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 candidate FNS in an error message. */
1652 print_candidates (tree fns)
1657 const char *str = "candidates are:";
1659 if (is_overloaded_fn (fns))
1661 for (f = fns; f; f = OVL_NEXT (f))
1663 error ("%s %+#D", str, OVL_CURRENT (f));
1667 else for (fn = fns; fn != NULL_TREE; fn = TREE_CHAIN (fn))
1669 for (f = TREE_VALUE (fn); f; f = OVL_NEXT (f))
1670 error ("%s %+#D", str, OVL_CURRENT (f));
1675 /* Returns the template (one of the functions given by TEMPLATE_ID)
1676 which can be specialized to match the indicated DECL with the
1677 explicit template args given in TEMPLATE_ID. The DECL may be
1678 NULL_TREE if none is available. In that case, the functions in
1679 TEMPLATE_ID are non-members.
1681 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1682 specialization of a member template.
1684 The TEMPLATE_COUNT is the number of references to qualifying
1685 template classes that appeared in the name of the function. See
1686 check_explicit_specialization for a more accurate description.
1688 TSK indicates what kind of template declaration (if any) is being
1689 declared. TSK_TEMPLATE indicates that the declaration given by
1690 DECL, though a FUNCTION_DECL, has template parameters, and is
1691 therefore a template function.
1693 The template args (those explicitly specified and those deduced)
1694 are output in a newly created vector *TARGS_OUT.
1696 If it is impossible to determine the result, an error message is
1697 issued. The error_mark_node is returned to indicate failure. */
1700 determine_specialization (tree template_id,
1703 int need_member_template,
1709 tree explicit_targs;
1710 tree candidates = NULL_TREE;
1711 /* A TREE_LIST of templates of which DECL may be a specialization.
1712 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1713 corresponding TREE_PURPOSE is the set of template arguments that,
1714 when used to instantiate the template, would produce a function
1715 with the signature of DECL. */
1716 tree templates = NULL_TREE;
1718 struct cp_binding_level *b;
1720 *targs_out = NULL_TREE;
1722 if (template_id == error_mark_node || decl == error_mark_node)
1723 return error_mark_node;
1725 fns = TREE_OPERAND (template_id, 0);
1726 explicit_targs = TREE_OPERAND (template_id, 1);
1728 if (fns == error_mark_node)
1729 return error_mark_node;
1731 /* Check for baselinks. */
1732 if (BASELINK_P (fns))
1733 fns = BASELINK_FUNCTIONS (fns);
1735 if (!is_overloaded_fn (fns))
1737 error ("%qD is not a function template", fns);
1738 return error_mark_node;
1741 /* Count the number of template headers specified for this
1744 for (b = current_binding_level;
1745 b->kind == sk_template_parms;
1749 for (; fns; fns = OVL_NEXT (fns))
1751 tree fn = OVL_CURRENT (fns);
1753 if (TREE_CODE (fn) == TEMPLATE_DECL)
1755 tree decl_arg_types;
1758 /* In case of explicit specialization, we need to check if
1759 the number of template headers appearing in the specialization
1760 is correct. This is usually done in check_explicit_specialization,
1761 but the check done there cannot be exhaustive when specializing
1762 member functions. Consider the following code:
1764 template <> void A<int>::f(int);
1765 template <> template <> void A<int>::f(int);
1767 Assuming that A<int> is not itself an explicit specialization
1768 already, the first line specializes "f" which is a non-template
1769 member function, whilst the second line specializes "f" which
1770 is a template member function. So both lines are syntactically
1771 correct, and check_explicit_specialization does not reject
1774 Here, we can do better, as we are matching the specialization
1775 against the declarations. We count the number of template
1776 headers, and we check if they match TEMPLATE_COUNT + 1
1777 (TEMPLATE_COUNT is the number of qualifying template classes,
1778 plus there must be another header for the member template
1781 Notice that if header_count is zero, this is not a
1782 specialization but rather a template instantiation, so there
1783 is no check we can perform here. */
1784 if (header_count && header_count != template_count + 1)
1787 /* Check that the number of template arguments at the
1788 innermost level for DECL is the same as for FN. */
1789 if (current_binding_level->kind == sk_template_parms
1790 && !current_binding_level->explicit_spec_p
1791 && (TREE_VEC_LENGTH (DECL_INNERMOST_TEMPLATE_PARMS (fn))
1792 != TREE_VEC_LENGTH (INNERMOST_TEMPLATE_PARMS
1793 (current_template_parms))))
1796 /* DECL might be a specialization of FN. */
1797 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1798 fn_arg_types = TYPE_ARG_TYPES (TREE_TYPE (fn));
1800 /* For a non-static member function, we need to make sure
1801 that the const qualification is the same. Since
1802 get_bindings does not try to merge the "this" parameter,
1803 we must do the comparison explicitly. */
1804 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
1805 && !same_type_p (TREE_VALUE (fn_arg_types),
1806 TREE_VALUE (decl_arg_types)))
1809 /* Skip the "this" parameter and, for constructors of
1810 classes with virtual bases, the VTT parameter. A
1811 full specialization of a constructor will have a VTT
1812 parameter, but a template never will. */
1814 = skip_artificial_parms_for (decl, decl_arg_types);
1816 = skip_artificial_parms_for (fn, fn_arg_types);
1818 /* Check that the number of function parameters matches.
1820 template <class T> void f(int i = 0);
1821 template <> void f<int>();
1822 The specialization f<int> is invalid but is not caught
1823 by get_bindings below. */
1824 if (list_length (fn_arg_types) != list_length (decl_arg_types))
1827 /* Function templates cannot be specializations; there are
1828 no partial specializations of functions. Therefore, if
1829 the type of DECL does not match FN, there is no
1831 if (tsk == tsk_template)
1833 if (compparms (fn_arg_types, decl_arg_types))
1834 candidates = tree_cons (NULL_TREE, fn, candidates);
1838 /* See whether this function might be a specialization of this
1840 targs = get_bindings (fn, decl, explicit_targs, /*check_ret=*/true);
1843 /* We cannot deduce template arguments that when used to
1844 specialize TMPL will produce DECL. */
1847 /* Save this template, and the arguments deduced. */
1848 templates = tree_cons (targs, fn, templates);
1850 else if (need_member_template)
1851 /* FN is an ordinary member function, and we need a
1852 specialization of a member template. */
1854 else if (TREE_CODE (fn) != FUNCTION_DECL)
1855 /* We can get IDENTIFIER_NODEs here in certain erroneous
1858 else if (!DECL_FUNCTION_MEMBER_P (fn))
1859 /* This is just an ordinary non-member function. Nothing can
1860 be a specialization of that. */
1862 else if (DECL_ARTIFICIAL (fn))
1863 /* Cannot specialize functions that are created implicitly. */
1867 tree decl_arg_types;
1869 /* This is an ordinary member function. However, since
1870 we're here, we can assume it's enclosing class is a
1871 template class. For example,
1873 template <typename T> struct S { void f(); };
1874 template <> void S<int>::f() {}
1876 Here, S<int>::f is a non-template, but S<int> is a
1877 template class. If FN has the same type as DECL, we
1878 might be in business. */
1880 if (!DECL_TEMPLATE_INFO (fn))
1881 /* Its enclosing class is an explicit specialization
1882 of a template class. This is not a candidate. */
1885 if (!same_type_p (TREE_TYPE (TREE_TYPE (decl)),
1886 TREE_TYPE (TREE_TYPE (fn))))
1887 /* The return types differ. */
1890 /* Adjust the type of DECL in case FN is a static member. */
1891 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1892 if (DECL_STATIC_FUNCTION_P (fn)
1893 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1894 decl_arg_types = TREE_CHAIN (decl_arg_types);
1896 if (compparms (TYPE_ARG_TYPES (TREE_TYPE (fn)),
1899 candidates = tree_cons (NULL_TREE, fn, candidates);
1903 if (templates && TREE_CHAIN (templates))
1909 It is possible for a specialization with a given function
1910 signature to be instantiated from more than one function
1911 template. In such cases, explicit specification of the
1912 template arguments must be used to uniquely identify the
1913 function template specialization being specialized.
1915 Note that here, there's no suggestion that we're supposed to
1916 determine which of the candidate templates is most
1917 specialized. However, we, also have:
1921 Partial ordering of overloaded function template
1922 declarations is used in the following contexts to select
1923 the function template to which a function template
1924 specialization refers:
1926 -- when an explicit specialization refers to a function
1929 So, we do use the partial ordering rules, at least for now.
1930 This extension can only serve to make invalid programs valid,
1931 so it's safe. And, there is strong anecdotal evidence that
1932 the committee intended the partial ordering rules to apply;
1933 the EDG front end has that behavior, and John Spicer claims
1934 that the committee simply forgot to delete the wording in
1935 [temp.expl.spec]. */
1936 tree tmpl = most_specialized_instantiation (templates);
1937 if (tmpl != error_mark_node)
1940 TREE_CHAIN (templates) = NULL_TREE;
1944 if (templates == NULL_TREE && candidates == NULL_TREE)
1946 error ("template-id %qD for %q+D does not match any template "
1947 "declaration", template_id, decl);
1948 return error_mark_node;
1950 else if ((templates && TREE_CHAIN (templates))
1951 || (candidates && TREE_CHAIN (candidates))
1952 || (templates && candidates))
1954 error ("ambiguous template specialization %qD for %q+D",
1956 candidates = chainon (candidates, templates);
1957 print_candidates (candidates);
1958 return error_mark_node;
1961 /* We have one, and exactly one, match. */
1964 tree fn = TREE_VALUE (candidates);
1965 *targs_out = copy_node (DECL_TI_ARGS (fn));
1966 /* DECL is a re-declaration or partial instantiation of a template
1968 if (TREE_CODE (fn) == TEMPLATE_DECL)
1970 /* It was a specialization of an ordinary member function in a
1972 return DECL_TI_TEMPLATE (fn);
1975 /* It was a specialization of a template. */
1976 targs = DECL_TI_ARGS (DECL_TEMPLATE_RESULT (TREE_VALUE (templates)));
1977 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (targs))
1979 *targs_out = copy_node (targs);
1980 SET_TMPL_ARGS_LEVEL (*targs_out,
1981 TMPL_ARGS_DEPTH (*targs_out),
1982 TREE_PURPOSE (templates));
1985 *targs_out = TREE_PURPOSE (templates);
1986 return TREE_VALUE (templates);
1989 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
1990 but with the default argument values filled in from those in the
1994 copy_default_args_to_explicit_spec_1 (tree spec_types,
1997 tree new_spec_types;
2002 if (spec_types == void_list_node)
2003 return void_list_node;
2005 /* Substitute into the rest of the list. */
2007 copy_default_args_to_explicit_spec_1 (TREE_CHAIN (spec_types),
2008 TREE_CHAIN (tmpl_types));
2010 /* Add the default argument for this parameter. */
2011 return hash_tree_cons (TREE_PURPOSE (tmpl_types),
2012 TREE_VALUE (spec_types),
2016 /* DECL is an explicit specialization. Replicate default arguments
2017 from the template it specializes. (That way, code like:
2019 template <class T> void f(T = 3);
2020 template <> void f(double);
2023 works, as required.) An alternative approach would be to look up
2024 the correct default arguments at the call-site, but this approach
2025 is consistent with how implicit instantiations are handled. */
2028 copy_default_args_to_explicit_spec (tree decl)
2033 tree new_spec_types;
2037 tree object_type = NULL_TREE;
2038 tree in_charge = NULL_TREE;
2039 tree vtt = NULL_TREE;
2041 /* See if there's anything we need to do. */
2042 tmpl = DECL_TI_TEMPLATE (decl);
2043 tmpl_types = TYPE_ARG_TYPES (TREE_TYPE (DECL_TEMPLATE_RESULT (tmpl)));
2044 for (t = tmpl_types; t; t = TREE_CHAIN (t))
2045 if (TREE_PURPOSE (t))
2050 old_type = TREE_TYPE (decl);
2051 spec_types = TYPE_ARG_TYPES (old_type);
2053 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2055 /* Remove the this pointer, but remember the object's type for
2057 object_type = TREE_TYPE (TREE_VALUE (spec_types));
2058 spec_types = TREE_CHAIN (spec_types);
2059 tmpl_types = TREE_CHAIN (tmpl_types);
2061 if (DECL_HAS_IN_CHARGE_PARM_P (decl))
2063 /* DECL may contain more parameters than TMPL due to the extra
2064 in-charge parameter in constructors and destructors. */
2065 in_charge = spec_types;
2066 spec_types = TREE_CHAIN (spec_types);
2068 if (DECL_HAS_VTT_PARM_P (decl))
2071 spec_types = TREE_CHAIN (spec_types);
2075 /* Compute the merged default arguments. */
2077 copy_default_args_to_explicit_spec_1 (spec_types, tmpl_types);
2079 /* Compute the new FUNCTION_TYPE. */
2083 new_spec_types = hash_tree_cons (TREE_PURPOSE (vtt),
2088 /* Put the in-charge parameter back. */
2089 new_spec_types = hash_tree_cons (TREE_PURPOSE (in_charge),
2090 TREE_VALUE (in_charge),
2093 new_type = build_method_type_directly (object_type,
2094 TREE_TYPE (old_type),
2098 new_type = build_function_type (TREE_TYPE (old_type),
2100 new_type = cp_build_type_attribute_variant (new_type,
2101 TYPE_ATTRIBUTES (old_type));
2102 new_type = build_exception_variant (new_type,
2103 TYPE_RAISES_EXCEPTIONS (old_type));
2104 TREE_TYPE (decl) = new_type;
2107 /* Check to see if the function just declared, as indicated in
2108 DECLARATOR, and in DECL, is a specialization of a function
2109 template. We may also discover that the declaration is an explicit
2110 instantiation at this point.
2112 Returns DECL, or an equivalent declaration that should be used
2113 instead if all goes well. Issues an error message if something is
2114 amiss. Returns error_mark_node if the error is not easily
2117 FLAGS is a bitmask consisting of the following flags:
2119 2: The function has a definition.
2120 4: The function is a friend.
2122 The TEMPLATE_COUNT is the number of references to qualifying
2123 template classes that appeared in the name of the function. For
2126 template <class T> struct S { void f(); };
2129 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2130 classes are not counted in the TEMPLATE_COUNT, so that in
2132 template <class T> struct S {};
2133 template <> struct S<int> { void f(); }
2134 template <> void S<int>::f();
2136 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2137 invalid; there should be no template <>.)
2139 If the function is a specialization, it is marked as such via
2140 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2141 is set up correctly, and it is added to the list of specializations
2142 for that template. */
2145 check_explicit_specialization (tree declarator,
2150 int have_def = flags & 2;
2151 int is_friend = flags & 4;
2152 int specialization = 0;
2153 int explicit_instantiation = 0;
2154 int member_specialization = 0;
2155 tree ctype = DECL_CLASS_CONTEXT (decl);
2156 tree dname = DECL_NAME (decl);
2161 if (!processing_specialization)
2164 tsk = tsk_excessive_parms;
2167 tsk = current_tmpl_spec_kind (template_count);
2172 if (processing_specialization)
2175 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2177 else if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2180 /* This could be something like:
2182 template <class T> void f(T);
2183 class S { friend void f<>(int); } */
2187 /* This case handles bogus declarations like template <>
2188 template <class T> void f<int>(); */
2190 error ("template-id %qD in declaration of primary template",
2197 case tsk_invalid_member_spec:
2198 /* The error has already been reported in
2199 check_specialization_scope. */
2200 return error_mark_node;
2202 case tsk_invalid_expl_inst:
2203 error ("template parameter list used in explicit instantiation");
2209 error ("definition provided for explicit instantiation");
2211 explicit_instantiation = 1;
2214 case tsk_excessive_parms:
2215 case tsk_insufficient_parms:
2216 if (tsk == tsk_excessive_parms)
2217 error ("too many template parameter lists in declaration of %qD",
2219 else if (template_header_count)
2220 error("too few template parameter lists in declaration of %qD", decl);
2222 error("explicit specialization of %qD must be introduced by "
2223 "%<template <>%>", decl);
2227 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2229 member_specialization = 1;
2235 if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2237 /* This case handles bogus declarations like template <>
2238 template <class T> void f<int>(); */
2240 if (uses_template_parms (declarator))
2241 error ("function template partial specialization %qD "
2242 "is not allowed", declarator);
2244 error ("template-id %qD in declaration of primary template",
2249 if (ctype && CLASSTYPE_TEMPLATE_INSTANTIATION (ctype))
2250 /* This is a specialization of a member template, without
2251 specialization the containing class. Something like:
2253 template <class T> struct S {
2254 template <class U> void f (U);
2256 template <> template <class U> void S<int>::f(U) {}
2258 That's a specialization -- but of the entire template. */
2266 if (specialization || member_specialization)
2268 tree t = TYPE_ARG_TYPES (TREE_TYPE (decl));
2269 for (; t; t = TREE_CHAIN (t))
2270 if (TREE_PURPOSE (t))
2272 permerror (input_location,
2273 "default argument specified in explicit specialization");
2278 if (specialization || member_specialization || explicit_instantiation)
2280 tree tmpl = NULL_TREE;
2281 tree targs = NULL_TREE;
2283 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2284 if (TREE_CODE (declarator) != TEMPLATE_ID_EXPR)
2288 gcc_assert (TREE_CODE (declarator) == IDENTIFIER_NODE);
2293 /* If there is no class context, the explicit instantiation
2294 must be at namespace scope. */
2295 gcc_assert (DECL_NAMESPACE_SCOPE_P (decl));
2297 /* Find the namespace binding, using the declaration
2299 fns = lookup_qualified_name (CP_DECL_CONTEXT (decl), dname,
2301 if (fns == error_mark_node || !is_overloaded_fn (fns))
2303 error ("%qD is not a template function", dname);
2304 fns = error_mark_node;
2308 tree fn = OVL_CURRENT (fns);
2309 if (!is_associated_namespace (CP_DECL_CONTEXT (decl),
2310 CP_DECL_CONTEXT (fn)))
2311 error ("%qD is not declared in %qD",
2312 decl, current_namespace);
2316 declarator = lookup_template_function (fns, NULL_TREE);
2319 if (declarator == error_mark_node)
2320 return error_mark_node;
2322 if (ctype != NULL_TREE && TYPE_BEING_DEFINED (ctype))
2324 if (!explicit_instantiation)
2325 /* A specialization in class scope. This is invalid,
2326 but the error will already have been flagged by
2327 check_specialization_scope. */
2328 return error_mark_node;
2331 /* It's not valid to write an explicit instantiation in
2334 class C { template void f(); }
2336 This case is caught by the parser. However, on
2339 template class C { void f(); };
2341 (which is invalid) we can get here. The error will be
2348 else if (ctype != NULL_TREE
2349 && (TREE_CODE (TREE_OPERAND (declarator, 0)) ==
2352 /* Find the list of functions in ctype that have the same
2353 name as the declared function. */
2354 tree name = TREE_OPERAND (declarator, 0);
2355 tree fns = NULL_TREE;
2358 if (constructor_name_p (name, ctype))
2360 int is_constructor = DECL_CONSTRUCTOR_P (decl);
2362 if (is_constructor ? !TYPE_HAS_USER_CONSTRUCTOR (ctype)
2363 : !CLASSTYPE_DESTRUCTORS (ctype))
2365 /* From [temp.expl.spec]:
2367 If such an explicit specialization for the member
2368 of a class template names an implicitly-declared
2369 special member function (clause _special_), the
2370 program is ill-formed.
2372 Similar language is found in [temp.explicit]. */
2373 error ("specialization of implicitly-declared special member function");
2374 return error_mark_node;
2377 name = is_constructor ? ctor_identifier : dtor_identifier;
2380 if (!DECL_CONV_FN_P (decl))
2382 idx = lookup_fnfields_1 (ctype, name);
2384 fns = VEC_index (tree, CLASSTYPE_METHOD_VEC (ctype), idx);
2388 VEC(tree,gc) *methods;
2391 /* For a type-conversion operator, we cannot do a
2392 name-based lookup. We might be looking for `operator
2393 int' which will be a specialization of `operator T'.
2394 So, we find *all* the conversion operators, and then
2395 select from them. */
2398 methods = CLASSTYPE_METHOD_VEC (ctype);
2400 for (idx = CLASSTYPE_FIRST_CONVERSION_SLOT;
2401 VEC_iterate (tree, methods, idx, ovl);
2404 if (!DECL_CONV_FN_P (OVL_CURRENT (ovl)))
2405 /* There are no more conversion functions. */
2408 /* Glue all these conversion functions together
2409 with those we already have. */
2410 for (; ovl; ovl = OVL_NEXT (ovl))
2411 fns = ovl_cons (OVL_CURRENT (ovl), fns);
2415 if (fns == NULL_TREE)
2417 error ("no member function %qD declared in %qT", name, ctype);
2418 return error_mark_node;
2421 TREE_OPERAND (declarator, 0) = fns;
2424 /* Figure out what exactly is being specialized at this point.
2425 Note that for an explicit instantiation, even one for a
2426 member function, we cannot tell apriori whether the
2427 instantiation is for a member template, or just a member
2428 function of a template class. Even if a member template is
2429 being instantiated, the member template arguments may be
2430 elided if they can be deduced from the rest of the
2432 tmpl = determine_specialization (declarator, decl,
2434 member_specialization,
2438 if (!tmpl || tmpl == error_mark_node)
2439 /* We couldn't figure out what this declaration was
2441 return error_mark_node;
2444 tree gen_tmpl = most_general_template (tmpl);
2446 if (explicit_instantiation)
2448 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2449 is done by do_decl_instantiation later. */
2451 int arg_depth = TMPL_ARGS_DEPTH (targs);
2452 int parm_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
2454 if (arg_depth > parm_depth)
2456 /* If TMPL is not the most general template (for
2457 example, if TMPL is a friend template that is
2458 injected into namespace scope), then there will
2459 be too many levels of TARGS. Remove some of them
2464 new_targs = make_tree_vec (parm_depth);
2465 for (i = arg_depth - parm_depth; i < arg_depth; ++i)
2466 TREE_VEC_ELT (new_targs, i - (arg_depth - parm_depth))
2467 = TREE_VEC_ELT (targs, i);
2471 return instantiate_template (tmpl, targs, tf_error);
2474 /* If we thought that the DECL was a member function, but it
2475 turns out to be specializing a static member function,
2476 make DECL a static member function as well. */
2477 if (DECL_STATIC_FUNCTION_P (tmpl)
2478 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2479 revert_static_member_fn (decl);
2481 /* If this is a specialization of a member template of a
2482 template class, we want to return the TEMPLATE_DECL, not
2483 the specialization of it. */
2484 if (tsk == tsk_template)
2486 tree result = DECL_TEMPLATE_RESULT (tmpl);
2487 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
2488 DECL_INITIAL (result) = NULL_TREE;
2492 DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl);
2493 DECL_SOURCE_LOCATION (result)
2494 = DECL_SOURCE_LOCATION (decl);
2495 /* We want to use the argument list specified in the
2496 definition, not in the original declaration. */
2497 DECL_ARGUMENTS (result) = DECL_ARGUMENTS (decl);
2498 for (parm = DECL_ARGUMENTS (result); parm;
2499 parm = TREE_CHAIN (parm))
2500 DECL_CONTEXT (parm) = result;
2502 return register_specialization (tmpl, gen_tmpl, targs,
2506 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2507 DECL_TEMPLATE_INFO (decl) = build_template_info (tmpl, targs);
2509 /* Inherit default function arguments from the template
2510 DECL is specializing. */
2511 copy_default_args_to_explicit_spec (decl);
2513 /* This specialization has the same protection as the
2514 template it specializes. */
2515 TREE_PRIVATE (decl) = TREE_PRIVATE (gen_tmpl);
2516 TREE_PROTECTED (decl) = TREE_PROTECTED (gen_tmpl);
2518 /* 7.1.1-1 [dcl.stc]
2520 A storage-class-specifier shall not be specified in an
2521 explicit specialization...
2523 The parser rejects these, so unless action is taken here,
2524 explicit function specializations will always appear with
2527 The action recommended by the C++ CWG in response to C++
2528 defect report 605 is to make the storage class and linkage
2529 of the explicit specialization match the templated function:
2531 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2533 if (tsk == tsk_expl_spec && DECL_FUNCTION_TEMPLATE_P (gen_tmpl))
2535 tree tmpl_func = DECL_TEMPLATE_RESULT (gen_tmpl);
2536 gcc_assert (TREE_CODE (tmpl_func) == FUNCTION_DECL);
2538 /* This specialization has the same linkage and visibility as
2539 the function template it specializes. */
2540 TREE_PUBLIC (decl) = TREE_PUBLIC (tmpl_func);
2541 if (! TREE_PUBLIC (decl))
2543 DECL_INTERFACE_KNOWN (decl) = 1;
2544 DECL_NOT_REALLY_EXTERN (decl) = 1;
2546 DECL_THIS_STATIC (decl) = DECL_THIS_STATIC (tmpl_func);
2547 if (DECL_VISIBILITY_SPECIFIED (tmpl_func))
2549 DECL_VISIBILITY_SPECIFIED (decl) = 1;
2550 DECL_VISIBILITY (decl) = DECL_VISIBILITY (tmpl_func);
2554 /* If DECL is a friend declaration, declared using an
2555 unqualified name, the namespace associated with DECL may
2556 have been set incorrectly. For example, in:
2558 template <typename T> void f(T);
2560 struct S { friend void f<int>(int); }
2563 we will have set the DECL_CONTEXT for the friend
2564 declaration to N, rather than to the global namespace. */
2565 if (DECL_NAMESPACE_SCOPE_P (decl))
2566 DECL_CONTEXT (decl) = DECL_CONTEXT (tmpl);
2568 if (is_friend && !have_def)
2569 /* This is not really a declaration of a specialization.
2570 It's just the name of an instantiation. But, it's not
2571 a request for an instantiation, either. */
2572 SET_DECL_IMPLICIT_INSTANTIATION (decl);
2573 else if (DECL_CONSTRUCTOR_P (decl) || DECL_DESTRUCTOR_P (decl))
2574 /* This is indeed a specialization. In case of constructors
2575 and destructors, we need in-charge and not-in-charge
2576 versions in V3 ABI. */
2577 clone_function_decl (decl, /*update_method_vec_p=*/0);
2579 /* Register this specialization so that we can find it
2581 decl = register_specialization (decl, gen_tmpl, targs, is_friend, 0);
2588 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2589 parameters. These are represented in the same format used for
2590 DECL_TEMPLATE_PARMS. */
2593 comp_template_parms (const_tree parms1, const_tree parms2)
2598 if (parms1 == parms2)
2601 for (p1 = parms1, p2 = parms2;
2602 p1 != NULL_TREE && p2 != NULL_TREE;
2603 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2))
2605 tree t1 = TREE_VALUE (p1);
2606 tree t2 = TREE_VALUE (p2);
2609 gcc_assert (TREE_CODE (t1) == TREE_VEC);
2610 gcc_assert (TREE_CODE (t2) == TREE_VEC);
2612 if (TREE_VEC_LENGTH (t1) != TREE_VEC_LENGTH (t2))
2615 for (i = 0; i < TREE_VEC_LENGTH (t2); ++i)
2617 tree parm1 = TREE_VALUE (TREE_VEC_ELT (t1, i));
2618 tree parm2 = TREE_VALUE (TREE_VEC_ELT (t2, i));
2620 /* If either of the template parameters are invalid, assume
2621 they match for the sake of error recovery. */
2622 if (parm1 == error_mark_node || parm2 == error_mark_node)
2625 if (TREE_CODE (parm1) != TREE_CODE (parm2))
2628 if (TREE_CODE (parm1) == TEMPLATE_TYPE_PARM
2629 && (TEMPLATE_TYPE_PARAMETER_PACK (parm1)
2630 == TEMPLATE_TYPE_PARAMETER_PACK (parm2)))
2632 else if (!same_type_p (TREE_TYPE (parm1), TREE_TYPE (parm2)))
2637 if ((p1 != NULL_TREE) != (p2 != NULL_TREE))
2638 /* One set of parameters has more parameters lists than the
2645 /* Determine whether PARM is a parameter pack. */
2648 template_parameter_pack_p (const_tree parm)
2650 /* Determine if we have a non-type template parameter pack. */
2651 if (TREE_CODE (parm) == PARM_DECL)
2652 return (DECL_TEMPLATE_PARM_P (parm)
2653 && TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)));
2655 /* If this is a list of template parameters, we could get a
2656 TYPE_DECL or a TEMPLATE_DECL. */
2657 if (TREE_CODE (parm) == TYPE_DECL || TREE_CODE (parm) == TEMPLATE_DECL)
2658 parm = TREE_TYPE (parm);
2660 return ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
2661 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM)
2662 && TEMPLATE_TYPE_PARAMETER_PACK (parm));
2665 /* Determine if T is a function parameter pack. */
2668 function_parameter_pack_p (const_tree t)
2670 if (t && TREE_CODE (t) == PARM_DECL)
2671 return FUNCTION_PARAMETER_PACK_P (t);
2675 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2676 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2679 get_function_template_decl (const_tree primary_func_tmpl_inst)
2681 if (! primary_func_tmpl_inst
2682 || TREE_CODE (primary_func_tmpl_inst) != FUNCTION_DECL
2683 || ! primary_template_instantiation_p (primary_func_tmpl_inst))
2686 return DECL_TEMPLATE_RESULT (DECL_TI_TEMPLATE (primary_func_tmpl_inst));
2689 /* Return true iff the function parameter PARAM_DECL was expanded
2690 from the function parameter pack PACK. */
2693 function_parameter_expanded_from_pack_p (tree param_decl, tree pack)
2695 if (DECL_ARTIFICIAL (param_decl)
2696 || !function_parameter_pack_p (pack))
2699 gcc_assert (DECL_NAME (param_decl) && DECL_NAME (pack));
2701 /* The parameter pack and its pack arguments have the same
2703 return DECL_PARM_INDEX (pack) == DECL_PARM_INDEX (param_decl);
2706 /* Determine whether ARGS describes a variadic template args list,
2707 i.e., one that is terminated by a template argument pack. */
2710 template_args_variadic_p (tree args)
2715 if (args == NULL_TREE)
2718 args = INNERMOST_TEMPLATE_ARGS (args);
2719 nargs = TREE_VEC_LENGTH (args);
2724 last_parm = TREE_VEC_ELT (args, nargs - 1);
2726 return ARGUMENT_PACK_P (last_parm);
2729 /* Generate a new name for the parameter pack name NAME (an
2730 IDENTIFIER_NODE) that incorporates its */
2733 make_ith_pack_parameter_name (tree name, int i)
2735 /* Munge the name to include the parameter index. */
2736 #define NUMBUF_LEN 128
2737 char numbuf[NUMBUF_LEN];
2741 snprintf (numbuf, NUMBUF_LEN, "%i", i);
2742 newname_len = IDENTIFIER_LENGTH (name)
2743 + strlen (numbuf) + 2;
2744 newname = (char*)alloca (newname_len);
2745 snprintf (newname, newname_len,
2746 "%s#%i", IDENTIFIER_POINTER (name), i);
2747 return get_identifier (newname);
2750 /* Return true if T is a primary function
2751 or class template instantiation. */
2754 primary_template_instantiation_p (const_tree t)
2759 if (TREE_CODE (t) == FUNCTION_DECL)
2760 return DECL_LANG_SPECIFIC (t)
2761 && DECL_TEMPLATE_INSTANTIATION (t)
2762 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (t));
2763 else if (CLASS_TYPE_P (t))
2764 return CLASSTYPE_TEMPLATE_INSTANTIATION (t)
2765 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (t));
2769 /* Return true if PARM is a template template parameter. */
2772 template_template_parameter_p (const_tree parm)
2774 return DECL_TEMPLATE_TEMPLATE_PARM_P (parm);
2777 /* Return the template parameters of T if T is a
2778 primary template instantiation, NULL otherwise. */
2781 get_primary_template_innermost_parameters (const_tree t)
2783 tree parms = NULL, template_info = NULL;
2785 if ((template_info = get_template_info (t))
2786 && primary_template_instantiation_p (t))
2787 parms = INNERMOST_TEMPLATE_PARMS
2788 (DECL_TEMPLATE_PARMS (TI_TEMPLATE (template_info)));
2793 /* Returns the template arguments of T if T is a template instantiation,
2797 get_template_innermost_arguments (const_tree t)
2799 tree args = NULL, template_info = NULL;
2801 if ((template_info = get_template_info (t))
2802 && TI_ARGS (template_info))
2803 args = INNERMOST_TEMPLATE_ARGS (TI_ARGS (template_info));
2808 /* Return the argument pack elements of T if T is a template argument pack,
2812 get_template_argument_pack_elems (const_tree t)
2814 if (TREE_CODE (t) != TYPE_ARGUMENT_PACK
2815 && TREE_CODE (t) != NONTYPE_ARGUMENT_PACK)
2818 return ARGUMENT_PACK_ARGS (t);
2821 /* Structure used to track the progress of find_parameter_packs_r. */
2822 struct find_parameter_pack_data
2824 /* TREE_LIST that will contain all of the parameter packs found by
2826 tree* parameter_packs;
2828 /* Set of AST nodes that have been visited by the traversal. */
2829 struct pointer_set_t *visited;
2832 /* Identifies all of the argument packs that occur in a template
2833 argument and appends them to the TREE_LIST inside DATA, which is a
2834 find_parameter_pack_data structure. This is a subroutine of
2835 make_pack_expansion and uses_parameter_packs. */
2837 find_parameter_packs_r (tree *tp, int *walk_subtrees, void* data)
2840 struct find_parameter_pack_data* ppd =
2841 (struct find_parameter_pack_data*)data;
2842 bool parameter_pack_p = false;
2844 /* Identify whether this is a parameter pack or not. */
2845 switch (TREE_CODE (t))
2847 case TEMPLATE_PARM_INDEX:
2848 if (TEMPLATE_PARM_PARAMETER_PACK (t))
2849 parameter_pack_p = true;
2852 case TEMPLATE_TYPE_PARM:
2853 case TEMPLATE_TEMPLATE_PARM:
2854 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
2855 parameter_pack_p = true;
2859 if (FUNCTION_PARAMETER_PACK_P (t))
2861 /* We don't want to walk into the type of a PARM_DECL,
2862 because we don't want to see the type parameter pack. */
2864 parameter_pack_p = true;
2869 /* Not a parameter pack. */
2873 if (parameter_pack_p)
2875 /* Add this parameter pack to the list. */
2876 *ppd->parameter_packs = tree_cons (NULL_TREE, t, *ppd->parameter_packs);
2880 cp_walk_tree (&TYPE_CONTEXT (t),
2881 &find_parameter_packs_r, ppd, ppd->visited);
2883 /* This switch statement will return immediately if we don't find a
2885 switch (TREE_CODE (t))
2887 case TEMPLATE_PARM_INDEX:
2890 case BOUND_TEMPLATE_TEMPLATE_PARM:
2891 /* Check the template itself. */
2892 cp_walk_tree (&TREE_TYPE (TYPE_TI_TEMPLATE (t)),
2893 &find_parameter_packs_r, ppd, ppd->visited);
2894 /* Check the template arguments. */
2895 cp_walk_tree (&TYPE_TI_ARGS (t), &find_parameter_packs_r, ppd,
2900 case TEMPLATE_TYPE_PARM:
2901 case TEMPLATE_TEMPLATE_PARM:
2908 if (TYPE_PTRMEMFUNC_P (t))
2914 if (TYPE_TEMPLATE_INFO (t))
2915 cp_walk_tree (&TI_ARGS (TYPE_TEMPLATE_INFO (t)),
2916 &find_parameter_packs_r, ppd, ppd->visited);
2922 cp_walk_tree (&TREE_TYPE (t),
2923 &find_parameter_packs_r, ppd, ppd->visited);
2927 cp_walk_tree (&TYPENAME_TYPE_FULLNAME (t), &find_parameter_packs_r,
2932 case TYPE_PACK_EXPANSION:
2933 case EXPR_PACK_EXPANSION:
2938 cp_walk_tree (&TYPE_MAX_VALUE (t), &find_parameter_packs_r,
2943 case IDENTIFIER_NODE:
2944 cp_walk_tree (&TREE_TYPE (t), &find_parameter_packs_r, ppd,
2956 /* Determines if the expression or type T uses any parameter packs. */
2958 uses_parameter_packs (tree t)
2960 tree parameter_packs = NULL_TREE;
2961 struct find_parameter_pack_data ppd;
2962 ppd.parameter_packs = ¶meter_packs;
2963 ppd.visited = pointer_set_create ();
2964 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
2965 pointer_set_destroy (ppd.visited);
2966 return parameter_packs != NULL_TREE;
2969 /* Turn ARG, which may be an expression, type, or a TREE_LIST
2970 representation a base-class initializer into a parameter pack
2971 expansion. If all goes well, the resulting node will be an
2972 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
2975 make_pack_expansion (tree arg)
2978 tree parameter_packs = NULL_TREE;
2979 bool for_types = false;
2980 struct find_parameter_pack_data ppd;
2982 if (!arg || arg == error_mark_node)
2985 if (TREE_CODE (arg) == TREE_LIST)
2987 /* The only time we will see a TREE_LIST here is for a base
2988 class initializer. In this case, the TREE_PURPOSE will be a
2989 _TYPE node (representing the base class expansion we're
2990 initializing) and the TREE_VALUE will be a TREE_LIST
2991 containing the initialization arguments.
2993 The resulting expansion looks somewhat different from most
2994 expansions. Rather than returning just one _EXPANSION, we
2995 return a TREE_LIST whose TREE_PURPOSE is a
2996 TYPE_PACK_EXPANSION containing the bases that will be
2997 initialized. The TREE_VALUE will be identical to the
2998 original TREE_VALUE, which is a list of arguments that will
2999 be passed to each base. We do not introduce any new pack
3000 expansion nodes into the TREE_VALUE (although it is possible
3001 that some already exist), because the TREE_PURPOSE and
3002 TREE_VALUE all need to be expanded together with the same
3003 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3004 resulting TREE_PURPOSE will mention the parameter packs in
3005 both the bases and the arguments to the bases. */
3008 tree parameter_packs = NULL_TREE;
3010 /* Determine which parameter packs will be used by the base
3012 ppd.visited = pointer_set_create ();
3013 ppd.parameter_packs = ¶meter_packs;
3014 cp_walk_tree (&TREE_PURPOSE (arg), &find_parameter_packs_r,
3017 if (parameter_packs == NULL_TREE)
3019 error ("base initializer expansion %<%T%> contains no parameter packs", arg);
3020 pointer_set_destroy (ppd.visited);
3021 return error_mark_node;
3024 if (TREE_VALUE (arg) != void_type_node)
3026 /* Collect the sets of parameter packs used in each of the
3027 initialization arguments. */
3028 for (value = TREE_VALUE (arg); value; value = TREE_CHAIN (value))
3030 /* Determine which parameter packs will be expanded in this
3032 cp_walk_tree (&TREE_VALUE (value), &find_parameter_packs_r,
3037 pointer_set_destroy (ppd.visited);
3039 /* Create the pack expansion type for the base type. */
3040 purpose = cxx_make_type (TYPE_PACK_EXPANSION);
3041 SET_PACK_EXPANSION_PATTERN (purpose, TREE_PURPOSE (arg));
3042 PACK_EXPANSION_PARAMETER_PACKS (purpose) = parameter_packs;
3044 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3045 they will rarely be compared to anything. */
3046 SET_TYPE_STRUCTURAL_EQUALITY (purpose);
3048 return tree_cons (purpose, TREE_VALUE (arg), NULL_TREE);
3051 if (TYPE_P (arg) || TREE_CODE (arg) == TEMPLATE_DECL)
3054 /* Build the PACK_EXPANSION_* node. */
3056 ? cxx_make_type (TYPE_PACK_EXPANSION)
3057 : make_node (EXPR_PACK_EXPANSION);
3058 SET_PACK_EXPANSION_PATTERN (result, arg);
3059 if (TREE_CODE (result) == EXPR_PACK_EXPANSION)
3061 /* Propagate type and const-expression information. */
3062 TREE_TYPE (result) = TREE_TYPE (arg);
3063 TREE_CONSTANT (result) = TREE_CONSTANT (arg);
3066 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3067 they will rarely be compared to anything. */
3068 SET_TYPE_STRUCTURAL_EQUALITY (result);
3070 /* Determine which parameter packs will be expanded. */
3071 ppd.parameter_packs = ¶meter_packs;
3072 ppd.visited = pointer_set_create ();
3073 cp_walk_tree (&arg, &find_parameter_packs_r, &ppd, ppd.visited);
3074 pointer_set_destroy (ppd.visited);
3076 /* Make sure we found some parameter packs. */
3077 if (parameter_packs == NULL_TREE)
3080 error ("expansion pattern %<%T%> contains no argument packs", arg);
3082 error ("expansion pattern %<%E%> contains no argument packs", arg);
3083 return error_mark_node;
3085 PACK_EXPANSION_PARAMETER_PACKS (result) = parameter_packs;
3090 /* Checks T for any "bare" parameter packs, which have not yet been
3091 expanded, and issues an error if any are found. This operation can
3092 only be done on full expressions or types (e.g., an expression
3093 statement, "if" condition, etc.), because we could have expressions like:
3095 foo(f(g(h(args)))...)
3097 where "args" is a parameter pack. check_for_bare_parameter_packs
3098 should not be called for the subexpressions args, h(args),
3099 g(h(args)), or f(g(h(args))), because we would produce erroneous
3102 Returns TRUE and emits an error if there were bare parameter packs,
3103 returns FALSE otherwise. */
3105 check_for_bare_parameter_packs (tree t)
3107 tree parameter_packs = NULL_TREE;
3108 struct find_parameter_pack_data ppd;
3110 if (!processing_template_decl || !t || t == error_mark_node)
3113 if (TREE_CODE (t) == TYPE_DECL)
3116 ppd.parameter_packs = ¶meter_packs;
3117 ppd.visited = pointer_set_create ();
3118 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
3119 pointer_set_destroy (ppd.visited);
3121 if (parameter_packs)
3123 error ("parameter packs not expanded with %<...%>:");
3124 while (parameter_packs)
3126 tree pack = TREE_VALUE (parameter_packs);
3127 tree name = NULL_TREE;
3129 if (TREE_CODE (pack) == TEMPLATE_TYPE_PARM
3130 || TREE_CODE (pack) == TEMPLATE_TEMPLATE_PARM)
3131 name = TYPE_NAME (pack);
3132 else if (TREE_CODE (pack) == TEMPLATE_PARM_INDEX)
3133 name = DECL_NAME (TEMPLATE_PARM_DECL (pack));
3135 name = DECL_NAME (pack);
3138 inform (input_location, " %qD", name);
3140 inform (input_location, " <anonymous>");
3142 parameter_packs = TREE_CHAIN (parameter_packs);
3151 /* Expand any parameter packs that occur in the template arguments in
3154 expand_template_argument_pack (tree args)
3156 tree result_args = NULL_TREE;
3157 int in_arg, out_arg = 0, nargs = args ? TREE_VEC_LENGTH (args) : 0;
3158 int num_result_args = -1;
3160 /* First, determine if we need to expand anything, and the number of
3161 slots we'll need. */
3162 for (in_arg = 0; in_arg < nargs; ++in_arg)
3164 tree arg = TREE_VEC_ELT (args, in_arg);
3165 if (arg == NULL_TREE)
3167 if (ARGUMENT_PACK_P (arg))
3169 int num_packed = TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg));
3170 if (num_result_args < 0)
3171 num_result_args = in_arg + num_packed;
3173 num_result_args += num_packed;
3177 if (num_result_args >= 0)
3182 /* If no expansion is necessary, we're done. */
3183 if (num_result_args < 0)
3186 /* Expand arguments. */
3187 result_args = make_tree_vec (num_result_args);
3188 for (in_arg = 0; in_arg < nargs; ++in_arg)
3190 tree arg = TREE_VEC_ELT (args, in_arg);
3191 if (ARGUMENT_PACK_P (arg))
3193 tree packed = ARGUMENT_PACK_ARGS (arg);
3194 int i, num_packed = TREE_VEC_LENGTH (packed);
3195 for (i = 0; i < num_packed; ++i, ++out_arg)
3196 TREE_VEC_ELT (result_args, out_arg) = TREE_VEC_ELT(packed, i);
3200 TREE_VEC_ELT (result_args, out_arg) = arg;
3208 /* Checks if DECL shadows a template parameter.
3210 [temp.local]: A template-parameter shall not be redeclared within its
3211 scope (including nested scopes).
3213 Emits an error and returns TRUE if the DECL shadows a parameter,
3214 returns FALSE otherwise. */
3217 check_template_shadow (tree decl)
3221 /* If we're not in a template, we can't possibly shadow a template
3223 if (!current_template_parms)
3226 /* Figure out what we're shadowing. */
3227 if (TREE_CODE (decl) == OVERLOAD)
3228 decl = OVL_CURRENT (decl);
3229 olddecl = innermost_non_namespace_value (DECL_NAME (decl));
3231 /* If there's no previous binding for this name, we're not shadowing
3232 anything, let alone a template parameter. */
3236 /* If we're not shadowing a template parameter, we're done. Note
3237 that OLDDECL might be an OVERLOAD (or perhaps even an
3238 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3240 if (!DECL_P (olddecl) || !DECL_TEMPLATE_PARM_P (olddecl))
3243 /* We check for decl != olddecl to avoid bogus errors for using a
3244 name inside a class. We check TPFI to avoid duplicate errors for
3245 inline member templates. */
3247 || TEMPLATE_PARMS_FOR_INLINE (current_template_parms))
3250 error ("declaration of %q+#D", decl);
3251 error (" shadows template parm %q+#D", olddecl);
3255 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3256 ORIG_LEVEL, DECL, and TYPE. */
3259 build_template_parm_index (int index,
3265 tree t = make_node (TEMPLATE_PARM_INDEX);
3266 TEMPLATE_PARM_IDX (t) = index;
3267 TEMPLATE_PARM_LEVEL (t) = level;
3268 TEMPLATE_PARM_ORIG_LEVEL (t) = orig_level;
3269 TEMPLATE_PARM_DECL (t) = decl;
3270 TREE_TYPE (t) = type;
3271 TREE_CONSTANT (t) = TREE_CONSTANT (decl);
3272 TREE_READONLY (t) = TREE_READONLY (decl);
3277 /* Find the canonical type parameter for the given template type
3278 parameter. Returns the canonical type parameter, which may be TYPE
3279 if no such parameter existed. */
3281 canonical_type_parameter (tree type)
3284 int idx = TEMPLATE_TYPE_IDX (type);
3285 if (!canonical_template_parms)
3286 canonical_template_parms = VEC_alloc (tree, gc, idx+1);
3288 while (VEC_length (tree, canonical_template_parms) <= (unsigned)idx)
3289 VEC_safe_push (tree, gc, canonical_template_parms, NULL_TREE);
3291 list = VEC_index (tree, canonical_template_parms, idx);
3292 while (list && !comptypes (type, TREE_VALUE (list), COMPARE_STRUCTURAL))
3293 list = TREE_CHAIN (list);
3296 return TREE_VALUE (list);
3299 VEC_replace(tree, canonical_template_parms, idx,
3300 tree_cons (NULL_TREE, type,
3301 VEC_index (tree, canonical_template_parms, idx)));
3306 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3307 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3308 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3309 new one is created. */
3312 reduce_template_parm_level (tree index, tree type, int levels, tree args,
3313 tsubst_flags_t complain)
3315 if (TEMPLATE_PARM_DESCENDANTS (index) == NULL_TREE
3316 || (TEMPLATE_PARM_LEVEL (TEMPLATE_PARM_DESCENDANTS (index))
3317 != TEMPLATE_PARM_LEVEL (index) - levels))
3319 tree orig_decl = TEMPLATE_PARM_DECL (index);
3322 decl = build_decl (DECL_SOURCE_LOCATION (orig_decl),
3323 TREE_CODE (orig_decl), DECL_NAME (orig_decl), type);
3324 TREE_CONSTANT (decl) = TREE_CONSTANT (orig_decl);
3325 TREE_READONLY (decl) = TREE_READONLY (orig_decl);
3326 DECL_ARTIFICIAL (decl) = 1;
3327 SET_DECL_TEMPLATE_PARM_P (decl);
3329 t = build_template_parm_index (TEMPLATE_PARM_IDX (index),
3330 TEMPLATE_PARM_LEVEL (index) - levels,
3331 TEMPLATE_PARM_ORIG_LEVEL (index),
3333 TEMPLATE_PARM_DESCENDANTS (index) = t;
3334 TEMPLATE_PARM_PARAMETER_PACK (t)
3335 = TEMPLATE_PARM_PARAMETER_PACK (index);
3337 /* Template template parameters need this. */
3338 if (TREE_CODE (decl) == TEMPLATE_DECL)
3339 DECL_TEMPLATE_PARMS (decl) = tsubst_template_parms
3340 (DECL_TEMPLATE_PARMS (TEMPLATE_PARM_DECL (index)),
3344 return TEMPLATE_PARM_DESCENDANTS (index);
3347 /* Process information from new template parameter PARM and append it to the
3348 LIST being built. This new parameter is a non-type parameter iff
3349 IS_NON_TYPE is true. This new parameter is a parameter
3350 pack iff IS_PARAMETER_PACK is true. The location of PARM is in
3354 process_template_parm (tree list, location_t parm_loc, tree parm, bool is_non_type,
3355 bool is_parameter_pack)
3362 gcc_assert (TREE_CODE (parm) == TREE_LIST);
3363 defval = TREE_PURPOSE (parm);
3367 tree p = tree_last (list);
3369 if (p && TREE_VALUE (p) != error_mark_node)
3372 if (TREE_CODE (p) == TYPE_DECL || TREE_CODE (p) == TEMPLATE_DECL)
3373 idx = TEMPLATE_TYPE_IDX (TREE_TYPE (p));
3375 idx = TEMPLATE_PARM_IDX (DECL_INITIAL (p));
3385 parm = TREE_VALUE (parm);
3387 SET_DECL_TEMPLATE_PARM_P (parm);
3389 if (TREE_TYPE (parm) == error_mark_node)
3391 err_parm_list = build_tree_list (defval, parm);
3392 TREE_VALUE (err_parm_list) = error_mark_node;
3393 return chainon (list, err_parm_list);
3399 The top-level cv-qualifiers on the template-parameter are
3400 ignored when determining its type. */
3401 TREE_TYPE (parm) = TYPE_MAIN_VARIANT (TREE_TYPE (parm));
3402 if (invalid_nontype_parm_type_p (TREE_TYPE (parm), 1))
3404 err_parm_list = build_tree_list (defval, parm);
3405 TREE_VALUE (err_parm_list) = error_mark_node;
3406 return chainon (list, err_parm_list);
3409 if (uses_parameter_packs (TREE_TYPE (parm)) && !is_parameter_pack)
3411 /* This template parameter is not a parameter pack, but it
3412 should be. Complain about "bare" parameter packs. */
3413 check_for_bare_parameter_packs (TREE_TYPE (parm));
3415 /* Recover by calling this a parameter pack. */
3416 is_parameter_pack = true;
3420 /* A template parameter is not modifiable. */
3421 TREE_CONSTANT (parm) = 1;
3422 TREE_READONLY (parm) = 1;
3423 decl = build_decl (parm_loc,
3424 CONST_DECL, DECL_NAME (parm), TREE_TYPE (parm));
3425 TREE_CONSTANT (decl) = 1;
3426 TREE_READONLY (decl) = 1;
3427 DECL_INITIAL (parm) = DECL_INITIAL (decl)
3428 = build_template_parm_index (idx, processing_template_decl,
3429 processing_template_decl,
3430 decl, TREE_TYPE (parm));
3432 TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))
3433 = is_parameter_pack;
3438 parm = TREE_VALUE (TREE_VALUE (parm));
3440 if (parm && TREE_CODE (parm) == TEMPLATE_DECL)
3442 t = cxx_make_type (TEMPLATE_TEMPLATE_PARM);
3443 /* This is for distinguishing between real templates and template
3444 template parameters */
3445 TREE_TYPE (parm) = t;
3446 TREE_TYPE (DECL_TEMPLATE_RESULT (parm)) = t;
3451 t = cxx_make_type (TEMPLATE_TYPE_PARM);
3452 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3453 decl = build_decl (parm_loc,
3454 TYPE_DECL, parm, t);
3457 TYPE_NAME (t) = decl;
3458 TYPE_STUB_DECL (t) = decl;
3460 TEMPLATE_TYPE_PARM_INDEX (t)
3461 = build_template_parm_index (idx, processing_template_decl,
3462 processing_template_decl,
3463 decl, TREE_TYPE (parm));
3464 TEMPLATE_TYPE_PARAMETER_PACK (t) = is_parameter_pack;
3465 TYPE_CANONICAL (t) = canonical_type_parameter (t);
3467 DECL_ARTIFICIAL (decl) = 1;
3468 SET_DECL_TEMPLATE_PARM_P (decl);
3470 parm = build_tree_list (defval, parm);
3471 return chainon (list, parm);
3474 /* The end of a template parameter list has been reached. Process the
3475 tree list into a parameter vector, converting each parameter into a more
3476 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3480 end_template_parm_list (tree parms)
3484 tree saved_parmlist = make_tree_vec (list_length (parms));
3486 current_template_parms
3487 = tree_cons (size_int (processing_template_decl),
3488 saved_parmlist, current_template_parms);
3490 for (parm = parms, nparms = 0; parm; parm = next, nparms++)
3492 next = TREE_CHAIN (parm);
3493 TREE_VEC_ELT (saved_parmlist, nparms) = parm;
3494 TREE_CHAIN (parm) = NULL_TREE;
3497 --processing_template_parmlist;
3499 return saved_parmlist;
3502 /* end_template_decl is called after a template declaration is seen. */
3505 end_template_decl (void)
3507 reset_specialization ();
3509 if (! processing_template_decl)
3512 /* This matches the pushlevel in begin_template_parm_list. */
3515 --processing_template_decl;
3516 current_template_parms = TREE_CHAIN (current_template_parms);
3519 /* Within the declaration of a template, return all levels of template
3520 parameters that apply. The template parameters are represented as
3521 a TREE_VEC, in the form documented in cp-tree.h for template
3525 current_template_args (void)
3528 tree args = NULL_TREE;
3529 int length = TMPL_PARMS_DEPTH (current_template_parms);
3532 /* If there is only one level of template parameters, we do not
3533 create a TREE_VEC of TREE_VECs. Instead, we return a single
3534 TREE_VEC containing the arguments. */
3536 args = make_tree_vec (length);
3538 for (header = current_template_parms; header; header = TREE_CHAIN (header))
3540 tree a = copy_node (TREE_VALUE (header));
3543 TREE_TYPE (a) = NULL_TREE;
3544 for (i = TREE_VEC_LENGTH (a) - 1; i >= 0; --i)
3546 tree t = TREE_VEC_ELT (a, i);
3548 /* T will be a list if we are called from within a
3549 begin/end_template_parm_list pair, but a vector directly
3550 if within a begin/end_member_template_processing pair. */
3551 if (TREE_CODE (t) == TREE_LIST)
3555 if (!error_operand_p (t))
3557 if (TREE_CODE (t) == TYPE_DECL
3558 || TREE_CODE (t) == TEMPLATE_DECL)
3562 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
3564 /* Turn this argument into a TYPE_ARGUMENT_PACK
3565 with a single element, which expands T. */
3566 tree vec = make_tree_vec (1);
3567 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
3569 t = cxx_make_type (TYPE_ARGUMENT_PACK);
3570 SET_ARGUMENT_PACK_ARGS (t, vec);
3575 t = DECL_INITIAL (t);
3577 if (TEMPLATE_PARM_PARAMETER_PACK (t))
3579 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3580 with a single element, which expands T. */
3581 tree vec = make_tree_vec (1);
3582 tree type = TREE_TYPE (TEMPLATE_PARM_DECL (t));
3583 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
3585 t = make_node (NONTYPE_ARGUMENT_PACK);
3586 SET_ARGUMENT_PACK_ARGS (t, vec);
3587 TREE_TYPE (t) = type;
3590 TREE_VEC_ELT (a, i) = t;
3596 TREE_VEC_ELT (args, --l) = a;
3604 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
3605 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
3606 a member template. Used by push_template_decl below. */
3609 build_template_decl (tree decl, tree parms, bool member_template_p)
3611 tree tmpl = build_lang_decl (TEMPLATE_DECL, DECL_NAME (decl), NULL_TREE);
3612 DECL_TEMPLATE_PARMS (tmpl) = parms;
3613 DECL_CONTEXT (tmpl) = DECL_CONTEXT (decl);
3614 DECL_MEMBER_TEMPLATE_P (tmpl) = member_template_p;
3619 struct template_parm_data
3621 /* The level of the template parameters we are currently
3625 /* The index of the specialization argument we are currently
3629 /* An array whose size is the number of template parameters. The
3630 elements are nonzero if the parameter has been used in any one
3631 of the arguments processed so far. */
3634 /* An array whose size is the number of template arguments. The
3635 elements are nonzero if the argument makes use of template
3636 parameters of this level. */
3637 int* arg_uses_template_parms;
3640 /* Subroutine of push_template_decl used to see if each template
3641 parameter in a partial specialization is used in the explicit
3642 argument list. If T is of the LEVEL given in DATA (which is
3643 treated as a template_parm_data*), then DATA->PARMS is marked
3647 mark_template_parm (tree t, void* data)
3651 struct template_parm_data* tpd = (struct template_parm_data*) data;
3653 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
3655 level = TEMPLATE_PARM_LEVEL (t);
3656 idx = TEMPLATE_PARM_IDX (t);
3660 level = TEMPLATE_TYPE_LEVEL (t);
3661 idx = TEMPLATE_TYPE_IDX (t);
3664 if (level == tpd->level)
3666 tpd->parms[idx] = 1;
3667 tpd->arg_uses_template_parms[tpd->current_arg] = 1;
3670 /* Return zero so that for_each_template_parm will continue the
3671 traversal of the tree; we want to mark *every* template parm. */
3675 /* Process the partial specialization DECL. */
3678 process_partial_specialization (tree decl)
3680 tree type = TREE_TYPE (decl);
3681 tree maintmpl = CLASSTYPE_TI_TEMPLATE (type);
3682 tree specargs = CLASSTYPE_TI_ARGS (type);
3683 tree inner_args = INNERMOST_TEMPLATE_ARGS (specargs);
3684 tree main_inner_parms = DECL_INNERMOST_TEMPLATE_PARMS (maintmpl);
3686 int nargs = TREE_VEC_LENGTH (inner_args);
3689 int did_error_intro = 0;
3690 struct template_parm_data tpd;
3691 struct template_parm_data tpd2;
3693 gcc_assert (current_template_parms);
3695 inner_parms = INNERMOST_TEMPLATE_PARMS (current_template_parms);
3696 ntparms = TREE_VEC_LENGTH (inner_parms);
3698 /* We check that each of the template parameters given in the
3699 partial specialization is used in the argument list to the
3700 specialization. For example:
3702 template <class T> struct S;
3703 template <class T> struct S<T*>;
3705 The second declaration is OK because `T*' uses the template
3706 parameter T, whereas
3708 template <class T> struct S<int>;
3710 is no good. Even trickier is:
3721 The S2<T> declaration is actually invalid; it is a
3722 full-specialization. Of course,
3725 struct S2<T (*)(U)>;
3727 or some such would have been OK. */
3728 tpd.level = TMPL_PARMS_DEPTH (current_template_parms);
3729 tpd.parms = (int *) alloca (sizeof (int) * ntparms);
3730 memset (tpd.parms, 0, sizeof (int) * ntparms);
3732 tpd.arg_uses_template_parms = (int *) alloca (sizeof (int) * nargs);
3733 memset (tpd.arg_uses_template_parms, 0, sizeof (int) * nargs);
3734 for (i = 0; i < nargs; ++i)
3736 tpd.current_arg = i;
3737 for_each_template_parm (TREE_VEC_ELT (inner_args, i),
3738 &mark_template_parm,
3741 /*include_nondeduced_p=*/false);
3743 for (i = 0; i < ntparms; ++i)
3744 if (tpd.parms[i] == 0)
3746 /* One of the template parms was not used in the
3748 if (!did_error_intro)
3750 error ("template parameters not used in partial specialization:");
3751 did_error_intro = 1;
3754 error (" %qD", TREE_VALUE (TREE_VEC_ELT (inner_parms, i)));
3757 /* [temp.class.spec]
3759 The argument list of the specialization shall not be identical to
3760 the implicit argument list of the primary template. */
3761 if (comp_template_args
3763 INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE
3765 error ("partial specialization %qT does not specialize any template arguments", type);
3767 /* [temp.class.spec]
3769 A partially specialized non-type argument expression shall not
3770 involve template parameters of the partial specialization except
3771 when the argument expression is a simple identifier.
