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 (()) 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_CHAIN (arg))
1520 val = iterative_hash_template_arg (OVL_FUNCTION (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))
1536 val = iterative_hash_object (DECL_PARM_INDEX (arg), val);
1537 return iterative_hash_template_arg (TREE_TYPE (arg), val);
1540 return iterative_hash_template_arg (TARGET_EXPR_INITIAL (arg), val);
1543 val = iterative_hash_template_arg (PTRMEM_CST_CLASS (arg), val);
1544 return iterative_hash_template_arg (PTRMEM_CST_MEMBER (arg), val);
1546 case TEMPLATE_PARM_INDEX:
1547 val = iterative_hash_template_arg
1548 (TREE_TYPE (TEMPLATE_PARM_DECL (arg)), val);
1549 val = iterative_hash_object (TEMPLATE_PARM_LEVEL (arg), val);
1550 return iterative_hash_object (TEMPLATE_PARM_IDX (arg), val);
1553 val = iterative_hash_object (TRAIT_EXPR_KIND (arg), val);
1554 val = iterative_hash_template_arg (TRAIT_EXPR_TYPE1 (arg), val);
1555 return iterative_hash_template_arg (TRAIT_EXPR_TYPE2 (arg), val);
1558 val = iterative_hash_template_arg (BINFO_TYPE (BASELINK_BINFO (arg)),
1560 return iterative_hash_template_arg (DECL_NAME (get_first_fn (arg)),
1564 val = iterative_hash_template_arg (TREE_OPERAND (arg, 0), val);
1565 code = TREE_CODE (TREE_OPERAND (arg, 1));
1566 val = iterative_hash_object (code, val);
1567 return iterative_hash_template_arg (TREE_OPERAND (arg, 2), val);
1570 /* layout_type sets structural equality for arrays of
1571 incomplete type, so we can't rely on the canonical type
1573 val = iterative_hash_template_arg (TREE_TYPE (arg), val);
1574 return iterative_hash_template_arg (TYPE_DOMAIN (arg), val);
1577 /* A lambda can't appear in a template arg, but don't crash on
1579 gcc_assert (seen_error ());
1583 case STATIC_CAST_EXPR:
1584 case REINTERPRET_CAST_EXPR:
1585 case CONST_CAST_EXPR:
1586 case DYNAMIC_CAST_EXPR:
1588 val = iterative_hash_template_arg (TREE_TYPE (arg), val);
1589 /* Now hash operands as usual. */
1599 if (TYPE_CANONICAL (arg))
1600 return iterative_hash_object (TYPE_HASH (TYPE_CANONICAL (arg)),
1602 else if (TREE_CODE (arg) == DECLTYPE_TYPE)
1603 return iterative_hash_template_arg (DECLTYPE_TYPE_EXPR (arg), val);
1604 /* Otherwise just compare the types during lookup. */
1607 case tcc_declaration:
1609 return iterative_hash_expr (arg, val);
1612 gcc_assert (IS_EXPR_CODE_CLASS (tclass));
1614 unsigned n = TREE_OPERAND_LENGTH (arg);
1615 for (i = 0; i < n; ++i)
1616 val = iterative_hash_template_arg (TREE_OPERAND (arg, i), val);
1624 /* Unregister the specialization SPEC as a specialization of TMPL.
1625 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1626 if the SPEC was listed as a specialization of TMPL.
1628 Note that SPEC has been ggc_freed, so we can't look inside it. */
1631 reregister_specialization (tree spec, tree tinfo, tree new_spec)
1636 elt.tmpl = most_general_template (TI_TEMPLATE (tinfo));
1637 elt.args = TI_ARGS (tinfo);
1638 elt.spec = NULL_TREE;
1640 slot = (spec_entry **) htab_find_slot (decl_specializations, &elt, INSERT);
1643 gcc_assert ((*slot)->spec == spec || (*slot)->spec == new_spec);
1644 gcc_assert (new_spec != NULL_TREE);
1645 (*slot)->spec = new_spec;
1652 /* Compare an entry in the local specializations hash table P1 (which
1653 is really a pointer to a TREE_LIST) with P2 (which is really a
1657 eq_local_specializations (const void *p1, const void *p2)
1659 return TREE_VALUE ((const_tree) p1) == (const_tree) p2;
1662 /* Hash P1, an entry in the local specializations table. */
1665 hash_local_specialization (const void* p1)
1667 return htab_hash_pointer (TREE_VALUE ((const_tree) p1));
1670 /* Like register_specialization, but for local declarations. We are
1671 registering SPEC, an instantiation of TMPL. */
1674 register_local_specialization (tree spec, tree tmpl)
1678 slot = htab_find_slot_with_hash (local_specializations, tmpl,
1679 htab_hash_pointer (tmpl), INSERT);
1680 *slot = build_tree_list (spec, tmpl);
1683 /* TYPE is a class type. Returns true if TYPE is an explicitly
1684 specialized class. */
1687 explicit_class_specialization_p (tree type)
1689 if (!CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
1691 return !uses_template_parms (CLASSTYPE_TI_ARGS (type));
1694 /* Print the list of functions at FNS, going through all the overloads
1695 for each element of the list. Alternatively, FNS can not be a
1696 TREE_LIST, in which case it will be printed together with all the
1699 MORE and *STR should respectively be FALSE and NULL when the function
1700 is called from the outside. They are used internally on recursive
1701 calls. print_candidates manages the two parameters and leaves NULL
1702 in *STR when it ends. */
1705 print_candidates_1 (tree fns, bool more, const char **str)
1708 char *spaces = NULL;
1710 for (fn = fns; fn; fn = OVL_NEXT (fn))
1711 if (TREE_CODE (fn) == TREE_LIST)
1713 gcc_assert (!OVL_NEXT (fn) && !is_overloaded_fn (fn));
1714 for (fn2 = fn; fn2 != NULL_TREE; fn2 = TREE_CHAIN (fn2))
1715 print_candidates_1 (TREE_VALUE (fn2),
1716 TREE_CHAIN (fn2) || more, str);
1722 /* Pick the prefix string. */
1723 if (!more && !OVL_NEXT (fns))
1725 error ("candidate is: %+#D", OVL_CURRENT (fn));
1729 *str = _("candidates are:");
1730 spaces = get_spaces (*str);
1732 error ("%s %+#D", *str, OVL_CURRENT (fn));
1733 *str = spaces ? spaces : *str;
1743 /* Print the list of candidate FNS in an error message. */
1746 print_candidates (tree fns)
1748 const char *str = NULL;
1749 print_candidates_1 (fns, false, &str);
1750 gcc_assert (str == NULL);
1753 /* Returns the template (one of the functions given by TEMPLATE_ID)
1754 which can be specialized to match the indicated DECL with the
1755 explicit template args given in TEMPLATE_ID. The DECL may be
1756 NULL_TREE if none is available. In that case, the functions in
1757 TEMPLATE_ID are non-members.
1759 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1760 specialization of a member template.
1762 The TEMPLATE_COUNT is the number of references to qualifying
1763 template classes that appeared in the name of the function. See
1764 check_explicit_specialization for a more accurate description.
1766 TSK indicates what kind of template declaration (if any) is being
1767 declared. TSK_TEMPLATE indicates that the declaration given by
1768 DECL, though a FUNCTION_DECL, has template parameters, and is
1769 therefore a template function.
1771 The template args (those explicitly specified and those deduced)
1772 are output in a newly created vector *TARGS_OUT.
1774 If it is impossible to determine the result, an error message is
1775 issued. The error_mark_node is returned to indicate failure. */
1778 determine_specialization (tree template_id,
1781 int need_member_template,
1787 tree explicit_targs;
1788 tree candidates = NULL_TREE;
1789 /* A TREE_LIST of templates of which DECL may be a specialization.
1790 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1791 corresponding TREE_PURPOSE is the set of template arguments that,
1792 when used to instantiate the template, would produce a function
1793 with the signature of DECL. */
1794 tree templates = NULL_TREE;
1796 struct cp_binding_level *b;
1798 *targs_out = NULL_TREE;
1800 if (template_id == error_mark_node || decl == error_mark_node)
1801 return error_mark_node;
1803 fns = TREE_OPERAND (template_id, 0);
1804 explicit_targs = TREE_OPERAND (template_id, 1);
1806 if (fns == error_mark_node)
1807 return error_mark_node;
1809 /* Check for baselinks. */
1810 if (BASELINK_P (fns))
1811 fns = BASELINK_FUNCTIONS (fns);
1813 if (!is_overloaded_fn (fns))
1815 error ("%qD is not a function template", fns);
1816 return error_mark_node;
1819 /* Count the number of template headers specified for this
1822 for (b = current_binding_level;
1823 b->kind == sk_template_parms;
1827 for (; fns; fns = OVL_NEXT (fns))
1829 tree fn = OVL_CURRENT (fns);
1831 if (TREE_CODE (fn) == TEMPLATE_DECL)
1833 tree decl_arg_types;
1836 /* In case of explicit specialization, we need to check if
1837 the number of template headers appearing in the specialization
1838 is correct. This is usually done in check_explicit_specialization,
1839 but the check done there cannot be exhaustive when specializing
1840 member functions. Consider the following code:
1842 template <> void A<int>::f(int);
1843 template <> template <> void A<int>::f(int);
1845 Assuming that A<int> is not itself an explicit specialization
1846 already, the first line specializes "f" which is a non-template
1847 member function, whilst the second line specializes "f" which
1848 is a template member function. So both lines are syntactically
1849 correct, and check_explicit_specialization does not reject
1852 Here, we can do better, as we are matching the specialization
1853 against the declarations. We count the number of template
1854 headers, and we check if they match TEMPLATE_COUNT + 1
1855 (TEMPLATE_COUNT is the number of qualifying template classes,
1856 plus there must be another header for the member template
1859 Notice that if header_count is zero, this is not a
1860 specialization but rather a template instantiation, so there
1861 is no check we can perform here. */
1862 if (header_count && header_count != template_count + 1)
1865 /* Check that the number of template arguments at the
1866 innermost level for DECL is the same as for FN. */
1867 if (current_binding_level->kind == sk_template_parms
1868 && !current_binding_level->explicit_spec_p
1869 && (TREE_VEC_LENGTH (DECL_INNERMOST_TEMPLATE_PARMS (fn))
1870 != TREE_VEC_LENGTH (INNERMOST_TEMPLATE_PARMS
1871 (current_template_parms))))
1874 /* DECL might be a specialization of FN. */
1875 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1876 fn_arg_types = TYPE_ARG_TYPES (TREE_TYPE (fn));
1878 /* For a non-static member function, we need to make sure
1879 that the const qualification is the same. Since
1880 get_bindings does not try to merge the "this" parameter,
1881 we must do the comparison explicitly. */
1882 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
1883 && !same_type_p (TREE_VALUE (fn_arg_types),
1884 TREE_VALUE (decl_arg_types)))
1887 /* Skip the "this" parameter and, for constructors of
1888 classes with virtual bases, the VTT parameter. A
1889 full specialization of a constructor will have a VTT
1890 parameter, but a template never will. */
1892 = skip_artificial_parms_for (decl, decl_arg_types);
1894 = skip_artificial_parms_for (fn, fn_arg_types);
1896 /* Check that the number of function parameters matches.
1898 template <class T> void f(int i = 0);
1899 template <> void f<int>();
1900 The specialization f<int> is invalid but is not caught
1901 by get_bindings below. */
1902 if (list_length (fn_arg_types) != list_length (decl_arg_types))
1905 /* Function templates cannot be specializations; there are
1906 no partial specializations of functions. Therefore, if
1907 the type of DECL does not match FN, there is no
1909 if (tsk == tsk_template)
1911 if (compparms (fn_arg_types, decl_arg_types))
1912 candidates = tree_cons (NULL_TREE, fn, candidates);
1916 /* See whether this function might be a specialization of this
1918 targs = get_bindings (fn, decl, explicit_targs, /*check_ret=*/true);
1921 /* We cannot deduce template arguments that when used to
1922 specialize TMPL will produce DECL. */
1925 /* Save this template, and the arguments deduced. */
1926 templates = tree_cons (targs, fn, templates);
1928 else if (need_member_template)
1929 /* FN is an ordinary member function, and we need a
1930 specialization of a member template. */
1932 else if (TREE_CODE (fn) != FUNCTION_DECL)
1933 /* We can get IDENTIFIER_NODEs here in certain erroneous
1936 else if (!DECL_FUNCTION_MEMBER_P (fn))
1937 /* This is just an ordinary non-member function. Nothing can
1938 be a specialization of that. */
1940 else if (DECL_ARTIFICIAL (fn))
1941 /* Cannot specialize functions that are created implicitly. */
1945 tree decl_arg_types;
1947 /* This is an ordinary member function. However, since
1948 we're here, we can assume it's enclosing class is a
1949 template class. For example,
1951 template <typename T> struct S { void f(); };
1952 template <> void S<int>::f() {}
1954 Here, S<int>::f is a non-template, but S<int> is a
1955 template class. If FN has the same type as DECL, we
1956 might be in business. */
1958 if (!DECL_TEMPLATE_INFO (fn))
1959 /* Its enclosing class is an explicit specialization
1960 of a template class. This is not a candidate. */
1963 if (!same_type_p (TREE_TYPE (TREE_TYPE (decl)),
1964 TREE_TYPE (TREE_TYPE (fn))))
1965 /* The return types differ. */
1968 /* Adjust the type of DECL in case FN is a static member. */
1969 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1970 if (DECL_STATIC_FUNCTION_P (fn)
1971 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1972 decl_arg_types = TREE_CHAIN (decl_arg_types);
1974 if (compparms (TYPE_ARG_TYPES (TREE_TYPE (fn)),
1977 candidates = tree_cons (NULL_TREE, fn, candidates);
1981 if (templates && TREE_CHAIN (templates))
1987 It is possible for a specialization with a given function
1988 signature to be instantiated from more than one function
1989 template. In such cases, explicit specification of the
1990 template arguments must be used to uniquely identify the
1991 function template specialization being specialized.
1993 Note that here, there's no suggestion that we're supposed to
1994 determine which of the candidate templates is most
1995 specialized. However, we, also have:
1999 Partial ordering of overloaded function template
2000 declarations is used in the following contexts to select
2001 the function template to which a function template
2002 specialization refers:
2004 -- when an explicit specialization refers to a function
2007 So, we do use the partial ordering rules, at least for now.
2008 This extension can only serve to make invalid programs valid,
2009 so it's safe. And, there is strong anecdotal evidence that
2010 the committee intended the partial ordering rules to apply;
2011 the EDG front end has that behavior, and John Spicer claims
2012 that the committee simply forgot to delete the wording in
2013 [temp.expl.spec]. */
2014 tree tmpl = most_specialized_instantiation (templates);
2015 if (tmpl != error_mark_node)
2018 TREE_CHAIN (templates) = NULL_TREE;
2022 if (templates == NULL_TREE && candidates == NULL_TREE)
2024 error ("template-id %qD for %q+D does not match any template "
2025 "declaration", template_id, decl);
2026 if (header_count && header_count != template_count + 1)
2027 inform (input_location, "saw %d %<template<>%>, need %d for "
2028 "specializing a member function template",
2029 header_count, template_count + 1);
2030 return error_mark_node;
2032 else if ((templates && TREE_CHAIN (templates))
2033 || (candidates && TREE_CHAIN (candidates))
2034 || (templates && candidates))
2036 error ("ambiguous template specialization %qD for %q+D",
2038 candidates = chainon (candidates, templates);
2039 print_candidates (candidates);
2040 return error_mark_node;
2043 /* We have one, and exactly one, match. */
2046 tree fn = TREE_VALUE (candidates);
2047 *targs_out = copy_node (DECL_TI_ARGS (fn));
2048 /* DECL is a re-declaration or partial instantiation of a template
2050 if (TREE_CODE (fn) == TEMPLATE_DECL)
2052 /* It was a specialization of an ordinary member function in a
2054 return DECL_TI_TEMPLATE (fn);
2057 /* It was a specialization of a template. */
2058 targs = DECL_TI_ARGS (DECL_TEMPLATE_RESULT (TREE_VALUE (templates)));
2059 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (targs))
2061 *targs_out = copy_node (targs);
2062 SET_TMPL_ARGS_LEVEL (*targs_out,
2063 TMPL_ARGS_DEPTH (*targs_out),
2064 TREE_PURPOSE (templates));
2067 *targs_out = TREE_PURPOSE (templates);
2068 return TREE_VALUE (templates);
2071 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2072 but with the default argument values filled in from those in the
2076 copy_default_args_to_explicit_spec_1 (tree spec_types,
2079 tree new_spec_types;
2084 if (spec_types == void_list_node)
2085 return void_list_node;
2087 /* Substitute into the rest of the list. */
2089 copy_default_args_to_explicit_spec_1 (TREE_CHAIN (spec_types),
2090 TREE_CHAIN (tmpl_types));
2092 /* Add the default argument for this parameter. */
2093 return hash_tree_cons (TREE_PURPOSE (tmpl_types),
2094 TREE_VALUE (spec_types),
2098 /* DECL is an explicit specialization. Replicate default arguments
2099 from the template it specializes. (That way, code like:
2101 template <class T> void f(T = 3);
2102 template <> void f(double);
2105 works, as required.) An alternative approach would be to look up
2106 the correct default arguments at the call-site, but this approach
2107 is consistent with how implicit instantiations are handled. */
2110 copy_default_args_to_explicit_spec (tree decl)
2115 tree new_spec_types;
2119 tree object_type = NULL_TREE;
2120 tree in_charge = NULL_TREE;
2121 tree vtt = NULL_TREE;
2123 /* See if there's anything we need to do. */
2124 tmpl = DECL_TI_TEMPLATE (decl);
2125 tmpl_types = TYPE_ARG_TYPES (TREE_TYPE (DECL_TEMPLATE_RESULT (tmpl)));
2126 for (t = tmpl_types; t; t = TREE_CHAIN (t))
2127 if (TREE_PURPOSE (t))
2132 old_type = TREE_TYPE (decl);
2133 spec_types = TYPE_ARG_TYPES (old_type);
2135 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2137 /* Remove the this pointer, but remember the object's type for
2139 object_type = TREE_TYPE (TREE_VALUE (spec_types));
2140 spec_types = TREE_CHAIN (spec_types);
2141 tmpl_types = TREE_CHAIN (tmpl_types);
2143 if (DECL_HAS_IN_CHARGE_PARM_P (decl))
2145 /* DECL may contain more parameters than TMPL due to the extra
2146 in-charge parameter in constructors and destructors. */
2147 in_charge = spec_types;
2148 spec_types = TREE_CHAIN (spec_types);
2150 if (DECL_HAS_VTT_PARM_P (decl))
2153 spec_types = TREE_CHAIN (spec_types);
2157 /* Compute the merged default arguments. */
2159 copy_default_args_to_explicit_spec_1 (spec_types, tmpl_types);
2161 /* Compute the new FUNCTION_TYPE. */
2165 new_spec_types = hash_tree_cons (TREE_PURPOSE (vtt),
2170 /* Put the in-charge parameter back. */
2171 new_spec_types = hash_tree_cons (TREE_PURPOSE (in_charge),
2172 TREE_VALUE (in_charge),
2175 new_type = build_method_type_directly (object_type,
2176 TREE_TYPE (old_type),
2180 new_type = build_function_type (TREE_TYPE (old_type),
2182 new_type = cp_build_type_attribute_variant (new_type,
2183 TYPE_ATTRIBUTES (old_type));
2184 new_type = build_exception_variant (new_type,
2185 TYPE_RAISES_EXCEPTIONS (old_type));
2186 TREE_TYPE (decl) = new_type;
2189 /* Check to see if the function just declared, as indicated in
2190 DECLARATOR, and in DECL, is a specialization of a function
2191 template. We may also discover that the declaration is an explicit
2192 instantiation at this point.
2194 Returns DECL, or an equivalent declaration that should be used
2195 instead if all goes well. Issues an error message if something is
2196 amiss. Returns error_mark_node if the error is not easily
2199 FLAGS is a bitmask consisting of the following flags:
2201 2: The function has a definition.
2202 4: The function is a friend.
2204 The TEMPLATE_COUNT is the number of references to qualifying
2205 template classes that appeared in the name of the function. For
2208 template <class T> struct S { void f(); };
2211 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2212 classes are not counted in the TEMPLATE_COUNT, so that in
2214 template <class T> struct S {};
2215 template <> struct S<int> { void f(); }
2216 template <> void S<int>::f();
2218 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2219 invalid; there should be no template <>.)
2221 If the function is a specialization, it is marked as such via
2222 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2223 is set up correctly, and it is added to the list of specializations
2224 for that template. */
2227 check_explicit_specialization (tree declarator,
2232 int have_def = flags & 2;
2233 int is_friend = flags & 4;
2234 int specialization = 0;
2235 int explicit_instantiation = 0;
2236 int member_specialization = 0;
2237 tree ctype = DECL_CLASS_CONTEXT (decl);
2238 tree dname = DECL_NAME (decl);
2243 if (!processing_specialization)
2246 tsk = tsk_excessive_parms;
2249 tsk = current_tmpl_spec_kind (template_count);
2254 if (processing_specialization)
2257 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2259 else if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2262 /* This could be something like:
2264 template <class T> void f(T);
2265 class S { friend void f<>(int); } */
2269 /* This case handles bogus declarations like template <>
2270 template <class T> void f<int>(); */
2272 error ("template-id %qD in declaration of primary template",
2279 case tsk_invalid_member_spec:
2280 /* The error has already been reported in
2281 check_specialization_scope. */
2282 return error_mark_node;
2284 case tsk_invalid_expl_inst:
2285 error ("template parameter list used in explicit instantiation");
2291 error ("definition provided for explicit instantiation");
2293 explicit_instantiation = 1;
2296 case tsk_excessive_parms:
2297 case tsk_insufficient_parms:
2298 if (tsk == tsk_excessive_parms)
2299 error ("too many template parameter lists in declaration of %qD",
2301 else if (template_header_count)
2302 error("too few template parameter lists in declaration of %qD", decl);
2304 error("explicit specialization of %qD must be introduced by "
2305 "%<template <>%>", decl);
2309 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2311 member_specialization = 1;
2317 if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2319 /* This case handles bogus declarations like template <>
2320 template <class T> void f<int>(); */
2322 if (uses_template_parms (declarator))
2323 error ("function template partial specialization %qD "
2324 "is not allowed", declarator);
2326 error ("template-id %qD in declaration of primary template",
2331 if (ctype && CLASSTYPE_TEMPLATE_INSTANTIATION (ctype))
2332 /* This is a specialization of a member template, without
2333 specialization the containing class. Something like:
2335 template <class T> struct S {
2336 template <class U> void f (U);
2338 template <> template <class U> void S<int>::f(U) {}
2340 That's a specialization -- but of the entire template. */
2348 if (specialization || member_specialization)
2350 tree t = TYPE_ARG_TYPES (TREE_TYPE (decl));
2351 for (; t; t = TREE_CHAIN (t))
2352 if (TREE_PURPOSE (t))
2354 permerror (input_location,
2355 "default argument specified in explicit specialization");
2360 if (specialization || member_specialization || explicit_instantiation)
2362 tree tmpl = NULL_TREE;
2363 tree targs = NULL_TREE;
2365 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2366 if (TREE_CODE (declarator) != TEMPLATE_ID_EXPR)
2370 gcc_assert (TREE_CODE (declarator) == IDENTIFIER_NODE);
2375 /* If there is no class context, the explicit instantiation
2376 must be at namespace scope. */
2377 gcc_assert (DECL_NAMESPACE_SCOPE_P (decl));
2379 /* Find the namespace binding, using the declaration
2381 fns = lookup_qualified_name (CP_DECL_CONTEXT (decl), dname,
2383 if (fns == error_mark_node || !is_overloaded_fn (fns))
2385 error ("%qD is not a template function", dname);
2386 fns = error_mark_node;
2390 tree fn = OVL_CURRENT (fns);
2391 if (!is_associated_namespace (CP_DECL_CONTEXT (decl),
2392 CP_DECL_CONTEXT (fn)))
2393 error ("%qD is not declared in %qD",
2394 decl, current_namespace);
2398 declarator = lookup_template_function (fns, NULL_TREE);
2401 if (declarator == error_mark_node)
2402 return error_mark_node;
2404 if (ctype != NULL_TREE && TYPE_BEING_DEFINED (ctype))
2406 if (!explicit_instantiation)
2407 /* A specialization in class scope. This is invalid,
2408 but the error will already have been flagged by
2409 check_specialization_scope. */
2410 return error_mark_node;
2413 /* It's not valid to write an explicit instantiation in
2416 class C { template void f(); }
2418 This case is caught by the parser. However, on
2421 template class C { void f(); };
2423 (which is invalid) we can get here. The error will be
2430 else if (ctype != NULL_TREE
2431 && (TREE_CODE (TREE_OPERAND (declarator, 0)) ==
2434 /* Find the list of functions in ctype that have the same
2435 name as the declared function. */
2436 tree name = TREE_OPERAND (declarator, 0);
2437 tree fns = NULL_TREE;
2440 if (constructor_name_p (name, ctype))
2442 int is_constructor = DECL_CONSTRUCTOR_P (decl);
2444 if (is_constructor ? !TYPE_HAS_USER_CONSTRUCTOR (ctype)
2445 : !CLASSTYPE_DESTRUCTORS (ctype))
2447 /* From [temp.expl.spec]:
2449 If such an explicit specialization for the member
2450 of a class template names an implicitly-declared
2451 special member function (clause _special_), the
2452 program is ill-formed.
2454 Similar language is found in [temp.explicit]. */
2455 error ("specialization of implicitly-declared special member function");
2456 return error_mark_node;
2459 name = is_constructor ? ctor_identifier : dtor_identifier;
2462 if (!DECL_CONV_FN_P (decl))
2464 idx = lookup_fnfields_1 (ctype, name);
2466 fns = VEC_index (tree, CLASSTYPE_METHOD_VEC (ctype), idx);
2470 VEC(tree,gc) *methods;
2473 /* For a type-conversion operator, we cannot do a
2474 name-based lookup. We might be looking for `operator
2475 int' which will be a specialization of `operator T'.
2476 So, we find *all* the conversion operators, and then
2477 select from them. */
2480 methods = CLASSTYPE_METHOD_VEC (ctype);
2482 for (idx = CLASSTYPE_FIRST_CONVERSION_SLOT;
2483 VEC_iterate (tree, methods, idx, ovl);
2486 if (!DECL_CONV_FN_P (OVL_CURRENT (ovl)))
2487 /* There are no more conversion functions. */
2490 /* Glue all these conversion functions together
2491 with those we already have. */
2492 for (; ovl; ovl = OVL_NEXT (ovl))
2493 fns = ovl_cons (OVL_CURRENT (ovl), fns);
2497 if (fns == NULL_TREE)
2499 error ("no member function %qD declared in %qT", name, ctype);
2500 return error_mark_node;
2503 TREE_OPERAND (declarator, 0) = fns;
2506 /* Figure out what exactly is being specialized at this point.
2507 Note that for an explicit instantiation, even one for a
2508 member function, we cannot tell apriori whether the
2509 instantiation is for a member template, or just a member
2510 function of a template class. Even if a member template is
2511 being instantiated, the member template arguments may be
2512 elided if they can be deduced from the rest of the
2514 tmpl = determine_specialization (declarator, decl,
2516 member_specialization,
2520 if (!tmpl || tmpl == error_mark_node)
2521 /* We couldn't figure out what this declaration was
2523 return error_mark_node;
2526 tree gen_tmpl = most_general_template (tmpl);
2528 if (explicit_instantiation)
2530 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2531 is done by do_decl_instantiation later. */
2533 int arg_depth = TMPL_ARGS_DEPTH (targs);
2534 int parm_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
2536 if (arg_depth > parm_depth)
2538 /* If TMPL is not the most general template (for
2539 example, if TMPL is a friend template that is
2540 injected into namespace scope), then there will
2541 be too many levels of TARGS. Remove some of them
2546 new_targs = make_tree_vec (parm_depth);
2547 for (i = arg_depth - parm_depth; i < arg_depth; ++i)
2548 TREE_VEC_ELT (new_targs, i - (arg_depth - parm_depth))
2549 = TREE_VEC_ELT (targs, i);
2553 return instantiate_template (tmpl, targs, tf_error);
2556 /* If we thought that the DECL was a member function, but it
2557 turns out to be specializing a static member function,
2558 make DECL a static member function as well. */
2559 if (DECL_STATIC_FUNCTION_P (tmpl)
2560 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2561 revert_static_member_fn (decl);
2563 /* If this is a specialization of a member template of a
2564 template class, we want to return the TEMPLATE_DECL, not
2565 the specialization of it. */
2566 if (tsk == tsk_template)
2568 tree result = DECL_TEMPLATE_RESULT (tmpl);
2569 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
2570 DECL_INITIAL (result) = NULL_TREE;
2574 DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl);
2575 DECL_SOURCE_LOCATION (result)
2576 = DECL_SOURCE_LOCATION (decl);
2577 /* We want to use the argument list specified in the
2578 definition, not in the original declaration. */
2579 DECL_ARGUMENTS (result) = DECL_ARGUMENTS (decl);
2580 for (parm = DECL_ARGUMENTS (result); parm;
2581 parm = DECL_CHAIN (parm))
2582 DECL_CONTEXT (parm) = result;
2584 return register_specialization (tmpl, gen_tmpl, targs,
2588 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2589 DECL_TEMPLATE_INFO (decl) = build_template_info (tmpl, targs);
2591 /* Inherit default function arguments from the template
2592 DECL is specializing. */
2593 copy_default_args_to_explicit_spec (decl);
2595 /* This specialization has the same protection as the
2596 template it specializes. */
2597 TREE_PRIVATE (decl) = TREE_PRIVATE (gen_tmpl);
2598 TREE_PROTECTED (decl) = TREE_PROTECTED (gen_tmpl);
2600 /* 7.1.1-1 [dcl.stc]
2602 A storage-class-specifier shall not be specified in an
2603 explicit specialization...
2605 The parser rejects these, so unless action is taken here,
2606 explicit function specializations will always appear with
2609 The action recommended by the C++ CWG in response to C++
2610 defect report 605 is to make the storage class and linkage
2611 of the explicit specialization match the templated function:
2613 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2615 if (tsk == tsk_expl_spec && DECL_FUNCTION_TEMPLATE_P (gen_tmpl))
2617 tree tmpl_func = DECL_TEMPLATE_RESULT (gen_tmpl);
2618 gcc_assert (TREE_CODE (tmpl_func) == FUNCTION_DECL);
2620 /* This specialization has the same linkage and visibility as
2621 the function template it specializes. */
2622 TREE_PUBLIC (decl) = TREE_PUBLIC (tmpl_func);
2623 if (! TREE_PUBLIC (decl))
2625 DECL_INTERFACE_KNOWN (decl) = 1;
2626 DECL_NOT_REALLY_EXTERN (decl) = 1;
2628 DECL_THIS_STATIC (decl) = DECL_THIS_STATIC (tmpl_func);
2629 if (DECL_VISIBILITY_SPECIFIED (tmpl_func))
2631 DECL_VISIBILITY_SPECIFIED (decl) = 1;
2632 DECL_VISIBILITY (decl) = DECL_VISIBILITY (tmpl_func);
2636 /* If DECL is a friend declaration, declared using an
2637 unqualified name, the namespace associated with DECL may
2638 have been set incorrectly. For example, in:
2640 template <typename T> void f(T);
2642 struct S { friend void f<int>(int); }
2645 we will have set the DECL_CONTEXT for the friend
2646 declaration to N, rather than to the global namespace. */
2647 if (DECL_NAMESPACE_SCOPE_P (decl))
2648 DECL_CONTEXT (decl) = DECL_CONTEXT (tmpl);
2650 if (is_friend && !have_def)
2651 /* This is not really a declaration of a specialization.
2652 It's just the name of an instantiation. But, it's not
2653 a request for an instantiation, either. */
2654 SET_DECL_IMPLICIT_INSTANTIATION (decl);
2655 else if (DECL_CONSTRUCTOR_P (decl) || DECL_DESTRUCTOR_P (decl))
2656 /* This is indeed a specialization. In case of constructors
2657 and destructors, we need in-charge and not-in-charge
2658 versions in V3 ABI. */
2659 clone_function_decl (decl, /*update_method_vec_p=*/0);
2661 /* Register this specialization so that we can find it
2663 decl = register_specialization (decl, gen_tmpl, targs, is_friend, 0);
2670 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2671 parameters. These are represented in the same format used for
2672 DECL_TEMPLATE_PARMS. */
2675 comp_template_parms (const_tree parms1, const_tree parms2)
2680 if (parms1 == parms2)
2683 for (p1 = parms1, p2 = parms2;
2684 p1 != NULL_TREE && p2 != NULL_TREE;
2685 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2))
2687 tree t1 = TREE_VALUE (p1);
2688 tree t2 = TREE_VALUE (p2);
2691 gcc_assert (TREE_CODE (t1) == TREE_VEC);
2692 gcc_assert (TREE_CODE (t2) == TREE_VEC);
2694 if (TREE_VEC_LENGTH (t1) != TREE_VEC_LENGTH (t2))
2697 for (i = 0; i < TREE_VEC_LENGTH (t2); ++i)
2699 tree parm1 = TREE_VALUE (TREE_VEC_ELT (t1, i));
2700 tree parm2 = TREE_VALUE (TREE_VEC_ELT (t2, i));
2702 /* If either of the template parameters are invalid, assume
2703 they match for the sake of error recovery. */
2704 if (parm1 == error_mark_node || parm2 == error_mark_node)
2707 if (TREE_CODE (parm1) != TREE_CODE (parm2))
2710 if (TREE_CODE (parm1) == TEMPLATE_TYPE_PARM
2711 && (TEMPLATE_TYPE_PARAMETER_PACK (parm1)
2712 == TEMPLATE_TYPE_PARAMETER_PACK (parm2)))
2714 else if (!same_type_p (TREE_TYPE (parm1), TREE_TYPE (parm2)))
2719 if ((p1 != NULL_TREE) != (p2 != NULL_TREE))
2720 /* One set of parameters has more parameters lists than the
2727 /* Determine whether PARM is a parameter pack. */
2730 template_parameter_pack_p (const_tree parm)
2732 /* Determine if we have a non-type template parameter pack. */
2733 if (TREE_CODE (parm) == PARM_DECL)
2734 return (DECL_TEMPLATE_PARM_P (parm)
2735 && TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)));
2737 /* If this is a list of template parameters, we could get a
2738 TYPE_DECL or a TEMPLATE_DECL. */
2739 if (TREE_CODE (parm) == TYPE_DECL || TREE_CODE (parm) == TEMPLATE_DECL)
2740 parm = TREE_TYPE (parm);
2742 return ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
2743 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM)
2744 && TEMPLATE_TYPE_PARAMETER_PACK (parm));
2747 /* Determine if T is a function parameter pack. */
2750 function_parameter_pack_p (const_tree t)
2752 if (t && TREE_CODE (t) == PARM_DECL)
2753 return FUNCTION_PARAMETER_PACK_P (t);
2757 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2758 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2761 get_function_template_decl (const_tree primary_func_tmpl_inst)
2763 if (! primary_func_tmpl_inst
2764 || TREE_CODE (primary_func_tmpl_inst) != FUNCTION_DECL
2765 || ! primary_template_instantiation_p (primary_func_tmpl_inst))
2768 return DECL_TEMPLATE_RESULT (DECL_TI_TEMPLATE (primary_func_tmpl_inst));
2771 /* Return true iff the function parameter PARAM_DECL was expanded
2772 from the function parameter pack PACK. */
2775 function_parameter_expanded_from_pack_p (tree param_decl, tree pack)
2777 if (DECL_ARTIFICIAL (param_decl)
2778 || !function_parameter_pack_p (pack))
2781 /* The parameter pack and its pack arguments have the same
2783 return DECL_PARM_INDEX (pack) == DECL_PARM_INDEX (param_decl);
2786 /* Determine whether ARGS describes a variadic template args list,
2787 i.e., one that is terminated by a template argument pack. */
2790 template_args_variadic_p (tree args)
2795 if (args == NULL_TREE)
2798 args = INNERMOST_TEMPLATE_ARGS (args);
2799 nargs = TREE_VEC_LENGTH (args);
2804 last_parm = TREE_VEC_ELT (args, nargs - 1);
2806 return ARGUMENT_PACK_P (last_parm);
2809 /* Generate a new name for the parameter pack name NAME (an
2810 IDENTIFIER_NODE) that incorporates its */
2813 make_ith_pack_parameter_name (tree name, int i)
2815 /* Munge the name to include the parameter index. */
2816 #define NUMBUF_LEN 128
2817 char numbuf[NUMBUF_LEN];
2821 snprintf (numbuf, NUMBUF_LEN, "%i", i);
2822 newname_len = IDENTIFIER_LENGTH (name)
2823 + strlen (numbuf) + 2;
2824 newname = (char*)alloca (newname_len);
2825 snprintf (newname, newname_len,
2826 "%s#%i", IDENTIFIER_POINTER (name), i);
2827 return get_identifier (newname);
2830 /* Return true if T is a primary function
2831 or class template instantiation. */
2834 primary_template_instantiation_p (const_tree t)
2839 if (TREE_CODE (t) == FUNCTION_DECL)
2840 return DECL_LANG_SPECIFIC (t)
2841 && DECL_TEMPLATE_INSTANTIATION (t)
2842 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (t));
2843 else if (CLASS_TYPE_P (t))
2844 return CLASSTYPE_TEMPLATE_INSTANTIATION (t)
2845 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (t));
2849 /* Return true if PARM is a template template parameter. */
2852 template_template_parameter_p (const_tree parm)
2854 return DECL_TEMPLATE_TEMPLATE_PARM_P (parm);
2857 /* Return the template parameters of T if T is a
2858 primary template instantiation, NULL otherwise. */
2861 get_primary_template_innermost_parameters (const_tree t)
2863 tree parms = NULL, template_info = NULL;
2865 if ((template_info = get_template_info (t))
2866 && primary_template_instantiation_p (t))
2867 parms = INNERMOST_TEMPLATE_PARMS
2868 (DECL_TEMPLATE_PARMS (TI_TEMPLATE (template_info)));
2873 /* Return the template parameters of the LEVELth level from the full list
2874 of template parameters PARMS. */
2877 get_template_parms_at_level (tree parms, int level)
2881 || TREE_CODE (parms) != TREE_LIST
2882 || level > TMPL_PARMS_DEPTH (parms))
2885 for (p = parms; p; p = TREE_CHAIN (p))
2886 if (TMPL_PARMS_DEPTH (p) == level)
2892 /* Returns the template arguments of T if T is a template instantiation,
2896 get_template_innermost_arguments (const_tree t)
2898 tree args = NULL, template_info = NULL;
2900 if ((template_info = get_template_info (t))
2901 && TI_ARGS (template_info))
2902 args = INNERMOST_TEMPLATE_ARGS (TI_ARGS (template_info));
2907 /* Return the argument pack elements of T if T is a template argument pack,
2911 get_template_argument_pack_elems (const_tree t)
2913 if (TREE_CODE (t) != TYPE_ARGUMENT_PACK
2914 && TREE_CODE (t) != NONTYPE_ARGUMENT_PACK)
2917 return ARGUMENT_PACK_ARGS (t);
2920 /* Structure used to track the progress of find_parameter_packs_r. */
2921 struct find_parameter_pack_data
2923 /* TREE_LIST that will contain all of the parameter packs found by
2925 tree* parameter_packs;
2927 /* Set of AST nodes that have been visited by the traversal. */
2928 struct pointer_set_t *visited;
2931 /* Identifies all of the argument packs that occur in a template
2932 argument and appends them to the TREE_LIST inside DATA, which is a
2933 find_parameter_pack_data structure. This is a subroutine of
2934 make_pack_expansion and uses_parameter_packs. */
2936 find_parameter_packs_r (tree *tp, int *walk_subtrees, void* data)
2939 struct find_parameter_pack_data* ppd =
2940 (struct find_parameter_pack_data*)data;
2941 bool parameter_pack_p = false;
2943 /* Identify whether this is a parameter pack or not. */
2944 switch (TREE_CODE (t))
2946 case TEMPLATE_PARM_INDEX:
2947 if (TEMPLATE_PARM_PARAMETER_PACK (t))
2948 parameter_pack_p = true;
2951 case TEMPLATE_TYPE_PARM:
2952 case TEMPLATE_TEMPLATE_PARM:
2953 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
2954 parameter_pack_p = true;
2958 if (FUNCTION_PARAMETER_PACK_P (t))
2960 /* We don't want to walk into the type of a PARM_DECL,
2961 because we don't want to see the type parameter pack. */
2963 parameter_pack_p = true;
2968 /* Not a parameter pack. */
2972 if (parameter_pack_p)
2974 /* Add this parameter pack to the list. */
2975 *ppd->parameter_packs = tree_cons (NULL_TREE, t, *ppd->parameter_packs);
2979 cp_walk_tree (&TYPE_CONTEXT (t),
2980 &find_parameter_packs_r, ppd, ppd->visited);
2982 /* This switch statement will return immediately if we don't find a
2984 switch (TREE_CODE (t))
2986 case TEMPLATE_PARM_INDEX:
2989 case BOUND_TEMPLATE_TEMPLATE_PARM:
2990 /* Check the template itself. */
2991 cp_walk_tree (&TREE_TYPE (TYPE_TI_TEMPLATE (t)),
2992 &find_parameter_packs_r, ppd, ppd->visited);
2993 /* Check the template arguments. */
2994 cp_walk_tree (&TYPE_TI_ARGS (t), &find_parameter_packs_r, ppd,
2999 case TEMPLATE_TYPE_PARM:
3000 case TEMPLATE_TEMPLATE_PARM:
3007 if (TYPE_PTRMEMFUNC_P (t))
3013 if (TYPE_TEMPLATE_INFO (t))
3014 cp_walk_tree (&TI_ARGS (TYPE_TEMPLATE_INFO (t)),
3015 &find_parameter_packs_r, ppd, ppd->visited);
3021 cp_walk_tree (&TREE_TYPE (t),
3022 &find_parameter_packs_r, ppd, ppd->visited);
3026 cp_walk_tree (&TYPENAME_TYPE_FULLNAME (t), &find_parameter_packs_r,
3031 case TYPE_PACK_EXPANSION:
3032 case EXPR_PACK_EXPANSION:
3037 cp_walk_tree (&TYPE_MAX_VALUE (t), &find_parameter_packs_r,
3042 case IDENTIFIER_NODE:
3043 cp_walk_tree (&TREE_TYPE (t), &find_parameter_packs_r, ppd,
3055 /* Determines if the expression or type T uses any parameter packs. */
3057 uses_parameter_packs (tree t)
3059 tree parameter_packs = NULL_TREE;
3060 struct find_parameter_pack_data ppd;
3061 ppd.parameter_packs = ¶meter_packs;
3062 ppd.visited = pointer_set_create ();
3063 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
3064 pointer_set_destroy (ppd.visited);
3065 return parameter_packs != NULL_TREE;
3068 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3069 representation a base-class initializer into a parameter pack
3070 expansion. If all goes well, the resulting node will be an
3071 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3074 make_pack_expansion (tree arg)
3077 tree parameter_packs = NULL_TREE;
3078 bool for_types = false;
3079 struct find_parameter_pack_data ppd;
3081 if (!arg || arg == error_mark_node)
3084 if (TREE_CODE (arg) == TREE_LIST)
3086 /* The only time we will see a TREE_LIST here is for a base
3087 class initializer. In this case, the TREE_PURPOSE will be a
3088 _TYPE node (representing the base class expansion we're
3089 initializing) and the TREE_VALUE will be a TREE_LIST
3090 containing the initialization arguments.
3092 The resulting expansion looks somewhat different from most
3093 expansions. Rather than returning just one _EXPANSION, we
3094 return a TREE_LIST whose TREE_PURPOSE is a
3095 TYPE_PACK_EXPANSION containing the bases that will be
3096 initialized. The TREE_VALUE will be identical to the
3097 original TREE_VALUE, which is a list of arguments that will
3098 be passed to each base. We do not introduce any new pack
3099 expansion nodes into the TREE_VALUE (although it is possible
3100 that some already exist), because the TREE_PURPOSE and
3101 TREE_VALUE all need to be expanded together with the same
3102 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3103 resulting TREE_PURPOSE will mention the parameter packs in
3104 both the bases and the arguments to the bases. */
3107 tree parameter_packs = NULL_TREE;
3109 /* Determine which parameter packs will be used by the base
3111 ppd.visited = pointer_set_create ();
3112 ppd.parameter_packs = ¶meter_packs;
3113 cp_walk_tree (&TREE_PURPOSE (arg), &find_parameter_packs_r,
3116 if (parameter_packs == NULL_TREE)
3118 error ("base initializer expansion %<%T%> contains no parameter packs", arg);
3119 pointer_set_destroy (ppd.visited);
3120 return error_mark_node;
3123 if (TREE_VALUE (arg) != void_type_node)
3125 /* Collect the sets of parameter packs used in each of the
3126 initialization arguments. */
3127 for (value = TREE_VALUE (arg); value; value = TREE_CHAIN (value))
3129 /* Determine which parameter packs will be expanded in this
3131 cp_walk_tree (&TREE_VALUE (value), &find_parameter_packs_r,
3136 pointer_set_destroy (ppd.visited);
3138 /* Create the pack expansion type for the base type. */
3139 purpose = cxx_make_type (TYPE_PACK_EXPANSION);
3140 SET_PACK_EXPANSION_PATTERN (purpose, TREE_PURPOSE (arg));
3141 PACK_EXPANSION_PARAMETER_PACKS (purpose) = parameter_packs;
3143 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3144 they will rarely be compared to anything. */
3145 SET_TYPE_STRUCTURAL_EQUALITY (purpose);
3147 return tree_cons (purpose, TREE_VALUE (arg), NULL_TREE);
3150 if (TYPE_P (arg) || TREE_CODE (arg) == TEMPLATE_DECL)
3153 /* Build the PACK_EXPANSION_* node. */
3155 ? cxx_make_type (TYPE_PACK_EXPANSION)
3156 : make_node (EXPR_PACK_EXPANSION);
3157 SET_PACK_EXPANSION_PATTERN (result, arg);
3158 if (TREE_CODE (result) == EXPR_PACK_EXPANSION)
3160 /* Propagate type and const-expression information. */
3161 TREE_TYPE (result) = TREE_TYPE (arg);
3162 TREE_CONSTANT (result) = TREE_CONSTANT (arg);
3165 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3166 they will rarely be compared to anything. */
3167 SET_TYPE_STRUCTURAL_EQUALITY (result);
3169 /* Determine which parameter packs will be expanded. */
3170 ppd.parameter_packs = ¶meter_packs;
3171 ppd.visited = pointer_set_create ();
3172 cp_walk_tree (&arg, &find_parameter_packs_r, &ppd, ppd.visited);
3173 pointer_set_destroy (ppd.visited);
3175 /* Make sure we found some parameter packs. */
3176 if (parameter_packs == NULL_TREE)
3179 error ("expansion pattern %<%T%> contains no argument packs", arg);
3181 error ("expansion pattern %<%E%> contains no argument packs", arg);
3182 return error_mark_node;
3184 PACK_EXPANSION_PARAMETER_PACKS (result) = parameter_packs;
3189 /* Checks T for any "bare" parameter packs, which have not yet been
3190 expanded, and issues an error if any are found. This operation can
3191 only be done on full expressions or types (e.g., an expression
3192 statement, "if" condition, etc.), because we could have expressions like:
3194 foo(f(g(h(args)))...)
3196 where "args" is a parameter pack. check_for_bare_parameter_packs
3197 should not be called for the subexpressions args, h(args),
3198 g(h(args)), or f(g(h(args))), because we would produce erroneous
3201 Returns TRUE and emits an error if there were bare parameter packs,
3202 returns FALSE otherwise. */
3204 check_for_bare_parameter_packs (tree t)
3206 tree parameter_packs = NULL_TREE;
3207 struct find_parameter_pack_data ppd;
3209 if (!processing_template_decl || !t || t == error_mark_node)
3212 if (TREE_CODE (t) == TYPE_DECL)
3215 ppd.parameter_packs = ¶meter_packs;
3216 ppd.visited = pointer_set_create ();
3217 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
3218 pointer_set_destroy (ppd.visited);
3220 if (parameter_packs)
3222 error ("parameter packs not expanded with %<...%>:");
3223 while (parameter_packs)
3225 tree pack = TREE_VALUE (parameter_packs);
3226 tree name = NULL_TREE;
3228 if (TREE_CODE (pack) == TEMPLATE_TYPE_PARM
3229 || TREE_CODE (pack) == TEMPLATE_TEMPLATE_PARM)
3230 name = TYPE_NAME (pack);
3231 else if (TREE_CODE (pack) == TEMPLATE_PARM_INDEX)
3232 name = DECL_NAME (TEMPLATE_PARM_DECL (pack));
3234 name = DECL_NAME (pack);
3237 inform (input_location, " %qD", name);
3239 inform (input_location, " <anonymous>");
3241 parameter_packs = TREE_CHAIN (parameter_packs);
3250 /* Expand any parameter packs that occur in the template arguments in
3253 expand_template_argument_pack (tree args)
3255 tree result_args = NULL_TREE;
3256 int in_arg, out_arg = 0, nargs = args ? TREE_VEC_LENGTH (args) : 0;
3257 int num_result_args = -1;
3258 int non_default_args_count = -1;
3260 /* First, determine if we need to expand anything, and the number of
3261 slots we'll need. */
3262 for (in_arg = 0; in_arg < nargs; ++in_arg)
3264 tree arg = TREE_VEC_ELT (args, in_arg);
3265 if (arg == NULL_TREE)
3267 if (ARGUMENT_PACK_P (arg))
3269 int num_packed = TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg));
3270 if (num_result_args < 0)
3271 num_result_args = in_arg + num_packed;
3273 num_result_args += num_packed;
3277 if (num_result_args >= 0)
3282 /* If no expansion is necessary, we're done. */
3283 if (num_result_args < 0)
3286 /* Expand arguments. */
3287 result_args = make_tree_vec (num_result_args);
3288 if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (args))
3289 non_default_args_count =
3290 GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (args);
3291 for (in_arg = 0; in_arg < nargs; ++in_arg)
3293 tree arg = TREE_VEC_ELT (args, in_arg);
3294 if (ARGUMENT_PACK_P (arg))
3296 tree packed = ARGUMENT_PACK_ARGS (arg);
3297 int i, num_packed = TREE_VEC_LENGTH (packed);
3298 for (i = 0; i < num_packed; ++i, ++out_arg)
3299 TREE_VEC_ELT (result_args, out_arg) = TREE_VEC_ELT(packed, i);
3300 if (non_default_args_count > 0)
3301 non_default_args_count += num_packed;
3305 TREE_VEC_ELT (result_args, out_arg) = arg;
3309 if (non_default_args_count >= 0)
3310 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (result_args, non_default_args_count);
3314 /* Checks if DECL shadows a template parameter.
3316 [temp.local]: A template-parameter shall not be redeclared within its
3317 scope (including nested scopes).
3319 Emits an error and returns TRUE if the DECL shadows a parameter,
3320 returns FALSE otherwise. */
3323 check_template_shadow (tree decl)
3327 /* If we're not in a template, we can't possibly shadow a template
3329 if (!current_template_parms)
3332 /* Figure out what we're shadowing. */
3333 if (TREE_CODE (decl) == OVERLOAD)
3334 decl = OVL_CURRENT (decl);
3335 olddecl = innermost_non_namespace_value (DECL_NAME (decl));
3337 /* If there's no previous binding for this name, we're not shadowing
3338 anything, let alone a template parameter. */
3342 /* If we're not shadowing a template parameter, we're done. Note
3343 that OLDDECL might be an OVERLOAD (or perhaps even an
3344 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3346 if (!DECL_P (olddecl) || !DECL_TEMPLATE_PARM_P (olddecl))
3349 /* We check for decl != olddecl to avoid bogus errors for using a
3350 name inside a class. We check TPFI to avoid duplicate errors for
3351 inline member templates. */
3353 || TEMPLATE_PARMS_FOR_INLINE (current_template_parms))
3356 error ("declaration of %q+#D", decl);
3357 error (" shadows template parm %q+#D", olddecl);
3361 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3362 ORIG_LEVEL, DECL, and TYPE. NUM_SIBLINGS is the total number of
3363 template parameters. */
3366 build_template_parm_index (int index,
3373 tree t = make_node (TEMPLATE_PARM_INDEX);
3374 TEMPLATE_PARM_IDX (t) = index;
3375 TEMPLATE_PARM_LEVEL (t) = level;
3376 TEMPLATE_PARM_ORIG_LEVEL (t) = orig_level;
3377 TEMPLATE_PARM_NUM_SIBLINGS (t) = num_siblings;
3378 TEMPLATE_PARM_DECL (t) = decl;
3379 TREE_TYPE (t) = type;
3380 TREE_CONSTANT (t) = TREE_CONSTANT (decl);
3381 TREE_READONLY (t) = TREE_READONLY (decl);
3386 /* Find the canonical type parameter for the given template type
3387 parameter. Returns the canonical type parameter, which may be TYPE
3388 if no such parameter existed. */
3391 canonical_type_parameter (tree type)
3394 int idx = TEMPLATE_TYPE_IDX (type);
3395 if (!canonical_template_parms)
3396 canonical_template_parms = VEC_alloc (tree, gc, idx+1);
3398 while (VEC_length (tree, canonical_template_parms) <= (unsigned)idx)
3399 VEC_safe_push (tree, gc, canonical_template_parms, NULL_TREE);
3401 list = VEC_index (tree, canonical_template_parms, idx);
3402 while (list && !comptypes (type, TREE_VALUE (list), COMPARE_STRUCTURAL))
3403 list = TREE_CHAIN (list);
3406 return TREE_VALUE (list);
3409 VEC_replace(tree, canonical_template_parms, idx,
3410 tree_cons (NULL_TREE, type,
3411 VEC_index (tree, canonical_template_parms, idx)));
3416 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3417 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3418 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3419 new one is created. */
3422 reduce_template_parm_level (tree index, tree type, int levels, tree args,
3423 tsubst_flags_t complain)
3425 if (TEMPLATE_PARM_DESCENDANTS (index) == NULL_TREE
3426 || (TEMPLATE_PARM_LEVEL (TEMPLATE_PARM_DESCENDANTS (index))
3427 != TEMPLATE_PARM_LEVEL (index) - levels)
3428 || !same_type_p (type, TREE_TYPE (TEMPLATE_PARM_DESCENDANTS (index))))
3430 tree orig_decl = TEMPLATE_PARM_DECL (index);
3433 decl = build_decl (DECL_SOURCE_LOCATION (orig_decl),
3434 TREE_CODE (orig_decl), DECL_NAME (orig_decl), type);
3435 TREE_CONSTANT (decl) = TREE_CONSTANT (orig_decl);
3436 TREE_READONLY (decl) = TREE_READONLY (orig_decl);
3437 DECL_ARTIFICIAL (decl) = 1;
3438 SET_DECL_TEMPLATE_PARM_P (decl);
3440 t = build_template_parm_index (TEMPLATE_PARM_IDX (index),
3441 TEMPLATE_PARM_LEVEL (index) - levels,
3442 TEMPLATE_PARM_ORIG_LEVEL (index),
3443 TEMPLATE_PARM_NUM_SIBLINGS (index),
3445 TEMPLATE_PARM_DESCENDANTS (index) = t;
3446 TEMPLATE_PARM_PARAMETER_PACK (t)
3447 = TEMPLATE_PARM_PARAMETER_PACK (index);
3449 /* Template template parameters need this. */
3450 if (TREE_CODE (decl) == TEMPLATE_DECL)
3451 DECL_TEMPLATE_PARMS (decl) = tsubst_template_parms
3452 (DECL_TEMPLATE_PARMS (TEMPLATE_PARM_DECL (index)),
3456 return TEMPLATE_PARM_DESCENDANTS (index);
3459 /* Process information from new template parameter PARM and append it
3460 to the LIST being built. This new parameter is a non-type
3461 parameter iff IS_NON_TYPE is true. This new parameter is a
3462 parameter pack iff IS_PARAMETER_PACK is true. The location of PARM
3463 is in PARM_LOC. NUM_TEMPLATE_PARMS is the size of the template
3464 parameter list PARM belongs to. This is used used to create a
3465 proper canonical type for the type of PARM that is to be created,
3466 iff PARM is a type. If the size is not known, this parameter shall
3470 process_template_parm (tree list, location_t parm_loc, tree parm,
3471 bool is_non_type, bool is_parameter_pack,
3472 unsigned num_template_parms)
3479 gcc_assert (TREE_CODE (parm) == TREE_LIST);
3480 defval = TREE_PURPOSE (parm);
3484 tree p = tree_last (list);
3486 if (p && TREE_VALUE (p) != error_mark_node)
3489 if (TREE_CODE (p) == TYPE_DECL || TREE_CODE (p) == TEMPLATE_DECL)
3490 idx = TEMPLATE_TYPE_IDX (TREE_TYPE (p));
3492 idx = TEMPLATE_PARM_IDX (DECL_INITIAL (p));
3502 parm = TREE_VALUE (parm);
3504 SET_DECL_TEMPLATE_PARM_P (parm);
3506 if (TREE_TYPE (parm) == error_mark_node)
3508 err_parm_list = build_tree_list (defval, parm);
3509 TREE_VALUE (err_parm_list) = error_mark_node;
3510 return chainon (list, err_parm_list);
3516 The top-level cv-qualifiers on the template-parameter are
3517 ignored when determining its type. */
3518 TREE_TYPE (parm) = TYPE_MAIN_VARIANT (TREE_TYPE (parm));
3519 if (invalid_nontype_parm_type_p (TREE_TYPE (parm), 1))
3521 err_parm_list = build_tree_list (defval, parm);
3522 TREE_VALUE (err_parm_list) = error_mark_node;
3523 return chainon (list, err_parm_list);
3526 if (uses_parameter_packs (TREE_TYPE (parm)) && !is_parameter_pack)
3528 /* This template parameter is not a parameter pack, but it
3529 should be. Complain about "bare" parameter packs. */
3530 check_for_bare_parameter_packs (TREE_TYPE (parm));
3532 /* Recover by calling this a parameter pack. */
3533 is_parameter_pack = true;
3537 /* A template parameter is not modifiable. */
3538 TREE_CONSTANT (parm) = 1;
3539 TREE_READONLY (parm) = 1;
3540 decl = build_decl (parm_loc,
3541 CONST_DECL, DECL_NAME (parm), TREE_TYPE (parm));
3542 TREE_CONSTANT (decl) = 1;
3543 TREE_READONLY (decl) = 1;
3544 DECL_INITIAL (parm) = DECL_INITIAL (decl)
3545 = build_template_parm_index (idx, processing_template_decl,
3546 processing_template_decl,
3548 decl, TREE_TYPE (parm));
3550 TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))
3551 = is_parameter_pack;
3556 parm = TREE_VALUE (TREE_VALUE (parm));
3558 if (parm && TREE_CODE (parm) == TEMPLATE_DECL)
3560 t = cxx_make_type (TEMPLATE_TEMPLATE_PARM);
3561 /* This is for distinguishing between real templates and template
3562 template parameters */
3563 TREE_TYPE (parm) = t;
3564 TREE_TYPE (DECL_TEMPLATE_RESULT (parm)) = t;
3569 t = cxx_make_type (TEMPLATE_TYPE_PARM);
3570 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3571 decl = build_decl (parm_loc,
3572 TYPE_DECL, parm, t);
3575 TYPE_NAME (t) = decl;
3576 TYPE_STUB_DECL (t) = decl;
3578 TEMPLATE_TYPE_PARM_INDEX (t)
3579 = build_template_parm_index (idx, processing_template_decl,
3580 processing_template_decl,
3582 decl, TREE_TYPE (parm));
3583 TEMPLATE_TYPE_PARAMETER_PACK (t) = is_parameter_pack;
3584 TYPE_CANONICAL (t) = canonical_type_parameter (t);
3586 DECL_ARTIFICIAL (decl) = 1;
3587 SET_DECL_TEMPLATE_PARM_P (decl);
3589 parm = build_tree_list (defval, parm);
3590 return chainon (list, parm);
3593 /* The end of a template parameter list has been reached. Process the
3594 tree list into a parameter vector, converting each parameter into a more
3595 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3599 end_template_parm_list (tree parms)
3603 tree saved_parmlist = make_tree_vec (list_length (parms));
3605 current_template_parms
3606 = tree_cons (size_int (processing_template_decl),
3607 saved_parmlist, current_template_parms);
3609 for (parm = parms, nparms = 0; parm; parm = next, nparms++)
3611 next = TREE_CHAIN (parm);
3612 TREE_VEC_ELT (saved_parmlist, nparms) = parm;
3613 TREE_CHAIN (parm) = NULL_TREE;
3616 --processing_template_parmlist;
3618 return saved_parmlist;
3621 /* Create a new type almost identical to TYPE but which has the
3622 following differences:
3624 1/ T has a new TEMPLATE_PARM_INDEX that carries the new number of
3625 template sibling parameters of T.
3627 2/ T has a new canonical type that matches the new number
3630 3/ From now on, T is going to be what lookups referring to the
3631 name of TYPE will return. No lookup should return TYPE anymore.
3633 NUM_PARMS is the new number of sibling parms TYPE belongs to.
3635 This is a subroutine of fixup_template_parms. */
3638 fixup_template_type_parm_type (tree type, int num_parms)
3640 tree orig_idx = TEMPLATE_TYPE_PARM_INDEX (type), idx;
3642 /* This is the decl which name is inserted into the symbol table for
3643 the template parm type. So whenever we lookup the type name, this
3644 is the DECL we get. */
3647 /* Do not fix up the type twice. */
3648 if (orig_idx && TEMPLATE_PARM_NUM_SIBLINGS (orig_idx) != 0)
3651 t = copy_type (type);
3652 decl = TYPE_NAME (t);
3654 TYPE_MAIN_VARIANT (t) = t;
3655 TYPE_NEXT_VARIANT (t)= NULL_TREE;
3656 TYPE_POINTER_TO (t) = 0;
3657 TYPE_REFERENCE_TO (t) = 0;
3659 idx = build_template_parm_index (TEMPLATE_PARM_IDX (orig_idx),
3660 TEMPLATE_PARM_LEVEL (orig_idx),
3661 TEMPLATE_PARM_ORIG_LEVEL (orig_idx),
3664 TEMPLATE_PARM_DESCENDANTS (idx) = TEMPLATE_PARM_DESCENDANTS (orig_idx);
3665 TEMPLATE_PARM_PARAMETER_PACK (idx) = TEMPLATE_PARM_PARAMETER_PACK (orig_idx);
3666 TEMPLATE_TYPE_PARM_INDEX (t) = idx;
3668 TYPE_STUB_DECL (t) = decl;
3669 TEMPLATE_TYPE_DECL (t) = decl;
3670 if (TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM)
3671 TREE_TYPE (DECL_TEMPLATE_RESULT (decl)) = t;
3673 /* Update the type associated to the type name stored in the symbol
3674 table. Now, whenever the type name is looked up, the resulting
3675 type is properly fixed up. */
3676 TREE_TYPE (decl) = t;
3678 TYPE_CANONICAL (t) = canonical_type_parameter (t);
3683 /* Create and return a new TEMPLATE_PARM_INDEX that is almost
3684 identical to I, but that is fixed up as to:
3686 1/ carry the number of sibling parms (NUM_PARMS) of the template
3687 parm represented by I.
3689 2/ replace all references to template parm types declared before I
3690 (in the same template parm list as I) by references to template
3691 parm types contained in ARGS. ARGS should contain the list of
3692 template parms that have been fixed up so far, in a form suitable
3693 to be passed to tsubst.
