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 typedef struct GTY(()) spec_entry
92 static GTY ((param_is (spec_entry)))
93 htab_t decl_specializations;
95 static GTY ((param_is (spec_entry)))
96 htab_t type_specializations;
98 /* Contains canonical template parameter types. The vector is indexed by
99 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
100 TREE_LIST, whose TREE_VALUEs contain the canonical template
101 parameters of various types and levels. */
102 static GTY(()) VEC(tree,gc) *canonical_template_parms;
104 #define UNIFY_ALLOW_NONE 0
105 #define UNIFY_ALLOW_MORE_CV_QUAL 1
106 #define UNIFY_ALLOW_LESS_CV_QUAL 2
107 #define UNIFY_ALLOW_DERIVED 4
108 #define UNIFY_ALLOW_INTEGER 8
109 #define UNIFY_ALLOW_OUTER_LEVEL 16
110 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
111 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
113 static void push_access_scope (tree);
114 static void pop_access_scope (tree);
115 static bool resolve_overloaded_unification (tree, tree, tree, tree,
116 unification_kind_t, int);
117 static int try_one_overload (tree, tree, tree, tree, tree,
118 unification_kind_t, int, bool);
119 static int unify (tree, tree, tree, tree, int);
120 static void add_pending_template (tree);
121 static int push_tinst_level (tree);
122 static void pop_tinst_level (void);
123 static tree reopen_tinst_level (struct tinst_level *);
124 static tree tsubst_initializer_list (tree, tree);
125 static tree get_class_bindings (tree, tree, tree);
126 static tree coerce_template_parms (tree, tree, tree, tsubst_flags_t,
128 static void tsubst_enum (tree, tree, tree);
129 static tree add_to_template_args (tree, tree);
130 static tree add_outermost_template_args (tree, tree);
131 static bool check_instantiated_args (tree, tree, tsubst_flags_t);
132 static int maybe_adjust_types_for_deduction (unification_kind_t, tree*, tree*,
134 static int type_unification_real (tree, tree, tree, const tree *,
135 unsigned int, int, unification_kind_t, int);
136 static void note_template_header (int);
137 static tree convert_nontype_argument_function (tree, tree);
138 static tree convert_nontype_argument (tree, tree);
139 static tree convert_template_argument (tree, tree, tree,
140 tsubst_flags_t, int, tree);
141 static int for_each_template_parm (tree, tree_fn_t, void*,
142 struct pointer_set_t*, bool);
143 static tree expand_template_argument_pack (tree);
144 static tree build_template_parm_index (int, int, int, tree, tree);
145 static bool inline_needs_template_parms (tree);
146 static void push_inline_template_parms_recursive (tree, int);
147 static tree retrieve_local_specialization (tree);
148 static void register_local_specialization (tree, tree);
149 static hashval_t hash_specialization (const void *p);
150 static tree reduce_template_parm_level (tree, tree, int, tree, tsubst_flags_t);
151 static int mark_template_parm (tree, void *);
152 static int template_parm_this_level_p (tree, void *);
153 static tree tsubst_friend_function (tree, tree);
154 static tree tsubst_friend_class (tree, tree);
155 static int can_complete_type_without_circularity (tree);
156 static tree get_bindings (tree, tree, tree, bool);
157 static int template_decl_level (tree);
158 static int check_cv_quals_for_unify (int, tree, tree);
159 static void template_parm_level_and_index (tree, int*, int*);
160 static int unify_pack_expansion (tree, tree, tree, tree, int, bool, bool);
161 static tree tsubst_template_arg (tree, tree, tsubst_flags_t, tree);
162 static tree tsubst_template_args (tree, tree, tsubst_flags_t, tree);
163 static tree tsubst_template_parms (tree, tree, tsubst_flags_t);
164 static void regenerate_decl_from_template (tree, tree);
165 static tree most_specialized_class (tree, tree);
166 static tree tsubst_aggr_type (tree, tree, tsubst_flags_t, tree, int);
167 static tree tsubst_arg_types (tree, tree, tsubst_flags_t, tree);
168 static tree tsubst_function_type (tree, tree, tsubst_flags_t, tree);
169 static bool check_specialization_scope (void);
170 static tree process_partial_specialization (tree);
171 static void set_current_access_from_decl (tree);
172 static tree get_template_base (tree, tree, tree, tree);
173 static tree try_class_unification (tree, tree, tree, tree);
174 static int coerce_template_template_parms (tree, tree, tsubst_flags_t,
176 static bool template_template_parm_bindings_ok_p (tree, tree);
177 static int template_args_equal (tree, tree);
178 static void tsubst_default_arguments (tree);
179 static tree for_each_template_parm_r (tree *, int *, void *);
180 static tree copy_default_args_to_explicit_spec_1 (tree, tree);
181 static void copy_default_args_to_explicit_spec (tree);
182 static int invalid_nontype_parm_type_p (tree, tsubst_flags_t);
183 static int eq_local_specializations (const void *, const void *);
184 static bool dependent_template_arg_p (tree);
185 static bool any_template_arguments_need_structural_equality_p (tree);
186 static bool dependent_type_p_r (tree);
187 static tree tsubst_expr (tree, tree, tsubst_flags_t, tree, bool);
188 static tree tsubst_copy (tree, tree, tsubst_flags_t, tree);
189 static tree tsubst_pack_expansion (tree, tree, tsubst_flags_t, tree);
190 static tree tsubst_decl (tree, tree, tsubst_flags_t);
191 static void perform_typedefs_access_check (tree tmpl, tree targs);
192 static void append_type_to_template_for_access_check_1 (tree, tree, tree,
194 static hashval_t iterative_hash_template_arg (tree arg, hashval_t val);
195 static tree listify (tree);
196 static tree listify_autos (tree, tree);
198 /* Make the current scope suitable for access checking when we are
199 processing T. T can be FUNCTION_DECL for instantiated function
200 template, or VAR_DECL for static member variable (need by
201 instantiate_decl). */
204 push_access_scope (tree t)
206 gcc_assert (TREE_CODE (t) == FUNCTION_DECL
207 || TREE_CODE (t) == VAR_DECL);
209 if (DECL_FRIEND_CONTEXT (t))
210 push_nested_class (DECL_FRIEND_CONTEXT (t));
211 else if (DECL_CLASS_SCOPE_P (t))
212 push_nested_class (DECL_CONTEXT (t));
214 push_to_top_level ();
216 if (TREE_CODE (t) == FUNCTION_DECL)
218 saved_access_scope = tree_cons
219 (NULL_TREE, current_function_decl, saved_access_scope);
220 current_function_decl = t;
224 /* Restore the scope set up by push_access_scope. T is the node we
228 pop_access_scope (tree t)
230 if (TREE_CODE (t) == FUNCTION_DECL)
232 current_function_decl = TREE_VALUE (saved_access_scope);
233 saved_access_scope = TREE_CHAIN (saved_access_scope);
236 if (DECL_FRIEND_CONTEXT (t) || DECL_CLASS_SCOPE_P (t))
239 pop_from_top_level ();
242 /* Do any processing required when DECL (a member template
243 declaration) is finished. Returns the TEMPLATE_DECL corresponding
244 to DECL, unless it is a specialization, in which case the DECL
245 itself is returned. */
248 finish_member_template_decl (tree decl)
250 if (decl == error_mark_node)
251 return error_mark_node;
253 gcc_assert (DECL_P (decl));
255 if (TREE_CODE (decl) == TYPE_DECL)
259 type = TREE_TYPE (decl);
260 if (type == error_mark_node)
261 return error_mark_node;
262 if (MAYBE_CLASS_TYPE_P (type)
263 && CLASSTYPE_TEMPLATE_INFO (type)
264 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
266 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
267 check_member_template (tmpl);
272 else if (TREE_CODE (decl) == FIELD_DECL)
273 error ("data member %qD cannot be a member template", decl);
274 else if (DECL_TEMPLATE_INFO (decl))
276 if (!DECL_TEMPLATE_SPECIALIZATION (decl))
278 check_member_template (DECL_TI_TEMPLATE (decl));
279 return DECL_TI_TEMPLATE (decl);
285 error ("invalid member template declaration %qD", decl);
287 return error_mark_node;
290 /* Create a template info node. */
293 build_template_info (tree template_decl, tree template_args)
295 tree result = make_node (TEMPLATE_INFO);
296 TI_TEMPLATE (result) = template_decl;
297 TI_ARGS (result) = template_args;
301 /* Return the template info node corresponding to T, whatever T is. */
304 get_template_info (const_tree t)
306 tree tinfo = NULL_TREE;
308 if (!t || t == error_mark_node)
311 if (DECL_P (t) && DECL_LANG_SPECIFIC (t))
312 tinfo = DECL_TEMPLATE_INFO (t);
314 if (!tinfo && DECL_IMPLICIT_TYPEDEF_P (t))
317 if (TAGGED_TYPE_P (t))
318 tinfo = TYPE_TEMPLATE_INFO (t);
323 /* Returns the template nesting level of the indicated class TYPE.
333 A<T>::B<U> has depth two, while A<T> has depth one.
334 Both A<T>::B<int> and A<int>::B<U> have depth one, if
335 they are instantiations, not specializations.
337 This function is guaranteed to return 0 if passed NULL_TREE so
338 that, for example, `template_class_depth (current_class_type)' is
342 template_class_depth (tree type)
347 type && TREE_CODE (type) != NAMESPACE_DECL;
348 type = (TREE_CODE (type) == FUNCTION_DECL)
349 ? CP_DECL_CONTEXT (type) : TYPE_CONTEXT (type))
351 tree tinfo = get_template_info (type);
353 if (tinfo && PRIMARY_TEMPLATE_P (TI_TEMPLATE (tinfo))
354 && uses_template_parms (INNERMOST_TEMPLATE_ARGS (TI_ARGS (tinfo))))
361 /* Subroutine of maybe_begin_member_template_processing.
362 Returns true if processing DECL needs us to push template parms. */
365 inline_needs_template_parms (tree decl)
367 if (! DECL_TEMPLATE_INFO (decl))
370 return (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (most_general_template (decl)))
371 > (processing_template_decl + DECL_TEMPLATE_SPECIALIZATION (decl)));
374 /* Subroutine of maybe_begin_member_template_processing.
375 Push the template parms in PARMS, starting from LEVELS steps into the
376 chain, and ending at the beginning, since template parms are listed
380 push_inline_template_parms_recursive (tree parmlist, int levels)
382 tree parms = TREE_VALUE (parmlist);
386 push_inline_template_parms_recursive (TREE_CHAIN (parmlist), levels - 1);
388 ++processing_template_decl;
389 current_template_parms
390 = tree_cons (size_int (processing_template_decl),
391 parms, current_template_parms);
392 TEMPLATE_PARMS_FOR_INLINE (current_template_parms) = 1;
394 begin_scope (TREE_VEC_LENGTH (parms) ? sk_template_parms : sk_template_spec,
396 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
398 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
400 if (parm == error_mark_node)
403 gcc_assert (DECL_P (parm));
405 switch (TREE_CODE (parm))
414 /* Make a CONST_DECL as is done in process_template_parm.
415 It is ugly that we recreate this here; the original
416 version built in process_template_parm is no longer
418 tree decl = build_decl (DECL_SOURCE_LOCATION (parm),
419 CONST_DECL, DECL_NAME (parm),
421 DECL_ARTIFICIAL (decl) = 1;
422 TREE_CONSTANT (decl) = 1;
423 TREE_READONLY (decl) = 1;
424 DECL_INITIAL (decl) = DECL_INITIAL (parm);
425 SET_DECL_TEMPLATE_PARM_P (decl);
436 /* Restore the template parameter context for a member template or
437 a friend template defined in a class definition. */
440 maybe_begin_member_template_processing (tree decl)
445 if (inline_needs_template_parms (decl))
447 parms = DECL_TEMPLATE_PARMS (most_general_template (decl));
448 levels = TMPL_PARMS_DEPTH (parms) - processing_template_decl;
450 if (DECL_TEMPLATE_SPECIALIZATION (decl))
453 parms = TREE_CHAIN (parms);
456 push_inline_template_parms_recursive (parms, levels);
459 /* Remember how many levels of template parameters we pushed so that
460 we can pop them later. */
461 VEC_safe_push (int, heap, inline_parm_levels, levels);
464 /* Undo the effects of maybe_begin_member_template_processing. */
467 maybe_end_member_template_processing (void)
472 if (VEC_length (int, inline_parm_levels) == 0)
475 last = VEC_pop (int, inline_parm_levels);
476 for (i = 0; i < last; ++i)
478 --processing_template_decl;
479 current_template_parms = TREE_CHAIN (current_template_parms);
484 /* Return a new template argument vector which contains all of ARGS,
485 but has as its innermost set of arguments the EXTRA_ARGS. */
488 add_to_template_args (tree args, tree extra_args)
495 extra_depth = TMPL_ARGS_DEPTH (extra_args);
496 new_args = make_tree_vec (TMPL_ARGS_DEPTH (args) + extra_depth);
498 for (i = 1; i <= TMPL_ARGS_DEPTH (args); ++i)
499 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (args, i));
501 for (j = 1; j <= extra_depth; ++j, ++i)
502 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (extra_args, j));
507 /* Like add_to_template_args, but only the outermost ARGS are added to
508 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
509 (EXTRA_ARGS) levels are added. This function is used to combine
510 the template arguments from a partial instantiation with the
511 template arguments used to attain the full instantiation from the
512 partial instantiation. */
515 add_outermost_template_args (tree args, tree extra_args)
519 /* If there are more levels of EXTRA_ARGS than there are ARGS,
520 something very fishy is going on. */
521 gcc_assert (TMPL_ARGS_DEPTH (args) >= TMPL_ARGS_DEPTH (extra_args));
523 /* If *all* the new arguments will be the EXTRA_ARGS, just return
525 if (TMPL_ARGS_DEPTH (args) == TMPL_ARGS_DEPTH (extra_args))
528 /* For the moment, we make ARGS look like it contains fewer levels. */
529 TREE_VEC_LENGTH (args) -= TMPL_ARGS_DEPTH (extra_args);
531 new_args = add_to_template_args (args, extra_args);
533 /* Now, we restore ARGS to its full dimensions. */
534 TREE_VEC_LENGTH (args) += TMPL_ARGS_DEPTH (extra_args);
539 /* Return the N levels of innermost template arguments from the ARGS. */
542 get_innermost_template_args (tree args, int n)
550 /* If N is 1, just return the innermost set of template arguments. */
552 return TMPL_ARGS_LEVEL (args, TMPL_ARGS_DEPTH (args));
554 /* If we're not removing anything, just return the arguments we were
556 extra_levels = TMPL_ARGS_DEPTH (args) - n;
557 gcc_assert (extra_levels >= 0);
558 if (extra_levels == 0)
561 /* Make a new set of arguments, not containing the outer arguments. */
562 new_args = make_tree_vec (n);
563 for (i = 1; i <= n; ++i)
564 SET_TMPL_ARGS_LEVEL (new_args, i,
565 TMPL_ARGS_LEVEL (args, i + extra_levels));
570 /* The inverse of get_innermost_template_args: Return all but the innermost
571 EXTRA_LEVELS levels of template arguments from the ARGS. */
574 strip_innermost_template_args (tree args, int extra_levels)
577 int n = TMPL_ARGS_DEPTH (args) - extra_levels;
582 /* If N is 1, just return the outermost set of template arguments. */
584 return TMPL_ARGS_LEVEL (args, 1);
586 /* If we're not removing anything, just return the arguments we were
588 gcc_assert (extra_levels >= 0);
589 if (extra_levels == 0)
592 /* Make a new set of arguments, not containing the inner arguments. */
593 new_args = make_tree_vec (n);
594 for (i = 1; i <= n; ++i)
595 SET_TMPL_ARGS_LEVEL (new_args, i,
596 TMPL_ARGS_LEVEL (args, i));
601 /* We've got a template header coming up; push to a new level for storing
605 begin_template_parm_list (void)
607 /* We use a non-tag-transparent scope here, which causes pushtag to
608 put tags in this scope, rather than in the enclosing class or
609 namespace scope. This is the right thing, since we want
610 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
611 global template class, push_template_decl handles putting the
612 TEMPLATE_DECL into top-level scope. For a nested template class,
615 template <class T> struct S1 {
616 template <class T> struct S2 {};
619 pushtag contains special code to call pushdecl_with_scope on the
620 TEMPLATE_DECL for S2. */
621 begin_scope (sk_template_parms, NULL);
622 ++processing_template_decl;
623 ++processing_template_parmlist;
624 note_template_header (0);
627 /* This routine is called when a specialization is declared. If it is
628 invalid to declare a specialization here, an error is reported and
629 false is returned, otherwise this routine will return true. */
632 check_specialization_scope (void)
634 tree scope = current_scope ();
638 An explicit specialization shall be declared in the namespace of
639 which the template is a member, or, for member templates, in the
640 namespace of which the enclosing class or enclosing class
641 template is a member. An explicit specialization of a member
642 function, member class or static data member of a class template
643 shall be declared in the namespace of which the class template
645 if (scope && TREE_CODE (scope) != NAMESPACE_DECL)
647 error ("explicit specialization in non-namespace scope %qD", scope);
653 In an explicit specialization declaration for a member of a class
654 template or a member template that appears in namespace scope,
655 the member template and some of its enclosing class templates may
656 remain unspecialized, except that the declaration shall not
657 explicitly specialize a class member template if its enclosing
658 class templates are not explicitly specialized as well. */
659 if (current_template_parms)
661 error ("enclosing class templates are not explicitly specialized");
668 /* We've just seen template <>. */
671 begin_specialization (void)
673 begin_scope (sk_template_spec, NULL);
674 note_template_header (1);
675 return check_specialization_scope ();
678 /* Called at then end of processing a declaration preceded by
682 end_specialization (void)
685 reset_specialization ();
688 /* Any template <>'s that we have seen thus far are not referring to a
689 function specialization. */
692 reset_specialization (void)
694 processing_specialization = 0;
695 template_header_count = 0;
698 /* We've just seen a template header. If SPECIALIZATION is nonzero,
699 it was of the form template <>. */
702 note_template_header (int specialization)
704 processing_specialization = specialization;
705 template_header_count++;
708 /* We're beginning an explicit instantiation. */
711 begin_explicit_instantiation (void)
713 gcc_assert (!processing_explicit_instantiation);
714 processing_explicit_instantiation = true;
719 end_explicit_instantiation (void)
721 gcc_assert (processing_explicit_instantiation);
722 processing_explicit_instantiation = false;
725 /* An explicit specialization or partial specialization TMPL is being
726 declared. Check that the namespace in which the specialization is
727 occurring is permissible. Returns false iff it is invalid to
728 specialize TMPL in the current namespace. */
731 check_specialization_namespace (tree tmpl)
733 tree tpl_ns = decl_namespace_context (tmpl);
737 An explicit specialization shall be declared in the namespace of
738 which the template is a member, or, for member templates, in the
739 namespace of which the enclosing class or enclosing class
740 template is a member. An explicit specialization of a member
741 function, member class or static data member of a class template
742 shall be declared in the namespace of which the class template is
744 if (is_associated_namespace (current_namespace, tpl_ns))
745 /* Same or super-using namespace. */
749 permerror (input_location, "specialization of %qD in different namespace", tmpl);
750 permerror (input_location, " from definition of %q+#D", tmpl);
755 /* SPEC is an explicit instantiation. Check that it is valid to
756 perform this explicit instantiation in the current namespace. */
759 check_explicit_instantiation_namespace (tree spec)
763 /* DR 275: An explicit instantiation shall appear in an enclosing
764 namespace of its template. */
765 ns = decl_namespace_context (spec);
766 if (!is_ancestor (current_namespace, ns))
767 permerror (input_location, "explicit instantiation of %qD in namespace %qD "
768 "(which does not enclose namespace %qD)",
769 spec, current_namespace, ns);
772 /* The TYPE is being declared. If it is a template type, that means it
773 is a partial specialization. Do appropriate error-checking. */
776 maybe_process_partial_specialization (tree type)
780 if (type == error_mark_node)
781 return error_mark_node;
783 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
785 error ("name of class shadows template template parameter %qD",
787 return error_mark_node;
790 context = TYPE_CONTEXT (type);
792 if (CLASS_TYPE_P (type) && CLASSTYPE_USE_TEMPLATE (type))
794 /* This is for ordinary explicit specialization and partial
795 specialization of a template class such as:
797 template <> class C<int>;
801 template <class T> class C<T*>;
803 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
805 if (CLASSTYPE_IMPLICIT_INSTANTIATION (type)
806 && !COMPLETE_TYPE_P (type))
808 check_specialization_namespace (CLASSTYPE_TI_TEMPLATE (type));
809 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
810 if (processing_template_decl)
812 if (push_template_decl (TYPE_MAIN_DECL (type))
814 return error_mark_node;
817 else if (CLASSTYPE_TEMPLATE_INSTANTIATION (type))
818 error ("specialization of %qT after instantiation", type);
820 else if (CLASS_TYPE_P (type)
821 && !CLASSTYPE_USE_TEMPLATE (type)
822 && CLASSTYPE_TEMPLATE_INFO (type)
823 && context && CLASS_TYPE_P (context)
824 && CLASSTYPE_TEMPLATE_INFO (context))
826 /* This is for an explicit specialization of member class
827 template according to [temp.expl.spec/18]:
829 template <> template <class U> class C<int>::D;
831 The context `C<int>' must be an implicit instantiation.
832 Otherwise this is just a member class template declared
835 template <> class C<int> { template <class U> class D; };
836 template <> template <class U> class C<int>::D;
838 In the first case, `C<int>::D' is a specialization of `C<T>::D'
839 while in the second case, `C<int>::D' is a primary template
840 and `C<T>::D' may not exist. */
842 if (CLASSTYPE_IMPLICIT_INSTANTIATION (context)
843 && !COMPLETE_TYPE_P (type))
846 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
848 if (current_namespace
849 != decl_namespace_context (tmpl))
851 permerror (input_location, "specializing %q#T in different namespace", type);
852 permerror (input_location, " from definition of %q+#D", tmpl);
855 /* Check for invalid specialization after instantiation:
857 template <> template <> class C<int>::D<int>;
858 template <> template <class U> class C<int>::D; */
860 for (t = DECL_TEMPLATE_INSTANTIATIONS (tmpl);
861 t; t = TREE_CHAIN (t))
863 tree inst = TREE_VALUE (t);
864 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (inst))
866 /* We already have a full specialization of this partial
867 instantiation. Reassign it to the new member
868 specialization template. */
872 elt.tmpl = most_general_template (tmpl);
873 elt.args = CLASSTYPE_TI_ARGS (inst);
876 htab_remove_elt (type_specializations, &elt);
879 elt.args = INNERMOST_TEMPLATE_ARGS (elt.args);
881 slot = (spec_entry **)
882 htab_find_slot (type_specializations, &elt, INSERT);
883 *slot = GGC_NEW (spec_entry);
886 else if (COMPLETE_TYPE_P (inst) || TYPE_BEING_DEFINED (inst))
887 /* But if we've had an implicit instantiation, that's a
888 problem ([temp.expl.spec]/6). */
889 error ("specialization %qT after instantiation %qT",
893 /* Mark TYPE as a specialization. And as a result, we only
894 have one level of template argument for the innermost
896 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
897 CLASSTYPE_TI_ARGS (type)
898 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type));
901 else if (processing_specialization)
903 error ("explicit specialization of non-template %qT", type);
904 return error_mark_node;
910 /* Returns nonzero if we can optimize the retrieval of specializations
911 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
912 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
915 optimize_specialization_lookup_p (tree tmpl)
917 return (DECL_FUNCTION_TEMPLATE_P (tmpl)
918 && DECL_CLASS_SCOPE_P (tmpl)
919 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
921 && CLASS_TYPE_P (DECL_CONTEXT (tmpl))
922 /* The optimized lookup depends on the fact that the
923 template arguments for the member function template apply
924 purely to the containing class, which is not true if the
925 containing class is an explicit or partial
927 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (tmpl))
928 && !DECL_MEMBER_TEMPLATE_P (tmpl)
929 && !DECL_CONV_FN_P (tmpl)
930 /* It is possible to have a template that is not a member
931 template and is not a member of a template class:
933 template <typename T>
934 struct S { friend A::f(); };
936 Here, the friend function is a template, but the context does
937 not have template information. The optimized lookup relies
938 on having ARGS be the template arguments for both the class
939 and the function template. */
940 && !DECL_FRIEND_P (DECL_TEMPLATE_RESULT (tmpl)));
943 /* Retrieve the specialization (in the sense of [temp.spec] - a
944 specialization is either an instantiation or an explicit
945 specialization) of TMPL for the given template ARGS. If there is
946 no such specialization, return NULL_TREE. The ARGS are a vector of
947 arguments, or a vector of vectors of arguments, in the case of
948 templates with more than one level of parameters.
950 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
951 then we search for a partial specialization matching ARGS. This
952 parameter is ignored if TMPL is not a class template. */
955 retrieve_specialization (tree tmpl, tree args, hashval_t hash)
957 if (args == error_mark_node)
960 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
962 /* There should be as many levels of arguments as there are
963 levels of parameters. */
964 gcc_assert (TMPL_ARGS_DEPTH (args)
965 == TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl)));
967 if (optimize_specialization_lookup_p (tmpl))
970 tree class_specialization;
971 VEC(tree,gc) *methods;
975 /* The template arguments actually apply to the containing
976 class. Find the class specialization with those
978 class_template = CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (tmpl));
980 = retrieve_specialization (class_template, args, 0);
981 if (!class_specialization)
983 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
984 for the specialization. */
985 idx = class_method_index_for_fn (class_specialization, tmpl);
988 /* Iterate through the methods with the indicated name, looking
989 for the one that has an instance of TMPL. */
990 methods = CLASSTYPE_METHOD_VEC (class_specialization);
991 for (fns = VEC_index (tree, methods, idx); fns; fns = OVL_NEXT (fns))
993 tree fn = OVL_CURRENT (fns);
994 if (DECL_TEMPLATE_INFO (fn) && DECL_TI_TEMPLATE (fn) == tmpl
995 /* using-declarations can add base methods to the method vec,
996 and we don't want those here. */
997 && DECL_CONTEXT (fn) == class_specialization)
1006 htab_t specializations;
1010 elt.spec = NULL_TREE;
1012 if (DECL_CLASS_TEMPLATE_P (tmpl))
1013 specializations = type_specializations;
1015 specializations = decl_specializations;
1018 hash = hash_specialization (&elt);
1019 found = (spec_entry *) htab_find_with_hash (specializations, &elt, hash);
1027 /* Like retrieve_specialization, but for local declarations. */
1030 retrieve_local_specialization (tree tmpl)
1034 if (local_specializations == NULL)
1037 spec = (tree) htab_find_with_hash (local_specializations, tmpl,
1038 htab_hash_pointer (tmpl));
1039 return spec ? TREE_PURPOSE (spec) : NULL_TREE;
1042 /* Returns nonzero iff DECL is a specialization of TMPL. */
1045 is_specialization_of (tree decl, tree tmpl)
1049 if (TREE_CODE (decl) == FUNCTION_DECL)
1053 t = DECL_TEMPLATE_INFO (t) ? DECL_TI_TEMPLATE (t) : NULL_TREE)
1059 gcc_assert (TREE_CODE (decl) == TYPE_DECL);
1061 for (t = TREE_TYPE (decl);
1063 t = CLASSTYPE_USE_TEMPLATE (t)
1064 ? TREE_TYPE (CLASSTYPE_TI_TEMPLATE (t)) : NULL_TREE)
1065 if (same_type_ignoring_top_level_qualifiers_p (t, TREE_TYPE (tmpl)))
1072 /* Returns nonzero iff DECL is a specialization of friend declaration
1073 FRIEND_DECL according to [temp.friend]. */
1076 is_specialization_of_friend (tree decl, tree friend_decl)
1078 bool need_template = true;
1081 gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
1082 || TREE_CODE (decl) == TYPE_DECL);
1084 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1085 of a template class, we want to check if DECL is a specialization
1087 if (TREE_CODE (friend_decl) == FUNCTION_DECL
1088 && DECL_TEMPLATE_INFO (friend_decl)
1089 && !DECL_USE_TEMPLATE (friend_decl))
1091 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1092 friend_decl = DECL_TI_TEMPLATE (friend_decl);
1093 need_template = false;
1095 else if (TREE_CODE (friend_decl) == TEMPLATE_DECL
1096 && !PRIMARY_TEMPLATE_P (friend_decl))
1097 need_template = false;
1099 /* There is nothing to do if this is not a template friend. */
1100 if (TREE_CODE (friend_decl) != TEMPLATE_DECL)
1103 if (is_specialization_of (decl, friend_decl))
1107 A member of a class template may be declared to be a friend of a
1108 non-template class. In this case, the corresponding member of
1109 every specialization of the class template is a friend of the
1110 class granting friendship.
1112 For example, given a template friend declaration
1114 template <class T> friend void A<T>::f();
1116 the member function below is considered a friend
1118 template <> struct A<int> {
1122 For this type of template friend, TEMPLATE_DEPTH below will be
1123 nonzero. To determine if DECL is a friend of FRIEND, we first
1124 check if the enclosing class is a specialization of another. */
1126 template_depth = template_class_depth (DECL_CONTEXT (friend_decl));
1128 && DECL_CLASS_SCOPE_P (decl)
1129 && is_specialization_of (TYPE_NAME (DECL_CONTEXT (decl)),
1130 CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (friend_decl))))
1132 /* Next, we check the members themselves. In order to handle
1133 a few tricky cases, such as when FRIEND_DECL's are
1135 template <class T> friend void A<T>::g(T t);
1136 template <class T> template <T t> friend void A<T>::h();
1140 void A<int>::g(int);
1141 template <int> void A<int>::h();
1143 we need to figure out ARGS, the template arguments from
1144 the context of DECL. This is required for template substitution
1145 of `T' in the function parameter of `g' and template parameter
1146 of `h' in the above examples. Here ARGS corresponds to `int'. */
1148 tree context = DECL_CONTEXT (decl);
1149 tree args = NULL_TREE;
1150 int current_depth = 0;
1152 while (current_depth < template_depth)
1154 if (CLASSTYPE_TEMPLATE_INFO (context))
1156 if (current_depth == 0)
1157 args = TYPE_TI_ARGS (context);
1159 args = add_to_template_args (TYPE_TI_ARGS (context), args);
1162 context = TYPE_CONTEXT (context);
1165 if (TREE_CODE (decl) == FUNCTION_DECL)
1170 tree friend_args_type;
1171 tree decl_args_type;
1173 /* Make sure that both DECL and FRIEND_DECL are templates or
1175 is_template = DECL_TEMPLATE_INFO (decl)
1176 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (decl));
1177 if (need_template ^ is_template)
1179 else if (is_template)
1181 /* If both are templates, check template parameter list. */
1183 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1185 if (!comp_template_parms
1186 (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (decl)),
1190 decl_type = TREE_TYPE (DECL_TI_TEMPLATE (decl));
1193 decl_type = TREE_TYPE (decl);
1195 friend_type = tsubst_function_type (TREE_TYPE (friend_decl), args,
1196 tf_none, NULL_TREE);
1197 if (friend_type == error_mark_node)
1200 /* Check if return types match. */
1201 if (!same_type_p (TREE_TYPE (decl_type), TREE_TYPE (friend_type)))
1204 /* Check if function parameter types match, ignoring the
1205 `this' parameter. */
1206 friend_args_type = TYPE_ARG_TYPES (friend_type);
1207 decl_args_type = TYPE_ARG_TYPES (decl_type);
1208 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (friend_decl))
1209 friend_args_type = TREE_CHAIN (friend_args_type);
1210 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1211 decl_args_type = TREE_CHAIN (decl_args_type);
1213 return compparms (decl_args_type, friend_args_type);
1217 /* DECL is a TYPE_DECL */
1219 tree decl_type = TREE_TYPE (decl);
1221 /* Make sure that both DECL and FRIEND_DECL are templates or
1224 = CLASSTYPE_TEMPLATE_INFO (decl_type)
1225 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (decl_type));
1227 if (need_template ^ is_template)
1229 else if (is_template)
1232 /* If both are templates, check the name of the two
1233 TEMPLATE_DECL's first because is_friend didn't. */
1234 if (DECL_NAME (CLASSTYPE_TI_TEMPLATE (decl_type))
1235 != DECL_NAME (friend_decl))
1238 /* Now check template parameter list. */
1240 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1242 return comp_template_parms
1243 (DECL_TEMPLATE_PARMS (CLASSTYPE_TI_TEMPLATE (decl_type)),
1247 return (DECL_NAME (decl)
1248 == DECL_NAME (friend_decl));
1254 /* Register the specialization SPEC as a specialization of TMPL with
1255 the indicated ARGS. IS_FRIEND indicates whether the specialization
1256 is actually just a friend declaration. Returns SPEC, or an
1257 equivalent prior declaration, if available. */
1260 register_specialization (tree spec, tree tmpl, tree args, bool is_friend,
1264 spec_entry **slot = NULL;
1267 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL && DECL_P (spec));
1269 if (TREE_CODE (spec) == FUNCTION_DECL
1270 && uses_template_parms (DECL_TI_ARGS (spec)))
1271 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1272 register it; we want the corresponding TEMPLATE_DECL instead.
1273 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1274 the more obvious `uses_template_parms (spec)' to avoid problems
1275 with default function arguments. In particular, given
1276 something like this:
1278 template <class T> void f(T t1, T t = T())
1280 the default argument expression is not substituted for in an
1281 instantiation unless and until it is actually needed. */
1284 if (optimize_specialization_lookup_p (tmpl))
1285 /* We don't put these specializations in the hash table, but we might
1286 want to give an error about a mismatch. */
1287 fn = retrieve_specialization (tmpl, args, 0);
1295 hash = hash_specialization (&elt);
1297 slot = (spec_entry **)
1298 htab_find_slot_with_hash (decl_specializations, &elt, hash, INSERT);
1305 /* We can sometimes try to re-register a specialization that we've
1306 already got. In particular, regenerate_decl_from_template calls
1307 duplicate_decls which will update the specialization list. But,
1308 we'll still get called again here anyhow. It's more convenient
1309 to simply allow this than to try to prevent it. */
1312 else if (fn && DECL_TEMPLATE_SPECIALIZATION (spec))
1314 if (DECL_TEMPLATE_INSTANTIATION (fn))
1316 if (DECL_ODR_USED (fn)
1317 || DECL_EXPLICIT_INSTANTIATION (fn))
1319 error ("specialization of %qD after instantiation",
1321 return error_mark_node;
1326 /* This situation should occur only if the first
1327 specialization is an implicit instantiation, the
1328 second is an explicit specialization, and the
1329 implicit instantiation has not yet been used. That
1330 situation can occur if we have implicitly
1331 instantiated a member function and then specialized
1334 We can also wind up here if a friend declaration that
1335 looked like an instantiation turns out to be a
1338 template <class T> void foo(T);
1339 class S { friend void foo<>(int) };
1340 template <> void foo(int);
1342 We transform the existing DECL in place so that any
1343 pointers to it become pointers to the updated
1346 If there was a definition for the template, but not
1347 for the specialization, we want this to look as if
1348 there were no definition, and vice versa. */
1349 DECL_INITIAL (fn) = NULL_TREE;
1350 duplicate_decls (spec, fn, is_friend);
1351 /* The call to duplicate_decls will have applied
1354 An explicit specialization of a function template
1355 is inline only if it is explicitly declared to be,
1356 and independently of whether its function template
1359 to the primary function; now copy the inline bits to
1360 the various clones. */
1361 FOR_EACH_CLONE (clone, fn)
1363 DECL_DECLARED_INLINE_P (clone)
1364 = DECL_DECLARED_INLINE_P (fn);
1365 DECL_SOURCE_LOCATION (clone)
1366 = DECL_SOURCE_LOCATION (fn);
1368 check_specialization_namespace (fn);
1373 else if (DECL_TEMPLATE_SPECIALIZATION (fn))
1375 if (!duplicate_decls (spec, fn, is_friend) && DECL_INITIAL (spec))
1376 /* Dup decl failed, but this is a new definition. Set the
1377 line number so any errors match this new
1379 DECL_SOURCE_LOCATION (fn) = DECL_SOURCE_LOCATION (spec);
1385 return duplicate_decls (spec, fn, is_friend);
1387 /* A specialization must be declared in the same namespace as the
1388 template it is specializing. */
1389 if (DECL_TEMPLATE_SPECIALIZATION (spec)
1390 && !check_specialization_namespace (tmpl))
1391 DECL_CONTEXT (spec) = DECL_CONTEXT (tmpl);
1393 if (!optimize_specialization_lookup_p (tmpl))
1395 gcc_assert (tmpl && args && spec);
1396 *slot = GGC_NEW (spec_entry);
1398 if (TREE_CODE (spec) == FUNCTION_DECL && DECL_NAMESPACE_SCOPE_P (spec)
1399 && PRIMARY_TEMPLATE_P (tmpl)
1400 && DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (tmpl)) == NULL_TREE)
1401 /* TMPL is a forward declaration of a template function; keep a list
1402 of all specializations in case we need to reassign them to a friend
1403 template later in tsubst_friend_function. */
1404 DECL_TEMPLATE_INSTANTIATIONS (tmpl)
1405 = tree_cons (args, spec, DECL_TEMPLATE_INSTANTIATIONS (tmpl));
1411 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1412 TMPL and ARGS members, ignores SPEC. */
1415 eq_specializations (const void *p1, const void *p2)
1417 const spec_entry *e1 = (const spec_entry *)p1;
1418 const spec_entry *e2 = (const spec_entry *)p2;
1420 return (e1->tmpl == e2->tmpl
1421 && comp_template_args (e1->args, e2->args));
1424 /* Returns a hash for a template TMPL and template arguments ARGS. */
1427 hash_tmpl_and_args (tree tmpl, tree args)
1429 hashval_t val = DECL_UID (tmpl);
1430 return iterative_hash_template_arg (args, val);
1433 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1437 hash_specialization (const void *p)
1439 const spec_entry *e = (const spec_entry *)p;
1440 return hash_tmpl_and_args (e->tmpl, e->args);
1443 /* Recursively calculate a hash value for a template argument ARG, for use
1444 in the hash tables of template specializations. */
1447 iterative_hash_template_arg (tree arg, hashval_t val)
1449 unsigned HOST_WIDE_INT i;
1450 enum tree_code code;
1453 if (arg == NULL_TREE)
1454 return iterative_hash_object (arg, val);
1459 code = TREE_CODE (arg);
1460 tclass = TREE_CODE_CLASS (code);
1462 val = iterative_hash_object (code, val);
1469 case IDENTIFIER_NODE:
1470 return iterative_hash_object (IDENTIFIER_HASH_VALUE (arg), val);
1474 int i, len = TREE_VEC_LENGTH (arg);
1475 for (i = 0; i < len; ++i)
1476 val = iterative_hash_template_arg (TREE_VEC_ELT (arg, i), val);
1480 case TYPE_PACK_EXPANSION:
1481 case EXPR_PACK_EXPANSION:
1482 return iterative_hash_template_arg (PACK_EXPANSION_PATTERN (arg), val);
1484 case ARGUMENT_PACK_SELECT:
1485 /* We can get one of these when re-hashing a previous entry in the middle
1486 of substituting into a pack expansion. Just look through it... */
1487 arg = ARGUMENT_PACK_SELECT_FROM_PACK (arg);
1488 /* ...and fall through. */
1489 case TYPE_ARGUMENT_PACK:
1490 case NONTYPE_ARGUMENT_PACK:
1491 return iterative_hash_template_arg (ARGUMENT_PACK_ARGS (arg), val);
1494 for (; arg; arg = TREE_CHAIN (arg))
1495 val = iterative_hash_template_arg (TREE_VALUE (arg), val);
1499 for (; arg; arg = OVL_CHAIN (arg))
1500 val = iterative_hash_template_arg (OVL_FUNCTION (arg), val);
1506 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg), i, field, value)
1508 val = iterative_hash_template_arg (field, val);
1509 val = iterative_hash_template_arg (value, val);
1515 if (!DECL_ARTIFICIAL (arg))
1516 val = iterative_hash_object (DECL_PARM_INDEX (arg), val);
1517 return iterative_hash_template_arg (TREE_TYPE (arg), val);
1520 return iterative_hash_template_arg (TARGET_EXPR_INITIAL (arg), val);
1523 val = iterative_hash_template_arg (PTRMEM_CST_CLASS (arg), val);
1524 return iterative_hash_template_arg (PTRMEM_CST_MEMBER (arg), val);
1526 case TEMPLATE_PARM_INDEX:
1527 val = iterative_hash_template_arg
1528 (TREE_TYPE (TEMPLATE_PARM_DECL (arg)), val);
1529 val = iterative_hash_object (TEMPLATE_PARM_LEVEL (arg), val);
1530 return iterative_hash_object (TEMPLATE_PARM_IDX (arg), val);
1533 val = iterative_hash_object (TRAIT_EXPR_KIND (arg), val);
1534 val = iterative_hash_template_arg (TRAIT_EXPR_TYPE1 (arg), val);
1535 return iterative_hash_template_arg (TRAIT_EXPR_TYPE2 (arg), val);
1538 val = iterative_hash_template_arg (BINFO_TYPE (BASELINK_BINFO (arg)),
1540 return iterative_hash_template_arg (DECL_NAME (get_first_fn (arg)),
1544 val = iterative_hash_template_arg (TREE_OPERAND (arg, 0), val);
1545 code = TREE_CODE (TREE_OPERAND (arg, 1));
1546 val = iterative_hash_object (code, val);
1547 return iterative_hash_template_arg (TREE_OPERAND (arg, 2), val);
1553 if (TYPE_CANONICAL (arg))
1554 return iterative_hash_object (TYPE_HASH (TYPE_CANONICAL (arg)),
1556 else if (TREE_CODE (arg) == DECLTYPE_TYPE)
1557 return iterative_hash_template_arg (DECLTYPE_TYPE_EXPR (arg), val);
1558 /* Otherwise just compare the types during lookup. */
1561 case tcc_declaration:
1563 return iterative_hash_expr (arg, val);
1566 gcc_assert (IS_EXPR_CODE_CLASS (tclass));
1568 unsigned n = TREE_OPERAND_LENGTH (arg);
1569 for (i = 0; i < n; ++i)
1570 val = iterative_hash_template_arg (TREE_OPERAND (arg, i), val);
1579 /* Unregister the specialization SPEC as a specialization of TMPL.
1580 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1581 if the SPEC was listed as a specialization of TMPL.
1583 Note that SPEC has been ggc_freed, so we can't look inside it. */
1586 reregister_specialization (tree spec, tree tinfo, tree new_spec)
1591 elt.tmpl = most_general_template (TI_TEMPLATE (tinfo));
1592 elt.args = TI_ARGS (tinfo);
1593 elt.spec = NULL_TREE;
1595 slot = (spec_entry **) htab_find_slot (decl_specializations, &elt, INSERT);
1598 gcc_assert ((*slot)->spec == spec || (*slot)->spec == new_spec);
1599 gcc_assert (new_spec != NULL_TREE);
1600 (*slot)->spec = new_spec;
1607 /* Compare an entry in the local specializations hash table P1 (which
1608 is really a pointer to a TREE_LIST) with P2 (which is really a
1612 eq_local_specializations (const void *p1, const void *p2)
1614 return TREE_VALUE ((const_tree) p1) == (const_tree) p2;
1617 /* Hash P1, an entry in the local specializations table. */
1620 hash_local_specialization (const void* p1)
1622 return htab_hash_pointer (TREE_VALUE ((const_tree) p1));
1625 /* Like register_specialization, but for local declarations. We are
1626 registering SPEC, an instantiation of TMPL. */
1629 register_local_specialization (tree spec, tree tmpl)
1633 slot = htab_find_slot_with_hash (local_specializations, tmpl,
1634 htab_hash_pointer (tmpl), INSERT);
1635 *slot = build_tree_list (spec, tmpl);
1638 /* TYPE is a class type. Returns true if TYPE is an explicitly
1639 specialized class. */
1642 explicit_class_specialization_p (tree type)
1644 if (!CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
1646 return !uses_template_parms (CLASSTYPE_TI_ARGS (type));
1649 /* Print the list of overloaded FNS in an error message. */
1652 print_overloaded_functions (tree fns, const char **str)
1655 for (fn = fns; fn; fn = OVL_NEXT (fn))
1657 if (TREE_CODE (fn) == TREE_LIST)
1658 print_candidates (fn);
1660 error ("%s %+#D", *str, OVL_CURRENT (fn));
1665 /* Print the list of candidate FNS in an error message. */
1668 print_candidates (tree fns)
1670 const char *str = "candidates are:";
1672 if (is_overloaded_fn (fns))
1673 print_overloaded_functions (fns, &str);
1677 for (fn = fns; fn != NULL_TREE; fn = TREE_CHAIN (fn))
1678 print_overloaded_functions (TREE_VALUE (fn), &str);
1682 /* Returns the template (one of the functions given by TEMPLATE_ID)
1683 which can be specialized to match the indicated DECL with the
1684 explicit template args given in TEMPLATE_ID. The DECL may be
1685 NULL_TREE if none is available. In that case, the functions in
1686 TEMPLATE_ID are non-members.
1688 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1689 specialization of a member template.
1691 The TEMPLATE_COUNT is the number of references to qualifying
1692 template classes that appeared in the name of the function. See
1693 check_explicit_specialization for a more accurate description.
1695 TSK indicates what kind of template declaration (if any) is being
1696 declared. TSK_TEMPLATE indicates that the declaration given by
1697 DECL, though a FUNCTION_DECL, has template parameters, and is
1698 therefore a template function.
1700 The template args (those explicitly specified and those deduced)
1701 are output in a newly created vector *TARGS_OUT.
1703 If it is impossible to determine the result, an error message is
1704 issued. The error_mark_node is returned to indicate failure. */
1707 determine_specialization (tree template_id,
1710 int need_member_template,
1716 tree explicit_targs;
1717 tree candidates = NULL_TREE;
1718 /* A TREE_LIST of templates of which DECL may be a specialization.
1719 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1720 corresponding TREE_PURPOSE is the set of template arguments that,
1721 when used to instantiate the template, would produce a function
1722 with the signature of DECL. */
1723 tree templates = NULL_TREE;
1725 struct cp_binding_level *b;
1727 *targs_out = NULL_TREE;
1729 if (template_id == error_mark_node || decl == error_mark_node)
1730 return error_mark_node;
1732 fns = TREE_OPERAND (template_id, 0);
1733 explicit_targs = TREE_OPERAND (template_id, 1);
1735 if (fns == error_mark_node)
1736 return error_mark_node;
1738 /* Check for baselinks. */
1739 if (BASELINK_P (fns))
1740 fns = BASELINK_FUNCTIONS (fns);
1742 if (!is_overloaded_fn (fns))
1744 error ("%qD is not a function template", fns);
1745 return error_mark_node;
1748 /* Count the number of template headers specified for this
1751 for (b = current_binding_level;
1752 b->kind == sk_template_parms;
1756 for (; fns; fns = OVL_NEXT (fns))
1758 tree fn = OVL_CURRENT (fns);
1760 if (TREE_CODE (fn) == TEMPLATE_DECL)
1762 tree decl_arg_types;
1765 /* In case of explicit specialization, we need to check if
1766 the number of template headers appearing in the specialization
1767 is correct. This is usually done in check_explicit_specialization,
1768 but the check done there cannot be exhaustive when specializing
1769 member functions. Consider the following code:
1771 template <> void A<int>::f(int);
1772 template <> template <> void A<int>::f(int);
1774 Assuming that A<int> is not itself an explicit specialization
1775 already, the first line specializes "f" which is a non-template
1776 member function, whilst the second line specializes "f" which
1777 is a template member function. So both lines are syntactically
1778 correct, and check_explicit_specialization does not reject
1781 Here, we can do better, as we are matching the specialization
1782 against the declarations. We count the number of template
1783 headers, and we check if they match TEMPLATE_COUNT + 1
1784 (TEMPLATE_COUNT is the number of qualifying template classes,
1785 plus there must be another header for the member template
1788 Notice that if header_count is zero, this is not a
1789 specialization but rather a template instantiation, so there
1790 is no check we can perform here. */
1791 if (header_count && header_count != template_count + 1)
1794 /* Check that the number of template arguments at the
1795 innermost level for DECL is the same as for FN. */
1796 if (current_binding_level->kind == sk_template_parms
1797 && !current_binding_level->explicit_spec_p
1798 && (TREE_VEC_LENGTH (DECL_INNERMOST_TEMPLATE_PARMS (fn))
1799 != TREE_VEC_LENGTH (INNERMOST_TEMPLATE_PARMS
1800 (current_template_parms))))
1803 /* DECL might be a specialization of FN. */
1804 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1805 fn_arg_types = TYPE_ARG_TYPES (TREE_TYPE (fn));
1807 /* For a non-static member function, we need to make sure
1808 that the const qualification is the same. Since
1809 get_bindings does not try to merge the "this" parameter,
1810 we must do the comparison explicitly. */
1811 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
1812 && !same_type_p (TREE_VALUE (fn_arg_types),
1813 TREE_VALUE (decl_arg_types)))
1816 /* Skip the "this" parameter and, for constructors of
1817 classes with virtual bases, the VTT parameter. A
1818 full specialization of a constructor will have a VTT
1819 parameter, but a template never will. */
1821 = skip_artificial_parms_for (decl, decl_arg_types);
1823 = skip_artificial_parms_for (fn, fn_arg_types);
1825 /* Check that the number of function parameters matches.
1827 template <class T> void f(int i = 0);
1828 template <> void f<int>();
1829 The specialization f<int> is invalid but is not caught
1830 by get_bindings below. */
1831 if (list_length (fn_arg_types) != list_length (decl_arg_types))
1834 /* Function templates cannot be specializations; there are
1835 no partial specializations of functions. Therefore, if
1836 the type of DECL does not match FN, there is no
1838 if (tsk == tsk_template)
1840 if (compparms (fn_arg_types, decl_arg_types))
1841 candidates = tree_cons (NULL_TREE, fn, candidates);
1845 /* See whether this function might be a specialization of this
1847 targs = get_bindings (fn, decl, explicit_targs, /*check_ret=*/true);
1850 /* We cannot deduce template arguments that when used to
1851 specialize TMPL will produce DECL. */
1854 /* Save this template, and the arguments deduced. */
1855 templates = tree_cons (targs, fn, templates);
1857 else if (need_member_template)
1858 /* FN is an ordinary member function, and we need a
1859 specialization of a member template. */
1861 else if (TREE_CODE (fn) != FUNCTION_DECL)
1862 /* We can get IDENTIFIER_NODEs here in certain erroneous
1865 else if (!DECL_FUNCTION_MEMBER_P (fn))
1866 /* This is just an ordinary non-member function. Nothing can
1867 be a specialization of that. */
1869 else if (DECL_ARTIFICIAL (fn))
1870 /* Cannot specialize functions that are created implicitly. */
1874 tree decl_arg_types;
1876 /* This is an ordinary member function. However, since
1877 we're here, we can assume it's enclosing class is a
1878 template class. For example,
1880 template <typename T> struct S { void f(); };
1881 template <> void S<int>::f() {}
1883 Here, S<int>::f is a non-template, but S<int> is a
1884 template class. If FN has the same type as DECL, we
1885 might be in business. */
1887 if (!DECL_TEMPLATE_INFO (fn))
1888 /* Its enclosing class is an explicit specialization
1889 of a template class. This is not a candidate. */
1892 if (!same_type_p (TREE_TYPE (TREE_TYPE (decl)),
1893 TREE_TYPE (TREE_TYPE (fn))))
1894 /* The return types differ. */
1897 /* Adjust the type of DECL in case FN is a static member. */
1898 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1899 if (DECL_STATIC_FUNCTION_P (fn)
1900 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1901 decl_arg_types = TREE_CHAIN (decl_arg_types);
1903 if (compparms (TYPE_ARG_TYPES (TREE_TYPE (fn)),
1906 candidates = tree_cons (NULL_TREE, fn, candidates);
1910 if (templates && TREE_CHAIN (templates))
1916 It is possible for a specialization with a given function
1917 signature to be instantiated from more than one function
1918 template. In such cases, explicit specification of the
1919 template arguments must be used to uniquely identify the
1920 function template specialization being specialized.
1922 Note that here, there's no suggestion that we're supposed to
1923 determine which of the candidate templates is most
1924 specialized. However, we, also have:
1928 Partial ordering of overloaded function template
1929 declarations is used in the following contexts to select
1930 the function template to which a function template
1931 specialization refers:
1933 -- when an explicit specialization refers to a function
1936 So, we do use the partial ordering rules, at least for now.
1937 This extension can only serve to make invalid programs valid,
1938 so it's safe. And, there is strong anecdotal evidence that
1939 the committee intended the partial ordering rules to apply;
1940 the EDG front end has that behavior, and John Spicer claims
1941 that the committee simply forgot to delete the wording in
1942 [temp.expl.spec]. */
1943 tree tmpl = most_specialized_instantiation (templates);
1944 if (tmpl != error_mark_node)
1947 TREE_CHAIN (templates) = NULL_TREE;
1951 if (templates == NULL_TREE && candidates == NULL_TREE)
1953 error ("template-id %qD for %q+D does not match any template "
1954 "declaration", template_id, decl);
1955 if (header_count && header_count != template_count + 1)
1956 inform (input_location, "saw %d %<template<>%>, need %d for "
1957 "specializing a member function template",
1958 header_count, template_count + 1);
1959 return error_mark_node;
1961 else if ((templates && TREE_CHAIN (templates))
1962 || (candidates && TREE_CHAIN (candidates))
1963 || (templates && candidates))
1965 error ("ambiguous template specialization %qD for %q+D",
1967 candidates = chainon (candidates, templates);
1968 print_candidates (candidates);
1969 return error_mark_node;
1972 /* We have one, and exactly one, match. */
1975 tree fn = TREE_VALUE (candidates);
1976 *targs_out = copy_node (DECL_TI_ARGS (fn));
1977 /* DECL is a re-declaration or partial instantiation of a template
1979 if (TREE_CODE (fn) == TEMPLATE_DECL)
1981 /* It was a specialization of an ordinary member function in a
1983 return DECL_TI_TEMPLATE (fn);
1986 /* It was a specialization of a template. */
1987 targs = DECL_TI_ARGS (DECL_TEMPLATE_RESULT (TREE_VALUE (templates)));
1988 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (targs))
1990 *targs_out = copy_node (targs);
1991 SET_TMPL_ARGS_LEVEL (*targs_out,
1992 TMPL_ARGS_DEPTH (*targs_out),
1993 TREE_PURPOSE (templates));
1996 *targs_out = TREE_PURPOSE (templates);
1997 return TREE_VALUE (templates);
2000 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2001 but with the default argument values filled in from those in the
2005 copy_default_args_to_explicit_spec_1 (tree spec_types,
2008 tree new_spec_types;
2013 if (spec_types == void_list_node)
2014 return void_list_node;
2016 /* Substitute into the rest of the list. */
2018 copy_default_args_to_explicit_spec_1 (TREE_CHAIN (spec_types),
2019 TREE_CHAIN (tmpl_types));
2021 /* Add the default argument for this parameter. */
2022 return hash_tree_cons (TREE_PURPOSE (tmpl_types),
2023 TREE_VALUE (spec_types),
2027 /* DECL is an explicit specialization. Replicate default arguments
2028 from the template it specializes. (That way, code like:
2030 template <class T> void f(T = 3);
2031 template <> void f(double);
2034 works, as required.) An alternative approach would be to look up
2035 the correct default arguments at the call-site, but this approach
2036 is consistent with how implicit instantiations are handled. */
2039 copy_default_args_to_explicit_spec (tree decl)
2044 tree new_spec_types;
2048 tree object_type = NULL_TREE;
2049 tree in_charge = NULL_TREE;
2050 tree vtt = NULL_TREE;
2052 /* See if there's anything we need to do. */
2053 tmpl = DECL_TI_TEMPLATE (decl);
2054 tmpl_types = TYPE_ARG_TYPES (TREE_TYPE (DECL_TEMPLATE_RESULT (tmpl)));
2055 for (t = tmpl_types; t; t = TREE_CHAIN (t))
2056 if (TREE_PURPOSE (t))
2061 old_type = TREE_TYPE (decl);
2062 spec_types = TYPE_ARG_TYPES (old_type);
2064 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2066 /* Remove the this pointer, but remember the object's type for
2068 object_type = TREE_TYPE (TREE_VALUE (spec_types));
2069 spec_types = TREE_CHAIN (spec_types);
2070 tmpl_types = TREE_CHAIN (tmpl_types);
2072 if (DECL_HAS_IN_CHARGE_PARM_P (decl))
2074 /* DECL may contain more parameters than TMPL due to the extra
2075 in-charge parameter in constructors and destructors. */
2076 in_charge = spec_types;
2077 spec_types = TREE_CHAIN (spec_types);
2079 if (DECL_HAS_VTT_PARM_P (decl))
2082 spec_types = TREE_CHAIN (spec_types);
2086 /* Compute the merged default arguments. */
2088 copy_default_args_to_explicit_spec_1 (spec_types, tmpl_types);
2090 /* Compute the new FUNCTION_TYPE. */
2094 new_spec_types = hash_tree_cons (TREE_PURPOSE (vtt),
2099 /* Put the in-charge parameter back. */
2100 new_spec_types = hash_tree_cons (TREE_PURPOSE (in_charge),
2101 TREE_VALUE (in_charge),
2104 new_type = build_method_type_directly (object_type,
2105 TREE_TYPE (old_type),
2109 new_type = build_function_type (TREE_TYPE (old_type),
2111 new_type = cp_build_type_attribute_variant (new_type,
2112 TYPE_ATTRIBUTES (old_type));
2113 new_type = build_exception_variant (new_type,
2114 TYPE_RAISES_EXCEPTIONS (old_type));
2115 TREE_TYPE (decl) = new_type;
2118 /* Check to see if the function just declared, as indicated in
2119 DECLARATOR, and in DECL, is a specialization of a function
2120 template. We may also discover that the declaration is an explicit
2121 instantiation at this point.
2123 Returns DECL, or an equivalent declaration that should be used
2124 instead if all goes well. Issues an error message if something is
2125 amiss. Returns error_mark_node if the error is not easily
2128 FLAGS is a bitmask consisting of the following flags:
2130 2: The function has a definition.
2131 4: The function is a friend.
2133 The TEMPLATE_COUNT is the number of references to qualifying
2134 template classes that appeared in the name of the function. For
2137 template <class T> struct S { void f(); };
2140 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2141 classes are not counted in the TEMPLATE_COUNT, so that in
2143 template <class T> struct S {};
2144 template <> struct S<int> { void f(); }
2145 template <> void S<int>::f();
2147 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2148 invalid; there should be no template <>.)
2150 If the function is a specialization, it is marked as such via
2151 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2152 is set up correctly, and it is added to the list of specializations
2153 for that template. */
2156 check_explicit_specialization (tree declarator,
2161 int have_def = flags & 2;
2162 int is_friend = flags & 4;
2163 int specialization = 0;
2164 int explicit_instantiation = 0;
2165 int member_specialization = 0;
2166 tree ctype = DECL_CLASS_CONTEXT (decl);
2167 tree dname = DECL_NAME (decl);
2172 if (!processing_specialization)
2175 tsk = tsk_excessive_parms;
2178 tsk = current_tmpl_spec_kind (template_count);
2183 if (processing_specialization)
2186 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2188 else if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2191 /* This could be something like:
2193 template <class T> void f(T);
2194 class S { friend void f<>(int); } */
2198 /* This case handles bogus declarations like template <>
2199 template <class T> void f<int>(); */
2201 error ("template-id %qD in declaration of primary template",
2208 case tsk_invalid_member_spec:
2209 /* The error has already been reported in
2210 check_specialization_scope. */
2211 return error_mark_node;
2213 case tsk_invalid_expl_inst:
2214 error ("template parameter list used in explicit instantiation");
2220 error ("definition provided for explicit instantiation");
2222 explicit_instantiation = 1;
2225 case tsk_excessive_parms:
2226 case tsk_insufficient_parms:
2227 if (tsk == tsk_excessive_parms)
2228 error ("too many template parameter lists in declaration of %qD",
2230 else if (template_header_count)
2231 error("too few template parameter lists in declaration of %qD", decl);
2233 error("explicit specialization of %qD must be introduced by "
2234 "%<template <>%>", decl);
2238 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2240 member_specialization = 1;
2246 if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2248 /* This case handles bogus declarations like template <>
2249 template <class T> void f<int>(); */
2251 if (uses_template_parms (declarator))
2252 error ("function template partial specialization %qD "
2253 "is not allowed", declarator);
2255 error ("template-id %qD in declaration of primary template",
2260 if (ctype && CLASSTYPE_TEMPLATE_INSTANTIATION (ctype))
2261 /* This is a specialization of a member template, without
2262 specialization the containing class. Something like:
2264 template <class T> struct S {
2265 template <class U> void f (U);
2267 template <> template <class U> void S<int>::f(U) {}
2269 That's a specialization -- but of the entire template. */
2277 if (specialization || member_specialization)
2279 tree t = TYPE_ARG_TYPES (TREE_TYPE (decl));
2280 for (; t; t = TREE_CHAIN (t))
2281 if (TREE_PURPOSE (t))
2283 permerror (input_location,
2284 "default argument specified in explicit specialization");
2289 if (specialization || member_specialization || explicit_instantiation)
2291 tree tmpl = NULL_TREE;
2292 tree targs = NULL_TREE;
2294 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2295 if (TREE_CODE (declarator) != TEMPLATE_ID_EXPR)
2299 gcc_assert (TREE_CODE (declarator) == IDENTIFIER_NODE);
2304 /* If there is no class context, the explicit instantiation
2305 must be at namespace scope. */
2306 gcc_assert (DECL_NAMESPACE_SCOPE_P (decl));
2308 /* Find the namespace binding, using the declaration
2310 fns = lookup_qualified_name (CP_DECL_CONTEXT (decl), dname,
2312 if (fns == error_mark_node || !is_overloaded_fn (fns))
2314 error ("%qD is not a template function", dname);
2315 fns = error_mark_node;
2319 tree fn = OVL_CURRENT (fns);
2320 if (!is_associated_namespace (CP_DECL_CONTEXT (decl),
2321 CP_DECL_CONTEXT (fn)))
2322 error ("%qD is not declared in %qD",
2323 decl, current_namespace);
2327 declarator = lookup_template_function (fns, NULL_TREE);
2330 if (declarator == error_mark_node)
2331 return error_mark_node;
2333 if (ctype != NULL_TREE && TYPE_BEING_DEFINED (ctype))
2335 if (!explicit_instantiation)
2336 /* A specialization in class scope. This is invalid,
2337 but the error will already have been flagged by
2338 check_specialization_scope. */
2339 return error_mark_node;
2342 /* It's not valid to write an explicit instantiation in
2345 class C { template void f(); }
2347 This case is caught by the parser. However, on
2350 template class C { void f(); };
2352 (which is invalid) we can get here. The error will be
2359 else if (ctype != NULL_TREE
2360 && (TREE_CODE (TREE_OPERAND (declarator, 0)) ==
2363 /* Find the list of functions in ctype that have the same
2364 name as the declared function. */
2365 tree name = TREE_OPERAND (declarator, 0);
2366 tree fns = NULL_TREE;
2369 if (constructor_name_p (name, ctype))
2371 int is_constructor = DECL_CONSTRUCTOR_P (decl);
2373 if (is_constructor ? !TYPE_HAS_USER_CONSTRUCTOR (ctype)
2374 : !CLASSTYPE_DESTRUCTORS (ctype))
2376 /* From [temp.expl.spec]:
2378 If such an explicit specialization for the member
2379 of a class template names an implicitly-declared
2380 special member function (clause _special_), the
2381 program is ill-formed.
2383 Similar language is found in [temp.explicit]. */
2384 error ("specialization of implicitly-declared special member function");
2385 return error_mark_node;
2388 name = is_constructor ? ctor_identifier : dtor_identifier;
2391 if (!DECL_CONV_FN_P (decl))
2393 idx = lookup_fnfields_1 (ctype, name);
2395 fns = VEC_index (tree, CLASSTYPE_METHOD_VEC (ctype), idx);
2399 VEC(tree,gc) *methods;
2402 /* For a type-conversion operator, we cannot do a
2403 name-based lookup. We might be looking for `operator
2404 int' which will be a specialization of `operator T'.
2405 So, we find *all* the conversion operators, and then
2406 select from them. */
2409 methods = CLASSTYPE_METHOD_VEC (ctype);
2411 for (idx = CLASSTYPE_FIRST_CONVERSION_SLOT;
2412 VEC_iterate (tree, methods, idx, ovl);
2415 if (!DECL_CONV_FN_P (OVL_CURRENT (ovl)))
2416 /* There are no more conversion functions. */
2419 /* Glue all these conversion functions together
2420 with those we already have. */
2421 for (; ovl; ovl = OVL_NEXT (ovl))
2422 fns = ovl_cons (OVL_CURRENT (ovl), fns);
2426 if (fns == NULL_TREE)
2428 error ("no member function %qD declared in %qT", name, ctype);
2429 return error_mark_node;
2432 TREE_OPERAND (declarator, 0) = fns;
2435 /* Figure out what exactly is being specialized at this point.
