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"
36 #include "pointer-set.h"
40 #include "cp-objcp-common.h"
41 #include "tree-inline.h"
48 #include "tree-iterator.h"
51 /* The type of functions taking a tree, and some additional data, and
53 typedef int (*tree_fn_t) (tree, void*);
55 /* The PENDING_TEMPLATES is a TREE_LIST of templates whose
56 instantiations have been deferred, either because their definitions
57 were not yet available, or because we were putting off doing the work. */
58 struct GTY (()) pending_template {
59 struct pending_template *next;
60 struct tinst_level *tinst;
63 static GTY(()) struct pending_template *pending_templates;
64 static GTY(()) struct pending_template *last_pending_template;
66 int processing_template_parmlist;
67 static int template_header_count;
69 static GTY(()) tree saved_trees;
70 static VEC(int,heap) *inline_parm_levels;
72 static GTY(()) struct tinst_level *current_tinst_level;
74 static GTY(()) tree saved_access_scope;
76 /* Live only within one (recursive) call to tsubst_expr. We use
77 this to pass the statement expression node from the STMT_EXPR
78 to the EXPR_STMT that is its result. */
79 static tree cur_stmt_expr;
81 /* A map from local variable declarations in the body of the template
82 presently being instantiated to the corresponding instantiated
84 static htab_t local_specializations;
86 typedef struct GTY(()) spec_entry
93 static GTY ((param_is (spec_entry)))
94 htab_t decl_specializations;
96 static GTY ((param_is (spec_entry)))
97 htab_t type_specializations;
99 /* Contains canonical template parameter types. The vector is indexed by
100 the TEMPLATE_TYPE_IDX of the template parameter. Each element is a
101 TREE_LIST, whose TREE_VALUEs contain the canonical template
102 parameters of various types and levels. */
103 static GTY(()) VEC(tree,gc) *canonical_template_parms;
105 #define UNIFY_ALLOW_NONE 0
106 #define UNIFY_ALLOW_MORE_CV_QUAL 1
107 #define UNIFY_ALLOW_LESS_CV_QUAL 2
108 #define UNIFY_ALLOW_DERIVED 4
109 #define UNIFY_ALLOW_INTEGER 8
110 #define UNIFY_ALLOW_OUTER_LEVEL 16
111 #define UNIFY_ALLOW_OUTER_MORE_CV_QUAL 32
112 #define UNIFY_ALLOW_OUTER_LESS_CV_QUAL 64
114 static void push_access_scope (tree);
115 static void pop_access_scope (tree);
116 static bool resolve_overloaded_unification (tree, tree, tree, tree,
117 unification_kind_t, int);
118 static int try_one_overload (tree, tree, tree, tree, tree,
119 unification_kind_t, int, bool);
120 static int unify (tree, tree, tree, tree, int);
121 static void add_pending_template (tree);
122 static tree reopen_tinst_level (struct tinst_level *);
123 static tree tsubst_initializer_list (tree, tree);
124 static tree get_class_bindings (tree, tree, tree);
125 static tree coerce_template_parms (tree, tree, tree, tsubst_flags_t,
127 static void tsubst_enum (tree, tree, tree);
128 static tree add_to_template_args (tree, tree);
129 static tree add_outermost_template_args (tree, tree);
130 static bool check_instantiated_args (tree, tree, tsubst_flags_t);
131 static int maybe_adjust_types_for_deduction (unification_kind_t, tree*, tree*,
133 static int type_unification_real (tree, tree, tree, const tree *,
134 unsigned int, int, unification_kind_t, int);
135 static void note_template_header (int);
136 static tree convert_nontype_argument_function (tree, tree);
137 static tree convert_nontype_argument (tree, tree);
138 static tree convert_template_argument (tree, tree, tree,
139 tsubst_flags_t, int, tree);
140 static int for_each_template_parm (tree, tree_fn_t, void*,
141 struct pointer_set_t*, bool);
142 static tree expand_template_argument_pack (tree);
143 static tree build_template_parm_index (int, int, int, tree, tree);
144 static bool inline_needs_template_parms (tree);
145 static void push_inline_template_parms_recursive (tree, int);
146 static tree retrieve_local_specialization (tree);
147 static void register_local_specialization (tree, tree);
148 static hashval_t hash_specialization (const void *p);
149 static tree reduce_template_parm_level (tree, tree, int, tree, tsubst_flags_t);
150 static int mark_template_parm (tree, void *);
151 static int template_parm_this_level_p (tree, void *);
152 static tree tsubst_friend_function (tree, tree);
153 static tree tsubst_friend_class (tree, tree);
154 static int can_complete_type_without_circularity (tree);
155 static tree get_bindings (tree, tree, tree, bool);
156 static int template_decl_level (tree);
157 static int check_cv_quals_for_unify (int, tree, tree);
158 static void template_parm_level_and_index (tree, int*, int*);
159 static int unify_pack_expansion (tree, tree, tree, tree, int, bool, bool);
160 static tree tsubst_template_arg (tree, tree, tsubst_flags_t, tree);
161 static tree tsubst_template_args (tree, tree, tsubst_flags_t, tree);
162 static tree tsubst_template_parms (tree, tree, tsubst_flags_t);
163 static void regenerate_decl_from_template (tree, tree);
164 static tree most_specialized_class (tree, tree);
165 static tree tsubst_aggr_type (tree, tree, tsubst_flags_t, tree, int);
166 static tree tsubst_arg_types (tree, tree, tsubst_flags_t, tree);
167 static tree tsubst_function_type (tree, tree, tsubst_flags_t, tree);
168 static bool check_specialization_scope (void);
169 static tree process_partial_specialization (tree);
170 static void set_current_access_from_decl (tree);
171 static tree get_template_base (tree, tree, tree, tree);
172 static tree try_class_unification (tree, tree, tree, tree);
173 static int coerce_template_template_parms (tree, tree, tsubst_flags_t,
175 static bool template_template_parm_bindings_ok_p (tree, tree);
176 static int template_args_equal (tree, tree);
177 static void tsubst_default_arguments (tree);
178 static tree for_each_template_parm_r (tree *, int *, void *);
179 static tree copy_default_args_to_explicit_spec_1 (tree, tree);
180 static void copy_default_args_to_explicit_spec (tree);
181 static int invalid_nontype_parm_type_p (tree, tsubst_flags_t);
182 static int eq_local_specializations (const void *, const void *);
183 static bool dependent_template_arg_p (tree);
184 static bool any_template_arguments_need_structural_equality_p (tree);
185 static bool dependent_type_p_r (tree);
186 static tree tsubst_expr (tree, tree, tsubst_flags_t, tree, bool);
187 static tree tsubst_copy (tree, tree, tsubst_flags_t, tree);
188 static tree tsubst_pack_expansion (tree, tree, tsubst_flags_t, tree);
189 static tree tsubst_decl (tree, tree, tsubst_flags_t);
190 static void perform_typedefs_access_check (tree tmpl, tree targs);
191 static void append_type_to_template_for_access_check_1 (tree, tree, tree,
193 static hashval_t iterative_hash_template_arg (tree arg, hashval_t val);
194 static tree listify (tree);
195 static tree listify_autos (tree, tree);
197 /* Make the current scope suitable for access checking when we are
198 processing T. T can be FUNCTION_DECL for instantiated function
199 template, or VAR_DECL for static member variable (need by
200 instantiate_decl). */
203 push_access_scope (tree t)
205 gcc_assert (TREE_CODE (t) == FUNCTION_DECL
206 || TREE_CODE (t) == VAR_DECL);
208 if (DECL_FRIEND_CONTEXT (t))
209 push_nested_class (DECL_FRIEND_CONTEXT (t));
210 else if (DECL_CLASS_SCOPE_P (t))
211 push_nested_class (DECL_CONTEXT (t));
213 push_to_top_level ();
215 if (TREE_CODE (t) == FUNCTION_DECL)
217 saved_access_scope = tree_cons
218 (NULL_TREE, current_function_decl, saved_access_scope);
219 current_function_decl = t;
223 /* Restore the scope set up by push_access_scope. T is the node we
227 pop_access_scope (tree t)
229 if (TREE_CODE (t) == FUNCTION_DECL)
231 current_function_decl = TREE_VALUE (saved_access_scope);
232 saved_access_scope = TREE_CHAIN (saved_access_scope);
235 if (DECL_FRIEND_CONTEXT (t) || DECL_CLASS_SCOPE_P (t))
238 pop_from_top_level ();
241 /* Do any processing required when DECL (a member template
242 declaration) is finished. Returns the TEMPLATE_DECL corresponding
243 to DECL, unless it is a specialization, in which case the DECL
244 itself is returned. */
247 finish_member_template_decl (tree decl)
249 if (decl == error_mark_node)
250 return error_mark_node;
252 gcc_assert (DECL_P (decl));
254 if (TREE_CODE (decl) == TYPE_DECL)
258 type = TREE_TYPE (decl);
259 if (type == error_mark_node)
260 return error_mark_node;
261 if (MAYBE_CLASS_TYPE_P (type)
262 && CLASSTYPE_TEMPLATE_INFO (type)
263 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
265 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
266 check_member_template (tmpl);
271 else if (TREE_CODE (decl) == FIELD_DECL)
272 error ("data member %qD cannot be a member template", decl);
273 else if (DECL_TEMPLATE_INFO (decl))
275 if (!DECL_TEMPLATE_SPECIALIZATION (decl))
277 check_member_template (DECL_TI_TEMPLATE (decl));
278 return DECL_TI_TEMPLATE (decl);
284 error ("invalid member template declaration %qD", decl);
286 return error_mark_node;
289 /* Create a template info node. */
292 build_template_info (tree template_decl, tree template_args)
294 tree result = make_node (TEMPLATE_INFO);
295 TI_TEMPLATE (result) = template_decl;
296 TI_ARGS (result) = template_args;
300 /* Return the template info node corresponding to T, whatever T is. */
303 get_template_info (const_tree t)
305 tree tinfo = NULL_TREE;
307 if (!t || t == error_mark_node)
310 if (DECL_P (t) && DECL_LANG_SPECIFIC (t))
311 tinfo = DECL_TEMPLATE_INFO (t);
313 if (!tinfo && DECL_IMPLICIT_TYPEDEF_P (t))
316 if (TAGGED_TYPE_P (t))
317 tinfo = TYPE_TEMPLATE_INFO (t);
318 else if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
319 tinfo = TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (t);
324 /* Returns the template nesting level of the indicated class TYPE.
334 A<T>::B<U> has depth two, while A<T> has depth one.
335 Both A<T>::B<int> and A<int>::B<U> have depth one, if
336 they are instantiations, not specializations.
338 This function is guaranteed to return 0 if passed NULL_TREE so
339 that, for example, `template_class_depth (current_class_type)' is
343 template_class_depth (tree type)
348 type && TREE_CODE (type) != NAMESPACE_DECL;
349 type = (TREE_CODE (type) == FUNCTION_DECL)
350 ? CP_DECL_CONTEXT (type) : TYPE_CONTEXT (type))
352 tree tinfo = get_template_info (type);
354 if (tinfo && PRIMARY_TEMPLATE_P (TI_TEMPLATE (tinfo))
355 && uses_template_parms (INNERMOST_TEMPLATE_ARGS (TI_ARGS (tinfo))))
362 /* Subroutine of maybe_begin_member_template_processing.
363 Returns true if processing DECL needs us to push template parms. */
366 inline_needs_template_parms (tree decl)
368 if (! DECL_TEMPLATE_INFO (decl))
371 return (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (most_general_template (decl)))
372 > (processing_template_decl + DECL_TEMPLATE_SPECIALIZATION (decl)));
375 /* Subroutine of maybe_begin_member_template_processing.
376 Push the template parms in PARMS, starting from LEVELS steps into the
377 chain, and ending at the beginning, since template parms are listed
381 push_inline_template_parms_recursive (tree parmlist, int levels)
383 tree parms = TREE_VALUE (parmlist);
387 push_inline_template_parms_recursive (TREE_CHAIN (parmlist), levels - 1);
389 ++processing_template_decl;
390 current_template_parms
391 = tree_cons (size_int (processing_template_decl),
392 parms, current_template_parms);
393 TEMPLATE_PARMS_FOR_INLINE (current_template_parms) = 1;
395 begin_scope (TREE_VEC_LENGTH (parms) ? sk_template_parms : sk_template_spec,
397 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
399 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
401 if (parm == error_mark_node)
404 gcc_assert (DECL_P (parm));
406 switch (TREE_CODE (parm))
415 /* Make a CONST_DECL as is done in process_template_parm.
416 It is ugly that we recreate this here; the original
417 version built in process_template_parm is no longer
419 tree decl = build_decl (DECL_SOURCE_LOCATION (parm),
420 CONST_DECL, DECL_NAME (parm),
422 DECL_ARTIFICIAL (decl) = 1;
423 TREE_CONSTANT (decl) = 1;
424 TREE_READONLY (decl) = 1;
425 DECL_INITIAL (decl) = DECL_INITIAL (parm);
426 SET_DECL_TEMPLATE_PARM_P (decl);
437 /* Restore the template parameter context for a member template or
438 a friend template defined in a class definition. */
441 maybe_begin_member_template_processing (tree decl)
446 if (inline_needs_template_parms (decl))
448 parms = DECL_TEMPLATE_PARMS (most_general_template (decl));
449 levels = TMPL_PARMS_DEPTH (parms) - processing_template_decl;
451 if (DECL_TEMPLATE_SPECIALIZATION (decl))
454 parms = TREE_CHAIN (parms);
457 push_inline_template_parms_recursive (parms, levels);
460 /* Remember how many levels of template parameters we pushed so that
461 we can pop them later. */
462 VEC_safe_push (int, heap, inline_parm_levels, levels);
465 /* Undo the effects of maybe_begin_member_template_processing. */
468 maybe_end_member_template_processing (void)
473 if (VEC_length (int, inline_parm_levels) == 0)
476 last = VEC_pop (int, inline_parm_levels);
477 for (i = 0; i < last; ++i)
479 --processing_template_decl;
480 current_template_parms = TREE_CHAIN (current_template_parms);
485 /* Return a new template argument vector which contains all of ARGS,
486 but has as its innermost set of arguments the EXTRA_ARGS. */
489 add_to_template_args (tree args, tree extra_args)
496 if (args == NULL_TREE)
499 extra_depth = TMPL_ARGS_DEPTH (extra_args);
500 new_args = make_tree_vec (TMPL_ARGS_DEPTH (args) + extra_depth);
502 for (i = 1; i <= TMPL_ARGS_DEPTH (args); ++i)
503 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (args, i));
505 for (j = 1; j <= extra_depth; ++j, ++i)
506 SET_TMPL_ARGS_LEVEL (new_args, i, TMPL_ARGS_LEVEL (extra_args, j));
511 /* Like add_to_template_args, but only the outermost ARGS are added to
512 the EXTRA_ARGS. In particular, all but TMPL_ARGS_DEPTH
513 (EXTRA_ARGS) levels are added. This function is used to combine
514 the template arguments from a partial instantiation with the
515 template arguments used to attain the full instantiation from the
516 partial instantiation. */
519 add_outermost_template_args (tree args, tree extra_args)
523 /* If there are more levels of EXTRA_ARGS than there are ARGS,
524 something very fishy is going on. */
525 gcc_assert (TMPL_ARGS_DEPTH (args) >= TMPL_ARGS_DEPTH (extra_args));
527 /* If *all* the new arguments will be the EXTRA_ARGS, just return
529 if (TMPL_ARGS_DEPTH (args) == TMPL_ARGS_DEPTH (extra_args))
532 /* For the moment, we make ARGS look like it contains fewer levels. */
533 TREE_VEC_LENGTH (args) -= TMPL_ARGS_DEPTH (extra_args);
535 new_args = add_to_template_args (args, extra_args);
537 /* Now, we restore ARGS to its full dimensions. */
538 TREE_VEC_LENGTH (args) += TMPL_ARGS_DEPTH (extra_args);
543 /* Return the N levels of innermost template arguments from the ARGS. */
546 get_innermost_template_args (tree args, int n)
554 /* If N is 1, just return the innermost set of template arguments. */
556 return TMPL_ARGS_LEVEL (args, TMPL_ARGS_DEPTH (args));
558 /* If we're not removing anything, just return the arguments we were
560 extra_levels = TMPL_ARGS_DEPTH (args) - n;
561 gcc_assert (extra_levels >= 0);
562 if (extra_levels == 0)
565 /* Make a new set of arguments, not containing the outer arguments. */
566 new_args = make_tree_vec (n);
567 for (i = 1; i <= n; ++i)
568 SET_TMPL_ARGS_LEVEL (new_args, i,
569 TMPL_ARGS_LEVEL (args, i + extra_levels));
574 /* The inverse of get_innermost_template_args: Return all but the innermost
575 EXTRA_LEVELS levels of template arguments from the ARGS. */
578 strip_innermost_template_args (tree args, int extra_levels)
581 int n = TMPL_ARGS_DEPTH (args) - extra_levels;
586 /* If N is 1, just return the outermost set of template arguments. */
588 return TMPL_ARGS_LEVEL (args, 1);
590 /* If we're not removing anything, just return the arguments we were
592 gcc_assert (extra_levels >= 0);
593 if (extra_levels == 0)
596 /* Make a new set of arguments, not containing the inner arguments. */
597 new_args = make_tree_vec (n);
598 for (i = 1; i <= n; ++i)
599 SET_TMPL_ARGS_LEVEL (new_args, i,
600 TMPL_ARGS_LEVEL (args, i));
605 /* We've got a template header coming up; push to a new level for storing
609 begin_template_parm_list (void)
611 /* We use a non-tag-transparent scope here, which causes pushtag to
612 put tags in this scope, rather than in the enclosing class or
613 namespace scope. This is the right thing, since we want
614 TEMPLATE_DECLS, and not TYPE_DECLS for template classes. For a
615 global template class, push_template_decl handles putting the
616 TEMPLATE_DECL into top-level scope. For a nested template class,
619 template <class T> struct S1 {
620 template <class T> struct S2 {};
623 pushtag contains special code to call pushdecl_with_scope on the
624 TEMPLATE_DECL for S2. */
625 begin_scope (sk_template_parms, NULL);
626 ++processing_template_decl;
627 ++processing_template_parmlist;
628 note_template_header (0);
631 /* This routine is called when a specialization is declared. If it is
632 invalid to declare a specialization here, an error is reported and
633 false is returned, otherwise this routine will return true. */
636 check_specialization_scope (void)
638 tree scope = current_scope ();
642 An explicit specialization shall be declared in the namespace of
643 which the template is a member, or, for member templates, in the
644 namespace of which the enclosing class or enclosing class
645 template is a member. An explicit specialization of a member
646 function, member class or static data member of a class template
647 shall be declared in the namespace of which the class template
649 if (scope && TREE_CODE (scope) != NAMESPACE_DECL)
651 error ("explicit specialization in non-namespace scope %qD", scope);
657 In an explicit specialization declaration for a member of a class
658 template or a member template that appears in namespace scope,
659 the member template and some of its enclosing class templates may
660 remain unspecialized, except that the declaration shall not
661 explicitly specialize a class member template if its enclosing
662 class templates are not explicitly specialized as well. */
663 if (current_template_parms)
665 error ("enclosing class templates are not explicitly specialized");
672 /* We've just seen template <>. */
675 begin_specialization (void)
677 begin_scope (sk_template_spec, NULL);
678 note_template_header (1);
679 return check_specialization_scope ();
682 /* Called at then end of processing a declaration preceded by
686 end_specialization (void)
689 reset_specialization ();
692 /* Any template <>'s that we have seen thus far are not referring to a
693 function specialization. */
696 reset_specialization (void)
698 processing_specialization = 0;
699 template_header_count = 0;
702 /* We've just seen a template header. If SPECIALIZATION is nonzero,
703 it was of the form template <>. */
706 note_template_header (int specialization)
708 processing_specialization = specialization;
709 template_header_count++;
712 /* We're beginning an explicit instantiation. */
715 begin_explicit_instantiation (void)
717 gcc_assert (!processing_explicit_instantiation);
718 processing_explicit_instantiation = true;
723 end_explicit_instantiation (void)
725 gcc_assert (processing_explicit_instantiation);
726 processing_explicit_instantiation = false;
729 /* An explicit specialization or partial specialization TMPL is being
730 declared. Check that the namespace in which the specialization is
731 occurring is permissible. Returns false iff it is invalid to
732 specialize TMPL in the current namespace. */
735 check_specialization_namespace (tree tmpl)
737 tree tpl_ns = decl_namespace_context (tmpl);
741 An explicit specialization shall be declared in the namespace of
742 which the template is a member, or, for member templates, in the
743 namespace of which the enclosing class or enclosing class
744 template is a member. An explicit specialization of a member
745 function, member class or static data member of a class template
746 shall be declared in the namespace of which the class template is
748 if (current_scope() != DECL_CONTEXT (tmpl)
749 && !at_namespace_scope_p ())
751 error ("specialization of %qD must appear at namespace scope", tmpl);
754 if (is_associated_namespace (current_namespace, tpl_ns))
755 /* Same or super-using namespace. */
759 permerror (input_location, "specialization of %qD in different namespace", tmpl);
760 permerror (input_location, " from definition of %q+#D", tmpl);
765 /* SPEC is an explicit instantiation. Check that it is valid to
766 perform this explicit instantiation in the current namespace. */
769 check_explicit_instantiation_namespace (tree spec)
773 /* DR 275: An explicit instantiation shall appear in an enclosing
774 namespace of its template. */
775 ns = decl_namespace_context (spec);
776 if (!is_ancestor (current_namespace, ns))
777 permerror (input_location, "explicit instantiation of %qD in namespace %qD "
778 "(which does not enclose namespace %qD)",
779 spec, current_namespace, ns);
782 /* The TYPE is being declared. If it is a template type, that means it
783 is a partial specialization. Do appropriate error-checking. */
786 maybe_process_partial_specialization (tree type)
790 if (type == error_mark_node)
791 return error_mark_node;
793 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
795 error ("name of class shadows template template parameter %qD",
797 return error_mark_node;
800 context = TYPE_CONTEXT (type);
802 if (CLASS_TYPE_P (type) && CLASSTYPE_USE_TEMPLATE (type))
804 /* This is for ordinary explicit specialization and partial
805 specialization of a template class such as:
807 template <> class C<int>;
811 template <class T> class C<T*>;
813 Make sure that `C<int>' and `C<T*>' are implicit instantiations. */
815 if (CLASSTYPE_IMPLICIT_INSTANTIATION (type)
816 && !COMPLETE_TYPE_P (type))
818 check_specialization_namespace (CLASSTYPE_TI_TEMPLATE (type));
819 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
820 if (processing_template_decl)
822 if (push_template_decl (TYPE_MAIN_DECL (type))
824 return error_mark_node;
827 else if (CLASSTYPE_TEMPLATE_INSTANTIATION (type))
828 error ("specialization of %qT after instantiation", type);
830 else if (CLASS_TYPE_P (type)
831 && !CLASSTYPE_USE_TEMPLATE (type)
832 && CLASSTYPE_TEMPLATE_INFO (type)
833 && context && CLASS_TYPE_P (context)
834 && CLASSTYPE_TEMPLATE_INFO (context))
836 /* This is for an explicit specialization of member class
837 template according to [temp.expl.spec/18]:
839 template <> template <class U> class C<int>::D;
841 The context `C<int>' must be an implicit instantiation.
842 Otherwise this is just a member class template declared
845 template <> class C<int> { template <class U> class D; };
846 template <> template <class U> class C<int>::D;
848 In the first case, `C<int>::D' is a specialization of `C<T>::D'
849 while in the second case, `C<int>::D' is a primary template
850 and `C<T>::D' may not exist. */
852 if (CLASSTYPE_IMPLICIT_INSTANTIATION (context)
853 && !COMPLETE_TYPE_P (type))
856 tree tmpl = CLASSTYPE_TI_TEMPLATE (type);
858 if (current_namespace
859 != decl_namespace_context (tmpl))
861 permerror (input_location, "specializing %q#T in different namespace", type);
862 permerror (input_location, " from definition of %q+#D", tmpl);
865 /* Check for invalid specialization after instantiation:
867 template <> template <> class C<int>::D<int>;
868 template <> template <class U> class C<int>::D; */
870 for (t = DECL_TEMPLATE_INSTANTIATIONS (tmpl);
871 t; t = TREE_CHAIN (t))
873 tree inst = TREE_VALUE (t);
874 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (inst))
876 /* We already have a full specialization of this partial
877 instantiation. Reassign it to the new member
878 specialization template. */
882 elt.tmpl = most_general_template (tmpl);
883 elt.args = CLASSTYPE_TI_ARGS (inst);
886 htab_remove_elt (type_specializations, &elt);
889 elt.args = INNERMOST_TEMPLATE_ARGS (elt.args);
891 slot = (spec_entry **)
892 htab_find_slot (type_specializations, &elt, INSERT);
893 *slot = GGC_NEW (spec_entry);
896 else if (COMPLETE_TYPE_P (inst) || TYPE_BEING_DEFINED (inst))
897 /* But if we've had an implicit instantiation, that's a
898 problem ([temp.expl.spec]/6). */
899 error ("specialization %qT after instantiation %qT",
903 /* Mark TYPE as a specialization. And as a result, we only
904 have one level of template argument for the innermost
906 SET_CLASSTYPE_TEMPLATE_SPECIALIZATION (type);
907 CLASSTYPE_TI_ARGS (type)
908 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type));
911 else if (processing_specialization)
913 error ("explicit specialization of non-template %qT", type);
914 return error_mark_node;
920 /* Returns nonzero if we can optimize the retrieval of specializations
921 for TMPL, a TEMPLATE_DECL. In particular, for such a template, we
922 do not use DECL_TEMPLATE_SPECIALIZATIONS at all. */
925 optimize_specialization_lookup_p (tree tmpl)
927 return (DECL_FUNCTION_TEMPLATE_P (tmpl)
928 && DECL_CLASS_SCOPE_P (tmpl)
929 /* DECL_CLASS_SCOPE_P holds of T::f even if T is a template
931 && CLASS_TYPE_P (DECL_CONTEXT (tmpl))
932 /* The optimized lookup depends on the fact that the
933 template arguments for the member function template apply
934 purely to the containing class, which is not true if the
935 containing class is an explicit or partial
937 && !CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (tmpl))
938 && !DECL_MEMBER_TEMPLATE_P (tmpl)
939 && !DECL_CONV_FN_P (tmpl)
940 /* It is possible to have a template that is not a member
941 template and is not a member of a template class:
943 template <typename T>
944 struct S { friend A::f(); };
946 Here, the friend function is a template, but the context does
947 not have template information. The optimized lookup relies
948 on having ARGS be the template arguments for both the class
949 and the function template. */
950 && !DECL_FRIEND_P (DECL_TEMPLATE_RESULT (tmpl)));
953 /* Retrieve the specialization (in the sense of [temp.spec] - a
954 specialization is either an instantiation or an explicit
955 specialization) of TMPL for the given template ARGS. If there is
956 no such specialization, return NULL_TREE. The ARGS are a vector of
957 arguments, or a vector of vectors of arguments, in the case of
958 templates with more than one level of parameters.
960 If TMPL is a type template and CLASS_SPECIALIZATIONS_P is true,
961 then we search for a partial specialization matching ARGS. This
962 parameter is ignored if TMPL is not a class template. */
965 retrieve_specialization (tree tmpl, tree args, hashval_t hash)
967 if (args == error_mark_node)
970 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
972 /* There should be as many levels of arguments as there are
973 levels of parameters. */
974 gcc_assert (TMPL_ARGS_DEPTH (args)
975 == TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl)));
977 if (optimize_specialization_lookup_p (tmpl))
980 tree class_specialization;
981 VEC(tree,gc) *methods;
985 /* The template arguments actually apply to the containing
986 class. Find the class specialization with those
988 class_template = CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (tmpl));
990 = retrieve_specialization (class_template, args, 0);
991 if (!class_specialization)
993 /* Now, find the appropriate entry in the CLASSTYPE_METHOD_VEC
994 for the specialization. */
995 idx = class_method_index_for_fn (class_specialization, tmpl);
998 /* Iterate through the methods with the indicated name, looking
999 for the one that has an instance of TMPL. */
1000 methods = CLASSTYPE_METHOD_VEC (class_specialization);
1001 for (fns = VEC_index (tree, methods, idx); fns; fns = OVL_NEXT (fns))
1003 tree fn = OVL_CURRENT (fns);
1004 if (DECL_TEMPLATE_INFO (fn) && DECL_TI_TEMPLATE (fn) == tmpl
1005 /* using-declarations can add base methods to the method vec,
1006 and we don't want those here. */
1007 && DECL_CONTEXT (fn) == class_specialization)
1016 htab_t specializations;
1020 elt.spec = NULL_TREE;
1022 if (DECL_CLASS_TEMPLATE_P (tmpl))
1023 specializations = type_specializations;
1025 specializations = decl_specializations;
1028 hash = hash_specialization (&elt);
1029 found = (spec_entry *) htab_find_with_hash (specializations, &elt, hash);
1037 /* Like retrieve_specialization, but for local declarations. */
1040 retrieve_local_specialization (tree tmpl)
1044 if (local_specializations == NULL)
1047 spec = (tree) htab_find_with_hash (local_specializations, tmpl,
1048 htab_hash_pointer (tmpl));
1049 return spec ? TREE_PURPOSE (spec) : NULL_TREE;
1052 /* Returns nonzero iff DECL is a specialization of TMPL. */
1055 is_specialization_of (tree decl, tree tmpl)
1059 if (TREE_CODE (decl) == FUNCTION_DECL)
1063 t = DECL_TEMPLATE_INFO (t) ? DECL_TI_TEMPLATE (t) : NULL_TREE)
1069 gcc_assert (TREE_CODE (decl) == TYPE_DECL);
1071 for (t = TREE_TYPE (decl);
1073 t = CLASSTYPE_USE_TEMPLATE (t)
1074 ? TREE_TYPE (CLASSTYPE_TI_TEMPLATE (t)) : NULL_TREE)
1075 if (same_type_ignoring_top_level_qualifiers_p (t, TREE_TYPE (tmpl)))
1082 /* Returns nonzero iff DECL is a specialization of friend declaration
1083 FRIEND_DECL according to [temp.friend]. */
1086 is_specialization_of_friend (tree decl, tree friend_decl)
1088 bool need_template = true;
1091 gcc_assert (TREE_CODE (decl) == FUNCTION_DECL
1092 || TREE_CODE (decl) == TYPE_DECL);
1094 /* For [temp.friend/6] when FRIEND_DECL is an ordinary member function
1095 of a template class, we want to check if DECL is a specialization
1097 if (TREE_CODE (friend_decl) == FUNCTION_DECL
1098 && DECL_TEMPLATE_INFO (friend_decl)
1099 && !DECL_USE_TEMPLATE (friend_decl))
1101 /* We want a TEMPLATE_DECL for `is_specialization_of'. */
1102 friend_decl = DECL_TI_TEMPLATE (friend_decl);
1103 need_template = false;
1105 else if (TREE_CODE (friend_decl) == TEMPLATE_DECL
1106 && !PRIMARY_TEMPLATE_P (friend_decl))
1107 need_template = false;
1109 /* There is nothing to do if this is not a template friend. */
1110 if (TREE_CODE (friend_decl) != TEMPLATE_DECL)
1113 if (is_specialization_of (decl, friend_decl))
1117 A member of a class template may be declared to be a friend of a
1118 non-template class. In this case, the corresponding member of
1119 every specialization of the class template is a friend of the
1120 class granting friendship.
1122 For example, given a template friend declaration
1124 template <class T> friend void A<T>::f();
1126 the member function below is considered a friend
1128 template <> struct A<int> {
1132 For this type of template friend, TEMPLATE_DEPTH below will be
1133 nonzero. To determine if DECL is a friend of FRIEND, we first
1134 check if the enclosing class is a specialization of another. */
1136 template_depth = template_class_depth (DECL_CONTEXT (friend_decl));
1138 && DECL_CLASS_SCOPE_P (decl)
1139 && is_specialization_of (TYPE_NAME (DECL_CONTEXT (decl)),
1140 CLASSTYPE_TI_TEMPLATE (DECL_CONTEXT (friend_decl))))
1142 /* Next, we check the members themselves. In order to handle
1143 a few tricky cases, such as when FRIEND_DECL's are
1145 template <class T> friend void A<T>::g(T t);
1146 template <class T> template <T t> friend void A<T>::h();
1150 void A<int>::g(int);
1151 template <int> void A<int>::h();
1153 we need to figure out ARGS, the template arguments from
1154 the context of DECL. This is required for template substitution
1155 of `T' in the function parameter of `g' and template parameter
1156 of `h' in the above examples. Here ARGS corresponds to `int'. */
1158 tree context = DECL_CONTEXT (decl);
1159 tree args = NULL_TREE;
1160 int current_depth = 0;
1162 while (current_depth < template_depth)
1164 if (CLASSTYPE_TEMPLATE_INFO (context))
1166 if (current_depth == 0)
1167 args = TYPE_TI_ARGS (context);
1169 args = add_to_template_args (TYPE_TI_ARGS (context), args);
1172 context = TYPE_CONTEXT (context);
1175 if (TREE_CODE (decl) == FUNCTION_DECL)
1180 tree friend_args_type;
1181 tree decl_args_type;
1183 /* Make sure that both DECL and FRIEND_DECL are templates or
1185 is_template = DECL_TEMPLATE_INFO (decl)
1186 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (decl));
1187 if (need_template ^ is_template)
1189 else if (is_template)
1191 /* If both are templates, check template parameter list. */
1193 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1195 if (!comp_template_parms
1196 (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (decl)),
1200 decl_type = TREE_TYPE (DECL_TI_TEMPLATE (decl));
1203 decl_type = TREE_TYPE (decl);
1205 friend_type = tsubst_function_type (TREE_TYPE (friend_decl), args,
1206 tf_none, NULL_TREE);
1207 if (friend_type == error_mark_node)
1210 /* Check if return types match. */
1211 if (!same_type_p (TREE_TYPE (decl_type), TREE_TYPE (friend_type)))
1214 /* Check if function parameter types match, ignoring the
1215 `this' parameter. */
1216 friend_args_type = TYPE_ARG_TYPES (friend_type);
1217 decl_args_type = TYPE_ARG_TYPES (decl_type);
1218 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (friend_decl))
1219 friend_args_type = TREE_CHAIN (friend_args_type);
1220 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1221 decl_args_type = TREE_CHAIN (decl_args_type);
1223 return compparms (decl_args_type, friend_args_type);
1227 /* DECL is a TYPE_DECL */
1229 tree decl_type = TREE_TYPE (decl);
1231 /* Make sure that both DECL and FRIEND_DECL are templates or
1234 = CLASSTYPE_TEMPLATE_INFO (decl_type)
1235 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (decl_type));
1237 if (need_template ^ is_template)
1239 else if (is_template)
1242 /* If both are templates, check the name of the two
1243 TEMPLATE_DECL's first because is_friend didn't. */
1244 if (DECL_NAME (CLASSTYPE_TI_TEMPLATE (decl_type))
1245 != DECL_NAME (friend_decl))
1248 /* Now check template parameter list. */
1250 = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_decl),
1252 return comp_template_parms
1253 (DECL_TEMPLATE_PARMS (CLASSTYPE_TI_TEMPLATE (decl_type)),
1257 return (DECL_NAME (decl)
1258 == DECL_NAME (friend_decl));
1264 /* Register the specialization SPEC as a specialization of TMPL with
1265 the indicated ARGS. IS_FRIEND indicates whether the specialization
1266 is actually just a friend declaration. Returns SPEC, or an
1267 equivalent prior declaration, if available. */
1270 register_specialization (tree spec, tree tmpl, tree args, bool is_friend,
1274 spec_entry **slot = NULL;
1277 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL && DECL_P (spec));
1279 if (TREE_CODE (spec) == FUNCTION_DECL
1280 && uses_template_parms (DECL_TI_ARGS (spec)))
1281 /* This is the FUNCTION_DECL for a partial instantiation. Don't
1282 register it; we want the corresponding TEMPLATE_DECL instead.
1283 We use `uses_template_parms (DECL_TI_ARGS (spec))' rather than
1284 the more obvious `uses_template_parms (spec)' to avoid problems
1285 with default function arguments. In particular, given
1286 something like this:
1288 template <class T> void f(T t1, T t = T())
1290 the default argument expression is not substituted for in an
1291 instantiation unless and until it is actually needed. */
1294 if (optimize_specialization_lookup_p (tmpl))
1295 /* We don't put these specializations in the hash table, but we might
1296 want to give an error about a mismatch. */
1297 fn = retrieve_specialization (tmpl, args, 0);
1305 hash = hash_specialization (&elt);
1307 slot = (spec_entry **)
1308 htab_find_slot_with_hash (decl_specializations, &elt, hash, INSERT);
1315 /* We can sometimes try to re-register a specialization that we've
1316 already got. In particular, regenerate_decl_from_template calls
1317 duplicate_decls which will update the specialization list. But,
1318 we'll still get called again here anyhow. It's more convenient
1319 to simply allow this than to try to prevent it. */
1322 else if (fn && DECL_TEMPLATE_SPECIALIZATION (spec))
1324 if (DECL_TEMPLATE_INSTANTIATION (fn))
1326 if (DECL_ODR_USED (fn)
1327 || DECL_EXPLICIT_INSTANTIATION (fn))
1329 error ("specialization of %qD after instantiation",
1331 return error_mark_node;
1336 /* This situation should occur only if the first
1337 specialization is an implicit instantiation, the
1338 second is an explicit specialization, and the
1339 implicit instantiation has not yet been used. That
1340 situation can occur if we have implicitly
1341 instantiated a member function and then specialized
1344 We can also wind up here if a friend declaration that
1345 looked like an instantiation turns out to be a
1348 template <class T> void foo(T);
1349 class S { friend void foo<>(int) };
1350 template <> void foo(int);
1352 We transform the existing DECL in place so that any
1353 pointers to it become pointers to the updated
1356 If there was a definition for the template, but not
1357 for the specialization, we want this to look as if
1358 there were no definition, and vice versa. */
1359 DECL_INITIAL (fn) = NULL_TREE;
1360 duplicate_decls (spec, fn, is_friend);
1361 /* The call to duplicate_decls will have applied
1364 An explicit specialization of a function template
1365 is inline only if it is explicitly declared to be,
1366 and independently of whether its function template
1369 to the primary function; now copy the inline bits to
1370 the various clones. */
1371 FOR_EACH_CLONE (clone, fn)
1373 DECL_DECLARED_INLINE_P (clone)
1374 = DECL_DECLARED_INLINE_P (fn);
1375 DECL_SOURCE_LOCATION (clone)
1376 = DECL_SOURCE_LOCATION (fn);
1378 check_specialization_namespace (fn);
1383 else if (DECL_TEMPLATE_SPECIALIZATION (fn))
1385 if (!duplicate_decls (spec, fn, is_friend) && DECL_INITIAL (spec))
1386 /* Dup decl failed, but this is a new definition. Set the
1387 line number so any errors match this new
1389 DECL_SOURCE_LOCATION (fn) = DECL_SOURCE_LOCATION (spec);
1395 return duplicate_decls (spec, fn, is_friend);
1397 /* A specialization must be declared in the same namespace as the
1398 template it is specializing. */
1399 if (DECL_TEMPLATE_SPECIALIZATION (spec)
1400 && !check_specialization_namespace (tmpl))
1401 DECL_CONTEXT (spec) = DECL_CONTEXT (tmpl);
1403 if (!optimize_specialization_lookup_p (tmpl))
1405 gcc_assert (tmpl && args && spec);
1406 *slot = GGC_NEW (spec_entry);
1408 if (TREE_CODE (spec) == FUNCTION_DECL && DECL_NAMESPACE_SCOPE_P (spec)
1409 && PRIMARY_TEMPLATE_P (tmpl)
1410 && DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (tmpl)) == NULL_TREE)
1411 /* TMPL is a forward declaration of a template function; keep a list
1412 of all specializations in case we need to reassign them to a friend
1413 template later in tsubst_friend_function. */
1414 DECL_TEMPLATE_INSTANTIATIONS (tmpl)
1415 = tree_cons (args, spec, DECL_TEMPLATE_INSTANTIATIONS (tmpl));
1421 /* Returns true iff two spec_entry nodes are equivalent. Only compares the
1422 TMPL and ARGS members, ignores SPEC. */
1425 eq_specializations (const void *p1, const void *p2)
1427 const spec_entry *e1 = (const spec_entry *)p1;
1428 const spec_entry *e2 = (const spec_entry *)p2;
1430 return (e1->tmpl == e2->tmpl
1431 && comp_template_args (e1->args, e2->args));
1434 /* Returns a hash for a template TMPL and template arguments ARGS. */
1437 hash_tmpl_and_args (tree tmpl, tree args)
1439 hashval_t val = DECL_UID (tmpl);
1440 return iterative_hash_template_arg (args, val);
1443 /* Returns a hash for a spec_entry node based on the TMPL and ARGS members,
1447 hash_specialization (const void *p)
1449 const spec_entry *e = (const spec_entry *)p;
1450 return hash_tmpl_and_args (e->tmpl, e->args);
1453 /* Recursively calculate a hash value for a template argument ARG, for use
1454 in the hash tables of template specializations. */
1457 iterative_hash_template_arg (tree arg, hashval_t val)
1459 unsigned HOST_WIDE_INT i;
1460 enum tree_code code;
1463 if (arg == NULL_TREE)
1464 return iterative_hash_object (arg, val);
1469 if (TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
1470 /* We can get one of these when re-hashing a previous entry in the middle
1471 of substituting into a pack expansion. Just look through it. */
1472 arg = ARGUMENT_PACK_SELECT_FROM_PACK (arg);
1474 code = TREE_CODE (arg);
1475 tclass = TREE_CODE_CLASS (code);
1477 val = iterative_hash_object (code, val);
1484 case IDENTIFIER_NODE:
1485 return iterative_hash_object (IDENTIFIER_HASH_VALUE (arg), val);
1489 int i, len = TREE_VEC_LENGTH (arg);
1490 for (i = 0; i < len; ++i)
1491 val = iterative_hash_template_arg (TREE_VEC_ELT (arg, i), val);
1495 case TYPE_PACK_EXPANSION:
1496 case EXPR_PACK_EXPANSION:
1497 return iterative_hash_template_arg (PACK_EXPANSION_PATTERN (arg), val);
1499 case TYPE_ARGUMENT_PACK:
1500 case NONTYPE_ARGUMENT_PACK:
1501 return iterative_hash_template_arg (ARGUMENT_PACK_ARGS (arg), val);
1504 for (; arg; arg = TREE_CHAIN (arg))
1505 val = iterative_hash_template_arg (TREE_VALUE (arg), val);
1509 for (; arg; arg = OVL_CHAIN (arg))
1510 val = iterative_hash_template_arg (OVL_FUNCTION (arg), val);
1516 FOR_EACH_CONSTRUCTOR_ELT (CONSTRUCTOR_ELTS (arg), i, field, value)
1518 val = iterative_hash_template_arg (field, val);
1519 val = iterative_hash_template_arg (value, val);
1525 if (!DECL_ARTIFICIAL (arg))
1526 val = iterative_hash_object (DECL_PARM_INDEX (arg), val);
1527 return iterative_hash_template_arg (TREE_TYPE (arg), val);
1530 return iterative_hash_template_arg (TARGET_EXPR_INITIAL (arg), val);
1533 val = iterative_hash_template_arg (PTRMEM_CST_CLASS (arg), val);
1534 return iterative_hash_template_arg (PTRMEM_CST_MEMBER (arg), val);
1536 case TEMPLATE_PARM_INDEX:
1537 val = iterative_hash_template_arg
1538 (TREE_TYPE (TEMPLATE_PARM_DECL (arg)), val);
1539 val = iterative_hash_object (TEMPLATE_PARM_LEVEL (arg), val);
1540 return iterative_hash_object (TEMPLATE_PARM_IDX (arg), val);
1543 val = iterative_hash_object (TRAIT_EXPR_KIND (arg), val);
1544 val = iterative_hash_template_arg (TRAIT_EXPR_TYPE1 (arg), val);
1545 return iterative_hash_template_arg (TRAIT_EXPR_TYPE2 (arg), val);
1548 val = iterative_hash_template_arg (BINFO_TYPE (BASELINK_BINFO (arg)),
1550 return iterative_hash_template_arg (DECL_NAME (get_first_fn (arg)),
1554 val = iterative_hash_template_arg (TREE_OPERAND (arg, 0), val);
1555 code = TREE_CODE (TREE_OPERAND (arg, 1));
1556 val = iterative_hash_object (code, val);
1557 return iterative_hash_template_arg (TREE_OPERAND (arg, 2), val);
1560 /* layout_type sets structural equality for arrays of
1561 incomplete type, so we can't rely on the canonical type
1563 val = iterative_hash_template_arg (TREE_TYPE (arg), val);
1564 return iterative_hash_template_arg (TYPE_DOMAIN (arg), val);
1570 if (TYPE_CANONICAL (arg))
1571 return iterative_hash_object (TYPE_HASH (TYPE_CANONICAL (arg)),
1573 else if (TREE_CODE (arg) == DECLTYPE_TYPE)
1574 return iterative_hash_template_arg (DECLTYPE_TYPE_EXPR (arg), val);
1575 /* Otherwise just compare the types during lookup. */
1578 case tcc_declaration:
1580 return iterative_hash_expr (arg, val);
1583 gcc_assert (IS_EXPR_CODE_CLASS (tclass));
1585 unsigned n = TREE_OPERAND_LENGTH (arg);
1586 for (i = 0; i < n; ++i)
1587 val = iterative_hash_template_arg (TREE_OPERAND (arg, i), val);
1596 /* Unregister the specialization SPEC as a specialization of TMPL.
1597 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1598 if the SPEC was listed as a specialization of TMPL.
1600 Note that SPEC has been ggc_freed, so we can't look inside it. */
1603 reregister_specialization (tree spec, tree tinfo, tree new_spec)
1608 elt.tmpl = most_general_template (TI_TEMPLATE (tinfo));
1609 elt.args = TI_ARGS (tinfo);
1610 elt.spec = NULL_TREE;
1612 slot = (spec_entry **) htab_find_slot (decl_specializations, &elt, INSERT);
1615 gcc_assert ((*slot)->spec == spec || (*slot)->spec == new_spec);
1616 gcc_assert (new_spec != NULL_TREE);
1617 (*slot)->spec = new_spec;
1624 /* Compare an entry in the local specializations hash table P1 (which
1625 is really a pointer to a TREE_LIST) with P2 (which is really a
1629 eq_local_specializations (const void *p1, const void *p2)
1631 return TREE_VALUE ((const_tree) p1) == (const_tree) p2;
1634 /* Hash P1, an entry in the local specializations table. */
1637 hash_local_specialization (const void* p1)
1639 return htab_hash_pointer (TREE_VALUE ((const_tree) p1));
1642 /* Like register_specialization, but for local declarations. We are
1643 registering SPEC, an instantiation of TMPL. */
1646 register_local_specialization (tree spec, tree tmpl)
1650 slot = htab_find_slot_with_hash (local_specializations, tmpl,
1651 htab_hash_pointer (tmpl), INSERT);
1652 *slot = build_tree_list (spec, tmpl);
1655 /* TYPE is a class type. Returns true if TYPE is an explicitly
1656 specialized class. */
1659 explicit_class_specialization_p (tree type)
1661 if (!CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
1663 return !uses_template_parms (CLASSTYPE_TI_ARGS (type));
1666 /* Print the list of functions at FNS, going through all the overloads
1667 for each element of the list. Alternatively, FNS can not be a
1668 TREE_LIST, in which case it will be printed together with all the
1671 MORE and *STR should respectively be FALSE and NULL when the function
1672 is called from the outside. They are used internally on recursive
1673 calls. print_candidates manages the two parameters and leaves NULL
1674 in *STR when it ends. */
1677 print_candidates_1 (tree fns, bool more, const char **str)
1680 char *spaces = NULL;
1682 for (fn = fns; fn; fn = OVL_NEXT (fn))
1683 if (TREE_CODE (fn) == TREE_LIST)
1685 gcc_assert (!OVL_NEXT (fn) && !is_overloaded_fn (fn));
1686 for (fn2 = fn; fn2 != NULL_TREE; fn2 = TREE_CHAIN (fn2))
1687 print_candidates_1 (TREE_VALUE (fn2),
1688 TREE_CHAIN (fn2) || more, str);
1694 /* Pick the prefix string. */
1695 if (!more && !OVL_NEXT (fns))
1697 error ("candidate is: %+#D", OVL_CURRENT (fn));
1701 *str = _("candidates are:");
1702 spaces = get_spaces (*str);
1704 error ("%s %+#D", *str, OVL_CURRENT (fn));
1705 *str = spaces ? spaces : *str;
1715 /* Print the list of candidate FNS in an error message. */
1718 print_candidates (tree fns)
1720 const char *str = NULL;
1721 print_candidates_1 (fns, false, &str);
1722 gcc_assert (str == NULL);
1725 /* Returns the template (one of the functions given by TEMPLATE_ID)
1726 which can be specialized to match the indicated DECL with the
1727 explicit template args given in TEMPLATE_ID. The DECL may be
1728 NULL_TREE if none is available. In that case, the functions in
1729 TEMPLATE_ID are non-members.
1731 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1732 specialization of a member template.
1734 The TEMPLATE_COUNT is the number of references to qualifying
1735 template classes that appeared in the name of the function. See
1736 check_explicit_specialization for a more accurate description.
1738 TSK indicates what kind of template declaration (if any) is being
1739 declared. TSK_TEMPLATE indicates that the declaration given by
1740 DECL, though a FUNCTION_DECL, has template parameters, and is
1741 therefore a template function.
1743 The template args (those explicitly specified and those deduced)
1744 are output in a newly created vector *TARGS_OUT.
1746 If it is impossible to determine the result, an error message is
1747 issued. The error_mark_node is returned to indicate failure. */
1750 determine_specialization (tree template_id,
1753 int need_member_template,
1759 tree explicit_targs;
1760 tree candidates = NULL_TREE;
1761 /* A TREE_LIST of templates of which DECL may be a specialization.