3695 This is a subroutine of fixup_template_parms. */
3698 fixup_template_parm_index (tree i, tree args, int num_parms)
3700 tree index, decl, type;
3703 || TREE_CODE (i) != TEMPLATE_PARM_INDEX
3704 /* Do not fix up the index twice. */
3705 || (TEMPLATE_PARM_NUM_SIBLINGS (i) != 0))
3708 decl = TEMPLATE_PARM_DECL (i);
3709 type = TREE_TYPE (decl);
3711 index = build_template_parm_index (TEMPLATE_PARM_IDX (i),
3712 TEMPLATE_PARM_LEVEL (i),
3713 TEMPLATE_PARM_ORIG_LEVEL (i),
3717 TEMPLATE_PARM_DESCENDANTS (index) = TEMPLATE_PARM_DESCENDANTS (i);
3718 TEMPLATE_PARM_PARAMETER_PACK (index) = TEMPLATE_PARM_PARAMETER_PACK (i);
3720 type = tsubst (type, args, tf_none, NULL_TREE);
3722 TREE_TYPE (decl) = type;
3723 TREE_TYPE (index) = type;
3729 This is a subroutine of fixup_template_parms.
3731 It computes the canonical type of the type of the template
3732 parameter PARM_DESC and update all references to that type so that
3733 they use the newly computed canonical type. No access check is
3734 performed during the fixup. PARM_DESC is a TREE_LIST which
3735 TREE_VALUE is the template parameter and its TREE_PURPOSE is the
3736 default argument of the template parm if any. IDX is the index of
3737 the template parameter, starting at 0. NUM_PARMS is the number of
3738 template parameters in the set PARM_DESC belongs to. ARGLIST is a
3739 TREE_VEC containing the full set of template parameters in a form
3740 suitable to be passed to substs functions as their ARGS
3741 argument. This is what current_template_args returns for a given
3742 template. The innermost vector of args in ARGLIST is the set of
3743 template parms that have been fixed up so far. This function adds
3744 the fixed up parameter into that vector. */
3747 fixup_template_parm (tree parm_desc,
3752 tree parm = TREE_VALUE (parm_desc);
3753 tree fixedup_args = INNERMOST_TEMPLATE_ARGS (arglist);
3755 push_deferring_access_checks (dk_no_check);
3757 if (TREE_CODE (parm) == TYPE_DECL)
3759 /* PARM is a template type parameter. Fix up its type, add
3760 the fixed-up template parm to the vector of fixed-up
3761 template parms so far, and substitute the fixed-up
3762 template parms into the default argument of this
3765 fixup_template_type_parm_type (TREE_TYPE (parm), num_parms);
3766 TREE_TYPE (parm) = t;
3768 TREE_VEC_ELT (fixedup_args, idx) = template_parm_to_arg (parm_desc);
3770 else if (TREE_CODE (parm) == TEMPLATE_DECL)
3772 /* PARM is a template template parameter. This is going to
3774 tree tparms, targs, innermost_args, t;
3777 /* First, fix up the parms of the template template parm
3778 because the parms are involved in defining the new canonical
3779 type of the template template parm. */
3781 /* So we need to substitute the template parm types that have
3782 been fixed up so far into the template parms of this template
3783 template parm. E.g, consider this:
3785 template<class T, template<T u> class TT> class S;
3787 In this case we want to substitute T into the
3788 template parameters of TT.
3790 So let's walk the template parms of PARM here, and
3791 tsubst ARGLIST into into each of the template
3794 /* For this substitution we need to build the full set of
3795 template parameters and use that as arguments for the
3796 tsubsting function. */
3797 tparms = INNERMOST_TEMPLATE_PARMS (DECL_TEMPLATE_PARMS (parm));
3799 /* This will contain the innermost parms of PARM into which
3800 we have substituted so far. */
3801 innermost_args = make_tree_vec (TREE_VEC_LENGTH (tparms));
3802 targs = add_to_template_args (arglist, innermost_args);
3803 for (j = 0; j < TREE_VEC_LENGTH (tparms); ++j)
3807 parameter = TREE_VEC_ELT (tparms, j);
3809 /* INNERMOST_ARGS needs to have at least the same number
3810 of elements as the index PARAMETER, ortherwise
3811 tsubsting into PARAMETER will result in partially
3812 instantiating it, reducing its tempate parm
3813 level. Let's tactically fill INNERMOST_ARGS for that
3815 TREE_VEC_ELT (innermost_args, j) =
3816 template_parm_to_arg (parameter);
3818 fixup_template_parm (parameter, j,
3819 TREE_VEC_LENGTH (tparms),
3823 /* Now fix up the type of the template template parm. */
3825 t = fixup_template_type_parm_type (TREE_TYPE (parm), num_parms);
3826 TREE_TYPE (parm) = t;
3828 TREE_VEC_ELT (fixedup_args, idx) =
3829 template_parm_to_arg (parm_desc);
3831 else if (TREE_CODE (parm) == PARM_DECL)
3833 /* PARM is a non-type template parameter. We need to:
3835 * Fix up its TEMPLATE_PARM_INDEX to make it carry the
3836 proper number of sibling parameters.
3838 * Make lookups of the template parameter return a reference
3839 to the fixed-up index. No lookup should return references
3840 to the former index anymore.
3842 * Substitute the template parms that got fixed up so far
3844 * into the type of PARM. */
3846 tree index = DECL_INITIAL (parm);
3848 /* PUSHED_DECL is the decl added to the symbol table with
3849 the name of the parameter. E,g:
3851 template<class T, T u> //#0
3852 auto my_function(T t) -> decltype(u); //#1
3854 Here, when looking up u at //#1, we get the decl of u
3855 resulting from the declaration in #0. This is what
3856 PUSHED_DECL is. We need to replace the reference to the
3857 old TEMPLATE_PARM_INDEX carried by PUSHED_DECL by the
3858 fixed-up TEMPLATE_PARM_INDEX. */
3859 tree pushed_decl = TEMPLATE_PARM_DECL (index);
3861 /* Let's fix up the TEMPLATE_PARM_INDEX then. Note that we must
3862 fixup the type of PUSHED_DECL as well and luckily
3863 fixup_template_parm_index does it for us too. */
3864 tree fixed_up_index =
3865 fixup_template_parm_index (index, arglist, num_parms);
3867 DECL_INITIAL (pushed_decl) = DECL_INITIAL (parm) = fixed_up_index;
3869 /* Add this fixed up PARM to the template parms we've fixed
3870 up so far and use that to substitute the fixed-up
3871 template parms into the type of PARM. */
3872 TREE_VEC_ELT (fixedup_args, idx) =
3873 template_parm_to_arg (parm_desc);
3874 TREE_TYPE (parm) = tsubst (TREE_TYPE (parm), arglist,
3875 tf_none, NULL_TREE);
3878 TREE_PURPOSE (parm_desc) =
3879 tsubst_template_arg (TREE_PURPOSE (parm_desc),
3880 arglist, tf_none, parm);
3882 pop_deferring_access_checks ();
3885 /* Walk the current template parms and properly compute the canonical
3886 types of the dependent types created during
3887 cp_parser_template_parameter_list. */
3890 fixup_template_parms (void)
3897 parameter_vec = INNERMOST_TEMPLATE_PARMS (current_template_parms);
3898 if (parameter_vec == NULL_TREE)
3901 num_parms = TREE_VEC_LENGTH (parameter_vec);
3903 /* This vector contains the current innermost template parms that
3904 have been fixed up so far. The form of FIXEDUP_ARGS is suitable
3905 to be passed to tsubst* functions as their ARGS argument. */
3906 fixedup_args = make_tree_vec (num_parms);
3908 /* This vector contains the full set of template parms in a form
3909 suitable to be passed to substs functions as their ARGS
3911 arglist = current_template_args ();
3912 arglist = add_outermost_template_args (arglist, fixedup_args);
3914 /* Let's do the proper fixup now. */
3915 for (i = 0; i < num_parms; ++i)
3916 fixup_template_parm (TREE_VEC_ELT (parameter_vec, i),
3917 i, num_parms, arglist);
3920 /* end_template_decl is called after a template declaration is seen. */
3923 end_template_decl (void)
3925 reset_specialization ();
3927 if (! processing_template_decl)
3930 /* This matches the pushlevel in begin_template_parm_list. */
3933 --processing_template_decl;
3934 current_template_parms = TREE_CHAIN (current_template_parms);
3937 /* Takes a TREE_LIST representing a template parameter and convert it
3938 into an argument suitable to be passed to the type substitution
3939 functions. Note that If the TREE_LIST contains an error_mark
3940 node, the returned argument is error_mark_node. */
3943 template_parm_to_arg (tree t)
3947 || TREE_CODE (t) != TREE_LIST)
3950 if (error_operand_p (TREE_VALUE (t)))
3951 return error_mark_node;
3955 if (TREE_CODE (t) == TYPE_DECL
3956 || TREE_CODE (t) == TEMPLATE_DECL)
3960 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
3962 /* Turn this argument into a TYPE_ARGUMENT_PACK
3963 with a single element, which expands T. */
3964 tree vec = make_tree_vec (1);
3965 #ifdef ENABLE_CHECKING
3966 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3967 (vec, TREE_VEC_LENGTH (vec));
3969 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
3971 t = cxx_make_type (TYPE_ARGUMENT_PACK);
3972 SET_ARGUMENT_PACK_ARGS (t, vec);
3977 t = DECL_INITIAL (t);
3979 if (TEMPLATE_PARM_PARAMETER_PACK (t))
3981 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3982 with a single element, which expands T. */
3983 tree vec = make_tree_vec (1);
3984 tree type = TREE_TYPE (TEMPLATE_PARM_DECL (t));
3985 #ifdef ENABLE_CHECKING
3986 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3987 (vec, TREE_VEC_LENGTH (vec));
3989 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
3991 t = make_node (NONTYPE_ARGUMENT_PACK);
3992 SET_ARGUMENT_PACK_ARGS (t, vec);
3993 TREE_TYPE (t) = type;
3999 /* Within the declaration of a template, return all levels of template
4000 parameters that apply. The template parameters are represented as
4001 a TREE_VEC, in the form documented in cp-tree.h for template
4005 current_template_args (void)
4008 tree args = NULL_TREE;
4009 int length = TMPL_PARMS_DEPTH (current_template_parms);
4012 /* If there is only one level of template parameters, we do not
4013 create a TREE_VEC of TREE_VECs. Instead, we return a single
4014 TREE_VEC containing the arguments. */
4016 args = make_tree_vec (length);
4018 for (header = current_template_parms; header; header = TREE_CHAIN (header))
4020 tree a = copy_node (TREE_VALUE (header));
4023 TREE_TYPE (a) = NULL_TREE;
4024 for (i = TREE_VEC_LENGTH (a) - 1; i >= 0; --i)
4025 TREE_VEC_ELT (a, i) = template_parm_to_arg (TREE_VEC_ELT (a, i));
4027 #ifdef ENABLE_CHECKING
4028 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (a, TREE_VEC_LENGTH (a));
4032 TREE_VEC_ELT (args, --l) = a;
4037 if (length > 1 && TREE_VEC_ELT (args, 0) == NULL_TREE)
4038 /* This can happen for template parms of a template template
4041 template<template<class T, class U> class TT> struct S;
4043 Consider the level of the parms of TT; T and U both have
4044 level 2; TT has no template parm of level 1. So in this case
4045 the first element of full_template_args is NULL_TREE. If we
4046 leave it like this TMPL_ARG_DEPTH on args returns 1 instead
4047 of 2. This will make tsubst wrongly consider that T and U
4048 have level 1. Instead, let's create a dummy vector as the
4049 first element of full_template_args so that TMPL_ARG_DEPTH
4050 returns the correct depth for args. */
4051 TREE_VEC_ELT (args, 0) = make_tree_vec (1);
4055 /* Update the declared TYPE by doing any lookups which were thought to be
4056 dependent, but are not now that we know the SCOPE of the declarator. */
4059 maybe_update_decl_type (tree orig_type, tree scope)
4061 tree type = orig_type;
4063 if (type == NULL_TREE)
4066 if (TREE_CODE (orig_type) == TYPE_DECL)
4067 type = TREE_TYPE (type);
4069 if (scope && TYPE_P (scope) && dependent_type_p (scope)
4070 && dependent_type_p (type)
4071 /* Don't bother building up the args in this case. */
4072 && TREE_CODE (type) != TEMPLATE_TYPE_PARM)
4074 /* tsubst in the args corresponding to the template parameters,
4075 including auto if present. Most things will be unchanged, but
4076 make_typename_type and tsubst_qualified_id will resolve
4077 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
4078 tree args = current_template_args ();
4079 tree auto_node = type_uses_auto (type);
4083 tree auto_vec = make_tree_vec (1);
4084 TREE_VEC_ELT (auto_vec, 0) = auto_node;
4085 args = add_to_template_args (args, auto_vec);
4087 pushed = push_scope (scope);
4088 type = tsubst (type, args, tf_warning_or_error, NULL_TREE);
4093 if (type == error_mark_node)
4096 if (TREE_CODE (orig_type) == TYPE_DECL)
4098 if (same_type_p (type, TREE_TYPE (orig_type)))
4101 type = TYPE_NAME (type);
4106 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
4107 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
4108 a member template. Used by push_template_decl below. */
4111 build_template_decl (tree decl, tree parms, bool member_template_p)
4113 tree tmpl = build_lang_decl (TEMPLATE_DECL, DECL_NAME (decl), NULL_TREE);
4114 DECL_TEMPLATE_PARMS (tmpl) = parms;
4115 DECL_CONTEXT (tmpl) = DECL_CONTEXT (decl);
4116 DECL_MEMBER_TEMPLATE_P (tmpl) = member_template_p;
4121 struct template_parm_data
4123 /* The level of the template parameters we are currently
4127 /* The index of the specialization argument we are currently
4131 /* An array whose size is the number of template parameters. The
4132 elements are nonzero if the parameter has been used in any one
4133 of the arguments processed so far. */
4136 /* An array whose size is the number of template arguments. The
4137 elements are nonzero if the argument makes use of template
4138 parameters of this level. */
4139 int* arg_uses_template_parms;
4142 /* Subroutine of push_template_decl used to see if each template
4143 parameter in a partial specialization is used in the explicit
4144 argument list. If T is of the LEVEL given in DATA (which is
4145 treated as a template_parm_data*), then DATA->PARMS is marked
4149 mark_template_parm (tree t, void* data)
4153 struct template_parm_data* tpd = (struct template_parm_data*) data;
4155 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
4157 level = TEMPLATE_PARM_LEVEL (t);
4158 idx = TEMPLATE_PARM_IDX (t);
4162 level = TEMPLATE_TYPE_LEVEL (t);
4163 idx = TEMPLATE_TYPE_IDX (t);
4166 if (level == tpd->level)
4168 tpd->parms[idx] = 1;
4169 tpd->arg_uses_template_parms[tpd->current_arg] = 1;
4172 /* Return zero so that for_each_template_parm will continue the
4173 traversal of the tree; we want to mark *every* template parm. */
4177 /* Process the partial specialization DECL. */
4180 process_partial_specialization (tree decl)
4182 tree type = TREE_TYPE (decl);
4183 tree maintmpl = CLASSTYPE_TI_TEMPLATE (type);
4184 tree specargs = CLASSTYPE_TI_ARGS (type);
4185 tree inner_args = INNERMOST_TEMPLATE_ARGS (specargs);
4186 tree main_inner_parms = DECL_INNERMOST_TEMPLATE_PARMS (maintmpl);
4189 int nargs = TREE_VEC_LENGTH (inner_args);
4192 bool did_error_intro = false;
4193 struct template_parm_data tpd;
4194 struct template_parm_data tpd2;
4196 gcc_assert (current_template_parms);
4198 inner_parms = INNERMOST_TEMPLATE_PARMS (current_template_parms);
4199 ntparms = TREE_VEC_LENGTH (inner_parms);
4201 /* We check that each of the template parameters given in the
4202 partial specialization is used in the argument list to the
4203 specialization. For example:
4205 template <class T> struct S;
4206 template <class T> struct S<T*>;
4208 The second declaration is OK because `T*' uses the template
4209 parameter T, whereas
4211 template <class T> struct S<int>;
4213 is no good. Even trickier is:
4224 The S2<T> declaration is actually invalid; it is a
4225 full-specialization. Of course,
4228 struct S2<T (*)(U)>;
4230 or some such would have been OK. */
4231 tpd.level = TMPL_PARMS_DEPTH (current_template_parms);
4232 tpd.parms = XALLOCAVEC (int, ntparms);
4233 memset (tpd.parms, 0, sizeof (int) * ntparms);
4235 tpd.arg_uses_template_parms = XALLOCAVEC (int, nargs);
4236 memset (tpd.arg_uses_template_parms, 0, sizeof (int) * nargs);
4237 for (i = 0; i < nargs; ++i)
4239 tpd.current_arg = i;
4240 for_each_template_parm (TREE_VEC_ELT (inner_args, i),
4241 &mark_template_parm,
4244 /*include_nondeduced_p=*/false);
4246 for (i = 0; i < ntparms; ++i)
4247 if (tpd.parms[i] == 0)
4249 /* One of the template parms was not used in the
4251 if (!did_error_intro)
4253 error ("template parameters not used in partial specialization:");
4254 did_error_intro = true;
4257 error (" %qD", TREE_VALUE (TREE_VEC_ELT (inner_parms, i)));
4260 if (did_error_intro)
4261 return error_mark_node;
4263 /* [temp.class.spec]
4265 The argument list of the specialization shall not be identical to
4266 the implicit argument list of the primary template. */
4267 if (comp_template_args
4269 INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE
4271 error ("partial specialization %qT does not specialize any template arguments", type);
4273 /* [temp.class.spec]
4275 A partially specialized non-type argument expression shall not
4276 involve template parameters of the partial specialization except
4277 when the argument expression is a simple identifier.
4279 The type of a template parameter corresponding to a specialized
4280 non-type argument shall not be dependent on a parameter of the
4283 Also, we verify that pack expansions only occur at the
4284 end of the argument list. */
4285 gcc_assert (nargs == DECL_NTPARMS (maintmpl));
4287 for (i = 0; i < nargs; ++i)
4289 tree parm = TREE_VALUE (TREE_VEC_ELT (main_inner_parms, i));
4290 tree arg = TREE_VEC_ELT (inner_args, i);
4291 tree packed_args = NULL_TREE;
4294 if (ARGUMENT_PACK_P (arg))
4296 /* Extract the arguments from the argument pack. We'll be
4297 iterating over these in the following loop. */
4298 packed_args = ARGUMENT_PACK_ARGS (arg);
4299 len = TREE_VEC_LENGTH (packed_args);
4302 for (j = 0; j < len; j++)
4305 /* Get the Jth argument in the parameter pack. */
4306 arg = TREE_VEC_ELT (packed_args, j);
4308 if (PACK_EXPANSION_P (arg))
4310 /* Pack expansions must come at the end of the
4312 if ((packed_args && j < len - 1)
4313 || (!packed_args && i < nargs - 1))
4315 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
4316 error ("parameter pack argument %qE must be at the "
4317 "end of the template argument list", arg);
4319 error ("parameter pack argument %qT must be at the "
4320 "end of the template argument list", arg);
4324 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
4325 /* We only care about the pattern. */
4326 arg = PACK_EXPANSION_PATTERN (arg);
4328 if (/* These first two lines are the `non-type' bit. */
4330 && TREE_CODE (arg) != TEMPLATE_DECL
4331 /* This next line is the `argument expression is not just a
4332 simple identifier' condition and also the `specialized
4333 non-type argument' bit. */
4334 && TREE_CODE (arg) != TEMPLATE_PARM_INDEX)
4336 if ((!packed_args && tpd.arg_uses_template_parms[i])
4337 || (packed_args && uses_template_parms (arg)))
4338 error ("template argument %qE involves template parameter(s)",
4342 /* Look at the corresponding template parameter,
4343 marking which template parameters its type depends
4345 tree type = TREE_TYPE (parm);
4349 /* We haven't yet initialized TPD2. Do so now. */
4350 tpd2.arg_uses_template_parms = XALLOCAVEC (int, nargs);
4351 /* The number of parameters here is the number in the
4352 main template, which, as checked in the assertion
4354 tpd2.parms = XALLOCAVEC (int, nargs);
4356 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (maintmpl));
4359 /* Mark the template parameters. But this time, we're
4360 looking for the template parameters of the main
4361 template, not in the specialization. */
4362 tpd2.current_arg = i;
4363 tpd2.arg_uses_template_parms[i] = 0;
4364 memset (tpd2.parms, 0, sizeof (int) * nargs);
4365 for_each_template_parm (type,
4366 &mark_template_parm,
4369 /*include_nondeduced_p=*/false);
4371 if (tpd2.arg_uses_template_parms [i])
4373 /* The type depended on some template parameters.
4374 If they are fully specialized in the
4375 specialization, that's OK. */
4378 for (j = 0; j < nargs; ++j)
4379 if (tpd2.parms[j] != 0
4380 && tpd.arg_uses_template_parms [j])
4383 error_n (input_location, count,
4384 "type %qT of template argument %qE depends "
4385 "on a template parameter",
4386 "type %qT of template argument %qE depends "
4387 "on template parameters",
4396 /* We should only get here once. */
4397 gcc_assert (!COMPLETE_TYPE_P (type));
4399 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)
4400 = tree_cons (specargs, inner_parms,
4401 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl));
4402 TREE_TYPE (DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)) = type;
4404 for (inst = DECL_TEMPLATE_INSTANTIATIONS (maintmpl); inst;
4405 inst = TREE_CHAIN (inst))
4407 tree inst_type = TREE_VALUE (inst);
4408 if (COMPLETE_TYPE_P (inst_type)
4409 && CLASSTYPE_IMPLICIT_INSTANTIATION (inst_type))
4411 tree spec = most_specialized_class (inst_type, maintmpl, tf_none);
4412 if (spec && TREE_TYPE (spec) == type)
4413 permerror (input_location,
4414 "partial specialization of %qT after instantiation "
4415 "of %qT", type, inst_type);
4422 /* Check that a template declaration's use of default arguments and
4423 parameter packs is not invalid. Here, PARMS are the template
4424 parameters. IS_PRIMARY is nonzero if DECL is the thing declared by
4425 a primary template. IS_PARTIAL is nonzero if DECL is a partial
4429 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4430 declaration (but not a definition); 1 indicates a declaration, 2
4431 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4432 emitted for extraneous default arguments.
4434 Returns TRUE if there were no errors found, FALSE otherwise. */
4437 check_default_tmpl_args (tree decl, tree parms, int is_primary,
4438 int is_partial, int is_friend_decl)
4441 int last_level_to_check;
4443 bool no_errors = true;
4447 A default template-argument shall not be specified in a
4448 function template declaration or a function template definition, nor
4449 in the template-parameter-list of the definition of a member of a
4452 if (TREE_CODE (CP_DECL_CONTEXT (decl)) == FUNCTION_DECL)
4453 /* You can't have a function template declaration in a local
4454 scope, nor you can you define a member of a class template in a
4458 if (current_class_type
4459 && !TYPE_BEING_DEFINED (current_class_type)
4460 && DECL_LANG_SPECIFIC (decl)
4461 && DECL_DECLARES_FUNCTION_P (decl)
4462 /* If this is either a friend defined in the scope of the class
4463 or a member function. */
4464 && (DECL_FUNCTION_MEMBER_P (decl)
4465 ? same_type_p (DECL_CONTEXT (decl), current_class_type)
4466 : DECL_FRIEND_CONTEXT (decl)
4467 ? same_type_p (DECL_FRIEND_CONTEXT (decl), current_class_type)
4469 /* And, if it was a member function, it really was defined in
4470 the scope of the class. */
4471 && (!DECL_FUNCTION_MEMBER_P (decl)
4472 || DECL_INITIALIZED_IN_CLASS_P (decl)))
4473 /* We already checked these parameters when the template was
4474 declared, so there's no need to do it again now. This function
4475 was defined in class scope, but we're processing it's body now
4476 that the class is complete. */
4479 /* Core issue 226 (C++0x only): the following only applies to class
4481 if ((cxx_dialect == cxx98) || TREE_CODE (decl) != FUNCTION_DECL)
4485 If a template-parameter has a default template-argument, all
4486 subsequent template-parameters shall have a default
4487 template-argument supplied. */
4488 for (parm_level = parms; parm_level; parm_level = TREE_CHAIN (parm_level))
4490 tree inner_parms = TREE_VALUE (parm_level);
4491 int ntparms = TREE_VEC_LENGTH (inner_parms);
4492 int seen_def_arg_p = 0;
4495 for (i = 0; i < ntparms; ++i)
4497 tree parm = TREE_VEC_ELT (inner_parms, i);
4499 if (parm == error_mark_node)
4502 if (TREE_PURPOSE (parm))
4504 else if (seen_def_arg_p
4505 && !template_parameter_pack_p (TREE_VALUE (parm)))
4507 error ("no default argument for %qD", TREE_VALUE (parm));
4508 /* For better subsequent error-recovery, we indicate that
4509 there should have been a default argument. */
4510 TREE_PURPOSE (parm) = error_mark_node;
4516 /* Don't complain about an enclosing partial
4518 && parm_level == parms
4519 && TREE_CODE (decl) == TYPE_DECL
4521 && template_parameter_pack_p (TREE_VALUE (parm)))
4523 /* A primary class template can only have one
4524 parameter pack, at the end of the template
4527 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL)
4528 error ("parameter pack %qE must be at the end of the"
4529 " template parameter list", TREE_VALUE (parm));
4531 error ("parameter pack %qT must be at the end of the"
4532 " template parameter list",
4533 TREE_TYPE (TREE_VALUE (parm)));
4535 TREE_VALUE (TREE_VEC_ELT (inner_parms, i))
4543 if (((cxx_dialect == cxx98) && TREE_CODE (decl) != TYPE_DECL)
4547 /* For an ordinary class template, default template arguments are
4548 allowed at the innermost level, e.g.:
4549 template <class T = int>
4551 but, in a partial specialization, they're not allowed even
4552 there, as we have in [temp.class.spec]:
4554 The template parameter list of a specialization shall not
4555 contain default template argument values.
4557 So, for a partial specialization, or for a function template
4558 (in C++98/C++03), we look at all of them. */
4561 /* But, for a primary class template that is not a partial
4562 specialization we look at all template parameters except the
4564 parms = TREE_CHAIN (parms);
4566 /* Figure out what error message to issue. */
4567 if (is_friend_decl == 2)
4568 msg = G_("default template arguments may not be used in function template "
4569 "friend re-declaration");
4570 else if (is_friend_decl)
4571 msg = G_("default template arguments may not be used in function template "
4572 "friend declarations");
4573 else if (TREE_CODE (decl) == FUNCTION_DECL && (cxx_dialect == cxx98))
4574 msg = G_("default template arguments may not be used in function templates "
4575 "without -std=c++0x or -std=gnu++0x");
4576 else if (is_partial)
4577 msg = G_("default template arguments may not be used in "
4578 "partial specializations");
4580 msg = G_("default argument for template parameter for class enclosing %qD");
4582 if (current_class_type && TYPE_BEING_DEFINED (current_class_type))
4583 /* If we're inside a class definition, there's no need to
4584 examine the parameters to the class itself. On the one
4585 hand, they will be checked when the class is defined, and,
4586 on the other, default arguments are valid in things like:
4587 template <class T = double>
4588 struct S { template <class U> void f(U); };
4589 Here the default argument for `S' has no bearing on the
4590 declaration of `f'. */
4591 last_level_to_check = template_class_depth (current_class_type) + 1;
4593 /* Check everything. */
4594 last_level_to_check = 0;
4596 for (parm_level = parms;
4597 parm_level && TMPL_PARMS_DEPTH (parm_level) >= last_level_to_check;
4598 parm_level = TREE_CHAIN (parm_level))
4600 tree inner_parms = TREE_VALUE (parm_level);
4604 ntparms = TREE_VEC_LENGTH (inner_parms);
4605 for (i = 0; i < ntparms; ++i)
4607 if (TREE_VEC_ELT (inner_parms, i) == error_mark_node)
4610 if (TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)))
4615 if (is_friend_decl == 2)
4622 /* Clear out the default argument so that we are not
4624 TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)) = NULL_TREE;
4628 /* At this point, if we're still interested in issuing messages,
4629 they must apply to classes surrounding the object declared. */
4631 msg = G_("default argument for template parameter for class "
4638 /* Worker for push_template_decl_real, called via
4639 for_each_template_parm. DATA is really an int, indicating the
4640 level of the parameters we are interested in. If T is a template
4641 parameter of that level, return nonzero. */
4644 template_parm_this_level_p (tree t, void* data)
4646 int this_level = *(int *)data;
4649 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
4650 level = TEMPLATE_PARM_LEVEL (t);
4652 level = TEMPLATE_TYPE_LEVEL (t);
4653 return level == this_level;
4656 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4657 parameters given by current_template_args, or reuses a
4658 previously existing one, if appropriate. Returns the DECL, or an
4659 equivalent one, if it is replaced via a call to duplicate_decls.
4661 If IS_FRIEND is true, DECL is a friend declaration. */
4664 push_template_decl_real (tree decl, bool is_friend)
4672 int new_template_p = 0;
4673 /* True if the template is a member template, in the sense of
4675 bool member_template_p = false;
4677 if (decl == error_mark_node || !current_template_parms)
4678 return error_mark_node;
4680 /* See if this is a partial specialization. */
4681 is_partial = (DECL_IMPLICIT_TYPEDEF_P (decl)
4682 && TREE_CODE (TREE_TYPE (decl)) != ENUMERAL_TYPE
4683 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)));
4685 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_FRIEND_P (decl))
4689 /* For a friend, we want the context of the friend function, not
4690 the type of which it is a friend. */
4691 ctx = CP_DECL_CONTEXT (decl);
4692 else if (CP_DECL_CONTEXT (decl)
4693 && TREE_CODE (CP_DECL_CONTEXT (decl)) != NAMESPACE_DECL)
4694 /* In the case of a virtual function, we want the class in which
4696 ctx = CP_DECL_CONTEXT (decl);
4698 /* Otherwise, if we're currently defining some class, the DECL
4699 is assumed to be a member of the class. */
4700 ctx = current_scope ();
4702 if (ctx && TREE_CODE (ctx) == NAMESPACE_DECL)
4705 if (!DECL_CONTEXT (decl))
4706 DECL_CONTEXT (decl) = FROB_CONTEXT (current_namespace);
4708 /* See if this is a primary template. */
4709 if (is_friend && ctx)
4710 /* A friend template that specifies a class context, i.e.
4711 template <typename T> friend void A<T>::f();
4715 primary = template_parm_scope_p ();
4719 if (DECL_CLASS_SCOPE_P (decl))
4720 member_template_p = true;
4721 if (TREE_CODE (decl) == TYPE_DECL
4722 && ANON_AGGRNAME_P (DECL_NAME (decl)))
4724 error ("template class without a name");
4725 return error_mark_node;
4727 else if (TREE_CODE (decl) == FUNCTION_DECL)
4729 if (DECL_DESTRUCTOR_P (decl))
4733 A destructor shall not be a member template. */
4734 error ("destructor %qD declared as member template", decl);
4735 return error_mark_node;
4737 if (NEW_DELETE_OPNAME_P (DECL_NAME (decl))
4738 && (!prototype_p (TREE_TYPE (decl))
4739 || TYPE_ARG_TYPES (TREE_TYPE (decl)) == void_list_node
4740 || !TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (decl)))
4741 || (TREE_CHAIN (TYPE_ARG_TYPES ((TREE_TYPE (decl))))
4742 == void_list_node)))
4744 /* [basic.stc.dynamic.allocation]
4746 An allocation function can be a function
4747 template. ... Template allocation functions shall
4748 have two or more parameters. */
4749 error ("invalid template declaration of %qD", decl);
4750 return error_mark_node;
4753 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4754 && CLASS_TYPE_P (TREE_TYPE (decl)))
4758 error ("template declaration of %q#D", decl);
4759 return error_mark_node;
4763 /* Check to see that the rules regarding the use of default
4764 arguments are not being violated. */
4765 check_default_tmpl_args (decl, current_template_parms,
4766 primary, is_partial, /*is_friend_decl=*/0);
4768 /* Ensure that there are no parameter packs in the type of this
4769 declaration that have not been expanded. */
4770 if (TREE_CODE (decl) == FUNCTION_DECL)
4772 /* Check each of the arguments individually to see if there are
4773 any bare parameter packs. */
4774 tree type = TREE_TYPE (decl);
4775 tree arg = DECL_ARGUMENTS (decl);
4776 tree argtype = TYPE_ARG_TYPES (type);
4778 while (arg && argtype)
4780 if (!FUNCTION_PARAMETER_PACK_P (arg)
4781 && check_for_bare_parameter_packs (TREE_TYPE (arg)))
4783 /* This is a PARM_DECL that contains unexpanded parameter
4784 packs. We have already complained about this in the
4785 check_for_bare_parameter_packs call, so just replace
4786 these types with ERROR_MARK_NODE. */
4787 TREE_TYPE (arg) = error_mark_node;
4788 TREE_VALUE (argtype) = error_mark_node;
4791 arg = DECL_CHAIN (arg);
4792 argtype = TREE_CHAIN (argtype);
4795 /* Check for bare parameter packs in the return type and the
4796 exception specifiers. */
4797 if (check_for_bare_parameter_packs (TREE_TYPE (type)))
4798 /* Errors were already issued, set return type to int
4799 as the frontend doesn't expect error_mark_node as
4801 TREE_TYPE (type) = integer_type_node;
4802 if (check_for_bare_parameter_packs (TYPE_RAISES_EXCEPTIONS (type)))
4803 TYPE_RAISES_EXCEPTIONS (type) = NULL_TREE;
4805 else if (check_for_bare_parameter_packs (TREE_TYPE (decl)))
4807 TREE_TYPE (decl) = error_mark_node;
4808 return error_mark_node;
4812 return process_partial_specialization (decl);
4814 args = current_template_args ();
4817 || TREE_CODE (ctx) == FUNCTION_DECL
4818 || (CLASS_TYPE_P (ctx) && TYPE_BEING_DEFINED (ctx))
4819 || (is_friend && !DECL_TEMPLATE_INFO (decl)))
4821 if (DECL_LANG_SPECIFIC (decl)
4822 && DECL_TEMPLATE_INFO (decl)
4823 && DECL_TI_TEMPLATE (decl))
4824 tmpl = DECL_TI_TEMPLATE (decl);
4825 /* If DECL is a TYPE_DECL for a class-template, then there won't
4826 be DECL_LANG_SPECIFIC. The information equivalent to
4827 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4828 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4829 && TYPE_TEMPLATE_INFO (TREE_TYPE (decl))
4830 && TYPE_TI_TEMPLATE (TREE_TYPE (decl)))
4832 /* Since a template declaration already existed for this
4833 class-type, we must be redeclaring it here. Make sure
4834 that the redeclaration is valid. */
4835 redeclare_class_template (TREE_TYPE (decl),
4836 current_template_parms);
4837 /* We don't need to create a new TEMPLATE_DECL; just use the
4838 one we already had. */
4839 tmpl = TYPE_TI_TEMPLATE (TREE_TYPE (decl));
4843 tmpl = build_template_decl (decl, current_template_parms,
4847 if (DECL_LANG_SPECIFIC (decl)
4848 && DECL_TEMPLATE_SPECIALIZATION (decl))
4850 /* A specialization of a member template of a template
4852 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
4853 DECL_TEMPLATE_INFO (tmpl) = DECL_TEMPLATE_INFO (decl);
4854 DECL_TEMPLATE_INFO (decl) = NULL_TREE;
4860 tree a, t, current, parms;
4862 tree tinfo = get_template_info (decl);
4866 error ("template definition of non-template %q#D", decl);
4867 return error_mark_node;
4870 tmpl = TI_TEMPLATE (tinfo);
4872 if (DECL_FUNCTION_TEMPLATE_P (tmpl)
4873 && DECL_TEMPLATE_INFO (decl) && DECL_TI_ARGS (decl)
4874 && DECL_TEMPLATE_SPECIALIZATION (decl)
4875 && DECL_MEMBER_TEMPLATE_P (tmpl))
4879 /* The declaration is a specialization of a member
4880 template, declared outside the class. Therefore, the
4881 innermost template arguments will be NULL, so we
4882 replace them with the arguments determined by the
4883 earlier call to check_explicit_specialization. */
4884 args = DECL_TI_ARGS (decl);
4887 = build_template_decl (decl, current_template_parms,
4889 DECL_TEMPLATE_RESULT (new_tmpl) = decl;
4890 TREE_TYPE (new_tmpl) = TREE_TYPE (decl);
4891 DECL_TI_TEMPLATE (decl) = new_tmpl;
4892 SET_DECL_TEMPLATE_SPECIALIZATION (new_tmpl);
4893 DECL_TEMPLATE_INFO (new_tmpl)
4894 = build_template_info (tmpl, args);
4896 register_specialization (new_tmpl,
4897 most_general_template (tmpl),
4903 /* Make sure the template headers we got make sense. */
4905 parms = DECL_TEMPLATE_PARMS (tmpl);
4906 i = TMPL_PARMS_DEPTH (parms);
4907 if (TMPL_ARGS_DEPTH (args) != i)
4909 error ("expected %d levels of template parms for %q#D, got %d",
4910 i, decl, TMPL_ARGS_DEPTH (args));
4913 for (current = decl; i > 0; --i, parms = TREE_CHAIN (parms))
4915 a = TMPL_ARGS_LEVEL (args, i);
4916 t = INNERMOST_TEMPLATE_PARMS (parms);
4918 if (TREE_VEC_LENGTH (t) != TREE_VEC_LENGTH (a))
4920 if (current == decl)
4921 error ("got %d template parameters for %q#D",
4922 TREE_VEC_LENGTH (a), decl);
4924 error ("got %d template parameters for %q#T",
4925 TREE_VEC_LENGTH (a), current);
4926 error (" but %d required", TREE_VEC_LENGTH (t));
4927 return error_mark_node;
4930 if (current == decl)
4932 else if (current == NULL_TREE)
4933 /* Can happen in erroneous input. */
4936 current = (TYPE_P (current)
4937 ? TYPE_CONTEXT (current)
4938 : DECL_CONTEXT (current));
4941 /* Check that the parms are used in the appropriate qualifying scopes
4942 in the declarator. */
4943 if (!comp_template_args
4945 TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (tmpl)))))
4948 template arguments to %qD do not match original template %qD",
4949 decl, DECL_TEMPLATE_RESULT (tmpl));
4950 if (!uses_template_parms (TI_ARGS (tinfo)))
4951 inform (input_location, "use template<> for an explicit specialization");
4952 /* Avoid crash in import_export_decl. */
4953 DECL_INTERFACE_KNOWN (decl) = 1;
4954 return error_mark_node;
4958 DECL_TEMPLATE_RESULT (tmpl) = decl;
4959 TREE_TYPE (tmpl) = TREE_TYPE (decl);
4961 /* Push template declarations for global functions and types. Note
4962 that we do not try to push a global template friend declared in a
4963 template class; such a thing may well depend on the template
4964 parameters of the class. */
4965 if (new_template_p && !ctx
4966 && !(is_friend && template_class_depth (current_class_type) > 0))
4968 tmpl = pushdecl_namespace_level (tmpl, is_friend);
4969 if (tmpl == error_mark_node)
4970 return error_mark_node;
4972 /* Hide template friend classes that haven't been declared yet. */
4973 if (is_friend && TREE_CODE (decl) == TYPE_DECL)
4975 DECL_ANTICIPATED (tmpl) = 1;
4976 DECL_FRIEND_P (tmpl) = 1;
4982 tree parms = DECL_TEMPLATE_PARMS (tmpl);
4985 DECL_PRIMARY_TEMPLATE (tmpl) = tmpl;
4986 if (DECL_CONV_FN_P (tmpl))
4988 int depth = TMPL_PARMS_DEPTH (parms);
4990 /* It is a conversion operator. See if the type converted to
4991 depends on innermost template operands. */
4993 if (uses_template_parms_level (TREE_TYPE (TREE_TYPE (tmpl)),
4995 DECL_TEMPLATE_CONV_FN_P (tmpl) = 1;
4998 /* Give template template parms a DECL_CONTEXT of the template
4999 for which they are a parameter. */
5000 parms = INNERMOST_TEMPLATE_PARMS (parms);
5001 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
5003 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
5004 if (TREE_CODE (parm) == TEMPLATE_DECL)
5005 DECL_CONTEXT (parm) = tmpl;
5009 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
5010 back to its most general template. If TMPL is a specialization,
5011 ARGS may only have the innermost set of arguments. Add the missing
5012 argument levels if necessary. */
5013 if (DECL_TEMPLATE_INFO (tmpl))
5014 args = add_outermost_template_args (DECL_TI_ARGS (tmpl), args);
5016 info = build_template_info (tmpl, args);
5018 if (DECL_IMPLICIT_TYPEDEF_P (decl))
5019 SET_TYPE_TEMPLATE_INFO (TREE_TYPE (tmpl), info);
5020 else if (DECL_LANG_SPECIFIC (decl))
5021 DECL_TEMPLATE_INFO (decl) = info;
5023 return DECL_TEMPLATE_RESULT (tmpl);
5027 push_template_decl (tree decl)
5029 return push_template_decl_real (decl, false);
5032 /* Called when a class template TYPE is redeclared with the indicated
5033 template PARMS, e.g.:
5035 template <class T> struct S;
5036 template <class T> struct S {}; */
5039 redeclare_class_template (tree type, tree parms)
5045 if (!TYPE_TEMPLATE_INFO (type))
5047 error ("%qT is not a template type", type);
5051 tmpl = TYPE_TI_TEMPLATE (type);
5052 if (!PRIMARY_TEMPLATE_P (tmpl))
5053 /* The type is nested in some template class. Nothing to worry
5054 about here; there are no new template parameters for the nested
5060 error ("template specifiers not specified in declaration of %qD",
5065 parms = INNERMOST_TEMPLATE_PARMS (parms);
5066 tmpl_parms = DECL_INNERMOST_TEMPLATE_PARMS (tmpl);
5068 if (TREE_VEC_LENGTH (parms) != TREE_VEC_LENGTH (tmpl_parms))
5070 error_n (input_location, TREE_VEC_LENGTH (parms),
5071 "redeclared with %d template parameter",
5072 "redeclared with %d template parameters",
5073 TREE_VEC_LENGTH (parms));
5074 inform_n (input_location, TREE_VEC_LENGTH (tmpl_parms),
5075 "previous declaration %q+D used %d template parameter",
5076 "previous declaration %q+D used %d template parameters",
5077 tmpl, TREE_VEC_LENGTH (tmpl_parms));
5081 for (i = 0; i < TREE_VEC_LENGTH (tmpl_parms); ++i)
5088 if (TREE_VEC_ELT (tmpl_parms, i) == error_mark_node
5089 || TREE_VEC_ELT (parms, i) == error_mark_node)
5092 tmpl_parm = TREE_VALUE (TREE_VEC_ELT (tmpl_parms, i));
5093 if (tmpl_parm == error_mark_node)
5096 parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
5097 tmpl_default = TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i));
5098 parm_default = TREE_PURPOSE (TREE_VEC_ELT (parms, i));
5100 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
5102 if (TREE_CODE (tmpl_parm) != TREE_CODE (parm)
5103 || (TREE_CODE (tmpl_parm) != TYPE_DECL
5104 && !same_type_p (TREE_TYPE (tmpl_parm), TREE_TYPE (parm)))
5105 || (TREE_CODE (tmpl_parm) != PARM_DECL
5106 && (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (tmpl_parm))
5107 != TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm))))
5108 || (TREE_CODE (tmpl_parm) == PARM_DECL
5109 && (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (tmpl_parm))
5110 != TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))))
5112 error ("template parameter %q+#D", tmpl_parm);
5113 error ("redeclared here as %q#D", parm);
5117 if (tmpl_default != NULL_TREE && parm_default != NULL_TREE)
5119 /* We have in [temp.param]:
5121 A template-parameter may not be given default arguments
5122 by two different declarations in the same scope. */
5123 error_at (input_location, "redefinition of default argument for %q#D", parm);
5124 inform (DECL_SOURCE_LOCATION (tmpl_parm),
5125 "original definition appeared here");
5129 if (parm_default != NULL_TREE)
5130 /* Update the previous template parameters (which are the ones
5131 that will really count) with the new default value. */
5132 TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i)) = parm_default;
5133 else if (tmpl_default != NULL_TREE)
5134 /* Update the new parameters, too; they'll be used as the
5135 parameters for any members. */
5136 TREE_PURPOSE (TREE_VEC_ELT (parms, i)) = tmpl_default;
5142 /* Simplify EXPR if it is a non-dependent expression. Returns the
5143 (possibly simplified) expression. */
5146 fold_non_dependent_expr_sfinae (tree expr, tsubst_flags_t complain)
5148 if (expr == NULL_TREE)
5151 /* If we're in a template, but EXPR isn't value dependent, simplify
5152 it. We're supposed to treat:
5154 template <typename T> void f(T[1 + 1]);
5155 template <typename T> void f(T[2]);
5157 as two declarations of the same function, for example. */
5158 if (processing_template_decl
5159 && !type_dependent_expression_p (expr)
5160 && potential_constant_expression (expr)
5161 && !value_dependent_expression_p (expr))
5163 HOST_WIDE_INT saved_processing_template_decl;
5165 saved_processing_template_decl = processing_template_decl;
5166 processing_template_decl = 0;
5167 expr = tsubst_copy_and_build (expr,
5170 /*in_decl=*/NULL_TREE,
5171 /*function_p=*/false,
5172 /*integral_constant_expression_p=*/true);
5173 processing_template_decl = saved_processing_template_decl;
5179 fold_non_dependent_expr (tree expr)
5181 return fold_non_dependent_expr_sfinae (expr, tf_error);
5184 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
5185 must be a function or a pointer-to-function type, as specified
5186 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
5187 and check that the resulting function has external linkage. */
5190 convert_nontype_argument_function (tree type, tree expr)
5195 fn = instantiate_type (type, fns, tf_none);
5196 if (fn == error_mark_node)
5197 return error_mark_node;
5200 if (TREE_CODE (fn_no_ptr) == ADDR_EXPR)
5201 fn_no_ptr = TREE_OPERAND (fn_no_ptr, 0);
5202 if (TREE_CODE (fn_no_ptr) == BASELINK)
5203 fn_no_ptr = BASELINK_FUNCTIONS (fn_no_ptr);
5205 /* [temp.arg.nontype]/1
5207 A template-argument for a non-type, non-template template-parameter
5210 -- the address of an object or function with external linkage. */
5211 if (!DECL_EXTERNAL_LINKAGE_P (fn_no_ptr))
5213 error ("%qE is not a valid template argument for type %qT "
5214 "because function %qD has not external linkage",
5215 expr, type, fn_no_ptr);
5222 /* Subroutine of convert_nontype_argument.
5223 Check if EXPR of type TYPE is a valid pointer-to-member constant.
5224 Emit an error otherwise. */
5227 check_valid_ptrmem_cst_expr (tree type, tree expr,
5228 tsubst_flags_t complain)
5231 if (expr && (null_ptr_cst_p (expr) || TREE_CODE (expr) == PTRMEM_CST))
5233 if (complain & tf_error)
5235 error ("%qE is not a valid template argument for type %qT",
5237 error ("it must be a pointer-to-member of the form %<&X::Y%>");
5242 /* Returns TRUE iff the address of OP is value-dependent.
5244 14.6.2.4 [temp.dep.temp]:
5245 A non-integral non-type template-argument is dependent if its type is
5246 dependent or it has either of the following forms
5249 and contains a nested-name-specifier which specifies a class-name that
5250 names a dependent type.
5252 We generalize this to just say that the address of a member of a
5253 dependent class is value-dependent; the above doesn't cover the
5254 address of a static data member named with an unqualified-id. */
5257 has_value_dependent_address (tree op)
5259 /* We could use get_inner_reference here, but there's no need;
5260 this is only relevant for template non-type arguments, which
5261 can only be expressed as &id-expression. */
5264 tree ctx = CP_DECL_CONTEXT (op);
5265 if (TYPE_P (ctx) && dependent_type_p (ctx))
5272 /* Attempt to convert the non-type template parameter EXPR to the
5273 indicated TYPE. If the conversion is successful, return the
5274 converted value. If the conversion is unsuccessful, return
5275 NULL_TREE if we issued an error message, or error_mark_node if we
5276 did not. We issue error messages for out-and-out bad template
5277 parameters, but not simply because the conversion failed, since we
5278 might be just trying to do argument deduction. Both TYPE and EXPR
5279 must be non-dependent.
5281 The conversion follows the special rules described in
5282 [temp.arg.nontype], and it is much more strict than an implicit
5285 This function is called twice for each template argument (see
5286 lookup_template_class for a more accurate description of this
5287 problem). This means that we need to handle expressions which
5288 are not valid in a C++ source, but can be created from the
5289 first call (for instance, casts to perform conversions). These
5290 hacks can go away after we fix the double coercion problem. */
5293 convert_nontype_argument (tree type, tree expr, tsubst_flags_t complain)
5297 /* Detect immediately string literals as invalid non-type argument.
5298 This special-case is not needed for correctness (we would easily
5299 catch this later), but only to provide better diagnostic for this
5300 common user mistake. As suggested by DR 100, we do not mention
5301 linkage issues in the diagnostic as this is not the point. */
5302 /* FIXME we're making this OK. */
5303 if (TREE_CODE (expr) == STRING_CST)
5305 if (complain & tf_error)
5306 error ("%qE is not a valid template argument for type %qT "
5307 "because string literals can never be used in this context",
5312 /* Add the ADDR_EXPR now for the benefit of
5313 value_dependent_expression_p. */
5314 if (TYPE_PTROBV_P (type))
5315 expr = decay_conversion (expr);
5317 /* If we are in a template, EXPR may be non-dependent, but still
5318 have a syntactic, rather than semantic, form. For example, EXPR
5319 might be a SCOPE_REF, rather than the VAR_DECL to which the
5320 SCOPE_REF refers. Preserving the qualifying scope is necessary
5321 so that access checking can be performed when the template is
5322 instantiated -- but here we need the resolved form so that we can
5323 convert the argument. */
5324 if (TYPE_REF_OBJ_P (type)
5325 && has_value_dependent_address (expr))
5326 /* If we want the address and it's value-dependent, don't fold. */;
5327 else if (!type_unknown_p (expr))
5328 expr = fold_non_dependent_expr_sfinae (expr, complain);
5329 if (error_operand_p (expr))
5330 return error_mark_node;
5331 expr_type = TREE_TYPE (expr);
5332 if (TREE_CODE (type) == REFERENCE_TYPE)
5333 expr = mark_lvalue_use (expr);
5335 expr = mark_rvalue_use (expr);
5337 /* HACK: Due to double coercion, we can get a
5338 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
5339 which is the tree that we built on the first call (see
5340 below when coercing to reference to object or to reference to
5341 function). We just strip everything and get to the arg.
5342 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
5344 if (TREE_CODE (expr) == NOP_EXPR)
5346 if (TYPE_REF_OBJ_P (type) || TYPE_REFFN_P (type))
5348 /* ??? Maybe we could use convert_from_reference here, but we
5349 would need to relax its constraints because the NOP_EXPR
5350 could actually change the type to something more cv-qualified,
5351 and this is not folded by convert_from_reference. */
5352 tree addr = TREE_OPERAND (expr, 0);
5353 gcc_assert (TREE_CODE (expr_type) == REFERENCE_TYPE);
5354 gcc_assert (TREE_CODE (addr) == ADDR_EXPR);
5355 gcc_assert (TREE_CODE (TREE_TYPE (addr)) == POINTER_TYPE);
5356 gcc_assert (same_type_ignoring_top_level_qualifiers_p
5357 (TREE_TYPE (expr_type),
5358 TREE_TYPE (TREE_TYPE (addr))));
5360 expr = TREE_OPERAND (addr, 0);
5361 expr_type = TREE_TYPE (expr);
5364 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
5365 parameter is a pointer to object, through decay and
5366 qualification conversion. Let's strip everything. */
5367 else if (TYPE_PTROBV_P (type))
5370 gcc_assert (TREE_CODE (expr) == ADDR_EXPR);
5371 gcc_assert (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE);
5372 /* Skip the ADDR_EXPR only if it is part of the decay for
5373 an array. Otherwise, it is part of the original argument
5374 in the source code. */
5375 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == ARRAY_TYPE)
5376 expr = TREE_OPERAND (expr, 0);
5377 expr_type = TREE_TYPE (expr);
5381 /* [temp.arg.nontype]/5, bullet 1
5383 For a non-type template-parameter of integral or enumeration type,
5384 integral promotions (_conv.prom_) and integral conversions
5385 (_conv.integral_) are applied. */
5386 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
5388 tree t = build_integral_nontype_arg_conv (type, expr, complain);
5389 t = maybe_constant_value (t);
5390 if (t != error_mark_node)
5393 if (!same_type_ignoring_top_level_qualifiers_p (type, TREE_TYPE (expr)))
5394 return error_mark_node;
5396 /* Notice that there are constant expressions like '4 % 0' which
5397 do not fold into integer constants. */
5398 if (TREE_CODE (expr) != INTEGER_CST)
5400 if (complain & tf_error)
5402 error ("%qE is not a valid template argument for type %qT "
5403 "because it is a non-constant expression", expr, type);
5404 cxx_constant_value (expr);
5409 /* [temp.arg.nontype]/5, bullet 2
5411 For a non-type template-parameter of type pointer to object,
5412 qualification conversions (_conv.qual_) and the array-to-pointer
5413 conversion (_conv.array_) are applied. */
5414 else if (TYPE_PTROBV_P (type))
5416 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5418 A template-argument for a non-type, non-template template-parameter
5419 shall be one of: [...]
5421 -- the name of a non-type template-parameter;
5422 -- the address of an object or function with external linkage, [...]
5423 expressed as "& id-expression" where the & is optional if the name
5424 refers to a function or array, or if the corresponding
5425 template-parameter is a reference.
5427 Here, we do not care about functions, as they are invalid anyway
5428 for a parameter of type pointer-to-object. */
5430 if (DECL_P (expr) && DECL_TEMPLATE_PARM_P (expr))
5431 /* Non-type template parameters are OK. */
5433 else if (TREE_CODE (expr) != ADDR_EXPR
5434 && TREE_CODE (expr_type) != ARRAY_TYPE)
5436 if (TREE_CODE (expr) == VAR_DECL)
5438 error ("%qD is not a valid template argument "
5439 "because %qD is a variable, not the address of "
5444 /* Other values, like integer constants, might be valid
5445 non-type arguments of some other type. */
5446 return error_mark_node;
5452 decl = ((TREE_CODE (expr) == ADDR_EXPR)
5453 ? TREE_OPERAND (expr, 0) : expr);
5454 if (TREE_CODE (decl) != VAR_DECL)
5456 error ("%qE is not a valid template argument of type %qT "
5457 "because %qE is not a variable",
5461 else if (!DECL_EXTERNAL_LINKAGE_P (decl))
5463 error ("%qE is not a valid template argument of type %qT "
5464 "because %qD does not have external linkage",
5470 expr = decay_conversion (expr);
5471 if (expr == error_mark_node)
5472 return error_mark_node;
5474 expr = perform_qualification_conversions (type, expr);
5475 if (expr == error_mark_node)
5476 return error_mark_node;
5478 /* [temp.arg.nontype]/5, bullet 3
5480 For a non-type template-parameter of type reference to object, no
5481 conversions apply. The type referred to by the reference may be more
5482 cv-qualified than the (otherwise identical) type of the
5483 template-argument. The template-parameter is bound directly to the
5484 template-argument, which must be an lvalue. */
5485 else if (TYPE_REF_OBJ_P (type))
5487 if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type),
5489 return error_mark_node;
5491 if (!at_least_as_qualified_p (TREE_TYPE (type), expr_type))
5493 error ("%qE is not a valid template argument for type %qT "
5494 "because of conflicts in cv-qualification", expr, type);
5498 if (!real_lvalue_p (expr))
5500 error ("%qE is not a valid template argument for type %qT "
5501 "because it is not an lvalue", expr, type);
5505 /* [temp.arg.nontype]/1
5507 A template-argument for a non-type, non-template template-parameter
5508 shall be one of: [...]
5510 -- the address of an object or function with external linkage. */
5511 if (TREE_CODE (expr) == INDIRECT_REF
5512 && TYPE_REF_OBJ_P (TREE_TYPE (TREE_OPERAND (expr, 0))))
5514 expr = TREE_OPERAND (expr, 0);
5517 error ("%q#D is not a valid template argument for type %qT "
5518 "because a reference variable does not have a constant "
5519 "address", expr, type);
5526 error ("%qE is not a valid template argument for type %qT "
5527 "because it is not an object with external linkage",
5532 if (!DECL_EXTERNAL_LINKAGE_P (expr))
5534 error ("%qE is not a valid template argument for type %qT "
5535 "because object %qD has not external linkage",
5540 expr = build_nop (type, build_address (expr));
5542 /* [temp.arg.nontype]/5, bullet 4
5544 For a non-type template-parameter of type pointer to function, only
5545 the function-to-pointer conversion (_conv.func_) is applied. If the
5546 template-argument represents a set of overloaded functions (or a
5547 pointer to such), the matching function is selected from the set
5549 else if (TYPE_PTRFN_P (type))
5551 /* If the argument is a template-id, we might not have enough
5552 context information to decay the pointer. */
5553 if (!type_unknown_p (expr_type))
5555 expr = decay_conversion (expr);
5556 if (expr == error_mark_node)
5557 return error_mark_node;
5560 expr = convert_nontype_argument_function (type, expr);
5561 if (!expr || expr == error_mark_node)
5564 if (TREE_CODE (expr) != ADDR_EXPR)
5566 error ("%qE is not a valid template argument for type %qT", expr, type);
5567 error ("it must be the address of a function with external linkage");
5571 /* [temp.arg.nontype]/5, bullet 5
5573 For a non-type template-parameter of type reference to function, no
5574 conversions apply. If the template-argument represents a set of
5575 overloaded functions, the matching function is selected from the set
5577 else if (TYPE_REFFN_P (type))
5579 if (TREE_CODE (expr) == ADDR_EXPR)
5581 error ("%qE is not a valid template argument for type %qT "
5582 "because it is a pointer", expr, type);
5583 inform (input_location, "try using %qE instead", TREE_OPERAND (expr, 0));
5587 expr = convert_nontype_argument_function (TREE_TYPE (type), expr);
5588 if (!expr || expr == error_mark_node)
5591 expr = build_nop (type, build_address (expr));
5593 /* [temp.arg.nontype]/5, bullet 6
5595 For a non-type template-parameter of type pointer to member function,
5596 no conversions apply. If the template-argument represents a set of
5597 overloaded member functions, the matching member function is selected
5598 from the set (_over.over_). */
5599 else if (TYPE_PTRMEMFUNC_P (type))
5601 expr = instantiate_type (type, expr, tf_none);
5602 if (expr == error_mark_node)
5603 return error_mark_node;
5605 /* [temp.arg.nontype] bullet 1 says the pointer to member
5606 expression must be a pointer-to-member constant. */
5607 if (!check_valid_ptrmem_cst_expr (type, expr, complain))
5608 return error_mark_node;
5610 /* There is no way to disable standard conversions in
5611 resolve_address_of_overloaded_function (called by
5612 instantiate_type). It is possible that the call succeeded by
5613 converting &B::I to &D::I (where B is a base of D), so we need
5614 to reject this conversion here.
5616 Actually, even if there was a way to disable standard conversions,
5617 it would still be better to reject them here so that we can
5618 provide a superior diagnostic. */
5619 if (!same_type_p (TREE_TYPE (expr), type))
5621 error ("%qE is not a valid template argument for type %qT "
5622 "because it is of type %qT", expr, type,
5624 /* If we are just one standard conversion off, explain. */
5625 if (can_convert (type, TREE_TYPE (expr)))
5626 inform (input_location,
5627 "standard conversions are not allowed in this context");
5631 /* [temp.arg.nontype]/5, bullet 7
5633 For a non-type template-parameter of type pointer to data member,
5634 qualification conversions (_conv.qual_) are applied. */
5635 else if (TYPE_PTRMEM_P (type))
5637 /* [temp.arg.nontype] bullet 1 says the pointer to member
5638 expression must be a pointer-to-member constant. */
5639 if (!check_valid_ptrmem_cst_expr (type, expr, complain))
5640 return error_mark_node;
5642 expr = perform_qualification_conversions (type, expr);
5643 if (expr == error_mark_node)
5646 /* A template non-type parameter must be one of the above. */
5650 /* Sanity check: did we actually convert the argument to the
5652 gcc_assert (same_type_ignoring_top_level_qualifiers_p
5653 (type, TREE_TYPE (expr)));
5657 /* Subroutine of coerce_template_template_parms, which returns 1 if
5658 PARM_PARM and ARG_PARM match using the rule for the template
5659 parameters of template template parameters. Both PARM and ARG are
5660 template parameters; the rest of the arguments are the same as for
5661 coerce_template_template_parms.
5664 coerce_template_template_parm (tree parm,
5666 tsubst_flags_t complain,
5670 if (arg == NULL_TREE || arg == error_mark_node
5671 || parm == NULL_TREE || parm == error_mark_node)
5674 if (TREE_CODE (arg) != TREE_CODE (parm))
5677 switch (TREE_CODE (parm))
5680 /* We encounter instantiations of templates like
5681 template <template <template <class> class> class TT>
5684 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
5685 tree argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
5687 if (!coerce_template_template_parms
5688 (parmparm, argparm, complain, in_decl, outer_args))
5694 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (arg))
5695 && !TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
5696 /* Argument is a parameter pack but parameter is not. */
5701 /* The tsubst call is used to handle cases such as
5703 template <int> class C {};
5704 template <class T, template <T> class TT> class D {};
5707 i.e. the parameter list of TT depends on earlier parameters. */
5708 if (!uses_template_parms (TREE_TYPE (arg))
5710 (tsubst (TREE_TYPE (parm), outer_args, complain, in_decl),
5714 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (arg))
5715 && !TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
5716 /* Argument is a parameter pack but parameter is not. */
5729 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
5730 template template parameters. Both PARM_PARMS and ARG_PARMS are
5731 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
5734 Consider the example:
5735 template <class T> class A;
5736 template<template <class U> class TT> class B;
5738 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
5739 the parameters to A, and OUTER_ARGS contains A. */
5742 coerce_template_template_parms (tree parm_parms,
5744 tsubst_flags_t complain,
5748 int nparms, nargs, i;
5752 gcc_assert (TREE_CODE (parm_parms) == TREE_VEC);
5753 gcc_assert (TREE_CODE (arg_parms) == TREE_VEC);
5755 nparms = TREE_VEC_LENGTH (parm_parms);
5756 nargs = TREE_VEC_LENGTH (arg_parms);
5758 /* Determine whether we have a parameter pack at the end of the
5759 template template parameter's template parameter list. */
5760 if (TREE_VEC_ELT (parm_parms, nparms - 1) != error_mark_node)
5762 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, nparms - 1));
5764 if (parm == error_mark_node)
5767 switch (TREE_CODE (parm))
5771 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
5776 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
5786 && !(variadic_p && nargs >= nparms - 1))
5789 /* Check all of the template parameters except the parameter pack at
5790 the end (if any). */
5791 for (i = 0; i < nparms - variadic_p; ++i)
5793 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node
5794 || TREE_VEC_ELT (arg_parms, i) == error_mark_node)
5797 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
5798 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
5800 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
5808 /* Check each of the template parameters in the template
5809 argument against the template parameter pack at the end of
5810 the template template parameter. */
5811 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node)
5814 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
5816 for (; i < nargs; ++i)
5818 if (TREE_VEC_ELT (arg_parms, i) == error_mark_node)
5821 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
5823 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
5832 /* Verifies that the deduced template arguments (in TARGS) for the
5833 template template parameters (in TPARMS) represent valid bindings,
5834 by comparing the template parameter list of each template argument
5835 to the template parameter list of its corresponding template
5836 template parameter, in accordance with DR150. This
5837 routine can only be called after all template arguments have been
5838 deduced. It will return TRUE if all of the template template
5839 parameter bindings are okay, FALSE otherwise. */
5841 template_template_parm_bindings_ok_p (tree tparms, tree targs)
5843 int i, ntparms = TREE_VEC_LENGTH (tparms);
5846 /* We're dealing with template parms in this process. */
5847 ++processing_template_decl;
5849 targs = INNERMOST_TEMPLATE_ARGS (targs);
5851 for (i = 0; i < ntparms; ++i)
5853 tree tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
5854 tree targ = TREE_VEC_ELT (targs, i);
5856 if (TREE_CODE (tparm) == TEMPLATE_DECL && targ)
5858 tree packed_args = NULL_TREE;
5861 if (ARGUMENT_PACK_P (targ))
5863 /* Look inside the argument pack. */
5864 packed_args = ARGUMENT_PACK_ARGS (targ);
5865 len = TREE_VEC_LENGTH (packed_args);
5868 for (idx = 0; idx < len; ++idx)
5870 tree targ_parms = NULL_TREE;
5873 /* Extract the next argument from the argument
5875 targ = TREE_VEC_ELT (packed_args, idx);
5877 if (PACK_EXPANSION_P (targ))
5878 /* Look at the pattern of the pack expansion. */
5879 targ = PACK_EXPANSION_PATTERN (targ);
5881 /* Extract the template parameters from the template
5883 if (TREE_CODE (targ) == TEMPLATE_DECL)
5884 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (targ);
5885 else if (TREE_CODE (targ) == TEMPLATE_TEMPLATE_PARM)
5886 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (TYPE_NAME (targ));
5888 /* Verify that we can coerce the template template
5889 parameters from the template argument to the template
5890 parameter. This requires an exact match. */
5892 && !coerce_template_template_parms
5893 (DECL_INNERMOST_TEMPLATE_PARMS (tparm),
5908 --processing_template_decl;
5912 /* Convert the indicated template ARG as necessary to match the
5913 indicated template PARM. Returns the converted ARG, or
5914 error_mark_node if the conversion was unsuccessful. Error and
5915 warning messages are issued under control of COMPLAIN. This
5916 conversion is for the Ith parameter in the parameter list. ARGS is
5917 the full set of template arguments deduced so far. */
5920 convert_template_argument (tree parm,
5923 tsubst_flags_t complain,
5929 int is_type, requires_type, is_tmpl_type, requires_tmpl_type;
5931 if (TREE_CODE (arg) == TREE_LIST
5932 && TREE_CODE (TREE_VALUE (arg)) == OFFSET_REF)
5934 /* The template argument was the name of some
5935 member function. That's usually
5936 invalid, but static members are OK. In any
5937 case, grab the underlying fields/functions
5938 and issue an error later if required. */
5939 orig_arg = TREE_VALUE (arg);
5940 TREE_TYPE (arg) = unknown_type_node;
5945 requires_tmpl_type = TREE_CODE (parm) == TEMPLATE_DECL;
5946 requires_type = (TREE_CODE (parm) == TYPE_DECL
5947 || requires_tmpl_type);
5949 /* When determining whether an argument pack expansion is a template,
5950 look at the pattern. */
5951 if (TREE_CODE (arg) == TYPE_PACK_EXPANSION)
5952 arg = PACK_EXPANSION_PATTERN (arg);
5954 /* Deal with an injected-class-name used as a template template arg. */
5955 if (requires_tmpl_type && CLASS_TYPE_P (arg))
5957 tree t = maybe_get_template_decl_from_type_decl (TYPE_NAME (arg));
5958 if (TREE_CODE (t) == TEMPLATE_DECL)
5960 if (complain & tf_warning_or_error)
5961 pedwarn (input_location, OPT_pedantic, "injected-class-name %qD"
5962 " used as template template argument", TYPE_NAME (arg));
5963 else if (flag_pedantic_errors)
5971 ((TREE_CODE (arg) == TEMPLATE_DECL
5972 && TREE_CODE (DECL_TEMPLATE_RESULT (arg)) == TYPE_DECL)
5973 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
5974 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE);
5977 && (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
5978 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE))
5979 arg = TYPE_STUB_DECL (arg);
5981 is_type = TYPE_P (arg) || is_tmpl_type;
5983 if (requires_type && ! is_type && TREE_CODE (arg) == SCOPE_REF
5984 && TREE_CODE (TREE_OPERAND (arg, 0)) == TEMPLATE_TYPE_PARM)
5986 permerror (input_location, "to refer to a type member of a template parameter, "
5987 "use %<typename %E%>", orig_arg);
5989 orig_arg = make_typename_type (TREE_OPERAND (arg, 0),
5990 TREE_OPERAND (arg, 1),
5992 complain & tf_error);
5996 if (is_type != requires_type)
6000 if (complain & tf_error)
6002 error ("type/value mismatch at argument %d in template "
6003 "parameter list for %qD",
6006 error (" expected a constant of type %qT, got %qT",
6008 (DECL_P (arg) ? DECL_NAME (arg) : orig_arg));
6009 else if (requires_tmpl_type)
6010 error (" expected a class template, got %qE", orig_arg);
6012 error (" expected a type, got %qE", orig_arg);
6015 return error_mark_node;
6017 if (is_tmpl_type ^ requires_tmpl_type)
6019 if (in_decl && (complain & tf_error))
6021 error ("type/value mismatch at argument %d in template "
6022 "parameter list for %qD",
6025 error (" expected a type, got %qT", DECL_NAME (arg));
6027 error (" expected a class template, got %qT", orig_arg);
6029 return error_mark_node;
6034 if (requires_tmpl_type)
6036 if (TREE_CODE (TREE_TYPE (arg)) == UNBOUND_CLASS_TEMPLATE)
6037 /* The number of argument required is not known yet.