2436 Note that for an explicit instantiation, even one for a
2437 member function, we cannot tell apriori whether the
2438 instantiation is for a member template, or just a member
2439 function of a template class. Even if a member template is
2440 being instantiated, the member template arguments may be
2441 elided if they can be deduced from the rest of the
2443 tmpl = determine_specialization (declarator, decl,
2445 member_specialization,
2449 if (!tmpl || tmpl == error_mark_node)
2450 /* We couldn't figure out what this declaration was
2452 return error_mark_node;
2455 tree gen_tmpl = most_general_template (tmpl);
2457 if (explicit_instantiation)
2459 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2460 is done by do_decl_instantiation later. */
2462 int arg_depth = TMPL_ARGS_DEPTH (targs);
2463 int parm_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
2465 if (arg_depth > parm_depth)
2467 /* If TMPL is not the most general template (for
2468 example, if TMPL is a friend template that is
2469 injected into namespace scope), then there will
2470 be too many levels of TARGS. Remove some of them
2475 new_targs = make_tree_vec (parm_depth);
2476 for (i = arg_depth - parm_depth; i < arg_depth; ++i)
2477 TREE_VEC_ELT (new_targs, i - (arg_depth - parm_depth))
2478 = TREE_VEC_ELT (targs, i);
2482 return instantiate_template (tmpl, targs, tf_error);
2485 /* If we thought that the DECL was a member function, but it
2486 turns out to be specializing a static member function,
2487 make DECL a static member function as well. */
2488 if (DECL_STATIC_FUNCTION_P (tmpl)
2489 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2490 revert_static_member_fn (decl);
2492 /* If this is a specialization of a member template of a
2493 template class, we want to return the TEMPLATE_DECL, not
2494 the specialization of it. */
2495 if (tsk == tsk_template)
2497 tree result = DECL_TEMPLATE_RESULT (tmpl);
2498 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
2499 DECL_INITIAL (result) = NULL_TREE;
2503 DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl);
2504 DECL_SOURCE_LOCATION (result)
2505 = DECL_SOURCE_LOCATION (decl);
2506 /* We want to use the argument list specified in the
2507 definition, not in the original declaration. */
2508 DECL_ARGUMENTS (result) = DECL_ARGUMENTS (decl);
2509 for (parm = DECL_ARGUMENTS (result); parm;
2510 parm = TREE_CHAIN (parm))
2511 DECL_CONTEXT (parm) = result;
2513 return register_specialization (tmpl, gen_tmpl, targs,
2517 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2518 DECL_TEMPLATE_INFO (decl) = build_template_info (tmpl, targs);
2520 /* Inherit default function arguments from the template
2521 DECL is specializing. */
2522 copy_default_args_to_explicit_spec (decl);
2524 /* This specialization has the same protection as the
2525 template it specializes. */
2526 TREE_PRIVATE (decl) = TREE_PRIVATE (gen_tmpl);
2527 TREE_PROTECTED (decl) = TREE_PROTECTED (gen_tmpl);
2529 /* 7.1.1-1 [dcl.stc]
2531 A storage-class-specifier shall not be specified in an
2532 explicit specialization...
2534 The parser rejects these, so unless action is taken here,
2535 explicit function specializations will always appear with
2538 The action recommended by the C++ CWG in response to C++
2539 defect report 605 is to make the storage class and linkage
2540 of the explicit specialization match the templated function:
2542 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2544 if (tsk == tsk_expl_spec && DECL_FUNCTION_TEMPLATE_P (gen_tmpl))
2546 tree tmpl_func = DECL_TEMPLATE_RESULT (gen_tmpl);
2547 gcc_assert (TREE_CODE (tmpl_func) == FUNCTION_DECL);
2549 /* This specialization has the same linkage and visibility as
2550 the function template it specializes. */
2551 TREE_PUBLIC (decl) = TREE_PUBLIC (tmpl_func);
2552 if (! TREE_PUBLIC (decl))
2554 DECL_INTERFACE_KNOWN (decl) = 1;
2555 DECL_NOT_REALLY_EXTERN (decl) = 1;
2557 DECL_THIS_STATIC (decl) = DECL_THIS_STATIC (tmpl_func);
2558 if (DECL_VISIBILITY_SPECIFIED (tmpl_func))
2560 DECL_VISIBILITY_SPECIFIED (decl) = 1;
2561 DECL_VISIBILITY (decl) = DECL_VISIBILITY (tmpl_func);
2565 /* If DECL is a friend declaration, declared using an
2566 unqualified name, the namespace associated with DECL may
2567 have been set incorrectly. For example, in:
2569 template <typename T> void f(T);
2571 struct S { friend void f<int>(int); }
2574 we will have set the DECL_CONTEXT for the friend
2575 declaration to N, rather than to the global namespace. */
2576 if (DECL_NAMESPACE_SCOPE_P (decl))
2577 DECL_CONTEXT (decl) = DECL_CONTEXT (tmpl);
2579 if (is_friend && !have_def)
2580 /* This is not really a declaration of a specialization.
2581 It's just the name of an instantiation. But, it's not
2582 a request for an instantiation, either. */
2583 SET_DECL_IMPLICIT_INSTANTIATION (decl);
2584 else if (DECL_CONSTRUCTOR_P (decl) || DECL_DESTRUCTOR_P (decl))
2585 /* This is indeed a specialization. In case of constructors
2586 and destructors, we need in-charge and not-in-charge
2587 versions in V3 ABI. */
2588 clone_function_decl (decl, /*update_method_vec_p=*/0);
2590 /* Register this specialization so that we can find it
2592 decl = register_specialization (decl, gen_tmpl, targs, is_friend, 0);
2599 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2600 parameters. These are represented in the same format used for
2601 DECL_TEMPLATE_PARMS. */
2604 comp_template_parms (const_tree parms1, const_tree parms2)
2609 if (parms1 == parms2)
2612 for (p1 = parms1, p2 = parms2;
2613 p1 != NULL_TREE && p2 != NULL_TREE;
2614 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2))
2616 tree t1 = TREE_VALUE (p1);
2617 tree t2 = TREE_VALUE (p2);
2620 gcc_assert (TREE_CODE (t1) == TREE_VEC);
2621 gcc_assert (TREE_CODE (t2) == TREE_VEC);
2623 if (TREE_VEC_LENGTH (t1) != TREE_VEC_LENGTH (t2))
2626 for (i = 0; i < TREE_VEC_LENGTH (t2); ++i)
2628 tree parm1 = TREE_VALUE (TREE_VEC_ELT (t1, i));
2629 tree parm2 = TREE_VALUE (TREE_VEC_ELT (t2, i));
2631 /* If either of the template parameters are invalid, assume
2632 they match for the sake of error recovery. */
2633 if (parm1 == error_mark_node || parm2 == error_mark_node)
2636 if (TREE_CODE (parm1) != TREE_CODE (parm2))
2639 if (TREE_CODE (parm1) == TEMPLATE_TYPE_PARM
2640 && (TEMPLATE_TYPE_PARAMETER_PACK (parm1)
2641 == TEMPLATE_TYPE_PARAMETER_PACK (parm2)))
2643 else if (!same_type_p (TREE_TYPE (parm1), TREE_TYPE (parm2)))
2648 if ((p1 != NULL_TREE) != (p2 != NULL_TREE))
2649 /* One set of parameters has more parameters lists than the
2656 /* Determine whether PARM is a parameter pack. */
2659 template_parameter_pack_p (const_tree parm)
2661 /* Determine if we have a non-type template parameter pack. */
2662 if (TREE_CODE (parm) == PARM_DECL)
2663 return (DECL_TEMPLATE_PARM_P (parm)
2664 && TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)));
2666 /* If this is a list of template parameters, we could get a
2667 TYPE_DECL or a TEMPLATE_DECL. */
2668 if (TREE_CODE (parm) == TYPE_DECL || TREE_CODE (parm) == TEMPLATE_DECL)
2669 parm = TREE_TYPE (parm);
2671 return ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
2672 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM)
2673 && TEMPLATE_TYPE_PARAMETER_PACK (parm));
2676 /* Determine if T is a function parameter pack. */
2679 function_parameter_pack_p (const_tree t)
2681 if (t && TREE_CODE (t) == PARM_DECL)
2682 return FUNCTION_PARAMETER_PACK_P (t);
2686 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2687 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2690 get_function_template_decl (const_tree primary_func_tmpl_inst)
2692 if (! primary_func_tmpl_inst
2693 || TREE_CODE (primary_func_tmpl_inst) != FUNCTION_DECL
2694 || ! primary_template_instantiation_p (primary_func_tmpl_inst))
2697 return DECL_TEMPLATE_RESULT (DECL_TI_TEMPLATE (primary_func_tmpl_inst));
2700 /* Return true iff the function parameter PARAM_DECL was expanded
2701 from the function parameter pack PACK. */
2704 function_parameter_expanded_from_pack_p (tree param_decl, tree pack)
2706 if (DECL_ARTIFICIAL (param_decl)
2707 || !function_parameter_pack_p (pack))
2710 gcc_assert (DECL_NAME (param_decl) && DECL_NAME (pack));
2712 /* The parameter pack and its pack arguments have the same
2714 return DECL_PARM_INDEX (pack) == DECL_PARM_INDEX (param_decl);
2717 /* Determine whether ARGS describes a variadic template args list,
2718 i.e., one that is terminated by a template argument pack. */
2721 template_args_variadic_p (tree args)
2726 if (args == NULL_TREE)
2729 args = INNERMOST_TEMPLATE_ARGS (args);
2730 nargs = TREE_VEC_LENGTH (args);
2735 last_parm = TREE_VEC_ELT (args, nargs - 1);
2737 return ARGUMENT_PACK_P (last_parm);
2740 /* Generate a new name for the parameter pack name NAME (an
2741 IDENTIFIER_NODE) that incorporates its */
2744 make_ith_pack_parameter_name (tree name, int i)
2746 /* Munge the name to include the parameter index. */
2747 #define NUMBUF_LEN 128
2748 char numbuf[NUMBUF_LEN];
2752 snprintf (numbuf, NUMBUF_LEN, "%i", i);
2753 newname_len = IDENTIFIER_LENGTH (name)
2754 + strlen (numbuf) + 2;
2755 newname = (char*)alloca (newname_len);
2756 snprintf (newname, newname_len,
2757 "%s#%i", IDENTIFIER_POINTER (name), i);
2758 return get_identifier (newname);
2761 /* Return true if T is a primary function
2762 or class template instantiation. */
2765 primary_template_instantiation_p (const_tree t)
2770 if (TREE_CODE (t) == FUNCTION_DECL)
2771 return DECL_LANG_SPECIFIC (t)
2772 && DECL_TEMPLATE_INSTANTIATION (t)
2773 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (t));
2774 else if (CLASS_TYPE_P (t))
2775 return CLASSTYPE_TEMPLATE_INSTANTIATION (t)
2776 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (t));
2780 /* Return true if PARM is a template template parameter. */
2783 template_template_parameter_p (const_tree parm)
2785 return DECL_TEMPLATE_TEMPLATE_PARM_P (parm);
2788 /* Return the template parameters of T if T is a
2789 primary template instantiation, NULL otherwise. */
2792 get_primary_template_innermost_parameters (const_tree t)
2794 tree parms = NULL, template_info = NULL;
2796 if ((template_info = get_template_info (t))
2797 && primary_template_instantiation_p (t))
2798 parms = INNERMOST_TEMPLATE_PARMS
2799 (DECL_TEMPLATE_PARMS (TI_TEMPLATE (template_info)));
2804 /* Returns the template arguments of T if T is a template instantiation,
2808 get_template_innermost_arguments (const_tree t)
2810 tree args = NULL, template_info = NULL;
2812 if ((template_info = get_template_info (t))
2813 && TI_ARGS (template_info))
2814 args = INNERMOST_TEMPLATE_ARGS (TI_ARGS (template_info));
2819 /* Return the argument pack elements of T if T is a template argument pack,
2823 get_template_argument_pack_elems (const_tree t)
2825 if (TREE_CODE (t) != TYPE_ARGUMENT_PACK
2826 && TREE_CODE (t) != NONTYPE_ARGUMENT_PACK)
2829 return ARGUMENT_PACK_ARGS (t);
2832 /* Structure used to track the progress of find_parameter_packs_r. */
2833 struct find_parameter_pack_data
2835 /* TREE_LIST that will contain all of the parameter packs found by
2837 tree* parameter_packs;
2839 /* Set of AST nodes that have been visited by the traversal. */
2840 struct pointer_set_t *visited;
2843 /* Identifies all of the argument packs that occur in a template
2844 argument and appends them to the TREE_LIST inside DATA, which is a
2845 find_parameter_pack_data structure. This is a subroutine of
2846 make_pack_expansion and uses_parameter_packs. */
2848 find_parameter_packs_r (tree *tp, int *walk_subtrees, void* data)
2851 struct find_parameter_pack_data* ppd =
2852 (struct find_parameter_pack_data*)data;
2853 bool parameter_pack_p = false;
2855 /* Identify whether this is a parameter pack or not. */
2856 switch (TREE_CODE (t))
2858 case TEMPLATE_PARM_INDEX:
2859 if (TEMPLATE_PARM_PARAMETER_PACK (t))
2860 parameter_pack_p = true;
2863 case TEMPLATE_TYPE_PARM:
2864 case TEMPLATE_TEMPLATE_PARM:
2865 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
2866 parameter_pack_p = true;
2870 if (FUNCTION_PARAMETER_PACK_P (t))
2872 /* We don't want to walk into the type of a PARM_DECL,
2873 because we don't want to see the type parameter pack. */
2875 parameter_pack_p = true;
2880 /* Not a parameter pack. */
2884 if (parameter_pack_p)
2886 /* Add this parameter pack to the list. */
2887 *ppd->parameter_packs = tree_cons (NULL_TREE, t, *ppd->parameter_packs);
2891 cp_walk_tree (&TYPE_CONTEXT (t),
2892 &find_parameter_packs_r, ppd, ppd->visited);
2894 /* This switch statement will return immediately if we don't find a
2896 switch (TREE_CODE (t))
2898 case TEMPLATE_PARM_INDEX:
2901 case BOUND_TEMPLATE_TEMPLATE_PARM:
2902 /* Check the template itself. */
2903 cp_walk_tree (&TREE_TYPE (TYPE_TI_TEMPLATE (t)),
2904 &find_parameter_packs_r, ppd, ppd->visited);
2905 /* Check the template arguments. */
2906 cp_walk_tree (&TYPE_TI_ARGS (t), &find_parameter_packs_r, ppd,
2911 case TEMPLATE_TYPE_PARM:
2912 case TEMPLATE_TEMPLATE_PARM:
2919 if (TYPE_PTRMEMFUNC_P (t))
2925 if (TYPE_TEMPLATE_INFO (t))
2926 cp_walk_tree (&TI_ARGS (TYPE_TEMPLATE_INFO (t)),
2927 &find_parameter_packs_r, ppd, ppd->visited);
2933 cp_walk_tree (&TREE_TYPE (t),
2934 &find_parameter_packs_r, ppd, ppd->visited);
2938 cp_walk_tree (&TYPENAME_TYPE_FULLNAME (t), &find_parameter_packs_r,
2943 case TYPE_PACK_EXPANSION:
2944 case EXPR_PACK_EXPANSION:
2949 cp_walk_tree (&TYPE_MAX_VALUE (t), &find_parameter_packs_r,
2954 case IDENTIFIER_NODE:
2955 cp_walk_tree (&TREE_TYPE (t), &find_parameter_packs_r, ppd,
2967 /* Determines if the expression or type T uses any parameter packs. */
2969 uses_parameter_packs (tree t)
2971 tree parameter_packs = NULL_TREE;
2972 struct find_parameter_pack_data ppd;
2973 ppd.parameter_packs = ¶meter_packs;
2974 ppd.visited = pointer_set_create ();
2975 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
2976 pointer_set_destroy (ppd.visited);
2977 return parameter_packs != NULL_TREE;
2980 /* Turn ARG, which may be an expression, type, or a TREE_LIST
2981 representation a base-class initializer into a parameter pack
2982 expansion. If all goes well, the resulting node will be an
2983 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
2986 make_pack_expansion (tree arg)
2989 tree parameter_packs = NULL_TREE;
2990 bool for_types = false;
2991 struct find_parameter_pack_data ppd;
2993 if (!arg || arg == error_mark_node)
2996 if (TREE_CODE (arg) == TREE_LIST)
2998 /* The only time we will see a TREE_LIST here is for a base
2999 class initializer. In this case, the TREE_PURPOSE will be a
3000 _TYPE node (representing the base class expansion we're
3001 initializing) and the TREE_VALUE will be a TREE_LIST
3002 containing the initialization arguments.
3004 The resulting expansion looks somewhat different from most
3005 expansions. Rather than returning just one _EXPANSION, we
3006 return a TREE_LIST whose TREE_PURPOSE is a
3007 TYPE_PACK_EXPANSION containing the bases that will be
3008 initialized. The TREE_VALUE will be identical to the
3009 original TREE_VALUE, which is a list of arguments that will
3010 be passed to each base. We do not introduce any new pack
3011 expansion nodes into the TREE_VALUE (although it is possible
3012 that some already exist), because the TREE_PURPOSE and
3013 TREE_VALUE all need to be expanded together with the same
3014 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3015 resulting TREE_PURPOSE will mention the parameter packs in
3016 both the bases and the arguments to the bases. */
3019 tree parameter_packs = NULL_TREE;
3021 /* Determine which parameter packs will be used by the base
3023 ppd.visited = pointer_set_create ();
3024 ppd.parameter_packs = ¶meter_packs;
3025 cp_walk_tree (&TREE_PURPOSE (arg), &find_parameter_packs_r,
3028 if (parameter_packs == NULL_TREE)
3030 error ("base initializer expansion %<%T%> contains no parameter packs", arg);
3031 pointer_set_destroy (ppd.visited);
3032 return error_mark_node;
3035 if (TREE_VALUE (arg) != void_type_node)
3037 /* Collect the sets of parameter packs used in each of the
3038 initialization arguments. */
3039 for (value = TREE_VALUE (arg); value; value = TREE_CHAIN (value))
3041 /* Determine which parameter packs will be expanded in this
3043 cp_walk_tree (&TREE_VALUE (value), &find_parameter_packs_r,
3048 pointer_set_destroy (ppd.visited);
3050 /* Create the pack expansion type for the base type. */
3051 purpose = cxx_make_type (TYPE_PACK_EXPANSION);
3052 SET_PACK_EXPANSION_PATTERN (purpose, TREE_PURPOSE (arg));
3053 PACK_EXPANSION_PARAMETER_PACKS (purpose) = parameter_packs;
3055 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3056 they will rarely be compared to anything. */
3057 SET_TYPE_STRUCTURAL_EQUALITY (purpose);
3059 return tree_cons (purpose, TREE_VALUE (arg), NULL_TREE);
3062 if (TYPE_P (arg) || TREE_CODE (arg) == TEMPLATE_DECL)
3065 /* Build the PACK_EXPANSION_* node. */
3067 ? cxx_make_type (TYPE_PACK_EXPANSION)
3068 : make_node (EXPR_PACK_EXPANSION);
3069 SET_PACK_EXPANSION_PATTERN (result, arg);
3070 if (TREE_CODE (result) == EXPR_PACK_EXPANSION)
3072 /* Propagate type and const-expression information. */
3073 TREE_TYPE (result) = TREE_TYPE (arg);
3074 TREE_CONSTANT (result) = TREE_CONSTANT (arg);
3077 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3078 they will rarely be compared to anything. */
3079 SET_TYPE_STRUCTURAL_EQUALITY (result);
3081 /* Determine which parameter packs will be expanded. */
3082 ppd.parameter_packs = ¶meter_packs;
3083 ppd.visited = pointer_set_create ();
3084 cp_walk_tree (&arg, &find_parameter_packs_r, &ppd, ppd.visited);
3085 pointer_set_destroy (ppd.visited);
3087 /* Make sure we found some parameter packs. */
3088 if (parameter_packs == NULL_TREE)
3091 error ("expansion pattern %<%T%> contains no argument packs", arg);
3093 error ("expansion pattern %<%E%> contains no argument packs", arg);
3094 return error_mark_node;
3096 PACK_EXPANSION_PARAMETER_PACKS (result) = parameter_packs;
3101 /* Checks T for any "bare" parameter packs, which have not yet been
3102 expanded, and issues an error if any are found. This operation can
3103 only be done on full expressions or types (e.g., an expression
3104 statement, "if" condition, etc.), because we could have expressions like:
3106 foo(f(g(h(args)))...)
3108 where "args" is a parameter pack. check_for_bare_parameter_packs
3109 should not be called for the subexpressions args, h(args),
3110 g(h(args)), or f(g(h(args))), because we would produce erroneous
3113 Returns TRUE and emits an error if there were bare parameter packs,
3114 returns FALSE otherwise. */
3116 check_for_bare_parameter_packs (tree t)
3118 tree parameter_packs = NULL_TREE;
3119 struct find_parameter_pack_data ppd;
3121 if (!processing_template_decl || !t || t == error_mark_node)
3124 if (TREE_CODE (t) == TYPE_DECL)
3127 ppd.parameter_packs = ¶meter_packs;
3128 ppd.visited = pointer_set_create ();
3129 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
3130 pointer_set_destroy (ppd.visited);
3132 if (parameter_packs)
3134 error ("parameter packs not expanded with %<...%>:");
3135 while (parameter_packs)
3137 tree pack = TREE_VALUE (parameter_packs);
3138 tree name = NULL_TREE;
3140 if (TREE_CODE (pack) == TEMPLATE_TYPE_PARM
3141 || TREE_CODE (pack) == TEMPLATE_TEMPLATE_PARM)
3142 name = TYPE_NAME (pack);
3143 else if (TREE_CODE (pack) == TEMPLATE_PARM_INDEX)
3144 name = DECL_NAME (TEMPLATE_PARM_DECL (pack));
3146 name = DECL_NAME (pack);
3149 inform (input_location, " %qD", name);
3151 inform (input_location, " <anonymous>");
3153 parameter_packs = TREE_CHAIN (parameter_packs);
3162 /* Expand any parameter packs that occur in the template arguments in
3165 expand_template_argument_pack (tree args)
3167 tree result_args = NULL_TREE;
3168 int in_arg, out_arg = 0, nargs = args ? TREE_VEC_LENGTH (args) : 0;
3169 int num_result_args = -1;
3171 /* First, determine if we need to expand anything, and the number of
3172 slots we'll need. */
3173 for (in_arg = 0; in_arg < nargs; ++in_arg)
3175 tree arg = TREE_VEC_ELT (args, in_arg);
3176 if (arg == NULL_TREE)
3178 if (ARGUMENT_PACK_P (arg))
3180 int num_packed = TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg));
3181 if (num_result_args < 0)
3182 num_result_args = in_arg + num_packed;
3184 num_result_args += num_packed;
3188 if (num_result_args >= 0)
3193 /* If no expansion is necessary, we're done. */
3194 if (num_result_args < 0)
3197 /* Expand arguments. */
3198 result_args = make_tree_vec (num_result_args);
3199 for (in_arg = 0; in_arg < nargs; ++in_arg)
3201 tree arg = TREE_VEC_ELT (args, in_arg);
3202 if (ARGUMENT_PACK_P (arg))
3204 tree packed = ARGUMENT_PACK_ARGS (arg);
3205 int i, num_packed = TREE_VEC_LENGTH (packed);
3206 for (i = 0; i < num_packed; ++i, ++out_arg)
3207 TREE_VEC_ELT (result_args, out_arg) = TREE_VEC_ELT(packed, i);
3211 TREE_VEC_ELT (result_args, out_arg) = arg;
3219 /* Checks if DECL shadows a template parameter.
3221 [temp.local]: A template-parameter shall not be redeclared within its
3222 scope (including nested scopes).
3224 Emits an error and returns TRUE if the DECL shadows a parameter,
3225 returns FALSE otherwise. */
3228 check_template_shadow (tree decl)
3232 /* If we're not in a template, we can't possibly shadow a template
3234 if (!current_template_parms)
3237 /* Figure out what we're shadowing. */
3238 if (TREE_CODE (decl) == OVERLOAD)
3239 decl = OVL_CURRENT (decl);
3240 olddecl = innermost_non_namespace_value (DECL_NAME (decl));
3242 /* If there's no previous binding for this name, we're not shadowing
3243 anything, let alone a template parameter. */
3247 /* If we're not shadowing a template parameter, we're done. Note
3248 that OLDDECL might be an OVERLOAD (or perhaps even an
3249 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3251 if (!DECL_P (olddecl) || !DECL_TEMPLATE_PARM_P (olddecl))
3254 /* We check for decl != olddecl to avoid bogus errors for using a
3255 name inside a class. We check TPFI to avoid duplicate errors for
3256 inline member templates. */
3258 || TEMPLATE_PARMS_FOR_INLINE (current_template_parms))
3261 error ("declaration of %q+#D", decl);
3262 error (" shadows template parm %q+#D", olddecl);
3266 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3267 ORIG_LEVEL, DECL, and TYPE. */
3270 build_template_parm_index (int index,
3276 tree t = make_node (TEMPLATE_PARM_INDEX);
3277 TEMPLATE_PARM_IDX (t) = index;
3278 TEMPLATE_PARM_LEVEL (t) = level;
3279 TEMPLATE_PARM_ORIG_LEVEL (t) = orig_level;
3280 TEMPLATE_PARM_DECL (t) = decl;
3281 TREE_TYPE (t) = type;
3282 TREE_CONSTANT (t) = TREE_CONSTANT (decl);
3283 TREE_READONLY (t) = TREE_READONLY (decl);
3288 /* Find the canonical type parameter for the given template type
3289 parameter. Returns the canonical type parameter, which may be TYPE
3290 if no such parameter existed. */
3292 canonical_type_parameter (tree type)
3295 int idx = TEMPLATE_TYPE_IDX (type);
3296 if (!canonical_template_parms)
3297 canonical_template_parms = VEC_alloc (tree, gc, idx+1);
3299 while (VEC_length (tree, canonical_template_parms) <= (unsigned)idx)
3300 VEC_safe_push (tree, gc, canonical_template_parms, NULL_TREE);
3302 list = VEC_index (tree, canonical_template_parms, idx);
3303 while (list && !comptypes (type, TREE_VALUE (list), COMPARE_STRUCTURAL))
3304 list = TREE_CHAIN (list);
3307 return TREE_VALUE (list);
3310 VEC_replace(tree, canonical_template_parms, idx,
3311 tree_cons (NULL_TREE, type,
3312 VEC_index (tree, canonical_template_parms, idx)));
3317 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3318 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3319 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3320 new one is created. */
3323 reduce_template_parm_level (tree index, tree type, int levels, tree args,
3324 tsubst_flags_t complain)
3326 if (TEMPLATE_PARM_DESCENDANTS (index) == NULL_TREE
3327 || (TEMPLATE_PARM_LEVEL (TEMPLATE_PARM_DESCENDANTS (index))
3328 != TEMPLATE_PARM_LEVEL (index) - levels))
3330 tree orig_decl = TEMPLATE_PARM_DECL (index);
3333 decl = build_decl (DECL_SOURCE_LOCATION (orig_decl),
3334 TREE_CODE (orig_decl), DECL_NAME (orig_decl), type);
3335 TREE_CONSTANT (decl) = TREE_CONSTANT (orig_decl);
3336 TREE_READONLY (decl) = TREE_READONLY (orig_decl);
3337 DECL_ARTIFICIAL (decl) = 1;
3338 SET_DECL_TEMPLATE_PARM_P (decl);
3340 t = build_template_parm_index (TEMPLATE_PARM_IDX (index),
3341 TEMPLATE_PARM_LEVEL (index) - levels,
3342 TEMPLATE_PARM_ORIG_LEVEL (index),
3344 TEMPLATE_PARM_DESCENDANTS (index) = t;
3345 TEMPLATE_PARM_PARAMETER_PACK (t)
3346 = TEMPLATE_PARM_PARAMETER_PACK (index);
3348 /* Template template parameters need this. */
3349 if (TREE_CODE (decl) == TEMPLATE_DECL)
3350 DECL_TEMPLATE_PARMS (decl) = tsubst_template_parms
3351 (DECL_TEMPLATE_PARMS (TEMPLATE_PARM_DECL (index)),
3355 return TEMPLATE_PARM_DESCENDANTS (index);
3358 /* Process information from new template parameter PARM and append it to the
3359 LIST being built. This new parameter is a non-type parameter iff
3360 IS_NON_TYPE is true. This new parameter is a parameter
3361 pack iff IS_PARAMETER_PACK is true. The location of PARM is in
3365 process_template_parm (tree list, location_t parm_loc, tree parm, bool is_non_type,
3366 bool is_parameter_pack)
3373 gcc_assert (TREE_CODE (parm) == TREE_LIST);
3374 defval = TREE_PURPOSE (parm);
3378 tree p = tree_last (list);
3380 if (p && TREE_VALUE (p) != error_mark_node)
3383 if (TREE_CODE (p) == TYPE_DECL || TREE_CODE (p) == TEMPLATE_DECL)
3384 idx = TEMPLATE_TYPE_IDX (TREE_TYPE (p));
3386 idx = TEMPLATE_PARM_IDX (DECL_INITIAL (p));
3396 parm = TREE_VALUE (parm);
3398 SET_DECL_TEMPLATE_PARM_P (parm);
3400 if (TREE_TYPE (parm) == error_mark_node)
3402 err_parm_list = build_tree_list (defval, parm);
3403 TREE_VALUE (err_parm_list) = error_mark_node;
3404 return chainon (list, err_parm_list);
3410 The top-level cv-qualifiers on the template-parameter are
3411 ignored when determining its type. */
3412 TREE_TYPE (parm) = TYPE_MAIN_VARIANT (TREE_TYPE (parm));
3413 if (invalid_nontype_parm_type_p (TREE_TYPE (parm), 1))
3415 err_parm_list = build_tree_list (defval, parm);
3416 TREE_VALUE (err_parm_list) = error_mark_node;
3417 return chainon (list, err_parm_list);
3420 if (uses_parameter_packs (TREE_TYPE (parm)) && !is_parameter_pack)
3422 /* This template parameter is not a parameter pack, but it
3423 should be. Complain about "bare" parameter packs. */
3424 check_for_bare_parameter_packs (TREE_TYPE (parm));
3426 /* Recover by calling this a parameter pack. */
3427 is_parameter_pack = true;
3431 /* A template parameter is not modifiable. */
3432 TREE_CONSTANT (parm) = 1;
3433 TREE_READONLY (parm) = 1;
3434 decl = build_decl (parm_loc,
3435 CONST_DECL, DECL_NAME (parm), TREE_TYPE (parm));
3436 TREE_CONSTANT (decl) = 1;
3437 TREE_READONLY (decl) = 1;
3438 DECL_INITIAL (parm) = DECL_INITIAL (decl)
3439 = build_template_parm_index (idx, processing_template_decl,
3440 processing_template_decl,
3441 decl, TREE_TYPE (parm));
3443 TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))
3444 = is_parameter_pack;
3449 parm = TREE_VALUE (TREE_VALUE (parm));
3451 if (parm && TREE_CODE (parm) == TEMPLATE_DECL)
3453 t = cxx_make_type (TEMPLATE_TEMPLATE_PARM);
3454 /* This is for distinguishing between real templates and template
3455 template parameters */
3456 TREE_TYPE (parm) = t;
3457 TREE_TYPE (DECL_TEMPLATE_RESULT (parm)) = t;
3462 t = cxx_make_type (TEMPLATE_TYPE_PARM);
3463 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3464 decl = build_decl (parm_loc,
3465 TYPE_DECL, parm, t);
3468 TYPE_NAME (t) = decl;
3469 TYPE_STUB_DECL (t) = decl;
3471 TEMPLATE_TYPE_PARM_INDEX (t)
3472 = build_template_parm_index (idx, processing_template_decl,
3473 processing_template_decl,
3474 decl, TREE_TYPE (parm));
3475 TEMPLATE_TYPE_PARAMETER_PACK (t) = is_parameter_pack;
3476 TYPE_CANONICAL (t) = canonical_type_parameter (t);
3478 DECL_ARTIFICIAL (decl) = 1;
3479 SET_DECL_TEMPLATE_PARM_P (decl);
3481 parm = build_tree_list (defval, parm);
3482 return chainon (list, parm);
3485 /* The end of a template parameter list has been reached. Process the
3486 tree list into a parameter vector, converting each parameter into a more
3487 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3491 end_template_parm_list (tree parms)
3495 tree saved_parmlist = make_tree_vec (list_length (parms));
3497 current_template_parms
3498 = tree_cons (size_int (processing_template_decl),
3499 saved_parmlist, current_template_parms);
3501 for (parm = parms, nparms = 0; parm; parm = next, nparms++)
3503 next = TREE_CHAIN (parm);
3504 TREE_VEC_ELT (saved_parmlist, nparms) = parm;
3505 TREE_CHAIN (parm) = NULL_TREE;
3508 --processing_template_parmlist;
3510 return saved_parmlist;
3513 /* end_template_decl is called after a template declaration is seen. */
3516 end_template_decl (void)
3518 reset_specialization ();
3520 if (! processing_template_decl)
3523 /* This matches the pushlevel in begin_template_parm_list. */
3526 --processing_template_decl;
3527 current_template_parms = TREE_CHAIN (current_template_parms);
3530 /* Within the declaration of a template, return all levels of template
3531 parameters that apply. The template parameters are represented as
3532 a TREE_VEC, in the form documented in cp-tree.h for template
3536 current_template_args (void)
3539 tree args = NULL_TREE;
3540 int length = TMPL_PARMS_DEPTH (current_template_parms);
3543 /* If there is only one level of template parameters, we do not
3544 create a TREE_VEC of TREE_VECs. Instead, we return a single
3545 TREE_VEC containing the arguments. */
3547 args = make_tree_vec (length);
3549 for (header = current_template_parms; header; header = TREE_CHAIN (header))
3551 tree a = copy_node (TREE_VALUE (header));
3554 TREE_TYPE (a) = NULL_TREE;
3555 for (i = TREE_VEC_LENGTH (a) - 1; i >= 0; --i)
3557 tree t = TREE_VEC_ELT (a, i);
3559 /* T will be a list if we are called from within a
3560 begin/end_template_parm_list pair, but a vector directly
3561 if within a begin/end_member_template_processing pair. */
3562 if (TREE_CODE (t) == TREE_LIST)
3566 if (!error_operand_p (t))
3568 if (TREE_CODE (t) == TYPE_DECL
3569 || TREE_CODE (t) == TEMPLATE_DECL)
3573 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
3575 /* Turn this argument into a TYPE_ARGUMENT_PACK
3576 with a single element, which expands T. */
3577 tree vec = make_tree_vec (1);
3578 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
3580 t = cxx_make_type (TYPE_ARGUMENT_PACK);
3581 SET_ARGUMENT_PACK_ARGS (t, vec);
3586 t = DECL_INITIAL (t);
3588 if (TEMPLATE_PARM_PARAMETER_PACK (t))
3590 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3591 with a single element, which expands T. */
3592 tree vec = make_tree_vec (1);
3593 tree type = TREE_TYPE (TEMPLATE_PARM_DECL (t));
3594 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
3596 t = make_node (NONTYPE_ARGUMENT_PACK);
3597 SET_ARGUMENT_PACK_ARGS (t, vec);
3598 TREE_TYPE (t) = type;
3601 TREE_VEC_ELT (a, i) = t;
3607 TREE_VEC_ELT (args, --l) = a;
3615 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
3616 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
3617 a member template. Used by push_template_decl below. */
3620 build_template_decl (tree decl, tree parms, bool member_template_p)
3622 tree tmpl = build_lang_decl (TEMPLATE_DECL, DECL_NAME (decl), NULL_TREE);
3623 DECL_TEMPLATE_PARMS (tmpl) = parms;
3624 DECL_CONTEXT (tmpl) = DECL_CONTEXT (decl);
3625 DECL_MEMBER_TEMPLATE_P (tmpl) = member_template_p;
3630 struct template_parm_data
3632 /* The level of the template parameters we are currently
3636 /* The index of the specialization argument we are currently
3640 /* An array whose size is the number of template parameters. The
3641 elements are nonzero if the parameter has been used in any one
3642 of the arguments processed so far. */
3645 /* An array whose size is the number of template arguments. The
3646 elements are nonzero if the argument makes use of template
3647 parameters of this level. */
3648 int* arg_uses_template_parms;
3651 /* Subroutine of push_template_decl used to see if each template
3652 parameter in a partial specialization is used in the explicit
3653 argument list. If T is of the LEVEL given in DATA (which is
3654 treated as a template_parm_data*), then DATA->PARMS is marked
3658 mark_template_parm (tree t, void* data)
3662 struct template_parm_data* tpd = (struct template_parm_data*) data;
3664 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
3666 level = TEMPLATE_PARM_LEVEL (t);
3667 idx = TEMPLATE_PARM_IDX (t);
3671 level = TEMPLATE_TYPE_LEVEL (t);
3672 idx = TEMPLATE_TYPE_IDX (t);
3675 if (level == tpd->level)
3677 tpd->parms[idx] = 1;
3678 tpd->arg_uses_template_parms[tpd->current_arg] = 1;
3681 /* Return zero so that for_each_template_parm will continue the
3682 traversal of the tree; we want to mark *every* template parm. */
3686 /* Process the partial specialization DECL. */
3689 process_partial_specialization (tree decl)
3691 tree type = TREE_TYPE (decl);
3692 tree maintmpl = CLASSTYPE_TI_TEMPLATE (type);
3693 tree specargs = CLASSTYPE_TI_ARGS (type);
3694 tree inner_args = INNERMOST_TEMPLATE_ARGS (specargs);
3695 tree main_inner_parms = DECL_INNERMOST_TEMPLATE_PARMS (maintmpl);
3697 int nargs = TREE_VEC_LENGTH (inner_args);
3700 int did_error_intro = 0;
3701 struct template_parm_data tpd;
3702 struct template_parm_data tpd2;
3704 gcc_assert (current_template_parms);
3706 inner_parms = INNERMOST_TEMPLATE_PARMS (current_template_parms);
3707 ntparms = TREE_VEC_LENGTH (inner_parms);
3709 /* We check that each of the template parameters given in the
3710 partial specialization is used in the argument list to the
3711 specialization. For example:
3713 template <class T> struct S;
3714 template <class T> struct S<T*>;
3716 The second declaration is OK because `T*' uses the template
3717 parameter T, whereas
3719 template <class T> struct S<int>;
3721 is no good. Even trickier is:
3732 The S2<T> declaration is actually invalid; it is a
3733 full-specialization. Of course,
3736 struct S2<T (*)(U)>;
3738 or some such would have been OK. */
3739 tpd.level = TMPL_PARMS_DEPTH (current_template_parms);
3740 tpd.parms = (int *) alloca (sizeof (int) * ntparms);
3741 memset (tpd.parms, 0, sizeof (int) * ntparms);
3743 tpd.arg_uses_template_parms = (int *) alloca (sizeof (int) * nargs);
3744 memset (tpd.arg_uses_template_parms, 0, sizeof (int) * nargs);
3745 for (i = 0; i < nargs; ++i)
3747 tpd.current_arg = i;
3748 for_each_template_parm (TREE_VEC_ELT (inner_args, i),
3749 &mark_template_parm,
3752 /*include_nondeduced_p=*/false);
3754 for (i = 0; i < ntparms; ++i)
3755 if (tpd.parms[i] == 0)
3757 /* One of the template parms was not used in the
3759 if (!did_error_intro)
3761 error ("template parameters not used in partial specialization:");
3762 did_error_intro = 1;
3765 error (" %qD", TREE_VALUE (TREE_VEC_ELT (inner_parms, i)));
3768 /* [temp.class.spec]
3770 The argument list of the specialization shall not be identical to
3771 the implicit argument list of the primary template. */
3772 if (comp_template_args
3774 INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE
3776 error ("partial specialization %qT does not specialize any template arguments", type);
3778 /* [temp.class.spec]
3780 A partially specialized non-type argument expression shall not
3781 involve template parameters of the partial specialization except
3782 when the argument expression is a simple identifier.
3784 The type of a template parameter corresponding to a specialized
3785 non-type argument shall not be dependent on a parameter of the
3788 Also, we verify that pack expansions only occur at the
3789 end of the argument list. */
3790 gcc_assert (nargs == DECL_NTPARMS (maintmpl));
3792 for (i = 0; i < nargs; ++i)
3794 tree parm = TREE_VALUE (TREE_VEC_ELT (main_inner_parms, i));
3795 tree arg = TREE_VEC_ELT (inner_args, i);
3796 tree packed_args = NULL_TREE;
3799 if (ARGUMENT_PACK_P (arg))
3801 /* Extract the arguments from the argument pack. We'll be
3802 iterating over these in the following loop. */
3803 packed_args = ARGUMENT_PACK_ARGS (arg);
3804 len = TREE_VEC_LENGTH (packed_args);
3807 for (j = 0; j < len; j++)
3810 /* Get the Jth argument in the parameter pack. */
3811 arg = TREE_VEC_ELT (packed_args, j);
3813 if (PACK_EXPANSION_P (arg))
3815 /* Pack expansions must come at the end of the
3817 if ((packed_args && j < len - 1)
3818 || (!packed_args && i < nargs - 1))
3820 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
3821 error ("parameter pack argument %qE must be at the "
3822 "end of the template argument list", arg);
3824 error ("parameter pack argument %qT must be at the "
3825 "end of the template argument list", arg);
3829 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
3830 /* We only care about the pattern. */
3831 arg = PACK_EXPANSION_PATTERN (arg);
3833 if (/* These first two lines are the `non-type' bit. */
3835 && TREE_CODE (arg) != TEMPLATE_DECL
3836 /* This next line is the `argument expression is not just a
3837 simple identifier' condition and also the `specialized
3838 non-type argument' bit. */
3839 && TREE_CODE (arg) != TEMPLATE_PARM_INDEX)
3841 if ((!packed_args && tpd.arg_uses_template_parms[i])
3842 || (packed_args && uses_template_parms (arg)))
3843 error ("template argument %qE involves template parameter(s)",
3847 /* Look at the corresponding template parameter,
3848 marking which template parameters its type depends
3850 tree type = TREE_TYPE (parm);
3854 /* We haven't yet initialized TPD2. Do so now. */
3855 tpd2.arg_uses_template_parms
3856 = (int *) alloca (sizeof (int) * nargs);
3857 /* The number of parameters here is the number in the
3858 main template, which, as checked in the assertion
3860 tpd2.parms = (int *) alloca (sizeof (int) * nargs);
3862 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (maintmpl));
3865 /* Mark the template parameters. But this time, we're
3866 looking for the template parameters of the main
3867 template, not in the specialization. */
3868 tpd2.current_arg = i;
3869 tpd2.arg_uses_template_parms[i] = 0;
3870 memset (tpd2.parms, 0, sizeof (int) * nargs);
3871 for_each_template_parm (type,
3872 &mark_template_parm,
3875 /*include_nondeduced_p=*/false);
3877 if (tpd2.arg_uses_template_parms [i])
3879 /* The type depended on some template parameters.
3880 If they are fully specialized in the
3881 specialization, that's OK. */
3883 for (j = 0; j < nargs; ++j)
3884 if (tpd2.parms[j] != 0
3885 && tpd.arg_uses_template_parms [j])
3887 error ("type %qT of template argument %qE depends "
3888 "on template parameter(s)",
3899 /* We should only get here once. */
3900 gcc_assert (!COMPLETE_TYPE_P (type));
3902 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)
3903 = tree_cons (specargs, inner_parms,
3904 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl));
3905 TREE_TYPE (DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)) = type;
3909 /* Check that a template declaration's use of default arguments and
3910 parameter packs is not invalid. Here, PARMS are the template
3911 parameters. IS_PRIMARY is nonzero if DECL is the thing declared by
3912 a primary template. IS_PARTIAL is nonzero if DECL is a partial
3916 IS_FRIEND_DECL is nonzero if DECL is a friend function template
3917 declaration (but not a definition); 1 indicates a declaration, 2
3918 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
3919 emitted for extraneous default arguments.
3921 Returns TRUE if there were no errors found, FALSE otherwise. */
3924 check_default_tmpl_args (tree decl, tree parms, int is_primary,
3925 int is_partial, int is_friend_decl)
3928 int last_level_to_check;
3930 bool no_errors = true;
3934 A default template-argument shall not be specified in a
3935 function template declaration or a function template definition, nor
3936 in the template-parameter-list of the definition of a member of a
3939 if (TREE_CODE (CP_DECL_CONTEXT (decl)) == FUNCTION_DECL)
3940 /* You can't have a function template declaration in a local
3941 scope, nor you can you define a member of a class template in a
3945 if (current_class_type
3946 && !TYPE_BEING_DEFINED (current_class_type)
3947 && DECL_LANG_SPECIFIC (decl)
3948 && DECL_DECLARES_FUNCTION_P (decl)
3949 /* If this is either a friend defined in the scope of the class
3950 or a member function. */
3951 && (DECL_FUNCTION_MEMBER_P (decl)
3952 ? same_type_p (DECL_CONTEXT (decl), current_class_type)
3953 : DECL_FRIEND_CONTEXT (decl)
3954 ? same_type_p (DECL_FRIEND_CONTEXT (decl), current_class_type)
3956 /* And, if it was a member function, it really was defined in
3957 the scope of the class. */
3958 && (!DECL_FUNCTION_MEMBER_P (decl)
3959 || DECL_INITIALIZED_IN_CLASS_P (decl)))
3960 /* We already checked these parameters when the template was
3961 declared, so there's no need to do it again now. This function
3962 was defined in class scope, but we're processing it's body now
3963 that the class is complete. */
3966 /* Core issue 226 (C++0x only): the following only applies to class
3968 if ((cxx_dialect == cxx98) || TREE_CODE (decl) != FUNCTION_DECL)
3972 If a template-parameter has a default template-argument, all
3973 subsequent template-parameters shall have a default
3974 template-argument supplied. */
3975 for (parm_level = parms; parm_level; parm_level = TREE_CHAIN (parm_level))
3977 tree inner_parms = TREE_VALUE (parm_level);
3978 int ntparms = TREE_VEC_LENGTH (inner_parms);
3979 int seen_def_arg_p = 0;
3982 for (i = 0; i < ntparms; ++i)
3984 tree parm = TREE_VEC_ELT (inner_parms, i);
3986 if (parm == error_mark_node)
3989 if (TREE_PURPOSE (parm))
3991 else if (seen_def_arg_p
3992 && !template_parameter_pack_p (TREE_VALUE (parm)))
3994 error ("no default argument for %qD", TREE_VALUE (parm));
3995 /* For better subsequent error-recovery, we indicate that
3996 there should have been a default argument. */
3997 TREE_PURPOSE (parm) = error_mark_node;
4003 /* Don't complain about an enclosing partial
4005 && parm_level == parms
4006 && TREE_CODE (decl) == TYPE_DECL
4008 && template_parameter_pack_p (TREE_VALUE (parm)))
4010 /* A primary class template can only have one
4011 parameter pack, at the end of the template
4014 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL)
4015 error ("parameter pack %qE must be at the end of the"
4016 " template parameter list", TREE_VALUE (parm));
4018 error ("parameter pack %qT must be at the end of the"
4019 " template parameter list",
4020 TREE_TYPE (TREE_VALUE (parm)));
4022 TREE_VALUE (TREE_VEC_ELT (inner_parms, i))
4030 if (((cxx_dialect == cxx98) && TREE_CODE (decl) != TYPE_DECL)
4034 /* For an ordinary class template, default template arguments are
4035 allowed at the innermost level, e.g.:
4036 template <class T = int>
4038 but, in a partial specialization, they're not allowed even
4039 there, as we have in [temp.class.spec]:
4041 The template parameter list of a specialization shall not
4042 contain default template argument values.
4044 So, for a partial specialization, or for a function template
4045 (in C++98/C++03), we look at all of them. */
4048 /* But, for a primary class template that is not a partial
4049 specialization we look at all template parameters except the
4051 parms = TREE_CHAIN (parms);
4053 /* Figure out what error message to issue. */
4054 if (is_friend_decl == 2)
4055 msg = "default template arguments may not be used in function template friend re-declaration";
4056 else if (is_friend_decl)
4057 msg = "default template arguments may not be used in function template friend declarations";
4058 else if (TREE_CODE (decl) == FUNCTION_DECL && (cxx_dialect == cxx98))
4059 msg = ("default template arguments may not be used in function templates "
4060 "without -std=c++0x or -std=gnu++0x");
4061 else if (is_partial)
4062 msg = "default template arguments may not be used in partial specializations";
4064 msg = "default argument for template parameter for class enclosing %qD";
4066 if (current_class_type && TYPE_BEING_DEFINED (current_class_type))
4067 /* If we're inside a class definition, there's no need to
4068 examine the parameters to the class itself. On the one
4069 hand, they will be checked when the class is defined, and,
4070 on the other, default arguments are valid in things like:
4071 template <class T = double>
4072 struct S { template <class U> void f(U); };
4073 Here the default argument for `S' has no bearing on the
4074 declaration of `f'. */
4075 last_level_to_check = template_class_depth (current_class_type) + 1;
4077 /* Check everything. */
4078 last_level_to_check = 0;
4080 for (parm_level = parms;
4081 parm_level && TMPL_PARMS_DEPTH (parm_level) >= last_level_to_check;
4082 parm_level = TREE_CHAIN (parm_level))
4084 tree inner_parms = TREE_VALUE (parm_level);
4088 ntparms = TREE_VEC_LENGTH (inner_parms);
4089 for (i = 0; i < ntparms; ++i)
4091 if (TREE_VEC_ELT (inner_parms, i) == error_mark_node)
4094 if (TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)))
4099 if (is_friend_decl == 2)
4106 /* Clear out the default argument so that we are not
4108 TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)) = NULL_TREE;
4112 /* At this point, if we're still interested in issuing messages,
4113 they must apply to classes surrounding the object declared. */
4115 msg = "default argument for template parameter for class enclosing %qD";
4121 /* Worker for push_template_decl_real, called via
4122 for_each_template_parm. DATA is really an int, indicating the
4123 level of the parameters we are interested in. If T is a template
4124 parameter of that level, return nonzero. */
4127 template_parm_this_level_p (tree t, void* data)
4129 int this_level = *(int *)data;
4132 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
4133 level = TEMPLATE_PARM_LEVEL (t);
4135 level = TEMPLATE_TYPE_LEVEL (t);
4136 return level == this_level;
4139 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4140 parameters given by current_template_args, or reuses a
4141 previously existing one, if appropriate. Returns the DECL, or an
4142 equivalent one, if it is replaced via a call to duplicate_decls.
4144 If IS_FRIEND is true, DECL is a friend declaration. */
4147 push_template_decl_real (tree decl, bool is_friend)
4155 int new_template_p = 0;
4156 /* True if the template is a member template, in the sense of
4158 bool member_template_p = false;
4160 if (decl == error_mark_node || !current_template_parms)
4161 return error_mark_node;
4163 /* See if this is a partial specialization. */
4164 is_partial = (DECL_IMPLICIT_TYPEDEF_P (decl)
4165 && TREE_CODE (TREE_TYPE (decl)) != ENUMERAL_TYPE
4166 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)));
4168 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_FRIEND_P (decl))
4172 /* For a friend, we want the context of the friend function, not
4173 the type of which it is a friend. */
4174 ctx = DECL_CONTEXT (decl);
4175 else if (CP_DECL_CONTEXT (decl)
4176 && TREE_CODE (CP_DECL_CONTEXT (decl)) != NAMESPACE_DECL)
4177 /* In the case of a virtual function, we want the class in which
4179 ctx = CP_DECL_CONTEXT (decl);
4181 /* Otherwise, if we're currently defining some class, the DECL
4182 is assumed to be a member of the class. */
4183 ctx = current_scope ();
4185 if (ctx && TREE_CODE (ctx) == NAMESPACE_DECL)
4188 if (!DECL_CONTEXT (decl))
4189 DECL_CONTEXT (decl) = FROB_CONTEXT (current_namespace);
4191 /* See if this is a primary template. */
4192 if (is_friend && ctx)
4193 /* A friend template that specifies a class context, i.e.
4194 template <typename T> friend void A<T>::f();
4198 primary = template_parm_scope_p ();
4202 if (DECL_CLASS_SCOPE_P (decl))
4203 member_template_p = true;
4204 if (TREE_CODE (decl) == TYPE_DECL
4205 && ANON_AGGRNAME_P (DECL_NAME (decl)))
4207 error ("template class without a name");
4208 return error_mark_node;
4210 else if (TREE_CODE (decl) == FUNCTION_DECL)
4212 if (DECL_DESTRUCTOR_P (decl))
4216 A destructor shall not be a member template. */
4217 error ("destructor %qD declared as member template", decl);
4218 return error_mark_node;
4220 if (NEW_DELETE_OPNAME_P (DECL_NAME (decl))
4221 && (!TYPE_ARG_TYPES (TREE_TYPE (decl))
4222 || TYPE_ARG_TYPES (TREE_TYPE (decl)) == void_list_node
4223 || !TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (decl)))
4224 || (TREE_CHAIN (TYPE_ARG_TYPES ((TREE_TYPE (decl))))
4225 == void_list_node)))
4227 /* [basic.stc.dynamic.allocation]
4229 An allocation function can be a function
4230 template. ... Template allocation functions shall
4231 have two or more parameters. */
4232 error ("invalid template declaration of %qD", decl);
4233 return error_mark_node;
4236 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4237 && CLASS_TYPE_P (TREE_TYPE (decl)))
4241 error ("template declaration of %q#D", decl);
4242 return error_mark_node;
4246 /* Check to see that the rules regarding the use of default
4247 arguments are not being violated. */
4248 check_default_tmpl_args (decl, current_template_parms,
4249 primary, is_partial, /*is_friend_decl=*/0);
4251 /* Ensure that there are no parameter packs in the type of this
4252 declaration that have not been expanded. */
4253 if (TREE_CODE (decl) == FUNCTION_DECL)
4255 /* Check each of the arguments individually to see if there are
4256 any bare parameter packs. */
4257 tree type = TREE_TYPE (decl);
4258 tree arg = DECL_ARGUMENTS (decl);
4259 tree argtype = TYPE_ARG_TYPES (type);
4261 while (arg && argtype)
4263 if (!FUNCTION_PARAMETER_PACK_P (arg)
4264 && check_for_bare_parameter_packs (TREE_TYPE (arg)))
4266 /* This is a PARM_DECL that contains unexpanded parameter
4267 packs. We have already complained about this in the
4268 check_for_bare_parameter_packs call, so just replace
4269 these types with ERROR_MARK_NODE. */
4270 TREE_TYPE (arg) = error_mark_node;
4271 TREE_VALUE (argtype) = error_mark_node;
4274 arg = TREE_CHAIN (arg);
4275 argtype = TREE_CHAIN (argtype);
4278 /* Check for bare parameter packs in the return type and the
4279 exception specifiers. */
4280 if (check_for_bare_parameter_packs (TREE_TYPE (type)))
4281 /* Errors were already issued, set return type to int
4282 as the frontend doesn't expect error_mark_node as
4284 TREE_TYPE (type) = integer_type_node;
4285 if (check_for_bare_parameter_packs (TYPE_RAISES_EXCEPTIONS (type)))
4286 TYPE_RAISES_EXCEPTIONS (type) = NULL_TREE;
4288 else if (check_for_bare_parameter_packs (TREE_TYPE (decl)))
4290 TREE_TYPE (decl) = error_mark_node;
4291 return error_mark_node;
4295 return process_partial_specialization (decl);
4297 args = current_template_args ();
4300 || TREE_CODE (ctx) == FUNCTION_DECL
4301 || (CLASS_TYPE_P (ctx) && TYPE_BEING_DEFINED (ctx))
4302 || (is_friend && !DECL_TEMPLATE_INFO (decl)))
4304 if (DECL_LANG_SPECIFIC (decl)
4305 && DECL_TEMPLATE_INFO (decl)
4306 && DECL_TI_TEMPLATE (decl))
4307 tmpl = DECL_TI_TEMPLATE (decl);
4308 /* If DECL is a TYPE_DECL for a class-template, then there won't
4309 be DECL_LANG_SPECIFIC. The information equivalent to
4310 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4311 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4312 && TYPE_TEMPLATE_INFO (TREE_TYPE (decl))
4313 && TYPE_TI_TEMPLATE (TREE_TYPE (decl)))
4315 /* Since a template declaration already existed for this
4316 class-type, we must be redeclaring it here. Make sure
4317 that the redeclaration is valid. */
4318 redeclare_class_template (TREE_TYPE (decl),
4319 current_template_parms);
4320 /* We don't need to create a new TEMPLATE_DECL; just use the
4321 one we already had. */
4322 tmpl = TYPE_TI_TEMPLATE (TREE_TYPE (decl));
4326 tmpl = build_template_decl (decl, current_template_parms,
4330 if (DECL_LANG_SPECIFIC (decl)
4331 && DECL_TEMPLATE_SPECIALIZATION (decl))
4333 /* A specialization of a member template of a template
4335 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
4336 DECL_TEMPLATE_INFO (tmpl) = DECL_TEMPLATE_INFO (decl);
4337 DECL_TEMPLATE_INFO (decl) = NULL_TREE;
4343 tree a, t, current, parms;
4345 tree tinfo = get_template_info (decl);
4349 error ("template definition of non-template %q#D", decl);
4350 return error_mark_node;
4353 tmpl = TI_TEMPLATE (tinfo);
4355 if (DECL_FUNCTION_TEMPLATE_P (tmpl)
4356 && DECL_TEMPLATE_INFO (decl) && DECL_TI_ARGS (decl)
4357 && DECL_TEMPLATE_SPECIALIZATION (decl)
4358 && DECL_MEMBER_TEMPLATE_P (tmpl))
4362 /* The declaration is a specialization of a member
4363 template, declared outside the class. Therefore, the
4364 innermost template arguments will be NULL, so we
4365 replace them with the arguments determined by the
4366 earlier call to check_explicit_specialization. */
4367 args = DECL_TI_ARGS (decl);
4370 = build_template_decl (decl, current_template_parms,
4372 DECL_TEMPLATE_RESULT (new_tmpl) = decl;
4373 TREE_TYPE (new_tmpl) = TREE_TYPE (decl);
4374 DECL_TI_TEMPLATE (decl) = new_tmpl;
4375 SET_DECL_TEMPLATE_SPECIALIZATION (new_tmpl);
4376 DECL_TEMPLATE_INFO (new_tmpl)
4377 = build_template_info (tmpl, args);
4379 register_specialization (new_tmpl,
4380 most_general_template (tmpl),
4386 /* Make sure the template headers we got make sense. */
4388 parms = DECL_TEMPLATE_PARMS (tmpl);
4389 i = TMPL_PARMS_DEPTH (parms);
4390 if (TMPL_ARGS_DEPTH (args) != i)
4392 error ("expected %d levels of template parms for %q#D, got %d",
4393 i, decl, TMPL_ARGS_DEPTH (args));
4396 for (current = decl; i > 0; --i, parms = TREE_CHAIN (parms))
4398 a = TMPL_ARGS_LEVEL (args, i);
4399 t = INNERMOST_TEMPLATE_PARMS (parms);
4401 if (TREE_VEC_LENGTH (t) != TREE_VEC_LENGTH (a))
4403 if (current == decl)
4404 error ("got %d template parameters for %q#D",
4405 TREE_VEC_LENGTH (a), decl);
4407 error ("got %d template parameters for %q#T",
4408 TREE_VEC_LENGTH (a), current);
4409 error (" but %d required", TREE_VEC_LENGTH (t));
4410 return error_mark_node;
4413 if (current == decl)
4416 current = (TYPE_P (current)
4417 ? TYPE_CONTEXT (current)
4418 : DECL_CONTEXT (current));
4421 /* Check that the parms are used in the appropriate qualifying scopes
4422 in the declarator. */
4423 if (!comp_template_args
4425 TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (tmpl)))))
4428 template arguments to %qD do not match original template %qD",
4429 decl, DECL_TEMPLATE_RESULT (tmpl));
4430 if (!uses_template_parms (TI_ARGS (tinfo)))
4431 inform (input_location, "use template<> for an explicit specialization");
4432 /* Avoid crash in import_export_decl. */
4433 DECL_INTERFACE_KNOWN (decl) = 1;
4434 return error_mark_node;
4438 DECL_TEMPLATE_RESULT (tmpl) = decl;
4439 TREE_TYPE (tmpl) = TREE_TYPE (decl);
4441 /* Push template declarations for global functions and types. Note
4442 that we do not try to push a global template friend declared in a
4443 template class; such a thing may well depend on the template
4444 parameters of the class. */
4445 if (new_template_p && !ctx
4446 && !(is_friend && template_class_depth (current_class_type) > 0))
4448 tmpl = pushdecl_namespace_level (tmpl, is_friend);
4449 if (tmpl == error_mark_node)
4450 return error_mark_node;
4452 /* Hide template friend classes that haven't been declared yet. */
4453 if (is_friend && TREE_CODE (decl) == TYPE_DECL)
4455 DECL_ANTICIPATED (tmpl) = 1;
4456 DECL_FRIEND_P (tmpl) = 1;
4462 tree parms = DECL_TEMPLATE_PARMS (tmpl);
4465 DECL_PRIMARY_TEMPLATE (tmpl) = tmpl;
4466 if (DECL_CONV_FN_P (tmpl))
4468 int depth = TMPL_PARMS_DEPTH (parms);
4470 /* It is a conversion operator. See if the type converted to
4471 depends on innermost template operands. */
4473 if (uses_template_parms_level (TREE_TYPE (TREE_TYPE (tmpl)),
4475 DECL_TEMPLATE_CONV_FN_P (tmpl) = 1;
4478 /* Give template template parms a DECL_CONTEXT of the template
4479 for which they are a parameter. */
4480 parms = INNERMOST_TEMPLATE_PARMS (parms);
4481 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
4483 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
4484 if (TREE_CODE (parm) == TEMPLATE_DECL)
4485 DECL_CONTEXT (parm) = tmpl;
4489 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
4490 back to its most general template. If TMPL is a specialization,
4491 ARGS may only have the innermost set of arguments. Add the missing
4492 argument levels if necessary. */
4493 if (DECL_TEMPLATE_INFO (tmpl))
4494 args = add_outermost_template_args (DECL_TI_ARGS (tmpl), args);
4496 info = build_template_info (tmpl, args);
4498 if (DECL_IMPLICIT_TYPEDEF_P (decl))
4499 SET_TYPE_TEMPLATE_INFO (TREE_TYPE (tmpl), info);
4500 else if (DECL_LANG_SPECIFIC (decl))
4501 DECL_TEMPLATE_INFO (decl) = info;
4503 return DECL_TEMPLATE_RESULT (tmpl);
4507 push_template_decl (tree decl)
4509 return push_template_decl_real (decl, false);
4512 /* Called when a class template TYPE is redeclared with the indicated
4513 template PARMS, e.g.:
4515 template <class T> struct S;
4516 template <class T> struct S {}; */
4519 redeclare_class_template (tree type, tree parms)
4525 if (!TYPE_TEMPLATE_INFO (type))
4527 error ("%qT is not a template type", type);
4531 tmpl = TYPE_TI_TEMPLATE (type);
4532 if (!PRIMARY_TEMPLATE_P (tmpl))
4533 /* The type is nested in some template class. Nothing to worry
4534 about here; there are no new template parameters for the nested
4540 error ("template specifiers not specified in declaration of %qD",
4545 parms = INNERMOST_TEMPLATE_PARMS (parms);
4546 tmpl_parms = DECL_INNERMOST_TEMPLATE_PARMS (tmpl);
4548 if (TREE_VEC_LENGTH (parms) != TREE_VEC_LENGTH (tmpl_parms))
4550 error ("redeclared with %d template parameter(s)",
4551 TREE_VEC_LENGTH (parms));
4552 inform (input_location, "previous declaration %q+D used %d template parameter(s)",
4553 tmpl, TREE_VEC_LENGTH (tmpl_parms));
4557 for (i = 0; i < TREE_VEC_LENGTH (tmpl_parms); ++i)
4564 if (TREE_VEC_ELT (tmpl_parms, i) == error_mark_node
4565 || TREE_VEC_ELT (parms, i) == error_mark_node)
4568 tmpl_parm = TREE_VALUE (TREE_VEC_ELT (tmpl_parms, i));
4569 parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
4570 tmpl_default = TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i));
4571 parm_default = TREE_PURPOSE (TREE_VEC_ELT (parms, i));
4573 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
4575 if (tmpl_parm != error_mark_node
4576 && (TREE_CODE (tmpl_parm) != TREE_CODE (parm)
4577 || (TREE_CODE (tmpl_parm) != TYPE_DECL
4578 && !same_type_p (TREE_TYPE (tmpl_parm), TREE_TYPE (parm)))
4579 || (TREE_CODE (tmpl_parm) != PARM_DECL
4580 && (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (tmpl_parm))
4581 != TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm))))
4582 || (TREE_CODE (tmpl_parm) == PARM_DECL
4583 && (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (tmpl_parm))
4584 != TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))))))
4586 error ("template parameter %q+#D", tmpl_parm);
4587 error ("redeclared here as %q#D", parm);
4591 if (tmpl_default != NULL_TREE && parm_default != NULL_TREE)
4593 /* We have in [temp.param]:
4595 A template-parameter may not be given default arguments
4596 by two different declarations in the same scope. */
4597 error_at (input_location, "redefinition of default argument for %q#D", parm);
4598 inform (DECL_SOURCE_LOCATION (tmpl_parm),
4599 "original definition appeared here");
4603 if (parm_default != NULL_TREE)
4604 /* Update the previous template parameters (which are the ones
4605 that will really count) with the new default value. */
4606 TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i)) = parm_default;
4607 else if (tmpl_default != NULL_TREE)
4608 /* Update the new parameters, too; they'll be used as the
4609 parameters for any members. */
4610 TREE_PURPOSE (TREE_VEC_ELT (parms, i)) = tmpl_default;
4616 /* Simplify EXPR if it is a non-dependent expression. Returns the
4617 (possibly simplified) expression. */
4620 fold_non_dependent_expr (tree expr)
4622 if (expr == NULL_TREE)
4625 /* If we're in a template, but EXPR isn't value dependent, simplify
4626 it. We're supposed to treat:
4628 template <typename T> void f(T[1 + 1]);
4629 template <typename T> void f(T[2]);
4631 as two declarations of the same function, for example. */
4632 if (processing_template_decl
4633 && !type_dependent_expression_p (expr)
4634 && !value_dependent_expression_p (expr))
4636 HOST_WIDE_INT saved_processing_template_decl;
4638 saved_processing_template_decl = processing_template_decl;
4639 processing_template_decl = 0;
4640 expr = tsubst_copy_and_build (expr,
4643 /*in_decl=*/NULL_TREE,
4644 /*function_p=*/false,
4645 /*integral_constant_expression_p=*/true);
4646 processing_template_decl = saved_processing_template_decl;
4651 /* EXPR is an expression which is used in a constant-expression context.