1762 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1763 corresponding TREE_PURPOSE is the set of template arguments that,
1764 when used to instantiate the template, would produce a function
1765 with the signature of DECL. */
1766 tree templates = NULL_TREE;
1768 struct cp_binding_level *b;
1770 *targs_out = NULL_TREE;
1772 if (template_id == error_mark_node || decl == error_mark_node)
1773 return error_mark_node;
1775 fns = TREE_OPERAND (template_id, 0);
1776 explicit_targs = TREE_OPERAND (template_id, 1);
1778 if (fns == error_mark_node)
1779 return error_mark_node;
1781 /* Check for baselinks. */
1782 if (BASELINK_P (fns))
1783 fns = BASELINK_FUNCTIONS (fns);
1785 if (!is_overloaded_fn (fns))
1787 error ("%qD is not a function template", fns);
1788 return error_mark_node;
1791 /* Count the number of template headers specified for this
1794 for (b = current_binding_level;
1795 b->kind == sk_template_parms;
1799 for (; fns; fns = OVL_NEXT (fns))
1801 tree fn = OVL_CURRENT (fns);
1803 if (TREE_CODE (fn) == TEMPLATE_DECL)
1805 tree decl_arg_types;
1808 /* In case of explicit specialization, we need to check if
1809 the number of template headers appearing in the specialization
1810 is correct. This is usually done in check_explicit_specialization,
1811 but the check done there cannot be exhaustive when specializing
1812 member functions. Consider the following code:
1814 template <> void A<int>::f(int);
1815 template <> template <> void A<int>::f(int);
1817 Assuming that A<int> is not itself an explicit specialization
1818 already, the first line specializes "f" which is a non-template
1819 member function, whilst the second line specializes "f" which
1820 is a template member function. So both lines are syntactically
1821 correct, and check_explicit_specialization does not reject
1824 Here, we can do better, as we are matching the specialization
1825 against the declarations. We count the number of template
1826 headers, and we check if they match TEMPLATE_COUNT + 1
1827 (TEMPLATE_COUNT is the number of qualifying template classes,
1828 plus there must be another header for the member template
1831 Notice that if header_count is zero, this is not a
1832 specialization but rather a template instantiation, so there
1833 is no check we can perform here. */
1834 if (header_count && header_count != template_count + 1)
1837 /* Check that the number of template arguments at the
1838 innermost level for DECL is the same as for FN. */
1839 if (current_binding_level->kind == sk_template_parms
1840 && !current_binding_level->explicit_spec_p
1841 && (TREE_VEC_LENGTH (DECL_INNERMOST_TEMPLATE_PARMS (fn))
1842 != TREE_VEC_LENGTH (INNERMOST_TEMPLATE_PARMS
1843 (current_template_parms))))
1846 /* DECL might be a specialization of FN. */
1847 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1848 fn_arg_types = TYPE_ARG_TYPES (TREE_TYPE (fn));
1850 /* For a non-static member function, we need to make sure
1851 that the const qualification is the same. Since
1852 get_bindings does not try to merge the "this" parameter,
1853 we must do the comparison explicitly. */
1854 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
1855 && !same_type_p (TREE_VALUE (fn_arg_types),
1856 TREE_VALUE (decl_arg_types)))
1859 /* Skip the "this" parameter and, for constructors of
1860 classes with virtual bases, the VTT parameter. A
1861 full specialization of a constructor will have a VTT
1862 parameter, but a template never will. */
1864 = skip_artificial_parms_for (decl, decl_arg_types);
1866 = skip_artificial_parms_for (fn, fn_arg_types);
1868 /* Check that the number of function parameters matches.
1870 template <class T> void f(int i = 0);
1871 template <> void f<int>();
1872 The specialization f<int> is invalid but is not caught
1873 by get_bindings below. */
1874 if (list_length (fn_arg_types) != list_length (decl_arg_types))
1877 /* Function templates cannot be specializations; there are
1878 no partial specializations of functions. Therefore, if
1879 the type of DECL does not match FN, there is no
1881 if (tsk == tsk_template)
1883 if (compparms (fn_arg_types, decl_arg_types))
1884 candidates = tree_cons (NULL_TREE, fn, candidates);
1888 /* See whether this function might be a specialization of this
1890 targs = get_bindings (fn, decl, explicit_targs, /*check_ret=*/true);
1893 /* We cannot deduce template arguments that when used to
1894 specialize TMPL will produce DECL. */
1897 /* Save this template, and the arguments deduced. */
1898 templates = tree_cons (targs, fn, templates);
1900 else if (need_member_template)
1901 /* FN is an ordinary member function, and we need a
1902 specialization of a member template. */
1904 else if (TREE_CODE (fn) != FUNCTION_DECL)
1905 /* We can get IDENTIFIER_NODEs here in certain erroneous
1908 else if (!DECL_FUNCTION_MEMBER_P (fn))
1909 /* This is just an ordinary non-member function. Nothing can
1910 be a specialization of that. */
1912 else if (DECL_ARTIFICIAL (fn))
1913 /* Cannot specialize functions that are created implicitly. */
1917 tree decl_arg_types;
1919 /* This is an ordinary member function. However, since
1920 we're here, we can assume it's enclosing class is a
1921 template class. For example,
1923 template <typename T> struct S { void f(); };
1924 template <> void S<int>::f() {}
1926 Here, S<int>::f is a non-template, but S<int> is a
1927 template class. If FN has the same type as DECL, we
1928 might be in business. */
1930 if (!DECL_TEMPLATE_INFO (fn))
1931 /* Its enclosing class is an explicit specialization
1932 of a template class. This is not a candidate. */
1935 if (!same_type_p (TREE_TYPE (TREE_TYPE (decl)),
1936 TREE_TYPE (TREE_TYPE (fn))))
1937 /* The return types differ. */
1940 /* Adjust the type of DECL in case FN is a static member. */
1941 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1942 if (DECL_STATIC_FUNCTION_P (fn)
1943 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1944 decl_arg_types = TREE_CHAIN (decl_arg_types);
1946 if (compparms (TYPE_ARG_TYPES (TREE_TYPE (fn)),
1949 candidates = tree_cons (NULL_TREE, fn, candidates);
1953 if (templates && TREE_CHAIN (templates))
1959 It is possible for a specialization with a given function
1960 signature to be instantiated from more than one function
1961 template. In such cases, explicit specification of the
1962 template arguments must be used to uniquely identify the
1963 function template specialization being specialized.
1965 Note that here, there's no suggestion that we're supposed to
1966 determine which of the candidate templates is most
1967 specialized. However, we, also have:
1971 Partial ordering of overloaded function template
1972 declarations is used in the following contexts to select
1973 the function template to which a function template
1974 specialization refers:
1976 -- when an explicit specialization refers to a function
1979 So, we do use the partial ordering rules, at least for now.
1980 This extension can only serve to make invalid programs valid,
1981 so it's safe. And, there is strong anecdotal evidence that
1982 the committee intended the partial ordering rules to apply;
1983 the EDG front end has that behavior, and John Spicer claims
1984 that the committee simply forgot to delete the wording in
1985 [temp.expl.spec]. */
1986 tree tmpl = most_specialized_instantiation (templates);
1987 if (tmpl != error_mark_node)
1990 TREE_CHAIN (templates) = NULL_TREE;
1994 if (templates == NULL_TREE && candidates == NULL_TREE)
1996 error ("template-id %qD for %q+D does not match any template "
1997 "declaration", template_id, decl);
1998 if (header_count && header_count != template_count + 1)
1999 inform (input_location, "saw %d %<template<>%>, need %d for "
2000 "specializing a member function template",
2001 header_count, template_count + 1);
2002 return error_mark_node;
2004 else if ((templates && TREE_CHAIN (templates))
2005 || (candidates && TREE_CHAIN (candidates))
2006 || (templates && candidates))
2008 error ("ambiguous template specialization %qD for %q+D",
2010 candidates = chainon (candidates, templates);
2011 print_candidates (candidates);
2012 return error_mark_node;
2015 /* We have one, and exactly one, match. */
2018 tree fn = TREE_VALUE (candidates);
2019 *targs_out = copy_node (DECL_TI_ARGS (fn));
2020 /* DECL is a re-declaration or partial instantiation of a template
2022 if (TREE_CODE (fn) == TEMPLATE_DECL)
2024 /* It was a specialization of an ordinary member function in a
2026 return DECL_TI_TEMPLATE (fn);
2029 /* It was a specialization of a template. */
2030 targs = DECL_TI_ARGS (DECL_TEMPLATE_RESULT (TREE_VALUE (templates)));
2031 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (targs))
2033 *targs_out = copy_node (targs);
2034 SET_TMPL_ARGS_LEVEL (*targs_out,
2035 TMPL_ARGS_DEPTH (*targs_out),
2036 TREE_PURPOSE (templates));
2039 *targs_out = TREE_PURPOSE (templates);
2040 return TREE_VALUE (templates);
2043 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2044 but with the default argument values filled in from those in the
2048 copy_default_args_to_explicit_spec_1 (tree spec_types,
2051 tree new_spec_types;
2056 if (spec_types == void_list_node)
2057 return void_list_node;
2059 /* Substitute into the rest of the list. */
2061 copy_default_args_to_explicit_spec_1 (TREE_CHAIN (spec_types),
2062 TREE_CHAIN (tmpl_types));
2064 /* Add the default argument for this parameter. */
2065 return hash_tree_cons (TREE_PURPOSE (tmpl_types),
2066 TREE_VALUE (spec_types),
2070 /* DECL is an explicit specialization. Replicate default arguments
2071 from the template it specializes. (That way, code like:
2073 template <class T> void f(T = 3);
2074 template <> void f(double);
2077 works, as required.) An alternative approach would be to look up
2078 the correct default arguments at the call-site, but this approach
2079 is consistent with how implicit instantiations are handled. */
2082 copy_default_args_to_explicit_spec (tree decl)
2087 tree new_spec_types;
2091 tree object_type = NULL_TREE;
2092 tree in_charge = NULL_TREE;
2093 tree vtt = NULL_TREE;
2095 /* See if there's anything we need to do. */
2096 tmpl = DECL_TI_TEMPLATE (decl);
2097 tmpl_types = TYPE_ARG_TYPES (TREE_TYPE (DECL_TEMPLATE_RESULT (tmpl)));
2098 for (t = tmpl_types; t; t = TREE_CHAIN (t))
2099 if (TREE_PURPOSE (t))
2104 old_type = TREE_TYPE (decl);
2105 spec_types = TYPE_ARG_TYPES (old_type);
2107 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2109 /* Remove the this pointer, but remember the object's type for
2111 object_type = TREE_TYPE (TREE_VALUE (spec_types));
2112 spec_types = TREE_CHAIN (spec_types);
2113 tmpl_types = TREE_CHAIN (tmpl_types);
2115 if (DECL_HAS_IN_CHARGE_PARM_P (decl))
2117 /* DECL may contain more parameters than TMPL due to the extra
2118 in-charge parameter in constructors and destructors. */
2119 in_charge = spec_types;
2120 spec_types = TREE_CHAIN (spec_types);
2122 if (DECL_HAS_VTT_PARM_P (decl))
2125 spec_types = TREE_CHAIN (spec_types);
2129 /* Compute the merged default arguments. */
2131 copy_default_args_to_explicit_spec_1 (spec_types, tmpl_types);
2133 /* Compute the new FUNCTION_TYPE. */
2137 new_spec_types = hash_tree_cons (TREE_PURPOSE (vtt),
2142 /* Put the in-charge parameter back. */
2143 new_spec_types = hash_tree_cons (TREE_PURPOSE (in_charge),
2144 TREE_VALUE (in_charge),
2147 new_type = build_method_type_directly (object_type,
2148 TREE_TYPE (old_type),
2152 new_type = build_function_type (TREE_TYPE (old_type),
2154 new_type = cp_build_type_attribute_variant (new_type,
2155 TYPE_ATTRIBUTES (old_type));
2156 new_type = build_exception_variant (new_type,
2157 TYPE_RAISES_EXCEPTIONS (old_type));
2158 TREE_TYPE (decl) = new_type;
2161 /* Check to see if the function just declared, as indicated in
2162 DECLARATOR, and in DECL, is a specialization of a function
2163 template. We may also discover that the declaration is an explicit
2164 instantiation at this point.
2166 Returns DECL, or an equivalent declaration that should be used
2167 instead if all goes well. Issues an error message if something is
2168 amiss. Returns error_mark_node if the error is not easily
2171 FLAGS is a bitmask consisting of the following flags:
2173 2: The function has a definition.
2174 4: The function is a friend.
2176 The TEMPLATE_COUNT is the number of references to qualifying
2177 template classes that appeared in the name of the function. For
2180 template <class T> struct S { void f(); };
2183 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2184 classes are not counted in the TEMPLATE_COUNT, so that in
2186 template <class T> struct S {};
2187 template <> struct S<int> { void f(); }
2188 template <> void S<int>::f();
2190 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2191 invalid; there should be no template <>.)
2193 If the function is a specialization, it is marked as such via
2194 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2195 is set up correctly, and it is added to the list of specializations
2196 for that template. */
2199 check_explicit_specialization (tree declarator,
2204 int have_def = flags & 2;
2205 int is_friend = flags & 4;
2206 int specialization = 0;
2207 int explicit_instantiation = 0;
2208 int member_specialization = 0;
2209 tree ctype = DECL_CLASS_CONTEXT (decl);
2210 tree dname = DECL_NAME (decl);
2215 if (!processing_specialization)
2218 tsk = tsk_excessive_parms;
2221 tsk = current_tmpl_spec_kind (template_count);
2226 if (processing_specialization)
2229 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2231 else if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2234 /* This could be something like:
2236 template <class T> void f(T);
2237 class S { friend void f<>(int); } */
2241 /* This case handles bogus declarations like template <>
2242 template <class T> void f<int>(); */
2244 error ("template-id %qD in declaration of primary template",
2251 case tsk_invalid_member_spec:
2252 /* The error has already been reported in
2253 check_specialization_scope. */
2254 return error_mark_node;
2256 case tsk_invalid_expl_inst:
2257 error ("template parameter list used in explicit instantiation");
2263 error ("definition provided for explicit instantiation");
2265 explicit_instantiation = 1;
2268 case tsk_excessive_parms:
2269 case tsk_insufficient_parms:
2270 if (tsk == tsk_excessive_parms)
2271 error ("too many template parameter lists in declaration of %qD",
2273 else if (template_header_count)
2274 error("too few template parameter lists in declaration of %qD", decl);
2276 error("explicit specialization of %qD must be introduced by "
2277 "%<template <>%>", decl);
2281 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2283 member_specialization = 1;
2289 if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2291 /* This case handles bogus declarations like template <>
2292 template <class T> void f<int>(); */
2294 if (uses_template_parms (declarator))
2295 error ("function template partial specialization %qD "
2296 "is not allowed", declarator);
2298 error ("template-id %qD in declaration of primary template",
2303 if (ctype && CLASSTYPE_TEMPLATE_INSTANTIATION (ctype))
2304 /* This is a specialization of a member template, without
2305 specialization the containing class. Something like:
2307 template <class T> struct S {
2308 template <class U> void f (U);
2310 template <> template <class U> void S<int>::f(U) {}
2312 That's a specialization -- but of the entire template. */
2320 if (specialization || member_specialization)
2322 tree t = TYPE_ARG_TYPES (TREE_TYPE (decl));
2323 for (; t; t = TREE_CHAIN (t))
2324 if (TREE_PURPOSE (t))
2326 permerror (input_location,
2327 "default argument specified in explicit specialization");
2332 if (specialization || member_specialization || explicit_instantiation)
2334 tree tmpl = NULL_TREE;
2335 tree targs = NULL_TREE;
2337 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2338 if (TREE_CODE (declarator) != TEMPLATE_ID_EXPR)
2342 gcc_assert (TREE_CODE (declarator) == IDENTIFIER_NODE);
2347 /* If there is no class context, the explicit instantiation
2348 must be at namespace scope. */
2349 gcc_assert (DECL_NAMESPACE_SCOPE_P (decl));
2351 /* Find the namespace binding, using the declaration
2353 fns = lookup_qualified_name (CP_DECL_CONTEXT (decl), dname,
2355 if (fns == error_mark_node || !is_overloaded_fn (fns))
2357 error ("%qD is not a template function", dname);
2358 fns = error_mark_node;
2362 tree fn = OVL_CURRENT (fns);
2363 if (!is_associated_namespace (CP_DECL_CONTEXT (decl),
2364 CP_DECL_CONTEXT (fn)))
2365 error ("%qD is not declared in %qD",
2366 decl, current_namespace);
2370 declarator = lookup_template_function (fns, NULL_TREE);
2373 if (declarator == error_mark_node)
2374 return error_mark_node;
2376 if (ctype != NULL_TREE && TYPE_BEING_DEFINED (ctype))
2378 if (!explicit_instantiation)
2379 /* A specialization in class scope. This is invalid,
2380 but the error will already have been flagged by
2381 check_specialization_scope. */
2382 return error_mark_node;
2385 /* It's not valid to write an explicit instantiation in
2388 class C { template void f(); }
2390 This case is caught by the parser. However, on
2393 template class C { void f(); };
2395 (which is invalid) we can get here. The error will be
2402 else if (ctype != NULL_TREE
2403 && (TREE_CODE (TREE_OPERAND (declarator, 0)) ==
2406 /* Find the list of functions in ctype that have the same
2407 name as the declared function. */
2408 tree name = TREE_OPERAND (declarator, 0);
2409 tree fns = NULL_TREE;
2412 if (constructor_name_p (name, ctype))
2414 int is_constructor = DECL_CONSTRUCTOR_P (decl);
2416 if (is_constructor ? !TYPE_HAS_USER_CONSTRUCTOR (ctype)
2417 : !CLASSTYPE_DESTRUCTORS (ctype))
2419 /* From [temp.expl.spec]:
2421 If such an explicit specialization for the member
2422 of a class template names an implicitly-declared
2423 special member function (clause _special_), the
2424 program is ill-formed.
2426 Similar language is found in [temp.explicit]. */
2427 error ("specialization of implicitly-declared special member function");
2428 return error_mark_node;
2431 name = is_constructor ? ctor_identifier : dtor_identifier;
2434 if (!DECL_CONV_FN_P (decl))
2436 idx = lookup_fnfields_1 (ctype, name);
2438 fns = VEC_index (tree, CLASSTYPE_METHOD_VEC (ctype), idx);
2442 VEC(tree,gc) *methods;
2445 /* For a type-conversion operator, we cannot do a
2446 name-based lookup. We might be looking for `operator
2447 int' which will be a specialization of `operator T'.
2448 So, we find *all* the conversion operators, and then
2449 select from them. */
2452 methods = CLASSTYPE_METHOD_VEC (ctype);
2454 for (idx = CLASSTYPE_FIRST_CONVERSION_SLOT;
2455 VEC_iterate (tree, methods, idx, ovl);
2458 if (!DECL_CONV_FN_P (OVL_CURRENT (ovl)))
2459 /* There are no more conversion functions. */
2462 /* Glue all these conversion functions together
2463 with those we already have. */
2464 for (; ovl; ovl = OVL_NEXT (ovl))
2465 fns = ovl_cons (OVL_CURRENT (ovl), fns);
2469 if (fns == NULL_TREE)
2471 error ("no member function %qD declared in %qT", name, ctype);
2472 return error_mark_node;
2475 TREE_OPERAND (declarator, 0) = fns;
2478 /* Figure out what exactly is being specialized at this point.
2479 Note that for an explicit instantiation, even one for a
2480 member function, we cannot tell apriori whether the
2481 instantiation is for a member template, or just a member
2482 function of a template class. Even if a member template is
2483 being instantiated, the member template arguments may be
2484 elided if they can be deduced from the rest of the
2486 tmpl = determine_specialization (declarator, decl,
2488 member_specialization,
2492 if (!tmpl || tmpl == error_mark_node)
2493 /* We couldn't figure out what this declaration was
2495 return error_mark_node;
2498 tree gen_tmpl = most_general_template (tmpl);
2500 if (explicit_instantiation)
2502 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2503 is done by do_decl_instantiation later. */
2505 int arg_depth = TMPL_ARGS_DEPTH (targs);
2506 int parm_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
2508 if (arg_depth > parm_depth)
2510 /* If TMPL is not the most general template (for
2511 example, if TMPL is a friend template that is
2512 injected into namespace scope), then there will
2513 be too many levels of TARGS. Remove some of them
2518 new_targs = make_tree_vec (parm_depth);
2519 for (i = arg_depth - parm_depth; i < arg_depth; ++i)
2520 TREE_VEC_ELT (new_targs, i - (arg_depth - parm_depth))
2521 = TREE_VEC_ELT (targs, i);
2525 return instantiate_template (tmpl, targs, tf_error);
2528 /* If we thought that the DECL was a member function, but it
2529 turns out to be specializing a static member function,
2530 make DECL a static member function as well. */
2531 if (DECL_STATIC_FUNCTION_P (tmpl)
2532 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2533 revert_static_member_fn (decl);
2535 /* If this is a specialization of a member template of a
2536 template class, we want to return the TEMPLATE_DECL, not
2537 the specialization of it. */
2538 if (tsk == tsk_template)
2540 tree result = DECL_TEMPLATE_RESULT (tmpl);
2541 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
2542 DECL_INITIAL (result) = NULL_TREE;
2546 DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl);
2547 DECL_SOURCE_LOCATION (result)
2548 = DECL_SOURCE_LOCATION (decl);
2549 /* We want to use the argument list specified in the
2550 definition, not in the original declaration. */
2551 DECL_ARGUMENTS (result) = DECL_ARGUMENTS (decl);
2552 for (parm = DECL_ARGUMENTS (result); parm;
2553 parm = TREE_CHAIN (parm))
2554 DECL_CONTEXT (parm) = result;
2556 return register_specialization (tmpl, gen_tmpl, targs,
2560 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2561 DECL_TEMPLATE_INFO (decl) = build_template_info (tmpl, targs);
2563 /* Inherit default function arguments from the template
2564 DECL is specializing. */
2565 copy_default_args_to_explicit_spec (decl);
2567 /* This specialization has the same protection as the
2568 template it specializes. */
2569 TREE_PRIVATE (decl) = TREE_PRIVATE (gen_tmpl);
2570 TREE_PROTECTED (decl) = TREE_PROTECTED (gen_tmpl);
2572 /* 7.1.1-1 [dcl.stc]
2574 A storage-class-specifier shall not be specified in an
2575 explicit specialization...
2577 The parser rejects these, so unless action is taken here,
2578 explicit function specializations will always appear with
2581 The action recommended by the C++ CWG in response to C++
2582 defect report 605 is to make the storage class and linkage
2583 of the explicit specialization match the templated function:
2585 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2587 if (tsk == tsk_expl_spec && DECL_FUNCTION_TEMPLATE_P (gen_tmpl))
2589 tree tmpl_func = DECL_TEMPLATE_RESULT (gen_tmpl);
2590 gcc_assert (TREE_CODE (tmpl_func) == FUNCTION_DECL);
2592 /* This specialization has the same linkage and visibility as
2593 the function template it specializes. */
2594 TREE_PUBLIC (decl) = TREE_PUBLIC (tmpl_func);
2595 if (! TREE_PUBLIC (decl))
2597 DECL_INTERFACE_KNOWN (decl) = 1;
2598 DECL_NOT_REALLY_EXTERN (decl) = 1;
2600 DECL_THIS_STATIC (decl) = DECL_THIS_STATIC (tmpl_func);
2601 if (DECL_VISIBILITY_SPECIFIED (tmpl_func))
2603 DECL_VISIBILITY_SPECIFIED (decl) = 1;
2604 DECL_VISIBILITY (decl) = DECL_VISIBILITY (tmpl_func);
2608 /* If DECL is a friend declaration, declared using an
2609 unqualified name, the namespace associated with DECL may
2610 have been set incorrectly. For example, in:
2612 template <typename T> void f(T);
2614 struct S { friend void f<int>(int); }
2617 we will have set the DECL_CONTEXT for the friend
2618 declaration to N, rather than to the global namespace. */
2619 if (DECL_NAMESPACE_SCOPE_P (decl))
2620 DECL_CONTEXT (decl) = DECL_CONTEXT (tmpl);
2622 if (is_friend && !have_def)
2623 /* This is not really a declaration of a specialization.
2624 It's just the name of an instantiation. But, it's not
2625 a request for an instantiation, either. */
2626 SET_DECL_IMPLICIT_INSTANTIATION (decl);
2627 else if (DECL_CONSTRUCTOR_P (decl) || DECL_DESTRUCTOR_P (decl))
2628 /* This is indeed a specialization. In case of constructors
2629 and destructors, we need in-charge and not-in-charge
2630 versions in V3 ABI. */
2631 clone_function_decl (decl, /*update_method_vec_p=*/0);
2633 /* Register this specialization so that we can find it
2635 decl = register_specialization (decl, gen_tmpl, targs, is_friend, 0);
2642 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2643 parameters. These are represented in the same format used for
2644 DECL_TEMPLATE_PARMS. */
2647 comp_template_parms (const_tree parms1, const_tree parms2)
2652 if (parms1 == parms2)
2655 for (p1 = parms1, p2 = parms2;
2656 p1 != NULL_TREE && p2 != NULL_TREE;
2657 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2))
2659 tree t1 = TREE_VALUE (p1);
2660 tree t2 = TREE_VALUE (p2);
2663 gcc_assert (TREE_CODE (t1) == TREE_VEC);
2664 gcc_assert (TREE_CODE (t2) == TREE_VEC);
2666 if (TREE_VEC_LENGTH (t1) != TREE_VEC_LENGTH (t2))
2669 for (i = 0; i < TREE_VEC_LENGTH (t2); ++i)
2671 tree parm1 = TREE_VALUE (TREE_VEC_ELT (t1, i));
2672 tree parm2 = TREE_VALUE (TREE_VEC_ELT (t2, i));
2674 /* If either of the template parameters are invalid, assume
2675 they match for the sake of error recovery. */
2676 if (parm1 == error_mark_node || parm2 == error_mark_node)
2679 if (TREE_CODE (parm1) != TREE_CODE (parm2))
2682 if (TREE_CODE (parm1) == TEMPLATE_TYPE_PARM
2683 && (TEMPLATE_TYPE_PARAMETER_PACK (parm1)
2684 == TEMPLATE_TYPE_PARAMETER_PACK (parm2)))
2686 else if (!same_type_p (TREE_TYPE (parm1), TREE_TYPE (parm2)))
2691 if ((p1 != NULL_TREE) != (p2 != NULL_TREE))
2692 /* One set of parameters has more parameters lists than the
2699 /* Determine whether PARM is a parameter pack. */
2702 template_parameter_pack_p (const_tree parm)
2704 /* Determine if we have a non-type template parameter pack. */
2705 if (TREE_CODE (parm) == PARM_DECL)
2706 return (DECL_TEMPLATE_PARM_P (parm)
2707 && TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)));
2709 /* If this is a list of template parameters, we could get a
2710 TYPE_DECL or a TEMPLATE_DECL. */
2711 if (TREE_CODE (parm) == TYPE_DECL || TREE_CODE (parm) == TEMPLATE_DECL)
2712 parm = TREE_TYPE (parm);
2714 return ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
2715 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM)
2716 && TEMPLATE_TYPE_PARAMETER_PACK (parm));
2719 /* Determine if T is a function parameter pack. */
2722 function_parameter_pack_p (const_tree t)
2724 if (t && TREE_CODE (t) == PARM_DECL)
2725 return FUNCTION_PARAMETER_PACK_P (t);
2729 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2730 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2733 get_function_template_decl (const_tree primary_func_tmpl_inst)
2735 if (! primary_func_tmpl_inst
2736 || TREE_CODE (primary_func_tmpl_inst) != FUNCTION_DECL
2737 || ! primary_template_instantiation_p (primary_func_tmpl_inst))
2740 return DECL_TEMPLATE_RESULT (DECL_TI_TEMPLATE (primary_func_tmpl_inst));
2743 /* Return true iff the function parameter PARAM_DECL was expanded
2744 from the function parameter pack PACK. */
2747 function_parameter_expanded_from_pack_p (tree param_decl, tree pack)
2749 if (DECL_ARTIFICIAL (param_decl)
2750 || !function_parameter_pack_p (pack))
2753 /* The parameter pack and its pack arguments have the same
2755 return DECL_PARM_INDEX (pack) == DECL_PARM_INDEX (param_decl);
2758 /* Determine whether ARGS describes a variadic template args list,
2759 i.e., one that is terminated by a template argument pack. */
2762 template_args_variadic_p (tree args)
2767 if (args == NULL_TREE)
2770 args = INNERMOST_TEMPLATE_ARGS (args);
2771 nargs = TREE_VEC_LENGTH (args);
2776 last_parm = TREE_VEC_ELT (args, nargs - 1);
2778 return ARGUMENT_PACK_P (last_parm);
2781 /* Generate a new name for the parameter pack name NAME (an
2782 IDENTIFIER_NODE) that incorporates its */
2785 make_ith_pack_parameter_name (tree name, int i)
2787 /* Munge the name to include the parameter index. */
2788 #define NUMBUF_LEN 128
2789 char numbuf[NUMBUF_LEN];
2793 snprintf (numbuf, NUMBUF_LEN, "%i", i);
2794 newname_len = IDENTIFIER_LENGTH (name)
2795 + strlen (numbuf) + 2;
2796 newname = (char*)alloca (newname_len);
2797 snprintf (newname, newname_len,
2798 "%s#%i", IDENTIFIER_POINTER (name), i);
2799 return get_identifier (newname);
2802 /* Return true if T is a primary function
2803 or class template instantiation. */
2806 primary_template_instantiation_p (const_tree t)
2811 if (TREE_CODE (t) == FUNCTION_DECL)
2812 return DECL_LANG_SPECIFIC (t)
2813 && DECL_TEMPLATE_INSTANTIATION (t)
2814 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (t));
2815 else if (CLASS_TYPE_P (t))
2816 return CLASSTYPE_TEMPLATE_INSTANTIATION (t)
2817 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (t));
2821 /* Return true if PARM is a template template parameter. */
2824 template_template_parameter_p (const_tree parm)
2826 return DECL_TEMPLATE_TEMPLATE_PARM_P (parm);
2829 /* Return the template parameters of T if T is a
2830 primary template instantiation, NULL otherwise. */
2833 get_primary_template_innermost_parameters (const_tree t)
2835 tree parms = NULL, template_info = NULL;
2837 if ((template_info = get_template_info (t))
2838 && primary_template_instantiation_p (t))
2839 parms = INNERMOST_TEMPLATE_PARMS
2840 (DECL_TEMPLATE_PARMS (TI_TEMPLATE (template_info)));
2845 /* Return the template parameters of the LEVELth level from the full list
2846 of template parameters PARMS. */
2849 get_template_parms_at_level (tree parms, int level)
2853 || TREE_CODE (parms) != TREE_LIST
2854 || level > TMPL_PARMS_DEPTH (parms))
2857 for (p = parms; p; p = TREE_CHAIN (p))
2858 if (TMPL_PARMS_DEPTH (p) == level)
2864 /* Returns the template arguments of T if T is a template instantiation,
2868 get_template_innermost_arguments (const_tree t)
2870 tree args = NULL, template_info = NULL;
2872 if ((template_info = get_template_info (t))
2873 && TI_ARGS (template_info))
2874 args = INNERMOST_TEMPLATE_ARGS (TI_ARGS (template_info));
2879 /* Return the argument pack elements of T if T is a template argument pack,
2883 get_template_argument_pack_elems (const_tree t)
2885 if (TREE_CODE (t) != TYPE_ARGUMENT_PACK
2886 && TREE_CODE (t) != NONTYPE_ARGUMENT_PACK)
2889 return ARGUMENT_PACK_ARGS (t);
2892 /* Structure used to track the progress of find_parameter_packs_r. */
2893 struct find_parameter_pack_data
2895 /* TREE_LIST that will contain all of the parameter packs found by
2897 tree* parameter_packs;
2899 /* Set of AST nodes that have been visited by the traversal. */
2900 struct pointer_set_t *visited;
2903 /* Identifies all of the argument packs that occur in a template
2904 argument and appends them to the TREE_LIST inside DATA, which is a
2905 find_parameter_pack_data structure. This is a subroutine of
2906 make_pack_expansion and uses_parameter_packs. */
2908 find_parameter_packs_r (tree *tp, int *walk_subtrees, void* data)
2911 struct find_parameter_pack_data* ppd =
2912 (struct find_parameter_pack_data*)data;
2913 bool parameter_pack_p = false;
2915 /* Identify whether this is a parameter pack or not. */
2916 switch (TREE_CODE (t))
2918 case TEMPLATE_PARM_INDEX:
2919 if (TEMPLATE_PARM_PARAMETER_PACK (t))
2920 parameter_pack_p = true;
2923 case TEMPLATE_TYPE_PARM:
2924 case TEMPLATE_TEMPLATE_PARM:
2925 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
2926 parameter_pack_p = true;
2930 if (FUNCTION_PARAMETER_PACK_P (t))
2932 /* We don't want to walk into the type of a PARM_DECL,
2933 because we don't want to see the type parameter pack. */
2935 parameter_pack_p = true;
2940 /* Not a parameter pack. */
2944 if (parameter_pack_p)
2946 /* Add this parameter pack to the list. */
2947 *ppd->parameter_packs = tree_cons (NULL_TREE, t, *ppd->parameter_packs);
2951 cp_walk_tree (&TYPE_CONTEXT (t),
2952 &find_parameter_packs_r, ppd, ppd->visited);
2954 /* This switch statement will return immediately if we don't find a
2956 switch (TREE_CODE (t))
2958 case TEMPLATE_PARM_INDEX:
2961 case BOUND_TEMPLATE_TEMPLATE_PARM:
2962 /* Check the template itself. */
2963 cp_walk_tree (&TREE_TYPE (TYPE_TI_TEMPLATE (t)),
2964 &find_parameter_packs_r, ppd, ppd->visited);
2965 /* Check the template arguments. */
2966 cp_walk_tree (&TYPE_TI_ARGS (t), &find_parameter_packs_r, ppd,
2971 case TEMPLATE_TYPE_PARM:
2972 case TEMPLATE_TEMPLATE_PARM:
2979 if (TYPE_PTRMEMFUNC_P (t))
2985 if (TYPE_TEMPLATE_INFO (t))
2986 cp_walk_tree (&TI_ARGS (TYPE_TEMPLATE_INFO (t)),
2987 &find_parameter_packs_r, ppd, ppd->visited);
2993 cp_walk_tree (&TREE_TYPE (t),
2994 &find_parameter_packs_r, ppd, ppd->visited);
2998 cp_walk_tree (&TYPENAME_TYPE_FULLNAME (t), &find_parameter_packs_r,
3003 case TYPE_PACK_EXPANSION:
3004 case EXPR_PACK_EXPANSION:
3009 cp_walk_tree (&TYPE_MAX_VALUE (t), &find_parameter_packs_r,
3014 case IDENTIFIER_NODE:
3015 cp_walk_tree (&TREE_TYPE (t), &find_parameter_packs_r, ppd,
3027 /* Determines if the expression or type T uses any parameter packs. */
3029 uses_parameter_packs (tree t)
3031 tree parameter_packs = NULL_TREE;
3032 struct find_parameter_pack_data ppd;
3033 ppd.parameter_packs = ¶meter_packs;
3034 ppd.visited = pointer_set_create ();
3035 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
3036 pointer_set_destroy (ppd.visited);
3037 return parameter_packs != NULL_TREE;
3040 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3041 representation a base-class initializer into a parameter pack
3042 expansion. If all goes well, the resulting node will be an
3043 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3046 make_pack_expansion (tree arg)
3049 tree parameter_packs = NULL_TREE;
3050 bool for_types = false;
3051 struct find_parameter_pack_data ppd;
3053 if (!arg || arg == error_mark_node)
3056 if (TREE_CODE (arg) == TREE_LIST)
3058 /* The only time we will see a TREE_LIST here is for a base
3059 class initializer. In this case, the TREE_PURPOSE will be a
3060 _TYPE node (representing the base class expansion we're
3061 initializing) and the TREE_VALUE will be a TREE_LIST
3062 containing the initialization arguments.
3064 The resulting expansion looks somewhat different from most
3065 expansions. Rather than returning just one _EXPANSION, we
3066 return a TREE_LIST whose TREE_PURPOSE is a
3067 TYPE_PACK_EXPANSION containing the bases that will be
3068 initialized. The TREE_VALUE will be identical to the
3069 original TREE_VALUE, which is a list of arguments that will
3070 be passed to each base. We do not introduce any new pack
3071 expansion nodes into the TREE_VALUE (although it is possible
3072 that some already exist), because the TREE_PURPOSE and
3073 TREE_VALUE all need to be expanded together with the same
3074 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3075 resulting TREE_PURPOSE will mention the parameter packs in
3076 both the bases and the arguments to the bases. */
3079 tree parameter_packs = NULL_TREE;
3081 /* Determine which parameter packs will be used by the base
3083 ppd.visited = pointer_set_create ();
3084 ppd.parameter_packs = ¶meter_packs;
3085 cp_walk_tree (&TREE_PURPOSE (arg), &find_parameter_packs_r,
3088 if (parameter_packs == NULL_TREE)
3090 error ("base initializer expansion %<%T%> contains no parameter packs", arg);
3091 pointer_set_destroy (ppd.visited);
3092 return error_mark_node;
3095 if (TREE_VALUE (arg) != void_type_node)
3097 /* Collect the sets of parameter packs used in each of the
3098 initialization arguments. */
3099 for (value = TREE_VALUE (arg); value; value = TREE_CHAIN (value))
3101 /* Determine which parameter packs will be expanded in this
3103 cp_walk_tree (&TREE_VALUE (value), &find_parameter_packs_r,
3108 pointer_set_destroy (ppd.visited);
3110 /* Create the pack expansion type for the base type. */
3111 purpose = cxx_make_type (TYPE_PACK_EXPANSION);
3112 SET_PACK_EXPANSION_PATTERN (purpose, TREE_PURPOSE (arg));
3113 PACK_EXPANSION_PARAMETER_PACKS (purpose) = parameter_packs;
3115 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3116 they will rarely be compared to anything. */
3117 SET_TYPE_STRUCTURAL_EQUALITY (purpose);
3119 return tree_cons (purpose, TREE_VALUE (arg), NULL_TREE);
3122 if (TYPE_P (arg) || TREE_CODE (arg) == TEMPLATE_DECL)
3125 /* Build the PACK_EXPANSION_* node. */
3127 ? cxx_make_type (TYPE_PACK_EXPANSION)
3128 : make_node (EXPR_PACK_EXPANSION);
3129 SET_PACK_EXPANSION_PATTERN (result, arg);
3130 if (TREE_CODE (result) == EXPR_PACK_EXPANSION)
3132 /* Propagate type and const-expression information. */
3133 TREE_TYPE (result) = TREE_TYPE (arg);
3134 TREE_CONSTANT (result) = TREE_CONSTANT (arg);
3137 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3138 they will rarely be compared to anything. */
3139 SET_TYPE_STRUCTURAL_EQUALITY (result);
3141 /* Determine which parameter packs will be expanded. */
3142 ppd.parameter_packs = ¶meter_packs;
3143 ppd.visited = pointer_set_create ();
3144 cp_walk_tree (&arg, &find_parameter_packs_r, &ppd, ppd.visited);
3145 pointer_set_destroy (ppd.visited);
3147 /* Make sure we found some parameter packs. */
3148 if (parameter_packs == NULL_TREE)
3151 error ("expansion pattern %<%T%> contains no argument packs", arg);
3153 error ("expansion pattern %<%E%> contains no argument packs", arg);
3154 return error_mark_node;
3156 PACK_EXPANSION_PARAMETER_PACKS (result) = parameter_packs;
3161 /* Checks T for any "bare" parameter packs, which have not yet been
3162 expanded, and issues an error if any are found. This operation can
3163 only be done on full expressions or types (e.g., an expression
3164 statement, "if" condition, etc.), because we could have expressions like:
3166 foo(f(g(h(args)))...)
3168 where "args" is a parameter pack. check_for_bare_parameter_packs
3169 should not be called for the subexpressions args, h(args),
3170 g(h(args)), or f(g(h(args))), because we would produce erroneous
3173 Returns TRUE and emits an error if there were bare parameter packs,
3174 returns FALSE otherwise. */
3176 check_for_bare_parameter_packs (tree t)
3178 tree parameter_packs = NULL_TREE;
3179 struct find_parameter_pack_data ppd;
3181 if (!processing_template_decl || !t || t == error_mark_node)
3184 if (TREE_CODE (t) == TYPE_DECL)
3187 ppd.parameter_packs = ¶meter_packs;
3188 ppd.visited = pointer_set_create ();
3189 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
3190 pointer_set_destroy (ppd.visited);
3192 if (parameter_packs)
3194 error ("parameter packs not expanded with %<...%>:");
3195 while (parameter_packs)
3197 tree pack = TREE_VALUE (parameter_packs);
3198 tree name = NULL_TREE;
3200 if (TREE_CODE (pack) == TEMPLATE_TYPE_PARM
3201 || TREE_CODE (pack) == TEMPLATE_TEMPLATE_PARM)
3202 name = TYPE_NAME (pack);
3203 else if (TREE_CODE (pack) == TEMPLATE_PARM_INDEX)
3204 name = DECL_NAME (TEMPLATE_PARM_DECL (pack));
3206 name = DECL_NAME (pack);
3209 inform (input_location, " %qD", name);
3211 inform (input_location, " <anonymous>");
3213 parameter_packs = TREE_CHAIN (parameter_packs);
3222 /* Expand any parameter packs that occur in the template arguments in
3225 expand_template_argument_pack (tree args)
3227 tree result_args = NULL_TREE;
3228 int in_arg, out_arg = 0, nargs = args ? TREE_VEC_LENGTH (args) : 0;
3229 int num_result_args = -1;
3230 int non_default_args_count = -1;
3232 /* First, determine if we need to expand anything, and the number of
3233 slots we'll need. */
3234 for (in_arg = 0; in_arg < nargs; ++in_arg)
3236 tree arg = TREE_VEC_ELT (args, in_arg);
3237 if (arg == NULL_TREE)
3239 if (ARGUMENT_PACK_P (arg))
3241 int num_packed = TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg));
3242 if (num_result_args < 0)
3243 num_result_args = in_arg + num_packed;
3245 num_result_args += num_packed;
3249 if (num_result_args >= 0)
3254 /* If no expansion is necessary, we're done. */
3255 if (num_result_args < 0)
3258 /* Expand arguments. */
3259 result_args = make_tree_vec (num_result_args);
3260 if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (args))
3261 non_default_args_count =
3262 GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (args);
3263 for (in_arg = 0; in_arg < nargs; ++in_arg)
3265 tree arg = TREE_VEC_ELT (args, in_arg);
3266 if (ARGUMENT_PACK_P (arg))
3268 tree packed = ARGUMENT_PACK_ARGS (arg);
3269 int i, num_packed = TREE_VEC_LENGTH (packed);
3270 for (i = 0; i < num_packed; ++i, ++out_arg)
3271 TREE_VEC_ELT (result_args, out_arg) = TREE_VEC_ELT(packed, i);
3272 if (non_default_args_count > 0)
3273 non_default_args_count += num_packed;
3277 TREE_VEC_ELT (result_args, out_arg) = arg;
3281 if (non_default_args_count >= 0)
3282 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (result_args, non_default_args_count);
3286 /* Checks if DECL shadows a template parameter.
3288 [temp.local]: A template-parameter shall not be redeclared within its
3289 scope (including nested scopes).
