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
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"
39 #include "cp-objcp-common.h"
40 #include "tree-inline.h"
47 #include "tree-iterator.h"
50 /* The type of functions taking a tree, and some additional data, and
52 typedef int (*tree_fn_t) (tree, void*);
54 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
55 instantiations have been deferred, either because their definitions
56 were not yet available, or because we were putting off doing the work. */
57 struct GTY (()) pending_template {
58 struct pending_template *next;
59 struct tinst_level *tinst;
62 static GTY(()) struct pending_template *pending_templates;
63 static GTY(()) struct pending_template *last_pending_template;
65 int processing_template_parmlist;
66 static int template_header_count;
68 static GTY(()) tree saved_trees;
69 static VEC(int,heap) *inline_parm_levels;
71 static GTY(()) struct tinst_level *current_tinst_level;
73 static GTY(()) tree saved_access_scope;
75 /* Live only within one (recursive) call to tsubst_expr. We use
76 this to pass the statement expression node from the STMT_EXPR
77 to the EXPR_STMT that is its result. */
78 static tree cur_stmt_expr;
80 /* A map from local variable declarations in the body of the template
81 presently being instantiated to the corresponding instantiated
83 static htab_t local_specializations;
85 /* Contains canonical template parameter types. The vector is indexed by
86 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
87 TREE_LIST, whose TREE_VALUEs contain the canonical template
88 parameters of various types and levels. */
89 static GTY(()) VEC(tree,gc) *canonical_template_parms;
91 #define UNIFY_ALLOW_NONE 0
92 #define UNIFY_ALLOW_MORE_CV_QUAL 1
93 #define UNIFY_ALLOW_LESS_CV_QUAL 2
94 #define UNIFY_ALLOW_DERIVED 4
95 #define UNIFY_ALLOW_INTEGER 8
96 #define UNIFY_ALLOW_OUTER_LEVEL 16
97 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
98 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
100 static void push_access_scope (tree);
101 static void pop_access_scope (tree);
102 static bool resolve_overloaded_unification (tree, tree, tree, tree,
103 unification_kind_t, int);
104 static int try_one_overload (tree, tree, tree, tree, tree,
105 unification_kind_t, int, bool);
106 static int unify (tree, tree, tree, tree, int);
107 static void add_pending_template (tree);
108 static int push_tinst_level (tree);
109 static void pop_tinst_level (void);
110 static tree reopen_tinst_level (struct tinst_level *);
111 static tree tsubst_initializer_list (tree, tree);
112 static tree get_class_bindings (tree, tree, tree);
113 static tree coerce_template_parms (tree, tree, tree, tsubst_flags_t,
115 static void tsubst_enum (tree, tree, tree);
116 static tree add_to_template_args (tree, tree);
117 static tree add_outermost_template_args (tree, tree);
118 static bool check_instantiated_args (tree, tree, tsubst_flags_t);
119 static int maybe_adjust_types_for_deduction (unification_kind_t, tree*, tree*,
121 static int type_unification_real (tree, tree, tree, const tree *,
122 unsigned int, int, unification_kind_t, int);
123 static void note_template_header (int);
124 static tree convert_nontype_argument_function (tree, tree);
125 static tree convert_nontype_argument (tree, tree);
126 static tree convert_template_argument (tree, tree, tree,
127 tsubst_flags_t, int, tree);
128 static int for_each_template_parm (tree, tree_fn_t, void*,
129 struct pointer_set_t*, bool);
130 static tree expand_template_argument_pack (tree);
131 static tree build_template_parm_index (int, int, int, tree, tree);
132 static bool inline_needs_template_parms (tree);
133 static void push_inline_template_parms_recursive (tree, int);
134 static tree retrieve_local_specialization (tree);
135 static void register_local_specialization (tree, tree);
136 static tree reduce_template_parm_level (tree, tree, int, tree, tsubst_flags_t);
137 static int mark_template_parm (tree, void *);
138 static int template_parm_this_level_p (tree, void *);
139 static tree tsubst_friend_function (tree, tree);
140 static tree tsubst_friend_class (tree, tree);
141 static int can_complete_type_without_circularity (tree);
142 static tree get_bindings (tree, tree, tree, bool);
143 static int template_decl_level (tree);
144 static int check_cv_quals_for_unify (int, tree, tree);
145 static void template_parm_level_and_index (tree, int*, int*);
146 static int unify_pack_expansion (tree, tree, tree, tree, int, bool, bool);
147 static tree tsubst_template_arg (tree, tree, tsubst_flags_t, tree);
148 static tree tsubst_template_args (tree, tree, tsubst_flags_t, tree);
149 static tree tsubst_template_parms (tree, tree, tsubst_flags_t);
150 static void regenerate_decl_from_template (tree, tree);
151 static tree most_specialized_class (tree, tree);
152 static tree tsubst_aggr_type (tree, tree, tsubst_flags_t, tree, int);
153 static tree tsubst_arg_types (tree, tree, tsubst_flags_t, tree);
154 static tree tsubst_function_type (tree, tree, tsubst_flags_t, tree);
155 static bool check_specialization_scope (void);
156 static tree process_partial_specialization (tree);
157 static void set_current_access_from_decl (tree);
158 static tree get_template_base (tree, tree, tree, tree);
159 static tree try_class_unification (tree, tree, tree, tree);
160 static int coerce_template_template_parms (tree, tree, tsubst_flags_t,
162 static bool template_template_parm_bindings_ok_p (tree, tree);
163 static int template_args_equal (tree, tree);
164 static void tsubst_default_arguments (tree);
165 static tree for_each_template_parm_r (tree *, int *, void *);
166 static tree copy_default_args_to_explicit_spec_1 (tree, tree);
167 static void copy_default_args_to_explicit_spec (tree);
168 static int invalid_nontype_parm_type_p (tree, tsubst_flags_t);
169 static int eq_local_specializations (const void *, const void *);
170 static bool dependent_template_arg_p (tree);
171 static bool any_template_arguments_need_structural_equality_p (tree);
172 static bool dependent_type_p_r (tree);
173 static tree tsubst_expr (tree, tree, tsubst_flags_t, tree, bool);
174 static tree tsubst_copy (tree, tree, tsubst_flags_t, tree);
175 static tree tsubst_pack_expansion (tree, tree, tsubst_flags_t, tree);
176 static tree tsubst_decl (tree, tree, tsubst_flags_t);
177 static void perform_typedefs_access_check (tree tmpl, tree targs);
178 static void append_type_to_template_for_access_check_1 (tree, tree, tree);
180 /* Make the current scope suitable for access checking when we are
181 processing T. T can be FUNCTION_DECL for instantiated function
182 template, or VAR_DECL for static member variable (need by
183 instantiate_decl). */
186 push_access_scope (tree t)
188 gcc_assert (TREE_CODE (t) == FUNCTION_DECL
189 || TREE_CODE (t) == VAR_DECL);
191 if (DECL_FRIEND_CONTEXT (t))
192 push_nested_class (DECL_FRIEND_CONTEXT (t));
193 else if (DECL_CLASS_SCOPE_P (t))
194 push_nested_class (DECL_CONTEXT (t));
196 push_to_top_level ();
198 if (TREE_CODE (t) == FUNCTION_DECL)
200 saved_access_scope = tree_cons
201 (NULL_TREE, current_function_decl, saved_access_scope);
202 current_function_decl = t;
206 /* Restore the scope set up by push_access_scope. T is the node we
210 pop_access_scope (tree t)
212 if (TREE_CODE (t) == FUNCTION_DECL)
214 current_function_decl = TREE_VALUE (saved_access_scope);
215 saved_access_scope = TREE_CHAIN (saved_access_scope);
218 if (DECL_FRIEND_CONTEXT (t) || DECL_CLASS_SCOPE_P (t))
221 pop_from_top_level ();
224 /* Do any processing required when DECL (a member template
225 declaration) is finished. Returns the TEMPLATE_DECL corresponding
226 to DECL, unless it is a specialization, in which case the DECL
227 itself is returned. */
230 finish_member_template_decl (tree decl)
232 if (decl == error_mark_node)
233 return error_mark_node;
235 gcc_assert (DECL_P (decl));
237 if (TREE_CODE (decl) == TYPE_DECL)
241 type = TREE_TYPE (decl);
242 if (type == error_mark_node)
243 return error_mark_node;
244 if (MAYBE_CLASS_TYPE_P (type)
245 && CLASSTYPE_TEMPLATE_INFO (type)
246 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
248 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
249 check_member_template (tmpl);
254 else if (TREE_CODE (decl) == FIELD_DECL)
255 error ("data member %qD cannot be a member template", decl);
256 else if (DECL_TEMPLATE_INFO (decl))
258 if (!DECL_TEMPLATE_SPECIALIZATION (decl))
260 check_member_template (DECL_TI_TEMPLATE (decl));
261 return DECL_TI_TEMPLATE (decl);
267 error ("invalid member template declaration %qD", decl);
269 return error_mark_node;
272 /* Return the template info node corresponding to T, whatever T is. */
275 get_template_info (tree t)
277 tree tinfo = NULL_TREE;
279 if (DECL_P (t) && DECL_LANG_SPECIFIC (t))
280 tinfo = DECL_TEMPLATE_INFO (t);
282 if (!tinfo && TREE_CODE (t) == TYPE_DECL)
285 if (TAGGED_TYPE_P (t))
286 tinfo = TYPE_TEMPLATE_INFO (t);
291 /* Returns the template nesting level of the indicated class TYPE.
301 A<T>::B<U> has depth two, while A<T> has depth one.
302 Both A<T>::B<int> and A<int>::B<U> have depth one, if
303 they are instantiations, not specializations.
305 This function is guaranteed to return 0 if passed NULL_TREE so
306 that, for example, `template_class_depth (current_class_type)' is
310 template_class_depth (tree type)
315 type && TREE_CODE (type) != NAMESPACE_DECL;
316 type = (TREE_CODE (type) == FUNCTION_DECL)
317 ? CP_DECL_CONTEXT (type) : TYPE_CONTEXT (type))
319 tree tinfo = get_template_info (type);
321 if (tinfo && PRIMARY_TEMPLATE_P (TI_TEMPLATE (tinfo))
322 && uses_template_parms (INNERMOST_TEMPLATE_ARGS (TI_ARGS (tinfo))))
329 /* Subroutine of maybe_begin_member_template_processing.
330 Returns true if processing DECL needs us to push template parms. */
333 inline_needs_template_parms (tree decl)
335 if (! DECL_TEMPLATE_INFO (decl))
338 return (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (most_general_template (decl)))
339 > (processing_template_decl + DECL_TEMPLATE_SPECIALIZATION (decl)));
342 /* Subroutine of maybe_begin_member_template_processing.
343 Push the template parms in PARMS, starting from LEVELS steps into the
344 chain, and ending at the beginning, since template parms are listed
348 push_inline_template_parms_recursive (tree parmlist, int levels)
350 tree parms = TREE_VALUE (parmlist);
354 push_inline_template_parms_recursive (TREE_CHAIN (parmlist), levels - 1);
356 ++processing_template_decl;
357 current_template_parms
358 = tree_cons (size_int (processing_template_decl),
359 parms, current_template_parms);
360 TEMPLATE_PARMS_FOR_INLINE (current_template_parms) = 1;
362 begin_scope (TREE_VEC_LENGTH (parms) ? sk_template_parms : sk_template_spec,
364 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
366 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
368 if (parm == error_mark_node)
371 gcc_assert (DECL_P (parm));
373 switch (TREE_CODE (parm))
382 /* Make a CONST_DECL as is done in process_template_parm.
383 It is ugly that we recreate this here; the original
384 version built in process_template_parm is no longer
386 tree decl = build_decl (DECL_SOURCE_LOCATION (parm),
387 CONST_DECL, DECL_NAME (parm),
389 DECL_ARTIFICIAL (decl) = 1;
390 TREE_CONSTANT (decl) = 1;
391 TREE_READONLY (decl) = 1;
392 DECL_INITIAL (decl) = DECL_INITIAL (parm);
393 SET_DECL_TEMPLATE_PARM_P (decl);
404 /* Restore the template parameter context for a member template or
405 a friend template defined in a class definition. */
408 maybe_begin_member_template_processing (tree decl)
413 if (inline_needs_template_parms (decl))
415 parms = DECL_TEMPLATE_PARMS (most_general_template (decl));
416 levels = TMPL_PARMS_DEPTH (parms) - processing_template_decl;
418 if (DECL_TEMPLATE_SPECIALIZATION (decl))
421 parms = TREE_CHAIN (parms);
424 push_inline_template_parms_recursive (parms, levels);
427 /* Remember how many levels of template parameters we pushed so that
428 we can pop them later. */
429 VEC_safe_push (int, heap, inline_parm_levels, levels);
432 /* Undo the effects of maybe_begin_member_template_processing. */
435 maybe_end_member_template_processing (void)
440 if (VEC_length (int, inline_parm_levels) == 0)
443 last = VEC_pop (int, inline_parm_levels);
444 for (i = 0; i < last; ++i)
446 --processing_template_decl;
447 current_template_parms = TREE_CHAIN (current_template_parms);
452 /* Return a new template argument vector which contains all of ARGS,
453 but has as its innermost set of arguments the EXTRA_ARGS. */
456 add_to_template_args (tree args, tree extra_args)
463 extra_depth = TMPL_ARGS_DEPTH (extra_args);
464 new_args = make_tree_vec (TMPL_ARGS_DEPTH (args) + extra_depth);
466 for (i = 1; i <= TMPL_ARGS_DEPTH (args); ++i)
467 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (args, i));
469 for (j = 1; j <= extra_depth; ++j, ++i)
470 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (extra_args, j));
475 /* Like add_to_template_args, but only the outermost ARGS are added to
476 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
477 (EXTRA_ARGS) levels are added. This function is used to combine
478 the template arguments from a partial instantiation with the
479 template arguments used to attain the full instantiation from the
480 partial instantiation. */
483 add_outermost_template_args (tree args, tree extra_args)
487 /* If there are more levels of EXTRA_ARGS than there are ARGS,
488 something very fishy is going on. */
489 gcc_assert (TMPL_ARGS_DEPTH (args) >= TMPL_ARGS_DEPTH (extra_args));
491 /* If *all* the new arguments will be the EXTRA_ARGS, just return
493 if (TMPL_ARGS_DEPTH (args) == TMPL_ARGS_DEPTH (extra_args))
496 /* For the moment, we make ARGS look like it contains fewer levels. */
497 TREE_VEC_LENGTH (args) -= TMPL_ARGS_DEPTH (extra_args);
499 new_args = add_to_template_args (args, extra_args);
501 /* Now, we restore ARGS to its full dimensions. */
502 TREE_VEC_LENGTH (args) += TMPL_ARGS_DEPTH (extra_args);
507 /* Return the N levels of innermost template arguments from the ARGS. */
510 get_innermost_template_args (tree args, int n)
518 /* If N is 1, just return the innermost set of template arguments. */
520 return TMPL_ARGS_LEVEL (args, TMPL_ARGS_DEPTH (args));
522 /* If we're not removing anything, just return the arguments we were
524 extra_levels = TMPL_ARGS_DEPTH (args) - n;
525 gcc_assert (extra_levels >= 0);
526 if (extra_levels == 0)
529 /* Make a new set of arguments, not containing the outer arguments. */
530 new_args = make_tree_vec (n);
531 for (i = 1; i <= n; ++i)
532 SET_TMPL_ARGS_LEVEL (new_args, i,
533 TMPL_ARGS_LEVEL (args, i + extra_levels));
538 /* The inverse of get_innermost_template_args: Return all but the innermost
539 EXTRA_LEVELS levels of template arguments from the ARGS. */
542 strip_innermost_template_args (tree args, int extra_levels)
545 int n = TMPL_ARGS_DEPTH (args) - extra_levels;
550 /* If N is 1, just return the outermost set of template arguments. */
552 return TMPL_ARGS_LEVEL (args, 1);
554 /* If we're not removing anything, just return the arguments we were
556 gcc_assert (extra_levels >= 0);
557 if (extra_levels == 0)
560 /* Make a new set of arguments, not containing the inner arguments. */
561 new_args = make_tree_vec (n);
562 for (i = 1; i <= n; ++i)
563 SET_TMPL_ARGS_LEVEL (new_args, i,
564 TMPL_ARGS_LEVEL (args, i));
569 /* We've got a template header coming up; push to a new level for storing
573 begin_template_parm_list (void)
575 /* We use a non-tag-transparent scope here, which causes pushtag to
576 put tags in this scope, rather than in the enclosing class or
577 namespace scope. This is the right thing, since we want
578 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
579 global template class, push_template_decl handles putting the
580 TEMPLATE_DECL into top-level scope. For a nested template class,
583 template <class T> struct S1 {
584 template <class T> struct S2 {};
587 pushtag contains special code to call pushdecl_with_scope on the
588 TEMPLATE_DECL for S2. */
589 begin_scope (sk_template_parms, NULL);
590 ++processing_template_decl;
591 ++processing_template_parmlist;
592 note_template_header (0);
595 /* This routine is called when a specialization is declared. If it is
596 invalid to declare a specialization here, an error is reported and
597 false is returned, otherwise this routine will return true. */
600 check_specialization_scope (void)
602 tree scope = current_scope ();
606 An explicit specialization shall be declared in the namespace of
607 which the template is a member, or, for member templates, in the
608 namespace of which the enclosing class or enclosing class
609 template is a member. An explicit specialization of a member
610 function, member class or static data member of a class template
611 shall be declared in the namespace of which the class template
613 if (scope && TREE_CODE (scope) != NAMESPACE_DECL)
615 error ("explicit specialization in non-namespace scope %qD", scope);
621 In an explicit specialization declaration for a member of a class
622 template or a member template that appears in namespace scope,
623 the member template and some of its enclosing class templates may
624 remain unspecialized, except that the declaration shall not
625 explicitly specialize a class member template if its enclosing
626 class templates are not explicitly specialized as well. */
627 if (current_template_parms)
629 error ("enclosing class templates are not explicitly specialized");
636 /* We've just seen template <>. */
639 begin_specialization (void)
641 begin_scope (sk_template_spec, NULL);
642 note_template_header (1);
643 return check_specialization_scope ();
646 /* Called at then end of processing a declaration preceded by
650 end_specialization (void)
653 reset_specialization ();
656 /* Any template <>'s that we have seen thus far are not referring to a
657 function specialization. */
660 reset_specialization (void)
662 processing_specialization = 0;
663 template_header_count = 0;
666 /* We've just seen a template header. If SPECIALIZATION is nonzero,
667 it was of the form template <>. */
670 note_template_header (int specialization)
672 processing_specialization = specialization;
673 template_header_count++;
676 /* We're beginning an explicit instantiation. */
679 begin_explicit_instantiation (void)
681 gcc_assert (!processing_explicit_instantiation);
682 processing_explicit_instantiation = true;
687 end_explicit_instantiation (void)
689 gcc_assert (processing_explicit_instantiation);
690 processing_explicit_instantiation = false;
693 /* An explicit specialization or partial specialization TMPL is being
694 declared. Check that the namespace in which the specialization is
695 occurring is permissible. Returns false iff it is invalid to
696 specialize TMPL in the current namespace. */
699 check_specialization_namespace (tree tmpl)
701 tree tpl_ns = decl_namespace_context (tmpl);
705 An explicit specialization shall be declared in the namespace of
706 which the template is a member, or, for member templates, in the
707 namespace of which the enclosing class or enclosing class
708 template is a member. An explicit specialization of a member
709 function, member class or static data member of a class template
710 shall be declared in the namespace of which the class template is
712 if (is_associated_namespace (current_namespace, tpl_ns))
713 /* Same or super-using namespace. */
717 permerror (input_location, "specialization of %qD in different namespace", tmpl);
718 permerror (input_location, " from definition of %q+#D", tmpl);
723 /* SPEC is an explicit instantiation. Check that it is valid to
724 perform this explicit instantiation in the current namespace. */
727 check_explicit_instantiation_namespace (tree spec)
731 /* DR 275: An explicit instantiation shall appear in an enclosing
732 namespace of its template. */
733 ns = decl_namespace_context (spec);
734 if (!is_ancestor (current_namespace, ns))
735 permerror (input_location, "explicit instantiation of %qD in namespace %qD "
736 "(which does not enclose namespace %qD)",
737 spec, current_namespace, ns);
740 /* The TYPE is being declared. If it is a template type, that means it
741 is a partial specialization. Do appropriate error-checking. */
744 maybe_process_partial_specialization (tree type)
748 if (type == error_mark_node)
749 return error_mark_node;
751 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
753 error ("name of class shadows template template parameter %qD",
755 return error_mark_node;
758 context = TYPE_CONTEXT (type);
760 if (CLASS_TYPE_P (type) && CLASSTYPE_USE_TEMPLATE (type))
762 /* This is for ordinary explicit specialization and partial
763 specialization of a template class such as:
765 template <> class C<int>;
769 template <class T> class C<T*>;
771 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
773 if (CLASSTYPE_IMPLICIT_INSTANTIATION (type)
774 && !COMPLETE_TYPE_P (type))
776 check_specialization_namespace (CLASSTYPE_TI_TEMPLATE (type));
777 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
778 if (processing_template_decl)
780 if (push_template_decl (TYPE_MAIN_DECL (type))
782 return error_mark_node;
785 else if (CLASSTYPE_TEMPLATE_INSTANTIATION (type))
786 error ("specialization of %qT after instantiation", type);
788 else if (CLASS_TYPE_P (type)
789 && !CLASSTYPE_USE_TEMPLATE (type)
790 && CLASSTYPE_TEMPLATE_INFO (type)
791 && context && CLASS_TYPE_P (context)
792 && CLASSTYPE_TEMPLATE_INFO (context))
794 /* This is for an explicit specialization of member class
795 template according to [temp.expl.spec/18]:
797 template <> template <class U> class C<int>::D;
799 The context `C<int>' must be an implicit instantiation.
800 Otherwise this is just a member class template declared
803 template <> class C<int> { template <class U> class D; };
804 template <> template <class U> class C<int>::D;
806 In the first case, `C<int>::D' is a specialization of `C<T>::D'
807 while in the second case, `C<int>::D' is a primary template
808 and `C<T>::D' may not exist. */
810 if (CLASSTYPE_IMPLICIT_INSTANTIATION (context)
811 && !COMPLETE_TYPE_P (type))
815 if (current_namespace
816 != decl_namespace_context (CLASSTYPE_TI_TEMPLATE (type)))
818 permerror (input_location, "specializing %q#T in different namespace", type);
819 permerror (input_location, " from definition of %q+#D",
820 CLASSTYPE_TI_TEMPLATE (type));
823 /* Check for invalid specialization after instantiation:
825 template <> template <> class C<int>::D<int>;
826 template <> template <class U> class C<int>::D; */
828 for (t = DECL_TEMPLATE_INSTANTIATIONS
829 (most_general_template (CLASSTYPE_TI_TEMPLATE (type)));
830 t; t = TREE_CHAIN (t))
831 if (TREE_VALUE (t) != type
832 && TYPE_CONTEXT (TREE_VALUE (t)) == context)
833 error ("specialization %qT after instantiation %qT",
834 type, TREE_VALUE (t));
836 /* Mark TYPE as a specialization. And as a result, we only
837 have one level of template argument for the innermost
839 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
840 CLASSTYPE_TI_ARGS (type)
841 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type));
844 else if (processing_specialization)
846 error ("explicit specialization of non-template %qT", type);
847 return error_mark_node;
853 /* Returns nonzero if we can optimize the retrieval of specializations
854 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
855 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
858 optimize_specialization_lookup_p (tree tmpl)
860 return (DECL_FUNCTION_TEMPLATE_P (tmpl)
861 && DECL_CLASS_SCOPE_P (tmpl)
862 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
864 && CLASS_TYPE_P (DECL_CONTEXT (tmpl))
865 /* The optimized lookup depends on the fact that the
866 template arguments for the member function template apply
867 purely to the containing class, which is not true if the
868 containing class is an explicit or partial
870 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (tmpl))
871 && !DECL_MEMBER_TEMPLATE_P (tmpl)
872 && !DECL_CONV_FN_P (tmpl)
873 /* It is possible to have a template that is not a member
874 template and is not a member of a template class:
876 template <typename T>
877 struct S { friend A::f(); };
879 Here, the friend function is a template, but the context does
880 not have template information. The optimized lookup relies
881 on having ARGS be the template arguments for both the class
882 and the function template. */
883 && !DECL_FRIEND_P (DECL_TEMPLATE_RESULT (tmpl)));
886 /* Retrieve the specialization (in the sense of [temp.spec] - a
887 specialization is either an instantiation or an explicit
888 specialization) of TMPL for the given template ARGS. If there is
889 no such specialization, return NULL_TREE. The ARGS are a vector of
890 arguments, or a vector of vectors of arguments, in the case of
891 templates with more than one level of parameters.
893 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
894 then we search for a partial specialization matching ARGS. This
895 parameter is ignored if TMPL is not a class template. */
898 retrieve_specialization (tree tmpl, tree args,
899 bool class_specializations_p)
901 if (args == error_mark_node)
904 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
906 /* There should be as many levels of arguments as there are
907 levels of parameters. */
908 gcc_assert (TMPL_ARGS_DEPTH (args)
909 == TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl)));
911 if (optimize_specialization_lookup_p (tmpl))
914 tree class_specialization;
915 VEC(tree,gc) *methods;
919 /* The template arguments actually apply to the containing
920 class. Find the class specialization with those
922 class_template = CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (tmpl));
924 = retrieve_specialization (class_template, args,
925 /*class_specializations_p=*/false);
926 if (!class_specialization)
928 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
929 for the specialization. */
930 idx = class_method_index_for_fn (class_specialization, tmpl);
933 /* Iterate through the methods with the indicated name, looking
934 for the one that has an instance of TMPL. */
935 methods = CLASSTYPE_METHOD_VEC (class_specialization);
936 for (fns = VEC_index (tree, methods, idx); fns; fns = OVL_NEXT (fns))
938 tree fn = OVL_CURRENT (fns);
939 if (DECL_TEMPLATE_INFO (fn) && DECL_TI_TEMPLATE (fn) == tmpl)
949 /* Class templates store their instantiations on the
950 DECL_TEMPLATE_INSTANTIATIONS list; other templates use the
951 DECL_TEMPLATE_SPECIALIZATIONS list. */
952 if (!class_specializations_p
953 && TREE_CODE (DECL_TEMPLATE_RESULT (tmpl)) == TYPE_DECL
954 && !is_typedef_decl (DECL_TEMPLATE_RESULT (tmpl))
955 && TAGGED_TYPE_P (TREE_TYPE (tmpl)))
956 sp = &DECL_TEMPLATE_INSTANTIATIONS (tmpl);
958 sp = &DECL_TEMPLATE_SPECIALIZATIONS (tmpl);
960 /* Iterate through the list until we find a matching template. */
961 while (*sp != NULL_TREE)
965 if (comp_template_args (TREE_PURPOSE (spec), args))
967 /* Use the move-to-front heuristic to speed up future
971 *sp = TREE_CHAIN (*sp);
972 TREE_CHAIN (spec) = *head;
975 return TREE_VALUE (spec);
977 sp = &TREE_CHAIN (spec);
984 /* Like retrieve_specialization, but for local declarations. */
987 retrieve_local_specialization (tree tmpl)
991 if (local_specializations == NULL)
994 spec = (tree) htab_find_with_hash (local_specializations, tmpl,
995 htab_hash_pointer (tmpl));
996 return spec ? TREE_PURPOSE (spec) : NULL_TREE;
999 /* Returns nonzero iff DECL is a specialization of TMPL. */
1002 is_specialization_of (tree decl, tree tmpl)
1006 if (TREE_CODE (decl) == FUNCTION_DECL)
1010 t = DECL_TEMPLATE_INFO (t) ? DECL_TI_TEMPLATE (t) : NULL_TREE)
1016 gcc_assert (TREE_CODE (decl) == TYPE_DECL);
1018 for (t = TREE_TYPE (decl);
1020 t = CLASSTYPE_USE_TEMPLATE (t)
1021 ? TREE_TYPE (CLASSTYPE_TI_TEMPLATE (t)) : NULL_TREE)
1022 if (same_type_ignoring_top_level_qualifiers_p (t, TREE_TYPE (tmpl)))
1029 /* Returns nonzero iff DECL is a specialization of friend declaration
1030 FRIEND_DECL according to [temp.friend]. */
1033 is_specialization_of_friend (tree decl, tree friend_decl)
1035 bool need_template = true;
1038 gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
1039 || TREE_CODE (decl) == TYPE_DECL);
1041 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1042 of a template class, we want to check if DECL is a specialization
1044 if (TREE_CODE (friend_decl) == FUNCTION_DECL
1045 && DECL_TEMPLATE_INFO (friend_decl)
1046 && !DECL_USE_TEMPLATE (friend_decl))
1048 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1049 friend_decl = DECL_TI_TEMPLATE (friend_decl);
1050 need_template = false;
1052 else if (TREE_CODE (friend_decl) == TEMPLATE_DECL
1053 && !PRIMARY_TEMPLATE_P (friend_decl))
1054 need_template = false;
1056 /* There is nothing to do if this is not a template friend. */
1057 if (TREE_CODE (friend_decl) != TEMPLATE_DECL)
1060 if (is_specialization_of (decl, friend_decl))
1064 A member of a class template may be declared to be a friend of a
1065 non-template class. In this case, the corresponding member of
1066 every specialization of the class template is a friend of the
1067 class granting friendship.
1069 For example, given a template friend declaration
1071 template <class T> friend void A<T>::f();
1073 the member function below is considered a friend
1075 template <> struct A<int> {
1079 For this type of template friend, TEMPLATE_DEPTH below will be
1080 nonzero. To determine if DECL is a friend of FRIEND, we first
1081 check if the enclosing class is a specialization of another. */
1083 template_depth = template_class_depth (DECL_CONTEXT (friend_decl));
1085 && DECL_CLASS_SCOPE_P (decl)
1086 && is_specialization_of (TYPE_NAME (DECL_CONTEXT (decl)),
1087 CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (friend_decl))))
1089 /* Next, we check the members themselves. In order to handle
1090 a few tricky cases, such as when FRIEND_DECL's are
1092 template <class T> friend void A<T>::g(T t);
1093 template <class T> template <T t> friend void A<T>::h();
1097 void A<int>::g(int);
1098 template <int> void A<int>::h();
1100 we need to figure out ARGS, the template arguments from
1101 the context of DECL. This is required for template substitution
1102 of `T' in the function parameter of `g' and template parameter
1103 of `h' in the above examples. Here ARGS corresponds to `int'. */
1105 tree context = DECL_CONTEXT (decl);
1106 tree args = NULL_TREE;
1107 int current_depth = 0;
1109 while (current_depth < template_depth)
1111 if (CLASSTYPE_TEMPLATE_INFO (context))
1113 if (current_depth == 0)
1114 args = TYPE_TI_ARGS (context);
1116 args = add_to_template_args (TYPE_TI_ARGS (context), args);
1119 context = TYPE_CONTEXT (context);
1122 if (TREE_CODE (decl) == FUNCTION_DECL)
1127 tree friend_args_type;
1128 tree decl_args_type;
1130 /* Make sure that both DECL and FRIEND_DECL are templates or
1132 is_template = DECL_TEMPLATE_INFO (decl)
1133 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (decl));
1134 if (need_template ^ is_template)
1136 else if (is_template)
1138 /* If both are templates, check template parameter list. */
1140 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1142 if (!comp_template_parms
1143 (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (decl)),
1147 decl_type = TREE_TYPE (DECL_TI_TEMPLATE (decl));
1150 decl_type = TREE_TYPE (decl);
1152 friend_type = tsubst_function_type (TREE_TYPE (friend_decl), args,
1153 tf_none, NULL_TREE);
1154 if (friend_type == error_mark_node)
1157 /* Check if return types match. */
1158 if (!same_type_p (TREE_TYPE (decl_type), TREE_TYPE (friend_type)))
1161 /* Check if function parameter types match, ignoring the
1162 `this' parameter. */
1163 friend_args_type = TYPE_ARG_TYPES (friend_type);
1164 decl_args_type = TYPE_ARG_TYPES (decl_type);
1165 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (friend_decl))
1166 friend_args_type = TREE_CHAIN (friend_args_type);
1167 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1168 decl_args_type = TREE_CHAIN (decl_args_type);
1170 return compparms (decl_args_type, friend_args_type);
1174 /* DECL is a TYPE_DECL */
1176 tree decl_type = TREE_TYPE (decl);
1178 /* Make sure that both DECL and FRIEND_DECL are templates or
1181 = CLASSTYPE_TEMPLATE_INFO (decl_type)
1182 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (decl_type));
1184 if (need_template ^ is_template)
1186 else if (is_template)
1189 /* If both are templates, check the name of the two
1190 TEMPLATE_DECL's first because is_friend didn't. */
1191 if (DECL_NAME (CLASSTYPE_TI_TEMPLATE (decl_type))
1192 != DECL_NAME (friend_decl))
1195 /* Now check template parameter list. */
1197 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1199 return comp_template_parms
1200 (DECL_TEMPLATE_PARMS (CLASSTYPE_TI_TEMPLATE (decl_type)),
1204 return (DECL_NAME (decl)
1205 == DECL_NAME (friend_decl));
1211 /* Register the specialization SPEC as a specialization of TMPL with
1212 the indicated ARGS. IS_FRIEND indicates whether the specialization
1213 is actually just a friend declaration. Returns SPEC, or an
1214 equivalent prior declaration, if available. */
1217 register_specialization (tree spec, tree tmpl, tree args, bool is_friend)
1221 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
1223 if (TREE_CODE (spec) == FUNCTION_DECL
1224 && uses_template_parms (DECL_TI_ARGS (spec)))
1225 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1226 register it; we want the corresponding TEMPLATE_DECL instead.
1227 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1228 the more obvious `uses_template_parms (spec)' to avoid problems
1229 with default function arguments. In particular, given
1230 something like this:
1232 template <class T> void f(T t1, T t = T())
1234 the default argument expression is not substituted for in an
1235 instantiation unless and until it is actually needed. */
1238 fn = retrieve_specialization (tmpl, args,
1239 /*class_specializations_p=*/false);
1240 /* We can sometimes try to re-register a specialization that we've
1241 already got. In particular, regenerate_decl_from_template calls
1242 duplicate_decls which will update the specialization list. But,
1243 we'll still get called again here anyhow. It's more convenient
1244 to simply allow this than to try to prevent it. */
1247 else if (fn && DECL_TEMPLATE_SPECIALIZATION (spec))
1249 if (DECL_TEMPLATE_INSTANTIATION (fn))
1252 || DECL_EXPLICIT_INSTANTIATION (fn))
1254 error ("specialization of %qD after instantiation",
1256 return error_mark_node;
1261 /* This situation should occur only if the first
1262 specialization is an implicit instantiation, the
1263 second is an explicit specialization, and the
1264 implicit instantiation has not yet been used. That
1265 situation can occur if we have implicitly
1266 instantiated a member function and then specialized
1269 We can also wind up here if a friend declaration that
1270 looked like an instantiation turns out to be a
1273 template <class T> void foo(T);
1274 class S { friend void foo<>(int) };
1275 template <> void foo(int);
1277 We transform the existing DECL in place so that any
1278 pointers to it become pointers to the updated
1281 If there was a definition for the template, but not
1282 for the specialization, we want this to look as if
1283 there were no definition, and vice versa. */
1284 DECL_INITIAL (fn) = NULL_TREE;
1285 duplicate_decls (spec, fn, is_friend);
1286 /* The call to duplicate_decls will have applied
1289 An explicit specialization of a function template
1290 is inline only if it is explicitly declared to be,
1291 and independently of whether its function template
1294 to the primary function; now copy the inline bits to
1295 the various clones. */
1296 FOR_EACH_CLONE (clone, fn)
1297 DECL_DECLARED_INLINE_P (clone)
1298 = DECL_DECLARED_INLINE_P (fn);
1299 check_specialization_namespace (fn);
1304 else if (DECL_TEMPLATE_SPECIALIZATION (fn))
1306 if (!duplicate_decls (spec, fn, is_friend) && DECL_INITIAL (spec))
1307 /* Dup decl failed, but this is a new definition. Set the
1308 line number so any errors match this new
1310 DECL_SOURCE_LOCATION (fn) = DECL_SOURCE_LOCATION (spec);
1316 /* A specialization must be declared in the same namespace as the
1317 template it is specializing. */
1318 if (DECL_TEMPLATE_SPECIALIZATION (spec)
1319 && !check_specialization_namespace (tmpl))
1320 DECL_CONTEXT (spec) = DECL_CONTEXT (tmpl);
1322 if (!optimize_specialization_lookup_p (tmpl))
1323 DECL_TEMPLATE_SPECIALIZATIONS (tmpl)
1324 = tree_cons (args, spec, DECL_TEMPLATE_SPECIALIZATIONS (tmpl));
1329 /* Unregister the specialization SPEC as a specialization of TMPL.
1330 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1331 if the SPEC was listed as a specialization of TMPL. */
1334 reregister_specialization (tree spec, tree tmpl, tree new_spec)
1338 for (s = &DECL_TEMPLATE_SPECIALIZATIONS (tmpl);
1340 s = &TREE_CHAIN (*s))
1341 if (TREE_VALUE (*s) == spec)
1344 *s = TREE_CHAIN (*s);
1346 TREE_VALUE (*s) = new_spec;
1353 /* Compare an entry in the local specializations hash table P1 (which
1354 is really a pointer to a TREE_LIST) with P2 (which is really a
1358 eq_local_specializations (const void *p1, const void *p2)
1360 return TREE_VALUE ((const_tree) p1) == (const_tree) p2;
1363 /* Hash P1, an entry in the local specializations table. */
1366 hash_local_specialization (const void* p1)
1368 return htab_hash_pointer (TREE_VALUE ((const_tree) p1));
1371 /* Like register_specialization, but for local declarations. We are
1372 registering SPEC, an instantiation of TMPL. */
1375 register_local_specialization (tree spec, tree tmpl)
1379 slot = htab_find_slot_with_hash (local_specializations, tmpl,
1380 htab_hash_pointer (tmpl), INSERT);
1381 *slot = build_tree_list (spec, tmpl);
1384 /* TYPE is a class type. Returns true if TYPE is an explicitly
1385 specialized class. */
1388 explicit_class_specialization_p (tree type)
1390 if (!CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
1392 return !uses_template_parms (CLASSTYPE_TI_ARGS (type));
1395 /* Print the list of candidate FNS in an error message. */
1398 print_candidates (tree fns)
1402 const char *str = "candidates are:";
1404 for (fn = fns; fn != NULL_TREE; fn = TREE_CHAIN (fn))
1408 for (f = TREE_VALUE (fn); f; f = OVL_NEXT (f))
1409 error ("%s %+#D", str, OVL_CURRENT (f));
1414 /* Returns the template (one of the functions given by TEMPLATE_ID)
1415 which can be specialized to match the indicated DECL with the
1416 explicit template args given in TEMPLATE_ID. The DECL may be
1417 NULL_TREE if none is available. In that case, the functions in
1418 TEMPLATE_ID are non-members.
1420 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1421 specialization of a member template.
1423 The TEMPLATE_COUNT is the number of references to qualifying
1424 template classes that appeared in the name of the function. See
1425 check_explicit_specialization for a more accurate description.
1427 TSK indicates what kind of template declaration (if any) is being
1428 declared. TSK_TEMPLATE indicates that the declaration given by
1429 DECL, though a FUNCTION_DECL, has template parameters, and is
1430 therefore a template function.
1432 The template args (those explicitly specified and those deduced)
1433 are output in a newly created vector *TARGS_OUT.
1435 If it is impossible to determine the result, an error message is
1436 issued. The error_mark_node is returned to indicate failure. */
1439 determine_specialization (tree template_id,
1442 int need_member_template,
1448 tree explicit_targs;
1449 tree candidates = NULL_TREE;
1450 /* A TREE_LIST of templates of which DECL may be a specialization.
1451 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1452 corresponding TREE_PURPOSE is the set of template arguments that,
1453 when used to instantiate the template, would produce a function
1454 with the signature of DECL. */
1455 tree templates = NULL_TREE;
1457 struct cp_binding_level *b;
1459 *targs_out = NULL_TREE;
1461 if (template_id == error_mark_node || decl == error_mark_node)
1462 return error_mark_node;
1464 fns = TREE_OPERAND (template_id, 0);
1465 explicit_targs = TREE_OPERAND (template_id, 1);
1467 if (fns == error_mark_node)
1468 return error_mark_node;
1470 /* Check for baselinks. */
1471 if (BASELINK_P (fns))
1472 fns = BASELINK_FUNCTIONS (fns);
1474 if (!is_overloaded_fn (fns))
1476 error ("%qD is not a function template", fns);
1477 return error_mark_node;
1480 /* Count the number of template headers specified for this
1483 for (b = current_binding_level;
1484 b->kind == sk_template_parms;
1488 for (; fns; fns = OVL_NEXT (fns))
1490 tree fn = OVL_CURRENT (fns);
1492 if (TREE_CODE (fn) == TEMPLATE_DECL)
1494 tree decl_arg_types;
1497 /* In case of explicit specialization, we need to check if
1498 the number of template headers appearing in the specialization
1499 is correct. This is usually done in check_explicit_specialization,
1500 but the check done there cannot be exhaustive when specializing
1501 member functions. Consider the following code:
1503 template <> void A<int>::f(int);
1504 template <> template <> void A<int>::f(int);
1506 Assuming that A<int> is not itself an explicit specialization
1507 already, the first line specializes "f" which is a non-template
1508 member function, whilst the second line specializes "f" which
1509 is a template member function. So both lines are syntactically
1510 correct, and check_explicit_specialization does not reject
1513 Here, we can do better, as we are matching the specialization
1514 against the declarations. We count the number of template
1515 headers, and we check if they match TEMPLATE_COUNT + 1
1516 (TEMPLATE_COUNT is the number of qualifying template classes,
1517 plus there must be another header for the member template
1520 Notice that if header_count is zero, this is not a
1521 specialization but rather a template instantiation, so there
1522 is no check we can perform here. */
1523 if (header_count && header_count != template_count + 1)
1526 /* Check that the number of template arguments at the
1527 innermost level for DECL is the same as for FN. */
1528 if (current_binding_level->kind == sk_template_parms
1529 && !current_binding_level->explicit_spec_p
1530 && (TREE_VEC_LENGTH (DECL_INNERMOST_TEMPLATE_PARMS (fn))
1531 != TREE_VEC_LENGTH (INNERMOST_TEMPLATE_PARMS
1532 (current_template_parms))))
1535 /* DECL might be a specialization of FN. */
1536 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1537 fn_arg_types = TYPE_ARG_TYPES (TREE_TYPE (fn));
1539 /* For a non-static member function, we need to make sure
1540 that the const qualification is the same. Since
1541 get_bindings does not try to merge the "this" parameter,
1542 we must do the comparison explicitly. */
1543 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
1544 && !same_type_p (TREE_VALUE (fn_arg_types),
1545 TREE_VALUE (decl_arg_types)))
1548 /* Skip the "this" parameter and, for constructors of
1549 classes with virtual bases, the VTT parameter. A
1550 full specialization of a constructor will have a VTT
1551 parameter, but a template never will. */
1553 = skip_artificial_parms_for (decl, decl_arg_types);
1555 = skip_artificial_parms_for (fn, fn_arg_types);
1557 /* Check that the number of function parameters matches.
1559 template <class T> void f(int i = 0);
1560 template <> void f<int>();
1561 The specialization f<int> is invalid but is not caught
1562 by get_bindings below. */
1563 if (list_length (fn_arg_types) != list_length (decl_arg_types))
1566 /* Function templates cannot be specializations; there are
1567 no partial specializations of functions. Therefore, if
1568 the type of DECL does not match FN, there is no
1570 if (tsk == tsk_template)
1572 if (compparms (fn_arg_types, decl_arg_types))
1573 candidates = tree_cons (NULL_TREE, fn, candidates);
1577 /* See whether this function might be a specialization of this
1579 targs = get_bindings (fn, decl, explicit_targs, /*check_ret=*/true);
1582 /* We cannot deduce template arguments that when used to
1583 specialize TMPL will produce DECL. */
1586 /* Save this template, and the arguments deduced. */
1587 templates = tree_cons (targs, fn, templates);
1589 else if (need_member_template)
1590 /* FN is an ordinary member function, and we need a
1591 specialization of a member template. */
1593 else if (TREE_CODE (fn) != FUNCTION_DECL)
1594 /* We can get IDENTIFIER_NODEs here in certain erroneous
1597 else if (!DECL_FUNCTION_MEMBER_P (fn))
1598 /* This is just an ordinary non-member function. Nothing can
1599 be a specialization of that. */
1601 else if (DECL_ARTIFICIAL (fn))
1602 /* Cannot specialize functions that are created implicitly. */
1606 tree decl_arg_types;
1608 /* This is an ordinary member function. However, since
1609 we're here, we can assume it's enclosing class is a
1610 template class. For example,
1612 template <typename T> struct S { void f(); };
1613 template <> void S<int>::f() {}
1615 Here, S<int>::f is a non-template, but S<int> is a
1616 template class. If FN has the same type as DECL, we
1617 might be in business. */
1619 if (!DECL_TEMPLATE_INFO (fn))
1620 /* Its enclosing class is an explicit specialization
1621 of a template class. This is not a candidate. */
1624 if (!same_type_p (TREE_TYPE (TREE_TYPE (decl)),
1625 TREE_TYPE (TREE_TYPE (fn))))
1626 /* The return types differ. */
1629 /* Adjust the type of DECL in case FN is a static member. */
1630 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1631 if (DECL_STATIC_FUNCTION_P (fn)
1632 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1633 decl_arg_types = TREE_CHAIN (decl_arg_types);
1635 if (compparms (TYPE_ARG_TYPES (TREE_TYPE (fn)),
1638 candidates = tree_cons (NULL_TREE, fn, candidates);
1642 if (templates && TREE_CHAIN (templates))
1648 It is possible for a specialization with a given function
1649 signature to be instantiated from more than one function
1650 template. In such cases, explicit specification of the
1651 template arguments must be used to uniquely identify the
1652 function template specialization being specialized.
1654 Note that here, there's no suggestion that we're supposed to
1655 determine which of the candidate templates is most
1656 specialized. However, we, also have:
1660 Partial ordering of overloaded function template
1661 declarations is used in the following contexts to select
1662 the function template to which a function template
1663 specialization refers:
1665 -- when an explicit specialization refers to a function
1668 So, we do use the partial ordering rules, at least for now.
1669 This extension can only serve to make invalid programs valid,
1670 so it's safe. And, there is strong anecdotal evidence that
1671 the committee intended the partial ordering rules to apply;
1672 the EDG front end has that behavior, and John Spicer claims
1673 that the committee simply forgot to delete the wording in
1674 [temp.expl.spec]. */
1675 tree tmpl = most_specialized_instantiation (templates);
1676 if (tmpl != error_mark_node)
1679 TREE_CHAIN (templates) = NULL_TREE;
1683 if (templates == NULL_TREE && candidates == NULL_TREE)
1685 error ("template-id %qD for %q+D does not match any template "
1686 "declaration", template_id, decl);
1687 return error_mark_node;
1689 else if ((templates && TREE_CHAIN (templates))
1690 || (candidates && TREE_CHAIN (candidates))
1691 || (templates && candidates))
1693 error ("ambiguous template specialization %qD for %q+D",
1695 chainon (candidates, templates);
1696 print_candidates (candidates);
1697 return error_mark_node;
1700 /* We have one, and exactly one, match. */
1703 tree fn = TREE_VALUE (candidates);
1704 /* DECL is a re-declaration of a template function. */
1705 if (TREE_CODE (fn) == TEMPLATE_DECL)
1707 /* It was a specialization of an ordinary member function in a
1709 *targs_out = copy_node (DECL_TI_ARGS (fn));
1710 return DECL_TI_TEMPLATE (fn);
1713 /* It was a specialization of a template. */
1714 targs = DECL_TI_ARGS (DECL_TEMPLATE_RESULT (TREE_VALUE (templates)));
1715 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (targs))
1717 *targs_out = copy_node (targs);
1718 SET_TMPL_ARGS_LEVEL (*targs_out,
1719 TMPL_ARGS_DEPTH (*targs_out),
1720 TREE_PURPOSE (templates));
1723 *targs_out = TREE_PURPOSE (templates);
1724 return TREE_VALUE (templates);
1727 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
1728 but with the default argument values filled in from those in the
1732 copy_default_args_to_explicit_spec_1 (tree spec_types,
1735 tree new_spec_types;
1740 if (spec_types == void_list_node)
1741 return void_list_node;
1743 /* Substitute into the rest of the list. */
1745 copy_default_args_to_explicit_spec_1 (TREE_CHAIN (spec_types),
1746 TREE_CHAIN (tmpl_types));
1748 /* Add the default argument for this parameter. */
1749 return hash_tree_cons (TREE_PURPOSE (tmpl_types),
1750 TREE_VALUE (spec_types),
1754 /* DECL is an explicit specialization. Replicate default arguments
1755 from the template it specializes. (That way, code like:
1757 template <class T> void f(T = 3);
1758 template <> void f(double);
1761 works, as required.) An alternative approach would be to look up
1762 the correct default arguments at the call-site, but this approach
1763 is consistent with how implicit instantiations are handled. */
1766 copy_default_args_to_explicit_spec (tree decl)
1771 tree new_spec_types;
1775 tree object_type = NULL_TREE;
1776 tree in_charge = NULL_TREE;
1777 tree vtt = NULL_TREE;
1779 /* See if there's anything we need to do. */
1780 tmpl = DECL_TI_TEMPLATE (decl);
1781 tmpl_types = TYPE_ARG_TYPES (TREE_TYPE (DECL_TEMPLATE_RESULT (tmpl)));
1782 for (t = tmpl_types; t; t = TREE_CHAIN (t))
1783 if (TREE_PURPOSE (t))
1788 old_type = TREE_TYPE (decl);
1789 spec_types = TYPE_ARG_TYPES (old_type);
1791 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1793 /* Remove the this pointer, but remember the object's type for
1795 object_type = TREE_TYPE (TREE_VALUE (spec_types));
1796 spec_types = TREE_CHAIN (spec_types);
1797 tmpl_types = TREE_CHAIN (tmpl_types);
1799 if (DECL_HAS_IN_CHARGE_PARM_P (decl))
1801 /* DECL may contain more parameters than TMPL due to the extra
1802 in-charge parameter in constructors and destructors. */
1803 in_charge = spec_types;
1804 spec_types = TREE_CHAIN (spec_types);
1806 if (DECL_HAS_VTT_PARM_P (decl))
1809 spec_types = TREE_CHAIN (spec_types);
1813 /* Compute the merged default arguments. */
1815 copy_default_args_to_explicit_spec_1 (spec_types, tmpl_types);
1817 /* Compute the new FUNCTION_TYPE. */
1821 new_spec_types = hash_tree_cons (TREE_PURPOSE (vtt),
1826 /* Put the in-charge parameter back. */
1827 new_spec_types = hash_tree_cons (TREE_PURPOSE (in_charge),
1828 TREE_VALUE (in_charge),
1831 new_type = build_method_type_directly (object_type,
1832 TREE_TYPE (old_type),
1836 new_type = build_function_type (TREE_TYPE (old_type),
1838 new_type = cp_build_type_attribute_variant (new_type,
1839 TYPE_ATTRIBUTES (old_type));
1840 new_type = build_exception_variant (new_type,
1841 TYPE_RAISES_EXCEPTIONS (old_type));
1842 TREE_TYPE (decl) = new_type;
1845 /* Check to see if the function just declared, as indicated in
1846 DECLARATOR, and in DECL, is a specialization of a function
1847 template. We may also discover that the declaration is an explicit
1848 instantiation at this point.
1850 Returns DECL, or an equivalent declaration that should be used
1851 instead if all goes well. Issues an error message if something is
1852 amiss. Returns error_mark_node if the error is not easily
1855 FLAGS is a bitmask consisting of the following flags:
1857 2: The function has a definition.
1858 4: The function is a friend.
1860 The TEMPLATE_COUNT is the number of references to qualifying
1861 template classes that appeared in the name of the function. For
1864 template <class T> struct S { void f(); };
1867 the TEMPLATE_COUNT would be 1. However, explicitly specialized
1868 classes are not counted in the TEMPLATE_COUNT, so that in
1870 template <class T> struct S {};
1871 template <> struct S<int> { void f(); }
1872 template <> void S<int>::f();
1874 the TEMPLATE_COUNT would be 0. (Note that this declaration is
1875 invalid; there should be no template <>.)
1877 If the function is a specialization, it is marked as such via
1878 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
1879 is set up correctly, and it is added to the list of specializations
1880 for that template. */
1883 check_explicit_specialization (tree declarator,
1888 int have_def = flags & 2;
1889 int is_friend = flags & 4;
1890 int specialization = 0;
1891 int explicit_instantiation = 0;
1892 int member_specialization = 0;
1893 tree ctype = DECL_CLASS_CONTEXT (decl);
1894 tree dname = DECL_NAME (decl);
1899 if (!processing_specialization)
1902 tsk = tsk_excessive_parms;
1905 tsk = current_tmpl_spec_kind (template_count);
1910 if (processing_specialization)
1913 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
1915 else if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
1918 /* This could be something like:
1920 template <class T> void f(T);
1921 class S { friend void f<>(int); } */
1925 /* This case handles bogus declarations like template <>
1926 template <class T> void f<int>(); */
1928 error ("template-id %qD in declaration of primary template",
1935 case tsk_invalid_member_spec:
1936 /* The error has already been reported in
1937 check_specialization_scope. */
1938 return error_mark_node;
1940 case tsk_invalid_expl_inst:
1941 error ("template parameter list used in explicit instantiation");
1947 error ("definition provided for explicit instantiation");
1949 explicit_instantiation = 1;
1952 case tsk_excessive_parms:
1953 case tsk_insufficient_parms:
1954 if (tsk == tsk_excessive_parms)
1955 error ("too many template parameter lists in declaration of %qD",
1957 else if (template_header_count)
1958 error("too few template parameter lists in declaration of %qD", decl);
1960 error("explicit specialization of %qD must be introduced by "
1961 "%<template <>%>", decl);
1965 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
1967 member_specialization = 1;
1973 if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
1975 /* This case handles bogus declarations like template <>
1976 template <class T> void f<int>(); */
1978 if (uses_template_parms (declarator))
1979 error ("function template partial specialization %qD "
1980 "is not allowed", declarator);
1982 error ("template-id %qD in declaration of primary template",
1987 if (ctype && CLASSTYPE_TEMPLATE_INSTANTIATION (ctype))
1988 /* This is a specialization of a member template, without
1989 specialization the containing class. Something like:
1991 template <class T> struct S {
1992 template <class U> void f (U);
1994 template <> template <class U> void S<int>::f(U) {}
1996 That's a specialization -- but of the entire template. */
2004 if (specialization || member_specialization)
2006 tree t = TYPE_ARG_TYPES (TREE_TYPE (decl));
2007 for (; t; t = TREE_CHAIN (t))
2008 if (TREE_PURPOSE (t))
2010 permerror (input_location,
2011 "default argument specified in explicit specialization");
2016 if (specialization || member_specialization || explicit_instantiation)
2018 tree tmpl = NULL_TREE;
2019 tree targs = NULL_TREE;
2021 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2022 if (TREE_CODE (declarator) != TEMPLATE_ID_EXPR)
2026 gcc_assert (TREE_CODE (declarator) == IDENTIFIER_NODE);
2031 /* If there is no class context, the explicit instantiation
2032 must be at namespace scope. */
2033 gcc_assert (DECL_NAMESPACE_SCOPE_P (decl));
2035 /* Find the namespace binding, using the declaration
2037 fns = lookup_qualified_name (CP_DECL_CONTEXT (decl), dname,
2039 if (fns == error_mark_node || !is_overloaded_fn (fns))
2041 error ("%qD is not a template function", dname);
2042 fns = error_mark_node;
2046 tree fn = OVL_CURRENT (fns);
2047 if (!is_associated_namespace (CP_DECL_CONTEXT (decl),
2048 CP_DECL_CONTEXT (fn)))
2049 error ("%qD is not declared in %qD",
2050 decl, current_namespace);
2054 declarator = lookup_template_function (fns, NULL_TREE);
2057 if (declarator == error_mark_node)
2058 return error_mark_node;
2060 if (ctype != NULL_TREE && TYPE_BEING_DEFINED (ctype))
2062 if (!explicit_instantiation)
2063 /* A specialization in class scope. This is invalid,
2064 but the error will already have been flagged by
2065 check_specialization_scope. */
2066 return error_mark_node;
2069 /* It's not valid to write an explicit instantiation in
2072 class C { template void f(); }
2074 This case is caught by the parser. However, on
2077 template class C { void f(); };
2079 (which is invalid) we can get here. The error will be
2086 else if (ctype != NULL_TREE
2087 && (TREE_CODE (TREE_OPERAND (declarator, 0)) ==
2090 /* Find the list of functions in ctype that have the same
2091 name as the declared function. */
2092 tree name = TREE_OPERAND (declarator, 0);
2093 tree fns = NULL_TREE;
2096 if (constructor_name_p (name, ctype))
2098 int is_constructor = DECL_CONSTRUCTOR_P (decl);
2100 if (is_constructor ? !TYPE_HAS_USER_CONSTRUCTOR (ctype)
2101 : !CLASSTYPE_DESTRUCTORS (ctype))
2103 /* From [temp.expl.spec]:
2105 If such an explicit specialization for the member
2106 of a class template names an implicitly-declared
2107 special member function (clause _special_), the
2108 program is ill-formed.
2110 Similar language is found in [temp.explicit]. */
2111 error ("specialization of implicitly-declared special member function");
2112 return error_mark_node;
2115 name = is_constructor ? ctor_identifier : dtor_identifier;
2118 if (!DECL_CONV_FN_P (decl))
2120 idx = lookup_fnfields_1 (ctype, name);
2122 fns = VEC_index (tree, CLASSTYPE_METHOD_VEC (ctype), idx);
2126 VEC(tree,gc) *methods;
2129 /* For a type-conversion operator, we cannot do a
2130 name-based lookup. We might be looking for `operator
2131 int' which will be a specialization of `operator T'.
2132 So, we find *all* the conversion operators, and then
2133 select from them. */
2136 methods = CLASSTYPE_METHOD_VEC (ctype);
2138 for (idx = CLASSTYPE_FIRST_CONVERSION_SLOT;
2139 VEC_iterate (tree, methods, idx, ovl);
2142 if (!DECL_CONV_FN_P (OVL_CURRENT (ovl)))
2143 /* There are no more conversion functions. */
2146 /* Glue all these conversion functions together
2147 with those we already have. */
2148 for (; ovl; ovl = OVL_NEXT (ovl))
2149 fns = ovl_cons (OVL_CURRENT (ovl), fns);
2153 if (fns == NULL_TREE)
2155 error ("no member function %qD declared in %qT", name, ctype);
2156 return error_mark_node;
2159 TREE_OPERAND (declarator, 0) = fns;
2162 /* Figure out what exactly is being specialized at this point.
2163 Note that for an explicit instantiation, even one for a
2164 member function, we cannot tell apriori whether the
2165 instantiation is for a member template, or just a member
2166 function of a template class. Even if a member template is
2167 being instantiated, the member template arguments may be
2168 elided if they can be deduced from the rest of the
2170 tmpl = determine_specialization (declarator, decl,
2172 member_specialization,
2176 if (!tmpl || tmpl == error_mark_node)
2177 /* We couldn't figure out what this declaration was
2179 return error_mark_node;
2182 tree gen_tmpl = most_general_template (tmpl);
2184 if (explicit_instantiation)
2186 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2187 is done by do_decl_instantiation later. */
2189 int arg_depth = TMPL_ARGS_DEPTH (targs);
2190 int parm_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
2192 if (arg_depth > parm_depth)
2194 /* If TMPL is not the most general template (for
2195 example, if TMPL is a friend template that is
2196 injected into namespace scope), then there will
2197 be too many levels of TARGS. Remove some of them
2202 new_targs = make_tree_vec (parm_depth);
2203 for (i = arg_depth - parm_depth; i < arg_depth; ++i)
2204 TREE_VEC_ELT (new_targs, i - (arg_depth - parm_depth))
2205 = TREE_VEC_ELT (targs, i);
2209 return instantiate_template (tmpl, targs, tf_error);
2212 /* If we thought that the DECL was a member function, but it
2213 turns out to be specializing a static member function,
2214 make DECL a static member function as well. */
2215 if (DECL_STATIC_FUNCTION_P (tmpl)
2216 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2217 revert_static_member_fn (decl);
2219 /* If this is a specialization of a member template of a
2220 template class, we want to return the TEMPLATE_DECL, not
2221 the specialization of it. */
2222 if (tsk == tsk_template)
2224 tree result = DECL_TEMPLATE_RESULT (tmpl);
2225 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
2226 DECL_INITIAL (result) = NULL_TREE;
2230 DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl);
2231 DECL_SOURCE_LOCATION (result)
2232 = DECL_SOURCE_LOCATION (decl);
2233 /* We want to use the argument list specified in the
2234 definition, not in the original declaration. */
2235 DECL_ARGUMENTS (result) = DECL_ARGUMENTS (decl);
2236 for (parm = DECL_ARGUMENTS (result); parm;
2237 parm = TREE_CHAIN (parm))
2238 DECL_CONTEXT (parm) = result;
2243 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2244 DECL_TEMPLATE_INFO (decl) = tree_cons (tmpl, targs, NULL_TREE);
2246 /* Inherit default function arguments from the template
2247 DECL is specializing. */
2248 copy_default_args_to_explicit_spec (decl);
2250 /* This specialization has the same protection as the
2251 template it specializes. */
2252 TREE_PRIVATE (decl) = TREE_PRIVATE (gen_tmpl);
2253 TREE_PROTECTED (decl) = TREE_PROTECTED (gen_tmpl);
2255 /* 7.1.1-1 [dcl.stc]
2257 A storage-class-specifier shall not be specified in an
2258 explicit specialization...
2260 The parser rejects these, so unless action is taken here,
2261 explicit function specializations will always appear with
2264 The action recommended by the C++ CWG in response to C++
2265 defect report 605 is to make the storage class and linkage
2266 of the explicit specialization match the templated function:
2268 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2270 if (tsk == tsk_expl_spec && DECL_FUNCTION_TEMPLATE_P (gen_tmpl))
2272 tree tmpl_func = DECL_TEMPLATE_RESULT (gen_tmpl);
2273 gcc_assert (TREE_CODE (tmpl_func) == FUNCTION_DECL);
2275 /* This specialization has the same linkage and visibility as
2276 the function template it specializes. */
2277 TREE_PUBLIC (decl) = TREE_PUBLIC (tmpl_func);
2278 if (! TREE_PUBLIC (decl))
2280 DECL_INTERFACE_KNOWN (decl) = 1;
2281 DECL_NOT_REALLY_EXTERN (decl) = 1;
2283 DECL_THIS_STATIC (decl) = DECL_THIS_STATIC (tmpl_func);
2284 if (DECL_VISIBILITY_SPECIFIED (tmpl_func))
2286 DECL_VISIBILITY_SPECIFIED (decl) = 1;
2287 DECL_VISIBILITY (decl) = DECL_VISIBILITY (tmpl_func);
2291 /* If DECL is a friend declaration, declared using an
2292 unqualified name, the namespace associated with DECL may
2293 have been set incorrectly. For example, in:
2295 template <typename T> void f(T);
2297 struct S { friend void f<int>(int); }
2300 we will have set the DECL_CONTEXT for the friend
2301 declaration to N, rather than to the global namespace. */
2302 if (DECL_NAMESPACE_SCOPE_P (decl))
2303 DECL_CONTEXT (decl) = DECL_CONTEXT (tmpl);
2305 if (is_friend && !have_def)
2306 /* This is not really a declaration of a specialization.