4652 For instance, it could be a VAR_DECL with a constant initializer.
4653 Extract the innermost constant expression.
4655 This is basically a more powerful version of
4656 integral_constant_value, which can be used also in templates where
4657 initializers can maintain a syntactic rather than semantic form
4658 (even if they are non-dependent, for access-checking purposes). */
4661 fold_decl_constant_value (tree expr)
4663 tree const_expr = expr;
4666 expr = fold_non_dependent_expr (const_expr);
4667 const_expr = integral_constant_value (expr);
4669 while (expr != const_expr);
4674 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
4675 must be a function or a pointer-to-function type, as specified
4676 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
4677 and check that the resulting function has external linkage. */
4680 convert_nontype_argument_function (tree type, tree expr)
4685 fn = instantiate_type (type, fns, tf_none);
4686 if (fn == error_mark_node)
4687 return error_mark_node;
4690 if (TREE_CODE (fn_no_ptr) == ADDR_EXPR)
4691 fn_no_ptr = TREE_OPERAND (fn_no_ptr, 0);
4692 if (TREE_CODE (fn_no_ptr) == BASELINK)
4693 fn_no_ptr = BASELINK_FUNCTIONS (fn_no_ptr);
4695 /* [temp.arg.nontype]/1
4697 A template-argument for a non-type, non-template template-parameter
4700 -- the address of an object or function with external linkage. */
4701 if (!DECL_EXTERNAL_LINKAGE_P (fn_no_ptr))
4703 error ("%qE is not a valid template argument for type %qT "
4704 "because function %qD has not external linkage",
4705 expr, type, fn_no_ptr);
4712 /* Subroutine of convert_nontype_argument.
4713 Check if EXPR of type TYPE is a valid pointer-to-member constant.
4714 Emit an error otherwise. */
4717 check_valid_ptrmem_cst_expr (tree type, tree expr)
4720 if (expr && (null_ptr_cst_p (expr) || TREE_CODE (expr) == PTRMEM_CST))
4722 error ("%qE is not a valid template argument for type %qT",
4724 error ("it must be a pointer-to-member of the form `&X::Y'");
4728 /* Attempt to convert the non-type template parameter EXPR to the
4729 indicated TYPE. If the conversion is successful, return the
4730 converted value. If the conversion is unsuccessful, return
4731 NULL_TREE if we issued an error message, or error_mark_node if we
4732 did not. We issue error messages for out-and-out bad template
4733 parameters, but not simply because the conversion failed, since we
4734 might be just trying to do argument deduction. Both TYPE and EXPR
4735 must be non-dependent.
4737 The conversion follows the special rules described in
4738 [temp.arg.nontype], and it is much more strict than an implicit
4741 This function is called twice for each template argument (see
4742 lookup_template_class for a more accurate description of this
4743 problem). This means that we need to handle expressions which
4744 are not valid in a C++ source, but can be created from the
4745 first call (for instance, casts to perform conversions). These
4746 hacks can go away after we fix the double coercion problem. */
4749 convert_nontype_argument (tree type, tree expr)
4753 /* Detect immediately string literals as invalid non-type argument.
4754 This special-case is not needed for correctness (we would easily
4755 catch this later), but only to provide better diagnostic for this
4756 common user mistake. As suggested by DR 100, we do not mention
4757 linkage issues in the diagnostic as this is not the point. */
4758 if (TREE_CODE (expr) == STRING_CST)
4760 error ("%qE is not a valid template argument for type %qT "
4761 "because string literals can never be used in this context",
4766 /* If we are in a template, EXPR may be non-dependent, but still
4767 have a syntactic, rather than semantic, form. For example, EXPR
4768 might be a SCOPE_REF, rather than the VAR_DECL to which the
4769 SCOPE_REF refers. Preserving the qualifying scope is necessary
4770 so that access checking can be performed when the template is
4771 instantiated -- but here we need the resolved form so that we can
4772 convert the argument. */
4773 expr = fold_non_dependent_expr (expr);
4774 if (error_operand_p (expr))
4775 return error_mark_node;
4776 expr_type = TREE_TYPE (expr);
4778 /* HACK: Due to double coercion, we can get a
4779 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
4780 which is the tree that we built on the first call (see
4781 below when coercing to reference to object or to reference to
4782 function). We just strip everything and get to the arg.
4783 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
4785 if (TREE_CODE (expr) == NOP_EXPR)
4787 if (TYPE_REF_OBJ_P (type) || TYPE_REFFN_P (type))
4789 /* ??? Maybe we could use convert_from_reference here, but we
4790 would need to relax its constraints because the NOP_EXPR
4791 could actually change the type to something more cv-qualified,
4792 and this is not folded by convert_from_reference. */
4793 tree addr = TREE_OPERAND (expr, 0);
4794 gcc_assert (TREE_CODE (expr_type) == REFERENCE_TYPE);
4795 gcc_assert (TREE_CODE (addr) == ADDR_EXPR);
4796 gcc_assert (TREE_CODE (TREE_TYPE (addr)) == POINTER_TYPE);
4797 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4798 (TREE_TYPE (expr_type),
4799 TREE_TYPE (TREE_TYPE (addr))));
4801 expr = TREE_OPERAND (addr, 0);
4802 expr_type = TREE_TYPE (expr);
4805 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
4806 parameter is a pointer to object, through decay and
4807 qualification conversion. Let's strip everything. */
4808 else if (TYPE_PTROBV_P (type))
4811 gcc_assert (TREE_CODE (expr) == ADDR_EXPR);
4812 gcc_assert (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE);
4813 /* Skip the ADDR_EXPR only if it is part of the decay for
4814 an array. Otherwise, it is part of the original argument
4815 in the source code. */
4816 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == ARRAY_TYPE)
4817 expr = TREE_OPERAND (expr, 0);
4818 expr_type = TREE_TYPE (expr);
4822 /* [temp.arg.nontype]/5, bullet 1
4824 For a non-type template-parameter of integral or enumeration type,
4825 integral promotions (_conv.prom_) and integral conversions
4826 (_conv.integral_) are applied. */
4827 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
4829 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (expr_type))
4830 return error_mark_node;
4832 expr = fold_decl_constant_value (expr);
4833 /* Notice that there are constant expressions like '4 % 0' which
4834 do not fold into integer constants. */
4835 if (TREE_CODE (expr) != INTEGER_CST)
4837 error ("%qE is not a valid template argument for type %qT "
4838 "because it is a non-constant expression", expr, type);
4842 /* At this point, an implicit conversion does what we want,
4843 because we already know that the expression is of integral
4845 expr = ocp_convert (type, expr, CONV_IMPLICIT, LOOKUP_PROTECT);
4846 if (expr == error_mark_node)
4847 return error_mark_node;
4849 /* Conversion was allowed: fold it to a bare integer constant. */
4852 /* [temp.arg.nontype]/5, bullet 2
4854 For a non-type template-parameter of type pointer to object,
4855 qualification conversions (_conv.qual_) and the array-to-pointer
4856 conversion (_conv.array_) are applied. */
4857 else if (TYPE_PTROBV_P (type))
4859 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
4861 A template-argument for a non-type, non-template template-parameter
4862 shall be one of: [...]
4864 -- the name of a non-type template-parameter;
4865 -- the address of an object or function with external linkage, [...]
4866 expressed as "& id-expression" where the & is optional if the name
4867 refers to a function or array, or if the corresponding
4868 template-parameter is a reference.
4870 Here, we do not care about functions, as they are invalid anyway
4871 for a parameter of type pointer-to-object. */
4873 if (DECL_P (expr) && DECL_TEMPLATE_PARM_P (expr))
4874 /* Non-type template parameters are OK. */
4876 else if (TREE_CODE (expr) != ADDR_EXPR
4877 && TREE_CODE (expr_type) != ARRAY_TYPE)
4879 if (TREE_CODE (expr) == VAR_DECL)
4881 error ("%qD is not a valid template argument "
4882 "because %qD is a variable, not the address of "
4887 /* Other values, like integer constants, might be valid
4888 non-type arguments of some other type. */
4889 return error_mark_node;
4895 decl = ((TREE_CODE (expr) == ADDR_EXPR)
4896 ? TREE_OPERAND (expr, 0) : expr);
4897 if (TREE_CODE (decl) != VAR_DECL)
4899 error ("%qE is not a valid template argument of type %qT "
4900 "because %qE is not a variable",
4904 else if (!DECL_EXTERNAL_LINKAGE_P (decl))
4906 error ("%qE is not a valid template argument of type %qT "
4907 "because %qD does not have external linkage",
4913 expr = decay_conversion (expr);
4914 if (expr == error_mark_node)
4915 return error_mark_node;
4917 expr = perform_qualification_conversions (type, expr);
4918 if (expr == error_mark_node)
4919 return error_mark_node;
4921 /* [temp.arg.nontype]/5, bullet 3
4923 For a non-type template-parameter of type reference to object, no
4924 conversions apply. The type referred to by the reference may be more
4925 cv-qualified than the (otherwise identical) type of the
4926 template-argument. The template-parameter is bound directly to the
4927 template-argument, which must be an lvalue. */
4928 else if (TYPE_REF_OBJ_P (type))
4930 if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type),
4932 return error_mark_node;
4934 if (!at_least_as_qualified_p (TREE_TYPE (type), expr_type))
4936 error ("%qE is not a valid template argument for type %qT "
4937 "because of conflicts in cv-qualification", expr, type);
4941 if (!real_lvalue_p (expr))
4943 error ("%qE is not a valid template argument for type %qT "
4944 "because it is not an lvalue", expr, type);
4948 /* [temp.arg.nontype]/1
4950 A template-argument for a non-type, non-template template-parameter
4951 shall be one of: [...]
4953 -- the address of an object or function with external linkage. */
4954 if (TREE_CODE (expr) == INDIRECT_REF
4955 && TYPE_REF_OBJ_P (TREE_TYPE (TREE_OPERAND (expr, 0))))
4957 expr = TREE_OPERAND (expr, 0);
4960 error ("%q#D is not a valid template argument for type %qT "
4961 "because a reference variable does not have a constant "
4962 "address", expr, type);
4969 error ("%qE is not a valid template argument for type %qT "
4970 "because it is not an object with external linkage",
4975 if (!DECL_EXTERNAL_LINKAGE_P (expr))
4977 error ("%qE is not a valid template argument for type %qT "
4978 "because object %qD has not external linkage",
4983 expr = build_nop (type, build_address (expr));
4985 /* [temp.arg.nontype]/5, bullet 4
4987 For a non-type template-parameter of type pointer to function, only
4988 the function-to-pointer conversion (_conv.func_) is applied. If the
4989 template-argument represents a set of overloaded functions (or a
4990 pointer to such), the matching function is selected from the set
4992 else if (TYPE_PTRFN_P (type))
4994 /* If the argument is a template-id, we might not have enough
4995 context information to decay the pointer. */
4996 if (!type_unknown_p (expr_type))
4998 expr = decay_conversion (expr);
4999 if (expr == error_mark_node)
5000 return error_mark_node;
5003 expr = convert_nontype_argument_function (type, expr);
5004 if (!expr || expr == error_mark_node)
5007 if (TREE_CODE (expr) != ADDR_EXPR)
5009 error ("%qE is not a valid template argument for type %qT", expr, type);
5010 error ("it must be the address of a function with external linkage");
5014 /* [temp.arg.nontype]/5, bullet 5
5016 For a non-type template-parameter of type reference to function, no
5017 conversions apply. If the template-argument represents a set of
5018 overloaded functions, the matching function is selected from the set
5020 else if (TYPE_REFFN_P (type))
5022 if (TREE_CODE (expr) == ADDR_EXPR)
5024 error ("%qE is not a valid template argument for type %qT "
5025 "because it is a pointer", expr, type);
5026 inform (input_location, "try using %qE instead", TREE_OPERAND (expr, 0));
5030 expr = convert_nontype_argument_function (TREE_TYPE (type), expr);
5031 if (!expr || expr == error_mark_node)
5034 expr = build_nop (type, build_address (expr));
5036 /* [temp.arg.nontype]/5, bullet 6
5038 For a non-type template-parameter of type pointer to member function,
5039 no conversions apply. If the template-argument represents a set of
5040 overloaded member functions, the matching member function is selected
5041 from the set (_over.over_). */
5042 else if (TYPE_PTRMEMFUNC_P (type))
5044 expr = instantiate_type (type, expr, tf_none);
5045 if (expr == error_mark_node)
5046 return error_mark_node;
5048 /* [temp.arg.nontype] bullet 1 says the pointer to member
5049 expression must be a pointer-to-member constant. */
5050 if (!check_valid_ptrmem_cst_expr (type, expr))
5051 return error_mark_node;
5053 /* There is no way to disable standard conversions in
5054 resolve_address_of_overloaded_function (called by
5055 instantiate_type). It is possible that the call succeeded by
5056 converting &B::I to &D::I (where B is a base of D), so we need
5057 to reject this conversion here.
5059 Actually, even if there was a way to disable standard conversions,
5060 it would still be better to reject them here so that we can
5061 provide a superior diagnostic. */
5062 if (!same_type_p (TREE_TYPE (expr), type))
5064 /* Make sure we are just one standard conversion off. */
5065 gcc_assert (can_convert (type, TREE_TYPE (expr)));
5066 error ("%qE is not a valid template argument for type %qT "
5067 "because it is of type %qT", expr, type,
5069 inform (input_location, "standard conversions are not allowed in this context");
5073 /* [temp.arg.nontype]/5, bullet 7
5075 For a non-type template-parameter of type pointer to data member,
5076 qualification conversions (_conv.qual_) are applied. */
5077 else if (TYPE_PTRMEM_P (type))
5079 /* [temp.arg.nontype] bullet 1 says the pointer to member
5080 expression must be a pointer-to-member constant. */
5081 if (!check_valid_ptrmem_cst_expr (type, expr))
5082 return error_mark_node;
5084 expr = perform_qualification_conversions (type, expr);
5085 if (expr == error_mark_node)
5088 /* A template non-type parameter must be one of the above. */
5092 /* Sanity check: did we actually convert the argument to the
5094 gcc_assert (same_type_p (type, TREE_TYPE (expr)));
5098 /* Subroutine of coerce_template_template_parms, which returns 1 if
5099 PARM_PARM and ARG_PARM match using the rule for the template
5100 parameters of template template parameters. Both PARM and ARG are
5101 template parameters; the rest of the arguments are the same as for
5102 coerce_template_template_parms.
5105 coerce_template_template_parm (tree parm,
5107 tsubst_flags_t complain,
5111 if (arg == NULL_TREE || arg == error_mark_node
5112 || parm == NULL_TREE || parm == error_mark_node)
5115 if (TREE_CODE (arg) != TREE_CODE (parm))
5118 switch (TREE_CODE (parm))
5121 /* We encounter instantiations of templates like
5122 template <template <template <class> class> class TT>
5125 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
5126 tree argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
5128 if (!coerce_template_template_parms
5129 (parmparm, argparm, complain, in_decl, outer_args))
5135 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (arg))
5136 && !TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
5137 /* Argument is a parameter pack but parameter is not. */
5142 /* The tsubst call is used to handle cases such as
5144 template <int> class C {};
5145 template <class T, template <T> class TT> class D {};
5148 i.e. the parameter list of TT depends on earlier parameters. */
5149 if (!uses_template_parms (TREE_TYPE (arg))
5151 (tsubst (TREE_TYPE (parm), outer_args, complain, in_decl),
5155 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (arg))
5156 && !TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
5157 /* Argument is a parameter pack but parameter is not. */
5170 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
5171 template template parameters. Both PARM_PARMS and ARG_PARMS are
5172 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
5175 Consider the example:
5176 template <class T> class A;
5177 template<template <class U> class TT> class B;
5179 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
5180 the parameters to A, and OUTER_ARGS contains A. */
5183 coerce_template_template_parms (tree parm_parms,
5185 tsubst_flags_t complain,
5189 int nparms, nargs, i;
5193 gcc_assert (TREE_CODE (parm_parms) == TREE_VEC);
5194 gcc_assert (TREE_CODE (arg_parms) == TREE_VEC);
5196 nparms = TREE_VEC_LENGTH (parm_parms);
5197 nargs = TREE_VEC_LENGTH (arg_parms);
5199 /* Determine whether we have a parameter pack at the end of the
5200 template template parameter's template parameter list. */
5201 if (TREE_VEC_ELT (parm_parms, nparms - 1) != error_mark_node)
5203 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, nparms - 1));
5205 if (parm == error_mark_node)
5208 switch (TREE_CODE (parm))
5212 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
5217 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
5227 && !(variadic_p && nargs >= nparms - 1))
5230 /* Check all of the template parameters except the parameter pack at
5231 the end (if any). */
5232 for (i = 0; i < nparms - variadic_p; ++i)
5234 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node
5235 || TREE_VEC_ELT (arg_parms, i) == error_mark_node)
5238 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
5239 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
5241 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
5249 /* Check each of the template parameters in the template
5250 argument against the template parameter pack at the end of
5251 the template template parameter. */
5252 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node)
5255 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
5257 for (; i < nargs; ++i)
5259 if (TREE_VEC_ELT (arg_parms, i) == error_mark_node)
5262 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
5264 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
5273 /* Verifies that the deduced template arguments (in TARGS) for the
5274 template template parameters (in TPARMS) represent valid bindings,
5275 by comparing the template parameter list of each template argument
5276 to the template parameter list of its corresponding template
5277 template parameter, in accordance with DR150. This
5278 routine can only be called after all template arguments have been
5279 deduced. It will return TRUE if all of the template template
5280 parameter bindings are okay, FALSE otherwise. */
5282 template_template_parm_bindings_ok_p (tree tparms, tree targs)
5284 int i, ntparms = TREE_VEC_LENGTH (tparms);
5287 /* We're dealing with template parms in this process. */
5288 ++processing_template_decl;
5290 targs = INNERMOST_TEMPLATE_ARGS (targs);
5292 for (i = 0; i < ntparms; ++i)
5294 tree tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
5295 tree targ = TREE_VEC_ELT (targs, i);
5297 if (TREE_CODE (tparm) == TEMPLATE_DECL && targ)
5299 tree packed_args = NULL_TREE;
5302 if (ARGUMENT_PACK_P (targ))
5304 /* Look inside the argument pack. */
5305 packed_args = ARGUMENT_PACK_ARGS (targ);
5306 len = TREE_VEC_LENGTH (packed_args);
5309 for (idx = 0; idx < len; ++idx)
5311 tree targ_parms = NULL_TREE;
5314 /* Extract the next argument from the argument
5316 targ = TREE_VEC_ELT (packed_args, idx);
5318 if (PACK_EXPANSION_P (targ))
5319 /* Look at the pattern of the pack expansion. */
5320 targ = PACK_EXPANSION_PATTERN (targ);
5322 /* Extract the template parameters from the template
5324 if (TREE_CODE (targ) == TEMPLATE_DECL)
5325 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (targ);
5326 else if (TREE_CODE (targ) == TEMPLATE_TEMPLATE_PARM)
5327 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (TYPE_NAME (targ));
5329 /* Verify that we can coerce the template template
5330 parameters from the template argument to the template
5331 parameter. This requires an exact match. */
5333 && !coerce_template_template_parms
5334 (DECL_INNERMOST_TEMPLATE_PARMS (tparm),
5349 --processing_template_decl;
5353 /* Convert the indicated template ARG as necessary to match the
5354 indicated template PARM. Returns the converted ARG, or
5355 error_mark_node if the conversion was unsuccessful. Error and
5356 warning messages are issued under control of COMPLAIN. This
5357 conversion is for the Ith parameter in the parameter list. ARGS is
5358 the full set of template arguments deduced so far. */
5361 convert_template_argument (tree parm,
5364 tsubst_flags_t complain,
5370 int is_type, requires_type, is_tmpl_type, requires_tmpl_type;
5372 if (TREE_CODE (arg) == TREE_LIST
5373 && TREE_CODE (TREE_VALUE (arg)) == OFFSET_REF)
5375 /* The template argument was the name of some
5376 member function. That's usually
5377 invalid, but static members are OK. In any
5378 case, grab the underlying fields/functions
5379 and issue an error later if required. */
5380 orig_arg = TREE_VALUE (arg);
5381 TREE_TYPE (arg) = unknown_type_node;
5386 requires_tmpl_type = TREE_CODE (parm) == TEMPLATE_DECL;
5387 requires_type = (TREE_CODE (parm) == TYPE_DECL
5388 || requires_tmpl_type);
5390 /* When determining whether an argument pack expansion is a template,
5391 look at the pattern. */
5392 if (TREE_CODE (arg) == TYPE_PACK_EXPANSION)
5393 arg = PACK_EXPANSION_PATTERN (arg);
5395 /* Deal with an injected-class-name used as a template template arg. */
5396 if (requires_tmpl_type && CLASS_TYPE_P (arg))
5398 tree t = maybe_get_template_decl_from_type_decl (TYPE_NAME (arg));
5399 if (TREE_CODE (t) == TEMPLATE_DECL)
5401 if (complain & tf_warning_or_error)
5402 pedwarn (input_location, OPT_pedantic, "injected-class-name %qD"
5403 " used as template template argument", TYPE_NAME (arg));
5404 else if (flag_pedantic_errors)
5412 ((TREE_CODE (arg) == TEMPLATE_DECL
5413 && TREE_CODE (DECL_TEMPLATE_RESULT (arg)) == TYPE_DECL)
5414 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
5415 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE);
5418 && (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
5419 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE))
5420 arg = TYPE_STUB_DECL (arg);
5422 is_type = TYPE_P (arg) || is_tmpl_type;
5424 if (requires_type && ! is_type && TREE_CODE (arg) == SCOPE_REF
5425 && TREE_CODE (TREE_OPERAND (arg, 0)) == TEMPLATE_TYPE_PARM)
5427 permerror (input_location, "to refer to a type member of a template parameter, "
5428 "use %<typename %E%>", orig_arg);
5430 orig_arg = make_typename_type (TREE_OPERAND (arg, 0),
5431 TREE_OPERAND (arg, 1),
5433 complain & tf_error);
5437 if (is_type != requires_type)
5441 if (complain & tf_error)
5443 error ("type/value mismatch at argument %d in template "
5444 "parameter list for %qD",
5447 error (" expected a constant of type %qT, got %qT",
5449 (DECL_P (arg) ? DECL_NAME (arg) : orig_arg));
5450 else if (requires_tmpl_type)
5451 error (" expected a class template, got %qE", orig_arg);
5453 error (" expected a type, got %qE", orig_arg);
5456 return error_mark_node;
5458 if (is_tmpl_type ^ requires_tmpl_type)
5460 if (in_decl && (complain & tf_error))
5462 error ("type/value mismatch at argument %d in template "
5463 "parameter list for %qD",
5466 error (" expected a type, got %qT", DECL_NAME (arg));
5468 error (" expected a class template, got %qT", orig_arg);
5470 return error_mark_node;
5475 if (requires_tmpl_type)
5477 if (TREE_CODE (TREE_TYPE (arg)) == UNBOUND_CLASS_TEMPLATE)
5478 /* The number of argument required is not known yet.
5479 Just accept it for now. */
5480 val = TREE_TYPE (arg);
5483 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
5486 argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
5488 if (coerce_template_template_parms (parmparm, argparm,
5494 /* TEMPLATE_TEMPLATE_PARM node is preferred over
5496 if (val != error_mark_node)
5498 if (DECL_TEMPLATE_TEMPLATE_PARM_P (val))
5499 val = TREE_TYPE (val);
5500 if (TREE_CODE (orig_arg) == TYPE_PACK_EXPANSION)
5501 val = make_pack_expansion (val);
5506 if (in_decl && (complain & tf_error))
5508 error ("type/value mismatch at argument %d in "
5509 "template parameter list for %qD",
5511 error (" expected a template of type %qD, got %qT",
5515 val = error_mark_node;
5521 /* We only form one instance of each template specialization.
5522 Therefore, if we use a non-canonical variant (i.e., a
5523 typedef), any future messages referring to the type will use
5524 the typedef, which is confusing if those future uses do not
5525 themselves also use the typedef. */
5527 val = strip_typedefs (val);
5531 tree t = tsubst (TREE_TYPE (parm), args, complain, in_decl);
5533 if (invalid_nontype_parm_type_p (t, complain))
5534 return error_mark_node;
5536 if (template_parameter_pack_p (parm) && ARGUMENT_PACK_P (orig_arg))
5538 if (same_type_p (t, TREE_TYPE (orig_arg)))
5542 /* Not sure if this is reachable, but it doesn't hurt
5544 error ("type mismatch in nontype parameter pack");
5545 val = error_mark_node;
5548 else if (!uses_template_parms (orig_arg) && !uses_template_parms (t))
5549 /* We used to call digest_init here. However, digest_init
5550 will report errors, which we don't want when complain
5551 is zero. More importantly, digest_init will try too
5552 hard to convert things: for example, `0' should not be
5553 converted to pointer type at this point according to
5554 the standard. Accepting this is not merely an
5555 extension, since deciding whether or not these
5556 conversions can occur is part of determining which
5557 function template to call, or whether a given explicit
5558 argument specification is valid. */
5559 val = convert_nontype_argument (t, orig_arg);
5563 if (val == NULL_TREE)
5564 val = error_mark_node;
5565 else if (val == error_mark_node && (complain & tf_error))
5566 error ("could not convert template argument %qE to %qT", orig_arg, t);
5572 /* Coerces the remaining template arguments in INNER_ARGS (from
5573 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
5574 Returns the coerced argument pack. PARM_IDX is the position of this
5575 parameter in the template parameter list. ARGS is the original
5576 template argument list. */
5578 coerce_template_parameter_pack (tree parms,
5586 tsubst_flags_t complain)
5588 tree parm = TREE_VEC_ELT (parms, parm_idx);
5589 int nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
5592 tree packed_types = NULL_TREE;
5594 if (arg_idx > nargs)
5597 packed_args = make_tree_vec (nargs - arg_idx);
5599 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL
5600 && uses_parameter_packs (TREE_TYPE (TREE_VALUE (parm))))
5602 /* When the template parameter is a non-type template
5603 parameter pack whose type uses parameter packs, we need
5604 to look at each of the template arguments
5605 separately. Build a vector of the types for these
5606 non-type template parameters in PACKED_TYPES. */
5608 = make_pack_expansion (TREE_TYPE (TREE_VALUE (parm)));
5609 packed_types = tsubst_pack_expansion (expansion, args,
5612 if (packed_types == error_mark_node)
5613 return error_mark_node;
5615 /* Check that we have the right number of arguments. */
5617 && !PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx))
5618 && nargs - arg_idx != TREE_VEC_LENGTH (packed_types))
5621 = TREE_VEC_LENGTH (parms) - 1 + TREE_VEC_LENGTH (packed_types);
5622 error ("wrong number of template arguments (%d, should be %d)",
5623 nargs, needed_parms);
5624 return error_mark_node;
5627 /* If we aren't able to check the actual arguments now
5628 (because they haven't been expanded yet), we can at least
5629 verify that all of the types used for the non-type
5630 template parameter pack are, in fact, valid for non-type
5631 template parameters. */
5633 && PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx)))
5635 int j, len = TREE_VEC_LENGTH (packed_types);
5636 for (j = 0; j < len; ++j)
5638 tree t = TREE_VEC_ELT (packed_types, j);
5639 if (invalid_nontype_parm_type_p (t, complain))
5640 return error_mark_node;
5645 /* Convert the remaining arguments, which will be a part of the
5646 parameter pack "parm". */
5647 for (; arg_idx < nargs; ++arg_idx)
5649 tree arg = TREE_VEC_ELT (inner_args, arg_idx);
5650 tree actual_parm = TREE_VALUE (parm);
5652 if (packed_types && !PACK_EXPANSION_P (arg))
5654 /* When we have a vector of types (corresponding to the
5655 non-type template parameter pack that uses parameter
5656 packs in its type, as mention above), and the
5657 argument is not an expansion (which expands to a
5658 currently unknown number of arguments), clone the
5659 parm and give it the next type in PACKED_TYPES. */
5660 actual_parm = copy_node (actual_parm);
5661 TREE_TYPE (actual_parm) =
5662 TREE_VEC_ELT (packed_types, arg_idx - parm_idx);
5665 if (arg != error_mark_node)
5666 arg = convert_template_argument (actual_parm,
5667 arg, new_args, complain, parm_idx,
5669 if (arg == error_mark_node)
5671 TREE_VEC_ELT (packed_args, arg_idx - parm_idx) = arg;
5674 if (TREE_CODE (TREE_VALUE (parm)) == TYPE_DECL
5675 || TREE_CODE (TREE_VALUE (parm)) == TEMPLATE_DECL)
5676 argument_pack = cxx_make_type (TYPE_ARGUMENT_PACK);
5679 argument_pack = make_node (NONTYPE_ARGUMENT_PACK);
5680 TREE_TYPE (argument_pack)
5681 = tsubst (TREE_TYPE (TREE_VALUE (parm)), new_args, complain, in_decl);
5682 TREE_CONSTANT (argument_pack) = 1;
5685 SET_ARGUMENT_PACK_ARGS (argument_pack, packed_args);
5686 return argument_pack;
5689 /* Convert all template arguments to their appropriate types, and
5690 return a vector containing the innermost resulting template
5691 arguments. If any error occurs, return error_mark_node. Error and
5692 warning messages are issued under control of COMPLAIN.
5694 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
5695 for arguments not specified in ARGS. Otherwise, if
5696 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
5697 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
5698 USE_DEFAULT_ARGS is false, then all arguments must be specified in
5702 coerce_template_parms (tree parms,
5705 tsubst_flags_t complain,
5706 bool require_all_args,
5707 bool use_default_args)
5709 int nparms, nargs, parm_idx, arg_idx, lost = 0;
5712 tree new_inner_args;
5713 int saved_unevaluated_operand;
5714 int saved_inhibit_evaluation_warnings;
5716 /* When used as a boolean value, indicates whether this is a
5717 variadic template parameter list. Since it's an int, we can also
5718 subtract it from nparms to get the number of non-variadic
5722 nparms = TREE_VEC_LENGTH (parms);
5724 /* Determine if there are any parameter packs. */
5725 for (parm_idx = 0; parm_idx < nparms; ++parm_idx)
5727 tree tparm = TREE_VALUE (TREE_VEC_ELT (parms, parm_idx));
5728 if (template_parameter_pack_p (tparm))
5732 inner_args = INNERMOST_TEMPLATE_ARGS (args);
5733 /* If there are 0 or 1 parameter packs, we need to expand any argument
5734 packs so that we can deduce a parameter pack from some non-packed args
5735 followed by an argument pack, as in variadic85.C. If there are more
5736 than that, we need to leave argument packs intact so the arguments are
5737 assigned to the right parameter packs. This should only happen when
5738 dealing with a nested class inside a partial specialization of a class
5739 template, as in variadic92.C. */
5740 if (variadic_p <= 1)
5741 inner_args = expand_template_argument_pack (inner_args);
5743 nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
5744 if ((nargs > nparms && !variadic_p)
5745 || (nargs < nparms - variadic_p
5747 && (!use_default_args
5748 || (TREE_VEC_ELT (parms, nargs) != error_mark_node
5749 && !TREE_PURPOSE (TREE_VEC_ELT (parms, nargs))))))
5751 if (complain & tf_error)
5753 const char *or_more = "";
5756 or_more = " or more";
5760 error ("wrong number of template arguments (%d, should be %d%s)",
5761 nargs, nparms, or_more);
5764 error ("provided for %q+D", in_decl);
5767 return error_mark_node;
5770 /* We need to evaluate the template arguments, even though this
5771 template-id may be nested within a "sizeof". */
5772 saved_unevaluated_operand = cp_unevaluated_operand;
5773 cp_unevaluated_operand = 0;
5774 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
5775 c_inhibit_evaluation_warnings = 0;
5776 new_inner_args = make_tree_vec (nparms);
5777 new_args = add_outermost_template_args (args, new_inner_args);
5778 for (parm_idx = 0, arg_idx = 0; parm_idx < nparms; parm_idx++, arg_idx++)
5783 /* Get the Ith template parameter. */
5784 parm = TREE_VEC_ELT (parms, parm_idx);
5786 if (parm == error_mark_node)
5788 TREE_VEC_ELT (new_inner_args, arg_idx) = error_mark_node;
5792 /* Calculate the next argument. */
5793 if (arg_idx < nargs)
5794 arg = TREE_VEC_ELT (inner_args, arg_idx);
5798 if (template_parameter_pack_p (TREE_VALUE (parm))
5799 && !(arg && ARGUMENT_PACK_P (arg)))
5801 /* All remaining arguments will be placed in the
5802 template parameter pack PARM. */
5803 arg = coerce_template_parameter_pack (parms, parm_idx, args,
5804 inner_args, arg_idx,
5808 /* Store this argument. */
5809 if (arg == error_mark_node)
5811 TREE_VEC_ELT (new_inner_args, parm_idx) = arg;
5813 /* We are done with all of the arguments. */
5820 if (PACK_EXPANSION_P (arg))
5822 if (complain & tf_error)
5824 /* FIXME this restriction was removed by N2555; see
5826 /* If ARG is a pack expansion, but PARM is not a
5827 template parameter pack (if it were, we would have
5828 handled it above), we're trying to expand into a
5829 fixed-length argument list. */
5830 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
5831 sorry ("cannot expand %<%E%> into a fixed-length "
5832 "argument list", arg);
5834 sorry ("cannot expand %<%T%> into a fixed-length "
5835 "argument list", arg);
5837 return error_mark_node;
5840 else if (require_all_args)
5841 /* There must be a default arg in this case. */
5842 arg = tsubst_template_arg (TREE_PURPOSE (parm), new_args,
5847 if (arg == error_mark_node)
5849 if (complain & tf_error)
5850 error ("template argument %d is invalid", arg_idx + 1);
5853 /* This only occurs if there was an error in the template
5854 parameter list itself (which we would already have
5855 reported) that we are trying to recover from, e.g., a class
5856 template with a parameter list such as
5857 template<typename..., typename>. */
5858 return error_mark_node;
5860 arg = convert_template_argument (TREE_VALUE (parm),
5861 arg, new_args, complain,
5864 if (arg == error_mark_node)
5866 TREE_VEC_ELT (new_inner_args, arg_idx) = arg;
5868 cp_unevaluated_operand = saved_unevaluated_operand;
5869 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
5872 return error_mark_node;
5874 return new_inner_args;
5877 /* Returns 1 if template args OT and NT are equivalent. */
5880 template_args_equal (tree ot, tree nt)
5885 if (TREE_CODE (nt) == TREE_VEC)
5886 /* For member templates */
5887 return TREE_CODE (ot) == TREE_VEC && comp_template_args (ot, nt);
5888 else if (PACK_EXPANSION_P (ot))
5889 return PACK_EXPANSION_P (nt)
5890 && template_args_equal (PACK_EXPANSION_PATTERN (ot),
5891 PACK_EXPANSION_PATTERN (nt));
5892 else if (ARGUMENT_PACK_P (ot))
5897 if (!ARGUMENT_PACK_P (nt))
5900 opack = ARGUMENT_PACK_ARGS (ot);
5901 npack = ARGUMENT_PACK_ARGS (nt);
5902 len = TREE_VEC_LENGTH (opack);
5903 if (TREE_VEC_LENGTH (npack) != len)
5905 for (i = 0; i < len; ++i)
5906 if (!template_args_equal (TREE_VEC_ELT (opack, i),
5907 TREE_VEC_ELT (npack, i)))
5911 else if (ot && TREE_CODE (ot) == ARGUMENT_PACK_SELECT)
5913 /* We get here probably because we are in the middle of substituting
5914 into the pattern of a pack expansion. In that case the
5915 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
5916 interested in. So we want to use the initial pack argument for
5918 ot = ARGUMENT_PACK_SELECT_FROM_PACK (ot);
5919 if (nt && TREE_CODE (nt) == ARGUMENT_PACK_SELECT)
5920 nt = ARGUMENT_PACK_SELECT_FROM_PACK (nt);
5921 return template_args_equal (ot, nt);
5923 else if (TYPE_P (nt))
5924 return TYPE_P (ot) && same_type_p (ot, nt);
5925 else if (TREE_CODE (ot) == TREE_VEC || TYPE_P (ot))
5928 return cp_tree_equal (ot, nt);
5931 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
5932 of template arguments. Returns 0 otherwise. */
5935 comp_template_args (tree oldargs, tree newargs)
5939 if (TREE_VEC_LENGTH (oldargs) != TREE_VEC_LENGTH (newargs))
5942 for (i = 0; i < TREE_VEC_LENGTH (oldargs); ++i)
5944 tree nt = TREE_VEC_ELT (newargs, i);
5945 tree ot = TREE_VEC_ELT (oldargs, i);
5947 if (! template_args_equal (ot, nt))
5954 add_pending_template (tree d)
5956 tree ti = (TYPE_P (d)
5957 ? CLASSTYPE_TEMPLATE_INFO (d)
5958 : DECL_TEMPLATE_INFO (d));
5959 struct pending_template *pt;
5962 if (TI_PENDING_TEMPLATE_FLAG (ti))
5965 /* We are called both from instantiate_decl, where we've already had a
5966 tinst_level pushed, and instantiate_template, where we haven't.
5968 level = !current_tinst_level || current_tinst_level->decl != d;
5971 push_tinst_level (d);
5973 pt = GGC_NEW (struct pending_template);
5975 pt->tinst = current_tinst_level;
5976 if (last_pending_template)
5977 last_pending_template->next = pt;
5979 pending_templates = pt;
5981 last_pending_template = pt;
5983 TI_PENDING_TEMPLATE_FLAG (ti) = 1;
5990 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
5991 ARGLIST. Valid choices for FNS are given in the cp-tree.def
5992 documentation for TEMPLATE_ID_EXPR. */
5995 lookup_template_function (tree fns, tree arglist)
5999 if (fns == error_mark_node || arglist == error_mark_node)
6000 return error_mark_node;
6002 gcc_assert (!arglist || TREE_CODE (arglist) == TREE_VEC);
6003 gcc_assert (fns && (is_overloaded_fn (fns)
6004 || TREE_CODE (fns) == IDENTIFIER_NODE));
6006 if (BASELINK_P (fns))
6008 BASELINK_FUNCTIONS (fns) = build2 (TEMPLATE_ID_EXPR,
6010 BASELINK_FUNCTIONS (fns),
6015 type = TREE_TYPE (fns);
6016 if (TREE_CODE (fns) == OVERLOAD || !type)
6017 type = unknown_type_node;
6019 return build2 (TEMPLATE_ID_EXPR, type, fns, arglist);
6022 /* Within the scope of a template class S<T>, the name S gets bound
6023 (in build_self_reference) to a TYPE_DECL for the class, not a
6024 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
6025 or one of its enclosing classes, and that type is a template,
6026 return the associated TEMPLATE_DECL. Otherwise, the original
6029 Also handle the case when DECL is a TREE_LIST of ambiguous
6030 injected-class-names from different bases. */
6033 maybe_get_template_decl_from_type_decl (tree decl)
6035 if (decl == NULL_TREE)
6038 /* DR 176: A lookup that finds an injected-class-name (10.2
6039 [class.member.lookup]) can result in an ambiguity in certain cases
6040 (for example, if it is found in more than one base class). If all of
6041 the injected-class-names that are found refer to specializations of
6042 the same class template, and if the name is followed by a
6043 template-argument-list, the reference refers to the class template
6044 itself and not a specialization thereof, and is not ambiguous. */
6045 if (TREE_CODE (decl) == TREE_LIST)
6047 tree t, tmpl = NULL_TREE;
6048 for (t = decl; t; t = TREE_CHAIN (t))
6050 tree elt = maybe_get_template_decl_from_type_decl (TREE_VALUE (t));
6053 else if (tmpl != elt)
6056 if (tmpl && t == NULL_TREE)
6062 return (decl != NULL_TREE
6063 && DECL_SELF_REFERENCE_P (decl)
6064 && CLASSTYPE_TEMPLATE_INFO (TREE_TYPE (decl)))
6065 ? CLASSTYPE_TI_TEMPLATE (TREE_TYPE (decl)) : decl;
6068 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
6069 parameters, find the desired type.
6071 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
6073 IN_DECL, if non-NULL, is the template declaration we are trying to
6076 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
6077 the class we are looking up.
6079 Issue error and warning messages under control of COMPLAIN.
6081 If the template class is really a local class in a template
6082 function, then the FUNCTION_CONTEXT is the function in which it is
6085 ??? Note that this function is currently called *twice* for each
6086 template-id: the first time from the parser, while creating the
6087 incomplete type (finish_template_type), and the second type during the
6088 real instantiation (instantiate_template_class). This is surely something
6089 that we want to avoid. It also causes some problems with argument
6090 coercion (see convert_nontype_argument for more information on this). */
6093 lookup_template_class (tree d1,
6098 tsubst_flags_t complain)
6100 tree templ = NULL_TREE, parmlist;
6107 timevar_push (TV_NAME_LOOKUP);
6109 if (TREE_CODE (d1) == IDENTIFIER_NODE)
6111 tree value = innermost_non_namespace_value (d1);
6112 if (value && DECL_TEMPLATE_TEMPLATE_PARM_P (value))
6117 push_decl_namespace (context);
6118 templ = lookup_name (d1);
6119 templ = maybe_get_template_decl_from_type_decl (templ);
6121 pop_decl_namespace ();
6124 context = DECL_CONTEXT (templ);
6126 else if (TREE_CODE (d1) == TYPE_DECL && MAYBE_CLASS_TYPE_P (TREE_TYPE (d1)))
6128 tree type = TREE_TYPE (d1);
6130 /* If we are declaring a constructor, say A<T>::A<T>, we will get
6131 an implicit typename for the second A. Deal with it. */
6132 if (TREE_CODE (type) == TYPENAME_TYPE && TREE_TYPE (type))
6133 type = TREE_TYPE (type);
6135 if (CLASSTYPE_TEMPLATE_INFO (type))
6137 templ = CLASSTYPE_TI_TEMPLATE (type);
6138 d1 = DECL_NAME (templ);
6141 else if (TREE_CODE (d1) == ENUMERAL_TYPE
6142 || (TYPE_P (d1) && MAYBE_CLASS_TYPE_P (d1)))
6144 templ = TYPE_TI_TEMPLATE (d1);
6145 d1 = DECL_NAME (templ);
6147 else if (TREE_CODE (d1) == TEMPLATE_DECL
6148 && DECL_TEMPLATE_RESULT (d1)
6149 && TREE_CODE (DECL_TEMPLATE_RESULT (d1)) == TYPE_DECL)
6152 d1 = DECL_NAME (templ);
6153 context = DECL_CONTEXT (templ);
6156 /* Issue an error message if we didn't find a template. */
6159 if (complain & tf_error)
6160 error ("%qT is not a template", d1);
6161 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6164 if (TREE_CODE (templ) != TEMPLATE_DECL
6165 /* Make sure it's a user visible template, if it was named by
6167 || ((complain & tf_user) && !DECL_TEMPLATE_PARM_P (templ)
6168 && !PRIMARY_TEMPLATE_P (templ)))
6170 if (complain & tf_error)
6172 error ("non-template type %qT used as a template", d1);
6174 error ("for template declaration %q+D", in_decl);
6176 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6179 complain &= ~tf_user;
6181 if (DECL_TEMPLATE_TEMPLATE_PARM_P (templ))
6183 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
6184 template arguments */
6190 parmlist = DECL_INNERMOST_TEMPLATE_PARMS (templ);
6192 /* Consider an example where a template template parameter declared as
6194 template <class T, class U = std::allocator<T> > class TT
6196 The template parameter level of T and U are one level larger than
6197 of TT. To proper process the default argument of U, say when an
6198 instantiation `TT<int>' is seen, we need to build the full
6199 arguments containing {int} as the innermost level. Outer levels,
6200 available when not appearing as default template argument, can be
6201 obtained from the arguments of the enclosing template.
6203 Suppose that TT is later substituted with std::vector. The above
6204 instantiation is `TT<int, std::allocator<T> >' with TT at
6205 level 1, and T at level 2, while the template arguments at level 1
6206 becomes {std::vector} and the inner level 2 is {int}. */
6208 outer = DECL_CONTEXT (templ);
6210 outer = TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (outer)));
6211 else if (current_template_parms)
6212 /* This is an argument of the current template, so we haven't set
6213 DECL_CONTEXT yet. */
6214 outer = current_template_args ();
6217 arglist = add_to_template_args (outer, arglist);
6219 arglist2 = coerce_template_parms (parmlist, arglist, templ,
6221 /*require_all_args=*/true,
6222 /*use_default_args=*/true);
6223 if (arglist2 == error_mark_node
6224 || (!uses_template_parms (arglist2)
6225 && check_instantiated_args (templ, arglist2, complain)))
6226 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6228 parm = bind_template_template_parm (TREE_TYPE (templ), arglist2);
6229 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, parm);
6233 tree template_type = TREE_TYPE (templ);
6236 tree found = NULL_TREE;
6239 int is_partial_instantiation;
6241 gen_tmpl = most_general_template (templ);
6242 parmlist = DECL_TEMPLATE_PARMS (gen_tmpl);
6243 parm_depth = TMPL_PARMS_DEPTH (parmlist);
6244 arg_depth = TMPL_ARGS_DEPTH (arglist);
6246 if (arg_depth == 1 && parm_depth > 1)
6248 /* We've been given an incomplete set of template arguments.
6251 template <class T> struct S1 {
6252 template <class U> struct S2 {};
6253 template <class U> struct S2<U*> {};
6256 we will be called with an ARGLIST of `U*', but the
6257 TEMPLATE will be `template <class T> template
6258 <class U> struct S1<T>::S2'. We must fill in the missing
6261 = add_outermost_template_args (TYPE_TI_ARGS (TREE_TYPE (templ)),
6263 arg_depth = TMPL_ARGS_DEPTH (arglist);
6266 /* Now we should have enough arguments. */
6267 gcc_assert (parm_depth == arg_depth);
6269 /* From here on, we're only interested in the most general
6272 /* Calculate the BOUND_ARGS. These will be the args that are
6273 actually tsubst'd into the definition to create the
6277 /* We have multiple levels of arguments to coerce, at once. */
6279 int saved_depth = TMPL_ARGS_DEPTH (arglist);
6281 tree bound_args = make_tree_vec (parm_depth);
6283 for (i = saved_depth,
6284 t = DECL_TEMPLATE_PARMS (gen_tmpl);
6285 i > 0 && t != NULL_TREE;
6286 --i, t = TREE_CHAIN (t))
6288 tree a = coerce_template_parms (TREE_VALUE (t),
6291 /*require_all_args=*/true,
6292 /*use_default_args=*/true);
6294 /* Don't process further if one of the levels fails. */
6295 if (a == error_mark_node)
6297 /* Restore the ARGLIST to its full size. */
6298 TREE_VEC_LENGTH (arglist) = saved_depth;
6299 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6302 SET_TMPL_ARGS_LEVEL (bound_args, i, a);
6304 /* We temporarily reduce the length of the ARGLIST so
6305 that coerce_template_parms will see only the arguments
6306 corresponding to the template parameters it is
6308 TREE_VEC_LENGTH (arglist)--;
6311 /* Restore the ARGLIST to its full size. */
6312 TREE_VEC_LENGTH (arglist) = saved_depth;
6314 arglist = bound_args;
6318 = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parmlist),
6319 INNERMOST_TEMPLATE_ARGS (arglist),
6322 /*require_all_args=*/true,
6323 /*use_default_args=*/true);
6325 if (arglist == error_mark_node)
6326 /* We were unable to bind the arguments. */
6327 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6329 /* In the scope of a template class, explicit references to the
6330 template class refer to the type of the template, not any
6331 instantiation of it. For example, in:
6333 template <class T> class C { void f(C<T>); }
6335 the `C<T>' is just the same as `C'. Outside of the
6336 class, however, such a reference is an instantiation. */
6338 || !PRIMARY_TEMPLATE_P (gen_tmpl)
6339 || currently_open_class (template_type))
6340 /* comp_template_args is expensive, check it last. */
6341 && comp_template_args (TYPE_TI_ARGS (template_type),
6343 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, template_type);
6345 /* If we already have this specialization, return it. */
6346 elt.tmpl = gen_tmpl;
6348 hash = hash_specialization (&elt);
6349 entry = (spec_entry *) htab_find_with_hash (type_specializations,
6353 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, entry->spec);
6355 /* This type is a "partial instantiation" if any of the template
6356 arguments still involve template parameters. Note that we set
6357 IS_PARTIAL_INSTANTIATION for partial specializations as
6359 is_partial_instantiation = uses_template_parms (arglist);
6361 /* If the deduced arguments are invalid, then the binding
6363 if (!is_partial_instantiation
6364 && check_instantiated_args (gen_tmpl,
6365 INNERMOST_TEMPLATE_ARGS (arglist),
6367 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6369 if (!is_partial_instantiation
6370 && !PRIMARY_TEMPLATE_P (gen_tmpl)
6371 && !LAMBDA_TYPE_P (TREE_TYPE (gen_tmpl))
6372 && TREE_CODE (CP_DECL_CONTEXT (gen_tmpl)) == NAMESPACE_DECL)
6374 found = xref_tag_from_type (TREE_TYPE (gen_tmpl),
6375 DECL_NAME (gen_tmpl),
6376 /*tag_scope=*/ts_global);
6377 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, found);
6380 context = tsubst (DECL_CONTEXT (gen_tmpl), arglist,
6383 context = global_namespace;
6385 /* Create the type. */
6386 if (TREE_CODE (template_type) == ENUMERAL_TYPE)
6388 if (!is_partial_instantiation)
6390 set_current_access_from_decl (TYPE_NAME (template_type));
6391 t = start_enum (TYPE_IDENTIFIER (template_type),
6392 tsubst (ENUM_UNDERLYING_TYPE (template_type),
6393 arglist, complain, in_decl),
6394 SCOPED_ENUM_P (template_type));
6398 /* We don't want to call start_enum for this type, since
6399 the values for the enumeration constants may involve
6400 template parameters. And, no one should be interested
6401 in the enumeration constants for such a type. */
6402 t = cxx_make_type (ENUMERAL_TYPE);
6403 SET_SCOPED_ENUM_P (t, SCOPED_ENUM_P (template_type));
6408 t = make_class_type (TREE_CODE (template_type));
6409 CLASSTYPE_DECLARED_CLASS (t)
6410 = CLASSTYPE_DECLARED_CLASS (template_type);
6411 SET_CLASSTYPE_IMPLICIT_INSTANTIATION (t);
6412 TYPE_FOR_JAVA (t) = TYPE_FOR_JAVA (template_type);
6414 /* A local class. Make sure the decl gets registered properly. */
6415 if (context == current_function_decl)
6416 pushtag (DECL_NAME (gen_tmpl), t, /*tag_scope=*/ts_current);
6418 if (comp_template_args (CLASSTYPE_TI_ARGS (template_type), arglist))
6419 /* This instantiation is another name for the primary
6420 template type. Set the TYPE_CANONICAL field
6422 TYPE_CANONICAL (t) = template_type;
6423 else if (any_template_arguments_need_structural_equality_p (arglist))
6424 /* Some of the template arguments require structural
6425 equality testing, so this template class requires
6426 structural equality testing. */
6427 SET_TYPE_STRUCTURAL_EQUALITY (t);
6430 /* If we called start_enum or pushtag above, this information
6431 will already be set up. */
6434 TYPE_CONTEXT (t) = FROB_CONTEXT (context);
6436 type_decl = create_implicit_typedef (DECL_NAME (gen_tmpl), t);
6437 DECL_CONTEXT (type_decl) = TYPE_CONTEXT (t);
6438 DECL_SOURCE_LOCATION (type_decl)
6439 = DECL_SOURCE_LOCATION (TYPE_STUB_DECL (template_type));
6442 type_decl = TYPE_NAME (t);
6444 TREE_PRIVATE (type_decl)
6445 = TREE_PRIVATE (TYPE_STUB_DECL (template_type));
6446 TREE_PROTECTED (type_decl)
6447 = TREE_PROTECTED (TYPE_STUB_DECL (template_type));
6448 if (CLASSTYPE_VISIBILITY_SPECIFIED (template_type))
6450 DECL_VISIBILITY_SPECIFIED (type_decl) = 1;
6451 DECL_VISIBILITY (type_decl) = CLASSTYPE_VISIBILITY (template_type);
6454 /* Set up the template information. We have to figure out which
6455 template is the immediate parent if this is a full
6457 if (parm_depth == 1 || is_partial_instantiation
6458 || !PRIMARY_TEMPLATE_P (gen_tmpl))
6459 /* This case is easy; there are no member templates involved. */
6463 /* This is a full instantiation of a member template. Find
6464 the partial instantiation of which this is an instance. */
6466 /* Temporarily reduce by one the number of levels in the ARGLIST
6467 so as to avoid comparing the last set of arguments. */
6468 TREE_VEC_LENGTH (arglist)--;
6469 found = tsubst (gen_tmpl, arglist, complain, NULL_TREE);
6470 TREE_VEC_LENGTH (arglist)++;
6471 found = CLASSTYPE_TI_TEMPLATE (found);
6474 SET_TYPE_TEMPLATE_INFO (t, build_template_info (found, arglist));
6477 slot = (spec_entry **) htab_find_slot_with_hash (type_specializations,
6478 &elt, hash, INSERT);
6479 *slot = GGC_NEW (spec_entry);
6482 /* Note this use of the partial instantiation so we can check it
6483 later in maybe_process_partial_specialization. */
6484 DECL_TEMPLATE_INSTANTIATIONS (templ)
6485 = tree_cons (arglist, t,
6486 DECL_TEMPLATE_INSTANTIATIONS (templ));
6488 if (TREE_CODE (t) == ENUMERAL_TYPE
6489 && !is_partial_instantiation)
6490 /* Now that the type has been registered on the instantiations
6491 list, we set up the enumerators. Because the enumeration
6492 constants may involve the enumeration type itself, we make
6493 sure to register the type first, and then create the
6494 constants. That way, doing tsubst_expr for the enumeration
6495 constants won't result in recursive calls here; we'll find
6496 the instantiation and exit above. */
6497 tsubst_enum (template_type, t, arglist);
6499 if (is_partial_instantiation)
6500 /* If the type makes use of template parameters, the
6501 code that generates debugging information will crash. */
6502 DECL_IGNORED_P (TYPE_STUB_DECL (t)) = 1;
6504 /* Possibly limit visibility based on template args. */
6505 TREE_PUBLIC (type_decl) = 1;
6506 determine_visibility (type_decl);
6508 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, t);
6510 timevar_pop (TV_NAME_LOOKUP);
6517 /* True when we should also visit template parameters that occur in
6518 non-deduced contexts. */
6519 bool include_nondeduced_p;
6520 struct pointer_set_t *visited;
6523 /* Called from for_each_template_parm via walk_tree. */
6526 for_each_template_parm_r (tree *tp, int *walk_subtrees, void *d)
6529 struct pair_fn_data *pfd = (struct pair_fn_data *) d;
6530 tree_fn_t fn = pfd->fn;
6531 void *data = pfd->data;
6534 && (pfd->include_nondeduced_p || TREE_CODE (t) != TYPENAME_TYPE)
6535 && for_each_template_parm (TYPE_CONTEXT (t), fn, data, pfd->visited,
6536 pfd->include_nondeduced_p))
6537 return error_mark_node;
6539 switch (TREE_CODE (t))
6542 if (TYPE_PTRMEMFUNC_P (t))
6548 if (!TYPE_TEMPLATE_INFO (t))
6550 else if (for_each_template_parm (TI_ARGS (TYPE_TEMPLATE_INFO (t)),
6551 fn, data, pfd->visited,
6552 pfd->include_nondeduced_p))
6553 return error_mark_node;
6557 if (for_each_template_parm (TYPE_MIN_VALUE (t),
6558 fn, data, pfd->visited,
6559 pfd->include_nondeduced_p)
6560 || for_each_template_parm (TYPE_MAX_VALUE (t),
6561 fn, data, pfd->visited,
6562 pfd->include_nondeduced_p))
6563 return error_mark_node;
6567 /* Since we're not going to walk subtrees, we have to do this
6569 if (for_each_template_parm (TYPE_METHOD_BASETYPE (t), fn, data,
6570 pfd->visited, pfd->include_nondeduced_p))
6571 return error_mark_node;
6575 /* Check the return type. */
6576 if (for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
6577 pfd->include_nondeduced_p))
6578 return error_mark_node;
6580 /* Check the parameter types. Since default arguments are not
6581 instantiated until they are needed, the TYPE_ARG_TYPES may
6582 contain expressions that involve template parameters. But,
6583 no-one should be looking at them yet. And, once they're
6584 instantiated, they don't contain template parameters, so
6585 there's no point in looking at them then, either. */
6589 for (parm = TYPE_ARG_TYPES (t); parm; parm = TREE_CHAIN (parm))
6590 if (for_each_template_parm (TREE_VALUE (parm), fn, data,
6591 pfd->visited, pfd->include_nondeduced_p))
6592 return error_mark_node;
6594 /* Since we've already handled the TYPE_ARG_TYPES, we don't
6595 want walk_tree walking into them itself. */
6601 if (pfd->include_nondeduced_p
6602 && for_each_template_parm (TYPE_FIELDS (t), fn, data,
6604 pfd->include_nondeduced_p))
6605 return error_mark_node;
6610 if (DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t)
6611 && for_each_template_parm (DECL_TI_ARGS (t), fn, data,
6612 pfd->visited, pfd->include_nondeduced_p))
6613 return error_mark_node;
6618 if (TREE_CODE (t) == CONST_DECL && DECL_TEMPLATE_PARM_P (t)
6619 && for_each_template_parm (DECL_INITIAL (t), fn, data,
6620 pfd->visited, pfd->include_nondeduced_p))
6621 return error_mark_node;
6622 if (DECL_CONTEXT (t)
6623 && pfd->include_nondeduced_p
6624 && for_each_template_parm (DECL_CONTEXT (t), fn, data,
6625 pfd->visited, pfd->include_nondeduced_p))
6626 return error_mark_node;
6629 case BOUND_TEMPLATE_TEMPLATE_PARM:
6630 /* Record template parameters such as `T' inside `TT<T>'. */
6631 if (for_each_template_parm (TYPE_TI_ARGS (t), fn, data, pfd->visited,
6632 pfd->include_nondeduced_p))
6633 return error_mark_node;
6636 case TEMPLATE_TEMPLATE_PARM:
6637 case TEMPLATE_TYPE_PARM:
6638 case TEMPLATE_PARM_INDEX:
6639 if (fn && (*fn)(t, data))
6640 return error_mark_node;
6642 return error_mark_node;
6646 /* A template template parameter is encountered. */
6647 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t)
6648 && for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
6649 pfd->include_nondeduced_p))
6650 return error_mark_node;
6652 /* Already substituted template template parameter */
6658 || for_each_template_parm (TYPENAME_TYPE_FULLNAME (t), fn,
6660 pfd->include_nondeduced_p))
6661 return error_mark_node;
6665 if (TREE_TYPE (t) && TYPE_PTRMEMFUNC_P (TREE_TYPE (t))
6666 && pfd->include_nondeduced_p
6667 && for_each_template_parm (TYPE_PTRMEMFUNC_FN_TYPE
6668 (TREE_TYPE (t)), fn, data,
6669 pfd->visited, pfd->include_nondeduced_p))
6670 return error_mark_node;
6675 /* If there's no type, then this thing must be some expression
6676 involving template parameters. */
6677 if (!fn && !TREE_TYPE (t))
6678 return error_mark_node;
6683 case REINTERPRET_CAST_EXPR:
6684 case CONST_CAST_EXPR:
6685 case STATIC_CAST_EXPR:
6686 case DYNAMIC_CAST_EXPR:
6690 case PSEUDO_DTOR_EXPR:
6692 return error_mark_node;
6699 /* We didn't find any template parameters we liked. */
6703 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
6704 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
6705 call FN with the parameter and the DATA.
6706 If FN returns nonzero, the iteration is terminated, and
6707 for_each_template_parm returns 1. Otherwise, the iteration
6708 continues. If FN never returns a nonzero value, the value
6709 returned by for_each_template_parm is 0. If FN is NULL, it is
6710 considered to be the function which always returns 1.
6712 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
6713 parameters that occur in non-deduced contexts. When false, only
6714 visits those template parameters that can be deduced. */
6717 for_each_template_parm (tree t, tree_fn_t fn, void* data,
6718 struct pointer_set_t *visited,
6719 bool include_nondeduced_p)
6721 struct pair_fn_data pfd;
6727 pfd.include_nondeduced_p = include_nondeduced_p;
6729 /* Walk the tree. (Conceptually, we would like to walk without
6730 duplicates, but for_each_template_parm_r recursively calls
6731 for_each_template_parm, so we would need to reorganize a fair
6732 bit to use walk_tree_without_duplicates, so we keep our own
6735 pfd.visited = visited;
6737 pfd.visited = pointer_set_create ();
6738 result = cp_walk_tree (&t,
6739 for_each_template_parm_r,
6741 pfd.visited) != NULL_TREE;
6746 pointer_set_destroy (pfd.visited);
6753 /* Returns true if T depends on any template parameter. */
6756 uses_template_parms (tree t)
6759 int saved_processing_template_decl;
6761 saved_processing_template_decl = processing_template_decl;
6762 if (!saved_processing_template_decl)
6763 processing_template_decl = 1;
6765 dependent_p = dependent_type_p (t);
6766 else if (TREE_CODE (t) == TREE_VEC)
6767 dependent_p = any_dependent_template_arguments_p (t);
6768 else if (TREE_CODE (t) == TREE_LIST)
6769 dependent_p = (uses_template_parms (TREE_VALUE (t))
6770 || uses_template_parms (TREE_CHAIN (t)));
6771 else if (TREE_CODE (t) == TYPE_DECL)
6772 dependent_p = dependent_type_p (TREE_TYPE (t));
6775 || TREE_CODE (t) == TEMPLATE_PARM_INDEX
6776 || TREE_CODE (t) == OVERLOAD
6777 || TREE_CODE (t) == BASELINK
6778 || TREE_CODE (t) == IDENTIFIER_NODE
6779 || TREE_CODE (t) == TRAIT_EXPR
6780 || TREE_CODE (t) == CONSTRUCTOR
6781 || CONSTANT_CLASS_P (t))
6782 dependent_p = (type_dependent_expression_p (t)
6783 || value_dependent_expression_p (t));
6786 gcc_assert (t == error_mark_node);
6787 dependent_p = false;
6790 processing_template_decl = saved_processing_template_decl;
6795 /* Returns true if T depends on any template parameter with level LEVEL. */
6798 uses_template_parms_level (tree t, int level)
6800 return for_each_template_parm (t, template_parm_this_level_p, &level, NULL,
6801 /*include_nondeduced_p=*/true);
6804 static int tinst_depth;
6805 extern int max_tinst_depth;
6806 #ifdef GATHER_STATISTICS
6809 static int tinst_level_tick;
6810 static int last_template_error_tick;
6812 /* We're starting to instantiate D; record the template instantiation context
6813 for diagnostics and to restore it later. */
6816 push_tinst_level (tree d)
6818 struct tinst_level *new_level;
6820 if (tinst_depth >= max_tinst_depth)
6822 /* If the instantiation in question still has unbound template parms,
6823 we don't really care if we can't instantiate it, so just return.
6824 This happens with base instantiation for implicit `typename'. */
6825 if (uses_template_parms (d))
6828 last_template_error_tick = tinst_level_tick;
6829 error ("template instantiation depth exceeds maximum of %d (use "
6830 "-ftemplate-depth-NN to increase the maximum) instantiating %qD",
6831 max_tinst_depth, d);
6833 print_instantiation_context ();
6838 new_level = GGC_NEW (struct tinst_level);
6839 new_level->decl = d;
6840 new_level->locus = input_location;
6841 new_level->in_system_header_p = in_system_header;
6842 new_level->next = current_tinst_level;
6843 current_tinst_level = new_level;
6846 #ifdef GATHER_STATISTICS
6847 if (tinst_depth > depth_reached)
6848 depth_reached = tinst_depth;
6855 /* We're done instantiating this template; return to the instantiation
6859 pop_tinst_level (void)
6861 /* Restore the filename and line number stashed away when we started
6862 this instantiation. */
6863 input_location = current_tinst_level->locus;
6864 current_tinst_level = current_tinst_level->next;
6869 /* We're instantiating a deferred template; restore the template
6870 instantiation context in which the instantiation was requested, which
6871 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
6874 reopen_tinst_level (struct tinst_level *level)
6876 struct tinst_level *t;
6879 for (t = level; t; t = t->next)
6882 current_tinst_level = level;
6887 /* Returns the TINST_LEVEL which gives the original instantiation
6890 struct tinst_level *
6891 outermost_tinst_level (void)
6893 struct tinst_level *level = current_tinst_level;
6896 level = level->next;
6900 /* Returns TRUE if PARM is a parameter of the template TEMPL. */
6903 parameter_of_template_p (tree parm, tree templ)
6908 if (!parm || !templ)
6911 gcc_assert (DECL_TEMPLATE_PARM_P (parm));
6912 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
6914 parms = DECL_TEMPLATE_PARMS (templ);
6915 parms = INNERMOST_TEMPLATE_PARMS (parms);
6917 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
6918 if (parm == TREE_VALUE (TREE_VEC_ELT (parms, i)))
6924 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
6925 vector of template arguments, as for tsubst.
6927 Returns an appropriate tsubst'd friend declaration. */
6930 tsubst_friend_function (tree decl, tree args)
6934 if (TREE_CODE (decl) == FUNCTION_DECL
6935 && DECL_TEMPLATE_INSTANTIATION (decl)
6936 && TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
6937 /* This was a friend declared with an explicit template
6938 argument list, e.g.:
6942 to indicate that f was a template instantiation, not a new
6943 function declaration. Now, we have to figure out what
6944 instantiation of what template. */
6946 tree template_id, arglist, fns;
6949 tree ns = decl_namespace_context (TYPE_MAIN_DECL (current_class_type));
6951 /* Friend functions are looked up in the containing namespace scope.
