSERT);
895 *slot = ggc_alloc_spec_entry ();
898 else if (COMPLETE_OR_OPEN_TYPE_P (inst))
899 /* But if we've had an implicit instantiation, that's a
900 problem ([temp.expl.spec]/6). */
901 error ("specialization %qT after instantiation %qT",
905 /* Mark TYPE as a specialization. And as a result, we only
906 have one level of template argument for the innermost
908 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
909 CLASSTYPE_TI_ARGS (type)
910 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type));
913 else if (processing_specialization)
915 /* Someday C++0x may allow for enum template specialization. */
916 if (cxx_dialect > cxx98 && TREE_CODE (type) == ENUMERAL_TYPE
917 && CLASS_TYPE_P (context) && CLASSTYPE_USE_TEMPLATE (context))
918 pedwarn (input_location, OPT_pedantic, "template specialization "
919 "of %qD not allowed by ISO C++", type);
922 error ("explicit specialization of non-template %qT", type);
923 return error_mark_node;
930 /* Returns nonzero if we can optimize the retrieval of specializations
931 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
932 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
935 optimize_specialization_lookup_p (tree tmpl)
937 return (DECL_FUNCTION_TEMPLATE_P (tmpl)
938 && DECL_CLASS_SCOPE_P (tmpl)
939 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
941 && CLASS_TYPE_P (DECL_CONTEXT (tmpl))
942 /* The optimized lookup depends on the fact that the
943 template arguments for the member function template apply
944 purely to the containing class, which is not true if the
945 containing class is an explicit or partial
947 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (tmpl))
948 && !DECL_MEMBER_TEMPLATE_P (tmpl)
949 && !DECL_CONV_FN_P (tmpl)
950 /* It is possible to have a template that is not a member
951 template and is not a member of a template class:
953 template <typename T>
954 struct S { friend A::f(); };
956 Here, the friend function is a template, but the context does
957 not have template information. The optimized lookup relies
958 on having ARGS be the template arguments for both the class
959 and the function template. */
960 && !DECL_FRIEND_P (DECL_TEMPLATE_RESULT (tmpl)));
963 /* Retrieve the specialization (in the sense of [temp.spec] - a
964 specialization is either an instantiation or an explicit
965 specialization) of TMPL for the given template ARGS. If there is
966 no such specialization, return NULL_TREE. The ARGS are a vector of
967 arguments, or a vector of vectors of arguments, in the case of
968 templates with more than one level of parameters.
970 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
971 then we search for a partial specialization matching ARGS. This
972 parameter is ignored if TMPL is not a class template. */
975 retrieve_specialization (tree tmpl, tree args, hashval_t hash)
977 if (args == error_mark_node)
980 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
982 /* There should be as many levels of arguments as there are
983 levels of parameters. */
984 gcc_assert (TMPL_ARGS_DEPTH (args)
985 == TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl)));
987 if (optimize_specialization_lookup_p (tmpl))
990 tree class_specialization;
991 VEC(tree,gc) *methods;
995 /* The template arguments actually apply to the containing
996 class. Find the class specialization with those
998 class_template = CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (tmpl));
1000 = retrieve_specialization (class_template, args, 0);
1001 if (!class_specialization)
1003 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
1004 for the specialization. */
1005 idx = class_method_index_for_fn (class_specialization, tmpl);
1008 /* Iterate through the methods with the indicated name, looking
1009 for the one that has an instance of TMPL. */
1010 methods = CLASSTYPE_METHOD_VEC (class_specialization);
1011 for (fns = VEC_index (tree, methods, idx); fns; fns = OVL_NEXT (fns))
1013 tree fn = OVL_CURRENT (fns);
1014 if (DECL_TEMPLATE_INFO (fn) && DECL_TI_TEMPLATE (fn) == tmpl
1015 /* using-declarations can add base methods to the method vec,
1016 and we don't want those here. */
1017 && DECL_CONTEXT (fn) == class_specialization)
1026 htab_t specializations;
1030 elt.spec = NULL_TREE;
1032 if (DECL_CLASS_TEMPLATE_P (tmpl))
1033 specializations = type_specializations;
1035 specializations = decl_specializations;
1038 hash = hash_specialization (&elt);
1039 found = (spec_entry *) htab_find_with_hash (specializations, &elt, hash);
1047 /* Like retrieve_specialization, but for local declarations. */
1050 retrieve_local_specialization (tree tmpl)
1054 if (local_specializations == NULL)
1057 spec = (tree) htab_find_with_hash (local_specializations, tmpl,
1058 htab_hash_pointer (tmpl));
1059 return spec ? TREE_PURPOSE (spec) : NULL_TREE;
1062 /* Returns nonzero iff DECL is a specialization of TMPL. */
1065 is_specialization_of (tree decl, tree tmpl)
1069 if (TREE_CODE (decl) == FUNCTION_DECL)
1073 t = DECL_TEMPLATE_INFO (t) ? DECL_TI_TEMPLATE (t) : NULL_TREE)
1079 gcc_assert (TREE_CODE (decl) == TYPE_DECL);
1081 for (t = TREE_TYPE (decl);
1083 t = CLASSTYPE_USE_TEMPLATE (t)
1084 ? TREE_TYPE (CLASSTYPE_TI_TEMPLATE (t)) : NULL_TREE)
1085 if (same_type_ignoring_top_level_qualifiers_p (t, TREE_TYPE (tmpl)))
1092 /* Returns nonzero iff DECL is a specialization of friend declaration
1093 FRIEND_DECL according to [temp.friend]. */
1096 is_specialization_of_friend (tree decl, tree friend_decl)
1098 bool need_template = true;
1101 gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
1102 || TREE_CODE (decl) == TYPE_DECL);
1104 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1105 of a template class, we want to check if DECL is a specialization
1107 if (TREE_CODE (friend_decl) == FUNCTION_DECL
1108 && DECL_TEMPLATE_INFO (friend_decl)
1109 && !DECL_USE_TEMPLATE (friend_decl))
1111 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1112 friend_decl = DECL_TI_TEMPLATE (friend_decl);
1113 need_template = false;
1115 else if (TREE_CODE (friend_decl) == TEMPLATE_DECL
1116 && !PRIMARY_TEMPLATE_P (friend_decl))
1117 need_template = false;
1119 /* There is nothing to do if this is not a template friend. */
1120 if (TREE_CODE (friend_decl) != TEMPLATE_DECL)
1123 if (is_specialization_of (decl, friend_decl))
1127 A member of a class template may be declared to be a friend of a
1128 non-template class. In this case, the corresponding member of
1129 every specialization of the class template is a friend of the
1130 class granting friendship.
1132 For example, given a template friend declaration
1134 template <class T> friend void A<T>::f();
1136 the member function below is considered a friend
1138 template <> struct A<int> {
1142 For this type of template friend, TEMPLATE_DEPTH below will be
1143 nonzero. To determine if DECL is a friend of FRIEND, we first
1144 check if the enclosing class is a specialization of another. */
1146 template_depth = template_class_depth (CP_DECL_CONTEXT (friend_decl));
1148 && DECL_CLASS_SCOPE_P (decl)
1149 && is_specialization_of (TYPE_NAME (DECL_CONTEXT (decl)),
1150 CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (friend_decl))))
1152 /* Next, we check the members themselves. In order to handle
1153 a few tricky cases, such as when FRIEND_DECL's are
1155 template <class T> friend void A<T>::g(T t);
1156 template <class T> template <T t> friend void A<T>::h();
1160 void A<int>::g(int);
1161 template <int> void A<int>::h();
1163 we need to figure out ARGS, the template arguments from
1164 the context of DECL. This is required for template substitution
1165 of `T' in the function parameter of `g' and template parameter
1166 of `h' in the above examples. Here ARGS corresponds to `int'. */
1168 tree context = DECL_CONTEXT (decl);
1169 tree args = NULL_TREE;
1170 int current_depth = 0;
1172 while (current_depth < template_depth)
1174 if (CLASSTYPE_TEMPLATE_INFO (context))
1176 if (current_depth == 0)
1177 args = TYPE_TI_ARGS (context);
1179 args = add_to_template_args (TYPE_TI_ARGS (context), args);
1182 context = TYPE_CONTEXT (context);
1185 if (TREE_CODE (decl) == FUNCTION_DECL)
1190 tree friend_args_type;
1191 tree decl_args_type;
1193 /* Make sure that both DECL and FRIEND_DECL are templates or
1195 is_template = DECL_TEMPLATE_INFO (decl)
1196 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (decl));
1197 if (need_template ^ is_template)
1199 else if (is_template)
1201 /* If both are templates, check template parameter list. */
1203 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1205 if (!comp_template_parms
1206 (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (decl)),
1210 decl_type = TREE_TYPE (DECL_TI_TEMPLATE (decl));
1213 decl_type = TREE_TYPE (decl);
1215 friend_type = tsubst_function_type (TREE_TYPE (friend_decl), args,
1216 tf_none, NULL_TREE);
1217 if (friend_type == error_mark_node)
1220 /* Check if return types match. */
1221 if (!same_type_p (TREE_TYPE (decl_type), TREE_TYPE (friend_type)))
1224 /* Check if function parameter types match, ignoring the
1225 `this' parameter. */
1226 friend_args_type = TYPE_ARG_TYPES (friend_type);
1227 decl_args_type = TYPE_ARG_TYPES (decl_type);
1228 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (friend_decl))
1229 friend_args_type = TREE_CHAIN (friend_args_type);
1230 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1231 decl_args_type = TREE_CHAIN (decl_args_type);
1233 return compparms (decl_args_type, friend_args_type);
1237 /* DECL is a TYPE_DECL */
1239 tree decl_type = TREE_TYPE (decl);
1241 /* Make sure that both DECL and FRIEND_DECL are templates or
1244 = CLASSTYPE_TEMPLATE_INFO (decl_type)
1245 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (decl_type));
1247 if (need_template ^ is_template)
1249 else if (is_template)
1252 /* If both are templates, check the name of the two
1253 TEMPLATE_DECL's first because is_friend didn't. */
1254 if (DECL_NAME (CLASSTYPE_TI_TEMPLATE (decl_type))
1255 != DECL_NAME (friend_decl))
1258 /* Now check template parameter list. */
1260 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1262 return comp_template_parms
1263 (DECL_TEMPLATE_PARMS (CLASSTYPE_TI_TEMPLATE (decl_type)),
1267 return (DECL_NAME (decl)
1268 == DECL_NAME (friend_decl));
1274 /* Register the specialization SPEC as a specialization of TMPL with
1275 the indicated ARGS. IS_FRIEND indicates whether the specialization
1276 is actually just a friend declaration. Returns SPEC, or an
1277 equivalent prior declaration, if available. */
1280 register_specialization (tree spec, tree tmpl, tree args, bool is_friend,
1284 spec_entry **slot = NULL;
1287 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL && DECL_P (spec));
1289 if (TREE_CODE (spec) == FUNCTION_DECL
1290 && uses_template_parms (DECL_TI_ARGS (spec)))
1291 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1292 register it; we want the corresponding TEMPLATE_DECL instead.
1293 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1294 the more obvious `uses_template_parms (spec)' to avoid problems
1295 with default function arguments. In particular, given
1296 something like this:
1298 template <class T> void f(T t1, T t = T())
1300 the default argument expression is not substituted for in an
1301 instantiation unless and until it is actually needed. */
1304 if (optimize_specialization_lookup_p (tmpl))
1305 /* We don't put these specializations in the hash table, but we might
1306 want to give an error about a mismatch. */
1307 fn = retrieve_specialization (tmpl, args, 0);
1315 hash = hash_specialization (&elt);
1317 slot = (spec_entry **)
1318 htab_find_slot_with_hash (decl_specializations, &elt, hash, INSERT);
1325 /* We can sometimes try to re-register a specialization that we've
1326 already got. In particular, regenerate_decl_from_template calls
1327 duplicate_decls which will update the specialization list. But,
1328 we'll still get called again here anyhow. It's more convenient
1329 to simply allow this than to try to prevent it. */
1332 else if (fn && DECL_TEMPLATE_SPECIALIZATION (spec))
1334 if (DECL_TEMPLATE_INSTANTIATION (fn))
1336 if (DECL_ODR_USED (fn)
1337 || DECL_EXPLICIT_INSTANTIATION (fn))
1339 error ("specialization of %qD after instantiation",
1341 return error_mark_node;
1346 /* This situation should occur only if the first
1347 specialization is an implicit instantiation, the
1348 second is an explicit specialization, and the
1349 implicit instantiation has not yet been used. That
1350 situation can occur if we have implicitly
1351 instantiated a member function and then specialized
1354 We can also wind up here if a friend declaration that
1355 looked like an instantiation turns out to be a
1358 template <class T> void foo(T);
1359 class S { friend void foo<>(int) };
1360 template <> void foo(int);
1362 We transform the existing DECL in place so that any
1363 pointers to it become pointers to the updated
1366 If there was a definition for the template, but not
1367 for the specialization, we want this to look as if
1368 there were no definition, and vice versa. */
1369 DECL_INITIAL (fn) = NULL_TREE;
1370 duplicate_decls (spec, fn, is_friend);
1371 /* The call to duplicate_decls will have applied
1374 An explicit specialization of a function template
1375 is inline only if it is explicitly declared to be,
1376 and independently of whether its function template
1379 to the primary function; now copy the inline bits to
1380 the various clones. */
1381 FOR_EACH_CLONE (clone, fn)
1383 DECL_DECLARED_INLINE_P (clone)
1384 = DECL_DECLARED_INLINE_P (fn);
1385 DECL_SOURCE_LOCATION (clone)
1386 = DECL_SOURCE_LOCATION (fn);
1388 check_specialization_namespace (fn);
1393 else if (DECL_TEMPLATE_SPECIALIZATION (fn))
1395 if (!duplicate_decls (spec, fn, is_friend) && DECL_INITIAL (spec))
1396 /* Dup decl failed, but this is a new definition. Set the
1397 line number so any errors match this new
1399 DECL_SOURCE_LOCATION (fn) = DECL_SOURCE_LOCATION (spec);
1405 return duplicate_decls (spec, fn, is_friend);
1407 /* A specialization must be declared in the same namespace as the
1408 template it is specializing. */
1409 if (DECL_TEMPLATE_SPECIALIZATION (spec)
1410 && !check_specialization_namespace (tmpl))
1411 DECL_CONTEXT (spec) = DECL_CONTEXT (tmpl);
1413 if (!optimize_specialization_lookup_p (tmpl))
1415 gcc_assert (tmpl && args && spec);
1416 *slot = ggc_alloc_spec_entry ();
1418 if (TREE_CODE (spec) == FUNCTION_DECL && DECL_NAMESPACE_SCOPE_P (spec)
1419 && PRIMARY_TEMPLATE_P (tmpl)
1420 && DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (tmpl)) == NULL_TREE)
1421 /* TMPL is a forward declaration of a template function; keep a list
1422 of all specializations in case we need to reassign them to a friend
1423 template later in tsubst_friend_function. */
1424 DECL_TEMPLATE_INSTANTIATIONS (tmpl)
1425 = tree_cons (args, spec, DECL_TEMPLATE_INSTANTIATIONS (tmpl));
1431 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1432 TMPL and ARGS members, ignores SPEC. */
1435 eq_specializations (const void *p1, const void *p2)
1437 const spec_entry *e1 = (const spec_entry *)p1;
1438 const spec_entry *e2 = (const spec_entry *)p2;
1440 return (e1->tmpl == e2->tmpl
1441 && comp_template_args (e1->args, e2->args));
1444 /* Returns a hash for a template TMPL and template arguments ARGS. */
1447 hash_tmpl_and_args (tree tmpl, tree args)
1449 hashval_t val = DECL_UID (tmpl);
1450 return iterative_hash_template_arg (args, val);
1453 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1457 hash_specialization (const void *p)
1459 const spec_entry *e = (const spec_entry *)p;
1460 return hash_tmpl_and_args (e->tmpl, e->args);
1463 /* Recursively calculate a hash value for a template argument ARG, for use
1464 in the hash tables of template specializations. */
1467 iterative_hash_template_arg (tree arg, hashval_t val)
1469 unsigned HOST_WIDE_INT i;
1470 enum tree_code code;
1473 if (arg == NULL_TREE)
1474 return iterative_hash_object (arg, val);
1479 if (TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
1480 /* We can get one of these when re-hashing a previous entry in the middle
1481 of substituting into a pack expansion. Just look through it. */
1482 arg = ARGUMENT_PACK_SELECT_FROM_PACK (arg);
1484 code = TREE_CODE (arg);
1485 tclass = TREE_CODE_CLASS (code);
1487 val = iterative_hash_object (code, val);
1494 case IDENTIFIER_NODE:
1495 return iterative_hash_object (IDENTIFIER_HASH_VALUE (arg), val);
1499 int i, len = TREE_VEC_LENGTH (arg);
1500 for (i = 0; i < len; ++i)
1501 val = iterative_hash_template_arg (TREE_VEC_ELT (arg, i), val);
1505 case TYPE_PACK_EXPANSION:
1506 case EXPR_PACK_EXPANSION:
1507 return iterative_hash_template_arg (PACK_EXPANSION_PATTERN (arg), val);
1509 case TYPE_ARGUMENT_PACK:
1510 case NONTYPE_ARGUMENT_PACK:
1511 return iterative_hash_template_arg (ARGUMENT_PACK_ARGS (arg), val);
1514 for (; arg; arg = TREE_CHAIN (arg))
1515 val = iterative_hash_template_arg (TREE_VALUE (arg), val);
1519 for (; arg; arg = OVL_NEXT (arg))
1520 val = iterative_hash_template_arg (OVL_CURRENT (arg), val);
1526 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg), i, field, value)
1528 val = iterative_hash_template_arg (field, val);
1529 val = iterative_hash_template_arg (value, val);
1535 if (!DECL_ARTIFICIAL (arg))
1537 val = iterative_hash_object (DECL_PARM_INDEX (arg), val);
1538 val = iterative_hash_object (DECL_PARM_LEVEL (arg), val);
1540 return iterative_hash_template_arg (TREE_TYPE (arg), val);
1543 return iterative_hash_template_arg (TARGET_EXPR_INITIAL (arg), val);
1546 val = iterative_hash_template_arg (PTRMEM_CST_CLASS (arg), val);
1547 return iterative_hash_template_arg (PTRMEM_CST_MEMBER (arg), val);
1549 case TEMPLATE_PARM_INDEX:
1550 val = iterative_hash_template_arg
1551 (TREE_TYPE (TEMPLATE_PARM_DECL (arg)), val);
1552 val = iterative_hash_object (TEMPLATE_PARM_LEVEL (arg), val);
1553 return iterative_hash_object (TEMPLATE_PARM_IDX (arg), val);
1556 val = iterative_hash_object (TRAIT_EXPR_KIND (arg), val);
1557 val = iterative_hash_template_arg (TRAIT_EXPR_TYPE1 (arg), val);
1558 return iterative_hash_template_arg (TRAIT_EXPR_TYPE2 (arg), val);
1561 val = iterative_hash_template_arg (BINFO_TYPE (BASELINK_BINFO (arg)),
1563 return iterative_hash_template_arg (DECL_NAME (get_first_fn (arg)),
1567 val = iterative_hash_template_arg (TREE_OPERAND (arg, 0), val);
1568 code = TREE_CODE (TREE_OPERAND (arg, 1));
1569 val = iterative_hash_object (code, val);
1570 return iterative_hash_template_arg (TREE_OPERAND (arg, 2), val);
1573 /* A lambda can't appear in a template arg, but don't crash on
1575 gcc_assert (seen_error ());
1579 case STATIC_CAST_EXPR:
1580 case REINTERPRET_CAST_EXPR:
1581 case CONST_CAST_EXPR:
1582 case DYNAMIC_CAST_EXPR:
1584 val = iterative_hash_template_arg (TREE_TYPE (arg), val);
1585 /* Now hash operands as usual. */
1595 if (TYPE_CANONICAL (arg))
1596 return iterative_hash_object (TYPE_HASH (TYPE_CANONICAL (arg)),
1598 else if (TREE_CODE (arg) == DECLTYPE_TYPE)
1599 return iterative_hash_template_arg (DECLTYPE_TYPE_EXPR (arg), val);
1600 /* Otherwise just compare the types during lookup. */
1603 case tcc_declaration:
1605 return iterative_hash_expr (arg, val);
1608 gcc_assert (IS_EXPR_CODE_CLASS (tclass));
1610 unsigned n = TREE_OPERAND_LENGTH (arg);
1611 for (i = 0; i < n; ++i)
1612 val = iterative_hash_template_arg (TREE_OPERAND (arg, i), val);
1620 /* Unregister the specialization SPEC as a specialization of TMPL.
1621 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1622 if the SPEC was listed as a specialization of TMPL.
1624 Note that SPEC has been ggc_freed, so we can't look inside it. */
1627 reregister_specialization (tree spec, tree tinfo, tree new_spec)
1632 elt.tmpl = most_general_template (TI_TEMPLATE (tinfo));
1633 elt.args = TI_ARGS (tinfo);
1634 elt.spec = NULL_TREE;
1636 slot = (spec_entry **) htab_find_slot (decl_specializations, &elt, INSERT);
1639 gcc_assert ((*slot)->spec == spec || (*slot)->spec == new_spec);
1640 gcc_assert (new_spec != NULL_TREE);
1641 (*slot)->spec = new_spec;
1648 /* Compare an entry in the local specializations hash table P1 (which
1649 is really a pointer to a TREE_LIST) with P2 (which is really a
1653 eq_local_specializations (const void *p1, const void *p2)
1655 return TREE_VALUE ((const_tree) p1) == (const_tree) p2;
1658 /* Hash P1, an entry in the local specializations table. */
1661 hash_local_specialization (const void* p1)
1663 return htab_hash_pointer (TREE_VALUE ((const_tree) p1));
1666 /* Like register_specialization, but for local declarations. We are
1667 registering SPEC, an instantiation of TMPL. */
1670 register_local_specialization (tree spec, tree tmpl)
1674 slot = htab_find_slot_with_hash (local_specializations, tmpl,
1675 htab_hash_pointer (tmpl), INSERT);
1676 *slot = build_tree_list (spec, tmpl);
1679 /* TYPE is a class type. Returns true if TYPE is an explicitly
1680 specialized class. */
1683 explicit_class_specialization_p (tree type)
1685 if (!CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
1687 return !uses_template_parms (CLASSTYPE_TI_ARGS (type));
1690 /* Print the list of functions at FNS, going through all the overloads
1691 for each element of the list. Alternatively, FNS can not be a
1692 TREE_LIST, in which case it will be printed together with all the
1695 MORE and *STR should respectively be FALSE and NULL when the function
1696 is called from the outside. They are used internally on recursive
1697 calls. print_candidates manages the two parameters and leaves NULL
1698 in *STR when it ends. */
1701 print_candidates_1 (tree fns, bool more, const char **str)
1704 char *spaces = NULL;
1706 for (fn = fns; fn; fn = OVL_NEXT (fn))
1707 if (TREE_CODE (fn) == TREE_LIST)
1709 gcc_assert (!OVL_NEXT (fn) && !is_overloaded_fn (fn));
1710 for (fn2 = fn; fn2 != NULL_TREE; fn2 = TREE_CHAIN (fn2))
1711 print_candidates_1 (TREE_VALUE (fn2),
1712 TREE_CHAIN (fn2) || more, str);
1718 /* Pick the prefix string. */
1719 if (!more && !OVL_NEXT (fns))
1721 error ("candidate is: %+#D", OVL_CURRENT (fn));
1725 *str = _("candidates are:");
1726 spaces = get_spaces (*str);
1728 error ("%s %+#D", *str, OVL_CURRENT (fn));
1729 *str = spaces ? spaces : *str;
1739 /* Print the list of candidate FNS in an error message. */
1742 print_candidates (tree fns)
1744 const char *str = NULL;
1745 print_candidates_1 (fns, false, &str);
1746 gcc_assert (str == NULL);
1749 /* Returns the template (one of the functions given by TEMPLATE_ID)
1750 which can be specialized to match the indicated DECL with the
1751 explicit template args given in TEMPLATE_ID. The DECL may be
1752 NULL_TREE if none is available. In that case, the functions in
1753 TEMPLATE_ID are non-members.
1755 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1756 specialization of a member template.
1758 The TEMPLATE_COUNT is the number of references to qualifying
1759 template classes that appeared in the name of the function. See
1760 check_explicit_specialization for a more accurate description.
1762 TSK indicates what kind of template declaration (if any) is being
1763 declared. TSK_TEMPLATE indicates that the declaration given by
1764 DECL, though a FUNCTION_DECL, has template parameters, and is
1765 therefore a template function.
1767 The template args (those explicitly specified and those deduced)
1768 are output in a newly created vector *TARGS_OUT.
1770 If it is impossible to determine the result, an error message is
1771 issued. The error_mark_node is returned to indicate failure. */
1774 determine_specialization (tree template_id,
1777 int need_member_template,
1783 tree explicit_targs;
1784 tree candidates = NULL_TREE;
1785 /* A TREE_LIST of templates of which DECL may be a specialization.
1786 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1787 corresponding TREE_PURPOSE is the set of template arguments that,
1788 when used to instantiate the template, would produce a function
1789 with the signature of DECL. */
1790 tree templates = NULL_TREE;
1792 struct cp_binding_level *b;
1794 *targs_out = NULL_TREE;
1796 if (template_id == error_mark_node || decl == error_mark_node)
1797 return error_mark_node;
1799 fns = TREE_OPERAND (template_id, 0);
1800 explicit_targs = TREE_OPERAND (template_id, 1);
1802 if (fns == error_mark_node)
1803 return error_mark_node;
1805 /* Check for baselinks. */
1806 if (BASELINK_P (fns))
1807 fns = BASELINK_FUNCTIONS (fns);
1809 if (!is_overloaded_fn (fns))
1811 error ("%qD is not a function template", fns);
1812 return error_mark_node;
1815 /* Count the number of template headers specified for this
1818 for (b = current_binding_level;
1819 b->kind == sk_template_parms;
1823 for (; fns; fns = OVL_NEXT (fns))
1825 tree fn = OVL_CURRENT (fns);
1827 if (TREE_CODE (fn) == TEMPLATE_DECL)
1829 tree decl_arg_types;
1832 /* In case of explicit specialization, we need to check if
1833 the number of template headers appearing in the specialization
1834 is correct. This is usually done in check_explicit_specialization,
1835 but the check done there cannot be exhaustive when specializing
1836 member functions. Consider the following code:
1838 template <> void A<int>::f(int);
1839 template <> template <> void A<int>::f(int);
1841 Assuming that A<int> is not itself an explicit specialization
1842 already, the first line specializes "f" which is a non-template
1843 member function, whilst the second line specializes "f" which
1844 is a template member function. So both lines are syntactically
1845 correct, and check_explicit_specialization does not reject
1848 Here, we can do better, as we are matching the specialization
1849 against the declarations. We count the number of template
1850 headers, and we check if they match TEMPLATE_COUNT + 1
1851 (TEMPLATE_COUNT is the number of qualifying template classes,
1852 plus there must be another header for the member template
1855 Notice that if header_count is zero, this is not a
1856 specialization but rather a template instantiation, so there
1857 is no check we can perform here. */
1858 if (header_count && header_count != template_count + 1)
1861 /* Check that the number of template arguments at the
1862 innermost level for DECL is the same as for FN. */
1863 if (current_binding_level->kind == sk_template_parms
1864 && !current_binding_level->explicit_spec_p
1865 && (TREE_VEC_LENGTH (DECL_INNERMOST_TEMPLATE_PARMS (fn))
1866 != TREE_VEC_LENGTH (INNERMOST_TEMPLATE_PARMS
1867 (current_template_parms))))
1870 /* DECL might be a specialization of FN. */
1871 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1872 fn_arg_types = TYPE_ARG_TYPES (TREE_TYPE (fn));
1874 /* For a non-static member function, we need to make sure
1875 that the const qualification is the same. Since
1876 get_bindings does not try to merge the "this" parameter,
1877 we must do the comparison explicitly. */
1878 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
1879 && !same_type_p (TREE_VALUE (fn_arg_types),
1880 TREE_VALUE (decl_arg_types)))
1883 /* Skip the "this" parameter and, for constructors of
1884 classes with virtual bases, the VTT parameter. A
1885 full specialization of a constructor will have a VTT
1886 parameter, but a template never will. */
1888 = skip_artificial_parms_for (decl, decl_arg_types);
1890 = skip_artificial_parms_for (fn, fn_arg_types);
1892 /* Check that the number of function parameters matches.
1894 template <class T> void f(int i = 0);
1895 template <> void f<int>();
1896 The specialization f<int> is invalid but is not caught
1897 by get_bindings below. */
1898 if (list_length (fn_arg_types) != list_length (decl_arg_types))
1901 /* Function templates cannot be specializations; there are
1902 no partial specializations of functions. Therefore, if
1903 the type of DECL does not match FN, there is no
1905 if (tsk == tsk_template)
1907 if (compparms (fn_arg_types, decl_arg_types))
1908 candidates = tree_cons (NULL_TREE, fn, candidates);
1912 /* See whether this function might be a specialization of this
1914 targs = get_bindings (fn, decl, explicit_targs, /*check_ret=*/true);
1917 /* We cannot deduce template arguments that when used to
1918 specialize TMPL will produce DECL. */
1921 /* Save this template, and the arguments deduced. */
1922 templates = tree_cons (targs, fn, templates);
1924 else if (need_member_template)
1925 /* FN is an ordinary member function, and we need a
1926 specialization of a member template. */
1928 else if (TREE_CODE (fn) != FUNCTION_DECL)
1929 /* We can get IDENTIFIER_NODEs here in certain erroneous
1932 else if (!DECL_FUNCTION_MEMBER_P (fn))
1933 /* This is just an ordinary non-member function. Nothing can
1934 be a specialization of that. */
1936 else if (DECL_ARTIFICIAL (fn))
1937 /* Cannot specialize functions that are created implicitly. */
1941 tree decl_arg_types;
1943 /* This is an ordinary member function. However, since
1944 we're here, we can assume it's enclosing class is a
1945 template class. For example,
1947 template <typename T> struct S { void f(); };
1948 template <> void S<int>::f() {}
1950 Here, S<int>::f is a non-template, but S<int> is a
1951 template class. If FN has the same type as DECL, we
1952 might be in business. */
1954 if (!DECL_TEMPLATE_INFO (fn))
1955 /* Its enclosing class is an explicit specialization
1956 of a template class. This is not a candidate. */
1959 if (!same_type_p (TREE_TYPE (TREE_TYPE (decl)),
1960 TREE_TYPE (TREE_TYPE (fn))))
1961 /* The return types differ. */
1964 /* Adjust the type of DECL in case FN is a static member. */
1965 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1966 if (DECL_STATIC_FUNCTION_P (fn)
1967 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1968 decl_arg_types = TREE_CHAIN (decl_arg_types);
1970 if (compparms (TYPE_ARG_TYPES (TREE_TYPE (fn)),
1973 candidates = tree_cons (NULL_TREE, fn, candidates);
1977 if (templates && TREE_CHAIN (templates))
1983 It is possible for a specialization with a given function
1984 signature to be instantiated from more than one function
1985 template. In such cases, explicit specification of the
1986 template arguments must be used to uniquely identify the
1987 function template specialization being specialized.
1989 Note that here, there's no suggestion that we're supposed to
1990 determine which of the candidate templates is most
1991 specialized. However, we, also have:
1995 Partial ordering of overloaded function template
1996 declarations is used in the following contexts to select
1997 the function template to which a function template
1998 specialization refers:
2000 -- when an explicit specialization refers to a function
2003 So, we do use the partial ordering rules, at least for now.
2004 This extension can only serve to make invalid programs valid,
2005 so it's safe. And, there is strong anecdotal evidence that
2006 the committee intended the partial ordering rules to apply;
2007 the EDG front end has that behavior, and John Spicer claims
2008 that the committee simply forgot to delete the wording in
2009 [temp.expl.spec]. */
2010 tree tmpl = most_specialized_instantiation (templates);
2011 if (tmpl != error_mark_node)
2014 TREE_CHAIN (templates) = NULL_TREE;
2018 if (templates == NULL_TREE && candidates == NULL_TREE)
2020 error ("template-id %qD for %q+D does not match any template "
2021 "declaration", template_id, decl);
2022 if (header_count && header_count != template_count + 1)
2023 inform (input_location, "saw %d %<template<>%>, need %d for "
2024 "specializing a member function template",
2025 header_count, template_count + 1);
2026 return error_mark_node;
2028 else if ((templates && TREE_CHAIN (templates))
2029 || (candidates && TREE_CHAIN (candidates))
2030 || (templates && candidates))
2032 error ("ambiguous template specialization %qD for %q+D",
2034 candidates = chainon (candidates, templates);
2035 print_candidates (candidates);
2036 return error_mark_node;
2039 /* We have one, and exactly one, match. */
2042 tree fn = TREE_VALUE (candidates);
2043 *targs_out = copy_node (DECL_TI_ARGS (fn));
2044 /* DECL is a re-declaration or partial instantiation of a template
2046 if (TREE_CODE (fn) == TEMPLATE_DECL)
2048 /* It was a specialization of an ordinary member function in a
2050 return DECL_TI_TEMPLATE (fn);
2053 /* It was a specialization of a template. */
2054 targs = DECL_TI_ARGS (DECL_TEMPLATE_RESULT (TREE_VALUE (templates)));
2055 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (targs))
2057 *targs_out = copy_node (targs);
2058 SET_TMPL_ARGS_LEVEL (*targs_out,
2059 TMPL_ARGS_DEPTH (*targs_out),
2060 TREE_PURPOSE (templates));
2063 *targs_out = TREE_PURPOSE (templates);
2064 return TREE_VALUE (templates);
2067 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2068 but with the default argument values filled in from those in the
2072 copy_default_args_to_explicit_spec_1 (tree spec_types,
2075 tree new_spec_types;
2080 if (spec_types == void_list_node)
2081 return void_list_node;
2083 /* Substitute into the rest of the list. */
2085 copy_default_args_to_explicit_spec_1 (TREE_CHAIN (spec_types),
2086 TREE_CHAIN (tmpl_types));
2088 /* Add the default argument for this parameter. */
2089 return hash_tree_cons (TREE_PURPOSE (tmpl_types),
2090 TREE_VALUE (spec_types),
2094 /* DECL is an explicit specialization. Replicate default arguments
2095 from the template it specializes. (That way, code like:
2097 template <class T> void f(T = 3);
2098 template <> void f(double);
2101 works, as required.) An alternative approach would be to look up
2102 the correct default arguments at the call-site, but this approach
2103 is consistent with how implicit instantiations are handled. */
2106 copy_default_args_to_explicit_spec (tree decl)
2111 tree new_spec_types;
2115 tree object_type = NULL_TREE;
2116 tree in_charge = NULL_TREE;
2117 tree vtt = NULL_TREE;
2119 /* See if there's anything we need to do. */
2120 tmpl = DECL_TI_TEMPLATE (decl);
2121 tmpl_types = TYPE_ARG_TYPES (TREE_TYPE (DECL_TEMPLATE_RESULT (tmpl)));
2122 for (t = tmpl_types; t; t = TREE_CHAIN (t))
2123 if (TREE_PURPOSE (t))
2128 old_type = TREE_TYPE (decl);
2129 spec_types = TYPE_ARG_TYPES (old_type);
2131 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2133 /* Remove the this pointer, but remember the object's type for
2135 object_type = TREE_TYPE (TREE_VALUE (spec_types));
2136 spec_types = TREE_CHAIN (spec_types);
2137 tmpl_types = TREE_CHAIN (tmpl_types);
2139 if (DECL_HAS_IN_CHARGE_PARM_P (decl))
2141 /* DECL may contain more parameters than TMPL due to the extra
2142 in-charge parameter in constructors and destructors. */
2143 in_charge = spec_types;
2144 spec_types = TREE_CHAIN (spec_types);
2146 if (DECL_HAS_VTT_PARM_P (decl))
2149 spec_types = TREE_CHAIN (spec_types);
2153 /* Compute the merged default arguments. */
2155 copy_default_args_to_explicit_spec_1 (spec_types, tmpl_types);
2157 /* Compute the new FUNCTION_TYPE. */
2161 new_spec_types = hash_tree_cons (TREE_PURPOSE (vtt),
2166 /* Put the in-charge parameter back. */
2167 new_spec_types = hash_tree_cons (TREE_PURPOSE (in_charge),
2168 TREE_VALUE (in_charge),
2171 new_type = build_method_type_directly (object_type,
2172 TREE_TYPE (old_type),
2176 new_type = build_function_type (TREE_TYPE (old_type),
2178 new_type = cp_build_type_attribute_variant (new_type,
2179 TYPE_ATTRIBUTES (old_type));
2180 new_type = build_exception_variant (new_type,
2181 TYPE_RAISES_EXCEPTIONS (old_type));
2182 TREE_TYPE (decl) = new_type;
2185 /* Check to see if the function just declared, as indicated in
2186 DECLARATOR, and in DECL, is a specialization of a function
2187 template. We may also discover that the declaration is an explicit
2188 instantiation at this point.
2190 Returns DECL, or an equivalent declaration that should be used
2191 instead if all goes well. Issues an error message if something is
2192 amiss. Returns error_mark_node if the error is not easily
2195 FLAGS is a bitmask consisting of the following flags:
2197 2: The function has a definition.
2198 4: The function is a friend.
2200 The TEMPLATE_COUNT is the number of references to qualifying
2201 template classes that appeared in the name of the function. For
2204 template <class T> struct S { void f(); };
2207 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2208 classes are not counted in the TEMPLATE_COUNT, so that in
2210 template <class T> struct S {};
2211 template <> struct S<int> { void f(); }
2212 template <> void S<int>::f();
2214 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2215 invalid; there should be no template <>.)
2217 If the function is a specialization, it is marked as such via
2218 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2219 is set up correctly, and it is added to the list of specializations
2220 for that template. */
2223 check_explicit_specialization (tree declarator,
2228 int have_def = flags & 2;
2229 int is_friend = flags & 4;
2230 int specialization = 0;
2231 int explicit_instantiation = 0;
2232 int member_specialization = 0;
2233 tree ctype = DECL_CLASS_CONTEXT (decl);
2234 tree dname = DECL_NAME (decl);
2239 if (!processing_specialization)
2242 tsk = tsk_excessive_parms;
2245 tsk = current_tmpl_spec_kind (template_count);
2250 if (processing_specialization)
2253 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2255 else if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2258 /* This could be something like:
2260 template <class T> void f(T);
2261 class S { friend void f<>(int); } */
2265 /* This case handles bogus declarations like template <>
2266 template <class T> void f<int>(); */
2268 error ("template-id %qD in declaration of primary template",
2275 case tsk_invalid_member_spec:
2276 /* The error has already been reported in
2277 check_specialization_scope. */
2278 return error_mark_node;
2280 case tsk_invalid_expl_inst:
2281 error ("template parameter list used in explicit instantiation");
2287 error ("definition provided for explicit instantiation");
2289 explicit_instantiation = 1;
2292 case tsk_excessive_parms:
2293 case tsk_insufficient_parms:
2294 if (tsk == tsk_excessive_parms)
2295 error ("too many template parameter lists in declaration of %qD",
2297 else if (template_header_count)
2298 error("too few template parameter lists in declaration of %qD", decl);
2300 error("explicit specialization of %qD must be introduced by "
2301 "%<template <>%>", decl);
2305 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2307 member_specialization = 1;
2313 if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2315 /* This case handles bogus declarations like template <>
2316 template <class T> void f<int>(); */
2318 if (uses_template_parms (declarator))
2319 error ("function template partial specialization %qD "
2320 "is not allowed", declarator);
2322 error ("template-id %qD in declaration of primary template",
2327 if (ctype && CLASSTYPE_TEMPLATE_INSTANTIATION (ctype))
2328 /* This is a specialization of a member template, without
2329 specialization the containing class. Something like:
2331 template <class T> struct S {
2332 template <class U> void f (U);
2334 template <> template <class U> void S<int>::f(U) {}
2336 That's a specialization -- but of the entire template. */
2344 if (specialization || member_specialization)
2346 tree t = TYPE_ARG_TYPES (TREE_TYPE (decl));
2347 for (; t; t = TREE_CHAIN (t))
2348 if (TREE_PURPOSE (t))
2350 permerror (input_location,
2351 "default argument specified in explicit specialization");
2356 if (specialization || member_specialization || explicit_instantiation)
2358 tree tmpl = NULL_TREE;
2359 tree targs = NULL_TREE;
2361 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2362 if (TREE_CODE (declarator) != TEMPLATE_ID_EXPR)
2366 gcc_assert (TREE_CODE (declarator) == IDENTIFIER_NODE);
2371 /* If there is no class context, the explicit instantiation
2372 must be at namespace scope. */
2373 gcc_assert (DECL_NAMESPACE_SCOPE_P (decl));
2375 /* Find the namespace binding, using the declaration
2377 fns = lookup_qualified_name (CP_DECL_CONTEXT (decl), dname,
2379 if (fns == error_mark_node || !is_overloaded_fn (fns))
2381 error ("%qD is not a template function", dname);
2382 fns = error_mark_node;
2386 tree fn = OVL_CURRENT (fns);
2387 if (!is_associated_namespace (CP_DECL_CONTEXT (decl),
2388 CP_DECL_CONTEXT (fn)))
2389 error ("%qD is not declared in %qD",
2390 decl, current_namespace);
2394 declarator = lookup_template_function (fns, NULL_TREE);
2397 if (declarator == error_mark_node)
2398 return error_mark_node;
2400 if (ctype != NULL_TREE && TYPE_BEING_DEFINED (ctype))
2402 if (!explicit_instantiation)
2403 /* A specialization in class scope. This is invalid,
2404 but the error will already have been flagged by
2405 check_specialization_scope. */
2406 return error_mark_node;
2409 /* It's not valid to write an explicit instantiation in
2412 class C { template void f(); }
2414 This case is caught by the parser. However, on
2417 template class C { void f(); };
2419 (which is invalid) we can get here. The error will be
2426 else if (ctype != NULL_TREE
2427 && (TREE_CODE (TREE_OPERAND (declarator, 0)) ==
2430 /* Find the list of functions in ctype that have the same
2431 name as the declared function. */
2432 tree name = TREE_OPERAND (declarator, 0);
2433 tree fns = NULL_TREE;
2436 if (constructor_name_p (name, ctype))
2438 int is_constructor = DECL_CONSTRUCTOR_P (decl);
2440 if (is_constructor ? !TYPE_HAS_USER_CONSTRUCTOR (ctype)
2441 : !CLASSTYPE_DESTRUCTORS (ctype))
2443 /* From [temp.expl.spec]:
2445 If such an explicit specialization for the member
2446 of a class template names an implicitly-declared
2447 special member function (clause _special_), the
2448 program is ill-formed.
2450 Similar language is found in [temp.explicit]. */
2451 error ("specialization of implicitly-declared special member function");
2452 return error_mark_node;
2455 name = is_constructor ? ctor_identifier : dtor_identifier;
2458 if (!DECL_CONV_FN_P (decl))
2460 idx = lookup_fnfields_1 (ctype, name);
2462 fns = VEC_index (tree, CLASSTYPE_METHOD_VEC (ctype), idx);
2466 VEC(tree,gc) *methods;
2469 /* For a type-conversion operator, we cannot do a
2470 name-based lookup. We might be looking for `operator
2471 int' which will be a specialization of `operator T'.
2472 So, we find *all* the conversion operators, and then
2473 select from them. */
2476 methods = CLASSTYPE_METHOD_VEC (ctype);
2478 for (idx = CLASSTYPE_FIRST_CONVERSION_SLOT;
2479 VEC_iterate (tree, methods, idx, ovl);
2482 if (!DECL_CONV_FN_P (OVL_CURRENT (ovl)))
2483 /* There are no more conversion functions. */
2486 /* Glue all these conversion functions together
2487 with those we already have. */
2488 for (; ovl; ovl = OVL_NEXT (ovl))
2489 fns = ovl_cons (OVL_CURRENT (ovl), fns);
2493 if (fns == NULL_TREE)
2495 error ("no member function %qD declared in %qT", name, ctype);
2496 return error_mark_node;
2499 TREE_OPERAND (declarator, 0) = fns;
2502 /* Figure out what exactly is being specialized at this point.
2503 Note that for an explicit instantiation, even one for a
2504 member function, we cannot tell apriori whether the
2505 instantiation is for a member template, or just a member
2506 function of a template class. Even if a member template is
2507 being instantiated, the member template arguments may be
2508 elided if they can be deduced from the rest of the
2510 tmpl = determine_specialization (declarator, decl,
2512 member_specialization,
2516 if (!tmpl || tmpl == error_mark_node)
2517 /* We couldn't figure out what this declaration was
2519 return error_mark_node;
2522 tree gen_tmpl = most_general_template (tmpl);
2524 if (explicit_instantiation)
2526 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2527 is done by do_decl_instantiation later. */
2529 int arg_depth = TMPL_ARGS_DEPTH (targs);
2530 int parm_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
2532 if (arg_depth > parm_depth)
2534 /* If TMPL is not the most general template (for
2535 example, if TMPL is a friend template that is
2536 injected into namespace scope), then there will
2537 be too many levels of TARGS. Remove some of them
2542 new_targs = make_tree_vec (parm_depth);
2543 for (i = arg_depth - parm_depth; i < arg_depth; ++i)
2544 TREE_VEC_ELT (new_targs, i - (arg_depth - parm_depth))
2545 = TREE_VEC_ELT (targs, i);
2549 return instantiate_template (tmpl, targs, tf_error);
2552 /* If we thought that the DECL was a member function, but it
2553 turns out to be specializing a static member function,
2554 make DECL a static member function as well. */
2555 if (DECL_STATIC_FUNCTION_P (tmpl)
2556 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2557 revert_static_member_fn (decl);
2559 /* If this is a specialization of a member template of a
2560 template class, we want to return the TEMPLATE_DECL, not
2561 the specialization of it. */
2562 if (tsk == tsk_template)
2564 tree result = DECL_TEMPLATE_RESULT (tmpl);
2565 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
2566 DECL_INITIAL (result) = NULL_TREE;
2570 DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl);
2571 DECL_SOURCE_LOCATION (result)
2572 = DECL_SOURCE_LOCATION (decl);
2573 /* We want to use the argument list specified in the
2574 definition, not in the original declaration. */
2575 DECL_ARGUMENTS (result) = DECL_ARGUMENTS (decl);
2576 for (parm = DECL_ARGUMENTS (result); parm;
2577 parm = DECL_CHAIN (parm))
2578 DECL_CONTEXT (parm) = result;
2580 return register_specialization (tmpl, gen_tmpl, targs,
2584 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2585 DECL_TEMPLATE_INFO (decl) = build_template_info (tmpl, targs);
2587 /* Inherit default function arguments from the template
2588 DECL is specializing. */
2589 copy_default_args_to_explicit_spec (decl);
2591 /* This specialization has the same protection as the
2592 template it specializes. */
2593 TREE_PRIVATE (decl) = TREE_PRIVATE (gen_tmpl);
2594 TREE_PROTECTED (decl) = TREE_PROTECTED (gen_tmpl);
2596 /* 7.1.1-1 [dcl.stc]
2598 A storage-class-specifier shall not be specified in an
2599 explicit specialization...
2601 The parser rejects these, so unless action is taken here,
2602 explicit function specializations will always appear with
2605 The action recommended by the C++ CWG in response to C++
2606 defect report 605 is to make the storage class and linkage
2607 of the explicit specialization match the templated function:
2609 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2611 if (tsk == tsk_expl_spec && DECL_FUNCTION_TEMPLATE_P (gen_tmpl))
2613 tree tmpl_func = DECL_TEMPLATE_RESULT (gen_tmpl);
2614 gcc_assert (TREE_CODE (tmpl_func) == FUNCTION_DECL);
2616 /* This specialization has the same linkage and visibility as
2617 the function template it specializes. */
2618 TREE_PUBLIC (decl) = TREE_PUBLIC (tmpl_func);
2619 if (! TREE_PUBLIC (decl))
2621 DECL_INTERFACE_KNOWN (decl) = 1;
2622 DECL_NOT_REALLY_EXTERN (decl) = 1;
2624 DECL_THIS_STATIC (decl) = DECL_THIS_STATIC (tmpl_func);
2625 if (DECL_VISIBILITY_SPECIFIED (tmpl_func))
2627 DECL_VISIBILITY_SPECIFIED (decl) = 1;
2628 DECL_VISIBILITY (decl) = DECL_VISIBILITY (tmpl_func);
2632 /* If DECL is a friend declaration, declared using an
2633 unqualified name, the namespace associated with DECL may
2634 have been set incorrectly. For example, in:
2636 template <typename T> void f(T);
2638 struct S { friend void f<int>(int); }
2641 we will have set the DECL_CONTEXT for the friend
2642 declaration to N, rather than to the global namespace. */
2643 if (DECL_NAMESPACE_SCOPE_P (decl))
2644 DECL_CONTEXT (decl) = DECL_CONTEXT (tmpl);
2646 if (is_friend && !have_def)
2647 /* This is not really a declaration of a specialization.
2648 It's just the name of an instantiation. But, it's not
2649 a request for an instantiation, either. */
2650 SET_DECL_IMPLICIT_INSTANTIATION (decl);
2651 else if (DECL_CONSTRUCTOR_P (decl) || DECL_DESTRUCTOR_P (decl))
2652 /* This is indeed a specialization. In case of constructors
2653 and destructors, we need in-charge and not-in-charge
2654 versions in V3 ABI. */
2655 clone_function_decl (decl, /*update_method_vec_p=*/0);
2657 /* Register this specialization so that we can find it
2659 decl = register_specialization (decl, gen_tmpl, targs, is_friend, 0);
2666 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2667 parameters. These are represented in the same format used for
2668 DECL_TEMPLATE_PARMS. */
2671 comp_template_parms (const_tree parms1, const_tree parms2)
2676 if (parms1 == parms2)
2679 for (p1 = parms1, p2 = parms2;
2680 p1 != NULL_TREE && p2 != NULL_TREE;
2681 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2))
2683 tree t1 = TREE_VALUE (p1);
2684 tree t2 = TREE_VALUE (p2);
2687 gcc_assert (TREE_CODE (t1) == TREE_VEC);
2688 gcc_assert (TREE_CODE (t2) == TREE_VEC);
2690 if (TREE_VEC_LENGTH (t1) != TREE_VEC_LENGTH (t2))
2693 for (i = 0; i < TREE_VEC_LENGTH (t2); ++i)
2695 tree parm1 = TREE_VALUE (TREE_VEC_ELT (t1, i));
2696 tree parm2 = TREE_VALUE (TREE_VEC_ELT (t2, i));
2698 /* If either of the template parameters are invalid, assume
2699 they match for the sake of error recovery. */
2700 if (parm1 == error_mark_node || parm2 == error_mark_node)
2703 if (TREE_CODE (parm1) != TREE_CODE (parm2))
2706 if (TREE_CODE (parm1) == TEMPLATE_TYPE_PARM
2707 && (TEMPLATE_TYPE_PARAMETER_PACK (parm1)
2708 == TEMPLATE_TYPE_PARAMETER_PACK (parm2)))
2710 else if (!same_type_p (TREE_TYPE (parm1), TREE_TYPE (parm2)))
2715 if ((p1 != NULL_TREE) != (p2 != NULL_TREE))
2716 /* One set of parameters has more parameters lists than the
2723 /* Determine whether PARM is a parameter pack. */
2726 template_parameter_pack_p (const_tree parm)
2728 /* Determine if we have a non-type template parameter pack. */
2729 if (TREE_CODE (parm) == PARM_DECL)
2730 return (DECL_TEMPLATE_PARM_P (parm)
2731 && TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)));
2733 /* If this is a list of template parameters, we could get a
2734 TYPE_DECL or a TEMPLATE_DECL. */
2735 if (TREE_CODE (parm) == TYPE_DECL || TREE_CODE (parm) == TEMPLATE_DECL)
2736 parm = TREE_TYPE (parm);
2738 return ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
2739 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM)
2740 && TEMPLATE_TYPE_PARAMETER_PACK (parm));
2743 /* Determine if T is a function parameter pack. */
2746 function_parameter_pack_p (const_tree t)
2748 if (t && TREE_CODE (t) == PARM_DECL)
2749 return FUNCTION_PARAMETER_PACK_P (t);
2753 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2754 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2757 get_function_template_decl (const_tree primary_func_tmpl_inst)
2759 if (! primary_func_tmpl_inst
2760 || TREE_CODE (primary_func_tmpl_inst) != FUNCTION_DECL
2761 || ! primary_template_instantiation_p (primary_func_tmpl_inst))
2764 return DECL_TEMPLATE_RESULT (DECL_TI_TEMPLATE (primary_func_tmpl_inst));
2767 /* Return true iff the function parameter PARAM_DECL was expanded
2768 from the function parameter pack PACK. */
2771 function_parameter_expanded_from_pack_p (tree param_decl, tree pack)
2773 if (DECL_ARTIFICIAL (param_decl)
2774 || !function_parameter_pack_p (pack))
2777 /* The parameter pack and its pack arguments have the same
2779 return DECL_PARM_INDEX (pack) == DECL_PARM_INDEX (param_decl);
2782 /* Determine whether ARGS describes a variadic template args list,
2783 i.e., one that is terminated by a template argument pack. */
2786 template_args_variadic_p (tree args)
2791 if (args == NULL_TREE)
2794 args = INNERMOST_TEMPLATE_ARGS (args);
2795 nargs = TREE_VEC_LENGTH (args);
2800 last_parm = TREE_VEC_ELT (args, nargs - 1);
2802 return ARGUMENT_PACK_P (last_parm);
2805 /* Generate a new name for the parameter pack name NAME (an
2806 IDENTIFIER_NODE) that incorporates its */
2809 make_ith_pack_parameter_name (tree name, int i)
2811 /* Munge the name to include the parameter index. */
2812 #define NUMBUF_LEN 128
2813 char numbuf[NUMBUF_LEN];
2817 snprintf (numbuf, NUMBUF_LEN, "%i", i);
2818 newname_len = IDENTIFIER_LENGTH (name)
2819 + strlen (numbuf) + 2;
2820 newname = (char*)alloca (newname_len);
2821 snprintf (newname, newname_len,
2822 "%s#%i", IDENTIFIER_POINTER (name), i);
2823 return get_identifier (newname);
2826 /* Return true if T is a primary function
2827 or class template instantiation. */
2830 primary_template_instantiation_p (const_tree t)
2835 if (TREE_CODE (t) == FUNCTION_DECL)
2836 return DECL_LANG_SPECIFIC (t)
2837 && DECL_TEMPLATE_INSTANTIATION (t)
2838 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (t));
2839 else if (CLASS_TYPE_P (t))
2840 return CLASSTYPE_TEMPLATE_INSTANTIATION (t)
2841 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (t));
2845 /* Return true if PARM is a template template parameter. */
2848 template_template_parameter_p (const_tree parm)
2850 return DECL_TEMPLATE_TEMPLATE_PARM_P (parm);
2853 /* Return the template parameters of T if T is a
2854 primary template instantiation, NULL otherwise. */
2857 get_primary_template_innermost_parameters (const_tree t)
2859 tree parms = NULL, template_info = NULL;
2861 if ((template_info = get_template_info (t))
2862 && primary_template_instantiation_p (t))
2863 parms = INNERMOST_TEMPLATE_PARMS
2864 (DECL_TEMPLATE_PARMS (TI_TEMPLATE (template_info)));
2869 /* Return the template parameters of the LEVELth level from the full list
2870 of template parameters PARMS. */
2873 get_template_parms_at_level (tree parms, int level)
2877 || TREE_CODE (parms) != TREE_LIST
2878 || level > TMPL_PARMS_DEPTH (parms))
2881 for (p = parms; p; p = TREE_CHAIN (p))
2882 if (TMPL_PARMS_DEPTH (p) == level)
2888 /* Returns the template arguments of T if T is a template instantiation,
2892 get_template_innermost_arguments (const_tree t)
2894 tree args = NULL, template_info = NULL;
2896 if ((template_info = get_template_info (t))
2897 && TI_ARGS (template_info))
2898 args = INNERMOST_TEMPLATE_ARGS (TI_ARGS (template_info));
2903 /* Return the argument pack elements of T if T is a template argument pack,
2907 get_template_argument_pack_elems (const_tree t)
2909 if (TREE_CODE (t) != TYPE_ARGUMENT_PACK
2910 && TREE_CODE (t) != NONTYPE_ARGUMENT_PACK)
2913 return ARGUMENT_PACK_ARGS (t);
2916 /* Structure used to track the progress of find_parameter_packs_r. */
2917 struct find_parameter_pack_data
2919 /* TREE_LIST that will contain all of the parameter packs found by
2921 tree* parameter_packs;
2923 /* Set of AST nodes that have been visited by the traversal. */
2924 struct pointer_set_t *visited;
2927 /* Identifies all of the argument packs that occur in a template
2928 argument and appends them to the TREE_LIST inside DATA, which is a
2929 find_parameter_pack_data structure. This is a subroutine of
2930 make_pack_expansion and uses_parameter_packs. */
2932 find_parameter_packs_r (tree *tp, int *walk_subtrees, void* data)
2935 struct find_parameter_pack_data* ppd =
2936 (struct find_parameter_pack_data*)data;
2937 bool parameter_pack_p = false;
2939 /* Identify whether this is a parameter pack or not. */
2940 switch (TREE_CODE (t))
2942 case TEMPLATE_PARM_INDEX:
2943 if (TEMPLATE_PARM_PARAMETER_PACK (t))
2944 parameter_pack_p = true;
2947 case TEMPLATE_TYPE_PARM:
2948 case TEMPLATE_TEMPLATE_PARM:
2949 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
2950 parameter_pack_p = true;
2954 if (FUNCTION_PARAMETER_PACK_P (t))
2956 /* We don't want to walk into the type of a PARM_DECL,
2957 because we don't want to see the type parameter pack. */
2959 parameter_pack_p = true;
2964 /* Not a parameter pack. */
2968 if (parameter_pack_p)
2970 /* Add this parameter pack to the list. */
2971 *ppd->parameter_packs = tree_cons (NULL_TREE, t, *ppd->parameter_packs);
2975 cp_walk_tree (&TYPE_CONTEXT (t),
2976 &find_parameter_packs_r, ppd, ppd->visited);
2978 /* This switch statement will return immediately if we don't find a
2980 switch (TREE_CODE (t))
2982 case TEMPLATE_PARM_INDEX:
2985 case BOUND_TEMPLATE_TEMPLATE_PARM:
2986 /* Check the template itself. */
2987 cp_walk_tree (&TREE_TYPE (TYPE_TI_TEMPLATE (t)),
2988 &find_parameter_packs_r, ppd, ppd->visited);
2989 /* Check the template arguments. */
2990 cp_walk_tree (&TYPE_TI_ARGS (t), &find_parameter_packs_r, ppd,
2995 case TEMPLATE_TYPE_PARM:
2996 case TEMPLATE_TEMPLATE_PARM:
3003 if (TYPE_PTRMEMFUNC_P (t))
3009 if (TYPE_TEMPLATE_INFO (t))
3010 cp_walk_tree (&TI_ARGS (TYPE_TEMPLATE_INFO (t)),
3011 &find_parameter_packs_r, ppd, ppd->visited);
3017 cp_walk_tree (&TREE_TYPE (t),
3018 &find_parameter_packs_r, ppd, ppd->visited);
3022 cp_walk_tree (&TYPENAME_TYPE_FULLNAME (t), &find_parameter_packs_r,
3027 case TYPE_PACK_EXPANSION:
3028 case EXPR_PACK_EXPANSION:
3033 cp_walk_tree (&TYPE_MAX_VALUE (t), &find_parameter_packs_r,
3038 case IDENTIFIER_NODE:
3039 cp_walk_tree (&TREE_TYPE (t), &find_parameter_packs_r, ppd,
3051 /* Determines if the expression or type T uses any parameter packs. */
3053 uses_parameter_packs (tree t)
3055 tree parameter_packs = NULL_TREE;
3056 struct find_parameter_pack_data ppd;
3057 ppd.parameter_packs = ¶meter_packs;
3058 ppd.visited = pointer_set_create ();
3059 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
3060 pointer_set_destroy (ppd.visited);
3061 return parameter_packs != NULL_TREE;
3064 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3065 representation a base-class initializer into a parameter pack
3066 expansion. If all goes well, the resulting node will be an
3067 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3070 make_pack_expansion (tree arg)
3073 tree parameter_packs = NULL_TREE;
3074 bool for_types = false;
3075 struct find_parameter_pack_data ppd;
3077 if (!arg || arg == error_mark_node)
3080 if (TREE_CODE (arg) == TREE_LIST)
3082 /* The only time we will see a TREE_LIST here is for a base
3083 class initializer. In this case, the TREE_PURPOSE will be a
3084 _TYPE node (representing the base class expansion we're
3085 initializing) and the TREE_VALUE will be a TREE_LIST
3086 containing the initialization arguments.
3088 The resulting expansion looks somewhat different from most
3089 expansions. Rather than returning just one _EXPANSION, we
3090 return a TREE_LIST whose TREE_PURPOSE is a
3091 TYPE_PACK_EXPANSION containing the bases that will be
3092 initialized. The TREE_VALUE will be identical to the
3093 original TREE_VALUE, which is a list of arguments that will
3094 be passed to each base. We do not introduce any new pack
3095 expansion nodes into the TREE_VALUE (although it is possible
3096 that some already exist), because the TREE_PURPOSE and
3097 TREE_VALUE all need to be expanded together with the same
3098 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3099 resulting TREE_PURPOSE will mention the parameter packs in
3100 both the bases and the arguments to the bases. */
3103 tree parameter_packs = NULL_TREE;
3105 /* Determine which parameter packs will be used by the base
3107 ppd.visited = pointer_set_create ();
3108 ppd.parameter_packs = ¶meter_packs;
3109 cp_walk_tree (&TREE_PURPOSE (arg), &find_parameter_packs_r,
3112 if (parameter_packs == NULL_TREE)
3114 error ("base initializer expansion %<%T%> contains no parameter packs", arg);
3115 pointer_set_destroy (ppd.visited);
3116 return error_mark_node;
3119 if (TREE_VALUE (arg) != void_type_node)
3121 /* Collect the sets of parameter packs used in each of the
3122 initialization arguments. */
3123 for (value = TREE_VALUE (arg); value; value = TREE_CHAIN (value))
3125 /* Determine which parameter packs will be expanded in this
3127 cp_walk_tree (&TREE_VALUE (value), &find_parameter_packs_r,
3132 pointer_set_destroy (ppd.visited);
3134 /* Create the pack expansion type for the base type. */
3135 purpose = cxx_make_type (TYPE_PACK_EXPANSION);
3136 SET_PACK_EXPANSION_PATTERN (purpose, TREE_PURPOSE (arg));
3137 PACK_EXPANSION_PARAMETER_PACKS (purpose) = parameter_packs;
3139 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3140 they will rarely be compared to anything. */
3141 SET_TYPE_STRUCTURAL_EQUALITY (purpose);
3143 return tree_cons (purpose, TREE_VALUE (arg), NULL_TREE);
3146 if (TYPE_P (arg) || TREE_CODE (arg) == TEMPLATE_DECL)
3149 /* Build the PACK_EXPANSION_* node. */
3151 ? cxx_make_type (TYPE_PACK_EXPANSION)
3152 : make_node (EXPR_PACK_EXPANSION);
3153 SET_PACK_EXPANSION_PATTERN (result, arg);
3154 if (TREE_CODE (result) == EXPR_PACK_EXPANSION)
3156 /* Propagate type and const-expression information. */
3157 TREE_TYPE (result) = TREE_TYPE (arg);
3158 TREE_CONSTANT (result) = TREE_CONSTANT (arg);
3161 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3162 they will rarely be compared to anything. */
3163 SET_TYPE_STRUCTURAL_EQUALITY (result);
3165 /* Determine which parameter packs will be expanded. */
3166 ppd.parameter_packs = ¶meter_packs;
3167 ppd.visited = pointer_set_create ();
3168 cp_walk_tree (&arg, &find_parameter_packs_r, &ppd, ppd.visited);
3169 pointer_set_destroy (ppd.visited);
3171 /* Make sure we found some parameter packs. */
3172 if (parameter_packs == NULL_TREE)
3175 error ("expansion pattern %<%T%> contains no argument packs", arg);
3177 error ("expansion pattern %<%E%> contains no argument packs", arg);
3178 return error_mark_node;
3180 PACK_EXPANSION_PARAMETER_PACKS (result) = parameter_packs;
3185 /* Checks T for any "bare" parameter packs, which have not yet been
3186 expanded, and issues an error if any are found. This operation can
3187 only be done on full expressions or types (e.g., an expression
3188 statement, "if" condition, etc.), because we could have expressions like:
3190 foo(f(g(h(args)))...)
3192 where "args" is a parameter pack. check_for_bare_parameter_packs
3193 should not be called for the subexpressions args, h(args),
3194 g(h(args)), or f(g(h(args))), because we would produce erroneous
3197 Returns TRUE and emits an error if there were bare parameter packs,
3198 returns FALSE otherwise. */
3200 check_for_bare_parameter_packs (tree t)
3202 tree parameter_packs = NULL_TREE;
3203 struct find_parameter_pack_data ppd;
3205 if (!processing_template_decl || !t || t == error_mark_node)
3208 if (TREE_CODE (t) == TYPE_DECL)
3211 ppd.parameter_packs = ¶meter_packs;
3212 ppd.visited = pointer_set_create ();
3213 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
3214 pointer_set_destroy (ppd.visited);
3216 if (parameter_packs)
3218 error ("parameter packs not expanded with %<...%>:");
3219 while (parameter_packs)
3221 tree pack = TREE_VALUE (parameter_packs);
3222 tree name = NULL_TREE;
3224 if (TREE_CODE (pack) == TEMPLATE_TYPE_PARM
3225 || TREE_CODE (pack) == TEMPLATE_TEMPLATE_PARM)
3226 name = TYPE_NAME (pack);
3227 else if (TREE_CODE (pack) == TEMPLATE_PARM_INDEX)
3228 name = DECL_NAME (TEMPLATE_PARM_DECL (pack));
3230 name = DECL_NAME (pack);
3233 inform (input_location, " %qD", name);
3235 inform (input_location, " <anonymous>");
3237 parameter_packs = TREE_CHAIN (parameter_packs);
3246 /* Expand any parameter packs that occur in the template arguments in
3249 expand_template_argument_pack (tree args)
3251 tree result_args = NULL_TREE;
3252 int in_arg, out_arg = 0, nargs = args ? TREE_VEC_LENGTH (args) : 0;
3253 int num_result_args = -1;
3254 int non_default_args_count = -1;
3256 /* First, determine if we need to expand anything, and the number of
3257 slots we'll need. */
3258 for (in_arg = 0; in_arg < nargs; ++in_arg)
3260 tree arg = TREE_VEC_ELT (args, in_arg);
3261 if (arg == NULL_TREE)
3263 if (ARGUMENT_PACK_P (arg))
3265 int num_packed = TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg));
3266 if (num_result_args < 0)
3267 num_result_args = in_arg + num_packed;
3269 num_result_args += num_packed;
3273 if (num_result_args >= 0)
3278 /* If no expansion is necessary, we're done. */
3279 if (num_result_args < 0)
3282 /* Expand arguments. */
3283 result_args = make_tree_vec (num_result_args);
3284 if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (args))
3285 non_default_args_count =
3286 GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (args);
3287 for (in_arg = 0; in_arg < nargs; ++in_arg)
3289 tree arg = TREE_VEC_ELT (args, in_arg);
3290 if (ARGUMENT_PACK_P (arg))
3292 tree packed = ARGUMENT_PACK_ARGS (arg);
3293 int i, num_packed = TREE_VEC_LENGTH (packed);
3294 for (i = 0; i < num_packed; ++i, ++out_arg)
3295 TREE_VEC_ELT (result_args, out_arg) = TREE_VEC_ELT(packed, i);
3296 if (non_default_args_count > 0)
3297 non_default_args_count += num_packed;
3301 TREE_VEC_ELT (result_args, out_arg) = arg;
3305 if (non_default_args_count >= 0)
3306 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (result_args, non_default_args_count);
3310 /* Checks if DECL shadows a template parameter.