6038 Just accept it for now. */
6039 val = TREE_TYPE (arg);
6042 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
6045 argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
6047 if (coerce_template_template_parms (parmparm, argparm,
6053 /* TEMPLATE_TEMPLATE_PARM node is preferred over
6055 if (val != error_mark_node)
6057 if (DECL_TEMPLATE_TEMPLATE_PARM_P (val))
6058 val = TREE_TYPE (val);
6059 if (TREE_CODE (orig_arg) == TYPE_PACK_EXPANSION)
6060 val = make_pack_expansion (val);
6065 if (in_decl && (complain & tf_error))
6067 error ("type/value mismatch at argument %d in "
6068 "template parameter list for %qD",
6070 error (" expected a template of type %qD, got %qT",
6074 val = error_mark_node;
6080 /* We only form one instance of each template specialization.
6081 Therefore, if we use a non-canonical variant (i.e., a
6082 typedef), any future messages referring to the type will use
6083 the typedef, which is confusing if those future uses do not
6084 themselves also use the typedef. */
6086 val = strip_typedefs (val);
6090 tree t = tsubst (TREE_TYPE (parm), args, complain, in_decl);
6092 if (invalid_nontype_parm_type_p (t, complain))
6093 return error_mark_node;
6095 if (template_parameter_pack_p (parm) && ARGUMENT_PACK_P (orig_arg))
6097 if (same_type_p (t, TREE_TYPE (orig_arg)))
6101 /* Not sure if this is reachable, but it doesn't hurt
6103 error ("type mismatch in nontype parameter pack");
6104 val = error_mark_node;
6107 else if (!uses_template_parms (orig_arg) && !uses_template_parms (t))
6108 /* We used to call digest_init here. However, digest_init
6109 will report errors, which we don't want when complain
6110 is zero. More importantly, digest_init will try too
6111 hard to convert things: for example, `0' should not be
6112 converted to pointer type at this point according to
6113 the standard. Accepting this is not merely an
6114 extension, since deciding whether or not these
6115 conversions can occur is part of determining which
6116 function template to call, or whether a given explicit
6117 argument specification is valid. */
6118 val = convert_nontype_argument (t, orig_arg, complain);
6122 if (val == NULL_TREE)
6123 val = error_mark_node;
6124 else if (val == error_mark_node && (complain & tf_error))
6125 error ("could not convert template argument %qE to %qT", orig_arg, t);
6127 if (TREE_CODE (val) == SCOPE_REF)
6129 /* Strip typedefs from the SCOPE_REF. */
6130 tree type = strip_typedefs (TREE_TYPE (val));
6131 tree scope = strip_typedefs (TREE_OPERAND (val, 0));
6132 val = build_qualified_name (type, scope, TREE_OPERAND (val, 1),
6133 QUALIFIED_NAME_IS_TEMPLATE (val));
6140 /* Coerces the remaining template arguments in INNER_ARGS (from
6141 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
6142 Returns the coerced argument pack. PARM_IDX is the position of this
6143 parameter in the template parameter list. ARGS is the original
6144 template argument list. */
6146 coerce_template_parameter_pack (tree parms,
6154 tsubst_flags_t complain)
6156 tree parm = TREE_VEC_ELT (parms, parm_idx);
6157 int nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
6160 tree packed_types = NULL_TREE;
6162 if (arg_idx > nargs)
6165 packed_args = make_tree_vec (nargs - arg_idx);
6167 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL
6168 && uses_parameter_packs (TREE_TYPE (TREE_VALUE (parm))))
6170 /* When the template parameter is a non-type template
6171 parameter pack whose type uses parameter packs, we need
6172 to look at each of the template arguments
6173 separately. Build a vector of the types for these
6174 non-type template parameters in PACKED_TYPES. */
6176 = make_pack_expansion (TREE_TYPE (TREE_VALUE (parm)));
6177 packed_types = tsubst_pack_expansion (expansion, args,
6180 if (packed_types == error_mark_node)
6181 return error_mark_node;
6183 /* Check that we have the right number of arguments. */
6185 && !PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx))
6186 && nargs - arg_idx != TREE_VEC_LENGTH (packed_types))
6189 = TREE_VEC_LENGTH (parms) - 1 + TREE_VEC_LENGTH (packed_types);
6190 error ("wrong number of template arguments (%d, should be %d)",
6191 nargs, needed_parms);
6192 return error_mark_node;
6195 /* If we aren't able to check the actual arguments now
6196 (because they haven't been expanded yet), we can at least
6197 verify that all of the types used for the non-type
6198 template parameter pack are, in fact, valid for non-type
6199 template parameters. */
6201 && PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx)))
6203 int j, len = TREE_VEC_LENGTH (packed_types);
6204 for (j = 0; j < len; ++j)
6206 tree t = TREE_VEC_ELT (packed_types, j);
6207 if (invalid_nontype_parm_type_p (t, complain))
6208 return error_mark_node;
6213 /* Convert the remaining arguments, which will be a part of the
6214 parameter pack "parm". */
6215 for (; arg_idx < nargs; ++arg_idx)
6217 tree arg = TREE_VEC_ELT (inner_args, arg_idx);
6218 tree actual_parm = TREE_VALUE (parm);
6220 if (packed_types && !PACK_EXPANSION_P (arg))
6222 /* When we have a vector of types (corresponding to the
6223 non-type template parameter pack that uses parameter
6224 packs in its type, as mention above), and the
6225 argument is not an expansion (which expands to a
6226 currently unknown number of arguments), clone the
6227 parm and give it the next type in PACKED_TYPES. */
6228 actual_parm = copy_node (actual_parm);
6229 TREE_TYPE (actual_parm) =
6230 TREE_VEC_ELT (packed_types, arg_idx - parm_idx);
6233 if (arg != error_mark_node)
6234 arg = convert_template_argument (actual_parm,
6235 arg, new_args, complain, parm_idx,
6237 if (arg == error_mark_node)
6239 TREE_VEC_ELT (packed_args, arg_idx - parm_idx) = arg;
6242 if (TREE_CODE (TREE_VALUE (parm)) == TYPE_DECL
6243 || TREE_CODE (TREE_VALUE (parm)) == TEMPLATE_DECL)
6244 argument_pack = cxx_make_type (TYPE_ARGUMENT_PACK);
6247 argument_pack = make_node (NONTYPE_ARGUMENT_PACK);
6248 TREE_TYPE (argument_pack)
6249 = tsubst (TREE_TYPE (TREE_VALUE (parm)), new_args, complain, in_decl);
6250 TREE_CONSTANT (argument_pack) = 1;
6253 SET_ARGUMENT_PACK_ARGS (argument_pack, packed_args);
6254 #ifdef ENABLE_CHECKING
6255 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (packed_args,
6256 TREE_VEC_LENGTH (packed_args));
6258 return argument_pack;
6261 /* Convert all template arguments to their appropriate types, and
6262 return a vector containing the innermost resulting template
6263 arguments. If any error occurs, return error_mark_node. Error and
6264 warning messages are issued under control of COMPLAIN.
6266 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
6267 for arguments not specified in ARGS. Otherwise, if
6268 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
6269 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
6270 USE_DEFAULT_ARGS is false, then all arguments must be specified in
6274 coerce_template_parms (tree parms,
6277 tsubst_flags_t complain,
6278 bool require_all_args,
6279 bool use_default_args)
6281 int nparms, nargs, parm_idx, arg_idx, lost = 0;
6284 tree new_inner_args;
6285 int saved_unevaluated_operand;
6286 int saved_inhibit_evaluation_warnings;
6288 /* When used as a boolean value, indicates whether this is a
6289 variadic template parameter list. Since it's an int, we can also
6290 subtract it from nparms to get the number of non-variadic
6294 if (args == error_mark_node)
6295 return error_mark_node;
6297 nparms = TREE_VEC_LENGTH (parms);
6299 /* Determine if there are any parameter packs. */
6300 for (parm_idx = 0; parm_idx < nparms; ++parm_idx)
6302 tree tparm = TREE_VALUE (TREE_VEC_ELT (parms, parm_idx));
6303 if (template_parameter_pack_p (tparm))
6307 inner_args = INNERMOST_TEMPLATE_ARGS (args);
6308 /* If there are 0 or 1 parameter packs, we need to expand any argument
6309 packs so that we can deduce a parameter pack from some non-packed args
6310 followed by an argument pack, as in variadic85.C. If there are more
6311 than that, we need to leave argument packs intact so the arguments are
6312 assigned to the right parameter packs. This should only happen when
6313 dealing with a nested class inside a partial specialization of a class
6314 template, as in variadic92.C. */
6315 if (variadic_p <= 1)
6316 inner_args = expand_template_argument_pack (inner_args);
6318 nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
6319 if ((nargs > nparms && !variadic_p)
6320 || (nargs < nparms - variadic_p
6322 && (!use_default_args
6323 || (TREE_VEC_ELT (parms, nargs) != error_mark_node
6324 && !TREE_PURPOSE (TREE_VEC_ELT (parms, nargs))))))
6326 if (complain & tf_error)
6331 error ("wrong number of template arguments "
6332 "(%d, should be %d or more)", nargs, nparms);
6335 error ("wrong number of template arguments "
6336 "(%d, should be %d)", nargs, nparms);
6339 error ("provided for %q+D", in_decl);
6342 return error_mark_node;
6345 /* We need to evaluate the template arguments, even though this
6346 template-id may be nested within a "sizeof". */
6347 saved_unevaluated_operand = cp_unevaluated_operand;
6348 cp_unevaluated_operand = 0;
6349 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
6350 c_inhibit_evaluation_warnings = 0;
6351 new_inner_args = make_tree_vec (nparms);
6352 new_args = add_outermost_template_args (args, new_inner_args);
6353 for (parm_idx = 0, arg_idx = 0; parm_idx < nparms; parm_idx++, arg_idx++)
6358 /* Get the Ith template parameter. */
6359 parm = TREE_VEC_ELT (parms, parm_idx);
6361 if (parm == error_mark_node)
6363 TREE_VEC_ELT (new_inner_args, arg_idx) = error_mark_node;
6367 /* Calculate the next argument. */
6368 if (arg_idx < nargs)
6369 arg = TREE_VEC_ELT (inner_args, arg_idx);
6373 if (template_parameter_pack_p (TREE_VALUE (parm))
6374 && !(arg && ARGUMENT_PACK_P (arg)))
6376 /* All remaining arguments will be placed in the
6377 template parameter pack PARM. */
6378 arg = coerce_template_parameter_pack (parms, parm_idx, args,
6379 inner_args, arg_idx,
6383 /* Store this argument. */
6384 if (arg == error_mark_node)
6386 TREE_VEC_ELT (new_inner_args, parm_idx) = arg;
6388 /* We are done with all of the arguments. */
6395 if (PACK_EXPANSION_P (arg))
6397 if (complain & tf_error)
6399 /* FIXME this restriction was removed by N2555; see
6401 /* If ARG is a pack expansion, but PARM is not a
6402 template parameter pack (if it were, we would have
6403 handled it above), we're trying to expand into a
6404 fixed-length argument list. */
6405 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
6406 sorry ("cannot expand %<%E%> into a fixed-length "
6407 "argument list", arg);
6409 sorry ("cannot expand %<%T%> into a fixed-length "
6410 "argument list", arg);
6415 else if (require_all_args)
6417 /* There must be a default arg in this case. */
6418 arg = tsubst_template_arg (TREE_PURPOSE (parm), new_args,
6420 /* The position of the first default template argument,
6421 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6423 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args))
6424 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args, arg_idx);
6429 if (arg == error_mark_node)
6431 if (complain & tf_error)
6432 error ("template argument %d is invalid", arg_idx + 1);
6435 /* This only occurs if there was an error in the template
6436 parameter list itself (which we would already have
6437 reported) that we are trying to recover from, e.g., a class
6438 template with a parameter list such as
6439 template<typename..., typename>. */
6442 arg = convert_template_argument (TREE_VALUE (parm),
6443 arg, new_args, complain,
6446 if (arg == error_mark_node)
6448 TREE_VEC_ELT (new_inner_args, arg_idx) = arg;
6450 cp_unevaluated_operand = saved_unevaluated_operand;
6451 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
6454 return error_mark_node;
6456 #ifdef ENABLE_CHECKING
6457 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args))
6458 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args,
6459 TREE_VEC_LENGTH (new_inner_args));
6462 return new_inner_args;
6465 /* Returns 1 if template args OT and NT are equivalent. */
6468 template_args_equal (tree ot, tree nt)
6473 if (TREE_CODE (nt) == TREE_VEC)
6474 /* For member templates */
6475 return TREE_CODE (ot) == TREE_VEC && comp_template_args (ot, nt);
6476 else if (PACK_EXPANSION_P (ot))
6477 return PACK_EXPANSION_P (nt)
6478 && template_args_equal (PACK_EXPANSION_PATTERN (ot),
6479 PACK_EXPANSION_PATTERN (nt));
6480 else if (ARGUMENT_PACK_P (ot))
6485 if (!ARGUMENT_PACK_P (nt))
6488 opack = ARGUMENT_PACK_ARGS (ot);
6489 npack = ARGUMENT_PACK_ARGS (nt);
6490 len = TREE_VEC_LENGTH (opack);
6491 if (TREE_VEC_LENGTH (npack) != len)
6493 for (i = 0; i < len; ++i)
6494 if (!template_args_equal (TREE_VEC_ELT (opack, i),
6495 TREE_VEC_ELT (npack, i)))
6499 else if (ot && TREE_CODE (ot) == ARGUMENT_PACK_SELECT)
6501 /* We get here probably because we are in the middle of substituting
6502 into the pattern of a pack expansion. In that case the
6503 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
6504 interested in. So we want to use the initial pack argument for
6506 ot = ARGUMENT_PACK_SELECT_FROM_PACK (ot);
6507 if (nt && TREE_CODE (nt) == ARGUMENT_PACK_SELECT)
6508 nt = ARGUMENT_PACK_SELECT_FROM_PACK (nt);
6509 return template_args_equal (ot, nt);
6511 else if (TYPE_P (nt))
6512 return TYPE_P (ot) && same_type_p (ot, nt);
6513 else if (TREE_CODE (ot) == TREE_VEC || TYPE_P (ot))
6516 return cp_tree_equal (ot, nt);
6519 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
6520 of template arguments. Returns 0 otherwise. */
6523 comp_template_args (tree oldargs, tree newargs)
6527 if (TREE_VEC_LENGTH (oldargs) != TREE_VEC_LENGTH (newargs))
6530 for (i = 0; i < TREE_VEC_LENGTH (oldargs); ++i)
6532 tree nt = TREE_VEC_ELT (newargs, i);
6533 tree ot = TREE_VEC_ELT (oldargs, i);
6535 if (! template_args_equal (ot, nt))
6542 add_pending_template (tree d)
6544 tree ti = (TYPE_P (d)
6545 ? CLASSTYPE_TEMPLATE_INFO (d)
6546 : DECL_TEMPLATE_INFO (d));
6547 struct pending_template *pt;
6550 if (TI_PENDING_TEMPLATE_FLAG (ti))
6553 /* We are called both from instantiate_decl, where we've already had a
6554 tinst_level pushed, and instantiate_template, where we haven't.
6556 level = !current_tinst_level || current_tinst_level->decl != d;
6559 push_tinst_level (d);
6561 pt = ggc_alloc_pending_template ();
6563 pt->tinst = current_tinst_level;
6564 if (last_pending_template)
6565 last_pending_template->next = pt;
6567 pending_templates = pt;
6569 last_pending_template = pt;
6571 TI_PENDING_TEMPLATE_FLAG (ti) = 1;
6578 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
6579 ARGLIST. Valid choices for FNS are given in the cp-tree.def
6580 documentation for TEMPLATE_ID_EXPR. */
6583 lookup_template_function (tree fns, tree arglist)
6587 if (fns == error_mark_node || arglist == error_mark_node)
6588 return error_mark_node;
6590 gcc_assert (!arglist || TREE_CODE (arglist) == TREE_VEC);
6591 gcc_assert (fns && (is_overloaded_fn (fns)
6592 || TREE_CODE (fns) == IDENTIFIER_NODE));
6594 if (BASELINK_P (fns))
6596 BASELINK_FUNCTIONS (fns) = build2 (TEMPLATE_ID_EXPR,
6598 BASELINK_FUNCTIONS (fns),
6603 type = TREE_TYPE (fns);
6604 if (TREE_CODE (fns) == OVERLOAD || !type)
6605 type = unknown_type_node;
6607 return build2 (TEMPLATE_ID_EXPR, type, fns, arglist);
6610 /* Within the scope of a template class S<T>, the name S gets bound
6611 (in build_self_reference) to a TYPE_DECL for the class, not a
6612 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
6613 or one of its enclosing classes, and that type is a template,
6614 return the associated TEMPLATE_DECL. Otherwise, the original
6617 Also handle the case when DECL is a TREE_LIST of ambiguous
6618 injected-class-names from different bases. */
6621 maybe_get_template_decl_from_type_decl (tree decl)
6623 if (decl == NULL_TREE)
6626 /* DR 176: A lookup that finds an injected-class-name (10.2
6627 [class.member.lookup]) can result in an ambiguity in certain cases
6628 (for example, if it is found in more than one base class). If all of
6629 the injected-class-names that are found refer to specializations of
6630 the same class template, and if the name is followed by a
6631 template-argument-list, the reference refers to the class template
6632 itself and not a specialization thereof, and is not ambiguous. */
6633 if (TREE_CODE (decl) == TREE_LIST)
6635 tree t, tmpl = NULL_TREE;
6636 for (t = decl; t; t = TREE_CHAIN (t))
6638 tree elt = maybe_get_template_decl_from_type_decl (TREE_VALUE (t));
6641 else if (tmpl != elt)
6644 if (tmpl && t == NULL_TREE)
6650 return (decl != NULL_TREE
6651 && DECL_SELF_REFERENCE_P (decl)
6652 && CLASSTYPE_TEMPLATE_INFO (TREE_TYPE (decl)))
6653 ? CLASSTYPE_TI_TEMPLATE (TREE_TYPE (decl)) : decl;
6656 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
6657 parameters, find the desired type.
6659 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
6661 IN_DECL, if non-NULL, is the template declaration we are trying to
6664 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
6665 the class we are looking up.
6667 Issue error and warning messages under control of COMPLAIN.
6669 If the template class is really a local class in a template
6670 function, then the FUNCTION_CONTEXT is the function in which it is
6673 ??? Note that this function is currently called *twice* for each
6674 template-id: the first time from the parser, while creating the
6675 incomplete type (finish_template_type), and the second type during the
6676 real instantiation (instantiate_template_class). This is surely something
6677 that we want to avoid. It also causes some problems with argument
6678 coercion (see convert_nontype_argument for more information on this). */
6681 lookup_template_class (tree d1,
6686 tsubst_flags_t complain)
6688 tree templ = NULL_TREE, parmlist;
6695 timevar_push (TV_NAME_LOOKUP);
6697 if (TREE_CODE (d1) == IDENTIFIER_NODE)
6699 tree value = innermost_non_namespace_value (d1);
6700 if (value && DECL_TEMPLATE_TEMPLATE_PARM_P (value))
6705 push_decl_namespace (context);
6706 templ = lookup_name (d1);
6707 templ = maybe_get_template_decl_from_type_decl (templ);
6709 pop_decl_namespace ();
6712 context = DECL_CONTEXT (templ);
6714 else if (TREE_CODE (d1) == TYPE_DECL && MAYBE_CLASS_TYPE_P (TREE_TYPE (d1)))
6716 tree type = TREE_TYPE (d1);
6718 /* If we are declaring a constructor, say A<T>::A<T>, we will get
6719 an implicit typename for the second A. Deal with it. */
6720 if (TREE_CODE (type) == TYPENAME_TYPE && TREE_TYPE (type))
6721 type = TREE_TYPE (type);
6723 if (CLASSTYPE_TEMPLATE_INFO (type))
6725 templ = CLASSTYPE_TI_TEMPLATE (type);
6726 d1 = DECL_NAME (templ);
6729 else if (TREE_CODE (d1) == ENUMERAL_TYPE
6730 || (TYPE_P (d1) && MAYBE_CLASS_TYPE_P (d1)))
6732 templ = TYPE_TI_TEMPLATE (d1);
6733 d1 = DECL_NAME (templ);
6735 else if (TREE_CODE (d1) == TEMPLATE_DECL
6736 && DECL_TEMPLATE_RESULT (d1)
6737 && TREE_CODE (DECL_TEMPLATE_RESULT (d1)) == TYPE_DECL)
6740 d1 = DECL_NAME (templ);
6741 context = DECL_CONTEXT (templ);
6744 /* Issue an error message if we didn't find a template. */
6747 if (complain & tf_error)
6748 error ("%qT is not a template", d1);
6749 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6752 if (TREE_CODE (templ) != TEMPLATE_DECL
6753 /* Make sure it's a user visible template, if it was named by
6755 || ((complain & tf_user) && !DECL_TEMPLATE_PARM_P (templ)
6756 && !PRIMARY_TEMPLATE_P (templ)))
6758 if (complain & tf_error)
6760 error ("non-template type %qT used as a template", d1);
6762 error ("for template declaration %q+D", in_decl);
6764 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6767 complain &= ~tf_user;
6769 if (DECL_TEMPLATE_TEMPLATE_PARM_P (templ))
6771 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
6772 template arguments */
6778 parmlist = DECL_INNERMOST_TEMPLATE_PARMS (templ);
6780 /* Consider an example where a template template parameter declared as
6782 template <class T, class U = std::allocator<T> > class TT
6784 The template parameter level of T and U are one level larger than
6785 of TT. To proper process the default argument of U, say when an
6786 instantiation `TT<int>' is seen, we need to build the full
6787 arguments containing {int} as the innermost level. Outer levels,
6788 available when not appearing as default template argument, can be
6789 obtained from the arguments of the enclosing template.
6791 Suppose that TT is later substituted with std::vector. The above
6792 instantiation is `TT<int, std::allocator<T> >' with TT at
6793 level 1, and T at level 2, while the template arguments at level 1
6794 becomes {std::vector} and the inner level 2 is {int}. */
6796 outer = DECL_CONTEXT (templ);
6798 outer = TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (outer)));
6799 else if (current_template_parms)
6800 /* This is an argument of the current template, so we haven't set
6801 DECL_CONTEXT yet. */
6802 outer = current_template_args ();
6805 arglist = add_to_template_args (outer, arglist);
6807 arglist2 = coerce_template_parms (parmlist, arglist, templ,
6809 /*require_all_args=*/true,
6810 /*use_default_args=*/true);
6811 if (arglist2 == error_mark_node
6812 || (!uses_template_parms (arglist2)
6813 && check_instantiated_args (templ, arglist2, complain)))
6814 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6816 parm = bind_template_template_parm (TREE_TYPE (templ), arglist2);
6817 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, parm);
6821 tree template_type = TREE_TYPE (templ);
6824 tree found = NULL_TREE;
6827 int is_dependent_type;
6828 int use_partial_inst_tmpl = false;
6830 gen_tmpl = most_general_template (templ);
6831 parmlist = DECL_TEMPLATE_PARMS (gen_tmpl);
6832 parm_depth = TMPL_PARMS_DEPTH (parmlist);
6833 arg_depth = TMPL_ARGS_DEPTH (arglist);
6835 if (arg_depth == 1 && parm_depth > 1)
6837 /* We've been given an incomplete set of template arguments.
6840 template <class T> struct S1 {
6841 template <class U> struct S2 {};
6842 template <class U> struct S2<U*> {};
6845 we will be called with an ARGLIST of `U*', but the
6846 TEMPLATE will be `template <class T> template
6847 <class U> struct S1<T>::S2'. We must fill in the missing
6850 = add_outermost_template_args (TYPE_TI_ARGS (TREE_TYPE (templ)),
6852 arg_depth = TMPL_ARGS_DEPTH (arglist);
6855 /* Now we should have enough arguments. */
6856 gcc_assert (parm_depth == arg_depth);
6858 /* From here on, we're only interested in the most general
6861 /* Calculate the BOUND_ARGS. These will be the args that are
6862 actually tsubst'd into the definition to create the
6866 /* We have multiple levels of arguments to coerce, at once. */
6868 int saved_depth = TMPL_ARGS_DEPTH (arglist);
6870 tree bound_args = make_tree_vec (parm_depth);
6872 for (i = saved_depth,
6873 t = DECL_TEMPLATE_PARMS (gen_tmpl);
6874 i > 0 && t != NULL_TREE;
6875 --i, t = TREE_CHAIN (t))
6878 if (i == saved_depth)
6879 a = coerce_template_parms (TREE_VALUE (t),
6882 /*require_all_args=*/true,
6883 /*use_default_args=*/true);
6885 /* Outer levels should have already been coerced. */
6886 a = TMPL_ARGS_LEVEL (arglist, i);
6888 /* Don't process further if one of the levels fails. */
6889 if (a == error_mark_node)
6891 /* Restore the ARGLIST to its full size. */
6892 TREE_VEC_LENGTH (arglist) = saved_depth;
6893 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6896 SET_TMPL_ARGS_LEVEL (bound_args, i, a);
6898 /* We temporarily reduce the length of the ARGLIST so
6899 that coerce_template_parms will see only the arguments
6900 corresponding to the template parameters it is
6902 TREE_VEC_LENGTH (arglist)--;
6905 /* Restore the ARGLIST to its full size. */
6906 TREE_VEC_LENGTH (arglist) = saved_depth;
6908 arglist = bound_args;
6912 = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parmlist),
6913 INNERMOST_TEMPLATE_ARGS (arglist),
6916 /*require_all_args=*/true,
6917 /*use_default_args=*/true);
6919 if (arglist == error_mark_node)
6920 /* We were unable to bind the arguments. */
6921 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6923 /* In the scope of a template class, explicit references to the
6924 template class refer to the type of the template, not any
6925 instantiation of it. For example, in:
6927 template <class T> class C { void f(C<T>); }
6929 the `C<T>' is just the same as `C'. Outside of the
6930 class, however, such a reference is an instantiation. */
6932 || !PRIMARY_TEMPLATE_P (gen_tmpl)
6933 || currently_open_class (template_type))
6934 /* comp_template_args is expensive, check it last. */
6935 && comp_template_args (TYPE_TI_ARGS (template_type),
6937 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, template_type);
6939 /* If we already have this specialization, return it. */
6940 elt.tmpl = gen_tmpl;
6942 hash = hash_specialization (&elt);
6943 entry = (spec_entry *) htab_find_with_hash (type_specializations,
6947 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, entry->spec);
6949 is_dependent_type = uses_template_parms (arglist);
6951 /* If the deduced arguments are invalid, then the binding
6953 if (!is_dependent_type
6954 && check_instantiated_args (gen_tmpl,
6955 INNERMOST_TEMPLATE_ARGS (arglist),
6957 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6959 if (!is_dependent_type
6960 && !PRIMARY_TEMPLATE_P (gen_tmpl)
6961 && !LAMBDA_TYPE_P (TREE_TYPE (gen_tmpl))
6962 && TREE_CODE (CP_DECL_CONTEXT (gen_tmpl)) == NAMESPACE_DECL)
6964 found = xref_tag_from_type (TREE_TYPE (gen_tmpl),
6965 DECL_NAME (gen_tmpl),
6966 /*tag_scope=*/ts_global);
6967 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, found);
6970 context = tsubst (DECL_CONTEXT (gen_tmpl), arglist,
6973 context = global_namespace;
6975 /* Create the type. */
6976 if (TREE_CODE (template_type) == ENUMERAL_TYPE)
6978 if (!is_dependent_type)
6980 set_current_access_from_decl (TYPE_NAME (template_type));
6981 t = start_enum (TYPE_IDENTIFIER (template_type), NULL_TREE,
6982 tsubst (ENUM_UNDERLYING_TYPE (template_type),
6983 arglist, complain, in_decl),
6984 SCOPED_ENUM_P (template_type), NULL);
6988 /* We don't want to call start_enum for this type, since
6989 the values for the enumeration constants may involve
6990 template parameters. And, no one should be interested
6991 in the enumeration constants for such a type. */
6992 t = cxx_make_type (ENUMERAL_TYPE);
6993 SET_SCOPED_ENUM_P (t, SCOPED_ENUM_P (template_type));
6995 SET_OPAQUE_ENUM_P (t, OPAQUE_ENUM_P (template_type));
6999 t = make_class_type (TREE_CODE (template_type));
7000 CLASSTYPE_DECLARED_CLASS (t)
7001 = CLASSTYPE_DECLARED_CLASS (template_type);
7002 SET_CLASSTYPE_IMPLICIT_INSTANTIATION (t);
7003 TYPE_FOR_JAVA (t) = TYPE_FOR_JAVA (template_type);
7005 /* A local class. Make sure the decl gets registered properly. */
7006 if (context == current_function_decl)
7007 pushtag (DECL_NAME (gen_tmpl), t, /*tag_scope=*/ts_current);
7009 if (comp_template_args (CLASSTYPE_TI_ARGS (template_type), arglist))
7010 /* This instantiation is another name for the primary
7011 template type. Set the TYPE_CANONICAL field
7013 TYPE_CANONICAL (t) = template_type;
7014 else if (any_template_arguments_need_structural_equality_p (arglist))
7015 /* Some of the template arguments require structural
7016 equality testing, so this template class requires
7017 structural equality testing. */
7018 SET_TYPE_STRUCTURAL_EQUALITY (t);
7021 /* If we called start_enum or pushtag above, this information
7022 will already be set up. */
7025 TYPE_CONTEXT (t) = FROB_CONTEXT (context);
7027 type_decl = create_implicit_typedef (DECL_NAME (gen_tmpl), t);
7028 DECL_CONTEXT (type_decl) = TYPE_CONTEXT (t);
7029 DECL_SOURCE_LOCATION (type_decl)
7030 = DECL_SOURCE_LOCATION (TYPE_STUB_DECL (template_type));
7033 type_decl = TYPE_NAME (t);
7035 TREE_PRIVATE (type_decl)
7036 = TREE_PRIVATE (TYPE_STUB_DECL (template_type));
7037 TREE_PROTECTED (type_decl)
7038 = TREE_PROTECTED (TYPE_STUB_DECL (template_type));
7039 if (CLASSTYPE_VISIBILITY_SPECIFIED (template_type))
7041 DECL_VISIBILITY_SPECIFIED (type_decl) = 1;
7042 DECL_VISIBILITY (type_decl) = CLASSTYPE_VISIBILITY (template_type);
7045 /* Let's consider the explicit specialization of a member
7046 of a class template specialization that is implicitely instantiated,
7051 template<class U> struct M {}; //#0
7056 struct S<int>::M<char> //#1
7060 [temp.expl.spec]/4 says this is valid.
7062 In this case, when we write:
7065 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
7068 When we encounter #1, we want to store the partial instantiation
7069 of M (template<class T> S<int>::M<T>) in it's CLASSTYPE_TI_TEMPLATE.
7071 For all cases other than this "explicit specialization of member of a
7072 class template", we just want to store the most general template into
7073 the CLASSTYPE_TI_TEMPLATE of M.
7075 This case of "explicit specialization of member of a class template"
7077 1/ the enclosing class is an instantiation of, and therefore not
7078 the same as, the context of the most general template, and
7079 2/ we aren't looking at the partial instantiation itself, i.e.
7080 the innermost arguments are not the same as the innermost parms of
7081 the most general template.
7083 So it's only when 1/ and 2/ happens that we want to use the partial
7084 instantiation of the member template in lieu of its most general
7087 if (PRIMARY_TEMPLATE_P (gen_tmpl)
7088 && TMPL_ARGS_HAVE_MULTIPLE_LEVELS (arglist)
7089 /* the enclosing class must be an instantiation... */
7090 && CLASS_TYPE_P (context)
7091 && !same_type_p (context, DECL_CONTEXT (gen_tmpl)))
7093 tree partial_inst_args;
7094 TREE_VEC_LENGTH (arglist)--;
7095 ++processing_template_decl;
7097 tsubst (INNERMOST_TEMPLATE_ARGS
7098 (CLASSTYPE_TI_ARGS (TREE_TYPE (gen_tmpl))),
7099 arglist, complain, NULL_TREE);
7100 --processing_template_decl;
7101 TREE_VEC_LENGTH (arglist)++;
7102 use_partial_inst_tmpl =
7103 /*...and we must not be looking at the partial instantiation
7105 !comp_template_args (INNERMOST_TEMPLATE_ARGS (arglist),
7109 if (!use_partial_inst_tmpl)
7110 /* This case is easy; there are no member templates involved. */
7114 /* This is a full instantiation of a member template. Find
7115 the partial instantiation of which this is an instance. */
7117 /* Temporarily reduce by one the number of levels in the ARGLIST
7118 so as to avoid comparing the last set of arguments. */
7119 TREE_VEC_LENGTH (arglist)--;
7120 found = tsubst (gen_tmpl, arglist, complain, NULL_TREE);
7121 TREE_VEC_LENGTH (arglist)++;
7122 found = CLASSTYPE_TI_TEMPLATE (found);
7125 SET_TYPE_TEMPLATE_INFO (t, build_template_info (found, arglist));
7128 slot = (spec_entry **) htab_find_slot_with_hash (type_specializations,
7129 &elt, hash, INSERT);
7130 *slot = ggc_alloc_spec_entry ();
7133 /* Note this use of the partial instantiation so we can check it
7134 later in maybe_process_partial_specialization. */
7135 DECL_TEMPLATE_INSTANTIATIONS (templ)
7136 = tree_cons (arglist, t,
7137 DECL_TEMPLATE_INSTANTIATIONS (templ));
7139 if (TREE_CODE (t) == ENUMERAL_TYPE && !is_dependent_type)
7140 /* Now that the type has been registered on the instantiations
7141 list, we set up the enumerators. Because the enumeration
7142 constants may involve the enumeration type itself, we make
7143 sure to register the type first, and then create the
7144 constants. That way, doing tsubst_expr for the enumeration
7145 constants won't result in recursive calls here; we'll find
7146 the instantiation and exit above. */
7147 tsubst_enum (template_type, t, arglist);
7149 if (is_dependent_type)
7150 /* If the type makes use of template parameters, the
7151 code that generates debugging information will crash. */
7152 DECL_IGNORED_P (TYPE_STUB_DECL (t)) = 1;
7154 /* Possibly limit visibility based on template args. */
7155 TREE_PUBLIC (type_decl) = 1;
7156 determine_visibility (type_decl);
7158 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, t);
7160 timevar_pop (TV_NAME_LOOKUP);
7167 /* True when we should also visit template parameters that occur in
7168 non-deduced contexts. */
7169 bool include_nondeduced_p;
7170 struct pointer_set_t *visited;
7173 /* Called from for_each_template_parm via walk_tree. */
7176 for_each_template_parm_r (tree *tp, int *walk_subtrees, void *d)
7179 struct pair_fn_data *pfd = (struct pair_fn_data *) d;
7180 tree_fn_t fn = pfd->fn;
7181 void *data = pfd->data;
7184 && (pfd->include_nondeduced_p || TREE_CODE (t) != TYPENAME_TYPE)
7185 && for_each_template_parm (TYPE_CONTEXT (t), fn, data, pfd->visited,
7186 pfd->include_nondeduced_p))
7187 return error_mark_node;
7189 switch (TREE_CODE (t))
7192 if (TYPE_PTRMEMFUNC_P (t))
7198 if (!TYPE_TEMPLATE_INFO (t))
7200 else if (for_each_template_parm (TI_ARGS (TYPE_TEMPLATE_INFO (t)),
7201 fn, data, pfd->visited,
7202 pfd->include_nondeduced_p))
7203 return error_mark_node;
7207 if (for_each_template_parm (TYPE_MIN_VALUE (t),
7208 fn, data, pfd->visited,
7209 pfd->include_nondeduced_p)
7210 || for_each_template_parm (TYPE_MAX_VALUE (t),
7211 fn, data, pfd->visited,
7212 pfd->include_nondeduced_p))
7213 return error_mark_node;
7217 /* Since we're not going to walk subtrees, we have to do this
7219 if (for_each_template_parm (TYPE_METHOD_BASETYPE (t), fn, data,
7220 pfd->visited, pfd->include_nondeduced_p))
7221 return error_mark_node;
7225 /* Check the return type. */
7226 if (for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
7227 pfd->include_nondeduced_p))
7228 return error_mark_node;
7230 /* Check the parameter types. Since default arguments are not
7231 instantiated until they are needed, the TYPE_ARG_TYPES may
7232 contain expressions that involve template parameters. But,
7233 no-one should be looking at them yet. And, once they're
7234 instantiated, they don't contain template parameters, so
7235 there's no point in looking at them then, either. */
7239 for (parm = TYPE_ARG_TYPES (t); parm; parm = TREE_CHAIN (parm))
7240 if (for_each_template_parm (TREE_VALUE (parm), fn, data,
7241 pfd->visited, pfd->include_nondeduced_p))
7242 return error_mark_node;
7244 /* Since we've already handled the TYPE_ARG_TYPES, we don't
7245 want walk_tree walking into them itself. */
7251 if (pfd->include_nondeduced_p
7252 && for_each_template_parm (TYPE_FIELDS (t), fn, data,
7254 pfd->include_nondeduced_p))
7255 return error_mark_node;
7260 if (DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t)
7261 && for_each_template_parm (DECL_TI_ARGS (t), fn, data,
7262 pfd->visited, pfd->include_nondeduced_p))
7263 return error_mark_node;
7268 if (TREE_CODE (t) == CONST_DECL && DECL_TEMPLATE_PARM_P (t)
7269 && for_each_template_parm (DECL_INITIAL (t), fn, data,
7270 pfd->visited, pfd->include_nondeduced_p))
7271 return error_mark_node;
7272 if (DECL_CONTEXT (t)
7273 && pfd->include_nondeduced_p
7274 && for_each_template_parm (DECL_CONTEXT (t), fn, data,
7275 pfd->visited, pfd->include_nondeduced_p))
7276 return error_mark_node;
7279 case BOUND_TEMPLATE_TEMPLATE_PARM:
7280 /* Record template parameters such as `T' inside `TT<T>'. */
7281 if (for_each_template_parm (TYPE_TI_ARGS (t), fn, data, pfd->visited,
7282 pfd->include_nondeduced_p))
7283 return error_mark_node;
7286 case TEMPLATE_TEMPLATE_PARM:
7287 case TEMPLATE_TYPE_PARM:
7288 case TEMPLATE_PARM_INDEX:
7289 if (fn && (*fn)(t, data))
7290 return error_mark_node;
7292 return error_mark_node;
7296 /* A template template parameter is encountered. */
7297 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t)
7298 && for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
7299 pfd->include_nondeduced_p))
7300 return error_mark_node;
7302 /* Already substituted template template parameter */
7308 || for_each_template_parm (TYPENAME_TYPE_FULLNAME (t), fn,
7310 pfd->include_nondeduced_p))
7311 return error_mark_node;
7315 if (TREE_TYPE (t) && TYPE_PTRMEMFUNC_P (TREE_TYPE (t))
7316 && pfd->include_nondeduced_p
7317 && for_each_template_parm (TYPE_PTRMEMFUNC_FN_TYPE
7318 (TREE_TYPE (t)), fn, data,
7319 pfd->visited, pfd->include_nondeduced_p))
7320 return error_mark_node;
7325 /* If there's no type, then this thing must be some expression
7326 involving template parameters. */
7327 if (!fn && !TREE_TYPE (t))
7328 return error_mark_node;
7333 case REINTERPRET_CAST_EXPR:
7334 case CONST_CAST_EXPR:
7335 case STATIC_CAST_EXPR:
7336 case DYNAMIC_CAST_EXPR:
7340 case PSEUDO_DTOR_EXPR:
7342 return error_mark_node;
7349 /* We didn't find any template parameters we liked. */
7353 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
7354 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
7355 call FN with the parameter and the DATA.
7356 If FN returns nonzero, the iteration is terminated, and
7357 for_each_template_parm returns 1. Otherwise, the iteration
7358 continues. If FN never returns a nonzero value, the value
7359 returned by for_each_template_parm is 0. If FN is NULL, it is
7360 considered to be the function which always returns 1.
7362 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
7363 parameters that occur in non-deduced contexts. When false, only
7364 visits those template parameters that can be deduced. */
7367 for_each_template_parm (tree t, tree_fn_t fn, void* data,
7368 struct pointer_set_t *visited,
7369 bool include_nondeduced_p)
7371 struct pair_fn_data pfd;
7377 pfd.include_nondeduced_p = include_nondeduced_p;
7379 /* Walk the tree. (Conceptually, we would like to walk without
7380 duplicates, but for_each_template_parm_r recursively calls
7381 for_each_template_parm, so we would need to reorganize a fair
7382 bit to use walk_tree_without_duplicates, so we keep our own
7385 pfd.visited = visited;
7387 pfd.visited = pointer_set_create ();
7388 result = cp_walk_tree (&t,
7389 for_each_template_parm_r,
7391 pfd.visited) != NULL_TREE;
7396 pointer_set_destroy (pfd.visited);
7403 /* Returns true if T depends on any template parameter. */
7406 uses_template_parms (tree t)
7409 int saved_processing_template_decl;
7411 saved_processing_template_decl = processing_template_decl;
7412 if (!saved_processing_template_decl)
7413 processing_template_decl = 1;
7415 dependent_p = dependent_type_p (t);
7416 else if (TREE_CODE (t) == TREE_VEC)
7417 dependent_p = any_dependent_template_arguments_p (t);
7418 else if (TREE_CODE (t) == TREE_LIST)
7419 dependent_p = (uses_template_parms (TREE_VALUE (t))
7420 || uses_template_parms (TREE_CHAIN (t)));
7421 else if (TREE_CODE (t) == TYPE_DECL)
7422 dependent_p = dependent_type_p (TREE_TYPE (t));
7425 || TREE_CODE (t) == TEMPLATE_PARM_INDEX
7426 || TREE_CODE (t) == OVERLOAD
7427 || TREE_CODE (t) == BASELINK
7428 || TREE_CODE (t) == IDENTIFIER_NODE
7429 || TREE_CODE (t) == TRAIT_EXPR
7430 || TREE_CODE (t) == CONSTRUCTOR
7431 || CONSTANT_CLASS_P (t))
7432 dependent_p = (type_dependent_expression_p (t)
7433 || value_dependent_expression_p (t));
7436 gcc_assert (t == error_mark_node);
7437 dependent_p = false;
7440 processing_template_decl = saved_processing_template_decl;
7445 /* Returns true if T depends on any template parameter with level LEVEL. */
7448 uses_template_parms_level (tree t, int level)
7450 return for_each_template_parm (t, template_parm_this_level_p, &level, NULL,
7451 /*include_nondeduced_p=*/true);
7454 static int tinst_depth;
7455 extern int max_tinst_depth;
7456 #ifdef GATHER_STATISTICS
7459 static int tinst_level_tick;
7460 static int last_template_error_tick;
7462 /* We're starting to instantiate D; record the template instantiation context
7463 for diagnostics and to restore it later. */
7466 push_tinst_level (tree d)
7468 struct tinst_level *new_level;
7470 if (tinst_depth >= max_tinst_depth)
7472 /* If the instantiation in question still has unbound template parms,
7473 we don't really care if we can't instantiate it, so just return.
7474 This happens with base instantiation for implicit `typename'. */
7475 if (uses_template_parms (d))
7478 last_template_error_tick = tinst_level_tick;
7479 error ("template instantiation depth exceeds maximum of %d (use "
7480 "-ftemplate-depth= to increase the maximum) instantiating %qD",
7481 max_tinst_depth, d);
7483 print_instantiation_context ();
7488 new_level = ggc_alloc_tinst_level ();
7489 new_level->decl = d;
7490 new_level->locus = input_location;
7491 new_level->in_system_header_p = in_system_header;
7492 new_level->next = current_tinst_level;
7493 current_tinst_level = new_level;
7496 #ifdef GATHER_STATISTICS
7497 if (tinst_depth > depth_reached)
7498 depth_reached = tinst_depth;
7505 /* We're done instantiating this template; return to the instantiation
7509 pop_tinst_level (void)
7511 /* Restore the filename and line number stashed away when we started
7512 this instantiation. */
7513 input_location = current_tinst_level->locus;
7514 current_tinst_level = current_tinst_level->next;
7519 /* We're instantiating a deferred template; restore the template
7520 instantiation context in which the instantiation was requested, which
7521 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
7524 reopen_tinst_level (struct tinst_level *level)
7526 struct tinst_level *t;
7529 for (t = level; t; t = t->next)
7532 current_tinst_level = level;
7537 /* Returns the TINST_LEVEL which gives the original instantiation
7540 struct tinst_level *
7541 outermost_tinst_level (void)
7543 struct tinst_level *level = current_tinst_level;
7546 level = level->next;
7550 /* Returns TRUE if PARM is a parameter of the template TEMPL. */
7553 parameter_of_template_p (tree parm, tree templ)
7558 if (!parm || !templ)
7561 gcc_assert (DECL_TEMPLATE_PARM_P (parm));
7562 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
7564 parms = DECL_TEMPLATE_PARMS (templ);
7565 parms = INNERMOST_TEMPLATE_PARMS (parms);
7567 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
7568 if (parm == TREE_VALUE (TREE_VEC_ELT (parms, i)))
7574 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
7575 vector of template arguments, as for tsubst.
7577 Returns an appropriate tsubst'd friend declaration. */
7580 tsubst_friend_function (tree decl, tree args)
7584 if (TREE_CODE (decl) == FUNCTION_DECL
7585 && DECL_TEMPLATE_INSTANTIATION (decl)
7586 && TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
7587 /* This was a friend declared with an explicit template
7588 argument list, e.g.:
7592 to indicate that f was a template instantiation, not a new
7593 function declaration. Now, we have to figure out what
7594 instantiation of what template. */
7596 tree template_id, arglist, fns;
7599 tree ns = decl_namespace_context (TYPE_MAIN_DECL (current_class_type));
7601 /* Friend functions are looked up in the containing namespace scope.
7602 We must enter that scope, to avoid finding member functions of the
7603 current class with same name. */
7604 push_nested_namespace (ns);
7605 fns = tsubst_expr (DECL_TI_TEMPLATE (decl), args,
7606 tf_warning_or_error, NULL_TREE,
7607 /*integral_constant_expression_p=*/false);
7608 pop_nested_namespace (ns);
7609 arglist = tsubst (DECL_TI_ARGS (decl), args,
7610 tf_warning_or_error, NULL_TREE);
7611 template_id = lookup_template_function (fns, arglist);
7613 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
7614 tmpl = determine_specialization (template_id, new_friend,
7616 /*need_member_template=*/0,
7617 TREE_VEC_LENGTH (args),
7619 return instantiate_template (tmpl, new_args, tf_error);
7622 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
7624 /* The NEW_FRIEND will look like an instantiation, to the
7625 compiler, but is not an instantiation from the point of view of
7626 the language. For example, we might have had:
7628 template <class T> struct S {
7629 template <class U> friend void f(T, U);
7632 Then, in S<int>, template <class U> void f(int, U) is not an
7633 instantiation of anything. */
7634 if (new_friend == error_mark_node)
7635 return error_mark_node;
7637 DECL_USE_TEMPLATE (new_friend) = 0;
7638 if (TREE_CODE (decl) == TEMPLATE_DECL)
7640 DECL_USE_TEMPLATE (DECL_TEMPLATE_RESULT (new_friend)) = 0;
7641 DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (new_friend))
7642 = DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (decl));
7645 /* The mangled name for the NEW_FRIEND is incorrect. The function
7646 is not a template instantiation and should not be mangled like
7647 one. Therefore, we forget the mangling here; we'll recompute it
7648 later if we need it. */
7649 if (TREE_CODE (new_friend) != TEMPLATE_DECL)
7651 SET_DECL_RTL (new_friend, NULL);
7652 SET_DECL_ASSEMBLER_NAME (new_friend, NULL_TREE);
7655 if (DECL_NAMESPACE_SCOPE_P (new_friend))
7658 tree new_friend_template_info;
7659 tree new_friend_result_template_info;
7661 int new_friend_is_defn;
7663 /* We must save some information from NEW_FRIEND before calling
7664 duplicate decls since that function will free NEW_FRIEND if
7666 new_friend_template_info = DECL_TEMPLATE_INFO (new_friend);
7667 new_friend_is_defn =
7668 (DECL_INITIAL (DECL_TEMPLATE_RESULT
7669 (template_for_substitution (new_friend)))
7671 if (TREE_CODE (new_friend) == TEMPLATE_DECL)
7673 /* This declaration is a `primary' template. */
7674 DECL_PRIMARY_TEMPLATE (new_friend) = new_friend;
7676 new_friend_result_template_info
7677 = DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (new_friend));
7680 new_friend_result_template_info = NULL_TREE;
7682 /* Make the init_value nonzero so pushdecl knows this is a defn. */
7683 if (new_friend_is_defn)
7684 DECL_INITIAL (new_friend) = error_mark_node;
7686 /* Inside pushdecl_namespace_level, we will push into the
7687 current namespace. However, the friend function should go
7688 into the namespace of the template. */
7689 ns = decl_namespace_context (new_friend);
7690 push_nested_namespace (ns);
7691 old_decl = pushdecl_namespace_level (new_friend, /*is_friend=*/true);
7692 pop_nested_namespace (ns);
7694 if (old_decl == error_mark_node)
7695 return error_mark_node;
7697 if (old_decl != new_friend)
7699 /* This new friend declaration matched an existing
7700 declaration. For example, given:
7702 template <class T> void f(T);
7703 template <class U> class C {
7704 template <class T> friend void f(T) {}
7707 the friend declaration actually provides the definition
7708 of `f', once C has been instantiated for some type. So,
7709 old_decl will be the out-of-class template declaration,
7710 while new_friend is the in-class definition.
7712 But, if `f' was called before this point, the
7713 instantiation of `f' will have DECL_TI_ARGS corresponding
7714 to `T' but not to `U', references to which might appear
7715 in the definition of `f'. Previously, the most general
7716 template for an instantiation of `f' was the out-of-class
7717 version; now it is the in-class version. Therefore, we
7718 run through all specialization of `f', adding to their
7719 DECL_TI_ARGS appropriately. In particular, they need a
7720 new set of outer arguments, corresponding to the
7721 arguments for this class instantiation.
7723 The same situation can arise with something like this:
7726 template <class T> class C {
7730 when `C<int>' is instantiated. Now, `f(int)' is defined
7733 if (!new_friend_is_defn)
7734 /* On the other hand, if the in-class declaration does
7735 *not* provide a definition, then we don't want to alter
7736 existing definitions. We can just leave everything
7741 tree new_template = TI_TEMPLATE (new_friend_template_info);
7742 tree new_args = TI_ARGS (new_friend_template_info);
7744 /* Overwrite whatever template info was there before, if
7745 any, with the new template information pertaining to
7747 DECL_TEMPLATE_INFO (old_decl) = new_friend_template_info;
7749 if (TREE_CODE (old_decl) != TEMPLATE_DECL)
7751 /* We should have called reregister_specialization in
7753 gcc_assert (retrieve_specialization (new_template,
7757 /* Instantiate it if the global has already been used. */
7758 if (DECL_ODR_USED (old_decl))
7759 instantiate_decl (old_decl, /*defer_ok=*/true,
7760 /*expl_inst_class_mem_p=*/false);
7766 /* Indicate that the old function template is a partial
7768 DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (old_decl))
7769 = new_friend_result_template_info;
7771 gcc_assert (new_template
7772 == most_general_template (new_template));
7773 gcc_assert (new_template != old_decl);
7775 /* Reassign any specializations already in the hash table
7776 to the new more general template, and add the
7777 additional template args. */
7778 for (t = DECL_TEMPLATE_INSTANTIATIONS (old_decl);
7782 tree spec = TREE_VALUE (t);
7785 elt.tmpl = old_decl;
7786 elt.args = DECL_TI_ARGS (spec);
7787 elt.spec = NULL_TREE;
7789 htab_remove_elt (decl_specializations, &elt);
7792 = add_outermost_template_args (new_args,
7793 DECL_TI_ARGS (spec));
7795 register_specialization
7796 (spec, new_template, DECL_TI_ARGS (spec), true, 0);
7799 DECL_TEMPLATE_INSTANTIATIONS (old_decl) = NULL_TREE;
7803 /* The information from NEW_FRIEND has been merged into OLD_DECL
7804 by duplicate_decls. */
7805 new_friend = old_decl;
7810 tree context = DECL_CONTEXT (new_friend);
7814 template <class T> class C {
7815 template <class U> friend void C1<U>::f (); // case 1
7816 friend void C2<T>::f (); // case 2
7818 we only need to make sure CONTEXT is a complete type for
7819 case 2. To distinguish between the two cases, we note that
7820 CONTEXT of case 1 remains dependent type after tsubst while
7821 this isn't true for case 2. */
7822 ++processing_template_decl;
7823 dependent_p = dependent_type_p (context);
7824 --processing_template_decl;
7827 && !complete_type_or_else (context, NULL_TREE))
7828 return error_mark_node;
7830 if (COMPLETE_TYPE_P (context))
7832 /* Check to see that the declaration is really present, and,
7833 possibly obtain an improved declaration. */
7834 tree fn = check_classfn (context,
7835 new_friend, NULL_TREE);
7845 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
7846 template arguments, as for tsubst.
7848 Returns an appropriate tsubst'd friend type or error_mark_node on
7852 tsubst_friend_class (tree friend_tmpl, tree args)
7858 context = CP_DECL_CONTEXT (friend_tmpl);
7860 if (context != global_namespace)
7862 if (TREE_CODE (context) == NAMESPACE_DECL)
7863 push_nested_namespace (context);
7865 push_nested_class (tsubst (context, args, tf_none, NULL_TREE));
7868 /* Look for a class template declaration. We look for hidden names
7869 because two friend declarations of the same template are the
7870 same. For example, in:
7873 template <typename> friend class F;
7875 template <typename> struct B {
7876 template <typename> friend class F;
7879 both F templates are the same. */
7880 tmpl = lookup_name_real (DECL_NAME (friend_tmpl), 0, 0,
7881 /*block_p=*/true, 0,
7882 LOOKUP_COMPLAIN | LOOKUP_HIDDEN);
7884 /* But, if we don't find one, it might be because we're in a
7885 situation like this:
7893 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
7894 for `S<int>', not the TEMPLATE_DECL. */
7895 if (!tmpl || !DECL_CLASS_TEMPLATE_P (tmpl))
7897 tmpl = lookup_name_prefer_type (DECL_NAME (friend_tmpl), 1);
7898 tmpl = maybe_get_template_decl_from_type_decl (tmpl);
7901 if (tmpl && DECL_CLASS_TEMPLATE_P (tmpl))
7903 /* The friend template has already been declared. Just
7904 check to see that the declarations match, and install any new
7905 default parameters. We must tsubst the default parameters,
7906 of course. We only need the innermost template parameters
7907 because that is all that redeclare_class_template will look
7909 if (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (friend_tmpl))
7910 > TMPL_ARGS_DEPTH (args))
7913 location_t saved_input_location;
7914 parms = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_tmpl),
7915 args, tf_warning_or_error);
7917 saved_input_location = input_location;
7918 input_location = DECL_SOURCE_LOCATION (friend_tmpl);
7919 redeclare_class_template (TREE_TYPE (tmpl), parms);
7920 input_location = saved_input_location;
7924 friend_type = TREE_TYPE (tmpl);
7928 /* The friend template has not already been declared. In this
7929 case, the instantiation of the template class will cause the
7930 injection of this template into the global scope. */
7931 tmpl = tsubst (friend_tmpl, args, tf_warning_or_error, NULL_TREE);
7932 if (tmpl == error_mark_node)
7933 return error_mark_node;
7935 /* The new TMPL is not an instantiation of anything, so we
7936 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
7937 the new type because that is supposed to be the corresponding
7938 template decl, i.e., TMPL. */
7939 DECL_USE_TEMPLATE (tmpl) = 0;
7940 DECL_TEMPLATE_INFO (tmpl) = NULL_TREE;
7941 CLASSTYPE_USE_TEMPLATE (TREE_TYPE (tmpl)) = 0;
7942 CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl))
7943 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl)));
7945 /* Inject this template into the global scope. */
7946 friend_type = TREE_TYPE (pushdecl_top_level_maybe_friend (tmpl, true));
7949 if (context != global_namespace)
7951 if (TREE_CODE (context) == NAMESPACE_DECL)
7952 pop_nested_namespace (context);
7954 pop_nested_class ();
7960 /* Returns zero if TYPE cannot be completed later due to circularity.
7961 Otherwise returns one. */
7964 can_complete_type_without_circularity (tree type)
7966 if (type == NULL_TREE || type == error_mark_node)
7968 else if (COMPLETE_TYPE_P (type))
7970 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
7971 return can_complete_type_without_circularity (TREE_TYPE (type));
7972 else if (CLASS_TYPE_P (type)
7973 && TYPE_BEING_DEFINED (TYPE_MAIN_VARIANT (type)))
7979 /* Apply any attributes which had to be deferred until instantiation
7980 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
7981 ARGS, COMPLAIN, IN_DECL are as tsubst. */
7984 apply_late_template_attributes (tree *decl_p, tree attributes, int attr_flags,
7985 tree args, tsubst_flags_t complain, tree in_decl)
7987 tree last_dep = NULL_TREE;
7991 for (t = attributes; t; t = TREE_CHAIN (t))
7992 if (ATTR_IS_DEPENDENT (t))
7995 attributes = copy_list (attributes);
7999 if (DECL_P (*decl_p))
8001 if (TREE_TYPE (*decl_p) == error_mark_node)
8003 p = &DECL_ATTRIBUTES (*decl_p);
8006 p = &TYPE_ATTRIBUTES (*decl_p);
8010 tree late_attrs = NULL_TREE;
8011 tree *q = &late_attrs;
8013 for (*p = attributes; *p; )
8016 if (ATTR_IS_DEPENDENT (t))
8018 *p = TREE_CHAIN (t);
8019 TREE_CHAIN (t) = NULL_TREE;
8020 /* If the first attribute argument is an identifier, don't
8021 pass it through tsubst. Attributes like mode, format,
8022 cleanup and several target specific attributes expect it
8025 && TREE_CODE (TREE_VALUE (t)) == TREE_LIST
8026 && TREE_VALUE (TREE_VALUE (t))
8027 && (TREE_CODE (TREE_VALUE (TREE_VALUE (t)))
8028 == IDENTIFIER_NODE))
8031 = tsubst_expr (TREE_CHAIN (TREE_VALUE (t)), args, complain,
8033 /*integral_constant_expression_p=*/false);
8034 if (chain != TREE_CHAIN (TREE_VALUE (t)))
8036 = tree_cons (NULL_TREE, TREE_VALUE (TREE_VALUE (t)),
8041 = tsubst_expr (TREE_VALUE (t), args, complain, in_decl,
8042 /*integral_constant_expression_p=*/false);
8044 q = &TREE_CHAIN (t);
8047 p = &TREE_CHAIN (t);
8050 cplus_decl_attributes (decl_p, late_attrs, attr_flags);
8054 /* Perform (or defer) access check for typedefs that were referenced
8055 from within the template TMPL code.
8056 This is a subroutine of instantiate_template and instantiate_class_template.
8057 TMPL is the template to consider and TARGS is the list of arguments of
8061 perform_typedefs_access_check (tree tmpl, tree targs)
8063 location_t saved_location;
8065 qualified_typedef_usage_t *iter;
8068 || (!CLASS_TYPE_P (tmpl)
8069 && TREE_CODE (tmpl) != FUNCTION_DECL))
8072 saved_location = input_location;
8073 FOR_EACH_VEC_ELT (qualified_typedef_usage_t,
8074 get_types_needing_access_check (tmpl),
8077 tree type_decl = iter->typedef_decl;
8078 tree type_scope = iter->context;
8080 if (!type_decl || !type_scope || !CLASS_TYPE_P (type_scope))
8083 if (uses_template_parms (type_decl))
8084 type_decl = tsubst (type_decl, targs, tf_error, NULL_TREE);
8085 if (uses_template_parms (type_scope))
8086 type_scope = tsubst (type_scope, targs, tf_error, NULL_TREE);
8088 /* Make access check error messages point to the location
8089 of the use of the typedef. */
8090 input_location = iter->locus;
8091 perform_or_defer_access_check (TYPE_BINFO (type_scope),
8092 type_decl, type_decl);
8094 input_location = saved_location;
8098 instantiate_class_template (tree type)
8100 tree templ, args, pattern, t, member;
8104 unsigned int saved_maximum_field_alignment;
8106 if (type == error_mark_node)
8107 return error_mark_node;
8109 if (COMPLETE_OR_OPEN_TYPE_P (type)
8110 || uses_template_parms (type))
8113 /* Figure out which template is being instantiated. */
8114 templ = most_general_template (CLASSTYPE_TI_TEMPLATE (type));
8115 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
8117 /* Determine what specialization of the original template to
8119 t = most_specialized_class (type, templ, tf_warning_or_error);
8120 if (t == error_mark_node)
8122 TYPE_BEING_DEFINED (type) = 1;
8123 return error_mark_node;
8127 /* This TYPE is actually an instantiation of a partial
8128 specialization. We replace the innermost set of ARGS with
8129 the arguments appropriate for substitution. For example,
8132 template <class T> struct S {};
8133 template <class T> struct S<T*> {};
8135 and supposing that we are instantiating S<int*>, ARGS will
8136 presently be {int*} -- but we need {int}. */
8137 pattern = TREE_TYPE (t);
8138 args = TREE_PURPOSE (t);
8142 pattern = TREE_TYPE (templ);
8143 args = CLASSTYPE_TI_ARGS (type);
8146 /* If the template we're instantiating is incomplete, then clearly
8147 there's nothing we can do. */
8148 if (!COMPLETE_TYPE_P (pattern))
8151 /* If we've recursively instantiated too many templates, stop. */
8152 if (! push_tinst_level (type))
8155 /* Now we're really doing the instantiation. Mark the type as in
8156 the process of being defined. */
8157 TYPE_BEING_DEFINED (type) = 1;
8159 /* We may be in the middle of deferred access check. Disable
8161 push_deferring_access_checks (dk_no_deferred);
8163 push_to_top_level ();
8164 /* Use #pragma pack from the template context. */
8165 saved_maximum_field_alignment = maximum_field_alignment;
8166 maximum_field_alignment = TYPE_PRECISION (pattern);
8168 SET_CLASSTYPE_INTERFACE_UNKNOWN (type);
8170 /* Set the input location to the most specialized template definition.