6952 We must enter that scope, to avoid finding member functions of the
6953 current class with same name. */
6954 push_nested_namespace (ns);
6955 fns = tsubst_expr (DECL_TI_TEMPLATE (decl), args,
6956 tf_warning_or_error, NULL_TREE,
6957 /*integral_constant_expression_p=*/false);
6958 pop_nested_namespace (ns);
6959 arglist = tsubst (DECL_TI_ARGS (decl), args,
6960 tf_warning_or_error, NULL_TREE);
6961 template_id = lookup_template_function (fns, arglist);
6963 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
6964 tmpl = determine_specialization (template_id, new_friend,
6966 /*need_member_template=*/0,
6967 TREE_VEC_LENGTH (args),
6969 return instantiate_template (tmpl, new_args, tf_error);
6972 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
6974 /* The NEW_FRIEND will look like an instantiation, to the
6975 compiler, but is not an instantiation from the point of view of
6976 the language. For example, we might have had:
6978 template <class T> struct S {
6979 template <class U> friend void f(T, U);
6982 Then, in S<int>, template <class U> void f(int, U) is not an
6983 instantiation of anything. */
6984 if (new_friend == error_mark_node)
6985 return error_mark_node;
6987 DECL_USE_TEMPLATE (new_friend) = 0;
6988 if (TREE_CODE (decl) == TEMPLATE_DECL)
6990 DECL_USE_TEMPLATE (DECL_TEMPLATE_RESULT (new_friend)) = 0;
6991 DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (new_friend))
6992 = DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (decl));
6995 /* The mangled name for the NEW_FRIEND is incorrect. The function
6996 is not a template instantiation and should not be mangled like
6997 one. Therefore, we forget the mangling here; we'll recompute it
6998 later if we need it. */
6999 if (TREE_CODE (new_friend) != TEMPLATE_DECL)
7001 SET_DECL_RTL (new_friend, NULL_RTX);
7002 SET_DECL_ASSEMBLER_NAME (new_friend, NULL_TREE);
7005 if (DECL_NAMESPACE_SCOPE_P (new_friend))
7008 tree new_friend_template_info;
7009 tree new_friend_result_template_info;
7011 int new_friend_is_defn;
7013 /* We must save some information from NEW_FRIEND before calling
7014 duplicate decls since that function will free NEW_FRIEND if
7016 new_friend_template_info = DECL_TEMPLATE_INFO (new_friend);
7017 new_friend_is_defn =
7018 (DECL_INITIAL (DECL_TEMPLATE_RESULT
7019 (template_for_substitution (new_friend)))
7021 if (TREE_CODE (new_friend) == TEMPLATE_DECL)
7023 /* This declaration is a `primary' template. */
7024 DECL_PRIMARY_TEMPLATE (new_friend) = new_friend;
7026 new_friend_result_template_info
7027 = DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (new_friend));
7030 new_friend_result_template_info = NULL_TREE;
7032 /* Make the init_value nonzero so pushdecl knows this is a defn. */
7033 if (new_friend_is_defn)
7034 DECL_INITIAL (new_friend) = error_mark_node;
7036 /* Inside pushdecl_namespace_level, we will push into the
7037 current namespace. However, the friend function should go
7038 into the namespace of the template. */
7039 ns = decl_namespace_context (new_friend);
7040 push_nested_namespace (ns);
7041 old_decl = pushdecl_namespace_level (new_friend, /*is_friend=*/true);
7042 pop_nested_namespace (ns);
7044 if (old_decl == error_mark_node)
7045 return error_mark_node;
7047 if (old_decl != new_friend)
7049 /* This new friend declaration matched an existing
7050 declaration. For example, given:
7052 template <class T> void f(T);
7053 template <class U> class C {
7054 template <class T> friend void f(T) {}
7057 the friend declaration actually provides the definition
7058 of `f', once C has been instantiated for some type. So,
7059 old_decl will be the out-of-class template declaration,
7060 while new_friend is the in-class definition.
7062 But, if `f' was called before this point, the
7063 instantiation of `f' will have DECL_TI_ARGS corresponding
7064 to `T' but not to `U', references to which might appear
7065 in the definition of `f'. Previously, the most general
7066 template for an instantiation of `f' was the out-of-class
7067 version; now it is the in-class version. Therefore, we
7068 run through all specialization of `f', adding to their
7069 DECL_TI_ARGS appropriately. In particular, they need a
7070 new set of outer arguments, corresponding to the
7071 arguments for this class instantiation.
7073 The same situation can arise with something like this:
7076 template <class T> class C {
7080 when `C<int>' is instantiated. Now, `f(int)' is defined
7083 if (!new_friend_is_defn)
7084 /* On the other hand, if the in-class declaration does
7085 *not* provide a definition, then we don't want to alter
7086 existing definitions. We can just leave everything
7091 tree new_template = TI_TEMPLATE (new_friend_template_info);
7092 tree new_args = TI_ARGS (new_friend_template_info);
7094 /* Overwrite whatever template info was there before, if
7095 any, with the new template information pertaining to
7097 DECL_TEMPLATE_INFO (old_decl) = new_friend_template_info;
7099 if (TREE_CODE (old_decl) != TEMPLATE_DECL)
7100 /* We should have called reregister_specialization in
7102 gcc_assert (retrieve_specialization (new_template,
7109 /* Indicate that the old function template is a partial
7111 DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (old_decl))
7112 = new_friend_result_template_info;
7114 gcc_assert (new_template
7115 == most_general_template (new_template));
7116 gcc_assert (new_template != old_decl);
7118 /* Reassign any specializations already in the hash table
7119 to the new more general template, and add the
7120 additional template args. */
7121 for (t = DECL_TEMPLATE_INSTANTIATIONS (old_decl);
7125 tree spec = TREE_VALUE (t);
7128 elt.tmpl = old_decl;
7129 elt.args = DECL_TI_ARGS (spec);
7130 elt.spec = NULL_TREE;
7132 htab_remove_elt (decl_specializations, &elt);
7135 = add_outermost_template_args (new_args,
7136 DECL_TI_ARGS (spec));
7138 register_specialization
7139 (spec, new_template, DECL_TI_ARGS (spec), true, 0);
7142 DECL_TEMPLATE_INSTANTIATIONS (old_decl) = NULL_TREE;
7146 /* The information from NEW_FRIEND has been merged into OLD_DECL
7147 by duplicate_decls. */
7148 new_friend = old_decl;
7153 tree context = DECL_CONTEXT (new_friend);
7157 template <class T> class C {
7158 template <class U> friend void C1<U>::f (); // case 1
7159 friend void C2<T>::f (); // case 2
7161 we only need to make sure CONTEXT is a complete type for
7162 case 2. To distinguish between the two cases, we note that
7163 CONTEXT of case 1 remains dependent type after tsubst while
7164 this isn't true for case 2. */
7165 ++processing_template_decl;
7166 dependent_p = dependent_type_p (context);
7167 --processing_template_decl;
7170 && !complete_type_or_else (context, NULL_TREE))
7171 return error_mark_node;
7173 if (COMPLETE_TYPE_P (context))
7175 /* Check to see that the declaration is really present, and,
7176 possibly obtain an improved declaration. */
7177 tree fn = check_classfn (context,
7178 new_friend, NULL_TREE);
7188 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
7189 template arguments, as for tsubst.
7191 Returns an appropriate tsubst'd friend type or error_mark_node on
7195 tsubst_friend_class (tree friend_tmpl, tree args)
7201 context = DECL_CONTEXT (friend_tmpl);
7205 if (TREE_CODE (context) == NAMESPACE_DECL)
7206 push_nested_namespace (context);
7208 push_nested_class (tsubst (context, args, tf_none, NULL_TREE));
7211 /* Look for a class template declaration. We look for hidden names
7212 because two friend declarations of the same template are the
7213 same. For example, in:
7216 template <typename> friend class F;
7218 template <typename> struct B {
7219 template <typename> friend class F;
7222 both F templates are the same. */
7223 tmpl = lookup_name_real (DECL_NAME (friend_tmpl), 0, 0,
7224 /*block_p=*/true, 0,
7225 LOOKUP_COMPLAIN | LOOKUP_HIDDEN);
7227 /* But, if we don't find one, it might be because we're in a
7228 situation like this:
7236 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
7237 for `S<int>', not the TEMPLATE_DECL. */
7238 if (!tmpl || !DECL_CLASS_TEMPLATE_P (tmpl))
7240 tmpl = lookup_name_prefer_type (DECL_NAME (friend_tmpl), 1);
7241 tmpl = maybe_get_template_decl_from_type_decl (tmpl);
7244 if (tmpl && DECL_CLASS_TEMPLATE_P (tmpl))
7246 /* The friend template has already been declared. Just
7247 check to see that the declarations match, and install any new
7248 default parameters. We must tsubst the default parameters,
7249 of course. We only need the innermost template parameters
7250 because that is all that redeclare_class_template will look
7252 if (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (friend_tmpl))
7253 > TMPL_ARGS_DEPTH (args))
7256 location_t saved_input_location;
7257 parms = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_tmpl),
7258 args, tf_warning_or_error);
7260 saved_input_location = input_location;
7261 input_location = DECL_SOURCE_LOCATION (friend_tmpl);
7262 redeclare_class_template (TREE_TYPE (tmpl), parms);
7263 input_location = saved_input_location;
7267 friend_type = TREE_TYPE (tmpl);
7271 /* The friend template has not already been declared. In this
7272 case, the instantiation of the template class will cause the
7273 injection of this template into the global scope. */
7274 tmpl = tsubst (friend_tmpl, args, tf_warning_or_error, NULL_TREE);
7275 if (tmpl == error_mark_node)
7276 return error_mark_node;
7278 /* The new TMPL is not an instantiation of anything, so we
7279 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
7280 the new type because that is supposed to be the corresponding
7281 template decl, i.e., TMPL. */
7282 DECL_USE_TEMPLATE (tmpl) = 0;
7283 DECL_TEMPLATE_INFO (tmpl) = NULL_TREE;
7284 CLASSTYPE_USE_TEMPLATE (TREE_TYPE (tmpl)) = 0;
7285 CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl))
7286 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl)));
7288 /* Inject this template into the global scope. */
7289 friend_type = TREE_TYPE (pushdecl_top_level_maybe_friend (tmpl, true));
7294 if (TREE_CODE (context) == NAMESPACE_DECL)
7295 pop_nested_namespace (context);
7297 pop_nested_class ();
7303 /* Returns zero if TYPE cannot be completed later due to circularity.
7304 Otherwise returns one. */
7307 can_complete_type_without_circularity (tree type)
7309 if (type == NULL_TREE || type == error_mark_node)
7311 else if (COMPLETE_TYPE_P (type))
7313 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
7314 return can_complete_type_without_circularity (TREE_TYPE (type));
7315 else if (CLASS_TYPE_P (type)
7316 && TYPE_BEING_DEFINED (TYPE_MAIN_VARIANT (type)))
7322 /* Apply any attributes which had to be deferred until instantiation
7323 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
7324 ARGS, COMPLAIN, IN_DECL are as tsubst. */
7327 apply_late_template_attributes (tree *decl_p, tree attributes, int attr_flags,
7328 tree args, tsubst_flags_t complain, tree in_decl)
7330 tree last_dep = NULL_TREE;
7334 for (t = attributes; t; t = TREE_CHAIN (t))
7335 if (ATTR_IS_DEPENDENT (t))
7338 attributes = copy_list (attributes);
7342 if (DECL_P (*decl_p))
7344 if (TREE_TYPE (*decl_p) == error_mark_node)
7346 p = &DECL_ATTRIBUTES (*decl_p);
7349 p = &TYPE_ATTRIBUTES (*decl_p);
7353 tree late_attrs = NULL_TREE;
7354 tree *q = &late_attrs;
7356 for (*p = attributes; *p; )
7359 if (ATTR_IS_DEPENDENT (t))
7361 *p = TREE_CHAIN (t);
7362 TREE_CHAIN (t) = NULL_TREE;
7363 /* If the first attribute argument is an identifier, don't
7364 pass it through tsubst. Attributes like mode, format,
7365 cleanup and several target specific attributes expect it
7368 && TREE_CODE (TREE_VALUE (t)) == TREE_LIST
7369 && TREE_VALUE (TREE_VALUE (t))
7370 && (TREE_CODE (TREE_VALUE (TREE_VALUE (t)))
7371 == IDENTIFIER_NODE))
7374 = tsubst_expr (TREE_CHAIN (TREE_VALUE (t)), args, complain,
7376 /*integral_constant_expression_p=*/false);
7377 if (chain != TREE_CHAIN (TREE_VALUE (t)))
7379 = tree_cons (NULL_TREE, TREE_VALUE (TREE_VALUE (t)),
7384 = tsubst_expr (TREE_VALUE (t), args, complain, in_decl,
7385 /*integral_constant_expression_p=*/false);
7387 q = &TREE_CHAIN (t);
7390 p = &TREE_CHAIN (t);
7393 cplus_decl_attributes (decl_p, late_attrs, attr_flags);
7397 /* Perform (or defer) access check for typedefs that were referenced
7398 from within the template TMPL code.
7399 This is a subroutine of instantiate_template and instantiate_class_template.
7400 TMPL is the template to consider and TARGS is the list of arguments of
7404 perform_typedefs_access_check (tree tmpl, tree targs)
7406 location_t saved_location;
7408 qualified_typedef_usage_t *iter;
7411 || (!CLASS_TYPE_P (tmpl)
7412 && TREE_CODE (tmpl) != FUNCTION_DECL))
7415 saved_location = input_location;
7417 VEC_iterate (qualified_typedef_usage_t,
7418 get_types_needing_access_check (tmpl),
7422 tree type_decl = iter->typedef_decl;
7423 tree type_scope = iter->context;
7425 if (!type_decl || !type_scope || !CLASS_TYPE_P (type_scope))
7428 if (uses_template_parms (type_decl))
7429 type_decl = tsubst (type_decl, targs, tf_error, NULL_TREE);
7430 if (uses_template_parms (type_scope))
7431 type_scope = tsubst (type_scope, targs, tf_error, NULL_TREE);
7433 /* Make access check error messages point to the location
7434 of the use of the typedef. */
7435 input_location = iter->locus;
7436 perform_or_defer_access_check (TYPE_BINFO (type_scope),
7437 type_decl, type_decl);
7439 input_location = saved_location;
7443 instantiate_class_template (tree type)
7445 tree templ, args, pattern, t, member;
7449 unsigned int saved_maximum_field_alignment;
7451 if (type == error_mark_node)
7452 return error_mark_node;
7454 if (TYPE_BEING_DEFINED (type)
7455 || COMPLETE_TYPE_P (type)
7456 || uses_template_parms (type))
7459 /* Figure out which template is being instantiated. */
7460 templ = most_general_template (CLASSTYPE_TI_TEMPLATE (type));
7461 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
7463 /* Determine what specialization of the original template to
7465 t = most_specialized_class (type, templ);
7466 if (t == error_mark_node)
7468 TYPE_BEING_DEFINED (type) = 1;
7469 return error_mark_node;
7473 /* This TYPE is actually an instantiation of a partial
7474 specialization. We replace the innermost set of ARGS with
7475 the arguments appropriate for substitution. For example,
7478 template <class T> struct S {};
7479 template <class T> struct S<T*> {};
7481 and supposing that we are instantiating S<int*>, ARGS will
7482 presently be {int*} -- but we need {int}. */
7483 pattern = TREE_TYPE (t);
7484 args = TREE_PURPOSE (t);
7488 pattern = TREE_TYPE (templ);
7489 args = CLASSTYPE_TI_ARGS (type);
7492 /* If the template we're instantiating is incomplete, then clearly
7493 there's nothing we can do. */
7494 if (!COMPLETE_TYPE_P (pattern))
7497 /* If we've recursively instantiated too many templates, stop. */
7498 if (! push_tinst_level (type))
7501 /* Now we're really doing the instantiation. Mark the type as in
7502 the process of being defined. */
7503 TYPE_BEING_DEFINED (type) = 1;
7505 /* We may be in the middle of deferred access check. Disable
7507 push_deferring_access_checks (dk_no_deferred);
7509 push_to_top_level ();
7510 /* Use #pragma pack from the template context. */
7511 saved_maximum_field_alignment = maximum_field_alignment;
7512 maximum_field_alignment = TYPE_PRECISION (pattern);
7514 SET_CLASSTYPE_INTERFACE_UNKNOWN (type);
7516 /* Set the input location to the most specialized template definition.
7517 This is needed if tsubsting causes an error. */
7518 typedecl = TYPE_MAIN_DECL (pattern);
7519 input_location = DECL_SOURCE_LOCATION (typedecl);
7521 TYPE_HAS_USER_CONSTRUCTOR (type) = TYPE_HAS_USER_CONSTRUCTOR (pattern);
7522 TYPE_HAS_NEW_OPERATOR (type) = TYPE_HAS_NEW_OPERATOR (pattern);
7523 TYPE_HAS_ARRAY_NEW_OPERATOR (type) = TYPE_HAS_ARRAY_NEW_OPERATOR (pattern);
7524 TYPE_GETS_DELETE (type) = TYPE_GETS_DELETE (pattern);
7525 TYPE_HAS_ASSIGN_REF (type) = TYPE_HAS_ASSIGN_REF (pattern);
7526 TYPE_HAS_CONST_ASSIGN_REF (type) = TYPE_HAS_CONST_ASSIGN_REF (pattern);
7527 TYPE_HAS_INIT_REF (type) = TYPE_HAS_INIT_REF (pattern);
7528 TYPE_HAS_CONST_INIT_REF (type) = TYPE_HAS_CONST_INIT_REF (pattern);
7529 TYPE_HAS_DEFAULT_CONSTRUCTOR (type) = TYPE_HAS_DEFAULT_CONSTRUCTOR (pattern);
7530 TYPE_HAS_CONVERSION (type) = TYPE_HAS_CONVERSION (pattern);
7531 TYPE_PACKED (type) = TYPE_PACKED (pattern);
7532 TYPE_ALIGN (type) = TYPE_ALIGN (pattern);
7533 TYPE_USER_ALIGN (type) = TYPE_USER_ALIGN (pattern);
7534 TYPE_FOR_JAVA (type) = TYPE_FOR_JAVA (pattern); /* For libjava's JArray<T> */
7535 if (ANON_AGGR_TYPE_P (pattern))
7536 SET_ANON_AGGR_TYPE_P (type);
7537 if (CLASSTYPE_VISIBILITY_SPECIFIED (pattern))
7539 CLASSTYPE_VISIBILITY_SPECIFIED (type) = 1;
7540 CLASSTYPE_VISIBILITY (type) = CLASSTYPE_VISIBILITY (pattern);
7543 pbinfo = TYPE_BINFO (pattern);
7545 /* We should never instantiate a nested class before its enclosing
7546 class; we need to look up the nested class by name before we can
7547 instantiate it, and that lookup should instantiate the enclosing
7549 gcc_assert (!DECL_CLASS_SCOPE_P (TYPE_MAIN_DECL (pattern))
7550 || COMPLETE_TYPE_P (TYPE_CONTEXT (type))
7551 || TYPE_BEING_DEFINED (TYPE_CONTEXT (type)));
7553 base_list = NULL_TREE;
7554 if (BINFO_N_BASE_BINFOS (pbinfo))
7557 tree context = TYPE_CONTEXT (type);
7561 /* We must enter the scope containing the type, as that is where
7562 the accessibility of types named in dependent bases are
7564 pushed_scope = push_scope (context ? context : global_namespace);
7566 /* Substitute into each of the bases to determine the actual
7568 for (i = 0; BINFO_BASE_ITERATE (pbinfo, i, pbase_binfo); i++)
7571 tree access = BINFO_BASE_ACCESS (pbinfo, i);
7572 tree expanded_bases = NULL_TREE;
7575 if (PACK_EXPANSION_P (BINFO_TYPE (pbase_binfo)))
7578 tsubst_pack_expansion (BINFO_TYPE (pbase_binfo),
7579 args, tf_error, NULL_TREE);
7580 if (expanded_bases == error_mark_node)
7583 len = TREE_VEC_LENGTH (expanded_bases);
7586 for (idx = 0; idx < len; idx++)
7589 /* Extract the already-expanded base class. */
7590 base = TREE_VEC_ELT (expanded_bases, idx);
7592 /* Substitute to figure out the base class. */
7593 base = tsubst (BINFO_TYPE (pbase_binfo), args, tf_error,
7596 if (base == error_mark_node)
7599 base_list = tree_cons (access, base, base_list);
7600 if (BINFO_VIRTUAL_P (pbase_binfo))
7601 TREE_TYPE (base_list) = integer_type_node;
7605 /* The list is now in reverse order; correct that. */
7606 base_list = nreverse (base_list);
7609 pop_scope (pushed_scope);
7611 /* Now call xref_basetypes to set up all the base-class
7613 xref_basetypes (type, base_list);
7615 apply_late_template_attributes (&type, TYPE_ATTRIBUTES (pattern),
7616 (int) ATTR_FLAG_TYPE_IN_PLACE,
7617 args, tf_error, NULL_TREE);
7619 /* Now that our base classes are set up, enter the scope of the
7620 class, so that name lookups into base classes, etc. will work
7621 correctly. This is precisely analogous to what we do in
7622 begin_class_definition when defining an ordinary non-template
7623 class, except we also need to push the enclosing classes. */
7624 push_nested_class (type);
7626 /* Now members are processed in the order of declaration. */
7627 for (member = CLASSTYPE_DECL_LIST (pattern);
7628 member; member = TREE_CHAIN (member))
7630 tree t = TREE_VALUE (member);
7632 if (TREE_PURPOSE (member))
7636 /* Build new CLASSTYPE_NESTED_UTDS. */
7639 bool class_template_p;
7641 class_template_p = (TREE_CODE (t) != ENUMERAL_TYPE
7642 && TYPE_LANG_SPECIFIC (t)
7643 && CLASSTYPE_IS_TEMPLATE (t));
7644 /* If the member is a class template, then -- even after
7645 substitution -- there may be dependent types in the
7646 template argument list for the class. We increment
7647 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
7648 that function will assume that no types are dependent
7649 when outside of a template. */
7650 if (class_template_p)
7651 ++processing_template_decl;
7652 newtag = tsubst (t, args, tf_error, NULL_TREE);
7653 if (class_template_p)
7654 --processing_template_decl;
7655 if (newtag == error_mark_node)
7658 if (TREE_CODE (newtag) != ENUMERAL_TYPE)
7660 tree name = TYPE_IDENTIFIER (t);
7662 if (class_template_p)
7663 /* Unfortunately, lookup_template_class sets
7664 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
7665 instantiation (i.e., for the type of a member
7666 template class nested within a template class.)
7667 This behavior is required for
7668 maybe_process_partial_specialization to work
7669 correctly, but is not accurate in this case;
7670 the TAG is not an instantiation of anything.
7671 (The corresponding TEMPLATE_DECL is an
7672 instantiation, but the TYPE is not.) */
7673 CLASSTYPE_USE_TEMPLATE (newtag) = 0;
7675 /* Now, we call pushtag to put this NEWTAG into the scope of
7676 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
7677 pushtag calling push_template_decl. We don't have to do
7678 this for enums because it will already have been done in
7681 SET_IDENTIFIER_TYPE_VALUE (name, newtag);
7682 pushtag (name, newtag, /*tag_scope=*/ts_current);
7685 else if (TREE_CODE (t) == FUNCTION_DECL
7686 || DECL_FUNCTION_TEMPLATE_P (t))
7688 /* Build new TYPE_METHODS. */
7691 if (TREE_CODE (t) == TEMPLATE_DECL)
7692 ++processing_template_decl;
7693 r = tsubst (t, args, tf_error, NULL_TREE);
7694 if (TREE_CODE (t) == TEMPLATE_DECL)
7695 --processing_template_decl;
7696 set_current_access_from_decl (r);
7697 finish_member_declaration (r);
7701 /* Build new TYPE_FIELDS. */
7702 if (TREE_CODE (t) == STATIC_ASSERT)
7705 tsubst_expr (STATIC_ASSERT_CONDITION (t), args,
7706 tf_warning_or_error, NULL_TREE,
7707 /*integral_constant_expression_p=*/true);
7708 finish_static_assert (condition,
7709 STATIC_ASSERT_MESSAGE (t),
7710 STATIC_ASSERT_SOURCE_LOCATION (t),
7713 else if (TREE_CODE (t) != CONST_DECL)
7717 /* The file and line for this declaration, to
7718 assist in error message reporting. Since we
7719 called push_tinst_level above, we don't need to
7721 input_location = DECL_SOURCE_LOCATION (t);
7723 if (TREE_CODE (t) == TEMPLATE_DECL)
7724 ++processing_template_decl;
7725 r = tsubst (t, args, tf_warning_or_error, NULL_TREE);
7726 if (TREE_CODE (t) == TEMPLATE_DECL)
7727 --processing_template_decl;
7728 if (TREE_CODE (r) == VAR_DECL)
7732 [t]he initialization (and any associated
7733 side-effects) of a static data member does
7734 not occur unless the static data member is
7735 itself used in a way that requires the
7736 definition of the static data member to
7739 Therefore, we do not substitute into the
7740 initialized for the static data member here. */
7741 finish_static_data_member_decl
7744 /*init_const_expr_p=*/false,
7745 /*asmspec_tree=*/NULL_TREE,
7747 if (DECL_INITIALIZED_IN_CLASS_P (r))
7748 check_static_variable_definition (r, TREE_TYPE (r));
7750 else if (TREE_CODE (r) == FIELD_DECL)
7752 /* Determine whether R has a valid type and can be
7753 completed later. If R is invalid, then it is
7754 replaced by error_mark_node so that it will not be
7755 added to TYPE_FIELDS. */
7756 tree rtype = TREE_TYPE (r);
7757 if (can_complete_type_without_circularity (rtype))
7758 complete_type (rtype);
7760 if (!COMPLETE_TYPE_P (rtype))
7762 cxx_incomplete_type_error (r, rtype);
7763 r = error_mark_node;
7767 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
7768 such a thing will already have been added to the field
7769 list by tsubst_enum in finish_member_declaration in the
7770 CLASSTYPE_NESTED_UTDS case above. */
7771 if (!(TREE_CODE (r) == TYPE_DECL
7772 && TREE_CODE (TREE_TYPE (r)) == ENUMERAL_TYPE
7773 && DECL_ARTIFICIAL (r)))
7775 set_current_access_from_decl (r);
7776 finish_member_declaration (r);
7783 if (TYPE_P (t) || DECL_CLASS_TEMPLATE_P (t))
7785 /* Build new CLASSTYPE_FRIEND_CLASSES. */
7787 tree friend_type = t;
7788 bool adjust_processing_template_decl = false;
7790 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
7792 /* template <class T> friend class C; */
7793 friend_type = tsubst_friend_class (friend_type, args);
7794 adjust_processing_template_decl = true;
7796 else if (TREE_CODE (friend_type) == UNBOUND_CLASS_TEMPLATE)
7798 /* template <class T> friend class C::D; */
7799 friend_type = tsubst (friend_type, args,
7800 tf_warning_or_error, NULL_TREE);
7801 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
7802 friend_type = TREE_TYPE (friend_type);
7803 adjust_processing_template_decl = true;
7805 else if (TREE_CODE (friend_type) == TYPENAME_TYPE)
7807 /* This could be either
7811 when dependent_type_p is false or
7813 template <class U> friend class T::C;
7816 friend_type = tsubst (friend_type, args,
7817 tf_warning_or_error, NULL_TREE);
7818 /* Bump processing_template_decl for correct
7819 dependent_type_p calculation. */
7820 ++processing_template_decl;
7821 if (dependent_type_p (friend_type))
7822 adjust_processing_template_decl = true;
7823 --processing_template_decl;
7825 else if (!CLASSTYPE_USE_TEMPLATE (friend_type)
7826 && hidden_name_p (TYPE_NAME (friend_type)))
7830 where C hasn't been declared yet. Let's lookup name
7831 from namespace scope directly, bypassing any name that
7832 come from dependent base class. */
7833 tree ns = decl_namespace_context (TYPE_MAIN_DECL (friend_type));
7835 /* The call to xref_tag_from_type does injection for friend
7837 push_nested_namespace (ns);
7839 xref_tag_from_type (friend_type, NULL_TREE,
7840 /*tag_scope=*/ts_current);
7841 pop_nested_namespace (ns);
7843 else if (uses_template_parms (friend_type))
7844 /* friend class C<T>; */
7845 friend_type = tsubst (friend_type, args,
7846 tf_warning_or_error, NULL_TREE);
7851 where C is already declared or
7853 friend class C<int>;
7855 We don't have to do anything in these cases. */
7857 if (adjust_processing_template_decl)
7858 /* Trick make_friend_class into realizing that the friend
7859 we're adding is a template, not an ordinary class. It's
7860 important that we use make_friend_class since it will
7861 perform some error-checking and output cross-reference
7863 ++processing_template_decl;
7865 if (friend_type != error_mark_node)
7866 make_friend_class (type, friend_type, /*complain=*/false);
7868 if (adjust_processing_template_decl)
7869 --processing_template_decl;
7873 /* Build new DECL_FRIENDLIST. */
7876 /* The file and line for this declaration, to
7877 assist in error message reporting. Since we
7878 called push_tinst_level above, we don't need to
7880 input_location = DECL_SOURCE_LOCATION (t);
7882 if (TREE_CODE (t) == TEMPLATE_DECL)
7884 ++processing_template_decl;
7885 push_deferring_access_checks (dk_no_check);
7888 r = tsubst_friend_function (t, args);
7889 add_friend (type, r, /*complain=*/false);
7890 if (TREE_CODE (t) == TEMPLATE_DECL)
7892 pop_deferring_access_checks ();
7893 --processing_template_decl;
7899 /* Set the file and line number information to whatever is given for
7900 the class itself. This puts error messages involving generated
7901 implicit functions at a predictable point, and the same point
7902 that would be used for non-template classes. */
7903 input_location = DECL_SOURCE_LOCATION (typedecl);
7905 unreverse_member_declarations (type);
7906 finish_struct_1 (type);
7907 TYPE_BEING_DEFINED (type) = 0;
7909 /* Now that the class is complete, instantiate default arguments for
7910 any member functions. We don't do this earlier because the
7911 default arguments may reference members of the class. */
7912 if (!PRIMARY_TEMPLATE_P (templ))
7913 for (t = TYPE_METHODS (type); t; t = TREE_CHAIN (t))
7914 if (TREE_CODE (t) == FUNCTION_DECL
7915 /* Implicitly generated member functions will not have template
7916 information; they are not instantiations, but instead are
7917 created "fresh" for each instantiation. */
7918 && DECL_TEMPLATE_INFO (t))
7919 tsubst_default_arguments (t);
7921 /* Some typedefs referenced from within the template code need to be access
7922 checked at template instantiation time, i.e now. These types were
7923 added to the template at parsing time. Let's get those and perform
7924 the access checks then. */
7925 perform_typedefs_access_check (pattern, args);
7926 perform_deferred_access_checks ();
7927 pop_nested_class ();
7928 maximum_field_alignment = saved_maximum_field_alignment;
7929 pop_from_top_level ();
7930 pop_deferring_access_checks ();
7933 /* The vtable for a template class can be emitted in any translation
7934 unit in which the class is instantiated. When there is no key
7935 method, however, finish_struct_1 will already have added TYPE to
7936 the keyed_classes list. */
7937 if (TYPE_CONTAINS_VPTR_P (type) && CLASSTYPE_KEY_METHOD (type))
7938 keyed_classes = tree_cons (NULL_TREE, type, keyed_classes);
7944 tsubst_template_arg (tree t, tree args, tsubst_flags_t complain, tree in_decl)
7950 else if (TYPE_P (t))
7951 r = tsubst (t, args, complain, in_decl);
7954 r = tsubst_expr (t, args, complain, in_decl,
7955 /*integral_constant_expression_p=*/true);
7956 r = fold_non_dependent_expr (r);
7961 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
7962 NONTYPE_ARGUMENT_PACK. */
7965 make_fnparm_pack (tree spec_parm)
7967 /* Collect all of the extra "packed" parameters into an
7971 tree argpack = make_node (NONTYPE_ARGUMENT_PACK);
7972 tree argtypepack = cxx_make_type (TYPE_ARGUMENT_PACK);
7973 int i, len = list_length (spec_parm);
7975 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
7976 parmvec = make_tree_vec (len);
7977 parmtypevec = make_tree_vec (len);
7978 for (i = 0; i < len; i++, spec_parm = TREE_CHAIN (spec_parm))
7980 TREE_VEC_ELT (parmvec, i) = spec_parm;
7981 TREE_VEC_ELT (parmtypevec, i) = TREE_TYPE (spec_parm);
7984 /* Build the argument packs. */
7985 SET_ARGUMENT_PACK_ARGS (argpack, parmvec);
7986 SET_ARGUMENT_PACK_ARGS (argtypepack, parmtypevec);
7987 TREE_TYPE (argpack) = argtypepack;
7992 /* Substitute ARGS into T, which is an pack expansion
7993 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
7994 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
7995 (if only a partial substitution could be performed) or
7996 ERROR_MARK_NODE if there was an error. */
7998 tsubst_pack_expansion (tree t, tree args, tsubst_flags_t complain,
8002 tree pack, packs = NULL_TREE, unsubstituted_packs = NULL_TREE;
8003 tree first_arg_pack; int i, len = -1;
8006 bool very_local_specializations = false;
8008 gcc_assert (PACK_EXPANSION_P (t));
8009 pattern = PACK_EXPANSION_PATTERN (t);
8011 /* Determine the argument packs that will instantiate the parameter
8012 packs used in the expansion expression. While we're at it,
8013 compute the number of arguments to be expanded and make sure it
8015 for (pack = PACK_EXPANSION_PARAMETER_PACKS (t); pack;
8016 pack = TREE_CHAIN (pack))
8018 tree parm_pack = TREE_VALUE (pack);
8019 tree arg_pack = NULL_TREE;
8020 tree orig_arg = NULL_TREE;
8022 if (TREE_CODE (parm_pack) == PARM_DECL)
8024 arg_pack = retrieve_local_specialization (parm_pack);
8025 if (arg_pack == NULL_TREE)
8027 /* This can happen for a parameter name used later in a function
8028 declaration (such as in a late-specified return type). Just
8029 make a dummy decl, since it's only used for its type. */
8030 gcc_assert (cp_unevaluated_operand != 0);
8031 arg_pack = tsubst_decl (parm_pack, args, complain);
8032 arg_pack = make_fnparm_pack (arg_pack);
8037 int level, idx, levels;
8038 template_parm_level_and_index (parm_pack, &level, &idx);
8040 levels = TMPL_ARGS_DEPTH (args);
8041 if (level <= levels)
8042 arg_pack = TMPL_ARG (args, level, idx);
8045 orig_arg = arg_pack;
8046 if (arg_pack && TREE_CODE (arg_pack) == ARGUMENT_PACK_SELECT)
8047 arg_pack = ARGUMENT_PACK_SELECT_FROM_PACK (arg_pack);
8049 if (arg_pack && !ARGUMENT_PACK_P (arg_pack))
8050 /* This can only happen if we forget to expand an argument
8051 pack somewhere else. Just return an error, silently. */
8053 result = make_tree_vec (1);
8054 TREE_VEC_ELT (result, 0) = error_mark_node;
8059 && TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack)) == 1
8060 && PACK_EXPANSION_P (TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0)))
8062 tree expansion = TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0);
8063 tree pattern = PACK_EXPANSION_PATTERN (expansion);
8064 if ((TYPE_P (pattern) && same_type_p (pattern, parm_pack))
8065 || (!TYPE_P (pattern) && cp_tree_equal (parm_pack, pattern)))
8066 /* The argument pack that the parameter maps to is just an
8067 expansion of the parameter itself, such as one would
8068 find in the implicit typedef of a class inside the
8069 class itself. Consider this parameter "unsubstituted",
8070 so that we will maintain the outer pack expansion. */
8071 arg_pack = NULL_TREE;
8077 TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack));
8079 /* It's all-or-nothing with incomplete argument packs. */
8080 if (incomplete && !ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
8081 return error_mark_node;
8083 if (ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
8089 first_arg_pack = arg_pack;
8091 else if (len != my_len)
8094 /* We got explicit args for some packs but not others;
8095 do nothing now and try again after deduction. */
8097 if (TREE_CODE (t) == TYPE_PACK_EXPANSION)
8098 error ("mismatched argument pack lengths while expanding "
8102 error ("mismatched argument pack lengths while expanding "
8105 return error_mark_node;
8108 /* Keep track of the parameter packs and their corresponding
8110 packs = tree_cons (parm_pack, arg_pack, packs);
8111 TREE_TYPE (packs) = orig_arg;
8114 /* We can't substitute for this parameter pack. */
8115 unsubstituted_packs = tree_cons (TREE_PURPOSE (pack),
8117 unsubstituted_packs);
8120 /* We cannot expand this expansion expression, because we don't have
8121 all of the argument packs we need. Substitute into the pattern
8122 and return a PACK_EXPANSION_*. The caller will need to deal with
8124 if (unsubstituted_packs)
8127 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
8128 new_pat = tsubst_expr (pattern, args, complain, in_decl,
8129 /*integral_constant_expression_p=*/false);
8131 new_pat = tsubst (pattern, args, complain, in_decl);
8132 return make_pack_expansion (new_pat);
8135 /* We could not find any argument packs that work. */
8137 return error_mark_node;
8139 if (!local_specializations)
8141 /* We're in a late-specified return type, so we don't have a local
8142 specializations table. Create one for doing this expansion. */
8143 very_local_specializations = true;
8144 local_specializations = htab_create (37,
8145 hash_local_specialization,
8146 eq_local_specializations,
8150 /* For each argument in each argument pack, substitute into the
8152 result = make_tree_vec (len + incomplete);
8153 for (i = 0; i < len + incomplete; ++i)
8155 /* For parameter pack, change the substitution of the parameter
8156 pack to the ith argument in its argument pack, then expand
8158 for (pack = packs; pack; pack = TREE_CHAIN (pack))
8160 tree parm = TREE_PURPOSE (pack);
8162 if (TREE_CODE (parm) == PARM_DECL)
8164 /* Select the Ith argument from the pack. */
8165 tree arg = make_node (ARGUMENT_PACK_SELECT);
8166 ARGUMENT_PACK_SELECT_FROM_PACK (arg) = TREE_VALUE (pack);
8167 ARGUMENT_PACK_SELECT_INDEX (arg) = i;
8169 register_local_specialization (arg, parm);
8175 template_parm_level_and_index (parm, &level, &idx);
8179 /* Select the Ith argument from the pack. */
8180 value = make_node (ARGUMENT_PACK_SELECT);
8181 ARGUMENT_PACK_SELECT_FROM_PACK (value) = TREE_VALUE (pack);
8182 ARGUMENT_PACK_SELECT_INDEX (value) = i;
8185 /* Update the corresponding argument. */
8186 TMPL_ARG (args, level, idx) = value;
8190 /* Substitute into the PATTERN with the altered arguments. */
8191 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
8192 TREE_VEC_ELT (result, i) =
8193 tsubst_expr (pattern, args, complain, in_decl,
8194 /*integral_constant_expression_p=*/false);
8196 TREE_VEC_ELT (result, i) = tsubst (pattern, args, complain, in_decl);
8199 /* When we have incomplete argument packs, the last "expanded"
8200 result is itself a pack expansion, which allows us
8201 to deduce more arguments. */
8202 TREE_VEC_ELT (result, i) =
8203 make_pack_expansion (TREE_VEC_ELT (result, i));
8205 if (TREE_VEC_ELT (result, i) == error_mark_node)
8207 result = error_mark_node;
8212 /* Update ARGS to restore the substitution from parameter packs to
8213 their argument packs. */
8214 for (pack = packs; pack; pack = TREE_CHAIN (pack))
8216 tree parm = TREE_PURPOSE (pack);
8218 if (TREE_CODE (parm) == PARM_DECL)
8219 register_local_specialization (TREE_TYPE (pack), parm);
8223 template_parm_level_and_index (parm, &level, &idx);
8225 /* Update the corresponding argument. */
8226 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
8227 TREE_VEC_ELT (TREE_VEC_ELT (args, level -1 ), idx) =
8230 TREE_VEC_ELT (args, idx) = TREE_TYPE (pack);
8234 if (very_local_specializations)
8236 htab_delete (local_specializations);
8237 local_specializations = NULL;
8243 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
8244 TMPL. We do this using DECL_PARM_INDEX, which should work even with
8245 parameter packs; all parms generated from a function parameter pack will
8246 have the same DECL_PARM_INDEX. */
8249 get_pattern_parm (tree parm, tree tmpl)
8251 tree pattern = DECL_TEMPLATE_RESULT (tmpl);
8254 if (DECL_ARTIFICIAL (parm))
8256 for (patparm = DECL_ARGUMENTS (pattern);
8257 patparm; patparm = TREE_CHAIN (patparm))
8258 if (DECL_ARTIFICIAL (patparm)
8259 && DECL_NAME (parm) == DECL_NAME (patparm))
8264 patparm = FUNCTION_FIRST_USER_PARM (DECL_TEMPLATE_RESULT (tmpl));
8265 patparm = chain_index (DECL_PARM_INDEX (parm)-1, patparm);
8266 gcc_assert (DECL_PARM_INDEX (patparm)
8267 == DECL_PARM_INDEX (parm));
8273 /* Substitute ARGS into the vector or list of template arguments T. */
8276 tsubst_template_args (tree t, tree args, tsubst_flags_t complain, tree in_decl)
8279 int len = TREE_VEC_LENGTH (t);
8280 int need_new = 0, i, expanded_len_adjust = 0, out;
8281 tree *elts = (tree *) alloca (len * sizeof (tree));
8283 for (i = 0; i < len; i++)
8285 tree orig_arg = TREE_VEC_ELT (t, i);
8288 if (TREE_CODE (orig_arg) == TREE_VEC)
8289 new_arg = tsubst_template_args (orig_arg, args, complain, in_decl);
8290 else if (PACK_EXPANSION_P (orig_arg))
8292 /* Substitute into an expansion expression. */
8293 new_arg = tsubst_pack_expansion (orig_arg, args, complain, in_decl);
8295 if (TREE_CODE (new_arg) == TREE_VEC)
8296 /* Add to the expanded length adjustment the number of
8297 expanded arguments. We subtract one from this
8298 measurement, because the argument pack expression
8299 itself is already counted as 1 in
8300 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
8301 the argument pack is empty. */
8302 expanded_len_adjust += TREE_VEC_LENGTH (new_arg) - 1;
8304 else if (ARGUMENT_PACK_P (orig_arg))
8306 /* Substitute into each of the arguments. */
8307 new_arg = TYPE_P (orig_arg)
8308 ? cxx_make_type (TREE_CODE (orig_arg))
8309 : make_node (TREE_CODE (orig_arg));
8311 SET_ARGUMENT_PACK_ARGS (
8313 tsubst_template_args (ARGUMENT_PACK_ARGS (orig_arg),
8314 args, complain, in_decl));
8316 if (ARGUMENT_PACK_ARGS (new_arg) == error_mark_node)
8317 new_arg = error_mark_node;
8319 if (TREE_CODE (new_arg) == NONTYPE_ARGUMENT_PACK) {
8320 TREE_TYPE (new_arg) = tsubst (TREE_TYPE (orig_arg), args,
8322 TREE_CONSTANT (new_arg) = TREE_CONSTANT (orig_arg);
8324 if (TREE_TYPE (new_arg) == error_mark_node)
8325 new_arg = error_mark_node;
8329 new_arg = tsubst_template_arg (orig_arg, args, complain, in_decl);
8331 if (new_arg == error_mark_node)
8332 return error_mark_node;
8335 if (new_arg != orig_arg)
8342 /* Make space for the expanded arguments coming from template
8344 t = make_tree_vec (len + expanded_len_adjust);
8345 for (i = 0, out = 0; i < len; i++)
8347 if ((PACK_EXPANSION_P (TREE_VEC_ELT (orig_t, i))
8348 || ARGUMENT_PACK_P (TREE_VEC_ELT (orig_t, i)))
8349 && TREE_CODE (elts[i]) == TREE_VEC)
8353 /* Now expand the template argument pack "in place". */
8354 for (idx = 0; idx < TREE_VEC_LENGTH (elts[i]); idx++, out++)
8355 TREE_VEC_ELT (t, out) = TREE_VEC_ELT (elts[i], idx);
8359 TREE_VEC_ELT (t, out) = elts[i];
8367 /* Return the result of substituting ARGS into the template parameters
8368 given by PARMS. If there are m levels of ARGS and m + n levels of
8369 PARMS, then the result will contain n levels of PARMS. For
8370 example, if PARMS is `template <class T> template <class U>
8371 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
8372 result will be `template <int*, double, class V>'. */
8375 tsubst_template_parms (tree parms, tree args, tsubst_flags_t complain)
8380 /* When substituting into a template, we must set
8381 PROCESSING_TEMPLATE_DECL as the template parameters may be
8382 dependent if they are based on one-another, and the dependency
8383 predicates are short-circuit outside of templates. */
8384 ++processing_template_decl;
8386 for (new_parms = &r;
8387 TMPL_PARMS_DEPTH (parms) > TMPL_ARGS_DEPTH (args);
8388 new_parms = &(TREE_CHAIN (*new_parms)),
8389 parms = TREE_CHAIN (parms))
8392 make_tree_vec (TREE_VEC_LENGTH (TREE_VALUE (parms)));
8395 for (i = 0; i < TREE_VEC_LENGTH (new_vec); ++i)
8401 if (parms == error_mark_node)
8404 tuple = TREE_VEC_ELT (TREE_VALUE (parms), i);
8406 if (tuple == error_mark_node)
8409 default_value = TREE_PURPOSE (tuple);
8410 parm_decl = TREE_VALUE (tuple);
8412 parm_decl = tsubst (parm_decl, args, complain, NULL_TREE);
8413 if (TREE_CODE (parm_decl) == PARM_DECL
8414 && invalid_nontype_parm_type_p (TREE_TYPE (parm_decl), complain))
8415 parm_decl = error_mark_node;
8416 default_value = tsubst_template_arg (default_value, args,
8417 complain, NULL_TREE);
8419 tuple = build_tree_list (default_value, parm_decl);
8420 TREE_VEC_ELT (new_vec, i) = tuple;
8424 tree_cons (size_int (TMPL_PARMS_DEPTH (parms)
8425 - TMPL_ARGS_DEPTH (args)),
8426 new_vec, NULL_TREE);
8429 --processing_template_decl;
8434 /* Substitute the ARGS into the indicated aggregate (or enumeration)
8435 type T. If T is not an aggregate or enumeration type, it is
8436 handled as if by tsubst. IN_DECL is as for tsubst. If
8437 ENTERING_SCOPE is nonzero, T is the context for a template which
8438 we are presently tsubst'ing. Return the substituted value. */
8441 tsubst_aggr_type (tree t,
8443 tsubst_flags_t complain,
8450 switch (TREE_CODE (t))
8453 if (TYPE_PTRMEMFUNC_P (t))
8454 return tsubst (TYPE_PTRMEMFUNC_FN_TYPE (t), args, complain, in_decl);
8456 /* Else fall through. */
8459 if (TYPE_TEMPLATE_INFO (t) && uses_template_parms (t))
8464 int saved_unevaluated_operand;
8465 int saved_inhibit_evaluation_warnings;
8467 /* In "sizeof(X<I>)" we need to evaluate "I". */
8468 saved_unevaluated_operand = cp_unevaluated_operand;
8469 cp_unevaluated_operand = 0;
8470 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
8471 c_inhibit_evaluation_warnings = 0;
8473 /* First, determine the context for the type we are looking
8475 context = TYPE_CONTEXT (t);
8478 context = tsubst_aggr_type (context, args, complain,
8479 in_decl, /*entering_scope=*/1);
8480 /* If context is a nested class inside a class template,
8481 it may still need to be instantiated (c++/33959). */
8482 if (TYPE_P (context))
8483 context = complete_type (context);
8486 /* Then, figure out what arguments are appropriate for the
8487 type we are trying to find. For example, given:
8489 template <class T> struct S;
8490 template <class T, class U> void f(T, U) { S<U> su; }
8492 and supposing that we are instantiating f<int, double>,
8493 then our ARGS will be {int, double}, but, when looking up
8494 S we only want {double}. */
8495 argvec = tsubst_template_args (TYPE_TI_ARGS (t), args,
8497 if (argvec == error_mark_node)
8498 r = error_mark_node;
8501 r = lookup_template_class (t, argvec, in_decl, context,
8502 entering_scope, complain);
8503 r = cp_build_qualified_type_real (r, TYPE_QUALS (t), complain);
8506 cp_unevaluated_operand = saved_unevaluated_operand;
8507 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
8512 /* This is not a template type, so there's nothing to do. */
8516 return tsubst (t, args, complain, in_decl);
8520 /* Substitute into the default argument ARG (a default argument for
8521 FN), which has the indicated TYPE. */
8524 tsubst_default_argument (tree fn, tree type, tree arg)
8526 tree saved_class_ptr = NULL_TREE;
8527 tree saved_class_ref = NULL_TREE;
8529 /* This default argument came from a template. Instantiate the
8530 default argument here, not in tsubst. In the case of
8539 we must be careful to do name lookup in the scope of S<T>,
8540 rather than in the current class. */
8541 push_access_scope (fn);
8542 /* The "this" pointer is not valid in a default argument. */
8545 saved_class_ptr = current_class_ptr;
8546 cp_function_chain->x_current_class_ptr = NULL_TREE;
8547 saved_class_ref = current_class_ref;
8548 cp_function_chain->x_current_class_ref = NULL_TREE;
8551 push_deferring_access_checks(dk_no_deferred);
8552 /* The default argument expression may cause implicitly defined
8553 member functions to be synthesized, which will result in garbage
8554 collection. We must treat this situation as if we were within
8555 the body of function so as to avoid collecting live data on the
8558 arg = tsubst_expr (arg, DECL_TI_ARGS (fn),
8559 tf_warning_or_error, NULL_TREE,
8560 /*integral_constant_expression_p=*/false);
8562 pop_deferring_access_checks();
8564 /* Restore the "this" pointer. */
8567 cp_function_chain->x_current_class_ptr = saved_class_ptr;
8568 cp_function_chain->x_current_class_ref = saved_class_ref;
8571 /* Make sure the default argument is reasonable. */
8572 arg = check_default_argument (type, arg);
8574 pop_access_scope (fn);
8579 /* Substitute into all the default arguments for FN. */
8582 tsubst_default_arguments (tree fn)
8587 tmpl_args = DECL_TI_ARGS (fn);
8589 /* If this function is not yet instantiated, we certainly don't need
8590 its default arguments. */
8591 if (uses_template_parms (tmpl_args))
8594 for (arg = TYPE_ARG_TYPES (TREE_TYPE (fn));
8596 arg = TREE_CHAIN (arg))
8597 if (TREE_PURPOSE (arg))
8598 TREE_PURPOSE (arg) = tsubst_default_argument (fn,
8600 TREE_PURPOSE (arg));
8603 /* Substitute the ARGS into the T, which is a _DECL. Return the
8604 result of the substitution. Issue error and warning messages under
8605 control of COMPLAIN. */
8608 tsubst_decl (tree t, tree args, tsubst_flags_t complain)
8610 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
8611 location_t saved_loc;
8616 /* Set the filename and linenumber to improve error-reporting. */
8617 saved_loc = input_location;
8618 input_location = DECL_SOURCE_LOCATION (t);
8620 switch (TREE_CODE (t))
8624 /* We can get here when processing a member function template,
8625 member class template, or template template parameter. */
8626 tree decl = DECL_TEMPLATE_RESULT (t);
8631 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
8633 /* Template template parameter is treated here. */
8634 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8635 if (new_type == error_mark_node)
8636 RETURN (error_mark_node);
8639 TREE_CHAIN (r) = NULL_TREE;
8640 TREE_TYPE (r) = new_type;
8641 DECL_TEMPLATE_RESULT (r)
8642 = build_decl (DECL_SOURCE_LOCATION (decl),
8643 TYPE_DECL, DECL_NAME (decl), new_type);
8644 DECL_TEMPLATE_PARMS (r)
8645 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
8647 TYPE_NAME (new_type) = r;
8651 /* We might already have an instance of this template.
8652 The ARGS are for the surrounding class type, so the
8653 full args contain the tsubst'd args for the context,
8654 plus the innermost args from the template decl. */
8655 tmpl_args = DECL_CLASS_TEMPLATE_P (t)
8656 ? CLASSTYPE_TI_ARGS (TREE_TYPE (t))
8657 : DECL_TI_ARGS (DECL_TEMPLATE_RESULT (t));
8658 /* Because this is a template, the arguments will still be
8659 dependent, even after substitution. If
8660 PROCESSING_TEMPLATE_DECL is not set, the dependency
8661 predicates will short-circuit. */
8662 ++processing_template_decl;
8663 full_args = tsubst_template_args (tmpl_args, args,
8665 --processing_template_decl;
8666 if (full_args == error_mark_node)
8667 RETURN (error_mark_node);
8669 /* If this is a default template template argument,
8670 tsubst might not have changed anything. */
8671 if (full_args == tmpl_args)
8674 hash = hash_tmpl_and_args (t, full_args);
8675 spec = retrieve_specialization (t, full_args, hash);
8676 if (spec != NULL_TREE)
8682 /* Make a new template decl. It will be similar to the
8683 original, but will record the current template arguments.
8684 We also create a new function declaration, which is just
8685 like the old one, but points to this new template, rather
8686 than the old one. */
8688 gcc_assert (DECL_LANG_SPECIFIC (r) != 0);
8689 TREE_CHAIN (r) = NULL_TREE;
8691 DECL_TEMPLATE_INFO (r) = build_template_info (t, args);
8693 if (TREE_CODE (decl) == TYPE_DECL)
8696 ++processing_template_decl;
8697 new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8698 --processing_template_decl;
8699 if (new_type == error_mark_node)
8700 RETURN (error_mark_node);
8702 TREE_TYPE (r) = new_type;
8703 CLASSTYPE_TI_TEMPLATE (new_type) = r;
8704 DECL_TEMPLATE_RESULT (r) = TYPE_MAIN_DECL (new_type);
8705 DECL_TI_ARGS (r) = CLASSTYPE_TI_ARGS (new_type);
8706 DECL_CONTEXT (r) = TYPE_CONTEXT (new_type);
8711 ++processing_template_decl;
8712 new_decl = tsubst (decl, args, complain, in_decl);
8713 --processing_template_decl;
8714 if (new_decl == error_mark_node)
8715 RETURN (error_mark_node);
8717 DECL_TEMPLATE_RESULT (r) = new_decl;
8718 DECL_TI_TEMPLATE (new_decl) = r;
8719 TREE_TYPE (r) = TREE_TYPE (new_decl);
8720 DECL_TI_ARGS (r) = DECL_TI_ARGS (new_decl);
8721 DECL_CONTEXT (r) = DECL_CONTEXT (new_decl);
8724 SET_DECL_IMPLICIT_INSTANTIATION (r);
8725 DECL_TEMPLATE_INSTANTIATIONS (r) = NULL_TREE;
8726 DECL_TEMPLATE_SPECIALIZATIONS (r) = NULL_TREE;
8728 /* The template parameters for this new template are all the
8729 template parameters for the old template, except the
8730 outermost level of parameters. */
8731 DECL_TEMPLATE_PARMS (r)
8732 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
8735 if (PRIMARY_TEMPLATE_P (t))
8736 DECL_PRIMARY_TEMPLATE (r) = r;
8738 if (TREE_CODE (decl) != TYPE_DECL)
8739 /* Record this non-type partial instantiation. */
8740 register_specialization (r, t,
8741 DECL_TI_ARGS (DECL_TEMPLATE_RESULT (r)),
8749 tree argvec = NULL_TREE;
8757 /* Nobody should be tsubst'ing into non-template functions. */
8758 gcc_assert (DECL_TEMPLATE_INFO (t) != NULL_TREE);
8760 if (TREE_CODE (DECL_TI_TEMPLATE (t)) == TEMPLATE_DECL)
8765 /* If T is not dependent, just return it. We have to
8766 increment PROCESSING_TEMPLATE_DECL because
8767 value_dependent_expression_p assumes that nothing is
8768 dependent when PROCESSING_TEMPLATE_DECL is zero. */
8769 ++processing_template_decl;
8770 dependent_p = value_dependent_expression_p (t);
8771 --processing_template_decl;
8775 /* Calculate the most general template of which R is a
8776 specialization, and the complete set of arguments used to
8778 gen_tmpl = most_general_template (DECL_TI_TEMPLATE (t));
8779 argvec = tsubst_template_args (DECL_TI_ARGS
8780 (DECL_TEMPLATE_RESULT (gen_tmpl)),
8781 args, complain, in_decl);
8783 /* Check to see if we already have this specialization. */
8784 hash = hash_tmpl_and_args (gen_tmpl, argvec);
8785 spec = retrieve_specialization (gen_tmpl, argvec, hash);
8793 /* We can see more levels of arguments than parameters if
8794 there was a specialization of a member template, like
8797 template <class T> struct S { template <class U> void f(); }
8798 template <> template <class U> void S<int>::f(U);
8800 Here, we'll be substituting into the specialization,
8801 because that's where we can find the code we actually
8802 want to generate, but we'll have enough arguments for
8803 the most general template.
8805 We also deal with the peculiar case:
8807 template <class T> struct S {
8808 template <class U> friend void f();
8810 template <class U> void f() {}
8812 template void f<double>();
8814 Here, the ARGS for the instantiation of will be {int,
8815 double}. But, we only need as many ARGS as there are
8816 levels of template parameters in CODE_PATTERN. We are
8817 careful not to get fooled into reducing the ARGS in
8820 template <class T> struct S { template <class U> void f(U); }
8821 template <class T> template <> void S<T>::f(int) {}
8823 which we can spot because the pattern will be a
8824 specialization in this case. */
8825 args_depth = TMPL_ARGS_DEPTH (args);
8827 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (t)));
8828 if (args_depth > parms_depth
8829 && !DECL_TEMPLATE_SPECIALIZATION (t))
8830 args = get_innermost_template_args (args, parms_depth);
8834 /* This special case arises when we have something like this:
8836 template <class T> struct S {
8837 friend void f<int>(int, double);
8840 Here, the DECL_TI_TEMPLATE for the friend declaration
8841 will be an IDENTIFIER_NODE. We are being called from
8842 tsubst_friend_function, and we want only to create a
8843 new decl (R) with appropriate types so that we can call
8844 determine_specialization. */
8845 gen_tmpl = NULL_TREE;
8848 if (DECL_CLASS_SCOPE_P (t))
8850 if (DECL_NAME (t) == constructor_name (DECL_CONTEXT (t)))
8854 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args,
8855 complain, t, /*entering_scope=*/1);
8860 ctx = DECL_CONTEXT (t);
8862 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8863 if (type == error_mark_node)
8864 RETURN (error_mark_node);
8866 /* We do NOT check for matching decls pushed separately at this
8867 point, as they may not represent instantiations of this
8868 template, and in any case are considered separate under the
8871 DECL_USE_TEMPLATE (r) = 0;
8872 TREE_TYPE (r) = type;
8873 /* Clear out the mangled name and RTL for the instantiation. */
8874 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
8875 SET_DECL_RTL (r, NULL_RTX);
8876 /* Leave DECL_INITIAL set on deleted instantiations. */
8877 if (!DECL_DELETED_FN (r))
8878 DECL_INITIAL (r) = NULL_TREE;
8879 DECL_CONTEXT (r) = ctx;
8881 if (member && DECL_CONV_FN_P (r))
8882 /* Type-conversion operator. Reconstruct the name, in
8883 case it's the name of one of the template's parameters. */
8884 DECL_NAME (r) = mangle_conv_op_name_for_type (TREE_TYPE (type));
8886 DECL_ARGUMENTS (r) = tsubst (DECL_ARGUMENTS (t), args,
8888 DECL_RESULT (r) = NULL_TREE;
8890 TREE_STATIC (r) = 0;
8891 TREE_PUBLIC (r) = TREE_PUBLIC (t);
8892 DECL_EXTERNAL (r) = 1;
8893 /* If this is an instantiation of a function with internal
8894 linkage, we already know what object file linkage will be
8895 assigned to the instantiation. */
8896 DECL_INTERFACE_KNOWN (r) = !TREE_PUBLIC (r);
8897 DECL_DEFER_OUTPUT (r) = 0;
8898 TREE_CHAIN (r) = NULL_TREE;
8899 DECL_PENDING_INLINE_INFO (r) = 0;
8900 DECL_PENDING_INLINE_P (r) = 0;
8901 DECL_SAVED_TREE (r) = NULL_TREE;
8902 DECL_STRUCT_FUNCTION (r) = NULL;
8904 /* We'll re-clone as appropriate in instantiate_template. */
8905 DECL_CLONED_FUNCTION (r) = NULL_TREE;
8907 /* If we aren't complaining now, return on error before we register
8908 the specialization so that we'll complain eventually. */
8909 if ((complain & tf_error) == 0
8910 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
8911 && !grok_op_properties (r, /*complain=*/false))
8912 RETURN (error_mark_node);
8914 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
8915 this in the special friend case mentioned above where
8916 GEN_TMPL is NULL. */
8919 DECL_TEMPLATE_INFO (r)
8920 = build_template_info (gen_tmpl, argvec);
8921 SET_DECL_IMPLICIT_INSTANTIATION (r);
8922 register_specialization (r, gen_tmpl, argvec, false, hash);
8924 /* We're not supposed to instantiate default arguments
8925 until they are called, for a template. But, for a
8928 template <class T> void f ()
8929 { extern void g(int i = T()); }
8931 we should do the substitution when the template is
8932 instantiated. We handle the member function case in
8933 instantiate_class_template since the default arguments
8934 might refer to other members of the class. */
8936 && !PRIMARY_TEMPLATE_P (gen_tmpl)
8937 && !uses_template_parms (argvec))
8938 tsubst_default_arguments (r);
8941 DECL_TEMPLATE_INFO (r) = NULL_TREE;
8943 /* Copy the list of befriending classes. */
8944 for (friends = &DECL_BEFRIENDING_CLASSES (r);
8946 friends = &TREE_CHAIN (*friends))
8948 *friends = copy_node (*friends);
8949 TREE_VALUE (*friends) = tsubst (TREE_VALUE (*friends),
8954 if (DECL_CONSTRUCTOR_P (r) || DECL_DESTRUCTOR_P (r))
8956 maybe_retrofit_in_chrg (r);
8957 if (DECL_CONSTRUCTOR_P (r))
8958 grok_ctor_properties (ctx, r);
8959 /* If this is an instantiation of a member template, clone it.
8960 If it isn't, that'll be handled by
8961 clone_constructors_and_destructors. */
8962 if (PRIMARY_TEMPLATE_P (gen_tmpl))
8963 clone_function_decl (r, /*update_method_vec_p=*/0);
8965 else if ((complain & tf_error) != 0
8966 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
8967 && !grok_op_properties (r, /*complain=*/true))
8968 RETURN (error_mark_node);
8970 if (DECL_FRIEND_P (t) && DECL_FRIEND_CONTEXT (t))
8971 SET_DECL_FRIEND_CONTEXT (r,
8972 tsubst (DECL_FRIEND_CONTEXT (t),
8973 args, complain, in_decl));
8975 /* Possibly limit visibility based on template args. */
8976 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
8977 if (DECL_VISIBILITY_SPECIFIED (t))
8979 DECL_VISIBILITY_SPECIFIED (r) = 0;
8981 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
8983 determine_visibility (r);
8984 if (DECL_DEFAULTED_OUTSIDE_CLASS_P (r)
8985 && !processing_template_decl)
8986 defaulted_late_check (r);
8988 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
8989 args, complain, in_decl);
8995 tree type = NULL_TREE;
8997 tree expanded_types = NULL_TREE;
8998 tree prev_r = NULL_TREE;
8999 tree first_r = NULL_TREE;
9001 if (FUNCTION_PARAMETER_PACK_P (t))
9003 /* If there is a local specialization that isn't a
9004 parameter pack, it means that we're doing a "simple"
9005 substitution from inside tsubst_pack_expansion. Just
9006 return the local specialization (which will be a single
9008 tree spec = retrieve_local_specialization (t);
9010 && TREE_CODE (spec) == PARM_DECL
9011 && TREE_CODE (TREE_TYPE (spec)) != TYPE_PACK_EXPANSION)
9014 /* Expand the TYPE_PACK_EXPANSION that provides the types for
9015 the parameters in this function parameter pack. */
9016 expanded_types = tsubst_pack_expansion (TREE_TYPE (t), args,
9018 if (TREE_CODE (expanded_types) == TREE_VEC)
9020 len = TREE_VEC_LENGTH (expanded_types);
9022 /* Zero-length parameter packs are boring. Just substitute
9025 RETURN (tsubst (TREE_CHAIN (t), args, complain,
9030 /* All we did was update the type. Make a note of that. */
9031 type = expanded_types;
9032 expanded_types = NULL_TREE;
9036 /* Loop through all of the parameter's we'll build. When T is
9037 a function parameter pack, LEN is the number of expanded
9038 types in EXPANDED_TYPES; otherwise, LEN is 1. */
9040 for (i = 0; i < len; ++i)
9044 if (DECL_TEMPLATE_PARM_P (t))
9045 SET_DECL_TEMPLATE_PARM_P (r);
9047 /* An argument of a function parameter pack is not a parameter
9049 FUNCTION_PARAMETER_PACK_P (r) = false;
9052 /* We're on the Ith parameter of the function parameter
9055 /* Get the Ith type. */
9056 type = TREE_VEC_ELT (expanded_types, i);
9059 /* Rename the parameter to include the index. */
9061 make_ith_pack_parameter_name (DECL_NAME (r), i);
9064 /* We're dealing with a normal parameter. */
9065 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9067 type = type_decays_to (type);
9068 TREE_TYPE (r) = type;
9069 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
9071 if (DECL_INITIAL (r))
9073 if (TREE_CODE (DECL_INITIAL (r)) != TEMPLATE_PARM_INDEX)
9074 DECL_INITIAL (r) = TREE_TYPE (r);
9076 DECL_INITIAL (r) = tsubst (DECL_INITIAL (r), args,
9080 DECL_CONTEXT (r) = NULL_TREE;
9082 if (!DECL_TEMPLATE_PARM_P (r))
9083 DECL_ARG_TYPE (r) = type_passed_as (type);
9085 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
9086 args, complain, in_decl);
9088 /* Keep track of the first new parameter we
9089 generate. That's what will be returned to the
9094 /* Build a proper chain of parameters when substituting
9095 into a function parameter pack. */
9097 TREE_CHAIN (prev_r) = r;
9101 TREE_CHAIN (r) = tsubst (TREE_CHAIN (t), args,
9102 complain, TREE_CHAIN (t));
9104 /* FIRST_R contains the start of the chain we've built. */
9114 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9115 if (type == error_mark_node)
9116 RETURN (error_mark_node);
9117 TREE_TYPE (r) = type;
9118 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
9120 /* DECL_INITIAL gives the number of bits in a bit-field. */
9122 = tsubst_expr (DECL_INITIAL (t), args,
9124 /*integral_constant_expression_p=*/true);
9125 /* We don't have to set DECL_CONTEXT here; it is set by
9126 finish_member_declaration. */
9127 TREE_CHAIN (r) = NULL_TREE;
9128 if (VOID_TYPE_P (type))
9129 error ("instantiation of %q+D as type %qT", r, type);
9131 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
9132 args, complain, in_decl);
9137 /* We reach here only for member using decls. */
9138 if (DECL_DEPENDENT_P (t))
9140 r = do_class_using_decl
9141 (tsubst_copy (USING_DECL_SCOPE (t), args, complain, in_decl),
9142 tsubst_copy (DECL_NAME (t), args, complain, in_decl));
9144 r = error_mark_node;
9147 TREE_PROTECTED (r) = TREE_PROTECTED (t);
9148 TREE_PRIVATE (r) = TREE_PRIVATE (t);
9154 TREE_CHAIN (r) = NULL_TREE;
9161 tree argvec = NULL_TREE;
9162 tree gen_tmpl = NULL_TREE;
9164 tree tmpl = NULL_TREE;
9166 tree type = NULL_TREE;
9169 if (TREE_CODE (t) == TYPE_DECL
9170 && t == TYPE_MAIN_DECL (TREE_TYPE (t)))
9172 /* If this is the canonical decl, we don't have to
9173 mess with instantiations, and often we can't (for
9174 typename, template type parms and such). Note that
9175 TYPE_NAME is not correct for the above test if
9176 we've copied the type for a typedef. */
9177 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9178 if (type == error_mark_node)
9179 RETURN (error_mark_node);
9180 r = TYPE_NAME (type);
9184 /* Check to see if we already have the specialization we
9187 if (DECL_CLASS_SCOPE_P (t) || DECL_NAMESPACE_SCOPE_P (t))
9189 /* T is a static data member or namespace-scope entity.