3312 [temp.local]: A template-parameter shall not be redeclared within its
3313 scope (including nested scopes).
3315 Emits an error and returns TRUE if the DECL shadows a parameter,
3316 returns FALSE otherwise. */
3319 check_template_shadow (tree decl)
3323 /* If we're not in a template, we can't possibly shadow a template
3325 if (!current_template_parms)
3328 /* Figure out what we're shadowing. */
3329 if (TREE_CODE (decl) == OVERLOAD)
3330 decl = OVL_CURRENT (decl);
3331 olddecl = innermost_non_namespace_value (DECL_NAME (decl));
3333 /* If there's no previous binding for this name, we're not shadowing
3334 anything, let alone a template parameter. */
3338 /* If we're not shadowing a template parameter, we're done. Note
3339 that OLDDECL might be an OVERLOAD (or perhaps even an
3340 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3342 if (!DECL_P (olddecl) || !DECL_TEMPLATE_PARM_P (olddecl))
3345 /* We check for decl != olddecl to avoid bogus errors for using a
3346 name inside a class. We check TPFI to avoid duplicate errors for
3347 inline member templates. */
3349 || TEMPLATE_PARMS_FOR_INLINE (current_template_parms))
3352 error ("declaration of %q+#D", decl);
3353 error (" shadows template parm %q+#D", olddecl);
3357 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3358 ORIG_LEVEL, DECL, and TYPE. NUM_SIBLINGS is the total number of
3359 template parameters. */
3362 build_template_parm_index (int index,
3369 tree t = make_node (TEMPLATE_PARM_INDEX);
3370 TEMPLATE_PARM_IDX (t) = index;
3371 TEMPLATE_PARM_LEVEL (t) = level;
3372 TEMPLATE_PARM_ORIG_LEVEL (t) = orig_level;
3373 TEMPLATE_PARM_NUM_SIBLINGS (t) = num_siblings;
3374 TEMPLATE_PARM_DECL (t) = decl;
3375 TREE_TYPE (t) = type;
3376 TREE_CONSTANT (t) = TREE_CONSTANT (decl);
3377 TREE_READONLY (t) = TREE_READONLY (decl);
3382 /* Find the canonical type parameter for the given template type
3383 parameter. Returns the canonical type parameter, which may be TYPE
3384 if no such parameter existed. */
3387 canonical_type_parameter (tree type)
3390 int idx = TEMPLATE_TYPE_IDX (type);
3391 if (!canonical_template_parms)
3392 canonical_template_parms = VEC_alloc (tree, gc, idx+1);
3394 while (VEC_length (tree, canonical_template_parms) <= (unsigned)idx)
3395 VEC_safe_push (tree, gc, canonical_template_parms, NULL_TREE);
3397 list = VEC_index (tree, canonical_template_parms, idx);
3398 while (list && !comptypes (type, TREE_VALUE (list), COMPARE_STRUCTURAL))
3399 list = TREE_CHAIN (list);
3402 return TREE_VALUE (list);
3405 VEC_replace(tree, canonical_template_parms, idx,
3406 tree_cons (NULL_TREE, type,
3407 VEC_index (tree, canonical_template_parms, idx)));
3412 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3413 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3414 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3415 new one is created. */
3418 reduce_template_parm_level (tree index, tree type, int levels, tree args,
3419 tsubst_flags_t complain)
3421 if (TEMPLATE_PARM_DESCENDANTS (index) == NULL_TREE
3422 || (TEMPLATE_PARM_LEVEL (TEMPLATE_PARM_DESCENDANTS (index))
3423 != TEMPLATE_PARM_LEVEL (index) - levels)
3424 || !same_type_p (type, TREE_TYPE (TEMPLATE_PARM_DESCENDANTS (index))))
3426 tree orig_decl = TEMPLATE_PARM_DECL (index);
3429 decl = build_decl (DECL_SOURCE_LOCATION (orig_decl),
3430 TREE_CODE (orig_decl), DECL_NAME (orig_decl), type);
3431 TREE_CONSTANT (decl) = TREE_CONSTANT (orig_decl);
3432 TREE_READONLY (decl) = TREE_READONLY (orig_decl);
3433 DECL_ARTIFICIAL (decl) = 1;
3434 SET_DECL_TEMPLATE_PARM_P (decl);
3436 t = build_template_parm_index (TEMPLATE_PARM_IDX (index),
3437 TEMPLATE_PARM_LEVEL (index) - levels,
3438 TEMPLATE_PARM_ORIG_LEVEL (index),
3439 TEMPLATE_PARM_NUM_SIBLINGS (index),
3441 TEMPLATE_PARM_DESCENDANTS (index) = t;
3442 TEMPLATE_PARM_PARAMETER_PACK (t)
3443 = TEMPLATE_PARM_PARAMETER_PACK (index);
3445 /* Template template parameters need this. */
3446 if (TREE_CODE (decl) == TEMPLATE_DECL)
3447 DECL_TEMPLATE_PARMS (decl) = tsubst_template_parms
3448 (DECL_TEMPLATE_PARMS (TEMPLATE_PARM_DECL (index)),
3452 return TEMPLATE_PARM_DESCENDANTS (index);
3455 /* Process information from new template parameter PARM and append it
3456 to the LIST being built. This new parameter is a non-type
3457 parameter iff IS_NON_TYPE is true. This new parameter is a
3458 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3459 is in PARM_LOC. NUM_TEMPLATE_PARMS is the size of the template
3460 parameter list PARM belongs to. This is used used to create a
3461 proper canonical type for the type of PARM that is to be created,
3462 iff PARM is a type. If the size is not known, this parameter shall
3466 process_template_parm (tree list, location_t parm_loc, tree parm,
3467 bool is_non_type, bool is_parameter_pack,
3468 unsigned num_template_parms)
3475 gcc_assert (TREE_CODE (parm) == TREE_LIST);
3476 defval = TREE_PURPOSE (parm);
3480 tree p = tree_last (list);
3482 if (p && TREE_VALUE (p) != error_mark_node)
3485 if (TREE_CODE (p) == TYPE_DECL || TREE_CODE (p) == TEMPLATE_DECL)
3486 idx = TEMPLATE_TYPE_IDX (TREE_TYPE (p));
3488 idx = TEMPLATE_PARM_IDX (DECL_INITIAL (p));
3498 parm = TREE_VALUE (parm);
3500 SET_DECL_TEMPLATE_PARM_P (parm);
3502 if (TREE_TYPE (parm) == error_mark_node)
3504 err_parm_list = build_tree_list (defval, parm);
3505 TREE_VALUE (err_parm_list) = error_mark_node;
3506 return chainon (list, err_parm_list);
3512 The top-level cv-qualifiers on the template-parameter are
3513 ignored when determining its type. */
3514 TREE_TYPE (parm) = TYPE_MAIN_VARIANT (TREE_TYPE (parm));
3515 if (invalid_nontype_parm_type_p (TREE_TYPE (parm), 1))
3517 err_parm_list = build_tree_list (defval, parm);
3518 TREE_VALUE (err_parm_list) = error_mark_node;
3519 return chainon (list, err_parm_list);
3522 if (uses_parameter_packs (TREE_TYPE (parm)) && !is_parameter_pack)
3524 /* This template parameter is not a parameter pack, but it
3525 should be. Complain about "bare" parameter packs. */
3526 check_for_bare_parameter_packs (TREE_TYPE (parm));
3528 /* Recover by calling this a parameter pack. */
3529 is_parameter_pack = true;
3533 /* A template parameter is not modifiable. */
3534 TREE_CONSTANT (parm) = 1;
3535 TREE_READONLY (parm) = 1;
3536 decl = build_decl (parm_loc,
3537 CONST_DECL, DECL_NAME (parm), TREE_TYPE (parm));
3538 TREE_CONSTANT (decl) = 1;
3539 TREE_READONLY (decl) = 1;
3540 DECL_INITIAL (parm) = DECL_INITIAL (decl)
3541 = build_template_parm_index (idx, processing_template_decl,
3542 processing_template_decl,
3544 decl, TREE_TYPE (parm));
3546 TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))
3547 = is_parameter_pack;
3552 parm = TREE_VALUE (TREE_VALUE (parm));
3554 if (parm && TREE_CODE (parm) == TEMPLATE_DECL)
3556 t = cxx_make_type (TEMPLATE_TEMPLATE_PARM);
3557 /* This is for distinguishing between real templates and template
3558 template parameters */
3559 TREE_TYPE (parm) = t;
3560 TREE_TYPE (DECL_TEMPLATE_RESULT (parm)) = t;
3565 t = cxx_make_type (TEMPLATE_TYPE_PARM);
3566 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3567 decl = build_decl (parm_loc,
3568 TYPE_DECL, parm, t);
3571 TYPE_NAME (t) = decl;
3572 TYPE_STUB_DECL (t) = decl;
3574 TEMPLATE_TYPE_PARM_INDEX (t)
3575 = build_template_parm_index (idx, processing_template_decl,
3576 processing_template_decl,
3578 decl, TREE_TYPE (parm));
3579 TEMPLATE_TYPE_PARAMETER_PACK (t) = is_parameter_pack;
3580 TYPE_CANONICAL (t) = canonical_type_parameter (t);
3582 DECL_ARTIFICIAL (decl) = 1;
3583 SET_DECL_TEMPLATE_PARM_P (decl);
3585 parm = build_tree_list (defval, parm);
3586 return chainon (list, parm);
3589 /* The end of a template parameter list has been reached. Process the
3590 tree list into a parameter vector, converting each parameter into a more
3591 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3595 end_template_parm_list (tree parms)
3599 tree saved_parmlist = make_tree_vec (list_length (parms));
3601 current_template_parms
3602 = tree_cons (size_int (processing_template_decl),
3603 saved_parmlist, current_template_parms);
3605 for (parm = parms, nparms = 0; parm; parm = next, nparms++)
3607 next = TREE_CHAIN (parm);
3608 TREE_VEC_ELT (saved_parmlist, nparms) = parm;
3609 TREE_CHAIN (parm) = NULL_TREE;
3612 --processing_template_parmlist;
3614 return saved_parmlist;
3617 /* Create a new type almost identical to TYPE but which has the
3618 following differences:
3620 1/ T has a new TEMPLATE_PARM_INDEX that carries the new number of
3621 template sibling parameters of T.
3623 2/ T has a new canonical type that matches the new number
3626 3/ From now on, T is going to be what lookups referring to the
3627 name of TYPE will return. No lookup should return TYPE anymore.
3629 NUM_PARMS is the new number of sibling parms TYPE belongs to.
3631 This is a subroutine of fixup_template_parms. */
3634 fixup_template_type_parm_type (tree type, int num_parms)
3636 tree orig_idx = TEMPLATE_TYPE_PARM_INDEX (type), idx;
3638 /* This is the decl which name is inserted into the symbol table for
3639 the template parm type. So whenever we lookup the type name, this
3640 is the DECL we get. */
3643 /* Do not fix up the type twice. */
3644 if (orig_idx && TEMPLATE_PARM_NUM_SIBLINGS (orig_idx) != 0)
3647 t = copy_type (type);
3648 decl = TYPE_NAME (t);
3650 TYPE_MAIN_VARIANT (t) = t;
3651 TYPE_NEXT_VARIANT (t)= NULL_TREE;
3652 TYPE_POINTER_TO (t) = 0;
3653 TYPE_REFERENCE_TO (t) = 0;
3655 idx = build_template_parm_index (TEMPLATE_PARM_IDX (orig_idx),
3656 TEMPLATE_PARM_LEVEL (orig_idx),
3657 TEMPLATE_PARM_ORIG_LEVEL (orig_idx),
3660 TEMPLATE_PARM_DESCENDANTS (idx) = TEMPLATE_PARM_DESCENDANTS (orig_idx);
3661 TEMPLATE_PARM_PARAMETER_PACK (idx) = TEMPLATE_PARM_PARAMETER_PACK (orig_idx);
3662 TEMPLATE_TYPE_PARM_INDEX (t) = idx;
3664 TYPE_STUB_DECL (t) = decl;
3665 TEMPLATE_TYPE_DECL (t) = decl;
3666 if (TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM)
3667 TREE_TYPE (DECL_TEMPLATE_RESULT (decl)) = t;
3669 /* Update the type associated to the type name stored in the symbol
3670 table. Now, whenever the type name is looked up, the resulting
3671 type is properly fixed up. */
3672 TREE_TYPE (decl) = t;
3674 TYPE_CANONICAL (t) = canonical_type_parameter (t);
3679 /* Create and return a new TEMPLATE_PARM_INDEX that is almost
3680 identical to I, but that is fixed up as to:
3682 1/ carry the number of sibling parms (NUM_PARMS) of the template
3683 parm represented by I.
3685 2/ replace all references to template parm types declared before I
3686 (in the same template parm list as I) by references to template
3687 parm types contained in ARGS. ARGS should contain the list of
3688 template parms that have been fixed up so far, in a form suitable
3689 to be passed to tsubst.
3691 This is a subroutine of fixup_template_parms. */
3694 fixup_template_parm_index (tree i, tree args, int num_parms)
3696 tree index, decl, type;
3699 || TREE_CODE (i) != TEMPLATE_PARM_INDEX
3700 /* Do not fix up the index twice. */
3701 || (TEMPLATE_PARM_NUM_SIBLINGS (i) != 0))
3704 decl = TEMPLATE_PARM_DECL (i);
3705 type = TREE_TYPE (decl);
3707 index = build_template_parm_index (TEMPLATE_PARM_IDX (i),
3708 TEMPLATE_PARM_LEVEL (i),
3709 TEMPLATE_PARM_ORIG_LEVEL (i),
3713 TEMPLATE_PARM_DESCENDANTS (index) = TEMPLATE_PARM_DESCENDANTS (i);
3714 TEMPLATE_PARM_PARAMETER_PACK (index) = TEMPLATE_PARM_PARAMETER_PACK (i);
3716 type = tsubst (type, args, tf_none, NULL_TREE);
3718 TREE_TYPE (decl) = type;
3719 TREE_TYPE (index) = type;
3725 This is a subroutine of fixup_template_parms.
3727 It computes the canonical type of the type of the template
3728 parameter PARM_DESC and update all references to that type so that
3729 they use the newly computed canonical type. No access check is
3730 performed during the fixup. PARM_DESC is a TREE_LIST which
3731 TREE_VALUE is the template parameter and its TREE_PURPOSE is the
3732 default argument of the template parm if any. IDX is the index of
3733 the template parameter, starting at 0. NUM_PARMS is the number of
3734 template parameters in the set PARM_DESC belongs to. ARGLIST is a
3735 TREE_VEC containing the full set of template parameters in a form
3736 suitable to be passed to substs functions as their ARGS
3737 argument. This is what current_template_args returns for a given
3738 template. The innermost vector of args in ARGLIST is the set of
3739 template parms that have been fixed up so far. This function adds
3740 the fixed up parameter into that vector. */
3743 fixup_template_parm (tree parm_desc,
3748 tree parm = TREE_VALUE (parm_desc);
3749 tree fixedup_args = INNERMOST_TEMPLATE_ARGS (arglist);
3751 push_deferring_access_checks (dk_no_check);
3753 if (TREE_CODE (parm) == TYPE_DECL)
3755 /* PARM is a template type parameter. Fix up its type, add
3756 the fixed-up template parm to the vector of fixed-up
3757 template parms so far, and substitute the fixed-up
3758 template parms into the default argument of this
3761 fixup_template_type_parm_type (TREE_TYPE (parm), num_parms);
3762 TREE_TYPE (parm) = t;
3764 TREE_VEC_ELT (fixedup_args, idx) = template_parm_to_arg (parm_desc);
3766 else if (TREE_CODE (parm) == TEMPLATE_DECL)
3768 /* PARM is a template template parameter. This is going to
3770 tree tparms, targs, innermost_args, t;
3773 /* First, fix up the parms of the template template parm
3774 because the parms are involved in defining the new canonical
3775 type of the template template parm. */
3777 /* So we need to substitute the template parm types that have
3778 been fixed up so far into the template parms of this template
3779 template parm. E.g, consider this:
3781 template<class T, template<T u> class TT> class S;
3783 In this case we want to substitute T into the
3784 template parameters of TT.
3786 So let's walk the template parms of PARM here, and
3787 tsubst ARGLIST into into each of the template
3790 /* For this substitution we need to build the full set of
3791 template parameters and use that as arguments for the
3792 tsubsting function. */
3793 tparms = INNERMOST_TEMPLATE_PARMS (DECL_TEMPLATE_PARMS (parm));
3795 /* This will contain the innermost parms of PARM into which
3796 we have substituted so far. */
3797 innermost_args = make_tree_vec (TREE_VEC_LENGTH (tparms));
3798 targs = add_to_template_args (arglist, innermost_args);
3799 for (j = 0; j < TREE_VEC_LENGTH (tparms); ++j)
3803 parameter = TREE_VEC_ELT (tparms, j);
3805 /* INNERMOST_ARGS needs to have at least the same number
3806 of elements as the index PARAMETER, ortherwise
3807 tsubsting into PARAMETER will result in partially
3808 instantiating it, reducing its tempate parm
3809 level. Let's tactically fill INNERMOST_ARGS for that
3811 TREE_VEC_ELT (innermost_args, j) =
3812 template_parm_to_arg (parameter);
3814 fixup_template_parm (parameter, j,
3815 TREE_VEC_LENGTH (tparms),
3819 /* Now fix up the type of the template template parm. */
3821 t = fixup_template_type_parm_type (TREE_TYPE (parm), num_parms);
3822 TREE_TYPE (parm) = t;
3824 TREE_VEC_ELT (fixedup_args, idx) =
3825 template_parm_to_arg (parm_desc);
3827 else if (TREE_CODE (parm) == PARM_DECL)
3829 /* PARM is a non-type template parameter. We need to:
3831 * Fix up its TEMPLATE_PARM_INDEX to make it carry the
3832 proper number of sibling parameters.
3834 * Make lookups of the template parameter return a reference
3835 to the fixed-up index. No lookup should return references
3836 to the former index anymore.
3838 * Substitute the template parms that got fixed up so far
3840 * into the type of PARM. */
3842 tree index = DECL_INITIAL (parm);
3844 /* PUSHED_DECL is the decl added to the symbol table with
3845 the name of the parameter. E,g:
3847 template<class T, T u> //#0
3848 auto my_function(T t) -> decltype(u); //#1
3850 Here, when looking up u at //#1, we get the decl of u
3851 resulting from the declaration in #0. This is what
3852 PUSHED_DECL is. We need to replace the reference to the
3853 old TEMPLATE_PARM_INDEX carried by PUSHED_DECL by the
3854 fixed-up TEMPLATE_PARM_INDEX. */
3855 tree pushed_decl = TEMPLATE_PARM_DECL (index);
3857 /* Let's fix up the TEMPLATE_PARM_INDEX then. Note that we must
3858 fixup the type of PUSHED_DECL as well and luckily
3859 fixup_template_parm_index does it for us too. */
3860 tree fixed_up_index =
3861 fixup_template_parm_index (index, arglist, num_parms);
3863 DECL_INITIAL (pushed_decl) = DECL_INITIAL (parm) = fixed_up_index;
3865 /* Add this fixed up PARM to the template parms we've fixed
3866 up so far and use that to substitute the fixed-up
3867 template parms into the type of PARM. */
3868 TREE_VEC_ELT (fixedup_args, idx) =
3869 template_parm_to_arg (parm_desc);
3870 TREE_TYPE (parm) = tsubst (TREE_TYPE (parm), arglist,
3871 tf_none, NULL_TREE);
3874 TREE_PURPOSE (parm_desc) =
3875 tsubst_template_arg (TREE_PURPOSE (parm_desc),
3876 arglist, tf_none, parm);
3878 pop_deferring_access_checks ();
3881 /* Walk the current template parms and properly compute the canonical
3882 types of the dependent types created during
3883 cp_parser_template_parameter_list. */
3886 fixup_template_parms (void)
3893 parameter_vec = INNERMOST_TEMPLATE_PARMS (current_template_parms);
3894 if (parameter_vec == NULL_TREE)
3897 num_parms = TREE_VEC_LENGTH (parameter_vec);
3899 /* This vector contains the current innermost template parms that
3900 have been fixed up so far. The form of FIXEDUP_ARGS is suitable
3901 to be passed to tsubst* functions as their ARGS argument. */
3902 fixedup_args = make_tree_vec (num_parms);
3904 /* This vector contains the full set of template parms in a form
3905 suitable to be passed to substs functions as their ARGS
3907 arglist = current_template_args ();
3908 arglist = add_outermost_template_args (arglist, fixedup_args);
3910 /* Let's do the proper fixup now. */
3911 for (i = 0; i < num_parms; ++i)
3912 fixup_template_parm (TREE_VEC_ELT (parameter_vec, i),
3913 i, num_parms, arglist);
3916 /* end_template_decl is called after a template declaration is seen. */
3919 end_template_decl (void)
3921 reset_specialization ();
3923 if (! processing_template_decl)
3926 /* This matches the pushlevel in begin_template_parm_list. */
3929 --processing_template_decl;
3930 current_template_parms = TREE_CHAIN (current_template_parms);
3933 /* Takes a TREE_LIST representing a template parameter and convert it
3934 into an argument suitable to be passed to the type substitution
3935 functions. Note that If the TREE_LIST contains an error_mark
3936 node, the returned argument is error_mark_node. */
3939 template_parm_to_arg (tree t)
3943 || TREE_CODE (t) != TREE_LIST)
3946 if (error_operand_p (TREE_VALUE (t)))
3947 return error_mark_node;
3951 if (TREE_CODE (t) == TYPE_DECL
3952 || TREE_CODE (t) == TEMPLATE_DECL)
3956 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
3958 /* Turn this argument into a TYPE_ARGUMENT_PACK
3959 with a single element, which expands T. */
3960 tree vec = make_tree_vec (1);
3961 #ifdef ENABLE_CHECKING
3962 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3963 (vec, TREE_VEC_LENGTH (vec));
3965 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
3967 t = cxx_make_type (TYPE_ARGUMENT_PACK);
3968 SET_ARGUMENT_PACK_ARGS (t, vec);
3973 t = DECL_INITIAL (t);
3975 if (TEMPLATE_PARM_PARAMETER_PACK (t))
3977 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3978 with a single element, which expands T. */
3979 tree vec = make_tree_vec (1);
3980 tree type = TREE_TYPE (TEMPLATE_PARM_DECL (t));
3981 #ifdef ENABLE_CHECKING
3982 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3983 (vec, TREE_VEC_LENGTH (vec));
3985 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
3987 t = make_node (NONTYPE_ARGUMENT_PACK);
3988 SET_ARGUMENT_PACK_ARGS (t, vec);
3989 TREE_TYPE (t) = type;
3995 /* Within the declaration of a template, return all levels of template
3996 parameters that apply. The template parameters are represented as
3997 a TREE_VEC, in the form documented in cp-tree.h for template
4001 current_template_args (void)
4004 tree args = NULL_TREE;
4005 int length = TMPL_PARMS_DEPTH (current_template_parms);
4008 /* If there is only one level of template parameters, we do not
4009 create a TREE_VEC of TREE_VECs. Instead, we return a single
4010 TREE_VEC containing the arguments. */
4012 args = make_tree_vec (length);
4014 for (header = current_template_parms; header; header = TREE_CHAIN (header))
4016 tree a = copy_node (TREE_VALUE (header));
4019 TREE_TYPE (a) = NULL_TREE;
4020 for (i = TREE_VEC_LENGTH (a) - 1; i >= 0; --i)
4021 TREE_VEC_ELT (a, i) = template_parm_to_arg (TREE_VEC_ELT (a, i));
4023 #ifdef ENABLE_CHECKING
4024 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (a, TREE_VEC_LENGTH (a));
4028 TREE_VEC_ELT (args, --l) = a;
4033 if (length > 1 && TREE_VEC_ELT (args, 0) == NULL_TREE)
4034 /* This can happen for template parms of a template template
4037 template<template<class T, class U> class TT> struct S;
4039 Consider the level of the parms of TT; T and U both have
4040 level 2; TT has no template parm of level 1. So in this case
4041 the first element of full_template_args is NULL_TREE. If we
4042 leave it like this TMPL_ARG_DEPTH on args returns 1 instead
4043 of 2. This will make tsubst wrongly consider that T and U
4044 have level 1. Instead, let's create a dummy vector as the
4045 first element of full_template_args so that TMPL_ARG_DEPTH
4046 returns the correct depth for args. */
4047 TREE_VEC_ELT (args, 0) = make_tree_vec (1);
4051 /* Update the declared TYPE by doing any lookups which were thought to be
4052 dependent, but are not now that we know the SCOPE of the declarator. */
4055 maybe_update_decl_type (tree orig_type, tree scope)
4057 tree type = orig_type;
4059 if (type == NULL_TREE)
4062 if (TREE_CODE (orig_type) == TYPE_DECL)
4063 type = TREE_TYPE (type);
4065 if (scope && TYPE_P (scope) && dependent_type_p (scope)
4066 && dependent_type_p (type)
4067 /* Don't bother building up the args in this case. */
4068 && TREE_CODE (type) != TEMPLATE_TYPE_PARM)
4070 /* tsubst in the args corresponding to the template parameters,
4071 including auto if present. Most things will be unchanged, but
4072 make_typename_type and tsubst_qualified_id will resolve
4073 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4074 tree args = current_template_args ();
4075 tree auto_node = type_uses_auto (type);
4079 tree auto_vec = make_tree_vec (1);
4080 TREE_VEC_ELT (auto_vec, 0) = auto_node;
4081 args = add_to_template_args (args, auto_vec);
4083 pushed = push_scope (scope);
4084 type = tsubst (type, args, tf_warning_or_error, NULL_TREE);
4089 if (type == error_mark_node)
4092 if (TREE_CODE (orig_type) == TYPE_DECL)
4094 if (same_type_p (type, TREE_TYPE (orig_type)))
4097 type = TYPE_NAME (type);
4102 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4103 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
4104 a member template. Used by push_template_decl below. */
4107 build_template_decl (tree decl, tree parms, bool member_template_p)
4109 tree tmpl = build_lang_decl (TEMPLATE_DECL, DECL_NAME (decl), NULL_TREE);
4110 DECL_TEMPLATE_PARMS (tmpl) = parms;
4111 DECL_CONTEXT (tmpl) = DECL_CONTEXT (decl);
4112 DECL_MEMBER_TEMPLATE_P (tmpl) = member_template_p;
4117 struct template_parm_data
4119 /* The level of the template parameters we are currently
4123 /* The index of the specialization argument we are currently
4127 /* An array whose size is the number of template parameters. The
4128 elements are nonzero if the parameter has been used in any one
4129 of the arguments processed so far. */
4132 /* An array whose size is the number of template arguments. The
4133 elements are nonzero if the argument makes use of template
4134 parameters of this level. */
4135 int* arg_uses_template_parms;
4138 /* Subroutine of push_template_decl used to see if each template
4139 parameter in a partial specialization is used in the explicit
4140 argument list. If T is of the LEVEL given in DATA (which is
4141 treated as a template_parm_data*), then DATA->PARMS is marked
4145 mark_template_parm (tree t, void* data)
4149 struct template_parm_data* tpd = (struct template_parm_data*) data;
4151 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
4153 level = TEMPLATE_PARM_LEVEL (t);
4154 idx = TEMPLATE_PARM_IDX (t);
4158 level = TEMPLATE_TYPE_LEVEL (t);
4159 idx = TEMPLATE_TYPE_IDX (t);
4162 if (level == tpd->level)
4164 tpd->parms[idx] = 1;
4165 tpd->arg_uses_template_parms[tpd->current_arg] = 1;
4168 /* Return zero so that for_each_template_parm will continue the
4169 traversal of the tree; we want to mark *every* template parm. */
4173 /* Process the partial specialization DECL. */
4176 process_partial_specialization (tree decl)
4178 tree type = TREE_TYPE (decl);
4179 tree maintmpl = CLASSTYPE_TI_TEMPLATE (type);
4180 tree specargs = CLASSTYPE_TI_ARGS (type);
4181 tree inner_args = INNERMOST_TEMPLATE_ARGS (specargs);
4182 tree main_inner_parms = DECL_INNERMOST_TEMPLATE_PARMS (maintmpl);
4185 int nargs = TREE_VEC_LENGTH (inner_args);
4188 bool did_error_intro = false;
4189 struct template_parm_data tpd;
4190 struct template_parm_data tpd2;
4192 gcc_assert (current_template_parms);
4194 inner_parms = INNERMOST_TEMPLATE_PARMS (current_template_parms);
4195 ntparms = TREE_VEC_LENGTH (inner_parms);
4197 /* We check that each of the template parameters given in the
4198 partial specialization is used in the argument list to the
4199 specialization. For example:
4201 template <class T> struct S;
4202 template <class T> struct S<T*>;
4204 The second declaration is OK because `T*' uses the template
4205 parameter T, whereas
4207 template <class T> struct S<int>;
4209 is no good. Even trickier is:
4220 The S2<T> declaration is actually invalid; it is a
4221 full-specialization. Of course,
4224 struct S2<T (*)(U)>;
4226 or some such would have been OK. */
4227 tpd.level = TMPL_PARMS_DEPTH (current_template_parms);
4228 tpd.parms = XALLOCAVEC (int, ntparms);
4229 memset (tpd.parms, 0, sizeof (int) * ntparms);
4231 tpd.arg_uses_template_parms = XALLOCAVEC (int, nargs);
4232 memset (tpd.arg_uses_template_parms, 0, sizeof (int) * nargs);
4233 for (i = 0; i < nargs; ++i)
4235 tpd.current_arg = i;
4236 for_each_template_parm (TREE_VEC_ELT (inner_args, i),
4237 &mark_template_parm,
4240 /*include_nondeduced_p=*/false);
4242 for (i = 0; i < ntparms; ++i)
4243 if (tpd.parms[i] == 0)
4245 /* One of the template parms was not used in the
4247 if (!did_error_intro)
4249 error ("template parameters not used in partial specialization:");
4250 did_error_intro = true;
4253 error (" %qD", TREE_VALUE (TREE_VEC_ELT (inner_parms, i)));
4256 if (did_error_intro)
4257 return error_mark_node;
4259 /* [temp.class.spec]
4261 The argument list of the specialization shall not be identical to
4262 the implicit argument list of the primary template. */
4263 if (comp_template_args
4265 INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE
4267 error ("partial specialization %qT does not specialize any template arguments", type);
4269 /* [temp.class.spec]
4271 A partially specialized non-type argument expression shall not
4272 involve template parameters of the partial specialization except
4273 when the argument expression is a simple identifier.
4275 The type of a template parameter corresponding to a specialized
4276 non-type argument shall not be dependent on a parameter of the
4279 Also, we verify that pack expansions only occur at the
4280 end of the argument list. */
4281 gcc_assert (nargs == DECL_NTPARMS (maintmpl));
4283 for (i = 0; i < nargs; ++i)
4285 tree parm = TREE_VALUE (TREE_VEC_ELT (main_inner_parms, i));
4286 tree arg = TREE_VEC_ELT (inner_args, i);
4287 tree packed_args = NULL_TREE;
4290 if (ARGUMENT_PACK_P (arg))
4292 /* Extract the arguments from the argument pack. We'll be
4293 iterating over these in the following loop. */
4294 packed_args = ARGUMENT_PACK_ARGS (arg);
4295 len = TREE_VEC_LENGTH (packed_args);
4298 for (j = 0; j < len; j++)
4301 /* Get the Jth argument in the parameter pack. */
4302 arg = TREE_VEC_ELT (packed_args, j);
4304 if (PACK_EXPANSION_P (arg))
4306 /* Pack expansions must come at the end of the
4308 if ((packed_args && j < len - 1)
4309 || (!packed_args && i < nargs - 1))
4311 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
4312 error ("parameter pack argument %qE must be at the "
4313 "end of the template argument list", arg);
4315 error ("parameter pack argument %qT must be at the "
4316 "end of the template argument list", arg);
4320 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
4321 /* We only care about the pattern. */
4322 arg = PACK_EXPANSION_PATTERN (arg);
4324 if (/* These first two lines are the `non-type' bit. */
4326 && TREE_CODE (arg) != TEMPLATE_DECL
4327 /* This next line is the `argument expression is not just a
4328 simple identifier' condition and also the `specialized
4329 non-type argument' bit. */
4330 && TREE_CODE (arg) != TEMPLATE_PARM_INDEX)
4332 if ((!packed_args && tpd.arg_uses_template_parms[i])
4333 || (packed_args && uses_template_parms (arg)))
4334 error ("template argument %qE involves template parameter(s)",
4338 /* Look at the corresponding template parameter,
4339 marking which template parameters its type depends
4341 tree type = TREE_TYPE (parm);
4345 /* We haven't yet initialized TPD2. Do so now. */
4346 tpd2.arg_uses_template_parms = XALLOCAVEC (int, nargs);
4347 /* The number of parameters here is the number in the
4348 main template, which, as checked in the assertion
4350 tpd2.parms = XALLOCAVEC (int, nargs);
4352 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (maintmpl));
4355 /* Mark the template parameters. But this time, we're
4356 looking for the template parameters of the main
4357 template, not in the specialization. */
4358 tpd2.current_arg = i;
4359 tpd2.arg_uses_template_parms[i] = 0;
4360 memset (tpd2.parms, 0, sizeof (int) * nargs);
4361 for_each_template_parm (type,
4362 &mark_template_parm,
4365 /*include_nondeduced_p=*/false);
4367 if (tpd2.arg_uses_template_parms [i])
4369 /* The type depended on some template parameters.
4370 If they are fully specialized in the
4371 specialization, that's OK. */
4374 for (j = 0; j < nargs; ++j)
4375 if (tpd2.parms[j] != 0
4376 && tpd.arg_uses_template_parms [j])
4379 error_n (input_location, count,
4380 "type %qT of template argument %qE depends "
4381 "on a template parameter",
4382 "type %qT of template argument %qE depends "
4383 "on template parameters",
4392 /* We should only get here once. */
4393 gcc_assert (!COMPLETE_TYPE_P (type));
4395 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)
4396 = tree_cons (specargs, inner_parms,
4397 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl));
4398 TREE_TYPE (DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)) = type;
4400 for (inst = DECL_TEMPLATE_INSTANTIATIONS (maintmpl); inst;
4401 inst = TREE_CHAIN (inst))
4403 tree inst_type = TREE_VALUE (inst);
4404 if (COMPLETE_TYPE_P (inst_type)
4405 && CLASSTYPE_IMPLICIT_INSTANTIATION (inst_type))
4407 tree spec = most_specialized_class (inst_type, maintmpl, tf_none);
4408 if (spec && TREE_TYPE (spec) == type)
4409 permerror (input_location,
4410 "partial specialization of %qT after instantiation "
4411 "of %qT", type, inst_type);
4418 /* Check that a template declaration's use of default arguments and
4419 parameter packs is not invalid. Here, PARMS are the template
4420 parameters. IS_PRIMARY is nonzero if DECL is the thing declared by
4421 a primary template. IS_PARTIAL is nonzero if DECL is a partial
4425 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4426 declaration (but not a definition); 1 indicates a declaration, 2
4427 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4428 emitted for extraneous default arguments.
4430 Returns TRUE if there were no errors found, FALSE otherwise. */
4433 check_default_tmpl_args (tree decl, tree parms, int is_primary,
4434 int is_partial, int is_friend_decl)
4437 int last_level_to_check;
4439 bool no_errors = true;
4443 A default template-argument shall not be specified in a
4444 function template declaration or a function template definition, nor
4445 in the template-parameter-list of the definition of a member of a
4448 if (TREE_CODE (CP_DECL_CONTEXT (decl)) == FUNCTION_DECL)
4449 /* You can't have a function template declaration in a local
4450 scope, nor you can you define a member of a class template in a
4454 if (current_class_type
4455 && !TYPE_BEING_DEFINED (current_class_type)
4456 && DECL_LANG_SPECIFIC (decl)
4457 && DECL_DECLARES_FUNCTION_P (decl)
4458 /* If this is either a friend defined in the scope of the class
4459 or a member function. */
4460 && (DECL_FUNCTION_MEMBER_P (decl)
4461 ? same_type_p (DECL_CONTEXT (decl), current_class_type)
4462 : DECL_FRIEND_CONTEXT (decl)
4463 ? same_type_p (DECL_FRIEND_CONTEXT (decl), current_class_type)
4465 /* And, if it was a member function, it really was defined in
4466 the scope of the class. */
4467 && (!DECL_FUNCTION_MEMBER_P (decl)
4468 || DECL_INITIALIZED_IN_CLASS_P (decl)))
4469 /* We already checked these parameters when the template was
4470 declared, so there's no need to do it again now. This function
4471 was defined in class scope, but we're processing it's body now
4472 that the class is complete. */
4475 /* Core issue 226 (C++0x only): the following only applies to class
4477 if ((cxx_dialect == cxx98) || TREE_CODE (decl) != FUNCTION_DECL)
4481 If a template-parameter has a default template-argument, all
4482 subsequent template-parameters shall have a default
4483 template-argument supplied. */
4484 for (parm_level = parms; parm_level; parm_level = TREE_CHAIN (parm_level))
4486 tree inner_parms = TREE_VALUE (parm_level);
4487 int ntparms = TREE_VEC_LENGTH (inner_parms);
4488 int seen_def_arg_p = 0;
4491 for (i = 0; i < ntparms; ++i)
4493 tree parm = TREE_VEC_ELT (inner_parms, i);
4495 if (parm == error_mark_node)
4498 if (TREE_PURPOSE (parm))
4500 else if (seen_def_arg_p
4501 && !template_parameter_pack_p (TREE_VALUE (parm)))
4503 error ("no default argument for %qD", TREE_VALUE (parm));
4504 /* For better subsequent error-recovery, we indicate that
4505 there should have been a default argument. */
4506 TREE_PURPOSE (parm) = error_mark_node;
4512 /* Don't complain about an enclosing partial
4514 && parm_level == parms
4515 && TREE_CODE (decl) == TYPE_DECL
4517 && template_parameter_pack_p (TREE_VALUE (parm)))
4519 /* A primary class template can only have one
4520 parameter pack, at the end of the template
4523 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL)
4524 error ("parameter pack %qE must be at the end of the"
4525 " template parameter list", TREE_VALUE (parm));
4527 error ("parameter pack %qT must be at the end of the"
4528 " template parameter list",
4529 TREE_TYPE (TREE_VALUE (parm)));
4531 TREE_VALUE (TREE_VEC_ELT (inner_parms, i))
4539 if (((cxx_dialect == cxx98) && TREE_CODE (decl) != TYPE_DECL)
4543 /* For an ordinary class template, default template arguments are
4544 allowed at the innermost level, e.g.:
4545 template <class T = int>
4547 but, in a partial specialization, they're not allowed even
4548 there, as we have in [temp.class.spec]:
4550 The template parameter list of a specialization shall not
4551 contain default template argument values.
4553 So, for a partial specialization, or for a function template
4554 (in C++98/C++03), we look at all of them. */
4557 /* But, for a primary class template that is not a partial
4558 specialization we look at all template parameters except the
4560 parms = TREE_CHAIN (parms);
4562 /* Figure out what error message to issue. */
4563 if (is_friend_decl == 2)
4564 msg = G_("default template arguments may not be used in function template "
4565 "friend re-declaration");
4566 else if (is_friend_decl)
4567 msg = G_("default template arguments may not be used in function template "
4568 "friend declarations");
4569 else if (TREE_CODE (decl) == FUNCTION_DECL && (cxx_dialect == cxx98))
4570 msg = G_("default template arguments may not be used in function templates "
4571 "without -std=c++0x or -std=gnu++0x");
4572 else if (is_partial)
4573 msg = G_("default template arguments may not be used in "
4574 "partial specializations");
4576 msg = G_("default argument for template parameter for class enclosing %qD");
4578 if (current_class_type && TYPE_BEING_DEFINED (current_class_type))
4579 /* If we're inside a class definition, there's no need to
4580 examine the parameters to the class itself. On the one
4581 hand, they will be checked when the class is defined, and,
4582 on the other, default arguments are valid in things like:
4583 template <class T = double>
4584 struct S { template <class U> void f(U); };
4585 Here the default argument for `S' has no bearing on the
4586 declaration of `f'. */
4587 last_level_to_check = template_class_depth (current_class_type) + 1;
4589 /* Check everything. */
4590 last_level_to_check = 0;
4592 for (parm_level = parms;
4593 parm_level && TMPL_PARMS_DEPTH (parm_level) >= last_level_to_check;
4594 parm_level = TREE_CHAIN (parm_level))
4596 tree inner_parms = TREE_VALUE (parm_level);
4600 ntparms = TREE_VEC_LENGTH (inner_parms);
4601 for (i = 0; i < ntparms; ++i)
4603 if (TREE_VEC_ELT (inner_parms, i) == error_mark_node)
4606 if (TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)))
4611 if (is_friend_decl == 2)
4618 /* Clear out the default argument so that we are not
4620 TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)) = NULL_TREE;
4624 /* At this point, if we're still interested in issuing messages,
4625 they must apply to classes surrounding the object declared. */
4627 msg = G_("default argument for template parameter for class "
4634 /* Worker for push_template_decl_real, called via
4635 for_each_template_parm. DATA is really an int, indicating the
4636 level of the parameters we are interested in. If T is a template
4637 parameter of that level, return nonzero. */
4640 template_parm_this_level_p (tree t, void* data)
4642 int this_level = *(int *)data;
4645 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
4646 level = TEMPLATE_PARM_LEVEL (t);
4648 level = TEMPLATE_TYPE_LEVEL (t);
4649 return level == this_level;
4652 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4653 parameters given by current_template_args, or reuses a
4654 previously existing one, if appropriate. Returns the DECL, or an
4655 equivalent one, if it is replaced via a call to duplicate_decls.
4657 If IS_FRIEND is true, DECL is a friend declaration. */
4660 push_template_decl_real (tree decl, bool is_friend)
4668 int new_template_p = 0;
4669 /* True if the template is a member template, in the sense of
4671 bool member_template_p = false;
4673 if (decl == error_mark_node || !current_template_parms)
4674 return error_mark_node;
4676 /* See if this is a partial specialization. */
4677 is_partial = (DECL_IMPLICIT_TYPEDEF_P (decl)
4678 && TREE_CODE (TREE_TYPE (decl)) != ENUMERAL_TYPE
4679 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)));
4681 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_FRIEND_P (decl))
4685 /* For a friend, we want the context of the friend function, not
4686 the type of which it is a friend. */
4687 ctx = CP_DECL_CONTEXT (decl);
4688 else if (CP_DECL_CONTEXT (decl)
4689 && TREE_CODE (CP_DECL_CONTEXT (decl)) != NAMESPACE_DECL)
4690 /* In the case of a virtual function, we want the class in which
4692 ctx = CP_DECL_CONTEXT (decl);
4694 /* Otherwise, if we're currently defining some class, the DECL
4695 is assumed to be a member of the class. */
4696 ctx = current_scope ();
4698 if (ctx && TREE_CODE (ctx) == NAMESPACE_DECL)
4701 if (!DECL_CONTEXT (decl))
4702 DECL_CONTEXT (decl) = FROB_CONTEXT (current_namespace);
4704 /* See if this is a primary template. */
4705 if (is_friend && ctx)
4706 /* A friend template that specifies a class context, i.e.
4707 template <typename T> friend void A<T>::f();
4711 primary = template_parm_scope_p ();
4715 if (DECL_CLASS_SCOPE_P (decl))
4716 member_template_p = true;
4717 if (TREE_CODE (decl) == TYPE_DECL
4718 && ANON_AGGRNAME_P (DECL_NAME (decl)))
4720 error ("template class without a name");
4721 return error_mark_node;
4723 else if (TREE_CODE (decl) == FUNCTION_DECL)
4725 if (DECL_DESTRUCTOR_P (decl))
4729 A destructor shall not be a member template. */
4730 error ("destructor %qD declared as member template", decl);
4731 return error_mark_node;
4733 if (NEW_DELETE_OPNAME_P (DECL_NAME (decl))
4734 && (!prototype_p (TREE_TYPE (decl))
4735 || TYPE_ARG_TYPES (TREE_TYPE (decl)) == void_list_node
4736 || !TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (decl)))
4737 || (TREE_CHAIN (TYPE_ARG_TYPES ((TREE_TYPE (decl))))
4738 == void_list_node)))
4740 /* [basic.stc.dynamic.allocation]
4742 An allocation function can be a function
4743 template. ... Template allocation functions shall
4744 have two or more parameters. */
4745 error ("invalid template declaration of %qD", decl);
4746 return error_mark_node;
4749 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4750 && CLASS_TYPE_P (TREE_TYPE (decl)))
4754 error ("template declaration of %q#D", decl);
4755 return error_mark_node;
4759 /* Check to see that the rules regarding the use of default
4760 arguments are not being violated. */
4761 check_default_tmpl_args (decl, current_template_parms,
4762 primary, is_partial, /*is_friend_decl=*/0);
4764 /* Ensure that there are no parameter packs in the type of this
4765 declaration that have not been expanded. */
4766 if (TREE_CODE (decl) == FUNCTION_DECL)
4768 /* Check each of the arguments individually to see if there are
4769 any bare parameter packs. */
4770 tree type = TREE_TYPE (decl);
4771 tree arg = DECL_ARGUMENTS (decl);
4772 tree argtype = TYPE_ARG_TYPES (type);
4774 while (arg && argtype)
4776 if (!FUNCTION_PARAMETER_PACK_P (arg)
4777 && check_for_bare_parameter_packs (TREE_TYPE (arg)))
4779 /* This is a PARM_DECL that contains unexpanded parameter
4780 packs. We have already complained about this in the
4781 check_for_bare_parameter_packs call, so just replace
4782 these types with ERROR_MARK_NODE. */
4783 TREE_TYPE (arg) = error_mark_node;
4784 TREE_VALUE (argtype) = error_mark_node;
4787 arg = DECL_CHAIN (arg);
4788 argtype = TREE_CHAIN (argtype);
4791 /* Check for bare parameter packs in the return type and the
4792 exception specifiers. */
4793 if (check_for_bare_parameter_packs (TREE_TYPE (type)))
4794 /* Errors were already issued, set return type to int
4795 as the frontend doesn't expect error_mark_node as
4797 TREE_TYPE (type) = integer_type_node;
4798 if (check_for_bare_parameter_packs (TYPE_RAISES_EXCEPTIONS (type)))
4799 TYPE_RAISES_EXCEPTIONS (type) = NULL_TREE;
4801 else if (check_for_bare_parameter_packs (TREE_TYPE (decl)))
4803 TREE_TYPE (decl) = error_mark_node;
4804 return error_mark_node;
4808 return process_partial_specialization (decl);
4810 args = current_template_args ();
4813 || TREE_CODE (ctx) == FUNCTION_DECL
4814 || (CLASS_TYPE_P (ctx) && TYPE_BEING_DEFINED (ctx))
4815 || (is_friend && !DECL_TEMPLATE_INFO (decl)))
4817 if (DECL_LANG_SPECIFIC (decl)
4818 && DECL_TEMPLATE_INFO (decl)
4819 && DECL_TI_TEMPLATE (decl))
4820 tmpl = DECL_TI_TEMPLATE (decl);
4821 /* If DECL is a TYPE_DECL for a class-template, then there won't
4822 be DECL_LANG_SPECIFIC. The information equivalent to
4823 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4824 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4825 && TYPE_TEMPLATE_INFO (TREE_TYPE (decl))
4826 && TYPE_TI_TEMPLATE (TREE_TYPE (decl)))
4828 /* Since a template declaration already existed for this
4829 class-type, we must be redeclaring it here. Make sure
4830 that the redeclaration is valid. */
4831 redeclare_class_template (TREE_TYPE (decl),
4832 current_template_parms);
4833 /* We don't need to create a new TEMPLATE_DECL; just use the
4834 one we already had. */
4835 tmpl = TYPE_TI_TEMPLATE (TREE_TYPE (decl));
4839 tmpl = build_template_decl (decl, current_template_parms,
4843 if (DECL_LANG_SPECIFIC (decl)
4844 && DECL_TEMPLATE_SPECIALIZATION (decl))
4846 /* A specialization of a member template of a template
4848 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
4849 DECL_TEMPLATE_INFO (tmpl) = DECL_TEMPLATE_INFO (decl);
4850 DECL_TEMPLATE_INFO (decl) = NULL_TREE;
4856 tree a, t, current, parms;
4858 tree tinfo = get_template_info (decl);
4862 error ("template definition of non-template %q#D", decl);
4863 return error_mark_node;
4866 tmpl = TI_TEMPLATE (tinfo);
4868 if (DECL_FUNCTION_TEMPLATE_P (tmpl)
4869 && DECL_TEMPLATE_INFO (decl) && DECL_TI_ARGS (decl)
4870 && DECL_TEMPLATE_SPECIALIZATION (decl)
4871 && DECL_MEMBER_TEMPLATE_P (tmpl))
4875 /* The declaration is a specialization of a member
4876 template, declared outside the class. Therefore, the
4877 innermost template arguments will be NULL, so we
4878 replace them with the arguments determined by the
4879 earlier call to check_explicit_specialization. */
4880 args = DECL_TI_ARGS (decl);
4883 = build_template_decl (decl, current_template_parms,
4885 DECL_TEMPLATE_RESULT (new_tmpl) = decl;
4886 TREE_TYPE (new_tmpl) = TREE_TYPE (decl);
4887 DECL_TI_TEMPLATE (decl) = new_tmpl;
4888 SET_DECL_TEMPLATE_SPECIALIZATION (new_tmpl);
4889 DECL_TEMPLATE_INFO (new_tmpl)
4890 = build_template_info (tmpl, args);
4892 register_specialization (new_tmpl,
4893 most_general_template (tmpl),
4899 /* Make sure the template headers we got make sense. */
4901 parms = DECL_TEMPLATE_PARMS (tmpl);
4902 i = TMPL_PARMS_DEPTH (parms);
4903 if (TMPL_ARGS_DEPTH (args) != i)
4905 error ("expected %d levels of template parms for %q#D, got %d",
4906 i, decl, TMPL_ARGS_DEPTH (args));
4909 for (current = decl; i > 0; --i, parms = TREE_CHAIN (parms))
4911 a = TMPL_ARGS_LEVEL (args, i);
4912 t = INNERMOST_TEMPLATE_PARMS (parms);
4914 if (TREE_VEC_LENGTH (t) != TREE_VEC_LENGTH (a))
4916 if (current == decl)
4917 error ("got %d template parameters for %q#D",
4918 TREE_VEC_LENGTH (a), decl);
4920 error ("got %d template parameters for %q#T",
4921 TREE_VEC_LENGTH (a), current);
4922 error (" but %d required", TREE_VEC_LENGTH (t));
4923 return error_mark_node;
4926 if (current == decl)
4928 else if (current == NULL_TREE)
4929 /* Can happen in erroneous input. */
4932 current = (TYPE_P (current)
4933 ? TYPE_CONTEXT (current)
4934 : DECL_CONTEXT (current));
4937 /* Check that the parms are used in the appropriate qualifying scopes
4938 in the declarator. */
4939 if (!comp_template_args
4941 TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (tmpl)))))
4944 template arguments to %qD do not match original template %qD",
4945 decl, DECL_TEMPLATE_RESULT (tmpl));
4946 if (!uses_template_parms (TI_ARGS (tinfo)))
4947 inform (input_location, "use template<> for an explicit specialization");
4948 /* Avoid crash in import_export_decl. */
4949 DECL_INTERFACE_KNOWN (decl) = 1;
4950 return error_mark_node;
4954 DECL_TEMPLATE_RESULT (tmpl) = decl;
4955 TREE_TYPE (tmpl) = TREE_TYPE (decl);
4957 /* Push template declarations for global functions and types. Note
4958 that we do not try to push a global template friend declared in a
4959 template class; such a thing may well depend on the template
4960 parameters of the class. */
4961 if (new_template_p && !ctx
4962 && !(is_friend && template_class_depth (current_class_type) > 0))
4964 tmpl = pushdecl_namespace_level (tmpl, is_friend);
4965 if (tmpl == error_mark_node)
4966 return error_mark_node;
4968 /* Hide template friend classes that haven't been declared yet. */
4969 if (is_friend && TREE_CODE (decl) == TYPE_DECL)
4971 DECL_ANTICIPATED (tmpl) = 1;
4972 DECL_FRIEND_P (tmpl) = 1;
4978 tree parms = DECL_TEMPLATE_PARMS (tmpl);
4981 DECL_PRIMARY_TEMPLATE (tmpl) = tmpl;
4982 if (DECL_CONV_FN_P (tmpl))
4984 int depth = TMPL_PARMS_DEPTH (parms);
4986 /* It is a conversion operator. See if the type converted to
4987 depends on innermost template operands. */
4989 if (uses_template_parms_level (TREE_TYPE (TREE_TYPE (tmpl)),
4991 DECL_TEMPLATE_CONV_FN_P (tmpl) = 1;
4994 /* Give template template parms a DECL_CONTEXT of the template
4995 for which they are a parameter. */
4996 parms = INNERMOST_TEMPLATE_PARMS (parms);
4997 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
4999 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
5000 if (TREE_CODE (parm) == TEMPLATE_DECL)
5001 DECL_CONTEXT (parm) = tmpl;
5005 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5006 back to its most general template. If TMPL is a specialization,
5007 ARGS may only have the innermost set of arguments. Add the missing
5008 argument levels if necessary. */
5009 if (DECL_TEMPLATE_INFO (tmpl))
5010 args = add_outermost_template_args (DECL_TI_ARGS (tmpl), args);
5012 info = build_template_info (tmpl, args);
5014 if (DECL_IMPLICIT_TYPEDEF_P (decl))
5015 SET_TYPE_TEMPLATE_INFO (TREE_TYPE (tmpl), info);
5016 else if (DECL_LANG_SPECIFIC (decl))
5017 DECL_TEMPLATE_INFO (decl) = info;
5019 return DECL_TEMPLATE_RESULT (tmpl);
5023 push_template_decl (tree decl)
5025 return push_template_decl_real (decl, false);
5028 /* Called when a class template TYPE is redeclared with the indicated
5029 template PARMS, e.g.:
5031 template <class T> struct S;
5032 template <class T> struct S {}; */
5035 redeclare_class_template (tree type, tree parms)
5041 if (!TYPE_TEMPLATE_INFO (type))
5043 error ("%qT is not a template type", type);
5047 tmpl = TYPE_TI_TEMPLATE (type);
5048 if (!PRIMARY_TEMPLATE_P (tmpl))
5049 /* The type is nested in some template class. Nothing to worry
5050 about here; there are no new template parameters for the nested
5056 error ("template specifiers not specified in declaration of %qD",
5061 parms = INNERMOST_TEMPLATE_PARMS (parms);
5062 tmpl_parms = DECL_INNERMOST_TEMPLATE_PARMS (tmpl);
5064 if (TREE_VEC_LENGTH (parms) != TREE_VEC_LENGTH (tmpl_parms))
5066 error_n (input_location, TREE_VEC_LENGTH (parms),
5067 "redeclared with %d template parameter",
5068 "redeclared with %d template parameters",
5069 TREE_VEC_LENGTH (parms));
5070 inform_n (input_location, TREE_VEC_LENGTH (tmpl_parms),
5071 "previous declaration %q+D used %d template parameter",
5072 "previous declaration %q+D used %d template parameters",
5073 tmpl, TREE_VEC_LENGTH (tmpl_parms));
5077 for (i = 0; i < TREE_VEC_LENGTH (tmpl_parms); ++i)
5084 if (TREE_VEC_ELT (tmpl_parms, i) == error_mark_node
5085 || TREE_VEC_ELT (parms, i) == error_mark_node)
5088 tmpl_parm = TREE_VALUE (TREE_VEC_ELT (tmpl_parms, i));
5089 if (tmpl_parm == error_mark_node)
5092 parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
5093 tmpl_default = TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i));
5094 parm_default = TREE_PURPOSE (TREE_VEC_ELT (parms, i));
5096 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5098 if (TREE_CODE (tmpl_parm) != TREE_CODE (parm)
5099 || (TREE_CODE (tmpl_parm) != TYPE_DECL
5100 && !same_type_p (TREE_TYPE (tmpl_parm), TREE_TYPE (parm)))
5101 || (TREE_CODE (tmpl_parm) != PARM_DECL
5102 && (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (tmpl_parm))
5103 != TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm))))
5104 || (TREE_CODE (tmpl_parm) == PARM_DECL
5105 && (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (tmpl_parm))
5106 != TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))))
5108 error ("template parameter %q+#D", tmpl_parm);
5109 error ("redeclared here as %q#D", parm);
5113 if (tmpl_default != NULL_TREE && parm_default != NULL_TREE)
5115 /* We have in [temp.param]:
5117 A template-parameter may not be given default arguments
5118 by two different declarations in the same scope. */
5119 error_at (input_location, "redefinition of default argument for %q#D", parm);
5120 inform (DECL_SOURCE_LOCATION (tmpl_parm),
5121 "original definition appeared here");
5125 if (parm_default != NULL_TREE)
5126 /* Update the previous template parameters (which are the ones
5127 that will really count) with the new default value. */
5128 TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i)) = parm_default;
5129 else if (tmpl_default != NULL_TREE)
5130 /* Update the new parameters, too; they'll be used as the
5131 parameters for any members. */
5132 TREE_PURPOSE (TREE_VEC_ELT (parms, i)) = tmpl_default;
5138 /* Simplify EXPR if it is a non-dependent expression. Returns the
5139 (possibly simplified) expression. */
5142 fold_non_dependent_expr_sfinae (tree expr, tsubst_flags_t complain)
5144 if (expr == NULL_TREE)
5147 /* If we're in a template, but EXPR isn't value dependent, simplify
5148 it. We're supposed to treat:
5150 template <typename T> void f(T[1 + 1]);
5151 template <typename T> void f(T[2]);
5153 as two declarations of the same function, for example. */
5154 if (processing_template_decl
5155 && !type_dependent_expression_p (expr)
5156 && potential_constant_expression (expr)
5157 && !value_dependent_expression_p (expr))
5159 HOST_WIDE_INT saved_processing_template_decl;
5161 saved_processing_template_decl = processing_template_decl;
5162 processing_template_decl = 0;
5163 expr = tsubst_copy_and_build (expr,
5166 /*in_decl=*/NULL_TREE,
5167 /*function_p=*/false,
5168 /*integral_constant_expression_p=*/true);
5169 processing_template_decl = saved_processing_template_decl;
5175 fold_non_dependent_expr (tree expr)
5177 return fold_non_dependent_expr_sfinae (expr, tf_error);
5180 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5181 must be a function or a pointer-to-function type, as specified
5182 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5183 and check that the resulting function has external linkage. */
5186 convert_nontype_argument_function (tree type, tree expr)
5191 fn = instantiate_type (type, fns, tf_none);
5192 if (fn == error_mark_node)
5193 return error_mark_node;
5196 if (TREE_CODE (fn_no_ptr) == ADDR_EXPR)
5197 fn_no_ptr = TREE_OPERAND (fn_no_ptr, 0);
5198 if (TREE_CODE (fn_no_ptr) == BASELINK)
5199 fn_no_ptr = BASELINK_FUNCTIONS (fn_no_ptr);
5201 /* [temp.arg.nontype]/1
5203 A template-argument for a non-type, non-template template-parameter
5206 -- the address of an object or function with external linkage. */
5207 if (!DECL_EXTERNAL_LINKAGE_P (fn_no_ptr))
5209 error ("%qE is not a valid template argument for type %qT "
5210 "because function %qD has not external linkage",
5211 expr, type, fn_no_ptr);
5218 /* Subroutine of convert_nontype_argument.
5219 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5220 Emit an error otherwise. */
5223 check_valid_ptrmem_cst_expr (tree type, tree expr,
5224 tsubst_flags_t complain)
5227 if (expr && (null_ptr_cst_p (expr) || TREE_CODE (expr) == PTRMEM_CST))
5229 if (complain & tf_error)
5231 error ("%qE is not a valid template argument for type %qT",
5233 error ("it must be a pointer-to-member of the form %<&X::Y%>");
5238 /* Returns TRUE iff the address of OP is value-dependent.
5240 14.6.2.4 [temp.dep.temp]:
5241 A non-integral non-type template-argument is dependent if its type is
5242 dependent or it has either of the following forms
5245 and contains a nested-name-specifier which specifies a class-name that
5246 names a dependent type.
5248 We generalize this to just say that the address of a member of a
5249 dependent class is value-dependent; the above doesn't cover the
5250 address of a static data member named with an unqualified-id. */
5253 has_value_dependent_address (tree op)
5255 /* We could use get_inner_reference here, but there's no need;
5256 this is only relevant for template non-type arguments, which
5257 can only be expressed as &id-expression. */
5260 tree ctx = CP_DECL_CONTEXT (op);
5261 if (TYPE_P (ctx) && dependent_type_p (ctx))
5268 /* Attempt to convert the non-type template parameter EXPR to the
5269 indicated TYPE. If the conversion is successful, return the
5270 converted value. If the conversion is unsuccessful, return
5271 NULL_TREE if we issued an error message, or error_mark_node if we
5272 did not. We issue error messages for out-and-out bad template
5273 parameters, but not simply because the conversion failed, since we
5274 might be just trying to do argument deduction. Both TYPE and EXPR
5275 must be non-dependent.
5277 The conversion follows the special rules described in
5278 [temp.arg.nontype], and it is much more strict than an implicit
5281 This function is called twice for each template argument (see
5282 lookup_template_class for a more accurate description of this
5283 problem). This means that we need to handle expressions which
5284 are not valid in a C++ source, but can be created from the
5285 first call (for instance, casts to perform conversions). These
5286 hacks can go away after we fix the double coercion problem. */
5289 convert_nontype_argument (tree type, tree expr, tsubst_flags_t complain)
5293 /* Detect immediately string literals as invalid non-type argument.
5294 This special-case is not needed for correctness (we would easily
5295 catch this later), but only to provide better diagnostic for this
5296 common user mistake. As suggested by DR 100, we do not mention
5297 linkage issues in the diagnostic as this is not the point. */
5298 /* FIXME we're making this OK. */
5299 if (TREE_CODE (expr) == STRING_CST)
5301 if (complain & tf_error)
5302 error ("%qE is not a valid template argument for type %qT "
5303 "because string literals can never be used in this context",
5308 /* Add the ADDR_EXPR now for the benefit of
5309 value_dependent_expression_p. */
5310 if (TYPE_PTROBV_P (type)
5311 && TREE_CODE (TREE_TYPE (expr)) == ARRAY_TYPE)
5312 expr = decay_conversion (expr);
5314 /* If we are in a template, EXPR may be non-dependent, but still
5315 have a syntactic, rather than semantic, form. For example, EXPR
5316 might be a SCOPE_REF, rather than the VAR_DECL to which the
5317 SCOPE_REF refers. Preserving the qualifying scope is necessary
5318 so that access checking can be performed when the template is
5319 instantiated -- but here we need the resolved form so that we can
5320 convert the argument. */
5321 if (TYPE_REF_OBJ_P (type)
5322 && has_value_dependent_address (expr))
5323 /* If we want the address and it's value-dependent, don't fold. */;
5324 else if (!type_unknown_p (expr))
5325 expr = fold_non_dependent_expr_sfinae (expr, complain);
5326 if (error_operand_p (expr))
5327 return error_mark_node;
5328 expr_type = TREE_TYPE (expr);
5329 if (TREE_CODE (type) == REFERENCE_TYPE)
5330 expr = mark_lvalue_use (expr);
5332 expr = mark_rvalue_use (expr);
5334 /* HACK: Due to double coercion, we can get a
5335 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5336 which is the tree that we built on the first call (see
5337 below when coercing to reference to object or to reference to
5338 function). We just strip everything and get to the arg.
5339 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5341 if (TREE_CODE (expr) == NOP_EXPR)
5343 if (TYPE_REF_OBJ_P (type) || TYPE_REFFN_P (type))
5345 /* ??? Maybe we could use convert_from_reference here, but we
5346 would need to relax its constraints because the NOP_EXPR
5347 could actually change the type to something more cv-qualified,
5348 and this is not folded by convert_from_reference. */
5349 tree addr = TREE_OPERAND (expr, 0);
5350 gcc_assert (TREE_CODE (expr_type) == REFERENCE_TYPE);
5351 gcc_assert (TREE_CODE (addr) == ADDR_EXPR);
5352 gcc_assert (TREE_CODE (TREE_TYPE (addr)) == POINTER_TYPE);
5353 gcc_assert (same_type_ignoring_top_level_qualifiers_p
5354 (TREE_TYPE (expr_type),
5355 TREE_TYPE (TREE_TYPE (addr))));
5357 expr = TREE_OPERAND (addr, 0);
5358 expr_type = TREE_TYPE (expr);
5361 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5362 parameter is a pointer to object, through decay and
5363 qualification conversion. Let's strip everything. */
5364 else if (TYPE_PTROBV_P (type))
5367 gcc_assert (TREE_CODE (expr) == ADDR_EXPR);
5368 gcc_assert (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE);
5369 /* Skip the ADDR_EXPR only if it is part of the decay for
5370 an array. Otherwise, it is part of the original argument
5371 in the source code. */
5372 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == ARRAY_TYPE)
5373 expr = TREE_OPERAND (expr, 0);
5374 expr_type = TREE_TYPE (expr);
5378 /* [temp.arg.nontype]/5, bullet 1
5380 For a non-type template-parameter of integral or enumeration type,
5381 integral promotions (_conv.prom_) and integral conversions
5382 (_conv.integral_) are applied. */
5383 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
5385 tree t = build_integral_nontype_arg_conv (type, expr, complain);
5386 t = maybe_constant_value (t);
5387 if (t != error_mark_node)
5390 if (!same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (expr)))
5391 return error_mark_node;
5393 /* Notice that there are constant expressions like '4 % 0' which
5394 do not fold into integer constants. */
5395 if (TREE_CODE (expr) != INTEGER_CST)
5397 if (complain & tf_error)
5399 int errs = errorcount, warns = warningcount;
5400 expr = cxx_constant_value (expr);
5401 if (errorcount > errs || warningcount > warns)
5402 inform (EXPR_LOC_OR_HERE (expr),
5403 "in template argument for type %qT ", type);
5404 if (expr == error_mark_node)
5406 /* else cxx_constant_value complained but gave us
5407 a real constant, so go ahead. */
5408 gcc_assert (TREE_CODE (expr) == INTEGER_CST);
5414 /* [temp.arg.nontype]/5, bullet 2
5416 For a non-type template-parameter of type pointer to object,
5417 qualification conversions (_conv.qual_) and the array-to-pointer
5418 conversion (_conv.array_) are applied. */
5419 else if (TYPE_PTROBV_P (type))
5421 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5423 A template-argument for a non-type, non-template template-parameter
5424 shall be one of: [...]
5426 -- the name of a non-type template-parameter;
5427 -- the address of an object or function with external linkage, [...]
5428 expressed as "& id-expression" where the & is optional if the name
5429 refers to a function or array, or if the corresponding
5430 template-parameter is a reference.