8171 This is needed if tsubsting causes an error. */
8172 typedecl = TYPE_MAIN_DECL (pattern);
8173 input_location = DECL_SOURCE_LOCATION (TYPE_NAME (type)) =
8174 DECL_SOURCE_LOCATION (typedecl);
8176 TYPE_HAS_USER_CONSTRUCTOR (type) = TYPE_HAS_USER_CONSTRUCTOR (pattern);
8177 TYPE_HAS_NEW_OPERATOR (type) = TYPE_HAS_NEW_OPERATOR (pattern);
8178 TYPE_HAS_ARRAY_NEW_OPERATOR (type) = TYPE_HAS_ARRAY_NEW_OPERATOR (pattern);
8179 TYPE_GETS_DELETE (type) = TYPE_GETS_DELETE (pattern);
8180 TYPE_HAS_COPY_ASSIGN (type) = TYPE_HAS_COPY_ASSIGN (pattern);
8181 TYPE_HAS_CONST_COPY_ASSIGN (type) = TYPE_HAS_CONST_COPY_ASSIGN (pattern);
8182 TYPE_HAS_COPY_CTOR (type) = TYPE_HAS_COPY_CTOR (pattern);
8183 TYPE_HAS_CONST_COPY_CTOR (type) = TYPE_HAS_CONST_COPY_CTOR (pattern);
8184 TYPE_HAS_DEFAULT_CONSTRUCTOR (type) = TYPE_HAS_DEFAULT_CONSTRUCTOR (pattern);
8185 TYPE_HAS_CONVERSION (type) = TYPE_HAS_CONVERSION (pattern);
8186 TYPE_PACKED (type) = TYPE_PACKED (pattern);
8187 TYPE_ALIGN (type) = TYPE_ALIGN (pattern);
8188 TYPE_USER_ALIGN (type) = TYPE_USER_ALIGN (pattern);
8189 TYPE_FOR_JAVA (type) = TYPE_FOR_JAVA (pattern); /* For libjava's JArray<T> */
8190 if (ANON_AGGR_TYPE_P (pattern))
8191 SET_ANON_AGGR_TYPE_P (type);
8192 if (CLASSTYPE_VISIBILITY_SPECIFIED (pattern))
8194 CLASSTYPE_VISIBILITY_SPECIFIED (type) = 1;
8195 CLASSTYPE_VISIBILITY (type) = CLASSTYPE_VISIBILITY (pattern);
8198 pbinfo = TYPE_BINFO (pattern);
8200 /* We should never instantiate a nested class before its enclosing
8201 class; we need to look up the nested class by name before we can
8202 instantiate it, and that lookup should instantiate the enclosing
8204 gcc_assert (!DECL_CLASS_SCOPE_P (TYPE_MAIN_DECL (pattern))
8205 || COMPLETE_OR_OPEN_TYPE_P (TYPE_CONTEXT (type)));
8207 base_list = NULL_TREE;
8208 if (BINFO_N_BASE_BINFOS (pbinfo))
8214 /* We must enter the scope containing the type, as that is where
8215 the accessibility of types named in dependent bases are
8217 pushed_scope = push_scope (CP_TYPE_CONTEXT (type));
8219 /* Substitute into each of the bases to determine the actual
8221 for (i = 0; BINFO_BASE_ITERATE (pbinfo, i, pbase_binfo); i++)
8224 tree access = BINFO_BASE_ACCESS (pbinfo, i);
8225 tree expanded_bases = NULL_TREE;
8228 if (PACK_EXPANSION_P (BINFO_TYPE (pbase_binfo)))
8231 tsubst_pack_expansion (BINFO_TYPE (pbase_binfo),
8232 args, tf_error, NULL_TREE);
8233 if (expanded_bases == error_mark_node)
8236 len = TREE_VEC_LENGTH (expanded_bases);
8239 for (idx = 0; idx < len; idx++)
8242 /* Extract the already-expanded base class. */
8243 base = TREE_VEC_ELT (expanded_bases, idx);
8245 /* Substitute to figure out the base class. */
8246 base = tsubst (BINFO_TYPE (pbase_binfo), args, tf_error,
8249 if (base == error_mark_node)
8252 base_list = tree_cons (access, base, base_list);
8253 if (BINFO_VIRTUAL_P (pbase_binfo))
8254 TREE_TYPE (base_list) = integer_type_node;
8258 /* The list is now in reverse order; correct that. */
8259 base_list = nreverse (base_list);
8262 pop_scope (pushed_scope);
8264 /* Now call xref_basetypes to set up all the base-class
8266 xref_basetypes (type, base_list);
8268 apply_late_template_attributes (&type, TYPE_ATTRIBUTES (pattern),
8269 (int) ATTR_FLAG_TYPE_IN_PLACE,
8270 args, tf_error, NULL_TREE);
8271 fixup_attribute_variants (type);
8273 /* Now that our base classes are set up, enter the scope of the
8274 class, so that name lookups into base classes, etc. will work
8275 correctly. This is precisely analogous to what we do in
8276 begin_class_definition when defining an ordinary non-template
8277 class, except we also need to push the enclosing classes. */
8278 push_nested_class (type);
8280 /* Now members are processed in the order of declaration. */
8281 for (member = CLASSTYPE_DECL_LIST (pattern);
8282 member; member = TREE_CHAIN (member))
8284 tree t = TREE_VALUE (member);
8286 if (TREE_PURPOSE (member))
8290 /* Build new CLASSTYPE_NESTED_UTDS. */
8293 bool class_template_p;
8295 class_template_p = (TREE_CODE (t) != ENUMERAL_TYPE
8296 && TYPE_LANG_SPECIFIC (t)
8297 && CLASSTYPE_IS_TEMPLATE (t));
8298 /* If the member is a class template, then -- even after
8299 substitution -- there may be dependent types in the
8300 template argument list for the class. We increment
8301 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
8302 that function will assume that no types are dependent
8303 when outside of a template. */
8304 if (class_template_p)
8305 ++processing_template_decl;
8306 newtag = tsubst (t, args, tf_error, NULL_TREE);
8307 if (class_template_p)
8308 --processing_template_decl;
8309 if (newtag == error_mark_node)
8312 if (TREE_CODE (newtag) != ENUMERAL_TYPE)
8314 tree name = TYPE_IDENTIFIER (t);
8316 if (class_template_p)
8317 /* Unfortunately, lookup_template_class sets
8318 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
8319 instantiation (i.e., for the type of a member
8320 template class nested within a template class.)
8321 This behavior is required for
8322 maybe_process_partial_specialization to work
8323 correctly, but is not accurate in this case;
8324 the TAG is not an instantiation of anything.
8325 (The corresponding TEMPLATE_DECL is an
8326 instantiation, but the TYPE is not.) */
8327 CLASSTYPE_USE_TEMPLATE (newtag) = 0;
8329 /* Now, we call pushtag to put this NEWTAG into the scope of
8330 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
8331 pushtag calling push_template_decl. We don't have to do
8332 this for enums because it will already have been done in
8335 SET_IDENTIFIER_TYPE_VALUE (name, newtag);
8336 pushtag (name, newtag, /*tag_scope=*/ts_current);
8339 else if (TREE_CODE (t) == FUNCTION_DECL
8340 || DECL_FUNCTION_TEMPLATE_P (t))
8342 /* Build new TYPE_METHODS. */
8345 if (TREE_CODE (t) == TEMPLATE_DECL)
8346 ++processing_template_decl;
8347 r = tsubst (t, args, tf_error, NULL_TREE);
8348 if (TREE_CODE (t) == TEMPLATE_DECL)
8349 --processing_template_decl;
8350 set_current_access_from_decl (r);
8351 finish_member_declaration (r);
8355 /* Build new TYPE_FIELDS. */
8356 if (TREE_CODE (t) == STATIC_ASSERT)
8359 tsubst_expr (STATIC_ASSERT_CONDITION (t), args,
8360 tf_warning_or_error, NULL_TREE,
8361 /*integral_constant_expression_p=*/true);
8362 finish_static_assert (condition,
8363 STATIC_ASSERT_MESSAGE (t),
8364 STATIC_ASSERT_SOURCE_LOCATION (t),
8367 else if (TREE_CODE (t) != CONST_DECL)
8371 /* The file and line for this declaration, to
8372 assist in error message reporting. Since we
8373 called push_tinst_level above, we don't need to
8375 input_location = DECL_SOURCE_LOCATION (t);
8377 if (TREE_CODE (t) == TEMPLATE_DECL)
8378 ++processing_template_decl;
8379 r = tsubst (t, args, tf_warning_or_error, NULL_TREE);
8380 if (TREE_CODE (t) == TEMPLATE_DECL)
8381 --processing_template_decl;
8382 if (TREE_CODE (r) == VAR_DECL)
8386 [t]he initialization (and any associated
8387 side-effects) of a static data member does
8388 not occur unless the static data member is
8389 itself used in a way that requires the
8390 definition of the static data member to
8393 Therefore, we do not substitute into the
8394 initialized for the static data member here. */
8395 finish_static_data_member_decl
8398 /*init_const_expr_p=*/false,
8399 /*asmspec_tree=*/NULL_TREE,
8401 if (DECL_INITIALIZED_IN_CLASS_P (r))
8402 check_static_variable_definition (r, TREE_TYPE (r));
8404 else if (TREE_CODE (r) == FIELD_DECL)
8406 /* Determine whether R has a valid type and can be
8407 completed later. If R is invalid, then it is
8408 replaced by error_mark_node so that it will not be
8409 added to TYPE_FIELDS. */
8410 tree rtype = TREE_TYPE (r);
8411 if (can_complete_type_without_circularity (rtype))
8412 complete_type (rtype);
8414 if (!COMPLETE_TYPE_P (rtype))
8416 cxx_incomplete_type_error (r, rtype);
8417 r = error_mark_node;
8421 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
8422 such a thing will already have been added to the field
8423 list by tsubst_enum in finish_member_declaration in the
8424 CLASSTYPE_NESTED_UTDS case above. */
8425 if (!(TREE_CODE (r) == TYPE_DECL
8426 && TREE_CODE (TREE_TYPE (r)) == ENUMERAL_TYPE
8427 && DECL_ARTIFICIAL (r)))
8429 set_current_access_from_decl (r);
8430 finish_member_declaration (r);
8437 if (TYPE_P (t) || DECL_CLASS_TEMPLATE_P (t))
8439 /* Build new CLASSTYPE_FRIEND_CLASSES. */
8441 tree friend_type = t;
8442 bool adjust_processing_template_decl = false;
8444 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
8446 /* template <class T> friend class C; */
8447 friend_type = tsubst_friend_class (friend_type, args);
8448 adjust_processing_template_decl = true;
8450 else if (TREE_CODE (friend_type) == UNBOUND_CLASS_TEMPLATE)
8452 /* template <class T> friend class C::D; */
8453 friend_type = tsubst (friend_type, args,
8454 tf_warning_or_error, NULL_TREE);
8455 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
8456 friend_type = TREE_TYPE (friend_type);
8457 adjust_processing_template_decl = true;
8459 else if (TREE_CODE (friend_type) == TYPENAME_TYPE)
8461 /* This could be either
8465 when dependent_type_p is false or
8467 template <class U> friend class T::C;
8470 friend_type = tsubst (friend_type, args,
8471 tf_warning_or_error, NULL_TREE);
8472 /* Bump processing_template_decl for correct
8473 dependent_type_p calculation. */
8474 ++processing_template_decl;
8475 if (dependent_type_p (friend_type))
8476 adjust_processing_template_decl = true;
8477 --processing_template_decl;
8479 else if (!CLASSTYPE_USE_TEMPLATE (friend_type)
8480 && hidden_name_p (TYPE_NAME (friend_type)))
8484 where C hasn't been declared yet. Let's lookup name
8485 from namespace scope directly, bypassing any name that
8486 come from dependent base class. */
8487 tree ns = decl_namespace_context (TYPE_MAIN_DECL (friend_type));
8489 /* The call to xref_tag_from_type does injection for friend
8491 push_nested_namespace (ns);
8493 xref_tag_from_type (friend_type, NULL_TREE,
8494 /*tag_scope=*/ts_current);
8495 pop_nested_namespace (ns);
8497 else if (uses_template_parms (friend_type))
8498 /* friend class C<T>; */
8499 friend_type = tsubst (friend_type, args,
8500 tf_warning_or_error, NULL_TREE);
8505 where C is already declared or
8507 friend class C<int>;
8509 We don't have to do anything in these cases. */
8511 if (adjust_processing_template_decl)
8512 /* Trick make_friend_class into realizing that the friend
8513 we're adding is a template, not an ordinary class. It's
8514 important that we use make_friend_class since it will
8515 perform some error-checking and output cross-reference
8517 ++processing_template_decl;
8519 if (friend_type != error_mark_node)
8520 make_friend_class (type, friend_type, /*complain=*/false);
8522 if (adjust_processing_template_decl)
8523 --processing_template_decl;
8527 /* Build new DECL_FRIENDLIST. */
8530 /* The file and line for this declaration, to
8531 assist in error message reporting. Since we
8532 called push_tinst_level above, we don't need to
8534 input_location = DECL_SOURCE_LOCATION (t);
8536 if (TREE_CODE (t) == TEMPLATE_DECL)
8538 ++processing_template_decl;
8539 push_deferring_access_checks (dk_no_check);
8542 r = tsubst_friend_function (t, args);
8543 add_friend (type, r, /*complain=*/false);
8544 if (TREE_CODE (t) == TEMPLATE_DECL)
8546 pop_deferring_access_checks ();
8547 --processing_template_decl;
8553 /* Set the file and line number information to whatever is given for
8554 the class itself. This puts error messages involving generated
8555 implicit functions at a predictable point, and the same point
8556 that would be used for non-template classes. */
8557 input_location = DECL_SOURCE_LOCATION (typedecl);
8559 unreverse_member_declarations (type);
8560 finish_struct_1 (type);
8561 TYPE_BEING_DEFINED (type) = 0;
8563 /* We don't instantiate default arguments for member functions. 14.7.1:
8565 The implicit instantiation of a class template specialization causes
8566 the implicit instantiation of the declarations, but not of the
8567 definitions or default arguments, of the class member functions,
8568 member classes, static data members and member templates.... */
8570 /* Some typedefs referenced from within the template code need to be access
8571 checked at template instantiation time, i.e now. These types were
8572 added to the template at parsing time. Let's get those and perform
8573 the access checks then. */
8574 perform_typedefs_access_check (pattern, args);
8575 perform_deferred_access_checks ();
8576 pop_nested_class ();
8577 maximum_field_alignment = saved_maximum_field_alignment;
8578 pop_from_top_level ();
8579 pop_deferring_access_checks ();
8582 /* The vtable for a template class can be emitted in any translation
8583 unit in which the class is instantiated. When there is no key
8584 method, however, finish_struct_1 will already have added TYPE to
8585 the keyed_classes list. */
8586 if (TYPE_CONTAINS_VPTR_P (type) && CLASSTYPE_KEY_METHOD (type))
8587 keyed_classes = tree_cons (NULL_TREE, type, keyed_classes);
8593 tsubst_template_arg (tree t, tree args, tsubst_flags_t complain, tree in_decl)
8599 else if (TYPE_P (t))
8600 r = tsubst (t, args, complain, in_decl);
8603 if (!(complain & tf_warning))
8604 ++c_inhibit_evaluation_warnings;
8605 r = tsubst_expr (t, args, complain, in_decl,
8606 /*integral_constant_expression_p=*/true);
8607 if (!(complain & tf_warning))
8608 --c_inhibit_evaluation_warnings;
8613 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
8614 NONTYPE_ARGUMENT_PACK. */
8617 make_fnparm_pack (tree spec_parm)
8619 /* Collect all of the extra "packed" parameters into an
8623 tree argpack = make_node (NONTYPE_ARGUMENT_PACK);
8624 tree argtypepack = cxx_make_type (TYPE_ARGUMENT_PACK);
8625 int i, len = list_length (spec_parm);
8627 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
8628 parmvec = make_tree_vec (len);
8629 parmtypevec = make_tree_vec (len);
8630 for (i = 0; i < len; i++, spec_parm = DECL_CHAIN (spec_parm))
8632 TREE_VEC_ELT (parmvec, i) = spec_parm;
8633 TREE_VEC_ELT (parmtypevec, i) = TREE_TYPE (spec_parm);
8636 /* Build the argument packs. */
8637 SET_ARGUMENT_PACK_ARGS (argpack, parmvec);
8638 SET_ARGUMENT_PACK_ARGS (argtypepack, parmtypevec);
8639 TREE_TYPE (argpack) = argtypepack;
8644 /* Substitute ARGS into T, which is an pack expansion
8645 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
8646 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
8647 (if only a partial substitution could be performed) or
8648 ERROR_MARK_NODE if there was an error. */
8650 tsubst_pack_expansion (tree t, tree args, tsubst_flags_t complain,
8654 tree pack, packs = NULL_TREE, unsubstituted_packs = NULL_TREE;
8658 htab_t saved_local_specializations = NULL;
8660 gcc_assert (PACK_EXPANSION_P (t));
8661 pattern = PACK_EXPANSION_PATTERN (t);
8663 /* Determine the argument packs that will instantiate the parameter
8664 packs used in the expansion expression. While we're at it,
8665 compute the number of arguments to be expanded and make sure it
8667 for (pack = PACK_EXPANSION_PARAMETER_PACKS (t); pack;
8668 pack = TREE_CHAIN (pack))
8670 tree parm_pack = TREE_VALUE (pack);
8671 tree arg_pack = NULL_TREE;
8672 tree orig_arg = NULL_TREE;
8674 if (TREE_CODE (parm_pack) == PARM_DECL)
8676 if (!cp_unevaluated_operand)
8677 arg_pack = retrieve_local_specialization (parm_pack);
8680 /* We can't rely on local_specializations for a parameter
8681 name used later in a function declaration (such as in a
8682 late-specified return type). Even if it exists, it might
8683 have the wrong value for a recursive call. Just make a
8684 dummy decl, since it's only used for its type. */
8685 arg_pack = tsubst_decl (parm_pack, args, complain);
8686 arg_pack = make_fnparm_pack (arg_pack);
8691 int level, idx, levels;
8692 template_parm_level_and_index (parm_pack, &level, &idx);
8694 levels = TMPL_ARGS_DEPTH (args);
8695 if (level <= levels)
8696 arg_pack = TMPL_ARG (args, level, idx);
8699 orig_arg = arg_pack;
8700 if (arg_pack && TREE_CODE (arg_pack) == ARGUMENT_PACK_SELECT)
8701 arg_pack = ARGUMENT_PACK_SELECT_FROM_PACK (arg_pack);
8703 if (arg_pack && !ARGUMENT_PACK_P (arg_pack))
8704 /* This can only happen if we forget to expand an argument
8705 pack somewhere else. Just return an error, silently. */
8707 result = make_tree_vec (1);
8708 TREE_VEC_ELT (result, 0) = error_mark_node;
8713 && TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack)) == 1
8714 && PACK_EXPANSION_P (TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0)))
8716 tree expansion = TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0);
8717 tree pattern = PACK_EXPANSION_PATTERN (expansion);
8718 if ((TYPE_P (pattern) && same_type_p (pattern, parm_pack))
8719 || (!TYPE_P (pattern) && cp_tree_equal (parm_pack, pattern)))
8720 /* The argument pack that the parameter maps to is just an
8721 expansion of the parameter itself, such as one would
8722 find in the implicit typedef of a class inside the
8723 class itself. Consider this parameter "unsubstituted",
8724 so that we will maintain the outer pack expansion. */
8725 arg_pack = NULL_TREE;
8731 TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack));
8733 /* It's all-or-nothing with incomplete argument packs. */
8734 if (incomplete && !ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
8735 return error_mark_node;
8737 if (ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
8742 else if (len != my_len)
8745 /* We got explicit args for some packs but not others;
8746 do nothing now and try again after deduction. */
8748 if (TREE_CODE (t) == TYPE_PACK_EXPANSION)
8749 error ("mismatched argument pack lengths while expanding "
8753 error ("mismatched argument pack lengths while expanding "
8756 return error_mark_node;
8759 /* Keep track of the parameter packs and their corresponding
8761 packs = tree_cons (parm_pack, arg_pack, packs);
8762 TREE_TYPE (packs) = orig_arg;
8765 /* We can't substitute for this parameter pack. */
8766 unsubstituted_packs = tree_cons (TREE_PURPOSE (pack),
8768 unsubstituted_packs);
8771 /* We cannot expand this expansion expression, because we don't have
8772 all of the argument packs we need. Substitute into the pattern
8773 and return a PACK_EXPANSION_*. The caller will need to deal with
8775 if (unsubstituted_packs)
8778 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
8779 new_pat = tsubst_expr (pattern, args, complain, in_decl,
8780 /*integral_constant_expression_p=*/false);
8782 new_pat = tsubst (pattern, args, complain, in_decl);
8783 return make_pack_expansion (new_pat);
8786 /* We could not find any argument packs that work. */
8788 return error_mark_node;
8790 if (cp_unevaluated_operand)
8792 /* We're in a late-specified return type, so create our own local
8793 specializations table; the current table is either NULL or (in the
8794 case of recursive unification) might have bindings that we don't
8795 want to use or alter. */
8796 saved_local_specializations = local_specializations;
8797 local_specializations = htab_create (37,
8798 hash_local_specialization,
8799 eq_local_specializations,
8803 /* For each argument in each argument pack, substitute into the
8805 result = make_tree_vec (len + incomplete);
8806 for (i = 0; i < len + incomplete; ++i)
8808 /* For parameter pack, change the substitution of the parameter
8809 pack to the ith argument in its argument pack, then expand
8811 for (pack = packs; pack; pack = TREE_CHAIN (pack))
8813 tree parm = TREE_PURPOSE (pack);
8815 if (TREE_CODE (parm) == PARM_DECL)
8817 /* Select the Ith argument from the pack. */
8818 tree arg = make_node (ARGUMENT_PACK_SELECT);
8819 ARGUMENT_PACK_SELECT_FROM_PACK (arg) = TREE_VALUE (pack);
8820 ARGUMENT_PACK_SELECT_INDEX (arg) = i;
8822 register_local_specialization (arg, parm);
8828 template_parm_level_and_index (parm, &level, &idx);
8832 /* Select the Ith argument from the pack. */
8833 value = make_node (ARGUMENT_PACK_SELECT);
8834 ARGUMENT_PACK_SELECT_FROM_PACK (value) = TREE_VALUE (pack);
8835 ARGUMENT_PACK_SELECT_INDEX (value) = i;
8838 /* Update the corresponding argument. */
8839 TMPL_ARG (args, level, idx) = value;
8843 /* Substitute into the PATTERN with the altered arguments. */
8844 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
8845 TREE_VEC_ELT (result, i) =
8846 tsubst_expr (pattern, args, complain, in_decl,
8847 /*integral_constant_expression_p=*/false);
8849 TREE_VEC_ELT (result, i) = tsubst (pattern, args, complain, in_decl);
8852 /* When we have incomplete argument packs, the last "expanded"
8853 result is itself a pack expansion, which allows us
8854 to deduce more arguments. */
8855 TREE_VEC_ELT (result, i) =
8856 make_pack_expansion (TREE_VEC_ELT (result, i));
8858 if (TREE_VEC_ELT (result, i) == error_mark_node)
8860 result = error_mark_node;
8865 /* Update ARGS to restore the substitution from parameter packs to
8866 their argument packs. */
8867 for (pack = packs; pack; pack = TREE_CHAIN (pack))
8869 tree parm = TREE_PURPOSE (pack);
8871 if (TREE_CODE (parm) == PARM_DECL)
8872 register_local_specialization (TREE_TYPE (pack), parm);
8876 template_parm_level_and_index (parm, &level, &idx);
8878 /* Update the corresponding argument. */
8879 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
8880 TREE_VEC_ELT (TREE_VEC_ELT (args, level -1 ), idx) =
8883 TREE_VEC_ELT (args, idx) = TREE_TYPE (pack);
8887 if (saved_local_specializations)
8889 htab_delete (local_specializations);
8890 local_specializations = saved_local_specializations;
8896 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
8897 TMPL. We do this using DECL_PARM_INDEX, which should work even with
8898 parameter packs; all parms generated from a function parameter pack will
8899 have the same DECL_PARM_INDEX. */
8902 get_pattern_parm (tree parm, tree tmpl)
8904 tree pattern = DECL_TEMPLATE_RESULT (tmpl);
8907 if (DECL_ARTIFICIAL (parm))
8909 for (patparm = DECL_ARGUMENTS (pattern);
8910 patparm; patparm = DECL_CHAIN (patparm))
8911 if (DECL_ARTIFICIAL (patparm)
8912 && DECL_NAME (parm) == DECL_NAME (patparm))
8917 patparm = FUNCTION_FIRST_USER_PARM (DECL_TEMPLATE_RESULT (tmpl));
8918 patparm = chain_index (DECL_PARM_INDEX (parm)-1, patparm);
8919 gcc_assert (DECL_PARM_INDEX (patparm)
8920 == DECL_PARM_INDEX (parm));
8926 /* Substitute ARGS into the vector or list of template arguments T. */
8929 tsubst_template_args (tree t, tree args, tsubst_flags_t complain, tree in_decl)
8932 int len = TREE_VEC_LENGTH (t);
8933 int need_new = 0, i, expanded_len_adjust = 0, out;
8934 tree *elts = XALLOCAVEC (tree, len);
8936 for (i = 0; i < len; i++)
8938 tree orig_arg = TREE_VEC_ELT (t, i);
8941 if (TREE_CODE (orig_arg) == TREE_VEC)
8942 new_arg = tsubst_template_args (orig_arg, args, complain, in_decl);
8943 else if (PACK_EXPANSION_P (orig_arg))
8945 /* Substitute into an expansion expression. */
8946 new_arg = tsubst_pack_expansion (orig_arg, args, complain, in_decl);
8948 if (TREE_CODE (new_arg) == TREE_VEC)
8949 /* Add to the expanded length adjustment the number of
8950 expanded arguments. We subtract one from this
8951 measurement, because the argument pack expression
8952 itself is already counted as 1 in
8953 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
8954 the argument pack is empty. */
8955 expanded_len_adjust += TREE_VEC_LENGTH (new_arg) - 1;
8957 else if (ARGUMENT_PACK_P (orig_arg))
8959 /* Substitute into each of the arguments. */
8960 new_arg = TYPE_P (orig_arg)
8961 ? cxx_make_type (TREE_CODE (orig_arg))
8962 : make_node (TREE_CODE (orig_arg));
8964 SET_ARGUMENT_PACK_ARGS (
8966 tsubst_template_args (ARGUMENT_PACK_ARGS (orig_arg),
8967 args, complain, in_decl));
8969 if (ARGUMENT_PACK_ARGS (new_arg) == error_mark_node)
8970 new_arg = error_mark_node;
8972 if (TREE_CODE (new_arg) == NONTYPE_ARGUMENT_PACK) {
8973 TREE_TYPE (new_arg) = tsubst (TREE_TYPE (orig_arg), args,
8975 TREE_CONSTANT (new_arg) = TREE_CONSTANT (orig_arg);
8977 if (TREE_TYPE (new_arg) == error_mark_node)
8978 new_arg = error_mark_node;
8982 new_arg = tsubst_template_arg (orig_arg, args, complain, in_decl);
8984 if (new_arg == error_mark_node)
8985 return error_mark_node;
8988 if (new_arg != orig_arg)
8995 /* Make space for the expanded arguments coming from template
8997 t = make_tree_vec (len + expanded_len_adjust);
8998 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
8999 arguments for a member template.
9000 In that case each TREE_VEC in ORIG_T represents a level of template
9001 arguments, and ORIG_T won't carry any non defaulted argument count.
9002 It will rather be the nested TREE_VECs that will carry one.
9003 In other words, ORIG_T carries a non defaulted argument count only
9004 if it doesn't contain any nested TREE_VEC. */
9005 if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t))
9007 int count = GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t);
9008 count += expanded_len_adjust;
9009 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (t, count);
9011 for (i = 0, out = 0; i < len; i++)
9013 if ((PACK_EXPANSION_P (TREE_VEC_ELT (orig_t, i))
9014 || ARGUMENT_PACK_P (TREE_VEC_ELT (orig_t, i)))
9015 && TREE_CODE (elts[i]) == TREE_VEC)
9019 /* Now expand the template argument pack "in place". */
9020 for (idx = 0; idx < TREE_VEC_LENGTH (elts[i]); idx++, out++)
9021 TREE_VEC_ELT (t, out) = TREE_VEC_ELT (elts[i], idx);
9025 TREE_VEC_ELT (t, out) = elts[i];
9033 /* Return the result of substituting ARGS into the template parameters
9034 given by PARMS. If there are m levels of ARGS and m + n levels of
9035 PARMS, then the result will contain n levels of PARMS. For
9036 example, if PARMS is `template <class T> template <class U>
9037 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
9038 result will be `template <int*, double, class V>'. */
9041 tsubst_template_parms (tree parms, tree args, tsubst_flags_t complain)
9046 /* When substituting into a template, we must set
9047 PROCESSING_TEMPLATE_DECL as the template parameters may be
9048 dependent if they are based on one-another, and the dependency
9049 predicates are short-circuit outside of templates. */
9050 ++processing_template_decl;
9052 for (new_parms = &r;
9053 TMPL_PARMS_DEPTH (parms) > TMPL_ARGS_DEPTH (args);
9054 new_parms = &(TREE_CHAIN (*new_parms)),
9055 parms = TREE_CHAIN (parms))
9058 make_tree_vec (TREE_VEC_LENGTH (TREE_VALUE (parms)));
9061 for (i = 0; i < TREE_VEC_LENGTH (new_vec); ++i)
9065 if (parms == error_mark_node)
9068 tuple = TREE_VEC_ELT (TREE_VALUE (parms), i);
9070 if (tuple == error_mark_node)
9073 TREE_VEC_ELT (new_vec, i) =
9074 tsubst_template_parm (tuple, args, complain);
9078 tree_cons (size_int (TMPL_PARMS_DEPTH (parms)
9079 - TMPL_ARGS_DEPTH (args)),
9080 new_vec, NULL_TREE);
9083 --processing_template_decl;
9088 /* Return the result of substituting ARGS into one template parameter
9089 given by T. T Must be a TREE_LIST which TREE_VALUE is the template
9090 parameter and which TREE_PURPOSE is the default argument of the
9091 template parameter. */
9094 tsubst_template_parm (tree t, tree args, tsubst_flags_t complain)
9096 tree default_value, parm_decl;
9098 if (args == NULL_TREE
9100 || t == error_mark_node)
9103 gcc_assert (TREE_CODE (t) == TREE_LIST);
9105 default_value = TREE_PURPOSE (t);
9106 parm_decl = TREE_VALUE (t);
9108 parm_decl = tsubst (parm_decl, args, complain, NULL_TREE);
9109 if (TREE_CODE (parm_decl) == PARM_DECL
9110 && invalid_nontype_parm_type_p (TREE_TYPE (parm_decl), complain))
9111 parm_decl = error_mark_node;
9112 default_value = tsubst_template_arg (default_value, args,
9113 complain, NULL_TREE);
9115 return build_tree_list (default_value, parm_decl);
9118 /* Substitute the ARGS into the indicated aggregate (or enumeration)
9119 type T. If T is not an aggregate or enumeration type, it is
9120 handled as if by tsubst. IN_DECL is as for tsubst. If
9121 ENTERING_SCOPE is nonzero, T is the context for a template which
9122 we are presently tsubst'ing. Return the substituted value. */
9125 tsubst_aggr_type (tree t,
9127 tsubst_flags_t complain,
9134 switch (TREE_CODE (t))
9137 if (TYPE_PTRMEMFUNC_P (t))
9138 return tsubst (TYPE_PTRMEMFUNC_FN_TYPE (t), args, complain, in_decl);
9140 /* Else fall through. */
9143 if (TYPE_TEMPLATE_INFO (t) && uses_template_parms (t))
9148 int saved_unevaluated_operand;
9149 int saved_inhibit_evaluation_warnings;
9151 /* In "sizeof(X<I>)" we need to evaluate "I". */
9152 saved_unevaluated_operand = cp_unevaluated_operand;
9153 cp_unevaluated_operand = 0;
9154 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
9155 c_inhibit_evaluation_warnings = 0;
9157 /* First, determine the context for the type we are looking
9159 context = TYPE_CONTEXT (t);
9162 context = tsubst_aggr_type (context, args, complain,
9163 in_decl, /*entering_scope=*/1);
9164 /* If context is a nested class inside a class template,
9165 it may still need to be instantiated (c++/33959). */
9166 if (TYPE_P (context))
9167 context = complete_type (context);
9170 /* Then, figure out what arguments are appropriate for the
9171 type we are trying to find. For example, given:
9173 template <class T> struct S;
9174 template <class T, class U> void f(T, U) { S<U> su; }
9176 and supposing that we are instantiating f<int, double>,
9177 then our ARGS will be {int, double}, but, when looking up
9178 S we only want {double}. */
9179 argvec = tsubst_template_args (TYPE_TI_ARGS (t), args,
9181 if (argvec == error_mark_node)
9182 r = error_mark_node;
9185 r = lookup_template_class (t, argvec, in_decl, context,
9186 entering_scope, complain);
9187 r = cp_build_qualified_type_real (r, cp_type_quals (t), complain);
9190 cp_unevaluated_operand = saved_unevaluated_operand;
9191 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
9196 /* This is not a template type, so there's nothing to do. */
9200 return tsubst (t, args, complain, in_decl);
9204 /* Substitute into the default argument ARG (a default argument for
9205 FN), which has the indicated TYPE. */
9208 tsubst_default_argument (tree fn, tree type, tree arg)
9210 tree saved_class_ptr = NULL_TREE;
9211 tree saved_class_ref = NULL_TREE;
9213 /* This can happen in invalid code. */
9214 if (TREE_CODE (arg) == DEFAULT_ARG)
9217 /* This default argument came from a template. Instantiate the
9218 default argument here, not in tsubst. In the case of
9227 we must be careful to do name lookup in the scope of S<T>,
9228 rather than in the current class. */
9229 push_access_scope (fn);
9230 /* The "this" pointer is not valid in a default argument. */
9233 saved_class_ptr = current_class_ptr;
9234 cp_function_chain->x_current_class_ptr = NULL_TREE;
9235 saved_class_ref = current_class_ref;
9236 cp_function_chain->x_current_class_ref = NULL_TREE;
9239 push_deferring_access_checks(dk_no_deferred);
9240 /* The default argument expression may cause implicitly defined
9241 member functions to be synthesized, which will result in garbage
9242 collection. We must treat this situation as if we were within
9243 the body of function so as to avoid collecting live data on the
9246 arg = tsubst_expr (arg, DECL_TI_ARGS (fn),
9247 tf_warning_or_error, NULL_TREE,
9248 /*integral_constant_expression_p=*/false);
9250 pop_deferring_access_checks();
9252 /* Restore the "this" pointer. */
9255 cp_function_chain->x_current_class_ptr = saved_class_ptr;
9256 cp_function_chain->x_current_class_ref = saved_class_ref;
9259 /* Make sure the default argument is reasonable. */
9260 arg = check_default_argument (type, arg);
9262 pop_access_scope (fn);
9267 /* Substitute into all the default arguments for FN. */
9270 tsubst_default_arguments (tree fn)
9275 tmpl_args = DECL_TI_ARGS (fn);
9277 /* If this function is not yet instantiated, we certainly don't need
9278 its default arguments. */
9279 if (uses_template_parms (tmpl_args))
9281 /* Don't do this again for clones. */
9282 if (DECL_CLONED_FUNCTION_P (fn))
9285 for (arg = TYPE_ARG_TYPES (TREE_TYPE (fn));
9287 arg = TREE_CHAIN (arg))
9288 if (TREE_PURPOSE (arg))
9289 TREE_PURPOSE (arg) = tsubst_default_argument (fn,
9291 TREE_PURPOSE (arg));
9294 /* Substitute the ARGS into the T, which is a _DECL. Return the
9295 result of the substitution. Issue error and warning messages under
9296 control of COMPLAIN. */
9299 tsubst_decl (tree t, tree args, tsubst_flags_t complain)
9301 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
9302 location_t saved_loc;
9307 /* Set the filename and linenumber to improve error-reporting. */
9308 saved_loc = input_location;
9309 input_location = DECL_SOURCE_LOCATION (t);
9311 switch (TREE_CODE (t))
9315 /* We can get here when processing a member function template,
9316 member class template, or template template parameter. */
9317 tree decl = DECL_TEMPLATE_RESULT (t);
9322 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
9324 /* Template template parameter is treated here. */
9325 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9326 if (new_type == error_mark_node)
9327 RETURN (error_mark_node);
9330 DECL_CHAIN (r) = NULL_TREE;
9331 TREE_TYPE (r) = new_type;
9332 DECL_TEMPLATE_RESULT (r)
9333 = build_decl (DECL_SOURCE_LOCATION (decl),
9334 TYPE_DECL, DECL_NAME (decl), new_type);
9335 DECL_TEMPLATE_PARMS (r)
9336 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
9338 TYPE_NAME (new_type) = r;
9342 /* We might already have an instance of this template.
9343 The ARGS are for the surrounding class type, so the
9344 full args contain the tsubst'd args for the context,
9345 plus the innermost args from the template decl. */
9346 tmpl_args = DECL_CLASS_TEMPLATE_P (t)
9347 ? CLASSTYPE_TI_ARGS (TREE_TYPE (t))
9348 : DECL_TI_ARGS (DECL_TEMPLATE_RESULT (t));
9349 /* Because this is a template, the arguments will still be
9350 dependent, even after substitution. If
9351 PROCESSING_TEMPLATE_DECL is not set, the dependency
9352 predicates will short-circuit. */
9353 ++processing_template_decl;
9354 full_args = tsubst_template_args (tmpl_args, args,
9356 --processing_template_decl;
9357 if (full_args == error_mark_node)
9358 RETURN (error_mark_node);
9360 /* If this is a default template template argument,
9361 tsubst might not have changed anything. */
9362 if (full_args == tmpl_args)
9365 hash = hash_tmpl_and_args (t, full_args);
9366 spec = retrieve_specialization (t, full_args, hash);
9367 if (spec != NULL_TREE)
9373 /* Make a new template decl. It will be similar to the
9374 original, but will record the current template arguments.
9375 We also create a new function declaration, which is just
9376 like the old one, but points to this new template, rather
9377 than the old one. */
9379 gcc_assert (DECL_LANG_SPECIFIC (r) != 0);
9380 DECL_CHAIN (r) = NULL_TREE;
9382 DECL_TEMPLATE_INFO (r) = build_template_info (t, args);
9384 if (TREE_CODE (decl) == TYPE_DECL)
9387 ++processing_template_decl;
9388 new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9389 --processing_template_decl;
9390 if (new_type == error_mark_node)
9391 RETURN (error_mark_node);
9393 TREE_TYPE (r) = new_type;
9394 CLASSTYPE_TI_TEMPLATE (new_type) = r;
9395 DECL_TEMPLATE_RESULT (r) = TYPE_MAIN_DECL (new_type);
9396 DECL_TI_ARGS (r) = CLASSTYPE_TI_ARGS (new_type);
9397 DECL_CONTEXT (r) = TYPE_CONTEXT (new_type);
9402 ++processing_template_decl;
9403 new_decl = tsubst (decl, args, complain, in_decl);
9404 --processing_template_decl;
9405 if (new_decl == error_mark_node)
9406 RETURN (error_mark_node);
9408 DECL_TEMPLATE_RESULT (r) = new_decl;
9409 DECL_TI_TEMPLATE (new_decl) = r;
9410 TREE_TYPE (r) = TREE_TYPE (new_decl);
9411 DECL_TI_ARGS (r) = DECL_TI_ARGS (new_decl);
9412 DECL_CONTEXT (r) = DECL_CONTEXT (new_decl);
9415 SET_DECL_IMPLICIT_INSTANTIATION (r);
9416 DECL_TEMPLATE_INSTANTIATIONS (r) = NULL_TREE;
9417 DECL_TEMPLATE_SPECIALIZATIONS (r) = NULL_TREE;
9419 /* The template parameters for this new template are all the
9420 template parameters for the old template, except the
9421 outermost level of parameters. */
9422 DECL_TEMPLATE_PARMS (r)
9423 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
9426 if (PRIMARY_TEMPLATE_P (t))
9427 DECL_PRIMARY_TEMPLATE (r) = r;
9429 if (TREE_CODE (decl) != TYPE_DECL)
9430 /* Record this non-type partial instantiation. */
9431 register_specialization (r, t,
9432 DECL_TI_ARGS (DECL_TEMPLATE_RESULT (r)),
9440 tree argvec = NULL_TREE;
9448 /* Nobody should be tsubst'ing into non-template functions. */
9449 gcc_assert (DECL_TEMPLATE_INFO (t) != NULL_TREE);
9451 if (TREE_CODE (DECL_TI_TEMPLATE (t)) == TEMPLATE_DECL)
9456 /* If T is not dependent, just return it. We have to
9457 increment PROCESSING_TEMPLATE_DECL because
9458 value_dependent_expression_p assumes that nothing is
9459 dependent when PROCESSING_TEMPLATE_DECL is zero. */
9460 ++processing_template_decl;
9461 dependent_p = value_dependent_expression_p (t);
9462 --processing_template_decl;
9466 /* Calculate the most general template of which R is a
9467 specialization, and the complete set of arguments used to
9469 gen_tmpl = most_general_template (DECL_TI_TEMPLATE (t));
9470 argvec = tsubst_template_args (DECL_TI_ARGS
9471 (DECL_TEMPLATE_RESULT
9472 (DECL_TI_TEMPLATE (t))),
9473 args, complain, in_decl);
9475 /* Check to see if we already have this specialization. */
9476 hash = hash_tmpl_and_args (gen_tmpl, argvec);
9477 spec = retrieve_specialization (gen_tmpl, argvec, hash);
9485 /* We can see more levels of arguments than parameters if
9486 there was a specialization of a member template, like
9489 template <class T> struct S { template <class U> void f(); }
9490 template <> template <class U> void S<int>::f(U);
9492 Here, we'll be substituting into the specialization,
9493 because that's where we can find the code we actually
9494 want to generate, but we'll have enough arguments for
9495 the most general template.
9497 We also deal with the peculiar case:
9499 template <class T> struct S {
9500 template <class U> friend void f();
9502 template <class U> void f() {}
9504 template void f<double>();
9506 Here, the ARGS for the instantiation of will be {int,
9507 double}. But, we only need as many ARGS as there are
9508 levels of template parameters in CODE_PATTERN. We are
9509 careful not to get fooled into reducing the ARGS in
9512 template <class T> struct S { template <class U> void f(U); }
9513 template <class T> template <> void S<T>::f(int) {}
9515 which we can spot because the pattern will be a
9516 specialization in this case. */
9517 args_depth = TMPL_ARGS_DEPTH (args);
9519 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (t)));
9520 if (args_depth > parms_depth
9521 && !DECL_TEMPLATE_SPECIALIZATION (t))
9522 args = get_innermost_template_args (args, parms_depth);
9526 /* This special case arises when we have something like this:
9528 template <class T> struct S {
9529 friend void f<int>(int, double);
9532 Here, the DECL_TI_TEMPLATE for the friend declaration
9533 will be an IDENTIFIER_NODE. We are being called from
9534 tsubst_friend_function, and we want only to create a
9535 new decl (R) with appropriate types so that we can call
9536 determine_specialization. */
9537 gen_tmpl = NULL_TREE;
9540 if (DECL_CLASS_SCOPE_P (t))
9542 if (DECL_NAME (t) == constructor_name (DECL_CONTEXT (t)))
9546 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args,
9547 complain, t, /*entering_scope=*/1);
9552 ctx = DECL_CONTEXT (t);
9554 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9555 if (type == error_mark_node)
9556 RETURN (error_mark_node);
9558 /* We do NOT check for matching decls pushed separately at this
9559 point, as they may not represent instantiations of this
9560 template, and in any case are considered separate under the
9563 DECL_USE_TEMPLATE (r) = 0;
9564 TREE_TYPE (r) = type;
9565 /* Clear out the mangled name and RTL for the instantiation. */
9566 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
9567 SET_DECL_RTL (r, NULL);
9568 /* Leave DECL_INITIAL set on deleted instantiations. */
9569 if (!DECL_DELETED_FN (r))
9570 DECL_INITIAL (r) = NULL_TREE;
9571 DECL_CONTEXT (r) = ctx;
9573 if (member && DECL_CONV_FN_P (r))
9574 /* Type-conversion operator. Reconstruct the name, in
9575 case it's the name of one of the template's parameters. */
9576 DECL_NAME (r) = mangle_conv_op_name_for_type (TREE_TYPE (type));
9578 DECL_ARGUMENTS (r) = tsubst (DECL_ARGUMENTS (t), args,
9580 DECL_RESULT (r) = NULL_TREE;
9582 TREE_STATIC (r) = 0;
9583 TREE_PUBLIC (r) = TREE_PUBLIC (t);
9584 DECL_EXTERNAL (r) = 1;
9585 /* If this is an instantiation of a function with internal
9586 linkage, we already know what object file linkage will be
9587 assigned to the instantiation. */
9588 DECL_INTERFACE_KNOWN (r) = !TREE_PUBLIC (r);
9589 DECL_DEFER_OUTPUT (r) = 0;
9590 DECL_CHAIN (r) = NULL_TREE;
9591 DECL_PENDING_INLINE_INFO (r) = 0;
9592 DECL_PENDING_INLINE_P (r) = 0;
9593 DECL_SAVED_TREE (r) = NULL_TREE;
9594 DECL_STRUCT_FUNCTION (r) = NULL;
9596 /* We'll re-clone as appropriate in instantiate_template. */
9597 DECL_CLONED_FUNCTION (r) = NULL_TREE;
9599 /* If we aren't complaining now, return on error before we register
9600 the specialization so that we'll complain eventually. */
9601 if ((complain & tf_error) == 0
9602 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
9603 && !grok_op_properties (r, /*complain=*/false))
9604 RETURN (error_mark_node);
9606 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
9607 this in the special friend case mentioned above where
9608 GEN_TMPL is NULL. */
9611 DECL_TEMPLATE_INFO (r)
9612 = build_template_info (gen_tmpl, argvec);
9613 SET_DECL_IMPLICIT_INSTANTIATION (r);
9614 register_specialization (r, gen_tmpl, argvec, false, hash);
9616 /* We're not supposed to instantiate default arguments
9617 until they are called, for a template. But, for a
9620 template <class T> void f ()
9621 { extern void g(int i = T()); }
9623 we should do the substitution when the template is
9624 instantiated. We handle the member function case in
9625 instantiate_class_template since the default arguments
9626 might refer to other members of the class. */
9628 && !PRIMARY_TEMPLATE_P (gen_tmpl)
9629 && !uses_template_parms (argvec))
9630 tsubst_default_arguments (r);
9633 DECL_TEMPLATE_INFO (r) = NULL_TREE;
9635 /* Copy the list of befriending classes. */
9636 for (friends = &DECL_BEFRIENDING_CLASSES (r);
9638 friends = &TREE_CHAIN (*friends))
9640 *friends = copy_node (*friends);
9641 TREE_VALUE (*friends) = tsubst (TREE_VALUE (*friends),
9646 if (DECL_CONSTRUCTOR_P (r) || DECL_DESTRUCTOR_P (r))
9648 maybe_retrofit_in_chrg (r);
9649 if (DECL_CONSTRUCTOR_P (r))
9650 grok_ctor_properties (ctx, r);
9651 /* If this is an instantiation of a member template, clone it.
9652 If it isn't, that'll be handled by
9653 clone_constructors_and_destructors. */
9654 if (PRIMARY_TEMPLATE_P (gen_tmpl))
9655 clone_function_decl (r, /*update_method_vec_p=*/0);
9657 else if ((complain & tf_error) != 0
9658 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
9659 && !grok_op_properties (r, /*complain=*/true))
9660 RETURN (error_mark_node);
9662 if (DECL_FRIEND_P (t) && DECL_FRIEND_CONTEXT (t))
9663 SET_DECL_FRIEND_CONTEXT (r,
9664 tsubst (DECL_FRIEND_CONTEXT (t),
9665 args, complain, in_decl));
9667 /* Possibly limit visibility based on template args. */
9668 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
9669 if (DECL_VISIBILITY_SPECIFIED (t))
9671 DECL_VISIBILITY_SPECIFIED (r) = 0;
9673 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
9675 determine_visibility (r);
9676 if (DECL_DEFAULTED_OUTSIDE_CLASS_P (r)
9677 && !processing_template_decl)
9678 defaulted_late_check (r);
9680 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
9681 args, complain, in_decl);
9687 tree type = NULL_TREE;
9689 tree expanded_types = NULL_TREE;
9690 tree prev_r = NULL_TREE;
9691 tree first_r = NULL_TREE;
9693 if (FUNCTION_PARAMETER_PACK_P (t))
9695 /* If there is a local specialization that isn't a
9696 parameter pack, it means that we're doing a "simple"
9697 substitution from inside tsubst_pack_expansion. Just
9698 return the local specialization (which will be a single
9700 tree spec = retrieve_local_specialization (t);
9702 && TREE_CODE (spec) == PARM_DECL
9703 && TREE_CODE (TREE_TYPE (spec)) != TYPE_PACK_EXPANSION)
9706 /* Expand the TYPE_PACK_EXPANSION that provides the types for
9707 the parameters in this function parameter pack. */
9708 expanded_types = tsubst_pack_expansion (TREE_TYPE (t), args,
9710 if (TREE_CODE (expanded_types) == TREE_VEC)
9712 len = TREE_VEC_LENGTH (expanded_types);
9714 /* Zero-length parameter packs are boring. Just substitute
9717 RETURN (tsubst (TREE_CHAIN (t), args, complain,
9722 /* All we did was update the type. Make a note of that. */
9723 type = expanded_types;
9724 expanded_types = NULL_TREE;
9728 /* Loop through all of the parameter's we'll build. When T is
9729 a function parameter pack, LEN is the number of expanded
9730 types in EXPANDED_TYPES; otherwise, LEN is 1. */
9732 for (i = 0; i < len; ++i)
9736 if (DECL_TEMPLATE_PARM_P (t))
9737 SET_DECL_TEMPLATE_PARM_P (r);
9739 /* An argument of a function parameter pack is not a parameter
9741 FUNCTION_PARAMETER_PACK_P (r) = false;
9744 /* We're on the Ith parameter of the function parameter
9747 /* Get the Ith type. */
9748 type = TREE_VEC_ELT (expanded_types, i);
9751 /* Rename the parameter to include the index. */
9753 make_ith_pack_parameter_name (DECL_NAME (r), i);
9756 /* We're dealing with a normal parameter. */
9757 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9759 type = type_decays_to (type);
9760 TREE_TYPE (r) = type;
9761 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
9763 if (DECL_INITIAL (r))
9765 if (TREE_CODE (DECL_INITIAL (r)) != TEMPLATE_PARM_INDEX)
9766 DECL_INITIAL (r) = TREE_TYPE (r);
9768 DECL_INITIAL (r) = tsubst (DECL_INITIAL (r), args,
9772 DECL_CONTEXT (r) = NULL_TREE;
9774 if (!DECL_TEMPLATE_PARM_P (r))
9775 DECL_ARG_TYPE (r) = type_passed_as (type);
9777 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
9778 args, complain, in_decl);
9780 /* Keep track of the first new parameter we
9781 generate. That's what will be returned to the
9786 /* Build a proper chain of parameters when substituting
9787 into a function parameter pack. */
9789 DECL_CHAIN (prev_r) = r;
9793 DECL_CHAIN (r) = tsubst (DECL_CHAIN (t), args,
9794 complain, DECL_CHAIN (t));
9796 /* FIRST_R contains the start of the chain we've built. */
9806 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9807 if (type == error_mark_node)
9808 RETURN (error_mark_node);
9809 TREE_TYPE (r) = type;
9810 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
9812 /* DECL_INITIAL gives the number of bits in a bit-field. */
9814 = tsubst_expr (DECL_INITIAL (t), args,
9816 /*integral_constant_expression_p=*/true);
9817 /* We don't have to set DECL_CONTEXT here; it is set by
9818 finish_member_declaration. */
9819 DECL_CHAIN (r) = NULL_TREE;
9820 if (VOID_TYPE_P (type))
9821 error ("instantiation of %q+D as type %qT", r, type);
9823 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
9824 args, complain, in_decl);
9829 /* We reach here only for member using decls. */
9830 if (DECL_DEPENDENT_P (t))
9832 r = do_class_using_decl
9833 (tsubst_copy (USING_DECL_SCOPE (t), args, complain, in_decl),
9834 tsubst_copy (DECL_NAME (t), args, complain, in_decl));
9836 r = error_mark_node;
9839 TREE_PROTECTED (r) = TREE_PROTECTED (t);
9840 TREE_PRIVATE (r) = TREE_PRIVATE (t);
9846 DECL_CHAIN (r) = NULL_TREE;
9853 tree argvec = NULL_TREE;
9854 tree gen_tmpl = NULL_TREE;
9856 tree tmpl = NULL_TREE;
9858 tree type = NULL_TREE;
9861 if (TREE_CODE (t) == TYPE_DECL
9862 && t == TYPE_MAIN_DECL (TREE_TYPE (t)))
9864 /* If this is the canonical decl, we don't have to
9865 mess with instantiations, and often we can't (for
9866 typename, template type parms and such). Note that
9867 TYPE_NAME is not correct for the above test if
9868 we've copied the type for a typedef. */
9869 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9870 if (type == error_mark_node)
9871 RETURN (error_mark_node);
9872 r = TYPE_NAME (type);
9876 /* Check to see if we already have the specialization we
9879 if (DECL_CLASS_SCOPE_P (t) || DECL_NAMESPACE_SCOPE_P (t))
9881 /* T is a static data member or namespace-scope entity.
9882 We have to substitute into namespace-scope variables
9883 (even though such entities are never templates) because
9886 template <class T> void f() { extern T t; }
9888 where the entity referenced is not known until
9889 instantiation time. */
9891 ctx = DECL_CONTEXT (t);
9892 if (DECL_CLASS_SCOPE_P (t))
9894 ctx = tsubst_aggr_type (ctx, args,
9896 in_decl, /*entering_scope=*/1);
9897 /* If CTX is unchanged, then T is in fact the
9898 specialization we want. That situation occurs when
9899 referencing a static data member within in its own
9900 class. We can use pointer equality, rather than
9901 same_type_p, because DECL_CONTEXT is always
9903 if (ctx == DECL_CONTEXT (t))
9909 tmpl = DECL_TI_TEMPLATE (t);
9910 gen_tmpl = most_general_template (tmpl);
9911 argvec = tsubst (DECL_TI_ARGS (t), args, complain, in_decl);
9912 hash = hash_tmpl_and_args (gen_tmpl, argvec);
9913 spec = retrieve_specialization (gen_tmpl, argvec, hash);
9918 /* A local variable. */
9920 /* Subsequent calls to pushdecl will fill this in. */
9922 spec = retrieve_local_specialization (t);
9924 /* If we already have the specialization we need, there is
9925 nothing more to do. */
9932 /* Create a new node for the specialization we need. */
9934 if (type == NULL_TREE)
9936 if (is_typedef_decl (t))
9937 type = DECL_ORIGINAL_TYPE (t);
9939 type = TREE_TYPE (t);
9940 if (TREE_CODE (t) == VAR_DECL && VAR_HAD_UNKNOWN_BOUND (t))
9941 type = strip_array_domain (type);
9942 type = tsubst (type, args, complain, in_decl);
9944 if (TREE_CODE (r) == VAR_DECL)
9946 /* Even if the original location is out of scope, the
9947 newly substituted one is not. */
9948 DECL_DEAD_FOR_LOCAL (r) = 0;
9949 DECL_INITIALIZED_P (r) = 0;
9950 DECL_TEMPLATE_INSTANTIATED (r) = 0;
9951 if (type == error_mark_node)
9952 RETURN (error_mark_node);
9953 if (TREE_CODE (type) == FUNCTION_TYPE)
9955 /* It may seem that this case cannot occur, since:
9960 declares a function, not a variable. However:
9963 template <typename T> void g() { T t; }
9964 template void g<f>();
9966 is an attempt to declare a variable with function
9968 error ("variable %qD has function type",
9969 /* R is not yet sufficiently initialized, so we
9970 just use its name. */
9972 RETURN (error_mark_node);
9974 type = complete_type (type);
9975 /* Wait until cp_finish_decl to set this again, to handle
9976 circular dependency (template/instantiate6.C). */
9977 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r) = 0;
9978 type = check_var_type (DECL_NAME (r), type);
9980 if (DECL_HAS_VALUE_EXPR_P (t))
9982 tree ve = DECL_VALUE_EXPR (t);
9983 ve = tsubst_expr (ve, args, complain, in_decl,
9984 /*constant_expression_p=*/false);
9985 SET_DECL_VALUE_EXPR (r, ve);
9988 else if (DECL_SELF_REFERENCE_P (t))
9989 SET_DECL_SELF_REFERENCE_P (r);
9990 TREE_TYPE (r) = type;
9991 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
9992 DECL_CONTEXT (r) = ctx;
9993 /* Clear out the mangled name and RTL for the instantiation. */
9994 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
9995 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
9996 SET_DECL_RTL (r, NULL);
9997 /* The initializer must not be expanded until it is required;
9999 DECL_INITIAL (r) = NULL_TREE;
10000 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
10001 SET_DECL_RTL (r, NULL);
10002 DECL_SIZE (r) = DECL_SIZE_UNIT (r) = 0;
10003 if (TREE_CODE (r) == VAR_DECL)
10005 /* Possibly limit visibility based on template args. */
10006 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
10007 if (DECL_VISIBILITY_SPECIFIED (t))
10009 DECL_VISIBILITY_SPECIFIED (r) = 0;
10010 DECL_ATTRIBUTES (r)
10011 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
10013 determine_visibility (r);
10018 /* A static data member declaration is always marked
10019 external when it is declared in-class, even if an
10020 initializer is present. We mimic the non-template
10021 processing here. */
10022 DECL_EXTERNAL (r) = 1;
10024 register_specialization (r, gen_tmpl, argvec, false, hash);
10025 DECL_TEMPLATE_INFO (r) = build_template_info (tmpl, argvec);
10026 SET_DECL_IMPLICIT_INSTANTIATION (r);
10028 else if (cp_unevaluated_operand)
10030 /* We're substituting this var in a decltype outside of its
10031 scope, such as for a lambda return type. Don't add it to
10032 local_specializations, do perform auto deduction. */
10033 tree auto_node = type_uses_auto (type);
10035 = tsubst_expr (DECL_INITIAL (t), args, complain, in_decl,
10036 /*constant_expression_p=*/false);
10038 if (auto_node && init)
10040 init = resolve_nondeduced_context (init);
10041 if (describable_type (init))
10043 type = do_auto_deduction (type, init, auto_node);
10044 TREE_TYPE (r) = type;
10049 register_local_specialization (r, t);
10051 DECL_CHAIN (r) = NULL_TREE;
10053 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r),
10055 args, complain, in_decl);
10057 /* Preserve a typedef that names a type. */
10058 if (is_typedef_decl (r))
10060 DECL_ORIGINAL_TYPE (r) = NULL_TREE;
10061 set_underlying_type (r);
10064 layout_decl (r, 0);
10069 gcc_unreachable ();
10074 /* Restore the file and line information. */
10075 input_location = saved_loc;
10080 /* Substitute into the ARG_TYPES of a function type. */
10083 tsubst_arg_types (tree arg_types,
10085 tsubst_flags_t complain,
10088 tree remaining_arg_types;
10089 tree type = NULL_TREE;
10091 tree expanded_args = NULL_TREE;
10094 if (!arg_types || arg_types == void_list_node)
10097 remaining_arg_types = tsubst_arg_types (TREE_CHAIN (arg_types),
10098 args, complain, in_decl);
10099 if (remaining_arg_types == error_mark_node)
10100 return error_mark_node;
10102 if (PACK_EXPANSION_P (TREE_VALUE (arg_types)))
10104 /* For a pack expansion, perform substitution on the
10105 entire expression. Later on, we'll handle the arguments
10107 expanded_args = tsubst_pack_expansion (TREE_VALUE (arg_types),
10108 args, complain, in_decl);
10110 if (TREE_CODE (expanded_args) == TREE_VEC)
10111 /* So that we'll spin through the parameters, one by one. */
10112 i = TREE_VEC_LENGTH (expanded_args);
10115 /* We only partially substituted into the parameter
10116 pack. Our type is TYPE_PACK_EXPANSION. */
10117 type = expanded_args;
10118 expanded_args = NULL_TREE;
10126 type = TREE_VEC_ELT (expanded_args, i);
10128 type = tsubst (TREE_VALUE (arg_types), args, complain, in_decl);
10130 if (type == error_mark_node)
10131 return error_mark_node;
10132 if (VOID_TYPE_P (type))
10134 if (complain & tf_error)
10136 error ("invalid parameter type %qT", type);
10138 error ("in declaration %q+D", in_decl);
10140 return error_mark_node;
10143 /* Do array-to-pointer, function-to-pointer conversion, and ignore
10144 top-level qualifiers as required. */
10145 type = TYPE_MAIN_VARIANT (type_decays_to (type));
10147 /* We do not substitute into default arguments here. The standard
10148 mandates that they be instantiated only when needed, which is
10149 done in build_over_call. */
10150 default_arg = TREE_PURPOSE (arg_types);
10152 if (default_arg && TREE_CODE (default_arg) == DEFAULT_ARG)
10154 /* We've instantiated a template before its default arguments
10155 have been parsed. This can happen for a nested template
10156 class, and is not an error unless we require the default
10157 argument in a call of this function. */
10158 remaining_arg_types =
10159 tree_cons (default_arg, type, remaining_arg_types);
10160 VEC_safe_push (tree, gc, DEFARG_INSTANTIATIONS (default_arg),
10161 remaining_arg_types);
10164 remaining_arg_types =
10165 hash_tree_cons (default_arg, type, remaining_arg_types);
10168 return remaining_arg_types;
10171 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
10172 *not* handle the exception-specification for FNTYPE, because the
10173 initial substitution of explicitly provided template parameters
10174 during argument deduction forbids substitution into the
10175 exception-specification:
10179 All references in the function type of the function template to the
10180 corresponding template parameters are replaced by the specified tem-
10181 plate argument values. If a substitution in a template parameter or
10182 in the function type of the function template results in an invalid
10183 type, type deduction fails. [Note: The equivalent substitution in
10184 exception specifications is done only when the function is instanti-
10185 ated, at which point a program is ill-formed if the substitution
10186 results in an invalid type.] */
10189 tsubst_function_type (tree t,
10191 tsubst_flags_t complain,
10198 /* The TYPE_CONTEXT is not used for function/method types. */
10199 gcc_assert (TYPE_CONTEXT (t) == NULL_TREE);
10201 /* Substitute the return type. */
10202 return_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10203 if (return_type == error_mark_node)
10204 return error_mark_node;
10205 /* The standard does not presently indicate that creation of a
10206 function type with an invalid return type is a deduction failure.