9190 We have to substitute into namespace-scope variables
9191 (even though such entities are never templates) because
9194 template <class T> void f() { extern T t; }
9196 where the entity referenced is not known until
9197 instantiation time. */
9199 ctx = DECL_CONTEXT (t);
9200 if (DECL_CLASS_SCOPE_P (t))
9202 ctx = tsubst_aggr_type (ctx, args,
9204 in_decl, /*entering_scope=*/1);
9205 /* If CTX is unchanged, then T is in fact the
9206 specialization we want. That situation occurs when
9207 referencing a static data member within in its own
9208 class. We can use pointer equality, rather than
9209 same_type_p, because DECL_CONTEXT is always
9211 if (ctx == DECL_CONTEXT (t))
9217 tmpl = DECL_TI_TEMPLATE (t);
9218 gen_tmpl = most_general_template (tmpl);
9219 argvec = tsubst (DECL_TI_ARGS (t), args, complain, in_decl);
9220 hash = hash_tmpl_and_args (gen_tmpl, argvec);
9221 spec = retrieve_specialization (gen_tmpl, argvec, hash);
9226 /* A local variable. */
9228 /* Subsequent calls to pushdecl will fill this in. */
9230 spec = retrieve_local_specialization (t);
9232 /* If we already have the specialization we need, there is
9233 nothing more to do. */
9240 /* Create a new node for the specialization we need. */
9242 if (type == NULL_TREE)
9243 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9244 if (TREE_CODE (r) == VAR_DECL)
9246 /* Even if the original location is out of scope, the
9247 newly substituted one is not. */
9248 DECL_DEAD_FOR_LOCAL (r) = 0;
9249 DECL_INITIALIZED_P (r) = 0;
9250 DECL_TEMPLATE_INSTANTIATED (r) = 0;
9251 if (type == error_mark_node)
9252 RETURN (error_mark_node);
9253 if (TREE_CODE (type) == FUNCTION_TYPE)
9255 /* It may seem that this case cannot occur, since:
9260 declares a function, not a variable. However:
9263 template <typename T> void g() { T t; }
9264 template void g<f>();
9266 is an attempt to declare a variable with function
9268 error ("variable %qD has function type",
9269 /* R is not yet sufficiently initialized, so we
9270 just use its name. */
9272 RETURN (error_mark_node);
9274 type = complete_type (type);
9275 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r)
9276 = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (t);
9277 type = check_var_type (DECL_NAME (r), type);
9279 if (DECL_HAS_VALUE_EXPR_P (t))
9281 tree ve = DECL_VALUE_EXPR (t);
9282 ve = tsubst_expr (ve, args, complain, in_decl,
9283 /*constant_expression_p=*/false);
9284 SET_DECL_VALUE_EXPR (r, ve);
9287 else if (DECL_SELF_REFERENCE_P (t))
9288 SET_DECL_SELF_REFERENCE_P (r);
9289 TREE_TYPE (r) = type;
9290 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
9291 DECL_CONTEXT (r) = ctx;
9292 /* Clear out the mangled name and RTL for the instantiation. */
9293 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
9294 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
9295 SET_DECL_RTL (r, NULL_RTX);
9296 /* The initializer must not be expanded until it is required;
9298 DECL_INITIAL (r) = NULL_TREE;
9299 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
9300 SET_DECL_RTL (r, NULL_RTX);
9301 DECL_SIZE (r) = DECL_SIZE_UNIT (r) = 0;
9302 if (TREE_CODE (r) == VAR_DECL)
9304 /* Possibly limit visibility based on template args. */
9305 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
9306 if (DECL_VISIBILITY_SPECIFIED (t))
9308 DECL_VISIBILITY_SPECIFIED (r) = 0;
9310 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
9312 determine_visibility (r);
9314 /* Preserve a typedef that names a type. */
9315 else if (TREE_CODE (r) == TYPE_DECL
9316 && DECL_ORIGINAL_TYPE (t)
9317 && type != error_mark_node)
9319 DECL_ORIGINAL_TYPE (r) = tsubst (DECL_ORIGINAL_TYPE (t),
9320 args, complain, in_decl);
9321 TREE_TYPE (r) = type = build_variant_type_copy (type);
9322 TYPE_NAME (type) = r;
9327 /* A static data member declaration is always marked
9328 external when it is declared in-class, even if an
9329 initializer is present. We mimic the non-template
9331 DECL_EXTERNAL (r) = 1;
9333 register_specialization (r, gen_tmpl, argvec, false, hash);
9334 DECL_TEMPLATE_INFO (r) = build_template_info (tmpl, argvec);
9335 SET_DECL_IMPLICIT_INSTANTIATION (r);
9337 else if (cp_unevaluated_operand)
9339 /* We're substituting this var in a decltype outside of its
9340 scope, such as for a lambda return type. Don't add it to
9341 local_specializations, do perform auto deduction. */
9342 tree auto_node = type_uses_auto (type);
9344 = tsubst_expr (DECL_INITIAL (t), args, complain, in_decl,
9345 /*constant_expression_p=*/false);
9347 if (auto_node && init && describable_type (init))
9349 type = do_auto_deduction (type, init, auto_node);
9350 TREE_TYPE (r) = type;
9354 register_local_specialization (r, t);
9356 TREE_CHAIN (r) = NULL_TREE;
9358 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r),
9359 (int) ATTR_FLAG_TYPE_IN_PLACE,
9360 args, complain, in_decl);
9371 /* Restore the file and line information. */
9372 input_location = saved_loc;
9377 /* Substitute into the ARG_TYPES of a function type. */
9380 tsubst_arg_types (tree arg_types,
9382 tsubst_flags_t complain,
9385 tree remaining_arg_types;
9386 tree type = NULL_TREE;
9388 tree expanded_args = NULL_TREE;
9391 if (!arg_types || arg_types == void_list_node)
9394 remaining_arg_types = tsubst_arg_types (TREE_CHAIN (arg_types),
9395 args, complain, in_decl);
9396 if (remaining_arg_types == error_mark_node)
9397 return error_mark_node;
9399 if (PACK_EXPANSION_P (TREE_VALUE (arg_types)))
9401 /* For a pack expansion, perform substitution on the
9402 entire expression. Later on, we'll handle the arguments
9404 expanded_args = tsubst_pack_expansion (TREE_VALUE (arg_types),
9405 args, complain, in_decl);
9407 if (TREE_CODE (expanded_args) == TREE_VEC)
9408 /* So that we'll spin through the parameters, one by one. */
9409 i = TREE_VEC_LENGTH (expanded_args);
9412 /* We only partially substituted into the parameter
9413 pack. Our type is TYPE_PACK_EXPANSION. */
9414 type = expanded_args;
9415 expanded_args = NULL_TREE;
9423 type = TREE_VEC_ELT (expanded_args, i);
9425 type = tsubst (TREE_VALUE (arg_types), args, complain, in_decl);
9427 if (type == error_mark_node)
9428 return error_mark_node;
9429 if (VOID_TYPE_P (type))
9431 if (complain & tf_error)
9433 error ("invalid parameter type %qT", type);
9435 error ("in declaration %q+D", in_decl);
9437 return error_mark_node;
9440 /* Do array-to-pointer, function-to-pointer conversion, and ignore
9441 top-level qualifiers as required. */
9442 type = TYPE_MAIN_VARIANT (type_decays_to (type));
9444 /* We do not substitute into default arguments here. The standard
9445 mandates that they be instantiated only when needed, which is
9446 done in build_over_call. */
9447 default_arg = TREE_PURPOSE (arg_types);
9449 if (default_arg && TREE_CODE (default_arg) == DEFAULT_ARG)
9451 /* We've instantiated a template before its default arguments
9452 have been parsed. This can happen for a nested template
9453 class, and is not an error unless we require the default
9454 argument in a call of this function. */
9455 remaining_arg_types =
9456 tree_cons (default_arg, type, remaining_arg_types);
9457 VEC_safe_push (tree, gc, DEFARG_INSTANTIATIONS (default_arg),
9458 remaining_arg_types);
9461 remaining_arg_types =
9462 hash_tree_cons (default_arg, type, remaining_arg_types);
9465 return remaining_arg_types;
9468 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
9469 *not* handle the exception-specification for FNTYPE, because the
9470 initial substitution of explicitly provided template parameters
9471 during argument deduction forbids substitution into the
9472 exception-specification:
9476 All references in the function type of the function template to the
9477 corresponding template parameters are replaced by the specified tem-
9478 plate argument values. If a substitution in a template parameter or
9479 in the function type of the function template results in an invalid
9480 type, type deduction fails. [Note: The equivalent substitution in
9481 exception specifications is done only when the function is instanti-
9482 ated, at which point a program is ill-formed if the substitution
9483 results in an invalid type.] */
9486 tsubst_function_type (tree t,
9488 tsubst_flags_t complain,
9495 /* The TYPE_CONTEXT is not used for function/method types. */
9496 gcc_assert (TYPE_CONTEXT (t) == NULL_TREE);
9498 /* Substitute the return type. */
9499 return_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9500 if (return_type == error_mark_node)
9501 return error_mark_node;
9502 /* The standard does not presently indicate that creation of a
9503 function type with an invalid return type is a deduction failure.
9504 However, that is clearly analogous to creating an array of "void"
9505 or a reference to a reference. This is core issue #486. */
9506 if (TREE_CODE (return_type) == ARRAY_TYPE
9507 || TREE_CODE (return_type) == FUNCTION_TYPE)
9509 if (complain & tf_error)
9511 if (TREE_CODE (return_type) == ARRAY_TYPE)
9512 error ("function returning an array");
9514 error ("function returning a function");
9516 return error_mark_node;
9519 /* Substitute the argument types. */
9520 arg_types = tsubst_arg_types (TYPE_ARG_TYPES (t), args,
9522 if (arg_types == error_mark_node)
9523 return error_mark_node;
9525 /* Construct a new type node and return it. */
9526 if (TREE_CODE (t) == FUNCTION_TYPE)
9527 fntype = build_function_type (return_type, arg_types);
9530 tree r = TREE_TYPE (TREE_VALUE (arg_types));
9531 if (! MAYBE_CLASS_TYPE_P (r))
9535 Type deduction may fail for any of the following
9538 -- Attempting to create "pointer to member of T" when T
9539 is not a class type. */
9540 if (complain & tf_error)
9541 error ("creating pointer to member function of non-class type %qT",
9543 return error_mark_node;
9546 fntype = build_method_type_directly (r, return_type,
9547 TREE_CHAIN (arg_types));
9549 fntype = cp_build_qualified_type_real (fntype, TYPE_QUALS (t), complain);
9550 fntype = cp_build_type_attribute_variant (fntype, TYPE_ATTRIBUTES (t));
9555 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
9556 ARGS into that specification, and return the substituted
9557 specification. If there is no specification, return NULL_TREE. */
9560 tsubst_exception_specification (tree fntype,
9562 tsubst_flags_t complain,
9568 specs = TYPE_RAISES_EXCEPTIONS (fntype);
9569 new_specs = NULL_TREE;
9572 if (! TREE_VALUE (specs))
9579 tree expanded_specs = NULL_TREE;
9581 if (PACK_EXPANSION_P (TREE_VALUE (specs)))
9583 /* Expand the pack expansion type. */
9584 expanded_specs = tsubst_pack_expansion (TREE_VALUE (specs),
9588 if (expanded_specs == error_mark_node)
9589 return error_mark_node;
9590 else if (TREE_CODE (expanded_specs) == TREE_VEC)
9591 len = TREE_VEC_LENGTH (expanded_specs);
9594 /* We're substituting into a member template, so
9595 we got a TYPE_PACK_EXPANSION back. Add that
9596 expansion and move on. */
9597 gcc_assert (TREE_CODE (expanded_specs)
9598 == TYPE_PACK_EXPANSION);
9599 new_specs = add_exception_specifier (new_specs,
9602 specs = TREE_CHAIN (specs);
9607 for (i = 0; i < len; ++i)
9610 spec = TREE_VEC_ELT (expanded_specs, i);
9612 spec = tsubst (TREE_VALUE (specs), args, complain, in_decl);
9613 if (spec == error_mark_node)
9615 new_specs = add_exception_specifier (new_specs, spec,
9619 specs = TREE_CHAIN (specs);
9625 /* Take the tree structure T and replace template parameters used
9626 therein with the argument vector ARGS. IN_DECL is an associated
9627 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
9628 Issue error and warning messages under control of COMPLAIN. Note
9629 that we must be relatively non-tolerant of extensions here, in
9630 order to preserve conformance; if we allow substitutions that
9631 should not be allowed, we may allow argument deductions that should
9632 not succeed, and therefore report ambiguous overload situations
9633 where there are none. In theory, we could allow the substitution,
9634 but indicate that it should have failed, and allow our caller to
9635 make sure that the right thing happens, but we don't try to do this
9638 This function is used for dealing with types, decls and the like;
9639 for expressions, use tsubst_expr or tsubst_copy. */
9642 tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl)
9646 if (t == NULL_TREE || t == error_mark_node
9647 || t == integer_type_node
9648 || t == void_type_node
9649 || t == char_type_node
9650 || t == unknown_type_node
9651 || TREE_CODE (t) == NAMESPACE_DECL)
9655 return tsubst_decl (t, args, complain);
9657 if (args == NULL_TREE)
9660 if (TREE_CODE (t) == IDENTIFIER_NODE)
9661 type = IDENTIFIER_TYPE_VALUE (t);
9663 type = TREE_TYPE (t);
9665 gcc_assert (type != unknown_type_node);
9667 /* Reuse typedefs. We need to do this to handle dependent attributes,
9668 such as attribute aligned. */
9671 && TYPE_NAME (t) != TYPE_MAIN_DECL (t))
9673 tree decl = TYPE_NAME (t);
9675 if (DECL_CLASS_SCOPE_P (decl)
9676 && CLASSTYPE_TEMPLATE_INFO (DECL_CONTEXT (decl))
9677 && uses_template_parms (DECL_CONTEXT (decl)))
9679 tree tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
9680 tree gen_args = tsubst (DECL_TI_ARGS (decl), args, complain, in_decl);
9681 r = retrieve_specialization (tmpl, gen_args, 0);
9683 else if (DECL_FUNCTION_SCOPE_P (decl)
9684 && DECL_TEMPLATE_INFO (DECL_CONTEXT (decl))
9685 && uses_template_parms (DECL_TI_ARGS (DECL_CONTEXT (decl))))
9686 r = retrieve_local_specialization (decl);
9688 /* The typedef is from a non-template context. */
9694 r = cp_build_qualified_type_real
9695 (r, cp_type_quals (t) | cp_type_quals (r),
9696 complain | tf_ignore_bad_quals);
9699 /* Else we must be instantiating the typedef, so fall through. */
9703 && TREE_CODE (t) != TYPENAME_TYPE
9704 && TREE_CODE (t) != IDENTIFIER_NODE
9705 && TREE_CODE (t) != FUNCTION_TYPE
9706 && TREE_CODE (t) != METHOD_TYPE)
9707 type = tsubst (type, args, complain, in_decl);
9708 if (type == error_mark_node)
9709 return error_mark_node;
9711 switch (TREE_CODE (t))
9716 return tsubst_aggr_type (t, args, complain, in_decl,
9717 /*entering_scope=*/0);
9720 case IDENTIFIER_NODE:
9732 if (t == integer_type_node)
9735 if (TREE_CODE (TYPE_MIN_VALUE (t)) == INTEGER_CST
9736 && TREE_CODE (TYPE_MAX_VALUE (t)) == INTEGER_CST)
9740 tree max, omax = TREE_OPERAND (TYPE_MAX_VALUE (t), 0);
9742 max = tsubst_expr (omax, args, complain, in_decl,
9743 /*integral_constant_expression_p=*/false);
9745 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
9747 if (TREE_CODE (max) == NOP_EXPR
9748 && TREE_SIDE_EFFECTS (omax)
9749 && !TREE_TYPE (max))
9750 TREE_TYPE (max) = TREE_TYPE (TREE_OPERAND (max, 0));
9752 max = fold_decl_constant_value (max);
9754 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
9755 with TREE_SIDE_EFFECTS that indicates this is not an integral
9756 constant expression. */
9757 if (processing_template_decl
9758 && TREE_SIDE_EFFECTS (omax) && TREE_CODE (omax) == NOP_EXPR)
9760 gcc_assert (TREE_CODE (max) == NOP_EXPR);
9761 TREE_SIDE_EFFECTS (max) = 1;
9764 if (TREE_CODE (max) != INTEGER_CST
9765 && !at_function_scope_p ()
9766 && !TREE_SIDE_EFFECTS (max)
9767 && !value_dependent_expression_p (max))
9769 if (complain & tf_error)
9770 error ("array bound is not an integer constant");
9771 return error_mark_node;
9776 Type deduction may fail for any of the following
9779 Attempting to create an array with a size that is
9780 zero or negative. */
9781 if (integer_zerop (max) && !(complain & tf_error))
9782 /* We must fail if performing argument deduction (as
9783 indicated by the state of complain), so that
9784 another substitution can be found. */
9785 return error_mark_node;
9786 else if (TREE_CODE (max) == INTEGER_CST
9787 && INT_CST_LT (max, integer_zero_node))
9789 if (complain & tf_error)
9790 error ("creating array with negative size (%qE)", max);
9792 return error_mark_node;
9795 return compute_array_index_type (NULL_TREE, max);
9798 case TEMPLATE_TYPE_PARM:
9799 case TEMPLATE_TEMPLATE_PARM:
9800 case BOUND_TEMPLATE_TEMPLATE_PARM:
9801 case TEMPLATE_PARM_INDEX:
9806 tree arg = NULL_TREE;
9810 gcc_assert (TREE_VEC_LENGTH (args) > 0);
9811 template_parm_level_and_index (t, &level, &idx);
9813 levels = TMPL_ARGS_DEPTH (args);
9814 if (level <= levels)
9816 arg = TMPL_ARG (args, level, idx);
9818 if (arg && TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
9819 /* See through ARGUMENT_PACK_SELECT arguments. */
9820 arg = ARGUMENT_PACK_SELECT_ARG (arg);
9823 if (arg == error_mark_node)
9824 return error_mark_node;
9825 else if (arg != NULL_TREE)
9827 if (ARGUMENT_PACK_P (arg))
9828 /* If ARG is an argument pack, we don't actually want to
9829 perform a substitution here, because substitutions
9830 for argument packs are only done
9831 element-by-element. We can get to this point when
9832 substituting the type of a non-type template
9833 parameter pack, when that type actually contains
9834 template parameter packs from an outer template, e.g.,
9836 template<typename... Types> struct A {
9837 template<Types... Values> struct B { };
9841 if (TREE_CODE (t) == TEMPLATE_TYPE_PARM)
9844 gcc_assert (TYPE_P (arg));
9846 /* cv-quals from the template are discarded when
9847 substituting in a function or reference type. */
9848 if (TREE_CODE (arg) == FUNCTION_TYPE
9849 || TREE_CODE (arg) == METHOD_TYPE
9850 || TREE_CODE (arg) == REFERENCE_TYPE)
9851 quals = cp_type_quals (arg);
9853 quals = cp_type_quals (arg) | cp_type_quals (t);
9855 return cp_build_qualified_type_real
9856 (arg, quals, complain | tf_ignore_bad_quals);
9858 else if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
9860 /* We are processing a type constructed from a
9861 template template parameter. */
9862 tree argvec = tsubst (TYPE_TI_ARGS (t),
9863 args, complain, in_decl);
9864 if (argvec == error_mark_node)
9865 return error_mark_node;
9867 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
9868 are resolving nested-types in the signature of a
9869 member function templates. Otherwise ARG is a
9870 TEMPLATE_DECL and is the real template to be
9872 if (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
9873 arg = TYPE_NAME (arg);
9875 r = lookup_template_class (arg,
9878 /*entering_scope=*/0,
9880 return cp_build_qualified_type_real
9881 (r, TYPE_QUALS (t), complain);
9884 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
9889 /* This can happen during the attempted tsubst'ing in
9890 unify. This means that we don't yet have any information
9891 about the template parameter in question. */
9894 /* If we get here, we must have been looking at a parm for a
9895 more deeply nested template. Make a new version of this
9896 template parameter, but with a lower level. */
9897 switch (TREE_CODE (t))
9899 case TEMPLATE_TYPE_PARM:
9900 case TEMPLATE_TEMPLATE_PARM:
9901 case BOUND_TEMPLATE_TEMPLATE_PARM:
9902 if (cp_type_quals (t))
9904 r = tsubst (TYPE_MAIN_VARIANT (t), args, complain, in_decl);
9905 r = cp_build_qualified_type_real
9906 (r, cp_type_quals (t),
9907 complain | (TREE_CODE (t) == TEMPLATE_TYPE_PARM
9908 ? tf_ignore_bad_quals : 0));
9913 TEMPLATE_TYPE_PARM_INDEX (r)
9914 = reduce_template_parm_level (TEMPLATE_TYPE_PARM_INDEX (t),
9915 r, levels, args, complain);
9916 TYPE_STUB_DECL (r) = TYPE_NAME (r) = TEMPLATE_TYPE_DECL (r);
9917 TYPE_MAIN_VARIANT (r) = r;
9918 TYPE_POINTER_TO (r) = NULL_TREE;
9919 TYPE_REFERENCE_TO (r) = NULL_TREE;
9921 if (TREE_CODE (r) == TEMPLATE_TEMPLATE_PARM)
9922 /* We have reduced the level of the template
9923 template parameter, but not the levels of its
9924 template parameters, so canonical_type_parameter
9925 will not be able to find the canonical template
9926 template parameter for this level. Thus, we
9927 require structural equality checking to compare
9928 TEMPLATE_TEMPLATE_PARMs. */
9929 SET_TYPE_STRUCTURAL_EQUALITY (r);
9930 else if (TYPE_STRUCTURAL_EQUALITY_P (t))
9931 SET_TYPE_STRUCTURAL_EQUALITY (r);
9933 TYPE_CANONICAL (r) = canonical_type_parameter (r);
9935 if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
9937 tree argvec = tsubst (TYPE_TI_ARGS (t), args,
9939 if (argvec == error_mark_node)
9940 return error_mark_node;
9942 TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (r)
9943 = build_template_info (TYPE_TI_TEMPLATE (t), argvec);
9948 case TEMPLATE_PARM_INDEX:
9949 r = reduce_template_parm_level (t, type, levels, args, complain);
9961 tree purpose, value, chain;
9963 if (t == void_list_node)
9966 purpose = TREE_PURPOSE (t);
9969 purpose = tsubst (purpose, args, complain, in_decl);
9970 if (purpose == error_mark_node)
9971 return error_mark_node;
9973 value = TREE_VALUE (t);
9976 value = tsubst (value, args, complain, in_decl);
9977 if (value == error_mark_node)
9978 return error_mark_node;
9980 chain = TREE_CHAIN (t);
9981 if (chain && chain != void_type_node)
9983 chain = tsubst (chain, args, complain, in_decl);
9984 if (chain == error_mark_node)
9985 return error_mark_node;
9987 if (purpose == TREE_PURPOSE (t)
9988 && value == TREE_VALUE (t)
9989 && chain == TREE_CHAIN (t))
9991 return hash_tree_cons (purpose, value, chain);
9995 /* We should never be tsubsting a binfo. */
9999 /* A vector of template arguments. */
10000 gcc_assert (!type);
10001 return tsubst_template_args (t, args, complain, in_decl);
10004 case REFERENCE_TYPE:
10006 enum tree_code code;
10008 if (type == TREE_TYPE (t) && TREE_CODE (type) != METHOD_TYPE)
10011 code = TREE_CODE (t);
10016 Type deduction may fail for any of the following
10019 -- Attempting to create a pointer to reference type.
10020 -- Attempting to create a reference to a reference type or
10021 a reference to void.
10023 Core issue 106 says that creating a reference to a reference
10024 during instantiation is no longer a cause for failure. We
10025 only enforce this check in strict C++98 mode. */
10026 if ((TREE_CODE (type) == REFERENCE_TYPE
10027 && (((cxx_dialect == cxx98) && flag_iso) || code != REFERENCE_TYPE))
10028 || (code == REFERENCE_TYPE && TREE_CODE (type) == VOID_TYPE))
10030 static location_t last_loc;
10032 /* We keep track of the last time we issued this error
10033 message to avoid spewing a ton of messages during a
10034 single bad template instantiation. */
10035 if (complain & tf_error
10036 && last_loc != input_location)
10038 if (TREE_CODE (type) == VOID_TYPE)
10039 error ("forming reference to void");
10041 error ("forming %s to reference type %qT",
10042 (code == POINTER_TYPE) ? "pointer" : "reference",
10044 last_loc = input_location;
10047 return error_mark_node;
10049 else if (code == POINTER_TYPE)
10051 r = build_pointer_type (type);
10052 if (TREE_CODE (type) == METHOD_TYPE)
10053 r = build_ptrmemfunc_type (r);
10055 else if (TREE_CODE (type) == REFERENCE_TYPE)
10056 /* In C++0x, during template argument substitution, when there is an
10057 attempt to create a reference to a reference type, reference
10058 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
10060 "If a template-argument for a template-parameter T names a type
10061 that is a reference to a type A, an attempt to create the type
10062 'lvalue reference to cv T' creates the type 'lvalue reference to
10063 A,' while an attempt to create the type type rvalue reference to
10064 cv T' creates the type T"
10066 r = cp_build_reference_type
10068 TYPE_REF_IS_RVALUE (t) && TYPE_REF_IS_RVALUE (type));
10070 r = cp_build_reference_type (type, TYPE_REF_IS_RVALUE (t));
10071 r = cp_build_qualified_type_real (r, TYPE_QUALS (t), complain);
10073 if (r != error_mark_node)
10074 /* Will this ever be needed for TYPE_..._TO values? */
10081 r = tsubst (TYPE_OFFSET_BASETYPE (t), args, complain, in_decl);
10082 if (r == error_mark_node || !MAYBE_CLASS_TYPE_P (r))
10086 Type deduction may fail for any of the following
10089 -- Attempting to create "pointer to member of T" when T
10090 is not a class type. */
10091 if (complain & tf_error)
10092 error ("creating pointer to member of non-class type %qT", r);
10093 return error_mark_node;
10095 if (TREE_CODE (type) == REFERENCE_TYPE)
10097 if (complain & tf_error)
10098 error ("creating pointer to member reference type %qT", type);
10099 return error_mark_node;
10101 if (TREE_CODE (type) == VOID_TYPE)
10103 if (complain & tf_error)
10104 error ("creating pointer to member of type void");
10105 return error_mark_node;
10107 gcc_assert (TREE_CODE (type) != METHOD_TYPE);
10108 if (TREE_CODE (type) == FUNCTION_TYPE)
10110 /* The type of the implicit object parameter gets its
10111 cv-qualifiers from the FUNCTION_TYPE. */
10113 tree method_type = build_memfn_type (type, r, cp_type_quals (type));
10114 memptr = build_ptrmemfunc_type (build_pointer_type (method_type));
10115 return cp_build_qualified_type_real (memptr, cp_type_quals (t),
10119 return cp_build_qualified_type_real (build_ptrmem_type (r, type),
10123 case FUNCTION_TYPE:
10128 fntype = tsubst_function_type (t, args, complain, in_decl);
10129 if (fntype == error_mark_node)
10130 return error_mark_node;
10132 /* Substitute the exception specification. */
10133 specs = tsubst_exception_specification (t, args, complain,
10135 if (specs == error_mark_node)
10136 return error_mark_node;
10138 fntype = build_exception_variant (fntype, specs);
10143 tree domain = tsubst (TYPE_DOMAIN (t), args, complain, in_decl);
10144 if (domain == error_mark_node)
10145 return error_mark_node;
10147 /* As an optimization, we avoid regenerating the array type if
10148 it will obviously be the same as T. */
10149 if (type == TREE_TYPE (t) && domain == TYPE_DOMAIN (t))
10152 /* These checks should match the ones in grokdeclarator.
10156 The deduction may fail for any of the following reasons:
10158 -- Attempting to create an array with an element type that
10159 is void, a function type, or a reference type, or [DR337]
10160 an abstract class type. */
10161 if (TREE_CODE (type) == VOID_TYPE
10162 || TREE_CODE (type) == FUNCTION_TYPE
10163 || TREE_CODE (type) == REFERENCE_TYPE)
10165 if (complain & tf_error)
10166 error ("creating array of %qT", type);
10167 return error_mark_node;
10169 if (CLASS_TYPE_P (type) && CLASSTYPE_PURE_VIRTUALS (type))
10171 if (complain & tf_error)
10172 error ("creating array of %qT, which is an abstract class type",
10174 return error_mark_node;
10177 r = build_cplus_array_type (type, domain);
10179 if (TYPE_USER_ALIGN (t))
10181 TYPE_ALIGN (r) = TYPE_ALIGN (t);
10182 TYPE_USER_ALIGN (r) = 1;
10191 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
10192 tree e2 = tsubst (TREE_OPERAND (t, 1), args, complain, in_decl);
10194 if (e1 == error_mark_node || e2 == error_mark_node)
10195 return error_mark_node;
10197 return fold_build2_loc (input_location,
10198 TREE_CODE (t), TREE_TYPE (t), e1, e2);
10204 tree e = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
10205 if (e == error_mark_node)
10206 return error_mark_node;
10208 return fold_build1_loc (input_location, TREE_CODE (t), TREE_TYPE (t), e);
10211 case TYPENAME_TYPE:
10213 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
10214 in_decl, /*entering_scope=*/1);
10215 tree f = tsubst_copy (TYPENAME_TYPE_FULLNAME (t), args,
10216 complain, in_decl);
10218 if (ctx == error_mark_node || f == error_mark_node)
10219 return error_mark_node;
10221 if (!MAYBE_CLASS_TYPE_P (ctx))
10223 if (complain & tf_error)
10224 error ("%qT is not a class, struct, or union type", ctx);
10225 return error_mark_node;
10227 else if (!uses_template_parms (ctx) && !TYPE_BEING_DEFINED (ctx))
10229 /* Normally, make_typename_type does not require that the CTX
10230 have complete type in order to allow things like:
10232 template <class T> struct S { typename S<T>::X Y; };
10234 But, such constructs have already been resolved by this
10235 point, so here CTX really should have complete type, unless
10236 it's a partial instantiation. */
10237 if (!(complain & tf_no_class_instantiations))
10238 ctx = complete_type (ctx);
10239 if (!COMPLETE_TYPE_P (ctx))
10241 if (complain & tf_error)
10242 cxx_incomplete_type_error (NULL_TREE, ctx);
10243 return error_mark_node;
10247 f = make_typename_type (ctx, f, typename_type,
10248 (complain & tf_error) | tf_keep_type_decl);
10249 if (f == error_mark_node)
10251 if (TREE_CODE (f) == TYPE_DECL)
10253 complain |= tf_ignore_bad_quals;
10257 if (TREE_CODE (f) != TYPENAME_TYPE)
10259 if (TYPENAME_IS_ENUM_P (t) && TREE_CODE (f) != ENUMERAL_TYPE)
10260 error ("%qT resolves to %qT, which is not an enumeration type",
10262 else if (TYPENAME_IS_CLASS_P (t) && !CLASS_TYPE_P (f))
10263 error ("%qT resolves to %qT, which is is not a class type",
10267 return cp_build_qualified_type_real
10268 (f, cp_type_quals (f) | cp_type_quals (t), complain);
10271 case UNBOUND_CLASS_TEMPLATE:
10273 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
10274 in_decl, /*entering_scope=*/1);
10275 tree name = TYPE_IDENTIFIER (t);
10276 tree parm_list = DECL_TEMPLATE_PARMS (TYPE_NAME (t));
10278 if (ctx == error_mark_node || name == error_mark_node)
10279 return error_mark_node;
10282 parm_list = tsubst_template_parms (parm_list, args, complain);
10283 return make_unbound_class_template (ctx, name, parm_list, complain);
10289 gcc_unreachable ();
10293 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
10294 tree e2 = tsubst_expr (TREE_OPERAND (t, 1), args, complain, in_decl,
10295 /*integral_constant_expression_p=*/false);
10296 if (e1 == error_mark_node || e2 == error_mark_node)
10297 return error_mark_node;
10299 return build_nt (ARRAY_REF, e1, e2, NULL_TREE, NULL_TREE);
10304 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
10305 tree e2 = tsubst (TREE_OPERAND (t, 1), args, complain, in_decl);
10306 if (e1 == error_mark_node || e2 == error_mark_node)
10307 return error_mark_node;
10309 return build_qualified_name (/*type=*/NULL_TREE,
10310 e1, e2, QUALIFIED_NAME_IS_TEMPLATE (t));
10317 ++cp_unevaluated_operand;
10318 ++c_inhibit_evaluation_warnings;
10320 type = tsubst_expr (TYPEOF_TYPE_EXPR (t), args,
10322 /*integral_constant_expression_p=*/false);
10324 --cp_unevaluated_operand;
10325 --c_inhibit_evaluation_warnings;
10327 type = finish_typeof (type);
10328 return cp_build_qualified_type_real (type,
10330 | cp_type_quals (type),
10334 case DECLTYPE_TYPE:
10338 ++cp_unevaluated_operand;
10339 ++c_inhibit_evaluation_warnings;
10341 type = tsubst_expr (DECLTYPE_TYPE_EXPR (t), args,
10343 /*integral_constant_expression_p=*/false);
10345 --cp_unevaluated_operand;
10346 --c_inhibit_evaluation_warnings;
10348 if (DECLTYPE_FOR_LAMBDA_CAPTURE (t))
10349 type = lambda_capture_field_type (type);
10350 else if (DECLTYPE_FOR_LAMBDA_RETURN (t))
10351 type = lambda_return_type (type);
10353 type = finish_decltype_type
10354 (type, DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t));
10355 return cp_build_qualified_type_real (type,
10357 | cp_type_quals (type),
10361 case TYPE_ARGUMENT_PACK:
10362 case NONTYPE_ARGUMENT_PACK:
10364 tree r = TYPE_P (t)
10365 ? cxx_make_type (TREE_CODE (t))
10366 : make_node (TREE_CODE (t));
10368 tsubst_template_args (ARGUMENT_PACK_ARGS (t),
10372 SET_ARGUMENT_PACK_ARGS (r, packed_out);
10374 /* For template nontype argument packs, also substitute into
10376 if (TREE_CODE (t) == NONTYPE_ARGUMENT_PACK)
10377 TREE_TYPE (r) = tsubst (TREE_TYPE (t), args, complain, in_decl);
10384 sorry ("use of %qs in template",
10385 tree_code_name [(int) TREE_CODE (t)]);
10386 return error_mark_node;
10390 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
10391 type of the expression on the left-hand side of the "." or "->"
10395 tsubst_baselink (tree baselink, tree object_type,
10396 tree args, tsubst_flags_t complain, tree in_decl)
10399 tree qualifying_scope;
10402 tree template_args = 0;
10403 bool template_id_p = false;
10405 /* A baselink indicates a function from a base class. Both the
10406 BASELINK_ACCESS_BINFO and the base class referenced may
10407 indicate bases of the template class, rather than the
10408 instantiated class. In addition, lookups that were not
10409 ambiguous before may be ambiguous now. Therefore, we perform
10410 the lookup again. */
10411 qualifying_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (baselink));
10412 qualifying_scope = tsubst (qualifying_scope, args,
10413 complain, in_decl);
10414 fns = BASELINK_FUNCTIONS (baselink);
10415 optype = tsubst (BASELINK_OPTYPE (baselink), args, complain, in_decl);
10416 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
10418 template_id_p = true;
10419 template_args = TREE_OPERAND (fns, 1);
10420 fns = TREE_OPERAND (fns, 0);
10422 template_args = tsubst_template_args (template_args, args,
10423 complain, in_decl);
10425 name = DECL_NAME (get_first_fn (fns));
10426 if (IDENTIFIER_TYPENAME_P (name))
10427 name = mangle_conv_op_name_for_type (optype);
10428 baselink = lookup_fnfields (qualifying_scope, name, /*protect=*/1);
10430 /* If lookup found a single function, mark it as used at this
10431 point. (If it lookup found multiple functions the one selected
10432 later by overload resolution will be marked as used at that
10434 if (BASELINK_P (baselink))
10435 fns = BASELINK_FUNCTIONS (baselink);
10436 if (!template_id_p && !really_overloaded_fn (fns))
10437 mark_used (OVL_CURRENT (fns));
10439 /* Add back the template arguments, if present. */
10440 if (BASELINK_P (baselink) && template_id_p)
10441 BASELINK_FUNCTIONS (baselink)
10442 = build_nt (TEMPLATE_ID_EXPR,
10443 BASELINK_FUNCTIONS (baselink),
10445 /* Update the conversion operator type. */
10446 BASELINK_OPTYPE (baselink) = optype;
10449 object_type = current_class_type;
10450 return adjust_result_of_qualified_name_lookup (baselink,
10455 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
10456 true if the qualified-id will be a postfix-expression in-and-of
10457 itself; false if more of the postfix-expression follows the
10458 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
10462 tsubst_qualified_id (tree qualified_id, tree args,
10463 tsubst_flags_t complain, tree in_decl,
10464 bool done, bool address_p)
10470 tree template_args;
10472 gcc_assert (TREE_CODE (qualified_id) == SCOPE_REF);
10474 /* Figure out what name to look up. */
10475 name = TREE_OPERAND (qualified_id, 1);
10476 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
10478 is_template = true;
10479 template_args = TREE_OPERAND (name, 1);
10481 template_args = tsubst_template_args (template_args, args,
10482 complain, in_decl);
10483 name = TREE_OPERAND (name, 0);
10487 is_template = false;
10488 template_args = NULL_TREE;
10491 /* Substitute into the qualifying scope. When there are no ARGS, we
10492 are just trying to simplify a non-dependent expression. In that
10493 case the qualifying scope may be dependent, and, in any case,
10494 substituting will not help. */
10495 scope = TREE_OPERAND (qualified_id, 0);
10498 scope = tsubst (scope, args, complain, in_decl);
10499 expr = tsubst_copy (name, args, complain, in_decl);
10504 if (dependent_type_p (scope))
10506 tree type = NULL_TREE;
10507 if (DECL_P (expr) && !dependent_scope_p (scope))
10508 type = TREE_TYPE (expr);
10509 return build_qualified_name (type, scope, expr,
10510 QUALIFIED_NAME_IS_TEMPLATE (qualified_id));
10513 if (!BASELINK_P (name) && !DECL_P (expr))
10515 if (TREE_CODE (expr) == BIT_NOT_EXPR)
10517 /* A BIT_NOT_EXPR is used to represent a destructor. */
10518 if (!check_dtor_name (scope, TREE_OPERAND (expr, 0)))
10520 error ("qualifying type %qT does not match destructor name ~%qT",
10521 scope, TREE_OPERAND (expr, 0));
10522 expr = error_mark_node;
10525 expr = lookup_qualified_name (scope, complete_dtor_identifier,
10526 /*is_type_p=*/0, false);
10529 expr = lookup_qualified_name (scope, expr, /*is_type_p=*/0, false);
10530 if (TREE_CODE (TREE_CODE (expr) == TEMPLATE_DECL
10531 ? DECL_TEMPLATE_RESULT (expr) : expr) == TYPE_DECL)
10533 if (complain & tf_error)
10535 error ("dependent-name %qE is parsed as a non-type, but "
10536 "instantiation yields a type", qualified_id);
10537 inform (input_location, "say %<typename %E%> if a type is meant", qualified_id);
10539 return error_mark_node;
10545 check_accessibility_of_qualified_id (expr, /*object_type=*/NULL_TREE,
10547 /* Remember that there was a reference to this entity. */
10551 if (expr == error_mark_node || TREE_CODE (expr) == TREE_LIST)
10553 if (complain & tf_error)
10554 qualified_name_lookup_error (scope,
10555 TREE_OPERAND (qualified_id, 1),
10556 expr, input_location);
10557 return error_mark_node;
10561 expr = lookup_template_function (expr, template_args);
10563 if (expr == error_mark_node && complain & tf_error)
10564 qualified_name_lookup_error (scope, TREE_OPERAND (qualified_id, 1),
10565 expr, input_location);
10566 else if (TYPE_P (scope))
10568 expr = (adjust_result_of_qualified_name_lookup
10569 (expr, scope, current_class_type));
10570 expr = (finish_qualified_id_expr
10571 (scope, expr, done, address_p,
10572 QUALIFIED_NAME_IS_TEMPLATE (qualified_id),
10573 /*template_arg_p=*/false));
10576 /* Expressions do not generally have reference type. */
10577 if (TREE_CODE (expr) != SCOPE_REF
10578 /* However, if we're about to form a pointer-to-member, we just
10579 want the referenced member referenced. */
10580 && TREE_CODE (expr) != OFFSET_REF)
10581 expr = convert_from_reference (expr);
10586 /* Like tsubst, but deals with expressions. This function just replaces
10587 template parms; to finish processing the resultant expression, use
10591 tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl)
10593 enum tree_code code;
10596 if (t == NULL_TREE || t == error_mark_node || args == NULL_TREE)
10599 code = TREE_CODE (t);
10604 r = retrieve_local_specialization (t);
10609 /* This can happen for a parameter name used later in a function
10610 declaration (such as in a late-specified return type). Just
10611 make a dummy decl, since it's only used for its type. */
10612 gcc_assert (cp_unevaluated_operand != 0);
10613 /* We copy T because want to tsubst the PARM_DECL only,
10614 not the following PARM_DECLs that are chained to T. */
10616 r = tsubst_decl (c, args, complain);
10617 /* Give it the template pattern as its context; its true context
10618 hasn't been instantiated yet and this is good enough for
10620 DECL_CONTEXT (r) = DECL_CONTEXT (t);
10623 if (TREE_CODE (r) == ARGUMENT_PACK_SELECT)
10624 r = ARGUMENT_PACK_SELECT_ARG (r);
10633 if (DECL_TEMPLATE_PARM_P (t))
10634 return tsubst_copy (DECL_INITIAL (t), args, complain, in_decl);
10635 /* There is no need to substitute into namespace-scope
10637 if (DECL_NAMESPACE_SCOPE_P (t))
10639 /* If ARGS is NULL, then T is known to be non-dependent. */
10640 if (args == NULL_TREE)
10641 return integral_constant_value (t);
10643 /* Unfortunately, we cannot just call lookup_name here.
10646 template <int I> int f() {
10648 struct S { void g() { E e = a; } };
10651 When we instantiate f<7>::S::g(), say, lookup_name is not
10652 clever enough to find f<7>::a. */
10654 = tsubst_aggr_type (TREE_TYPE (t), args, complain, in_decl,
10655 /*entering_scope=*/0);
10657 for (v = TYPE_VALUES (enum_type);
10659 v = TREE_CHAIN (v))
10660 if (TREE_PURPOSE (v) == DECL_NAME (t))
10661 return TREE_VALUE (v);
10663 /* We didn't find the name. That should never happen; if
10664 name-lookup found it during preliminary parsing, we
10665 should find it again here during instantiation. */
10666 gcc_unreachable ();
10671 if (DECL_CONTEXT (t))
10675 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args, complain, in_decl,
10676 /*entering_scope=*/1);
10677 if (ctx != DECL_CONTEXT (t))
10679 tree r = lookup_field (ctx, DECL_NAME (t), 0, false);
10682 if (complain & tf_error)
10683 error ("using invalid field %qD", t);
10684 return error_mark_node;
10693 case FUNCTION_DECL:
10694 if ((DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t))
10695 || local_variable_p (t))
10696 t = tsubst (t, args, complain, in_decl);
10701 return tsubst_baselink (t, current_class_type, args, complain, in_decl);
10703 case TEMPLATE_DECL:
10704 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
10705 return tsubst (TREE_TYPE (DECL_TEMPLATE_RESULT (t)),
10706 args, complain, in_decl);
10707 else if (DECL_FUNCTION_TEMPLATE_P (t) && DECL_MEMBER_TEMPLATE_P (t))
10708 return tsubst (t, args, complain, in_decl);
10709 else if (DECL_CLASS_SCOPE_P (t)
10710 && uses_template_parms (DECL_CONTEXT (t)))
10712 /* Template template argument like the following example need
10715 template <template <class> class TT> struct C {};
10716 template <class T> struct D {
10717 template <class U> struct E {};
10722 We are processing the template argument `E' in #1 for
10723 the template instantiation #2. Originally, `E' is a
10724 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
10725 have to substitute this with one having context `D<int>'. */
10727 tree context = tsubst (DECL_CONTEXT (t), args, complain, in_decl);
10728 return lookup_field (context, DECL_NAME(t), 0, false);
10731 /* Ordinary template template argument. */
10735 case REINTERPRET_CAST_EXPR:
10736 case CONST_CAST_EXPR:
10737 case STATIC_CAST_EXPR:
10738 case DYNAMIC_CAST_EXPR:
10741 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
10742 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
10745 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
10747 /* We only want to compute the number of arguments. */
10748 tree expanded = tsubst_pack_expansion (TREE_OPERAND (t, 0), args,
10749 complain, in_decl);
10752 if (TREE_CODE (expanded) == TREE_VEC)
10753 len = TREE_VEC_LENGTH (expanded);
10755 if (expanded == error_mark_node)
10756 return error_mark_node;
10757 else if (PACK_EXPANSION_P (expanded)
10758 || (TREE_CODE (expanded) == TREE_VEC
10760 && PACK_EXPANSION_P (TREE_VEC_ELT (expanded, len-1))))
10762 if (TREE_CODE (expanded) == TREE_VEC)
10763 expanded = TREE_VEC_ELT (expanded, len - 1);
10765 if (TYPE_P (expanded))
10766 return cxx_sizeof_or_alignof_type (expanded, SIZEOF_EXPR,
10767 complain & tf_error);
10769 return cxx_sizeof_or_alignof_expr (expanded, SIZEOF_EXPR,
10770 complain & tf_error);
10773 return build_int_cst (size_type_node, len);
10779 case TRUTH_NOT_EXPR:
10782 case UNARY_PLUS_EXPR: /* Unary + */
10787 case REALPART_EXPR:
10788 case IMAGPART_EXPR:
10790 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
10791 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
10793 case COMPONENT_REF:
10798 object = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
10799 name = TREE_OPERAND (t, 1);
10800 if (TREE_CODE (name) == BIT_NOT_EXPR)
10802 name = tsubst_copy (TREE_OPERAND (name, 0), args,
10803 complain, in_decl);
10804 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
10806 else if (TREE_CODE (name) == SCOPE_REF
10807 && TREE_CODE (TREE_OPERAND (name, 1)) == BIT_NOT_EXPR)
10809 tree base = tsubst_copy (TREE_OPERAND (name, 0), args,
10810 complain, in_decl);
10811 name = TREE_OPERAND (name, 1);
10812 name = tsubst_copy (TREE_OPERAND (name, 0), args,
10813 complain, in_decl);
10814 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
10815 name = build_qualified_name (/*type=*/NULL_TREE,
10817 /*template_p=*/false);
10819 else if (TREE_CODE (name) == BASELINK)
10820 name = tsubst_baselink (name,
10821 non_reference (TREE_TYPE (object)),
10825 name = tsubst_copy (name, args, complain, in_decl);
10826 return build_nt (COMPONENT_REF, object, name, NULL_TREE);
10832 case TRUNC_DIV_EXPR:
10833 case CEIL_DIV_EXPR:
10834 case FLOOR_DIV_EXPR:
10835 case ROUND_DIV_EXPR:
10836 case EXACT_DIV_EXPR:
10840 case TRUNC_MOD_EXPR:
10841 case FLOOR_MOD_EXPR:
10842 case TRUTH_ANDIF_EXPR:
10843 case TRUTH_ORIF_EXPR:
10844 case TRUTH_AND_EXPR:
10845 case TRUTH_OR_EXPR:
10858 case COMPOUND_EXPR:
10861 case PREDECREMENT_EXPR:
10862 case PREINCREMENT_EXPR:
10863 case POSTDECREMENT_EXPR:
10864 case POSTINCREMENT_EXPR:
10866 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
10867 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
10870 return build_qualified_name (/*type=*/NULL_TREE,
10871 tsubst_copy (TREE_OPERAND (t, 0),
10872 args, complain, in_decl),
10873 tsubst_copy (TREE_OPERAND (t, 1),
10874 args, complain, in_decl),
10875 QUALIFIED_NAME_IS_TEMPLATE (t));
10880 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
10881 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
10882 NULL_TREE, NULL_TREE);
10886 int n = VL_EXP_OPERAND_LENGTH (t);
10887 tree result = build_vl_exp (CALL_EXPR, n);
10889 for (i = 0; i < n; i++)
10890 TREE_OPERAND (t, i) = tsubst_copy (TREE_OPERAND (t, i), args,
10891 complain, in_decl);
10897 case PSEUDO_DTOR_EXPR:
10900 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
10901 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
10902 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
10903 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
10910 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
10911 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
10912 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
10913 NEW_EXPR_USE_GLOBAL (r) = NEW_EXPR_USE_GLOBAL (t);
10920 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
10921 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
10922 DELETE_EXPR_USE_GLOBAL (r) = DELETE_EXPR_USE_GLOBAL (t);
10923 DELETE_EXPR_USE_VEC (r) = DELETE_EXPR_USE_VEC (t);
10927 case TEMPLATE_ID_EXPR:
10929 /* Substituted template arguments */
10930 tree fn = TREE_OPERAND (t, 0);
10931 tree targs = TREE_OPERAND (t, 1);
10933 fn = tsubst_copy (fn, args, complain, in_decl);
10935 targs = tsubst_template_args (targs, args, complain, in_decl);
10937 return lookup_template_function (fn, targs);
10942 tree purpose, value, chain;
10944 if (t == void_list_node)
10947 purpose = TREE_PURPOSE (t);
10949 purpose = tsubst_copy (purpose, args, complain, in_decl);
10950 value = TREE_VALUE (t);
10952 value = tsubst_copy (value, args, complain, in_decl);
10953 chain = TREE_CHAIN (t);
10954 if (chain && chain != void_type_node)
10955 chain = tsubst_copy (chain, args, complain, in_decl);
10956 if (purpose == TREE_PURPOSE (t)
10957 && value == TREE_VALUE (t)
10958 && chain == TREE_CHAIN (t))
10960 return tree_cons (purpose, value, chain);
10965 case ENUMERAL_TYPE:
10967 case TEMPLATE_TYPE_PARM:
10968 case TEMPLATE_TEMPLATE_PARM:
10969 case BOUND_TEMPLATE_TEMPLATE_PARM:
10970 case TEMPLATE_PARM_INDEX:
10972 case REFERENCE_TYPE:
10974 case FUNCTION_TYPE:
10977 case TYPENAME_TYPE:
10978 case UNBOUND_CLASS_TEMPLATE:
10980 case DECLTYPE_TYPE:
10982 return tsubst (t, args, complain, in_decl);
10984 case IDENTIFIER_NODE:
10985 if (IDENTIFIER_TYPENAME_P (t))
10987 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10988 return mangle_conv_op_name_for_type (new_type);
10994 /* This is handled by tsubst_copy_and_build. */
10995 gcc_unreachable ();
10998 return build_x_va_arg (tsubst_copy (TREE_OPERAND (t, 0), args, complain,
11000 tsubst (TREE_TYPE (t), args, complain, in_decl));
11002 case CLEANUP_POINT_EXPR:
11003 /* We shouldn't have built any of these during initial template
11004 generation. Instead, they should be built during instantiation
11005 in response to the saved STMT_IS_FULL_EXPR_P setting. */
11006 gcc_unreachable ();
11009 mark_used (TREE_OPERAND (t, 1));
11012 case EXPR_PACK_EXPANSION:
11013 error ("invalid use of pack expansion expression");
11014 return error_mark_node;
11016 case NONTYPE_ARGUMENT_PACK:
11017 error ("use %<...%> to expand argument pack");
11018 return error_mark_node;
11025 /* Like tsubst_copy, but specifically for OpenMP clauses. */
11028 tsubst_omp_clauses (tree clauses, tree args, tsubst_flags_t complain,
11031 tree new_clauses = NULL, nc, oc;
11033 for (oc = clauses; oc ; oc = OMP_CLAUSE_CHAIN (oc))
11035 nc = copy_node (oc);
11036 OMP_CLAUSE_CHAIN (nc) = new_clauses;
11039 switch (OMP_CLAUSE_CODE (nc))
11041 case OMP_CLAUSE_LASTPRIVATE:
11042 if (OMP_CLAUSE_LASTPRIVATE_STMT (oc))
11044 OMP_CLAUSE_LASTPRIVATE_STMT (nc) = push_stmt_list ();
11045 tsubst_expr (OMP_CLAUSE_LASTPRIVATE_STMT (oc), args, complain,
11046 in_decl, /*integral_constant_expression_p=*/false);
11047 OMP_CLAUSE_LASTPRIVATE_STMT (nc)
11048 = pop_stmt_list (OMP_CLAUSE_LASTPRIVATE_STMT (nc));
11051 case OMP_CLAUSE_PRIVATE:
11052 case OMP_CLAUSE_SHARED:
11053 case OMP_CLAUSE_FIRSTPRIVATE:
11054 case OMP_CLAUSE_REDUCTION:
11055 case OMP_CLAUSE_COPYIN:
11056 case OMP_CLAUSE_COPYPRIVATE:
11057 case OMP_CLAUSE_IF:
11058 case OMP_CLAUSE_NUM_THREADS:
11059 case OMP_CLAUSE_SCHEDULE:
11060 case OMP_CLAUSE_COLLAPSE:
11061 OMP_CLAUSE_OPERAND (nc, 0)
11062 = tsubst_expr (OMP_CLAUSE_OPERAND (oc, 0), args, complain,
11063 in_decl, /*integral_constant_expression_p=*/false);
11065 case OMP_CLAUSE_NOWAIT:
11066 case OMP_CLAUSE_ORDERED:
11067 case OMP_CLAUSE_DEFAULT:
11068 case OMP_CLAUSE_UNTIED:
11071 gcc_unreachable ();
11075 return finish_omp_clauses (nreverse (new_clauses));
11078 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
11081 tsubst_copy_asm_operands (tree t, tree args, tsubst_flags_t complain,
11084 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
11086 tree purpose, value, chain;
11091 if (TREE_CODE (t) != TREE_LIST)
11092 return tsubst_copy_and_build (t, args, complain, in_decl,
11093 /*function_p=*/false,
11094 /*integral_constant_expression_p=*/false);
11096 if (t == void_list_node)
11099 purpose = TREE_PURPOSE (t);
11101 purpose = RECUR (purpose);
11102 value = TREE_VALUE (t);
11103 if (value && TREE_CODE (value) != LABEL_DECL)
11104 value = RECUR (value);
11105 chain = TREE_CHAIN (t);
11106 if (chain && chain != void_type_node)
11107 chain = RECUR (chain);
11108 return tree_cons (purpose, value, chain);
11112 /* Substitute one OMP_FOR iterator. */
11115 tsubst_omp_for_iterator (tree t, int i, tree declv, tree initv,
11116 tree condv, tree incrv, tree *clauses,
11117 tree args, tsubst_flags_t complain, tree in_decl,
11118 bool integral_constant_expression_p)
11120 #define RECUR(NODE) \
11121 tsubst_expr ((NODE), args, complain, in_decl, \
11122 integral_constant_expression_p)
11123 tree decl, init, cond, incr, auto_node;
11125 init = TREE_VEC_ELT (OMP_FOR_INIT (t), i);
11126 gcc_assert (TREE_CODE (init) == MODIFY_EXPR);
11127 decl = RECUR (TREE_OPERAND (init, 0));
11128 init = TREE_OPERAND (init, 1);
11129 auto_node = type_uses_auto (TREE_TYPE (decl));
11130 if (auto_node && init)
11132 tree init_expr = init;
11133 if (TREE_CODE (init_expr) == DECL_EXPR)
11134 init_expr = DECL_INITIAL (DECL_EXPR_DECL (init_expr));
11135 init_expr = RECUR (init_expr);
11137 = do_auto_deduction (TREE_TYPE (decl), init_expr, auto_node);
11139 gcc_assert (!type_dependent_expression_p (decl));
11141 if (!CLASS_TYPE_P (TREE_TYPE (decl)))
11143 cond = RECUR (TREE_VEC_ELT (OMP_FOR_COND (t), i));
11144 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
11145 if (TREE_CODE (incr) == MODIFY_EXPR)
11146 incr = build_x_modify_expr (RECUR (TREE_OPERAND (incr, 0)), NOP_EXPR,
11147 RECUR (TREE_OPERAND (incr, 1)),
11150 incr = RECUR (incr);
11151 TREE_VEC_ELT (declv, i) = decl;
11152 TREE_VEC_ELT (initv, i) = init;
11153 TREE_VEC_ELT (condv, i) = cond;
11154 TREE_VEC_ELT (incrv, i) = incr;
11158 if (init && TREE_CODE (init) != DECL_EXPR)
11161 for (c = *clauses; c ; c = OMP_CLAUSE_CHAIN (c))
11163 if ((OMP_CLAUSE_CODE (c) == OMP_CLAUSE_PRIVATE
11164 || OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LASTPRIVATE)
11165 && OMP_CLAUSE_DECL (c) == decl)
11167 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_FIRSTPRIVATE
11168 && OMP_CLAUSE_DECL (c) == decl)
11169 error ("iteration variable %qD should not be firstprivate", decl);
11170 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_REDUCTION
11171 && OMP_CLAUSE_DECL (c) == decl)
11172 error ("iteration variable %qD should not be reduction", decl);
11176 c = build_omp_clause (input_location, OMP_CLAUSE_PRIVATE);
11177 OMP_CLAUSE_DECL (c) = decl;
11178 c = finish_omp_clauses (c);
11181 OMP_CLAUSE_CHAIN (c) = *clauses;
11186 cond = TREE_VEC_ELT (OMP_FOR_COND (t), i);
11187 if (COMPARISON_CLASS_P (cond))
11188 cond = build2 (TREE_CODE (cond), boolean_type_node,
11189 RECUR (TREE_OPERAND (cond, 0)),
11190 RECUR (TREE_OPERAND (cond, 1)));
11192 cond = RECUR (cond);
11193 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
11194 switch (TREE_CODE (incr))
11196 case PREINCREMENT_EXPR:
11197 case PREDECREMENT_EXPR:
11198 case POSTINCREMENT_EXPR:
11199 case POSTDECREMENT_EXPR:
11200 incr = build2 (TREE_CODE (incr), TREE_TYPE (decl),
11201 RECUR (TREE_OPERAND (incr, 0)), NULL_TREE);
11204 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
11205 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
11207 tree rhs = TREE_OPERAND (incr, 1);
11208 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
11209 RECUR (TREE_OPERAND (incr, 0)),
11210 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
11211 RECUR (TREE_OPERAND (rhs, 0)),
11212 RECUR (TREE_OPERAND (rhs, 1))));
11215 incr = RECUR (incr);
11218 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
11219 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
11221 tree lhs = RECUR (TREE_OPERAND (incr, 0));
11222 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl), lhs,
11223 build2 (TREE_CODE (TREE_OPERAND (incr, 1)),
11224 TREE_TYPE (decl), lhs,
11225 RECUR (TREE_OPERAND (incr, 2))));
11227 else if (TREE_CODE (TREE_OPERAND (incr, 1)) == NOP_EXPR
11228 && (TREE_CODE (TREE_OPERAND (incr, 2)) == PLUS_EXPR
11229 || (TREE_CODE (TREE_OPERAND (incr, 2)) == MINUS_EXPR)))
11231 tree rhs = TREE_OPERAND (incr, 2);
11232 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
11233 RECUR (TREE_OPERAND (incr, 0)),
11234 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
11235 RECUR (TREE_OPERAND (rhs, 0)),
11236 RECUR (TREE_OPERAND (rhs, 1))));
11239 incr = RECUR (incr);
11242 incr = RECUR (incr);
11246 TREE_VEC_ELT (declv, i) = decl;
11247 TREE_VEC_ELT (initv, i) = init;
11248 TREE_VEC_ELT (condv, i) = cond;
11249 TREE_VEC_ELT (incrv, i) = incr;
11253 /* Like tsubst_copy for expressions, etc. but also does semantic
11257 tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl,
11258 bool integral_constant_expression_p)
11260 #define RECUR(NODE) \
11261 tsubst_expr ((NODE), args, complain, in_decl, \
11262 integral_constant_expression_p)
11266 if (t == NULL_TREE || t == error_mark_node)
11269 if (EXPR_HAS_LOCATION (t))
11270 input_location = EXPR_LOCATION (t);
11271 if (STATEMENT_CODE_P (TREE_CODE (t)))
11272 current_stmt_tree ()->stmts_are_full_exprs_p = STMT_IS_FULL_EXPR_P (t);
11274 switch (TREE_CODE (t))
11276 case STATEMENT_LIST:
11278 tree_stmt_iterator i;
11279 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
11280 RECUR (tsi_stmt (i));
11284 case CTOR_INITIALIZER:
11285 finish_mem_initializers (tsubst_initializer_list
11286 (TREE_OPERAND (t, 0), args));
11290 finish_return_stmt (RECUR (TREE_OPERAND (t, 0)));
11294 tmp = RECUR (EXPR_STMT_EXPR (t));
11295 if (EXPR_STMT_STMT_EXPR_RESULT (t))
11296 finish_stmt_expr_expr (tmp, cur_stmt_expr);
11298 finish_expr_stmt (tmp);
11302 do_using_directive (RECUR (USING_STMT_NAMESPACE (t)));
11310 decl = DECL_EXPR_DECL (t);
11311 if (TREE_CODE (decl) == LABEL_DECL)
11312 finish_label_decl (DECL_NAME (decl));
11313 else if (TREE_CODE (decl) == USING_DECL)
11315 tree scope = USING_DECL_SCOPE (decl);
11316 tree name = DECL_NAME (decl);
11319 scope = RECUR (scope);
11320 decl = lookup_qualified_name (scope, name,
11321 /*is_type_p=*/false,
11322 /*complain=*/false);
11323 if (decl == error_mark_node || TREE_CODE (decl) == TREE_LIST)
11324 qualified_name_lookup_error (scope, name, decl, input_location);
11326 do_local_using_decl (decl, scope, name);
11330 init = DECL_INITIAL (decl);
11331 decl = tsubst (decl, args, complain, in_decl);
11332 if (decl != error_mark_node)
11334 /* By marking the declaration as instantiated, we avoid
11335 trying to instantiate it. Since instantiate_decl can't
11336 handle local variables, and since we've already done
11337 all that needs to be done, that's the right thing to
11339 if (TREE_CODE (decl) == VAR_DECL)
11340 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
11341 if (TREE_CODE (decl) == VAR_DECL
11342 && ANON_AGGR_TYPE_P (TREE_TYPE (decl)))
11343 /* Anonymous aggregates are a special case. */
11344 finish_anon_union (decl);
11347 maybe_push_decl (decl);
11348 if (TREE_CODE (decl) == VAR_DECL
11349 && DECL_PRETTY_FUNCTION_P (decl))
11351 /* For __PRETTY_FUNCTION__ we have to adjust the
11353 const char *const name
11354 = cxx_printable_name (current_function_decl, 2);
11355 init = cp_fname_init (name, &TREE_TYPE (decl));
11359 tree t = RECUR (init);
11362 /* If we had an initializer but it
11363 instantiated to nothing,
11364 value-initialize the object. This will
11365 only occur when the initializer was a
11366 pack expansion where the parameter packs
11367 used in that expansion were of length
11369 init = build_value_init (TREE_TYPE (decl));
11374 cp_finish_decl (decl, init, false, NULL_TREE, 0);
11379 /* A DECL_EXPR can also be used as an expression, in the condition
11380 clause of an if/for/while construct. */
11385 stmt = begin_for_stmt ();
11386 RECUR (FOR_INIT_STMT (t));
11387 finish_for_init_stmt (stmt);
11388 tmp = RECUR (FOR_COND (t));
11389 finish_for_cond (tmp, stmt);
11390 tmp = RECUR (FOR_EXPR (t));
11391 finish_for_expr (tmp, stmt);
11392 RECUR (FOR_BODY (t));
11393 finish_for_stmt (stmt);
11397 stmt = begin_while_stmt ();
11398 tmp = RECUR (WHILE_COND (t));
11399 finish_while_stmt_cond (tmp, stmt);
11400 RECUR (WHILE_BODY (t));
11401 finish_while_stmt (stmt);
11405 stmt = begin_do_stmt ();
11406 RECUR (DO_BODY (t));
11407 finish_do_body (stmt);
11408 tmp = RECUR (DO_COND (t));
11409 finish_do_stmt (tmp, stmt);
11413 stmt = begin_if_stmt ();
11414 tmp = RECUR (IF_COND (t));
11415 finish_if_stmt_cond (tmp, stmt);
11416 RECUR (THEN_CLAUSE (t));
11417 finish_then_clause (stmt);
11419 if (ELSE_CLAUSE (t))
11421 begin_else_clause (stmt);
11422 RECUR (ELSE_CLAUSE (t));
11423 finish_else_clause (stmt);
11426 finish_if_stmt (stmt);
11430 if (BIND_EXPR_BODY_BLOCK (t))