3773 The type of a template parameter corresponding to a specialized
3774 non-type argument shall not be dependent on a parameter of the
3777 Also, we verify that pack expansions only occur at the
3778 end of the argument list. */
3779 gcc_assert (nargs == DECL_NTPARMS (maintmpl));
3781 for (i = 0; i < nargs; ++i)
3783 tree parm = TREE_VALUE (TREE_VEC_ELT (main_inner_parms, i));
3784 tree arg = TREE_VEC_ELT (inner_args, i);
3785 tree packed_args = NULL_TREE;
3788 if (ARGUMENT_PACK_P (arg))
3790 /* Extract the arguments from the argument pack. We'll be
3791 iterating over these in the following loop. */
3792 packed_args = ARGUMENT_PACK_ARGS (arg);
3793 len = TREE_VEC_LENGTH (packed_args);
3796 for (j = 0; j < len; j++)
3799 /* Get the Jth argument in the parameter pack. */
3800 arg = TREE_VEC_ELT (packed_args, j);
3802 if (PACK_EXPANSION_P (arg))
3804 /* Pack expansions must come at the end of the
3806 if ((packed_args && j < len - 1)
3807 || (!packed_args && i < nargs - 1))
3809 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
3810 error ("parameter pack argument %qE must be at the "
3811 "end of the template argument list", arg);
3813 error ("parameter pack argument %qT must be at the "
3814 "end of the template argument list", arg);
3818 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
3819 /* We only care about the pattern. */
3820 arg = PACK_EXPANSION_PATTERN (arg);
3822 if (/* These first two lines are the `non-type' bit. */
3824 && TREE_CODE (arg) != TEMPLATE_DECL
3825 /* This next line is the `argument expression is not just a
3826 simple identifier' condition and also the `specialized
3827 non-type argument' bit. */
3828 && TREE_CODE (arg) != TEMPLATE_PARM_INDEX)
3830 if ((!packed_args && tpd.arg_uses_template_parms[i])
3831 || (packed_args && uses_template_parms (arg)))
3832 error ("template argument %qE involves template parameter(s)",
3836 /* Look at the corresponding template parameter,
3837 marking which template parameters its type depends
3839 tree type = TREE_TYPE (parm);
3843 /* We haven't yet initialized TPD2. Do so now. */
3844 tpd2.arg_uses_template_parms
3845 = (int *) alloca (sizeof (int) * nargs);
3846 /* The number of parameters here is the number in the
3847 main template, which, as checked in the assertion
3849 tpd2.parms = (int *) alloca (sizeof (int) * nargs);
3851 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (maintmpl));
3854 /* Mark the template parameters. But this time, we're
3855 looking for the template parameters of the main
3856 template, not in the specialization. */
3857 tpd2.current_arg = i;
3858 tpd2.arg_uses_template_parms[i] = 0;
3859 memset (tpd2.parms, 0, sizeof (int) * nargs);
3860 for_each_template_parm (type,
3861 &mark_template_parm,
3864 /*include_nondeduced_p=*/false);
3866 if (tpd2.arg_uses_template_parms [i])
3868 /* The type depended on some template parameters.
3869 If they are fully specialized in the
3870 specialization, that's OK. */
3872 for (j = 0; j < nargs; ++j)
3873 if (tpd2.parms[j] != 0
3874 && tpd.arg_uses_template_parms [j])
3876 error ("type %qT of template argument %qE depends "
3877 "on template parameter(s)",
3888 /* We should only get here once. */
3889 gcc_assert (!COMPLETE_TYPE_P (type));
3891 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)
3892 = tree_cons (specargs, inner_parms,
3893 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl));
3894 TREE_TYPE (DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)) = type;
3898 /* Check that a template declaration's use of default arguments and
3899 parameter packs is not invalid. Here, PARMS are the template
3900 parameters. IS_PRIMARY is nonzero if DECL is the thing declared by
3901 a primary template. IS_PARTIAL is nonzero if DECL is a partial
3905 IS_FRIEND_DECL is nonzero if DECL is a friend function template
3906 declaration (but not a definition); 1 indicates a declaration, 2
3907 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
3908 emitted for extraneous default arguments.
3910 Returns TRUE if there were no errors found, FALSE otherwise. */
3913 check_default_tmpl_args (tree decl, tree parms, int is_primary,
3914 int is_partial, int is_friend_decl)
3917 int last_level_to_check;
3919 bool no_errors = true;
3923 A default template-argument shall not be specified in a
3924 function template declaration or a function template definition, nor
3925 in the template-parameter-list of the definition of a member of a
3928 if (TREE_CODE (CP_DECL_CONTEXT (decl)) == FUNCTION_DECL)
3929 /* You can't have a function template declaration in a local
3930 scope, nor you can you define a member of a class template in a
3934 if (current_class_type
3935 && !TYPE_BEING_DEFINED (current_class_type)
3936 && DECL_LANG_SPECIFIC (decl)
3937 && DECL_DECLARES_FUNCTION_P (decl)
3938 /* If this is either a friend defined in the scope of the class
3939 or a member function. */
3940 && (DECL_FUNCTION_MEMBER_P (decl)
3941 ? same_type_p (DECL_CONTEXT (decl), current_class_type)
3942 : DECL_FRIEND_CONTEXT (decl)
3943 ? same_type_p (DECL_FRIEND_CONTEXT (decl), current_class_type)
3945 /* And, if it was a member function, it really was defined in
3946 the scope of the class. */
3947 && (!DECL_FUNCTION_MEMBER_P (decl)
3948 || DECL_INITIALIZED_IN_CLASS_P (decl)))
3949 /* We already checked these parameters when the template was
3950 declared, so there's no need to do it again now. This function
3951 was defined in class scope, but we're processing it's body now
3952 that the class is complete. */
3955 /* Core issue 226 (C++0x only): the following only applies to class
3957 if ((cxx_dialect == cxx98) || TREE_CODE (decl) != FUNCTION_DECL)
3961 If a template-parameter has a default template-argument, all
3962 subsequent template-parameters shall have a default
3963 template-argument supplied. */
3964 for (parm_level = parms; parm_level; parm_level = TREE_CHAIN (parm_level))
3966 tree inner_parms = TREE_VALUE (parm_level);
3967 int ntparms = TREE_VEC_LENGTH (inner_parms);
3968 int seen_def_arg_p = 0;
3971 for (i = 0; i < ntparms; ++i)
3973 tree parm = TREE_VEC_ELT (inner_parms, i);
3975 if (parm == error_mark_node)
3978 if (TREE_PURPOSE (parm))
3980 else if (seen_def_arg_p
3981 && !template_parameter_pack_p (TREE_VALUE (parm)))
3983 error ("no default argument for %qD", TREE_VALUE (parm));
3984 /* For better subsequent error-recovery, we indicate that
3985 there should have been a default argument. */
3986 TREE_PURPOSE (parm) = error_mark_node;
3992 /* Don't complain about an enclosing partial
3994 && parm_level == parms
3995 && TREE_CODE (decl) == TYPE_DECL
3997 && template_parameter_pack_p (TREE_VALUE (parm)))
3999 /* A primary class template can only have one
4000 parameter pack, at the end of the template
4003 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL)
4004 error ("parameter pack %qE must be at the end of the"
4005 " template parameter list", TREE_VALUE (parm));
4007 error ("parameter pack %qT must be at the end of the"
4008 " template parameter list",
4009 TREE_TYPE (TREE_VALUE (parm)));
4011 TREE_VALUE (TREE_VEC_ELT (inner_parms, i))
4019 if (((cxx_dialect == cxx98) && TREE_CODE (decl) != TYPE_DECL)
4023 /* For an ordinary class template, default template arguments are
4024 allowed at the innermost level, e.g.:
4025 template <class T = int>
4027 but, in a partial specialization, they're not allowed even
4028 there, as we have in [temp.class.spec]:
4030 The template parameter list of a specialization shall not
4031 contain default template argument values.
4033 So, for a partial specialization, or for a function template
4034 (in C++98/C++03), we look at all of them. */
4037 /* But, for a primary class template that is not a partial
4038 specialization we look at all template parameters except the
4040 parms = TREE_CHAIN (parms);
4042 /* Figure out what error message to issue. */
4043 if (is_friend_decl == 2)
4044 msg = "default template arguments may not be used in function template friend re-declaration";
4045 else if (is_friend_decl)
4046 msg = "default template arguments may not be used in function template friend declarations";
4047 else if (TREE_CODE (decl) == FUNCTION_DECL && (cxx_dialect == cxx98))
4048 msg = ("default template arguments may not be used in function templates "
4049 "without -std=c++0x or -std=gnu++0x");
4050 else if (is_partial)
4051 msg = "default template arguments may not be used in partial specializations";
4053 msg = "default argument for template parameter for class enclosing %qD";
4055 if (current_class_type && TYPE_BEING_DEFINED (current_class_type))
4056 /* If we're inside a class definition, there's no need to
4057 examine the parameters to the class itself. On the one
4058 hand, they will be checked when the class is defined, and,
4059 on the other, default arguments are valid in things like:
4060 template <class T = double>
4061 struct S { template <class U> void f(U); };
4062 Here the default argument for `S' has no bearing on the
4063 declaration of `f'. */
4064 last_level_to_check = template_class_depth (current_class_type) + 1;
4066 /* Check everything. */
4067 last_level_to_check = 0;
4069 for (parm_level = parms;
4070 parm_level && TMPL_PARMS_DEPTH (parm_level) >= last_level_to_check;
4071 parm_level = TREE_CHAIN (parm_level))
4073 tree inner_parms = TREE_VALUE (parm_level);
4077 ntparms = TREE_VEC_LENGTH (inner_parms);
4078 for (i = 0; i < ntparms; ++i)
4080 if (TREE_VEC_ELT (inner_parms, i) == error_mark_node)
4083 if (TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)))
4088 if (is_friend_decl == 2)
4095 /* Clear out the default argument so that we are not
4097 TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)) = NULL_TREE;
4101 /* At this point, if we're still interested in issuing messages,
4102 they must apply to classes surrounding the object declared. */
4104 msg = "default argument for template parameter for class enclosing %qD";
4110 /* Worker for push_template_decl_real, called via
4111 for_each_template_parm. DATA is really an int, indicating the
4112 level of the parameters we are interested in. If T is a template
4113 parameter of that level, return nonzero. */
4116 template_parm_this_level_p (tree t, void* data)
4118 int this_level = *(int *)data;
4121 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
4122 level = TEMPLATE_PARM_LEVEL (t);
4124 level = TEMPLATE_TYPE_LEVEL (t);
4125 return level == this_level;
4128 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4129 parameters given by current_template_args, or reuses a
4130 previously existing one, if appropriate. Returns the DECL, or an
4131 equivalent one, if it is replaced via a call to duplicate_decls.
4133 If IS_FRIEND is true, DECL is a friend declaration. */
4136 push_template_decl_real (tree decl, bool is_friend)
4144 int new_template_p = 0;
4145 /* True if the template is a member template, in the sense of
4147 bool member_template_p = false;
4149 if (decl == error_mark_node || !current_template_parms)
4150 return error_mark_node;
4152 /* See if this is a partial specialization. */
4153 is_partial = (DECL_IMPLICIT_TYPEDEF_P (decl)
4154 && TREE_CODE (TREE_TYPE (decl)) != ENUMERAL_TYPE
4155 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)));
4157 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_FRIEND_P (decl))
4161 /* For a friend, we want the context of the friend function, not
4162 the type of which it is a friend. */
4163 ctx = DECL_CONTEXT (decl);
4164 else if (CP_DECL_CONTEXT (decl)
4165 && TREE_CODE (CP_DECL_CONTEXT (decl)) != NAMESPACE_DECL)
4166 /* In the case of a virtual function, we want the class in which
4168 ctx = CP_DECL_CONTEXT (decl);
4170 /* Otherwise, if we're currently defining some class, the DECL
4171 is assumed to be a member of the class. */
4172 ctx = current_scope ();
4174 if (ctx && TREE_CODE (ctx) == NAMESPACE_DECL)
4177 if (!DECL_CONTEXT (decl))
4178 DECL_CONTEXT (decl) = FROB_CONTEXT (current_namespace);
4180 /* See if this is a primary template. */
4181 if (is_friend && ctx)
4182 /* A friend template that specifies a class context, i.e.
4183 template <typename T> friend void A<T>::f();
4187 primary = template_parm_scope_p ();
4191 if (DECL_CLASS_SCOPE_P (decl))
4192 member_template_p = true;
4193 if (TREE_CODE (decl) == TYPE_DECL
4194 && ANON_AGGRNAME_P (DECL_NAME (decl)))
4196 error ("template class without a name");
4197 return error_mark_node;
4199 else if (TREE_CODE (decl) == FUNCTION_DECL)
4201 if (DECL_DESTRUCTOR_P (decl))
4205 A destructor shall not be a member template. */
4206 error ("destructor %qD declared as member template", decl);
4207 return error_mark_node;
4209 if (NEW_DELETE_OPNAME_P (DECL_NAME (decl))
4210 && (!TYPE_ARG_TYPES (TREE_TYPE (decl))
4211 || TYPE_ARG_TYPES (TREE_TYPE (decl)) == void_list_node
4212 || !TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (decl)))
4213 || (TREE_CHAIN (TYPE_ARG_TYPES ((TREE_TYPE (decl))))
4214 == void_list_node)))
4216 /* [basic.stc.dynamic.allocation]
4218 An allocation function can be a function
4219 template. ... Template allocation functions shall
4220 have two or more parameters. */
4221 error ("invalid template declaration of %qD", decl);
4222 return error_mark_node;
4225 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4226 && CLASS_TYPE_P (TREE_TYPE (decl)))
4230 error ("template declaration of %q#D", decl);
4231 return error_mark_node;
4235 /* Check to see that the rules regarding the use of default
4236 arguments are not being violated. */
4237 check_default_tmpl_args (decl, current_template_parms,
4238 primary, is_partial, /*is_friend_decl=*/0);
4240 /* Ensure that there are no parameter packs in the type of this
4241 declaration that have not been expanded. */
4242 if (TREE_CODE (decl) == FUNCTION_DECL)
4244 /* Check each of the arguments individually to see if there are
4245 any bare parameter packs. */
4246 tree type = TREE_TYPE (decl);
4247 tree arg = DECL_ARGUMENTS (decl);
4248 tree argtype = TYPE_ARG_TYPES (type);
4250 while (arg && argtype)
4252 if (!FUNCTION_PARAMETER_PACK_P (arg)
4253 && check_for_bare_parameter_packs (TREE_TYPE (arg)))
4255 /* This is a PARM_DECL that contains unexpanded parameter
4256 packs. We have already complained about this in the
4257 check_for_bare_parameter_packs call, so just replace
4258 these types with ERROR_MARK_NODE. */
4259 TREE_TYPE (arg) = error_mark_node;
4260 TREE_VALUE (argtype) = error_mark_node;
4263 arg = TREE_CHAIN (arg);
4264 argtype = TREE_CHAIN (argtype);
4267 /* Check for bare parameter packs in the return type and the
4268 exception specifiers. */
4269 if (check_for_bare_parameter_packs (TREE_TYPE (type)))
4270 /* Errors were already issued, set return type to int
4271 as the frontend doesn't expect error_mark_node as
4273 TREE_TYPE (type) = integer_type_node;
4274 if (check_for_bare_parameter_packs (TYPE_RAISES_EXCEPTIONS (type)))
4275 TYPE_RAISES_EXCEPTIONS (type) = NULL_TREE;
4277 else if (check_for_bare_parameter_packs (TREE_TYPE (decl)))
4279 TREE_TYPE (decl) = error_mark_node;
4280 return error_mark_node;
4284 return process_partial_specialization (decl);
4286 args = current_template_args ();
4289 || TREE_CODE (ctx) == FUNCTION_DECL
4290 || (CLASS_TYPE_P (ctx) && TYPE_BEING_DEFINED (ctx))
4291 || (is_friend && !DECL_TEMPLATE_INFO (decl)))
4293 if (DECL_LANG_SPECIFIC (decl)
4294 && DECL_TEMPLATE_INFO (decl)
4295 && DECL_TI_TEMPLATE (decl))
4296 tmpl = DECL_TI_TEMPLATE (decl);
4297 /* If DECL is a TYPE_DECL for a class-template, then there won't
4298 be DECL_LANG_SPECIFIC. The information equivalent to
4299 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4300 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4301 && TYPE_TEMPLATE_INFO (TREE_TYPE (decl))
4302 && TYPE_TI_TEMPLATE (TREE_TYPE (decl)))
4304 /* Since a template declaration already existed for this
4305 class-type, we must be redeclaring it here. Make sure
4306 that the redeclaration is valid. */
4307 redeclare_class_template (TREE_TYPE (decl),
4308 current_template_parms);
4309 /* We don't need to create a new TEMPLATE_DECL; just use the
4310 one we already had. */
4311 tmpl = TYPE_TI_TEMPLATE (TREE_TYPE (decl));
4315 tmpl = build_template_decl (decl, current_template_parms,
4319 if (DECL_LANG_SPECIFIC (decl)
4320 && DECL_TEMPLATE_SPECIALIZATION (decl))
4322 /* A specialization of a member template of a template
4324 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
4325 DECL_TEMPLATE_INFO (tmpl) = DECL_TEMPLATE_INFO (decl);
4326 DECL_TEMPLATE_INFO (decl) = NULL_TREE;
4332 tree a, t, current, parms;
4334 tree tinfo = get_template_info (decl);
4338 error ("template definition of non-template %q#D", decl);
4339 return error_mark_node;
4342 tmpl = TI_TEMPLATE (tinfo);
4344 if (DECL_FUNCTION_TEMPLATE_P (tmpl)
4345 && DECL_TEMPLATE_INFO (decl) && DECL_TI_ARGS (decl)
4346 && DECL_TEMPLATE_SPECIALIZATION (decl)
4347 && DECL_MEMBER_TEMPLATE_P (tmpl))
4351 /* The declaration is a specialization of a member
4352 template, declared outside the class. Therefore, the
4353 innermost template arguments will be NULL, so we
4354 replace them with the arguments determined by the
4355 earlier call to check_explicit_specialization. */
4356 args = DECL_TI_ARGS (decl);
4359 = build_template_decl (decl, current_template_parms,
4361 DECL_TEMPLATE_RESULT (new_tmpl) = decl;
4362 TREE_TYPE (new_tmpl) = TREE_TYPE (decl);
4363 DECL_TI_TEMPLATE (decl) = new_tmpl;
4364 SET_DECL_TEMPLATE_SPECIALIZATION (new_tmpl);
4365 DECL_TEMPLATE_INFO (new_tmpl)
4366 = build_template_info (tmpl, args);
4368 register_specialization (new_tmpl,
4369 most_general_template (tmpl),
4375 /* Make sure the template headers we got make sense. */
4377 parms = DECL_TEMPLATE_PARMS (tmpl);
4378 i = TMPL_PARMS_DEPTH (parms);
4379 if (TMPL_ARGS_DEPTH (args) != i)
4381 error ("expected %d levels of template parms for %q#D, got %d",
4382 i, decl, TMPL_ARGS_DEPTH (args));
4385 for (current = decl; i > 0; --i, parms = TREE_CHAIN (parms))
4387 a = TMPL_ARGS_LEVEL (args, i);
4388 t = INNERMOST_TEMPLATE_PARMS (parms);
4390 if (TREE_VEC_LENGTH (t) != TREE_VEC_LENGTH (a))
4392 if (current == decl)
4393 error ("got %d template parameters for %q#D",
4394 TREE_VEC_LENGTH (a), decl);
4396 error ("got %d template parameters for %q#T",
4397 TREE_VEC_LENGTH (a), current);
4398 error (" but %d required", TREE_VEC_LENGTH (t));
4399 return error_mark_node;
4402 if (current == decl)
4405 current = (TYPE_P (current)
4406 ? TYPE_CONTEXT (current)
4407 : DECL_CONTEXT (current));
4410 /* Check that the parms are used in the appropriate qualifying scopes
4411 in the declarator. */
4412 if (!comp_template_args
4414 TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (tmpl)))))
4417 template arguments to %qD do not match original template %qD",
4418 decl, DECL_TEMPLATE_RESULT (tmpl));
4419 if (!uses_template_parms (TI_ARGS (tinfo)))
4420 inform (input_location, "use template<> for an explicit specialization");
4421 /* Avoid crash in import_export_decl. */
4422 DECL_INTERFACE_KNOWN (decl) = 1;
4423 return error_mark_node;
4427 DECL_TEMPLATE_RESULT (tmpl) = decl;
4428 TREE_TYPE (tmpl) = TREE_TYPE (decl);
4430 /* Push template declarations for global functions and types. Note
4431 that we do not try to push a global template friend declared in a
4432 template class; such a thing may well depend on the template
4433 parameters of the class. */
4434 if (new_template_p && !ctx
4435 && !(is_friend && template_class_depth (current_class_type) > 0))
4437 tmpl = pushdecl_namespace_level (tmpl, is_friend);
4438 if (tmpl == error_mark_node)
4439 return error_mark_node;
4441 /* Hide template friend classes that haven't been declared yet. */
4442 if (is_friend && TREE_CODE (decl) == TYPE_DECL)
4444 DECL_ANTICIPATED (tmpl) = 1;
4445 DECL_FRIEND_P (tmpl) = 1;
4451 tree parms = DECL_TEMPLATE_PARMS (tmpl);
4454 DECL_PRIMARY_TEMPLATE (tmpl) = tmpl;
4455 if (DECL_CONV_FN_P (tmpl))
4457 int depth = TMPL_PARMS_DEPTH (parms);
4459 /* It is a conversion operator. See if the type converted to
4460 depends on innermost template operands. */
4462 if (uses_template_parms_level (TREE_TYPE (TREE_TYPE (tmpl)),
4464 DECL_TEMPLATE_CONV_FN_P (tmpl) = 1;
4467 /* Give template template parms a DECL_CONTEXT of the template
4468 for which they are a parameter. */
4469 parms = INNERMOST_TEMPLATE_PARMS (parms);
4470 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
4472 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
4473 if (TREE_CODE (parm) == TEMPLATE_DECL)
4474 DECL_CONTEXT (parm) = tmpl;
4478 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
4479 back to its most general template. If TMPL is a specialization,
4480 ARGS may only have the innermost set of arguments. Add the missing
4481 argument levels if necessary. */
4482 if (DECL_TEMPLATE_INFO (tmpl))
4483 args = add_outermost_template_args (DECL_TI_ARGS (tmpl), args);
4485 info = build_template_info (tmpl, args);
4487 if (DECL_IMPLICIT_TYPEDEF_P (decl))
4488 SET_TYPE_TEMPLATE_INFO (TREE_TYPE (tmpl), info);
4489 else if (DECL_LANG_SPECIFIC (decl))
4490 DECL_TEMPLATE_INFO (decl) = info;
4492 return DECL_TEMPLATE_RESULT (tmpl);
4496 push_template_decl (tree decl)
4498 return push_template_decl_real (decl, false);
4501 /* Called when a class template TYPE is redeclared with the indicated
4502 template PARMS, e.g.:
4504 template <class T> struct S;
4505 template <class T> struct S {}; */
4508 redeclare_class_template (tree type, tree parms)
4514 if (!TYPE_TEMPLATE_INFO (type))
4516 error ("%qT is not a template type", type);
4520 tmpl = TYPE_TI_TEMPLATE (type);
4521 if (!PRIMARY_TEMPLATE_P (tmpl))
4522 /* The type is nested in some template class. Nothing to worry
4523 about here; there are no new template parameters for the nested
4529 error ("template specifiers not specified in declaration of %qD",
4534 parms = INNERMOST_TEMPLATE_PARMS (parms);
4535 tmpl_parms = DECL_INNERMOST_TEMPLATE_PARMS (tmpl);
4537 if (TREE_VEC_LENGTH (parms) != TREE_VEC_LENGTH (tmpl_parms))
4539 error ("redeclared with %d template parameter(s)",
4540 TREE_VEC_LENGTH (parms));
4541 inform (input_location, "previous declaration %q+D used %d template parameter(s)",
4542 tmpl, TREE_VEC_LENGTH (tmpl_parms));
4546 for (i = 0; i < TREE_VEC_LENGTH (tmpl_parms); ++i)
4553 if (TREE_VEC_ELT (tmpl_parms, i) == error_mark_node
4554 || TREE_VEC_ELT (parms, i) == error_mark_node)
4557 tmpl_parm = TREE_VALUE (TREE_VEC_ELT (tmpl_parms, i));
4558 parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
4559 tmpl_default = TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i));
4560 parm_default = TREE_PURPOSE (TREE_VEC_ELT (parms, i));
4562 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
4564 if (tmpl_parm != error_mark_node
4565 && (TREE_CODE (tmpl_parm) != TREE_CODE (parm)
4566 || (TREE_CODE (tmpl_parm) != TYPE_DECL
4567 && !same_type_p (TREE_TYPE (tmpl_parm), TREE_TYPE (parm)))
4568 || (TREE_CODE (tmpl_parm) != PARM_DECL
4569 && (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (tmpl_parm))
4570 != TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm))))
4571 || (TREE_CODE (tmpl_parm) == PARM_DECL
4572 && (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (tmpl_parm))
4573 != TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))))))
4575 error ("template parameter %q+#D", tmpl_parm);
4576 error ("redeclared here as %q#D", parm);
4580 if (tmpl_default != NULL_TREE && parm_default != NULL_TREE)
4582 /* We have in [temp.param]:
4584 A template-parameter may not be given default arguments
4585 by two different declarations in the same scope. */
4586 error_at (input_location, "redefinition of default argument for %q#D", parm);
4587 inform (DECL_SOURCE_LOCATION (tmpl_parm),
4588 "original definition appeared here");
4592 if (parm_default != NULL_TREE)
4593 /* Update the previous template parameters (which are the ones
4594 that will really count) with the new default value. */
4595 TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i)) = parm_default;
4596 else if (tmpl_default != NULL_TREE)
4597 /* Update the new parameters, too; they'll be used as the
4598 parameters for any members. */
4599 TREE_PURPOSE (TREE_VEC_ELT (parms, i)) = tmpl_default;
4605 /* Simplify EXPR if it is a non-dependent expression. Returns the
4606 (possibly simplified) expression. */
4609 fold_non_dependent_expr (tree expr)
4611 if (expr == NULL_TREE)
4614 /* If we're in a template, but EXPR isn't value dependent, simplify
4615 it. We're supposed to treat:
4617 template <typename T> void f(T[1 + 1]);
4618 template <typename T> void f(T[2]);
4620 as two declarations of the same function, for example. */
4621 if (processing_template_decl
4622 && !type_dependent_expression_p (expr)
4623 && !value_dependent_expression_p (expr))
4625 HOST_WIDE_INT saved_processing_template_decl;
4627 saved_processing_template_decl = processing_template_decl;
4628 processing_template_decl = 0;
4629 expr = tsubst_copy_and_build (expr,
4632 /*in_decl=*/NULL_TREE,
4633 /*function_p=*/false,
4634 /*integral_constant_expression_p=*/true);
4635 processing_template_decl = saved_processing_template_decl;
4640 /* EXPR is an expression which is used in a constant-expression context.
4641 For instance, it could be a VAR_DECL with a constant initializer.
4642 Extract the innermost constant expression.
4644 This is basically a more powerful version of
4645 integral_constant_value, which can be used also in templates where
4646 initializers can maintain a syntactic rather than semantic form
4647 (even if they are non-dependent, for access-checking purposes). */
4650 fold_decl_constant_value (tree expr)
4652 tree const_expr = expr;
4655 expr = fold_non_dependent_expr (const_expr);
4656 const_expr = integral_constant_value (expr);
4658 while (expr != const_expr);
4663 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
4664 must be a function or a pointer-to-function type, as specified
4665 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
4666 and check that the resulting function has external linkage. */
4669 convert_nontype_argument_function (tree type, tree expr)
4674 fn = instantiate_type (type, fns, tf_none);
4675 if (fn == error_mark_node)
4676 return error_mark_node;
4679 if (TREE_CODE (fn_no_ptr) == ADDR_EXPR)
4680 fn_no_ptr = TREE_OPERAND (fn_no_ptr, 0);
4681 if (TREE_CODE (fn_no_ptr) == BASELINK)
4682 fn_no_ptr = BASELINK_FUNCTIONS (fn_no_ptr);
4684 /* [temp.arg.nontype]/1
4686 A template-argument for a non-type, non-template template-parameter
4689 -- the address of an object or function with external linkage. */
4690 if (!DECL_EXTERNAL_LINKAGE_P (fn_no_ptr))
4692 error ("%qE is not a valid template argument for type %qT "
4693 "because function %qD has not external linkage",
4694 expr, type, fn_no_ptr);
4701 /* Subroutine of convert_nontype_argument.
4702 Check if EXPR of type TYPE is a valid pointer-to-member constant.
4703 Emit an error otherwise. */
4706 check_valid_ptrmem_cst_expr (tree type, tree expr)
4709 if (expr && (null_ptr_cst_p (expr) || TREE_CODE (expr) == PTRMEM_CST))
4711 error ("%qE is not a valid template argument for type %qT",
4713 error ("it must be a pointer-to-member of the form `&X::Y'");
4717 /* Attempt to convert the non-type template parameter EXPR to the
4718 indicated TYPE. If the conversion is successful, return the
4719 converted value. If the conversion is unsuccessful, return
4720 NULL_TREE if we issued an error message, or error_mark_node if we
4721 did not. We issue error messages for out-and-out bad template
4722 parameters, but not simply because the conversion failed, since we
4723 might be just trying to do argument deduction. Both TYPE and EXPR
4724 must be non-dependent.
4726 The conversion follows the special rules described in
4727 [temp.arg.nontype], and it is much more strict than an implicit
4730 This function is called twice for each template argument (see
4731 lookup_template_class for a more accurate description of this
4732 problem). This means that we need to handle expressions which
4733 are not valid in a C++ source, but can be created from the
4734 first call (for instance, casts to perform conversions). These
4735 hacks can go away after we fix the double coercion problem. */
4738 convert_nontype_argument (tree type, tree expr)
4742 /* Detect immediately string literals as invalid non-type argument.
4743 This special-case is not needed for correctness (we would easily
4744 catch this later), but only to provide better diagnostic for this
4745 common user mistake. As suggested by DR 100, we do not mention
4746 linkage issues in the diagnostic as this is not the point. */
4747 if (TREE_CODE (expr) == STRING_CST)
4749 error ("%qE is not a valid template argument for type %qT "
4750 "because string literals can never be used in this context",
4755 /* If we are in a template, EXPR may be non-dependent, but still
4756 have a syntactic, rather than semantic, form. For example, EXPR
4757 might be a SCOPE_REF, rather than the VAR_DECL to which the
4758 SCOPE_REF refers. Preserving the qualifying scope is necessary
4759 so that access checking can be performed when the template is
4760 instantiated -- but here we need the resolved form so that we can
4761 convert the argument. */
4762 expr = fold_non_dependent_expr (expr);
4763 if (error_operand_p (expr))
4764 return error_mark_node;
4765 expr_type = TREE_TYPE (expr);
4767 /* HACK: Due to double coercion, we can get a
4768 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
4769 which is the tree that we built on the first call (see
4770 below when coercing to reference to object or to reference to
4771 function). We just strip everything and get to the arg.
4772 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
4774 if (TREE_CODE (expr) == NOP_EXPR)
4776 if (TYPE_REF_OBJ_P (type) || TYPE_REFFN_P (type))
4778 /* ??? Maybe we could use convert_from_reference here, but we
4779 would need to relax its constraints because the NOP_EXPR
4780 could actually change the type to something more cv-qualified,
4781 and this is not folded by convert_from_reference. */
4782 tree addr = TREE_OPERAND (expr, 0);
4783 gcc_assert (TREE_CODE (expr_type) == REFERENCE_TYPE);
4784 gcc_assert (TREE_CODE (addr) == ADDR_EXPR);
4785 gcc_assert (TREE_CODE (TREE_TYPE (addr)) == POINTER_TYPE);
4786 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4787 (TREE_TYPE (expr_type),
4788 TREE_TYPE (TREE_TYPE (addr))));
4790 expr = TREE_OPERAND (addr, 0);
4791 expr_type = TREE_TYPE (expr);
4794 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
4795 parameter is a pointer to object, through decay and
4796 qualification conversion. Let's strip everything. */
4797 else if (TYPE_PTROBV_P (type))
4800 gcc_assert (TREE_CODE (expr) == ADDR_EXPR);
4801 gcc_assert (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE);
4802 /* Skip the ADDR_EXPR only if it is part of the decay for
4803 an array. Otherwise, it is part of the original argument
4804 in the source code. */
4805 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == ARRAY_TYPE)
4806 expr = TREE_OPERAND (expr, 0);
4807 expr_type = TREE_TYPE (expr);
4811 /* [temp.arg.nontype]/5, bullet 1
4813 For a non-type template-parameter of integral or enumeration type,
4814 integral promotions (_conv.prom_) and integral conversions
4815 (_conv.integral_) are applied. */
4816 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
4818 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (expr_type))
4819 return error_mark_node;
4821 expr = fold_decl_constant_value (expr);
4822 /* Notice that there are constant expressions like '4 % 0' which
4823 do not fold into integer constants. */
4824 if (TREE_CODE (expr) != INTEGER_CST)
4826 error ("%qE is not a valid template argument for type %qT "
4827 "because it is a non-constant expression", expr, type);
4831 /* At this point, an implicit conversion does what we want,
4832 because we already know that the expression is of integral
4834 expr = ocp_convert (type, expr, CONV_IMPLICIT, LOOKUP_PROTECT);
4835 if (expr == error_mark_node)
4836 return error_mark_node;
4838 /* Conversion was allowed: fold it to a bare integer constant. */
4841 /* [temp.arg.nontype]/5, bullet 2
4843 For a non-type template-parameter of type pointer to object,
4844 qualification conversions (_conv.qual_) and the array-to-pointer
4845 conversion (_conv.array_) are applied. */
4846 else if (TYPE_PTROBV_P (type))
4848 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
4850 A template-argument for a non-type, non-template template-parameter
4851 shall be one of: [...]
4853 -- the name of a non-type template-parameter;
4854 -- the address of an object or function with external linkage, [...]
4855 expressed as "& id-expression" where the & is optional if the name
4856 refers to a function or array, or if the corresponding
4857 template-parameter is a reference.
4859 Here, we do not care about functions, as they are invalid anyway
4860 for a parameter of type pointer-to-object. */
4862 if (DECL_P (expr) && DECL_TEMPLATE_PARM_P (expr))
4863 /* Non-type template parameters are OK. */
4865 else if (TREE_CODE (expr) != ADDR_EXPR
4866 && TREE_CODE (expr_type) != ARRAY_TYPE)
4868 if (TREE_CODE (expr) == VAR_DECL)
4870 error ("%qD is not a valid template argument "
4871 "because %qD is a variable, not the address of "
4876 /* Other values, like integer constants, might be valid
4877 non-type arguments of some other type. */
4878 return error_mark_node;
4884 decl = ((TREE_CODE (expr) == ADDR_EXPR)
4885 ? TREE_OPERAND (expr, 0) : expr);
4886 if (TREE_CODE (decl) != VAR_DECL)
4888 error ("%qE is not a valid template argument of type %qT "
4889 "because %qE is not a variable",
4893 else if (!DECL_EXTERNAL_LINKAGE_P (decl))
4895 error ("%qE is not a valid template argument of type %qT "
4896 "because %qD does not have external linkage",
4902 expr = decay_conversion (expr);
4903 if (expr == error_mark_node)
4904 return error_mark_node;
4906 expr = perform_qualification_conversions (type, expr);
4907 if (expr == error_mark_node)
4908 return error_mark_node;
4910 /* [temp.arg.nontype]/5, bullet 3
4912 For a non-type template-parameter of type reference to object, no
4913 conversions apply. The type referred to by the reference may be more
4914 cv-qualified than the (otherwise identical) type of the
4915 template-argument. The template-parameter is bound directly to the
4916 template-argument, which must be an lvalue. */
4917 else if (TYPE_REF_OBJ_P (type))
4919 if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type),
4921 return error_mark_node;
4923 if (!at_least_as_qualified_p (TREE_TYPE (type), expr_type))
4925 error ("%qE is not a valid template argument for type %qT "
4926 "because of conflicts in cv-qualification", expr, type);
4930 if (!real_lvalue_p (expr))
4932 error ("%qE is not a valid template argument for type %qT "
4933 "because it is not an lvalue", expr, type);
4937 /* [temp.arg.nontype]/1
4939 A template-argument for a non-type, non-template template-parameter
4940 shall be one of: [...]
4942 -- the address of an object or function with external linkage. */
4943 if (TREE_CODE (expr) == INDIRECT_REF
4944 && TYPE_REF_OBJ_P (TREE_TYPE (TREE_OPERAND (expr, 0))))
4946 expr = TREE_OPERAND (expr, 0);
4949 error ("%q#D is not a valid template argument for type %qT "
4950 "because a reference variable does not have a constant "
4951 "address", expr, type);
4958 error ("%qE is not a valid template argument for type %qT "
4959 "because it is not an object with external linkage",
4964 if (!DECL_EXTERNAL_LINKAGE_P (expr))
4966 error ("%qE is not a valid template argument for type %qT "
4967 "because object %qD has not external linkage",
4972 expr = build_nop (type, build_address (expr));
4974 /* [temp.arg.nontype]/5, bullet 4
4976 For a non-type template-parameter of type pointer to function, only
4977 the function-to-pointer conversion (_conv.func_) is applied. If the
4978 template-argument represents a set of overloaded functions (or a
4979 pointer to such), the matching function is selected from the set
4981 else if (TYPE_PTRFN_P (type))
4983 /* If the argument is a template-id, we might not have enough
4984 context information to decay the pointer. */
4985 if (!type_unknown_p (expr_type))
4987 expr = decay_conversion (expr);
4988 if (expr == error_mark_node)
4989 return error_mark_node;
4992 expr = convert_nontype_argument_function (type, expr);
4993 if (!expr || expr == error_mark_node)
4996 if (TREE_CODE (expr) != ADDR_EXPR)
4998 error ("%qE is not a valid template argument for type %qT", expr, type);
4999 error ("it must be the address of a function with external linkage");
5003 /* [temp.arg.nontype]/5, bullet 5
5005 For a non-type template-parameter of type reference to function, no
5006 conversions apply. If the template-argument represents a set of
5007 overloaded functions, the matching function is selected from the set
5009 else if (TYPE_REFFN_P (type))
5011 if (TREE_CODE (expr) == ADDR_EXPR)
5013 error ("%qE is not a valid template argument for type %qT "
5014 "because it is a pointer", expr, type);
5015 inform (input_location, "try using %qE instead", TREE_OPERAND (expr, 0));
5019 expr = convert_nontype_argument_function (TREE_TYPE (type), expr);
5020 if (!expr || expr == error_mark_node)
5023 expr = build_nop (type, build_address (expr));
5025 /* [temp.arg.nontype]/5, bullet 6
5027 For a non-type template-parameter of type pointer to member function,
5028 no conversions apply. If the template-argument represents a set of
5029 overloaded member functions, the matching member function is selected
5030 from the set (_over.over_). */
5031 else if (TYPE_PTRMEMFUNC_P (type))
5033 expr = instantiate_type (type, expr, tf_none);
5034 if (expr == error_mark_node)
5035 return error_mark_node;
5037 /* [temp.arg.nontype] bullet 1 says the pointer to member
5038 expression must be a pointer-to-member constant. */
5039 if (!check_valid_ptrmem_cst_expr (type, expr))
5040 return error_mark_node;
5042 /* There is no way to disable standard conversions in
5043 resolve_address_of_overloaded_function (called by
5044 instantiate_type). It is possible that the call succeeded by
5045 converting &B::I to &D::I (where B is a base of D), so we need
5046 to reject this conversion here.
5048 Actually, even if there was a way to disable standard conversions,
5049 it would still be better to reject them here so that we can
5050 provide a superior diagnostic. */
5051 if (!same_type_p (TREE_TYPE (expr), type))
5053 /* Make sure we are just one standard conversion off. */
5054 gcc_assert (can_convert (type, TREE_TYPE (expr)));
5055 error ("%qE is not a valid template argument for type %qT "
5056 "because it is of type %qT", expr, type,
5058 inform (input_location, "standard conversions are not allowed in this context");
5062 /* [temp.arg.nontype]/5, bullet 7
5064 For a non-type template-parameter of type pointer to data member,
5065 qualification conversions (_conv.qual_) are applied. */
5066 else if (TYPE_PTRMEM_P (type))
5068 /* [temp.arg.nontype] bullet 1 says the pointer to member
5069 expression must be a pointer-to-member constant. */
5070 if (!check_valid_ptrmem_cst_expr (type, expr))
5071 return error_mark_node;
5073 expr = perform_qualification_conversions (type, expr);
5074 if (expr == error_mark_node)
5077 /* A template non-type parameter must be one of the above. */
5081 /* Sanity check: did we actually convert the argument to the
5083 gcc_assert (same_type_p (type, TREE_TYPE (expr)));
5087 /* Subroutine of coerce_template_template_parms, which returns 1 if
5088 PARM_PARM and ARG_PARM match using the rule for the template
5089 parameters of template template parameters. Both PARM and ARG are
5090 template parameters; the rest of the arguments are the same as for
5091 coerce_template_template_parms.
5094 coerce_template_template_parm (tree parm,
5096 tsubst_flags_t complain,
5100 if (arg == NULL_TREE || arg == error_mark_node
5101 || parm == NULL_TREE || parm == error_mark_node)
5104 if (TREE_CODE (arg) != TREE_CODE (parm))
5107 switch (TREE_CODE (parm))
5110 /* We encounter instantiations of templates like
5111 template <template <template <class> class> class TT>
5114 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
5115 tree argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
5117 if (!coerce_template_template_parms
5118 (parmparm, argparm, complain, in_decl, outer_args))
5124 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (arg))
5125 && !TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
5126 /* Argument is a parameter pack but parameter is not. */
5131 /* The tsubst call is used to handle cases such as
5133 template <int> class C {};
5134 template <class T, template <T> class TT> class D {};
5137 i.e. the parameter list of TT depends on earlier parameters. */
5138 if (!uses_template_parms (TREE_TYPE (arg))
5140 (tsubst (TREE_TYPE (parm), outer_args, complain, in_decl),
5144 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (arg))
5145 && !TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
5146 /* Argument is a parameter pack but parameter is not. */
5159 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
5160 template template parameters. Both PARM_PARMS and ARG_PARMS are
5161 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
5164 Consider the example:
5165 template <class T> class A;
5166 template<template <class U> class TT> class B;
5168 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
5169 the parameters to A, and OUTER_ARGS contains A. */
5172 coerce_template_template_parms (tree parm_parms,
5174 tsubst_flags_t complain,
5178 int nparms, nargs, i;
5182 gcc_assert (TREE_CODE (parm_parms) == TREE_VEC);
5183 gcc_assert (TREE_CODE (arg_parms) == TREE_VEC);
5185 nparms = TREE_VEC_LENGTH (parm_parms);
5186 nargs = TREE_VEC_LENGTH (arg_parms);
5188 /* Determine whether we have a parameter pack at the end of the
5189 template template parameter's template parameter list. */
5190 if (TREE_VEC_ELT (parm_parms, nparms - 1) != error_mark_node)
5192 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, nparms - 1));
5194 if (parm == error_mark_node)
5197 switch (TREE_CODE (parm))
5201 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
5206 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
5216 && !(variadic_p && nargs >= nparms - 1))
5219 /* Check all of the template parameters except the parameter pack at
5220 the end (if any). */
5221 for (i = 0; i < nparms - variadic_p; ++i)
5223 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node
5224 || TREE_VEC_ELT (arg_parms, i) == error_mark_node)
5227 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
5228 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
5230 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
5238 /* Check each of the template parameters in the template
5239 argument against the template parameter pack at the end of
5240 the template template parameter. */
5241 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node)
5244 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
5246 for (; i < nargs; ++i)
5248 if (TREE_VEC_ELT (arg_parms, i) == error_mark_node)
5251 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
5253 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
5262 /* Verifies that the deduced template arguments (in TARGS) for the
5263 template template parameters (in TPARMS) represent valid bindings,
5264 by comparing the template parameter list of each template argument
5265 to the template parameter list of its corresponding template
5266 template parameter, in accordance with DR150. This
5267 routine can only be called after all template arguments have been
5268 deduced. It will return TRUE if all of the template template
5269 parameter bindings are okay, FALSE otherwise. */
5271 template_template_parm_bindings_ok_p (tree tparms, tree targs)
5273 int i, ntparms = TREE_VEC_LENGTH (tparms);
5276 /* We're dealing with template parms in this process. */
5277 ++processing_template_decl;
5279 targs = INNERMOST_TEMPLATE_ARGS (targs);
5281 for (i = 0; i < ntparms; ++i)
5283 tree tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
5284 tree targ = TREE_VEC_ELT (targs, i);
5286 if (TREE_CODE (tparm) == TEMPLATE_DECL && targ)
5288 tree packed_args = NULL_TREE;
5291 if (ARGUMENT_PACK_P (targ))
5293 /* Look inside the argument pack. */
5294 packed_args = ARGUMENT_PACK_ARGS (targ);
5295 len = TREE_VEC_LENGTH (packed_args);
5298 for (idx = 0; idx < len; ++idx)
5300 tree targ_parms = NULL_TREE;
5303 /* Extract the next argument from the argument
5305 targ = TREE_VEC_ELT (packed_args, idx);
5307 if (PACK_EXPANSION_P (targ))
5308 /* Look at the pattern of the pack expansion. */
5309 targ = PACK_EXPANSION_PATTERN (targ);
5311 /* Extract the template parameters from the template
5313 if (TREE_CODE (targ) == TEMPLATE_DECL)
5314 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (targ);
5315 else if (TREE_CODE (targ) == TEMPLATE_TEMPLATE_PARM)
5316 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (TYPE_NAME (targ));
5318 /* Verify that we can coerce the template template
5319 parameters from the template argument to the template
5320 parameter. This requires an exact match. */
5322 && !coerce_template_template_parms
5323 (DECL_INNERMOST_TEMPLATE_PARMS (tparm),
5338 --processing_template_decl;
5342 /* Convert the indicated template ARG as necessary to match the
5343 indicated template PARM. Returns the converted ARG, or
5344 error_mark_node if the conversion was unsuccessful. Error and
5345 warning messages are issued under control of COMPLAIN. This
5346 conversion is for the Ith parameter in the parameter list. ARGS is
5347 the full set of template arguments deduced so far. */
5350 convert_template_argument (tree parm,
5353 tsubst_flags_t complain,
5359 int is_type, requires_type, is_tmpl_type, requires_tmpl_type;
5361 if (TREE_CODE (arg) == TREE_LIST
5362 && TREE_CODE (TREE_VALUE (arg)) == OFFSET_REF)
5364 /* The template argument was the name of some
5365 member function. That's usually
5366 invalid, but static members are OK. In any
5367 case, grab the underlying fields/functions
5368 and issue an error later if required. */
5369 orig_arg = TREE_VALUE (arg);
5370 TREE_TYPE (arg) = unknown_type_node;
5375 requires_tmpl_type = TREE_CODE (parm) == TEMPLATE_DECL;
5376 requires_type = (TREE_CODE (parm) == TYPE_DECL
5377 || requires_tmpl_type);
5379 /* When determining whether an argument pack expansion is a template,
5380 look at the pattern. */
5381 if (TREE_CODE (arg) == TYPE_PACK_EXPANSION)
5382 arg = PACK_EXPANSION_PATTERN (arg);
5384 /* Deal with an injected-class-name used as a template template arg. */
5385 if (requires_tmpl_type && CLASS_TYPE_P (arg))
5387 tree t = maybe_get_template_decl_from_type_decl (TYPE_NAME (arg));
5388 if (TREE_CODE (t) == TEMPLATE_DECL)
5390 if (complain & tf_warning_or_error)
5391 pedwarn (input_location, OPT_pedantic, "injected-class-name %qD"
5392 " used as template template argument", TYPE_NAME (arg));
5393 else if (flag_pedantic_errors)
5401 ((TREE_CODE (arg) == TEMPLATE_DECL
5402 && TREE_CODE (DECL_TEMPLATE_RESULT (arg)) == TYPE_DECL)
5403 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
5404 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE);
5407 && (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
5408 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE))
5409 arg = TYPE_STUB_DECL (arg);
5411 is_type = TYPE_P (arg) || is_tmpl_type;
5413 if (requires_type && ! is_type && TREE_CODE (arg) == SCOPE_REF
5414 && TREE_CODE (TREE_OPERAND (arg, 0)) == TEMPLATE_TYPE_PARM)
5416 permerror (input_location, "to refer to a type member of a template parameter, "
5417 "use %<typename %E%>", orig_arg);
5419 orig_arg = make_typename_type (TREE_OPERAND (arg, 0),
5420 TREE_OPERAND (arg, 1),
5422 complain & tf_error);
5426 if (is_type != requires_type)
5430 if (complain & tf_error)
5432 error ("type/value mismatch at argument %d in template "
5433 "parameter list for %qD",
5436 error (" expected a constant of type %qT, got %qT",
5438 (DECL_P (arg) ? DECL_NAME (arg) : orig_arg));
5439 else if (requires_tmpl_type)
5440 error (" expected a class template, got %qE", orig_arg);
5442 error (" expected a type, got %qE", orig_arg);
5445 return error_mark_node;
5447 if (is_tmpl_type ^ requires_tmpl_type)
5449 if (in_decl && (complain & tf_error))
5451 error ("type/value mismatch at argument %d in template "
5452 "parameter list for %qD",
5455 error (" expected a type, got %qT", DECL_NAME (arg));
5457 error (" expected a class template, got %qT", orig_arg);
5459 return error_mark_node;
5464 if (requires_tmpl_type)
5466 if (TREE_CODE (TREE_TYPE (arg)) == UNBOUND_CLASS_TEMPLATE)
5467 /* The number of argument required is not known yet.
5468 Just accept it for now. */
5469 val = TREE_TYPE (arg);
5472 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
5475 argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
5477 if (coerce_template_template_parms (parmparm, argparm,
5483 /* TEMPLATE_TEMPLATE_PARM node is preferred over
5485 if (val != error_mark_node)
5487 if (DECL_TEMPLATE_TEMPLATE_PARM_P (val))
5488 val = TREE_TYPE (val);
5489 if (TREE_CODE (orig_arg) == TYPE_PACK_EXPANSION)
5490 val = make_pack_expansion (val);
5495 if (in_decl && (complain & tf_error))
5497 error ("type/value mismatch at argument %d in "
5498 "template parameter list for %qD",
5500 error (" expected a template of type %qD, got %qT",
5504 val = error_mark_node;
5510 /* We only form one instance of each template specialization.
5511 Therefore, if we use a non-canonical variant (i.e., a
5512 typedef), any future messages referring to the type will use
5513 the typedef, which is confusing if those future uses do not
5514 themselves also use the typedef. */
5516 val = strip_typedefs (val);
5520 tree t = tsubst (TREE_TYPE (parm), args, complain, in_decl);
5522 if (invalid_nontype_parm_type_p (t, complain))
5523 return error_mark_node;
5525 if (template_parameter_pack_p (parm) && ARGUMENT_PACK_P (orig_arg))
5527 if (same_type_p (t, TREE_TYPE (orig_arg)))
5531 /* Not sure if this is reachable, but it doesn't hurt
5533 error ("type mismatch in nontype parameter pack");
5534 val = error_mark_node;
5537 else if (!uses_template_parms (orig_arg) && !uses_template_parms (t))
5538 /* We used to call digest_init here. However, digest_init
5539 will report errors, which we don't want when complain
5540 is zero. More importantly, digest_init will try too
5541 hard to convert things: for example, `0' should not be
5542 converted to pointer type at this point according to
5543 the standard. Accepting this is not merely an
5544 extension, since deciding whether or not these
5545 conversions can occur is part of determining which
5546 function template to call, or whether a given explicit
5547 argument specification is valid. */
5548 val = convert_nontype_argument (t, orig_arg);
5552 if (val == NULL_TREE)
5553 val = error_mark_node;
5554 else if (val == error_mark_node && (complain & tf_error))
5555 error ("could not convert template argument %qE to %qT", orig_arg, t);
5561 /* Coerces the remaining template arguments in INNER_ARGS (from
5562 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
5563 Returns the coerced argument pack. PARM_IDX is the position of this
5564 parameter in the template parameter list. ARGS is the original
5565 template argument list. */
5567 coerce_template_parameter_pack (tree parms,
5575 tsubst_flags_t complain)
5577 tree parm = TREE_VEC_ELT (parms, parm_idx);
5578 int nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
5581 tree packed_types = NULL_TREE;
5583 if (arg_idx > nargs)
5586 packed_args = make_tree_vec (nargs - arg_idx);
5588 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL
5589 && uses_parameter_packs (TREE_TYPE (TREE_VALUE (parm))))
5591 /* When the template parameter is a non-type template
5592 parameter pack whose type uses parameter packs, we need
5593 to look at each of the template arguments
5594 separately. Build a vector of the types for these
5595 non-type template parameters in PACKED_TYPES. */
5597 = make_pack_expansion (TREE_TYPE (TREE_VALUE (parm)));
5598 packed_types = tsubst_pack_expansion (expansion, args,
5601 if (packed_types == error_mark_node)
5602 return error_mark_node;
5604 /* Check that we have the right number of arguments. */
5606 && !PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx))
5607 && nargs - arg_idx != TREE_VEC_LENGTH (packed_types))
5610 = TREE_VEC_LENGTH (parms) - 1 + TREE_VEC_LENGTH (packed_types);
5611 error ("wrong number of template arguments (%d, should be %d)",
5612 nargs, needed_parms);
5613 return error_mark_node;
5616 /* If we aren't able to check the actual arguments now
5617 (because they haven't been expanded yet), we can at least
5618 verify that all of the types used for the non-type
5619 template parameter pack are, in fact, valid for non-type
5620 template parameters. */
5622 && PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx)))
5624 int j, len = TREE_VEC_LENGTH (packed_types);
5625 for (j = 0; j < len; ++j)
5627 tree t = TREE_VEC_ELT (packed_types, j);
5628 if (invalid_nontype_parm_type_p (t, complain))
5629 return error_mark_node;
5634 /* Convert the remaining arguments, which will be a part of the
5635 parameter pack "parm". */
5636 for (; arg_idx < nargs; ++arg_idx)
5638 tree arg = TREE_VEC_ELT (inner_args, arg_idx);
5639 tree actual_parm = TREE_VALUE (parm);
5641 if (packed_types && !PACK_EXPANSION_P (arg))
5643 /* When we have a vector of types (corresponding to the
5644 non-type template parameter pack that uses parameter
5645 packs in its type, as mention above), and the
5646 argument is not an expansion (which expands to a
5647 currently unknown number of arguments), clone the
5648 parm and give it the next type in PACKED_TYPES. */
5649 actual_parm = copy_node (actual_parm);
5650 TREE_TYPE (actual_parm) =
5651 TREE_VEC_ELT (packed_types, arg_idx - parm_idx);
5654 if (arg != error_mark_node)
5655 arg = convert_template_argument (actual_parm,
5656 arg, new_args, complain, parm_idx,
5658 if (arg == error_mark_node)
5660 TREE_VEC_ELT (packed_args, arg_idx - parm_idx) = arg;
5663 if (TREE_CODE (TREE_VALUE (parm)) == TYPE_DECL
5664 || TREE_CODE (TREE_VALUE (parm)) == TEMPLATE_DECL)
5665 argument_pack = cxx_make_type (TYPE_ARGUMENT_PACK);
5668 argument_pack = make_node (NONTYPE_ARGUMENT_PACK);
5669 TREE_TYPE (argument_pack)
5670 = tsubst (TREE_TYPE (TREE_VALUE (parm)), new_args, complain, in_decl);
5671 TREE_CONSTANT (argument_pack) = 1;
5674 SET_ARGUMENT_PACK_ARGS (argument_pack, packed_args);
5675 return argument_pack;
5678 /* Convert all template arguments to their appropriate types, and
5679 return a vector containing the innermost resulting template
5680 arguments. If any error occurs, return error_mark_node. Error and
5681 warning messages are issued under control of COMPLAIN.
5683 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
5684 for arguments not specified in ARGS. Otherwise, if
5685 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
5686 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
5687 USE_DEFAULT_ARGS is false, then all arguments must be specified in
5691 coerce_template_parms (tree parms,
5694 tsubst_flags_t complain,
5695 bool require_all_args,
5696 bool use_default_args)
5698 int nparms, nargs, parm_idx, arg_idx, lost = 0;
5701 tree new_inner_args;
5702 int saved_unevaluated_operand;
5703 int saved_inhibit_evaluation_warnings;
5705 /* When used as a boolean value, indicates whether this is a
5706 variadic template parameter list. Since it's an int, we can also
5707 subtract it from nparms to get the number of non-variadic
5711 nparms = TREE_VEC_LENGTH (parms);
5713 /* Determine if there are any parameter packs. */
5714 for (parm_idx = 0; parm_idx < nparms; ++parm_idx)
5716 tree tparm = TREE_VALUE (TREE_VEC_ELT (parms, parm_idx));
5717 if (template_parameter_pack_p (tparm))
5721 inner_args = INNERMOST_TEMPLATE_ARGS (args);
5722 /* If there are 0 or 1 parameter packs, we need to expand any argument
5723 packs so that we can deduce a parameter pack from some non-packed args
5724 followed by an argument pack, as in variadic85.C. If there are more
5725 than that, we need to leave argument packs intact so the arguments are
5726 assigned to the right parameter packs. This should only happen when
5727 dealing with a nested class inside a partial specialization of a class
5728 template, as in variadic92.C. */
5729 if (variadic_p <= 1)
5730 inner_args = expand_template_argument_pack (inner_args);
5732 nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
5733 if ((nargs > nparms && !variadic_p)
5734 || (nargs < nparms - variadic_p
5736 && (!use_default_args
5737 || (TREE_VEC_ELT (parms, nargs) != error_mark_node
5738 && !TREE_PURPOSE (TREE_VEC_ELT (parms, nargs))))))
5740 if (complain & tf_error)
5742 const char *or_more = "";
5745 or_more = " or more";
5749 error ("wrong number of template arguments (%d, should be %d%s)",
5750 nargs, nparms, or_more);
5753 error ("provided for %q+D", in_decl);
5756 return error_mark_node;
5759 /* We need to evaluate the template arguments, even though this
5760 template-id may be nested within a "sizeof". */
5761 saved_unevaluated_operand = cp_unevaluated_operand;
5762 cp_unevaluated_operand = 0;
5763 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
5764 c_inhibit_evaluation_warnings = 0;
5765 new_inner_args = make_tree_vec (nparms);
5766 new_args = add_outermost_template_args (args, new_inner_args);
5767 for (parm_idx = 0, arg_idx = 0; parm_idx < nparms; parm_idx++, arg_idx++)
5772 /* Get the Ith template parameter. */
5773 parm = TREE_VEC_ELT (parms, parm_idx);
5775 if (parm == error_mark_node)
5777 TREE_VEC_ELT (new_inner_args, arg_idx) = error_mark_node;
5781 /* Calculate the next argument. */
5782 if (arg_idx < nargs)
5783 arg = TREE_VEC_ELT (inner_args, arg_idx);
5787 if (template_parameter_pack_p (TREE_VALUE (parm))
5788 && !(arg && ARGUMENT_PACK_P (arg)))
5790 /* All remaining arguments will be placed in the
5791 template parameter pack PARM. */
5792 arg = coerce_template_parameter_pack (parms, parm_idx, args,
5793 inner_args, arg_idx,
5797 /* Store this argument. */
5798 if (arg == error_mark_node)
5800 TREE_VEC_ELT (new_inner_args, parm_idx) = arg;
5802 /* We are done with all of the arguments. */
5809 if (PACK_EXPANSION_P (arg))
5811 if (complain & tf_error)
5813 /* FIXME this restriction was removed by N2555; see
5815 /* If ARG is a pack expansion, but PARM is not a
5816 template parameter pack (if it were, we would have
5817 handled it above), we're trying to expand into a
5818 fixed-length argument list. */
5819 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
5820 sorry ("cannot expand %<%E%> into a fixed-length "
5821 "argument list", arg);
5823 sorry ("cannot expand %<%T%> into a fixed-length "
5824 "argument list", arg);
5826 return error_mark_node;
5829 else if (require_all_args)
5830 /* There must be a default arg in this case. */
5831 arg = tsubst_template_arg (TREE_PURPOSE (parm), new_args,
5836 if (arg == error_mark_node)
5838 if (complain & tf_error)
5839 error ("template argument %d is invalid", arg_idx + 1);
5842 /* This only occurs if there was an error in the template
5843 parameter list itself (which we would already have
5844 reported) that we are trying to recover from, e.g., a class
5845 template with a parameter list such as
5846 template<typename..., typename>. */
5847 return error_mark_node;
5849 arg = convert_template_argument (TREE_VALUE (parm),
5850 arg, new_args, complain,
5853 if (arg == error_mark_node)
5855 TREE_VEC_ELT (new_inner_args, arg_idx) = arg;
5857 cp_unevaluated_operand = saved_unevaluated_operand;
5858 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
5861 return error_mark_node;
5863 return new_inner_args;
5866 /* Returns 1 if template args OT and NT are equivalent. */
5869 template_args_equal (tree ot, tree nt)
5874 if (TREE_CODE (nt) == TREE_VEC)
5875 /* For member templates */
5876 return TREE_CODE (ot) == TREE_VEC && comp_template_args (ot, nt);
5877 else if (PACK_EXPANSION_P (ot))
5878 return PACK_EXPANSION_P (nt)
5879 && template_args_equal (PACK_EXPANSION_PATTERN (ot),
5880 PACK_EXPANSION_PATTERN (nt));
5881 else if (ARGUMENT_PACK_P (ot))
5886 if (!ARGUMENT_PACK_P (nt))
5889 opack = ARGUMENT_PACK_ARGS (ot);
5890 npack = ARGUMENT_PACK_ARGS (nt);
5891 len = TREE_VEC_LENGTH (opack);
5892 if (TREE_VEC_LENGTH (npack) != len)
5894 for (i = 0; i < len; ++i)
5895 if (!template_args_equal (TREE_VEC_ELT (opack, i),
5896 TREE_VEC_ELT (npack, i)))
5900 else if (ot && TREE_CODE (ot) == ARGUMENT_PACK_SELECT)
5902 /* We get here probably because we are in the middle of substituting
5903 into the pattern of a pack expansion. In that case the
5904 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
5905 interested in. So we want to use the initial pack argument for
5907 ot = ARGUMENT_PACK_SELECT_FROM_PACK (ot);
5908 if (nt && TREE_CODE (nt) == ARGUMENT_PACK_SELECT)
5909 nt = ARGUMENT_PACK_SELECT_FROM_PACK (nt);
5910 return template_args_equal (ot, nt);
5912 else if (TYPE_P (nt))
5913 return TYPE_P (ot) && same_type_p (ot, nt);
5914 else if (TREE_CODE (ot) == TREE_VEC || TYPE_P (ot))
5917 return cp_tree_equal (ot, nt);
5920 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
5921 of template arguments. Returns 0 otherwise. */
5924 comp_template_args (tree oldargs, tree newargs)
5928 if (TREE_VEC_LENGTH (oldargs) != TREE_VEC_LENGTH (newargs))
5931 for (i = 0; i < TREE_VEC_LENGTH (oldargs); ++i)
5933 tree nt = TREE_VEC_ELT (newargs, i);
5934 tree ot = TREE_VEC_ELT (oldargs, i);
5936 if (! template_args_equal (ot, nt))
5943 add_pending_template (tree d)
5945 tree ti = (TYPE_P (d)
5946 ? CLASSTYPE_TEMPLATE_INFO (d)
5947 : DECL_TEMPLATE_INFO (d));
5948 struct pending_template *pt;
5951 if (TI_PENDING_TEMPLATE_FLAG (ti))
5954 /* We are called both from instantiate_decl, where we've already had a
5955 tinst_level pushed, and instantiate_template, where we haven't.