3291 Emits an error and returns TRUE if the DECL shadows a parameter,
3292 returns FALSE otherwise. */
3295 check_template_shadow (tree decl)
3299 /* If we're not in a template, we can't possibly shadow a template
3301 if (!current_template_parms)
3304 /* Figure out what we're shadowing. */
3305 if (TREE_CODE (decl) == OVERLOAD)
3306 decl = OVL_CURRENT (decl);
3307 olddecl = innermost_non_namespace_value (DECL_NAME (decl));
3309 /* If there's no previous binding for this name, we're not shadowing
3310 anything, let alone a template parameter. */
3314 /* If we're not shadowing a template parameter, we're done. Note
3315 that OLDDECL might be an OVERLOAD (or perhaps even an
3316 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3318 if (!DECL_P (olddecl) || !DECL_TEMPLATE_PARM_P (olddecl))
3321 /* We check for decl != olddecl to avoid bogus errors for using a
3322 name inside a class. We check TPFI to avoid duplicate errors for
3323 inline member templates. */
3325 || TEMPLATE_PARMS_FOR_INLINE (current_template_parms))
3328 error ("declaration of %q+#D", decl);
3329 error (" shadows template parm %q+#D", olddecl);
3333 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3334 ORIG_LEVEL, DECL, and TYPE. */
3337 build_template_parm_index (int index,
3343 tree t = make_node (TEMPLATE_PARM_INDEX);
3344 TEMPLATE_PARM_IDX (t) = index;
3345 TEMPLATE_PARM_LEVEL (t) = level;
3346 TEMPLATE_PARM_ORIG_LEVEL (t) = orig_level;
3347 TEMPLATE_PARM_DECL (t) = decl;
3348 TREE_TYPE (t) = type;
3349 TREE_CONSTANT (t) = TREE_CONSTANT (decl);
3350 TREE_READONLY (t) = TREE_READONLY (decl);
3355 /* Find the canonical type parameter for the given template type
3356 parameter. Returns the canonical type parameter, which may be TYPE
3357 if no such parameter existed. */
3359 canonical_type_parameter (tree type)
3362 int idx = TEMPLATE_TYPE_IDX (type);
3363 if (!canonical_template_parms)
3364 canonical_template_parms = VEC_alloc (tree, gc, idx+1);
3366 while (VEC_length (tree, canonical_template_parms) <= (unsigned)idx)
3367 VEC_safe_push (tree, gc, canonical_template_parms, NULL_TREE);
3369 list = VEC_index (tree, canonical_template_parms, idx);
3370 while (list && !comptypes (type, TREE_VALUE (list), COMPARE_STRUCTURAL))
3371 list = TREE_CHAIN (list);
3374 return TREE_VALUE (list);
3377 VEC_replace(tree, canonical_template_parms, idx,
3378 tree_cons (NULL_TREE, type,
3379 VEC_index (tree, canonical_template_parms, idx)));
3384 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3385 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3386 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3387 new one is created. */
3390 reduce_template_parm_level (tree index, tree type, int levels, tree args,
3391 tsubst_flags_t complain)
3393 if (TEMPLATE_PARM_DESCENDANTS (index) == NULL_TREE
3394 || (TEMPLATE_PARM_LEVEL (TEMPLATE_PARM_DESCENDANTS (index))
3395 != TEMPLATE_PARM_LEVEL (index) - levels)
3396 || !same_type_p (type, TREE_TYPE (TEMPLATE_PARM_DESCENDANTS (index))))
3398 tree orig_decl = TEMPLATE_PARM_DECL (index);
3401 decl = build_decl (DECL_SOURCE_LOCATION (orig_decl),
3402 TREE_CODE (orig_decl), DECL_NAME (orig_decl), type);
3403 TREE_CONSTANT (decl) = TREE_CONSTANT (orig_decl);
3404 TREE_READONLY (decl) = TREE_READONLY (orig_decl);
3405 DECL_ARTIFICIAL (decl) = 1;
3406 SET_DECL_TEMPLATE_PARM_P (decl);
3408 t = build_template_parm_index (TEMPLATE_PARM_IDX (index),
3409 TEMPLATE_PARM_LEVEL (index) - levels,
3410 TEMPLATE_PARM_ORIG_LEVEL (index),
3412 TEMPLATE_PARM_DESCENDANTS (index) = t;
3413 TEMPLATE_PARM_PARAMETER_PACK (t)
3414 = TEMPLATE_PARM_PARAMETER_PACK (index);
3416 /* Template template parameters need this. */
3417 if (TREE_CODE (decl) == TEMPLATE_DECL)
3418 DECL_TEMPLATE_PARMS (decl) = tsubst_template_parms
3419 (DECL_TEMPLATE_PARMS (TEMPLATE_PARM_DECL (index)),
3423 return TEMPLATE_PARM_DESCENDANTS (index);
3426 /* Process information from new template parameter PARM and append it to the
3427 LIST being built. This new parameter is a non-type parameter iff
3428 IS_NON_TYPE is true. This new parameter is a parameter
3429 pack iff IS_PARAMETER_PACK is true. The location of PARM is in
3433 process_template_parm (tree list, location_t parm_loc, tree parm, bool is_non_type,
3434 bool is_parameter_pack)
3441 gcc_assert (TREE_CODE (parm) == TREE_LIST);
3442 defval = TREE_PURPOSE (parm);
3446 tree p = tree_last (list);
3448 if (p && TREE_VALUE (p) != error_mark_node)
3451 if (TREE_CODE (p) == TYPE_DECL || TREE_CODE (p) == TEMPLATE_DECL)
3452 idx = TEMPLATE_TYPE_IDX (TREE_TYPE (p));
3454 idx = TEMPLATE_PARM_IDX (DECL_INITIAL (p));
3464 parm = TREE_VALUE (parm);
3466 SET_DECL_TEMPLATE_PARM_P (parm);
3468 if (TREE_TYPE (parm) == error_mark_node)
3470 err_parm_list = build_tree_list (defval, parm);
3471 TREE_VALUE (err_parm_list) = error_mark_node;
3472 return chainon (list, err_parm_list);
3478 The top-level cv-qualifiers on the template-parameter are
3479 ignored when determining its type. */
3480 TREE_TYPE (parm) = TYPE_MAIN_VARIANT (TREE_TYPE (parm));
3481 if (invalid_nontype_parm_type_p (TREE_TYPE (parm), 1))
3483 err_parm_list = build_tree_list (defval, parm);
3484 TREE_VALUE (err_parm_list) = error_mark_node;
3485 return chainon (list, err_parm_list);
3488 if (uses_parameter_packs (TREE_TYPE (parm)) && !is_parameter_pack)
3490 /* This template parameter is not a parameter pack, but it
3491 should be. Complain about "bare" parameter packs. */
3492 check_for_bare_parameter_packs (TREE_TYPE (parm));
3494 /* Recover by calling this a parameter pack. */
3495 is_parameter_pack = true;
3499 /* A template parameter is not modifiable. */
3500 TREE_CONSTANT (parm) = 1;
3501 TREE_READONLY (parm) = 1;
3502 decl = build_decl (parm_loc,
3503 CONST_DECL, DECL_NAME (parm), TREE_TYPE (parm));
3504 TREE_CONSTANT (decl) = 1;
3505 TREE_READONLY (decl) = 1;
3506 DECL_INITIAL (parm) = DECL_INITIAL (decl)
3507 = build_template_parm_index (idx, processing_template_decl,
3508 processing_template_decl,
3509 decl, TREE_TYPE (parm));
3511 TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))
3512 = is_parameter_pack;
3517 parm = TREE_VALUE (TREE_VALUE (parm));
3519 if (parm && TREE_CODE (parm) == TEMPLATE_DECL)
3521 t = cxx_make_type (TEMPLATE_TEMPLATE_PARM);
3522 /* This is for distinguishing between real templates and template
3523 template parameters */
3524 TREE_TYPE (parm) = t;
3525 TREE_TYPE (DECL_TEMPLATE_RESULT (parm)) = t;
3530 t = cxx_make_type (TEMPLATE_TYPE_PARM);
3531 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3532 decl = build_decl (parm_loc,
3533 TYPE_DECL, parm, t);
3536 TYPE_NAME (t) = decl;
3537 TYPE_STUB_DECL (t) = decl;
3539 TEMPLATE_TYPE_PARM_INDEX (t)
3540 = build_template_parm_index (idx, processing_template_decl,
3541 processing_template_decl,
3542 decl, TREE_TYPE (parm));
3543 TEMPLATE_TYPE_PARAMETER_PACK (t) = is_parameter_pack;
3544 TYPE_CANONICAL (t) = canonical_type_parameter (t);
3546 DECL_ARTIFICIAL (decl) = 1;
3547 SET_DECL_TEMPLATE_PARM_P (decl);
3549 parm = build_tree_list (defval, parm);
3550 return chainon (list, parm);
3553 /* The end of a template parameter list has been reached. Process the
3554 tree list into a parameter vector, converting each parameter into a more
3555 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3559 end_template_parm_list (tree parms)
3563 tree saved_parmlist = make_tree_vec (list_length (parms));
3565 current_template_parms
3566 = tree_cons (size_int (processing_template_decl),
3567 saved_parmlist, current_template_parms);
3569 for (parm = parms, nparms = 0; parm; parm = next, nparms++)
3571 next = TREE_CHAIN (parm);
3572 TREE_VEC_ELT (saved_parmlist, nparms) = parm;
3573 TREE_CHAIN (parm) = NULL_TREE;
3574 if (TREE_CODE (TREE_VALUE (parm)) == TYPE_DECL)
3575 TEMPLATE_TYPE_PARM_SIBLING_PARMS (TREE_TYPE (TREE_VALUE (parm))) =
3576 current_template_parms;
3579 --processing_template_parmlist;
3581 return saved_parmlist;
3584 /* end_template_decl is called after a template declaration is seen. */
3587 end_template_decl (void)
3589 reset_specialization ();
3591 if (! processing_template_decl)
3594 /* This matches the pushlevel in begin_template_parm_list. */
3597 --processing_template_decl;
3598 current_template_parms = TREE_CHAIN (current_template_parms);
3601 /* Within the declaration of a template, return all levels of template
3602 parameters that apply. The template parameters are represented as
3603 a TREE_VEC, in the form documented in cp-tree.h for template
3607 current_template_args (void)
3610 tree args = NULL_TREE;
3611 int length = TMPL_PARMS_DEPTH (current_template_parms);
3614 /* If there is only one level of template parameters, we do not
3615 create a TREE_VEC of TREE_VECs. Instead, we return a single
3616 TREE_VEC containing the arguments. */
3618 args = make_tree_vec (length);
3620 for (header = current_template_parms; header; header = TREE_CHAIN (header))
3622 tree a = copy_node (TREE_VALUE (header));
3625 TREE_TYPE (a) = NULL_TREE;
3626 for (i = TREE_VEC_LENGTH (a) - 1; i >= 0; --i)
3628 tree t = TREE_VEC_ELT (a, i);
3630 /* T will be a list if we are called from within a
3631 begin/end_template_parm_list pair, but a vector directly
3632 if within a begin/end_member_template_processing pair. */
3633 if (TREE_CODE (t) == TREE_LIST)
3637 if (!error_operand_p (t))
3639 if (TREE_CODE (t) == TYPE_DECL
3640 || TREE_CODE (t) == TEMPLATE_DECL)
3644 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
3646 /* Turn this argument into a TYPE_ARGUMENT_PACK
3647 with a single element, which expands T. */
3648 tree vec = make_tree_vec (1);
3649 #ifdef ENABLE_CHECKING
3650 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3651 (vec, TREE_VEC_LENGTH (vec));
3653 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
3655 t = cxx_make_type (TYPE_ARGUMENT_PACK);
3656 SET_ARGUMENT_PACK_ARGS (t, vec);
3661 t = DECL_INITIAL (t);
3663 if (TEMPLATE_PARM_PARAMETER_PACK (t))
3665 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3666 with a single element, which expands T. */
3667 tree vec = make_tree_vec (1);
3668 tree type = TREE_TYPE (TEMPLATE_PARM_DECL (t));
3669 #ifdef ENABLE_CHECKING
3670 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3671 (vec, TREE_VEC_LENGTH (vec));
3673 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
3675 t = make_node (NONTYPE_ARGUMENT_PACK);
3676 SET_ARGUMENT_PACK_ARGS (t, vec);
3677 TREE_TYPE (t) = type;
3680 TREE_VEC_ELT (a, i) = t;
3685 #ifdef ENABLE_CHECKING
3686 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (a, TREE_VEC_LENGTH (a));
3690 TREE_VEC_ELT (args, --l) = a;
3698 /* Update the declared TYPE by doing any lookups which were thought to be
3699 dependent, but are not now that we know the SCOPE of the declarator. */
3702 maybe_update_decl_type (tree orig_type, tree scope)
3704 tree type = orig_type;
3706 if (type == NULL_TREE)
3709 if (TREE_CODE (orig_type) == TYPE_DECL)
3710 type = TREE_TYPE (type);
3712 if (scope && TYPE_P (scope) && dependent_type_p (scope)
3713 && dependent_type_p (type)
3714 /* Don't bother building up the args in this case. */
3715 && TREE_CODE (type) != TEMPLATE_TYPE_PARM)
3717 /* tsubst in the args corresponding to the template parameters,
3718 including auto if present. Most things will be unchanged, but
3719 make_typename_type and tsubst_qualified_id will resolve
3720 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
3721 tree args = current_template_args ();
3722 tree auto_node = type_uses_auto (type);
3726 tree auto_vec = make_tree_vec (1);
3727 TREE_VEC_ELT (auto_vec, 0) = auto_node;
3728 args = add_to_template_args (args, auto_vec);
3730 pushed = push_scope (scope);
3731 type = tsubst (type, args, tf_warning_or_error, NULL_TREE);
3736 if (type == error_mark_node)
3739 if (TREE_CODE (orig_type) == TYPE_DECL)
3741 if (same_type_p (type, TREE_TYPE (orig_type)))
3744 type = TYPE_NAME (type);
3749 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
3750 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
3751 a member template. Used by push_template_decl below. */
3754 build_template_decl (tree decl, tree parms, bool member_template_p)
3756 tree tmpl = build_lang_decl (TEMPLATE_DECL, DECL_NAME (decl), NULL_TREE);
3757 DECL_TEMPLATE_PARMS (tmpl) = parms;
3758 DECL_CONTEXT (tmpl) = DECL_CONTEXT (decl);
3759 DECL_MEMBER_TEMPLATE_P (tmpl) = member_template_p;
3764 struct template_parm_data
3766 /* The level of the template parameters we are currently
3770 /* The index of the specialization argument we are currently
3774 /* An array whose size is the number of template parameters. The
3775 elements are nonzero if the parameter has been used in any one
3776 of the arguments processed so far. */
3779 /* An array whose size is the number of template arguments. The
3780 elements are nonzero if the argument makes use of template
3781 parameters of this level. */
3782 int* arg_uses_template_parms;
3785 /* Subroutine of push_template_decl used to see if each template
3786 parameter in a partial specialization is used in the explicit
3787 argument list. If T is of the LEVEL given in DATA (which is
3788 treated as a template_parm_data*), then DATA->PARMS is marked
3792 mark_template_parm (tree t, void* data)
3796 struct template_parm_data* tpd = (struct template_parm_data*) data;
3798 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
3800 level = TEMPLATE_PARM_LEVEL (t);
3801 idx = TEMPLATE_PARM_IDX (t);
3805 level = TEMPLATE_TYPE_LEVEL (t);
3806 idx = TEMPLATE_TYPE_IDX (t);
3809 if (level == tpd->level)
3811 tpd->parms[idx] = 1;
3812 tpd->arg_uses_template_parms[tpd->current_arg] = 1;
3815 /* Return zero so that for_each_template_parm will continue the
3816 traversal of the tree; we want to mark *every* template parm. */
3820 /* Process the partial specialization DECL. */
3823 process_partial_specialization (tree decl)
3825 tree type = TREE_TYPE (decl);
3826 tree maintmpl = CLASSTYPE_TI_TEMPLATE (type);
3827 tree specargs = CLASSTYPE_TI_ARGS (type);
3828 tree inner_args = INNERMOST_TEMPLATE_ARGS (specargs);
3829 tree main_inner_parms = DECL_INNERMOST_TEMPLATE_PARMS (maintmpl);
3831 int nargs = TREE_VEC_LENGTH (inner_args);
3834 int did_error_intro = 0;
3835 struct template_parm_data tpd;
3836 struct template_parm_data tpd2;
3838 gcc_assert (current_template_parms);
3840 inner_parms = INNERMOST_TEMPLATE_PARMS (current_template_parms);
3841 ntparms = TREE_VEC_LENGTH (inner_parms);
3843 /* We check that each of the template parameters given in the
3844 partial specialization is used in the argument list to the
3845 specialization. For example:
3847 template <class T> struct S;
3848 template <class T> struct S<T*>;
3850 The second declaration is OK because `T*' uses the template
3851 parameter T, whereas
3853 template <class T> struct S<int>;
3855 is no good. Even trickier is:
3866 The S2<T> declaration is actually invalid; it is a
3867 full-specialization. Of course,
3870 struct S2<T (*)(U)>;
3872 or some such would have been OK. */
3873 tpd.level = TMPL_PARMS_DEPTH (current_template_parms);
3874 tpd.parms = (int *) alloca (sizeof (int) * ntparms);
3875 memset (tpd.parms, 0, sizeof (int) * ntparms);
3877 tpd.arg_uses_template_parms = (int *) alloca (sizeof (int) * nargs);
3878 memset (tpd.arg_uses_template_parms, 0, sizeof (int) * nargs);
3879 for (i = 0; i < nargs; ++i)
3881 tpd.current_arg = i;
3882 for_each_template_parm (TREE_VEC_ELT (inner_args, i),
3883 &mark_template_parm,
3886 /*include_nondeduced_p=*/false);
3888 for (i = 0; i < ntparms; ++i)
3889 if (tpd.parms[i] == 0)
3891 /* One of the template parms was not used in the
3893 if (!did_error_intro)
3895 error ("template parameters not used in partial specialization:");
3896 did_error_intro = 1;
3899 error (" %qD", TREE_VALUE (TREE_VEC_ELT (inner_parms, i)));
3902 /* [temp.class.spec]
3904 The argument list of the specialization shall not be identical to
3905 the implicit argument list of the primary template. */
3906 if (comp_template_args
3908 INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE
3910 error ("partial specialization %qT does not specialize any template arguments", type);
3912 /* [temp.class.spec]
3914 A partially specialized non-type argument expression shall not
3915 involve template parameters of the partial specialization except
3916 when the argument expression is a simple identifier.
3918 The type of a template parameter corresponding to a specialized
3919 non-type argument shall not be dependent on a parameter of the
3922 Also, we verify that pack expansions only occur at the
3923 end of the argument list. */
3924 gcc_assert (nargs == DECL_NTPARMS (maintmpl));
3926 for (i = 0; i < nargs; ++i)
3928 tree parm = TREE_VALUE (TREE_VEC_ELT (main_inner_parms, i));
3929 tree arg = TREE_VEC_ELT (inner_args, i);
3930 tree packed_args = NULL_TREE;
3933 if (ARGUMENT_PACK_P (arg))
3935 /* Extract the arguments from the argument pack. We'll be
3936 iterating over these in the following loop. */
3937 packed_args = ARGUMENT_PACK_ARGS (arg);
3938 len = TREE_VEC_LENGTH (packed_args);
3941 for (j = 0; j < len; j++)
3944 /* Get the Jth argument in the parameter pack. */
3945 arg = TREE_VEC_ELT (packed_args, j);
3947 if (PACK_EXPANSION_P (arg))
3949 /* Pack expansions must come at the end of the
3951 if ((packed_args && j < len - 1)
3952 || (!packed_args && i < nargs - 1))
3954 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
3955 error ("parameter pack argument %qE must be at the "
3956 "end of the template argument list", arg);
3958 error ("parameter pack argument %qT must be at the "
3959 "end of the template argument list", arg);
3963 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
3964 /* We only care about the pattern. */
3965 arg = PACK_EXPANSION_PATTERN (arg);
3967 if (/* These first two lines are the `non-type' bit. */
3969 && TREE_CODE (arg) != TEMPLATE_DECL
3970 /* This next line is the `argument expression is not just a
3971 simple identifier' condition and also the `specialized
3972 non-type argument' bit. */
3973 && TREE_CODE (arg) != TEMPLATE_PARM_INDEX)
3975 if ((!packed_args && tpd.arg_uses_template_parms[i])
3976 || (packed_args && uses_template_parms (arg)))
3977 error ("template argument %qE involves template parameter(s)",
3981 /* Look at the corresponding template parameter,
3982 marking which template parameters its type depends
3984 tree type = TREE_TYPE (parm);
3988 /* We haven't yet initialized TPD2. Do so now. */
3989 tpd2.arg_uses_template_parms
3990 = (int *) alloca (sizeof (int) * nargs);
3991 /* The number of parameters here is the number in the
3992 main template, which, as checked in the assertion
3994 tpd2.parms = (int *) alloca (sizeof (int) * nargs);
3996 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (maintmpl));
3999 /* Mark the template parameters. But this time, we're
4000 looking for the template parameters of the main
4001 template, not in the specialization. */
4002 tpd2.current_arg = i;
4003 tpd2.arg_uses_template_parms[i] = 0;
4004 memset (tpd2.parms, 0, sizeof (int) * nargs);
4005 for_each_template_parm (type,
4006 &mark_template_parm,
4009 /*include_nondeduced_p=*/false);
4011 if (tpd2.arg_uses_template_parms [i])
4013 /* The type depended on some template parameters.
4014 If they are fully specialized in the
4015 specialization, that's OK. */
4018 for (j = 0; j < nargs; ++j)
4019 if (tpd2.parms[j] != 0
4020 && tpd.arg_uses_template_parms [j])
4023 error_n (input_location, count,
4024 "type %qT of template argument %qE depends "
4025 "on a template parameter",
4026 "type %qT of template argument %qE depends "
4027 "on template parameters",
4036 /* We should only get here once. */
4037 gcc_assert (!COMPLETE_TYPE_P (type));
4039 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)
4040 = tree_cons (specargs, inner_parms,
4041 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl));
4042 TREE_TYPE (DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)) = type;
4046 /* Check that a template declaration's use of default arguments and
4047 parameter packs is not invalid. Here, PARMS are the template
4048 parameters. IS_PRIMARY is nonzero if DECL is the thing declared by
4049 a primary template. IS_PARTIAL is nonzero if DECL is a partial
4053 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4054 declaration (but not a definition); 1 indicates a declaration, 2
4055 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4056 emitted for extraneous default arguments.
4058 Returns TRUE if there were no errors found, FALSE otherwise. */
4061 check_default_tmpl_args (tree decl, tree parms, int is_primary,
4062 int is_partial, int is_friend_decl)
4065 int last_level_to_check;
4067 bool no_errors = true;
4071 A default template-argument shall not be specified in a
4072 function template declaration or a function template definition, nor
4073 in the template-parameter-list of the definition of a member of a
4076 if (TREE_CODE (CP_DECL_CONTEXT (decl)) == FUNCTION_DECL)
4077 /* You can't have a function template declaration in a local
4078 scope, nor you can you define a member of a class template in a
4082 if (current_class_type
4083 && !TYPE_BEING_DEFINED (current_class_type)
4084 && DECL_LANG_SPECIFIC (decl)
4085 && DECL_DECLARES_FUNCTION_P (decl)
4086 /* If this is either a friend defined in the scope of the class
4087 or a member function. */
4088 && (DECL_FUNCTION_MEMBER_P (decl)
4089 ? same_type_p (DECL_CONTEXT (decl), current_class_type)
4090 : DECL_FRIEND_CONTEXT (decl)
4091 ? same_type_p (DECL_FRIEND_CONTEXT (decl), current_class_type)
4093 /* And, if it was a member function, it really was defined in
4094 the scope of the class. */
4095 && (!DECL_FUNCTION_MEMBER_P (decl)
4096 || DECL_INITIALIZED_IN_CLASS_P (decl)))
4097 /* We already checked these parameters when the template was
4098 declared, so there's no need to do it again now. This function
4099 was defined in class scope, but we're processing it's body now
4100 that the class is complete. */
4103 /* Core issue 226 (C++0x only): the following only applies to class
4105 if ((cxx_dialect == cxx98) || TREE_CODE (decl) != FUNCTION_DECL)
4109 If a template-parameter has a default template-argument, all
4110 subsequent template-parameters shall have a default
4111 template-argument supplied. */
4112 for (parm_level = parms; parm_level; parm_level = TREE_CHAIN (parm_level))
4114 tree inner_parms = TREE_VALUE (parm_level);
4115 int ntparms = TREE_VEC_LENGTH (inner_parms);
4116 int seen_def_arg_p = 0;
4119 for (i = 0; i < ntparms; ++i)
4121 tree parm = TREE_VEC_ELT (inner_parms, i);
4123 if (parm == error_mark_node)
4126 if (TREE_PURPOSE (parm))
4128 else if (seen_def_arg_p
4129 && !template_parameter_pack_p (TREE_VALUE (parm)))
4131 error ("no default argument for %qD", TREE_VALUE (parm));
4132 /* For better subsequent error-recovery, we indicate that
4133 there should have been a default argument. */
4134 TREE_PURPOSE (parm) = error_mark_node;
4140 /* Don't complain about an enclosing partial
4142 && parm_level == parms
4143 && TREE_CODE (decl) == TYPE_DECL
4145 && template_parameter_pack_p (TREE_VALUE (parm)))
4147 /* A primary class template can only have one
4148 parameter pack, at the end of the template
4151 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL)
4152 error ("parameter pack %qE must be at the end of the"
4153 " template parameter list", TREE_VALUE (parm));
4155 error ("parameter pack %qT must be at the end of the"
4156 " template parameter list",
4157 TREE_TYPE (TREE_VALUE (parm)));
4159 TREE_VALUE (TREE_VEC_ELT (inner_parms, i))
4167 if (((cxx_dialect == cxx98) && TREE_CODE (decl) != TYPE_DECL)
4171 /* For an ordinary class template, default template arguments are
4172 allowed at the innermost level, e.g.:
4173 template <class T = int>
4175 but, in a partial specialization, they're not allowed even
4176 there, as we have in [temp.class.spec]:
4178 The template parameter list of a specialization shall not
4179 contain default template argument values.
4181 So, for a partial specialization, or for a function template
4182 (in C++98/C++03), we look at all of them. */
4185 /* But, for a primary class template that is not a partial
4186 specialization we look at all template parameters except the
4188 parms = TREE_CHAIN (parms);
4190 /* Figure out what error message to issue. */
4191 if (is_friend_decl == 2)
4192 msg = G_("default template arguments may not be used in function template "
4193 "friend re-declaration");
4194 else if (is_friend_decl)
4195 msg = G_("default template arguments may not be used in function template "
4196 "friend declarations");
4197 else if (TREE_CODE (decl) == FUNCTION_DECL && (cxx_dialect == cxx98))
4198 msg = G_("default template arguments may not be used in function templates "
4199 "without -std=c++0x or -std=gnu++0x");
4200 else if (is_partial)
4201 msg = G_("default template arguments may not be used in "
4202 "partial specializations");
4204 msg = G_("default argument for template parameter for class enclosing %qD");
4206 if (current_class_type && TYPE_BEING_DEFINED (current_class_type))
4207 /* If we're inside a class definition, there's no need to
4208 examine the parameters to the class itself. On the one
4209 hand, they will be checked when the class is defined, and,
4210 on the other, default arguments are valid in things like:
4211 template <class T = double>
4212 struct S { template <class U> void f(U); };
4213 Here the default argument for `S' has no bearing on the
4214 declaration of `f'. */
4215 last_level_to_check = template_class_depth (current_class_type) + 1;
4217 /* Check everything. */
4218 last_level_to_check = 0;
4220 for (parm_level = parms;
4221 parm_level && TMPL_PARMS_DEPTH (parm_level) >= last_level_to_check;
4222 parm_level = TREE_CHAIN (parm_level))
4224 tree inner_parms = TREE_VALUE (parm_level);
4228 ntparms = TREE_VEC_LENGTH (inner_parms);
4229 for (i = 0; i < ntparms; ++i)
4231 if (TREE_VEC_ELT (inner_parms, i) == error_mark_node)
4234 if (TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)))
4239 if (is_friend_decl == 2)
4246 /* Clear out the default argument so that we are not
4248 TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)) = NULL_TREE;
4252 /* At this point, if we're still interested in issuing messages,
4253 they must apply to classes surrounding the object declared. */
4255 msg = G_("default argument for template parameter for class "
4262 /* Worker for push_template_decl_real, called via
4263 for_each_template_parm. DATA is really an int, indicating the
4264 level of the parameters we are interested in. If T is a template
4265 parameter of that level, return nonzero. */
4268 template_parm_this_level_p (tree t, void* data)
4270 int this_level = *(int *)data;
4273 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
4274 level = TEMPLATE_PARM_LEVEL (t);
4276 level = TEMPLATE_TYPE_LEVEL (t);
4277 return level == this_level;
4280 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4281 parameters given by current_template_args, or reuses a
4282 previously existing one, if appropriate. Returns the DECL, or an
4283 equivalent one, if it is replaced via a call to duplicate_decls.
4285 If IS_FRIEND is true, DECL is a friend declaration. */
4288 push_template_decl_real (tree decl, bool is_friend)
4296 int new_template_p = 0;
4297 /* True if the template is a member template, in the sense of
4299 bool member_template_p = false;
4301 if (decl == error_mark_node || !current_template_parms)
4302 return error_mark_node;
4304 /* See if this is a partial specialization. */
4305 is_partial = (DECL_IMPLICIT_TYPEDEF_P (decl)
4306 && TREE_CODE (TREE_TYPE (decl)) != ENUMERAL_TYPE
4307 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)));
4309 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_FRIEND_P (decl))
4313 /* For a friend, we want the context of the friend function, not
4314 the type of which it is a friend. */
4315 ctx = DECL_CONTEXT (decl);
4316 else if (CP_DECL_CONTEXT (decl)
4317 && TREE_CODE (CP_DECL_CONTEXT (decl)) != NAMESPACE_DECL)
4318 /* In the case of a virtual function, we want the class in which
4320 ctx = CP_DECL_CONTEXT (decl);
4322 /* Otherwise, if we're currently defining some class, the DECL
4323 is assumed to be a member of the class. */
4324 ctx = current_scope ();
4326 if (ctx && TREE_CODE (ctx) == NAMESPACE_DECL)
4329 if (!DECL_CONTEXT (decl))
4330 DECL_CONTEXT (decl) = FROB_CONTEXT (current_namespace);
4332 /* See if this is a primary template. */
4333 if (is_friend && ctx)
4334 /* A friend template that specifies a class context, i.e.
4335 template <typename T> friend void A<T>::f();
4339 primary = template_parm_scope_p ();
4343 if (DECL_CLASS_SCOPE_P (decl))
4344 member_template_p = true;
4345 if (TREE_CODE (decl) == TYPE_DECL
4346 && ANON_AGGRNAME_P (DECL_NAME (decl)))
4348 error ("template class without a name");
4349 return error_mark_node;
4351 else if (TREE_CODE (decl) == FUNCTION_DECL)
4353 if (DECL_DESTRUCTOR_P (decl))
4357 A destructor shall not be a member template. */
4358 error ("destructor %qD declared as member template", decl);
4359 return error_mark_node;
4361 if (NEW_DELETE_OPNAME_P (DECL_NAME (decl))
4362 && (!TYPE_ARG_TYPES (TREE_TYPE (decl))
4363 || TYPE_ARG_TYPES (TREE_TYPE (decl)) == void_list_node
4364 || !TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (decl)))
4365 || (TREE_CHAIN (TYPE_ARG_TYPES ((TREE_TYPE (decl))))
4366 == void_list_node)))
4368 /* [basic.stc.dynamic.allocation]
4370 An allocation function can be a function
4371 template. ... Template allocation functions shall
4372 have two or more parameters. */
4373 error ("invalid template declaration of %qD", decl);
4374 return error_mark_node;
4377 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4378 && CLASS_TYPE_P (TREE_TYPE (decl)))
4382 error ("template declaration of %q#D", decl);
4383 return error_mark_node;
4387 /* Check to see that the rules regarding the use of default
4388 arguments are not being violated. */
4389 check_default_tmpl_args (decl, current_template_parms,
4390 primary, is_partial, /*is_friend_decl=*/0);
4392 /* Ensure that there are no parameter packs in the type of this
4393 declaration that have not been expanded. */
4394 if (TREE_CODE (decl) == FUNCTION_DECL)
4396 /* Check each of the arguments individually to see if there are
4397 any bare parameter packs. */
4398 tree type = TREE_TYPE (decl);
4399 tree arg = DECL_ARGUMENTS (decl);
4400 tree argtype = TYPE_ARG_TYPES (type);
4402 while (arg && argtype)
4404 if (!FUNCTION_PARAMETER_PACK_P (arg)
4405 && check_for_bare_parameter_packs (TREE_TYPE (arg)))
4407 /* This is a PARM_DECL that contains unexpanded parameter
4408 packs. We have already complained about this in the
4409 check_for_bare_parameter_packs call, so just replace
4410 these types with ERROR_MARK_NODE. */
4411 TREE_TYPE (arg) = error_mark_node;
4412 TREE_VALUE (argtype) = error_mark_node;
4415 arg = TREE_CHAIN (arg);
4416 argtype = TREE_CHAIN (argtype);
4419 /* Check for bare parameter packs in the return type and the
4420 exception specifiers. */
4421 if (check_for_bare_parameter_packs (TREE_TYPE (type)))
4422 /* Errors were already issued, set return type to int
4423 as the frontend doesn't expect error_mark_node as
4425 TREE_TYPE (type) = integer_type_node;
4426 if (check_for_bare_parameter_packs (TYPE_RAISES_EXCEPTIONS (type)))
4427 TYPE_RAISES_EXCEPTIONS (type) = NULL_TREE;
4429 else if (check_for_bare_parameter_packs (TREE_TYPE (decl)))
4431 TREE_TYPE (decl) = error_mark_node;
4432 return error_mark_node;
4436 return process_partial_specialization (decl);
4438 args = current_template_args ();
4441 || TREE_CODE (ctx) == FUNCTION_DECL
4442 || (CLASS_TYPE_P (ctx) && TYPE_BEING_DEFINED (ctx))
4443 || (is_friend && !DECL_TEMPLATE_INFO (decl)))
4445 if (DECL_LANG_SPECIFIC (decl)
4446 && DECL_TEMPLATE_INFO (decl)
4447 && DECL_TI_TEMPLATE (decl))
4448 tmpl = DECL_TI_TEMPLATE (decl);
4449 /* If DECL is a TYPE_DECL for a class-template, then there won't
4450 be DECL_LANG_SPECIFIC. The information equivalent to
4451 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4452 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4453 && TYPE_TEMPLATE_INFO (TREE_TYPE (decl))
4454 && TYPE_TI_TEMPLATE (TREE_TYPE (decl)))
4456 /* Since a template declaration already existed for this
4457 class-type, we must be redeclaring it here. Make sure
4458 that the redeclaration is valid. */
4459 redeclare_class_template (TREE_TYPE (decl),
4460 current_template_parms);
4461 /* We don't need to create a new TEMPLATE_DECL; just use the
4462 one we already had. */
4463 tmpl = TYPE_TI_TEMPLATE (TREE_TYPE (decl));
4467 tmpl = build_template_decl (decl, current_template_parms,
4471 if (DECL_LANG_SPECIFIC (decl)
4472 && DECL_TEMPLATE_SPECIALIZATION (decl))
4474 /* A specialization of a member template of a template
4476 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
4477 DECL_TEMPLATE_INFO (tmpl) = DECL_TEMPLATE_INFO (decl);
4478 DECL_TEMPLATE_INFO (decl) = NULL_TREE;
4484 tree a, t, current, parms;
4486 tree tinfo = get_template_info (decl);
4490 error ("template definition of non-template %q#D", decl);
4491 return error_mark_node;
4494 tmpl = TI_TEMPLATE (tinfo);
4496 if (DECL_FUNCTION_TEMPLATE_P (tmpl)
4497 && DECL_TEMPLATE_INFO (decl) && DECL_TI_ARGS (decl)
4498 && DECL_TEMPLATE_SPECIALIZATION (decl)
4499 && DECL_MEMBER_TEMPLATE_P (tmpl))
4503 /* The declaration is a specialization of a member
4504 template, declared outside the class. Therefore, the
4505 innermost template arguments will be NULL, so we
4506 replace them with the arguments determined by the
4507 earlier call to check_explicit_specialization. */
4508 args = DECL_TI_ARGS (decl);
4511 = build_template_decl (decl, current_template_parms,
4513 DECL_TEMPLATE_RESULT (new_tmpl) = decl;
4514 TREE_TYPE (new_tmpl) = TREE_TYPE (decl);
4515 DECL_TI_TEMPLATE (decl) = new_tmpl;
4516 SET_DECL_TEMPLATE_SPECIALIZATION (new_tmpl);
4517 DECL_TEMPLATE_INFO (new_tmpl)
4518 = build_template_info (tmpl, args);
4520 register_specialization (new_tmpl,
4521 most_general_template (tmpl),
4527 /* Make sure the template headers we got make sense. */
4529 parms = DECL_TEMPLATE_PARMS (tmpl);
4530 i = TMPL_PARMS_DEPTH (parms);
4531 if (TMPL_ARGS_DEPTH (args) != i)
4533 error ("expected %d levels of template parms for %q#D, got %d",
4534 i, decl, TMPL_ARGS_DEPTH (args));
4537 for (current = decl; i > 0; --i, parms = TREE_CHAIN (parms))
4539 a = TMPL_ARGS_LEVEL (args, i);
4540 t = INNERMOST_TEMPLATE_PARMS (parms);
4542 if (TREE_VEC_LENGTH (t) != TREE_VEC_LENGTH (a))
4544 if (current == decl)
4545 error ("got %d template parameters for %q#D",
4546 TREE_VEC_LENGTH (a), decl);
4548 error ("got %d template parameters for %q#T",
4549 TREE_VEC_LENGTH (a), current);
4550 error (" but %d required", TREE_VEC_LENGTH (t));
4551 return error_mark_node;
4554 if (current == decl)
4556 else if (current == NULL_TREE)
4557 /* Can happen in erroneous input. */
4560 current = (TYPE_P (current)
4561 ? TYPE_CONTEXT (current)
4562 : DECL_CONTEXT (current));
4565 /* Check that the parms are used in the appropriate qualifying scopes
4566 in the declarator. */
4567 if (!comp_template_args
4569 TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (tmpl)))))
4572 template arguments to %qD do not match original template %qD",
4573 decl, DECL_TEMPLATE_RESULT (tmpl));
4574 if (!uses_template_parms (TI_ARGS (tinfo)))
4575 inform (input_location, "use template<> for an explicit specialization");
4576 /* Avoid crash in import_export_decl. */
4577 DECL_INTERFACE_KNOWN (decl) = 1;
4578 return error_mark_node;
4582 DECL_TEMPLATE_RESULT (tmpl) = decl;
4583 TREE_TYPE (tmpl) = TREE_TYPE (decl);
4585 /* Push template declarations for global functions and types. Note
4586 that we do not try to push a global template friend declared in a
4587 template class; such a thing may well depend on the template
4588 parameters of the class. */
4589 if (new_template_p && !ctx
4590 && !(is_friend && template_class_depth (current_class_type) > 0))
4592 tmpl = pushdecl_namespace_level (tmpl, is_friend);
4593 if (tmpl == error_mark_node)
4594 return error_mark_node;
4596 /* Hide template friend classes that haven't been declared yet. */
4597 if (is_friend && TREE_CODE (decl) == TYPE_DECL)
4599 DECL_ANTICIPATED (tmpl) = 1;
4600 DECL_FRIEND_P (tmpl) = 1;
4606 tree parms = DECL_TEMPLATE_PARMS (tmpl);
4609 DECL_PRIMARY_TEMPLATE (tmpl) = tmpl;
4610 if (DECL_CONV_FN_P (tmpl))
4612 int depth = TMPL_PARMS_DEPTH (parms);
4614 /* It is a conversion operator. See if the type converted to
4615 depends on innermost template operands. */
4617 if (uses_template_parms_level (TREE_TYPE (TREE_TYPE (tmpl)),
4619 DECL_TEMPLATE_CONV_FN_P (tmpl) = 1;
4622 /* Give template template parms a DECL_CONTEXT of the template
4623 for which they are a parameter. */
4624 parms = INNERMOST_TEMPLATE_PARMS (parms);
4625 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
4627 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
4628 if (TREE_CODE (parm) == TEMPLATE_DECL)
4629 DECL_CONTEXT (parm) = tmpl;
4633 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
4634 back to its most general template. If TMPL is a specialization,
4635 ARGS may only have the innermost set of arguments. Add the missing
4636 argument levels if necessary. */
4637 if (DECL_TEMPLATE_INFO (tmpl))
4638 args = add_outermost_template_args (DECL_TI_ARGS (tmpl), args);
4640 info = build_template_info (tmpl, args);
4642 if (DECL_IMPLICIT_TYPEDEF_P (decl))
4643 SET_TYPE_TEMPLATE_INFO (TREE_TYPE (tmpl), info);
4644 else if (DECL_LANG_SPECIFIC (decl))
4645 DECL_TEMPLATE_INFO (decl) = info;
4647 return DECL_TEMPLATE_RESULT (tmpl);
4651 push_template_decl (tree decl)
4653 return push_template_decl_real (decl, false);
4656 /* Called when a class template TYPE is redeclared with the indicated
4657 template PARMS, e.g.:
4659 template <class T> struct S;
4660 template <class T> struct S {}; */
4663 redeclare_class_template (tree type, tree parms)
4669 if (!TYPE_TEMPLATE_INFO (type))
4671 error ("%qT is not a template type", type);
4675 tmpl = TYPE_TI_TEMPLATE (type);
4676 if (!PRIMARY_TEMPLATE_P (tmpl))
4677 /* The type is nested in some template class. Nothing to worry
4678 about here; there are no new template parameters for the nested
4684 error ("template specifiers not specified in declaration of %qD",
4689 parms = INNERMOST_TEMPLATE_PARMS (parms);
4690 tmpl_parms = DECL_INNERMOST_TEMPLATE_PARMS (tmpl);
4692 if (TREE_VEC_LENGTH (parms) != TREE_VEC_LENGTH (tmpl_parms))
4694 error_n (input_location, TREE_VEC_LENGTH (parms),
4695 "redeclared with %d template parameter",
4696 "redeclared with %d template parameters",
4697 TREE_VEC_LENGTH (parms));
4698 inform_n (input_location, TREE_VEC_LENGTH (tmpl_parms),
4699 "previous declaration %q+D used %d template parameter",
4700 "previous declaration %q+D used %d template parameters",
4701 tmpl, TREE_VEC_LENGTH (tmpl_parms));
4705 for (i = 0; i < TREE_VEC_LENGTH (tmpl_parms); ++i)
4712 if (TREE_VEC_ELT (tmpl_parms, i) == error_mark_node
4713 || TREE_VEC_ELT (parms, i) == error_mark_node)
4716 tmpl_parm = TREE_VALUE (TREE_VEC_ELT (tmpl_parms, i));
4717 if (tmpl_parm == error_mark_node)
4720 parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
4721 tmpl_default = TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i));
4722 parm_default = TREE_PURPOSE (TREE_VEC_ELT (parms, i));
4724 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
4726 if (TREE_CODE (tmpl_parm) != TREE_CODE (parm)
4727 || (TREE_CODE (tmpl_parm) != TYPE_DECL
4728 && !same_type_p (TREE_TYPE (tmpl_parm), TREE_TYPE (parm)))
4729 || (TREE_CODE (tmpl_parm) != PARM_DECL
4730 && (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (tmpl_parm))
4731 != TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm))))
4732 || (TREE_CODE (tmpl_parm) == PARM_DECL
4733 && (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (tmpl_parm))
4734 != TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))))
4736 error ("template parameter %q+#D", tmpl_parm);
4737 error ("redeclared here as %q#D", parm);
4741 if (tmpl_default != NULL_TREE && parm_default != NULL_TREE)
4743 /* We have in [temp.param]:
4745 A template-parameter may not be given default arguments
4746 by two different declarations in the same scope. */
4747 error_at (input_location, "redefinition of default argument for %q#D", parm);
4748 inform (DECL_SOURCE_LOCATION (tmpl_parm),
4749 "original definition appeared here");
4753 if (parm_default != NULL_TREE)
4754 /* Update the previous template parameters (which are the ones
4755 that will really count) with the new default value. */
4756 TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i)) = parm_default;
4757 else if (tmpl_default != NULL_TREE)
4758 /* Update the new parameters, too; they'll be used as the
4759 parameters for any members. */
4760 TREE_PURPOSE (TREE_VEC_ELT (parms, i)) = tmpl_default;
4766 /* Simplify EXPR if it is a non-dependent expression. Returns the
4767 (possibly simplified) expression. */
4770 fold_non_dependent_expr (tree expr)
4772 if (expr == NULL_TREE)
4775 /* If we're in a template, but EXPR isn't value dependent, simplify
4776 it. We're supposed to treat:
4778 template <typename T> void f(T[1 + 1]);
4779 template <typename T> void f(T[2]);
4781 as two declarations of the same function, for example. */
4782 if (processing_template_decl
4783 && !type_dependent_expression_p (expr)
4784 && !value_dependent_expression_p (expr))
4786 HOST_WIDE_INT saved_processing_template_decl;
4788 saved_processing_template_decl = processing_template_decl;
4789 processing_template_decl = 0;
4790 expr = tsubst_copy_and_build (expr,
4793 /*in_decl=*/NULL_TREE,
4794 /*function_p=*/false,
4795 /*integral_constant_expression_p=*/true);
4796 processing_template_decl = saved_processing_template_decl;
4801 /* EXPR is an expression which is used in a constant-expression context.
4802 For instance, it could be a VAR_DECL with a constant initializer.
4803 Extract the innermost constant expression.
4805 This is basically a more powerful version of
4806 integral_constant_value, which can be used also in templates where
4807 initializers can maintain a syntactic rather than semantic form
4808 (even if they are non-dependent, for access-checking purposes). */
4811 fold_decl_constant_value (tree expr)
4813 tree const_expr = expr;
4816 expr = fold_non_dependent_expr (const_expr);
4817 const_expr = integral_constant_value (expr);
4819 while (expr != const_expr);
4824 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
4825 must be a function or a pointer-to-function type, as specified
4826 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
4827 and check that the resulting function has external linkage. */
4830 convert_nontype_argument_function (tree type, tree expr)
4835 fn = instantiate_type (type, fns, tf_none);
4836 if (fn == error_mark_node)
4837 return error_mark_node;
4840 if (TREE_CODE (fn_no_ptr) == ADDR_EXPR)
4841 fn_no_ptr = TREE_OPERAND (fn_no_ptr, 0);
4842 if (TREE_CODE (fn_no_ptr) == BASELINK)
4843 fn_no_ptr = BASELINK_FUNCTIONS (fn_no_ptr);
4845 /* [temp.arg.nontype]/1
4847 A template-argument for a non-type, non-template template-parameter
4850 -- the address of an object or function with external linkage. */
4851 if (!DECL_EXTERNAL_LINKAGE_P (fn_no_ptr))
4853 error ("%qE is not a valid template argument for type %qT "
4854 "because function %qD has not external linkage",
4855 expr, type, fn_no_ptr);
4862 /* Subroutine of convert_nontype_argument.
4863 Check if EXPR of type TYPE is a valid pointer-to-member constant.
4864 Emit an error otherwise. */
4867 check_valid_ptrmem_cst_expr (tree type, tree expr)
4870 if (expr && (null_ptr_cst_p (expr) || TREE_CODE (expr) == PTRMEM_CST))
4872 error ("%qE is not a valid template argument for type %qT",
4874 error ("it must be a pointer-to-member of the form `&X::Y'");
4878 /* Attempt to convert the non-type template parameter EXPR to the
4879 indicated TYPE. If the conversion is successful, return the
4880 converted value. If the conversion is unsuccessful, return
4881 NULL_TREE if we issued an error message, or error_mark_node if we
4882 did not. We issue error messages for out-and-out bad template
4883 parameters, but not simply because the conversion failed, since we
4884 might be just trying to do argument deduction. Both TYPE and EXPR
4885 must be non-dependent.
4887 The conversion follows the special rules described in
4888 [temp.arg.nontype], and it is much more strict than an implicit
4891 This function is called twice for each template argument (see
4892 lookup_template_class for a more accurate description of this
4893 problem). This means that we need to handle expressions which
4894 are not valid in a C++ source, but can be created from the
4895 first call (for instance, casts to perform conversions). These
4896 hacks can go away after we fix the double coercion problem. */
4899 convert_nontype_argument (tree type, tree expr)
4903 /* Detect immediately string literals as invalid non-type argument.
4904 This special-case is not needed for correctness (we would easily
4905 catch this later), but only to provide better diagnostic for this
4906 common user mistake. As suggested by DR 100, we do not mention
4907 linkage issues in the diagnostic as this is not the point. */
4908 if (TREE_CODE (expr) == STRING_CST)
4910 error ("%qE is not a valid template argument for type %qT "
4911 "because string literals can never be used in this context",
4916 /* If we are in a template, EXPR may be non-dependent, but still
4917 have a syntactic, rather than semantic, form. For example, EXPR
4918 might be a SCOPE_REF, rather than the VAR_DECL to which the
4919 SCOPE_REF refers. Preserving the qualifying scope is necessary
4920 so that access checking can be performed when the template is
4921 instantiated -- but here we need the resolved form so that we can
4922 convert the argument. */
4923 expr = fold_non_dependent_expr (expr);
4924 if (error_operand_p (expr))
4925 return error_mark_node;
4926 expr_type = TREE_TYPE (expr);
4928 /* HACK: Due to double coercion, we can get a
4929 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
4930 which is the tree that we built on the first call (see
4931 below when coercing to reference to object or to reference to
4932 function). We just strip everything and get to the arg.
4933 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
4935 if (TREE_CODE (expr) == NOP_EXPR)
4937 if (TYPE_REF_OBJ_P (type) || TYPE_REFFN_P (type))
4939 /* ??? Maybe we could use convert_from_reference here, but we
4940 would need to relax its constraints because the NOP_EXPR
4941 could actually change the type to something more cv-qualified,
4942 and this is not folded by convert_from_reference. */
4943 tree addr = TREE_OPERAND (expr, 0);
4944 gcc_assert (TREE_CODE (expr_type) == REFERENCE_TYPE);
4945 gcc_assert (TREE_CODE (addr) == ADDR_EXPR);
4946 gcc_assert (TREE_CODE (TREE_TYPE (addr)) == POINTER_TYPE);
4947 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4948 (TREE_TYPE (expr_type),
4949 TREE_TYPE (TREE_TYPE (addr))));
4951 expr = TREE_OPERAND (addr, 0);
4952 expr_type = TREE_TYPE (expr);
4955 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
4956 parameter is a pointer to object, through decay and
4957 qualification conversion. Let's strip everything. */
4958 else if (TYPE_PTROBV_P (type))
4961 gcc_assert (TREE_CODE (expr) == ADDR_EXPR);
4962 gcc_assert (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE);
4963 /* Skip the ADDR_EXPR only if it is part of the decay for
4964 an array. Otherwise, it is part of the original argument
4965 in the source code. */
4966 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == ARRAY_TYPE)
4967 expr = TREE_OPERAND (expr, 0);
4968 expr_type = TREE_TYPE (expr);
4972 /* [temp.arg.nontype]/5, bullet 1
4974 For a non-type template-parameter of integral or enumeration type,
4975 integral promotions (_conv.prom_) and integral conversions
4976 (_conv.integral_) are applied. */
4977 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
4979 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (expr_type))
4980 return error_mark_node;
4982 expr = fold_decl_constant_value (expr);
4983 /* Notice that there are constant expressions like '4 % 0' which
4984 do not fold into integer constants. */
4985 if (TREE_CODE (expr) != INTEGER_CST)
4987 error ("%qE is not a valid template argument for type %qT "
4988 "because it is a non-constant expression", expr, type);
4992 /* At this point, an implicit conversion does what we want,
4993 because we already know that the expression is of integral
4995 expr = ocp_convert (type, expr, CONV_IMPLICIT, LOOKUP_PROTECT);
4996 if (expr == error_mark_node)
4997 return error_mark_node;
4999 /* Conversion was allowed: fold it to a bare integer constant. */
5002 /* [temp.arg.nontype]/5, bullet 2
5004 For a non-type template-parameter of type pointer to object,
5005 qualification conversions (_conv.qual_) and the array-to-pointer
5006 conversion (_conv.array_) are applied. */
5007 else if (TYPE_PTROBV_P (type))
5009 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5011 A template-argument for a non-type, non-template template-parameter
5012 shall be one of: [...]
5014 -- the name of a non-type template-parameter;
5015 -- the address of an object or function with external linkage, [...]
5016 expressed as "& id-expression" where the & is optional if the name
5017 refers to a function or array, or if the corresponding
5018 template-parameter is a reference.
5020 Here, we do not care about functions, as they are invalid anyway
5021 for a parameter of type pointer-to-object. */
5023 if (DECL_P (expr) && DECL_TEMPLATE_PARM_P (expr))
5024 /* Non-type template parameters are OK. */
5026 else if (TREE_CODE (expr) != ADDR_EXPR
5027 && TREE_CODE (expr_type) != ARRAY_TYPE)
5029 if (TREE_CODE (expr) == VAR_DECL)
5031 error ("%qD is not a valid template argument "
5032 "because %qD is a variable, not the address of "
5037 /* Other values, like integer constants, might be valid
5038 non-type arguments of some other type. */
5039 return error_mark_node;
5045 decl = ((TREE_CODE (expr) == ADDR_EXPR)
5046 ? TREE_OPERAND (expr, 0) : expr);
5047 if (TREE_CODE (decl) != VAR_DECL)
5049 error ("%qE is not a valid template argument of type %qT "
5050 "because %qE is not a variable",
5054 else if (!DECL_EXTERNAL_LINKAGE_P (decl))
5056 error ("%qE is not a valid template argument of type %qT "
5057 "because %qD does not have external linkage",
5063 expr = decay_conversion (expr);
5064 if (expr == error_mark_node)
5065 return error_mark_node;
5067 expr = perform_qualification_conversions (type, expr);
5068 if (expr == error_mark_node)
5069 return error_mark_node;
5071 /* [temp.arg.nontype]/5, bullet 3
5073 For a non-type template-parameter of type reference to object, no
5074 conversions apply. The type referred to by the reference may be more
5075 cv-qualified than the (otherwise identical) type of the
5076 template-argument. The template-parameter is bound directly to the
5077 template-argument, which must be an lvalue. */
5078 else if (TYPE_REF_OBJ_P (type))
5080 if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type),
5082 return error_mark_node;
5084 if (!at_least_as_qualified_p (TREE_TYPE (type), expr_type))
5086 error ("%qE is not a valid template argument for type %qT "
5087 "because of conflicts in cv-qualification", expr, type);
5091 if (!real_lvalue_p (expr))
5093 error ("%qE is not a valid template argument for type %qT "
5094 "because it is not an lvalue", expr, type);
5098 /* [temp.arg.nontype]/1
5100 A template-argument for a non-type, non-template template-parameter
5101 shall be one of: [...]
5103 -- the address of an object or function with external linkage. */
5104 if (TREE_CODE (expr) == INDIRECT_REF
5105 && TYPE_REF_OBJ_P (TREE_TYPE (TREE_OPERAND (expr, 0))))
5107 expr = TREE_OPERAND (expr, 0);
5110 error ("%q#D is not a valid template argument for type %qT "
5111 "because a reference variable does not have a constant "
5112 "address", expr, type);
5119 error ("%qE is not a valid template argument for type %qT "
5120 "because it is not an object with external linkage",
5125 if (!DECL_EXTERNAL_LINKAGE_P (expr))
5127 error ("%qE is not a valid template argument for type %qT "
5128 "because object %qD has not external linkage",
5133 expr = build_nop (type, build_address (expr));
5135 /* [temp.arg.nontype]/5, bullet 4
5137 For a non-type template-parameter of type pointer to function, only
5138 the function-to-pointer conversion (_conv.func_) is applied. If the
5139 template-argument represents a set of overloaded functions (or a
5140 pointer to such), the matching function is selected from the set
5142 else if (TYPE_PTRFN_P (type))
5144 /* If the argument is a template-id, we might not have enough
5145 context information to decay the pointer. */
5146 if (!type_unknown_p (expr_type))
5148 expr = decay_conversion (expr);
5149 if (expr == error_mark_node)
5150 return error_mark_node;
5153 expr = convert_nontype_argument_function (type, expr);
5154 if (!expr || expr == error_mark_node)
5157 if (TREE_CODE (expr) != ADDR_EXPR)
5159 error ("%qE is not a valid template argument for type %qT", expr, type);
5160 error ("it must be the address of a function with external linkage");
5164 /* [temp.arg.nontype]/5, bullet 5
5166 For a non-type template-parameter of type reference to function, no
5167 conversions apply. If the template-argument represents a set of
5168 overloaded functions, the matching function is selected from the set
5170 else if (TYPE_REFFN_P (type))
5172 if (TREE_CODE (expr) == ADDR_EXPR)
5174 error ("%qE is not a valid template argument for type %qT "
5175 "because it is a pointer", expr, type);
5176 inform (input_location, "try using %qE instead", TREE_OPERAND (expr, 0));
5180 expr = convert_nontype_argument_function (TREE_TYPE (type), expr);
5181 if (!expr || expr == error_mark_node)
5184 expr = build_nop (type, build_address (expr));
5186 /* [temp.arg.nontype]/5, bullet 6
5188 For a non-type template-parameter of type pointer to member function,
5189 no conversions apply. If the template-argument represents a set of
5190 overloaded member functions, the matching member function is selected
5191 from the set (_over.over_). */
5192 else if (TYPE_PTRMEMFUNC_P (type))
5194 expr = instantiate_type (type, expr, tf_none);
5195 if (expr == error_mark_node)
5196 return error_mark_node;
5198 /* [temp.arg.nontype] bullet 1 says the pointer to member
5199 expression must be a pointer-to-member constant. */
5200 if (!check_valid_ptrmem_cst_expr (type, expr))
5201 return error_mark_node;
5203 /* There is no way to disable standard conversions in
5204 resolve_address_of_overloaded_function (called by
5205 instantiate_type). It is possible that the call succeeded by
5206 converting &B::I to &D::I (where B is a base of D), so we need
5207 to reject this conversion here.