10207 However, that is clearly analogous to creating an array of "void"
10208 or a reference to a reference. This is core issue #486. */
10209 if (TREE_CODE (return_type) == ARRAY_TYPE
10210 || TREE_CODE (return_type) == FUNCTION_TYPE)
10212 if (complain & tf_error)
10214 if (TREE_CODE (return_type) == ARRAY_TYPE)
10215 error ("function returning an array");
10217 error ("function returning a function");
10219 return error_mark_node;
10222 /* Substitute the argument types. */
10223 arg_types = tsubst_arg_types (TYPE_ARG_TYPES (t), args,
10224 complain, in_decl);
10225 if (arg_types == error_mark_node)
10226 return error_mark_node;
10228 /* Construct a new type node and return it. */
10229 if (TREE_CODE (t) == FUNCTION_TYPE)
10231 fntype = build_function_type (return_type, arg_types);
10232 fntype = apply_memfn_quals (fntype, type_memfn_quals (t));
10236 tree r = TREE_TYPE (TREE_VALUE (arg_types));
10237 if (! MAYBE_CLASS_TYPE_P (r))
10241 Type deduction may fail for any of the following
10244 -- Attempting to create "pointer to member of T" when T
10245 is not a class type. */
10246 if (complain & tf_error)
10247 error ("creating pointer to member function of non-class type %qT",
10249 return error_mark_node;
10252 fntype = build_method_type_directly (r, return_type,
10253 TREE_CHAIN (arg_types));
10255 fntype = cp_build_type_attribute_variant (fntype, TYPE_ATTRIBUTES (t));
10260 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
10261 ARGS into that specification, and return the substituted
10262 specification. If there is no specification, return NULL_TREE. */
10265 tsubst_exception_specification (tree fntype,
10267 tsubst_flags_t complain,
10273 specs = TYPE_RAISES_EXCEPTIONS (fntype);
10274 new_specs = NULL_TREE;
10275 if (specs && TREE_PURPOSE (specs))
10277 /* A noexcept-specifier. */
10278 new_specs = tsubst_copy_and_build
10279 (TREE_PURPOSE (specs), args, complain, in_decl, /*function_p=*/false,
10280 /*integral_constant_expression_p=*/true);
10281 new_specs = build_noexcept_spec (new_specs, complain);
10285 if (! TREE_VALUE (specs))
10292 tree expanded_specs = NULL_TREE;
10294 if (PACK_EXPANSION_P (TREE_VALUE (specs)))
10296 /* Expand the pack expansion type. */
10297 expanded_specs = tsubst_pack_expansion (TREE_VALUE (specs),
10301 if (expanded_specs == error_mark_node)
10302 return error_mark_node;
10303 else if (TREE_CODE (expanded_specs) == TREE_VEC)
10304 len = TREE_VEC_LENGTH (expanded_specs);
10307 /* We're substituting into a member template, so
10308 we got a TYPE_PACK_EXPANSION back. Add that
10309 expansion and move on. */
10310 gcc_assert (TREE_CODE (expanded_specs)
10311 == TYPE_PACK_EXPANSION);
10312 new_specs = add_exception_specifier (new_specs,
10315 specs = TREE_CHAIN (specs);
10320 for (i = 0; i < len; ++i)
10322 if (expanded_specs)
10323 spec = TREE_VEC_ELT (expanded_specs, i);
10325 spec = tsubst (TREE_VALUE (specs), args, complain, in_decl);
10326 if (spec == error_mark_node)
10328 new_specs = add_exception_specifier (new_specs, spec,
10332 specs = TREE_CHAIN (specs);
10338 /* Take the tree structure T and replace template parameters used
10339 therein with the argument vector ARGS. IN_DECL is an associated
10340 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
10341 Issue error and warning messages under control of COMPLAIN. Note
10342 that we must be relatively non-tolerant of extensions here, in
10343 order to preserve conformance; if we allow substitutions that
10344 should not be allowed, we may allow argument deductions that should
10345 not succeed, and therefore report ambiguous overload situations
10346 where there are none. In theory, we could allow the substitution,
10347 but indicate that it should have failed, and allow our caller to
10348 make sure that the right thing happens, but we don't try to do this
10351 This function is used for dealing with types, decls and the like;
10352 for expressions, use tsubst_expr or tsubst_copy. */
10355 tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl)
10357 enum tree_code code;
10360 if (t == NULL_TREE || t == error_mark_node
10361 || t == integer_type_node
10362 || t == void_type_node
10363 || t == char_type_node
10364 || t == unknown_type_node
10365 || TREE_CODE (t) == NAMESPACE_DECL
10366 || TREE_CODE (t) == TRANSLATION_UNIT_DECL)
10370 return tsubst_decl (t, args, complain);
10372 if (args == NULL_TREE)
10375 code = TREE_CODE (t);
10377 if (code == IDENTIFIER_NODE)
10378 type = IDENTIFIER_TYPE_VALUE (t);
10380 type = TREE_TYPE (t);
10382 gcc_assert (type != unknown_type_node);
10384 /* Reuse typedefs. We need to do this to handle dependent attributes,
10385 such as attribute aligned. */
10387 && typedef_variant_p (t))
10389 tree decl = TYPE_NAME (t);
10391 if (DECL_CLASS_SCOPE_P (decl)
10392 && CLASSTYPE_TEMPLATE_INFO (DECL_CONTEXT (decl))
10393 && uses_template_parms (DECL_CONTEXT (decl)))
10395 tree tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
10396 tree gen_args = tsubst (DECL_TI_ARGS (decl), args, complain, in_decl);
10397 r = retrieve_specialization (tmpl, gen_args, 0);
10399 else if (DECL_FUNCTION_SCOPE_P (decl)
10400 && DECL_TEMPLATE_INFO (DECL_CONTEXT (decl))
10401 && uses_template_parms (DECL_TI_ARGS (DECL_CONTEXT (decl))))
10402 r = retrieve_local_specialization (decl);
10404 /* The typedef is from a non-template context. */
10410 r = cp_build_qualified_type_real
10411 (r, cp_type_quals (t) | cp_type_quals (r),
10412 complain | tf_ignore_bad_quals);
10415 /* Else we must be instantiating the typedef, so fall through. */
10419 && code != TYPENAME_TYPE
10420 && code != TEMPLATE_TYPE_PARM
10421 && code != IDENTIFIER_NODE
10422 && code != FUNCTION_TYPE
10423 && code != METHOD_TYPE)
10424 type = tsubst (type, args, complain, in_decl);
10425 if (type == error_mark_node)
10426 return error_mark_node;
10432 case ENUMERAL_TYPE:
10433 return tsubst_aggr_type (t, args, complain, in_decl,
10434 /*entering_scope=*/0);
10437 case IDENTIFIER_NODE:
10448 if (t == integer_type_node)
10451 if (TREE_CODE (TYPE_MIN_VALUE (t)) == INTEGER_CST
10452 && TREE_CODE (TYPE_MAX_VALUE (t)) == INTEGER_CST)
10456 tree max, omax = TREE_OPERAND (TYPE_MAX_VALUE (t), 0);
10458 max = tsubst_expr (omax, args, complain, in_decl,
10459 /*integral_constant_expression_p=*/false);
10461 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
10463 if (TREE_CODE (max) == NOP_EXPR
10464 && TREE_SIDE_EFFECTS (omax)
10465 && !TREE_TYPE (max))
10466 TREE_TYPE (max) = TREE_TYPE (TREE_OPERAND (max, 0));
10468 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
10469 with TREE_SIDE_EFFECTS that indicates this is not an integral
10470 constant expression. */
10471 if (processing_template_decl
10472 && TREE_SIDE_EFFECTS (omax) && TREE_CODE (omax) == NOP_EXPR)
10474 gcc_assert (TREE_CODE (max) == NOP_EXPR);
10475 TREE_SIDE_EFFECTS (max) = 1;
10478 return compute_array_index_type (NULL_TREE, max, complain);
10481 case TEMPLATE_TYPE_PARM:
10482 case TEMPLATE_TEMPLATE_PARM:
10483 case BOUND_TEMPLATE_TEMPLATE_PARM:
10484 case TEMPLATE_PARM_INDEX:
10489 tree arg = NULL_TREE;
10493 gcc_assert (TREE_VEC_LENGTH (args) > 0);
10494 template_parm_level_and_index (t, &level, &idx);
10496 levels = TMPL_ARGS_DEPTH (args);
10497 if (level <= levels)
10499 arg = TMPL_ARG (args, level, idx);
10501 if (arg && TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
10502 /* See through ARGUMENT_PACK_SELECT arguments. */
10503 arg = ARGUMENT_PACK_SELECT_ARG (arg);
10506 if (arg == error_mark_node)
10507 return error_mark_node;
10508 else if (arg != NULL_TREE)
10510 if (ARGUMENT_PACK_P (arg))
10511 /* If ARG is an argument pack, we don't actually want to
10512 perform a substitution here, because substitutions
10513 for argument packs are only done
10514 element-by-element. We can get to this point when
10515 substituting the type of a non-type template
10516 parameter pack, when that type actually contains
10517 template parameter packs from an outer template, e.g.,
10519 template<typename... Types> struct A {
10520 template<Types... Values> struct B { };
10524 if (code == TEMPLATE_TYPE_PARM)
10527 gcc_assert (TYPE_P (arg));
10529 quals = cp_type_quals (arg) | cp_type_quals (t);
10531 return cp_build_qualified_type_real
10532 (arg, quals, complain | tf_ignore_bad_quals);
10534 else if (code == BOUND_TEMPLATE_TEMPLATE_PARM)
10536 /* We are processing a type constructed from a
10537 template template parameter. */
10538 tree argvec = tsubst (TYPE_TI_ARGS (t),
10539 args, complain, in_decl);
10540 if (argvec == error_mark_node)
10541 return error_mark_node;
10543 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
10544 are resolving nested-types in the signature of a
10545 member function templates. Otherwise ARG is a
10546 TEMPLATE_DECL and is the real template to be
10548 if (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
10549 arg = TYPE_NAME (arg);
10551 r = lookup_template_class (arg,
10553 DECL_CONTEXT (arg),
10554 /*entering_scope=*/0,
10556 return cp_build_qualified_type_real
10557 (r, cp_type_quals (t), complain);
10560 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
10561 return unshare_expr (arg);
10565 /* This can happen during the attempted tsubst'ing in
10566 unify. This means that we don't yet have any information
10567 about the template parameter in question. */
10570 /* If we get here, we must have been looking at a parm for a
10571 more deeply nested template. Make a new version of this
10572 template parameter, but with a lower level. */
10575 case TEMPLATE_TYPE_PARM:
10576 case TEMPLATE_TEMPLATE_PARM:
10577 case BOUND_TEMPLATE_TEMPLATE_PARM:
10578 if (cp_type_quals (t))
10580 r = tsubst (TYPE_MAIN_VARIANT (t), args, complain, in_decl);
10581 r = cp_build_qualified_type_real
10582 (r, cp_type_quals (t),
10583 complain | (code == TEMPLATE_TYPE_PARM
10584 ? tf_ignore_bad_quals : 0));
10589 TEMPLATE_TYPE_PARM_INDEX (r)
10590 = reduce_template_parm_level (TEMPLATE_TYPE_PARM_INDEX (t),
10591 r, levels, args, complain);
10592 TYPE_STUB_DECL (r) = TYPE_NAME (r) = TEMPLATE_TYPE_DECL (r);
10593 TYPE_MAIN_VARIANT (r) = r;
10594 TYPE_POINTER_TO (r) = NULL_TREE;
10595 TYPE_REFERENCE_TO (r) = NULL_TREE;
10597 if (TREE_CODE (r) == TEMPLATE_TEMPLATE_PARM)
10598 /* We have reduced the level of the template
10599 template parameter, but not the levels of its
10600 template parameters, so canonical_type_parameter
10601 will not be able to find the canonical template
10602 template parameter for this level. Thus, we
10603 require structural equality checking to compare
10604 TEMPLATE_TEMPLATE_PARMs. */
10605 SET_TYPE_STRUCTURAL_EQUALITY (r);
10606 else if (TYPE_STRUCTURAL_EQUALITY_P (t))
10607 SET_TYPE_STRUCTURAL_EQUALITY (r);
10609 TYPE_CANONICAL (r) = canonical_type_parameter (r);
10611 if (code == BOUND_TEMPLATE_TEMPLATE_PARM)
10613 tree argvec = tsubst (TYPE_TI_ARGS (t), args,
10614 complain, in_decl);
10615 if (argvec == error_mark_node)
10616 return error_mark_node;
10618 TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (r)
10619 = build_template_info (TYPE_TI_TEMPLATE (t), argvec);
10624 case TEMPLATE_PARM_INDEX:
10625 r = reduce_template_parm_level (t, type, levels, args, complain);
10629 gcc_unreachable ();
10637 tree purpose, value, chain;
10639 if (t == void_list_node)
10642 purpose = TREE_PURPOSE (t);
10645 purpose = tsubst (purpose, args, complain, in_decl);
10646 if (purpose == error_mark_node)
10647 return error_mark_node;
10649 value = TREE_VALUE (t);
10652 value = tsubst (value, args, complain, in_decl);
10653 if (value == error_mark_node)
10654 return error_mark_node;
10656 chain = TREE_CHAIN (t);
10657 if (chain && chain != void_type_node)
10659 chain = tsubst (chain, args, complain, in_decl);
10660 if (chain == error_mark_node)
10661 return error_mark_node;
10663 if (purpose == TREE_PURPOSE (t)
10664 && value == TREE_VALUE (t)
10665 && chain == TREE_CHAIN (t))
10667 return hash_tree_cons (purpose, value, chain);
10671 /* We should never be tsubsting a binfo. */
10672 gcc_unreachable ();
10675 /* A vector of template arguments. */
10676 gcc_assert (!type);
10677 return tsubst_template_args (t, args, complain, in_decl);
10680 case REFERENCE_TYPE:
10682 if (type == TREE_TYPE (t) && TREE_CODE (type) != METHOD_TYPE)
10687 Type deduction may fail for any of the following
10690 -- Attempting to create a pointer to reference type.
10691 -- Attempting to create a reference to a reference type or
10692 a reference to void.
10694 Core issue 106 says that creating a reference to a reference
10695 during instantiation is no longer a cause for failure. We
10696 only enforce this check in strict C++98 mode. */
10697 if ((TREE_CODE (type) == REFERENCE_TYPE
10698 && (((cxx_dialect == cxx98) && flag_iso) || code != REFERENCE_TYPE))
10699 || (code == REFERENCE_TYPE && TREE_CODE (type) == VOID_TYPE))
10701 static location_t last_loc;
10703 /* We keep track of the last time we issued this error
10704 message to avoid spewing a ton of messages during a
10705 single bad template instantiation. */
10706 if (complain & tf_error
10707 && last_loc != input_location)
10709 if (TREE_CODE (type) == VOID_TYPE)
10710 error ("forming reference to void");
10711 else if (code == POINTER_TYPE)
10712 error ("forming pointer to reference type %qT", type);
10714 error ("forming reference to reference type %qT", type);
10715 last_loc = input_location;
10718 return error_mark_node;
10720 else if (code == POINTER_TYPE)
10722 r = build_pointer_type (type);
10723 if (TREE_CODE (type) == METHOD_TYPE)
10724 r = build_ptrmemfunc_type (r);
10726 else if (TREE_CODE (type) == REFERENCE_TYPE)
10727 /* In C++0x, during template argument substitution, when there is an
10728 attempt to create a reference to a reference type, reference
10729 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
10731 "If a template-argument for a template-parameter T names a type
10732 that is a reference to a type A, an attempt to create the type
10733 'lvalue reference to cv T' creates the type 'lvalue reference to
10734 A,' while an attempt to create the type type rvalue reference to
10735 cv T' creates the type T"
10737 r = cp_build_reference_type
10739 TYPE_REF_IS_RVALUE (t) && TYPE_REF_IS_RVALUE (type));
10741 r = cp_build_reference_type (type, TYPE_REF_IS_RVALUE (t));
10742 r = cp_build_qualified_type_real (r, cp_type_quals (t), complain);
10744 if (r != error_mark_node)
10745 /* Will this ever be needed for TYPE_..._TO values? */
10752 r = tsubst (TYPE_OFFSET_BASETYPE (t), args, complain, in_decl);
10753 if (r == error_mark_node || !MAYBE_CLASS_TYPE_P (r))
10757 Type deduction may fail for any of the following
10760 -- Attempting to create "pointer to member of T" when T
10761 is not a class type. */
10762 if (complain & tf_error)
10763 error ("creating pointer to member of non-class type %qT", r);
10764 return error_mark_node;
10766 if (TREE_CODE (type) == REFERENCE_TYPE)
10768 if (complain & tf_error)
10769 error ("creating pointer to member reference type %qT", type);
10770 return error_mark_node;
10772 if (TREE_CODE (type) == VOID_TYPE)
10774 if (complain & tf_error)
10775 error ("creating pointer to member of type void");
10776 return error_mark_node;
10778 gcc_assert (TREE_CODE (type) != METHOD_TYPE);
10779 if (TREE_CODE (type) == FUNCTION_TYPE)
10781 /* The type of the implicit object parameter gets its
10782 cv-qualifiers from the FUNCTION_TYPE. */
10784 tree method_type = build_memfn_type (type, r, type_memfn_quals (type));
10785 memptr = build_ptrmemfunc_type (build_pointer_type (method_type));
10786 return cp_build_qualified_type_real (memptr, cp_type_quals (t),
10790 return cp_build_qualified_type_real (build_ptrmem_type (r, type),
10794 case FUNCTION_TYPE:
10799 fntype = tsubst_function_type (t, args, complain, in_decl);
10800 if (fntype == error_mark_node)
10801 return error_mark_node;
10803 /* Substitute the exception specification. */
10804 specs = tsubst_exception_specification (t, args, complain,
10806 if (specs == error_mark_node)
10807 return error_mark_node;
10809 fntype = build_exception_variant (fntype, specs);
10814 tree domain = tsubst (TYPE_DOMAIN (t), args, complain, in_decl);
10815 if (domain == error_mark_node)
10816 return error_mark_node;
10818 /* As an optimization, we avoid regenerating the array type if
10819 it will obviously be the same as T. */
10820 if (type == TREE_TYPE (t) && domain == TYPE_DOMAIN (t))
10823 /* These checks should match the ones in grokdeclarator.
10827 The deduction may fail for any of the following reasons:
10829 -- Attempting to create an array with an element type that
10830 is void, a function type, or a reference type, or [DR337]
10831 an abstract class type. */
10832 if (TREE_CODE (type) == VOID_TYPE
10833 || TREE_CODE (type) == FUNCTION_TYPE
10834 || TREE_CODE (type) == REFERENCE_TYPE)
10836 if (complain & tf_error)
10837 error ("creating array of %qT", type);
10838 return error_mark_node;
10840 if (CLASS_TYPE_P (type) && CLASSTYPE_PURE_VIRTUALS (type))
10842 if (complain & tf_error)
10843 error ("creating array of %qT, which is an abstract class type",
10845 return error_mark_node;
10848 r = build_cplus_array_type (type, domain);
10850 if (TYPE_USER_ALIGN (t))
10852 TYPE_ALIGN (r) = TYPE_ALIGN (t);
10853 TYPE_USER_ALIGN (r) = 1;
10859 case TYPENAME_TYPE:
10861 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
10862 in_decl, /*entering_scope=*/1);
10863 tree f = tsubst_copy (TYPENAME_TYPE_FULLNAME (t), args,
10864 complain, in_decl);
10866 if (ctx == error_mark_node || f == error_mark_node)
10867 return error_mark_node;
10869 if (!MAYBE_CLASS_TYPE_P (ctx))
10871 if (complain & tf_error)
10872 error ("%qT is not a class, struct, or union type", ctx);
10873 return error_mark_node;
10875 else if (!uses_template_parms (ctx) && !TYPE_BEING_DEFINED (ctx))
10877 /* Normally, make_typename_type does not require that the CTX
10878 have complete type in order to allow things like:
10880 template <class T> struct S { typename S<T>::X Y; };
10882 But, such constructs have already been resolved by this
10883 point, so here CTX really should have complete type, unless
10884 it's a partial instantiation. */
10885 ctx = complete_type (ctx);
10886 if (!COMPLETE_TYPE_P (ctx))
10888 if (complain & tf_error)
10889 cxx_incomplete_type_error (NULL_TREE, ctx);
10890 return error_mark_node;
10894 f = make_typename_type (ctx, f, typename_type,
10895 (complain & tf_error) | tf_keep_type_decl);
10896 if (f == error_mark_node)
10898 if (TREE_CODE (f) == TYPE_DECL)
10900 complain |= tf_ignore_bad_quals;
10904 if (TREE_CODE (f) != TYPENAME_TYPE)
10906 if (TYPENAME_IS_ENUM_P (t) && TREE_CODE (f) != ENUMERAL_TYPE)
10907 error ("%qT resolves to %qT, which is not an enumeration type",
10909 else if (TYPENAME_IS_CLASS_P (t) && !CLASS_TYPE_P (f))
10910 error ("%qT resolves to %qT, which is is not a class type",
10914 return cp_build_qualified_type_real
10915 (f, cp_type_quals (f) | cp_type_quals (t), complain);
10918 case UNBOUND_CLASS_TEMPLATE:
10920 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
10921 in_decl, /*entering_scope=*/1);
10922 tree name = TYPE_IDENTIFIER (t);
10923 tree parm_list = DECL_TEMPLATE_PARMS (TYPE_NAME (t));
10925 if (ctx == error_mark_node || name == error_mark_node)
10926 return error_mark_node;
10929 parm_list = tsubst_template_parms (parm_list, args, complain);
10930 return make_unbound_class_template (ctx, name, parm_list, complain);
10937 ++cp_unevaluated_operand;
10938 ++c_inhibit_evaluation_warnings;
10940 type = tsubst_expr (TYPEOF_TYPE_EXPR (t), args,
10942 /*integral_constant_expression_p=*/false);
10944 --cp_unevaluated_operand;
10945 --c_inhibit_evaluation_warnings;
10947 type = finish_typeof (type);
10948 return cp_build_qualified_type_real (type,
10950 | cp_type_quals (type),
10954 case DECLTYPE_TYPE:
10958 ++cp_unevaluated_operand;
10959 ++c_inhibit_evaluation_warnings;
10961 type = tsubst_expr (DECLTYPE_TYPE_EXPR (t), args,
10963 /*integral_constant_expression_p=*/false);
10965 --cp_unevaluated_operand;
10966 --c_inhibit_evaluation_warnings;
10968 if (DECLTYPE_FOR_LAMBDA_CAPTURE (t))
10969 type = lambda_capture_field_type (type);
10970 else if (DECLTYPE_FOR_LAMBDA_RETURN (t))
10971 type = lambda_return_type (type);
10973 type = finish_decltype_type
10974 (type, DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t));
10975 return cp_build_qualified_type_real (type,
10977 | cp_type_quals (type),
10981 case TYPE_ARGUMENT_PACK:
10982 case NONTYPE_ARGUMENT_PACK:
10984 tree r = TYPE_P (t) ? cxx_make_type (code) : make_node (code);
10986 tsubst_template_args (ARGUMENT_PACK_ARGS (t),
10990 SET_ARGUMENT_PACK_ARGS (r, packed_out);
10992 /* For template nontype argument packs, also substitute into
10994 if (code == NONTYPE_ARGUMENT_PACK)
10995 TREE_TYPE (r) = tsubst (TREE_TYPE (t), args, complain, in_decl);
11013 /* We should use one of the expression tsubsts for these codes. */
11014 gcc_unreachable ();
11017 sorry ("use of %qs in template", tree_code_name [(int) code]);
11018 return error_mark_node;
11022 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
11023 type of the expression on the left-hand side of the "." or "->"
11027 tsubst_baselink (tree baselink, tree object_type,
11028 tree args, tsubst_flags_t complain, tree in_decl)
11031 tree qualifying_scope;
11034 tree template_args = 0;
11035 bool template_id_p = false;
11037 /* A baselink indicates a function from a base class. Both the
11038 BASELINK_ACCESS_BINFO and the base class referenced may
11039 indicate bases of the template class, rather than the
11040 instantiated class. In addition, lookups that were not
11041 ambiguous before may be ambiguous now. Therefore, we perform
11042 the lookup again. */
11043 qualifying_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (baselink));
11044 qualifying_scope = tsubst (qualifying_scope, args,
11045 complain, in_decl);
11046 fns = BASELINK_FUNCTIONS (baselink);
11047 optype = tsubst (BASELINK_OPTYPE (baselink), args, complain, in_decl);
11048 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
11050 template_id_p = true;
11051 template_args = TREE_OPERAND (fns, 1);
11052 fns = TREE_OPERAND (fns, 0);
11054 template_args = tsubst_template_args (template_args, args,
11055 complain, in_decl);
11057 name = DECL_NAME (get_first_fn (fns));
11058 if (IDENTIFIER_TYPENAME_P (name))
11059 name = mangle_conv_op_name_for_type (optype);
11060 baselink = lookup_fnfields (qualifying_scope, name, /*protect=*/1);
11062 return error_mark_node;
11064 /* If lookup found a single function, mark it as used at this
11065 point. (If it lookup found multiple functions the one selected
11066 later by overload resolution will be marked as used at that
11068 if (BASELINK_P (baselink))
11069 fns = BASELINK_FUNCTIONS (baselink);
11070 if (!template_id_p && !really_overloaded_fn (fns))
11071 mark_used (OVL_CURRENT (fns));
11073 /* Add back the template arguments, if present. */
11074 if (BASELINK_P (baselink) && template_id_p)
11075 BASELINK_FUNCTIONS (baselink)
11076 = build_nt (TEMPLATE_ID_EXPR,
11077 BASELINK_FUNCTIONS (baselink),
11079 /* Update the conversion operator type. */
11080 BASELINK_OPTYPE (baselink) = optype;
11083 object_type = current_class_type;
11084 return adjust_result_of_qualified_name_lookup (baselink,
11089 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
11090 true if the qualified-id will be a postfix-expression in-and-of
11091 itself; false if more of the postfix-expression follows the
11092 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
11096 tsubst_qualified_id (tree qualified_id, tree args,
11097 tsubst_flags_t complain, tree in_decl,
11098 bool done, bool address_p)
11104 tree template_args;
11106 gcc_assert (TREE_CODE (qualified_id) == SCOPE_REF);
11108 /* Figure out what name to look up. */
11109 name = TREE_OPERAND (qualified_id, 1);
11110 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
11112 is_template = true;
11113 template_args = TREE_OPERAND (name, 1);
11115 template_args = tsubst_template_args (template_args, args,
11116 complain, in_decl);
11117 name = TREE_OPERAND (name, 0);
11121 is_template = false;
11122 template_args = NULL_TREE;
11125 /* Substitute into the qualifying scope. When there are no ARGS, we
11126 are just trying to simplify a non-dependent expression. In that
11127 case the qualifying scope may be dependent, and, in any case,
11128 substituting will not help. */
11129 scope = TREE_OPERAND (qualified_id, 0);
11132 scope = tsubst (scope, args, complain, in_decl);
11133 expr = tsubst_copy (name, args, complain, in_decl);
11138 if (dependent_scope_p (scope))
11139 return build_qualified_name (NULL_TREE, scope, expr,
11140 QUALIFIED_NAME_IS_TEMPLATE (qualified_id));
11142 if (!BASELINK_P (name) && !DECL_P (expr))
11144 if (TREE_CODE (expr) == BIT_NOT_EXPR)
11146 /* A BIT_NOT_EXPR is used to represent a destructor. */
11147 if (!check_dtor_name (scope, TREE_OPERAND (expr, 0)))
11149 error ("qualifying type %qT does not match destructor name ~%qT",
11150 scope, TREE_OPERAND (expr, 0));
11151 expr = error_mark_node;
11154 expr = lookup_qualified_name (scope, complete_dtor_identifier,
11155 /*is_type_p=*/0, false);
11158 expr = lookup_qualified_name (scope, expr, /*is_type_p=*/0, false);
11159 if (TREE_CODE (TREE_CODE (expr) == TEMPLATE_DECL
11160 ? DECL_TEMPLATE_RESULT (expr) : expr) == TYPE_DECL)
11162 if (complain & tf_error)
11164 error ("dependent-name %qE is parsed as a non-type, but "
11165 "instantiation yields a type", qualified_id);
11166 inform (input_location, "say %<typename %E%> if a type is meant", qualified_id);
11168 return error_mark_node;
11174 check_accessibility_of_qualified_id (expr, /*object_type=*/NULL_TREE,
11176 /* Remember that there was a reference to this entity. */
11180 if (expr == error_mark_node || TREE_CODE (expr) == TREE_LIST)
11182 if (complain & tf_error)
11183 qualified_name_lookup_error (scope,
11184 TREE_OPERAND (qualified_id, 1),
11185 expr, input_location);
11186 return error_mark_node;
11190 expr = lookup_template_function (expr, template_args);
11192 if (expr == error_mark_node && complain & tf_error)
11193 qualified_name_lookup_error (scope, TREE_OPERAND (qualified_id, 1),
11194 expr, input_location);
11195 else if (TYPE_P (scope))
11197 expr = (adjust_result_of_qualified_name_lookup
11198 (expr, scope, current_class_type));
11199 expr = (finish_qualified_id_expr
11200 (scope, expr, done, address_p,
11201 QUALIFIED_NAME_IS_TEMPLATE (qualified_id),
11202 /*template_arg_p=*/false));
11205 /* Expressions do not generally have reference type. */
11206 if (TREE_CODE (expr) != SCOPE_REF
11207 /* However, if we're about to form a pointer-to-member, we just
11208 want the referenced member referenced. */
11209 && TREE_CODE (expr) != OFFSET_REF)
11210 expr = convert_from_reference (expr);
11215 /* Like tsubst, but deals with expressions. This function just replaces
11216 template parms; to finish processing the resultant expression, use
11220 tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl)
11222 enum tree_code code;
11225 if (t == NULL_TREE || t == error_mark_node || args == NULL_TREE)
11228 code = TREE_CODE (t);
11233 r = retrieve_local_specialization (t);
11238 /* This can happen for a parameter name used later in a function
11239 declaration (such as in a late-specified return type). Just
11240 make a dummy decl, since it's only used for its type. */
11241 gcc_assert (cp_unevaluated_operand != 0);
11242 /* We copy T because want to tsubst the PARM_DECL only,
11243 not the following PARM_DECLs that are chained to T. */
11245 r = tsubst_decl (c, args, complain);
11246 /* Give it the template pattern as its context; its true context
11247 hasn't been instantiated yet and this is good enough for
11249 DECL_CONTEXT (r) = DECL_CONTEXT (t);
11252 if (TREE_CODE (r) == ARGUMENT_PACK_SELECT)
11253 r = ARGUMENT_PACK_SELECT_ARG (r);
11262 if (DECL_TEMPLATE_PARM_P (t))
11263 return tsubst_copy (DECL_INITIAL (t), args, complain, in_decl);
11264 /* There is no need to substitute into namespace-scope
11266 if (DECL_NAMESPACE_SCOPE_P (t))
11268 /* If ARGS is NULL, then T is known to be non-dependent. */
11269 if (args == NULL_TREE)
11270 return integral_constant_value (t);
11272 /* Unfortunately, we cannot just call lookup_name here.
11275 template <int I> int f() {
11277 struct S { void g() { E e = a; } };
11280 When we instantiate f<7>::S::g(), say, lookup_name is not
11281 clever enough to find f<7>::a. */
11283 = tsubst_aggr_type (TREE_TYPE (t), args, complain, in_decl,
11284 /*entering_scope=*/0);
11286 for (v = TYPE_VALUES (enum_type);
11288 v = TREE_CHAIN (v))
11289 if (TREE_PURPOSE (v) == DECL_NAME (t))
11290 return TREE_VALUE (v);
11292 /* We didn't find the name. That should never happen; if
11293 name-lookup found it during preliminary parsing, we
11294 should find it again here during instantiation. */
11295 gcc_unreachable ();
11300 if (DECL_CONTEXT (t))
11304 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args, complain, in_decl,
11305 /*entering_scope=*/1);
11306 if (ctx != DECL_CONTEXT (t))
11308 tree r = lookup_field (ctx, DECL_NAME (t), 0, false);
11311 if (complain & tf_error)
11312 error ("using invalid field %qD", t);
11313 return error_mark_node;
11322 case FUNCTION_DECL:
11323 if ((DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t))
11324 || local_variable_p (t))
11325 t = tsubst (t, args, complain, in_decl);
11330 /* An OVERLOAD will always be a non-dependent overload set; an
11331 overload set from function scope will just be represented with an
11332 IDENTIFIER_NODE, and from class scope with a BASELINK. */
11333 gcc_assert (!uses_template_parms (t));
11337 return tsubst_baselink (t, current_class_type, args, complain, in_decl);
11339 case TEMPLATE_DECL:
11340 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
11341 return tsubst (TREE_TYPE (DECL_TEMPLATE_RESULT (t)),
11342 args, complain, in_decl);
11343 else if (DECL_FUNCTION_TEMPLATE_P (t) && DECL_MEMBER_TEMPLATE_P (t))
11344 return tsubst (t, args, complain, in_decl);
11345 else if (DECL_CLASS_SCOPE_P (t)
11346 && uses_template_parms (DECL_CONTEXT (t)))
11348 /* Template template argument like the following example need
11351 template <template <class> class TT> struct C {};
11352 template <class T> struct D {
11353 template <class U> struct E {};
11358 We are processing the template argument `E' in #1 for
11359 the template instantiation #2. Originally, `E' is a
11360 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
11361 have to substitute this with one having context `D<int>'. */
11363 tree context = tsubst (DECL_CONTEXT (t), args, complain, in_decl);
11364 return lookup_field (context, DECL_NAME(t), 0, false);
11367 /* Ordinary template template argument. */
11371 case REINTERPRET_CAST_EXPR:
11372 case CONST_CAST_EXPR:
11373 case STATIC_CAST_EXPR:
11374 case DYNAMIC_CAST_EXPR:
11377 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
11378 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
11381 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
11383 /* We only want to compute the number of arguments. */
11384 tree expanded = tsubst_pack_expansion (TREE_OPERAND (t, 0), args,
11385 complain, in_decl);
11388 if (TREE_CODE (expanded) == TREE_VEC)
11389 len = TREE_VEC_LENGTH (expanded);
11391 if (expanded == error_mark_node)
11392 return error_mark_node;
11393 else if (PACK_EXPANSION_P (expanded)
11394 || (TREE_CODE (expanded) == TREE_VEC
11396 && PACK_EXPANSION_P (TREE_VEC_ELT (expanded, len-1))))
11398 if (TREE_CODE (expanded) == TREE_VEC)
11399 expanded = TREE_VEC_ELT (expanded, len - 1);
11401 if (TYPE_P (expanded))
11402 return cxx_sizeof_or_alignof_type (expanded, SIZEOF_EXPR,
11403 complain & tf_error);
11405 return cxx_sizeof_or_alignof_expr (expanded, SIZEOF_EXPR,
11406 complain & tf_error);
11409 return build_int_cst (size_type_node, len);
11415 case TRUTH_NOT_EXPR:
11418 case UNARY_PLUS_EXPR: /* Unary + */
11420 case AT_ENCODE_EXPR:
11424 case REALPART_EXPR:
11425 case IMAGPART_EXPR:
11427 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
11428 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
11430 case COMPONENT_REF:
11435 object = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
11436 name = TREE_OPERAND (t, 1);
11437 if (TREE_CODE (name) == BIT_NOT_EXPR)
11439 name = tsubst_copy (TREE_OPERAND (name, 0), args,
11440 complain, in_decl);
11441 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
11443 else if (TREE_CODE (name) == SCOPE_REF
11444 && TREE_CODE (TREE_OPERAND (name, 1)) == BIT_NOT_EXPR)
11446 tree base = tsubst_copy (TREE_OPERAND (name, 0), args,
11447 complain, in_decl);
11448 name = TREE_OPERAND (name, 1);
11449 name = tsubst_copy (TREE_OPERAND (name, 0), args,
11450 complain, in_decl);
11451 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
11452 name = build_qualified_name (/*type=*/NULL_TREE,
11454 /*template_p=*/false);
11456 else if (TREE_CODE (name) == BASELINK)
11457 name = tsubst_baselink (name,
11458 non_reference (TREE_TYPE (object)),
11462 name = tsubst_copy (name, args, complain, in_decl);
11463 return build_nt (COMPONENT_REF, object, name, NULL_TREE);
11469 case TRUNC_DIV_EXPR:
11470 case CEIL_DIV_EXPR:
11471 case FLOOR_DIV_EXPR:
11472 case ROUND_DIV_EXPR:
11473 case EXACT_DIV_EXPR:
11477 case TRUNC_MOD_EXPR:
11478 case FLOOR_MOD_EXPR:
11479 case TRUTH_ANDIF_EXPR:
11480 case TRUTH_ORIF_EXPR:
11481 case TRUTH_AND_EXPR:
11482 case TRUTH_OR_EXPR:
11495 case COMPOUND_EXPR:
11498 case PREDECREMENT_EXPR:
11499 case PREINCREMENT_EXPR:
11500 case POSTDECREMENT_EXPR:
11501 case POSTINCREMENT_EXPR:
11503 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11504 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
11507 return build_qualified_name (/*type=*/NULL_TREE,
11508 tsubst_copy (TREE_OPERAND (t, 0),
11509 args, complain, in_decl),
11510 tsubst_copy (TREE_OPERAND (t, 1),
11511 args, complain, in_decl),
11512 QUALIFIED_NAME_IS_TEMPLATE (t));
11517 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11518 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
11519 NULL_TREE, NULL_TREE);
11523 int n = VL_EXP_OPERAND_LENGTH (t);
11524 tree result = build_vl_exp (CALL_EXPR, n);
11526 for (i = 0; i < n; i++)
11527 TREE_OPERAND (t, i) = tsubst_copy (TREE_OPERAND (t, i), args,
11528 complain, in_decl);
11534 case PSEUDO_DTOR_EXPR:
11537 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11538 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
11539 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
11540 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
11547 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11548 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
11549 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
11550 NEW_EXPR_USE_GLOBAL (r) = NEW_EXPR_USE_GLOBAL (t);
11557 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11558 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
11559 DELETE_EXPR_USE_GLOBAL (r) = DELETE_EXPR_USE_GLOBAL (t);
11560 DELETE_EXPR_USE_VEC (r) = DELETE_EXPR_USE_VEC (t);
11564 case TEMPLATE_ID_EXPR:
11566 /* Substituted template arguments */
11567 tree fn = TREE_OPERAND (t, 0);
11568 tree targs = TREE_OPERAND (t, 1);
11570 fn = tsubst_copy (fn, args, complain, in_decl);
11572 targs = tsubst_template_args (targs, args, complain, in_decl);
11574 return lookup_template_function (fn, targs);
11579 tree purpose, value, chain;
11581 if (t == void_list_node)
11584 purpose = TREE_PURPOSE (t);
11586 purpose = tsubst_copy (purpose, args, complain, in_decl);
11587 value = TREE_VALUE (t);
11589 value = tsubst_copy (value, args, complain, in_decl);
11590 chain = TREE_CHAIN (t);
11591 if (chain && chain != void_type_node)
11592 chain = tsubst_copy (chain, args, complain, in_decl);
11593 if (purpose == TREE_PURPOSE (t)
11594 && value == TREE_VALUE (t)
11595 && chain == TREE_CHAIN (t))
11597 return tree_cons (purpose, value, chain);
11602 case ENUMERAL_TYPE:
11604 case TEMPLATE_TYPE_PARM:
11605 case TEMPLATE_TEMPLATE_PARM:
11606 case BOUND_TEMPLATE_TEMPLATE_PARM:
11607 case TEMPLATE_PARM_INDEX:
11609 case REFERENCE_TYPE:
11611 case FUNCTION_TYPE:
11614 case TYPENAME_TYPE:
11615 case UNBOUND_CLASS_TEMPLATE:
11617 case DECLTYPE_TYPE:
11619 return tsubst (t, args, complain, in_decl);
11621 case IDENTIFIER_NODE:
11622 if (IDENTIFIER_TYPENAME_P (t))
11624 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
11625 return mangle_conv_op_name_for_type (new_type);
11631 /* This is handled by tsubst_copy_and_build. */
11632 gcc_unreachable ();
11635 return build_x_va_arg (tsubst_copy (TREE_OPERAND (t, 0), args, complain,
11637 tsubst (TREE_TYPE (t), args, complain, in_decl));
11639 case CLEANUP_POINT_EXPR:
11640 /* We shouldn't have built any of these during initial template
11641 generation. Instead, they should be built during instantiation
11642 in response to the saved STMT_IS_FULL_EXPR_P setting. */
11643 gcc_unreachable ();
11647 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
11648 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11649 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
11650 PTRMEM_OK_P (r) = PTRMEM_OK_P (t);
11651 mark_used (TREE_OPERAND (r, 1));
11654 case EXPR_PACK_EXPANSION:
11655 error ("invalid use of pack expansion expression");
11656 return error_mark_node;
11658 case NONTYPE_ARGUMENT_PACK:
11659 error ("use %<...%> to expand argument pack");
11660 return error_mark_node;
11667 /* Instantiate any typedefs in the type. */
11668 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
11669 r = fold_convert (type, t);
11670 gcc_assert (TREE_CODE (r) == code);
11675 /* These can sometimes show up in a partial instantiation, but never
11676 involve template parms. */
11677 gcc_assert (!uses_template_parms (t));
11681 gcc_unreachable ();
11685 /* Like tsubst_copy, but specifically for OpenMP clauses. */
11688 tsubst_omp_clauses (tree clauses, tree args, tsubst_flags_t complain,
11691 tree new_clauses = NULL, nc, oc;
11693 for (oc = clauses; oc ; oc = OMP_CLAUSE_CHAIN (oc))
11695 nc = copy_node (oc);
11696 OMP_CLAUSE_CHAIN (nc) = new_clauses;
11699 switch (OMP_CLAUSE_CODE (nc))
11701 case OMP_CLAUSE_LASTPRIVATE:
11702 if (OMP_CLAUSE_LASTPRIVATE_STMT (oc))
11704 OMP_CLAUSE_LASTPRIVATE_STMT (nc) = push_stmt_list ();
11705 tsubst_expr (OMP_CLAUSE_LASTPRIVATE_STMT (oc), args, complain,
11706 in_decl, /*integral_constant_expression_p=*/false);
11707 OMP_CLAUSE_LASTPRIVATE_STMT (nc)
11708 = pop_stmt_list (OMP_CLAUSE_LASTPRIVATE_STMT (nc));
11711 case OMP_CLAUSE_PRIVATE:
11712 case OMP_CLAUSE_SHARED:
11713 case OMP_CLAUSE_FIRSTPRIVATE:
11714 case OMP_CLAUSE_REDUCTION:
11715 case OMP_CLAUSE_COPYIN:
11716 case OMP_CLAUSE_COPYPRIVATE:
11717 case OMP_CLAUSE_IF:
11718 case OMP_CLAUSE_NUM_THREADS:
11719 case OMP_CLAUSE_SCHEDULE:
11720 case OMP_CLAUSE_COLLAPSE:
11721 OMP_CLAUSE_OPERAND (nc, 0)
11722 = tsubst_expr (OMP_CLAUSE_OPERAND (oc, 0), args, complain,
11723 in_decl, /*integral_constant_expression_p=*/false);
11725 case OMP_CLAUSE_NOWAIT:
11726 case OMP_CLAUSE_ORDERED:
11727 case OMP_CLAUSE_DEFAULT:
11728 case OMP_CLAUSE_UNTIED:
11731 gcc_unreachable ();
11735 return finish_omp_clauses (nreverse (new_clauses));
11738 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
11741 tsubst_copy_asm_operands (tree t, tree args, tsubst_flags_t complain,
11744 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
11746 tree purpose, value, chain;
11751 if (TREE_CODE (t) != TREE_LIST)
11752 return tsubst_copy_and_build (t, args, complain, in_decl,
11753 /*function_p=*/false,
11754 /*integral_constant_expression_p=*/false);
11756 if (t == void_list_node)
11759 purpose = TREE_PURPOSE (t);
11761 purpose = RECUR (purpose);
11762 value = TREE_VALUE (t);
11763 if (value && TREE_CODE (value) != LABEL_DECL)
11764 value = RECUR (value);
11765 chain = TREE_CHAIN (t);
11766 if (chain && chain != void_type_node)
11767 chain = RECUR (chain);
11768 return tree_cons (purpose, value, chain);
11772 /* Substitute one OMP_FOR iterator. */
11775 tsubst_omp_for_iterator (tree t, int i, tree declv, tree initv,
11776 tree condv, tree incrv, tree *clauses,
11777 tree args, tsubst_flags_t complain, tree in_decl,
11778 bool integral_constant_expression_p)
11780 #define RECUR(NODE) \
11781 tsubst_expr ((NODE), args, complain, in_decl, \
11782 integral_constant_expression_p)
11783 tree decl, init, cond, incr, auto_node;
11785 init = TREE_VEC_ELT (OMP_FOR_INIT (t), i);
11786 gcc_assert (TREE_CODE (init) == MODIFY_EXPR);
11787 decl = RECUR (TREE_OPERAND (init, 0));
11788 init = TREE_OPERAND (init, 1);
11789 auto_node = type_uses_auto (TREE_TYPE (decl));
11790 if (auto_node && init)
11792 tree init_expr = init;
11793 if (TREE_CODE (init_expr) == DECL_EXPR)
11794 init_expr = DECL_INITIAL (DECL_EXPR_DECL (init_expr));
11795 init_expr = RECUR (init_expr);
11797 = do_auto_deduction (TREE_TYPE (decl), init_expr, auto_node);
11799 gcc_assert (!type_dependent_expression_p (decl));
11801 if (!CLASS_TYPE_P (TREE_TYPE (decl)))
11803 cond = RECUR (TREE_VEC_ELT (OMP_FOR_COND (t), i));
11804 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
11805 if (TREE_CODE (incr) == MODIFY_EXPR)
11806 incr = build_x_modify_expr (RECUR (TREE_OPERAND (incr, 0)), NOP_EXPR,
11807 RECUR (TREE_OPERAND (incr, 1)),
11810 incr = RECUR (incr);
11811 TREE_VEC_ELT (declv, i) = decl;
11812 TREE_VEC_ELT (initv, i) = init;
11813 TREE_VEC_ELT (condv, i) = cond;
11814 TREE_VEC_ELT (incrv, i) = incr;
11818 if (init && TREE_CODE (init) != DECL_EXPR)
11821 for (c = *clauses; c ; c = OMP_CLAUSE_CHAIN (c))
11823 if ((OMP_CLAUSE_CODE (c) == OMP_CLAUSE_PRIVATE
11824 || OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LASTPRIVATE)
11825 && OMP_CLAUSE_DECL (c) == decl)
11827 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_FIRSTPRIVATE
11828 && OMP_CLAUSE_DECL (c) == decl)
11829 error ("iteration variable %qD should not be firstprivate", decl);
11830 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_REDUCTION
11831 && OMP_CLAUSE_DECL (c) == decl)
11832 error ("iteration variable %qD should not be reduction", decl);
11836 c = build_omp_clause (input_location, OMP_CLAUSE_PRIVATE);
11837 OMP_CLAUSE_DECL (c) = decl;
11838 c = finish_omp_clauses (c);
11841 OMP_CLAUSE_CHAIN (c) = *clauses;
11846 cond = TREE_VEC_ELT (OMP_FOR_COND (t), i);
11847 if (COMPARISON_CLASS_P (cond))
11848 cond = build2 (TREE_CODE (cond), boolean_type_node,
11849 RECUR (TREE_OPERAND (cond, 0)),
11850 RECUR (TREE_OPERAND (cond, 1)));
11852 cond = RECUR (cond);
11853 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
11854 switch (TREE_CODE (incr))
11856 case PREINCREMENT_EXPR:
11857 case PREDECREMENT_EXPR:
11858 case POSTINCREMENT_EXPR:
11859 case POSTDECREMENT_EXPR:
11860 incr = build2 (TREE_CODE (incr), TREE_TYPE (decl),
11861 RECUR (TREE_OPERAND (incr, 0)), NULL_TREE);
11864 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
11865 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
11867 tree rhs = TREE_OPERAND (incr, 1);
11868 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
11869 RECUR (TREE_OPERAND (incr, 0)),
11870 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
11871 RECUR (TREE_OPERAND (rhs, 0)),
11872 RECUR (TREE_OPERAND (rhs, 1))));
11875 incr = RECUR (incr);
11878 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
11879 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
11881 tree lhs = RECUR (TREE_OPERAND (incr, 0));
11882 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl), lhs,
11883 build2 (TREE_CODE (TREE_OPERAND (incr, 1)),
11884 TREE_TYPE (decl), lhs,
11885 RECUR (TREE_OPERAND (incr, 2))));
11887 else if (TREE_CODE (TREE_OPERAND (incr, 1)) == NOP_EXPR
11888 && (TREE_CODE (TREE_OPERAND (incr, 2)) == PLUS_EXPR
11889 || (TREE_CODE (TREE_OPERAND (incr, 2)) == MINUS_EXPR)))
11891 tree rhs = TREE_OPERAND (incr, 2);
11892 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
11893 RECUR (TREE_OPERAND (incr, 0)),
11894 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
11895 RECUR (TREE_OPERAND (rhs, 0)),
11896 RECUR (TREE_OPERAND (rhs, 1))));
11899 incr = RECUR (incr);
11902 incr = RECUR (incr);
11906 TREE_VEC_ELT (declv, i) = decl;
11907 TREE_VEC_ELT (initv, i) = init;
11908 TREE_VEC_ELT (condv, i) = cond;
11909 TREE_VEC_ELT (incrv, i) = incr;
11913 /* Like tsubst_copy for expressions, etc. but also does semantic
11917 tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl,
11918 bool integral_constant_expression_p)
11920 #define RECUR(NODE) \
11921 tsubst_expr ((NODE), args, complain, in_decl, \
11922 integral_constant_expression_p)
11926 if (t == NULL_TREE || t == error_mark_node)
11929 if (EXPR_HAS_LOCATION (t))
11930 input_location = EXPR_LOCATION (t);
11931 if (STATEMENT_CODE_P (TREE_CODE (t)))
11932 current_stmt_tree ()->stmts_are_full_exprs_p = STMT_IS_FULL_EXPR_P (t);
11934 switch (TREE_CODE (t))
11936 case STATEMENT_LIST:
11938 tree_stmt_iterator i;
11939 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
11940 RECUR (tsi_stmt (i));
11944 case CTOR_INITIALIZER:
11945 finish_mem_initializers (tsubst_initializer_list
11946 (TREE_OPERAND (t, 0), args));
11950 finish_return_stmt (RECUR (TREE_OPERAND (t, 0)));
11954 tmp = RECUR (EXPR_STMT_EXPR (t));
11955 if (EXPR_STMT_STMT_EXPR_RESULT (t))
11956 finish_stmt_expr_expr (tmp, cur_stmt_expr);
11958 finish_expr_stmt (tmp);
11962 do_using_directive (USING_STMT_NAMESPACE (t));
11967 tree decl, pattern_decl;
11970 pattern_decl = decl = DECL_EXPR_DECL (t);
11971 if (TREE_CODE (decl) == LABEL_DECL)
11972 finish_label_decl (DECL_NAME (decl));
11973 else if (TREE_CODE (decl) == USING_DECL)
11975 tree scope = USING_DECL_SCOPE (decl);
11976 tree name = DECL_NAME (decl);
11979 scope = tsubst (scope, args, complain, in_decl);
11980 decl = lookup_qualified_name (scope, name,
11981 /*is_type_p=*/false,
11982 /*complain=*/false);
11983 if (decl == error_mark_node || TREE_CODE (decl) == TREE_LIST)
11984 qualified_name_lookup_error (scope, name, decl, input_location);
11986 do_local_using_decl (decl, scope, name);
11990 init = DECL_INITIAL (decl);
11991 decl = tsubst (decl, args, complain, in_decl);
11992 if (decl != error_mark_node)
11994 /* By marking the declaration as instantiated, we avoid
11995 trying to instantiate it. Since instantiate_decl can't
11996 handle local variables, and since we've already done
11997 all that needs to be done, that's the right thing to
11999 if (TREE_CODE (decl) == VAR_DECL)
12000 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
12001 if (TREE_CODE (decl) == VAR_DECL
12002 && ANON_AGGR_TYPE_P (TREE_TYPE (decl)))
12003 /* Anonymous aggregates are a special case. */
12004 finish_anon_union (decl);
12007 int const_init = false;
12008 maybe_push_decl (decl);
12009 if (TREE_CODE (decl) == VAR_DECL
12010 && DECL_PRETTY_FUNCTION_P (decl))
12012 /* For __PRETTY_FUNCTION__ we have to adjust the
12014 const char *const name
12015 = cxx_printable_name (current_function_decl, 2);
12016 init = cp_fname_init (name, &TREE_TYPE (decl));
12020 tree t = RECUR (init);
12024 /* If we had an initializer but it
12025 instantiated to nothing,
12026 value-initialize the object. This will
12027 only occur when the initializer was a
12028 pack expansion where the parameter packs
12029 used in that expansion were of length
12031 init = build_value_init (TREE_TYPE (decl),
12033 if (TREE_CODE (init) == AGGR_INIT_EXPR)
12034 init = get_target_expr (init);
12040 if (TREE_CODE (decl) == VAR_DECL)
12041 const_init = (DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P
12043 cp_finish_decl (decl, init, const_init, NULL_TREE, 0);
12048 /* A DECL_EXPR can also be used as an expression, in the condition
12049 clause of an if/for/while construct. */
12054 stmt = begin_for_stmt (NULL_TREE, NULL_TREE);
12055 RECUR (FOR_INIT_STMT (t));
12056 finish_for_init_stmt (stmt);
12057 tmp = RECUR (FOR_COND (t));
12058 finish_for_cond (tmp, stmt);
12059 tmp = RECUR (FOR_EXPR (t));
12060 finish_for_expr (tmp, stmt);
12061 RECUR (FOR_BODY (t));
12062 finish_for_stmt (stmt);
12065 case RANGE_FOR_STMT:
12068 stmt = begin_for_stmt (NULL_TREE, NULL_TREE);
12069 decl = RANGE_FOR_DECL (t);
12070 decl = tsubst (decl, args, complain, in_decl);
12071 maybe_push_decl (decl);
12072 expr = RECUR (RANGE_FOR_EXPR (t));
12073 stmt = cp_convert_range_for (stmt, decl, expr);
12074 RECUR (RANGE_FOR_BODY (t));
12075 finish_for_stmt (stmt);
12080 stmt = begin_while_stmt ();
12081 tmp = RECUR (WHILE_COND (t));
12082 finish_while_stmt_cond (tmp, stmt);
12083 RECUR (WHILE_BODY (t));
12084 finish_while_stmt (stmt);
12088 stmt = begin_do_stmt ();
12089 RECUR (DO_BODY (t));
12090 finish_do_body (stmt);
12091 tmp = RECUR (DO_COND (t));
12092 finish_do_stmt (tmp, stmt);
12096 stmt = begin_if_stmt ();
12097 tmp = RECUR (IF_COND (t));
12098 finish_if_stmt_cond (tmp, stmt);
12099 RECUR (THEN_CLAUSE (t));
12100 finish_then_clause (stmt);
12102 if (ELSE_CLAUSE (t))
12104 begin_else_clause (stmt);
12105 RECUR (ELSE_CLAUSE (t));
12106 finish_else_clause (stmt);
12109 finish_if_stmt (stmt);
12113 if (BIND_EXPR_BODY_BLOCK (t))
12114 stmt = begin_function_body ();
12116 stmt = begin_compound_stmt (BIND_EXPR_TRY_BLOCK (t)
12117 ? BCS_TRY_BLOCK : 0);
12119 RECUR (BIND_EXPR_BODY (t));
12121 if (BIND_EXPR_BODY_BLOCK (t))
12122 finish_function_body (stmt);
12124 finish_compound_stmt (stmt);
12128 finish_break_stmt ();
12131 case CONTINUE_STMT:
12132 finish_continue_stmt ();
12136 stmt = begin_switch_stmt ();
12137 tmp = RECUR (SWITCH_STMT_COND (t));
12138 finish_switch_cond (tmp, stmt);
12139 RECUR (SWITCH_STMT_BODY (t));
12140 finish_switch_stmt (stmt);
12143 case CASE_LABEL_EXPR:
12144 finish_case_label (EXPR_LOCATION (t),
12145 RECUR (CASE_LOW (t)),
12146 RECUR (CASE_HIGH (t)));
12151 tree decl = LABEL_EXPR_LABEL (t);
12154 label = finish_label_stmt (DECL_NAME (decl));
12155 if (DECL_ATTRIBUTES (decl) != NULL_TREE)
12156 cplus_decl_attributes (&label, DECL_ATTRIBUTES (decl), 0);
12161 tmp = GOTO_DESTINATION (t);
12162 if (TREE_CODE (tmp) != LABEL_DECL)
12163 /* Computed goto's must be tsubst'd into. On the other hand,
12164 non-computed gotos must not be; the identifier in question
12165 will have no binding. */
12168 tmp = DECL_NAME (tmp);
12169 finish_goto_stmt (tmp);
12173 tmp = finish_asm_stmt
12174 (ASM_VOLATILE_P (t),
12175 RECUR (ASM_STRING (t)),
12176 tsubst_copy_asm_operands (ASM_OUTPUTS (t), args, complain, in_decl),
12177 tsubst_copy_asm_operands (ASM_INPUTS (t), args, complain, in_decl),
12178 tsubst_copy_asm_operands (ASM_CLOBBERS (t), args, complain, in_decl),
12179 tsubst_copy_asm_operands (ASM_LABELS (t), args, complain, in_decl));
12181 tree asm_expr = tmp;
12182 if (TREE_CODE (asm_expr) == CLEANUP_POINT_EXPR)
12183 asm_expr = TREE_OPERAND (asm_expr, 0);
12184 ASM_INPUT_P (asm_expr) = ASM_INPUT_P (t);
12191 stmt = begin_try_block ();
12192 RECUR (TRY_STMTS (t));
12193 finish_cleanup_try_block (stmt);
12194 finish_cleanup (RECUR (TRY_HANDLERS (t)), stmt);
12198 tree compound_stmt = NULL_TREE;
12200 if (FN_TRY_BLOCK_P (t))
12201 stmt = begin_function_try_block (&compound_stmt);
12203 stmt = begin_try_block ();
12205 RECUR (TRY_STMTS (t));
12207 if (FN_TRY_BLOCK_P (t))
12208 finish_function_try_block (stmt);
12210 finish_try_block (stmt);
12212 RECUR (TRY_HANDLERS (t));
12213 if (FN_TRY_BLOCK_P (t))
12214 finish_function_handler_sequence (stmt, compound_stmt);
12216 finish_handler_sequence (stmt);
12222 tree decl = HANDLER_PARMS (t);
12226 decl = tsubst (decl, args, complain, in_decl);
12227 /* Prevent instantiate_decl from trying to instantiate
12228 this variable. We've already done all that needs to be
12230 if (decl != error_mark_node)
12231 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
12233 stmt = begin_handler ();
12234 finish_handler_parms (decl, stmt);
12235 RECUR (HANDLER_BODY (t));
12236 finish_handler (stmt);
12241 tsubst (TREE_TYPE (t), args, complain, NULL_TREE);
12244 case STATIC_ASSERT:
12247 tsubst_expr (STATIC_ASSERT_CONDITION (t),
12250 /*integral_constant_expression_p=*/true);
12251 finish_static_assert (condition,
12252 STATIC_ASSERT_MESSAGE (t),
12253 STATIC_ASSERT_SOURCE_LOCATION (t),
12254 /*member_p=*/false);
12259 tmp = tsubst_omp_clauses (OMP_PARALLEL_CLAUSES (t),
12260 args, complain, in_decl);
12261 stmt = begin_omp_parallel ();
12262 RECUR (OMP_PARALLEL_BODY (t));
12263 OMP_PARALLEL_COMBINED (finish_omp_parallel (tmp, stmt))
12264 = OMP_PARALLEL_COMBINED (t);
12268 tmp = tsubst_omp_clauses (OMP_TASK_CLAUSES (t),
12269 args, complain, in_decl);
12270 stmt = begin_omp_task ();
12271 RECUR (OMP_TASK_BODY (t));
12272 finish_omp_task (tmp, stmt);
12277 tree clauses, body, pre_body;
12278 tree declv, initv, condv, incrv;
12281 clauses = tsubst_omp_clauses (OMP_FOR_CLAUSES (t),
12282 args, complain, in_decl);
12283 declv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
12284 initv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
12285 condv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
12286 incrv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
12288 for (i = 0; i < TREE_VEC_LENGTH (OMP_FOR_INIT (t)); i++)
12289 tsubst_omp_for_iterator (t, i, declv, initv, condv, incrv,
12290 &clauses, args, complain, in_decl,
12291 integral_constant_expression_p);
12293 stmt = begin_omp_structured_block ();
12295 for (i = 0; i < TREE_VEC_LENGTH (initv); i++)
12296 if (TREE_VEC_ELT (initv, i) == NULL
12297 || TREE_CODE (TREE_VEC_ELT (initv, i)) != DECL_EXPR)
12298 TREE_VEC_ELT (initv, i) = RECUR (TREE_VEC_ELT (initv, i));
12299 else if (CLASS_TYPE_P (TREE_TYPE (TREE_VEC_ELT (initv, i))))
12301 tree init = RECUR (TREE_VEC_ELT (initv, i));
12302 gcc_assert (init == TREE_VEC_ELT (declv, i));
12303 TREE_VEC_ELT (initv, i) = NULL_TREE;
12307 tree decl_expr = TREE_VEC_ELT (initv, i);
12308 tree init = DECL_INITIAL (DECL_EXPR_DECL (decl_expr));
12309 gcc_assert (init != NULL);
12310 TREE_VEC_ELT (initv, i) = RECUR (init);
12311 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = NULL;
12313 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = init;
12316 pre_body = push_stmt_list ();
12317 RECUR (OMP_FOR_PRE_BODY (t));
12318 pre_body = pop_stmt_list (pre_body);
12320 body = push_stmt_list ();
12321 RECUR (OMP_FOR_BODY (t));
12322 body = pop_stmt_list (body);
12324 t = finish_omp_for (EXPR_LOCATION (t), declv, initv, condv, incrv,
12325 body, pre_body, clauses);
12327 add_stmt (finish_omp_structured_block (stmt));
12333 tmp = tsubst_omp_clauses (OMP_CLAUSES (t), args, complain, in_decl);
12334 stmt = push_stmt_list ();
12335 RECUR (OMP_BODY (t));
12336 stmt = pop_stmt_list (stmt);
12339 OMP_BODY (t) = stmt;
12340 OMP_CLAUSES (t) = tmp;
12348 stmt = push_stmt_list ();
12349 RECUR (OMP_BODY (t));
12350 stmt = pop_stmt_list (stmt);
12353 OMP_BODY (t) = stmt;
12358 gcc_assert (OMP_ATOMIC_DEPENDENT_P (t));
12360 tree op1 = TREE_OPERAND (t, 1);
12361 tree lhs = RECUR (TREE_OPERAND (op1, 0));
12362 tree rhs = RECUR (TREE_OPERAND (op1, 1));
12363 finish_omp_atomic (TREE_CODE (op1), lhs, rhs);
12367 case EXPR_PACK_EXPANSION:
12368 error ("invalid use of pack expansion expression");
12369 return error_mark_node;
12371 case NONTYPE_ARGUMENT_PACK:
12372 error ("use %<...%> to expand argument pack");
12373 return error_mark_node;
12376 gcc_assert (!STATEMENT_CODE_P (TREE_CODE (t)));
12378 return tsubst_copy_and_build (t, args, complain, in_decl,
12379 /*function_p=*/false,
12380 integral_constant_expression_p);
12387 /* T is a postfix-expression that is not being used in a function
12388 call. Return the substituted version of T. */
12391 tsubst_non_call_postfix_expression (tree t, tree args,
12392 tsubst_flags_t complain,
12395 if (TREE_CODE (t) == SCOPE_REF)
12396 t = tsubst_qualified_id (t, args, complain, in_decl,
12397 /*done=*/false, /*address_p=*/false);
12399 t = tsubst_copy_and_build (t, args, complain, in_decl,
12400 /*function_p=*/false,
12401 /*integral_constant_expression_p=*/false);
12406 /* Like tsubst but deals with expressions and performs semantic
12407 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
12410 tsubst_copy_and_build (tree t,
12412 tsubst_flags_t complain,
12415 bool integral_constant_expression_p)
12417 #define RECUR(NODE) \
12418 tsubst_copy_and_build (NODE, args, complain, in_decl, \
12419 /*function_p=*/false, \
12420 integral_constant_expression_p)
12424 if (t == NULL_TREE || t == error_mark_node)
12427 switch (TREE_CODE (t))
12431 /* Fall through. */
12432 case IDENTIFIER_NODE:
12436 bool non_integral_constant_expression_p;
12437 const char *error_msg;
12439 if (IDENTIFIER_TYPENAME_P (t))
12441 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12442 t = mangle_conv_op_name_for_type (new_type);
12445 /* Look up the name. */
12446 decl = lookup_name (t);
12448 /* By convention, expressions use ERROR_MARK_NODE to indicate
12449 failure, not NULL_TREE. */
12450 if (decl == NULL_TREE)
12451 decl = error_mark_node;
12453 decl = finish_id_expression (t, decl, NULL_TREE,
12455 integral_constant_expression_p,
12456 /*allow_non_integral_constant_expression_p=*/false,
12457 &non_integral_constant_expression_p,
12458 /*template_p=*/false,
12460 /*address_p=*/false,
12461 /*template_arg_p=*/false,
12466 if (!function_p && TREE_CODE (decl) == IDENTIFIER_NODE)
12467 decl = unqualified_name_lookup_error (decl);
12471 case TEMPLATE_ID_EXPR:
12474 tree templ = RECUR (TREE_OPERAND (t, 0));
12475 tree targs = TREE_OPERAND (t, 1);
12478 targs = tsubst_template_args (targs, args, complain, in_decl);
12480 if (TREE_CODE (templ) == COMPONENT_REF)
12482 object = TREE_OPERAND (templ, 0);
12483 templ = TREE_OPERAND (templ, 1);
12486 object = NULL_TREE;
12487 templ = lookup_template_function (templ, targs);
12490 return build3 (COMPONENT_REF, TREE_TYPE (templ),
12491 object, templ, NULL_TREE);
12493 return baselink_for_fns (templ);
12498 tree r = RECUR (TREE_OPERAND (t, 0));
12500 if (REFERENCE_REF_P (t))
12502 /* A type conversion to reference type will be enclosed in
12503 such an indirect ref, but the substitution of the cast
12504 will have also added such an indirect ref. */
12505 if (TREE_CODE (TREE_TYPE (r)) == REFERENCE_TYPE)
12506 r = convert_from_reference (r);
12509 r = build_x_indirect_ref (r, RO_UNARY_STAR, complain);
12515 (tsubst (TREE_TYPE (t), args, complain, in_decl),
12516 RECUR (TREE_OPERAND (t, 0)));
12519 case REINTERPRET_CAST_EXPR:
12520 case CONST_CAST_EXPR:
12521 case DYNAMIC_CAST_EXPR:
12522 case STATIC_CAST_EXPR:
12527 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12528 if (integral_constant_expression_p
12529 && !cast_valid_in_integral_constant_expression_p (type))
12531 if (complain & tf_error)
12532 error ("a cast to a type other than an integral or "
12533 "enumeration type cannot appear in a constant-expression");
12534 return error_mark_node;
12537 op = RECUR (TREE_OPERAND (t, 0));
12539 switch (TREE_CODE (t))
12542 return build_functional_cast (type, op, complain);