5432 Here, we do not care about functions, as they are invalid anyway
5433 for a parameter of type pointer-to-object. */
5435 if (DECL_P (expr) && DECL_TEMPLATE_PARM_P (expr))
5436 /* Non-type template parameters are OK. */
5438 else if (TREE_CODE (expr) != ADDR_EXPR
5439 && TREE_CODE (expr_type) != ARRAY_TYPE)
5441 if (TREE_CODE (expr) == VAR_DECL)
5443 error ("%qD is not a valid template argument "
5444 "because %qD is a variable, not the address of "
5449 /* Other values, like integer constants, might be valid
5450 non-type arguments of some other type. */
5451 return error_mark_node;
5457 decl = ((TREE_CODE (expr) == ADDR_EXPR)
5458 ? TREE_OPERAND (expr, 0) : expr);
5459 if (TREE_CODE (decl) != VAR_DECL)
5461 error ("%qE is not a valid template argument of type %qT "
5462 "because %qE is not a variable",
5466 else if (!DECL_EXTERNAL_LINKAGE_P (decl))
5468 error ("%qE is not a valid template argument of type %qT "
5469 "because %qD does not have external linkage",
5475 expr = decay_conversion (expr);
5476 if (expr == error_mark_node)
5477 return error_mark_node;
5479 expr = perform_qualification_conversions (type, expr);
5480 if (expr == error_mark_node)
5481 return error_mark_node;
5483 /* [temp.arg.nontype]/5, bullet 3
5485 For a non-type template-parameter of type reference to object, no
5486 conversions apply. The type referred to by the reference may be more
5487 cv-qualified than the (otherwise identical) type of the
5488 template-argument. The template-parameter is bound directly to the
5489 template-argument, which must be an lvalue. */
5490 else if (TYPE_REF_OBJ_P (type))
5492 if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type),
5494 return error_mark_node;
5496 if (!at_least_as_qualified_p (TREE_TYPE (type), expr_type))
5498 error ("%qE is not a valid template argument for type %qT "
5499 "because of conflicts in cv-qualification", expr, type);
5503 if (!real_lvalue_p (expr))
5505 error ("%qE is not a valid template argument for type %qT "
5506 "because it is not an lvalue", expr, type);
5510 /* [temp.arg.nontype]/1
5512 A template-argument for a non-type, non-template template-parameter
5513 shall be one of: [...]
5515 -- the address of an object or function with external linkage. */
5516 if (TREE_CODE (expr) == INDIRECT_REF
5517 && TYPE_REF_OBJ_P (TREE_TYPE (TREE_OPERAND (expr, 0))))
5519 expr = TREE_OPERAND (expr, 0);
5522 error ("%q#D is not a valid template argument for type %qT "
5523 "because a reference variable does not have a constant "
5524 "address", expr, type);
5531 error ("%qE is not a valid template argument for type %qT "
5532 "because it is not an object with external linkage",
5537 if (!DECL_EXTERNAL_LINKAGE_P (expr))
5539 error ("%qE is not a valid template argument for type %qT "
5540 "because object %qD has not external linkage",
5545 expr = build_nop (type, build_address (expr));
5547 /* [temp.arg.nontype]/5, bullet 4
5549 For a non-type template-parameter of type pointer to function, only
5550 the function-to-pointer conversion (_conv.func_) is applied. If the
5551 template-argument represents a set of overloaded functions (or a
5552 pointer to such), the matching function is selected from the set
5554 else if (TYPE_PTRFN_P (type))
5556 /* If the argument is a template-id, we might not have enough
5557 context information to decay the pointer. */
5558 if (!type_unknown_p (expr_type))
5560 expr = decay_conversion (expr);
5561 if (expr == error_mark_node)
5562 return error_mark_node;
5565 expr = convert_nontype_argument_function (type, expr);
5566 if (!expr || expr == error_mark_node)
5569 if (TREE_CODE (expr) != ADDR_EXPR)
5571 error ("%qE is not a valid template argument for type %qT", expr, type);
5572 error ("it must be the address of a function with external linkage");
5576 /* [temp.arg.nontype]/5, bullet 5
5578 For a non-type template-parameter of type reference to function, no
5579 conversions apply. If the template-argument represents a set of
5580 overloaded functions, the matching function is selected from the set
5582 else if (TYPE_REFFN_P (type))
5584 if (TREE_CODE (expr) == ADDR_EXPR)
5586 error ("%qE is not a valid template argument for type %qT "
5587 "because it is a pointer", expr, type);
5588 inform (input_location, "try using %qE instead", TREE_OPERAND (expr, 0));
5592 expr = convert_nontype_argument_function (TREE_TYPE (type), expr);
5593 if (!expr || expr == error_mark_node)
5596 expr = build_nop (type, build_address (expr));
5598 /* [temp.arg.nontype]/5, bullet 6
5600 For a non-type template-parameter of type pointer to member function,
5601 no conversions apply. If the template-argument represents a set of
5602 overloaded member functions, the matching member function is selected
5603 from the set (_over.over_). */
5604 else if (TYPE_PTRMEMFUNC_P (type))
5606 expr = instantiate_type (type, expr, tf_none);
5607 if (expr == error_mark_node)
5608 return error_mark_node;
5610 /* [temp.arg.nontype] bullet 1 says the pointer to member
5611 expression must be a pointer-to-member constant. */
5612 if (!check_valid_ptrmem_cst_expr (type, expr, complain))
5613 return error_mark_node;
5615 /* There is no way to disable standard conversions in
5616 resolve_address_of_overloaded_function (called by
5617 instantiate_type). It is possible that the call succeeded by
5618 converting &B::I to &D::I (where B is a base of D), so we need
5619 to reject this conversion here.
5621 Actually, even if there was a way to disable standard conversions,
5622 it would still be better to reject them here so that we can
5623 provide a superior diagnostic. */
5624 if (!same_type_p (TREE_TYPE (expr), type))
5626 error ("%qE is not a valid template argument for type %qT "
5627 "because it is of type %qT", expr, type,
5629 /* If we are just one standard conversion off, explain. */
5630 if (can_convert (type, TREE_TYPE (expr)))
5631 inform (input_location,
5632 "standard conversions are not allowed in this context");
5636 /* [temp.arg.nontype]/5, bullet 7
5638 For a non-type template-parameter of type pointer to data member,
5639 qualification conversions (_conv.qual_) are applied. */
5640 else if (TYPE_PTRMEM_P (type))
5642 /* [temp.arg.nontype] bullet 1 says the pointer to member
5643 expression must be a pointer-to-member constant. */
5644 if (!check_valid_ptrmem_cst_expr (type, expr, complain))
5645 return error_mark_node;
5647 expr = perform_qualification_conversions (type, expr);
5648 if (expr == error_mark_node)
5651 /* A template non-type parameter must be one of the above. */
5655 /* Sanity check: did we actually convert the argument to the
5657 gcc_assert (same_type_ignoring_top_level_qualifiers_p
5658 (type, TREE_TYPE (expr)));
5662 /* Subroutine of coerce_template_template_parms, which returns 1 if
5663 PARM_PARM and ARG_PARM match using the rule for the template
5664 parameters of template template parameters. Both PARM and ARG are
5665 template parameters; the rest of the arguments are the same as for
5666 coerce_template_template_parms.
5669 coerce_template_template_parm (tree parm,
5671 tsubst_flags_t complain,
5675 if (arg == NULL_TREE || arg == error_mark_node
5676 || parm == NULL_TREE || parm == error_mark_node)
5679 if (TREE_CODE (arg) != TREE_CODE (parm))
5682 switch (TREE_CODE (parm))
5685 /* We encounter instantiations of templates like
5686 template <template <template <class> class> class TT>
5689 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
5690 tree argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
5692 if (!coerce_template_template_parms
5693 (parmparm, argparm, complain, in_decl, outer_args))
5699 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (arg))
5700 && !TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
5701 /* Argument is a parameter pack but parameter is not. */
5706 /* The tsubst call is used to handle cases such as
5708 template <int> class C {};
5709 template <class T, template <T> class TT> class D {};
5712 i.e. the parameter list of TT depends on earlier parameters. */
5713 if (!uses_template_parms (TREE_TYPE (arg))
5715 (tsubst (TREE_TYPE (parm), outer_args, complain, in_decl),
5719 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (arg))
5720 && !TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
5721 /* Argument is a parameter pack but parameter is not. */
5734 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
5735 template template parameters. Both PARM_PARMS and ARG_PARMS are
5736 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
5739 Consider the example:
5740 template <class T> class A;
5741 template<template <class U> class TT> class B;
5743 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
5744 the parameters to A, and OUTER_ARGS contains A. */
5747 coerce_template_template_parms (tree parm_parms,
5749 tsubst_flags_t complain,
5753 int nparms, nargs, i;
5757 gcc_assert (TREE_CODE (parm_parms) == TREE_VEC);
5758 gcc_assert (TREE_CODE (arg_parms) == TREE_VEC);
5760 nparms = TREE_VEC_LENGTH (parm_parms);
5761 nargs = TREE_VEC_LENGTH (arg_parms);
5763 /* Determine whether we have a parameter pack at the end of the
5764 template template parameter's template parameter list. */
5765 if (TREE_VEC_ELT (parm_parms, nparms - 1) != error_mark_node)
5767 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, nparms - 1));
5769 if (parm == error_mark_node)
5772 switch (TREE_CODE (parm))
5776 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
5781 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
5791 && !(variadic_p && nargs >= nparms - 1))
5794 /* Check all of the template parameters except the parameter pack at
5795 the end (if any). */
5796 for (i = 0; i < nparms - variadic_p; ++i)
5798 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node
5799 || TREE_VEC_ELT (arg_parms, i) == error_mark_node)
5802 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
5803 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
5805 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
5813 /* Check each of the template parameters in the template
5814 argument against the template parameter pack at the end of
5815 the template template parameter. */
5816 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node)
5819 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
5821 for (; i < nargs; ++i)
5823 if (TREE_VEC_ELT (arg_parms, i) == error_mark_node)
5826 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
5828 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
5837 /* Verifies that the deduced template arguments (in TARGS) for the
5838 template template parameters (in TPARMS) represent valid bindings,
5839 by comparing the template parameter list of each template argument
5840 to the template parameter list of its corresponding template
5841 template parameter, in accordance with DR150. This
5842 routine can only be called after all template arguments have been
5843 deduced. It will return TRUE if all of the template template
5844 parameter bindings are okay, FALSE otherwise. */
5846 template_template_parm_bindings_ok_p (tree tparms, tree targs)
5848 int i, ntparms = TREE_VEC_LENGTH (tparms);
5851 /* We're dealing with template parms in this process. */
5852 ++processing_template_decl;
5854 targs = INNERMOST_TEMPLATE_ARGS (targs);
5856 for (i = 0; i < ntparms; ++i)
5858 tree tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
5859 tree targ = TREE_VEC_ELT (targs, i);
5861 if (TREE_CODE (tparm) == TEMPLATE_DECL && targ)
5863 tree packed_args = NULL_TREE;
5866 if (ARGUMENT_PACK_P (targ))
5868 /* Look inside the argument pack. */
5869 packed_args = ARGUMENT_PACK_ARGS (targ);
5870 len = TREE_VEC_LENGTH (packed_args);
5873 for (idx = 0; idx < len; ++idx)
5875 tree targ_parms = NULL_TREE;
5878 /* Extract the next argument from the argument
5880 targ = TREE_VEC_ELT (packed_args, idx);
5882 if (PACK_EXPANSION_P (targ))
5883 /* Look at the pattern of the pack expansion. */
5884 targ = PACK_EXPANSION_PATTERN (targ);
5886 /* Extract the template parameters from the template
5888 if (TREE_CODE (targ) == TEMPLATE_DECL)
5889 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (targ);
5890 else if (TREE_CODE (targ) == TEMPLATE_TEMPLATE_PARM)
5891 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (TYPE_NAME (targ));
5893 /* Verify that we can coerce the template template
5894 parameters from the template argument to the template
5895 parameter. This requires an exact match. */
5897 && !coerce_template_template_parms
5898 (DECL_INNERMOST_TEMPLATE_PARMS (tparm),
5913 --processing_template_decl;
5917 /* Convert the indicated template ARG as necessary to match the
5918 indicated template PARM. Returns the converted ARG, or
5919 error_mark_node if the conversion was unsuccessful. Error and
5920 warning messages are issued under control of COMPLAIN. This
5921 conversion is for the Ith parameter in the parameter list. ARGS is
5922 the full set of template arguments deduced so far. */
5925 convert_template_argument (tree parm,
5928 tsubst_flags_t complain,
5934 int is_type, requires_type, is_tmpl_type, requires_tmpl_type;
5936 if (TREE_CODE (arg) == TREE_LIST
5937 && TREE_CODE (TREE_VALUE (arg)) == OFFSET_REF)
5939 /* The template argument was the name of some
5940 member function. That's usually
5941 invalid, but static members are OK. In any
5942 case, grab the underlying fields/functions
5943 and issue an error later if required. */
5944 orig_arg = TREE_VALUE (arg);
5945 TREE_TYPE (arg) = unknown_type_node;
5950 requires_tmpl_type = TREE_CODE (parm) == TEMPLATE_DECL;
5951 requires_type = (TREE_CODE (parm) == TYPE_DECL
5952 || requires_tmpl_type);
5954 /* When determining whether an argument pack expansion is a template,
5955 look at the pattern. */
5956 if (TREE_CODE (arg) == TYPE_PACK_EXPANSION)
5957 arg = PACK_EXPANSION_PATTERN (arg);
5959 /* Deal with an injected-class-name used as a template template arg. */
5960 if (requires_tmpl_type && CLASS_TYPE_P (arg))
5962 tree t = maybe_get_template_decl_from_type_decl (TYPE_NAME (arg));
5963 if (TREE_CODE (t) == TEMPLATE_DECL)
5965 if (complain & tf_warning_or_error)
5966 pedwarn (input_location, OPT_pedantic, "injected-class-name %qD"
5967 " used as template template argument", TYPE_NAME (arg));
5968 else if (flag_pedantic_errors)
5976 ((TREE_CODE (arg) == TEMPLATE_DECL
5977 && TREE_CODE (DECL_TEMPLATE_RESULT (arg)) == TYPE_DECL)
5978 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
5979 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE);
5982 && (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
5983 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE))
5984 arg = TYPE_STUB_DECL (arg);
5986 is_type = TYPE_P (arg) || is_tmpl_type;
5988 if (requires_type && ! is_type && TREE_CODE (arg) == SCOPE_REF
5989 && TREE_CODE (TREE_OPERAND (arg, 0)) == TEMPLATE_TYPE_PARM)
5991 permerror (input_location, "to refer to a type member of a template parameter, "
5992 "use %<typename %E%>", orig_arg);
5994 orig_arg = make_typename_type (TREE_OPERAND (arg, 0),
5995 TREE_OPERAND (arg, 1),
5997 complain & tf_error);
6001 if (is_type != requires_type)
6005 if (complain & tf_error)
6007 error ("type/value mismatch at argument %d in template "
6008 "parameter list for %qD",
6011 error (" expected a constant of type %qT, got %qT",
6013 (DECL_P (arg) ? DECL_NAME (arg) : orig_arg));
6014 else if (requires_tmpl_type)
6015 error (" expected a class template, got %qE", orig_arg);
6017 error (" expected a type, got %qE", orig_arg);
6020 return error_mark_node;
6022 if (is_tmpl_type ^ requires_tmpl_type)
6024 if (in_decl && (complain & tf_error))
6026 error ("type/value mismatch at argument %d in template "
6027 "parameter list for %qD",
6030 error (" expected a type, got %qT", DECL_NAME (arg));
6032 error (" expected a class template, got %qT", orig_arg);
6034 return error_mark_node;
6039 if (requires_tmpl_type)
6041 if (TREE_CODE (TREE_TYPE (arg)) == UNBOUND_CLASS_TEMPLATE)
6042 /* The number of argument required is not known yet.
6043 Just accept it for now. */
6044 val = TREE_TYPE (arg);
6047 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
6050 argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
6052 if (coerce_template_template_parms (parmparm, argparm,
6058 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6060 if (val != error_mark_node)
6062 if (DECL_TEMPLATE_TEMPLATE_PARM_P (val))
6063 val = TREE_TYPE (val);
6064 if (TREE_CODE (orig_arg) == TYPE_PACK_EXPANSION)
6065 val = make_pack_expansion (val);
6070 if (in_decl && (complain & tf_error))
6072 error ("type/value mismatch at argument %d in "
6073 "template parameter list for %qD",
6075 error (" expected a template of type %qD, got %qT",
6079 val = error_mark_node;
6085 /* We only form one instance of each template specialization.
6086 Therefore, if we use a non-canonical variant (i.e., a
6087 typedef), any future messages referring to the type will use
6088 the typedef, which is confusing if those future uses do not
6089 themselves also use the typedef. */
6091 val = strip_typedefs (val);
6095 tree t = tsubst (TREE_TYPE (parm), args, complain, in_decl);
6097 if (invalid_nontype_parm_type_p (t, complain))
6098 return error_mark_node;
6100 if (template_parameter_pack_p (parm) && ARGUMENT_PACK_P (orig_arg))
6102 if (same_type_p (t, TREE_TYPE (orig_arg)))
6106 /* Not sure if this is reachable, but it doesn't hurt
6108 error ("type mismatch in nontype parameter pack");
6109 val = error_mark_node;
6112 else if (!uses_template_parms (orig_arg) && !uses_template_parms (t))
6113 /* We used to call digest_init here. However, digest_init
6114 will report errors, which we don't want when complain
6115 is zero. More importantly, digest_init will try too
6116 hard to convert things: for example, `0' should not be
6117 converted to pointer type at this point according to
6118 the standard. Accepting this is not merely an
6119 extension, since deciding whether or not these
6120 conversions can occur is part of determining which
6121 function template to call, or whether a given explicit
6122 argument specification is valid. */
6123 val = convert_nontype_argument (t, orig_arg, complain);
6127 if (val == NULL_TREE)
6128 val = error_mark_node;
6129 else if (val == error_mark_node && (complain & tf_error))
6130 error ("could not convert template argument %qE to %qT", orig_arg, t);
6132 if (TREE_CODE (val) == SCOPE_REF)
6134 /* Strip typedefs from the SCOPE_REF. */
6135 tree type = strip_typedefs (TREE_TYPE (val));
6136 tree scope = strip_typedefs (TREE_OPERAND (val, 0));
6137 val = build_qualified_name (type, scope, TREE_OPERAND (val, 1),
6138 QUALIFIED_NAME_IS_TEMPLATE (val));
6145 /* Coerces the remaining template arguments in INNER_ARGS (from
6146 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6147 Returns the coerced argument pack. PARM_IDX is the position of this
6148 parameter in the template parameter list. ARGS is the original
6149 template argument list. */
6151 coerce_template_parameter_pack (tree parms,
6159 tsubst_flags_t complain)
6161 tree parm = TREE_VEC_ELT (parms, parm_idx);
6162 int nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
6165 tree packed_types = NULL_TREE;
6167 if (arg_idx > nargs)
6170 packed_args = make_tree_vec (nargs - arg_idx);
6172 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL
6173 && uses_parameter_packs (TREE_TYPE (TREE_VALUE (parm))))
6175 /* When the template parameter is a non-type template
6176 parameter pack whose type uses parameter packs, we need
6177 to look at each of the template arguments
6178 separately. Build a vector of the types for these
6179 non-type template parameters in PACKED_TYPES. */
6181 = make_pack_expansion (TREE_TYPE (TREE_VALUE (parm)));
6182 packed_types = tsubst_pack_expansion (expansion, args,
6185 if (packed_types == error_mark_node)
6186 return error_mark_node;
6188 /* Check that we have the right number of arguments. */
6190 && !PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx))
6191 && nargs - arg_idx != TREE_VEC_LENGTH (packed_types))
6194 = TREE_VEC_LENGTH (parms) - 1 + TREE_VEC_LENGTH (packed_types);
6195 error ("wrong number of template arguments (%d, should be %d)",
6196 nargs, needed_parms);
6197 return error_mark_node;
6200 /* If we aren't able to check the actual arguments now
6201 (because they haven't been expanded yet), we can at least
6202 verify that all of the types used for the non-type
6203 template parameter pack are, in fact, valid for non-type
6204 template parameters. */
6206 && PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx)))
6208 int j, len = TREE_VEC_LENGTH (packed_types);
6209 for (j = 0; j < len; ++j)
6211 tree t = TREE_VEC_ELT (packed_types, j);
6212 if (invalid_nontype_parm_type_p (t, complain))
6213 return error_mark_node;
6218 /* Convert the remaining arguments, which will be a part of the
6219 parameter pack "parm". */
6220 for (; arg_idx < nargs; ++arg_idx)
6222 tree arg = TREE_VEC_ELT (inner_args, arg_idx);
6223 tree actual_parm = TREE_VALUE (parm);
6225 if (packed_types && !PACK_EXPANSION_P (arg))
6227 /* When we have a vector of types (corresponding to the
6228 non-type template parameter pack that uses parameter
6229 packs in its type, as mention above), and the
6230 argument is not an expansion (which expands to a
6231 currently unknown number of arguments), clone the
6232 parm and give it the next type in PACKED_TYPES. */
6233 actual_parm = copy_node (actual_parm);
6234 TREE_TYPE (actual_parm) =
6235 TREE_VEC_ELT (packed_types, arg_idx - parm_idx);
6238 if (arg != error_mark_node)
6239 arg = convert_template_argument (actual_parm,
6240 arg, new_args, complain, parm_idx,
6242 if (arg == error_mark_node)
6244 TREE_VEC_ELT (packed_args, arg_idx - parm_idx) = arg;
6247 if (TREE_CODE (TREE_VALUE (parm)) == TYPE_DECL
6248 || TREE_CODE (TREE_VALUE (parm)) == TEMPLATE_DECL)
6249 argument_pack = cxx_make_type (TYPE_ARGUMENT_PACK);
6252 argument_pack = make_node (NONTYPE_ARGUMENT_PACK);
6253 TREE_TYPE (argument_pack)
6254 = tsubst (TREE_TYPE (TREE_VALUE (parm)), new_args, complain, in_decl);
6255 TREE_CONSTANT (argument_pack) = 1;
6258 SET_ARGUMENT_PACK_ARGS (argument_pack, packed_args);
6259 #ifdef ENABLE_CHECKING
6260 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (packed_args,
6261 TREE_VEC_LENGTH (packed_args));
6263 return argument_pack;
6266 /* Convert all template arguments to their appropriate types, and
6267 return a vector containing the innermost resulting template
6268 arguments. If any error occurs, return error_mark_node. Error and
6269 warning messages are issued under control of COMPLAIN.
6271 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6272 for arguments not specified in ARGS. Otherwise, if
6273 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6274 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6275 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6279 coerce_template_parms (tree parms,
6282 tsubst_flags_t complain,
6283 bool require_all_args,
6284 bool use_default_args)
6286 int nparms, nargs, parm_idx, arg_idx, lost = 0;
6289 tree new_inner_args;
6290 int saved_unevaluated_operand;
6291 int saved_inhibit_evaluation_warnings;
6293 /* When used as a boolean value, indicates whether this is a
6294 variadic template parameter list. Since it's an int, we can also
6295 subtract it from nparms to get the number of non-variadic
6299 if (args == error_mark_node)
6300 return error_mark_node;
6302 nparms = TREE_VEC_LENGTH (parms);
6304 /* Determine if there are any parameter packs. */
6305 for (parm_idx = 0; parm_idx < nparms; ++parm_idx)
6307 tree tparm = TREE_VALUE (TREE_VEC_ELT (parms, parm_idx));
6308 if (template_parameter_pack_p (tparm))
6312 inner_args = INNERMOST_TEMPLATE_ARGS (args);
6313 /* If there are 0 or 1 parameter packs, we need to expand any argument
6314 packs so that we can deduce a parameter pack from some non-packed args
6315 followed by an argument pack, as in variadic85.C. If there are more
6316 than that, we need to leave argument packs intact so the arguments are
6317 assigned to the right parameter packs. This should only happen when
6318 dealing with a nested class inside a partial specialization of a class
6319 template, as in variadic92.C. */
6320 if (variadic_p <= 1)
6321 inner_args = expand_template_argument_pack (inner_args);
6323 nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
6324 if ((nargs > nparms && !variadic_p)
6325 || (nargs < nparms - variadic_p
6327 && (!use_default_args
6328 || (TREE_VEC_ELT (parms, nargs) != error_mark_node
6329 && !TREE_PURPOSE (TREE_VEC_ELT (parms, nargs))))))
6331 if (complain & tf_error)
6336 error ("wrong number of template arguments "
6337 "(%d, should be %d or more)", nargs, nparms);
6340 error ("wrong number of template arguments "
6341 "(%d, should be %d)", nargs, nparms);
6344 error ("provided for %q+D", in_decl);
6347 return error_mark_node;
6350 /* We need to evaluate the template arguments, even though this
6351 template-id may be nested within a "sizeof". */
6352 saved_unevaluated_operand = cp_unevaluated_operand;
6353 cp_unevaluated_operand = 0;
6354 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
6355 c_inhibit_evaluation_warnings = 0;
6356 new_inner_args = make_tree_vec (nparms);
6357 new_args = add_outermost_template_args (args, new_inner_args);
6358 for (parm_idx = 0, arg_idx = 0; parm_idx < nparms; parm_idx++, arg_idx++)
6363 /* Get the Ith template parameter. */
6364 parm = TREE_VEC_ELT (parms, parm_idx);
6366 if (parm == error_mark_node)
6368 TREE_VEC_ELT (new_inner_args, arg_idx) = error_mark_node;
6372 /* Calculate the next argument. */
6373 if (arg_idx < nargs)
6374 arg = TREE_VEC_ELT (inner_args, arg_idx);
6378 if (template_parameter_pack_p (TREE_VALUE (parm))
6379 && !(arg && ARGUMENT_PACK_P (arg)))
6381 /* All remaining arguments will be placed in the
6382 template parameter pack PARM. */
6383 arg = coerce_template_parameter_pack (parms, parm_idx, args,
6384 inner_args, arg_idx,
6388 /* Store this argument. */
6389 if (arg == error_mark_node)
6391 TREE_VEC_ELT (new_inner_args, parm_idx) = arg;
6393 /* We are done with all of the arguments. */
6400 if (PACK_EXPANSION_P (arg))
6402 if (complain & tf_error)
6404 /* FIXME this restriction was removed by N2555; see
6406 /* If ARG is a pack expansion, but PARM is not a
6407 template parameter pack (if it were, we would have
6408 handled it above), we're trying to expand into a
6409 fixed-length argument list. */
6410 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
6411 sorry ("cannot expand %<%E%> into a fixed-length "
6412 "argument list", arg);
6414 sorry ("cannot expand %<%T%> into a fixed-length "
6415 "argument list", arg);
6420 else if (require_all_args)
6422 /* There must be a default arg in this case. */
6423 arg = tsubst_template_arg (TREE_PURPOSE (parm), new_args,
6425 /* The position of the first default template argument,
6426 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6428 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args))
6429 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args, arg_idx);
6434 if (arg == error_mark_node)
6436 if (complain & tf_error)
6437 error ("template argument %d is invalid", arg_idx + 1);
6440 /* This only occurs if there was an error in the template
6441 parameter list itself (which we would already have
6442 reported) that we are trying to recover from, e.g., a class
6443 template with a parameter list such as
6444 template<typename..., typename>. */
6447 arg = convert_template_argument (TREE_VALUE (parm),
6448 arg, new_args, complain,
6451 if (arg == error_mark_node)
6453 TREE_VEC_ELT (new_inner_args, arg_idx) = arg;
6455 cp_unevaluated_operand = saved_unevaluated_operand;
6456 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
6459 return error_mark_node;
6461 #ifdef ENABLE_CHECKING
6462 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args))
6463 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args,
6464 TREE_VEC_LENGTH (new_inner_args));
6467 return new_inner_args;
6470 /* Returns 1 if template args OT and NT are equivalent. */
6473 template_args_equal (tree ot, tree nt)
6478 if (TREE_CODE (nt) == TREE_VEC)
6479 /* For member templates */
6480 return TREE_CODE (ot) == TREE_VEC && comp_template_args (ot, nt);
6481 else if (PACK_EXPANSION_P (ot))
6482 return PACK_EXPANSION_P (nt)
6483 && template_args_equal (PACK_EXPANSION_PATTERN (ot),
6484 PACK_EXPANSION_PATTERN (nt));
6485 else if (ARGUMENT_PACK_P (ot))
6490 if (!ARGUMENT_PACK_P (nt))
6493 opack = ARGUMENT_PACK_ARGS (ot);
6494 npack = ARGUMENT_PACK_ARGS (nt);
6495 len = TREE_VEC_LENGTH (opack);
6496 if (TREE_VEC_LENGTH (npack) != len)
6498 for (i = 0; i < len; ++i)
6499 if (!template_args_equal (TREE_VEC_ELT (opack, i),
6500 TREE_VEC_ELT (npack, i)))
6504 else if (ot && TREE_CODE (ot) == ARGUMENT_PACK_SELECT)
6506 /* We get here probably because we are in the middle of substituting
6507 into the pattern of a pack expansion. In that case the
6508 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
6509 interested in. So we want to use the initial pack argument for
6511 ot = ARGUMENT_PACK_SELECT_FROM_PACK (ot);
6512 if (nt && TREE_CODE (nt) == ARGUMENT_PACK_SELECT)
6513 nt = ARGUMENT_PACK_SELECT_FROM_PACK (nt);
6514 return template_args_equal (ot, nt);
6516 else if (TYPE_P (nt))
6517 return TYPE_P (ot) && same_type_p (ot, nt);
6518 else if (TREE_CODE (ot) == TREE_VEC || TYPE_P (ot))
6521 return cp_tree_equal (ot, nt);
6524 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
6525 of template arguments. Returns 0 otherwise. */
6528 comp_template_args (tree oldargs, tree newargs)
6532 if (TREE_VEC_LENGTH (oldargs) != TREE_VEC_LENGTH (newargs))
6535 for (i = 0; i < TREE_VEC_LENGTH (oldargs); ++i)
6537 tree nt = TREE_VEC_ELT (newargs, i);
6538 tree ot = TREE_VEC_ELT (oldargs, i);
6540 if (! template_args_equal (ot, nt))
6547 add_pending_template (tree d)
6549 tree ti = (TYPE_P (d)
6550 ? CLASSTYPE_TEMPLATE_INFO (d)
6551 : DECL_TEMPLATE_INFO (d));
6552 struct pending_template *pt;
6555 if (TI_PENDING_TEMPLATE_FLAG (ti))
6558 /* We are called both from instantiate_decl, where we've already had a
6559 tinst_level pushed, and instantiate_template, where we haven't.
6561 level = !current_tinst_level || current_tinst_level->decl != d;
6564 push_tinst_level (d);
6566 pt = ggc_alloc_pending_template ();
6568 pt->tinst = current_tinst_level;
6569 if (last_pending_template)
6570 last_pending_template->next = pt;
6572 pending_templates = pt;
6574 last_pending_template = pt;
6576 TI_PENDING_TEMPLATE_FLAG (ti) = 1;
6583 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
6584 ARGLIST. Valid choices for FNS are given in the cp-tree.def
6585 documentation for TEMPLATE_ID_EXPR. */
6588 lookup_template_function (tree fns, tree arglist)
6592 if (fns == error_mark_node || arglist == error_mark_node)
6593 return error_mark_node;
6595 gcc_assert (!arglist || TREE_CODE (arglist) == TREE_VEC);
6596 gcc_assert (fns && (is_overloaded_fn (fns)
6597 || TREE_CODE (fns) == IDENTIFIER_NODE));
6599 if (BASELINK_P (fns))
6601 BASELINK_FUNCTIONS (fns) = build2 (TEMPLATE_ID_EXPR,
6603 BASELINK_FUNCTIONS (fns),
6608 type = TREE_TYPE (fns);
6609 if (TREE_CODE (fns) == OVERLOAD || !type)
6610 type = unknown_type_node;
6612 return build2 (TEMPLATE_ID_EXPR, type, fns, arglist);
6615 /* Within the scope of a template class S<T>, the name S gets bound
6616 (in build_self_reference) to a TYPE_DECL for the class, not a
6617 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
6618 or one of its enclosing classes, and that type is a template,
6619 return the associated TEMPLATE_DECL. Otherwise, the original
6622 Also handle the case when DECL is a TREE_LIST of ambiguous
6623 injected-class-names from different bases. */
6626 maybe_get_template_decl_from_type_decl (tree decl)
6628 if (decl == NULL_TREE)
6631 /* DR 176: A lookup that finds an injected-class-name (10.2
6632 [class.member.lookup]) can result in an ambiguity in certain cases
6633 (for example, if it is found in more than one base class). If all of
6634 the injected-class-names that are found refer to specializations of
6635 the same class template, and if the name is followed by a
6636 template-argument-list, the reference refers to the class template
6637 itself and not a specialization thereof, and is not ambiguous. */
6638 if (TREE_CODE (decl) == TREE_LIST)
6640 tree t, tmpl = NULL_TREE;
6641 for (t = decl; t; t = TREE_CHAIN (t))
6643 tree elt = maybe_get_template_decl_from_type_decl (TREE_VALUE (t));
6646 else if (tmpl != elt)
6649 if (tmpl && t == NULL_TREE)
6655 return (decl != NULL_TREE
6656 && DECL_SELF_REFERENCE_P (decl)
6657 && CLASSTYPE_TEMPLATE_INFO (TREE_TYPE (decl)))
6658 ? CLASSTYPE_TI_TEMPLATE (TREE_TYPE (decl)) : decl;
6661 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
6662 parameters, find the desired type.
6664 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
6666 IN_DECL, if non-NULL, is the template declaration we are trying to
6669 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
6670 the class we are looking up.
6672 Issue error and warning messages under control of COMPLAIN.
6674 If the template class is really a local class in a template
6675 function, then the FUNCTION_CONTEXT is the function in which it is
6678 ??? Note that this function is currently called *twice* for each
6679 template-id: the first time from the parser, while creating the
6680 incomplete type (finish_template_type), and the second type during the
6681 real instantiation (instantiate_template_class). This is surely something
6682 that we want to avoid. It also causes some problems with argument
6683 coercion (see convert_nontype_argument for more information on this). */
6686 lookup_template_class (tree d1,
6691 tsubst_flags_t complain)
6693 tree templ = NULL_TREE, parmlist;
6700 timevar_push (TV_NAME_LOOKUP);
6702 if (TREE_CODE (d1) == IDENTIFIER_NODE)
6704 tree value = innermost_non_namespace_value (d1);
6705 if (value && DECL_TEMPLATE_TEMPLATE_PARM_P (value))
6710 push_decl_namespace (context);
6711 templ = lookup_name (d1);
6712 templ = maybe_get_template_decl_from_type_decl (templ);
6714 pop_decl_namespace ();
6717 context = DECL_CONTEXT (templ);
6719 else if (TREE_CODE (d1) == TYPE_DECL && MAYBE_CLASS_TYPE_P (TREE_TYPE (d1)))
6721 tree type = TREE_TYPE (d1);
6723 /* If we are declaring a constructor, say A<T>::A<T>, we will get
6724 an implicit typename for the second A. Deal with it. */
6725 if (TREE_CODE (type) == TYPENAME_TYPE && TREE_TYPE (type))
6726 type = TREE_TYPE (type);
6728 if (CLASSTYPE_TEMPLATE_INFO (type))
6730 templ = CLASSTYPE_TI_TEMPLATE (type);
6731 d1 = DECL_NAME (templ);
6734 else if (TREE_CODE (d1) == ENUMERAL_TYPE
6735 || (TYPE_P (d1) && MAYBE_CLASS_TYPE_P (d1)))
6737 templ = TYPE_TI_TEMPLATE (d1);
6738 d1 = DECL_NAME (templ);
6740 else if (TREE_CODE (d1) == TEMPLATE_DECL
6741 && DECL_TEMPLATE_RESULT (d1)
6742 && TREE_CODE (DECL_TEMPLATE_RESULT (d1)) == TYPE_DECL)
6745 d1 = DECL_NAME (templ);
6746 context = DECL_CONTEXT (templ);
6749 /* Issue an error message if we didn't find a template. */
6752 if (complain & tf_error)
6753 error ("%qT is not a template", d1);
6754 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6757 if (TREE_CODE (templ) != TEMPLATE_DECL
6758 /* Make sure it's a user visible template, if it was named by
6760 || ((complain & tf_user) && !DECL_TEMPLATE_PARM_P (templ)
6761 && !PRIMARY_TEMPLATE_P (templ)))
6763 if (complain & tf_error)
6765 error ("non-template type %qT used as a template", d1);
6767 error ("for template declaration %q+D", in_decl);
6769 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6772 complain &= ~tf_user;
6774 if (DECL_TEMPLATE_TEMPLATE_PARM_P (templ))
6776 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
6777 template arguments */
6783 parmlist = DECL_INNERMOST_TEMPLATE_PARMS (templ);
6785 /* Consider an example where a template template parameter declared as
6787 template <class T, class U = std::allocator<T> > class TT
6789 The template parameter level of T and U are one level larger than
6790 of TT. To proper process the default argument of U, say when an
6791 instantiation `TT<int>' is seen, we need to build the full
6792 arguments containing {int} as the innermost level. Outer levels,
6793 available when not appearing as default template argument, can be
6794 obtained from the arguments of the enclosing template.
6796 Suppose that TT is later substituted with std::vector. The above
6797 instantiation is `TT<int, std::allocator<T> >' with TT at
6798 level 1, and T at level 2, while the template arguments at level 1
6799 becomes {std::vector} and the inner level 2 is {int}. */
6801 outer = DECL_CONTEXT (templ);
6803 outer = TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (outer)));
6804 else if (current_template_parms)
6805 /* This is an argument of the current template, so we haven't set
6806 DECL_CONTEXT yet. */
6807 outer = current_template_args ();
6810 arglist = add_to_template_args (outer, arglist);
6812 arglist2 = coerce_template_parms (parmlist, arglist, templ,
6814 /*require_all_args=*/true,
6815 /*use_default_args=*/true);
6816 if (arglist2 == error_mark_node
6817 || (!uses_template_parms (arglist2)
6818 && check_instantiated_args (templ, arglist2, complain)))
6819 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6821 parm = bind_template_template_parm (TREE_TYPE (templ), arglist2);
6822 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, parm);
6826 tree template_type = TREE_TYPE (templ);
6829 tree found = NULL_TREE;
6832 int is_dependent_type;
6833 int use_partial_inst_tmpl = false;
6835 gen_tmpl = most_general_template (templ);
6836 parmlist = DECL_TEMPLATE_PARMS (gen_tmpl);
6837 parm_depth = TMPL_PARMS_DEPTH (parmlist);
6838 arg_depth = TMPL_ARGS_DEPTH (arglist);
6840 if (arg_depth == 1 && parm_depth > 1)
6842 /* We've been given an incomplete set of template arguments.
6845 template <class T> struct S1 {
6846 template <class U> struct S2 {};
6847 template <class U> struct S2<U*> {};
6850 we will be called with an ARGLIST of `U*', but the
6851 TEMPLATE will be `template <class T> template
6852 <class U> struct S1<T>::S2'. We must fill in the missing
6855 = add_outermost_template_args (TYPE_TI_ARGS (TREE_TYPE (templ)),
6857 arg_depth = TMPL_ARGS_DEPTH (arglist);
6860 /* Now we should have enough arguments. */
6861 gcc_assert (parm_depth == arg_depth);
6863 /* From here on, we're only interested in the most general
6866 /* Calculate the BOUND_ARGS. These will be the args that are
6867 actually tsubst'd into the definition to create the
6871 /* We have multiple levels of arguments to coerce, at once. */
6873 int saved_depth = TMPL_ARGS_DEPTH (arglist);
6875 tree bound_args = make_tree_vec (parm_depth);
6877 for (i = saved_depth,
6878 t = DECL_TEMPLATE_PARMS (gen_tmpl);
6879 i > 0 && t != NULL_TREE;
6880 --i, t = TREE_CHAIN (t))
6883 if (i == saved_depth)
6884 a = coerce_template_parms (TREE_VALUE (t),
6887 /*require_all_args=*/true,
6888 /*use_default_args=*/true);
6890 /* Outer levels should have already been coerced. */
6891 a = TMPL_ARGS_LEVEL (arglist, i);
6893 /* Don't process further if one of the levels fails. */
6894 if (a == error_mark_node)
6896 /* Restore the ARGLIST to its full size. */
6897 TREE_VEC_LENGTH (arglist) = saved_depth;
6898 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6901 SET_TMPL_ARGS_LEVEL (bound_args, i, a);
6903 /* We temporarily reduce the length of the ARGLIST so
6904 that coerce_template_parms will see only the arguments
6905 corresponding to the template parameters it is
6907 TREE_VEC_LENGTH (arglist)--;
6910 /* Restore the ARGLIST to its full size. */
6911 TREE_VEC_LENGTH (arglist) = saved_depth;
6913 arglist = bound_args;
6917 = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parmlist),
6918 INNERMOST_TEMPLATE_ARGS (arglist),
6921 /*require_all_args=*/true,
6922 /*use_default_args=*/true);
6924 if (arglist == error_mark_node)
6925 /* We were unable to bind the arguments. */
6926 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6928 /* In the scope of a template class, explicit references to the
6929 template class refer to the type of the template, not any
6930 instantiation of it. For example, in:
6932 template <class T> class C { void f(C<T>); }
6934 the `C<T>' is just the same as `C'. Outside of the
6935 class, however, such a reference is an instantiation. */
6937 || !PRIMARY_TEMPLATE_P (gen_tmpl)
6938 || currently_open_class (template_type))
6939 /* comp_template_args is expensive, check it last. */
6940 && comp_template_args (TYPE_TI_ARGS (template_type),
6942 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, template_type);
6944 /* If we already have this specialization, return it. */
6945 elt.tmpl = gen_tmpl;
6947 hash = hash_specialization (&elt);
6948 entry = (spec_entry *) htab_find_with_hash (type_specializations,
6952 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, entry->spec);
6954 is_dependent_type = uses_template_parms (arglist);
6956 /* If the deduced arguments are invalid, then the binding
6958 if (!is_dependent_type
6959 && check_instantiated_args (gen_tmpl,
6960 INNERMOST_TEMPLATE_ARGS (arglist),
6962 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6964 if (!is_dependent_type
6965 && !PRIMARY_TEMPLATE_P (gen_tmpl)
6966 && !LAMBDA_TYPE_P (TREE_TYPE (gen_tmpl))
6967 && TREE_CODE (CP_DECL_CONTEXT (gen_tmpl)) == NAMESPACE_DECL)
6969 found = xref_tag_from_type (TREE_TYPE (gen_tmpl),
6970 DECL_NAME (gen_tmpl),
6971 /*tag_scope=*/ts_global);
6972 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, found);
6975 context = tsubst (DECL_CONTEXT (gen_tmpl), arglist,
6978 context = global_namespace;
6980 /* Create the type. */
6981 if (TREE_CODE (template_type) == ENUMERAL_TYPE)
6983 if (!is_dependent_type)
6985 set_current_access_from_decl (TYPE_NAME (template_type));
6986 t = start_enum (TYPE_IDENTIFIER (template_type), NULL_TREE,
6987 tsubst (ENUM_UNDERLYING_TYPE (template_type),
6988 arglist, complain, in_decl),
6989 SCOPED_ENUM_P (template_type), NULL);
6993 /* We don't want to call start_enum for this type, since
6994 the values for the enumeration constants may involve
6995 template parameters. And, no one should be interested
6996 in the enumeration constants for such a type. */
6997 t = cxx_make_type (ENUMERAL_TYPE);
6998 SET_SCOPED_ENUM_P (t, SCOPED_ENUM_P (template_type));
7000 SET_OPAQUE_ENUM_P (t, OPAQUE_ENUM_P (template_type));
7001 ENUM_FIXED_UNDERLYING_TYPE_P (t)
7002 = ENUM_FIXED_UNDERLYING_TYPE_P (template_type);
7006 t = make_class_type (TREE_CODE (template_type));
7007 CLASSTYPE_DECLARED_CLASS (t)
7008 = CLASSTYPE_DECLARED_CLASS (template_type);
7009 SET_CLASSTYPE_IMPLICIT_INSTANTIATION (t);
7010 TYPE_FOR_JAVA (t) = TYPE_FOR_JAVA (template_type);
7012 /* A local class. Make sure the decl gets registered properly. */
7013 if (context == current_function_decl)
7014 pushtag (DECL_NAME (gen_tmpl), t, /*tag_scope=*/ts_current);
7016 if (comp_template_args (CLASSTYPE_TI_ARGS (template_type), arglist))
7017 /* This instantiation is another name for the primary
7018 template type. Set the TYPE_CANONICAL field
7020 TYPE_CANONICAL (t) = template_type;
7021 else if (any_template_arguments_need_structural_equality_p (arglist))
7022 /* Some of the template arguments require structural
7023 equality testing, so this template class requires
7024 structural equality testing. */
7025 SET_TYPE_STRUCTURAL_EQUALITY (t);
7028 /* If we called start_enum or pushtag above, this information
7029 will already be set up. */
7032 TYPE_CONTEXT (t) = FROB_CONTEXT (context);
7034 type_decl = create_implicit_typedef (DECL_NAME (gen_tmpl), t);
7035 DECL_CONTEXT (type_decl) = TYPE_CONTEXT (t);
7036 DECL_SOURCE_LOCATION (type_decl)
7037 = DECL_SOURCE_LOCATION (TYPE_STUB_DECL (template_type));
7040 type_decl = TYPE_NAME (t);
7042 TREE_PRIVATE (type_decl)
7043 = TREE_PRIVATE (TYPE_STUB_DECL (template_type));
7044 TREE_PROTECTED (type_decl)
7045 = TREE_PROTECTED (TYPE_STUB_DECL (template_type));
7046 if (CLASSTYPE_VISIBILITY_SPECIFIED (template_type))
7048 DECL_VISIBILITY_SPECIFIED (type_decl) = 1;
7049 DECL_VISIBILITY (type_decl) = CLASSTYPE_VISIBILITY (template_type);
7052 /* Let's consider the explicit specialization of a member
7053 of a class template specialization that is implicitely instantiated,
7058 template<class U> struct M {}; //#0
7063 struct S<int>::M<char> //#1
7067 [temp.expl.spec]/4 says this is valid.
7069 In this case, when we write:
7072 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7075 When we encounter #1, we want to store the partial instantiation
7076 of M (template<class T> S<int>::M<T>) in it's CLASSTYPE_TI_TEMPLATE.
7078 For all cases other than this "explicit specialization of member of a
7079 class template", we just want to store the most general template into
7080 the CLASSTYPE_TI_TEMPLATE of M.
7082 This case of "explicit specialization of member of a class template"
7084 1/ the enclosing class is an instantiation of, and therefore not
7085 the same as, the context of the most general template, and
7086 2/ we aren't looking at the partial instantiation itself, i.e.
7087 the innermost arguments are not the same as the innermost parms of
7088 the most general template.
7090 So it's only when 1/ and 2/ happens that we want to use the partial
7091 instantiation of the member template in lieu of its most general
7094 if (PRIMARY_TEMPLATE_P (gen_tmpl)
7095 && TMPL_ARGS_HAVE_MULTIPLE_LEVELS (arglist)
7096 /* the enclosing class must be an instantiation... */
7097 && CLASS_TYPE_P (context)
7098 && !same_type_p (context, DECL_CONTEXT (gen_tmpl)))
7100 tree partial_inst_args;
7101 TREE_VEC_LENGTH (arglist)--;
7102 ++processing_template_decl;
7104 tsubst (INNERMOST_TEMPLATE_ARGS
7105 (CLASSTYPE_TI_ARGS (TREE_TYPE (gen_tmpl))),
7106 arglist, complain, NULL_TREE);
7107 --processing_template_decl;
7108 TREE_VEC_LENGTH (arglist)++;
7109 use_partial_inst_tmpl =
7110 /*...and we must not be looking at the partial instantiation
7112 !comp_template_args (INNERMOST_TEMPLATE_ARGS (arglist),
7116 if (!use_partial_inst_tmpl)
7117 /* This case is easy; there are no member templates involved. */
7121 /* This is a full instantiation of a member template. Find
7122 the partial instantiation of which this is an instance. */
7124 /* Temporarily reduce by one the number of levels in the ARGLIST
7125 so as to avoid comparing the last set of arguments. */
7126 TREE_VEC_LENGTH (arglist)--;
7127 found = tsubst (gen_tmpl, arglist, complain, NULL_TREE);
7128 TREE_VEC_LENGTH (arglist)++;
7129 found = CLASSTYPE_TI_TEMPLATE (found);
7132 SET_TYPE_TEMPLATE_INFO (t, build_template_info (found, arglist));
7135 slot = (spec_entry **) htab_find_slot_with_hash (type_specializations,
7136 &elt, hash, INSERT);
7137 *slot = ggc_alloc_spec_entry ();
7140 /* Note this use of the partial instantiation so we can check it
7141 later in maybe_process_partial_specialization. */
7142 DECL_TEMPLATE_INSTANTIATIONS (templ)
7143 = tree_cons (arglist, t,
7144 DECL_TEMPLATE_INSTANTIATIONS (templ));
7146 if (TREE_CODE (t) == ENUMERAL_TYPE && !is_dependent_type)
7147 /* Now that the type has been registered on the instantiations
7148 list, we set up the enumerators. Because the enumeration
7149 constants may involve the enumeration type itself, we make
7150 sure to register the type first, and then create the
7151 constants. That way, doing tsubst_expr for the enumeration
7152 constants won't result in recursive calls here; we'll find
7153 the instantiation and exit above. */
7154 tsubst_enum (template_type, t, arglist);
7156 if (is_dependent_type)
7157 /* If the type makes use of template parameters, the
7158 code that generates debugging information will crash. */
7159 DECL_IGNORED_P (TYPE_STUB_DECL (t)) = 1;
7161 /* Possibly limit visibility based on template args. */
7162 TREE_PUBLIC (type_decl) = 1;
7163 determine_visibility (type_decl);
7165 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, t);
7167 timevar_pop (TV_NAME_LOOKUP);
7174 /* True when we should also visit template parameters that occur in
7175 non-deduced contexts. */
7176 bool include_nondeduced_p;
7177 struct pointer_set_t *visited;
7180 /* Called from for_each_template_parm via walk_tree. */
7183 for_each_template_parm_r (tree *tp, int *walk_subtrees, void *d)
7186 struct pair_fn_data *pfd = (struct pair_fn_data *) d;
7187 tree_fn_t fn = pfd->fn;
7188 void *data = pfd->data;
7191 && (pfd->include_nondeduced_p || TREE_CODE (t) != TYPENAME_TYPE)
7192 && for_each_template_parm (TYPE_CONTEXT (t), fn, data, pfd->visited,
7193 pfd->include_nondeduced_p))
7194 return error_mark_node;
7196 switch (TREE_CODE (t))
7199 if (TYPE_PTRMEMFUNC_P (t))
7205 if (!TYPE_TEMPLATE_INFO (t))
7207 else if (for_each_template_parm (TI_ARGS (TYPE_TEMPLATE_INFO (t)),
7208 fn, data, pfd->visited,
7209 pfd->include_nondeduced_p))
7210 return error_mark_node;
7214 if (for_each_template_parm (TYPE_MIN_VALUE (t),
7215 fn, data, pfd->visited,
7216 pfd->include_nondeduced_p)
7217 || for_each_template_parm (TYPE_MAX_VALUE (t),
7218 fn, data, pfd->visited,
7219 pfd->include_nondeduced_p))
7220 return error_mark_node;
7224 /* Since we're not going to walk subtrees, we have to do this
7226 if (for_each_template_parm (TYPE_METHOD_BASETYPE (t), fn, data,
7227 pfd->visited, pfd->include_nondeduced_p))
7228 return error_mark_node;
7232 /* Check the return type. */
7233 if (for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
7234 pfd->include_nondeduced_p))
7235 return error_mark_node;
7237 /* Check the parameter types. Since default arguments are not
7238 instantiated until they are needed, the TYPE_ARG_TYPES may
7239 contain expressions that involve template parameters. But,
7240 no-one should be looking at them yet. And, once they're
7241 instantiated, they don't contain template parameters, so
7242 there's no point in looking at them then, either. */
7246 for (parm = TYPE_ARG_TYPES (t); parm; parm = TREE_CHAIN (parm))
7247 if (for_each_template_parm (TREE_VALUE (parm), fn, data,
7248 pfd->visited, pfd->include_nondeduced_p))
7249 return error_mark_node;
7251 /* Since we've already handled the TYPE_ARG_TYPES, we don't
7252 want walk_tree walking into them itself. */
7258 if (pfd->include_nondeduced_p
7259 && for_each_template_parm (TYPE_FIELDS (t), fn, data,
7261 pfd->include_nondeduced_p))
7262 return error_mark_node;
7267 if (DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t)
7268 && for_each_template_parm (DECL_TI_ARGS (t), fn, data,
7269 pfd->visited, pfd->include_nondeduced_p))
7270 return error_mark_node;
7275 if (TREE_CODE (t) == CONST_DECL && DECL_TEMPLATE_PARM_P (t)
7276 && for_each_template_parm (DECL_INITIAL (t), fn, data,
7277 pfd->visited, pfd->include_nondeduced_p))
7278 return error_mark_node;
7279 if (DECL_CONTEXT (t)
7280 && pfd->include_nondeduced_p
7281 && for_each_template_parm (DECL_CONTEXT (t), fn, data,
7282 pfd->visited, pfd->include_nondeduced_p))
7283 return error_mark_node;
7286 case BOUND_TEMPLATE_TEMPLATE_PARM:
7287 /* Record template parameters such as `T' inside `TT<T>'. */
7288 if (for_each_template_parm (TYPE_TI_ARGS (t), fn, data, pfd->visited,
7289 pfd->include_nondeduced_p))
7290 return error_mark_node;
7293 case TEMPLATE_TEMPLATE_PARM:
7294 case TEMPLATE_TYPE_PARM:
7295 case TEMPLATE_PARM_INDEX:
7296 if (fn && (*fn)(t, data))
7297 return error_mark_node;
7299 return error_mark_node;
7303 /* A template template parameter is encountered. */
7304 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t)
7305 && for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
7306 pfd->include_nondeduced_p))
7307 return error_mark_node;
7309 /* Already substituted template template parameter */
7315 || for_each_template_parm (TYPENAME_TYPE_FULLNAME (t), fn,
7317 pfd->include_nondeduced_p))
7318 return error_mark_node;
7322 if (TREE_TYPE (t) && TYPE_PTRMEMFUNC_P (TREE_TYPE (t))
7323 && pfd->include_nondeduced_p
7324 && for_each_template_parm (TYPE_PTRMEMFUNC_FN_TYPE
7325 (TREE_TYPE (t)), fn, data,
7326 pfd->visited, pfd->include_nondeduced_p))
7327 return error_mark_node;
7332 /* If there's no type, then this thing must be some expression
7333 involving template parameters. */
7334 if (!fn && !TREE_TYPE (t))
7335 return error_mark_node;
7340 case REINTERPRET_CAST_EXPR:
7341 case CONST_CAST_EXPR:
7342 case STATIC_CAST_EXPR:
7343 case DYNAMIC_CAST_EXPR:
7347 case PSEUDO_DTOR_EXPR:
7349 return error_mark_node;
7356 /* We didn't find any template parameters we liked. */
7360 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
7361 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
7362 call FN with the parameter and the DATA.
7363 If FN returns nonzero, the iteration is terminated, and
7364 for_each_template_parm returns 1. Otherwise, the iteration
7365 continues. If FN never returns a nonzero value, the value
7366 returned by for_each_template_parm is 0. If FN is NULL, it is
7367 considered to be the function which always returns 1.
7369 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
7370 parameters that occur in non-deduced contexts. When false, only
7371 visits those template parameters that can be deduced. */
7374 for_each_template_parm (tree t, tree_fn_t fn, void* data,
7375 struct pointer_set_t *visited,
7376 bool include_nondeduced_p)
7378 struct pair_fn_data pfd;
7384 pfd.include_nondeduced_p = include_nondeduced_p;
7386 /* Walk the tree. (Conceptually, we would like to walk without
7387 duplicates, but for_each_template_parm_r recursively calls
7388 for_each_template_parm, so we would need to reorganize a fair
7389 bit to use walk_tree_without_duplicates, so we keep our own
7392 pfd.visited = visited;
7394 pfd.visited = pointer_set_create ();
7395 result = cp_walk_tree (&t,
7396 for_each_template_parm_r,
7398 pfd.visited) != NULL_TREE;
7403 pointer_set_destroy (pfd.visited);
7410 /* Returns true if T depends on any template parameter. */
7413 uses_template_parms (tree t)
7416 int saved_processing_template_decl;
7418 saved_processing_template_decl = processing_template_decl;
7419 if (!saved_processing_template_decl)
7420 processing_template_decl = 1;
7422 dependent_p = dependent_type_p (t);
7423 else if (TREE_CODE (t) == TREE_VEC)
7424 dependent_p = any_dependent_template_arguments_p (t);
7425 else if (TREE_CODE (t) == TREE_LIST)
7426 dependent_p = (uses_template_parms (TREE_VALUE (t))
7427 || uses_template_parms (TREE_CHAIN (t)));
7428 else if (TREE_CODE (t) == TYPE_DECL)
7429 dependent_p = dependent_type_p (TREE_TYPE (t));
7432 || TREE_CODE (t) == TEMPLATE_PARM_INDEX
7433 || TREE_CODE (t) == OVERLOAD
7434 || TREE_CODE (t) == BASELINK
7435 || TREE_CODE (t) == IDENTIFIER_NODE
7436 || TREE_CODE (t) == TRAIT_EXPR
7437 || TREE_CODE (t) == CONSTRUCTOR
7438 || CONSTANT_CLASS_P (t))
7439 dependent_p = (type_dependent_expression_p (t)
7440 || value_dependent_expression_p (t));
7443 gcc_assert (t == error_mark_node);
7444 dependent_p = false;
7447 processing_template_decl = saved_processing_template_decl;
7452 /* Returns true if T depends on any template parameter with level LEVEL. */
7455 uses_template_parms_level (tree t, int level)
7457 return for_each_template_parm (t, template_parm_this_level_p, &level, NULL,
7458 /*include_nondeduced_p=*/true);
7461 static int tinst_depth;
7462 extern int max_tinst_depth;
7463 #ifdef GATHER_STATISTICS
7466 static int tinst_level_tick;
7467 static int last_template_error_tick;
7469 /* We're starting to instantiate D; record the template instantiation context
7470 for diagnostics and to restore it later. */
7473 push_tinst_level (tree d)
7475 struct tinst_level *new_level;
7477 if (tinst_depth >= max_tinst_depth)
7479 /* If the instantiation in question still has unbound template parms,
7480 we don't really care if we can't instantiate it, so just return.
7481 This happens with base instantiation for implicit `typename'. */
7482 if (uses_template_parms (d))
7485 last_template_error_tick = tinst_level_tick;
7486 error ("template instantiation depth exceeds maximum of %d (use "
7487 "-ftemplate-depth= to increase the maximum) instantiating %qD",
7488 max_tinst_depth, d);
7490 print_instantiation_context ();
7495 new_level = ggc_alloc_tinst_level ();
7496 new_level->decl = d;
7497 new_level->locus = input_location;
7498 new_level->in_system_header_p = in_system_header;
7499 new_level->next = current_tinst_level;
7500 current_tinst_level = new_level;
7503 #ifdef GATHER_STATISTICS
7504 if (tinst_depth > depth_reached)
7505 depth_reached = tinst_depth;
7512 /* We're done instantiating this template; return to the instantiation
7516 pop_tinst_level (void)
7518 /* Restore the filename and line number stashed away when we started
7519 this instantiation. */
7520 input_location = current_tinst_level->locus;
7521 current_tinst_level = current_tinst_level->next;
7526 /* We're instantiating a deferred template; restore the template
7527 instantiation context in which the instantiation was requested, which
7528 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
7531 reopen_tinst_level (struct tinst_level *level)
7533 struct tinst_level *t;
7536 for (t = level; t; t = t->next)
7539 current_tinst_level = level;
7544 /* Returns the TINST_LEVEL which gives the original instantiation
7547 struct tinst_level *
7548 outermost_tinst_level (void)
7550 struct tinst_level *level = current_tinst_level;
7553 level = level->next;
7557 /* Returns TRUE if PARM is a parameter of the template TEMPL. */
7560 parameter_of_template_p (tree parm, tree templ)
7565 if (!parm || !templ)
7568 gcc_assert (DECL_TEMPLATE_PARM_P (parm));
7569 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
7571 parms = DECL_TEMPLATE_PARMS (templ);
7572 parms = INNERMOST_TEMPLATE_PARMS (parms);
7574 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
7575 if (parm == TREE_VALUE (TREE_VEC_ELT (parms, i)))
7581 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
7582 vector of template arguments, as for tsubst.
7584 Returns an appropriate tsubst'd friend declaration. */
7587 tsubst_friend_function (tree decl, tree args)
7591 if (TREE_CODE (decl) == FUNCTION_DECL
7592 && DECL_TEMPLATE_INSTANTIATION (decl)
7593 && TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
7594 /* This was a friend declared with an explicit template
7595 argument list, e.g.:
7599 to indicate that f was a template instantiation, not a new
7600 function declaration. Now, we have to figure out what
7601 instantiation of what template. */
7603 tree template_id, arglist, fns;
7606 tree ns = decl_namespace_context (TYPE_MAIN_DECL (current_class_type));
7608 /* Friend functions are looked up in the containing namespace scope.
7609 We must enter that scope, to avoid finding member functions of the
7610 current class with same name. */
7611 push_nested_namespace (ns);
7612 fns = tsubst_expr (DECL_TI_TEMPLATE (decl), args,
7613 tf_warning_or_error, NULL_TREE,
7614 /*integral_constant_expression_p=*/false);
7615 pop_nested_namespace (ns);
7616 arglist = tsubst (DECL_TI_ARGS (decl), args,
7617 tf_warning_or_error, NULL_TREE);
7618 template_id = lookup_template_function (fns, arglist);
7620 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
7621 tmpl = determine_specialization (template_id, new_friend,
7623 /*need_member_template=*/0,
7624 TREE_VEC_LENGTH (args),
7626 return instantiate_template (tmpl, new_args, tf_error);
7629 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
7631 /* The NEW_FRIEND will look like an instantiation, to the
7632 compiler, but is not an instantiation from the point of view of
7633 the language. For example, we might have had:
7635 template <class T> struct S {
7636 template <class U> friend void f(T, U);
7639 Then, in S<int>, template <class U> void f(int, U) is not an
7640 instantiation of anything. */
7641 if (new_friend == error_mark_node)
7642 return error_mark_node;
7644 DECL_USE_TEMPLATE (new_friend) = 0;
7645 if (TREE_CODE (decl) == TEMPLATE_DECL)
7647 DECL_USE_TEMPLATE (DECL_TEMPLATE_RESULT (new_friend)) = 0;
7648 DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (new_friend))
7649 = DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (decl));
7652 /* The mangled name for the NEW_FRIEND is incorrect. The function
7653 is not a template instantiation and should not be mangled like
7654 one. Therefore, we forget the mangling here; we'll recompute it
7655 later if we need it. */
7656 if (TREE_CODE (new_friend) != TEMPLATE_DECL)
7658 SET_DECL_RTL (new_friend, NULL);
7659 SET_DECL_ASSEMBLER_NAME (new_friend, NULL_TREE);
7662 if (DECL_NAMESPACE_SCOPE_P (new_friend))
7665 tree new_friend_template_info;
7666 tree new_friend_result_template_info;
7668 int new_friend_is_defn;
7670 /* We must save some information from NEW_FRIEND before calling
7671 duplicate decls since that function will free NEW_FRIEND if
7673 new_friend_template_info = DECL_TEMPLATE_INFO (new_friend);
7674 new_friend_is_defn =
7675 (DECL_INITIAL (DECL_TEMPLATE_RESULT
7676 (template_for_substitution (new_friend)))
7678 if (TREE_CODE (new_friend) == TEMPLATE_DECL)
7680 /* This declaration is a `primary' template. */
7681 DECL_PRIMARY_TEMPLATE (new_friend) = new_friend;
7683 new_friend_result_template_info
7684 = DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (new_friend));
7687 new_friend_result_template_info = NULL_TREE;
7689 /* Make the init_value nonzero so pushdecl knows this is a defn. */
7690 if (new_friend_is_defn)
7691 DECL_INITIAL (new_friend) = error_mark_node;
7693 /* Inside pushdecl_namespace_level, we will push into the
7694 current namespace. However, the friend function should go
7695 into the namespace of the template. */
7696 ns = decl_namespace_context (new_friend);
7697 push_nested_namespace (ns);
7698 old_decl = pushdecl_namespace_level (new_friend, /*is_friend=*/true);
7699 pop_nested_namespace (ns);
7701 if (old_decl == error_mark_node)
7702 return error_mark_node;
7704 if (old_decl != new_friend)
7706 /* This new friend declaration matched an existing
7707 declaration. For example, given:
7709 template <class T> void f(T);
7710 template <class U> class C {
7711 template <class T> friend void f(T) {}
7714 the friend declaration actually provides the definition
7715 of `f', once C has been instantiated for some type. So,
7716 old_decl will be the out-of-class template declaration,
7717 while new_friend is the in-class definition.
7719 But, if `f' was called before this point, the
7720 instantiation of `f' will have DECL_TI_ARGS corresponding
7721 to `T' but not to `U', references to which might appear
7722 in the definition of `f'. Previously, the most general
7723 template for an instantiation of `f' was the out-of-class
7724 version; now it is the in-class version. Therefore, we
7725 run through all specialization of `f', adding to their
7726 DECL_TI_ARGS appropriately. In particular, they need a
7727 new set of outer arguments, corresponding to the
7728 arguments for this class instantiation.
7730 The same situation can arise with something like this:
7733 template <class T> class C {
7737 when `C<int>' is instantiated. Now, `f(int)' is defined
7740 if (!new_friend_is_defn)
7741 /* On the other hand, if the in-class declaration does
7742 *not* provide a definition, then we don't want to alter
7743 existing definitions. We can just leave everything
7748 tree new_template = TI_TEMPLATE (new_friend_template_info);
7749 tree new_args = TI_ARGS (new_friend_template_info);
7751 /* Overwrite whatever template info was there before, if
7752 any, with the new template information pertaining to
7754 DECL_TEMPLATE_INFO (old_decl) = new_friend_template_info;
7756 if (TREE_CODE (old_decl) != TEMPLATE_DECL)
7758 /* We should have called reregister_specialization in
7760 gcc_assert (retrieve_specialization (new_template,
7764 /* Instantiate it if the global has already been used. */
7765 if (DECL_ODR_USED (old_decl))
7766 instantiate_decl (old_decl, /*defer_ok=*/true,
7767 /*expl_inst_class_mem_p=*/false);
7773 /* Indicate that the old function template is a partial
7775 DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (old_decl))
7776 = new_friend_result_template_info;
7778 gcc_assert (new_template
7779 == most_general_template (new_template));
7780 gcc_assert (new_template != old_decl);
7782 /* Reassign any specializations already in the hash table
7783 to the new more general template, and add the
7784 additional template args. */
7785 for (t = DECL_TEMPLATE_INSTANTIATIONS (old_decl);
7789 tree spec = TREE_VALUE (t);
7792 elt.tmpl = old_decl;
7793 elt.args = DECL_TI_ARGS (spec);
7794 elt.spec = NULL_TREE;
7796 htab_remove_elt (decl_specializations, &elt);
7799 = add_outermost_template_args (new_args,
7800 DECL_TI_ARGS (spec));
7802 register_specialization
7803 (spec, new_template, DECL_TI_ARGS (spec), true, 0);
7806 DECL_TEMPLATE_INSTANTIATIONS (old_decl) = NULL_TREE;
7810 /* The information from NEW_FRIEND has been merged into OLD_DECL
7811 by duplicate_decls. */
7812 new_friend = old_decl;
7817 tree context = DECL_CONTEXT (new_friend);
7821 template <class T> class C {
7822 template <class U> friend void C1<U>::f (); // case 1
7823 friend void C2<T>::f (); // case 2
7825 we only need to make sure CONTEXT is a complete type for
7826 case 2. To distinguish between the two cases, we note that
7827 CONTEXT of case 1 remains dependent type after tsubst while
7828 this isn't true for case 2. */
7829 ++processing_template_decl;
7830 dependent_p = dependent_type_p (context);
7831 --processing_template_decl;
7834 && !complete_type_or_else (context, NULL_TREE))
7835 return error_mark_node;
7837 if (COMPLETE_TYPE_P (context))
7839 /* Check to see that the declaration is really present, and,
7840 possibly obtain an improved declaration. */
7841 tree fn = check_classfn (context,
7842 new_friend, NULL_TREE);
7852 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
7853 template arguments, as for tsubst.