2307 It's just the name of an instantiation. But, it's not
2308 a request for an instantiation, either. */
2309 SET_DECL_IMPLICIT_INSTANTIATION (decl);
2310 else if (DECL_CONSTRUCTOR_P (decl) || DECL_DESTRUCTOR_P (decl))
2311 /* This is indeed a specialization. In case of constructors
2312 and destructors, we need in-charge and not-in-charge
2313 versions in V3 ABI. */
2314 clone_function_decl (decl, /*update_method_vec_p=*/0);
2316 /* Register this specialization so that we can find it
2318 decl = register_specialization (decl, gen_tmpl, targs, is_friend);
2325 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2326 parameters. These are represented in the same format used for
2327 DECL_TEMPLATE_PARMS. */
2330 comp_template_parms (const_tree parms1, const_tree parms2)
2335 if (parms1 == parms2)
2338 for (p1 = parms1, p2 = parms2;
2339 p1 != NULL_TREE && p2 != NULL_TREE;
2340 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2))
2342 tree t1 = TREE_VALUE (p1);
2343 tree t2 = TREE_VALUE (p2);
2346 gcc_assert (TREE_CODE (t1) == TREE_VEC);
2347 gcc_assert (TREE_CODE (t2) == TREE_VEC);
2349 if (TREE_VEC_LENGTH (t1) != TREE_VEC_LENGTH (t2))
2352 for (i = 0; i < TREE_VEC_LENGTH (t2); ++i)
2354 tree parm1 = TREE_VALUE (TREE_VEC_ELT (t1, i));
2355 tree parm2 = TREE_VALUE (TREE_VEC_ELT (t2, i));
2357 /* If either of the template parameters are invalid, assume
2358 they match for the sake of error recovery. */
2359 if (parm1 == error_mark_node || parm2 == error_mark_node)
2362 if (TREE_CODE (parm1) != TREE_CODE (parm2))
2365 if (TREE_CODE (parm1) == TEMPLATE_TYPE_PARM
2366 && (TEMPLATE_TYPE_PARAMETER_PACK (parm1)
2367 == TEMPLATE_TYPE_PARAMETER_PACK (parm2)))
2369 else if (!same_type_p (TREE_TYPE (parm1), TREE_TYPE (parm2)))
2374 if ((p1 != NULL_TREE) != (p2 != NULL_TREE))
2375 /* One set of parameters has more parameters lists than the
2382 /* Determine whether PARM is a parameter pack. */
2384 template_parameter_pack_p (const_tree parm)
2386 /* Determine if we have a non-type template parameter pack. */
2387 if (TREE_CODE (parm) == PARM_DECL)
2388 return (DECL_TEMPLATE_PARM_P (parm)
2389 && TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)));
2391 /* If this is a list of template parameters, we could get a
2392 TYPE_DECL or a TEMPLATE_DECL. */
2393 if (TREE_CODE (parm) == TYPE_DECL || TREE_CODE (parm) == TEMPLATE_DECL)
2394 parm = TREE_TYPE (parm);
2396 return ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
2397 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM)
2398 && TEMPLATE_TYPE_PARAMETER_PACK (parm));
2401 /* Determine whether ARGS describes a variadic template args list,
2402 i.e., one that is terminated by a template argument pack. */
2404 template_args_variadic_p (tree args)
2409 if (args == NULL_TREE)
2412 args = INNERMOST_TEMPLATE_ARGS (args);
2413 nargs = TREE_VEC_LENGTH (args);
2418 last_parm = TREE_VEC_ELT (args, nargs - 1);
2420 return ARGUMENT_PACK_P (last_parm);
2423 /* Generate a new name for the parameter pack name NAME (an
2424 IDENTIFIER_NODE) that incorporates its */
2426 make_ith_pack_parameter_name (tree name, int i)
2428 /* Munge the name to include the parameter index. */
2432 sprintf(numbuf, "%i", i);
2433 newname = (char*)alloca (IDENTIFIER_LENGTH (name) + strlen(numbuf) + 2);
2434 sprintf(newname, "%s#%i", IDENTIFIER_POINTER (name), i);
2435 return get_identifier (newname);
2438 /* Structure used to track the progress of find_parameter_packs_r. */
2439 struct find_parameter_pack_data
2441 /* TREE_LIST that will contain all of the parameter packs found by
2443 tree* parameter_packs;
2445 /* Set of AST nodes that have been visited by the traversal. */
2446 struct pointer_set_t *visited;
2449 /* Identifies all of the argument packs that occur in a template
2450 argument and appends them to the TREE_LIST inside DATA, which is a
2451 find_parameter_pack_data structure. This is a subroutine of
2452 make_pack_expansion and uses_parameter_packs. */
2454 find_parameter_packs_r (tree *tp, int *walk_subtrees, void* data)
2457 struct find_parameter_pack_data* ppd =
2458 (struct find_parameter_pack_data*)data;
2459 bool parameter_pack_p = false;
2461 /* Identify whether this is a parameter pack or not. */
2462 switch (TREE_CODE (t))
2464 case TEMPLATE_PARM_INDEX:
2465 if (TEMPLATE_PARM_PARAMETER_PACK (t))
2466 parameter_pack_p = true;
2469 case TEMPLATE_TYPE_PARM:
2470 case TEMPLATE_TEMPLATE_PARM:
2471 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
2472 parameter_pack_p = true;
2476 if (FUNCTION_PARAMETER_PACK_P (t))
2478 /* We don't want to walk into the type of a PARM_DECL,
2479 because we don't want to see the type parameter pack. */
2481 parameter_pack_p = true;
2486 /* Not a parameter pack. */
2490 if (parameter_pack_p)
2492 /* Add this parameter pack to the list. */
2493 *ppd->parameter_packs = tree_cons (NULL_TREE, t, *ppd->parameter_packs);
2497 cp_walk_tree (&TYPE_CONTEXT (t),
2498 &find_parameter_packs_r, ppd, ppd->visited);
2500 /* This switch statement will return immediately if we don't find a
2502 switch (TREE_CODE (t))
2504 case TEMPLATE_PARM_INDEX:
2507 case BOUND_TEMPLATE_TEMPLATE_PARM:
2508 /* Check the template itself. */
2509 cp_walk_tree (&TREE_TYPE (TYPE_TI_TEMPLATE (t)),
2510 &find_parameter_packs_r, ppd, ppd->visited);
2511 /* Check the template arguments. */
2512 cp_walk_tree (&TYPE_TI_ARGS (t), &find_parameter_packs_r, ppd,
2517 case TEMPLATE_TYPE_PARM:
2518 case TEMPLATE_TEMPLATE_PARM:
2525 if (TYPE_PTRMEMFUNC_P (t))
2531 if (TYPE_TEMPLATE_INFO (t))
2532 cp_walk_tree (&TREE_VALUE (TYPE_TEMPLATE_INFO (t)),
2533 &find_parameter_packs_r, ppd, ppd->visited);
2539 cp_walk_tree (&TREE_TYPE (t),
2540 &find_parameter_packs_r, ppd, ppd->visited);
2544 cp_walk_tree (&TYPENAME_TYPE_FULLNAME (t), &find_parameter_packs_r,
2549 case TYPE_PACK_EXPANSION:
2550 case EXPR_PACK_EXPANSION:
2555 cp_walk_tree (&TYPE_MAX_VALUE (t), &find_parameter_packs_r,
2560 case IDENTIFIER_NODE:
2561 cp_walk_tree (&TREE_TYPE (t), &find_parameter_packs_r, ppd,
2573 /* Determines if the expression or type T uses any parameter packs. */
2575 uses_parameter_packs (tree t)
2577 tree parameter_packs = NULL_TREE;
2578 struct find_parameter_pack_data ppd;
2579 ppd.parameter_packs = ¶meter_packs;
2580 ppd.visited = pointer_set_create ();
2581 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
2582 pointer_set_destroy (ppd.visited);
2583 return parameter_packs != NULL_TREE;
2586 /* Turn ARG, which may be an expression, type, or a TREE_LIST
2587 representation a base-class initializer into a parameter pack
2588 expansion. If all goes well, the resulting node will be an
2589 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
2592 make_pack_expansion (tree arg)
2595 tree parameter_packs = NULL_TREE;
2596 bool for_types = false;
2597 struct find_parameter_pack_data ppd;
2599 if (!arg || arg == error_mark_node)
2602 if (TREE_CODE (arg) == TREE_LIST)
2604 /* The only time we will see a TREE_LIST here is for a base
2605 class initializer. In this case, the TREE_PURPOSE will be a
2606 _TYPE node (representing the base class expansion we're
2607 initializing) and the TREE_VALUE will be a TREE_LIST
2608 containing the initialization arguments.
2610 The resulting expansion looks somewhat different from most
2611 expansions. Rather than returning just one _EXPANSION, we
2612 return a TREE_LIST whose TREE_PURPOSE is a
2613 TYPE_PACK_EXPANSION containing the bases that will be
2614 initialized. The TREE_VALUE will be identical to the
2615 original TREE_VALUE, which is a list of arguments that will
2616 be passed to each base. We do not introduce any new pack
2617 expansion nodes into the TREE_VALUE (although it is possible
2618 that some already exist), because the TREE_PURPOSE and
2619 TREE_VALUE all need to be expanded together with the same
2620 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
2621 resulting TREE_PURPOSE will mention the parameter packs in
2622 both the bases and the arguments to the bases. */
2625 tree parameter_packs = NULL_TREE;
2627 /* Determine which parameter packs will be used by the base
2629 ppd.visited = pointer_set_create ();
2630 ppd.parameter_packs = ¶meter_packs;
2631 cp_walk_tree (&TREE_PURPOSE (arg), &find_parameter_packs_r,
2634 if (parameter_packs == NULL_TREE)
2636 error ("base initializer expansion %<%T%> contains no parameter packs", arg);
2637 pointer_set_destroy (ppd.visited);
2638 return error_mark_node;
2641 if (TREE_VALUE (arg) != void_type_node)
2643 /* Collect the sets of parameter packs used in each of the
2644 initialization arguments. */
2645 for (value = TREE_VALUE (arg); value; value = TREE_CHAIN (value))
2647 /* Determine which parameter packs will be expanded in this
2649 cp_walk_tree (&TREE_VALUE (value), &find_parameter_packs_r,
2654 pointer_set_destroy (ppd.visited);
2656 /* Create the pack expansion type for the base type. */
2657 purpose = make_node (TYPE_PACK_EXPANSION);
2658 SET_PACK_EXPANSION_PATTERN (purpose, TREE_PURPOSE (arg));
2659 PACK_EXPANSION_PARAMETER_PACKS (purpose) = parameter_packs;
2661 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
2662 they will rarely be compared to anything. */
2663 SET_TYPE_STRUCTURAL_EQUALITY (purpose);
2665 return tree_cons (purpose, TREE_VALUE (arg), NULL_TREE);
2668 if (TYPE_P (arg) || TREE_CODE (arg) == TEMPLATE_DECL)
2671 /* Build the PACK_EXPANSION_* node. */
2672 result = make_node (for_types ? TYPE_PACK_EXPANSION : EXPR_PACK_EXPANSION);
2673 SET_PACK_EXPANSION_PATTERN (result, arg);
2674 if (TREE_CODE (result) == EXPR_PACK_EXPANSION)
2676 /* Propagate type and const-expression information. */
2677 TREE_TYPE (result) = TREE_TYPE (arg);
2678 TREE_CONSTANT (result) = TREE_CONSTANT (arg);
2681 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
2682 they will rarely be compared to anything. */
2683 SET_TYPE_STRUCTURAL_EQUALITY (result);
2685 /* Determine which parameter packs will be expanded. */
2686 ppd.parameter_packs = ¶meter_packs;
2687 ppd.visited = pointer_set_create ();
2688 cp_walk_tree (&arg, &find_parameter_packs_r, &ppd, ppd.visited);
2689 pointer_set_destroy (ppd.visited);
2691 /* Make sure we found some parameter packs. */
2692 if (parameter_packs == NULL_TREE)
2695 error ("expansion pattern %<%T%> contains no argument packs", arg);
2697 error ("expansion pattern %<%E%> contains no argument packs", arg);
2698 return error_mark_node;
2700 PACK_EXPANSION_PARAMETER_PACKS (result) = parameter_packs;
2705 /* Checks T for any "bare" parameter packs, which have not yet been
2706 expanded, and issues an error if any are found. This operation can
2707 only be done on full expressions or types (e.g., an expression
2708 statement, "if" condition, etc.), because we could have expressions like:
2710 foo(f(g(h(args)))...)
2712 where "args" is a parameter pack. check_for_bare_parameter_packs
2713 should not be called for the subexpressions args, h(args),
2714 g(h(args)), or f(g(h(args))), because we would produce erroneous
2717 Returns TRUE and emits an error if there were bare parameter packs,
2718 returns FALSE otherwise. */
2720 check_for_bare_parameter_packs (tree t)
2722 tree parameter_packs = NULL_TREE;
2723 struct find_parameter_pack_data ppd;
2725 if (!processing_template_decl || !t || t == error_mark_node)
2728 if (TREE_CODE (t) == TYPE_DECL)
2731 ppd.parameter_packs = ¶meter_packs;
2732 ppd.visited = pointer_set_create ();
2733 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
2734 pointer_set_destroy (ppd.visited);
2736 if (parameter_packs)
2738 error ("parameter packs not expanded with %<...%>:");
2739 while (parameter_packs)
2741 tree pack = TREE_VALUE (parameter_packs);
2742 tree name = NULL_TREE;
2744 if (TREE_CODE (pack) == TEMPLATE_TYPE_PARM
2745 || TREE_CODE (pack) == TEMPLATE_TEMPLATE_PARM)
2746 name = TYPE_NAME (pack);
2747 else if (TREE_CODE (pack) == TEMPLATE_PARM_INDEX)
2748 name = DECL_NAME (TEMPLATE_PARM_DECL (pack));
2750 name = DECL_NAME (pack);
2753 inform (input_location, " %qD", name);
2755 inform (input_location, " <anonymous>");
2757 parameter_packs = TREE_CHAIN (parameter_packs);
2766 /* Expand any parameter packs that occur in the template arguments in
2769 expand_template_argument_pack (tree args)
2771 tree result_args = NULL_TREE;
2772 int in_arg, out_arg = 0, nargs = args ? TREE_VEC_LENGTH (args) : 0;
2773 int num_result_args = -1;
2775 /* First, determine if we need to expand anything, and the number of
2776 slots we'll need. */
2777 for (in_arg = 0; in_arg < nargs; ++in_arg)
2779 tree arg = TREE_VEC_ELT (args, in_arg);
2780 if (ARGUMENT_PACK_P (arg))
2782 int num_packed = TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg));
2783 if (num_result_args < 0)
2784 num_result_args = in_arg + num_packed;
2786 num_result_args += num_packed;
2790 if (num_result_args >= 0)
2795 /* If no expansion is necessary, we're done. */
2796 if (num_result_args < 0)
2799 /* Expand arguments. */
2800 result_args = make_tree_vec (num_result_args);
2801 for (in_arg = 0; in_arg < nargs; ++in_arg)
2803 tree arg = TREE_VEC_ELT (args, in_arg);
2804 if (ARGUMENT_PACK_P (arg))
2806 tree packed = ARGUMENT_PACK_ARGS (arg);
2807 int i, num_packed = TREE_VEC_LENGTH (packed);
2808 for (i = 0; i < num_packed; ++i, ++out_arg)
2809 TREE_VEC_ELT (result_args, out_arg) = TREE_VEC_ELT(packed, i);
2813 TREE_VEC_ELT (result_args, out_arg) = arg;
2821 /* Checks if DECL shadows a template parameter.
2823 [temp.local]: A template-parameter shall not be redeclared within its
2824 scope (including nested scopes).
2826 Emits an error and returns TRUE if the DECL shadows a parameter,
2827 returns FALSE otherwise. */
2830 check_template_shadow (tree decl)
2834 /* If we're not in a template, we can't possibly shadow a template
2836 if (!current_template_parms)
2839 /* Figure out what we're shadowing. */
2840 if (TREE_CODE (decl) == OVERLOAD)
2841 decl = OVL_CURRENT (decl);
2842 olddecl = innermost_non_namespace_value (DECL_NAME (decl));
2844 /* If there's no previous binding for this name, we're not shadowing
2845 anything, let alone a template parameter. */
2849 /* If we're not shadowing a template parameter, we're done. Note
2850 that OLDDECL might be an OVERLOAD (or perhaps even an
2851 ERROR_MARK), so we can't just blithely assume it to be a _DECL
2853 if (!DECL_P (olddecl) || !DECL_TEMPLATE_PARM_P (olddecl))
2856 /* We check for decl != olddecl to avoid bogus errors for using a
2857 name inside a class. We check TPFI to avoid duplicate errors for
2858 inline member templates. */
2860 || TEMPLATE_PARMS_FOR_INLINE (current_template_parms))
2863 error ("declaration of %q+#D", decl);
2864 error (" shadows template parm %q+#D", olddecl);
2868 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
2869 ORIG_LEVEL, DECL, and TYPE. */
2872 build_template_parm_index (int index,
2878 tree t = make_node (TEMPLATE_PARM_INDEX);
2879 TEMPLATE_PARM_IDX (t) = index;
2880 TEMPLATE_PARM_LEVEL (t) = level;
2881 TEMPLATE_PARM_ORIG_LEVEL (t) = orig_level;
2882 TEMPLATE_PARM_DECL (t) = decl;
2883 TREE_TYPE (t) = type;
2884 TREE_CONSTANT (t) = TREE_CONSTANT (decl);
2885 TREE_READONLY (t) = TREE_READONLY (decl);
2890 /* Find the canonical type parameter for the given template type
2891 parameter. Returns the canonical type parameter, which may be TYPE
2892 if no such parameter existed. */
2894 canonical_type_parameter (tree type)
2897 int idx = TEMPLATE_TYPE_IDX (type);
2898 if (!canonical_template_parms)
2899 canonical_template_parms = VEC_alloc (tree, gc, idx+1);
2901 while (VEC_length (tree, canonical_template_parms) <= (unsigned)idx)
2902 VEC_safe_push (tree, gc, canonical_template_parms, NULL_TREE);
2904 list = VEC_index (tree, canonical_template_parms, idx);
2905 while (list && !comptypes (type, TREE_VALUE (list), COMPARE_STRUCTURAL))
2906 list = TREE_CHAIN (list);
2909 return TREE_VALUE (list);
2912 VEC_replace(tree, canonical_template_parms, idx,
2913 tree_cons (NULL_TREE, type,
2914 VEC_index (tree, canonical_template_parms, idx)));
2919 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
2920 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
2921 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
2922 new one is created. */
2925 reduce_template_parm_level (tree index, tree type, int levels, tree args,
2926 tsubst_flags_t complain)
2928 if (TEMPLATE_PARM_DESCENDANTS (index) == NULL_TREE
2929 || (TEMPLATE_PARM_LEVEL (TEMPLATE_PARM_DESCENDANTS (index))
2930 != TEMPLATE_PARM_LEVEL (index) - levels))
2932 tree orig_decl = TEMPLATE_PARM_DECL (index);
2935 decl = build_decl (DECL_SOURCE_LOCATION (orig_decl),
2936 TREE_CODE (orig_decl), DECL_NAME (orig_decl), type);
2937 TREE_CONSTANT (decl) = TREE_CONSTANT (orig_decl);
2938 TREE_READONLY (decl) = TREE_READONLY (orig_decl);
2939 DECL_ARTIFICIAL (decl) = 1;
2940 SET_DECL_TEMPLATE_PARM_P (decl);
2942 t = build_template_parm_index (TEMPLATE_PARM_IDX (index),
2943 TEMPLATE_PARM_LEVEL (index) - levels,
2944 TEMPLATE_PARM_ORIG_LEVEL (index),
2946 TEMPLATE_PARM_DESCENDANTS (index) = t;
2947 TEMPLATE_PARM_PARAMETER_PACK (t)
2948 = TEMPLATE_PARM_PARAMETER_PACK (index);
2950 /* Template template parameters need this. */
2951 if (TREE_CODE (decl) == TEMPLATE_DECL)
2952 DECL_TEMPLATE_PARMS (decl) = tsubst_template_parms
2953 (DECL_TEMPLATE_PARMS (TEMPLATE_PARM_DECL (index)),
2957 return TEMPLATE_PARM_DESCENDANTS (index);
2960 /* Process information from new template parameter PARM and append it to the
2961 LIST being built. This new parameter is a non-type parameter iff
2962 IS_NON_TYPE is true. This new parameter is a parameter
2963 pack iff IS_PARAMETER_PACK is true. The location of PARM is in
2967 process_template_parm (tree list, location_t parm_loc, tree parm, bool is_non_type,
2968 bool is_parameter_pack)
2975 gcc_assert (TREE_CODE (parm) == TREE_LIST);
2976 defval = TREE_PURPOSE (parm);
2980 tree p = tree_last (list);
2982 if (p && TREE_VALUE (p) != error_mark_node)
2985 if (TREE_CODE (p) == TYPE_DECL || TREE_CODE (p) == TEMPLATE_DECL)
2986 idx = TEMPLATE_TYPE_IDX (TREE_TYPE (p));
2988 idx = TEMPLATE_PARM_IDX (DECL_INITIAL (p));
2998 parm = TREE_VALUE (parm);
3000 SET_DECL_TEMPLATE_PARM_P (parm);
3002 if (TREE_TYPE (parm) == error_mark_node)
3004 err_parm_list = build_tree_list (defval, parm);
3005 TREE_VALUE (err_parm_list) = error_mark_node;
3006 return chainon (list, err_parm_list);
3012 The top-level cv-qualifiers on the template-parameter are
3013 ignored when determining its type. */
3014 TREE_TYPE (parm) = TYPE_MAIN_VARIANT (TREE_TYPE (parm));
3015 if (invalid_nontype_parm_type_p (TREE_TYPE (parm), 1))
3017 err_parm_list = build_tree_list (defval, parm);
3018 TREE_VALUE (err_parm_list) = error_mark_node;
3019 return chainon (list, err_parm_list);
3022 if (uses_parameter_packs (TREE_TYPE (parm)) && !is_parameter_pack)
3024 /* This template parameter is not a parameter pack, but it
3025 should be. Complain about "bare" parameter packs. */
3026 check_for_bare_parameter_packs (TREE_TYPE (parm));
3028 /* Recover by calling this a parameter pack. */
3029 is_parameter_pack = true;
3033 /* A template parameter is not modifiable. */
3034 TREE_CONSTANT (parm) = 1;
3035 TREE_READONLY (parm) = 1;
3036 decl = build_decl (parm_loc,
3037 CONST_DECL, DECL_NAME (parm), TREE_TYPE (parm));
3038 TREE_CONSTANT (decl) = 1;
3039 TREE_READONLY (decl) = 1;
3040 DECL_INITIAL (parm) = DECL_INITIAL (decl)
3041 = build_template_parm_index (idx, processing_template_decl,
3042 processing_template_decl,
3043 decl, TREE_TYPE (parm));
3045 TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))
3046 = is_parameter_pack;
3051 parm = TREE_VALUE (TREE_VALUE (parm));
3053 if (parm && TREE_CODE (parm) == TEMPLATE_DECL)
3055 t = cxx_make_type (TEMPLATE_TEMPLATE_PARM);
3056 /* This is for distinguishing between real templates and template
3057 template parameters */
3058 TREE_TYPE (parm) = t;
3059 TREE_TYPE (DECL_TEMPLATE_RESULT (parm)) = t;
3064 t = cxx_make_type (TEMPLATE_TYPE_PARM);
3065 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3066 decl = build_decl (parm_loc,
3067 TYPE_DECL, parm, t);
3070 TYPE_NAME (t) = decl;
3071 TYPE_STUB_DECL (t) = decl;
3073 TEMPLATE_TYPE_PARM_INDEX (t)
3074 = build_template_parm_index (idx, processing_template_decl,
3075 processing_template_decl,
3076 decl, TREE_TYPE (parm));
3077 TEMPLATE_TYPE_PARAMETER_PACK (t) = is_parameter_pack;
3078 TYPE_CANONICAL (t) = canonical_type_parameter (t);
3080 DECL_ARTIFICIAL (decl) = 1;
3081 SET_DECL_TEMPLATE_PARM_P (decl);
3083 parm = build_tree_list (defval, parm);
3084 return chainon (list, parm);
3087 /* The end of a template parameter list has been reached. Process the
3088 tree list into a parameter vector, converting each parameter into a more
3089 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3093 end_template_parm_list (tree parms)
3097 tree saved_parmlist = make_tree_vec (list_length (parms));
3099 current_template_parms
3100 = tree_cons (size_int (processing_template_decl),
3101 saved_parmlist, current_template_parms);
3103 for (parm = parms, nparms = 0; parm; parm = next, nparms++)
3105 next = TREE_CHAIN (parm);
3106 TREE_VEC_ELT (saved_parmlist, nparms) = parm;
3107 TREE_CHAIN (parm) = NULL_TREE;
3110 --processing_template_parmlist;
3112 return saved_parmlist;
3115 /* end_template_decl is called after a template declaration is seen. */
3118 end_template_decl (void)
3120 reset_specialization ();
3122 if (! processing_template_decl)
3125 /* This matches the pushlevel in begin_template_parm_list. */
3128 --processing_template_decl;
3129 current_template_parms = TREE_CHAIN (current_template_parms);
3132 /* Within the declaration of a template, return all levels of template
3133 parameters that apply. The template parameters are represented as
3134 a TREE_VEC, in the form documented in cp-tree.h for template
3138 current_template_args (void)
3141 tree args = NULL_TREE;
3142 int length = TMPL_PARMS_DEPTH (current_template_parms);
3145 /* If there is only one level of template parameters, we do not
3146 create a TREE_VEC of TREE_VECs. Instead, we return a single
3147 TREE_VEC containing the arguments. */
3149 args = make_tree_vec (length);
3151 for (header = current_template_parms; header; header = TREE_CHAIN (header))
3153 tree a = copy_node (TREE_VALUE (header));
3156 TREE_TYPE (a) = NULL_TREE;
3157 for (i = TREE_VEC_LENGTH (a) - 1; i >= 0; --i)
3159 tree t = TREE_VEC_ELT (a, i);
3161 /* T will be a list if we are called from within a
3162 begin/end_template_parm_list pair, but a vector directly
3163 if within a begin/end_member_template_processing pair. */
3164 if (TREE_CODE (t) == TREE_LIST)
3168 if (!error_operand_p (t))
3170 if (TREE_CODE (t) == TYPE_DECL
3171 || TREE_CODE (t) == TEMPLATE_DECL)
3175 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
3177 /* Turn this argument into a TYPE_ARGUMENT_PACK
3178 with a single element, which expands T. */
3179 tree vec = make_tree_vec (1);
3180 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
3182 t = make_node (TYPE_ARGUMENT_PACK);
3183 SET_ARGUMENT_PACK_ARGS (t, vec);
3188 t = DECL_INITIAL (t);
3190 if (TEMPLATE_PARM_PARAMETER_PACK (t))
3192 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3193 with a single element, which expands T. */
3194 tree vec = make_tree_vec (1);
3195 tree type = TREE_TYPE (TEMPLATE_PARM_DECL (t));
3196 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
3198 t = make_node (NONTYPE_ARGUMENT_PACK);
3199 SET_ARGUMENT_PACK_ARGS (t, vec);
3200 TREE_TYPE (t) = type;
3203 TREE_VEC_ELT (a, i) = t;
3209 TREE_VEC_ELT (args, --l) = a;
3217 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
3218 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
3219 a member template. Used by push_template_decl below. */
3222 build_template_decl (tree decl, tree parms, bool member_template_p)
3224 tree tmpl = build_lang_decl (TEMPLATE_DECL, DECL_NAME (decl), NULL_TREE);
3225 DECL_TEMPLATE_PARMS (tmpl) = parms;
3226 DECL_CONTEXT (tmpl) = DECL_CONTEXT (decl);
3227 DECL_MEMBER_TEMPLATE_P (tmpl) = member_template_p;
3228 if (DECL_LANG_SPECIFIC (decl))
3230 DECL_STATIC_FUNCTION_P (tmpl) = DECL_STATIC_FUNCTION_P (decl);
3231 DECL_CONSTRUCTOR_P (tmpl) = DECL_CONSTRUCTOR_P (decl);
3232 DECL_DESTRUCTOR_P (tmpl) = DECL_DESTRUCTOR_P (decl);
3233 DECL_NONCONVERTING_P (tmpl) = DECL_NONCONVERTING_P (decl);
3234 DECL_ASSIGNMENT_OPERATOR_P (tmpl) = DECL_ASSIGNMENT_OPERATOR_P (decl);
3235 if (DECL_OVERLOADED_OPERATOR_P (decl))
3236 SET_OVERLOADED_OPERATOR_CODE (tmpl,
3237 DECL_OVERLOADED_OPERATOR_P (decl));
3243 struct template_parm_data
3245 /* The level of the template parameters we are currently
3249 /* The index of the specialization argument we are currently
3253 /* An array whose size is the number of template parameters. The
3254 elements are nonzero if the parameter has been used in any one
3255 of the arguments processed so far. */
3258 /* An array whose size is the number of template arguments. The
3259 elements are nonzero if the argument makes use of template
3260 parameters of this level. */
3261 int* arg_uses_template_parms;
3264 /* Subroutine of push_template_decl used to see if each template
3265 parameter in a partial specialization is used in the explicit
3266 argument list. If T is of the LEVEL given in DATA (which is
3267 treated as a template_parm_data*), then DATA->PARMS is marked
3271 mark_template_parm (tree t, void* data)
3275 struct template_parm_data* tpd = (struct template_parm_data*) data;
3277 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
3279 level = TEMPLATE_PARM_LEVEL (t);
3280 idx = TEMPLATE_PARM_IDX (t);
3284 level = TEMPLATE_TYPE_LEVEL (t);
3285 idx = TEMPLATE_TYPE_IDX (t);
3288 if (level == tpd->level)
3290 tpd->parms[idx] = 1;
3291 tpd->arg_uses_template_parms[tpd->current_arg] = 1;
3294 /* Return zero so that for_each_template_parm will continue the
3295 traversal of the tree; we want to mark *every* template parm. */
3299 /* Process the partial specialization DECL. */
3302 process_partial_specialization (tree decl)
3304 tree type = TREE_TYPE (decl);
3305 tree maintmpl = CLASSTYPE_TI_TEMPLATE (type);
3306 tree specargs = CLASSTYPE_TI_ARGS (type);
3307 tree inner_args = INNERMOST_TEMPLATE_ARGS (specargs);
3308 tree main_inner_parms = DECL_INNERMOST_TEMPLATE_PARMS (maintmpl);
3310 int nargs = TREE_VEC_LENGTH (inner_args);
3313 int did_error_intro = 0;
3314 struct template_parm_data tpd;
3315 struct template_parm_data tpd2;
3317 gcc_assert (current_template_parms);
3319 inner_parms = INNERMOST_TEMPLATE_PARMS (current_template_parms);
3320 ntparms = TREE_VEC_LENGTH (inner_parms);
3322 /* We check that each of the template parameters given in the
3323 partial specialization is used in the argument list to the
3324 specialization. For example:
3326 template <class T> struct S;
3327 template <class T> struct S<T*>;
3329 The second declaration is OK because `T*' uses the template
3330 parameter T, whereas
3332 template <class T> struct S<int>;
3334 is no good. Even trickier is:
3345 The S2<T> declaration is actually invalid; it is a
3346 full-specialization. Of course,
3349 struct S2<T (*)(U)>;
3351 or some such would have been OK. */
3352 tpd.level = TMPL_PARMS_DEPTH (current_template_parms);
3353 tpd.parms = (int *) alloca (sizeof (int) * ntparms);
3354 memset (tpd.parms, 0, sizeof (int) * ntparms);
3356 tpd.arg_uses_template_parms = (int *) alloca (sizeof (int) * nargs);
3357 memset (tpd.arg_uses_template_parms, 0, sizeof (int) * nargs);
3358 for (i = 0; i < nargs; ++i)
3360 tpd.current_arg = i;
3361 for_each_template_parm (TREE_VEC_ELT (inner_args, i),
3362 &mark_template_parm,
3365 /*include_nondeduced_p=*/false);
3367 for (i = 0; i < ntparms; ++i)
3368 if (tpd.parms[i] == 0)
3370 /* One of the template parms was not used in the
3372 if (!did_error_intro)
3374 error ("template parameters not used in partial specialization:");
3375 did_error_intro = 1;
3378 error (" %qD", TREE_VALUE (TREE_VEC_ELT (inner_parms, i)));
3381 /* [temp.class.spec]
3383 The argument list of the specialization shall not be identical to
3384 the implicit argument list of the primary template. */
3385 if (comp_template_args
3387 INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE
3389 error ("partial specialization %qT does not specialize any template arguments", type);
3391 /* [temp.class.spec]
3393 A partially specialized non-type argument expression shall not
3394 involve template parameters of the partial specialization except
3395 when the argument expression is a simple identifier.
3397 The type of a template parameter corresponding to a specialized
3398 non-type argument shall not be dependent on a parameter of the
3401 Also, we verify that pack expansions only occur at the
3402 end of the argument list. */
3403 gcc_assert (nargs == DECL_NTPARMS (maintmpl));
3405 for (i = 0; i < nargs; ++i)
3407 tree parm = TREE_VALUE (TREE_VEC_ELT (main_inner_parms, i));
3408 tree arg = TREE_VEC_ELT (inner_args, i);
3409 tree packed_args = NULL_TREE;
3412 if (ARGUMENT_PACK_P (arg))
3414 /* Extract the arguments from the argument pack. We'll be
3415 iterating over these in the following loop. */
3416 packed_args = ARGUMENT_PACK_ARGS (arg);
3417 len = TREE_VEC_LENGTH (packed_args);
3420 for (j = 0; j < len; j++)
3423 /* Get the Jth argument in the parameter pack. */
3424 arg = TREE_VEC_ELT (packed_args, j);
3426 if (PACK_EXPANSION_P (arg))
3428 /* Pack expansions must come at the end of the
3430 if ((packed_args && j < len - 1)
3431 || (!packed_args && i < nargs - 1))
3433 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
3434 error ("parameter pack argument %qE must be at the end of the template argument list", arg);
3436 error ("parameter pack argument %qT must be at the end of the template argument list", arg);
3439 TREE_VEC_ELT (packed_args, j) = error_mark_node;
3443 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
3444 /* We only care about the pattern. */
3445 arg = PACK_EXPANSION_PATTERN (arg);
3447 if (/* These first two lines are the `non-type' bit. */
3449 && TREE_CODE (arg) != TEMPLATE_DECL
3450 /* This next line is the `argument expression is not just a
3451 simple identifier' condition and also the `specialized
3452 non-type argument' bit. */
3453 && TREE_CODE (arg) != TEMPLATE_PARM_INDEX)
3455 if ((!packed_args && tpd.arg_uses_template_parms[i])
3456 || (packed_args && uses_template_parms (arg)))
3457 error ("template argument %qE involves template parameter(s)",
3461 /* Look at the corresponding template parameter,
3462 marking which template parameters its type depends
3464 tree type = TREE_TYPE (parm);
3468 /* We haven't yet initialized TPD2. Do so now. */
3469 tpd2.arg_uses_template_parms
3470 = (int *) alloca (sizeof (int) * nargs);
3471 /* The number of parameters here is the number in the
3472 main template, which, as checked in the assertion
3474 tpd2.parms = (int *) alloca (sizeof (int) * nargs);
3476 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (maintmpl));
3479 /* Mark the template parameters. But this time, we're
3480 looking for the template parameters of the main
3481 template, not in the specialization. */
3482 tpd2.current_arg = i;
3483 tpd2.arg_uses_template_parms[i] = 0;
3484 memset (tpd2.parms, 0, sizeof (int) * nargs);
3485 for_each_template_parm (type,
3486 &mark_template_parm,
3489 /*include_nondeduced_p=*/false);
3491 if (tpd2.arg_uses_template_parms [i])
3493 /* The type depended on some template parameters.
3494 If they are fully specialized in the
3495 specialization, that's OK. */
3497 for (j = 0; j < nargs; ++j)
3498 if (tpd2.parms[j] != 0
3499 && tpd.arg_uses_template_parms [j])
3501 error ("type %qT of template argument %qE depends "
3502 "on template parameter(s)",
3513 if (retrieve_specialization (maintmpl, specargs,
3514 /*class_specializations_p=*/true))
3515 /* We've already got this specialization. */
3518 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)
3519 = tree_cons (specargs, inner_parms,
3520 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl));
3521 TREE_TYPE (DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)) = type;
3525 /* Check that a template declaration's use of default arguments and
3526 parameter packs is not invalid. Here, PARMS are the template
3527 parameters. IS_PRIMARY is nonzero if DECL is the thing declared by
3528 a primary template. IS_PARTIAL is nonzero if DECL is a partial
3532 IS_FRIEND_DECL is nonzero if DECL is a friend function template
3533 declaration (but not a definition); 1 indicates a declaration, 2
3534 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
3535 emitted for extraneous default arguments.
3537 Returns TRUE if there were no errors found, FALSE otherwise. */
3540 check_default_tmpl_args (tree decl, tree parms, int is_primary,
3541 int is_partial, int is_friend_decl)
3544 int last_level_to_check;
3546 bool no_errors = true;
3550 A default template-argument shall not be specified in a
3551 function template declaration or a function template definition, nor
3552 in the template-parameter-list of the definition of a member of a
3555 if (TREE_CODE (CP_DECL_CONTEXT (decl)) == FUNCTION_DECL)
3556 /* You can't have a function template declaration in a local
3557 scope, nor you can you define a member of a class template in a
3561 if (current_class_type
3562 && !TYPE_BEING_DEFINED (current_class_type)
3563 && DECL_LANG_SPECIFIC (decl)
3564 /* If this is either a friend defined in the scope of the class
3565 or a member function. */
3566 && (DECL_FUNCTION_MEMBER_P (decl)
3567 ? same_type_p (DECL_CONTEXT (decl), current_class_type)
3568 : DECL_FRIEND_CONTEXT (decl)
3569 ? same_type_p (DECL_FRIEND_CONTEXT (decl), current_class_type)
3571 /* And, if it was a member function, it really was defined in
3572 the scope of the class. */
3573 && (!DECL_FUNCTION_MEMBER_P (decl)
3574 || DECL_INITIALIZED_IN_CLASS_P (decl)))
3575 /* We already checked these parameters when the template was
3576 declared, so there's no need to do it again now. This function
3577 was defined in class scope, but we're processing it's body now
3578 that the class is complete. */
3581 /* Core issue 226 (C++0x only): the following only applies to class
3583 if ((cxx_dialect == cxx98) || TREE_CODE (decl) != FUNCTION_DECL)
3587 If a template-parameter has a default template-argument, all
3588 subsequent template-parameters shall have a default
3589 template-argument supplied. */
3590 for (parm_level = parms; parm_level; parm_level = TREE_CHAIN (parm_level))
3592 tree inner_parms = TREE_VALUE (parm_level);
3593 int ntparms = TREE_VEC_LENGTH (inner_parms);
3594 int seen_def_arg_p = 0;
3597 for (i = 0; i < ntparms; ++i)
3599 tree parm = TREE_VEC_ELT (inner_parms, i);
3601 if (parm == error_mark_node)
3604 if (TREE_PURPOSE (parm))
3606 else if (seen_def_arg_p
3607 && !template_parameter_pack_p (TREE_VALUE (parm)))
3609 error ("no default argument for %qD", TREE_VALUE (parm));
3610 /* For better subsequent error-recovery, we indicate that
3611 there should have been a default argument. */
3612 TREE_PURPOSE (parm) = error_mark_node;
3618 /* Don't complain about an enclosing partial
3620 && parm_level == parms
3621 && TREE_CODE (decl) == TYPE_DECL
3623 && template_parameter_pack_p (TREE_VALUE (parm)))
3625 /* A primary class template can only have one
3626 parameter pack, at the end of the template
3629 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL)
3630 error ("parameter pack %qE must be at the end of the"
3631 " template parameter list", TREE_VALUE (parm));
3633 error ("parameter pack %qT must be at the end of the"
3634 " template parameter list",
3635 TREE_TYPE (TREE_VALUE (parm)));
3637 TREE_VALUE (TREE_VEC_ELT (inner_parms, i))
3645 if (((cxx_dialect == cxx98) && TREE_CODE (decl) != TYPE_DECL)
3649 /* For an ordinary class template, default template arguments are
3650 allowed at the innermost level, e.g.:
3651 template <class T = int>
3653 but, in a partial specialization, they're not allowed even
3654 there, as we have in [temp.class.spec]:
3656 The template parameter list of a specialization shall not
3657 contain default template argument values.
3659 So, for a partial specialization, or for a function template
3660 (in C++98/C++03), we look at all of them. */
3663 /* But, for a primary class template that is not a partial
3664 specialization we look at all template parameters except the
3666 parms = TREE_CHAIN (parms);
3668 /* Figure out what error message to issue. */
3669 if (is_friend_decl == 2)
3670 msg = "default template arguments may not be used in function template friend re-declaration";
3671 else if (is_friend_decl)
3672 msg = "default template arguments may not be used in function template friend declarations";
3673 else if (TREE_CODE (decl) == FUNCTION_DECL && (cxx_dialect == cxx98))
3674 msg = "default template arguments may not be used in function templates";
3675 else if (is_partial)
3676 msg = "default template arguments may not be used in partial specializations";
3678 msg = "default argument for template parameter for class enclosing %qD";
3680 if (current_class_type && TYPE_BEING_DEFINED (current_class_type))
3681 /* If we're inside a class definition, there's no need to
3682 examine the parameters to the class itself. On the one
3683 hand, they will be checked when the class is defined, and,
3684 on the other, default arguments are valid in things like:
3685 template <class T = double>
3686 struct S { template <class U> void f(U); };
3687 Here the default argument for `S' has no bearing on the
3688 declaration of `f'. */
3689 last_level_to_check = template_class_depth (current_class_type) + 1;
3691 /* Check everything. */
3692 last_level_to_check = 0;
3694 for (parm_level = parms;
3695 parm_level && TMPL_PARMS_DEPTH (parm_level) >= last_level_to_check;
3696 parm_level = TREE_CHAIN (parm_level))
3698 tree inner_parms = TREE_VALUE (parm_level);
3702 ntparms = TREE_VEC_LENGTH (inner_parms);
3703 for (i = 0; i < ntparms; ++i)
3705 if (TREE_VEC_ELT (inner_parms, i) == error_mark_node)
3708 if (TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)))
3713 if (is_friend_decl == 2)
3720 /* Clear out the default argument so that we are not
3722 TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)) = NULL_TREE;
3726 /* At this point, if we're still interested in issuing messages,
3727 they must apply to classes surrounding the object declared. */
3729 msg = "default argument for template parameter for class enclosing %qD";
3735 /* Worker for push_template_decl_real, called via
3736 for_each_template_parm. DATA is really an int, indicating the
3737 level of the parameters we are interested in. If T is a template
3738 parameter of that level, return nonzero. */
3741 template_parm_this_level_p (tree t, void* data)
3743 int this_level = *(int *)data;
3746 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
3747 level = TEMPLATE_PARM_LEVEL (t);
3749 level = TEMPLATE_TYPE_LEVEL (t);
3750 return level == this_level;
3753 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
3754 parameters given by current_template_args, or reuses a
3755 previously existing one, if appropriate. Returns the DECL, or an
3756 equivalent one, if it is replaced via a call to duplicate_decls.
3758 If IS_FRIEND is true, DECL is a friend declaration. */
3761 push_template_decl_real (tree decl, bool is_friend)
3769 int new_template_p = 0;
3770 /* True if the template is a member template, in the sense of
3772 bool member_template_p = false;
3774 if (decl == error_mark_node || !current_template_parms)
3775 return error_mark_node;
3777 /* See if this is a partial specialization. */
3778 is_partial = (DECL_IMPLICIT_TYPEDEF_P (decl)
3779 && TREE_CODE (TREE_TYPE (decl)) != ENUMERAL_TYPE
3780 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)));
3782 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_FRIEND_P (decl))
3786 /* For a friend, we want the context of the friend function, not
3787 the type of which it is a friend. */
3788 ctx = DECL_CONTEXT (decl);
3789 else if (CP_DECL_CONTEXT (decl)
3790 && TREE_CODE (CP_DECL_CONTEXT (decl)) != NAMESPACE_DECL)
3791 /* In the case of a virtual function, we want the class in which
3793 ctx = CP_DECL_CONTEXT (decl);
3795 /* Otherwise, if we're currently defining some class, the DECL
3796 is assumed to be a member of the class. */
3797 ctx = current_scope ();
3799 if (ctx && TREE_CODE (ctx) == NAMESPACE_DECL)
3802 if (!DECL_CONTEXT (decl))
3803 DECL_CONTEXT (decl) = FROB_CONTEXT (current_namespace);
3805 /* See if this is a primary template. */
3806 if (is_friend && ctx)
3807 /* A friend template that specifies a class context, i.e.
3808 template <typename T> friend void A<T>::f();
3812 primary = template_parm_scope_p ();
3816 if (DECL_CLASS_SCOPE_P (decl))
3817 member_template_p = true;
3818 if (TREE_CODE (decl) == TYPE_DECL
3819 && ANON_AGGRNAME_P (DECL_NAME (decl)))
3821 error ("template class without a name");
3822 return error_mark_node;
3824 else if (TREE_CODE (decl) == FUNCTION_DECL)
3826 if (DECL_DESTRUCTOR_P (decl))
3830 A destructor shall not be a member template. */
3831 error ("destructor %qD declared as member template", decl);
3832 return error_mark_node;
3834 if (NEW_DELETE_OPNAME_P (DECL_NAME (decl))
3835 && (!TYPE_ARG_TYPES (TREE_TYPE (decl))
3836 || TYPE_ARG_TYPES (TREE_TYPE (decl)) == void_list_node
3837 || !TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (decl)))
3838 || (TREE_CHAIN (TYPE_ARG_TYPES ((TREE_TYPE (decl))))
3839 == void_list_node)))
3841 /* [basic.stc.dynamic.allocation]
3843 An allocation function can be a function
3844 template. ... Template allocation functions shall
3845 have two or more parameters. */
3846 error ("invalid template declaration of %qD", decl);
3847 return error_mark_node;
3850 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
3851 && CLASS_TYPE_P (TREE_TYPE (decl)))
3855 error ("template declaration of %q#D", decl);
3856 return error_mark_node;
3860 /* Check to see that the rules regarding the use of default
3861 arguments are not being violated. */
3862 check_default_tmpl_args (decl, current_template_parms,
3863 primary, is_partial, /*is_friend_decl=*/0);
3865 /* Ensure that there are no parameter packs in the type of this
3866 declaration that have not been expanded. */
3867 if (TREE_CODE (decl) == FUNCTION_DECL)
3869 /* Check each of the arguments individually to see if there are
3870 any bare parameter packs. */
3871 tree type = TREE_TYPE (decl);
3872 tree arg = DECL_ARGUMENTS (decl);
3873 tree argtype = TYPE_ARG_TYPES (type);
3875 while (arg && argtype)
3877 if (!FUNCTION_PARAMETER_PACK_P (arg)
3878 && check_for_bare_parameter_packs (TREE_TYPE (arg)))
3880 /* This is a PARM_DECL that contains unexpanded parameter
3881 packs. We have already complained about this in the
3882 check_for_bare_parameter_packs call, so just replace
3883 these types with ERROR_MARK_NODE. */
3884 TREE_TYPE (arg) = error_mark_node;
3885 TREE_VALUE (argtype) = error_mark_node;
3888 arg = TREE_CHAIN (arg);
3889 argtype = TREE_CHAIN (argtype);
3892 /* Check for bare parameter packs in the return type and the
3893 exception specifiers. */
3894 if (check_for_bare_parameter_packs (TREE_TYPE (type)))
3895 /* Errors were already issued, set return type to int
3896 as the frontend doesn't expect error_mark_node as
3898 TREE_TYPE (type) = integer_type_node;
3899 if (check_for_bare_parameter_packs (TYPE_RAISES_EXCEPTIONS (type)))
3900 TYPE_RAISES_EXCEPTIONS (type) = NULL_TREE;
3902 else if (check_for_bare_parameter_packs (TREE_TYPE (decl)))
3904 TREE_TYPE (decl) = error_mark_node;
3905 return error_mark_node;
3909 return process_partial_specialization (decl);
3911 args = current_template_args ();
3914 || TREE_CODE (ctx) == FUNCTION_DECL
3915 || (CLASS_TYPE_P (ctx) && TYPE_BEING_DEFINED (ctx))
3916 || (is_friend && !DECL_TEMPLATE_INFO (decl)))
3918 if (DECL_LANG_SPECIFIC (decl)
3919 && DECL_TEMPLATE_INFO (decl)
3920 && DECL_TI_TEMPLATE (decl))
3921 tmpl = DECL_TI_TEMPLATE (decl);
3922 /* If DECL is a TYPE_DECL for a class-template, then there won't
3923 be DECL_LANG_SPECIFIC. The information equivalent to
3924 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
3925 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
3926 && TYPE_TEMPLATE_INFO (TREE_TYPE (decl))
3927 && TYPE_TI_TEMPLATE (TREE_TYPE (decl)))
3929 /* Since a template declaration already existed for this
3930 class-type, we must be redeclaring it here. Make sure
3931 that the redeclaration is valid. */
3932 redeclare_class_template (TREE_TYPE (decl),
3933 current_template_parms);
3934 /* We don't need to create a new TEMPLATE_DECL; just use the
3935 one we already had. */
3936 tmpl = TYPE_TI_TEMPLATE (TREE_TYPE (decl));
3940 tmpl = build_template_decl (decl, current_template_parms,
3944 if (DECL_LANG_SPECIFIC (decl)
3945 && DECL_TEMPLATE_SPECIALIZATION (decl))
3947 /* A specialization of a member template of a template
3949 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
3950 DECL_TEMPLATE_INFO (tmpl) = DECL_TEMPLATE_INFO (decl);
3951 DECL_TEMPLATE_INFO (decl) = NULL_TREE;
3957 tree a, t, current, parms;
3959 tree tinfo = get_template_info (decl);
3963 error ("template definition of non-template %q#D", decl);
3964 return error_mark_node;
3967 tmpl = TI_TEMPLATE (tinfo);
3969 if (DECL_FUNCTION_TEMPLATE_P (tmpl)
3970 && DECL_TEMPLATE_INFO (decl) && DECL_TI_ARGS (decl)
3971 && DECL_TEMPLATE_SPECIALIZATION (decl)
3972 && DECL_MEMBER_TEMPLATE_P (tmpl))
3976 /* The declaration is a specialization of a member
3977 template, declared outside the class. Therefore, the
3978 innermost template arguments will be NULL, so we
3979 replace them with the arguments determined by the
3980 earlier call to check_explicit_specialization. */
3981 args = DECL_TI_ARGS (decl);
3984 = build_template_decl (decl, current_template_parms,
3986 DECL_TEMPLATE_RESULT (new_tmpl) = decl;
3987 TREE_TYPE (new_tmpl) = TREE_TYPE (decl);
3988 DECL_TI_TEMPLATE (decl) = new_tmpl;
3989 SET_DECL_TEMPLATE_SPECIALIZATION (new_tmpl);
3990 DECL_TEMPLATE_INFO (new_tmpl)
3991 = tree_cons (tmpl, args, NULL_TREE);
3993 register_specialization (new_tmpl,
3994 most_general_template (tmpl),
4000 /* Make sure the template headers we got make sense. */
4002 parms = DECL_TEMPLATE_PARMS (tmpl);
4003 i = TMPL_PARMS_DEPTH (parms);
4004 if (TMPL_ARGS_DEPTH (args) != i)
4006 error ("expected %d levels of template parms for %q#D, got %d",
4007 i, decl, TMPL_ARGS_DEPTH (args));
4010 for (current = decl; i > 0; --i, parms = TREE_CHAIN (parms))
4012 a = TMPL_ARGS_LEVEL (args, i);
4013 t = INNERMOST_TEMPLATE_PARMS (parms);
4015 if (TREE_VEC_LENGTH (t) != TREE_VEC_LENGTH (a))
4017 if (current == decl)
4018 error ("got %d template parameters for %q#D",
4019 TREE_VEC_LENGTH (a), decl);
4021 error ("got %d template parameters for %q#T",
4022 TREE_VEC_LENGTH (a), current);
4023 error (" but %d required", TREE_VEC_LENGTH (t));
4024 return error_mark_node;
4027 if (current == decl)
4030 current = (TYPE_P (current)
4031 ? TYPE_CONTEXT (current)
4032 : DECL_CONTEXT (current));
4035 /* Check that the parms are used in the appropriate qualifying scopes
4036 in the declarator. */
4037 if (!comp_template_args
4039 TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (tmpl)))))
4042 template arguments to %qD do not match original template %qD",
4043 decl, DECL_TEMPLATE_RESULT (tmpl));
4044 if (!uses_template_parms (TI_ARGS (tinfo)))
4045 inform (input_location, "use template<> for an explicit specialization");
4046 /* Avoid crash in import_export_decl. */
4047 DECL_INTERFACE_KNOWN (decl) = 1;
4048 return error_mark_node;
4052 DECL_TEMPLATE_RESULT (tmpl) = decl;
4053 TREE_TYPE (tmpl) = TREE_TYPE (decl);
4055 /* Push template declarations for global functions and types. Note
4056 that we do not try to push a global template friend declared in a
4057 template class; such a thing may well depend on the template
4058 parameters of the class. */
4059 if (new_template_p && !ctx
4060 && !(is_friend && template_class_depth (current_class_type) > 0))
4062 tmpl = pushdecl_namespace_level (tmpl, is_friend);
4063 if (tmpl == error_mark_node)
4064 return error_mark_node;
4066 /* Hide template friend classes that haven't been declared yet. */
4067 if (is_friend && TREE_CODE (decl) == TYPE_DECL)
4069 DECL_ANTICIPATED (tmpl) = 1;
4070 DECL_FRIEND_P (tmpl) = 1;
4076 tree parms = DECL_TEMPLATE_PARMS (tmpl);
4079 DECL_PRIMARY_TEMPLATE (tmpl) = tmpl;
4080 if (DECL_CONV_FN_P (tmpl))
4082 int depth = TMPL_PARMS_DEPTH (parms);
4084 /* It is a conversion operator. See if the type converted to
4085 depends on innermost template operands. */
4087 if (uses_template_parms_level (TREE_TYPE (TREE_TYPE (tmpl)),
4089 DECL_TEMPLATE_CONV_FN_P (tmpl) = 1;
4092 /* Give template template parms a DECL_CONTEXT of the template
4093 for which they are a parameter. */
4094 parms = INNERMOST_TEMPLATE_PARMS (parms);
4095 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
4097 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
4098 if (TREE_CODE (parm) == TEMPLATE_DECL)
4099 DECL_CONTEXT (parm) = tmpl;
4103 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
4104 back to its most general template. If TMPL is a specialization,
4105 ARGS may only have the innermost set of arguments. Add the missing
4106 argument levels if necessary. */
4107 if (DECL_TEMPLATE_INFO (tmpl))
4108 args = add_outermost_template_args (DECL_TI_ARGS (tmpl), args);
4110 info = tree_cons (tmpl, args, NULL_TREE);
4112 if (DECL_IMPLICIT_TYPEDEF_P (decl))
4113 SET_TYPE_TEMPLATE_INFO (TREE_TYPE (tmpl), info);
4114 else if (DECL_LANG_SPECIFIC (decl))
4115 DECL_TEMPLATE_INFO (decl) = info;
4117 return DECL_TEMPLATE_RESULT (tmpl);
4121 push_template_decl (tree decl)
4123 return push_template_decl_real (decl, false);
4126 /* Called when a class template TYPE is redeclared with the indicated
4127 template PARMS, e.g.:
4129 template <class T> struct S;
4130 template <class T> struct S {}; */
4133 redeclare_class_template (tree type, tree parms)
4139 if (!TYPE_TEMPLATE_INFO (type))
4141 error ("%qT is not a template type", type);
4145 tmpl = TYPE_TI_TEMPLATE (type);
4146 if (!PRIMARY_TEMPLATE_P (tmpl))
4147 /* The type is nested in some template class. Nothing to worry
4148 about here; there are no new template parameters for the nested
4154 error ("template specifiers not specified in declaration of %qD",
4159 parms = INNERMOST_TEMPLATE_PARMS (parms);
4160 tmpl_parms = DECL_INNERMOST_TEMPLATE_PARMS (tmpl);
4162 if (TREE_VEC_LENGTH (parms) != TREE_VEC_LENGTH (tmpl_parms))
4164 error ("redeclared with %d template parameter(s)",
4165 TREE_VEC_LENGTH (parms));
4166 inform (input_location, "previous declaration %q+D used %d template parameter(s)",
4167 tmpl, TREE_VEC_LENGTH (tmpl_parms));
4171 for (i = 0; i < TREE_VEC_LENGTH (tmpl_parms); ++i)
4178 if (TREE_VEC_ELT (tmpl_parms, i) == error_mark_node
4179 || TREE_VEC_ELT (parms, i) == error_mark_node)
4182 tmpl_parm = TREE_VALUE (TREE_VEC_ELT (tmpl_parms, i));
4183 parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
4184 tmpl_default = TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i));
4185 parm_default = TREE_PURPOSE (TREE_VEC_ELT (parms, i));
4187 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
4189 if (tmpl_parm != error_mark_node
4190 && (TREE_CODE (tmpl_parm) != TREE_CODE (parm)
4191 || (TREE_CODE (tmpl_parm) != TYPE_DECL
4192 && !same_type_p (TREE_TYPE (tmpl_parm), TREE_TYPE (parm)))
4193 || (TREE_CODE (tmpl_parm) != PARM_DECL
4194 && (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (tmpl_parm))
4195 != TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm))))
4196 || (TREE_CODE (tmpl_parm) == PARM_DECL
4197 && (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (tmpl_parm))
4198 != TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))))))
4200 error ("template parameter %q+#D", tmpl_parm);
4201 error ("redeclared here as %q#D", parm);
4205 if (tmpl_default != NULL_TREE && parm_default != NULL_TREE)
4207 /* We have in [temp.param]:
4209 A template-parameter may not be given default arguments
4210 by two different declarations in the same scope. */
4211 error ("redefinition of default argument for %q#D", parm);
4212 inform (input_location, "%Joriginal definition appeared here", tmpl_parm);
4216 if (parm_default != NULL_TREE)
4217 /* Update the previous template parameters (which are the ones
4218 that will really count) with the new default value. */
4219 TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i)) = parm_default;
4220 else if (tmpl_default != NULL_TREE)
4221 /* Update the new parameters, too; they'll be used as the
4222 parameters for any members. */
4223 TREE_PURPOSE (TREE_VEC_ELT (parms, i)) = tmpl_default;
4229 /* Simplify EXPR if it is a non-dependent expression. Returns the
4230 (possibly simplified) expression. */
4233 fold_non_dependent_expr (tree expr)
4235 if (expr == NULL_TREE)
4238 /* If we're in a template, but EXPR isn't value dependent, simplify
4239 it. We're supposed to treat:
4241 template <typename T> void f(T[1 + 1]);
4242 template <typename T> void f(T[2]);
4244 as two declarations of the same function, for example. */
4245 if (processing_template_decl
4246 && !type_dependent_expression_p (expr)
4247 && !value_dependent_expression_p (expr))
4249 HOST_WIDE_INT saved_processing_template_decl;
4251 saved_processing_template_decl = processing_template_decl;
4252 processing_template_decl = 0;
4253 expr = tsubst_copy_and_build (expr,
4256 /*in_decl=*/NULL_TREE,
4257 /*function_p=*/false,
4258 /*integral_constant_expression_p=*/true);
4259 processing_template_decl = saved_processing_template_decl;
4264 /* EXPR is an expression which is used in a constant-expression context.
4265 For instance, it could be a VAR_DECL with a constant initializer.
4266 Extract the innermost constant expression.
4268 This is basically a more powerful version of
4269 integral_constant_value, which can be used also in templates where
4270 initializers can maintain a syntactic rather than semantic form
4271 (even if they are non-dependent, for access-checking purposes). */
4274 fold_decl_constant_value (tree expr)
4276 tree const_expr = expr;
4279 expr = fold_non_dependent_expr (const_expr);
4280 const_expr = integral_constant_value (expr);
4282 while (expr != const_expr);
4287 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
4288 must be a function or a pointer-to-function type, as specified
4289 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
4290 and check that the resulting function has external linkage. */
4293 convert_nontype_argument_function (tree type, tree expr)
4298 fn = instantiate_type (type, fns, tf_none);
4299 if (fn == error_mark_node)
4300 return error_mark_node;
4303 if (TREE_CODE (fn_no_ptr) == ADDR_EXPR)
4304 fn_no_ptr = TREE_OPERAND (fn_no_ptr, 0);
4305 if (TREE_CODE (fn_no_ptr) == BASELINK)
4306 fn_no_ptr = BASELINK_FUNCTIONS (fn_no_ptr);
4308 /* [temp.arg.nontype]/1
4310 A template-argument for a non-type, non-template template-parameter
4313 -- the address of an object or function with external linkage. */
4314 if (!DECL_EXTERNAL_LINKAGE_P (fn_no_ptr))
4316 error ("%qE is not a valid template argument for type %qT "
4317 "because function %qD has not external linkage",
4318 expr, type, fn_no_ptr);
4325 /* Attempt to convert the non-type template parameter EXPR to the
4326 indicated TYPE. If the conversion is successful, return the
4327 converted value. If the conversion is unsuccessful, return
4328 NULL_TREE if we issued an error message, or error_mark_node if we
4329 did not. We issue error messages for out-and-out bad template
4330 parameters, but not simply because the conversion failed, since we
4331 might be just trying to do argument deduction. Both TYPE and EXPR
4332 must be non-dependent.
4334 The conversion follows the special rules described in
4335 [temp.arg.nontype], and it is much more strict than an implicit
4338 This function is called twice for each template argument (see
4339 lookup_template_class for a more accurate description of this
4340 problem). This means that we need to handle expressions which
4341 are not valid in a C++ source, but can be created from the
4342 first call (for instance, casts to perform conversions). These
4343 hacks can go away after we fix the double coercion problem. */
4346 convert_nontype_argument (tree type, tree expr)
4350 /* Detect immediately string literals as invalid non-type argument.
4351 This special-case is not needed for correctness (we would easily
4352 catch this later), but only to provide better diagnostic for this
4353 common user mistake. As suggested by DR 100, we do not mention
4354 linkage issues in the diagnostic as this is not the point. */
4355 if (TREE_CODE (expr) == STRING_CST)
4357 error ("%qE is not a valid template argument for type %qT "
4358 "because string literals can never be used in this context",
4363 /* If we are in a template, EXPR may be non-dependent, but still
4364 have a syntactic, rather than semantic, form. For example, EXPR
4365 might be a SCOPE_REF, rather than the VAR_DECL to which the
4366 SCOPE_REF refers. Preserving the qualifying scope is necessary
4367 so that access checking can be performed when the template is
4368 instantiated -- but here we need the resolved form so that we can
4369 convert the argument. */
4370 expr = fold_non_dependent_expr (expr);
4371 if (error_operand_p (expr))
4372 return error_mark_node;
4373 expr_type = TREE_TYPE (expr);
4375 /* HACK: Due to double coercion, we can get a
4376 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
4377 which is the tree that we built on the first call (see
4378 below when coercing to reference to object or to reference to
4379 function). We just strip everything and get to the arg.