5209 Actually, even if there was a way to disable standard conversions,
5210 it would still be better to reject them here so that we can
5211 provide a superior diagnostic. */
5212 if (!same_type_p (TREE_TYPE (expr), type))
5214 error ("%qE is not a valid template argument for type %qT "
5215 "because it is of type %qT", expr, type,
5217 /* If we are just one standard conversion off, explain. */
5218 if (can_convert (type, TREE_TYPE (expr)))
5219 inform (input_location,
5220 "standard conversions are not allowed in this context");
5224 /* [temp.arg.nontype]/5, bullet 7
5226 For a non-type template-parameter of type pointer to data member,
5227 qualification conversions (_conv.qual_) are applied. */
5228 else if (TYPE_PTRMEM_P (type))
5230 /* [temp.arg.nontype] bullet 1 says the pointer to member
5231 expression must be a pointer-to-member constant. */
5232 if (!check_valid_ptrmem_cst_expr (type, expr))
5233 return error_mark_node;
5235 expr = perform_qualification_conversions (type, expr);
5236 if (expr == error_mark_node)
5239 /* A template non-type parameter must be one of the above. */
5243 /* Sanity check: did we actually convert the argument to the
5245 gcc_assert (same_type_p (type, TREE_TYPE (expr)));
5249 /* Subroutine of coerce_template_template_parms, which returns 1 if
5250 PARM_PARM and ARG_PARM match using the rule for the template
5251 parameters of template template parameters. Both PARM and ARG are
5252 template parameters; the rest of the arguments are the same as for
5253 coerce_template_template_parms.
5256 coerce_template_template_parm (tree parm,
5258 tsubst_flags_t complain,
5262 if (arg == NULL_TREE || arg == error_mark_node
5263 || parm == NULL_TREE || parm == error_mark_node)
5266 if (TREE_CODE (arg) != TREE_CODE (parm))
5269 switch (TREE_CODE (parm))
5272 /* We encounter instantiations of templates like
5273 template <template <template <class> class> class TT>
5276 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
5277 tree argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
5279 if (!coerce_template_template_parms
5280 (parmparm, argparm, complain, in_decl, outer_args))
5286 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (arg))
5287 && !TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
5288 /* Argument is a parameter pack but parameter is not. */
5293 /* The tsubst call is used to handle cases such as
5295 template <int> class C {};
5296 template <class T, template <T> class TT> class D {};
5299 i.e. the parameter list of TT depends on earlier parameters. */
5300 if (!uses_template_parms (TREE_TYPE (arg))
5302 (tsubst (TREE_TYPE (parm), outer_args, complain, in_decl),
5306 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (arg))
5307 && !TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
5308 /* Argument is a parameter pack but parameter is not. */
5321 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
5322 template template parameters. Both PARM_PARMS and ARG_PARMS are
5323 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
5326 Consider the example:
5327 template <class T> class A;
5328 template<template <class U> class TT> class B;
5330 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
5331 the parameters to A, and OUTER_ARGS contains A. */
5334 coerce_template_template_parms (tree parm_parms,
5336 tsubst_flags_t complain,
5340 int nparms, nargs, i;
5344 gcc_assert (TREE_CODE (parm_parms) == TREE_VEC);
5345 gcc_assert (TREE_CODE (arg_parms) == TREE_VEC);
5347 nparms = TREE_VEC_LENGTH (parm_parms);
5348 nargs = TREE_VEC_LENGTH (arg_parms);
5350 /* Determine whether we have a parameter pack at the end of the
5351 template template parameter's template parameter list. */
5352 if (TREE_VEC_ELT (parm_parms, nparms - 1) != error_mark_node)
5354 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, nparms - 1));
5356 if (parm == error_mark_node)
5359 switch (TREE_CODE (parm))
5363 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
5368 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
5378 && !(variadic_p && nargs >= nparms - 1))
5381 /* Check all of the template parameters except the parameter pack at
5382 the end (if any). */
5383 for (i = 0; i < nparms - variadic_p; ++i)
5385 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node
5386 || TREE_VEC_ELT (arg_parms, i) == error_mark_node)
5389 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
5390 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
5392 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
5400 /* Check each of the template parameters in the template
5401 argument against the template parameter pack at the end of
5402 the template template parameter. */
5403 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node)
5406 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
5408 for (; i < nargs; ++i)
5410 if (TREE_VEC_ELT (arg_parms, i) == error_mark_node)
5413 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
5415 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
5424 /* Verifies that the deduced template arguments (in TARGS) for the
5425 template template parameters (in TPARMS) represent valid bindings,
5426 by comparing the template parameter list of each template argument
5427 to the template parameter list of its corresponding template
5428 template parameter, in accordance with DR150. This
5429 routine can only be called after all template arguments have been
5430 deduced. It will return TRUE if all of the template template
5431 parameter bindings are okay, FALSE otherwise. */
5433 template_template_parm_bindings_ok_p (tree tparms, tree targs)
5435 int i, ntparms = TREE_VEC_LENGTH (tparms);
5438 /* We're dealing with template parms in this process. */
5439 ++processing_template_decl;
5441 targs = INNERMOST_TEMPLATE_ARGS (targs);
5443 for (i = 0; i < ntparms; ++i)
5445 tree tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
5446 tree targ = TREE_VEC_ELT (targs, i);
5448 if (TREE_CODE (tparm) == TEMPLATE_DECL && targ)
5450 tree packed_args = NULL_TREE;
5453 if (ARGUMENT_PACK_P (targ))
5455 /* Look inside the argument pack. */
5456 packed_args = ARGUMENT_PACK_ARGS (targ);
5457 len = TREE_VEC_LENGTH (packed_args);
5460 for (idx = 0; idx < len; ++idx)
5462 tree targ_parms = NULL_TREE;
5465 /* Extract the next argument from the argument
5467 targ = TREE_VEC_ELT (packed_args, idx);
5469 if (PACK_EXPANSION_P (targ))
5470 /* Look at the pattern of the pack expansion. */
5471 targ = PACK_EXPANSION_PATTERN (targ);
5473 /* Extract the template parameters from the template
5475 if (TREE_CODE (targ) == TEMPLATE_DECL)
5476 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (targ);
5477 else if (TREE_CODE (targ) == TEMPLATE_TEMPLATE_PARM)
5478 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (TYPE_NAME (targ));
5480 /* Verify that we can coerce the template template
5481 parameters from the template argument to the template
5482 parameter. This requires an exact match. */
5484 && !coerce_template_template_parms
5485 (DECL_INNERMOST_TEMPLATE_PARMS (tparm),
5500 --processing_template_decl;
5504 /* Convert the indicated template ARG as necessary to match the
5505 indicated template PARM. Returns the converted ARG, or
5506 error_mark_node if the conversion was unsuccessful. Error and
5507 warning messages are issued under control of COMPLAIN. This
5508 conversion is for the Ith parameter in the parameter list. ARGS is
5509 the full set of template arguments deduced so far. */
5512 convert_template_argument (tree parm,
5515 tsubst_flags_t complain,
5521 int is_type, requires_type, is_tmpl_type, requires_tmpl_type;
5523 if (TREE_CODE (arg) == TREE_LIST
5524 && TREE_CODE (TREE_VALUE (arg)) == OFFSET_REF)
5526 /* The template argument was the name of some
5527 member function. That's usually
5528 invalid, but static members are OK. In any
5529 case, grab the underlying fields/functions
5530 and issue an error later if required. */
5531 orig_arg = TREE_VALUE (arg);
5532 TREE_TYPE (arg) = unknown_type_node;
5537 requires_tmpl_type = TREE_CODE (parm) == TEMPLATE_DECL;
5538 requires_type = (TREE_CODE (parm) == TYPE_DECL
5539 || requires_tmpl_type);
5541 /* When determining whether an argument pack expansion is a template,
5542 look at the pattern. */
5543 if (TREE_CODE (arg) == TYPE_PACK_EXPANSION)
5544 arg = PACK_EXPANSION_PATTERN (arg);
5546 /* Deal with an injected-class-name used as a template template arg. */
5547 if (requires_tmpl_type && CLASS_TYPE_P (arg))
5549 tree t = maybe_get_template_decl_from_type_decl (TYPE_NAME (arg));
5550 if (TREE_CODE (t) == TEMPLATE_DECL)
5552 if (complain & tf_warning_or_error)
5553 pedwarn (input_location, OPT_pedantic, "injected-class-name %qD"
5554 " used as template template argument", TYPE_NAME (arg));
5555 else if (flag_pedantic_errors)
5563 ((TREE_CODE (arg) == TEMPLATE_DECL
5564 && TREE_CODE (DECL_TEMPLATE_RESULT (arg)) == TYPE_DECL)
5565 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
5566 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE);
5569 && (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
5570 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE))
5571 arg = TYPE_STUB_DECL (arg);
5573 is_type = TYPE_P (arg) || is_tmpl_type;
5575 if (requires_type && ! is_type && TREE_CODE (arg) == SCOPE_REF
5576 && TREE_CODE (TREE_OPERAND (arg, 0)) == TEMPLATE_TYPE_PARM)
5578 permerror (input_location, "to refer to a type member of a template parameter, "
5579 "use %<typename %E%>", orig_arg);
5581 orig_arg = make_typename_type (TREE_OPERAND (arg, 0),
5582 TREE_OPERAND (arg, 1),
5584 complain & tf_error);
5588 if (is_type != requires_type)
5592 if (complain & tf_error)
5594 error ("type/value mismatch at argument %d in template "
5595 "parameter list for %qD",
5598 error (" expected a constant of type %qT, got %qT",
5600 (DECL_P (arg) ? DECL_NAME (arg) : orig_arg));
5601 else if (requires_tmpl_type)
5602 error (" expected a class template, got %qE", orig_arg);
5604 error (" expected a type, got %qE", orig_arg);
5607 return error_mark_node;
5609 if (is_tmpl_type ^ requires_tmpl_type)
5611 if (in_decl && (complain & tf_error))
5613 error ("type/value mismatch at argument %d in template "
5614 "parameter list for %qD",
5617 error (" expected a type, got %qT", DECL_NAME (arg));
5619 error (" expected a class template, got %qT", orig_arg);
5621 return error_mark_node;
5626 if (requires_tmpl_type)
5628 if (TREE_CODE (TREE_TYPE (arg)) == UNBOUND_CLASS_TEMPLATE)
5629 /* The number of argument required is not known yet.
5630 Just accept it for now. */
5631 val = TREE_TYPE (arg);
5634 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
5637 argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
5639 if (coerce_template_template_parms (parmparm, argparm,
5645 /* TEMPLATE_TEMPLATE_PARM node is preferred over
5647 if (val != error_mark_node)
5649 if (DECL_TEMPLATE_TEMPLATE_PARM_P (val))
5650 val = TREE_TYPE (val);
5651 if (TREE_CODE (orig_arg) == TYPE_PACK_EXPANSION)
5652 val = make_pack_expansion (val);
5657 if (in_decl && (complain & tf_error))
5659 error ("type/value mismatch at argument %d in "
5660 "template parameter list for %qD",
5662 error (" expected a template of type %qD, got %qT",
5666 val = error_mark_node;
5672 /* We only form one instance of each template specialization.
5673 Therefore, if we use a non-canonical variant (i.e., a
5674 typedef), any future messages referring to the type will use
5675 the typedef, which is confusing if those future uses do not
5676 themselves also use the typedef. */
5678 val = strip_typedefs (val);
5682 tree t = tsubst (TREE_TYPE (parm), args, complain, in_decl);
5684 if (invalid_nontype_parm_type_p (t, complain))
5685 return error_mark_node;
5687 if (template_parameter_pack_p (parm) && ARGUMENT_PACK_P (orig_arg))
5689 if (same_type_p (t, TREE_TYPE (orig_arg)))
5693 /* Not sure if this is reachable, but it doesn't hurt
5695 error ("type mismatch in nontype parameter pack");
5696 val = error_mark_node;
5699 else if (!uses_template_parms (orig_arg) && !uses_template_parms (t))
5700 /* We used to call digest_init here. However, digest_init
5701 will report errors, which we don't want when complain
5702 is zero. More importantly, digest_init will try too
5703 hard to convert things: for example, `0' should not be
5704 converted to pointer type at this point according to
5705 the standard. Accepting this is not merely an
5706 extension, since deciding whether or not these
5707 conversions can occur is part of determining which
5708 function template to call, or whether a given explicit
5709 argument specification is valid. */
5710 val = convert_nontype_argument (t, orig_arg);
5714 if (val == NULL_TREE)
5715 val = error_mark_node;
5716 else if (val == error_mark_node && (complain & tf_error))
5717 error ("could not convert template argument %qE to %qT", orig_arg, t);
5719 if (TREE_CODE (val) == SCOPE_REF)
5721 /* Strip typedefs from the SCOPE_REF. */
5722 tree type = strip_typedefs (TREE_TYPE (val));
5723 tree scope = strip_typedefs (TREE_OPERAND (val, 0));
5724 val = build_qualified_name (type, scope, TREE_OPERAND (val, 1),
5725 QUALIFIED_NAME_IS_TEMPLATE (val));
5732 /* Coerces the remaining template arguments in INNER_ARGS (from
5733 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
5734 Returns the coerced argument pack. PARM_IDX is the position of this
5735 parameter in the template parameter list. ARGS is the original
5736 template argument list. */
5738 coerce_template_parameter_pack (tree parms,
5746 tsubst_flags_t complain)
5748 tree parm = TREE_VEC_ELT (parms, parm_idx);
5749 int nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
5752 tree packed_types = NULL_TREE;
5754 if (arg_idx > nargs)
5757 packed_args = make_tree_vec (nargs - arg_idx);
5759 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL
5760 && uses_parameter_packs (TREE_TYPE (TREE_VALUE (parm))))
5762 /* When the template parameter is a non-type template
5763 parameter pack whose type uses parameter packs, we need
5764 to look at each of the template arguments
5765 separately. Build a vector of the types for these
5766 non-type template parameters in PACKED_TYPES. */
5768 = make_pack_expansion (TREE_TYPE (TREE_VALUE (parm)));
5769 packed_types = tsubst_pack_expansion (expansion, args,
5772 if (packed_types == error_mark_node)
5773 return error_mark_node;
5775 /* Check that we have the right number of arguments. */
5777 && !PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx))
5778 && nargs - arg_idx != TREE_VEC_LENGTH (packed_types))
5781 = TREE_VEC_LENGTH (parms) - 1 + TREE_VEC_LENGTH (packed_types);
5782 error ("wrong number of template arguments (%d, should be %d)",
5783 nargs, needed_parms);
5784 return error_mark_node;
5787 /* If we aren't able to check the actual arguments now
5788 (because they haven't been expanded yet), we can at least
5789 verify that all of the types used for the non-type
5790 template parameter pack are, in fact, valid for non-type
5791 template parameters. */
5793 && PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx)))
5795 int j, len = TREE_VEC_LENGTH (packed_types);
5796 for (j = 0; j < len; ++j)
5798 tree t = TREE_VEC_ELT (packed_types, j);
5799 if (invalid_nontype_parm_type_p (t, complain))
5800 return error_mark_node;
5805 /* Convert the remaining arguments, which will be a part of the
5806 parameter pack "parm". */
5807 for (; arg_idx < nargs; ++arg_idx)
5809 tree arg = TREE_VEC_ELT (inner_args, arg_idx);
5810 tree actual_parm = TREE_VALUE (parm);
5812 if (packed_types && !PACK_EXPANSION_P (arg))
5814 /* When we have a vector of types (corresponding to the
5815 non-type template parameter pack that uses parameter
5816 packs in its type, as mention above), and the
5817 argument is not an expansion (which expands to a
5818 currently unknown number of arguments), clone the
5819 parm and give it the next type in PACKED_TYPES. */
5820 actual_parm = copy_node (actual_parm);
5821 TREE_TYPE (actual_parm) =
5822 TREE_VEC_ELT (packed_types, arg_idx - parm_idx);
5825 if (arg != error_mark_node)
5826 arg = convert_template_argument (actual_parm,
5827 arg, new_args, complain, parm_idx,
5829 if (arg == error_mark_node)
5831 TREE_VEC_ELT (packed_args, arg_idx - parm_idx) = arg;
5834 if (TREE_CODE (TREE_VALUE (parm)) == TYPE_DECL
5835 || TREE_CODE (TREE_VALUE (parm)) == TEMPLATE_DECL)
5836 argument_pack = cxx_make_type (TYPE_ARGUMENT_PACK);
5839 argument_pack = make_node (NONTYPE_ARGUMENT_PACK);
5840 TREE_TYPE (argument_pack)
5841 = tsubst (TREE_TYPE (TREE_VALUE (parm)), new_args, complain, in_decl);
5842 TREE_CONSTANT (argument_pack) = 1;
5845 SET_ARGUMENT_PACK_ARGS (argument_pack, packed_args);
5846 #ifdef ENABLE_CHECKING
5847 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (packed_args,
5848 TREE_VEC_LENGTH (packed_args));
5850 return argument_pack;
5853 /* Convert all template arguments to their appropriate types, and
5854 return a vector containing the innermost resulting template
5855 arguments. If any error occurs, return error_mark_node. Error and
5856 warning messages are issued under control of COMPLAIN.
5858 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
5859 for arguments not specified in ARGS. Otherwise, if
5860 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
5861 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
5862 USE_DEFAULT_ARGS is false, then all arguments must be specified in
5866 coerce_template_parms (tree parms,
5869 tsubst_flags_t complain,
5870 bool require_all_args,
5871 bool use_default_args)
5873 int nparms, nargs, parm_idx, arg_idx, lost = 0;
5876 tree new_inner_args;
5877 int saved_unevaluated_operand;
5878 int saved_inhibit_evaluation_warnings;
5880 /* When used as a boolean value, indicates whether this is a
5881 variadic template parameter list. Since it's an int, we can also
5882 subtract it from nparms to get the number of non-variadic
5886 nparms = TREE_VEC_LENGTH (parms);
5888 /* Determine if there are any parameter packs. */
5889 for (parm_idx = 0; parm_idx < nparms; ++parm_idx)
5891 tree tparm = TREE_VALUE (TREE_VEC_ELT (parms, parm_idx));
5892 if (template_parameter_pack_p (tparm))
5896 inner_args = INNERMOST_TEMPLATE_ARGS (args);
5897 /* If there are 0 or 1 parameter packs, we need to expand any argument
5898 packs so that we can deduce a parameter pack from some non-packed args
5899 followed by an argument pack, as in variadic85.C. If there are more
5900 than that, we need to leave argument packs intact so the arguments are
5901 assigned to the right parameter packs. This should only happen when
5902 dealing with a nested class inside a partial specialization of a class
5903 template, as in variadic92.C. */
5904 if (variadic_p <= 1)
5905 inner_args = expand_template_argument_pack (inner_args);
5907 nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
5908 if ((nargs > nparms && !variadic_p)
5909 || (nargs < nparms - variadic_p
5911 && (!use_default_args
5912 || (TREE_VEC_ELT (parms, nargs) != error_mark_node
5913 && !TREE_PURPOSE (TREE_VEC_ELT (parms, nargs))))))
5915 if (complain & tf_error)
5917 const char *or_more = "";
5920 or_more = " or more";
5924 error ("wrong number of template arguments (%d, should be %d%s)",
5925 nargs, nparms, or_more);
5928 error ("provided for %q+D", in_decl);
5931 return error_mark_node;
5934 /* We need to evaluate the template arguments, even though this
5935 template-id may be nested within a "sizeof". */
5936 saved_unevaluated_operand = cp_unevaluated_operand;
5937 cp_unevaluated_operand = 0;
5938 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
5939 c_inhibit_evaluation_warnings = 0;
5940 new_inner_args = make_tree_vec (nparms);
5941 new_args = add_outermost_template_args (args, new_inner_args);
5942 for (parm_idx = 0, arg_idx = 0; parm_idx < nparms; parm_idx++, arg_idx++)
5947 /* Get the Ith template parameter. */
5948 parm = TREE_VEC_ELT (parms, parm_idx);
5950 if (parm == error_mark_node)
5952 TREE_VEC_ELT (new_inner_args, arg_idx) = error_mark_node;
5956 /* Calculate the next argument. */
5957 if (arg_idx < nargs)
5958 arg = TREE_VEC_ELT (inner_args, arg_idx);
5962 if (template_parameter_pack_p (TREE_VALUE (parm))
5963 && !(arg && ARGUMENT_PACK_P (arg)))
5965 /* All remaining arguments will be placed in the
5966 template parameter pack PARM. */
5967 arg = coerce_template_parameter_pack (parms, parm_idx, args,
5968 inner_args, arg_idx,
5972 /* Store this argument. */
5973 if (arg == error_mark_node)
5975 TREE_VEC_ELT (new_inner_args, parm_idx) = arg;
5977 /* We are done with all of the arguments. */
5984 if (PACK_EXPANSION_P (arg))
5986 if (complain & tf_error)
5988 /* FIXME this restriction was removed by N2555; see
5990 /* If ARG is a pack expansion, but PARM is not a
5991 template parameter pack (if it were, we would have
5992 handled it above), we're trying to expand into a
5993 fixed-length argument list. */
5994 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
5995 sorry ("cannot expand %<%E%> into a fixed-length "
5996 "argument list", arg);
5998 sorry ("cannot expand %<%T%> into a fixed-length "
5999 "argument list", arg);
6001 return error_mark_node;
6004 else if (require_all_args)
6006 /* There must be a default arg in this case. */
6007 arg = tsubst_template_arg (TREE_PURPOSE (parm), new_args,
6009 /* The position of the first default template argument,
6010 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6012 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args))
6013 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args, arg_idx);
6018 if (arg == error_mark_node)
6020 if (complain & tf_error)
6021 error ("template argument %d is invalid", arg_idx + 1);
6024 /* This only occurs if there was an error in the template
6025 parameter list itself (which we would already have
6026 reported) that we are trying to recover from, e.g., a class
6027 template with a parameter list such as
6028 template<typename..., typename>. */
6029 return error_mark_node;
6031 arg = convert_template_argument (TREE_VALUE (parm),
6032 arg, new_args, complain,
6035 if (arg == error_mark_node)
6037 TREE_VEC_ELT (new_inner_args, arg_idx) = arg;
6039 cp_unevaluated_operand = saved_unevaluated_operand;
6040 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
6043 return error_mark_node;
6045 #ifdef ENABLE_CHECKING
6046 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args))
6047 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args,
6048 TREE_VEC_LENGTH (new_inner_args));
6051 return new_inner_args;
6054 /* Returns 1 if template args OT and NT are equivalent. */
6057 template_args_equal (tree ot, tree nt)
6062 if (TREE_CODE (nt) == TREE_VEC)
6063 /* For member templates */
6064 return TREE_CODE (ot) == TREE_VEC && comp_template_args (ot, nt);
6065 else if (PACK_EXPANSION_P (ot))
6066 return PACK_EXPANSION_P (nt)
6067 && template_args_equal (PACK_EXPANSION_PATTERN (ot),
6068 PACK_EXPANSION_PATTERN (nt));
6069 else if (ARGUMENT_PACK_P (ot))
6074 if (!ARGUMENT_PACK_P (nt))
6077 opack = ARGUMENT_PACK_ARGS (ot);
6078 npack = ARGUMENT_PACK_ARGS (nt);
6079 len = TREE_VEC_LENGTH (opack);
6080 if (TREE_VEC_LENGTH (npack) != len)
6082 for (i = 0; i < len; ++i)
6083 if (!template_args_equal (TREE_VEC_ELT (opack, i),
6084 TREE_VEC_ELT (npack, i)))
6088 else if (ot && TREE_CODE (ot) == ARGUMENT_PACK_SELECT)
6090 /* We get here probably because we are in the middle of substituting
6091 into the pattern of a pack expansion. In that case the
6092 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
6093 interested in. So we want to use the initial pack argument for
6095 ot = ARGUMENT_PACK_SELECT_FROM_PACK (ot);
6096 if (nt && TREE_CODE (nt) == ARGUMENT_PACK_SELECT)
6097 nt = ARGUMENT_PACK_SELECT_FROM_PACK (nt);
6098 return template_args_equal (ot, nt);
6100 else if (TYPE_P (nt))
6101 return TYPE_P (ot) && same_type_p (ot, nt);
6102 else if (TREE_CODE (ot) == TREE_VEC || TYPE_P (ot))
6105 return cp_tree_equal (ot, nt);
6108 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
6109 of template arguments. Returns 0 otherwise. */
6112 comp_template_args (tree oldargs, tree newargs)
6116 if (TREE_VEC_LENGTH (oldargs) != TREE_VEC_LENGTH (newargs))
6119 for (i = 0; i < TREE_VEC_LENGTH (oldargs); ++i)
6121 tree nt = TREE_VEC_ELT (newargs, i);
6122 tree ot = TREE_VEC_ELT (oldargs, i);
6124 if (! template_args_equal (ot, nt))
6131 add_pending_template (tree d)
6133 tree ti = (TYPE_P (d)
6134 ? CLASSTYPE_TEMPLATE_INFO (d)
6135 : DECL_TEMPLATE_INFO (d));
6136 struct pending_template *pt;
6139 if (TI_PENDING_TEMPLATE_FLAG (ti))
6142 /* We are called both from instantiate_decl, where we've already had a
6143 tinst_level pushed, and instantiate_template, where we haven't.
6145 level = !current_tinst_level || current_tinst_level->decl != d;
6148 push_tinst_level (d);
6150 pt = GGC_NEW (struct pending_template);
6152 pt->tinst = current_tinst_level;
6153 if (last_pending_template)
6154 last_pending_template->next = pt;
6156 pending_templates = pt;
6158 last_pending_template = pt;
6160 TI_PENDING_TEMPLATE_FLAG (ti) = 1;
6167 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
6168 ARGLIST. Valid choices for FNS are given in the cp-tree.def
6169 documentation for TEMPLATE_ID_EXPR. */
6172 lookup_template_function (tree fns, tree arglist)
6176 if (fns == error_mark_node || arglist == error_mark_node)
6177 return error_mark_node;
6179 gcc_assert (!arglist || TREE_CODE (arglist) == TREE_VEC);
6180 gcc_assert (fns && (is_overloaded_fn (fns)
6181 || TREE_CODE (fns) == IDENTIFIER_NODE));
6183 if (BASELINK_P (fns))
6185 BASELINK_FUNCTIONS (fns) = build2 (TEMPLATE_ID_EXPR,
6187 BASELINK_FUNCTIONS (fns),
6192 type = TREE_TYPE (fns);
6193 if (TREE_CODE (fns) == OVERLOAD || !type)
6194 type = unknown_type_node;
6196 return build2 (TEMPLATE_ID_EXPR, type, fns, arglist);
6199 /* Within the scope of a template class S<T>, the name S gets bound
6200 (in build_self_reference) to a TYPE_DECL for the class, not a
6201 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
6202 or one of its enclosing classes, and that type is a template,
6203 return the associated TEMPLATE_DECL. Otherwise, the original
6206 Also handle the case when DECL is a TREE_LIST of ambiguous
6207 injected-class-names from different bases. */
6210 maybe_get_template_decl_from_type_decl (tree decl)
6212 if (decl == NULL_TREE)
6215 /* DR 176: A lookup that finds an injected-class-name (10.2
6216 [class.member.lookup]) can result in an ambiguity in certain cases
6217 (for example, if it is found in more than one base class). If all of
6218 the injected-class-names that are found refer to specializations of
6219 the same class template, and if the name is followed by a
6220 template-argument-list, the reference refers to the class template
6221 itself and not a specialization thereof, and is not ambiguous. */
6222 if (TREE_CODE (decl) == TREE_LIST)
6224 tree t, tmpl = NULL_TREE;
6225 for (t = decl; t; t = TREE_CHAIN (t))
6227 tree elt = maybe_get_template_decl_from_type_decl (TREE_VALUE (t));
6230 else if (tmpl != elt)
6233 if (tmpl && t == NULL_TREE)
6239 return (decl != NULL_TREE
6240 && DECL_SELF_REFERENCE_P (decl)
6241 && CLASSTYPE_TEMPLATE_INFO (TREE_TYPE (decl)))
6242 ? CLASSTYPE_TI_TEMPLATE (TREE_TYPE (decl)) : decl;
6245 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
6246 parameters, find the desired type.
6248 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
6250 IN_DECL, if non-NULL, is the template declaration we are trying to
6253 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
6254 the class we are looking up.
6256 Issue error and warning messages under control of COMPLAIN.
6258 If the template class is really a local class in a template
6259 function, then the FUNCTION_CONTEXT is the function in which it is
6262 ??? Note that this function is currently called *twice* for each
6263 template-id: the first time from the parser, while creating the
6264 incomplete type (finish_template_type), and the second type during the
6265 real instantiation (instantiate_template_class). This is surely something
6266 that we want to avoid. It also causes some problems with argument
6267 coercion (see convert_nontype_argument for more information on this). */
6270 lookup_template_class (tree d1,
6275 tsubst_flags_t complain)
6277 tree templ = NULL_TREE, parmlist;
6284 timevar_push (TV_NAME_LOOKUP);
6286 if (TREE_CODE (d1) == IDENTIFIER_NODE)
6288 tree value = innermost_non_namespace_value (d1);
6289 if (value && DECL_TEMPLATE_TEMPLATE_PARM_P (value))
6294 push_decl_namespace (context);
6295 templ = lookup_name (d1);
6296 templ = maybe_get_template_decl_from_type_decl (templ);
6298 pop_decl_namespace ();
6301 context = DECL_CONTEXT (templ);
6303 else if (TREE_CODE (d1) == TYPE_DECL && MAYBE_CLASS_TYPE_P (TREE_TYPE (d1)))
6305 tree type = TREE_TYPE (d1);
6307 /* If we are declaring a constructor, say A<T>::A<T>, we will get
6308 an implicit typename for the second A. Deal with it. */
6309 if (TREE_CODE (type) == TYPENAME_TYPE && TREE_TYPE (type))
6310 type = TREE_TYPE (type);
6312 if (CLASSTYPE_TEMPLATE_INFO (type))
6314 templ = CLASSTYPE_TI_TEMPLATE (type);
6315 d1 = DECL_NAME (templ);
6318 else if (TREE_CODE (d1) == ENUMERAL_TYPE
6319 || (TYPE_P (d1) && MAYBE_CLASS_TYPE_P (d1)))
6321 templ = TYPE_TI_TEMPLATE (d1);
6322 d1 = DECL_NAME (templ);
6324 else if (TREE_CODE (d1) == TEMPLATE_DECL
6325 && DECL_TEMPLATE_RESULT (d1)
6326 && TREE_CODE (DECL_TEMPLATE_RESULT (d1)) == TYPE_DECL)
6329 d1 = DECL_NAME (templ);
6330 context = DECL_CONTEXT (templ);
6333 /* Issue an error message if we didn't find a template. */
6336 if (complain & tf_error)
6337 error ("%qT is not a template", d1);
6338 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6341 if (TREE_CODE (templ) != TEMPLATE_DECL
6342 /* Make sure it's a user visible template, if it was named by
6344 || ((complain & tf_user) && !DECL_TEMPLATE_PARM_P (templ)
6345 && !PRIMARY_TEMPLATE_P (templ)))
6347 if (complain & tf_error)
6349 error ("non-template type %qT used as a template", d1);
6351 error ("for template declaration %q+D", in_decl);
6353 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6356 complain &= ~tf_user;
6358 if (DECL_TEMPLATE_TEMPLATE_PARM_P (templ))
6360 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
6361 template arguments */
6367 parmlist = DECL_INNERMOST_TEMPLATE_PARMS (templ);
6369 /* Consider an example where a template template parameter declared as
6371 template <class T, class U = std::allocator<T> > class TT
6373 The template parameter level of T and U are one level larger than
6374 of TT. To proper process the default argument of U, say when an
6375 instantiation `TT<int>' is seen, we need to build the full
6376 arguments containing {int} as the innermost level. Outer levels,
6377 available when not appearing as default template argument, can be
6378 obtained from the arguments of the enclosing template.
6380 Suppose that TT is later substituted with std::vector. The above
6381 instantiation is `TT<int, std::allocator<T> >' with TT at
6382 level 1, and T at level 2, while the template arguments at level 1
6383 becomes {std::vector} and the inner level 2 is {int}. */
6385 outer = DECL_CONTEXT (templ);
6387 outer = TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (outer)));
6388 else if (current_template_parms)
6389 /* This is an argument of the current template, so we haven't set
6390 DECL_CONTEXT yet. */
6391 outer = current_template_args ();
6394 arglist = add_to_template_args (outer, arglist);
6396 arglist2 = coerce_template_parms (parmlist, arglist, templ,
6398 /*require_all_args=*/true,
6399 /*use_default_args=*/true);
6400 if (arglist2 == error_mark_node
6401 || (!uses_template_parms (arglist2)
6402 && check_instantiated_args (templ, arglist2, complain)))
6403 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6405 parm = bind_template_template_parm (TREE_TYPE (templ), arglist2);
6406 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, parm);
6410 tree template_type = TREE_TYPE (templ);
6413 tree found = NULL_TREE;
6416 int is_dependent_type;
6417 int use_partial_inst_tmpl = false;
6419 gen_tmpl = most_general_template (templ);
6420 parmlist = DECL_TEMPLATE_PARMS (gen_tmpl);
6421 parm_depth = TMPL_PARMS_DEPTH (parmlist);
6422 arg_depth = TMPL_ARGS_DEPTH (arglist);
6424 if (arg_depth == 1 && parm_depth > 1)
6426 /* We've been given an incomplete set of template arguments.
6429 template <class T> struct S1 {
6430 template <class U> struct S2 {};
6431 template <class U> struct S2<U*> {};
6434 we will be called with an ARGLIST of `U*', but the
6435 TEMPLATE will be `template <class T> template
6436 <class U> struct S1<T>::S2'. We must fill in the missing
6439 = add_outermost_template_args (TYPE_TI_ARGS (TREE_TYPE (templ)),
6441 arg_depth = TMPL_ARGS_DEPTH (arglist);
6444 /* Now we should have enough arguments. */
6445 gcc_assert (parm_depth == arg_depth);
6447 /* From here on, we're only interested in the most general
6450 /* Calculate the BOUND_ARGS. These will be the args that are
6451 actually tsubst'd into the definition to create the
6455 /* We have multiple levels of arguments to coerce, at once. */
6457 int saved_depth = TMPL_ARGS_DEPTH (arglist);
6459 tree bound_args = make_tree_vec (parm_depth);
6461 for (i = saved_depth,
6462 t = DECL_TEMPLATE_PARMS (gen_tmpl);
6463 i > 0 && t != NULL_TREE;
6464 --i, t = TREE_CHAIN (t))
6466 tree a = coerce_template_parms (TREE_VALUE (t),
6469 /*require_all_args=*/true,
6470 /*use_default_args=*/true);
6472 /* Don't process further if one of the levels fails. */
6473 if (a == error_mark_node)
6475 /* Restore the ARGLIST to its full size. */
6476 TREE_VEC_LENGTH (arglist) = saved_depth;
6477 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6480 SET_TMPL_ARGS_LEVEL (bound_args, i, a);
6482 /* We temporarily reduce the length of the ARGLIST so
6483 that coerce_template_parms will see only the arguments
6484 corresponding to the template parameters it is
6486 TREE_VEC_LENGTH (arglist)--;
6489 /* Restore the ARGLIST to its full size. */
6490 TREE_VEC_LENGTH (arglist) = saved_depth;
6492 arglist = bound_args;
6496 = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parmlist),
6497 INNERMOST_TEMPLATE_ARGS (arglist),
6500 /*require_all_args=*/true,
6501 /*use_default_args=*/true);
6503 if (arglist == error_mark_node)
6504 /* We were unable to bind the arguments. */
6505 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6507 /* In the scope of a template class, explicit references to the
6508 template class refer to the type of the template, not any
6509 instantiation of it. For example, in:
6511 template <class T> class C { void f(C<T>); }
6513 the `C<T>' is just the same as `C'. Outside of the
6514 class, however, such a reference is an instantiation. */
6516 || !PRIMARY_TEMPLATE_P (gen_tmpl)
6517 || currently_open_class (template_type))
6518 /* comp_template_args is expensive, check it last. */
6519 && comp_template_args (TYPE_TI_ARGS (template_type),
6521 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, template_type);
6523 /* If we already have this specialization, return it. */
6524 elt.tmpl = gen_tmpl;
6526 hash = hash_specialization (&elt);
6527 entry = (spec_entry *) htab_find_with_hash (type_specializations,
6531 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, entry->spec);
6533 is_dependent_type = uses_template_parms (arglist);
6535 /* If the deduced arguments are invalid, then the binding
6537 if (!is_dependent_type
6538 && check_instantiated_args (gen_tmpl,
6539 INNERMOST_TEMPLATE_ARGS (arglist),
6541 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6543 if (!is_dependent_type
6544 && !PRIMARY_TEMPLATE_P (gen_tmpl)
6545 && !LAMBDA_TYPE_P (TREE_TYPE (gen_tmpl))
6546 && TREE_CODE (CP_DECL_CONTEXT (gen_tmpl)) == NAMESPACE_DECL)
6548 found = xref_tag_from_type (TREE_TYPE (gen_tmpl),
6549 DECL_NAME (gen_tmpl),
6550 /*tag_scope=*/ts_global);
6551 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, found);
6554 context = tsubst (DECL_CONTEXT (gen_tmpl), arglist,
6557 context = global_namespace;
6559 /* Create the type. */
6560 if (TREE_CODE (template_type) == ENUMERAL_TYPE)
6562 if (!is_dependent_type)
6564 set_current_access_from_decl (TYPE_NAME (template_type));
6565 t = start_enum (TYPE_IDENTIFIER (template_type),
6566 tsubst (ENUM_UNDERLYING_TYPE (template_type),
6567 arglist, complain, in_decl),
6568 SCOPED_ENUM_P (template_type));
6572 /* We don't want to call start_enum for this type, since
6573 the values for the enumeration constants may involve
6574 template parameters. And, no one should be interested
6575 in the enumeration constants for such a type. */
6576 t = cxx_make_type (ENUMERAL_TYPE);
6577 SET_SCOPED_ENUM_P (t, SCOPED_ENUM_P (template_type));
6582 t = make_class_type (TREE_CODE (template_type));
6583 CLASSTYPE_DECLARED_CLASS (t)
6584 = CLASSTYPE_DECLARED_CLASS (template_type);
6585 SET_CLASSTYPE_IMPLICIT_INSTANTIATION (t);
6586 TYPE_FOR_JAVA (t) = TYPE_FOR_JAVA (template_type);
6588 /* A local class. Make sure the decl gets registered properly. */
6589 if (context == current_function_decl)
6590 pushtag (DECL_NAME (gen_tmpl), t, /*tag_scope=*/ts_current);
6592 if (comp_template_args (CLASSTYPE_TI_ARGS (template_type), arglist))
6593 /* This instantiation is another name for the primary
6594 template type. Set the TYPE_CANONICAL field
6596 TYPE_CANONICAL (t) = template_type;
6597 else if (any_template_arguments_need_structural_equality_p (arglist))
6598 /* Some of the template arguments require structural
6599 equality testing, so this template class requires
6600 structural equality testing. */
6601 SET_TYPE_STRUCTURAL_EQUALITY (t);
6604 /* If we called start_enum or pushtag above, this information
6605 will already be set up. */
6608 TYPE_CONTEXT (t) = FROB_CONTEXT (context);
6610 type_decl = create_implicit_typedef (DECL_NAME (gen_tmpl), t);
6611 DECL_CONTEXT (type_decl) = TYPE_CONTEXT (t);
6612 DECL_SOURCE_LOCATION (type_decl)
6613 = DECL_SOURCE_LOCATION (TYPE_STUB_DECL (template_type));
6616 type_decl = TYPE_NAME (t);
6618 TREE_PRIVATE (type_decl)
6619 = TREE_PRIVATE (TYPE_STUB_DECL (template_type));
6620 TREE_PROTECTED (type_decl)
6621 = TREE_PROTECTED (TYPE_STUB_DECL (template_type));
6622 if (CLASSTYPE_VISIBILITY_SPECIFIED (template_type))
6624 DECL_VISIBILITY_SPECIFIED (type_decl) = 1;
6625 DECL_VISIBILITY (type_decl) = CLASSTYPE_VISIBILITY (template_type);
6628 /* Let's consider the explicit specialization of a member
6629 of a class template specialization that is implicitely instantiated,
6634 template<class U> struct M {}; //#0
6639 struct S<int>::M<char> //#1
6643 [temp.expl.spec]/4 says this is valid.
6645 In this case, when we write:
6648 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
6651 When we encounter #1, we want to store the partial instantiation
6652 of M (template<class T> S<int>::M<T>) in it's CLASSTYPE_TI_TEMPLATE.
6654 For all cases other than this "explicit specialization of member of a
6655 class template", we just want to store the most general template into
6656 the CLASSTYPE_TI_TEMPLATE of M.
6658 This case of "explicit specialization of member of a class template"
6660 1/ the enclosing class is an instantiation of, and therefore not
6661 the same as, the context of the most general template, and
6662 2/ we aren't looking at the partial instantiation itself, i.e.
6663 the innermost arguments are not the same as the innermost parms of
6664 the most general template.
6666 So it's only when 1/ and 2/ happens that we want to use the partial
6667 instantiation of the member template in lieu of its most general
6670 if (PRIMARY_TEMPLATE_P (gen_tmpl)
6671 && TMPL_ARGS_HAVE_MULTIPLE_LEVELS (arglist)
6672 /* the enclosing class must be an instantiation... */
6673 && CLASS_TYPE_P (context)
6674 && !same_type_p (context, DECL_CONTEXT (gen_tmpl)))
6676 tree partial_inst_args;
6677 TREE_VEC_LENGTH (arglist)--;
6678 ++processing_template_decl;
6680 tsubst (INNERMOST_TEMPLATE_ARGS
6681 (CLASSTYPE_TI_ARGS (TREE_TYPE (gen_tmpl))),
6682 arglist, complain, NULL_TREE);
6683 --processing_template_decl;
6684 TREE_VEC_LENGTH (arglist)++;
6685 use_partial_inst_tmpl =
6686 /*...and we must not be looking at the partial instantiation
6688 !comp_template_args (INNERMOST_TEMPLATE_ARGS (arglist),
6692 if (!use_partial_inst_tmpl)
6693 /* This case is easy; there are no member templates involved. */
6697 /* This is a full instantiation of a member template. Find
6698 the partial instantiation of which this is an instance. */
6700 /* Temporarily reduce by one the number of levels in the ARGLIST
6701 so as to avoid comparing the last set of arguments. */
6702 TREE_VEC_LENGTH (arglist)--;
6703 found = tsubst (gen_tmpl, arglist, complain, NULL_TREE);
6704 TREE_VEC_LENGTH (arglist)++;
6705 found = CLASSTYPE_TI_TEMPLATE (found);
6708 SET_TYPE_TEMPLATE_INFO (t, build_template_info (found, arglist));
6711 slot = (spec_entry **) htab_find_slot_with_hash (type_specializations,
6712 &elt, hash, INSERT);
6713 *slot = GGC_NEW (spec_entry);
6716 /* Note this use of the partial instantiation so we can check it
6717 later in maybe_process_partial_specialization. */
6718 DECL_TEMPLATE_INSTANTIATIONS (templ)
6719 = tree_cons (arglist, t,
6720 DECL_TEMPLATE_INSTANTIATIONS (templ));
6722 if (TREE_CODE (t) == ENUMERAL_TYPE && !is_dependent_type)
6723 /* Now that the type has been registered on the instantiations
6724 list, we set up the enumerators. Because the enumeration
6725 constants may involve the enumeration type itself, we make
6726 sure to register the type first, and then create the
6727 constants. That way, doing tsubst_expr for the enumeration
6728 constants won't result in recursive calls here; we'll find
6729 the instantiation and exit above. */
6730 tsubst_enum (template_type, t, arglist);
6732 if (is_dependent_type)
6733 /* If the type makes use of template parameters, the
6734 code that generates debugging information will crash. */
6735 DECL_IGNORED_P (TYPE_STUB_DECL (t)) = 1;
6737 /* Possibly limit visibility based on template args. */
6738 TREE_PUBLIC (type_decl) = 1;
6739 determine_visibility (type_decl);
6741 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, t);
6743 timevar_pop (TV_NAME_LOOKUP);
6750 /* True when we should also visit template parameters that occur in
6751 non-deduced contexts. */
6752 bool include_nondeduced_p;
6753 struct pointer_set_t *visited;
6756 /* Called from for_each_template_parm via walk_tree. */
6759 for_each_template_parm_r (tree *tp, int *walk_subtrees, void *d)
6762 struct pair_fn_data *pfd = (struct pair_fn_data *) d;
6763 tree_fn_t fn = pfd->fn;
6764 void *data = pfd->data;
6767 && (pfd->include_nondeduced_p || TREE_CODE (t) != TYPENAME_TYPE)
6768 && for_each_template_parm (TYPE_CONTEXT (t), fn, data, pfd->visited,
6769 pfd->include_nondeduced_p))
6770 return error_mark_node;
6772 switch (TREE_CODE (t))
6775 if (TYPE_PTRMEMFUNC_P (t))
6781 if (!TYPE_TEMPLATE_INFO (t))
6783 else if (for_each_template_parm (TI_ARGS (TYPE_TEMPLATE_INFO (t)),
6784 fn, data, pfd->visited,
6785 pfd->include_nondeduced_p))
6786 return error_mark_node;
6790 if (for_each_template_parm (TYPE_MIN_VALUE (t),
6791 fn, data, pfd->visited,
6792 pfd->include_nondeduced_p)
6793 || for_each_template_parm (TYPE_MAX_VALUE (t),
6794 fn, data, pfd->visited,
6795 pfd->include_nondeduced_p))
6796 return error_mark_node;
6800 /* Since we're not going to walk subtrees, we have to do this
6802 if (for_each_template_parm (TYPE_METHOD_BASETYPE (t), fn, data,
6803 pfd->visited, pfd->include_nondeduced_p))
6804 return error_mark_node;
6808 /* Check the return type. */
6809 if (for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
6810 pfd->include_nondeduced_p))
6811 return error_mark_node;
6813 /* Check the parameter types. Since default arguments are not
6814 instantiated until they are needed, the TYPE_ARG_TYPES may
6815 contain expressions that involve template parameters. But,
6816 no-one should be looking at them yet. And, once they're
6817 instantiated, they don't contain template parameters, so
6818 there's no point in looking at them then, either. */
6822 for (parm = TYPE_ARG_TYPES (t); parm; parm = TREE_CHAIN (parm))
6823 if (for_each_template_parm (TREE_VALUE (parm), fn, data,
6824 pfd->visited, pfd->include_nondeduced_p))
6825 return error_mark_node;
6827 /* Since we've already handled the TYPE_ARG_TYPES, we don't
6828 want walk_tree walking into them itself. */
6834 if (pfd->include_nondeduced_p
6835 && for_each_template_parm (TYPE_FIELDS (t), fn, data,
6837 pfd->include_nondeduced_p))
6838 return error_mark_node;
6843 if (DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t)
6844 && for_each_template_parm (DECL_TI_ARGS (t), fn, data,
6845 pfd->visited, pfd->include_nondeduced_p))
6846 return error_mark_node;
6851 if (TREE_CODE (t) == CONST_DECL && DECL_TEMPLATE_PARM_P (t)
6852 && for_each_template_parm (DECL_INITIAL (t), fn, data,
6853 pfd->visited, pfd->include_nondeduced_p))
6854 return error_mark_node;
6855 if (DECL_CONTEXT (t)
6856 && pfd->include_nondeduced_p
6857 && for_each_template_parm (DECL_CONTEXT (t), fn, data,
6858 pfd->visited, pfd->include_nondeduced_p))
6859 return error_mark_node;
6862 case BOUND_TEMPLATE_TEMPLATE_PARM:
6863 /* Record template parameters such as `T' inside `TT<T>'. */
6864 if (for_each_template_parm (TYPE_TI_ARGS (t), fn, data, pfd->visited,
6865 pfd->include_nondeduced_p))
6866 return error_mark_node;
6869 case TEMPLATE_TEMPLATE_PARM:
6870 case TEMPLATE_TYPE_PARM:
6871 case TEMPLATE_PARM_INDEX:
6872 if (fn && (*fn)(t, data))
6873 return error_mark_node;
6875 return error_mark_node;
6879 /* A template template parameter is encountered. */
6880 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t)
6881 && for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
6882 pfd->include_nondeduced_p))
6883 return error_mark_node;
6885 /* Already substituted template template parameter */
6891 || for_each_template_parm (TYPENAME_TYPE_FULLNAME (t), fn,
6893 pfd->include_nondeduced_p))
6894 return error_mark_node;
6898 if (TREE_TYPE (t) && TYPE_PTRMEMFUNC_P (TREE_TYPE (t))
6899 && pfd->include_nondeduced_p
6900 && for_each_template_parm (TYPE_PTRMEMFUNC_FN_TYPE
6901 (TREE_TYPE (t)), fn, data,
6902 pfd->visited, pfd->include_nondeduced_p))
6903 return error_mark_node;
6908 /* If there's no type, then this thing must be some expression
6909 involving template parameters. */
6910 if (!fn && !TREE_TYPE (t))
6911 return error_mark_node;
6916 case REINTERPRET_CAST_EXPR:
6917 case CONST_CAST_EXPR:
6918 case STATIC_CAST_EXPR:
6919 case DYNAMIC_CAST_EXPR:
6923 case PSEUDO_DTOR_EXPR:
6925 return error_mark_node;
6932 /* We didn't find any template parameters we liked. */
6936 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
6937 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
6938 call FN with the parameter and the DATA.