7855 Returns an appropriate tsubst'd friend type or error_mark_node on
7859 tsubst_friend_class (tree friend_tmpl, tree args)
7865 context = CP_DECL_CONTEXT (friend_tmpl);
7867 if (context != global_namespace)
7869 if (TREE_CODE (context) == NAMESPACE_DECL)
7870 push_nested_namespace (context);
7872 push_nested_class (tsubst (context, args, tf_none, NULL_TREE));
7875 /* Look for a class template declaration. We look for hidden names
7876 because two friend declarations of the same template are the
7877 same. For example, in:
7880 template <typename> friend class F;
7882 template <typename> struct B {
7883 template <typename> friend class F;
7886 both F templates are the same. */
7887 tmpl = lookup_name_real (DECL_NAME (friend_tmpl), 0, 0,
7888 /*block_p=*/true, 0,
7889 LOOKUP_COMPLAIN | LOOKUP_HIDDEN);
7891 /* But, if we don't find one, it might be because we're in a
7892 situation like this:
7900 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
7901 for `S<int>', not the TEMPLATE_DECL. */
7902 if (!tmpl || !DECL_CLASS_TEMPLATE_P (tmpl))
7904 tmpl = lookup_name_prefer_type (DECL_NAME (friend_tmpl), 1);
7905 tmpl = maybe_get_template_decl_from_type_decl (tmpl);
7908 if (tmpl && DECL_CLASS_TEMPLATE_P (tmpl))
7910 /* The friend template has already been declared. Just
7911 check to see that the declarations match, and install any new
7912 default parameters. We must tsubst the default parameters,
7913 of course. We only need the innermost template parameters
7914 because that is all that redeclare_class_template will look
7916 if (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (friend_tmpl))
7917 > TMPL_ARGS_DEPTH (args))
7920 location_t saved_input_location;
7921 parms = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_tmpl),
7922 args, tf_warning_or_error);
7924 saved_input_location = input_location;
7925 input_location = DECL_SOURCE_LOCATION (friend_tmpl);
7926 redeclare_class_template (TREE_TYPE (tmpl), parms);
7927 input_location = saved_input_location;
7931 friend_type = TREE_TYPE (tmpl);
7935 /* The friend template has not already been declared. In this
7936 case, the instantiation of the template class will cause the
7937 injection of this template into the global scope. */
7938 tmpl = tsubst (friend_tmpl, args, tf_warning_or_error, NULL_TREE);
7939 if (tmpl == error_mark_node)
7940 return error_mark_node;
7942 /* The new TMPL is not an instantiation of anything, so we
7943 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
7944 the new type because that is supposed to be the corresponding
7945 template decl, i.e., TMPL. */
7946 DECL_USE_TEMPLATE (tmpl) = 0;
7947 DECL_TEMPLATE_INFO (tmpl) = NULL_TREE;
7948 CLASSTYPE_USE_TEMPLATE (TREE_TYPE (tmpl)) = 0;
7949 CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl))
7950 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl)));
7952 /* Inject this template into the global scope. */
7953 friend_type = TREE_TYPE (pushdecl_top_level_maybe_friend (tmpl, true));
7956 if (context != global_namespace)
7958 if (TREE_CODE (context) == NAMESPACE_DECL)
7959 pop_nested_namespace (context);
7961 pop_nested_class ();
7967 /* Returns zero if TYPE cannot be completed later due to circularity.
7968 Otherwise returns one. */
7971 can_complete_type_without_circularity (tree type)
7973 if (type == NULL_TREE || type == error_mark_node)
7975 else if (COMPLETE_TYPE_P (type))
7977 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
7978 return can_complete_type_without_circularity (TREE_TYPE (type));
7979 else if (CLASS_TYPE_P (type)
7980 && TYPE_BEING_DEFINED (TYPE_MAIN_VARIANT (type)))
7986 /* Apply any attributes which had to be deferred until instantiation
7987 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
7988 ARGS, COMPLAIN, IN_DECL are as tsubst. */
7991 apply_late_template_attributes (tree *decl_p, tree attributes, int attr_flags,
7992 tree args, tsubst_flags_t complain, tree in_decl)
7994 tree last_dep = NULL_TREE;
7998 for (t = attributes; t; t = TREE_CHAIN (t))
7999 if (ATTR_IS_DEPENDENT (t))
8002 attributes = copy_list (attributes);
8006 if (DECL_P (*decl_p))
8008 if (TREE_TYPE (*decl_p) == error_mark_node)
8010 p = &DECL_ATTRIBUTES (*decl_p);
8013 p = &TYPE_ATTRIBUTES (*decl_p);
8017 tree late_attrs = NULL_TREE;
8018 tree *q = &late_attrs;
8020 for (*p = attributes; *p; )
8023 if (ATTR_IS_DEPENDENT (t))
8025 *p = TREE_CHAIN (t);
8026 TREE_CHAIN (t) = NULL_TREE;
8027 /* If the first attribute argument is an identifier, don't
8028 pass it through tsubst. Attributes like mode, format,
8029 cleanup and several target specific attributes expect it
8032 && TREE_CODE (TREE_VALUE (t)) == TREE_LIST
8033 && TREE_VALUE (TREE_VALUE (t))
8034 && (TREE_CODE (TREE_VALUE (TREE_VALUE (t)))
8035 == IDENTIFIER_NODE))
8038 = tsubst_expr (TREE_CHAIN (TREE_VALUE (t)), args, complain,
8040 /*integral_constant_expression_p=*/false);
8041 if (chain != TREE_CHAIN (TREE_VALUE (t)))
8043 = tree_cons (NULL_TREE, TREE_VALUE (TREE_VALUE (t)),
8048 = tsubst_expr (TREE_VALUE (t), args, complain, in_decl,
8049 /*integral_constant_expression_p=*/false);
8051 q = &TREE_CHAIN (t);
8054 p = &TREE_CHAIN (t);
8057 cplus_decl_attributes (decl_p, late_attrs, attr_flags);
8061 /* Perform (or defer) access check for typedefs that were referenced
8062 from within the template TMPL code.
8063 This is a subroutine of instantiate_template and instantiate_class_template.
8064 TMPL is the template to consider and TARGS is the list of arguments of
8068 perform_typedefs_access_check (tree tmpl, tree targs)
8070 location_t saved_location;
8072 qualified_typedef_usage_t *iter;
8075 || (!CLASS_TYPE_P (tmpl)
8076 && TREE_CODE (tmpl) != FUNCTION_DECL))
8079 saved_location = input_location;
8080 FOR_EACH_VEC_ELT (qualified_typedef_usage_t,
8081 get_types_needing_access_check (tmpl),
8084 tree type_decl = iter->typedef_decl;
8085 tree type_scope = iter->context;
8087 if (!type_decl || !type_scope || !CLASS_TYPE_P (type_scope))
8090 if (uses_template_parms (type_decl))
8091 type_decl = tsubst (type_decl, targs, tf_error, NULL_TREE);
8092 if (uses_template_parms (type_scope))
8093 type_scope = tsubst (type_scope, targs, tf_error, NULL_TREE);
8095 /* Make access check error messages point to the location
8096 of the use of the typedef. */
8097 input_location = iter->locus;
8098 perform_or_defer_access_check (TYPE_BINFO (type_scope),
8099 type_decl, type_decl);
8101 input_location = saved_location;
8105 instantiate_class_template (tree type)
8107 tree templ, args, pattern, t, member;
8111 unsigned int saved_maximum_field_alignment;
8113 if (type == error_mark_node)
8114 return error_mark_node;
8116 if (COMPLETE_OR_OPEN_TYPE_P (type)
8117 || uses_template_parms (type))
8120 /* Figure out which template is being instantiated. */
8121 templ = most_general_template (CLASSTYPE_TI_TEMPLATE (type));
8122 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
8124 /* Determine what specialization of the original template to
8126 t = most_specialized_class (type, templ, tf_warning_or_error);
8127 if (t == error_mark_node)
8129 TYPE_BEING_DEFINED (type) = 1;
8130 return error_mark_node;
8134 /* This TYPE is actually an instantiation of a partial
8135 specialization. We replace the innermost set of ARGS with
8136 the arguments appropriate for substitution. For example,
8139 template <class T> struct S {};
8140 template <class T> struct S<T*> {};
8142 and supposing that we are instantiating S<int*>, ARGS will
8143 presently be {int*} -- but we need {int}. */
8144 pattern = TREE_TYPE (t);
8145 args = TREE_PURPOSE (t);
8149 pattern = TREE_TYPE (templ);
8150 args = CLASSTYPE_TI_ARGS (type);
8153 /* If the template we're instantiating is incomplete, then clearly
8154 there's nothing we can do. */
8155 if (!COMPLETE_TYPE_P (pattern))
8158 /* If we've recursively instantiated too many templates, stop. */
8159 if (! push_tinst_level (type))
8162 /* Now we're really doing the instantiation. Mark the type as in
8163 the process of being defined. */
8164 TYPE_BEING_DEFINED (type) = 1;
8166 /* We may be in the middle of deferred access check. Disable
8168 push_deferring_access_checks (dk_no_deferred);
8170 push_to_top_level ();
8171 /* Use #pragma pack from the template context. */
8172 saved_maximum_field_alignment = maximum_field_alignment;
8173 maximum_field_alignment = TYPE_PRECISION (pattern);
8175 SET_CLASSTYPE_INTERFACE_UNKNOWN (type);
8177 /* Set the input location to the most specialized template definition.
8178 This is needed if tsubsting causes an error. */
8179 typedecl = TYPE_MAIN_DECL (pattern);
8180 input_location = DECL_SOURCE_LOCATION (TYPE_NAME (type)) =
8181 DECL_SOURCE_LOCATION (typedecl);
8183 TYPE_HAS_USER_CONSTRUCTOR (type) = TYPE_HAS_USER_CONSTRUCTOR (pattern);
8184 TYPE_HAS_NEW_OPERATOR (type) = TYPE_HAS_NEW_OPERATOR (pattern);
8185 TYPE_HAS_ARRAY_NEW_OPERATOR (type) = TYPE_HAS_ARRAY_NEW_OPERATOR (pattern);
8186 TYPE_GETS_DELETE (type) = TYPE_GETS_DELETE (pattern);
8187 TYPE_HAS_COPY_ASSIGN (type) = TYPE_HAS_COPY_ASSIGN (pattern);
8188 TYPE_HAS_CONST_COPY_ASSIGN (type) = TYPE_HAS_CONST_COPY_ASSIGN (pattern);
8189 TYPE_HAS_COPY_CTOR (type) = TYPE_HAS_COPY_CTOR (pattern);
8190 TYPE_HAS_CONST_COPY_CTOR (type) = TYPE_HAS_CONST_COPY_CTOR (pattern);
8191 TYPE_HAS_DEFAULT_CONSTRUCTOR (type) = TYPE_HAS_DEFAULT_CONSTRUCTOR (pattern);
8192 TYPE_HAS_CONVERSION (type) = TYPE_HAS_CONVERSION (pattern);
8193 TYPE_PACKED (type) = TYPE_PACKED (pattern);
8194 TYPE_ALIGN (type) = TYPE_ALIGN (pattern);
8195 TYPE_USER_ALIGN (type) = TYPE_USER_ALIGN (pattern);
8196 TYPE_FOR_JAVA (type) = TYPE_FOR_JAVA (pattern); /* For libjava's JArray<T> */
8197 if (ANON_AGGR_TYPE_P (pattern))
8198 SET_ANON_AGGR_TYPE_P (type);
8199 if (CLASSTYPE_VISIBILITY_SPECIFIED (pattern))
8201 CLASSTYPE_VISIBILITY_SPECIFIED (type) = 1;
8202 CLASSTYPE_VISIBILITY (type) = CLASSTYPE_VISIBILITY (pattern);
8205 pbinfo = TYPE_BINFO (pattern);
8207 /* We should never instantiate a nested class before its enclosing
8208 class; we need to look up the nested class by name before we can
8209 instantiate it, and that lookup should instantiate the enclosing
8211 gcc_assert (!DECL_CLASS_SCOPE_P (TYPE_MAIN_DECL (pattern))
8212 || COMPLETE_OR_OPEN_TYPE_P (TYPE_CONTEXT (type)));
8214 base_list = NULL_TREE;
8215 if (BINFO_N_BASE_BINFOS (pbinfo))
8221 /* We must enter the scope containing the type, as that is where
8222 the accessibility of types named in dependent bases are
8224 pushed_scope = push_scope (CP_TYPE_CONTEXT (type));
8226 /* Substitute into each of the bases to determine the actual
8228 for (i = 0; BINFO_BASE_ITERATE (pbinfo, i, pbase_binfo); i++)
8231 tree access = BINFO_BASE_ACCESS (pbinfo, i);
8232 tree expanded_bases = NULL_TREE;
8235 if (PACK_EXPANSION_P (BINFO_TYPE (pbase_binfo)))
8238 tsubst_pack_expansion (BINFO_TYPE (pbase_binfo),
8239 args, tf_error, NULL_TREE);
8240 if (expanded_bases == error_mark_node)
8243 len = TREE_VEC_LENGTH (expanded_bases);
8246 for (idx = 0; idx < len; idx++)
8249 /* Extract the already-expanded base class. */
8250 base = TREE_VEC_ELT (expanded_bases, idx);
8252 /* Substitute to figure out the base class. */
8253 base = tsubst (BINFO_TYPE (pbase_binfo), args, tf_error,
8256 if (base == error_mark_node)
8259 base_list = tree_cons (access, base, base_list);
8260 if (BINFO_VIRTUAL_P (pbase_binfo))
8261 TREE_TYPE (base_list) = integer_type_node;
8265 /* The list is now in reverse order; correct that. */
8266 base_list = nreverse (base_list);
8269 pop_scope (pushed_scope);
8271 /* Now call xref_basetypes to set up all the base-class
8273 xref_basetypes (type, base_list);
8275 apply_late_template_attributes (&type, TYPE_ATTRIBUTES (pattern),
8276 (int) ATTR_FLAG_TYPE_IN_PLACE,
8277 args, tf_error, NULL_TREE);
8278 fixup_attribute_variants (type);
8280 /* Now that our base classes are set up, enter the scope of the
8281 class, so that name lookups into base classes, etc. will work
8282 correctly. This is precisely analogous to what we do in
8283 begin_class_definition when defining an ordinary non-template
8284 class, except we also need to push the enclosing classes. */
8285 push_nested_class (type);
8287 /* Now members are processed in the order of declaration. */
8288 for (member = CLASSTYPE_DECL_LIST (pattern);
8289 member; member = TREE_CHAIN (member))
8291 tree t = TREE_VALUE (member);
8293 if (TREE_PURPOSE (member))
8297 /* Build new CLASSTYPE_NESTED_UTDS. */
8300 bool class_template_p;
8302 class_template_p = (TREE_CODE (t) != ENUMERAL_TYPE
8303 && TYPE_LANG_SPECIFIC (t)
8304 && CLASSTYPE_IS_TEMPLATE (t));
8305 /* If the member is a class template, then -- even after
8306 substitution -- there may be dependent types in the
8307 template argument list for the class. We increment
8308 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
8309 that function will assume that no types are dependent
8310 when outside of a template. */
8311 if (class_template_p)
8312 ++processing_template_decl;
8313 newtag = tsubst (t, args, tf_error, NULL_TREE);
8314 if (class_template_p)
8315 --processing_template_decl;
8316 if (newtag == error_mark_node)
8319 if (TREE_CODE (newtag) != ENUMERAL_TYPE)
8321 tree name = TYPE_IDENTIFIER (t);
8323 if (class_template_p)
8324 /* Unfortunately, lookup_template_class sets
8325 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
8326 instantiation (i.e., for the type of a member
8327 template class nested within a template class.)
8328 This behavior is required for
8329 maybe_process_partial_specialization to work
8330 correctly, but is not accurate in this case;
8331 the TAG is not an instantiation of anything.
8332 (The corresponding TEMPLATE_DECL is an
8333 instantiation, but the TYPE is not.) */
8334 CLASSTYPE_USE_TEMPLATE (newtag) = 0;
8336 /* Now, we call pushtag to put this NEWTAG into the scope of
8337 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
8338 pushtag calling push_template_decl. We don't have to do
8339 this for enums because it will already have been done in
8342 SET_IDENTIFIER_TYPE_VALUE (name, newtag);
8343 pushtag (name, newtag, /*tag_scope=*/ts_current);
8346 else if (TREE_CODE (t) == FUNCTION_DECL
8347 || DECL_FUNCTION_TEMPLATE_P (t))
8349 /* Build new TYPE_METHODS. */
8352 if (TREE_CODE (t) == TEMPLATE_DECL)
8353 ++processing_template_decl;
8354 r = tsubst (t, args, tf_error, NULL_TREE);
8355 if (TREE_CODE (t) == TEMPLATE_DECL)
8356 --processing_template_decl;
8357 set_current_access_from_decl (r);
8358 finish_member_declaration (r);
8362 /* Build new TYPE_FIELDS. */
8363 if (TREE_CODE (t) == STATIC_ASSERT)
8366 tsubst_expr (STATIC_ASSERT_CONDITION (t), args,
8367 tf_warning_or_error, NULL_TREE,
8368 /*integral_constant_expression_p=*/true);
8369 finish_static_assert (condition,
8370 STATIC_ASSERT_MESSAGE (t),
8371 STATIC_ASSERT_SOURCE_LOCATION (t),
8374 else if (TREE_CODE (t) != CONST_DECL)
8378 /* The file and line for this declaration, to
8379 assist in error message reporting. Since we
8380 called push_tinst_level above, we don't need to
8382 input_location = DECL_SOURCE_LOCATION (t);
8384 if (TREE_CODE (t) == TEMPLATE_DECL)
8385 ++processing_template_decl;
8386 r = tsubst (t, args, tf_warning_or_error, NULL_TREE);
8387 if (TREE_CODE (t) == TEMPLATE_DECL)
8388 --processing_template_decl;
8389 if (TREE_CODE (r) == VAR_DECL)
8393 [t]he initialization (and any associated
8394 side-effects) of a static data member does
8395 not occur unless the static data member is
8396 itself used in a way that requires the
8397 definition of the static data member to
8400 Therefore, we do not substitute into the
8401 initialized for the static data member here. */
8402 finish_static_data_member_decl
8405 /*init_const_expr_p=*/false,
8406 /*asmspec_tree=*/NULL_TREE,
8408 if (DECL_INITIALIZED_IN_CLASS_P (r))
8409 check_static_variable_definition (r, TREE_TYPE (r));
8411 else if (TREE_CODE (r) == FIELD_DECL)
8413 /* Determine whether R has a valid type and can be
8414 completed later. If R is invalid, then it is
8415 replaced by error_mark_node so that it will not be
8416 added to TYPE_FIELDS. */
8417 tree rtype = TREE_TYPE (r);
8418 if (can_complete_type_without_circularity (rtype))
8419 complete_type (rtype);
8421 if (!COMPLETE_TYPE_P (rtype))
8423 cxx_incomplete_type_error (r, rtype);
8424 r = error_mark_node;
8428 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
8429 such a thing will already have been added to the field
8430 list by tsubst_enum in finish_member_declaration in the
8431 CLASSTYPE_NESTED_UTDS case above. */
8432 if (!(TREE_CODE (r) == TYPE_DECL
8433 && TREE_CODE (TREE_TYPE (r)) == ENUMERAL_TYPE
8434 && DECL_ARTIFICIAL (r)))
8436 set_current_access_from_decl (r);
8437 finish_member_declaration (r);
8444 if (TYPE_P (t) || DECL_CLASS_TEMPLATE_P (t))
8446 /* Build new CLASSTYPE_FRIEND_CLASSES. */
8448 tree friend_type = t;
8449 bool adjust_processing_template_decl = false;
8451 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
8453 /* template <class T> friend class C; */
8454 friend_type = tsubst_friend_class (friend_type, args);
8455 adjust_processing_template_decl = true;
8457 else if (TREE_CODE (friend_type) == UNBOUND_CLASS_TEMPLATE)
8459 /* template <class T> friend class C::D; */
8460 friend_type = tsubst (friend_type, args,
8461 tf_warning_or_error, NULL_TREE);
8462 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
8463 friend_type = TREE_TYPE (friend_type);
8464 adjust_processing_template_decl = true;
8466 else if (TREE_CODE (friend_type) == TYPENAME_TYPE)
8468 /* This could be either
8472 when dependent_type_p is false or
8474 template <class U> friend class T::C;
8477 friend_type = tsubst (friend_type, args,
8478 tf_warning_or_error, NULL_TREE);
8479 /* Bump processing_template_decl for correct
8480 dependent_type_p calculation. */
8481 ++processing_template_decl;
8482 if (dependent_type_p (friend_type))
8483 adjust_processing_template_decl = true;
8484 --processing_template_decl;
8486 else if (!CLASSTYPE_USE_TEMPLATE (friend_type)
8487 && hidden_name_p (TYPE_NAME (friend_type)))
8491 where C hasn't been declared yet. Let's lookup name
8492 from namespace scope directly, bypassing any name that
8493 come from dependent base class. */
8494 tree ns = decl_namespace_context (TYPE_MAIN_DECL (friend_type));
8496 /* The call to xref_tag_from_type does injection for friend
8498 push_nested_namespace (ns);
8500 xref_tag_from_type (friend_type, NULL_TREE,
8501 /*tag_scope=*/ts_current);
8502 pop_nested_namespace (ns);
8504 else if (uses_template_parms (friend_type))
8505 /* friend class C<T>; */
8506 friend_type = tsubst (friend_type, args,
8507 tf_warning_or_error, NULL_TREE);
8512 where C is already declared or
8514 friend class C<int>;
8516 We don't have to do anything in these cases. */
8518 if (adjust_processing_template_decl)
8519 /* Trick make_friend_class into realizing that the friend
8520 we're adding is a template, not an ordinary class. It's
8521 important that we use make_friend_class since it will
8522 perform some error-checking and output cross-reference
8524 ++processing_template_decl;
8526 if (friend_type != error_mark_node)
8527 make_friend_class (type, friend_type, /*complain=*/false);
8529 if (adjust_processing_template_decl)
8530 --processing_template_decl;
8534 /* Build new DECL_FRIENDLIST. */
8537 /* The file and line for this declaration, to
8538 assist in error message reporting. Since we
8539 called push_tinst_level above, we don't need to
8541 input_location = DECL_SOURCE_LOCATION (t);
8543 if (TREE_CODE (t) == TEMPLATE_DECL)
8545 ++processing_template_decl;
8546 push_deferring_access_checks (dk_no_check);
8549 r = tsubst_friend_function (t, args);
8550 add_friend (type, r, /*complain=*/false);
8551 if (TREE_CODE (t) == TEMPLATE_DECL)
8553 pop_deferring_access_checks ();
8554 --processing_template_decl;
8560 /* Set the file and line number information to whatever is given for
8561 the class itself. This puts error messages involving generated
8562 implicit functions at a predictable point, and the same point
8563 that would be used for non-template classes. */
8564 input_location = DECL_SOURCE_LOCATION (typedecl);
8566 unreverse_member_declarations (type);
8567 finish_struct_1 (type);
8568 TYPE_BEING_DEFINED (type) = 0;
8570 /* We don't instantiate default arguments for member functions. 14.7.1:
8572 The implicit instantiation of a class template specialization causes
8573 the implicit instantiation of the declarations, but not of the
8574 definitions or default arguments, of the class member functions,
8575 member classes, static data members and member templates.... */
8577 /* Some typedefs referenced from within the template code need to be access
8578 checked at template instantiation time, i.e now. These types were
8579 added to the template at parsing time. Let's get those and perform
8580 the access checks then. */
8581 perform_typedefs_access_check (pattern, args);
8582 perform_deferred_access_checks ();
8583 pop_nested_class ();
8584 maximum_field_alignment = saved_maximum_field_alignment;
8585 pop_from_top_level ();
8586 pop_deferring_access_checks ();
8589 /* The vtable for a template class can be emitted in any translation
8590 unit in which the class is instantiated. When there is no key
8591 method, however, finish_struct_1 will already have added TYPE to
8592 the keyed_classes list. */
8593 if (TYPE_CONTAINS_VPTR_P (type) && CLASSTYPE_KEY_METHOD (type))
8594 keyed_classes = tree_cons (NULL_TREE, type, keyed_classes);
8600 tsubst_template_arg (tree t, tree args, tsubst_flags_t complain, tree in_decl)
8606 else if (TYPE_P (t))
8607 r = tsubst (t, args, complain, in_decl);
8610 if (!(complain & tf_warning))
8611 ++c_inhibit_evaluation_warnings;
8612 r = tsubst_expr (t, args, complain, in_decl,
8613 /*integral_constant_expression_p=*/true);
8614 if (!(complain & tf_warning))
8615 --c_inhibit_evaluation_warnings;
8620 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
8621 NONTYPE_ARGUMENT_PACK. */
8624 make_fnparm_pack (tree spec_parm)
8626 /* Collect all of the extra "packed" parameters into an
8630 tree argpack = make_node (NONTYPE_ARGUMENT_PACK);
8631 tree argtypepack = cxx_make_type (TYPE_ARGUMENT_PACK);
8632 int i, len = list_length (spec_parm);
8634 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
8635 parmvec = make_tree_vec (len);
8636 parmtypevec = make_tree_vec (len);
8637 for (i = 0; i < len; i++, spec_parm = DECL_CHAIN (spec_parm))
8639 TREE_VEC_ELT (parmvec, i) = spec_parm;
8640 TREE_VEC_ELT (parmtypevec, i) = TREE_TYPE (spec_parm);
8643 /* Build the argument packs. */
8644 SET_ARGUMENT_PACK_ARGS (argpack, parmvec);
8645 SET_ARGUMENT_PACK_ARGS (argtypepack, parmtypevec);
8646 TREE_TYPE (argpack) = argtypepack;
8651 /* Substitute ARGS into T, which is an pack expansion
8652 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
8653 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
8654 (if only a partial substitution could be performed) or
8655 ERROR_MARK_NODE if there was an error. */
8657 tsubst_pack_expansion (tree t, tree args, tsubst_flags_t complain,
8661 tree pack, packs = NULL_TREE, unsubstituted_packs = NULL_TREE;
8665 htab_t saved_local_specializations = NULL;
8667 gcc_assert (PACK_EXPANSION_P (t));
8668 pattern = PACK_EXPANSION_PATTERN (t);
8670 /* Determine the argument packs that will instantiate the parameter
8671 packs used in the expansion expression. While we're at it,
8672 compute the number of arguments to be expanded and make sure it
8674 for (pack = PACK_EXPANSION_PARAMETER_PACKS (t); pack;
8675 pack = TREE_CHAIN (pack))
8677 tree parm_pack = TREE_VALUE (pack);
8678 tree arg_pack = NULL_TREE;
8679 tree orig_arg = NULL_TREE;
8681 if (TREE_CODE (parm_pack) == PARM_DECL)
8683 if (!cp_unevaluated_operand)
8684 arg_pack = retrieve_local_specialization (parm_pack);
8687 /* We can't rely on local_specializations for a parameter
8688 name used later in a function declaration (such as in a
8689 late-specified return type). Even if it exists, it might
8690 have the wrong value for a recursive call. Just make a
8691 dummy decl, since it's only used for its type. */
8692 arg_pack = tsubst_decl (parm_pack, args, complain);
8693 arg_pack = make_fnparm_pack (arg_pack);
8698 int level, idx, levels;
8699 template_parm_level_and_index (parm_pack, &level, &idx);
8701 levels = TMPL_ARGS_DEPTH (args);
8702 if (level <= levels)
8703 arg_pack = TMPL_ARG (args, level, idx);
8706 orig_arg = arg_pack;
8707 if (arg_pack && TREE_CODE (arg_pack) == ARGUMENT_PACK_SELECT)
8708 arg_pack = ARGUMENT_PACK_SELECT_FROM_PACK (arg_pack);
8710 if (arg_pack && !ARGUMENT_PACK_P (arg_pack))
8711 /* This can only happen if we forget to expand an argument
8712 pack somewhere else. Just return an error, silently. */
8714 result = make_tree_vec (1);
8715 TREE_VEC_ELT (result, 0) = error_mark_node;
8719 /* For clarity in the comments below let's use the
8720 representation 'argument_pack<elements>' to denote an
8721 argument pack and its elements.
8723 In the 'if' block below, we want to detect cases where
8724 ARG_PACK is argument_pack<PARM_PACK...>. I.e, we want to
8725 check if ARG_PACK is an argument pack which sole element is
8726 the expansion of PARM_PACK. That argument pack is typically
8727 created by template_parm_to_arg when passed a parameter
8730 && TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack)) == 1
8731 && PACK_EXPANSION_P (TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0)))
8733 tree expansion = TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0);
8734 tree pattern = PACK_EXPANSION_PATTERN (expansion);
8735 /* So we have an argument_pack<P...>. We want to test if P
8736 is actually PARM_PACK. We will not use cp_tree_equal to
8737 test P and PARM_PACK because during type fixup (by
8738 fixup_template_parm) P can be a pre-fixup version of a
8739 type and PARM_PACK be its post-fixup version.
8740 cp_tree_equal would consider them as different even
8741 though we would want to consider them compatible for our
8742 precise purpose here.
8744 Thus we are going to consider that P and PARM_PACK are
8745 compatible if they have the same DECL. */
8746 if ((/* If ARG_PACK is a type parameter pack named by the
8747 same DECL as parm_pack ... */
8749 && TYPE_P (parm_pack)
8750 && TYPE_NAME (pattern) == TYPE_NAME (parm_pack))
8751 /* ... or if ARG_PACK is a non-type parameter
8752 named by the same DECL as parm_pack ... */
8753 || (TREE_CODE (pattern) == TEMPLATE_PARM_INDEX
8754 && TREE_CODE (parm_pack) == PARM_DECL
8755 && TEMPLATE_PARM_DECL (pattern)
8756 == TEMPLATE_PARM_DECL (DECL_INITIAL (parm_pack))))
8757 && template_parameter_pack_p (pattern))
8758 /* ... then the argument pack that the parameter maps to
8759 is just an expansion of the parameter itself, such as
8760 one would find in the implicit typedef of a class
8761 inside the class itself. Consider this parameter
8762 "unsubstituted", so that we will maintain the outer
8764 arg_pack = NULL_TREE;
8770 TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack));
8772 /* It's all-or-nothing with incomplete argument packs. */
8773 if (incomplete && !ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
8774 return error_mark_node;
8776 if (ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
8781 else if (len != my_len)
8784 /* We got explicit args for some packs but not others;
8785 do nothing now and try again after deduction. */
8787 if (TREE_CODE (t) == TYPE_PACK_EXPANSION)
8788 error ("mismatched argument pack lengths while expanding "
8792 error ("mismatched argument pack lengths while expanding "
8795 return error_mark_node;
8798 /* Keep track of the parameter packs and their corresponding
8800 packs = tree_cons (parm_pack, arg_pack, packs);
8801 TREE_TYPE (packs) = orig_arg;
8804 /* We can't substitute for this parameter pack. */
8805 unsubstituted_packs = tree_cons (TREE_PURPOSE (pack),
8807 unsubstituted_packs);
8810 /* We cannot expand this expansion expression, because we don't have
8811 all of the argument packs we need. Substitute into the pattern
8812 and return a PACK_EXPANSION_*. The caller will need to deal with
8814 if (unsubstituted_packs)
8817 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
8818 new_pat = tsubst_expr (pattern, args, complain, in_decl,
8819 /*integral_constant_expression_p=*/false);
8821 new_pat = tsubst (pattern, args, complain, in_decl);
8822 return make_pack_expansion (new_pat);
8825 /* We could not find any argument packs that work. */
8827 return error_mark_node;
8829 if (cp_unevaluated_operand)
8831 /* We're in a late-specified return type, so create our own local
8832 specializations table; the current table is either NULL or (in the
8833 case of recursive unification) might have bindings that we don't
8834 want to use or alter. */
8835 saved_local_specializations = local_specializations;
8836 local_specializations = htab_create (37,
8837 hash_local_specialization,
8838 eq_local_specializations,
8842 /* For each argument in each argument pack, substitute into the
8844 result = make_tree_vec (len + incomplete);
8845 for (i = 0; i < len + incomplete; ++i)
8847 /* For parameter pack, change the substitution of the parameter
8848 pack to the ith argument in its argument pack, then expand
8850 for (pack = packs; pack; pack = TREE_CHAIN (pack))
8852 tree parm = TREE_PURPOSE (pack);
8854 if (TREE_CODE (parm) == PARM_DECL)
8856 /* Select the Ith argument from the pack. */
8857 tree arg = make_node (ARGUMENT_PACK_SELECT);
8858 ARGUMENT_PACK_SELECT_FROM_PACK (arg) = TREE_VALUE (pack);
8859 ARGUMENT_PACK_SELECT_INDEX (arg) = i;
8861 register_local_specialization (arg, parm);
8867 template_parm_level_and_index (parm, &level, &idx);
8871 /* Select the Ith argument from the pack. */
8872 value = make_node (ARGUMENT_PACK_SELECT);
8873 ARGUMENT_PACK_SELECT_FROM_PACK (value) = TREE_VALUE (pack);
8874 ARGUMENT_PACK_SELECT_INDEX (value) = i;
8877 /* Update the corresponding argument. */
8878 TMPL_ARG (args, level, idx) = value;
8882 /* Substitute into the PATTERN with the altered arguments. */
8883 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
8884 TREE_VEC_ELT (result, i) =
8885 tsubst_expr (pattern, args, complain, in_decl,
8886 /*integral_constant_expression_p=*/false);
8888 TREE_VEC_ELT (result, i) = tsubst (pattern, args, complain, in_decl);
8891 /* When we have incomplete argument packs, the last "expanded"
8892 result is itself a pack expansion, which allows us
8893 to deduce more arguments. */
8894 TREE_VEC_ELT (result, i) =
8895 make_pack_expansion (TREE_VEC_ELT (result, i));
8897 if (TREE_VEC_ELT (result, i) == error_mark_node)
8899 result = error_mark_node;
8904 /* Update ARGS to restore the substitution from parameter packs to
8905 their argument packs. */
8906 for (pack = packs; pack; pack = TREE_CHAIN (pack))
8908 tree parm = TREE_PURPOSE (pack);
8910 if (TREE_CODE (parm) == PARM_DECL)
8911 register_local_specialization (TREE_TYPE (pack), parm);
8915 template_parm_level_and_index (parm, &level, &idx);
8917 /* Update the corresponding argument. */
8918 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
8919 TREE_VEC_ELT (TREE_VEC_ELT (args, level -1 ), idx) =
8922 TREE_VEC_ELT (args, idx) = TREE_TYPE (pack);
8926 if (saved_local_specializations)
8928 htab_delete (local_specializations);
8929 local_specializations = saved_local_specializations;
8935 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
8936 TMPL. We do this using DECL_PARM_INDEX, which should work even with
8937 parameter packs; all parms generated from a function parameter pack will
8938 have the same DECL_PARM_INDEX. */
8941 get_pattern_parm (tree parm, tree tmpl)
8943 tree pattern = DECL_TEMPLATE_RESULT (tmpl);
8946 if (DECL_ARTIFICIAL (parm))
8948 for (patparm = DECL_ARGUMENTS (pattern);
8949 patparm; patparm = DECL_CHAIN (patparm))
8950 if (DECL_ARTIFICIAL (patparm)
8951 && DECL_NAME (parm) == DECL_NAME (patparm))
8956 patparm = FUNCTION_FIRST_USER_PARM (DECL_TEMPLATE_RESULT (tmpl));
8957 patparm = chain_index (DECL_PARM_INDEX (parm)-1, patparm);
8958 gcc_assert (DECL_PARM_INDEX (patparm)
8959 == DECL_PARM_INDEX (parm));
8965 /* Substitute ARGS into the vector or list of template arguments T. */
8968 tsubst_template_args (tree t, tree args, tsubst_flags_t complain, tree in_decl)
8971 int len, need_new = 0, i, expanded_len_adjust = 0, out;
8974 if (t == error_mark_node)
8975 return error_mark_node;
8977 len = TREE_VEC_LENGTH (t);
8978 elts = XALLOCAVEC (tree, len);
8980 for (i = 0; i < len; i++)
8982 tree orig_arg = TREE_VEC_ELT (t, i);
8985 if (TREE_CODE (orig_arg) == TREE_VEC)
8986 new_arg = tsubst_template_args (orig_arg, args, complain, in_decl);
8987 else if (PACK_EXPANSION_P (orig_arg))
8989 /* Substitute into an expansion expression. */
8990 new_arg = tsubst_pack_expansion (orig_arg, args, complain, in_decl);
8992 if (TREE_CODE (new_arg) == TREE_VEC)
8993 /* Add to the expanded length adjustment the number of
8994 expanded arguments. We subtract one from this
8995 measurement, because the argument pack expression
8996 itself is already counted as 1 in
8997 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
8998 the argument pack is empty. */
8999 expanded_len_adjust += TREE_VEC_LENGTH (new_arg) - 1;
9001 else if (ARGUMENT_PACK_P (orig_arg))
9003 /* Substitute into each of the arguments. */
9004 new_arg = TYPE_P (orig_arg)
9005 ? cxx_make_type (TREE_CODE (orig_arg))
9006 : make_node (TREE_CODE (orig_arg));
9008 SET_ARGUMENT_PACK_ARGS (
9010 tsubst_template_args (ARGUMENT_PACK_ARGS (orig_arg),
9011 args, complain, in_decl));
9013 if (ARGUMENT_PACK_ARGS (new_arg) == error_mark_node)
9014 new_arg = error_mark_node;
9016 if (TREE_CODE (new_arg) == NONTYPE_ARGUMENT_PACK) {
9017 TREE_TYPE (new_arg) = tsubst (TREE_TYPE (orig_arg), args,
9019 TREE_CONSTANT (new_arg) = TREE_CONSTANT (orig_arg);
9021 if (TREE_TYPE (new_arg) == error_mark_node)
9022 new_arg = error_mark_node;
9026 new_arg = tsubst_template_arg (orig_arg, args, complain, in_decl);
9028 if (new_arg == error_mark_node)
9029 return error_mark_node;
9032 if (new_arg != orig_arg)
9039 /* Make space for the expanded arguments coming from template
9041 t = make_tree_vec (len + expanded_len_adjust);
9042 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
9043 arguments for a member template.
9044 In that case each TREE_VEC in ORIG_T represents a level of template
9045 arguments, and ORIG_T won't carry any non defaulted argument count.
9046 It will rather be the nested TREE_VECs that will carry one.
9047 In other words, ORIG_T carries a non defaulted argument count only
9048 if it doesn't contain any nested TREE_VEC. */
9049 if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t))
9051 int count = GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t);
9052 count += expanded_len_adjust;
9053 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (t, count);
9055 for (i = 0, out = 0; i < len; i++)
9057 if ((PACK_EXPANSION_P (TREE_VEC_ELT (orig_t, i))
9058 || ARGUMENT_PACK_P (TREE_VEC_ELT (orig_t, i)))
9059 && TREE_CODE (elts[i]) == TREE_VEC)
9063 /* Now expand the template argument pack "in place". */
9064 for (idx = 0; idx < TREE_VEC_LENGTH (elts[i]); idx++, out++)
9065 TREE_VEC_ELT (t, out) = TREE_VEC_ELT (elts[i], idx);
9069 TREE_VEC_ELT (t, out) = elts[i];
9077 /* Return the result of substituting ARGS into the template parameters
9078 given by PARMS. If there are m levels of ARGS and m + n levels of
9079 PARMS, then the result will contain n levels of PARMS. For
9080 example, if PARMS is `template <class T> template <class U>
9081 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
9082 result will be `template <int*, double, class V>'. */
9085 tsubst_template_parms (tree parms, tree args, tsubst_flags_t complain)
9090 /* When substituting into a template, we must set
9091 PROCESSING_TEMPLATE_DECL as the template parameters may be
9092 dependent if they are based on one-another, and the dependency
9093 predicates are short-circuit outside of templates. */
9094 ++processing_template_decl;
9096 for (new_parms = &r;
9097 TMPL_PARMS_DEPTH (parms) > TMPL_ARGS_DEPTH (args);
9098 new_parms = &(TREE_CHAIN (*new_parms)),
9099 parms = TREE_CHAIN (parms))
9102 make_tree_vec (TREE_VEC_LENGTH (TREE_VALUE (parms)));
9105 for (i = 0; i < TREE_VEC_LENGTH (new_vec); ++i)
9109 if (parms == error_mark_node)
9112 tuple = TREE_VEC_ELT (TREE_VALUE (parms), i);
9114 if (tuple == error_mark_node)
9117 TREE_VEC_ELT (new_vec, i) =
9118 tsubst_template_parm (tuple, args, complain);
9122 tree_cons (size_int (TMPL_PARMS_DEPTH (parms)
9123 - TMPL_ARGS_DEPTH (args)),
9124 new_vec, NULL_TREE);
9127 --processing_template_decl;
9132 /* Return the result of substituting ARGS into one template parameter
9133 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
9134 parameter and which TREE_PURPOSE is the default argument of the
9135 template parameter. */
9138 tsubst_template_parm (tree t, tree args, tsubst_flags_t complain)
9140 tree default_value, parm_decl;
9142 if (args == NULL_TREE
9144 || t == error_mark_node)
9147 gcc_assert (TREE_CODE (t) == TREE_LIST);
9149 default_value = TREE_PURPOSE (t);
9150 parm_decl = TREE_VALUE (t);
9152 parm_decl = tsubst (parm_decl, args, complain, NULL_TREE);
9153 if (TREE_CODE (parm_decl) == PARM_DECL
9154 && invalid_nontype_parm_type_p (TREE_TYPE (parm_decl), complain))
9155 parm_decl = error_mark_node;
9156 default_value = tsubst_template_arg (default_value, args,
9157 complain, NULL_TREE);
9159 return build_tree_list (default_value, parm_decl);
9162 /* Substitute the ARGS into the indicated aggregate (or enumeration)
9163 type T. If T is not an aggregate or enumeration type, it is
9164 handled as if by tsubst. IN_DECL is as for tsubst. If
9165 ENTERING_SCOPE is nonzero, T is the context for a template which
9166 we are presently tsubst'ing. Return the substituted value. */
9169 tsubst_aggr_type (tree t,
9171 tsubst_flags_t complain,
9178 switch (TREE_CODE (t))
9181 if (TYPE_PTRMEMFUNC_P (t))
9182 return tsubst (TYPE_PTRMEMFUNC_FN_TYPE (t), args, complain, in_decl);
9184 /* Else fall through. */
9187 if (TYPE_TEMPLATE_INFO (t) && uses_template_parms (t))
9192 int saved_unevaluated_operand;
9193 int saved_inhibit_evaluation_warnings;
9195 /* In "sizeof(X<I>)" we need to evaluate "I". */
9196 saved_unevaluated_operand = cp_unevaluated_operand;
9197 cp_unevaluated_operand = 0;
9198 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
9199 c_inhibit_evaluation_warnings = 0;
9201 /* First, determine the context for the type we are looking
9203 context = TYPE_CONTEXT (t);
9206 context = tsubst_aggr_type (context, args, complain,
9207 in_decl, /*entering_scope=*/1);
9208 /* If context is a nested class inside a class template,
9209 it may still need to be instantiated (c++/33959). */
9210 if (TYPE_P (context))
9211 context = complete_type (context);
9214 /* Then, figure out what arguments are appropriate for the
9215 type we are trying to find. For example, given:
9217 template <class T> struct S;
9218 template <class T, class U> void f(T, U) { S<U> su; }
9220 and supposing that we are instantiating f<int, double>,
9221 then our ARGS will be {int, double}, but, when looking up
9222 S we only want {double}. */
9223 argvec = tsubst_template_args (TYPE_TI_ARGS (t), args,
9225 if (argvec == error_mark_node)
9226 r = error_mark_node;
9229 r = lookup_template_class (t, argvec, in_decl, context,
9230 entering_scope, complain);
9231 r = cp_build_qualified_type_real (r, cp_type_quals (t), complain);
9234 cp_unevaluated_operand = saved_unevaluated_operand;
9235 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
9240 /* This is not a template type, so there's nothing to do. */
9244 return tsubst (t, args, complain, in_decl);
9248 /* Substitute into the default argument ARG (a default argument for
9249 FN), which has the indicated TYPE. */
9252 tsubst_default_argument (tree fn, tree type, tree arg)
9254 tree saved_class_ptr = NULL_TREE;
9255 tree saved_class_ref = NULL_TREE;
9257 /* This can happen in invalid code. */
9258 if (TREE_CODE (arg) == DEFAULT_ARG)
9261 /* This default argument came from a template. Instantiate the
9262 default argument here, not in tsubst. In the case of
9271 we must be careful to do name lookup in the scope of S<T>,
9272 rather than in the current class. */
9273 push_access_scope (fn);
9274 /* The "this" pointer is not valid in a default argument. */
9277 saved_class_ptr = current_class_ptr;
9278 cp_function_chain->x_current_class_ptr = NULL_TREE;
9279 saved_class_ref = current_class_ref;
9280 cp_function_chain->x_current_class_ref = NULL_TREE;
9283 push_deferring_access_checks(dk_no_deferred);
9284 /* The default argument expression may cause implicitly defined
9285 member functions to be synthesized, which will result in garbage
9286 collection. We must treat this situation as if we were within
9287 the body of function so as to avoid collecting live data on the
9290 arg = tsubst_expr (arg, DECL_TI_ARGS (fn),
9291 tf_warning_or_error, NULL_TREE,
9292 /*integral_constant_expression_p=*/false);
9294 pop_deferring_access_checks();
9296 /* Restore the "this" pointer. */
9299 cp_function_chain->x_current_class_ptr = saved_class_ptr;
9300 cp_function_chain->x_current_class_ref = saved_class_ref;
9303 /* Make sure the default argument is reasonable. */
9304 arg = check_default_argument (type, arg);
9306 pop_access_scope (fn);
9311 /* Substitute into all the default arguments for FN. */
9314 tsubst_default_arguments (tree fn)
9319 tmpl_args = DECL_TI_ARGS (fn);
9321 /* If this function is not yet instantiated, we certainly don't need
9322 its default arguments. */
9323 if (uses_template_parms (tmpl_args))
9325 /* Don't do this again for clones. */
9326 if (DECL_CLONED_FUNCTION_P (fn))
9329 for (arg = TYPE_ARG_TYPES (TREE_TYPE (fn));
9331 arg = TREE_CHAIN (arg))
9332 if (TREE_PURPOSE (arg))
9333 TREE_PURPOSE (arg) = tsubst_default_argument (fn,
9335 TREE_PURPOSE (arg));
9338 /* Substitute the ARGS into the T, which is a _DECL. Return the
9339 result of the substitution. Issue error and warning messages under
9340 control of COMPLAIN. */
9343 tsubst_decl (tree t, tree args, tsubst_flags_t complain)
9345 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
9346 location_t saved_loc;
9351 /* Set the filename and linenumber to improve error-reporting. */
9352 saved_loc = input_location;
9353 input_location = DECL_SOURCE_LOCATION (t);
9355 switch (TREE_CODE (t))
9359 /* We can get here when processing a member function template,
9360 member class template, or template template parameter. */
9361 tree decl = DECL_TEMPLATE_RESULT (t);
9366 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
9368 /* Template template parameter is treated here. */
9369 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9370 if (new_type == error_mark_node)
9371 RETURN (error_mark_node);
9374 DECL_CHAIN (r) = NULL_TREE;
9375 TREE_TYPE (r) = new_type;
9376 DECL_TEMPLATE_RESULT (r)
9377 = build_decl (DECL_SOURCE_LOCATION (decl),
9378 TYPE_DECL, DECL_NAME (decl), new_type);
9379 DECL_TEMPLATE_PARMS (r)
9380 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
9382 TYPE_NAME (new_type) = r;
9386 /* We might already have an instance of this template.
9387 The ARGS are for the surrounding class type, so the
9388 full args contain the tsubst'd args for the context,
9389 plus the innermost args from the template decl. */
9390 tmpl_args = DECL_CLASS_TEMPLATE_P (t)
9391 ? CLASSTYPE_TI_ARGS (TREE_TYPE (t))
9392 : DECL_TI_ARGS (DECL_TEMPLATE_RESULT (t));
9393 /* Because this is a template, the arguments will still be
9394 dependent, even after substitution. If
9395 PROCESSING_TEMPLATE_DECL is not set, the dependency
9396 predicates will short-circuit. */
9397 ++processing_template_decl;
9398 full_args = tsubst_template_args (tmpl_args, args,
9400 --processing_template_decl;
9401 if (full_args == error_mark_node)
9402 RETURN (error_mark_node);
9404 /* If this is a default template template argument,
9405 tsubst might not have changed anything. */
9406 if (full_args == tmpl_args)
9409 hash = hash_tmpl_and_args (t, full_args);
9410 spec = retrieve_specialization (t, full_args, hash);
9411 if (spec != NULL_TREE)
9417 /* Make a new template decl. It will be similar to the
9418 original, but will record the current template arguments.
9419 We also create a new function declaration, which is just
9420 like the old one, but points to this new template, rather
9421 than the old one. */
9423 gcc_assert (DECL_LANG_SPECIFIC (r) != 0);
9424 DECL_CHAIN (r) = NULL_TREE;
9426 DECL_TEMPLATE_INFO (r) = build_template_info (t, args);
9428 if (TREE_CODE (decl) == TYPE_DECL)
9431 ++processing_template_decl;
9432 new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9433 --processing_template_decl;
9434 if (new_type == error_mark_node)
9435 RETURN (error_mark_node);
9437 TREE_TYPE (r) = new_type;
9438 CLASSTYPE_TI_TEMPLATE (new_type) = r;
9439 DECL_TEMPLATE_RESULT (r) = TYPE_MAIN_DECL (new_type);
9440 DECL_TI_ARGS (r) = CLASSTYPE_TI_ARGS (new_type);
9441 DECL_CONTEXT (r) = TYPE_CONTEXT (new_type);
9446 ++processing_template_decl;
9447 new_decl = tsubst (decl, args, complain, in_decl);
9448 --processing_template_decl;
9449 if (new_decl == error_mark_node)
9450 RETURN (error_mark_node);
9452 DECL_TEMPLATE_RESULT (r) = new_decl;
9453 DECL_TI_TEMPLATE (new_decl) = r;
9454 TREE_TYPE (r) = TREE_TYPE (new_decl);
9455 DECL_TI_ARGS (r) = DECL_TI_ARGS (new_decl);
9456 DECL_CONTEXT (r) = DECL_CONTEXT (new_decl);
9459 SET_DECL_IMPLICIT_INSTANTIATION (r);
9460 DECL_TEMPLATE_INSTANTIATIONS (r) = NULL_TREE;
9461 DECL_TEMPLATE_SPECIALIZATIONS (r) = NULL_TREE;
9463 /* The template parameters for this new template are all the
9464 template parameters for the old template, except the
9465 outermost level of parameters. */
9466 DECL_TEMPLATE_PARMS (r)
9467 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
9470 if (PRIMARY_TEMPLATE_P (t))
9471 DECL_PRIMARY_TEMPLATE (r) = r;
9473 if (TREE_CODE (decl) != TYPE_DECL)
9474 /* Record this non-type partial instantiation. */
9475 register_specialization (r, t,
9476 DECL_TI_ARGS (DECL_TEMPLATE_RESULT (r)),
9484 tree argvec = NULL_TREE;
9492 /* Nobody should be tsubst'ing into non-template functions. */
9493 gcc_assert (DECL_TEMPLATE_INFO (t) != NULL_TREE);
9495 if (TREE_CODE (DECL_TI_TEMPLATE (t)) == TEMPLATE_DECL)
9500 /* If T is not dependent, just return it. We have to
9501 increment PROCESSING_TEMPLATE_DECL because
9502 value_dependent_expression_p assumes that nothing is
9503 dependent when PROCESSING_TEMPLATE_DECL is zero. */
9504 ++processing_template_decl;
9505 dependent_p = value_dependent_expression_p (t);
9506 --processing_template_decl;
9510 /* Calculate the most general template of which R is a
9511 specialization, and the complete set of arguments used to
9513 gen_tmpl = most_general_template (DECL_TI_TEMPLATE (t));
9514 argvec = tsubst_template_args (DECL_TI_ARGS
9515 (DECL_TEMPLATE_RESULT
9516 (DECL_TI_TEMPLATE (t))),
9517 args, complain, in_decl);
9519 /* Check to see if we already have this specialization. */
9520 hash = hash_tmpl_and_args (gen_tmpl, argvec);
9521 spec = retrieve_specialization (gen_tmpl, argvec, hash);
9529 /* We can see more levels of arguments than parameters if
9530 there was a specialization of a member template, like
9533 template <class T> struct S { template <class U> void f(); }
9534 template <> template <class U> void S<int>::f(U);
9536 Here, we'll be substituting into the specialization,
9537 because that's where we can find the code we actually
9538 want to generate, but we'll have enough arguments for
9539 the most general template.
9541 We also deal with the peculiar case:
9543 template <class T> struct S {
9544 template <class U> friend void f();
9546 template <class U> void f() {}
9548 template void f<double>();
9550 Here, the ARGS for the instantiation of will be {int,
9551 double}. But, we only need as many ARGS as there are
9552 levels of template parameters in CODE_PATTERN. We are
9553 careful not to get fooled into reducing the ARGS in
9556 template <class T> struct S { template <class U> void f(U); }
9557 template <class T> template <> void S<T>::f(int) {}
9559 which we can spot because the pattern will be a
9560 specialization in this case. */
9561 args_depth = TMPL_ARGS_DEPTH (args);
9563 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (t)));
9564 if (args_depth > parms_depth
9565 && !DECL_TEMPLATE_SPECIALIZATION (t))
9566 args = get_innermost_template_args (args, parms_depth);
9570 /* This special case arises when we have something like this:
9572 template <class T> struct S {
9573 friend void f<int>(int, double);
9576 Here, the DECL_TI_TEMPLATE for the friend declaration
9577 will be an IDENTIFIER_NODE. We are being called from
9578 tsubst_friend_function, and we want only to create a
9579 new decl (R) with appropriate types so that we can call
9580 determine_specialization. */
9581 gen_tmpl = NULL_TREE;
9584 if (DECL_CLASS_SCOPE_P (t))
9586 if (DECL_NAME (t) == constructor_name (DECL_CONTEXT (t)))
9590 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args,
9591 complain, t, /*entering_scope=*/1);
9596 ctx = DECL_CONTEXT (t);
9598 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9599 if (type == error_mark_node)
9600 RETURN (error_mark_node);
9602 /* We do NOT check for matching decls pushed separately at this
9603 point, as they may not represent instantiations of this
9604 template, and in any case are considered separate under the
9607 DECL_USE_TEMPLATE (r) = 0;
9608 TREE_TYPE (r) = type;
9609 /* Clear out the mangled name and RTL for the instantiation. */
9610 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
9611 SET_DECL_RTL (r, NULL);
9612 /* Leave DECL_INITIAL set on deleted instantiations. */
9613 if (!DECL_DELETED_FN (r))
9614 DECL_INITIAL (r) = NULL_TREE;
9615 DECL_CONTEXT (r) = ctx;
9617 if (member && DECL_CONV_FN_P (r))
9618 /* Type-conversion operator. Reconstruct the name, in
9619 case it's the name of one of the template's parameters. */
9620 DECL_NAME (r) = mangle_conv_op_name_for_type (TREE_TYPE (type));
9622 DECL_ARGUMENTS (r) = tsubst (DECL_ARGUMENTS (t), args,
9624 DECL_RESULT (r) = NULL_TREE;
9626 TREE_STATIC (r) = 0;
9627 TREE_PUBLIC (r) = TREE_PUBLIC (t);
9628 DECL_EXTERNAL (r) = 1;
9629 /* If this is an instantiation of a function with internal
9630 linkage, we already know what object file linkage will be
9631 assigned to the instantiation. */
9632 DECL_INTERFACE_KNOWN (r) = !TREE_PUBLIC (r);
9633 DECL_DEFER_OUTPUT (r) = 0;
9634 DECL_CHAIN (r) = NULL_TREE;
9635 DECL_PENDING_INLINE_INFO (r) = 0;
9636 DECL_PENDING_INLINE_P (r) = 0;
9637 DECL_SAVED_TREE (r) = NULL_TREE;
9638 DECL_STRUCT_FUNCTION (r) = NULL;
9640 /* We'll re-clone as appropriate in instantiate_template. */
9641 DECL_CLONED_FUNCTION (r) = NULL_TREE;
9643 /* If we aren't complaining now, return on error before we register
9644 the specialization so that we'll complain eventually. */
9645 if ((complain & tf_error) == 0
9646 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
9647 && !grok_op_properties (r, /*complain=*/false))
9648 RETURN (error_mark_node);
9650 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
9651 this in the special friend case mentioned above where
9652 GEN_TMPL is NULL. */
9655 DECL_TEMPLATE_INFO (r)
9656 = build_template_info (gen_tmpl, argvec);
9657 SET_DECL_IMPLICIT_INSTANTIATION (r);
9658 register_specialization (r, gen_tmpl, argvec, false, hash);
9660 /* We're not supposed to instantiate default arguments
9661 until they are called, for a template. But, for a
9664 template <class T> void f ()
9665 { extern void g(int i = T()); }
9667 we should do the substitution when the template is
9668 instantiated. We handle the member function case in
9669 instantiate_class_template since the default arguments
9670 might refer to other members of the class. */
9672 && !PRIMARY_TEMPLATE_P (gen_tmpl)
9673 && !uses_template_parms (argvec))
9674 tsubst_default_arguments (r);
9677 DECL_TEMPLATE_INFO (r) = NULL_TREE;
9679 /* Copy the list of befriending classes. */
9680 for (friends = &DECL_BEFRIENDING_CLASSES (r);
9682 friends = &TREE_CHAIN (*friends))
9684 *friends = copy_node (*friends);
9685 TREE_VALUE (*friends) = tsubst (TREE_VALUE (*friends),
9690 if (DECL_CONSTRUCTOR_P (r) || DECL_DESTRUCTOR_P (r))
9692 maybe_retrofit_in_chrg (r);
9693 if (DECL_CONSTRUCTOR_P (r))
9694 grok_ctor_properties (ctx, r);
9695 /* If this is an instantiation of a member template, clone it.
9696 If it isn't, that'll be handled by
9697 clone_constructors_and_destructors. */
9698 if (PRIMARY_TEMPLATE_P (gen_tmpl))
9699 clone_function_decl (r, /*update_method_vec_p=*/0);
9701 else if ((complain & tf_error) != 0
9702 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
9703 && !grok_op_properties (r, /*complain=*/true))
9704 RETURN (error_mark_node);
9706 if (DECL_FRIEND_P (t) && DECL_FRIEND_CONTEXT (t))
9707 SET_DECL_FRIEND_CONTEXT (r,
9708 tsubst (DECL_FRIEND_CONTEXT (t),
9709 args, complain, in_decl));
9711 /* Possibly limit visibility based on template args. */
9712 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
9713 if (DECL_VISIBILITY_SPECIFIED (t))
9715 DECL_VISIBILITY_SPECIFIED (r) = 0;
9717 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
9719 determine_visibility (r);
9720 if (DECL_DEFAULTED_OUTSIDE_CLASS_P (r)
9721 && !processing_template_decl)
9722 defaulted_late_check (r);
9724 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
9725 args, complain, in_decl);
9731 tree type = NULL_TREE;
9733 tree expanded_types = NULL_TREE;
9734 tree prev_r = NULL_TREE;
9735 tree first_r = NULL_TREE;
9737 if (FUNCTION_PARAMETER_PACK_P (t))
9739 /* If there is a local specialization that isn't a
9740 parameter pack, it means that we're doing a "simple"
9741 substitution from inside tsubst_pack_expansion. Just
9742 return the local specialization (which will be a single
9744 tree spec = retrieve_local_specialization (t);
9746 && TREE_CODE (spec) == PARM_DECL
9747 && TREE_CODE (TREE_TYPE (spec)) != TYPE_PACK_EXPANSION)
9750 /* Expand the TYPE_PACK_EXPANSION that provides the types for
9751 the parameters in this function parameter pack. */
9752 expanded_types = tsubst_pack_expansion (TREE_TYPE (t), args,
9754 if (TREE_CODE (expanded_types) == TREE_VEC)
9756 len = TREE_VEC_LENGTH (expanded_types);
9758 /* Zero-length parameter packs are boring. Just substitute
9761 RETURN (tsubst (TREE_CHAIN (t), args, complain,
9766 /* All we did was update the type. Make a note of that. */
9767 type = expanded_types;
9768 expanded_types = NULL_TREE;
9772 /* Loop through all of the parameter's we'll build. When T is
9773 a function parameter pack, LEN is the number of expanded
9774 types in EXPANDED_TYPES; otherwise, LEN is 1. */
9776 for (i = 0; i < len; ++i)
9780 if (DECL_TEMPLATE_PARM_P (t))
9781 SET_DECL_TEMPLATE_PARM_P (r);
9783 /* An argument of a function parameter pack is not a parameter
9785 FUNCTION_PARAMETER_PACK_P (r) = false;
9788 /* We're on the Ith parameter of the function parameter
9791 /* Get the Ith type. */
9792 type = TREE_VEC_ELT (expanded_types, i);
9795 /* Rename the parameter to include the index. */
9797 make_ith_pack_parameter_name (DECL_NAME (r), i);
9800 /* We're dealing with a normal parameter. */
9801 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9803 type = type_decays_to (type);
9804 TREE_TYPE (r) = type;
9805 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
9807 if (DECL_INITIAL (r))
9809 if (TREE_CODE (DECL_INITIAL (r)) != TEMPLATE_PARM_INDEX)
9810 DECL_INITIAL (r) = TREE_TYPE (r);
9812 DECL_INITIAL (r) = tsubst (DECL_INITIAL (r), args,
9816 DECL_CONTEXT (r) = NULL_TREE;
9818 if (!DECL_TEMPLATE_PARM_P (r))
9819 DECL_ARG_TYPE (r) = type_passed_as (type);
9821 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
9822 args, complain, in_decl);
9824 /* Keep track of the first new parameter we
9825 generate. That's what will be returned to the
9830 /* Build a proper chain of parameters when substituting
9831 into a function parameter pack. */
9833 DECL_CHAIN (prev_r) = r;
9837 DECL_CHAIN (r) = tsubst (DECL_CHAIN (t), args,
9838 complain, DECL_CHAIN (t));
9840 /* FIRST_R contains the start of the chain we've built. */
9850 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9851 if (type == error_mark_node)
9852 RETURN (error_mark_node);
9853 TREE_TYPE (r) = type;
9854 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
9856 /* DECL_INITIAL gives the number of bits in a bit-field. */
9858 = tsubst_expr (DECL_INITIAL (t), args,
9860 /*integral_constant_expression_p=*/true);
9861 /* We don't have to set DECL_CONTEXT here; it is set by
9862 finish_member_declaration. */
9863 DECL_CHAIN (r) = NULL_TREE;
9864 if (VOID_TYPE_P (type))
9865 error ("instantiation of %q+D as type %qT", r, type);
9867 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
9868 args, complain, in_decl);
9873 /* We reach here only for member using decls. */
9874 if (DECL_DEPENDENT_P (t))
9876 r = do_class_using_decl
9877 (tsubst_copy (USING_DECL_SCOPE (t), args, complain, in_decl),
9878 tsubst_copy (DECL_NAME (t), args, complain, in_decl));
9880 r = error_mark_node;
9883 TREE_PROTECTED (r) = TREE_PROTECTED (t);
9884 TREE_PRIVATE (r) = TREE_PRIVATE (t);
9890 DECL_CHAIN (r) = NULL_TREE;
9897 tree argvec = NULL_TREE;
9898 tree gen_tmpl = NULL_TREE;
9900 tree tmpl = NULL_TREE;
9902 tree type = NULL_TREE;
9905 if (TREE_CODE (t) == TYPE_DECL
9906 && t == TYPE_MAIN_DECL (TREE_TYPE (t)))
9908 /* If this is the canonical decl, we don't have to
9909 mess with instantiations, and often we can't (for
9910 typename, template type parms and such). Note that
9911 TYPE_NAME is not correct for the above test if
9912 we've copied the type for a typedef. */
9913 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9914 if (type == error_mark_node)
9915 RETURN (error_mark_node);
9916 r = TYPE_NAME (type);
9920 /* Check to see if we already have the specialization we
9923 if (DECL_CLASS_SCOPE_P (t) || DECL_NAMESPACE_SCOPE_P (t))
9925 /* T is a static data member or namespace-scope entity.