4380 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
4382 if (TREE_CODE (expr) == NOP_EXPR)
4384 if (TYPE_REF_OBJ_P (type) || TYPE_REFFN_P (type))
4386 /* ??? Maybe we could use convert_from_reference here, but we
4387 would need to relax its constraints because the NOP_EXPR
4388 could actually change the type to something more cv-qualified,
4389 and this is not folded by convert_from_reference. */
4390 tree addr = TREE_OPERAND (expr, 0);
4391 gcc_assert (TREE_CODE (expr_type) == REFERENCE_TYPE);
4392 gcc_assert (TREE_CODE (addr) == ADDR_EXPR);
4393 gcc_assert (TREE_CODE (TREE_TYPE (addr)) == POINTER_TYPE);
4394 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4395 (TREE_TYPE (expr_type),
4396 TREE_TYPE (TREE_TYPE (addr))));
4398 expr = TREE_OPERAND (addr, 0);
4399 expr_type = TREE_TYPE (expr);
4402 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
4403 parameter is a pointer to object, through decay and
4404 qualification conversion. Let's strip everything. */
4405 else if (TYPE_PTROBV_P (type))
4408 gcc_assert (TREE_CODE (expr) == ADDR_EXPR);
4409 gcc_assert (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE);
4410 /* Skip the ADDR_EXPR only if it is part of the decay for
4411 an array. Otherwise, it is part of the original argument
4412 in the source code. */
4413 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == ARRAY_TYPE)
4414 expr = TREE_OPERAND (expr, 0);
4415 expr_type = TREE_TYPE (expr);
4419 /* [temp.arg.nontype]/5, bullet 1
4421 For a non-type template-parameter of integral or enumeration type,
4422 integral promotions (_conv.prom_) and integral conversions
4423 (_conv.integral_) are applied. */
4424 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
4426 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (expr_type))
4427 return error_mark_node;
4429 expr = fold_decl_constant_value (expr);
4430 /* Notice that there are constant expressions like '4 % 0' which
4431 do not fold into integer constants. */
4432 if (TREE_CODE (expr) != INTEGER_CST)
4434 error ("%qE is not a valid template argument for type %qT "
4435 "because it is a non-constant expression", expr, type);
4439 /* At this point, an implicit conversion does what we want,
4440 because we already know that the expression is of integral
4442 expr = ocp_convert (type, expr, CONV_IMPLICIT, LOOKUP_PROTECT);
4443 if (expr == error_mark_node)
4444 return error_mark_node;
4446 /* Conversion was allowed: fold it to a bare integer constant. */
4449 /* [temp.arg.nontype]/5, bullet 2
4451 For a non-type template-parameter of type pointer to object,
4452 qualification conversions (_conv.qual_) and the array-to-pointer
4453 conversion (_conv.array_) are applied. */
4454 else if (TYPE_PTROBV_P (type))
4456 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
4458 A template-argument for a non-type, non-template template-parameter
4459 shall be one of: [...]
4461 -- the name of a non-type template-parameter;
4462 -- the address of an object or function with external linkage, [...]
4463 expressed as "& id-expression" where the & is optional if the name
4464 refers to a function or array, or if the corresponding
4465 template-parameter is a reference.
4467 Here, we do not care about functions, as they are invalid anyway
4468 for a parameter of type pointer-to-object. */
4470 if (DECL_P (expr) && DECL_TEMPLATE_PARM_P (expr))
4471 /* Non-type template parameters are OK. */
4473 else if (TREE_CODE (expr) != ADDR_EXPR
4474 && TREE_CODE (expr_type) != ARRAY_TYPE)
4476 if (TREE_CODE (expr) == VAR_DECL)
4478 error ("%qD is not a valid template argument "
4479 "because %qD is a variable, not the address of "
4484 /* Other values, like integer constants, might be valid
4485 non-type arguments of some other type. */
4486 return error_mark_node;
4492 decl = ((TREE_CODE (expr) == ADDR_EXPR)
4493 ? TREE_OPERAND (expr, 0) : expr);
4494 if (TREE_CODE (decl) != VAR_DECL)
4496 error ("%qE is not a valid template argument of type %qT "
4497 "because %qE is not a variable",
4501 else if (!DECL_EXTERNAL_LINKAGE_P (decl))
4503 error ("%qE is not a valid template argument of type %qT "
4504 "because %qD does not have external linkage",
4510 expr = decay_conversion (expr);
4511 if (expr == error_mark_node)
4512 return error_mark_node;
4514 expr = perform_qualification_conversions (type, expr);
4515 if (expr == error_mark_node)
4516 return error_mark_node;
4518 /* [temp.arg.nontype]/5, bullet 3
4520 For a non-type template-parameter of type reference to object, no
4521 conversions apply. The type referred to by the reference may be more
4522 cv-qualified than the (otherwise identical) type of the
4523 template-argument. The template-parameter is bound directly to the
4524 template-argument, which must be an lvalue. */
4525 else if (TYPE_REF_OBJ_P (type))
4527 if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type),
4529 return error_mark_node;
4531 if (!at_least_as_qualified_p (TREE_TYPE (type), expr_type))
4533 error ("%qE is not a valid template argument for type %qT "
4534 "because of conflicts in cv-qualification", expr, type);
4538 if (!real_lvalue_p (expr))
4540 error ("%qE is not a valid template argument for type %qT "
4541 "because it is not an lvalue", expr, type);
4545 /* [temp.arg.nontype]/1
4547 A template-argument for a non-type, non-template template-parameter
4548 shall be one of: [...]
4550 -- the address of an object or function with external linkage. */
4551 if (!DECL_EXTERNAL_LINKAGE_P (expr))
4553 error ("%qE is not a valid template argument for type %qT "
4554 "because object %qD has not external linkage",
4559 expr = build_nop (type, build_address (expr));
4561 /* [temp.arg.nontype]/5, bullet 4
4563 For a non-type template-parameter of type pointer to function, only
4564 the function-to-pointer conversion (_conv.func_) is applied. If the
4565 template-argument represents a set of overloaded functions (or a
4566 pointer to such), the matching function is selected from the set
4568 else if (TYPE_PTRFN_P (type))
4570 /* If the argument is a template-id, we might not have enough
4571 context information to decay the pointer. */
4572 if (!type_unknown_p (expr_type))
4574 expr = decay_conversion (expr);
4575 if (expr == error_mark_node)
4576 return error_mark_node;
4579 expr = convert_nontype_argument_function (type, expr);
4580 if (!expr || expr == error_mark_node)
4583 if (TREE_CODE (expr) != ADDR_EXPR)
4585 error ("%qE is not a valid template argument for type %qT", expr, type);
4586 error ("it must be the address of a function with external linkage");
4590 /* [temp.arg.nontype]/5, bullet 5
4592 For a non-type template-parameter of type reference to function, no
4593 conversions apply. If the template-argument represents a set of
4594 overloaded functions, the matching function is selected from the set
4596 else if (TYPE_REFFN_P (type))
4598 if (TREE_CODE (expr) == ADDR_EXPR)
4600 error ("%qE is not a valid template argument for type %qT "
4601 "because it is a pointer", expr, type);
4602 inform (input_location, "try using %qE instead", TREE_OPERAND (expr, 0));
4606 expr = convert_nontype_argument_function (TREE_TYPE (type), expr);
4607 if (!expr || expr == error_mark_node)
4610 expr = build_nop (type, build_address (expr));
4612 /* [temp.arg.nontype]/5, bullet 6
4614 For a non-type template-parameter of type pointer to member function,
4615 no conversions apply. If the template-argument represents a set of
4616 overloaded member functions, the matching member function is selected
4617 from the set (_over.over_). */
4618 else if (TYPE_PTRMEMFUNC_P (type))
4620 expr = instantiate_type (type, expr, tf_none);
4621 if (expr == error_mark_node)
4622 return error_mark_node;
4624 /* There is no way to disable standard conversions in
4625 resolve_address_of_overloaded_function (called by
4626 instantiate_type). It is possible that the call succeeded by
4627 converting &B::I to &D::I (where B is a base of D), so we need
4628 to reject this conversion here.
4630 Actually, even if there was a way to disable standard conversions,
4631 it would still be better to reject them here so that we can
4632 provide a superior diagnostic. */
4633 if (!same_type_p (TREE_TYPE (expr), type))
4635 /* Make sure we are just one standard conversion off. */
4636 gcc_assert (can_convert (type, TREE_TYPE (expr)));
4637 error ("%qE is not a valid template argument for type %qT "
4638 "because it is of type %qT", expr, type,
4640 inform (input_location, "standard conversions are not allowed in this context");
4644 /* [temp.arg.nontype]/5, bullet 7
4646 For a non-type template-parameter of type pointer to data member,
4647 qualification conversions (_conv.qual_) are applied. */
4648 else if (TYPE_PTRMEM_P (type))
4650 expr = perform_qualification_conversions (type, expr);
4651 if (expr == error_mark_node)
4654 /* A template non-type parameter must be one of the above. */
4658 /* Sanity check: did we actually convert the argument to the
4660 gcc_assert (same_type_p (type, TREE_TYPE (expr)));
4664 /* Subroutine of coerce_template_template_parms, which returns 1 if
4665 PARM_PARM and ARG_PARM match using the rule for the template
4666 parameters of template template parameters. Both PARM and ARG are
4667 template parameters; the rest of the arguments are the same as for
4668 coerce_template_template_parms.
4671 coerce_template_template_parm (tree parm,
4673 tsubst_flags_t complain,
4677 if (arg == NULL_TREE || arg == error_mark_node
4678 || parm == NULL_TREE || parm == error_mark_node)
4681 if (TREE_CODE (arg) != TREE_CODE (parm))
4684 switch (TREE_CODE (parm))
4687 /* We encounter instantiations of templates like
4688 template <template <template <class> class> class TT>
4691 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
4692 tree argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
4694 if (!coerce_template_template_parms
4695 (parmparm, argparm, complain, in_decl, outer_args))
4701 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (arg))
4702 && !TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
4703 /* Argument is a parameter pack but parameter is not. */
4708 /* The tsubst call is used to handle cases such as
4710 template <int> class C {};
4711 template <class T, template <T> class TT> class D {};
4714 i.e. the parameter list of TT depends on earlier parameters. */
4715 if (!uses_template_parms (TREE_TYPE (arg))
4717 (tsubst (TREE_TYPE (parm), outer_args, complain, in_decl),
4721 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (arg))
4722 && !TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
4723 /* Argument is a parameter pack but parameter is not. */
4736 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
4737 template template parameters. Both PARM_PARMS and ARG_PARMS are
4738 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
4741 Consider the example:
4742 template <class T> class A;
4743 template<template <class U> class TT> class B;
4745 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
4746 the parameters to A, and OUTER_ARGS contains A. */
4749 coerce_template_template_parms (tree parm_parms,
4751 tsubst_flags_t complain,
4755 int nparms, nargs, i;
4759 gcc_assert (TREE_CODE (parm_parms) == TREE_VEC);
4760 gcc_assert (TREE_CODE (arg_parms) == TREE_VEC);
4762 nparms = TREE_VEC_LENGTH (parm_parms);
4763 nargs = TREE_VEC_LENGTH (arg_parms);
4765 /* Determine whether we have a parameter pack at the end of the
4766 template template parameter's template parameter list. */
4767 if (TREE_VEC_ELT (parm_parms, nparms - 1) != error_mark_node)
4769 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, nparms - 1));
4771 if (parm == error_mark_node)
4774 switch (TREE_CODE (parm))
4778 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
4783 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
4793 && !(variadic_p && nargs >= nparms - 1))
4796 /* Check all of the template parameters except the parameter pack at
4797 the end (if any). */
4798 for (i = 0; i < nparms - variadic_p; ++i)
4800 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node
4801 || TREE_VEC_ELT (arg_parms, i) == error_mark_node)
4804 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
4805 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
4807 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
4815 /* Check each of the template parameters in the template
4816 argument against the template parameter pack at the end of
4817 the template template parameter. */
4818 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node)
4821 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
4823 for (; i < nargs; ++i)
4825 if (TREE_VEC_ELT (arg_parms, i) == error_mark_node)
4828 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
4830 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
4839 /* Verifies that the deduced template arguments (in TARGS) for the
4840 template template parameters (in TPARMS) represent valid bindings,
4841 by comparing the template parameter list of each template argument
4842 to the template parameter list of its corresponding template
4843 template parameter, in accordance with DR150. This
4844 routine can only be called after all template arguments have been
4845 deduced. It will return TRUE if all of the template template
4846 parameter bindings are okay, FALSE otherwise. */
4848 template_template_parm_bindings_ok_p (tree tparms, tree targs)
4850 int i, ntparms = TREE_VEC_LENGTH (tparms);
4853 /* We're dealing with template parms in this process. */
4854 ++processing_template_decl;
4856 targs = INNERMOST_TEMPLATE_ARGS (targs);
4858 for (i = 0; i < ntparms; ++i)
4860 tree tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
4861 tree targ = TREE_VEC_ELT (targs, i);
4863 if (TREE_CODE (tparm) == TEMPLATE_DECL && targ)
4865 tree packed_args = NULL_TREE;
4868 if (ARGUMENT_PACK_P (targ))
4870 /* Look inside the argument pack. */
4871 packed_args = ARGUMENT_PACK_ARGS (targ);
4872 len = TREE_VEC_LENGTH (packed_args);
4875 for (idx = 0; idx < len; ++idx)
4877 tree targ_parms = NULL_TREE;
4880 /* Extract the next argument from the argument
4882 targ = TREE_VEC_ELT (packed_args, idx);
4884 if (PACK_EXPANSION_P (targ))
4885 /* Look at the pattern of the pack expansion. */
4886 targ = PACK_EXPANSION_PATTERN (targ);
4888 /* Extract the template parameters from the template
4890 if (TREE_CODE (targ) == TEMPLATE_DECL)
4891 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (targ);
4892 else if (TREE_CODE (targ) == TEMPLATE_TEMPLATE_PARM)
4893 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (TYPE_NAME (targ));
4895 /* Verify that we can coerce the template template
4896 parameters from the template argument to the template
4897 parameter. This requires an exact match. */
4899 && !coerce_template_template_parms
4900 (DECL_INNERMOST_TEMPLATE_PARMS (tparm),
4915 --processing_template_decl;
4919 /* Convert the indicated template ARG as necessary to match the
4920 indicated template PARM. Returns the converted ARG, or
4921 error_mark_node if the conversion was unsuccessful. Error and
4922 warning messages are issued under control of COMPLAIN. This
4923 conversion is for the Ith parameter in the parameter list. ARGS is
4924 the full set of template arguments deduced so far. */
4927 convert_template_argument (tree parm,
4930 tsubst_flags_t complain,
4936 int is_type, requires_type, is_tmpl_type, requires_tmpl_type;
4938 if (TREE_CODE (arg) == TREE_LIST
4939 && TREE_CODE (TREE_VALUE (arg)) == OFFSET_REF)
4941 /* The template argument was the name of some
4942 member function. That's usually
4943 invalid, but static members are OK. In any
4944 case, grab the underlying fields/functions
4945 and issue an error later if required. */
4946 orig_arg = TREE_VALUE (arg);
4947 TREE_TYPE (arg) = unknown_type_node;
4952 requires_tmpl_type = TREE_CODE (parm) == TEMPLATE_DECL;
4953 requires_type = (TREE_CODE (parm) == TYPE_DECL
4954 || requires_tmpl_type);
4956 /* When determining whether an argument pack expansion is a template,
4957 look at the pattern. */
4958 if (TREE_CODE (arg) == TYPE_PACK_EXPANSION)
4959 arg = PACK_EXPANSION_PATTERN (arg);
4962 ((TREE_CODE (arg) == TEMPLATE_DECL
4963 && TREE_CODE (DECL_TEMPLATE_RESULT (arg)) == TYPE_DECL)
4964 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
4965 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE);
4968 && (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
4969 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE))
4970 arg = TYPE_STUB_DECL (arg);
4972 is_type = TYPE_P (arg) || is_tmpl_type;
4974 if (requires_type && ! is_type && TREE_CODE (arg) == SCOPE_REF
4975 && TREE_CODE (TREE_OPERAND (arg, 0)) == TEMPLATE_TYPE_PARM)
4977 permerror (input_location, "to refer to a type member of a template parameter, "
4978 "use %<typename %E%>", orig_arg);
4980 orig_arg = make_typename_type (TREE_OPERAND (arg, 0),
4981 TREE_OPERAND (arg, 1),
4983 complain & tf_error);
4987 if (is_type != requires_type)
4991 if (complain & tf_error)
4993 error ("type/value mismatch at argument %d in template "
4994 "parameter list for %qD",
4997 error (" expected a constant of type %qT, got %qT",
4999 (DECL_P (arg) ? DECL_NAME (arg) : orig_arg));
5000 else if (requires_tmpl_type)
5001 error (" expected a class template, got %qE", orig_arg);
5003 error (" expected a type, got %qE", orig_arg);
5006 return error_mark_node;
5008 if (is_tmpl_type ^ requires_tmpl_type)
5010 if (in_decl && (complain & tf_error))
5012 error ("type/value mismatch at argument %d in template "
5013 "parameter list for %qD",
5016 error (" expected a type, got %qT", DECL_NAME (arg));
5018 error (" expected a class template, got %qT", orig_arg);
5020 return error_mark_node;
5025 if (requires_tmpl_type)
5027 if (TREE_CODE (TREE_TYPE (arg)) == UNBOUND_CLASS_TEMPLATE)
5028 /* The number of argument required is not known yet.
5029 Just accept it for now. */
5030 val = TREE_TYPE (arg);
5033 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
5036 argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
5038 if (coerce_template_template_parms (parmparm, argparm,
5044 /* TEMPLATE_TEMPLATE_PARM node is preferred over
5046 if (val != error_mark_node)
5048 if (DECL_TEMPLATE_TEMPLATE_PARM_P (val))
5049 val = TREE_TYPE (val);
5050 else if (TREE_CODE (val) == TYPE_PACK_EXPANSION
5051 && DECL_TEMPLATE_TEMPLATE_PARM_P (arg))
5053 val = TREE_TYPE (arg);
5054 val = make_pack_expansion (val);
5060 if (in_decl && (complain & tf_error))
5062 error ("type/value mismatch at argument %d in "
5063 "template parameter list for %qD",
5065 error (" expected a template of type %qD, got %qD",
5069 val = error_mark_node;
5075 /* We only form one instance of each template specialization.
5076 Therefore, if we use a non-canonical variant (i.e., a
5077 typedef), any future messages referring to the type will use
5078 the typedef, which is confusing if those future uses do not
5079 themselves also use the typedef. */
5081 val = strip_typedefs (val);
5085 tree t = tsubst (TREE_TYPE (parm), args, complain, in_decl);
5087 if (invalid_nontype_parm_type_p (t, complain))
5088 return error_mark_node;
5090 if (template_parameter_pack_p (parm) && ARGUMENT_PACK_P (orig_arg))
5092 if (same_type_p (t, TREE_TYPE (orig_arg)))
5096 /* Not sure if this is reachable, but it doesn't hurt
5098 error ("type mismatch in nontype parameter pack");
5099 val = error_mark_node;
5102 else if (!uses_template_parms (orig_arg) && !uses_template_parms (t))
5103 /* We used to call digest_init here. However, digest_init
5104 will report errors, which we don't want when complain
5105 is zero. More importantly, digest_init will try too
5106 hard to convert things: for example, `0' should not be
5107 converted to pointer type at this point according to
5108 the standard. Accepting this is not merely an
5109 extension, since deciding whether or not these
5110 conversions can occur is part of determining which
5111 function template to call, or whether a given explicit
5112 argument specification is valid. */
5113 val = convert_nontype_argument (t, orig_arg);
5117 if (val == NULL_TREE)
5118 val = error_mark_node;
5119 else if (val == error_mark_node && (complain & tf_error))
5120 error ("could not convert template argument %qE to %qT", orig_arg, t);
5126 /* Coerces the remaining template arguments in INNER_ARGS (from
5127 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
5128 Returns the coerced argument pack. PARM_IDX is the position of this
5129 parameter in the template parameter list. ARGS is the original
5130 template argument list. */
5132 coerce_template_parameter_pack (tree parms,
5140 tsubst_flags_t complain)
5142 tree parm = TREE_VEC_ELT (parms, parm_idx);
5143 int nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
5146 tree packed_types = NULL_TREE;
5148 if (arg_idx > nargs)
5151 packed_args = make_tree_vec (nargs - arg_idx);
5153 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL
5154 && uses_parameter_packs (TREE_TYPE (TREE_VALUE (parm))))
5156 /* When the template parameter is a non-type template
5157 parameter pack whose type uses parameter packs, we need
5158 to look at each of the template arguments
5159 separately. Build a vector of the types for these
5160 non-type template parameters in PACKED_TYPES. */
5162 = make_pack_expansion (TREE_TYPE (TREE_VALUE (parm)));
5163 packed_types = tsubst_pack_expansion (expansion, args,
5166 if (packed_types == error_mark_node)
5167 return error_mark_node;
5169 /* Check that we have the right number of arguments. */
5171 && !PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx))
5172 && nargs - arg_idx != TREE_VEC_LENGTH (packed_types))
5175 = TREE_VEC_LENGTH (parms) - 1 + TREE_VEC_LENGTH (packed_types);
5176 error ("wrong number of template arguments (%d, should be %d)",
5177 nargs, needed_parms);
5178 return error_mark_node;
5181 /* If we aren't able to check the actual arguments now
5182 (because they haven't been expanded yet), we can at least
5183 verify that all of the types used for the non-type
5184 template parameter pack are, in fact, valid for non-type
5185 template parameters. */
5187 && PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx)))
5189 int j, len = TREE_VEC_LENGTH (packed_types);
5190 for (j = 0; j < len; ++j)
5192 tree t = TREE_VEC_ELT (packed_types, j);
5193 if (invalid_nontype_parm_type_p (t, complain))
5194 return error_mark_node;
5199 /* Convert the remaining arguments, which will be a part of the
5200 parameter pack "parm". */
5201 for (; arg_idx < nargs; ++arg_idx)
5203 tree arg = TREE_VEC_ELT (inner_args, arg_idx);
5204 tree actual_parm = TREE_VALUE (parm);
5206 if (packed_types && !PACK_EXPANSION_P (arg))
5208 /* When we have a vector of types (corresponding to the
5209 non-type template parameter pack that uses parameter
5210 packs in its type, as mention above), and the
5211 argument is not an expansion (which expands to a
5212 currently unknown number of arguments), clone the
5213 parm and give it the next type in PACKED_TYPES. */
5214 actual_parm = copy_node (actual_parm);
5215 TREE_TYPE (actual_parm) =
5216 TREE_VEC_ELT (packed_types, arg_idx - parm_idx);
5219 if (arg != error_mark_node)
5220 arg = convert_template_argument (actual_parm,
5221 arg, new_args, complain, parm_idx,
5223 if (arg == error_mark_node)
5225 TREE_VEC_ELT (packed_args, arg_idx - parm_idx) = arg;
5228 if (TREE_CODE (TREE_VALUE (parm)) == TYPE_DECL
5229 || TREE_CODE (TREE_VALUE (parm)) == TEMPLATE_DECL)
5230 argument_pack = make_node (TYPE_ARGUMENT_PACK);
5233 argument_pack = make_node (NONTYPE_ARGUMENT_PACK);
5234 TREE_TYPE (argument_pack)
5235 = tsubst (TREE_TYPE (TREE_VALUE (parm)), new_args, complain, in_decl);
5236 TREE_CONSTANT (argument_pack) = 1;
5239 SET_ARGUMENT_PACK_ARGS (argument_pack, packed_args);
5240 return argument_pack;
5243 /* Convert all template arguments to their appropriate types, and
5244 return a vector containing the innermost resulting template
5245 arguments. If any error occurs, return error_mark_node. Error and
5246 warning messages are issued under control of COMPLAIN.
5248 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
5249 for arguments not specified in ARGS. Otherwise, if
5250 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
5251 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
5252 USE_DEFAULT_ARGS is false, then all arguments must be specified in
5256 coerce_template_parms (tree parms,
5259 tsubst_flags_t complain,
5260 bool require_all_args,
5261 bool use_default_args)
5263 int nparms, nargs, parm_idx, arg_idx, lost = 0;
5266 tree new_inner_args;
5267 int saved_unevaluated_operand;
5268 int saved_inhibit_evaluation_warnings;
5270 /* When used as a boolean value, indicates whether this is a
5271 variadic template parameter list. Since it's an int, we can also
5272 subtract it from nparms to get the number of non-variadic
5276 nparms = TREE_VEC_LENGTH (parms);
5278 /* Determine if there are any parameter packs. */
5279 for (parm_idx = 0; parm_idx < nparms; ++parm_idx)
5281 tree tparm = TREE_VALUE (TREE_VEC_ELT (parms, parm_idx));
5282 if (template_parameter_pack_p (tparm))
5286 inner_args = INNERMOST_TEMPLATE_ARGS (args);
5287 /* If there are 0 or 1 parameter packs, we need to expand any argument
5288 packs so that we can deduce a parameter pack from some non-packed args
5289 followed by an argument pack, as in variadic85.C. If there are more
5290 than that, we need to leave argument packs intact so the arguments are
5291 assigned to the right parameter packs. This should only happen when
5292 dealing with a nested class inside a partial specialization of a class
5293 template, as in variadic92.C. */
5294 if (variadic_p <= 1)
5295 inner_args = expand_template_argument_pack (inner_args);
5297 nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
5298 if ((nargs > nparms && !variadic_p)
5299 || (nargs < nparms - variadic_p
5301 && (!use_default_args
5302 || (TREE_VEC_ELT (parms, nargs) != error_mark_node
5303 && !TREE_PURPOSE (TREE_VEC_ELT (parms, nargs))))))
5305 if (complain & tf_error)
5307 const char *or_more = "";
5310 or_more = " or more";
5314 error ("wrong number of template arguments (%d, should be %d%s)",
5315 nargs, nparms, or_more);
5318 error ("provided for %q+D", in_decl);
5321 return error_mark_node;
5324 /* We need to evaluate the template arguments, even though this
5325 template-id may be nested within a "sizeof". */
5326 saved_unevaluated_operand = cp_unevaluated_operand;
5327 cp_unevaluated_operand = 0;
5328 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
5329 c_inhibit_evaluation_warnings = 0;
5330 new_inner_args = make_tree_vec (nparms);
5331 new_args = add_outermost_template_args (args, new_inner_args);
5332 for (parm_idx = 0, arg_idx = 0; parm_idx < nparms; parm_idx++, arg_idx++)
5337 /* Get the Ith template parameter. */
5338 parm = TREE_VEC_ELT (parms, parm_idx);
5340 if (parm == error_mark_node)
5342 TREE_VEC_ELT (new_inner_args, arg_idx) = error_mark_node;
5346 /* Calculate the next argument. */
5347 if (arg_idx < nargs)
5348 arg = TREE_VEC_ELT (inner_args, arg_idx);
5352 if (template_parameter_pack_p (TREE_VALUE (parm))
5353 && !(arg && ARGUMENT_PACK_P (arg)))
5355 /* All remaining arguments will be placed in the
5356 template parameter pack PARM. */
5357 arg = coerce_template_parameter_pack (parms, parm_idx, args,
5358 inner_args, arg_idx,
5362 /* Store this argument. */
5363 if (arg == error_mark_node)
5365 TREE_VEC_ELT (new_inner_args, parm_idx) = arg;
5367 /* We are done with all of the arguments. */
5374 if (PACK_EXPANSION_P (arg))
5376 if (complain & tf_error)
5378 /* FIXME this restriction was removed by N2555; see
5380 /* If ARG is a pack expansion, but PARM is not a
5381 template parameter pack (if it were, we would have
5382 handled it above), we're trying to expand into a
5383 fixed-length argument list. */
5384 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
5385 sorry ("cannot expand %<%E%> into a fixed-length "
5386 "argument list", arg);
5388 sorry ("cannot expand %<%T%> into a fixed-length "
5389 "argument list", arg);
5391 return error_mark_node;
5394 else if (require_all_args)
5395 /* There must be a default arg in this case. */
5396 arg = tsubst_template_arg (TREE_PURPOSE (parm), new_args,
5401 if (arg == error_mark_node)
5403 if (complain & tf_error)
5404 error ("template argument %d is invalid", arg_idx + 1);
5407 /* This only occurs if there was an error in the template
5408 parameter list itself (which we would already have
5409 reported) that we are trying to recover from, e.g., a class
5410 template with a parameter list such as
5411 template<typename..., typename>. */
5412 return error_mark_node;
5414 arg = convert_template_argument (TREE_VALUE (parm),
5415 arg, new_args, complain,
5418 if (arg == error_mark_node)
5420 TREE_VEC_ELT (new_inner_args, arg_idx) = arg;
5422 cp_unevaluated_operand = saved_unevaluated_operand;
5423 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
5426 return error_mark_node;
5428 return new_inner_args;
5431 /* Returns 1 if template args OT and NT are equivalent. */
5434 template_args_equal (tree ot, tree nt)
5439 if (TREE_CODE (nt) == TREE_VEC)
5440 /* For member templates */
5441 return TREE_CODE (ot) == TREE_VEC && comp_template_args (ot, nt);
5442 else if (PACK_EXPANSION_P (ot))
5443 return PACK_EXPANSION_P (nt)
5444 && template_args_equal (PACK_EXPANSION_PATTERN (ot),
5445 PACK_EXPANSION_PATTERN (nt));
5446 else if (ARGUMENT_PACK_P (ot))
5451 if (!ARGUMENT_PACK_P (nt))
5454 opack = ARGUMENT_PACK_ARGS (ot);
5455 npack = ARGUMENT_PACK_ARGS (nt);
5456 len = TREE_VEC_LENGTH (opack);
5457 if (TREE_VEC_LENGTH (npack) != len)
5459 for (i = 0; i < len; ++i)
5460 if (!template_args_equal (TREE_VEC_ELT (opack, i),
5461 TREE_VEC_ELT (npack, i)))
5465 else if (TYPE_P (nt))
5466 return TYPE_P (ot) && same_type_p (ot, nt);
5467 else if (TREE_CODE (ot) == TREE_VEC || TYPE_P (ot))
5470 return cp_tree_equal (ot, nt);
5473 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
5474 of template arguments. Returns 0 otherwise. */
5477 comp_template_args (tree oldargs, tree newargs)
5481 if (TREE_VEC_LENGTH (oldargs) != TREE_VEC_LENGTH (newargs))
5484 for (i = 0; i < TREE_VEC_LENGTH (oldargs); ++i)
5486 tree nt = TREE_VEC_ELT (newargs, i);
5487 tree ot = TREE_VEC_ELT (oldargs, i);
5489 if (! template_args_equal (ot, nt))
5496 add_pending_template (tree d)
5498 tree ti = (TYPE_P (d)
5499 ? CLASSTYPE_TEMPLATE_INFO (d)
5500 : DECL_TEMPLATE_INFO (d));
5501 struct pending_template *pt;
5504 if (TI_PENDING_TEMPLATE_FLAG (ti))
5507 /* We are called both from instantiate_decl, where we've already had a
5508 tinst_level pushed, and instantiate_template, where we haven't.
5510 level = !current_tinst_level || current_tinst_level->decl != d;
5513 push_tinst_level (d);
5515 pt = GGC_NEW (struct pending_template);
5517 pt->tinst = current_tinst_level;
5518 if (last_pending_template)
5519 last_pending_template->next = pt;
5521 pending_templates = pt;
5523 last_pending_template = pt;
5525 TI_PENDING_TEMPLATE_FLAG (ti) = 1;
5532 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
5533 ARGLIST. Valid choices for FNS are given in the cp-tree.def
5534 documentation for TEMPLATE_ID_EXPR. */
5537 lookup_template_function (tree fns, tree arglist)
5541 if (fns == error_mark_node || arglist == error_mark_node)
5542 return error_mark_node;
5544 gcc_assert (!arglist || TREE_CODE (arglist) == TREE_VEC);
5545 gcc_assert (fns && (is_overloaded_fn (fns)
5546 || TREE_CODE (fns) == IDENTIFIER_NODE));
5548 if (BASELINK_P (fns))
5550 BASELINK_FUNCTIONS (fns) = build2 (TEMPLATE_ID_EXPR,
5552 BASELINK_FUNCTIONS (fns),
5557 type = TREE_TYPE (fns);
5558 if (TREE_CODE (fns) == OVERLOAD || !type)
5559 type = unknown_type_node;
5561 return build2 (TEMPLATE_ID_EXPR, type, fns, arglist);
5564 /* Within the scope of a template class S<T>, the name S gets bound
5565 (in build_self_reference) to a TYPE_DECL for the class, not a
5566 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
5567 or one of its enclosing classes, and that type is a template,
5568 return the associated TEMPLATE_DECL. Otherwise, the original
5569 DECL is returned. */
5572 maybe_get_template_decl_from_type_decl (tree decl)
5574 return (decl != NULL_TREE
5575 && TREE_CODE (decl) == TYPE_DECL
5576 && DECL_ARTIFICIAL (decl)
5577 && CLASS_TYPE_P (TREE_TYPE (decl))
5578 && CLASSTYPE_TEMPLATE_INFO (TREE_TYPE (decl)))
5579 ? CLASSTYPE_TI_TEMPLATE (TREE_TYPE (decl)) : decl;
5582 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
5583 parameters, find the desired type.
5585 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
5587 IN_DECL, if non-NULL, is the template declaration we are trying to
5590 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
5591 the class we are looking up.
5593 Issue error and warning messages under control of COMPLAIN.
5595 If the template class is really a local class in a template
5596 function, then the FUNCTION_CONTEXT is the function in which it is
5599 ??? Note that this function is currently called *twice* for each
5600 template-id: the first time from the parser, while creating the
5601 incomplete type (finish_template_type), and the second type during the
5602 real instantiation (instantiate_template_class). This is surely something
5603 that we want to avoid. It also causes some problems with argument
5604 coercion (see convert_nontype_argument for more information on this). */
5607 lookup_template_class (tree d1,
5612 tsubst_flags_t complain)
5614 tree templ = NULL_TREE, parmlist;
5617 timevar_push (TV_NAME_LOOKUP);
5619 if (TREE_CODE (d1) == IDENTIFIER_NODE)
5621 tree value = innermost_non_namespace_value (d1);
5622 if (value && DECL_TEMPLATE_TEMPLATE_PARM_P (value))
5627 push_decl_namespace (context);
5628 templ = lookup_name (d1);
5629 templ = maybe_get_template_decl_from_type_decl (templ);
5631 pop_decl_namespace ();
5634 context = DECL_CONTEXT (templ);
5636 else if (TREE_CODE (d1) == TYPE_DECL && MAYBE_CLASS_TYPE_P (TREE_TYPE (d1)))
5638 tree type = TREE_TYPE (d1);
5640 /* If we are declaring a constructor, say A<T>::A<T>, we will get
5641 an implicit typename for the second A. Deal with it. */
5642 if (TREE_CODE (type) == TYPENAME_TYPE && TREE_TYPE (type))
5643 type = TREE_TYPE (type);
5645 if (CLASSTYPE_TEMPLATE_INFO (type))
5647 templ = CLASSTYPE_TI_TEMPLATE (type);
5648 d1 = DECL_NAME (templ);
5651 else if (TREE_CODE (d1) == ENUMERAL_TYPE
5652 || (TYPE_P (d1) && MAYBE_CLASS_TYPE_P (d1)))
5654 templ = TYPE_TI_TEMPLATE (d1);
5655 d1 = DECL_NAME (templ);
5657 else if (TREE_CODE (d1) == TEMPLATE_DECL
5658 && DECL_TEMPLATE_RESULT (d1)
5659 && TREE_CODE (DECL_TEMPLATE_RESULT (d1)) == TYPE_DECL)
5662 d1 = DECL_NAME (templ);
5663 context = DECL_CONTEXT (templ);
5666 /* Issue an error message if we didn't find a template. */
5669 if (complain & tf_error)
5670 error ("%qT is not a template", d1);
5671 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
5674 if (TREE_CODE (templ) != TEMPLATE_DECL
5675 /* Make sure it's a user visible template, if it was named by
5677 || ((complain & tf_user) && !DECL_TEMPLATE_PARM_P (templ)
5678 && !PRIMARY_TEMPLATE_P (templ)))
5680 if (complain & tf_error)
5682 error ("non-template type %qT used as a template", d1);
5684 error ("for template declaration %q+D", in_decl);
5686 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
5689 complain &= ~tf_user;
5691 if (DECL_TEMPLATE_TEMPLATE_PARM_P (templ))
5693 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
5694 template arguments */
5700 parmlist = DECL_INNERMOST_TEMPLATE_PARMS (templ);
5702 /* Consider an example where a template template parameter declared as
5704 template <class T, class U = std::allocator<T> > class TT
5706 The template parameter level of T and U are one level larger than
5707 of TT. To proper process the default argument of U, say when an
5708 instantiation `TT<int>' is seen, we need to build the full
5709 arguments containing {int} as the innermost level. Outer levels,
5710 available when not appearing as default template argument, can be
5711 obtained from the arguments of the enclosing template.
5713 Suppose that TT is later substituted with std::vector. The above
5714 instantiation is `TT<int, std::allocator<T> >' with TT at
5715 level 1, and T at level 2, while the template arguments at level 1
5716 becomes {std::vector} and the inner level 2 is {int}. */
5718 outer = DECL_CONTEXT (templ);
5720 outer = TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (outer)));
5721 else if (current_template_parms)
5722 /* This is an argument of the current template, so we haven't set
5723 DECL_CONTEXT yet. */
5724 outer = current_template_args ();
5727 arglist = add_to_template_args (outer, arglist);
5729 arglist2 = coerce_template_parms (parmlist, arglist, templ,
5731 /*require_all_args=*/true,
5732 /*use_default_args=*/true);
5733 if (arglist2 == error_mark_node
5734 || (!uses_template_parms (arglist2)
5735 && check_instantiated_args (templ, arglist2, complain)))
5736 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
5738 parm = bind_template_template_parm (TREE_TYPE (templ), arglist2);
5739 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, parm);
5743 tree template_type = TREE_TYPE (templ);
5746 tree found = NULL_TREE;
5749 int is_partial_instantiation;
5751 gen_tmpl = most_general_template (templ);
5752 parmlist = DECL_TEMPLATE_PARMS (gen_tmpl);
5753 parm_depth = TMPL_PARMS_DEPTH (parmlist);
5754 arg_depth = TMPL_ARGS_DEPTH (arglist);
5756 if (arg_depth == 1 && parm_depth > 1)
5758 /* We've been given an incomplete set of template arguments.
5761 template <class T> struct S1 {
5762 template <class U> struct S2 {};
5763 template <class U> struct S2<U*> {};
5766 we will be called with an ARGLIST of `U*', but the
5767 TEMPLATE will be `template <class T> template
5768 <class U> struct S1<T>::S2'. We must fill in the missing
5771 = add_outermost_template_args (TYPE_TI_ARGS (TREE_TYPE (templ)),
5773 arg_depth = TMPL_ARGS_DEPTH (arglist);
5776 /* Now we should have enough arguments. */
5777 gcc_assert (parm_depth == arg_depth);
5779 /* From here on, we're only interested in the most general
5783 /* Calculate the BOUND_ARGS. These will be the args that are
5784 actually tsubst'd into the definition to create the
5788 /* We have multiple levels of arguments to coerce, at once. */
5790 int saved_depth = TMPL_ARGS_DEPTH (arglist);
5792 tree bound_args = make_tree_vec (parm_depth);
5794 for (i = saved_depth,
5795 t = DECL_TEMPLATE_PARMS (templ);
5796 i > 0 && t != NULL_TREE;
5797 --i, t = TREE_CHAIN (t))
5799 tree a = coerce_template_parms (TREE_VALUE (t),
5802 /*require_all_args=*/true,
5803 /*use_default_args=*/true);
5805 /* Don't process further if one of the levels fails. */
5806 if (a == error_mark_node)
5808 /* Restore the ARGLIST to its full size. */
5809 TREE_VEC_LENGTH (arglist) = saved_depth;
5810 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
5813 SET_TMPL_ARGS_LEVEL (bound_args, i, a);
5815 /* We temporarily reduce the length of the ARGLIST so
5816 that coerce_template_parms will see only the arguments
5817 corresponding to the template parameters it is
5819 TREE_VEC_LENGTH (arglist)--;
5822 /* Restore the ARGLIST to its full size. */
5823 TREE_VEC_LENGTH (arglist) = saved_depth;
5825 arglist = bound_args;
5829 = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parmlist),
5830 INNERMOST_TEMPLATE_ARGS (arglist),
5833 /*require_all_args=*/true,
5834 /*use_default_args=*/true);
5836 if (arglist == error_mark_node)
5837 /* We were unable to bind the arguments. */
5838 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
5840 /* In the scope of a template class, explicit references to the
5841 template class refer to the type of the template, not any
5842 instantiation of it. For example, in:
5844 template <class T> class C { void f(C<T>); }
5846 the `C<T>' is just the same as `C'. Outside of the
5847 class, however, such a reference is an instantiation. */
5849 || !PRIMARY_TEMPLATE_P (templ)
5850 || currently_open_class (template_type))
5851 /* comp_template_args is expensive, check it last. */
5852 && comp_template_args (TYPE_TI_ARGS (template_type),
5854 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, template_type);
5856 /* If we already have this specialization, return it. */
5857 found = retrieve_specialization (templ, arglist,
5858 /*class_specializations_p=*/false);
5860 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, found);
5862 /* This type is a "partial instantiation" if any of the template
5863 arguments still involve template parameters. Note that we set
5864 IS_PARTIAL_INSTANTIATION for partial specializations as
5866 is_partial_instantiation = uses_template_parms (arglist);
5868 /* If the deduced arguments are invalid, then the binding
5870 if (!is_partial_instantiation
5871 && check_instantiated_args (templ,
5872 INNERMOST_TEMPLATE_ARGS (arglist),
5874 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
5876 if (!is_partial_instantiation
5877 && !PRIMARY_TEMPLATE_P (templ)
5878 && TREE_CODE (CP_DECL_CONTEXT (templ)) == NAMESPACE_DECL)
5880 found = xref_tag_from_type (TREE_TYPE (templ),
5882 /*tag_scope=*/ts_global);
5883 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, found);
5886 context = tsubst (DECL_CONTEXT (templ), arglist,
5889 context = global_namespace;
5891 /* Create the type. */
5892 if (TREE_CODE (template_type) == ENUMERAL_TYPE)
5894 if (!is_partial_instantiation)
5896 set_current_access_from_decl (TYPE_NAME (template_type));
5897 t = start_enum (TYPE_IDENTIFIER (template_type),
5898 tsubst (ENUM_UNDERLYING_TYPE (template_type),
5899 arglist, complain, in_decl),
5900 SCOPED_ENUM_P (template_type));
5904 /* We don't want to call start_enum for this type, since
5905 the values for the enumeration constants may involve
5906 template parameters. And, no one should be interested
5907 in the enumeration constants for such a type. */
5908 t = make_node (ENUMERAL_TYPE);
5909 SET_SCOPED_ENUM_P (t, SCOPED_ENUM_P (template_type));
5914 t = make_class_type (TREE_CODE (template_type));
5915 CLASSTYPE_DECLARED_CLASS (t)
5916 = CLASSTYPE_DECLARED_CLASS (template_type);
5917 SET_CLASSTYPE_IMPLICIT_INSTANTIATION (t);
5918 TYPE_FOR_JAVA (t) = TYPE_FOR_JAVA (template_type);
5920 /* A local class. Make sure the decl gets registered properly. */
5921 if (context == current_function_decl)
5922 pushtag (DECL_NAME (templ), t, /*tag_scope=*/ts_current);
5924 if (comp_template_args (CLASSTYPE_TI_ARGS (template_type), arglist))
5925 /* This instantiation is another name for the primary
5926 template type. Set the TYPE_CANONICAL field
5928 TYPE_CANONICAL (t) = template_type;
5929 else if (any_template_arguments_need_structural_equality_p (arglist))
5930 /* Some of the template arguments require structural
5931 equality testing, so this template class requires
5932 structural equality testing. */
5933 SET_TYPE_STRUCTURAL_EQUALITY (t);
5936 /* If we called start_enum or pushtag above, this information
5937 will already be set up. */
5940 TYPE_CONTEXT (t) = FROB_CONTEXT (context);
5942 type_decl = create_implicit_typedef (DECL_NAME (templ), t);
5943 DECL_CONTEXT (type_decl) = TYPE_CONTEXT (t);
5944 TYPE_STUB_DECL (t) = type_decl;
5945 DECL_SOURCE_LOCATION (type_decl)
5946 = DECL_SOURCE_LOCATION (TYPE_STUB_DECL (template_type));
5949 type_decl = TYPE_NAME (t);
5951 TREE_PRIVATE (type_decl)
5952 = TREE_PRIVATE (TYPE_STUB_DECL (template_type));
5953 TREE_PROTECTED (type_decl)
5954 = TREE_PROTECTED (TYPE_STUB_DECL (template_type));
5955 if (CLASSTYPE_VISIBILITY_SPECIFIED (template_type))
5957 DECL_VISIBILITY_SPECIFIED (type_decl) = 1;
5958 DECL_VISIBILITY (type_decl) = CLASSTYPE_VISIBILITY (template_type);
5961 /* Set up the template information. We have to figure out which
5962 template is the immediate parent if this is a full
5964 if (parm_depth == 1 || is_partial_instantiation
5965 || !PRIMARY_TEMPLATE_P (templ))
5966 /* This case is easy; there are no member templates involved. */
5970 /* This is a full instantiation of a member template. Look
5971 for a partial instantiation of which this is an instance. */
5973 for (found = DECL_TEMPLATE_INSTANTIATIONS (templ);
5974 found; found = TREE_CHAIN (found))
5977 tree tmpl = CLASSTYPE_TI_TEMPLATE (TREE_VALUE (found));
5979 /* We only want partial instantiations, here, not
5980 specializations or full instantiations. */
5981 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_VALUE (found))
5982 || !uses_template_parms (TREE_VALUE (found)))
5985 /* Temporarily reduce by one the number of levels in the
5986 ARGLIST and in FOUND so as to avoid comparing the
5987 last set of arguments. */
5988 TREE_VEC_LENGTH (arglist)--;
5989 TREE_VEC_LENGTH (TREE_PURPOSE (found)) --;
5991 /* See if the arguments match. If they do, then TMPL is
5992 the partial instantiation we want. */
5993 success = comp_template_args (TREE_PURPOSE (found), arglist);
5995 /* Restore the argument vectors to their full size. */
5996 TREE_VEC_LENGTH (arglist)++;
5997 TREE_VEC_LENGTH (TREE_PURPOSE (found))++;
6008 /* There was no partial instantiation. This happens
6009 where C<T> is a member template of A<T> and it's used
6012 template <typename T> struct B { A<T>::C<int> m; };
6015 Create the partial instantiation.
6017 TREE_VEC_LENGTH (arglist)--;
6018 found = tsubst (templ, arglist, complain, NULL_TREE);
6019 TREE_VEC_LENGTH (arglist)++;
6023 SET_TYPE_TEMPLATE_INFO (t, tree_cons (found, arglist, NULL_TREE));
6024 DECL_TEMPLATE_INSTANTIATIONS (templ)
6025 = tree_cons (arglist, t,
6026 DECL_TEMPLATE_INSTANTIATIONS (templ));
6028 if (TREE_CODE (t) == ENUMERAL_TYPE
6029 && !is_partial_instantiation)
6030 /* Now that the type has been registered on the instantiations
6031 list, we set up the enumerators. Because the enumeration
6032 constants may involve the enumeration type itself, we make
6033 sure to register the type first, and then create the
6034 constants. That way, doing tsubst_expr for the enumeration
6035 constants won't result in recursive calls here; we'll find
6036 the instantiation and exit above. */
6037 tsubst_enum (template_type, t, arglist);
6039 if (is_partial_instantiation)
6040 /* If the type makes use of template parameters, the
6041 code that generates debugging information will crash. */
6042 DECL_IGNORED_P (TYPE_STUB_DECL (t)) = 1;
6044 /* Possibly limit visibility based on template args. */
6045 TREE_PUBLIC (type_decl) = 1;
6046 determine_visibility (type_decl);
6048 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, t);
6050 timevar_pop (TV_NAME_LOOKUP);
6057 /* True when we should also visit template parameters that occur in
6058 non-deduced contexts. */
6059 bool include_nondeduced_p;
6060 struct pointer_set_t *visited;
6063 /* Called from for_each_template_parm via walk_tree. */
6066 for_each_template_parm_r (tree *tp, int *walk_subtrees, void *d)
6069 struct pair_fn_data *pfd = (struct pair_fn_data *) d;
6070 tree_fn_t fn = pfd->fn;
6071 void *data = pfd->data;
6074 && (pfd->include_nondeduced_p || TREE_CODE (t) != TYPENAME_TYPE)
6075 && for_each_template_parm (TYPE_CONTEXT (t), fn, data, pfd->visited,
6076 pfd->include_nondeduced_p))
6077 return error_mark_node;
6079 switch (TREE_CODE (t))
6082 if (TYPE_PTRMEMFUNC_P (t))
6088 if (!TYPE_TEMPLATE_INFO (t))
6090 else if (for_each_template_parm (TREE_VALUE (TYPE_TEMPLATE_INFO (t)),
6091 fn, data, pfd->visited,
6092 pfd->include_nondeduced_p))
6093 return error_mark_node;
6097 if (for_each_template_parm (TYPE_MIN_VALUE (t),
6098 fn, data, pfd->visited,
6099 pfd->include_nondeduced_p)
6100 || for_each_template_parm (TYPE_MAX_VALUE (t),
6101 fn, data, pfd->visited,
6102 pfd->include_nondeduced_p))
6103 return error_mark_node;
6107 /* Since we're not going to walk subtrees, we have to do this
6109 if (for_each_template_parm (TYPE_METHOD_BASETYPE (t), fn, data,
6110 pfd->visited, pfd->include_nondeduced_p))
6111 return error_mark_node;
6115 /* Check the return type. */
6116 if (for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
6117 pfd->include_nondeduced_p))
6118 return error_mark_node;
6120 /* Check the parameter types. Since default arguments are not
6121 instantiated until they are needed, the TYPE_ARG_TYPES may
6122 contain expressions that involve template parameters. But,
6123 no-one should be looking at them yet. And, once they're
6124 instantiated, they don't contain template parameters, so
6125 there's no point in looking at them then, either. */
6129 for (parm = TYPE_ARG_TYPES (t); parm; parm = TREE_CHAIN (parm))
6130 if (for_each_template_parm (TREE_VALUE (parm), fn, data,
6131 pfd->visited, pfd->include_nondeduced_p))
6132 return error_mark_node;
6134 /* Since we've already handled the TYPE_ARG_TYPES, we don't
6135 want walk_tree walking into them itself. */
6141 if (pfd->include_nondeduced_p
6142 && for_each_template_parm (TYPE_FIELDS (t), fn, data,
6144 pfd->include_nondeduced_p))
6145 return error_mark_node;
6150 if (DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t)
6151 && for_each_template_parm (DECL_TI_ARGS (t), fn, data,
6152 pfd->visited, pfd->include_nondeduced_p))
6153 return error_mark_node;
6158 if (TREE_CODE (t) == CONST_DECL && DECL_TEMPLATE_PARM_P (t)
6159 && for_each_template_parm (DECL_INITIAL (t), fn, data,
6160 pfd->visited, pfd->include_nondeduced_p))
6161 return error_mark_node;
6162 if (DECL_CONTEXT (t)
6163 && pfd->include_nondeduced_p
6164 && for_each_template_parm (DECL_CONTEXT (t), fn, data,
6165 pfd->visited, pfd->include_nondeduced_p))
6166 return error_mark_node;
6169 case BOUND_TEMPLATE_TEMPLATE_PARM:
6170 /* Record template parameters such as `T' inside `TT<T>'. */
6171 if (for_each_template_parm (TYPE_TI_ARGS (t), fn, data, pfd->visited,
6172 pfd->include_nondeduced_p))
6173 return error_mark_node;
6176 case TEMPLATE_TEMPLATE_PARM:
6177 case TEMPLATE_TYPE_PARM:
6178 case TEMPLATE_PARM_INDEX:
6179 if (fn && (*fn)(t, data))
6180 return error_mark_node;
6182 return error_mark_node;
6186 /* A template template parameter is encountered. */
6187 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t)
6188 && for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
6189 pfd->include_nondeduced_p))
6190 return error_mark_node;
6192 /* Already substituted template template parameter */
6198 || for_each_template_parm (TYPENAME_TYPE_FULLNAME (t), fn,
6200 pfd->include_nondeduced_p))
6201 return error_mark_node;
6205 if (TREE_TYPE (t) && TYPE_PTRMEMFUNC_P (TREE_TYPE (t))
6206 && pfd->include_nondeduced_p
6207 && for_each_template_parm (TYPE_PTRMEMFUNC_FN_TYPE
6208 (TREE_TYPE (t)), fn, data,
6209 pfd->visited, pfd->include_nondeduced_p))
6210 return error_mark_node;
6215 /* If there's no type, then this thing must be some expression
6216 involving template parameters. */
6217 if (!fn && !TREE_TYPE (t))
6218 return error_mark_node;
6223 case REINTERPRET_CAST_EXPR:
6224 case CONST_CAST_EXPR:
6225 case STATIC_CAST_EXPR:
6226 case DYNAMIC_CAST_EXPR:
6230 case PSEUDO_DTOR_EXPR:
6232 return error_mark_node;
6239 /* We didn't find any template parameters we liked. */
6243 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
6244 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
6245 call FN with the parameter and the DATA.
6246 If FN returns nonzero, the iteration is terminated, and
6247 for_each_template_parm returns 1. Otherwise, the iteration
6248 continues. If FN never returns a nonzero value, the value
6249 returned by for_each_template_parm is 0. If FN is NULL, it is
6250 considered to be the function which always returns 1.
6252 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
6253 parameters that occur in non-deduced contexts. When false, only
6254 visits those template parameters that can be deduced. */
6257 for_each_template_parm (tree t, tree_fn_t fn, void* data,
6258 struct pointer_set_t *visited,
6259 bool include_nondeduced_p)
6261 struct pair_fn_data pfd;
6267 pfd.include_nondeduced_p = include_nondeduced_p;
6269 /* Walk the tree. (Conceptually, we would like to walk without
6270 duplicates, but for_each_template_parm_r recursively calls
6271 for_each_template_parm, so we would need to reorganize a fair
6272 bit to use walk_tree_without_duplicates, so we keep our own
6275 pfd.visited = visited;
6277 pfd.visited = pointer_set_create ();
6278 result = cp_walk_tree (&t,
6279 for_each_template_parm_r,
6281 pfd.visited) != NULL_TREE;
6286 pointer_set_destroy (pfd.visited);
6293 /* Returns true if T depends on any template parameter. */
6296 uses_template_parms (tree t)
6299 int saved_processing_template_decl;
6301 saved_processing_template_decl = processing_template_decl;
6302 if (!saved_processing_template_decl)
6303 processing_template_decl = 1;
6305 dependent_p = dependent_type_p (t);
6306 else if (TREE_CODE (t) == TREE_VEC)
6307 dependent_p = any_dependent_template_arguments_p (t);
6308 else if (TREE_CODE (t) == TREE_LIST)
6309 dependent_p = (uses_template_parms (TREE_VALUE (t))
6310 || uses_template_parms (TREE_CHAIN (t)));
6311 else if (TREE_CODE (t) == TYPE_DECL)
6312 dependent_p = dependent_type_p (TREE_TYPE (t));
6315 || TREE_CODE (t) == TEMPLATE_PARM_INDEX
6316 || TREE_CODE (t) == OVERLOAD
6317 || TREE_CODE (t) == BASELINK
6318 || TREE_CODE (t) == IDENTIFIER_NODE
6319 || TREE_CODE (t) == TRAIT_EXPR
6320 || TREE_CODE (t) == CONSTRUCTOR
6321 || CONSTANT_CLASS_P (t))
6322 dependent_p = (type_dependent_expression_p (t)
6323 || value_dependent_expression_p (t));
6326 gcc_assert (t == error_mark_node);
6327 dependent_p = false;
6330 processing_template_decl = saved_processing_template_decl;
6335 /* Returns true if T depends on any template parameter with level LEVEL. */
6338 uses_template_parms_level (tree t, int level)
6340 return for_each_template_parm (t, template_parm_this_level_p, &level, NULL,
6341 /*include_nondeduced_p=*/true);
6344 static int tinst_depth;
6345 extern int max_tinst_depth;
6346 #ifdef GATHER_STATISTICS
6349 static int tinst_level_tick;
6350 static int last_template_error_tick;
6352 /* We're starting to instantiate D; record the template instantiation context
6353 for diagnostics and to restore it later. */
6356 push_tinst_level (tree d)
6358 struct tinst_level *new_level;
6360 if (tinst_depth >= max_tinst_depth)
6362 /* If the instantiation in question still has unbound template parms,
6363 we don't really care if we can't instantiate it, so just return.
6364 This happens with base instantiation for implicit `typename'. */
6365 if (uses_template_parms (d))
6368 last_template_error_tick = tinst_level_tick;
6369 error ("template instantiation depth exceeds maximum of %d (use "
6370 "-ftemplate-depth-NN to increase the maximum) instantiating %qD",
6371 max_tinst_depth, d);
6373 print_instantiation_context ();
6378 new_level = GGC_NEW (struct tinst_level);
6379 new_level->decl = d;
6380 new_level->locus = input_location;
6381 new_level->in_system_header_p = in_system_header;
6382 new_level->next = current_tinst_level;
6383 current_tinst_level = new_level;
6386 #ifdef GATHER_STATISTICS
6387 if (tinst_depth > depth_reached)
6388 depth_reached = tinst_depth;
6395 /* We're done instantiating this template; return to the instantiation
6399 pop_tinst_level (void)
6401 /* Restore the filename and line number stashed away when we started
6402 this instantiation. */
6403 input_location = current_tinst_level->locus;
6404 current_tinst_level = current_tinst_level->next;
6409 /* We're instantiating a deferred template; restore the template
6410 instantiation context in which the instantiation was requested, which
6411 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
6414 reopen_tinst_level (struct tinst_level *level)
6416 struct tinst_level *t;
6419 for (t = level; t; t = t->next)
6422 current_tinst_level = level;
6427 /* Returns the TINST_LEVEL which gives the original instantiation
6430 struct tinst_level *
6431 outermost_tinst_level (void)
6433 struct tinst_level *level = current_tinst_level;
6436 level = level->next;
6440 /* Returns TRUE if PARM is a parameter of the template TEMPL. */
6443 parameter_of_template_p (tree parm, tree templ)
6448 if (!parm || !templ)
6451 gcc_assert (DECL_TEMPLATE_PARM_P (parm));
6452 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
6454 parms = DECL_TEMPLATE_PARMS (templ);
6455 parms = INNERMOST_TEMPLATE_PARMS (parms);
6457 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
6458 if (parm == TREE_VALUE (TREE_VEC_ELT (parms, i)))
6464 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
6465 vector of template arguments, as for tsubst.
6467 Returns an appropriate tsubst'd friend declaration. */
6470 tsubst_friend_function (tree decl, tree args)
6474 if (TREE_CODE (decl) == FUNCTION_DECL
6475 && DECL_TEMPLATE_INSTANTIATION (decl)
6476 && TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
6477 /* This was a friend declared with an explicit template
6478 argument list, e.g.:
6482 to indicate that f was a template instantiation, not a new
6483 function declaration. Now, we have to figure out what
6484 instantiation of what template. */
6486 tree template_id, arglist, fns;
6489 tree ns = decl_namespace_context (TYPE_MAIN_DECL (current_class_type));
6491 /* Friend functions are looked up in the containing namespace scope.
6492 We must enter that scope, to avoid finding member functions of the
6493 current class with same name. */
6494 push_nested_namespace (ns);
6495 fns = tsubst_expr (DECL_TI_TEMPLATE (decl), args,
6496 tf_warning_or_error, NULL_TREE,
6497 /*integral_constant_expression_p=*/false);
6498 pop_nested_namespace (ns);
6499 arglist = tsubst (DECL_TI_ARGS (decl), args,
6500 tf_warning_or_error, NULL_TREE);
6501 template_id = lookup_template_function (fns, arglist);
6503 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
6504 tmpl = determine_specialization (template_id, new_friend,
6506 /*need_member_template=*/0,
6507 TREE_VEC_LENGTH (args),
6509 return instantiate_template (tmpl, new_args, tf_error);
6512 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
6514 /* The NEW_FRIEND will look like an instantiation, to the
6515 compiler, but is not an instantiation from the point of view of
6516 the language. For example, we might have had:
6518 template <class T> struct S {
6519 template <class U> friend void f(T, U);
6522 Then, in S<int>, template <class U> void f(int, U) is not an
6523 instantiation of anything. */
6524 if (new_friend == error_mark_node)
6525 return error_mark_node;
6527 DECL_USE_TEMPLATE (new_friend) = 0;
6528 if (TREE_CODE (decl) == TEMPLATE_DECL)
6530 DECL_USE_TEMPLATE (DECL_TEMPLATE_RESULT (new_friend)) = 0;
6531 DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (new_friend))
6532 = DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (decl));
6535 /* The mangled name for the NEW_FRIEND is incorrect. The function
6536 is not a template instantiation and should not be mangled like
6537 one. Therefore, we forget the mangling here; we'll recompute it
6538 later if we need it. */
6539 if (TREE_CODE (new_friend) != TEMPLATE_DECL)
6541 SET_DECL_RTL (new_friend, NULL_RTX);
6542 SET_DECL_ASSEMBLER_NAME (new_friend, NULL_TREE);
6545 if (DECL_NAMESPACE_SCOPE_P (new_friend))
6548 tree new_friend_template_info;
6549 tree new_friend_result_template_info;
6551 int new_friend_is_defn;
6553 /* We must save some information from NEW_FRIEND before calling
6554 duplicate decls since that function will free NEW_FRIEND if
6556 new_friend_template_info = DECL_TEMPLATE_INFO (new_friend);
6557 new_friend_is_defn =
6558 (DECL_INITIAL (DECL_TEMPLATE_RESULT
6559 (template_for_substitution (new_friend)))
6561 if (TREE_CODE (new_friend) == TEMPLATE_DECL)
6563 /* This declaration is a `primary' template. */
6564 DECL_PRIMARY_TEMPLATE (new_friend) = new_friend;
6566 new_friend_result_template_info
6567 = DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (new_friend));
6570 new_friend_result_template_info = NULL_TREE;
6572 /* Make the init_value nonzero so pushdecl knows this is a defn. */
6573 if (new_friend_is_defn)
6574 DECL_INITIAL (new_friend) = error_mark_node;
6576 /* Inside pushdecl_namespace_level, we will push into the
6577 current namespace. However, the friend function should go
6578 into the namespace of the template. */
6579 ns = decl_namespace_context (new_friend);
6580 push_nested_namespace (ns);
6581 old_decl = pushdecl_namespace_level (new_friend, /*is_friend=*/true);
6582 pop_nested_namespace (ns);
6584 if (old_decl == error_mark_node)
6585 return error_mark_node;
6587 if (old_decl != new_friend)
6589 /* This new friend declaration matched an existing
6590 declaration. For example, given:
6592 template <class T> void f(T);
6593 template <class U> class C {
6594 template <class T> friend void f(T) {}
6597 the friend declaration actually provides the definition
6598 of `f', once C has been instantiated for some type. So,
6599 old_decl will be the out-of-class template declaration,
6600 while new_friend is the in-class definition.