5957 level = !current_tinst_level || current_tinst_level->decl != d;
5960 push_tinst_level (d);
5962 pt = GGC_NEW (struct pending_template);
5964 pt->tinst = current_tinst_level;
5965 if (last_pending_template)
5966 last_pending_template->next = pt;
5968 pending_templates = pt;
5970 last_pending_template = pt;
5972 TI_PENDING_TEMPLATE_FLAG (ti) = 1;
5979 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
5980 ARGLIST. Valid choices for FNS are given in the cp-tree.def
5981 documentation for TEMPLATE_ID_EXPR. */
5984 lookup_template_function (tree fns, tree arglist)
5988 if (fns == error_mark_node || arglist == error_mark_node)
5989 return error_mark_node;
5991 gcc_assert (!arglist || TREE_CODE (arglist) == TREE_VEC);
5992 gcc_assert (fns && (is_overloaded_fn (fns)
5993 || TREE_CODE (fns) == IDENTIFIER_NODE));
5995 if (BASELINK_P (fns))
5997 BASELINK_FUNCTIONS (fns) = build2 (TEMPLATE_ID_EXPR,
5999 BASELINK_FUNCTIONS (fns),
6004 type = TREE_TYPE (fns);
6005 if (TREE_CODE (fns) == OVERLOAD || !type)
6006 type = unknown_type_node;
6008 return build2 (TEMPLATE_ID_EXPR, type, fns, arglist);
6011 /* Within the scope of a template class S<T>, the name S gets bound
6012 (in build_self_reference) to a TYPE_DECL for the class, not a
6013 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
6014 or one of its enclosing classes, and that type is a template,
6015 return the associated TEMPLATE_DECL. Otherwise, the original
6018 Also handle the case when DECL is a TREE_LIST of ambiguous
6019 injected-class-names from different bases. */
6022 maybe_get_template_decl_from_type_decl (tree decl)
6024 if (decl == NULL_TREE)
6027 /* DR 176: A lookup that finds an injected-class-name (10.2
6028 [class.member.lookup]) can result in an ambiguity in certain cases
6029 (for example, if it is found in more than one base class). If all of
6030 the injected-class-names that are found refer to specializations of
6031 the same class template, and if the name is followed by a
6032 template-argument-list, the reference refers to the class template
6033 itself and not a specialization thereof, and is not ambiguous. */
6034 if (TREE_CODE (decl) == TREE_LIST)
6036 tree t, tmpl = NULL_TREE;
6037 for (t = decl; t; t = TREE_CHAIN (t))
6039 tree elt = maybe_get_template_decl_from_type_decl (TREE_VALUE (t));
6042 else if (tmpl != elt)
6045 if (tmpl && t == NULL_TREE)
6051 return (decl != NULL_TREE
6052 && DECL_SELF_REFERENCE_P (decl)
6053 && CLASSTYPE_TEMPLATE_INFO (TREE_TYPE (decl)))
6054 ? CLASSTYPE_TI_TEMPLATE (TREE_TYPE (decl)) : decl;
6057 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
6058 parameters, find the desired type.
6060 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
6062 IN_DECL, if non-NULL, is the template declaration we are trying to
6065 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
6066 the class we are looking up.
6068 Issue error and warning messages under control of COMPLAIN.
6070 If the template class is really a local class in a template
6071 function, then the FUNCTION_CONTEXT is the function in which it is
6074 ??? Note that this function is currently called *twice* for each
6075 template-id: the first time from the parser, while creating the
6076 incomplete type (finish_template_type), and the second type during the
6077 real instantiation (instantiate_template_class). This is surely something
6078 that we want to avoid. It also causes some problems with argument
6079 coercion (see convert_nontype_argument for more information on this). */
6082 lookup_template_class (tree d1,
6087 tsubst_flags_t complain)
6089 tree templ = NULL_TREE, parmlist;
6096 timevar_push (TV_NAME_LOOKUP);
6098 if (TREE_CODE (d1) == IDENTIFIER_NODE)
6100 tree value = innermost_non_namespace_value (d1);
6101 if (value && DECL_TEMPLATE_TEMPLATE_PARM_P (value))
6106 push_decl_namespace (context);
6107 templ = lookup_name (d1);
6108 templ = maybe_get_template_decl_from_type_decl (templ);
6110 pop_decl_namespace ();
6113 context = DECL_CONTEXT (templ);
6115 else if (TREE_CODE (d1) == TYPE_DECL && MAYBE_CLASS_TYPE_P (TREE_TYPE (d1)))
6117 tree type = TREE_TYPE (d1);
6119 /* If we are declaring a constructor, say A<T>::A<T>, we will get
6120 an implicit typename for the second A. Deal with it. */
6121 if (TREE_CODE (type) == TYPENAME_TYPE && TREE_TYPE (type))
6122 type = TREE_TYPE (type);
6124 if (CLASSTYPE_TEMPLATE_INFO (type))
6126 templ = CLASSTYPE_TI_TEMPLATE (type);
6127 d1 = DECL_NAME (templ);
6130 else if (TREE_CODE (d1) == ENUMERAL_TYPE
6131 || (TYPE_P (d1) && MAYBE_CLASS_TYPE_P (d1)))
6133 templ = TYPE_TI_TEMPLATE (d1);
6134 d1 = DECL_NAME (templ);
6136 else if (TREE_CODE (d1) == TEMPLATE_DECL
6137 && DECL_TEMPLATE_RESULT (d1)
6138 && TREE_CODE (DECL_TEMPLATE_RESULT (d1)) == TYPE_DECL)
6141 d1 = DECL_NAME (templ);
6142 context = DECL_CONTEXT (templ);
6145 /* Issue an error message if we didn't find a template. */
6148 if (complain & tf_error)
6149 error ("%qT is not a template", d1);
6150 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6153 if (TREE_CODE (templ) != TEMPLATE_DECL
6154 /* Make sure it's a user visible template, if it was named by
6156 || ((complain & tf_user) && !DECL_TEMPLATE_PARM_P (templ)
6157 && !PRIMARY_TEMPLATE_P (templ)))
6159 if (complain & tf_error)
6161 error ("non-template type %qT used as a template", d1);
6163 error ("for template declaration %q+D", in_decl);
6165 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6168 complain &= ~tf_user;
6170 if (DECL_TEMPLATE_TEMPLATE_PARM_P (templ))
6172 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
6173 template arguments */
6179 parmlist = DECL_INNERMOST_TEMPLATE_PARMS (templ);
6181 /* Consider an example where a template template parameter declared as
6183 template <class T, class U = std::allocator<T> > class TT
6185 The template parameter level of T and U are one level larger than
6186 of TT. To proper process the default argument of U, say when an
6187 instantiation `TT<int>' is seen, we need to build the full
6188 arguments containing {int} as the innermost level. Outer levels,
6189 available when not appearing as default template argument, can be
6190 obtained from the arguments of the enclosing template.
6192 Suppose that TT is later substituted with std::vector. The above
6193 instantiation is `TT<int, std::allocator<T> >' with TT at
6194 level 1, and T at level 2, while the template arguments at level 1
6195 becomes {std::vector} and the inner level 2 is {int}. */
6197 outer = DECL_CONTEXT (templ);
6199 outer = TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (outer)));
6200 else if (current_template_parms)
6201 /* This is an argument of the current template, so we haven't set
6202 DECL_CONTEXT yet. */
6203 outer = current_template_args ();
6206 arglist = add_to_template_args (outer, arglist);
6208 arglist2 = coerce_template_parms (parmlist, arglist, templ,
6210 /*require_all_args=*/true,
6211 /*use_default_args=*/true);
6212 if (arglist2 == error_mark_node
6213 || (!uses_template_parms (arglist2)
6214 && check_instantiated_args (templ, arglist2, complain)))
6215 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6217 parm = bind_template_template_parm (TREE_TYPE (templ), arglist2);
6218 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, parm);
6222 tree template_type = TREE_TYPE (templ);
6225 tree found = NULL_TREE;
6228 int is_partial_instantiation;
6230 gen_tmpl = most_general_template (templ);
6231 parmlist = DECL_TEMPLATE_PARMS (gen_tmpl);
6232 parm_depth = TMPL_PARMS_DEPTH (parmlist);
6233 arg_depth = TMPL_ARGS_DEPTH (arglist);
6235 if (arg_depth == 1 && parm_depth > 1)
6237 /* We've been given an incomplete set of template arguments.
6240 template <class T> struct S1 {
6241 template <class U> struct S2 {};
6242 template <class U> struct S2<U*> {};
6245 we will be called with an ARGLIST of `U*', but the
6246 TEMPLATE will be `template <class T> template
6247 <class U> struct S1<T>::S2'. We must fill in the missing
6250 = add_outermost_template_args (TYPE_TI_ARGS (TREE_TYPE (templ)),
6252 arg_depth = TMPL_ARGS_DEPTH (arglist);
6255 /* Now we should have enough arguments. */
6256 gcc_assert (parm_depth == arg_depth);
6258 /* From here on, we're only interested in the most general
6261 /* Calculate the BOUND_ARGS. These will be the args that are
6262 actually tsubst'd into the definition to create the
6266 /* We have multiple levels of arguments to coerce, at once. */
6268 int saved_depth = TMPL_ARGS_DEPTH (arglist);
6270 tree bound_args = make_tree_vec (parm_depth);
6272 for (i = saved_depth,
6273 t = DECL_TEMPLATE_PARMS (gen_tmpl);
6274 i > 0 && t != NULL_TREE;
6275 --i, t = TREE_CHAIN (t))
6277 tree a = coerce_template_parms (TREE_VALUE (t),
6280 /*require_all_args=*/true,
6281 /*use_default_args=*/true);
6283 /* Don't process further if one of the levels fails. */
6284 if (a == error_mark_node)
6286 /* Restore the ARGLIST to its full size. */
6287 TREE_VEC_LENGTH (arglist) = saved_depth;
6288 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6291 SET_TMPL_ARGS_LEVEL (bound_args, i, a);
6293 /* We temporarily reduce the length of the ARGLIST so
6294 that coerce_template_parms will see only the arguments
6295 corresponding to the template parameters it is
6297 TREE_VEC_LENGTH (arglist)--;
6300 /* Restore the ARGLIST to its full size. */
6301 TREE_VEC_LENGTH (arglist) = saved_depth;
6303 arglist = bound_args;
6307 = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parmlist),
6308 INNERMOST_TEMPLATE_ARGS (arglist),
6311 /*require_all_args=*/true,
6312 /*use_default_args=*/true);
6314 if (arglist == error_mark_node)
6315 /* We were unable to bind the arguments. */
6316 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6318 /* In the scope of a template class, explicit references to the
6319 template class refer to the type of the template, not any
6320 instantiation of it. For example, in:
6322 template <class T> class C { void f(C<T>); }
6324 the `C<T>' is just the same as `C'. Outside of the
6325 class, however, such a reference is an instantiation. */
6327 || !PRIMARY_TEMPLATE_P (gen_tmpl)
6328 || currently_open_class (template_type))
6329 /* comp_template_args is expensive, check it last. */
6330 && comp_template_args (TYPE_TI_ARGS (template_type),
6332 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, template_type);
6334 /* If we already have this specialization, return it. */
6335 elt.tmpl = gen_tmpl;
6337 hash = hash_specialization (&elt);
6338 entry = (spec_entry *) htab_find_with_hash (type_specializations,
6342 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, entry->spec);
6344 /* This type is a "partial instantiation" if any of the template
6345 arguments still involve template parameters. Note that we set
6346 IS_PARTIAL_INSTANTIATION for partial specializations as
6348 is_partial_instantiation = uses_template_parms (arglist);
6350 /* If the deduced arguments are invalid, then the binding
6352 if (!is_partial_instantiation
6353 && check_instantiated_args (gen_tmpl,
6354 INNERMOST_TEMPLATE_ARGS (arglist),
6356 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6358 if (!is_partial_instantiation
6359 && !PRIMARY_TEMPLATE_P (gen_tmpl)
6360 && !LAMBDA_TYPE_P (TREE_TYPE (gen_tmpl))
6361 && TREE_CODE (CP_DECL_CONTEXT (gen_tmpl)) == NAMESPACE_DECL)
6363 found = xref_tag_from_type (TREE_TYPE (gen_tmpl),
6364 DECL_NAME (gen_tmpl),
6365 /*tag_scope=*/ts_global);
6366 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, found);
6369 context = tsubst (DECL_CONTEXT (gen_tmpl), arglist,
6372 context = global_namespace;
6374 /* Create the type. */
6375 if (TREE_CODE (template_type) == ENUMERAL_TYPE)
6377 if (!is_partial_instantiation)
6379 set_current_access_from_decl (TYPE_NAME (template_type));
6380 t = start_enum (TYPE_IDENTIFIER (template_type),
6381 tsubst (ENUM_UNDERLYING_TYPE (template_type),
6382 arglist, complain, in_decl),
6383 SCOPED_ENUM_P (template_type));
6387 /* We don't want to call start_enum for this type, since
6388 the values for the enumeration constants may involve
6389 template parameters. And, no one should be interested
6390 in the enumeration constants for such a type. */
6391 t = cxx_make_type (ENUMERAL_TYPE);
6392 SET_SCOPED_ENUM_P (t, SCOPED_ENUM_P (template_type));
6397 t = make_class_type (TREE_CODE (template_type));
6398 CLASSTYPE_DECLARED_CLASS (t)
6399 = CLASSTYPE_DECLARED_CLASS (template_type);
6400 SET_CLASSTYPE_IMPLICIT_INSTANTIATION (t);
6401 TYPE_FOR_JAVA (t) = TYPE_FOR_JAVA (template_type);
6403 /* A local class. Make sure the decl gets registered properly. */
6404 if (context == current_function_decl)
6405 pushtag (DECL_NAME (gen_tmpl), t, /*tag_scope=*/ts_current);
6407 if (comp_template_args (CLASSTYPE_TI_ARGS (template_type), arglist))
6408 /* This instantiation is another name for the primary
6409 template type. Set the TYPE_CANONICAL field
6411 TYPE_CANONICAL (t) = template_type;
6412 else if (any_template_arguments_need_structural_equality_p (arglist))
6413 /* Some of the template arguments require structural
6414 equality testing, so this template class requires
6415 structural equality testing. */
6416 SET_TYPE_STRUCTURAL_EQUALITY (t);
6419 /* If we called start_enum or pushtag above, this information
6420 will already be set up. */
6423 TYPE_CONTEXT (t) = FROB_CONTEXT (context);
6425 type_decl = create_implicit_typedef (DECL_NAME (gen_tmpl), t);
6426 DECL_CONTEXT (type_decl) = TYPE_CONTEXT (t);
6427 DECL_SOURCE_LOCATION (type_decl)
6428 = DECL_SOURCE_LOCATION (TYPE_STUB_DECL (template_type));
6431 type_decl = TYPE_NAME (t);
6433 TREE_PRIVATE (type_decl)
6434 = TREE_PRIVATE (TYPE_STUB_DECL (template_type));
6435 TREE_PROTECTED (type_decl)
6436 = TREE_PROTECTED (TYPE_STUB_DECL (template_type));
6437 if (CLASSTYPE_VISIBILITY_SPECIFIED (template_type))
6439 DECL_VISIBILITY_SPECIFIED (type_decl) = 1;
6440 DECL_VISIBILITY (type_decl) = CLASSTYPE_VISIBILITY (template_type);
6443 /* Set up the template information. We have to figure out which
6444 template is the immediate parent if this is a full
6446 if (parm_depth == 1 || is_partial_instantiation
6447 || !PRIMARY_TEMPLATE_P (gen_tmpl))
6448 /* This case is easy; there are no member templates involved. */
6452 /* This is a full instantiation of a member template. Find
6453 the partial instantiation of which this is an instance. */
6455 /* Temporarily reduce by one the number of levels in the ARGLIST
6456 so as to avoid comparing the last set of arguments. */
6457 TREE_VEC_LENGTH (arglist)--;
6458 found = tsubst (gen_tmpl, arglist, complain, NULL_TREE);
6459 TREE_VEC_LENGTH (arglist)++;
6460 found = CLASSTYPE_TI_TEMPLATE (found);
6463 SET_TYPE_TEMPLATE_INFO (t, build_template_info (found, arglist));
6466 slot = (spec_entry **) htab_find_slot_with_hash (type_specializations,
6467 &elt, hash, INSERT);
6468 *slot = GGC_NEW (spec_entry);
6471 /* Note this use of the partial instantiation so we can check it
6472 later in maybe_process_partial_specialization. */
6473 DECL_TEMPLATE_INSTANTIATIONS (templ)
6474 = tree_cons (arglist, t,
6475 DECL_TEMPLATE_INSTANTIATIONS (templ));
6477 if (TREE_CODE (t) == ENUMERAL_TYPE
6478 && !is_partial_instantiation)
6479 /* Now that the type has been registered on the instantiations
6480 list, we set up the enumerators. Because the enumeration
6481 constants may involve the enumeration type itself, we make
6482 sure to register the type first, and then create the
6483 constants. That way, doing tsubst_expr for the enumeration
6484 constants won't result in recursive calls here; we'll find
6485 the instantiation and exit above. */
6486 tsubst_enum (template_type, t, arglist);
6488 if (is_partial_instantiation)
6489 /* If the type makes use of template parameters, the
6490 code that generates debugging information will crash. */
6491 DECL_IGNORED_P (TYPE_STUB_DECL (t)) = 1;
6493 /* Possibly limit visibility based on template args. */
6494 TREE_PUBLIC (type_decl) = 1;
6495 determine_visibility (type_decl);
6497 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, t);
6499 timevar_pop (TV_NAME_LOOKUP);
6506 /* True when we should also visit template parameters that occur in
6507 non-deduced contexts. */
6508 bool include_nondeduced_p;
6509 struct pointer_set_t *visited;
6512 /* Called from for_each_template_parm via walk_tree. */
6515 for_each_template_parm_r (tree *tp, int *walk_subtrees, void *d)
6518 struct pair_fn_data *pfd = (struct pair_fn_data *) d;
6519 tree_fn_t fn = pfd->fn;
6520 void *data = pfd->data;
6523 && (pfd->include_nondeduced_p || TREE_CODE (t) != TYPENAME_TYPE)
6524 && for_each_template_parm (TYPE_CONTEXT (t), fn, data, pfd->visited,
6525 pfd->include_nondeduced_p))
6526 return error_mark_node;
6528 switch (TREE_CODE (t))
6531 if (TYPE_PTRMEMFUNC_P (t))
6537 if (!TYPE_TEMPLATE_INFO (t))
6539 else if (for_each_template_parm (TI_ARGS (TYPE_TEMPLATE_INFO (t)),
6540 fn, data, pfd->visited,
6541 pfd->include_nondeduced_p))
6542 return error_mark_node;
6546 if (for_each_template_parm (TYPE_MIN_VALUE (t),
6547 fn, data, pfd->visited,
6548 pfd->include_nondeduced_p)
6549 || for_each_template_parm (TYPE_MAX_VALUE (t),
6550 fn, data, pfd->visited,
6551 pfd->include_nondeduced_p))
6552 return error_mark_node;
6556 /* Since we're not going to walk subtrees, we have to do this
6558 if (for_each_template_parm (TYPE_METHOD_BASETYPE (t), fn, data,
6559 pfd->visited, pfd->include_nondeduced_p))
6560 return error_mark_node;
6564 /* Check the return type. */
6565 if (for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
6566 pfd->include_nondeduced_p))
6567 return error_mark_node;
6569 /* Check the parameter types. Since default arguments are not
6570 instantiated until they are needed, the TYPE_ARG_TYPES may
6571 contain expressions that involve template parameters. But,
6572 no-one should be looking at them yet. And, once they're
6573 instantiated, they don't contain template parameters, so
6574 there's no point in looking at them then, either. */
6578 for (parm = TYPE_ARG_TYPES (t); parm; parm = TREE_CHAIN (parm))
6579 if (for_each_template_parm (TREE_VALUE (parm), fn, data,
6580 pfd->visited, pfd->include_nondeduced_p))
6581 return error_mark_node;
6583 /* Since we've already handled the TYPE_ARG_TYPES, we don't
6584 want walk_tree walking into them itself. */
6590 if (pfd->include_nondeduced_p
6591 && for_each_template_parm (TYPE_FIELDS (t), fn, data,
6593 pfd->include_nondeduced_p))
6594 return error_mark_node;
6599 if (DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t)
6600 && for_each_template_parm (DECL_TI_ARGS (t), fn, data,
6601 pfd->visited, pfd->include_nondeduced_p))
6602 return error_mark_node;
6607 if (TREE_CODE (t) == CONST_DECL && DECL_TEMPLATE_PARM_P (t)
6608 && for_each_template_parm (DECL_INITIAL (t), fn, data,
6609 pfd->visited, pfd->include_nondeduced_p))
6610 return error_mark_node;
6611 if (DECL_CONTEXT (t)
6612 && pfd->include_nondeduced_p
6613 && for_each_template_parm (DECL_CONTEXT (t), fn, data,
6614 pfd->visited, pfd->include_nondeduced_p))
6615 return error_mark_node;
6618 case BOUND_TEMPLATE_TEMPLATE_PARM:
6619 /* Record template parameters such as `T' inside `TT<T>'. */
6620 if (for_each_template_parm (TYPE_TI_ARGS (t), fn, data, pfd->visited,
6621 pfd->include_nondeduced_p))
6622 return error_mark_node;
6625 case TEMPLATE_TEMPLATE_PARM:
6626 case TEMPLATE_TYPE_PARM:
6627 case TEMPLATE_PARM_INDEX:
6628 if (fn && (*fn)(t, data))
6629 return error_mark_node;
6631 return error_mark_node;
6635 /* A template template parameter is encountered. */
6636 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t)
6637 && for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
6638 pfd->include_nondeduced_p))
6639 return error_mark_node;
6641 /* Already substituted template template parameter */
6647 || for_each_template_parm (TYPENAME_TYPE_FULLNAME (t), fn,
6649 pfd->include_nondeduced_p))
6650 return error_mark_node;
6654 if (TREE_TYPE (t) && TYPE_PTRMEMFUNC_P (TREE_TYPE (t))
6655 && pfd->include_nondeduced_p
6656 && for_each_template_parm (TYPE_PTRMEMFUNC_FN_TYPE
6657 (TREE_TYPE (t)), fn, data,
6658 pfd->visited, pfd->include_nondeduced_p))
6659 return error_mark_node;
6664 /* If there's no type, then this thing must be some expression
6665 involving template parameters. */
6666 if (!fn && !TREE_TYPE (t))
6667 return error_mark_node;
6672 case REINTERPRET_CAST_EXPR:
6673 case CONST_CAST_EXPR:
6674 case STATIC_CAST_EXPR:
6675 case DYNAMIC_CAST_EXPR:
6679 case PSEUDO_DTOR_EXPR:
6681 return error_mark_node;
6688 /* We didn't find any template parameters we liked. */
6692 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
6693 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
6694 call FN with the parameter and the DATA.
6695 If FN returns nonzero, the iteration is terminated, and
6696 for_each_template_parm returns 1. Otherwise, the iteration
6697 continues. If FN never returns a nonzero value, the value
6698 returned by for_each_template_parm is 0. If FN is NULL, it is
6699 considered to be the function which always returns 1.
6701 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
6702 parameters that occur in non-deduced contexts. When false, only
6703 visits those template parameters that can be deduced. */
6706 for_each_template_parm (tree t, tree_fn_t fn, void* data,
6707 struct pointer_set_t *visited,
6708 bool include_nondeduced_p)
6710 struct pair_fn_data pfd;
6716 pfd.include_nondeduced_p = include_nondeduced_p;
6718 /* Walk the tree. (Conceptually, we would like to walk without
6719 duplicates, but for_each_template_parm_r recursively calls
6720 for_each_template_parm, so we would need to reorganize a fair
6721 bit to use walk_tree_without_duplicates, so we keep our own
6724 pfd.visited = visited;
6726 pfd.visited = pointer_set_create ();
6727 result = cp_walk_tree (&t,
6728 for_each_template_parm_r,
6730 pfd.visited) != NULL_TREE;
6735 pointer_set_destroy (pfd.visited);
6742 /* Returns true if T depends on any template parameter. */
6745 uses_template_parms (tree t)
6748 int saved_processing_template_decl;
6750 saved_processing_template_decl = processing_template_decl;
6751 if (!saved_processing_template_decl)
6752 processing_template_decl = 1;
6754 dependent_p = dependent_type_p (t);
6755 else if (TREE_CODE (t) == TREE_VEC)
6756 dependent_p = any_dependent_template_arguments_p (t);
6757 else if (TREE_CODE (t) == TREE_LIST)
6758 dependent_p = (uses_template_parms (TREE_VALUE (t))
6759 || uses_template_parms (TREE_CHAIN (t)));
6760 else if (TREE_CODE (t) == TYPE_DECL)
6761 dependent_p = dependent_type_p (TREE_TYPE (t));
6764 || TREE_CODE (t) == TEMPLATE_PARM_INDEX
6765 || TREE_CODE (t) == OVERLOAD
6766 || TREE_CODE (t) == BASELINK
6767 || TREE_CODE (t) == IDENTIFIER_NODE
6768 || TREE_CODE (t) == TRAIT_EXPR
6769 || TREE_CODE (t) == CONSTRUCTOR
6770 || CONSTANT_CLASS_P (t))
6771 dependent_p = (type_dependent_expression_p (t)
6772 || value_dependent_expression_p (t));
6775 gcc_assert (t == error_mark_node);
6776 dependent_p = false;
6779 processing_template_decl = saved_processing_template_decl;
6784 /* Returns true if T depends on any template parameter with level LEVEL. */
6787 uses_template_parms_level (tree t, int level)
6789 return for_each_template_parm (t, template_parm_this_level_p, &level, NULL,
6790 /*include_nondeduced_p=*/true);
6793 static int tinst_depth;
6794 extern int max_tinst_depth;
6795 #ifdef GATHER_STATISTICS
6798 static int tinst_level_tick;
6799 static int last_template_error_tick;
6801 /* We're starting to instantiate D; record the template instantiation context
6802 for diagnostics and to restore it later. */
6805 push_tinst_level (tree d)
6807 struct tinst_level *new_level;
6809 if (tinst_depth >= max_tinst_depth)
6811 /* If the instantiation in question still has unbound template parms,
6812 we don't really care if we can't instantiate it, so just return.
6813 This happens with base instantiation for implicit `typename'. */
6814 if (uses_template_parms (d))
6817 last_template_error_tick = tinst_level_tick;
6818 error ("template instantiation depth exceeds maximum of %d (use "
6819 "-ftemplate-depth-NN to increase the maximum) instantiating %qD",
6820 max_tinst_depth, d);
6822 print_instantiation_context ();
6827 new_level = GGC_NEW (struct tinst_level);
6828 new_level->decl = d;
6829 new_level->locus = input_location;
6830 new_level->in_system_header_p = in_system_header;
6831 new_level->next = current_tinst_level;
6832 current_tinst_level = new_level;
6835 #ifdef GATHER_STATISTICS
6836 if (tinst_depth > depth_reached)
6837 depth_reached = tinst_depth;
6844 /* We're done instantiating this template; return to the instantiation
6848 pop_tinst_level (void)
6850 /* Restore the filename and line number stashed away when we started
6851 this instantiation. */
6852 input_location = current_tinst_level->locus;
6853 current_tinst_level = current_tinst_level->next;
6858 /* We're instantiating a deferred template; restore the template
6859 instantiation context in which the instantiation was requested, which
6860 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
6863 reopen_tinst_level (struct tinst_level *level)
6865 struct tinst_level *t;
6868 for (t = level; t; t = t->next)
6871 current_tinst_level = level;
6876 /* Returns the TINST_LEVEL which gives the original instantiation
6879 struct tinst_level *
6880 outermost_tinst_level (void)
6882 struct tinst_level *level = current_tinst_level;
6885 level = level->next;
6889 /* Returns TRUE if PARM is a parameter of the template TEMPL. */
6892 parameter_of_template_p (tree parm, tree templ)
6897 if (!parm || !templ)
6900 gcc_assert (DECL_TEMPLATE_PARM_P (parm));
6901 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
6903 parms = DECL_TEMPLATE_PARMS (templ);
6904 parms = INNERMOST_TEMPLATE_PARMS (parms);
6906 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
6907 if (parm == TREE_VALUE (TREE_VEC_ELT (parms, i)))
6913 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
6914 vector of template arguments, as for tsubst.
6916 Returns an appropriate tsubst'd friend declaration. */
6919 tsubst_friend_function (tree decl, tree args)
6923 if (TREE_CODE (decl) == FUNCTION_DECL
6924 && DECL_TEMPLATE_INSTANTIATION (decl)
6925 && TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
6926 /* This was a friend declared with an explicit template
6927 argument list, e.g.:
6931 to indicate that f was a template instantiation, not a new
6932 function declaration. Now, we have to figure out what
6933 instantiation of what template. */
6935 tree template_id, arglist, fns;
6938 tree ns = decl_namespace_context (TYPE_MAIN_DECL (current_class_type));
6940 /* Friend functions are looked up in the containing namespace scope.
6941 We must enter that scope, to avoid finding member functions of the
6942 current class with same name. */
6943 push_nested_namespace (ns);
6944 fns = tsubst_expr (DECL_TI_TEMPLATE (decl), args,
6945 tf_warning_or_error, NULL_TREE,
6946 /*integral_constant_expression_p=*/false);
6947 pop_nested_namespace (ns);
6948 arglist = tsubst (DECL_TI_ARGS (decl), args,
6949 tf_warning_or_error, NULL_TREE);
6950 template_id = lookup_template_function (fns, arglist);
6952 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
6953 tmpl = determine_specialization (template_id, new_friend,
6955 /*need_member_template=*/0,
6956 TREE_VEC_LENGTH (args),
6958 return instantiate_template (tmpl, new_args, tf_error);
6961 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
6963 /* The NEW_FRIEND will look like an instantiation, to the
6964 compiler, but is not an instantiation from the point of view of
6965 the language. For example, we might have had:
6967 template <class T> struct S {
6968 template <class U> friend void f(T, U);
6971 Then, in S<int>, template <class U> void f(int, U) is not an
6972 instantiation of anything. */
6973 if (new_friend == error_mark_node)
6974 return error_mark_node;
6976 DECL_USE_TEMPLATE (new_friend) = 0;
6977 if (TREE_CODE (decl) == TEMPLATE_DECL)
6979 DECL_USE_TEMPLATE (DECL_TEMPLATE_RESULT (new_friend)) = 0;
6980 DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (new_friend))
6981 = DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (decl));
6984 /* The mangled name for the NEW_FRIEND is incorrect. The function
6985 is not a template instantiation and should not be mangled like
6986 one. Therefore, we forget the mangling here; we'll recompute it
6987 later if we need it. */
6988 if (TREE_CODE (new_friend) != TEMPLATE_DECL)
6990 SET_DECL_RTL (new_friend, NULL_RTX);
6991 SET_DECL_ASSEMBLER_NAME (new_friend, NULL_TREE);
6994 if (DECL_NAMESPACE_SCOPE_P (new_friend))
6997 tree new_friend_template_info;
6998 tree new_friend_result_template_info;
7000 int new_friend_is_defn;
7002 /* We must save some information from NEW_FRIEND before calling
7003 duplicate decls since that function will free NEW_FRIEND if
7005 new_friend_template_info = DECL_TEMPLATE_INFO (new_friend);
7006 new_friend_is_defn =
7007 (DECL_INITIAL (DECL_TEMPLATE_RESULT
7008 (template_for_substitution (new_friend)))
7010 if (TREE_CODE (new_friend) == TEMPLATE_DECL)
7012 /* This declaration is a `primary' template. */
7013 DECL_PRIMARY_TEMPLATE (new_friend) = new_friend;
7015 new_friend_result_template_info
7016 = DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (new_friend));
7019 new_friend_result_template_info = NULL_TREE;
7021 /* Make the init_value nonzero so pushdecl knows this is a defn. */
7022 if (new_friend_is_defn)
7023 DECL_INITIAL (new_friend) = error_mark_node;
7025 /* Inside pushdecl_namespace_level, we will push into the
7026 current namespace. However, the friend function should go
7027 into the namespace of the template. */
7028 ns = decl_namespace_context (new_friend);
7029 push_nested_namespace (ns);
7030 old_decl = pushdecl_namespace_level (new_friend, /*is_friend=*/true);
7031 pop_nested_namespace (ns);
7033 if (old_decl == error_mark_node)
7034 return error_mark_node;
7036 if (old_decl != new_friend)
7038 /* This new friend declaration matched an existing
7039 declaration. For example, given:
7041 template <class T> void f(T);
7042 template <class U> class C {
7043 template <class T> friend void f(T) {}
7046 the friend declaration actually provides the definition
7047 of `f', once C has been instantiated for some type. So,
7048 old_decl will be the out-of-class template declaration,
7049 while new_friend is the in-class definition.
7051 But, if `f' was called before this point, the
7052 instantiation of `f' will have DECL_TI_ARGS corresponding
7053 to `T' but not to `U', references to which might appear
7054 in the definition of `f'. Previously, the most general
7055 template for an instantiation of `f' was the out-of-class
7056 version; now it is the in-class version. Therefore, we
7057 run through all specialization of `f', adding to their
7058 DECL_TI_ARGS appropriately. In particular, they need a
7059 new set of outer arguments, corresponding to the
7060 arguments for this class instantiation.
7062 The same situation can arise with something like this:
7065 template <class T> class C {
7069 when `C<int>' is instantiated. Now, `f(int)' is defined
7072 if (!new_friend_is_defn)
7073 /* On the other hand, if the in-class declaration does
7074 *not* provide a definition, then we don't want to alter
7075 existing definitions. We can just leave everything
7080 tree new_template = TI_TEMPLATE (new_friend_template_info);
7081 tree new_args = TI_ARGS (new_friend_template_info);
7083 /* Overwrite whatever template info was there before, if
7084 any, with the new template information pertaining to
7086 DECL_TEMPLATE_INFO (old_decl) = new_friend_template_info;
7088 if (TREE_CODE (old_decl) != TEMPLATE_DECL)
7089 /* We should have called reregister_specialization in
7091 gcc_assert (retrieve_specialization (new_template,
7098 /* Indicate that the old function template is a partial
7100 DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (old_decl))
7101 = new_friend_result_template_info;
7103 gcc_assert (new_template
7104 == most_general_template (new_template));
7105 gcc_assert (new_template != old_decl);
7107 /* Reassign any specializations already in the hash table
7108 to the new more general template, and add the
7109 additional template args. */
7110 for (t = DECL_TEMPLATE_INSTANTIATIONS (old_decl);
7114 tree spec = TREE_VALUE (t);
7117 elt.tmpl = old_decl;
7118 elt.args = DECL_TI_ARGS (spec);
7119 elt.spec = NULL_TREE;
7121 htab_remove_elt (decl_specializations, &elt);
7124 = add_outermost_template_args (new_args,
7125 DECL_TI_ARGS (spec));
7127 register_specialization
7128 (spec, new_template, DECL_TI_ARGS (spec), true, 0);
7131 DECL_TEMPLATE_INSTANTIATIONS (old_decl) = NULL_TREE;
7135 /* The information from NEW_FRIEND has been merged into OLD_DECL
7136 by duplicate_decls. */
7137 new_friend = old_decl;
7142 tree context = DECL_CONTEXT (new_friend);
7146 template <class T> class C {
7147 template <class U> friend void C1<U>::f (); // case 1
7148 friend void C2<T>::f (); // case 2
7150 we only need to make sure CONTEXT is a complete type for
7151 case 2. To distinguish between the two cases, we note that
7152 CONTEXT of case 1 remains dependent type after tsubst while
7153 this isn't true for case 2. */
7154 ++processing_template_decl;
7155 dependent_p = dependent_type_p (context);
7156 --processing_template_decl;
7159 && !complete_type_or_else (context, NULL_TREE))
7160 return error_mark_node;
7162 if (COMPLETE_TYPE_P (context))
7164 /* Check to see that the declaration is really present, and,
7165 possibly obtain an improved declaration. */
7166 tree fn = check_classfn (context,
7167 new_friend, NULL_TREE);
7177 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
7178 template arguments, as for tsubst.
7180 Returns an appropriate tsubst'd friend type or error_mark_node on
7184 tsubst_friend_class (tree friend_tmpl, tree args)
7190 context = DECL_CONTEXT (friend_tmpl);
7194 if (TREE_CODE (context) == NAMESPACE_DECL)
7195 push_nested_namespace (context);
7197 push_nested_class (tsubst (context, args, tf_none, NULL_TREE));
7200 /* Look for a class template declaration. We look for hidden names
7201 because two friend declarations of the same template are the
7202 same. For example, in:
7205 template <typename> friend class F;
7207 template <typename> struct B {
7208 template <typename> friend class F;
7211 both F templates are the same. */
7212 tmpl = lookup_name_real (DECL_NAME (friend_tmpl), 0, 0,
7213 /*block_p=*/true, 0,
7214 LOOKUP_COMPLAIN | LOOKUP_HIDDEN);
7216 /* But, if we don't find one, it might be because we're in a
7217 situation like this:
7225 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
7226 for `S<int>', not the TEMPLATE_DECL. */
7227 if (!tmpl || !DECL_CLASS_TEMPLATE_P (tmpl))
7229 tmpl = lookup_name_prefer_type (DECL_NAME (friend_tmpl), 1);
7230 tmpl = maybe_get_template_decl_from_type_decl (tmpl);
7233 if (tmpl && DECL_CLASS_TEMPLATE_P (tmpl))
7235 /* The friend template has already been declared. Just
7236 check to see that the declarations match, and install any new
7237 default parameters. We must tsubst the default parameters,
7238 of course. We only need the innermost template parameters
7239 because that is all that redeclare_class_template will look
7241 if (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (friend_tmpl))
7242 > TMPL_ARGS_DEPTH (args))
7245 location_t saved_input_location;
7246 parms = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_tmpl),
7247 args, tf_warning_or_error);
7249 saved_input_location = input_location;
7250 input_location = DECL_SOURCE_LOCATION (friend_tmpl);
7251 redeclare_class_template (TREE_TYPE (tmpl), parms);
7252 input_location = saved_input_location;
7256 friend_type = TREE_TYPE (tmpl);
7260 /* The friend template has not already been declared. In this
7261 case, the instantiation of the template class will cause the
7262 injection of this template into the global scope. */
7263 tmpl = tsubst (friend_tmpl, args, tf_warning_or_error, NULL_TREE);
7264 if (tmpl == error_mark_node)
7265 return error_mark_node;
7267 /* The new TMPL is not an instantiation of anything, so we
7268 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
7269 the new type because that is supposed to be the corresponding
7270 template decl, i.e., TMPL. */
7271 DECL_USE_TEMPLATE (tmpl) = 0;
7272 DECL_TEMPLATE_INFO (tmpl) = NULL_TREE;
7273 CLASSTYPE_USE_TEMPLATE (TREE_TYPE (tmpl)) = 0;
7274 CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl))
7275 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl)));
7277 /* Inject this template into the global scope. */
7278 friend_type = TREE_TYPE (pushdecl_top_level_maybe_friend (tmpl, true));
7283 if (TREE_CODE (context) == NAMESPACE_DECL)
7284 pop_nested_namespace (context);
7286 pop_nested_class ();
7292 /* Returns zero if TYPE cannot be completed later due to circularity.
7293 Otherwise returns one. */
7296 can_complete_type_without_circularity (tree type)
7298 if (type == NULL_TREE || type == error_mark_node)
7300 else if (COMPLETE_TYPE_P (type))
7302 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
7303 return can_complete_type_without_circularity (TREE_TYPE (type));
7304 else if (CLASS_TYPE_P (type)
7305 && TYPE_BEING_DEFINED (TYPE_MAIN_VARIANT (type)))
7311 /* Apply any attributes which had to be deferred until instantiation
7312 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
7313 ARGS, COMPLAIN, IN_DECL are as tsubst. */
7316 apply_late_template_attributes (tree *decl_p, tree attributes, int attr_flags,
7317 tree args, tsubst_flags_t complain, tree in_decl)
7319 tree last_dep = NULL_TREE;
7323 for (t = attributes; t; t = TREE_CHAIN (t))
7324 if (ATTR_IS_DEPENDENT (t))
7327 attributes = copy_list (attributes);
7331 if (DECL_P (*decl_p))
7333 if (TREE_TYPE (*decl_p) == error_mark_node)
7335 p = &DECL_ATTRIBUTES (*decl_p);
7338 p = &TYPE_ATTRIBUTES (*decl_p);
7342 tree late_attrs = NULL_TREE;
7343 tree *q = &late_attrs;
7345 for (*p = attributes; *p; )
7348 if (ATTR_IS_DEPENDENT (t))
7350 *p = TREE_CHAIN (t);
7351 TREE_CHAIN (t) = NULL_TREE;
7352 /* If the first attribute argument is an identifier, don't
7353 pass it through tsubst. Attributes like mode, format,
7354 cleanup and several target specific attributes expect it
7357 && TREE_CODE (TREE_VALUE (t)) == TREE_LIST
7358 && TREE_VALUE (TREE_VALUE (t))
7359 && (TREE_CODE (TREE_VALUE (TREE_VALUE (t)))
7360 == IDENTIFIER_NODE))
7363 = tsubst_expr (TREE_CHAIN (TREE_VALUE (t)), args, complain,
7365 /*integral_constant_expression_p=*/false);
7366 if (chain != TREE_CHAIN (TREE_VALUE (t)))
7368 = tree_cons (NULL_TREE, TREE_VALUE (TREE_VALUE (t)),
7373 = tsubst_expr (TREE_VALUE (t), args, complain, in_decl,
7374 /*integral_constant_expression_p=*/false);
7376 q = &TREE_CHAIN (t);
7379 p = &TREE_CHAIN (t);
7382 cplus_decl_attributes (decl_p, late_attrs, attr_flags);
7386 /* Perform (or defer) access check for typedefs that were referenced
7387 from within the template TMPL code.
7388 This is a subroutine of instantiate_template and instantiate_class_template.
7389 TMPL is the template to consider and TARGS is the list of arguments of
7393 perform_typedefs_access_check (tree tmpl, tree targs)
7395 location_t saved_location;
7397 qualified_typedef_usage_t *iter;
7400 || (!CLASS_TYPE_P (tmpl)
7401 && TREE_CODE (tmpl) != FUNCTION_DECL))
7404 saved_location = input_location;
7406 VEC_iterate (qualified_typedef_usage_t,
7407 get_types_needing_access_check (tmpl),
7411 tree type_decl = iter->typedef_decl;
7412 tree type_scope = iter->context;
7414 if (!type_decl || !type_scope || !CLASS_TYPE_P (type_scope))
7417 if (uses_template_parms (type_decl))
7418 type_decl = tsubst (type_decl, targs, tf_error, NULL_TREE);
7419 if (uses_template_parms (type_scope))
7420 type_scope = tsubst (type_scope, targs, tf_error, NULL_TREE);
7422 /* Make access check error messages point to the location
7423 of the use of the typedef. */
7424 input_location = iter->locus;
7425 perform_or_defer_access_check (TYPE_BINFO (type_scope),
7426 type_decl, type_decl);
7428 input_location = saved_location;
7432 instantiate_class_template (tree type)
7434 tree templ, args, pattern, t, member;
7438 unsigned int saved_maximum_field_alignment;
7440 if (type == error_mark_node)
7441 return error_mark_node;
7443 if (TYPE_BEING_DEFINED (type)
7444 || COMPLETE_TYPE_P (type)
7445 || uses_template_parms (type))
7448 /* Figure out which template is being instantiated. */
7449 templ = most_general_template (CLASSTYPE_TI_TEMPLATE (type));
7450 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
7452 /* Determine what specialization of the original template to
7454 t = most_specialized_class (type, templ);
7455 if (t == error_mark_node)
7457 TYPE_BEING_DEFINED (type) = 1;
7458 return error_mark_node;
7462 /* This TYPE is actually an instantiation of a partial
7463 specialization. We replace the innermost set of ARGS with
7464 the arguments appropriate for substitution. For example,
7467 template <class T> struct S {};
7468 template <class T> struct S<T*> {};
7470 and supposing that we are instantiating S<int*>, ARGS will
7471 presently be {int*} -- but we need {int}. */
7472 pattern = TREE_TYPE (t);
7473 args = TREE_PURPOSE (t);
7477 pattern = TREE_TYPE (templ);
7478 args = CLASSTYPE_TI_ARGS (type);
7481 /* If the template we're instantiating is incomplete, then clearly
7482 there's nothing we can do. */
7483 if (!COMPLETE_TYPE_P (pattern))
7486 /* If we've recursively instantiated too many templates, stop. */
7487 if (! push_tinst_level (type))
7490 /* Now we're really doing the instantiation. Mark the type as in
7491 the process of being defined. */
7492 TYPE_BEING_DEFINED (type) = 1;
7494 /* We may be in the middle of deferred access check. Disable
7496 push_deferring_access_checks (dk_no_deferred);
7498 push_to_top_level ();
7499 /* Use #pragma pack from the template context. */
7500 saved_maximum_field_alignment = maximum_field_alignment;
7501 maximum_field_alignment = TYPE_PRECISION (pattern);
7503 SET_CLASSTYPE_INTERFACE_UNKNOWN (type);
7505 /* Set the input location to the most specialized template definition.
7506 This is needed if tsubsting causes an error. */
7507 typedecl = TYPE_MAIN_DECL (pattern);
7508 input_location = DECL_SOURCE_LOCATION (typedecl);
7510 TYPE_HAS_USER_CONSTRUCTOR (type) = TYPE_HAS_USER_CONSTRUCTOR (pattern);
7511 TYPE_HAS_NEW_OPERATOR (type) = TYPE_HAS_NEW_OPERATOR (pattern);
7512 TYPE_HAS_ARRAY_NEW_OPERATOR (type) = TYPE_HAS_ARRAY_NEW_OPERATOR (pattern);
7513 TYPE_GETS_DELETE (type) = TYPE_GETS_DELETE (pattern);
7514 TYPE_HAS_ASSIGN_REF (type) = TYPE_HAS_ASSIGN_REF (pattern);
7515 TYPE_HAS_CONST_ASSIGN_REF (type) = TYPE_HAS_CONST_ASSIGN_REF (pattern);
7516 TYPE_HAS_INIT_REF (type) = TYPE_HAS_INIT_REF (pattern);
7517 TYPE_HAS_CONST_INIT_REF (type) = TYPE_HAS_CONST_INIT_REF (pattern);
7518 TYPE_HAS_DEFAULT_CONSTRUCTOR (type) = TYPE_HAS_DEFAULT_CONSTRUCTOR (pattern);
7519 TYPE_HAS_CONVERSION (type) = TYPE_HAS_CONVERSION (pattern);
7520 TYPE_PACKED (type) = TYPE_PACKED (pattern);
7521 TYPE_ALIGN (type) = TYPE_ALIGN (pattern);
7522 TYPE_USER_ALIGN (type) = TYPE_USER_ALIGN (pattern);
7523 TYPE_FOR_JAVA (type) = TYPE_FOR_JAVA (pattern); /* For libjava's JArray<T> */
7524 if (ANON_AGGR_TYPE_P (pattern))
7525 SET_ANON_AGGR_TYPE_P (type);
7526 if (CLASSTYPE_VISIBILITY_SPECIFIED (pattern))
7528 CLASSTYPE_VISIBILITY_SPECIFIED (type) = 1;
7529 CLASSTYPE_VISIBILITY (type) = CLASSTYPE_VISIBILITY (pattern);
7532 pbinfo = TYPE_BINFO (pattern);
7534 /* We should never instantiate a nested class before its enclosing
7535 class; we need to look up the nested class by name before we can
7536 instantiate it, and that lookup should instantiate the enclosing
7538 gcc_assert (!DECL_CLASS_SCOPE_P (TYPE_MAIN_DECL (pattern))
7539 || COMPLETE_TYPE_P (TYPE_CONTEXT (type))
7540 || TYPE_BEING_DEFINED (TYPE_CONTEXT (type)));
7542 base_list = NULL_TREE;
7543 if (BINFO_N_BASE_BINFOS (pbinfo))
7546 tree context = TYPE_CONTEXT (type);
7550 /* We must enter the scope containing the type, as that is where
7551 the accessibility of types named in dependent bases are
7553 pushed_scope = push_scope (context ? context : global_namespace);
7555 /* Substitute into each of the bases to determine the actual
7557 for (i = 0; BINFO_BASE_ITERATE (pbinfo, i, pbase_binfo); i++)
7560 tree access = BINFO_BASE_ACCESS (pbinfo, i);
7561 tree expanded_bases = NULL_TREE;
7564 if (PACK_EXPANSION_P (BINFO_TYPE (pbase_binfo)))
7567 tsubst_pack_expansion (BINFO_TYPE (pbase_binfo),
7568 args, tf_error, NULL_TREE);
7569 if (expanded_bases == error_mark_node)
7572 len = TREE_VEC_LENGTH (expanded_bases);
7575 for (idx = 0; idx < len; idx++)
7578 /* Extract the already-expanded base class. */
7579 base = TREE_VEC_ELT (expanded_bases, idx);
7581 /* Substitute to figure out the base class. */
7582 base = tsubst (BINFO_TYPE (pbase_binfo), args, tf_error,
7585 if (base == error_mark_node)
7588 base_list = tree_cons (access, base, base_list);
7589 if (BINFO_VIRTUAL_P (pbase_binfo))
7590 TREE_TYPE (base_list) = integer_type_node;
7594 /* The list is now in reverse order; correct that. */
7595 base_list = nreverse (base_list);
7598 pop_scope (pushed_scope);
7600 /* Now call xref_basetypes to set up all the base-class
7602 xref_basetypes (type, base_list);
7604 apply_late_template_attributes (&type, TYPE_ATTRIBUTES (pattern),
7605 (int) ATTR_FLAG_TYPE_IN_PLACE,
7606 args, tf_error, NULL_TREE);
7608 /* Now that our base classes are set up, enter the scope of the
7609 class, so that name lookups into base classes, etc. will work
7610 correctly. This is precisely analogous to what we do in
7611 begin_class_definition when defining an ordinary non-template
7612 class, except we also need to push the enclosing classes. */
7613 push_nested_class (type);
7615 /* Now members are processed in the order of declaration. */
7616 for (member = CLASSTYPE_DECL_LIST (pattern);
7617 member; member = TREE_CHAIN (member))
7619 tree t = TREE_VALUE (member);
7621 if (TREE_PURPOSE (member))
7625 /* Build new CLASSTYPE_NESTED_UTDS. */
7628 bool class_template_p;
7630 class_template_p = (TREE_CODE (t) != ENUMERAL_TYPE
7631 && TYPE_LANG_SPECIFIC (t)
7632 && CLASSTYPE_IS_TEMPLATE (t));
7633 /* If the member is a class template, then -- even after
7634 substitution -- there may be dependent types in the
7635 template argument list for the class. We increment
7636 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
7637 that function will assume that no types are dependent
7638 when outside of a template. */
7639 if (class_template_p)
7640 ++processing_template_decl;
7641 newtag = tsubst (t, args, tf_error, NULL_TREE);
7642 if (class_template_p)
7643 --processing_template_decl;
7644 if (newtag == error_mark_node)
7647 if (TREE_CODE (newtag) != ENUMERAL_TYPE)
7649 tree name = TYPE_IDENTIFIER (t);
7651 if (class_template_p)
7652 /* Unfortunately, lookup_template_class sets
7653 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
7654 instantiation (i.e., for the type of a member
7655 template class nested within a template class.)
7656 This behavior is required for
7657 maybe_process_partial_specialization to work
7658 correctly, but is not accurate in this case;
7659 the TAG is not an instantiation of anything.