6939 If FN returns nonzero, the iteration is terminated, and
6940 for_each_template_parm returns 1. Otherwise, the iteration
6941 continues. If FN never returns a nonzero value, the value
6942 returned by for_each_template_parm is 0. If FN is NULL, it is
6943 considered to be the function which always returns 1.
6945 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
6946 parameters that occur in non-deduced contexts. When false, only
6947 visits those template parameters that can be deduced. */
6950 for_each_template_parm (tree t, tree_fn_t fn, void* data,
6951 struct pointer_set_t *visited,
6952 bool include_nondeduced_p)
6954 struct pair_fn_data pfd;
6960 pfd.include_nondeduced_p = include_nondeduced_p;
6962 /* Walk the tree. (Conceptually, we would like to walk without
6963 duplicates, but for_each_template_parm_r recursively calls
6964 for_each_template_parm, so we would need to reorganize a fair
6965 bit to use walk_tree_without_duplicates, so we keep our own
6968 pfd.visited = visited;
6970 pfd.visited = pointer_set_create ();
6971 result = cp_walk_tree (&t,
6972 for_each_template_parm_r,
6974 pfd.visited) != NULL_TREE;
6979 pointer_set_destroy (pfd.visited);
6986 /* Returns true if T depends on any template parameter. */
6989 uses_template_parms (tree t)
6992 int saved_processing_template_decl;
6994 saved_processing_template_decl = processing_template_decl;
6995 if (!saved_processing_template_decl)
6996 processing_template_decl = 1;
6998 dependent_p = dependent_type_p (t);
6999 else if (TREE_CODE (t) == TREE_VEC)
7000 dependent_p = any_dependent_template_arguments_p (t);
7001 else if (TREE_CODE (t) == TREE_LIST)
7002 dependent_p = (uses_template_parms (TREE_VALUE (t))
7003 || uses_template_parms (TREE_CHAIN (t)));
7004 else if (TREE_CODE (t) == TYPE_DECL)
7005 dependent_p = dependent_type_p (TREE_TYPE (t));
7008 || TREE_CODE (t) == TEMPLATE_PARM_INDEX
7009 || TREE_CODE (t) == OVERLOAD
7010 || TREE_CODE (t) == BASELINK
7011 || TREE_CODE (t) == IDENTIFIER_NODE
7012 || TREE_CODE (t) == TRAIT_EXPR
7013 || TREE_CODE (t) == CONSTRUCTOR
7014 || CONSTANT_CLASS_P (t))
7015 dependent_p = (type_dependent_expression_p (t)
7016 || value_dependent_expression_p (t));
7019 gcc_assert (t == error_mark_node);
7020 dependent_p = false;
7023 processing_template_decl = saved_processing_template_decl;
7028 /* Returns true if T depends on any template parameter with level LEVEL. */
7031 uses_template_parms_level (tree t, int level)
7033 return for_each_template_parm (t, template_parm_this_level_p, &level, NULL,
7034 /*include_nondeduced_p=*/true);
7037 static int tinst_depth;
7038 extern int max_tinst_depth;
7039 #ifdef GATHER_STATISTICS
7042 static int tinst_level_tick;
7043 static int last_template_error_tick;
7045 /* We're starting to instantiate D; record the template instantiation context
7046 for diagnostics and to restore it later. */
7049 push_tinst_level (tree d)
7051 struct tinst_level *new_level;
7053 if (tinst_depth >= max_tinst_depth)
7055 /* If the instantiation in question still has unbound template parms,
7056 we don't really care if we can't instantiate it, so just return.
7057 This happens with base instantiation for implicit `typename'. */
7058 if (uses_template_parms (d))
7061 last_template_error_tick = tinst_level_tick;
7062 error ("template instantiation depth exceeds maximum of %d (use "
7063 "-ftemplate-depth= to increase the maximum) instantiating %qD",
7064 max_tinst_depth, d);
7066 print_instantiation_context ();
7071 new_level = GGC_NEW (struct tinst_level);
7072 new_level->decl = d;
7073 new_level->locus = input_location;
7074 new_level->in_system_header_p = in_system_header;
7075 new_level->next = current_tinst_level;
7076 current_tinst_level = new_level;
7079 #ifdef GATHER_STATISTICS
7080 if (tinst_depth > depth_reached)
7081 depth_reached = tinst_depth;
7088 /* We're done instantiating this template; return to the instantiation
7092 pop_tinst_level (void)
7094 /* Restore the filename and line number stashed away when we started
7095 this instantiation. */
7096 input_location = current_tinst_level->locus;
7097 current_tinst_level = current_tinst_level->next;
7102 /* We're instantiating a deferred template; restore the template
7103 instantiation context in which the instantiation was requested, which
7104 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
7107 reopen_tinst_level (struct tinst_level *level)
7109 struct tinst_level *t;
7112 for (t = level; t; t = t->next)
7115 current_tinst_level = level;
7120 /* Returns the TINST_LEVEL which gives the original instantiation
7123 struct tinst_level *
7124 outermost_tinst_level (void)
7126 struct tinst_level *level = current_tinst_level;
7129 level = level->next;
7133 /* Returns TRUE if PARM is a parameter of the template TEMPL. */
7136 parameter_of_template_p (tree parm, tree templ)
7141 if (!parm || !templ)
7144 gcc_assert (DECL_TEMPLATE_PARM_P (parm));
7145 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
7147 parms = DECL_TEMPLATE_PARMS (templ);
7148 parms = INNERMOST_TEMPLATE_PARMS (parms);
7150 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
7151 if (parm == TREE_VALUE (TREE_VEC_ELT (parms, i)))
7157 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
7158 vector of template arguments, as for tsubst.
7160 Returns an appropriate tsubst'd friend declaration. */
7163 tsubst_friend_function (tree decl, tree args)
7167 if (TREE_CODE (decl) == FUNCTION_DECL
7168 && DECL_TEMPLATE_INSTANTIATION (decl)
7169 && TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
7170 /* This was a friend declared with an explicit template
7171 argument list, e.g.:
7175 to indicate that f was a template instantiation, not a new
7176 function declaration. Now, we have to figure out what
7177 instantiation of what template. */
7179 tree template_id, arglist, fns;
7182 tree ns = decl_namespace_context (TYPE_MAIN_DECL (current_class_type));
7184 /* Friend functions are looked up in the containing namespace scope.
7185 We must enter that scope, to avoid finding member functions of the
7186 current class with same name. */
7187 push_nested_namespace (ns);
7188 fns = tsubst_expr (DECL_TI_TEMPLATE (decl), args,
7189 tf_warning_or_error, NULL_TREE,
7190 /*integral_constant_expression_p=*/false);
7191 pop_nested_namespace (ns);
7192 arglist = tsubst (DECL_TI_ARGS (decl), args,
7193 tf_warning_or_error, NULL_TREE);
7194 template_id = lookup_template_function (fns, arglist);
7196 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
7197 tmpl = determine_specialization (template_id, new_friend,
7199 /*need_member_template=*/0,
7200 TREE_VEC_LENGTH (args),
7202 return instantiate_template (tmpl, new_args, tf_error);
7205 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
7207 /* The NEW_FRIEND will look like an instantiation, to the
7208 compiler, but is not an instantiation from the point of view of
7209 the language. For example, we might have had:
7211 template <class T> struct S {
7212 template <class U> friend void f(T, U);
7215 Then, in S<int>, template <class U> void f(int, U) is not an
7216 instantiation of anything. */
7217 if (new_friend == error_mark_node)
7218 return error_mark_node;
7220 DECL_USE_TEMPLATE (new_friend) = 0;
7221 if (TREE_CODE (decl) == TEMPLATE_DECL)
7223 DECL_USE_TEMPLATE (DECL_TEMPLATE_RESULT (new_friend)) = 0;
7224 DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (new_friend))
7225 = DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (decl));
7228 /* The mangled name for the NEW_FRIEND is incorrect. The function
7229 is not a template instantiation and should not be mangled like
7230 one. Therefore, we forget the mangling here; we'll recompute it
7231 later if we need it. */
7232 if (TREE_CODE (new_friend) != TEMPLATE_DECL)
7234 SET_DECL_RTL (new_friend, NULL_RTX);
7235 SET_DECL_ASSEMBLER_NAME (new_friend, NULL_TREE);
7238 if (DECL_NAMESPACE_SCOPE_P (new_friend))
7241 tree new_friend_template_info;
7242 tree new_friend_result_template_info;
7244 int new_friend_is_defn;
7246 /* We must save some information from NEW_FRIEND before calling
7247 duplicate decls since that function will free NEW_FRIEND if
7249 new_friend_template_info = DECL_TEMPLATE_INFO (new_friend);
7250 new_friend_is_defn =
7251 (DECL_INITIAL (DECL_TEMPLATE_RESULT
7252 (template_for_substitution (new_friend)))
7254 if (TREE_CODE (new_friend) == TEMPLATE_DECL)
7256 /* This declaration is a `primary' template. */
7257 DECL_PRIMARY_TEMPLATE (new_friend) = new_friend;
7259 new_friend_result_template_info
7260 = DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (new_friend));
7263 new_friend_result_template_info = NULL_TREE;
7265 /* Make the init_value nonzero so pushdecl knows this is a defn. */
7266 if (new_friend_is_defn)
7267 DECL_INITIAL (new_friend) = error_mark_node;
7269 /* Inside pushdecl_namespace_level, we will push into the
7270 current namespace. However, the friend function should go
7271 into the namespace of the template. */
7272 ns = decl_namespace_context (new_friend);
7273 push_nested_namespace (ns);
7274 old_decl = pushdecl_namespace_level (new_friend, /*is_friend=*/true);
7275 pop_nested_namespace (ns);
7277 if (old_decl == error_mark_node)
7278 return error_mark_node;
7280 if (old_decl != new_friend)
7282 /* This new friend declaration matched an existing
7283 declaration. For example, given:
7285 template <class T> void f(T);
7286 template <class U> class C {
7287 template <class T> friend void f(T) {}
7290 the friend declaration actually provides the definition
7291 of `f', once C has been instantiated for some type. So,
7292 old_decl will be the out-of-class template declaration,
7293 while new_friend is the in-class definition.
7295 But, if `f' was called before this point, the
7296 instantiation of `f' will have DECL_TI_ARGS corresponding
7297 to `T' but not to `U', references to which might appear
7298 in the definition of `f'. Previously, the most general
7299 template for an instantiation of `f' was the out-of-class
7300 version; now it is the in-class version. Therefore, we
7301 run through all specialization of `f', adding to their
7302 DECL_TI_ARGS appropriately. In particular, they need a
7303 new set of outer arguments, corresponding to the
7304 arguments for this class instantiation.
7306 The same situation can arise with something like this:
7309 template <class T> class C {
7313 when `C<int>' is instantiated. Now, `f(int)' is defined
7316 if (!new_friend_is_defn)
7317 /* On the other hand, if the in-class declaration does
7318 *not* provide a definition, then we don't want to alter
7319 existing definitions. We can just leave everything
7324 tree new_template = TI_TEMPLATE (new_friend_template_info);
7325 tree new_args = TI_ARGS (new_friend_template_info);
7327 /* Overwrite whatever template info was there before, if
7328 any, with the new template information pertaining to
7330 DECL_TEMPLATE_INFO (old_decl) = new_friend_template_info;
7332 if (TREE_CODE (old_decl) != TEMPLATE_DECL)
7334 /* We should have called reregister_specialization in
7336 gcc_assert (retrieve_specialization (new_template,
7340 /* Instantiate it if the global has already been used. */
7341 if (DECL_ODR_USED (old_decl))
7342 instantiate_decl (old_decl, /*defer_ok=*/true,
7343 /*expl_inst_class_mem_p=*/false);
7349 /* Indicate that the old function template is a partial
7351 DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (old_decl))
7352 = new_friend_result_template_info;
7354 gcc_assert (new_template
7355 == most_general_template (new_template));
7356 gcc_assert (new_template != old_decl);
7358 /* Reassign any specializations already in the hash table
7359 to the new more general template, and add the
7360 additional template args. */
7361 for (t = DECL_TEMPLATE_INSTANTIATIONS (old_decl);
7365 tree spec = TREE_VALUE (t);
7368 elt.tmpl = old_decl;
7369 elt.args = DECL_TI_ARGS (spec);
7370 elt.spec = NULL_TREE;
7372 htab_remove_elt (decl_specializations, &elt);
7375 = add_outermost_template_args (new_args,
7376 DECL_TI_ARGS (spec));
7378 register_specialization
7379 (spec, new_template, DECL_TI_ARGS (spec), true, 0);
7382 DECL_TEMPLATE_INSTANTIATIONS (old_decl) = NULL_TREE;
7386 /* The information from NEW_FRIEND has been merged into OLD_DECL
7387 by duplicate_decls. */
7388 new_friend = old_decl;
7393 tree context = DECL_CONTEXT (new_friend);
7397 template <class T> class C {
7398 template <class U> friend void C1<U>::f (); // case 1
7399 friend void C2<T>::f (); // case 2
7401 we only need to make sure CONTEXT is a complete type for
7402 case 2. To distinguish between the two cases, we note that
7403 CONTEXT of case 1 remains dependent type after tsubst while
7404 this isn't true for case 2. */
7405 ++processing_template_decl;
7406 dependent_p = dependent_type_p (context);
7407 --processing_template_decl;
7410 && !complete_type_or_else (context, NULL_TREE))
7411 return error_mark_node;
7413 if (COMPLETE_TYPE_P (context))
7415 /* Check to see that the declaration is really present, and,
7416 possibly obtain an improved declaration. */
7417 tree fn = check_classfn (context,
7418 new_friend, NULL_TREE);
7428 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
7429 template arguments, as for tsubst.
7431 Returns an appropriate tsubst'd friend type or error_mark_node on
7435 tsubst_friend_class (tree friend_tmpl, tree args)
7441 context = DECL_CONTEXT (friend_tmpl);
7445 if (TREE_CODE (context) == NAMESPACE_DECL)
7446 push_nested_namespace (context);
7448 push_nested_class (tsubst (context, args, tf_none, NULL_TREE));
7451 /* Look for a class template declaration. We look for hidden names
7452 because two friend declarations of the same template are the
7453 same. For example, in:
7456 template <typename> friend class F;
7458 template <typename> struct B {
7459 template <typename> friend class F;
7462 both F templates are the same. */
7463 tmpl = lookup_name_real (DECL_NAME (friend_tmpl), 0, 0,
7464 /*block_p=*/true, 0,
7465 LOOKUP_COMPLAIN | LOOKUP_HIDDEN);
7467 /* But, if we don't find one, it might be because we're in a
7468 situation like this:
7476 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
7477 for `S<int>', not the TEMPLATE_DECL. */
7478 if (!tmpl || !DECL_CLASS_TEMPLATE_P (tmpl))
7480 tmpl = lookup_name_prefer_type (DECL_NAME (friend_tmpl), 1);
7481 tmpl = maybe_get_template_decl_from_type_decl (tmpl);
7484 if (tmpl && DECL_CLASS_TEMPLATE_P (tmpl))
7486 /* The friend template has already been declared. Just
7487 check to see that the declarations match, and install any new
7488 default parameters. We must tsubst the default parameters,
7489 of course. We only need the innermost template parameters
7490 because that is all that redeclare_class_template will look
7492 if (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (friend_tmpl))
7493 > TMPL_ARGS_DEPTH (args))
7496 location_t saved_input_location;
7497 parms = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_tmpl),
7498 args, tf_warning_or_error);
7500 saved_input_location = input_location;
7501 input_location = DECL_SOURCE_LOCATION (friend_tmpl);
7502 redeclare_class_template (TREE_TYPE (tmpl), parms);
7503 input_location = saved_input_location;
7507 friend_type = TREE_TYPE (tmpl);
7511 /* The friend template has not already been declared. In this
7512 case, the instantiation of the template class will cause the
7513 injection of this template into the global scope. */
7514 tmpl = tsubst (friend_tmpl, args, tf_warning_or_error, NULL_TREE);
7515 if (tmpl == error_mark_node)
7516 return error_mark_node;
7518 /* The new TMPL is not an instantiation of anything, so we
7519 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
7520 the new type because that is supposed to be the corresponding
7521 template decl, i.e., TMPL. */
7522 DECL_USE_TEMPLATE (tmpl) = 0;
7523 DECL_TEMPLATE_INFO (tmpl) = NULL_TREE;
7524 CLASSTYPE_USE_TEMPLATE (TREE_TYPE (tmpl)) = 0;
7525 CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl))
7526 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl)));
7528 /* Inject this template into the global scope. */
7529 friend_type = TREE_TYPE (pushdecl_top_level_maybe_friend (tmpl, true));
7534 if (TREE_CODE (context) == NAMESPACE_DECL)
7535 pop_nested_namespace (context);
7537 pop_nested_class ();
7543 /* Returns zero if TYPE cannot be completed later due to circularity.
7544 Otherwise returns one. */
7547 can_complete_type_without_circularity (tree type)
7549 if (type == NULL_TREE || type == error_mark_node)
7551 else if (COMPLETE_TYPE_P (type))
7553 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
7554 return can_complete_type_without_circularity (TREE_TYPE (type));
7555 else if (CLASS_TYPE_P (type)
7556 && TYPE_BEING_DEFINED (TYPE_MAIN_VARIANT (type)))
7562 /* Apply any attributes which had to be deferred until instantiation
7563 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
7564 ARGS, COMPLAIN, IN_DECL are as tsubst. */
7567 apply_late_template_attributes (tree *decl_p, tree attributes, int attr_flags,
7568 tree args, tsubst_flags_t complain, tree in_decl)
7570 tree last_dep = NULL_TREE;
7574 for (t = attributes; t; t = TREE_CHAIN (t))
7575 if (ATTR_IS_DEPENDENT (t))
7578 attributes = copy_list (attributes);
7582 if (DECL_P (*decl_p))
7584 if (TREE_TYPE (*decl_p) == error_mark_node)
7586 p = &DECL_ATTRIBUTES (*decl_p);
7589 p = &TYPE_ATTRIBUTES (*decl_p);
7593 tree late_attrs = NULL_TREE;
7594 tree *q = &late_attrs;
7596 for (*p = attributes; *p; )
7599 if (ATTR_IS_DEPENDENT (t))
7601 *p = TREE_CHAIN (t);
7602 TREE_CHAIN (t) = NULL_TREE;
7603 /* If the first attribute argument is an identifier, don't
7604 pass it through tsubst. Attributes like mode, format,
7605 cleanup and several target specific attributes expect it
7608 && TREE_CODE (TREE_VALUE (t)) == TREE_LIST
7609 && TREE_VALUE (TREE_VALUE (t))
7610 && (TREE_CODE (TREE_VALUE (TREE_VALUE (t)))
7611 == IDENTIFIER_NODE))
7614 = tsubst_expr (TREE_CHAIN (TREE_VALUE (t)), args, complain,
7616 /*integral_constant_expression_p=*/false);
7617 if (chain != TREE_CHAIN (TREE_VALUE (t)))
7619 = tree_cons (NULL_TREE, TREE_VALUE (TREE_VALUE (t)),
7624 = tsubst_expr (TREE_VALUE (t), args, complain, in_decl,
7625 /*integral_constant_expression_p=*/false);
7627 q = &TREE_CHAIN (t);
7630 p = &TREE_CHAIN (t);
7633 cplus_decl_attributes (decl_p, late_attrs, attr_flags);
7637 /* Perform (or defer) access check for typedefs that were referenced
7638 from within the template TMPL code.
7639 This is a subroutine of instantiate_template and instantiate_class_template.
7640 TMPL is the template to consider and TARGS is the list of arguments of
7644 perform_typedefs_access_check (tree tmpl, tree targs)
7646 location_t saved_location;
7648 qualified_typedef_usage_t *iter;
7651 || (!CLASS_TYPE_P (tmpl)
7652 && TREE_CODE (tmpl) != FUNCTION_DECL))
7655 saved_location = input_location;
7657 VEC_iterate (qualified_typedef_usage_t,
7658 get_types_needing_access_check (tmpl),
7662 tree type_decl = iter->typedef_decl;
7663 tree type_scope = iter->context;
7665 if (!type_decl || !type_scope || !CLASS_TYPE_P (type_scope))
7668 if (uses_template_parms (type_decl))
7669 type_decl = tsubst (type_decl, targs, tf_error, NULL_TREE);
7670 if (uses_template_parms (type_scope))
7671 type_scope = tsubst (type_scope, targs, tf_error, NULL_TREE);
7673 /* Make access check error messages point to the location
7674 of the use of the typedef. */
7675 input_location = iter->locus;
7676 perform_or_defer_access_check (TYPE_BINFO (type_scope),
7677 type_decl, type_decl);
7679 input_location = saved_location;
7683 instantiate_class_template (tree type)
7685 tree templ, args, pattern, t, member;
7689 unsigned int saved_maximum_field_alignment;
7691 if (type == error_mark_node)
7692 return error_mark_node;
7694 if (TYPE_BEING_DEFINED (type)
7695 || COMPLETE_TYPE_P (type)
7696 || uses_template_parms (type))
7699 /* Figure out which template is being instantiated. */
7700 templ = most_general_template (CLASSTYPE_TI_TEMPLATE (type));
7701 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
7703 /* Determine what specialization of the original template to
7705 t = most_specialized_class (type, templ);
7706 if (t == error_mark_node)
7708 TYPE_BEING_DEFINED (type) = 1;
7709 return error_mark_node;
7713 /* This TYPE is actually an instantiation of a partial
7714 specialization. We replace the innermost set of ARGS with
7715 the arguments appropriate for substitution. For example,
7718 template <class T> struct S {};
7719 template <class T> struct S<T*> {};
7721 and supposing that we are instantiating S<int*>, ARGS will
7722 presently be {int*} -- but we need {int}. */
7723 pattern = TREE_TYPE (t);
7724 args = TREE_PURPOSE (t);
7728 pattern = TREE_TYPE (templ);
7729 args = CLASSTYPE_TI_ARGS (type);
7732 /* If the template we're instantiating is incomplete, then clearly
7733 there's nothing we can do. */
7734 if (!COMPLETE_TYPE_P (pattern))
7737 /* If we've recursively instantiated too many templates, stop. */
7738 if (! push_tinst_level (type))
7741 /* Now we're really doing the instantiation. Mark the type as in
7742 the process of being defined. */
7743 TYPE_BEING_DEFINED (type) = 1;
7745 /* We may be in the middle of deferred access check. Disable
7747 push_deferring_access_checks (dk_no_deferred);
7749 push_to_top_level ();
7750 /* Use #pragma pack from the template context. */
7751 saved_maximum_field_alignment = maximum_field_alignment;
7752 maximum_field_alignment = TYPE_PRECISION (pattern);
7754 SET_CLASSTYPE_INTERFACE_UNKNOWN (type);
7756 /* Set the input location to the most specialized template definition.
7757 This is needed if tsubsting causes an error. */
7758 typedecl = TYPE_MAIN_DECL (pattern);
7759 input_location = DECL_SOURCE_LOCATION (typedecl);
7761 TYPE_HAS_USER_CONSTRUCTOR (type) = TYPE_HAS_USER_CONSTRUCTOR (pattern);
7762 TYPE_HAS_NEW_OPERATOR (type) = TYPE_HAS_NEW_OPERATOR (pattern);
7763 TYPE_HAS_ARRAY_NEW_OPERATOR (type) = TYPE_HAS_ARRAY_NEW_OPERATOR (pattern);
7764 TYPE_GETS_DELETE (type) = TYPE_GETS_DELETE (pattern);
7765 TYPE_HAS_ASSIGN_REF (type) = TYPE_HAS_ASSIGN_REF (pattern);
7766 TYPE_HAS_CONST_ASSIGN_REF (type) = TYPE_HAS_CONST_ASSIGN_REF (pattern);
7767 TYPE_HAS_INIT_REF (type) = TYPE_HAS_INIT_REF (pattern);
7768 TYPE_HAS_CONST_INIT_REF (type) = TYPE_HAS_CONST_INIT_REF (pattern);
7769 TYPE_HAS_DEFAULT_CONSTRUCTOR (type) = TYPE_HAS_DEFAULT_CONSTRUCTOR (pattern);
7770 TYPE_HAS_CONVERSION (type) = TYPE_HAS_CONVERSION (pattern);
7771 TYPE_PACKED (type) = TYPE_PACKED (pattern);
7772 TYPE_ALIGN (type) = TYPE_ALIGN (pattern);
7773 TYPE_USER_ALIGN (type) = TYPE_USER_ALIGN (pattern);
7774 TYPE_FOR_JAVA (type) = TYPE_FOR_JAVA (pattern); /* For libjava's JArray<T> */
7775 if (ANON_AGGR_TYPE_P (pattern))
7776 SET_ANON_AGGR_TYPE_P (type);
7777 if (CLASSTYPE_VISIBILITY_SPECIFIED (pattern))
7779 CLASSTYPE_VISIBILITY_SPECIFIED (type) = 1;
7780 CLASSTYPE_VISIBILITY (type) = CLASSTYPE_VISIBILITY (pattern);
7783 pbinfo = TYPE_BINFO (pattern);
7785 /* We should never instantiate a nested class before its enclosing
7786 class; we need to look up the nested class by name before we can
7787 instantiate it, and that lookup should instantiate the enclosing
7789 gcc_assert (!DECL_CLASS_SCOPE_P (TYPE_MAIN_DECL (pattern))
7790 || COMPLETE_TYPE_P (TYPE_CONTEXT (type))
7791 || TYPE_BEING_DEFINED (TYPE_CONTEXT (type)));
7793 base_list = NULL_TREE;
7794 if (BINFO_N_BASE_BINFOS (pbinfo))
7797 tree context = TYPE_CONTEXT (type);
7801 /* We must enter the scope containing the type, as that is where
7802 the accessibility of types named in dependent bases are
7804 pushed_scope = push_scope (context ? context : global_namespace);
7806 /* Substitute into each of the bases to determine the actual
7808 for (i = 0; BINFO_BASE_ITERATE (pbinfo, i, pbase_binfo); i++)
7811 tree access = BINFO_BASE_ACCESS (pbinfo, i);
7812 tree expanded_bases = NULL_TREE;
7815 if (PACK_EXPANSION_P (BINFO_TYPE (pbase_binfo)))
7818 tsubst_pack_expansion (BINFO_TYPE (pbase_binfo),
7819 args, tf_error, NULL_TREE);
7820 if (expanded_bases == error_mark_node)
7823 len = TREE_VEC_LENGTH (expanded_bases);
7826 for (idx = 0; idx < len; idx++)
7829 /* Extract the already-expanded base class. */
7830 base = TREE_VEC_ELT (expanded_bases, idx);
7832 /* Substitute to figure out the base class. */
7833 base = tsubst (BINFO_TYPE (pbase_binfo), args, tf_error,
7836 if (base == error_mark_node)
7839 base_list = tree_cons (access, base, base_list);
7840 if (BINFO_VIRTUAL_P (pbase_binfo))
7841 TREE_TYPE (base_list) = integer_type_node;
7845 /* The list is now in reverse order; correct that. */
7846 base_list = nreverse (base_list);
7849 pop_scope (pushed_scope);
7851 /* Now call xref_basetypes to set up all the base-class
7853 xref_basetypes (type, base_list);
7855 apply_late_template_attributes (&type, TYPE_ATTRIBUTES (pattern),
7856 (int) ATTR_FLAG_TYPE_IN_PLACE,
7857 args, tf_error, NULL_TREE);
7859 /* Now that our base classes are set up, enter the scope of the
7860 class, so that name lookups into base classes, etc. will work
7861 correctly. This is precisely analogous to what we do in
7862 begin_class_definition when defining an ordinary non-template
7863 class, except we also need to push the enclosing classes. */
7864 push_nested_class (type);
7866 /* Now members are processed in the order of declaration. */
7867 for (member = CLASSTYPE_DECL_LIST (pattern);
7868 member; member = TREE_CHAIN (member))
7870 tree t = TREE_VALUE (member);
7872 if (TREE_PURPOSE (member))
7876 /* Build new CLASSTYPE_NESTED_UTDS. */
7879 bool class_template_p;
7881 class_template_p = (TREE_CODE (t) != ENUMERAL_TYPE
7882 && TYPE_LANG_SPECIFIC (t)
7883 && CLASSTYPE_IS_TEMPLATE (t));
7884 /* If the member is a class template, then -- even after
7885 substitution -- there may be dependent types in the
7886 template argument list for the class. We increment
7887 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
7888 that function will assume that no types are dependent
7889 when outside of a template. */
7890 if (class_template_p)
7891 ++processing_template_decl;
7892 newtag = tsubst (t, args, tf_error, NULL_TREE);
7893 if (class_template_p)
7894 --processing_template_decl;
7895 if (newtag == error_mark_node)
7898 if (TREE_CODE (newtag) != ENUMERAL_TYPE)
7900 tree name = TYPE_IDENTIFIER (t);
7902 if (class_template_p)
7903 /* Unfortunately, lookup_template_class sets
7904 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
7905 instantiation (i.e., for the type of a member
7906 template class nested within a template class.)
7907 This behavior is required for
7908 maybe_process_partial_specialization to work
7909 correctly, but is not accurate in this case;
7910 the TAG is not an instantiation of anything.
7911 (The corresponding TEMPLATE_DECL is an
7912 instantiation, but the TYPE is not.) */
7913 CLASSTYPE_USE_TEMPLATE (newtag) = 0;
7915 /* Now, we call pushtag to put this NEWTAG into the scope of
7916 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
7917 pushtag calling push_template_decl. We don't have to do
7918 this for enums because it will already have been done in
7921 SET_IDENTIFIER_TYPE_VALUE (name, newtag);
7922 pushtag (name, newtag, /*tag_scope=*/ts_current);
7925 else if (TREE_CODE (t) == FUNCTION_DECL
7926 || DECL_FUNCTION_TEMPLATE_P (t))
7928 /* Build new TYPE_METHODS. */
7931 if (TREE_CODE (t) == TEMPLATE_DECL)
7932 ++processing_template_decl;
7933 r = tsubst (t, args, tf_error, NULL_TREE);
7934 if (TREE_CODE (t) == TEMPLATE_DECL)
7935 --processing_template_decl;
7936 set_current_access_from_decl (r);
7937 finish_member_declaration (r);
7941 /* Build new TYPE_FIELDS. */
7942 if (TREE_CODE (t) == STATIC_ASSERT)
7945 tsubst_expr (STATIC_ASSERT_CONDITION (t), args,
7946 tf_warning_or_error, NULL_TREE,
7947 /*integral_constant_expression_p=*/true);
7948 finish_static_assert (condition,
7949 STATIC_ASSERT_MESSAGE (t),
7950 STATIC_ASSERT_SOURCE_LOCATION (t),
7953 else if (TREE_CODE (t) != CONST_DECL)
7957 /* The file and line for this declaration, to
7958 assist in error message reporting. Since we
7959 called push_tinst_level above, we don't need to
7961 input_location = DECL_SOURCE_LOCATION (t);
7963 if (TREE_CODE (t) == TEMPLATE_DECL)
7964 ++processing_template_decl;
7965 r = tsubst (t, args, tf_warning_or_error, NULL_TREE);
7966 if (TREE_CODE (t) == TEMPLATE_DECL)
7967 --processing_template_decl;
7968 if (TREE_CODE (r) == VAR_DECL)
7972 [t]he initialization (and any associated
7973 side-effects) of a static data member does
7974 not occur unless the static data member is
7975 itself used in a way that requires the
7976 definition of the static data member to
7979 Therefore, we do not substitute into the
7980 initialized for the static data member here. */
7981 finish_static_data_member_decl
7984 /*init_const_expr_p=*/false,
7985 /*asmspec_tree=*/NULL_TREE,
7987 if (DECL_INITIALIZED_IN_CLASS_P (r))
7988 check_static_variable_definition (r, TREE_TYPE (r));
7990 else if (TREE_CODE (r) == FIELD_DECL)
7992 /* Determine whether R has a valid type and can be
7993 completed later. If R is invalid, then it is
7994 replaced by error_mark_node so that it will not be
7995 added to TYPE_FIELDS. */
7996 tree rtype = TREE_TYPE (r);
7997 if (can_complete_type_without_circularity (rtype))
7998 complete_type (rtype);
8000 if (!COMPLETE_TYPE_P (rtype))
8002 cxx_incomplete_type_error (r, rtype);
8003 r = error_mark_node;
8007 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
8008 such a thing will already have been added to the field
8009 list by tsubst_enum in finish_member_declaration in the
8010 CLASSTYPE_NESTED_UTDS case above. */
8011 if (!(TREE_CODE (r) == TYPE_DECL
8012 && TREE_CODE (TREE_TYPE (r)) == ENUMERAL_TYPE
8013 && DECL_ARTIFICIAL (r)))
8015 set_current_access_from_decl (r);
8016 finish_member_declaration (r);
8023 if (TYPE_P (t) || DECL_CLASS_TEMPLATE_P (t))
8025 /* Build new CLASSTYPE_FRIEND_CLASSES. */
8027 tree friend_type = t;
8028 bool adjust_processing_template_decl = false;
8030 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
8032 /* template <class T> friend class C; */
8033 friend_type = tsubst_friend_class (friend_type, args);
8034 adjust_processing_template_decl = true;
8036 else if (TREE_CODE (friend_type) == UNBOUND_CLASS_TEMPLATE)
8038 /* template <class T> friend class C::D; */
8039 friend_type = tsubst (friend_type, args,
8040 tf_warning_or_error, NULL_TREE);
8041 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
8042 friend_type = TREE_TYPE (friend_type);
8043 adjust_processing_template_decl = true;
8045 else if (TREE_CODE (friend_type) == TYPENAME_TYPE)
8047 /* This could be either
8051 when dependent_type_p is false or
8053 template <class U> friend class T::C;
8056 friend_type = tsubst (friend_type, args,
8057 tf_warning_or_error, NULL_TREE);
8058 /* Bump processing_template_decl for correct
8059 dependent_type_p calculation. */
8060 ++processing_template_decl;
8061 if (dependent_type_p (friend_type))
8062 adjust_processing_template_decl = true;
8063 --processing_template_decl;
8065 else if (!CLASSTYPE_USE_TEMPLATE (friend_type)
8066 && hidden_name_p (TYPE_NAME (friend_type)))
8070 where C hasn't been declared yet. Let's lookup name
8071 from namespace scope directly, bypassing any name that
8072 come from dependent base class. */
8073 tree ns = decl_namespace_context (TYPE_MAIN_DECL (friend_type));
8075 /* The call to xref_tag_from_type does injection for friend
8077 push_nested_namespace (ns);
8079 xref_tag_from_type (friend_type, NULL_TREE,
8080 /*tag_scope=*/ts_current);
8081 pop_nested_namespace (ns);
8083 else if (uses_template_parms (friend_type))
8084 /* friend class C<T>; */
8085 friend_type = tsubst (friend_type, args,
8086 tf_warning_or_error, NULL_TREE);
8091 where C is already declared or
8093 friend class C<int>;
8095 We don't have to do anything in these cases. */
8097 if (adjust_processing_template_decl)
8098 /* Trick make_friend_class into realizing that the friend
8099 we're adding is a template, not an ordinary class. It's
8100 important that we use make_friend_class since it will
8101 perform some error-checking and output cross-reference
8103 ++processing_template_decl;
8105 if (friend_type != error_mark_node)
8106 make_friend_class (type, friend_type, /*complain=*/false);
8108 if (adjust_processing_template_decl)
8109 --processing_template_decl;
8113 /* Build new DECL_FRIENDLIST. */
8116 /* The file and line for this declaration, to
8117 assist in error message reporting. Since we
8118 called push_tinst_level above, we don't need to
8120 input_location = DECL_SOURCE_LOCATION (t);
8122 if (TREE_CODE (t) == TEMPLATE_DECL)
8124 ++processing_template_decl;
8125 push_deferring_access_checks (dk_no_check);
8128 r = tsubst_friend_function (t, args);
8129 add_friend (type, r, /*complain=*/false);
8130 if (TREE_CODE (t) == TEMPLATE_DECL)
8132 pop_deferring_access_checks ();
8133 --processing_template_decl;
8139 /* Set the file and line number information to whatever is given for
8140 the class itself. This puts error messages involving generated
8141 implicit functions at a predictable point, and the same point
8142 that would be used for non-template classes. */
8143 input_location = DECL_SOURCE_LOCATION (typedecl);
8145 unreverse_member_declarations (type);
8146 finish_struct_1 (type);
8147 TYPE_BEING_DEFINED (type) = 0;
8149 /* Now that the class is complete, instantiate default arguments for
8150 any member functions. We don't do this earlier because the
8151 default arguments may reference members of the class. */
8152 if (!PRIMARY_TEMPLATE_P (templ))
8153 for (t = TYPE_METHODS (type); t; t = TREE_CHAIN (t))
8154 if (TREE_CODE (t) == FUNCTION_DECL
8155 /* Implicitly generated member functions will not have template
8156 information; they are not instantiations, but instead are
8157 created "fresh" for each instantiation. */
8158 && DECL_TEMPLATE_INFO (t))
8159 tsubst_default_arguments (t);
8161 /* Some typedefs referenced from within the template code need to be access
8162 checked at template instantiation time, i.e now. These types were
8163 added to the template at parsing time. Let's get those and perform
8164 the access checks then. */
8165 perform_typedefs_access_check (pattern, args);
8166 perform_deferred_access_checks ();
8167 pop_nested_class ();
8168 maximum_field_alignment = saved_maximum_field_alignment;
8169 pop_from_top_level ();
8170 pop_deferring_access_checks ();
8173 /* The vtable for a template class can be emitted in any translation
8174 unit in which the class is instantiated. When there is no key
8175 method, however, finish_struct_1 will already have added TYPE to
8176 the keyed_classes list. */
8177 if (TYPE_CONTAINS_VPTR_P (type) && CLASSTYPE_KEY_METHOD (type))
8178 keyed_classes = tree_cons (NULL_TREE, type, keyed_classes);
8184 tsubst_template_arg (tree t, tree args, tsubst_flags_t complain, tree in_decl)
8190 else if (TYPE_P (t))
8191 r = tsubst (t, args, complain, in_decl);
8194 r = tsubst_expr (t, args, complain, in_decl,
8195 /*integral_constant_expression_p=*/true);
8196 r = fold_non_dependent_expr (r);
8201 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
8202 NONTYPE_ARGUMENT_PACK. */
8205 make_fnparm_pack (tree spec_parm)
8207 /* Collect all of the extra "packed" parameters into an
8211 tree argpack = make_node (NONTYPE_ARGUMENT_PACK);
8212 tree argtypepack = cxx_make_type (TYPE_ARGUMENT_PACK);
8213 int i, len = list_length (spec_parm);
8215 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
8216 parmvec = make_tree_vec (len);
8217 parmtypevec = make_tree_vec (len);
8218 for (i = 0; i < len; i++, spec_parm = TREE_CHAIN (spec_parm))
8220 TREE_VEC_ELT (parmvec, i) = spec_parm;
8221 TREE_VEC_ELT (parmtypevec, i) = TREE_TYPE (spec_parm);
8224 /* Build the argument packs. */
8225 SET_ARGUMENT_PACK_ARGS (argpack, parmvec);
8226 SET_ARGUMENT_PACK_ARGS (argtypepack, parmtypevec);
8227 TREE_TYPE (argpack) = argtypepack;
8232 /* Substitute ARGS into T, which is an pack expansion
8233 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
8234 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
8235 (if only a partial substitution could be performed) or
8236 ERROR_MARK_NODE if there was an error. */
8238 tsubst_pack_expansion (tree t, tree args, tsubst_flags_t complain,
8242 tree pack, packs = NULL_TREE, unsubstituted_packs = NULL_TREE;
8246 bool very_local_specializations = false;
8248 gcc_assert (PACK_EXPANSION_P (t));
8249 pattern = PACK_EXPANSION_PATTERN (t);
8251 /* Determine the argument packs that will instantiate the parameter
8252 packs used in the expansion expression. While we're at it,
8253 compute the number of arguments to be expanded and make sure it
8255 for (pack = PACK_EXPANSION_PARAMETER_PACKS (t); pack;
8256 pack = TREE_CHAIN (pack))
8258 tree parm_pack = TREE_VALUE (pack);
8259 tree arg_pack = NULL_TREE;
8260 tree orig_arg = NULL_TREE;
8262 if (TREE_CODE (parm_pack) == PARM_DECL)
8264 arg_pack = retrieve_local_specialization (parm_pack);
8265 if (arg_pack == NULL_TREE)
8267 /* This can happen for a parameter name used later in a function
8268 declaration (such as in a late-specified return type). Just
8269 make a dummy decl, since it's only used for its type. */
8270 gcc_assert (cp_unevaluated_operand != 0);
8271 arg_pack = tsubst_decl (parm_pack, args, complain);
8272 arg_pack = make_fnparm_pack (arg_pack);
8277 int level, idx, levels;
8278 template_parm_level_and_index (parm_pack, &level, &idx);
8280 levels = TMPL_ARGS_DEPTH (args);
8281 if (level <= levels)
8282 arg_pack = TMPL_ARG (args, level, idx);
8285 orig_arg = arg_pack;
8286 if (arg_pack && TREE_CODE (arg_pack) == ARGUMENT_PACK_SELECT)
8287 arg_pack = ARGUMENT_PACK_SELECT_FROM_PACK (arg_pack);
8289 if (arg_pack && !ARGUMENT_PACK_P (arg_pack))
8290 /* This can only happen if we forget to expand an argument
8291 pack somewhere else. Just return an error, silently. */
8293 result = make_tree_vec (1);
8294 TREE_VEC_ELT (result, 0) = error_mark_node;
8299 && TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack)) == 1
8300 && PACK_EXPANSION_P (TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0)))
8302 tree expansion = TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0);
8303 tree pattern = PACK_EXPANSION_PATTERN (expansion);
8304 if ((TYPE_P (pattern) && same_type_p (pattern, parm_pack))
8305 || (!TYPE_P (pattern) && cp_tree_equal (parm_pack, pattern)))
8306 /* The argument pack that the parameter maps to is just an
8307 expansion of the parameter itself, such as one would
8308 find in the implicit typedef of a class inside the
8309 class itself. Consider this parameter "unsubstituted",
8310 so that we will maintain the outer pack expansion. */
8311 arg_pack = NULL_TREE;
8317 TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack));
8319 /* It's all-or-nothing with incomplete argument packs. */
8320 if (incomplete && !ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
8321 return error_mark_node;
8323 if (ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
8328 else if (len != my_len)
8331 /* We got explicit args for some packs but not others;
8332 do nothing now and try again after deduction. */
8334 if (TREE_CODE (t) == TYPE_PACK_EXPANSION)
8335 error ("mismatched argument pack lengths while expanding "
8339 error ("mismatched argument pack lengths while expanding "
8342 return error_mark_node;
8345 /* Keep track of the parameter packs and their corresponding
8347 packs = tree_cons (parm_pack, arg_pack, packs);
8348 TREE_TYPE (packs) = orig_arg;
8351 /* We can't substitute for this parameter pack. */
8352 unsubstituted_packs = tree_cons (TREE_PURPOSE (pack),
8354 unsubstituted_packs);
8357 /* We cannot expand this expansion expression, because we don't have
8358 all of the argument packs we need. Substitute into the pattern
8359 and return a PACK_EXPANSION_*. The caller will need to deal with
8361 if (unsubstituted_packs)
8364 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
8365 new_pat = tsubst_expr (pattern, args, complain, in_decl,
8366 /*integral_constant_expression_p=*/false);
8368 new_pat = tsubst (pattern, args, complain, in_decl);
8369 return make_pack_expansion (new_pat);
8372 /* We could not find any argument packs that work. */
8374 return error_mark_node;
8376 if (!local_specializations)
8378 /* We're in a late-specified return type, so we don't have a local
8379 specializations table. Create one for doing this expansion. */
8380 very_local_specializations = true;
8381 local_specializations = htab_create (37,
8382 hash_local_specialization,
8383 eq_local_specializations,
8387 /* For each argument in each argument pack, substitute into the
8389 result = make_tree_vec (len + incomplete);
8390 for (i = 0; i < len + incomplete; ++i)
8392 /* For parameter pack, change the substitution of the parameter
8393 pack to the ith argument in its argument pack, then expand
8395 for (pack = packs; pack; pack = TREE_CHAIN (pack))
8397 tree parm = TREE_PURPOSE (pack);
8399 if (TREE_CODE (parm) == PARM_DECL)
8401 /* Select the Ith argument from the pack. */
8402 tree arg = make_node (ARGUMENT_PACK_SELECT);
8403 ARGUMENT_PACK_SELECT_FROM_PACK (arg) = TREE_VALUE (pack);
8404 ARGUMENT_PACK_SELECT_INDEX (arg) = i;
8406 register_local_specialization (arg, parm);
8412 template_parm_level_and_index (parm, &level, &idx);
8416 /* Select the Ith argument from the pack. */
8417 value = make_node (ARGUMENT_PACK_SELECT);
8418 ARGUMENT_PACK_SELECT_FROM_PACK (value) = TREE_VALUE (pack);
8419 ARGUMENT_PACK_SELECT_INDEX (value) = i;
8422 /* Update the corresponding argument. */
8423 TMPL_ARG (args, level, idx) = value;
8427 /* Substitute into the PATTERN with the altered arguments. */
8428 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
8429 TREE_VEC_ELT (result, i) =
8430 tsubst_expr (pattern, args, complain, in_decl,
8431 /*integral_constant_expression_p=*/false);
8433 TREE_VEC_ELT (result, i) = tsubst (pattern, args, complain, in_decl);
8436 /* When we have incomplete argument packs, the last "expanded"
8437 result is itself a pack expansion, which allows us
8438 to deduce more arguments. */
8439 TREE_VEC_ELT (result, i) =
8440 make_pack_expansion (TREE_VEC_ELT (result, i));
8442 if (TREE_VEC_ELT (result, i) == error_mark_node)
8444 result = error_mark_node;
8449 /* Update ARGS to restore the substitution from parameter packs to
8450 their argument packs. */
8451 for (pack = packs; pack; pack = TREE_CHAIN (pack))
8453 tree parm = TREE_PURPOSE (pack);
8455 if (TREE_CODE (parm) == PARM_DECL)
8456 register_local_specialization (TREE_TYPE (pack), parm);
8460 template_parm_level_and_index (parm, &level, &idx);
8462 /* Update the corresponding argument. */
8463 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
8464 TREE_VEC_ELT (TREE_VEC_ELT (args, level -1 ), idx) =
8467 TREE_VEC_ELT (args, idx) = TREE_TYPE (pack);
8471 if (very_local_specializations)
8473 htab_delete (local_specializations);
8474 local_specializations = NULL;
8480 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
8481 TMPL. We do this using DECL_PARM_INDEX, which should work even with
8482 parameter packs; all parms generated from a function parameter pack will
8483 have the same DECL_PARM_INDEX. */
8486 get_pattern_parm (tree parm, tree tmpl)
8488 tree pattern = DECL_TEMPLATE_RESULT (tmpl);
8491 if (DECL_ARTIFICIAL (parm))
8493 for (patparm = DECL_ARGUMENTS (pattern);
8494 patparm; patparm = TREE_CHAIN (patparm))
8495 if (DECL_ARTIFICIAL (patparm)
8496 && DECL_NAME (parm) == DECL_NAME (patparm))
8501 patparm = FUNCTION_FIRST_USER_PARM (DECL_TEMPLATE_RESULT (tmpl));
8502 patparm = chain_index (DECL_PARM_INDEX (parm)-1, patparm);
8503 gcc_assert (DECL_PARM_INDEX (patparm)
8504 == DECL_PARM_INDEX (parm));
8510 /* Substitute ARGS into the vector or list of template arguments T. */
8513 tsubst_template_args (tree t, tree args, tsubst_flags_t complain, tree in_decl)
8516 int len = TREE_VEC_LENGTH (t);
8517 int need_new = 0, i, expanded_len_adjust = 0, out;
8518 tree *elts = (tree *) alloca (len * sizeof (tree));
8520 for (i = 0; i < len; i++)
8522 tree orig_arg = TREE_VEC_ELT (t, i);
8525 if (TREE_CODE (orig_arg) == TREE_VEC)
8526 new_arg = tsubst_template_args (orig_arg, args, complain, in_decl);
8527 else if (PACK_EXPANSION_P (orig_arg))
8529 /* Substitute into an expansion expression. */
8530 new_arg = tsubst_pack_expansion (orig_arg, args, complain, in_decl);
8532 if (TREE_CODE (new_arg) == TREE_VEC)
8533 /* Add to the expanded length adjustment the number of
8534 expanded arguments. We subtract one from this
8535 measurement, because the argument pack expression
8536 itself is already counted as 1 in
8537 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
8538 the argument pack is empty. */
8539 expanded_len_adjust += TREE_VEC_LENGTH (new_arg) - 1;
8541 else if (ARGUMENT_PACK_P (orig_arg))
8543 /* Substitute into each of the arguments. */
8544 new_arg = TYPE_P (orig_arg)
8545 ? cxx_make_type (TREE_CODE (orig_arg))
8546 : make_node (TREE_CODE (orig_arg));
8548 SET_ARGUMENT_PACK_ARGS (
8550 tsubst_template_args (ARGUMENT_PACK_ARGS (orig_arg),
8551 args, complain, in_decl));
8553 if (ARGUMENT_PACK_ARGS (new_arg) == error_mark_node)
8554 new_arg = error_mark_node;
8556 if (TREE_CODE (new_arg) == NONTYPE_ARGUMENT_PACK) {
8557 TREE_TYPE (new_arg) = tsubst (TREE_TYPE (orig_arg), args,
8559 TREE_CONSTANT (new_arg) = TREE_CONSTANT (orig_arg);
8561 if (TREE_TYPE (new_arg) == error_mark_node)
8562 new_arg = error_mark_node;
8566 new_arg = tsubst_template_arg (orig_arg, args, complain, in_decl);
8568 if (new_arg == error_mark_node)
8569 return error_mark_node;
8572 if (new_arg != orig_arg)
8579 /* Make space for the expanded arguments coming from template
8581 t = make_tree_vec (len + expanded_len_adjust);
8582 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
8583 arguments for a member template.
8584 In that case each TREE_VEC in ORIG_T represents a level of template
8585 arguments, and ORIG_T won't carry any non defaulted argument count.