9926 We have to substitute into namespace-scope variables
9927 (even though such entities are never templates) because
9930 template <class T> void f() { extern T t; }
9932 where the entity referenced is not known until
9933 instantiation time. */
9935 ctx = DECL_CONTEXT (t);
9936 if (DECL_CLASS_SCOPE_P (t))
9938 ctx = tsubst_aggr_type (ctx, args,
9940 in_decl, /*entering_scope=*/1);
9941 /* If CTX is unchanged, then T is in fact the
9942 specialization we want. That situation occurs when
9943 referencing a static data member within in its own
9944 class. We can use pointer equality, rather than
9945 same_type_p, because DECL_CONTEXT is always
9947 if (ctx == DECL_CONTEXT (t))
9953 tmpl = DECL_TI_TEMPLATE (t);
9954 gen_tmpl = most_general_template (tmpl);
9955 argvec = tsubst (DECL_TI_ARGS (t), args, complain, in_decl);
9956 hash = hash_tmpl_and_args (gen_tmpl, argvec);
9957 spec = retrieve_specialization (gen_tmpl, argvec, hash);
9962 /* A local variable. */
9964 /* Subsequent calls to pushdecl will fill this in. */
9966 spec = retrieve_local_specialization (t);
9968 /* If we already have the specialization we need, there is
9969 nothing more to do. */
9976 /* Create a new node for the specialization we need. */
9978 if (type == NULL_TREE)
9980 if (is_typedef_decl (t))
9981 type = DECL_ORIGINAL_TYPE (t);
9983 type = TREE_TYPE (t);
9984 if (TREE_CODE (t) == VAR_DECL && VAR_HAD_UNKNOWN_BOUND (t))
9985 type = strip_array_domain (type);
9986 type = tsubst (type, args, complain, in_decl);
9988 if (TREE_CODE (r) == VAR_DECL)
9990 /* Even if the original location is out of scope, the
9991 newly substituted one is not. */
9992 DECL_DEAD_FOR_LOCAL (r) = 0;
9993 DECL_INITIALIZED_P (r) = 0;
9994 DECL_TEMPLATE_INSTANTIATED (r) = 0;
9995 if (type == error_mark_node)
9996 RETURN (error_mark_node);
9997 if (TREE_CODE (type) == FUNCTION_TYPE)
9999 /* It may seem that this case cannot occur, since:
10004 declares a function, not a variable. However:
10007 template <typename T> void g() { T t; }
10008 template void g<f>();
10010 is an attempt to declare a variable with function
10012 error ("variable %qD has function type",
10013 /* R is not yet sufficiently initialized, so we
10014 just use its name. */
10016 RETURN (error_mark_node);
10018 type = complete_type (type);
10019 /* Wait until cp_finish_decl to set this again, to handle
10020 circular dependency (template/instantiate6.C). */
10021 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r) = 0;
10022 type = check_var_type (DECL_NAME (r), type);
10024 if (DECL_HAS_VALUE_EXPR_P (t))
10026 tree ve = DECL_VALUE_EXPR (t);
10027 ve = tsubst_expr (ve, args, complain, in_decl,
10028 /*constant_expression_p=*/false);
10029 SET_DECL_VALUE_EXPR (r, ve);
10032 else if (DECL_SELF_REFERENCE_P (t))
10033 SET_DECL_SELF_REFERENCE_P (r);
10034 TREE_TYPE (r) = type;
10035 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
10036 DECL_CONTEXT (r) = ctx;
10037 /* Clear out the mangled name and RTL for the instantiation. */
10038 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
10039 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
10040 SET_DECL_RTL (r, NULL);
10041 /* The initializer must not be expanded until it is required;
10042 see [temp.inst]. */
10043 DECL_INITIAL (r) = NULL_TREE;
10044 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
10045 SET_DECL_RTL (r, NULL);
10046 DECL_SIZE (r) = DECL_SIZE_UNIT (r) = 0;
10047 if (TREE_CODE (r) == VAR_DECL)
10049 /* Possibly limit visibility based on template args. */
10050 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
10051 if (DECL_VISIBILITY_SPECIFIED (t))
10053 DECL_VISIBILITY_SPECIFIED (r) = 0;
10054 DECL_ATTRIBUTES (r)
10055 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
10057 determine_visibility (r);
10062 /* A static data member declaration is always marked
10063 external when it is declared in-class, even if an
10064 initializer is present. We mimic the non-template
10065 processing here. */
10066 DECL_EXTERNAL (r) = 1;
10068 register_specialization (r, gen_tmpl, argvec, false, hash);
10069 DECL_TEMPLATE_INFO (r) = build_template_info (tmpl, argvec);
10070 SET_DECL_IMPLICIT_INSTANTIATION (r);
10072 else if (cp_unevaluated_operand)
10074 /* We're substituting this var in a decltype outside of its
10075 scope, such as for a lambda return type. Don't add it to
10076 local_specializations, do perform auto deduction. */
10077 tree auto_node = type_uses_auto (type);
10079 = tsubst_expr (DECL_INITIAL (t), args, complain, in_decl,
10080 /*constant_expression_p=*/false);
10082 if (auto_node && init)
10084 init = resolve_nondeduced_context (init);
10085 if (describable_type (init))
10087 type = do_auto_deduction (type, init, auto_node);
10088 TREE_TYPE (r) = type;
10093 register_local_specialization (r, t);
10095 DECL_CHAIN (r) = NULL_TREE;
10097 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r),
10099 args, complain, in_decl);
10101 /* Preserve a typedef that names a type. */
10102 if (is_typedef_decl (r))
10104 DECL_ORIGINAL_TYPE (r) = NULL_TREE;
10105 set_underlying_type (r);
10108 layout_decl (r, 0);
10113 gcc_unreachable ();
10118 /* Restore the file and line information. */
10119 input_location = saved_loc;
10124 /* Substitute into the ARG_TYPES of a function type. */
10127 tsubst_arg_types (tree arg_types,
10129 tsubst_flags_t complain,
10132 tree remaining_arg_types;
10133 tree type = NULL_TREE;
10135 tree expanded_args = NULL_TREE;
10138 if (!arg_types || arg_types == void_list_node)
10141 remaining_arg_types = tsubst_arg_types (TREE_CHAIN (arg_types),
10142 args, complain, in_decl);
10143 if (remaining_arg_types == error_mark_node)
10144 return error_mark_node;
10146 if (PACK_EXPANSION_P (TREE_VALUE (arg_types)))
10148 /* For a pack expansion, perform substitution on the
10149 entire expression. Later on, we'll handle the arguments
10151 expanded_args = tsubst_pack_expansion (TREE_VALUE (arg_types),
10152 args, complain, in_decl);
10154 if (TREE_CODE (expanded_args) == TREE_VEC)
10155 /* So that we'll spin through the parameters, one by one. */
10156 i = TREE_VEC_LENGTH (expanded_args);
10159 /* We only partially substituted into the parameter
10160 pack. Our type is TYPE_PACK_EXPANSION. */
10161 type = expanded_args;
10162 expanded_args = NULL_TREE;
10170 type = TREE_VEC_ELT (expanded_args, i);
10172 type = tsubst (TREE_VALUE (arg_types), args, complain, in_decl);
10174 if (type == error_mark_node)
10175 return error_mark_node;
10176 if (VOID_TYPE_P (type))
10178 if (complain & tf_error)
10180 error ("invalid parameter type %qT", type);
10182 error ("in declaration %q+D", in_decl);
10184 return error_mark_node;
10187 /* Do array-to-pointer, function-to-pointer conversion, and ignore
10188 top-level qualifiers as required. */
10189 type = TYPE_MAIN_VARIANT (type_decays_to (type));
10191 /* We do not substitute into default arguments here. The standard
10192 mandates that they be instantiated only when needed, which is
10193 done in build_over_call. */
10194 default_arg = TREE_PURPOSE (arg_types);
10196 if (default_arg && TREE_CODE (default_arg) == DEFAULT_ARG)
10198 /* We've instantiated a template before its default arguments
10199 have been parsed. This can happen for a nested template
10200 class, and is not an error unless we require the default
10201 argument in a call of this function. */
10202 remaining_arg_types =
10203 tree_cons (default_arg, type, remaining_arg_types);
10204 VEC_safe_push (tree, gc, DEFARG_INSTANTIATIONS (default_arg),
10205 remaining_arg_types);
10208 remaining_arg_types =
10209 hash_tree_cons (default_arg, type, remaining_arg_types);
10212 return remaining_arg_types;
10215 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
10216 *not* handle the exception-specification for FNTYPE, because the
10217 initial substitution of explicitly provided template parameters
10218 during argument deduction forbids substitution into the
10219 exception-specification:
10223 All references in the function type of the function template to the
10224 corresponding template parameters are replaced by the specified tem-
10225 plate argument values. If a substitution in a template parameter or
10226 in the function type of the function template results in an invalid
10227 type, type deduction fails. [Note: The equivalent substitution in
10228 exception specifications is done only when the function is instanti-
10229 ated, at which point a program is ill-formed if the substitution
10230 results in an invalid type.] */
10233 tsubst_function_type (tree t,
10235 tsubst_flags_t complain,
10242 /* The TYPE_CONTEXT is not used for function/method types. */
10243 gcc_assert (TYPE_CONTEXT (t) == NULL_TREE);
10245 /* Substitute the return type. */
10246 return_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10247 if (return_type == error_mark_node)
10248 return error_mark_node;
10249 /* The standard does not presently indicate that creation of a
10250 function type with an invalid return type is a deduction failure.
10251 However, that is clearly analogous to creating an array of "void"
10252 or a reference to a reference. This is core issue #486. */
10253 if (TREE_CODE (return_type) == ARRAY_TYPE
10254 || TREE_CODE (return_type) == FUNCTION_TYPE)
10256 if (complain & tf_error)
10258 if (TREE_CODE (return_type) == ARRAY_TYPE)
10259 error ("function returning an array");
10261 error ("function returning a function");
10263 return error_mark_node;
10266 /* Substitute the argument types. */
10267 arg_types = tsubst_arg_types (TYPE_ARG_TYPES (t), args,
10268 complain, in_decl);
10269 if (arg_types == error_mark_node)
10270 return error_mark_node;
10272 /* Construct a new type node and return it. */
10273 if (TREE_CODE (t) == FUNCTION_TYPE)
10275 fntype = build_function_type (return_type, arg_types);
10276 fntype = apply_memfn_quals (fntype, type_memfn_quals (t));
10280 tree r = TREE_TYPE (TREE_VALUE (arg_types));
10281 if (! MAYBE_CLASS_TYPE_P (r))
10285 Type deduction may fail for any of the following
10288 -- Attempting to create "pointer to member of T" when T
10289 is not a class type. */
10290 if (complain & tf_error)
10291 error ("creating pointer to member function of non-class type %qT",
10293 return error_mark_node;
10296 fntype = build_method_type_directly (r, return_type,
10297 TREE_CHAIN (arg_types));
10299 fntype = cp_build_type_attribute_variant (fntype, TYPE_ATTRIBUTES (t));
10304 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
10305 ARGS into that specification, and return the substituted
10306 specification. If there is no specification, return NULL_TREE. */
10309 tsubst_exception_specification (tree fntype,
10311 tsubst_flags_t complain,
10317 specs = TYPE_RAISES_EXCEPTIONS (fntype);
10318 new_specs = NULL_TREE;
10319 if (specs && TREE_PURPOSE (specs))
10321 /* A noexcept-specifier. */
10322 new_specs = tsubst_copy_and_build
10323 (TREE_PURPOSE (specs), args, complain, in_decl, /*function_p=*/false,
10324 /*integral_constant_expression_p=*/true);
10325 new_specs = build_noexcept_spec (new_specs, complain);
10329 if (! TREE_VALUE (specs))
10336 tree expanded_specs = NULL_TREE;
10338 if (PACK_EXPANSION_P (TREE_VALUE (specs)))
10340 /* Expand the pack expansion type. */
10341 expanded_specs = tsubst_pack_expansion (TREE_VALUE (specs),
10345 if (expanded_specs == error_mark_node)
10346 return error_mark_node;
10347 else if (TREE_CODE (expanded_specs) == TREE_VEC)
10348 len = TREE_VEC_LENGTH (expanded_specs);
10351 /* We're substituting into a member template, so
10352 we got a TYPE_PACK_EXPANSION back. Add that
10353 expansion and move on. */
10354 gcc_assert (TREE_CODE (expanded_specs)
10355 == TYPE_PACK_EXPANSION);
10356 new_specs = add_exception_specifier (new_specs,
10359 specs = TREE_CHAIN (specs);
10364 for (i = 0; i < len; ++i)
10366 if (expanded_specs)
10367 spec = TREE_VEC_ELT (expanded_specs, i);
10369 spec = tsubst (TREE_VALUE (specs), args, complain, in_decl);
10370 if (spec == error_mark_node)
10372 new_specs = add_exception_specifier (new_specs, spec,
10376 specs = TREE_CHAIN (specs);
10382 /* Take the tree structure T and replace template parameters used
10383 therein with the argument vector ARGS. IN_DECL is an associated
10384 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
10385 Issue error and warning messages under control of COMPLAIN. Note
10386 that we must be relatively non-tolerant of extensions here, in
10387 order to preserve conformance; if we allow substitutions that
10388 should not be allowed, we may allow argument deductions that should
10389 not succeed, and therefore report ambiguous overload situations
10390 where there are none. In theory, we could allow the substitution,
10391 but indicate that it should have failed, and allow our caller to
10392 make sure that the right thing happens, but we don't try to do this
10395 This function is used for dealing with types, decls and the like;
10396 for expressions, use tsubst_expr or tsubst_copy. */
10399 tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl)
10401 enum tree_code code;
10404 if (t == NULL_TREE || t == error_mark_node
10405 || t == integer_type_node
10406 || t == void_type_node
10407 || t == char_type_node
10408 || t == unknown_type_node
10409 || TREE_CODE (t) == NAMESPACE_DECL
10410 || TREE_CODE (t) == TRANSLATION_UNIT_DECL)
10414 return tsubst_decl (t, args, complain);
10416 if (args == NULL_TREE)
10419 code = TREE_CODE (t);
10421 if (code == IDENTIFIER_NODE)
10422 type = IDENTIFIER_TYPE_VALUE (t);
10424 type = TREE_TYPE (t);
10426 gcc_assert (type != unknown_type_node);
10428 /* Reuse typedefs. We need to do this to handle dependent attributes,
10429 such as attribute aligned. */
10431 && typedef_variant_p (t))
10433 tree decl = TYPE_NAME (t);
10435 if (DECL_CLASS_SCOPE_P (decl)
10436 && CLASSTYPE_TEMPLATE_INFO (DECL_CONTEXT (decl))
10437 && uses_template_parms (DECL_CONTEXT (decl)))
10439 tree tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
10440 tree gen_args = tsubst (DECL_TI_ARGS (decl), args, complain, in_decl);
10441 r = retrieve_specialization (tmpl, gen_args, 0);
10443 else if (DECL_FUNCTION_SCOPE_P (decl)
10444 && DECL_TEMPLATE_INFO (DECL_CONTEXT (decl))
10445 && uses_template_parms (DECL_TI_ARGS (DECL_CONTEXT (decl))))
10446 r = retrieve_local_specialization (decl);
10448 /* The typedef is from a non-template context. */
10454 r = cp_build_qualified_type_real
10455 (r, cp_type_quals (t) | cp_type_quals (r),
10456 complain | tf_ignore_bad_quals);
10459 /* Else we must be instantiating the typedef, so fall through. */
10463 && code != TYPENAME_TYPE
10464 && code != TEMPLATE_TYPE_PARM
10465 && code != IDENTIFIER_NODE
10466 && code != FUNCTION_TYPE
10467 && code != METHOD_TYPE)
10468 type = tsubst (type, args, complain, in_decl);
10469 if (type == error_mark_node)
10470 return error_mark_node;
10476 case ENUMERAL_TYPE:
10477 return tsubst_aggr_type (t, args, complain, in_decl,
10478 /*entering_scope=*/0);
10481 case IDENTIFIER_NODE:
10492 if (t == integer_type_node)
10495 if (TREE_CODE (TYPE_MIN_VALUE (t)) == INTEGER_CST
10496 && TREE_CODE (TYPE_MAX_VALUE (t)) == INTEGER_CST)
10500 tree max, omax = TREE_OPERAND (TYPE_MAX_VALUE (t), 0);
10502 max = tsubst_expr (omax, args, complain, in_decl,
10503 /*integral_constant_expression_p=*/false);
10505 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
10507 if (TREE_CODE (max) == NOP_EXPR
10508 && TREE_SIDE_EFFECTS (omax)
10509 && !TREE_TYPE (max))
10510 TREE_TYPE (max) = TREE_TYPE (TREE_OPERAND (max, 0));
10512 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
10513 with TREE_SIDE_EFFECTS that indicates this is not an integral
10514 constant expression. */
10515 if (processing_template_decl
10516 && TREE_SIDE_EFFECTS (omax) && TREE_CODE (omax) == NOP_EXPR)
10518 gcc_assert (TREE_CODE (max) == NOP_EXPR);
10519 TREE_SIDE_EFFECTS (max) = 1;
10522 return compute_array_index_type (NULL_TREE, max, complain);
10525 case TEMPLATE_TYPE_PARM:
10526 case TEMPLATE_TEMPLATE_PARM:
10527 case BOUND_TEMPLATE_TEMPLATE_PARM:
10528 case TEMPLATE_PARM_INDEX:
10533 tree arg = NULL_TREE;
10537 gcc_assert (TREE_VEC_LENGTH (args) > 0);
10538 template_parm_level_and_index (t, &level, &idx);
10540 levels = TMPL_ARGS_DEPTH (args);
10541 if (level <= levels)
10543 arg = TMPL_ARG (args, level, idx);
10545 if (arg && TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
10546 /* See through ARGUMENT_PACK_SELECT arguments. */
10547 arg = ARGUMENT_PACK_SELECT_ARG (arg);
10550 if (arg == error_mark_node)
10551 return error_mark_node;
10552 else if (arg != NULL_TREE)
10554 if (ARGUMENT_PACK_P (arg))
10555 /* If ARG is an argument pack, we don't actually want to
10556 perform a substitution here, because substitutions
10557 for argument packs are only done
10558 element-by-element. We can get to this point when
10559 substituting the type of a non-type template
10560 parameter pack, when that type actually contains
10561 template parameter packs from an outer template, e.g.,
10563 template<typename... Types> struct A {
10564 template<Types... Values> struct B { };
10568 if (code == TEMPLATE_TYPE_PARM)
10571 gcc_assert (TYPE_P (arg));
10573 quals = cp_type_quals (arg) | cp_type_quals (t);
10575 return cp_build_qualified_type_real
10576 (arg, quals, complain | tf_ignore_bad_quals);
10578 else if (code == BOUND_TEMPLATE_TEMPLATE_PARM)
10580 /* We are processing a type constructed from a
10581 template template parameter. */
10582 tree argvec = tsubst (TYPE_TI_ARGS (t),
10583 args, complain, in_decl);
10584 if (argvec == error_mark_node)
10585 return error_mark_node;
10587 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
10588 are resolving nested-types in the signature of a
10589 member function templates. Otherwise ARG is a
10590 TEMPLATE_DECL and is the real template to be
10592 if (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
10593 arg = TYPE_NAME (arg);
10595 r = lookup_template_class (arg,
10597 DECL_CONTEXT (arg),
10598 /*entering_scope=*/0,
10600 return cp_build_qualified_type_real
10601 (r, cp_type_quals (t), complain);
10604 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
10605 return unshare_expr (arg);
10609 /* This can happen during the attempted tsubst'ing in
10610 unify. This means that we don't yet have any information
10611 about the template parameter in question. */
10614 /* If we get here, we must have been looking at a parm for a
10615 more deeply nested template. Make a new version of this
10616 template parameter, but with a lower level. */
10619 case TEMPLATE_TYPE_PARM:
10620 case TEMPLATE_TEMPLATE_PARM:
10621 case BOUND_TEMPLATE_TEMPLATE_PARM:
10622 if (cp_type_quals (t))
10624 r = tsubst (TYPE_MAIN_VARIANT (t), args, complain, in_decl);
10625 r = cp_build_qualified_type_real
10626 (r, cp_type_quals (t),
10627 complain | (code == TEMPLATE_TYPE_PARM
10628 ? tf_ignore_bad_quals : 0));
10633 TEMPLATE_TYPE_PARM_INDEX (r)
10634 = reduce_template_parm_level (TEMPLATE_TYPE_PARM_INDEX (t),
10635 r, levels, args, complain);
10636 TYPE_STUB_DECL (r) = TYPE_NAME (r) = TEMPLATE_TYPE_DECL (r);
10637 TYPE_MAIN_VARIANT (r) = r;
10638 TYPE_POINTER_TO (r) = NULL_TREE;
10639 TYPE_REFERENCE_TO (r) = NULL_TREE;
10641 if (TREE_CODE (r) == TEMPLATE_TEMPLATE_PARM)
10642 /* We have reduced the level of the template
10643 template parameter, but not the levels of its
10644 template parameters, so canonical_type_parameter
10645 will not be able to find the canonical template
10646 template parameter for this level. Thus, we
10647 require structural equality checking to compare
10648 TEMPLATE_TEMPLATE_PARMs. */
10649 SET_TYPE_STRUCTURAL_EQUALITY (r);
10650 else if (TYPE_STRUCTURAL_EQUALITY_P (t))
10651 SET_TYPE_STRUCTURAL_EQUALITY (r);
10653 TYPE_CANONICAL (r) = canonical_type_parameter (r);
10655 if (code == BOUND_TEMPLATE_TEMPLATE_PARM)
10657 tree argvec = tsubst (TYPE_TI_ARGS (t), args,
10658 complain, in_decl);
10659 if (argvec == error_mark_node)
10660 return error_mark_node;
10662 TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (r)
10663 = build_template_info (TYPE_TI_TEMPLATE (t), argvec);
10668 case TEMPLATE_PARM_INDEX:
10669 r = reduce_template_parm_level (t, type, levels, args, complain);
10673 gcc_unreachable ();
10681 tree purpose, value, chain;
10683 if (t == void_list_node)
10686 purpose = TREE_PURPOSE (t);
10689 purpose = tsubst (purpose, args, complain, in_decl);
10690 if (purpose == error_mark_node)
10691 return error_mark_node;
10693 value = TREE_VALUE (t);
10696 value = tsubst (value, args, complain, in_decl);
10697 if (value == error_mark_node)
10698 return error_mark_node;
10700 chain = TREE_CHAIN (t);
10701 if (chain && chain != void_type_node)
10703 chain = tsubst (chain, args, complain, in_decl);
10704 if (chain == error_mark_node)
10705 return error_mark_node;
10707 if (purpose == TREE_PURPOSE (t)
10708 && value == TREE_VALUE (t)
10709 && chain == TREE_CHAIN (t))
10711 return hash_tree_cons (purpose, value, chain);
10715 /* We should never be tsubsting a binfo. */
10716 gcc_unreachable ();
10719 /* A vector of template arguments. */
10720 gcc_assert (!type);
10721 return tsubst_template_args (t, args, complain, in_decl);
10724 case REFERENCE_TYPE:
10726 if (type == TREE_TYPE (t) && TREE_CODE (type) != METHOD_TYPE)
10731 Type deduction may fail for any of the following
10734 -- Attempting to create a pointer to reference type.
10735 -- Attempting to create a reference to a reference type or
10736 a reference to void.
10738 Core issue 106 says that creating a reference to a reference
10739 during instantiation is no longer a cause for failure. We
10740 only enforce this check in strict C++98 mode. */
10741 if ((TREE_CODE (type) == REFERENCE_TYPE
10742 && (((cxx_dialect == cxx98) && flag_iso) || code != REFERENCE_TYPE))
10743 || (code == REFERENCE_TYPE && TREE_CODE (type) == VOID_TYPE))
10745 static location_t last_loc;
10747 /* We keep track of the last time we issued this error
10748 message to avoid spewing a ton of messages during a
10749 single bad template instantiation. */
10750 if (complain & tf_error
10751 && last_loc != input_location)
10753 if (TREE_CODE (type) == VOID_TYPE)
10754 error ("forming reference to void");
10755 else if (code == POINTER_TYPE)
10756 error ("forming pointer to reference type %qT", type);
10758 error ("forming reference to reference type %qT", type);
10759 last_loc = input_location;
10762 return error_mark_node;
10764 else if (code == POINTER_TYPE)
10766 r = build_pointer_type (type);
10767 if (TREE_CODE (type) == METHOD_TYPE)
10768 r = build_ptrmemfunc_type (r);
10770 else if (TREE_CODE (type) == REFERENCE_TYPE)
10771 /* In C++0x, during template argument substitution, when there is an
10772 attempt to create a reference to a reference type, reference
10773 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
10775 "If a template-argument for a template-parameter T names a type
10776 that is a reference to a type A, an attempt to create the type
10777 'lvalue reference to cv T' creates the type 'lvalue reference to
10778 A,' while an attempt to create the type type rvalue reference to
10779 cv T' creates the type T"
10781 r = cp_build_reference_type
10783 TYPE_REF_IS_RVALUE (t) && TYPE_REF_IS_RVALUE (type));
10785 r = cp_build_reference_type (type, TYPE_REF_IS_RVALUE (t));
10786 r = cp_build_qualified_type_real (r, cp_type_quals (t), complain);
10788 if (r != error_mark_node)
10789 /* Will this ever be needed for TYPE_..._TO values? */
10796 r = tsubst (TYPE_OFFSET_BASETYPE (t), args, complain, in_decl);
10797 if (r == error_mark_node || !MAYBE_CLASS_TYPE_P (r))
10801 Type deduction may fail for any of the following
10804 -- Attempting to create "pointer to member of T" when T
10805 is not a class type. */
10806 if (complain & tf_error)
10807 error ("creating pointer to member of non-class type %qT", r);
10808 return error_mark_node;
10810 if (TREE_CODE (type) == REFERENCE_TYPE)
10812 if (complain & tf_error)
10813 error ("creating pointer to member reference type %qT", type);
10814 return error_mark_node;
10816 if (TREE_CODE (type) == VOID_TYPE)
10818 if (complain & tf_error)
10819 error ("creating pointer to member of type void");
10820 return error_mark_node;
10822 gcc_assert (TREE_CODE (type) != METHOD_TYPE);
10823 if (TREE_CODE (type) == FUNCTION_TYPE)
10825 /* The type of the implicit object parameter gets its
10826 cv-qualifiers from the FUNCTION_TYPE. */
10828 tree method_type = build_memfn_type (type, r, type_memfn_quals (type));
10829 memptr = build_ptrmemfunc_type (build_pointer_type (method_type));
10830 return cp_build_qualified_type_real (memptr, cp_type_quals (t),
10834 return cp_build_qualified_type_real (build_ptrmem_type (r, type),
10838 case FUNCTION_TYPE:
10843 fntype = tsubst_function_type (t, args, complain, in_decl);
10844 if (fntype == error_mark_node)
10845 return error_mark_node;
10847 /* Substitute the exception specification. */
10848 specs = tsubst_exception_specification (t, args, complain,
10850 if (specs == error_mark_node)
10851 return error_mark_node;
10853 fntype = build_exception_variant (fntype, specs);
10858 tree domain = tsubst (TYPE_DOMAIN (t), args, complain, in_decl);
10859 if (domain == error_mark_node)
10860 return error_mark_node;
10862 /* As an optimization, we avoid regenerating the array type if
10863 it will obviously be the same as T. */
10864 if (type == TREE_TYPE (t) && domain == TYPE_DOMAIN (t))
10867 /* These checks should match the ones in grokdeclarator.
10871 The deduction may fail for any of the following reasons:
10873 -- Attempting to create an array with an element type that
10874 is void, a function type, or a reference type, or [DR337]
10875 an abstract class type. */
10876 if (TREE_CODE (type) == VOID_TYPE
10877 || TREE_CODE (type) == FUNCTION_TYPE
10878 || TREE_CODE (type) == REFERENCE_TYPE)
10880 if (complain & tf_error)
10881 error ("creating array of %qT", type);
10882 return error_mark_node;
10884 if (CLASS_TYPE_P (type) && CLASSTYPE_PURE_VIRTUALS (type))
10886 if (complain & tf_error)
10887 error ("creating array of %qT, which is an abstract class type",
10889 return error_mark_node;
10892 r = build_cplus_array_type (type, domain);
10894 if (TYPE_USER_ALIGN (t))
10896 TYPE_ALIGN (r) = TYPE_ALIGN (t);
10897 TYPE_USER_ALIGN (r) = 1;
10903 case TYPENAME_TYPE:
10905 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
10906 in_decl, /*entering_scope=*/1);
10907 tree f = tsubst_copy (TYPENAME_TYPE_FULLNAME (t), args,
10908 complain, in_decl);
10910 if (ctx == error_mark_node || f == error_mark_node)
10911 return error_mark_node;
10913 if (!MAYBE_CLASS_TYPE_P (ctx))
10915 if (complain & tf_error)
10916 error ("%qT is not a class, struct, or union type", ctx);
10917 return error_mark_node;
10919 else if (!uses_template_parms (ctx) && !TYPE_BEING_DEFINED (ctx))
10921 /* Normally, make_typename_type does not require that the CTX
10922 have complete type in order to allow things like:
10924 template <class T> struct S { typename S<T>::X Y; };
10926 But, such constructs have already been resolved by this
10927 point, so here CTX really should have complete type, unless
10928 it's a partial instantiation. */
10929 ctx = complete_type (ctx);
10930 if (!COMPLETE_TYPE_P (ctx))
10932 if (complain & tf_error)
10933 cxx_incomplete_type_error (NULL_TREE, ctx);
10934 return error_mark_node;
10938 f = make_typename_type (ctx, f, typename_type,
10939 (complain & tf_error) | tf_keep_type_decl);
10940 if (f == error_mark_node)
10942 if (TREE_CODE (f) == TYPE_DECL)
10944 complain |= tf_ignore_bad_quals;
10948 if (TREE_CODE (f) != TYPENAME_TYPE)
10950 if (TYPENAME_IS_ENUM_P (t) && TREE_CODE (f) != ENUMERAL_TYPE)
10952 if (complain & tf_error)
10953 error ("%qT resolves to %qT, which is not an enumeration type",
10956 return error_mark_node;
10958 else if (TYPENAME_IS_CLASS_P (t) && !CLASS_TYPE_P (f))
10960 if (complain & tf_error)
10961 error ("%qT resolves to %qT, which is is not a class type",
10964 return error_mark_node;
10968 return cp_build_qualified_type_real
10969 (f, cp_type_quals (f) | cp_type_quals (t), complain);
10972 case UNBOUND_CLASS_TEMPLATE:
10974 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
10975 in_decl, /*entering_scope=*/1);
10976 tree name = TYPE_IDENTIFIER (t);
10977 tree parm_list = DECL_TEMPLATE_PARMS (TYPE_NAME (t));
10979 if (ctx == error_mark_node || name == error_mark_node)
10980 return error_mark_node;
10983 parm_list = tsubst_template_parms (parm_list, args, complain);
10984 return make_unbound_class_template (ctx, name, parm_list, complain);
10991 ++cp_unevaluated_operand;
10992 ++c_inhibit_evaluation_warnings;
10994 type = tsubst_expr (TYPEOF_TYPE_EXPR (t), args,
10996 /*integral_constant_expression_p=*/false);
10998 --cp_unevaluated_operand;
10999 --c_inhibit_evaluation_warnings;
11001 type = finish_typeof (type);
11002 return cp_build_qualified_type_real (type,
11004 | cp_type_quals (type),
11008 case DECLTYPE_TYPE:
11012 ++cp_unevaluated_operand;
11013 ++c_inhibit_evaluation_warnings;
11015 type = tsubst_expr (DECLTYPE_TYPE_EXPR (t), args,
11017 /*integral_constant_expression_p=*/false);
11019 --cp_unevaluated_operand;
11020 --c_inhibit_evaluation_warnings;
11022 if (DECLTYPE_FOR_LAMBDA_CAPTURE (t))
11023 type = lambda_capture_field_type (type);
11024 else if (DECLTYPE_FOR_LAMBDA_RETURN (t))
11025 type = lambda_return_type (type);
11027 type = finish_decltype_type
11028 (type, DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t), complain);
11029 return cp_build_qualified_type_real (type,
11031 | cp_type_quals (type),
11035 case TYPE_ARGUMENT_PACK:
11036 case NONTYPE_ARGUMENT_PACK:
11038 tree r = TYPE_P (t) ? cxx_make_type (code) : make_node (code);
11040 tsubst_template_args (ARGUMENT_PACK_ARGS (t),
11044 SET_ARGUMENT_PACK_ARGS (r, packed_out);
11046 /* For template nontype argument packs, also substitute into
11048 if (code == NONTYPE_ARGUMENT_PACK)
11049 TREE_TYPE (r) = tsubst (TREE_TYPE (t), args, complain, in_decl);
11067 /* We should use one of the expression tsubsts for these codes. */
11068 gcc_unreachable ();
11071 sorry ("use of %qs in template", tree_code_name [(int) code]);
11072 return error_mark_node;
11076 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
11077 type of the expression on the left-hand side of the "." or "->"
11081 tsubst_baselink (tree baselink, tree object_type,
11082 tree args, tsubst_flags_t complain, tree in_decl)
11085 tree qualifying_scope;
11088 tree template_args = 0;
11089 bool template_id_p = false;
11091 /* A baselink indicates a function from a base class. Both the
11092 BASELINK_ACCESS_BINFO and the base class referenced may
11093 indicate bases of the template class, rather than the
11094 instantiated class. In addition, lookups that were not
11095 ambiguous before may be ambiguous now. Therefore, we perform
11096 the lookup again. */
11097 qualifying_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (baselink));
11098 qualifying_scope = tsubst (qualifying_scope, args,
11099 complain, in_decl);
11100 fns = BASELINK_FUNCTIONS (baselink);
11101 optype = tsubst (BASELINK_OPTYPE (baselink), args, complain, in_decl);
11102 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
11104 template_id_p = true;
11105 template_args = TREE_OPERAND (fns, 1);
11106 fns = TREE_OPERAND (fns, 0);
11108 template_args = tsubst_template_args (template_args, args,
11109 complain, in_decl);
11111 name = DECL_NAME (get_first_fn (fns));
11112 if (IDENTIFIER_TYPENAME_P (name))
11113 name = mangle_conv_op_name_for_type (optype);
11114 baselink = lookup_fnfields (qualifying_scope, name, /*protect=*/1);
11116 return error_mark_node;
11118 /* If lookup found a single function, mark it as used at this
11119 point. (If it lookup found multiple functions the one selected
11120 later by overload resolution will be marked as used at that
11122 if (BASELINK_P (baselink))
11123 fns = BASELINK_FUNCTIONS (baselink);
11124 if (!template_id_p && !really_overloaded_fn (fns))
11125 mark_used (OVL_CURRENT (fns));
11127 /* Add back the template arguments, if present. */
11128 if (BASELINK_P (baselink) && template_id_p)
11129 BASELINK_FUNCTIONS (baselink)
11130 = build_nt (TEMPLATE_ID_EXPR,
11131 BASELINK_FUNCTIONS (baselink),
11133 /* Update the conversion operator type. */
11134 BASELINK_OPTYPE (baselink) = optype;
11137 object_type = current_class_type;
11138 return adjust_result_of_qualified_name_lookup (baselink,
11143 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
11144 true if the qualified-id will be a postfix-expression in-and-of
11145 itself; false if more of the postfix-expression follows the
11146 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
11150 tsubst_qualified_id (tree qualified_id, tree args,
11151 tsubst_flags_t complain, tree in_decl,
11152 bool done, bool address_p)
11158 tree template_args;
11160 gcc_assert (TREE_CODE (qualified_id) == SCOPE_REF);
11162 /* Figure out what name to look up. */
11163 name = TREE_OPERAND (qualified_id, 1);
11164 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
11166 is_template = true;
11167 template_args = TREE_OPERAND (name, 1);
11169 template_args = tsubst_template_args (template_args, args,
11170 complain, in_decl);
11171 name = TREE_OPERAND (name, 0);
11175 is_template = false;
11176 template_args = NULL_TREE;
11179 /* Substitute into the qualifying scope. When there are no ARGS, we
11180 are just trying to simplify a non-dependent expression. In that
11181 case the qualifying scope may be dependent, and, in any case,
11182 substituting will not help. */
11183 scope = TREE_OPERAND (qualified_id, 0);
11186 scope = tsubst (scope, args, complain, in_decl);
11187 expr = tsubst_copy (name, args, complain, in_decl);
11192 if (dependent_scope_p (scope))
11193 return build_qualified_name (NULL_TREE, scope, expr,
11194 QUALIFIED_NAME_IS_TEMPLATE (qualified_id));
11196 if (!BASELINK_P (name) && !DECL_P (expr))
11198 if (TREE_CODE (expr) == BIT_NOT_EXPR)
11200 /* A BIT_NOT_EXPR is used to represent a destructor. */
11201 if (!check_dtor_name (scope, TREE_OPERAND (expr, 0)))
11203 error ("qualifying type %qT does not match destructor name ~%qT",
11204 scope, TREE_OPERAND (expr, 0));
11205 expr = error_mark_node;
11208 expr = lookup_qualified_name (scope, complete_dtor_identifier,
11209 /*is_type_p=*/0, false);
11212 expr = lookup_qualified_name (scope, expr, /*is_type_p=*/0, false);
11213 if (TREE_CODE (TREE_CODE (expr) == TEMPLATE_DECL
11214 ? DECL_TEMPLATE_RESULT (expr) : expr) == TYPE_DECL)
11216 if (complain & tf_error)
11218 error ("dependent-name %qE is parsed as a non-type, but "
11219 "instantiation yields a type", qualified_id);
11220 inform (input_location, "say %<typename %E%> if a type is meant", qualified_id);
11222 return error_mark_node;
11228 check_accessibility_of_qualified_id (expr, /*object_type=*/NULL_TREE,
11230 /* Remember that there was a reference to this entity. */
11234 if (expr == error_mark_node || TREE_CODE (expr) == TREE_LIST)
11236 if (complain & tf_error)
11237 qualified_name_lookup_error (scope,
11238 TREE_OPERAND (qualified_id, 1),
11239 expr, input_location);
11240 return error_mark_node;
11244 expr = lookup_template_function (expr, template_args);
11246 if (expr == error_mark_node && complain & tf_error)
11247 qualified_name_lookup_error (scope, TREE_OPERAND (qualified_id, 1),
11248 expr, input_location);
11249 else if (TYPE_P (scope))
11251 expr = (adjust_result_of_qualified_name_lookup
11252 (expr, scope, current_class_type));
11253 expr = (finish_qualified_id_expr
11254 (scope, expr, done, address_p,
11255 QUALIFIED_NAME_IS_TEMPLATE (qualified_id),
11256 /*template_arg_p=*/false));
11259 /* Expressions do not generally have reference type. */
11260 if (TREE_CODE (expr) != SCOPE_REF
11261 /* However, if we're about to form a pointer-to-member, we just
11262 want the referenced member referenced. */
11263 && TREE_CODE (expr) != OFFSET_REF)
11264 expr = convert_from_reference (expr);
11269 /* Like tsubst, but deals with expressions. This function just replaces
11270 template parms; to finish processing the resultant expression, use
11274 tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl)
11276 enum tree_code code;
11279 if (t == NULL_TREE || t == error_mark_node || args == NULL_TREE)
11282 code = TREE_CODE (t);
11287 r = retrieve_local_specialization (t);
11292 /* This can happen for a parameter name used later in a function
11293 declaration (such as in a late-specified return type). Just
11294 make a dummy decl, since it's only used for its type. */
11295 gcc_assert (cp_unevaluated_operand != 0);
11296 /* We copy T because want to tsubst the PARM_DECL only,
11297 not the following PARM_DECLs that are chained to T. */
11299 r = tsubst_decl (c, args, complain);
11300 /* Give it the template pattern as its context; its true context
11301 hasn't been instantiated yet and this is good enough for
11303 DECL_CONTEXT (r) = DECL_CONTEXT (t);
11306 if (TREE_CODE (r) == ARGUMENT_PACK_SELECT)
11307 r = ARGUMENT_PACK_SELECT_ARG (r);
11316 if (DECL_TEMPLATE_PARM_P (t))
11317 return tsubst_copy (DECL_INITIAL (t), args, complain, in_decl);
11318 /* There is no need to substitute into namespace-scope
11320 if (DECL_NAMESPACE_SCOPE_P (t))
11322 /* If ARGS is NULL, then T is known to be non-dependent. */
11323 if (args == NULL_TREE)
11324 return integral_constant_value (t);
11326 /* Unfortunately, we cannot just call lookup_name here.
11329 template <int I> int f() {
11331 struct S { void g() { E e = a; } };
11334 When we instantiate f<7>::S::g(), say, lookup_name is not
11335 clever enough to find f<7>::a. */
11337 = tsubst_aggr_type (TREE_TYPE (t), args, complain, in_decl,
11338 /*entering_scope=*/0);
11340 for (v = TYPE_VALUES (enum_type);
11342 v = TREE_CHAIN (v))
11343 if (TREE_PURPOSE (v) == DECL_NAME (t))
11344 return TREE_VALUE (v);
11346 /* We didn't find the name. That should never happen; if
11347 name-lookup found it during preliminary parsing, we
11348 should find it again here during instantiation. */
11349 gcc_unreachable ();
11354 if (DECL_CONTEXT (t))
11358 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args, complain, in_decl,
11359 /*entering_scope=*/1);
11360 if (ctx != DECL_CONTEXT (t))
11362 tree r = lookup_field (ctx, DECL_NAME (t), 0, false);
11365 if (complain & tf_error)
11366 error ("using invalid field %qD", t);
11367 return error_mark_node;
11376 case FUNCTION_DECL:
11377 if ((DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t))
11378 || local_variable_p (t))
11379 t = tsubst (t, args, complain, in_decl);
11384 /* An OVERLOAD will always be a non-dependent overload set; an
11385 overload set from function scope will just be represented with an
11386 IDENTIFIER_NODE, and from class scope with a BASELINK. */
11387 gcc_assert (!uses_template_parms (t));
11391 return tsubst_baselink (t, current_class_type, args, complain, in_decl);
11393 case TEMPLATE_DECL:
11394 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
11395 return tsubst (TREE_TYPE (DECL_TEMPLATE_RESULT (t)),
11396 args, complain, in_decl);
11397 else if (DECL_FUNCTION_TEMPLATE_P (t) && DECL_MEMBER_TEMPLATE_P (t))
11398 return tsubst (t, args, complain, in_decl);
11399 else if (DECL_CLASS_SCOPE_P (t)
11400 && uses_template_parms (DECL_CONTEXT (t)))
11402 /* Template template argument like the following example need
11405 template <template <class> class TT> struct C {};
11406 template <class T> struct D {
11407 template <class U> struct E {};
11412 We are processing the template argument `E' in #1 for
11413 the template instantiation #2. Originally, `E' is a
11414 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
11415 have to substitute this with one having context `D<int>'. */
11417 tree context = tsubst (DECL_CONTEXT (t), args, complain, in_decl);
11418 return lookup_field (context, DECL_NAME(t), 0, false);
11421 /* Ordinary template template argument. */
11425 case REINTERPRET_CAST_EXPR:
11426 case CONST_CAST_EXPR:
11427 case STATIC_CAST_EXPR:
11428 case DYNAMIC_CAST_EXPR:
11431 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
11432 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
11435 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
11441 ++cp_unevaluated_operand;
11442 ++c_inhibit_evaluation_warnings;
11443 /* We only want to compute the number of arguments. */
11444 expanded = tsubst_pack_expansion (TREE_OPERAND (t, 0), args,
11445 complain, in_decl);
11446 --cp_unevaluated_operand;
11447 --c_inhibit_evaluation_warnings;
11449 if (TREE_CODE (expanded) == TREE_VEC)
11450 len = TREE_VEC_LENGTH (expanded);
11452 if (expanded == error_mark_node)
11453 return error_mark_node;
11454 else if (PACK_EXPANSION_P (expanded)
11455 || (TREE_CODE (expanded) == TREE_VEC
11457 && PACK_EXPANSION_P (TREE_VEC_ELT (expanded, len-1))))
11459 if (TREE_CODE (expanded) == TREE_VEC)
11460 expanded = TREE_VEC_ELT (expanded, len - 1);
11462 if (TYPE_P (expanded))
11463 return cxx_sizeof_or_alignof_type (expanded, SIZEOF_EXPR,
11464 complain & tf_error);
11466 return cxx_sizeof_or_alignof_expr (expanded, SIZEOF_EXPR,
11467 complain & tf_error);
11470 return build_int_cst (size_type_node, len);
11476 case TRUTH_NOT_EXPR:
11479 case UNARY_PLUS_EXPR: /* Unary + */
11481 case AT_ENCODE_EXPR:
11485 case REALPART_EXPR:
11486 case IMAGPART_EXPR:
11488 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
11489 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
11491 case COMPONENT_REF:
11496 object = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
11497 name = TREE_OPERAND (t, 1);
11498 if (TREE_CODE (name) == BIT_NOT_EXPR)
11500 name = tsubst_copy (TREE_OPERAND (name, 0), args,
11501 complain, in_decl);
11502 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
11504 else if (TREE_CODE (name) == SCOPE_REF
11505 && TREE_CODE (TREE_OPERAND (name, 1)) == BIT_NOT_EXPR)
11507 tree base = tsubst_copy (TREE_OPERAND (name, 0), args,
11508 complain, in_decl);
11509 name = TREE_OPERAND (name, 1);
11510 name = tsubst_copy (TREE_OPERAND (name, 0), args,
11511 complain, in_decl);
11512 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
11513 name = build_qualified_name (/*type=*/NULL_TREE,
11515 /*template_p=*/false);
11517 else if (TREE_CODE (name) == BASELINK)
11518 name = tsubst_baselink (name,
11519 non_reference (TREE_TYPE (object)),
11523 name = tsubst_copy (name, args, complain, in_decl);
11524 return build_nt (COMPONENT_REF, object, name, NULL_TREE);
11530 case TRUNC_DIV_EXPR:
11531 case CEIL_DIV_EXPR:
11532 case FLOOR_DIV_EXPR:
11533 case ROUND_DIV_EXPR:
11534 case EXACT_DIV_EXPR:
11538 case TRUNC_MOD_EXPR:
11539 case FLOOR_MOD_EXPR:
11540 case TRUTH_ANDIF_EXPR:
11541 case TRUTH_ORIF_EXPR:
11542 case TRUTH_AND_EXPR:
11543 case TRUTH_OR_EXPR:
11556 case COMPOUND_EXPR:
11559 case PREDECREMENT_EXPR:
11560 case PREINCREMENT_EXPR:
11561 case POSTDECREMENT_EXPR:
11562 case POSTINCREMENT_EXPR:
11564 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11565 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
11568 return build_qualified_name (/*type=*/NULL_TREE,
11569 tsubst_copy (TREE_OPERAND (t, 0),
11570 args, complain, in_decl),
11571 tsubst_copy (TREE_OPERAND (t, 1),
11572 args, complain, in_decl),
11573 QUALIFIED_NAME_IS_TEMPLATE (t));
11578 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11579 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
11580 NULL_TREE, NULL_TREE);
11584 int n = VL_EXP_OPERAND_LENGTH (t);
11585 tree result = build_vl_exp (CALL_EXPR, n);
11587 for (i = 0; i < n; i++)
11588 TREE_OPERAND (t, i) = tsubst_copy (TREE_OPERAND (t, i), args,
11589 complain, in_decl);
11595 case PSEUDO_DTOR_EXPR:
11598 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11599 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
11600 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
11601 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
11608 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11609 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
11610 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
11611 NEW_EXPR_USE_GLOBAL (r) = NEW_EXPR_USE_GLOBAL (t);
11618 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11619 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
11620 DELETE_EXPR_USE_GLOBAL (r) = DELETE_EXPR_USE_GLOBAL (t);
11621 DELETE_EXPR_USE_VEC (r) = DELETE_EXPR_USE_VEC (t);
11625 case TEMPLATE_ID_EXPR:
11627 /* Substituted template arguments */
11628 tree fn = TREE_OPERAND (t, 0);
11629 tree targs = TREE_OPERAND (t, 1);
11631 fn = tsubst_copy (fn, args, complain, in_decl);
11633 targs = tsubst_template_args (targs, args, complain, in_decl);
11635 return lookup_template_function (fn, targs);
11640 tree purpose, value, chain;
11642 if (t == void_list_node)
11645 purpose = TREE_PURPOSE (t);
11647 purpose = tsubst_copy (purpose, args, complain, in_decl);
11648 value = TREE_VALUE (t);
11650 value = tsubst_copy (value, args, complain, in_decl);
11651 chain = TREE_CHAIN (t);
11652 if (chain && chain != void_type_node)
11653 chain = tsubst_copy (chain, args, complain, in_decl);
11654 if (purpose == TREE_PURPOSE (t)
11655 && value == TREE_VALUE (t)
11656 && chain == TREE_CHAIN (t))
11658 return tree_cons (purpose, value, chain);
11663 case ENUMERAL_TYPE:
11665 case TEMPLATE_TYPE_PARM:
11666 case TEMPLATE_TEMPLATE_PARM:
11667 case BOUND_TEMPLATE_TEMPLATE_PARM:
11668 case TEMPLATE_PARM_INDEX:
11670 case REFERENCE_TYPE:
11672 case FUNCTION_TYPE:
11675 case TYPENAME_TYPE:
11676 case UNBOUND_CLASS_TEMPLATE:
11678 case DECLTYPE_TYPE:
11680 return tsubst (t, args, complain, in_decl);
11682 case IDENTIFIER_NODE:
11683 if (IDENTIFIER_TYPENAME_P (t))
11685 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
11686 return mangle_conv_op_name_for_type (new_type);
11692 /* This is handled by tsubst_copy_and_build. */
11693 gcc_unreachable ();
11696 return build_x_va_arg (tsubst_copy (TREE_OPERAND (t, 0), args, complain,
11698 tsubst (TREE_TYPE (t), args, complain, in_decl));
11700 case CLEANUP_POINT_EXPR:
11701 /* We shouldn't have built any of these during initial template
11702 generation. Instead, they should be built during instantiation
11703 in response to the saved STMT_IS_FULL_EXPR_P setting. */
11704 gcc_unreachable ();
11708 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
11709 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11710 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
11711 PTRMEM_OK_P (r) = PTRMEM_OK_P (t);
11712 mark_used (TREE_OPERAND (r, 1));
11715 case EXPR_PACK_EXPANSION:
11716 error ("invalid use of pack expansion expression");
11717 return error_mark_node;
11719 case NONTYPE_ARGUMENT_PACK:
11720 error ("use %<...%> to expand argument pack");
11721 return error_mark_node;
11728 /* Instantiate any typedefs in the type. */
11729 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
11730 r = fold_convert (type, t);
11731 gcc_assert (TREE_CODE (r) == code);
11736 /* These can sometimes show up in a partial instantiation, but never
11737 involve template parms. */
11738 gcc_assert (!uses_template_parms (t));
11742 /* We shouldn't get here, but keep going if !ENABLE_CHECKING. */
11743 gcc_checking_assert (false);
11748 /* Like tsubst_copy, but specifically for OpenMP clauses. */
11751 tsubst_omp_clauses (tree clauses, tree args, tsubst_flags_t complain,
11754 tree new_clauses = NULL, nc, oc;
11756 for (oc = clauses; oc ; oc = OMP_CLAUSE_CHAIN (oc))
11758 nc = copy_node (oc);
11759 OMP_CLAUSE_CHAIN (nc) = new_clauses;
11762 switch (OMP_CLAUSE_CODE (nc))
11764 case OMP_CLAUSE_LASTPRIVATE:
11765 if (OMP_CLAUSE_LASTPRIVATE_STMT (oc))
11767 OMP_CLAUSE_LASTPRIVATE_STMT (nc) = push_stmt_list ();
11768 tsubst_expr (OMP_CLAUSE_LASTPRIVATE_STMT (oc), args, complain,
11769 in_decl, /*integral_constant_expression_p=*/false);
11770 OMP_CLAUSE_LASTPRIVATE_STMT (nc)
11771 = pop_stmt_list (OMP_CLAUSE_LASTPRIVATE_STMT (nc));
11774 case OMP_CLAUSE_PRIVATE:
11775 case OMP_CLAUSE_SHARED:
11776 case OMP_CLAUSE_FIRSTPRIVATE:
11777 case OMP_CLAUSE_REDUCTION:
11778 case OMP_CLAUSE_COPYIN:
11779 case OMP_CLAUSE_COPYPRIVATE:
11780 case OMP_CLAUSE_IF:
11781 case OMP_CLAUSE_NUM_THREADS:
11782 case OMP_CLAUSE_SCHEDULE:
11783 case OMP_CLAUSE_COLLAPSE:
11784 OMP_CLAUSE_OPERAND (nc, 0)
11785 = tsubst_expr (OMP_CLAUSE_OPERAND (oc, 0), args, complain,
11786 in_decl, /*integral_constant_expression_p=*/false);
11788 case OMP_CLAUSE_NOWAIT:
11789 case OMP_CLAUSE_ORDERED:
11790 case OMP_CLAUSE_DEFAULT:
11791 case OMP_CLAUSE_UNTIED:
11794 gcc_unreachable ();
11798 return finish_omp_clauses (nreverse (new_clauses));
11801 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
11804 tsubst_copy_asm_operands (tree t, tree args, tsubst_flags_t complain,
11807 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
11809 tree purpose, value, chain;
11814 if (TREE_CODE (t) != TREE_LIST)
11815 return tsubst_copy_and_build (t, args, complain, in_decl,
11816 /*function_p=*/false,
11817 /*integral_constant_expression_p=*/false);
11819 if (t == void_list_node)
11822 purpose = TREE_PURPOSE (t);
11824 purpose = RECUR (purpose);
11825 value = TREE_VALUE (t);
11826 if (value && TREE_CODE (value) != LABEL_DECL)
11827 value = RECUR (value);
11828 chain = TREE_CHAIN (t);
11829 if (chain && chain != void_type_node)
11830 chain = RECUR (chain);
11831 return tree_cons (purpose, value, chain);
11835 /* Substitute one OMP_FOR iterator. */
11838 tsubst_omp_for_iterator (tree t, int i, tree declv, tree initv,
11839 tree condv, tree incrv, tree *clauses,
11840 tree args, tsubst_flags_t complain, tree in_decl,
11841 bool integral_constant_expression_p)
11843 #define RECUR(NODE) \
11844 tsubst_expr ((NODE), args, complain, in_decl, \
11845 integral_constant_expression_p)
11846 tree decl, init, cond, incr, auto_node;
11848 init = TREE_VEC_ELT (OMP_FOR_INIT (t), i);
11849 gcc_assert (TREE_CODE (init) == MODIFY_EXPR);
11850 decl = RECUR (TREE_OPERAND (init, 0));
11851 init = TREE_OPERAND (init, 1);
11852 auto_node = type_uses_auto (TREE_TYPE (decl));
11853 if (auto_node && init)
11855 tree init_expr = init;
11856 if (TREE_CODE (init_expr) == DECL_EXPR)
11857 init_expr = DECL_INITIAL (DECL_EXPR_DECL (init_expr));
11858 init_expr = RECUR (init_expr);
11860 = do_auto_deduction (TREE_TYPE (decl), init_expr, auto_node);
11862 gcc_assert (!type_dependent_expression_p (decl));
11864 if (!CLASS_TYPE_P (TREE_TYPE (decl)))
11866 cond = RECUR (TREE_VEC_ELT (OMP_FOR_COND (t), i));
11867 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
11868 if (TREE_CODE (incr) == MODIFY_EXPR)
11869 incr = build_x_modify_expr (RECUR (TREE_OPERAND (incr, 0)), NOP_EXPR,
11870 RECUR (TREE_OPERAND (incr, 1)),
11873 incr = RECUR (incr);
11874 TREE_VEC_ELT (declv, i) = decl;
11875 TREE_VEC_ELT (initv, i) = init;
11876 TREE_VEC_ELT (condv, i) = cond;
11877 TREE_VEC_ELT (incrv, i) = incr;
11881 if (init && TREE_CODE (init) != DECL_EXPR)
11884 for (c = *clauses; c ; c = OMP_CLAUSE_CHAIN (c))
11886 if ((OMP_CLAUSE_CODE (c) == OMP_CLAUSE_PRIVATE
11887 || OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LASTPRIVATE)
11888 && OMP_CLAUSE_DECL (c) == decl)
11890 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_FIRSTPRIVATE
11891 && OMP_CLAUSE_DECL (c) == decl)
11892 error ("iteration variable %qD should not be firstprivate", decl);
11893 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_REDUCTION
11894 && OMP_CLAUSE_DECL (c) == decl)
11895 error ("iteration variable %qD should not be reduction", decl);
11899 c = build_omp_clause (input_location, OMP_CLAUSE_PRIVATE);
11900 OMP_CLAUSE_DECL (c) = decl;
11901 c = finish_omp_clauses (c);
11904 OMP_CLAUSE_CHAIN (c) = *clauses;
11909 cond = TREE_VEC_ELT (OMP_FOR_COND (t), i);
11910 if (COMPARISON_CLASS_P (cond))
11911 cond = build2 (TREE_CODE (cond), boolean_type_node,
11912 RECUR (TREE_OPERAND (cond, 0)),
11913 RECUR (TREE_OPERAND (cond, 1)));
11915 cond = RECUR (cond);
11916 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
11917 switch (TREE_CODE (incr))
11919 case PREINCREMENT_EXPR:
11920 case PREDECREMENT_EXPR:
11921 case POSTINCREMENT_EXPR:
11922 case POSTDECREMENT_EXPR:
11923 incr = build2 (TREE_CODE (incr), TREE_TYPE (decl),
11924 RECUR (TREE_OPERAND (incr, 0)), NULL_TREE);
11927 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
11928 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
11930 tree rhs = TREE_OPERAND (incr, 1);
11931 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
11932 RECUR (TREE_OPERAND (incr, 0)),
11933 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
11934 RECUR (TREE_OPERAND (rhs, 0)),
11935 RECUR (TREE_OPERAND (rhs, 1))));
11938 incr = RECUR (incr);
11941 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
11942 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
11944 tree lhs = RECUR (TREE_OPERAND (incr, 0));
11945 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl), lhs,
11946 build2 (TREE_CODE (TREE_OPERAND (incr, 1)),
11947 TREE_TYPE (decl), lhs,
11948 RECUR (TREE_OPERAND (incr, 2))));
11950 else if (TREE_CODE (TREE_OPERAND (incr, 1)) == NOP_EXPR
11951 && (TREE_CODE (TREE_OPERAND (incr, 2)) == PLUS_EXPR
11952 || (TREE_CODE (TREE_OPERAND (incr, 2)) == MINUS_EXPR)))
11954 tree rhs = TREE_OPERAND (incr, 2);
11955 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
11956 RECUR (TREE_OPERAND (incr, 0)),
11957 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
11958 RECUR (TREE_OPERAND (rhs, 0)),
11959 RECUR (TREE_OPERAND (rhs, 1))));
11962 incr = RECUR (incr);
11965 incr = RECUR (incr);
11969 TREE_VEC_ELT (declv, i) = decl;
11970 TREE_VEC_ELT (initv, i) = init;
11971 TREE_VEC_ELT (condv, i) = cond;
11972 TREE_VEC_ELT (incrv, i) = incr;
11976 /* Like tsubst_copy for expressions, etc. but also does semantic
11980 tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl,
11981 bool integral_constant_expression_p)
11983 #define RECUR(NODE) \
11984 tsubst_expr ((NODE), args, complain, in_decl, \
11985 integral_constant_expression_p)
11989 if (t == NULL_TREE || t == error_mark_node)
11992 if (EXPR_HAS_LOCATION (t))
11993 input_location = EXPR_LOCATION (t);
11994 if (STATEMENT_CODE_P (TREE_CODE (t)))
11995 current_stmt_tree ()->stmts_are_full_exprs_p = STMT_IS_FULL_EXPR_P (t);
11997 switch (TREE_CODE (t))
11999 case STATEMENT_LIST:
12001 tree_stmt_iterator i;
12002 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
12003 RECUR (tsi_stmt (i));
12007 case CTOR_INITIALIZER:
12008 finish_mem_initializers (tsubst_initializer_list
12009 (TREE_OPERAND (t, 0), args));
12013 finish_return_stmt (RECUR (TREE_OPERAND (t, 0)));
12017 tmp = RECUR (EXPR_STMT_EXPR (t));
12018 if (EXPR_STMT_STMT_EXPR_RESULT (t))
12019 finish_stmt_expr_expr (tmp, cur_stmt_expr);
12021 finish_expr_stmt (tmp);
12025 do_using_directive (USING_STMT_NAMESPACE (t));
12030 tree decl, pattern_decl;
12033 pattern_decl = decl = DECL_EXPR_DECL (t);
12034 if (TREE_CODE (decl) == LABEL_DECL)
12035 finish_label_decl (DECL_NAME (decl));
12036 else if (TREE_CODE (decl) == USING_DECL)
12038 tree scope = USING_DECL_SCOPE (decl);
12039 tree name = DECL_NAME (decl);
12042 scope = tsubst (scope, args, complain, in_decl);
12043 decl = lookup_qualified_name (scope, name,
12044 /*is_type_p=*/false,
12045 /*complain=*/false);
12046 if (decl == error_mark_node || TREE_CODE (decl) == TREE_LIST)
12047 qualified_name_lookup_error (scope, name, decl, input_location);
12049 do_local_using_decl (decl, scope, name);
12053 init = DECL_INITIAL (decl);
12054 decl = tsubst (decl, args, complain, in_decl);
12055 if (decl != error_mark_node)
12057 /* By marking the declaration as instantiated, we avoid
12058 trying to instantiate it. Since instantiate_decl can't
12059 handle local variables, and since we've already done
12060 all that needs to be done, that's the right thing to
12062 if (TREE_CODE (decl) == VAR_DECL)
12063 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
12064 if (TREE_CODE (decl) == VAR_DECL
12065 && ANON_AGGR_TYPE_P (TREE_TYPE (decl)))
12066 /* Anonymous aggregates are a special case. */
12067 finish_anon_union (decl);
12070 int const_init = false;
12071 maybe_push_decl (decl);
12072 if (TREE_CODE (decl) == VAR_DECL
12073 && DECL_PRETTY_FUNCTION_P (decl))
12075 /* For __PRETTY_FUNCTION__ we have to adjust the
12077 const char *const name
12078 = cxx_printable_name (current_function_decl, 2);
12079 init = cp_fname_init (name, &TREE_TYPE (decl));
12083 tree t = RECUR (init);
12087 /* If we had an initializer but it
12088 instantiated to nothing,
12089 value-initialize the object. This will
12090 only occur when the initializer was a
12091 pack expansion where the parameter packs
12092 used in that expansion were of length
12094 init = build_value_init (TREE_TYPE (decl),
12096 if (TREE_CODE (init) == AGGR_INIT_EXPR)
12097 init = get_target_expr (init);
12103 if (TREE_CODE (decl) == VAR_DECL)
12104 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
12106 cp_finish_decl (decl, init, const_init, NULL_TREE, 0);
12111 /* A DECL_EXPR can also be used as an expression, in the condition
12112 clause of an if/for/while construct. */
12117 stmt = begin_for_stmt (NULL_TREE, NULL_TREE);
12118 RECUR (FOR_INIT_STMT (t));
12119 finish_for_init_stmt (stmt);
12120 tmp = RECUR (FOR_COND (t));
12121 finish_for_cond (tmp, stmt);
12122 tmp = RECUR (FOR_EXPR (t));
12123 finish_for_expr (tmp, stmt);
12124 RECUR (FOR_BODY (t));
12125 finish_for_stmt (stmt);
12128 case RANGE_FOR_STMT:
12131 stmt = begin_for_stmt (NULL_TREE, NULL_TREE);
12132 decl = RANGE_FOR_DECL (t);
12133 decl = tsubst (decl, args, complain, in_decl);
12134 maybe_push_decl (decl);
12135 expr = RECUR (RANGE_FOR_EXPR (t));
12136 stmt = cp_convert_range_for (stmt, decl, expr);
12137 RECUR (RANGE_FOR_BODY (t));
12138 finish_for_stmt (stmt);
12143 stmt = begin_while_stmt ();
12144 tmp = RECUR (WHILE_COND (t));
12145 finish_while_stmt_cond (tmp, stmt);
12146 RECUR (WHILE_BODY (t));
12147 finish_while_stmt (stmt);
12151 stmt = begin_do_stmt ();
12152 RECUR (DO_BODY (t));
12153 finish_do_body (stmt);
12154 tmp = RECUR (DO_COND (t));
12155 finish_do_stmt (tmp, stmt);
12159 stmt = begin_if_stmt ();
12160 tmp = RECUR (IF_COND (t));
12161 finish_if_stmt_cond (tmp, stmt);
12162 RECUR (THEN_CLAUSE (t));
12163 finish_then_clause (stmt);
12165 if (ELSE_CLAUSE (t))
12167 begin_else_clause (stmt);
12168 RECUR (ELSE_CLAUSE (t));
12169 finish_else_clause (stmt);
12172 finish_if_stmt (stmt);
12176 if (BIND_EXPR_BODY_BLOCK (t))
12177 stmt = begin_function_body ();
12179 stmt = begin_compound_stmt (BIND_EXPR_TRY_BLOCK (t)
12180 ? BCS_TRY_BLOCK : 0);
12182 RECUR (BIND_EXPR_BODY (t));
12184 if (BIND_EXPR_BODY_BLOCK (t))
12185 finish_function_body (stmt);
12187 finish_compound_stmt (stmt);
12191 finish_break_stmt ();
12194 case CONTINUE_STMT:
12195 finish_continue_stmt ();
12199 stmt = begin_switch_stmt ();
12200 tmp = RECUR (SWITCH_STMT_COND (t));
12201 finish_switch_cond (tmp, stmt);
12202 RECUR (SWITCH_STMT_BODY (t));
12203 finish_switch_stmt (stmt);
12206 case CASE_LABEL_EXPR:
12207 finish_case_label (EXPR_LOCATION (t),
12208 RECUR (CASE_LOW (t)),
12209 RECUR (CASE_HIGH (t)));
12214 tree decl = LABEL_EXPR_LABEL (t);
12217 label = finish_label_stmt (DECL_NAME (decl));
12218 if (DECL_ATTRIBUTES (decl) != NULL_TREE)
12219 cplus_decl_attributes (&label, DECL_ATTRIBUTES (decl), 0);
12224 tmp = GOTO_DESTINATION (t);
12225 if (TREE_CODE (tmp) != LABEL_DECL)
12226 /* Computed goto's must be tsubst'd into. On the other hand,
12227 non-computed gotos must not be; the identifier in question
12228 will have no binding. */
12231 tmp = DECL_NAME (tmp);
12232 finish_goto_stmt (tmp);
12236 tmp = finish_asm_stmt
12237 (ASM_VOLATILE_P (t),
12238 RECUR (ASM_STRING (t)),
12239 tsubst_copy_asm_operands (ASM_OUTPUTS (t), args, complain, in_decl),
12240 tsubst_copy_asm_operands (ASM_INPUTS (t), args, complain, in_decl),
12241 tsubst_copy_asm_operands (ASM_CLOBBERS (t), args, complain, in_decl),
12242 tsubst_copy_asm_operands (ASM_LABELS (t), args, complain, in_decl));
12244 tree asm_expr = tmp;
12245 if (TREE_CODE (asm_expr) == CLEANUP_POINT_EXPR)
12246 asm_expr = TREE_OPERAND (asm_expr, 0);
12247 ASM_INPUT_P (asm_expr) = ASM_INPUT_P (t);
12254 stmt = begin_try_block ();
12255 RECUR (TRY_STMTS (t));
12256 finish_cleanup_try_block (stmt);
12257 finish_cleanup (RECUR (TRY_HANDLERS (t)), stmt);
12261 tree compound_stmt = NULL_TREE;
12263 if (FN_TRY_BLOCK_P (t))
12264 stmt = begin_function_try_block (&compound_stmt);
12266 stmt = begin_try_block ();
12268 RECUR (TRY_STMTS (t));
12270 if (FN_TRY_BLOCK_P (t))
12271 finish_function_try_block (stmt);
12273 finish_try_block (stmt);
12275 RECUR (TRY_HANDLERS (t));
12276 if (FN_TRY_BLOCK_P (t))
12277 finish_function_handler_sequence (stmt, compound_stmt);
12279 finish_handler_sequence (stmt);
12285 tree decl = HANDLER_PARMS (t);
12289 decl = tsubst (decl, args, complain, in_decl);
12290 /* Prevent instantiate_decl from trying to instantiate