7660 (The corresponding TEMPLATE_DECL is an
7661 instantiation, but the TYPE is not.) */
7662 CLASSTYPE_USE_TEMPLATE (newtag) = 0;
7664 /* Now, we call pushtag to put this NEWTAG into the scope of
7665 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
7666 pushtag calling push_template_decl. We don't have to do
7667 this for enums because it will already have been done in
7670 SET_IDENTIFIER_TYPE_VALUE (name, newtag);
7671 pushtag (name, newtag, /*tag_scope=*/ts_current);
7674 else if (TREE_CODE (t) == FUNCTION_DECL
7675 || DECL_FUNCTION_TEMPLATE_P (t))
7677 /* Build new TYPE_METHODS. */
7680 if (TREE_CODE (t) == TEMPLATE_DECL)
7681 ++processing_template_decl;
7682 r = tsubst (t, args, tf_error, NULL_TREE);
7683 if (TREE_CODE (t) == TEMPLATE_DECL)
7684 --processing_template_decl;
7685 set_current_access_from_decl (r);
7686 finish_member_declaration (r);
7690 /* Build new TYPE_FIELDS. */
7691 if (TREE_CODE (t) == STATIC_ASSERT)
7694 tsubst_expr (STATIC_ASSERT_CONDITION (t), args,
7695 tf_warning_or_error, NULL_TREE,
7696 /*integral_constant_expression_p=*/true);
7697 finish_static_assert (condition,
7698 STATIC_ASSERT_MESSAGE (t),
7699 STATIC_ASSERT_SOURCE_LOCATION (t),
7702 else if (TREE_CODE (t) != CONST_DECL)
7706 /* The file and line for this declaration, to
7707 assist in error message reporting. Since we
7708 called push_tinst_level above, we don't need to
7710 input_location = DECL_SOURCE_LOCATION (t);
7712 if (TREE_CODE (t) == TEMPLATE_DECL)
7713 ++processing_template_decl;
7714 r = tsubst (t, args, tf_warning_or_error, NULL_TREE);
7715 if (TREE_CODE (t) == TEMPLATE_DECL)
7716 --processing_template_decl;
7717 if (TREE_CODE (r) == VAR_DECL)
7721 [t]he initialization (and any associated
7722 side-effects) of a static data member does
7723 not occur unless the static data member is
7724 itself used in a way that requires the
7725 definition of the static data member to
7728 Therefore, we do not substitute into the
7729 initialized for the static data member here. */
7730 finish_static_data_member_decl
7733 /*init_const_expr_p=*/false,
7734 /*asmspec_tree=*/NULL_TREE,
7736 if (DECL_INITIALIZED_IN_CLASS_P (r))
7737 check_static_variable_definition (r, TREE_TYPE (r));
7739 else if (TREE_CODE (r) == FIELD_DECL)
7741 /* Determine whether R has a valid type and can be
7742 completed later. If R is invalid, then it is
7743 replaced by error_mark_node so that it will not be
7744 added to TYPE_FIELDS. */
7745 tree rtype = TREE_TYPE (r);
7746 if (can_complete_type_without_circularity (rtype))
7747 complete_type (rtype);
7749 if (!COMPLETE_TYPE_P (rtype))
7751 cxx_incomplete_type_error (r, rtype);
7752 r = error_mark_node;
7756 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
7757 such a thing will already have been added to the field
7758 list by tsubst_enum in finish_member_declaration in the
7759 CLASSTYPE_NESTED_UTDS case above. */
7760 if (!(TREE_CODE (r) == TYPE_DECL
7761 && TREE_CODE (TREE_TYPE (r)) == ENUMERAL_TYPE
7762 && DECL_ARTIFICIAL (r)))
7764 set_current_access_from_decl (r);
7765 finish_member_declaration (r);
7772 if (TYPE_P (t) || DECL_CLASS_TEMPLATE_P (t))
7774 /* Build new CLASSTYPE_FRIEND_CLASSES. */
7776 tree friend_type = t;
7777 bool adjust_processing_template_decl = false;
7779 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
7781 /* template <class T> friend class C; */
7782 friend_type = tsubst_friend_class (friend_type, args);
7783 adjust_processing_template_decl = true;
7785 else if (TREE_CODE (friend_type) == UNBOUND_CLASS_TEMPLATE)
7787 /* template <class T> friend class C::D; */
7788 friend_type = tsubst (friend_type, args,
7789 tf_warning_or_error, NULL_TREE);
7790 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
7791 friend_type = TREE_TYPE (friend_type);
7792 adjust_processing_template_decl = true;
7794 else if (TREE_CODE (friend_type) == TYPENAME_TYPE)
7796 /* This could be either
7800 when dependent_type_p is false or
7802 template <class U> friend class T::C;
7805 friend_type = tsubst (friend_type, args,
7806 tf_warning_or_error, NULL_TREE);
7807 /* Bump processing_template_decl for correct
7808 dependent_type_p calculation. */
7809 ++processing_template_decl;
7810 if (dependent_type_p (friend_type))
7811 adjust_processing_template_decl = true;
7812 --processing_template_decl;
7814 else if (!CLASSTYPE_USE_TEMPLATE (friend_type)
7815 && hidden_name_p (TYPE_NAME (friend_type)))
7819 where C hasn't been declared yet. Let's lookup name
7820 from namespace scope directly, bypassing any name that
7821 come from dependent base class. */
7822 tree ns = decl_namespace_context (TYPE_MAIN_DECL (friend_type));
7824 /* The call to xref_tag_from_type does injection for friend
7826 push_nested_namespace (ns);
7828 xref_tag_from_type (friend_type, NULL_TREE,
7829 /*tag_scope=*/ts_current);
7830 pop_nested_namespace (ns);
7832 else if (uses_template_parms (friend_type))
7833 /* friend class C<T>; */
7834 friend_type = tsubst (friend_type, args,
7835 tf_warning_or_error, NULL_TREE);
7840 where C is already declared or
7842 friend class C<int>;
7844 We don't have to do anything in these cases. */
7846 if (adjust_processing_template_decl)
7847 /* Trick make_friend_class into realizing that the friend
7848 we're adding is a template, not an ordinary class. It's
7849 important that we use make_friend_class since it will
7850 perform some error-checking and output cross-reference
7852 ++processing_template_decl;
7854 if (friend_type != error_mark_node)
7855 make_friend_class (type, friend_type, /*complain=*/false);
7857 if (adjust_processing_template_decl)
7858 --processing_template_decl;
7862 /* Build new DECL_FRIENDLIST. */
7865 /* The file and line for this declaration, to
7866 assist in error message reporting. Since we
7867 called push_tinst_level above, we don't need to
7869 input_location = DECL_SOURCE_LOCATION (t);
7871 if (TREE_CODE (t) == TEMPLATE_DECL)
7873 ++processing_template_decl;
7874 push_deferring_access_checks (dk_no_check);
7877 r = tsubst_friend_function (t, args);
7878 add_friend (type, r, /*complain=*/false);
7879 if (TREE_CODE (t) == TEMPLATE_DECL)
7881 pop_deferring_access_checks ();
7882 --processing_template_decl;
7888 /* Set the file and line number information to whatever is given for
7889 the class itself. This puts error messages involving generated
7890 implicit functions at a predictable point, and the same point
7891 that would be used for non-template classes. */
7892 input_location = DECL_SOURCE_LOCATION (typedecl);
7894 unreverse_member_declarations (type);
7895 finish_struct_1 (type);
7896 TYPE_BEING_DEFINED (type) = 0;
7898 /* Now that the class is complete, instantiate default arguments for
7899 any member functions. We don't do this earlier because the
7900 default arguments may reference members of the class. */
7901 if (!PRIMARY_TEMPLATE_P (templ))
7902 for (t = TYPE_METHODS (type); t; t = TREE_CHAIN (t))
7903 if (TREE_CODE (t) == FUNCTION_DECL
7904 /* Implicitly generated member functions will not have template
7905 information; they are not instantiations, but instead are
7906 created "fresh" for each instantiation. */
7907 && DECL_TEMPLATE_INFO (t))
7908 tsubst_default_arguments (t);
7910 /* Some typedefs referenced from within the template code need to be access
7911 checked at template instantiation time, i.e now. These types were
7912 added to the template at parsing time. Let's get those and perform
7913 the access checks then. */
7914 perform_typedefs_access_check (pattern, args);
7915 perform_deferred_access_checks ();
7916 pop_nested_class ();
7917 maximum_field_alignment = saved_maximum_field_alignment;
7918 pop_from_top_level ();
7919 pop_deferring_access_checks ();
7922 /* The vtable for a template class can be emitted in any translation
7923 unit in which the class is instantiated. When there is no key
7924 method, however, finish_struct_1 will already have added TYPE to
7925 the keyed_classes list. */
7926 if (TYPE_CONTAINS_VPTR_P (type) && CLASSTYPE_KEY_METHOD (type))
7927 keyed_classes = tree_cons (NULL_TREE, type, keyed_classes);
7933 tsubst_template_arg (tree t, tree args, tsubst_flags_t complain, tree in_decl)
7939 else if (TYPE_P (t))
7940 r = tsubst (t, args, complain, in_decl);
7943 r = tsubst_expr (t, args, complain, in_decl,
7944 /*integral_constant_expression_p=*/true);
7945 r = fold_non_dependent_expr (r);
7950 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
7951 NONTYPE_ARGUMENT_PACK. */
7954 make_fnparm_pack (tree spec_parm)
7956 /* Collect all of the extra "packed" parameters into an
7960 tree argpack = make_node (NONTYPE_ARGUMENT_PACK);
7961 tree argtypepack = cxx_make_type (TYPE_ARGUMENT_PACK);
7962 int i, len = list_length (spec_parm);
7964 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
7965 parmvec = make_tree_vec (len);
7966 parmtypevec = make_tree_vec (len);
7967 for (i = 0; i < len; i++, spec_parm = TREE_CHAIN (spec_parm))
7969 TREE_VEC_ELT (parmvec, i) = spec_parm;
7970 TREE_VEC_ELT (parmtypevec, i) = TREE_TYPE (spec_parm);
7973 /* Build the argument packs. */
7974 SET_ARGUMENT_PACK_ARGS (argpack, parmvec);
7975 SET_ARGUMENT_PACK_ARGS (argtypepack, parmtypevec);
7976 TREE_TYPE (argpack) = argtypepack;
7981 /* Substitute ARGS into T, which is an pack expansion
7982 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
7983 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
7984 (if only a partial substitution could be performed) or
7985 ERROR_MARK_NODE if there was an error. */
7987 tsubst_pack_expansion (tree t, tree args, tsubst_flags_t complain,
7991 tree pack, packs = NULL_TREE, unsubstituted_packs = NULL_TREE;
7992 tree first_arg_pack; int i, len = -1;
7995 bool very_local_specializations = false;
7997 gcc_assert (PACK_EXPANSION_P (t));
7998 pattern = PACK_EXPANSION_PATTERN (t);
8000 /* Determine the argument packs that will instantiate the parameter
8001 packs used in the expansion expression. While we're at it,
8002 compute the number of arguments to be expanded and make sure it
8004 for (pack = PACK_EXPANSION_PARAMETER_PACKS (t); pack;
8005 pack = TREE_CHAIN (pack))
8007 tree parm_pack = TREE_VALUE (pack);
8008 tree arg_pack = NULL_TREE;
8009 tree orig_arg = NULL_TREE;
8011 if (TREE_CODE (parm_pack) == PARM_DECL)
8013 arg_pack = retrieve_local_specialization (parm_pack);
8014 if (arg_pack == NULL_TREE)
8016 /* This can happen for a parameter name used later in a function
8017 declaration (such as in a late-specified return type). Just
8018 make a dummy decl, since it's only used for its type. */
8019 gcc_assert (cp_unevaluated_operand != 0);
8020 arg_pack = tsubst_decl (parm_pack, args, complain);
8021 arg_pack = make_fnparm_pack (arg_pack);
8026 int level, idx, levels;
8027 template_parm_level_and_index (parm_pack, &level, &idx);
8029 levels = TMPL_ARGS_DEPTH (args);
8030 if (level <= levels)
8031 arg_pack = TMPL_ARG (args, level, idx);
8034 orig_arg = arg_pack;
8035 if (arg_pack && TREE_CODE (arg_pack) == ARGUMENT_PACK_SELECT)
8036 arg_pack = ARGUMENT_PACK_SELECT_FROM_PACK (arg_pack);
8038 if (arg_pack && !ARGUMENT_PACK_P (arg_pack))
8039 /* This can only happen if we forget to expand an argument
8040 pack somewhere else. Just return an error, silently. */
8042 result = make_tree_vec (1);
8043 TREE_VEC_ELT (result, 0) = error_mark_node;
8048 && TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack)) == 1
8049 && PACK_EXPANSION_P (TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0)))
8051 tree expansion = TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0);
8052 tree pattern = PACK_EXPANSION_PATTERN (expansion);
8053 if ((TYPE_P (pattern) && same_type_p (pattern, parm_pack))
8054 || (!TYPE_P (pattern) && cp_tree_equal (parm_pack, pattern)))
8055 /* The argument pack that the parameter maps to is just an
8056 expansion of the parameter itself, such as one would
8057 find in the implicit typedef of a class inside the
8058 class itself. Consider this parameter "unsubstituted",
8059 so that we will maintain the outer pack expansion. */
8060 arg_pack = NULL_TREE;
8066 TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack));
8068 /* It's all-or-nothing with incomplete argument packs. */
8069 if (incomplete && !ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
8070 return error_mark_node;
8072 if (ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
8078 first_arg_pack = arg_pack;
8080 else if (len != my_len)
8083 /* We got explicit args for some packs but not others;
8084 do nothing now and try again after deduction. */
8086 if (TREE_CODE (t) == TYPE_PACK_EXPANSION)
8087 error ("mismatched argument pack lengths while expanding "
8091 error ("mismatched argument pack lengths while expanding "
8094 return error_mark_node;
8097 /* Keep track of the parameter packs and their corresponding
8099 packs = tree_cons (parm_pack, arg_pack, packs);
8100 TREE_TYPE (packs) = orig_arg;
8103 /* We can't substitute for this parameter pack. */
8104 unsubstituted_packs = tree_cons (TREE_PURPOSE (pack),
8106 unsubstituted_packs);
8109 /* We cannot expand this expansion expression, because we don't have
8110 all of the argument packs we need. Substitute into the pattern
8111 and return a PACK_EXPANSION_*. The caller will need to deal with
8113 if (unsubstituted_packs)
8116 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
8117 new_pat = tsubst_expr (pattern, args, complain, in_decl,
8118 /*integral_constant_expression_p=*/false);
8120 new_pat = tsubst (pattern, args, complain, in_decl);
8121 return make_pack_expansion (new_pat);
8124 /* We could not find any argument packs that work. */
8126 return error_mark_node;
8128 if (!local_specializations)
8130 /* We're in a late-specified return type, so we don't have a local
8131 specializations table. Create one for doing this expansion. */
8132 very_local_specializations = true;
8133 local_specializations = htab_create (37,
8134 hash_local_specialization,
8135 eq_local_specializations,
8139 /* For each argument in each argument pack, substitute into the
8141 result = make_tree_vec (len + incomplete);
8142 for (i = 0; i < len + incomplete; ++i)
8144 /* For parameter pack, change the substitution of the parameter
8145 pack to the ith argument in its argument pack, then expand
8147 for (pack = packs; pack; pack = TREE_CHAIN (pack))
8149 tree parm = TREE_PURPOSE (pack);
8151 if (TREE_CODE (parm) == PARM_DECL)
8153 /* Select the Ith argument from the pack. */
8154 tree arg = make_node (ARGUMENT_PACK_SELECT);
8155 ARGUMENT_PACK_SELECT_FROM_PACK (arg) = TREE_VALUE (pack);
8156 ARGUMENT_PACK_SELECT_INDEX (arg) = i;
8158 register_local_specialization (arg, parm);
8164 template_parm_level_and_index (parm, &level, &idx);
8168 /* Select the Ith argument from the pack. */
8169 value = make_node (ARGUMENT_PACK_SELECT);
8170 ARGUMENT_PACK_SELECT_FROM_PACK (value) = TREE_VALUE (pack);
8171 ARGUMENT_PACK_SELECT_INDEX (value) = i;
8174 /* Update the corresponding argument. */
8175 TMPL_ARG (args, level, idx) = value;
8179 /* Substitute into the PATTERN with the altered arguments. */
8180 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
8181 TREE_VEC_ELT (result, i) =
8182 tsubst_expr (pattern, args, complain, in_decl,
8183 /*integral_constant_expression_p=*/false);
8185 TREE_VEC_ELT (result, i) = tsubst (pattern, args, complain, in_decl);
8188 /* When we have incomplete argument packs, the last "expanded"
8189 result is itself a pack expansion, which allows us
8190 to deduce more arguments. */
8191 TREE_VEC_ELT (result, i) =
8192 make_pack_expansion (TREE_VEC_ELT (result, i));
8194 if (TREE_VEC_ELT (result, i) == error_mark_node)
8196 result = error_mark_node;
8201 /* Update ARGS to restore the substitution from parameter packs to
8202 their argument packs. */
8203 for (pack = packs; pack; pack = TREE_CHAIN (pack))
8205 tree parm = TREE_PURPOSE (pack);
8207 if (TREE_CODE (parm) == PARM_DECL)
8208 register_local_specialization (TREE_TYPE (pack), parm);
8212 template_parm_level_and_index (parm, &level, &idx);
8214 /* Update the corresponding argument. */
8215 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
8216 TREE_VEC_ELT (TREE_VEC_ELT (args, level -1 ), idx) =
8219 TREE_VEC_ELT (args, idx) = TREE_TYPE (pack);
8223 if (very_local_specializations)
8225 htab_delete (local_specializations);
8226 local_specializations = NULL;
8232 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
8233 TMPL. We do this using DECL_PARM_INDEX, which should work even with
8234 parameter packs; all parms generated from a function parameter pack will
8235 have the same DECL_PARM_INDEX. */
8238 get_pattern_parm (tree parm, tree tmpl)
8240 tree pattern = DECL_TEMPLATE_RESULT (tmpl);
8243 if (DECL_ARTIFICIAL (parm))
8245 for (patparm = DECL_ARGUMENTS (pattern);
8246 patparm; patparm = TREE_CHAIN (patparm))
8247 if (DECL_ARTIFICIAL (patparm)
8248 && DECL_NAME (parm) == DECL_NAME (patparm))
8253 patparm = FUNCTION_FIRST_USER_PARM (DECL_TEMPLATE_RESULT (tmpl));
8254 patparm = chain_index (DECL_PARM_INDEX (parm)-1, patparm);
8255 gcc_assert (DECL_PARM_INDEX (patparm)
8256 == DECL_PARM_INDEX (parm));
8262 /* Substitute ARGS into the vector or list of template arguments T. */
8265 tsubst_template_args (tree t, tree args, tsubst_flags_t complain, tree in_decl)
8268 int len = TREE_VEC_LENGTH (t);
8269 int need_new = 0, i, expanded_len_adjust = 0, out;
8270 tree *elts = (tree *) alloca (len * sizeof (tree));
8272 for (i = 0; i < len; i++)
8274 tree orig_arg = TREE_VEC_ELT (t, i);
8277 if (TREE_CODE (orig_arg) == TREE_VEC)
8278 new_arg = tsubst_template_args (orig_arg, args, complain, in_decl);
8279 else if (PACK_EXPANSION_P (orig_arg))
8281 /* Substitute into an expansion expression. */
8282 new_arg = tsubst_pack_expansion (orig_arg, args, complain, in_decl);
8284 if (TREE_CODE (new_arg) == TREE_VEC)
8285 /* Add to the expanded length adjustment the number of
8286 expanded arguments. We subtract one from this
8287 measurement, because the argument pack expression
8288 itself is already counted as 1 in
8289 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
8290 the argument pack is empty. */
8291 expanded_len_adjust += TREE_VEC_LENGTH (new_arg) - 1;
8293 else if (ARGUMENT_PACK_P (orig_arg))
8295 /* Substitute into each of the arguments. */
8296 new_arg = TYPE_P (orig_arg)
8297 ? cxx_make_type (TREE_CODE (orig_arg))
8298 : make_node (TREE_CODE (orig_arg));
8300 SET_ARGUMENT_PACK_ARGS (
8302 tsubst_template_args (ARGUMENT_PACK_ARGS (orig_arg),
8303 args, complain, in_decl));
8305 if (ARGUMENT_PACK_ARGS (new_arg) == error_mark_node)
8306 new_arg = error_mark_node;
8308 if (TREE_CODE (new_arg) == NONTYPE_ARGUMENT_PACK) {
8309 TREE_TYPE (new_arg) = tsubst (TREE_TYPE (orig_arg), args,
8311 TREE_CONSTANT (new_arg) = TREE_CONSTANT (orig_arg);
8313 if (TREE_TYPE (new_arg) == error_mark_node)
8314 new_arg = error_mark_node;
8318 new_arg = tsubst_template_arg (orig_arg, args, complain, in_decl);
8320 if (new_arg == error_mark_node)
8321 return error_mark_node;
8324 if (new_arg != orig_arg)
8331 /* Make space for the expanded arguments coming from template
8333 t = make_tree_vec (len + expanded_len_adjust);
8334 for (i = 0, out = 0; i < len; i++)
8336 if ((PACK_EXPANSION_P (TREE_VEC_ELT (orig_t, i))
8337 || ARGUMENT_PACK_P (TREE_VEC_ELT (orig_t, i)))
8338 && TREE_CODE (elts[i]) == TREE_VEC)
8342 /* Now expand the template argument pack "in place". */
8343 for (idx = 0; idx < TREE_VEC_LENGTH (elts[i]); idx++, out++)
8344 TREE_VEC_ELT (t, out) = TREE_VEC_ELT (elts[i], idx);
8348 TREE_VEC_ELT (t, out) = elts[i];
8356 /* Return the result of substituting ARGS into the template parameters
8357 given by PARMS. If there are m levels of ARGS and m + n levels of
8358 PARMS, then the result will contain n levels of PARMS. For
8359 example, if PARMS is `template <class T> template <class U>
8360 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
8361 result will be `template <int*, double, class V>'. */
8364 tsubst_template_parms (tree parms, tree args, tsubst_flags_t complain)
8369 /* When substituting into a template, we must set
8370 PROCESSING_TEMPLATE_DECL as the template parameters may be
8371 dependent if they are based on one-another, and the dependency
8372 predicates are short-circuit outside of templates. */
8373 ++processing_template_decl;
8375 for (new_parms = &r;
8376 TMPL_PARMS_DEPTH (parms) > TMPL_ARGS_DEPTH (args);
8377 new_parms = &(TREE_CHAIN (*new_parms)),
8378 parms = TREE_CHAIN (parms))
8381 make_tree_vec (TREE_VEC_LENGTH (TREE_VALUE (parms)));
8384 for (i = 0; i < TREE_VEC_LENGTH (new_vec); ++i)
8390 if (parms == error_mark_node)
8393 tuple = TREE_VEC_ELT (TREE_VALUE (parms), i);
8395 if (tuple == error_mark_node)
8398 default_value = TREE_PURPOSE (tuple);
8399 parm_decl = TREE_VALUE (tuple);
8401 parm_decl = tsubst (parm_decl, args, complain, NULL_TREE);
8402 if (TREE_CODE (parm_decl) == PARM_DECL
8403 && invalid_nontype_parm_type_p (TREE_TYPE (parm_decl), complain))
8404 parm_decl = error_mark_node;
8405 default_value = tsubst_template_arg (default_value, args,
8406 complain, NULL_TREE);
8408 tuple = build_tree_list (default_value, parm_decl);
8409 TREE_VEC_ELT (new_vec, i) = tuple;
8413 tree_cons (size_int (TMPL_PARMS_DEPTH (parms)
8414 - TMPL_ARGS_DEPTH (args)),
8415 new_vec, NULL_TREE);
8418 --processing_template_decl;
8423 /* Substitute the ARGS into the indicated aggregate (or enumeration)
8424 type T. If T is not an aggregate or enumeration type, it is
8425 handled as if by tsubst. IN_DECL is as for tsubst. If
8426 ENTERING_SCOPE is nonzero, T is the context for a template which
8427 we are presently tsubst'ing. Return the substituted value. */
8430 tsubst_aggr_type (tree t,
8432 tsubst_flags_t complain,
8439 switch (TREE_CODE (t))
8442 if (TYPE_PTRMEMFUNC_P (t))
8443 return tsubst (TYPE_PTRMEMFUNC_FN_TYPE (t), args, complain, in_decl);
8445 /* Else fall through. */
8448 if (TYPE_TEMPLATE_INFO (t) && uses_template_parms (t))
8453 int saved_unevaluated_operand;
8454 int saved_inhibit_evaluation_warnings;
8456 /* In "sizeof(X<I>)" we need to evaluate "I". */
8457 saved_unevaluated_operand = cp_unevaluated_operand;
8458 cp_unevaluated_operand = 0;
8459 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
8460 c_inhibit_evaluation_warnings = 0;
8462 /* First, determine the context for the type we are looking
8464 context = TYPE_CONTEXT (t);
8467 context = tsubst_aggr_type (context, args, complain,
8468 in_decl, /*entering_scope=*/1);
8469 /* If context is a nested class inside a class template,
8470 it may still need to be instantiated (c++/33959). */
8471 if (TYPE_P (context))
8472 context = complete_type (context);
8475 /* Then, figure out what arguments are appropriate for the
8476 type we are trying to find. For example, given:
8478 template <class T> struct S;
8479 template <class T, class U> void f(T, U) { S<U> su; }
8481 and supposing that we are instantiating f<int, double>,
8482 then our ARGS will be {int, double}, but, when looking up
8483 S we only want {double}. */
8484 argvec = tsubst_template_args (TYPE_TI_ARGS (t), args,
8486 if (argvec == error_mark_node)
8487 r = error_mark_node;
8490 r = lookup_template_class (t, argvec, in_decl, context,
8491 entering_scope, complain);
8492 r = cp_build_qualified_type_real (r, TYPE_QUALS (t), complain);
8495 cp_unevaluated_operand = saved_unevaluated_operand;
8496 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
8501 /* This is not a template type, so there's nothing to do. */
8505 return tsubst (t, args, complain, in_decl);
8509 /* Substitute into the default argument ARG (a default argument for
8510 FN), which has the indicated TYPE. */
8513 tsubst_default_argument (tree fn, tree type, tree arg)
8515 tree saved_class_ptr = NULL_TREE;
8516 tree saved_class_ref = NULL_TREE;
8518 /* This default argument came from a template. Instantiate the
8519 default argument here, not in tsubst. In the case of
8528 we must be careful to do name lookup in the scope of S<T>,
8529 rather than in the current class. */
8530 push_access_scope (fn);
8531 /* The "this" pointer is not valid in a default argument. */
8534 saved_class_ptr = current_class_ptr;
8535 cp_function_chain->x_current_class_ptr = NULL_TREE;
8536 saved_class_ref = current_class_ref;
8537 cp_function_chain->x_current_class_ref = NULL_TREE;
8540 push_deferring_access_checks(dk_no_deferred);
8541 /* The default argument expression may cause implicitly defined
8542 member functions to be synthesized, which will result in garbage
8543 collection. We must treat this situation as if we were within
8544 the body of function so as to avoid collecting live data on the
8547 arg = tsubst_expr (arg, DECL_TI_ARGS (fn),
8548 tf_warning_or_error, NULL_TREE,
8549 /*integral_constant_expression_p=*/false);
8551 pop_deferring_access_checks();
8553 /* Restore the "this" pointer. */
8556 cp_function_chain->x_current_class_ptr = saved_class_ptr;
8557 cp_function_chain->x_current_class_ref = saved_class_ref;
8560 /* Make sure the default argument is reasonable. */
8561 arg = check_default_argument (type, arg);
8563 pop_access_scope (fn);
8568 /* Substitute into all the default arguments for FN. */
8571 tsubst_default_arguments (tree fn)
8576 tmpl_args = DECL_TI_ARGS (fn);
8578 /* If this function is not yet instantiated, we certainly don't need
8579 its default arguments. */
8580 if (uses_template_parms (tmpl_args))
8583 for (arg = TYPE_ARG_TYPES (TREE_TYPE (fn));
8585 arg = TREE_CHAIN (arg))
8586 if (TREE_PURPOSE (arg))
8587 TREE_PURPOSE (arg) = tsubst_default_argument (fn,
8589 TREE_PURPOSE (arg));
8592 /* Substitute the ARGS into the T, which is a _DECL. Return the
8593 result of the substitution. Issue error and warning messages under
8594 control of COMPLAIN. */
8597 tsubst_decl (tree t, tree args, tsubst_flags_t complain)
8599 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
8600 location_t saved_loc;
8605 /* Set the filename and linenumber to improve error-reporting. */
8606 saved_loc = input_location;
8607 input_location = DECL_SOURCE_LOCATION (t);
8609 switch (TREE_CODE (t))
8613 /* We can get here when processing a member function template,
8614 member class template, or template template parameter. */
8615 tree decl = DECL_TEMPLATE_RESULT (t);
8620 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
8622 /* Template template parameter is treated here. */
8623 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8624 if (new_type == error_mark_node)
8625 RETURN (error_mark_node);
8628 TREE_CHAIN (r) = NULL_TREE;
8629 TREE_TYPE (r) = new_type;
8630 DECL_TEMPLATE_RESULT (r)
8631 = build_decl (DECL_SOURCE_LOCATION (decl),
8632 TYPE_DECL, DECL_NAME (decl), new_type);
8633 DECL_TEMPLATE_PARMS (r)
8634 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
8636 TYPE_NAME (new_type) = r;
8640 /* We might already have an instance of this template.
8641 The ARGS are for the surrounding class type, so the
8642 full args contain the tsubst'd args for the context,
8643 plus the innermost args from the template decl. */
8644 tmpl_args = DECL_CLASS_TEMPLATE_P (t)
8645 ? CLASSTYPE_TI_ARGS (TREE_TYPE (t))
8646 : DECL_TI_ARGS (DECL_TEMPLATE_RESULT (t));
8647 /* Because this is a template, the arguments will still be
8648 dependent, even after substitution. If
8649 PROCESSING_TEMPLATE_DECL is not set, the dependency
8650 predicates will short-circuit. */
8651 ++processing_template_decl;
8652 full_args = tsubst_template_args (tmpl_args, args,
8654 --processing_template_decl;
8655 if (full_args == error_mark_node)
8656 RETURN (error_mark_node);
8658 /* If this is a default template template argument,
8659 tsubst might not have changed anything. */
8660 if (full_args == tmpl_args)
8663 hash = hash_tmpl_and_args (t, full_args);
8664 spec = retrieve_specialization (t, full_args, hash);
8665 if (spec != NULL_TREE)
8671 /* Make a new template decl. It will be similar to the
8672 original, but will record the current template arguments.
8673 We also create a new function declaration, which is just
8674 like the old one, but points to this new template, rather
8675 than the old one. */
8677 gcc_assert (DECL_LANG_SPECIFIC (r) != 0);
8678 TREE_CHAIN (r) = NULL_TREE;
8680 DECL_TEMPLATE_INFO (r) = build_template_info (t, args);
8682 if (TREE_CODE (decl) == TYPE_DECL)
8685 ++processing_template_decl;
8686 new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8687 --processing_template_decl;
8688 if (new_type == error_mark_node)
8689 RETURN (error_mark_node);
8691 TREE_TYPE (r) = new_type;
8692 CLASSTYPE_TI_TEMPLATE (new_type) = r;
8693 DECL_TEMPLATE_RESULT (r) = TYPE_MAIN_DECL (new_type);
8694 DECL_TI_ARGS (r) = CLASSTYPE_TI_ARGS (new_type);
8695 DECL_CONTEXT (r) = TYPE_CONTEXT (new_type);
8700 ++processing_template_decl;
8701 new_decl = tsubst (decl, args, complain, in_decl);
8702 --processing_template_decl;
8703 if (new_decl == error_mark_node)
8704 RETURN (error_mark_node);
8706 DECL_TEMPLATE_RESULT (r) = new_decl;
8707 DECL_TI_TEMPLATE (new_decl) = r;
8708 TREE_TYPE (r) = TREE_TYPE (new_decl);
8709 DECL_TI_ARGS (r) = DECL_TI_ARGS (new_decl);
8710 DECL_CONTEXT (r) = DECL_CONTEXT (new_decl);
8713 SET_DECL_IMPLICIT_INSTANTIATION (r);
8714 DECL_TEMPLATE_INSTANTIATIONS (r) = NULL_TREE;
8715 DECL_TEMPLATE_SPECIALIZATIONS (r) = NULL_TREE;
8717 /* The template parameters for this new template are all the
8718 template parameters for the old template, except the
8719 outermost level of parameters. */
8720 DECL_TEMPLATE_PARMS (r)
8721 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
8724 if (PRIMARY_TEMPLATE_P (t))
8725 DECL_PRIMARY_TEMPLATE (r) = r;
8727 if (TREE_CODE (decl) != TYPE_DECL)
8728 /* Record this non-type partial instantiation. */
8729 register_specialization (r, t,
8730 DECL_TI_ARGS (DECL_TEMPLATE_RESULT (r)),
8738 tree argvec = NULL_TREE;
8746 /* Nobody should be tsubst'ing into non-template functions. */
8747 gcc_assert (DECL_TEMPLATE_INFO (t) != NULL_TREE);
8749 if (TREE_CODE (DECL_TI_TEMPLATE (t)) == TEMPLATE_DECL)
8754 /* If T is not dependent, just return it. We have to
8755 increment PROCESSING_TEMPLATE_DECL because
8756 value_dependent_expression_p assumes that nothing is
8757 dependent when PROCESSING_TEMPLATE_DECL is zero. */
8758 ++processing_template_decl;
8759 dependent_p = value_dependent_expression_p (t);
8760 --processing_template_decl;
8764 /* Calculate the most general template of which R is a
8765 specialization, and the complete set of arguments used to
8767 gen_tmpl = most_general_template (DECL_TI_TEMPLATE (t));
8768 argvec = tsubst_template_args (DECL_TI_ARGS
8769 (DECL_TEMPLATE_RESULT (gen_tmpl)),
8770 args, complain, in_decl);
8772 /* Check to see if we already have this specialization. */
8773 hash = hash_tmpl_and_args (gen_tmpl, argvec);
8774 spec = retrieve_specialization (gen_tmpl, argvec, hash);
8782 /* We can see more levels of arguments than parameters if
8783 there was a specialization of a member template, like
8786 template <class T> struct S { template <class U> void f(); }
8787 template <> template <class U> void S<int>::f(U);
8789 Here, we'll be substituting into the specialization,
8790 because that's where we can find the code we actually
8791 want to generate, but we'll have enough arguments for
8792 the most general template.
8794 We also deal with the peculiar case:
8796 template <class T> struct S {
8797 template <class U> friend void f();
8799 template <class U> void f() {}
8801 template void f<double>();
8803 Here, the ARGS for the instantiation of will be {int,
8804 double}. But, we only need as many ARGS as there are
8805 levels of template parameters in CODE_PATTERN. We are
8806 careful not to get fooled into reducing the ARGS in
8809 template <class T> struct S { template <class U> void f(U); }
8810 template <class T> template <> void S<T>::f(int) {}
8812 which we can spot because the pattern will be a
8813 specialization in this case. */
8814 args_depth = TMPL_ARGS_DEPTH (args);
8816 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (t)));
8817 if (args_depth > parms_depth
8818 && !DECL_TEMPLATE_SPECIALIZATION (t))
8819 args = get_innermost_template_args (args, parms_depth);
8823 /* This special case arises when we have something like this:
8825 template <class T> struct S {
8826 friend void f<int>(int, double);
8829 Here, the DECL_TI_TEMPLATE for the friend declaration
8830 will be an IDENTIFIER_NODE. We are being called from
8831 tsubst_friend_function, and we want only to create a
8832 new decl (R) with appropriate types so that we can call
8833 determine_specialization. */
8834 gen_tmpl = NULL_TREE;
8837 if (DECL_CLASS_SCOPE_P (t))
8839 if (DECL_NAME (t) == constructor_name (DECL_CONTEXT (t)))
8843 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args,
8844 complain, t, /*entering_scope=*/1);
8849 ctx = DECL_CONTEXT (t);
8851 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8852 if (type == error_mark_node)
8853 RETURN (error_mark_node);
8855 /* We do NOT check for matching decls pushed separately at this
8856 point, as they may not represent instantiations of this
8857 template, and in any case are considered separate under the
8860 DECL_USE_TEMPLATE (r) = 0;
8861 TREE_TYPE (r) = type;
8862 /* Clear out the mangled name and RTL for the instantiation. */
8863 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
8864 SET_DECL_RTL (r, NULL_RTX);
8865 /* Leave DECL_INITIAL set on deleted instantiations. */
8866 if (!DECL_DELETED_FN (r))
8867 DECL_INITIAL (r) = NULL_TREE;
8868 DECL_CONTEXT (r) = ctx;
8870 if (member && DECL_CONV_FN_P (r))
8871 /* Type-conversion operator. Reconstruct the name, in
8872 case it's the name of one of the template's parameters. */
8873 DECL_NAME (r) = mangle_conv_op_name_for_type (TREE_TYPE (type));
8875 DECL_ARGUMENTS (r) = tsubst (DECL_ARGUMENTS (t), args,
8877 DECL_RESULT (r) = NULL_TREE;
8879 TREE_STATIC (r) = 0;
8880 TREE_PUBLIC (r) = TREE_PUBLIC (t);
8881 DECL_EXTERNAL (r) = 1;
8882 /* If this is an instantiation of a function with internal
8883 linkage, we already know what object file linkage will be
8884 assigned to the instantiation. */
8885 DECL_INTERFACE_KNOWN (r) = !TREE_PUBLIC (r);
8886 DECL_DEFER_OUTPUT (r) = 0;
8887 TREE_CHAIN (r) = NULL_TREE;
8888 DECL_PENDING_INLINE_INFO (r) = 0;
8889 DECL_PENDING_INLINE_P (r) = 0;
8890 DECL_SAVED_TREE (r) = NULL_TREE;
8891 DECL_STRUCT_FUNCTION (r) = NULL;
8893 /* We'll re-clone as appropriate in instantiate_template. */
8894 DECL_CLONED_FUNCTION (r) = NULL_TREE;
8896 /* If we aren't complaining now, return on error before we register
8897 the specialization so that we'll complain eventually. */
8898 if ((complain & tf_error) == 0
8899 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
8900 && !grok_op_properties (r, /*complain=*/false))
8901 RETURN (error_mark_node);
8903 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
8904 this in the special friend case mentioned above where
8905 GEN_TMPL is NULL. */
8908 DECL_TEMPLATE_INFO (r)
8909 = build_template_info (gen_tmpl, argvec);
8910 SET_DECL_IMPLICIT_INSTANTIATION (r);
8911 register_specialization (r, gen_tmpl, argvec, false, hash);
8913 /* We're not supposed to instantiate default arguments
8914 until they are called, for a template. But, for a
8917 template <class T> void f ()
8918 { extern void g(int i = T()); }
8920 we should do the substitution when the template is
8921 instantiated. We handle the member function case in
8922 instantiate_class_template since the default arguments
8923 might refer to other members of the class. */
8925 && !PRIMARY_TEMPLATE_P (gen_tmpl)
8926 && !uses_template_parms (argvec))
8927 tsubst_default_arguments (r);
8930 DECL_TEMPLATE_INFO (r) = NULL_TREE;
8932 /* Copy the list of befriending classes. */
8933 for (friends = &DECL_BEFRIENDING_CLASSES (r);
8935 friends = &TREE_CHAIN (*friends))
8937 *friends = copy_node (*friends);
8938 TREE_VALUE (*friends) = tsubst (TREE_VALUE (*friends),
8943 if (DECL_CONSTRUCTOR_P (r) || DECL_DESTRUCTOR_P (r))
8945 maybe_retrofit_in_chrg (r);
8946 if (DECL_CONSTRUCTOR_P (r))
8947 grok_ctor_properties (ctx, r);
8948 /* If this is an instantiation of a member template, clone it.
8949 If it isn't, that'll be handled by
8950 clone_constructors_and_destructors. */
8951 if (PRIMARY_TEMPLATE_P (gen_tmpl))
8952 clone_function_decl (r, /*update_method_vec_p=*/0);
8954 else if ((complain & tf_error) != 0
8955 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
8956 && !grok_op_properties (r, /*complain=*/true))
8957 RETURN (error_mark_node);
8959 if (DECL_FRIEND_P (t) && DECL_FRIEND_CONTEXT (t))
8960 SET_DECL_FRIEND_CONTEXT (r,
8961 tsubst (DECL_FRIEND_CONTEXT (t),
8962 args, complain, in_decl));
8964 /* Possibly limit visibility based on template args. */
8965 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
8966 if (DECL_VISIBILITY_SPECIFIED (t))
8968 DECL_VISIBILITY_SPECIFIED (r) = 0;
8970 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
8972 determine_visibility (r);
8973 if (DECL_DEFAULTED_OUTSIDE_CLASS_P (r)
8974 && !processing_template_decl)
8975 defaulted_late_check (r);
8977 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
8978 args, complain, in_decl);
8984 tree type = NULL_TREE;
8986 tree expanded_types = NULL_TREE;
8987 tree prev_r = NULL_TREE;
8988 tree first_r = NULL_TREE;
8990 if (FUNCTION_PARAMETER_PACK_P (t))
8992 /* If there is a local specialization that isn't a
8993 parameter pack, it means that we're doing a "simple"
8994 substitution from inside tsubst_pack_expansion. Just
8995 return the local specialization (which will be a single
8997 tree spec = retrieve_local_specialization (t);
8999 && TREE_CODE (spec) == PARM_DECL
9000 && TREE_CODE (TREE_TYPE (spec)) != TYPE_PACK_EXPANSION)
9003 /* Expand the TYPE_PACK_EXPANSION that provides the types for
9004 the parameters in this function parameter pack. */
9005 expanded_types = tsubst_pack_expansion (TREE_TYPE (t), args,
9007 if (TREE_CODE (expanded_types) == TREE_VEC)
9009 len = TREE_VEC_LENGTH (expanded_types);
9011 /* Zero-length parameter packs are boring. Just substitute
9014 RETURN (tsubst (TREE_CHAIN (t), args, complain,
9019 /* All we did was update the type. Make a note of that. */
9020 type = expanded_types;
9021 expanded_types = NULL_TREE;
9025 /* Loop through all of the parameter's we'll build. When T is
9026 a function parameter pack, LEN is the number of expanded
9027 types in EXPANDED_TYPES; otherwise, LEN is 1. */
9029 for (i = 0; i < len; ++i)
9033 if (DECL_TEMPLATE_PARM_P (t))
9034 SET_DECL_TEMPLATE_PARM_P (r);
9036 /* An argument of a function parameter pack is not a parameter
9038 FUNCTION_PARAMETER_PACK_P (r) = false;
9041 /* We're on the Ith parameter of the function parameter
9044 /* Get the Ith type. */
9045 type = TREE_VEC_ELT (expanded_types, i);
9048 /* Rename the parameter to include the index. */
9050 make_ith_pack_parameter_name (DECL_NAME (r), i);
9053 /* We're dealing with a normal parameter. */
9054 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9056 type = type_decays_to (type);
9057 TREE_TYPE (r) = type;
9058 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
9060 if (DECL_INITIAL (r))
9062 if (TREE_CODE (DECL_INITIAL (r)) != TEMPLATE_PARM_INDEX)
9063 DECL_INITIAL (r) = TREE_TYPE (r);
9065 DECL_INITIAL (r) = tsubst (DECL_INITIAL (r), args,
9069 DECL_CONTEXT (r) = NULL_TREE;
9071 if (!DECL_TEMPLATE_PARM_P (r))
9072 DECL_ARG_TYPE (r) = type_passed_as (type);
9074 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
9075 args, complain, in_decl);
9077 /* Keep track of the first new parameter we
9078 generate. That's what will be returned to the
9083 /* Build a proper chain of parameters when substituting
9084 into a function parameter pack. */
9086 TREE_CHAIN (prev_r) = r;
9090 TREE_CHAIN (r) = tsubst (TREE_CHAIN (t), args,
9091 complain, TREE_CHAIN (t));
9093 /* FIRST_R contains the start of the chain we've built. */
9103 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9104 if (type == error_mark_node)
9105 RETURN (error_mark_node);
9106 TREE_TYPE (r) = type;
9107 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
9109 /* DECL_INITIAL gives the number of bits in a bit-field. */
9111 = tsubst_expr (DECL_INITIAL (t), args,
9113 /*integral_constant_expression_p=*/true);
9114 /* We don't have to set DECL_CONTEXT here; it is set by
9115 finish_member_declaration. */
9116 TREE_CHAIN (r) = NULL_TREE;
9117 if (VOID_TYPE_P (type))
9118 error ("instantiation of %q+D as type %qT", r, type);
9120 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
9121 args, complain, in_decl);
9126 /* We reach here only for member using decls. */
9127 if (DECL_DEPENDENT_P (t))
9129 r = do_class_using_decl
9130 (tsubst_copy (USING_DECL_SCOPE (t), args, complain, in_decl),
9131 tsubst_copy (DECL_NAME (t), args, complain, in_decl));
9133 r = error_mark_node;
9136 TREE_PROTECTED (r) = TREE_PROTECTED (t);
9137 TREE_PRIVATE (r) = TREE_PRIVATE (t);
9143 TREE_CHAIN (r) = NULL_TREE;
9150 tree argvec = NULL_TREE;
9151 tree gen_tmpl = NULL_TREE;
9153 tree tmpl = NULL_TREE;
9155 tree type = NULL_TREE;
9158 if (TREE_CODE (t) == TYPE_DECL
9159 && t == TYPE_MAIN_DECL (TREE_TYPE (t)))
9161 /* If this is the canonical decl, we don't have to
9162 mess with instantiations, and often we can't (for
9163 typename, template type parms and such). Note that
9164 TYPE_NAME is not correct for the above test if
9165 we've copied the type for a typedef. */
9166 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9167 if (type == error_mark_node)
9168 RETURN (error_mark_node);
9169 r = TYPE_NAME (type);
9173 /* Check to see if we already have the specialization we
9176 if (DECL_CLASS_SCOPE_P (t) || DECL_NAMESPACE_SCOPE_P (t))
9178 /* T is a static data member or namespace-scope entity.
9179 We have to substitute into namespace-scope variables
9180 (even though such entities are never templates) because
9183 template <class T> void f() { extern T t; }
9185 where the entity referenced is not known until
9186 instantiation time. */
9188 ctx = DECL_CONTEXT (t);
9189 if (DECL_CLASS_SCOPE_P (t))
9191 ctx = tsubst_aggr_type (ctx, args,
9193 in_decl, /*entering_scope=*/1);
9194 /* If CTX is unchanged, then T is in fact the
9195 specialization we want. That situation occurs when
9196 referencing a static data member within in its own
9197 class. We can use pointer equality, rather than
9198 same_type_p, because DECL_CONTEXT is always
9200 if (ctx == DECL_CONTEXT (t))
9206 tmpl = DECL_TI_TEMPLATE (t);
9207 gen_tmpl = most_general_template (tmpl);
9208 argvec = tsubst (DECL_TI_ARGS (t), args, complain, in_decl);
9209 hash = hash_tmpl_and_args (gen_tmpl, argvec);
9210 spec = retrieve_specialization (gen_tmpl, argvec, hash);
9215 /* A local variable. */
9217 /* Subsequent calls to pushdecl will fill this in. */
9219 spec = retrieve_local_specialization (t);
9221 /* If we already have the specialization we need, there is
9222 nothing more to do. */
9229 /* Create a new node for the specialization we need. */
9231 if (type == NULL_TREE)
9232 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9233 if (TREE_CODE (r) == VAR_DECL)
9235 /* Even if the original location is out of scope, the
9236 newly substituted one is not. */
9237 DECL_DEAD_FOR_LOCAL (r) = 0;
9238 DECL_INITIALIZED_P (r) = 0;
9239 DECL_TEMPLATE_INSTANTIATED (r) = 0;
9240 if (type == error_mark_node)
9241 RETURN (error_mark_node);
9242 if (TREE_CODE (type) == FUNCTION_TYPE)
9244 /* It may seem that this case cannot occur, since:
9249 declares a function, not a variable. However:
9252 template <typename T> void g() { T t; }
9253 template void g<f>();
9255 is an attempt to declare a variable with function
9257 error ("variable %qD has function type",
9258 /* R is not yet sufficiently initialized, so we
9259 just use its name. */
9261 RETURN (error_mark_node);
9263 type = complete_type (type);
9264 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r)
9265 = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (t);
9266 type = check_var_type (DECL_NAME (r), type);
9268 if (DECL_HAS_VALUE_EXPR_P (t))
9270 tree ve = DECL_VALUE_EXPR (t);
9271 ve = tsubst_expr (ve, args, complain, in_decl,
9272 /*constant_expression_p=*/false);
9273 SET_DECL_VALUE_EXPR (r, ve);
9276 else if (DECL_SELF_REFERENCE_P (t))
9277 SET_DECL_SELF_REFERENCE_P (r);
9278 TREE_TYPE (r) = type;
9279 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
9280 DECL_CONTEXT (r) = ctx;
9281 /* Clear out the mangled name and RTL for the instantiation. */
9282 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
9283 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
9284 SET_DECL_RTL (r, NULL_RTX);
9285 /* The initializer must not be expanded until it is required;
9287 DECL_INITIAL (r) = NULL_TREE;
9288 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
9289 SET_DECL_RTL (r, NULL_RTX);
9290 DECL_SIZE (r) = DECL_SIZE_UNIT (r) = 0;
9291 if (TREE_CODE (r) == VAR_DECL)
9293 /* Possibly limit visibility based on template args. */
9294 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
9295 if (DECL_VISIBILITY_SPECIFIED (t))
9297 DECL_VISIBILITY_SPECIFIED (r) = 0;
9299 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
9301 determine_visibility (r);
9303 /* Preserve a typedef that names a type. */
9304 else if (TREE_CODE (r) == TYPE_DECL
9305 && DECL_ORIGINAL_TYPE (t)
9306 && type != error_mark_node)
9308 DECL_ORIGINAL_TYPE (r) = tsubst (DECL_ORIGINAL_TYPE (t),
9309 args, complain, in_decl);
9310 TREE_TYPE (r) = type = build_variant_type_copy (type);
9311 TYPE_NAME (type) = r;
9316 /* A static data member declaration is always marked
9317 external when it is declared in-class, even if an
9318 initializer is present. We mimic the non-template
9320 DECL_EXTERNAL (r) = 1;
9322 register_specialization (r, gen_tmpl, argvec, false, hash);
9323 DECL_TEMPLATE_INFO (r) = build_template_info (tmpl, argvec);
9324 SET_DECL_IMPLICIT_INSTANTIATION (r);
9326 else if (cp_unevaluated_operand)
9328 /* We're substituting this var in a decltype outside of its
9329 scope, such as for a lambda return type. Don't add it to
9330 local_specializations, do perform auto deduction. */
9331 tree auto_node = type_uses_auto (type);
9333 = tsubst_expr (DECL_INITIAL (t), args, complain, in_decl,
9334 /*constant_expression_p=*/false);
9336 if (auto_node && init && describable_type (init))
9338 type = do_auto_deduction (type, init, auto_node);
9339 TREE_TYPE (r) = type;
9343 register_local_specialization (r, t);
9345 TREE_CHAIN (r) = NULL_TREE;
9347 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r),
9348 (int) ATTR_FLAG_TYPE_IN_PLACE,
9349 args, complain, in_decl);
9360 /* Restore the file and line information. */
9361 input_location = saved_loc;
9366 /* Substitute into the ARG_TYPES of a function type. */
9369 tsubst_arg_types (tree arg_types,
9371 tsubst_flags_t complain,
9374 tree remaining_arg_types;
9375 tree type = NULL_TREE;
9377 tree expanded_args = NULL_TREE;
9380 if (!arg_types || arg_types == void_list_node)
9383 remaining_arg_types = tsubst_arg_types (TREE_CHAIN (arg_types),
9384 args, complain, in_decl);
9385 if (remaining_arg_types == error_mark_node)
9386 return error_mark_node;
9388 if (PACK_EXPANSION_P (TREE_VALUE (arg_types)))
9390 /* For a pack expansion, perform substitution on the
9391 entire expression. Later on, we'll handle the arguments
9393 expanded_args = tsubst_pack_expansion (TREE_VALUE (arg_types),
9394 args, complain, in_decl);
9396 if (TREE_CODE (expanded_args) == TREE_VEC)
9397 /* So that we'll spin through the parameters, one by one. */
9398 i = TREE_VEC_LENGTH (expanded_args);
9401 /* We only partially substituted into the parameter
9402 pack. Our type is TYPE_PACK_EXPANSION. */
9403 type = expanded_args;
9404 expanded_args = NULL_TREE;
9412 type = TREE_VEC_ELT (expanded_args, i);
9414 type = tsubst (TREE_VALUE (arg_types), args, complain, in_decl);
9416 if (type == error_mark_node)
9417 return error_mark_node;
9418 if (VOID_TYPE_P (type))
9420 if (complain & tf_error)
9422 error ("invalid parameter type %qT", type);
9424 error ("in declaration %q+D", in_decl);
9426 return error_mark_node;
9429 /* Do array-to-pointer, function-to-pointer conversion, and ignore
9430 top-level qualifiers as required. */
9431 type = TYPE_MAIN_VARIANT (type_decays_to (type));
9433 /* We do not substitute into default arguments here. The standard
9434 mandates that they be instantiated only when needed, which is
9435 done in build_over_call. */
9436 default_arg = TREE_PURPOSE (arg_types);
9438 if (default_arg && TREE_CODE (default_arg) == DEFAULT_ARG)
9440 /* We've instantiated a template before its default arguments
9441 have been parsed. This can happen for a nested template
9442 class, and is not an error unless we require the default
9443 argument in a call of this function. */
9444 remaining_arg_types =
9445 tree_cons (default_arg, type, remaining_arg_types);
9446 VEC_safe_push (tree, gc, DEFARG_INSTANTIATIONS (default_arg),
9447 remaining_arg_types);
9450 remaining_arg_types =
9451 hash_tree_cons (default_arg, type, remaining_arg_types);
9454 return remaining_arg_types;
9457 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
9458 *not* handle the exception-specification for FNTYPE, because the
9459 initial substitution of explicitly provided template parameters
9460 during argument deduction forbids substitution into the
9461 exception-specification:
9465 All references in the function type of the function template to the
9466 corresponding template parameters are replaced by the specified tem-
9467 plate argument values. If a substitution in a template parameter or
9468 in the function type of the function template results in an invalid
9469 type, type deduction fails. [Note: The equivalent substitution in
9470 exception specifications is done only when the function is instanti-
9471 ated, at which point a program is ill-formed if the substitution
9472 results in an invalid type.] */
9475 tsubst_function_type (tree t,
9477 tsubst_flags_t complain,
9484 /* The TYPE_CONTEXT is not used for function/method types. */
9485 gcc_assert (TYPE_CONTEXT (t) == NULL_TREE);
9487 /* Substitute the return type. */
9488 return_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9489 if (return_type == error_mark_node)
9490 return error_mark_node;
9491 /* The standard does not presently indicate that creation of a
9492 function type with an invalid return type is a deduction failure.
9493 However, that is clearly analogous to creating an array of "void"
9494 or a reference to a reference. This is core issue #486. */
9495 if (TREE_CODE (return_type) == ARRAY_TYPE
9496 || TREE_CODE (return_type) == FUNCTION_TYPE)
9498 if (complain & tf_error)
9500 if (TREE_CODE (return_type) == ARRAY_TYPE)
9501 error ("function returning an array");
9503 error ("function returning a function");
9505 return error_mark_node;
9508 /* Substitute the argument types. */
9509 arg_types = tsubst_arg_types (TYPE_ARG_TYPES (t), args,
9511 if (arg_types == error_mark_node)
9512 return error_mark_node;
9514 /* Construct a new type node and return it. */
9515 if (TREE_CODE (t) == FUNCTION_TYPE)
9516 fntype = build_function_type (return_type, arg_types);
9519 tree r = TREE_TYPE (TREE_VALUE (arg_types));
9520 if (! MAYBE_CLASS_TYPE_P (r))
9524 Type deduction may fail for any of the following
9527 -- Attempting to create "pointer to member of T" when T
9528 is not a class type. */
9529 if (complain & tf_error)
9530 error ("creating pointer to member function of non-class type %qT",
9532 return error_mark_node;
9535 fntype = build_method_type_directly (r, return_type,
9536 TREE_CHAIN (arg_types));
9538 fntype = cp_build_qualified_type_real (fntype, TYPE_QUALS (t), complain);
9539 fntype = cp_build_type_attribute_variant (fntype, TYPE_ATTRIBUTES (t));
9544 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
9545 ARGS into that specification, and return the substituted
9546 specification. If there is no specification, return NULL_TREE. */
9549 tsubst_exception_specification (tree fntype,
9551 tsubst_flags_t complain,
9557 specs = TYPE_RAISES_EXCEPTIONS (fntype);
9558 new_specs = NULL_TREE;
9561 if (! TREE_VALUE (specs))
9568 tree expanded_specs = NULL_TREE;
9570 if (PACK_EXPANSION_P (TREE_VALUE (specs)))
9572 /* Expand the pack expansion type. */
9573 expanded_specs = tsubst_pack_expansion (TREE_VALUE (specs),
9577 if (expanded_specs == error_mark_node)
9578 return error_mark_node;
9579 else if (TREE_CODE (expanded_specs) == TREE_VEC)
9580 len = TREE_VEC_LENGTH (expanded_specs);
9583 /* We're substituting into a member template, so
9584 we got a TYPE_PACK_EXPANSION back. Add that
9585 expansion and move on. */
9586 gcc_assert (TREE_CODE (expanded_specs)
9587 == TYPE_PACK_EXPANSION);
9588 new_specs = add_exception_specifier (new_specs,
9591 specs = TREE_CHAIN (specs);
9596 for (i = 0; i < len; ++i)
9599 spec = TREE_VEC_ELT (expanded_specs, i);
9601 spec = tsubst (TREE_VALUE (specs), args, complain, in_decl);
9602 if (spec == error_mark_node)
9604 new_specs = add_exception_specifier (new_specs, spec,
9608 specs = TREE_CHAIN (specs);
9614 /* Take the tree structure T and replace template parameters used
9615 therein with the argument vector ARGS. IN_DECL is an associated
9616 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
9617 Issue error and warning messages under control of COMPLAIN. Note
9618 that we must be relatively non-tolerant of extensions here, in
9619 order to preserve conformance; if we allow substitutions that
9620 should not be allowed, we may allow argument deductions that should
9621 not succeed, and therefore report ambiguous overload situations
9622 where there are none. In theory, we could allow the substitution,
9623 but indicate that it should have failed, and allow our caller to
9624 make sure that the right thing happens, but we don't try to do this
9627 This function is used for dealing with types, decls and the like;
9628 for expressions, use tsubst_expr or tsubst_copy. */
9631 tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl)
9635 if (t == NULL_TREE || t == error_mark_node
9636 || t == integer_type_node
9637 || t == void_type_node
9638 || t == char_type_node
9639 || t == unknown_type_node
9640 || TREE_CODE (t) == NAMESPACE_DECL)
9644 return tsubst_decl (t, args, complain);
9646 if (args == NULL_TREE)
9649 if (TREE_CODE (t) == IDENTIFIER_NODE)
9650 type = IDENTIFIER_TYPE_VALUE (t);
9652 type = TREE_TYPE (t);
9654 gcc_assert (type != unknown_type_node);
9656 /* Reuse typedefs. We need to do this to handle dependent attributes,
9657 such as attribute aligned. */
9660 && TYPE_NAME (t) != TYPE_MAIN_DECL (t))
9662 tree decl = TYPE_NAME (t);
9664 if (DECL_CLASS_SCOPE_P (decl)
9665 && CLASSTYPE_TEMPLATE_INFO (DECL_CONTEXT (decl))
9666 && uses_template_parms (DECL_CONTEXT (decl)))
9668 tree tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
9669 tree gen_args = tsubst (DECL_TI_ARGS (decl), args, complain, in_decl);
9670 r = retrieve_specialization (tmpl, gen_args, 0);
9672 else if (DECL_FUNCTION_SCOPE_P (decl)
9673 && DECL_TEMPLATE_INFO (DECL_CONTEXT (decl))
9674 && uses_template_parms (DECL_TI_ARGS (DECL_CONTEXT (decl))))
9675 r = retrieve_local_specialization (decl);
9677 /* The typedef is from a non-template context. */
9683 r = cp_build_qualified_type_real
9684 (r, cp_type_quals (t) | cp_type_quals (r),
9685 complain | tf_ignore_bad_quals);
9688 /* Else we must be instantiating the typedef, so fall through. */
9692 && TREE_CODE (t) != TYPENAME_TYPE
9693 && TREE_CODE (t) != IDENTIFIER_NODE
9694 && TREE_CODE (t) != FUNCTION_TYPE
9695 && TREE_CODE (t) != METHOD_TYPE)
9696 type = tsubst (type, args, complain, in_decl);
9697 if (type == error_mark_node)
9698 return error_mark_node;
9700 switch (TREE_CODE (t))
9705 return tsubst_aggr_type (t, args, complain, in_decl,
9706 /*entering_scope=*/0);
9709 case IDENTIFIER_NODE:
9721 if (t == integer_type_node)
9724 if (TREE_CODE (TYPE_MIN_VALUE (t)) == INTEGER_CST
9725 && TREE_CODE (TYPE_MAX_VALUE (t)) == INTEGER_CST)
9729 tree max, omax = TREE_OPERAND (TYPE_MAX_VALUE (t), 0);
9731 max = tsubst_expr (omax, args, complain, in_decl,
9732 /*integral_constant_expression_p=*/false);
9734 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
9736 if (TREE_CODE (max) == NOP_EXPR
9737 && TREE_SIDE_EFFECTS (omax)
9738 && !TREE_TYPE (max))
9739 TREE_TYPE (max) = TREE_TYPE (TREE_OPERAND (max, 0));
9741 max = fold_decl_constant_value (max);
9743 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
9744 with TREE_SIDE_EFFECTS that indicates this is not an integral
9745 constant expression. */
9746 if (processing_template_decl
9747 && TREE_SIDE_EFFECTS (omax) && TREE_CODE (omax) == NOP_EXPR)
9749 gcc_assert (TREE_CODE (max) == NOP_EXPR);
9750 TREE_SIDE_EFFECTS (max) = 1;
9753 if (TREE_CODE (max) != INTEGER_CST
9754 && !at_function_scope_p ()
9755 && !TREE_SIDE_EFFECTS (max)
9756 && !value_dependent_expression_p (max))
9758 if (complain & tf_error)
9759 error ("array bound is not an integer constant");
9760 return error_mark_node;
9765 Type deduction may fail for any of the following
9768 Attempting to create an array with a size that is
9769 zero or negative. */
9770 if (integer_zerop (max) && !(complain & tf_error))
9771 /* We must fail if performing argument deduction (as
9772 indicated by the state of complain), so that
9773 another substitution can be found. */
9774 return error_mark_node;
9775 else if (TREE_CODE (max) == INTEGER_CST
9776 && INT_CST_LT (max, integer_zero_node))
9778 if (complain & tf_error)
9779 error ("creating array with negative size (%qE)", max);
9781 return error_mark_node;
9784 return compute_array_index_type (NULL_TREE, max);
9787 case TEMPLATE_TYPE_PARM:
9788 case TEMPLATE_TEMPLATE_PARM:
9789 case BOUND_TEMPLATE_TEMPLATE_PARM:
9790 case TEMPLATE_PARM_INDEX:
9795 tree arg = NULL_TREE;
9799 gcc_assert (TREE_VEC_LENGTH (args) > 0);
9800 template_parm_level_and_index (t, &level, &idx);
9802 levels = TMPL_ARGS_DEPTH (args);
9803 if (level <= levels)
9805 arg = TMPL_ARG (args, level, idx);
9807 if (arg && TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
9808 /* See through ARGUMENT_PACK_SELECT arguments. */
9809 arg = ARGUMENT_PACK_SELECT_ARG (arg);
9812 if (arg == error_mark_node)
9813 return error_mark_node;
9814 else if (arg != NULL_TREE)
9816 if (ARGUMENT_PACK_P (arg))
9817 /* If ARG is an argument pack, we don't actually want to
9818 perform a substitution here, because substitutions
9819 for argument packs are only done
9820 element-by-element. We can get to this point when
9821 substituting the type of a non-type template
9822 parameter pack, when that type actually contains
9823 template parameter packs from an outer template, e.g.,
9825 template<typename... Types> struct A {
9826 template<Types... Values> struct B { };
9830 if (TREE_CODE (t) == TEMPLATE_TYPE_PARM)
9833 gcc_assert (TYPE_P (arg));
9835 /* cv-quals from the template are discarded when
9836 substituting in a function or reference type. */
9837 if (TREE_CODE (arg) == FUNCTION_TYPE
9838 || TREE_CODE (arg) == METHOD_TYPE
9839 || TREE_CODE (arg) == REFERENCE_TYPE)
9840 quals = cp_type_quals (arg);
9842 quals = cp_type_quals (arg) | cp_type_quals (t);
9844 return cp_build_qualified_type_real
9845 (arg, quals, complain | tf_ignore_bad_quals);
9847 else if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
9849 /* We are processing a type constructed from a
9850 template template parameter. */
9851 tree argvec = tsubst (TYPE_TI_ARGS (t),
9852 args, complain, in_decl);
9853 if (argvec == error_mark_node)
9854 return error_mark_node;
9856 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
9857 are resolving nested-types in the signature of a
9858 member function templates. Otherwise ARG is a
9859 TEMPLATE_DECL and is the real template to be
9861 if (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
9862 arg = TYPE_NAME (arg);
9864 r = lookup_template_class (arg,
9867 /*entering_scope=*/0,
9869 return cp_build_qualified_type_real
9870 (r, TYPE_QUALS (t), complain);
9873 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
9878 /* This can happen during the attempted tsubst'ing in
9879 unify. This means that we don't yet have any information
9880 about the template parameter in question. */
9883 /* If we get here, we must have been looking at a parm for a
9884 more deeply nested template. Make a new version of this
9885 template parameter, but with a lower level. */
9886 switch (TREE_CODE (t))
9888 case TEMPLATE_TYPE_PARM:
9889 case TEMPLATE_TEMPLATE_PARM:
9890 case BOUND_TEMPLATE_TEMPLATE_PARM:
9891 if (cp_type_quals (t))
9893 r = tsubst (TYPE_MAIN_VARIANT (t), args, complain, in_decl);
9894 r = cp_build_qualified_type_real
9895 (r, cp_type_quals (t),
9896 complain | (TREE_CODE (t) == TEMPLATE_TYPE_PARM
9897 ? tf_ignore_bad_quals : 0));
9902 TEMPLATE_TYPE_PARM_INDEX (r)
9903 = reduce_template_parm_level (TEMPLATE_TYPE_PARM_INDEX (t),
9904 r, levels, args, complain);
9905 TYPE_STUB_DECL (r) = TYPE_NAME (r) = TEMPLATE_TYPE_DECL (r);
9906 TYPE_MAIN_VARIANT (r) = r;
9907 TYPE_POINTER_TO (r) = NULL_TREE;
9908 TYPE_REFERENCE_TO (r) = NULL_TREE;
9910 if (TREE_CODE (r) == TEMPLATE_TEMPLATE_PARM)
9911 /* We have reduced the level of the template
9912 template parameter, but not the levels of its
9913 template parameters, so canonical_type_parameter
9914 will not be able to find the canonical template
9915 template parameter for this level. Thus, we
9916 require structural equality checking to compare
9917 TEMPLATE_TEMPLATE_PARMs. */
9918 SET_TYPE_STRUCTURAL_EQUALITY (r);
9919 else if (TYPE_STRUCTURAL_EQUALITY_P (t))
9920 SET_TYPE_STRUCTURAL_EQUALITY (r);
9922 TYPE_CANONICAL (r) = canonical_type_parameter (r);
9924 if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
9926 tree argvec = tsubst (TYPE_TI_ARGS (t), args,
9928 if (argvec == error_mark_node)
9929 return error_mark_node;
9931 TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (r)
9932 = build_template_info (TYPE_TI_TEMPLATE (t), argvec);
9937 case TEMPLATE_PARM_INDEX:
9938 r = reduce_template_parm_level (t, type, levels, args, complain);
9950 tree purpose, value, chain;
9952 if (t == void_list_node)
9955 purpose = TREE_PURPOSE (t);
9958 purpose = tsubst (purpose, args, complain, in_decl);
9959 if (purpose == error_mark_node)
9960 return error_mark_node;
9962 value = TREE_VALUE (t);
9965 value = tsubst (value, args, complain, in_decl);
9966 if (value == error_mark_node)
9967 return error_mark_node;
9969 chain = TREE_CHAIN (t);
9970 if (chain && chain != void_type_node)
9972 chain = tsubst (chain, args, complain, in_decl);
9973 if (chain == error_mark_node)
9974 return error_mark_node;
9976 if (purpose == TREE_PURPOSE (t)
9977 && value == TREE_VALUE (t)
9978 && chain == TREE_CHAIN (t))
9980 return hash_tree_cons (purpose, value, chain);
9984 /* We should never be tsubsting a binfo. */
9988 /* A vector of template arguments. */
9990 return tsubst_template_args (t, args, complain, in_decl);
9993 case REFERENCE_TYPE:
9995 enum tree_code code;
9997 if (type == TREE_TYPE (t) && TREE_CODE (type) != METHOD_TYPE)
10000 code = TREE_CODE (t);
10005 Type deduction may fail for any of the following
10008 -- Attempting to create a pointer to reference type.