12543 case REINTERPRET_CAST_EXPR:
12544 return build_reinterpret_cast (type, op, complain);
12545 case CONST_CAST_EXPR:
12546 return build_const_cast (type, op, complain);
12547 case DYNAMIC_CAST_EXPR:
12548 return build_dynamic_cast (type, op, complain);
12549 case STATIC_CAST_EXPR:
12550 return build_static_cast (type, op, complain);
12552 gcc_unreachable ();
12556 case POSTDECREMENT_EXPR:
12557 case POSTINCREMENT_EXPR:
12558 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
12559 args, complain, in_decl);
12560 return build_x_unary_op (TREE_CODE (t), op1, complain);
12562 case PREDECREMENT_EXPR:
12563 case PREINCREMENT_EXPR:
12567 case TRUTH_NOT_EXPR:
12568 case UNARY_PLUS_EXPR: /* Unary + */
12569 case REALPART_EXPR:
12570 case IMAGPART_EXPR:
12571 return build_x_unary_op (TREE_CODE (t), RECUR (TREE_OPERAND (t, 0)),
12575 op1 = TREE_OPERAND (t, 0);
12576 if (TREE_CODE (op1) == LABEL_DECL)
12577 return finish_label_address_expr (DECL_NAME (op1),
12578 EXPR_LOCATION (op1));
12579 if (TREE_CODE (op1) == SCOPE_REF)
12580 op1 = tsubst_qualified_id (op1, args, complain, in_decl,
12581 /*done=*/true, /*address_p=*/true);
12583 op1 = tsubst_non_call_postfix_expression (op1, args, complain,
12585 return build_x_unary_op (ADDR_EXPR, op1, complain);
12590 case TRUNC_DIV_EXPR:
12591 case CEIL_DIV_EXPR:
12592 case FLOOR_DIV_EXPR:
12593 case ROUND_DIV_EXPR:
12594 case EXACT_DIV_EXPR:
12598 case TRUNC_MOD_EXPR:
12599 case FLOOR_MOD_EXPR:
12600 case TRUTH_ANDIF_EXPR:
12601 case TRUTH_ORIF_EXPR:
12602 case TRUTH_AND_EXPR:
12603 case TRUTH_OR_EXPR:
12618 return build_x_binary_op
12620 RECUR (TREE_OPERAND (t, 0)),
12621 (TREE_NO_WARNING (TREE_OPERAND (t, 0))
12623 : TREE_CODE (TREE_OPERAND (t, 0))),
12624 RECUR (TREE_OPERAND (t, 1)),
12625 (TREE_NO_WARNING (TREE_OPERAND (t, 1))
12627 : TREE_CODE (TREE_OPERAND (t, 1))),
12628 /*overloaded_p=*/NULL,
12632 return tsubst_qualified_id (t, args, complain, in_decl, /*done=*/true,
12633 /*address_p=*/false);
12635 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
12636 args, complain, in_decl);
12637 return build_x_array_ref (op1, RECUR (TREE_OPERAND (t, 1)), complain);
12640 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
12641 return tsubst_copy (t, args, complain, in_decl);
12645 op1 = TREE_OPERAND (t, 0);
12648 /* When there are no ARGS, we are trying to evaluate a
12649 non-dependent expression from the parser. Trying to do
12650 the substitutions may not work. */
12652 op1 = TREE_TYPE (op1);
12656 ++cp_unevaluated_operand;
12657 ++c_inhibit_evaluation_warnings;
12658 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
12659 /*function_p=*/false,
12660 /*integral_constant_expression_p=*/false);
12661 --cp_unevaluated_operand;
12662 --c_inhibit_evaluation_warnings;
12665 return cxx_sizeof_or_alignof_type (op1, TREE_CODE (t),
12666 complain & tf_error);
12668 return cxx_sizeof_or_alignof_expr (op1, TREE_CODE (t),
12669 complain & tf_error);
12671 case AT_ENCODE_EXPR:
12673 op1 = TREE_OPERAND (t, 0);
12674 ++cp_unevaluated_operand;
12675 ++c_inhibit_evaluation_warnings;
12676 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
12677 /*function_p=*/false,
12678 /*integral_constant_expression_p=*/false);
12679 --cp_unevaluated_operand;
12680 --c_inhibit_evaluation_warnings;
12681 return objc_build_encode_expr (op1);
12684 case NOEXCEPT_EXPR:
12685 op1 = TREE_OPERAND (t, 0);
12686 ++cp_unevaluated_operand;
12687 ++c_inhibit_evaluation_warnings;
12688 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
12689 /*function_p=*/false,
12690 /*integral_constant_expression_p=*/false);
12691 --cp_unevaluated_operand;
12692 --c_inhibit_evaluation_warnings;
12693 return finish_noexcept_expr (op1, complain);
12697 tree r = build_x_modify_expr
12698 (RECUR (TREE_OPERAND (t, 0)),
12699 TREE_CODE (TREE_OPERAND (t, 1)),
12700 RECUR (TREE_OPERAND (t, 2)),
12702 /* TREE_NO_WARNING must be set if either the expression was
12703 parenthesized or it uses an operator such as >>= rather
12704 than plain assignment. In the former case, it was already
12705 set and must be copied. In the latter case,
12706 build_x_modify_expr sets it and it must not be reset
12708 if (TREE_NO_WARNING (t))
12709 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
12714 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
12715 args, complain, in_decl);
12716 /* Remember that there was a reference to this entity. */
12719 return build_x_arrow (op1);
12723 tree placement = RECUR (TREE_OPERAND (t, 0));
12724 tree init = RECUR (TREE_OPERAND (t, 3));
12725 VEC(tree,gc) *placement_vec;
12726 VEC(tree,gc) *init_vec;
12729 if (placement == NULL_TREE)
12730 placement_vec = NULL;
12733 placement_vec = make_tree_vector ();
12734 for (; placement != NULL_TREE; placement = TREE_CHAIN (placement))
12735 VEC_safe_push (tree, gc, placement_vec, TREE_VALUE (placement));
12738 /* If there was an initializer in the original tree, but it
12739 instantiated to an empty list, then we should pass a
12740 non-NULL empty vector to tell build_new that it was an
12741 empty initializer() rather than no initializer. This can
12742 only happen when the initializer is a pack expansion whose
12743 parameter packs are of length zero. */
12744 if (init == NULL_TREE && TREE_OPERAND (t, 3) == NULL_TREE)
12748 init_vec = make_tree_vector ();
12749 if (init == void_zero_node)
12750 gcc_assert (init_vec != NULL);
12753 for (; init != NULL_TREE; init = TREE_CHAIN (init))
12754 VEC_safe_push (tree, gc, init_vec, TREE_VALUE (init));
12758 ret = build_new (&placement_vec,
12759 tsubst (TREE_OPERAND (t, 1), args, complain, in_decl),
12760 RECUR (TREE_OPERAND (t, 2)),
12762 NEW_EXPR_USE_GLOBAL (t),
12765 if (placement_vec != NULL)
12766 release_tree_vector (placement_vec);
12767 if (init_vec != NULL)
12768 release_tree_vector (init_vec);
12774 return delete_sanity
12775 (RECUR (TREE_OPERAND (t, 0)),
12776 RECUR (TREE_OPERAND (t, 1)),
12777 DELETE_EXPR_USE_VEC (t),
12778 DELETE_EXPR_USE_GLOBAL (t));
12780 case COMPOUND_EXPR:
12781 return build_x_compound_expr (RECUR (TREE_OPERAND (t, 0)),
12782 RECUR (TREE_OPERAND (t, 1)),
12788 VEC(tree,gc) *call_args;
12789 unsigned int nargs, i;
12794 function = CALL_EXPR_FN (t);
12795 /* When we parsed the expression, we determined whether or
12796 not Koenig lookup should be performed. */
12797 koenig_p = KOENIG_LOOKUP_P (t);
12798 if (TREE_CODE (function) == SCOPE_REF)
12800 qualified_p = true;
12801 function = tsubst_qualified_id (function, args, complain, in_decl,
12803 /*address_p=*/false);
12807 if (TREE_CODE (function) == COMPONENT_REF)
12809 tree op = TREE_OPERAND (function, 1);
12811 qualified_p = (TREE_CODE (op) == SCOPE_REF
12812 || (BASELINK_P (op)
12813 && BASELINK_QUALIFIED_P (op)));
12816 qualified_p = false;
12818 function = tsubst_copy_and_build (function, args, complain,
12821 integral_constant_expression_p);
12823 if (BASELINK_P (function))
12824 qualified_p = true;
12827 nargs = call_expr_nargs (t);
12828 call_args = make_tree_vector ();
12829 for (i = 0; i < nargs; ++i)
12831 tree arg = CALL_EXPR_ARG (t, i);
12833 if (!PACK_EXPANSION_P (arg))
12834 VEC_safe_push (tree, gc, call_args,
12835 RECUR (CALL_EXPR_ARG (t, i)));
12838 /* Expand the pack expansion and push each entry onto
12840 arg = tsubst_pack_expansion (arg, args, complain, in_decl);
12841 if (TREE_CODE (arg) == TREE_VEC)
12843 unsigned int len, j;
12845 len = TREE_VEC_LENGTH (arg);
12846 for (j = 0; j < len; ++j)
12848 tree value = TREE_VEC_ELT (arg, j);
12849 if (value != NULL_TREE)
12850 value = convert_from_reference (value);
12851 VEC_safe_push (tree, gc, call_args, value);
12856 /* A partial substitution. Add one entry. */
12857 VEC_safe_push (tree, gc, call_args, arg);
12862 /* We do not perform argument-dependent lookup if normal
12863 lookup finds a non-function, in accordance with the
12864 expected resolution of DR 218. */
12866 && ((is_overloaded_fn (function)
12867 /* If lookup found a member function, the Koenig lookup is
12868 not appropriate, even if an unqualified-name was used
12869 to denote the function. */
12870 && !DECL_FUNCTION_MEMBER_P (get_first_fn (function)))
12871 || TREE_CODE (function) == IDENTIFIER_NODE)
12872 /* Only do this when substitution turns a dependent call
12873 into a non-dependent call. */
12874 && type_dependent_expression_p_push (t)
12875 && !any_type_dependent_arguments_p (call_args))
12876 function = perform_koenig_lookup (function, call_args, false);
12878 if (TREE_CODE (function) == IDENTIFIER_NODE)
12880 unqualified_name_lookup_error (function);
12881 release_tree_vector (call_args);
12882 return error_mark_node;
12885 /* Remember that there was a reference to this entity. */
12886 if (DECL_P (function))
12887 mark_used (function);
12889 if (TREE_CODE (function) == OFFSET_REF)
12890 ret = build_offset_ref_call_from_tree (function, &call_args);
12891 else if (TREE_CODE (function) == COMPONENT_REF)
12893 tree instance = TREE_OPERAND (function, 0);
12894 tree fn = TREE_OPERAND (function, 1);
12896 if (processing_template_decl
12897 && (type_dependent_expression_p (instance)
12898 || (!BASELINK_P (fn)
12899 && TREE_CODE (fn) != FIELD_DECL)
12900 || type_dependent_expression_p (fn)
12901 || any_type_dependent_arguments_p (call_args)))
12902 ret = build_nt_call_vec (function, call_args);
12903 else if (!BASELINK_P (fn))
12904 ret = finish_call_expr (function, &call_args,
12905 /*disallow_virtual=*/false,
12906 /*koenig_p=*/false,
12909 ret = (build_new_method_call
12911 &call_args, NULL_TREE,
12912 qualified_p ? LOOKUP_NONVIRTUAL : LOOKUP_NORMAL,
12917 ret = finish_call_expr (function, &call_args,
12918 /*disallow_virtual=*/qualified_p,
12922 release_tree_vector (call_args);
12928 return build_x_conditional_expr
12929 (RECUR (TREE_OPERAND (t, 0)),
12930 RECUR (TREE_OPERAND (t, 1)),
12931 RECUR (TREE_OPERAND (t, 2)),
12934 case PSEUDO_DTOR_EXPR:
12935 return finish_pseudo_destructor_expr
12936 (RECUR (TREE_OPERAND (t, 0)),
12937 RECUR (TREE_OPERAND (t, 1)),
12938 RECUR (TREE_OPERAND (t, 2)));
12942 tree purpose, value, chain;
12944 if (t == void_list_node)
12947 if ((TREE_PURPOSE (t) && PACK_EXPANSION_P (TREE_PURPOSE (t)))
12948 || (TREE_VALUE (t) && PACK_EXPANSION_P (TREE_VALUE (t))))
12950 /* We have pack expansions, so expand those and
12951 create a new list out of it. */
12952 tree purposevec = NULL_TREE;
12953 tree valuevec = NULL_TREE;
12957 /* Expand the argument expressions. */
12958 if (TREE_PURPOSE (t))
12959 purposevec = tsubst_pack_expansion (TREE_PURPOSE (t), args,
12960 complain, in_decl);
12961 if (TREE_VALUE (t))
12962 valuevec = tsubst_pack_expansion (TREE_VALUE (t), args,
12963 complain, in_decl);
12965 /* Build the rest of the list. */
12966 chain = TREE_CHAIN (t);
12967 if (chain && chain != void_type_node)
12968 chain = RECUR (chain);
12970 /* Determine the number of arguments. */
12971 if (purposevec && TREE_CODE (purposevec) == TREE_VEC)
12973 len = TREE_VEC_LENGTH (purposevec);
12974 gcc_assert (!valuevec || len == TREE_VEC_LENGTH (valuevec));
12976 else if (TREE_CODE (valuevec) == TREE_VEC)
12977 len = TREE_VEC_LENGTH (valuevec);
12980 /* Since we only performed a partial substitution into
12981 the argument pack, we only return a single list
12983 if (purposevec == TREE_PURPOSE (t)
12984 && valuevec == TREE_VALUE (t)
12985 && chain == TREE_CHAIN (t))
12988 return tree_cons (purposevec, valuevec, chain);
12991 /* Convert the argument vectors into a TREE_LIST */
12995 /* Grab the Ith values. */
12997 purpose = purposevec ? TREE_VEC_ELT (purposevec, i)
13000 = valuevec ? convert_from_reference (TREE_VEC_ELT (valuevec, i))
13003 /* Build the list (backwards). */
13004 chain = tree_cons (purpose, value, chain);
13010 purpose = TREE_PURPOSE (t);
13012 purpose = RECUR (purpose);
13013 value = TREE_VALUE (t);
13015 value = RECUR (value);
13016 chain = TREE_CHAIN (t);
13017 if (chain && chain != void_type_node)
13018 chain = RECUR (chain);
13019 if (purpose == TREE_PURPOSE (t)
13020 && value == TREE_VALUE (t)
13021 && chain == TREE_CHAIN (t))
13023 return tree_cons (purpose, value, chain);
13026 case COMPONENT_REF:
13032 object = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
13033 args, complain, in_decl);
13034 /* Remember that there was a reference to this entity. */
13035 if (DECL_P (object))
13036 mark_used (object);
13037 object_type = TREE_TYPE (object);
13039 member = TREE_OPERAND (t, 1);
13040 if (BASELINK_P (member))
13041 member = tsubst_baselink (member,
13042 non_reference (TREE_TYPE (object)),
13043 args, complain, in_decl);
13045 member = tsubst_copy (member, args, complain, in_decl);
13046 if (member == error_mark_node)
13047 return error_mark_node;
13049 if (object_type && !CLASS_TYPE_P (object_type))
13051 if (SCALAR_TYPE_P (object_type))
13053 tree s = NULL_TREE;
13054 tree dtor = member;
13056 if (TREE_CODE (dtor) == SCOPE_REF)
13058 s = TREE_OPERAND (dtor, 0);
13059 dtor = TREE_OPERAND (dtor, 1);
13061 if (TREE_CODE (dtor) == BIT_NOT_EXPR)
13063 dtor = TREE_OPERAND (dtor, 0);
13065 return finish_pseudo_destructor_expr (object, s, dtor);
13069 else if (TREE_CODE (member) == SCOPE_REF
13070 && TREE_CODE (TREE_OPERAND (member, 1)) == TEMPLATE_ID_EXPR)
13075 /* Lookup the template functions now that we know what the
13077 tmpl = TREE_OPERAND (TREE_OPERAND (member, 1), 0);
13078 args = TREE_OPERAND (TREE_OPERAND (member, 1), 1);
13079 member = lookup_qualified_name (TREE_OPERAND (member, 0), tmpl,
13080 /*is_type_p=*/false,
13081 /*complain=*/false);
13082 if (BASELINK_P (member))
13084 BASELINK_FUNCTIONS (member)
13085 = build_nt (TEMPLATE_ID_EXPR, BASELINK_FUNCTIONS (member),
13087 member = (adjust_result_of_qualified_name_lookup
13088 (member, BINFO_TYPE (BASELINK_BINFO (member)),
13093 qualified_name_lookup_error (object_type, tmpl, member,
13095 return error_mark_node;
13098 else if (TREE_CODE (member) == SCOPE_REF
13099 && !CLASS_TYPE_P (TREE_OPERAND (member, 0))
13100 && TREE_CODE (TREE_OPERAND (member, 0)) != NAMESPACE_DECL)
13102 if (complain & tf_error)
13104 if (TYPE_P (TREE_OPERAND (member, 0)))
13105 error ("%qT is not a class or namespace",
13106 TREE_OPERAND (member, 0));
13108 error ("%qD is not a class or namespace",
13109 TREE_OPERAND (member, 0));
13111 return error_mark_node;
13113 else if (TREE_CODE (member) == FIELD_DECL)
13114 return finish_non_static_data_member (member, object, NULL_TREE);
13116 return finish_class_member_access_expr (object, member,
13117 /*template_p=*/false,
13123 (RECUR (TREE_OPERAND (t, 0)));
13127 VEC(constructor_elt,gc) *n;
13128 constructor_elt *ce;
13129 unsigned HOST_WIDE_INT idx;
13130 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
13131 bool process_index_p;
13133 bool need_copy_p = false;
13136 if (type == error_mark_node)
13137 return error_mark_node;
13139 /* digest_init will do the wrong thing if we let it. */
13140 if (type && TYPE_PTRMEMFUNC_P (type))
13143 /* We do not want to process the index of aggregate
13144 initializers as they are identifier nodes which will be
13145 looked up by digest_init. */
13146 process_index_p = !(type && MAYBE_CLASS_TYPE_P (type));
13148 n = VEC_copy (constructor_elt, gc, CONSTRUCTOR_ELTS (t));
13149 newlen = VEC_length (constructor_elt, n);
13150 FOR_EACH_VEC_ELT (constructor_elt, n, idx, ce)
13152 if (ce->index && process_index_p)
13153 ce->index = RECUR (ce->index);
13155 if (PACK_EXPANSION_P (ce->value))
13157 /* Substitute into the pack expansion. */
13158 ce->value = tsubst_pack_expansion (ce->value, args, complain,
13161 if (ce->value == error_mark_node)
13163 else if (TREE_VEC_LENGTH (ce->value) == 1)
13164 /* Just move the argument into place. */
13165 ce->value = TREE_VEC_ELT (ce->value, 0);
13168 /* Update the length of the final CONSTRUCTOR
13169 arguments vector, and note that we will need to
13171 newlen = newlen + TREE_VEC_LENGTH (ce->value) - 1;
13172 need_copy_p = true;
13176 ce->value = RECUR (ce->value);
13181 VEC(constructor_elt,gc) *old_n = n;
13183 n = VEC_alloc (constructor_elt, gc, newlen);
13184 FOR_EACH_VEC_ELT (constructor_elt, old_n, idx, ce)
13186 if (TREE_CODE (ce->value) == TREE_VEC)
13188 int i, len = TREE_VEC_LENGTH (ce->value);
13189 for (i = 0; i < len; ++i)
13190 CONSTRUCTOR_APPEND_ELT (n, 0,
13191 TREE_VEC_ELT (ce->value, i));
13194 CONSTRUCTOR_APPEND_ELT (n, 0, ce->value);
13198 r = build_constructor (init_list_type_node, n);
13199 CONSTRUCTOR_IS_DIRECT_INIT (r) = CONSTRUCTOR_IS_DIRECT_INIT (t);
13201 if (TREE_HAS_CONSTRUCTOR (t))
13202 return finish_compound_literal (type, r);
13204 TREE_TYPE (r) = type;
13210 tree operand_0 = TREE_OPERAND (t, 0);
13211 if (TYPE_P (operand_0))
13213 operand_0 = tsubst (operand_0, args, complain, in_decl);
13214 return get_typeid (operand_0);
13218 operand_0 = RECUR (operand_0);
13219 return build_typeid (operand_0);
13230 tree r = tsubst_copy (t, args, complain, in_decl);
13232 if (TREE_CODE (TREE_TYPE (t)) != REFERENCE_TYPE)
13233 /* If the original type was a reference, we'll be wrapped in
13234 the appropriate INDIRECT_REF. */
13235 r = convert_from_reference (r);
13240 return build_x_va_arg (RECUR (TREE_OPERAND (t, 0)),
13241 tsubst (TREE_TYPE (t), args, complain, in_decl));
13243 case OFFSETOF_EXPR:
13244 return finish_offsetof (RECUR (TREE_OPERAND (t, 0)));
13248 tree type1 = tsubst_copy (TRAIT_EXPR_TYPE1 (t), args,
13249 complain, in_decl);
13251 tree type2 = TRAIT_EXPR_TYPE2 (t);
13253 type2 = tsubst_copy (type2, args, complain, in_decl);
13255 return finish_trait_expr (TRAIT_EXPR_KIND (t), type1, type2);
13260 tree old_stmt_expr = cur_stmt_expr;
13261 tree stmt_expr = begin_stmt_expr ();
13263 cur_stmt_expr = stmt_expr;
13264 tsubst_expr (STMT_EXPR_STMT (t), args, complain, in_decl,
13265 integral_constant_expression_p);
13266 stmt_expr = finish_stmt_expr (stmt_expr, false);
13267 cur_stmt_expr = old_stmt_expr;
13269 /* If the resulting list of expression statement is empty,
13270 fold it further into void_zero_node. */
13271 if (empty_expr_stmt_p (stmt_expr))
13272 stmt_expr = void_zero_node;
13278 t = tsubst_copy (t, args, complain, in_decl);
13279 /* As in finish_id_expression, we resolve enumeration constants
13280 to their underlying values. */
13281 if (TREE_CODE (t) == CONST_DECL)
13283 used_types_insert (TREE_TYPE (t));
13284 return DECL_INITIAL (t);
13290 tree r = build_lambda_expr ();
13292 tree type = tsubst (TREE_TYPE (t), args, complain, NULL_TREE);
13293 TREE_TYPE (r) = type;
13294 CLASSTYPE_LAMBDA_EXPR (type) = r;
13296 LAMBDA_EXPR_LOCATION (r)
13297 = LAMBDA_EXPR_LOCATION (t);
13298 LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (r)
13299 = LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (t);
13300 LAMBDA_EXPR_MUTABLE_P (r) = LAMBDA_EXPR_MUTABLE_P (t);
13301 LAMBDA_EXPR_DISCRIMINATOR (r)
13302 = (LAMBDA_EXPR_DISCRIMINATOR (t));
13303 LAMBDA_EXPR_CAPTURE_LIST (r)
13304 = RECUR (LAMBDA_EXPR_CAPTURE_LIST (t));
13305 LAMBDA_EXPR_THIS_CAPTURE (r)
13306 = RECUR (LAMBDA_EXPR_THIS_CAPTURE (t));
13307 LAMBDA_EXPR_EXTRA_SCOPE (r)
13308 = RECUR (LAMBDA_EXPR_EXTRA_SCOPE (t));
13310 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
13311 determine_visibility (TYPE_NAME (type));
13312 /* Now that we know visibility, instantiate the type so we have a
13313 declaration of the op() for later calls to lambda_function. */
13314 complete_type (type);
13316 type = tsubst (LAMBDA_EXPR_RETURN_TYPE (t), args, complain, in_decl);
13318 apply_lambda_return_type (r, type);
13320 return build_lambda_object (r);
13324 /* We can get here for a constant initializer of non-dependent type.
13325 FIXME stop folding in cp_parser_initializer_clause. */
13326 gcc_assert (TREE_CONSTANT (t));
13327 return get_target_expr (RECUR (TARGET_EXPR_INITIAL (t)));
13330 /* Handle Objective-C++ constructs, if appropriate. */
13333 = objcp_tsubst_copy_and_build (t, args, complain,
13334 in_decl, /*function_p=*/false);
13338 return tsubst_copy (t, args, complain, in_decl);
13344 /* Verify that the instantiated ARGS are valid. For type arguments,
13345 make sure that the type's linkage is ok. For non-type arguments,
13346 make sure they are constants if they are integral or enumerations.
13347 Emit an error under control of COMPLAIN, and return TRUE on error. */
13350 check_instantiated_arg (tree tmpl, tree t, tsubst_flags_t complain)
13352 if (ARGUMENT_PACK_P (t))
13354 tree vec = ARGUMENT_PACK_ARGS (t);
13355 int len = TREE_VEC_LENGTH (vec);
13356 bool result = false;
13359 for (i = 0; i < len; ++i)
13360 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (vec, i), complain))
13364 else if (TYPE_P (t))
13366 /* [basic.link]: A name with no linkage (notably, the name
13367 of a class or enumeration declared in a local scope)
13368 shall not be used to declare an entity with linkage.
13369 This implies that names with no linkage cannot be used as
13372 DR 757 relaxes this restriction for C++0x. */
13373 tree nt = (cxx_dialect > cxx98 ? NULL_TREE
13374 : no_linkage_check (t, /*relaxed_p=*/false));
13378 /* DR 488 makes use of a type with no linkage cause
13379 type deduction to fail. */
13380 if (complain & tf_error)
13382 if (TYPE_ANONYMOUS_P (nt))
13383 error ("%qT is/uses anonymous type", t);
13385 error ("template argument for %qD uses local type %qT",
13390 /* In order to avoid all sorts of complications, we do not
13391 allow variably-modified types as template arguments. */
13392 else if (variably_modified_type_p (t, NULL_TREE))
13394 if (complain & tf_error)
13395 error ("%qT is a variably modified type", t);
13399 /* A non-type argument of integral or enumerated type must be a
13401 else if (TREE_TYPE (t)
13402 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t))
13403 && !TREE_CONSTANT (t))
13405 if (complain & tf_error)
13406 error ("integral expression %qE is not constant", t);
13413 check_instantiated_args (tree tmpl, tree args, tsubst_flags_t complain)
13415 int ix, len = DECL_NTPARMS (tmpl);
13416 bool result = false;
13418 for (ix = 0; ix != len; ix++)
13420 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (args, ix), complain))
13423 if (result && (complain & tf_error))
13424 error (" trying to instantiate %qD", tmpl);
13428 /* Instantiate the indicated variable or function template TMPL with
13429 the template arguments in TARG_PTR. */
13432 instantiate_template (tree tmpl, tree orig_args, tsubst_flags_t complain)
13434 tree targ_ptr = orig_args;
13438 HOST_WIDE_INT saved_processing_template_decl;
13440 if (tmpl == error_mark_node)
13441 return error_mark_node;
13443 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
13445 /* If this function is a clone, handle it specially. */
13446 if (DECL_CLONED_FUNCTION_P (tmpl))
13451 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
13452 DECL_CLONED_FUNCTION. */
13453 spec = instantiate_template (DECL_ABSTRACT_ORIGIN (tmpl),
13454 targ_ptr, complain);
13455 if (spec == error_mark_node)
13456 return error_mark_node;
13458 /* Look for the clone. */
13459 FOR_EACH_CLONE (clone, spec)
13460 if (DECL_NAME (clone) == DECL_NAME (tmpl))
13462 /* We should always have found the clone by now. */
13463 gcc_unreachable ();
13467 /* Check to see if we already have this specialization. */
13468 gen_tmpl = most_general_template (tmpl);
13469 if (tmpl != gen_tmpl)
13470 /* The TMPL is a partial instantiation. To get a full set of
13471 arguments we must add the arguments used to perform the
13472 partial instantiation. */
13473 targ_ptr = add_outermost_template_args (DECL_TI_ARGS (tmpl),
13476 /* It would be nice to avoid hashing here and then again in tsubst_decl,
13477 but it doesn't seem to be on the hot path. */
13478 spec = retrieve_specialization (gen_tmpl, targ_ptr, 0);
13480 gcc_assert (tmpl == gen_tmpl
13481 || ((fndecl = retrieve_specialization (tmpl, orig_args, 0))
13483 || fndecl == NULL_TREE);
13485 if (spec != NULL_TREE)
13488 if (check_instantiated_args (gen_tmpl, INNERMOST_TEMPLATE_ARGS (targ_ptr),
13490 return error_mark_node;
13492 /* We are building a FUNCTION_DECL, during which the access of its
13493 parameters and return types have to be checked. However this
13494 FUNCTION_DECL which is the desired context for access checking
13495 is not built yet. We solve this chicken-and-egg problem by
13496 deferring all checks until we have the FUNCTION_DECL. */
13497 push_deferring_access_checks (dk_deferred);
13499 /* Although PROCESSING_TEMPLATE_DECL may be true at this point
13500 (because, for example, we have encountered a non-dependent
13501 function call in the body of a template function and must now
13502 determine which of several overloaded functions will be called),
13503 within the instantiation itself we are not processing a
13505 saved_processing_template_decl = processing_template_decl;
13506 processing_template_decl = 0;
13507 /* Substitute template parameters to obtain the specialization. */
13508 fndecl = tsubst (DECL_TEMPLATE_RESULT (gen_tmpl),
13509 targ_ptr, complain, gen_tmpl);
13510 processing_template_decl = saved_processing_template_decl;
13511 if (fndecl == error_mark_node)
13512 return error_mark_node;
13514 /* Now we know the specialization, compute access previously
13516 push_access_scope (fndecl);
13518 /* Some typedefs referenced from within the template code need to be access
13519 checked at template instantiation time, i.e now. These types were
13520 added to the template at parsing time. Let's get those and perfom
13521 the acces checks then. */
13522 perform_typedefs_access_check (DECL_TEMPLATE_RESULT (tmpl), targ_ptr);
13523 perform_deferred_access_checks ();
13524 pop_access_scope (fndecl);
13525 pop_deferring_access_checks ();
13527 /* The DECL_TI_TEMPLATE should always be the immediate parent
13528 template, not the most general template. */
13529 DECL_TI_TEMPLATE (fndecl) = tmpl;
13531 /* If we've just instantiated the main entry point for a function,
13532 instantiate all the alternate entry points as well. We do this
13533 by cloning the instantiation of the main entry point, not by
13534 instantiating the template clones. */
13535 if (DECL_CHAIN (gen_tmpl) && DECL_CLONED_FUNCTION_P (DECL_CHAIN (gen_tmpl)))
13536 clone_function_decl (fndecl, /*update_method_vec_p=*/0);
13541 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
13542 NARGS elements of the arguments that are being used when calling
13543 it. TARGS is a vector into which the deduced template arguments
13546 Return zero for success, 2 for an incomplete match that doesn't resolve
13547 all the types, and 1 for complete failure. An error message will be
13548 printed only for an incomplete match.
13550 If FN is a conversion operator, or we are trying to produce a specific
13551 specialization, RETURN_TYPE is the return type desired.
13553 The EXPLICIT_TARGS are explicit template arguments provided via a
13556 The parameter STRICT is one of:
13559 We are deducing arguments for a function call, as in
13560 [temp.deduct.call].
13563 We are deducing arguments for a conversion function, as in
13564 [temp.deduct.conv].
13567 We are deducing arguments when doing an explicit instantiation
13568 as in [temp.explicit], when determining an explicit specialization
13569 as in [temp.expl.spec], or when taking the address of a function
13570 template, as in [temp.deduct.funcaddr]. */
13573 fn_type_unification (tree fn,
13574 tree explicit_targs,
13577 unsigned int nargs,
13579 unification_kind_t strict,
13585 bool incomplete_argument_packs_p = false;
13587 gcc_assert (TREE_CODE (fn) == TEMPLATE_DECL);
13589 fntype = TREE_TYPE (fn);
13590 if (explicit_targs)
13594 The specified template arguments must match the template
13595 parameters in kind (i.e., type, nontype, template), and there
13596 must not be more arguments than there are parameters;
13597 otherwise type deduction fails.
13599 Nontype arguments must match the types of the corresponding
13600 nontype template parameters, or must be convertible to the
13601 types of the corresponding nontype parameters as specified in
13602 _temp.arg.nontype_, otherwise type deduction fails.
13604 All references in the function type of the function template
13605 to the corresponding template parameters are replaced by the
13606 specified template argument values. If a substitution in a
13607 template parameter or in the function type of the function
13608 template results in an invalid type, type deduction fails. */
13609 tree tparms = DECL_INNERMOST_TEMPLATE_PARMS (fn);
13610 int i, len = TREE_VEC_LENGTH (tparms);
13611 tree converted_args;
13612 bool incomplete = false;
13614 if (explicit_targs == error_mark_node)
13618 = (coerce_template_parms (tparms, explicit_targs, NULL_TREE, tf_none,
13619 /*require_all_args=*/false,
13620 /*use_default_args=*/false));
13621 if (converted_args == error_mark_node)
13624 /* Substitute the explicit args into the function type. This is
13625 necessary so that, for instance, explicitly declared function
13626 arguments can match null pointed constants. If we were given
13627 an incomplete set of explicit args, we must not do semantic
13628 processing during substitution as we could create partial
13630 for (i = 0; i < len; i++)
13632 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
13633 bool parameter_pack = false;
13635 /* Dig out the actual parm. */
13636 if (TREE_CODE (parm) == TYPE_DECL
13637 || TREE_CODE (parm) == TEMPLATE_DECL)
13639 parm = TREE_TYPE (parm);
13640 parameter_pack = TEMPLATE_TYPE_PARAMETER_PACK (parm);
13642 else if (TREE_CODE (parm) == PARM_DECL)
13644 parm = DECL_INITIAL (parm);
13645 parameter_pack = TEMPLATE_PARM_PARAMETER_PACK (parm);
13648 if (parameter_pack)
13652 template_parm_level_and_index (parm, &level, &idx);
13654 /* Mark the argument pack as "incomplete". We could
13655 still deduce more arguments during unification. */
13656 targ = TMPL_ARG (converted_args, level, idx);
13659 ARGUMENT_PACK_INCOMPLETE_P(targ) = 1;
13660 ARGUMENT_PACK_EXPLICIT_ARGS (targ)
13661 = ARGUMENT_PACK_ARGS (targ);
13664 /* We have some incomplete argument packs. */
13665 incomplete_argument_packs_p = true;
13669 if (incomplete_argument_packs_p)
13670 /* Any substitution is guaranteed to be incomplete if there
13671 are incomplete argument packs, because we can still deduce
13675 incomplete = NUM_TMPL_ARGS (explicit_targs) != NUM_TMPL_ARGS (targs);
13677 processing_template_decl += incomplete;
13678 fntype = tsubst (fntype, converted_args, tf_none, NULL_TREE);
13679 processing_template_decl -= incomplete;
13681 if (fntype == error_mark_node)
13684 /* Place the explicitly specified arguments in TARGS. */
13685 for (i = NUM_TMPL_ARGS (converted_args); i--;)
13686 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (converted_args, i);
13689 /* Never do unification on the 'this' parameter. */
13690 parms = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (fntype));
13696 parms = tree_cons (NULL_TREE, TREE_TYPE (fntype), parms);
13697 new_args = XALLOCAVEC (tree, nargs + 1);
13698 new_args[0] = return_type;
13699 memcpy (new_args + 1, args, nargs * sizeof (tree));
13704 /* We allow incomplete unification without an error message here
13705 because the standard doesn't seem to explicitly prohibit it. Our
13706 callers must be ready to deal with unification failures in any
13708 result = type_unification_real (DECL_INNERMOST_TEMPLATE_PARMS (fn),
13709 targs, parms, args, nargs, /*subr=*/0,
13712 if (result == 0 && incomplete_argument_packs_p)
13714 int i, len = NUM_TMPL_ARGS (targs);
13716 /* Clear the "incomplete" flags on all argument packs. */
13717 for (i = 0; i < len; i++)
13719 tree arg = TREE_VEC_ELT (targs, i);
13720 if (ARGUMENT_PACK_P (arg))
13722 ARGUMENT_PACK_INCOMPLETE_P (arg) = 0;
13723 ARGUMENT_PACK_EXPLICIT_ARGS (arg) = NULL_TREE;
13728 /* Now that we have bindings for all of the template arguments,
13729 ensure that the arguments deduced for the template template
13730 parameters have compatible template parameter lists. We cannot
13731 check this property before we have deduced all template
13732 arguments, because the template parameter types of a template
13733 template parameter might depend on prior template parameters
13734 deduced after the template template parameter. The following
13735 ill-formed example illustrates this issue:
13737 template<typename T, template<T> class C> void f(C<5>, T);
13739 template<int N> struct X {};
13742 f(X<5>(), 5l); // error: template argument deduction fails
13745 The template parameter list of 'C' depends on the template type
13746 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
13747 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
13748 time that we deduce 'C'. */
13750 && !template_template_parm_bindings_ok_p
13751 (DECL_INNERMOST_TEMPLATE_PARMS (fn), targs))
13755 /* All is well so far. Now, check:
13759 When all template arguments have been deduced, all uses of
13760 template parameters in nondeduced contexts are replaced with
13761 the corresponding deduced argument values. If the
13762 substitution results in an invalid type, as described above,
13763 type deduction fails. */
13765 tree substed = tsubst (TREE_TYPE (fn), targs, tf_none, NULL_TREE);
13766 if (substed == error_mark_node)
13769 /* If we're looking for an exact match, check that what we got
13770 is indeed an exact match. It might not be if some template
13771 parameters are used in non-deduced contexts. */
13772 if (strict == DEDUCE_EXACT)
13777 = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (substed));
13779 sarg = tree_cons (NULL_TREE, TREE_TYPE (substed), sarg);
13780 for (i = 0; i < nargs && sarg; ++i, sarg = TREE_CHAIN (sarg))
13781 if (!same_type_p (args[i], TREE_VALUE (sarg)))
13789 /* Adjust types before performing type deduction, as described in
13790 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
13791 sections are symmetric. PARM is the type of a function parameter
13792 or the return type of the conversion function. ARG is the type of
13793 the argument passed to the call, or the type of the value
13794 initialized with the result of the conversion function.
13795 ARG_EXPR is the original argument expression, which may be null. */
13798 maybe_adjust_types_for_deduction (unification_kind_t strict,
13812 /* Swap PARM and ARG throughout the remainder of this
13813 function; the handling is precisely symmetric since PARM
13814 will initialize ARG rather than vice versa. */
13822 /* Core issue #873: Do the DR606 thing (see below) for these cases,
13823 too, but here handle it by stripping the reference from PARM
13824 rather than by adding it to ARG. */
13825 if (TREE_CODE (*parm) == REFERENCE_TYPE
13826 && TYPE_REF_IS_RVALUE (*parm)
13827 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
13828 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
13829 && TREE_CODE (*arg) == REFERENCE_TYPE
13830 && !TYPE_REF_IS_RVALUE (*arg))
13831 *parm = TREE_TYPE (*parm);
13832 /* Nothing else to do in this case. */
13836 gcc_unreachable ();
13839 if (TREE_CODE (*parm) != REFERENCE_TYPE)
13841 /* [temp.deduct.call]
13843 If P is not a reference type:
13845 --If A is an array type, the pointer type produced by the
13846 array-to-pointer standard conversion (_conv.array_) is
13847 used in place of A for type deduction; otherwise,
13849 --If A is a function type, the pointer type produced by
13850 the function-to-pointer standard conversion
13851 (_conv.func_) is used in place of A for type deduction;
13854 --If A is a cv-qualified type, the top level
13855 cv-qualifiers of A's type are ignored for type
13857 if (TREE_CODE (*arg) == ARRAY_TYPE)
13858 *arg = build_pointer_type (TREE_TYPE (*arg));
13859 else if (TREE_CODE (*arg) == FUNCTION_TYPE)
13860 *arg = build_pointer_type (*arg);
13862 *arg = TYPE_MAIN_VARIANT (*arg);
13865 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
13866 of the form T&&, where T is a template parameter, and the argument
13867 is an lvalue, T is deduced as A& */
13868 if (TREE_CODE (*parm) == REFERENCE_TYPE
13869 && TYPE_REF_IS_RVALUE (*parm)
13870 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
13871 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
13872 && arg_expr && real_lvalue_p (arg_expr))
13873 *arg = build_reference_type (*arg);
13875 /* [temp.deduct.call]
13877 If P is a cv-qualified type, the top level cv-qualifiers
13878 of P's type are ignored for type deduction. If P is a
13879 reference type, the type referred to by P is used for
13881 *parm = TYPE_MAIN_VARIANT (*parm);
13882 if (TREE_CODE (*parm) == REFERENCE_TYPE)
13884 *parm = TREE_TYPE (*parm);
13885 result |= UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
13888 /* DR 322. For conversion deduction, remove a reference type on parm
13889 too (which has been swapped into ARG). */
13890 if (strict == DEDUCE_CONV && TREE_CODE (*arg) == REFERENCE_TYPE)
13891 *arg = TREE_TYPE (*arg);
13896 /* Most parms like fn_type_unification.
13898 If SUBR is 1, we're being called recursively (to unify the
13899 arguments of a function or method parameter of a function
13903 type_unification_real (tree tparms,
13907 unsigned int xnargs,
13909 unification_kind_t strict,
13912 tree parm, arg, arg_expr;
13914 int ntparms = TREE_VEC_LENGTH (tparms);
13916 int saw_undeduced = 0;
13919 unsigned int nargs;
13922 gcc_assert (TREE_CODE (tparms) == TREE_VEC);
13923 gcc_assert (xparms == NULL_TREE || TREE_CODE (xparms) == TREE_LIST);
13924 gcc_assert (ntparms > 0);
13926 /* Reset the number of non-defaulted template arguments contained
13928 NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs) = NULL_TREE;
13933 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL | UNIFY_ALLOW_MORE_CV_QUAL
13934 | UNIFY_ALLOW_DERIVED);
13938 sub_strict = UNIFY_ALLOW_LESS_CV_QUAL;
13942 sub_strict = UNIFY_ALLOW_NONE;
13946 gcc_unreachable ();
13955 while (parms && parms != void_list_node
13958 if (TREE_CODE (TREE_VALUE (parms)) == TYPE_PACK_EXPANSION)
13961 parm = TREE_VALUE (parms);
13962 parms = TREE_CHAIN (parms);
13967 if (arg == error_mark_node)
13969 if (arg == unknown_type_node)
13970 /* We can't deduce anything from this, but we might get all the
13971 template args from other function args. */
13974 /* Conversions will be performed on a function argument that
13975 corresponds with a function parameter that contains only
13976 non-deducible template parameters and explicitly specified
13977 template parameters. */
13978 if (!uses_template_parms (parm))
13983 type = TREE_TYPE (arg);
13987 if (same_type_p (parm, type))
13989 if (strict != DEDUCE_EXACT
13990 && can_convert_arg (parm, type, TYPE_P (arg) ? NULL_TREE : arg,
13999 gcc_assert (TREE_TYPE (arg) != NULL_TREE);
14000 if (type_unknown_p (arg))
14002 /* [temp.deduct.type]
14004 A template-argument can be deduced from a pointer to
14005 function or pointer to member function argument if
14006 the set of overloaded functions does not contain
14007 function templates and at most one of a set of
14008 overloaded functions provides a unique match. */
14009 if (resolve_overloaded_unification
14010 (tparms, targs, parm, arg, strict, sub_strict))
14016 arg = unlowered_expr_type (arg);
14017 if (arg == error_mark_node)
14022 int arg_strict = sub_strict;
14025 arg_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg,
14028 if (arg == init_list_type_node && arg_expr)
14030 if (unify (tparms, targs, parm, arg, arg_strict))
14037 && parms != void_list_node
14038 && TREE_CODE (TREE_VALUE (parms)) == TYPE_PACK_EXPANSION)
14040 /* Unify the remaining arguments with the pack expansion type. */
14042 tree parmvec = make_tree_vec (1);
14044 /* Allocate a TREE_VEC and copy in all of the arguments */
14045 argvec = make_tree_vec (nargs - ia);
14046 for (i = 0; ia < nargs; ++ia, ++i)
14047 TREE_VEC_ELT (argvec, i) = args[ia];
14049 /* Copy the parameter into parmvec. */
14050 TREE_VEC_ELT (parmvec, 0) = TREE_VALUE (parms);
14051 if (unify_pack_expansion (tparms, targs, parmvec, argvec, strict,
14052 /*call_args_p=*/true, /*subr=*/subr))
14055 /* Advance to the end of the list of parameters. */
14056 parms = TREE_CHAIN (parms);
14059 /* Fail if we've reached the end of the parm list, and more args
14060 are present, and the parm list isn't variadic. */
14061 if (ia < nargs && parms == void_list_node)
14063 /* Fail if parms are left and they don't have default values. */
14064 if (parms && parms != void_list_node
14065 && TREE_PURPOSE (parms) == NULL_TREE)
14069 for (i = 0; i < ntparms; i++)
14070 if (!TREE_VEC_ELT (targs, i))
14074 if (TREE_VEC_ELT (tparms, i) == error_mark_node)
14077 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
14079 /* If this is an undeduced nontype parameter that depends on
14080 a type parameter, try another pass; its type may have been
14081 deduced from a later argument than the one from which
14082 this parameter can be deduced. */
14083 if (TREE_CODE (tparm) == PARM_DECL
14084 && uses_template_parms (TREE_TYPE (tparm))
14085 && !saw_undeduced++)
14088 /* Core issue #226 (C++0x) [temp.deduct]:
14090 If a template argument has not been deduced, its
14091 default template argument, if any, is used.
14093 When we are in C++98 mode, TREE_PURPOSE will either
14094 be NULL_TREE or ERROR_MARK_NODE, so we do not need
14095 to explicitly check cxx_dialect here. */
14096 if (TREE_PURPOSE (TREE_VEC_ELT (tparms, i)))
14098 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
14099 tree arg = TREE_PURPOSE (TREE_VEC_ELT (tparms, i));
14100 arg = tsubst_template_arg (arg, targs, tf_none, NULL_TREE);
14101 arg = convert_template_argument (parm, arg, targs, tf_none,
14103 if (arg == error_mark_node)
14107 TREE_VEC_ELT (targs, i) = arg;
14108 /* The position of the first default template argument,
14109 is also the number of non-defaulted arguments in TARGS.
14111 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs))
14112 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, i);
14117 /* If the type parameter is a parameter pack, then it will
14118 be deduced to an empty parameter pack. */
14119 if (template_parameter_pack_p (tparm))
14123 if (TREE_CODE (tparm) == TEMPLATE_PARM_INDEX)
14125 arg = make_node (NONTYPE_ARGUMENT_PACK);
14126 TREE_TYPE (arg) = TREE_TYPE (TEMPLATE_PARM_DECL (tparm));
14127 TREE_CONSTANT (arg) = 1;
14130 arg = cxx_make_type (TYPE_ARGUMENT_PACK);
14132 SET_ARGUMENT_PACK_ARGS (arg, make_tree_vec (0));
14134 TREE_VEC_ELT (targs, i) = arg;
14140 #ifdef ENABLE_CHECKING
14141 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs))
14142 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, TREE_VEC_LENGTH (targs));
14148 /* Subroutine of type_unification_real. Args are like the variables
14149 at the call site. ARG is an overloaded function (or template-id);
14150 we try deducing template args from each of the overloads, and if
14151 only one succeeds, we go with that. Modifies TARGS and returns
14152 true on success. */
14155 resolve_overloaded_unification (tree tparms,
14159 unification_kind_t strict,
14162 tree tempargs = copy_node (targs);
14164 tree goodfn = NULL_TREE;
14167 if (TREE_CODE (arg) == ADDR_EXPR)
14169 arg = TREE_OPERAND (arg, 0);
14175 if (TREE_CODE (arg) == COMPONENT_REF)
14176 /* Handle `&x' where `x' is some static or non-static member
14178 arg = TREE_OPERAND (arg, 1);
14180 if (TREE_CODE (arg) == OFFSET_REF)
14181 arg = TREE_OPERAND (arg, 1);
14183 /* Strip baselink information. */
14184 if (BASELINK_P (arg))
14185 arg = BASELINK_FUNCTIONS (arg);
14187 if (TREE_CODE (arg) == TEMPLATE_ID_EXPR)
14189 /* If we got some explicit template args, we need to plug them into
14190 the affected templates before we try to unify, in case the
14191 explicit args will completely resolve the templates in question. */
14193 tree expl_subargs = TREE_OPERAND (arg, 1);
14194 arg = TREE_OPERAND (arg, 0);
14196 for (; arg; arg = OVL_NEXT (arg))
14198 tree fn = OVL_CURRENT (arg);
14199 tree subargs, elem;
14201 if (TREE_CODE (fn) != TEMPLATE_DECL)
14204 ++processing_template_decl;
14205 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
14206 expl_subargs, /*check_ret=*/false);
14209 elem = tsubst (TREE_TYPE (fn), subargs, tf_none, NULL_TREE);
14210 if (try_one_overload (tparms, targs, tempargs, parm,
14211 elem, strict, sub_strict, addr_p)
14212 && (!goodfn || !decls_match (goodfn, elem)))
14218 --processing_template_decl;
14221 else if (TREE_CODE (arg) != OVERLOAD
14222 && TREE_CODE (arg) != FUNCTION_DECL)
14223 /* If ARG is, for example, "(0, &f)" then its type will be unknown
14224 -- but the deduction does not succeed because the expression is
14225 not just the function on its own. */
14228 for (; arg; arg = OVL_NEXT (arg))
14229 if (try_one_overload (tparms, targs, tempargs, parm,
14230 TREE_TYPE (OVL_CURRENT (arg)),
14231 strict, sub_strict, addr_p)
14232 && (!goodfn || !decls_match (goodfn, OVL_CURRENT (arg))))
14234 goodfn = OVL_CURRENT (arg);
14238 /* [temp.deduct.type] A template-argument can be deduced from a pointer
14239 to function or pointer to member function argument if the set of
14240 overloaded functions does not contain function templates and at most
14241 one of a set of overloaded functions provides a unique match.
14243 So if we found multiple possibilities, we return success but don't
14244 deduce anything. */
14248 int i = TREE_VEC_LENGTH (targs);
14250 if (TREE_VEC_ELT (tempargs, i))
14251 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (tempargs, i);
14259 /* Core DR 115: In contexts where deduction is done and fails, or in
14260 contexts where deduction is not done, if a template argument list is
14261 specified and it, along with any default template arguments, identifies
14262 a single function template specialization, then the template-id is an
14263 lvalue for the function template specialization. */
14266 resolve_nondeduced_context (tree orig_expr)
14268 tree expr, offset, baselink;
14271 if (!type_unknown_p (orig_expr))
14276 offset = NULL_TREE;
14277 baselink = NULL_TREE;
14279 if (TREE_CODE (expr) == ADDR_EXPR)
14281 expr = TREE_OPERAND (expr, 0);
14284 if (TREE_CODE (expr) == OFFSET_REF)
14287 expr = TREE_OPERAND (expr, 1);
14289 if (TREE_CODE (expr) == BASELINK)
14292 expr = BASELINK_FUNCTIONS (expr);
14295 if (TREE_CODE (expr) == TEMPLATE_ID_EXPR)
14298 tree goodfn = NULL_TREE;
14300 /* If we got some explicit template args, we need to plug them into
14301 the affected templates before we try to unify, in case the
14302 explicit args will completely resolve the templates in question. */
14304 tree expl_subargs = TREE_OPERAND (expr, 1);
14305 tree arg = TREE_OPERAND (expr, 0);
14306 tree badfn = NULL_TREE;
14307 tree badargs = NULL_TREE;
14309 for (; arg; arg = OVL_NEXT (arg))
14311 tree fn = OVL_CURRENT (arg);
14312 tree subargs, elem;
14314 if (TREE_CODE (fn) != TEMPLATE_DECL)
14317 ++processing_template_decl;
14318 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
14319 expl_subargs, /*check_ret=*/false);
14320 if (subargs && !any_dependent_template_arguments_p (subargs))
14322 elem = instantiate_template (fn, subargs, tf_none);
14323 if (elem == error_mark_node)
14328 else if (elem && (!goodfn || !decls_match (goodfn, elem)))
14334 --processing_template_decl;
14340 expr = build_baselink (BASELINK_BINFO (baselink),
14341 BASELINK_ACCESS_BINFO (baselink),
14342 expr, BASELINK_OPTYPE (baselink));
14346 = TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (offset, 0)));
14347 expr = build_offset_ref (base, expr, addr);
14350 expr = cp_build_addr_expr (expr, tf_warning_or_error);
14353 else if (good == 0 && badargs)
14354 /* There were no good options and at least one bad one, so let the
14355 user know what the problem is. */
14356 instantiate_template (badfn, badargs, tf_warning_or_error);
14361 /* Subroutine of resolve_overloaded_unification; does deduction for a single
14362 overload. Fills TARGS with any deduced arguments, or error_mark_node if
14363 different overloads deduce different arguments for a given parm.
14364 ADDR_P is true if the expression for which deduction is being
14365 performed was of the form "& fn" rather than simply "fn".
14367 Returns 1 on success. */
14370 try_one_overload (tree tparms,
14375 unification_kind_t strict,
14383 /* [temp.deduct.type] A template-argument can be deduced from a pointer
14384 to function or pointer to member function argument if the set of
14385 overloaded functions does not contain function templates and at most
14386 one of a set of overloaded functions provides a unique match.
14388 So if this is a template, just return success. */
14390 if (uses_template_parms (arg))
14393 if (TREE_CODE (arg) == METHOD_TYPE)
14394 arg = build_ptrmemfunc_type (build_pointer_type (arg));
14396 arg = build_pointer_type (arg);
14398 sub_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg, NULL);
14400 /* We don't copy orig_targs for this because if we have already deduced
14401 some template args from previous args, unify would complain when we
14402 try to deduce a template parameter for the same argument, even though
14403 there isn't really a conflict. */
14404 nargs = TREE_VEC_LENGTH (targs);
14405 tempargs = make_tree_vec (nargs);
14407 if (unify (tparms, tempargs, parm, arg, sub_strict) != 0)
14410 /* First make sure we didn't deduce anything that conflicts with
14411 explicitly specified args. */
14412 for (i = nargs; i--; )
14414 tree elt = TREE_VEC_ELT (tempargs, i);
14415 tree oldelt = TREE_VEC_ELT (orig_targs, i);
14419 else if (uses_template_parms (elt))
14420 /* Since we're unifying against ourselves, we will fill in
14421 template args used in the function parm list with our own
14422 template parms. Discard them. */
14423 TREE_VEC_ELT (tempargs, i) = NULL_TREE;
14424 else if (oldelt && !template_args_equal (oldelt, elt))
14428 for (i = nargs; i--; )
14430 tree elt = TREE_VEC_ELT (tempargs, i);
14433 TREE_VEC_ELT (targs, i) = elt;
14439 /* PARM is a template class (perhaps with unbound template
14440 parameters). ARG is a fully instantiated type. If ARG can be
14441 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
14442 TARGS are as for unify. */
14445 try_class_unification (tree tparms, tree targs, tree parm, tree arg)
14447 tree copy_of_targs;
14449 if (!CLASSTYPE_TEMPLATE_INFO (arg)
14450 || (most_general_template (CLASSTYPE_TI_TEMPLATE (arg))
14451 != most_general_template (CLASSTYPE_TI_TEMPLATE (parm))))
14454 /* We need to make a new template argument vector for the call to
14455 unify. If we used TARGS, we'd clutter it up with the result of
14456 the attempted unification, even if this class didn't work out.
14457 We also don't want to commit ourselves to all the unifications
14458 we've already done, since unification is supposed to be done on
14459 an argument-by-argument basis. In other words, consider the
14460 following pathological case:
14462 template <int I, int J, int K>
14465 template <int I, int J>
14466 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
14468 template <int I, int J, int K>
14469 void f(S<I, J, K>, S<I, I, I>);
14478 Now, by the time we consider the unification involving `s2', we
14479 already know that we must have `f<0, 0, 0>'. But, even though
14480 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
14481 because there are two ways to unify base classes of S<0, 1, 2>
14482 with S<I, I, I>. If we kept the already deduced knowledge, we
14483 would reject the possibility I=1. */
14484 copy_of_targs = make_tree_vec (TREE_VEC_LENGTH (targs));
14486 /* If unification failed, we're done. */
14487 if (unify (tparms, copy_of_targs, CLASSTYPE_TI_ARGS (parm),
14488 CLASSTYPE_TI_ARGS (arg), UNIFY_ALLOW_NONE))
14494 /* Given a template type PARM and a class type ARG, find the unique
14495 base type in ARG that is an instance of PARM. We do not examine
14496 ARG itself; only its base-classes. If there is not exactly one
14497 appropriate base class, return NULL_TREE. PARM may be the type of
14498 a partial specialization, as well as a plain template type. Used
14502 get_template_base (tree tparms, tree targs, tree parm, tree arg)
14504 tree rval = NULL_TREE;
14507 gcc_assert (RECORD_OR_UNION_CODE_P (TREE_CODE (arg)));
14509 binfo = TYPE_BINFO (complete_type (arg));
14511 /* The type could not be completed. */
14514 /* Walk in inheritance graph order. The search order is not
14515 important, and this avoids multiple walks of virtual bases. */
14516 for (binfo = TREE_CHAIN (binfo); binfo; binfo = TREE_CHAIN (binfo))
14518 tree r = try_class_unification (tparms, targs, parm, BINFO_TYPE (binfo));
14522 /* If there is more than one satisfactory baseclass, then:
14526 If they yield more than one possible deduced A, the type
14530 if (rval && !same_type_p (r, rval))
14540 /* Returns the level of DECL, which declares a template parameter. */
14543 template_decl_level (tree decl)
14545 switch (TREE_CODE (decl))
14548 case TEMPLATE_DECL:
14549 return TEMPLATE_TYPE_LEVEL (TREE_TYPE (decl));
14552 return TEMPLATE_PARM_LEVEL (DECL_INITIAL (decl));
14555 gcc_unreachable ();
14560 /* Decide whether ARG can be unified with PARM, considering only the
14561 cv-qualifiers of each type, given STRICT as documented for unify.
14562 Returns nonzero iff the unification is OK on that basis. */
14565 check_cv_quals_for_unify (int strict, tree arg, tree parm)
14567 int arg_quals = cp_type_quals (arg);
14568 int parm_quals = cp_type_quals (parm);
14570 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
14571 && !(strict & UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
14573 /* Although a CVR qualifier is ignored when being applied to a
14574 substituted template parameter ([8.3.2]/1 for example), that
14575 does not allow us to unify "const T" with "int&" because both
14576 types are not of the form "cv-list T" [14.8.2.5 temp.deduct.type].
14577 It is ok when we're allowing additional CV qualifiers
14578 at the outer level [14.8.2.1]/3,1st bullet. */
14579 if ((TREE_CODE (arg) == REFERENCE_TYPE
14580 || TREE_CODE (arg) == FUNCTION_TYPE
14581 || TREE_CODE (arg) == METHOD_TYPE)
14582 && (parm_quals & (TYPE_QUAL_CONST | TYPE_QUAL_VOLATILE)))
14585 if ((!POINTER_TYPE_P (arg) && TREE_CODE (arg) != TEMPLATE_TYPE_PARM)
14586 && (parm_quals & TYPE_QUAL_RESTRICT))
14590 if (!(strict & (UNIFY_ALLOW_MORE_CV_QUAL | UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
14591 && (arg_quals & parm_quals) != parm_quals)
14594 if (!(strict & (UNIFY_ALLOW_LESS_CV_QUAL | UNIFY_ALLOW_OUTER_LESS_CV_QUAL))
14595 && (parm_quals & arg_quals) != arg_quals)
14601 /* Determines the LEVEL and INDEX for the template parameter PARM. */
14603 template_parm_level_and_index (tree parm, int* level, int* index)
14605 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
14606 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
14607 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
14609 *index = TEMPLATE_TYPE_IDX (parm);
14610 *level = TEMPLATE_TYPE_LEVEL (parm);
14614 *index = TEMPLATE_PARM_IDX (parm);
14615 *level = TEMPLATE_PARM_LEVEL (parm);
14619 /* Unifies the remaining arguments in PACKED_ARGS with the pack
14620 expansion at the end of PACKED_PARMS. Returns 0 if the type
14621 deduction succeeds, 1 otherwise. STRICT is the same as in
14622 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
14623 call argument list. We'll need to adjust the arguments to make them
14624 types. SUBR tells us if this is from a recursive call to
14625 type_unification_real. */
14627 unify_pack_expansion (tree tparms, tree targs, tree packed_parms,
14628 tree packed_args, int strict, bool call_args_p,
14632 = TREE_VEC_ELT (packed_parms, TREE_VEC_LENGTH (packed_parms) - 1);
14633 tree pattern = PACK_EXPANSION_PATTERN (parm);
14634 tree pack, packs = NULL_TREE;
14635 int i, start = TREE_VEC_LENGTH (packed_parms) - 1;
14636 int len = TREE_VEC_LENGTH (packed_args);
14638 /* Determine the parameter packs we will be deducing from the
14639 pattern, and record their current deductions. */
14640 for (pack = PACK_EXPANSION_PARAMETER_PACKS (parm);
14641 pack; pack = TREE_CHAIN (pack))
14643 tree parm_pack = TREE_VALUE (pack);
14646 /* Determine the index and level of this parameter pack. */
14647 template_parm_level_and_index (parm_pack, &level, &idx);
14649 /* Keep track of the parameter packs and their corresponding
14651 packs = tree_cons (parm_pack, TMPL_ARG (targs, level, idx), packs);
14652 TREE_TYPE (packs) = make_tree_vec (len - start);
14655 /* Loop through all of the arguments that have not yet been
14656 unified and unify each with the pattern. */
14657 for (i = start; i < len; i++)
14659 tree parm = pattern;
14661 /* For each parameter pack, clear out the deduced value so that
14662 we can deduce it again. */
14663 for (pack = packs; pack; pack = TREE_CHAIN (pack))
14666 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
14668 TMPL_ARG (targs, level, idx) = NULL_TREE;
14671 /* Unify the pattern with the current argument. */
14673 tree arg = TREE_VEC_ELT (packed_args, i);
14674 tree arg_expr = NULL_TREE;
14675 int arg_strict = strict;
14676 bool skip_arg_p = false;
14682 /* This mirrors what we do in type_unification_real. */
14686 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL
14687 | UNIFY_ALLOW_MORE_CV_QUAL
14688 | UNIFY_ALLOW_DERIVED);
14692 sub_strict = UNIFY_ALLOW_LESS_CV_QUAL;
14696 sub_strict = UNIFY_ALLOW_NONE;
14700 gcc_unreachable ();
14705 gcc_assert (TREE_TYPE (arg) != NULL_TREE);
14706 if (type_unknown_p (arg))
14708 /* [temp.deduct.type] A template-argument can be
14709 deduced from a pointer to function or pointer
14710 to member function argument if the set of
14711 overloaded functions does not contain function
14712 templates and at most one of a set of
14713 overloaded functions provides a unique
14716 if (resolve_overloaded_unification
14717 (tparms, targs, parm, arg,
14718 (unification_kind_t) strict,
14728 arg = unlowered_expr_type (arg);
14729 if (arg == error_mark_node)
14734 arg_strict = sub_strict;
14738 maybe_adjust_types_for_deduction ((unification_kind_t) strict,
14739 &parm, &arg, arg_expr);
14744 /* For deduction from an init-list we need the actual list. */
14745 if (arg_expr && BRACE_ENCLOSED_INITIALIZER_P (arg_expr))
14747 if (unify (tparms, targs, parm, arg, arg_strict))
14752 /* For each parameter pack, collect the deduced value. */
14753 for (pack = packs; pack; pack = TREE_CHAIN (pack))
14756 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
14758 TREE_VEC_ELT (TREE_TYPE (pack), i - start) =
14759 TMPL_ARG (targs, level, idx);
14763 /* Verify that the results of unification with the parameter packs
14764 produce results consistent with what we've seen before, and make
14765 the deduced argument packs available. */
14766 for (pack = packs; pack; pack = TREE_CHAIN (pack))
14768 tree old_pack = TREE_VALUE (pack);
14769 tree new_args = TREE_TYPE (pack);
14770 int i, len = TREE_VEC_LENGTH (new_args);
14772 bool nondeduced_p = false;
14774 /* By default keep the original deduced argument pack.