8586 It will rather be the nested TREE_VECs that will carry one.
8587 In other words, ORIG_T carries a non defaulted argument count only
8588 if it doesn't contain any nested TREE_VEC. */
8589 if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t))
8591 int count = GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t);
8592 count += expanded_len_adjust;
8593 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (t, count);
8595 for (i = 0, out = 0; i < len; i++)
8597 if ((PACK_EXPANSION_P (TREE_VEC_ELT (orig_t, i))
8598 || ARGUMENT_PACK_P (TREE_VEC_ELT (orig_t, i)))
8599 && TREE_CODE (elts[i]) == TREE_VEC)
8603 /* Now expand the template argument pack "in place". */
8604 for (idx = 0; idx < TREE_VEC_LENGTH (elts[i]); idx++, out++)
8605 TREE_VEC_ELT (t, out) = TREE_VEC_ELT (elts[i], idx);
8609 TREE_VEC_ELT (t, out) = elts[i];
8617 /* Return the result of substituting ARGS into the template parameters
8618 given by PARMS. If there are m levels of ARGS and m + n levels of
8619 PARMS, then the result will contain n levels of PARMS. For
8620 example, if PARMS is `template <class T> template <class U>
8621 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
8622 result will be `template <int*, double, class V>'. */
8625 tsubst_template_parms (tree parms, tree args, tsubst_flags_t complain)
8630 /* When substituting into a template, we must set
8631 PROCESSING_TEMPLATE_DECL as the template parameters may be
8632 dependent if they are based on one-another, and the dependency
8633 predicates are short-circuit outside of templates. */
8634 ++processing_template_decl;
8636 for (new_parms = &r;
8637 TMPL_PARMS_DEPTH (parms) > TMPL_ARGS_DEPTH (args);
8638 new_parms = &(TREE_CHAIN (*new_parms)),
8639 parms = TREE_CHAIN (parms))
8642 make_tree_vec (TREE_VEC_LENGTH (TREE_VALUE (parms)));
8645 for (i = 0; i < TREE_VEC_LENGTH (new_vec); ++i)
8651 if (parms == error_mark_node)
8654 tuple = TREE_VEC_ELT (TREE_VALUE (parms), i);
8656 if (tuple == error_mark_node)
8659 default_value = TREE_PURPOSE (tuple);
8660 parm_decl = TREE_VALUE (tuple);
8662 parm_decl = tsubst (parm_decl, args, complain, NULL_TREE);
8663 if (TREE_CODE (parm_decl) == PARM_DECL
8664 && invalid_nontype_parm_type_p (TREE_TYPE (parm_decl), complain))
8665 parm_decl = error_mark_node;
8666 default_value = tsubst_template_arg (default_value, args,
8667 complain, NULL_TREE);
8669 tuple = build_tree_list (default_value, parm_decl);
8670 TREE_VEC_ELT (new_vec, i) = tuple;
8674 tree_cons (size_int (TMPL_PARMS_DEPTH (parms)
8675 - TMPL_ARGS_DEPTH (args)),
8676 new_vec, NULL_TREE);
8679 --processing_template_decl;
8684 /* Substitute the ARGS into the indicated aggregate (or enumeration)
8685 type T. If T is not an aggregate or enumeration type, it is
8686 handled as if by tsubst. IN_DECL is as for tsubst. If
8687 ENTERING_SCOPE is nonzero, T is the context for a template which
8688 we are presently tsubst'ing. Return the substituted value. */
8691 tsubst_aggr_type (tree t,
8693 tsubst_flags_t complain,
8700 switch (TREE_CODE (t))
8703 if (TYPE_PTRMEMFUNC_P (t))
8704 return tsubst (TYPE_PTRMEMFUNC_FN_TYPE (t), args, complain, in_decl);
8706 /* Else fall through. */
8709 if (TYPE_TEMPLATE_INFO (t) && uses_template_parms (t))
8714 int saved_unevaluated_operand;
8715 int saved_inhibit_evaluation_warnings;
8717 /* In "sizeof(X<I>)" we need to evaluate "I". */
8718 saved_unevaluated_operand = cp_unevaluated_operand;
8719 cp_unevaluated_operand = 0;
8720 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
8721 c_inhibit_evaluation_warnings = 0;
8723 /* First, determine the context for the type we are looking
8725 context = TYPE_CONTEXT (t);
8728 context = tsubst_aggr_type (context, args, complain,
8729 in_decl, /*entering_scope=*/1);
8730 /* If context is a nested class inside a class template,
8731 it may still need to be instantiated (c++/33959). */
8732 if (TYPE_P (context))
8733 context = complete_type (context);
8736 /* Then, figure out what arguments are appropriate for the
8737 type we are trying to find. For example, given:
8739 template <class T> struct S;
8740 template <class T, class U> void f(T, U) { S<U> su; }
8742 and supposing that we are instantiating f<int, double>,
8743 then our ARGS will be {int, double}, but, when looking up
8744 S we only want {double}. */
8745 argvec = tsubst_template_args (TYPE_TI_ARGS (t), args,
8747 if (argvec == error_mark_node)
8748 r = error_mark_node;
8751 r = lookup_template_class (t, argvec, in_decl, context,
8752 entering_scope, complain);
8753 r = cp_build_qualified_type_real (r, TYPE_QUALS (t), complain);
8756 cp_unevaluated_operand = saved_unevaluated_operand;
8757 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
8762 /* This is not a template type, so there's nothing to do. */
8766 return tsubst (t, args, complain, in_decl);
8770 /* Substitute into the default argument ARG (a default argument for
8771 FN), which has the indicated TYPE. */
8774 tsubst_default_argument (tree fn, tree type, tree arg)
8776 tree saved_class_ptr = NULL_TREE;
8777 tree saved_class_ref = NULL_TREE;
8779 /* This default argument came from a template. Instantiate the
8780 default argument here, not in tsubst. In the case of
8789 we must be careful to do name lookup in the scope of S<T>,
8790 rather than in the current class. */
8791 push_access_scope (fn);
8792 /* The "this" pointer is not valid in a default argument. */
8795 saved_class_ptr = current_class_ptr;
8796 cp_function_chain->x_current_class_ptr = NULL_TREE;
8797 saved_class_ref = current_class_ref;
8798 cp_function_chain->x_current_class_ref = NULL_TREE;
8801 push_deferring_access_checks(dk_no_deferred);
8802 /* The default argument expression may cause implicitly defined
8803 member functions to be synthesized, which will result in garbage
8804 collection. We must treat this situation as if we were within
8805 the body of function so as to avoid collecting live data on the
8808 arg = tsubst_expr (arg, DECL_TI_ARGS (fn),
8809 tf_warning_or_error, NULL_TREE,
8810 /*integral_constant_expression_p=*/false);
8812 pop_deferring_access_checks();
8814 /* Restore the "this" pointer. */
8817 cp_function_chain->x_current_class_ptr = saved_class_ptr;
8818 cp_function_chain->x_current_class_ref = saved_class_ref;
8821 /* Make sure the default argument is reasonable. */
8822 arg = check_default_argument (type, arg);
8824 pop_access_scope (fn);
8829 /* Substitute into all the default arguments for FN. */
8832 tsubst_default_arguments (tree fn)
8837 tmpl_args = DECL_TI_ARGS (fn);
8839 /* If this function is not yet instantiated, we certainly don't need
8840 its default arguments. */
8841 if (uses_template_parms (tmpl_args))
8844 for (arg = TYPE_ARG_TYPES (TREE_TYPE (fn));
8846 arg = TREE_CHAIN (arg))
8847 if (TREE_PURPOSE (arg))
8848 TREE_PURPOSE (arg) = tsubst_default_argument (fn,
8850 TREE_PURPOSE (arg));
8853 /* Substitute the ARGS into the T, which is a _DECL. Return the
8854 result of the substitution. Issue error and warning messages under
8855 control of COMPLAIN. */
8858 tsubst_decl (tree t, tree args, tsubst_flags_t complain)
8860 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
8861 location_t saved_loc;
8866 /* Set the filename and linenumber to improve error-reporting. */
8867 saved_loc = input_location;
8868 input_location = DECL_SOURCE_LOCATION (t);
8870 switch (TREE_CODE (t))
8874 /* We can get here when processing a member function template,
8875 member class template, or template template parameter. */
8876 tree decl = DECL_TEMPLATE_RESULT (t);
8881 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
8883 /* Template template parameter is treated here. */
8884 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8885 if (new_type == error_mark_node)
8886 RETURN (error_mark_node);
8889 TREE_CHAIN (r) = NULL_TREE;
8890 TREE_TYPE (r) = new_type;
8891 DECL_TEMPLATE_RESULT (r)
8892 = build_decl (DECL_SOURCE_LOCATION (decl),
8893 TYPE_DECL, DECL_NAME (decl), new_type);
8894 DECL_TEMPLATE_PARMS (r)
8895 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
8897 TYPE_NAME (new_type) = r;
8901 /* We might already have an instance of this template.
8902 The ARGS are for the surrounding class type, so the
8903 full args contain the tsubst'd args for the context,
8904 plus the innermost args from the template decl. */
8905 tmpl_args = DECL_CLASS_TEMPLATE_P (t)
8906 ? CLASSTYPE_TI_ARGS (TREE_TYPE (t))
8907 : DECL_TI_ARGS (DECL_TEMPLATE_RESULT (t));
8908 /* Because this is a template, the arguments will still be
8909 dependent, even after substitution. If
8910 PROCESSING_TEMPLATE_DECL is not set, the dependency
8911 predicates will short-circuit. */
8912 ++processing_template_decl;
8913 full_args = tsubst_template_args (tmpl_args, args,
8915 --processing_template_decl;
8916 if (full_args == error_mark_node)
8917 RETURN (error_mark_node);
8919 /* If this is a default template template argument,
8920 tsubst might not have changed anything. */
8921 if (full_args == tmpl_args)
8924 hash = hash_tmpl_and_args (t, full_args);
8925 spec = retrieve_specialization (t, full_args, hash);
8926 if (spec != NULL_TREE)
8932 /* Make a new template decl. It will be similar to the
8933 original, but will record the current template arguments.
8934 We also create a new function declaration, which is just
8935 like the old one, but points to this new template, rather
8936 than the old one. */
8938 gcc_assert (DECL_LANG_SPECIFIC (r) != 0);
8939 TREE_CHAIN (r) = NULL_TREE;
8941 DECL_TEMPLATE_INFO (r) = build_template_info (t, args);
8943 if (TREE_CODE (decl) == TYPE_DECL)
8946 ++processing_template_decl;
8947 new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8948 --processing_template_decl;
8949 if (new_type == error_mark_node)
8950 RETURN (error_mark_node);
8952 TREE_TYPE (r) = new_type;
8953 CLASSTYPE_TI_TEMPLATE (new_type) = r;
8954 DECL_TEMPLATE_RESULT (r) = TYPE_MAIN_DECL (new_type);
8955 DECL_TI_ARGS (r) = CLASSTYPE_TI_ARGS (new_type);
8956 DECL_CONTEXT (r) = TYPE_CONTEXT (new_type);
8961 ++processing_template_decl;
8962 new_decl = tsubst (decl, args, complain, in_decl);
8963 --processing_template_decl;
8964 if (new_decl == error_mark_node)
8965 RETURN (error_mark_node);
8967 DECL_TEMPLATE_RESULT (r) = new_decl;
8968 DECL_TI_TEMPLATE (new_decl) = r;
8969 TREE_TYPE (r) = TREE_TYPE (new_decl);
8970 DECL_TI_ARGS (r) = DECL_TI_ARGS (new_decl);
8971 DECL_CONTEXT (r) = DECL_CONTEXT (new_decl);
8974 SET_DECL_IMPLICIT_INSTANTIATION (r);
8975 DECL_TEMPLATE_INSTANTIATIONS (r) = NULL_TREE;
8976 DECL_TEMPLATE_SPECIALIZATIONS (r) = NULL_TREE;
8978 /* The template parameters for this new template are all the
8979 template parameters for the old template, except the
8980 outermost level of parameters. */
8981 DECL_TEMPLATE_PARMS (r)
8982 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
8985 if (PRIMARY_TEMPLATE_P (t))
8986 DECL_PRIMARY_TEMPLATE (r) = r;
8988 if (TREE_CODE (decl) != TYPE_DECL)
8989 /* Record this non-type partial instantiation. */
8990 register_specialization (r, t,
8991 DECL_TI_ARGS (DECL_TEMPLATE_RESULT (r)),
8999 tree argvec = NULL_TREE;
9007 /* Nobody should be tsubst'ing into non-template functions. */
9008 gcc_assert (DECL_TEMPLATE_INFO (t) != NULL_TREE);
9010 if (TREE_CODE (DECL_TI_TEMPLATE (t)) == TEMPLATE_DECL)
9015 /* If T is not dependent, just return it. We have to
9016 increment PROCESSING_TEMPLATE_DECL because
9017 value_dependent_expression_p assumes that nothing is
9018 dependent when PROCESSING_TEMPLATE_DECL is zero. */
9019 ++processing_template_decl;
9020 dependent_p = value_dependent_expression_p (t);
9021 --processing_template_decl;
9025 /* Calculate the most general template of which R is a
9026 specialization, and the complete set of arguments used to
9028 gen_tmpl = most_general_template (DECL_TI_TEMPLATE (t));
9029 argvec = tsubst_template_args (DECL_TI_ARGS
9030 (DECL_TEMPLATE_RESULT
9031 (DECL_TI_TEMPLATE (t))),
9032 args, complain, in_decl);
9034 /* Check to see if we already have this specialization. */
9035 hash = hash_tmpl_and_args (gen_tmpl, argvec);
9036 spec = retrieve_specialization (gen_tmpl, argvec, hash);
9044 /* We can see more levels of arguments than parameters if
9045 there was a specialization of a member template, like
9048 template <class T> struct S { template <class U> void f(); }
9049 template <> template <class U> void S<int>::f(U);
9051 Here, we'll be substituting into the specialization,
9052 because that's where we can find the code we actually
9053 want to generate, but we'll have enough arguments for
9054 the most general template.
9056 We also deal with the peculiar case:
9058 template <class T> struct S {
9059 template <class U> friend void f();
9061 template <class U> void f() {}
9063 template void f<double>();
9065 Here, the ARGS for the instantiation of will be {int,
9066 double}. But, we only need as many ARGS as there are
9067 levels of template parameters in CODE_PATTERN. We are
9068 careful not to get fooled into reducing the ARGS in
9071 template <class T> struct S { template <class U> void f(U); }
9072 template <class T> template <> void S<T>::f(int) {}
9074 which we can spot because the pattern will be a
9075 specialization in this case. */
9076 args_depth = TMPL_ARGS_DEPTH (args);
9078 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (t)));
9079 if (args_depth > parms_depth
9080 && !DECL_TEMPLATE_SPECIALIZATION (t))
9081 args = get_innermost_template_args (args, parms_depth);
9085 /* This special case arises when we have something like this:
9087 template <class T> struct S {
9088 friend void f<int>(int, double);
9091 Here, the DECL_TI_TEMPLATE for the friend declaration
9092 will be an IDENTIFIER_NODE. We are being called from
9093 tsubst_friend_function, and we want only to create a
9094 new decl (R) with appropriate types so that we can call
9095 determine_specialization. */
9096 gen_tmpl = NULL_TREE;
9099 if (DECL_CLASS_SCOPE_P (t))
9101 if (DECL_NAME (t) == constructor_name (DECL_CONTEXT (t)))
9105 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args,
9106 complain, t, /*entering_scope=*/1);
9111 ctx = DECL_CONTEXT (t);
9113 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9114 if (type == error_mark_node)
9115 RETURN (error_mark_node);
9117 /* We do NOT check for matching decls pushed separately at this
9118 point, as they may not represent instantiations of this
9119 template, and in any case are considered separate under the
9122 DECL_USE_TEMPLATE (r) = 0;
9123 TREE_TYPE (r) = type;
9124 /* Clear out the mangled name and RTL for the instantiation. */
9125 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
9126 SET_DECL_RTL (r, NULL_RTX);
9127 /* Leave DECL_INITIAL set on deleted instantiations. */
9128 if (!DECL_DELETED_FN (r))
9129 DECL_INITIAL (r) = NULL_TREE;
9130 DECL_CONTEXT (r) = ctx;
9132 if (member && DECL_CONV_FN_P (r))
9133 /* Type-conversion operator. Reconstruct the name, in
9134 case it's the name of one of the template's parameters. */
9135 DECL_NAME (r) = mangle_conv_op_name_for_type (TREE_TYPE (type));
9137 DECL_ARGUMENTS (r) = tsubst (DECL_ARGUMENTS (t), args,
9139 DECL_RESULT (r) = NULL_TREE;
9141 TREE_STATIC (r) = 0;
9142 TREE_PUBLIC (r) = TREE_PUBLIC (t);
9143 DECL_EXTERNAL (r) = 1;
9144 /* If this is an instantiation of a function with internal
9145 linkage, we already know what object file linkage will be
9146 assigned to the instantiation. */
9147 DECL_INTERFACE_KNOWN (r) = !TREE_PUBLIC (r);
9148 DECL_DEFER_OUTPUT (r) = 0;
9149 TREE_CHAIN (r) = NULL_TREE;
9150 DECL_PENDING_INLINE_INFO (r) = 0;
9151 DECL_PENDING_INLINE_P (r) = 0;
9152 DECL_SAVED_TREE (r) = NULL_TREE;
9153 DECL_STRUCT_FUNCTION (r) = NULL;
9155 /* We'll re-clone as appropriate in instantiate_template. */
9156 DECL_CLONED_FUNCTION (r) = NULL_TREE;
9158 /* If we aren't complaining now, return on error before we register
9159 the specialization so that we'll complain eventually. */
9160 if ((complain & tf_error) == 0
9161 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
9162 && !grok_op_properties (r, /*complain=*/false))
9163 RETURN (error_mark_node);
9165 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
9166 this in the special friend case mentioned above where
9167 GEN_TMPL is NULL. */
9170 DECL_TEMPLATE_INFO (r)
9171 = build_template_info (gen_tmpl, argvec);
9172 SET_DECL_IMPLICIT_INSTANTIATION (r);
9173 register_specialization (r, gen_tmpl, argvec, false, hash);
9175 /* We're not supposed to instantiate default arguments
9176 until they are called, for a template. But, for a
9179 template <class T> void f ()
9180 { extern void g(int i = T()); }
9182 we should do the substitution when the template is
9183 instantiated. We handle the member function case in
9184 instantiate_class_template since the default arguments
9185 might refer to other members of the class. */
9187 && !PRIMARY_TEMPLATE_P (gen_tmpl)
9188 && !uses_template_parms (argvec))
9189 tsubst_default_arguments (r);
9192 DECL_TEMPLATE_INFO (r) = NULL_TREE;
9194 /* Copy the list of befriending classes. */
9195 for (friends = &DECL_BEFRIENDING_CLASSES (r);
9197 friends = &TREE_CHAIN (*friends))
9199 *friends = copy_node (*friends);
9200 TREE_VALUE (*friends) = tsubst (TREE_VALUE (*friends),
9205 if (DECL_CONSTRUCTOR_P (r) || DECL_DESTRUCTOR_P (r))
9207 maybe_retrofit_in_chrg (r);
9208 if (DECL_CONSTRUCTOR_P (r))
9209 grok_ctor_properties (ctx, r);
9210 /* If this is an instantiation of a member template, clone it.
9211 If it isn't, that'll be handled by
9212 clone_constructors_and_destructors. */
9213 if (PRIMARY_TEMPLATE_P (gen_tmpl))
9214 clone_function_decl (r, /*update_method_vec_p=*/0);
9216 else if ((complain & tf_error) != 0
9217 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
9218 && !grok_op_properties (r, /*complain=*/true))
9219 RETURN (error_mark_node);
9221 if (DECL_FRIEND_P (t) && DECL_FRIEND_CONTEXT (t))
9222 SET_DECL_FRIEND_CONTEXT (r,
9223 tsubst (DECL_FRIEND_CONTEXT (t),
9224 args, complain, in_decl));
9226 /* Possibly limit visibility based on template args. */
9227 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
9228 if (DECL_VISIBILITY_SPECIFIED (t))
9230 DECL_VISIBILITY_SPECIFIED (r) = 0;
9232 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
9234 determine_visibility (r);
9235 if (DECL_DEFAULTED_OUTSIDE_CLASS_P (r)
9236 && !processing_template_decl)
9237 defaulted_late_check (r);
9239 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
9240 args, complain, in_decl);
9246 tree type = NULL_TREE;
9248 tree expanded_types = NULL_TREE;
9249 tree prev_r = NULL_TREE;
9250 tree first_r = NULL_TREE;
9252 if (FUNCTION_PARAMETER_PACK_P (t))
9254 /* If there is a local specialization that isn't a
9255 parameter pack, it means that we're doing a "simple"
9256 substitution from inside tsubst_pack_expansion. Just
9257 return the local specialization (which will be a single
9259 tree spec = retrieve_local_specialization (t);
9261 && TREE_CODE (spec) == PARM_DECL
9262 && TREE_CODE (TREE_TYPE (spec)) != TYPE_PACK_EXPANSION)
9265 /* Expand the TYPE_PACK_EXPANSION that provides the types for
9266 the parameters in this function parameter pack. */
9267 expanded_types = tsubst_pack_expansion (TREE_TYPE (t), args,
9269 if (TREE_CODE (expanded_types) == TREE_VEC)
9271 len = TREE_VEC_LENGTH (expanded_types);
9273 /* Zero-length parameter packs are boring. Just substitute
9276 RETURN (tsubst (TREE_CHAIN (t), args, complain,
9281 /* All we did was update the type. Make a note of that. */
9282 type = expanded_types;
9283 expanded_types = NULL_TREE;
9287 /* Loop through all of the parameter's we'll build. When T is
9288 a function parameter pack, LEN is the number of expanded
9289 types in EXPANDED_TYPES; otherwise, LEN is 1. */
9291 for (i = 0; i < len; ++i)
9295 if (DECL_TEMPLATE_PARM_P (t))
9296 SET_DECL_TEMPLATE_PARM_P (r);
9298 /* An argument of a function parameter pack is not a parameter
9300 FUNCTION_PARAMETER_PACK_P (r) = false;
9303 /* We're on the Ith parameter of the function parameter
9306 /* Get the Ith type. */
9307 type = TREE_VEC_ELT (expanded_types, i);
9310 /* Rename the parameter to include the index. */
9312 make_ith_pack_parameter_name (DECL_NAME (r), i);
9315 /* We're dealing with a normal parameter. */
9316 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9318 type = type_decays_to (type);
9319 TREE_TYPE (r) = type;
9320 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
9322 if (DECL_INITIAL (r))
9324 if (TREE_CODE (DECL_INITIAL (r)) != TEMPLATE_PARM_INDEX)
9325 DECL_INITIAL (r) = TREE_TYPE (r);
9327 DECL_INITIAL (r) = tsubst (DECL_INITIAL (r), args,
9331 DECL_CONTEXT (r) = NULL_TREE;
9333 if (!DECL_TEMPLATE_PARM_P (r))
9334 DECL_ARG_TYPE (r) = type_passed_as (type);
9336 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
9337 args, complain, in_decl);
9339 /* Keep track of the first new parameter we
9340 generate. That's what will be returned to the
9345 /* Build a proper chain of parameters when substituting
9346 into a function parameter pack. */
9348 TREE_CHAIN (prev_r) = r;
9352 TREE_CHAIN (r) = tsubst (TREE_CHAIN (t), args,
9353 complain, TREE_CHAIN (t));
9355 /* FIRST_R contains the start of the chain we've built. */
9365 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9366 if (type == error_mark_node)
9367 RETURN (error_mark_node);
9368 TREE_TYPE (r) = type;
9369 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
9371 /* DECL_INITIAL gives the number of bits in a bit-field. */
9373 = tsubst_expr (DECL_INITIAL (t), args,
9375 /*integral_constant_expression_p=*/true);
9376 /* We don't have to set DECL_CONTEXT here; it is set by
9377 finish_member_declaration. */
9378 TREE_CHAIN (r) = NULL_TREE;
9379 if (VOID_TYPE_P (type))
9380 error ("instantiation of %q+D as type %qT", r, type);
9382 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
9383 args, complain, in_decl);
9388 /* We reach here only for member using decls. */
9389 if (DECL_DEPENDENT_P (t))
9391 r = do_class_using_decl
9392 (tsubst_copy (USING_DECL_SCOPE (t), args, complain, in_decl),
9393 tsubst_copy (DECL_NAME (t), args, complain, in_decl));
9395 r = error_mark_node;
9398 TREE_PROTECTED (r) = TREE_PROTECTED (t);
9399 TREE_PRIVATE (r) = TREE_PRIVATE (t);
9405 TREE_CHAIN (r) = NULL_TREE;
9412 tree argvec = NULL_TREE;
9413 tree gen_tmpl = NULL_TREE;
9415 tree tmpl = NULL_TREE;
9417 tree type = NULL_TREE;
9420 if (TREE_CODE (t) == TYPE_DECL
9421 && t == TYPE_MAIN_DECL (TREE_TYPE (t)))
9423 /* If this is the canonical decl, we don't have to
9424 mess with instantiations, and often we can't (for
9425 typename, template type parms and such). Note that
9426 TYPE_NAME is not correct for the above test if
9427 we've copied the type for a typedef. */
9428 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9429 if (type == error_mark_node)
9430 RETURN (error_mark_node);
9431 r = TYPE_NAME (type);
9435 /* Check to see if we already have the specialization we
9438 if (DECL_CLASS_SCOPE_P (t) || DECL_NAMESPACE_SCOPE_P (t))
9440 /* T is a static data member or namespace-scope entity.
9441 We have to substitute into namespace-scope variables
9442 (even though such entities are never templates) because
9445 template <class T> void f() { extern T t; }
9447 where the entity referenced is not known until
9448 instantiation time. */
9450 ctx = DECL_CONTEXT (t);
9451 if (DECL_CLASS_SCOPE_P (t))
9453 ctx = tsubst_aggr_type (ctx, args,
9455 in_decl, /*entering_scope=*/1);
9456 /* If CTX is unchanged, then T is in fact the
9457 specialization we want. That situation occurs when
9458 referencing a static data member within in its own
9459 class. We can use pointer equality, rather than
9460 same_type_p, because DECL_CONTEXT is always
9462 if (ctx == DECL_CONTEXT (t))
9468 tmpl = DECL_TI_TEMPLATE (t);
9469 gen_tmpl = most_general_template (tmpl);
9470 argvec = tsubst (DECL_TI_ARGS (t), args, complain, in_decl);
9471 hash = hash_tmpl_and_args (gen_tmpl, argvec);
9472 spec = retrieve_specialization (gen_tmpl, argvec, hash);
9477 /* A local variable. */
9479 /* Subsequent calls to pushdecl will fill this in. */
9481 spec = retrieve_local_specialization (t);
9483 /* If we already have the specialization we need, there is
9484 nothing more to do. */
9491 /* Create a new node for the specialization we need. */
9493 if (type == NULL_TREE)
9495 if (is_typedef_decl (t))
9496 type = DECL_ORIGINAL_TYPE (t);
9498 type = TREE_TYPE (t);
9499 type = tsubst (type, args, complain, in_decl);
9501 if (TREE_CODE (r) == VAR_DECL)
9503 /* Even if the original location is out of scope, the
9504 newly substituted one is not. */
9505 DECL_DEAD_FOR_LOCAL (r) = 0;
9506 DECL_INITIALIZED_P (r) = 0;
9507 DECL_TEMPLATE_INSTANTIATED (r) = 0;
9508 if (type == error_mark_node)
9509 RETURN (error_mark_node);
9510 if (TREE_CODE (type) == FUNCTION_TYPE)
9512 /* It may seem that this case cannot occur, since:
9517 declares a function, not a variable. However:
9520 template <typename T> void g() { T t; }
9521 template void g<f>();
9523 is an attempt to declare a variable with function
9525 error ("variable %qD has function type",
9526 /* R is not yet sufficiently initialized, so we
9527 just use its name. */
9529 RETURN (error_mark_node);
9531 type = complete_type (type);
9532 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r)
9533 = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (t);
9534 type = check_var_type (DECL_NAME (r), type);
9536 if (DECL_HAS_VALUE_EXPR_P (t))
9538 tree ve = DECL_VALUE_EXPR (t);
9539 ve = tsubst_expr (ve, args, complain, in_decl,
9540 /*constant_expression_p=*/false);
9541 SET_DECL_VALUE_EXPR (r, ve);
9544 else if (DECL_SELF_REFERENCE_P (t))
9545 SET_DECL_SELF_REFERENCE_P (r);
9546 TREE_TYPE (r) = type;
9547 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
9548 DECL_CONTEXT (r) = ctx;
9549 /* Clear out the mangled name and RTL for the instantiation. */
9550 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
9551 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
9552 SET_DECL_RTL (r, NULL_RTX);
9553 /* The initializer must not be expanded until it is required;
9555 DECL_INITIAL (r) = NULL_TREE;
9556 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
9557 SET_DECL_RTL (r, NULL_RTX);
9558 DECL_SIZE (r) = DECL_SIZE_UNIT (r) = 0;
9559 if (TREE_CODE (r) == VAR_DECL)
9561 /* Possibly limit visibility based on template args. */
9562 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
9563 if (DECL_VISIBILITY_SPECIFIED (t))
9565 DECL_VISIBILITY_SPECIFIED (r) = 0;
9567 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
9569 determine_visibility (r);
9574 /* A static data member declaration is always marked
9575 external when it is declared in-class, even if an
9576 initializer is present. We mimic the non-template
9578 DECL_EXTERNAL (r) = 1;
9580 register_specialization (r, gen_tmpl, argvec, false, hash);
9581 DECL_TEMPLATE_INFO (r) = build_template_info (tmpl, argvec);
9582 SET_DECL_IMPLICIT_INSTANTIATION (r);
9584 else if (cp_unevaluated_operand)
9586 /* We're substituting this var in a decltype outside of its
9587 scope, such as for a lambda return type. Don't add it to
9588 local_specializations, do perform auto deduction. */
9589 tree auto_node = type_uses_auto (type);
9591 = tsubst_expr (DECL_INITIAL (t), args, complain, in_decl,
9592 /*constant_expression_p=*/false);
9594 if (auto_node && init && describable_type (init))
9596 type = do_auto_deduction (type, init, auto_node);
9597 TREE_TYPE (r) = type;
9601 register_local_specialization (r, t);
9603 TREE_CHAIN (r) = NULL_TREE;
9605 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r),
9607 args, complain, in_decl);
9609 /* Preserve a typedef that names a type. */
9610 if (is_typedef_decl (r))
9612 DECL_ORIGINAL_TYPE (r) = NULL_TREE;
9613 set_underlying_type (r);
9626 /* Restore the file and line information. */
9627 input_location = saved_loc;
9632 /* Substitute into the ARG_TYPES of a function type. */
9635 tsubst_arg_types (tree arg_types,
9637 tsubst_flags_t complain,
9640 tree remaining_arg_types;
9641 tree type = NULL_TREE;
9643 tree expanded_args = NULL_TREE;
9646 if (!arg_types || arg_types == void_list_node)
9649 remaining_arg_types = tsubst_arg_types (TREE_CHAIN (arg_types),
9650 args, complain, in_decl);
9651 if (remaining_arg_types == error_mark_node)
9652 return error_mark_node;
9654 if (PACK_EXPANSION_P (TREE_VALUE (arg_types)))
9656 /* For a pack expansion, perform substitution on the
9657 entire expression. Later on, we'll handle the arguments
9659 expanded_args = tsubst_pack_expansion (TREE_VALUE (arg_types),
9660 args, complain, in_decl);
9662 if (TREE_CODE (expanded_args) == TREE_VEC)
9663 /* So that we'll spin through the parameters, one by one. */
9664 i = TREE_VEC_LENGTH (expanded_args);
9667 /* We only partially substituted into the parameter
9668 pack. Our type is TYPE_PACK_EXPANSION. */
9669 type = expanded_args;
9670 expanded_args = NULL_TREE;
9678 type = TREE_VEC_ELT (expanded_args, i);
9680 type = tsubst (TREE_VALUE (arg_types), args, complain, in_decl);
9682 if (type == error_mark_node)
9683 return error_mark_node;
9684 if (VOID_TYPE_P (type))
9686 if (complain & tf_error)
9688 error ("invalid parameter type %qT", type);
9690 error ("in declaration %q+D", in_decl);
9692 return error_mark_node;
9695 /* Do array-to-pointer, function-to-pointer conversion, and ignore
9696 top-level qualifiers as required. */
9697 type = TYPE_MAIN_VARIANT (type_decays_to (type));
9699 /* We do not substitute into default arguments here. The standard
9700 mandates that they be instantiated only when needed, which is
9701 done in build_over_call. */
9702 default_arg = TREE_PURPOSE (arg_types);
9704 if (default_arg && TREE_CODE (default_arg) == DEFAULT_ARG)
9706 /* We've instantiated a template before its default arguments
9707 have been parsed. This can happen for a nested template
9708 class, and is not an error unless we require the default
9709 argument in a call of this function. */
9710 remaining_arg_types =
9711 tree_cons (default_arg, type, remaining_arg_types);
9712 VEC_safe_push (tree, gc, DEFARG_INSTANTIATIONS (default_arg),
9713 remaining_arg_types);
9716 remaining_arg_types =
9717 hash_tree_cons (default_arg, type, remaining_arg_types);
9720 return remaining_arg_types;
9723 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
9724 *not* handle the exception-specification for FNTYPE, because the
9725 initial substitution of explicitly provided template parameters
9726 during argument deduction forbids substitution into the
9727 exception-specification:
9731 All references in the function type of the function template to the
9732 corresponding template parameters are replaced by the specified tem-
9733 plate argument values. If a substitution in a template parameter or
9734 in the function type of the function template results in an invalid
9735 type, type deduction fails. [Note: The equivalent substitution in
9736 exception specifications is done only when the function is instanti-
9737 ated, at which point a program is ill-formed if the substitution
9738 results in an invalid type.] */
9741 tsubst_function_type (tree t,
9743 tsubst_flags_t complain,
9750 /* The TYPE_CONTEXT is not used for function/method types. */
9751 gcc_assert (TYPE_CONTEXT (t) == NULL_TREE);
9753 /* Substitute the return type. */
9754 return_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9755 if (return_type == error_mark_node)
9756 return error_mark_node;
9757 /* The standard does not presently indicate that creation of a
9758 function type with an invalid return type is a deduction failure.
9759 However, that is clearly analogous to creating an array of "void"
9760 or a reference to a reference. This is core issue #486. */
9761 if (TREE_CODE (return_type) == ARRAY_TYPE
9762 || TREE_CODE (return_type) == FUNCTION_TYPE)
9764 if (complain & tf_error)
9766 if (TREE_CODE (return_type) == ARRAY_TYPE)
9767 error ("function returning an array");
9769 error ("function returning a function");
9771 return error_mark_node;
9774 /* Substitute the argument types. */
9775 arg_types = tsubst_arg_types (TYPE_ARG_TYPES (t), args,
9777 if (arg_types == error_mark_node)
9778 return error_mark_node;
9780 /* Construct a new type node and return it. */
9781 if (TREE_CODE (t) == FUNCTION_TYPE)
9782 fntype = build_function_type (return_type, arg_types);
9785 tree r = TREE_TYPE (TREE_VALUE (arg_types));
9786 if (! MAYBE_CLASS_TYPE_P (r))
9790 Type deduction may fail for any of the following
9793 -- Attempting to create "pointer to member of T" when T
9794 is not a class type. */
9795 if (complain & tf_error)
9796 error ("creating pointer to member function of non-class type %qT",
9798 return error_mark_node;
9801 fntype = build_method_type_directly (r, return_type,
9802 TREE_CHAIN (arg_types));
9804 fntype = cp_build_qualified_type_real (fntype, TYPE_QUALS (t), complain);
9805 fntype = cp_build_type_attribute_variant (fntype, TYPE_ATTRIBUTES (t));
9810 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
9811 ARGS into that specification, and return the substituted
9812 specification. If there is no specification, return NULL_TREE. */
9815 tsubst_exception_specification (tree fntype,
9817 tsubst_flags_t complain,
9823 specs = TYPE_RAISES_EXCEPTIONS (fntype);
9824 new_specs = NULL_TREE;
9827 if (! TREE_VALUE (specs))
9834 tree expanded_specs = NULL_TREE;
9836 if (PACK_EXPANSION_P (TREE_VALUE (specs)))
9838 /* Expand the pack expansion type. */
9839 expanded_specs = tsubst_pack_expansion (TREE_VALUE (specs),
9843 if (expanded_specs == error_mark_node)
9844 return error_mark_node;
9845 else if (TREE_CODE (expanded_specs) == TREE_VEC)
9846 len = TREE_VEC_LENGTH (expanded_specs);
9849 /* We're substituting into a member template, so
9850 we got a TYPE_PACK_EXPANSION back. Add that
9851 expansion and move on. */
9852 gcc_assert (TREE_CODE (expanded_specs)
9853 == TYPE_PACK_EXPANSION);
9854 new_specs = add_exception_specifier (new_specs,
9857 specs = TREE_CHAIN (specs);
9862 for (i = 0; i < len; ++i)
9865 spec = TREE_VEC_ELT (expanded_specs, i);
9867 spec = tsubst (TREE_VALUE (specs), args, complain, in_decl);
9868 if (spec == error_mark_node)
9870 new_specs = add_exception_specifier (new_specs, spec,
9874 specs = TREE_CHAIN (specs);
9880 /* Take the tree structure T and replace template parameters used
9881 therein with the argument vector ARGS. IN_DECL is an associated
9882 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
9883 Issue error and warning messages under control of COMPLAIN. Note
9884 that we must be relatively non-tolerant of extensions here, in
9885 order to preserve conformance; if we allow substitutions that
9886 should not be allowed, we may allow argument deductions that should
9887 not succeed, and therefore report ambiguous overload situations
9888 where there are none. In theory, we could allow the substitution,
9889 but indicate that it should have failed, and allow our caller to
9890 make sure that the right thing happens, but we don't try to do this
9893 This function is used for dealing with types, decls and the like;
9894 for expressions, use tsubst_expr or tsubst_copy. */
9897 tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl)
9901 if (t == NULL_TREE || t == error_mark_node
9902 || t == integer_type_node
9903 || t == void_type_node
9904 || t == char_type_node
9905 || t == unknown_type_node
9906 || TREE_CODE (t) == NAMESPACE_DECL)
9910 return tsubst_decl (t, args, complain);
9912 if (args == NULL_TREE)
9915 if (TREE_CODE (t) == IDENTIFIER_NODE)
9916 type = IDENTIFIER_TYPE_VALUE (t);
9918 type = TREE_TYPE (t);
9920 gcc_assert (type != unknown_type_node);
9922 /* Reuse typedefs. We need to do this to handle dependent attributes,
9923 such as attribute aligned. */
9926 && TYPE_NAME (t) != TYPE_MAIN_DECL (t))
9928 tree decl = TYPE_NAME (t);
9930 if (DECL_CLASS_SCOPE_P (decl)
9931 && CLASSTYPE_TEMPLATE_INFO (DECL_CONTEXT (decl))
9932 && uses_template_parms (DECL_CONTEXT (decl)))
9934 tree tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
9935 tree gen_args = tsubst (DECL_TI_ARGS (decl), args, complain, in_decl);
9936 r = retrieve_specialization (tmpl, gen_args, 0);
9938 else if (DECL_FUNCTION_SCOPE_P (decl)
9939 && DECL_TEMPLATE_INFO (DECL_CONTEXT (decl))
9940 && uses_template_parms (DECL_TI_ARGS (DECL_CONTEXT (decl))))
9941 r = retrieve_local_specialization (decl);
9943 /* The typedef is from a non-template context. */
9949 r = cp_build_qualified_type_real
9950 (r, cp_type_quals (t) | cp_type_quals (r),
9951 complain | tf_ignore_bad_quals);
9954 /* Else we must be instantiating the typedef, so fall through. */
9958 && TREE_CODE (t) != TYPENAME_TYPE
9959 && TREE_CODE (t) != TEMPLATE_TYPE_PARM
9960 && TREE_CODE (t) != IDENTIFIER_NODE
9961 && TREE_CODE (t) != FUNCTION_TYPE
9962 && TREE_CODE (t) != METHOD_TYPE)
9963 type = tsubst (type, args, complain, in_decl);
9964 if (type == error_mark_node)
9965 return error_mark_node;
9967 switch (TREE_CODE (t))
9972 return tsubst_aggr_type (t, args, complain, in_decl,
9973 /*entering_scope=*/0);
9976 case IDENTIFIER_NODE:
9988 if (t == integer_type_node)
9991 if (TREE_CODE (TYPE_MIN_VALUE (t)) == INTEGER_CST
9992 && TREE_CODE (TYPE_MAX_VALUE (t)) == INTEGER_CST)
9996 tree max, omax = TREE_OPERAND (TYPE_MAX_VALUE (t), 0);
9998 max = tsubst_expr (omax, args, complain, in_decl,
9999 /*integral_constant_expression_p=*/false);
10001 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
10003 if (TREE_CODE (max) == NOP_EXPR
10004 && TREE_SIDE_EFFECTS (omax)
10005 && !TREE_TYPE (max))
10006 TREE_TYPE (max) = TREE_TYPE (TREE_OPERAND (max, 0));
10008 max = fold_decl_constant_value (max);
10010 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
10011 with TREE_SIDE_EFFECTS that indicates this is not an integral
10012 constant expression. */
10013 if (processing_template_decl
10014 && TREE_SIDE_EFFECTS (omax) && TREE_CODE (omax) == NOP_EXPR)
10016 gcc_assert (TREE_CODE (max) == NOP_EXPR);
10017 TREE_SIDE_EFFECTS (max) = 1;
10020 if (TREE_CODE (max) != INTEGER_CST
10021 && !at_function_scope_p ()
10022 && !TREE_SIDE_EFFECTS (max)
10023 && !value_dependent_expression_p (max))
10025 if (complain & tf_error)
10026 error ("array bound is not an integer constant");
10027 return error_mark_node;
10032 Type deduction may fail for any of the following
10035 Attempting to create an array with a size that is
10036 zero or negative. */
10037 if (integer_zerop (max) && !(complain & tf_error))
10038 /* We must fail if performing argument deduction (as
10039 indicated by the state of complain), so that
10040 another substitution can be found. */
10041 return error_mark_node;
10042 else if (TREE_CODE (max) == INTEGER_CST
10043 && INT_CST_LT (max, integer_zero_node))
10045 if (complain & tf_error)
10046 error ("creating array with negative size (%qE)", max);
10048 return error_mark_node;
10051 return compute_array_index_type (NULL_TREE, max);
10054 case TEMPLATE_TYPE_PARM:
10055 case TEMPLATE_TEMPLATE_PARM:
10056 case BOUND_TEMPLATE_TEMPLATE_PARM:
10057 case TEMPLATE_PARM_INDEX:
10062 tree arg = NULL_TREE;
10066 gcc_assert (TREE_VEC_LENGTH (args) > 0);
10067 template_parm_level_and_index (t, &level, &idx);
10069 levels = TMPL_ARGS_DEPTH (args);
10070 if (level <= levels)
10072 arg = TMPL_ARG (args, level, idx);
10074 if (arg && TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
10075 /* See through ARGUMENT_PACK_SELECT arguments. */
10076 arg = ARGUMENT_PACK_SELECT_ARG (arg);
10079 if (arg == error_mark_node)
10080 return error_mark_node;
10081 else if (arg != NULL_TREE)
10083 if (ARGUMENT_PACK_P (arg))
10084 /* If ARG is an argument pack, we don't actually want to
10085 perform a substitution here, because substitutions
10086 for argument packs are only done
10087 element-by-element. We can get to this point when
10088 substituting the type of a non-type template
10089 parameter pack, when that type actually contains
10090 template parameter packs from an outer template, e.g.,
10092 template<typename... Types> struct A {
10093 template<Types... Values> struct B { };
10097 if (TREE_CODE (t) == TEMPLATE_TYPE_PARM)
10100 gcc_assert (TYPE_P (arg));
10102 /* cv-quals from the template are discarded when
10103 substituting in a function or reference type. */
10104 if (TREE_CODE (arg) == FUNCTION_TYPE
10105 || TREE_CODE (arg) == METHOD_TYPE
10106 || TREE_CODE (arg) == REFERENCE_TYPE)
10107 quals = cp_type_quals (arg);
10109 quals = cp_type_quals (arg) | cp_type_quals (t);
10111 return cp_build_qualified_type_real
10112 (arg, quals, complain | tf_ignore_bad_quals);
10114 else if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
10116 /* We are processing a type constructed from a
10117 template template parameter. */
10118 tree argvec = tsubst (TYPE_TI_ARGS (t),
10119 args, complain, in_decl);
10120 if (argvec == error_mark_node)
10121 return error_mark_node;
10123 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
10124 are resolving nested-types in the signature of a
10125 member function templates. Otherwise ARG is a
10126 TEMPLATE_DECL and is the real template to be
10128 if (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
10129 arg = TYPE_NAME (arg);
10131 r = lookup_template_class (arg,
10133 DECL_CONTEXT (arg),
10134 /*entering_scope=*/0,
10136 return cp_build_qualified_type_real
10137 (r, TYPE_QUALS (t), complain);
10140 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
10145 /* This can happen during the attempted tsubst'ing in
10146 unify. This means that we don't yet have any information
10147 about the template parameter in question. */
10150 /* If we get here, we must have been looking at a parm for a
10151 more deeply nested template. Make a new version of this
10152 template parameter, but with a lower level. */
10153 switch (TREE_CODE (t))
10155 case TEMPLATE_TYPE_PARM:
10156 case TEMPLATE_TEMPLATE_PARM:
10157 case BOUND_TEMPLATE_TEMPLATE_PARM:
10158 if (cp_type_quals (t))
10160 r = tsubst (TYPE_MAIN_VARIANT (t), args, complain, in_decl);
10161 r = cp_build_qualified_type_real
10162 (r, cp_type_quals (t),
10163 complain | (TREE_CODE (t) == TEMPLATE_TYPE_PARM
10164 ? tf_ignore_bad_quals : 0));
10169 TEMPLATE_TYPE_PARM_INDEX (r)
10170 = reduce_template_parm_level (TEMPLATE_TYPE_PARM_INDEX (t),
10171 r, levels, args, complain);
10172 TYPE_STUB_DECL (r) = TYPE_NAME (r) = TEMPLATE_TYPE_DECL (r);
10173 TYPE_MAIN_VARIANT (r) = r;
10174 TYPE_POINTER_TO (r) = NULL_TREE;
10175 TYPE_REFERENCE_TO (r) = NULL_TREE;
10177 if (TREE_CODE (r) == TEMPLATE_TEMPLATE_PARM)
10178 /* We have reduced the level of the template
10179 template parameter, but not the levels of its
10180 template parameters, so canonical_type_parameter
10181 will not be able to find the canonical template
10182 template parameter for this level. Thus, we
10183 require structural equality checking to compare
10184 TEMPLATE_TEMPLATE_PARMs. */
10185 SET_TYPE_STRUCTURAL_EQUALITY (r);
10186 else if (TYPE_STRUCTURAL_EQUALITY_P (t))
10187 SET_TYPE_STRUCTURAL_EQUALITY (r);
10189 TYPE_CANONICAL (r) = canonical_type_parameter (r);
10191 if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
10193 tree argvec = tsubst (TYPE_TI_ARGS (t), args,
10194 complain, in_decl);
10195 if (argvec == error_mark_node)
10196 return error_mark_node;
10198 TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (r)
10199 = build_template_info (TYPE_TI_TEMPLATE (t), argvec);
10204 case TEMPLATE_PARM_INDEX:
10205 r = reduce_template_parm_level (t, type, levels, args, complain);
10209 gcc_unreachable ();
10217 tree purpose, value, chain;
10219 if (t == void_list_node)
10222 purpose = TREE_PURPOSE (t);
10225 purpose = tsubst (purpose, args, complain, in_decl);
10226 if (purpose == error_mark_node)
10227 return error_mark_node;
10229 value = TREE_VALUE (t);
10232 value = tsubst (value, args, complain, in_decl);
10233 if (value == error_mark_node)
10234 return error_mark_node;
10236 chain = TREE_CHAIN (t);
10237 if (chain && chain != void_type_node)
10239 chain = tsubst (chain, args, complain, in_decl);
10240 if (chain == error_mark_node)
10241 return error_mark_node;
10243 if (purpose == TREE_PURPOSE (t)
10244 && value == TREE_VALUE (t)
10245 && chain == TREE_CHAIN (t))
10247 return hash_tree_cons (purpose, value, chain);
10251 /* We should never be tsubsting a binfo. */
10252 gcc_unreachable ();
10255 /* A vector of template arguments. */
10256 gcc_assert (!type);
10257 return tsubst_template_args (t, args, complain, in_decl);
10260 case REFERENCE_TYPE:
10262 enum tree_code code;
10264 if (type == TREE_TYPE (t) && TREE_CODE (type) != METHOD_TYPE)
10267 code = TREE_CODE (t);
10272 Type deduction may fail for any of the following
10275 -- Attempting to create a pointer to reference type.
10276 -- Attempting to create a reference to a reference type or
10277 a reference to void.