10009 -- Attempting to create a reference to a reference type or
10010 a reference to void.
10012 Core issue 106 says that creating a reference to a reference
10013 during instantiation is no longer a cause for failure. We
10014 only enforce this check in strict C++98 mode. */
10015 if ((TREE_CODE (type) == REFERENCE_TYPE
10016 && (((cxx_dialect == cxx98) && flag_iso) || code != REFERENCE_TYPE))
10017 || (code == REFERENCE_TYPE && TREE_CODE (type) == VOID_TYPE))
10019 static location_t last_loc;
10021 /* We keep track of the last time we issued this error
10022 message to avoid spewing a ton of messages during a
10023 single bad template instantiation. */
10024 if (complain & tf_error
10025 && last_loc != input_location)
10027 if (TREE_CODE (type) == VOID_TYPE)
10028 error ("forming reference to void");
10030 error ("forming %s to reference type %qT",
10031 (code == POINTER_TYPE) ? "pointer" : "reference",
10033 last_loc = input_location;
10036 return error_mark_node;
10038 else if (code == POINTER_TYPE)
10040 r = build_pointer_type (type);
10041 if (TREE_CODE (type) == METHOD_TYPE)
10042 r = build_ptrmemfunc_type (r);
10044 else if (TREE_CODE (type) == REFERENCE_TYPE)
10045 /* In C++0x, during template argument substitution, when there is an
10046 attempt to create a reference to a reference type, reference
10047 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
10049 "If a template-argument for a template-parameter T names a type
10050 that is a reference to a type A, an attempt to create the type
10051 'lvalue reference to cv T' creates the type 'lvalue reference to
10052 A,' while an attempt to create the type type rvalue reference to
10053 cv T' creates the type T"
10055 r = cp_build_reference_type
10057 TYPE_REF_IS_RVALUE (t) && TYPE_REF_IS_RVALUE (type));
10059 r = cp_build_reference_type (type, TYPE_REF_IS_RVALUE (t));
10060 r = cp_build_qualified_type_real (r, TYPE_QUALS (t), complain);
10062 if (r != error_mark_node)
10063 /* Will this ever be needed for TYPE_..._TO values? */
10070 r = tsubst (TYPE_OFFSET_BASETYPE (t), args, complain, in_decl);
10071 if (r == error_mark_node || !MAYBE_CLASS_TYPE_P (r))
10075 Type deduction may fail for any of the following
10078 -- Attempting to create "pointer to member of T" when T
10079 is not a class type. */
10080 if (complain & tf_error)
10081 error ("creating pointer to member of non-class type %qT", r);
10082 return error_mark_node;
10084 if (TREE_CODE (type) == REFERENCE_TYPE)
10086 if (complain & tf_error)
10087 error ("creating pointer to member reference type %qT", type);
10088 return error_mark_node;
10090 if (TREE_CODE (type) == VOID_TYPE)
10092 if (complain & tf_error)
10093 error ("creating pointer to member of type void");
10094 return error_mark_node;
10096 gcc_assert (TREE_CODE (type) != METHOD_TYPE);
10097 if (TREE_CODE (type) == FUNCTION_TYPE)
10099 /* The type of the implicit object parameter gets its
10100 cv-qualifiers from the FUNCTION_TYPE. */
10102 tree method_type = build_memfn_type (type, r, cp_type_quals (type));
10103 memptr = build_ptrmemfunc_type (build_pointer_type (method_type));
10104 return cp_build_qualified_type_real (memptr, cp_type_quals (t),
10108 return cp_build_qualified_type_real (build_ptrmem_type (r, type),
10112 case FUNCTION_TYPE:
10117 fntype = tsubst_function_type (t, args, complain, in_decl);
10118 if (fntype == error_mark_node)
10119 return error_mark_node;
10121 /* Substitute the exception specification. */
10122 specs = tsubst_exception_specification (t, args, complain,
10124 if (specs == error_mark_node)
10125 return error_mark_node;
10127 fntype = build_exception_variant (fntype, specs);
10132 tree domain = tsubst (TYPE_DOMAIN (t), args, complain, in_decl);
10133 if (domain == error_mark_node)
10134 return error_mark_node;
10136 /* As an optimization, we avoid regenerating the array type if
10137 it will obviously be the same as T. */
10138 if (type == TREE_TYPE (t) && domain == TYPE_DOMAIN (t))
10141 /* These checks should match the ones in grokdeclarator.
10145 The deduction may fail for any of the following reasons:
10147 -- Attempting to create an array with an element type that
10148 is void, a function type, or a reference type, or [DR337]
10149 an abstract class type. */
10150 if (TREE_CODE (type) == VOID_TYPE
10151 || TREE_CODE (type) == FUNCTION_TYPE
10152 || TREE_CODE (type) == REFERENCE_TYPE)
10154 if (complain & tf_error)
10155 error ("creating array of %qT", type);
10156 return error_mark_node;
10158 if (CLASS_TYPE_P (type) && CLASSTYPE_PURE_VIRTUALS (type))
10160 if (complain & tf_error)
10161 error ("creating array of %qT, which is an abstract class type",
10163 return error_mark_node;
10166 r = build_cplus_array_type (type, domain);
10168 if (TYPE_USER_ALIGN (t))
10170 TYPE_ALIGN (r) = TYPE_ALIGN (t);
10171 TYPE_USER_ALIGN (r) = 1;
10180 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
10181 tree e2 = tsubst (TREE_OPERAND (t, 1), args, complain, in_decl);
10183 if (e1 == error_mark_node || e2 == error_mark_node)
10184 return error_mark_node;
10186 return fold_build2_loc (input_location,
10187 TREE_CODE (t), TREE_TYPE (t), e1, e2);
10193 tree e = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
10194 if (e == error_mark_node)
10195 return error_mark_node;
10197 return fold_build1_loc (input_location, TREE_CODE (t), TREE_TYPE (t), e);
10200 case TYPENAME_TYPE:
10202 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
10203 in_decl, /*entering_scope=*/1);
10204 tree f = tsubst_copy (TYPENAME_TYPE_FULLNAME (t), args,
10205 complain, in_decl);
10207 if (ctx == error_mark_node || f == error_mark_node)
10208 return error_mark_node;
10210 if (!MAYBE_CLASS_TYPE_P (ctx))
10212 if (complain & tf_error)
10213 error ("%qT is not a class, struct, or union type", ctx);
10214 return error_mark_node;
10216 else if (!uses_template_parms (ctx) && !TYPE_BEING_DEFINED (ctx))
10218 /* Normally, make_typename_type does not require that the CTX
10219 have complete type in order to allow things like:
10221 template <class T> struct S { typename S<T>::X Y; };
10223 But, such constructs have already been resolved by this
10224 point, so here CTX really should have complete type, unless
10225 it's a partial instantiation. */
10226 if (!(complain & tf_no_class_instantiations))
10227 ctx = complete_type (ctx);
10228 if (!COMPLETE_TYPE_P (ctx))
10230 if (complain & tf_error)
10231 cxx_incomplete_type_error (NULL_TREE, ctx);
10232 return error_mark_node;
10236 f = make_typename_type (ctx, f, typename_type,
10237 (complain & tf_error) | tf_keep_type_decl);
10238 if (f == error_mark_node)
10240 if (TREE_CODE (f) == TYPE_DECL)
10242 complain |= tf_ignore_bad_quals;
10246 if (TREE_CODE (f) != TYPENAME_TYPE)
10248 if (TYPENAME_IS_ENUM_P (t) && TREE_CODE (f) != ENUMERAL_TYPE)
10249 error ("%qT resolves to %qT, which is not an enumeration type",
10251 else if (TYPENAME_IS_CLASS_P (t) && !CLASS_TYPE_P (f))
10252 error ("%qT resolves to %qT, which is is not a class type",
10256 return cp_build_qualified_type_real
10257 (f, cp_type_quals (f) | cp_type_quals (t), complain);
10260 case UNBOUND_CLASS_TEMPLATE:
10262 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
10263 in_decl, /*entering_scope=*/1);
10264 tree name = TYPE_IDENTIFIER (t);
10265 tree parm_list = DECL_TEMPLATE_PARMS (TYPE_NAME (t));
10267 if (ctx == error_mark_node || name == error_mark_node)
10268 return error_mark_node;
10271 parm_list = tsubst_template_parms (parm_list, args, complain);
10272 return make_unbound_class_template (ctx, name, parm_list, complain);
10278 gcc_unreachable ();
10282 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
10283 tree e2 = tsubst_expr (TREE_OPERAND (t, 1), args, complain, in_decl,
10284 /*integral_constant_expression_p=*/false);
10285 if (e1 == error_mark_node || e2 == error_mark_node)
10286 return error_mark_node;
10288 return build_nt (ARRAY_REF, e1, e2, NULL_TREE, NULL_TREE);
10293 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
10294 tree e2 = tsubst (TREE_OPERAND (t, 1), args, complain, in_decl);
10295 if (e1 == error_mark_node || e2 == error_mark_node)
10296 return error_mark_node;
10298 return build_qualified_name (/*type=*/NULL_TREE,
10299 e1, e2, QUALIFIED_NAME_IS_TEMPLATE (t));
10306 ++cp_unevaluated_operand;
10307 ++c_inhibit_evaluation_warnings;
10309 type = tsubst_expr (TYPEOF_TYPE_EXPR (t), args,
10311 /*integral_constant_expression_p=*/false);
10313 --cp_unevaluated_operand;
10314 --c_inhibit_evaluation_warnings;
10316 type = finish_typeof (type);
10317 return cp_build_qualified_type_real (type,
10319 | cp_type_quals (type),
10323 case DECLTYPE_TYPE:
10327 ++cp_unevaluated_operand;
10328 ++c_inhibit_evaluation_warnings;
10330 type = tsubst_expr (DECLTYPE_TYPE_EXPR (t), args,
10332 /*integral_constant_expression_p=*/false);
10334 --cp_unevaluated_operand;
10335 --c_inhibit_evaluation_warnings;
10337 if (DECLTYPE_FOR_LAMBDA_CAPTURE (t))
10338 type = lambda_capture_field_type (type);
10339 else if (DECLTYPE_FOR_LAMBDA_RETURN (t))
10340 type = lambda_return_type (type);
10342 type = finish_decltype_type
10343 (type, DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t));
10344 return cp_build_qualified_type_real (type,
10346 | cp_type_quals (type),
10350 case TYPE_ARGUMENT_PACK:
10351 case NONTYPE_ARGUMENT_PACK:
10353 tree r = TYPE_P (t)
10354 ? cxx_make_type (TREE_CODE (t))
10355 : make_node (TREE_CODE (t));
10357 tsubst_template_args (ARGUMENT_PACK_ARGS (t),
10361 SET_ARGUMENT_PACK_ARGS (r, packed_out);
10363 /* For template nontype argument packs, also substitute into
10365 if (TREE_CODE (t) == NONTYPE_ARGUMENT_PACK)
10366 TREE_TYPE (r) = tsubst (TREE_TYPE (t), args, complain, in_decl);
10373 sorry ("use of %qs in template",
10374 tree_code_name [(int) TREE_CODE (t)]);
10375 return error_mark_node;
10379 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
10380 type of the expression on the left-hand side of the "." or "->"
10384 tsubst_baselink (tree baselink, tree object_type,
10385 tree args, tsubst_flags_t complain, tree in_decl)
10388 tree qualifying_scope;
10391 tree template_args = 0;
10392 bool template_id_p = false;
10394 /* A baselink indicates a function from a base class. Both the
10395 BASELINK_ACCESS_BINFO and the base class referenced may
10396 indicate bases of the template class, rather than the
10397 instantiated class. In addition, lookups that were not
10398 ambiguous before may be ambiguous now. Therefore, we perform
10399 the lookup again. */
10400 qualifying_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (baselink));
10401 qualifying_scope = tsubst (qualifying_scope, args,
10402 complain, in_decl);
10403 fns = BASELINK_FUNCTIONS (baselink);
10404 optype = tsubst (BASELINK_OPTYPE (baselink), args, complain, in_decl);
10405 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
10407 template_id_p = true;
10408 template_args = TREE_OPERAND (fns, 1);
10409 fns = TREE_OPERAND (fns, 0);
10411 template_args = tsubst_template_args (template_args, args,
10412 complain, in_decl);
10414 name = DECL_NAME (get_first_fn (fns));
10415 if (IDENTIFIER_TYPENAME_P (name))
10416 name = mangle_conv_op_name_for_type (optype);
10417 baselink = lookup_fnfields (qualifying_scope, name, /*protect=*/1);
10419 /* If lookup found a single function, mark it as used at this
10420 point. (If it lookup found multiple functions the one selected
10421 later by overload resolution will be marked as used at that
10423 if (BASELINK_P (baselink))
10424 fns = BASELINK_FUNCTIONS (baselink);
10425 if (!template_id_p && !really_overloaded_fn (fns))
10426 mark_used (OVL_CURRENT (fns));
10428 /* Add back the template arguments, if present. */
10429 if (BASELINK_P (baselink) && template_id_p)
10430 BASELINK_FUNCTIONS (baselink)
10431 = build_nt (TEMPLATE_ID_EXPR,
10432 BASELINK_FUNCTIONS (baselink),
10434 /* Update the conversion operator type. */
10435 BASELINK_OPTYPE (baselink) = optype;
10438 object_type = current_class_type;
10439 return adjust_result_of_qualified_name_lookup (baselink,
10444 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
10445 true if the qualified-id will be a postfix-expression in-and-of
10446 itself; false if more of the postfix-expression follows the
10447 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
10451 tsubst_qualified_id (tree qualified_id, tree args,
10452 tsubst_flags_t complain, tree in_decl,
10453 bool done, bool address_p)
10459 tree template_args;
10461 gcc_assert (TREE_CODE (qualified_id) == SCOPE_REF);
10463 /* Figure out what name to look up. */
10464 name = TREE_OPERAND (qualified_id, 1);
10465 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
10467 is_template = true;
10468 template_args = TREE_OPERAND (name, 1);
10470 template_args = tsubst_template_args (template_args, args,
10471 complain, in_decl);
10472 name = TREE_OPERAND (name, 0);
10476 is_template = false;
10477 template_args = NULL_TREE;
10480 /* Substitute into the qualifying scope. When there are no ARGS, we
10481 are just trying to simplify a non-dependent expression. In that
10482 case the qualifying scope may be dependent, and, in any case,
10483 substituting will not help. */
10484 scope = TREE_OPERAND (qualified_id, 0);
10487 scope = tsubst (scope, args, complain, in_decl);
10488 expr = tsubst_copy (name, args, complain, in_decl);
10493 if (dependent_type_p (scope))
10495 tree type = NULL_TREE;
10496 if (DECL_P (expr) && !dependent_scope_p (scope))
10497 type = TREE_TYPE (expr);
10498 return build_qualified_name (type, scope, expr,
10499 QUALIFIED_NAME_IS_TEMPLATE (qualified_id));
10502 if (!BASELINK_P (name) && !DECL_P (expr))
10504 if (TREE_CODE (expr) == BIT_NOT_EXPR)
10506 /* A BIT_NOT_EXPR is used to represent a destructor. */
10507 if (!check_dtor_name (scope, TREE_OPERAND (expr, 0)))
10509 error ("qualifying type %qT does not match destructor name ~%qT",
10510 scope, TREE_OPERAND (expr, 0));
10511 expr = error_mark_node;
10514 expr = lookup_qualified_name (scope, complete_dtor_identifier,
10515 /*is_type_p=*/0, false);
10518 expr = lookup_qualified_name (scope, expr, /*is_type_p=*/0, false);
10519 if (TREE_CODE (TREE_CODE (expr) == TEMPLATE_DECL
10520 ? DECL_TEMPLATE_RESULT (expr) : expr) == TYPE_DECL)
10522 if (complain & tf_error)
10524 error ("dependent-name %qE is parsed as a non-type, but "
10525 "instantiation yields a type", qualified_id);
10526 inform (input_location, "say %<typename %E%> if a type is meant", qualified_id);
10528 return error_mark_node;
10534 check_accessibility_of_qualified_id (expr, /*object_type=*/NULL_TREE,
10536 /* Remember that there was a reference to this entity. */
10540 if (expr == error_mark_node || TREE_CODE (expr) == TREE_LIST)
10542 if (complain & tf_error)
10543 qualified_name_lookup_error (scope,
10544 TREE_OPERAND (qualified_id, 1),
10545 expr, input_location);
10546 return error_mark_node;
10550 expr = lookup_template_function (expr, template_args);
10552 if (expr == error_mark_node && complain & tf_error)
10553 qualified_name_lookup_error (scope, TREE_OPERAND (qualified_id, 1),
10554 expr, input_location);
10555 else if (TYPE_P (scope))
10557 expr = (adjust_result_of_qualified_name_lookup
10558 (expr, scope, current_class_type));
10559 expr = (finish_qualified_id_expr
10560 (scope, expr, done, address_p,
10561 QUALIFIED_NAME_IS_TEMPLATE (qualified_id),
10562 /*template_arg_p=*/false));
10565 /* Expressions do not generally have reference type. */
10566 if (TREE_CODE (expr) != SCOPE_REF
10567 /* However, if we're about to form a pointer-to-member, we just
10568 want the referenced member referenced. */
10569 && TREE_CODE (expr) != OFFSET_REF)
10570 expr = convert_from_reference (expr);
10575 /* Like tsubst, but deals with expressions. This function just replaces
10576 template parms; to finish processing the resultant expression, use
10580 tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl)
10582 enum tree_code code;
10585 if (t == NULL_TREE || t == error_mark_node || args == NULL_TREE)
10588 code = TREE_CODE (t);
10593 r = retrieve_local_specialization (t);
10598 /* This can happen for a parameter name used later in a function
10599 declaration (such as in a late-specified return type). Just
10600 make a dummy decl, since it's only used for its type. */
10601 gcc_assert (cp_unevaluated_operand != 0);
10602 /* We copy T because want to tsubst the PARM_DECL only,
10603 not the following PARM_DECLs that are chained to T. */
10605 r = tsubst_decl (c, args, complain);
10606 /* Give it the template pattern as its context; its true context
10607 hasn't been instantiated yet and this is good enough for
10609 DECL_CONTEXT (r) = DECL_CONTEXT (t);
10612 if (TREE_CODE (r) == ARGUMENT_PACK_SELECT)
10613 r = ARGUMENT_PACK_SELECT_ARG (r);
10622 if (DECL_TEMPLATE_PARM_P (t))
10623 return tsubst_copy (DECL_INITIAL (t), args, complain, in_decl);
10624 /* There is no need to substitute into namespace-scope
10626 if (DECL_NAMESPACE_SCOPE_P (t))
10628 /* If ARGS is NULL, then T is known to be non-dependent. */
10629 if (args == NULL_TREE)
10630 return integral_constant_value (t);
10632 /* Unfortunately, we cannot just call lookup_name here.
10635 template <int I> int f() {
10637 struct S { void g() { E e = a; } };
10640 When we instantiate f<7>::S::g(), say, lookup_name is not
10641 clever enough to find f<7>::a. */
10643 = tsubst_aggr_type (TREE_TYPE (t), args, complain, in_decl,
10644 /*entering_scope=*/0);
10646 for (v = TYPE_VALUES (enum_type);
10648 v = TREE_CHAIN (v))
10649 if (TREE_PURPOSE (v) == DECL_NAME (t))
10650 return TREE_VALUE (v);
10652 /* We didn't find the name. That should never happen; if
10653 name-lookup found it during preliminary parsing, we
10654 should find it again here during instantiation. */
10655 gcc_unreachable ();
10660 if (DECL_CONTEXT (t))
10664 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args, complain, in_decl,
10665 /*entering_scope=*/1);
10666 if (ctx != DECL_CONTEXT (t))
10668 tree r = lookup_field (ctx, DECL_NAME (t), 0, false);
10671 if (complain & tf_error)
10672 error ("using invalid field %qD", t);
10673 return error_mark_node;
10682 case FUNCTION_DECL:
10683 if ((DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t))
10684 || local_variable_p (t))
10685 t = tsubst (t, args, complain, in_decl);
10690 return tsubst_baselink (t, current_class_type, args, complain, in_decl);
10692 case TEMPLATE_DECL:
10693 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
10694 return tsubst (TREE_TYPE (DECL_TEMPLATE_RESULT (t)),
10695 args, complain, in_decl);
10696 else if (DECL_FUNCTION_TEMPLATE_P (t) && DECL_MEMBER_TEMPLATE_P (t))
10697 return tsubst (t, args, complain, in_decl);
10698 else if (DECL_CLASS_SCOPE_P (t)
10699 && uses_template_parms (DECL_CONTEXT (t)))
10701 /* Template template argument like the following example need
10704 template <template <class> class TT> struct C {};
10705 template <class T> struct D {
10706 template <class U> struct E {};
10711 We are processing the template argument `E' in #1 for
10712 the template instantiation #2. Originally, `E' is a
10713 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
10714 have to substitute this with one having context `D<int>'. */
10716 tree context = tsubst (DECL_CONTEXT (t), args, complain, in_decl);
10717 return lookup_field (context, DECL_NAME(t), 0, false);
10720 /* Ordinary template template argument. */
10724 case REINTERPRET_CAST_EXPR:
10725 case CONST_CAST_EXPR:
10726 case STATIC_CAST_EXPR:
10727 case DYNAMIC_CAST_EXPR:
10730 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
10731 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
10734 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
10736 /* We only want to compute the number of arguments. */
10737 tree expanded = tsubst_pack_expansion (TREE_OPERAND (t, 0), args,
10738 complain, in_decl);
10741 if (TREE_CODE (expanded) == TREE_VEC)
10742 len = TREE_VEC_LENGTH (expanded);
10744 if (expanded == error_mark_node)
10745 return error_mark_node;
10746 else if (PACK_EXPANSION_P (expanded)
10747 || (TREE_CODE (expanded) == TREE_VEC
10749 && PACK_EXPANSION_P (TREE_VEC_ELT (expanded, len-1))))
10751 if (TREE_CODE (expanded) == TREE_VEC)
10752 expanded = TREE_VEC_ELT (expanded, len - 1);
10754 if (TYPE_P (expanded))
10755 return cxx_sizeof_or_alignof_type (expanded, SIZEOF_EXPR,
10756 complain & tf_error);
10758 return cxx_sizeof_or_alignof_expr (expanded, SIZEOF_EXPR,
10759 complain & tf_error);
10762 return build_int_cst (size_type_node, len);
10768 case TRUTH_NOT_EXPR:
10771 case UNARY_PLUS_EXPR: /* Unary + */
10776 case REALPART_EXPR:
10777 case IMAGPART_EXPR:
10779 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
10780 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
10782 case COMPONENT_REF:
10787 object = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
10788 name = TREE_OPERAND (t, 1);
10789 if (TREE_CODE (name) == BIT_NOT_EXPR)
10791 name = tsubst_copy (TREE_OPERAND (name, 0), args,
10792 complain, in_decl);
10793 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
10795 else if (TREE_CODE (name) == SCOPE_REF
10796 && TREE_CODE (TREE_OPERAND (name, 1)) == BIT_NOT_EXPR)
10798 tree base = tsubst_copy (TREE_OPERAND (name, 0), args,
10799 complain, in_decl);
10800 name = TREE_OPERAND (name, 1);
10801 name = tsubst_copy (TREE_OPERAND (name, 0), args,
10802 complain, in_decl);
10803 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
10804 name = build_qualified_name (/*type=*/NULL_TREE,
10806 /*template_p=*/false);
10808 else if (TREE_CODE (name) == BASELINK)
10809 name = tsubst_baselink (name,
10810 non_reference (TREE_TYPE (object)),
10814 name = tsubst_copy (name, args, complain, in_decl);
10815 return build_nt (COMPONENT_REF, object, name, NULL_TREE);
10821 case TRUNC_DIV_EXPR:
10822 case CEIL_DIV_EXPR:
10823 case FLOOR_DIV_EXPR:
10824 case ROUND_DIV_EXPR:
10825 case EXACT_DIV_EXPR:
10829 case TRUNC_MOD_EXPR:
10830 case FLOOR_MOD_EXPR:
10831 case TRUTH_ANDIF_EXPR:
10832 case TRUTH_ORIF_EXPR:
10833 case TRUTH_AND_EXPR:
10834 case TRUTH_OR_EXPR:
10847 case COMPOUND_EXPR:
10850 case PREDECREMENT_EXPR:
10851 case PREINCREMENT_EXPR:
10852 case POSTDECREMENT_EXPR:
10853 case POSTINCREMENT_EXPR:
10855 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
10856 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
10859 return build_qualified_name (/*type=*/NULL_TREE,
10860 tsubst_copy (TREE_OPERAND (t, 0),
10861 args, complain, in_decl),
10862 tsubst_copy (TREE_OPERAND (t, 1),
10863 args, complain, in_decl),
10864 QUALIFIED_NAME_IS_TEMPLATE (t));
10869 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
10870 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
10871 NULL_TREE, NULL_TREE);
10875 int n = VL_EXP_OPERAND_LENGTH (t);
10876 tree result = build_vl_exp (CALL_EXPR, n);
10878 for (i = 0; i < n; i++)
10879 TREE_OPERAND (t, i) = tsubst_copy (TREE_OPERAND (t, i), args,
10880 complain, in_decl);
10886 case PSEUDO_DTOR_EXPR:
10889 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
10890 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
10891 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
10892 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
10899 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
10900 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
10901 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
10902 NEW_EXPR_USE_GLOBAL (r) = NEW_EXPR_USE_GLOBAL (t);
10909 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
10910 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
10911 DELETE_EXPR_USE_GLOBAL (r) = DELETE_EXPR_USE_GLOBAL (t);
10912 DELETE_EXPR_USE_VEC (r) = DELETE_EXPR_USE_VEC (t);
10916 case TEMPLATE_ID_EXPR:
10918 /* Substituted template arguments */
10919 tree fn = TREE_OPERAND (t, 0);
10920 tree targs = TREE_OPERAND (t, 1);
10922 fn = tsubst_copy (fn, args, complain, in_decl);
10924 targs = tsubst_template_args (targs, args, complain, in_decl);
10926 return lookup_template_function (fn, targs);
10931 tree purpose, value, chain;
10933 if (t == void_list_node)
10936 purpose = TREE_PURPOSE (t);
10938 purpose = tsubst_copy (purpose, args, complain, in_decl);
10939 value = TREE_VALUE (t);
10941 value = tsubst_copy (value, args, complain, in_decl);
10942 chain = TREE_CHAIN (t);
10943 if (chain && chain != void_type_node)
10944 chain = tsubst_copy (chain, args, complain, in_decl);
10945 if (purpose == TREE_PURPOSE (t)
10946 && value == TREE_VALUE (t)
10947 && chain == TREE_CHAIN (t))
10949 return tree_cons (purpose, value, chain);
10954 case ENUMERAL_TYPE:
10956 case TEMPLATE_TYPE_PARM:
10957 case TEMPLATE_TEMPLATE_PARM:
10958 case BOUND_TEMPLATE_TEMPLATE_PARM:
10959 case TEMPLATE_PARM_INDEX:
10961 case REFERENCE_TYPE:
10963 case FUNCTION_TYPE:
10966 case TYPENAME_TYPE:
10967 case UNBOUND_CLASS_TEMPLATE:
10969 case DECLTYPE_TYPE:
10971 return tsubst (t, args, complain, in_decl);
10973 case IDENTIFIER_NODE:
10974 if (IDENTIFIER_TYPENAME_P (t))
10976 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
10977 return mangle_conv_op_name_for_type (new_type);
10983 /* This is handled by tsubst_copy_and_build. */
10984 gcc_unreachable ();
10987 return build_x_va_arg (tsubst_copy (TREE_OPERAND (t, 0), args, complain,
10989 tsubst (TREE_TYPE (t), args, complain, in_decl));
10991 case CLEANUP_POINT_EXPR:
10992 /* We shouldn't have built any of these during initial template
10993 generation. Instead, they should be built during instantiation
10994 in response to the saved STMT_IS_FULL_EXPR_P setting. */
10995 gcc_unreachable ();
10998 mark_used (TREE_OPERAND (t, 1));
11001 case EXPR_PACK_EXPANSION:
11002 error ("invalid use of pack expansion expression");
11003 return error_mark_node;
11005 case NONTYPE_ARGUMENT_PACK:
11006 error ("use %<...%> to expand argument pack");
11007 return error_mark_node;
11014 /* Like tsubst_copy, but specifically for OpenMP clauses. */
11017 tsubst_omp_clauses (tree clauses, tree args, tsubst_flags_t complain,
11020 tree new_clauses = NULL, nc, oc;
11022 for (oc = clauses; oc ; oc = OMP_CLAUSE_CHAIN (oc))
11024 nc = copy_node (oc);
11025 OMP_CLAUSE_CHAIN (nc) = new_clauses;
11028 switch (OMP_CLAUSE_CODE (nc))
11030 case OMP_CLAUSE_LASTPRIVATE:
11031 if (OMP_CLAUSE_LASTPRIVATE_STMT (oc))
11033 OMP_CLAUSE_LASTPRIVATE_STMT (nc) = push_stmt_list ();
11034 tsubst_expr (OMP_CLAUSE_LASTPRIVATE_STMT (oc), args, complain,
11035 in_decl, /*integral_constant_expression_p=*/false);
11036 OMP_CLAUSE_LASTPRIVATE_STMT (nc)
11037 = pop_stmt_list (OMP_CLAUSE_LASTPRIVATE_STMT (nc));
11040 case OMP_CLAUSE_PRIVATE:
11041 case OMP_CLAUSE_SHARED:
11042 case OMP_CLAUSE_FIRSTPRIVATE:
11043 case OMP_CLAUSE_REDUCTION:
11044 case OMP_CLAUSE_COPYIN:
11045 case OMP_CLAUSE_COPYPRIVATE:
11046 case OMP_CLAUSE_IF:
11047 case OMP_CLAUSE_NUM_THREADS:
11048 case OMP_CLAUSE_SCHEDULE:
11049 case OMP_CLAUSE_COLLAPSE:
11050 OMP_CLAUSE_OPERAND (nc, 0)
11051 = tsubst_expr (OMP_CLAUSE_OPERAND (oc, 0), args, complain,
11052 in_decl, /*integral_constant_expression_p=*/false);
11054 case OMP_CLAUSE_NOWAIT:
11055 case OMP_CLAUSE_ORDERED:
11056 case OMP_CLAUSE_DEFAULT:
11057 case OMP_CLAUSE_UNTIED:
11060 gcc_unreachable ();
11064 return finish_omp_clauses (nreverse (new_clauses));
11067 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
11070 tsubst_copy_asm_operands (tree t, tree args, tsubst_flags_t complain,
11073 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
11075 tree purpose, value, chain;
11080 if (TREE_CODE (t) != TREE_LIST)
11081 return tsubst_copy_and_build (t, args, complain, in_decl,
11082 /*function_p=*/false,
11083 /*integral_constant_expression_p=*/false);
11085 if (t == void_list_node)
11088 purpose = TREE_PURPOSE (t);
11090 purpose = RECUR (purpose);
11091 value = TREE_VALUE (t);
11092 if (value && TREE_CODE (value) != LABEL_DECL)
11093 value = RECUR (value);
11094 chain = TREE_CHAIN (t);
11095 if (chain && chain != void_type_node)
11096 chain = RECUR (chain);
11097 return tree_cons (purpose, value, chain);
11101 /* Substitute one OMP_FOR iterator. */
11104 tsubst_omp_for_iterator (tree t, int i, tree declv, tree initv,
11105 tree condv, tree incrv, tree *clauses,
11106 tree args, tsubst_flags_t complain, tree in_decl,
11107 bool integral_constant_expression_p)
11109 #define RECUR(NODE) \
11110 tsubst_expr ((NODE), args, complain, in_decl, \
11111 integral_constant_expression_p)
11112 tree decl, init, cond, incr, auto_node;
11114 init = TREE_VEC_ELT (OMP_FOR_INIT (t), i);
11115 gcc_assert (TREE_CODE (init) == MODIFY_EXPR);
11116 decl = RECUR (TREE_OPERAND (init, 0));
11117 init = TREE_OPERAND (init, 1);
11118 auto_node = type_uses_auto (TREE_TYPE (decl));
11119 if (auto_node && init)
11121 tree init_expr = init;
11122 if (TREE_CODE (init_expr) == DECL_EXPR)
11123 init_expr = DECL_INITIAL (DECL_EXPR_DECL (init_expr));
11124 init_expr = RECUR (init_expr);
11126 = do_auto_deduction (TREE_TYPE (decl), init_expr, auto_node);
11128 gcc_assert (!type_dependent_expression_p (decl));
11130 if (!CLASS_TYPE_P (TREE_TYPE (decl)))
11132 cond = RECUR (TREE_VEC_ELT (OMP_FOR_COND (t), i));
11133 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
11134 if (TREE_CODE (incr) == MODIFY_EXPR)
11135 incr = build_x_modify_expr (RECUR (TREE_OPERAND (incr, 0)), NOP_EXPR,
11136 RECUR (TREE_OPERAND (incr, 1)),
11139 incr = RECUR (incr);
11140 TREE_VEC_ELT (declv, i) = decl;
11141 TREE_VEC_ELT (initv, i) = init;
11142 TREE_VEC_ELT (condv, i) = cond;
11143 TREE_VEC_ELT (incrv, i) = incr;
11147 if (init && TREE_CODE (init) != DECL_EXPR)
11150 for (c = *clauses; c ; c = OMP_CLAUSE_CHAIN (c))
11152 if ((OMP_CLAUSE_CODE (c) == OMP_CLAUSE_PRIVATE
11153 || OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LASTPRIVATE)
11154 && OMP_CLAUSE_DECL (c) == decl)
11156 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_FIRSTPRIVATE
11157 && OMP_CLAUSE_DECL (c) == decl)
11158 error ("iteration variable %qD should not be firstprivate", decl);
11159 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_REDUCTION
11160 && OMP_CLAUSE_DECL (c) == decl)
11161 error ("iteration variable %qD should not be reduction", decl);
11165 c = build_omp_clause (input_location, OMP_CLAUSE_PRIVATE);
11166 OMP_CLAUSE_DECL (c) = decl;
11167 c = finish_omp_clauses (c);
11170 OMP_CLAUSE_CHAIN (c) = *clauses;
11175 cond = TREE_VEC_ELT (OMP_FOR_COND (t), i);
11176 if (COMPARISON_CLASS_P (cond))
11177 cond = build2 (TREE_CODE (cond), boolean_type_node,
11178 RECUR (TREE_OPERAND (cond, 0)),
11179 RECUR (TREE_OPERAND (cond, 1)));
11181 cond = RECUR (cond);
11182 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
11183 switch (TREE_CODE (incr))
11185 case PREINCREMENT_EXPR:
11186 case PREDECREMENT_EXPR:
11187 case POSTINCREMENT_EXPR:
11188 case POSTDECREMENT_EXPR:
11189 incr = build2 (TREE_CODE (incr), TREE_TYPE (decl),
11190 RECUR (TREE_OPERAND (incr, 0)), NULL_TREE);
11193 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
11194 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
11196 tree rhs = TREE_OPERAND (incr, 1);
11197 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
11198 RECUR (TREE_OPERAND (incr, 0)),
11199 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
11200 RECUR (TREE_OPERAND (rhs, 0)),
11201 RECUR (TREE_OPERAND (rhs, 1))));
11204 incr = RECUR (incr);
11207 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
11208 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
11210 tree lhs = RECUR (TREE_OPERAND (incr, 0));
11211 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl), lhs,
11212 build2 (TREE_CODE (TREE_OPERAND (incr, 1)),
11213 TREE_TYPE (decl), lhs,
11214 RECUR (TREE_OPERAND (incr, 2))));
11216 else if (TREE_CODE (TREE_OPERAND (incr, 1)) == NOP_EXPR
11217 && (TREE_CODE (TREE_OPERAND (incr, 2)) == PLUS_EXPR
11218 || (TREE_CODE (TREE_OPERAND (incr, 2)) == MINUS_EXPR)))
11220 tree rhs = TREE_OPERAND (incr, 2);
11221 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
11222 RECUR (TREE_OPERAND (incr, 0)),
11223 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
11224 RECUR (TREE_OPERAND (rhs, 0)),
11225 RECUR (TREE_OPERAND (rhs, 1))));
11228 incr = RECUR (incr);
11231 incr = RECUR (incr);
11235 TREE_VEC_ELT (declv, i) = decl;
11236 TREE_VEC_ELT (initv, i) = init;
11237 TREE_VEC_ELT (condv, i) = cond;
11238 TREE_VEC_ELT (incrv, i) = incr;
11242 /* Like tsubst_copy for expressions, etc. but also does semantic
11246 tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl,
11247 bool integral_constant_expression_p)
11249 #define RECUR(NODE) \
11250 tsubst_expr ((NODE), args, complain, in_decl, \
11251 integral_constant_expression_p)
11255 if (t == NULL_TREE || t == error_mark_node)
11258 if (EXPR_HAS_LOCATION (t))
11259 input_location = EXPR_LOCATION (t);
11260 if (STATEMENT_CODE_P (TREE_CODE (t)))
11261 current_stmt_tree ()->stmts_are_full_exprs_p = STMT_IS_FULL_EXPR_P (t);
11263 switch (TREE_CODE (t))
11265 case STATEMENT_LIST:
11267 tree_stmt_iterator i;
11268 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
11269 RECUR (tsi_stmt (i));
11273 case CTOR_INITIALIZER:
11274 finish_mem_initializers (tsubst_initializer_list
11275 (TREE_OPERAND (t, 0), args));
11279 finish_return_stmt (RECUR (TREE_OPERAND (t, 0)));
11283 tmp = RECUR (EXPR_STMT_EXPR (t));
11284 if (EXPR_STMT_STMT_EXPR_RESULT (t))
11285 finish_stmt_expr_expr (tmp, cur_stmt_expr);
11287 finish_expr_stmt (tmp);
11291 do_using_directive (RECUR (USING_STMT_NAMESPACE (t)));
11299 decl = DECL_EXPR_DECL (t);
11300 if (TREE_CODE (decl) == LABEL_DECL)
11301 finish_label_decl (DECL_NAME (decl));
11302 else if (TREE_CODE (decl) == USING_DECL)
11304 tree scope = USING_DECL_SCOPE (decl);
11305 tree name = DECL_NAME (decl);
11308 scope = RECUR (scope);
11309 decl = lookup_qualified_name (scope, name,
11310 /*is_type_p=*/false,
11311 /*complain=*/false);
11312 if (decl == error_mark_node || TREE_CODE (decl) == TREE_LIST)
11313 qualified_name_lookup_error (scope, name, decl, input_location);
11315 do_local_using_decl (decl, scope, name);
11319 init = DECL_INITIAL (decl);
11320 decl = tsubst (decl, args, complain, in_decl);
11321 if (decl != error_mark_node)
11323 /* By marking the declaration as instantiated, we avoid
11324 trying to instantiate it. Since instantiate_decl can't
11325 handle local variables, and since we've already done
11326 all that needs to be done, that's the right thing to
11328 if (TREE_CODE (decl) == VAR_DECL)
11329 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
11330 if (TREE_CODE (decl) == VAR_DECL
11331 && ANON_AGGR_TYPE_P (TREE_TYPE (decl)))
11332 /* Anonymous aggregates are a special case. */
11333 finish_anon_union (decl);
11336 maybe_push_decl (decl);
11337 if (TREE_CODE (decl) == VAR_DECL
11338 && DECL_PRETTY_FUNCTION_P (decl))
11340 /* For __PRETTY_FUNCTION__ we have to adjust the
11342 const char *const name
11343 = cxx_printable_name (current_function_decl, 2);
11344 init = cp_fname_init (name, &TREE_TYPE (decl));
11348 tree t = RECUR (init);
11351 /* If we had an initializer but it
11352 instantiated to nothing,
11353 value-initialize the object. This will
11354 only occur when the initializer was a
11355 pack expansion where the parameter packs
11356 used in that expansion were of length
11358 init = build_value_init (TREE_TYPE (decl));
11363 cp_finish_decl (decl, init, false, NULL_TREE, 0);
11368 /* A DECL_EXPR can also be used as an expression, in the condition
11369 clause of an if/for/while construct. */
11374 stmt = begin_for_stmt ();
11375 RECUR (FOR_INIT_STMT (t));
11376 finish_for_init_stmt (stmt);
11377 tmp = RECUR (FOR_COND (t));
11378 finish_for_cond (tmp, stmt);
11379 tmp = RECUR (FOR_EXPR (t));
11380 finish_for_expr (tmp, stmt);
11381 RECUR (FOR_BODY (t));
11382 finish_for_stmt (stmt);
11386 stmt = begin_while_stmt ();
11387 tmp = RECUR (WHILE_COND (t));
11388 finish_while_stmt_cond (tmp, stmt);
11389 RECUR (WHILE_BODY (t));
11390 finish_while_stmt (stmt);
11394 stmt = begin_do_stmt ();
11395 RECUR (DO_BODY (t));
11396 finish_do_body (stmt);
11397 tmp = RECUR (DO_COND (t));
11398 finish_do_stmt (tmp, stmt);
11402 stmt = begin_if_stmt ();
11403 tmp = RECUR (IF_COND (t));
11404 finish_if_stmt_cond (tmp, stmt);
11405 RECUR (THEN_CLAUSE (t));
11406 finish_then_clause (stmt);
11408 if (ELSE_CLAUSE (t))
11410 begin_else_clause (stmt);
11411 RECUR (ELSE_CLAUSE (t));
11412 finish_else_clause (stmt);
11415 finish_if_stmt (stmt);
11419 if (BIND_EXPR_BODY_BLOCK (t))
11420 stmt = begin_function_body ();
11422 stmt = begin_compound_stmt (BIND_EXPR_TRY_BLOCK (t)
11423 ? BCS_TRY_BLOCK : 0);
11425 RECUR (BIND_EXPR_BODY (t));
11427 if (BIND_EXPR_BODY_BLOCK (t))
11428 finish_function_body (stmt);
11430 finish_compound_stmt (stmt);
11434 finish_break_stmt ();
11437 case CONTINUE_STMT:
11438 finish_continue_stmt ();
11442 stmt = begin_switch_stmt ();
11443 tmp = RECUR (SWITCH_STMT_COND (t));
11444 finish_switch_cond (tmp, stmt);
11445 RECUR (SWITCH_STMT_BODY (t));
11446 finish_switch_stmt (stmt);
11449 case CASE_LABEL_EXPR:
11450 finish_case_label (EXPR_LOCATION (t),
11451 RECUR (CASE_LOW (t)),
11452 RECUR (CASE_HIGH (t)));
11457 tree decl = LABEL_EXPR_LABEL (t);
11460 label = finish_label_stmt (DECL_NAME (decl));
11461 if (DECL_ATTRIBUTES (decl) != NULL_TREE)
11462 cplus_decl_attributes (&label, DECL_ATTRIBUTES (decl), 0);
11467 tmp = GOTO_DESTINATION (t);
11468 if (TREE_CODE (tmp) != LABEL_DECL)
11469 /* Computed goto's must be tsubst'd into. On the other hand,
11470 non-computed gotos must not be; the identifier in question
11471 will have no binding. */
11474 tmp = DECL_NAME (tmp);
11475 finish_goto_stmt (tmp);
11479 tmp = finish_asm_stmt
11480 (ASM_VOLATILE_P (t),
11481 RECUR (ASM_STRING (t)),
11482 tsubst_copy_asm_operands (ASM_OUTPUTS (t), args, complain, in_decl),
11483 tsubst_copy_asm_operands (ASM_INPUTS (t), args, complain, in_decl),
11484 tsubst_copy_asm_operands (ASM_CLOBBERS (t), args, complain, in_decl),
11485 tsubst_copy_asm_operands (ASM_LABELS (t), args, complain, in_decl));
11487 tree asm_expr = tmp;
11488 if (TREE_CODE (asm_expr) == CLEANUP_POINT_EXPR)
11489 asm_expr = TREE_OPERAND (asm_expr, 0);
11490 ASM_INPUT_P (asm_expr) = ASM_INPUT_P (t);
11497 stmt = begin_try_block ();
11498 RECUR (TRY_STMTS (t));
11499 finish_cleanup_try_block (stmt);
11500 finish_cleanup (RECUR (TRY_HANDLERS (t)), stmt);
11504 tree compound_stmt = NULL_TREE;
11506 if (FN_TRY_BLOCK_P (t))
11507 stmt = begin_function_try_block (&compound_stmt);
11509 stmt = begin_try_block ();
11511 RECUR (TRY_STMTS (t));
11513 if (FN_TRY_BLOCK_P (t))
11514 finish_function_try_block (stmt);
11516 finish_try_block (stmt);
11518 RECUR (TRY_HANDLERS (t));
11519 if (FN_TRY_BLOCK_P (t))
11520 finish_function_handler_sequence (stmt, compound_stmt);
11522 finish_handler_sequence (stmt);
11528 tree decl = HANDLER_PARMS (t);
11532 decl = tsubst (decl, args, complain, in_decl);
11533 /* Prevent instantiate_decl from trying to instantiate
11534 this variable. We've already done all that needs to be
11536 if (decl != error_mark_node)
11537 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
11539 stmt = begin_handler ();
11540 finish_handler_parms (decl, stmt);
11541 RECUR (HANDLER_BODY (t));
11542 finish_handler (stmt);
11547 tsubst (TREE_TYPE (t), args, complain, NULL_TREE);
11550 case STATIC_ASSERT:
11553 tsubst_expr (STATIC_ASSERT_CONDITION (t),
11556 /*integral_constant_expression_p=*/true);
11557 finish_static_assert (condition,
11558 STATIC_ASSERT_MESSAGE (t),
11559 STATIC_ASSERT_SOURCE_LOCATION (t),
11560 /*member_p=*/false);
11565 tmp = tsubst_omp_clauses (OMP_PARALLEL_CLAUSES (t),
11566 args, complain, in_decl);
11567 stmt = begin_omp_parallel ();
11568 RECUR (OMP_PARALLEL_BODY (t));
11569 OMP_PARALLEL_COMBINED (finish_omp_parallel (tmp, stmt))
11570 = OMP_PARALLEL_COMBINED (t);
11574 tmp = tsubst_omp_clauses (OMP_TASK_CLAUSES (t),
11575 args, complain, in_decl);
11576 stmt = begin_omp_task ();
11577 RECUR (OMP_TASK_BODY (t));
11578 finish_omp_task (tmp, stmt);
11583 tree clauses, body, pre_body;
11584 tree declv, initv, condv, incrv;
11587 clauses = tsubst_omp_clauses (OMP_FOR_CLAUSES (t),
11588 args, complain, in_decl);
11589 declv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
11590 initv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
11591 condv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
11592 incrv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
11594 for (i = 0; i < TREE_VEC_LENGTH (OMP_FOR_INIT (t)); i++)
11595 tsubst_omp_for_iterator (t, i, declv, initv, condv, incrv,
11596 &clauses, args, complain, in_decl,
11597 integral_constant_expression_p);
11599 stmt = begin_omp_structured_block ();
11601 for (i = 0; i < TREE_VEC_LENGTH (initv); i++)
11602 if (TREE_VEC_ELT (initv, i) == NULL
11603 || TREE_CODE (TREE_VEC_ELT (initv, i)) != DECL_EXPR)
11604 TREE_VEC_ELT (initv, i) = RECUR (TREE_VEC_ELT (initv, i));
11605 else if (CLASS_TYPE_P (TREE_TYPE (TREE_VEC_ELT (initv, i))))
11607 tree init = RECUR (TREE_VEC_ELT (initv, i));
11608 gcc_assert (init == TREE_VEC_ELT (declv, i));
11609 TREE_VEC_ELT (initv, i) = NULL_TREE;
11613 tree decl_expr = TREE_VEC_ELT (initv, i);
11614 tree init = DECL_INITIAL (DECL_EXPR_DECL (decl_expr));
11615 gcc_assert (init != NULL);
11616 TREE_VEC_ELT (initv, i) = RECUR (init);
11617 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = NULL;
11619 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = init;
11622 pre_body = push_stmt_list ();
11623 RECUR (OMP_FOR_PRE_BODY (t));
11624 pre_body = pop_stmt_list (pre_body);
11626 body = push_stmt_list ();
11627 RECUR (OMP_FOR_BODY (t));
11628 body = pop_stmt_list (body);
11630 t = finish_omp_for (EXPR_LOCATION (t), declv, initv, condv, incrv,
11631 body, pre_body, clauses);
11633 add_stmt (finish_omp_structured_block (stmt));
11639 tmp = tsubst_omp_clauses (OMP_CLAUSES (t), args, complain, in_decl);
11640 stmt = push_stmt_list ();
11641 RECUR (OMP_BODY (t));
11642 stmt = pop_stmt_list (stmt);
11645 OMP_BODY (t) = stmt;
11646 OMP_CLAUSES (t) = tmp;
11654 stmt = push_stmt_list ();
11655 RECUR (OMP_BODY (t));
11656 stmt = pop_stmt_list (stmt);
11659 OMP_BODY (t) = stmt;
11664 gcc_assert (OMP_ATOMIC_DEPENDENT_P (t));
11666 tree op1 = TREE_OPERAND (t, 1);
11667 tree lhs = RECUR (TREE_OPERAND (op1, 0));
11668 tree rhs = RECUR (TREE_OPERAND (op1, 1));
11669 finish_omp_atomic (TREE_CODE (op1), lhs, rhs);
11673 case EXPR_PACK_EXPANSION:
11674 error ("invalid use of pack expansion expression");
11675 return error_mark_node;
11677 case NONTYPE_ARGUMENT_PACK:
11678 error ("use %<...%> to expand argument pack");
11679 return error_mark_node;
11682 gcc_assert (!STATEMENT_CODE_P (TREE_CODE (t)));
11684 return tsubst_copy_and_build (t, args, complain, in_decl,
11685 /*function_p=*/false,
11686 integral_constant_expression_p);
11693 /* T is a postfix-expression that is not being used in a function
11694 call. Return the substituted version of T. */
11697 tsubst_non_call_postfix_expression (tree t, tree args,
11698 tsubst_flags_t complain,
11701 if (TREE_CODE (t) == SCOPE_REF)
11702 t = tsubst_qualified_id (t, args, complain, in_decl,
11703 /*done=*/false, /*address_p=*/false);
11705 t = tsubst_copy_and_build (t, args, complain, in_decl,
11706 /*function_p=*/false,
11707 /*integral_constant_expression_p=*/false);
11712 /* Like tsubst but deals with expressions and performs semantic
11713 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
11716 tsubst_copy_and_build (tree t,
11718 tsubst_flags_t complain,
11721 bool integral_constant_expression_p)
11723 #define RECUR(NODE) \
11724 tsubst_copy_and_build (NODE, args, complain, in_decl, \
11725 /*function_p=*/false, \
11726 integral_constant_expression_p)
11730 if (t == NULL_TREE || t == error_mark_node)
11733 switch (TREE_CODE (t))
11737 /* Fall through. */
11738 case IDENTIFIER_NODE:
11742 bool non_integral_constant_expression_p;
11743 const char *error_msg;
11745 if (IDENTIFIER_TYPENAME_P (t))
11747 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
11748 t = mangle_conv_op_name_for_type (new_type);
11751 /* Look up the name. */
11752 decl = lookup_name (t);
11754 /* By convention, expressions use ERROR_MARK_NODE to indicate
11755 failure, not NULL_TREE. */
11756 if (decl == NULL_TREE)
11757 decl = error_mark_node;
11759 decl = finish_id_expression (t, decl, NULL_TREE,
11761 integral_constant_expression_p,
11762 /*allow_non_integral_constant_expression_p=*/false,
11763 &non_integral_constant_expression_p,
11764 /*template_p=*/false,
11766 /*address_p=*/false,
11767 /*template_arg_p=*/false,
11772 if (!function_p && TREE_CODE (decl) == IDENTIFIER_NODE)
11773 decl = unqualified_name_lookup_error (decl);
11777 case TEMPLATE_ID_EXPR:
11780 tree templ = RECUR (TREE_OPERAND (t, 0));
11781 tree targs = TREE_OPERAND (t, 1);
11784 targs = tsubst_template_args (targs, args, complain, in_decl);
11786 if (TREE_CODE (templ) == COMPONENT_REF)
11788 object = TREE_OPERAND (templ, 0);
11789 templ = TREE_OPERAND (templ, 1);
11792 object = NULL_TREE;
11793 templ = lookup_template_function (templ, targs);
11796 return build3 (COMPONENT_REF, TREE_TYPE (templ),
11797 object, templ, NULL_TREE);
11799 return baselink_for_fns (templ);
11804 tree r = RECUR (TREE_OPERAND (t, 0));
11806 if (REFERENCE_REF_P (t))
11808 /* A type conversion to reference type will be enclosed in
11809 such an indirect ref, but the substitution of the cast
11810 will have also added such an indirect ref. */
11811 if (TREE_CODE (TREE_TYPE (r)) == REFERENCE_TYPE)
11812 r = convert_from_reference (r);
11815 r = build_x_indirect_ref (r, "unary *", complain);
11821 (tsubst (TREE_TYPE (t), args, complain, in_decl),
11822 RECUR (TREE_OPERAND (t, 0)));
11825 case REINTERPRET_CAST_EXPR:
11826 case CONST_CAST_EXPR:
11827 case DYNAMIC_CAST_EXPR:
11828 case STATIC_CAST_EXPR:
11833 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
11834 if (integral_constant_expression_p
11835 && !cast_valid_in_integral_constant_expression_p (type))
11837 if (complain & tf_error)
11838 error ("a cast to a type other than an integral or "
11839 "enumeration type cannot appear in a constant-expression");
11840 return error_mark_node;
11843 op = RECUR (TREE_OPERAND (t, 0));
11845 switch (TREE_CODE (t))
11848 return build_functional_cast (type, op, complain);
11849 case REINTERPRET_CAST_EXPR:
11850 return build_reinterpret_cast (type, op, complain);
11851 case CONST_CAST_EXPR:
11852 return build_const_cast (type, op, complain);
11853 case DYNAMIC_CAST_EXPR:
11854 return build_dynamic_cast (type, op, complain);
11855 case STATIC_CAST_EXPR:
11856 return build_static_cast (type, op, complain);
11858 gcc_unreachable ();
11862 case POSTDECREMENT_EXPR:
11863 case POSTINCREMENT_EXPR:
11864 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
11865 args, complain, in_decl);
11866 return build_x_unary_op (TREE_CODE (t), op1, complain);
11868 case PREDECREMENT_EXPR:
11869 case PREINCREMENT_EXPR:
11873 case TRUTH_NOT_EXPR:
11874 case UNARY_PLUS_EXPR: /* Unary + */
11875 case REALPART_EXPR:
11876 case IMAGPART_EXPR:
11877 return build_x_unary_op (TREE_CODE (t), RECUR (TREE_OPERAND (t, 0)),
11881 op1 = TREE_OPERAND (t, 0);
11882 if (TREE_CODE (op1) == SCOPE_REF)
11883 op1 = tsubst_qualified_id (op1, args, complain, in_decl,
11884 /*done=*/true, /*address_p=*/true);
11886 op1 = tsubst_non_call_postfix_expression (op1, args, complain,
11888 if (TREE_CODE (op1) == LABEL_DECL)
11889 return finish_label_address_expr (DECL_NAME (op1),
11890 EXPR_LOCATION (op1));
11891 return build_x_unary_op (ADDR_EXPR, op1, complain);
11896 case TRUNC_DIV_EXPR:
11897 case CEIL_DIV_EXPR:
11898 case FLOOR_DIV_EXPR:
11899 case ROUND_DIV_EXPR:
11900 case EXACT_DIV_EXPR:
11904 case TRUNC_MOD_EXPR:
11905 case FLOOR_MOD_EXPR:
11906 case TRUTH_ANDIF_EXPR:
11907 case TRUTH_ORIF_EXPR:
11908 case TRUTH_AND_EXPR:
11909 case TRUTH_OR_EXPR:
11924 return build_x_binary_op
11926 RECUR (TREE_OPERAND (t, 0)),
11927 (TREE_NO_WARNING (TREE_OPERAND (t, 0))
11929 : TREE_CODE (TREE_OPERAND (t, 0))),
11930 RECUR (TREE_OPERAND (t, 1)),
11931 (TREE_NO_WARNING (TREE_OPERAND (t, 1))
11933 : TREE_CODE (TREE_OPERAND (t, 1))),
11934 /*overloaded_p=*/NULL,
11938 return tsubst_qualified_id (t, args, complain, in_decl, /*done=*/true,
11939 /*address_p=*/false);
11941 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
11942 args, complain, in_decl);
11943 return build_x_array_ref (op1, RECUR (TREE_OPERAND (t, 1)), complain);
11946 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
11947 return tsubst_copy (t, args, complain, in_decl);
11951 op1 = TREE_OPERAND (t, 0);
11954 /* When there are no ARGS, we are trying to evaluate a
11955 non-dependent expression from the parser. Trying to do
11956 the substitutions may not work. */
11958 op1 = TREE_TYPE (op1);
11962 ++cp_unevaluated_operand;
11963 ++c_inhibit_evaluation_warnings;
11964 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
11965 /*function_p=*/false,
11966 /*integral_constant_expression_p=*/false);
11967 --cp_unevaluated_operand;
11968 --c_inhibit_evaluation_warnings;
11971 return cxx_sizeof_or_alignof_type (op1, TREE_CODE (t),
11972 complain & tf_error);
11974 return cxx_sizeof_or_alignof_expr (op1, TREE_CODE (t),
11975 complain & tf_error);
11979 tree r = build_x_modify_expr
11980 (RECUR (TREE_OPERAND (t, 0)),
11981 TREE_CODE (TREE_OPERAND (t, 1)),
11982 RECUR (TREE_OPERAND (t, 2)),
11984 /* TREE_NO_WARNING must be set if either the expression was
11985 parenthesized or it uses an operator such as >>= rather
11986 than plain assignment. In the former case, it was already
11987 set and must be copied. In the latter case,
11988 build_x_modify_expr sets it and it must not be reset
11990 if (TREE_NO_WARNING (t))
11991 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
11996 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
11997 args, complain, in_decl);
11998 /* Remember that there was a reference to this entity. */
12001 return build_x_arrow (op1);
12005 tree placement = RECUR (TREE_OPERAND (t, 0));
12006 tree init = RECUR (TREE_OPERAND (t, 3));
12007 VEC(tree,gc) *placement_vec;
12008 VEC(tree,gc) *init_vec;
12011 if (placement == NULL_TREE)
12012 placement_vec = NULL;
12015 placement_vec = make_tree_vector ();
12016 for (; placement != NULL_TREE; placement = TREE_CHAIN (placement))
12017 VEC_safe_push (tree, gc, placement_vec, TREE_VALUE (placement));
12020 /* If there was an initializer in the original tree, but it
12021 instantiated to an empty list, then we should pass a
12022 non-NULL empty vector to tell build_new that it was an
12023 empty initializer() rather than no initializer. This can
12024 only happen when the initializer is a pack expansion whose
12025 parameter packs are of length zero. */
12026 if (init == NULL_TREE && TREE_OPERAND (t, 3) == NULL_TREE)
12030 init_vec = make_tree_vector ();
12031 if (init == void_zero_node)
12032 gcc_assert (init_vec != NULL);
12035 for (; init != NULL_TREE; init = TREE_CHAIN (init))
12036 VEC_safe_push (tree, gc, init_vec, TREE_VALUE (init));
12040 ret = build_new (&placement_vec,
12041 RECUR (TREE_OPERAND (t, 1)),
12042 RECUR (TREE_OPERAND (t, 2)),
12044 NEW_EXPR_USE_GLOBAL (t),
12047 if (placement_vec != NULL)
12048 release_tree_vector (placement_vec);
12049 if (init_vec != NULL)
12050 release_tree_vector (init_vec);
12056 return delete_sanity
12057 (RECUR (TREE_OPERAND (t, 0)),
12058 RECUR (TREE_OPERAND (t, 1)),
12059 DELETE_EXPR_USE_VEC (t),
12060 DELETE_EXPR_USE_GLOBAL (t));
12062 case COMPOUND_EXPR:
12063 return build_x_compound_expr (RECUR (TREE_OPERAND (t, 0)),
12064 RECUR (TREE_OPERAND (t, 1)),
12070 VEC(tree,gc) *call_args;
12071 unsigned int nargs, i;
12076 function = CALL_EXPR_FN (t);
12077 /* When we parsed the expression, we determined whether or
12078 not Koenig lookup should be performed. */
12079 koenig_p = KOENIG_LOOKUP_P (t);
12080 if (TREE_CODE (function) == SCOPE_REF)
12082 qualified_p = true;
12083 function = tsubst_qualified_id (function, args, complain, in_decl,
12085 /*address_p=*/false);
12089 if (TREE_CODE (function) == COMPONENT_REF)
12091 tree op = TREE_OPERAND (function, 1);
12093 qualified_p = (TREE_CODE (op) == SCOPE_REF
12094 || (BASELINK_P (op)
12095 && BASELINK_QUALIFIED_P (op)));
12098 qualified_p = false;
12100 function = tsubst_copy_and_build (function, args, complain,
12103 integral_constant_expression_p);
12105 if (BASELINK_P (function))
12106 qualified_p = true;
12109 nargs = call_expr_nargs (t);
12110 call_args = make_tree_vector ();
12111 for (i = 0; i < nargs; ++i)
12113 tree arg = CALL_EXPR_ARG (t, i);
12115 if (!PACK_EXPANSION_P (arg))
12116 VEC_safe_push (tree, gc, call_args,
12117 RECUR (CALL_EXPR_ARG (t, i)));
12120 /* Expand the pack expansion and push each entry onto
12122 arg = tsubst_pack_expansion (arg, args, complain, in_decl);
12123 if (TREE_CODE (arg) == TREE_VEC)
12125 unsigned int len, j;
12127 len = TREE_VEC_LENGTH (arg);
12128 for (j = 0; j < len; ++j)
12130 tree value = TREE_VEC_ELT (arg, j);
12131 if (value != NULL_TREE)
12132 value = convert_from_reference (value);
12133 VEC_safe_push (tree, gc, call_args, value);
12138 /* A partial substitution. Add one entry. */
12139 VEC_safe_push (tree, gc, call_args, arg);
12144 /* We do not perform argument-dependent lookup if normal
12145 lookup finds a non-function, in accordance with the
12146 expected resolution of DR 218. */
12148 && ((is_overloaded_fn (function)
12149 /* If lookup found a member function, the Koenig lookup is
12150 not appropriate, even if an unqualified-name was used
12151 to denote the function. */
12152 && !DECL_FUNCTION_MEMBER_P (get_first_fn (function)))
12153 || TREE_CODE (function) == IDENTIFIER_NODE)
12154 /* Only do this when substitution turns a dependent call
12155 into a non-dependent call. */
12156 && type_dependent_expression_p_push (t)
12157 && !any_type_dependent_arguments_p (call_args))
12158 function = perform_koenig_lookup (function, call_args);
12160 if (TREE_CODE (function) == IDENTIFIER_NODE)
12162 unqualified_name_lookup_error (function);
12163 release_tree_vector (call_args);
12164 return error_mark_node;
12167 /* Remember that there was a reference to this entity. */
12168 if (DECL_P (function))
12169 mark_used (function);
12171 if (TREE_CODE (function) == OFFSET_REF)
12172 ret = build_offset_ref_call_from_tree (function, &call_args);
12173 else if (TREE_CODE (function) == COMPONENT_REF)
12175 if (!BASELINK_P (TREE_OPERAND (function, 1)))
12176 ret = finish_call_expr (function, &call_args,
12177 /*disallow_virtual=*/false,
12178 /*koenig_p=*/false,
12181 ret = (build_new_method_call
12182 (TREE_OPERAND (function, 0),
12183 TREE_OPERAND (function, 1),
12184 &call_args, NULL_TREE,
12185 qualified_p ? LOOKUP_NONVIRTUAL : LOOKUP_NORMAL,
12190 ret = finish_call_expr (function, &call_args,
12191 /*disallow_virtual=*/qualified_p,
12195 release_tree_vector (call_args);
12201 return build_x_conditional_expr
12202 (RECUR (TREE_OPERAND (t, 0)),
12203 RECUR (TREE_OPERAND (t, 1)),
12204 RECUR (TREE_OPERAND (t, 2)),
12207 case PSEUDO_DTOR_EXPR:
12208 return finish_pseudo_destructor_expr
12209 (RECUR (TREE_OPERAND (t, 0)),
12210 RECUR (TREE_OPERAND (t, 1)),
12211 RECUR (TREE_OPERAND (t, 2)));
12215 tree purpose, value, chain;
12217 if (t == void_list_node)
12220 if ((TREE_PURPOSE (t) && PACK_EXPANSION_P (TREE_PURPOSE (t)))
12221 || (TREE_VALUE (t) && PACK_EXPANSION_P (TREE_VALUE (t))))
12223 /* We have pack expansions, so expand those and
12224 create a new list out of it. */
12225 tree purposevec = NULL_TREE;
12226 tree valuevec = NULL_TREE;
12230 /* Expand the argument expressions. */
12231 if (TREE_PURPOSE (t))
12232 purposevec = tsubst_pack_expansion (TREE_PURPOSE (t), args,
12233 complain, in_decl);
12234 if (TREE_VALUE (t))
12235 valuevec = tsubst_pack_expansion (TREE_VALUE (t), args,
12236 complain, in_decl);
12238 /* Build the rest of the list. */
12239 chain = TREE_CHAIN (t);
12240 if (chain && chain != void_type_node)
12241 chain = RECUR (chain);
12243 /* Determine the number of arguments. */
12244 if (purposevec && TREE_CODE (purposevec) == TREE_VEC)
12246 len = TREE_VEC_LENGTH (purposevec);
12247 gcc_assert (!valuevec || len == TREE_VEC_LENGTH (valuevec));
12249 else if (TREE_CODE (valuevec) == TREE_VEC)
12250 len = TREE_VEC_LENGTH (valuevec);
12253 /* Since we only performed a partial substitution into
12254 the argument pack, we only return a single list
12256 if (purposevec == TREE_PURPOSE (t)
12257 && valuevec == TREE_VALUE (t)
12258 && chain == TREE_CHAIN (t))
12261 return tree_cons (purposevec, valuevec, chain);
12264 /* Convert the argument vectors into a TREE_LIST */
12268 /* Grab the Ith values. */
12270 purpose = purposevec ? TREE_VEC_ELT (purposevec, i)
12273 = valuevec ? convert_from_reference (TREE_VEC_ELT (valuevec, i))
12276 /* Build the list (backwards). */
12277 chain = tree_cons (purpose, value, chain);
12283 purpose = TREE_PURPOSE (t);
12285 purpose = RECUR (purpose);
12286 value = TREE_VALUE (t);
12288 value = RECUR (value);
12289 chain = TREE_CHAIN (t);
12290 if (chain && chain != void_type_node)
12291 chain = RECUR (chain);
12292 if (purpose == TREE_PURPOSE (t)
12293 && value == TREE_VALUE (t)
12294 && chain == TREE_CHAIN (t))
12296 return tree_cons (purpose, value, chain);
12299 case COMPONENT_REF:
12305 object = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
12306 args, complain, in_decl);
12307 /* Remember that there was a reference to this entity. */
12308 if (DECL_P (object))
12309 mark_used (object);
12310 object_type = TREE_TYPE (object);
12312 member = TREE_OPERAND (t, 1);
12313 if (BASELINK_P (member))
12314 member = tsubst_baselink (member,
12315 non_reference (TREE_TYPE (object)),
12316 args, complain, in_decl);
12318 member = tsubst_copy (member, args, complain, in_decl);
12319 if (member == error_mark_node)
12320 return error_mark_node;
12322 if (object_type && !CLASS_TYPE_P (object_type))
12324 if (SCALAR_TYPE_P (object_type))
12326 tree s = NULL_TREE;
12327 tree dtor = member;
12329 if (TREE_CODE (dtor) == SCOPE_REF)
12331 s = TREE_OPERAND (dtor, 0);
12332 dtor = TREE_OPERAND (dtor, 1);
12334 if (TREE_CODE (dtor) == BIT_NOT_EXPR)
12336 dtor = TREE_OPERAND (dtor, 0);
12338 return finish_pseudo_destructor_expr (object, s, dtor);
12342 else if (TREE_CODE (member) == SCOPE_REF
12343 && TREE_CODE (TREE_OPERAND (member, 1)) == TEMPLATE_ID_EXPR)
12348 /* Lookup the template functions now that we know what the
12350 tmpl = TREE_OPERAND (TREE_OPERAND (member, 1), 0);
12351 args = TREE_OPERAND (TREE_OPERAND (member, 1), 1);
12352 member = lookup_qualified_name (TREE_OPERAND (member, 0), tmpl,
12353 /*is_type_p=*/false,
12354 /*complain=*/false);
12355 if (BASELINK_P (member))
12357 BASELINK_FUNCTIONS (member)
12358 = build_nt (TEMPLATE_ID_EXPR, BASELINK_FUNCTIONS (member),
12360 member = (adjust_result_of_qualified_name_lookup
12361 (member, BINFO_TYPE (BASELINK_BINFO (member)),
12366 qualified_name_lookup_error (object_type, tmpl, member,
12368 return error_mark_node;
12371 else if (TREE_CODE (member) == SCOPE_REF
12372 && !CLASS_TYPE_P (TREE_OPERAND (member, 0))
12373 && TREE_CODE (TREE_OPERAND (member, 0)) != NAMESPACE_DECL)
12375 if (complain & tf_error)
12377 if (TYPE_P (TREE_OPERAND (member, 0)))
12378 error ("%qT is not a class or namespace",
12379 TREE_OPERAND (member, 0));
12381 error ("%qD is not a class or namespace",
12382 TREE_OPERAND (member, 0));
12384 return error_mark_node;
12386 else if (TREE_CODE (member) == FIELD_DECL)
12387 return finish_non_static_data_member (member, object, NULL_TREE);
12389 return finish_class_member_access_expr (object, member,
12390 /*template_p=*/false,
12396 (RECUR (TREE_OPERAND (t, 0)));
12400 VEC(constructor_elt,gc) *n;
12401 constructor_elt *ce;
12402 unsigned HOST_WIDE_INT idx;
12403 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12404 bool process_index_p;
12406 bool need_copy_p = false;
12409 if (type == error_mark_node)
12410 return error_mark_node;
12412 /* digest_init will do the wrong thing if we let it. */
12413 if (type && TYPE_PTRMEMFUNC_P (type))
12416 /* We do not want to process the index of aggregate
12417 initializers as they are identifier nodes which will be
12418 looked up by digest_init. */
12419 process_index_p = !(type && MAYBE_CLASS_TYPE_P (type));
12421 n = VEC_copy (constructor_elt, gc, CONSTRUCTOR_ELTS (t));
12422 newlen = VEC_length (constructor_elt, n);
12423 for (idx = 0; VEC_iterate (constructor_elt, n, idx, ce); idx++)
12425 if (ce->index && process_index_p)
12426 ce->index = RECUR (ce->index);
12428 if (PACK_EXPANSION_P (ce->value))
12430 /* Substitute into the pack expansion. */
12431 ce->value = tsubst_pack_expansion (ce->value, args, complain,
12434 if (ce->value == error_mark_node)
12436 else if (TREE_VEC_LENGTH (ce->value) == 1)
12437 /* Just move the argument into place. */
12438 ce->value = TREE_VEC_ELT (ce->value, 0);
12441 /* Update the length of the final CONSTRUCTOR
12442 arguments vector, and note that we will need to
12444 newlen = newlen + TREE_VEC_LENGTH (ce->value) - 1;
12445 need_copy_p = true;
12449 ce->value = RECUR (ce->value);
12454 VEC(constructor_elt,gc) *old_n = n;
12456 n = VEC_alloc (constructor_elt, gc, newlen);
12457 for (idx = 0; VEC_iterate (constructor_elt, old_n, idx, ce);
12460 if (TREE_CODE (ce->value) == TREE_VEC)
12462 int i, len = TREE_VEC_LENGTH (ce->value);
12463 for (i = 0; i < len; ++i)
12464 CONSTRUCTOR_APPEND_ELT (n, 0,
12465 TREE_VEC_ELT (ce->value, i));
12468 CONSTRUCTOR_APPEND_ELT (n, 0, ce->value);
12472 r = build_constructor (init_list_type_node, n);
12473 CONSTRUCTOR_IS_DIRECT_INIT (r) = CONSTRUCTOR_IS_DIRECT_INIT (t);
12475 if (TREE_HAS_CONSTRUCTOR (t))
12476 return finish_compound_literal (type, r);
12483 tree operand_0 = RECUR (TREE_OPERAND (t, 0));
12484 if (TYPE_P (operand_0))
12485 return get_typeid (operand_0);
12486 return build_typeid (operand_0);
12496 tree r = tsubst_copy (t, args, complain, in_decl);
12498 if (TREE_CODE (TREE_TYPE (t)) != REFERENCE_TYPE)
12499 /* If the original type was a reference, we'll be wrapped in
12500 the appropriate INDIRECT_REF. */
12501 r = convert_from_reference (r);
12506 return build_x_va_arg (RECUR (TREE_OPERAND (t, 0)),
12507 tsubst_copy (TREE_TYPE (t), args, complain,
12510 case OFFSETOF_EXPR:
12511 return finish_offsetof (RECUR (TREE_OPERAND (t, 0)));
12515 tree type1 = tsubst_copy (TRAIT_EXPR_TYPE1 (t), args,
12516 complain, in_decl);
12518 tree type2 = TRAIT_EXPR_TYPE2 (t);
12520 type2 = tsubst_copy (type2, args, complain, in_decl);
12522 return finish_trait_expr (TRAIT_EXPR_KIND (t), type1, type2);
12527 tree old_stmt_expr = cur_stmt_expr;
12528 tree stmt_expr = begin_stmt_expr ();
12530 cur_stmt_expr = stmt_expr;
12531 tsubst_expr (STMT_EXPR_STMT (t), args, complain, in_decl,
12532 integral_constant_expression_p);
12533 stmt_expr = finish_stmt_expr (stmt_expr, false);
12534 cur_stmt_expr = old_stmt_expr;
12540 t = tsubst_copy (t, args, complain, in_decl);
12541 /* As in finish_id_expression, we resolve enumeration constants
12542 to their underlying values. */
12543 if (TREE_CODE (t) == CONST_DECL)
12545 used_types_insert (TREE_TYPE (t));
12546 return DECL_INITIAL (t);
12552 tree r = build_lambda_expr ();
12554 tree type = tsubst (TREE_TYPE (t), args, complain, NULL_TREE);
12555 TREE_TYPE (r) = type;
12556 CLASSTYPE_LAMBDA_EXPR (type) = r;
12558 LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (r)
12559 = LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (t);
12560 LAMBDA_EXPR_MUTABLE_P (r) = LAMBDA_EXPR_MUTABLE_P (t);
12561 LAMBDA_EXPR_DISCRIMINATOR (r)
12562 = (LAMBDA_EXPR_DISCRIMINATOR (t));
12563 LAMBDA_EXPR_CAPTURE_LIST (r)
12564 = RECUR (LAMBDA_EXPR_CAPTURE_LIST (t));
12565 LAMBDA_EXPR_THIS_CAPTURE (r)
12566 = RECUR (LAMBDA_EXPR_THIS_CAPTURE (t));
12567 LAMBDA_EXPR_EXTRA_SCOPE (r)
12568 = RECUR (LAMBDA_EXPR_EXTRA_SCOPE (t));
12570 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
12571 determine_visibility (TYPE_NAME (type));
12572 /* Now that we know visibility, instantiate the type so we have a
12573 declaration of the op() for later calls to lambda_function. */
12574 complete_type (type);
12576 type = tsubst (LAMBDA_EXPR_RETURN_TYPE (t), args, complain, in_decl);
12578 apply_lambda_return_type (r, type);
12580 return build_lambda_object (r);
12584 /* Handle Objective-C++ constructs, if appropriate. */
12587 = objcp_tsubst_copy_and_build (t, args, complain,
12588 in_decl, /*function_p=*/false);
12592 return tsubst_copy (t, args, complain, in_decl);
12598 /* Verify that the instantiated ARGS are valid. For type arguments,
12599 make sure that the type's linkage is ok. For non-type arguments,
12600 make sure they are constants if they are integral or enumerations.