14775 If necessary, more specific code is going to update the
14776 resulting deduced argument later down in this function. */
14777 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
14778 TMPL_ARG (targs, level, idx) = old_pack;
14780 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
14781 actually deduce anything. */
14782 for (i = 0; i < len && !nondeduced_p; ++i)
14783 if (TREE_VEC_ELT (new_args, i) == NULL_TREE)
14784 nondeduced_p = true;
14788 if (old_pack && ARGUMENT_PACK_INCOMPLETE_P (old_pack))
14790 /* Prepend the explicit arguments onto NEW_ARGS. */
14791 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
14792 tree old_args = new_args;
14793 int i, explicit_len = TREE_VEC_LENGTH (explicit_args);
14794 int len = explicit_len + TREE_VEC_LENGTH (old_args);
14796 /* Copy the explicit arguments. */
14797 new_args = make_tree_vec (len);
14798 for (i = 0; i < explicit_len; i++)
14799 TREE_VEC_ELT (new_args, i) = TREE_VEC_ELT (explicit_args, i);
14801 /* Copy the deduced arguments. */
14802 for (; i < len; i++)
14803 TREE_VEC_ELT (new_args, i) =
14804 TREE_VEC_ELT (old_args, i - explicit_len);
14810 /* Build the deduced *_ARGUMENT_PACK. */
14811 if (TREE_CODE (TREE_PURPOSE (pack)) == TEMPLATE_PARM_INDEX)
14813 result = make_node (NONTYPE_ARGUMENT_PACK);
14814 TREE_TYPE (result) =
14815 TREE_TYPE (TEMPLATE_PARM_DECL (TREE_PURPOSE (pack)));
14816 TREE_CONSTANT (result) = 1;
14819 result = cxx_make_type (TYPE_ARGUMENT_PACK);
14821 SET_ARGUMENT_PACK_ARGS (result, new_args);
14823 /* Note the deduced argument packs for this parameter
14825 TMPL_ARG (targs, level, idx) = result;
14827 else if (ARGUMENT_PACK_INCOMPLETE_P (old_pack)
14828 && (ARGUMENT_PACK_ARGS (old_pack)
14829 == ARGUMENT_PACK_EXPLICIT_ARGS (old_pack)))
14831 /* We only had the explicitly-provided arguments before, but
14832 now we have a complete set of arguments. */
14833 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
14835 SET_ARGUMENT_PACK_ARGS (old_pack, new_args);
14836 ARGUMENT_PACK_INCOMPLETE_P (old_pack) = 1;
14837 ARGUMENT_PACK_EXPLICIT_ARGS (old_pack) = explicit_args;
14839 else if (!comp_template_args (ARGUMENT_PACK_ARGS (old_pack),
14841 /* Inconsistent unification of this parameter pack. */
14848 /* Deduce the value of template parameters. TPARMS is the (innermost)
14849 set of template parameters to a template. TARGS is the bindings
14850 for those template parameters, as determined thus far; TARGS may
14851 include template arguments for outer levels of template parameters
14852 as well. PARM is a parameter to a template function, or a
14853 subcomponent of that parameter; ARG is the corresponding argument.
14854 This function attempts to match PARM with ARG in a manner
14855 consistent with the existing assignments in TARGS. If more values
14856 are deduced, then TARGS is updated.
14858 Returns 0 if the type deduction succeeds, 1 otherwise. The
14859 parameter STRICT is a bitwise or of the following flags:
14862 Require an exact match between PARM and ARG.
14863 UNIFY_ALLOW_MORE_CV_QUAL:
14864 Allow the deduced ARG to be more cv-qualified (by qualification
14865 conversion) than ARG.
14866 UNIFY_ALLOW_LESS_CV_QUAL:
14867 Allow the deduced ARG to be less cv-qualified than ARG.
14868 UNIFY_ALLOW_DERIVED:
14869 Allow the deduced ARG to be a template base class of ARG,
14870 or a pointer to a template base class of the type pointed to by
14872 UNIFY_ALLOW_INTEGER:
14873 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
14874 case for more information.
14875 UNIFY_ALLOW_OUTER_LEVEL:
14876 This is the outermost level of a deduction. Used to determine validity
14877 of qualification conversions. A valid qualification conversion must
14878 have const qualified pointers leading up to the inner type which
14879 requires additional CV quals, except at the outer level, where const
14880 is not required [conv.qual]. It would be normal to set this flag in
14881 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
14882 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
14883 This is the outermost level of a deduction, and PARM can be more CV
14884 qualified at this point.
14885 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
14886 This is the outermost level of a deduction, and PARM can be less CV
14887 qualified at this point. */
14890 unify (tree tparms, tree targs, tree parm, tree arg, int strict)
14895 int strict_in = strict;
14897 /* I don't think this will do the right thing with respect to types.
14898 But the only case I've seen it in so far has been array bounds, where
14899 signedness is the only information lost, and I think that will be
14901 while (TREE_CODE (parm) == NOP_EXPR)
14902 parm = TREE_OPERAND (parm, 0);
14904 if (arg == error_mark_node)
14906 if (arg == unknown_type_node
14907 || arg == init_list_type_node)
14908 /* We can't deduce anything from this, but we might get all the
14909 template args from other function args. */
14912 /* If PARM uses template parameters, then we can't bail out here,
14913 even if ARG == PARM, since we won't record unifications for the
14914 template parameters. We might need them if we're trying to
14915 figure out which of two things is more specialized. */
14916 if (arg == parm && !uses_template_parms (parm))
14919 /* Handle init lists early, so the rest of the function can assume
14920 we're dealing with a type. */
14921 if (BRACE_ENCLOSED_INITIALIZER_P (arg))
14925 tree orig_parm = parm;
14927 /* Replace T with std::initializer_list<T> for deduction. */
14928 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
14929 && flag_deduce_init_list)
14930 parm = listify (parm);
14932 if (!is_std_init_list (parm))
14933 /* We can only deduce from an initializer list argument if the
14934 parameter is std::initializer_list; otherwise this is a
14935 non-deduced context. */
14938 elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (parm), 0);
14940 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg), i, elt)
14942 int elt_strict = strict;
14944 if (elt == error_mark_node)
14947 if (!BRACE_ENCLOSED_INITIALIZER_P (elt))
14949 tree type = TREE_TYPE (elt);
14950 /* It should only be possible to get here for a call. */
14951 gcc_assert (elt_strict & UNIFY_ALLOW_OUTER_LEVEL);
14952 elt_strict |= maybe_adjust_types_for_deduction
14953 (DEDUCE_CALL, &elttype, &type, elt);
14957 if (unify (tparms, targs, elttype, elt, elt_strict))
14961 /* If the std::initializer_list<T> deduction worked, replace the
14962 deduced A with std::initializer_list<A>. */
14963 if (orig_parm != parm)
14965 idx = TEMPLATE_TYPE_IDX (orig_parm);
14966 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
14967 targ = listify (targ);
14968 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = targ;
14973 /* Immediately reject some pairs that won't unify because of
14974 cv-qualification mismatches. */
14975 if (TREE_CODE (arg) == TREE_CODE (parm)
14977 /* It is the elements of the array which hold the cv quals of an array
14978 type, and the elements might be template type parms. We'll check
14979 when we recurse. */
14980 && TREE_CODE (arg) != ARRAY_TYPE
14981 /* We check the cv-qualifiers when unifying with template type
14982 parameters below. We want to allow ARG `const T' to unify with
14983 PARM `T' for example, when computing which of two templates
14984 is more specialized, for example. */
14985 && TREE_CODE (arg) != TEMPLATE_TYPE_PARM
14986 && !check_cv_quals_for_unify (strict_in, arg, parm))
14989 if (!(strict & UNIFY_ALLOW_OUTER_LEVEL)
14990 && TYPE_P (parm) && !CP_TYPE_CONST_P (parm))
14991 strict &= ~UNIFY_ALLOW_MORE_CV_QUAL;
14992 strict &= ~UNIFY_ALLOW_OUTER_LEVEL;
14993 strict &= ~UNIFY_ALLOW_DERIVED;
14994 strict &= ~UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
14995 strict &= ~UNIFY_ALLOW_OUTER_LESS_CV_QUAL;
14997 switch (TREE_CODE (parm))
14999 case TYPENAME_TYPE:
15001 case UNBOUND_CLASS_TEMPLATE:
15002 /* In a type which contains a nested-name-specifier, template
15003 argument values cannot be deduced for template parameters used
15004 within the nested-name-specifier. */
15007 case TEMPLATE_TYPE_PARM:
15008 case TEMPLATE_TEMPLATE_PARM:
15009 case BOUND_TEMPLATE_TEMPLATE_PARM:
15010 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
15011 if (tparm == error_mark_node)
15014 if (TEMPLATE_TYPE_LEVEL (parm)
15015 != template_decl_level (tparm))
15016 /* The PARM is not one we're trying to unify. Just check
15017 to see if it matches ARG. */
15018 return (TREE_CODE (arg) == TREE_CODE (parm)
15019 && same_type_p (parm, arg)) ? 0 : 1;
15020 idx = TEMPLATE_TYPE_IDX (parm);
15021 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
15022 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, idx));
15024 /* Check for mixed types and values. */
15025 if ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
15026 && TREE_CODE (tparm) != TYPE_DECL)
15027 || (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
15028 && TREE_CODE (tparm) != TEMPLATE_DECL))
15031 if (TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
15033 /* ARG must be constructed from a template class or a template
15034 template parameter. */
15035 if (TREE_CODE (arg) != BOUND_TEMPLATE_TEMPLATE_PARM
15036 && !CLASSTYPE_SPECIALIZATION_OF_PRIMARY_TEMPLATE_P (arg))
15040 tree parmvec = TYPE_TI_ARGS (parm);
15041 tree argvec = INNERMOST_TEMPLATE_ARGS (TYPE_TI_ARGS (arg));
15042 tree full_argvec = add_to_template_args (targs, argvec);
15044 = DECL_INNERMOST_TEMPLATE_PARMS
15045 (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (parm));
15047 int parm_variadic_p = 0;
15049 /* The resolution to DR150 makes clear that default
15050 arguments for an N-argument may not be used to bind T
15051 to a template template parameter with fewer than N
15052 parameters. It is not safe to permit the binding of
15053 default arguments as an extension, as that may change
15054 the meaning of a conforming program. Consider:
15056 struct Dense { static const unsigned int dim = 1; };
15058 template <template <typename> class View,
15060 void operator+(float, View<Block> const&);
15062 template <typename Block,
15063 unsigned int Dim = Block::dim>
15064 struct Lvalue_proxy { operator float() const; };
15068 Lvalue_proxy<Dense> p;
15073 Here, if Lvalue_proxy is permitted to bind to View, then
15074 the global operator+ will be used; if they are not, the
15075 Lvalue_proxy will be converted to float. */
15076 if (coerce_template_parms (parm_parms,
15078 TYPE_TI_TEMPLATE (parm),
15080 /*require_all_args=*/true,
15081 /*use_default_args=*/false)
15082 == error_mark_node)
15085 /* Deduce arguments T, i from TT<T> or TT<i>.
15086 We check each element of PARMVEC and ARGVEC individually
15087 rather than the whole TREE_VEC since they can have
15088 different number of elements. */
15090 parmvec = expand_template_argument_pack (parmvec);
15091 argvec = expand_template_argument_pack (argvec);
15093 len = TREE_VEC_LENGTH (parmvec);
15095 /* Check if the parameters end in a pack, making them
15098 && PACK_EXPANSION_P (TREE_VEC_ELT (parmvec, len - 1)))
15099 parm_variadic_p = 1;
15101 if (TREE_VEC_LENGTH (argvec) < len - parm_variadic_p)
15104 for (i = 0; i < len - parm_variadic_p; ++i)
15106 if (unify (tparms, targs,
15107 TREE_VEC_ELT (parmvec, i),
15108 TREE_VEC_ELT (argvec, i),
15113 if (parm_variadic_p
15114 && unify_pack_expansion (tparms, targs,
15117 /*call_args_p=*/false,
15121 arg = TYPE_TI_TEMPLATE (arg);
15123 /* Fall through to deduce template name. */
15126 if (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
15127 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
15129 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
15131 /* Simple cases: Value already set, does match or doesn't. */
15132 if (targ != NULL_TREE && template_args_equal (targ, arg))
15139 /* If PARM is `const T' and ARG is only `int', we don't have
15140 a match unless we are allowing additional qualification.
15141 If ARG is `const int' and PARM is just `T' that's OK;
15142 that binds `const int' to `T'. */
15143 if (!check_cv_quals_for_unify (strict_in | UNIFY_ALLOW_LESS_CV_QUAL,
15147 /* Consider the case where ARG is `const volatile int' and
15148 PARM is `const T'. Then, T should be `volatile int'. */
15149 arg = cp_build_qualified_type_real
15150 (arg, cp_type_quals (arg) & ~cp_type_quals (parm), tf_none);
15151 if (arg == error_mark_node)
15154 /* Simple cases: Value already set, does match or doesn't. */
15155 if (targ != NULL_TREE && same_type_p (targ, arg))
15160 /* Make sure that ARG is not a variable-sized array. (Note
15161 that were talking about variable-sized arrays (like
15162 `int[n]'), rather than arrays of unknown size (like
15163 `int[]').) We'll get very confused by such a type since
15164 the bound of the array will not be computable in an
15165 instantiation. Besides, such types are not allowed in
15166 ISO C++, so we can do as we please here. */
15167 if (variably_modified_type_p (arg, NULL_TREE))
15170 /* Strip typedefs as in convert_template_argument. */
15171 arg = strip_typedefs (arg);
15174 /* If ARG is a parameter pack or an expansion, we cannot unify
15175 against it unless PARM is also a parameter pack. */
15176 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
15177 && !template_parameter_pack_p (parm))
15180 /* If the argument deduction results is a METHOD_TYPE,
15181 then there is a problem.
15182 METHOD_TYPE doesn't map to any real C++ type the result of
15183 the deduction can not be of that type. */
15184 if (TREE_CODE (arg) == METHOD_TYPE)
15187 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
15190 case TEMPLATE_PARM_INDEX:
15191 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
15192 if (tparm == error_mark_node)
15195 if (TEMPLATE_PARM_LEVEL (parm)
15196 != template_decl_level (tparm))
15197 /* The PARM is not one we're trying to unify. Just check
15198 to see if it matches ARG. */
15199 return !(TREE_CODE (arg) == TREE_CODE (parm)
15200 && cp_tree_equal (parm, arg));
15202 idx = TEMPLATE_PARM_IDX (parm);
15203 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
15206 return !cp_tree_equal (targ, arg);
15208 /* [temp.deduct.type] If, in the declaration of a function template
15209 with a non-type template-parameter, the non-type
15210 template-parameter is used in an expression in the function
15211 parameter-list and, if the corresponding template-argument is
15212 deduced, the template-argument type shall match the type of the
15213 template-parameter exactly, except that a template-argument
15214 deduced from an array bound may be of any integral type.
15215 The non-type parameter might use already deduced type parameters. */
15216 tparm = tsubst (TREE_TYPE (parm), targs, 0, NULL_TREE);
15217 if (!TREE_TYPE (arg))
15218 /* Template-parameter dependent expression. Just accept it for now.
15219 It will later be processed in convert_template_argument. */
15221 else if (same_type_p (TREE_TYPE (arg), tparm))
15223 else if ((strict & UNIFY_ALLOW_INTEGER)
15224 && (TREE_CODE (tparm) == INTEGER_TYPE
15225 || TREE_CODE (tparm) == BOOLEAN_TYPE))
15226 /* Convert the ARG to the type of PARM; the deduced non-type
15227 template argument must exactly match the types of the
15228 corresponding parameter. */
15229 arg = fold (build_nop (tparm, arg));
15230 else if (uses_template_parms (tparm))
15231 /* We haven't deduced the type of this parameter yet. Try again
15237 /* If ARG is a parameter pack or an expansion, we cannot unify
15238 against it unless PARM is also a parameter pack. */
15239 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
15240 && !TEMPLATE_PARM_PARAMETER_PACK (parm))
15243 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
15248 /* A pointer-to-member constant can be unified only with
15249 another constant. */
15250 if (TREE_CODE (arg) != PTRMEM_CST)
15253 /* Just unify the class member. It would be useless (and possibly
15254 wrong, depending on the strict flags) to unify also
15255 PTRMEM_CST_CLASS, because we want to be sure that both parm and
15256 arg refer to the same variable, even if through different
15257 classes. For instance:
15259 struct A { int x; };
15262 Unification of &A::x and &B::x must succeed. */
15263 return unify (tparms, targs, PTRMEM_CST_MEMBER (parm),
15264 PTRMEM_CST_MEMBER (arg), strict);
15269 if (TREE_CODE (arg) != POINTER_TYPE)
15272 /* [temp.deduct.call]
15274 A can be another pointer or pointer to member type that can
15275 be converted to the deduced A via a qualification
15276 conversion (_conv.qual_).
15278 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
15279 This will allow for additional cv-qualification of the
15280 pointed-to types if appropriate. */
15282 if (TREE_CODE (TREE_TYPE (arg)) == RECORD_TYPE)
15283 /* The derived-to-base conversion only persists through one
15284 level of pointers. */
15285 strict |= (strict_in & UNIFY_ALLOW_DERIVED);
15287 return unify (tparms, targs, TREE_TYPE (parm),
15288 TREE_TYPE (arg), strict);
15291 case REFERENCE_TYPE:
15292 if (TREE_CODE (arg) != REFERENCE_TYPE)
15294 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
15295 strict & UNIFY_ALLOW_MORE_CV_QUAL);
15298 if (TREE_CODE (arg) != ARRAY_TYPE)
15300 if ((TYPE_DOMAIN (parm) == NULL_TREE)
15301 != (TYPE_DOMAIN (arg) == NULL_TREE))
15303 if (TYPE_DOMAIN (parm) != NULL_TREE)
15310 /* Our representation of array types uses "N - 1" as the
15311 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
15312 not an integer constant. We cannot unify arbitrarily
15313 complex expressions, so we eliminate the MINUS_EXPRs
15315 parm_max = TYPE_MAX_VALUE (TYPE_DOMAIN (parm));
15316 parm_cst = TREE_CODE (parm_max) == INTEGER_CST;
15319 gcc_assert (TREE_CODE (parm_max) == MINUS_EXPR);
15320 parm_max = TREE_OPERAND (parm_max, 0);
15322 arg_max = TYPE_MAX_VALUE (TYPE_DOMAIN (arg));
15323 arg_cst = TREE_CODE (arg_max) == INTEGER_CST;
15326 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
15327 trying to unify the type of a variable with the type
15328 of a template parameter. For example:
15330 template <unsigned int N>
15331 void f (char (&) [N]);
15338 Here, the type of the ARG will be "int [g(i)]", and
15339 may be a SAVE_EXPR, etc. */
15340 if (TREE_CODE (arg_max) != MINUS_EXPR)
15342 arg_max = TREE_OPERAND (arg_max, 0);
15345 /* If only one of the bounds used a MINUS_EXPR, compensate
15346 by adding one to the other bound. */
15347 if (parm_cst && !arg_cst)
15348 parm_max = fold_build2_loc (input_location, PLUS_EXPR,
15352 else if (arg_cst && !parm_cst)
15353 arg_max = fold_build2_loc (input_location, PLUS_EXPR,
15358 if (unify (tparms, targs, parm_max, arg_max, UNIFY_ALLOW_INTEGER))
15361 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
15362 strict & UNIFY_ALLOW_MORE_CV_QUAL);
15369 case ENUMERAL_TYPE:
15371 if (TREE_CODE (arg) != TREE_CODE (parm))
15374 /* We have already checked cv-qualification at the top of the
15376 if (!same_type_ignoring_top_level_qualifiers_p (arg, parm))
15379 /* As far as unification is concerned, this wins. Later checks
15380 will invalidate it if necessary. */
15383 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
15384 /* Type INTEGER_CST can come from ordinary constant template args. */
15386 while (TREE_CODE (arg) == NOP_EXPR)
15387 arg = TREE_OPERAND (arg, 0);
15389 if (TREE_CODE (arg) != INTEGER_CST)
15391 return !tree_int_cst_equal (parm, arg);
15396 if (TREE_CODE (arg) != TREE_VEC)
15398 if (TREE_VEC_LENGTH (parm) != TREE_VEC_LENGTH (arg))
15400 for (i = 0; i < TREE_VEC_LENGTH (parm); ++i)
15401 if (unify (tparms, targs,
15402 TREE_VEC_ELT (parm, i), TREE_VEC_ELT (arg, i),
15410 if (TREE_CODE (arg) != TREE_CODE (parm))
15413 if (TYPE_PTRMEMFUNC_P (parm))
15415 if (!TYPE_PTRMEMFUNC_P (arg))
15418 return unify (tparms, targs,
15419 TYPE_PTRMEMFUNC_FN_TYPE (parm),
15420 TYPE_PTRMEMFUNC_FN_TYPE (arg),
15424 if (CLASSTYPE_TEMPLATE_INFO (parm))
15426 tree t = NULL_TREE;
15428 if (strict_in & UNIFY_ALLOW_DERIVED)
15430 /* First, we try to unify the PARM and ARG directly. */
15431 t = try_class_unification (tparms, targs,
15436 /* Fallback to the special case allowed in
15437 [temp.deduct.call]:
15439 If P is a class, and P has the form
15440 template-id, then A can be a derived class of
15441 the deduced A. Likewise, if P is a pointer to
15442 a class of the form template-id, A can be a
15443 pointer to a derived class pointed to by the
15445 t = get_template_base (tparms, targs, parm, arg);
15451 else if (CLASSTYPE_TEMPLATE_INFO (arg)
15452 && (CLASSTYPE_TI_TEMPLATE (parm)
15453 == CLASSTYPE_TI_TEMPLATE (arg)))
15454 /* Perhaps PARM is something like S<U> and ARG is S<int>.
15455 Then, we should unify `int' and `U'. */
15458 /* There's no chance of unification succeeding. */
15461 return unify (tparms, targs, CLASSTYPE_TI_ARGS (parm),
15462 CLASSTYPE_TI_ARGS (t), UNIFY_ALLOW_NONE);
15464 else if (!same_type_ignoring_top_level_qualifiers_p (parm, arg))
15469 case FUNCTION_TYPE:
15471 unsigned int nargs;
15476 if (TREE_CODE (arg) != TREE_CODE (parm))
15479 /* CV qualifications for methods can never be deduced, they must
15480 match exactly. We need to check them explicitly here,
15481 because type_unification_real treats them as any other
15482 cv-qualified parameter. */
15483 if (TREE_CODE (parm) == METHOD_TYPE
15484 && (!check_cv_quals_for_unify
15486 TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (arg))),
15487 TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (parm))))))
15490 if (unify (tparms, targs, TREE_TYPE (parm),
15491 TREE_TYPE (arg), UNIFY_ALLOW_NONE))
15494 nargs = list_length (TYPE_ARG_TYPES (arg));
15495 args = XALLOCAVEC (tree, nargs);
15496 for (a = TYPE_ARG_TYPES (arg), i = 0;
15497 a != NULL_TREE && a != void_list_node;
15498 a = TREE_CHAIN (a), ++i)
15499 args[i] = TREE_VALUE (a);
15502 return type_unification_real (tparms, targs, TYPE_ARG_TYPES (parm),
15503 args, nargs, 1, DEDUCE_EXACT,
15508 /* Unify a pointer to member with a pointer to member function, which
15509 deduces the type of the member as a function type. */
15510 if (TYPE_PTRMEMFUNC_P (arg))
15515 /* Check top-level cv qualifiers */
15516 if (!check_cv_quals_for_unify (UNIFY_ALLOW_NONE, arg, parm))
15519 if (unify (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
15520 TYPE_PTRMEMFUNC_OBJECT_TYPE (arg), UNIFY_ALLOW_NONE))
15523 /* Determine the type of the function we are unifying against. */
15524 method_type = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (arg));
15526 build_function_type (TREE_TYPE (method_type),
15527 TREE_CHAIN (TYPE_ARG_TYPES (method_type)));
15529 /* Extract the cv-qualifiers of the member function from the
15530 implicit object parameter and place them on the function
15531 type to be restored later. */
15532 fntype = apply_memfn_quals (fntype, type_memfn_quals (method_type));
15533 return unify (tparms, targs, TREE_TYPE (parm), fntype, strict);
15536 if (TREE_CODE (arg) != OFFSET_TYPE)
15538 if (unify (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
15539 TYPE_OFFSET_BASETYPE (arg), UNIFY_ALLOW_NONE))
15541 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
15545 if (DECL_TEMPLATE_PARM_P (parm))
15546 return unify (tparms, targs, DECL_INITIAL (parm), arg, strict);
15547 if (arg != integral_constant_value (parm))
15552 case TEMPLATE_DECL:
15553 /* Matched cases are handled by the ARG == PARM test above. */
15557 /* A non-type template parameter that is a variable should be a
15558 an integral constant, in which case, it whould have been
15559 folded into its (constant) value. So we should not be getting
15560 a variable here. */
15561 gcc_unreachable ();
15563 case TYPE_ARGUMENT_PACK:
15564 case NONTYPE_ARGUMENT_PACK:
15566 tree packed_parms = ARGUMENT_PACK_ARGS (parm);
15567 tree packed_args = ARGUMENT_PACK_ARGS (arg);
15568 int i, len = TREE_VEC_LENGTH (packed_parms);
15569 int argslen = TREE_VEC_LENGTH (packed_args);
15570 int parm_variadic_p = 0;
15572 for (i = 0; i < len; ++i)
15574 if (PACK_EXPANSION_P (TREE_VEC_ELT (packed_parms, i)))
15577 /* We can unify against something with a trailing
15579 parm_variadic_p = 1;
15581 /* Since there is something following the pack
15582 expansion, we cannot unify this template argument
15589 /* If we don't have enough arguments to satisfy the parameters
15590 (not counting the pack expression at the end), or we have
15591 too many arguments for a parameter list that doesn't end in
15592 a pack expression, we can't unify. */
15593 if (argslen < (len - parm_variadic_p)
15594 || (argslen > len && !parm_variadic_p))
15597 /* Unify all of the parameters that precede the (optional)
15598 pack expression. */
15599 for (i = 0; i < len - parm_variadic_p; ++i)
15601 if (unify (tparms, targs, TREE_VEC_ELT (packed_parms, i),
15602 TREE_VEC_ELT (packed_args, i), strict))
15606 if (parm_variadic_p)
15607 return unify_pack_expansion (tparms, targs,
15608 packed_parms, packed_args,
15609 strict, /*call_args_p=*/false,
15617 case DECLTYPE_TYPE:
15618 /* Cannot deduce anything from TYPEOF_TYPE or DECLTYPE_TYPE
15623 /* Unification fails if we hit an error node. */
15627 gcc_assert (EXPR_P (parm));
15629 /* We must be looking at an expression. This can happen with
15633 void foo(S<I>, S<I + 2>);
15635 This is a "nondeduced context":
15639 The nondeduced contexts are:
15641 --A type that is a template-id in which one or more of
15642 the template-arguments is an expression that references
15643 a template-parameter.
15645 In these cases, we assume deduction succeeded, but don't
15646 actually infer any unifications. */
15648 if (!uses_template_parms (parm)
15649 && !template_args_equal (parm, arg))
15656 /* Note that DECL can be defined in this translation unit, if
15660 mark_definable (tree decl)
15663 DECL_NOT_REALLY_EXTERN (decl) = 1;
15664 FOR_EACH_CLONE (clone, decl)
15665 DECL_NOT_REALLY_EXTERN (clone) = 1;
15668 /* Called if RESULT is explicitly instantiated, or is a member of an
15669 explicitly instantiated class. */
15672 mark_decl_instantiated (tree result, int extern_p)
15674 SET_DECL_EXPLICIT_INSTANTIATION (result);
15676 /* If this entity has already been written out, it's too late to
15677 make any modifications. */
15678 if (TREE_ASM_WRITTEN (result))
15681 if (TREE_CODE (result) != FUNCTION_DECL)
15682 /* The TREE_PUBLIC flag for function declarations will have been
15683 set correctly by tsubst. */
15684 TREE_PUBLIC (result) = 1;
15686 /* This might have been set by an earlier implicit instantiation. */
15687 DECL_COMDAT (result) = 0;
15690 DECL_NOT_REALLY_EXTERN (result) = 0;
15693 mark_definable (result);
15694 /* Always make artificials weak. */
15695 if (DECL_ARTIFICIAL (result) && flag_weak)
15696 comdat_linkage (result);
15697 /* For WIN32 we also want to put explicit instantiations in
15698 linkonce sections. */
15699 else if (TREE_PUBLIC (result))
15700 maybe_make_one_only (result);
15703 /* If EXTERN_P, then this function will not be emitted -- unless
15704 followed by an explicit instantiation, at which point its linkage
15705 will be adjusted. If !EXTERN_P, then this function will be
15706 emitted here. In neither circumstance do we want
15707 import_export_decl to adjust the linkage. */
15708 DECL_INTERFACE_KNOWN (result) = 1;
15711 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
15712 important template arguments. If any are missing, we check whether
15713 they're important by using error_mark_node for substituting into any
15714 args that were used for partial ordering (the ones between ARGS and END)
15715 and seeing if it bubbles up. */
15718 check_undeduced_parms (tree targs, tree args, tree end)
15720 bool found = false;
15722 for (i = TREE_VEC_LENGTH (targs) - 1; i >= 0; --i)
15723 if (TREE_VEC_ELT (targs, i) == NULL_TREE)
15726 TREE_VEC_ELT (targs, i) = error_mark_node;
15730 for (; args != end; args = TREE_CHAIN (args))
15732 tree substed = tsubst (TREE_VALUE (args), targs, tf_none, NULL_TREE);
15733 if (substed == error_mark_node)
15740 /* Given two function templates PAT1 and PAT2, return:
15742 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
15743 -1 if PAT2 is more specialized than PAT1.
15744 0 if neither is more specialized.
15746 LEN indicates the number of parameters we should consider
15747 (defaulted parameters should not be considered).
15749 The 1998 std underspecified function template partial ordering, and
15750 DR214 addresses the issue. We take pairs of arguments, one from
15751 each of the templates, and deduce them against each other. One of
15752 the templates will be more specialized if all the *other*
15753 template's arguments deduce against its arguments and at least one
15754 of its arguments *does* *not* deduce against the other template's
15755 corresponding argument. Deduction is done as for class templates.
15756 The arguments used in deduction have reference and top level cv
15757 qualifiers removed. Iff both arguments were originally reference
15758 types *and* deduction succeeds in both directions, the template
15759 with the more cv-qualified argument wins for that pairing (if
15760 neither is more cv-qualified, they both are equal). Unlike regular
15761 deduction, after all the arguments have been deduced in this way,
15762 we do *not* verify the deduced template argument values can be
15763 substituted into non-deduced contexts.
15765 The logic can be a bit confusing here, because we look at deduce1 and
15766 targs1 to see if pat2 is at least as specialized, and vice versa; if we
15767 can find template arguments for pat1 to make arg1 look like arg2, that
15768 means that arg2 is at least as specialized as arg1. */
15771 more_specialized_fn (tree pat1, tree pat2, int len)
15773 tree decl1 = DECL_TEMPLATE_RESULT (pat1);
15774 tree decl2 = DECL_TEMPLATE_RESULT (pat2);
15775 tree targs1 = make_tree_vec (DECL_NTPARMS (pat1));
15776 tree targs2 = make_tree_vec (DECL_NTPARMS (pat2));
15777 tree tparms1 = DECL_INNERMOST_TEMPLATE_PARMS (pat1);
15778 tree tparms2 = DECL_INNERMOST_TEMPLATE_PARMS (pat2);
15779 tree args1 = TYPE_ARG_TYPES (TREE_TYPE (decl1));
15780 tree args2 = TYPE_ARG_TYPES (TREE_TYPE (decl2));
15781 tree origs1, origs2;
15782 bool lose1 = false;
15783 bool lose2 = false;
15785 /* Remove the this parameter from non-static member functions. If
15786 one is a non-static member function and the other is not a static
15787 member function, remove the first parameter from that function
15788 also. This situation occurs for operator functions where we
15789 locate both a member function (with this pointer) and non-member
15790 operator (with explicit first operand). */
15791 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl1))
15793 len--; /* LEN is the number of significant arguments for DECL1 */
15794 args1 = TREE_CHAIN (args1);
15795 if (!DECL_STATIC_FUNCTION_P (decl2))
15796 args2 = TREE_CHAIN (args2);
15798 else if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl2))
15800 args2 = TREE_CHAIN (args2);
15801 if (!DECL_STATIC_FUNCTION_P (decl1))
15804 args1 = TREE_CHAIN (args1);
15808 /* If only one is a conversion operator, they are unordered. */
15809 if (DECL_CONV_FN_P (decl1) != DECL_CONV_FN_P (decl2))
15812 /* Consider the return type for a conversion function */
15813 if (DECL_CONV_FN_P (decl1))
15815 args1 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl1)), args1);
15816 args2 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl2)), args2);
15820 processing_template_decl++;
15826 /* Stop when an ellipsis is seen. */
15827 && args1 != NULL_TREE && args2 != NULL_TREE)
15829 tree arg1 = TREE_VALUE (args1);
15830 tree arg2 = TREE_VALUE (args2);
15831 int deduce1, deduce2;
15835 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
15836 && TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
15838 /* When both arguments are pack expansions, we need only
15839 unify the patterns themselves. */
15840 arg1 = PACK_EXPANSION_PATTERN (arg1);
15841 arg2 = PACK_EXPANSION_PATTERN (arg2);
15843 /* This is the last comparison we need to do. */
15847 if (TREE_CODE (arg1) == REFERENCE_TYPE)
15849 arg1 = TREE_TYPE (arg1);
15850 quals1 = cp_type_quals (arg1);
15853 if (TREE_CODE (arg2) == REFERENCE_TYPE)
15855 arg2 = TREE_TYPE (arg2);
15856 quals2 = cp_type_quals (arg2);
15859 if ((quals1 < 0) != (quals2 < 0))
15861 /* Only of the args is a reference, see if we should apply
15862 array/function pointer decay to it. This is not part of
15863 DR214, but is, IMHO, consistent with the deduction rules
15864 for the function call itself, and with our earlier
15865 implementation of the underspecified partial ordering
15866 rules. (nathan). */
15869 switch (TREE_CODE (arg1))
15872 arg1 = TREE_TYPE (arg1);
15874 case FUNCTION_TYPE:
15875 arg1 = build_pointer_type (arg1);
15884 switch (TREE_CODE (arg2))
15887 arg2 = TREE_TYPE (arg2);
15889 case FUNCTION_TYPE:
15890 arg2 = build_pointer_type (arg2);
15899 arg1 = TYPE_MAIN_VARIANT (arg1);
15900 arg2 = TYPE_MAIN_VARIANT (arg2);
15902 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION)
15904 int i, len2 = list_length (args2);
15905 tree parmvec = make_tree_vec (1);
15906 tree argvec = make_tree_vec (len2);
15909 /* Setup the parameter vector, which contains only ARG1. */
15910 TREE_VEC_ELT (parmvec, 0) = arg1;
15912 /* Setup the argument vector, which contains the remaining
15914 for (i = 0; i < len2; i++, ta = TREE_CHAIN (ta))
15915 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
15917 deduce1 = !unify_pack_expansion (tparms1, targs1, parmvec,
15918 argvec, UNIFY_ALLOW_NONE,
15919 /*call_args_p=*/false,
15922 /* We cannot deduce in the other direction, because ARG1 is
15923 a pack expansion but ARG2 is not. */
15926 else if (TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
15928 int i, len1 = list_length (args1);
15929 tree parmvec = make_tree_vec (1);
15930 tree argvec = make_tree_vec (len1);
15933 /* Setup the parameter vector, which contains only ARG1. */
15934 TREE_VEC_ELT (parmvec, 0) = arg2;
15936 /* Setup the argument vector, which contains the remaining
15938 for (i = 0; i < len1; i++, ta = TREE_CHAIN (ta))
15939 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
15941 deduce2 = !unify_pack_expansion (tparms2, targs2, parmvec,
15942 argvec, UNIFY_ALLOW_NONE,
15943 /*call_args_p=*/false,
15946 /* We cannot deduce in the other direction, because ARG2 is
15947 a pack expansion but ARG1 is not.*/
15953 /* The normal case, where neither argument is a pack
15955 deduce1 = !unify (tparms1, targs1, arg1, arg2, UNIFY_ALLOW_NONE);
15956 deduce2 = !unify (tparms2, targs2, arg2, arg1, UNIFY_ALLOW_NONE);
15959 /* If we couldn't deduce arguments for tparms1 to make arg1 match
15960 arg2, then arg2 is not as specialized as arg1. */
15966 /* "If, for a given type, deduction succeeds in both directions
15967 (i.e., the types are identical after the transformations above)
15968 and if the type from the argument template is more cv-qualified
15969 than the type from the parameter template (as described above)
15970 that type is considered to be more specialized than the other. If
15971 neither type is more cv-qualified than the other then neither type
15972 is more specialized than the other." */
15974 if (deduce1 && deduce2
15975 && quals1 != quals2 && quals1 >= 0 && quals2 >= 0)
15977 if ((quals1 & quals2) == quals2)
15979 if ((quals1 & quals2) == quals1)
15983 if (lose1 && lose2)
15984 /* We've failed to deduce something in either direction.
15985 These must be unordered. */
15988 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
15989 || TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
15990 /* We have already processed all of the arguments in our
15991 handing of the pack expansion type. */
15994 args1 = TREE_CHAIN (args1);
15995 args2 = TREE_CHAIN (args2);
15998 /* "In most cases, all template parameters must have values in order for
15999 deduction to succeed, but for partial ordering purposes a template
16000 parameter may remain without a value provided it is not used in the
16001 types being used for partial ordering."
16003 Thus, if we are missing any of the targs1 we need to substitute into
16004 origs1, then pat2 is not as specialized as pat1. This can happen when
16005 there is a nondeduced context. */
16006 if (!lose2 && check_undeduced_parms (targs1, origs1, args1))
16008 if (!lose1 && check_undeduced_parms (targs2, origs2, args2))
16011 processing_template_decl--;
16013 /* All things being equal, if the next argument is a pack expansion
16014 for one function but not for the other, prefer the
16015 non-variadic function. FIXME this is bogus; see c++/41958. */
16017 && args1 && TREE_VALUE (args1)
16018 && args2 && TREE_VALUE (args2))
16020 lose1 = TREE_CODE (TREE_VALUE (args1)) == TYPE_PACK_EXPANSION;
16021 lose2 = TREE_CODE (TREE_VALUE (args2)) == TYPE_PACK_EXPANSION;
16024 if (lose1 == lose2)
16032 /* Determine which of two partial specializations is more specialized.
16034 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
16035 to the first partial specialization. The TREE_VALUE is the
16036 innermost set of template parameters for the partial
16037 specialization. PAT2 is similar, but for the second template.
16039 Return 1 if the first partial specialization is more specialized;
16040 -1 if the second is more specialized; 0 if neither is more
16043 See [temp.class.order] for information about determining which of
16044 two templates is more specialized. */
16047 more_specialized_class (tree pat1, tree pat2)
16052 bool any_deductions = false;
16054 tmpl1 = TREE_TYPE (pat1);
16055 tmpl2 = TREE_TYPE (pat2);
16057 /* Just like what happens for functions, if we are ordering between
16058 different class template specializations, we may encounter dependent
16059 types in the arguments, and we need our dependency check functions
16060 to behave correctly. */
16061 ++processing_template_decl;
16062 targs = get_class_bindings (TREE_VALUE (pat1),
16063 CLASSTYPE_TI_ARGS (tmpl1),
16064 CLASSTYPE_TI_ARGS (tmpl2));
16068 any_deductions = true;
16071 targs = get_class_bindings (TREE_VALUE (pat2),
16072 CLASSTYPE_TI_ARGS (tmpl2),
16073 CLASSTYPE_TI_ARGS (tmpl1));
16077 any_deductions = true;
16079 --processing_template_decl;
16081 /* In the case of a tie where at least one of the class templates
16082 has a parameter pack at the end, the template with the most
16083 non-packed parameters wins. */
16086 && (template_args_variadic_p (TREE_PURPOSE (pat1))
16087 || template_args_variadic_p (TREE_PURPOSE (pat2))))
16089 tree args1 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat1));
16090 tree args2 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat2));
16091 int len1 = TREE_VEC_LENGTH (args1);
16092 int len2 = TREE_VEC_LENGTH (args2);
16094 /* We don't count the pack expansion at the end. */
16095 if (template_args_variadic_p (TREE_PURPOSE (pat1)))
16097 if (template_args_variadic_p (TREE_PURPOSE (pat2)))
16102 else if (len1 < len2)
16109 /* Return the template arguments that will produce the function signature
16110 DECL from the function template FN, with the explicit template
16111 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
16112 also match. Return NULL_TREE if no satisfactory arguments could be
16116 get_bindings (tree fn, tree decl, tree explicit_args, bool check_rettype)
16118 int ntparms = DECL_NTPARMS (fn);
16119 tree targs = make_tree_vec (ntparms);
16121 tree decl_arg_types;
16123 unsigned int nargs, ix;
16126 /* Substitute the explicit template arguments into the type of DECL.
16127 The call to fn_type_unification will handle substitution into the
16129 decl_type = TREE_TYPE (decl);
16130 if (explicit_args && uses_template_parms (decl_type))
16133 tree converted_args;
16135 if (DECL_TEMPLATE_INFO (decl))
16136 tmpl = DECL_TI_TEMPLATE (decl);
16138 /* We can get here for some invalid specializations. */
16142 = coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
16143 explicit_args, NULL_TREE,
16145 /*require_all_args=*/false,
16146 /*use_default_args=*/false);
16147 if (converted_args == error_mark_node)
16150 decl_type = tsubst (decl_type, converted_args, tf_none, NULL_TREE);
16151 if (decl_type == error_mark_node)
16155 /* Never do unification on the 'this' parameter. */
16156 decl_arg_types = skip_artificial_parms_for (decl,
16157 TYPE_ARG_TYPES (decl_type));
16159 nargs = list_length (decl_arg_types);
16160 args = XALLOCAVEC (tree, nargs);
16161 for (arg = decl_arg_types, ix = 0;
16162 arg != NULL_TREE && arg != void_list_node;
16163 arg = TREE_CHAIN (arg), ++ix)
16164 args[ix] = TREE_VALUE (arg);
16166 if (fn_type_unification (fn, explicit_args, targs,
16168 (check_rettype || DECL_CONV_FN_P (fn)
16169 ? TREE_TYPE (decl_type) : NULL_TREE),
16170 DEDUCE_EXACT, LOOKUP_NORMAL))
16176 /* Return the innermost template arguments that, when applied to a
16177 template specialization whose innermost template parameters are
16178 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
16181 For example, suppose we have:
16183 template <class T, class U> struct S {};
16184 template <class T> struct S<T*, int> {};
16186 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
16187 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
16188 int}. The resulting vector will be {double}, indicating that `T'
16189 is bound to `double'. */
16192 get_class_bindings (tree tparms, tree spec_args, tree args)
16194 int i, ntparms = TREE_VEC_LENGTH (tparms);
16196 tree innermost_deduced_args;
16198 innermost_deduced_args = make_tree_vec (ntparms);
16199 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
16201 deduced_args = copy_node (args);
16202 SET_TMPL_ARGS_LEVEL (deduced_args,
16203 TMPL_ARGS_DEPTH (deduced_args),
16204 innermost_deduced_args);
16207 deduced_args = innermost_deduced_args;
16209 if (unify (tparms, deduced_args,
16210 INNERMOST_TEMPLATE_ARGS (spec_args),
16211 INNERMOST_TEMPLATE_ARGS (args),
16215 for (i = 0; i < ntparms; ++i)
16216 if (! TREE_VEC_ELT (innermost_deduced_args, i))
16219 /* Verify that nondeduced template arguments agree with the type
16220 obtained from argument deduction.
16224 struct A { typedef int X; };
16225 template <class T, class U> struct C {};
16226 template <class T> struct C<T, typename T::X> {};
16228 Then with the instantiation `C<A, int>', we can deduce that
16229 `T' is `A' but unify () does not check whether `typename T::X'
16231 spec_args = tsubst (spec_args, deduced_args, tf_none, NULL_TREE);
16232 if (spec_args == error_mark_node
16233 /* We only need to check the innermost arguments; the other
16234 arguments will always agree. */
16235 || !comp_template_args (INNERMOST_TEMPLATE_ARGS (spec_args),
16236 INNERMOST_TEMPLATE_ARGS (args)))
16239 /* Now that we have bindings for all of the template arguments,
16240 ensure that the arguments deduced for the template template
16241 parameters have compatible template parameter lists. See the use
16242 of template_template_parm_bindings_ok_p in fn_type_unification
16243 for more information. */
16244 if (!template_template_parm_bindings_ok_p (tparms, deduced_args))
16247 return deduced_args;
16250 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
16251 Return the TREE_LIST node with the most specialized template, if
16252 any. If there is no most specialized template, the error_mark_node
16255 Note that this function does not look at, or modify, the
16256 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
16257 returned is one of the elements of INSTANTIATIONS, callers may
16258 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
16259 and retrieve it from the value returned. */
16262 most_specialized_instantiation (tree templates)
16266 ++processing_template_decl;
16269 for (fn = TREE_CHAIN (templates); fn; fn = TREE_CHAIN (fn))
16273 if (get_bindings (TREE_VALUE (champ),
16274 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
16275 NULL_TREE, /*check_ret=*/false))
16278 if (get_bindings (TREE_VALUE (fn),
16279 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
16280 NULL_TREE, /*check_ret=*/false))
16287 /* Equally specialized, move to next function. If there
16288 is no next function, nothing's most specialized. */
16289 fn = TREE_CHAIN (fn);
16297 /* Now verify that champ is better than everything earlier in the
16298 instantiation list. */
16299 for (fn = templates; fn != champ; fn = TREE_CHAIN (fn))
16300 if (get_bindings (TREE_VALUE (champ),
16301 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
16302 NULL_TREE, /*check_ret=*/false)
16303 || !get_bindings (TREE_VALUE (fn),
16304 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
16305 NULL_TREE, /*check_ret=*/false))
16311 processing_template_decl--;
16314 return error_mark_node;
16319 /* If DECL is a specialization of some template, return the most
16320 general such template. Otherwise, returns NULL_TREE.
16322 For example, given:
16324 template <class T> struct S { template <class U> void f(U); };
16326 if TMPL is `template <class U> void S<int>::f(U)' this will return
16327 the full template. This function will not trace past partial
16328 specializations, however. For example, given in addition:
16330 template <class T> struct S<T*> { template <class U> void f(U); };
16332 if TMPL is `template <class U> void S<int*>::f(U)' this will return
16333 `template <class T> template <class U> S<T*>::f(U)'. */
16336 most_general_template (tree decl)
16338 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
16339 an immediate specialization. */
16340 if (TREE_CODE (decl) == FUNCTION_DECL)
16342 if (DECL_TEMPLATE_INFO (decl)) {
16343 decl = DECL_TI_TEMPLATE (decl);
16345 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
16346 template friend. */
16347 if (TREE_CODE (decl) != TEMPLATE_DECL)
16353 /* Look for more and more general templates. */
16354 while (DECL_TEMPLATE_INFO (decl))
16356 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
16357 (See cp-tree.h for details.) */
16358 if (TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
16361 if (CLASS_TYPE_P (TREE_TYPE (decl))
16362 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)))
16365 /* Stop if we run into an explicitly specialized class template. */
16366 if (!DECL_NAMESPACE_SCOPE_P (decl)
16367 && DECL_CONTEXT (decl)
16368 && CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (decl)))
16371 decl = DECL_TI_TEMPLATE (decl);
16377 /* Return the most specialized of the class template partial
16378 specializations of TMPL which can produce TYPE, a specialization of
16379 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
16380 a _TYPE node corresponding to the partial specialization, while the
16381 TREE_PURPOSE is the set of template arguments that must be
16382 substituted into the TREE_TYPE in order to generate TYPE.
16384 If the choice of partial specialization is ambiguous, a diagnostic
16385 is issued, and the error_mark_node is returned. If there are no
16386 partial specializations of TMPL matching TYPE, then NULL_TREE is
16390 most_specialized_class (tree type, tree tmpl, tsubst_flags_t complain)
16392 tree list = NULL_TREE;
16398 tree outer_args = NULL_TREE;
16400 tmpl = most_general_template (tmpl);
16401 args = CLASSTYPE_TI_ARGS (type);
16403 /* For determining which partial specialization to use, only the
16404 innermost args are interesting. */
16405 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
16407 outer_args = strip_innermost_template_args (args, 1);
16408 args = INNERMOST_TEMPLATE_ARGS (args);
16411 for (t = DECL_TEMPLATE_SPECIALIZATIONS (tmpl); t; t = TREE_CHAIN (t))
16413 tree partial_spec_args;
16415 tree parms = TREE_VALUE (t);
16417 partial_spec_args = CLASSTYPE_TI_ARGS (TREE_TYPE (t));
16419 ++processing_template_decl;
16425 /* Discard the outer levels of args, and then substitute in the
16426 template args from the enclosing class. */
16427 partial_spec_args = INNERMOST_TEMPLATE_ARGS (partial_spec_args);
16428 partial_spec_args = tsubst_template_args
16429 (partial_spec_args, outer_args, tf_none, NULL_TREE);
16431 /* PARMS already refers to just the innermost parms, but the
16432 template parms in partial_spec_args had their levels lowered
16433 by tsubst, so we need to do the same for the parm list. We
16434 can't just tsubst the TREE_VEC itself, as tsubst wants to
16435 treat a TREE_VEC as an argument vector. */
16436 parms = copy_node (parms);
16437 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
16438 TREE_VEC_ELT (parms, i) =
16439 tsubst (TREE_VEC_ELT (parms, i), outer_args, tf_none, NULL_TREE);
16443 partial_spec_args =
16444 coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
16445 add_to_template_args (outer_args,
16446 partial_spec_args),
16448 /*require_all_args=*/true,
16449 /*use_default_args=*/true);
16451 --processing_template_decl;
16453 if (partial_spec_args == error_mark_node)
16454 return error_mark_node;
16456 spec_args = get_class_bindings (parms,
16462 spec_args = add_to_template_args (outer_args, spec_args);
16463 list = tree_cons (spec_args, TREE_VALUE (t), list);
16464 TREE_TYPE (list) = TREE_TYPE (t);
16471 ambiguous_p = false;
16474 t = TREE_CHAIN (t);
16475 for (; t; t = TREE_CHAIN (t))
16477 fate = more_specialized_class (champ, t);
16484 t = TREE_CHAIN (t);
16487 ambiguous_p = true;
16496 for (t = list; t && t != champ; t = TREE_CHAIN (t))
16498 fate = more_specialized_class (champ, t);
16501 ambiguous_p = true;
16509 char *spaces = NULL;
16510 if (!(complain & tf_error))
16511 return error_mark_node;
16512 error ("ambiguous class template instantiation for %q#T", type);
16513 str = ngettext ("candidate is:", "candidates are:", list_length (list));
16514 for (t = list; t; t = TREE_CHAIN (t))
16516 error ("%s %+#T", spaces ? spaces : str, TREE_TYPE (t));
16517 spaces = spaces ? spaces : get_spaces (str);
16520 return error_mark_node;
16526 /* Explicitly instantiate DECL. */
16529 do_decl_instantiation (tree decl, tree storage)
16531 tree result = NULL_TREE;
16534 if (!decl || decl == error_mark_node)
16535 /* An error occurred, for which grokdeclarator has already issued
16536 an appropriate message. */
16538 else if (! DECL_LANG_SPECIFIC (decl))
16540 error ("explicit instantiation of non-template %q#D", decl);
16543 else if (TREE_CODE (decl) == VAR_DECL)
16545 /* There is an asymmetry here in the way VAR_DECLs and
16546 FUNCTION_DECLs are handled by grokdeclarator. In the case of
16547 the latter, the DECL we get back will be marked as a
16548 template instantiation, and the appropriate
16549 DECL_TEMPLATE_INFO will be set up. This does not happen for
16550 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
16551 should handle VAR_DECLs as it currently handles
16553 if (!DECL_CLASS_SCOPE_P (decl))
16555 error ("%qD is not a static data member of a class template", decl);
16558 result = lookup_field (DECL_CONTEXT (decl), DECL_NAME (decl), 0, false);
16559 if (!result || TREE_CODE (result) != VAR_DECL)
16561 error ("no matching template for %qD found", decl);
16564 if (!same_type_p (TREE_TYPE (result), TREE_TYPE (decl)))
16566 error ("type %qT for explicit instantiation %qD does not match "
16567 "declared type %qT", TREE_TYPE (result), decl,
16572 else if (TREE_CODE (decl) != FUNCTION_DECL)
16574 error ("explicit instantiation of %q#D", decl);
16580 /* Check for various error cases. Note that if the explicit
16581 instantiation is valid the RESULT will currently be marked as an
16582 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
16583 until we get here. */
16585 if (DECL_TEMPLATE_SPECIALIZATION (result))
16587 /* DR 259 [temp.spec].
16589 Both an explicit instantiation and a declaration of an explicit
16590 specialization shall not appear in a program unless the explicit
16591 instantiation follows a declaration of the explicit specialization.
16593 For a given set of template parameters, if an explicit
16594 instantiation of a template appears after a declaration of an
16595 explicit specialization for that template, the explicit
16596 instantiation has no effect. */
16599 else if (DECL_EXPLICIT_INSTANTIATION (result))
16603 No program shall explicitly instantiate any template more
16606 We check DECL_NOT_REALLY_EXTERN so as not to complain when
16607 the first instantiation was `extern' and the second is not,
16608 and EXTERN_P for the opposite case. */
16609 if (DECL_NOT_REALLY_EXTERN (result) && !extern_p)
16610 permerror (input_location, "duplicate explicit instantiation of %q#D", result);
16611 /* If an "extern" explicit instantiation follows an ordinary
16612 explicit instantiation, the template is instantiated. */
16616 else if (!DECL_IMPLICIT_INSTANTIATION (result))
16618 error ("no matching template for %qD found", result);
16621 else if (!DECL_TEMPLATE_INFO (result))
16623 permerror (input_location, "explicit instantiation of non-template %q#D", result);
16627 if (storage == NULL_TREE)
16629 else if (storage == ridpointers[(int) RID_EXTERN])
16631 if (!in_system_header && (cxx_dialect == cxx98))
16632 pedwarn (input_location, OPT_pedantic,
16633 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
16638 error ("storage class %qD applied to template instantiation", storage);
16640 check_explicit_instantiation_namespace (result);
16641 mark_decl_instantiated (result, extern_p);
16643 instantiate_decl (result, /*defer_ok=*/1,
16644 /*expl_inst_class_mem_p=*/false);
16648 mark_class_instantiated (tree t, int extern_p)
16650 SET_CLASSTYPE_EXPLICIT_INSTANTIATION (t);
16651 SET_CLASSTYPE_INTERFACE_KNOWN (t);
16652 CLASSTYPE_INTERFACE_ONLY (t) = extern_p;
16653 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (t)) = extern_p;
16656 CLASSTYPE_DEBUG_REQUESTED (t) = 1;
16657 rest_of_type_compilation (t, 1);
16661 /* Called from do_type_instantiation through binding_table_foreach to
16662 do recursive instantiation for the type bound in ENTRY. */
16664 bt_instantiate_type_proc (binding_entry entry, void *data)
16666 tree storage = *(tree *) data;
16668 if (MAYBE_CLASS_TYPE_P (entry->type)
16669 && !uses_template_parms (CLASSTYPE_TI_ARGS (entry->type)))
16670 do_type_instantiation (TYPE_MAIN_DECL (entry->type), storage, 0);
16673 /* Called from do_type_instantiation to instantiate a member
16674 (a member function or a static member variable) of an
16675 explicitly instantiated class template. */
16677 instantiate_class_member (tree decl, int extern_p)
16679 mark_decl_instantiated (decl, extern_p);
16681 instantiate_decl (decl, /*defer_ok=*/1,
16682 /*expl_inst_class_mem_p=*/true);
16685 /* Perform an explicit instantiation of template class T. STORAGE, if
16686 non-null, is the RID for extern, inline or static. COMPLAIN is
16687 nonzero if this is called from the parser, zero if called recursively,
16688 since the standard is unclear (as detailed below). */
16691 do_type_instantiation (tree t, tree storage, tsubst_flags_t complain)
16696 int previous_instantiation_extern_p = 0;
16698 if (TREE_CODE (t) == TYPE_DECL)
16701 if (! CLASS_TYPE_P (t) || ! CLASSTYPE_TEMPLATE_INFO (t))
16703 error ("explicit instantiation of non-template type %qT", t);
16709 if (!COMPLETE_TYPE_P (t))
16711 if (complain & tf_error)
16712 error ("explicit instantiation of %q#T before definition of template",
16717 if (storage != NULL_TREE)
16719 if (!in_system_header)
16721 if (storage == ridpointers[(int) RID_EXTERN])
16723 if (cxx_dialect == cxx98)
16724 pedwarn (input_location, OPT_pedantic,
16725 "ISO C++ 1998 forbids the use of %<extern%> on "
16726 "explicit instantiations");
16729 pedwarn (input_location, OPT_pedantic,
16730 "ISO C++ forbids the use of %qE"
16731 " on explicit instantiations", storage);
16734 if (storage == ridpointers[(int) RID_INLINE])
16736 else if (storage == ridpointers[(int) RID_EXTERN])
16738 else if (storage == ridpointers[(int) RID_STATIC])
16742 error ("storage class %qD applied to template instantiation",
16748 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (t))
16750 /* DR 259 [temp.spec].
16752 Both an explicit instantiation and a declaration of an explicit
16753 specialization shall not appear in a program unless the explicit
16754 instantiation follows a declaration of the explicit specialization.
16756 For a given set of template parameters, if an explicit
16757 instantiation of a template appears after a declaration of an
16758 explicit specialization for that template, the explicit
16759 instantiation has no effect. */
16762 else if (CLASSTYPE_EXPLICIT_INSTANTIATION (t))
16766 No program shall explicitly instantiate any template more
16769 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
16770 instantiation was `extern'. If EXTERN_P then the second is.
16771 These cases are OK. */
16772 previous_instantiation_extern_p = CLASSTYPE_INTERFACE_ONLY (t);
16774 if (!previous_instantiation_extern_p && !extern_p
16775 && (complain & tf_error))
16776 permerror (input_location, "duplicate explicit instantiation of %q#T", t);
16778 /* If we've already instantiated the template, just return now. */
16779 if (!CLASSTYPE_INTERFACE_ONLY (t))
16783 check_explicit_instantiation_namespace (TYPE_NAME (t));
16784 mark_class_instantiated (t, extern_p);
16792 /* In contrast to implicit instantiation, where only the
16793 declarations, and not the definitions, of members are
16794 instantiated, we have here:
16798 The explicit instantiation of a class template specialization
16799 implies the instantiation of all of its members not
16800 previously explicitly specialized in the translation unit
16801 containing the explicit instantiation.
16803 Of course, we can't instantiate member template classes, since
16804 we don't have any arguments for them. Note that the standard
16805 is unclear on whether the instantiation of the members are
16806 *explicit* instantiations or not. However, the most natural
16807 interpretation is that it should be an explicit instantiation. */
16810 for (tmp = TYPE_METHODS (t); tmp; tmp = DECL_CHAIN (tmp))
16811 if (TREE_CODE (tmp) == FUNCTION_DECL
16812 && DECL_TEMPLATE_INSTANTIATION (tmp))
16813 instantiate_class_member (tmp, extern_p);
16815 for (tmp = TYPE_FIELDS (t); tmp; tmp = DECL_CHAIN (tmp))
16816 if (TREE_CODE (tmp) == VAR_DECL && DECL_TEMPLATE_INSTANTIATION (tmp))
16817 instantiate_class_member (tmp, extern_p);
16819 if (CLASSTYPE_NESTED_UTDS (t))
16820 binding_table_foreach (CLASSTYPE_NESTED_UTDS (t),
16821 bt_instantiate_type_proc, &storage);
16825 /* Given a function DECL, which is a specialization of TMPL, modify
16826 DECL to be a re-instantiation of TMPL with the same template
16827 arguments. TMPL should be the template into which tsubst'ing
16828 should occur for DECL, not the most general template.
16830 One reason for doing this is a scenario like this:
16833 void f(const T&, int i);
16835 void g() { f(3, 7); }
16838 void f(const T& t, const int i) { }
16840 Note that when the template is first instantiated, with
16841 instantiate_template, the resulting DECL will have no name for the
16842 first parameter, and the wrong type for the second. So, when we go
16843 to instantiate the DECL, we regenerate it. */
16846 regenerate_decl_from_template (tree decl, tree tmpl)
16848 /* The arguments used to instantiate DECL, from the most general
16853 args = DECL_TI_ARGS (decl);
16854 code_pattern = DECL_TEMPLATE_RESULT (tmpl);
16856 /* Make sure that we can see identifiers, and compute access
16858 push_access_scope (decl);
16860 if (TREE_CODE (decl) == FUNCTION_DECL)
16868 args_depth = TMPL_ARGS_DEPTH (args);
16869 parms_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
16870 if (args_depth > parms_depth)
16871 args = get_innermost_template_args (args, parms_depth);
16873 specs = tsubst_exception_specification (TREE_TYPE (code_pattern),
16874 args, tf_error, NULL_TREE);
16876 TREE_TYPE (decl) = build_exception_variant (TREE_TYPE (decl),
16879 /* Merge parameter declarations. */
16880 decl_parm = skip_artificial_parms_for (decl,
16881 DECL_ARGUMENTS (decl));
16883 = skip_artificial_parms_for (code_pattern,
16884 DECL_ARGUMENTS (code_pattern));
16885 while (decl_parm && !FUNCTION_PARAMETER_PACK_P (pattern_parm))
16890 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
16891 DECL_NAME (decl_parm) = DECL_NAME (pattern_parm);
16892 parm_type = tsubst (TREE_TYPE (pattern_parm), args, tf_error,
16894 parm_type = type_decays_to (parm_type);
16895 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
16896 TREE_TYPE (decl_parm) = parm_type;
16897 attributes = DECL_ATTRIBUTES (pattern_parm);
16898 if (DECL_ATTRIBUTES (decl_parm) != attributes)
16900 DECL_ATTRIBUTES (decl_parm) = attributes;
16901 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
16903 decl_parm = DECL_CHAIN (decl_parm);
16904 pattern_parm = DECL_CHAIN (pattern_parm);
16906 /* Merge any parameters that match with the function parameter
16908 if (pattern_parm && FUNCTION_PARAMETER_PACK_P (pattern_parm))
16911 tree expanded_types;
16912 /* Expand the TYPE_PACK_EXPANSION that provides the types for
16913 the parameters in this function parameter pack. */
16914 expanded_types = tsubst_pack_expansion (TREE_TYPE (pattern_parm),
16915 args, tf_error, NULL_TREE);
16916 len = TREE_VEC_LENGTH (expanded_types);
16917 for (i = 0; i < len; i++)
16922 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
16923 /* Rename the parameter to include the index. */
16924 DECL_NAME (decl_parm) =
16925 make_ith_pack_parameter_name (DECL_NAME (pattern_parm), i);
16926 parm_type = TREE_VEC_ELT (expanded_types, i);
16927 parm_type = type_decays_to (parm_type);
16928 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
16929 TREE_TYPE (decl_parm) = parm_type;
16930 attributes = DECL_ATTRIBUTES (pattern_parm);
16931 if (DECL_ATTRIBUTES (decl_parm) != attributes)
16933 DECL_ATTRIBUTES (decl_parm) = attributes;
16934 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
16936 decl_parm = DECL_CHAIN (decl_parm);
16939 /* Merge additional specifiers from the CODE_PATTERN. */
16940 if (DECL_DECLARED_INLINE_P (code_pattern)
16941 && !DECL_DECLARED_INLINE_P (decl))
16942 DECL_DECLARED_INLINE_P (decl) = 1;
16944 else if (TREE_CODE (decl) == VAR_DECL)
16946 DECL_INITIAL (decl) =
16947 tsubst_expr (DECL_INITIAL (code_pattern), args,
16948 tf_error, DECL_TI_TEMPLATE (decl),
16949 /*integral_constant_expression_p=*/false);
16950 if (VAR_HAD_UNKNOWN_BOUND (decl))
16951 TREE_TYPE (decl) = tsubst (TREE_TYPE (code_pattern), args,
16952 tf_error, DECL_TI_TEMPLATE (decl));
16955 gcc_unreachable ();
16957 pop_access_scope (decl);
16960 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
16961 substituted to get DECL. */
16964 template_for_substitution (tree decl)
16966 tree tmpl = DECL_TI_TEMPLATE (decl);
16968 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
16969 for the instantiation. This is not always the most general
16970 template. Consider, for example:
16973 struct S { template <class U> void f();
16974 template <> void f<int>(); };
16976 and an instantiation of S<double>::f<int>. We want TD to be the
16977 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
16978 while (/* An instantiation cannot have a definition, so we need a
16979 more general template. */
16980 DECL_TEMPLATE_INSTANTIATION (tmpl)
16981 /* We must also deal with friend templates. Given:
16983 template <class T> struct S {
16984 template <class U> friend void f() {};
16987 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
16988 so far as the language is concerned, but that's still
16989 where we get the pattern for the instantiation from. On
16990 other hand, if the definition comes outside the class, say:
16992 template <class T> struct S {
16993 template <class U> friend void f();
16995 template <class U> friend void f() {}
16997 we don't need to look any further. That's what the check for
16998 DECL_INITIAL is for. */
16999 || (TREE_CODE (decl) == FUNCTION_DECL
17000 && DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION (tmpl)
17001 && !DECL_INITIAL (DECL_TEMPLATE_RESULT (tmpl))))
17003 /* The present template, TD, should not be a definition. If it
17004 were a definition, we should be using it! Note that we
17005 cannot restructure the loop to just keep going until we find
17006 a template with a definition, since that might go too far if
17007 a specialization was declared, but not defined. */
17008 gcc_assert (TREE_CODE (decl) != VAR_DECL
17009 || DECL_IN_AGGR_P (DECL_TEMPLATE_RESULT (tmpl)));
17011 /* Fetch the more general template. */
17012 tmpl = DECL_TI_TEMPLATE (tmpl);
17018 /* Returns true if we need to instantiate this template instance even if we
17019 know we aren't going to emit it.. */
17022 always_instantiate_p (tree decl)
17024 /* We always instantiate inline functions so that we can inline them. An
17025 explicit instantiation declaration prohibits implicit instantiation of
17026 non-inline functions. With high levels of optimization, we would
17027 normally inline non-inline functions -- but we're not allowed to do
17028 that for "extern template" functions. Therefore, we check
17029 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
17030 return ((TREE_CODE (decl) == FUNCTION_DECL
17031 && DECL_DECLARED_INLINE_P (decl))
17032 /* And we need to instantiate static data members so that
17033 their initializers are available in integral constant
17035 || (TREE_CODE (decl) == VAR_DECL
17036 && decl_maybe_constant_var_p (decl)));
17039 /* Produce the definition of D, a _DECL generated from a template. If
17040 DEFER_OK is nonzero, then we don't have to actually do the
17041 instantiation now; we just have to do it sometime. Normally it is
17042 an error if this is an explicit instantiation but D is undefined.