11431 stmt = begin_function_body ();
11433 stmt = begin_compound_stmt (BIND_EXPR_TRY_BLOCK (t)
11434 ? BCS_TRY_BLOCK : 0);
11436 RECUR (BIND_EXPR_BODY (t));
11438 if (BIND_EXPR_BODY_BLOCK (t))
11439 finish_function_body (stmt);
11441 finish_compound_stmt (stmt);
11445 finish_break_stmt ();
11448 case CONTINUE_STMT:
11449 finish_continue_stmt ();
11453 stmt = begin_switch_stmt ();
11454 tmp = RECUR (SWITCH_STMT_COND (t));
11455 finish_switch_cond (tmp, stmt);
11456 RECUR (SWITCH_STMT_BODY (t));
11457 finish_switch_stmt (stmt);
11460 case CASE_LABEL_EXPR:
11461 finish_case_label (EXPR_LOCATION (t),
11462 RECUR (CASE_LOW (t)),
11463 RECUR (CASE_HIGH (t)));
11468 tree decl = LABEL_EXPR_LABEL (t);
11471 label = finish_label_stmt (DECL_NAME (decl));
11472 if (DECL_ATTRIBUTES (decl) != NULL_TREE)
11473 cplus_decl_attributes (&label, DECL_ATTRIBUTES (decl), 0);
11478 tmp = GOTO_DESTINATION (t);
11479 if (TREE_CODE (tmp) != LABEL_DECL)
11480 /* Computed goto's must be tsubst'd into. On the other hand,
11481 non-computed gotos must not be; the identifier in question
11482 will have no binding. */
11485 tmp = DECL_NAME (tmp);
11486 finish_goto_stmt (tmp);
11490 tmp = finish_asm_stmt
11491 (ASM_VOLATILE_P (t),
11492 RECUR (ASM_STRING (t)),
11493 tsubst_copy_asm_operands (ASM_OUTPUTS (t), args, complain, in_decl),
11494 tsubst_copy_asm_operands (ASM_INPUTS (t), args, complain, in_decl),
11495 tsubst_copy_asm_operands (ASM_CLOBBERS (t), args, complain, in_decl),
11496 tsubst_copy_asm_operands (ASM_LABELS (t), args, complain, in_decl));
11498 tree asm_expr = tmp;
11499 if (TREE_CODE (asm_expr) == CLEANUP_POINT_EXPR)
11500 asm_expr = TREE_OPERAND (asm_expr, 0);
11501 ASM_INPUT_P (asm_expr) = ASM_INPUT_P (t);
11508 stmt = begin_try_block ();
11509 RECUR (TRY_STMTS (t));
11510 finish_cleanup_try_block (stmt);
11511 finish_cleanup (RECUR (TRY_HANDLERS (t)), stmt);
11515 tree compound_stmt = NULL_TREE;
11517 if (FN_TRY_BLOCK_P (t))
11518 stmt = begin_function_try_block (&compound_stmt);
11520 stmt = begin_try_block ();
11522 RECUR (TRY_STMTS (t));
11524 if (FN_TRY_BLOCK_P (t))
11525 finish_function_try_block (stmt);
11527 finish_try_block (stmt);
11529 RECUR (TRY_HANDLERS (t));
11530 if (FN_TRY_BLOCK_P (t))
11531 finish_function_handler_sequence (stmt, compound_stmt);
11533 finish_handler_sequence (stmt);
11539 tree decl = HANDLER_PARMS (t);
11543 decl = tsubst (decl, args, complain, in_decl);
11544 /* Prevent instantiate_decl from trying to instantiate
11545 this variable. We've already done all that needs to be
11547 if (decl != error_mark_node)
11548 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
11550 stmt = begin_handler ();
11551 finish_handler_parms (decl, stmt);
11552 RECUR (HANDLER_BODY (t));
11553 finish_handler (stmt);
11558 tsubst (TREE_TYPE (t), args, complain, NULL_TREE);
11561 case STATIC_ASSERT:
11564 tsubst_expr (STATIC_ASSERT_CONDITION (t),
11567 /*integral_constant_expression_p=*/true);
11568 finish_static_assert (condition,
11569 STATIC_ASSERT_MESSAGE (t),
11570 STATIC_ASSERT_SOURCE_LOCATION (t),
11571 /*member_p=*/false);
11576 tmp = tsubst_omp_clauses (OMP_PARALLEL_CLAUSES (t),
11577 args, complain, in_decl);
11578 stmt = begin_omp_parallel ();
11579 RECUR (OMP_PARALLEL_BODY (t));
11580 OMP_PARALLEL_COMBINED (finish_omp_parallel (tmp, stmt))
11581 = OMP_PARALLEL_COMBINED (t);
11585 tmp = tsubst_omp_clauses (OMP_TASK_CLAUSES (t),
11586 args, complain, in_decl);
11587 stmt = begin_omp_task ();
11588 RECUR (OMP_TASK_BODY (t));
11589 finish_omp_task (tmp, stmt);
11594 tree clauses, body, pre_body;
11595 tree declv, initv, condv, incrv;
11598 clauses = tsubst_omp_clauses (OMP_FOR_CLAUSES (t),
11599 args, complain, in_decl);
11600 declv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
11601 initv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
11602 condv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
11603 incrv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
11605 for (i = 0; i < TREE_VEC_LENGTH (OMP_FOR_INIT (t)); i++)
11606 tsubst_omp_for_iterator (t, i, declv, initv, condv, incrv,
11607 &clauses, args, complain, in_decl,
11608 integral_constant_expression_p);
11610 stmt = begin_omp_structured_block ();
11612 for (i = 0; i < TREE_VEC_LENGTH (initv); i++)
11613 if (TREE_VEC_ELT (initv, i) == NULL
11614 || TREE_CODE (TREE_VEC_ELT (initv, i)) != DECL_EXPR)
11615 TREE_VEC_ELT (initv, i) = RECUR (TREE_VEC_ELT (initv, i));
11616 else if (CLASS_TYPE_P (TREE_TYPE (TREE_VEC_ELT (initv, i))))
11618 tree init = RECUR (TREE_VEC_ELT (initv, i));
11619 gcc_assert (init == TREE_VEC_ELT (declv, i));
11620 TREE_VEC_ELT (initv, i) = NULL_TREE;
11624 tree decl_expr = TREE_VEC_ELT (initv, i);
11625 tree init = DECL_INITIAL (DECL_EXPR_DECL (decl_expr));
11626 gcc_assert (init != NULL);
11627 TREE_VEC_ELT (initv, i) = RECUR (init);
11628 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = NULL;
11630 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = init;
11633 pre_body = push_stmt_list ();
11634 RECUR (OMP_FOR_PRE_BODY (t));
11635 pre_body = pop_stmt_list (pre_body);
11637 body = push_stmt_list ();
11638 RECUR (OMP_FOR_BODY (t));
11639 body = pop_stmt_list (body);
11641 t = finish_omp_for (EXPR_LOCATION (t), declv, initv, condv, incrv,
11642 body, pre_body, clauses);
11644 add_stmt (finish_omp_structured_block (stmt));
11650 tmp = tsubst_omp_clauses (OMP_CLAUSES (t), args, complain, in_decl);
11651 stmt = push_stmt_list ();
11652 RECUR (OMP_BODY (t));
11653 stmt = pop_stmt_list (stmt);
11656 OMP_BODY (t) = stmt;
11657 OMP_CLAUSES (t) = tmp;
11665 stmt = push_stmt_list ();
11666 RECUR (OMP_BODY (t));
11667 stmt = pop_stmt_list (stmt);
11670 OMP_BODY (t) = stmt;
11675 gcc_assert (OMP_ATOMIC_DEPENDENT_P (t));
11677 tree op1 = TREE_OPERAND (t, 1);
11678 tree lhs = RECUR (TREE_OPERAND (op1, 0));
11679 tree rhs = RECUR (TREE_OPERAND (op1, 1));
11680 finish_omp_atomic (TREE_CODE (op1), lhs, rhs);
11684 case EXPR_PACK_EXPANSION:
11685 error ("invalid use of pack expansion expression");
11686 return error_mark_node;
11688 case NONTYPE_ARGUMENT_PACK:
11689 error ("use %<...%> to expand argument pack");
11690 return error_mark_node;
11693 gcc_assert (!STATEMENT_CODE_P (TREE_CODE (t)));
11695 return tsubst_copy_and_build (t, args, complain, in_decl,
11696 /*function_p=*/false,
11697 integral_constant_expression_p);
11704 /* T is a postfix-expression that is not being used in a function
11705 call. Return the substituted version of T. */
11708 tsubst_non_call_postfix_expression (tree t, tree args,
11709 tsubst_flags_t complain,
11712 if (TREE_CODE (t) == SCOPE_REF)
11713 t = tsubst_qualified_id (t, args, complain, in_decl,
11714 /*done=*/false, /*address_p=*/false);
11716 t = tsubst_copy_and_build (t, args, complain, in_decl,
11717 /*function_p=*/false,
11718 /*integral_constant_expression_p=*/false);
11723 /* Like tsubst but deals with expressions and performs semantic
11724 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
11727 tsubst_copy_and_build (tree t,
11729 tsubst_flags_t complain,
11732 bool integral_constant_expression_p)
11734 #define RECUR(NODE) \
11735 tsubst_copy_and_build (NODE, args, complain, in_decl, \
11736 /*function_p=*/false, \
11737 integral_constant_expression_p)
11741 if (t == NULL_TREE || t == error_mark_node)
11744 switch (TREE_CODE (t))
11748 /* Fall through. */
11749 case IDENTIFIER_NODE:
11753 bool non_integral_constant_expression_p;
11754 const char *error_msg;
11756 if (IDENTIFIER_TYPENAME_P (t))
11758 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
11759 t = mangle_conv_op_name_for_type (new_type);
11762 /* Look up the name. */
11763 decl = lookup_name (t);
11765 /* By convention, expressions use ERROR_MARK_NODE to indicate
11766 failure, not NULL_TREE. */
11767 if (decl == NULL_TREE)
11768 decl = error_mark_node;
11770 decl = finish_id_expression (t, decl, NULL_TREE,
11772 integral_constant_expression_p,
11773 /*allow_non_integral_constant_expression_p=*/false,
11774 &non_integral_constant_expression_p,
11775 /*template_p=*/false,
11777 /*address_p=*/false,
11778 /*template_arg_p=*/false,
11783 if (!function_p && TREE_CODE (decl) == IDENTIFIER_NODE)
11784 decl = unqualified_name_lookup_error (decl);
11788 case TEMPLATE_ID_EXPR:
11791 tree templ = RECUR (TREE_OPERAND (t, 0));
11792 tree targs = TREE_OPERAND (t, 1);
11795 targs = tsubst_template_args (targs, args, complain, in_decl);
11797 if (TREE_CODE (templ) == COMPONENT_REF)
11799 object = TREE_OPERAND (templ, 0);
11800 templ = TREE_OPERAND (templ, 1);
11803 object = NULL_TREE;
11804 templ = lookup_template_function (templ, targs);
11807 return build3 (COMPONENT_REF, TREE_TYPE (templ),
11808 object, templ, NULL_TREE);
11810 return baselink_for_fns (templ);
11815 tree r = RECUR (TREE_OPERAND (t, 0));
11817 if (REFERENCE_REF_P (t))
11819 /* A type conversion to reference type will be enclosed in
11820 such an indirect ref, but the substitution of the cast
11821 will have also added such an indirect ref. */
11822 if (TREE_CODE (TREE_TYPE (r)) == REFERENCE_TYPE)
11823 r = convert_from_reference (r);
11826 r = build_x_indirect_ref (r, "unary *", complain);
11832 (tsubst (TREE_TYPE (t), args, complain, in_decl),
11833 RECUR (TREE_OPERAND (t, 0)));
11836 case REINTERPRET_CAST_EXPR:
11837 case CONST_CAST_EXPR:
11838 case DYNAMIC_CAST_EXPR:
11839 case STATIC_CAST_EXPR:
11844 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
11845 if (integral_constant_expression_p
11846 && !cast_valid_in_integral_constant_expression_p (type))
11848 if (complain & tf_error)
11849 error ("a cast to a type other than an integral or "
11850 "enumeration type cannot appear in a constant-expression");
11851 return error_mark_node;
11854 op = RECUR (TREE_OPERAND (t, 0));
11856 switch (TREE_CODE (t))
11859 return build_functional_cast (type, op, complain);
11860 case REINTERPRET_CAST_EXPR:
11861 return build_reinterpret_cast (type, op, complain);
11862 case CONST_CAST_EXPR:
11863 return build_const_cast (type, op, complain);
11864 case DYNAMIC_CAST_EXPR:
11865 return build_dynamic_cast (type, op, complain);
11866 case STATIC_CAST_EXPR:
11867 return build_static_cast (type, op, complain);
11869 gcc_unreachable ();
11873 case POSTDECREMENT_EXPR:
11874 case POSTINCREMENT_EXPR:
11875 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
11876 args, complain, in_decl);
11877 return build_x_unary_op (TREE_CODE (t), op1, complain);
11879 case PREDECREMENT_EXPR:
11880 case PREINCREMENT_EXPR:
11884 case TRUTH_NOT_EXPR:
11885 case UNARY_PLUS_EXPR: /* Unary + */
11886 case REALPART_EXPR:
11887 case IMAGPART_EXPR:
11888 return build_x_unary_op (TREE_CODE (t), RECUR (TREE_OPERAND (t, 0)),
11892 op1 = TREE_OPERAND (t, 0);
11893 if (TREE_CODE (op1) == SCOPE_REF)
11894 op1 = tsubst_qualified_id (op1, args, complain, in_decl,
11895 /*done=*/true, /*address_p=*/true);
11897 op1 = tsubst_non_call_postfix_expression (op1, args, complain,
11899 if (TREE_CODE (op1) == LABEL_DECL)
11900 return finish_label_address_expr (DECL_NAME (op1),
11901 EXPR_LOCATION (op1));
11902 return build_x_unary_op (ADDR_EXPR, op1, complain);
11907 case TRUNC_DIV_EXPR:
11908 case CEIL_DIV_EXPR:
11909 case FLOOR_DIV_EXPR:
11910 case ROUND_DIV_EXPR:
11911 case EXACT_DIV_EXPR:
11915 case TRUNC_MOD_EXPR:
11916 case FLOOR_MOD_EXPR:
11917 case TRUTH_ANDIF_EXPR:
11918 case TRUTH_ORIF_EXPR:
11919 case TRUTH_AND_EXPR:
11920 case TRUTH_OR_EXPR:
11935 return build_x_binary_op
11937 RECUR (TREE_OPERAND (t, 0)),
11938 (TREE_NO_WARNING (TREE_OPERAND (t, 0))
11940 : TREE_CODE (TREE_OPERAND (t, 0))),
11941 RECUR (TREE_OPERAND (t, 1)),
11942 (TREE_NO_WARNING (TREE_OPERAND (t, 1))
11944 : TREE_CODE (TREE_OPERAND (t, 1))),
11945 /*overloaded_p=*/NULL,
11949 return tsubst_qualified_id (t, args, complain, in_decl, /*done=*/true,
11950 /*address_p=*/false);
11952 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
11953 args, complain, in_decl);
11954 return build_x_array_ref (op1, RECUR (TREE_OPERAND (t, 1)), complain);
11957 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
11958 return tsubst_copy (t, args, complain, in_decl);
11962 op1 = TREE_OPERAND (t, 0);
11965 /* When there are no ARGS, we are trying to evaluate a
11966 non-dependent expression from the parser. Trying to do
11967 the substitutions may not work. */
11969 op1 = TREE_TYPE (op1);
11973 ++cp_unevaluated_operand;
11974 ++c_inhibit_evaluation_warnings;
11975 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
11976 /*function_p=*/false,
11977 /*integral_constant_expression_p=*/false);
11978 --cp_unevaluated_operand;
11979 --c_inhibit_evaluation_warnings;
11982 return cxx_sizeof_or_alignof_type (op1, TREE_CODE (t),
11983 complain & tf_error);
11985 return cxx_sizeof_or_alignof_expr (op1, TREE_CODE (t),
11986 complain & tf_error);
11990 tree r = build_x_modify_expr
11991 (RECUR (TREE_OPERAND (t, 0)),
11992 TREE_CODE (TREE_OPERAND (t, 1)),
11993 RECUR (TREE_OPERAND (t, 2)),
11995 /* TREE_NO_WARNING must be set if either the expression was
11996 parenthesized or it uses an operator such as >>= rather
11997 than plain assignment. In the former case, it was already
11998 set and must be copied. In the latter case,
11999 build_x_modify_expr sets it and it must not be reset
12001 if (TREE_NO_WARNING (t))
12002 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
12007 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
12008 args, complain, in_decl);
12009 /* Remember that there was a reference to this entity. */
12012 return build_x_arrow (op1);
12016 tree placement = RECUR (TREE_OPERAND (t, 0));
12017 tree init = RECUR (TREE_OPERAND (t, 3));
12018 VEC(tree,gc) *placement_vec;
12019 VEC(tree,gc) *init_vec;
12022 if (placement == NULL_TREE)
12023 placement_vec = NULL;
12026 placement_vec = make_tree_vector ();
12027 for (; placement != NULL_TREE; placement = TREE_CHAIN (placement))
12028 VEC_safe_push (tree, gc, placement_vec, TREE_VALUE (placement));
12031 /* If there was an initializer in the original tree, but it
12032 instantiated to an empty list, then we should pass a
12033 non-NULL empty vector to tell build_new that it was an
12034 empty initializer() rather than no initializer. This can
12035 only happen when the initializer is a pack expansion whose
12036 parameter packs are of length zero. */
12037 if (init == NULL_TREE && TREE_OPERAND (t, 3) == NULL_TREE)
12041 init_vec = make_tree_vector ();
12042 if (init == void_zero_node)
12043 gcc_assert (init_vec != NULL);
12046 for (; init != NULL_TREE; init = TREE_CHAIN (init))
12047 VEC_safe_push (tree, gc, init_vec, TREE_VALUE (init));
12051 ret = build_new (&placement_vec,
12052 RECUR (TREE_OPERAND (t, 1)),
12053 RECUR (TREE_OPERAND (t, 2)),
12055 NEW_EXPR_USE_GLOBAL (t),
12058 if (placement_vec != NULL)
12059 release_tree_vector (placement_vec);
12060 if (init_vec != NULL)
12061 release_tree_vector (init_vec);
12067 return delete_sanity
12068 (RECUR (TREE_OPERAND (t, 0)),
12069 RECUR (TREE_OPERAND (t, 1)),
12070 DELETE_EXPR_USE_VEC (t),
12071 DELETE_EXPR_USE_GLOBAL (t));
12073 case COMPOUND_EXPR:
12074 return build_x_compound_expr (RECUR (TREE_OPERAND (t, 0)),
12075 RECUR (TREE_OPERAND (t, 1)),
12081 VEC(tree,gc) *call_args;
12082 unsigned int nargs, i;
12087 function = CALL_EXPR_FN (t);
12088 /* When we parsed the expression, we determined whether or
12089 not Koenig lookup should be performed. */
12090 koenig_p = KOENIG_LOOKUP_P (t);
12091 if (TREE_CODE (function) == SCOPE_REF)
12093 qualified_p = true;
12094 function = tsubst_qualified_id (function, args, complain, in_decl,
12096 /*address_p=*/false);
12100 if (TREE_CODE (function) == COMPONENT_REF)
12102 tree op = TREE_OPERAND (function, 1);
12104 qualified_p = (TREE_CODE (op) == SCOPE_REF
12105 || (BASELINK_P (op)
12106 && BASELINK_QUALIFIED_P (op)));
12109 qualified_p = false;
12111 function = tsubst_copy_and_build (function, args, complain,
12114 integral_constant_expression_p);
12116 if (BASELINK_P (function))
12117 qualified_p = true;
12120 nargs = call_expr_nargs (t);
12121 call_args = make_tree_vector ();
12122 for (i = 0; i < nargs; ++i)
12124 tree arg = CALL_EXPR_ARG (t, i);
12126 if (!PACK_EXPANSION_P (arg))
12127 VEC_safe_push (tree, gc, call_args,
12128 RECUR (CALL_EXPR_ARG (t, i)));
12131 /* Expand the pack expansion and push each entry onto
12133 arg = tsubst_pack_expansion (arg, args, complain, in_decl);
12134 if (TREE_CODE (arg) == TREE_VEC)
12136 unsigned int len, j;
12138 len = TREE_VEC_LENGTH (arg);
12139 for (j = 0; j < len; ++j)
12141 tree value = TREE_VEC_ELT (arg, j);
12142 if (value != NULL_TREE)
12143 value = convert_from_reference (value);
12144 VEC_safe_push (tree, gc, call_args, value);
12149 /* A partial substitution. Add one entry. */
12150 VEC_safe_push (tree, gc, call_args, arg);
12155 /* We do not perform argument-dependent lookup if normal
12156 lookup finds a non-function, in accordance with the
12157 expected resolution of DR 218. */
12159 && ((is_overloaded_fn (function)
12160 /* If lookup found a member function, the Koenig lookup is
12161 not appropriate, even if an unqualified-name was used
12162 to denote the function. */
12163 && !DECL_FUNCTION_MEMBER_P (get_first_fn (function)))
12164 || TREE_CODE (function) == IDENTIFIER_NODE)
12165 /* Only do this when substitution turns a dependent call
12166 into a non-dependent call. */
12167 && type_dependent_expression_p_push (t)
12168 && !any_type_dependent_arguments_p (call_args))
12169 function = perform_koenig_lookup (function, call_args);
12171 if (TREE_CODE (function) == IDENTIFIER_NODE)
12173 unqualified_name_lookup_error (function);
12174 release_tree_vector (call_args);
12175 return error_mark_node;
12178 /* Remember that there was a reference to this entity. */
12179 if (DECL_P (function))
12180 mark_used (function);
12182 if (TREE_CODE (function) == OFFSET_REF)
12183 ret = build_offset_ref_call_from_tree (function, &call_args);
12184 else if (TREE_CODE (function) == COMPONENT_REF)
12186 if (!BASELINK_P (TREE_OPERAND (function, 1)))
12187 ret = finish_call_expr (function, &call_args,
12188 /*disallow_virtual=*/false,
12189 /*koenig_p=*/false,
12192 ret = (build_new_method_call
12193 (TREE_OPERAND (function, 0),
12194 TREE_OPERAND (function, 1),
12195 &call_args, NULL_TREE,
12196 qualified_p ? LOOKUP_NONVIRTUAL : LOOKUP_NORMAL,
12201 ret = finish_call_expr (function, &call_args,
12202 /*disallow_virtual=*/qualified_p,
12206 release_tree_vector (call_args);
12212 return build_x_conditional_expr
12213 (RECUR (TREE_OPERAND (t, 0)),
12214 RECUR (TREE_OPERAND (t, 1)),
12215 RECUR (TREE_OPERAND (t, 2)),
12218 case PSEUDO_DTOR_EXPR:
12219 return finish_pseudo_destructor_expr
12220 (RECUR (TREE_OPERAND (t, 0)),
12221 RECUR (TREE_OPERAND (t, 1)),
12222 RECUR (TREE_OPERAND (t, 2)));
12226 tree purpose, value, chain;
12228 if (t == void_list_node)
12231 if ((TREE_PURPOSE (t) && PACK_EXPANSION_P (TREE_PURPOSE (t)))
12232 || (TREE_VALUE (t) && PACK_EXPANSION_P (TREE_VALUE (t))))
12234 /* We have pack expansions, so expand those and
12235 create a new list out of it. */
12236 tree purposevec = NULL_TREE;
12237 tree valuevec = NULL_TREE;
12241 /* Expand the argument expressions. */
12242 if (TREE_PURPOSE (t))
12243 purposevec = tsubst_pack_expansion (TREE_PURPOSE (t), args,
12244 complain, in_decl);
12245 if (TREE_VALUE (t))
12246 valuevec = tsubst_pack_expansion (TREE_VALUE (t), args,
12247 complain, in_decl);
12249 /* Build the rest of the list. */
12250 chain = TREE_CHAIN (t);
12251 if (chain && chain != void_type_node)
12252 chain = RECUR (chain);
12254 /* Determine the number of arguments. */
12255 if (purposevec && TREE_CODE (purposevec) == TREE_VEC)
12257 len = TREE_VEC_LENGTH (purposevec);
12258 gcc_assert (!valuevec || len == TREE_VEC_LENGTH (valuevec));
12260 else if (TREE_CODE (valuevec) == TREE_VEC)
12261 len = TREE_VEC_LENGTH (valuevec);
12264 /* Since we only performed a partial substitution into
12265 the argument pack, we only return a single list
12267 if (purposevec == TREE_PURPOSE (t)
12268 && valuevec == TREE_VALUE (t)
12269 && chain == TREE_CHAIN (t))
12272 return tree_cons (purposevec, valuevec, chain);
12275 /* Convert the argument vectors into a TREE_LIST */
12279 /* Grab the Ith values. */
12281 purpose = purposevec ? TREE_VEC_ELT (purposevec, i)
12284 = valuevec ? convert_from_reference (TREE_VEC_ELT (valuevec, i))
12287 /* Build the list (backwards). */
12288 chain = tree_cons (purpose, value, chain);
12294 purpose = TREE_PURPOSE (t);
12296 purpose = RECUR (purpose);
12297 value = TREE_VALUE (t);
12299 value = RECUR (value);
12300 chain = TREE_CHAIN (t);
12301 if (chain && chain != void_type_node)
12302 chain = RECUR (chain);
12303 if (purpose == TREE_PURPOSE (t)
12304 && value == TREE_VALUE (t)
12305 && chain == TREE_CHAIN (t))
12307 return tree_cons (purpose, value, chain);
12310 case COMPONENT_REF:
12316 object = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
12317 args, complain, in_decl);
12318 /* Remember that there was a reference to this entity. */
12319 if (DECL_P (object))
12320 mark_used (object);
12321 object_type = TREE_TYPE (object);
12323 member = TREE_OPERAND (t, 1);
12324 if (BASELINK_P (member))
12325 member = tsubst_baselink (member,
12326 non_reference (TREE_TYPE (object)),
12327 args, complain, in_decl);
12329 member = tsubst_copy (member, args, complain, in_decl);
12330 if (member == error_mark_node)
12331 return error_mark_node;
12333 if (object_type && !CLASS_TYPE_P (object_type))
12335 if (SCALAR_TYPE_P (object_type))
12337 tree s = NULL_TREE;
12338 tree dtor = member;
12340 if (TREE_CODE (dtor) == SCOPE_REF)
12342 s = TREE_OPERAND (dtor, 0);
12343 dtor = TREE_OPERAND (dtor, 1);
12345 if (TREE_CODE (dtor) == BIT_NOT_EXPR)
12347 dtor = TREE_OPERAND (dtor, 0);
12349 return finish_pseudo_destructor_expr (object, s, dtor);
12353 else if (TREE_CODE (member) == SCOPE_REF
12354 && TREE_CODE (TREE_OPERAND (member, 1)) == TEMPLATE_ID_EXPR)
12359 /* Lookup the template functions now that we know what the
12361 tmpl = TREE_OPERAND (TREE_OPERAND (member, 1), 0);
12362 args = TREE_OPERAND (TREE_OPERAND (member, 1), 1);
12363 member = lookup_qualified_name (TREE_OPERAND (member, 0), tmpl,
12364 /*is_type_p=*/false,
12365 /*complain=*/false);
12366 if (BASELINK_P (member))
12368 BASELINK_FUNCTIONS (member)
12369 = build_nt (TEMPLATE_ID_EXPR, BASELINK_FUNCTIONS (member),
12371 member = (adjust_result_of_qualified_name_lookup
12372 (member, BINFO_TYPE (BASELINK_BINFO (member)),
12377 qualified_name_lookup_error (object_type, tmpl, member,
12379 return error_mark_node;
12382 else if (TREE_CODE (member) == SCOPE_REF
12383 && !CLASS_TYPE_P (TREE_OPERAND (member, 0))
12384 && TREE_CODE (TREE_OPERAND (member, 0)) != NAMESPACE_DECL)
12386 if (complain & tf_error)
12388 if (TYPE_P (TREE_OPERAND (member, 0)))
12389 error ("%qT is not a class or namespace",
12390 TREE_OPERAND (member, 0));
12392 error ("%qD is not a class or namespace",
12393 TREE_OPERAND (member, 0));
12395 return error_mark_node;
12397 else if (TREE_CODE (member) == FIELD_DECL)
12398 return finish_non_static_data_member (member, object, NULL_TREE);
12400 return finish_class_member_access_expr (object, member,
12401 /*template_p=*/false,
12407 (RECUR (TREE_OPERAND (t, 0)));
12411 VEC(constructor_elt,gc) *n;
12412 constructor_elt *ce;
12413 unsigned HOST_WIDE_INT idx;
12414 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12415 bool process_index_p;
12417 bool need_copy_p = false;
12420 if (type == error_mark_node)
12421 return error_mark_node;
12423 /* digest_init will do the wrong thing if we let it. */
12424 if (type && TYPE_PTRMEMFUNC_P (type))
12427 /* We do not want to process the index of aggregate
12428 initializers as they are identifier nodes which will be
12429 looked up by digest_init. */
12430 process_index_p = !(type && MAYBE_CLASS_TYPE_P (type));
12432 n = VEC_copy (constructor_elt, gc, CONSTRUCTOR_ELTS (t));
12433 newlen = VEC_length (constructor_elt, n);
12434 for (idx = 0; VEC_iterate (constructor_elt, n, idx, ce); idx++)
12436 if (ce->index && process_index_p)
12437 ce->index = RECUR (ce->index);
12439 if (PACK_EXPANSION_P (ce->value))
12441 /* Substitute into the pack expansion. */
12442 ce->value = tsubst_pack_expansion (ce->value, args, complain,
12445 if (ce->value == error_mark_node)
12447 else if (TREE_VEC_LENGTH (ce->value) == 1)
12448 /* Just move the argument into place. */
12449 ce->value = TREE_VEC_ELT (ce->value, 0);
12452 /* Update the length of the final CONSTRUCTOR
12453 arguments vector, and note that we will need to
12455 newlen = newlen + TREE_VEC_LENGTH (ce->value) - 1;
12456 need_copy_p = true;
12460 ce->value = RECUR (ce->value);
12465 VEC(constructor_elt,gc) *old_n = n;
12467 n = VEC_alloc (constructor_elt, gc, newlen);
12468 for (idx = 0; VEC_iterate (constructor_elt, old_n, idx, ce);
12471 if (TREE_CODE (ce->value) == TREE_VEC)
12473 int i, len = TREE_VEC_LENGTH (ce->value);
12474 for (i = 0; i < len; ++i)
12475 CONSTRUCTOR_APPEND_ELT (n, 0,
12476 TREE_VEC_ELT (ce->value, i));
12479 CONSTRUCTOR_APPEND_ELT (n, 0, ce->value);
12483 r = build_constructor (init_list_type_node, n);
12484 CONSTRUCTOR_IS_DIRECT_INIT (r) = CONSTRUCTOR_IS_DIRECT_INIT (t);
12486 if (TREE_HAS_CONSTRUCTOR (t))
12487 return finish_compound_literal (type, r);
12494 tree operand_0 = RECUR (TREE_OPERAND (t, 0));
12495 if (TYPE_P (operand_0))
12496 return get_typeid (operand_0);
12497 return build_typeid (operand_0);
12507 tree r = tsubst_copy (t, args, complain, in_decl);
12509 if (TREE_CODE (TREE_TYPE (t)) != REFERENCE_TYPE)
12510 /* If the original type was a reference, we'll be wrapped in
12511 the appropriate INDIRECT_REF. */
12512 r = convert_from_reference (r);
12517 return build_x_va_arg (RECUR (TREE_OPERAND (t, 0)),
12518 tsubst_copy (TREE_TYPE (t), args, complain,
12521 case OFFSETOF_EXPR:
12522 return finish_offsetof (RECUR (TREE_OPERAND (t, 0)));
12526 tree type1 = tsubst_copy (TRAIT_EXPR_TYPE1 (t), args,
12527 complain, in_decl);
12529 tree type2 = TRAIT_EXPR_TYPE2 (t);
12531 type2 = tsubst_copy (type2, args, complain, in_decl);
12533 return finish_trait_expr (TRAIT_EXPR_KIND (t), type1, type2);
12538 tree old_stmt_expr = cur_stmt_expr;
12539 tree stmt_expr = begin_stmt_expr ();
12541 cur_stmt_expr = stmt_expr;
12542 tsubst_expr (STMT_EXPR_STMT (t), args, complain, in_decl,
12543 integral_constant_expression_p);
12544 stmt_expr = finish_stmt_expr (stmt_expr, false);
12545 cur_stmt_expr = old_stmt_expr;
12551 t = tsubst_copy (t, args, complain, in_decl);
12552 /* As in finish_id_expression, we resolve enumeration constants
12553 to their underlying values. */
12554 if (TREE_CODE (t) == CONST_DECL)
12556 used_types_insert (TREE_TYPE (t));
12557 return DECL_INITIAL (t);
12563 tree r = build_lambda_expr ();
12565 tree type = tsubst (TREE_TYPE (t), args, complain, NULL_TREE);
12566 TREE_TYPE (r) = type;
12567 CLASSTYPE_LAMBDA_EXPR (type) = r;
12569 LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (r)
12570 = LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (t);
12571 LAMBDA_EXPR_MUTABLE_P (r) = LAMBDA_EXPR_MUTABLE_P (t);
12572 LAMBDA_EXPR_DISCRIMINATOR (r)
12573 = (LAMBDA_EXPR_DISCRIMINATOR (t));
12574 LAMBDA_EXPR_CAPTURE_LIST (r)
12575 = RECUR (LAMBDA_EXPR_CAPTURE_LIST (t));
12576 LAMBDA_EXPR_THIS_CAPTURE (r)
12577 = RECUR (LAMBDA_EXPR_THIS_CAPTURE (t));
12578 LAMBDA_EXPR_EXTRA_SCOPE (r)
12579 = RECUR (LAMBDA_EXPR_EXTRA_SCOPE (t));
12581 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
12582 determine_visibility (TYPE_NAME (type));
12583 /* Now that we know visibility, instantiate the type so we have a
12584 declaration of the op() for later calls to lambda_function. */
12585 complete_type (type);
12587 type = tsubst (LAMBDA_EXPR_RETURN_TYPE (t), args, complain, in_decl);
12589 apply_lambda_return_type (r, type);
12591 return build_lambda_object (r);
12595 /* Handle Objective-C++ constructs, if appropriate. */
12598 = objcp_tsubst_copy_and_build (t, args, complain,
12599 in_decl, /*function_p=*/false);
12603 return tsubst_copy (t, args, complain, in_decl);
12609 /* Verify that the instantiated ARGS are valid. For type arguments,
12610 make sure that the type's linkage is ok. For non-type arguments,
12611 make sure they are constants if they are integral or enumerations.
12612 Emit an error under control of COMPLAIN, and return TRUE on error. */
12615 check_instantiated_arg (tree tmpl, tree t, tsubst_flags_t complain)
12617 if (ARGUMENT_PACK_P (t))
12619 tree vec = ARGUMENT_PACK_ARGS (t);
12620 int len = TREE_VEC_LENGTH (vec);
12621 bool result = false;
12624 for (i = 0; i < len; ++i)
12625 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (vec, i), complain))
12629 else if (TYPE_P (t))
12631 /* [basic.link]: A name with no linkage (notably, the name
12632 of a class or enumeration declared in a local scope)
12633 shall not be used to declare an entity with linkage.
12634 This implies that names with no linkage cannot be used as
12637 DR 757 relaxes this restriction for C++0x. */
12638 tree nt = (cxx_dialect > cxx98 ? NULL_TREE
12639 : no_linkage_check (t, /*relaxed_p=*/false));
12643 /* DR 488 makes use of a type with no linkage cause
12644 type deduction to fail. */
12645 if (complain & tf_error)
12647 if (TYPE_ANONYMOUS_P (nt))
12648 error ("%qT is/uses anonymous type", t);
12650 error ("template argument for %qD uses local type %qT",
12655 /* In order to avoid all sorts of complications, we do not
12656 allow variably-modified types as template arguments. */
12657 else if (variably_modified_type_p (t, NULL_TREE))
12659 if (complain & tf_error)
12660 error ("%qT is a variably modified type", t);
12664 /* A non-type argument of integral or enumerated type must be a
12666 else if (TREE_TYPE (t)
12667 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t))
12668 && !TREE_CONSTANT (t))
12670 if (complain & tf_error)
12671 error ("integral expression %qE is not constant", t);
12678 check_instantiated_args (tree tmpl, tree args, tsubst_flags_t complain)
12680 int ix, len = DECL_NTPARMS (tmpl);
12681 bool result = false;
12683 for (ix = 0; ix != len; ix++)
12685 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (args, ix), complain))
12688 if (result && (complain & tf_error))
12689 error (" trying to instantiate %qD", tmpl);
12693 /* Instantiate the indicated variable or function template TMPL with
12694 the template arguments in TARG_PTR. */
12697 instantiate_template (tree tmpl, tree orig_args, tsubst_flags_t complain)
12699 tree targ_ptr = orig_args;
12703 HOST_WIDE_INT saved_processing_template_decl;
12705 if (tmpl == error_mark_node)
12706 return error_mark_node;
12708 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
12710 /* If this function is a clone, handle it specially. */
12711 if (DECL_CLONED_FUNCTION_P (tmpl))
12716 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
12717 DECL_CLONED_FUNCTION. */
12718 spec = instantiate_template (DECL_ABSTRACT_ORIGIN (tmpl),
12719 targ_ptr, complain);
12720 if (spec == error_mark_node)
12721 return error_mark_node;
12723 /* Look for the clone. */
12724 FOR_EACH_CLONE (clone, spec)
12725 if (DECL_NAME (clone) == DECL_NAME (tmpl))
12727 /* We should always have found the clone by now. */
12728 gcc_unreachable ();
12732 /* Check to see if we already have this specialization. */
12733 gen_tmpl = most_general_template (tmpl);
12734 if (tmpl != gen_tmpl)
12735 /* The TMPL is a partial instantiation. To get a full set of
12736 arguments we must add the arguments used to perform the
12737 partial instantiation. */
12738 targ_ptr = add_outermost_template_args (DECL_TI_ARGS (tmpl),
12741 /* It would be nice to avoid hashing here and then again in tsubst_decl,
12742 but it doesn't seem to be on the hot path. */
12743 spec = retrieve_specialization (gen_tmpl, targ_ptr, 0);
12745 gcc_assert (tmpl == gen_tmpl
12746 || ((fndecl = retrieve_specialization (tmpl, orig_args, 0))
12748 || fndecl == NULL_TREE);
12750 if (spec != NULL_TREE)
12753 if (check_instantiated_args (gen_tmpl, INNERMOST_TEMPLATE_ARGS (targ_ptr),
12755 return error_mark_node;
12757 /* We are building a FUNCTION_DECL, during which the access of its
12758 parameters and return types have to be checked. However this
12759 FUNCTION_DECL which is the desired context for access checking
12760 is not built yet. We solve this chicken-and-egg problem by
12761 deferring all checks until we have the FUNCTION_DECL. */
12762 push_deferring_access_checks (dk_deferred);
12764 /* Although PROCESSING_TEMPLATE_DECL may be true at this point
12765 (because, for example, we have encountered a non-dependent
12766 function call in the body of a template function and must now
12767 determine which of several overloaded functions will be called),
12768 within the instantiation itself we are not processing a
12770 saved_processing_template_decl = processing_template_decl;
12771 processing_template_decl = 0;
12772 /* Substitute template parameters to obtain the specialization. */
12773 fndecl = tsubst (DECL_TEMPLATE_RESULT (gen_tmpl),
12774 targ_ptr, complain, gen_tmpl);
12775 processing_template_decl = saved_processing_template_decl;
12776 if (fndecl == error_mark_node)
12777 return error_mark_node;
12779 /* Now we know the specialization, compute access previously
12781 push_access_scope (fndecl);
12783 /* Some typedefs referenced from within the template code need to be access
12784 checked at template instantiation time, i.e now. These types were
12785 added to the template at parsing time. Let's get those and perfom
12786 the acces checks then. */
12787 perform_typedefs_access_check (DECL_TEMPLATE_RESULT (tmpl), targ_ptr);
12788 perform_deferred_access_checks ();
12789 pop_access_scope (fndecl);
12790 pop_deferring_access_checks ();
12792 /* The DECL_TI_TEMPLATE should always be the immediate parent
12793 template, not the most general template. */
12794 DECL_TI_TEMPLATE (fndecl) = tmpl;
12796 /* If we've just instantiated the main entry point for a function,
12797 instantiate all the alternate entry points as well. We do this
12798 by cloning the instantiation of the main entry point, not by
12799 instantiating the template clones. */
12800 if (TREE_CHAIN (gen_tmpl) && DECL_CLONED_FUNCTION_P (TREE_CHAIN (gen_tmpl)))
12801 clone_function_decl (fndecl, /*update_method_vec_p=*/0);
12806 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
12807 NARGS elements of the arguments that are being used when calling
12808 it. TARGS is a vector into which the deduced template arguments
12811 Return zero for success, 2 for an incomplete match that doesn't resolve
12812 all the types, and 1 for complete failure. An error message will be
12813 printed only for an incomplete match.
12815 If FN is a conversion operator, or we are trying to produce a specific
12816 specialization, RETURN_TYPE is the return type desired.
12818 The EXPLICIT_TARGS are explicit template arguments provided via a
12821 The parameter STRICT is one of:
12824 We are deducing arguments for a function call, as in
12825 [temp.deduct.call].
12828 We are deducing arguments for a conversion function, as in
12829 [temp.deduct.conv].
12832 We are deducing arguments when doing an explicit instantiation
12833 as in [temp.explicit], when determining an explicit specialization
12834 as in [temp.expl.spec], or when taking the address of a function
12835 template, as in [temp.deduct.funcaddr]. */
12838 fn_type_unification (tree fn,
12839 tree explicit_targs,
12842 unsigned int nargs,
12844 unification_kind_t strict,
12850 bool incomplete_argument_packs_p = false;
12852 gcc_assert (TREE_CODE (fn) == TEMPLATE_DECL);
12854 fntype = TREE_TYPE (fn);
12855 if (explicit_targs)
12859 The specified template arguments must match the template
12860 parameters in kind (i.e., type, nontype, template), and there
12861 must not be more arguments than there are parameters;
12862 otherwise type deduction fails.
12864 Nontype arguments must match the types of the corresponding
12865 nontype template parameters, or must be convertible to the
12866 types of the corresponding nontype parameters as specified in
12867 _temp.arg.nontype_, otherwise type deduction fails.
12869 All references in the function type of the function template
12870 to the corresponding template parameters are replaced by the
12871 specified template argument values. If a substitution in a
12872 template parameter or in the function type of the function
12873 template results in an invalid type, type deduction fails. */
12874 tree tparms = DECL_INNERMOST_TEMPLATE_PARMS (fn);
12875 int i, len = TREE_VEC_LENGTH (tparms);
12876 tree converted_args;
12877 bool incomplete = false;
12879 if (explicit_targs == error_mark_node)
12883 = (coerce_template_parms (tparms, explicit_targs, NULL_TREE, tf_none,
12884 /*require_all_args=*/false,
12885 /*use_default_args=*/false));
12886 if (converted_args == error_mark_node)
12889 /* Substitute the explicit args into the function type. This is
12890 necessary so that, for instance, explicitly declared function
12891 arguments can match null pointed constants. If we were given
12892 an incomplete set of explicit args, we must not do semantic
12893 processing during substitution as we could create partial
12895 for (i = 0; i < len; i++)
12897 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
12898 bool parameter_pack = false;
12900 /* Dig out the actual parm. */
12901 if (TREE_CODE (parm) == TYPE_DECL
12902 || TREE_CODE (parm) == TEMPLATE_DECL)
12904 parm = TREE_TYPE (parm);
12905 parameter_pack = TEMPLATE_TYPE_PARAMETER_PACK (parm);
12907 else if (TREE_CODE (parm) == PARM_DECL)
12909 parm = DECL_INITIAL (parm);
12910 parameter_pack = TEMPLATE_PARM_PARAMETER_PACK (parm);
12913 if (parameter_pack)
12917 template_parm_level_and_index (parm, &level, &idx);
12919 /* Mark the argument pack as "incomplete". We could
12920 still deduce more arguments during unification. */
12921 targ = TMPL_ARG (converted_args, level, idx);
12924 ARGUMENT_PACK_INCOMPLETE_P(targ) = 1;
12925 ARGUMENT_PACK_EXPLICIT_ARGS (targ)
12926 = ARGUMENT_PACK_ARGS (targ);
12929 /* We have some incomplete argument packs. */
12930 incomplete_argument_packs_p = true;
12934 if (incomplete_argument_packs_p)
12935 /* Any substitution is guaranteed to be incomplete if there
12936 are incomplete argument packs, because we can still deduce
12940 incomplete = NUM_TMPL_ARGS (explicit_targs) != NUM_TMPL_ARGS (targs);
12942 processing_template_decl += incomplete;
12943 fntype = tsubst (fntype, converted_args, tf_none, NULL_TREE);
12944 processing_template_decl -= incomplete;
12946 if (fntype == error_mark_node)
12949 /* Place the explicitly specified arguments in TARGS. */
12950 for (i = NUM_TMPL_ARGS (converted_args); i--;)
12951 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (converted_args, i);
12954 /* Never do unification on the 'this' parameter. */
12955 parms = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (fntype));
12961 parms = tree_cons (NULL_TREE, TREE_TYPE (fntype), parms);
12962 new_args = XALLOCAVEC (tree, nargs + 1);
12963 new_args[0] = return_type;
12964 memcpy (new_args + 1, args, nargs * sizeof (tree));
12969 /* We allow incomplete unification without an error message here
12970 because the standard doesn't seem to explicitly prohibit it. Our
12971 callers must be ready to deal with unification failures in any
12973 result = type_unification_real (DECL_INNERMOST_TEMPLATE_PARMS (fn),
12974 targs, parms, args, nargs, /*subr=*/0,
12977 if (result == 0 && incomplete_argument_packs_p)
12979 int i, len = NUM_TMPL_ARGS (targs);
12981 /* Clear the "incomplete" flags on all argument packs. */
12982 for (i = 0; i < len; i++)
12984 tree arg = TREE_VEC_ELT (targs, i);
12985 if (ARGUMENT_PACK_P (arg))
12987 ARGUMENT_PACK_INCOMPLETE_P (arg) = 0;
12988 ARGUMENT_PACK_EXPLICIT_ARGS (arg) = NULL_TREE;
12993 /* Now that we have bindings for all of the template arguments,
12994 ensure that the arguments deduced for the template template
12995 parameters have compatible template parameter lists. We cannot
12996 check this property before we have deduced all template
12997 arguments, because the template parameter types of a template
12998 template parameter might depend on prior template parameters
12999 deduced after the template template parameter. The following
13000 ill-formed example illustrates this issue:
13002 template<typename T, template<T> class C> void f(C<5>, T);
13004 template<int N> struct X {};
13007 f(X<5>(), 5l); // error: template argument deduction fails
13010 The template parameter list of 'C' depends on the template type
13011 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
13012 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
13013 time that we deduce 'C'. */
13015 && !template_template_parm_bindings_ok_p
13016 (DECL_INNERMOST_TEMPLATE_PARMS (fn), targs))
13020 /* All is well so far. Now, check:
13024 When all template arguments have been deduced, all uses of
13025 template parameters in nondeduced contexts are replaced with
13026 the corresponding deduced argument values. If the
13027 substitution results in an invalid type, as described above,
13028 type deduction fails. */
13030 tree substed = tsubst (TREE_TYPE (fn), targs, tf_none, NULL_TREE);
13031 if (substed == error_mark_node)
13034 /* If we're looking for an exact match, check that what we got
13035 is indeed an exact match. It might not be if some template
13036 parameters are used in non-deduced contexts. */
13037 if (strict == DEDUCE_EXACT)
13042 = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (substed));
13044 sarg = tree_cons (NULL_TREE, TREE_TYPE (substed), sarg);
13045 for (i = 0; i < nargs && sarg; ++i, sarg = TREE_CHAIN (sarg))
13046 if (!same_type_p (args[i], TREE_VALUE (sarg)))
13054 /* Adjust types before performing type deduction, as described in
13055 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
13056 sections are symmetric. PARM is the type of a function parameter
13057 or the return type of the conversion function. ARG is the type of
13058 the argument passed to the call, or the type of the value
13059 initialized with the result of the conversion function.
13060 ARG_EXPR is the original argument expression, which may be null. */
13063 maybe_adjust_types_for_deduction (unification_kind_t strict,
13077 /* Swap PARM and ARG throughout the remainder of this
13078 function; the handling is precisely symmetric since PARM
13079 will initialize ARG rather than vice versa. */
13087 /* Core issue #873: Do the DR606 thing (see below) for these cases,
13088 too, but here handle it by stripping the reference from PARM
13089 rather than by adding it to ARG. */
13090 if (TREE_CODE (*parm) == REFERENCE_TYPE
13091 && TYPE_REF_IS_RVALUE (*parm)
13092 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
13093 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
13094 && TREE_CODE (*arg) == REFERENCE_TYPE
13095 && !TYPE_REF_IS_RVALUE (*arg))
13096 *parm = TREE_TYPE (*parm);
13097 /* Nothing else to do in this case. */
13101 gcc_unreachable ();
13104 if (TREE_CODE (*parm) != REFERENCE_TYPE)
13106 /* [temp.deduct.call]
13108 If P is not a reference type:
13110 --If A is an array type, the pointer type produced by the
13111 array-to-pointer standard conversion (_conv.array_) is
13112 used in place of A for type deduction; otherwise,
13114 --If A is a function type, the pointer type produced by
13115 the function-to-pointer standard conversion
13116 (_conv.func_) is used in place of A for type deduction;
13119 --If A is a cv-qualified type, the top level
13120 cv-qualifiers of A's type are ignored for type
13122 if (TREE_CODE (*arg) == ARRAY_TYPE)
13123 *arg = build_pointer_type (TREE_TYPE (*arg));
13124 else if (TREE_CODE (*arg) == FUNCTION_TYPE)
13125 *arg = build_pointer_type (*arg);
13127 *arg = TYPE_MAIN_VARIANT (*arg);
13130 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
13131 of the form T&&, where T is a template parameter, and the argument
13132 is an lvalue, T is deduced as A& */
13133 if (TREE_CODE (*parm) == REFERENCE_TYPE
13134 && TYPE_REF_IS_RVALUE (*parm)
13135 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
13136 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
13137 && arg_expr && real_lvalue_p (arg_expr))
13138 *arg = build_reference_type (*arg);
13140 /* [temp.deduct.call]
13142 If P is a cv-qualified type, the top level cv-qualifiers
13143 of P's type are ignored for type deduction. If P is a
13144 reference type, the type referred to by P is used for
13146 *parm = TYPE_MAIN_VARIANT (*parm);
13147 if (TREE_CODE (*parm) == REFERENCE_TYPE)
13149 *parm = TREE_TYPE (*parm);
13150 result |= UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
13153 /* DR 322. For conversion deduction, remove a reference type on parm
13154 too (which has been swapped into ARG). */
13155 if (strict == DEDUCE_CONV && TREE_CODE (*arg) == REFERENCE_TYPE)
13156 *arg = TREE_TYPE (*arg);
13161 /* Most parms like fn_type_unification.
13163 If SUBR is 1, we're being called recursively (to unify the
13164 arguments of a function or method parameter of a function
13168 type_unification_real (tree tparms,
13172 unsigned int xnargs,
13174 unification_kind_t strict,
13177 tree parm, arg, arg_expr;
13179 int ntparms = TREE_VEC_LENGTH (tparms);
13181 int saw_undeduced = 0;
13184 unsigned int nargs;
13187 gcc_assert (TREE_CODE (tparms) == TREE_VEC);
13188 gcc_assert (xparms == NULL_TREE || TREE_CODE (xparms) == TREE_LIST);
13189 gcc_assert (ntparms > 0);
13194 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL | UNIFY_ALLOW_MORE_CV_QUAL
13195 | UNIFY_ALLOW_DERIVED);
13199 sub_strict = UNIFY_ALLOW_LESS_CV_QUAL;
13203 sub_strict = UNIFY_ALLOW_NONE;
13207 gcc_unreachable ();
13216 while (parms && parms != void_list_node
13219 if (TREE_CODE (TREE_VALUE (parms)) == TYPE_PACK_EXPANSION)
13222 parm = TREE_VALUE (parms);
13223 parms = TREE_CHAIN (parms);
13228 if (arg == error_mark_node)
13230 if (arg == unknown_type_node)
13231 /* We can't deduce anything from this, but we might get all the
13232 template args from other function args. */
13235 /* Conversions will be performed on a function argument that
13236 corresponds with a function parameter that contains only
13237 non-deducible template parameters and explicitly specified
13238 template parameters. */
13239 if (!uses_template_parms (parm))
13244 type = TREE_TYPE (arg);
13248 if (same_type_p (parm, type))
13250 if (strict != DEDUCE_EXACT
13251 && can_convert_arg (parm, type, TYPE_P (arg) ? NULL_TREE : arg,
13260 gcc_assert (TREE_TYPE (arg) != NULL_TREE);
13261 if (type_unknown_p (arg))
13263 /* [temp.deduct.type]
13265 A template-argument can be deduced from a pointer to
13266 function or pointer to member function argument if
13267 the set of overloaded functions does not contain
13268 function templates and at most one of a set of
13269 overloaded functions provides a unique match. */
13270 if (resolve_overloaded_unification
13271 (tparms, targs, parm, arg, strict, sub_strict))
13277 arg = unlowered_expr_type (arg);
13278 if (arg == error_mark_node)
13283 int arg_strict = sub_strict;
13286 arg_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg,
13289 if (arg == init_list_type_node && arg_expr)
13291 if (unify (tparms, targs, parm, arg, arg_strict))
13298 && parms != void_list_node
13299 && TREE_CODE (TREE_VALUE (parms)) == TYPE_PACK_EXPANSION)
13301 /* Unify the remaining arguments with the pack expansion type. */
13303 tree parmvec = make_tree_vec (1);
13305 /* Allocate a TREE_VEC and copy in all of the arguments */
13306 argvec = make_tree_vec (nargs - ia);
13307 for (i = 0; ia < nargs; ++ia, ++i)
13308 TREE_VEC_ELT (argvec, i) = args[ia];
13310 /* Copy the parameter into parmvec. */
13311 TREE_VEC_ELT (parmvec, 0) = TREE_VALUE (parms);
13312 if (unify_pack_expansion (tparms, targs, parmvec, argvec, strict,
13313 /*call_args_p=*/true, /*subr=*/subr))
13316 /* Advance to the end of the list of parameters. */
13317 parms = TREE_CHAIN (parms);
13320 /* Fail if we've reached the end of the parm list, and more args
13321 are present, and the parm list isn't variadic. */
13322 if (ia < nargs && parms == void_list_node)
13324 /* Fail if parms are left and they don't have default values. */
13325 if (parms && parms != void_list_node
13326 && TREE_PURPOSE (parms) == NULL_TREE)
13330 for (i = 0; i < ntparms; i++)
13331 if (!TREE_VEC_ELT (targs, i))
13335 if (TREE_VEC_ELT (tparms, i) == error_mark_node)
13338 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
13340 /* If this is an undeduced nontype parameter that depends on
13341 a type parameter, try another pass; its type may have been
13342 deduced from a later argument than the one from which
13343 this parameter can be deduced. */
13344 if (TREE_CODE (tparm) == PARM_DECL
13345 && uses_template_parms (TREE_TYPE (tparm))
13346 && !saw_undeduced++)
13349 /* Core issue #226 (C++0x) [temp.deduct]:
13351 If a template argument has not been deduced, its
13352 default template argument, if any, is used.
13354 When we are in C++98 mode, TREE_PURPOSE will either
13355 be NULL_TREE or ERROR_MARK_NODE, so we do not need
13356 to explicitly check cxx_dialect here. */
13357 if (TREE_PURPOSE (TREE_VEC_ELT (tparms, i)))
13359 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
13360 tree arg = TREE_PURPOSE (TREE_VEC_ELT (tparms, i));
13361 arg = tsubst_template_arg (arg, targs, tf_none, NULL_TREE);
13362 arg = convert_template_argument (parm, arg, targs, tf_none,
13364 if (arg == error_mark_node)
13368 TREE_VEC_ELT (targs, i) = arg;
13373 /* If the type parameter is a parameter pack, then it will
13374 be deduced to an empty parameter pack. */
13375 if (template_parameter_pack_p (tparm))
13379 if (TREE_CODE (tparm) == TEMPLATE_PARM_INDEX)
13381 arg = make_node (NONTYPE_ARGUMENT_PACK);
13382 TREE_TYPE (arg) = TREE_TYPE (TEMPLATE_PARM_DECL (tparm));
13383 TREE_CONSTANT (arg) = 1;
13386 arg = cxx_make_type (TYPE_ARGUMENT_PACK);
13388 SET_ARGUMENT_PACK_ARGS (arg, make_tree_vec (0));
13390 TREE_VEC_ELT (targs, i) = arg;
13400 /* Subroutine of type_unification_real. Args are like the variables
13401 at the call site. ARG is an overloaded function (or template-id);
13402 we try deducing template args from each of the overloads, and if
13403 only one succeeds, we go with that. Modifies TARGS and returns
13404 true on success. */
13407 resolve_overloaded_unification (tree tparms,
13411 unification_kind_t strict,
13414 tree tempargs = copy_node (targs);
13416 tree goodfn = NULL_TREE;
13419 if (TREE_CODE (arg) == ADDR_EXPR)
13421 arg = TREE_OPERAND (arg, 0);
13427 if (TREE_CODE (arg) == COMPONENT_REF)
13428 /* Handle `&x' where `x' is some static or non-static member
13430 arg = TREE_OPERAND (arg, 1);
13432 if (TREE_CODE (arg) == OFFSET_REF)
13433 arg = TREE_OPERAND (arg, 1);
13435 /* Strip baselink information. */
13436 if (BASELINK_P (arg))
13437 arg = BASELINK_FUNCTIONS (arg);
13439 if (TREE_CODE (arg) == TEMPLATE_ID_EXPR)
13441 /* If we got some explicit template args, we need to plug them into
13442 the affected templates before we try to unify, in case the
13443 explicit args will completely resolve the templates in question. */
13445 tree expl_subargs = TREE_OPERAND (arg, 1);
13446 arg = TREE_OPERAND (arg, 0);
13448 for (; arg; arg = OVL_NEXT (arg))
13450 tree fn = OVL_CURRENT (arg);
13451 tree subargs, elem;
13453 if (TREE_CODE (fn) != TEMPLATE_DECL)
13456 ++processing_template_decl;
13457 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
13458 expl_subargs, /*check_ret=*/false);
13461 elem = tsubst (TREE_TYPE (fn), subargs, tf_none, NULL_TREE);
13462 if (try_one_overload (tparms, targs, tempargs, parm,
13463 elem, strict, sub_strict, addr_p)
13464 && (!goodfn || !decls_match (goodfn, elem)))
13470 --processing_template_decl;
13473 else if (TREE_CODE (arg) != OVERLOAD
13474 && TREE_CODE (arg) != FUNCTION_DECL)
13475 /* If ARG is, for example, "(0, &f)" then its type will be unknown
13476 -- but the deduction does not succeed because the expression is
13477 not just the function on its own. */
13480 for (; arg; arg = OVL_NEXT (arg))
13481 if (try_one_overload (tparms, targs, tempargs, parm,
13482 TREE_TYPE (OVL_CURRENT (arg)),
13483 strict, sub_strict, addr_p)
13484 && (!goodfn || !decls_match (goodfn, OVL_CURRENT (arg))))
13486 goodfn = OVL_CURRENT (arg);
13490 /* [temp.deduct.type] A template-argument can be deduced from a pointer
13491 to function or pointer to member function argument if the set of
13492 overloaded functions does not contain function templates and at most
13493 one of a set of overloaded functions provides a unique match.
13495 So if we found multiple possibilities, we return success but don't
13496 deduce anything. */
13500 int i = TREE_VEC_LENGTH (targs);
13502 if (TREE_VEC_ELT (tempargs, i))
13503 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (tempargs, i);
13511 /* Core DR 115: In contexts where deduction is done and fails, or in
13512 contexts where deduction is not done, if a template argument list is
13513 specified and it, along with any default template arguments, identifies
13514 a single function template specialization, then the template-id is an
13515 lvalue for the function template specialization. */
13518 resolve_nondeduced_context (tree orig_expr)
13520 tree expr, offset, baselink;
13523 if (!type_unknown_p (orig_expr))
13528 offset = NULL_TREE;
13529 baselink = NULL_TREE;
13531 if (TREE_CODE (expr) == ADDR_EXPR)
13533 expr = TREE_OPERAND (expr, 0);
13536 if (TREE_CODE (expr) == OFFSET_REF)
13539 expr = TREE_OPERAND (expr, 1);
13541 if (TREE_CODE (expr) == BASELINK)
13544 expr = BASELINK_FUNCTIONS (expr);
13547 if (TREE_CODE (expr) == TEMPLATE_ID_EXPR)
13550 tree goodfn = NULL_TREE;
13552 /* If we got some explicit template args, we need to plug them into
13553 the affected templates before we try to unify, in case the
13554 explicit args will completely resolve the templates in question. */
13556 tree expl_subargs = TREE_OPERAND (expr, 1);
13557 tree arg = TREE_OPERAND (expr, 0);
13558 tree badfn = NULL_TREE;
13559 tree badargs = NULL_TREE;
13561 for (; arg; arg = OVL_NEXT (arg))
13563 tree fn = OVL_CURRENT (arg);
13564 tree subargs, elem;
13566 if (TREE_CODE (fn) != TEMPLATE_DECL)
13569 ++processing_template_decl;
13570 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
13571 expl_subargs, /*check_ret=*/false);
13572 if (subargs && !any_dependent_template_arguments_p (subargs))
13574 elem = instantiate_template (fn, subargs, tf_none);
13575 if (elem == error_mark_node)
13580 else if (elem && (!goodfn || !decls_match (goodfn, elem)))
13586 --processing_template_decl;
13592 expr = build_baselink (BASELINK_BINFO (baselink),
13593 BASELINK_ACCESS_BINFO (baselink),
13594 expr, BASELINK_OPTYPE (baselink));
13596 expr = build2 (OFFSET_REF, TREE_TYPE (expr),
13597 TREE_OPERAND (offset, 0), expr);
13599 expr = build_address (expr);
13602 else if (good == 0 && badargs)
13603 /* There were no good options and at least one bad one, so let the
13604 user know what the problem is. */
13605 instantiate_template (badfn, badargs, tf_warning_or_error);
13610 /* Subroutine of resolve_overloaded_unification; does deduction for a single
13611 overload. Fills TARGS with any deduced arguments, or error_mark_node if
13612 different overloads deduce different arguments for a given parm.
13613 ADDR_P is true if the expression for which deduction is being
13614 performed was of the form "& fn" rather than simply "fn".
13616 Returns 1 on success. */
13619 try_one_overload (tree tparms,
13624 unification_kind_t strict,
13632 /* [temp.deduct.type] A template-argument can be deduced from a pointer
13633 to function or pointer to member function argument if the set of
13634 overloaded functions does not contain function templates and at most
13635 one of a set of overloaded functions provides a unique match.
13637 So if this is a template, just return success. */
13639 if (uses_template_parms (arg))
13642 if (TREE_CODE (arg) == METHOD_TYPE)
13643 arg = build_ptrmemfunc_type (build_pointer_type (arg));
13645 arg = build_pointer_type (arg);
13647 sub_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg, NULL);
13649 /* We don't copy orig_targs for this because if we have already deduced
13650 some template args from previous args, unify would complain when we
13651 try to deduce a template parameter for the same argument, even though
13652 there isn't really a conflict. */
13653 nargs = TREE_VEC_LENGTH (targs);
13654 tempargs = make_tree_vec (nargs);
13656 if (unify (tparms, tempargs, parm, arg, sub_strict) != 0)
13659 /* First make sure we didn't deduce anything that conflicts with
13660 explicitly specified args. */
13661 for (i = nargs; i--; )
13663 tree elt = TREE_VEC_ELT (tempargs, i);
13664 tree oldelt = TREE_VEC_ELT (orig_targs, i);
13668 else if (uses_template_parms (elt))
13669 /* Since we're unifying against ourselves, we will fill in
13670 template args used in the function parm list with our own
13671 template parms. Discard them. */
13672 TREE_VEC_ELT (tempargs, i) = NULL_TREE;
13673 else if (oldelt && !template_args_equal (oldelt, elt))
13677 for (i = nargs; i--; )
13679 tree elt = TREE_VEC_ELT (tempargs, i);
13682 TREE_VEC_ELT (targs, i) = elt;
13688 /* PARM is a template class (perhaps with unbound template
13689 parameters). ARG is a fully instantiated type. If ARG can be
13690 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
13691 TARGS are as for unify. */
13694 try_class_unification (tree tparms, tree targs, tree parm, tree arg)
13696 tree copy_of_targs;
13698 if (!CLASSTYPE_TEMPLATE_INFO (arg)
13699 || (most_general_template (CLASSTYPE_TI_TEMPLATE (arg))
13700 != most_general_template (CLASSTYPE_TI_TEMPLATE (parm))))
13703 /* We need to make a new template argument vector for the call to
13704 unify. If we used TARGS, we'd clutter it up with the result of
13705 the attempted unification, even if this class didn't work out.