12291 this variable. We've already done all that needs to be
12293 if (decl != error_mark_node)
12294 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
12296 stmt = begin_handler ();
12297 finish_handler_parms (decl, stmt);
12298 RECUR (HANDLER_BODY (t));
12299 finish_handler (stmt);
12304 tsubst (TREE_TYPE (t), args, complain, NULL_TREE);
12307 case STATIC_ASSERT:
12310 tsubst_expr (STATIC_ASSERT_CONDITION (t),
12313 /*integral_constant_expression_p=*/true);
12314 finish_static_assert (condition,
12315 STATIC_ASSERT_MESSAGE (t),
12316 STATIC_ASSERT_SOURCE_LOCATION (t),
12317 /*member_p=*/false);
12322 tmp = tsubst_omp_clauses (OMP_PARALLEL_CLAUSES (t),
12323 args, complain, in_decl);
12324 stmt = begin_omp_parallel ();
12325 RECUR (OMP_PARALLEL_BODY (t));
12326 OMP_PARALLEL_COMBINED (finish_omp_parallel (tmp, stmt))
12327 = OMP_PARALLEL_COMBINED (t);
12331 tmp = tsubst_omp_clauses (OMP_TASK_CLAUSES (t),
12332 args, complain, in_decl);
12333 stmt = begin_omp_task ();
12334 RECUR (OMP_TASK_BODY (t));
12335 finish_omp_task (tmp, stmt);
12340 tree clauses, body, pre_body;
12341 tree declv, initv, condv, incrv;
12344 clauses = tsubst_omp_clauses (OMP_FOR_CLAUSES (t),
12345 args, complain, in_decl);
12346 declv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
12347 initv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
12348 condv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
12349 incrv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
12351 for (i = 0; i < TREE_VEC_LENGTH (OMP_FOR_INIT (t)); i++)
12352 tsubst_omp_for_iterator (t, i, declv, initv, condv, incrv,
12353 &clauses, args, complain, in_decl,
12354 integral_constant_expression_p);
12356 stmt = begin_omp_structured_block ();
12358 for (i = 0; i < TREE_VEC_LENGTH (initv); i++)
12359 if (TREE_VEC_ELT (initv, i) == NULL
12360 || TREE_CODE (TREE_VEC_ELT (initv, i)) != DECL_EXPR)
12361 TREE_VEC_ELT (initv, i) = RECUR (TREE_VEC_ELT (initv, i));
12362 else if (CLASS_TYPE_P (TREE_TYPE (TREE_VEC_ELT (initv, i))))
12364 tree init = RECUR (TREE_VEC_ELT (initv, i));
12365 gcc_assert (init == TREE_VEC_ELT (declv, i));
12366 TREE_VEC_ELT (initv, i) = NULL_TREE;
12370 tree decl_expr = TREE_VEC_ELT (initv, i);
12371 tree init = DECL_INITIAL (DECL_EXPR_DECL (decl_expr));
12372 gcc_assert (init != NULL);
12373 TREE_VEC_ELT (initv, i) = RECUR (init);
12374 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = NULL;
12376 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = init;
12379 pre_body = push_stmt_list ();
12380 RECUR (OMP_FOR_PRE_BODY (t));
12381 pre_body = pop_stmt_list (pre_body);
12383 body = push_stmt_list ();
12384 RECUR (OMP_FOR_BODY (t));
12385 body = pop_stmt_list (body);
12387 t = finish_omp_for (EXPR_LOCATION (t), declv, initv, condv, incrv,
12388 body, pre_body, clauses);
12390 add_stmt (finish_omp_structured_block (stmt));
12396 tmp = tsubst_omp_clauses (OMP_CLAUSES (t), args, complain, in_decl);
12397 stmt = push_stmt_list ();
12398 RECUR (OMP_BODY (t));
12399 stmt = pop_stmt_list (stmt);
12402 OMP_BODY (t) = stmt;
12403 OMP_CLAUSES (t) = tmp;
12411 stmt = push_stmt_list ();
12412 RECUR (OMP_BODY (t));
12413 stmt = pop_stmt_list (stmt);
12416 OMP_BODY (t) = stmt;
12421 gcc_assert (OMP_ATOMIC_DEPENDENT_P (t));
12423 tree op1 = TREE_OPERAND (t, 1);
12424 tree lhs = RECUR (TREE_OPERAND (op1, 0));
12425 tree rhs = RECUR (TREE_OPERAND (op1, 1));
12426 finish_omp_atomic (TREE_CODE (op1), lhs, rhs);
12430 case EXPR_PACK_EXPANSION:
12431 error ("invalid use of pack expansion expression");
12432 return error_mark_node;
12434 case NONTYPE_ARGUMENT_PACK:
12435 error ("use %<...%> to expand argument pack");
12436 return error_mark_node;
12439 gcc_assert (!STATEMENT_CODE_P (TREE_CODE (t)));
12441 return tsubst_copy_and_build (t, args, complain, in_decl,
12442 /*function_p=*/false,
12443 integral_constant_expression_p);
12450 /* T is a postfix-expression that is not being used in a function
12451 call. Return the substituted version of T. */
12454 tsubst_non_call_postfix_expression (tree t, tree args,
12455 tsubst_flags_t complain,
12458 if (TREE_CODE (t) == SCOPE_REF)
12459 t = tsubst_qualified_id (t, args, complain, in_decl,
12460 /*done=*/false, /*address_p=*/false);
12462 t = tsubst_copy_and_build (t, args, complain, in_decl,
12463 /*function_p=*/false,
12464 /*integral_constant_expression_p=*/false);
12469 /* Like tsubst but deals with expressions and performs semantic
12470 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
12473 tsubst_copy_and_build (tree t,
12475 tsubst_flags_t complain,
12478 bool integral_constant_expression_p)
12480 #define RECUR(NODE) \
12481 tsubst_copy_and_build (NODE, args, complain, in_decl, \
12482 /*function_p=*/false, \
12483 integral_constant_expression_p)
12487 if (t == NULL_TREE || t == error_mark_node)
12490 switch (TREE_CODE (t))
12494 /* Fall through. */
12495 case IDENTIFIER_NODE:
12499 bool non_integral_constant_expression_p;
12500 const char *error_msg;
12502 if (IDENTIFIER_TYPENAME_P (t))
12504 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12505 t = mangle_conv_op_name_for_type (new_type);
12508 /* Look up the name. */
12509 decl = lookup_name (t);
12511 /* By convention, expressions use ERROR_MARK_NODE to indicate
12512 failure, not NULL_TREE. */
12513 if (decl == NULL_TREE)
12514 decl = error_mark_node;
12516 decl = finish_id_expression (t, decl, NULL_TREE,
12518 integral_constant_expression_p,
12519 /*allow_non_integral_constant_expression_p=*/false,
12520 &non_integral_constant_expression_p,
12521 /*template_p=*/false,
12523 /*address_p=*/false,
12524 /*template_arg_p=*/false,
12529 if (!function_p && TREE_CODE (decl) == IDENTIFIER_NODE)
12530 decl = unqualified_name_lookup_error (decl);
12534 case TEMPLATE_ID_EXPR:
12537 tree templ = RECUR (TREE_OPERAND (t, 0));
12538 tree targs = TREE_OPERAND (t, 1);
12541 targs = tsubst_template_args (targs, args, complain, in_decl);
12543 if (TREE_CODE (templ) == COMPONENT_REF)
12545 object = TREE_OPERAND (templ, 0);
12546 templ = TREE_OPERAND (templ, 1);
12549 object = NULL_TREE;
12550 templ = lookup_template_function (templ, targs);
12553 return build3 (COMPONENT_REF, TREE_TYPE (templ),
12554 object, templ, NULL_TREE);
12556 return baselink_for_fns (templ);
12561 tree r = RECUR (TREE_OPERAND (t, 0));
12563 if (REFERENCE_REF_P (t))
12565 /* A type conversion to reference type will be enclosed in
12566 such an indirect ref, but the substitution of the cast
12567 will have also added such an indirect ref. */
12568 if (TREE_CODE (TREE_TYPE (r)) == REFERENCE_TYPE)
12569 r = convert_from_reference (r);
12572 r = build_x_indirect_ref (r, RO_UNARY_STAR, complain);
12578 (tsubst (TREE_TYPE (t), args, complain, in_decl),
12579 RECUR (TREE_OPERAND (t, 0)));
12582 case REINTERPRET_CAST_EXPR:
12583 case CONST_CAST_EXPR:
12584 case DYNAMIC_CAST_EXPR:
12585 case STATIC_CAST_EXPR:
12590 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12591 if (integral_constant_expression_p
12592 && !cast_valid_in_integral_constant_expression_p (type))
12594 if (complain & tf_error)
12595 error ("a cast to a type other than an integral or "
12596 "enumeration type cannot appear in a constant-expression");
12597 return error_mark_node;
12600 op = RECUR (TREE_OPERAND (t, 0));
12602 switch (TREE_CODE (t))
12605 return build_functional_cast (type, op, complain);
12606 case REINTERPRET_CAST_EXPR:
12607 return build_reinterpret_cast (type, op, complain);
12608 case CONST_CAST_EXPR:
12609 return build_const_cast (type, op, complain);
12610 case DYNAMIC_CAST_EXPR:
12611 return build_dynamic_cast (type, op, complain);
12612 case STATIC_CAST_EXPR:
12613 return build_static_cast (type, op, complain);
12615 gcc_unreachable ();
12619 case POSTDECREMENT_EXPR:
12620 case POSTINCREMENT_EXPR:
12621 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
12622 args, complain, in_decl);
12623 return build_x_unary_op (TREE_CODE (t), op1, complain);
12625 case PREDECREMENT_EXPR:
12626 case PREINCREMENT_EXPR:
12630 case TRUTH_NOT_EXPR:
12631 case UNARY_PLUS_EXPR: /* Unary + */
12632 case REALPART_EXPR:
12633 case IMAGPART_EXPR:
12634 return build_x_unary_op (TREE_CODE (t), RECUR (TREE_OPERAND (t, 0)),
12638 op1 = TREE_OPERAND (t, 0);
12639 if (TREE_CODE (op1) == LABEL_DECL)
12640 return finish_label_address_expr (DECL_NAME (op1),
12641 EXPR_LOCATION (op1));
12642 if (TREE_CODE (op1) == SCOPE_REF)
12643 op1 = tsubst_qualified_id (op1, args, complain, in_decl,
12644 /*done=*/true, /*address_p=*/true);
12646 op1 = tsubst_non_call_postfix_expression (op1, args, complain,
12648 return build_x_unary_op (ADDR_EXPR, op1, complain);
12653 case TRUNC_DIV_EXPR:
12654 case CEIL_DIV_EXPR:
12655 case FLOOR_DIV_EXPR:
12656 case ROUND_DIV_EXPR:
12657 case EXACT_DIV_EXPR:
12661 case TRUNC_MOD_EXPR:
12662 case FLOOR_MOD_EXPR:
12663 case TRUTH_ANDIF_EXPR:
12664 case TRUTH_ORIF_EXPR:
12665 case TRUTH_AND_EXPR:
12666 case TRUTH_OR_EXPR:
12681 return build_x_binary_op
12683 RECUR (TREE_OPERAND (t, 0)),
12684 (TREE_NO_WARNING (TREE_OPERAND (t, 0))
12686 : TREE_CODE (TREE_OPERAND (t, 0))),
12687 RECUR (TREE_OPERAND (t, 1)),
12688 (TREE_NO_WARNING (TREE_OPERAND (t, 1))
12690 : TREE_CODE (TREE_OPERAND (t, 1))),
12691 /*overloaded_p=*/NULL,
12695 return tsubst_qualified_id (t, args, complain, in_decl, /*done=*/true,
12696 /*address_p=*/false);
12698 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
12699 args, complain, in_decl);
12700 return build_x_array_ref (op1, RECUR (TREE_OPERAND (t, 1)), complain);
12703 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
12704 return tsubst_copy (t, args, complain, in_decl);
12708 op1 = TREE_OPERAND (t, 0);
12711 /* When there are no ARGS, we are trying to evaluate a
12712 non-dependent expression from the parser. Trying to do
12713 the substitutions may not work. */
12715 op1 = TREE_TYPE (op1);
12719 ++cp_unevaluated_operand;
12720 ++c_inhibit_evaluation_warnings;
12721 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
12722 /*function_p=*/false,
12723 /*integral_constant_expression_p=*/false);
12724 --cp_unevaluated_operand;
12725 --c_inhibit_evaluation_warnings;
12728 return cxx_sizeof_or_alignof_type (op1, TREE_CODE (t),
12729 complain & tf_error);
12731 return cxx_sizeof_or_alignof_expr (op1, TREE_CODE (t),
12732 complain & tf_error);
12734 case AT_ENCODE_EXPR:
12736 op1 = TREE_OPERAND (t, 0);
12737 ++cp_unevaluated_operand;
12738 ++c_inhibit_evaluation_warnings;
12739 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
12740 /*function_p=*/false,
12741 /*integral_constant_expression_p=*/false);
12742 --cp_unevaluated_operand;
12743 --c_inhibit_evaluation_warnings;
12744 return objc_build_encode_expr (op1);
12747 case NOEXCEPT_EXPR:
12748 op1 = TREE_OPERAND (t, 0);
12749 ++cp_unevaluated_operand;
12750 ++c_inhibit_evaluation_warnings;
12751 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
12752 /*function_p=*/false,
12753 /*integral_constant_expression_p=*/false);
12754 --cp_unevaluated_operand;
12755 --c_inhibit_evaluation_warnings;
12756 return finish_noexcept_expr (op1, complain);
12760 tree r = build_x_modify_expr
12761 (RECUR (TREE_OPERAND (t, 0)),
12762 TREE_CODE (TREE_OPERAND (t, 1)),
12763 RECUR (TREE_OPERAND (t, 2)),
12765 /* TREE_NO_WARNING must be set if either the expression was
12766 parenthesized or it uses an operator such as >>= rather
12767 than plain assignment. In the former case, it was already
12768 set and must be copied. In the latter case,
12769 build_x_modify_expr sets it and it must not be reset
12771 if (TREE_NO_WARNING (t))
12772 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
12777 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
12778 args, complain, in_decl);
12779 /* Remember that there was a reference to this entity. */
12782 return build_x_arrow (op1);
12786 tree placement = RECUR (TREE_OPERAND (t, 0));
12787 tree init = RECUR (TREE_OPERAND (t, 3));
12788 VEC(tree,gc) *placement_vec;
12789 VEC(tree,gc) *init_vec;
12792 if (placement == NULL_TREE)
12793 placement_vec = NULL;
12796 placement_vec = make_tree_vector ();
12797 for (; placement != NULL_TREE; placement = TREE_CHAIN (placement))
12798 VEC_safe_push (tree, gc, placement_vec, TREE_VALUE (placement));
12801 /* If there was an initializer in the original tree, but it
12802 instantiated to an empty list, then we should pass a
12803 non-NULL empty vector to tell build_new that it was an
12804 empty initializer() rather than no initializer. This can
12805 only happen when the initializer is a pack expansion whose
12806 parameter packs are of length zero. */
12807 if (init == NULL_TREE && TREE_OPERAND (t, 3) == NULL_TREE)
12811 init_vec = make_tree_vector ();
12812 if (init == void_zero_node)
12813 gcc_assert (init_vec != NULL);
12816 for (; init != NULL_TREE; init = TREE_CHAIN (init))
12817 VEC_safe_push (tree, gc, init_vec, TREE_VALUE (init));
12821 ret = build_new (&placement_vec,
12822 tsubst (TREE_OPERAND (t, 1), args, complain, in_decl),
12823 RECUR (TREE_OPERAND (t, 2)),
12825 NEW_EXPR_USE_GLOBAL (t),
12828 if (placement_vec != NULL)
12829 release_tree_vector (placement_vec);
12830 if (init_vec != NULL)
12831 release_tree_vector (init_vec);
12837 return delete_sanity
12838 (RECUR (TREE_OPERAND (t, 0)),
12839 RECUR (TREE_OPERAND (t, 1)),
12840 DELETE_EXPR_USE_VEC (t),
12841 DELETE_EXPR_USE_GLOBAL (t));
12843 case COMPOUND_EXPR:
12844 return build_x_compound_expr (RECUR (TREE_OPERAND (t, 0)),
12845 RECUR (TREE_OPERAND (t, 1)),
12851 VEC(tree,gc) *call_args;
12852 unsigned int nargs, i;
12857 function = CALL_EXPR_FN (t);
12858 /* When we parsed the expression, we determined whether or
12859 not Koenig lookup should be performed. */
12860 koenig_p = KOENIG_LOOKUP_P (t);
12861 if (TREE_CODE (function) == SCOPE_REF)
12863 qualified_p = true;
12864 function = tsubst_qualified_id (function, args, complain, in_decl,
12866 /*address_p=*/false);
12870 if (TREE_CODE (function) == COMPONENT_REF)
12872 tree op = TREE_OPERAND (function, 1);
12874 qualified_p = (TREE_CODE (op) == SCOPE_REF
12875 || (BASELINK_P (op)
12876 && BASELINK_QUALIFIED_P (op)));
12879 qualified_p = false;
12881 function = tsubst_copy_and_build (function, args, complain,
12884 integral_constant_expression_p);
12886 if (BASELINK_P (function))
12887 qualified_p = true;
12890 nargs = call_expr_nargs (t);
12891 call_args = make_tree_vector ();
12892 for (i = 0; i < nargs; ++i)
12894 tree arg = CALL_EXPR_ARG (t, i);
12896 if (!PACK_EXPANSION_P (arg))
12897 VEC_safe_push (tree, gc, call_args,
12898 RECUR (CALL_EXPR_ARG (t, i)));
12901 /* Expand the pack expansion and push each entry onto
12903 arg = tsubst_pack_expansion (arg, args, complain, in_decl);
12904 if (TREE_CODE (arg) == TREE_VEC)
12906 unsigned int len, j;
12908 len = TREE_VEC_LENGTH (arg);
12909 for (j = 0; j < len; ++j)
12911 tree value = TREE_VEC_ELT (arg, j);
12912 if (value != NULL_TREE)
12913 value = convert_from_reference (value);
12914 VEC_safe_push (tree, gc, call_args, value);
12919 /* A partial substitution. Add one entry. */
12920 VEC_safe_push (tree, gc, call_args, arg);
12925 /* We do not perform argument-dependent lookup if normal
12926 lookup finds a non-function, in accordance with the
12927 expected resolution of DR 218. */
12929 && ((is_overloaded_fn (function)
12930 /* If lookup found a member function, the Koenig lookup is
12931 not appropriate, even if an unqualified-name was used
12932 to denote the function. */
12933 && !DECL_FUNCTION_MEMBER_P (get_first_fn (function)))
12934 || TREE_CODE (function) == IDENTIFIER_NODE)
12935 /* Only do this when substitution turns a dependent call
12936 into a non-dependent call. */
12937 && type_dependent_expression_p_push (t)
12938 && !any_type_dependent_arguments_p (call_args))
12939 function = perform_koenig_lookup (function, call_args, false);
12941 if (TREE_CODE (function) == IDENTIFIER_NODE)
12943 unqualified_name_lookup_error (function);
12944 release_tree_vector (call_args);
12945 return error_mark_node;
12948 /* Remember that there was a reference to this entity. */
12949 if (DECL_P (function))
12950 mark_used (function);
12952 if (TREE_CODE (function) == OFFSET_REF)
12953 ret = build_offset_ref_call_from_tree (function, &call_args);
12954 else if (TREE_CODE (function) == COMPONENT_REF)
12956 tree instance = TREE_OPERAND (function, 0);
12957 tree fn = TREE_OPERAND (function, 1);
12959 if (processing_template_decl
12960 && (type_dependent_expression_p (instance)
12961 || (!BASELINK_P (fn)
12962 && TREE_CODE (fn) != FIELD_DECL)
12963 || type_dependent_expression_p (fn)
12964 || any_type_dependent_arguments_p (call_args)))
12965 ret = build_nt_call_vec (function, call_args);
12966 else if (!BASELINK_P (fn))
12967 ret = finish_call_expr (function, &call_args,
12968 /*disallow_virtual=*/false,
12969 /*koenig_p=*/false,
12972 ret = (build_new_method_call
12974 &call_args, NULL_TREE,
12975 qualified_p ? LOOKUP_NONVIRTUAL : LOOKUP_NORMAL,
12980 ret = finish_call_expr (function, &call_args,
12981 /*disallow_virtual=*/qualified_p,
12985 release_tree_vector (call_args);
12991 return build_x_conditional_expr
12992 (RECUR (TREE_OPERAND (t, 0)),
12993 RECUR (TREE_OPERAND (t, 1)),
12994 RECUR (TREE_OPERAND (t, 2)),
12997 case PSEUDO_DTOR_EXPR:
12998 return finish_pseudo_destructor_expr
12999 (RECUR (TREE_OPERAND (t, 0)),
13000 RECUR (TREE_OPERAND (t, 1)),
13001 tsubst (TREE_OPERAND (t, 2), args, complain, in_decl));
13005 tree purpose, value, chain;
13007 if (t == void_list_node)
13010 if ((TREE_PURPOSE (t) && PACK_EXPANSION_P (TREE_PURPOSE (t)))
13011 || (TREE_VALUE (t) && PACK_EXPANSION_P (TREE_VALUE (t))))
13013 /* We have pack expansions, so expand those and
13014 create a new list out of it. */
13015 tree purposevec = NULL_TREE;
13016 tree valuevec = NULL_TREE;
13020 /* Expand the argument expressions. */
13021 if (TREE_PURPOSE (t))
13022 purposevec = tsubst_pack_expansion (TREE_PURPOSE (t), args,
13023 complain, in_decl);
13024 if (TREE_VALUE (t))
13025 valuevec = tsubst_pack_expansion (TREE_VALUE (t), args,
13026 complain, in_decl);
13028 /* Build the rest of the list. */
13029 chain = TREE_CHAIN (t);
13030 if (chain && chain != void_type_node)
13031 chain = RECUR (chain);
13033 /* Determine the number of arguments. */
13034 if (purposevec && TREE_CODE (purposevec) == TREE_VEC)
13036 len = TREE_VEC_LENGTH (purposevec);
13037 gcc_assert (!valuevec || len == TREE_VEC_LENGTH (valuevec));
13039 else if (TREE_CODE (valuevec) == TREE_VEC)
13040 len = TREE_VEC_LENGTH (valuevec);
13043 /* Since we only performed a partial substitution into
13044 the argument pack, we only return a single list
13046 if (purposevec == TREE_PURPOSE (t)
13047 && valuevec == TREE_VALUE (t)
13048 && chain == TREE_CHAIN (t))
13051 return tree_cons (purposevec, valuevec, chain);
13054 /* Convert the argument vectors into a TREE_LIST */
13058 /* Grab the Ith values. */
13060 purpose = purposevec ? TREE_VEC_ELT (purposevec, i)
13063 = valuevec ? convert_from_reference (TREE_VEC_ELT (valuevec, i))
13066 /* Build the list (backwards). */
13067 chain = tree_cons (purpose, value, chain);
13073 purpose = TREE_PURPOSE (t);
13075 purpose = RECUR (purpose);
13076 value = TREE_VALUE (t);
13078 value = RECUR (value);
13079 chain = TREE_CHAIN (t);
13080 if (chain && chain != void_type_node)
13081 chain = RECUR (chain);
13082 if (purpose == TREE_PURPOSE (t)
13083 && value == TREE_VALUE (t)
13084 && chain == TREE_CHAIN (t))
13086 return tree_cons (purpose, value, chain);
13089 case COMPONENT_REF:
13095 object = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
13096 args, complain, in_decl);
13097 /* Remember that there was a reference to this entity. */
13098 if (DECL_P (object))
13099 mark_used (object);
13100 object_type = TREE_TYPE (object);
13102 member = TREE_OPERAND (t, 1);
13103 if (BASELINK_P (member))
13104 member = tsubst_baselink (member,
13105 non_reference (TREE_TYPE (object)),
13106 args, complain, in_decl);
13108 member = tsubst_copy (member, args, complain, in_decl);
13109 if (member == error_mark_node)
13110 return error_mark_node;
13112 if (object_type && !CLASS_TYPE_P (object_type))
13114 if (SCALAR_TYPE_P (object_type))
13116 tree s = NULL_TREE;
13117 tree dtor = member;
13119 if (TREE_CODE (dtor) == SCOPE_REF)
13121 s = TREE_OPERAND (dtor, 0);
13122 dtor = TREE_OPERAND (dtor, 1);
13124 if (TREE_CODE (dtor) == BIT_NOT_EXPR)
13126 dtor = TREE_OPERAND (dtor, 0);
13128 return finish_pseudo_destructor_expr (object, s, dtor);
13132 else if (TREE_CODE (member) == SCOPE_REF
13133 && TREE_CODE (TREE_OPERAND (member, 1)) == TEMPLATE_ID_EXPR)
13138 /* Lookup the template functions now that we know what the
13140 tmpl = TREE_OPERAND (TREE_OPERAND (member, 1), 0);
13141 args = TREE_OPERAND (TREE_OPERAND (member, 1), 1);
13142 member = lookup_qualified_name (TREE_OPERAND (member, 0), tmpl,
13143 /*is_type_p=*/false,
13144 /*complain=*/false);
13145 if (BASELINK_P (member))
13147 BASELINK_FUNCTIONS (member)
13148 = build_nt (TEMPLATE_ID_EXPR, BASELINK_FUNCTIONS (member),
13150 member = (adjust_result_of_qualified_name_lookup
13151 (member, BINFO_TYPE (BASELINK_BINFO (member)),
13156 qualified_name_lookup_error (object_type, tmpl, member,
13158 return error_mark_node;
13161 else if (TREE_CODE (member) == SCOPE_REF
13162 && !CLASS_TYPE_P (TREE_OPERAND (member, 0))
13163 && TREE_CODE (TREE_OPERAND (member, 0)) != NAMESPACE_DECL)
13165 if (complain & tf_error)
13167 if (TYPE_P (TREE_OPERAND (member, 0)))
13168 error ("%qT is not a class or namespace",
13169 TREE_OPERAND (member, 0));
13171 error ("%qD is not a class or namespace",
13172 TREE_OPERAND (member, 0));
13174 return error_mark_node;
13176 else if (TREE_CODE (member) == FIELD_DECL)
13177 return finish_non_static_data_member (member, object, NULL_TREE);
13179 return finish_class_member_access_expr (object, member,
13180 /*template_p=*/false,
13186 (RECUR (TREE_OPERAND (t, 0)));
13190 VEC(constructor_elt,gc) *n;
13191 constructor_elt *ce;
13192 unsigned HOST_WIDE_INT idx;
13193 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
13194 bool process_index_p;
13196 bool need_copy_p = false;
13199 if (type == error_mark_node)
13200 return error_mark_node;
13202 /* digest_init will do the wrong thing if we let it. */
13203 if (type && TYPE_PTRMEMFUNC_P (type))
13206 /* We do not want to process the index of aggregate
13207 initializers as they are identifier nodes which will be
13208 looked up by digest_init. */
13209 process_index_p = !(type && MAYBE_CLASS_TYPE_P (type));
13211 n = VEC_copy (constructor_elt, gc, CONSTRUCTOR_ELTS (t));
13212 newlen = VEC_length (constructor_elt, n);
13213 FOR_EACH_VEC_ELT (constructor_elt, n, idx, ce)
13215 if (ce->index && process_index_p)
13216 ce->index = RECUR (ce->index);
13218 if (PACK_EXPANSION_P (ce->value))
13220 /* Substitute into the pack expansion. */
13221 ce->value = tsubst_pack_expansion (ce->value, args, complain,
13224 if (ce->value == error_mark_node)
13226 else if (TREE_VEC_LENGTH (ce->value) == 1)
13227 /* Just move the argument into place. */
13228 ce->value = TREE_VEC_ELT (ce->value, 0);
13231 /* Update the length of the final CONSTRUCTOR
13232 arguments vector, and note that we will need to
13234 newlen = newlen + TREE_VEC_LENGTH (ce->value) - 1;
13235 need_copy_p = true;
13239 ce->value = RECUR (ce->value);
13244 VEC(constructor_elt,gc) *old_n = n;
13246 n = VEC_alloc (constructor_elt, gc, newlen);
13247 FOR_EACH_VEC_ELT (constructor_elt, old_n, idx, ce)
13249 if (TREE_CODE (ce->value) == TREE_VEC)
13251 int i, len = TREE_VEC_LENGTH (ce->value);
13252 for (i = 0; i < len; ++i)
13253 CONSTRUCTOR_APPEND_ELT (n, 0,
13254 TREE_VEC_ELT (ce->value, i));
13257 CONSTRUCTOR_APPEND_ELT (n, 0, ce->value);
13261 r = build_constructor (init_list_type_node, n);
13262 CONSTRUCTOR_IS_DIRECT_INIT (r) = CONSTRUCTOR_IS_DIRECT_INIT (t);
13264 if (TREE_HAS_CONSTRUCTOR (t))
13265 return finish_compound_literal (type, r, complain);
13267 TREE_TYPE (r) = type;
13273 tree operand_0 = TREE_OPERAND (t, 0);
13274 if (TYPE_P (operand_0))
13276 operand_0 = tsubst (operand_0, args, complain, in_decl);
13277 return get_typeid (operand_0);
13281 operand_0 = RECUR (operand_0);
13282 return build_typeid (operand_0);
13293 tree r = tsubst_copy (t, args, complain, in_decl);
13295 if (TREE_CODE (TREE_TYPE (t)) != REFERENCE_TYPE)
13296 /* If the original type was a reference, we'll be wrapped in
13297 the appropriate INDIRECT_REF. */
13298 r = convert_from_reference (r);
13303 return build_x_va_arg (RECUR (TREE_OPERAND (t, 0)),
13304 tsubst (TREE_TYPE (t), args, complain, in_decl));
13306 case OFFSETOF_EXPR:
13307 return finish_offsetof (RECUR (TREE_OPERAND (t, 0)));
13311 tree type1 = tsubst_copy (TRAIT_EXPR_TYPE1 (t), args,
13312 complain, in_decl);
13314 tree type2 = TRAIT_EXPR_TYPE2 (t);
13316 type2 = tsubst_copy (type2, args, complain, in_decl);
13318 return finish_trait_expr (TRAIT_EXPR_KIND (t), type1, type2);
13323 tree old_stmt_expr = cur_stmt_expr;
13324 tree stmt_expr = begin_stmt_expr ();
13326 cur_stmt_expr = stmt_expr;
13327 tsubst_expr (STMT_EXPR_STMT (t), args, complain, in_decl,
13328 integral_constant_expression_p);
13329 stmt_expr = finish_stmt_expr (stmt_expr, false);
13330 cur_stmt_expr = old_stmt_expr;
13332 /* If the resulting list of expression statement is empty,
13333 fold it further into void_zero_node. */
13334 if (empty_expr_stmt_p (stmt_expr))
13335 stmt_expr = void_zero_node;
13341 t = tsubst_copy (t, args, complain, in_decl);
13342 /* As in finish_id_expression, we resolve enumeration constants
13343 to their underlying values. */
13344 if (TREE_CODE (t) == CONST_DECL)
13346 used_types_insert (TREE_TYPE (t));
13347 return DECL_INITIAL (t);
13353 tree r = build_lambda_expr ();
13355 tree type = tsubst (TREE_TYPE (t), args, complain, NULL_TREE);
13356 TREE_TYPE (r) = type;
13357 CLASSTYPE_LAMBDA_EXPR (type) = r;
13359 LAMBDA_EXPR_LOCATION (r)
13360 = LAMBDA_EXPR_LOCATION (t);
13361 LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (r)
13362 = LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (t);
13363 LAMBDA_EXPR_MUTABLE_P (r) = LAMBDA_EXPR_MUTABLE_P (t);
13364 LAMBDA_EXPR_DISCRIMINATOR (r)
13365 = (LAMBDA_EXPR_DISCRIMINATOR (t));
13366 LAMBDA_EXPR_CAPTURE_LIST (r)
13367 = RECUR (LAMBDA_EXPR_CAPTURE_LIST (t));
13368 LAMBDA_EXPR_THIS_CAPTURE (r)
13369 = RECUR (LAMBDA_EXPR_THIS_CAPTURE (t));
13370 LAMBDA_EXPR_EXTRA_SCOPE (r)
13371 = RECUR (LAMBDA_EXPR_EXTRA_SCOPE (t));
13373 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
13374 determine_visibility (TYPE_NAME (type));
13375 /* Now that we know visibility, instantiate the type so we have a
13376 declaration of the op() for later calls to lambda_function. */
13377 complete_type (type);
13379 type = tsubst (LAMBDA_EXPR_RETURN_TYPE (t), args, complain, in_decl);
13381 apply_lambda_return_type (r, type);
13383 return build_lambda_object (r);
13387 /* We can get here for a constant initializer of non-dependent type.
13388 FIXME stop folding in cp_parser_initializer_clause. */
13389 gcc_assert (TREE_CONSTANT (t));
13391 tree r = get_target_expr (RECUR (TARGET_EXPR_INITIAL (t)));
13392 TREE_CONSTANT (r) = true;
13397 /* Handle Objective-C++ constructs, if appropriate. */
13400 = objcp_tsubst_copy_and_build (t, args, complain,
13401 in_decl, /*function_p=*/false);
13405 return tsubst_copy (t, args, complain, in_decl);
13411 /* Verify that the instantiated ARGS are valid. For type arguments,
13412 make sure that the type's linkage is ok. For non-type arguments,
13413 make sure they are constants if they are integral or enumerations.
13414 Emit an error under control of COMPLAIN, and return TRUE on error. */
13417 check_instantiated_arg (tree tmpl, tree t, tsubst_flags_t complain)
13419 if (ARGUMENT_PACK_P (t))
13421 tree vec = ARGUMENT_PACK_ARGS (t);
13422 int len = TREE_VEC_LENGTH (vec);
13423 bool result = false;
13426 for (i = 0; i < len; ++i)
13427 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (vec, i), complain))
13431 else if (TYPE_P (t))
13433 /* [basic.link]: A name with no linkage (notably, the name
13434 of a class or enumeration declared in a local scope)
13435 shall not be used to declare an entity with linkage.
13436 This implies that names with no linkage cannot be used as
13439 DR 757 relaxes this restriction for C++0x. */
13440 tree nt = (cxx_dialect > cxx98 ? NULL_TREE
13441 : no_linkage_check (t, /*relaxed_p=*/false));
13445 /* DR 488 makes use of a type with no linkage cause
13446 type deduction to fail. */
13447 if (complain & tf_error)
13449 if (TYPE_ANONYMOUS_P (nt))
13450 error ("%qT is/uses anonymous type", t);
13452 error ("template argument for %qD uses local type %qT",
13457 /* In order to avoid all sorts of complications, we do not
13458 allow variably-modified types as template arguments. */
13459 else if (variably_modified_type_p (t, NULL_TREE))
13461 if (complain & tf_error)
13462 error ("%qT is a variably modified type", t);
13466 /* A non-type argument of integral or enumerated type must be a
13468 else if (TREE_TYPE (t)
13469 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t))
13470 && !TREE_CONSTANT (t))
13472 if (complain & tf_error)
13473 error ("integral expression %qE is not constant", t);
13480 check_instantiated_args (tree tmpl, tree args, tsubst_flags_t complain)
13482 int ix, len = DECL_NTPARMS (tmpl);
13483 bool result = false;
13485 for (ix = 0; ix != len; ix++)
13487 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (args, ix), complain))
13490 if (result && (complain & tf_error))
13491 error (" trying to instantiate %qD", tmpl);
13495 /* Instantiate the indicated variable or function template TMPL with
13496 the template arguments in TARG_PTR. */
13499 instantiate_template (tree tmpl, tree orig_args, tsubst_flags_t complain)
13501 tree targ_ptr = orig_args;
13505 HOST_WIDE_INT saved_processing_template_decl;
13507 if (tmpl == error_mark_node)
13508 return error_mark_node;
13510 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
13512 /* If this function is a clone, handle it specially. */
13513 if (DECL_CLONED_FUNCTION_P (tmpl))
13518 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
13519 DECL_CLONED_FUNCTION. */
13520 spec = instantiate_template (DECL_ABSTRACT_ORIGIN (tmpl),
13521 targ_ptr, complain);
13522 if (spec == error_mark_node)
13523 return error_mark_node;
13525 /* Look for the clone. */
13526 FOR_EACH_CLONE (clone, spec)
13527 if (DECL_NAME (clone) == DECL_NAME (tmpl))
13529 /* We should always have found the clone by now. */
13530 gcc_unreachable ();
13534 /* Check to see if we already have this specialization. */
13535 gen_tmpl = most_general_template (tmpl);
13536 if (tmpl != gen_tmpl)
13537 /* The TMPL is a partial instantiation. To get a full set of
13538 arguments we must add the arguments used to perform the
13539 partial instantiation. */
13540 targ_ptr = add_outermost_template_args (DECL_TI_ARGS (tmpl),
13543 /* It would be nice to avoid hashing here and then again in tsubst_decl,
13544 but it doesn't seem to be on the hot path. */
13545 spec = retrieve_specialization (gen_tmpl, targ_ptr, 0);
13547 gcc_assert (tmpl == gen_tmpl
13548 || ((fndecl = retrieve_specialization (tmpl, orig_args, 0))
13550 || fndecl == NULL_TREE);
13552 if (spec != NULL_TREE)
13555 if (check_instantiated_args (gen_tmpl, INNERMOST_TEMPLATE_ARGS (targ_ptr),
13557 return error_mark_node;
13559 /* We are building a FUNCTION_DECL, during which the access of its
13560 parameters and return types have to be checked. However this
13561 FUNCTION_DECL which is the desired context for access checking
13562 is not built yet. We solve this chicken-and-egg problem by
13563 deferring all checks until we have the FUNCTION_DECL. */
13564 push_deferring_access_checks (dk_deferred);
13566 /* Although PROCESSING_TEMPLATE_DECL may be true at this point
13567 (because, for example, we have encountered a non-dependent
13568 function call in the body of a template function and must now
13569 determine which of several overloaded functions will be called),
13570 within the instantiation itself we are not processing a
13572 saved_processing_template_decl = processing_template_decl;
13573 processing_template_decl = 0;
13574 /* Substitute template parameters to obtain the specialization. */
13575 fndecl = tsubst (DECL_TEMPLATE_RESULT (gen_tmpl),
13576 targ_ptr, complain, gen_tmpl);
13577 processing_template_decl = saved_processing_template_decl;
13578 if (fndecl == error_mark_node)
13579 return error_mark_node;
13581 /* Now we know the specialization, compute access previously
13583 push_access_scope (fndecl);
13585 /* Some typedefs referenced from within the template code need to be access
13586 checked at template instantiation time, i.e now. These types were
13587 added to the template at parsing time. Let's get those and perfom
13588 the acces checks then. */
13589 perform_typedefs_access_check (DECL_TEMPLATE_RESULT (tmpl), targ_ptr);
13590 perform_deferred_access_checks ();
13591 pop_access_scope (fndecl);
13592 pop_deferring_access_checks ();
13594 /* The DECL_TI_TEMPLATE should always be the immediate parent
13595 template, not the most general template. */
13596 DECL_TI_TEMPLATE (fndecl) = tmpl;
13598 /* If we've just instantiated the main entry point for a function,
13599 instantiate all the alternate entry points as well. We do this
13600 by cloning the instantiation of the main entry point, not by
13601 instantiating the template clones. */
13602 if (DECL_CHAIN (gen_tmpl) && DECL_CLONED_FUNCTION_P (DECL_CHAIN (gen_tmpl)))
13603 clone_function_decl (fndecl, /*update_method_vec_p=*/0);
13608 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
13609 NARGS elements of the arguments that are being used when calling
13610 it. TARGS is a vector into which the deduced template arguments
13613 Return zero for success, 2 for an incomplete match that doesn't resolve
13614 all the types, and 1 for complete failure. An error message will be
13615 printed only for an incomplete match.
13617 If FN is a conversion operator, or we are trying to produce a specific
13618 specialization, RETURN_TYPE is the return type desired.
13620 The EXPLICIT_TARGS are explicit template arguments provided via a
13623 The parameter STRICT is one of:
13626 We are deducing arguments for a function call, as in
13627 [temp.deduct.call].
13630 We are deducing arguments for a conversion function, as in
13631 [temp.deduct.conv].
13634 We are deducing arguments when doing an explicit instantiation
13635 as in [temp.explicit], when determining an explicit specialization
13636 as in [temp.expl.spec], or when taking the address of a function
13637 template, as in [temp.deduct.funcaddr]. */
13640 fn_type_unification (tree fn,
13641 tree explicit_targs,
13644 unsigned int nargs,
13646 unification_kind_t strict,
13652 bool incomplete_argument_packs_p = false;
13654 gcc_assert (TREE_CODE (fn) == TEMPLATE_DECL);
13656 fntype = TREE_TYPE (fn);
13657 if (explicit_targs)
13661 The specified template arguments must match the template
13662 parameters in kind (i.e., type, nontype, template), and there
13663 must not be more arguments than there are parameters;
13664 otherwise type deduction fails.
13666 Nontype arguments must match the types of the corresponding
13667 nontype template parameters, or must be convertible to the
13668 types of the corresponding nontype parameters as specified in
13669 _temp.arg.nontype_, otherwise type deduction fails.
13671 All references in the function type of the function template
13672 to the corresponding template parameters are replaced by the
13673 specified template argument values. If a substitution in a
13674 template parameter or in the function type of the function
13675 template results in an invalid type, type deduction fails. */
13676 tree tparms = DECL_INNERMOST_TEMPLATE_PARMS (fn);
13677 int i, len = TREE_VEC_LENGTH (tparms);
13678 tree converted_args;
13679 bool incomplete = false;
13681 if (explicit_targs == error_mark_node)
13685 = (coerce_template_parms (tparms, explicit_targs, NULL_TREE, tf_none,
13686 /*require_all_args=*/false,
13687 /*use_default_args=*/false));
13688 if (converted_args == error_mark_node)
13691 /* Substitute the explicit args into the function type. This is
13692 necessary so that, for instance, explicitly declared function
13693 arguments can match null pointed constants. If we were given
13694 an incomplete set of explicit args, we must not do semantic
13695 processing during substitution as we could create partial
13697 for (i = 0; i < len; i++)
13699 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
13700 bool parameter_pack = false;
13702 /* Dig out the actual parm. */
13703 if (TREE_CODE (parm) == TYPE_DECL
13704 || TREE_CODE (parm) == TEMPLATE_DECL)
13706 parm = TREE_TYPE (parm);
13707 parameter_pack = TEMPLATE_TYPE_PARAMETER_PACK (parm);
13709 else if (TREE_CODE (parm) == PARM_DECL)
13711 parm = DECL_INITIAL (parm);
13712 parameter_pack = TEMPLATE_PARM_PARAMETER_PACK (parm);
13715 if (parameter_pack)
13719 template_parm_level_and_index (parm, &level, &idx);
13721 /* Mark the argument pack as "incomplete". We could
13722 still deduce more arguments during unification.
13723 We remove this mark in type_unification_real. */
13724 targ = TMPL_ARG (converted_args, level, idx);
13727 ARGUMENT_PACK_INCOMPLETE_P(targ) = 1;
13728 ARGUMENT_PACK_EXPLICIT_ARGS (targ)
13729 = ARGUMENT_PACK_ARGS (targ);
13732 /* We have some incomplete argument packs. */
13733 incomplete_argument_packs_p = true;
13737 if (incomplete_argument_packs_p)
13738 /* Any substitution is guaranteed to be incomplete if there
13739 are incomplete argument packs, because we can still deduce
13743 incomplete = NUM_TMPL_ARGS (explicit_targs) != NUM_TMPL_ARGS (targs);
13745 processing_template_decl += incomplete;
13746 fntype = tsubst (fntype, converted_args, tf_none, NULL_TREE);
13747 processing_template_decl -= incomplete;
13749 if (fntype == error_mark_node)
13752 /* Place the explicitly specified arguments in TARGS. */
13753 for (i = NUM_TMPL_ARGS (converted_args); i--;)
13754 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (converted_args, i);
13757 /* Never do unification on the 'this' parameter. */
13758 parms = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (fntype));
13764 parms = tree_cons (NULL_TREE, TREE_TYPE (fntype), parms);
13765 new_args = XALLOCAVEC (tree, nargs + 1);
13766 new_args[0] = return_type;
13767 memcpy (new_args + 1, args, nargs * sizeof (tree));
13772 /* We allow incomplete unification without an error message here
13773 because the standard doesn't seem to explicitly prohibit it. Our
13774 callers must be ready to deal with unification failures in any
13776 result = type_unification_real (DECL_INNERMOST_TEMPLATE_PARMS (fn),
13777 targs, parms, args, nargs, /*subr=*/0,
13780 /* Now that we have bindings for all of the template arguments,
13781 ensure that the arguments deduced for the template template
13782 parameters have compatible template parameter lists. We cannot
13783 check this property before we have deduced all template
13784 arguments, because the template parameter types of a template
13785 template parameter might depend on prior template parameters
13786 deduced after the template template parameter. The following
13787 ill-formed example illustrates this issue:
13789 template<typename T, template<T> class C> void f(C<5>, T);
13791 template<int N> struct X {};
13794 f(X<5>(), 5l); // error: template argument deduction fails
13797 The template parameter list of 'C' depends on the template type
13798 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
13799 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
13800 time that we deduce 'C'. */
13802 && !template_template_parm_bindings_ok_p
13803 (DECL_INNERMOST_TEMPLATE_PARMS (fn), targs))
13807 /* All is well so far. Now, check:
13811 When all template arguments have been deduced, all uses of
13812 template parameters in nondeduced contexts are replaced with
13813 the corresponding deduced argument values. If the
13814 substitution results in an invalid type, as described above,
13815 type deduction fails. */
13817 tree substed = tsubst (TREE_TYPE (fn), targs, tf_none, NULL_TREE);
13818 if (substed == error_mark_node)
13821 /* If we're looking for an exact match, check that what we got
13822 is indeed an exact match. It might not be if some template
13823 parameters are used in non-deduced contexts. */
13824 if (strict == DEDUCE_EXACT)
13829 = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (substed));
13831 sarg = tree_cons (NULL_TREE, TREE_TYPE (substed), sarg);
13832 for (i = 0; i < nargs && sarg; ++i, sarg = TREE_CHAIN (sarg))
13833 if (!same_type_p (args[i], TREE_VALUE (sarg)))
13841 /* Adjust types before performing type deduction, as described in
13842 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
13843 sections are symmetric. PARM is the type of a function parameter
13844 or the return type of the conversion function. ARG is the type of
13845 the argument passed to the call, or the type of the value
13846 initialized with the result of the conversion function.
13847 ARG_EXPR is the original argument expression, which may be null. */
13850 maybe_adjust_types_for_deduction (unification_kind_t strict,
13864 /* Swap PARM and ARG throughout the remainder of this
13865 function; the handling is precisely symmetric since PARM
13866 will initialize ARG rather than vice versa. */
13874 /* Core issue #873: Do the DR606 thing (see below) for these cases,
13875 too, but here handle it by stripping the reference from PARM
13876 rather than by adding it to ARG. */
13877 if (TREE_CODE (*parm) == REFERENCE_TYPE
13878 && TYPE_REF_IS_RVALUE (*parm)
13879 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
13880 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
13881 && TREE_CODE (*arg) == REFERENCE_TYPE
13882 && !TYPE_REF_IS_RVALUE (*arg))
13883 *parm = TREE_TYPE (*parm);
13884 /* Nothing else to do in this case. */
13888 gcc_unreachable ();
13891 if (TREE_CODE (*parm) != REFERENCE_TYPE)
13893 /* [temp.deduct.call]
13895 If P is not a reference type:
13897 --If A is an array type, the pointer type produced by the
13898 array-to-pointer standard conversion (_conv.array_) is
13899 used in place of A for type deduction; otherwise,
13901 --If A is a function type, the pointer type produced by
13902 the function-to-pointer standard conversion
13903 (_conv.func_) is used in place of A for type deduction;
13906 --If A is a cv-qualified type, the top level
13907 cv-qualifiers of A's type are ignored for type
13909 if (TREE_CODE (*arg) == ARRAY_TYPE)
13910 *arg = build_pointer_type (TREE_TYPE (*arg));
13911 else if (TREE_CODE (*arg) == FUNCTION_TYPE)
13912 *arg = build_pointer_type (*arg);
13914 *arg = TYPE_MAIN_VARIANT (*arg);
13917 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
13918 of the form T&&, where T is a template parameter, and the argument
13919 is an lvalue, T is deduced as A& */
13920 if (TREE_CODE (*parm) == REFERENCE_TYPE
13921 && TYPE_REF_IS_RVALUE (*parm)
13922 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
13923 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
13924 && (arg_expr ? real_lvalue_p (arg_expr)
13925 /* try_one_overload doesn't provide an arg_expr, but
13926 functions are always lvalues. */
13927 : TREE_CODE (*arg) == FUNCTION_TYPE))
13928 *arg = build_reference_type (*arg);
13930 /* [temp.deduct.call]
13932 If P is a cv-qualified type, the top level cv-qualifiers
13933 of P's type are ignored for type deduction. If P is a
13934 reference type, the type referred to by P is used for
13936 *parm = TYPE_MAIN_VARIANT (*parm);
13937 if (TREE_CODE (*parm) == REFERENCE_TYPE)
13939 *parm = TREE_TYPE (*parm);
13940 result |= UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
13943 /* DR 322. For conversion deduction, remove a reference type on parm
13944 too (which has been swapped into ARG). */
13945 if (strict == DEDUCE_CONV && TREE_CODE (*arg) == REFERENCE_TYPE)
13946 *arg = TREE_TYPE (*arg);
13951 /* Most parms like fn_type_unification.
13953 If SUBR is 1, we're being called recursively (to unify the
13954 arguments of a function or method parameter of a function
13958 type_unification_real (tree tparms,
13962 unsigned int xnargs,
13964 unification_kind_t strict,
13967 tree parm, arg, arg_expr;
13969 int ntparms = TREE_VEC_LENGTH (tparms);
13971 int saw_undeduced = 0;
13974 unsigned int nargs;
13977 gcc_assert (TREE_CODE (tparms) == TREE_VEC);
13978 gcc_assert (xparms == NULL_TREE || TREE_CODE (xparms) == TREE_LIST);
13979 gcc_assert (ntparms > 0);
13981 /* Reset the number of non-defaulted template arguments contained
13983 NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs) = NULL_TREE;
13988 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL | UNIFY_ALLOW_MORE_CV_QUAL
13989 | UNIFY_ALLOW_DERIVED);
13993 sub_strict = UNIFY_ALLOW_LESS_CV_QUAL;
13997 sub_strict = UNIFY_ALLOW_NONE;
14001 gcc_unreachable ();
14010 while (parms && parms != void_list_node
14013 if (TREE_CODE (TREE_VALUE (parms)) == TYPE_PACK_EXPANSION)
14016 parm = TREE_VALUE (parms);
14017 parms = TREE_CHAIN (parms);
14022 if (arg == error_mark_node)
14024 if (arg == unknown_type_node)
14025 /* We can't deduce anything from this, but we might get all the
14026 template args from other function args. */
14029 /* Conversions will be performed on a function argument that
14030 corresponds with a function parameter that contains only
14031 non-deducible template parameters and explicitly specified
14032 template parameters. */
14033 if (!uses_template_parms (parm))
14038 type = TREE_TYPE (arg);
14042 if (same_type_p (parm, type))
14044 if (strict != DEDUCE_EXACT
14045 && can_convert_arg (parm, type, TYPE_P (arg) ? NULL_TREE : arg,
14054 gcc_assert (TREE_TYPE (arg) != NULL_TREE);
14055 if (type_unknown_p (arg))
14057 /* [temp.deduct.type]
14059 A template-argument can be deduced from a pointer to
14060 function or pointer to member function argument if
14061 the set of overloaded functions does not contain
14062 function templates and at most one of a set of
14063 overloaded functions provides a unique match. */
14064 if (resolve_overloaded_unification
14065 (tparms, targs, parm, arg, strict, sub_strict))
14071 arg = unlowered_expr_type (arg);
14072 if (arg == error_mark_node)
14077 int arg_strict = sub_strict;
14080 arg_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg,
14083 if (arg == init_list_type_node && arg_expr)
14085 if (unify (tparms, targs, parm, arg, arg_strict))
14092 && parms != void_list_node
14093 && TREE_CODE (TREE_VALUE (parms)) == TYPE_PACK_EXPANSION)
14095 /* Unify the remaining arguments with the pack expansion type. */
14097 tree parmvec = make_tree_vec (1);
14099 /* Allocate a TREE_VEC and copy in all of the arguments */
14100 argvec = make_tree_vec (nargs - ia);
14101 for (i = 0; ia < nargs; ++ia, ++i)
14102 TREE_VEC_ELT (argvec, i) = args[ia];
14104 /* Copy the parameter into parmvec. */
14105 TREE_VEC_ELT (parmvec, 0) = TREE_VALUE (parms);
14106 if (unify_pack_expansion (tparms, targs, parmvec, argvec, strict,
14107 /*call_args_p=*/true, /*subr=*/subr))
14110 /* Advance to the end of the list of parameters. */
14111 parms = TREE_CHAIN (parms);
14114 /* Fail if we've reached the end of the parm list, and more args
14115 are present, and the parm list isn't variadic. */
14116 if (ia < nargs && parms == void_list_node)
14118 /* Fail if parms are left and they don't have default values. */
14119 if (parms && parms != void_list_node
14120 && TREE_PURPOSE (parms) == NULL_TREE)
14125 /* Check to see if we need another pass before we start clearing
14126 ARGUMENT_PACK_INCOMPLETE_P. */
14127 for (i = 0; i < ntparms; i++)
14129 tree targ = TREE_VEC_ELT (targs, i);
14130 tree tparm = TREE_VEC_ELT (tparms, i);
14132 if (targ || tparm == error_mark_node)
14134 tparm = TREE_VALUE (tparm);
14136 /* If this is an undeduced nontype parameter that depends on
14137 a type parameter, try another pass; its type may have been
14138 deduced from a later argument than the one from which
14139 this parameter can be deduced. */
14140 if (TREE_CODE (tparm) == PARM_DECL
14141 && uses_template_parms (TREE_TYPE (tparm))
14142 && !saw_undeduced++)
14146 for (i = 0; i < ntparms; i++)
14148 tree targ = TREE_VEC_ELT (targs, i);
14149 tree tparm = TREE_VEC_ELT (tparms, i);
14151 /* Clear the "incomplete" flags on all argument packs now so that
14152 substituting them into later default arguments works. */
14153 if (targ && ARGUMENT_PACK_P (targ))
14155 ARGUMENT_PACK_INCOMPLETE_P (targ) = 0;
14156 ARGUMENT_PACK_EXPLICIT_ARGS (targ) = NULL_TREE;
14159 if (targ || tparm == error_mark_node)
14161 tparm = TREE_VALUE (tparm);
14163 /* Core issue #226 (C++0x) [temp.deduct]:
14165 If a template argument has not been deduced, its
14166 default template argument, if any, is used.
14168 When we are in C++98 mode, TREE_PURPOSE will either
14169 be NULL_TREE or ERROR_MARK_NODE, so we do not need
14170 to explicitly check cxx_dialect here. */
14171 if (TREE_PURPOSE (TREE_VEC_ELT (tparms, i)))
14173 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
14174 tree arg = TREE_PURPOSE (TREE_VEC_ELT (tparms, i));
14175 arg = tsubst_template_arg (arg, targs, tf_none, NULL_TREE);
14176 arg = convert_template_argument (parm, arg, targs, tf_none,
14178 if (arg == error_mark_node)
14182 TREE_VEC_ELT (targs, i) = arg;
14183 /* The position of the first default template argument,
14184 is also the number of non-defaulted arguments in TARGS.
14186 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs))
14187 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, i);
14192 /* If the type parameter is a parameter pack, then it will
14193 be deduced to an empty parameter pack. */
14194 if (template_parameter_pack_p (tparm))
14198 if (TREE_CODE (tparm) == TEMPLATE_PARM_INDEX)
14200 arg = make_node (NONTYPE_ARGUMENT_PACK);
14201 TREE_TYPE (arg) = TREE_TYPE (TEMPLATE_PARM_DECL (tparm));
14202 TREE_CONSTANT (arg) = 1;
14205 arg = cxx_make_type (TYPE_ARGUMENT_PACK);
14207 SET_ARGUMENT_PACK_ARGS (arg, make_tree_vec (0));
14209 TREE_VEC_ELT (targs, i) = arg;
14216 #ifdef ENABLE_CHECKING
14217 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs))
14218 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, TREE_VEC_LENGTH (targs));
14224 /* Subroutine of type_unification_real. Args are like the variables
14225 at the call site. ARG is an overloaded function (or template-id);
14226 we try deducing template args from each of the overloads, and if
14227 only one succeeds, we go with that. Modifies TARGS and returns
14228 true on success. */
14231 resolve_overloaded_unification (tree tparms,
14235 unification_kind_t strict,
14238 tree tempargs = copy_node (targs);
14240 tree goodfn = NULL_TREE;
14243 if (TREE_CODE (arg) == ADDR_EXPR)
14245 arg = TREE_OPERAND (arg, 0);
14251 if (TREE_CODE (arg) == COMPONENT_REF)
14252 /* Handle `&x' where `x' is some static or non-static member
14254 arg = TREE_OPERAND (arg, 1);
14256 if (TREE_CODE (arg) == OFFSET_REF)
14257 arg = TREE_OPERAND (arg, 1);
14259 /* Strip baselink information. */
14260 if (BASELINK_P (arg))
14261 arg = BASELINK_FUNCTIONS (arg);
14263 if (TREE_CODE (arg) == TEMPLATE_ID_EXPR)
14265 /* If we got some explicit template args, we need to plug them into
14266 the affected templates before we try to unify, in case the
14267 explicit args will completely resolve the templates in question. */
14269 tree expl_subargs = TREE_OPERAND (arg, 1);
14270 arg = TREE_OPERAND (arg, 0);
14272 for (; arg; arg = OVL_NEXT (arg))
14274 tree fn = OVL_CURRENT (arg);
14275 tree subargs, elem;
14277 if (TREE_CODE (fn) != TEMPLATE_DECL)
14280 ++processing_template_decl;
14281 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
14282 expl_subargs, /*check_ret=*/false);
14285 elem = tsubst (TREE_TYPE (fn), subargs, tf_none, NULL_TREE);
14286 if (try_one_overload (tparms, targs, tempargs, parm,
14287 elem, strict, sub_strict, addr_p)
14288 && (!goodfn || !decls_match (goodfn, elem)))
14294 --processing_template_decl;
14297 else if (TREE_CODE (arg) != OVERLOAD
14298 && TREE_CODE (arg) != FUNCTION_DECL)
14299 /* If ARG is, for example, "(0, &f)" then its type will be unknown
14300 -- but the deduction does not succeed because the expression is
14301 not just the function on its own. */
14304 for (; arg; arg = OVL_NEXT (arg))
14305 if (try_one_overload (tparms, targs, tempargs, parm,
14306 TREE_TYPE (OVL_CURRENT (arg)),
14307 strict, sub_strict, addr_p)
14308 && (!goodfn || !decls_match (goodfn, OVL_CURRENT (arg))))
14310 goodfn = OVL_CURRENT (arg);
14314 /* [temp.deduct.type] A template-argument can be deduced from a pointer
14315 to function or pointer to member function argument if the set of
14316 overloaded functions does not contain function templates and at most
14317 one of a set of overloaded functions provides a unique match.
14319 So if we found multiple possibilities, we return success but don't
14320 deduce anything. */
14324 int i = TREE_VEC_LENGTH (targs);
14326 if (TREE_VEC_ELT (tempargs, i))
14327 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (tempargs, i);
14335 /* Core DR 115: In contexts where deduction is done and fails, or in
14336 contexts where deduction is not done, if a template argument list is
14337 specified and it, along with any default template arguments, identifies
14338 a single function template specialization, then the template-id is an
14339 lvalue for the function template specialization. */
14342 resolve_nondeduced_context (tree orig_expr)
14344 tree expr, offset, baselink;
14347 if (!type_unknown_p (orig_expr))
14352 offset = NULL_TREE;
14353 baselink = NULL_TREE;
14355 if (TREE_CODE (expr) == ADDR_EXPR)
14357 expr = TREE_OPERAND (expr, 0);
14360 if (TREE_CODE (expr) == OFFSET_REF)
14363 expr = TREE_OPERAND (expr, 1);
14365 if (TREE_CODE (expr) == BASELINK)
14368 expr = BASELINK_FUNCTIONS (expr);
14371 if (TREE_CODE (expr) == TEMPLATE_ID_EXPR)
14374 tree goodfn = NULL_TREE;
14376 /* If we got some explicit template args, we need to plug them into
14377 the affected templates before we try to unify, in case the
14378 explicit args will completely resolve the templates in question. */
14380 tree expl_subargs = TREE_OPERAND (expr, 1);
14381 tree arg = TREE_OPERAND (expr, 0);
14382 tree badfn = NULL_TREE;
14383 tree badargs = NULL_TREE;
14385 for (; arg; arg = OVL_NEXT (arg))
14387 tree fn = OVL_CURRENT (arg);
14388 tree subargs, elem;
14390 if (TREE_CODE (fn) != TEMPLATE_DECL)
14393 ++processing_template_decl;
14394 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
14395 expl_subargs, /*check_ret=*/false);
14396 if (subargs && !any_dependent_template_arguments_p (subargs))
14398 elem = instantiate_template (fn, subargs, tf_none);
14399 if (elem == error_mark_node)
14404 else if (elem && (!goodfn || !decls_match (goodfn, elem)))
14410 --processing_template_decl;
14416 expr = build_baselink (BASELINK_BINFO (baselink),
14417 BASELINK_ACCESS_BINFO (baselink),
14418 expr, BASELINK_OPTYPE (baselink));
14422 = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (offset, 0)));
14423 expr = build_offset_ref (base, expr, addr);
14426 expr = cp_build_addr_expr (expr, tf_warning_or_error);
14429 else if (good == 0 && badargs)
14430 /* There were no good options and at least one bad one, so let the
14431 user know what the problem is. */
14432 instantiate_template (badfn, badargs, tf_warning_or_error);
14437 /* Subroutine of resolve_overloaded_unification; does deduction for a single
14438 overload. Fills TARGS with any deduced arguments, or error_mark_node if
14439 different overloads deduce different arguments for a given parm.
14440 ADDR_P is true if the expression for which deduction is being
14441 performed was of the form "& fn" rather than simply "fn".
14443 Returns 1 on success. */
14446 try_one_overload (tree tparms,
14451 unification_kind_t strict,
14459 /* [temp.deduct.type] A template-argument can be deduced from a pointer
14460 to function or pointer to member function argument if the set of
14461 overloaded functions does not contain function templates and at most
14462 one of a set of overloaded functions provides a unique match.
14464 So if this is a template, just return success. */
14466 if (uses_template_parms (arg))
14469 if (TREE_CODE (arg) == METHOD_TYPE)
14470 arg = build_ptrmemfunc_type (build_pointer_type (arg));
14472 arg = build_pointer_type (arg);
14474 sub_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg, NULL);
14476 /* We don't copy orig_targs for this because if we have already deduced
14477 some template args from previous args, unify would complain when we
14478 try to deduce a template parameter for the same argument, even though
14479 there isn't really a conflict. */
14480 nargs = TREE_VEC_LENGTH (targs);
14481 tempargs = make_tree_vec (nargs);
14483 if (unify (tparms, tempargs, parm, arg, sub_strict) != 0)
14486 /* First make sure we didn't deduce anything that conflicts with
14487 explicitly specified args. */
14488 for (i = nargs; i--; )
14490 tree elt = TREE_VEC_ELT (tempargs, i);
14491 tree oldelt = TREE_VEC_ELT (orig_targs, i);
14495 else if (uses_template_parms (elt))
14496 /* Since we're unifying against ourselves, we will fill in
14497 template args used in the function parm list with our own
14498 template parms. Discard them. */
14499 TREE_VEC_ELT (tempargs, i) = NULL_TREE;
14500 else if (oldelt && !template_args_equal (oldelt, elt))
14504 for (i = nargs; i--; )
14506 tree elt = TREE_VEC_ELT (tempargs, i);
14509 TREE_VEC_ELT (targs, i) = elt;
14515 /* PARM is a template class (perhaps with unbound template
14516 parameters). ARG is a fully instantiated type. If ARG can be
14517 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
14518 TARGS are as for unify. */
14521 try_class_unification (tree tparms, tree targs, tree parm, tree arg)
14523 tree copy_of_targs;
14525 if (!CLASSTYPE_TEMPLATE_INFO (arg)
14526 || (most_general_template (CLASSTYPE_TI_TEMPLATE (arg))
14527 != most_general_template (CLASSTYPE_TI_TEMPLATE (parm))))
14530 /* We need to make a new template argument vector for the call to
14531 unify. If we used TARGS, we'd clutter it up with the result of
14532 the attempted unification, even if this class didn't work out.
14533 We also don't want to commit ourselves to all the unifications
14534 we've already done, since unification is supposed to be done on
14535 an argument-by-argument basis. In other words, consider the
14536 following pathological case:
14538 template <int I, int J, int K>
14541 template <int I, int J>
14542 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
14544 template <int I, int J, int K>
14545 void f(S<I, J, K>, S<I, I, I>);
14554 Now, by the time we consider the unification involving `s2', we
14555 already know that we must have `f<0, 0, 0>'. But, even though
14556 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
14557 because there are two ways to unify base classes of S<0, 1, 2>
14558 with S<I, I, I>. If we kept the already deduced knowledge, we
14559 would reject the possibility I=1. */
14560 copy_of_targs = make_tree_vec (TREE_VEC_LENGTH (targs));
14562 /* If unification failed, we're done. */
14563 if (unify (tparms, copy_of_targs, CLASSTYPE_TI_ARGS (parm),
14564 CLASSTYPE_TI_ARGS (arg), UNIFY_ALLOW_NONE))
14570 /* Given a template type PARM and a class type ARG, find the unique
14571 base type in ARG that is an instance of PARM. We do not examine
14572 ARG itself; only its base-classes. If there is not exactly one
14573 appropriate base class, return NULL_TREE. PARM may be the type of
14574 a partial specialization, as well as a plain template type. Used
14578 get_template_base (tree tparms, tree targs, tree parm, tree arg)
14580 tree rval = NULL_TREE;
14583 gcc_assert (RECORD_OR_UNION_CODE_P (TREE_CODE (arg)));
14585 binfo = TYPE_BINFO (complete_type (arg));
14587 /* The type could not be completed. */
14590 /* Walk in inheritance graph order. The search order is not
14591 important, and this avoids multiple walks of virtual bases. */
14592 for (binfo = TREE_CHAIN (binfo); binfo; binfo = TREE_CHAIN (binfo))
14594 tree r = try_class_unification (tparms, targs, parm, BINFO_TYPE (binfo));
14598 /* If there is more than one satisfactory baseclass, then:
14602 If they yield more than one possible deduced A, the type
14606 if (rval && !same_type_p (r, rval))
14616 /* Returns the level of DECL, which declares a template parameter. */
14619 template_decl_level (tree decl)
14621 switch (TREE_CODE (decl))
14624 case TEMPLATE_DECL:
14625 return TEMPLATE_TYPE_LEVEL (TREE_TYPE (decl));
14628 return TEMPLATE_PARM_LEVEL (DECL_INITIAL (decl));
14631 gcc_unreachable ();
14636 /* Decide whether ARG can be unified with PARM, considering only the
14637 cv-qualifiers of each type, given STRICT as documented for unify.