6602 But, if `f' was called before this point, the
6603 instantiation of `f' will have DECL_TI_ARGS corresponding
6604 to `T' but not to `U', references to which might appear
6605 in the definition of `f'. Previously, the most general
6606 template for an instantiation of `f' was the out-of-class
6607 version; now it is the in-class version. Therefore, we
6608 run through all specialization of `f', adding to their
6609 DECL_TI_ARGS appropriately. In particular, they need a
6610 new set of outer arguments, corresponding to the
6611 arguments for this class instantiation.
6613 The same situation can arise with something like this:
6616 template <class T> class C {
6620 when `C<int>' is instantiated. Now, `f(int)' is defined
6623 if (!new_friend_is_defn)
6624 /* On the other hand, if the in-class declaration does
6625 *not* provide a definition, then we don't want to alter
6626 existing definitions. We can just leave everything
6631 /* Overwrite whatever template info was there before, if
6632 any, with the new template information pertaining to
6634 DECL_TEMPLATE_INFO (old_decl) = new_friend_template_info;
6636 if (TREE_CODE (old_decl) != TEMPLATE_DECL)
6637 reregister_specialization (new_friend,
6638 most_general_template (old_decl),
6643 tree new_friend_args;
6645 DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (old_decl))
6646 = new_friend_result_template_info;
6648 new_friend_args = TI_ARGS (new_friend_template_info);
6649 for (t = DECL_TEMPLATE_SPECIALIZATIONS (old_decl);
6653 tree spec = TREE_VALUE (t);
6656 = add_outermost_template_args (new_friend_args,
6657 DECL_TI_ARGS (spec));
6660 /* Now, since specializations are always supposed to
6661 hang off of the most general template, we must move
6663 t = most_general_template (old_decl);
6666 DECL_TEMPLATE_SPECIALIZATIONS (t)
6667 = chainon (DECL_TEMPLATE_SPECIALIZATIONS (t),
6668 DECL_TEMPLATE_SPECIALIZATIONS (old_decl));
6669 DECL_TEMPLATE_SPECIALIZATIONS (old_decl) = NULL_TREE;
6674 /* The information from NEW_FRIEND has been merged into OLD_DECL
6675 by duplicate_decls. */
6676 new_friend = old_decl;
6681 tree context = DECL_CONTEXT (new_friend);
6685 template <class T> class C {
6686 template <class U> friend void C1<U>::f (); // case 1
6687 friend void C2<T>::f (); // case 2
6689 we only need to make sure CONTEXT is a complete type for
6690 case 2. To distinguish between the two cases, we note that
6691 CONTEXT of case 1 remains dependent type after tsubst while
6692 this isn't true for case 2. */
6693 ++processing_template_decl;
6694 dependent_p = dependent_type_p (context);
6695 --processing_template_decl;
6698 && !complete_type_or_else (context, NULL_TREE))
6699 return error_mark_node;
6701 if (COMPLETE_TYPE_P (context))
6703 /* Check to see that the declaration is really present, and,
6704 possibly obtain an improved declaration. */
6705 tree fn = check_classfn (context,
6706 new_friend, NULL_TREE);
6716 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
6717 template arguments, as for tsubst.
6719 Returns an appropriate tsubst'd friend type or error_mark_node on
6723 tsubst_friend_class (tree friend_tmpl, tree args)
6729 context = DECL_CONTEXT (friend_tmpl);
6733 if (TREE_CODE (context) == NAMESPACE_DECL)
6734 push_nested_namespace (context);
6736 push_nested_class (tsubst (context, args, tf_none, NULL_TREE));
6739 /* Look for a class template declaration. We look for hidden names
6740 because two friend declarations of the same template are the
6741 same. For example, in:
6744 template <typename> friend class F;
6746 template <typename> struct B {
6747 template <typename> friend class F;
6750 both F templates are the same. */
6751 tmpl = lookup_name_real (DECL_NAME (friend_tmpl), 0, 0,
6752 /*block_p=*/true, 0,
6753 LOOKUP_COMPLAIN | LOOKUP_HIDDEN);
6755 /* But, if we don't find one, it might be because we're in a
6756 situation like this:
6764 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
6765 for `S<int>', not the TEMPLATE_DECL. */
6766 if (!tmpl || !DECL_CLASS_TEMPLATE_P (tmpl))
6768 tmpl = lookup_name_prefer_type (DECL_NAME (friend_tmpl), 1);
6769 tmpl = maybe_get_template_decl_from_type_decl (tmpl);
6772 if (tmpl && DECL_CLASS_TEMPLATE_P (tmpl))
6774 /* The friend template has already been declared. Just
6775 check to see that the declarations match, and install any new
6776 default parameters. We must tsubst the default parameters,
6777 of course. We only need the innermost template parameters
6778 because that is all that redeclare_class_template will look
6780 if (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (friend_tmpl))
6781 > TMPL_ARGS_DEPTH (args))
6784 location_t saved_input_location;
6785 parms = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_tmpl),
6786 args, tf_warning_or_error);
6788 saved_input_location = input_location;
6789 input_location = DECL_SOURCE_LOCATION (friend_tmpl);
6790 redeclare_class_template (TREE_TYPE (tmpl), parms);
6791 input_location = saved_input_location;
6795 friend_type = TREE_TYPE (tmpl);
6799 /* The friend template has not already been declared. In this
6800 case, the instantiation of the template class will cause the
6801 injection of this template into the global scope. */
6802 tmpl = tsubst (friend_tmpl, args, tf_warning_or_error, NULL_TREE);
6803 if (tmpl == error_mark_node)
6804 return error_mark_node;
6806 /* The new TMPL is not an instantiation of anything, so we
6807 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
6808 the new type because that is supposed to be the corresponding
6809 template decl, i.e., TMPL. */
6810 DECL_USE_TEMPLATE (tmpl) = 0;
6811 DECL_TEMPLATE_INFO (tmpl) = NULL_TREE;
6812 CLASSTYPE_USE_TEMPLATE (TREE_TYPE (tmpl)) = 0;
6813 CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl))
6814 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl)));
6816 /* Inject this template into the global scope. */
6817 friend_type = TREE_TYPE (pushdecl_top_level_maybe_friend (tmpl, true));
6822 if (TREE_CODE (context) == NAMESPACE_DECL)
6823 pop_nested_namespace (context);
6825 pop_nested_class ();
6831 /* Returns zero if TYPE cannot be completed later due to circularity.
6832 Otherwise returns one. */
6835 can_complete_type_without_circularity (tree type)
6837 if (type == NULL_TREE || type == error_mark_node)
6839 else if (COMPLETE_TYPE_P (type))
6841 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
6842 return can_complete_type_without_circularity (TREE_TYPE (type));
6843 else if (CLASS_TYPE_P (type)
6844 && TYPE_BEING_DEFINED (TYPE_MAIN_VARIANT (type)))
6850 /* Apply any attributes which had to be deferred until instantiation
6851 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
6852 ARGS, COMPLAIN, IN_DECL are as tsubst. */
6855 apply_late_template_attributes (tree *decl_p, tree attributes, int attr_flags,
6856 tree args, tsubst_flags_t complain, tree in_decl)
6858 tree last_dep = NULL_TREE;
6862 for (t = attributes; t; t = TREE_CHAIN (t))
6863 if (ATTR_IS_DEPENDENT (t))
6866 attributes = copy_list (attributes);
6870 if (DECL_P (*decl_p))
6872 if (TREE_TYPE (*decl_p) == error_mark_node)
6874 p = &DECL_ATTRIBUTES (*decl_p);
6877 p = &TYPE_ATTRIBUTES (*decl_p);
6881 tree late_attrs = NULL_TREE;
6882 tree *q = &late_attrs;
6884 for (*p = attributes; *p; )
6887 if (ATTR_IS_DEPENDENT (t))
6889 *p = TREE_CHAIN (t);
6890 TREE_CHAIN (t) = NULL_TREE;
6891 /* If the first attribute argument is an identifier, don't
6892 pass it through tsubst. Attributes like mode, format,
6893 cleanup and several target specific attributes expect it
6896 && TREE_CODE (TREE_VALUE (t)) == TREE_LIST
6897 && TREE_VALUE (TREE_VALUE (t))
6898 && (TREE_CODE (TREE_VALUE (TREE_VALUE (t)))
6899 == IDENTIFIER_NODE))
6902 = tsubst_expr (TREE_CHAIN (TREE_VALUE (t)), args, complain,
6904 /*integral_constant_expression_p=*/false);
6905 if (chain != TREE_CHAIN (TREE_VALUE (t)))
6907 = tree_cons (NULL_TREE, TREE_VALUE (TREE_VALUE (t)),
6912 = tsubst_expr (TREE_VALUE (t), args, complain, in_decl,
6913 /*integral_constant_expression_p=*/false);
6915 q = &TREE_CHAIN (t);
6918 p = &TREE_CHAIN (t);
6921 cplus_decl_attributes (decl_p, late_attrs, attr_flags);
6925 /* Perform (or defer) access check for typedefs that were referenced
6926 from within the template TMPL code.
6927 This is a subroutine of instantiate_template and instantiate_class_template.
6928 TMPL is the template to consider and TARGS is the list of arguments of
6932 perform_typedefs_access_check (tree tmpl, tree targs)
6937 || (TREE_CODE (tmpl) != RECORD_TYPE
6938 && TREE_CODE (tmpl) != FUNCTION_DECL))
6941 for (t = get_types_needing_access_check (tmpl); t; t = TREE_CHAIN (t))
6943 tree type_decl = TREE_PURPOSE (t);
6944 tree type_scope = TREE_VALUE (t);
6946 if (!type_decl || !type_scope || !CLASS_TYPE_P (type_scope))
6949 if (uses_template_parms (type_decl))
6950 type_decl = tsubst (type_decl, targs, tf_error, NULL_TREE);
6951 if (uses_template_parms (type_scope))
6952 type_scope = tsubst (type_scope, targs, tf_error, NULL_TREE);
6954 perform_or_defer_access_check (TYPE_BINFO (type_scope),
6955 type_decl, type_decl);
6960 instantiate_class_template (tree type)
6962 tree templ, args, pattern, t, member;
6967 if (type == error_mark_node)
6968 return error_mark_node;
6970 if (TYPE_BEING_DEFINED (type)
6971 || COMPLETE_TYPE_P (type)
6972 || dependent_type_p (type))
6975 /* Figure out which template is being instantiated. */
6976 templ = most_general_template (CLASSTYPE_TI_TEMPLATE (type));
6977 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
6979 /* Determine what specialization of the original template to
6981 t = most_specialized_class (type, templ);
6982 if (t == error_mark_node)
6984 TYPE_BEING_DEFINED (type) = 1;
6985 return error_mark_node;
6989 /* This TYPE is actually an instantiation of a partial
6990 specialization. We replace the innermost set of ARGS with
6991 the arguments appropriate for substitution. For example,
6994 template <class T> struct S {};
6995 template <class T> struct S<T*> {};
6997 and supposing that we are instantiating S<int*>, ARGS will
6998 presently be {int*} -- but we need {int}. */
6999 pattern = TREE_TYPE (t);
7000 args = TREE_PURPOSE (t);
7004 pattern = TREE_TYPE (templ);
7005 args = CLASSTYPE_TI_ARGS (type);
7008 /* If the template we're instantiating is incomplete, then clearly
7009 there's nothing we can do. */
7010 if (!COMPLETE_TYPE_P (pattern))
7013 /* If we've recursively instantiated too many templates, stop. */
7014 if (! push_tinst_level (type))
7017 /* Now we're really doing the instantiation. Mark the type as in
7018 the process of being defined. */
7019 TYPE_BEING_DEFINED (type) = 1;
7021 /* We may be in the middle of deferred access check. Disable
7023 push_deferring_access_checks (dk_no_deferred);
7025 push_to_top_level ();
7027 SET_CLASSTYPE_INTERFACE_UNKNOWN (type);
7029 /* Set the input location to the most specialized template definition.
7030 This is needed if tsubsting causes an error. */
7031 typedecl = TYPE_MAIN_DECL (pattern);
7032 input_location = DECL_SOURCE_LOCATION (typedecl);
7034 TYPE_HAS_USER_CONSTRUCTOR (type) = TYPE_HAS_USER_CONSTRUCTOR (pattern);
7035 TYPE_HAS_NEW_OPERATOR (type) = TYPE_HAS_NEW_OPERATOR (pattern);
7036 TYPE_HAS_ARRAY_NEW_OPERATOR (type) = TYPE_HAS_ARRAY_NEW_OPERATOR (pattern);
7037 TYPE_GETS_DELETE (type) = TYPE_GETS_DELETE (pattern);
7038 TYPE_HAS_ASSIGN_REF (type) = TYPE_HAS_ASSIGN_REF (pattern);
7039 TYPE_HAS_CONST_ASSIGN_REF (type) = TYPE_HAS_CONST_ASSIGN_REF (pattern);
7040 TYPE_HAS_INIT_REF (type) = TYPE_HAS_INIT_REF (pattern);
7041 TYPE_HAS_CONST_INIT_REF (type) = TYPE_HAS_CONST_INIT_REF (pattern);
7042 TYPE_HAS_DEFAULT_CONSTRUCTOR (type) = TYPE_HAS_DEFAULT_CONSTRUCTOR (pattern);
7043 TYPE_HAS_CONVERSION (type) = TYPE_HAS_CONVERSION (pattern);
7044 TYPE_PACKED (type) = TYPE_PACKED (pattern);
7045 TYPE_ALIGN (type) = TYPE_ALIGN (pattern);
7046 TYPE_USER_ALIGN (type) = TYPE_USER_ALIGN (pattern);
7047 TYPE_FOR_JAVA (type) = TYPE_FOR_JAVA (pattern); /* For libjava's JArray<T> */
7048 if (ANON_AGGR_TYPE_P (pattern))
7049 SET_ANON_AGGR_TYPE_P (type);
7050 if (CLASSTYPE_VISIBILITY_SPECIFIED (pattern))
7052 CLASSTYPE_VISIBILITY_SPECIFIED (type) = 1;
7053 CLASSTYPE_VISIBILITY (type) = CLASSTYPE_VISIBILITY (pattern);
7056 pbinfo = TYPE_BINFO (pattern);
7058 /* We should never instantiate a nested class before its enclosing
7059 class; we need to look up the nested class by name before we can
7060 instantiate it, and that lookup should instantiate the enclosing
7062 gcc_assert (!DECL_CLASS_SCOPE_P (TYPE_MAIN_DECL (pattern))
7063 || COMPLETE_TYPE_P (TYPE_CONTEXT (type))
7064 || TYPE_BEING_DEFINED (TYPE_CONTEXT (type)));
7066 base_list = NULL_TREE;
7067 if (BINFO_N_BASE_BINFOS (pbinfo))
7070 tree context = TYPE_CONTEXT (type);
7074 /* We must enter the scope containing the type, as that is where
7075 the accessibility of types named in dependent bases are
7077 pushed_scope = push_scope (context ? context : global_namespace);
7079 /* Substitute into each of the bases to determine the actual
7081 for (i = 0; BINFO_BASE_ITERATE (pbinfo, i, pbase_binfo); i++)
7084 tree access = BINFO_BASE_ACCESS (pbinfo, i);
7085 tree expanded_bases = NULL_TREE;
7088 if (PACK_EXPANSION_P (BINFO_TYPE (pbase_binfo)))
7091 tsubst_pack_expansion (BINFO_TYPE (pbase_binfo),
7092 args, tf_error, NULL_TREE);
7093 if (expanded_bases == error_mark_node)
7096 len = TREE_VEC_LENGTH (expanded_bases);
7099 for (idx = 0; idx < len; idx++)
7102 /* Extract the already-expanded base class. */
7103 base = TREE_VEC_ELT (expanded_bases, idx);
7105 /* Substitute to figure out the base class. */
7106 base = tsubst (BINFO_TYPE (pbase_binfo), args, tf_error,
7109 if (base == error_mark_node)
7112 base_list = tree_cons (access, base, base_list);
7113 if (BINFO_VIRTUAL_P (pbase_binfo))
7114 TREE_TYPE (base_list) = integer_type_node;
7118 /* The list is now in reverse order; correct that. */
7119 base_list = nreverse (base_list);
7122 pop_scope (pushed_scope);
7124 /* Now call xref_basetypes to set up all the base-class
7126 xref_basetypes (type, base_list);
7128 apply_late_template_attributes (&type, TYPE_ATTRIBUTES (pattern),
7129 (int) ATTR_FLAG_TYPE_IN_PLACE,
7130 args, tf_error, NULL_TREE);
7132 /* Now that our base classes are set up, enter the scope of the
7133 class, so that name lookups into base classes, etc. will work
7134 correctly. This is precisely analogous to what we do in
7135 begin_class_definition when defining an ordinary non-template
7136 class, except we also need to push the enclosing classes. */
7137 push_nested_class (type);
7139 /* Now members are processed in the order of declaration. */
7140 for (member = CLASSTYPE_DECL_LIST (pattern);
7141 member; member = TREE_CHAIN (member))
7143 tree t = TREE_VALUE (member);
7145 if (TREE_PURPOSE (member))
7149 /* Build new CLASSTYPE_NESTED_UTDS. */
7152 bool class_template_p;
7154 class_template_p = (TREE_CODE (t) != ENUMERAL_TYPE
7155 && TYPE_LANG_SPECIFIC (t)
7156 && CLASSTYPE_IS_TEMPLATE (t));
7157 /* If the member is a class template, then -- even after
7158 substitution -- there may be dependent types in the
7159 template argument list for the class. We increment
7160 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
7161 that function will assume that no types are dependent
7162 when outside of a template. */
7163 if (class_template_p)
7164 ++processing_template_decl;
7165 newtag = tsubst (t, args, tf_error, NULL_TREE);
7166 if (class_template_p)
7167 --processing_template_decl;
7168 if (newtag == error_mark_node)
7171 if (TREE_CODE (newtag) != ENUMERAL_TYPE)
7173 tree name = TYPE_IDENTIFIER (t);
7175 if (class_template_p)
7176 /* Unfortunately, lookup_template_class sets
7177 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
7178 instantiation (i.e., for the type of a member
7179 template class nested within a template class.)
7180 This behavior is required for
7181 maybe_process_partial_specialization to work
7182 correctly, but is not accurate in this case;
7183 the TAG is not an instantiation of anything.
7184 (The corresponding TEMPLATE_DECL is an
7185 instantiation, but the TYPE is not.) */
7186 CLASSTYPE_USE_TEMPLATE (newtag) = 0;
7188 /* Now, we call pushtag to put this NEWTAG into the scope of
7189 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
7190 pushtag calling push_template_decl. We don't have to do
7191 this for enums because it will already have been done in
7194 SET_IDENTIFIER_TYPE_VALUE (name, newtag);
7195 pushtag (name, newtag, /*tag_scope=*/ts_current);
7198 else if (TREE_CODE (t) == FUNCTION_DECL
7199 || DECL_FUNCTION_TEMPLATE_P (t))
7201 /* Build new TYPE_METHODS. */
7204 if (TREE_CODE (t) == TEMPLATE_DECL)
7205 ++processing_template_decl;
7206 r = tsubst (t, args, tf_error, NULL_TREE);
7207 if (TREE_CODE (t) == TEMPLATE_DECL)
7208 --processing_template_decl;
7209 set_current_access_from_decl (r);
7210 finish_member_declaration (r);
7214 /* Build new TYPE_FIELDS. */
7215 if (TREE_CODE (t) == STATIC_ASSERT)
7218 tsubst_expr (STATIC_ASSERT_CONDITION (t), args,
7219 tf_warning_or_error, NULL_TREE,
7220 /*integral_constant_expression_p=*/true);
7221 finish_static_assert (condition,
7222 STATIC_ASSERT_MESSAGE (t),
7223 STATIC_ASSERT_SOURCE_LOCATION (t),
7226 else if (TREE_CODE (t) != CONST_DECL)
7230 /* The file and line for this declaration, to
7231 assist in error message reporting. Since we
7232 called push_tinst_level above, we don't need to
7234 input_location = DECL_SOURCE_LOCATION (t);
7236 if (TREE_CODE (t) == TEMPLATE_DECL)
7237 ++processing_template_decl;
7238 r = tsubst (t, args, tf_warning_or_error, NULL_TREE);
7239 if (TREE_CODE (t) == TEMPLATE_DECL)
7240 --processing_template_decl;
7241 if (TREE_CODE (r) == VAR_DECL)
7245 [t]he initialization (and any associated
7246 side-effects) of a static data member does
7247 not occur unless the static data member is
7248 itself used in a way that requires the
7249 definition of the static data member to
7252 Therefore, we do not substitute into the
7253 initialized for the static data member here. */
7254 finish_static_data_member_decl
7257 /*init_const_expr_p=*/false,
7258 /*asmspec_tree=*/NULL_TREE,
7260 if (DECL_INITIALIZED_IN_CLASS_P (r))
7261 check_static_variable_definition (r, TREE_TYPE (r));
7263 else if (TREE_CODE (r) == FIELD_DECL)
7265 /* Determine whether R has a valid type and can be
7266 completed later. If R is invalid, then it is
7267 replaced by error_mark_node so that it will not be
7268 added to TYPE_FIELDS. */
7269 tree rtype = TREE_TYPE (r);
7270 if (can_complete_type_without_circularity (rtype))
7271 complete_type (rtype);
7273 if (!COMPLETE_TYPE_P (rtype))
7275 cxx_incomplete_type_error (r, rtype);
7276 r = error_mark_node;
7280 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
7281 such a thing will already have been added to the field
7282 list by tsubst_enum in finish_member_declaration in the
7283 CLASSTYPE_NESTED_UTDS case above. */
7284 if (!(TREE_CODE (r) == TYPE_DECL
7285 && TREE_CODE (TREE_TYPE (r)) == ENUMERAL_TYPE
7286 && DECL_ARTIFICIAL (r)))
7288 set_current_access_from_decl (r);
7289 finish_member_declaration (r);
7296 if (TYPE_P (t) || DECL_CLASS_TEMPLATE_P (t))
7298 /* Build new CLASSTYPE_FRIEND_CLASSES. */
7300 tree friend_type = t;
7301 bool adjust_processing_template_decl = false;
7303 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
7305 /* template <class T> friend class C; */
7306 friend_type = tsubst_friend_class (friend_type, args);
7307 adjust_processing_template_decl = true;
7309 else if (TREE_CODE (friend_type) == UNBOUND_CLASS_TEMPLATE)
7311 /* template <class T> friend class C::D; */
7312 friend_type = tsubst (friend_type, args,
7313 tf_warning_or_error, NULL_TREE);
7314 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
7315 friend_type = TREE_TYPE (friend_type);
7316 adjust_processing_template_decl = true;
7318 else if (TREE_CODE (friend_type) == TYPENAME_TYPE)
7320 /* This could be either
7324 when dependent_type_p is false or
7326 template <class U> friend class T::C;
7329 friend_type = tsubst (friend_type, args,
7330 tf_warning_or_error, NULL_TREE);
7331 /* Bump processing_template_decl for correct
7332 dependent_type_p calculation. */
7333 ++processing_template_decl;
7334 if (dependent_type_p (friend_type))
7335 adjust_processing_template_decl = true;
7336 --processing_template_decl;
7338 else if (!CLASSTYPE_USE_TEMPLATE (friend_type)
7339 && hidden_name_p (TYPE_NAME (friend_type)))
7343 where C hasn't been declared yet. Let's lookup name
7344 from namespace scope directly, bypassing any name that
7345 come from dependent base class. */
7346 tree ns = decl_namespace_context (TYPE_MAIN_DECL (friend_type));
7348 /* The call to xref_tag_from_type does injection for friend
7350 push_nested_namespace (ns);
7352 xref_tag_from_type (friend_type, NULL_TREE,
7353 /*tag_scope=*/ts_current);
7354 pop_nested_namespace (ns);
7356 else if (uses_template_parms (friend_type))
7357 /* friend class C<T>; */
7358 friend_type = tsubst (friend_type, args,
7359 tf_warning_or_error, NULL_TREE);
7364 where C is already declared or
7366 friend class C<int>;
7368 We don't have to do anything in these cases. */
7370 if (adjust_processing_template_decl)
7371 /* Trick make_friend_class into realizing that the friend
7372 we're adding is a template, not an ordinary class. It's
7373 important that we use make_friend_class since it will
7374 perform some error-checking and output cross-reference
7376 ++processing_template_decl;
7378 if (friend_type != error_mark_node)
7379 make_friend_class (type, friend_type, /*complain=*/false);
7381 if (adjust_processing_template_decl)
7382 --processing_template_decl;
7386 /* Build new DECL_FRIENDLIST. */
7389 /* The file and line for this declaration, to
7390 assist in error message reporting. Since we
7391 called push_tinst_level above, we don't need to
7393 input_location = DECL_SOURCE_LOCATION (t);
7395 if (TREE_CODE (t) == TEMPLATE_DECL)
7397 ++processing_template_decl;
7398 push_deferring_access_checks (dk_no_check);
7401 r = tsubst_friend_function (t, args);
7402 add_friend (type, r, /*complain=*/false);
7403 if (TREE_CODE (t) == TEMPLATE_DECL)
7405 pop_deferring_access_checks ();
7406 --processing_template_decl;
7412 /* Set the file and line number information to whatever is given for
7413 the class itself. This puts error messages involving generated
7414 implicit functions at a predictable point, and the same point
7415 that would be used for non-template classes. */
7416 input_location = DECL_SOURCE_LOCATION (typedecl);
7418 unreverse_member_declarations (type);
7419 finish_struct_1 (type);
7420 TYPE_BEING_DEFINED (type) = 0;
7422 /* Now that the class is complete, instantiate default arguments for
7423 any member functions. We don't do this earlier because the
7424 default arguments may reference members of the class. */
7425 if (!PRIMARY_TEMPLATE_P (templ))
7426 for (t = TYPE_METHODS (type); t; t = TREE_CHAIN (t))
7427 if (TREE_CODE (t) == FUNCTION_DECL
7428 /* Implicitly generated member functions will not have template
7429 information; they are not instantiations, but instead are
7430 created "fresh" for each instantiation. */
7431 && DECL_TEMPLATE_INFO (t))
7432 tsubst_default_arguments (t);
7434 /* Some typedefs referenced from within the template code need to be access
7435 checked at template instantiation time, i.e now. These types were
7436 added to the template at parsing time. Let's get those and perform
7437 the access checks then. */
7438 perform_typedefs_access_check (pattern, args);
7439 perform_deferred_access_checks ();
7440 pop_nested_class ();
7441 pop_from_top_level ();
7442 pop_deferring_access_checks ();
7445 /* The vtable for a template class can be emitted in any translation
7446 unit in which the class is instantiated. When there is no key
7447 method, however, finish_struct_1 will already have added TYPE to
7448 the keyed_classes list. */
7449 if (TYPE_CONTAINS_VPTR_P (type) && CLASSTYPE_KEY_METHOD (type))
7450 keyed_classes = tree_cons (NULL_TREE, type, keyed_classes);
7456 tsubst_template_arg (tree t, tree args, tsubst_flags_t complain, tree in_decl)
7462 else if (TYPE_P (t))
7463 r = tsubst (t, args, complain, in_decl);
7466 r = tsubst_expr (t, args, complain, in_decl,
7467 /*integral_constant_expression_p=*/true);
7468 r = fold_non_dependent_expr (r);
7473 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
7474 NONTYPE_ARGUMENT_PACK. */
7477 make_fnparm_pack (tree spec_parm)
7479 /* Collect all of the extra "packed" parameters into an
7483 tree argpack = make_node (NONTYPE_ARGUMENT_PACK);
7484 tree argtypepack = make_node (TYPE_ARGUMENT_PACK);
7485 int i, len = list_length (spec_parm);
7487 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
7488 parmvec = make_tree_vec (len);
7489 parmtypevec = make_tree_vec (len);
7490 for (i = 0; i < len; i++, spec_parm = TREE_CHAIN (spec_parm))
7492 TREE_VEC_ELT (parmvec, i) = spec_parm;
7493 TREE_VEC_ELT (parmtypevec, i) = TREE_TYPE (spec_parm);
7496 /* Build the argument packs. */
7497 SET_ARGUMENT_PACK_ARGS (argpack, parmvec);
7498 SET_ARGUMENT_PACK_ARGS (argtypepack, parmtypevec);
7499 TREE_TYPE (argpack) = argtypepack;
7504 /* Substitute ARGS into T, which is an pack expansion
7505 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
7506 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
7507 (if only a partial substitution could be performed) or
7508 ERROR_MARK_NODE if there was an error. */
7510 tsubst_pack_expansion (tree t, tree args, tsubst_flags_t complain,
7514 tree pack, packs = NULL_TREE, unsubstituted_packs = NULL_TREE;
7515 tree first_arg_pack; int i, len = -1;
7518 bool very_local_specializations = false;
7520 gcc_assert (PACK_EXPANSION_P (t));
7521 pattern = PACK_EXPANSION_PATTERN (t);
7523 /* Determine the argument packs that will instantiate the parameter
7524 packs used in the expansion expression. While we're at it,
7525 compute the number of arguments to be expanded and make sure it
7527 for (pack = PACK_EXPANSION_PARAMETER_PACKS (t); pack;
7528 pack = TREE_CHAIN (pack))
7530 tree parm_pack = TREE_VALUE (pack);
7531 tree arg_pack = NULL_TREE;
7532 tree orig_arg = NULL_TREE;
7534 if (TREE_CODE (parm_pack) == PARM_DECL)
7536 arg_pack = retrieve_local_specialization (parm_pack);
7537 if (arg_pack == NULL_TREE)
7539 /* This can happen for a parameter name used later in a function
7540 declaration (such as in a late-specified return type). Just
7541 make a dummy decl, since it's only used for its type. */
7542 gcc_assert (cp_unevaluated_operand != 0);
7543 arg_pack = tsubst_decl (parm_pack, args, complain);
7544 arg_pack = make_fnparm_pack (arg_pack);
7549 int level, idx, levels;
7550 template_parm_level_and_index (parm_pack, &level, &idx);
7552 levels = TMPL_ARGS_DEPTH (args);
7553 if (level <= levels)
7554 arg_pack = TMPL_ARG (args, level, idx);
7557 orig_arg = arg_pack;
7558 if (arg_pack && TREE_CODE (arg_pack) == ARGUMENT_PACK_SELECT)
7559 arg_pack = ARGUMENT_PACK_SELECT_FROM_PACK (arg_pack);
7561 if (arg_pack && !ARGUMENT_PACK_P (arg_pack))
7562 /* This can only happen if we forget to expand an argument
7563 pack somewhere else. Just return an error, silently. */
7565 result = make_tree_vec (1);
7566 TREE_VEC_ELT (result, 0) = error_mark_node;
7571 && TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack)) == 1
7572 && PACK_EXPANSION_P (TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0)))
7574 tree expansion = TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0);
7575 tree pattern = PACK_EXPANSION_PATTERN (expansion);
7576 if ((TYPE_P (pattern) && same_type_p (pattern, parm_pack))
7577 || (!TYPE_P (pattern) && cp_tree_equal (parm_pack, pattern)))
7578 /* The argument pack that the parameter maps to is just an
7579 expansion of the parameter itself, such as one would
7580 find in the implicit typedef of a class inside the
7581 class itself. Consider this parameter "unsubstituted",
7582 so that we will maintain the outer pack expansion. */
7583 arg_pack = NULL_TREE;
7589 TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack));
7591 /* It's all-or-nothing with incomplete argument packs. */
7592 if (incomplete && !ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
7593 return error_mark_node;
7595 if (ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
7601 first_arg_pack = arg_pack;
7603 else if (len != my_len)
7605 if (TREE_CODE (t) == TYPE_PACK_EXPANSION)
7606 error ("mismatched argument pack lengths while expanding "
7610 error ("mismatched argument pack lengths while expanding "
7613 return error_mark_node;
7616 /* Keep track of the parameter packs and their corresponding
7618 packs = tree_cons (parm_pack, arg_pack, packs);
7619 TREE_TYPE (packs) = orig_arg;
7622 /* We can't substitute for this parameter pack. */
7623 unsubstituted_packs = tree_cons (TREE_PURPOSE (pack),
7625 unsubstituted_packs);
7628 /* We cannot expand this expansion expression, because we don't have
7629 all of the argument packs we need. Substitute into the pattern
7630 and return a PACK_EXPANSION_*. The caller will need to deal with
7632 if (unsubstituted_packs)
7635 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
7636 new_pat = tsubst_expr (pattern, args, complain, in_decl,
7637 /*integral_constant_expression_p=*/false);
7639 new_pat = tsubst (pattern, args, complain, in_decl);
7640 return make_pack_expansion (new_pat);
7643 /* We could not find any argument packs that work. */
7645 return error_mark_node;
7647 if (!local_specializations)
7649 /* We're in a late-specified return type, so we don't have a local
7650 specializations table. Create one for doing this expansion. */
7651 very_local_specializations = true;
7652 local_specializations = htab_create (37,
7653 hash_local_specialization,
7654 eq_local_specializations,
7658 /* For each argument in each argument pack, substitute into the
7660 result = make_tree_vec (len + incomplete);
7661 for (i = 0; i < len + incomplete; ++i)
7663 /* For parameter pack, change the substitution of the parameter
7664 pack to the ith argument in its argument pack, then expand
7666 for (pack = packs; pack; pack = TREE_CHAIN (pack))
7668 tree parm = TREE_PURPOSE (pack);
7670 if (TREE_CODE (parm) == PARM_DECL)
7672 /* Select the Ith argument from the pack. */
7673 tree arg = make_node (ARGUMENT_PACK_SELECT);
7674 ARGUMENT_PACK_SELECT_FROM_PACK (arg) = TREE_VALUE (pack);
7675 ARGUMENT_PACK_SELECT_INDEX (arg) = i;
7677 register_local_specialization (arg, parm);
7683 template_parm_level_and_index (parm, &level, &idx);
7687 /* Select the Ith argument from the pack. */
7688 value = make_node (ARGUMENT_PACK_SELECT);
7689 ARGUMENT_PACK_SELECT_FROM_PACK (value) = TREE_VALUE (pack);
7690 ARGUMENT_PACK_SELECT_INDEX (value) = i;
7693 /* Update the corresponding argument. */
7694 TMPL_ARG (args, level, idx) = value;
7698 /* Substitute into the PATTERN with the altered arguments. */
7699 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
7700 TREE_VEC_ELT (result, i) =
7701 tsubst_expr (pattern, args, complain, in_decl,
7702 /*integral_constant_expression_p=*/false);
7704 TREE_VEC_ELT (result, i) = tsubst (pattern, args, complain, in_decl);
7707 /* When we have incomplete argument packs, the last "expanded"
7708 result is itself a pack expansion, which allows us
7709 to deduce more arguments. */
7710 TREE_VEC_ELT (result, i) =
7711 make_pack_expansion (TREE_VEC_ELT (result, i));
7713 if (TREE_VEC_ELT (result, i) == error_mark_node)
7715 result = error_mark_node;
7720 /* Update ARGS to restore the substitution from parameter packs to
7721 their argument packs. */
7722 for (pack = packs; pack; pack = TREE_CHAIN (pack))
7724 tree parm = TREE_PURPOSE (pack);
7726 if (TREE_CODE (parm) == PARM_DECL)
7727 register_local_specialization (TREE_TYPE (pack), parm);
7731 template_parm_level_and_index (parm, &level, &idx);
7733 /* Update the corresponding argument. */
7734 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
7735 TREE_VEC_ELT (TREE_VEC_ELT (args, level -1 ), idx) =
7738 TREE_VEC_ELT (args, idx) = TREE_TYPE (pack);
7742 if (very_local_specializations)
7744 htab_delete (local_specializations);
7745 local_specializations = NULL;
7751 /* Substitute ARGS into the vector or list of template arguments T. */
7754 tsubst_template_args (tree t, tree args, tsubst_flags_t complain, tree in_decl)
7757 int len = TREE_VEC_LENGTH (t);
7758 int need_new = 0, i, expanded_len_adjust = 0, out;
7759 tree *elts = (tree *) alloca (len * sizeof (tree));
7761 for (i = 0; i < len; i++)
7763 tree orig_arg = TREE_VEC_ELT (t, i);
7766 if (TREE_CODE (orig_arg) == TREE_VEC)
7767 new_arg = tsubst_template_args (orig_arg, args, complain, in_decl);
7768 else if (PACK_EXPANSION_P (orig_arg))
7770 /* Substitute into an expansion expression. */
7771 new_arg = tsubst_pack_expansion (orig_arg, args, complain, in_decl);
7773 if (TREE_CODE (new_arg) == TREE_VEC)
7774 /* Add to the expanded length adjustment the number of
7775 expanded arguments. We subtract one from this
7776 measurement, because the argument pack expression
7777 itself is already counted as 1 in
7778 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
7779 the argument pack is empty. */
7780 expanded_len_adjust += TREE_VEC_LENGTH (new_arg) - 1;
7782 else if (ARGUMENT_PACK_P (orig_arg))
7784 /* Substitute into each of the arguments. */
7785 new_arg = make_node (TREE_CODE (orig_arg));
7787 SET_ARGUMENT_PACK_ARGS (
7789 tsubst_template_args (ARGUMENT_PACK_ARGS (orig_arg),
7790 args, complain, in_decl));
7792 if (ARGUMENT_PACK_ARGS (new_arg) == error_mark_node)
7793 new_arg = error_mark_node;
7795 if (TREE_CODE (new_arg) == NONTYPE_ARGUMENT_PACK) {
7796 TREE_TYPE (new_arg) = tsubst (TREE_TYPE (orig_arg), args,
7798 TREE_CONSTANT (new_arg) = TREE_CONSTANT (orig_arg);
7800 if (TREE_TYPE (new_arg) == error_mark_node)
7801 new_arg = error_mark_node;
7805 new_arg = tsubst_template_arg (orig_arg, args, complain, in_decl);
7807 if (new_arg == error_mark_node)
7808 return error_mark_node;
7811 if (new_arg != orig_arg)
7818 /* Make space for the expanded arguments coming from template
7820 t = make_tree_vec (len + expanded_len_adjust);
7821 for (i = 0, out = 0; i < len; i++)
7823 if ((PACK_EXPANSION_P (TREE_VEC_ELT (orig_t, i))
7824 || ARGUMENT_PACK_P (TREE_VEC_ELT (orig_t, i)))
7825 && TREE_CODE (elts[i]) == TREE_VEC)
7829 /* Now expand the template argument pack "in place". */
7830 for (idx = 0; idx < TREE_VEC_LENGTH (elts[i]); idx++, out++)
7831 TREE_VEC_ELT (t, out) = TREE_VEC_ELT (elts[i], idx);
7835 TREE_VEC_ELT (t, out) = elts[i];
7843 /* Return the result of substituting ARGS into the template parameters
7844 given by PARMS. If there are m levels of ARGS and m + n levels of
7845 PARMS, then the result will contain n levels of PARMS. For
7846 example, if PARMS is `template <class T> template <class U>
7847 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
7848 result will be `template <int*, double, class V>'. */
7851 tsubst_template_parms (tree parms, tree args, tsubst_flags_t complain)
7856 /* When substituting into a template, we must set
7857 PROCESSING_TEMPLATE_DECL as the template parameters may be
7858 dependent if they are based on one-another, and the dependency
7859 predicates are short-circuit outside of templates. */
7860 ++processing_template_decl;
7862 for (new_parms = &r;
7863 TMPL_PARMS_DEPTH (parms) > TMPL_ARGS_DEPTH (args);
7864 new_parms = &(TREE_CHAIN (*new_parms)),
7865 parms = TREE_CHAIN (parms))
7868 make_tree_vec (TREE_VEC_LENGTH (TREE_VALUE (parms)));
7871 for (i = 0; i < TREE_VEC_LENGTH (new_vec); ++i)
7877 if (parms == error_mark_node)
7880 tuple = TREE_VEC_ELT (TREE_VALUE (parms), i);
7882 if (tuple == error_mark_node)
7885 default_value = TREE_PURPOSE (tuple);
7886 parm_decl = TREE_VALUE (tuple);
7888 parm_decl = tsubst (parm_decl, args, complain, NULL_TREE);
7889 if (TREE_CODE (parm_decl) == PARM_DECL
7890 && invalid_nontype_parm_type_p (TREE_TYPE (parm_decl), complain))
7891 parm_decl = error_mark_node;
7892 default_value = tsubst_template_arg (default_value, args,
7893 complain, NULL_TREE);
7895 tuple = build_tree_list (default_value, parm_decl);
7896 TREE_VEC_ELT (new_vec, i) = tuple;
7900 tree_cons (size_int (TMPL_PARMS_DEPTH (parms)
7901 - TMPL_ARGS_DEPTH (args)),
7902 new_vec, NULL_TREE);
7905 --processing_template_decl;
7910 /* Substitute the ARGS into the indicated aggregate (or enumeration)
7911 type T. If T is not an aggregate or enumeration type, it is
7912 handled as if by tsubst. IN_DECL is as for tsubst. If
7913 ENTERING_SCOPE is nonzero, T is the context for a template which
7914 we are presently tsubst'ing. Return the substituted value. */
7917 tsubst_aggr_type (tree t,
7919 tsubst_flags_t complain,
7926 switch (TREE_CODE (t))
7929 if (TYPE_PTRMEMFUNC_P (t))
7930 return tsubst (TYPE_PTRMEMFUNC_FN_TYPE (t), args, complain, in_decl);
7932 /* Else fall through. */
7935 if (TYPE_TEMPLATE_INFO (t) && uses_template_parms (t))
7940 int saved_unevaluated_operand;
7941 int saved_inhibit_evaluation_warnings;
7943 /* In "sizeof(X<I>)" we need to evaluate "I". */
7944 saved_unevaluated_operand = cp_unevaluated_operand;
7945 cp_unevaluated_operand = 0;
7946 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
7947 c_inhibit_evaluation_warnings = 0;
7949 /* First, determine the context for the type we are looking
7951 context = TYPE_CONTEXT (t);
7954 context = tsubst_aggr_type (context, args, complain,
7955 in_decl, /*entering_scope=*/1);
7956 /* If context is a nested class inside a class template,
7957 it may still need to be instantiated (c++/33959). */
7958 if (TYPE_P (context))
7959 context = complete_type (context);
7962 /* Then, figure out what arguments are appropriate for the
7963 type we are trying to find. For example, given:
7965 template <class T> struct S;
7966 template <class T, class U> void f(T, U) { S<U> su; }
7968 and supposing that we are instantiating f<int, double>,
7969 then our ARGS will be {int, double}, but, when looking up
7970 S we only want {double}. */
7971 argvec = tsubst_template_args (TYPE_TI_ARGS (t), args,
7973 if (argvec == error_mark_node)
7974 r = error_mark_node;
7977 r = lookup_template_class (t, argvec, in_decl, context,
7978 entering_scope, complain);
7979 r = cp_build_qualified_type_real (r, TYPE_QUALS (t), complain);
7982 cp_unevaluated_operand = saved_unevaluated_operand;
7983 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
7988 /* This is not a template type, so there's nothing to do. */
7992 return tsubst (t, args, complain, in_decl);
7996 /* Substitute into the default argument ARG (a default argument for
7997 FN), which has the indicated TYPE. */
8000 tsubst_default_argument (tree fn, tree type, tree arg)
8002 tree saved_class_ptr = NULL_TREE;
8003 tree saved_class_ref = NULL_TREE;
8005 /* This default argument came from a template. Instantiate the
8006 default argument here, not in tsubst. In the case of
8015 we must be careful to do name lookup in the scope of S<T>,
8016 rather than in the current class. */
8017 push_access_scope (fn);
8018 /* The "this" pointer is not valid in a default argument. */
8021 saved_class_ptr = current_class_ptr;
8022 cp_function_chain->x_current_class_ptr = NULL_TREE;
8023 saved_class_ref = current_class_ref;
8024 cp_function_chain->x_current_class_ref = NULL_TREE;
8027 push_deferring_access_checks(dk_no_deferred);
8028 /* The default argument expression may cause implicitly defined
8029 member functions to be synthesized, which will result in garbage
8030 collection. We must treat this situation as if we were within
8031 the body of function so as to avoid collecting live data on the
8034 arg = tsubst_expr (arg, DECL_TI_ARGS (fn),
8035 tf_warning_or_error, NULL_TREE,
8036 /*integral_constant_expression_p=*/false);
8038 pop_deferring_access_checks();
8040 /* Restore the "this" pointer. */
8043 cp_function_chain->x_current_class_ptr = saved_class_ptr;
8044 cp_function_chain->x_current_class_ref = saved_class_ref;
8047 pop_access_scope (fn);
8049 /* Make sure the default argument is reasonable. */
8050 arg = check_default_argument (type, arg);
8055 /* Substitute into all the default arguments for FN. */
8058 tsubst_default_arguments (tree fn)
8063 tmpl_args = DECL_TI_ARGS (fn);
8065 /* If this function is not yet instantiated, we certainly don't need
8066 its default arguments. */
8067 if (uses_template_parms (tmpl_args))
8070 for (arg = TYPE_ARG_TYPES (TREE_TYPE (fn));
8072 arg = TREE_CHAIN (arg))
8073 if (TREE_PURPOSE (arg))
8074 TREE_PURPOSE (arg) = tsubst_default_argument (fn,
8076 TREE_PURPOSE (arg));
8079 /* Substitute the ARGS into the T, which is a _DECL. Return the
8080 result of the substitution. Issue error and warning messages under
8081 control of COMPLAIN. */
8084 tsubst_decl (tree t, tree args, tsubst_flags_t complain)
8086 location_t saved_loc;
8090 /* Set the filename and linenumber to improve error-reporting. */
8091 saved_loc = input_location;
8092 input_location = DECL_SOURCE_LOCATION (t);
8094 switch (TREE_CODE (t))
8098 /* We can get here when processing a member function template,
8099 member class template, and template template parameter of
8100 a template class. */
8101 tree decl = DECL_TEMPLATE_RESULT (t);
8106 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
8108 /* Template template parameter is treated here. */
8109 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8110 if (new_type == error_mark_node)
8111 return error_mark_node;
8114 TREE_CHAIN (r) = NULL_TREE;
8115 TREE_TYPE (r) = new_type;
8116 DECL_TEMPLATE_RESULT (r)
8117 = build_decl (DECL_SOURCE_LOCATION (decl),
8118 TYPE_DECL, DECL_NAME (decl), new_type);
8119 DECL_TEMPLATE_PARMS (r)
8120 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
8122 TYPE_NAME (new_type) = r;
8126 /* We might already have an instance of this template.
8127 The ARGS are for the surrounding class type, so the
8128 full args contain the tsubst'd args for the context,
8129 plus the innermost args from the template decl. */
8130 tmpl_args = DECL_CLASS_TEMPLATE_P (t)
8131 ? CLASSTYPE_TI_ARGS (TREE_TYPE (t))
8132 : DECL_TI_ARGS (DECL_TEMPLATE_RESULT (t));
8133 /* Because this is a template, the arguments will still be
8134 dependent, even after substitution. If
8135 PROCESSING_TEMPLATE_DECL is not set, the dependency
8136 predicates will short-circuit. */
8137 ++processing_template_decl;
8138 full_args = tsubst_template_args (tmpl_args, args,
8140 --processing_template_decl;
8141 if (full_args == error_mark_node)
8142 return error_mark_node;
8144 /* tsubst_template_args doesn't copy the vector if
8145 nothing changed. But, *something* should have
8147 gcc_assert (full_args != tmpl_args);
8149 spec = retrieve_specialization (t, full_args,
8150 /*class_specializations_p=*/true);
8151 if (spec != NULL_TREE)
8157 /* Make a new template decl. It will be similar to the
8158 original, but will record the current template arguments.
8159 We also create a new function declaration, which is just
8160 like the old one, but points to this new template, rather
8161 than the old one. */
8163 gcc_assert (DECL_LANG_SPECIFIC (r) != 0);
8164 TREE_CHAIN (r) = NULL_TREE;
8166 DECL_TEMPLATE_INFO (r) = build_tree_list (t, args);
8168 if (TREE_CODE (decl) == TYPE_DECL)
8171 ++processing_template_decl;
8172 new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8173 --processing_template_decl;
8174 if (new_type == error_mark_node)
8175 return error_mark_node;
8177 TREE_TYPE (r) = new_type;
8178 CLASSTYPE_TI_TEMPLATE (new_type) = r;
8179 DECL_TEMPLATE_RESULT (r) = TYPE_MAIN_DECL (new_type);
8180 DECL_TI_ARGS (r) = CLASSTYPE_TI_ARGS (new_type);
8181 DECL_CONTEXT (r) = TYPE_CONTEXT (new_type);
8186 ++processing_template_decl;
8187 new_decl = tsubst (decl, args, complain, in_decl);
8188 --processing_template_decl;
8189 if (new_decl == error_mark_node)
8190 return error_mark_node;
8192 DECL_TEMPLATE_RESULT (r) = new_decl;
8193 DECL_TI_TEMPLATE (new_decl) = r;
8194 TREE_TYPE (r) = TREE_TYPE (new_decl);
8195 DECL_TI_ARGS (r) = DECL_TI_ARGS (new_decl);
8196 DECL_CONTEXT (r) = DECL_CONTEXT (new_decl);
8199 SET_DECL_IMPLICIT_INSTANTIATION (r);
8200 DECL_TEMPLATE_INSTANTIATIONS (r) = NULL_TREE;
8201 DECL_TEMPLATE_SPECIALIZATIONS (r) = NULL_TREE;
8203 /* The template parameters for this new template are all the
8204 template parameters for the old template, except the
8205 outermost level of parameters. */
8206 DECL_TEMPLATE_PARMS (r)
8207 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
8210 if (PRIMARY_TEMPLATE_P (t))
8211 DECL_PRIMARY_TEMPLATE (r) = r;
8213 if (TREE_CODE (decl) != TYPE_DECL)
8214 /* Record this non-type partial instantiation. */
8215 register_specialization (r, t,
8216 DECL_TI_ARGS (DECL_TEMPLATE_RESULT (r)),
8224 tree argvec = NULL_TREE;
8232 /* Nobody should be tsubst'ing into non-template functions. */
8233 gcc_assert (DECL_TEMPLATE_INFO (t) != NULL_TREE);
8235 if (TREE_CODE (DECL_TI_TEMPLATE (t)) == TEMPLATE_DECL)
8240 /* If T is not dependent, just return it. We have to
8241 increment PROCESSING_TEMPLATE_DECL because
8242 value_dependent_expression_p assumes that nothing is
8243 dependent when PROCESSING_TEMPLATE_DECL is zero. */
8244 ++processing_template_decl;
8245 dependent_p = value_dependent_expression_p (t);
8246 --processing_template_decl;
8250 /* Calculate the most general template of which R is a
8251 specialization, and the complete set of arguments used to
8253 gen_tmpl = most_general_template (DECL_TI_TEMPLATE (t));
8254 argvec = tsubst_template_args (DECL_TI_ARGS
8255 (DECL_TEMPLATE_RESULT (gen_tmpl)),
8256 args, complain, in_decl);
8258 /* Check to see if we already have this specialization. */
8259 spec = retrieve_specialization (gen_tmpl, argvec,
8260 /*class_specializations_p=*/false);
8268 /* We can see more levels of arguments than parameters if
8269 there was a specialization of a member template, like
8272 template <class T> struct S { template <class U> void f(); }
8273 template <> template <class U> void S<int>::f(U);
8275 Here, we'll be substituting into the specialization,
8276 because that's where we can find the code we actually
8277 want to generate, but we'll have enough arguments for
8278 the most general template.
8280 We also deal with the peculiar case:
8282 template <class T> struct S {
8283 template <class U> friend void f();
8285 template <class U> void f() {}
8287 template void f<double>();
8289 Here, the ARGS for the instantiation of will be {int,
8290 double}. But, we only need as many ARGS as there are
8291 levels of template parameters in CODE_PATTERN. We are
8292 careful not to get fooled into reducing the ARGS in
8295 template <class T> struct S { template <class U> void f(U); }
8296 template <class T> template <> void S<T>::f(int) {}
8298 which we can spot because the pattern will be a
8299 specialization in this case. */
8300 args_depth = TMPL_ARGS_DEPTH (args);
8302 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (t)));
8303 if (args_depth > parms_depth
8304 && !DECL_TEMPLATE_SPECIALIZATION (t))
8305 args = get_innermost_template_args (args, parms_depth);
8309 /* This special case arises when we have something like this:
8311 template <class T> struct S {
8312 friend void f<int>(int, double);
8315 Here, the DECL_TI_TEMPLATE for the friend declaration
8316 will be an IDENTIFIER_NODE. We are being called from
8317 tsubst_friend_function, and we want only to create a
8318 new decl (R) with appropriate types so that we can call
8319 determine_specialization. */
8320 gen_tmpl = NULL_TREE;
8323 if (DECL_CLASS_SCOPE_P (t))
8325 if (DECL_NAME (t) == constructor_name (DECL_CONTEXT (t)))
8329 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args,
8330 complain, t, /*entering_scope=*/1);
8335 ctx = DECL_CONTEXT (t);
8337 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8338 if (type == error_mark_node)
8339 return error_mark_node;
8341 /* We do NOT check for matching decls pushed separately at this
8342 point, as they may not represent instantiations of this
8343 template, and in any case are considered separate under the
8346 DECL_USE_TEMPLATE (r) = 0;
8347 TREE_TYPE (r) = type;
8348 /* Clear out the mangled name and RTL for the instantiation. */
8349 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
8350 SET_DECL_RTL (r, NULL_RTX);
8351 /* Leave DECL_INITIAL set on deleted instantiations. */
8352 if (!DECL_DELETED_FN (r))
8353 DECL_INITIAL (r) = NULL_TREE;
8354 DECL_CONTEXT (r) = ctx;
8356 if (member && DECL_CONV_FN_P (r))
8357 /* Type-conversion operator. Reconstruct the name, in
8358 case it's the name of one of the template's parameters. */
8359 DECL_NAME (r) = mangle_conv_op_name_for_type (TREE_TYPE (type));
8361 DECL_ARGUMENTS (r) = tsubst (DECL_ARGUMENTS (t), args,
8363 DECL_RESULT (r) = NULL_TREE;
8365 TREE_STATIC (r) = 0;
8366 TREE_PUBLIC (r) = TREE_PUBLIC (t);
8367 DECL_EXTERNAL (r) = 1;
8368 /* If this is an instantiation of a function with internal
8369 linkage, we already know what object file linkage will be
8370 assigned to the instantiation. */
8371 DECL_INTERFACE_KNOWN (r) = !TREE_PUBLIC (r);
8372 DECL_DEFER_OUTPUT (r) = 0;
8373 TREE_CHAIN (r) = NULL_TREE;
8374 DECL_PENDING_INLINE_INFO (r) = 0;
8375 DECL_PENDING_INLINE_P (r) = 0;
8376 DECL_SAVED_TREE (r) = NULL_TREE;
8377 DECL_STRUCT_FUNCTION (r) = NULL;
8379 if (DECL_CLONED_FUNCTION (r))
8381 DECL_CLONED_FUNCTION (r) = tsubst (DECL_CLONED_FUNCTION (t),
8383 TREE_CHAIN (r) = TREE_CHAIN (DECL_CLONED_FUNCTION (r));
8384 TREE_CHAIN (DECL_CLONED_FUNCTION (r)) = r;
8387 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
8388 this in the special friend case mentioned above where
8389 GEN_TMPL is NULL. */
8392 DECL_TEMPLATE_INFO (r)
8393 = tree_cons (gen_tmpl, argvec, NULL_TREE);
8394 SET_DECL_IMPLICIT_INSTANTIATION (r);
8395 register_specialization (r, gen_tmpl, argvec, false);
8397 /* We're not supposed to instantiate default arguments
8398 until they are called, for a template. But, for a
8401 template <class T> void f ()
8402 { extern void g(int i = T()); }
8404 we should do the substitution when the template is
8405 instantiated. We handle the member function case in
8406 instantiate_class_template since the default arguments
8407 might refer to other members of the class. */
8409 && !PRIMARY_TEMPLATE_P (gen_tmpl)
8410 && !uses_template_parms (argvec))
8411 tsubst_default_arguments (r);
8414 DECL_TEMPLATE_INFO (r) = NULL_TREE;
8416 /* Copy the list of befriending classes. */
8417 for (friends = &DECL_BEFRIENDING_CLASSES (r);
8419 friends = &TREE_CHAIN (*friends))
8421 *friends = copy_node (*friends);
8422 TREE_VALUE (*friends) = tsubst (TREE_VALUE (*friends),
8427 if (DECL_CONSTRUCTOR_P (r) || DECL_DESTRUCTOR_P (r))
8429 maybe_retrofit_in_chrg (r);
8430 if (DECL_CONSTRUCTOR_P (r))
8431 grok_ctor_properties (ctx, r);
8432 /* If this is an instantiation of a member template, clone it.
8433 If it isn't, that'll be handled by
8434 clone_constructors_and_destructors. */
8435 if (PRIMARY_TEMPLATE_P (gen_tmpl))
8436 clone_function_decl (r, /*update_method_vec_p=*/0);
8438 else if (IDENTIFIER_OPNAME_P (DECL_NAME (r))
8439 && !grok_op_properties (r, (complain & tf_error) != 0))
8440 return error_mark_node;
8442 if (DECL_FRIEND_P (t) && DECL_FRIEND_CONTEXT (t))
8443 SET_DECL_FRIEND_CONTEXT (r,
8444 tsubst (DECL_FRIEND_CONTEXT (t),
8445 args, complain, in_decl));
8447 /* Possibly limit visibility based on template args. */
8448 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
8449 if (DECL_VISIBILITY_SPECIFIED (t))
8451 DECL_VISIBILITY_SPECIFIED (r) = 0;
8453 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
8455 determine_visibility (r);
8457 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
8458 args, complain, in_decl);
8464 tree type = NULL_TREE;
8466 tree expanded_types = NULL_TREE;
8467 tree prev_r = NULL_TREE;
8468 tree first_r = NULL_TREE;
8470 if (FUNCTION_PARAMETER_PACK_P (t))
8472 /* If there is a local specialization that isn't a
8473 parameter pack, it means that we're doing a "simple"
8474 substitution from inside tsubst_pack_expansion. Just
8475 return the local specialization (which will be a single
8477 tree spec = retrieve_local_specialization (t);
8479 && TREE_CODE (spec) == PARM_DECL
8480 && TREE_CODE (TREE_TYPE (spec)) != TYPE_PACK_EXPANSION)
8483 /* Expand the TYPE_PACK_EXPANSION that provides the types for
8484 the parameters in this function parameter pack. */
8485 expanded_types = tsubst_pack_expansion (TREE_TYPE (t), args,
8487 if (TREE_CODE (expanded_types) == TREE_VEC)
8489 len = TREE_VEC_LENGTH (expanded_types);
8491 /* Zero-length parameter packs are boring. Just substitute
8494 return tsubst (TREE_CHAIN (t), args, complain,
8499 /* All we did was update the type. Make a note of that. */
8500 type = expanded_types;
8501 expanded_types = NULL_TREE;
8505 /* Loop through all of the parameter's we'll build. When T is
8506 a function parameter pack, LEN is the number of expanded
8507 types in EXPANDED_TYPES; otherwise, LEN is 1. */
8509 for (i = 0; i < len; ++i)
8513 if (DECL_TEMPLATE_PARM_P (t))
8514 SET_DECL_TEMPLATE_PARM_P (r);
8517 /* We're on the Ith parameter of the function parameter
8520 /* Get the Ith type. */
8521 type = TREE_VEC_ELT (expanded_types, i);
8524 /* Rename the parameter to include the index. */
8526 make_ith_pack_parameter_name (DECL_NAME (r), i);
8529 /* We're dealing with a normal parameter. */
8530 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8532 type = type_decays_to (type);
8533 TREE_TYPE (r) = type;
8534 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
8536 if (DECL_INITIAL (r))
8538 if (TREE_CODE (DECL_INITIAL (r)) != TEMPLATE_PARM_INDEX)
8539 DECL_INITIAL (r) = TREE_TYPE (r);
8541 DECL_INITIAL (r) = tsubst (DECL_INITIAL (r), args,
8545 DECL_CONTEXT (r) = NULL_TREE;
8547 if (!DECL_TEMPLATE_PARM_P (r))
8548 DECL_ARG_TYPE (r) = type_passed_as (type);
8550 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
8551 args, complain, in_decl);
8553 /* Keep track of the first new parameter we
8554 generate. That's what will be returned to the
8559 /* Build a proper chain of parameters when substituting
8560 into a function parameter pack. */
8562 TREE_CHAIN (prev_r) = r;
8566 TREE_CHAIN (r) = tsubst (TREE_CHAIN (t), args,
8567 complain, TREE_CHAIN (t));
8569 /* FIRST_R contains the start of the chain we've built. */
8579 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8580 if (type == error_mark_node)
8581 return error_mark_node;
8582 TREE_TYPE (r) = type;
8583 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
8585 /* DECL_INITIAL gives the number of bits in a bit-field. */
8587 = tsubst_expr (DECL_INITIAL (t), args,
8589 /*integral_constant_expression_p=*/true);
8590 /* We don't have to set DECL_CONTEXT here; it is set by
8591 finish_member_declaration. */
8592 TREE_CHAIN (r) = NULL_TREE;
8593 if (VOID_TYPE_P (type))
8594 error ("instantiation of %q+D as type %qT", r, type);
8596 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
8597 args, complain, in_decl);
8602 /* We reach here only for member using decls. */
8603 if (DECL_DEPENDENT_P (t))
8605 r = do_class_using_decl
8606 (tsubst_copy (USING_DECL_SCOPE (t), args, complain, in_decl),
8607 tsubst_copy (DECL_NAME (t), args, complain, in_decl));
8609 r = error_mark_node;
8612 TREE_PROTECTED (r) = TREE_PROTECTED (t);
8613 TREE_PRIVATE (r) = TREE_PRIVATE (t);
8619 TREE_CHAIN (r) = NULL_TREE;
8626 tree argvec = NULL_TREE;
8627 tree gen_tmpl = NULL_TREE;
8629 tree tmpl = NULL_TREE;
8631 tree type = NULL_TREE;
8634 if (TREE_CODE (t) == TYPE_DECL
8635 && t == TYPE_MAIN_DECL (TREE_TYPE (t)))
8637 /* If this is the canonical decl, we don't have to
8638 mess with instantiations, and often we can't (for
8639 typename, template type parms and such). Note that
8640 TYPE_NAME is not correct for the above test if
8641 we've copied the type for a typedef. */
8642 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8643 if (type == error_mark_node)
8644 return error_mark_node;
8645 r = TYPE_NAME (type);
8649 /* Check to see if we already have the specialization we
8652 if (DECL_CLASS_SCOPE_P (t) || DECL_NAMESPACE_SCOPE_P (t))
8654 /* T is a static data member or namespace-scope entity.