12601 Emit an error under control of COMPLAIN, and return TRUE on error. */
12604 check_instantiated_arg (tree tmpl, tree t, tsubst_flags_t complain)
12606 if (ARGUMENT_PACK_P (t))
12608 tree vec = ARGUMENT_PACK_ARGS (t);
12609 int len = TREE_VEC_LENGTH (vec);
12610 bool result = false;
12613 for (i = 0; i < len; ++i)
12614 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (vec, i), complain))
12618 else if (TYPE_P (t))
12620 /* [basic.link]: A name with no linkage (notably, the name
12621 of a class or enumeration declared in a local scope)
12622 shall not be used to declare an entity with linkage.
12623 This implies that names with no linkage cannot be used as
12626 DR 757 relaxes this restriction for C++0x. */
12627 tree nt = (cxx_dialect > cxx98 ? NULL_TREE
12628 : no_linkage_check (t, /*relaxed_p=*/false));
12632 /* DR 488 makes use of a type with no linkage cause
12633 type deduction to fail. */
12634 if (complain & tf_error)
12636 if (TYPE_ANONYMOUS_P (nt))
12637 error ("%qT is/uses anonymous type", t);
12639 error ("template argument for %qD uses local type %qT",
12644 /* In order to avoid all sorts of complications, we do not
12645 allow variably-modified types as template arguments. */
12646 else if (variably_modified_type_p (t, NULL_TREE))
12648 if (complain & tf_error)
12649 error ("%qT is a variably modified type", t);
12653 /* A non-type argument of integral or enumerated type must be a
12655 else if (TREE_TYPE (t)
12656 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t))
12657 && !TREE_CONSTANT (t))
12659 if (complain & tf_error)
12660 error ("integral expression %qE is not constant", t);
12667 check_instantiated_args (tree tmpl, tree args, tsubst_flags_t complain)
12669 int ix, len = DECL_NTPARMS (tmpl);
12670 bool result = false;
12672 for (ix = 0; ix != len; ix++)
12674 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (args, ix), complain))
12677 if (result && (complain & tf_error))
12678 error (" trying to instantiate %qD", tmpl);
12682 /* Instantiate the indicated variable or function template TMPL with
12683 the template arguments in TARG_PTR. */
12686 instantiate_template (tree tmpl, tree orig_args, tsubst_flags_t complain)
12688 tree targ_ptr = orig_args;
12692 HOST_WIDE_INT saved_processing_template_decl;
12694 if (tmpl == error_mark_node)
12695 return error_mark_node;
12697 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
12699 /* If this function is a clone, handle it specially. */
12700 if (DECL_CLONED_FUNCTION_P (tmpl))
12705 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
12706 DECL_CLONED_FUNCTION. */
12707 spec = instantiate_template (DECL_ABSTRACT_ORIGIN (tmpl),
12708 targ_ptr, complain);
12709 if (spec == error_mark_node)
12710 return error_mark_node;
12712 /* Look for the clone. */
12713 FOR_EACH_CLONE (clone, spec)
12714 if (DECL_NAME (clone) == DECL_NAME (tmpl))
12716 /* We should always have found the clone by now. */
12717 gcc_unreachable ();
12721 /* Check to see if we already have this specialization. */
12722 gen_tmpl = most_general_template (tmpl);
12723 if (tmpl != gen_tmpl)
12724 /* The TMPL is a partial instantiation. To get a full set of
12725 arguments we must add the arguments used to perform the
12726 partial instantiation. */
12727 targ_ptr = add_outermost_template_args (DECL_TI_ARGS (tmpl),
12730 /* It would be nice to avoid hashing here and then again in tsubst_decl,
12731 but it doesn't seem to be on the hot path. */
12732 spec = retrieve_specialization (gen_tmpl, targ_ptr, 0);
12734 gcc_assert (tmpl == gen_tmpl
12735 || ((fndecl = retrieve_specialization (tmpl, orig_args, 0))
12737 || fndecl == NULL_TREE);
12739 if (spec != NULL_TREE)
12742 if (check_instantiated_args (gen_tmpl, INNERMOST_TEMPLATE_ARGS (targ_ptr),
12744 return error_mark_node;
12746 /* We are building a FUNCTION_DECL, during which the access of its
12747 parameters and return types have to be checked. However this
12748 FUNCTION_DECL which is the desired context for access checking
12749 is not built yet. We solve this chicken-and-egg problem by
12750 deferring all checks until we have the FUNCTION_DECL. */
12751 push_deferring_access_checks (dk_deferred);
12753 /* Although PROCESSING_TEMPLATE_DECL may be true at this point
12754 (because, for example, we have encountered a non-dependent
12755 function call in the body of a template function and must now
12756 determine which of several overloaded functions will be called),
12757 within the instantiation itself we are not processing a
12759 saved_processing_template_decl = processing_template_decl;
12760 processing_template_decl = 0;
12761 /* Substitute template parameters to obtain the specialization. */
12762 fndecl = tsubst (DECL_TEMPLATE_RESULT (gen_tmpl),
12763 targ_ptr, complain, gen_tmpl);
12764 processing_template_decl = saved_processing_template_decl;
12765 if (fndecl == error_mark_node)
12766 return error_mark_node;
12768 /* Now we know the specialization, compute access previously
12770 push_access_scope (fndecl);
12772 /* Some typedefs referenced from within the template code need to be access
12773 checked at template instantiation time, i.e now. These types were
12774 added to the template at parsing time. Let's get those and perfom
12775 the acces checks then. */
12776 perform_typedefs_access_check (DECL_TEMPLATE_RESULT (tmpl), targ_ptr);
12777 perform_deferred_access_checks ();
12778 pop_access_scope (fndecl);
12779 pop_deferring_access_checks ();
12781 /* The DECL_TI_TEMPLATE should always be the immediate parent
12782 template, not the most general template. */
12783 DECL_TI_TEMPLATE (fndecl) = tmpl;
12785 /* If we've just instantiated the main entry point for a function,
12786 instantiate all the alternate entry points as well. We do this
12787 by cloning the instantiation of the main entry point, not by
12788 instantiating the template clones. */
12789 if (TREE_CHAIN (gen_tmpl) && DECL_CLONED_FUNCTION_P (TREE_CHAIN (gen_tmpl)))
12790 clone_function_decl (fndecl, /*update_method_vec_p=*/0);
12795 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
12796 NARGS elements of the arguments that are being used when calling
12797 it. TARGS is a vector into which the deduced template arguments
12800 Return zero for success, 2 for an incomplete match that doesn't resolve
12801 all the types, and 1 for complete failure. An error message will be
12802 printed only for an incomplete match.
12804 If FN is a conversion operator, or we are trying to produce a specific
12805 specialization, RETURN_TYPE is the return type desired.
12807 The EXPLICIT_TARGS are explicit template arguments provided via a
12810 The parameter STRICT is one of:
12813 We are deducing arguments for a function call, as in
12814 [temp.deduct.call].
12817 We are deducing arguments for a conversion function, as in
12818 [temp.deduct.conv].
12821 We are deducing arguments when doing an explicit instantiation
12822 as in [temp.explicit], when determining an explicit specialization
12823 as in [temp.expl.spec], or when taking the address of a function
12824 template, as in [temp.deduct.funcaddr]. */
12827 fn_type_unification (tree fn,
12828 tree explicit_targs,
12831 unsigned int nargs,
12833 unification_kind_t strict,
12839 bool incomplete_argument_packs_p = false;
12841 gcc_assert (TREE_CODE (fn) == TEMPLATE_DECL);
12843 fntype = TREE_TYPE (fn);
12844 if (explicit_targs)
12848 The specified template arguments must match the template
12849 parameters in kind (i.e., type, nontype, template), and there
12850 must not be more arguments than there are parameters;
12851 otherwise type deduction fails.
12853 Nontype arguments must match the types of the corresponding
12854 nontype template parameters, or must be convertible to the
12855 types of the corresponding nontype parameters as specified in
12856 _temp.arg.nontype_, otherwise type deduction fails.
12858 All references in the function type of the function template
12859 to the corresponding template parameters are replaced by the
12860 specified template argument values. If a substitution in a
12861 template parameter or in the function type of the function
12862 template results in an invalid type, type deduction fails. */
12863 tree tparms = DECL_INNERMOST_TEMPLATE_PARMS (fn);
12864 int i, len = TREE_VEC_LENGTH (tparms);
12865 tree converted_args;
12866 bool incomplete = false;
12868 if (explicit_targs == error_mark_node)
12872 = (coerce_template_parms (tparms, explicit_targs, NULL_TREE, tf_none,
12873 /*require_all_args=*/false,
12874 /*use_default_args=*/false));
12875 if (converted_args == error_mark_node)
12878 /* Substitute the explicit args into the function type. This is
12879 necessary so that, for instance, explicitly declared function
12880 arguments can match null pointed constants. If we were given
12881 an incomplete set of explicit args, we must not do semantic
12882 processing during substitution as we could create partial
12884 for (i = 0; i < len; i++)
12886 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
12887 bool parameter_pack = false;
12889 /* Dig out the actual parm. */
12890 if (TREE_CODE (parm) == TYPE_DECL
12891 || TREE_CODE (parm) == TEMPLATE_DECL)
12893 parm = TREE_TYPE (parm);
12894 parameter_pack = TEMPLATE_TYPE_PARAMETER_PACK (parm);
12896 else if (TREE_CODE (parm) == PARM_DECL)
12898 parm = DECL_INITIAL (parm);
12899 parameter_pack = TEMPLATE_PARM_PARAMETER_PACK (parm);
12902 if (parameter_pack)
12906 template_parm_level_and_index (parm, &level, &idx);
12908 /* Mark the argument pack as "incomplete". We could
12909 still deduce more arguments during unification. */
12910 targ = TMPL_ARG (converted_args, level, idx);
12913 ARGUMENT_PACK_INCOMPLETE_P(targ) = 1;
12914 ARGUMENT_PACK_EXPLICIT_ARGS (targ)
12915 = ARGUMENT_PACK_ARGS (targ);
12918 /* We have some incomplete argument packs. */
12919 incomplete_argument_packs_p = true;
12923 if (incomplete_argument_packs_p)
12924 /* Any substitution is guaranteed to be incomplete if there
12925 are incomplete argument packs, because we can still deduce
12929 incomplete = NUM_TMPL_ARGS (explicit_targs) != NUM_TMPL_ARGS (targs);
12931 processing_template_decl += incomplete;
12932 fntype = tsubst (fntype, converted_args, tf_none, NULL_TREE);
12933 processing_template_decl -= incomplete;
12935 if (fntype == error_mark_node)
12938 /* Place the explicitly specified arguments in TARGS. */
12939 for (i = NUM_TMPL_ARGS (converted_args); i--;)
12940 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (converted_args, i);
12943 /* Never do unification on the 'this' parameter. */
12944 parms = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (fntype));
12950 parms = tree_cons (NULL_TREE, TREE_TYPE (fntype), parms);
12951 new_args = XALLOCAVEC (tree, nargs + 1);
12952 new_args[0] = return_type;
12953 memcpy (new_args + 1, args, nargs * sizeof (tree));
12958 /* We allow incomplete unification without an error message here
12959 because the standard doesn't seem to explicitly prohibit it. Our
12960 callers must be ready to deal with unification failures in any
12962 result = type_unification_real (DECL_INNERMOST_TEMPLATE_PARMS (fn),
12963 targs, parms, args, nargs, /*subr=*/0,
12966 if (result == 0 && incomplete_argument_packs_p)
12968 int i, len = NUM_TMPL_ARGS (targs);
12970 /* Clear the "incomplete" flags on all argument packs. */
12971 for (i = 0; i < len; i++)
12973 tree arg = TREE_VEC_ELT (targs, i);
12974 if (ARGUMENT_PACK_P (arg))
12976 ARGUMENT_PACK_INCOMPLETE_P (arg) = 0;
12977 ARGUMENT_PACK_EXPLICIT_ARGS (arg) = NULL_TREE;
12982 /* Now that we have bindings for all of the template arguments,
12983 ensure that the arguments deduced for the template template
12984 parameters have compatible template parameter lists. We cannot
12985 check this property before we have deduced all template
12986 arguments, because the template parameter types of a template
12987 template parameter might depend on prior template parameters
12988 deduced after the template template parameter. The following
12989 ill-formed example illustrates this issue:
12991 template<typename T, template<T> class C> void f(C<5>, T);
12993 template<int N> struct X {};
12996 f(X<5>(), 5l); // error: template argument deduction fails
12999 The template parameter list of 'C' depends on the template type
13000 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
13001 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
13002 time that we deduce 'C'. */
13004 && !template_template_parm_bindings_ok_p
13005 (DECL_INNERMOST_TEMPLATE_PARMS (fn), targs))
13009 /* All is well so far. Now, check:
13013 When all template arguments have been deduced, all uses of
13014 template parameters in nondeduced contexts are replaced with
13015 the corresponding deduced argument values. If the
13016 substitution results in an invalid type, as described above,
13017 type deduction fails. */
13019 tree substed = tsubst (TREE_TYPE (fn), targs, tf_none, NULL_TREE);
13020 if (substed == error_mark_node)
13023 /* If we're looking for an exact match, check that what we got
13024 is indeed an exact match. It might not be if some template
13025 parameters are used in non-deduced contexts. */
13026 if (strict == DEDUCE_EXACT)
13031 = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (substed));
13033 sarg = tree_cons (NULL_TREE, TREE_TYPE (substed), sarg);
13034 for (i = 0; i < nargs && sarg; ++i, sarg = TREE_CHAIN (sarg))
13035 if (!same_type_p (args[i], TREE_VALUE (sarg)))
13043 /* Adjust types before performing type deduction, as described in
13044 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
13045 sections are symmetric. PARM is the type of a function parameter
13046 or the return type of the conversion function. ARG is the type of
13047 the argument passed to the call, or the type of the value
13048 initialized with the result of the conversion function.
13049 ARG_EXPR is the original argument expression, which may be null. */
13052 maybe_adjust_types_for_deduction (unification_kind_t strict,
13066 /* Swap PARM and ARG throughout the remainder of this
13067 function; the handling is precisely symmetric since PARM
13068 will initialize ARG rather than vice versa. */
13076 /* Core issue #873: Do the DR606 thing (see below) for these cases,
13077 too, but here handle it by stripping the reference from PARM
13078 rather than by adding it to ARG. */
13079 if (TREE_CODE (*parm) == REFERENCE_TYPE
13080 && TYPE_REF_IS_RVALUE (*parm)
13081 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
13082 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
13083 && TREE_CODE (*arg) == REFERENCE_TYPE
13084 && !TYPE_REF_IS_RVALUE (*arg))
13085 *parm = TREE_TYPE (*parm);
13086 /* Nothing else to do in this case. */
13090 gcc_unreachable ();
13093 if (TREE_CODE (*parm) != REFERENCE_TYPE)
13095 /* [temp.deduct.call]
13097 If P is not a reference type:
13099 --If A is an array type, the pointer type produced by the
13100 array-to-pointer standard conversion (_conv.array_) is
13101 used in place of A for type deduction; otherwise,
13103 --If A is a function type, the pointer type produced by
13104 the function-to-pointer standard conversion
13105 (_conv.func_) is used in place of A for type deduction;
13108 --If A is a cv-qualified type, the top level
13109 cv-qualifiers of A's type are ignored for type
13111 if (TREE_CODE (*arg) == ARRAY_TYPE)
13112 *arg = build_pointer_type (TREE_TYPE (*arg));
13113 else if (TREE_CODE (*arg) == FUNCTION_TYPE)
13114 *arg = build_pointer_type (*arg);
13116 *arg = TYPE_MAIN_VARIANT (*arg);
13119 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
13120 of the form T&&, where T is a template parameter, and the argument
13121 is an lvalue, T is deduced as A& */
13122 if (TREE_CODE (*parm) == REFERENCE_TYPE
13123 && TYPE_REF_IS_RVALUE (*parm)
13124 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
13125 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
13126 && arg_expr && real_lvalue_p (arg_expr))
13127 *arg = build_reference_type (*arg);
13129 /* [temp.deduct.call]
13131 If P is a cv-qualified type, the top level cv-qualifiers
13132 of P's type are ignored for type deduction. If P is a
13133 reference type, the type referred to by P is used for
13135 *parm = TYPE_MAIN_VARIANT (*parm);
13136 if (TREE_CODE (*parm) == REFERENCE_TYPE)
13138 *parm = TREE_TYPE (*parm);
13139 result |= UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
13142 /* DR 322. For conversion deduction, remove a reference type on parm
13143 too (which has been swapped into ARG). */
13144 if (strict == DEDUCE_CONV && TREE_CODE (*arg) == REFERENCE_TYPE)
13145 *arg = TREE_TYPE (*arg);
13150 /* Most parms like fn_type_unification.
13152 If SUBR is 1, we're being called recursively (to unify the
13153 arguments of a function or method parameter of a function
13157 type_unification_real (tree tparms,
13161 unsigned int xnargs,
13163 unification_kind_t strict,
13166 tree parm, arg, arg_expr;
13168 int ntparms = TREE_VEC_LENGTH (tparms);
13170 int saw_undeduced = 0;
13173 unsigned int nargs;
13176 gcc_assert (TREE_CODE (tparms) == TREE_VEC);
13177 gcc_assert (xparms == NULL_TREE || TREE_CODE (xparms) == TREE_LIST);
13178 gcc_assert (ntparms > 0);
13183 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL | UNIFY_ALLOW_MORE_CV_QUAL
13184 | UNIFY_ALLOW_DERIVED);
13188 sub_strict = UNIFY_ALLOW_LESS_CV_QUAL;
13192 sub_strict = UNIFY_ALLOW_NONE;
13196 gcc_unreachable ();
13205 while (parms && parms != void_list_node
13208 if (TREE_CODE (TREE_VALUE (parms)) == TYPE_PACK_EXPANSION)
13211 parm = TREE_VALUE (parms);
13212 parms = TREE_CHAIN (parms);
13217 if (arg == error_mark_node)
13219 if (arg == unknown_type_node)
13220 /* We can't deduce anything from this, but we might get all the
13221 template args from other function args. */
13224 /* Conversions will be performed on a function argument that
13225 corresponds with a function parameter that contains only
13226 non-deducible template parameters and explicitly specified
13227 template parameters. */
13228 if (!uses_template_parms (parm))
13233 type = TREE_TYPE (arg);
13237 if (same_type_p (parm, type))
13239 if (strict != DEDUCE_EXACT
13240 && can_convert_arg (parm, type, TYPE_P (arg) ? NULL_TREE : arg,
13249 gcc_assert (TREE_TYPE (arg) != NULL_TREE);
13250 if (type_unknown_p (arg))
13252 /* [temp.deduct.type]
13254 A template-argument can be deduced from a pointer to
13255 function or pointer to member function argument if
13256 the set of overloaded functions does not contain
13257 function templates and at most one of a set of
13258 overloaded functions provides a unique match. */
13259 if (resolve_overloaded_unification
13260 (tparms, targs, parm, arg, strict, sub_strict))
13266 arg = unlowered_expr_type (arg);
13267 if (arg == error_mark_node)
13272 int arg_strict = sub_strict;
13275 arg_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg,
13278 if (arg == init_list_type_node && arg_expr)
13280 if (unify (tparms, targs, parm, arg, arg_strict))
13287 && parms != void_list_node
13288 && TREE_CODE (TREE_VALUE (parms)) == TYPE_PACK_EXPANSION)
13290 /* Unify the remaining arguments with the pack expansion type. */
13292 tree parmvec = make_tree_vec (1);
13294 /* Allocate a TREE_VEC and copy in all of the arguments */
13295 argvec = make_tree_vec (nargs - ia);
13296 for (i = 0; ia < nargs; ++ia, ++i)
13297 TREE_VEC_ELT (argvec, i) = args[ia];
13299 /* Copy the parameter into parmvec. */
13300 TREE_VEC_ELT (parmvec, 0) = TREE_VALUE (parms);
13301 if (unify_pack_expansion (tparms, targs, parmvec, argvec, strict,
13302 /*call_args_p=*/true, /*subr=*/subr))
13305 /* Advance to the end of the list of parameters. */
13306 parms = TREE_CHAIN (parms);
13309 /* Fail if we've reached the end of the parm list, and more args
13310 are present, and the parm list isn't variadic. */
13311 if (ia < nargs && parms == void_list_node)
13313 /* Fail if parms are left and they don't have default values. */
13314 if (parms && parms != void_list_node
13315 && TREE_PURPOSE (parms) == NULL_TREE)
13319 for (i = 0; i < ntparms; i++)
13320 if (!TREE_VEC_ELT (targs, i))
13324 if (TREE_VEC_ELT (tparms, i) == error_mark_node)
13327 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
13329 /* If this is an undeduced nontype parameter that depends on
13330 a type parameter, try another pass; its type may have been
13331 deduced from a later argument than the one from which
13332 this parameter can be deduced. */
13333 if (TREE_CODE (tparm) == PARM_DECL
13334 && uses_template_parms (TREE_TYPE (tparm))
13335 && !saw_undeduced++)
13338 /* Core issue #226 (C++0x) [temp.deduct]:
13340 If a template argument has not been deduced, its
13341 default template argument, if any, is used.
13343 When we are in C++98 mode, TREE_PURPOSE will either
13344 be NULL_TREE or ERROR_MARK_NODE, so we do not need
13345 to explicitly check cxx_dialect here. */
13346 if (TREE_PURPOSE (TREE_VEC_ELT (tparms, i)))
13348 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
13349 tree arg = TREE_PURPOSE (TREE_VEC_ELT (tparms, i));
13350 arg = tsubst_template_arg (arg, targs, tf_none, NULL_TREE);
13351 arg = convert_template_argument (parm, arg, targs, tf_none,
13353 if (arg == error_mark_node)
13357 TREE_VEC_ELT (targs, i) = arg;
13362 /* If the type parameter is a parameter pack, then it will
13363 be deduced to an empty parameter pack. */
13364 if (template_parameter_pack_p (tparm))
13368 if (TREE_CODE (tparm) == TEMPLATE_PARM_INDEX)
13370 arg = make_node (NONTYPE_ARGUMENT_PACK);
13371 TREE_TYPE (arg) = TREE_TYPE (TEMPLATE_PARM_DECL (tparm));
13372 TREE_CONSTANT (arg) = 1;
13375 arg = cxx_make_type (TYPE_ARGUMENT_PACK);
13377 SET_ARGUMENT_PACK_ARGS (arg, make_tree_vec (0));
13379 TREE_VEC_ELT (targs, i) = arg;
13389 /* Subroutine of type_unification_real. Args are like the variables
13390 at the call site. ARG is an overloaded function (or template-id);
13391 we try deducing template args from each of the overloads, and if
13392 only one succeeds, we go with that. Modifies TARGS and returns
13393 true on success. */
13396 resolve_overloaded_unification (tree tparms,
13400 unification_kind_t strict,
13403 tree tempargs = copy_node (targs);
13405 tree goodfn = NULL_TREE;
13408 if (TREE_CODE (arg) == ADDR_EXPR)
13410 arg = TREE_OPERAND (arg, 0);
13416 if (TREE_CODE (arg) == COMPONENT_REF)
13417 /* Handle `&x' where `x' is some static or non-static member
13419 arg = TREE_OPERAND (arg, 1);
13421 if (TREE_CODE (arg) == OFFSET_REF)
13422 arg = TREE_OPERAND (arg, 1);
13424 /* Strip baselink information. */
13425 if (BASELINK_P (arg))
13426 arg = BASELINK_FUNCTIONS (arg);
13428 if (TREE_CODE (arg) == TEMPLATE_ID_EXPR)
13430 /* If we got some explicit template args, we need to plug them into
13431 the affected templates before we try to unify, in case the
13432 explicit args will completely resolve the templates in question. */
13434 tree expl_subargs = TREE_OPERAND (arg, 1);
13435 arg = TREE_OPERAND (arg, 0);
13437 for (; arg; arg = OVL_NEXT (arg))
13439 tree fn = OVL_CURRENT (arg);
13440 tree subargs, elem;
13442 if (TREE_CODE (fn) != TEMPLATE_DECL)
13445 ++processing_template_decl;
13446 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
13447 expl_subargs, /*check_ret=*/false);
13450 elem = tsubst (TREE_TYPE (fn), subargs, tf_none, NULL_TREE);
13451 if (try_one_overload (tparms, targs, tempargs, parm,
13452 elem, strict, sub_strict, addr_p)
13453 && (!goodfn || !decls_match (goodfn, elem)))
13459 --processing_template_decl;
13462 else if (TREE_CODE (arg) != OVERLOAD
13463 && TREE_CODE (arg) != FUNCTION_DECL)
13464 /* If ARG is, for example, "(0, &f)" then its type will be unknown
13465 -- but the deduction does not succeed because the expression is
13466 not just the function on its own. */
13469 for (; arg; arg = OVL_NEXT (arg))
13470 if (try_one_overload (tparms, targs, tempargs, parm,
13471 TREE_TYPE (OVL_CURRENT (arg)),
13472 strict, sub_strict, addr_p)
13473 && (!goodfn || !decls_match (goodfn, OVL_CURRENT (arg))))
13475 goodfn = OVL_CURRENT (arg);
13479 /* [temp.deduct.type] A template-argument can be deduced from a pointer
13480 to function or pointer to member function argument if the set of
13481 overloaded functions does not contain function templates and at most
13482 one of a set of overloaded functions provides a unique match.
13484 So if we found multiple possibilities, we return success but don't
13485 deduce anything. */
13489 int i = TREE_VEC_LENGTH (targs);
13491 if (TREE_VEC_ELT (tempargs, i))
13492 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (tempargs, i);
13500 /* Core DR 115: In contexts where deduction is done and fails, or in
13501 contexts where deduction is not done, if a template argument list is
13502 specified and it, along with any default template arguments, identifies
13503 a single function template specialization, then the template-id is an
13504 lvalue for the function template specialization. */
13507 resolve_nondeduced_context (tree orig_expr)
13509 tree expr, offset, baselink;
13512 if (!type_unknown_p (orig_expr))
13517 offset = NULL_TREE;
13518 baselink = NULL_TREE;
13520 if (TREE_CODE (expr) == ADDR_EXPR)
13522 expr = TREE_OPERAND (expr, 0);
13525 if (TREE_CODE (expr) == OFFSET_REF)
13528 expr = TREE_OPERAND (expr, 1);
13530 if (TREE_CODE (expr) == BASELINK)
13533 expr = BASELINK_FUNCTIONS (expr);
13536 if (TREE_CODE (expr) == TEMPLATE_ID_EXPR)
13539 tree goodfn = NULL_TREE;
13541 /* If we got some explicit template args, we need to plug them into
13542 the affected templates before we try to unify, in case the
13543 explicit args will completely resolve the templates in question. */
13545 tree expl_subargs = TREE_OPERAND (expr, 1);
13546 tree arg = TREE_OPERAND (expr, 0);
13547 tree badfn = NULL_TREE;
13548 tree badargs = NULL_TREE;
13550 for (; arg; arg = OVL_NEXT (arg))
13552 tree fn = OVL_CURRENT (arg);
13553 tree subargs, elem;
13555 if (TREE_CODE (fn) != TEMPLATE_DECL)
13558 ++processing_template_decl;
13559 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
13560 expl_subargs, /*check_ret=*/false);
13561 if (subargs && !any_dependent_template_arguments_p (subargs))
13563 elem = instantiate_template (fn, subargs, tf_none);
13564 if (elem == error_mark_node)
13569 else if (elem && (!goodfn || !decls_match (goodfn, elem)))
13575 --processing_template_decl;
13581 expr = build_baselink (BASELINK_BINFO (baselink),
13582 BASELINK_ACCESS_BINFO (baselink),
13583 expr, BASELINK_OPTYPE (baselink));
13585 expr = build2 (OFFSET_REF, TREE_TYPE (expr),
13586 TREE_OPERAND (offset, 0), expr);
13588 expr = build_address (expr);
13591 else if (good == 0 && badargs)
13592 /* There were no good options and at least one bad one, so let the
13593 user know what the problem is. */
13594 instantiate_template (badfn, badargs, tf_warning_or_error);
13599 /* Subroutine of resolve_overloaded_unification; does deduction for a single
13600 overload. Fills TARGS with any deduced arguments, or error_mark_node if
13601 different overloads deduce different arguments for a given parm.
13602 ADDR_P is true if the expression for which deduction is being
13603 performed was of the form "& fn" rather than simply "fn".
13605 Returns 1 on success. */
13608 try_one_overload (tree tparms,
13613 unification_kind_t strict,
13621 /* [temp.deduct.type] A template-argument can be deduced from a pointer
13622 to function or pointer to member function argument if the set of
13623 overloaded functions does not contain function templates and at most
13624 one of a set of overloaded functions provides a unique match.
13626 So if this is a template, just return success. */
13628 if (uses_template_parms (arg))
13631 if (TREE_CODE (arg) == METHOD_TYPE)
13632 arg = build_ptrmemfunc_type (build_pointer_type (arg));
13634 arg = build_pointer_type (arg);
13636 sub_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg, NULL);
13638 /* We don't copy orig_targs for this because if we have already deduced
13639 some template args from previous args, unify would complain when we
13640 try to deduce a template parameter for the same argument, even though
13641 there isn't really a conflict. */
13642 nargs = TREE_VEC_LENGTH (targs);
13643 tempargs = make_tree_vec (nargs);
13645 if (unify (tparms, tempargs, parm, arg, sub_strict) != 0)
13648 /* First make sure we didn't deduce anything that conflicts with
13649 explicitly specified args. */
13650 for (i = nargs; i--; )
13652 tree elt = TREE_VEC_ELT (tempargs, i);
13653 tree oldelt = TREE_VEC_ELT (orig_targs, i);
13657 else if (uses_template_parms (elt))
13658 /* Since we're unifying against ourselves, we will fill in
13659 template args used in the function parm list with our own
13660 template parms. Discard them. */
13661 TREE_VEC_ELT (tempargs, i) = NULL_TREE;
13662 else if (oldelt && !template_args_equal (oldelt, elt))
13666 for (i = nargs; i--; )
13668 tree elt = TREE_VEC_ELT (tempargs, i);
13671 TREE_VEC_ELT (targs, i) = elt;
13677 /* PARM is a template class (perhaps with unbound template
13678 parameters). ARG is a fully instantiated type. If ARG can be
13679 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
13680 TARGS are as for unify. */
13683 try_class_unification (tree tparms, tree targs, tree parm, tree arg)
13685 tree copy_of_targs;
13687 if (!CLASSTYPE_TEMPLATE_INFO (arg)
13688 || (most_general_template (CLASSTYPE_TI_TEMPLATE (arg))
13689 != most_general_template (CLASSTYPE_TI_TEMPLATE (parm))))
13692 /* We need to make a new template argument vector for the call to
13693 unify. If we used TARGS, we'd clutter it up with the result of
13694 the attempted unification, even if this class didn't work out.
13695 We also don't want to commit ourselves to all the unifications
13696 we've already done, since unification is supposed to be done on
13697 an argument-by-argument basis. In other words, consider the
13698 following pathological case:
13700 template <int I, int J, int K>
13703 template <int I, int J>
13704 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
13706 template <int I, int J, int K>
13707 void f(S<I, J, K>, S<I, I, I>);
13716 Now, by the time we consider the unification involving `s2', we
13717 already know that we must have `f<0, 0, 0>'. But, even though
13718 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
13719 because there are two ways to unify base classes of S<0, 1, 2>
13720 with S<I, I, I>. If we kept the already deduced knowledge, we
13721 would reject the possibility I=1. */
13722 copy_of_targs = make_tree_vec (TREE_VEC_LENGTH (targs));
13724 /* If unification failed, we're done. */
13725 if (unify (tparms, copy_of_targs, CLASSTYPE_TI_ARGS (parm),
13726 CLASSTYPE_TI_ARGS (arg), UNIFY_ALLOW_NONE))
13732 /* Given a template type PARM and a class type ARG, find the unique
13733 base type in ARG that is an instance of PARM. We do not examine
13734 ARG itself; only its base-classes. If there is not exactly one
13735 appropriate base class, return NULL_TREE. PARM may be the type of
13736 a partial specialization, as well as a plain template type. Used
13740 get_template_base (tree tparms, tree targs, tree parm, tree arg)
13742 tree rval = NULL_TREE;
13745 gcc_assert (RECORD_OR_UNION_CODE_P (TREE_CODE (arg)));
13747 binfo = TYPE_BINFO (complete_type (arg));
13749 /* The type could not be completed. */
13752 /* Walk in inheritance graph order. The search order is not
13753 important, and this avoids multiple walks of virtual bases. */
13754 for (binfo = TREE_CHAIN (binfo); binfo; binfo = TREE_CHAIN (binfo))
13756 tree r = try_class_unification (tparms, targs, parm, BINFO_TYPE (binfo));
13760 /* If there is more than one satisfactory baseclass, then:
13764 If they yield more than one possible deduced A, the type
13768 if (rval && !same_type_p (r, rval))
13778 /* Returns the level of DECL, which declares a template parameter. */
13781 template_decl_level (tree decl)
13783 switch (TREE_CODE (decl))
13786 case TEMPLATE_DECL:
13787 return TEMPLATE_TYPE_LEVEL (TREE_TYPE (decl));
13790 return TEMPLATE_PARM_LEVEL (DECL_INITIAL (decl));
13793 gcc_unreachable ();
13798 /* Decide whether ARG can be unified with PARM, considering only the
13799 cv-qualifiers of each type, given STRICT as documented for unify.
13800 Returns nonzero iff the unification is OK on that basis. */
13803 check_cv_quals_for_unify (int strict, tree arg, tree parm)
13805 int arg_quals = cp_type_quals (arg);
13806 int parm_quals = cp_type_quals (parm);
13808 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
13809 && !(strict & UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
13811 /* Although a CVR qualifier is ignored when being applied to a
13812 substituted template parameter ([8.3.2]/1 for example), that
13813 does not apply during deduction [14.8.2.4]/1, (even though
13814 that is not explicitly mentioned, [14.8.2.4]/9 indicates
13815 this). Except when we're allowing additional CV qualifiers
13816 at the outer level [14.8.2.1]/3,1st bullet. */
13817 if ((TREE_CODE (arg) == REFERENCE_TYPE
13818 || TREE_CODE (arg) == FUNCTION_TYPE
13819 || TREE_CODE (arg) == METHOD_TYPE)
13820 && (parm_quals & (TYPE_QUAL_CONST | TYPE_QUAL_VOLATILE)))
13823 if ((!POINTER_TYPE_P (arg) && TREE_CODE (arg) != TEMPLATE_TYPE_PARM)
13824 && (parm_quals & TYPE_QUAL_RESTRICT))
13828 if (!(strict & (UNIFY_ALLOW_MORE_CV_QUAL | UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
13829 && (arg_quals & parm_quals) != parm_quals)
13832 if (!(strict & (UNIFY_ALLOW_LESS_CV_QUAL | UNIFY_ALLOW_OUTER_LESS_CV_QUAL))
13833 && (parm_quals & arg_quals) != arg_quals)
13839 /* Determines the LEVEL and INDEX for the template parameter PARM. */
13841 template_parm_level_and_index (tree parm, int* level, int* index)
13843 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
13844 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
13845 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
13847 *index = TEMPLATE_TYPE_IDX (parm);
13848 *level = TEMPLATE_TYPE_LEVEL (parm);
13852 *index = TEMPLATE_PARM_IDX (parm);
13853 *level = TEMPLATE_PARM_LEVEL (parm);
13857 /* Unifies the remaining arguments in PACKED_ARGS with the pack
13858 expansion at the end of PACKED_PARMS. Returns 0 if the type
13859 deduction succeeds, 1 otherwise. STRICT is the same as in
13860 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
13861 call argument list. We'll need to adjust the arguments to make them
13862 types. SUBR tells us if this is from a recursive call to
13863 type_unification_real. */
13865 unify_pack_expansion (tree tparms, tree targs, tree packed_parms,
13866 tree packed_args, int strict, bool call_args_p,
13870 = TREE_VEC_ELT (packed_parms, TREE_VEC_LENGTH (packed_parms) - 1);
13871 tree pattern = PACK_EXPANSION_PATTERN (parm);
13872 tree pack, packs = NULL_TREE;
13873 int i, start = TREE_VEC_LENGTH (packed_parms) - 1;
13874 int len = TREE_VEC_LENGTH (packed_args);
13876 /* Determine the parameter packs we will be deducing from the
13877 pattern, and record their current deductions. */
13878 for (pack = PACK_EXPANSION_PARAMETER_PACKS (parm);
13879 pack; pack = TREE_CHAIN (pack))
13881 tree parm_pack = TREE_VALUE (pack);
13884 /* Determine the index and level of this parameter pack. */
13885 template_parm_level_and_index (parm_pack, &level, &idx);
13887 /* Keep track of the parameter packs and their corresponding
13889 packs = tree_cons (parm_pack, TMPL_ARG (targs, level, idx), packs);
13890 TREE_TYPE (packs) = make_tree_vec (len - start);
13893 /* Loop through all of the arguments that have not yet been
13894 unified and unify each with the pattern. */
13895 for (i = start; i < len; i++)
13897 tree parm = pattern;
13899 /* For each parameter pack, clear out the deduced value so that
13900 we can deduce it again. */
13901 for (pack = packs; pack; pack = TREE_CHAIN (pack))
13904 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
13906 TMPL_ARG (targs, level, idx) = NULL_TREE;
13909 /* Unify the pattern with the current argument. */
13911 tree arg = TREE_VEC_ELT (packed_args, i);
13912 tree arg_expr = NULL_TREE;
13913 int arg_strict = strict;
13914 bool skip_arg_p = false;
13920 /* This mirrors what we do in type_unification_real. */
13924 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL
13925 | UNIFY_ALLOW_MORE_CV_QUAL
13926 | UNIFY_ALLOW_DERIVED);
13930 sub_strict = UNIFY_ALLOW_LESS_CV_QUAL;
13934 sub_strict = UNIFY_ALLOW_NONE;
13938 gcc_unreachable ();
13943 gcc_assert (TREE_TYPE (arg) != NULL_TREE);
13944 if (type_unknown_p (arg))
13946 /* [temp.deduct.type] A template-argument can be
13947 deduced from a pointer to function or pointer
13948 to member function argument if the set of
13949 overloaded functions does not contain function
13950 templates and at most one of a set of
13951 overloaded functions provides a unique
13954 if (resolve_overloaded_unification
13955 (tparms, targs, parm, arg,
13956 (unification_kind_t) strict,
13966 arg = unlowered_expr_type (arg);
13967 if (arg == error_mark_node)
13972 arg_strict = sub_strict;
13976 maybe_adjust_types_for_deduction ((unification_kind_t) strict,
13977 &parm, &arg, arg_expr);
13982 if (unify (tparms, targs, parm, arg, arg_strict))
13987 /* For each parameter pack, collect the deduced value. */
13988 for (pack = packs; pack; pack = TREE_CHAIN (pack))
13991 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
13993 TREE_VEC_ELT (TREE_TYPE (pack), i - start) =
13994 TMPL_ARG (targs, level, idx);
13998 /* Verify that the results of unification with the parameter packs
13999 produce results consistent with what we've seen before, and make
14000 the deduced argument packs available. */
14001 for (pack = packs; pack; pack = TREE_CHAIN (pack))
14003 tree old_pack = TREE_VALUE (pack);
14004 tree new_args = TREE_TYPE (pack);
14005 int i, len = TREE_VEC_LENGTH (new_args);
14006 bool nondeduced_p = false;
14008 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
14009 actually deduce anything. */
14010 for (i = 0; i < len && !nondeduced_p; ++i)
14011 if (TREE_VEC_ELT (new_args, i) == NULL_TREE)
14012 nondeduced_p = true;
14016 if (old_pack && ARGUMENT_PACK_INCOMPLETE_P (old_pack))
14018 /* Prepend the explicit arguments onto NEW_ARGS. */
14019 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
14020 tree old_args = new_args;
14021 int i, explicit_len = TREE_VEC_LENGTH (explicit_args);
14022 int len = explicit_len + TREE_VEC_LENGTH (old_args);
14024 /* Copy the explicit arguments. */
14025 new_args = make_tree_vec (len);
14026 for (i = 0; i < explicit_len; i++)
14027 TREE_VEC_ELT (new_args, i) = TREE_VEC_ELT (explicit_args, i);
14029 /* Copy the deduced arguments. */
14030 for (; i < len; i++)
14031 TREE_VEC_ELT (new_args, i) =
14032 TREE_VEC_ELT (old_args, i - explicit_len);
14040 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
14042 /* Build the deduced *_ARGUMENT_PACK. */
14043 if (TREE_CODE (TREE_PURPOSE (pack)) == TEMPLATE_PARM_INDEX)
14045 result = make_node (NONTYPE_ARGUMENT_PACK);
14046 TREE_TYPE (result) =
14047 TREE_TYPE (TEMPLATE_PARM_DECL (TREE_PURPOSE (pack)));
14048 TREE_CONSTANT (result) = 1;
14051 result = cxx_make_type (TYPE_ARGUMENT_PACK);
14053 SET_ARGUMENT_PACK_ARGS (result, new_args);
14055 /* Note the deduced argument packs for this parameter
14057 TMPL_ARG (targs, level, idx) = result;
14059 else if (ARGUMENT_PACK_INCOMPLETE_P (old_pack)
14060 && (ARGUMENT_PACK_ARGS (old_pack)
14061 == ARGUMENT_PACK_EXPLICIT_ARGS (old_pack)))
14063 /* We only had the explicitly-provided arguments before, but
14064 now we have a complete set of arguments. */
14066 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
14067 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
14069 /* Keep the original deduced argument pack. */
14070 TMPL_ARG (targs, level, idx) = old_pack;
14072 SET_ARGUMENT_PACK_ARGS (old_pack, new_args);
14073 ARGUMENT_PACK_INCOMPLETE_P (old_pack) = 1;
14074 ARGUMENT_PACK_EXPLICIT_ARGS (old_pack) = explicit_args;
14076 else if (!comp_template_args (ARGUMENT_PACK_ARGS (old_pack),
14078 /* Inconsistent unification of this parameter pack. */
14084 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
14086 /* Keep the original deduced argument pack. */
14087 TMPL_ARG (targs, level, idx) = old_pack;
14094 /* Deduce the value of template parameters. TPARMS is the (innermost)
14095 set of template parameters to a template. TARGS is the bindings
14096 for those template parameters, as determined thus far; TARGS may
14097 include template arguments for outer levels of template parameters
14098 as well. PARM is a parameter to a template function, or a
14099 subcomponent of that parameter; ARG is the corresponding argument.
14100 This function attempts to match PARM with ARG in a manner
14101 consistent with the existing assignments in TARGS. If more values
14102 are deduced, then TARGS is updated.
14104 Returns 0 if the type deduction succeeds, 1 otherwise. The
14105 parameter STRICT is a bitwise or of the following flags:
14108 Require an exact match between PARM and ARG.
14109 UNIFY_ALLOW_MORE_CV_QUAL:
14110 Allow the deduced ARG to be more cv-qualified (by qualification
14111 conversion) than ARG.