13706 We also don't want to commit ourselves to all the unifications
13707 we've already done, since unification is supposed to be done on
13708 an argument-by-argument basis. In other words, consider the
13709 following pathological case:
13711 template <int I, int J, int K>
13714 template <int I, int J>
13715 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
13717 template <int I, int J, int K>
13718 void f(S<I, J, K>, S<I, I, I>);
13727 Now, by the time we consider the unification involving `s2', we
13728 already know that we must have `f<0, 0, 0>'. But, even though
13729 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
13730 because there are two ways to unify base classes of S<0, 1, 2>
13731 with S<I, I, I>. If we kept the already deduced knowledge, we
13732 would reject the possibility I=1. */
13733 copy_of_targs = make_tree_vec (TREE_VEC_LENGTH (targs));
13735 /* If unification failed, we're done. */
13736 if (unify (tparms, copy_of_targs, CLASSTYPE_TI_ARGS (parm),
13737 CLASSTYPE_TI_ARGS (arg), UNIFY_ALLOW_NONE))
13743 /* Given a template type PARM and a class type ARG, find the unique
13744 base type in ARG that is an instance of PARM. We do not examine
13745 ARG itself; only its base-classes. If there is not exactly one
13746 appropriate base class, return NULL_TREE. PARM may be the type of
13747 a partial specialization, as well as a plain template type. Used
13751 get_template_base (tree tparms, tree targs, tree parm, tree arg)
13753 tree rval = NULL_TREE;
13756 gcc_assert (RECORD_OR_UNION_CODE_P (TREE_CODE (arg)));
13758 binfo = TYPE_BINFO (complete_type (arg));
13760 /* The type could not be completed. */
13763 /* Walk in inheritance graph order. The search order is not
13764 important, and this avoids multiple walks of virtual bases. */
13765 for (binfo = TREE_CHAIN (binfo); binfo; binfo = TREE_CHAIN (binfo))
13767 tree r = try_class_unification (tparms, targs, parm, BINFO_TYPE (binfo));
13771 /* If there is more than one satisfactory baseclass, then:
13775 If they yield more than one possible deduced A, the type
13779 if (rval && !same_type_p (r, rval))
13789 /* Returns the level of DECL, which declares a template parameter. */
13792 template_decl_level (tree decl)
13794 switch (TREE_CODE (decl))
13797 case TEMPLATE_DECL:
13798 return TEMPLATE_TYPE_LEVEL (TREE_TYPE (decl));
13801 return TEMPLATE_PARM_LEVEL (DECL_INITIAL (decl));
13804 gcc_unreachable ();
13809 /* Decide whether ARG can be unified with PARM, considering only the
13810 cv-qualifiers of each type, given STRICT as documented for unify.
13811 Returns nonzero iff the unification is OK on that basis. */
13814 check_cv_quals_for_unify (int strict, tree arg, tree parm)
13816 int arg_quals = cp_type_quals (arg);
13817 int parm_quals = cp_type_quals (parm);
13819 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
13820 && !(strict & UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
13822 /* Although a CVR qualifier is ignored when being applied to a
13823 substituted template parameter ([8.3.2]/1 for example), that
13824 does not apply during deduction [14.8.2.4]/1, (even though
13825 that is not explicitly mentioned, [14.8.2.4]/9 indicates
13826 this). Except when we're allowing additional CV qualifiers
13827 at the outer level [14.8.2.1]/3,1st bullet. */
13828 if ((TREE_CODE (arg) == REFERENCE_TYPE
13829 || TREE_CODE (arg) == FUNCTION_TYPE
13830 || TREE_CODE (arg) == METHOD_TYPE)
13831 && (parm_quals & (TYPE_QUAL_CONST | TYPE_QUAL_VOLATILE)))
13834 if ((!POINTER_TYPE_P (arg) && TREE_CODE (arg) != TEMPLATE_TYPE_PARM)
13835 && (parm_quals & TYPE_QUAL_RESTRICT))
13839 if (!(strict & (UNIFY_ALLOW_MORE_CV_QUAL | UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
13840 && (arg_quals & parm_quals) != parm_quals)
13843 if (!(strict & (UNIFY_ALLOW_LESS_CV_QUAL | UNIFY_ALLOW_OUTER_LESS_CV_QUAL))
13844 && (parm_quals & arg_quals) != arg_quals)
13850 /* Determines the LEVEL and INDEX for the template parameter PARM. */
13852 template_parm_level_and_index (tree parm, int* level, int* index)
13854 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
13855 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
13856 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
13858 *index = TEMPLATE_TYPE_IDX (parm);
13859 *level = TEMPLATE_TYPE_LEVEL (parm);
13863 *index = TEMPLATE_PARM_IDX (parm);
13864 *level = TEMPLATE_PARM_LEVEL (parm);
13868 /* Unifies the remaining arguments in PACKED_ARGS with the pack
13869 expansion at the end of PACKED_PARMS. Returns 0 if the type
13870 deduction succeeds, 1 otherwise. STRICT is the same as in
13871 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
13872 call argument list. We'll need to adjust the arguments to make them
13873 types. SUBR tells us if this is from a recursive call to
13874 type_unification_real. */
13876 unify_pack_expansion (tree tparms, tree targs, tree packed_parms,
13877 tree packed_args, int strict, bool call_args_p,
13881 = TREE_VEC_ELT (packed_parms, TREE_VEC_LENGTH (packed_parms) - 1);
13882 tree pattern = PACK_EXPANSION_PATTERN (parm);
13883 tree pack, packs = NULL_TREE;
13884 int i, start = TREE_VEC_LENGTH (packed_parms) - 1;
13885 int len = TREE_VEC_LENGTH (packed_args);
13887 /* Determine the parameter packs we will be deducing from the
13888 pattern, and record their current deductions. */
13889 for (pack = PACK_EXPANSION_PARAMETER_PACKS (parm);
13890 pack; pack = TREE_CHAIN (pack))
13892 tree parm_pack = TREE_VALUE (pack);
13895 /* Determine the index and level of this parameter pack. */
13896 template_parm_level_and_index (parm_pack, &level, &idx);
13898 /* Keep track of the parameter packs and their corresponding
13900 packs = tree_cons (parm_pack, TMPL_ARG (targs, level, idx), packs);
13901 TREE_TYPE (packs) = make_tree_vec (len - start);
13904 /* Loop through all of the arguments that have not yet been
13905 unified and unify each with the pattern. */
13906 for (i = start; i < len; i++)
13908 tree parm = pattern;
13910 /* For each parameter pack, clear out the deduced value so that
13911 we can deduce it again. */
13912 for (pack = packs; pack; pack = TREE_CHAIN (pack))
13915 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
13917 TMPL_ARG (targs, level, idx) = NULL_TREE;
13920 /* Unify the pattern with the current argument. */
13922 tree arg = TREE_VEC_ELT (packed_args, i);
13923 tree arg_expr = NULL_TREE;
13924 int arg_strict = strict;
13925 bool skip_arg_p = false;
13931 /* This mirrors what we do in type_unification_real. */
13935 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL
13936 | UNIFY_ALLOW_MORE_CV_QUAL
13937 | UNIFY_ALLOW_DERIVED);
13941 sub_strict = UNIFY_ALLOW_LESS_CV_QUAL;
13945 sub_strict = UNIFY_ALLOW_NONE;
13949 gcc_unreachable ();
13954 gcc_assert (TREE_TYPE (arg) != NULL_TREE);
13955 if (type_unknown_p (arg))
13957 /* [temp.deduct.type] A template-argument can be
13958 deduced from a pointer to function or pointer
13959 to member function argument if the set of
13960 overloaded functions does not contain function
13961 templates and at most one of a set of
13962 overloaded functions provides a unique
13965 if (resolve_overloaded_unification
13966 (tparms, targs, parm, arg,
13967 (unification_kind_t) strict,
13977 arg = unlowered_expr_type (arg);
13978 if (arg == error_mark_node)
13983 arg_strict = sub_strict;
13987 maybe_adjust_types_for_deduction ((unification_kind_t) strict,
13988 &parm, &arg, arg_expr);
13993 if (unify (tparms, targs, parm, arg, arg_strict))
13998 /* For each parameter pack, collect the deduced value. */
13999 for (pack = packs; pack; pack = TREE_CHAIN (pack))
14002 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
14004 TREE_VEC_ELT (TREE_TYPE (pack), i - start) =
14005 TMPL_ARG (targs, level, idx);
14009 /* Verify that the results of unification with the parameter packs
14010 produce results consistent with what we've seen before, and make
14011 the deduced argument packs available. */
14012 for (pack = packs; pack; pack = TREE_CHAIN (pack))
14014 tree old_pack = TREE_VALUE (pack);
14015 tree new_args = TREE_TYPE (pack);
14016 int i, len = TREE_VEC_LENGTH (new_args);
14017 bool nondeduced_p = false;
14019 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
14020 actually deduce anything. */
14021 for (i = 0; i < len && !nondeduced_p; ++i)
14022 if (TREE_VEC_ELT (new_args, i) == NULL_TREE)
14023 nondeduced_p = true;
14027 if (old_pack && ARGUMENT_PACK_INCOMPLETE_P (old_pack))
14029 /* Prepend the explicit arguments onto NEW_ARGS. */
14030 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
14031 tree old_args = new_args;
14032 int i, explicit_len = TREE_VEC_LENGTH (explicit_args);
14033 int len = explicit_len + TREE_VEC_LENGTH (old_args);
14035 /* Copy the explicit arguments. */
14036 new_args = make_tree_vec (len);
14037 for (i = 0; i < explicit_len; i++)
14038 TREE_VEC_ELT (new_args, i) = TREE_VEC_ELT (explicit_args, i);
14040 /* Copy the deduced arguments. */
14041 for (; i < len; i++)
14042 TREE_VEC_ELT (new_args, i) =
14043 TREE_VEC_ELT (old_args, i - explicit_len);
14051 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
14053 /* Build the deduced *_ARGUMENT_PACK. */
14054 if (TREE_CODE (TREE_PURPOSE (pack)) == TEMPLATE_PARM_INDEX)
14056 result = make_node (NONTYPE_ARGUMENT_PACK);
14057 TREE_TYPE (result) =
14058 TREE_TYPE (TEMPLATE_PARM_DECL (TREE_PURPOSE (pack)));
14059 TREE_CONSTANT (result) = 1;
14062 result = cxx_make_type (TYPE_ARGUMENT_PACK);
14064 SET_ARGUMENT_PACK_ARGS (result, new_args);
14066 /* Note the deduced argument packs for this parameter
14068 TMPL_ARG (targs, level, idx) = result;
14070 else if (ARGUMENT_PACK_INCOMPLETE_P (old_pack)
14071 && (ARGUMENT_PACK_ARGS (old_pack)
14072 == ARGUMENT_PACK_EXPLICIT_ARGS (old_pack)))
14074 /* We only had the explicitly-provided arguments before, but
14075 now we have a complete set of arguments. */
14077 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
14078 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
14080 /* Keep the original deduced argument pack. */
14081 TMPL_ARG (targs, level, idx) = old_pack;
14083 SET_ARGUMENT_PACK_ARGS (old_pack, new_args);
14084 ARGUMENT_PACK_INCOMPLETE_P (old_pack) = 1;
14085 ARGUMENT_PACK_EXPLICIT_ARGS (old_pack) = explicit_args;
14087 else if (!comp_template_args (ARGUMENT_PACK_ARGS (old_pack),
14089 /* Inconsistent unification of this parameter pack. */
14095 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
14097 /* Keep the original deduced argument pack. */
14098 TMPL_ARG (targs, level, idx) = old_pack;
14105 /* Deduce the value of template parameters. TPARMS is the (innermost)
14106 set of template parameters to a template. TARGS is the bindings
14107 for those template parameters, as determined thus far; TARGS may
14108 include template arguments for outer levels of template parameters
14109 as well. PARM is a parameter to a template function, or a
14110 subcomponent of that parameter; ARG is the corresponding argument.
14111 This function attempts to match PARM with ARG in a manner
14112 consistent with the existing assignments in TARGS. If more values
14113 are deduced, then TARGS is updated.
14115 Returns 0 if the type deduction succeeds, 1 otherwise. The
14116 parameter STRICT is a bitwise or of the following flags:
14119 Require an exact match between PARM and ARG.
14120 UNIFY_ALLOW_MORE_CV_QUAL:
14121 Allow the deduced ARG to be more cv-qualified (by qualification
14122 conversion) than ARG.
14123 UNIFY_ALLOW_LESS_CV_QUAL:
14124 Allow the deduced ARG to be less cv-qualified than ARG.
14125 UNIFY_ALLOW_DERIVED:
14126 Allow the deduced ARG to be a template base class of ARG,
14127 or a pointer to a template base class of the type pointed to by
14129 UNIFY_ALLOW_INTEGER:
14130 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
14131 case for more information.
14132 UNIFY_ALLOW_OUTER_LEVEL:
14133 This is the outermost level of a deduction. Used to determine validity
14134 of qualification conversions. A valid qualification conversion must
14135 have const qualified pointers leading up to the inner type which
14136 requires additional CV quals, except at the outer level, where const
14137 is not required [conv.qual]. It would be normal to set this flag in
14138 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
14139 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
14140 This is the outermost level of a deduction, and PARM can be more CV
14141 qualified at this point.
14142 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
14143 This is the outermost level of a deduction, and PARM can be less CV
14144 qualified at this point. */
14147 unify (tree tparms, tree targs, tree parm, tree arg, int strict)
14152 int strict_in = strict;
14154 /* I don't think this will do the right thing with respect to types.
14155 But the only case I've seen it in so far has been array bounds, where
14156 signedness is the only information lost, and I think that will be
14158 while (TREE_CODE (parm) == NOP_EXPR)
14159 parm = TREE_OPERAND (parm, 0);
14161 if (arg == error_mark_node)
14163 if (arg == unknown_type_node
14164 || arg == init_list_type_node)
14165 /* We can't deduce anything from this, but we might get all the
14166 template args from other function args. */
14169 /* If PARM uses template parameters, then we can't bail out here,
14170 even if ARG == PARM, since we won't record unifications for the
14171 template parameters. We might need them if we're trying to
14172 figure out which of two things is more specialized. */
14173 if (arg == parm && !uses_template_parms (parm))
14176 /* Handle init lists early, so the rest of the function can assume
14177 we're dealing with a type. */
14178 if (BRACE_ENCLOSED_INITIALIZER_P (arg))
14182 tree orig_parm = parm;
14184 /* Replace T with std::initializer_list<T> for deduction. */
14185 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
14186 && flag_deduce_init_list)
14187 parm = listify (parm);
14189 if (!is_std_init_list (parm))
14190 /* We can only deduce from an initializer list argument if the
14191 parameter is std::initializer_list; otherwise this is a
14192 non-deduced context. */
14195 elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (parm), 0);
14197 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg), i, elt)
14199 int elt_strict = strict;
14200 if (!BRACE_ENCLOSED_INITIALIZER_P (elt))
14202 tree type = TREE_TYPE (elt);
14203 /* It should only be possible to get here for a call. */
14204 gcc_assert (elt_strict & UNIFY_ALLOW_OUTER_LEVEL);
14205 elt_strict |= maybe_adjust_types_for_deduction
14206 (DEDUCE_CALL, &elttype, &type, elt);
14210 if (unify (tparms, targs, elttype, elt, elt_strict))
14214 /* If the std::initializer_list<T> deduction worked, replace the
14215 deduced A with std::initializer_list<A>. */
14216 if (orig_parm != parm)
14218 idx = TEMPLATE_TYPE_IDX (orig_parm);
14219 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
14220 targ = listify (targ);
14221 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = targ;
14226 /* Immediately reject some pairs that won't unify because of
14227 cv-qualification mismatches. */
14228 if (TREE_CODE (arg) == TREE_CODE (parm)
14230 /* It is the elements of the array which hold the cv quals of an array
14231 type, and the elements might be template type parms. We'll check
14232 when we recurse. */
14233 && TREE_CODE (arg) != ARRAY_TYPE
14234 /* We check the cv-qualifiers when unifying with template type
14235 parameters below. We want to allow ARG `const T' to unify with
14236 PARM `T' for example, when computing which of two templates
14237 is more specialized, for example. */
14238 && TREE_CODE (arg) != TEMPLATE_TYPE_PARM
14239 && !check_cv_quals_for_unify (strict_in, arg, parm))
14242 if (!(strict & UNIFY_ALLOW_OUTER_LEVEL)
14243 && TYPE_P (parm) && !CP_TYPE_CONST_P (parm))
14244 strict &= ~UNIFY_ALLOW_MORE_CV_QUAL;
14245 strict &= ~UNIFY_ALLOW_OUTER_LEVEL;
14246 strict &= ~UNIFY_ALLOW_DERIVED;
14247 strict &= ~UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
14248 strict &= ~UNIFY_ALLOW_OUTER_LESS_CV_QUAL;
14250 switch (TREE_CODE (parm))
14252 case TYPENAME_TYPE:
14254 case UNBOUND_CLASS_TEMPLATE:
14255 /* In a type which contains a nested-name-specifier, template
14256 argument values cannot be deduced for template parameters used
14257 within the nested-name-specifier. */
14260 case TEMPLATE_TYPE_PARM:
14261 case TEMPLATE_TEMPLATE_PARM:
14262 case BOUND_TEMPLATE_TEMPLATE_PARM:
14263 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
14264 if (tparm == error_mark_node)
14267 if (TEMPLATE_TYPE_LEVEL (parm)
14268 != template_decl_level (tparm))
14269 /* The PARM is not one we're trying to unify. Just check
14270 to see if it matches ARG. */
14271 return (TREE_CODE (arg) == TREE_CODE (parm)
14272 && same_type_p (parm, arg)) ? 0 : 1;
14273 idx = TEMPLATE_TYPE_IDX (parm);
14274 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
14275 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, idx));
14277 /* Check for mixed types and values. */
14278 if ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
14279 && TREE_CODE (tparm) != TYPE_DECL)
14280 || (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
14281 && TREE_CODE (tparm) != TEMPLATE_DECL))
14284 if (TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
14286 /* ARG must be constructed from a template class or a template
14287 template parameter. */
14288 if (TREE_CODE (arg) != BOUND_TEMPLATE_TEMPLATE_PARM
14289 && !CLASSTYPE_SPECIALIZATION_OF_PRIMARY_TEMPLATE_P (arg))
14293 tree parmvec = TYPE_TI_ARGS (parm);
14294 tree argvec = INNERMOST_TEMPLATE_ARGS (TYPE_TI_ARGS (arg));
14296 = DECL_INNERMOST_TEMPLATE_PARMS
14297 (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (parm));
14299 int parm_variadic_p = 0;
14301 /* The resolution to DR150 makes clear that default
14302 arguments for an N-argument may not be used to bind T
14303 to a template template parameter with fewer than N
14304 parameters. It is not safe to permit the binding of
14305 default arguments as an extension, as that may change
14306 the meaning of a conforming program. Consider:
14308 struct Dense { static const unsigned int dim = 1; };
14310 template <template <typename> class View,
14312 void operator+(float, View<Block> const&);
14314 template <typename Block,
14315 unsigned int Dim = Block::dim>
14316 struct Lvalue_proxy { operator float() const; };
14320 Lvalue_proxy<Dense> p;
14325 Here, if Lvalue_proxy is permitted to bind to View, then
14326 the global operator+ will be used; if they are not, the
14327 Lvalue_proxy will be converted to float. */
14328 if (coerce_template_parms (parm_parms,
14330 TYPE_TI_TEMPLATE (parm),
14332 /*require_all_args=*/true,
14333 /*use_default_args=*/false)
14334 == error_mark_node)
14337 /* Deduce arguments T, i from TT<T> or TT<i>.
14338 We check each element of PARMVEC and ARGVEC individually
14339 rather than the whole TREE_VEC since they can have
14340 different number of elements. */
14342 parmvec = expand_template_argument_pack (parmvec);
14343 argvec = expand_template_argument_pack (argvec);
14345 len = TREE_VEC_LENGTH (parmvec);
14347 /* Check if the parameters end in a pack, making them
14350 && PACK_EXPANSION_P (TREE_VEC_ELT (parmvec, len - 1)))
14351 parm_variadic_p = 1;
14353 if (TREE_VEC_LENGTH (argvec) < len - parm_variadic_p)
14356 for (i = 0; i < len - parm_variadic_p; ++i)
14358 if (unify (tparms, targs,
14359 TREE_VEC_ELT (parmvec, i),
14360 TREE_VEC_ELT (argvec, i),
14365 if (parm_variadic_p
14366 && unify_pack_expansion (tparms, targs,
14369 /*call_args_p=*/false,
14373 arg = TYPE_TI_TEMPLATE (arg);
14375 /* Fall through to deduce template name. */
14378 if (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
14379 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
14381 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
14383 /* Simple cases: Value already set, does match or doesn't. */
14384 if (targ != NULL_TREE && template_args_equal (targ, arg))
14391 /* If PARM is `const T' and ARG is only `int', we don't have
14392 a match unless we are allowing additional qualification.
14393 If ARG is `const int' and PARM is just `T' that's OK;
14394 that binds `const int' to `T'. */
14395 if (!check_cv_quals_for_unify (strict_in | UNIFY_ALLOW_LESS_CV_QUAL,
14399 /* Consider the case where ARG is `const volatile int' and
14400 PARM is `const T'. Then, T should be `volatile int'. */
14401 arg = cp_build_qualified_type_real
14402 (arg, cp_type_quals (arg) & ~cp_type_quals (parm), tf_none);
14403 if (arg == error_mark_node)
14406 /* Simple cases: Value already set, does match or doesn't. */
14407 if (targ != NULL_TREE && same_type_p (targ, arg))
14412 /* Make sure that ARG is not a variable-sized array. (Note
14413 that were talking about variable-sized arrays (like
14414 `int[n]'), rather than arrays of unknown size (like
14415 `int[]').) We'll get very confused by such a type since
14416 the bound of the array will not be computable in an
14417 instantiation. Besides, such types are not allowed in
14418 ISO C++, so we can do as we please here. */
14419 if (variably_modified_type_p (arg, NULL_TREE))
14422 /* Strip typedefs as in convert_template_argument. */
14423 arg = strip_typedefs (arg);
14426 /* If ARG is a parameter pack or an expansion, we cannot unify
14427 against it unless PARM is also a parameter pack. */
14428 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
14429 && !template_parameter_pack_p (parm))
14432 /* If the argument deduction results is a METHOD_TYPE,
14433 then there is a problem.
14434 METHOD_TYPE doesn't map to any real C++ type the result of
14435 the deduction can not be of that type. */
14436 if (TREE_CODE (arg) == METHOD_TYPE)
14439 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
14442 case TEMPLATE_PARM_INDEX:
14443 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
14444 if (tparm == error_mark_node)
14447 if (TEMPLATE_PARM_LEVEL (parm)
14448 != template_decl_level (tparm))
14449 /* The PARM is not one we're trying to unify. Just check
14450 to see if it matches ARG. */
14451 return !(TREE_CODE (arg) == TREE_CODE (parm)
14452 && cp_tree_equal (parm, arg));
14454 idx = TEMPLATE_PARM_IDX (parm);
14455 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
14458 return !cp_tree_equal (targ, arg);
14460 /* [temp.deduct.type] If, in the declaration of a function template
14461 with a non-type template-parameter, the non-type
14462 template-parameter is used in an expression in the function
14463 parameter-list and, if the corresponding template-argument is
14464 deduced, the template-argument type shall match the type of the
14465 template-parameter exactly, except that a template-argument
14466 deduced from an array bound may be of any integral type.
14467 The non-type parameter might use already deduced type parameters. */
14468 tparm = tsubst (TREE_TYPE (parm), targs, 0, NULL_TREE);
14469 if (!TREE_TYPE (arg))
14470 /* Template-parameter dependent expression. Just accept it for now.
14471 It will later be processed in convert_template_argument. */
14473 else if (same_type_p (TREE_TYPE (arg), tparm))
14475 else if ((strict & UNIFY_ALLOW_INTEGER)
14476 && (TREE_CODE (tparm) == INTEGER_TYPE
14477 || TREE_CODE (tparm) == BOOLEAN_TYPE))
14478 /* Convert the ARG to the type of PARM; the deduced non-type
14479 template argument must exactly match the types of the
14480 corresponding parameter. */
14481 arg = fold (build_nop (tparm, arg));
14482 else if (uses_template_parms (tparm))
14483 /* We haven't deduced the type of this parameter yet. Try again
14489 /* If ARG is a parameter pack or an expansion, we cannot unify
14490 against it unless PARM is also a parameter pack. */
14491 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
14492 && !TEMPLATE_PARM_PARAMETER_PACK (parm))
14495 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
14500 /* A pointer-to-member constant can be unified only with
14501 another constant. */
14502 if (TREE_CODE (arg) != PTRMEM_CST)
14505 /* Just unify the class member. It would be useless (and possibly
14506 wrong, depending on the strict flags) to unify also
14507 PTRMEM_CST_CLASS, because we want to be sure that both parm and
14508 arg refer to the same variable, even if through different
14509 classes. For instance:
14511 struct A { int x; };
14514 Unification of &A::x and &B::x must succeed. */
14515 return unify (tparms, targs, PTRMEM_CST_MEMBER (parm),
14516 PTRMEM_CST_MEMBER (arg), strict);
14521 if (TREE_CODE (arg) != POINTER_TYPE)
14524 /* [temp.deduct.call]
14526 A can be another pointer or pointer to member type that can
14527 be converted to the deduced A via a qualification
14528 conversion (_conv.qual_).
14530 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
14531 This will allow for additional cv-qualification of the
14532 pointed-to types if appropriate. */
14534 if (TREE_CODE (TREE_TYPE (arg)) == RECORD_TYPE)
14535 /* The derived-to-base conversion only persists through one
14536 level of pointers. */
14537 strict |= (strict_in & UNIFY_ALLOW_DERIVED);
14539 return unify (tparms, targs, TREE_TYPE (parm),
14540 TREE_TYPE (arg), strict);
14543 case REFERENCE_TYPE:
14544 if (TREE_CODE (arg) != REFERENCE_TYPE)
14546 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
14547 strict & UNIFY_ALLOW_MORE_CV_QUAL);
14550 if (TREE_CODE (arg) != ARRAY_TYPE)
14552 if ((TYPE_DOMAIN (parm) == NULL_TREE)
14553 != (TYPE_DOMAIN (arg) == NULL_TREE))
14555 if (TYPE_DOMAIN (parm) != NULL_TREE)
14562 /* Our representation of array types uses "N - 1" as the
14563 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
14564 not an integer constant. We cannot unify arbitrarily
14565 complex expressions, so we eliminate the MINUS_EXPRs
14567 parm_max = TYPE_MAX_VALUE (TYPE_DOMAIN (parm));
14568 parm_cst = TREE_CODE (parm_max) == INTEGER_CST;
14571 gcc_assert (TREE_CODE (parm_max) == MINUS_EXPR);
14572 parm_max = TREE_OPERAND (parm_max, 0);
14574 arg_max = TYPE_MAX_VALUE (TYPE_DOMAIN (arg));
14575 arg_cst = TREE_CODE (arg_max) == INTEGER_CST;
14578 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
14579 trying to unify the type of a variable with the type
14580 of a template parameter. For example:
14582 template <unsigned int N>
14583 void f (char (&) [N]);
14590 Here, the type of the ARG will be "int [g(i)]", and
14591 may be a SAVE_EXPR, etc. */
14592 if (TREE_CODE (arg_max) != MINUS_EXPR)
14594 arg_max = TREE_OPERAND (arg_max, 0);
14597 /* If only one of the bounds used a MINUS_EXPR, compensate
14598 by adding one to the other bound. */
14599 if (parm_cst && !arg_cst)
14600 parm_max = fold_build2_loc (input_location, PLUS_EXPR,
14604 else if (arg_cst && !parm_cst)
14605 arg_max = fold_build2_loc (input_location, PLUS_EXPR,
14610 if (unify (tparms, targs, parm_max, arg_max, UNIFY_ALLOW_INTEGER))
14613 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
14614 strict & UNIFY_ALLOW_MORE_CV_QUAL);
14621 case ENUMERAL_TYPE:
14623 if (TREE_CODE (arg) != TREE_CODE (parm))
14626 /* We have already checked cv-qualification at the top of the
14628 if (!same_type_ignoring_top_level_qualifiers_p (arg, parm))
14631 /* As far as unification is concerned, this wins. Later checks
14632 will invalidate it if necessary. */
14635 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
14636 /* Type INTEGER_CST can come from ordinary constant template args. */
14638 while (TREE_CODE (arg) == NOP_EXPR)
14639 arg = TREE_OPERAND (arg, 0);
14641 if (TREE_CODE (arg) != INTEGER_CST)
14643 return !tree_int_cst_equal (parm, arg);
14648 if (TREE_CODE (arg) != TREE_VEC)
14650 if (TREE_VEC_LENGTH (parm) != TREE_VEC_LENGTH (arg))
14652 for (i = 0; i < TREE_VEC_LENGTH (parm); ++i)
14653 if (unify (tparms, targs,
14654 TREE_VEC_ELT (parm, i), TREE_VEC_ELT (arg, i),
14662 if (TREE_CODE (arg) != TREE_CODE (parm))
14665 if (TYPE_PTRMEMFUNC_P (parm))
14667 if (!TYPE_PTRMEMFUNC_P (arg))
14670 return unify (tparms, targs,
14671 TYPE_PTRMEMFUNC_FN_TYPE (parm),
14672 TYPE_PTRMEMFUNC_FN_TYPE (arg),
14676 if (CLASSTYPE_TEMPLATE_INFO (parm))
14678 tree t = NULL_TREE;
14680 if (strict_in & UNIFY_ALLOW_DERIVED)
14682 /* First, we try to unify the PARM and ARG directly. */
14683 t = try_class_unification (tparms, targs,
14688 /* Fallback to the special case allowed in
14689 [temp.deduct.call]:
14691 If P is a class, and P has the form
14692 template-id, then A can be a derived class of
14693 the deduced A. Likewise, if P is a pointer to
14694 a class of the form template-id, A can be a
14695 pointer to a derived class pointed to by the
14697 t = get_template_base (tparms, targs, parm, arg);
14703 else if (CLASSTYPE_TEMPLATE_INFO (arg)
14704 && (CLASSTYPE_TI_TEMPLATE (parm)
14705 == CLASSTYPE_TI_TEMPLATE (arg)))
14706 /* Perhaps PARM is something like S<U> and ARG is S<int>.
14707 Then, we should unify `int' and `U'. */
14710 /* There's no chance of unification succeeding. */
14713 return unify (tparms, targs, CLASSTYPE_TI_ARGS (parm),
14714 CLASSTYPE_TI_ARGS (t), UNIFY_ALLOW_NONE);
14716 else if (!same_type_ignoring_top_level_qualifiers_p (parm, arg))
14721 case FUNCTION_TYPE:
14723 unsigned int nargs;
14728 if (TREE_CODE (arg) != TREE_CODE (parm))
14731 /* CV qualifications for methods can never be deduced, they must
14732 match exactly. We need to check them explicitly here,
14733 because type_unification_real treats them as any other
14734 cv-qualified parameter. */
14735 if (TREE_CODE (parm) == METHOD_TYPE
14736 && (!check_cv_quals_for_unify
14738 TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (arg))),
14739 TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (parm))))))
14742 if (unify (tparms, targs, TREE_TYPE (parm),
14743 TREE_TYPE (arg), UNIFY_ALLOW_NONE))
14746 nargs = list_length (TYPE_ARG_TYPES (arg));
14747 args = XALLOCAVEC (tree, nargs);
14748 for (a = TYPE_ARG_TYPES (arg), i = 0;
14749 a != NULL_TREE && a != void_list_node;
14750 a = TREE_CHAIN (a), ++i)
14751 args[i] = TREE_VALUE (a);
14754 return type_unification_real (tparms, targs, TYPE_ARG_TYPES (parm),
14755 args, nargs, 1, DEDUCE_EXACT,
14760 /* Unify a pointer to member with a pointer to member function, which
14761 deduces the type of the member as a function type. */
14762 if (TYPE_PTRMEMFUNC_P (arg))
14766 cp_cv_quals cv_quals;
14768 /* Check top-level cv qualifiers */
14769 if (!check_cv_quals_for_unify (UNIFY_ALLOW_NONE, arg, parm))
14772 if (unify (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
14773 TYPE_PTRMEMFUNC_OBJECT_TYPE (arg), UNIFY_ALLOW_NONE))
14776 /* Determine the type of the function we are unifying against. */
14777 method_type = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (arg));
14779 build_function_type (TREE_TYPE (method_type),
14780 TREE_CHAIN (TYPE_ARG_TYPES (method_type)));
14782 /* Extract the cv-qualifiers of the member function from the
14783 implicit object parameter and place them on the function
14784 type to be restored later. */
14786 cp_type_quals(TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (method_type))));
14787 fntype = build_qualified_type (fntype, cv_quals);
14788 return unify (tparms, targs, TREE_TYPE (parm), fntype, strict);
14791 if (TREE_CODE (arg) != OFFSET_TYPE)
14793 if (unify (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
14794 TYPE_OFFSET_BASETYPE (arg), UNIFY_ALLOW_NONE))
14796 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
14800 if (DECL_TEMPLATE_PARM_P (parm))
14801 return unify (tparms, targs, DECL_INITIAL (parm), arg, strict);
14802 if (arg != integral_constant_value (parm))
14807 case TEMPLATE_DECL:
14808 /* Matched cases are handled by the ARG == PARM test above. */
14811 case TYPE_ARGUMENT_PACK:
14812 case NONTYPE_ARGUMENT_PACK:
14814 tree packed_parms = ARGUMENT_PACK_ARGS (parm);
14815 tree packed_args = ARGUMENT_PACK_ARGS (arg);
14816 int i, len = TREE_VEC_LENGTH (packed_parms);
14817 int argslen = TREE_VEC_LENGTH (packed_args);
14818 int parm_variadic_p = 0;
14820 for (i = 0; i < len; ++i)
14822 if (PACK_EXPANSION_P (TREE_VEC_ELT (packed_parms, i)))
14825 /* We can unify against something with a trailing
14827 parm_variadic_p = 1;
14829 /* Since there is something following the pack
14830 expansion, we cannot unify this template argument
14837 /* If we don't have enough arguments to satisfy the parameters
14838 (not counting the pack expression at the end), or we have
14839 too many arguments for a parameter list that doesn't end in
14840 a pack expression, we can't unify. */
14841 if (argslen < (len - parm_variadic_p)
14842 || (argslen > len && !parm_variadic_p))
14845 /* Unify all of the parameters that precede the (optional)
14846 pack expression. */
14847 for (i = 0; i < len - parm_variadic_p; ++i)
14849 if (unify (tparms, targs, TREE_VEC_ELT (packed_parms, i),
14850 TREE_VEC_ELT (packed_args, i), strict))
14854 if (parm_variadic_p)
14855 return unify_pack_expansion (tparms, targs,
14856 packed_parms, packed_args,
14857 strict, /*call_args_p=*/false,
14865 case DECLTYPE_TYPE:
14866 /* Cannot deduce anything from TYPEOF_TYPE or DECLTYPE_TYPE
14871 /* Unification fails if we hit an error node. */
14875 gcc_assert (EXPR_P (parm));
14877 /* We must be looking at an expression. This can happen with
14881 void foo(S<I>, S<I + 2>);
14883 This is a "nondeduced context":
14887 The nondeduced contexts are:
14889 --A type that is a template-id in which one or more of
14890 the template-arguments is an expression that references
14891 a template-parameter.
14893 In these cases, we assume deduction succeeded, but don't
14894 actually infer any unifications. */
14896 if (!uses_template_parms (parm)
14897 && !template_args_equal (parm, arg))
14904 /* Note that DECL can be defined in this translation unit, if
14908 mark_definable (tree decl)
14911 DECL_NOT_REALLY_EXTERN (decl) = 1;
14912 FOR_EACH_CLONE (clone, decl)
14913 DECL_NOT_REALLY_EXTERN (clone) = 1;
14916 /* Called if RESULT is explicitly instantiated, or is a member of an
14917 explicitly instantiated class. */
14920 mark_decl_instantiated (tree result, int extern_p)
14922 SET_DECL_EXPLICIT_INSTANTIATION (result);
14924 /* If this entity has already been written out, it's too late to
14925 make any modifications. */
14926 if (TREE_ASM_WRITTEN (result))
14929 if (TREE_CODE (result) != FUNCTION_DECL)
14930 /* The TREE_PUBLIC flag for function declarations will have been
14931 set correctly by tsubst. */
14932 TREE_PUBLIC (result) = 1;
14934 /* This might have been set by an earlier implicit instantiation. */
14935 DECL_COMDAT (result) = 0;
14938 DECL_NOT_REALLY_EXTERN (result) = 0;
14941 mark_definable (result);
14942 /* Always make artificials weak. */
14943 if (DECL_ARTIFICIAL (result) && flag_weak)
14944 comdat_linkage (result);
14945 /* For WIN32 we also want to put explicit instantiations in
14946 linkonce sections. */
14947 else if (TREE_PUBLIC (result))
14948 maybe_make_one_only (result);
14951 /* If EXTERN_P, then this function will not be emitted -- unless
14952 followed by an explicit instantiation, at which point its linkage
14953 will be adjusted. If !EXTERN_P, then this function will be
14954 emitted here. In neither circumstance do we want
14955 import_export_decl to adjust the linkage. */
14956 DECL_INTERFACE_KNOWN (result) = 1;
14959 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
14960 important template arguments. If any are missing, we check whether
14961 they're important by using error_mark_node for substituting into any
14962 args that were used for partial ordering (the ones between ARGS and END)
14963 and seeing if it bubbles up. */
14966 check_undeduced_parms (tree targs, tree args, tree end)
14968 bool found = false;
14970 for (i = TREE_VEC_LENGTH (targs) - 1; i >= 0; --i)
14971 if (TREE_VEC_ELT (targs, i) == NULL_TREE)
14974 TREE_VEC_ELT (targs, i) = error_mark_node;
14978 for (; args != end; args = TREE_CHAIN (args))
14980 tree substed = tsubst (TREE_VALUE (args), targs, tf_none, NULL_TREE);
14981 if (substed == error_mark_node)
14988 /* Given two function templates PAT1 and PAT2, return:
14990 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
14991 -1 if PAT2 is more specialized than PAT1.
14992 0 if neither is more specialized.
14994 LEN indicates the number of parameters we should consider
14995 (defaulted parameters should not be considered).
14997 The 1998 std underspecified function template partial ordering, and
14998 DR214 addresses the issue. We take pairs of arguments, one from
14999 each of the templates, and deduce them against each other. One of
15000 the templates will be more specialized if all the *other*
15001 template's arguments deduce against its arguments and at least one
15002 of its arguments *does* *not* deduce against the other template's
15003 corresponding argument. Deduction is done as for class templates.
15004 The arguments used in deduction have reference and top level cv
15005 qualifiers removed. Iff both arguments were originally reference
15006 types *and* deduction succeeds in both directions, the template
15007 with the more cv-qualified argument wins for that pairing (if
15008 neither is more cv-qualified, they both are equal). Unlike regular
15009 deduction, after all the arguments have been deduced in this way,
15010 we do *not* verify the deduced template argument values can be
15011 substituted into non-deduced contexts.
15013 The logic can be a bit confusing here, because we look at deduce1 and
15014 targs1 to see if pat2 is at least as specialized, and vice versa; if we
15015 can find template arguments for pat1 to make arg1 look like arg2, that
15016 means that arg2 is at least as specialized as arg1. */
15019 more_specialized_fn (tree pat1, tree pat2, int len)
15021 tree decl1 = DECL_TEMPLATE_RESULT (pat1);
15022 tree decl2 = DECL_TEMPLATE_RESULT (pat2);
15023 tree targs1 = make_tree_vec (DECL_NTPARMS (pat1));
15024 tree targs2 = make_tree_vec (DECL_NTPARMS (pat2));
15025 tree tparms1 = DECL_INNERMOST_TEMPLATE_PARMS (pat1);
15026 tree tparms2 = DECL_INNERMOST_TEMPLATE_PARMS (pat2);
15027 tree args1 = TYPE_ARG_TYPES (TREE_TYPE (decl1));
15028 tree args2 = TYPE_ARG_TYPES (TREE_TYPE (decl2));
15029 tree origs1, origs2;
15030 bool lose1 = false;
15031 bool lose2 = false;
15033 /* Remove the this parameter from non-static member functions. If
15034 one is a non-static member function and the other is not a static
15035 member function, remove the first parameter from that function
15036 also. This situation occurs for operator functions where we
15037 locate both a member function (with this pointer) and non-member
15038 operator (with explicit first operand). */
15039 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl1))
15041 len--; /* LEN is the number of significant arguments for DECL1 */
15042 args1 = TREE_CHAIN (args1);
15043 if (!DECL_STATIC_FUNCTION_P (decl2))
15044 args2 = TREE_CHAIN (args2);
15046 else if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl2))
15048 args2 = TREE_CHAIN (args2);
15049 if (!DECL_STATIC_FUNCTION_P (decl1))
15052 args1 = TREE_CHAIN (args1);
15056 /* If only one is a conversion operator, they are unordered. */
15057 if (DECL_CONV_FN_P (decl1) != DECL_CONV_FN_P (decl2))
15060 /* Consider the return type for a conversion function */
15061 if (DECL_CONV_FN_P (decl1))
15063 args1 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl1)), args1);
15064 args2 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl2)), args2);
15068 processing_template_decl++;
15074 /* Stop when an ellipsis is seen. */
15075 && args1 != NULL_TREE && args2 != NULL_TREE)
15077 tree arg1 = TREE_VALUE (args1);
15078 tree arg2 = TREE_VALUE (args2);
15079 int deduce1, deduce2;
15083 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
15084 && TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
15086 /* When both arguments are pack expansions, we need only
15087 unify the patterns themselves. */
15088 arg1 = PACK_EXPANSION_PATTERN (arg1);
15089 arg2 = PACK_EXPANSION_PATTERN (arg2);
15091 /* This is the last comparison we need to do. */
15095 if (TREE_CODE (arg1) == REFERENCE_TYPE)
15097 arg1 = TREE_TYPE (arg1);
15098 quals1 = cp_type_quals (arg1);
15101 if (TREE_CODE (arg2) == REFERENCE_TYPE)
15103 arg2 = TREE_TYPE (arg2);
15104 quals2 = cp_type_quals (arg2);
15107 if ((quals1 < 0) != (quals2 < 0))
15109 /* Only of the args is a reference, see if we should apply
15110 array/function pointer decay to it. This is not part of
15111 DR214, but is, IMHO, consistent with the deduction rules
15112 for the function call itself, and with our earlier
15113 implementation of the underspecified partial ordering
15114 rules. (nathan). */
15117 switch (TREE_CODE (arg1))
15120 arg1 = TREE_TYPE (arg1);
15122 case FUNCTION_TYPE:
15123 arg1 = build_pointer_type (arg1);
15132 switch (TREE_CODE (arg2))
15135 arg2 = TREE_TYPE (arg2);
15137 case FUNCTION_TYPE:
15138 arg2 = build_pointer_type (arg2);
15147 arg1 = TYPE_MAIN_VARIANT (arg1);
15148 arg2 = TYPE_MAIN_VARIANT (arg2);
15150 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION)
15152 int i, len2 = list_length (args2);
15153 tree parmvec = make_tree_vec (1);
15154 tree argvec = make_tree_vec (len2);
15157 /* Setup the parameter vector, which contains only ARG1. */
15158 TREE_VEC_ELT (parmvec, 0) = arg1;
15160 /* Setup the argument vector, which contains the remaining
15162 for (i = 0; i < len2; i++, ta = TREE_CHAIN (ta))
15163 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
15165 deduce1 = !unify_pack_expansion (tparms1, targs1, parmvec,
15166 argvec, UNIFY_ALLOW_NONE,
15167 /*call_args_p=*/false,
15170 /* We cannot deduce in the other direction, because ARG1 is
15171 a pack expansion but ARG2 is not. */
15174 else if (TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
15176 int i, len1 = list_length (args1);
15177 tree parmvec = make_tree_vec (1);
15178 tree argvec = make_tree_vec (len1);
15181 /* Setup the parameter vector, which contains only ARG1. */
15182 TREE_VEC_ELT (parmvec, 0) = arg2;
15184 /* Setup the argument vector, which contains the remaining
15186 for (i = 0; i < len1; i++, ta = TREE_CHAIN (ta))
15187 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
15189 deduce2 = !unify_pack_expansion (tparms2, targs2, parmvec,
15190 argvec, UNIFY_ALLOW_NONE,
15191 /*call_args_p=*/false,
15194 /* We cannot deduce in the other direction, because ARG2 is
15195 a pack expansion but ARG1 is not.*/
15201 /* The normal case, where neither argument is a pack
15203 deduce1 = !unify (tparms1, targs1, arg1, arg2, UNIFY_ALLOW_NONE);
15204 deduce2 = !unify (tparms2, targs2, arg2, arg1, UNIFY_ALLOW_NONE);
15207 /* If we couldn't deduce arguments for tparms1 to make arg1 match
15208 arg2, then arg2 is not as specialized as arg1. */
15214 /* "If, for a given type, deduction succeeds in both directions
15215 (i.e., the types are identical after the transformations above)
15216 and if the type from the argument template is more cv-qualified
15217 than the type from the parameter template (as described above)
15218 that type is considered to be more specialized than the other. If
15219 neither type is more cv-qualified than the other then neither type
15220 is more specialized than the other."
15222 We check same_type_p explicitly because deduction can also succeed
15223 in both directions when there is a nondeduced context. */
15224 if (deduce1 && deduce2
15225 && quals1 != quals2 && quals1 >= 0 && quals2 >= 0
15226 && same_type_p (arg1, arg2))
15228 if ((quals1 & quals2) == quals2)
15230 if ((quals1 & quals2) == quals1)
15234 if (lose1 && lose2)
15235 /* We've failed to deduce something in either direction.
15236 These must be unordered. */
15239 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
15240 || TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
15241 /* We have already processed all of the arguments in our
15242 handing of the pack expansion type. */
15245 args1 = TREE_CHAIN (args1);
15246 args2 = TREE_CHAIN (args2);
15249 /* "In most cases, all template parameters must have values in order for
15250 deduction to succeed, but for partial ordering purposes a template
15251 parameter may remain without a value provided it is not used in the
15252 types being used for partial ordering."
15254 Thus, if we are missing any of the targs1 we need to substitute into
15255 origs1, then pat2 is not as specialized as pat1. This can happen when
15256 there is a nondeduced context. */
15257 if (!lose2 && check_undeduced_parms (targs1, origs1, args1))
15259 if (!lose1 && check_undeduced_parms (targs2, origs2, args2))
15262 processing_template_decl--;
15264 /* All things being equal, if the next argument is a pack expansion
15265 for one function but not for the other, prefer the
15266 non-variadic function. FIXME this is bogus; see c++/41958. */
15268 && args1 && TREE_VALUE (args1)
15269 && args2 && TREE_VALUE (args2))
15271 lose1 = TREE_CODE (TREE_VALUE (args1)) == TYPE_PACK_EXPANSION;
15272 lose2 = TREE_CODE (TREE_VALUE (args2)) == TYPE_PACK_EXPANSION;
15275 if (lose1 == lose2)
15283 /* Determine which of two partial specializations is more specialized.
15285 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
15286 to the first partial specialization. The TREE_VALUE is the
15287 innermost set of template parameters for the partial
15288 specialization. PAT2 is similar, but for the second template.
15290 Return 1 if the first partial specialization is more specialized;
15291 -1 if the second is more specialized; 0 if neither is more
15294 See [temp.class.order] for information about determining which of
15295 two templates is more specialized. */
15298 more_specialized_class (tree pat1, tree pat2)
15303 bool any_deductions = false;
15305 tmpl1 = TREE_TYPE (pat1);
15306 tmpl2 = TREE_TYPE (pat2);
15308 /* Just like what happens for functions, if we are ordering between
15309 different class template specializations, we may encounter dependent
15310 types in the arguments, and we need our dependency check functions
15311 to behave correctly. */
15312 ++processing_template_decl;
15313 targs = get_class_bindings (TREE_VALUE (pat1),
15314 CLASSTYPE_TI_ARGS (tmpl1),
15315 CLASSTYPE_TI_ARGS (tmpl2));
15319 any_deductions = true;
15322 targs = get_class_bindings (TREE_VALUE (pat2),
15323 CLASSTYPE_TI_ARGS (tmpl2),
15324 CLASSTYPE_TI_ARGS (tmpl1));
15328 any_deductions = true;
15330 --processing_template_decl;
15332 /* In the case of a tie where at least one of the class templates
15333 has a parameter pack at the end, the template with the most
15334 non-packed parameters wins. */
15337 && (template_args_variadic_p (TREE_PURPOSE (pat1))
15338 || template_args_variadic_p (TREE_PURPOSE (pat2))))
15340 tree args1 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat1));
15341 tree args2 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat2));
15342 int len1 = TREE_VEC_LENGTH (args1);
15343 int len2 = TREE_VEC_LENGTH (args2);
15345 /* We don't count the pack expansion at the end. */
15346 if (template_args_variadic_p (TREE_PURPOSE (pat1)))
15348 if (template_args_variadic_p (TREE_PURPOSE (pat2)))
15353 else if (len1 < len2)
15360 /* Return the template arguments that will produce the function signature
15361 DECL from the function template FN, with the explicit template
15362 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
15363 also match. Return NULL_TREE if no satisfactory arguments could be
15367 get_bindings (tree fn, tree decl, tree explicit_args, bool check_rettype)
15369 int ntparms = DECL_NTPARMS (fn);
15370 tree targs = make_tree_vec (ntparms);
15372 tree decl_arg_types;
15374 unsigned int nargs, ix;
15377 /* Substitute the explicit template arguments into the type of DECL.
15378 The call to fn_type_unification will handle substitution into the
15380 decl_type = TREE_TYPE (decl);
15381 if (explicit_args && uses_template_parms (decl_type))
15384 tree converted_args;
15386 if (DECL_TEMPLATE_INFO (decl))
15387 tmpl = DECL_TI_TEMPLATE (decl);
15389 /* We can get here for some invalid specializations. */
15393 = coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
15394 explicit_args, NULL_TREE,
15396 /*require_all_args=*/false,
15397 /*use_default_args=*/false);
15398 if (converted_args == error_mark_node)
15401 decl_type = tsubst (decl_type, converted_args, tf_none, NULL_TREE);
15402 if (decl_type == error_mark_node)
15406 /* Never do unification on the 'this' parameter. */
15407 decl_arg_types = skip_artificial_parms_for (decl,
15408 TYPE_ARG_TYPES (decl_type));
15410 nargs = list_length (decl_arg_types);
15411 args = XALLOCAVEC (tree, nargs);
15412 for (arg = decl_arg_types, ix = 0;
15413 arg != NULL_TREE && arg != void_list_node;
15414 arg = TREE_CHAIN (arg), ++ix)
15415 args[ix] = TREE_VALUE (arg);
15417 if (fn_type_unification (fn, explicit_args, targs,
15419 (check_rettype || DECL_CONV_FN_P (fn)
15420 ? TREE_TYPE (decl_type) : NULL_TREE),
15421 DEDUCE_EXACT, LOOKUP_NORMAL))
15427 /* Return the innermost template arguments that, when applied to a
15428 template specialization whose innermost template parameters are
15429 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
15432 For example, suppose we have:
15434 template <class T, class U> struct S {};
15435 template <class T> struct S<T*, int> {};
15437 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
15438 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
15439 int}. The resulting vector will be {double}, indicating that `T'
15440 is bound to `double'. */
15443 get_class_bindings (tree tparms, tree spec_args, tree args)
15445 int i, ntparms = TREE_VEC_LENGTH (tparms);
15447 tree innermost_deduced_args;
15449 innermost_deduced_args = make_tree_vec (ntparms);
15450 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
15452 deduced_args = copy_node (args);
15453 SET_TMPL_ARGS_LEVEL (deduced_args,
15454 TMPL_ARGS_DEPTH (deduced_args),
15455 innermost_deduced_args);
15458 deduced_args = innermost_deduced_args;
15460 if (unify (tparms, deduced_args,
15461 INNERMOST_TEMPLATE_ARGS (spec_args),
15462 INNERMOST_TEMPLATE_ARGS (args),
15466 for (i = 0; i < ntparms; ++i)
15467 if (! TREE_VEC_ELT (innermost_deduced_args, i))
15470 /* Verify that nondeduced template arguments agree with the type
15471 obtained from argument deduction.
15475 struct A { typedef int X; };
15476 template <class T, class U> struct C {};
15477 template <class T> struct C<T, typename T::X> {};
15479 Then with the instantiation `C<A, int>', we can deduce that
15480 `T' is `A' but unify () does not check whether `typename T::X'
15482 spec_args = tsubst (spec_args, deduced_args, tf_none, NULL_TREE);
15483 if (spec_args == error_mark_node
15484 /* We only need to check the innermost arguments; the other
15485 arguments will always agree. */
15486 || !comp_template_args (INNERMOST_TEMPLATE_ARGS (spec_args),
15487 INNERMOST_TEMPLATE_ARGS (args)))
15490 /* Now that we have bindings for all of the template arguments,
15491 ensure that the arguments deduced for the template template
15492 parameters have compatible template parameter lists. See the use
15493 of template_template_parm_bindings_ok_p in fn_type_unification
15494 for more information. */
15495 if (!template_template_parm_bindings_ok_p (tparms, deduced_args))
15498 return deduced_args;
15501 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
15502 Return the TREE_LIST node with the most specialized template, if
15503 any. If there is no most specialized template, the error_mark_node
15506 Note that this function does not look at, or modify, the
15507 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
15508 returned is one of the elements of INSTANTIATIONS, callers may
15509 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
15510 and retrieve it from the value returned. */
15513 most_specialized_instantiation (tree templates)
15517 ++processing_template_decl;
15520 for (fn = TREE_CHAIN (templates); fn; fn = TREE_CHAIN (fn))
15524 if (get_bindings (TREE_VALUE (champ),
15525 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
15526 NULL_TREE, /*check_ret=*/false))
15529 if (get_bindings (TREE_VALUE (fn),
15530 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
15531 NULL_TREE, /*check_ret=*/false))
15538 /* Equally specialized, move to next function. If there
15539 is no next function, nothing's most specialized. */
15540 fn = TREE_CHAIN (fn);
15548 /* Now verify that champ is better than everything earlier in the
15549 instantiation list. */
15550 for (fn = templates; fn != champ; fn = TREE_CHAIN (fn))
15551 if (get_bindings (TREE_VALUE (champ),
15552 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
15553 NULL_TREE, /*check_ret=*/false)
15554 || !get_bindings (TREE_VALUE (fn),
15555 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
15556 NULL_TREE, /*check_ret=*/false))
15562 processing_template_decl--;
15565 return error_mark_node;
15570 /* If DECL is a specialization of some template, return the most
15571 general such template. Otherwise, returns NULL_TREE.
15573 For example, given:
15575 template <class T> struct S { template <class U> void f(U); };
15577 if TMPL is `template <class U> void S<int>::f(U)' this will return
15578 the full template. This function will not trace past partial
15579 specializations, however. For example, given in addition:
15581 template <class T> struct S<T*> { template <class U> void f(U); };
15583 if TMPL is `template <class U> void S<int*>::f(U)' this will return
15584 `template <class T> template <class U> S<T*>::f(U)'. */
15587 most_general_template (tree decl)
15589 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
15590 an immediate specialization. */
15591 if (TREE_CODE (decl) == FUNCTION_DECL)
15593 if (DECL_TEMPLATE_INFO (decl)) {
15594 decl = DECL_TI_TEMPLATE (decl);
15596 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
15597 template friend. */
15598 if (TREE_CODE (decl) != TEMPLATE_DECL)
15604 /* Look for more and more general templates. */
15605 while (DECL_TEMPLATE_INFO (decl))
15607 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
15608 (See cp-tree.h for details.) */
15609 if (TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
15612 if (CLASS_TYPE_P (TREE_TYPE (decl))
15613 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)))
15616 /* Stop if we run into an explicitly specialized class template. */
15617 if (!DECL_NAMESPACE_SCOPE_P (decl)
15618 && DECL_CONTEXT (decl)
15619 && CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (decl)))
15622 decl = DECL_TI_TEMPLATE (decl);
15628 /* Return the most specialized of the class template partial
15629 specializations of TMPL which can produce TYPE, a specialization of
15630 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
15631 a _TYPE node corresponding to the partial specialization, while the
15632 TREE_PURPOSE is the set of template arguments that must be
15633 substituted into the TREE_TYPE in order to generate TYPE.
15635 If the choice of partial specialization is ambiguous, a diagnostic
15636 is issued, and the error_mark_node is returned. If there are no
15637 partial specializations of TMPL matching TYPE, then NULL_TREE is
15641 most_specialized_class (tree type, tree tmpl)
15643 tree list = NULL_TREE;
15649 tree outer_args = NULL_TREE;
15651 tmpl = most_general_template (tmpl);
15652 args = CLASSTYPE_TI_ARGS (type);
15654 /* For determining which partial specialization to use, only the
15655 innermost args are interesting. */
15656 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
15658 outer_args = strip_innermost_template_args (args, 1);
15659 args = INNERMOST_TEMPLATE_ARGS (args);
15662 for (t = DECL_TEMPLATE_SPECIALIZATIONS (tmpl); t; t = TREE_CHAIN (t))
15664 tree partial_spec_args;
15666 tree parms = TREE_VALUE (t);
15668 partial_spec_args = CLASSTYPE_TI_ARGS (TREE_TYPE (t));
15673 ++processing_template_decl;
15675 /* Discard the outer levels of args, and then substitute in the
15676 template args from the enclosing class. */
15677 partial_spec_args = INNERMOST_TEMPLATE_ARGS (partial_spec_args);
15678 partial_spec_args = tsubst_template_args
15679 (partial_spec_args, outer_args, tf_none, NULL_TREE);
15681 /* PARMS already refers to just the innermost parms, but the
15682 template parms in partial_spec_args had their levels lowered
15683 by tsubst, so we need to do the same for the parm list. We
15684 can't just tsubst the TREE_VEC itself, as tsubst wants to
15685 treat a TREE_VEC as an argument vector. */
15686 parms = copy_node (parms);
15687 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
15688 TREE_VEC_ELT (parms, i) =
15689 tsubst (TREE_VEC_ELT (parms, i), outer_args, tf_none, NULL_TREE);
15691 --processing_template_decl;
15693 spec_args = get_class_bindings (parms,
15699 spec_args = add_to_template_args (outer_args, spec_args);
15700 list = tree_cons (spec_args, TREE_VALUE (t), list);
15701 TREE_TYPE (list) = TREE_TYPE (t);
15708 ambiguous_p = false;
15711 t = TREE_CHAIN (t);
15712 for (; t; t = TREE_CHAIN (t))
15714 fate = more_specialized_class (champ, t);
15721 t = TREE_CHAIN (t);
15724 ambiguous_p = true;
15733 for (t = list; t && t != champ; t = TREE_CHAIN (t))
15735 fate = more_specialized_class (champ, t);
15738 ambiguous_p = true;
15745 const char *str = "candidates are:";
15746 error ("ambiguous class template instantiation for %q#T", type);
15747 for (t = list; t; t = TREE_CHAIN (t))
15749 error ("%s %+#T", str, TREE_TYPE (t));
15752 return error_mark_node;
15758 /* Explicitly instantiate DECL. */
15761 do_decl_instantiation (tree decl, tree storage)
15763 tree result = NULL_TREE;
15766 if (!decl || decl == error_mark_node)
15767 /* An error occurred, for which grokdeclarator has already issued
15768 an appropriate message. */
15770 else if (! DECL_LANG_SPECIFIC (decl))
15772 error ("explicit instantiation of non-template %q#D", decl);
15775 else if (TREE_CODE (decl) == VAR_DECL)
15777 /* There is an asymmetry here in the way VAR_DECLs and
15778 FUNCTION_DECLs are handled by grokdeclarator. In the case of
15779 the latter, the DECL we get back will be marked as a
15780 template instantiation, and the appropriate
15781 DECL_TEMPLATE_INFO will be set up. This does not happen for
15782 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
15783 should handle VAR_DECLs as it currently handles
15785 if (!DECL_CLASS_SCOPE_P (decl))
15787 error ("%qD is not a static data member of a class template", decl);
15790 result = lookup_field (DECL_CONTEXT (decl), DECL_NAME (decl), 0, false);
15791 if (!result || TREE_CODE (result) != VAR_DECL)
15793 error ("no matching template for %qD found", decl);
15796 if (!same_type_p (TREE_TYPE (result), TREE_TYPE (decl)))
15798 error ("type %qT for explicit instantiation %qD does not match "
15799 "declared type %qT", TREE_TYPE (result), decl,
15804 else if (TREE_CODE (decl) != FUNCTION_DECL)
15806 error ("explicit instantiation of %q#D", decl);
15812 /* Check for various error cases. Note that if the explicit
15813 instantiation is valid the RESULT will currently be marked as an
15814 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
15815 until we get here. */
15817 if (DECL_TEMPLATE_SPECIALIZATION (result))
15819 /* DR 259 [temp.spec].
15821 Both an explicit instantiation and a declaration of an explicit
15822 specialization shall not appear in a program unless the explicit
15823 instantiation follows a declaration of the explicit specialization.
15825 For a given set of template parameters, if an explicit
15826 instantiation of a template appears after a declaration of an
15827 explicit specialization for that template, the explicit
15828 instantiation has no effect. */
15831 else if (DECL_EXPLICIT_INSTANTIATION (result))
15835 No program shall explicitly instantiate any template more
15838 We check DECL_NOT_REALLY_EXTERN so as not to complain when
15839 the first instantiation was `extern' and the second is not,
15840 and EXTERN_P for the opposite case. */
15841 if (DECL_NOT_REALLY_EXTERN (result) && !extern_p)
15842 permerror (input_location, "duplicate explicit instantiation of %q#D", result);
15843 /* If an "extern" explicit instantiation follows an ordinary
15844 explicit instantiation, the template is instantiated. */
15848 else if (!DECL_IMPLICIT_INSTANTIATION (result))
15850 error ("no matching template for %qD found", result);
15853 else if (!DECL_TEMPLATE_INFO (result))
15855 permerror (input_location, "explicit instantiation of non-template %q#D", result);
15859 if (storage == NULL_TREE)
15861 else if (storage == ridpointers[(int) RID_EXTERN])
15863 if (!in_system_header && (cxx_dialect == cxx98))
15864 pedwarn (input_location, OPT_pedantic,
15865 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
15870 error ("storage class %qD applied to template instantiation", storage);
15872 check_explicit_instantiation_namespace (result);
15873 mark_decl_instantiated (result, extern_p);
15875 instantiate_decl (result, /*defer_ok=*/1,
15876 /*expl_inst_class_mem_p=*/false);
15880 mark_class_instantiated (tree t, int extern_p)
15882 SET_CLASSTYPE_EXPLICIT_INSTANTIATION (t);
15883 SET_CLASSTYPE_INTERFACE_KNOWN (t);
15884 CLASSTYPE_INTERFACE_ONLY (t) = extern_p;
15885 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (t)) = extern_p;
15888 CLASSTYPE_DEBUG_REQUESTED (t) = 1;
15889 rest_of_type_compilation (t, 1);
15893 /* Called from do_type_instantiation through binding_table_foreach to
15894 do recursive instantiation for the type bound in ENTRY. */
15896 bt_instantiate_type_proc (binding_entry entry, void *data)
15898 tree storage = *(tree *) data;
15900 if (MAYBE_CLASS_TYPE_P (entry->type)
15901 && !uses_template_parms (CLASSTYPE_TI_ARGS (entry->type)))
15902 do_type_instantiation (TYPE_MAIN_DECL (entry->type), storage, 0);
15905 /* Called from do_type_instantiation to instantiate a member
15906 (a member function or a static member variable) of an
15907 explicitly instantiated class template. */
15909 instantiate_class_member (tree decl, int extern_p)
15911 mark_decl_instantiated (decl, extern_p);
15913 instantiate_decl (decl, /*defer_ok=*/1,
15914 /*expl_inst_class_mem_p=*/true);
15917 /* Perform an explicit instantiation of template class T. STORAGE, if
15918 non-null, is the RID for extern, inline or static. COMPLAIN is
15919 nonzero if this is called from the parser, zero if called recursively,
15920 since the standard is unclear (as detailed below). */
15923 do_type_instantiation (tree t, tree storage, tsubst_flags_t complain)
15928 int previous_instantiation_extern_p = 0;
15930 if (TREE_CODE (t) == TYPE_DECL)
15933 if (! CLASS_TYPE_P (t) || ! CLASSTYPE_TEMPLATE_INFO (t))
15935 error ("explicit instantiation of non-template type %qT", t);
15941 if (!COMPLETE_TYPE_P (t))
15943 if (complain & tf_error)
15944 error ("explicit instantiation of %q#T before definition of template",
15949 if (storage != NULL_TREE)
15951 if (!in_system_header)
15953 if (storage == ridpointers[(int) RID_EXTERN])
15955 if (cxx_dialect == cxx98)
15956 pedwarn (input_location, OPT_pedantic,
15957 "ISO C++ 1998 forbids the use of %<extern%> on "
15958 "explicit instantiations");
15961 pedwarn (input_location, OPT_pedantic,
15962 "ISO C++ forbids the use of %qE"
15963 " on explicit instantiations", storage);
15966 if (storage == ridpointers[(int) RID_INLINE])
15968 else if (storage == ridpointers[(int) RID_EXTERN])
15970 else if (storage == ridpointers[(int) RID_STATIC])
15974 error ("storage class %qD applied to template instantiation",
15980 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (t))
15982 /* DR 259 [temp.spec].
15984 Both an explicit instantiation and a declaration of an explicit
15985 specialization shall not appear in a program unless the explicit
15986 instantiation follows a declaration of the explicit specialization.
15988 For a given set of template parameters, if an explicit
15989 instantiation of a template appears after a declaration of an
15990 explicit specialization for that template, the explicit
15991 instantiation has no effect. */
15994 else if (CLASSTYPE_EXPLICIT_INSTANTIATION (t))
15998 No program shall explicitly instantiate any template more
16001 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
16002 instantiation was `extern'. If EXTERN_P then the second is.
16003 These cases are OK. */
16004 previous_instantiation_extern_p = CLASSTYPE_INTERFACE_ONLY (t);
16006 if (!previous_instantiation_extern_p && !extern_p
16007 && (complain & tf_error))
16008 permerror (input_location, "duplicate explicit instantiation of %q#T", t);
16010 /* If we've already instantiated the template, just return now. */
16011 if (!CLASSTYPE_INTERFACE_ONLY (t))
16015 check_explicit_instantiation_namespace (TYPE_NAME (t));
16016 mark_class_instantiated (t, extern_p);
16024 /* In contrast to implicit instantiation, where only the
16025 declarations, and not the definitions, of members are
16026 instantiated, we have here:
16030 The explicit instantiation of a class template specialization
16031 implies the instantiation of all of its members not
16032 previously explicitly specialized in the translation unit
16033 containing the explicit instantiation.