8655 We have to substitute into namespace-scope variables
8656 (even though such entities are never templates) because
8659 template <class T> void f() { extern T t; }
8661 where the entity referenced is not known until
8662 instantiation time. */
8664 ctx = DECL_CONTEXT (t);
8665 if (DECL_CLASS_SCOPE_P (t))
8667 ctx = tsubst_aggr_type (ctx, args,
8669 in_decl, /*entering_scope=*/1);
8670 /* If CTX is unchanged, then T is in fact the
8671 specialization we want. That situation occurs when
8672 referencing a static data member within in its own
8673 class. We can use pointer equality, rather than
8674 same_type_p, because DECL_CONTEXT is always
8676 if (ctx == DECL_CONTEXT (t))
8682 tmpl = DECL_TI_TEMPLATE (t);
8683 gen_tmpl = most_general_template (tmpl);
8684 argvec = tsubst (DECL_TI_ARGS (t), args, complain, in_decl);
8685 spec = (retrieve_specialization
8687 /*class_specializations_p=*/false));
8692 /* A local variable. */
8694 /* Subsequent calls to pushdecl will fill this in. */
8696 spec = retrieve_local_specialization (t);
8698 /* If we already have the specialization we need, there is
8699 nothing more to do. */
8706 /* Create a new node for the specialization we need. */
8708 if (type == NULL_TREE)
8709 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8710 if (TREE_CODE (r) == VAR_DECL)
8712 /* Even if the original location is out of scope, the
8713 newly substituted one is not. */
8714 DECL_DEAD_FOR_LOCAL (r) = 0;
8715 DECL_INITIALIZED_P (r) = 0;
8716 DECL_TEMPLATE_INSTANTIATED (r) = 0;
8717 if (type == error_mark_node)
8718 return error_mark_node;
8719 if (TREE_CODE (type) == FUNCTION_TYPE)
8721 /* It may seem that this case cannot occur, since:
8726 declares a function, not a variable. However:
8729 template <typename T> void g() { T t; }
8730 template void g<f>();
8732 is an attempt to declare a variable with function
8734 error ("variable %qD has function type",
8735 /* R is not yet sufficiently initialized, so we
8736 just use its name. */
8738 return error_mark_node;
8740 type = complete_type (type);
8741 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r)
8742 = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (t);
8743 type = check_var_type (DECL_NAME (r), type);
8745 if (DECL_HAS_VALUE_EXPR_P (t))
8747 tree ve = DECL_VALUE_EXPR (t);
8748 ve = tsubst_expr (ve, args, complain, in_decl,
8749 /*constant_expression_p=*/false);
8750 SET_DECL_VALUE_EXPR (r, ve);
8753 else if (DECL_SELF_REFERENCE_P (t))
8754 SET_DECL_SELF_REFERENCE_P (r);
8755 TREE_TYPE (r) = type;
8756 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
8757 DECL_CONTEXT (r) = ctx;
8758 /* Clear out the mangled name and RTL for the instantiation. */
8759 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
8760 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
8761 SET_DECL_RTL (r, NULL_RTX);
8762 /* The initializer must not be expanded until it is required;
8764 DECL_INITIAL (r) = NULL_TREE;
8765 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
8766 SET_DECL_RTL (r, NULL_RTX);
8767 DECL_SIZE (r) = DECL_SIZE_UNIT (r) = 0;
8768 if (TREE_CODE (r) == VAR_DECL)
8770 /* Possibly limit visibility based on template args. */
8771 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
8772 if (DECL_VISIBILITY_SPECIFIED (t))
8774 DECL_VISIBILITY_SPECIFIED (r) = 0;
8776 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
8778 determine_visibility (r);
8780 /* Preserve a typedef that names a type. */
8781 else if (TREE_CODE (r) == TYPE_DECL
8782 && DECL_ORIGINAL_TYPE (t)
8783 && type != error_mark_node)
8785 DECL_ORIGINAL_TYPE (r) = tsubst (DECL_ORIGINAL_TYPE (t),
8786 args, complain, in_decl);
8787 TREE_TYPE (r) = type = build_variant_type_copy (type);
8788 TYPE_NAME (type) = r;
8793 /* A static data member declaration is always marked
8794 external when it is declared in-class, even if an
8795 initializer is present. We mimic the non-template
8797 DECL_EXTERNAL (r) = 1;
8799 register_specialization (r, gen_tmpl, argvec, false);
8800 DECL_TEMPLATE_INFO (r) = tree_cons (tmpl, argvec, NULL_TREE);
8801 SET_DECL_IMPLICIT_INSTANTIATION (r);
8804 register_local_specialization (r, t);
8806 TREE_CHAIN (r) = NULL_TREE;
8808 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r),
8809 (int) ATTR_FLAG_TYPE_IN_PLACE,
8810 args, complain, in_decl);
8819 /* Restore the file and line information. */
8820 input_location = saved_loc;
8825 /* Substitute into the ARG_TYPES of a function type. */
8828 tsubst_arg_types (tree arg_types,
8830 tsubst_flags_t complain,
8833 tree remaining_arg_types;
8834 tree type = NULL_TREE;
8836 tree expanded_args = NULL_TREE;
8839 if (!arg_types || arg_types == void_list_node)
8842 remaining_arg_types = tsubst_arg_types (TREE_CHAIN (arg_types),
8843 args, complain, in_decl);
8844 if (remaining_arg_types == error_mark_node)
8845 return error_mark_node;
8847 if (PACK_EXPANSION_P (TREE_VALUE (arg_types)))
8849 /* For a pack expansion, perform substitution on the
8850 entire expression. Later on, we'll handle the arguments
8852 expanded_args = tsubst_pack_expansion (TREE_VALUE (arg_types),
8853 args, complain, in_decl);
8855 if (TREE_CODE (expanded_args) == TREE_VEC)
8856 /* So that we'll spin through the parameters, one by one. */
8857 i = TREE_VEC_LENGTH (expanded_args);
8860 /* We only partially substituted into the parameter
8861 pack. Our type is TYPE_PACK_EXPANSION. */
8862 type = expanded_args;
8863 expanded_args = NULL_TREE;
8871 type = TREE_VEC_ELT (expanded_args, i);
8873 type = tsubst (TREE_VALUE (arg_types), args, complain, in_decl);
8875 if (type == error_mark_node)
8876 return error_mark_node;
8877 if (VOID_TYPE_P (type))
8879 if (complain & tf_error)
8881 error ("invalid parameter type %qT", type);
8883 error ("in declaration %q+D", in_decl);
8885 return error_mark_node;
8888 /* Do array-to-pointer, function-to-pointer conversion, and ignore
8889 top-level qualifiers as required. */
8890 type = TYPE_MAIN_VARIANT (type_decays_to (type));
8892 /* We do not substitute into default arguments here. The standard
8893 mandates that they be instantiated only when needed, which is
8894 done in build_over_call. */
8895 default_arg = TREE_PURPOSE (arg_types);
8897 if (default_arg && TREE_CODE (default_arg) == DEFAULT_ARG)
8899 /* We've instantiated a template before its default arguments
8900 have been parsed. This can happen for a nested template
8901 class, and is not an error unless we require the default
8902 argument in a call of this function. */
8903 remaining_arg_types =
8904 tree_cons (default_arg, type, remaining_arg_types);
8905 VEC_safe_push (tree, gc, DEFARG_INSTANTIATIONS (default_arg),
8906 remaining_arg_types);
8909 remaining_arg_types =
8910 hash_tree_cons (default_arg, type, remaining_arg_types);
8913 return remaining_arg_types;
8916 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
8917 *not* handle the exception-specification for FNTYPE, because the
8918 initial substitution of explicitly provided template parameters
8919 during argument deduction forbids substitution into the
8920 exception-specification:
8924 All references in the function type of the function template to the
8925 corresponding template parameters are replaced by the specified tem-
8926 plate argument values. If a substitution in a template parameter or
8927 in the function type of the function template results in an invalid
8928 type, type deduction fails. [Note: The equivalent substitution in
8929 exception specifications is done only when the function is instanti-
8930 ated, at which point a program is ill-formed if the substitution
8931 results in an invalid type.] */
8934 tsubst_function_type (tree t,
8936 tsubst_flags_t complain,
8943 /* The TYPE_CONTEXT is not used for function/method types. */
8944 gcc_assert (TYPE_CONTEXT (t) == NULL_TREE);
8946 /* Substitute the return type. */
8947 return_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8948 if (return_type == error_mark_node)
8949 return error_mark_node;
8950 /* The standard does not presently indicate that creation of a
8951 function type with an invalid return type is a deduction failure.
8952 However, that is clearly analogous to creating an array of "void"
8953 or a reference to a reference. This is core issue #486. */
8954 if (TREE_CODE (return_type) == ARRAY_TYPE
8955 || TREE_CODE (return_type) == FUNCTION_TYPE)
8957 if (complain & tf_error)
8959 if (TREE_CODE (return_type) == ARRAY_TYPE)
8960 error ("function returning an array");
8962 error ("function returning a function");
8964 return error_mark_node;
8967 /* Substitute the argument types. */
8968 arg_types = tsubst_arg_types (TYPE_ARG_TYPES (t), args,
8970 if (arg_types == error_mark_node)
8971 return error_mark_node;
8973 /* Construct a new type node and return it. */
8974 if (TREE_CODE (t) == FUNCTION_TYPE)
8975 fntype = build_function_type (return_type, arg_types);
8978 tree r = TREE_TYPE (TREE_VALUE (arg_types));
8979 if (! MAYBE_CLASS_TYPE_P (r))
8983 Type deduction may fail for any of the following
8986 -- Attempting to create "pointer to member of T" when T
8987 is not a class type. */
8988 if (complain & tf_error)
8989 error ("creating pointer to member function of non-class type %qT",
8991 return error_mark_node;
8994 fntype = build_method_type_directly (r, return_type,
8995 TREE_CHAIN (arg_types));
8997 fntype = cp_build_qualified_type_real (fntype, TYPE_QUALS (t), complain);
8998 fntype = cp_build_type_attribute_variant (fntype, TYPE_ATTRIBUTES (t));
9003 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
9004 ARGS into that specification, and return the substituted
9005 specification. If there is no specification, return NULL_TREE. */
9008 tsubst_exception_specification (tree fntype,
9010 tsubst_flags_t complain,
9016 specs = TYPE_RAISES_EXCEPTIONS (fntype);
9017 new_specs = NULL_TREE;
9020 if (! TREE_VALUE (specs))
9027 tree expanded_specs = NULL_TREE;
9029 if (PACK_EXPANSION_P (TREE_VALUE (specs)))
9031 /* Expand the pack expansion type. */
9032 expanded_specs = tsubst_pack_expansion (TREE_VALUE (specs),
9036 if (expanded_specs == error_mark_node)
9037 return error_mark_node;
9038 else if (TREE_CODE (expanded_specs) == TREE_VEC)
9039 len = TREE_VEC_LENGTH (expanded_specs);
9042 /* We're substituting into a member template, so
9043 we got a TYPE_PACK_EXPANSION back. Add that
9044 expansion and move on. */
9045 gcc_assert (TREE_CODE (expanded_specs)
9046 == TYPE_PACK_EXPANSION);
9047 new_specs = add_exception_specifier (new_specs,
9050 specs = TREE_CHAIN (specs);
9055 for (i = 0; i < len; ++i)
9058 spec = TREE_VEC_ELT (expanded_specs, i);
9060 spec = tsubst (TREE_VALUE (specs), args, complain, in_decl);
9061 if (spec == error_mark_node)
9063 new_specs = add_exception_specifier (new_specs, spec,
9067 specs = TREE_CHAIN (specs);
9073 /* Take the tree structure T and replace template parameters used
9074 therein with the argument vector ARGS. IN_DECL is an associated
9075 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
9076 Issue error and warning messages under control of COMPLAIN. Note
9077 that we must be relatively non-tolerant of extensions here, in
9078 order to preserve conformance; if we allow substitutions that
9079 should not be allowed, we may allow argument deductions that should
9080 not succeed, and therefore report ambiguous overload situations
9081 where there are none. In theory, we could allow the substitution,
9082 but indicate that it should have failed, and allow our caller to
9083 make sure that the right thing happens, but we don't try to do this
9086 This function is used for dealing with types, decls and the like;
9087 for expressions, use tsubst_expr or tsubst_copy. */
9090 tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl)
9094 if (t == NULL_TREE || t == error_mark_node
9095 || t == integer_type_node
9096 || t == void_type_node
9097 || t == char_type_node
9098 || t == unknown_type_node
9099 || TREE_CODE (t) == NAMESPACE_DECL)
9103 return tsubst_decl (t, args, complain);
9105 if (args == NULL_TREE)
9108 if (TREE_CODE (t) == IDENTIFIER_NODE)
9109 type = IDENTIFIER_TYPE_VALUE (t);
9111 type = TREE_TYPE (t);
9113 gcc_assert (type != unknown_type_node);
9115 /* Reuse typedefs. We need to do this to handle dependent attributes,
9116 such as attribute aligned. */
9119 && TYPE_NAME (t) != TYPE_MAIN_DECL (t))
9121 tree decl = TYPE_NAME (t);
9123 if (DECL_CLASS_SCOPE_P (decl)
9124 && CLASSTYPE_TEMPLATE_INFO (DECL_CONTEXT (decl))
9125 && uses_template_parms (DECL_CONTEXT (decl)))
9127 tree tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
9128 tree gen_args = tsubst (DECL_TI_ARGS (decl), args, complain, in_decl);
9129 r = retrieve_specialization (tmpl, gen_args, false);
9131 else if (DECL_FUNCTION_SCOPE_P (decl)
9132 && DECL_TEMPLATE_INFO (DECL_CONTEXT (decl))
9133 && uses_template_parms (DECL_TI_ARGS (DECL_CONTEXT (decl))))
9134 r = retrieve_local_specialization (decl);
9136 /* The typedef is from a non-template context. */
9142 r = cp_build_qualified_type_real
9143 (r, cp_type_quals (t) | cp_type_quals (r),
9144 complain | tf_ignore_bad_quals);
9147 /* Else we must be instantiating the typedef, so fall through. */
9151 && TREE_CODE (t) != TYPENAME_TYPE
9152 && TREE_CODE (t) != IDENTIFIER_NODE
9153 && TREE_CODE (t) != FUNCTION_TYPE
9154 && TREE_CODE (t) != METHOD_TYPE)
9155 type = tsubst (type, args, complain, in_decl);
9156 if (type == error_mark_node)
9157 return error_mark_node;
9159 switch (TREE_CODE (t))
9164 return tsubst_aggr_type (t, args, complain, in_decl,
9165 /*entering_scope=*/0);
9168 case IDENTIFIER_NODE:
9180 if (t == integer_type_node)
9183 if (TREE_CODE (TYPE_MIN_VALUE (t)) == INTEGER_CST
9184 && TREE_CODE (TYPE_MAX_VALUE (t)) == INTEGER_CST)
9188 tree max, omax = TREE_OPERAND (TYPE_MAX_VALUE (t), 0);
9190 max = tsubst_expr (omax, args, complain, in_decl,
9191 /*integral_constant_expression_p=*/false);
9193 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
9195 if (TREE_CODE (max) == NOP_EXPR
9196 && TREE_SIDE_EFFECTS (omax)
9197 && !TREE_TYPE (max))
9198 TREE_TYPE (max) = TREE_TYPE (TREE_OPERAND (max, 0));
9200 max = fold_decl_constant_value (max);
9202 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
9203 with TREE_SIDE_EFFECTS that indicates this is not an integral
9204 constant expression. */
9205 if (processing_template_decl
9206 && TREE_SIDE_EFFECTS (omax) && TREE_CODE (omax) == NOP_EXPR)
9208 gcc_assert (TREE_CODE (max) == NOP_EXPR);
9209 TREE_SIDE_EFFECTS (max) = 1;
9212 if (TREE_CODE (max) != INTEGER_CST
9213 && !at_function_scope_p ()
9214 && !TREE_SIDE_EFFECTS (max)
9215 && !value_dependent_expression_p (max))
9217 if (complain & tf_error)
9218 error ("array bound is not an integer constant");
9219 return error_mark_node;
9224 Type deduction may fail for any of the following
9227 Attempting to create an array with a size that is
9228 zero or negative. */
9229 if (integer_zerop (max) && !(complain & tf_error))
9230 /* We must fail if performing argument deduction (as
9231 indicated by the state of complain), so that
9232 another substitution can be found. */
9233 return error_mark_node;
9234 else if (TREE_CODE (max) == INTEGER_CST
9235 && INT_CST_LT (max, integer_zero_node))
9237 if (complain & tf_error)
9238 error ("creating array with negative size (%qE)", max);
9240 return error_mark_node;
9243 return compute_array_index_type (NULL_TREE, max);
9246 case TEMPLATE_TYPE_PARM:
9247 case TEMPLATE_TEMPLATE_PARM:
9248 case BOUND_TEMPLATE_TEMPLATE_PARM:
9249 case TEMPLATE_PARM_INDEX:
9254 tree arg = NULL_TREE;
9258 gcc_assert (TREE_VEC_LENGTH (args) > 0);
9259 template_parm_level_and_index (t, &level, &idx);
9261 levels = TMPL_ARGS_DEPTH (args);
9262 if (level <= levels)
9264 arg = TMPL_ARG (args, level, idx);
9266 if (arg && TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
9267 /* See through ARGUMENT_PACK_SELECT arguments. */
9268 arg = ARGUMENT_PACK_SELECT_ARG (arg);
9271 if (arg == error_mark_node)
9272 return error_mark_node;
9273 else if (arg != NULL_TREE)
9275 if (ARGUMENT_PACK_P (arg))
9276 /* If ARG is an argument pack, we don't actually want to
9277 perform a substitution here, because substitutions
9278 for argument packs are only done
9279 element-by-element. We can get to this point when
9280 substituting the type of a non-type template
9281 parameter pack, when that type actually contains
9282 template parameter packs from an outer template, e.g.,
9284 template<typename... Types> struct A {
9285 template<Types... Values> struct B { };
9289 if (TREE_CODE (t) == TEMPLATE_TYPE_PARM)
9292 gcc_assert (TYPE_P (arg));
9294 /* cv-quals from the template are discarded when
9295 substituting in a function or reference type. */
9296 if (TREE_CODE (arg) == FUNCTION_TYPE
9297 || TREE_CODE (arg) == METHOD_TYPE
9298 || TREE_CODE (arg) == REFERENCE_TYPE)
9299 quals = cp_type_quals (arg);
9301 quals = cp_type_quals (arg) | cp_type_quals (t);
9303 return cp_build_qualified_type_real
9304 (arg, quals, complain | tf_ignore_bad_quals);
9306 else if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
9308 /* We are processing a type constructed from a
9309 template template parameter. */
9310 tree argvec = tsubst (TYPE_TI_ARGS (t),
9311 args, complain, in_decl);
9312 if (argvec == error_mark_node)
9313 return error_mark_node;
9315 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
9316 are resolving nested-types in the signature of a
9317 member function templates. Otherwise ARG is a
9318 TEMPLATE_DECL and is the real template to be
9320 if (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
9321 arg = TYPE_NAME (arg);
9323 r = lookup_template_class (arg,
9326 /*entering_scope=*/0,
9328 return cp_build_qualified_type_real
9329 (r, TYPE_QUALS (t), complain);
9332 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
9337 /* This can happen during the attempted tsubst'ing in
9338 unify. This means that we don't yet have any information
9339 about the template parameter in question. */
9342 /* If we get here, we must have been looking at a parm for a
9343 more deeply nested template. Make a new version of this
9344 template parameter, but with a lower level. */
9345 switch (TREE_CODE (t))
9347 case TEMPLATE_TYPE_PARM:
9348 case TEMPLATE_TEMPLATE_PARM:
9349 case BOUND_TEMPLATE_TEMPLATE_PARM:
9350 if (cp_type_quals (t))
9352 r = tsubst (TYPE_MAIN_VARIANT (t), args, complain, in_decl);
9353 r = cp_build_qualified_type_real
9354 (r, cp_type_quals (t),
9355 complain | (TREE_CODE (t) == TEMPLATE_TYPE_PARM
9356 ? tf_ignore_bad_quals : 0));
9361 TEMPLATE_TYPE_PARM_INDEX (r)
9362 = reduce_template_parm_level (TEMPLATE_TYPE_PARM_INDEX (t),
9363 r, levels, args, complain);
9364 TYPE_STUB_DECL (r) = TYPE_NAME (r) = TEMPLATE_TYPE_DECL (r);
9365 TYPE_MAIN_VARIANT (r) = r;
9366 TYPE_POINTER_TO (r) = NULL_TREE;
9367 TYPE_REFERENCE_TO (r) = NULL_TREE;
9369 if (TREE_CODE (r) == TEMPLATE_TEMPLATE_PARM)
9370 /* We have reduced the level of the template
9371 template parameter, but not the levels of its
9372 template parameters, so canonical_type_parameter
9373 will not be able to find the canonical template
9374 template parameter for this level. Thus, we
9375 require structural equality checking to compare
9376 TEMPLATE_TEMPLATE_PARMs. */
9377 SET_TYPE_STRUCTURAL_EQUALITY (r);
9378 else if (TYPE_STRUCTURAL_EQUALITY_P (t))
9379 SET_TYPE_STRUCTURAL_EQUALITY (r);
9381 TYPE_CANONICAL (r) = canonical_type_parameter (r);
9383 if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
9385 tree argvec = tsubst (TYPE_TI_ARGS (t), args,
9387 if (argvec == error_mark_node)
9388 return error_mark_node;
9390 TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (r)
9391 = tree_cons (TYPE_TI_TEMPLATE (t), argvec, NULL_TREE);
9396 case TEMPLATE_PARM_INDEX:
9397 r = reduce_template_parm_level (t, type, levels, args, complain);
9409 tree purpose, value, chain;
9411 if (t == void_list_node)
9414 purpose = TREE_PURPOSE (t);
9417 purpose = tsubst (purpose, args, complain, in_decl);
9418 if (purpose == error_mark_node)
9419 return error_mark_node;
9421 value = TREE_VALUE (t);
9424 value = tsubst (value, args, complain, in_decl);
9425 if (value == error_mark_node)
9426 return error_mark_node;
9428 chain = TREE_CHAIN (t);
9429 if (chain && chain != void_type_node)
9431 chain = tsubst (chain, args, complain, in_decl);
9432 if (chain == error_mark_node)
9433 return error_mark_node;
9435 if (purpose == TREE_PURPOSE (t)
9436 && value == TREE_VALUE (t)
9437 && chain == TREE_CHAIN (t))
9439 return hash_tree_cons (purpose, value, chain);
9443 /* We should never be tsubsting a binfo. */
9447 /* A vector of template arguments. */
9449 return tsubst_template_args (t, args, complain, in_decl);
9452 case REFERENCE_TYPE:
9454 enum tree_code code;
9456 if (type == TREE_TYPE (t) && TREE_CODE (type) != METHOD_TYPE)
9459 code = TREE_CODE (t);
9464 Type deduction may fail for any of the following
9467 -- Attempting to create a pointer to reference type.
9468 -- Attempting to create a reference to a reference type or
9469 a reference to void.
9471 Core issue 106 says that creating a reference to a reference
9472 during instantiation is no longer a cause for failure. We
9473 only enforce this check in strict C++98 mode. */
9474 if ((TREE_CODE (type) == REFERENCE_TYPE
9475 && (((cxx_dialect == cxx98) && flag_iso) || code != REFERENCE_TYPE))
9476 || (code == REFERENCE_TYPE && TREE_CODE (type) == VOID_TYPE))
9478 static location_t last_loc;
9480 /* We keep track of the last time we issued this error
9481 message to avoid spewing a ton of messages during a
9482 single bad template instantiation. */
9483 if (complain & tf_error
9484 && last_loc != input_location)
9486 if (TREE_CODE (type) == VOID_TYPE)
9487 error ("forming reference to void");
9489 error ("forming %s to reference type %qT",
9490 (code == POINTER_TYPE) ? "pointer" : "reference",
9492 last_loc = input_location;
9495 return error_mark_node;
9497 else if (code == POINTER_TYPE)
9499 r = build_pointer_type (type);
9500 if (TREE_CODE (type) == METHOD_TYPE)
9501 r = build_ptrmemfunc_type (r);
9503 else if (TREE_CODE (type) == REFERENCE_TYPE)
9504 /* In C++0x, during template argument substitution, when there is an
9505 attempt to create a reference to a reference type, reference
9506 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
9508 "If a template-argument for a template-parameter T names a type
9509 that is a reference to a type A, an attempt to create the type
9510 'lvalue reference to cv T' creates the type 'lvalue reference to
9511 A,' while an attempt to create the type type rvalue reference to
9512 cv T' creates the type T"
9514 r = cp_build_reference_type
9516 TYPE_REF_IS_RVALUE (t) && TYPE_REF_IS_RVALUE (type));
9518 r = cp_build_reference_type (type, TYPE_REF_IS_RVALUE (t));
9519 r = cp_build_qualified_type_real (r, TYPE_QUALS (t), complain);
9521 if (r != error_mark_node)
9522 /* Will this ever be needed for TYPE_..._TO values? */
9529 r = tsubst (TYPE_OFFSET_BASETYPE (t), args, complain, in_decl);
9530 if (r == error_mark_node || !MAYBE_CLASS_TYPE_P (r))
9534 Type deduction may fail for any of the following
9537 -- Attempting to create "pointer to member of T" when T
9538 is not a class type. */
9539 if (complain & tf_error)
9540 error ("creating pointer to member of non-class type %qT", r);
9541 return error_mark_node;
9543 if (TREE_CODE (type) == REFERENCE_TYPE)
9545 if (complain & tf_error)
9546 error ("creating pointer to member reference type %qT", type);
9547 return error_mark_node;
9549 if (TREE_CODE (type) == VOID_TYPE)
9551 if (complain & tf_error)
9552 error ("creating pointer to member of type void");
9553 return error_mark_node;
9555 gcc_assert (TREE_CODE (type) != METHOD_TYPE);
9556 if (TREE_CODE (type) == FUNCTION_TYPE)
9558 /* The type of the implicit object parameter gets its
9559 cv-qualifiers from the FUNCTION_TYPE. */
9561 tree this_type = cp_build_qualified_type (TYPE_MAIN_VARIANT (r),
9562 cp_type_quals (type));
9564 method_type = build_method_type_directly (this_type,
9566 TYPE_ARG_TYPES (type));
9567 memptr = build_ptrmemfunc_type (build_pointer_type (method_type));
9568 return cp_build_qualified_type_real (memptr, cp_type_quals (t),
9572 return cp_build_qualified_type_real (build_ptrmem_type (r, type),
9581 fntype = tsubst_function_type (t, args, complain, in_decl);
9582 if (fntype == error_mark_node)
9583 return error_mark_node;
9585 /* Substitute the exception specification. */
9586 specs = tsubst_exception_specification (t, args, complain,
9588 if (specs == error_mark_node)
9589 return error_mark_node;
9591 fntype = build_exception_variant (fntype, specs);
9596 tree domain = tsubst (TYPE_DOMAIN (t), args, complain, in_decl);
9597 if (domain == error_mark_node)
9598 return error_mark_node;
9600 /* As an optimization, we avoid regenerating the array type if
9601 it will obviously be the same as T. */
9602 if (type == TREE_TYPE (t) && domain == TYPE_DOMAIN (t))
9605 /* These checks should match the ones in grokdeclarator.
9609 The deduction may fail for any of the following reasons:
9611 -- Attempting to create an array with an element type that
9612 is void, a function type, or a reference type, or [DR337]
9613 an abstract class type. */
9614 if (TREE_CODE (type) == VOID_TYPE
9615 || TREE_CODE (type) == FUNCTION_TYPE
9616 || TREE_CODE (type) == REFERENCE_TYPE)
9618 if (complain & tf_error)
9619 error ("creating array of %qT", type);
9620 return error_mark_node;
9622 if (CLASS_TYPE_P (type) && CLASSTYPE_PURE_VIRTUALS (type))
9624 if (complain & tf_error)
9625 error ("creating array of %qT, which is an abstract class type",
9627 return error_mark_node;
9630 r = build_cplus_array_type (type, domain);
9632 if (TYPE_USER_ALIGN (t))
9634 TYPE_ALIGN (r) = TYPE_ALIGN (t);
9635 TYPE_USER_ALIGN (r) = 1;
9644 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
9645 tree e2 = tsubst (TREE_OPERAND (t, 1), args, complain, in_decl);
9647 if (e1 == error_mark_node || e2 == error_mark_node)
9648 return error_mark_node;
9650 return fold_build2 (TREE_CODE (t), TREE_TYPE (t), e1, e2);
9656 tree e = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
9657 if (e == error_mark_node)
9658 return error_mark_node;
9660 return fold_build1 (TREE_CODE (t), TREE_TYPE (t), e);
9665 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
9666 in_decl, /*entering_scope=*/1);
9667 tree f = tsubst_copy (TYPENAME_TYPE_FULLNAME (t), args,
9670 if (ctx == error_mark_node || f == error_mark_node)
9671 return error_mark_node;
9673 if (!MAYBE_CLASS_TYPE_P (ctx))
9675 if (complain & tf_error)
9676 error ("%qT is not a class, struct, or union type", ctx);
9677 return error_mark_node;
9679 else if (!uses_template_parms (ctx) && !TYPE_BEING_DEFINED (ctx))
9681 /* Normally, make_typename_type does not require that the CTX
9682 have complete type in order to allow things like:
9684 template <class T> struct S { typename S<T>::X Y; };
9686 But, such constructs have already been resolved by this
9687 point, so here CTX really should have complete type, unless
9688 it's a partial instantiation. */
9689 ctx = complete_type (ctx);
9690 if (!COMPLETE_TYPE_P (ctx))
9692 if (complain & tf_error)
9693 cxx_incomplete_type_error (NULL_TREE, ctx);
9694 return error_mark_node;
9698 f = make_typename_type (ctx, f, typename_type,
9699 (complain & tf_error) | tf_keep_type_decl);
9700 if (f == error_mark_node)
9702 if (TREE_CODE (f) == TYPE_DECL)
9704 complain |= tf_ignore_bad_quals;
9708 if (TREE_CODE (f) != TYPENAME_TYPE)
9710 if (TYPENAME_IS_ENUM_P (t) && TREE_CODE (f) != ENUMERAL_TYPE)
9711 error ("%qT resolves to %qT, which is not an enumeration type",
9713 else if (TYPENAME_IS_CLASS_P (t) && !CLASS_TYPE_P (f))
9714 error ("%qT resolves to %qT, which is is not a class type",
9718 return cp_build_qualified_type_real
9719 (f, cp_type_quals (f) | cp_type_quals (t), complain);
9722 case UNBOUND_CLASS_TEMPLATE:
9724 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
9725 in_decl, /*entering_scope=*/1);
9726 tree name = TYPE_IDENTIFIER (t);
9727 tree parm_list = DECL_TEMPLATE_PARMS (TYPE_NAME (t));
9729 if (ctx == error_mark_node || name == error_mark_node)
9730 return error_mark_node;
9733 parm_list = tsubst_template_parms (parm_list, args, complain);
9734 return make_unbound_class_template (ctx, name, parm_list, complain);
9744 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
9745 tree e2 = tsubst_expr (TREE_OPERAND (t, 1), args, complain, in_decl,
9746 /*integral_constant_expression_p=*/false);
9747 if (e1 == error_mark_node || e2 == error_mark_node)
9748 return error_mark_node;
9750 return build_nt (ARRAY_REF, e1, e2, NULL_TREE, NULL_TREE);
9755 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
9756 tree e2 = tsubst (TREE_OPERAND (t, 1), args, complain, in_decl);
9757 if (e1 == error_mark_node || e2 == error_mark_node)
9758 return error_mark_node;
9760 return build_qualified_name (/*type=*/NULL_TREE,
9761 e1, e2, QUALIFIED_NAME_IS_TEMPLATE (t));
9768 type = finish_typeof (tsubst_expr
9769 (TYPEOF_TYPE_EXPR (t), args,
9771 /*integral_constant_expression_p=*/false));
9772 return cp_build_qualified_type_real (type,
9774 | cp_type_quals (type),
9782 ++cp_unevaluated_operand;
9783 ++c_inhibit_evaluation_warnings;
9785 type = tsubst_expr (DECLTYPE_TYPE_EXPR (t), args,
9787 /*integral_constant_expression_p=*/false);
9789 --cp_unevaluated_operand;
9790 --c_inhibit_evaluation_warnings;
9793 finish_decltype_type (type,
9794 DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t));
9795 return cp_build_qualified_type_real (type,
9797 | cp_type_quals (type),
9801 case TYPE_ARGUMENT_PACK:
9802 case NONTYPE_ARGUMENT_PACK:
9804 tree r = make_node (TREE_CODE (t));
9806 tsubst_template_args (ARGUMENT_PACK_ARGS (t),
9810 SET_ARGUMENT_PACK_ARGS (r, packed_out);
9812 /* For template nontype argument packs, also substitute into
9814 if (TREE_CODE (t) == NONTYPE_ARGUMENT_PACK)
9815 TREE_TYPE (r) = tsubst (TREE_TYPE (t), args, complain, in_decl);
9822 sorry ("use of %qs in template",
9823 tree_code_name [(int) TREE_CODE (t)]);
9824 return error_mark_node;
9828 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
9829 type of the expression on the left-hand side of the "." or "->"
9833 tsubst_baselink (tree baselink, tree object_type,
9834 tree args, tsubst_flags_t complain, tree in_decl)
9837 tree qualifying_scope;
9840 tree template_args = 0;
9841 bool template_id_p = false;
9843 /* A baselink indicates a function from a base class. Both the
9844 BASELINK_ACCESS_BINFO and the base class referenced may
9845 indicate bases of the template class, rather than the
9846 instantiated class. In addition, lookups that were not
9847 ambiguous before may be ambiguous now. Therefore, we perform
9848 the lookup again. */
9849 qualifying_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (baselink));
9850 qualifying_scope = tsubst (qualifying_scope, args,
9852 fns = BASELINK_FUNCTIONS (baselink);
9853 optype = BASELINK_OPTYPE (baselink);
9854 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
9856 template_id_p = true;
9857 template_args = TREE_OPERAND (fns, 1);
9858 fns = TREE_OPERAND (fns, 0);
9860 template_args = tsubst_template_args (template_args, args,
9863 name = DECL_NAME (get_first_fn (fns));
9864 baselink = lookup_fnfields (qualifying_scope, name, /*protect=*/1);
9866 /* If lookup found a single function, mark it as used at this
9867 point. (If it lookup found multiple functions the one selected
9868 later by overload resolution will be marked as used at that
9870 if (BASELINK_P (baselink))
9871 fns = BASELINK_FUNCTIONS (baselink);
9872 if (!template_id_p && !really_overloaded_fn (fns))
9873 mark_used (OVL_CURRENT (fns));
9875 /* Add back the template arguments, if present. */
9876 if (BASELINK_P (baselink) && template_id_p)
9877 BASELINK_FUNCTIONS (baselink)
9878 = build_nt (TEMPLATE_ID_EXPR,
9879 BASELINK_FUNCTIONS (baselink),
9881 /* Update the conversion operator type. */
9882 BASELINK_OPTYPE (baselink)
9883 = tsubst (optype, args, complain, in_decl);
9886 object_type = current_class_type;
9887 return adjust_result_of_qualified_name_lookup (baselink,
9892 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
9893 true if the qualified-id will be a postfix-expression in-and-of
9894 itself; false if more of the postfix-expression follows the
9895 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
9899 tsubst_qualified_id (tree qualified_id, tree args,
9900 tsubst_flags_t complain, tree in_decl,
9901 bool done, bool address_p)
9909 gcc_assert (TREE_CODE (qualified_id) == SCOPE_REF);
9911 /* Figure out what name to look up. */
9912 name = TREE_OPERAND (qualified_id, 1);
9913 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
9916 template_args = TREE_OPERAND (name, 1);
9918 template_args = tsubst_template_args (template_args, args,
9920 name = TREE_OPERAND (name, 0);
9924 is_template = false;
9925 template_args = NULL_TREE;
9928 /* Substitute into the qualifying scope. When there are no ARGS, we
9929 are just trying to simplify a non-dependent expression. In that
9930 case the qualifying scope may be dependent, and, in any case,
9931 substituting will not help. */
9932 scope = TREE_OPERAND (qualified_id, 0);
9935 scope = tsubst (scope, args, complain, in_decl);
9936 expr = tsubst_copy (name, args, complain, in_decl);
9941 if (dependent_type_p (scope))
9943 tree type = NULL_TREE;
9944 if (DECL_P (expr) && !dependent_scope_p (scope))
9945 type = TREE_TYPE (expr);
9946 return build_qualified_name (type, scope, expr,
9947 QUALIFIED_NAME_IS_TEMPLATE (qualified_id));
9950 if (!BASELINK_P (name) && !DECL_P (expr))
9952 if (TREE_CODE (expr) == BIT_NOT_EXPR)
9954 /* A BIT_NOT_EXPR is used to represent a destructor. */
9955 if (!check_dtor_name (scope, TREE_OPERAND (expr, 0)))
9957 error ("qualifying type %qT does not match destructor name ~%qT",
9958 scope, TREE_OPERAND (expr, 0));
9959 expr = error_mark_node;
9962 expr = lookup_qualified_name (scope, complete_dtor_identifier,
9963 /*is_type_p=*/0, false);
9966 expr = lookup_qualified_name (scope, expr, /*is_type_p=*/0, false);
9967 if (TREE_CODE (TREE_CODE (expr) == TEMPLATE_DECL
9968 ? DECL_TEMPLATE_RESULT (expr) : expr) == TYPE_DECL)
9970 if (complain & tf_error)
9972 error ("dependent-name %qE is parsed as a non-type, but "
9973 "instantiation yields a type", qualified_id);
9974 inform (input_location, "say %<typename %E%> if a type is meant", qualified_id);
9976 return error_mark_node;
9982 check_accessibility_of_qualified_id (expr, /*object_type=*/NULL_TREE,
9984 /* Remember that there was a reference to this entity. */
9988 if (expr == error_mark_node || TREE_CODE (expr) == TREE_LIST)
9990 if (complain & tf_error)
9991 qualified_name_lookup_error (scope,
9992 TREE_OPERAND (qualified_id, 1),
9993 expr, input_location);
9994 return error_mark_node;
9998 expr = lookup_template_function (expr, template_args);
10000 if (expr == error_mark_node && complain & tf_error)
10001 qualified_name_lookup_error (scope, TREE_OPERAND (qualified_id, 1),
10002 expr, input_location);
10003 else if (TYPE_P (scope))
10005 expr = (adjust_result_of_qualified_name_lookup
10006 (expr, scope, current_class_type));
10007 expr = (finish_qualified_id_expr
10008 (scope, expr, done, address_p,
10009 QUALIFIED_NAME_IS_TEMPLATE (qualified_id),
10010 /*template_arg_p=*/false));
10013 /* Expressions do not generally have reference type. */
10014 if (TREE_CODE (expr) != SCOPE_REF
10015 /* However, if we're about to form a pointer-to-member, we just
10016 want the referenced member referenced. */
10017 && TREE_CODE (expr) != OFFSET_REF)
10018 expr = convert_from_reference (expr);
10023 /* Like tsubst, but deals with expressions. This function just replaces
10024 template parms; to finish processing the resultant expression, use
10028 tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl)
10030 enum tree_code code;
10033 if (t == NULL_TREE || t == error_mark_node || args == NULL_TREE)
10036 code = TREE_CODE (t);
10041 r = retrieve_local_specialization (t);
10046 /* This can happen for a parameter name used later in a function
10047 declaration (such as in a late-specified return type). Just
10048 make a dummy decl, since it's only used for its type. */
10049 gcc_assert (cp_unevaluated_operand != 0);
10050 /* We copy T because want to tsubst the PARM_DECL only,
10051 not the following PARM_DECLs that are chained to T. */
10053 r = tsubst_decl (c, args, complain);
10054 /* Give it the template pattern as its context; its true context
10055 hasn't been instantiated yet and this is good enough for
10057 DECL_CONTEXT (r) = DECL_CONTEXT (t);
10060 if (TREE_CODE (r) == ARGUMENT_PACK_SELECT)
10061 r = ARGUMENT_PACK_SELECT_ARG (r);
10070 if (DECL_TEMPLATE_PARM_P (t))
10071 return tsubst_copy (DECL_INITIAL (t), args, complain, in_decl);
10072 /* There is no need to substitute into namespace-scope
10074 if (DECL_NAMESPACE_SCOPE_P (t))
10076 /* If ARGS is NULL, then T is known to be non-dependent. */
10077 if (args == NULL_TREE)
10078 return integral_constant_value (t);
10080 /* Unfortunately, we cannot just call lookup_name here.
10083 template <int I> int f() {
10085 struct S { void g() { E e = a; } };
10088 When we instantiate f<7>::S::g(), say, lookup_name is not
10089 clever enough to find f<7>::a. */
10091 = tsubst_aggr_type (TREE_TYPE (t), args, complain, in_decl,
10092 /*entering_scope=*/0);
10094 for (v = TYPE_VALUES (enum_type);
10096 v = TREE_CHAIN (v))
10097 if (TREE_PURPOSE (v) == DECL_NAME (t))
10098 return TREE_VALUE (v);
10100 /* We didn't find the name. That should never happen; if
10101 name-lookup found it during preliminary parsing, we
10102 should find it again here during instantiation. */
10103 gcc_unreachable ();
10108 if (DECL_CONTEXT (t))
10112 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args, complain, in_decl,
10113 /*entering_scope=*/1);
10114 if (ctx != DECL_CONTEXT (t))
10116 tree r = lookup_field (ctx, DECL_NAME (t), 0, false);
10119 if (complain & tf_error)
10120 error ("using invalid field %qD", t);
10121 return error_mark_node;
10130 case FUNCTION_DECL:
10131 if ((DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t))
10132 || local_variable_p (t))
10133 t = tsubst (t, args, complain, in_decl);
10138 return tsubst_baselink (t, current_class_type, args, complain, in_decl);
10140 case TEMPLATE_DECL:
10141 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
10142 return tsubst (TREE_TYPE (DECL_TEMPLATE_RESULT (t)),
10143 args, complain, in_decl);
10144 else if (DECL_FUNCTION_TEMPLATE_P (t) && DECL_MEMBER_TEMPLATE_P (t))
10145 return tsubst (t, args, complain, in_decl);
10146 else if (DECL_CLASS_SCOPE_P (t)
10147 && uses_template_parms (DECL_CONTEXT (t)))
10149 /* Template template argument like the following example need
10152 template <template <class> class TT> struct C {};
10153 template <class T> struct D {
10154 template <class U> struct E {};
10159 We are processing the template argument `E' in #1 for
10160 the template instantiation #2. Originally, `E' is a
10161 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
10162 have to substitute this with one having context `D<int>'. */
10164 tree context = tsubst (DECL_CONTEXT (t), args, complain, in_decl);
10165 return lookup_field (context, DECL_NAME(t), 0, false);
10168 /* Ordinary template template argument. */
10172 case REINTERPRET_CAST_EXPR:
10173 case CONST_CAST_EXPR:
10174 case STATIC_CAST_EXPR:
10175 case DYNAMIC_CAST_EXPR:
10178 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
10179 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
10182 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
10184 /* We only want to compute the number of arguments. */
10185 tree expanded = tsubst_pack_expansion (TREE_OPERAND (t, 0), args,
10186 complain, in_decl);
10189 if (TREE_CODE (expanded) == TREE_VEC)
10190 len = TREE_VEC_LENGTH (expanded);
10192 if (expanded == error_mark_node)
10193 return error_mark_node;
10194 else if (PACK_EXPANSION_P (expanded)
10195 || (TREE_CODE (expanded) == TREE_VEC
10197 && PACK_EXPANSION_P (TREE_VEC_ELT (expanded, len-1))))
10199 if (TREE_CODE (expanded) == TREE_VEC)
10200 expanded = TREE_VEC_ELT (expanded, len - 1);
10202 if (TYPE_P (expanded))
10203 return cxx_sizeof_or_alignof_type (expanded, SIZEOF_EXPR,
10204 complain & tf_error);
10206 return cxx_sizeof_or_alignof_expr (expanded, SIZEOF_EXPR,
10207 complain & tf_error);
10210 return build_int_cst (size_type_node, len);
10216 case TRUTH_NOT_EXPR:
10219 case UNARY_PLUS_EXPR: /* Unary + */
10224 case REALPART_EXPR:
10225 case IMAGPART_EXPR:
10227 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
10228 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
10230 case COMPONENT_REF:
10235 object = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
10236 name = TREE_OPERAND (t, 1);
10237 if (TREE_CODE (name) == BIT_NOT_EXPR)
10239 name = tsubst_copy (TREE_OPERAND (name, 0), args,
10240 complain, in_decl);
10241 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
10243 else if (TREE_CODE (name) == SCOPE_REF
10244 && TREE_CODE (TREE_OPERAND (name, 1)) == BIT_NOT_EXPR)
10246 tree base = tsubst_copy (TREE_OPERAND (name, 0), args,
10247 complain, in_decl);
10248 name = TREE_OPERAND (name, 1);
10249 name = tsubst_copy (TREE_OPERAND (name, 0), args,
10250 complain, in_decl);
10251 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
10252 name = build_qualified_name (/*type=*/NULL_TREE,
10254 /*template_p=*/false);
10256 else if (TREE_CODE (name) == BASELINK)
10257 name = tsubst_baselink (name,
10258 non_reference (TREE_TYPE (object)),
10262 name = tsubst_copy (name, args, complain, in_decl);
10263 return build_nt (COMPONENT_REF, object, name, NULL_TREE);
10269 case TRUNC_DIV_EXPR:
10270 case CEIL_DIV_EXPR:
10271 case FLOOR_DIV_EXPR:
10272 case ROUND_DIV_EXPR:
10273 case EXACT_DIV_EXPR:
10277 case TRUNC_MOD_EXPR:
10278 case FLOOR_MOD_EXPR:
10279 case TRUTH_ANDIF_EXPR:
10280 case TRUTH_ORIF_EXPR:
10281 case TRUTH_AND_EXPR:
10282 case TRUTH_OR_EXPR:
10295 case COMPOUND_EXPR:
10298 case PREDECREMENT_EXPR:
10299 case PREINCREMENT_EXPR:
10300 case POSTDECREMENT_EXPR:
10301 case POSTINCREMENT_EXPR:
10303 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
10304 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
10307 return build_qualified_name (/*type=*/NULL_TREE,
10308 tsubst_copy (TREE_OPERAND (t, 0),
10309 args, complain, in_decl),
10310 tsubst_copy (TREE_OPERAND (t, 1),
10311 args, complain, in_decl),
10312 QUALIFIED_NAME_IS_TEMPLATE (t));
10317 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
10318 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
10319 NULL_TREE, NULL_TREE);
10323 int n = VL_EXP_OPERAND_LENGTH (t);
10324 tree result = build_vl_exp (CALL_EXPR, n);
10326 for (i = 0; i < n; i++)
10327 TREE_OPERAND (t, i) = tsubst_copy (TREE_OPERAND (t, i), args,
10328 complain, in_decl);
10334 case PSEUDO_DTOR_EXPR:
10337 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
10338 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
10339 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
10340 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
10347 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
10348 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
10349 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
10350 NEW_EXPR_USE_GLOBAL (r) = NEW_EXPR_USE_GLOBAL (t);
10357 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
10358 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
10359 DELETE_EXPR_USE_GLOBAL (r) = DELETE_EXPR_USE_GLOBAL (t);
10360 DELETE_EXPR_USE_VEC (r) = DELETE_EXPR_USE_VEC (t);
10364 case TEMPLATE_ID_EXPR:
10366 /* Substituted template arguments */
10367 tree fn = TREE_OPERAND (t, 0);
10368 tree targs = TREE_OPERAND (t, 1);
10370 fn = tsubst_copy (fn, args, complain, in_decl);
10372 targs = tsubst_template_args (targs, args, complain, in_decl);
10374 return lookup_template_function (fn, targs);
10379 tree purpose, value, chain;
10381 if (t == void_list_node)
10384 purpose = TREE_PURPOSE (t);
10386 purpose = tsubst_copy (purpose, args, complain, in_decl);
10387 value = TREE_VALUE (t);
10389 value = tsubst_copy (value, args, complain, in_decl);
10390 chain = TREE_CHAIN (t);
10391 if (chain && chain != void_type_node)
10392 chain = tsubst_copy (chain, args, complain, in_decl);
10393 if (purpose == TREE_PURPOSE (t)
10394 && value == TREE_VALUE (t)
10395 && chain == TREE_CHAIN (t))
10397 return tree_cons (purpose, value, chain);
10402 case ENUMERAL_TYPE:
10404 case TEMPLATE_TYPE_PARM:
10405 case TEMPLATE_TEMPLATE_PARM:
10406 case BOUND_TEMPLATE_TEMPLATE_PARM:
10407 case TEMPLATE_PARM_INDEX:
10409 case REFERENCE_TYPE:
10411 case FUNCTION_TYPE:
10414 case TYPENAME_TYPE:
10415 case UNBOUND_CLASS_TEMPLATE:
10417 case DECLTYPE_TYPE:
10419 return tsubst (t, args, complain, in_decl);
10421 case IDENTIFIER_NODE:
10422 if (IDENTIFIER_TYPENAME_P (t))
10424 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10425 return mangle_conv_op_name_for_type (new_type);
10431 /* This is handled by tsubst_copy_and_build. */
10432 gcc_unreachable ();
10435 return build_x_va_arg (tsubst_copy (TREE_OPERAND (t, 0), args, complain,
10437 tsubst (TREE_TYPE (t), args, complain, in_decl));
10439 case CLEANUP_POINT_EXPR:
10440 /* We shouldn't have built any of these during initial template
10441 generation. Instead, they should be built during instantiation
10442 in response to the saved STMT_IS_FULL_EXPR_P setting. */
10443 gcc_unreachable ();
10446 mark_used (TREE_OPERAND (t, 1));
10449 case EXPR_PACK_EXPANSION:
10450 error ("invalid use of pack expansion expression");
10451 return error_mark_node;
10453 case NONTYPE_ARGUMENT_PACK:
10454 error ("use %<...%> to expand argument pack");
10455 return error_mark_node;
10462 /* Like tsubst_copy, but specifically for OpenMP clauses. */
10465 tsubst_omp_clauses (tree clauses, tree args, tsubst_flags_t complain,
10468 tree new_clauses = NULL, nc, oc;
10470 for (oc = clauses; oc ; oc = OMP_CLAUSE_CHAIN (oc))
10472 nc = copy_node (oc);
10473 OMP_CLAUSE_CHAIN (nc) = new_clauses;
10476 switch (OMP_CLAUSE_CODE (nc))
10478 case OMP_CLAUSE_LASTPRIVATE:
10479 if (OMP_CLAUSE_LASTPRIVATE_STMT (oc))
10481 OMP_CLAUSE_LASTPRIVATE_STMT (nc) = push_stmt_list ();
10482 tsubst_expr (OMP_CLAUSE_LASTPRIVATE_STMT (oc), args, complain,
10483 in_decl, /*integral_constant_expression_p=*/false);
10484 OMP_CLAUSE_LASTPRIVATE_STMT (nc)
10485 = pop_stmt_list (OMP_CLAUSE_LASTPRIVATE_STMT (nc));
10488 case OMP_CLAUSE_PRIVATE:
10489 case OMP_CLAUSE_SHARED:
10490 case OMP_CLAUSE_FIRSTPRIVATE:
10491 case OMP_CLAUSE_REDUCTION:
10492 case OMP_CLAUSE_COPYIN:
10493 case OMP_CLAUSE_COPYPRIVATE:
10494 case OMP_CLAUSE_IF:
10495 case OMP_CLAUSE_NUM_THREADS:
10496 case OMP_CLAUSE_SCHEDULE:
10497 case OMP_CLAUSE_COLLAPSE:
10498 OMP_CLAUSE_OPERAND (nc, 0)
10499 = tsubst_expr (OMP_CLAUSE_OPERAND (oc, 0), args, complain,
10500 in_decl, /*integral_constant_expression_p=*/false);
10502 case OMP_CLAUSE_NOWAIT:
10503 case OMP_CLAUSE_ORDERED:
10504 case OMP_CLAUSE_DEFAULT:
10505 case OMP_CLAUSE_UNTIED:
10508 gcc_unreachable ();
10512 return finish_omp_clauses (nreverse (new_clauses));
10515 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
10518 tsubst_copy_asm_operands (tree t, tree args, tsubst_flags_t complain,
10521 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
10523 tree purpose, value, chain;
10528 if (TREE_CODE (t) != TREE_LIST)
10529 return tsubst_copy_and_build (t, args, complain, in_decl,
10530 /*function_p=*/false,
10531 /*integral_constant_expression_p=*/false);
10533 if (t == void_list_node)
10536 purpose = TREE_PURPOSE (t);
10538 purpose = RECUR (purpose);
10539 value = TREE_VALUE (t);
10541 value = RECUR (value);
10542 chain = TREE_CHAIN (t);
10543 if (chain && chain != void_type_node)
10544 chain = RECUR (chain);
10545 return tree_cons (purpose, value, chain);
10549 /* Substitute one OMP_FOR iterator. */
10552 tsubst_omp_for_iterator (tree t, int i, tree declv, tree initv,
10553 tree condv, tree incrv, tree *clauses,
10554 tree args, tsubst_flags_t complain, tree in_decl,
10555 bool integral_constant_expression_p)
10557 #define RECUR(NODE) \
10558 tsubst_expr ((NODE), args, complain, in_decl, \
10559 integral_constant_expression_p)
10560 tree decl, init, cond, incr, auto_node;
10562 init = TREE_VEC_ELT (OMP_FOR_INIT (t), i);
10563 gcc_assert (TREE_CODE (init) == MODIFY_EXPR);
10564 decl = RECUR (TREE_OPERAND (init, 0));
10565 init = TREE_OPERAND (init, 1);
10566 auto_node = type_uses_auto (TREE_TYPE (decl));
10567 if (auto_node && init)
10569 tree init_expr = init;
10570 if (TREE_CODE (init_expr) == DECL_EXPR)
10571 init_expr = DECL_INITIAL (DECL_EXPR_DECL (init_expr));
10572 init_expr = RECUR (init_expr);
10574 = do_auto_deduction (TREE_TYPE (decl), init_expr, auto_node);
10576 gcc_assert (!type_dependent_expression_p (decl));
10578 if (!CLASS_TYPE_P (TREE_TYPE (decl)))
10580 cond = RECUR (TREE_VEC_ELT (OMP_FOR_COND (t), i));
10581 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
10582 if (TREE_CODE (incr) == MODIFY_EXPR)
10583 incr = build_x_modify_expr (RECUR (TREE_OPERAND (incr, 0)), NOP_EXPR,
10584 RECUR (TREE_OPERAND (incr, 1)),
10587 incr = RECUR (incr);
10588 TREE_VEC_ELT (declv, i) = decl;
10589 TREE_VEC_ELT (initv, i) = init;
10590 TREE_VEC_ELT (condv, i) = cond;
10591 TREE_VEC_ELT (incrv, i) = incr;
10595 if (init && TREE_CODE (init) != DECL_EXPR)
10598 for (c = *clauses; c ; c = OMP_CLAUSE_CHAIN (c))
10600 if ((OMP_CLAUSE_CODE (c) == OMP_CLAUSE_PRIVATE
10601 || OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LASTPRIVATE)
10602 && OMP_CLAUSE_DECL (c) == decl)
10604 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_FIRSTPRIVATE
10605 && OMP_CLAUSE_DECL (c) == decl)
10606 error ("iteration variable %qD should not be firstprivate", decl);
10607 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_REDUCTION
10608 && OMP_CLAUSE_DECL (c) == decl)
10609 error ("iteration variable %qD should not be reduction", decl);
10613 c = build_omp_clause (input_location, OMP_CLAUSE_PRIVATE);
10614 OMP_CLAUSE_DECL (c) = decl;
10615 c = finish_omp_clauses (c);
10618 OMP_CLAUSE_CHAIN (c) = *clauses;
10623 cond = TREE_VEC_ELT (OMP_FOR_COND (t), i);
10624 if (COMPARISON_CLASS_P (cond))
10625 cond = build2 (TREE_CODE (cond), boolean_type_node,
10626 RECUR (TREE_OPERAND (cond, 0)),
10627 RECUR (TREE_OPERAND (cond, 1)));
10629 cond = RECUR (cond);
10630 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
10631 switch (TREE_CODE (incr))
10633 case PREINCREMENT_EXPR:
10634 case PREDECREMENT_EXPR:
10635 case POSTINCREMENT_EXPR:
10636 case POSTDECREMENT_EXPR:
10637 incr = build2 (TREE_CODE (incr), TREE_TYPE (decl),
10638 RECUR (TREE_OPERAND (incr, 0)), NULL_TREE);
10641 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
10642 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
10644 tree rhs = TREE_OPERAND (incr, 1);
10645 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
10646 RECUR (TREE_OPERAND (incr, 0)),
10647 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
10648 RECUR (TREE_OPERAND (rhs, 0)),
10649 RECUR (TREE_OPERAND (rhs, 1))));
10652 incr = RECUR (incr);
10655 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
10656 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
10658 tree lhs = RECUR (TREE_OPERAND (incr, 0));
10659 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl), lhs,
10660 build2 (TREE_CODE (TREE_OPERAND (incr, 1)),
10661 TREE_TYPE (decl), lhs,
10662 RECUR (TREE_OPERAND (incr, 2))));
10664 else if (TREE_CODE (TREE_OPERAND (incr, 1)) == NOP_EXPR
10665 && (TREE_CODE (TREE_OPERAND (incr, 2)) == PLUS_EXPR
10666 || (TREE_CODE (TREE_OPERAND (incr, 2)) == MINUS_EXPR)))
10668 tree rhs = TREE_OPERAND (incr, 2);
10669 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
10670 RECUR (TREE_OPERAND (incr, 0)),
10671 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
10672 RECUR (TREE_OPERAND (rhs, 0)),
10673 RECUR (TREE_OPERAND (rhs, 1))));
10676 incr = RECUR (incr);
10679 incr = RECUR (incr);
10683 TREE_VEC_ELT (declv, i) = decl;
10684 TREE_VEC_ELT (initv, i) = init;
10685 TREE_VEC_ELT (condv, i) = cond;
10686 TREE_VEC_ELT (incrv, i) = incr;
10690 /* Like tsubst_copy for expressions, etc. but also does semantic
10694 tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl,
10695 bool integral_constant_expression_p)
10697 #define RECUR(NODE) \
10698 tsubst_expr ((NODE), args, complain, in_decl, \
10699 integral_constant_expression_p)
10703 if (t == NULL_TREE || t == error_mark_node)
10706 if (EXPR_HAS_LOCATION (t))
10707 input_location = EXPR_LOCATION (t);
10708 if (STATEMENT_CODE_P (TREE_CODE (t)))
10709 current_stmt_tree ()->stmts_are_full_exprs_p = STMT_IS_FULL_EXPR_P (t);
10711 switch (TREE_CODE (t))
10713 case STATEMENT_LIST:
10715 tree_stmt_iterator i;
10716 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
10717 RECUR (tsi_stmt (i));
10721 case CTOR_INITIALIZER:
10722 finish_mem_initializers (tsubst_initializer_list
10723 (TREE_OPERAND (t, 0), args));
10727 finish_return_stmt (RECUR (TREE_OPERAND (t, 0)));
10731 tmp = RECUR (EXPR_STMT_EXPR (t));
10732 if (EXPR_STMT_STMT_EXPR_RESULT (t))
10733 finish_stmt_expr_expr (tmp, cur_stmt_expr);
10735 finish_expr_stmt (tmp);
10739 do_using_directive (RECUR (USING_STMT_NAMESPACE (t)));
10747 decl = DECL_EXPR_DECL (t);
10748 if (TREE_CODE (decl) == LABEL_DECL)
10749 finish_label_decl (DECL_NAME (decl));
10750 else if (TREE_CODE (decl) == USING_DECL)
10752 tree scope = USING_DECL_SCOPE (decl);
10753 tree name = DECL_NAME (decl);
10756 scope = RECUR (scope);
10757 decl = lookup_qualified_name (scope, name,
10758 /*is_type_p=*/false,
10759 /*complain=*/false);
10760 if (decl == error_mark_node || TREE_CODE (decl) == TREE_LIST)
10761 qualified_name_lookup_error (scope, name, decl, input_location);
10763 do_local_using_decl (decl, scope, name);
10767 init = DECL_INITIAL (decl);
10768 decl = tsubst (decl, args, complain, in_decl);
10769 if (decl != error_mark_node)
10771 /* By marking the declaration as instantiated, we avoid
10772 trying to instantiate it. Since instantiate_decl can't
10773 handle local variables, and since we've already done
10774 all that needs to be done, that's the right thing to
10776 if (TREE_CODE (decl) == VAR_DECL)
10777 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
10778 if (TREE_CODE (decl) == VAR_DECL
10779 && ANON_AGGR_TYPE_P (TREE_TYPE (decl)))
10780 /* Anonymous aggregates are a special case. */
10781 finish_anon_union (decl);
10784 maybe_push_decl (decl);
10785 if (TREE_CODE (decl) == VAR_DECL
10786 && DECL_PRETTY_FUNCTION_P (decl))
10788 /* For __PRETTY_FUNCTION__ we have to adjust the
10790 const char *const name
10791 = cxx_printable_name (current_function_decl, 2);
10792 init = cp_fname_init (name, &TREE_TYPE (decl));
10796 tree t = RECUR (init);
10799 /* If we had an initializer but it
10800 instantiated to nothing,
10801 value-initialize the object. This will
10802 only occur when the initializer was a
10803 pack expansion where the parameter packs
10804 used in that expansion were of length
10806 init = build_value_init (TREE_TYPE (decl));
10811 cp_finish_decl (decl, init, false, NULL_TREE, 0);
10816 /* A DECL_EXPR can also be used as an expression, in the condition
10817 clause of an if/for/while construct. */
10822 stmt = begin_for_stmt ();
10823 RECUR (FOR_INIT_STMT (t));
10824 finish_for_init_stmt (stmt);
10825 tmp = RECUR (FOR_COND (t));
10826 finish_for_cond (tmp, stmt);
10827 tmp = RECUR (FOR_EXPR (t));
10828 finish_for_expr (tmp, stmt);
10829 RECUR (FOR_BODY (t));
10830 finish_for_stmt (stmt);
10834 stmt = begin_while_stmt ();
10835 tmp = RECUR (WHILE_COND (t));
10836 finish_while_stmt_cond (tmp, stmt);
10837 RECUR (WHILE_BODY (t));
10838 finish_while_stmt (stmt);
10842 stmt = begin_do_stmt ();
10843 RECUR (DO_BODY (t));
10844 finish_do_body (stmt);
10845 tmp = RECUR (DO_COND (t));
10846 finish_do_stmt (tmp, stmt);
10850 stmt = begin_if_stmt ();
10851 tmp = RECUR (IF_COND (t));
10852 finish_if_stmt_cond (tmp, stmt);
10853 RECUR (THEN_CLAUSE (t));
10854 finish_then_clause (stmt);
10856 if (ELSE_CLAUSE (t))
10858 begin_else_clause (stmt);
10859 RECUR (ELSE_CLAUSE (t));
10860 finish_else_clause (stmt);
10863 finish_if_stmt (stmt);