14638 Returns nonzero iff the unification is OK on that basis. */
14641 check_cv_quals_for_unify (int strict, tree arg, tree parm)
14643 int arg_quals = cp_type_quals (arg);
14644 int parm_quals = cp_type_quals (parm);
14646 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
14647 && !(strict & UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
14649 /* Although a CVR qualifier is ignored when being applied to a
14650 substituted template parameter ([8.3.2]/1 for example), that
14651 does not allow us to unify "const T" with "int&" because both
14652 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
14653 It is ok when we're allowing additional CV qualifiers
14654 at the outer level [14.8.2.1]/3,1st bullet. */
14655 if ((TREE_CODE (arg) == REFERENCE_TYPE
14656 || TREE_CODE (arg) == FUNCTION_TYPE
14657 || TREE_CODE (arg) == METHOD_TYPE)
14658 && (parm_quals & (TYPE_QUAL_CONST | TYPE_QUAL_VOLATILE)))
14661 if ((!POINTER_TYPE_P (arg) && TREE_CODE (arg) != TEMPLATE_TYPE_PARM)
14662 && (parm_quals & TYPE_QUAL_RESTRICT))
14666 if (!(strict & (UNIFY_ALLOW_MORE_CV_QUAL | UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
14667 && (arg_quals & parm_quals) != parm_quals)
14670 if (!(strict & (UNIFY_ALLOW_LESS_CV_QUAL | UNIFY_ALLOW_OUTER_LESS_CV_QUAL))
14671 && (parm_quals & arg_quals) != arg_quals)
14677 /* Determines the LEVEL and INDEX for the template parameter PARM. */
14679 template_parm_level_and_index (tree parm, int* level, int* index)
14681 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
14682 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
14683 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
14685 *index = TEMPLATE_TYPE_IDX (parm);
14686 *level = TEMPLATE_TYPE_LEVEL (parm);
14690 *index = TEMPLATE_PARM_IDX (parm);
14691 *level = TEMPLATE_PARM_LEVEL (parm);
14695 /* Unifies the remaining arguments in PACKED_ARGS with the pack
14696 expansion at the end of PACKED_PARMS. Returns 0 if the type
14697 deduction succeeds, 1 otherwise. STRICT is the same as in
14698 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
14699 call argument list. We'll need to adjust the arguments to make them
14700 types. SUBR tells us if this is from a recursive call to
14701 type_unification_real. */
14703 unify_pack_expansion (tree tparms, tree targs, tree packed_parms,
14704 tree packed_args, int strict, bool call_args_p,
14708 = TREE_VEC_ELT (packed_parms, TREE_VEC_LENGTH (packed_parms) - 1);
14709 tree pattern = PACK_EXPANSION_PATTERN (parm);
14710 tree pack, packs = NULL_TREE;
14711 int i, start = TREE_VEC_LENGTH (packed_parms) - 1;
14712 int len = TREE_VEC_LENGTH (packed_args);
14714 /* Determine the parameter packs we will be deducing from the
14715 pattern, and record their current deductions. */
14716 for (pack = PACK_EXPANSION_PARAMETER_PACKS (parm);
14717 pack; pack = TREE_CHAIN (pack))
14719 tree parm_pack = TREE_VALUE (pack);
14722 /* Determine the index and level of this parameter pack. */
14723 template_parm_level_and_index (parm_pack, &level, &idx);
14725 /* Keep track of the parameter packs and their corresponding
14727 packs = tree_cons (parm_pack, TMPL_ARG (targs, level, idx), packs);
14728 TREE_TYPE (packs) = make_tree_vec (len - start);
14731 /* Loop through all of the arguments that have not yet been
14732 unified and unify each with the pattern. */
14733 for (i = start; i < len; i++)
14735 tree parm = pattern;
14737 /* For each parameter pack, clear out the deduced value so that
14738 we can deduce it again. */
14739 for (pack = packs; pack; pack = TREE_CHAIN (pack))
14742 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
14744 TMPL_ARG (targs, level, idx) = NULL_TREE;
14747 /* Unify the pattern with the current argument. */
14749 tree arg = TREE_VEC_ELT (packed_args, i);
14750 tree arg_expr = NULL_TREE;
14751 int arg_strict = strict;
14752 bool skip_arg_p = false;
14758 /* This mirrors what we do in type_unification_real. */
14762 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL
14763 | UNIFY_ALLOW_MORE_CV_QUAL
14764 | UNIFY_ALLOW_DERIVED);
14768 sub_strict = UNIFY_ALLOW_LESS_CV_QUAL;
14772 sub_strict = UNIFY_ALLOW_NONE;
14776 gcc_unreachable ();
14781 gcc_assert (TREE_TYPE (arg) != NULL_TREE);
14782 if (type_unknown_p (arg))
14784 /* [temp.deduct.type] A template-argument can be
14785 deduced from a pointer to function or pointer
14786 to member function argument if the set of
14787 overloaded functions does not contain function
14788 templates and at most one of a set of
14789 overloaded functions provides a unique
14792 if (resolve_overloaded_unification
14793 (tparms, targs, parm, arg,
14794 (unification_kind_t) strict,
14804 arg = unlowered_expr_type (arg);
14805 if (arg == error_mark_node)
14810 arg_strict = sub_strict;
14814 maybe_adjust_types_for_deduction ((unification_kind_t) strict,
14815 &parm, &arg, arg_expr);
14820 /* For deduction from an init-list we need the actual list. */
14821 if (arg_expr && BRACE_ENCLOSED_INITIALIZER_P (arg_expr))
14823 if (unify (tparms, targs, parm, arg, arg_strict))
14828 /* For each parameter pack, collect the deduced value. */
14829 for (pack = packs; pack; pack = TREE_CHAIN (pack))
14832 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
14834 TREE_VEC_ELT (TREE_TYPE (pack), i - start) =
14835 TMPL_ARG (targs, level, idx);
14839 /* Verify that the results of unification with the parameter packs
14840 produce results consistent with what we've seen before, and make
14841 the deduced argument packs available. */
14842 for (pack = packs; pack; pack = TREE_CHAIN (pack))
14844 tree old_pack = TREE_VALUE (pack);
14845 tree new_args = TREE_TYPE (pack);
14846 int i, len = TREE_VEC_LENGTH (new_args);
14848 bool nondeduced_p = false;
14850 /* By default keep the original deduced argument pack.
14851 If necessary, more specific code is going to update the
14852 resulting deduced argument later down in this function. */
14853 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
14854 TMPL_ARG (targs, level, idx) = old_pack;
14856 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
14857 actually deduce anything. */
14858 for (i = 0; i < len && !nondeduced_p; ++i)
14859 if (TREE_VEC_ELT (new_args, i) == NULL_TREE)
14860 nondeduced_p = true;
14864 if (old_pack && ARGUMENT_PACK_INCOMPLETE_P (old_pack))
14866 /* Prepend the explicit arguments onto NEW_ARGS. */
14867 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
14868 tree old_args = new_args;
14869 int i, explicit_len = TREE_VEC_LENGTH (explicit_args);
14870 int len = explicit_len + TREE_VEC_LENGTH (old_args);
14872 /* Copy the explicit arguments. */
14873 new_args = make_tree_vec (len);
14874 for (i = 0; i < explicit_len; i++)
14875 TREE_VEC_ELT (new_args, i) = TREE_VEC_ELT (explicit_args, i);
14877 /* Copy the deduced arguments. */
14878 for (; i < len; i++)
14879 TREE_VEC_ELT (new_args, i) =
14880 TREE_VEC_ELT (old_args, i - explicit_len);
14886 /* Build the deduced *_ARGUMENT_PACK. */
14887 if (TREE_CODE (TREE_PURPOSE (pack)) == TEMPLATE_PARM_INDEX)
14889 result = make_node (NONTYPE_ARGUMENT_PACK);
14890 TREE_TYPE (result) =
14891 TREE_TYPE (TEMPLATE_PARM_DECL (TREE_PURPOSE (pack)));
14892 TREE_CONSTANT (result) = 1;
14895 result = cxx_make_type (TYPE_ARGUMENT_PACK);
14897 SET_ARGUMENT_PACK_ARGS (result, new_args);
14899 /* Note the deduced argument packs for this parameter
14901 TMPL_ARG (targs, level, idx) = result;
14903 else if (ARGUMENT_PACK_INCOMPLETE_P (old_pack)
14904 && (ARGUMENT_PACK_ARGS (old_pack)
14905 == ARGUMENT_PACK_EXPLICIT_ARGS (old_pack)))
14907 /* We only had the explicitly-provided arguments before, but
14908 now we have a complete set of arguments. */
14909 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
14911 SET_ARGUMENT_PACK_ARGS (old_pack, new_args);
14912 ARGUMENT_PACK_INCOMPLETE_P (old_pack) = 1;
14913 ARGUMENT_PACK_EXPLICIT_ARGS (old_pack) = explicit_args;
14915 else if (!comp_template_args (ARGUMENT_PACK_ARGS (old_pack),
14917 /* Inconsistent unification of this parameter pack. */
14924 /* Deduce the value of template parameters. TPARMS is the (innermost)
14925 set of template parameters to a template. TARGS is the bindings
14926 for those template parameters, as determined thus far; TARGS may
14927 include template arguments for outer levels of template parameters
14928 as well. PARM is a parameter to a template function, or a
14929 subcomponent of that parameter; ARG is the corresponding argument.
14930 This function attempts to match PARM with ARG in a manner
14931 consistent with the existing assignments in TARGS. If more values
14932 are deduced, then TARGS is updated.
14934 Returns 0 if the type deduction succeeds, 1 otherwise. The
14935 parameter STRICT is a bitwise or of the following flags:
14938 Require an exact match between PARM and ARG.
14939 UNIFY_ALLOW_MORE_CV_QUAL:
14940 Allow the deduced ARG to be more cv-qualified (by qualification
14941 conversion) than ARG.
14942 UNIFY_ALLOW_LESS_CV_QUAL:
14943 Allow the deduced ARG to be less cv-qualified than ARG.
14944 UNIFY_ALLOW_DERIVED:
14945 Allow the deduced ARG to be a template base class of ARG,
14946 or a pointer to a template base class of the type pointed to by
14948 UNIFY_ALLOW_INTEGER:
14949 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
14950 case for more information.
14951 UNIFY_ALLOW_OUTER_LEVEL:
14952 This is the outermost level of a deduction. Used to determine validity
14953 of qualification conversions. A valid qualification conversion must
14954 have const qualified pointers leading up to the inner type which
14955 requires additional CV quals, except at the outer level, where const
14956 is not required [conv.qual]. It would be normal to set this flag in
14957 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
14958 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
14959 This is the outermost level of a deduction, and PARM can be more CV
14960 qualified at this point.
14961 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
14962 This is the outermost level of a deduction, and PARM can be less CV
14963 qualified at this point. */
14966 unify (tree tparms, tree targs, tree parm, tree arg, int strict)
14971 int strict_in = strict;
14973 /* I don't think this will do the right thing with respect to types.
14974 But the only case I've seen it in so far has been array bounds, where
14975 signedness is the only information lost, and I think that will be
14977 while (TREE_CODE (parm) == NOP_EXPR)
14978 parm = TREE_OPERAND (parm, 0);
14980 if (arg == error_mark_node)
14982 if (arg == unknown_type_node
14983 || arg == init_list_type_node)
14984 /* We can't deduce anything from this, but we might get all the
14985 template args from other function args. */
14988 /* If PARM uses template parameters, then we can't bail out here,
14989 even if ARG == PARM, since we won't record unifications for the
14990 template parameters. We might need them if we're trying to
14991 figure out which of two things is more specialized. */
14992 if (arg == parm && !uses_template_parms (parm))
14995 /* Handle init lists early, so the rest of the function can assume
14996 we're dealing with a type. */
14997 if (BRACE_ENCLOSED_INITIALIZER_P (arg))
15001 tree orig_parm = parm;
15003 /* Replace T with std::initializer_list<T> for deduction. */
15004 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
15005 && flag_deduce_init_list)
15006 parm = listify (parm);
15008 if (!is_std_init_list (parm))
15009 /* We can only deduce from an initializer list argument if the
15010 parameter is std::initializer_list; otherwise this is a
15011 non-deduced context. */
15014 elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (parm), 0);
15016 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg), i, elt)
15018 int elt_strict = strict;
15020 if (elt == error_mark_node)
15023 if (!BRACE_ENCLOSED_INITIALIZER_P (elt))
15025 tree type = TREE_TYPE (elt);
15026 /* It should only be possible to get here for a call. */
15027 gcc_assert (elt_strict & UNIFY_ALLOW_OUTER_LEVEL);
15028 elt_strict |= maybe_adjust_types_for_deduction
15029 (DEDUCE_CALL, &elttype, &type, elt);
15033 if (unify (tparms, targs, elttype, elt, elt_strict))
15037 /* If the std::initializer_list<T> deduction worked, replace the
15038 deduced A with std::initializer_list<A>. */
15039 if (orig_parm != parm)
15041 idx = TEMPLATE_TYPE_IDX (orig_parm);
15042 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
15043 targ = listify (targ);
15044 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = targ;
15049 /* Immediately reject some pairs that won't unify because of
15050 cv-qualification mismatches. */
15051 if (TREE_CODE (arg) == TREE_CODE (parm)
15053 /* It is the elements of the array which hold the cv quals of an array
15054 type, and the elements might be template type parms. We'll check
15055 when we recurse. */
15056 && TREE_CODE (arg) != ARRAY_TYPE
15057 /* We check the cv-qualifiers when unifying with template type
15058 parameters below. We want to allow ARG `const T' to unify with
15059 PARM `T' for example, when computing which of two templates
15060 is more specialized, for example. */
15061 && TREE_CODE (arg) != TEMPLATE_TYPE_PARM
15062 && !check_cv_quals_for_unify (strict_in, arg, parm))
15065 if (!(strict & UNIFY_ALLOW_OUTER_LEVEL)
15066 && TYPE_P (parm) && !CP_TYPE_CONST_P (parm))
15067 strict &= ~UNIFY_ALLOW_MORE_CV_QUAL;
15068 strict &= ~UNIFY_ALLOW_OUTER_LEVEL;
15069 strict &= ~UNIFY_ALLOW_DERIVED;
15070 strict &= ~UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
15071 strict &= ~UNIFY_ALLOW_OUTER_LESS_CV_QUAL;
15073 switch (TREE_CODE (parm))
15075 case TYPENAME_TYPE:
15077 case UNBOUND_CLASS_TEMPLATE:
15078 /* In a type which contains a nested-name-specifier, template
15079 argument values cannot be deduced for template parameters used
15080 within the nested-name-specifier. */
15083 case TEMPLATE_TYPE_PARM:
15084 case TEMPLATE_TEMPLATE_PARM:
15085 case BOUND_TEMPLATE_TEMPLATE_PARM:
15086 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
15087 if (tparm == error_mark_node)
15090 if (TEMPLATE_TYPE_LEVEL (parm)
15091 != template_decl_level (tparm))
15092 /* The PARM is not one we're trying to unify. Just check
15093 to see if it matches ARG. */
15094 return (TREE_CODE (arg) == TREE_CODE (parm)
15095 && same_type_p (parm, arg)) ? 0 : 1;
15096 idx = TEMPLATE_TYPE_IDX (parm);
15097 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
15098 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, idx));
15100 /* Check for mixed types and values. */
15101 if ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
15102 && TREE_CODE (tparm) != TYPE_DECL)
15103 || (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
15104 && TREE_CODE (tparm) != TEMPLATE_DECL))
15107 if (TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
15109 /* ARG must be constructed from a template class or a template
15110 template parameter. */
15111 if (TREE_CODE (arg) != BOUND_TEMPLATE_TEMPLATE_PARM
15112 && !CLASSTYPE_SPECIALIZATION_OF_PRIMARY_TEMPLATE_P (arg))
15116 tree parmvec = TYPE_TI_ARGS (parm);
15117 tree argvec = INNERMOST_TEMPLATE_ARGS (TYPE_TI_ARGS (arg));
15118 tree full_argvec = add_to_template_args (targs, argvec);
15120 = DECL_INNERMOST_TEMPLATE_PARMS
15121 (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (parm));
15123 int parm_variadic_p = 0;
15125 /* The resolution to DR150 makes clear that default
15126 arguments for an N-argument may not be used to bind T
15127 to a template template parameter with fewer than N
15128 parameters. It is not safe to permit the binding of
15129 default arguments as an extension, as that may change
15130 the meaning of a conforming program. Consider:
15132 struct Dense { static const unsigned int dim = 1; };
15134 template <template <typename> class View,
15136 void operator+(float, View<Block> const&);
15138 template <typename Block,
15139 unsigned int Dim = Block::dim>
15140 struct Lvalue_proxy { operator float() const; };
15144 Lvalue_proxy<Dense> p;
15149 Here, if Lvalue_proxy is permitted to bind to View, then
15150 the global operator+ will be used; if they are not, the
15151 Lvalue_proxy will be converted to float. */
15152 if (coerce_template_parms (parm_parms,
15154 TYPE_TI_TEMPLATE (parm),
15156 /*require_all_args=*/true,
15157 /*use_default_args=*/false)
15158 == error_mark_node)
15161 /* Deduce arguments T, i from TT<T> or TT<i>.
15162 We check each element of PARMVEC and ARGVEC individually
15163 rather than the whole TREE_VEC since they can have
15164 different number of elements. */
15166 parmvec = expand_template_argument_pack (parmvec);
15167 argvec = expand_template_argument_pack (argvec);
15169 len = TREE_VEC_LENGTH (parmvec);
15171 /* Check if the parameters end in a pack, making them
15174 && PACK_EXPANSION_P (TREE_VEC_ELT (parmvec, len - 1)))
15175 parm_variadic_p = 1;
15177 if (TREE_VEC_LENGTH (argvec) < len - parm_variadic_p)
15180 for (i = 0; i < len - parm_variadic_p; ++i)
15182 if (unify (tparms, targs,
15183 TREE_VEC_ELT (parmvec, i),
15184 TREE_VEC_ELT (argvec, i),
15189 if (parm_variadic_p
15190 && unify_pack_expansion (tparms, targs,
15193 /*call_args_p=*/false,
15197 arg = TYPE_TI_TEMPLATE (arg);
15199 /* Fall through to deduce template name. */
15202 if (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
15203 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
15205 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
15207 /* Simple cases: Value already set, does match or doesn't. */
15208 if (targ != NULL_TREE && template_args_equal (targ, arg))
15215 /* If PARM is `const T' and ARG is only `int', we don't have
15216 a match unless we are allowing additional qualification.
15217 If ARG is `const int' and PARM is just `T' that's OK;
15218 that binds `const int' to `T'. */
15219 if (!check_cv_quals_for_unify (strict_in | UNIFY_ALLOW_LESS_CV_QUAL,
15223 /* Consider the case where ARG is `const volatile int' and
15224 PARM is `const T'. Then, T should be `volatile int'. */
15225 arg = cp_build_qualified_type_real
15226 (arg, cp_type_quals (arg) & ~cp_type_quals (parm), tf_none);
15227 if (arg == error_mark_node)
15230 /* Simple cases: Value already set, does match or doesn't. */
15231 if (targ != NULL_TREE && same_type_p (targ, arg))
15236 /* Make sure that ARG is not a variable-sized array. (Note
15237 that were talking about variable-sized arrays (like
15238 `int[n]'), rather than arrays of unknown size (like
15239 `int[]').) We'll get very confused by such a type since
15240 the bound of the array will not be computable in an
15241 instantiation. Besides, such types are not allowed in
15242 ISO C++, so we can do as we please here. */
15243 if (variably_modified_type_p (arg, NULL_TREE))
15246 /* Strip typedefs as in convert_template_argument. */
15247 arg = strip_typedefs (arg);
15250 /* If ARG is a parameter pack or an expansion, we cannot unify
15251 against it unless PARM is also a parameter pack. */
15252 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
15253 && !template_parameter_pack_p (parm))
15256 /* If the argument deduction results is a METHOD_TYPE,
15257 then there is a problem.
15258 METHOD_TYPE doesn't map to any real C++ type the result of
15259 the deduction can not be of that type. */
15260 if (TREE_CODE (arg) == METHOD_TYPE)
15263 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
15266 case TEMPLATE_PARM_INDEX:
15267 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
15268 if (tparm == error_mark_node)
15271 if (TEMPLATE_PARM_LEVEL (parm)
15272 != template_decl_level (tparm))
15273 /* The PARM is not one we're trying to unify. Just check
15274 to see if it matches ARG. */
15275 return !(TREE_CODE (arg) == TREE_CODE (parm)
15276 && cp_tree_equal (parm, arg));
15278 idx = TEMPLATE_PARM_IDX (parm);
15279 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
15282 return !cp_tree_equal (targ, arg);
15284 /* [temp.deduct.type] If, in the declaration of a function template
15285 with a non-type template-parameter, the non-type
15286 template-parameter is used in an expression in the function
15287 parameter-list and, if the corresponding template-argument is
15288 deduced, the template-argument type shall match the type of the
15289 template-parameter exactly, except that a template-argument
15290 deduced from an array bound may be of any integral type.
15291 The non-type parameter might use already deduced type parameters. */
15292 tparm = tsubst (TREE_TYPE (parm), targs, 0, NULL_TREE);
15293 if (!TREE_TYPE (arg))
15294 /* Template-parameter dependent expression. Just accept it for now.
15295 It will later be processed in convert_template_argument. */
15297 else if (same_type_p (TREE_TYPE (arg), tparm))
15299 else if ((strict & UNIFY_ALLOW_INTEGER)
15300 && (TREE_CODE (tparm) == INTEGER_TYPE
15301 || TREE_CODE (tparm) == BOOLEAN_TYPE))
15302 /* Convert the ARG to the type of PARM; the deduced non-type
15303 template argument must exactly match the types of the
15304 corresponding parameter. */
15305 arg = fold (build_nop (tparm, arg));
15306 else if (uses_template_parms (tparm))
15307 /* We haven't deduced the type of this parameter yet. Try again
15313 /* If ARG is a parameter pack or an expansion, we cannot unify
15314 against it unless PARM is also a parameter pack. */
15315 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
15316 && !TEMPLATE_PARM_PARAMETER_PACK (parm))
15319 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
15324 /* A pointer-to-member constant can be unified only with
15325 another constant. */
15326 if (TREE_CODE (arg) != PTRMEM_CST)
15329 /* Just unify the class member. It would be useless (and possibly
15330 wrong, depending on the strict flags) to unify also
15331 PTRMEM_CST_CLASS, because we want to be sure that both parm and
15332 arg refer to the same variable, even if through different
15333 classes. For instance:
15335 struct A { int x; };
15338 Unification of &A::x and &B::x must succeed. */
15339 return unify (tparms, targs, PTRMEM_CST_MEMBER (parm),
15340 PTRMEM_CST_MEMBER (arg), strict);
15345 if (TREE_CODE (arg) != POINTER_TYPE)
15348 /* [temp.deduct.call]
15350 A can be another pointer or pointer to member type that can
15351 be converted to the deduced A via a qualification
15352 conversion (_conv.qual_).
15354 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
15355 This will allow for additional cv-qualification of the
15356 pointed-to types if appropriate. */
15358 if (TREE_CODE (TREE_TYPE (arg)) == RECORD_TYPE)
15359 /* The derived-to-base conversion only persists through one
15360 level of pointers. */
15361 strict |= (strict_in & UNIFY_ALLOW_DERIVED);
15363 return unify (tparms, targs, TREE_TYPE (parm),
15364 TREE_TYPE (arg), strict);
15367 case REFERENCE_TYPE:
15368 if (TREE_CODE (arg) != REFERENCE_TYPE)
15370 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
15371 strict & UNIFY_ALLOW_MORE_CV_QUAL);
15374 if (TREE_CODE (arg) != ARRAY_TYPE)
15376 if ((TYPE_DOMAIN (parm) == NULL_TREE)
15377 != (TYPE_DOMAIN (arg) == NULL_TREE))
15379 if (TYPE_DOMAIN (parm) != NULL_TREE)
15386 /* Our representation of array types uses "N - 1" as the
15387 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
15388 not an integer constant. We cannot unify arbitrarily
15389 complex expressions, so we eliminate the MINUS_EXPRs
15391 parm_max = TYPE_MAX_VALUE (TYPE_DOMAIN (parm));
15392 parm_cst = TREE_CODE (parm_max) == INTEGER_CST;
15395 gcc_assert (TREE_CODE (parm_max) == MINUS_EXPR);
15396 parm_max = TREE_OPERAND (parm_max, 0);
15398 arg_max = TYPE_MAX_VALUE (TYPE_DOMAIN (arg));
15399 arg_cst = TREE_CODE (arg_max) == INTEGER_CST;
15402 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
15403 trying to unify the type of a variable with the type
15404 of a template parameter. For example:
15406 template <unsigned int N>
15407 void f (char (&) [N]);
15414 Here, the type of the ARG will be "int [g(i)]", and
15415 may be a SAVE_EXPR, etc. */
15416 if (TREE_CODE (arg_max) != MINUS_EXPR)
15418 arg_max = TREE_OPERAND (arg_max, 0);
15421 /* If only one of the bounds used a MINUS_EXPR, compensate
15422 by adding one to the other bound. */
15423 if (parm_cst && !arg_cst)
15424 parm_max = fold_build2_loc (input_location, PLUS_EXPR,
15428 else if (arg_cst && !parm_cst)
15429 arg_max = fold_build2_loc (input_location, PLUS_EXPR,
15434 if (unify (tparms, targs, parm_max, arg_max, UNIFY_ALLOW_INTEGER))
15437 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
15438 strict & UNIFY_ALLOW_MORE_CV_QUAL);
15445 case ENUMERAL_TYPE:
15447 if (TREE_CODE (arg) != TREE_CODE (parm))
15450 /* We have already checked cv-qualification at the top of the
15452 if (!same_type_ignoring_top_level_qualifiers_p (arg, parm))
15455 /* As far as unification is concerned, this wins. Later checks
15456 will invalidate it if necessary. */
15459 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
15460 /* Type INTEGER_CST can come from ordinary constant template args. */
15462 while (TREE_CODE (arg) == NOP_EXPR)
15463 arg = TREE_OPERAND (arg, 0);
15465 if (TREE_CODE (arg) != INTEGER_CST)
15467 return !tree_int_cst_equal (parm, arg);
15472 if (TREE_CODE (arg) != TREE_VEC)
15474 if (TREE_VEC_LENGTH (parm) != TREE_VEC_LENGTH (arg))
15476 for (i = 0; i < TREE_VEC_LENGTH (parm); ++i)
15477 if (unify (tparms, targs,
15478 TREE_VEC_ELT (parm, i), TREE_VEC_ELT (arg, i),
15486 if (TREE_CODE (arg) != TREE_CODE (parm))
15489 if (TYPE_PTRMEMFUNC_P (parm))
15491 if (!TYPE_PTRMEMFUNC_P (arg))
15494 return unify (tparms, targs,
15495 TYPE_PTRMEMFUNC_FN_TYPE (parm),
15496 TYPE_PTRMEMFUNC_FN_TYPE (arg),
15500 if (CLASSTYPE_TEMPLATE_INFO (parm))
15502 tree t = NULL_TREE;
15504 if (strict_in & UNIFY_ALLOW_DERIVED)
15506 /* First, we try to unify the PARM and ARG directly. */
15507 t = try_class_unification (tparms, targs,
15512 /* Fallback to the special case allowed in
15513 [temp.deduct.call]:
15515 If P is a class, and P has the form
15516 template-id, then A can be a derived class of
15517 the deduced A. Likewise, if P is a pointer to
15518 a class of the form template-id, A can be a
15519 pointer to a derived class pointed to by the
15521 t = get_template_base (tparms, targs, parm, arg);
15527 else if (CLASSTYPE_TEMPLATE_INFO (arg)
15528 && (CLASSTYPE_TI_TEMPLATE (parm)
15529 == CLASSTYPE_TI_TEMPLATE (arg)))
15530 /* Perhaps PARM is something like S<U> and ARG is S<int>.
15531 Then, we should unify `int' and `U'. */
15534 /* There's no chance of unification succeeding. */
15537 return unify (tparms, targs, CLASSTYPE_TI_ARGS (parm),
15538 CLASSTYPE_TI_ARGS (t), UNIFY_ALLOW_NONE);
15540 else if (!same_type_ignoring_top_level_qualifiers_p (parm, arg))
15545 case FUNCTION_TYPE:
15547 unsigned int nargs;
15552 if (TREE_CODE (arg) != TREE_CODE (parm))
15555 /* CV qualifications for methods can never be deduced, they must
15556 match exactly. We need to check them explicitly here,
15557 because type_unification_real treats them as any other
15558 cv-qualified parameter. */
15559 if (TREE_CODE (parm) == METHOD_TYPE
15560 && (!check_cv_quals_for_unify
15562 TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (arg))),
15563 TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (parm))))))
15566 if (unify (tparms, targs, TREE_TYPE (parm),
15567 TREE_TYPE (arg), UNIFY_ALLOW_NONE))
15570 nargs = list_length (TYPE_ARG_TYPES (arg));
15571 args = XALLOCAVEC (tree, nargs);
15572 for (a = TYPE_ARG_TYPES (arg), i = 0;
15573 a != NULL_TREE && a != void_list_node;
15574 a = TREE_CHAIN (a), ++i)
15575 args[i] = TREE_VALUE (a);
15578 return type_unification_real (tparms, targs, TYPE_ARG_TYPES (parm),
15579 args, nargs, 1, DEDUCE_EXACT,
15584 /* Unify a pointer to member with a pointer to member function, which
15585 deduces the type of the member as a function type. */
15586 if (TYPE_PTRMEMFUNC_P (arg))
15591 /* Check top-level cv qualifiers */
15592 if (!check_cv_quals_for_unify (UNIFY_ALLOW_NONE, arg, parm))
15595 if (unify (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
15596 TYPE_PTRMEMFUNC_OBJECT_TYPE (arg), UNIFY_ALLOW_NONE))
15599 /* Determine the type of the function we are unifying against. */
15600 method_type = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (arg));
15602 build_function_type (TREE_TYPE (method_type),
15603 TREE_CHAIN (TYPE_ARG_TYPES (method_type)));
15605 /* Extract the cv-qualifiers of the member function from the
15606 implicit object parameter and place them on the function
15607 type to be restored later. */
15608 fntype = apply_memfn_quals (fntype, type_memfn_quals (method_type));
15609 return unify (tparms, targs, TREE_TYPE (parm), fntype, strict);
15612 if (TREE_CODE (arg) != OFFSET_TYPE)
15614 if (unify (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
15615 TYPE_OFFSET_BASETYPE (arg), UNIFY_ALLOW_NONE))
15617 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
15621 if (DECL_TEMPLATE_PARM_P (parm))
15622 return unify (tparms, targs, DECL_INITIAL (parm), arg, strict);
15623 if (arg != integral_constant_value (parm))
15628 case TEMPLATE_DECL:
15629 /* Matched cases are handled by the ARG == PARM test above. */
15633 /* A non-type template parameter that is a variable should be a
15634 an integral constant, in which case, it whould have been
15635 folded into its (constant) value. So we should not be getting
15636 a variable here. */
15637 gcc_unreachable ();
15639 case TYPE_ARGUMENT_PACK:
15640 case NONTYPE_ARGUMENT_PACK:
15642 tree packed_parms = ARGUMENT_PACK_ARGS (parm);
15643 tree packed_args = ARGUMENT_PACK_ARGS (arg);
15644 int i, len = TREE_VEC_LENGTH (packed_parms);
15645 int argslen = TREE_VEC_LENGTH (packed_args);
15646 int parm_variadic_p = 0;
15648 for (i = 0; i < len; ++i)
15650 if (PACK_EXPANSION_P (TREE_VEC_ELT (packed_parms, i)))
15653 /* We can unify against something with a trailing
15655 parm_variadic_p = 1;
15657 /* Since there is something following the pack
15658 expansion, we cannot unify this template argument
15665 /* If we don't have enough arguments to satisfy the parameters
15666 (not counting the pack expression at the end), or we have
15667 too many arguments for a parameter list that doesn't end in
15668 a pack expression, we can't unify. */
15669 if (argslen < (len - parm_variadic_p)
15670 || (argslen > len && !parm_variadic_p))
15673 /* Unify all of the parameters that precede the (optional)
15674 pack expression. */
15675 for (i = 0; i < len - parm_variadic_p; ++i)
15677 if (unify (tparms, targs, TREE_VEC_ELT (packed_parms, i),
15678 TREE_VEC_ELT (packed_args, i), strict))
15682 if (parm_variadic_p)
15683 return unify_pack_expansion (tparms, targs,
15684 packed_parms, packed_args,
15685 strict, /*call_args_p=*/false,
15693 case DECLTYPE_TYPE:
15694 /* Cannot deduce anything from TYPEOF_TYPE or DECLTYPE_TYPE
15699 /* Unification fails if we hit an error node. */
15703 /* An unresolved overload is a nondeduced context. */
15704 if (type_unknown_p (parm))
15706 gcc_assert (EXPR_P (parm));
15708 /* We must be looking at an expression. This can happen with
15712 void foo(S<I>, S<I + 2>);
15714 This is a "nondeduced context":
15718 The nondeduced contexts are:
15720 --A type that is a template-id in which one or more of
15721 the template-arguments is an expression that references
15722 a template-parameter.
15724 In these cases, we assume deduction succeeded, but don't
15725 actually infer any unifications. */
15727 if (!uses_template_parms (parm)
15728 && !template_args_equal (parm, arg))
15735 /* Note that DECL can be defined in this translation unit, if
15739 mark_definable (tree decl)
15742 DECL_NOT_REALLY_EXTERN (decl) = 1;
15743 FOR_EACH_CLONE (clone, decl)
15744 DECL_NOT_REALLY_EXTERN (clone) = 1;
15747 /* Called if RESULT is explicitly instantiated, or is a member of an
15748 explicitly instantiated class. */
15751 mark_decl_instantiated (tree result, int extern_p)
15753 SET_DECL_EXPLICIT_INSTANTIATION (result);
15755 /* If this entity has already been written out, it's too late to
15756 make any modifications. */
15757 if (TREE_ASM_WRITTEN (result))
15760 if (TREE_CODE (result) != FUNCTION_DECL)
15761 /* The TREE_PUBLIC flag for function declarations will have been
15762 set correctly by tsubst. */
15763 TREE_PUBLIC (result) = 1;
15765 /* This might have been set by an earlier implicit instantiation. */
15766 DECL_COMDAT (result) = 0;
15769 DECL_NOT_REALLY_EXTERN (result) = 0;
15772 mark_definable (result);
15773 /* Always make artificials weak. */
15774 if (DECL_ARTIFICIAL (result) && flag_weak)
15775 comdat_linkage (result);
15776 /* For WIN32 we also want to put explicit instantiations in
15777 linkonce sections. */
15778 else if (TREE_PUBLIC (result))
15779 maybe_make_one_only (result);
15782 /* If EXTERN_P, then this function will not be emitted -- unless
15783 followed by an explicit instantiation, at which point its linkage
15784 will be adjusted. If !EXTERN_P, then this function will be
15785 emitted here. In neither circumstance do we want
15786 import_export_decl to adjust the linkage. */
15787 DECL_INTERFACE_KNOWN (result) = 1;
15790 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
15791 important template arguments. If any are missing, we check whether
15792 they're important by using error_mark_node for substituting into any
15793 args that were used for partial ordering (the ones between ARGS and END)
15794 and seeing if it bubbles up. */
15797 check_undeduced_parms (tree targs, tree args, tree end)
15799 bool found = false;
15801 for (i = TREE_VEC_LENGTH (targs) - 1; i >= 0; --i)
15802 if (TREE_VEC_ELT (targs, i) == NULL_TREE)
15805 TREE_VEC_ELT (targs, i) = error_mark_node;
15809 for (; args != end; args = TREE_CHAIN (args))
15811 tree substed = tsubst (TREE_VALUE (args), targs, tf_none, NULL_TREE);
15812 if (substed == error_mark_node)
15819 /* Given two function templates PAT1 and PAT2, return:
15821 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
15822 -1 if PAT2 is more specialized than PAT1.
15823 0 if neither is more specialized.
15825 LEN indicates the number of parameters we should consider
15826 (defaulted parameters should not be considered).
15828 The 1998 std underspecified function template partial ordering, and
15829 DR214 addresses the issue. We take pairs of arguments, one from
15830 each of the templates, and deduce them against each other. One of
15831 the templates will be more specialized if all the *other*
15832 template's arguments deduce against its arguments and at least one
15833 of its arguments *does* *not* deduce against the other template's
15834 corresponding argument. Deduction is done as for class templates.
15835 The arguments used in deduction have reference and top level cv
15836 qualifiers removed. Iff both arguments were originally reference
15837 types *and* deduction succeeds in both directions, the template
15838 with the more cv-qualified argument wins for that pairing (if
15839 neither is more cv-qualified, they both are equal). Unlike regular
15840 deduction, after all the arguments have been deduced in this way,
15841 we do *not* verify the deduced template argument values can be
15842 substituted into non-deduced contexts.
15844 The logic can be a bit confusing here, because we look at deduce1 and
15845 targs1 to see if pat2 is at least as specialized, and vice versa; if we
15846 can find template arguments for pat1 to make arg1 look like arg2, that
15847 means that arg2 is at least as specialized as arg1. */
15850 more_specialized_fn (tree pat1, tree pat2, int len)
15852 tree decl1 = DECL_TEMPLATE_RESULT (pat1);
15853 tree decl2 = DECL_TEMPLATE_RESULT (pat2);
15854 tree targs1 = make_tree_vec (DECL_NTPARMS (pat1));
15855 tree targs2 = make_tree_vec (DECL_NTPARMS (pat2));
15856 tree tparms1 = DECL_INNERMOST_TEMPLATE_PARMS (pat1);
15857 tree tparms2 = DECL_INNERMOST_TEMPLATE_PARMS (pat2);
15858 tree args1 = TYPE_ARG_TYPES (TREE_TYPE (decl1));
15859 tree args2 = TYPE_ARG_TYPES (TREE_TYPE (decl2));
15860 tree origs1, origs2;
15861 bool lose1 = false;
15862 bool lose2 = false;
15864 /* Remove the this parameter from non-static member functions. If
15865 one is a non-static member function and the other is not a static
15866 member function, remove the first parameter from that function
15867 also. This situation occurs for operator functions where we
15868 locate both a member function (with this pointer) and non-member
15869 operator (with explicit first operand). */
15870 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl1))
15872 len--; /* LEN is the number of significant arguments for DECL1 */
15873 args1 = TREE_CHAIN (args1);
15874 if (!DECL_STATIC_FUNCTION_P (decl2))
15875 args2 = TREE_CHAIN (args2);
15877 else if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl2))
15879 args2 = TREE_CHAIN (args2);
15880 if (!DECL_STATIC_FUNCTION_P (decl1))
15883 args1 = TREE_CHAIN (args1);
15887 /* If only one is a conversion operator, they are unordered. */
15888 if (DECL_CONV_FN_P (decl1) != DECL_CONV_FN_P (decl2))
15891 /* Consider the return type for a conversion function */
15892 if (DECL_CONV_FN_P (decl1))
15894 args1 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl1)), args1);
15895 args2 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl2)), args2);
15899 processing_template_decl++;
15905 /* Stop when an ellipsis is seen. */
15906 && args1 != NULL_TREE && args2 != NULL_TREE)
15908 tree arg1 = TREE_VALUE (args1);
15909 tree arg2 = TREE_VALUE (args2);
15910 int deduce1, deduce2;
15914 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
15915 && TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
15917 /* When both arguments are pack expansions, we need only
15918 unify the patterns themselves. */
15919 arg1 = PACK_EXPANSION_PATTERN (arg1);
15920 arg2 = PACK_EXPANSION_PATTERN (arg2);
15922 /* This is the last comparison we need to do. */
15926 if (TREE_CODE (arg1) == REFERENCE_TYPE)
15928 arg1 = TREE_TYPE (arg1);
15929 quals1 = cp_type_quals (arg1);
15932 if (TREE_CODE (arg2) == REFERENCE_TYPE)
15934 arg2 = TREE_TYPE (arg2);
15935 quals2 = cp_type_quals (arg2);
15938 if ((quals1 < 0) != (quals2 < 0))
15940 /* Only of the args is a reference, see if we should apply
15941 array/function pointer decay to it. This is not part of
15942 DR214, but is, IMHO, consistent with the deduction rules
15943 for the function call itself, and with our earlier
15944 implementation of the underspecified partial ordering
15945 rules. (nathan). */
15948 switch (TREE_CODE (arg1))
15951 arg1 = TREE_TYPE (arg1);
15953 case FUNCTION_TYPE:
15954 arg1 = build_pointer_type (arg1);
15963 switch (TREE_CODE (arg2))
15966 arg2 = TREE_TYPE (arg2);
15968 case FUNCTION_TYPE:
15969 arg2 = build_pointer_type (arg2);
15978 arg1 = TYPE_MAIN_VARIANT (arg1);
15979 arg2 = TYPE_MAIN_VARIANT (arg2);
15981 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION)
15983 int i, len2 = list_length (args2);
15984 tree parmvec = make_tree_vec (1);
15985 tree argvec = make_tree_vec (len2);
15988 /* Setup the parameter vector, which contains only ARG1. */
15989 TREE_VEC_ELT (parmvec, 0) = arg1;
15991 /* Setup the argument vector, which contains the remaining
15993 for (i = 0; i < len2; i++, ta = TREE_CHAIN (ta))
15994 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
15996 deduce1 = !unify_pack_expansion (tparms1, targs1, parmvec,
15997 argvec, UNIFY_ALLOW_NONE,
15998 /*call_args_p=*/false,
16001 /* We cannot deduce in the other direction, because ARG1 is
16002 a pack expansion but ARG2 is not. */
16005 else if (TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
16007 int i, len1 = list_length (args1);
16008 tree parmvec = make_tree_vec (1);
16009 tree argvec = make_tree_vec (len1);
16012 /* Setup the parameter vector, which contains only ARG1. */
16013 TREE_VEC_ELT (parmvec, 0) = arg2;
16015 /* Setup the argument vector, which contains the remaining
16017 for (i = 0; i < len1; i++, ta = TREE_CHAIN (ta))
16018 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
16020 deduce2 = !unify_pack_expansion (tparms2, targs2, parmvec,
16021 argvec, UNIFY_ALLOW_NONE,
16022 /*call_args_p=*/false,
16025 /* We cannot deduce in the other direction, because ARG2 is
16026 a pack expansion but ARG1 is not.*/
16032 /* The normal case, where neither argument is a pack
16034 deduce1 = !unify (tparms1, targs1, arg1, arg2, UNIFY_ALLOW_NONE);
16035 deduce2 = !unify (tparms2, targs2, arg2, arg1, UNIFY_ALLOW_NONE);
16038 /* If we couldn't deduce arguments for tparms1 to make arg1 match
16039 arg2, then arg2 is not as specialized as arg1. */
16045 /* "If, for a given type, deduction succeeds in both directions
16046 (i.e., the types are identical after the transformations above)
16047 and if the type from the argument template is more cv-qualified
16048 than the type from the parameter template (as described above)
16049 that type is considered to be more specialized than the other. If
16050 neither type is more cv-qualified than the other then neither type
16051 is more specialized than the other." */
16053 if (deduce1 && deduce2
16054 && quals1 != quals2 && quals1 >= 0 && quals2 >= 0)
16056 if ((quals1 & quals2) == quals2)
16058 if ((quals1 & quals2) == quals1)
16062 if (lose1 && lose2)
16063 /* We've failed to deduce something in either direction.
16064 These must be unordered. */
16067 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
16068 || TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
16069 /* We have already processed all of the arguments in our
16070 handing of the pack expansion type. */
16073 args1 = TREE_CHAIN (args1);
16074 args2 = TREE_CHAIN (args2);
16077 /* "In most cases, all template parameters must have values in order for
16078 deduction to succeed, but for partial ordering purposes a template
16079 parameter may remain without a value provided it is not used in the
16080 types being used for partial ordering."
16082 Thus, if we are missing any of the targs1 we need to substitute into
16083 origs1, then pat2 is not as specialized as pat1. This can happen when
16084 there is a nondeduced context. */
16085 if (!lose2 && check_undeduced_parms (targs1, origs1, args1))
16087 if (!lose1 && check_undeduced_parms (targs2, origs2, args2))
16090 processing_template_decl--;
16092 /* All things being equal, if the next argument is a pack expansion
16093 for one function but not for the other, prefer the
16094 non-variadic function. FIXME this is bogus; see c++/41958. */
16096 && args1 && TREE_VALUE (args1)
16097 && args2 && TREE_VALUE (args2))
16099 lose1 = TREE_CODE (TREE_VALUE (args1)) == TYPE_PACK_EXPANSION;
16100 lose2 = TREE_CODE (TREE_VALUE (args2)) == TYPE_PACK_EXPANSION;
16103 if (lose1 == lose2)
16111 /* Determine which of two partial specializations is more specialized.
16113 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
16114 to the first partial specialization. The TREE_VALUE is the
16115 innermost set of template parameters for the partial
16116 specialization. PAT2 is similar, but for the second template.
16118 Return 1 if the first partial specialization is more specialized;
16119 -1 if the second is more specialized; 0 if neither is more
16122 See [temp.class.order] for information about determining which of
16123 two templates is more specialized. */
16126 more_specialized_class (tree pat1, tree pat2)
16131 bool any_deductions = false;
16133 tmpl1 = TREE_TYPE (pat1);
16134 tmpl2 = TREE_TYPE (pat2);
16136 /* Just like what happens for functions, if we are ordering between
16137 different class template specializations, we may encounter dependent
16138 types in the arguments, and we need our dependency check functions
16139 to behave correctly. */
16140 ++processing_template_decl;
16141 targs = get_class_bindings (TREE_VALUE (pat1),
16142 CLASSTYPE_TI_ARGS (tmpl1),
16143 CLASSTYPE_TI_ARGS (tmpl2));
16147 any_deductions = true;
16150 targs = get_class_bindings (TREE_VALUE (pat2),
16151 CLASSTYPE_TI_ARGS (tmpl2),
16152 CLASSTYPE_TI_ARGS (tmpl1));
16156 any_deductions = true;
16158 --processing_template_decl;
16160 /* In the case of a tie where at least one of the class templates
16161 has a parameter pack at the end, the template with the most
16162 non-packed parameters wins. */
16165 && (template_args_variadic_p (TREE_PURPOSE (pat1))
16166 || template_args_variadic_p (TREE_PURPOSE (pat2))))
16168 tree args1 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat1));
16169 tree args2 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat2));
16170 int len1 = TREE_VEC_LENGTH (args1);
16171 int len2 = TREE_VEC_LENGTH (args2);
16173 /* We don't count the pack expansion at the end. */
16174 if (template_args_variadic_p (TREE_PURPOSE (pat1)))
16176 if (template_args_variadic_p (TREE_PURPOSE (pat2)))
16181 else if (len1 < len2)
16188 /* Return the template arguments that will produce the function signature
16189 DECL from the function template FN, with the explicit template
16190 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
16191 also match. Return NULL_TREE if no satisfactory arguments could be
16195 get_bindings (tree fn, tree decl, tree explicit_args, bool check_rettype)
16197 int ntparms = DECL_NTPARMS (fn);
16198 tree targs = make_tree_vec (ntparms);
16200 tree decl_arg_types;
16202 unsigned int nargs, ix;
16205 /* Substitute the explicit template arguments into the type of DECL.
16206 The call to fn_type_unification will handle substitution into the
16208 decl_type = TREE_TYPE (decl);
16209 if (explicit_args && uses_template_parms (decl_type))
16212 tree converted_args;
16214 if (DECL_TEMPLATE_INFO (decl))
16215 tmpl = DECL_TI_TEMPLATE (decl);
16217 /* We can get here for some invalid specializations. */
16221 = coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
16222 explicit_args, NULL_TREE,
16224 /*require_all_args=*/false,
16225 /*use_default_args=*/false);
16226 if (converted_args == error_mark_node)
16229 decl_type = tsubst (decl_type, converted_args, tf_none, NULL_TREE);
16230 if (decl_type == error_mark_node)
16234 /* Never do unification on the 'this' parameter. */
16235 decl_arg_types = skip_artificial_parms_for (decl,
16236 TYPE_ARG_TYPES (decl_type));
16238 nargs = list_length (decl_arg_types);
16239 args = XALLOCAVEC (tree, nargs);
16240 for (arg = decl_arg_types, ix = 0;
16241 arg != NULL_TREE && arg != void_list_node;
16242 arg = TREE_CHAIN (arg), ++ix)
16243 args[ix] = TREE_VALUE (arg);
16245 if (fn_type_unification (fn, explicit_args, targs,
16247 (check_rettype || DECL_CONV_FN_P (fn)
16248 ? TREE_TYPE (decl_type) : NULL_TREE),
16249 DEDUCE_EXACT, LOOKUP_NORMAL))
16255 /* Return the innermost template arguments that, when applied to a
16256 template specialization whose innermost template parameters are
16257 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
16260 For example, suppose we have:
16262 template <class T, class U> struct S {};
16263 template <class T> struct S<T*, int> {};
16265 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
16266 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
16267 int}. The resulting vector will be {double}, indicating that `T'
16268 is bound to `double'. */
16271 get_class_bindings (tree tparms, tree spec_args, tree args)
16273 int i, ntparms = TREE_VEC_LENGTH (tparms);
16275 tree innermost_deduced_args;
16277 innermost_deduced_args = make_tree_vec (ntparms);
16278 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
16280 deduced_args = copy_node (args);
16281 SET_TMPL_ARGS_LEVEL (deduced_args,
16282 TMPL_ARGS_DEPTH (deduced_args),
16283 innermost_deduced_args);
16286 deduced_args = innermost_deduced_args;
16288 if (unify (tparms, deduced_args,
16289 INNERMOST_TEMPLATE_ARGS (spec_args),
16290 INNERMOST_TEMPLATE_ARGS (args),
16294 for (i = 0; i < ntparms; ++i)
16295 if (! TREE_VEC_ELT (innermost_deduced_args, i))
16298 /* Verify that nondeduced template arguments agree with the type
16299 obtained from argument deduction.
16303 struct A { typedef int X; };
16304 template <class T, class U> struct C {};
16305 template <class T> struct C<T, typename T::X> {};
16307 Then with the instantiation `C<A, int>', we can deduce that
16308 `T' is `A' but unify () does not check whether `typename T::X'
16310 spec_args = tsubst (spec_args, deduced_args, tf_none, NULL_TREE);
16311 if (spec_args == error_mark_node
16312 /* We only need to check the innermost arguments; the other
16313 arguments will always agree. */
16314 || !comp_template_args (INNERMOST_TEMPLATE_ARGS (spec_args),
16315 INNERMOST_TEMPLATE_ARGS (args)))
16318 /* Now that we have bindings for all of the template arguments,
16319 ensure that the arguments deduced for the template template
16320 parameters have compatible template parameter lists. See the use
16321 of template_template_parm_bindings_ok_p in fn_type_unification
16322 for more information. */
16323 if (!template_template_parm_bindings_ok_p (tparms, deduced_args))
16326 return deduced_args;
16329 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
16330 Return the TREE_LIST node with the most specialized template, if
16331 any. If there is no most specialized template, the error_mark_node
16334 Note that this function does not look at, or modify, the
16335 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
16336 returned is one of the elements of INSTANTIATIONS, callers may
16337 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
16338 and retrieve it from the value returned. */
16341 most_specialized_instantiation (tree templates)
16345 ++processing_template_decl;
16348 for (fn = TREE_CHAIN (templates); fn; fn = TREE_CHAIN (fn))
16352 if (get_bindings (TREE_VALUE (champ),
16353 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
16354 NULL_TREE, /*check_ret=*/false))
16357 if (get_bindings (TREE_VALUE (fn),
16358 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
16359 NULL_TREE, /*check_ret=*/false))
16366 /* Equally specialized, move to next function. If there
16367 is no next function, nothing's most specialized. */
16368 fn = TREE_CHAIN (fn);
16376 /* Now verify that champ is better than everything earlier in the
16377 instantiation list. */
16378 for (fn = templates; fn != champ; fn = TREE_CHAIN (fn))
16379 if (get_bindings (TREE_VALUE (champ),
16380 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
16381 NULL_TREE, /*check_ret=*/false)
16382 || !get_bindings (TREE_VALUE (fn),
16383 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
16384 NULL_TREE, /*check_ret=*/false))
16390 processing_template_decl--;
16393 return error_mark_node;
16398 /* If DECL is a specialization of some template, return the most
16399 general such template. Otherwise, returns NULL_TREE.
16401 For example, given:
16403 template <class T> struct S { template <class U> void f(U); };
16405 if TMPL is `template <class U> void S<int>::f(U)' this will return
16406 the full template. This function will not trace past partial
16407 specializations, however. For example, given in addition:
16409 template <class T> struct S<T*> { template <class U> void f(U); };
16411 if TMPL is `template <class U> void S<int*>::f(U)' this will return
16412 `template <class T> template <class U> S<T*>::f(U)'. */
16415 most_general_template (tree decl)
16417 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
16418 an immediate specialization. */
16419 if (TREE_CODE (decl) == FUNCTION_DECL)
16421 if (DECL_TEMPLATE_INFO (decl)) {
16422 decl = DECL_TI_TEMPLATE (decl);
16424 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
16425 template friend. */
16426 if (TREE_CODE (decl) != TEMPLATE_DECL)
16432 /* Look for more and more general templates. */
16433 while (DECL_TEMPLATE_INFO (decl))
16435 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
16436 (See cp-tree.h for details.) */
16437 if (TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
16440 if (CLASS_TYPE_P (TREE_TYPE (decl))
16441 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)))
16444 /* Stop if we run into an explicitly specialized class template. */
16445 if (!DECL_NAMESPACE_SCOPE_P (decl)
16446 && DECL_CONTEXT (decl)
16447 && CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (decl)))
16450 decl = DECL_TI_TEMPLATE (decl);
16456 /* Return the most specialized of the class template partial
16457 specializations of TMPL which can produce TYPE, a specialization of
16458 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
16459 a _TYPE node corresponding to the partial specialization, while the
16460 TREE_PURPOSE is the set of template arguments that must be
16461 substituted into the TREE_TYPE in order to generate TYPE.
16463 If the choice of partial specialization is ambiguous, a diagnostic
16464 is issued, and the error_mark_node is returned. If there are no
16465 partial specializations of TMPL matching TYPE, then NULL_TREE is
16469 most_specialized_class (tree type, tree tmpl, tsubst_flags_t complain)
16471 tree list = NULL_TREE;
16477 tree outer_args = NULL_TREE;
16479 tmpl = most_general_template (tmpl);
16480 args = CLASSTYPE_TI_ARGS (type);
16482 /* For determining which partial specialization to use, only the
16483 innermost args are interesting. */
16484 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
16486 outer_args = strip_innermost_template_args (args, 1);
16487 args = INNERMOST_TEMPLATE_ARGS (args);
16490 for (t = DECL_TEMPLATE_SPECIALIZATIONS (tmpl); t; t = TREE_CHAIN (t))
16492 tree partial_spec_args;
16494 tree parms = TREE_VALUE (t);
16496 partial_spec_args = CLASSTYPE_TI_ARGS (TREE_TYPE (t));
16498 ++processing_template_decl;
16504 /* Discard the outer levels of args, and then substitute in the
16505 template args from the enclosing class. */
16506 partial_spec_args = INNERMOST_TEMPLATE_ARGS (partial_spec_args);
16507 partial_spec_args = tsubst_template_args
16508 (partial_spec_args, outer_args, tf_none, NULL_TREE);
16510 /* PARMS already refers to just the innermost parms, but the
16511 template parms in partial_spec_args had their levels lowered
16512 by tsubst, so we need to do the same for the parm list. We
16513 can't just tsubst the TREE_VEC itself, as tsubst wants to
16514 treat a TREE_VEC as an argument vector. */
16515 parms = copy_node (parms);
16516 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
16517 TREE_VEC_ELT (parms, i) =
16518 tsubst (TREE_VEC_ELT (parms, i), outer_args, tf_none, NULL_TREE);
16522 partial_spec_args =
16523 coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
16524 add_to_template_args (outer_args,
16525 partial_spec_args),
16527 /*require_all_args=*/true,
16528 /*use_default_args=*/true);
16530 --processing_template_decl;
16532 if (partial_spec_args == error_mark_node)
16533 return error_mark_node;
16535 spec_args = get_class_bindings (parms,
16541 spec_args = add_to_template_args (outer_args, spec_args);
16542 list = tree_cons (spec_args, TREE_VALUE (t), list);
16543 TREE_TYPE (list) = TREE_TYPE (t);
16550 ambiguous_p = false;
16553 t = TREE_CHAIN (t);
16554 for (; t; t = TREE_CHAIN (t))
16556 fate = more_specialized_class (champ, t);
16563 t = TREE_CHAIN (t);
16566 ambiguous_p = true;
16575 for (t = list; t && t != champ; t = TREE_CHAIN (t))
16577 fate = more_specialized_class (champ, t);
16580 ambiguous_p = true;
16588 char *spaces = NULL;
16589 if (!(complain & tf_error))
16590 return error_mark_node;
16591 error ("ambiguous class template instantiation for %q#T", type);
16592 str = ngettext ("candidate is:", "candidates are:", list_length (list));
16593 for (t = list; t; t = TREE_CHAIN (t))
16595 error ("%s %+#T", spaces ? spaces : str, TREE_TYPE (t));
16596 spaces = spaces ? spaces : get_spaces (str);
16599 return error_mark_node;
16605 /* Explicitly instantiate DECL. */
16608 do_decl_instantiation (tree decl, tree storage)
16610 tree result = NULL_TREE;
16613 if (!decl || decl == error_mark_node)
16614 /* An error occurred, for which grokdeclarator has already issued
16615 an appropriate message. */
16617 else if (! DECL_LANG_SPECIFIC (decl))
16619 error ("explicit instantiation of non-template %q#D", decl);
16622 else if (TREE_CODE (decl) == VAR_DECL)
16624 /* There is an asymmetry here in the way VAR_DECLs and
16625 FUNCTION_DECLs are handled by grokdeclarator. In the case of
16626 the latter, the DECL we get back will be marked as a
16627 template instantiation, and the appropriate
16628 DECL_TEMPLATE_INFO will be set up. This does not happen for
16629 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
16630 should handle VAR_DECLs as it currently handles
16632 if (!DECL_CLASS_SCOPE_P (decl))
16634 error ("%qD is not a static data member of a class template", decl);
16637 result = lookup_field (DECL_CONTEXT (decl), DECL_NAME (decl), 0, false);
16638 if (!result || TREE_CODE (result) != VAR_DECL)
16640 error ("no matching template for %qD found", decl);
16643 if (!same_type_p (TREE_TYPE (result), TREE_TYPE (decl)))
16645 error ("type %qT for explicit instantiation %qD does not match "
16646 "declared type %qT", TREE_TYPE (result), decl,
16651 else if (TREE_CODE (decl) != FUNCTION_DECL)
16653 error ("explicit instantiation of %q#D", decl);
16659 /* Check for various error cases. Note that if the explicit
16660 instantiation is valid the RESULT will currently be marked as an
16661 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
16662 until we get here. */
16664 if (DECL_TEMPLATE_SPECIALIZATION (result))
16666 /* DR 259 [temp.spec].
16668 Both an explicit instantiation and a declaration of an explicit
16669 specialization shall not appear in a program unless the explicit
16670 instantiation follows a declaration of the explicit specialization.
16672 For a given set of template parameters, if an explicit
16673 instantiation of a template appears after a declaration of an
16674 explicit specialization for that template, the explicit
16675 instantiation has no effect. */
16678 else if (DECL_EXPLICIT_INSTANTIATION (result))
16682 No program shall explicitly instantiate any template more
16685 We check DECL_NOT_REALLY_EXTERN so as not to complain when
16686 the first instantiation was `extern' and the second is not,
16687 and EXTERN_P for the opposite case. */
16688 if (DECL_NOT_REALLY_EXTERN (result) && !extern_p)
16689 permerror (input_location, "duplicate explicit instantiation of %q#D", result);
16690 /* If an "extern" explicit instantiation follows an ordinary
16691 explicit instantiation, the template is instantiated. */
16695 else if (!DECL_IMPLICIT_INSTANTIATION (result))
16697 error ("no matching template for %qD found", result);
16700 else if (!DECL_TEMPLATE_INFO (result))
16702 permerror (input_location, "explicit instantiation of non-template %q#D", result);
16706 if (storage == NULL_TREE)
16708 else if (storage == ridpointers[(int) RID_EXTERN])
16710 if (!in_system_header && (cxx_dialect == cxx98))
16711 pedwarn (input_location, OPT_pedantic,
16712 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
16717 error ("storage class %qD applied to template instantiation", storage);
16719 check_explicit_instantiation_namespace (result);
16720 mark_decl_instantiated (result, extern_p);
16722 instantiate_decl (result, /*defer_ok=*/1,
16723 /*expl_inst_class_mem_p=*/false);
16727 mark_class_instantiated (tree t, int extern_p)
16729 SET_CLASSTYPE_EXPLICIT_INSTANTIATION (t);
16730 SET_CLASSTYPE_INTERFACE_KNOWN (t);
16731 CLASSTYPE_INTERFACE_ONLY (t) = extern_p;
16732 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (t)) = extern_p;
16735 CLASSTYPE_DEBUG_REQUESTED (t) = 1;
16736 rest_of_type_compilation (t, 1);
16740 /* Called from do_type_instantiation through binding_table_foreach to
16741 do recursive instantiation for the type bound in ENTRY. */
16743 bt_instantiate_type_proc (binding_entry entry, void *data)
16745 tree storage = *(tree *) data;
16747 if (MAYBE_CLASS_TYPE_P (entry->type)
16748 && !uses_template_parms (CLASSTYPE_TI_ARGS (entry->type)))
16749 do_type_instantiation (TYPE_MAIN_DECL (entry->type), storage, 0);
16752 /* Called from do_type_instantiation to instantiate a member
16753 (a member function or a static member variable) of an
16754 explicitly instantiated class template. */
16756 instantiate_class_member (tree decl, int extern_p)
16758 mark_decl_instantiated (decl, extern_p);
16760 instantiate_decl (decl, /*defer_ok=*/1,
16761 /*expl_inst_class_mem_p=*/true);
16764 /* Perform an explicit instantiation of template class T. STORAGE, if
16765 non-null, is the RID for extern, inline or static. COMPLAIN is
16766 nonzero if this is called from the parser, zero if called recursively,
16767 since the standard is unclear (as detailed below). */
16770 do_type_instantiation (tree t, tree storage, tsubst_flags_t complain)
16775 int previous_instantiation_extern_p = 0;
16777 if (TREE_CODE (t) == TYPE_DECL)
16780 if (! CLASS_TYPE_P (t) || ! CLASSTYPE_TEMPLATE_INFO (t))
16782 error ("explicit instantiation of non-template type %qT", t);
16788 if (!COMPLETE_TYPE_P (t))
16790 if (complain & tf_error)
16791 error ("explicit instantiation of %q#T before definition of template",
16796 if (storage != NULL_TREE)
16798 if (!in_system_header)
16800 if (storage == ridpointers[(int) RID_EXTERN])
16802 if (cxx_dialect == cxx98)
16803 pedwarn (input_location, OPT_pedantic,
16804 "ISO C++ 1998 forbids the use of %<extern%> on "
16805 "explicit instantiations");
16808 pedwarn (input_location, OPT_pedantic,
16809 "ISO C++ forbids the use of %qE"
16810 " on explicit instantiations", storage);
16813 if (storage == ridpointers[(int) RID_INLINE])
16815 else if (storage == ridpointers[(int) RID_EXTERN])
16817 else if (storage == ridpointers[(int) RID_STATIC])
16821 error ("storage class %qD applied to template instantiation",
16827 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (t))
16829 /* DR 259 [temp.spec].
16831 Both an explicit instantiation and a declaration of an explicit
16832 specialization shall not appear in a program unless the explicit
16833 instantiation follows a declaration of the explicit specialization.
16835 For a given set of template parameters, if an explicit
16836 instantiation of a template appears after a declaration of an
16837 explicit specialization for that template, the explicit
16838 instantiation has no effect. */
16841 else if (CLASSTYPE_EXPLICIT_INSTANTIATION (t))
16845 No program shall explicitly instantiate any template more
16848 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
16849 instantiation was `extern'. If EXTERN_P then the second is.
16850 These cases are OK. */
16851 previous_instantiation_extern_p = CLASSTYPE_INTERFACE_ONLY (t);
16853 if (!previous_instantiation_extern_p && !extern_p
16854 && (complain & tf_error))
16855 permerror (input_location, "duplicate explicit instantiation of %q#T", t);
16857 /* If we've already instantiated the template, just return now. */
16858 if (!CLASSTYPE_INTERFACE_ONLY (t))
16862 check_explicit_instantiation_namespace (TYPE_NAME (t));
16863 mark_class_instantiated (t, extern_p);
16871 /* In contrast to implicit instantiation, where only the
16872 declarations, and not the definitions, of members are
16873 instantiated, we have here:
16877 The explicit instantiation of a class template specialization
16878 implies the instantiation of all of its members not
16879 previously explicitly specialized in the translation unit
16880 containing the explicit instantiation.
16882 Of course, we can't instantiate member template classes, since
16883 we don't have any arguments for them. Note that the standard
16884 is unclear on whether the instantiation of the members are
16885 *explicit* instantiations or not. However, the most natural
16886 interpretation is that it should be an explicit instantiation. */
16889 for (tmp = TYPE_METHODS (t); tmp; tmp = DECL_CHAIN (tmp))
16890 if (TREE_CODE (tmp) == FUNCTION_DECL
16891 && DECL_TEMPLATE_INSTANTIATION (tmp))
16892 instantiate_class_member (tmp, extern_p);
16894 for (tmp = TYPE_FIELDS (t); tmp; tmp = DECL_CHAIN (tmp))
16895 if (TREE_CODE (tmp) == VAR_DECL && DECL_TEMPLATE_INSTANTIATION (tmp))
16896 instantiate_class_member (tmp, extern_p);
16898 if (CLASSTYPE_NESTED_UTDS (t))
16899 binding_table_foreach (CLASSTYPE_NESTED_UTDS (t),
16900 bt_instantiate_type_proc, &storage);
16904 /* Given a function DECL, which is a specialization of TMPL, modify
16905 DECL to be a re-instantiation of TMPL with the same template
16906 arguments. TMPL should be the template into which tsubst'ing
16907 should occur for DECL, not the most general template.