16035 Of course, we can't instantiate member template classes, since
16036 we don't have any arguments for them. Note that the standard
16037 is unclear on whether the instantiation of the members are
16038 *explicit* instantiations or not. However, the most natural
16039 interpretation is that it should be an explicit instantiation. */
16042 for (tmp = TYPE_METHODS (t); tmp; tmp = TREE_CHAIN (tmp))
16043 if (TREE_CODE (tmp) == FUNCTION_DECL
16044 && DECL_TEMPLATE_INSTANTIATION (tmp))
16045 instantiate_class_member (tmp, extern_p);
16047 for (tmp = TYPE_FIELDS (t); tmp; tmp = TREE_CHAIN (tmp))
16048 if (TREE_CODE (tmp) == VAR_DECL && DECL_TEMPLATE_INSTANTIATION (tmp))
16049 instantiate_class_member (tmp, extern_p);
16051 if (CLASSTYPE_NESTED_UTDS (t))
16052 binding_table_foreach (CLASSTYPE_NESTED_UTDS (t),
16053 bt_instantiate_type_proc, &storage);
16057 /* Given a function DECL, which is a specialization of TMPL, modify
16058 DECL to be a re-instantiation of TMPL with the same template
16059 arguments. TMPL should be the template into which tsubst'ing
16060 should occur for DECL, not the most general template.
16062 One reason for doing this is a scenario like this:
16065 void f(const T&, int i);
16067 void g() { f(3, 7); }
16070 void f(const T& t, const int i) { }
16072 Note that when the template is first instantiated, with
16073 instantiate_template, the resulting DECL will have no name for the
16074 first parameter, and the wrong type for the second. So, when we go
16075 to instantiate the DECL, we regenerate it. */
16078 regenerate_decl_from_template (tree decl, tree tmpl)
16080 /* The arguments used to instantiate DECL, from the most general
16085 args = DECL_TI_ARGS (decl);
16086 code_pattern = DECL_TEMPLATE_RESULT (tmpl);
16088 /* Make sure that we can see identifiers, and compute access
16090 push_access_scope (decl);
16092 if (TREE_CODE (decl) == FUNCTION_DECL)
16100 args_depth = TMPL_ARGS_DEPTH (args);
16101 parms_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
16102 if (args_depth > parms_depth)
16103 args = get_innermost_template_args (args, parms_depth);
16105 specs = tsubst_exception_specification (TREE_TYPE (code_pattern),
16106 args, tf_error, NULL_TREE);
16108 TREE_TYPE (decl) = build_exception_variant (TREE_TYPE (decl),
16111 /* Merge parameter declarations. */
16112 decl_parm = skip_artificial_parms_for (decl,
16113 DECL_ARGUMENTS (decl));
16115 = skip_artificial_parms_for (code_pattern,
16116 DECL_ARGUMENTS (code_pattern));
16117 while (decl_parm && !FUNCTION_PARAMETER_PACK_P (pattern_parm))
16122 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
16123 DECL_NAME (decl_parm) = DECL_NAME (pattern_parm);
16124 parm_type = tsubst (TREE_TYPE (pattern_parm), args, tf_error,
16126 parm_type = type_decays_to (parm_type);
16127 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
16128 TREE_TYPE (decl_parm) = parm_type;
16129 attributes = DECL_ATTRIBUTES (pattern_parm);
16130 if (DECL_ATTRIBUTES (decl_parm) != attributes)
16132 DECL_ATTRIBUTES (decl_parm) = attributes;
16133 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
16135 decl_parm = TREE_CHAIN (decl_parm);
16136 pattern_parm = TREE_CHAIN (pattern_parm);
16138 /* Merge any parameters that match with the function parameter
16140 if (pattern_parm && FUNCTION_PARAMETER_PACK_P (pattern_parm))
16143 tree expanded_types;
16144 /* Expand the TYPE_PACK_EXPANSION that provides the types for
16145 the parameters in this function parameter pack. */
16146 expanded_types = tsubst_pack_expansion (TREE_TYPE (pattern_parm),
16147 args, tf_error, NULL_TREE);
16148 len = TREE_VEC_LENGTH (expanded_types);
16149 for (i = 0; i < len; i++)
16154 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
16155 /* Rename the parameter to include the index. */
16156 DECL_NAME (decl_parm) =
16157 make_ith_pack_parameter_name (DECL_NAME (pattern_parm), i);
16158 parm_type = TREE_VEC_ELT (expanded_types, i);
16159 parm_type = type_decays_to (parm_type);
16160 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
16161 TREE_TYPE (decl_parm) = parm_type;
16162 attributes = DECL_ATTRIBUTES (pattern_parm);
16163 if (DECL_ATTRIBUTES (decl_parm) != attributes)
16165 DECL_ATTRIBUTES (decl_parm) = attributes;
16166 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
16168 decl_parm = TREE_CHAIN (decl_parm);
16171 /* Merge additional specifiers from the CODE_PATTERN. */
16172 if (DECL_DECLARED_INLINE_P (code_pattern)
16173 && !DECL_DECLARED_INLINE_P (decl))
16174 DECL_DECLARED_INLINE_P (decl) = 1;
16176 else if (TREE_CODE (decl) == VAR_DECL)
16177 DECL_INITIAL (decl) =
16178 tsubst_expr (DECL_INITIAL (code_pattern), args,
16179 tf_error, DECL_TI_TEMPLATE (decl),
16180 /*integral_constant_expression_p=*/false);
16182 gcc_unreachable ();
16184 pop_access_scope (decl);
16187 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
16188 substituted to get DECL. */
16191 template_for_substitution (tree decl)
16193 tree tmpl = DECL_TI_TEMPLATE (decl);
16195 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
16196 for the instantiation. This is not always the most general
16197 template. Consider, for example:
16200 struct S { template <class U> void f();
16201 template <> void f<int>(); };
16203 and an instantiation of S<double>::f<int>. We want TD to be the
16204 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
16205 while (/* An instantiation cannot have a definition, so we need a
16206 more general template. */
16207 DECL_TEMPLATE_INSTANTIATION (tmpl)
16208 /* We must also deal with friend templates. Given:
16210 template <class T> struct S {
16211 template <class U> friend void f() {};
16214 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
16215 so far as the language is concerned, but that's still
16216 where we get the pattern for the instantiation from. On
16217 other hand, if the definition comes outside the class, say:
16219 template <class T> struct S {
16220 template <class U> friend void f();
16222 template <class U> friend void f() {}
16224 we don't need to look any further. That's what the check for
16225 DECL_INITIAL is for. */
16226 || (TREE_CODE (decl) == FUNCTION_DECL
16227 && DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION (tmpl)
16228 && !DECL_INITIAL (DECL_TEMPLATE_RESULT (tmpl))))
16230 /* The present template, TD, should not be a definition. If it
16231 were a definition, we should be using it! Note that we
16232 cannot restructure the loop to just keep going until we find
16233 a template with a definition, since that might go too far if
16234 a specialization was declared, but not defined. */
16235 gcc_assert (TREE_CODE (decl) != VAR_DECL
16236 || DECL_IN_AGGR_P (DECL_TEMPLATE_RESULT (tmpl)));
16238 /* Fetch the more general template. */
16239 tmpl = DECL_TI_TEMPLATE (tmpl);
16245 /* Returns true if we need to instantiate this template instance even if we
16246 know we aren't going to emit it.. */
16249 always_instantiate_p (tree decl)
16251 /* We always instantiate inline functions so that we can inline them. An
16252 explicit instantiation declaration prohibits implicit instantiation of
16253 non-inline functions. With high levels of optimization, we would
16254 normally inline non-inline functions -- but we're not allowed to do
16255 that for "extern template" functions. Therefore, we check
16256 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
16257 return ((TREE_CODE (decl) == FUNCTION_DECL
16258 && DECL_DECLARED_INLINE_P (decl))
16259 /* And we need to instantiate static data members so that
16260 their initializers are available in integral constant
16262 || (TREE_CODE (decl) == VAR_DECL
16263 && DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (decl)));
16266 /* Produce the definition of D, a _DECL generated from a template. If
16267 DEFER_OK is nonzero, then we don't have to actually do the
16268 instantiation now; we just have to do it sometime. Normally it is
16269 an error if this is an explicit instantiation but D is undefined.
16270 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
16271 explicitly instantiated class template. */
16274 instantiate_decl (tree d, int defer_ok,
16275 bool expl_inst_class_mem_p)
16277 tree tmpl = DECL_TI_TEMPLATE (d);
16284 bool pattern_defined;
16286 location_t saved_loc = input_location;
16289 /* This function should only be used to instantiate templates for
16290 functions and static member variables. */
16291 gcc_assert (TREE_CODE (d) == FUNCTION_DECL
16292 || TREE_CODE (d) == VAR_DECL);
16294 /* Variables are never deferred; if instantiation is required, they
16295 are instantiated right away. That allows for better code in the
16296 case that an expression refers to the value of the variable --
16297 if the variable has a constant value the referring expression can
16298 take advantage of that fact. */
16299 if (TREE_CODE (d) == VAR_DECL)
16302 /* Don't instantiate cloned functions. Instead, instantiate the
16303 functions they cloned. */
16304 if (TREE_CODE (d) == FUNCTION_DECL && DECL_CLONED_FUNCTION_P (d))
16305 d = DECL_CLONED_FUNCTION (d);
16307 if (DECL_TEMPLATE_INSTANTIATED (d)
16308 || DECL_TEMPLATE_SPECIALIZATION (d))
16309 /* D has already been instantiated or explicitly specialized, so
16310 there's nothing for us to do here.
16312 It might seem reasonable to check whether or not D is an explicit
16313 instantiation, and, if so, stop here. But when an explicit
16314 instantiation is deferred until the end of the compilation,
16315 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
16316 the instantiation. */
16319 /* Check to see whether we know that this template will be
16320 instantiated in some other file, as with "extern template"
16322 external_p = (DECL_INTERFACE_KNOWN (d) && DECL_REALLY_EXTERN (d));
16324 /* In general, we do not instantiate such templates. */
16325 if (external_p && !always_instantiate_p (d))
16328 gen_tmpl = most_general_template (tmpl);
16329 gen_args = DECL_TI_ARGS (d);
16331 if (tmpl != gen_tmpl)
16332 /* We should already have the extra args. */
16333 gcc_assert (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (gen_tmpl))
16334 == TMPL_ARGS_DEPTH (gen_args));
16335 /* And what's in the hash table should match D. */
16336 gcc_assert ((spec = retrieve_specialization (gen_tmpl, gen_args, 0)) == d
16337 || spec == NULL_TREE);
16339 /* This needs to happen before any tsubsting. */
16340 if (! push_tinst_level (d))
16343 timevar_push (TV_PARSE);
16345 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
16346 for the instantiation. */
16347 td = template_for_substitution (d);
16348 code_pattern = DECL_TEMPLATE_RESULT (td);
16350 /* We should never be trying to instantiate a member of a class
16351 template or partial specialization. */
16352 gcc_assert (d != code_pattern);
16354 if ((DECL_NAMESPACE_SCOPE_P (d) && !DECL_INITIALIZED_IN_CLASS_P (d))
16355 || DECL_TEMPLATE_SPECIALIZATION (td))
16356 /* In the case of a friend template whose definition is provided
16357 outside the class, we may have too many arguments. Drop the
16358 ones we don't need. The same is true for specializations. */
16359 args = get_innermost_template_args
16360 (gen_args, TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (td)));
16364 if (TREE_CODE (d) == FUNCTION_DECL)
16365 pattern_defined = (DECL_SAVED_TREE (code_pattern) != NULL_TREE);
16367 pattern_defined = ! DECL_IN_AGGR_P (code_pattern);
16369 /* We may be in the middle of deferred access check. Disable it now. */
16370 push_deferring_access_checks (dk_no_deferred);
16372 /* Unless an explicit instantiation directive has already determined
16373 the linkage of D, remember that a definition is available for
16375 if (pattern_defined
16376 && !DECL_INTERFACE_KNOWN (d)
16377 && !DECL_NOT_REALLY_EXTERN (d))
16378 mark_definable (d);
16380 input_location = DECL_SOURCE_LOCATION (d);
16382 /* If D is a member of an explicitly instantiated class template,
16383 and no definition is available, treat it like an implicit
16385 if (!pattern_defined && expl_inst_class_mem_p
16386 && DECL_EXPLICIT_INSTANTIATION (d))
16388 DECL_NOT_REALLY_EXTERN (d) = 0;
16389 DECL_INTERFACE_KNOWN (d) = 0;
16390 SET_DECL_IMPLICIT_INSTANTIATION (d);
16393 /* Recheck the substitutions to obtain any warning messages
16394 about ignoring cv qualifiers. Don't do this for artificial decls,
16395 as it breaks the context-sensitive substitution for lambda op(). */
16396 if (!defer_ok && !DECL_ARTIFICIAL (d))
16398 tree gen = DECL_TEMPLATE_RESULT (gen_tmpl);
16399 tree type = TREE_TYPE (gen);
16401 /* Make sure that we can see identifiers, and compute access
16402 correctly. D is already the target FUNCTION_DECL with the
16404 push_access_scope (d);
16406 if (TREE_CODE (gen) == FUNCTION_DECL)
16408 tsubst (DECL_ARGUMENTS (gen), gen_args, tf_warning_or_error, d);
16409 tsubst_exception_specification (type, gen_args, tf_warning_or_error,
16411 /* Don't simply tsubst the function type, as that will give
16412 duplicate warnings about poor parameter qualifications.
16413 The function arguments are the same as the decl_arguments
16414 without the top level cv qualifiers. */
16415 type = TREE_TYPE (type);
16417 tsubst (type, gen_args, tf_warning_or_error, d);
16419 pop_access_scope (d);
16422 /* Defer all other templates, unless we have been explicitly
16423 forbidden from doing so. */
16424 if (/* If there is no definition, we cannot instantiate the
16427 /* If it's OK to postpone instantiation, do so. */
16429 /* If this is a static data member that will be defined
16430 elsewhere, we don't want to instantiate the entire data
16431 member, but we do want to instantiate the initializer so that
16432 we can substitute that elsewhere. */
16433 || (external_p && TREE_CODE (d) == VAR_DECL))
16435 /* The definition of the static data member is now required so
16436 we must substitute the initializer. */
16437 if (TREE_CODE (d) == VAR_DECL
16438 && !DECL_INITIAL (d)
16439 && DECL_INITIAL (code_pattern))
16444 ns = decl_namespace_context (d);
16445 push_nested_namespace (ns);
16446 push_nested_class (DECL_CONTEXT (d));
16447 init = tsubst_expr (DECL_INITIAL (code_pattern),
16449 tf_warning_or_error, NULL_TREE,
16450 /*integral_constant_expression_p=*/false);
16451 cp_finish_decl (d, init, /*init_const_expr_p=*/false,
16452 /*asmspec_tree=*/NULL_TREE,
16453 LOOKUP_ONLYCONVERTING);
16454 pop_nested_class ();
16455 pop_nested_namespace (ns);
16458 /* We restore the source position here because it's used by
16459 add_pending_template. */
16460 input_location = saved_loc;
16462 if (at_eof && !pattern_defined
16463 && DECL_EXPLICIT_INSTANTIATION (d)
16464 && DECL_NOT_REALLY_EXTERN (d))
16467 The definition of a non-exported function template, a
16468 non-exported member function template, or a non-exported
16469 member function or static data member of a class template
16470 shall be present in every translation unit in which it is
16471 explicitly instantiated. */
16472 permerror (input_location, "explicit instantiation of %qD "
16473 "but no definition available", d);
16475 /* ??? Historically, we have instantiated inline functions, even
16476 when marked as "extern template". */
16477 if (!(external_p && TREE_CODE (d) == VAR_DECL))
16478 add_pending_template (d);
16481 /* Tell the repository that D is available in this translation unit
16482 -- and see if it is supposed to be instantiated here. */
16483 if (TREE_PUBLIC (d) && !DECL_REALLY_EXTERN (d) && !repo_emit_p (d))
16485 /* In a PCH file, despite the fact that the repository hasn't
16486 requested instantiation in the PCH it is still possible that
16487 an instantiation will be required in a file that includes the
16490 add_pending_template (d);
16491 /* Instantiate inline functions so that the inliner can do its
16492 job, even though we'll not be emitting a copy of this
16494 if (!(TREE_CODE (d) == FUNCTION_DECL && possibly_inlined_p (d)))
16498 need_push = !cfun || !global_bindings_p ();
16500 push_to_top_level ();
16502 /* Mark D as instantiated so that recursive calls to
16503 instantiate_decl do not try to instantiate it again. */
16504 DECL_TEMPLATE_INSTANTIATED (d) = 1;
16506 /* Regenerate the declaration in case the template has been modified
16507 by a subsequent redeclaration. */
16508 regenerate_decl_from_template (d, td);
16510 /* We already set the file and line above. Reset them now in case
16511 they changed as a result of calling regenerate_decl_from_template. */
16512 input_location = DECL_SOURCE_LOCATION (d);
16514 if (TREE_CODE (d) == VAR_DECL)
16518 /* Clear out DECL_RTL; whatever was there before may not be right
16519 since we've reset the type of the declaration. */
16520 SET_DECL_RTL (d, NULL_RTX);
16521 DECL_IN_AGGR_P (d) = 0;
16523 /* The initializer is placed in DECL_INITIAL by
16524 regenerate_decl_from_template. Pull it out so that
16525 cp_finish_decl can process it. */
16526 init = DECL_INITIAL (d);
16527 DECL_INITIAL (d) = NULL_TREE;
16528 DECL_INITIALIZED_P (d) = 0;
16530 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
16531 initializer. That function will defer actual emission until
16532 we have a chance to determine linkage. */
16533 DECL_EXTERNAL (d) = 0;
16535 /* Enter the scope of D so that access-checking works correctly. */
16536 push_nested_class (DECL_CONTEXT (d));
16537 cp_finish_decl (d, init, false, NULL_TREE, 0);
16538 pop_nested_class ();
16540 else if (TREE_CODE (d) == FUNCTION_DECL)
16542 htab_t saved_local_specializations;
16547 /* Save away the current list, in case we are instantiating one
16548 template from within the body of another. */
16549 saved_local_specializations = local_specializations;
16551 /* Set up the list of local specializations. */
16552 local_specializations = htab_create (37,
16553 hash_local_specialization,
16554 eq_local_specializations,
16557 /* Set up context. */
16558 start_preparsed_function (d, NULL_TREE, SF_PRE_PARSED);
16560 /* Create substitution entries for the parameters. */
16561 subst_decl = DECL_TEMPLATE_RESULT (template_for_substitution (d));
16562 tmpl_parm = DECL_ARGUMENTS (subst_decl);
16563 spec_parm = DECL_ARGUMENTS (d);
16564 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (d))
16566 register_local_specialization (spec_parm, tmpl_parm);
16567 spec_parm = skip_artificial_parms_for (d, spec_parm);
16568 tmpl_parm = skip_artificial_parms_for (subst_decl, tmpl_parm);
16570 while (tmpl_parm && !FUNCTION_PARAMETER_PACK_P (tmpl_parm))
16572 register_local_specialization (spec_parm, tmpl_parm);
16573 tmpl_parm = TREE_CHAIN (tmpl_parm);
16574 spec_parm = TREE_CHAIN (spec_parm);
16576 if (tmpl_parm && FUNCTION_PARAMETER_PACK_P (tmpl_parm))
16578 /* Register the (value) argument pack as a specialization of
16579 TMPL_PARM, then move on. */
16580 tree argpack = make_fnparm_pack (spec_parm);
16581 register_local_specialization (argpack, tmpl_parm);
16582 tmpl_parm = TREE_CHAIN (tmpl_parm);
16583 spec_parm = NULL_TREE;
16585 gcc_assert (!spec_parm);
16587 /* Substitute into the body of the function. */
16588 tsubst_expr (DECL_SAVED_TREE (code_pattern), args,
16589 tf_warning_or_error, tmpl,
16590 /*integral_constant_expression_p=*/false);
16592 /* Set the current input_location to the end of the function
16593 so that finish_function knows where we are. */
16594 input_location = DECL_STRUCT_FUNCTION (code_pattern)->function_end_locus;
16596 /* We don't need the local specializations any more. */
16597 htab_delete (local_specializations);
16598 local_specializations = saved_local_specializations;
16600 /* Finish the function. */
16601 d = finish_function (0);
16602 expand_or_defer_fn (d);
16605 /* We're not deferring instantiation any more. */
16606 TI_PENDING_TEMPLATE_FLAG (DECL_TEMPLATE_INFO (d)) = 0;
16609 pop_from_top_level ();
16612 input_location = saved_loc;
16613 pop_deferring_access_checks ();
16614 pop_tinst_level ();
16616 timevar_pop (TV_PARSE);
16621 /* Run through the list of templates that we wish we could
16622 instantiate, and instantiate any we can. RETRIES is the
16623 number of times we retry pending template instantiation. */
16626 instantiate_pending_templates (int retries)
16629 location_t saved_loc = input_location;
16631 /* Instantiating templates may trigger vtable generation. This in turn
16632 may require further template instantiations. We place a limit here
16633 to avoid infinite loop. */
16634 if (pending_templates && retries >= max_tinst_depth)
16636 tree decl = pending_templates->tinst->decl;
16638 error ("template instantiation depth exceeds maximum of %d"
16639 " instantiating %q+D, possibly from virtual table generation"
16640 " (use -ftemplate-depth-NN to increase the maximum)",
16641 max_tinst_depth, decl);
16642 if (TREE_CODE (decl) == FUNCTION_DECL)
16643 /* Pretend that we defined it. */
16644 DECL_INITIAL (decl) = error_mark_node;
16650 struct pending_template **t = &pending_templates;
16651 struct pending_template *last = NULL;
16655 tree instantiation = reopen_tinst_level ((*t)->tinst);
16656 bool complete = false;
16658 if (TYPE_P (instantiation))
16662 if (!COMPLETE_TYPE_P (instantiation))
16664 instantiate_class_template (instantiation);
16665 if (CLASSTYPE_TEMPLATE_INSTANTIATION (instantiation))
16666 for (fn = TYPE_METHODS (instantiation);
16668 fn = TREE_CHAIN (fn))
16669 if (! DECL_ARTIFICIAL (fn))
16670 instantiate_decl (fn,
16672 /*expl_inst_class_mem_p=*/false);
16673 if (COMPLETE_TYPE_P (instantiation))
16677 complete = COMPLETE_TYPE_P (instantiation);
16681 if (!DECL_TEMPLATE_SPECIALIZATION (instantiation)
16682 && !DECL_TEMPLATE_INSTANTIATED (instantiation))
16685 = instantiate_decl (instantiation,
16687 /*expl_inst_class_mem_p=*/false);
16688 if (DECL_TEMPLATE_INSTANTIATED (instantiation))
16692 complete = (DECL_TEMPLATE_SPECIALIZATION (instantiation)
16693 || DECL_TEMPLATE_INSTANTIATED (instantiation));
16697 /* If INSTANTIATION has been instantiated, then we don't
16698 need to consider it again in the future. */
16706 current_tinst_level = NULL;
16708 last_pending_template = last;
16710 while (reconsider);
16712 input_location = saved_loc;
16715 /* Substitute ARGVEC into T, which is a list of initializers for
16716 either base class or a non-static data member. The TREE_PURPOSEs
16717 are DECLs, and the TREE_VALUEs are the initializer values. Used by
16718 instantiate_decl. */
16721 tsubst_initializer_list (tree t, tree argvec)
16723 tree inits = NULL_TREE;
16725 for (; t; t = TREE_CHAIN (t))
16729 tree expanded_bases = NULL_TREE;
16730 tree expanded_arguments = NULL_TREE;
16733 if (TREE_CODE (TREE_PURPOSE (t)) == TYPE_PACK_EXPANSION)
16738 /* Expand the base class expansion type into separate base
16740 expanded_bases = tsubst_pack_expansion (TREE_PURPOSE (t), argvec,
16741 tf_warning_or_error,
16743 if (expanded_bases == error_mark_node)
16746 /* We'll be building separate TREE_LISTs of arguments for
16748 len = TREE_VEC_LENGTH (expanded_bases);
16749 expanded_arguments = make_tree_vec (len);
16750 for (i = 0; i < len; i++)
16751 TREE_VEC_ELT (expanded_arguments, i) = NULL_TREE;
16753 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
16754 expand each argument in the TREE_VALUE of t. */
16755 expr = make_node (EXPR_PACK_EXPANSION);
16756 PACK_EXPANSION_PARAMETER_PACKS (expr) =
16757 PACK_EXPANSION_PARAMETER_PACKS (TREE_PURPOSE (t));
16759 if (TREE_VALUE (t) == void_type_node)
16760 /* VOID_TYPE_NODE is used to indicate
16761 value-initialization. */
16763 for (i = 0; i < len; i++)
16764 TREE_VEC_ELT (expanded_arguments, i) = void_type_node;
16768 /* Substitute parameter packs into each argument in the
16770 in_base_initializer = 1;
16771 for (arg = TREE_VALUE (t); arg; arg = TREE_CHAIN (arg))
16773 tree expanded_exprs;
16775 /* Expand the argument. */
16776 SET_PACK_EXPANSION_PATTERN (expr, TREE_VALUE (arg));
16778 = tsubst_pack_expansion (expr, argvec,
16779 tf_warning_or_error,
16781 if (expanded_exprs == error_mark_node)
16784 /* Prepend each of the expanded expressions to the
16785 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
16786 for (i = 0; i < len; i++)
16788 TREE_VEC_ELT (expanded_arguments, i) =
16789 tree_cons (NULL_TREE,
16790 TREE_VEC_ELT (expanded_exprs, i),
16791 TREE_VEC_ELT (expanded_arguments, i));
16794 in_base_initializer = 0;
16796 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
16797 since we built them backwards. */
16798 for (i = 0; i < len; i++)
16800 TREE_VEC_ELT (expanded_arguments, i) =
16801 nreverse (TREE_VEC_ELT (expanded_arguments, i));
16806 for (i = 0; i < len; ++i)
16808 if (expanded_bases)
16810 decl = TREE_VEC_ELT (expanded_bases, i);
16811 decl = expand_member_init (decl);
16812 init = TREE_VEC_ELT (expanded_arguments, i);
16816 decl = tsubst_copy (TREE_PURPOSE (t), argvec,
16817 tf_warning_or_error, NULL_TREE);
16819 decl = expand_member_init (decl);
16820 if (decl && !DECL_P (decl))
16821 in_base_initializer = 1;
16823 init = tsubst_expr (TREE_VALUE (t), argvec,
16824 tf_warning_or_error, NULL_TREE,
16825 /*integral_constant_expression_p=*/false);
16826 in_base_initializer = 0;
16831 init = build_tree_list (decl, init);
16832 TREE_CHAIN (init) = inits;
16840 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
16843 set_current_access_from_decl (tree decl)
16845 if (TREE_PRIVATE (decl))
16846 current_access_specifier = access_private_node;
16847 else if (TREE_PROTECTED (decl))
16848 current_access_specifier = access_protected_node;
16850 current_access_specifier = access_public_node;
16853 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
16854 is the instantiation (which should have been created with
16855 start_enum) and ARGS are the template arguments to use. */
16858 tsubst_enum (tree tag, tree newtag, tree args)
16862 for (e = TYPE_VALUES (tag); e; e = TREE_CHAIN (e))
16867 decl = TREE_VALUE (e);
16868 /* Note that in a template enum, the TREE_VALUE is the
16869 CONST_DECL, not the corresponding INTEGER_CST. */
16870 value = tsubst_expr (DECL_INITIAL (decl),
16871 args, tf_warning_or_error, NULL_TREE,
16872 /*integral_constant_expression_p=*/true);
16874 /* Give this enumeration constant the correct access. */
16875 set_current_access_from_decl (decl);
16877 /* Actually build the enumerator itself. */
16878 build_enumerator (DECL_NAME (decl), value, newtag);
16881 finish_enum (newtag);
16882 DECL_SOURCE_LOCATION (TYPE_NAME (newtag))
16883 = DECL_SOURCE_LOCATION (TYPE_NAME (tag));
16886 /* DECL is a FUNCTION_DECL that is a template specialization. Return
16887 its type -- but without substituting the innermost set of template
16888 arguments. So, innermost set of template parameters will appear in
16892 get_mostly_instantiated_function_type (tree decl)
16900 tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
16901 targs = DECL_TI_ARGS (decl);
16902 tparms = DECL_TEMPLATE_PARMS (tmpl);
16903 parm_depth = TMPL_PARMS_DEPTH (tparms);
16905 /* There should be as many levels of arguments as there are levels
16907 gcc_assert (parm_depth == TMPL_ARGS_DEPTH (targs));
16909 fn_type = TREE_TYPE (tmpl);
16911 if (parm_depth == 1)
16912 /* No substitution is necessary. */
16916 int i, save_access_control;
16919 /* Replace the innermost level of the TARGS with NULL_TREEs to
16920 let tsubst know not to substitute for those parameters. */
16921 partial_args = make_tree_vec (TREE_VEC_LENGTH (targs));
16922 for (i = 1; i < TMPL_ARGS_DEPTH (targs); ++i)
16923 SET_TMPL_ARGS_LEVEL (partial_args, i,
16924 TMPL_ARGS_LEVEL (targs, i));
16925 SET_TMPL_ARGS_LEVEL (partial_args,
16926 TMPL_ARGS_DEPTH (targs),
16927 make_tree_vec (DECL_NTPARMS (tmpl)));
16929 /* Disable access control as this function is used only during
16931 save_access_control = flag_access_control;
16932 flag_access_control = 0;
16934 ++processing_template_decl;
16935 /* Now, do the (partial) substitution to figure out the
16936 appropriate function type. */
16937 fn_type = tsubst (fn_type, partial_args, tf_error, NULL_TREE);
16938 --processing_template_decl;
16940 /* Substitute into the template parameters to obtain the real
16941 innermost set of parameters. This step is important if the
16942 innermost set of template parameters contains value
16943 parameters whose types depend on outer template parameters. */
16944 TREE_VEC_LENGTH (partial_args)--;
16945 tparms = tsubst_template_parms (tparms, partial_args, tf_error);
16947 flag_access_control = save_access_control;
16953 /* Return truthvalue if we're processing a template different from
16954 the last one involved in diagnostics. */
16956 problematic_instantiation_changed (void)
16958 return last_template_error_tick != tinst_level_tick;
16961 /* Remember current template involved in diagnostics. */
16963 record_last_problematic_instantiation (void)
16965 last_template_error_tick = tinst_level_tick;
16968 struct tinst_level *
16969 current_instantiation (void)
16971 return current_tinst_level;
16974 /* [temp.param] Check that template non-type parm TYPE is of an allowable
16975 type. Return zero for ok, nonzero for disallowed. Issue error and
16976 warning messages under control of COMPLAIN. */
16979 invalid_nontype_parm_type_p (tree type, tsubst_flags_t complain)
16981 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
16983 else if (POINTER_TYPE_P (type))
16985 else if (TYPE_PTR_TO_MEMBER_P (type))
16987 else if (TREE_CODE (type) == TEMPLATE_TYPE_PARM)
16989 else if (TREE_CODE (type) == TYPENAME_TYPE)
16992 if (complain & tf_error)
16993 error ("%q#T is not a valid type for a template constant parameter", type);
16997 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
16998 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
17001 dependent_type_p_r (tree type)
17007 A type is dependent if it is:
17009 -- a template parameter. Template template parameters are types
17010 for us (since TYPE_P holds true for them) so we handle
17012 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
17013 || TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM)
17015 /* -- a qualified-id with a nested-name-specifier which contains a
17016 class-name that names a dependent type or whose unqualified-id
17017 names a dependent type. */
17018 if (TREE_CODE (type) == TYPENAME_TYPE)
17020 /* -- a cv-qualified type where the cv-unqualified type is
17022 type = TYPE_MAIN_VARIANT (type);
17023 /* -- a compound type constructed from any dependent type. */
17024 if (TYPE_PTR_TO_MEMBER_P (type))
17025 return (dependent_type_p (TYPE_PTRMEM_CLASS_TYPE (type))
17026 || dependent_type_p (TYPE_PTRMEM_POINTED_TO_TYPE
17028 else if (TREE_CODE (type) == POINTER_TYPE
17029 || TREE_CODE (type) == REFERENCE_TYPE)
17030 return dependent_type_p (TREE_TYPE (type));
17031 else if (TREE_CODE (type) == FUNCTION_TYPE
17032 || TREE_CODE (type) == METHOD_TYPE)
17036 if (dependent_type_p (TREE_TYPE (type)))
17038 for (arg_type = TYPE_ARG_TYPES (type);
17040 arg_type = TREE_CHAIN (arg_type))
17041 if (dependent_type_p (TREE_VALUE (arg_type)))
17045 /* -- an array type constructed from any dependent type or whose
17046 size is specified by a constant expression that is
17047 value-dependent. */
17048 if (TREE_CODE (type) == ARRAY_TYPE)
17050 if (TYPE_DOMAIN (type)
17051 && dependent_type_p (TYPE_DOMAIN (type)))
17053 return dependent_type_p (TREE_TYPE (type));
17055 else if (TREE_CODE (type) == INTEGER_TYPE
17056 && !TREE_CONSTANT (TYPE_MAX_VALUE (type)))
17058 /* If this is the TYPE_DOMAIN of an array type, consider it
17059 dependent. We already checked for value-dependence in
17060 compute_array_index_type. */
17061 return type_dependent_expression_p (TYPE_MAX_VALUE (type));
17064 /* -- a template-id in which either the template name is a template
17066 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
17068 /* ... or any of the template arguments is a dependent type or
17069 an expression that is type-dependent or value-dependent. */
17070 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INFO (type)
17071 && (any_dependent_template_arguments_p
17072 (INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type)))))
17075 /* All TYPEOF_TYPEs and DECLTYPE_TYPEs are dependent; if the
17076 argument of the `typeof' expression is not type-dependent, then
17077 it should already been have resolved. */
17078 if (TREE_CODE (type) == TYPEOF_TYPE
17079 || TREE_CODE (type) == DECLTYPE_TYPE)
17082 /* A template argument pack is dependent if any of its packed
17084 if (TREE_CODE (type) == TYPE_ARGUMENT_PACK)
17086 tree args = ARGUMENT_PACK_ARGS (type);
17087 int i, len = TREE_VEC_LENGTH (args);
17088 for (i = 0; i < len; ++i)
17089 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
17093 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
17094 be template parameters. */
17095 if (TREE_CODE (type) == TYPE_PACK_EXPANSION)
17098 /* The standard does not specifically mention types that are local
17099 to template functions or local classes, but they should be
17100 considered dependent too. For example:
17102 template <int I> void f() {
17107 The size of `E' cannot be known until the value of `I' has been
17108 determined. Therefore, `E' must be considered dependent. */
17109 scope = TYPE_CONTEXT (type);
17110 if (scope && TYPE_P (scope))
17111 return dependent_type_p (scope);
17112 else if (scope && TREE_CODE (scope) == FUNCTION_DECL)
17113 return type_dependent_expression_p (scope);
17115 /* Other types are non-dependent. */
17119 /* Returns TRUE if TYPE is dependent, in the sense of
17120 [temp.dep.type]. */
17123 dependent_type_p (tree type)
17125 /* If there are no template parameters in scope, then there can't be
17126 any dependent types. */
17127 if (!processing_template_decl)
17129 /* If we are not processing a template, then nobody should be
17130 providing us with a dependent type. */
17132 gcc_assert (TREE_CODE (type) != TEMPLATE_TYPE_PARM || is_auto (type));
17136 /* If the type is NULL, we have not computed a type for the entity
17137 in question; in that case, the type is dependent. */
17141 /* Erroneous types can be considered non-dependent. */
17142 if (type == error_mark_node)
17145 /* If we have not already computed the appropriate value for TYPE,
17147 if (!TYPE_DEPENDENT_P_VALID (type))
17149 TYPE_DEPENDENT_P (type) = dependent_type_p_r (type);
17150 TYPE_DEPENDENT_P_VALID (type) = 1;
17153 return TYPE_DEPENDENT_P (type);
17156 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
17157 lookup. In other words, a dependent type that is not the current
17161 dependent_scope_p (tree scope)
17163 return (scope && TYPE_P (scope) && dependent_type_p (scope)
17164 && !currently_open_class (scope));
17167 /* Returns TRUE if EXPRESSION is dependent, according to CRITERION. */
17170 dependent_scope_ref_p (tree expression, bool criterion (tree))
17175 gcc_assert (TREE_CODE (expression) == SCOPE_REF);
17177 if (!TYPE_P (TREE_OPERAND (expression, 0)))
17180 scope = TREE_OPERAND (expression, 0);
17181 name = TREE_OPERAND (expression, 1);
17185 An id-expression is type-dependent if it contains a
17186 nested-name-specifier that contains a class-name that names a
17188 /* The suggested resolution to Core Issue 224 implies that if the
17189 qualifying type is the current class, then we must peek
17192 && currently_open_class (scope)
17193 && !criterion (name))
17195 if (dependent_type_p (scope))
17201 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
17202 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
17206 value_dependent_expression_p (tree expression)
17208 if (!processing_template_decl)
17211 /* A name declared with a dependent type. */
17212 if (DECL_P (expression) && type_dependent_expression_p (expression))
17215 switch (TREE_CODE (expression))
17217 case IDENTIFIER_NODE:
17218 /* A name that has not been looked up -- must be dependent. */
17221 case TEMPLATE_PARM_INDEX:
17222 /* A non-type template parm. */
17226 /* A non-type template parm. */
17227 if (DECL_TEMPLATE_PARM_P (expression))
17229 return value_dependent_expression_p (DECL_INITIAL (expression));
17232 /* A constant with integral or enumeration type and is initialized
17233 with an expression that is value-dependent. */
17234 if (DECL_INITIAL (expression)
17235 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (expression))
17236 && value_dependent_expression_p (DECL_INITIAL (expression)))
17240 case DYNAMIC_CAST_EXPR:
17241 case STATIC_CAST_EXPR:
17242 case CONST_CAST_EXPR:
17243 case REINTERPRET_CAST_EXPR:
17245 /* These expressions are value-dependent if the type to which
17246 the cast occurs is dependent or the expression being casted
17247 is value-dependent. */
17249 tree type = TREE_TYPE (expression);
17251 if (dependent_type_p (type))
17254 /* A functional cast has a list of operands. */
17255 expression = TREE_OPERAND (expression, 0);
17258 /* If there are no operands, it must be an expression such
17259 as "int()". This should not happen for aggregate types
17260 because it would form non-constant expressions. */
17261 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
17266 if (TREE_CODE (expression) == TREE_LIST)
17267 return any_value_dependent_elements_p (expression);
17269 return value_dependent_expression_p (expression);
17274 /* A `sizeof' expression is value-dependent if the operand is
17275 type-dependent or is a pack expansion. */
17276 expression = TREE_OPERAND (expression, 0);
17277 if (PACK_EXPANSION_P (expression))
17279 else if (TYPE_P (expression))
17280 return dependent_type_p (expression);
17281 return type_dependent_expression_p (expression);
17284 return dependent_scope_ref_p (expression, value_dependent_expression_p);
17286 case COMPONENT_REF:
17287 return (value_dependent_expression_p (TREE_OPERAND (expression, 0))
17288 || value_dependent_expression_p (TREE_OPERAND (expression, 1)));
17291 /* A CALL_EXPR may appear in a constant expression if it is a
17292 call to a builtin function, e.g., __builtin_constant_p. All
17293 such calls are value-dependent. */
17296 case NONTYPE_ARGUMENT_PACK:
17297 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
17298 is value-dependent. */
17300 tree values = ARGUMENT_PACK_ARGS (expression);
17301 int i, len = TREE_VEC_LENGTH (values);
17303 for (i = 0; i < len; ++i)
17304 if (value_dependent_expression_p (TREE_VEC_ELT (values, i)))
17312 tree type2 = TRAIT_EXPR_TYPE2 (expression);
17313 return (dependent_type_p (TRAIT_EXPR_TYPE1 (expression))
17314 || (type2 ? dependent_type_p (type2) : false));
17318 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
17319 || (value_dependent_expression_p (TREE_OPERAND (expression, 2))));
17322 /* A constant expression is value-dependent if any subexpression is
17323 value-dependent. */
17324 switch (TREE_CODE_CLASS (TREE_CODE (expression)))
17326 case tcc_reference:
17328 return (value_dependent_expression_p
17329 (TREE_OPERAND (expression, 0)));
17331 case tcc_comparison:
17333 return ((value_dependent_expression_p
17334 (TREE_OPERAND (expression, 0)))
17335 || (value_dependent_expression_p
17336 (TREE_OPERAND (expression, 1))));
17338 case tcc_expression:
17342 for (i = 0; i < TREE_OPERAND_LENGTH (expression); ++i)
17343 /* In some cases, some of the operands may be missing.
17344 (For example, in the case of PREDECREMENT_EXPR, the
17345 amount to increment by may be missing.) That doesn't
17346 make the expression dependent. */
17347 if (TREE_OPERAND (expression, i)
17348 && (value_dependent_expression_p
17349 (TREE_OPERAND (expression, i))))
17359 /* The expression is not value-dependent. */
17363 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
17364 [temp.dep.expr]. */
17367 type_dependent_expression_p (tree expression)
17369 if (!processing_template_decl)
17372 if (expression == error_mark_node)
17375 /* An unresolved name is always dependent. */
17376 if (TREE_CODE (expression) == IDENTIFIER_NODE
17377 || TREE_CODE (expression) == USING_DECL)
17380 /* Some expression forms are never type-dependent. */
17381 if (TREE_CODE (expression) == PSEUDO_DTOR_EXPR
17382 || TREE_CODE (expression) == SIZEOF_EXPR
17383 || TREE_CODE (expression) == ALIGNOF_EXPR
17384 || TREE_CODE (expression) == TRAIT_EXPR
17385 || TREE_CODE (expression) == TYPEID_EXPR
17386 || TREE_CODE (expression) == DELETE_EXPR
17387 || TREE_CODE (expression) == VEC_DELETE_EXPR
17388 || TREE_CODE (expression) == THROW_EXPR)
17391 /* The types of these expressions depends only on the type to which
17392 the cast occurs. */
17393 if (TREE_CODE (expression) == DYNAMIC_CAST_EXPR
17394 || TREE_CODE (expression) == STATIC_CAST_EXPR
17395 || TREE_CODE (expression) == CONST_CAST_EXPR
17396 || TREE_CODE (expression) == REINTERPRET_CAST_EXPR
17397 || TREE_CODE (expression) == CAST_EXPR)
17398 return dependent_type_p (TREE_TYPE (expression));
17400 /* The types of these expressions depends only on the type created
17401 by the expression. */
17402 if (TREE_CODE (expression) == NEW_EXPR
17403 || TREE_CODE (expression) == VEC_NEW_EXPR)
17405 /* For NEW_EXPR tree nodes created inside a template, either
17406 the object type itself or a TREE_LIST may appear as the
17408 tree type = TREE_OPERAND (expression, 1);
17409 if (TREE_CODE (type) == TREE_LIST)
17410 /* This is an array type. We need to check array dimensions
17412 return dependent_type_p (TREE_VALUE (TREE_PURPOSE (type)))
17413 || value_dependent_expression_p
17414 (TREE_OPERAND (TREE_VALUE (type), 1));
17416 return dependent_type_p (type);
17419 if (TREE_CODE (expression) == SCOPE_REF
17420 && dependent_scope_ref_p (expression,
17421 type_dependent_expression_p))
17424 if (TREE_CODE (expression) == FUNCTION_DECL
17425 && DECL_LANG_SPECIFIC (expression)
17426 && DECL_TEMPLATE_INFO (expression)
17427 && (any_dependent_template_arguments_p
17428 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (expression)))))
17431 if (TREE_CODE (expression) == TEMPLATE_DECL
17432 && !DECL_TEMPLATE_TEMPLATE_PARM_P (expression))
17435 if (TREE_CODE (expression) == STMT_EXPR)
17436 expression = stmt_expr_value_expr (expression);
17438 if (BRACE_ENCLOSED_INITIALIZER_P (expression))
17443 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), i, elt)
17445 if (type_dependent_expression_p (elt))
17451 if (TREE_TYPE (expression) == unknown_type_node)
17453 if (TREE_CODE (expression) == ADDR_EXPR)
17454 return type_dependent_expression_p (TREE_OPERAND (expression, 0));
17455 if (TREE_CODE (expression) == COMPONENT_REF
17456 || TREE_CODE (expression) == OFFSET_REF)
17458 if (type_dependent_expression_p (TREE_OPERAND (expression, 0)))
17460 expression = TREE_OPERAND (expression, 1);
17461 if (TREE_CODE (expression) == IDENTIFIER_NODE)
17464 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
17465 if (TREE_CODE (expression) == SCOPE_REF)
17468 if (TREE_CODE (expression) == BASELINK)
17469 expression = BASELINK_FUNCTIONS (expression);
17471 if (TREE_CODE (expression) == TEMPLATE_ID_EXPR)
17473 if (any_dependent_template_arguments_p
17474 (TREE_OPERAND (expression, 1)))
17476 expression = TREE_OPERAND (expression, 0);
17478 gcc_assert (TREE_CODE (expression) == OVERLOAD
17479 || TREE_CODE (expression) == FUNCTION_DECL);
17483 if (type_dependent_expression_p (OVL_CURRENT (expression)))
17485 expression = OVL_NEXT (expression);
17490 gcc_assert (TREE_CODE (expression) != TYPE_DECL);
17492 return (dependent_type_p (TREE_TYPE (expression)));
17495 /* Like type_dependent_expression_p, but it also works while not processing
17496 a template definition, i.e. during substitution or mangling. */
17499 type_dependent_expression_p_push (tree expr)
17502 ++processing_template_decl;
17503 b = type_dependent_expression_p (expr);
17504 --processing_template_decl;
17508 /* Returns TRUE if ARGS contains a type-dependent expression. */
17511 any_type_dependent_arguments_p (const VEC(tree,gc) *args)
17516 for (i = 0; VEC_iterate (tree, args, i, arg); ++i)
17518 if (type_dependent_expression_p (arg))
17524 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
17525 expressions) contains any value-dependent expressions. */
17528 any_value_dependent_elements_p (const_tree list)
17530 for (; list; list = TREE_CHAIN (list))
17531 if (value_dependent_expression_p (TREE_VALUE (list)))
17537 /* Returns TRUE if the ARG (a template argument) is dependent. */
17540 dependent_template_arg_p (tree arg)
17542 if (!processing_template_decl)
17545 if (TREE_CODE (arg) == TEMPLATE_DECL
17546 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
17547 return dependent_template_p (arg);
17548 else if (ARGUMENT_PACK_P (arg))
17550 tree args = ARGUMENT_PACK_ARGS (arg);
17551 int i, len = TREE_VEC_LENGTH (args);
17552 for (i = 0; i < len; ++i)
17554 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
17560 else if (TYPE_P (arg))
17561 return dependent_type_p (arg);
17563 return (type_dependent_expression_p (arg)
17564 || value_dependent_expression_p (arg));
17567 /* Returns true if ARGS (a collection of template arguments) contains
17568 any types that require structural equality testing. */
17571 any_template_arguments_need_structural_equality_p (tree args)
17578 if (args == error_mark_node)
17581 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
17583 tree level = TMPL_ARGS_LEVEL (args, i + 1);
17584 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
17586 tree arg = TREE_VEC_ELT (level, j);
17587 tree packed_args = NULL_TREE;
17590 if (ARGUMENT_PACK_P (arg))
17592 /* Look inside the argument pack. */
17593 packed_args = ARGUMENT_PACK_ARGS (arg);
17594 len = TREE_VEC_LENGTH (packed_args);
17597 for (k = 0; k < len; ++k)
17600 arg = TREE_VEC_ELT (packed_args, k);
17602 if (error_operand_p (arg))
17604 else if (TREE_CODE (arg) == TEMPLATE_DECL
17605 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
17607 else if (TYPE_P (arg) && TYPE_STRUCTURAL_EQUALITY_P (arg))
17609 else if (!TYPE_P (arg) && TREE_TYPE (arg)
17610 && TYPE_STRUCTURAL_EQUALITY_P (TREE_TYPE (arg)))
17619 /* Returns true if ARGS (a collection of template arguments) contains
17620 any dependent arguments. */
17623 any_dependent_template_arguments_p (const_tree args)
17630 if (args == error_mark_node)
17633 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
17635 const_tree level = TMPL_ARGS_LEVEL (args, i + 1);
17636 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
17637 if (dependent_template_arg_p (TREE_VEC_ELT (level, j)))
17644 /* Returns TRUE if the template TMPL is dependent. */
17647 dependent_template_p (tree tmpl)
17649 if (TREE_CODE (tmpl) == OVERLOAD)
17653 if (dependent_template_p (OVL_FUNCTION (tmpl)))
17655 tmpl = OVL_CHAIN (tmpl);
17660 /* Template template parameters are dependent. */
17661 if (DECL_TEMPLATE_TEMPLATE_PARM_P (tmpl)
17662 || TREE_CODE (tmpl) == TEMPLATE_TEMPLATE_PARM)
17664 /* So are names that have not been looked up. */
17665 if (TREE_CODE (tmpl) == SCOPE_REF
17666 || TREE_CODE (tmpl) == IDENTIFIER_NODE)
17668 /* So are member templates of dependent classes. */
17669 if (TYPE_P (CP_DECL_CONTEXT (tmpl)))
17670 return dependent_type_p (DECL_CONTEXT (tmpl));
17674 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
17677 dependent_template_id_p (tree tmpl, tree args)
17679 return (dependent_template_p (tmpl)
17680 || any_dependent_template_arguments_p (args));
17683 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
17687 dependent_omp_for_p (tree declv, tree initv, tree condv, tree incrv)
17691 if (!processing_template_decl)
17694 for (i = 0; i < TREE_VEC_LENGTH (declv); i++)
17696 tree decl = TREE_VEC_ELT (declv, i);
17697 tree init = TREE_VEC_ELT (initv, i);
17698 tree cond = TREE_VEC_ELT (condv, i);
17699 tree incr = TREE_VEC_ELT (incrv, i);
17701 if (type_dependent_expression_p (decl))
17704 if (init && type_dependent_expression_p (init))
17707 if (type_dependent_expression_p (cond))
17710 if (COMPARISON_CLASS_P (cond)
17711 && (type_dependent_expression_p (TREE_OPERAND (cond, 0))
17712 || type_dependent_expression_p (TREE_OPERAND (cond, 1))))
17715 if (TREE_CODE (incr) == MODOP_EXPR)
17717 if (type_dependent_expression_p (TREE_OPERAND (incr, 0))
17718 || type_dependent_expression_p (TREE_OPERAND (incr, 2)))
17721 else if (type_dependent_expression_p (incr))
17723 else if (TREE_CODE (incr) == MODIFY_EXPR)
17725 if (type_dependent_expression_p (TREE_OPERAND (incr, 0)))
17727 else if (BINARY_CLASS_P (TREE_OPERAND (incr, 1)))
17729 tree t = TREE_OPERAND (incr, 1);
17730 if (type_dependent_expression_p (TREE_OPERAND (t, 0))
17731 || type_dependent_expression_p (TREE_OPERAND (t, 1)))
17740 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
17741 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
17742 no such TYPE can be found. Note that this function peers inside
17743 uninstantiated templates and therefore should be used only in
17744 extremely limited situations. ONLY_CURRENT_P restricts this
17745 peering to the currently open classes hierarchy (which is required
17746 when comparing types). */
17749 resolve_typename_type (tree type, bool only_current_p)
17758 gcc_assert (TREE_CODE (type) == TYPENAME_TYPE);
17760 scope = TYPE_CONTEXT (type);
17761 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
17762 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
17763 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
17764 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
17765 identifier of the TYPENAME_TYPE anymore.
17766 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
17767 TYPENAME_TYPE instead, we avoid messing up with a possible
17768 typedef variant case. */
17769 name = TYPE_IDENTIFIER (TYPE_MAIN_VARIANT (type));
17771 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
17772 it first before we can figure out what NAME refers to. */
17773 if (TREE_CODE (scope) == TYPENAME_TYPE)
17774 scope = resolve_typename_type (scope, only_current_p);
17775 /* If we don't know what SCOPE refers to, then we cannot resolve the
17777 if (TREE_CODE (scope) == TYPENAME_TYPE)
17779 /* If the SCOPE is a template type parameter, we have no way of
17780 resolving the name. */
17781 if (TREE_CODE (scope) == TEMPLATE_TYPE_PARM)
17783 /* If the SCOPE is not the current instantiation, there's no reason
17784 to look inside it. */
17785 if (only_current_p && !currently_open_class (scope))
17787 /* If this is a typedef, we don't want to look inside (c++/11987). */
17788 if (typedef_variant_p (type))
17790 /* If SCOPE isn't the template itself, it will not have a valid
17791 TYPE_FIELDS list. */
17792 if (same_type_p (scope, CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope)))
17793 /* scope is either the template itself or a compatible instantiation
17794 like X<T>, so look up the name in the original template. */
17795 scope = CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope);
17797 /* scope is a partial instantiation, so we can't do the lookup or we
17798 will lose the template arguments. */
17800 /* Enter the SCOPE so that name lookup will be resolved as if we
17801 were in the class definition. In particular, SCOPE will no
17802 longer be considered a dependent type. */
17803 pushed_scope = push_scope (scope);
17804 /* Look up the declaration. */
17805 decl = lookup_member (scope, name, /*protect=*/0, /*want_type=*/true);
17807 result = NULL_TREE;
17809 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
17810 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
17813 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == IDENTIFIER_NODE
17814 && TREE_CODE (decl) == TYPE_DECL)
17816 result = TREE_TYPE (decl);
17817 if (result == error_mark_node)
17818 result = NULL_TREE;
17820 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == TEMPLATE_ID_EXPR
17821 && DECL_CLASS_TEMPLATE_P (decl))
17825 /* Obtain the template and the arguments. */
17826 tmpl = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 0);
17827 args = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 1);
17828 /* Instantiate the template. */
17829 result = lookup_template_class (tmpl, args, NULL_TREE, NULL_TREE,
17830 /*entering_scope=*/0,
17831 tf_error | tf_user);
17832 if (result == error_mark_node)
17833 result = NULL_TREE;
17836 /* Leave the SCOPE. */
17838 pop_scope (pushed_scope);
17840 /* If we failed to resolve it, return the original typename. */
17844 /* If lookup found a typename type, resolve that too. */
17845 if (TREE_CODE (result) == TYPENAME_TYPE && !TYPENAME_IS_RESOLVING_P (result))
17847 /* Ill-formed programs can cause infinite recursion here, so we
17848 must catch that. */
17849 TYPENAME_IS_RESOLVING_P (type) = 1;
17850 result = resolve_typename_type (result, only_current_p);
17851 TYPENAME_IS_RESOLVING_P (type) = 0;
17854 /* Qualify the resulting type. */
17855 quals = cp_type_quals (type);
17857 result = cp_build_qualified_type (result, cp_type_quals (result) | quals);
17862 /* EXPR is an expression which is not type-dependent. Return a proxy
17863 for EXPR that can be used to compute the types of larger
17864 expressions containing EXPR. */
17867 build_non_dependent_expr (tree expr)
17871 /* Preserve null pointer constants so that the type of things like
17872 "p == 0" where "p" is a pointer can be determined. */
17873 if (null_ptr_cst_p (expr))
17875 /* Preserve OVERLOADs; the functions must be available to resolve
17878 if (TREE_CODE (inner_expr) == STMT_EXPR)
17879 inner_expr = stmt_expr_value_expr (inner_expr);
17880 if (TREE_CODE (inner_expr) == ADDR_EXPR)
17881 inner_expr = TREE_OPERAND (inner_expr, 0);
17882 if (TREE_CODE (inner_expr) == COMPONENT_REF)
17883 inner_expr = TREE_OPERAND (inner_expr, 1);
17884 if (is_overloaded_fn (inner_expr)
17885 || TREE_CODE (inner_expr) == OFFSET_REF)
17887 /* There is no need to return a proxy for a variable. */
17888 if (TREE_CODE (expr) == VAR_DECL)
17890 /* Preserve string constants; conversions from string constants to
17891 "char *" are allowed, even though normally a "const char *"
17892 cannot be used to initialize a "char *". */
17893 if (TREE_CODE (expr) == STRING_CST)
17895 /* Preserve arithmetic constants, as an optimization -- there is no
17896 reason to create a new node. */
17897 if (TREE_CODE (expr) == INTEGER_CST || TREE_CODE (expr) == REAL_CST)
17899 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
17900 There is at least one place where we want to know that a
17901 particular expression is a throw-expression: when checking a ?:
17902 expression, there are special rules if the second or third
17903 argument is a throw-expression. */
17904 if (TREE_CODE (expr) == THROW_EXPR)
17907 if (TREE_CODE (expr) == COND_EXPR)
17908 return build3 (COND_EXPR,
17910 TREE_OPERAND (expr, 0),
17911 (TREE_OPERAND (expr, 1)
17912 ? build_non_dependent_expr (TREE_OPERAND (expr, 1))
17913 : build_non_dependent_expr (TREE_OPERAND (expr, 0))),
17914 build_non_dependent_expr (TREE_OPERAND (expr, 2)));
17915 if (TREE_CODE (expr) == COMPOUND_EXPR
17916 && !COMPOUND_EXPR_OVERLOADED (expr))
17917 return build2 (COMPOUND_EXPR,
17919 TREE_OPERAND (expr, 0),
17920 build_non_dependent_expr (TREE_OPERAND (expr, 1)));
17922 /* If the type is unknown, it can't really be non-dependent */
17923 gcc_assert (TREE_TYPE (expr) != unknown_type_node);
17925 /* Otherwise, build a NON_DEPENDENT_EXPR.
17927 REFERENCE_TYPEs are not stripped for expressions in templates
17928 because doing so would play havoc with mangling. Consider, for
17931 template <typename T> void f<T& g>() { g(); }
17933 In the body of "f", the expression for "g" will have
17934 REFERENCE_TYPE, even though the standard says that it should
17935 not. The reason is that we must preserve the syntactic form of
17936 the expression so that mangling (say) "f<g>" inside the body of
17937 "f" works out correctly. Therefore, the REFERENCE_TYPE is
17939 return build1 (NON_DEPENDENT_EXPR, non_reference (TREE_TYPE (expr)), expr);
17942 /* ARGS is a vector of expressions as arguments to a function call.
17943 Replace the arguments with equivalent non-dependent expressions.
17944 This modifies ARGS in place. */
17947 make_args_non_dependent (VEC(tree,gc) *args)
17952 for (ix = 0; VEC_iterate (tree, args, ix, arg); ++ix)
17954 tree newarg = build_non_dependent_expr (arg);
17956 VEC_replace (tree, args, ix, newarg);
17960 /* Returns a type which represents 'auto'. We use a TEMPLATE_TYPE_PARM
17961 with a level one deeper than the actual template parms. */
17966 tree au = cxx_make_type (TEMPLATE_TYPE_PARM);
17967 TYPE_NAME (au) = build_decl (BUILTINS_LOCATION,
17968 TYPE_DECL, get_identifier ("auto"), au);
17969 TYPE_STUB_DECL (au) = TYPE_NAME (au);
17970 TEMPLATE_TYPE_PARM_INDEX (au) = build_template_parm_index
17971 (0, processing_template_decl + 1, processing_template_decl + 1,
17972 TYPE_NAME (au), NULL_TREE);
17973 TYPE_CANONICAL (au) = canonical_type_parameter (au);
17974 DECL_ARTIFICIAL (TYPE_NAME (au)) = 1;
17975 SET_DECL_TEMPLATE_PARM_P (TYPE_NAME (au));
17980 /* Given type ARG, return std::initializer_list<ARG>. */
17985 tree std_init_list = namespace_binding
17986 (get_identifier ("initializer_list"), std_node);
17988 if (!std_init_list || !DECL_CLASS_TEMPLATE_P (std_init_list))
17990 error ("deducing from brace-enclosed initializer list requires "
17991 "#include <initializer_list>");
17992 return error_mark_node;
17994 argvec = make_tree_vec (1);
17995 TREE_VEC_ELT (argvec, 0) = arg;
17996 return lookup_template_class (std_init_list, argvec, NULL_TREE,
17997 NULL_TREE, 0, tf_warning_or_error);
18000 /* Replace auto in TYPE with std::initializer_list<auto>. */
18003 listify_autos (tree type, tree auto_node)
18005 tree init_auto = listify (auto_node);
18006 tree argvec = make_tree_vec (1);
18007 TREE_VEC_ELT (argvec, 0) = init_auto;
18008 if (processing_template_decl)
18009 argvec = add_to_template_args (current_template_args (), argvec);
18010 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
18013 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
18014 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
18017 do_auto_deduction (tree type, tree init, tree auto_node)
18019 tree parms, tparms, targs;
18023 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
18024 with either a new invented type template parameter U or, if the
18025 initializer is a braced-init-list (8.5.4), with
18026 std::initializer_list<U>. */
18027 if (BRACE_ENCLOSED_INITIALIZER_P (init))
18028 type = listify_autos (type, auto_node);
18030 parms = build_tree_list (NULL_TREE, type);
18032 tparms = make_tree_vec (1);
18033 targs = make_tree_vec (1);
18034 TREE_VEC_ELT (tparms, 0)
18035 = build_tree_list (NULL_TREE, TYPE_NAME (auto_node));
18036 val = type_unification_real (tparms, targs, parms, args, 1, 0,
18037 DEDUCE_CALL, LOOKUP_NORMAL);
18040 error ("unable to deduce %qT from %qE", type, init);
18041 return error_mark_node;
18044 /* If the list of declarators contains more than one declarator, the type
18045 of each declared variable is determined as described above. If the
18046 type deduced for the template parameter U is not the same in each
18047 deduction, the program is ill-formed. */
18048 if (TREE_TYPE (auto_node)
18049 && !same_type_p (TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0)))
18051 error ("inconsistent deduction for %qT: %qT and then %qT",
18052 auto_node, TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0));
18053 return error_mark_node;
18055 TREE_TYPE (auto_node) = TREE_VEC_ELT (targs, 0);
18057 if (processing_template_decl)
18058 targs = add_to_template_args (current_template_args (), targs);
18059 return tsubst (type, targs, tf_warning_or_error, NULL_TREE);
18062 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
18066 splice_late_return_type (tree type, tree late_return_type)
18070 if (late_return_type == NULL_TREE)
18072 argvec = make_tree_vec (1);
18073 TREE_VEC_ELT (argvec, 0) = late_return_type;
18074 if (processing_template_decl)
18075 argvec = add_to_template_args (current_template_args (), argvec);
18076 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
18079 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto'. */
18082 is_auto (const_tree type)
18084 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
18085 && TYPE_IDENTIFIER (type) == get_identifier ("auto"))
18091 /* Returns true iff TYPE contains a use of 'auto'. Since auto can only
18092 appear as a type-specifier for the declaration in question, we don't
18093 have to look through the whole type. */
18096 type_uses_auto (tree type)
18098 enum tree_code code;
18099 if (is_auto (type))
18102 code = TREE_CODE (type);
18104 if (code == POINTER_TYPE || code == REFERENCE_TYPE
18105 || code == OFFSET_TYPE || code == FUNCTION_TYPE
18106 || code == METHOD_TYPE || code == ARRAY_TYPE)
18107 return type_uses_auto (TREE_TYPE (type));
18109 if (TYPE_PTRMEMFUNC_P (type))
18110 return type_uses_auto (TREE_TYPE (TREE_TYPE
18111 (TYPE_PTRMEMFUNC_FN_TYPE (type))));
18116 /* For a given template T, return the vector of typedefs referenced
18117 in T for which access check is needed at T instantiation time.
18118 T is either a FUNCTION_DECL or a RECORD_TYPE.
18119 Those typedefs were added to T by the function
18120 append_type_to_template_for_access_check. */
18122 VEC(qualified_typedef_usage_t,gc)*
18123 get_types_needing_access_check (tree t)
18126 VEC(qualified_typedef_usage_t,gc) *result = NULL;
18128 if (!t || t == error_mark_node)
18131 if (!(ti = get_template_info (t)))
18134 if (CLASS_TYPE_P (t)
18135 || TREE_CODE (t) == FUNCTION_DECL)
18137 if (!TI_TEMPLATE (ti))
18140 result = TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti);
18146 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
18147 tied to T. That list of typedefs will be access checked at
18148 T instantiation time.
18149 T is either a FUNCTION_DECL or a RECORD_TYPE.
18150 TYPE_DECL is a TYPE_DECL node representing a typedef.
18151 SCOPE is the scope through which TYPE_DECL is accessed.
18152 LOCATION is the location of the usage point of TYPE_DECL.
18154 This function is a subroutine of
18155 append_type_to_template_for_access_check. */
18158 append_type_to_template_for_access_check_1 (tree t,
18161 location_t location)
18163 qualified_typedef_usage_t typedef_usage;
18166 if (!t || t == error_mark_node)
18169 gcc_assert ((TREE_CODE (t) == FUNCTION_DECL
18170 || CLASS_TYPE_P (t))
18172 && TREE_CODE (type_decl) == TYPE_DECL
18175 if (!(ti = get_template_info (t)))
18178 gcc_assert (TI_TEMPLATE (ti));
18180 typedef_usage.typedef_decl = type_decl;
18181 typedef_usage.context = scope;
18182 typedef_usage.locus = location;
18184 VEC_safe_push (qualified_typedef_usage_t, gc,
18185 TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti),
18189 /* Append TYPE_DECL to the template TEMPL.
18190 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
18191 At TEMPL instanciation time, TYPE_DECL will be checked to see
18192 if it can be accessed through SCOPE.
18193 LOCATION is the location of the usage point of TYPE_DECL.
18195 e.g. consider the following code snippet:
18202 template<class U> struct S
18204 C::myint mi; // <-- usage point of the typedef C::myint
18209 At S<char> instantiation time, we need to check the access of C::myint
18210 In other words, we need to check the access of the myint typedef through
18211 the C scope. For that purpose, this function will add the myint typedef
18212 and the scope C through which its being accessed to a list of typedefs
18213 tied to the template S. That list will be walked at template instantiation
18214 time and access check performed on each typedefs it contains.
18215 Note that this particular code snippet should yield an error because
18216 myint is private to C. */
18219 append_type_to_template_for_access_check (tree templ,
18222 location_t location)
18224 qualified_typedef_usage_t *iter;
18227 gcc_assert (type_decl && (TREE_CODE (type_decl) == TYPE_DECL));
18229 /* Make sure we don't append the type to the template twice. */
18231 VEC_iterate (qualified_typedef_usage_t,
18232 get_types_needing_access_check (templ),
18235 if (iter->typedef_decl == type_decl && scope == iter->context)
18238 append_type_to_template_for_access_check_1 (templ, type_decl,
18242 /* Set up the hash tables for template instantiations. */
18245 init_template_processing (void)
18247 decl_specializations = htab_create_ggc (37,
18248 hash_specialization,
18249 eq_specializations,
18251 type_specializations = htab_create_ggc (37,
18252 hash_specialization,
18253 eq_specializations,
18257 #include "gt-cp-pt.h"