10867 if (BIND_EXPR_BODY_BLOCK (t))
10868 stmt = begin_function_body ();
10870 stmt = begin_compound_stmt (BIND_EXPR_TRY_BLOCK (t)
10871 ? BCS_TRY_BLOCK : 0);
10873 RECUR (BIND_EXPR_BODY (t));
10875 if (BIND_EXPR_BODY_BLOCK (t))
10876 finish_function_body (stmt);
10878 finish_compound_stmt (stmt);
10882 finish_break_stmt ();
10885 case CONTINUE_STMT:
10886 finish_continue_stmt ();
10890 stmt = begin_switch_stmt ();
10891 tmp = RECUR (SWITCH_STMT_COND (t));
10892 finish_switch_cond (tmp, stmt);
10893 RECUR (SWITCH_STMT_BODY (t));
10894 finish_switch_stmt (stmt);
10897 case CASE_LABEL_EXPR:
10898 finish_case_label (EXPR_LOCATION (t),
10899 RECUR (CASE_LOW (t)),
10900 RECUR (CASE_HIGH (t)));
10905 tree decl = LABEL_EXPR_LABEL (t);
10908 label = finish_label_stmt (DECL_NAME (decl));
10909 if (DECL_ATTRIBUTES (decl) != NULL_TREE)
10910 cplus_decl_attributes (&label, DECL_ATTRIBUTES (decl), 0);
10915 tmp = GOTO_DESTINATION (t);
10916 if (TREE_CODE (tmp) != LABEL_DECL)
10917 /* Computed goto's must be tsubst'd into. On the other hand,
10918 non-computed gotos must not be; the identifier in question
10919 will have no binding. */
10922 tmp = DECL_NAME (tmp);
10923 finish_goto_stmt (tmp);
10927 tmp = finish_asm_stmt
10928 (ASM_VOLATILE_P (t),
10929 RECUR (ASM_STRING (t)),
10930 tsubst_copy_asm_operands (ASM_OUTPUTS (t), args, complain, in_decl),
10931 tsubst_copy_asm_operands (ASM_INPUTS (t), args, complain, in_decl),
10932 tsubst_copy_asm_operands (ASM_CLOBBERS (t), args, complain, in_decl));
10934 tree asm_expr = tmp;
10935 if (TREE_CODE (asm_expr) == CLEANUP_POINT_EXPR)
10936 asm_expr = TREE_OPERAND (asm_expr, 0);
10937 ASM_INPUT_P (asm_expr) = ASM_INPUT_P (t);
10944 stmt = begin_try_block ();
10945 RECUR (TRY_STMTS (t));
10946 finish_cleanup_try_block (stmt);
10947 finish_cleanup (RECUR (TRY_HANDLERS (t)), stmt);
10951 tree compound_stmt = NULL_TREE;
10953 if (FN_TRY_BLOCK_P (t))
10954 stmt = begin_function_try_block (&compound_stmt);
10956 stmt = begin_try_block ();
10958 RECUR (TRY_STMTS (t));
10960 if (FN_TRY_BLOCK_P (t))
10961 finish_function_try_block (stmt);
10963 finish_try_block (stmt);
10965 RECUR (TRY_HANDLERS (t));
10966 if (FN_TRY_BLOCK_P (t))
10967 finish_function_handler_sequence (stmt, compound_stmt);
10969 finish_handler_sequence (stmt);
10975 tree decl = HANDLER_PARMS (t);
10979 decl = tsubst (decl, args, complain, in_decl);
10980 /* Prevent instantiate_decl from trying to instantiate
10981 this variable. We've already done all that needs to be
10983 if (decl != error_mark_node)
10984 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
10986 stmt = begin_handler ();
10987 finish_handler_parms (decl, stmt);
10988 RECUR (HANDLER_BODY (t));
10989 finish_handler (stmt);
10994 tsubst (TREE_TYPE (t), args, complain, NULL_TREE);
10997 case STATIC_ASSERT:
11000 tsubst_expr (STATIC_ASSERT_CONDITION (t),
11003 /*integral_constant_expression_p=*/true);
11004 finish_static_assert (condition,
11005 STATIC_ASSERT_MESSAGE (t),
11006 STATIC_ASSERT_SOURCE_LOCATION (t),
11007 /*member_p=*/false);
11012 tmp = tsubst_omp_clauses (OMP_PARALLEL_CLAUSES (t),
11013 args, complain, in_decl);
11014 stmt = begin_omp_parallel ();
11015 RECUR (OMP_PARALLEL_BODY (t));
11016 OMP_PARALLEL_COMBINED (finish_omp_parallel (tmp, stmt))
11017 = OMP_PARALLEL_COMBINED (t);
11021 tmp = tsubst_omp_clauses (OMP_TASK_CLAUSES (t),
11022 args, complain, in_decl);
11023 stmt = begin_omp_task ();
11024 RECUR (OMP_TASK_BODY (t));
11025 finish_omp_task (tmp, stmt);
11030 tree clauses, body, pre_body;
11031 tree declv, initv, condv, incrv;
11034 clauses = tsubst_omp_clauses (OMP_FOR_CLAUSES (t),
11035 args, complain, in_decl);
11036 declv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
11037 initv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
11038 condv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
11039 incrv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
11041 for (i = 0; i < TREE_VEC_LENGTH (OMP_FOR_INIT (t)); i++)
11042 tsubst_omp_for_iterator (t, i, declv, initv, condv, incrv,
11043 &clauses, args, complain, in_decl,
11044 integral_constant_expression_p);
11046 stmt = begin_omp_structured_block ();
11048 for (i = 0; i < TREE_VEC_LENGTH (initv); i++)
11049 if (TREE_VEC_ELT (initv, i) == NULL
11050 || TREE_CODE (TREE_VEC_ELT (initv, i)) != DECL_EXPR)
11051 TREE_VEC_ELT (initv, i) = RECUR (TREE_VEC_ELT (initv, i));
11052 else if (CLASS_TYPE_P (TREE_TYPE (TREE_VEC_ELT (initv, i))))
11054 tree init = RECUR (TREE_VEC_ELT (initv, i));
11055 gcc_assert (init == TREE_VEC_ELT (declv, i));
11056 TREE_VEC_ELT (initv, i) = NULL_TREE;
11060 tree decl_expr = TREE_VEC_ELT (initv, i);
11061 tree init = DECL_INITIAL (DECL_EXPR_DECL (decl_expr));
11062 gcc_assert (init != NULL);
11063 TREE_VEC_ELT (initv, i) = RECUR (init);
11064 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = NULL;
11066 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = init;
11069 pre_body = push_stmt_list ();
11070 RECUR (OMP_FOR_PRE_BODY (t));
11071 pre_body = pop_stmt_list (pre_body);
11073 body = push_stmt_list ();
11074 RECUR (OMP_FOR_BODY (t));
11075 body = pop_stmt_list (body);
11077 t = finish_omp_for (EXPR_LOCATION (t), declv, initv, condv, incrv,
11078 body, pre_body, clauses);
11080 add_stmt (finish_omp_structured_block (stmt));
11086 tmp = tsubst_omp_clauses (OMP_CLAUSES (t), args, complain, in_decl);
11087 stmt = push_stmt_list ();
11088 RECUR (OMP_BODY (t));
11089 stmt = pop_stmt_list (stmt);
11092 OMP_BODY (t) = stmt;
11093 OMP_CLAUSES (t) = tmp;
11101 stmt = push_stmt_list ();
11102 RECUR (OMP_BODY (t));
11103 stmt = pop_stmt_list (stmt);
11106 OMP_BODY (t) = stmt;
11111 gcc_assert (OMP_ATOMIC_DEPENDENT_P (t));
11113 tree op1 = TREE_OPERAND (t, 1);
11114 tree lhs = RECUR (TREE_OPERAND (op1, 0));
11115 tree rhs = RECUR (TREE_OPERAND (op1, 1));
11116 finish_omp_atomic (TREE_CODE (op1), lhs, rhs);
11120 case EXPR_PACK_EXPANSION:
11121 error ("invalid use of pack expansion expression");
11122 return error_mark_node;
11124 case NONTYPE_ARGUMENT_PACK:
11125 error ("use %<...%> to expand argument pack");
11126 return error_mark_node;
11129 gcc_assert (!STATEMENT_CODE_P (TREE_CODE (t)));
11131 return tsubst_copy_and_build (t, args, complain, in_decl,
11132 /*function_p=*/false,
11133 integral_constant_expression_p);
11140 /* T is a postfix-expression that is not being used in a function
11141 call. Return the substituted version of T. */
11144 tsubst_non_call_postfix_expression (tree t, tree args,
11145 tsubst_flags_t complain,
11148 if (TREE_CODE (t) == SCOPE_REF)
11149 t = tsubst_qualified_id (t, args, complain, in_decl,
11150 /*done=*/false, /*address_p=*/false);
11152 t = tsubst_copy_and_build (t, args, complain, in_decl,
11153 /*function_p=*/false,
11154 /*integral_constant_expression_p=*/false);
11159 /* Like tsubst but deals with expressions and performs semantic
11160 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
11163 tsubst_copy_and_build (tree t,
11165 tsubst_flags_t complain,
11168 bool integral_constant_expression_p)
11170 #define RECUR(NODE) \
11171 tsubst_copy_and_build (NODE, args, complain, in_decl, \
11172 /*function_p=*/false, \
11173 integral_constant_expression_p)
11177 if (t == NULL_TREE || t == error_mark_node)
11180 switch (TREE_CODE (t))
11184 /* Fall through. */
11185 case IDENTIFIER_NODE:
11189 bool non_integral_constant_expression_p;
11190 const char *error_msg;
11192 if (IDENTIFIER_TYPENAME_P (t))
11194 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
11195 t = mangle_conv_op_name_for_type (new_type);
11198 /* Look up the name. */
11199 decl = lookup_name (t);
11201 /* By convention, expressions use ERROR_MARK_NODE to indicate
11202 failure, not NULL_TREE. */
11203 if (decl == NULL_TREE)
11204 decl = error_mark_node;
11206 decl = finish_id_expression (t, decl, NULL_TREE,
11208 integral_constant_expression_p,
11209 /*allow_non_integral_constant_expression_p=*/false,
11210 &non_integral_constant_expression_p,
11211 /*template_p=*/false,
11213 /*address_p=*/false,
11214 /*template_arg_p=*/false,
11219 if (!function_p && TREE_CODE (decl) == IDENTIFIER_NODE)
11220 decl = unqualified_name_lookup_error (decl);
11224 case TEMPLATE_ID_EXPR:
11227 tree templ = RECUR (TREE_OPERAND (t, 0));
11228 tree targs = TREE_OPERAND (t, 1);
11231 targs = tsubst_template_args (targs, args, complain, in_decl);
11233 if (TREE_CODE (templ) == COMPONENT_REF)
11235 object = TREE_OPERAND (templ, 0);
11236 templ = TREE_OPERAND (templ, 1);
11239 object = NULL_TREE;
11240 templ = lookup_template_function (templ, targs);
11243 return build3 (COMPONENT_REF, TREE_TYPE (templ),
11244 object, templ, NULL_TREE);
11246 return baselink_for_fns (templ);
11251 tree r = RECUR (TREE_OPERAND (t, 0));
11253 if (REFERENCE_REF_P (t))
11255 /* A type conversion to reference type will be enclosed in
11256 such an indirect ref, but the substitution of the cast
11257 will have also added such an indirect ref. */
11258 if (TREE_CODE (TREE_TYPE (r)) == REFERENCE_TYPE)
11259 r = convert_from_reference (r);
11262 r = build_x_indirect_ref (r, "unary *", complain);
11268 (tsubst (TREE_TYPE (t), args, complain, in_decl),
11269 RECUR (TREE_OPERAND (t, 0)));
11272 case REINTERPRET_CAST_EXPR:
11273 case CONST_CAST_EXPR:
11274 case DYNAMIC_CAST_EXPR:
11275 case STATIC_CAST_EXPR:
11280 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
11281 if (integral_constant_expression_p
11282 && !cast_valid_in_integral_constant_expression_p (type))
11284 if (complain & tf_error)
11285 error ("a cast to a type other than an integral or "
11286 "enumeration type cannot appear in a constant-expression");
11287 return error_mark_node;
11290 op = RECUR (TREE_OPERAND (t, 0));
11292 switch (TREE_CODE (t))
11295 return build_functional_cast (type, op, complain);
11296 case REINTERPRET_CAST_EXPR:
11297 return build_reinterpret_cast (type, op, complain);
11298 case CONST_CAST_EXPR:
11299 return build_const_cast (type, op, complain);
11300 case DYNAMIC_CAST_EXPR:
11301 return build_dynamic_cast (type, op, complain);
11302 case STATIC_CAST_EXPR:
11303 return build_static_cast (type, op, complain);
11305 gcc_unreachable ();
11309 case POSTDECREMENT_EXPR:
11310 case POSTINCREMENT_EXPR:
11311 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
11312 args, complain, in_decl);
11313 return build_x_unary_op (TREE_CODE (t), op1, complain);
11315 case PREDECREMENT_EXPR:
11316 case PREINCREMENT_EXPR:
11320 case TRUTH_NOT_EXPR:
11321 case UNARY_PLUS_EXPR: /* Unary + */
11322 case REALPART_EXPR:
11323 case IMAGPART_EXPR:
11324 return build_x_unary_op (TREE_CODE (t), RECUR (TREE_OPERAND (t, 0)),
11328 op1 = TREE_OPERAND (t, 0);
11329 if (TREE_CODE (op1) == SCOPE_REF)
11330 op1 = tsubst_qualified_id (op1, args, complain, in_decl,
11331 /*done=*/true, /*address_p=*/true);
11333 op1 = tsubst_non_call_postfix_expression (op1, args, complain,
11335 if (TREE_CODE (op1) == LABEL_DECL)
11336 return finish_label_address_expr (DECL_NAME (op1),
11337 EXPR_LOCATION (op1));
11338 return build_x_unary_op (ADDR_EXPR, op1, complain);
11343 case TRUNC_DIV_EXPR:
11344 case CEIL_DIV_EXPR:
11345 case FLOOR_DIV_EXPR:
11346 case ROUND_DIV_EXPR:
11347 case EXACT_DIV_EXPR:
11351 case TRUNC_MOD_EXPR:
11352 case FLOOR_MOD_EXPR:
11353 case TRUTH_ANDIF_EXPR:
11354 case TRUTH_ORIF_EXPR:
11355 case TRUTH_AND_EXPR:
11356 case TRUTH_OR_EXPR:
11371 return build_x_binary_op
11373 RECUR (TREE_OPERAND (t, 0)),
11374 (TREE_NO_WARNING (TREE_OPERAND (t, 0))
11376 : TREE_CODE (TREE_OPERAND (t, 0))),
11377 RECUR (TREE_OPERAND (t, 1)),
11378 (TREE_NO_WARNING (TREE_OPERAND (t, 1))
11380 : TREE_CODE (TREE_OPERAND (t, 1))),
11381 /*overloaded_p=*/NULL,
11385 return tsubst_qualified_id (t, args, complain, in_decl, /*done=*/true,
11386 /*address_p=*/false);
11388 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
11389 args, complain, in_decl);
11390 return build_x_array_ref (op1, RECUR (TREE_OPERAND (t, 1)), complain);
11393 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
11394 return tsubst_copy (t, args, complain, in_decl);
11398 op1 = TREE_OPERAND (t, 0);
11401 /* When there are no ARGS, we are trying to evaluate a
11402 non-dependent expression from the parser. Trying to do
11403 the substitutions may not work. */
11405 op1 = TREE_TYPE (op1);
11409 ++cp_unevaluated_operand;
11410 ++c_inhibit_evaluation_warnings;
11411 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
11412 /*function_p=*/false,
11413 /*integral_constant_expression_p=*/false);
11414 --cp_unevaluated_operand;
11415 --c_inhibit_evaluation_warnings;
11418 return cxx_sizeof_or_alignof_type (op1, TREE_CODE (t),
11419 complain & tf_error);
11421 return cxx_sizeof_or_alignof_expr (op1, TREE_CODE (t),
11422 complain & tf_error);
11426 tree r = build_x_modify_expr
11427 (RECUR (TREE_OPERAND (t, 0)),
11428 TREE_CODE (TREE_OPERAND (t, 1)),
11429 RECUR (TREE_OPERAND (t, 2)),
11431 /* TREE_NO_WARNING must be set if either the expression was
11432 parenthesized or it uses an operator such as >>= rather
11433 than plain assignment. In the former case, it was already
11434 set and must be copied. In the latter case,
11435 build_x_modify_expr sets it and it must not be reset
11437 if (TREE_NO_WARNING (t))
11438 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
11443 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
11444 args, complain, in_decl);
11445 /* Remember that there was a reference to this entity. */
11448 return build_x_arrow (op1);
11452 tree placement = RECUR (TREE_OPERAND (t, 0));
11453 tree init = RECUR (TREE_OPERAND (t, 3));
11454 VEC(tree,gc) *placement_vec;
11455 VEC(tree,gc) *init_vec;
11458 if (placement == NULL_TREE)
11459 placement_vec = NULL;
11462 placement_vec = make_tree_vector ();
11463 for (; placement != NULL_TREE; placement = TREE_CHAIN (placement))
11464 VEC_safe_push (tree, gc, placement_vec, TREE_VALUE (placement));
11467 /* If there was an initializer in the original tree, but it
11468 instantiated to an empty list, then we should pass a
11469 non-NULL empty vector to tell build_new that it was an
11470 empty initializer() rather than no initializer. This can
11471 only happen when the initializer is a pack expansion whose
11472 parameter packs are of length zero. */
11473 if (init == NULL_TREE && TREE_OPERAND (t, 3) == NULL_TREE)
11477 init_vec = make_tree_vector ();
11478 if (init == void_zero_node)
11479 gcc_assert (init_vec != NULL);
11482 for (; init != NULL_TREE; init = TREE_CHAIN (init))
11483 VEC_safe_push (tree, gc, init_vec, TREE_VALUE (init));
11487 ret = build_new (&placement_vec,
11488 RECUR (TREE_OPERAND (t, 1)),
11489 RECUR (TREE_OPERAND (t, 2)),
11491 NEW_EXPR_USE_GLOBAL (t),
11494 if (placement_vec != NULL)
11495 release_tree_vector (placement_vec);
11496 if (init_vec != NULL)
11497 release_tree_vector (init_vec);
11503 return delete_sanity
11504 (RECUR (TREE_OPERAND (t, 0)),
11505 RECUR (TREE_OPERAND (t, 1)),
11506 DELETE_EXPR_USE_VEC (t),
11507 DELETE_EXPR_USE_GLOBAL (t));
11509 case COMPOUND_EXPR:
11510 return build_x_compound_expr (RECUR (TREE_OPERAND (t, 0)),
11511 RECUR (TREE_OPERAND (t, 1)),
11517 VEC(tree,gc) *call_args;
11518 unsigned int nargs, i;
11523 function = CALL_EXPR_FN (t);
11524 /* When we parsed the expression, we determined whether or
11525 not Koenig lookup should be performed. */
11526 koenig_p = KOENIG_LOOKUP_P (t);
11527 if (TREE_CODE (function) == SCOPE_REF)
11529 qualified_p = true;
11530 function = tsubst_qualified_id (function, args, complain, in_decl,
11532 /*address_p=*/false);
11536 if (TREE_CODE (function) == COMPONENT_REF)
11538 tree op = TREE_OPERAND (function, 1);
11540 qualified_p = (TREE_CODE (op) == SCOPE_REF
11541 || (BASELINK_P (op)
11542 && BASELINK_QUALIFIED_P (op)));
11545 qualified_p = false;
11547 function = tsubst_copy_and_build (function, args, complain,
11550 integral_constant_expression_p);
11552 if (BASELINK_P (function))
11553 qualified_p = true;
11556 nargs = call_expr_nargs (t);
11557 call_args = make_tree_vector ();
11558 for (i = 0; i < nargs; ++i)
11560 tree arg = CALL_EXPR_ARG (t, i);
11562 if (!PACK_EXPANSION_P (arg))
11563 VEC_safe_push (tree, gc, call_args,
11564 RECUR (CALL_EXPR_ARG (t, i)));
11567 /* Expand the pack expansion and push each entry onto
11569 arg = tsubst_pack_expansion (arg, args, complain, in_decl);
11570 if (TREE_CODE (arg) == TREE_VEC)
11572 unsigned int len, j;
11574 len = TREE_VEC_LENGTH (arg);
11575 for (j = 0; j < len; ++j)
11577 tree value = TREE_VEC_ELT (arg, j);
11578 if (value != NULL_TREE)
11579 value = convert_from_reference (value);
11580 VEC_safe_push (tree, gc, call_args, value);
11585 /* A partial substitution. Add one entry. */
11586 VEC_safe_push (tree, gc, call_args, arg);
11591 /* We do not perform argument-dependent lookup if normal
11592 lookup finds a non-function, in accordance with the
11593 expected resolution of DR 218. */
11595 && ((is_overloaded_fn (function)
11596 /* If lookup found a member function, the Koenig lookup is
11597 not appropriate, even if an unqualified-name was used
11598 to denote the function. */
11599 && !DECL_FUNCTION_MEMBER_P (get_first_fn (function)))
11600 || TREE_CODE (function) == IDENTIFIER_NODE)
11601 /* Only do this when substitution turns a dependent call
11602 into a non-dependent call. */
11603 && type_dependent_expression_p_push (t)
11604 && !any_type_dependent_arguments_p (call_args))
11605 function = perform_koenig_lookup (function, call_args);
11607 if (TREE_CODE (function) == IDENTIFIER_NODE)
11609 unqualified_name_lookup_error (function);
11610 release_tree_vector (call_args);
11611 return error_mark_node;
11614 /* Remember that there was a reference to this entity. */
11615 if (DECL_P (function))
11616 mark_used (function);
11618 if (TREE_CODE (function) == OFFSET_REF)
11619 ret = build_offset_ref_call_from_tree (function, &call_args);
11620 else if (TREE_CODE (function) == COMPONENT_REF)
11622 if (!BASELINK_P (TREE_OPERAND (function, 1)))
11623 ret = finish_call_expr (function, &call_args,
11624 /*disallow_virtual=*/false,
11625 /*koenig_p=*/false,
11628 ret = (build_new_method_call
11629 (TREE_OPERAND (function, 0),
11630 TREE_OPERAND (function, 1),
11631 &call_args, NULL_TREE,
11632 qualified_p ? LOOKUP_NONVIRTUAL : LOOKUP_NORMAL,
11637 ret = finish_call_expr (function, &call_args,
11638 /*disallow_virtual=*/qualified_p,
11642 release_tree_vector (call_args);
11648 return build_x_conditional_expr
11649 (RECUR (TREE_OPERAND (t, 0)),
11650 RECUR (TREE_OPERAND (t, 1)),
11651 RECUR (TREE_OPERAND (t, 2)),
11654 case PSEUDO_DTOR_EXPR:
11655 return finish_pseudo_destructor_expr
11656 (RECUR (TREE_OPERAND (t, 0)),
11657 RECUR (TREE_OPERAND (t, 1)),
11658 RECUR (TREE_OPERAND (t, 2)));
11662 tree purpose, value, chain;
11664 if (t == void_list_node)
11667 if ((TREE_PURPOSE (t) && PACK_EXPANSION_P (TREE_PURPOSE (t)))
11668 || (TREE_VALUE (t) && PACK_EXPANSION_P (TREE_VALUE (t))))
11670 /* We have pack expansions, so expand those and
11671 create a new list out of it. */
11672 tree purposevec = NULL_TREE;
11673 tree valuevec = NULL_TREE;
11677 /* Expand the argument expressions. */
11678 if (TREE_PURPOSE (t))
11679 purposevec = tsubst_pack_expansion (TREE_PURPOSE (t), args,
11680 complain, in_decl);
11681 if (TREE_VALUE (t))
11682 valuevec = tsubst_pack_expansion (TREE_VALUE (t), args,
11683 complain, in_decl);
11685 /* Build the rest of the list. */
11686 chain = TREE_CHAIN (t);
11687 if (chain && chain != void_type_node)
11688 chain = RECUR (chain);
11690 /* Determine the number of arguments. */
11691 if (purposevec && TREE_CODE (purposevec) == TREE_VEC)
11693 len = TREE_VEC_LENGTH (purposevec);
11694 gcc_assert (!valuevec || len == TREE_VEC_LENGTH (valuevec));
11696 else if (TREE_CODE (valuevec) == TREE_VEC)
11697 len = TREE_VEC_LENGTH (valuevec);
11700 /* Since we only performed a partial substitution into
11701 the argument pack, we only return a single list
11703 if (purposevec == TREE_PURPOSE (t)
11704 && valuevec == TREE_VALUE (t)
11705 && chain == TREE_CHAIN (t))
11708 return tree_cons (purposevec, valuevec, chain);
11711 /* Convert the argument vectors into a TREE_LIST */
11715 /* Grab the Ith values. */
11717 purpose = purposevec ? TREE_VEC_ELT (purposevec, i)
11720 = valuevec ? convert_from_reference (TREE_VEC_ELT (valuevec, i))
11723 /* Build the list (backwards). */
11724 chain = tree_cons (purpose, value, chain);
11730 purpose = TREE_PURPOSE (t);
11732 purpose = RECUR (purpose);
11733 value = TREE_VALUE (t);
11735 value = RECUR (value);
11736 chain = TREE_CHAIN (t);
11737 if (chain && chain != void_type_node)
11738 chain = RECUR (chain);
11739 if (purpose == TREE_PURPOSE (t)
11740 && value == TREE_VALUE (t)
11741 && chain == TREE_CHAIN (t))
11743 return tree_cons (purpose, value, chain);
11746 case COMPONENT_REF:
11752 object = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
11753 args, complain, in_decl);
11754 /* Remember that there was a reference to this entity. */
11755 if (DECL_P (object))
11756 mark_used (object);
11757 object_type = TREE_TYPE (object);
11759 member = TREE_OPERAND (t, 1);
11760 if (BASELINK_P (member))
11761 member = tsubst_baselink (member,
11762 non_reference (TREE_TYPE (object)),
11763 args, complain, in_decl);
11765 member = tsubst_copy (member, args, complain, in_decl);
11766 if (member == error_mark_node)
11767 return error_mark_node;
11769 if (object_type && !CLASS_TYPE_P (object_type))
11771 if (SCALAR_TYPE_P (object_type))
11773 tree s = NULL_TREE;
11774 tree dtor = member;
11776 if (TREE_CODE (dtor) == SCOPE_REF)
11778 s = TREE_OPERAND (dtor, 0);
11779 dtor = TREE_OPERAND (dtor, 1);
11781 if (TREE_CODE (dtor) == BIT_NOT_EXPR)
11783 dtor = TREE_OPERAND (dtor, 0);
11785 return finish_pseudo_destructor_expr (object, s, dtor);
11789 else if (TREE_CODE (member) == SCOPE_REF
11790 && TREE_CODE (TREE_OPERAND (member, 1)) == TEMPLATE_ID_EXPR)
11795 /* Lookup the template functions now that we know what the
11797 tmpl = TREE_OPERAND (TREE_OPERAND (member, 1), 0);
11798 args = TREE_OPERAND (TREE_OPERAND (member, 1), 1);
11799 member = lookup_qualified_name (TREE_OPERAND (member, 0), tmpl,
11800 /*is_type_p=*/false,
11801 /*complain=*/false);
11802 if (BASELINK_P (member))
11804 BASELINK_FUNCTIONS (member)
11805 = build_nt (TEMPLATE_ID_EXPR, BASELINK_FUNCTIONS (member),
11807 member = (adjust_result_of_qualified_name_lookup
11808 (member, BINFO_TYPE (BASELINK_BINFO (member)),
11813 qualified_name_lookup_error (object_type, tmpl, member,
11815 return error_mark_node;
11818 else if (TREE_CODE (member) == SCOPE_REF
11819 && !CLASS_TYPE_P (TREE_OPERAND (member, 0))
11820 && TREE_CODE (TREE_OPERAND (member, 0)) != NAMESPACE_DECL)
11822 if (complain & tf_error)
11824 if (TYPE_P (TREE_OPERAND (member, 0)))
11825 error ("%qT is not a class or namespace",
11826 TREE_OPERAND (member, 0));
11828 error ("%qD is not a class or namespace",
11829 TREE_OPERAND (member, 0));
11831 return error_mark_node;
11833 else if (TREE_CODE (member) == FIELD_DECL)
11834 return finish_non_static_data_member (member, object, NULL_TREE);
11836 return finish_class_member_access_expr (object, member,
11837 /*template_p=*/false,
11843 (RECUR (TREE_OPERAND (t, 0)));
11847 VEC(constructor_elt,gc) *n;
11848 constructor_elt *ce;
11849 unsigned HOST_WIDE_INT idx;
11850 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
11851 bool process_index_p;
11853 bool need_copy_p = false;
11856 if (type == error_mark_node)
11857 return error_mark_node;
11859 /* digest_init will do the wrong thing if we let it. */
11860 if (type && TYPE_PTRMEMFUNC_P (type))
11863 /* We do not want to process the index of aggregate
11864 initializers as they are identifier nodes which will be
11865 looked up by digest_init. */
11866 process_index_p = !(type && MAYBE_CLASS_TYPE_P (type));
11868 n = VEC_copy (constructor_elt, gc, CONSTRUCTOR_ELTS (t));
11869 newlen = VEC_length (constructor_elt, n);
11870 for (idx = 0; VEC_iterate (constructor_elt, n, idx, ce); idx++)
11872 if (ce->index && process_index_p)
11873 ce->index = RECUR (ce->index);
11875 if (PACK_EXPANSION_P (ce->value))
11877 /* Substitute into the pack expansion. */
11878 ce->value = tsubst_pack_expansion (ce->value, args, complain,
11881 if (ce->value == error_mark_node)
11883 else if (TREE_VEC_LENGTH (ce->value) == 1)
11884 /* Just move the argument into place. */
11885 ce->value = TREE_VEC_ELT (ce->value, 0);
11888 /* Update the length of the final CONSTRUCTOR
11889 arguments vector, and note that we will need to
11891 newlen = newlen + TREE_VEC_LENGTH (ce->value) - 1;
11892 need_copy_p = true;
11896 ce->value = RECUR (ce->value);
11901 VEC(constructor_elt,gc) *old_n = n;
11903 n = VEC_alloc (constructor_elt, gc, newlen);
11904 for (idx = 0; VEC_iterate (constructor_elt, old_n, idx, ce);
11907 if (TREE_CODE (ce->value) == TREE_VEC)
11909 int i, len = TREE_VEC_LENGTH (ce->value);
11910 for (i = 0; i < len; ++i)
11911 CONSTRUCTOR_APPEND_ELT (n, 0,
11912 TREE_VEC_ELT (ce->value, i));
11915 CONSTRUCTOR_APPEND_ELT (n, 0, ce->value);
11919 r = build_constructor (init_list_type_node, n);
11920 CONSTRUCTOR_IS_DIRECT_INIT (r) = CONSTRUCTOR_IS_DIRECT_INIT (t);
11922 if (TREE_HAS_CONSTRUCTOR (t))
11923 return finish_compound_literal (type, r);
11930 tree operand_0 = RECUR (TREE_OPERAND (t, 0));
11931 if (TYPE_P (operand_0))
11932 return get_typeid (operand_0);
11933 return build_typeid (operand_0);
11943 tree r = tsubst_copy (t, args, complain, in_decl);
11945 if (TREE_CODE (TREE_TYPE (t)) != REFERENCE_TYPE)
11946 /* If the original type was a reference, we'll be wrapped in
11947 the appropriate INDIRECT_REF. */
11948 r = convert_from_reference (r);
11953 return build_x_va_arg (RECUR (TREE_OPERAND (t, 0)),
11954 tsubst_copy (TREE_TYPE (t), args, complain,
11957 case OFFSETOF_EXPR:
11958 return finish_offsetof (RECUR (TREE_OPERAND (t, 0)));
11962 tree type1 = tsubst_copy (TRAIT_EXPR_TYPE1 (t), args,
11963 complain, in_decl);
11965 tree type2 = TRAIT_EXPR_TYPE2 (t);
11967 type2 = tsubst_copy (type2, args, complain, in_decl);
11969 return finish_trait_expr (TRAIT_EXPR_KIND (t), type1, type2);
11974 tree old_stmt_expr = cur_stmt_expr;
11975 tree stmt_expr = begin_stmt_expr ();
11977 cur_stmt_expr = stmt_expr;
11978 tsubst_expr (STMT_EXPR_STMT (t), args, complain, in_decl,
11979 integral_constant_expression_p);
11980 stmt_expr = finish_stmt_expr (stmt_expr, false);
11981 cur_stmt_expr = old_stmt_expr;
11987 t = tsubst_copy (t, args, complain, in_decl);
11988 /* As in finish_id_expression, we resolve enumeration constants
11989 to their underlying values. */
11990 if (TREE_CODE (t) == CONST_DECL)
11992 used_types_insert (TREE_TYPE (t));
11993 return DECL_INITIAL (t);
11998 /* Handle Objective-C++ constructs, if appropriate. */
12001 = objcp_tsubst_copy_and_build (t, args, complain,
12002 in_decl, /*function_p=*/false);
12006 return tsubst_copy (t, args, complain, in_decl);
12012 /* Verify that the instantiated ARGS are valid. For type arguments,
12013 make sure that the type's linkage is ok. For non-type arguments,
12014 make sure they are constants if they are integral or enumerations.
12015 Emit an error under control of COMPLAIN, and return TRUE on error. */
12018 check_instantiated_arg (tree tmpl, tree t, tsubst_flags_t complain)
12020 if (ARGUMENT_PACK_P (t))
12022 tree vec = ARGUMENT_PACK_ARGS (t);
12023 int len = TREE_VEC_LENGTH (vec);
12024 bool result = false;
12027 for (i = 0; i < len; ++i)
12028 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (vec, i), complain))
12032 else if (TYPE_P (t))
12034 /* [basic.link]: A name with no linkage (notably, the name
12035 of a class or enumeration declared in a local scope)
12036 shall not be used to declare an entity with linkage.
12037 This implies that names with no linkage cannot be used as
12038 template arguments. */
12039 tree nt = no_linkage_check (t, /*relaxed_p=*/false);
12043 /* DR 488 makes use of a type with no linkage cause
12044 type deduction to fail. */
12045 if (complain & tf_error)
12047 if (TYPE_ANONYMOUS_P (nt))
12048 error ("%qT is/uses anonymous type", t);
12050 error ("template argument for %qD uses local type %qT",
12055 /* In order to avoid all sorts of complications, we do not
12056 allow variably-modified types as template arguments. */
12057 else if (variably_modified_type_p (t, NULL_TREE))
12059 if (complain & tf_error)
12060 error ("%qT is a variably modified type", t);
12064 /* A non-type argument of integral or enumerated type must be a
12066 else if (TREE_TYPE (t)
12067 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t))
12068 && !TREE_CONSTANT (t))
12070 if (complain & tf_error)
12071 error ("integral expression %qE is not constant", t);
12078 check_instantiated_args (tree tmpl, tree args, tsubst_flags_t complain)
12080 int ix, len = DECL_NTPARMS (tmpl);
12081 bool result = false;
12083 for (ix = 0; ix != len; ix++)
12085 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (args, ix), complain))
12088 if (result && (complain & tf_error))
12089 error (" trying to instantiate %qD", tmpl);
12093 /* Instantiate the indicated variable or function template TMPL with
12094 the template arguments in TARG_PTR. */
12097 instantiate_template (tree tmpl, tree targ_ptr, tsubst_flags_t complain)
12102 HOST_WIDE_INT saved_processing_template_decl;
12104 if (tmpl == error_mark_node)
12105 return error_mark_node;
12107 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
12109 /* If this function is a clone, handle it specially. */
12110 if (DECL_CLONED_FUNCTION_P (tmpl))
12115 spec = instantiate_template (DECL_CLONED_FUNCTION (tmpl), targ_ptr,
12117 if (spec == error_mark_node)
12118 return error_mark_node;
12120 /* Look for the clone. */
12121 FOR_EACH_CLONE (clone, spec)
12122 if (DECL_NAME (clone) == DECL_NAME (tmpl))
12124 /* We should always have found the clone by now. */
12125 gcc_unreachable ();
12129 /* Check to see if we already have this specialization. */
12130 spec = retrieve_specialization (tmpl, targ_ptr,
12131 /*class_specializations_p=*/false);
12132 if (spec != NULL_TREE)
12135 gen_tmpl = most_general_template (tmpl);
12136 if (tmpl != gen_tmpl)
12138 /* The TMPL is a partial instantiation. To get a full set of
12139 arguments we must add the arguments used to perform the
12140 partial instantiation. */
12141 targ_ptr = add_outermost_template_args (DECL_TI_ARGS (tmpl),
12144 /* Check to see if we already have this specialization. */
12145 spec = retrieve_specialization (gen_tmpl, targ_ptr,
12146 /*class_specializations_p=*/false);
12147 if (spec != NULL_TREE)
12151 if (check_instantiated_args (gen_tmpl, INNERMOST_TEMPLATE_ARGS (targ_ptr),
12153 return error_mark_node;
12155 /* We are building a FUNCTION_DECL, during which the access of its
12156 parameters and return types have to be checked. However this
12157 FUNCTION_DECL which is the desired context for access checking
12158 is not built yet. We solve this chicken-and-egg problem by
12159 deferring all checks until we have the FUNCTION_DECL. */
12160 push_deferring_access_checks (dk_deferred);
12162 /* Although PROCESSING_TEMPLATE_DECL may be true at this point
12163 (because, for example, we have encountered a non-dependent
12164 function call in the body of a template function and must now
12165 determine which of several overloaded functions will be called),
12166 within the instantiation itself we are not processing a
12168 saved_processing_template_decl = processing_template_decl;
12169 processing_template_decl = 0;
12170 /* Substitute template parameters to obtain the specialization. */
12171 fndecl = tsubst (DECL_TEMPLATE_RESULT (gen_tmpl),
12172 targ_ptr, complain, gen_tmpl);
12173 processing_template_decl = saved_processing_template_decl;
12174 if (fndecl == error_mark_node)
12175 return error_mark_node;
12177 /* Now we know the specialization, compute access previously
12179 push_access_scope (fndecl);
12181 /* Some typedefs referenced from within the template code need to be access
12182 checked at template instantiation time, i.e now. These types were
12183 added to the template at parsing time. Let's get those and perfom
12184 the acces checks then. */
12185 perform_typedefs_access_check (DECL_TEMPLATE_RESULT (tmpl), targ_ptr);
12186 perform_deferred_access_checks ();
12187 pop_access_scope (fndecl);
12188 pop_deferring_access_checks ();
12190 /* The DECL_TI_TEMPLATE should always be the immediate parent
12191 template, not the most general template. */
12192 DECL_TI_TEMPLATE (fndecl) = tmpl;
12194 /* If we've just instantiated the main entry point for a function,
12195 instantiate all the alternate entry points as well. We do this
12196 by cloning the instantiation of the main entry point, not by
12197 instantiating the template clones. */
12198 if (TREE_CHAIN (gen_tmpl) && DECL_CLONED_FUNCTION_P (TREE_CHAIN (gen_tmpl)))
12199 clone_function_decl (fndecl, /*update_method_vec_p=*/0);
12204 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
12205 NARGS elements of the arguments that are being used when calling
12206 it. TARGS is a vector into which the deduced template arguments
12209 Return zero for success, 2 for an incomplete match that doesn't resolve
12210 all the types, and 1 for complete failure. An error message will be
12211 printed only for an incomplete match.
12213 If FN is a conversion operator, or we are trying to produce a specific
12214 specialization, RETURN_TYPE is the return type desired.
12216 The EXPLICIT_TARGS are explicit template arguments provided via a
12219 The parameter STRICT is one of:
12222 We are deducing arguments for a function call, as in
12223 [temp.deduct.call].
12226 We are deducing arguments for a conversion function, as in
12227 [temp.deduct.conv].
12230 We are deducing arguments when doing an explicit instantiation
12231 as in [temp.explicit], when determining an explicit specialization
12232 as in [temp.expl.spec], or when taking the address of a function
12233 template, as in [temp.deduct.funcaddr]. */
12236 fn_type_unification (tree fn,
12237 tree explicit_targs,
12240 unsigned int nargs,
12242 unification_kind_t strict,
12248 bool incomplete_argument_packs_p = false;
12250 gcc_assert (TREE_CODE (fn) == TEMPLATE_DECL);
12252 fntype = TREE_TYPE (fn);
12253 if (explicit_targs)
12257 The specified template arguments must match the template
12258 parameters in kind (i.e., type, nontype, template), and there
12259 must not be more arguments than there are parameters;
12260 otherwise type deduction fails.
12262 Nontype arguments must match the types of the corresponding
12263 nontype template parameters, or must be convertible to the
12264 types of the corresponding nontype parameters as specified in
12265 _temp.arg.nontype_, otherwise type deduction fails.
12267 All references in the function type of the function template
12268 to the corresponding template parameters are replaced by the
12269 specified template argument values. If a substitution in a
12270 template parameter or in the function type of the function
12271 template results in an invalid type, type deduction fails. */
12272 tree tparms = DECL_INNERMOST_TEMPLATE_PARMS (fn);
12273 int i, len = TREE_VEC_LENGTH (tparms);
12274 tree converted_args;
12275 bool incomplete = false;
12277 if (explicit_targs == error_mark_node)
12281 = (coerce_template_parms (tparms, explicit_targs, NULL_TREE, tf_none,
12282 /*require_all_args=*/false,
12283 /*use_default_args=*/false));
12284 if (converted_args == error_mark_node)
12287 /* Substitute the explicit args into the function type. This is
12288 necessary so that, for instance, explicitly declared function
12289 arguments can match null pointed constants. If we were given
12290 an incomplete set of explicit args, we must not do semantic
12291 processing during substitution as we could create partial
12293 for (i = 0; i < len; i++)
12295 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
12296 bool parameter_pack = false;
12298 /* Dig out the actual parm. */
12299 if (TREE_CODE (parm) == TYPE_DECL
12300 || TREE_CODE (parm) == TEMPLATE_DECL)
12302 parm = TREE_TYPE (parm);
12303 parameter_pack = TEMPLATE_TYPE_PARAMETER_PACK (parm);
12305 else if (TREE_CODE (parm) == PARM_DECL)
12307 parm = DECL_INITIAL (parm);
12308 parameter_pack = TEMPLATE_PARM_PARAMETER_PACK (parm);
12311 if (parameter_pack)
12315 template_parm_level_and_index (parm, &level, &idx);
12317 /* Mark the argument pack as "incomplete". We could
12318 still deduce more arguments during unification. */
12319 targ = TMPL_ARG (converted_args, level, idx);
12322 ARGUMENT_PACK_INCOMPLETE_P(targ) = 1;
12323 ARGUMENT_PACK_EXPLICIT_ARGS (targ)
12324 = ARGUMENT_PACK_ARGS (targ);
12327 /* We have some incomplete argument packs. */
12328 incomplete_argument_packs_p = true;
12332 if (incomplete_argument_packs_p)
12333 /* Any substitution is guaranteed to be incomplete if there
12334 are incomplete argument packs, because we can still deduce
12338 incomplete = NUM_TMPL_ARGS (explicit_targs) != NUM_TMPL_ARGS (targs);
12340 processing_template_decl += incomplete;
12341 fntype = tsubst (fntype, converted_args, tf_none, NULL_TREE);
12342 processing_template_decl -= incomplete;
12344 if (fntype == error_mark_node)
12347 /* Place the explicitly specified arguments in TARGS. */
12348 for (i = NUM_TMPL_ARGS (converted_args); i--;)
12349 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (converted_args, i);
12352 /* Never do unification on the 'this' parameter. */
12353 parms = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (fntype));
12359 parms = tree_cons (NULL_TREE, TREE_TYPE (fntype), parms);
12360 new_args = XALLOCAVEC (tree, nargs + 1);
12361 new_args[0] = return_type;
12362 memcpy (new_args + 1, args, nargs * sizeof (tree));
12367 /* We allow incomplete unification without an error message here
12368 because the standard doesn't seem to explicitly prohibit it. Our
12369 callers must be ready to deal with unification failures in any
12371 result = type_unification_real (DECL_INNERMOST_TEMPLATE_PARMS (fn),
12372 targs, parms, args, nargs, /*subr=*/0,
12375 if (result == 0 && incomplete_argument_packs_p)
12377 int i, len = NUM_TMPL_ARGS (targs);
12379 /* Clear the "incomplete" flags on all argument packs. */
12380 for (i = 0; i < len; i++)
12382 tree arg = TREE_VEC_ELT (targs, i);
12383 if (ARGUMENT_PACK_P (arg))
12385 ARGUMENT_PACK_INCOMPLETE_P (arg) = 0;
12386 ARGUMENT_PACK_EXPLICIT_ARGS (arg) = NULL_TREE;
12391 /* Now that we have bindings for all of the template arguments,
12392 ensure that the arguments deduced for the template template
12393 parameters have compatible template parameter lists. We cannot
12394 check this property before we have deduced all template
12395 arguments, because the template parameter types of a template
12396 template parameter might depend on prior template parameters
12397 deduced after the template template parameter. The following
12398 ill-formed example illustrates this issue:
12400 template<typename T, template<T> class C> void f(C<5>, T);
12402 template<int N> struct X {};
12405 f(X<5>(), 5l); // error: template argument deduction fails
12408 The template parameter list of 'C' depends on the template type
12409 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
12410 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
12411 time that we deduce 'C'. */
12413 && !template_template_parm_bindings_ok_p
12414 (DECL_INNERMOST_TEMPLATE_PARMS (fn), targs))
12418 /* All is well so far. Now, check:
12422 When all template arguments have been deduced, all uses of
12423 template parameters in nondeduced contexts are replaced with
12424 the corresponding deduced argument values. If the
12425 substitution results in an invalid type, as described above,
12426 type deduction fails. */
12428 tree substed = tsubst (TREE_TYPE (fn), targs, tf_none, NULL_TREE);
12429 if (substed == error_mark_node)
12432 /* If we're looking for an exact match, check that what we got
12433 is indeed an exact match. It might not be if some template
12434 parameters are used in non-deduced contexts. */
12435 if (strict == DEDUCE_EXACT)
12440 = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (substed));
12442 sarg = tree_cons (NULL_TREE, TREE_TYPE (substed), sarg);
12443 for (i = 0; i < nargs && sarg; ++i, sarg = TREE_CHAIN (sarg))
12444 if (!same_type_p (args[i], TREE_VALUE (sarg)))
12452 /* Adjust types before performing type deduction, as described in
12453 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
12454 sections are symmetric. PARM is the type of a function parameter
12455 or the return type of the conversion function. ARG is the type of
12456 the argument passed to the call, or the type of the value
12457 initialized with the result of the conversion function.
12458 ARG_EXPR is the original argument expression, which may be null. */
12461 maybe_adjust_types_for_deduction (unification_kind_t strict,
12475 /* Swap PARM and ARG throughout the remainder of this
12476 function; the handling is precisely symmetric since PARM
12477 will initialize ARG rather than vice versa. */
12485 /* There is nothing to do in this case. */
12489 gcc_unreachable ();
12492 if (TREE_CODE (*parm) != REFERENCE_TYPE)
12494 /* [temp.deduct.call]
12496 If P is not a reference type:
12498 --If A is an array type, the pointer type produced by the
12499 array-to-pointer standard conversion (_conv.array_) is
12500 used in place of A for type deduction; otherwise,
12502 --If A is a function type, the pointer type produced by
12503 the function-to-pointer standard conversion
12504 (_conv.func_) is used in place of A for type deduction;
12507 --If A is a cv-qualified type, the top level
12508 cv-qualifiers of A's type are ignored for type
12510 if (TREE_CODE (*arg) == ARRAY_TYPE)
12511 *arg = build_pointer_type (TREE_TYPE (*arg));
12512 else if (TREE_CODE (*arg) == FUNCTION_TYPE)
12513 *arg = build_pointer_type (*arg);
12515 *arg = TYPE_MAIN_VARIANT (*arg);
12518 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
12519 of the form T&&, where T is a template parameter, and the argument
12520 is an lvalue, T is deduced as A& */
12521 if (TREE_CODE (*parm) == REFERENCE_TYPE
12522 && TYPE_REF_IS_RVALUE (*parm)
12523 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
12524 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
12525 && arg_expr && real_lvalue_p (arg_expr))
12526 *arg = build_reference_type (*arg);
12528 /* [temp.deduct.call]
12530 If P is a cv-qualified type, the top level cv-qualifiers
12531 of P's type are ignored for type deduction. If P is a
12532 reference type, the type referred to by P is used for
12534 *parm = TYPE_MAIN_VARIANT (*parm);
12535 if (TREE_CODE (*parm) == REFERENCE_TYPE)
12537 *parm = TREE_TYPE (*parm);
12538 result |= UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
12541 /* DR 322. For conversion deduction, remove a reference type on parm
12542 too (which has been swapped into ARG). */
12543 if (strict == DEDUCE_CONV && TREE_CODE (*arg) == REFERENCE_TYPE)
12544 *arg = TREE_TYPE (*arg);
12549 /* Most parms like fn_type_unification.
12551 If SUBR is 1, we're being called recursively (to unify the
12552 arguments of a function or method parameter of a function
12556 type_unification_real (tree tparms,
12560 unsigned int xnargs,
12562 unification_kind_t strict,
12565 tree parm, arg, arg_expr;
12567 int ntparms = TREE_VEC_LENGTH (tparms);
12569 int saw_undeduced = 0;
12572 unsigned int nargs;
12575 gcc_assert (TREE_CODE (tparms) == TREE_VEC);
12576 gcc_assert (xparms == NULL_TREE || TREE_CODE (xparms) == TREE_LIST);
12577 gcc_assert (ntparms > 0);
12582 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL | UNIFY_ALLOW_MORE_CV_QUAL
12583 | UNIFY_ALLOW_DERIVED);
12587 sub_strict = UNIFY_ALLOW_LESS_CV_QUAL;
12591 sub_strict = UNIFY_ALLOW_NONE;
12595 gcc_unreachable ();
12604 while (parms && parms != void_list_node
12607 if (TREE_CODE (TREE_VALUE (parms)) == TYPE_PACK_EXPANSION)
12610 parm = TREE_VALUE (parms);
12611 parms = TREE_CHAIN (parms);
12616 if (arg == error_mark_node)
12618 if (arg == unknown_type_node)
12619 /* We can't deduce anything from this, but we might get all the
12620 template args from other function args. */
12623 /* Conversions will be performed on a function argument that
12624 corresponds with a function parameter that contains only
12625 non-deducible template parameters and explicitly specified
12626 template parameters. */
12627 if (!uses_template_parms (parm))
12632 type = TREE_TYPE (arg);
12636 if (same_type_p (parm, type))
12638 if (strict != DEDUCE_EXACT
12639 && can_convert_arg (parm, type, TYPE_P (arg) ? NULL_TREE : arg,
12648 gcc_assert (TREE_TYPE (arg) != NULL_TREE);
12649 if (type_unknown_p (arg))
12651 /* [temp.deduct.type]
12653 A template-argument can be deduced from a pointer to
12654 function or pointer to member function argument if
12655 the set of overloaded functions does not contain
12656 function templates and at most one of a set of
12657 overloaded functions provides a unique match. */
12658 if (resolve_overloaded_unification
12659 (tparms, targs, parm, arg, strict, sub_strict))
12665 arg = unlowered_expr_type (arg);
12666 if (arg == error_mark_node)
12671 int arg_strict = sub_strict;
12674 arg_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg,
12677 if (arg == init_list_type_node && arg_expr)
12679 if (unify (tparms, targs, parm, arg, arg_strict))
12686 && parms != void_list_node
12687 && TREE_CODE (TREE_VALUE (parms)) == TYPE_PACK_EXPANSION)
12689 /* Unify the remaining arguments with the pack expansion type. */
12691 tree parmvec = make_tree_vec (1);
12693 /* Allocate a TREE_VEC and copy in all of the arguments */
12694 argvec = make_tree_vec (nargs - ia);
12695 for (i = 0; ia < nargs; ++ia, ++i)
12696 TREE_VEC_ELT (argvec, i) = args[ia];
12698 /* Copy the parameter into parmvec. */
12699 TREE_VEC_ELT (parmvec, 0) = TREE_VALUE (parms);
12700 if (unify_pack_expansion (tparms, targs, parmvec, argvec, strict,
12701 /*call_args_p=*/true, /*subr=*/subr))
12704 /* Advance to the end of the list of parameters. */
12705 parms = TREE_CHAIN (parms);
12708 /* Fail if we've reached the end of the parm list, and more args
12709 are present, and the parm list isn't variadic. */
12710 if (ia < nargs && parms == void_list_node)
12712 /* Fail if parms are left and they don't have default values. */
12713 if (parms && parms != void_list_node
12714 && TREE_PURPOSE (parms) == NULL_TREE)
12718 for (i = 0; i < ntparms; i++)
12719 if (!TREE_VEC_ELT (targs, i))
12723 if (TREE_VEC_ELT (tparms, i) == error_mark_node)
12726 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
12728 /* If this is an undeduced nontype parameter that depends on
12729 a type parameter, try another pass; its type may have been
12730 deduced from a later argument than the one from which
12731 this parameter can be deduced. */
12732 if (TREE_CODE (tparm) == PARM_DECL
12733 && uses_template_parms (TREE_TYPE (tparm))
12734 && !saw_undeduced++)
12737 /* Core issue #226 (C++0x) [temp.deduct]:
12739 If a template argument has not been deduced, its
12740 default template argument, if any, is used.
12742 When we are in C++98 mode, TREE_PURPOSE will either
12743 be NULL_TREE or ERROR_MARK_NODE, so we do not need
12744 to explicitly check cxx_dialect here. */
12745 if (TREE_PURPOSE (TREE_VEC_ELT (tparms, i)))
12747 tree arg = tsubst (TREE_PURPOSE (TREE_VEC_ELT (tparms, i)),
12748 targs, tf_none, NULL_TREE);
12749 if (arg == error_mark_node)
12753 TREE_VEC_ELT (targs, i) = arg;
12758 /* If the type parameter is a parameter pack, then it will
12759 be deduced to an empty parameter pack. */
12760 if (template_parameter_pack_p (tparm))
12764 if (TREE_CODE (tparm) == TEMPLATE_PARM_INDEX)
12766 arg = make_node (NONTYPE_ARGUMENT_PACK);
12767 TREE_TYPE (arg) = TREE_TYPE (TEMPLATE_PARM_DECL (tparm));
12768 TREE_CONSTANT (arg) = 1;
12771 arg = make_node (TYPE_ARGUMENT_PACK);
12773 SET_ARGUMENT_PACK_ARGS (arg, make_tree_vec (0));
12775 TREE_VEC_ELT (targs, i) = arg;
12785 /* Subroutine of type_unification_real. Args are like the variables
12786 at the call site. ARG is an overloaded function (or template-id);
12787 we try deducing template args from each of the overloads, and if
12788 only one succeeds, we go with that. Modifies TARGS and returns
12789 true on success. */
12792 resolve_overloaded_unification (tree tparms,
12796 unification_kind_t strict,
12799 tree tempargs = copy_node (targs);
12801 tree goodfn = NULL_TREE;
12804 if (TREE_CODE (arg) == ADDR_EXPR)
12806 arg = TREE_OPERAND (arg, 0);
12812 if (TREE_CODE (arg) == COMPONENT_REF)
12813 /* Handle `&x' where `x' is some static or non-static member
12815 arg = TREE_OPERAND (arg, 1);
12817 if (TREE_CODE (arg) == OFFSET_REF)
12818 arg = TREE_OPERAND (arg, 1);
12820 /* Strip baselink information. */
12821 if (BASELINK_P (arg))
12822 arg = BASELINK_FUNCTIONS (arg);
12824 if (TREE_CODE (arg) == TEMPLATE_ID_EXPR)
12826 /* If we got some explicit template args, we need to plug them into
12827 the affected templates before we try to unify, in case the
12828 explicit args will completely resolve the templates in question. */
12830 tree expl_subargs = TREE_OPERAND (arg, 1);
12831 arg = TREE_OPERAND (arg, 0);
12833 for (; arg; arg = OVL_NEXT (arg))
12835 tree fn = OVL_CURRENT (arg);
12836 tree subargs, elem;
12838 if (TREE_CODE (fn) != TEMPLATE_DECL)
12841 ++processing_template_decl;
12842 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
12843 expl_subargs, /*check_ret=*/false);
12846 elem = tsubst (TREE_TYPE (fn), subargs, tf_none, NULL_TREE);
12847 if (try_one_overload (tparms, targs, tempargs, parm,
12848 elem, strict, sub_strict, addr_p)
12849 && (!goodfn || !decls_match (goodfn, elem)))
12855 --processing_template_decl;
12858 else if (TREE_CODE (arg) != OVERLOAD
12859 && TREE_CODE (arg) != FUNCTION_DECL)
12860 /* If ARG is, for example, "(0, &f)" then its type will be unknown
12861 -- but the deduction does not succeed because the expression is
12862 not just the function on its own. */
12865 for (; arg; arg = OVL_NEXT (arg))
12866 if (try_one_overload (tparms, targs, tempargs, parm,
12867 TREE_TYPE (OVL_CURRENT (arg)),
12868 strict, sub_strict, addr_p)
12869 && (!goodfn || !decls_match (goodfn, OVL_CURRENT (arg))))
12871 goodfn = OVL_CURRENT (arg);
12875 /* [temp.deduct.type] A template-argument can be deduced from a pointer
12876 to function or pointer to member function argument if the set of
12877 overloaded functions does not contain function templates and at most
12878 one of a set of overloaded functions provides a unique match.
12880 So if we found multiple possibilities, we return success but don't
12881 deduce anything. */
12885 int i = TREE_VEC_LENGTH (targs);
12887 if (TREE_VEC_ELT (tempargs, i))
12888 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (tempargs, i);
12896 /* Subroutine of resolve_overloaded_unification; does deduction for a single
12897 overload. Fills TARGS with any deduced arguments, or error_mark_node if
12898 different overloads deduce different arguments for a given parm.
12899 ADDR_P is true if the expression for which deduction is being
12900 performed was of the form "& fn" rather than simply "fn".
12902 Returns 1 on success. */
12905 try_one_overload (tree tparms,
12910 unification_kind_t strict,
12918 /* [temp.deduct.type] A template-argument can be deduced from a pointer
12919 to function or pointer to member function argument if the set of
12920 overloaded functions does not contain function templates and at most
12921 one of a set of overloaded functions provides a unique match.
12923 So if this is a template, just return success. */
12925 if (uses_template_parms (arg))
12928 if (TREE_CODE (arg) == METHOD_TYPE)
12929 arg = build_ptrmemfunc_type (build_pointer_type (arg));
12931 arg = build_pointer_type (arg);
12933 sub_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg, NULL);
12935 /* We don't copy orig_targs for this because if we have already deduced
12936 some template args from previous args, unify would complain when we
12937 try to deduce a template parameter for the same argument, even though
12938 there isn't really a conflict. */
12939 nargs = TREE_VEC_LENGTH (targs);
12940 tempargs = make_tree_vec (nargs);
12942 if (unify (tparms, tempargs, parm, arg, sub_strict) != 0)
12945 /* First make sure we didn't deduce anything that conflicts with
12946 explicitly specified args. */
12947 for (i = nargs; i--; )
12949 tree elt = TREE_VEC_ELT (tempargs, i);
12950 tree oldelt = TREE_VEC_ELT (orig_targs, i);
12954 else if (uses_template_parms (elt))
12955 /* Since we're unifying against ourselves, we will fill in
12956 template args used in the function parm list with our own
12957 template parms. Discard them. */
12958 TREE_VEC_ELT (tempargs, i) = NULL_TREE;
12959 else if (oldelt && !template_args_equal (oldelt, elt))
12963 for (i = nargs; i--; )
12965 tree elt = TREE_VEC_ELT (tempargs, i);
12968 TREE_VEC_ELT (targs, i) = elt;
12974 /* PARM is a template class (perhaps with unbound template
12975 parameters). ARG is a fully instantiated type. If ARG can be
12976 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
12977 TARGS are as for unify. */
12980 try_class_unification (tree tparms, tree targs, tree parm, tree arg)
12982 tree copy_of_targs;
12984 if (!CLASSTYPE_TEMPLATE_INFO (arg)
12985 || (most_general_template (CLASSTYPE_TI_TEMPLATE (arg))
12986 != most_general_template (CLASSTYPE_TI_TEMPLATE (parm))))
12989 /* We need to make a new template argument vector for the call to
12990 unify. If we used TARGS, we'd clutter it up with the result of
12991 the attempted unification, even if this class didn't work out.
12992 We also don't want to commit ourselves to all the unifications
12993 we've already done, since unification is supposed to be done on
12994 an argument-by-argument basis. In other words, consider the
12995 following pathological case:
12997 template <int I, int J, int K>
13000 template <int I, int J>
13001 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
13003 template <int I, int J, int K>
13004 void f(S<I, J, K>, S<I, I, I>);
13013 Now, by the time we consider the unification involving `s2', we
13014 already know that we must have `f<0, 0, 0>'. But, even though
13015 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
13016 because there are two ways to unify base classes of S<0, 1, 2>
13017 with S<I, I, I>. If we kept the already deduced knowledge, we
13018 would reject the possibility I=1. */
13019 copy_of_targs = make_tree_vec (TREE_VEC_LENGTH (targs));
13021 /* If unification failed, we're done. */
13022 if (unify (tparms, copy_of_targs, CLASSTYPE_TI_ARGS (parm),
13023 CLASSTYPE_TI_ARGS (arg), UNIFY_ALLOW_NONE))
13029 /* Given a template type PARM and a class type ARG, find the unique
13030 base type in ARG that is an instance of PARM. We do not examine
13031 ARG itself; only its base-classes. If there is not exactly one
13032 appropriate base class, return NULL_TREE. PARM may be the type of
13033 a partial specialization, as well as a plain template type. Used
13037 get_template_base (tree tparms, tree targs, tree parm, tree arg)
13039 tree rval = NULL_TREE;
13042 gcc_assert (RECORD_OR_UNION_CODE_P (TREE_CODE (arg)));
13044 binfo = TYPE_BINFO (complete_type (arg));
13046 /* The type could not be completed. */
13049 /* Walk in inheritance graph order. The search order is not
13050 important, and this avoids multiple walks of virtual bases. */
13051 for (binfo = TREE_CHAIN (binfo); binfo; binfo = TREE_CHAIN (binfo))
13053 tree r = try_class_unification (tparms, targs, parm, BINFO_TYPE (binfo));
13057 /* If there is more than one satisfactory baseclass, then:
13061 If they yield more than one possible deduced A, the type
13065 if (rval && !same_type_p (r, rval))
13075 /* Returns the level of DECL, which declares a template parameter. */
13078 template_decl_level (tree decl)
13080 switch (TREE_CODE (decl))
13083 case TEMPLATE_DECL:
13084 return TEMPLATE_TYPE_LEVEL (TREE_TYPE (decl));
13087 return TEMPLATE_PARM_LEVEL (DECL_INITIAL (decl));
13090 gcc_unreachable ();
13095 /* Decide whether ARG can be unified with PARM, considering only the
13096 cv-qualifiers of each type, given STRICT as documented for unify.