10279 Core issue 106 says that creating a reference to a reference
10280 during instantiation is no longer a cause for failure. We
10281 only enforce this check in strict C++98 mode. */
10282 if ((TREE_CODE (type) == REFERENCE_TYPE
10283 && (((cxx_dialect == cxx98) && flag_iso) || code != REFERENCE_TYPE))
10284 || (code == REFERENCE_TYPE && TREE_CODE (type) == VOID_TYPE))
10286 static location_t last_loc;
10288 /* We keep track of the last time we issued this error
10289 message to avoid spewing a ton of messages during a
10290 single bad template instantiation. */
10291 if (complain & tf_error
10292 && last_loc != input_location)
10294 if (TREE_CODE (type) == VOID_TYPE)
10295 error ("forming reference to void");
10296 else if (code == POINTER_TYPE)
10297 error ("forming pointer to reference type %qT", type);
10299 error ("forming reference to reference type %qT", type);
10300 last_loc = input_location;
10303 return error_mark_node;
10305 else if (code == POINTER_TYPE)
10307 r = build_pointer_type (type);
10308 if (TREE_CODE (type) == METHOD_TYPE)
10309 r = build_ptrmemfunc_type (r);
10311 else if (TREE_CODE (type) == REFERENCE_TYPE)
10312 /* In C++0x, during template argument substitution, when there is an
10313 attempt to create a reference to a reference type, reference
10314 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
10316 "If a template-argument for a template-parameter T names a type
10317 that is a reference to a type A, an attempt to create the type
10318 'lvalue reference to cv T' creates the type 'lvalue reference to
10319 A,' while an attempt to create the type type rvalue reference to
10320 cv T' creates the type T"
10322 r = cp_build_reference_type
10324 TYPE_REF_IS_RVALUE (t) && TYPE_REF_IS_RVALUE (type));
10326 r = cp_build_reference_type (type, TYPE_REF_IS_RVALUE (t));
10327 r = cp_build_qualified_type_real (r, TYPE_QUALS (t), complain);
10329 if (r != error_mark_node)
10330 /* Will this ever be needed for TYPE_..._TO values? */
10337 r = tsubst (TYPE_OFFSET_BASETYPE (t), args, complain, in_decl);
10338 if (r == error_mark_node || !MAYBE_CLASS_TYPE_P (r))
10342 Type deduction may fail for any of the following
10345 -- Attempting to create "pointer to member of T" when T
10346 is not a class type. */
10347 if (complain & tf_error)
10348 error ("creating pointer to member of non-class type %qT", r);
10349 return error_mark_node;
10351 if (TREE_CODE (type) == REFERENCE_TYPE)
10353 if (complain & tf_error)
10354 error ("creating pointer to member reference type %qT", type);
10355 return error_mark_node;
10357 if (TREE_CODE (type) == VOID_TYPE)
10359 if (complain & tf_error)
10360 error ("creating pointer to member of type void");
10361 return error_mark_node;
10363 gcc_assert (TREE_CODE (type) != METHOD_TYPE);
10364 if (TREE_CODE (type) == FUNCTION_TYPE)
10366 /* The type of the implicit object parameter gets its
10367 cv-qualifiers from the FUNCTION_TYPE. */
10369 tree method_type = build_memfn_type (type, r, cp_type_quals (type));
10370 memptr = build_ptrmemfunc_type (build_pointer_type (method_type));
10371 return cp_build_qualified_type_real (memptr, cp_type_quals (t),
10375 return cp_build_qualified_type_real (build_ptrmem_type (r, type),
10379 case FUNCTION_TYPE:
10384 fntype = tsubst_function_type (t, args, complain, in_decl);
10385 if (fntype == error_mark_node)
10386 return error_mark_node;
10388 /* Substitute the exception specification. */
10389 specs = tsubst_exception_specification (t, args, complain,
10391 if (specs == error_mark_node)
10392 return error_mark_node;
10394 fntype = build_exception_variant (fntype, specs);
10399 tree domain = tsubst (TYPE_DOMAIN (t), args, complain, in_decl);
10400 if (domain == error_mark_node)
10401 return error_mark_node;
10403 /* As an optimization, we avoid regenerating the array type if
10404 it will obviously be the same as T. */
10405 if (type == TREE_TYPE (t) && domain == TYPE_DOMAIN (t))
10408 /* These checks should match the ones in grokdeclarator.
10412 The deduction may fail for any of the following reasons:
10414 -- Attempting to create an array with an element type that
10415 is void, a function type, or a reference type, or [DR337]
10416 an abstract class type. */
10417 if (TREE_CODE (type) == VOID_TYPE
10418 || TREE_CODE (type) == FUNCTION_TYPE
10419 || TREE_CODE (type) == REFERENCE_TYPE)
10421 if (complain & tf_error)
10422 error ("creating array of %qT", type);
10423 return error_mark_node;
10425 if (CLASS_TYPE_P (type) && CLASSTYPE_PURE_VIRTUALS (type))
10427 if (complain & tf_error)
10428 error ("creating array of %qT, which is an abstract class type",
10430 return error_mark_node;
10433 r = build_cplus_array_type (type, domain);
10435 if (TYPE_USER_ALIGN (t))
10437 TYPE_ALIGN (r) = TYPE_ALIGN (t);
10438 TYPE_USER_ALIGN (r) = 1;
10447 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
10448 tree e2 = tsubst (TREE_OPERAND (t, 1), args, complain, in_decl);
10450 if (e1 == error_mark_node || e2 == error_mark_node)
10451 return error_mark_node;
10453 return fold_build2_loc (input_location,
10454 TREE_CODE (t), TREE_TYPE (t), e1, e2);
10460 tree e = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
10461 if (e == error_mark_node)
10462 return error_mark_node;
10464 return fold_build1_loc (input_location, TREE_CODE (t), TREE_TYPE (t), e);
10467 case TYPENAME_TYPE:
10469 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
10470 in_decl, /*entering_scope=*/1);
10471 tree f = tsubst_copy (TYPENAME_TYPE_FULLNAME (t), args,
10472 complain, in_decl);
10474 if (ctx == error_mark_node || f == error_mark_node)
10475 return error_mark_node;
10477 if (!MAYBE_CLASS_TYPE_P (ctx))
10479 if (complain & tf_error)
10480 error ("%qT is not a class, struct, or union type", ctx);
10481 return error_mark_node;
10483 else if (!uses_template_parms (ctx) && !TYPE_BEING_DEFINED (ctx))
10485 /* Normally, make_typename_type does not require that the CTX
10486 have complete type in order to allow things like:
10488 template <class T> struct S { typename S<T>::X Y; };
10490 But, such constructs have already been resolved by this
10491 point, so here CTX really should have complete type, unless
10492 it's a partial instantiation. */
10493 if (!(complain & tf_no_class_instantiations))
10494 ctx = complete_type (ctx);
10495 if (!COMPLETE_TYPE_P (ctx))
10497 if (complain & tf_error)
10498 cxx_incomplete_type_error (NULL_TREE, ctx);
10499 return error_mark_node;
10503 f = make_typename_type (ctx, f, typename_type,
10504 (complain & tf_error) | tf_keep_type_decl);
10505 if (f == error_mark_node)
10507 if (TREE_CODE (f) == TYPE_DECL)
10509 complain |= tf_ignore_bad_quals;
10513 if (TREE_CODE (f) != TYPENAME_TYPE)
10515 if (TYPENAME_IS_ENUM_P (t) && TREE_CODE (f) != ENUMERAL_TYPE)
10516 error ("%qT resolves to %qT, which is not an enumeration type",
10518 else if (TYPENAME_IS_CLASS_P (t) && !CLASS_TYPE_P (f))
10519 error ("%qT resolves to %qT, which is is not a class type",
10523 return cp_build_qualified_type_real
10524 (f, cp_type_quals (f) | cp_type_quals (t), complain);
10527 case UNBOUND_CLASS_TEMPLATE:
10529 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
10530 in_decl, /*entering_scope=*/1);
10531 tree name = TYPE_IDENTIFIER (t);
10532 tree parm_list = DECL_TEMPLATE_PARMS (TYPE_NAME (t));
10534 if (ctx == error_mark_node || name == error_mark_node)
10535 return error_mark_node;
10538 parm_list = tsubst_template_parms (parm_list, args, complain);
10539 return make_unbound_class_template (ctx, name, parm_list, complain);
10545 gcc_unreachable ();
10549 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
10550 tree e2 = tsubst_expr (TREE_OPERAND (t, 1), args, complain, in_decl,
10551 /*integral_constant_expression_p=*/false);
10552 if (e1 == error_mark_node || e2 == error_mark_node)
10553 return error_mark_node;
10555 return build_nt (ARRAY_REF, e1, e2, NULL_TREE, NULL_TREE);
10560 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
10561 tree e2 = tsubst (TREE_OPERAND (t, 1), args, complain, in_decl);
10562 if (e1 == error_mark_node || e2 == error_mark_node)
10563 return error_mark_node;
10565 return build_qualified_name (/*type=*/NULL_TREE,
10566 e1, e2, QUALIFIED_NAME_IS_TEMPLATE (t));
10573 ++cp_unevaluated_operand;
10574 ++c_inhibit_evaluation_warnings;
10576 type = tsubst_expr (TYPEOF_TYPE_EXPR (t), args,
10578 /*integral_constant_expression_p=*/false);
10580 --cp_unevaluated_operand;
10581 --c_inhibit_evaluation_warnings;
10583 type = finish_typeof (type);
10584 return cp_build_qualified_type_real (type,
10586 | cp_type_quals (type),
10590 case DECLTYPE_TYPE:
10594 ++cp_unevaluated_operand;
10595 ++c_inhibit_evaluation_warnings;
10597 type = tsubst_expr (DECLTYPE_TYPE_EXPR (t), args,
10599 /*integral_constant_expression_p=*/false);
10601 --cp_unevaluated_operand;
10602 --c_inhibit_evaluation_warnings;
10604 if (DECLTYPE_FOR_LAMBDA_CAPTURE (t))
10605 type = lambda_capture_field_type (type);
10606 else if (DECLTYPE_FOR_LAMBDA_RETURN (t))
10607 type = lambda_return_type (type);
10609 type = finish_decltype_type
10610 (type, DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t));
10611 return cp_build_qualified_type_real (type,
10613 | cp_type_quals (type),
10617 case TYPE_ARGUMENT_PACK:
10618 case NONTYPE_ARGUMENT_PACK:
10620 tree r = TYPE_P (t)
10621 ? cxx_make_type (TREE_CODE (t))
10622 : make_node (TREE_CODE (t));
10624 tsubst_template_args (ARGUMENT_PACK_ARGS (t),
10628 SET_ARGUMENT_PACK_ARGS (r, packed_out);
10630 /* For template nontype argument packs, also substitute into
10632 if (TREE_CODE (t) == NONTYPE_ARGUMENT_PACK)
10633 TREE_TYPE (r) = tsubst (TREE_TYPE (t), args, complain, in_decl);
10640 sorry ("use of %qs in template",
10641 tree_code_name [(int) TREE_CODE (t)]);
10642 return error_mark_node;
10646 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
10647 type of the expression on the left-hand side of the "." or "->"
10651 tsubst_baselink (tree baselink, tree object_type,
10652 tree args, tsubst_flags_t complain, tree in_decl)
10655 tree qualifying_scope;
10658 tree template_args = 0;
10659 bool template_id_p = false;
10661 /* A baselink indicates a function from a base class. Both the
10662 BASELINK_ACCESS_BINFO and the base class referenced may
10663 indicate bases of the template class, rather than the
10664 instantiated class. In addition, lookups that were not
10665 ambiguous before may be ambiguous now. Therefore, we perform
10666 the lookup again. */
10667 qualifying_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (baselink));
10668 qualifying_scope = tsubst (qualifying_scope, args,
10669 complain, in_decl);
10670 fns = BASELINK_FUNCTIONS (baselink);
10671 optype = tsubst (BASELINK_OPTYPE (baselink), args, complain, in_decl);
10672 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
10674 template_id_p = true;
10675 template_args = TREE_OPERAND (fns, 1);
10676 fns = TREE_OPERAND (fns, 0);
10678 template_args = tsubst_template_args (template_args, args,
10679 complain, in_decl);
10681 name = DECL_NAME (get_first_fn (fns));
10682 if (IDENTIFIER_TYPENAME_P (name))
10683 name = mangle_conv_op_name_for_type (optype);
10684 baselink = lookup_fnfields (qualifying_scope, name, /*protect=*/1);
10686 /* If lookup found a single function, mark it as used at this
10687 point. (If it lookup found multiple functions the one selected
10688 later by overload resolution will be marked as used at that
10690 if (BASELINK_P (baselink))
10691 fns = BASELINK_FUNCTIONS (baselink);
10692 if (!template_id_p && !really_overloaded_fn (fns))
10693 mark_used (OVL_CURRENT (fns));
10695 /* Add back the template arguments, if present. */
10696 if (BASELINK_P (baselink) && template_id_p)
10697 BASELINK_FUNCTIONS (baselink)
10698 = build_nt (TEMPLATE_ID_EXPR,
10699 BASELINK_FUNCTIONS (baselink),
10701 /* Update the conversion operator type. */
10702 BASELINK_OPTYPE (baselink) = optype;
10705 object_type = current_class_type;
10706 return adjust_result_of_qualified_name_lookup (baselink,
10711 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
10712 true if the qualified-id will be a postfix-expression in-and-of
10713 itself; false if more of the postfix-expression follows the
10714 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
10718 tsubst_qualified_id (tree qualified_id, tree args,
10719 tsubst_flags_t complain, tree in_decl,
10720 bool done, bool address_p)
10726 tree template_args;
10728 gcc_assert (TREE_CODE (qualified_id) == SCOPE_REF);
10730 /* Figure out what name to look up. */
10731 name = TREE_OPERAND (qualified_id, 1);
10732 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
10734 is_template = true;
10735 template_args = TREE_OPERAND (name, 1);
10737 template_args = tsubst_template_args (template_args, args,
10738 complain, in_decl);
10739 name = TREE_OPERAND (name, 0);
10743 is_template = false;
10744 template_args = NULL_TREE;
10747 /* Substitute into the qualifying scope. When there are no ARGS, we
10748 are just trying to simplify a non-dependent expression. In that
10749 case the qualifying scope may be dependent, and, in any case,
10750 substituting will not help. */
10751 scope = TREE_OPERAND (qualified_id, 0);
10754 scope = tsubst (scope, args, complain, in_decl);
10755 expr = tsubst_copy (name, args, complain, in_decl);
10760 if (dependent_scope_p (scope))
10761 return build_qualified_name (NULL_TREE, scope, expr,
10762 QUALIFIED_NAME_IS_TEMPLATE (qualified_id));
10764 if (!BASELINK_P (name) && !DECL_P (expr))
10766 if (TREE_CODE (expr) == BIT_NOT_EXPR)
10768 /* A BIT_NOT_EXPR is used to represent a destructor. */
10769 if (!check_dtor_name (scope, TREE_OPERAND (expr, 0)))
10771 error ("qualifying type %qT does not match destructor name ~%qT",
10772 scope, TREE_OPERAND (expr, 0));
10773 expr = error_mark_node;
10776 expr = lookup_qualified_name (scope, complete_dtor_identifier,
10777 /*is_type_p=*/0, false);
10780 expr = lookup_qualified_name (scope, expr, /*is_type_p=*/0, false);
10781 if (TREE_CODE (TREE_CODE (expr) == TEMPLATE_DECL
10782 ? DECL_TEMPLATE_RESULT (expr) : expr) == TYPE_DECL)
10784 if (complain & tf_error)
10786 error ("dependent-name %qE is parsed as a non-type, but "
10787 "instantiation yields a type", qualified_id);
10788 inform (input_location, "say %<typename %E%> if a type is meant", qualified_id);
10790 return error_mark_node;
10796 check_accessibility_of_qualified_id (expr, /*object_type=*/NULL_TREE,
10798 /* Remember that there was a reference to this entity. */
10802 if (expr == error_mark_node || TREE_CODE (expr) == TREE_LIST)
10804 if (complain & tf_error)
10805 qualified_name_lookup_error (scope,
10806 TREE_OPERAND (qualified_id, 1),
10807 expr, input_location);
10808 return error_mark_node;
10812 expr = lookup_template_function (expr, template_args);
10814 if (expr == error_mark_node && complain & tf_error)
10815 qualified_name_lookup_error (scope, TREE_OPERAND (qualified_id, 1),
10816 expr, input_location);
10817 else if (TYPE_P (scope))
10819 expr = (adjust_result_of_qualified_name_lookup
10820 (expr, scope, current_class_type));
10821 expr = (finish_qualified_id_expr
10822 (scope, expr, done, address_p,
10823 QUALIFIED_NAME_IS_TEMPLATE (qualified_id),
10824 /*template_arg_p=*/false));
10827 /* Expressions do not generally have reference type. */
10828 if (TREE_CODE (expr) != SCOPE_REF
10829 /* However, if we're about to form a pointer-to-member, we just
10830 want the referenced member referenced. */
10831 && TREE_CODE (expr) != OFFSET_REF)
10832 expr = convert_from_reference (expr);
10837 /* Like tsubst, but deals with expressions. This function just replaces
10838 template parms; to finish processing the resultant expression, use
10842 tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl)
10844 enum tree_code code;
10847 if (t == NULL_TREE || t == error_mark_node || args == NULL_TREE)
10850 code = TREE_CODE (t);
10855 r = retrieve_local_specialization (t);
10860 /* This can happen for a parameter name used later in a function
10861 declaration (such as in a late-specified return type). Just
10862 make a dummy decl, since it's only used for its type. */
10863 gcc_assert (cp_unevaluated_operand != 0);
10864 /* We copy T because want to tsubst the PARM_DECL only,
10865 not the following PARM_DECLs that are chained to T. */
10867 r = tsubst_decl (c, args, complain);
10868 /* Give it the template pattern as its context; its true context
10869 hasn't been instantiated yet and this is good enough for
10871 DECL_CONTEXT (r) = DECL_CONTEXT (t);
10874 if (TREE_CODE (r) == ARGUMENT_PACK_SELECT)
10875 r = ARGUMENT_PACK_SELECT_ARG (r);
10884 if (DECL_TEMPLATE_PARM_P (t))
10885 return tsubst_copy (DECL_INITIAL (t), args, complain, in_decl);
10886 /* There is no need to substitute into namespace-scope
10888 if (DECL_NAMESPACE_SCOPE_P (t))
10890 /* If ARGS is NULL, then T is known to be non-dependent. */
10891 if (args == NULL_TREE)
10892 return integral_constant_value (t);
10894 /* Unfortunately, we cannot just call lookup_name here.
10897 template <int I> int f() {
10899 struct S { void g() { E e = a; } };
10902 When we instantiate f<7>::S::g(), say, lookup_name is not
10903 clever enough to find f<7>::a. */
10905 = tsubst_aggr_type (TREE_TYPE (t), args, complain, in_decl,
10906 /*entering_scope=*/0);
10908 for (v = TYPE_VALUES (enum_type);
10910 v = TREE_CHAIN (v))
10911 if (TREE_PURPOSE (v) == DECL_NAME (t))
10912 return TREE_VALUE (v);
10914 /* We didn't find the name. That should never happen; if
10915 name-lookup found it during preliminary parsing, we
10916 should find it again here during instantiation. */
10917 gcc_unreachable ();
10922 if (DECL_CONTEXT (t))
10926 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args, complain, in_decl,
10927 /*entering_scope=*/1);
10928 if (ctx != DECL_CONTEXT (t))
10930 tree r = lookup_field (ctx, DECL_NAME (t), 0, false);
10933 if (complain & tf_error)
10934 error ("using invalid field %qD", t);
10935 return error_mark_node;
10944 case FUNCTION_DECL:
10945 if ((DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t))
10946 || local_variable_p (t))
10947 t = tsubst (t, args, complain, in_decl);
10952 return tsubst_baselink (t, current_class_type, args, complain, in_decl);
10954 case TEMPLATE_DECL:
10955 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
10956 return tsubst (TREE_TYPE (DECL_TEMPLATE_RESULT (t)),
10957 args, complain, in_decl);
10958 else if (DECL_FUNCTION_TEMPLATE_P (t) && DECL_MEMBER_TEMPLATE_P (t))
10959 return tsubst (t, args, complain, in_decl);
10960 else if (DECL_CLASS_SCOPE_P (t)
10961 && uses_template_parms (DECL_CONTEXT (t)))
10963 /* Template template argument like the following example need
10966 template <template <class> class TT> struct C {};
10967 template <class T> struct D {
10968 template <class U> struct E {};
10973 We are processing the template argument `E' in #1 for
10974 the template instantiation #2. Originally, `E' is a
10975 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
10976 have to substitute this with one having context `D<int>'. */
10978 tree context = tsubst (DECL_CONTEXT (t), args, complain, in_decl);
10979 return lookup_field (context, DECL_NAME(t), 0, false);
10982 /* Ordinary template template argument. */
10986 case REINTERPRET_CAST_EXPR:
10987 case CONST_CAST_EXPR:
10988 case STATIC_CAST_EXPR:
10989 case DYNAMIC_CAST_EXPR:
10992 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
10993 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
10996 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
10998 /* We only want to compute the number of arguments. */
10999 tree expanded = tsubst_pack_expansion (TREE_OPERAND (t, 0), args,
11000 complain, in_decl);
11003 if (TREE_CODE (expanded) == TREE_VEC)
11004 len = TREE_VEC_LENGTH (expanded);
11006 if (expanded == error_mark_node)
11007 return error_mark_node;
11008 else if (PACK_EXPANSION_P (expanded)
11009 || (TREE_CODE (expanded) == TREE_VEC
11011 && PACK_EXPANSION_P (TREE_VEC_ELT (expanded, len-1))))
11013 if (TREE_CODE (expanded) == TREE_VEC)
11014 expanded = TREE_VEC_ELT (expanded, len - 1);
11016 if (TYPE_P (expanded))
11017 return cxx_sizeof_or_alignof_type (expanded, SIZEOF_EXPR,
11018 complain & tf_error);
11020 return cxx_sizeof_or_alignof_expr (expanded, SIZEOF_EXPR,
11021 complain & tf_error);
11024 return build_int_cst (size_type_node, len);
11030 case TRUTH_NOT_EXPR:
11033 case UNARY_PLUS_EXPR: /* Unary + */
11038 case REALPART_EXPR:
11039 case IMAGPART_EXPR:
11041 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
11042 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
11044 case COMPONENT_REF:
11049 object = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
11050 name = TREE_OPERAND (t, 1);
11051 if (TREE_CODE (name) == BIT_NOT_EXPR)
11053 name = tsubst_copy (TREE_OPERAND (name, 0), args,
11054 complain, in_decl);
11055 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
11057 else if (TREE_CODE (name) == SCOPE_REF
11058 && TREE_CODE (TREE_OPERAND (name, 1)) == BIT_NOT_EXPR)
11060 tree base = tsubst_copy (TREE_OPERAND (name, 0), args,
11061 complain, in_decl);
11062 name = TREE_OPERAND (name, 1);
11063 name = tsubst_copy (TREE_OPERAND (name, 0), args,
11064 complain, in_decl);
11065 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
11066 name = build_qualified_name (/*type=*/NULL_TREE,
11068 /*template_p=*/false);
11070 else if (TREE_CODE (name) == BASELINK)
11071 name = tsubst_baselink (name,
11072 non_reference (TREE_TYPE (object)),
11076 name = tsubst_copy (name, args, complain, in_decl);
11077 return build_nt (COMPONENT_REF, object, name, NULL_TREE);
11083 case TRUNC_DIV_EXPR:
11084 case CEIL_DIV_EXPR:
11085 case FLOOR_DIV_EXPR:
11086 case ROUND_DIV_EXPR:
11087 case EXACT_DIV_EXPR:
11091 case TRUNC_MOD_EXPR:
11092 case FLOOR_MOD_EXPR:
11093 case TRUTH_ANDIF_EXPR:
11094 case TRUTH_ORIF_EXPR:
11095 case TRUTH_AND_EXPR:
11096 case TRUTH_OR_EXPR:
11109 case COMPOUND_EXPR:
11112 case PREDECREMENT_EXPR:
11113 case PREINCREMENT_EXPR:
11114 case POSTDECREMENT_EXPR:
11115 case POSTINCREMENT_EXPR:
11117 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11118 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
11121 return build_qualified_name (/*type=*/NULL_TREE,
11122 tsubst_copy (TREE_OPERAND (t, 0),
11123 args, complain, in_decl),
11124 tsubst_copy (TREE_OPERAND (t, 1),
11125 args, complain, in_decl),
11126 QUALIFIED_NAME_IS_TEMPLATE (t));
11131 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11132 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
11133 NULL_TREE, NULL_TREE);
11137 int n = VL_EXP_OPERAND_LENGTH (t);
11138 tree result = build_vl_exp (CALL_EXPR, n);
11140 for (i = 0; i < n; i++)
11141 TREE_OPERAND (t, i) = tsubst_copy (TREE_OPERAND (t, i), args,
11142 complain, in_decl);
11148 case PSEUDO_DTOR_EXPR:
11151 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11152 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
11153 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
11154 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
11161 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11162 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
11163 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
11164 NEW_EXPR_USE_GLOBAL (r) = NEW_EXPR_USE_GLOBAL (t);
11171 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11172 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
11173 DELETE_EXPR_USE_GLOBAL (r) = DELETE_EXPR_USE_GLOBAL (t);
11174 DELETE_EXPR_USE_VEC (r) = DELETE_EXPR_USE_VEC (t);
11178 case TEMPLATE_ID_EXPR:
11180 /* Substituted template arguments */
11181 tree fn = TREE_OPERAND (t, 0);
11182 tree targs = TREE_OPERAND (t, 1);
11184 fn = tsubst_copy (fn, args, complain, in_decl);
11186 targs = tsubst_template_args (targs, args, complain, in_decl);
11188 return lookup_template_function (fn, targs);
11193 tree purpose, value, chain;
11195 if (t == void_list_node)
11198 purpose = TREE_PURPOSE (t);
11200 purpose = tsubst_copy (purpose, args, complain, in_decl);
11201 value = TREE_VALUE (t);
11203 value = tsubst_copy (value, args, complain, in_decl);
11204 chain = TREE_CHAIN (t);
11205 if (chain && chain != void_type_node)
11206 chain = tsubst_copy (chain, args, complain, in_decl);
11207 if (purpose == TREE_PURPOSE (t)
11208 && value == TREE_VALUE (t)
11209 && chain == TREE_CHAIN (t))
11211 return tree_cons (purpose, value, chain);
11216 case ENUMERAL_TYPE:
11218 case TEMPLATE_TYPE_PARM:
11219 case TEMPLATE_TEMPLATE_PARM:
11220 case BOUND_TEMPLATE_TEMPLATE_PARM:
11221 case TEMPLATE_PARM_INDEX:
11223 case REFERENCE_TYPE:
11225 case FUNCTION_TYPE:
11228 case TYPENAME_TYPE:
11229 case UNBOUND_CLASS_TEMPLATE:
11231 case DECLTYPE_TYPE:
11233 return tsubst (t, args, complain, in_decl);
11235 case IDENTIFIER_NODE:
11236 if (IDENTIFIER_TYPENAME_P (t))
11238 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
11239 return mangle_conv_op_name_for_type (new_type);
11245 /* This is handled by tsubst_copy_and_build. */
11246 gcc_unreachable ();
11249 return build_x_va_arg (tsubst_copy (TREE_OPERAND (t, 0), args, complain,
11251 tsubst (TREE_TYPE (t), args, complain, in_decl));
11253 case CLEANUP_POINT_EXPR:
11254 /* We shouldn't have built any of these during initial template
11255 generation. Instead, they should be built during instantiation
11256 in response to the saved STMT_IS_FULL_EXPR_P setting. */
11257 gcc_unreachable ();
11260 mark_used (TREE_OPERAND (t, 1));
11263 case EXPR_PACK_EXPANSION:
11264 error ("invalid use of pack expansion expression");
11265 return error_mark_node;
11267 case NONTYPE_ARGUMENT_PACK:
11268 error ("use %<...%> to expand argument pack");
11269 return error_mark_node;
11276 /* Like tsubst_copy, but specifically for OpenMP clauses. */
11279 tsubst_omp_clauses (tree clauses, tree args, tsubst_flags_t complain,
11282 tree new_clauses = NULL, nc, oc;
11284 for (oc = clauses; oc ; oc = OMP_CLAUSE_CHAIN (oc))
11286 nc = copy_node (oc);
11287 OMP_CLAUSE_CHAIN (nc) = new_clauses;
11290 switch (OMP_CLAUSE_CODE (nc))
11292 case OMP_CLAUSE_LASTPRIVATE:
11293 if (OMP_CLAUSE_LASTPRIVATE_STMT (oc))
11295 OMP_CLAUSE_LASTPRIVATE_STMT (nc) = push_stmt_list ();
11296 tsubst_expr (OMP_CLAUSE_LASTPRIVATE_STMT (oc), args, complain,
11297 in_decl, /*integral_constant_expression_p=*/false);
11298 OMP_CLAUSE_LASTPRIVATE_STMT (nc)
11299 = pop_stmt_list (OMP_CLAUSE_LASTPRIVATE_STMT (nc));
11302 case OMP_CLAUSE_PRIVATE:
11303 case OMP_CLAUSE_SHARED:
11304 case OMP_CLAUSE_FIRSTPRIVATE:
11305 case OMP_CLAUSE_REDUCTION:
11306 case OMP_CLAUSE_COPYIN:
11307 case OMP_CLAUSE_COPYPRIVATE:
11308 case OMP_CLAUSE_IF:
11309 case OMP_CLAUSE_NUM_THREADS:
11310 case OMP_CLAUSE_SCHEDULE:
11311 case OMP_CLAUSE_COLLAPSE:
11312 OMP_CLAUSE_OPERAND (nc, 0)
11313 = tsubst_expr (OMP_CLAUSE_OPERAND (oc, 0), args, complain,
11314 in_decl, /*integral_constant_expression_p=*/false);
11316 case OMP_CLAUSE_NOWAIT:
11317 case OMP_CLAUSE_ORDERED:
11318 case OMP_CLAUSE_DEFAULT:
11319 case OMP_CLAUSE_UNTIED:
11322 gcc_unreachable ();
11326 return finish_omp_clauses (nreverse (new_clauses));
11329 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
11332 tsubst_copy_asm_operands (tree t, tree args, tsubst_flags_t complain,
11335 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
11337 tree purpose, value, chain;
11342 if (TREE_CODE (t) != TREE_LIST)
11343 return tsubst_copy_and_build (t, args, complain, in_decl,
11344 /*function_p=*/false,
11345 /*integral_constant_expression_p=*/false);
11347 if (t == void_list_node)
11350 purpose = TREE_PURPOSE (t);
11352 purpose = RECUR (purpose);
11353 value = TREE_VALUE (t);
11354 if (value && TREE_CODE (value) != LABEL_DECL)
11355 value = RECUR (value);
11356 chain = TREE_CHAIN (t);
11357 if (chain && chain != void_type_node)
11358 chain = RECUR (chain);
11359 return tree_cons (purpose, value, chain);
11363 /* Substitute one OMP_FOR iterator. */
11366 tsubst_omp_for_iterator (tree t, int i, tree declv, tree initv,
11367 tree condv, tree incrv, tree *clauses,
11368 tree args, tsubst_flags_t complain, tree in_decl,
11369 bool integral_constant_expression_p)
11371 #define RECUR(NODE) \
11372 tsubst_expr ((NODE), args, complain, in_decl, \
11373 integral_constant_expression_p)
11374 tree decl, init, cond, incr, auto_node;
11376 init = TREE_VEC_ELT (OMP_FOR_INIT (t), i);
11377 gcc_assert (TREE_CODE (init) == MODIFY_EXPR);
11378 decl = RECUR (TREE_OPERAND (init, 0));
11379 init = TREE_OPERAND (init, 1);
11380 auto_node = type_uses_auto (TREE_TYPE (decl));
11381 if (auto_node && init)
11383 tree init_expr = init;
11384 if (TREE_CODE (init_expr) == DECL_EXPR)
11385 init_expr = DECL_INITIAL (DECL_EXPR_DECL (init_expr));
11386 init_expr = RECUR (init_expr);
11388 = do_auto_deduction (TREE_TYPE (decl), init_expr, auto_node);
11390 gcc_assert (!type_dependent_expression_p (decl));
11392 if (!CLASS_TYPE_P (TREE_TYPE (decl)))
11394 cond = RECUR (TREE_VEC_ELT (OMP_FOR_COND (t), i));
11395 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
11396 if (TREE_CODE (incr) == MODIFY_EXPR)
11397 incr = build_x_modify_expr (RECUR (TREE_OPERAND (incr, 0)), NOP_EXPR,
11398 RECUR (TREE_OPERAND (incr, 1)),
11401 incr = RECUR (incr);
11402 TREE_VEC_ELT (declv, i) = decl;
11403 TREE_VEC_ELT (initv, i) = init;
11404 TREE_VEC_ELT (condv, i) = cond;
11405 TREE_VEC_ELT (incrv, i) = incr;
11409 if (init && TREE_CODE (init) != DECL_EXPR)
11412 for (c = *clauses; c ; c = OMP_CLAUSE_CHAIN (c))
11414 if ((OMP_CLAUSE_CODE (c) == OMP_CLAUSE_PRIVATE
11415 || OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LASTPRIVATE)
11416 && OMP_CLAUSE_DECL (c) == decl)
11418 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_FIRSTPRIVATE
11419 && OMP_CLAUSE_DECL (c) == decl)
11420 error ("iteration variable %qD should not be firstprivate", decl);
11421 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_REDUCTION
11422 && OMP_CLAUSE_DECL (c) == decl)
11423 error ("iteration variable %qD should not be reduction", decl);
11427 c = build_omp_clause (input_location, OMP_CLAUSE_PRIVATE);
11428 OMP_CLAUSE_DECL (c) = decl;
11429 c = finish_omp_clauses (c);
11432 OMP_CLAUSE_CHAIN (c) = *clauses;
11437 cond = TREE_VEC_ELT (OMP_FOR_COND (t), i);
11438 if (COMPARISON_CLASS_P (cond))
11439 cond = build2 (TREE_CODE (cond), boolean_type_node,
11440 RECUR (TREE_OPERAND (cond, 0)),
11441 RECUR (TREE_OPERAND (cond, 1)));
11443 cond = RECUR (cond);
11444 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
11445 switch (TREE_CODE (incr))
11447 case PREINCREMENT_EXPR:
11448 case PREDECREMENT_EXPR:
11449 case POSTINCREMENT_EXPR:
11450 case POSTDECREMENT_EXPR:
11451 incr = build2 (TREE_CODE (incr), TREE_TYPE (decl),
11452 RECUR (TREE_OPERAND (incr, 0)), NULL_TREE);
11455 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
11456 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
11458 tree rhs = TREE_OPERAND (incr, 1);
11459 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
11460 RECUR (TREE_OPERAND (incr, 0)),
11461 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
11462 RECUR (TREE_OPERAND (rhs, 0)),
11463 RECUR (TREE_OPERAND (rhs, 1))));
11466 incr = RECUR (incr);
11469 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
11470 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
11472 tree lhs = RECUR (TREE_OPERAND (incr, 0));
11473 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl), lhs,
11474 build2 (TREE_CODE (TREE_OPERAND (incr, 1)),
11475 TREE_TYPE (decl), lhs,
11476 RECUR (TREE_OPERAND (incr, 2))));
11478 else if (TREE_CODE (TREE_OPERAND (incr, 1)) == NOP_EXPR
11479 && (TREE_CODE (TREE_OPERAND (incr, 2)) == PLUS_EXPR
11480 || (TREE_CODE (TREE_OPERAND (incr, 2)) == MINUS_EXPR)))
11482 tree rhs = TREE_OPERAND (incr, 2);
11483 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
11484 RECUR (TREE_OPERAND (incr, 0)),
11485 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
11486 RECUR (TREE_OPERAND (rhs, 0)),
11487 RECUR (TREE_OPERAND (rhs, 1))));
11490 incr = RECUR (incr);
11493 incr = RECUR (incr);
11497 TREE_VEC_ELT (declv, i) = decl;
11498 TREE_VEC_ELT (initv, i) = init;
11499 TREE_VEC_ELT (condv, i) = cond;
11500 TREE_VEC_ELT (incrv, i) = incr;
11504 /* Like tsubst_copy for expressions, etc. but also does semantic
11508 tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl,
11509 bool integral_constant_expression_p)
11511 #define RECUR(NODE) \
11512 tsubst_expr ((NODE), args, complain, in_decl, \
11513 integral_constant_expression_p)
11517 if (t == NULL_TREE || t == error_mark_node)
11520 if (EXPR_HAS_LOCATION (t))
11521 input_location = EXPR_LOCATION (t);
11522 if (STATEMENT_CODE_P (TREE_CODE (t)))
11523 current_stmt_tree ()->stmts_are_full_exprs_p = STMT_IS_FULL_EXPR_P (t);
11525 switch (TREE_CODE (t))
11527 case STATEMENT_LIST:
11529 tree_stmt_iterator i;
11530 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
11531 RECUR (tsi_stmt (i));
11535 case CTOR_INITIALIZER:
11536 finish_mem_initializers (tsubst_initializer_list
11537 (TREE_OPERAND (t, 0), args));
11541 finish_return_stmt (RECUR (TREE_OPERAND (t, 0)));
11545 tmp = RECUR (EXPR_STMT_EXPR (t));
11546 if (EXPR_STMT_STMT_EXPR_RESULT (t))
11547 finish_stmt_expr_expr (tmp, cur_stmt_expr);
11549 finish_expr_stmt (tmp);
11553 do_using_directive (RECUR (USING_STMT_NAMESPACE (t)));
11561 decl = DECL_EXPR_DECL (t);
11562 if (TREE_CODE (decl) == LABEL_DECL)
11563 finish_label_decl (DECL_NAME (decl));
11564 else if (TREE_CODE (decl) == USING_DECL)
11566 tree scope = USING_DECL_SCOPE (decl);
11567 tree name = DECL_NAME (decl);
11570 scope = RECUR (scope);
11571 decl = lookup_qualified_name (scope, name,
11572 /*is_type_p=*/false,
11573 /*complain=*/false);
11574 if (decl == error_mark_node || TREE_CODE (decl) == TREE_LIST)
11575 qualified_name_lookup_error (scope, name, decl, input_location);
11577 do_local_using_decl (decl, scope, name);
11581 init = DECL_INITIAL (decl);
11582 decl = tsubst (decl, args, complain, in_decl);
11583 if (decl != error_mark_node)
11585 /* By marking the declaration as instantiated, we avoid
11586 trying to instantiate it. Since instantiate_decl can't
11587 handle local variables, and since we've already done
11588 all that needs to be done, that's the right thing to
11590 if (TREE_CODE (decl) == VAR_DECL)
11591 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
11592 if (TREE_CODE (decl) == VAR_DECL
11593 && ANON_AGGR_TYPE_P (TREE_TYPE (decl)))
11594 /* Anonymous aggregates are a special case. */
11595 finish_anon_union (decl);
11598 maybe_push_decl (decl);
11599 if (TREE_CODE (decl) == VAR_DECL
11600 && DECL_PRETTY_FUNCTION_P (decl))
11602 /* For __PRETTY_FUNCTION__ we have to adjust the
11604 const char *const name
11605 = cxx_printable_name (current_function_decl, 2);
11606 init = cp_fname_init (name, &TREE_TYPE (decl));
11610 tree t = RECUR (init);
11613 /* If we had an initializer but it
11614 instantiated to nothing,
11615 value-initialize the object. This will
11616 only occur when the initializer was a
11617 pack expansion where the parameter packs
11618 used in that expansion were of length
11620 init = build_value_init (TREE_TYPE (decl));
11625 cp_finish_decl (decl, init, false, NULL_TREE, 0);
11630 /* A DECL_EXPR can also be used as an expression, in the condition
11631 clause of an if/for/while construct. */
11636 stmt = begin_for_stmt ();
11637 RECUR (FOR_INIT_STMT (t));
11638 finish_for_init_stmt (stmt);
11639 tmp = RECUR (FOR_COND (t));
11640 finish_for_cond (tmp, stmt);
11641 tmp = RECUR (FOR_EXPR (t));
11642 finish_for_expr (tmp, stmt);
11643 RECUR (FOR_BODY (t));
11644 finish_for_stmt (stmt);
11648 stmt = begin_while_stmt ();
11649 tmp = RECUR (WHILE_COND (t));
11650 finish_while_stmt_cond (tmp, stmt);
11651 RECUR (WHILE_BODY (t));
11652 finish_while_stmt (stmt);
11656 stmt = begin_do_stmt ();
11657 RECUR (DO_BODY (t));
11658 finish_do_body (stmt);
11659 tmp = RECUR (DO_COND (t));
11660 finish_do_stmt (tmp, stmt);
11664 stmt = begin_if_stmt ();
11665 tmp = RECUR (IF_COND (t));
11666 finish_if_stmt_cond (tmp, stmt);
11667 RECUR (THEN_CLAUSE (t));
11668 finish_then_clause (stmt);
11670 if (ELSE_CLAUSE (t))
11672 begin_else_clause (stmt);
11673 RECUR (ELSE_CLAUSE (t));
11674 finish_else_clause (stmt);
11677 finish_if_stmt (stmt);
11681 if (BIND_EXPR_BODY_BLOCK (t))
11682 stmt = begin_function_body ();
11684 stmt = begin_compound_stmt (BIND_EXPR_TRY_BLOCK (t)
11685 ? BCS_TRY_BLOCK : 0);
11687 RECUR (BIND_EXPR_BODY (t));
11689 if (BIND_EXPR_BODY_BLOCK (t))
11690 finish_function_body (stmt);
11692 finish_compound_stmt (stmt);
11696 finish_break_stmt ();
11699 case CONTINUE_STMT:
11700 finish_continue_stmt ();
11704 stmt = begin_switch_stmt ();
11705 tmp = RECUR (SWITCH_STMT_COND (t));
11706 finish_switch_cond (tmp, stmt);
11707 RECUR (SWITCH_STMT_BODY (t));
11708 finish_switch_stmt (stmt);
11711 case CASE_LABEL_EXPR:
11712 finish_case_label (EXPR_LOCATION (t),
11713 RECUR (CASE_LOW (t)),
11714 RECUR (CASE_HIGH (t)));
11719 tree decl = LABEL_EXPR_LABEL (t);
11722 label = finish_label_stmt (DECL_NAME (decl));
11723 if (DECL_ATTRIBUTES (decl) != NULL_TREE)
11724 cplus_decl_attributes (&label, DECL_ATTRIBUTES (decl), 0);
11729 tmp = GOTO_DESTINATION (t);
11730 if (TREE_CODE (tmp) != LABEL_DECL)
11731 /* Computed goto's must be tsubst'd into. On the other hand,
11732 non-computed gotos must not be; the identifier in question
11733 will have no binding. */
11736 tmp = DECL_NAME (tmp);
11737 finish_goto_stmt (tmp);
11741 tmp = finish_asm_stmt
11742 (ASM_VOLATILE_P (t),
11743 RECUR (ASM_STRING (t)),
11744 tsubst_copy_asm_operands (ASM_OUTPUTS (t), args, complain, in_decl),
11745 tsubst_copy_asm_operands (ASM_INPUTS (t), args, complain, in_decl),
11746 tsubst_copy_asm_operands (ASM_CLOBBERS (t), args, complain, in_decl),
11747 tsubst_copy_asm_operands (ASM_LABELS (t), args, complain, in_decl));
11749 tree asm_expr = tmp;
11750 if (TREE_CODE (asm_expr) == CLEANUP_POINT_EXPR)
11751 asm_expr = TREE_OPERAND (asm_expr, 0);
11752 ASM_INPUT_P (asm_expr) = ASM_INPUT_P (t);
11759 stmt = begin_try_block ();
11760 RECUR (TRY_STMTS (t));
11761 finish_cleanup_try_block (stmt);
11762 finish_cleanup (RECUR (TRY_HANDLERS (t)), stmt);
11766 tree compound_stmt = NULL_TREE;
11768 if (FN_TRY_BLOCK_P (t))
11769 stmt = begin_function_try_block (&compound_stmt);
11771 stmt = begin_try_block ();
11773 RECUR (TRY_STMTS (t));
11775 if (FN_TRY_BLOCK_P (t))
11776 finish_function_try_block (stmt);
11778 finish_try_block (stmt);
11780 RECUR (TRY_HANDLERS (t));
11781 if (FN_TRY_BLOCK_P (t))
11782 finish_function_handler_sequence (stmt, compound_stmt);
11784 finish_handler_sequence (stmt);
11790 tree decl = HANDLER_PARMS (t);
11794 decl = tsubst (decl, args, complain, in_decl);
11795 /* Prevent instantiate_decl from trying to instantiate
11796 this variable. We've already done all that needs to be
11798 if (decl != error_mark_node)
11799 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
11801 stmt = begin_handler ();
11802 finish_handler_parms (decl, stmt);
11803 RECUR (HANDLER_BODY (t));
11804 finish_handler (stmt);
11809 tsubst (TREE_TYPE (t), args, complain, NULL_TREE);
11812 case STATIC_ASSERT:
11815 tsubst_expr (STATIC_ASSERT_CONDITION (t),
11818 /*integral_constant_expression_p=*/true);
11819 finish_static_assert (condition,
11820 STATIC_ASSERT_MESSAGE (t),
11821 STATIC_ASSERT_SOURCE_LOCATION (t),
11822 /*member_p=*/false);
11827 tmp = tsubst_omp_clauses (OMP_PARALLEL_CLAUSES (t),
11828 args, complain, in_decl);
11829 stmt = begin_omp_parallel ();
11830 RECUR (OMP_PARALLEL_BODY (t));
11831 OMP_PARALLEL_COMBINED (finish_omp_parallel (tmp, stmt))
11832 = OMP_PARALLEL_COMBINED (t);
11836 tmp = tsubst_omp_clauses (OMP_TASK_CLAUSES (t),
11837 args, complain, in_decl);
11838 stmt = begin_omp_task ();
11839 RECUR (OMP_TASK_BODY (t));
11840 finish_omp_task (tmp, stmt);
11845 tree clauses, body, pre_body;
11846 tree declv, initv, condv, incrv;
11849 clauses = tsubst_omp_clauses (OMP_FOR_CLAUSES (t),
11850 args, complain, in_decl);
11851 declv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
11852 initv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
11853 condv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
11854 incrv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
11856 for (i = 0; i < TREE_VEC_LENGTH (OMP_FOR_INIT (t)); i++)
11857 tsubst_omp_for_iterator (t, i, declv, initv, condv, incrv,
11858 &clauses, args, complain, in_decl,
11859 integral_constant_expression_p);
11861 stmt = begin_omp_structured_block ();
11863 for (i = 0; i < TREE_VEC_LENGTH (initv); i++)
11864 if (TREE_VEC_ELT (initv, i) == NULL
11865 || TREE_CODE (TREE_VEC_ELT (initv, i)) != DECL_EXPR)
11866 TREE_VEC_ELT (initv, i) = RECUR (TREE_VEC_ELT (initv, i));
11867 else if (CLASS_TYPE_P (TREE_TYPE (TREE_VEC_ELT (initv, i))))
11869 tree init = RECUR (TREE_VEC_ELT (initv, i));
11870 gcc_assert (init == TREE_VEC_ELT (declv, i));
11871 TREE_VEC_ELT (initv, i) = NULL_TREE;
11875 tree decl_expr = TREE_VEC_ELT (initv, i);
11876 tree init = DECL_INITIAL (DECL_EXPR_DECL (decl_expr));
11877 gcc_assert (init != NULL);
11878 TREE_VEC_ELT (initv, i) = RECUR (init);
11879 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = NULL;
11881 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = init;
11884 pre_body = push_stmt_list ();
11885 RECUR (OMP_FOR_PRE_BODY (t));
11886 pre_body = pop_stmt_list (pre_body);
11888 body = push_stmt_list ();
11889 RECUR (OMP_FOR_BODY (t));
11890 body = pop_stmt_list (body);
11892 t = finish_omp_for (EXPR_LOCATION (t), declv, initv, condv, incrv,
11893 body, pre_body, clauses);
11895 add_stmt (finish_omp_structured_block (stmt));
11901 tmp = tsubst_omp_clauses (OMP_CLAUSES (t), args, complain, in_decl);
11902 stmt = push_stmt_list ();
11903 RECUR (OMP_BODY (t));
11904 stmt = pop_stmt_list (stmt);
11907 OMP_BODY (t) = stmt;
11908 OMP_CLAUSES (t) = tmp;
11916 stmt = push_stmt_list ();
11917 RECUR (OMP_BODY (t));
11918 stmt = pop_stmt_list (stmt);
11921 OMP_BODY (t) = stmt;
11926 gcc_assert (OMP_ATOMIC_DEPENDENT_P (t));
11928 tree op1 = TREE_OPERAND (t, 1);
11929 tree lhs = RECUR (TREE_OPERAND (op1, 0));
11930 tree rhs = RECUR (TREE_OPERAND (op1, 1));
11931 finish_omp_atomic (TREE_CODE (op1), lhs, rhs);
11935 case EXPR_PACK_EXPANSION:
11936 error ("invalid use of pack expansion expression");
11937 return error_mark_node;
11939 case NONTYPE_ARGUMENT_PACK:
11940 error ("use %<...%> to expand argument pack");
11941 return error_mark_node;
11944 gcc_assert (!STATEMENT_CODE_P (TREE_CODE (t)));
11946 return tsubst_copy_and_build (t, args, complain, in_decl,
11947 /*function_p=*/false,
11948 integral_constant_expression_p);
11955 /* T is a postfix-expression that is not being used in a function
11956 call. Return the substituted version of T. */
11959 tsubst_non_call_postfix_expression (tree t, tree args,
11960 tsubst_flags_t complain,
11963 if (TREE_CODE (t) == SCOPE_REF)
11964 t = tsubst_qualified_id (t, args, complain, in_decl,
11965 /*done=*/false, /*address_p=*/false);
11967 t = tsubst_copy_and_build (t, args, complain, in_decl,
11968 /*function_p=*/false,
11969 /*integral_constant_expression_p=*/false);
11974 /* Like tsubst but deals with expressions and performs semantic
11975 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
11978 tsubst_copy_and_build (tree t,
11980 tsubst_flags_t complain,
11983 bool integral_constant_expression_p)
11985 #define RECUR(NODE) \
11986 tsubst_copy_and_build (NODE, args, complain, in_decl, \
11987 /*function_p=*/false, \
11988 integral_constant_expression_p)
11992 if (t == NULL_TREE || t == error_mark_node)
11995 switch (TREE_CODE (t))
11999 /* Fall through. */
12000 case IDENTIFIER_NODE:
12004 bool non_integral_constant_expression_p;
12005 const char *error_msg;
12007 if (IDENTIFIER_TYPENAME_P (t))
12009 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12010 t = mangle_conv_op_name_for_type (new_type);
12013 /* Look up the name. */
12014 decl = lookup_name (t);
12016 /* By convention, expressions use ERROR_MARK_NODE to indicate
12017 failure, not NULL_TREE. */
12018 if (decl == NULL_TREE)
12019 decl = error_mark_node;
12021 decl = finish_id_expression (t, decl, NULL_TREE,
12023 integral_constant_expression_p,
12024 /*allow_non_integral_constant_expression_p=*/false,
12025 &non_integral_constant_expression_p,
12026 /*template_p=*/false,
12028 /*address_p=*/false,
12029 /*template_arg_p=*/false,
12034 if (!function_p && TREE_CODE (decl) == IDENTIFIER_NODE)
12035 decl = unqualified_name_lookup_error (decl);
12039 case TEMPLATE_ID_EXPR:
12042 tree templ = RECUR (TREE_OPERAND (t, 0));
12043 tree targs = TREE_OPERAND (t, 1);
12046 targs = tsubst_template_args (targs, args, complain, in_decl);
12048 if (TREE_CODE (templ) == COMPONENT_REF)
12050 object = TREE_OPERAND (templ, 0);
12051 templ = TREE_OPERAND (templ, 1);
12054 object = NULL_TREE;
12055 templ = lookup_template_function (templ, targs);
12058 return build3 (COMPONENT_REF, TREE_TYPE (templ),
12059 object, templ, NULL_TREE);
12061 return baselink_for_fns (templ);
12066 tree r = RECUR (TREE_OPERAND (t, 0));
12068 if (REFERENCE_REF_P (t))
12070 /* A type conversion to reference type will be enclosed in