17043 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
17044 explicitly instantiated class template. */
17047 instantiate_decl (tree d, int defer_ok,
17048 bool expl_inst_class_mem_p)
17050 tree tmpl = DECL_TI_TEMPLATE (d);
17057 bool pattern_defined;
17059 location_t saved_loc = input_location;
17062 /* This function should only be used to instantiate templates for
17063 functions and static member variables. */
17064 gcc_assert (TREE_CODE (d) == FUNCTION_DECL
17065 || TREE_CODE (d) == VAR_DECL);
17067 /* Variables are never deferred; if instantiation is required, they
17068 are instantiated right away. That allows for better code in the
17069 case that an expression refers to the value of the variable --
17070 if the variable has a constant value the referring expression can
17071 take advantage of that fact. */
17072 if (TREE_CODE (d) == VAR_DECL
17073 || DECL_DECLARED_CONSTEXPR_P (d))
17076 /* Don't instantiate cloned functions. Instead, instantiate the
17077 functions they cloned. */
17078 if (TREE_CODE (d) == FUNCTION_DECL && DECL_CLONED_FUNCTION_P (d))
17079 d = DECL_CLONED_FUNCTION (d);
17081 if (DECL_TEMPLATE_INSTANTIATED (d)
17082 || DECL_TEMPLATE_SPECIALIZATION (d))
17083 /* D has already been instantiated or explicitly specialized, so
17084 there's nothing for us to do here.
17086 It might seem reasonable to check whether or not D is an explicit
17087 instantiation, and, if so, stop here. But when an explicit
17088 instantiation is deferred until the end of the compilation,
17089 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
17090 the instantiation. */
17093 /* Check to see whether we know that this template will be
17094 instantiated in some other file, as with "extern template"
17096 external_p = (DECL_INTERFACE_KNOWN (d) && DECL_REALLY_EXTERN (d));
17098 /* In general, we do not instantiate such templates. */
17099 if (external_p && !always_instantiate_p (d))
17102 gen_tmpl = most_general_template (tmpl);
17103 gen_args = DECL_TI_ARGS (d);
17105 if (tmpl != gen_tmpl)
17106 /* We should already have the extra args. */
17107 gcc_assert (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (gen_tmpl))
17108 == TMPL_ARGS_DEPTH (gen_args));
17109 /* And what's in the hash table should match D. */
17110 gcc_assert ((spec = retrieve_specialization (gen_tmpl, gen_args, 0)) == d
17111 || spec == NULL_TREE);
17113 /* This needs to happen before any tsubsting. */
17114 if (! push_tinst_level (d))
17117 timevar_push (TV_PARSE);
17119 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
17120 for the instantiation. */
17121 td = template_for_substitution (d);
17122 code_pattern = DECL_TEMPLATE_RESULT (td);
17124 /* We should never be trying to instantiate a member of a class
17125 template or partial specialization. */
17126 gcc_assert (d != code_pattern);
17128 if ((DECL_NAMESPACE_SCOPE_P (d) && !DECL_INITIALIZED_IN_CLASS_P (d))
17129 || DECL_TEMPLATE_SPECIALIZATION (td))
17130 /* In the case of a friend template whose definition is provided
17131 outside the class, we may have too many arguments. Drop the
17132 ones we don't need. The same is true for specializations. */
17133 args = get_innermost_template_args
17134 (gen_args, TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (td)));
17138 if (TREE_CODE (d) == FUNCTION_DECL)
17139 pattern_defined = (DECL_SAVED_TREE (code_pattern) != NULL_TREE);
17141 pattern_defined = ! DECL_IN_AGGR_P (code_pattern);
17143 /* We may be in the middle of deferred access check. Disable it now. */
17144 push_deferring_access_checks (dk_no_deferred);
17146 /* Unless an explicit instantiation directive has already determined
17147 the linkage of D, remember that a definition is available for
17149 if (pattern_defined
17150 && !DECL_INTERFACE_KNOWN (d)
17151 && !DECL_NOT_REALLY_EXTERN (d))
17152 mark_definable (d);
17154 DECL_SOURCE_LOCATION (td) = DECL_SOURCE_LOCATION (code_pattern);
17155 DECL_SOURCE_LOCATION (d) = DECL_SOURCE_LOCATION (code_pattern);
17156 input_location = DECL_SOURCE_LOCATION (d);
17158 /* If D is a member of an explicitly instantiated class template,
17159 and no definition is available, treat it like an implicit
17161 if (!pattern_defined && expl_inst_class_mem_p
17162 && DECL_EXPLICIT_INSTANTIATION (d))
17164 DECL_NOT_REALLY_EXTERN (d) = 0;
17165 DECL_INTERFACE_KNOWN (d) = 0;
17166 SET_DECL_IMPLICIT_INSTANTIATION (d);
17169 /* Recheck the substitutions to obtain any warning messages
17170 about ignoring cv qualifiers. Don't do this for artificial decls,
17171 as it breaks the context-sensitive substitution for lambda op(). */
17172 if (!defer_ok && !DECL_ARTIFICIAL (d))
17174 tree gen = DECL_TEMPLATE_RESULT (gen_tmpl);
17175 tree type = TREE_TYPE (gen);
17177 /* Make sure that we can see identifiers, and compute access
17178 correctly. D is already the target FUNCTION_DECL with the
17180 push_access_scope (d);
17182 if (TREE_CODE (gen) == FUNCTION_DECL)
17184 tsubst (DECL_ARGUMENTS (gen), gen_args, tf_warning_or_error, d);
17185 tsubst_exception_specification (type, gen_args, tf_warning_or_error,
17187 /* Don't simply tsubst the function type, as that will give
17188 duplicate warnings about poor parameter qualifications.
17189 The function arguments are the same as the decl_arguments
17190 without the top level cv qualifiers. */
17191 type = TREE_TYPE (type);
17193 tsubst (type, gen_args, tf_warning_or_error, d);
17195 pop_access_scope (d);
17198 /* Defer all other templates, unless we have been explicitly
17199 forbidden from doing so. */
17200 if (/* If there is no definition, we cannot instantiate the
17203 /* If it's OK to postpone instantiation, do so. */
17205 /* If this is a static data member that will be defined
17206 elsewhere, we don't want to instantiate the entire data
17207 member, but we do want to instantiate the initializer so that
17208 we can substitute that elsewhere. */
17209 || (external_p && TREE_CODE (d) == VAR_DECL))
17211 /* The definition of the static data member is now required so
17212 we must substitute the initializer. */
17213 if (TREE_CODE (d) == VAR_DECL
17214 && !DECL_INITIAL (d)
17215 && DECL_INITIAL (code_pattern))
17219 bool const_init = false;
17221 ns = decl_namespace_context (d);
17222 push_nested_namespace (ns);
17223 push_nested_class (DECL_CONTEXT (d));
17224 init = tsubst_expr (DECL_INITIAL (code_pattern),
17226 tf_warning_or_error, NULL_TREE,
17227 /*integral_constant_expression_p=*/false);
17228 /* Make sure the initializer is still constant, in case of
17229 circular dependency (template/instantiate6.C). */
17231 = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (code_pattern);
17232 cp_finish_decl (d, init, /*init_const_expr_p=*/const_init,
17233 /*asmspec_tree=*/NULL_TREE,
17234 LOOKUP_ONLYCONVERTING);
17235 pop_nested_class ();
17236 pop_nested_namespace (ns);
17239 /* We restore the source position here because it's used by
17240 add_pending_template. */
17241 input_location = saved_loc;
17243 if (at_eof && !pattern_defined
17244 && DECL_EXPLICIT_INSTANTIATION (d)
17245 && DECL_NOT_REALLY_EXTERN (d))
17248 The definition of a non-exported function template, a
17249 non-exported member function template, or a non-exported
17250 member function or static data member of a class template
17251 shall be present in every translation unit in which it is
17252 explicitly instantiated. */
17253 permerror (input_location, "explicit instantiation of %qD "
17254 "but no definition available", d);
17256 /* If we're in unevaluated context, we just wanted to get the
17257 constant value; this isn't an odr use, so don't queue
17258 a full instantiation. */
17259 if (cp_unevaluated_operand != 0)
17261 /* ??? Historically, we have instantiated inline functions, even
17262 when marked as "extern template". */
17263 if (!(external_p && TREE_CODE (d) == VAR_DECL))
17264 add_pending_template (d);
17267 /* Tell the repository that D is available in this translation unit
17268 -- and see if it is supposed to be instantiated here. */
17269 if (TREE_PUBLIC (d) && !DECL_REALLY_EXTERN (d) && !repo_emit_p (d))
17271 /* In a PCH file, despite the fact that the repository hasn't
17272 requested instantiation in the PCH it is still possible that
17273 an instantiation will be required in a file that includes the
17276 add_pending_template (d);
17277 /* Instantiate inline functions so that the inliner can do its
17278 job, even though we'll not be emitting a copy of this
17280 if (!(TREE_CODE (d) == FUNCTION_DECL && possibly_inlined_p (d)))
17284 need_push = !cfun || !global_bindings_p ();
17286 push_to_top_level ();
17288 /* Mark D as instantiated so that recursive calls to
17289 instantiate_decl do not try to instantiate it again. */
17290 DECL_TEMPLATE_INSTANTIATED (d) = 1;
17292 /* Regenerate the declaration in case the template has been modified
17293 by a subsequent redeclaration. */
17294 regenerate_decl_from_template (d, td);
17296 /* We already set the file and line above. Reset them now in case
17297 they changed as a result of calling regenerate_decl_from_template. */
17298 input_location = DECL_SOURCE_LOCATION (d);
17300 if (TREE_CODE (d) == VAR_DECL)
17303 bool const_init = false;
17305 /* Clear out DECL_RTL; whatever was there before may not be right
17306 since we've reset the type of the declaration. */
17307 SET_DECL_RTL (d, NULL);
17308 DECL_IN_AGGR_P (d) = 0;
17310 /* The initializer is placed in DECL_INITIAL by
17311 regenerate_decl_from_template so we don't need to
17312 push/pop_access_scope again here. Pull it out so that
17313 cp_finish_decl can process it. */
17314 init = DECL_INITIAL (d);
17315 DECL_INITIAL (d) = NULL_TREE;
17316 DECL_INITIALIZED_P (d) = 0;
17318 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
17319 initializer. That function will defer actual emission until
17320 we have a chance to determine linkage. */
17321 DECL_EXTERNAL (d) = 0;
17323 /* Enter the scope of D so that access-checking works correctly. */
17324 push_nested_class (DECL_CONTEXT (d));
17325 const_init = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (code_pattern);
17326 cp_finish_decl (d, init, const_init, NULL_TREE, 0);
17327 pop_nested_class ();
17329 else if (TREE_CODE (d) == FUNCTION_DECL)
17331 htab_t saved_local_specializations;
17336 /* Save away the current list, in case we are instantiating one
17337 template from within the body of another. */
17338 saved_local_specializations = local_specializations;
17340 /* Set up the list of local specializations. */
17341 local_specializations = htab_create (37,
17342 hash_local_specialization,
17343 eq_local_specializations,
17346 /* Set up context. */
17347 start_preparsed_function (d, NULL_TREE, SF_PRE_PARSED);
17349 /* Create substitution entries for the parameters. */
17350 subst_decl = DECL_TEMPLATE_RESULT (template_for_substitution (d));
17351 tmpl_parm = DECL_ARGUMENTS (subst_decl);
17352 spec_parm = DECL_ARGUMENTS (d);
17353 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (d))
17355 register_local_specialization (spec_parm, tmpl_parm);
17356 spec_parm = skip_artificial_parms_for (d, spec_parm);
17357 tmpl_parm = skip_artificial_parms_for (subst_decl, tmpl_parm);
17359 while (tmpl_parm && !FUNCTION_PARAMETER_PACK_P (tmpl_parm))
17361 register_local_specialization (spec_parm, tmpl_parm);
17362 tmpl_parm = DECL_CHAIN (tmpl_parm);
17363 spec_parm = DECL_CHAIN (spec_parm);
17365 if (tmpl_parm && FUNCTION_PARAMETER_PACK_P (tmpl_parm))
17367 /* Register the (value) argument pack as a specialization of
17368 TMPL_PARM, then move on. */
17369 tree argpack = make_fnparm_pack (spec_parm);
17370 register_local_specialization (argpack, tmpl_parm);
17371 tmpl_parm = DECL_CHAIN (tmpl_parm);
17372 spec_parm = NULL_TREE;
17374 gcc_assert (!spec_parm);
17376 /* Substitute into the body of the function. */
17377 tsubst_expr (DECL_SAVED_TREE (code_pattern), args,
17378 tf_warning_or_error, tmpl,
17379 /*integral_constant_expression_p=*/false);
17381 /* Set the current input_location to the end of the function
17382 so that finish_function knows where we are. */
17383 input_location = DECL_STRUCT_FUNCTION (code_pattern)->function_end_locus;
17385 /* We don't need the local specializations any more. */
17386 htab_delete (local_specializations);
17387 local_specializations = saved_local_specializations;
17389 /* Finish the function. */
17390 d = finish_function (0);
17391 expand_or_defer_fn (d);
17394 /* We're not deferring instantiation any more. */
17395 TI_PENDING_TEMPLATE_FLAG (DECL_TEMPLATE_INFO (d)) = 0;
17398 pop_from_top_level ();
17401 input_location = saved_loc;
17402 pop_deferring_access_checks ();
17403 pop_tinst_level ();
17405 timevar_pop (TV_PARSE);
17410 /* Run through the list of templates that we wish we could
17411 instantiate, and instantiate any we can. RETRIES is the
17412 number of times we retry pending template instantiation. */
17415 instantiate_pending_templates (int retries)
17418 location_t saved_loc = input_location;
17420 /* Instantiating templates may trigger vtable generation. This in turn
17421 may require further template instantiations. We place a limit here
17422 to avoid infinite loop. */
17423 if (pending_templates && retries >= max_tinst_depth)
17425 tree decl = pending_templates->tinst->decl;
17427 error ("template instantiation depth exceeds maximum of %d"
17428 " instantiating %q+D, possibly from virtual table generation"
17429 " (use -ftemplate-depth= to increase the maximum)",
17430 max_tinst_depth, decl);
17431 if (TREE_CODE (decl) == FUNCTION_DECL)
17432 /* Pretend that we defined it. */
17433 DECL_INITIAL (decl) = error_mark_node;
17439 struct pending_template **t = &pending_templates;
17440 struct pending_template *last = NULL;
17444 tree instantiation = reopen_tinst_level ((*t)->tinst);
17445 bool complete = false;
17447 if (TYPE_P (instantiation))
17451 if (!COMPLETE_TYPE_P (instantiation))
17453 instantiate_class_template (instantiation);
17454 if (CLASSTYPE_TEMPLATE_INSTANTIATION (instantiation))
17455 for (fn = TYPE_METHODS (instantiation);
17457 fn = TREE_CHAIN (fn))
17458 if (! DECL_ARTIFICIAL (fn))
17459 instantiate_decl (fn,
17461 /*expl_inst_class_mem_p=*/false);
17462 if (COMPLETE_TYPE_P (instantiation))
17466 complete = COMPLETE_TYPE_P (instantiation);
17470 if (!DECL_TEMPLATE_SPECIALIZATION (instantiation)
17471 && !DECL_TEMPLATE_INSTANTIATED (instantiation))
17474 = instantiate_decl (instantiation,
17476 /*expl_inst_class_mem_p=*/false);
17477 if (DECL_TEMPLATE_INSTANTIATED (instantiation))
17481 complete = (DECL_TEMPLATE_SPECIALIZATION (instantiation)
17482 || DECL_TEMPLATE_INSTANTIATED (instantiation));
17486 /* If INSTANTIATION has been instantiated, then we don't
17487 need to consider it again in the future. */
17495 current_tinst_level = NULL;
17497 last_pending_template = last;
17499 while (reconsider);
17501 input_location = saved_loc;
17504 /* Substitute ARGVEC into T, which is a list of initializers for
17505 either base class or a non-static data member. The TREE_PURPOSEs
17506 are DECLs, and the TREE_VALUEs are the initializer values. Used by
17507 instantiate_decl. */
17510 tsubst_initializer_list (tree t, tree argvec)
17512 tree inits = NULL_TREE;
17514 for (; t; t = TREE_CHAIN (t))
17518 tree expanded_bases = NULL_TREE;
17519 tree expanded_arguments = NULL_TREE;
17522 if (TREE_CODE (TREE_PURPOSE (t)) == TYPE_PACK_EXPANSION)
17527 /* Expand the base class expansion type into separate base
17529 expanded_bases = tsubst_pack_expansion (TREE_PURPOSE (t), argvec,
17530 tf_warning_or_error,
17532 if (expanded_bases == error_mark_node)
17535 /* We'll be building separate TREE_LISTs of arguments for
17537 len = TREE_VEC_LENGTH (expanded_bases);
17538 expanded_arguments = make_tree_vec (len);
17539 for (i = 0; i < len; i++)
17540 TREE_VEC_ELT (expanded_arguments, i) = NULL_TREE;
17542 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
17543 expand each argument in the TREE_VALUE of t. */
17544 expr = make_node (EXPR_PACK_EXPANSION);
17545 PACK_EXPANSION_PARAMETER_PACKS (expr) =
17546 PACK_EXPANSION_PARAMETER_PACKS (TREE_PURPOSE (t));
17548 if (TREE_VALUE (t) == void_type_node)
17549 /* VOID_TYPE_NODE is used to indicate
17550 value-initialization. */
17552 for (i = 0; i < len; i++)
17553 TREE_VEC_ELT (expanded_arguments, i) = void_type_node;
17557 /* Substitute parameter packs into each argument in the
17559 in_base_initializer = 1;
17560 for (arg = TREE_VALUE (t); arg; arg = TREE_CHAIN (arg))
17562 tree expanded_exprs;
17564 /* Expand the argument. */
17565 SET_PACK_EXPANSION_PATTERN (expr, TREE_VALUE (arg));
17567 = tsubst_pack_expansion (expr, argvec,
17568 tf_warning_or_error,
17570 if (expanded_exprs == error_mark_node)
17573 /* Prepend each of the expanded expressions to the
17574 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
17575 for (i = 0; i < len; i++)
17577 TREE_VEC_ELT (expanded_arguments, i) =
17578 tree_cons (NULL_TREE,
17579 TREE_VEC_ELT (expanded_exprs, i),
17580 TREE_VEC_ELT (expanded_arguments, i));
17583 in_base_initializer = 0;
17585 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
17586 since we built them backwards. */
17587 for (i = 0; i < len; i++)
17589 TREE_VEC_ELT (expanded_arguments, i) =
17590 nreverse (TREE_VEC_ELT (expanded_arguments, i));
17595 for (i = 0; i < len; ++i)
17597 if (expanded_bases)
17599 decl = TREE_VEC_ELT (expanded_bases, i);
17600 decl = expand_member_init (decl);
17601 init = TREE_VEC_ELT (expanded_arguments, i);
17605 decl = tsubst_copy (TREE_PURPOSE (t), argvec,
17606 tf_warning_or_error, NULL_TREE);
17608 decl = expand_member_init (decl);
17609 if (decl && !DECL_P (decl))
17610 in_base_initializer = 1;
17612 init = TREE_VALUE (t);
17613 if (init != void_type_node)
17614 init = tsubst_expr (init, argvec,
17615 tf_warning_or_error, NULL_TREE,
17616 /*integral_constant_expression_p=*/false);
17617 in_base_initializer = 0;
17622 init = build_tree_list (decl, init);
17623 TREE_CHAIN (init) = inits;
17631 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
17634 set_current_access_from_decl (tree decl)
17636 if (TREE_PRIVATE (decl))
17637 current_access_specifier = access_private_node;
17638 else if (TREE_PROTECTED (decl))
17639 current_access_specifier = access_protected_node;
17641 current_access_specifier = access_public_node;
17644 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
17645 is the instantiation (which should have been created with
17646 start_enum) and ARGS are the template arguments to use. */
17649 tsubst_enum (tree tag, tree newtag, tree args)
17653 if (SCOPED_ENUM_P (newtag))
17654 begin_scope (sk_scoped_enum, newtag);
17656 for (e = TYPE_VALUES (tag); e; e = TREE_CHAIN (e))
17661 decl = TREE_VALUE (e);
17662 /* Note that in a template enum, the TREE_VALUE is the
17663 CONST_DECL, not the corresponding INTEGER_CST. */
17664 value = tsubst_expr (DECL_INITIAL (decl),
17665 args, tf_warning_or_error, NULL_TREE,
17666 /*integral_constant_expression_p=*/true);
17668 /* Give this enumeration constant the correct access. */
17669 set_current_access_from_decl (decl);
17671 /* Actually build the enumerator itself. */
17673 (DECL_NAME (decl), value, newtag, DECL_SOURCE_LOCATION (decl));
17676 if (SCOPED_ENUM_P (newtag))
17679 finish_enum_value_list (newtag);
17680 finish_enum (newtag);
17682 DECL_SOURCE_LOCATION (TYPE_NAME (newtag))
17683 = DECL_SOURCE_LOCATION (TYPE_NAME (tag));
17686 /* DECL is a FUNCTION_DECL that is a template specialization. Return
17687 its type -- but without substituting the innermost set of template
17688 arguments. So, innermost set of template parameters will appear in
17692 get_mostly_instantiated_function_type (tree decl)
17700 tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
17701 targs = DECL_TI_ARGS (decl);
17702 tparms = DECL_TEMPLATE_PARMS (tmpl);
17703 parm_depth = TMPL_PARMS_DEPTH (tparms);
17705 /* There should be as many levels of arguments as there are levels
17707 gcc_assert (parm_depth == TMPL_ARGS_DEPTH (targs));
17709 fn_type = TREE_TYPE (tmpl);
17711 if (parm_depth == 1)
17712 /* No substitution is necessary. */
17716 int i, save_access_control;
17719 /* Replace the innermost level of the TARGS with NULL_TREEs to
17720 let tsubst know not to substitute for those parameters. */
17721 partial_args = make_tree_vec (TREE_VEC_LENGTH (targs));
17722 for (i = 1; i < TMPL_ARGS_DEPTH (targs); ++i)
17723 SET_TMPL_ARGS_LEVEL (partial_args, i,
17724 TMPL_ARGS_LEVEL (targs, i));
17725 SET_TMPL_ARGS_LEVEL (partial_args,
17726 TMPL_ARGS_DEPTH (targs),
17727 make_tree_vec (DECL_NTPARMS (tmpl)));
17729 /* Disable access control as this function is used only during
17731 save_access_control = flag_access_control;
17732 flag_access_control = 0;
17734 ++processing_template_decl;
17735 /* Now, do the (partial) substitution to figure out the
17736 appropriate function type. */
17737 fn_type = tsubst (fn_type, partial_args, tf_error, NULL_TREE);
17738 --processing_template_decl;
17740 /* Substitute into the template parameters to obtain the real
17741 innermost set of parameters. This step is important if the
17742 innermost set of template parameters contains value
17743 parameters whose types depend on outer template parameters. */
17744 TREE_VEC_LENGTH (partial_args)--;
17745 tparms = tsubst_template_parms (tparms, partial_args, tf_error);
17747 flag_access_control = save_access_control;
17753 /* Return truthvalue if we're processing a template different from
17754 the last one involved in diagnostics. */
17756 problematic_instantiation_changed (void)
17758 return last_template_error_tick != tinst_level_tick;
17761 /* Remember current template involved in diagnostics. */
17763 record_last_problematic_instantiation (void)
17765 last_template_error_tick = tinst_level_tick;
17768 struct tinst_level *
17769 current_instantiation (void)
17771 return current_tinst_level;
17774 /* [temp.param] Check that template non-type parm TYPE is of an allowable
17775 type. Return zero for ok, nonzero for disallowed. Issue error and
17776 warning messages under control of COMPLAIN. */
17779 invalid_nontype_parm_type_p (tree type, tsubst_flags_t complain)
17781 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
17783 else if (POINTER_TYPE_P (type))
17785 else if (TYPE_PTR_TO_MEMBER_P (type))
17787 else if (TREE_CODE (type) == TEMPLATE_TYPE_PARM)
17789 else if (TREE_CODE (type) == TYPENAME_TYPE)
17792 if (complain & tf_error)
17793 error ("%q#T is not a valid type for a template constant parameter", type);
17797 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
17798 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
17801 dependent_type_p_r (tree type)
17807 A type is dependent if it is:
17809 -- a template parameter. Template template parameters are types
17810 for us (since TYPE_P holds true for them) so we handle
17812 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
17813 || TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM)
17815 /* -- a qualified-id with a nested-name-specifier which contains a
17816 class-name that names a dependent type or whose unqualified-id
17817 names a dependent type. */
17818 if (TREE_CODE (type) == TYPENAME_TYPE)
17820 /* -- a cv-qualified type where the cv-unqualified type is
17822 type = TYPE_MAIN_VARIANT (type);
17823 /* -- a compound type constructed from any dependent type. */
17824 if (TYPE_PTR_TO_MEMBER_P (type))
17825 return (dependent_type_p (TYPE_PTRMEM_CLASS_TYPE (type))
17826 || dependent_type_p (TYPE_PTRMEM_POINTED_TO_TYPE
17828 else if (TREE_CODE (type) == POINTER_TYPE
17829 || TREE_CODE (type) == REFERENCE_TYPE)
17830 return dependent_type_p (TREE_TYPE (type));
17831 else if (TREE_CODE (type) == FUNCTION_TYPE
17832 || TREE_CODE (type) == METHOD_TYPE)
17836 if (dependent_type_p (TREE_TYPE (type)))
17838 for (arg_type = TYPE_ARG_TYPES (type);
17840 arg_type = TREE_CHAIN (arg_type))
17841 if (dependent_type_p (TREE_VALUE (arg_type)))
17845 /* -- an array type constructed from any dependent type or whose
17846 size is specified by a constant expression that is
17849 We checked for type- and value-dependence of the bounds in
17850 compute_array_index_type, so TYPE_DEPENDENT_P is already set. */
17851 if (TREE_CODE (type) == ARRAY_TYPE)
17853 if (TYPE_DOMAIN (type)
17854 && dependent_type_p (TYPE_DOMAIN (type)))
17856 return dependent_type_p (TREE_TYPE (type));
17859 /* -- a template-id in which either the template name is a template
17861 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
17863 /* ... or any of the template arguments is a dependent type or
17864 an expression that is type-dependent or value-dependent. */
17865 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INFO (type)
17866 && (any_dependent_template_arguments_p
17867 (INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type)))))
17870 /* All TYPEOF_TYPEs and DECLTYPE_TYPEs are dependent; if the
17871 argument of the `typeof' expression is not type-dependent, then
17872 it should already been have resolved. */
17873 if (TREE_CODE (type) == TYPEOF_TYPE
17874 || TREE_CODE (type) == DECLTYPE_TYPE)
17877 /* A template argument pack is dependent if any of its packed
17879 if (TREE_CODE (type) == TYPE_ARGUMENT_PACK)
17881 tree args = ARGUMENT_PACK_ARGS (type);
17882 int i, len = TREE_VEC_LENGTH (args);
17883 for (i = 0; i < len; ++i)
17884 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
17888 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
17889 be template parameters. */
17890 if (TREE_CODE (type) == TYPE_PACK_EXPANSION)
17893 /* The standard does not specifically mention types that are local
17894 to template functions or local classes, but they should be
17895 considered dependent too. For example:
17897 template <int I> void f() {
17902 The size of `E' cannot be known until the value of `I' has been
17903 determined. Therefore, `E' must be considered dependent. */
17904 scope = TYPE_CONTEXT (type);
17905 if (scope && TYPE_P (scope))
17906 return dependent_type_p (scope);
17907 else if (scope && TREE_CODE (scope) == FUNCTION_DECL)
17908 return type_dependent_expression_p (scope);
17910 /* Other types are non-dependent. */
17914 /* Returns TRUE if TYPE is dependent, in the sense of
17915 [temp.dep.type]. */
17918 dependent_type_p (tree type)
17920 /* If there are no template parameters in scope, then there can't be
17921 any dependent types. */
17922 if (!processing_template_decl)
17924 /* If we are not processing a template, then nobody should be
17925 providing us with a dependent type. */
17927 gcc_assert (TREE_CODE (type) != TEMPLATE_TYPE_PARM || is_auto (type));
17931 /* If the type is NULL, we have not computed a type for the entity
17932 in question; in that case, the type is dependent. */
17936 /* Erroneous types can be considered non-dependent. */
17937 if (type == error_mark_node)
17940 /* If we have not already computed the appropriate value for TYPE,
17942 if (!TYPE_DEPENDENT_P_VALID (type))
17944 TYPE_DEPENDENT_P (type) = dependent_type_p_r (type);
17945 TYPE_DEPENDENT_P_VALID (type) = 1;
17948 return TYPE_DEPENDENT_P (type);
17951 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
17952 lookup. In other words, a dependent type that is not the current
17956 dependent_scope_p (tree scope)
17958 return (scope && TYPE_P (scope) && dependent_type_p (scope)
17959 && !currently_open_class (scope));
17962 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
17963 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
17966 /* Note that this predicate is not appropriate for general expressions;
17967 only constant expressions (that satisfy potential_constant_expression)
17968 can be tested for value dependence.
17970 We should really also have a predicate for "instantiation-dependent".
17972 fold_non_dependent_expr: fold if constant and not type-dependent and not value-dependent.
17973 (what about instantiation-dependent constant-expressions?)
17974 is_late_template_attribute: defer if instantiation-dependent.
17975 compute_array_index_type: proceed if constant and not t- or v-dependent
17976 if instantiation-dependent, need to remember full expression
17977 uses_template_parms: FIXME - need to audit callers
17978 tsubst_decl [function_decl]: Why is this using value_dependent_expression_p?
17979 dependent_type_p [array_type]: dependent if index type is dependent
17981 static_assert - instantiation-dependent */
17984 value_dependent_expression_p (tree expression)
17986 if (!processing_template_decl)
17989 /* A name declared with a dependent type. */
17990 if (DECL_P (expression) && type_dependent_expression_p (expression))
17993 switch (TREE_CODE (expression))
17995 case IDENTIFIER_NODE:
17996 /* A name that has not been looked up -- must be dependent. */
17999 case TEMPLATE_PARM_INDEX:
18000 /* A non-type template parm. */
18004 /* A non-type template parm. */
18005 if (DECL_TEMPLATE_PARM_P (expression))
18007 return value_dependent_expression_p (DECL_INITIAL (expression));
18010 /* A constant with integral or enumeration type and is initialized
18011 with an expression that is value-dependent. */
18012 if (DECL_INITIAL (expression)
18013 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (expression))
18014 && value_dependent_expression_p (DECL_INITIAL (expression)))
18018 case DYNAMIC_CAST_EXPR:
18019 case STATIC_CAST_EXPR:
18020 case CONST_CAST_EXPR:
18021 case REINTERPRET_CAST_EXPR:
18023 /* These expressions are value-dependent if the type to which
18024 the cast occurs is dependent or the expression being casted
18025 is value-dependent. */
18027 tree type = TREE_TYPE (expression);
18029 if (dependent_type_p (type))
18032 /* A functional cast has a list of operands. */
18033 expression = TREE_OPERAND (expression, 0);
18036 /* If there are no operands, it must be an expression such
18037 as "int()". This should not happen for aggregate types
18038 because it would form non-constant expressions. */
18039 gcc_assert (cxx_dialect >= cxx0x
18040 || INTEGRAL_OR_ENUMERATION_TYPE_P (type));
18045 if (TREE_CODE (expression) == TREE_LIST)
18046 return any_value_dependent_elements_p (expression);
18048 return value_dependent_expression_p (expression);
18053 /* A `sizeof' expression is value-dependent if the operand is
18054 type-dependent or is a pack expansion. */
18055 expression = TREE_OPERAND (expression, 0);
18056 if (PACK_EXPANSION_P (expression))
18058 else if (TYPE_P (expression))
18059 return dependent_type_p (expression);
18060 return type_dependent_expression_p (expression);
18062 case AT_ENCODE_EXPR:
18063 /* An 'encode' expression is value-dependent if the operand is
18065 expression = TREE_OPERAND (expression, 0);
18066 return dependent_type_p (expression);
18068 case NOEXCEPT_EXPR:
18069 expression = TREE_OPERAND (expression, 0);
18070 /* FIXME why check value-dependency? */
18071 return (type_dependent_expression_p (expression)
18072 || value_dependent_expression_p (expression));
18076 tree name = TREE_OPERAND (expression, 1);
18077 return value_dependent_expression_p (name);
18080 case COMPONENT_REF:
18081 return (value_dependent_expression_p (TREE_OPERAND (expression, 0))
18082 || value_dependent_expression_p (TREE_OPERAND (expression, 1)));
18084 case NONTYPE_ARGUMENT_PACK:
18085 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
18086 is value-dependent. */
18088 tree values = ARGUMENT_PACK_ARGS (expression);
18089 int i, len = TREE_VEC_LENGTH (values);
18091 for (i = 0; i < len; ++i)
18092 if (value_dependent_expression_p (TREE_VEC_ELT (values, i)))
18100 tree type2 = TRAIT_EXPR_TYPE2 (expression);
18101 return (dependent_type_p (TRAIT_EXPR_TYPE1 (expression))
18102 || (type2 ? dependent_type_p (type2) : false));
18106 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
18107 || (value_dependent_expression_p (TREE_OPERAND (expression, 2))));
18110 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
18111 || (value_dependent_expression_p (TREE_OPERAND (expression, 1))));
18115 tree op = TREE_OPERAND (expression, 0);
18116 return (value_dependent_expression_p (op)
18117 || has_value_dependent_address (op));
18122 tree fn = get_callee_fndecl (expression);
18124 if (!fn && value_dependent_expression_p (CALL_EXPR_FN (expression)))
18126 nargs = call_expr_nargs (expression);
18127 for (i = 0; i < nargs; ++i)
18129 tree op = CALL_EXPR_ARG (expression, i);
18130 /* In a call to a constexpr member function, look through the
18131 implicit ADDR_EXPR on the object argument so that it doesn't
18132 cause the call to be considered value-dependent. We also
18133 look through it in potential_constant_expression. */
18134 if (i == 0 && fn && DECL_DECLARED_CONSTEXPR_P (fn)
18135 && DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
18136 && TREE_CODE (op) == ADDR_EXPR)
18137 op = TREE_OPERAND (op, 0);
18138 if (value_dependent_expression_p (op))
18145 /* A constant expression is value-dependent if any subexpression is
18146 value-dependent. */
18147 switch (TREE_CODE_CLASS (TREE_CODE (expression)))
18149 case tcc_reference:
18151 return (value_dependent_expression_p
18152 (TREE_OPERAND (expression, 0)));
18154 case tcc_comparison:
18156 return ((value_dependent_expression_p
18157 (TREE_OPERAND (expression, 0)))
18158 || (value_dependent_expression_p
18159 (TREE_OPERAND (expression, 1))));
18161 case tcc_expression:
18165 for (i = 0; i < TREE_OPERAND_LENGTH (expression); ++i)
18166 /* In some cases, some of the operands may be missing.
18167 (For example, in the case of PREDECREMENT_EXPR, the
18168 amount to increment by may be missing.) That doesn't
18169 make the expression dependent. */
18170 if (TREE_OPERAND (expression, i)
18171 && (value_dependent_expression_p
18172 (TREE_OPERAND (expression, i))))
18182 /* The expression is not value-dependent. */
18186 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
18187 [temp.dep.expr]. */
18190 type_dependent_expression_p (tree expression)
18192 if (!processing_template_decl)
18195 if (expression == error_mark_node)
18198 /* An unresolved name is always dependent. */
18199 if (TREE_CODE (expression) == IDENTIFIER_NODE
18200 || TREE_CODE (expression) == USING_DECL)
18203 /* Some expression forms are never type-dependent. */
18204 if (TREE_CODE (expression) == PSEUDO_DTOR_EXPR
18205 || TREE_CODE (expression) == SIZEOF_EXPR
18206 || TREE_CODE (expression) == ALIGNOF_EXPR
18207 || TREE_CODE (expression) == AT_ENCODE_EXPR
18208 || TREE_CODE (expression) == NOEXCEPT_EXPR
18209 || TREE_CODE (expression) == TRAIT_EXPR
18210 || TREE_CODE (expression) == TYPEID_EXPR
18211 || TREE_CODE (expression) == DELETE_EXPR
18212 || TREE_CODE (expression) == VEC_DELETE_EXPR
18213 || TREE_CODE (expression) == THROW_EXPR)
18216 /* The types of these expressions depends only on the type to which
18217 the cast occurs. */
18218 if (TREE_CODE (expression) == DYNAMIC_CAST_EXPR
18219 || TREE_CODE (expression) == STATIC_CAST_EXPR
18220 || TREE_CODE (expression) == CONST_CAST_EXPR
18221 || TREE_CODE (expression) == REINTERPRET_CAST_EXPR
18222 || TREE_CODE (expression) == CAST_EXPR)
18223 return dependent_type_p (TREE_TYPE (expression));
18225 /* The types of these expressions depends only on the type created
18226 by the expression. */
18227 if (TREE_CODE (expression) == NEW_EXPR
18228 || TREE_CODE (expression) == VEC_NEW_EXPR)
18230 /* For NEW_EXPR tree nodes created inside a template, either
18231 the object type itself or a TREE_LIST may appear as the
18233 tree type = TREE_OPERAND (expression, 1);
18234 if (TREE_CODE (type) == TREE_LIST)
18235 /* This is an array type. We need to check array dimensions
18237 return dependent_type_p (TREE_VALUE (TREE_PURPOSE (type)))
18238 || value_dependent_expression_p
18239 (TREE_OPERAND (TREE_VALUE (type), 1));
18241 return dependent_type_p (type);
18244 if (TREE_CODE (expression) == SCOPE_REF)
18246 tree scope = TREE_OPERAND (expression, 0);
18247 tree name = TREE_OPERAND (expression, 1);
18249 /* 14.6.2.2 [temp.dep.expr]: An id-expression is type-dependent if it
18250 contains an identifier associated by name lookup with one or more
18251 declarations declared with a dependent type, or...a
18252 nested-name-specifier or qualified-id that names a member of an
18253 unknown specialization. */
18254 return (type_dependent_expression_p (name)
18255 || dependent_scope_p (scope));
18258 if (TREE_CODE (expression) == FUNCTION_DECL
18259 && DECL_LANG_SPECIFIC (expression)
18260 && DECL_TEMPLATE_INFO (expression)
18261 && (any_dependent_template_arguments_p
18262 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (expression)))))
18265 if (TREE_CODE (expression) == TEMPLATE_DECL
18266 && !DECL_TEMPLATE_TEMPLATE_PARM_P (expression))
18269 if (TREE_CODE (expression) == STMT_EXPR)
18270 expression = stmt_expr_value_expr (expression);
18272 if (BRACE_ENCLOSED_INITIALIZER_P (expression))
18277 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), i, elt)
18279 if (type_dependent_expression_p (elt))
18285 /* A static data member of the current instantiation with incomplete
18286 array type is type-dependent, as the definition and specializations
18287 can have different bounds. */
18288 if (TREE_CODE (expression) == VAR_DECL
18289 && DECL_CLASS_SCOPE_P (expression)
18290 && dependent_type_p (DECL_CONTEXT (expression))
18291 && VAR_HAD_UNKNOWN_BOUND (expression))
18294 if (TREE_TYPE (expression) == unknown_type_node)
18296 if (TREE_CODE (expression) == ADDR_EXPR)
18297 return type_dependent_expression_p (TREE_OPERAND (expression, 0));
18298 if (TREE_CODE (expression) == COMPONENT_REF
18299 || TREE_CODE (expression) == OFFSET_REF)
18301 if (type_dependent_expression_p (TREE_OPERAND (expression, 0)))
18303 expression = TREE_OPERAND (expression, 1);
18304 if (TREE_CODE (expression) == IDENTIFIER_NODE)
18307 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
18308 if (TREE_CODE (expression) == SCOPE_REF)
18311 if (TREE_CODE (expression) == BASELINK)
18312 expression = BASELINK_FUNCTIONS (expression);
18314 if (TREE_CODE (expression) == TEMPLATE_ID_EXPR)
18316 if (any_dependent_template_arguments_p
18317 (TREE_OPERAND (expression, 1)))
18319 expression = TREE_OPERAND (expression, 0);
18321 gcc_assert (TREE_CODE (expression) == OVERLOAD
18322 || TREE_CODE (expression) == FUNCTION_DECL);
18326 if (type_dependent_expression_p (OVL_CURRENT (expression)))
18328 expression = OVL_NEXT (expression);
18333 gcc_assert (TREE_CODE (expression) != TYPE_DECL);
18335 return (dependent_type_p (TREE_TYPE (expression)));
18338 /* Like type_dependent_expression_p, but it also works while not processing
18339 a template definition, i.e. during substitution or mangling. */
18342 type_dependent_expression_p_push (tree expr)
18345 ++processing_template_decl;
18346 b = type_dependent_expression_p (expr);
18347 --processing_template_decl;
18351 /* Returns TRUE if ARGS contains a type-dependent expression. */
18354 any_type_dependent_arguments_p (const VEC(tree,gc) *args)
18359 FOR_EACH_VEC_ELT (tree, args, i, arg)
18361 if (type_dependent_expression_p (arg))
18367 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
18368 expressions) contains any value-dependent expressions. */
18371 any_value_dependent_elements_p (const_tree list)
18373 for (; list; list = TREE_CHAIN (list))
18374 if (value_dependent_expression_p (TREE_VALUE (list)))
18380 /* Returns TRUE if the ARG (a template argument) is dependent. */
18383 dependent_template_arg_p (tree arg)
18385 if (!processing_template_decl)
18388 /* Assume a template argument that was wrongly written by the user
18389 is dependent. This is consistent with what
18390 any_dependent_template_arguments_p [that calls this function]
18392 if (arg == error_mark_node)
18395 if (TREE_CODE (arg) == TEMPLATE_DECL
18396 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
18397 return dependent_template_p (arg);
18398 else if (ARGUMENT_PACK_P (arg))
18400 tree args = ARGUMENT_PACK_ARGS (arg);
18401 int i, len = TREE_VEC_LENGTH (args);
18402 for (i = 0; i < len; ++i)
18404 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
18410 else if (TYPE_P (arg))
18411 return dependent_type_p (arg);
18413 return (type_dependent_expression_p (arg)
18414 || value_dependent_expression_p (arg));
18417 /* Returns true if ARGS (a collection of template arguments) contains
18418 any types that require structural equality testing. */
18421 any_template_arguments_need_structural_equality_p (tree args)
18428 if (args == error_mark_node)
18431 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
18433 tree level = TMPL_ARGS_LEVEL (args, i + 1);
18434 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
18436 tree arg = TREE_VEC_ELT (level, j);
18437 tree packed_args = NULL_TREE;
18440 if (ARGUMENT_PACK_P (arg))
18442 /* Look inside the argument pack. */
18443 packed_args = ARGUMENT_PACK_ARGS (arg);
18444 len = TREE_VEC_LENGTH (packed_args);
18447 for (k = 0; k < len; ++k)
18450 arg = TREE_VEC_ELT (packed_args, k);
18452 if (error_operand_p (arg))
18454 else if (TREE_CODE (arg) == TEMPLATE_DECL
18455 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
18457 else if (TYPE_P (arg) && TYPE_STRUCTURAL_EQUALITY_P (arg))
18459 else if (!TYPE_P (arg) && TREE_TYPE (arg)
18460 && TYPE_STRUCTURAL_EQUALITY_P (TREE_TYPE (arg)))
18469 /* Returns true if ARGS (a collection of template arguments) contains
18470 any dependent arguments. */
18473 any_dependent_template_arguments_p (const_tree args)
18480 if (args == error_mark_node)
18483 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
18485 const_tree level = TMPL_ARGS_LEVEL (args, i + 1);
18486 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
18487 if (dependent_template_arg_p (TREE_VEC_ELT (level, j)))
18494 /* Returns TRUE if the template TMPL is dependent. */
18497 dependent_template_p (tree tmpl)
18499 if (TREE_CODE (tmpl) == OVERLOAD)
18503 if (dependent_template_p (OVL_FUNCTION (tmpl)))
18505 tmpl = OVL_CHAIN (tmpl);
18510 /* Template template parameters are dependent. */
18511 if (DECL_TEMPLATE_TEMPLATE_PARM_P (tmpl)
18512 || TREE_CODE (tmpl) == TEMPLATE_TEMPLATE_PARM)
18514 /* So are names that have not been looked up. */
18515 if (TREE_CODE (tmpl) == SCOPE_REF
18516 || TREE_CODE (tmpl) == IDENTIFIER_NODE)
18518 /* So are member templates of dependent classes. */
18519 if (TYPE_P (CP_DECL_CONTEXT (tmpl)))
18520 return dependent_type_p (DECL_CONTEXT (tmpl));
18524 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
18527 dependent_template_id_p (tree tmpl, tree args)
18529 return (dependent_template_p (tmpl)
18530 || any_dependent_template_arguments_p (args));
18533 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
18537 dependent_omp_for_p (tree declv, tree initv, tree condv, tree incrv)
18541 if (!processing_template_decl)
18544 for (i = 0; i < TREE_VEC_LENGTH (declv); i++)
18546 tree decl = TREE_VEC_ELT (declv, i);
18547 tree init = TREE_VEC_ELT (initv, i);
18548 tree cond = TREE_VEC_ELT (condv, i);
18549 tree incr = TREE_VEC_ELT (incrv, i);
18551 if (type_dependent_expression_p (decl))
18554 if (init && type_dependent_expression_p (init))
18557 if (type_dependent_expression_p (cond))
18560 if (COMPARISON_CLASS_P (cond)
18561 && (type_dependent_expression_p (TREE_OPERAND (cond, 0))
18562 || type_dependent_expression_p (TREE_OPERAND (cond, 1))))
18565 if (TREE_CODE (incr) == MODOP_EXPR)
18567 if (type_dependent_expression_p (TREE_OPERAND (incr, 0))
18568 || type_dependent_expression_p (TREE_OPERAND (incr, 2)))
18571 else if (type_dependent_expression_p (incr))
18573 else if (TREE_CODE (incr) == MODIFY_EXPR)
18575 if (type_dependent_expression_p (TREE_OPERAND (incr, 0)))
18577 else if (BINARY_CLASS_P (TREE_OPERAND (incr, 1)))
18579 tree t = TREE_OPERAND (incr, 1);
18580 if (type_dependent_expression_p (TREE_OPERAND (t, 0))
18581 || type_dependent_expression_p (TREE_OPERAND (t, 1)))
18590 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
18591 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
18592 no such TYPE can be found. Note that this function peers inside
18593 uninstantiated templates and therefore should be used only in
18594 extremely limited situations. ONLY_CURRENT_P restricts this
18595 peering to the currently open classes hierarchy (which is required
18596 when comparing types). */
18599 resolve_typename_type (tree type, bool only_current_p)
18608 gcc_assert (TREE_CODE (type) == TYPENAME_TYPE);
18610 scope = TYPE_CONTEXT (type);
18611 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
18612 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
18613 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
18614 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
18615 identifier of the TYPENAME_TYPE anymore.
18616 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
18617 TYPENAME_TYPE instead, we avoid messing up with a possible
18618 typedef variant case. */
18619 name = TYPE_IDENTIFIER (TYPE_MAIN_VARIANT (type));
18621 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
18622 it first before we can figure out what NAME refers to. */
18623 if (TREE_CODE (scope) == TYPENAME_TYPE)
18624 scope = resolve_typename_type (scope, only_current_p);
18625 /* If we don't know what SCOPE refers to, then we cannot resolve the
18627 if (TREE_CODE (scope) == TYPENAME_TYPE)
18629 /* If the SCOPE is a template type parameter, we have no way of
18630 resolving the name. */
18631 if (TREE_CODE (scope) == TEMPLATE_TYPE_PARM)
18633 /* If the SCOPE is not the current instantiation, there's no reason
18634 to look inside it. */
18635 if (only_current_p && !currently_open_class (scope))
18637 /* If this is a typedef, we don't want to look inside (c++/11987). */
18638 if (typedef_variant_p (type))
18640 /* If SCOPE isn't the template itself, it will not have a valid
18641 TYPE_FIELDS list. */
18642 if (same_type_p (scope, CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope)))
18643 /* scope is either the template itself or a compatible instantiation
18644 like X<T>, so look up the name in the original template. */
18645 scope = CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope);
18647 /* scope is a partial instantiation, so we can't do the lookup or we
18648 will lose the template arguments. */
18650 /* Enter the SCOPE so that name lookup will be resolved as if we
18651 were in the class definition. In particular, SCOPE will no
18652 longer be considered a dependent type. */
18653 pushed_scope = push_scope (scope);
18654 /* Look up the declaration. */
18655 decl = lookup_member (scope, name, /*protect=*/0, /*want_type=*/true);
18657 result = NULL_TREE;
18659 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
18660 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
18663 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == IDENTIFIER_NODE
18664 && TREE_CODE (decl) == TYPE_DECL)
18666 result = TREE_TYPE (decl);
18667 if (result == error_mark_node)
18668 result = NULL_TREE;
18670 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == TEMPLATE_ID_EXPR
18671 && DECL_CLASS_TEMPLATE_P (decl))
18675 /* Obtain the template and the arguments. */
18676 tmpl = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 0);
18677 args = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 1);
18678 /* Instantiate the template. */
18679 result = lookup_template_class (tmpl, args, NULL_TREE, NULL_TREE,
18680 /*entering_scope=*/0,
18681 tf_error | tf_user);
18682 if (result == error_mark_node)
18683 result = NULL_TREE;
18686 /* Leave the SCOPE. */
18688 pop_scope (pushed_scope);
18690 /* If we failed to resolve it, return the original typename. */
18694 /* If lookup found a typename type, resolve that too. */
18695 if (TREE_CODE (result) == TYPENAME_TYPE && !TYPENAME_IS_RESOLVING_P (result))
18697 /* Ill-formed programs can cause infinite recursion here, so we
18698 must catch that. */
18699 TYPENAME_IS_RESOLVING_P (type) = 1;
18700 result = resolve_typename_type (result, only_current_p);
18701 TYPENAME_IS_RESOLVING_P (type) = 0;
18704 /* Qualify the resulting type. */
18705 quals = cp_type_quals (type);
18707 result = cp_build_qualified_type (result, cp_type_quals (result) | quals);
18712 /* EXPR is an expression which is not type-dependent. Return a proxy
18713 for EXPR that can be used to compute the types of larger
18714 expressions containing EXPR. */
18717 build_non_dependent_expr (tree expr)
18721 /* Preserve null pointer constants so that the type of things like
18722 "p == 0" where "p" is a pointer can be determined. */
18723 if (null_ptr_cst_p (expr))
18725 /* Preserve OVERLOADs; the functions must be available to resolve
18728 if (TREE_CODE (inner_expr) == STMT_EXPR)
18729 inner_expr = stmt_expr_value_expr (inner_expr);
18730 if (TREE_CODE (inner_expr) == ADDR_EXPR)
18731 inner_expr = TREE_OPERAND (inner_expr, 0);
18732 if (TREE_CODE (inner_expr) == COMPONENT_REF)
18733 inner_expr = TREE_OPERAND (inner_expr, 1);
18734 if (is_overloaded_fn (inner_expr)
18735 || TREE_CODE (inner_expr) == OFFSET_REF)
18737 /* There is no need to return a proxy for a variable. */
18738 if (TREE_CODE (expr) == VAR_DECL)
18740 /* Preserve string constants; conversions from string constants to
18741 "char *" are allowed, even though normally a "const char *"
18742 cannot be used to initialize a "char *". */
18743 if (TREE_CODE (expr) == STRING_CST)
18745 /* Preserve arithmetic constants, as an optimization -- there is no
18746 reason to create a new node. */
18747 if (TREE_CODE (expr) == INTEGER_CST || TREE_CODE (expr) == REAL_CST)
18749 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
18750 There is at least one place where we want to know that a
18751 particular expression is a throw-expression: when checking a ?:
18752 expression, there are special rules if the second or third
18753 argument is a throw-expression. */
18754 if (TREE_CODE (expr) == THROW_EXPR)
18757 if (TREE_CODE (expr) == COND_EXPR)
18758 return build3 (COND_EXPR,
18760 TREE_OPERAND (expr, 0),
18761 (TREE_OPERAND (expr, 1)
18762 ? build_non_dependent_expr (TREE_OPERAND (expr, 1))
18763 : build_non_dependent_expr (TREE_OPERAND (expr, 0))),
18764 build_non_dependent_expr (TREE_OPERAND (expr, 2)));
18765 if (TREE_CODE (expr) == COMPOUND_EXPR
18766 && !COMPOUND_EXPR_OVERLOADED (expr))
18767 return build2 (COMPOUND_EXPR,
18769 TREE_OPERAND (expr, 0),
18770 build_non_dependent_expr (TREE_OPERAND (expr, 1)));
18772 /* If the type is unknown, it can't really be non-dependent */
18773 gcc_assert (TREE_TYPE (expr) != unknown_type_node);
18775 /* Otherwise, build a NON_DEPENDENT_EXPR.
18777 REFERENCE_TYPEs are not stripped for expressions in templates
18778 because doing so would play havoc with mangling. Consider, for
18781 template <typename T> void f<T& g>() { g(); }
18783 In the body of "f", the expression for "g" will have
18784 REFERENCE_TYPE, even though the standard says that it should
18785 not. The reason is that we must preserve the syntactic form of
18786 the expression so that mangling (say) "f<g>" inside the body of
18787 "f" works out correctly. Therefore, the REFERENCE_TYPE is
18789 return build1 (NON_DEPENDENT_EXPR, non_reference (TREE_TYPE (expr)), expr);
18792 /* ARGS is a vector of expressions as arguments to a function call.
18793 Replace the arguments with equivalent non-dependent expressions.
18794 This modifies ARGS in place. */
18797 make_args_non_dependent (VEC(tree,gc) *args)
18802 FOR_EACH_VEC_ELT (tree, args, ix, arg)
18804 tree newarg = build_non_dependent_expr (arg);
18806 VEC_replace (tree, args, ix, newarg);
18810 /* Returns a type which represents 'auto'. We use a TEMPLATE_TYPE_PARM
18811 with a level one deeper than the actual template parms. */
18816 tree au = cxx_make_type (TEMPLATE_TYPE_PARM);
18817 TYPE_NAME (au) = build_decl (BUILTINS_LOCATION,
18818 TYPE_DECL, get_identifier ("auto"), au);
18819 TYPE_STUB_DECL (au) = TYPE_NAME (au);
18820 TEMPLATE_TYPE_PARM_INDEX (au) = build_template_parm_index
18821 (0, processing_template_decl + 1, processing_template_decl + 1,
18822 0, TYPE_NAME (au), NULL_TREE);
18823 TYPE_CANONICAL (au) = canonical_type_parameter (au);
18824 DECL_ARTIFICIAL (TYPE_NAME (au)) = 1;
18825 SET_DECL_TEMPLATE_PARM_P (TYPE_NAME (au));
18830 /* Given type ARG, return std::initializer_list<ARG>. */
18835 tree std_init_list = namespace_binding
18836 (get_identifier ("initializer_list"), std_node);
18838 if (!std_init_list || !DECL_CLASS_TEMPLATE_P (std_init_list))
18840 error ("deducing from brace-enclosed initializer list requires "
18841 "#include <initializer_list>");
18842 return error_mark_node;
18844 argvec = make_tree_vec (1);
18845 TREE_VEC_ELT (argvec, 0) = arg;
18846 return lookup_template_class (std_init_list, argvec, NULL_TREE,
18847 NULL_TREE, 0, tf_warning_or_error);
18850 /* Replace auto in TYPE with std::initializer_list<auto>. */
18853 listify_autos (tree type, tree auto_node)
18855 tree init_auto = listify (auto_node);
18856 tree argvec = make_tree_vec (1);
18857 TREE_VEC_ELT (argvec, 0) = init_auto;
18858 if (processing_template_decl)
18859 argvec = add_to_template_args (current_template_args (), argvec);
18860 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
18863 /* walk_tree helper for do_auto_deduction. */
18866 contains_auto_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
18869 /* Is this a variable with the type we're looking for? */
18871 && TREE_TYPE (*tp) == type)
18877 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
18878 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
18881 do_auto_deduction (tree type, tree init, tree auto_node)
18883 tree parms, tparms, targs;
18888 /* The name of the object being declared shall not appear in the
18889 initializer expression. */
18890 decl = cp_walk_tree_without_duplicates (&init, contains_auto_r, type);
18893 error ("variable %q#D with %<auto%> type used in its own "
18894 "initializer", decl);
18895 return error_mark_node;
18898 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
18899 with either a new invented type template parameter U or, if the
18900 initializer is a braced-init-list (8.5.4), with
18901 std::initializer_list<U>. */
18902 if (BRACE_ENCLOSED_INITIALIZER_P (init))
18903 type = listify_autos (type, auto_node);
18905 init = resolve_nondeduced_context (init);
18907 parms = build_tree_list (NULL_TREE, type);
18909 tparms = make_tree_vec (1);
18910 targs = make_tree_vec (1);
18911 TREE_VEC_ELT (tparms, 0)
18912 = build_tree_list (NULL_TREE, TYPE_NAME (auto_node));
18913 val = type_unification_real (tparms, targs, parms, args, 1, 0,
18914 DEDUCE_CALL, LOOKUP_NORMAL);
18917 error ("unable to deduce %qT from %qE", type, init);
18918 return error_mark_node;
18921 /* If the list of declarators contains more than one declarator, the type
18922 of each declared variable is determined as described above. If the
18923 type deduced for the template parameter U is not the same in each
18924 deduction, the program is ill-formed. */
18925 if (TREE_TYPE (auto_node)
18926 && !same_type_p (TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0)))
18928 error ("inconsistent deduction for %qT: %qT and then %qT",
18929 auto_node, TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0));
18930 return error_mark_node;
18932 TREE_TYPE (auto_node) = TREE_VEC_ELT (targs, 0);
18934 if (processing_template_decl)
18935 targs = add_to_template_args (current_template_args (), targs);
18936 return tsubst (type, targs, tf_warning_or_error, NULL_TREE);
18939 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
18943 splice_late_return_type (tree type, tree late_return_type)
18947 if (late_return_type == NULL_TREE)
18949 argvec = make_tree_vec (1);
18950 TREE_VEC_ELT (argvec, 0) = late_return_type;
18951 if (processing_template_decl)
18952 argvec = add_to_template_args (current_template_args (), argvec);
18953 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
18956 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto'. */
18959 is_auto (const_tree type)
18961 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
18962 && TYPE_IDENTIFIER (type) == get_identifier ("auto"))
18968 /* Returns true iff TYPE contains a use of 'auto'. Since auto can only
18969 appear as a type-specifier for the declaration in question, we don't
18970 have to look through the whole type. */
18973 type_uses_auto (tree type)
18975 enum tree_code code;
18976 if (is_auto (type))
18979 code = TREE_CODE (type);
18981 if (code == POINTER_TYPE || code == REFERENCE_TYPE
18982 || code == OFFSET_TYPE || code == FUNCTION_TYPE
18983 || code == METHOD_TYPE || code == ARRAY_TYPE)
18984 return type_uses_auto (TREE_TYPE (type));
18986 if (TYPE_PTRMEMFUNC_P (type))
18987 return type_uses_auto (TREE_TYPE (TREE_TYPE
18988 (TYPE_PTRMEMFUNC_FN_TYPE (type))));
18993 /* For a given template T, return the vector of typedefs referenced
18994 in T for which access check is needed at T instantiation time.
18995 T is either a FUNCTION_DECL or a RECORD_TYPE.
18996 Those typedefs were added to T by the function
18997 append_type_to_template_for_access_check. */
18999 VEC(qualified_typedef_usage_t,gc)*
19000 get_types_needing_access_check (tree t)
19003 VEC(qualified_typedef_usage_t,gc) *result = NULL;
19005 if (!t || t == error_mark_node)
19008 if (!(ti = get_template_info (t)))
19011 if (CLASS_TYPE_P (t)
19012 || TREE_CODE (t) == FUNCTION_DECL)
19014 if (!TI_TEMPLATE (ti))
19017 result = TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti);
19023 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
19024 tied to T. That list of typedefs will be access checked at
19025 T instantiation time.
19026 T is either a FUNCTION_DECL or a RECORD_TYPE.
19027 TYPE_DECL is a TYPE_DECL node representing a typedef.
19028 SCOPE is the scope through which TYPE_DECL is accessed.
19029 LOCATION is the location of the usage point of TYPE_DECL.
19031 This function is a subroutine of
19032 append_type_to_template_for_access_check. */
19035 append_type_to_template_for_access_check_1 (tree t,
19038 location_t location)
19040 qualified_typedef_usage_t typedef_usage;
19043 if (!t || t == error_mark_node)
19046 gcc_assert ((TREE_CODE (t) == FUNCTION_DECL
19047 || CLASS_TYPE_P (t))
19049 && TREE_CODE (type_decl) == TYPE_DECL
19052 if (!(ti = get_template_info (t)))
19055 gcc_assert (TI_TEMPLATE (ti));
19057 typedef_usage.typedef_decl = type_decl;
19058 typedef_usage.context = scope;
19059 typedef_usage.locus = location;
19061 VEC_safe_push (qualified_typedef_usage_t, gc,
19062 TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti),
19066 /* Append TYPE_DECL to the template TEMPL.
19067 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
19068 At TEMPL instanciation time, TYPE_DECL will be checked to see
19069 if it can be accessed through SCOPE.
19070 LOCATION is the location of the usage point of TYPE_DECL.
19072 e.g. consider the following code snippet:
19079 template<class U> struct S
19081 C::myint mi; // <-- usage point of the typedef C::myint
19086 At S<char> instantiation time, we need to check the access of C::myint
19087 In other words, we need to check the access of the myint typedef through
19088 the C scope. For that purpose, this function will add the myint typedef
19089 and the scope C through which its being accessed to a list of typedefs
19090 tied to the template S. That list will be walked at template instantiation
19091 time and access check performed on each typedefs it contains.
19092 Note that this particular code snippet should yield an error because
19093 myint is private to C. */
19096 append_type_to_template_for_access_check (tree templ,
19099 location_t location)
19101 qualified_typedef_usage_t *iter;
19104 gcc_assert (type_decl && (TREE_CODE (type_decl) == TYPE_DECL));
19106 /* Make sure we don't append the type to the template twice. */
19107 FOR_EACH_VEC_ELT (qualified_typedef_usage_t,
19108 get_types_needing_access_check (templ),
19110 if (iter->typedef_decl == type_decl && scope == iter->context)
19113 append_type_to_template_for_access_check_1 (templ, type_decl,
19117 /* Set up the hash tables for template instantiations. */
19120 init_template_processing (void)
19122 decl_specializations = htab_create_ggc (37,
19123 hash_specialization,
19124 eq_specializations,
19126 type_specializations = htab_create_ggc (37,
19127 hash_specialization,
19128 eq_specializations,
19132 /* Print stats about the template hash tables for -fstats. */
19135 print_template_statistics (void)
19137 fprintf (stderr, "decl_specializations: size %ld, %ld elements, "
19138 "%f collisions\n", (long) htab_size (decl_specializations),
19139 (long) htab_elements (decl_specializations),
19140 htab_collisions (decl_specializations));
19141 fprintf (stderr, "type_specializations: size %ld, %ld elements, "
19142 "%f collisions\n", (long) htab_size (type_specializations),
19143 (long) htab_elements (type_specializations),
19144 htab_collisions (type_specializations));
19147 #include "gt-cp-pt.h"