13097 Returns nonzero iff the unification is OK on that basis. */
13100 check_cv_quals_for_unify (int strict, tree arg, tree parm)
13102 int arg_quals = cp_type_quals (arg);
13103 int parm_quals = cp_type_quals (parm);
13105 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
13106 && !(strict & UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
13108 /* Although a CVR qualifier is ignored when being applied to a
13109 substituted template parameter ([8.3.2]/1 for example), that
13110 does not apply during deduction [14.8.2.4]/1, (even though
13111 that is not explicitly mentioned, [14.8.2.4]/9 indicates
13112 this). Except when we're allowing additional CV qualifiers
13113 at the outer level [14.8.2.1]/3,1st bullet. */
13114 if ((TREE_CODE (arg) == REFERENCE_TYPE
13115 || TREE_CODE (arg) == FUNCTION_TYPE
13116 || TREE_CODE (arg) == METHOD_TYPE)
13117 && (parm_quals & (TYPE_QUAL_CONST | TYPE_QUAL_VOLATILE)))
13120 if ((!POINTER_TYPE_P (arg) && TREE_CODE (arg) != TEMPLATE_TYPE_PARM)
13121 && (parm_quals & TYPE_QUAL_RESTRICT))
13125 if (!(strict & (UNIFY_ALLOW_MORE_CV_QUAL | UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
13126 && (arg_quals & parm_quals) != parm_quals)
13129 if (!(strict & (UNIFY_ALLOW_LESS_CV_QUAL | UNIFY_ALLOW_OUTER_LESS_CV_QUAL))
13130 && (parm_quals & arg_quals) != arg_quals)
13136 /* Determines the LEVEL and INDEX for the template parameter PARM. */
13138 template_parm_level_and_index (tree parm, int* level, int* index)
13140 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
13141 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
13142 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
13144 *index = TEMPLATE_TYPE_IDX (parm);
13145 *level = TEMPLATE_TYPE_LEVEL (parm);
13149 *index = TEMPLATE_PARM_IDX (parm);
13150 *level = TEMPLATE_PARM_LEVEL (parm);
13154 /* Unifies the remaining arguments in PACKED_ARGS with the pack
13155 expansion at the end of PACKED_PARMS. Returns 0 if the type
13156 deduction succeeds, 1 otherwise. STRICT is the same as in
13157 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
13158 call argument list. We'll need to adjust the arguments to make them
13159 types. SUBR tells us if this is from a recursive call to
13160 type_unification_real. */
13162 unify_pack_expansion (tree tparms, tree targs, tree packed_parms,
13163 tree packed_args, int strict, bool call_args_p,
13167 = TREE_VEC_ELT (packed_parms, TREE_VEC_LENGTH (packed_parms) - 1);
13168 tree pattern = PACK_EXPANSION_PATTERN (parm);
13169 tree pack, packs = NULL_TREE;
13170 int i, start = TREE_VEC_LENGTH (packed_parms) - 1;
13171 int len = TREE_VEC_LENGTH (packed_args);
13173 /* Determine the parameter packs we will be deducing from the
13174 pattern, and record their current deductions. */
13175 for (pack = PACK_EXPANSION_PARAMETER_PACKS (parm);
13176 pack; pack = TREE_CHAIN (pack))
13178 tree parm_pack = TREE_VALUE (pack);
13181 /* Determine the index and level of this parameter pack. */
13182 template_parm_level_and_index (parm_pack, &level, &idx);
13184 /* Keep track of the parameter packs and their corresponding
13186 packs = tree_cons (parm_pack, TMPL_ARG (targs, level, idx), packs);
13187 TREE_TYPE (packs) = make_tree_vec (len - start);
13190 /* Loop through all of the arguments that have not yet been
13191 unified and unify each with the pattern. */
13192 for (i = start; i < len; i++)
13194 tree parm = pattern;
13196 /* For each parameter pack, clear out the deduced value so that
13197 we can deduce it again. */
13198 for (pack = packs; pack; pack = TREE_CHAIN (pack))
13201 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
13203 TMPL_ARG (targs, level, idx) = NULL_TREE;
13206 /* Unify the pattern with the current argument. */
13208 tree arg = TREE_VEC_ELT (packed_args, i);
13209 tree arg_expr = NULL_TREE;
13210 int arg_strict = strict;
13211 bool skip_arg_p = false;
13217 /* This mirrors what we do in type_unification_real. */
13221 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL
13222 | UNIFY_ALLOW_MORE_CV_QUAL
13223 | UNIFY_ALLOW_DERIVED);
13227 sub_strict = UNIFY_ALLOW_LESS_CV_QUAL;
13231 sub_strict = UNIFY_ALLOW_NONE;
13235 gcc_unreachable ();
13240 gcc_assert (TREE_TYPE (arg) != NULL_TREE);
13241 if (type_unknown_p (arg))
13243 /* [temp.deduct.type] A template-argument can be
13244 deduced from a pointer to function or pointer
13245 to member function argument if the set of
13246 overloaded functions does not contain function
13247 templates and at most one of a set of
13248 overloaded functions provides a unique
13251 if (resolve_overloaded_unification
13252 (tparms, targs, parm, arg,
13253 (unification_kind_t) strict,
13263 arg = unlowered_expr_type (arg);
13264 if (arg == error_mark_node)
13269 arg_strict = sub_strict;
13273 maybe_adjust_types_for_deduction ((unification_kind_t) strict,
13274 &parm, &arg, arg_expr);
13279 if (unify (tparms, targs, parm, arg, arg_strict))
13284 /* For each parameter pack, collect the deduced value. */
13285 for (pack = packs; pack; pack = TREE_CHAIN (pack))
13288 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
13290 TREE_VEC_ELT (TREE_TYPE (pack), i - start) =
13291 TMPL_ARG (targs, level, idx);
13295 /* Verify that the results of unification with the parameter packs
13296 produce results consistent with what we've seen before, and make
13297 the deduced argument packs available. */
13298 for (pack = packs; pack; pack = TREE_CHAIN (pack))
13300 tree old_pack = TREE_VALUE (pack);
13301 tree new_args = TREE_TYPE (pack);
13302 int i, len = TREE_VEC_LENGTH (new_args);
13303 bool nondeduced_p = false;
13305 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
13306 actually deduce anything. */
13307 for (i = 0; i < len && !nondeduced_p; ++i)
13308 if (TREE_VEC_ELT (new_args, i) == NULL_TREE)
13309 nondeduced_p = true;
13313 if (old_pack && ARGUMENT_PACK_INCOMPLETE_P (old_pack))
13315 /* Prepend the explicit arguments onto NEW_ARGS. */
13316 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
13317 tree old_args = new_args;
13318 int i, explicit_len = TREE_VEC_LENGTH (explicit_args);
13319 int len = explicit_len + TREE_VEC_LENGTH (old_args);
13321 /* Copy the explicit arguments. */
13322 new_args = make_tree_vec (len);
13323 for (i = 0; i < explicit_len; i++)
13324 TREE_VEC_ELT (new_args, i) = TREE_VEC_ELT (explicit_args, i);
13326 /* Copy the deduced arguments. */
13327 for (; i < len; i++)
13328 TREE_VEC_ELT (new_args, i) =
13329 TREE_VEC_ELT (old_args, i - explicit_len);
13337 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
13339 /* Build the deduced *_ARGUMENT_PACK. */
13340 if (TREE_CODE (TREE_PURPOSE (pack)) == TEMPLATE_PARM_INDEX)
13342 result = make_node (NONTYPE_ARGUMENT_PACK);
13343 TREE_TYPE (result) =
13344 TREE_TYPE (TEMPLATE_PARM_DECL (TREE_PURPOSE (pack)));
13345 TREE_CONSTANT (result) = 1;
13348 result = make_node (TYPE_ARGUMENT_PACK);
13350 SET_ARGUMENT_PACK_ARGS (result, new_args);
13352 /* Note the deduced argument packs for this parameter
13354 TMPL_ARG (targs, level, idx) = result;
13356 else if (ARGUMENT_PACK_INCOMPLETE_P (old_pack)
13357 && (ARGUMENT_PACK_ARGS (old_pack)
13358 == ARGUMENT_PACK_EXPLICIT_ARGS (old_pack)))
13360 /* We only had the explicitly-provided arguments before, but
13361 now we have a complete set of arguments. */
13363 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
13364 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
13366 /* Keep the original deduced argument pack. */
13367 TMPL_ARG (targs, level, idx) = old_pack;
13369 SET_ARGUMENT_PACK_ARGS (old_pack, new_args);
13370 ARGUMENT_PACK_INCOMPLETE_P (old_pack) = 1;
13371 ARGUMENT_PACK_EXPLICIT_ARGS (old_pack) = explicit_args;
13373 else if (!comp_template_args (ARGUMENT_PACK_ARGS (old_pack),
13375 /* Inconsistent unification of this parameter pack. */
13381 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
13383 /* Keep the original deduced argument pack. */
13384 TMPL_ARG (targs, level, idx) = old_pack;
13391 /* Deduce the value of template parameters. TPARMS is the (innermost)
13392 set of template parameters to a template. TARGS is the bindings
13393 for those template parameters, as determined thus far; TARGS may
13394 include template arguments for outer levels of template parameters
13395 as well. PARM is a parameter to a template function, or a
13396 subcomponent of that parameter; ARG is the corresponding argument.
13397 This function attempts to match PARM with ARG in a manner
13398 consistent with the existing assignments in TARGS. If more values
13399 are deduced, then TARGS is updated.
13401 Returns 0 if the type deduction succeeds, 1 otherwise. The
13402 parameter STRICT is a bitwise or of the following flags:
13405 Require an exact match between PARM and ARG.
13406 UNIFY_ALLOW_MORE_CV_QUAL:
13407 Allow the deduced ARG to be more cv-qualified (by qualification
13408 conversion) than ARG.
13409 UNIFY_ALLOW_LESS_CV_QUAL:
13410 Allow the deduced ARG to be less cv-qualified than ARG.
13411 UNIFY_ALLOW_DERIVED:
13412 Allow the deduced ARG to be a template base class of ARG,
13413 or a pointer to a template base class of the type pointed to by
13415 UNIFY_ALLOW_INTEGER:
13416 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
13417 case for more information.
13418 UNIFY_ALLOW_OUTER_LEVEL:
13419 This is the outermost level of a deduction. Used to determine validity
13420 of qualification conversions. A valid qualification conversion must
13421 have const qualified pointers leading up to the inner type which
13422 requires additional CV quals, except at the outer level, where const
13423 is not required [conv.qual]. It would be normal to set this flag in
13424 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
13425 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
13426 This is the outermost level of a deduction, and PARM can be more CV
13427 qualified at this point.
13428 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
13429 This is the outermost level of a deduction, and PARM can be less CV
13430 qualified at this point. */
13433 unify (tree tparms, tree targs, tree parm, tree arg, int strict)
13438 int strict_in = strict;
13440 /* I don't think this will do the right thing with respect to types.
13441 But the only case I've seen it in so far has been array bounds, where
13442 signedness is the only information lost, and I think that will be
13444 while (TREE_CODE (parm) == NOP_EXPR)
13445 parm = TREE_OPERAND (parm, 0);
13447 if (arg == error_mark_node)
13449 if (arg == unknown_type_node
13450 || arg == init_list_type_node)
13451 /* We can't deduce anything from this, but we might get all the
13452 template args from other function args. */
13455 /* If PARM uses template parameters, then we can't bail out here,
13456 even if ARG == PARM, since we won't record unifications for the
13457 template parameters. We might need them if we're trying to
13458 figure out which of two things is more specialized. */
13459 if (arg == parm && !uses_template_parms (parm))
13462 /* Handle init lists early, so the rest of the function can assume
13463 we're dealing with a type. */
13464 if (BRACE_ENCLOSED_INITIALIZER_P (arg))
13469 if (!is_std_init_list (parm))
13470 /* We can only deduce from an initializer list argument if the
13471 parameter is std::initializer_list; otherwise this is a
13472 non-deduced context. */
13475 elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (parm), 0);
13477 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg), i, elt)
13479 int elt_strict = strict;
13480 if (!BRACE_ENCLOSED_INITIALIZER_P (elt))
13482 tree type = TREE_TYPE (elt);
13483 /* It should only be possible to get here for a call. */
13484 gcc_assert (elt_strict & UNIFY_ALLOW_OUTER_LEVEL);
13485 elt_strict |= maybe_adjust_types_for_deduction
13486 (DEDUCE_CALL, &elttype, &type, elt);
13490 if (unify (tparms, targs, elttype, elt, elt_strict))
13496 /* Immediately reject some pairs that won't unify because of
13497 cv-qualification mismatches. */
13498 if (TREE_CODE (arg) == TREE_CODE (parm)
13500 /* It is the elements of the array which hold the cv quals of an array
13501 type, and the elements might be template type parms. We'll check
13502 when we recurse. */
13503 && TREE_CODE (arg) != ARRAY_TYPE
13504 /* We check the cv-qualifiers when unifying with template type
13505 parameters below. We want to allow ARG `const T' to unify with
13506 PARM `T' for example, when computing which of two templates
13507 is more specialized, for example. */
13508 && TREE_CODE (arg) != TEMPLATE_TYPE_PARM
13509 && !check_cv_quals_for_unify (strict_in, arg, parm))
13512 if (!(strict & UNIFY_ALLOW_OUTER_LEVEL)
13513 && TYPE_P (parm) && !CP_TYPE_CONST_P (parm))
13514 strict &= ~UNIFY_ALLOW_MORE_CV_QUAL;
13515 strict &= ~UNIFY_ALLOW_OUTER_LEVEL;
13516 strict &= ~UNIFY_ALLOW_DERIVED;
13517 strict &= ~UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
13518 strict &= ~UNIFY_ALLOW_OUTER_LESS_CV_QUAL;
13520 switch (TREE_CODE (parm))
13522 case TYPENAME_TYPE:
13524 case UNBOUND_CLASS_TEMPLATE:
13525 /* In a type which contains a nested-name-specifier, template
13526 argument values cannot be deduced for template parameters used
13527 within the nested-name-specifier. */
13530 case TEMPLATE_TYPE_PARM:
13531 case TEMPLATE_TEMPLATE_PARM:
13532 case BOUND_TEMPLATE_TEMPLATE_PARM:
13533 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
13534 if (tparm == error_mark_node)
13537 if (TEMPLATE_TYPE_LEVEL (parm)
13538 != template_decl_level (tparm))
13539 /* The PARM is not one we're trying to unify. Just check
13540 to see if it matches ARG. */
13541 return (TREE_CODE (arg) == TREE_CODE (parm)
13542 && same_type_p (parm, arg)) ? 0 : 1;
13543 idx = TEMPLATE_TYPE_IDX (parm);
13544 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
13545 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, idx));
13547 /* Check for mixed types and values. */
13548 if ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
13549 && TREE_CODE (tparm) != TYPE_DECL)
13550 || (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
13551 && TREE_CODE (tparm) != TEMPLATE_DECL))
13554 if (TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
13556 /* ARG must be constructed from a template class or a template
13557 template parameter. */
13558 if (TREE_CODE (arg) != BOUND_TEMPLATE_TEMPLATE_PARM
13559 && !CLASSTYPE_SPECIALIZATION_OF_PRIMARY_TEMPLATE_P (arg))
13563 tree parmvec = TYPE_TI_ARGS (parm);
13564 tree argvec = INNERMOST_TEMPLATE_ARGS (TYPE_TI_ARGS (arg));
13566 = DECL_INNERMOST_TEMPLATE_PARMS
13567 (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (parm));
13569 int parm_variadic_p = 0;
13571 /* The resolution to DR150 makes clear that default
13572 arguments for an N-argument may not be used to bind T
13573 to a template template parameter with fewer than N
13574 parameters. It is not safe to permit the binding of
13575 default arguments as an extension, as that may change
13576 the meaning of a conforming program. Consider:
13578 struct Dense { static const unsigned int dim = 1; };
13580 template <template <typename> class View,
13582 void operator+(float, View<Block> const&);
13584 template <typename Block,
13585 unsigned int Dim = Block::dim>
13586 struct Lvalue_proxy { operator float() const; };
13590 Lvalue_proxy<Dense> p;
13595 Here, if Lvalue_proxy is permitted to bind to View, then
13596 the global operator+ will be used; if they are not, the
13597 Lvalue_proxy will be converted to float. */
13598 if (coerce_template_parms (parm_parms,
13600 TYPE_TI_TEMPLATE (parm),
13602 /*require_all_args=*/true,
13603 /*use_default_args=*/false)
13604 == error_mark_node)
13607 /* Deduce arguments T, i from TT<T> or TT<i>.
13608 We check each element of PARMVEC and ARGVEC individually
13609 rather than the whole TREE_VEC since they can have
13610 different number of elements. */
13612 parmvec = expand_template_argument_pack (parmvec);
13613 argvec = expand_template_argument_pack (argvec);
13615 len = TREE_VEC_LENGTH (parmvec);
13617 /* Check if the parameters end in a pack, making them
13620 && PACK_EXPANSION_P (TREE_VEC_ELT (parmvec, len - 1)))
13621 parm_variadic_p = 1;
13623 if (TREE_VEC_LENGTH (argvec) < len - parm_variadic_p)
13626 for (i = 0; i < len - parm_variadic_p; ++i)
13628 if (unify (tparms, targs,
13629 TREE_VEC_ELT (parmvec, i),
13630 TREE_VEC_ELT (argvec, i),
13635 if (parm_variadic_p
13636 && unify_pack_expansion (tparms, targs,
13639 /*call_args_p=*/false,
13643 arg = TYPE_TI_TEMPLATE (arg);
13645 /* Fall through to deduce template name. */
13648 if (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
13649 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
13651 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
13653 /* Simple cases: Value already set, does match or doesn't. */
13654 if (targ != NULL_TREE && template_args_equal (targ, arg))
13661 /* If PARM is `const T' and ARG is only `int', we don't have
13662 a match unless we are allowing additional qualification.
13663 If ARG is `const int' and PARM is just `T' that's OK;
13664 that binds `const int' to `T'. */
13665 if (!check_cv_quals_for_unify (strict_in | UNIFY_ALLOW_LESS_CV_QUAL,
13669 /* Consider the case where ARG is `const volatile int' and
13670 PARM is `const T'. Then, T should be `volatile int'. */
13671 arg = cp_build_qualified_type_real
13672 (arg, cp_type_quals (arg) & ~cp_type_quals (parm), tf_none);
13673 if (arg == error_mark_node)
13676 /* Simple cases: Value already set, does match or doesn't. */
13677 if (targ != NULL_TREE && same_type_p (targ, arg))
13682 /* Make sure that ARG is not a variable-sized array. (Note
13683 that were talking about variable-sized arrays (like
13684 `int[n]'), rather than arrays of unknown size (like
13685 `int[]').) We'll get very confused by such a type since
13686 the bound of the array will not be computable in an
13687 instantiation. Besides, such types are not allowed in
13688 ISO C++, so we can do as we please here. */
13689 if (variably_modified_type_p (arg, NULL_TREE))
13692 /* Strip typedefs as in convert_template_argument. */
13693 arg = strip_typedefs (arg);
13696 /* If ARG is a parameter pack or an expansion, we cannot unify
13697 against it unless PARM is also a parameter pack. */
13698 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
13699 && !template_parameter_pack_p (parm))
13702 /* If the argument deduction results is a METHOD_TYPE,
13703 then there is a problem.
13704 METHOD_TYPE doesn't map to any real C++ type the result of
13705 the deduction can not be of that type. */
13706 if (TREE_CODE (arg) == METHOD_TYPE)
13709 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
13712 case TEMPLATE_PARM_INDEX:
13713 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
13714 if (tparm == error_mark_node)
13717 if (TEMPLATE_PARM_LEVEL (parm)
13718 != template_decl_level (tparm))
13719 /* The PARM is not one we're trying to unify. Just check
13720 to see if it matches ARG. */
13721 return !(TREE_CODE (arg) == TREE_CODE (parm)
13722 && cp_tree_equal (parm, arg));
13724 idx = TEMPLATE_PARM_IDX (parm);
13725 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
13728 return !cp_tree_equal (targ, arg);
13730 /* [temp.deduct.type] If, in the declaration of a function template
13731 with a non-type template-parameter, the non-type
13732 template-parameter is used in an expression in the function
13733 parameter-list and, if the corresponding template-argument is
13734 deduced, the template-argument type shall match the type of the
13735 template-parameter exactly, except that a template-argument
13736 deduced from an array bound may be of any integral type.
13737 The non-type parameter might use already deduced type parameters. */
13738 tparm = tsubst (TREE_TYPE (parm), targs, 0, NULL_TREE);
13739 if (!TREE_TYPE (arg))
13740 /* Template-parameter dependent expression. Just accept it for now.
13741 It will later be processed in convert_template_argument. */
13743 else if (same_type_p (TREE_TYPE (arg), tparm))
13745 else if ((strict & UNIFY_ALLOW_INTEGER)
13746 && (TREE_CODE (tparm) == INTEGER_TYPE
13747 || TREE_CODE (tparm) == BOOLEAN_TYPE))
13748 /* Convert the ARG to the type of PARM; the deduced non-type
13749 template argument must exactly match the types of the
13750 corresponding parameter. */
13751 arg = fold (build_nop (tparm, arg));
13752 else if (uses_template_parms (tparm))
13753 /* We haven't deduced the type of this parameter yet. Try again
13759 /* If ARG is a parameter pack or an expansion, we cannot unify
13760 against it unless PARM is also a parameter pack. */
13761 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
13762 && !TEMPLATE_PARM_PARAMETER_PACK (parm))
13765 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
13770 /* A pointer-to-member constant can be unified only with
13771 another constant. */
13772 if (TREE_CODE (arg) != PTRMEM_CST)
13775 /* Just unify the class member. It would be useless (and possibly
13776 wrong, depending on the strict flags) to unify also
13777 PTRMEM_CST_CLASS, because we want to be sure that both parm and
13778 arg refer to the same variable, even if through different
13779 classes. For instance:
13781 struct A { int x; };
13784 Unification of &A::x and &B::x must succeed. */
13785 return unify (tparms, targs, PTRMEM_CST_MEMBER (parm),
13786 PTRMEM_CST_MEMBER (arg), strict);
13791 if (TREE_CODE (arg) != POINTER_TYPE)
13794 /* [temp.deduct.call]
13796 A can be another pointer or pointer to member type that can
13797 be converted to the deduced A via a qualification
13798 conversion (_conv.qual_).
13800 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
13801 This will allow for additional cv-qualification of the
13802 pointed-to types if appropriate. */
13804 if (TREE_CODE (TREE_TYPE (arg)) == RECORD_TYPE)
13805 /* The derived-to-base conversion only persists through one
13806 level of pointers. */
13807 strict |= (strict_in & UNIFY_ALLOW_DERIVED);
13809 return unify (tparms, targs, TREE_TYPE (parm),
13810 TREE_TYPE (arg), strict);
13813 case REFERENCE_TYPE:
13814 if (TREE_CODE (arg) != REFERENCE_TYPE)
13816 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
13817 strict & UNIFY_ALLOW_MORE_CV_QUAL);
13820 if (TREE_CODE (arg) != ARRAY_TYPE)
13822 if ((TYPE_DOMAIN (parm) == NULL_TREE)
13823 != (TYPE_DOMAIN (arg) == NULL_TREE))
13825 if (TYPE_DOMAIN (parm) != NULL_TREE)
13832 /* Our representation of array types uses "N - 1" as the
13833 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
13834 not an integer constant. We cannot unify arbitrarily
13835 complex expressions, so we eliminate the MINUS_EXPRs
13837 parm_max = TYPE_MAX_VALUE (TYPE_DOMAIN (parm));
13838 parm_cst = TREE_CODE (parm_max) == INTEGER_CST;
13841 gcc_assert (TREE_CODE (parm_max) == MINUS_EXPR);
13842 parm_max = TREE_OPERAND (parm_max, 0);
13844 arg_max = TYPE_MAX_VALUE (TYPE_DOMAIN (arg));
13845 arg_cst = TREE_CODE (arg_max) == INTEGER_CST;
13848 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
13849 trying to unify the type of a variable with the type
13850 of a template parameter. For example:
13852 template <unsigned int N>
13853 void f (char (&) [N]);
13860 Here, the type of the ARG will be "int [g(i)]", and
13861 may be a SAVE_EXPR, etc. */
13862 if (TREE_CODE (arg_max) != MINUS_EXPR)
13864 arg_max = TREE_OPERAND (arg_max, 0);
13867 /* If only one of the bounds used a MINUS_EXPR, compensate
13868 by adding one to the other bound. */
13869 if (parm_cst && !arg_cst)
13870 parm_max = fold_build2 (PLUS_EXPR,
13874 else if (arg_cst && !parm_cst)
13875 arg_max = fold_build2 (PLUS_EXPR,
13880 if (unify (tparms, targs, parm_max, arg_max, UNIFY_ALLOW_INTEGER))
13883 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
13884 strict & UNIFY_ALLOW_MORE_CV_QUAL);
13891 case ENUMERAL_TYPE:
13893 if (TREE_CODE (arg) != TREE_CODE (parm))
13896 /* We have already checked cv-qualification at the top of the
13898 if (!same_type_ignoring_top_level_qualifiers_p (arg, parm))
13901 /* As far as unification is concerned, this wins. Later checks
13902 will invalidate it if necessary. */
13905 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
13906 /* Type INTEGER_CST can come from ordinary constant template args. */
13908 while (TREE_CODE (arg) == NOP_EXPR)
13909 arg = TREE_OPERAND (arg, 0);
13911 if (TREE_CODE (arg) != INTEGER_CST)
13913 return !tree_int_cst_equal (parm, arg);
13918 if (TREE_CODE (arg) != TREE_VEC)
13920 if (TREE_VEC_LENGTH (parm) != TREE_VEC_LENGTH (arg))
13922 for (i = 0; i < TREE_VEC_LENGTH (parm); ++i)
13923 if (unify (tparms, targs,
13924 TREE_VEC_ELT (parm, i), TREE_VEC_ELT (arg, i),
13932 if (TREE_CODE (arg) != TREE_CODE (parm))
13935 if (TYPE_PTRMEMFUNC_P (parm))
13937 if (!TYPE_PTRMEMFUNC_P (arg))
13940 return unify (tparms, targs,
13941 TYPE_PTRMEMFUNC_FN_TYPE (parm),
13942 TYPE_PTRMEMFUNC_FN_TYPE (arg),
13946 if (CLASSTYPE_TEMPLATE_INFO (parm))
13948 tree t = NULL_TREE;
13950 if (strict_in & UNIFY_ALLOW_DERIVED)
13952 /* First, we try to unify the PARM and ARG directly. */
13953 t = try_class_unification (tparms, targs,
13958 /* Fallback to the special case allowed in
13959 [temp.deduct.call]:
13961 If P is a class, and P has the form
13962 template-id, then A can be a derived class of
13963 the deduced A. Likewise, if P is a pointer to
13964 a class of the form template-id, A can be a
13965 pointer to a derived class pointed to by the
13967 t = get_template_base (tparms, targs, parm, arg);
13973 else if (CLASSTYPE_TEMPLATE_INFO (arg)
13974 && (CLASSTYPE_TI_TEMPLATE (parm)
13975 == CLASSTYPE_TI_TEMPLATE (arg)))
13976 /* Perhaps PARM is something like S<U> and ARG is S<int>.
13977 Then, we should unify `int' and `U'. */
13980 /* There's no chance of unification succeeding. */
13983 return unify (tparms, targs, CLASSTYPE_TI_ARGS (parm),
13984 CLASSTYPE_TI_ARGS (t), UNIFY_ALLOW_NONE);
13986 else if (!same_type_ignoring_top_level_qualifiers_p (parm, arg))
13991 case FUNCTION_TYPE:
13993 unsigned int nargs;
13998 if (TREE_CODE (arg) != TREE_CODE (parm))
14001 /* CV qualifications for methods can never be deduced, they must
14002 match exactly. We need to check them explicitly here,
14003 because type_unification_real treats them as any other
14004 cv-qualified parameter. */
14005 if (TREE_CODE (parm) == METHOD_TYPE
14006 && (!check_cv_quals_for_unify
14008 TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (arg))),
14009 TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (parm))))))
14012 if (unify (tparms, targs, TREE_TYPE (parm),
14013 TREE_TYPE (arg), UNIFY_ALLOW_NONE))
14016 nargs = list_length (TYPE_ARG_TYPES (arg));
14017 args = XALLOCAVEC (tree, nargs);
14018 for (a = TYPE_ARG_TYPES (arg), i = 0;
14019 a != NULL_TREE && a != void_list_node;
14020 a = TREE_CHAIN (a), ++i)
14021 args[i] = TREE_VALUE (a);
14024 return type_unification_real (tparms, targs, TYPE_ARG_TYPES (parm),
14025 args, nargs, 1, DEDUCE_EXACT,
14030 /* Unify a pointer to member with a pointer to member function, which
14031 deduces the type of the member as a function type. */
14032 if (TYPE_PTRMEMFUNC_P (arg))
14036 cp_cv_quals cv_quals;
14038 /* Check top-level cv qualifiers */
14039 if (!check_cv_quals_for_unify (UNIFY_ALLOW_NONE, arg, parm))
14042 if (unify (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
14043 TYPE_PTRMEMFUNC_OBJECT_TYPE (arg), UNIFY_ALLOW_NONE))
14046 /* Determine the type of the function we are unifying against. */
14047 method_type = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (arg));
14049 build_function_type (TREE_TYPE (method_type),
14050 TREE_CHAIN (TYPE_ARG_TYPES (method_type)));
14052 /* Extract the cv-qualifiers of the member function from the
14053 implicit object parameter and place them on the function
14054 type to be restored later. */
14056 cp_type_quals(TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (method_type))));
14057 fntype = build_qualified_type (fntype, cv_quals);
14058 return unify (tparms, targs, TREE_TYPE (parm), fntype, strict);
14061 if (TREE_CODE (arg) != OFFSET_TYPE)
14063 if (unify (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
14064 TYPE_OFFSET_BASETYPE (arg), UNIFY_ALLOW_NONE))
14066 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
14070 if (DECL_TEMPLATE_PARM_P (parm))
14071 return unify (tparms, targs, DECL_INITIAL (parm), arg, strict);
14072 if (arg != integral_constant_value (parm))
14077 case TEMPLATE_DECL:
14078 /* Matched cases are handled by the ARG == PARM test above. */
14081 case TYPE_ARGUMENT_PACK:
14082 case NONTYPE_ARGUMENT_PACK:
14084 tree packed_parms = ARGUMENT_PACK_ARGS (parm);
14085 tree packed_args = ARGUMENT_PACK_ARGS (arg);
14086 int i, len = TREE_VEC_LENGTH (packed_parms);
14087 int argslen = TREE_VEC_LENGTH (packed_args);
14088 int parm_variadic_p = 0;
14090 for (i = 0; i < len; ++i)
14092 if (PACK_EXPANSION_P (TREE_VEC_ELT (packed_parms, i)))
14095 /* We can unify against something with a trailing
14097 parm_variadic_p = 1;
14099 /* Since there is something following the pack
14100 expansion, we cannot unify this template argument
14107 /* If we don't have enough arguments to satisfy the parameters
14108 (not counting the pack expression at the end), or we have
14109 too many arguments for a parameter list that doesn't end in
14110 a pack expression, we can't unify. */
14111 if (argslen < (len - parm_variadic_p)
14112 || (argslen > len && !parm_variadic_p))
14115 /* Unify all of the parameters that precede the (optional)
14116 pack expression. */
14117 for (i = 0; i < len - parm_variadic_p; ++i)
14119 if (unify (tparms, targs, TREE_VEC_ELT (packed_parms, i),
14120 TREE_VEC_ELT (packed_args, i), strict))
14124 if (parm_variadic_p)
14125 return unify_pack_expansion (tparms, targs,
14126 packed_parms, packed_args,
14127 strict, /*call_args_p=*/false,
14135 case DECLTYPE_TYPE:
14136 /* Cannot deduce anything from TYPEOF_TYPE or DECLTYPE_TYPE
14141 /* Unification fails if we hit an error node. */
14145 gcc_assert (EXPR_P (parm));
14147 /* We must be looking at an expression. This can happen with
14151 void foo(S<I>, S<I + 2>);
14153 This is a "nondeduced context":
14157 The nondeduced contexts are:
14159 --A type that is a template-id in which one or more of
14160 the template-arguments is an expression that references
14161 a template-parameter.
14163 In these cases, we assume deduction succeeded, but don't
14164 actually infer any unifications. */
14166 if (!uses_template_parms (parm)
14167 && !template_args_equal (parm, arg))
14174 /* Note that DECL can be defined in this translation unit, if
14178 mark_definable (tree decl)
14181 DECL_NOT_REALLY_EXTERN (decl) = 1;
14182 FOR_EACH_CLONE (clone, decl)
14183 DECL_NOT_REALLY_EXTERN (clone) = 1;
14186 /* Called if RESULT is explicitly instantiated, or is a member of an
14187 explicitly instantiated class. */
14190 mark_decl_instantiated (tree result, int extern_p)
14192 SET_DECL_EXPLICIT_INSTANTIATION (result);
14194 /* If this entity has already been written out, it's too late to
14195 make any modifications. */
14196 if (TREE_ASM_WRITTEN (result))
14199 if (TREE_CODE (result) != FUNCTION_DECL)
14200 /* The TREE_PUBLIC flag for function declarations will have been
14201 set correctly by tsubst. */
14202 TREE_PUBLIC (result) = 1;
14204 /* This might have been set by an earlier implicit instantiation. */
14205 DECL_COMDAT (result) = 0;
14208 DECL_NOT_REALLY_EXTERN (result) = 0;
14211 mark_definable (result);
14212 /* Always make artificials weak. */
14213 if (DECL_ARTIFICIAL (result) && flag_weak)
14214 comdat_linkage (result);
14215 /* For WIN32 we also want to put explicit instantiations in
14216 linkonce sections. */
14217 else if (TREE_PUBLIC (result))
14218 maybe_make_one_only (result);
14221 /* If EXTERN_P, then this function will not be emitted -- unless
14222 followed by an explicit instantiation, at which point its linkage
14223 will be adjusted. If !EXTERN_P, then this function will be
14224 emitted here. In neither circumstance do we want
14225 import_export_decl to adjust the linkage. */
14226 DECL_INTERFACE_KNOWN (result) = 1;
14229 /* Given two function templates PAT1 and PAT2, return:
14231 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
14232 -1 if PAT2 is more specialized than PAT1.
14233 0 if neither is more specialized.
14235 LEN indicates the number of parameters we should consider
14236 (defaulted parameters should not be considered).
14238 The 1998 std underspecified function template partial ordering, and
14239 DR214 addresses the issue. We take pairs of arguments, one from
14240 each of the templates, and deduce them against each other. One of
14241 the templates will be more specialized if all the *other*
14242 template's arguments deduce against its arguments and at least one
14243 of its arguments *does* *not* deduce against the other template's
14244 corresponding argument. Deduction is done as for class templates.
14245 The arguments used in deduction have reference and top level cv
14246 qualifiers removed. Iff both arguments were originally reference
14247 types *and* deduction succeeds in both directions, the template
14248 with the more cv-qualified argument wins for that pairing (if
14249 neither is more cv-qualified, they both are equal). Unlike regular
14250 deduction, after all the arguments have been deduced in this way,
14251 we do *not* verify the deduced template argument values can be
14252 substituted into non-deduced contexts, nor do we have to verify
14253 that all template arguments have been deduced. */
14256 more_specialized_fn (tree pat1, tree pat2, int len)
14258 tree decl1 = DECL_TEMPLATE_RESULT (pat1);
14259 tree decl2 = DECL_TEMPLATE_RESULT (pat2);
14260 tree targs1 = make_tree_vec (DECL_NTPARMS (pat1));
14261 tree targs2 = make_tree_vec (DECL_NTPARMS (pat2));
14262 tree tparms1 = DECL_INNERMOST_TEMPLATE_PARMS (pat1);
14263 tree tparms2 = DECL_INNERMOST_TEMPLATE_PARMS (pat2);
14264 tree args1 = TYPE_ARG_TYPES (TREE_TYPE (decl1));
14265 tree args2 = TYPE_ARG_TYPES (TREE_TYPE (decl2));
14269 /* Remove the this parameter from non-static member functions. If
14270 one is a non-static member function and the other is not a static
14271 member function, remove the first parameter from that function
14272 also. This situation occurs for operator functions where we
14273 locate both a member function (with this pointer) and non-member
14274 operator (with explicit first operand). */
14275 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl1))
14277 len--; /* LEN is the number of significant arguments for DECL1 */
14278 args1 = TREE_CHAIN (args1);
14279 if (!DECL_STATIC_FUNCTION_P (decl2))
14280 args2 = TREE_CHAIN (args2);
14282 else if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl2))
14284 args2 = TREE_CHAIN (args2);
14285 if (!DECL_STATIC_FUNCTION_P (decl1))
14288 args1 = TREE_CHAIN (args1);
14292 /* If only one is a conversion operator, they are unordered. */
14293 if (DECL_CONV_FN_P (decl1) != DECL_CONV_FN_P (decl2))
14296 /* Consider the return type for a conversion function */
14297 if (DECL_CONV_FN_P (decl1))
14299 args1 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl1)), args1);
14300 args2 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl2)), args2);
14304 processing_template_decl++;
14307 /* Stop when an ellipsis is seen. */
14308 && args1 != NULL_TREE && args2 != NULL_TREE)
14310 tree arg1 = TREE_VALUE (args1);
14311 tree arg2 = TREE_VALUE (args2);
14312 int deduce1, deduce2;
14316 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
14317 && TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
14319 /* When both arguments are pack expansions, we need only
14320 unify the patterns themselves. */
14321 arg1 = PACK_EXPANSION_PATTERN (arg1);
14322 arg2 = PACK_EXPANSION_PATTERN (arg2);
14324 /* This is the last comparison we need to do. */
14328 if (TREE_CODE (arg1) == REFERENCE_TYPE)
14330 arg1 = TREE_TYPE (arg1);
14331 quals1 = cp_type_quals (arg1);
14334 if (TREE_CODE (arg2) == REFERENCE_TYPE)
14336 arg2 = TREE_TYPE (arg2);
14337 quals2 = cp_type_quals (arg2);
14340 if ((quals1 < 0) != (quals2 < 0))
14342 /* Only of the args is a reference, see if we should apply
14343 array/function pointer decay to it. This is not part of
14344 DR214, but is, IMHO, consistent with the deduction rules
14345 for the function call itself, and with our earlier
14346 implementation of the underspecified partial ordering
14347 rules. (nathan). */
14350 switch (TREE_CODE (arg1))
14353 arg1 = TREE_TYPE (arg1);
14355 case FUNCTION_TYPE:
14356 arg1 = build_pointer_type (arg1);
14365 switch (TREE_CODE (arg2))
14368 arg2 = TREE_TYPE (arg2);
14370 case FUNCTION_TYPE:
14371 arg2 = build_pointer_type (arg2);
14380 arg1 = TYPE_MAIN_VARIANT (arg1);
14381 arg2 = TYPE_MAIN_VARIANT (arg2);
14383 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION)
14385 int i, len2 = list_length (args2);
14386 tree parmvec = make_tree_vec (1);
14387 tree argvec = make_tree_vec (len2);
14390 /* Setup the parameter vector, which contains only ARG1. */
14391 TREE_VEC_ELT (parmvec, 0) = arg1;
14393 /* Setup the argument vector, which contains the remaining
14395 for (i = 0; i < len2; i++, ta = TREE_CHAIN (ta))
14396 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
14398 deduce1 = !unify_pack_expansion (tparms1, targs1, parmvec,
14399 argvec, UNIFY_ALLOW_NONE,
14400 /*call_args_p=*/false,
14403 /* We cannot deduce in the other direction, because ARG1 is
14404 a pack expansion but ARG2 is not. */
14407 else if (TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
14409 int i, len1 = list_length (args1);
14410 tree parmvec = make_tree_vec (1);
14411 tree argvec = make_tree_vec (len1);
14414 /* Setup the parameter vector, which contains only ARG1. */
14415 TREE_VEC_ELT (parmvec, 0) = arg2;
14417 /* Setup the argument vector, which contains the remaining
14419 for (i = 0; i < len1; i++, ta = TREE_CHAIN (ta))
14420 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
14422 deduce2 = !unify_pack_expansion (tparms2, targs2, parmvec,
14423 argvec, UNIFY_ALLOW_NONE,
14424 /*call_args_p=*/false,
14427 /* We cannot deduce in the other direction, because ARG2 is
14428 a pack expansion but ARG1 is not.*/
14434 /* The normal case, where neither argument is a pack
14436 deduce1 = !unify (tparms1, targs1, arg1, arg2, UNIFY_ALLOW_NONE);
14437 deduce2 = !unify (tparms2, targs2, arg2, arg1, UNIFY_ALLOW_NONE);
14444 if (better1 < 0 && better2 < 0)
14445 /* We've failed to deduce something in either direction.
14446 These must be unordered. */
14449 if (deduce1 && deduce2 && quals1 >= 0 && quals2 >= 0)
14451 /* Deduces in both directions, see if quals can
14452 disambiguate. Pretend the worse one failed to deduce. */
14453 if ((quals1 & quals2) == quals2)
14455 if ((quals1 & quals2) == quals1)
14458 if (deduce1 && !deduce2 && !better2)
14460 if (deduce2 && !deduce1 && !better1)
14463 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
14464 || TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
14465 /* We have already processed all of the arguments in our
14466 handing of the pack expansion type. */
14469 args1 = TREE_CHAIN (args1);
14470 args2 = TREE_CHAIN (args2);
14473 processing_template_decl--;
14475 /* All things being equal, if the next argument is a pack expansion
14476 for one function but not for the other, prefer the
14477 non-variadic function. */
14478 if ((better1 > 0) - (better2 > 0) == 0
14479 && args1 && TREE_VALUE (args1)
14480 && args2 && TREE_VALUE (args2))
14482 if (TREE_CODE (TREE_VALUE (args1)) == TYPE_PACK_EXPANSION)
14483 return TREE_CODE (TREE_VALUE (args2)) == TYPE_PACK_EXPANSION ? 0 : -1;
14484 else if (TREE_CODE (TREE_VALUE (args2)) == TYPE_PACK_EXPANSION)
14488 return (better1 > 0) - (better2 > 0);
14491 /* Determine which of two partial specializations is more specialized.
14493 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
14494 to the first partial specialization. The TREE_VALUE is the
14495 innermost set of template parameters for the partial
14496 specialization. PAT2 is similar, but for the second template.
14498 Return 1 if the first partial specialization is more specialized;
14499 -1 if the second is more specialized; 0 if neither is more
14502 See [temp.class.order] for information about determining which of
14503 two templates is more specialized. */
14506 more_specialized_class (tree pat1, tree pat2)
14511 bool any_deductions = false;
14513 tmpl1 = TREE_TYPE (pat1);
14514 tmpl2 = TREE_TYPE (pat2);
14516 /* Just like what happens for functions, if we are ordering between
14517 different class template specializations, we may encounter dependent
14518 types in the arguments, and we need our dependency check functions
14519 to behave correctly. */
14520 ++processing_template_decl;
14521 targs = get_class_bindings (TREE_VALUE (pat1),
14522 CLASSTYPE_TI_ARGS (tmpl1),
14523 CLASSTYPE_TI_ARGS (tmpl2));
14527 any_deductions = true;
14530 targs = get_class_bindings (TREE_VALUE (pat2),
14531 CLASSTYPE_TI_ARGS (tmpl2),
14532 CLASSTYPE_TI_ARGS (tmpl1));
14536 any_deductions = true;
14538 --processing_template_decl;
14540 /* In the case of a tie where at least one of the class templates
14541 has a parameter pack at the end, the template with the most
14542 non-packed parameters wins. */
14545 && (template_args_variadic_p (TREE_PURPOSE (pat1))
14546 || template_args_variadic_p (TREE_PURPOSE (pat2))))
14548 tree args1 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat1));
14549 tree args2 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat2));
14550 int len1 = TREE_VEC_LENGTH (args1);
14551 int len2 = TREE_VEC_LENGTH (args2);
14553 /* We don't count the pack expansion at the end. */
14554 if (template_args_variadic_p (TREE_PURPOSE (pat1)))
14556 if (template_args_variadic_p (TREE_PURPOSE (pat2)))
14561 else if (len1 < len2)
14568 /* Return the template arguments that will produce the function signature
14569 DECL from the function template FN, with the explicit template
14570 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
14571 also match. Return NULL_TREE if no satisfactory arguments could be
14575 get_bindings (tree fn, tree decl, tree explicit_args, bool check_rettype)
14577 int ntparms = DECL_NTPARMS (fn);
14578 tree targs = make_tree_vec (ntparms);
14580 tree decl_arg_types;
14582 unsigned int nargs, ix;
14585 /* Substitute the explicit template arguments into the type of DECL.
14586 The call to fn_type_unification will handle substitution into the
14588 decl_type = TREE_TYPE (decl);
14589 if (explicit_args && uses_template_parms (decl_type))
14592 tree converted_args;
14594 if (DECL_TEMPLATE_INFO (decl))
14595 tmpl = DECL_TI_TEMPLATE (decl);
14597 /* We can get here for some invalid specializations. */
14601 = coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
14602 explicit_args, NULL_TREE,
14604 /*require_all_args=*/false,
14605 /*use_default_args=*/false);
14606 if (converted_args == error_mark_node)
14609 decl_type = tsubst (decl_type, converted_args, tf_none, NULL_TREE);
14610 if (decl_type == error_mark_node)
14614 /* Never do unification on the 'this' parameter. */
14615 decl_arg_types = skip_artificial_parms_for (decl,
14616 TYPE_ARG_TYPES (decl_type));
14618 nargs = list_length (decl_arg_types);
14619 args = XALLOCAVEC (tree, nargs);
14620 for (arg = decl_arg_types, ix = 0;
14621 arg != NULL_TREE && arg != void_list_node;
14622 arg = TREE_CHAIN (arg), ++ix)
14623 args[ix] = TREE_VALUE (arg);
14625 if (fn_type_unification (fn, explicit_args, targs,
14627 (check_rettype || DECL_CONV_FN_P (fn)
14628 ? TREE_TYPE (decl_type) : NULL_TREE),
14629 DEDUCE_EXACT, LOOKUP_NORMAL))
14635 /* Return the innermost template arguments that, when applied to a
14636 template specialization whose innermost template parameters are
14637 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
14640 For example, suppose we have:
14642 template <class T, class U> struct S {};
14643 template <class T> struct S<T*, int> {};
14645 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
14646 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
14647 int}. The resulting vector will be {double}, indicating that `T'
14648 is bound to `double'. */
14651 get_class_bindings (tree tparms, tree spec_args, tree args)
14653 int i, ntparms = TREE_VEC_LENGTH (tparms);
14655 tree innermost_deduced_args;
14657 innermost_deduced_args = make_tree_vec (ntparms);
14658 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
14660 deduced_args = copy_node (args);
14661 SET_TMPL_ARGS_LEVEL (deduced_args,
14662 TMPL_ARGS_DEPTH (deduced_args),
14663 innermost_deduced_args);
14666 deduced_args = innermost_deduced_args;
14668 if (unify (tparms, deduced_args,
14669 INNERMOST_TEMPLATE_ARGS (spec_args),
14670 INNERMOST_TEMPLATE_ARGS (args),
14674 for (i = 0; i < ntparms; ++i)
14675 if (! TREE_VEC_ELT (innermost_deduced_args, i))
14678 /* Verify that nondeduced template arguments agree with the type
14679 obtained from argument deduction.
14683 struct A { typedef int X; };
14684 template <class T, class U> struct C {};
14685 template <class T> struct C<T, typename T::X> {};
14687 Then with the instantiation `C<A, int>', we can deduce that
14688 `T' is `A' but unify () does not check whether `typename T::X'
14690 spec_args = tsubst (spec_args, deduced_args, tf_none, NULL_TREE);
14691 if (spec_args == error_mark_node
14692 /* We only need to check the innermost arguments; the other
14693 arguments will always agree. */
14694 || !comp_template_args (INNERMOST_TEMPLATE_ARGS (spec_args),
14695 INNERMOST_TEMPLATE_ARGS (args)))
14698 /* Now that we have bindings for all of the template arguments,
14699 ensure that the arguments deduced for the template template
14700 parameters have compatible template parameter lists. See the use
14701 of template_template_parm_bindings_ok_p in fn_type_unification
14702 for more information. */
14703 if (!template_template_parm_bindings_ok_p (tparms, deduced_args))
14706 return deduced_args;
14709 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
14710 Return the TREE_LIST node with the most specialized template, if
14711 any. If there is no most specialized template, the error_mark_node
14714 Note that this function does not look at, or modify, the
14715 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
14716 returned is one of the elements of INSTANTIATIONS, callers may
14717 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
14718 and retrieve it from the value returned. */
14721 most_specialized_instantiation (tree templates)
14725 ++processing_template_decl;
14728 for (fn = TREE_CHAIN (templates); fn; fn = TREE_CHAIN (fn))
14732 if (get_bindings (TREE_VALUE (champ),
14733 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
14734 NULL_TREE, /*check_ret=*/false))
14737 if (get_bindings (TREE_VALUE (fn),
14738 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
14739 NULL_TREE, /*check_ret=*/false))
14746 /* Equally specialized, move to next function. If there
14747 is no next function, nothing's most specialized. */
14748 fn = TREE_CHAIN (fn);
14756 /* Now verify that champ is better than everything earlier in the
14757 instantiation list. */
14758 for (fn = templates; fn != champ; fn = TREE_CHAIN (fn))
14759 if (get_bindings (TREE_VALUE (champ),
14760 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
14761 NULL_TREE, /*check_ret=*/false)
14762 || !get_bindings (TREE_VALUE (fn),
14763 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
14764 NULL_TREE, /*check_ret=*/false))
14770 processing_template_decl--;
14773 return error_mark_node;
14778 /* If DECL is a specialization of some template, return the most
14779 general such template. Otherwise, returns NULL_TREE.
14781 For example, given:
14783 template <class T> struct S { template <class U> void f(U); };
14785 if TMPL is `template <class U> void S<int>::f(U)' this will return
14786 the full template. This function will not trace past partial
14787 specializations, however. For example, given in addition:
14789 template <class T> struct S<T*> { template <class U> void f(U); };
14791 if TMPL is `template <class U> void S<int*>::f(U)' this will return
14792 `template <class T> template <class U> S<T*>::f(U)'. */
14795 most_general_template (tree decl)
14797 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
14798 an immediate specialization. */
14799 if (TREE_CODE (decl) == FUNCTION_DECL)
14801 if (DECL_TEMPLATE_INFO (decl)) {
14802 decl = DECL_TI_TEMPLATE (decl);
14804 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
14805 template friend. */
14806 if (TREE_CODE (decl) != TEMPLATE_DECL)
14812 /* Look for more and more general templates. */
14813 while (DECL_TEMPLATE_INFO (decl))
14815 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
14816 (See cp-tree.h for details.) */
14817 if (TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
14820 if (CLASS_TYPE_P (TREE_TYPE (decl))
14821 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)))
14824 /* Stop if we run into an explicitly specialized class template. */
14825 if (!DECL_NAMESPACE_SCOPE_P (decl)
14826 && DECL_CONTEXT (decl)
14827 && CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (decl)))
14830 decl = DECL_TI_TEMPLATE (decl);
14836 /* Return the most specialized of the class template partial
14837 specializations of TMPL which can produce TYPE, a specialization of
14838 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
14839 a _TYPE node corresponding to the partial specialization, while the
14840 TREE_PURPOSE is the set of template arguments that must be
14841 substituted into the TREE_TYPE in order to generate TYPE.
14843 If the choice of partial specialization is ambiguous, a diagnostic
14844 is issued, and the error_mark_node is returned. If there are no
14845 partial specializations of TMPL matching TYPE, then NULL_TREE is
14849 most_specialized_class (tree type, tree tmpl)
14851 tree list = NULL_TREE;
14857 tree outer_args = NULL_TREE;
14859 tmpl = most_general_template (tmpl);
14860 args = CLASSTYPE_TI_ARGS (type);
14862 /* For determining which partial specialization to use, only the
14863 innermost args are interesting. */
14864 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
14866 outer_args = strip_innermost_template_args (args, 1);
14867 args = INNERMOST_TEMPLATE_ARGS (args);
14870 for (t = DECL_TEMPLATE_SPECIALIZATIONS (tmpl); t; t = TREE_CHAIN (t))
14872 tree partial_spec_args;
14874 tree parms = TREE_VALUE (t);
14876 partial_spec_args = CLASSTYPE_TI_ARGS (TREE_TYPE (t));
14881 ++processing_template_decl;
14883 /* Discard the outer levels of args, and then substitute in the
14884 template args from the enclosing class. */
14885 partial_spec_args = INNERMOST_TEMPLATE_ARGS (partial_spec_args);
14886 partial_spec_args = tsubst_template_args
14887 (partial_spec_args, outer_args, tf_none, NULL_TREE);
14889 /* PARMS already refers to just the innermost parms, but the
14890 template parms in partial_spec_args had their levels lowered
14891 by tsubst, so we need to do the same for the parm list. We
14892 can't just tsubst the TREE_VEC itself, as tsubst wants to
14893 treat a TREE_VEC as an argument vector. */
14894 parms = copy_node (parms);
14895 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
14896 TREE_VEC_ELT (parms, i) =
14897 tsubst (TREE_VEC_ELT (parms, i), outer_args, tf_none, NULL_TREE);
14899 --processing_template_decl;
14901 spec_args = get_class_bindings (parms,
14907 spec_args = add_to_template_args (outer_args, spec_args);
14908 list = tree_cons (spec_args, TREE_VALUE (t), list);
14909 TREE_TYPE (list) = TREE_TYPE (t);
14916 ambiguous_p = false;
14919 t = TREE_CHAIN (t);
14920 for (; t; t = TREE_CHAIN (t))
14922 fate = more_specialized_class (champ, t);
14929 t = TREE_CHAIN (t);
14932 ambiguous_p = true;
14941 for (t = list; t && t != champ; t = TREE_CHAIN (t))
14943 fate = more_specialized_class (champ, t);
14946 ambiguous_p = true;
14953 const char *str = "candidates are:";
14954 error ("ambiguous class template instantiation for %q#T", type);
14955 for (t = list; t; t = TREE_CHAIN (t))
14957 error ("%s %+#T", str, TREE_TYPE (t));
14960 return error_mark_node;
14966 /* Explicitly instantiate DECL. */
14969 do_decl_instantiation (tree decl, tree storage)
14971 tree result = NULL_TREE;
14974 if (!decl || decl == error_mark_node)
14975 /* An error occurred, for which grokdeclarator has already issued
14976 an appropriate message. */
14978 else if (! DECL_LANG_SPECIFIC (decl))
14980 error ("explicit instantiation of non-template %q#D", decl);
14983 else if (TREE_CODE (decl) == VAR_DECL)
14985 /* There is an asymmetry here in the way VAR_DECLs and
14986 FUNCTION_DECLs are handled by grokdeclarator. In the case of
14987 the latter, the DECL we get back will be marked as a
14988 template instantiation, and the appropriate
14989 DECL_TEMPLATE_INFO will be set up. This does not happen for
14990 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
14991 should handle VAR_DECLs as it currently handles
14993 if (!DECL_CLASS_SCOPE_P (decl))
14995 error ("%qD is not a static data member of a class template", decl);
14998 result = lookup_field (DECL_CONTEXT (decl), DECL_NAME (decl), 0, false);
14999 if (!result || TREE_CODE (result) != VAR_DECL)
15001 error ("no matching template for %qD found", decl);
15004 if (!same_type_p (TREE_TYPE (result), TREE_TYPE (decl)))
15006 error ("type %qT for explicit instantiation %qD does not match "
15007 "declared type %qT", TREE_TYPE (result), decl,
15012 else if (TREE_CODE (decl) != FUNCTION_DECL)
15014 error ("explicit instantiation of %q#D", decl);
15020 /* Check for various error cases. Note that if the explicit
15021 instantiation is valid the RESULT will currently be marked as an
15022 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
15023 until we get here. */
15025 if (DECL_TEMPLATE_SPECIALIZATION (result))
15027 /* DR 259 [temp.spec].
15029 Both an explicit instantiation and a declaration of an explicit
15030 specialization shall not appear in a program unless the explicit
15031 instantiation follows a declaration of the explicit specialization.
15033 For a given set of template parameters, if an explicit
15034 instantiation of a template appears after a declaration of an
15035 explicit specialization for that template, the explicit
15036 instantiation has no effect. */
15039 else if (DECL_EXPLICIT_INSTANTIATION (result))
15043 No program shall explicitly instantiate any template more
15046 We check DECL_NOT_REALLY_EXTERN so as not to complain when
15047 the first instantiation was `extern' and the second is not,
15048 and EXTERN_P for the opposite case. */
15049 if (DECL_NOT_REALLY_EXTERN (result) && !extern_p)
15050 permerror (input_location, "duplicate explicit instantiation of %q#D", result);
15051 /* If an "extern" explicit instantiation follows an ordinary
15052 explicit instantiation, the template is instantiated. */
15056 else if (!DECL_IMPLICIT_INSTANTIATION (result))
15058 error ("no matching template for %qD found", result);
15061 else if (!DECL_TEMPLATE_INFO (result))
15063 permerror (input_location, "explicit instantiation of non-template %q#D", result);
15067 if (storage == NULL_TREE)
15069 else if (storage == ridpointers[(int) RID_EXTERN])
15071 if (!in_system_header && (cxx_dialect == cxx98))
15072 pedwarn (input_location, OPT_pedantic,
15073 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
15078 error ("storage class %qD applied to template instantiation", storage);
15080 check_explicit_instantiation_namespace (result);
15081 mark_decl_instantiated (result, extern_p);
15083 instantiate_decl (result, /*defer_ok=*/1,
15084 /*expl_inst_class_mem_p=*/false);
15088 mark_class_instantiated (tree t, int extern_p)
15090 SET_CLASSTYPE_EXPLICIT_INSTANTIATION (t);
15091 SET_CLASSTYPE_INTERFACE_KNOWN (t);
15092 CLASSTYPE_INTERFACE_ONLY (t) = extern_p;
15093 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (t)) = extern_p;
15096 CLASSTYPE_DEBUG_REQUESTED (t) = 1;
15097 rest_of_type_compilation (t, 1);
15101 /* Called from do_type_instantiation through binding_table_foreach to
15102 do recursive instantiation for the type bound in ENTRY. */
15104 bt_instantiate_type_proc (binding_entry entry, void *data)
15106 tree storage = *(tree *) data;
15108 if (MAYBE_CLASS_TYPE_P (entry->type)
15109 && !uses_template_parms (CLASSTYPE_TI_ARGS (entry->type)))
15110 do_type_instantiation (TYPE_MAIN_DECL (entry->type), storage, 0);
15113 /* Called from do_type_instantiation to instantiate a member
15114 (a member function or a static member variable) of an
15115 explicitly instantiated class template. */
15117 instantiate_class_member (tree decl, int extern_p)
15119 mark_decl_instantiated (decl, extern_p);
15121 instantiate_decl (decl, /*defer_ok=*/1,
15122 /*expl_inst_class_mem_p=*/true);
15125 /* Perform an explicit instantiation of template class T. STORAGE, if
15126 non-null, is the RID for extern, inline or static. COMPLAIN is
15127 nonzero if this is called from the parser, zero if called recursively,
15128 since the standard is unclear (as detailed below). */
15131 do_type_instantiation (tree t, tree storage, tsubst_flags_t complain)
15136 int previous_instantiation_extern_p = 0;
15138 if (TREE_CODE (t) == TYPE_DECL)
15141 if (! CLASS_TYPE_P (t) || ! CLASSTYPE_TEMPLATE_INFO (t))
15143 error ("explicit instantiation of non-template type %qT", t);
15149 if (!COMPLETE_TYPE_P (t))
15151 if (complain & tf_error)
15152 error ("explicit instantiation of %q#T before definition of template",
15157 if (storage != NULL_TREE)
15159 if (!in_system_header)
15161 if (storage == ridpointers[(int) RID_EXTERN])
15163 if (cxx_dialect == cxx98)
15164 pedwarn (input_location, OPT_pedantic,
15165 "ISO C++ 1998 forbids the use of %<extern%> on "
15166 "explicit instantiations");
15169 pedwarn (input_location, OPT_pedantic,
15170 "ISO C++ forbids the use of %qE"
15171 " on explicit instantiations", storage);
15174 if (storage == ridpointers[(int) RID_INLINE])
15176 else if (storage == ridpointers[(int) RID_EXTERN])
15178 else if (storage == ridpointers[(int) RID_STATIC])
15182 error ("storage class %qD applied to template instantiation",
15188 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (t))
15190 /* DR 259 [temp.spec].
15192 Both an explicit instantiation and a declaration of an explicit
15193 specialization shall not appear in a program unless the explicit
15194 instantiation follows a declaration of the explicit specialization.
15196 For a given set of template parameters, if an explicit
15197 instantiation of a template appears after a declaration of an
15198 explicit specialization for that template, the explicit
15199 instantiation has no effect. */
15202 else if (CLASSTYPE_EXPLICIT_INSTANTIATION (t))
15206 No program shall explicitly instantiate any template more
15209 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
15210 instantiation was `extern'. If EXTERN_P then the second is.
15211 These cases are OK. */
15212 previous_instantiation_extern_p = CLASSTYPE_INTERFACE_ONLY (t);
15214 if (!previous_instantiation_extern_p && !extern_p
15215 && (complain & tf_error))
15216 permerror (input_location, "duplicate explicit instantiation of %q#T", t);
15218 /* If we've already instantiated the template, just return now. */
15219 if (!CLASSTYPE_INTERFACE_ONLY (t))
15223 check_explicit_instantiation_namespace (TYPE_NAME (t));
15224 mark_class_instantiated (t, extern_p);
15232 /* In contrast to implicit instantiation, where only the
15233 declarations, and not the definitions, of members are
15234 instantiated, we have here:
15238 The explicit instantiation of a class template specialization
15239 implies the instantiation of all of its members not
15240 previously explicitly specialized in the translation unit
15241 containing the explicit instantiation.
15243 Of course, we can't instantiate member template classes, since
15244 we don't have any arguments for them. Note that the standard
15245 is unclear on whether the instantiation of the members are
15246 *explicit* instantiations or not. However, the most natural
15247 interpretation is that it should be an explicit instantiation. */
15250 for (tmp = TYPE_METHODS (t); tmp; tmp = TREE_CHAIN (tmp))
15251 if (TREE_CODE (tmp) == FUNCTION_DECL
15252 && DECL_TEMPLATE_INSTANTIATION (tmp))
15253 instantiate_class_member (tmp, extern_p);
15255 for (tmp = TYPE_FIELDS (t); tmp; tmp = TREE_CHAIN (tmp))
15256 if (TREE_CODE (tmp) == VAR_DECL && DECL_TEMPLATE_INSTANTIATION (tmp))
15257 instantiate_class_member (tmp, extern_p);
15259 if (CLASSTYPE_NESTED_UTDS (t))
15260 binding_table_foreach (CLASSTYPE_NESTED_UTDS (t),
15261 bt_instantiate_type_proc, &storage);
15265 /* Given a function DECL, which is a specialization of TMPL, modify
15266 DECL to be a re-instantiation of TMPL with the same template
15267 arguments. TMPL should be the template into which tsubst'ing
15268 should occur for DECL, not the most general template.