14112 UNIFY_ALLOW_LESS_CV_QUAL:
14113 Allow the deduced ARG to be less cv-qualified than ARG.
14114 UNIFY_ALLOW_DERIVED:
14115 Allow the deduced ARG to be a template base class of ARG,
14116 or a pointer to a template base class of the type pointed to by
14118 UNIFY_ALLOW_INTEGER:
14119 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
14120 case for more information.
14121 UNIFY_ALLOW_OUTER_LEVEL:
14122 This is the outermost level of a deduction. Used to determine validity
14123 of qualification conversions. A valid qualification conversion must
14124 have const qualified pointers leading up to the inner type which
14125 requires additional CV quals, except at the outer level, where const
14126 is not required [conv.qual]. It would be normal to set this flag in
14127 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
14128 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
14129 This is the outermost level of a deduction, and PARM can be more CV
14130 qualified at this point.
14131 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
14132 This is the outermost level of a deduction, and PARM can be less CV
14133 qualified at this point. */
14136 unify (tree tparms, tree targs, tree parm, tree arg, int strict)
14141 int strict_in = strict;
14143 /* I don't think this will do the right thing with respect to types.
14144 But the only case I've seen it in so far has been array bounds, where
14145 signedness is the only information lost, and I think that will be
14147 while (TREE_CODE (parm) == NOP_EXPR)
14148 parm = TREE_OPERAND (parm, 0);
14150 if (arg == error_mark_node)
14152 if (arg == unknown_type_node
14153 || arg == init_list_type_node)
14154 /* We can't deduce anything from this, but we might get all the
14155 template args from other function args. */
14158 /* If PARM uses template parameters, then we can't bail out here,
14159 even if ARG == PARM, since we won't record unifications for the
14160 template parameters. We might need them if we're trying to
14161 figure out which of two things is more specialized. */
14162 if (arg == parm && !uses_template_parms (parm))
14165 /* Handle init lists early, so the rest of the function can assume
14166 we're dealing with a type. */
14167 if (BRACE_ENCLOSED_INITIALIZER_P (arg))
14171 tree orig_parm = parm;
14173 /* Replace T with std::initializer_list<T> for deduction. */
14174 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
14175 && flag_deduce_init_list)
14176 parm = listify (parm);
14178 if (!is_std_init_list (parm))
14179 /* We can only deduce from an initializer list argument if the
14180 parameter is std::initializer_list; otherwise this is a
14181 non-deduced context. */
14184 elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (parm), 0);
14186 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg), i, elt)
14188 int elt_strict = strict;
14189 if (!BRACE_ENCLOSED_INITIALIZER_P (elt))
14191 tree type = TREE_TYPE (elt);
14192 /* It should only be possible to get here for a call. */
14193 gcc_assert (elt_strict & UNIFY_ALLOW_OUTER_LEVEL);
14194 elt_strict |= maybe_adjust_types_for_deduction
14195 (DEDUCE_CALL, &elttype, &type, elt);
14199 if (unify (tparms, targs, elttype, elt, elt_strict))
14203 /* If the std::initializer_list<T> deduction worked, replace the
14204 deduced A with std::initializer_list<A>. */
14205 if (orig_parm != parm)
14207 idx = TEMPLATE_TYPE_IDX (orig_parm);
14208 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
14209 targ = listify (targ);
14210 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = targ;
14215 /* Immediately reject some pairs that won't unify because of
14216 cv-qualification mismatches. */
14217 if (TREE_CODE (arg) == TREE_CODE (parm)
14219 /* It is the elements of the array which hold the cv quals of an array
14220 type, and the elements might be template type parms. We'll check
14221 when we recurse. */
14222 && TREE_CODE (arg) != ARRAY_TYPE
14223 /* We check the cv-qualifiers when unifying with template type
14224 parameters below. We want to allow ARG `const T' to unify with
14225 PARM `T' for example, when computing which of two templates
14226 is more specialized, for example. */
14227 && TREE_CODE (arg) != TEMPLATE_TYPE_PARM
14228 && !check_cv_quals_for_unify (strict_in, arg, parm))
14231 if (!(strict & UNIFY_ALLOW_OUTER_LEVEL)
14232 && TYPE_P (parm) && !CP_TYPE_CONST_P (parm))
14233 strict &= ~UNIFY_ALLOW_MORE_CV_QUAL;
14234 strict &= ~UNIFY_ALLOW_OUTER_LEVEL;
14235 strict &= ~UNIFY_ALLOW_DERIVED;
14236 strict &= ~UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
14237 strict &= ~UNIFY_ALLOW_OUTER_LESS_CV_QUAL;
14239 switch (TREE_CODE (parm))
14241 case TYPENAME_TYPE:
14243 case UNBOUND_CLASS_TEMPLATE:
14244 /* In a type which contains a nested-name-specifier, template
14245 argument values cannot be deduced for template parameters used
14246 within the nested-name-specifier. */
14249 case TEMPLATE_TYPE_PARM:
14250 case TEMPLATE_TEMPLATE_PARM:
14251 case BOUND_TEMPLATE_TEMPLATE_PARM:
14252 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
14253 if (tparm == error_mark_node)
14256 if (TEMPLATE_TYPE_LEVEL (parm)
14257 != template_decl_level (tparm))
14258 /* The PARM is not one we're trying to unify. Just check
14259 to see if it matches ARG. */
14260 return (TREE_CODE (arg) == TREE_CODE (parm)
14261 && same_type_p (parm, arg)) ? 0 : 1;
14262 idx = TEMPLATE_TYPE_IDX (parm);
14263 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
14264 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, idx));
14266 /* Check for mixed types and values. */
14267 if ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
14268 && TREE_CODE (tparm) != TYPE_DECL)
14269 || (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
14270 && TREE_CODE (tparm) != TEMPLATE_DECL))
14273 if (TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
14275 /* ARG must be constructed from a template class or a template
14276 template parameter. */
14277 if (TREE_CODE (arg) != BOUND_TEMPLATE_TEMPLATE_PARM
14278 && !CLASSTYPE_SPECIALIZATION_OF_PRIMARY_TEMPLATE_P (arg))
14282 tree parmvec = TYPE_TI_ARGS (parm);
14283 tree argvec = INNERMOST_TEMPLATE_ARGS (TYPE_TI_ARGS (arg));
14285 = DECL_INNERMOST_TEMPLATE_PARMS
14286 (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (parm));
14288 int parm_variadic_p = 0;
14290 /* The resolution to DR150 makes clear that default
14291 arguments for an N-argument may not be used to bind T
14292 to a template template parameter with fewer than N
14293 parameters. It is not safe to permit the binding of
14294 default arguments as an extension, as that may change
14295 the meaning of a conforming program. Consider:
14297 struct Dense { static const unsigned int dim = 1; };
14299 template <template <typename> class View,
14301 void operator+(float, View<Block> const&);
14303 template <typename Block,
14304 unsigned int Dim = Block::dim>
14305 struct Lvalue_proxy { operator float() const; };
14309 Lvalue_proxy<Dense> p;
14314 Here, if Lvalue_proxy is permitted to bind to View, then
14315 the global operator+ will be used; if they are not, the
14316 Lvalue_proxy will be converted to float. */
14317 if (coerce_template_parms (parm_parms,
14319 TYPE_TI_TEMPLATE (parm),
14321 /*require_all_args=*/true,
14322 /*use_default_args=*/false)
14323 == error_mark_node)
14326 /* Deduce arguments T, i from TT<T> or TT<i>.
14327 We check each element of PARMVEC and ARGVEC individually
14328 rather than the whole TREE_VEC since they can have
14329 different number of elements. */
14331 parmvec = expand_template_argument_pack (parmvec);
14332 argvec = expand_template_argument_pack (argvec);
14334 len = TREE_VEC_LENGTH (parmvec);
14336 /* Check if the parameters end in a pack, making them
14339 && PACK_EXPANSION_P (TREE_VEC_ELT (parmvec, len - 1)))
14340 parm_variadic_p = 1;
14342 if (TREE_VEC_LENGTH (argvec) < len - parm_variadic_p)
14345 for (i = 0; i < len - parm_variadic_p; ++i)
14347 if (unify (tparms, targs,
14348 TREE_VEC_ELT (parmvec, i),
14349 TREE_VEC_ELT (argvec, i),
14354 if (parm_variadic_p
14355 && unify_pack_expansion (tparms, targs,
14358 /*call_args_p=*/false,
14362 arg = TYPE_TI_TEMPLATE (arg);
14364 /* Fall through to deduce template name. */
14367 if (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
14368 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
14370 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
14372 /* Simple cases: Value already set, does match or doesn't. */
14373 if (targ != NULL_TREE && template_args_equal (targ, arg))
14380 /* If PARM is `const T' and ARG is only `int', we don't have
14381 a match unless we are allowing additional qualification.
14382 If ARG is `const int' and PARM is just `T' that's OK;
14383 that binds `const int' to `T'. */
14384 if (!check_cv_quals_for_unify (strict_in | UNIFY_ALLOW_LESS_CV_QUAL,
14388 /* Consider the case where ARG is `const volatile int' and
14389 PARM is `const T'. Then, T should be `volatile int'. */
14390 arg = cp_build_qualified_type_real
14391 (arg, cp_type_quals (arg) & ~cp_type_quals (parm), tf_none);
14392 if (arg == error_mark_node)
14395 /* Simple cases: Value already set, does match or doesn't. */
14396 if (targ != NULL_TREE && same_type_p (targ, arg))
14401 /* Make sure that ARG is not a variable-sized array. (Note
14402 that were talking about variable-sized arrays (like
14403 `int[n]'), rather than arrays of unknown size (like
14404 `int[]').) We'll get very confused by such a type since
14405 the bound of the array will not be computable in an
14406 instantiation. Besides, such types are not allowed in
14407 ISO C++, so we can do as we please here. */
14408 if (variably_modified_type_p (arg, NULL_TREE))
14411 /* Strip typedefs as in convert_template_argument. */
14412 arg = strip_typedefs (arg);
14415 /* If ARG is a parameter pack or an expansion, we cannot unify
14416 against it unless PARM is also a parameter pack. */
14417 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
14418 && !template_parameter_pack_p (parm))
14421 /* If the argument deduction results is a METHOD_TYPE,
14422 then there is a problem.
14423 METHOD_TYPE doesn't map to any real C++ type the result of
14424 the deduction can not be of that type. */
14425 if (TREE_CODE (arg) == METHOD_TYPE)
14428 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
14431 case TEMPLATE_PARM_INDEX:
14432 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
14433 if (tparm == error_mark_node)
14436 if (TEMPLATE_PARM_LEVEL (parm)
14437 != template_decl_level (tparm))
14438 /* The PARM is not one we're trying to unify. Just check
14439 to see if it matches ARG. */
14440 return !(TREE_CODE (arg) == TREE_CODE (parm)
14441 && cp_tree_equal (parm, arg));
14443 idx = TEMPLATE_PARM_IDX (parm);
14444 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
14447 return !cp_tree_equal (targ, arg);
14449 /* [temp.deduct.type] If, in the declaration of a function template
14450 with a non-type template-parameter, the non-type
14451 template-parameter is used in an expression in the function
14452 parameter-list and, if the corresponding template-argument is
14453 deduced, the template-argument type shall match the type of the
14454 template-parameter exactly, except that a template-argument
14455 deduced from an array bound may be of any integral type.
14456 The non-type parameter might use already deduced type parameters. */
14457 tparm = tsubst (TREE_TYPE (parm), targs, 0, NULL_TREE);
14458 if (!TREE_TYPE (arg))
14459 /* Template-parameter dependent expression. Just accept it for now.
14460 It will later be processed in convert_template_argument. */
14462 else if (same_type_p (TREE_TYPE (arg), tparm))
14464 else if ((strict & UNIFY_ALLOW_INTEGER)
14465 && (TREE_CODE (tparm) == INTEGER_TYPE
14466 || TREE_CODE (tparm) == BOOLEAN_TYPE))
14467 /* Convert the ARG to the type of PARM; the deduced non-type
14468 template argument must exactly match the types of the
14469 corresponding parameter. */
14470 arg = fold (build_nop (tparm, arg));
14471 else if (uses_template_parms (tparm))
14472 /* We haven't deduced the type of this parameter yet. Try again
14478 /* If ARG is a parameter pack or an expansion, we cannot unify
14479 against it unless PARM is also a parameter pack. */
14480 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
14481 && !TEMPLATE_PARM_PARAMETER_PACK (parm))
14484 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
14489 /* A pointer-to-member constant can be unified only with
14490 another constant. */
14491 if (TREE_CODE (arg) != PTRMEM_CST)
14494 /* Just unify the class member. It would be useless (and possibly
14495 wrong, depending on the strict flags) to unify also
14496 PTRMEM_CST_CLASS, because we want to be sure that both parm and
14497 arg refer to the same variable, even if through different
14498 classes. For instance:
14500 struct A { int x; };
14503 Unification of &A::x and &B::x must succeed. */
14504 return unify (tparms, targs, PTRMEM_CST_MEMBER (parm),
14505 PTRMEM_CST_MEMBER (arg), strict);
14510 if (TREE_CODE (arg) != POINTER_TYPE)
14513 /* [temp.deduct.call]
14515 A can be another pointer or pointer to member type that can
14516 be converted to the deduced A via a qualification
14517 conversion (_conv.qual_).
14519 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
14520 This will allow for additional cv-qualification of the
14521 pointed-to types if appropriate. */
14523 if (TREE_CODE (TREE_TYPE (arg)) == RECORD_TYPE)
14524 /* The derived-to-base conversion only persists through one
14525 level of pointers. */
14526 strict |= (strict_in & UNIFY_ALLOW_DERIVED);
14528 return unify (tparms, targs, TREE_TYPE (parm),
14529 TREE_TYPE (arg), strict);
14532 case REFERENCE_TYPE:
14533 if (TREE_CODE (arg) != REFERENCE_TYPE)
14535 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
14536 strict & UNIFY_ALLOW_MORE_CV_QUAL);
14539 if (TREE_CODE (arg) != ARRAY_TYPE)
14541 if ((TYPE_DOMAIN (parm) == NULL_TREE)
14542 != (TYPE_DOMAIN (arg) == NULL_TREE))
14544 if (TYPE_DOMAIN (parm) != NULL_TREE)
14551 /* Our representation of array types uses "N - 1" as the
14552 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
14553 not an integer constant. We cannot unify arbitrarily
14554 complex expressions, so we eliminate the MINUS_EXPRs
14556 parm_max = TYPE_MAX_VALUE (TYPE_DOMAIN (parm));
14557 parm_cst = TREE_CODE (parm_max) == INTEGER_CST;
14560 gcc_assert (TREE_CODE (parm_max) == MINUS_EXPR);
14561 parm_max = TREE_OPERAND (parm_max, 0);
14563 arg_max = TYPE_MAX_VALUE (TYPE_DOMAIN (arg));
14564 arg_cst = TREE_CODE (arg_max) == INTEGER_CST;
14567 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
14568 trying to unify the type of a variable with the type
14569 of a template parameter. For example:
14571 template <unsigned int N>
14572 void f (char (&) [N]);
14579 Here, the type of the ARG will be "int [g(i)]", and
14580 may be a SAVE_EXPR, etc. */
14581 if (TREE_CODE (arg_max) != MINUS_EXPR)
14583 arg_max = TREE_OPERAND (arg_max, 0);
14586 /* If only one of the bounds used a MINUS_EXPR, compensate
14587 by adding one to the other bound. */
14588 if (parm_cst && !arg_cst)
14589 parm_max = fold_build2_loc (input_location, PLUS_EXPR,
14593 else if (arg_cst && !parm_cst)
14594 arg_max = fold_build2_loc (input_location, PLUS_EXPR,
14599 if (unify (tparms, targs, parm_max, arg_max, UNIFY_ALLOW_INTEGER))
14602 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
14603 strict & UNIFY_ALLOW_MORE_CV_QUAL);
14610 case ENUMERAL_TYPE:
14612 if (TREE_CODE (arg) != TREE_CODE (parm))
14615 /* We have already checked cv-qualification at the top of the
14617 if (!same_type_ignoring_top_level_qualifiers_p (arg, parm))
14620 /* As far as unification is concerned, this wins. Later checks
14621 will invalidate it if necessary. */
14624 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
14625 /* Type INTEGER_CST can come from ordinary constant template args. */
14627 while (TREE_CODE (arg) == NOP_EXPR)
14628 arg = TREE_OPERAND (arg, 0);
14630 if (TREE_CODE (arg) != INTEGER_CST)
14632 return !tree_int_cst_equal (parm, arg);
14637 if (TREE_CODE (arg) != TREE_VEC)
14639 if (TREE_VEC_LENGTH (parm) != TREE_VEC_LENGTH (arg))
14641 for (i = 0; i < TREE_VEC_LENGTH (parm); ++i)
14642 if (unify (tparms, targs,
14643 TREE_VEC_ELT (parm, i), TREE_VEC_ELT (arg, i),
14651 if (TREE_CODE (arg) != TREE_CODE (parm))
14654 if (TYPE_PTRMEMFUNC_P (parm))
14656 if (!TYPE_PTRMEMFUNC_P (arg))
14659 return unify (tparms, targs,
14660 TYPE_PTRMEMFUNC_FN_TYPE (parm),
14661 TYPE_PTRMEMFUNC_FN_TYPE (arg),
14665 if (CLASSTYPE_TEMPLATE_INFO (parm))
14667 tree t = NULL_TREE;
14669 if (strict_in & UNIFY_ALLOW_DERIVED)
14671 /* First, we try to unify the PARM and ARG directly. */
14672 t = try_class_unification (tparms, targs,
14677 /* Fallback to the special case allowed in
14678 [temp.deduct.call]:
14680 If P is a class, and P has the form
14681 template-id, then A can be a derived class of
14682 the deduced A. Likewise, if P is a pointer to
14683 a class of the form template-id, A can be a
14684 pointer to a derived class pointed to by the
14686 t = get_template_base (tparms, targs, parm, arg);
14692 else if (CLASSTYPE_TEMPLATE_INFO (arg)
14693 && (CLASSTYPE_TI_TEMPLATE (parm)
14694 == CLASSTYPE_TI_TEMPLATE (arg)))
14695 /* Perhaps PARM is something like S<U> and ARG is S<int>.
14696 Then, we should unify `int' and `U'. */
14699 /* There's no chance of unification succeeding. */
14702 return unify (tparms, targs, CLASSTYPE_TI_ARGS (parm),
14703 CLASSTYPE_TI_ARGS (t), UNIFY_ALLOW_NONE);
14705 else if (!same_type_ignoring_top_level_qualifiers_p (parm, arg))
14710 case FUNCTION_TYPE:
14712 unsigned int nargs;
14717 if (TREE_CODE (arg) != TREE_CODE (parm))
14720 /* CV qualifications for methods can never be deduced, they must
14721 match exactly. We need to check them explicitly here,
14722 because type_unification_real treats them as any other
14723 cv-qualified parameter. */
14724 if (TREE_CODE (parm) == METHOD_TYPE
14725 && (!check_cv_quals_for_unify
14727 TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (arg))),
14728 TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (parm))))))
14731 if (unify (tparms, targs, TREE_TYPE (parm),
14732 TREE_TYPE (arg), UNIFY_ALLOW_NONE))
14735 nargs = list_length (TYPE_ARG_TYPES (arg));
14736 args = XALLOCAVEC (tree, nargs);
14737 for (a = TYPE_ARG_TYPES (arg), i = 0;
14738 a != NULL_TREE && a != void_list_node;
14739 a = TREE_CHAIN (a), ++i)
14740 args[i] = TREE_VALUE (a);
14743 return type_unification_real (tparms, targs, TYPE_ARG_TYPES (parm),
14744 args, nargs, 1, DEDUCE_EXACT,
14749 /* Unify a pointer to member with a pointer to member function, which
14750 deduces the type of the member as a function type. */
14751 if (TYPE_PTRMEMFUNC_P (arg))
14755 cp_cv_quals cv_quals;
14757 /* Check top-level cv qualifiers */
14758 if (!check_cv_quals_for_unify (UNIFY_ALLOW_NONE, arg, parm))
14761 if (unify (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
14762 TYPE_PTRMEMFUNC_OBJECT_TYPE (arg), UNIFY_ALLOW_NONE))
14765 /* Determine the type of the function we are unifying against. */
14766 method_type = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (arg));
14768 build_function_type (TREE_TYPE (method_type),
14769 TREE_CHAIN (TYPE_ARG_TYPES (method_type)));
14771 /* Extract the cv-qualifiers of the member function from the
14772 implicit object parameter and place them on the function
14773 type to be restored later. */
14775 cp_type_quals(TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (method_type))));
14776 fntype = build_qualified_type (fntype, cv_quals);
14777 return unify (tparms, targs, TREE_TYPE (parm), fntype, strict);
14780 if (TREE_CODE (arg) != OFFSET_TYPE)
14782 if (unify (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
14783 TYPE_OFFSET_BASETYPE (arg), UNIFY_ALLOW_NONE))
14785 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
14789 if (DECL_TEMPLATE_PARM_P (parm))
14790 return unify (tparms, targs, DECL_INITIAL (parm), arg, strict);
14791 if (arg != integral_constant_value (parm))
14796 case TEMPLATE_DECL:
14797 /* Matched cases are handled by the ARG == PARM test above. */
14800 case TYPE_ARGUMENT_PACK:
14801 case NONTYPE_ARGUMENT_PACK:
14803 tree packed_parms = ARGUMENT_PACK_ARGS (parm);
14804 tree packed_args = ARGUMENT_PACK_ARGS (arg);
14805 int i, len = TREE_VEC_LENGTH (packed_parms);
14806 int argslen = TREE_VEC_LENGTH (packed_args);
14807 int parm_variadic_p = 0;
14809 for (i = 0; i < len; ++i)
14811 if (PACK_EXPANSION_P (TREE_VEC_ELT (packed_parms, i)))
14814 /* We can unify against something with a trailing
14816 parm_variadic_p = 1;
14818 /* Since there is something following the pack
14819 expansion, we cannot unify this template argument
14826 /* If we don't have enough arguments to satisfy the parameters
14827 (not counting the pack expression at the end), or we have
14828 too many arguments for a parameter list that doesn't end in
14829 a pack expression, we can't unify. */
14830 if (argslen < (len - parm_variadic_p)
14831 || (argslen > len && !parm_variadic_p))
14834 /* Unify all of the parameters that precede the (optional)
14835 pack expression. */
14836 for (i = 0; i < len - parm_variadic_p; ++i)
14838 if (unify (tparms, targs, TREE_VEC_ELT (packed_parms, i),
14839 TREE_VEC_ELT (packed_args, i), strict))
14843 if (parm_variadic_p)
14844 return unify_pack_expansion (tparms, targs,
14845 packed_parms, packed_args,
14846 strict, /*call_args_p=*/false,
14854 case DECLTYPE_TYPE:
14855 /* Cannot deduce anything from TYPEOF_TYPE or DECLTYPE_TYPE
14860 /* Unification fails if we hit an error node. */
14864 gcc_assert (EXPR_P (parm));
14866 /* We must be looking at an expression. This can happen with
14870 void foo(S<I>, S<I + 2>);
14872 This is a "nondeduced context":
14876 The nondeduced contexts are:
14878 --A type that is a template-id in which one or more of
14879 the template-arguments is an expression that references
14880 a template-parameter.
14882 In these cases, we assume deduction succeeded, but don't
14883 actually infer any unifications. */
14885 if (!uses_template_parms (parm)
14886 && !template_args_equal (parm, arg))
14893 /* Note that DECL can be defined in this translation unit, if
14897 mark_definable (tree decl)
14900 DECL_NOT_REALLY_EXTERN (decl) = 1;
14901 FOR_EACH_CLONE (clone, decl)
14902 DECL_NOT_REALLY_EXTERN (clone) = 1;
14905 /* Called if RESULT is explicitly instantiated, or is a member of an
14906 explicitly instantiated class. */
14909 mark_decl_instantiated (tree result, int extern_p)
14911 SET_DECL_EXPLICIT_INSTANTIATION (result);
14913 /* If this entity has already been written out, it's too late to
14914 make any modifications. */
14915 if (TREE_ASM_WRITTEN (result))
14918 if (TREE_CODE (result) != FUNCTION_DECL)
14919 /* The TREE_PUBLIC flag for function declarations will have been
14920 set correctly by tsubst. */
14921 TREE_PUBLIC (result) = 1;
14923 /* This might have been set by an earlier implicit instantiation. */
14924 DECL_COMDAT (result) = 0;
14927 DECL_NOT_REALLY_EXTERN (result) = 0;
14930 mark_definable (result);
14931 /* Always make artificials weak. */
14932 if (DECL_ARTIFICIAL (result) && flag_weak)
14933 comdat_linkage (result);
14934 /* For WIN32 we also want to put explicit instantiations in
14935 linkonce sections. */
14936 else if (TREE_PUBLIC (result))
14937 maybe_make_one_only (result);
14940 /* If EXTERN_P, then this function will not be emitted -- unless
14941 followed by an explicit instantiation, at which point its linkage
14942 will be adjusted. If !EXTERN_P, then this function will be
14943 emitted here. In neither circumstance do we want
14944 import_export_decl to adjust the linkage. */
14945 DECL_INTERFACE_KNOWN (result) = 1;
14948 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
14949 important template arguments. If any are missing, we check whether
14950 they're important by using error_mark_node for substituting into any
14951 args that were used for partial ordering (the ones between ARGS and END)
14952 and seeing if it bubbles up. */
14955 check_undeduced_parms (tree targs, tree args, tree end)
14957 bool found = false;
14959 for (i = TREE_VEC_LENGTH (targs) - 1; i >= 0; --i)
14960 if (TREE_VEC_ELT (targs, i) == NULL_TREE)
14963 TREE_VEC_ELT (targs, i) = error_mark_node;
14967 for (; args != end; args = TREE_CHAIN (args))
14969 tree substed = tsubst (TREE_VALUE (args), targs, tf_none, NULL_TREE);
14970 if (substed == error_mark_node)
14977 /* Given two function templates PAT1 and PAT2, return:
14979 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
14980 -1 if PAT2 is more specialized than PAT1.
14981 0 if neither is more specialized.
14983 LEN indicates the number of parameters we should consider
14984 (defaulted parameters should not be considered).
14986 The 1998 std underspecified function template partial ordering, and
14987 DR214 addresses the issue. We take pairs of arguments, one from
14988 each of the templates, and deduce them against each other. One of
14989 the templates will be more specialized if all the *other*
14990 template's arguments deduce against its arguments and at least one
14991 of its arguments *does* *not* deduce against the other template's
14992 corresponding argument. Deduction is done as for class templates.
14993 The arguments used in deduction have reference and top level cv
14994 qualifiers removed. Iff both arguments were originally reference
14995 types *and* deduction succeeds in both directions, the template
14996 with the more cv-qualified argument wins for that pairing (if
14997 neither is more cv-qualified, they both are equal). Unlike regular
14998 deduction, after all the arguments have been deduced in this way,
14999 we do *not* verify the deduced template argument values can be
15000 substituted into non-deduced contexts.
15002 The logic can be a bit confusing here, because we look at deduce1 and
15003 targs1 to see if pat2 is at least as specialized, and vice versa; if we
15004 can find template arguments for pat1 to make arg1 look like arg2, that
15005 means that arg2 is at least as specialized as arg1. */
15008 more_specialized_fn (tree pat1, tree pat2, int len)
15010 tree decl1 = DECL_TEMPLATE_RESULT (pat1);
15011 tree decl2 = DECL_TEMPLATE_RESULT (pat2);
15012 tree targs1 = make_tree_vec (DECL_NTPARMS (pat1));
15013 tree targs2 = make_tree_vec (DECL_NTPARMS (pat2));
15014 tree tparms1 = DECL_INNERMOST_TEMPLATE_PARMS (pat1);
15015 tree tparms2 = DECL_INNERMOST_TEMPLATE_PARMS (pat2);
15016 tree args1 = TYPE_ARG_TYPES (TREE_TYPE (decl1));
15017 tree args2 = TYPE_ARG_TYPES (TREE_TYPE (decl2));
15018 tree origs1, origs2;
15019 bool lose1 = false;
15020 bool lose2 = false;
15022 /* Remove the this parameter from non-static member functions. If
15023 one is a non-static member function and the other is not a static
15024 member function, remove the first parameter from that function
15025 also. This situation occurs for operator functions where we
15026 locate both a member function (with this pointer) and non-member
15027 operator (with explicit first operand). */
15028 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl1))
15030 len--; /* LEN is the number of significant arguments for DECL1 */
15031 args1 = TREE_CHAIN (args1);
15032 if (!DECL_STATIC_FUNCTION_P (decl2))
15033 args2 = TREE_CHAIN (args2);
15035 else if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl2))
15037 args2 = TREE_CHAIN (args2);
15038 if (!DECL_STATIC_FUNCTION_P (decl1))
15041 args1 = TREE_CHAIN (args1);
15045 /* If only one is a conversion operator, they are unordered. */
15046 if (DECL_CONV_FN_P (decl1) != DECL_CONV_FN_P (decl2))
15049 /* Consider the return type for a conversion function */
15050 if (DECL_CONV_FN_P (decl1))
15052 args1 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl1)), args1);
15053 args2 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl2)), args2);
15057 processing_template_decl++;
15063 /* Stop when an ellipsis is seen. */
15064 && args1 != NULL_TREE && args2 != NULL_TREE)
15066 tree arg1 = TREE_VALUE (args1);
15067 tree arg2 = TREE_VALUE (args2);
15068 int deduce1, deduce2;
15072 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
15073 && TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
15075 /* When both arguments are pack expansions, we need only
15076 unify the patterns themselves. */
15077 arg1 = PACK_EXPANSION_PATTERN (arg1);
15078 arg2 = PACK_EXPANSION_PATTERN (arg2);
15080 /* This is the last comparison we need to do. */
15084 if (TREE_CODE (arg1) == REFERENCE_TYPE)
15086 arg1 = TREE_TYPE (arg1);
15087 quals1 = cp_type_quals (arg1);
15090 if (TREE_CODE (arg2) == REFERENCE_TYPE)
15092 arg2 = TREE_TYPE (arg2);
15093 quals2 = cp_type_quals (arg2);
15096 if ((quals1 < 0) != (quals2 < 0))
15098 /* Only of the args is a reference, see if we should apply
15099 array/function pointer decay to it. This is not part of
15100 DR214, but is, IMHO, consistent with the deduction rules
15101 for the function call itself, and with our earlier
15102 implementation of the underspecified partial ordering
15103 rules. (nathan). */
15106 switch (TREE_CODE (arg1))
15109 arg1 = TREE_TYPE (arg1);
15111 case FUNCTION_TYPE:
15112 arg1 = build_pointer_type (arg1);
15121 switch (TREE_CODE (arg2))
15124 arg2 = TREE_TYPE (arg2);
15126 case FUNCTION_TYPE:
15127 arg2 = build_pointer_type (arg2);
15136 arg1 = TYPE_MAIN_VARIANT (arg1);
15137 arg2 = TYPE_MAIN_VARIANT (arg2);
15139 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION)
15141 int i, len2 = list_length (args2);
15142 tree parmvec = make_tree_vec (1);
15143 tree argvec = make_tree_vec (len2);
15146 /* Setup the parameter vector, which contains only ARG1. */
15147 TREE_VEC_ELT (parmvec, 0) = arg1;
15149 /* Setup the argument vector, which contains the remaining
15151 for (i = 0; i < len2; i++, ta = TREE_CHAIN (ta))
15152 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
15154 deduce1 = !unify_pack_expansion (tparms1, targs1, parmvec,
15155 argvec, UNIFY_ALLOW_NONE,
15156 /*call_args_p=*/false,
15159 /* We cannot deduce in the other direction, because ARG1 is
15160 a pack expansion but ARG2 is not. */
15163 else if (TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
15165 int i, len1 = list_length (args1);
15166 tree parmvec = make_tree_vec (1);
15167 tree argvec = make_tree_vec (len1);
15170 /* Setup the parameter vector, which contains only ARG1. */
15171 TREE_VEC_ELT (parmvec, 0) = arg2;
15173 /* Setup the argument vector, which contains the remaining
15175 for (i = 0; i < len1; i++, ta = TREE_CHAIN (ta))
15176 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
15178 deduce2 = !unify_pack_expansion (tparms2, targs2, parmvec,
15179 argvec, UNIFY_ALLOW_NONE,
15180 /*call_args_p=*/false,
15183 /* We cannot deduce in the other direction, because ARG2 is
15184 a pack expansion but ARG1 is not.*/
15190 /* The normal case, where neither argument is a pack
15192 deduce1 = !unify (tparms1, targs1, arg1, arg2, UNIFY_ALLOW_NONE);
15193 deduce2 = !unify (tparms2, targs2, arg2, arg1, UNIFY_ALLOW_NONE);
15196 /* If we couldn't deduce arguments for tparms1 to make arg1 match
15197 arg2, then arg2 is not as specialized as arg1. */
15203 /* "If, for a given type, deduction succeeds in both directions
15204 (i.e., the types are identical after the transformations above)
15205 and if the type from the argument template is more cv-qualified
15206 than the type from the parameter template (as described above)
15207 that type is considered to be more specialized than the other. If
15208 neither type is more cv-qualified than the other then neither type
15209 is more specialized than the other."
15211 We check same_type_p explicitly because deduction can also succeed
15212 in both directions when there is a nondeduced context. */
15213 if (deduce1 && deduce2
15214 && quals1 != quals2 && quals1 >= 0 && quals2 >= 0
15215 && same_type_p (arg1, arg2))
15217 if ((quals1 & quals2) == quals2)
15219 if ((quals1 & quals2) == quals1)
15223 if (lose1 && lose2)
15224 /* We've failed to deduce something in either direction.
15225 These must be unordered. */
15228 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
15229 || TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
15230 /* We have already processed all of the arguments in our
15231 handing of the pack expansion type. */
15234 args1 = TREE_CHAIN (args1);
15235 args2 = TREE_CHAIN (args2);
15238 /* "In most cases, all template parameters must have values in order for
15239 deduction to succeed, but for partial ordering purposes a template
15240 parameter may remain without a value provided it is not used in the
15241 types being used for partial ordering."
15243 Thus, if we are missing any of the targs1 we need to substitute into
15244 origs1, then pat2 is not as specialized as pat1. This can happen when
15245 there is a nondeduced context. */
15246 if (!lose2 && check_undeduced_parms (targs1, origs1, args1))
15248 if (!lose1 && check_undeduced_parms (targs2, origs2, args2))
15251 processing_template_decl--;
15253 /* All things being equal, if the next argument is a pack expansion
15254 for one function but not for the other, prefer the
15255 non-variadic function. FIXME this is bogus; see c++/41958. */
15257 && args1 && TREE_VALUE (args1)
15258 && args2 && TREE_VALUE (args2))
15260 lose1 = TREE_CODE (TREE_VALUE (args1)) == TYPE_PACK_EXPANSION;
15261 lose2 = TREE_CODE (TREE_VALUE (args2)) == TYPE_PACK_EXPANSION;
15264 if (lose1 == lose2)
15272 /* Determine which of two partial specializations is more specialized.
15274 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
15275 to the first partial specialization. The TREE_VALUE is the
15276 innermost set of template parameters for the partial
15277 specialization. PAT2 is similar, but for the second template.
15279 Return 1 if the first partial specialization is more specialized;
15280 -1 if the second is more specialized; 0 if neither is more
15283 See [temp.class.order] for information about determining which of
15284 two templates is more specialized. */
15287 more_specialized_class (tree pat1, tree pat2)
15292 bool any_deductions = false;
15294 tmpl1 = TREE_TYPE (pat1);
15295 tmpl2 = TREE_TYPE (pat2);
15297 /* Just like what happens for functions, if we are ordering between
15298 different class template specializations, we may encounter dependent
15299 types in the arguments, and we need our dependency check functions
15300 to behave correctly. */
15301 ++processing_template_decl;
15302 targs = get_class_bindings (TREE_VALUE (pat1),
15303 CLASSTYPE_TI_ARGS (tmpl1),
15304 CLASSTYPE_TI_ARGS (tmpl2));
15308 any_deductions = true;
15311 targs = get_class_bindings (TREE_VALUE (pat2),
15312 CLASSTYPE_TI_ARGS (tmpl2),
15313 CLASSTYPE_TI_ARGS (tmpl1));
15317 any_deductions = true;
15319 --processing_template_decl;
15321 /* In the case of a tie where at least one of the class templates
15322 has a parameter pack at the end, the template with the most
15323 non-packed parameters wins. */
15326 && (template_args_variadic_p (TREE_PURPOSE (pat1))
15327 || template_args_variadic_p (TREE_PURPOSE (pat2))))
15329 tree args1 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat1));
15330 tree args2 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat2));
15331 int len1 = TREE_VEC_LENGTH (args1);
15332 int len2 = TREE_VEC_LENGTH (args2);
15334 /* We don't count the pack expansion at the end. */
15335 if (template_args_variadic_p (TREE_PURPOSE (pat1)))
15337 if (template_args_variadic_p (TREE_PURPOSE (pat2)))
15342 else if (len1 < len2)
15349 /* Return the template arguments that will produce the function signature
15350 DECL from the function template FN, with the explicit template
15351 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
15352 also match. Return NULL_TREE if no satisfactory arguments could be
15356 get_bindings (tree fn, tree decl, tree explicit_args, bool check_rettype)
15358 int ntparms = DECL_NTPARMS (fn);
15359 tree targs = make_tree_vec (ntparms);
15361 tree decl_arg_types;
15363 unsigned int nargs, ix;
15366 /* Substitute the explicit template arguments into the type of DECL.
15367 The call to fn_type_unification will handle substitution into the
15369 decl_type = TREE_TYPE (decl);
15370 if (explicit_args && uses_template_parms (decl_type))
15373 tree converted_args;
15375 if (DECL_TEMPLATE_INFO (decl))
15376 tmpl = DECL_TI_TEMPLATE (decl);
15378 /* We can get here for some invalid specializations. */
15382 = coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
15383 explicit_args, NULL_TREE,
15385 /*require_all_args=*/false,
15386 /*use_default_args=*/false);
15387 if (converted_args == error_mark_node)
15390 decl_type = tsubst (decl_type, converted_args, tf_none, NULL_TREE);
15391 if (decl_type == error_mark_node)
15395 /* Never do unification on the 'this' parameter. */
15396 decl_arg_types = skip_artificial_parms_for (decl,
15397 TYPE_ARG_TYPES (decl_type));
15399 nargs = list_length (decl_arg_types);
15400 args = XALLOCAVEC (tree, nargs);
15401 for (arg = decl_arg_types, ix = 0;
15402 arg != NULL_TREE && arg != void_list_node;
15403 arg = TREE_CHAIN (arg), ++ix)
15404 args[ix] = TREE_VALUE (arg);
15406 if (fn_type_unification (fn, explicit_args, targs,
15408 (check_rettype || DECL_CONV_FN_P (fn)
15409 ? TREE_TYPE (decl_type) : NULL_TREE),
15410 DEDUCE_EXACT, LOOKUP_NORMAL))
15416 /* Return the innermost template arguments that, when applied to a
15417 template specialization whose innermost template parameters are
15418 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
15421 For example, suppose we have:
15423 template <class T, class U> struct S {};
15424 template <class T> struct S<T*, int> {};
15426 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
15427 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
15428 int}. The resulting vector will be {double}, indicating that `T'
15429 is bound to `double'. */
15432 get_class_bindings (tree tparms, tree spec_args, tree args)
15434 int i, ntparms = TREE_VEC_LENGTH (tparms);
15436 tree innermost_deduced_args;
15438 innermost_deduced_args = make_tree_vec (ntparms);
15439 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
15441 deduced_args = copy_node (args);
15442 SET_TMPL_ARGS_LEVEL (deduced_args,
15443 TMPL_ARGS_DEPTH (deduced_args),
15444 innermost_deduced_args);
15447 deduced_args = innermost_deduced_args;
15449 if (unify (tparms, deduced_args,
15450 INNERMOST_TEMPLATE_ARGS (spec_args),
15451 INNERMOST_TEMPLATE_ARGS (args),
15455 for (i = 0; i < ntparms; ++i)
15456 if (! TREE_VEC_ELT (innermost_deduced_args, i))
15459 /* Verify that nondeduced template arguments agree with the type
15460 obtained from argument deduction.
15464 struct A { typedef int X; };
15465 template <class T, class U> struct C {};
15466 template <class T> struct C<T, typename T::X> {};
15468 Then with the instantiation `C<A, int>', we can deduce that
15469 `T' is `A' but unify () does not check whether `typename T::X'
15471 spec_args = tsubst (spec_args, deduced_args, tf_none, NULL_TREE);
15472 if (spec_args == error_mark_node
15473 /* We only need to check the innermost arguments; the other
15474 arguments will always agree. */
15475 || !comp_template_args (INNERMOST_TEMPLATE_ARGS (spec_args),
15476 INNERMOST_TEMPLATE_ARGS (args)))
15479 /* Now that we have bindings for all of the template arguments,
15480 ensure that the arguments deduced for the template template
15481 parameters have compatible template parameter lists. See the use
15482 of template_template_parm_bindings_ok_p in fn_type_unification
15483 for more information. */
15484 if (!template_template_parm_bindings_ok_p (tparms, deduced_args))
15487 return deduced_args;
15490 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
15491 Return the TREE_LIST node with the most specialized template, if
15492 any. If there is no most specialized template, the error_mark_node
15495 Note that this function does not look at, or modify, the
15496 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
15497 returned is one of the elements of INSTANTIATIONS, callers may
15498 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
15499 and retrieve it from the value returned. */
15502 most_specialized_instantiation (tree templates)
15506 ++processing_template_decl;
15509 for (fn = TREE_CHAIN (templates); fn; fn = TREE_CHAIN (fn))
15513 if (get_bindings (TREE_VALUE (champ),
15514 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
15515 NULL_TREE, /*check_ret=*/false))
15518 if (get_bindings (TREE_VALUE (fn),
15519 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
15520 NULL_TREE, /*check_ret=*/false))
15527 /* Equally specialized, move to next function. If there
15528 is no next function, nothing's most specialized. */
15529 fn = TREE_CHAIN (fn);
15537 /* Now verify that champ is better than everything earlier in the
15538 instantiation list. */
15539 for (fn = templates; fn != champ; fn = TREE_CHAIN (fn))
15540 if (get_bindings (TREE_VALUE (champ),
15541 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
15542 NULL_TREE, /*check_ret=*/false)
15543 || !get_bindings (TREE_VALUE (fn),
15544 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
15545 NULL_TREE, /*check_ret=*/false))
15551 processing_template_decl--;
15554 return error_mark_node;
15559 /* If DECL is a specialization of some template, return the most
15560 general such template. Otherwise, returns NULL_TREE.
15562 For example, given:
15564 template <class T> struct S { template <class U> void f(U); };
15566 if TMPL is `template <class U> void S<int>::f(U)' this will return
15567 the full template. This function will not trace past partial
15568 specializations, however. For example, given in addition:
15570 template <class T> struct S<T*> { template <class U> void f(U); };
15572 if TMPL is `template <class U> void S<int*>::f(U)' this will return
15573 `template <class T> template <class U> S<T*>::f(U)'. */
15576 most_general_template (tree decl)
15578 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
15579 an immediate specialization. */
15580 if (TREE_CODE (decl) == FUNCTION_DECL)
15582 if (DECL_TEMPLATE_INFO (decl)) {
15583 decl = DECL_TI_TEMPLATE (decl);
15585 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
15586 template friend. */
15587 if (TREE_CODE (decl) != TEMPLATE_DECL)
15593 /* Look for more and more general templates. */
15594 while (DECL_TEMPLATE_INFO (decl))
15596 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
15597 (See cp-tree.h for details.) */
15598 if (TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
15601 if (CLASS_TYPE_P (TREE_TYPE (decl))
15602 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)))
15605 /* Stop if we run into an explicitly specialized class template. */
15606 if (!DECL_NAMESPACE_SCOPE_P (decl)
15607 && DECL_CONTEXT (decl)
15608 && CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (decl)))
15611 decl = DECL_TI_TEMPLATE (decl);
15617 /* Return the most specialized of the class template partial
15618 specializations of TMPL which can produce TYPE, a specialization of
15619 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
15620 a _TYPE node corresponding to the partial specialization, while the
15621 TREE_PURPOSE is the set of template arguments that must be
15622 substituted into the TREE_TYPE in order to generate TYPE.
15624 If the choice of partial specialization is ambiguous, a diagnostic
15625 is issued, and the error_mark_node is returned. If there are no
15626 partial specializations of TMPL matching TYPE, then NULL_TREE is
15630 most_specialized_class (tree type, tree tmpl)
15632 tree list = NULL_TREE;
15638 tree outer_args = NULL_TREE;
15640 tmpl = most_general_template (tmpl);
15641 args = CLASSTYPE_TI_ARGS (type);
15643 /* For determining which partial specialization to use, only the
15644 innermost args are interesting. */
15645 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
15647 outer_args = strip_innermost_template_args (args, 1);
15648 args = INNERMOST_TEMPLATE_ARGS (args);
15651 for (t = DECL_TEMPLATE_SPECIALIZATIONS (tmpl); t; t = TREE_CHAIN (t))
15653 tree partial_spec_args;
15655 tree parms = TREE_VALUE (t);
15657 partial_spec_args = CLASSTYPE_TI_ARGS (TREE_TYPE (t));
15662 ++processing_template_decl;
15664 /* Discard the outer levels of args, and then substitute in the
15665 template args from the enclosing class. */
15666 partial_spec_args = INNERMOST_TEMPLATE_ARGS (partial_spec_args);
15667 partial_spec_args = tsubst_template_args
15668 (partial_spec_args, outer_args, tf_none, NULL_TREE);
15670 /* PARMS already refers to just the innermost parms, but the
15671 template parms in partial_spec_args had their levels lowered
15672 by tsubst, so we need to do the same for the parm list. We
15673 can't just tsubst the TREE_VEC itself, as tsubst wants to
15674 treat a TREE_VEC as an argument vector. */
15675 parms = copy_node (parms);
15676 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
15677 TREE_VEC_ELT (parms, i) =
15678 tsubst (TREE_VEC_ELT (parms, i), outer_args, tf_none, NULL_TREE);
15680 --processing_template_decl;
15682 spec_args = get_class_bindings (parms,
15688 spec_args = add_to_template_args (outer_args, spec_args);
15689 list = tree_cons (spec_args, TREE_VALUE (t), list);
15690 TREE_TYPE (list) = TREE_TYPE (t);
15697 ambiguous_p = false;
15700 t = TREE_CHAIN (t);
15701 for (; t; t = TREE_CHAIN (t))
15703 fate = more_specialized_class (champ, t);
15710 t = TREE_CHAIN (t);
15713 ambiguous_p = true;
15722 for (t = list; t && t != champ; t = TREE_CHAIN (t))
15724 fate = more_specialized_class (champ, t);
15727 ambiguous_p = true;
15734 const char *str = "candidates are:";
15735 error ("ambiguous class template instantiation for %q#T", type);
15736 for (t = list; t; t = TREE_CHAIN (t))
15738 error ("%s %+#T", str, TREE_TYPE (t));
15741 return error_mark_node;
15747 /* Explicitly instantiate DECL. */
15750 do_decl_instantiation (tree decl, tree storage)
15752 tree result = NULL_TREE;
15755 if (!decl || decl == error_mark_node)
15756 /* An error occurred, for which grokdeclarator has already issued
15757 an appropriate message. */
15759 else if (! DECL_LANG_SPECIFIC (decl))
15761 error ("explicit instantiation of non-template %q#D", decl);
15764 else if (TREE_CODE (decl) == VAR_DECL)
15766 /* There is an asymmetry here in the way VAR_DECLs and
15767 FUNCTION_DECLs are handled by grokdeclarator. In the case of
15768 the latter, the DECL we get back will be marked as a
15769 template instantiation, and the appropriate
15770 DECL_TEMPLATE_INFO will be set up. This does not happen for
15771 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
15772 should handle VAR_DECLs as it currently handles
15774 if (!DECL_CLASS_SCOPE_P (decl))
15776 error ("%qD is not a static data member of a class template", decl);
15779 result = lookup_field (DECL_CONTEXT (decl), DECL_NAME (decl), 0, false);
15780 if (!result || TREE_CODE (result) != VAR_DECL)
15782 error ("no matching template for %qD found", decl);
15785 if (!same_type_p (TREE_TYPE (result), TREE_TYPE (decl)))
15787 error ("type %qT for explicit instantiation %qD does not match "
15788 "declared type %qT", TREE_TYPE (result), decl,
15793 else if (TREE_CODE (decl) != FUNCTION_DECL)
15795 error ("explicit instantiation of %q#D", decl);
15801 /* Check for various error cases. Note that if the explicit
15802 instantiation is valid the RESULT will currently be marked as an
15803 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
15804 until we get here. */
15806 if (DECL_TEMPLATE_SPECIALIZATION (result))
15808 /* DR 259 [temp.spec].
15810 Both an explicit instantiation and a declaration of an explicit
15811 specialization shall not appear in a program unless the explicit
15812 instantiation follows a declaration of the explicit specialization.
15814 For a given set of template parameters, if an explicit
15815 instantiation of a template appears after a declaration of an
15816 explicit specialization for that template, the explicit
15817 instantiation has no effect. */
15820 else if (DECL_EXPLICIT_INSTANTIATION (result))
15824 No program shall explicitly instantiate any template more
15827 We check DECL_NOT_REALLY_EXTERN so as not to complain when
15828 the first instantiation was `extern' and the second is not,
15829 and EXTERN_P for the opposite case. */
15830 if (DECL_NOT_REALLY_EXTERN (result) && !extern_p)
15831 permerror (input_location, "duplicate explicit instantiation of %q#D", result);
15832 /* If an "extern" explicit instantiation follows an ordinary
15833 explicit instantiation, the template is instantiated. */
15837 else if (!DECL_IMPLICIT_INSTANTIATION (result))
15839 error ("no matching template for %qD found", result);
15842 else if (!DECL_TEMPLATE_INFO (result))
15844 permerror (input_location, "explicit instantiation of non-template %q#D", result);
15848 if (storage == NULL_TREE)
15850 else if (storage == ridpointers[(int) RID_EXTERN])
15852 if (!in_system_header && (cxx_dialect == cxx98))
15853 pedwarn (input_location, OPT_pedantic,
15854 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
15859 error ("storage class %qD applied to template instantiation", storage);
15861 check_explicit_instantiation_namespace (result);
15862 mark_decl_instantiated (result, extern_p);
15864 instantiate_decl (result, /*defer_ok=*/1,
15865 /*expl_inst_class_mem_p=*/false);
15869 mark_class_instantiated (tree t, int extern_p)
15871 SET_CLASSTYPE_EXPLICIT_INSTANTIATION (t);
15872 SET_CLASSTYPE_INTERFACE_KNOWN (t);
15873 CLASSTYPE_INTERFACE_ONLY (t) = extern_p;
15874 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (t)) = extern_p;
15877 CLASSTYPE_DEBUG_REQUESTED (t) = 1;
15878 rest_of_type_compilation (t, 1);
15882 /* Called from do_type_instantiation through binding_table_foreach to
15883 do recursive instantiation for the type bound in ENTRY. */
15885 bt_instantiate_type_proc (binding_entry entry, void *data)
15887 tree storage = *(tree *) data;
15889 if (MAYBE_CLASS_TYPE_P (entry->type)
15890 && !uses_template_parms (CLASSTYPE_TI_ARGS (entry->type)))
15891 do_type_instantiation (TYPE_MAIN_DECL (entry->type), storage, 0);
15894 /* Called from do_type_instantiation to instantiate a member
15895 (a member function or a static member variable) of an
15896 explicitly instantiated class template. */
15898 instantiate_class_member (tree decl, int extern_p)
15900 mark_decl_instantiated (decl, extern_p);
15902 instantiate_decl (decl, /*defer_ok=*/1,
15903 /*expl_inst_class_mem_p=*/true);
15906 /* Perform an explicit instantiation of template class T. STORAGE, if
15907 non-null, is the RID for extern, inline or static. COMPLAIN is
15908 nonzero if this is called from the parser, zero if called recursively,
15909 since the standard is unclear (as detailed below). */
15912 do_type_instantiation (tree t, tree storage, tsubst_flags_t complain)
15917 int previous_instantiation_extern_p = 0;
15919 if (TREE_CODE (t) == TYPE_DECL)
15922 if (! CLASS_TYPE_P (t) || ! CLASSTYPE_TEMPLATE_INFO (t))
15924 error ("explicit instantiation of non-template type %qT", t);
15930 if (!COMPLETE_TYPE_P (t))
15932 if (complain & tf_error)
15933 error ("explicit instantiation of %q#T before definition of template",
15938 if (storage != NULL_TREE)
15940 if (!in_system_header)
15942 if (storage == ridpointers[(int) RID_EXTERN])
15944 if (cxx_dialect == cxx98)
15945 pedwarn (input_location, OPT_pedantic,
15946 "ISO C++ 1998 forbids the use of %<extern%> on "
15947 "explicit instantiations");
15950 pedwarn (input_location, OPT_pedantic,
15951 "ISO C++ forbids the use of %qE"
15952 " on explicit instantiations", storage);
15955 if (storage == ridpointers[(int) RID_INLINE])
15957 else if (storage == ridpointers[(int) RID_EXTERN])
15959 else if (storage == ridpointers[(int) RID_STATIC])
15963 error ("storage class %qD applied to template instantiation",
15969 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (t))
15971 /* DR 259 [temp.spec].
15973 Both an explicit instantiation and a declaration of an explicit
15974 specialization shall not appear in a program unless the explicit
15975 instantiation follows a declaration of the explicit specialization.
15977 For a given set of template parameters, if an explicit
15978 instantiation of a template appears after a declaration of an
15979 explicit specialization for that template, the explicit
15980 instantiation has no effect. */
15983 else if (CLASSTYPE_EXPLICIT_INSTANTIATION (t))
15987 No program shall explicitly instantiate any template more
15990 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
15991 instantiation was `extern'. If EXTERN_P then the second is.
15992 These cases are OK. */
15993 previous_instantiation_extern_p = CLASSTYPE_INTERFACE_ONLY (t);
15995 if (!previous_instantiation_extern_p && !extern_p
15996 && (complain & tf_error))
15997 permerror (input_location, "duplicate explicit instantiation of %q#T", t);
15999 /* If we've already instantiated the template, just return now. */
16000 if (!CLASSTYPE_INTERFACE_ONLY (t))
16004 check_explicit_instantiation_namespace (TYPE_NAME (t));
16005 mark_class_instantiated (t, extern_p);
16013 /* In contrast to implicit instantiation, where only the
16014 declarations, and not the definitions, of members are
16015 instantiated, we have here:
16019 The explicit instantiation of a class template specialization
16020 implies the instantiation of all of its members not
16021 previously explicitly specialized in the translation unit
16022 containing the explicit instantiation.
16024 Of course, we can't instantiate member template classes, since
16025 we don't have any arguments for them. Note that the standard
16026 is unclear on whether the instantiation of the members are
16027 *explicit* instantiations or not. However, the most natural
16028 interpretation is that it should be an explicit instantiation. */
16031 for (tmp = TYPE_METHODS (t); tmp; tmp = TREE_CHAIN (tmp))
16032 if (TREE_CODE (tmp) == FUNCTION_DECL
16033 && DECL_TEMPLATE_INSTANTIATION (tmp))
16034 instantiate_class_member (tmp, extern_p);
16036 for (tmp = TYPE_FIELDS (t); tmp; tmp = TREE_CHAIN (tmp))
16037 if (TREE_CODE (tmp) == VAR_DECL && DECL_TEMPLATE_INSTANTIATION (tmp))
16038 instantiate_class_member (tmp, extern_p);
16040 if (CLASSTYPE_NESTED_UTDS (t))
16041 binding_table_foreach (CLASSTYPE_NESTED_UTDS (t),
16042 bt_instantiate_type_proc, &storage);
16046 /* Given a function DECL, which is a specialization of TMPL, modify
16047 DECL to be a re-instantiation of TMPL with the same template
16048 arguments. TMPL should be the template into which tsubst'ing
16049 should occur for DECL, not the most general template.
16051 One reason for doing this is a scenario like this:
16054 void f(const T&, int i);
16056 void g() { f(3, 7); }
16059 void f(const T& t, const int i) { }
16061 Note that when the template is first instantiated, with
16062 instantiate_template, the resulting DECL will have no name for the
16063 first parameter, and the wrong type for the second. So, when we go
16064 to instantiate the DECL, we regenerate it. */
16067 regenerate_decl_from_template (tree decl, tree tmpl)
16069 /* The arguments used to instantiate DECL, from the most general
16074 args = DECL_TI_ARGS (decl);
16075 code_pattern = DECL_TEMPLATE_RESULT (tmpl);
16077 /* Make sure that we can see identifiers, and compute access
16079 push_access_scope (decl);
16081 if (TREE_CODE (decl) == FUNCTION_DECL)
16089 args_depth = TMPL_ARGS_DEPTH (args);
16090 parms_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
16091 if (args_depth > parms_depth)
16092 args = get_innermost_template_args (args, parms_depth);
16094 specs = tsubst_exception_specification (TREE_TYPE (code_pattern),
16095 args, tf_error, NULL_TREE);
16097 TREE_TYPE (decl) = build_exception_variant (TREE_TYPE (decl),
16100 /* Merge parameter declarations. */
16101 decl_parm = skip_artificial_parms_for (decl,
16102 DECL_ARGUMENTS (decl));
16104 = skip_artificial_parms_for (code_pattern,
16105 DECL_ARGUMENTS (code_pattern));
16106 while (decl_parm && !FUNCTION_PARAMETER_PACK_P (pattern_parm))
16111 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
16112 DECL_NAME (decl_parm) = DECL_NAME (pattern_parm);
16113 parm_type = tsubst (TREE_TYPE (pattern_parm), args, tf_error,
16115 parm_type = type_decays_to (parm_type);
16116 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
16117 TREE_TYPE (decl_parm) = parm_type;
16118 attributes = DECL_ATTRIBUTES (pattern_parm);
16119 if (DECL_ATTRIBUTES (decl_parm) != attributes)
16121 DECL_ATTRIBUTES (decl_parm) = attributes;
16122 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
16124 decl_parm = TREE_CHAIN (decl_parm);
16125 pattern_parm = TREE_CHAIN (pattern_parm);
16127 /* Merge any parameters that match with the function parameter
16129 if (pattern_parm && FUNCTION_PARAMETER_PACK_P (pattern_parm))
16132 tree expanded_types;
16133 /* Expand the TYPE_PACK_EXPANSION that provides the types for
16134 the parameters in this function parameter pack. */
16135 expanded_types = tsubst_pack_expansion (TREE_TYPE (pattern_parm),
16136 args, tf_error, NULL_TREE);
16137 len = TREE_VEC_LENGTH (expanded_types);
16138 for (i = 0; i < len; i++)
16143 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
16144 /* Rename the parameter to include the index. */
16145 DECL_NAME (decl_parm) =
16146 make_ith_pack_parameter_name (DECL_NAME (pattern_parm), i);
16147 parm_type = TREE_VEC_ELT (expanded_types, i);
16148 parm_type = type_decays_to (parm_type);
16149 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
16150 TREE_TYPE (decl_parm) = parm_type;
16151 attributes = DECL_ATTRIBUTES (pattern_parm);
16152 if (DECL_ATTRIBUTES (decl_parm) != attributes)
16154 DECL_ATTRIBUTES (decl_parm) = attributes;
16155 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
16157 decl_parm = TREE_CHAIN (decl_parm);
16160 /* Merge additional specifiers from the CODE_PATTERN. */
16161 if (DECL_DECLARED_INLINE_P (code_pattern)
16162 && !DECL_DECLARED_INLINE_P (decl))
16163 DECL_DECLARED_INLINE_P (decl) = 1;
16165 else if (TREE_CODE (decl) == VAR_DECL)
16166 DECL_INITIAL (decl) =
16167 tsubst_expr (DECL_INITIAL (code_pattern), args,
16168 tf_error, DECL_TI_TEMPLATE (decl),
16169 /*integral_constant_expression_p=*/false);
16171 gcc_unreachable ();
16173 pop_access_scope (decl);
16176 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
16177 substituted to get DECL. */
16180 template_for_substitution (tree decl)
16182 tree tmpl = DECL_TI_TEMPLATE (decl);
16184 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
16185 for the instantiation. This is not always the most general
16186 template. Consider, for example:
16189 struct S { template <class U> void f();
16190 template <> void f<int>(); };
16192 and an instantiation of S<double>::f<int>. We want TD to be the
16193 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
16194 while (/* An instantiation cannot have a definition, so we need a
16195 more general template. */
16196 DECL_TEMPLATE_INSTANTIATION (tmpl)
16197 /* We must also deal with friend templates. Given:
16199 template <class T> struct S {
16200 template <class U> friend void f() {};
16203 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
16204 so far as the language is concerned, but that's still
16205 where we get the pattern for the instantiation from. On
16206 other hand, if the definition comes outside the class, say:
16208 template <class T> struct S {
16209 template <class U> friend void f();
16211 template <class U> friend void f() {}
16213 we don't need to look any further. That's what the check for
16214 DECL_INITIAL is for. */
16215 || (TREE_CODE (decl) == FUNCTION_DECL
16216 && DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION (tmpl)
16217 && !DECL_INITIAL (DECL_TEMPLATE_RESULT (tmpl))))
16219 /* The present template, TD, should not be a definition. If it
16220 were a definition, we should be using it! Note that we
16221 cannot restructure the loop to just keep going until we find
16222 a template with a definition, since that might go too far if
16223 a specialization was declared, but not defined. */
16224 gcc_assert (TREE_CODE (decl) != VAR_DECL
16225 || DECL_IN_AGGR_P (DECL_TEMPLATE_RESULT (tmpl)));
16227 /* Fetch the more general template. */
16228 tmpl = DECL_TI_TEMPLATE (tmpl);
16234 /* Returns true if we need to instantiate this template instance even if we
16235 know we aren't going to emit it.. */
16238 always_instantiate_p (tree decl)
16240 /* We always instantiate inline functions so that we can inline them. An
16241 explicit instantiation declaration prohibits implicit instantiation of
16242 non-inline functions. With high levels of optimization, we would
16243 normally inline non-inline functions -- but we're not allowed to do
16244 that for "extern template" functions. Therefore, we check
16245 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
16246 return ((TREE_CODE (decl) == FUNCTION_DECL
16247 && DECL_DECLARED_INLINE_P (decl))
16248 /* And we need to instantiate static data members so that
16249 their initializers are available in integral constant
16251 || (TREE_CODE (decl) == VAR_DECL
16252 && DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (decl)));
16255 /* Produce the definition of D, a _DECL generated from a template. If
16256 DEFER_OK is nonzero, then we don't have to actually do the
16257 instantiation now; we just have to do it sometime. Normally it is
16258 an error if this is an explicit instantiation but D is undefined.