16909 One reason for doing this is a scenario like this:
16912 void f(const T&, int i);
16914 void g() { f(3, 7); }
16917 void f(const T& t, const int i) { }
16919 Note that when the template is first instantiated, with
16920 instantiate_template, the resulting DECL will have no name for the
16921 first parameter, and the wrong type for the second. So, when we go
16922 to instantiate the DECL, we regenerate it. */
16925 regenerate_decl_from_template (tree decl, tree tmpl)
16927 /* The arguments used to instantiate DECL, from the most general
16932 args = DECL_TI_ARGS (decl);
16933 code_pattern = DECL_TEMPLATE_RESULT (tmpl);
16935 /* Make sure that we can see identifiers, and compute access
16937 push_access_scope (decl);
16939 if (TREE_CODE (decl) == FUNCTION_DECL)
16947 args_depth = TMPL_ARGS_DEPTH (args);
16948 parms_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
16949 if (args_depth > parms_depth)
16950 args = get_innermost_template_args (args, parms_depth);
16952 specs = tsubst_exception_specification (TREE_TYPE (code_pattern),
16953 args, tf_error, NULL_TREE);
16955 TREE_TYPE (decl) = build_exception_variant (TREE_TYPE (decl),
16958 /* Merge parameter declarations. */
16959 decl_parm = skip_artificial_parms_for (decl,
16960 DECL_ARGUMENTS (decl));
16962 = skip_artificial_parms_for (code_pattern,
16963 DECL_ARGUMENTS (code_pattern));
16964 while (decl_parm && !FUNCTION_PARAMETER_PACK_P (pattern_parm))
16969 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
16970 DECL_NAME (decl_parm) = DECL_NAME (pattern_parm);
16971 parm_type = tsubst (TREE_TYPE (pattern_parm), args, tf_error,
16973 parm_type = type_decays_to (parm_type);
16974 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
16975 TREE_TYPE (decl_parm) = parm_type;
16976 attributes = DECL_ATTRIBUTES (pattern_parm);
16977 if (DECL_ATTRIBUTES (decl_parm) != attributes)
16979 DECL_ATTRIBUTES (decl_parm) = attributes;
16980 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
16982 decl_parm = DECL_CHAIN (decl_parm);
16983 pattern_parm = DECL_CHAIN (pattern_parm);
16985 /* Merge any parameters that match with the function parameter
16987 if (pattern_parm && FUNCTION_PARAMETER_PACK_P (pattern_parm))
16990 tree expanded_types;
16991 /* Expand the TYPE_PACK_EXPANSION that provides the types for
16992 the parameters in this function parameter pack. */
16993 expanded_types = tsubst_pack_expansion (TREE_TYPE (pattern_parm),
16994 args, tf_error, NULL_TREE);
16995 len = TREE_VEC_LENGTH (expanded_types);
16996 for (i = 0; i < len; i++)
17001 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
17002 /* Rename the parameter to include the index. */
17003 DECL_NAME (decl_parm) =
17004 make_ith_pack_parameter_name (DECL_NAME (pattern_parm), i);
17005 parm_type = TREE_VEC_ELT (expanded_types, i);
17006 parm_type = type_decays_to (parm_type);
17007 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
17008 TREE_TYPE (decl_parm) = parm_type;
17009 attributes = DECL_ATTRIBUTES (pattern_parm);
17010 if (DECL_ATTRIBUTES (decl_parm) != attributes)
17012 DECL_ATTRIBUTES (decl_parm) = attributes;
17013 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
17015 decl_parm = DECL_CHAIN (decl_parm);
17018 /* Merge additional specifiers from the CODE_PATTERN. */
17019 if (DECL_DECLARED_INLINE_P (code_pattern)
17020 && !DECL_DECLARED_INLINE_P (decl))
17021 DECL_DECLARED_INLINE_P (decl) = 1;
17023 else if (TREE_CODE (decl) == VAR_DECL)
17025 DECL_INITIAL (decl) =
17026 tsubst_expr (DECL_INITIAL (code_pattern), args,
17027 tf_error, DECL_TI_TEMPLATE (decl),
17028 /*integral_constant_expression_p=*/false);
17029 if (VAR_HAD_UNKNOWN_BOUND (decl))
17030 TREE_TYPE (decl) = tsubst (TREE_TYPE (code_pattern), args,
17031 tf_error, DECL_TI_TEMPLATE (decl));
17034 gcc_unreachable ();
17036 pop_access_scope (decl);
17039 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
17040 substituted to get DECL. */
17043 template_for_substitution (tree decl)
17045 tree tmpl = DECL_TI_TEMPLATE (decl);
17047 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
17048 for the instantiation. This is not always the most general
17049 template. Consider, for example:
17052 struct S { template <class U> void f();
17053 template <> void f<int>(); };
17055 and an instantiation of S<double>::f<int>. We want TD to be the
17056 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
17057 while (/* An instantiation cannot have a definition, so we need a
17058 more general template. */
17059 DECL_TEMPLATE_INSTANTIATION (tmpl)
17060 /* We must also deal with friend templates. Given:
17062 template <class T> struct S {
17063 template <class U> friend void f() {};
17066 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
17067 so far as the language is concerned, but that's still
17068 where we get the pattern for the instantiation from. On
17069 other hand, if the definition comes outside the class, say:
17071 template <class T> struct S {
17072 template <class U> friend void f();
17074 template <class U> friend void f() {}
17076 we don't need to look any further. That's what the check for
17077 DECL_INITIAL is for. */
17078 || (TREE_CODE (decl) == FUNCTION_DECL
17079 && DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION (tmpl)
17080 && !DECL_INITIAL (DECL_TEMPLATE_RESULT (tmpl))))
17082 /* The present template, TD, should not be a definition. If it
17083 were a definition, we should be using it! Note that we
17084 cannot restructure the loop to just keep going until we find
17085 a template with a definition, since that might go too far if
17086 a specialization was declared, but not defined. */
17087 gcc_assert (TREE_CODE (decl) != VAR_DECL
17088 || DECL_IN_AGGR_P (DECL_TEMPLATE_RESULT (tmpl)));
17090 /* Fetch the more general template. */
17091 tmpl = DECL_TI_TEMPLATE (tmpl);
17097 /* Returns true if we need to instantiate this template instance even if we
17098 know we aren't going to emit it.. */
17101 always_instantiate_p (tree decl)
17103 /* We always instantiate inline functions so that we can inline them. An
17104 explicit instantiation declaration prohibits implicit instantiation of
17105 non-inline functions. With high levels of optimization, we would
17106 normally inline non-inline functions -- but we're not allowed to do
17107 that for "extern template" functions. Therefore, we check
17108 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
17109 return ((TREE_CODE (decl) == FUNCTION_DECL
17110 && DECL_DECLARED_INLINE_P (decl))
17111 /* And we need to instantiate static data members so that
17112 their initializers are available in integral constant
17114 || (TREE_CODE (decl) == VAR_DECL
17115 && decl_maybe_constant_var_p (decl)));
17118 /* Produce the definition of D, a _DECL generated from a template. If
17119 DEFER_OK is nonzero, then we don't have to actually do the
17120 instantiation now; we just have to do it sometime. Normally it is
17121 an error if this is an explicit instantiation but D is undefined.
17122 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
17123 explicitly instantiated class template. */
17126 instantiate_decl (tree d, int defer_ok,
17127 bool expl_inst_class_mem_p)
17129 tree tmpl = DECL_TI_TEMPLATE (d);
17136 bool pattern_defined;
17138 location_t saved_loc = input_location;
17141 /* This function should only be used to instantiate templates for
17142 functions and static member variables. */
17143 gcc_assert (TREE_CODE (d) == FUNCTION_DECL
17144 || TREE_CODE (d) == VAR_DECL);
17146 /* Variables are never deferred; if instantiation is required, they
17147 are instantiated right away. That allows for better code in the
17148 case that an expression refers to the value of the variable --
17149 if the variable has a constant value the referring expression can
17150 take advantage of that fact. */
17151 if (TREE_CODE (d) == VAR_DECL
17152 || DECL_DECLARED_CONSTEXPR_P (d))
17155 /* Don't instantiate cloned functions. Instead, instantiate the
17156 functions they cloned. */
17157 if (TREE_CODE (d) == FUNCTION_DECL && DECL_CLONED_FUNCTION_P (d))
17158 d = DECL_CLONED_FUNCTION (d);
17160 if (DECL_TEMPLATE_INSTANTIATED (d)
17161 || DECL_TEMPLATE_SPECIALIZATION (d))
17162 /* D has already been instantiated or explicitly specialized, so
17163 there's nothing for us to do here.
17165 It might seem reasonable to check whether or not D is an explicit
17166 instantiation, and, if so, stop here. But when an explicit
17167 instantiation is deferred until the end of the compilation,
17168 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
17169 the instantiation. */
17172 /* Check to see whether we know that this template will be
17173 instantiated in some other file, as with "extern template"
17175 external_p = (DECL_INTERFACE_KNOWN (d) && DECL_REALLY_EXTERN (d));
17177 /* In general, we do not instantiate such templates. */
17178 if (external_p && !always_instantiate_p (d))
17181 gen_tmpl = most_general_template (tmpl);
17182 gen_args = DECL_TI_ARGS (d);
17184 if (tmpl != gen_tmpl)
17185 /* We should already have the extra args. */
17186 gcc_assert (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (gen_tmpl))
17187 == TMPL_ARGS_DEPTH (gen_args));
17188 /* And what's in the hash table should match D. */
17189 gcc_assert ((spec = retrieve_specialization (gen_tmpl, gen_args, 0)) == d
17190 || spec == NULL_TREE);
17192 /* This needs to happen before any tsubsting. */
17193 if (! push_tinst_level (d))
17196 timevar_push (TV_PARSE);
17198 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
17199 for the instantiation. */
17200 td = template_for_substitution (d);
17201 code_pattern = DECL_TEMPLATE_RESULT (td);
17203 /* We should never be trying to instantiate a member of a class
17204 template or partial specialization. */
17205 gcc_assert (d != code_pattern);
17207 if ((DECL_NAMESPACE_SCOPE_P (d) && !DECL_INITIALIZED_IN_CLASS_P (d))
17208 || DECL_TEMPLATE_SPECIALIZATION (td))
17209 /* In the case of a friend template whose definition is provided
17210 outside the class, we may have too many arguments. Drop the
17211 ones we don't need. The same is true for specializations. */
17212 args = get_innermost_template_args
17213 (gen_args, TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (td)));
17217 if (TREE_CODE (d) == FUNCTION_DECL)
17218 pattern_defined = (DECL_SAVED_TREE (code_pattern) != NULL_TREE);
17220 pattern_defined = ! DECL_IN_AGGR_P (code_pattern);
17222 /* We may be in the middle of deferred access check. Disable it now. */
17223 push_deferring_access_checks (dk_no_deferred);
17225 /* Unless an explicit instantiation directive has already determined
17226 the linkage of D, remember that a definition is available for
17228 if (pattern_defined
17229 && !DECL_INTERFACE_KNOWN (d)
17230 && !DECL_NOT_REALLY_EXTERN (d))
17231 mark_definable (d);
17233 DECL_SOURCE_LOCATION (td) = DECL_SOURCE_LOCATION (code_pattern);
17234 DECL_SOURCE_LOCATION (d) = DECL_SOURCE_LOCATION (code_pattern);
17235 input_location = DECL_SOURCE_LOCATION (d);
17237 /* If D is a member of an explicitly instantiated class template,
17238 and no definition is available, treat it like an implicit
17240 if (!pattern_defined && expl_inst_class_mem_p
17241 && DECL_EXPLICIT_INSTANTIATION (d))
17243 /* Leave linkage flags alone on instantiations with anonymous
17245 if (TREE_PUBLIC (d))
17247 DECL_NOT_REALLY_EXTERN (d) = 0;
17248 DECL_INTERFACE_KNOWN (d) = 0;
17250 SET_DECL_IMPLICIT_INSTANTIATION (d);
17253 /* Recheck the substitutions to obtain any warning messages
17254 about ignoring cv qualifiers. Don't do this for artificial decls,
17255 as it breaks the context-sensitive substitution for lambda op(). */
17256 if (!defer_ok && !DECL_ARTIFICIAL (d))
17258 tree gen = DECL_TEMPLATE_RESULT (gen_tmpl);
17259 tree type = TREE_TYPE (gen);
17261 /* Make sure that we can see identifiers, and compute access
17262 correctly. D is already the target FUNCTION_DECL with the
17264 push_access_scope (d);
17266 if (TREE_CODE (gen) == FUNCTION_DECL)
17268 tsubst (DECL_ARGUMENTS (gen), gen_args, tf_warning_or_error, d);
17269 tsubst_exception_specification (type, gen_args, tf_warning_or_error,
17271 /* Don't simply tsubst the function type, as that will give
17272 duplicate warnings about poor parameter qualifications.
17273 The function arguments are the same as the decl_arguments
17274 without the top level cv qualifiers. */
17275 type = TREE_TYPE (type);
17277 tsubst (type, gen_args, tf_warning_or_error, d);
17279 pop_access_scope (d);
17282 /* Defer all other templates, unless we have been explicitly
17283 forbidden from doing so. */
17284 if (/* If there is no definition, we cannot instantiate the
17287 /* If it's OK to postpone instantiation, do so. */
17289 /* If this is a static data member that will be defined
17290 elsewhere, we don't want to instantiate the entire data
17291 member, but we do want to instantiate the initializer so that
17292 we can substitute that elsewhere. */
17293 || (external_p && TREE_CODE (d) == VAR_DECL))
17295 /* The definition of the static data member is now required so
17296 we must substitute the initializer. */
17297 if (TREE_CODE (d) == VAR_DECL
17298 && !DECL_INITIAL (d)
17299 && DECL_INITIAL (code_pattern))
17303 bool const_init = false;
17305 ns = decl_namespace_context (d);
17306 push_nested_namespace (ns);
17307 push_nested_class (DECL_CONTEXT (d));
17308 init = tsubst_expr (DECL_INITIAL (code_pattern),
17310 tf_warning_or_error, NULL_TREE,
17311 /*integral_constant_expression_p=*/false);
17312 /* Make sure the initializer is still constant, in case of
17313 circular dependency (template/instantiate6.C). */
17315 = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (code_pattern);
17316 cp_finish_decl (d, init, /*init_const_expr_p=*/const_init,
17317 /*asmspec_tree=*/NULL_TREE,
17318 LOOKUP_ONLYCONVERTING);
17319 pop_nested_class ();
17320 pop_nested_namespace (ns);
17323 /* We restore the source position here because it's used by
17324 add_pending_template. */
17325 input_location = saved_loc;
17327 if (at_eof && !pattern_defined
17328 && DECL_EXPLICIT_INSTANTIATION (d)
17329 && DECL_NOT_REALLY_EXTERN (d))
17332 The definition of a non-exported function template, a
17333 non-exported member function template, or a non-exported
17334 member function or static data member of a class template
17335 shall be present in every translation unit in which it is
17336 explicitly instantiated. */
17337 permerror (input_location, "explicit instantiation of %qD "
17338 "but no definition available", d);
17340 /* If we're in unevaluated context, we just wanted to get the
17341 constant value; this isn't an odr use, so don't queue
17342 a full instantiation. */
17343 if (cp_unevaluated_operand != 0)
17345 /* ??? Historically, we have instantiated inline functions, even
17346 when marked as "extern template". */
17347 if (!(external_p && TREE_CODE (d) == VAR_DECL))
17348 add_pending_template (d);
17351 /* Tell the repository that D is available in this translation unit
17352 -- and see if it is supposed to be instantiated here. */
17353 if (TREE_PUBLIC (d) && !DECL_REALLY_EXTERN (d) && !repo_emit_p (d))
17355 /* In a PCH file, despite the fact that the repository hasn't
17356 requested instantiation in the PCH it is still possible that
17357 an instantiation will be required in a file that includes the
17360 add_pending_template (d);
17361 /* Instantiate inline functions so that the inliner can do its
17362 job, even though we'll not be emitting a copy of this
17364 if (!(TREE_CODE (d) == FUNCTION_DECL && possibly_inlined_p (d)))
17368 need_push = !cfun || !global_bindings_p ();
17370 push_to_top_level ();
17372 /* Mark D as instantiated so that recursive calls to
17373 instantiate_decl do not try to instantiate it again. */
17374 DECL_TEMPLATE_INSTANTIATED (d) = 1;
17376 /* Regenerate the declaration in case the template has been modified
17377 by a subsequent redeclaration. */
17378 regenerate_decl_from_template (d, td);
17380 /* We already set the file and line above. Reset them now in case
17381 they changed as a result of calling regenerate_decl_from_template. */
17382 input_location = DECL_SOURCE_LOCATION (d);
17384 if (TREE_CODE (d) == VAR_DECL)
17387 bool const_init = false;
17389 /* Clear out DECL_RTL; whatever was there before may not be right
17390 since we've reset the type of the declaration. */
17391 SET_DECL_RTL (d, NULL);
17392 DECL_IN_AGGR_P (d) = 0;
17394 /* The initializer is placed in DECL_INITIAL by
17395 regenerate_decl_from_template so we don't need to
17396 push/pop_access_scope again here. Pull it out so that
17397 cp_finish_decl can process it. */
17398 init = DECL_INITIAL (d);
17399 DECL_INITIAL (d) = NULL_TREE;
17400 DECL_INITIALIZED_P (d) = 0;
17402 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
17403 initializer. That function will defer actual emission until
17404 we have a chance to determine linkage. */
17405 DECL_EXTERNAL (d) = 0;
17407 /* Enter the scope of D so that access-checking works correctly. */
17408 push_nested_class (DECL_CONTEXT (d));
17409 const_init = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (code_pattern);
17410 cp_finish_decl (d, init, const_init, NULL_TREE, 0);
17411 pop_nested_class ();
17413 else if (TREE_CODE (d) == FUNCTION_DECL)
17415 htab_t saved_local_specializations;
17420 /* Save away the current list, in case we are instantiating one
17421 template from within the body of another. */
17422 saved_local_specializations = local_specializations;
17424 /* Set up the list of local specializations. */
17425 local_specializations = htab_create (37,
17426 hash_local_specialization,
17427 eq_local_specializations,
17430 /* Set up context. */
17431 start_preparsed_function (d, NULL_TREE, SF_PRE_PARSED);
17433 /* Create substitution entries for the parameters. */
17434 subst_decl = DECL_TEMPLATE_RESULT (template_for_substitution (d));
17435 tmpl_parm = DECL_ARGUMENTS (subst_decl);
17436 spec_parm = DECL_ARGUMENTS (d);
17437 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (d))
17439 register_local_specialization (spec_parm, tmpl_parm);
17440 spec_parm = skip_artificial_parms_for (d, spec_parm);
17441 tmpl_parm = skip_artificial_parms_for (subst_decl, tmpl_parm);
17443 while (tmpl_parm && !FUNCTION_PARAMETER_PACK_P (tmpl_parm))
17445 register_local_specialization (spec_parm, tmpl_parm);
17446 tmpl_parm = DECL_CHAIN (tmpl_parm);
17447 spec_parm = DECL_CHAIN (spec_parm);
17449 if (tmpl_parm && FUNCTION_PARAMETER_PACK_P (tmpl_parm))
17451 /* Register the (value) argument pack as a specialization of
17452 TMPL_PARM, then move on. */
17453 tree argpack = make_fnparm_pack (spec_parm);
17454 register_local_specialization (argpack, tmpl_parm);
17455 tmpl_parm = DECL_CHAIN (tmpl_parm);
17456 spec_parm = NULL_TREE;
17458 gcc_assert (!spec_parm);
17460 /* Substitute into the body of the function. */
17461 tsubst_expr (DECL_SAVED_TREE (code_pattern), args,
17462 tf_warning_or_error, tmpl,
17463 /*integral_constant_expression_p=*/false);
17465 /* Set the current input_location to the end of the function
17466 so that finish_function knows where we are. */
17467 input_location = DECL_STRUCT_FUNCTION (code_pattern)->function_end_locus;
17469 /* We don't need the local specializations any more. */
17470 htab_delete (local_specializations);
17471 local_specializations = saved_local_specializations;
17473 /* Finish the function. */
17474 d = finish_function (0);
17475 expand_or_defer_fn (d);
17478 /* We're not deferring instantiation any more. */
17479 TI_PENDING_TEMPLATE_FLAG (DECL_TEMPLATE_INFO (d)) = 0;
17482 pop_from_top_level ();
17485 input_location = saved_loc;
17486 pop_deferring_access_checks ();
17487 pop_tinst_level ();
17489 timevar_pop (TV_PARSE);
17494 /* Run through the list of templates that we wish we could
17495 instantiate, and instantiate any we can. RETRIES is the
17496 number of times we retry pending template instantiation. */
17499 instantiate_pending_templates (int retries)
17502 location_t saved_loc = input_location;
17504 /* Instantiating templates may trigger vtable generation. This in turn
17505 may require further template instantiations. We place a limit here
17506 to avoid infinite loop. */
17507 if (pending_templates && retries >= max_tinst_depth)
17509 tree decl = pending_templates->tinst->decl;
17511 error ("template instantiation depth exceeds maximum of %d"
17512 " instantiating %q+D, possibly from virtual table generation"
17513 " (use -ftemplate-depth= to increase the maximum)",
17514 max_tinst_depth, decl);
17515 if (TREE_CODE (decl) == FUNCTION_DECL)
17516 /* Pretend that we defined it. */
17517 DECL_INITIAL (decl) = error_mark_node;
17523 struct pending_template **t = &pending_templates;
17524 struct pending_template *last = NULL;
17528 tree instantiation = reopen_tinst_level ((*t)->tinst);
17529 bool complete = false;
17531 if (TYPE_P (instantiation))
17535 if (!COMPLETE_TYPE_P (instantiation))
17537 instantiate_class_template (instantiation);
17538 if (CLASSTYPE_TEMPLATE_INSTANTIATION (instantiation))
17539 for (fn = TYPE_METHODS (instantiation);
17541 fn = TREE_CHAIN (fn))
17542 if (! DECL_ARTIFICIAL (fn))
17543 instantiate_decl (fn,
17545 /*expl_inst_class_mem_p=*/false);
17546 if (COMPLETE_TYPE_P (instantiation))
17550 complete = COMPLETE_TYPE_P (instantiation);
17554 if (!DECL_TEMPLATE_SPECIALIZATION (instantiation)
17555 && !DECL_TEMPLATE_INSTANTIATED (instantiation))
17558 = instantiate_decl (instantiation,
17560 /*expl_inst_class_mem_p=*/false);
17561 if (DECL_TEMPLATE_INSTANTIATED (instantiation))
17565 complete = (DECL_TEMPLATE_SPECIALIZATION (instantiation)
17566 || DECL_TEMPLATE_INSTANTIATED (instantiation));
17570 /* If INSTANTIATION has been instantiated, then we don't
17571 need to consider it again in the future. */
17579 current_tinst_level = NULL;
17581 last_pending_template = last;
17583 while (reconsider);
17585 input_location = saved_loc;
17588 /* Substitute ARGVEC into T, which is a list of initializers for
17589 either base class or a non-static data member. The TREE_PURPOSEs
17590 are DECLs, and the TREE_VALUEs are the initializer values. Used by
17591 instantiate_decl. */
17594 tsubst_initializer_list (tree t, tree argvec)
17596 tree inits = NULL_TREE;
17598 for (; t; t = TREE_CHAIN (t))
17602 tree expanded_bases = NULL_TREE;
17603 tree expanded_arguments = NULL_TREE;
17606 if (TREE_CODE (TREE_PURPOSE (t)) == TYPE_PACK_EXPANSION)
17611 /* Expand the base class expansion type into separate base
17613 expanded_bases = tsubst_pack_expansion (TREE_PURPOSE (t), argvec,
17614 tf_warning_or_error,
17616 if (expanded_bases == error_mark_node)
17619 /* We'll be building separate TREE_LISTs of arguments for
17621 len = TREE_VEC_LENGTH (expanded_bases);
17622 expanded_arguments = make_tree_vec (len);
17623 for (i = 0; i < len; i++)
17624 TREE_VEC_ELT (expanded_arguments, i) = NULL_TREE;
17626 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
17627 expand each argument in the TREE_VALUE of t. */
17628 expr = make_node (EXPR_PACK_EXPANSION);
17629 PACK_EXPANSION_PARAMETER_PACKS (expr) =
17630 PACK_EXPANSION_PARAMETER_PACKS (TREE_PURPOSE (t));
17632 if (TREE_VALUE (t) == void_type_node)
17633 /* VOID_TYPE_NODE is used to indicate
17634 value-initialization. */
17636 for (i = 0; i < len; i++)
17637 TREE_VEC_ELT (expanded_arguments, i) = void_type_node;
17641 /* Substitute parameter packs into each argument in the
17643 in_base_initializer = 1;
17644 for (arg = TREE_VALUE (t); arg; arg = TREE_CHAIN (arg))
17646 tree expanded_exprs;
17648 /* Expand the argument. */
17649 SET_PACK_EXPANSION_PATTERN (expr, TREE_VALUE (arg));
17651 = tsubst_pack_expansion (expr, argvec,
17652 tf_warning_or_error,
17654 if (expanded_exprs == error_mark_node)
17657 /* Prepend each of the expanded expressions to the
17658 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
17659 for (i = 0; i < len; i++)
17661 TREE_VEC_ELT (expanded_arguments, i) =
17662 tree_cons (NULL_TREE,
17663 TREE_VEC_ELT (expanded_exprs, i),
17664 TREE_VEC_ELT (expanded_arguments, i));
17667 in_base_initializer = 0;
17669 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
17670 since we built them backwards. */
17671 for (i = 0; i < len; i++)
17673 TREE_VEC_ELT (expanded_arguments, i) =
17674 nreverse (TREE_VEC_ELT (expanded_arguments, i));
17679 for (i = 0; i < len; ++i)
17681 if (expanded_bases)
17683 decl = TREE_VEC_ELT (expanded_bases, i);
17684 decl = expand_member_init (decl);
17685 init = TREE_VEC_ELT (expanded_arguments, i);
17689 decl = tsubst_copy (TREE_PURPOSE (t), argvec,
17690 tf_warning_or_error, NULL_TREE);
17692 decl = expand_member_init (decl);
17693 if (decl && !DECL_P (decl))
17694 in_base_initializer = 1;
17696 init = TREE_VALUE (t);
17697 if (init != void_type_node)
17698 init = tsubst_expr (init, argvec,
17699 tf_warning_or_error, NULL_TREE,
17700 /*integral_constant_expression_p=*/false);
17701 in_base_initializer = 0;
17706 init = build_tree_list (decl, init);
17707 TREE_CHAIN (init) = inits;
17715 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
17718 set_current_access_from_decl (tree decl)
17720 if (TREE_PRIVATE (decl))
17721 current_access_specifier = access_private_node;
17722 else if (TREE_PROTECTED (decl))
17723 current_access_specifier = access_protected_node;
17725 current_access_specifier = access_public_node;
17728 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
17729 is the instantiation (which should have been created with
17730 start_enum) and ARGS are the template arguments to use. */
17733 tsubst_enum (tree tag, tree newtag, tree args)
17737 if (SCOPED_ENUM_P (newtag))
17738 begin_scope (sk_scoped_enum, newtag);
17740 for (e = TYPE_VALUES (tag); e; e = TREE_CHAIN (e))
17745 decl = TREE_VALUE (e);
17746 /* Note that in a template enum, the TREE_VALUE is the
17747 CONST_DECL, not the corresponding INTEGER_CST. */
17748 value = tsubst_expr (DECL_INITIAL (decl),
17749 args, tf_warning_or_error, NULL_TREE,
17750 /*integral_constant_expression_p=*/true);
17752 /* Give this enumeration constant the correct access. */
17753 set_current_access_from_decl (decl);
17755 /* Actually build the enumerator itself. */
17757 (DECL_NAME (decl), value, newtag, DECL_SOURCE_LOCATION (decl));
17760 if (SCOPED_ENUM_P (newtag))
17763 finish_enum_value_list (newtag);
17764 finish_enum (newtag);
17766 DECL_SOURCE_LOCATION (TYPE_NAME (newtag))
17767 = DECL_SOURCE_LOCATION (TYPE_NAME (tag));
17770 /* DECL is a FUNCTION_DECL that is a template specialization. Return
17771 its type -- but without substituting the innermost set of template
17772 arguments. So, innermost set of template parameters will appear in
17776 get_mostly_instantiated_function_type (tree decl)
17784 tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
17785 targs = DECL_TI_ARGS (decl);
17786 tparms = DECL_TEMPLATE_PARMS (tmpl);
17787 parm_depth = TMPL_PARMS_DEPTH (tparms);
17789 /* There should be as many levels of arguments as there are levels
17791 gcc_assert (parm_depth == TMPL_ARGS_DEPTH (targs));
17793 fn_type = TREE_TYPE (tmpl);
17795 if (parm_depth == 1)
17796 /* No substitution is necessary. */
17800 int i, save_access_control;
17803 /* Replace the innermost level of the TARGS with NULL_TREEs to
17804 let tsubst know not to substitute for those parameters. */
17805 partial_args = make_tree_vec (TREE_VEC_LENGTH (targs));
17806 for (i = 1; i < TMPL_ARGS_DEPTH (targs); ++i)
17807 SET_TMPL_ARGS_LEVEL (partial_args, i,
17808 TMPL_ARGS_LEVEL (targs, i));
17809 SET_TMPL_ARGS_LEVEL (partial_args,
17810 TMPL_ARGS_DEPTH (targs),
17811 make_tree_vec (DECL_NTPARMS (tmpl)));
17813 /* Disable access control as this function is used only during
17815 save_access_control = flag_access_control;
17816 flag_access_control = 0;
17818 ++processing_template_decl;
17819 /* Now, do the (partial) substitution to figure out the
17820 appropriate function type. */
17821 fn_type = tsubst (fn_type, partial_args, tf_error, NULL_TREE);
17822 --processing_template_decl;
17824 /* Substitute into the template parameters to obtain the real
17825 innermost set of parameters. This step is important if the
17826 innermost set of template parameters contains value
17827 parameters whose types depend on outer template parameters. */
17828 TREE_VEC_LENGTH (partial_args)--;
17829 tparms = tsubst_template_parms (tparms, partial_args, tf_error);
17831 flag_access_control = save_access_control;
17837 /* Return truthvalue if we're processing a template different from
17838 the last one involved in diagnostics. */
17840 problematic_instantiation_changed (void)
17842 return last_template_error_tick != tinst_level_tick;
17845 /* Remember current template involved in diagnostics. */
17847 record_last_problematic_instantiation (void)
17849 last_template_error_tick = tinst_level_tick;
17852 struct tinst_level *
17853 current_instantiation (void)
17855 return current_tinst_level;
17858 /* [temp.param] Check that template non-type parm TYPE is of an allowable
17859 type. Return zero for ok, nonzero for disallowed. Issue error and
17860 warning messages under control of COMPLAIN. */
17863 invalid_nontype_parm_type_p (tree type, tsubst_flags_t complain)
17865 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
17867 else if (POINTER_TYPE_P (type))
17869 else if (TYPE_PTR_TO_MEMBER_P (type))
17871 else if (TREE_CODE (type) == TEMPLATE_TYPE_PARM)
17873 else if (TREE_CODE (type) == TYPENAME_TYPE)
17876 if (complain & tf_error)
17877 error ("%q#T is not a valid type for a template constant parameter", type);
17881 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
17882 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
17885 dependent_type_p_r (tree type)
17891 A type is dependent if it is:
17893 -- a template parameter. Template template parameters are types
17894 for us (since TYPE_P holds true for them) so we handle
17896 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
17897 || TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM)
17899 /* -- a qualified-id with a nested-name-specifier which contains a
17900 class-name that names a dependent type or whose unqualified-id
17901 names a dependent type. */
17902 if (TREE_CODE (type) == TYPENAME_TYPE)
17904 /* -- a cv-qualified type where the cv-unqualified type is
17906 type = TYPE_MAIN_VARIANT (type);
17907 /* -- a compound type constructed from any dependent type. */
17908 if (TYPE_PTR_TO_MEMBER_P (type))
17909 return (dependent_type_p (TYPE_PTRMEM_CLASS_TYPE (type))
17910 || dependent_type_p (TYPE_PTRMEM_POINTED_TO_TYPE
17912 else if (TREE_CODE (type) == POINTER_TYPE
17913 || TREE_CODE (type) == REFERENCE_TYPE)
17914 return dependent_type_p (TREE_TYPE (type));
17915 else if (TREE_CODE (type) == FUNCTION_TYPE
17916 || TREE_CODE (type) == METHOD_TYPE)
17920 if (dependent_type_p (TREE_TYPE (type)))
17922 for (arg_type = TYPE_ARG_TYPES (type);
17924 arg_type = TREE_CHAIN (arg_type))
17925 if (dependent_type_p (TREE_VALUE (arg_type)))
17929 /* -- an array type constructed from any dependent type or whose
17930 size is specified by a constant expression that is
17933 We checked for type- and value-dependence of the bounds in
17934 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
17935 if (TREE_CODE (type) == ARRAY_TYPE)
17937 if (TYPE_DOMAIN (type)
17938 && dependent_type_p (TYPE_DOMAIN (type)))
17940 return dependent_type_p (TREE_TYPE (type));
17943 /* -- a template-id in which either the template name is a template
17945 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
17947 /* ... or any of the template arguments is a dependent type or
17948 an expression that is type-dependent or value-dependent. */
17949 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INFO (type)
17950 && (any_dependent_template_arguments_p
17951 (INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type)))))
17954 /* All TYPEOF_TYPEs and DECLTYPE_TYPEs are dependent; if the
17955 argument of the `typeof' expression is not type-dependent, then
17956 it should already been have resolved. */
17957 if (TREE_CODE (type) == TYPEOF_TYPE
17958 || TREE_CODE (type) == DECLTYPE_TYPE)
17961 /* A template argument pack is dependent if any of its packed
17963 if (TREE_CODE (type) == TYPE_ARGUMENT_PACK)
17965 tree args = ARGUMENT_PACK_ARGS (type);
17966 int i, len = TREE_VEC_LENGTH (args);
17967 for (i = 0; i < len; ++i)
17968 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
17972 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
17973 be template parameters. */
17974 if (TREE_CODE (type) == TYPE_PACK_EXPANSION)
17977 /* The standard does not specifically mention types that are local
17978 to template functions or local classes, but they should be
17979 considered dependent too. For example:
17981 template <int I> void f() {
17986 The size of `E' cannot be known until the value of `I' has been
17987 determined. Therefore, `E' must be considered dependent. */
17988 scope = TYPE_CONTEXT (type);
17989 if (scope && TYPE_P (scope))
17990 return dependent_type_p (scope);
17991 else if (scope && TREE_CODE (scope) == FUNCTION_DECL)
17992 return type_dependent_expression_p (scope);
17994 /* Other types are non-dependent. */
17998 /* Returns TRUE if TYPE is dependent, in the sense of
17999 [temp.dep.type]. Note that a NULL type is considered dependent. */
18002 dependent_type_p (tree type)
18004 /* If there are no template parameters in scope, then there can't be
18005 any dependent types. */
18006 if (!processing_template_decl)
18008 /* If we are not processing a template, then nobody should be
18009 providing us with a dependent type. */
18011 gcc_assert (TREE_CODE (type) != TEMPLATE_TYPE_PARM || is_auto (type));
18015 /* If the type is NULL, we have not computed a type for the entity
18016 in question; in that case, the type is dependent. */
18020 /* Erroneous types can be considered non-dependent. */
18021 if (type == error_mark_node)
18024 /* If we have not already computed the appropriate value for TYPE,
18026 if (!TYPE_DEPENDENT_P_VALID (type))
18028 TYPE_DEPENDENT_P (type) = dependent_type_p_r (type);
18029 TYPE_DEPENDENT_P_VALID (type) = 1;
18032 return TYPE_DEPENDENT_P (type);
18035 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
18036 lookup. In other words, a dependent type that is not the current
18040 dependent_scope_p (tree scope)
18042 return (scope && TYPE_P (scope) && dependent_type_p (scope)
18043 && !currently_open_class (scope));
18046 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
18047 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
18050 /* Note that this predicate is not appropriate for general expressions;
18051 only constant expressions (that satisfy potential_constant_expression)
18052 can be tested for value dependence.
18054 We should really also have a predicate for "instantiation-dependent".
18056 fold_non_dependent_expr: fold if constant and not type-dependent and not value-dependent.
18057 (what about instantiation-dependent constant-expressions?)
18058 is_late_template_attribute: defer if instantiation-dependent.
18059 compute_array_index_type: proceed if constant and not t- or v-dependent
18060 if instantiation-dependent, need to remember full expression
18061 uses_template_parms: FIXME - need to audit callers
18062 tsubst_decl [function_decl]: Why is this using value_dependent_expression_p?
18063 dependent_type_p [array_type]: dependent if index type is dependent
18065 static_assert - instantiation-dependent */
18068 value_dependent_expression_p (tree expression)
18070 if (!processing_template_decl)
18073 /* A name declared with a dependent type. */
18074 if (DECL_P (expression) && type_dependent_expression_p (expression))
18077 switch (TREE_CODE (expression))
18079 case IDENTIFIER_NODE:
18080 /* A name that has not been looked up -- must be dependent. */
18083 case TEMPLATE_PARM_INDEX:
18084 /* A non-type template parm. */
18088 /* A non-type template parm. */
18089 if (DECL_TEMPLATE_PARM_P (expression))
18091 return value_dependent_expression_p (DECL_INITIAL (expression));
18094 /* A constant with literal type and is initialized
18095 with an expression that is value-dependent. */
18096 if (DECL_INITIAL (expression)
18097 && decl_constant_var_p (expression)
18098 && value_dependent_expression_p (DECL_INITIAL (expression)))
18102 case DYNAMIC_CAST_EXPR:
18103 case STATIC_CAST_EXPR:
18104 case CONST_CAST_EXPR:
18105 case REINTERPRET_CAST_EXPR:
18107 /* These expressions are value-dependent if the type to which
18108 the cast occurs is dependent or the expression being casted
18109 is value-dependent. */
18111 tree type = TREE_TYPE (expression);
18113 if (dependent_type_p (type))
18116 /* A functional cast has a list of operands. */
18117 expression = TREE_OPERAND (expression, 0);
18120 /* If there are no operands, it must be an expression such
18121 as "int()". This should not happen for aggregate types
18122 because it would form non-constant expressions. */
18123 gcc_assert (cxx_dialect >= cxx0x
18124 || INTEGRAL_OR_ENUMERATION_TYPE_P (type));
18129 if (TREE_CODE (expression) == TREE_LIST)
18130 return any_value_dependent_elements_p (expression);
18132 return value_dependent_expression_p (expression);
18138 /* A `sizeof' expression is value-dependent if the operand is
18139 type-dependent or is a pack expansion. */
18140 expression = TREE_OPERAND (expression, 0);
18141 if (PACK_EXPANSION_P (expression))
18143 else if (TYPE_P (expression))
18144 return dependent_type_p (expression);
18145 return type_dependent_expression_p (expression);
18147 case AT_ENCODE_EXPR:
18148 /* An 'encode' expression is value-dependent if the operand is
18150 expression = TREE_OPERAND (expression, 0);
18151 return dependent_type_p (expression);
18153 case NOEXCEPT_EXPR:
18154 expression = TREE_OPERAND (expression, 0);
18155 return type_dependent_expression_p (expression);
18159 tree name = TREE_OPERAND (expression, 1);
18160 return value_dependent_expression_p (name);
18163 case COMPONENT_REF:
18164 return (value_dependent_expression_p (TREE_OPERAND (expression, 0))
18165 || value_dependent_expression_p (TREE_OPERAND (expression, 1)));
18167 case NONTYPE_ARGUMENT_PACK:
18168 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
18169 is value-dependent. */
18171 tree values = ARGUMENT_PACK_ARGS (expression);
18172 int i, len = TREE_VEC_LENGTH (values);
18174 for (i = 0; i < len; ++i)
18175 if (value_dependent_expression_p (TREE_VEC_ELT (values, i)))
18183 tree type2 = TRAIT_EXPR_TYPE2 (expression);
18184 return (dependent_type_p (TRAIT_EXPR_TYPE1 (expression))
18185 || (type2 ? dependent_type_p (type2) : false));
18189 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
18190 || (value_dependent_expression_p (TREE_OPERAND (expression, 2))));
18193 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
18194 || (value_dependent_expression_p (TREE_OPERAND (expression, 1))));
18198 tree op = TREE_OPERAND (expression, 0);
18199 return (value_dependent_expression_p (op)
18200 || has_value_dependent_address (op));
18205 tree fn = get_callee_fndecl (expression);
18207 if (!fn && value_dependent_expression_p (CALL_EXPR_FN (expression)))
18209 nargs = call_expr_nargs (expression);
18210 for (i = 0; i < nargs; ++i)
18212 tree op = CALL_EXPR_ARG (expression, i);
18213 /* In a call to a constexpr member function, look through the
18214 implicit ADDR_EXPR on the object argument so that it doesn't
18215 cause the call to be considered value-dependent. We also
18216 look through it in potential_constant_expression. */
18217 if (i == 0 && fn && DECL_DECLARED_CONSTEXPR_P (fn)
18218 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
18219 && TREE_CODE (op) == ADDR_EXPR)
18220 op = TREE_OPERAND (op, 0);
18221 if (value_dependent_expression_p (op))
18227 case TEMPLATE_ID_EXPR:
18228 /* If a TEMPLATE_ID_EXPR involves a dependent name, it will be
18230 return type_dependent_expression_p (expression);
18233 /* A constant expression is value-dependent if any subexpression is
18234 value-dependent. */
18235 switch (TREE_CODE_CLASS (TREE_CODE (expression)))
18237 case tcc_reference:
18239 return (value_dependent_expression_p
18240 (TREE_OPERAND (expression, 0)));
18242 case tcc_comparison:
18244 return ((value_dependent_expression_p
18245 (TREE_OPERAND (expression, 0)))
18246 || (value_dependent_expression_p
18247 (TREE_OPERAND (expression, 1))));
18249 case tcc_expression:
18253 for (i = 0; i < TREE_OPERAND_LENGTH (expression); ++i)
18254 /* In some cases, some of the operands may be missing.
18255 (For example, in the case of PREDECREMENT_EXPR, the
18256 amount to increment by may be missing.) That doesn't
18257 make the expression dependent. */
18258 if (TREE_OPERAND (expression, i)
18259 && (value_dependent_expression_p
18260 (TREE_OPERAND (expression, i))))
18270 /* The expression is not value-dependent. */
18274 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
18275 [temp.dep.expr]. Note that an expression with no type is
18276 considered dependent. Other parts of the compiler arrange for an
18277 expression with type-dependent subexpressions to have no type, so
18278 this function doesn't have to be fully recursive. */
18281 type_dependent_expression_p (tree expression)
18283 if (!processing_template_decl)
18286 if (expression == error_mark_node)
18289 /* An unresolved name is always dependent. */
18290 if (TREE_CODE (expression) == IDENTIFIER_NODE
18291 || TREE_CODE (expression) == USING_DECL)
18294 /* Some expression forms are never type-dependent. */
18295 if (TREE_CODE (expression) == PSEUDO_DTOR_EXPR
18296 || TREE_CODE (expression) == SIZEOF_EXPR
18297 || TREE_CODE (expression) == ALIGNOF_EXPR
18298 || TREE_CODE (expression) == AT_ENCODE_EXPR
18299 || TREE_CODE (expression) == NOEXCEPT_EXPR
18300 || TREE_CODE (expression) == TRAIT_EXPR
18301 || TREE_CODE (expression) == TYPEID_EXPR
18302 || TREE_CODE (expression) == DELETE_EXPR
18303 || TREE_CODE (expression) == VEC_DELETE_EXPR
18304 || TREE_CODE (expression) == THROW_EXPR)
18307 /* The types of these expressions depends only on the type to which
18308 the cast occurs. */
18309 if (TREE_CODE (expression) == DYNAMIC_CAST_EXPR
18310 || TREE_CODE (expression) == STATIC_CAST_EXPR
18311 || TREE_CODE (expression) == CONST_CAST_EXPR
18312 || TREE_CODE (expression) == REINTERPRET_CAST_EXPR
18313 || TREE_CODE (expression) == CAST_EXPR)
18314 return dependent_type_p (TREE_TYPE (expression));
18316 /* The types of these expressions depends only on the type created
18317 by the expression. */
18318 if (TREE_CODE (expression) == NEW_EXPR
18319 || TREE_CODE (expression) == VEC_NEW_EXPR)
18321 /* For NEW_EXPR tree nodes created inside a template, either
18322 the object type itself or a TREE_LIST may appear as the
18324 tree type = TREE_OPERAND (expression, 1);
18325 if (TREE_CODE (type) == TREE_LIST)
18326 /* This is an array type. We need to check array dimensions
18328 return dependent_type_p (TREE_VALUE (TREE_PURPOSE (type)))
18329 || value_dependent_expression_p
18330 (TREE_OPERAND (TREE_VALUE (type), 1));
18332 return dependent_type_p (type);
18335 if (TREE_CODE (expression) == SCOPE_REF)
18337 tree scope = TREE_OPERAND (expression, 0);
18338 tree name = TREE_OPERAND (expression, 1);
18340 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
18341 contains an identifier associated by name lookup with one or more
18342 declarations declared with a dependent type, or...a
18343 nested-name-specifier or qualified-id that names a member of an
18344 unknown specialization. */
18345 return (type_dependent_expression_p (name)
18346 || dependent_scope_p (scope));
18349 if (TREE_CODE (expression) == FUNCTION_DECL
18350 && DECL_LANG_SPECIFIC (expression)
18351 && DECL_TEMPLATE_INFO (expression)
18352 && (any_dependent_template_arguments_p
18353 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (expression)))))
18356 if (TREE_CODE (expression) == TEMPLATE_DECL
18357 && !DECL_TEMPLATE_TEMPLATE_PARM_P (expression))
18360 if (TREE_CODE (expression) == STMT_EXPR)
18361 expression = stmt_expr_value_expr (expression);
18363 if (BRACE_ENCLOSED_INITIALIZER_P (expression))
18368 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), i, elt)
18370 if (type_dependent_expression_p (elt))
18376 /* A static data member of the current instantiation with incomplete
18377 array type is type-dependent, as the definition and specializations
18378 can have different bounds. */
18379 if (TREE_CODE (expression) == VAR_DECL
18380 && DECL_CLASS_SCOPE_P (expression)
18381 && dependent_type_p (DECL_CONTEXT (expression))
18382 && VAR_HAD_UNKNOWN_BOUND (expression))
18385 if (TREE_TYPE (expression) == unknown_type_node)
18387 if (TREE_CODE (expression) == ADDR_EXPR)
18388 return type_dependent_expression_p (TREE_OPERAND (expression, 0));
18389 if (TREE_CODE (expression) == COMPONENT_REF
18390 || TREE_CODE (expression) == OFFSET_REF)
18392 if (type_dependent_expression_p (TREE_OPERAND (expression, 0)))
18394 expression = TREE_OPERAND (expression, 1);
18395 if (TREE_CODE (expression) == IDENTIFIER_NODE)
18398 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
18399 if (TREE_CODE (expression) == SCOPE_REF)
18402 if (TREE_CODE (expression) == BASELINK)
18403 expression = BASELINK_FUNCTIONS (expression);
18405 if (TREE_CODE (expression) == TEMPLATE_ID_EXPR)
18407 if (any_dependent_template_arguments_p
18408 (TREE_OPERAND (expression, 1)))
18410 expression = TREE_OPERAND (expression, 0);
18412 gcc_assert (TREE_CODE (expression) == OVERLOAD
18413 || TREE_CODE (expression) == FUNCTION_DECL);
18417 if (type_dependent_expression_p (OVL_CURRENT (expression)))
18419 expression = OVL_NEXT (expression);
18424 gcc_assert (TREE_CODE (expression) != TYPE_DECL);
18426 return (dependent_type_p (TREE_TYPE (expression)));
18429 /* Like type_dependent_expression_p, but it also works while not processing
18430 a template definition, i.e. during substitution or mangling. */
18433 type_dependent_expression_p_push (tree expr)
18436 ++processing_template_decl;
18437 b = type_dependent_expression_p (expr);
18438 --processing_template_decl;
18442 /* Returns TRUE if ARGS contains a type-dependent expression. */
18445 any_type_dependent_arguments_p (const VEC(tree,gc) *args)
18450 FOR_EACH_VEC_ELT (tree, args, i, arg)
18452 if (type_dependent_expression_p (arg))
18458 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
18459 expressions) contains any value-dependent expressions. */
18462 any_value_dependent_elements_p (const_tree list)
18464 for (; list; list = TREE_CHAIN (list))
18465 if (value_dependent_expression_p (TREE_VALUE (list)))
18471 /* Returns TRUE if the ARG (a template argument) is dependent. */
18474 dependent_template_arg_p (tree arg)
18476 if (!processing_template_decl)
18479 /* Assume a template argument that was wrongly written by the user
18480 is dependent. This is consistent with what
18481 any_dependent_template_arguments_p [that calls this function]
18483 if (arg == error_mark_node)
18486 if (TREE_CODE (arg) == TEMPLATE_DECL
18487 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
18488 return dependent_template_p (arg);
18489 else if (ARGUMENT_PACK_P (arg))
18491 tree args = ARGUMENT_PACK_ARGS (arg);
18492 int i, len = TREE_VEC_LENGTH (args);
18493 for (i = 0; i < len; ++i)
18495 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
18501 else if (TYPE_P (arg))
18502 return dependent_type_p (arg);
18504 return (type_dependent_expression_p (arg)
18505 || value_dependent_expression_p (arg));
18508 /* Returns true if ARGS (a collection of template arguments) contains
18509 any types that require structural equality testing. */
18512 any_template_arguments_need_structural_equality_p (tree args)
18519 if (args == error_mark_node)
18522 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
18524 tree level = TMPL_ARGS_LEVEL (args, i + 1);
18525 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
18527 tree arg = TREE_VEC_ELT (level, j);
18528 tree packed_args = NULL_TREE;
18531 if (ARGUMENT_PACK_P (arg))
18533 /* Look inside the argument pack. */
18534 packed_args = ARGUMENT_PACK_ARGS (arg);
18535 len = TREE_VEC_LENGTH (packed_args);
18538 for (k = 0; k < len; ++k)
18541 arg = TREE_VEC_ELT (packed_args, k);
18543 if (error_operand_p (arg))
18545 else if (TREE_CODE (arg) == TEMPLATE_DECL
18546 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
18548 else if (TYPE_P (arg) && TYPE_STRUCTURAL_EQUALITY_P (arg))
18550 else if (!TYPE_P (arg) && TREE_TYPE (arg)
18551 && TYPE_STRUCTURAL_EQUALITY_P (TREE_TYPE (arg)))
18560 /* Returns true if ARGS (a collection of template arguments) contains
18561 any dependent arguments. */
18564 any_dependent_template_arguments_p (const_tree args)
18571 if (args == error_mark_node)
18574 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
18576 const_tree level = TMPL_ARGS_LEVEL (args, i + 1);
18577 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
18578 if (dependent_template_arg_p (TREE_VEC_ELT (level, j)))
18585 /* Returns TRUE if the template TMPL is dependent. */
18588 dependent_template_p (tree tmpl)
18590 if (TREE_CODE (tmpl) == OVERLOAD)
18594 if (dependent_template_p (OVL_CURRENT (tmpl)))
18596 tmpl = OVL_NEXT (tmpl);
18601 /* Template template parameters are dependent. */
18602 if (DECL_TEMPLATE_TEMPLATE_PARM_P (tmpl)
18603 || TREE_CODE (tmpl) == TEMPLATE_TEMPLATE_PARM)
18605 /* So are names that have not been looked up. */
18606 if (TREE_CODE (tmpl) == SCOPE_REF
18607 || TREE_CODE (tmpl) == IDENTIFIER_NODE)
18609 /* So are member templates of dependent classes. */
18610 if (TYPE_P (CP_DECL_CONTEXT (tmpl)))
18611 return dependent_type_p (DECL_CONTEXT (tmpl));
18615 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
18618 dependent_template_id_p (tree tmpl, tree args)
18620 return (dependent_template_p (tmpl)
18621 || any_dependent_template_arguments_p (args));
18624 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
18628 dependent_omp_for_p (tree declv, tree initv, tree condv, tree incrv)
18632 if (!processing_template_decl)
18635 for (i = 0; i < TREE_VEC_LENGTH (declv); i++)
18637 tree decl = TREE_VEC_ELT (declv, i);
18638 tree init = TREE_VEC_ELT (initv, i);
18639 tree cond = TREE_VEC_ELT (condv, i);
18640 tree incr = TREE_VEC_ELT (incrv, i);
18642 if (type_dependent_expression_p (decl))
18645 if (init && type_dependent_expression_p (init))
18648 if (type_dependent_expression_p (cond))
18651 if (COMPARISON_CLASS_P (cond)
18652 && (type_dependent_expression_p (TREE_OPERAND (cond, 0))
18653 || type_dependent_expression_p (TREE_OPERAND (cond, 1))))
18656 if (TREE_CODE (incr) == MODOP_EXPR)
18658 if (type_dependent_expression_p (TREE_OPERAND (incr, 0))
18659 || type_dependent_expression_p (TREE_OPERAND (incr, 2)))
18662 else if (type_dependent_expression_p (incr))
18664 else if (TREE_CODE (incr) == MODIFY_EXPR)
18666 if (type_dependent_expression_p (TREE_OPERAND (incr, 0)))
18668 else if (BINARY_CLASS_P (TREE_OPERAND (incr, 1)))
18670 tree t = TREE_OPERAND (incr, 1);
18671 if (type_dependent_expression_p (TREE_OPERAND (t, 0))
18672 || type_dependent_expression_p (TREE_OPERAND (t, 1)))
18681 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
18682 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
18683 no such TYPE can be found. Note that this function peers inside
18684 uninstantiated templates and therefore should be used only in
18685 extremely limited situations. ONLY_CURRENT_P restricts this
18686 peering to the currently open classes hierarchy (which is required
18687 when comparing types). */
18690 resolve_typename_type (tree type, bool only_current_p)
18699 gcc_assert (TREE_CODE (type) == TYPENAME_TYPE);
18701 scope = TYPE_CONTEXT (type);
18702 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
18703 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
18704 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
18705 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
18706 identifier of the TYPENAME_TYPE anymore.
18707 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
18708 TYPENAME_TYPE instead, we avoid messing up with a possible
18709 typedef variant case. */
18710 name = TYPE_IDENTIFIER (TYPE_MAIN_VARIANT (type));
18712 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
18713 it first before we can figure out what NAME refers to. */
18714 if (TREE_CODE (scope) == TYPENAME_TYPE)
18715 scope = resolve_typename_type (scope, only_current_p);
18716 /* If we don't know what SCOPE refers to, then we cannot resolve the
18718 if (TREE_CODE (scope) == TYPENAME_TYPE)
18720 /* If the SCOPE is a template type parameter, we have no way of
18721 resolving the name. */
18722 if (TREE_CODE (scope) == TEMPLATE_TYPE_PARM)
18724 /* If the SCOPE is not the current instantiation, there's no reason
18725 to look inside it. */
18726 if (only_current_p && !currently_open_class (scope))
18728 /* If this is a typedef, we don't want to look inside (c++/11987). */
18729 if (typedef_variant_p (type))
18731 /* If SCOPE isn't the template itself, it will not have a valid
18732 TYPE_FIELDS list. */
18733 if (same_type_p (scope, CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope)))
18734 /* scope is either the template itself or a compatible instantiation
18735 like X<T>, so look up the name in the original template. */
18736 scope = CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope);
18738 /* scope is a partial instantiation, so we can't do the lookup or we
18739 will lose the template arguments. */
18741 /* Enter the SCOPE so that name lookup will be resolved as if we
18742 were in the class definition. In particular, SCOPE will no
18743 longer be considered a dependent type. */
18744 pushed_scope = push_scope (scope);
18745 /* Look up the declaration. */
18746 decl = lookup_member (scope, name, /*protect=*/0, /*want_type=*/true);
18748 result = NULL_TREE;
18750 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
18751 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
18754 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == IDENTIFIER_NODE
18755 && TREE_CODE (decl) == TYPE_DECL)
18757 result = TREE_TYPE (decl);
18758 if (result == error_mark_node)
18759 result = NULL_TREE;
18761 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == TEMPLATE_ID_EXPR
18762 && DECL_CLASS_TEMPLATE_P (decl))
18766 /* Obtain the template and the arguments. */
18767 tmpl = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 0);
18768 args = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 1);
18769 /* Instantiate the template. */
18770 result = lookup_template_class (tmpl, args, NULL_TREE, NULL_TREE,
18771 /*entering_scope=*/0,
18772 tf_error | tf_user);
18773 if (result == error_mark_node)
18774 result = NULL_TREE;
18777 /* Leave the SCOPE. */
18779 pop_scope (pushed_scope);
18781 /* If we failed to resolve it, return the original typename. */
18785 /* If lookup found a typename type, resolve that too. */
18786 if (TREE_CODE (result) == TYPENAME_TYPE && !TYPENAME_IS_RESOLVING_P (result))
18788 /* Ill-formed programs can cause infinite recursion here, so we
18789 must catch that. */
18790 TYPENAME_IS_RESOLVING_P (type) = 1;
18791 result = resolve_typename_type (result, only_current_p);
18792 TYPENAME_IS_RESOLVING_P (type) = 0;
18795 /* Qualify the resulting type. */
18796 quals = cp_type_quals (type);
18798 result = cp_build_qualified_type (result, cp_type_quals (result) | quals);
18803 /* EXPR is an expression which is not type-dependent. Return a proxy
18804 for EXPR that can be used to compute the types of larger
18805 expressions containing EXPR. */
18808 build_non_dependent_expr (tree expr)
18812 /* Preserve null pointer constants so that the type of things like
18813 "p == 0" where "p" is a pointer can be determined. */
18814 if (null_ptr_cst_p (expr))
18816 /* Preserve OVERLOADs; the functions must be available to resolve
18819 if (TREE_CODE (inner_expr) == STMT_EXPR)
18820 inner_expr = stmt_expr_value_expr (inner_expr);
18821 if (TREE_CODE (inner_expr) == ADDR_EXPR)
18822 inner_expr = TREE_OPERAND (inner_expr, 0);
18823 if (TREE_CODE (inner_expr) == COMPONENT_REF)
18824 inner_expr = TREE_OPERAND (inner_expr, 1);
18825 if (is_overloaded_fn (inner_expr)
18826 || TREE_CODE (inner_expr) == OFFSET_REF)
18828 /* There is no need to return a proxy for a variable. */
18829 if (TREE_CODE (expr) == VAR_DECL)
18831 /* Preserve string constants; conversions from string constants to
18832 "char *" are allowed, even though normally a "const char *"
18833 cannot be used to initialize a "char *". */
18834 if (TREE_CODE (expr) == STRING_CST)
18836 /* Preserve arithmetic constants, as an optimization -- there is no
18837 reason to create a new node. */
18838 if (TREE_CODE (expr) == INTEGER_CST || TREE_CODE (expr) == REAL_CST)
18840 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
18841 There is at least one place where we want to know that a
18842 particular expression is a throw-expression: when checking a ?:
18843 expression, there are special rules if the second or third
18844 argument is a throw-expression. */
18845 if (TREE_CODE (expr) == THROW_EXPR)
18848 if (TREE_CODE (expr) == COND_EXPR)
18849 return build3 (COND_EXPR,
18851 TREE_OPERAND (expr, 0),
18852 (TREE_OPERAND (expr, 1)
18853 ? build_non_dependent_expr (TREE_OPERAND (expr, 1))
18854 : build_non_dependent_expr (TREE_OPERAND (expr, 0))),
18855 build_non_dependent_expr (TREE_OPERAND (expr, 2)));
18856 if (TREE_CODE (expr) == COMPOUND_EXPR
18857 && !COMPOUND_EXPR_OVERLOADED (expr))
18858 return build2 (COMPOUND_EXPR,
18860 TREE_OPERAND (expr, 0),
18861 build_non_dependent_expr (TREE_OPERAND (expr, 1)));
18863 /* Keep dereferences outside the NON_DEPENDENT_EXPR so lvalue_kind
18864 doesn't need to look inside. */
18865 if (TREE_CODE (expr) == INDIRECT_REF && REFERENCE_REF_P (expr))
18866 return convert_from_reference (build_non_dependent_expr
18867 (TREE_OPERAND (expr, 0)));
18869 /* If the type is unknown, it can't really be non-dependent */
18870 gcc_assert (TREE_TYPE (expr) != unknown_type_node);
18872 /* Otherwise, build a NON_DEPENDENT_EXPR. */
18873 return build1 (NON_DEPENDENT_EXPR, TREE_TYPE (expr), expr);
18876 /* ARGS is a vector of expressions as arguments to a function call.
18877 Replace the arguments with equivalent non-dependent expressions.
18878 This modifies ARGS in place. */
18881 make_args_non_dependent (VEC(tree,gc) *args)
18886 FOR_EACH_VEC_ELT (tree, args, ix, arg)
18888 tree newarg = build_non_dependent_expr (arg);
18890 VEC_replace (tree, args, ix, newarg);
18894 /* Returns a type which represents 'auto'. We use a TEMPLATE_TYPE_PARM
18895 with a level one deeper than the actual template parms. */
18900 tree au = cxx_make_type (TEMPLATE_TYPE_PARM);
18901 TYPE_NAME (au) = build_decl (BUILTINS_LOCATION,
18902 TYPE_DECL, get_identifier ("auto"), au);
18903 TYPE_STUB_DECL (au) = TYPE_NAME (au);
18904 TEMPLATE_TYPE_PARM_INDEX (au) = build_template_parm_index
18905 (0, processing_template_decl + 1, processing_template_decl + 1,
18906 0, TYPE_NAME (au), NULL_TREE);
18907 TYPE_CANONICAL (au) = canonical_type_parameter (au);
18908 DECL_ARTIFICIAL (TYPE_NAME (au)) = 1;
18909 SET_DECL_TEMPLATE_PARM_P (TYPE_NAME (au));
18914 /* Given type ARG, return std::initializer_list<ARG>. */
18919 tree std_init_list = namespace_binding
18920 (get_identifier ("initializer_list"), std_node);
18922 if (!std_init_list || !DECL_CLASS_TEMPLATE_P (std_init_list))
18924 error ("deducing from brace-enclosed initializer list requires "
18925 "#include <initializer_list>");
18926 return error_mark_node;
18928 argvec = make_tree_vec (1);
18929 TREE_VEC_ELT (argvec, 0) = arg;
18930 return lookup_template_class (std_init_list, argvec, NULL_TREE,
18931 NULL_TREE, 0, tf_warning_or_error);
18934 /* Replace auto in TYPE with std::initializer_list<auto>. */
18937 listify_autos (tree type, tree auto_node)
18939 tree init_auto = listify (auto_node);
18940 tree argvec = make_tree_vec (1);
18941 TREE_VEC_ELT (argvec, 0) = init_auto;
18942 if (processing_template_decl)
18943 argvec = add_to_template_args (current_template_args (), argvec);
18944 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
18947 /* walk_tree helper for do_auto_deduction. */
18950 contains_auto_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
18953 /* Is this a variable with the type we're looking for? */
18955 && TREE_TYPE (*tp) == type)
18961 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
18962 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
18965 do_auto_deduction (tree type, tree init, tree auto_node)
18967 tree parms, tparms, targs;
18972 /* The name of the object being declared shall not appear in the
18973 initializer expression. */
18974 decl = cp_walk_tree_without_duplicates (&init, contains_auto_r, type);
18977 error ("variable %q#D with %<auto%> type used in its own "
18978 "initializer", decl);
18979 return error_mark_node;
18982 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
18983 with either a new invented type template parameter U or, if the
18984 initializer is a braced-init-list (8.5.4), with
18985 std::initializer_list<U>. */
18986 if (BRACE_ENCLOSED_INITIALIZER_P (init))
18987 type = listify_autos (type, auto_node);
18989 init = resolve_nondeduced_context (init);
18991 parms = build_tree_list (NULL_TREE, type);
18993 tparms = make_tree_vec (1);
18994 targs = make_tree_vec (1);
18995 TREE_VEC_ELT (tparms, 0)
18996 = build_tree_list (NULL_TREE, TYPE_NAME (auto_node));
18997 val = type_unification_real (tparms, targs, parms, args, 1, 0,
18998 DEDUCE_CALL, LOOKUP_NORMAL);
19001 if (type && type != error_mark_node)
19002 /* If type is error_mark_node a diagnostic must have been
19003 emitted by now. Also, having a mention to '<type error>'
19004 in the diagnostic is not really useful to the user. */
19005 error ("unable to deduce %qT from %qE", type, init);
19006 return error_mark_node;
19009 /* If the list of declarators contains more than one declarator, the type
19010 of each declared variable is determined as described above. If the
19011 type deduced for the template parameter U is not the same in each
19012 deduction, the program is ill-formed. */
19013 if (TREE_TYPE (auto_node)
19014 && !same_type_p (TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0)))
19016 error ("inconsistent deduction for %qT: %qT and then %qT",
19017 auto_node, TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0));
19018 return error_mark_node;
19020 TREE_TYPE (auto_node) = TREE_VEC_ELT (targs, 0);
19022 if (processing_template_decl)
19023 targs = add_to_template_args (current_template_args (), targs);
19024 return tsubst (type, targs, tf_warning_or_error, NULL_TREE);
19027 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
19031 splice_late_return_type (tree type, tree late_return_type)
19035 if (late_return_type == NULL_TREE)
19037 argvec = make_tree_vec (1);
19038 TREE_VEC_ELT (argvec, 0) = late_return_type;
19039 if (processing_template_decl)
19040 argvec = add_to_template_args (current_template_args (), argvec);
19041 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
19044 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto'. */
19047 is_auto (const_tree type)
19049 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
19050 && TYPE_IDENTIFIER (type) == get_identifier ("auto"))
19056 /* Returns true iff TYPE contains a use of 'auto'. Since auto can only
19057 appear as a type-specifier for the declaration in question, we don't
19058 have to look through the whole type. */
19061 type_uses_auto (tree type)
19063 enum tree_code code;
19064 if (is_auto (type))
19067 code = TREE_CODE (type);
19069 if (code == POINTER_TYPE || code == REFERENCE_TYPE
19070 || code == OFFSET_TYPE || code == FUNCTION_TYPE
19071 || code == METHOD_TYPE || code == ARRAY_TYPE)
19072 return type_uses_auto (TREE_TYPE (type));
19074 if (TYPE_PTRMEMFUNC_P (type))
19075 return type_uses_auto (TREE_TYPE (TREE_TYPE
19076 (TYPE_PTRMEMFUNC_FN_TYPE (type))));
19081 /* For a given template T, return the vector of typedefs referenced
19082 in T for which access check is needed at T instantiation time.
19083 T is either a FUNCTION_DECL or a RECORD_TYPE.
19084 Those typedefs were added to T by the function
19085 append_type_to_template_for_access_check. */
19087 VEC(qualified_typedef_usage_t,gc)*
19088 get_types_needing_access_check (tree t)
19091 VEC(qualified_typedef_usage_t,gc) *result = NULL;
19093 if (!t || t == error_mark_node)
19096 if (!(ti = get_template_info (t)))
19099 if (CLASS_TYPE_P (t)
19100 || TREE_CODE (t) == FUNCTION_DECL)
19102 if (!TI_TEMPLATE (ti))
19105 result = TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti);
19111 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
19112 tied to T. That list of typedefs will be access checked at
19113 T instantiation time.
19114 T is either a FUNCTION_DECL or a RECORD_TYPE.
19115 TYPE_DECL is a TYPE_DECL node representing a typedef.
19116 SCOPE is the scope through which TYPE_DECL is accessed.
19117 LOCATION is the location of the usage point of TYPE_DECL.
19119 This function is a subroutine of
19120 append_type_to_template_for_access_check. */
19123 append_type_to_template_for_access_check_1 (tree t,
19126 location_t location)
19128 qualified_typedef_usage_t typedef_usage;
19131 if (!t || t == error_mark_node)
19134 gcc_assert ((TREE_CODE (t) == FUNCTION_DECL
19135 || CLASS_TYPE_P (t))
19137 && TREE_CODE (type_decl) == TYPE_DECL
19140 if (!(ti = get_template_info (t)))
19143 gcc_assert (TI_TEMPLATE (ti));
19145 typedef_usage.typedef_decl = type_decl;
19146 typedef_usage.context = scope;
19147 typedef_usage.locus = location;
19149 VEC_safe_push (qualified_typedef_usage_t, gc,
19150 TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti),
19154 /* Append TYPE_DECL to the template TEMPL.
19155 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
19156 At TEMPL instanciation time, TYPE_DECL will be checked to see
19157 if it can be accessed through SCOPE.
19158 LOCATION is the location of the usage point of TYPE_DECL.
19160 e.g. consider the following code snippet:
19167 template<class U> struct S
19169 C::myint mi; // <-- usage point of the typedef C::myint
19174 At S<char> instantiation time, we need to check the access of C::myint
19175 In other words, we need to check the access of the myint typedef through
19176 the C scope. For that purpose, this function will add the myint typedef
19177 and the scope C through which its being accessed to a list of typedefs
19178 tied to the template S. That list will be walked at template instantiation
19179 time and access check performed on each typedefs it contains.
19180 Note that this particular code snippet should yield an error because
19181 myint is private to C. */
19184 append_type_to_template_for_access_check (tree templ,
19187 location_t location)
19189 qualified_typedef_usage_t *iter;
19192 gcc_assert (type_decl && (TREE_CODE (type_decl) == TYPE_DECL));
19194 /* Make sure we don't append the type to the template twice. */
19195 FOR_EACH_VEC_ELT (qualified_typedef_usage_t,
19196 get_types_needing_access_check (templ),
19198 if (iter->typedef_decl == type_decl && scope == iter->context)
19201 append_type_to_template_for_access_check_1 (templ, type_decl,
19205 /* Set up the hash tables for template instantiations. */
19208 init_template_processing (void)
19210 decl_specializations = htab_create_ggc (37,
19211 hash_specialization,
19212 eq_specializations,
19214 type_specializations = htab_create_ggc (37,
19215 hash_specialization,
19216 eq_specializations,
19220 /* Print stats about the template hash tables for -fstats. */
19223 print_template_statistics (void)
19225 fprintf (stderr, "decl_specializations: size %ld, %ld elements, "
19226 "%f collisions\n", (long) htab_size (decl_specializations),
19227 (long) htab_elements (decl_specializations),
19228 htab_collisions (decl_specializations));
19229 fprintf (stderr, "type_specializations: size %ld, %ld elements, "
19230 "%f collisions\n", (long) htab_size (type_specializations),
19231 (long) htab_elements (type_specializations),
19232 htab_collisions (type_specializations));
19235 #include "gt-cp-pt.h"