15270 One reason for doing this is a scenario like this:
15273 void f(const T&, int i);
15275 void g() { f(3, 7); }
15278 void f(const T& t, const int i) { }
15280 Note that when the template is first instantiated, with
15281 instantiate_template, the resulting DECL will have no name for the
15282 first parameter, and the wrong type for the second. So, when we go
15283 to instantiate the DECL, we regenerate it. */
15286 regenerate_decl_from_template (tree decl, tree tmpl)
15288 /* The arguments used to instantiate DECL, from the most general
15293 args = DECL_TI_ARGS (decl);
15294 code_pattern = DECL_TEMPLATE_RESULT (tmpl);
15296 /* Make sure that we can see identifiers, and compute access
15298 push_access_scope (decl);
15300 if (TREE_CODE (decl) == FUNCTION_DECL)
15308 args_depth = TMPL_ARGS_DEPTH (args);
15309 parms_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
15310 if (args_depth > parms_depth)
15311 args = get_innermost_template_args (args, parms_depth);
15313 specs = tsubst_exception_specification (TREE_TYPE (code_pattern),
15314 args, tf_error, NULL_TREE);
15316 TREE_TYPE (decl) = build_exception_variant (TREE_TYPE (decl),
15319 /* Merge parameter declarations. */
15320 decl_parm = skip_artificial_parms_for (decl,
15321 DECL_ARGUMENTS (decl));
15323 = skip_artificial_parms_for (code_pattern,
15324 DECL_ARGUMENTS (code_pattern));
15325 while (decl_parm && !FUNCTION_PARAMETER_PACK_P (pattern_parm))
15330 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
15331 DECL_NAME (decl_parm) = DECL_NAME (pattern_parm);
15332 parm_type = tsubst (TREE_TYPE (pattern_parm), args, tf_error,
15334 parm_type = type_decays_to (parm_type);
15335 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
15336 TREE_TYPE (decl_parm) = parm_type;
15337 attributes = DECL_ATTRIBUTES (pattern_parm);
15338 if (DECL_ATTRIBUTES (decl_parm) != attributes)
15340 DECL_ATTRIBUTES (decl_parm) = attributes;
15341 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
15343 decl_parm = TREE_CHAIN (decl_parm);
15344 pattern_parm = TREE_CHAIN (pattern_parm);
15346 /* Merge any parameters that match with the function parameter
15348 if (pattern_parm && FUNCTION_PARAMETER_PACK_P (pattern_parm))
15351 tree expanded_types;
15352 /* Expand the TYPE_PACK_EXPANSION that provides the types for
15353 the parameters in this function parameter pack. */
15354 expanded_types = tsubst_pack_expansion (TREE_TYPE (pattern_parm),
15355 args, tf_error, NULL_TREE);
15356 len = TREE_VEC_LENGTH (expanded_types);
15357 for (i = 0; i < len; i++)
15362 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
15363 /* Rename the parameter to include the index. */
15364 DECL_NAME (decl_parm) =
15365 make_ith_pack_parameter_name (DECL_NAME (pattern_parm), i);
15366 parm_type = TREE_VEC_ELT (expanded_types, i);
15367 parm_type = type_decays_to (parm_type);
15368 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
15369 TREE_TYPE (decl_parm) = parm_type;
15370 attributes = DECL_ATTRIBUTES (pattern_parm);
15371 if (DECL_ATTRIBUTES (decl_parm) != attributes)
15373 DECL_ATTRIBUTES (decl_parm) = attributes;
15374 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
15376 decl_parm = TREE_CHAIN (decl_parm);
15379 /* Merge additional specifiers from the CODE_PATTERN. */
15380 if (DECL_DECLARED_INLINE_P (code_pattern)
15381 && !DECL_DECLARED_INLINE_P (decl))
15382 DECL_DECLARED_INLINE_P (decl) = 1;
15384 else if (TREE_CODE (decl) == VAR_DECL)
15385 DECL_INITIAL (decl) =
15386 tsubst_expr (DECL_INITIAL (code_pattern), args,
15387 tf_error, DECL_TI_TEMPLATE (decl),
15388 /*integral_constant_expression_p=*/false);
15390 gcc_unreachable ();
15392 pop_access_scope (decl);
15395 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
15396 substituted to get DECL. */
15399 template_for_substitution (tree decl)
15401 tree tmpl = DECL_TI_TEMPLATE (decl);
15403 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
15404 for the instantiation. This is not always the most general
15405 template. Consider, for example:
15408 struct S { template <class U> void f();
15409 template <> void f<int>(); };
15411 and an instantiation of S<double>::f<int>. We want TD to be the
15412 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
15413 while (/* An instantiation cannot have a definition, so we need a
15414 more general template. */
15415 DECL_TEMPLATE_INSTANTIATION (tmpl)
15416 /* We must also deal with friend templates. Given:
15418 template <class T> struct S {
15419 template <class U> friend void f() {};
15422 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
15423 so far as the language is concerned, but that's still
15424 where we get the pattern for the instantiation from. On
15425 other hand, if the definition comes outside the class, say:
15427 template <class T> struct S {
15428 template <class U> friend void f();
15430 template <class U> friend void f() {}
15432 we don't need to look any further. That's what the check for
15433 DECL_INITIAL is for. */
15434 || (TREE_CODE (decl) == FUNCTION_DECL
15435 && DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION (tmpl)
15436 && !DECL_INITIAL (DECL_TEMPLATE_RESULT (tmpl))))
15438 /* The present template, TD, should not be a definition. If it
15439 were a definition, we should be using it! Note that we
15440 cannot restructure the loop to just keep going until we find
15441 a template with a definition, since that might go too far if
15442 a specialization was declared, but not defined. */
15443 gcc_assert (TREE_CODE (decl) != VAR_DECL
15444 || DECL_IN_AGGR_P (DECL_TEMPLATE_RESULT (tmpl)));
15446 /* Fetch the more general template. */
15447 tmpl = DECL_TI_TEMPLATE (tmpl);
15453 /* Produce the definition of D, a _DECL generated from a template. If
15454 DEFER_OK is nonzero, then we don't have to actually do the
15455 instantiation now; we just have to do it sometime. Normally it is
15456 an error if this is an explicit instantiation but D is undefined.
15457 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
15458 explicitly instantiated class template. */
15461 instantiate_decl (tree d, int defer_ok,
15462 bool expl_inst_class_mem_p)
15464 tree tmpl = DECL_TI_TEMPLATE (d);
15471 bool pattern_defined;
15473 location_t saved_loc = input_location;
15476 /* This function should only be used to instantiate templates for
15477 functions and static member variables. */
15478 gcc_assert (TREE_CODE (d) == FUNCTION_DECL
15479 || TREE_CODE (d) == VAR_DECL);
15481 /* Variables are never deferred; if instantiation is required, they
15482 are instantiated right away. That allows for better code in the
15483 case that an expression refers to the value of the variable --
15484 if the variable has a constant value the referring expression can
15485 take advantage of that fact. */
15486 if (TREE_CODE (d) == VAR_DECL)
15489 /* Don't instantiate cloned functions. Instead, instantiate the
15490 functions they cloned. */
15491 if (TREE_CODE (d) == FUNCTION_DECL && DECL_CLONED_FUNCTION_P (d))
15492 d = DECL_CLONED_FUNCTION (d);
15494 if (DECL_TEMPLATE_INSTANTIATED (d))
15495 /* D has already been instantiated. It might seem reasonable to
15496 check whether or not D is an explicit instantiation, and, if so,
15497 stop here. But when an explicit instantiation is deferred
15498 until the end of the compilation, DECL_EXPLICIT_INSTANTIATION
15499 is set, even though we still need to do the instantiation. */
15502 /* If we already have a specialization of this declaration, then
15503 there's no reason to instantiate it. Note that
15504 retrieve_specialization gives us both instantiations and
15505 specializations, so we must explicitly check
15506 DECL_TEMPLATE_SPECIALIZATION. */
15507 gen_tmpl = most_general_template (tmpl);
15508 gen_args = DECL_TI_ARGS (d);
15509 spec = retrieve_specialization (gen_tmpl, gen_args,
15510 /*class_specializations_p=*/false);
15511 if (spec != NULL_TREE && DECL_TEMPLATE_SPECIALIZATION (spec))
15514 /* This needs to happen before any tsubsting. */
15515 if (! push_tinst_level (d))
15518 timevar_push (TV_PARSE);
15520 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
15521 for the instantiation. */
15522 td = template_for_substitution (d);
15523 code_pattern = DECL_TEMPLATE_RESULT (td);
15525 /* We should never be trying to instantiate a member of a class
15526 template or partial specialization. */
15527 gcc_assert (d != code_pattern);
15529 if ((DECL_NAMESPACE_SCOPE_P (d) && !DECL_INITIALIZED_IN_CLASS_P (d))
15530 || DECL_TEMPLATE_SPECIALIZATION (td))
15531 /* In the case of a friend template whose definition is provided
15532 outside the class, we may have too many arguments. Drop the
15533 ones we don't need. The same is true for specializations. */
15534 args = get_innermost_template_args
15535 (gen_args, TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (td)));
15539 if (TREE_CODE (d) == FUNCTION_DECL)
15540 pattern_defined = (DECL_SAVED_TREE (code_pattern) != NULL_TREE);
15542 pattern_defined = ! DECL_IN_AGGR_P (code_pattern);
15544 /* We may be in the middle of deferred access check. Disable it now. */
15545 push_deferring_access_checks (dk_no_deferred);
15547 /* Unless an explicit instantiation directive has already determined
15548 the linkage of D, remember that a definition is available for
15550 if (pattern_defined
15551 && !DECL_INTERFACE_KNOWN (d)
15552 && !DECL_NOT_REALLY_EXTERN (d))
15553 mark_definable (d);
15555 input_location = DECL_SOURCE_LOCATION (d);
15557 /* If D is a member of an explicitly instantiated class template,
15558 and no definition is available, treat it like an implicit
15560 if (!pattern_defined && expl_inst_class_mem_p
15561 && DECL_EXPLICIT_INSTANTIATION (d))
15563 DECL_NOT_REALLY_EXTERN (d) = 0;
15564 DECL_INTERFACE_KNOWN (d) = 0;
15565 SET_DECL_IMPLICIT_INSTANTIATION (d);
15570 /* Recheck the substitutions to obtain any warning messages
15571 about ignoring cv qualifiers. */
15572 tree gen = DECL_TEMPLATE_RESULT (gen_tmpl);
15573 tree type = TREE_TYPE (gen);
15575 /* Make sure that we can see identifiers, and compute access
15576 correctly. D is already the target FUNCTION_DECL with the
15578 push_access_scope (d);
15580 if (TREE_CODE (gen) == FUNCTION_DECL)
15582 tsubst (DECL_ARGUMENTS (gen), gen_args, tf_warning_or_error, d);
15583 tsubst_exception_specification (type, gen_args, tf_warning_or_error,
15585 /* Don't simply tsubst the function type, as that will give
15586 duplicate warnings about poor parameter qualifications.
15587 The function arguments are the same as the decl_arguments
15588 without the top level cv qualifiers. */
15589 type = TREE_TYPE (type);
15591 tsubst (type, gen_args, tf_warning_or_error, d);
15593 pop_access_scope (d);
15596 /* Check to see whether we know that this template will be
15597 instantiated in some other file, as with "extern template"
15599 external_p = (DECL_INTERFACE_KNOWN (d) && DECL_REALLY_EXTERN (d));
15600 /* In general, we do not instantiate such templates... */
15602 /* ... but we instantiate inline functions so that we can inline
15603 them. An explicit instantiation declaration prohibits implicit
15604 instantiation of non-inline functions. With high levels of
15605 optimization, we would normally inline non-inline functions
15606 -- but we're not allowed to do that for "extern template" functions.
15607 Therefore, we check DECL_DECLARED_INLINE_P, rather than
15608 possibly_inlined_p. And ... */
15609 && ! (TREE_CODE (d) == FUNCTION_DECL
15610 && DECL_DECLARED_INLINE_P (d))
15611 /* ... we instantiate static data members whose values are
15612 needed in integral constant expressions. */
15613 && ! (TREE_CODE (d) == VAR_DECL
15614 && DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (d)))
15616 /* Defer all other templates, unless we have been explicitly
15617 forbidden from doing so. */
15618 if (/* If there is no definition, we cannot instantiate the
15621 /* If it's OK to postpone instantiation, do so. */
15623 /* If this is a static data member that will be defined
15624 elsewhere, we don't want to instantiate the entire data
15625 member, but we do want to instantiate the initializer so that
15626 we can substitute that elsewhere. */
15627 || (external_p && TREE_CODE (d) == VAR_DECL))
15629 /* The definition of the static data member is now required so
15630 we must substitute the initializer. */
15631 if (TREE_CODE (d) == VAR_DECL
15632 && !DECL_INITIAL (d)
15633 && DECL_INITIAL (code_pattern))
15638 ns = decl_namespace_context (d);
15639 push_nested_namespace (ns);
15640 push_nested_class (DECL_CONTEXT (d));
15641 init = tsubst_expr (DECL_INITIAL (code_pattern),
15643 tf_warning_or_error, NULL_TREE,
15644 /*integral_constant_expression_p=*/false);
15645 cp_finish_decl (d, init, /*init_const_expr_p=*/false,
15646 /*asmspec_tree=*/NULL_TREE,
15647 LOOKUP_ONLYCONVERTING);
15648 pop_nested_class ();
15649 pop_nested_namespace (ns);
15652 /* We restore the source position here because it's used by
15653 add_pending_template. */
15654 input_location = saved_loc;
15656 if (at_eof && !pattern_defined
15657 && DECL_EXPLICIT_INSTANTIATION (d)
15658 && DECL_NOT_REALLY_EXTERN (d))
15661 The definition of a non-exported function template, a
15662 non-exported member function template, or a non-exported
15663 member function or static data member of a class template
15664 shall be present in every translation unit in which it is
15665 explicitly instantiated. */
15666 permerror (input_location, "explicit instantiation of %qD "
15667 "but no definition available", d);
15669 /* ??? Historically, we have instantiated inline functions, even
15670 when marked as "extern template". */
15671 if (!(external_p && TREE_CODE (d) == VAR_DECL))
15672 add_pending_template (d);
15675 /* Tell the repository that D is available in this translation unit
15676 -- and see if it is supposed to be instantiated here. */
15677 if (TREE_PUBLIC (d) && !DECL_REALLY_EXTERN (d) && !repo_emit_p (d))
15679 /* In a PCH file, despite the fact that the repository hasn't
15680 requested instantiation in the PCH it is still possible that
15681 an instantiation will be required in a file that includes the
15684 add_pending_template (d);
15685 /* Instantiate inline functions so that the inliner can do its
15686 job, even though we'll not be emitting a copy of this
15688 if (!(TREE_CODE (d) == FUNCTION_DECL && possibly_inlined_p (d)))
15692 need_push = !cfun || !global_bindings_p ();
15694 push_to_top_level ();
15696 /* Mark D as instantiated so that recursive calls to
15697 instantiate_decl do not try to instantiate it again. */
15698 DECL_TEMPLATE_INSTANTIATED (d) = 1;
15700 /* Regenerate the declaration in case the template has been modified
15701 by a subsequent redeclaration. */
15702 regenerate_decl_from_template (d, td);
15704 /* We already set the file and line above. Reset them now in case
15705 they changed as a result of calling regenerate_decl_from_template. */
15706 input_location = DECL_SOURCE_LOCATION (d);
15708 if (TREE_CODE (d) == VAR_DECL)
15712 /* Clear out DECL_RTL; whatever was there before may not be right
15713 since we've reset the type of the declaration. */
15714 SET_DECL_RTL (d, NULL_RTX);
15715 DECL_IN_AGGR_P (d) = 0;
15717 /* The initializer is placed in DECL_INITIAL by
15718 regenerate_decl_from_template. Pull it out so that
15719 cp_finish_decl can process it. */
15720 init = DECL_INITIAL (d);
15721 DECL_INITIAL (d) = NULL_TREE;
15722 DECL_INITIALIZED_P (d) = 0;
15724 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
15725 initializer. That function will defer actual emission until
15726 we have a chance to determine linkage. */
15727 DECL_EXTERNAL (d) = 0;
15729 /* Enter the scope of D so that access-checking works correctly. */
15730 push_nested_class (DECL_CONTEXT (d));
15731 cp_finish_decl (d, init, false, NULL_TREE, 0);
15732 pop_nested_class ();
15734 else if (TREE_CODE (d) == FUNCTION_DECL)
15736 htab_t saved_local_specializations;
15741 /* Save away the current list, in case we are instantiating one
15742 template from within the body of another. */
15743 saved_local_specializations = local_specializations;
15745 /* Set up the list of local specializations. */
15746 local_specializations = htab_create (37,
15747 hash_local_specialization,
15748 eq_local_specializations,
15751 /* Set up context. */
15752 start_preparsed_function (d, NULL_TREE, SF_PRE_PARSED);
15754 /* Create substitution entries for the parameters. */
15755 subst_decl = DECL_TEMPLATE_RESULT (template_for_substitution (d));
15756 tmpl_parm = DECL_ARGUMENTS (subst_decl);
15757 spec_parm = DECL_ARGUMENTS (d);
15758 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (d))
15760 register_local_specialization (spec_parm, tmpl_parm);
15761 spec_parm = skip_artificial_parms_for (d, spec_parm);
15762 tmpl_parm = skip_artificial_parms_for (subst_decl, tmpl_parm);
15764 while (tmpl_parm && !FUNCTION_PARAMETER_PACK_P (tmpl_parm))
15766 register_local_specialization (spec_parm, tmpl_parm);
15767 tmpl_parm = TREE_CHAIN (tmpl_parm);
15768 spec_parm = TREE_CHAIN (spec_parm);
15770 if (tmpl_parm && FUNCTION_PARAMETER_PACK_P (tmpl_parm))
15772 /* Register the (value) argument pack as a specialization of
15773 TMPL_PARM, then move on. */
15774 tree argpack = make_fnparm_pack (spec_parm);
15775 register_local_specialization (argpack, tmpl_parm);
15776 tmpl_parm = TREE_CHAIN (tmpl_parm);
15777 spec_parm = NULL_TREE;
15779 gcc_assert (!spec_parm);
15781 /* Substitute into the body of the function. */
15782 tsubst_expr (DECL_SAVED_TREE (code_pattern), args,
15783 tf_warning_or_error, tmpl,
15784 /*integral_constant_expression_p=*/false);
15786 /* Set the current input_location to the end of the function
15787 so that finish_function knows where we are. */
15788 input_location = DECL_STRUCT_FUNCTION (code_pattern)->function_end_locus;
15790 /* We don't need the local specializations any more. */
15791 htab_delete (local_specializations);
15792 local_specializations = saved_local_specializations;
15794 /* Finish the function. */
15795 d = finish_function (0);
15796 expand_or_defer_fn (d);
15799 /* We're not deferring instantiation any more. */
15800 TI_PENDING_TEMPLATE_FLAG (DECL_TEMPLATE_INFO (d)) = 0;
15803 pop_from_top_level ();
15806 input_location = saved_loc;
15807 pop_deferring_access_checks ();
15808 pop_tinst_level ();
15810 timevar_pop (TV_PARSE);
15815 /* Run through the list of templates that we wish we could
15816 instantiate, and instantiate any we can. RETRIES is the
15817 number of times we retry pending template instantiation. */
15820 instantiate_pending_templates (int retries)
15823 location_t saved_loc = input_location;
15825 /* Instantiating templates may trigger vtable generation. This in turn
15826 may require further template instantiations. We place a limit here
15827 to avoid infinite loop. */
15828 if (pending_templates && retries >= max_tinst_depth)
15830 tree decl = pending_templates->tinst->decl;
15832 error ("template instantiation depth exceeds maximum of %d"
15833 " instantiating %q+D, possibly from virtual table generation"
15834 " (use -ftemplate-depth-NN to increase the maximum)",
15835 max_tinst_depth, decl);
15836 if (TREE_CODE (decl) == FUNCTION_DECL)
15837 /* Pretend that we defined it. */
15838 DECL_INITIAL (decl) = error_mark_node;
15844 struct pending_template **t = &pending_templates;
15845 struct pending_template *last = NULL;
15849 tree instantiation = reopen_tinst_level ((*t)->tinst);
15850 bool complete = false;
15852 if (TYPE_P (instantiation))
15856 if (!COMPLETE_TYPE_P (instantiation))
15858 instantiate_class_template (instantiation);
15859 if (CLASSTYPE_TEMPLATE_INSTANTIATION (instantiation))
15860 for (fn = TYPE_METHODS (instantiation);
15862 fn = TREE_CHAIN (fn))
15863 if (! DECL_ARTIFICIAL (fn))
15864 instantiate_decl (fn,
15866 /*expl_inst_class_mem_p=*/false);
15867 if (COMPLETE_TYPE_P (instantiation))
15871 complete = COMPLETE_TYPE_P (instantiation);
15875 if (!DECL_TEMPLATE_SPECIALIZATION (instantiation)
15876 && !DECL_TEMPLATE_INSTANTIATED (instantiation))
15879 = instantiate_decl (instantiation,
15881 /*expl_inst_class_mem_p=*/false);
15882 if (DECL_TEMPLATE_INSTANTIATED (instantiation))
15886 complete = (DECL_TEMPLATE_SPECIALIZATION (instantiation)
15887 || DECL_TEMPLATE_INSTANTIATED (instantiation));
15891 /* If INSTANTIATION has been instantiated, then we don't
15892 need to consider it again in the future. */
15900 current_tinst_level = NULL;
15902 last_pending_template = last;
15904 while (reconsider);
15906 input_location = saved_loc;
15909 /* Substitute ARGVEC into T, which is a list of initializers for
15910 either base class or a non-static data member. The TREE_PURPOSEs
15911 are DECLs, and the TREE_VALUEs are the initializer values. Used by
15912 instantiate_decl. */
15915 tsubst_initializer_list (tree t, tree argvec)
15917 tree inits = NULL_TREE;
15919 for (; t; t = TREE_CHAIN (t))
15923 tree expanded_bases = NULL_TREE;
15924 tree expanded_arguments = NULL_TREE;
15927 if (TREE_CODE (TREE_PURPOSE (t)) == TYPE_PACK_EXPANSION)
15932 /* Expand the base class expansion type into separate base
15934 expanded_bases = tsubst_pack_expansion (TREE_PURPOSE (t), argvec,
15935 tf_warning_or_error,
15937 if (expanded_bases == error_mark_node)
15940 /* We'll be building separate TREE_LISTs of arguments for
15942 len = TREE_VEC_LENGTH (expanded_bases);
15943 expanded_arguments = make_tree_vec (len);
15944 for (i = 0; i < len; i++)
15945 TREE_VEC_ELT (expanded_arguments, i) = NULL_TREE;
15947 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
15948 expand each argument in the TREE_VALUE of t. */
15949 expr = make_node (EXPR_PACK_EXPANSION);
15950 PACK_EXPANSION_PARAMETER_PACKS (expr) =
15951 PACK_EXPANSION_PARAMETER_PACKS (TREE_PURPOSE (t));
15953 if (TREE_VALUE (t) == void_type_node)
15954 /* VOID_TYPE_NODE is used to indicate
15955 value-initialization. */
15957 for (i = 0; i < len; i++)
15958 TREE_VEC_ELT (expanded_arguments, i) = void_type_node;
15962 /* Substitute parameter packs into each argument in the
15964 in_base_initializer = 1;
15965 for (arg = TREE_VALUE (t); arg; arg = TREE_CHAIN (arg))
15967 tree expanded_exprs;
15969 /* Expand the argument. */
15970 SET_PACK_EXPANSION_PATTERN (expr, TREE_VALUE (arg));
15972 = tsubst_pack_expansion (expr, argvec,
15973 tf_warning_or_error,
15975 if (expanded_exprs == error_mark_node)
15978 /* Prepend each of the expanded expressions to the
15979 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
15980 for (i = 0; i < len; i++)
15982 TREE_VEC_ELT (expanded_arguments, i) =
15983 tree_cons (NULL_TREE,
15984 TREE_VEC_ELT (expanded_exprs, i),
15985 TREE_VEC_ELT (expanded_arguments, i));
15988 in_base_initializer = 0;
15990 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
15991 since we built them backwards. */
15992 for (i = 0; i < len; i++)
15994 TREE_VEC_ELT (expanded_arguments, i) =
15995 nreverse (TREE_VEC_ELT (expanded_arguments, i));
16000 for (i = 0; i < len; ++i)
16002 if (expanded_bases)
16004 decl = TREE_VEC_ELT (expanded_bases, i);
16005 decl = expand_member_init (decl);
16006 init = TREE_VEC_ELT (expanded_arguments, i);
16010 decl = tsubst_copy (TREE_PURPOSE (t), argvec,
16011 tf_warning_or_error, NULL_TREE);
16013 decl = expand_member_init (decl);
16014 if (decl && !DECL_P (decl))
16015 in_base_initializer = 1;
16017 init = tsubst_expr (TREE_VALUE (t), argvec,
16018 tf_warning_or_error, NULL_TREE,
16019 /*integral_constant_expression_p=*/false);
16020 in_base_initializer = 0;
16025 init = build_tree_list (decl, init);
16026 TREE_CHAIN (init) = inits;
16034 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
16037 set_current_access_from_decl (tree decl)
16039 if (TREE_PRIVATE (decl))
16040 current_access_specifier = access_private_node;
16041 else if (TREE_PROTECTED (decl))
16042 current_access_specifier = access_protected_node;
16044 current_access_specifier = access_public_node;
16047 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
16048 is the instantiation (which should have been created with
16049 start_enum) and ARGS are the template arguments to use. */
16052 tsubst_enum (tree tag, tree newtag, tree args)
16056 for (e = TYPE_VALUES (tag); e; e = TREE_CHAIN (e))
16061 decl = TREE_VALUE (e);
16062 /* Note that in a template enum, the TREE_VALUE is the
16063 CONST_DECL, not the corresponding INTEGER_CST. */
16064 value = tsubst_expr (DECL_INITIAL (decl),
16065 args, tf_warning_or_error, NULL_TREE,
16066 /*integral_constant_expression_p=*/true);
16068 /* Give this enumeration constant the correct access. */
16069 set_current_access_from_decl (decl);
16071 /* Actually build the enumerator itself. */
16072 build_enumerator (DECL_NAME (decl), value, newtag);
16075 finish_enum (newtag);
16076 DECL_SOURCE_LOCATION (TYPE_NAME (newtag))
16077 = DECL_SOURCE_LOCATION (TYPE_NAME (tag));
16080 /* DECL is a FUNCTION_DECL that is a template specialization. Return
16081 its type -- but without substituting the innermost set of template
16082 arguments. So, innermost set of template parameters will appear in
16086 get_mostly_instantiated_function_type (tree decl)
16094 tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
16095 targs = DECL_TI_ARGS (decl);
16096 tparms = DECL_TEMPLATE_PARMS (tmpl);
16097 parm_depth = TMPL_PARMS_DEPTH (tparms);
16099 /* There should be as many levels of arguments as there are levels
16101 gcc_assert (parm_depth == TMPL_ARGS_DEPTH (targs));
16103 fn_type = TREE_TYPE (tmpl);
16105 if (parm_depth == 1)
16106 /* No substitution is necessary. */
16110 int i, save_access_control;
16113 /* Replace the innermost level of the TARGS with NULL_TREEs to
16114 let tsubst know not to substitute for those parameters. */
16115 partial_args = make_tree_vec (TREE_VEC_LENGTH (targs));
16116 for (i = 1; i < TMPL_ARGS_DEPTH (targs); ++i)
16117 SET_TMPL_ARGS_LEVEL (partial_args, i,
16118 TMPL_ARGS_LEVEL (targs, i));
16119 SET_TMPL_ARGS_LEVEL (partial_args,
16120 TMPL_ARGS_DEPTH (targs),
16121 make_tree_vec (DECL_NTPARMS (tmpl)));
16123 /* Disable access control as this function is used only during
16125 save_access_control = flag_access_control;
16126 flag_access_control = 0;
16128 ++processing_template_decl;
16129 /* Now, do the (partial) substitution to figure out the
16130 appropriate function type. */
16131 fn_type = tsubst (fn_type, partial_args, tf_error, NULL_TREE);
16132 --processing_template_decl;
16134 /* Substitute into the template parameters to obtain the real
16135 innermost set of parameters. This step is important if the
16136 innermost set of template parameters contains value
16137 parameters whose types depend on outer template parameters. */
16138 TREE_VEC_LENGTH (partial_args)--;
16139 tparms = tsubst_template_parms (tparms, partial_args, tf_error);
16141 flag_access_control = save_access_control;
16147 /* Return truthvalue if we're processing a template different from
16148 the last one involved in diagnostics. */
16150 problematic_instantiation_changed (void)
16152 return last_template_error_tick != tinst_level_tick;
16155 /* Remember current template involved in diagnostics. */
16157 record_last_problematic_instantiation (void)
16159 last_template_error_tick = tinst_level_tick;
16162 struct tinst_level *
16163 current_instantiation (void)
16165 return current_tinst_level;
16168 /* [temp.param] Check that template non-type parm TYPE is of an allowable
16169 type. Return zero for ok, nonzero for disallowed. Issue error and
16170 warning messages under control of COMPLAIN. */
16173 invalid_nontype_parm_type_p (tree type, tsubst_flags_t complain)
16175 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
16177 else if (POINTER_TYPE_P (type))
16179 else if (TYPE_PTR_TO_MEMBER_P (type))
16181 else if (TREE_CODE (type) == TEMPLATE_TYPE_PARM)
16183 else if (TREE_CODE (type) == TYPENAME_TYPE)
16186 if (complain & tf_error)
16187 error ("%q#T is not a valid type for a template constant parameter", type);
16191 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
16192 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
16195 dependent_type_p_r (tree type)
16201 A type is dependent if it is:
16203 -- a template parameter. Template template parameters are types
16204 for us (since TYPE_P holds true for them) so we handle
16206 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
16207 || TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM)
16209 /* -- a qualified-id with a nested-name-specifier which contains a
16210 class-name that names a dependent type or whose unqualified-id
16211 names a dependent type. */
16212 if (TREE_CODE (type) == TYPENAME_TYPE)
16214 /* -- a cv-qualified type where the cv-unqualified type is
16216 type = TYPE_MAIN_VARIANT (type);
16217 /* -- a compound type constructed from any dependent type. */
16218 if (TYPE_PTR_TO_MEMBER_P (type))
16219 return (dependent_type_p (TYPE_PTRMEM_CLASS_TYPE (type))
16220 || dependent_type_p (TYPE_PTRMEM_POINTED_TO_TYPE
16222 else if (TREE_CODE (type) == POINTER_TYPE
16223 || TREE_CODE (type) == REFERENCE_TYPE)
16224 return dependent_type_p (TREE_TYPE (type));
16225 else if (TREE_CODE (type) == FUNCTION_TYPE
16226 || TREE_CODE (type) == METHOD_TYPE)
16230 if (dependent_type_p (TREE_TYPE (type)))
16232 for (arg_type = TYPE_ARG_TYPES (type);
16234 arg_type = TREE_CHAIN (arg_type))
16235 if (dependent_type_p (TREE_VALUE (arg_type)))
16239 /* -- an array type constructed from any dependent type or whose
16240 size is specified by a constant expression that is
16241 value-dependent. */
16242 if (TREE_CODE (type) == ARRAY_TYPE)
16244 if (TYPE_DOMAIN (type)
16245 && dependent_type_p (TYPE_DOMAIN (type)))
16247 return dependent_type_p (TREE_TYPE (type));
16249 else if (TREE_CODE (type) == INTEGER_TYPE
16250 && !TREE_CONSTANT (TYPE_MAX_VALUE (type)))
16252 /* If this is the TYPE_DOMAIN of an array type, consider it
16253 dependent. We already checked for value-dependence in
16254 compute_array_index_type. */
16255 return type_dependent_expression_p (TYPE_MAX_VALUE (type));
16258 /* -- a template-id in which either the template name is a template
16260 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
16262 /* ... or any of the template arguments is a dependent type or
16263 an expression that is type-dependent or value-dependent. */
16264 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INFO (type)
16265 && (any_dependent_template_arguments_p
16266 (INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type)))))
16269 /* All TYPEOF_TYPEs and DECLTYPE_TYPEs are dependent; if the
16270 argument of the `typeof' expression is not type-dependent, then
16271 it should already been have resolved. */
16272 if (TREE_CODE (type) == TYPEOF_TYPE
16273 || TREE_CODE (type) == DECLTYPE_TYPE)
16276 /* A template argument pack is dependent if any of its packed
16278 if (TREE_CODE (type) == TYPE_ARGUMENT_PACK)
16280 tree args = ARGUMENT_PACK_ARGS (type);
16281 int i, len = TREE_VEC_LENGTH (args);
16282 for (i = 0; i < len; ++i)
16283 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
16287 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
16288 be template parameters. */
16289 if (TREE_CODE (type) == TYPE_PACK_EXPANSION)
16292 /* The standard does not specifically mention types that are local
16293 to template functions or local classes, but they should be
16294 considered dependent too. For example:
16296 template <int I> void f() {
16301 The size of `E' cannot be known until the value of `I' has been
16302 determined. Therefore, `E' must be considered dependent. */
16303 scope = TYPE_CONTEXT (type);
16304 if (scope && TYPE_P (scope))
16305 return dependent_type_p (scope);
16306 else if (scope && TREE_CODE (scope) == FUNCTION_DECL)
16307 return type_dependent_expression_p (scope);
16309 /* Other types are non-dependent. */
16313 /* Returns TRUE if TYPE is dependent, in the sense of
16314 [temp.dep.type]. */
16317 dependent_type_p (tree type)
16319 /* If there are no template parameters in scope, then there can't be
16320 any dependent types. */
16321 if (!processing_template_decl)
16323 /* If we are not processing a template, then nobody should be
16324 providing us with a dependent type. */
16326 gcc_assert (TREE_CODE (type) != TEMPLATE_TYPE_PARM || is_auto (type));
16330 /* If the type is NULL, we have not computed a type for the entity
16331 in question; in that case, the type is dependent. */
16335 /* Erroneous types can be considered non-dependent. */
16336 if (type == error_mark_node)
16339 /* If we have not already computed the appropriate value for TYPE,
16341 if (!TYPE_DEPENDENT_P_VALID (type))
16343 TYPE_DEPENDENT_P (type) = dependent_type_p_r (type);
16344 TYPE_DEPENDENT_P_VALID (type) = 1;
16347 return TYPE_DEPENDENT_P (type);
16350 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
16351 lookup. In other words, a dependent type that is not the current
16355 dependent_scope_p (tree scope)
16357 return (scope && TYPE_P (scope) && dependent_type_p (scope)
16358 && !currently_open_class (scope));
16361 /* Returns TRUE if EXPRESSION is dependent, according to CRITERION. */
16364 dependent_scope_ref_p (tree expression, bool criterion (tree))
16369 gcc_assert (TREE_CODE (expression) == SCOPE_REF);
16371 if (!TYPE_P (TREE_OPERAND (expression, 0)))
16374 scope = TREE_OPERAND (expression, 0);
16375 name = TREE_OPERAND (expression, 1);
16379 An id-expression is type-dependent if it contains a
16380 nested-name-specifier that contains a class-name that names a
16382 /* The suggested resolution to Core Issue 224 implies that if the
16383 qualifying type is the current class, then we must peek
16386 && currently_open_class (scope)
16387 && !criterion (name))
16389 if (dependent_type_p (scope))
16395 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
16396 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
16400 value_dependent_expression_p (tree expression)
16402 if (!processing_template_decl)
16405 /* A name declared with a dependent type. */
16406 if (DECL_P (expression) && type_dependent_expression_p (expression))
16409 switch (TREE_CODE (expression))
16411 case IDENTIFIER_NODE:
16412 /* A name that has not been looked up -- must be dependent. */
16415 case TEMPLATE_PARM_INDEX:
16416 /* A non-type template parm. */
16420 /* A non-type template parm. */
16421 if (DECL_TEMPLATE_PARM_P (expression))
16423 return value_dependent_expression_p (DECL_INITIAL (expression));
16426 /* A constant with integral or enumeration type and is initialized
16427 with an expression that is value-dependent. */
16428 if (DECL_INITIAL (expression)
16429 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (expression))
16430 && value_dependent_expression_p (DECL_INITIAL (expression)))
16434 case DYNAMIC_CAST_EXPR:
16435 case STATIC_CAST_EXPR:
16436 case CONST_CAST_EXPR:
16437 case REINTERPRET_CAST_EXPR:
16439 /* These expressions are value-dependent if the type to which
16440 the cast occurs is dependent or the expression being casted
16441 is value-dependent. */
16443 tree type = TREE_TYPE (expression);
16445 if (dependent_type_p (type))
16448 /* A functional cast has a list of operands. */
16449 expression = TREE_OPERAND (expression, 0);
16452 /* If there are no operands, it must be an expression such
16453 as "int()". This should not happen for aggregate types
16454 because it would form non-constant expressions. */
16455 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
16460 if (TREE_CODE (expression) == TREE_LIST)
16461 return any_value_dependent_elements_p (expression);
16463 return value_dependent_expression_p (expression);
16468 /* A `sizeof' expression is value-dependent if the operand is
16469 type-dependent or is a pack expansion. */
16470 expression = TREE_OPERAND (expression, 0);
16471 if (PACK_EXPANSION_P (expression))
16473 else if (TYPE_P (expression))
16474 return dependent_type_p (expression);
16475 return type_dependent_expression_p (expression);
16478 return dependent_scope_ref_p (expression, value_dependent_expression_p);
16480 case COMPONENT_REF:
16481 return (value_dependent_expression_p (TREE_OPERAND (expression, 0))
16482 || value_dependent_expression_p (TREE_OPERAND (expression, 1)));
16485 /* A CALL_EXPR may appear in a constant expression if it is a
16486 call to a builtin function, e.g., __builtin_constant_p. All
16487 such calls are value-dependent. */
16490 case NONTYPE_ARGUMENT_PACK:
16491 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
16492 is value-dependent. */
16494 tree values = ARGUMENT_PACK_ARGS (expression);
16495 int i, len = TREE_VEC_LENGTH (values);
16497 for (i = 0; i < len; ++i)
16498 if (value_dependent_expression_p (TREE_VEC_ELT (values, i)))
16506 tree type2 = TRAIT_EXPR_TYPE2 (expression);
16507 return (dependent_type_p (TRAIT_EXPR_TYPE1 (expression))
16508 || (type2 ? dependent_type_p (type2) : false));
16512 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
16513 || (value_dependent_expression_p (TREE_OPERAND (expression, 2))));
16516 /* A constant expression is value-dependent if any subexpression is
16517 value-dependent. */
16518 switch (TREE_CODE_CLASS (TREE_CODE (expression)))
16520 case tcc_reference:
16522 return (value_dependent_expression_p
16523 (TREE_OPERAND (expression, 0)));
16525 case tcc_comparison:
16527 return ((value_dependent_expression_p
16528 (TREE_OPERAND (expression, 0)))
16529 || (value_dependent_expression_p
16530 (TREE_OPERAND (expression, 1))));
16532 case tcc_expression:
16536 for (i = 0; i < TREE_OPERAND_LENGTH (expression); ++i)
16537 /* In some cases, some of the operands may be missing.
16538 (For example, in the case of PREDECREMENT_EXPR, the
16539 amount to increment by may be missing.) That doesn't
16540 make the expression dependent. */
16541 if (TREE_OPERAND (expression, i)
16542 && (value_dependent_expression_p
16543 (TREE_OPERAND (expression, i))))
16553 /* The expression is not value-dependent. */
16557 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
16558 [temp.dep.expr]. */
16561 type_dependent_expression_p (tree expression)
16563 if (!processing_template_decl)
16566 if (expression == error_mark_node)
16569 /* An unresolved name is always dependent. */
16570 if (TREE_CODE (expression) == IDENTIFIER_NODE
16571 || TREE_CODE (expression) == USING_DECL)
16574 /* Some expression forms are never type-dependent. */
16575 if (TREE_CODE (expression) == PSEUDO_DTOR_EXPR
16576 || TREE_CODE (expression) == SIZEOF_EXPR
16577 || TREE_CODE (expression) == ALIGNOF_EXPR
16578 || TREE_CODE (expression) == TRAIT_EXPR
16579 || TREE_CODE (expression) == TYPEID_EXPR
16580 || TREE_CODE (expression) == DELETE_EXPR
16581 || TREE_CODE (expression) == VEC_DELETE_EXPR
16582 || TREE_CODE (expression) == THROW_EXPR)
16585 /* The types of these expressions depends only on the type to which
16586 the cast occurs. */
16587 if (TREE_CODE (expression) == DYNAMIC_CAST_EXPR
16588 || TREE_CODE (expression) == STATIC_CAST_EXPR
16589 || TREE_CODE (expression) == CONST_CAST_EXPR
16590 || TREE_CODE (expression) == REINTERPRET_CAST_EXPR
16591 || TREE_CODE (expression) == CAST_EXPR)
16592 return dependent_type_p (TREE_TYPE (expression));
16594 /* The types of these expressions depends only on the type created
16595 by the expression. */
16596 if (TREE_CODE (expression) == NEW_EXPR
16597 || TREE_CODE (expression) == VEC_NEW_EXPR)
16599 /* For NEW_EXPR tree nodes created inside a template, either
16600 the object type itself or a TREE_LIST may appear as the
16602 tree type = TREE_OPERAND (expression, 1);
16603 if (TREE_CODE (type) == TREE_LIST)
16604 /* This is an array type. We need to check array dimensions
16606 return dependent_type_p (TREE_VALUE (TREE_PURPOSE (type)))
16607 || value_dependent_expression_p
16608 (TREE_OPERAND (TREE_VALUE (type), 1));
16610 return dependent_type_p (type);
16613 if (TREE_CODE (expression) == SCOPE_REF
16614 && dependent_scope_ref_p (expression,
16615 type_dependent_expression_p))
16618 if (TREE_CODE (expression) == FUNCTION_DECL
16619 && DECL_LANG_SPECIFIC (expression)
16620 && DECL_TEMPLATE_INFO (expression)
16621 && (any_dependent_template_arguments_p
16622 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (expression)))))
16625 if (TREE_CODE (expression) == TEMPLATE_DECL
16626 && !DECL_TEMPLATE_TEMPLATE_PARM_P (expression))
16629 if (TREE_CODE (expression) == STMT_EXPR)
16630 expression = stmt_expr_value_expr (expression);
16632 if (BRACE_ENCLOSED_INITIALIZER_P (expression))
16637 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), i, elt)
16639 if (type_dependent_expression_p (elt))
16645 if (TREE_TYPE (expression) == unknown_type_node)
16647 if (TREE_CODE (expression) == ADDR_EXPR)
16648 return type_dependent_expression_p (TREE_OPERAND (expression, 0));
16649 if (TREE_CODE (expression) == COMPONENT_REF
16650 || TREE_CODE (expression) == OFFSET_REF)
16652 if (type_dependent_expression_p (TREE_OPERAND (expression, 0)))
16654 expression = TREE_OPERAND (expression, 1);
16655 if (TREE_CODE (expression) == IDENTIFIER_NODE)
16658 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
16659 if (TREE_CODE (expression) == SCOPE_REF)
16662 if (TREE_CODE (expression) == BASELINK)
16663 expression = BASELINK_FUNCTIONS (expression);
16665 if (TREE_CODE (expression) == TEMPLATE_ID_EXPR)
16667 if (any_dependent_template_arguments_p
16668 (TREE_OPERAND (expression, 1)))
16670 expression = TREE_OPERAND (expression, 0);
16672 gcc_assert (TREE_CODE (expression) == OVERLOAD
16673 || TREE_CODE (expression) == FUNCTION_DECL);
16677 if (type_dependent_expression_p (OVL_CURRENT (expression)))
16679 expression = OVL_NEXT (expression);
16684 gcc_assert (TREE_CODE (expression) != TYPE_DECL);
16686 return (dependent_type_p (TREE_TYPE (expression)));
16689 /* Like type_dependent_expression_p, but it also works while not processing
16690 a template definition, i.e. during substitution or mangling. */
16693 type_dependent_expression_p_push (tree expr)
16696 ++processing_template_decl;
16697 b = type_dependent_expression_p (expr);
16698 --processing_template_decl;
16702 /* Returns TRUE if ARGS contains a type-dependent expression. */
16705 any_type_dependent_arguments_p (const VEC(tree,gc) *args)
16710 for (i = 0; VEC_iterate (tree, args, i, arg); ++i)
16712 if (type_dependent_expression_p (arg))
16718 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
16719 expressions) contains any value-dependent expressions. */
16722 any_value_dependent_elements_p (const_tree list)
16724 for (; list; list = TREE_CHAIN (list))
16725 if (value_dependent_expression_p (TREE_VALUE (list)))
16731 /* Returns TRUE if the ARG (a template argument) is dependent. */
16734 dependent_template_arg_p (tree arg)
16736 if (!processing_template_decl)
16739 if (TREE_CODE (arg) == TEMPLATE_DECL
16740 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
16741 return dependent_template_p (arg);
16742 else if (ARGUMENT_PACK_P (arg))
16744 tree args = ARGUMENT_PACK_ARGS (arg);
16745 int i, len = TREE_VEC_LENGTH (args);
16746 for (i = 0; i < len; ++i)
16748 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
16754 else if (TYPE_P (arg))
16755 return dependent_type_p (arg);
16757 return (type_dependent_expression_p (arg)
16758 || value_dependent_expression_p (arg));
16761 /* Returns true if ARGS (a collection of template arguments) contains
16762 any types that require structural equality testing. */
16765 any_template_arguments_need_structural_equality_p (tree args)
16772 if (args == error_mark_node)
16775 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
16777 tree level = TMPL_ARGS_LEVEL (args, i + 1);
16778 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
16780 tree arg = TREE_VEC_ELT (level, j);
16781 tree packed_args = NULL_TREE;
16784 if (ARGUMENT_PACK_P (arg))
16786 /* Look inside the argument pack. */
16787 packed_args = ARGUMENT_PACK_ARGS (arg);
16788 len = TREE_VEC_LENGTH (packed_args);
16791 for (k = 0; k < len; ++k)
16794 arg = TREE_VEC_ELT (packed_args, k);
16796 if (error_operand_p (arg))
16798 else if (TREE_CODE (arg) == TEMPLATE_DECL
16799 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
16801 else if (TYPE_P (arg) && TYPE_STRUCTURAL_EQUALITY_P (arg))
16803 else if (!TYPE_P (arg) && TREE_TYPE (arg)
16804 && TYPE_STRUCTURAL_EQUALITY_P (TREE_TYPE (arg)))
16813 /* Returns true if ARGS (a collection of template arguments) contains
16814 any dependent arguments. */
16817 any_dependent_template_arguments_p (const_tree args)
16824 if (args == error_mark_node)
16827 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
16829 const_tree level = TMPL_ARGS_LEVEL (args, i + 1);
16830 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
16831 if (dependent_template_arg_p (TREE_VEC_ELT (level, j)))
16838 /* Returns TRUE if the template TMPL is dependent. */
16841 dependent_template_p (tree tmpl)
16843 if (TREE_CODE (tmpl) == OVERLOAD)
16847 if (dependent_template_p (OVL_FUNCTION (tmpl)))
16849 tmpl = OVL_CHAIN (tmpl);
16854 /* Template template parameters are dependent. */
16855 if (DECL_TEMPLATE_TEMPLATE_PARM_P (tmpl)
16856 || TREE_CODE (tmpl) == TEMPLATE_TEMPLATE_PARM)
16858 /* So are names that have not been looked up. */
16859 if (TREE_CODE (tmpl) == SCOPE_REF
16860 || TREE_CODE (tmpl) == IDENTIFIER_NODE)
16862 /* So are member templates of dependent classes. */
16863 if (TYPE_P (CP_DECL_CONTEXT (tmpl)))
16864 return dependent_type_p (DECL_CONTEXT (tmpl));
16868 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
16871 dependent_template_id_p (tree tmpl, tree args)
16873 return (dependent_template_p (tmpl)
16874 || any_dependent_template_arguments_p (args));
16877 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
16881 dependent_omp_for_p (tree declv, tree initv, tree condv, tree incrv)
16885 if (!processing_template_decl)
16888 for (i = 0; i < TREE_VEC_LENGTH (declv); i++)
16890 tree decl = TREE_VEC_ELT (declv, i);
16891 tree init = TREE_VEC_ELT (initv, i);
16892 tree cond = TREE_VEC_ELT (condv, i);
16893 tree incr = TREE_VEC_ELT (incrv, i);
16895 if (type_dependent_expression_p (decl))
16898 if (init && type_dependent_expression_p (init))
16901 if (type_dependent_expression_p (cond))
16904 if (COMPARISON_CLASS_P (cond)
16905 && (type_dependent_expression_p (TREE_OPERAND (cond, 0))
16906 || type_dependent_expression_p (TREE_OPERAND (cond, 1))))
16909 if (TREE_CODE (incr) == MODOP_EXPR)
16911 if (type_dependent_expression_p (TREE_OPERAND (incr, 0))
16912 || type_dependent_expression_p (TREE_OPERAND (incr, 2)))
16915 else if (type_dependent_expression_p (incr))
16917 else if (TREE_CODE (incr) == MODIFY_EXPR)
16919 if (type_dependent_expression_p (TREE_OPERAND (incr, 0)))
16921 else if (BINARY_CLASS_P (TREE_OPERAND (incr, 1)))
16923 tree t = TREE_OPERAND (incr, 1);
16924 if (type_dependent_expression_p (TREE_OPERAND (t, 0))
16925 || type_dependent_expression_p (TREE_OPERAND (t, 1)))
16934 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
16935 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
16936 no such TYPE can be found. Note that this function peers inside
16937 uninstantiated templates and therefore should be used only in
16938 extremely limited situations. ONLY_CURRENT_P restricts this
16939 peering to the currently open classes hierarchy (which is required
16940 when comparing types). */
16943 resolve_typename_type (tree type, bool only_current_p)
16952 gcc_assert (TREE_CODE (type) == TYPENAME_TYPE);
16954 scope = TYPE_CONTEXT (type);
16955 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
16956 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
16957 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
16958 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
16959 identifier of the TYPENAME_TYPE anymore.
16960 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
16961 TYPENAME_TYPE instead, we avoid messing up with a possible
16962 typedef variant case. */
16963 name = TYPE_IDENTIFIER (TYPE_MAIN_VARIANT (type));
16965 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
16966 it first before we can figure out what NAME refers to. */
16967 if (TREE_CODE (scope) == TYPENAME_TYPE)
16968 scope = resolve_typename_type (scope, only_current_p);
16969 /* If we don't know what SCOPE refers to, then we cannot resolve the
16971 if (TREE_CODE (scope) == TYPENAME_TYPE)
16973 /* If the SCOPE is a template type parameter, we have no way of
16974 resolving the name. */
16975 if (TREE_CODE (scope) == TEMPLATE_TYPE_PARM)
16977 /* If the SCOPE is not the current instantiation, there's no reason
16978 to look inside it. */
16979 if (only_current_p && !currently_open_class (scope))
16981 /* If SCOPE isn't the template itself, it will not have a valid
16982 TYPE_FIELDS list. */
16983 if (same_type_p (scope, CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope)))
16984 /* scope is either the template itself or a compatible instantiation
16985 like X<T>, so look up the name in the original template. */
16986 scope = CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope);
16988 /* scope is a partial instantiation, so we can't do the lookup or we
16989 will lose the template arguments. */
16991 /* Enter the SCOPE so that name lookup will be resolved as if we
16992 were in the class definition. In particular, SCOPE will no
16993 longer be considered a dependent type. */
16994 pushed_scope = push_scope (scope);
16995 /* Look up the declaration. */
16996 decl = lookup_member (scope, name, /*protect=*/0, /*want_type=*/true);
16998 result = NULL_TREE;
17000 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
17001 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
17004 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == IDENTIFIER_NODE
17005 && TREE_CODE (decl) == TYPE_DECL)
17007 result = TREE_TYPE (decl);
17008 if (result == error_mark_node)
17009 result = NULL_TREE;
17011 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == TEMPLATE_ID_EXPR
17012 && DECL_CLASS_TEMPLATE_P (decl))
17016 /* Obtain the template and the arguments. */
17017 tmpl = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 0);
17018 args = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 1);
17019 /* Instantiate the template. */
17020 result = lookup_template_class (tmpl, args, NULL_TREE, NULL_TREE,
17021 /*entering_scope=*/0,
17022 tf_error | tf_user);
17023 if (result == error_mark_node)
17024 result = NULL_TREE;
17027 /* Leave the SCOPE. */
17029 pop_scope (pushed_scope);
17031 /* If we failed to resolve it, return the original typename. */
17035 /* If lookup found a typename type, resolve that too. */
17036 if (TREE_CODE (result) == TYPENAME_TYPE && !TYPENAME_IS_RESOLVING_P (result))
17038 /* Ill-formed programs can cause infinite recursion here, so we
17039 must catch that. */
17040 TYPENAME_IS_RESOLVING_P (type) = 1;
17041 result = resolve_typename_type (result, only_current_p);
17042 TYPENAME_IS_RESOLVING_P (type) = 0;
17045 /* Qualify the resulting type. */
17046 quals = cp_type_quals (type);
17048 result = cp_build_qualified_type (result, cp_type_quals (result) | quals);
17053 /* EXPR is an expression which is not type-dependent. Return a proxy
17054 for EXPR that can be used to compute the types of larger
17055 expressions containing EXPR. */
17058 build_non_dependent_expr (tree expr)
17062 /* Preserve null pointer constants so that the type of things like
17063 "p == 0" where "p" is a pointer can be determined. */
17064 if (null_ptr_cst_p (expr))
17066 /* Preserve OVERLOADs; the functions must be available to resolve
17069 if (TREE_CODE (inner_expr) == STMT_EXPR)
17070 inner_expr = stmt_expr_value_expr (inner_expr);
17071 if (TREE_CODE (inner_expr) == ADDR_EXPR)
17072 inner_expr = TREE_OPERAND (inner_expr, 0);
17073 if (TREE_CODE (inner_expr) == COMPONENT_REF)
17074 inner_expr = TREE_OPERAND (inner_expr, 1);
17075 if (is_overloaded_fn (inner_expr)
17076 || TREE_CODE (inner_expr) == OFFSET_REF)
17078 /* There is no need to return a proxy for a variable. */
17079 if (TREE_CODE (expr) == VAR_DECL)
17081 /* Preserve string constants; conversions from string constants to
17082 "char *" are allowed, even though normally a "const char *"
17083 cannot be used to initialize a "char *". */
17084 if (TREE_CODE (expr) == STRING_CST)
17086 /* Preserve arithmetic constants, as an optimization -- there is no
17087 reason to create a new node. */
17088 if (TREE_CODE (expr) == INTEGER_CST || TREE_CODE (expr) == REAL_CST)
17090 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
17091 There is at least one place where we want to know that a
17092 particular expression is a throw-expression: when checking a ?:
17093 expression, there are special rules if the second or third
17094 argument is a throw-expression. */
17095 if (TREE_CODE (expr) == THROW_EXPR)
17098 if (TREE_CODE (expr) == COND_EXPR)
17099 return build3 (COND_EXPR,
17101 TREE_OPERAND (expr, 0),
17102 (TREE_OPERAND (expr, 1)
17103 ? build_non_dependent_expr (TREE_OPERAND (expr, 1))
17104 : build_non_dependent_expr (TREE_OPERAND (expr, 0))),
17105 build_non_dependent_expr (TREE_OPERAND (expr, 2)));
17106 if (TREE_CODE (expr) == COMPOUND_EXPR
17107 && !COMPOUND_EXPR_OVERLOADED (expr))
17108 return build2 (COMPOUND_EXPR,
17110 TREE_OPERAND (expr, 0),
17111 build_non_dependent_expr (TREE_OPERAND (expr, 1)));
17113 /* If the type is unknown, it can't really be non-dependent */
17114 gcc_assert (TREE_TYPE (expr) != unknown_type_node);
17116 /* Otherwise, build a NON_DEPENDENT_EXPR.
17118 REFERENCE_TYPEs are not stripped for expressions in templates
17119 because doing so would play havoc with mangling. Consider, for
17122 template <typename T> void f<T& g>() { g(); }
17124 In the body of "f", the expression for "g" will have
17125 REFERENCE_TYPE, even though the standard says that it should
17126 not. The reason is that we must preserve the syntactic form of
17127 the expression so that mangling (say) "f<g>" inside the body of
17128 "f" works out correctly. Therefore, the REFERENCE_TYPE is
17130 return build1 (NON_DEPENDENT_EXPR, non_reference (TREE_TYPE (expr)), expr);
17133 /* ARGS is a vector of expressions as arguments to a function call.
17134 Replace the arguments with equivalent non-dependent expressions.
17135 This modifies ARGS in place. */
17138 make_args_non_dependent (VEC(tree,gc) *args)
17143 for (ix = 0; VEC_iterate (tree, args, ix, arg); ++ix)
17145 tree newarg = build_non_dependent_expr (arg);
17147 VEC_replace (tree, args, ix, newarg);
17151 /* Returns a type which represents 'auto'. We use a TEMPLATE_TYPE_PARM
17152 with a level one deeper than the actual template parms. */
17159 /* ??? Is it worth caching this for multiple autos at the same level? */
17160 au = cxx_make_type (TEMPLATE_TYPE_PARM);
17161 TYPE_NAME (au) = build_decl (BUILTINS_LOCATION,
17162 TYPE_DECL, get_identifier ("auto"), au);
17163 TYPE_STUB_DECL (au) = TYPE_NAME (au);
17164 TEMPLATE_TYPE_PARM_INDEX (au) = build_template_parm_index
17165 (0, processing_template_decl + 1, processing_template_decl + 1,
17166 TYPE_NAME (au), NULL_TREE);
17167 TYPE_CANONICAL (au) = canonical_type_parameter (au);
17168 DECL_ARTIFICIAL (TYPE_NAME (au)) = 1;
17169 SET_DECL_TEMPLATE_PARM_P (TYPE_NAME (au));
17174 /* Replace auto in TYPE with std::initializer_list<auto>. */
17177 listify_autos (tree type, tree auto_node)
17179 tree std_init_list = namespace_binding
17180 (get_identifier ("initializer_list"), std_node);
17183 if (!std_init_list || !DECL_CLASS_TEMPLATE_P (std_init_list))
17185 error ("deducing auto from brace-enclosed initializer list requires "
17186 "#include <initializer_list>");
17187 return error_mark_node;
17189 argvec = make_tree_vec (1);
17190 TREE_VEC_ELT (argvec, 0) = auto_node;
17191 init_auto = lookup_template_class (std_init_list, argvec, NULL_TREE,
17192 NULL_TREE, 0, tf_warning_or_error);
17194 TREE_VEC_ELT (argvec, 0) = init_auto;
17195 if (processing_template_decl)
17196 argvec = add_to_template_args (current_template_args (), argvec);
17197 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
17200 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
17201 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
17204 do_auto_deduction (tree type, tree init, tree auto_node)
17206 tree parms, tparms, targs;
17210 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
17211 with either a new invented type template parameter U or, if the
17212 initializer is a braced-init-list (8.5.4), with
17213 std::initializer_list<U>. */
17214 if (BRACE_ENCLOSED_INITIALIZER_P (init))
17215 type = listify_autos (type, auto_node);
17217 parms = build_tree_list (NULL_TREE, type);
17219 tparms = make_tree_vec (1);
17220 targs = make_tree_vec (1);
17221 TREE_VEC_ELT (tparms, 0)
17222 = build_tree_list (NULL_TREE, TYPE_NAME (auto_node));
17223 val = type_unification_real (tparms, targs, parms, args, 1, 0,
17224 DEDUCE_CALL, LOOKUP_NORMAL);
17227 error ("unable to deduce %qT from %qE", type, init);
17228 return error_mark_node;
17231 if (processing_template_decl)
17232 targs = add_to_template_args (current_template_args (), targs);
17233 return tsubst (type, targs, tf_warning_or_error, NULL_TREE);
17236 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
17240 splice_late_return_type (tree type, tree late_return_type)
17244 if (late_return_type == NULL_TREE)
17246 argvec = make_tree_vec (1);
17247 TREE_VEC_ELT (argvec, 0) = late_return_type;
17248 if (processing_template_decl)
17249 argvec = add_to_template_args (current_template_args (), argvec);
17250 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
17253 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto'. */
17256 is_auto (const_tree type)
17258 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
17259 && TYPE_IDENTIFIER (type) == get_identifier ("auto"))
17265 /* Returns true iff TYPE contains a use of 'auto'. Since auto can only
17266 appear as a type-specifier for the declaration in question, we don't
17267 have to look through the whole type. */
17270 type_uses_auto (tree type)
17272 enum tree_code code;
17273 if (is_auto (type))
17276 code = TREE_CODE (type);
17278 if (code == POINTER_TYPE || code == REFERENCE_TYPE
17279 || code == OFFSET_TYPE || code == FUNCTION_TYPE
17280 || code == METHOD_TYPE || code == ARRAY_TYPE)
17281 return type_uses_auto (TREE_TYPE (type));
17283 if (TYPE_PTRMEMFUNC_P (type))
17284 return type_uses_auto (TREE_TYPE (TREE_TYPE
17285 (TYPE_PTRMEMFUNC_FN_TYPE (type))));
17290 /* For a given template T, return the list of typedefs referenced
17291 in T for which access check is needed at T instantiation time.
17292 T is either a FUNCTION_DECL or a RECORD_TYPE.
17293 Those typedefs were added to T by the function
17294 append_type_to_template_for_access_check. */
17297 get_types_needing_access_check (tree t)
17299 tree ti, result = NULL_TREE;
17301 if (!t || t == error_mark_node)
17304 if (!(ti = get_template_info (t)))
17307 if (TREE_CODE (t) == RECORD_TYPE || TREE_CODE (t) == FUNCTION_DECL)
17309 if (!TI_TEMPLATE (ti))
17312 result = TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti);
17318 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
17319 tied to T. That list of typedefs will be access checked at
17320 T instantiation time.
17321 T is either a FUNCTION_DECL or a RECORD_TYPE.
17322 TYPE_DECL is a TYPE_DECL node representing a typedef.
17323 SCOPE is the scope through which TYPE_DECL is accessed.
17325 This function is a subroutine of
17326 append_type_to_template_for_access_check. */
17329 append_type_to_template_for_access_check_1 (tree t,
17335 if (!t || t == error_mark_node)
17338 gcc_assert ((TREE_CODE (t) == FUNCTION_DECL
17339 || TREE_CODE (t) == RECORD_TYPE)
17341 && TREE_CODE (type_decl) == TYPE_DECL
17344 if (!(ti = get_template_info (t)))
17347 gcc_assert (TI_TEMPLATE (ti));
17349 TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti) =
17350 tree_cons (type_decl, scope, TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti));
17353 /* Append TYPE_DECL to the template TEMPL.
17354 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
17355 At TEMPL instanciation time, TYPE_DECL will be checked to see
17356 if it can be accessed through SCOPE.
17358 e.g. consider the following code snippet:
17365 template<class U> struct S
17372 At S<char> instantiation time, we need to check the access of C::myint
17373 In other words, we need to check the access of the myint typedef through
17374 the C scope. For that purpose, this function will add the myint typedef
17375 and the scope C through which its being accessed to a list of typedefs
17376 tied to the template S. That list will be walked at template instantiation
17377 time and access check performed on each typedefs it contains.
17378 Note that this particular code snippet should yield an error because
17379 myint is private to C. */
17382 append_type_to_template_for_access_check (tree templ,
17388 gcc_assert (type_decl && (TREE_CODE (type_decl) == TYPE_DECL));
17390 /* Make sure we don't append the type to the template twice. */
17391 for (node = get_types_needing_access_check (templ);
17393 node = TREE_CHAIN (node))
17395 tree decl = TREE_PURPOSE (node);
17396 tree type_scope = TREE_VALUE (node);
17398 if (decl == type_decl && type_scope == scope)
17402 append_type_to_template_for_access_check_1 (templ, type_decl, scope);
17405 #include "gt-cp-pt.h"