16259 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
16260 explicitly instantiated class template. */
16263 instantiate_decl (tree d, int defer_ok,
16264 bool expl_inst_class_mem_p)
16266 tree tmpl = DECL_TI_TEMPLATE (d);
16273 bool pattern_defined;
16275 location_t saved_loc = input_location;
16278 /* This function should only be used to instantiate templates for
16279 functions and static member variables. */
16280 gcc_assert (TREE_CODE (d) == FUNCTION_DECL
16281 || TREE_CODE (d) == VAR_DECL);
16283 /* Variables are never deferred; if instantiation is required, they
16284 are instantiated right away. That allows for better code in the
16285 case that an expression refers to the value of the variable --
16286 if the variable has a constant value the referring expression can
16287 take advantage of that fact. */
16288 if (TREE_CODE (d) == VAR_DECL)
16291 /* Don't instantiate cloned functions. Instead, instantiate the
16292 functions they cloned. */
16293 if (TREE_CODE (d) == FUNCTION_DECL && DECL_CLONED_FUNCTION_P (d))
16294 d = DECL_CLONED_FUNCTION (d);
16296 if (DECL_TEMPLATE_INSTANTIATED (d)
16297 || DECL_TEMPLATE_SPECIALIZATION (d))
16298 /* D has already been instantiated or explicitly specialized, so
16299 there's nothing for us to do here.
16301 It might seem reasonable to check whether or not D is an explicit
16302 instantiation, and, if so, stop here. But when an explicit
16303 instantiation is deferred until the end of the compilation,
16304 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
16305 the instantiation. */
16308 /* Check to see whether we know that this template will be
16309 instantiated in some other file, as with "extern template"
16311 external_p = (DECL_INTERFACE_KNOWN (d) && DECL_REALLY_EXTERN (d));
16313 /* In general, we do not instantiate such templates. */
16314 if (external_p && !always_instantiate_p (d))
16317 gen_tmpl = most_general_template (tmpl);
16318 gen_args = DECL_TI_ARGS (d);
16320 if (tmpl != gen_tmpl)
16321 /* We should already have the extra args. */
16322 gcc_assert (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (gen_tmpl))
16323 == TMPL_ARGS_DEPTH (gen_args));
16324 /* And what's in the hash table should match D. */
16325 gcc_assert ((spec = retrieve_specialization (gen_tmpl, gen_args, 0)) == d
16326 || spec == NULL_TREE);
16328 /* This needs to happen before any tsubsting. */
16329 if (! push_tinst_level (d))
16332 timevar_push (TV_PARSE);
16334 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
16335 for the instantiation. */
16336 td = template_for_substitution (d);
16337 code_pattern = DECL_TEMPLATE_RESULT (td);
16339 /* We should never be trying to instantiate a member of a class
16340 template or partial specialization. */
16341 gcc_assert (d != code_pattern);
16343 if ((DECL_NAMESPACE_SCOPE_P (d) && !DECL_INITIALIZED_IN_CLASS_P (d))
16344 || DECL_TEMPLATE_SPECIALIZATION (td))
16345 /* In the case of a friend template whose definition is provided
16346 outside the class, we may have too many arguments. Drop the
16347 ones we don't need. The same is true for specializations. */
16348 args = get_innermost_template_args
16349 (gen_args, TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (td)));
16353 if (TREE_CODE (d) == FUNCTION_DECL)
16354 pattern_defined = (DECL_SAVED_TREE (code_pattern) != NULL_TREE);
16356 pattern_defined = ! DECL_IN_AGGR_P (code_pattern);
16358 /* We may be in the middle of deferred access check. Disable it now. */
16359 push_deferring_access_checks (dk_no_deferred);
16361 /* Unless an explicit instantiation directive has already determined
16362 the linkage of D, remember that a definition is available for
16364 if (pattern_defined
16365 && !DECL_INTERFACE_KNOWN (d)
16366 && !DECL_NOT_REALLY_EXTERN (d))
16367 mark_definable (d);
16369 input_location = DECL_SOURCE_LOCATION (d);
16371 /* If D is a member of an explicitly instantiated class template,
16372 and no definition is available, treat it like an implicit
16374 if (!pattern_defined && expl_inst_class_mem_p
16375 && DECL_EXPLICIT_INSTANTIATION (d))
16377 DECL_NOT_REALLY_EXTERN (d) = 0;
16378 DECL_INTERFACE_KNOWN (d) = 0;
16379 SET_DECL_IMPLICIT_INSTANTIATION (d);
16382 /* Recheck the substitutions to obtain any warning messages
16383 about ignoring cv qualifiers. Don't do this for artificial decls,
16384 as it breaks the context-sensitive substitution for lambda op(). */
16385 if (!defer_ok && !DECL_ARTIFICIAL (d))
16387 tree gen = DECL_TEMPLATE_RESULT (gen_tmpl);
16388 tree type = TREE_TYPE (gen);
16390 /* Make sure that we can see identifiers, and compute access
16391 correctly. D is already the target FUNCTION_DECL with the
16393 push_access_scope (d);
16395 if (TREE_CODE (gen) == FUNCTION_DECL)
16397 tsubst (DECL_ARGUMENTS (gen), gen_args, tf_warning_or_error, d);
16398 tsubst_exception_specification (type, gen_args, tf_warning_or_error,
16400 /* Don't simply tsubst the function type, as that will give
16401 duplicate warnings about poor parameter qualifications.
16402 The function arguments are the same as the decl_arguments
16403 without the top level cv qualifiers. */
16404 type = TREE_TYPE (type);
16406 tsubst (type, gen_args, tf_warning_or_error, d);
16408 pop_access_scope (d);
16411 /* Defer all other templates, unless we have been explicitly
16412 forbidden from doing so. */
16413 if (/* If there is no definition, we cannot instantiate the
16416 /* If it's OK to postpone instantiation, do so. */
16418 /* If this is a static data member that will be defined
16419 elsewhere, we don't want to instantiate the entire data
16420 member, but we do want to instantiate the initializer so that
16421 we can substitute that elsewhere. */
16422 || (external_p && TREE_CODE (d) == VAR_DECL))
16424 /* The definition of the static data member is now required so
16425 we must substitute the initializer. */
16426 if (TREE_CODE (d) == VAR_DECL
16427 && !DECL_INITIAL (d)
16428 && DECL_INITIAL (code_pattern))
16433 ns = decl_namespace_context (d);
16434 push_nested_namespace (ns);
16435 push_nested_class (DECL_CONTEXT (d));
16436 init = tsubst_expr (DECL_INITIAL (code_pattern),
16438 tf_warning_or_error, NULL_TREE,
16439 /*integral_constant_expression_p=*/false);
16440 cp_finish_decl (d, init, /*init_const_expr_p=*/false,
16441 /*asmspec_tree=*/NULL_TREE,
16442 LOOKUP_ONLYCONVERTING);
16443 pop_nested_class ();
16444 pop_nested_namespace (ns);
16447 /* We restore the source position here because it's used by
16448 add_pending_template. */
16449 input_location = saved_loc;
16451 if (at_eof && !pattern_defined
16452 && DECL_EXPLICIT_INSTANTIATION (d)
16453 && DECL_NOT_REALLY_EXTERN (d))
16456 The definition of a non-exported function template, a
16457 non-exported member function template, or a non-exported
16458 member function or static data member of a class template
16459 shall be present in every translation unit in which it is
16460 explicitly instantiated. */
16461 permerror (input_location, "explicit instantiation of %qD "
16462 "but no definition available", d);
16464 /* ??? Historically, we have instantiated inline functions, even
16465 when marked as "extern template". */
16466 if (!(external_p && TREE_CODE (d) == VAR_DECL))
16467 add_pending_template (d);
16470 /* Tell the repository that D is available in this translation unit
16471 -- and see if it is supposed to be instantiated here. */
16472 if (TREE_PUBLIC (d) && !DECL_REALLY_EXTERN (d) && !repo_emit_p (d))
16474 /* In a PCH file, despite the fact that the repository hasn't
16475 requested instantiation in the PCH it is still possible that
16476 an instantiation will be required in a file that includes the
16479 add_pending_template (d);
16480 /* Instantiate inline functions so that the inliner can do its
16481 job, even though we'll not be emitting a copy of this
16483 if (!(TREE_CODE (d) == FUNCTION_DECL && possibly_inlined_p (d)))
16487 need_push = !cfun || !global_bindings_p ();
16489 push_to_top_level ();
16491 /* Mark D as instantiated so that recursive calls to
16492 instantiate_decl do not try to instantiate it again. */
16493 DECL_TEMPLATE_INSTANTIATED (d) = 1;
16495 /* Regenerate the declaration in case the template has been modified
16496 by a subsequent redeclaration. */
16497 regenerate_decl_from_template (d, td);
16499 /* We already set the file and line above. Reset them now in case
16500 they changed as a result of calling regenerate_decl_from_template. */
16501 input_location = DECL_SOURCE_LOCATION (d);
16503 if (TREE_CODE (d) == VAR_DECL)
16507 /* Clear out DECL_RTL; whatever was there before may not be right
16508 since we've reset the type of the declaration. */
16509 SET_DECL_RTL (d, NULL_RTX);
16510 DECL_IN_AGGR_P (d) = 0;
16512 /* The initializer is placed in DECL_INITIAL by
16513 regenerate_decl_from_template. Pull it out so that
16514 cp_finish_decl can process it. */
16515 init = DECL_INITIAL (d);
16516 DECL_INITIAL (d) = NULL_TREE;
16517 DECL_INITIALIZED_P (d) = 0;
16519 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
16520 initializer. That function will defer actual emission until
16521 we have a chance to determine linkage. */
16522 DECL_EXTERNAL (d) = 0;
16524 /* Enter the scope of D so that access-checking works correctly. */
16525 push_nested_class (DECL_CONTEXT (d));
16526 cp_finish_decl (d, init, false, NULL_TREE, 0);
16527 pop_nested_class ();
16529 else if (TREE_CODE (d) == FUNCTION_DECL)
16531 htab_t saved_local_specializations;
16536 /* Save away the current list, in case we are instantiating one
16537 template from within the body of another. */
16538 saved_local_specializations = local_specializations;
16540 /* Set up the list of local specializations. */
16541 local_specializations = htab_create (37,
16542 hash_local_specialization,
16543 eq_local_specializations,
16546 /* Set up context. */
16547 start_preparsed_function (d, NULL_TREE, SF_PRE_PARSED);
16549 /* Create substitution entries for the parameters. */
16550 subst_decl = DECL_TEMPLATE_RESULT (template_for_substitution (d));
16551 tmpl_parm = DECL_ARGUMENTS (subst_decl);
16552 spec_parm = DECL_ARGUMENTS (d);
16553 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (d))
16555 register_local_specialization (spec_parm, tmpl_parm);
16556 spec_parm = skip_artificial_parms_for (d, spec_parm);
16557 tmpl_parm = skip_artificial_parms_for (subst_decl, tmpl_parm);
16559 while (tmpl_parm && !FUNCTION_PARAMETER_PACK_P (tmpl_parm))
16561 register_local_specialization (spec_parm, tmpl_parm);
16562 tmpl_parm = TREE_CHAIN (tmpl_parm);
16563 spec_parm = TREE_CHAIN (spec_parm);
16565 if (tmpl_parm && FUNCTION_PARAMETER_PACK_P (tmpl_parm))
16567 /* Register the (value) argument pack as a specialization of
16568 TMPL_PARM, then move on. */
16569 tree argpack = make_fnparm_pack (spec_parm);
16570 register_local_specialization (argpack, tmpl_parm);
16571 tmpl_parm = TREE_CHAIN (tmpl_parm);
16572 spec_parm = NULL_TREE;
16574 gcc_assert (!spec_parm);
16576 /* Substitute into the body of the function. */
16577 tsubst_expr (DECL_SAVED_TREE (code_pattern), args,
16578 tf_warning_or_error, tmpl,
16579 /*integral_constant_expression_p=*/false);
16581 /* Set the current input_location to the end of the function
16582 so that finish_function knows where we are. */
16583 input_location = DECL_STRUCT_FUNCTION (code_pattern)->function_end_locus;
16585 /* We don't need the local specializations any more. */
16586 htab_delete (local_specializations);
16587 local_specializations = saved_local_specializations;
16589 /* Finish the function. */
16590 d = finish_function (0);
16591 expand_or_defer_fn (d);
16594 /* We're not deferring instantiation any more. */
16595 TI_PENDING_TEMPLATE_FLAG (DECL_TEMPLATE_INFO (d)) = 0;
16598 pop_from_top_level ();
16601 input_location = saved_loc;
16602 pop_deferring_access_checks ();
16603 pop_tinst_level ();
16605 timevar_pop (TV_PARSE);
16610 /* Run through the list of templates that we wish we could
16611 instantiate, and instantiate any we can. RETRIES is the
16612 number of times we retry pending template instantiation. */
16615 instantiate_pending_templates (int retries)
16618 location_t saved_loc = input_location;
16620 /* Instantiating templates may trigger vtable generation. This in turn
16621 may require further template instantiations. We place a limit here
16622 to avoid infinite loop. */
16623 if (pending_templates && retries >= max_tinst_depth)
16625 tree decl = pending_templates->tinst->decl;
16627 error ("template instantiation depth exceeds maximum of %d"
16628 " instantiating %q+D, possibly from virtual table generation"
16629 " (use -ftemplate-depth-NN to increase the maximum)",
16630 max_tinst_depth, decl);
16631 if (TREE_CODE (decl) == FUNCTION_DECL)
16632 /* Pretend that we defined it. */
16633 DECL_INITIAL (decl) = error_mark_node;
16639 struct pending_template **t = &pending_templates;
16640 struct pending_template *last = NULL;
16644 tree instantiation = reopen_tinst_level ((*t)->tinst);
16645 bool complete = false;
16647 if (TYPE_P (instantiation))
16651 if (!COMPLETE_TYPE_P (instantiation))
16653 instantiate_class_template (instantiation);
16654 if (CLASSTYPE_TEMPLATE_INSTANTIATION (instantiation))
16655 for (fn = TYPE_METHODS (instantiation);
16657 fn = TREE_CHAIN (fn))
16658 if (! DECL_ARTIFICIAL (fn))
16659 instantiate_decl (fn,
16661 /*expl_inst_class_mem_p=*/false);
16662 if (COMPLETE_TYPE_P (instantiation))
16666 complete = COMPLETE_TYPE_P (instantiation);
16670 if (!DECL_TEMPLATE_SPECIALIZATION (instantiation)
16671 && !DECL_TEMPLATE_INSTANTIATED (instantiation))
16674 = instantiate_decl (instantiation,
16676 /*expl_inst_class_mem_p=*/false);
16677 if (DECL_TEMPLATE_INSTANTIATED (instantiation))
16681 complete = (DECL_TEMPLATE_SPECIALIZATION (instantiation)
16682 || DECL_TEMPLATE_INSTANTIATED (instantiation));
16686 /* If INSTANTIATION has been instantiated, then we don't
16687 need to consider it again in the future. */
16695 current_tinst_level = NULL;
16697 last_pending_template = last;
16699 while (reconsider);
16701 input_location = saved_loc;
16704 /* Substitute ARGVEC into T, which is a list of initializers for
16705 either base class or a non-static data member. The TREE_PURPOSEs
16706 are DECLs, and the TREE_VALUEs are the initializer values. Used by
16707 instantiate_decl. */
16710 tsubst_initializer_list (tree t, tree argvec)
16712 tree inits = NULL_TREE;
16714 for (; t; t = TREE_CHAIN (t))
16718 tree expanded_bases = NULL_TREE;
16719 tree expanded_arguments = NULL_TREE;
16722 if (TREE_CODE (TREE_PURPOSE (t)) == TYPE_PACK_EXPANSION)
16727 /* Expand the base class expansion type into separate base
16729 expanded_bases = tsubst_pack_expansion (TREE_PURPOSE (t), argvec,
16730 tf_warning_or_error,
16732 if (expanded_bases == error_mark_node)
16735 /* We'll be building separate TREE_LISTs of arguments for
16737 len = TREE_VEC_LENGTH (expanded_bases);
16738 expanded_arguments = make_tree_vec (len);
16739 for (i = 0; i < len; i++)
16740 TREE_VEC_ELT (expanded_arguments, i) = NULL_TREE;
16742 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
16743 expand each argument in the TREE_VALUE of t. */
16744 expr = make_node (EXPR_PACK_EXPANSION);
16745 PACK_EXPANSION_PARAMETER_PACKS (expr) =
16746 PACK_EXPANSION_PARAMETER_PACKS (TREE_PURPOSE (t));
16748 if (TREE_VALUE (t) == void_type_node)
16749 /* VOID_TYPE_NODE is used to indicate
16750 value-initialization. */
16752 for (i = 0; i < len; i++)
16753 TREE_VEC_ELT (expanded_arguments, i) = void_type_node;
16757 /* Substitute parameter packs into each argument in the
16759 in_base_initializer = 1;
16760 for (arg = TREE_VALUE (t); arg; arg = TREE_CHAIN (arg))
16762 tree expanded_exprs;
16764 /* Expand the argument. */
16765 SET_PACK_EXPANSION_PATTERN (expr, TREE_VALUE (arg));
16767 = tsubst_pack_expansion (expr, argvec,
16768 tf_warning_or_error,
16770 if (expanded_exprs == error_mark_node)
16773 /* Prepend each of the expanded expressions to the
16774 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
16775 for (i = 0; i < len; i++)
16777 TREE_VEC_ELT (expanded_arguments, i) =
16778 tree_cons (NULL_TREE,
16779 TREE_VEC_ELT (expanded_exprs, i),
16780 TREE_VEC_ELT (expanded_arguments, i));
16783 in_base_initializer = 0;
16785 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
16786 since we built them backwards. */
16787 for (i = 0; i < len; i++)
16789 TREE_VEC_ELT (expanded_arguments, i) =
16790 nreverse (TREE_VEC_ELT (expanded_arguments, i));
16795 for (i = 0; i < len; ++i)
16797 if (expanded_bases)
16799 decl = TREE_VEC_ELT (expanded_bases, i);
16800 decl = expand_member_init (decl);
16801 init = TREE_VEC_ELT (expanded_arguments, i);
16805 decl = tsubst_copy (TREE_PURPOSE (t), argvec,
16806 tf_warning_or_error, NULL_TREE);
16808 decl = expand_member_init (decl);
16809 if (decl && !DECL_P (decl))
16810 in_base_initializer = 1;
16812 init = tsubst_expr (TREE_VALUE (t), argvec,
16813 tf_warning_or_error, NULL_TREE,
16814 /*integral_constant_expression_p=*/false);
16815 in_base_initializer = 0;
16820 init = build_tree_list (decl, init);
16821 TREE_CHAIN (init) = inits;
16829 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
16832 set_current_access_from_decl (tree decl)
16834 if (TREE_PRIVATE (decl))
16835 current_access_specifier = access_private_node;
16836 else if (TREE_PROTECTED (decl))
16837 current_access_specifier = access_protected_node;
16839 current_access_specifier = access_public_node;
16842 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
16843 is the instantiation (which should have been created with
16844 start_enum) and ARGS are the template arguments to use. */
16847 tsubst_enum (tree tag, tree newtag, tree args)
16851 for (e = TYPE_VALUES (tag); e; e = TREE_CHAIN (e))
16856 decl = TREE_VALUE (e);
16857 /* Note that in a template enum, the TREE_VALUE is the
16858 CONST_DECL, not the corresponding INTEGER_CST. */
16859 value = tsubst_expr (DECL_INITIAL (decl),
16860 args, tf_warning_or_error, NULL_TREE,
16861 /*integral_constant_expression_p=*/true);
16863 /* Give this enumeration constant the correct access. */
16864 set_current_access_from_decl (decl);
16866 /* Actually build the enumerator itself. */
16867 build_enumerator (DECL_NAME (decl), value, newtag);
16870 finish_enum (newtag);
16871 DECL_SOURCE_LOCATION (TYPE_NAME (newtag))
16872 = DECL_SOURCE_LOCATION (TYPE_NAME (tag));
16875 /* DECL is a FUNCTION_DECL that is a template specialization. Return
16876 its type -- but without substituting the innermost set of template
16877 arguments. So, innermost set of template parameters will appear in
16881 get_mostly_instantiated_function_type (tree decl)
16889 tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
16890 targs = DECL_TI_ARGS (decl);
16891 tparms = DECL_TEMPLATE_PARMS (tmpl);
16892 parm_depth = TMPL_PARMS_DEPTH (tparms);
16894 /* There should be as many levels of arguments as there are levels
16896 gcc_assert (parm_depth == TMPL_ARGS_DEPTH (targs));
16898 fn_type = TREE_TYPE (tmpl);
16900 if (parm_depth == 1)
16901 /* No substitution is necessary. */
16905 int i, save_access_control;
16908 /* Replace the innermost level of the TARGS with NULL_TREEs to
16909 let tsubst know not to substitute for those parameters. */
16910 partial_args = make_tree_vec (TREE_VEC_LENGTH (targs));
16911 for (i = 1; i < TMPL_ARGS_DEPTH (targs); ++i)
16912 SET_TMPL_ARGS_LEVEL (partial_args, i,
16913 TMPL_ARGS_LEVEL (targs, i));
16914 SET_TMPL_ARGS_LEVEL (partial_args,
16915 TMPL_ARGS_DEPTH (targs),
16916 make_tree_vec (DECL_NTPARMS (tmpl)));
16918 /* Disable access control as this function is used only during
16920 save_access_control = flag_access_control;
16921 flag_access_control = 0;
16923 ++processing_template_decl;
16924 /* Now, do the (partial) substitution to figure out the
16925 appropriate function type. */
16926 fn_type = tsubst (fn_type, partial_args, tf_error, NULL_TREE);
16927 --processing_template_decl;
16929 /* Substitute into the template parameters to obtain the real
16930 innermost set of parameters. This step is important if the
16931 innermost set of template parameters contains value
16932 parameters whose types depend on outer template parameters. */
16933 TREE_VEC_LENGTH (partial_args)--;
16934 tparms = tsubst_template_parms (tparms, partial_args, tf_error);
16936 flag_access_control = save_access_control;
16942 /* Return truthvalue if we're processing a template different from
16943 the last one involved in diagnostics. */
16945 problematic_instantiation_changed (void)
16947 return last_template_error_tick != tinst_level_tick;
16950 /* Remember current template involved in diagnostics. */
16952 record_last_problematic_instantiation (void)
16954 last_template_error_tick = tinst_level_tick;
16957 struct tinst_level *
16958 current_instantiation (void)
16960 return current_tinst_level;
16963 /* [temp.param] Check that template non-type parm TYPE is of an allowable
16964 type. Return zero for ok, nonzero for disallowed. Issue error and
16965 warning messages under control of COMPLAIN. */
16968 invalid_nontype_parm_type_p (tree type, tsubst_flags_t complain)
16970 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
16972 else if (POINTER_TYPE_P (type))
16974 else if (TYPE_PTR_TO_MEMBER_P (type))
16976 else if (TREE_CODE (type) == TEMPLATE_TYPE_PARM)
16978 else if (TREE_CODE (type) == TYPENAME_TYPE)
16981 if (complain & tf_error)
16982 error ("%q#T is not a valid type for a template constant parameter", type);
16986 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
16987 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
16990 dependent_type_p_r (tree type)
16996 A type is dependent if it is:
16998 -- a template parameter. Template template parameters are types
16999 for us (since TYPE_P holds true for them) so we handle
17001 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
17002 || TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM)
17004 /* -- a qualified-id with a nested-name-specifier which contains a
17005 class-name that names a dependent type or whose unqualified-id
17006 names a dependent type. */
17007 if (TREE_CODE (type) == TYPENAME_TYPE)
17009 /* -- a cv-qualified type where the cv-unqualified type is
17011 type = TYPE_MAIN_VARIANT (type);
17012 /* -- a compound type constructed from any dependent type. */
17013 if (TYPE_PTR_TO_MEMBER_P (type))
17014 return (dependent_type_p (TYPE_PTRMEM_CLASS_TYPE (type))
17015 || dependent_type_p (TYPE_PTRMEM_POINTED_TO_TYPE
17017 else if (TREE_CODE (type) == POINTER_TYPE
17018 || TREE_CODE (type) == REFERENCE_TYPE)
17019 return dependent_type_p (TREE_TYPE (type));
17020 else if (TREE_CODE (type) == FUNCTION_TYPE
17021 || TREE_CODE (type) == METHOD_TYPE)
17025 if (dependent_type_p (TREE_TYPE (type)))
17027 for (arg_type = TYPE_ARG_TYPES (type);
17029 arg_type = TREE_CHAIN (arg_type))
17030 if (dependent_type_p (TREE_VALUE (arg_type)))
17034 /* -- an array type constructed from any dependent type or whose
17035 size is specified by a constant expression that is
17036 value-dependent. */
17037 if (TREE_CODE (type) == ARRAY_TYPE)
17039 if (TYPE_DOMAIN (type)
17040 && dependent_type_p (TYPE_DOMAIN (type)))
17042 return dependent_type_p (TREE_TYPE (type));
17044 else if (TREE_CODE (type) == INTEGER_TYPE
17045 && !TREE_CONSTANT (TYPE_MAX_VALUE (type)))
17047 /* If this is the TYPE_DOMAIN of an array type, consider it
17048 dependent. We already checked for value-dependence in
17049 compute_array_index_type. */
17050 return type_dependent_expression_p (TYPE_MAX_VALUE (type));
17053 /* -- a template-id in which either the template name is a template
17055 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
17057 /* ... or any of the template arguments is a dependent type or
17058 an expression that is type-dependent or value-dependent. */
17059 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INFO (type)
17060 && (any_dependent_template_arguments_p
17061 (INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type)))))
17064 /* All TYPEOF_TYPEs and DECLTYPE_TYPEs are dependent; if the
17065 argument of the `typeof' expression is not type-dependent, then
17066 it should already been have resolved. */
17067 if (TREE_CODE (type) == TYPEOF_TYPE
17068 || TREE_CODE (type) == DECLTYPE_TYPE)
17071 /* A template argument pack is dependent if any of its packed
17073 if (TREE_CODE (type) == TYPE_ARGUMENT_PACK)
17075 tree args = ARGUMENT_PACK_ARGS (type);
17076 int i, len = TREE_VEC_LENGTH (args);
17077 for (i = 0; i < len; ++i)
17078 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
17082 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
17083 be template parameters. */
17084 if (TREE_CODE (type) == TYPE_PACK_EXPANSION)
17087 /* The standard does not specifically mention types that are local
17088 to template functions or local classes, but they should be
17089 considered dependent too. For example:
17091 template <int I> void f() {
17096 The size of `E' cannot be known until the value of `I' has been
17097 determined. Therefore, `E' must be considered dependent. */
17098 scope = TYPE_CONTEXT (type);
17099 if (scope && TYPE_P (scope))
17100 return dependent_type_p (scope);
17101 else if (scope && TREE_CODE (scope) == FUNCTION_DECL)
17102 return type_dependent_expression_p (scope);
17104 /* Other types are non-dependent. */
17108 /* Returns TRUE if TYPE is dependent, in the sense of
17109 [temp.dep.type]. */
17112 dependent_type_p (tree type)
17114 /* If there are no template parameters in scope, then there can't be
17115 any dependent types. */
17116 if (!processing_template_decl)
17118 /* If we are not processing a template, then nobody should be
17119 providing us with a dependent type. */
17121 gcc_assert (TREE_CODE (type) != TEMPLATE_TYPE_PARM || is_auto (type));
17125 /* If the type is NULL, we have not computed a type for the entity
17126 in question; in that case, the type is dependent. */
17130 /* Erroneous types can be considered non-dependent. */
17131 if (type == error_mark_node)
17134 /* If we have not already computed the appropriate value for TYPE,
17136 if (!TYPE_DEPENDENT_P_VALID (type))
17138 TYPE_DEPENDENT_P (type) = dependent_type_p_r (type);
17139 TYPE_DEPENDENT_P_VALID (type) = 1;
17142 return TYPE_DEPENDENT_P (type);
17145 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
17146 lookup. In other words, a dependent type that is not the current
17150 dependent_scope_p (tree scope)
17152 return (scope && TYPE_P (scope) && dependent_type_p (scope)
17153 && !currently_open_class (scope));
17156 /* Returns TRUE if EXPRESSION is dependent, according to CRITERION. */
17159 dependent_scope_ref_p (tree expression, bool criterion (tree))
17164 gcc_assert (TREE_CODE (expression) == SCOPE_REF);
17166 if (!TYPE_P (TREE_OPERAND (expression, 0)))
17169 scope = TREE_OPERAND (expression, 0);
17170 name = TREE_OPERAND (expression, 1);
17174 An id-expression is type-dependent if it contains a
17175 nested-name-specifier that contains a class-name that names a
17177 /* The suggested resolution to Core Issue 224 implies that if the
17178 qualifying type is the current class, then we must peek
17181 && currently_open_class (scope)
17182 && !criterion (name))
17184 if (dependent_type_p (scope))
17190 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
17191 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
17195 value_dependent_expression_p (tree expression)
17197 if (!processing_template_decl)
17200 /* A name declared with a dependent type. */
17201 if (DECL_P (expression) && type_dependent_expression_p (expression))
17204 switch (TREE_CODE (expression))
17206 case IDENTIFIER_NODE:
17207 /* A name that has not been looked up -- must be dependent. */
17210 case TEMPLATE_PARM_INDEX:
17211 /* A non-type template parm. */
17215 /* A non-type template parm. */
17216 if (DECL_TEMPLATE_PARM_P (expression))
17218 return value_dependent_expression_p (DECL_INITIAL (expression));
17221 /* A constant with integral or enumeration type and is initialized
17222 with an expression that is value-dependent. */
17223 if (DECL_INITIAL (expression)
17224 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (expression))
17225 && value_dependent_expression_p (DECL_INITIAL (expression)))
17229 case DYNAMIC_CAST_EXPR:
17230 case STATIC_CAST_EXPR:
17231 case CONST_CAST_EXPR:
17232 case REINTERPRET_CAST_EXPR:
17234 /* These expressions are value-dependent if the type to which
17235 the cast occurs is dependent or the expression being casted
17236 is value-dependent. */
17238 tree type = TREE_TYPE (expression);
17240 if (dependent_type_p (type))
17243 /* A functional cast has a list of operands. */
17244 expression = TREE_OPERAND (expression, 0);
17247 /* If there are no operands, it must be an expression such
17248 as "int()". This should not happen for aggregate types
17249 because it would form non-constant expressions. */
17250 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
17255 if (TREE_CODE (expression) == TREE_LIST)
17256 return any_value_dependent_elements_p (expression);
17258 return value_dependent_expression_p (expression);
17263 /* A `sizeof' expression is value-dependent if the operand is
17264 type-dependent or is a pack expansion. */
17265 expression = TREE_OPERAND (expression, 0);
17266 if (PACK_EXPANSION_P (expression))
17268 else if (TYPE_P (expression))
17269 return dependent_type_p (expression);
17270 return type_dependent_expression_p (expression);
17273 return dependent_scope_ref_p (expression, value_dependent_expression_p);
17275 case COMPONENT_REF:
17276 return (value_dependent_expression_p (TREE_OPERAND (expression, 0))
17277 || value_dependent_expression_p (TREE_OPERAND (expression, 1)));
17280 /* A CALL_EXPR may appear in a constant expression if it is a
17281 call to a builtin function, e.g., __builtin_constant_p. All
17282 such calls are value-dependent. */
17285 case NONTYPE_ARGUMENT_PACK:
17286 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
17287 is value-dependent. */
17289 tree values = ARGUMENT_PACK_ARGS (expression);
17290 int i, len = TREE_VEC_LENGTH (values);
17292 for (i = 0; i < len; ++i)
17293 if (value_dependent_expression_p (TREE_VEC_ELT (values, i)))
17301 tree type2 = TRAIT_EXPR_TYPE2 (expression);
17302 return (dependent_type_p (TRAIT_EXPR_TYPE1 (expression))
17303 || (type2 ? dependent_type_p (type2) : false));
17307 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
17308 || (value_dependent_expression_p (TREE_OPERAND (expression, 2))));
17311 /* A constant expression is value-dependent if any subexpression is
17312 value-dependent. */
17313 switch (TREE_CODE_CLASS (TREE_CODE (expression)))
17315 case tcc_reference:
17317 return (value_dependent_expression_p
17318 (TREE_OPERAND (expression, 0)));
17320 case tcc_comparison:
17322 return ((value_dependent_expression_p
17323 (TREE_OPERAND (expression, 0)))
17324 || (value_dependent_expression_p
17325 (TREE_OPERAND (expression, 1))));
17327 case tcc_expression:
17331 for (i = 0; i < TREE_OPERAND_LENGTH (expression); ++i)
17332 /* In some cases, some of the operands may be missing.
17333 (For example, in the case of PREDECREMENT_EXPR, the
17334 amount to increment by may be missing.) That doesn't
17335 make the expression dependent. */
17336 if (TREE_OPERAND (expression, i)
17337 && (value_dependent_expression_p
17338 (TREE_OPERAND (expression, i))))
17348 /* The expression is not value-dependent. */
17352 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
17353 [temp.dep.expr]. */
17356 type_dependent_expression_p (tree expression)
17358 if (!processing_template_decl)
17361 if (expression == error_mark_node)
17364 /* An unresolved name is always dependent. */
17365 if (TREE_CODE (expression) == IDENTIFIER_NODE
17366 || TREE_CODE (expression) == USING_DECL)
17369 /* Some expression forms are never type-dependent. */
17370 if (TREE_CODE (expression) == PSEUDO_DTOR_EXPR
17371 || TREE_CODE (expression) == SIZEOF_EXPR
17372 || TREE_CODE (expression) == ALIGNOF_EXPR
17373 || TREE_CODE (expression) == TRAIT_EXPR
17374 || TREE_CODE (expression) == TYPEID_EXPR
17375 || TREE_CODE (expression) == DELETE_EXPR
17376 || TREE_CODE (expression) == VEC_DELETE_EXPR
17377 || TREE_CODE (expression) == THROW_EXPR)
17380 /* The types of these expressions depends only on the type to which
17381 the cast occurs. */
17382 if (TREE_CODE (expression) == DYNAMIC_CAST_EXPR
17383 || TREE_CODE (expression) == STATIC_CAST_EXPR
17384 || TREE_CODE (expression) == CONST_CAST_EXPR
17385 || TREE_CODE (expression) == REINTERPRET_CAST_EXPR
17386 || TREE_CODE (expression) == CAST_EXPR)
17387 return dependent_type_p (TREE_TYPE (expression));
17389 /* The types of these expressions depends only on the type created
17390 by the expression. */
17391 if (TREE_CODE (expression) == NEW_EXPR
17392 || TREE_CODE (expression) == VEC_NEW_EXPR)
17394 /* For NEW_EXPR tree nodes created inside a template, either
17395 the object type itself or a TREE_LIST may appear as the
17397 tree type = TREE_OPERAND (expression, 1);
17398 if (TREE_CODE (type) == TREE_LIST)
17399 /* This is an array type. We need to check array dimensions
17401 return dependent_type_p (TREE_VALUE (TREE_PURPOSE (type)))
17402 || value_dependent_expression_p
17403 (TREE_OPERAND (TREE_VALUE (type), 1));
17405 return dependent_type_p (type);
17408 if (TREE_CODE (expression) == SCOPE_REF
17409 && dependent_scope_ref_p (expression,
17410 type_dependent_expression_p))
17413 if (TREE_CODE (expression) == FUNCTION_DECL
17414 && DECL_LANG_SPECIFIC (expression)
17415 && DECL_TEMPLATE_INFO (expression)
17416 && (any_dependent_template_arguments_p
17417 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (expression)))))
17420 if (TREE_CODE (expression) == TEMPLATE_DECL
17421 && !DECL_TEMPLATE_TEMPLATE_PARM_P (expression))
17424 if (TREE_CODE (expression) == STMT_EXPR)
17425 expression = stmt_expr_value_expr (expression);
17427 if (BRACE_ENCLOSED_INITIALIZER_P (expression))
17432 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), i, elt)
17434 if (type_dependent_expression_p (elt))
17440 if (TREE_TYPE (expression) == unknown_type_node)
17442 if (TREE_CODE (expression) == ADDR_EXPR)
17443 return type_dependent_expression_p (TREE_OPERAND (expression, 0));
17444 if (TREE_CODE (expression) == COMPONENT_REF
17445 || TREE_CODE (expression) == OFFSET_REF)
17447 if (type_dependent_expression_p (TREE_OPERAND (expression, 0)))
17449 expression = TREE_OPERAND (expression, 1);
17450 if (TREE_CODE (expression) == IDENTIFIER_NODE)
17453 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
17454 if (TREE_CODE (expression) == SCOPE_REF)
17457 if (TREE_CODE (expression) == BASELINK)
17458 expression = BASELINK_FUNCTIONS (expression);
17460 if (TREE_CODE (expression) == TEMPLATE_ID_EXPR)
17462 if (any_dependent_template_arguments_p
17463 (TREE_OPERAND (expression, 1)))
17465 expression = TREE_OPERAND (expression, 0);
17467 gcc_assert (TREE_CODE (expression) == OVERLOAD
17468 || TREE_CODE (expression) == FUNCTION_DECL);
17472 if (type_dependent_expression_p (OVL_CURRENT (expression)))
17474 expression = OVL_NEXT (expression);
17479 gcc_assert (TREE_CODE (expression) != TYPE_DECL);
17481 return (dependent_type_p (TREE_TYPE (expression)));
17484 /* Like type_dependent_expression_p, but it also works while not processing
17485 a template definition, i.e. during substitution or mangling. */
17488 type_dependent_expression_p_push (tree expr)
17491 ++processing_template_decl;
17492 b = type_dependent_expression_p (expr);
17493 --processing_template_decl;
17497 /* Returns TRUE if ARGS contains a type-dependent expression. */
17500 any_type_dependent_arguments_p (const VEC(tree,gc) *args)
17505 for (i = 0; VEC_iterate (tree, args, i, arg); ++i)
17507 if (type_dependent_expression_p (arg))
17513 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
17514 expressions) contains any value-dependent expressions. */
17517 any_value_dependent_elements_p (const_tree list)
17519 for (; list; list = TREE_CHAIN (list))
17520 if (value_dependent_expression_p (TREE_VALUE (list)))
17526 /* Returns TRUE if the ARG (a template argument) is dependent. */
17529 dependent_template_arg_p (tree arg)
17531 if (!processing_template_decl)
17534 if (TREE_CODE (arg) == TEMPLATE_DECL
17535 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
17536 return dependent_template_p (arg);
17537 else if (ARGUMENT_PACK_P (arg))
17539 tree args = ARGUMENT_PACK_ARGS (arg);
17540 int i, len = TREE_VEC_LENGTH (args);
17541 for (i = 0; i < len; ++i)
17543 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
17549 else if (TYPE_P (arg))
17550 return dependent_type_p (arg);
17552 return (type_dependent_expression_p (arg)
17553 || value_dependent_expression_p (arg));
17556 /* Returns true if ARGS (a collection of template arguments) contains
17557 any types that require structural equality testing. */
17560 any_template_arguments_need_structural_equality_p (tree args)
17567 if (args == error_mark_node)
17570 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
17572 tree level = TMPL_ARGS_LEVEL (args, i + 1);
17573 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
17575 tree arg = TREE_VEC_ELT (level, j);
17576 tree packed_args = NULL_TREE;
17579 if (ARGUMENT_PACK_P (arg))
17581 /* Look inside the argument pack. */
17582 packed_args = ARGUMENT_PACK_ARGS (arg);
17583 len = TREE_VEC_LENGTH (packed_args);
17586 for (k = 0; k < len; ++k)
17589 arg = TREE_VEC_ELT (packed_args, k);
17591 if (error_operand_p (arg))
17593 else if (TREE_CODE (arg) == TEMPLATE_DECL
17594 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
17596 else if (TYPE_P (arg) && TYPE_STRUCTURAL_EQUALITY_P (arg))
17598 else if (!TYPE_P (arg) && TREE_TYPE (arg)
17599 && TYPE_STRUCTURAL_EQUALITY_P (TREE_TYPE (arg)))
17608 /* Returns true if ARGS (a collection of template arguments) contains
17609 any dependent arguments. */
17612 any_dependent_template_arguments_p (const_tree args)
17619 if (args == error_mark_node)
17622 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
17624 const_tree level = TMPL_ARGS_LEVEL (args, i + 1);
17625 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
17626 if (dependent_template_arg_p (TREE_VEC_ELT (level, j)))
17633 /* Returns TRUE if the template TMPL is dependent. */
17636 dependent_template_p (tree tmpl)
17638 if (TREE_CODE (tmpl) == OVERLOAD)
17642 if (dependent_template_p (OVL_FUNCTION (tmpl)))
17644 tmpl = OVL_CHAIN (tmpl);
17649 /* Template template parameters are dependent. */
17650 if (DECL_TEMPLATE_TEMPLATE_PARM_P (tmpl)
17651 || TREE_CODE (tmpl) == TEMPLATE_TEMPLATE_PARM)
17653 /* So are names that have not been looked up. */
17654 if (TREE_CODE (tmpl) == SCOPE_REF
17655 || TREE_CODE (tmpl) == IDENTIFIER_NODE)
17657 /* So are member templates of dependent classes. */
17658 if (TYPE_P (CP_DECL_CONTEXT (tmpl)))
17659 return dependent_type_p (DECL_CONTEXT (tmpl));
17663 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
17666 dependent_template_id_p (tree tmpl, tree args)
17668 return (dependent_template_p (tmpl)
17669 || any_dependent_template_arguments_p (args));
17672 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
17676 dependent_omp_for_p (tree declv, tree initv, tree condv, tree incrv)
17680 if (!processing_template_decl)
17683 for (i = 0; i < TREE_VEC_LENGTH (declv); i++)
17685 tree decl = TREE_VEC_ELT (declv, i);
17686 tree init = TREE_VEC_ELT (initv, i);
17687 tree cond = TREE_VEC_ELT (condv, i);
17688 tree incr = TREE_VEC_ELT (incrv, i);
17690 if (type_dependent_expression_p (decl))
17693 if (init && type_dependent_expression_p (init))
17696 if (type_dependent_expression_p (cond))
17699 if (COMPARISON_CLASS_P (cond)
17700 && (type_dependent_expression_p (TREE_OPERAND (cond, 0))
17701 || type_dependent_expression_p (TREE_OPERAND (cond, 1))))
17704 if (TREE_CODE (incr) == MODOP_EXPR)
17706 if (type_dependent_expression_p (TREE_OPERAND (incr, 0))
17707 || type_dependent_expression_p (TREE_OPERAND (incr, 2)))
17710 else if (type_dependent_expression_p (incr))
17712 else if (TREE_CODE (incr) == MODIFY_EXPR)
17714 if (type_dependent_expression_p (TREE_OPERAND (incr, 0)))
17716 else if (BINARY_CLASS_P (TREE_OPERAND (incr, 1)))
17718 tree t = TREE_OPERAND (incr, 1);
17719 if (type_dependent_expression_p (TREE_OPERAND (t, 0))
17720 || type_dependent_expression_p (TREE_OPERAND (t, 1)))
17729 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
17730 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
17731 no such TYPE can be found. Note that this function peers inside
17732 uninstantiated templates and therefore should be used only in
17733 extremely limited situations. ONLY_CURRENT_P restricts this
17734 peering to the currently open classes hierarchy (which is required
17735 when comparing types). */
17738 resolve_typename_type (tree type, bool only_current_p)
17747 gcc_assert (TREE_CODE (type) == TYPENAME_TYPE);
17749 scope = TYPE_CONTEXT (type);
17750 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
17751 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
17752 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
17753 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
17754 identifier of the TYPENAME_TYPE anymore.
17755 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
17756 TYPENAME_TYPE instead, we avoid messing up with a possible
17757 typedef variant case. */
17758 name = TYPE_IDENTIFIER (TYPE_MAIN_VARIANT (type));
17760 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
17761 it first before we can figure out what NAME refers to. */
17762 if (TREE_CODE (scope) == TYPENAME_TYPE)
17763 scope = resolve_typename_type (scope, only_current_p);
17764 /* If we don't know what SCOPE refers to, then we cannot resolve the
17766 if (TREE_CODE (scope) == TYPENAME_TYPE)
17768 /* If the SCOPE is a template type parameter, we have no way of
17769 resolving the name. */
17770 if (TREE_CODE (scope) == TEMPLATE_TYPE_PARM)
17772 /* If the SCOPE is not the current instantiation, there's no reason
17773 to look inside it. */
17774 if (only_current_p && !currently_open_class (scope))
17776 /* If this is a typedef, we don't want to look inside (c++/11987). */
17777 if (typedef_variant_p (type))
17779 /* If SCOPE isn't the template itself, it will not have a valid
17780 TYPE_FIELDS list. */
17781 if (same_type_p (scope, CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope)))
17782 /* scope is either the template itself or a compatible instantiation
17783 like X<T>, so look up the name in the original template. */
17784 scope = CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope);
17786 /* scope is a partial instantiation, so we can't do the lookup or we
17787 will lose the template arguments. */
17789 /* Enter the SCOPE so that name lookup will be resolved as if we
17790 were in the class definition. In particular, SCOPE will no
17791 longer be considered a dependent type. */
17792 pushed_scope = push_scope (scope);
17793 /* Look up the declaration. */
17794 decl = lookup_member (scope, name, /*protect=*/0, /*want_type=*/true);
17796 result = NULL_TREE;
17798 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
17799 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
17802 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == IDENTIFIER_NODE
17803 && TREE_CODE (decl) == TYPE_DECL)
17805 result = TREE_TYPE (decl);
17806 if (result == error_mark_node)
17807 result = NULL_TREE;
17809 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == TEMPLATE_ID_EXPR
17810 && DECL_CLASS_TEMPLATE_P (decl))
17814 /* Obtain the template and the arguments. */
17815 tmpl = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 0);
17816 args = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 1);
17817 /* Instantiate the template. */
17818 result = lookup_template_class (tmpl, args, NULL_TREE, NULL_TREE,
17819 /*entering_scope=*/0,
17820 tf_error | tf_user);
17821 if (result == error_mark_node)
17822 result = NULL_TREE;
17825 /* Leave the SCOPE. */
17827 pop_scope (pushed_scope);
17829 /* If we failed to resolve it, return the original typename. */
17833 /* If lookup found a typename type, resolve that too. */
17834 if (TREE_CODE (result) == TYPENAME_TYPE && !TYPENAME_IS_RESOLVING_P (result))
17836 /* Ill-formed programs can cause infinite recursion here, so we
17837 must catch that. */
17838 TYPENAME_IS_RESOLVING_P (type) = 1;
17839 result = resolve_typename_type (result, only_current_p);
17840 TYPENAME_IS_RESOLVING_P (type) = 0;
17843 /* Qualify the resulting type. */
17844 quals = cp_type_quals (type);
17846 result = cp_build_qualified_type (result, cp_type_quals (result) | quals);
17851 /* EXPR is an expression which is not type-dependent. Return a proxy
17852 for EXPR that can be used to compute the types of larger
17853 expressions containing EXPR. */
17856 build_non_dependent_expr (tree expr)
17860 /* Preserve null pointer constants so that the type of things like
17861 "p == 0" where "p" is a pointer can be determined. */
17862 if (null_ptr_cst_p (expr))
17864 /* Preserve OVERLOADs; the functions must be available to resolve
17867 if (TREE_CODE (inner_expr) == STMT_EXPR)
17868 inner_expr = stmt_expr_value_expr (inner_expr);
17869 if (TREE_CODE (inner_expr) == ADDR_EXPR)
17870 inner_expr = TREE_OPERAND (inner_expr, 0);
17871 if (TREE_CODE (inner_expr) == COMPONENT_REF)
17872 inner_expr = TREE_OPERAND (inner_expr, 1);
17873 if (is_overloaded_fn (inner_expr)
17874 || TREE_CODE (inner_expr) == OFFSET_REF)
17876 /* There is no need to return a proxy for a variable. */
17877 if (TREE_CODE (expr) == VAR_DECL)
17879 /* Preserve string constants; conversions from string constants to
17880 "char *" are allowed, even though normally a "const char *"
17881 cannot be used to initialize a "char *". */
17882 if (TREE_CODE (expr) == STRING_CST)
17884 /* Preserve arithmetic constants, as an optimization -- there is no
17885 reason to create a new node. */
17886 if (TREE_CODE (expr) == INTEGER_CST || TREE_CODE (expr) == REAL_CST)
17888 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
17889 There is at least one place where we want to know that a
17890 particular expression is a throw-expression: when checking a ?:
17891 expression, there are special rules if the second or third
17892 argument is a throw-expression. */
17893 if (TREE_CODE (expr) == THROW_EXPR)
17896 if (TREE_CODE (expr) == COND_EXPR)
17897 return build3 (COND_EXPR,
17899 TREE_OPERAND (expr, 0),
17900 (TREE_OPERAND (expr, 1)
17901 ? build_non_dependent_expr (TREE_OPERAND (expr, 1))
17902 : build_non_dependent_expr (TREE_OPERAND (expr, 0))),
17903 build_non_dependent_expr (TREE_OPERAND (expr, 2)));
17904 if (TREE_CODE (expr) == COMPOUND_EXPR
17905 && !COMPOUND_EXPR_OVERLOADED (expr))
17906 return build2 (COMPOUND_EXPR,
17908 TREE_OPERAND (expr, 0),
17909 build_non_dependent_expr (TREE_OPERAND (expr, 1)));
17911 /* If the type is unknown, it can't really be non-dependent */
17912 gcc_assert (TREE_TYPE (expr) != unknown_type_node);
17914 /* Otherwise, build a NON_DEPENDENT_EXPR.
17916 REFERENCE_TYPEs are not stripped for expressions in templates
17917 because doing so would play havoc with mangling. Consider, for
17920 template <typename T> void f<T& g>() { g(); }
17922 In the body of "f", the expression for "g" will have
17923 REFERENCE_TYPE, even though the standard says that it should
17924 not. The reason is that we must preserve the syntactic form of
17925 the expression so that mangling (say) "f<g>" inside the body of
17926 "f" works out correctly. Therefore, the REFERENCE_TYPE is
17928 return build1 (NON_DEPENDENT_EXPR, non_reference (TREE_TYPE (expr)), expr);
17931 /* ARGS is a vector of expressions as arguments to a function call.
17932 Replace the arguments with equivalent non-dependent expressions.
17933 This modifies ARGS in place. */
17936 make_args_non_dependent (VEC(tree,gc) *args)
17941 for (ix = 0; VEC_iterate (tree, args, ix, arg); ++ix)
17943 tree newarg = build_non_dependent_expr (arg);
17945 VEC_replace (tree, args, ix, newarg);
17949 /* Returns a type which represents 'auto'. We use a TEMPLATE_TYPE_PARM
17950 with a level one deeper than the actual template parms. */
17955 tree au = cxx_make_type (TEMPLATE_TYPE_PARM);
17956 TYPE_NAME (au) = build_decl (BUILTINS_LOCATION,
17957 TYPE_DECL, get_identifier ("auto"), au);
17958 TYPE_STUB_DECL (au) = TYPE_NAME (au);
17959 TEMPLATE_TYPE_PARM_INDEX (au) = build_template_parm_index
17960 (0, processing_template_decl + 1, processing_template_decl + 1,
17961 TYPE_NAME (au), NULL_TREE);
17962 TYPE_CANONICAL (au) = canonical_type_parameter (au);
17963 DECL_ARTIFICIAL (TYPE_NAME (au)) = 1;
17964 SET_DECL_TEMPLATE_PARM_P (TYPE_NAME (au));
17969 /* Given type ARG, return std::initializer_list<ARG>. */
17974 tree std_init_list = namespace_binding
17975 (get_identifier ("initializer_list"), std_node);
17977 if (!std_init_list || !DECL_CLASS_TEMPLATE_P (std_init_list))
17979 error ("deducing from brace-enclosed initializer list requires "
17980 "#include <initializer_list>");
17981 return error_mark_node;
17983 argvec = make_tree_vec (1);
17984 TREE_VEC_ELT (argvec, 0) = arg;
17985 return lookup_template_class (std_init_list, argvec, NULL_TREE,
17986 NULL_TREE, 0, tf_warning_or_error);
17989 /* Replace auto in TYPE with std::initializer_list<auto>. */
17992 listify_autos (tree type, tree auto_node)
17994 tree init_auto = listify (auto_node);
17995 tree argvec = make_tree_vec (1);
17996 TREE_VEC_ELT (argvec, 0) = init_auto;
17997 if (processing_template_decl)
17998 argvec = add_to_template_args (current_template_args (), argvec);
17999 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
18002 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
18003 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
18006 do_auto_deduction (tree type, tree init, tree auto_node)
18008 tree parms, tparms, targs;
18012 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
18013 with either a new invented type template parameter U or, if the
18014 initializer is a braced-init-list (8.5.4), with
18015 std::initializer_list<U>. */
18016 if (BRACE_ENCLOSED_INITIALIZER_P (init))
18017 type = listify_autos (type, auto_node);
18019 parms = build_tree_list (NULL_TREE, type);
18021 tparms = make_tree_vec (1);
18022 targs = make_tree_vec (1);
18023 TREE_VEC_ELT (tparms, 0)
18024 = build_tree_list (NULL_TREE, TYPE_NAME (auto_node));
18025 val = type_unification_real (tparms, targs, parms, args, 1, 0,
18026 DEDUCE_CALL, LOOKUP_NORMAL);
18029 error ("unable to deduce %qT from %qE", type, init);
18030 return error_mark_node;
18033 /* If the list of declarators contains more than one declarator, the type
18034 of each declared variable is determined as described above. If the
18035 type deduced for the template parameter U is not the same in each
18036 deduction, the program is ill-formed. */
18037 if (TREE_TYPE (auto_node)
18038 && !same_type_p (TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0)))
18040 error ("inconsistent deduction for %qT: %qT and then %qT",
18041 auto_node, TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0));
18042 return error_mark_node;
18044 TREE_TYPE (auto_node) = TREE_VEC_ELT (targs, 0);
18046 if (processing_template_decl)
18047 targs = add_to_template_args (current_template_args (), targs);
18048 return tsubst (type, targs, tf_warning_or_error, NULL_TREE);
18051 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
18055 splice_late_return_type (tree type, tree late_return_type)
18059 if (late_return_type == NULL_TREE)
18061 argvec = make_tree_vec (1);
18062 TREE_VEC_ELT (argvec, 0) = late_return_type;
18063 if (processing_template_decl)
18064 argvec = add_to_template_args (current_template_args (), argvec);
18065 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
18068 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto'. */
18071 is_auto (const_tree type)
18073 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
18074 && TYPE_IDENTIFIER (type) == get_identifier ("auto"))
18080 /* Returns true iff TYPE contains a use of 'auto'. Since auto can only
18081 appear as a type-specifier for the declaration in question, we don't
18082 have to look through the whole type. */
18085 type_uses_auto (tree type)
18087 enum tree_code code;
18088 if (is_auto (type))
18091 code = TREE_CODE (type);
18093 if (code == POINTER_TYPE || code == REFERENCE_TYPE
18094 || code == OFFSET_TYPE || code == FUNCTION_TYPE
18095 || code == METHOD_TYPE || code == ARRAY_TYPE)
18096 return type_uses_auto (TREE_TYPE (type));
18098 if (TYPE_PTRMEMFUNC_P (type))
18099 return type_uses_auto (TREE_TYPE (TREE_TYPE
18100 (TYPE_PTRMEMFUNC_FN_TYPE (type))));
18105 /* For a given template T, return the vector of typedefs referenced
18106 in T for which access check is needed at T instantiation time.
18107 T is either a FUNCTION_DECL or a RECORD_TYPE.
18108 Those typedefs were added to T by the function
18109 append_type_to_template_for_access_check. */
18111 VEC(qualified_typedef_usage_t,gc)*
18112 get_types_needing_access_check (tree t)
18115 VEC(qualified_typedef_usage_t,gc) *result = NULL;
18117 if (!t || t == error_mark_node)
18120 if (!(ti = get_template_info (t)))
18123 if (CLASS_TYPE_P (t)
18124 || TREE_CODE (t) == FUNCTION_DECL)
18126 if (!TI_TEMPLATE (ti))
18129 result = TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti);
18135 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
18136 tied to T. That list of typedefs will be access checked at
18137 T instantiation time.
18138 T is either a FUNCTION_DECL or a RECORD_TYPE.
18139 TYPE_DECL is a TYPE_DECL node representing a typedef.
18140 SCOPE is the scope through which TYPE_DECL is accessed.
18141 LOCATION is the location of the usage point of TYPE_DECL.
18143 This function is a subroutine of
18144 append_type_to_template_for_access_check. */
18147 append_type_to_template_for_access_check_1 (tree t,
18150 location_t location)
18152 qualified_typedef_usage_t typedef_usage;
18155 if (!t || t == error_mark_node)
18158 gcc_assert ((TREE_CODE (t) == FUNCTION_DECL
18159 || CLASS_TYPE_P (t))
18161 && TREE_CODE (type_decl) == TYPE_DECL
18164 if (!(ti = get_template_info (t)))
18167 gcc_assert (TI_TEMPLATE (ti));
18169 typedef_usage.typedef_decl = type_decl;
18170 typedef_usage.context = scope;
18171 typedef_usage.locus = location;
18173 VEC_safe_push (qualified_typedef_usage_t, gc,
18174 TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti),
18178 /* Append TYPE_DECL to the template TEMPL.
18179 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
18180 At TEMPL instanciation time, TYPE_DECL will be checked to see
18181 if it can be accessed through SCOPE.
18182 LOCATION is the location of the usage point of TYPE_DECL.
18184 e.g. consider the following code snippet:
18191 template<class U> struct S
18193 C::myint mi; // <-- usage point of the typedef C::myint
18198 At S<char> instantiation time, we need to check the access of C::myint
18199 In other words, we need to check the access of the myint typedef through
18200 the C scope. For that purpose, this function will add the myint typedef
18201 and the scope C through which its being accessed to a list of typedefs
18202 tied to the template S. That list will be walked at template instantiation
18203 time and access check performed on each typedefs it contains.
18204 Note that this particular code snippet should yield an error because
18205 myint is private to C. */
18208 append_type_to_template_for_access_check (tree templ,
18211 location_t location)
18213 qualified_typedef_usage_t *iter;
18216 gcc_assert (type_decl && (TREE_CODE (type_decl) == TYPE_DECL));
18218 /* Make sure we don't append the type to the template twice. */
18220 VEC_iterate (qualified_typedef_usage_t,
18221 get_types_needing_access_check (templ),
18224 if (iter->typedef_decl == type_decl && scope == iter->context)
18227 append_type_to_template_for_access_check_1 (templ, type_decl,
18231 /* Set up the hash tables for template instantiations. */
18234 init_template_processing (void)
18236 decl_specializations = htab_create_ggc (37,
18237 hash_specialization,
18238 eq_specializations,
18240 type_specializations = htab_create_ggc (37,
18241 hash_specialization,
18242 eq_specializations,
18246 #include "gt-cp-pt.h"