12071 such an indirect ref, but the substitution of the cast
12072 will have also added such an indirect ref. */
12073 if (TREE_CODE (TREE_TYPE (r)) == REFERENCE_TYPE)
12074 r = convert_from_reference (r);
12077 r = build_x_indirect_ref (r, RO_UNARY_STAR, complain);
12083 (tsubst (TREE_TYPE (t), args, complain, in_decl),
12084 RECUR (TREE_OPERAND (t, 0)));
12087 case REINTERPRET_CAST_EXPR:
12088 case CONST_CAST_EXPR:
12089 case DYNAMIC_CAST_EXPR:
12090 case STATIC_CAST_EXPR:
12095 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12096 if (integral_constant_expression_p
12097 && !cast_valid_in_integral_constant_expression_p (type))
12099 if (complain & tf_error)
12100 error ("a cast to a type other than an integral or "
12101 "enumeration type cannot appear in a constant-expression");
12102 return error_mark_node;
12105 op = RECUR (TREE_OPERAND (t, 0));
12107 switch (TREE_CODE (t))
12110 return build_functional_cast (type, op, complain);
12111 case REINTERPRET_CAST_EXPR:
12112 return build_reinterpret_cast (type, op, complain);
12113 case CONST_CAST_EXPR:
12114 return build_const_cast (type, op, complain);
12115 case DYNAMIC_CAST_EXPR:
12116 return build_dynamic_cast (type, op, complain);
12117 case STATIC_CAST_EXPR:
12118 return build_static_cast (type, op, complain);
12120 gcc_unreachable ();
12124 case POSTDECREMENT_EXPR:
12125 case POSTINCREMENT_EXPR:
12126 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
12127 args, complain, in_decl);
12128 return build_x_unary_op (TREE_CODE (t), op1, complain);
12130 case PREDECREMENT_EXPR:
12131 case PREINCREMENT_EXPR:
12135 case TRUTH_NOT_EXPR:
12136 case UNARY_PLUS_EXPR: /* Unary + */
12137 case REALPART_EXPR:
12138 case IMAGPART_EXPR:
12139 return build_x_unary_op (TREE_CODE (t), RECUR (TREE_OPERAND (t, 0)),
12143 op1 = TREE_OPERAND (t, 0);
12144 if (TREE_CODE (op1) == SCOPE_REF)
12145 op1 = tsubst_qualified_id (op1, args, complain, in_decl,
12146 /*done=*/true, /*address_p=*/true);
12148 op1 = tsubst_non_call_postfix_expression (op1, args, complain,
12150 if (TREE_CODE (op1) == LABEL_DECL)
12151 return finish_label_address_expr (DECL_NAME (op1),
12152 EXPR_LOCATION (op1));
12153 return build_x_unary_op (ADDR_EXPR, op1, complain);
12158 case TRUNC_DIV_EXPR:
12159 case CEIL_DIV_EXPR:
12160 case FLOOR_DIV_EXPR:
12161 case ROUND_DIV_EXPR:
12162 case EXACT_DIV_EXPR:
12166 case TRUNC_MOD_EXPR:
12167 case FLOOR_MOD_EXPR:
12168 case TRUTH_ANDIF_EXPR:
12169 case TRUTH_ORIF_EXPR:
12170 case TRUTH_AND_EXPR:
12171 case TRUTH_OR_EXPR:
12186 return build_x_binary_op
12188 RECUR (TREE_OPERAND (t, 0)),
12189 (TREE_NO_WARNING (TREE_OPERAND (t, 0))
12191 : TREE_CODE (TREE_OPERAND (t, 0))),
12192 RECUR (TREE_OPERAND (t, 1)),
12193 (TREE_NO_WARNING (TREE_OPERAND (t, 1))
12195 : TREE_CODE (TREE_OPERAND (t, 1))),
12196 /*overloaded_p=*/NULL,
12200 return tsubst_qualified_id (t, args, complain, in_decl, /*done=*/true,
12201 /*address_p=*/false);
12203 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
12204 args, complain, in_decl);
12205 return build_x_array_ref (op1, RECUR (TREE_OPERAND (t, 1)), complain);
12208 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
12209 return tsubst_copy (t, args, complain, in_decl);
12213 op1 = TREE_OPERAND (t, 0);
12216 /* When there are no ARGS, we are trying to evaluate a
12217 non-dependent expression from the parser. Trying to do
12218 the substitutions may not work. */
12220 op1 = TREE_TYPE (op1);
12224 ++cp_unevaluated_operand;
12225 ++c_inhibit_evaluation_warnings;
12226 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
12227 /*function_p=*/false,
12228 /*integral_constant_expression_p=*/false);
12229 --cp_unevaluated_operand;
12230 --c_inhibit_evaluation_warnings;
12233 return cxx_sizeof_or_alignof_type (op1, TREE_CODE (t),
12234 complain & tf_error);
12236 return cxx_sizeof_or_alignof_expr (op1, TREE_CODE (t),
12237 complain & tf_error);
12241 tree r = build_x_modify_expr
12242 (RECUR (TREE_OPERAND (t, 0)),
12243 TREE_CODE (TREE_OPERAND (t, 1)),
12244 RECUR (TREE_OPERAND (t, 2)),
12246 /* TREE_NO_WARNING must be set if either the expression was
12247 parenthesized or it uses an operator such as >>= rather
12248 than plain assignment. In the former case, it was already
12249 set and must be copied. In the latter case,
12250 build_x_modify_expr sets it and it must not be reset
12252 if (TREE_NO_WARNING (t))
12253 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
12258 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
12259 args, complain, in_decl);
12260 /* Remember that there was a reference to this entity. */
12263 return build_x_arrow (op1);
12267 tree placement = RECUR (TREE_OPERAND (t, 0));
12268 tree init = RECUR (TREE_OPERAND (t, 3));
12269 VEC(tree,gc) *placement_vec;
12270 VEC(tree,gc) *init_vec;
12273 if (placement == NULL_TREE)
12274 placement_vec = NULL;
12277 placement_vec = make_tree_vector ();
12278 for (; placement != NULL_TREE; placement = TREE_CHAIN (placement))
12279 VEC_safe_push (tree, gc, placement_vec, TREE_VALUE (placement));
12282 /* If there was an initializer in the original tree, but it
12283 instantiated to an empty list, then we should pass a
12284 non-NULL empty vector to tell build_new that it was an
12285 empty initializer() rather than no initializer. This can
12286 only happen when the initializer is a pack expansion whose
12287 parameter packs are of length zero. */
12288 if (init == NULL_TREE && TREE_OPERAND (t, 3) == NULL_TREE)
12292 init_vec = make_tree_vector ();
12293 if (init == void_zero_node)
12294 gcc_assert (init_vec != NULL);
12297 for (; init != NULL_TREE; init = TREE_CHAIN (init))
12298 VEC_safe_push (tree, gc, init_vec, TREE_VALUE (init));
12302 ret = build_new (&placement_vec,
12303 RECUR (TREE_OPERAND (t, 1)),
12304 RECUR (TREE_OPERAND (t, 2)),
12306 NEW_EXPR_USE_GLOBAL (t),
12309 if (placement_vec != NULL)
12310 release_tree_vector (placement_vec);
12311 if (init_vec != NULL)
12312 release_tree_vector (init_vec);
12318 return delete_sanity
12319 (RECUR (TREE_OPERAND (t, 0)),
12320 RECUR (TREE_OPERAND (t, 1)),
12321 DELETE_EXPR_USE_VEC (t),
12322 DELETE_EXPR_USE_GLOBAL (t));
12324 case COMPOUND_EXPR:
12325 return build_x_compound_expr (RECUR (TREE_OPERAND (t, 0)),
12326 RECUR (TREE_OPERAND (t, 1)),
12332 VEC(tree,gc) *call_args;
12333 unsigned int nargs, i;
12338 function = CALL_EXPR_FN (t);
12339 /* When we parsed the expression, we determined whether or
12340 not Koenig lookup should be performed. */
12341 koenig_p = KOENIG_LOOKUP_P (t);
12342 if (TREE_CODE (function) == SCOPE_REF)
12344 qualified_p = true;
12345 function = tsubst_qualified_id (function, args, complain, in_decl,
12347 /*address_p=*/false);
12351 if (TREE_CODE (function) == COMPONENT_REF)
12353 tree op = TREE_OPERAND (function, 1);
12355 qualified_p = (TREE_CODE (op) == SCOPE_REF
12356 || (BASELINK_P (op)
12357 && BASELINK_QUALIFIED_P (op)));
12360 qualified_p = false;
12362 function = tsubst_copy_and_build (function, args, complain,
12365 integral_constant_expression_p);
12367 if (BASELINK_P (function))
12368 qualified_p = true;
12371 nargs = call_expr_nargs (t);
12372 call_args = make_tree_vector ();
12373 for (i = 0; i < nargs; ++i)
12375 tree arg = CALL_EXPR_ARG (t, i);
12377 if (!PACK_EXPANSION_P (arg))
12378 VEC_safe_push (tree, gc, call_args,
12379 RECUR (CALL_EXPR_ARG (t, i)));
12382 /* Expand the pack expansion and push each entry onto
12384 arg = tsubst_pack_expansion (arg, args, complain, in_decl);
12385 if (TREE_CODE (arg) == TREE_VEC)
12387 unsigned int len, j;
12389 len = TREE_VEC_LENGTH (arg);
12390 for (j = 0; j < len; ++j)
12392 tree value = TREE_VEC_ELT (arg, j);
12393 if (value != NULL_TREE)
12394 value = convert_from_reference (value);
12395 VEC_safe_push (tree, gc, call_args, value);
12400 /* A partial substitution. Add one entry. */
12401 VEC_safe_push (tree, gc, call_args, arg);
12406 /* We do not perform argument-dependent lookup if normal
12407 lookup finds a non-function, in accordance with the
12408 expected resolution of DR 218. */
12410 && ((is_overloaded_fn (function)
12411 /* If lookup found a member function, the Koenig lookup is
12412 not appropriate, even if an unqualified-name was used
12413 to denote the function. */
12414 && !DECL_FUNCTION_MEMBER_P (get_first_fn (function)))
12415 || TREE_CODE (function) == IDENTIFIER_NODE)
12416 /* Only do this when substitution turns a dependent call
12417 into a non-dependent call. */
12418 && type_dependent_expression_p_push (t)
12419 && !any_type_dependent_arguments_p (call_args))
12420 function = perform_koenig_lookup (function, call_args);
12422 if (TREE_CODE (function) == IDENTIFIER_NODE)
12424 unqualified_name_lookup_error (function);
12425 release_tree_vector (call_args);
12426 return error_mark_node;
12429 /* Remember that there was a reference to this entity. */
12430 if (DECL_P (function))
12431 mark_used (function);
12433 if (TREE_CODE (function) == OFFSET_REF)
12434 ret = build_offset_ref_call_from_tree (function, &call_args);
12435 else if (TREE_CODE (function) == COMPONENT_REF)
12437 if (!BASELINK_P (TREE_OPERAND (function, 1)))
12438 ret = finish_call_expr (function, &call_args,
12439 /*disallow_virtual=*/false,
12440 /*koenig_p=*/false,
12443 ret = (build_new_method_call
12444 (TREE_OPERAND (function, 0),
12445 TREE_OPERAND (function, 1),
12446 &call_args, NULL_TREE,
12447 qualified_p ? LOOKUP_NONVIRTUAL : LOOKUP_NORMAL,
12452 ret = finish_call_expr (function, &call_args,
12453 /*disallow_virtual=*/qualified_p,
12457 release_tree_vector (call_args);
12463 return build_x_conditional_expr
12464 (RECUR (TREE_OPERAND (t, 0)),
12465 RECUR (TREE_OPERAND (t, 1)),
12466 RECUR (TREE_OPERAND (t, 2)),
12469 case PSEUDO_DTOR_EXPR:
12470 return finish_pseudo_destructor_expr
12471 (RECUR (TREE_OPERAND (t, 0)),
12472 RECUR (TREE_OPERAND (t, 1)),
12473 RECUR (TREE_OPERAND (t, 2)));
12477 tree purpose, value, chain;
12479 if (t == void_list_node)
12482 if ((TREE_PURPOSE (t) && PACK_EXPANSION_P (TREE_PURPOSE (t)))
12483 || (TREE_VALUE (t) && PACK_EXPANSION_P (TREE_VALUE (t))))
12485 /* We have pack expansions, so expand those and
12486 create a new list out of it. */
12487 tree purposevec = NULL_TREE;
12488 tree valuevec = NULL_TREE;
12492 /* Expand the argument expressions. */
12493 if (TREE_PURPOSE (t))
12494 purposevec = tsubst_pack_expansion (TREE_PURPOSE (t), args,
12495 complain, in_decl);
12496 if (TREE_VALUE (t))
12497 valuevec = tsubst_pack_expansion (TREE_VALUE (t), args,
12498 complain, in_decl);
12500 /* Build the rest of the list. */
12501 chain = TREE_CHAIN (t);
12502 if (chain && chain != void_type_node)
12503 chain = RECUR (chain);
12505 /* Determine the number of arguments. */
12506 if (purposevec && TREE_CODE (purposevec) == TREE_VEC)
12508 len = TREE_VEC_LENGTH (purposevec);
12509 gcc_assert (!valuevec || len == TREE_VEC_LENGTH (valuevec));
12511 else if (TREE_CODE (valuevec) == TREE_VEC)
12512 len = TREE_VEC_LENGTH (valuevec);
12515 /* Since we only performed a partial substitution into
12516 the argument pack, we only return a single list
12518 if (purposevec == TREE_PURPOSE (t)
12519 && valuevec == TREE_VALUE (t)
12520 && chain == TREE_CHAIN (t))
12523 return tree_cons (purposevec, valuevec, chain);
12526 /* Convert the argument vectors into a TREE_LIST */
12530 /* Grab the Ith values. */
12532 purpose = purposevec ? TREE_VEC_ELT (purposevec, i)
12535 = valuevec ? convert_from_reference (TREE_VEC_ELT (valuevec, i))
12538 /* Build the list (backwards). */
12539 chain = tree_cons (purpose, value, chain);
12545 purpose = TREE_PURPOSE (t);
12547 purpose = RECUR (purpose);
12548 value = TREE_VALUE (t);
12550 value = RECUR (value);
12551 chain = TREE_CHAIN (t);
12552 if (chain && chain != void_type_node)
12553 chain = RECUR (chain);
12554 if (purpose == TREE_PURPOSE (t)
12555 && value == TREE_VALUE (t)
12556 && chain == TREE_CHAIN (t))
12558 return tree_cons (purpose, value, chain);
12561 case COMPONENT_REF:
12567 object = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
12568 args, complain, in_decl);
12569 /* Remember that there was a reference to this entity. */
12570 if (DECL_P (object))
12571 mark_used (object);
12572 object_type = TREE_TYPE (object);
12574 member = TREE_OPERAND (t, 1);
12575 if (BASELINK_P (member))
12576 member = tsubst_baselink (member,
12577 non_reference (TREE_TYPE (object)),
12578 args, complain, in_decl);
12580 member = tsubst_copy (member, args, complain, in_decl);
12581 if (member == error_mark_node)
12582 return error_mark_node;
12584 if (object_type && !CLASS_TYPE_P (object_type))
12586 if (SCALAR_TYPE_P (object_type))
12588 tree s = NULL_TREE;
12589 tree dtor = member;
12591 if (TREE_CODE (dtor) == SCOPE_REF)
12593 s = TREE_OPERAND (dtor, 0);
12594 dtor = TREE_OPERAND (dtor, 1);
12596 if (TREE_CODE (dtor) == BIT_NOT_EXPR)
12598 dtor = TREE_OPERAND (dtor, 0);
12600 return finish_pseudo_destructor_expr (object, s, dtor);
12604 else if (TREE_CODE (member) == SCOPE_REF
12605 && TREE_CODE (TREE_OPERAND (member, 1)) == TEMPLATE_ID_EXPR)
12610 /* Lookup the template functions now that we know what the
12612 tmpl = TREE_OPERAND (TREE_OPERAND (member, 1), 0);
12613 args = TREE_OPERAND (TREE_OPERAND (member, 1), 1);
12614 member = lookup_qualified_name (TREE_OPERAND (member, 0), tmpl,
12615 /*is_type_p=*/false,
12616 /*complain=*/false);
12617 if (BASELINK_P (member))
12619 BASELINK_FUNCTIONS (member)
12620 = build_nt (TEMPLATE_ID_EXPR, BASELINK_FUNCTIONS (member),
12622 member = (adjust_result_of_qualified_name_lookup
12623 (member, BINFO_TYPE (BASELINK_BINFO (member)),
12628 qualified_name_lookup_error (object_type, tmpl, member,
12630 return error_mark_node;
12633 else if (TREE_CODE (member) == SCOPE_REF
12634 && !CLASS_TYPE_P (TREE_OPERAND (member, 0))
12635 && TREE_CODE (TREE_OPERAND (member, 0)) != NAMESPACE_DECL)
12637 if (complain & tf_error)
12639 if (TYPE_P (TREE_OPERAND (member, 0)))
12640 error ("%qT is not a class or namespace",
12641 TREE_OPERAND (member, 0));
12643 error ("%qD is not a class or namespace",
12644 TREE_OPERAND (member, 0));
12646 return error_mark_node;
12648 else if (TREE_CODE (member) == FIELD_DECL)
12649 return finish_non_static_data_member (member, object, NULL_TREE);
12651 return finish_class_member_access_expr (object, member,
12652 /*template_p=*/false,
12658 (RECUR (TREE_OPERAND (t, 0)));
12662 VEC(constructor_elt,gc) *n;
12663 constructor_elt *ce;
12664 unsigned HOST_WIDE_INT idx;
12665 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12666 bool process_index_p;
12668 bool need_copy_p = false;
12671 if (type == error_mark_node)
12672 return error_mark_node;
12674 /* digest_init will do the wrong thing if we let it. */
12675 if (type && TYPE_PTRMEMFUNC_P (type))
12678 /* We do not want to process the index of aggregate
12679 initializers as they are identifier nodes which will be
12680 looked up by digest_init. */
12681 process_index_p = !(type && MAYBE_CLASS_TYPE_P (type));
12683 n = VEC_copy (constructor_elt, gc, CONSTRUCTOR_ELTS (t));
12684 newlen = VEC_length (constructor_elt, n);
12685 for (idx = 0; VEC_iterate (constructor_elt, n, idx, ce); idx++)
12687 if (ce->index && process_index_p)
12688 ce->index = RECUR (ce->index);
12690 if (PACK_EXPANSION_P (ce->value))
12692 /* Substitute into the pack expansion. */
12693 ce->value = tsubst_pack_expansion (ce->value, args, complain,
12696 if (ce->value == error_mark_node)
12698 else if (TREE_VEC_LENGTH (ce->value) == 1)
12699 /* Just move the argument into place. */
12700 ce->value = TREE_VEC_ELT (ce->value, 0);
12703 /* Update the length of the final CONSTRUCTOR
12704 arguments vector, and note that we will need to
12706 newlen = newlen + TREE_VEC_LENGTH (ce->value) - 1;
12707 need_copy_p = true;
12711 ce->value = RECUR (ce->value);
12716 VEC(constructor_elt,gc) *old_n = n;
12718 n = VEC_alloc (constructor_elt, gc, newlen);
12719 for (idx = 0; VEC_iterate (constructor_elt, old_n, idx, ce);
12722 if (TREE_CODE (ce->value) == TREE_VEC)
12724 int i, len = TREE_VEC_LENGTH (ce->value);
12725 for (i = 0; i < len; ++i)
12726 CONSTRUCTOR_APPEND_ELT (n, 0,
12727 TREE_VEC_ELT (ce->value, i));
12730 CONSTRUCTOR_APPEND_ELT (n, 0, ce->value);
12734 r = build_constructor (init_list_type_node, n);
12735 CONSTRUCTOR_IS_DIRECT_INIT (r) = CONSTRUCTOR_IS_DIRECT_INIT (t);
12737 if (TREE_HAS_CONSTRUCTOR (t))
12738 return finish_compound_literal (type, r);
12745 tree operand_0 = RECUR (TREE_OPERAND (t, 0));
12746 if (TYPE_P (operand_0))
12747 return get_typeid (operand_0);
12748 return build_typeid (operand_0);
12758 tree r = tsubst_copy (t, args, complain, in_decl);
12760 if (TREE_CODE (TREE_TYPE (t)) != REFERENCE_TYPE)
12761 /* If the original type was a reference, we'll be wrapped in
12762 the appropriate INDIRECT_REF. */
12763 r = convert_from_reference (r);
12768 return build_x_va_arg (RECUR (TREE_OPERAND (t, 0)),
12769 tsubst_copy (TREE_TYPE (t), args, complain,
12772 case OFFSETOF_EXPR:
12773 return finish_offsetof (RECUR (TREE_OPERAND (t, 0)));
12777 tree type1 = tsubst_copy (TRAIT_EXPR_TYPE1 (t), args,
12778 complain, in_decl);
12780 tree type2 = TRAIT_EXPR_TYPE2 (t);
12782 type2 = tsubst_copy (type2, args, complain, in_decl);
12784 return finish_trait_expr (TRAIT_EXPR_KIND (t), type1, type2);
12789 tree old_stmt_expr = cur_stmt_expr;
12790 tree stmt_expr = begin_stmt_expr ();
12792 cur_stmt_expr = stmt_expr;
12793 tsubst_expr (STMT_EXPR_STMT (t), args, complain, in_decl,
12794 integral_constant_expression_p);
12795 stmt_expr = finish_stmt_expr (stmt_expr, false);
12796 cur_stmt_expr = old_stmt_expr;
12798 /* If the resulting list of expression statement is empty,
12799 fold it further into void_zero_node. */
12800 if (empty_expr_stmt_p (stmt_expr))
12801 stmt_expr = void_zero_node;
12807 t = tsubst_copy (t, args, complain, in_decl);
12808 /* As in finish_id_expression, we resolve enumeration constants
12809 to their underlying values. */
12810 if (TREE_CODE (t) == CONST_DECL)
12812 used_types_insert (TREE_TYPE (t));
12813 return DECL_INITIAL (t);
12819 tree r = build_lambda_expr ();
12821 tree type = tsubst (TREE_TYPE (t), args, complain, NULL_TREE);
12822 TREE_TYPE (r) = type;
12823 CLASSTYPE_LAMBDA_EXPR (type) = r;
12825 LAMBDA_EXPR_LOCATION (r)
12826 = LAMBDA_EXPR_LOCATION (t);
12827 LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (r)
12828 = LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (t);
12829 LAMBDA_EXPR_MUTABLE_P (r) = LAMBDA_EXPR_MUTABLE_P (t);
12830 LAMBDA_EXPR_DISCRIMINATOR (r)
12831 = (LAMBDA_EXPR_DISCRIMINATOR (t));
12832 LAMBDA_EXPR_CAPTURE_LIST (r)
12833 = RECUR (LAMBDA_EXPR_CAPTURE_LIST (t));
12834 LAMBDA_EXPR_THIS_CAPTURE (r)
12835 = RECUR (LAMBDA_EXPR_THIS_CAPTURE (t));
12836 LAMBDA_EXPR_EXTRA_SCOPE (r)
12837 = RECUR (LAMBDA_EXPR_EXTRA_SCOPE (t));
12839 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
12840 determine_visibility (TYPE_NAME (type));
12841 /* Now that we know visibility, instantiate the type so we have a
12842 declaration of the op() for later calls to lambda_function. */
12843 complete_type (type);
12845 type = tsubst (LAMBDA_EXPR_RETURN_TYPE (t), args, complain, in_decl);
12847 apply_lambda_return_type (r, type);
12849 return build_lambda_object (r);
12853 /* Handle Objective-C++ constructs, if appropriate. */
12856 = objcp_tsubst_copy_and_build (t, args, complain,
12857 in_decl, /*function_p=*/false);
12861 return tsubst_copy (t, args, complain, in_decl);
12867 /* Verify that the instantiated ARGS are valid. For type arguments,
12868 make sure that the type's linkage is ok. For non-type arguments,
12869 make sure they are constants if they are integral or enumerations.
12870 Emit an error under control of COMPLAIN, and return TRUE on error. */
12873 check_instantiated_arg (tree tmpl, tree t, tsubst_flags_t complain)
12875 if (ARGUMENT_PACK_P (t))
12877 tree vec = ARGUMENT_PACK_ARGS (t);
12878 int len = TREE_VEC_LENGTH (vec);
12879 bool result = false;
12882 for (i = 0; i < len; ++i)
12883 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (vec, i), complain))
12887 else if (TYPE_P (t))
12889 /* [basic.link]: A name with no linkage (notably, the name
12890 of a class or enumeration declared in a local scope)
12891 shall not be used to declare an entity with linkage.
12892 This implies that names with no linkage cannot be used as
12895 DR 757 relaxes this restriction for C++0x. */
12896 tree nt = (cxx_dialect > cxx98 ? NULL_TREE
12897 : no_linkage_check (t, /*relaxed_p=*/false));
12901 /* DR 488 makes use of a type with no linkage cause
12902 type deduction to fail. */
12903 if (complain & tf_error)
12905 if (TYPE_ANONYMOUS_P (nt))
12906 error ("%qT is/uses anonymous type", t);
12908 error ("template argument for %qD uses local type %qT",
12913 /* In order to avoid all sorts of complications, we do not
12914 allow variably-modified types as template arguments. */
12915 else if (variably_modified_type_p (t, NULL_TREE))
12917 if (complain & tf_error)
12918 error ("%qT is a variably modified type", t);
12922 /* A non-type argument of integral or enumerated type must be a
12924 else if (TREE_TYPE (t)
12925 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t))
12926 && !TREE_CONSTANT (t))
12928 if (complain & tf_error)
12929 error ("integral expression %qE is not constant", t);
12936 check_instantiated_args (tree tmpl, tree args, tsubst_flags_t complain)
12938 int ix, len = DECL_NTPARMS (tmpl);
12939 bool result = false;
12941 for (ix = 0; ix != len; ix++)
12943 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (args, ix), complain))
12946 if (result && (complain & tf_error))
12947 error (" trying to instantiate %qD", tmpl);
12951 /* Instantiate the indicated variable or function template TMPL with
12952 the template arguments in TARG_PTR. */
12955 instantiate_template (tree tmpl, tree orig_args, tsubst_flags_t complain)
12957 tree targ_ptr = orig_args;
12961 HOST_WIDE_INT saved_processing_template_decl;
12963 if (tmpl == error_mark_node)
12964 return error_mark_node;
12966 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
12968 /* If this function is a clone, handle it specially. */
12969 if (DECL_CLONED_FUNCTION_P (tmpl))
12974 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
12975 DECL_CLONED_FUNCTION. */
12976 spec = instantiate_template (DECL_ABSTRACT_ORIGIN (tmpl),
12977 targ_ptr, complain);
12978 if (spec == error_mark_node)
12979 return error_mark_node;
12981 /* Look for the clone. */
12982 FOR_EACH_CLONE (clone, spec)
12983 if (DECL_NAME (clone) == DECL_NAME (tmpl))
12985 /* We should always have found the clone by now. */
12986 gcc_unreachable ();
12990 /* Check to see if we already have this specialization. */
12991 gen_tmpl = most_general_template (tmpl);
12992 if (tmpl != gen_tmpl)
12993 /* The TMPL is a partial instantiation. To get a full set of
12994 arguments we must add the arguments used to perform the
12995 partial instantiation. */
12996 targ_ptr = add_outermost_template_args (DECL_TI_ARGS (tmpl),
12999 /* It would be nice to avoid hashing here and then again in tsubst_decl,
13000 but it doesn't seem to be on the hot path. */
13001 spec = retrieve_specialization (gen_tmpl, targ_ptr, 0);
13003 gcc_assert (tmpl == gen_tmpl
13004 || ((fndecl = retrieve_specialization (tmpl, orig_args, 0))
13006 || fndecl == NULL_TREE);
13008 if (spec != NULL_TREE)
13011 if (check_instantiated_args (gen_tmpl, INNERMOST_TEMPLATE_ARGS (targ_ptr),
13013 return error_mark_node;
13015 /* We are building a FUNCTION_DECL, during which the access of its
13016 parameters and return types have to be checked. However this
13017 FUNCTION_DECL which is the desired context for access checking
13018 is not built yet. We solve this chicken-and-egg problem by
13019 deferring all checks until we have the FUNCTION_DECL. */
13020 push_deferring_access_checks (dk_deferred);
13022 /* Although PROCESSING_TEMPLATE_DECL may be true at this point
13023 (because, for example, we have encountered a non-dependent
13024 function call in the body of a template function and must now
13025 determine which of several overloaded functions will be called),
13026 within the instantiation itself we are not processing a
13028 saved_processing_template_decl = processing_template_decl;
13029 processing_template_decl = 0;
13030 /* Substitute template parameters to obtain the specialization. */
13031 fndecl = tsubst (DECL_TEMPLATE_RESULT (gen_tmpl),
13032 targ_ptr, complain, gen_tmpl);
13033 processing_template_decl = saved_processing_template_decl;
13034 if (fndecl == error_mark_node)
13035 return error_mark_node;
13037 /* Now we know the specialization, compute access previously
13039 push_access_scope (fndecl);
13041 /* Some typedefs referenced from within the template code need to be access
13042 checked at template instantiation time, i.e now. These types were
13043 added to the template at parsing time. Let's get those and perfom
13044 the acces checks then. */
13045 perform_typedefs_access_check (DECL_TEMPLATE_RESULT (tmpl), targ_ptr);
13046 perform_deferred_access_checks ();
13047 pop_access_scope (fndecl);
13048 pop_deferring_access_checks ();
13050 /* The DECL_TI_TEMPLATE should always be the immediate parent
13051 template, not the most general template. */
13052 DECL_TI_TEMPLATE (fndecl) = tmpl;
13054 /* If we've just instantiated the main entry point for a function,
13055 instantiate all the alternate entry points as well. We do this
13056 by cloning the instantiation of the main entry point, not by
13057 instantiating the template clones. */
13058 if (TREE_CHAIN (gen_tmpl) && DECL_CLONED_FUNCTION_P (TREE_CHAIN (gen_tmpl)))
13059 clone_function_decl (fndecl, /*update_method_vec_p=*/0);
13064 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
13065 NARGS elements of the arguments that are being used when calling
13066 it. TARGS is a vector into which the deduced template arguments
13069 Return zero for success, 2 for an incomplete match that doesn't resolve
13070 all the types, and 1 for complete failure. An error message will be
13071 printed only for an incomplete match.
13073 If FN is a conversion operator, or we are trying to produce a specific
13074 specialization, RETURN_TYPE is the return type desired.
13076 The EXPLICIT_TARGS are explicit template arguments provided via a
13079 The parameter STRICT is one of:
13082 We are deducing arguments for a function call, as in
13083 [temp.deduct.call].
13086 We are deducing arguments for a conversion function, as in
13087 [temp.deduct.conv].
13090 We are deducing arguments when doing an explicit instantiation
13091 as in [temp.explicit], when determining an explicit specialization
13092 as in [temp.expl.spec], or when taking the address of a function
13093 template, as in [temp.deduct.funcaddr]. */
13096 fn_type_unification (tree fn,
13097 tree explicit_targs,
13100 unsigned int nargs,
13102 unification_kind_t strict,
13108 bool incomplete_argument_packs_p = false;
13110 gcc_assert (TREE_CODE (fn) == TEMPLATE_DECL);
13112 fntype = TREE_TYPE (fn);
13113 if (explicit_targs)
13117 The specified template arguments must match the template
13118 parameters in kind (i.e., type, nontype, template), and there
13119 must not be more arguments than there are parameters;
13120 otherwise type deduction fails.
13122 Nontype arguments must match the types of the corresponding
13123 nontype template parameters, or must be convertible to the
13124 types of the corresponding nontype parameters as specified in
13125 _temp.arg.nontype_, otherwise type deduction fails.
13127 All references in the function type of the function template
13128 to the corresponding template parameters are replaced by the
13129 specified template argument values. If a substitution in a
13130 template parameter or in the function type of the function
13131 template results in an invalid type, type deduction fails. */
13132 tree tparms = DECL_INNERMOST_TEMPLATE_PARMS (fn);
13133 int i, len = TREE_VEC_LENGTH (tparms);
13134 tree converted_args;
13135 bool incomplete = false;
13137 if (explicit_targs == error_mark_node)
13141 = (coerce_template_parms (tparms, explicit_targs, NULL_TREE, tf_none,
13142 /*require_all_args=*/false,
13143 /*use_default_args=*/false));
13144 if (converted_args == error_mark_node)
13147 /* Substitute the explicit args into the function type. This is
13148 necessary so that, for instance, explicitly declared function
13149 arguments can match null pointed constants. If we were given
13150 an incomplete set of explicit args, we must not do semantic
13151 processing during substitution as we could create partial
13153 for (i = 0; i < len; i++)
13155 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
13156 bool parameter_pack = false;
13158 /* Dig out the actual parm. */
13159 if (TREE_CODE (parm) == TYPE_DECL
13160 || TREE_CODE (parm) == TEMPLATE_DECL)
13162 parm = TREE_TYPE (parm);
13163 parameter_pack = TEMPLATE_TYPE_PARAMETER_PACK (parm);
13165 else if (TREE_CODE (parm) == PARM_DECL)
13167 parm = DECL_INITIAL (parm);
13168 parameter_pack = TEMPLATE_PARM_PARAMETER_PACK (parm);
13171 if (parameter_pack)
13175 template_parm_level_and_index (parm, &level, &idx);
13177 /* Mark the argument pack as "incomplete". We could
13178 still deduce more arguments during unification. */
13179 targ = TMPL_ARG (converted_args, level, idx);
13182 ARGUMENT_PACK_INCOMPLETE_P(targ) = 1;
13183 ARGUMENT_PACK_EXPLICIT_ARGS (targ)
13184 = ARGUMENT_PACK_ARGS (targ);
13187 /* We have some incomplete argument packs. */
13188 incomplete_argument_packs_p = true;
13192 if (incomplete_argument_packs_p)
13193 /* Any substitution is guaranteed to be incomplete if there
13194 are incomplete argument packs, because we can still deduce
13198 incomplete = NUM_TMPL_ARGS (explicit_targs) != NUM_TMPL_ARGS (targs);
13200 processing_template_decl += incomplete;
13201 fntype = tsubst (fntype, converted_args, tf_none, NULL_TREE);
13202 processing_template_decl -= incomplete;
13204 if (fntype == error_mark_node)
13207 /* Place the explicitly specified arguments in TARGS. */
13208 for (i = NUM_TMPL_ARGS (converted_args); i--;)
13209 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (converted_args, i);
13212 /* Never do unification on the 'this' parameter. */
13213 parms = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (fntype));
13219 parms = tree_cons (NULL_TREE, TREE_TYPE (fntype), parms);
13220 new_args = XALLOCAVEC (tree, nargs + 1);
13221 new_args[0] = return_type;
13222 memcpy (new_args + 1, args, nargs * sizeof (tree));
13227 /* We allow incomplete unification without an error message here
13228 because the standard doesn't seem to explicitly prohibit it. Our
13229 callers must be ready to deal with unification failures in any
13231 result = type_unification_real (DECL_INNERMOST_TEMPLATE_PARMS (fn),
13232 targs, parms, args, nargs, /*subr=*/0,
13235 if (result == 0 && incomplete_argument_packs_p)
13237 int i, len = NUM_TMPL_ARGS (targs);
13239 /* Clear the "incomplete" flags on all argument packs. */
13240 for (i = 0; i < len; i++)
13242 tree arg = TREE_VEC_ELT (targs, i);
13243 if (ARGUMENT_PACK_P (arg))
13245 ARGUMENT_PACK_INCOMPLETE_P (arg) = 0;
13246 ARGUMENT_PACK_EXPLICIT_ARGS (arg) = NULL_TREE;
13251 /* Now that we have bindings for all of the template arguments,
13252 ensure that the arguments deduced for the template template
13253 parameters have compatible template parameter lists. We cannot
13254 check this property before we have deduced all template
13255 arguments, because the template parameter types of a template
13256 template parameter might depend on prior template parameters
13257 deduced after the template template parameter. The following
13258 ill-formed example illustrates this issue:
13260 template<typename T, template<T> class C> void f(C<5>, T);
13262 template<int N> struct X {};
13265 f(X<5>(), 5l); // error: template argument deduction fails
13268 The template parameter list of 'C' depends on the template type
13269 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
13270 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
13271 time that we deduce 'C'. */
13273 && !template_template_parm_bindings_ok_p
13274 (DECL_INNERMOST_TEMPLATE_PARMS (fn), targs))
13278 /* All is well so far. Now, check:
13282 When all template arguments have been deduced, all uses of
13283 template parameters in nondeduced contexts are replaced with
13284 the corresponding deduced argument values. If the
13285 substitution results in an invalid type, as described above,
13286 type deduction fails. */
13288 tree substed = tsubst (TREE_TYPE (fn), targs, tf_none, NULL_TREE);
13289 if (substed == error_mark_node)
13292 /* If we're looking for an exact match, check that what we got
13293 is indeed an exact match. It might not be if some template
13294 parameters are used in non-deduced contexts. */
13295 if (strict == DEDUCE_EXACT)
13300 = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (substed));
13302 sarg = tree_cons (NULL_TREE, TREE_TYPE (substed), sarg);
13303 for (i = 0; i < nargs && sarg; ++i, sarg = TREE_CHAIN (sarg))
13304 if (!same_type_p (args[i], TREE_VALUE (sarg)))
13312 /* Adjust types before performing type deduction, as described in
13313 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
13314 sections are symmetric. PARM is the type of a function parameter
13315 or the return type of the conversion function. ARG is the type of
13316 the argument passed to the call, or the type of the value
13317 initialized with the result of the conversion function.
13318 ARG_EXPR is the original argument expression, which may be null. */
13321 maybe_adjust_types_for_deduction (unification_kind_t strict,
13335 /* Swap PARM and ARG throughout the remainder of this
13336 function; the handling is precisely symmetric since PARM
13337 will initialize ARG rather than vice versa. */
13345 /* Core issue #873: Do the DR606 thing (see below) for these cases,
13346 too, but here handle it by stripping the reference from PARM
13347 rather than by adding it to ARG. */
13348 if (TREE_CODE (*parm) == REFERENCE_TYPE
13349 && TYPE_REF_IS_RVALUE (*parm)
13350 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
13351 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
13352 && TREE_CODE (*arg) == REFERENCE_TYPE
13353 && !TYPE_REF_IS_RVALUE (*arg))
13354 *parm = TREE_TYPE (*parm);
13355 /* Nothing else to do in this case. */
13359 gcc_unreachable ();
13362 if (TREE_CODE (*parm) != REFERENCE_TYPE)
13364 /* [temp.deduct.call]
13366 If P is not a reference type:
13368 --If A is an array type, the pointer type produced by the
13369 array-to-pointer standard conversion (_conv.array_) is
13370 used in place of A for type deduction; otherwise,
13372 --If A is a function type, the pointer type produced by
13373 the function-to-pointer standard conversion
13374 (_conv.func_) is used in place of A for type deduction;
13377 --If A is a cv-qualified type, the top level
13378 cv-qualifiers of A's type are ignored for type
13380 if (TREE_CODE (*arg) == ARRAY_TYPE)
13381 *arg = build_pointer_type (TREE_TYPE (*arg));
13382 else if (TREE_CODE (*arg) == FUNCTION_TYPE)
13383 *arg = build_pointer_type (*arg);
13385 *arg = TYPE_MAIN_VARIANT (*arg);
13388 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
13389 of the form T&&, where T is a template parameter, and the argument
13390 is an lvalue, T is deduced as A& */
13391 if (TREE_CODE (*parm) == REFERENCE_TYPE
13392 && TYPE_REF_IS_RVALUE (*parm)
13393 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
13394 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
13395 && arg_expr && real_lvalue_p (arg_expr))
13396 *arg = build_reference_type (*arg);
13398 /* [temp.deduct.call]
13400 If P is a cv-qualified type, the top level cv-qualifiers
13401 of P's type are ignored for type deduction. If P is a
13402 reference type, the type referred to by P is used for
13404 *parm = TYPE_MAIN_VARIANT (*parm);
13405 if (TREE_CODE (*parm) == REFERENCE_TYPE)
13407 *parm = TREE_TYPE (*parm);
13408 result |= UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
13411 /* DR 322. For conversion deduction, remove a reference type on parm
13412 too (which has been swapped into ARG). */
13413 if (strict == DEDUCE_CONV && TREE_CODE (*arg) == REFERENCE_TYPE)
13414 *arg = TREE_TYPE (*arg);
13419 /* Most parms like fn_type_unification.
13421 If SUBR is 1, we're being called recursively (to unify the
13422 arguments of a function or method parameter of a function
13426 type_unification_real (tree tparms,
13430 unsigned int xnargs,
13432 unification_kind_t strict,
13435 tree parm, arg, arg_expr;
13437 int ntparms = TREE_VEC_LENGTH (tparms);
13439 int saw_undeduced = 0;
13442 unsigned int nargs;
13445 gcc_assert (TREE_CODE (tparms) == TREE_VEC);
13446 gcc_assert (xparms == NULL_TREE || TREE_CODE (xparms) == TREE_LIST);
13447 gcc_assert (ntparms > 0);
13449 /* Reset the number of non-defaulted template arguments contained
13451 NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs) = NULL_TREE;
13456 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL | UNIFY_ALLOW_MORE_CV_QUAL
13457 | UNIFY_ALLOW_DERIVED);
13461 sub_strict = UNIFY_ALLOW_LESS_CV_QUAL;
13465 sub_strict = UNIFY_ALLOW_NONE;
13469 gcc_unreachable ();
13478 while (parms && parms != void_list_node
13481 if (TREE_CODE (TREE_VALUE (parms)) == TYPE_PACK_EXPANSION)
13484 parm = TREE_VALUE (parms);
13485 parms = TREE_CHAIN (parms);
13490 if (arg == error_mark_node)
13492 if (arg == unknown_type_node)
13493 /* We can't deduce anything from this, but we might get all the
13494 template args from other function args. */
13497 /* Conversions will be performed on a function argument that
13498 corresponds with a function parameter that contains only
13499 non-deducible template parameters and explicitly specified
13500 template parameters. */
13501 if (!uses_template_parms (parm))
13506 type = TREE_TYPE (arg);
13510 if (same_type_p (parm, type))
13512 if (strict != DEDUCE_EXACT
13513 && can_convert_arg (parm, type, TYPE_P (arg) ? NULL_TREE : arg,
13522 gcc_assert (TREE_TYPE (arg) != NULL_TREE);
13523 if (type_unknown_p (arg))
13525 /* [temp.deduct.type]
13527 A template-argument can be deduced from a pointer to
13528 function or pointer to member function argument if
13529 the set of overloaded functions does not contain
13530 function templates and at most one of a set of
13531 overloaded functions provides a unique match. */
13532 if (resolve_overloaded_unification
13533 (tparms, targs, parm, arg, strict, sub_strict))
13539 arg = unlowered_expr_type (arg);
13540 if (arg == error_mark_node)
13545 int arg_strict = sub_strict;
13548 arg_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg,
13551 if (arg == init_list_type_node && arg_expr)
13553 if (unify (tparms, targs, parm, arg, arg_strict))
13560 && parms != void_list_node
13561 && TREE_CODE (TREE_VALUE (parms)) == TYPE_PACK_EXPANSION)
13563 /* Unify the remaining arguments with the pack expansion type. */
13565 tree parmvec = make_tree_vec (1);
13567 /* Allocate a TREE_VEC and copy in all of the arguments */
13568 argvec = make_tree_vec (nargs - ia);
13569 for (i = 0; ia < nargs; ++ia, ++i)
13570 TREE_VEC_ELT (argvec, i) = args[ia];
13572 /* Copy the parameter into parmvec. */
13573 TREE_VEC_ELT (parmvec, 0) = TREE_VALUE (parms);
13574 if (unify_pack_expansion (tparms, targs, parmvec, argvec, strict,
13575 /*call_args_p=*/true, /*subr=*/subr))
13578 /* Advance to the end of the list of parameters. */
13579 parms = TREE_CHAIN (parms);
13582 /* Fail if we've reached the end of the parm list, and more args
13583 are present, and the parm list isn't variadic. */
13584 if (ia < nargs && parms == void_list_node)
13586 /* Fail if parms are left and they don't have default values. */
13587 if (parms && parms != void_list_node
13588 && TREE_PURPOSE (parms) == NULL_TREE)
13592 for (i = 0; i < ntparms; i++)
13593 if (!TREE_VEC_ELT (targs, i))
13597 if (TREE_VEC_ELT (tparms, i) == error_mark_node)
13600 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
13602 /* If this is an undeduced nontype parameter that depends on
13603 a type parameter, try another pass; its type may have been
13604 deduced from a later argument than the one from which
13605 this parameter can be deduced. */
13606 if (TREE_CODE (tparm) == PARM_DECL
13607 && uses_template_parms (TREE_TYPE (tparm))
13608 && !saw_undeduced++)
13611 /* Core issue #226 (C++0x) [temp.deduct]:
13613 If a template argument has not been deduced, its
13614 default template argument, if any, is used.
13616 When we are in C++98 mode, TREE_PURPOSE will either
13617 be NULL_TREE or ERROR_MARK_NODE, so we do not need
13618 to explicitly check cxx_dialect here. */
13619 if (TREE_PURPOSE (TREE_VEC_ELT (tparms, i)))
13621 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
13622 tree arg = TREE_PURPOSE (TREE_VEC_ELT (tparms, i));
13623 arg = tsubst_template_arg (arg, targs, tf_none, NULL_TREE);
13624 arg = convert_template_argument (parm, arg, targs, tf_none,
13626 if (arg == error_mark_node)
13630 TREE_VEC_ELT (targs, i) = arg;
13631 /* The position of the first default template argument,
13632 is also the number of non-defaulted arguments in TARGS.
13634 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs))
13635 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, i);
13640 /* If the type parameter is a parameter pack, then it will
13641 be deduced to an empty parameter pack. */
13642 if (template_parameter_pack_p (tparm))
13646 if (TREE_CODE (tparm) == TEMPLATE_PARM_INDEX)
13648 arg = make_node (NONTYPE_ARGUMENT_PACK);
13649 TREE_TYPE (arg) = TREE_TYPE (TEMPLATE_PARM_DECL (tparm));
13650 TREE_CONSTANT (arg) = 1;
13653 arg = cxx_make_type (TYPE_ARGUMENT_PACK);
13655 SET_ARGUMENT_PACK_ARGS (arg, make_tree_vec (0));
13657 TREE_VEC_ELT (targs, i) = arg;
13663 #ifdef ENABLE_CHECKING
13664 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs))
13665 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, TREE_VEC_LENGTH (targs));
13671 /* Subroutine of type_unification_real. Args are like the variables
13672 at the call site. ARG is an overloaded function (or template-id);
13673 we try deducing template args from each of the overloads, and if
13674 only one succeeds, we go with that. Modifies TARGS and returns
13675 true on success. */
13678 resolve_overloaded_unification (tree tparms,
13682 unification_kind_t strict,
13685 tree tempargs = copy_node (targs);
13687 tree goodfn = NULL_TREE;
13690 if (TREE_CODE (arg) == ADDR_EXPR)
13692 arg = TREE_OPERAND (arg, 0);
13698 if (TREE_CODE (arg) == COMPONENT_REF)
13699 /* Handle `&x' where `x' is some static or non-static member
13701 arg = TREE_OPERAND (arg, 1);
13703 if (TREE_CODE (arg) == OFFSET_REF)
13704 arg = TREE_OPERAND (arg, 1);
13706 /* Strip baselink information. */
13707 if (BASELINK_P (arg))
13708 arg = BASELINK_FUNCTIONS (arg);
13710 if (TREE_CODE (arg) == TEMPLATE_ID_EXPR)
13712 /* If we got some explicit template args, we need to plug them into
13713 the affected templates before we try to unify, in case the
13714 explicit args will completely resolve the templates in question. */
13716 tree expl_subargs = TREE_OPERAND (arg, 1);
13717 arg = TREE_OPERAND (arg, 0);
13719 for (; arg; arg = OVL_NEXT (arg))
13721 tree fn = OVL_CURRENT (arg);
13722 tree subargs, elem;
13724 if (TREE_CODE (fn) != TEMPLATE_DECL)
13727 ++processing_template_decl;
13728 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
13729 expl_subargs, /*check_ret=*/false);
13732 elem = tsubst (TREE_TYPE (fn), subargs, tf_none, NULL_TREE);
13733 if (try_one_overload (tparms, targs, tempargs, parm,
13734 elem, strict, sub_strict, addr_p)
13735 && (!goodfn || !decls_match (goodfn, elem)))
13741 --processing_template_decl;
13744 else if (TREE_CODE (arg) != OVERLOAD
13745 && TREE_CODE (arg) != FUNCTION_DECL)
13746 /* If ARG is, for example, "(0, &f)" then its type will be unknown
13747 -- but the deduction does not succeed because the expression is
13748 not just the function on its own. */
13751 for (; arg; arg = OVL_NEXT (arg))
13752 if (try_one_overload (tparms, targs, tempargs, parm,
13753 TREE_TYPE (OVL_CURRENT (arg)),
13754 strict, sub_strict, addr_p)
13755 && (!goodfn || !decls_match (goodfn, OVL_CURRENT (arg))))
13757 goodfn = OVL_CURRENT (arg);
13761 /* [temp.deduct.type] A template-argument can be deduced from a pointer
13762 to function or pointer to member function argument if the set of
13763 overloaded functions does not contain function templates and at most
13764 one of a set of overloaded functions provides a unique match.
13766 So if we found multiple possibilities, we return success but don't
13767 deduce anything. */
13771 int i = TREE_VEC_LENGTH (targs);
13773 if (TREE_VEC_ELT (tempargs, i))
13774 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (tempargs, i);
13782 /* Core DR 115: In contexts where deduction is done and fails, or in
13783 contexts where deduction is not done, if a template argument list is
13784 specified and it, along with any default template arguments, identifies
13785 a single function template specialization, then the template-id is an
13786 lvalue for the function template specialization. */
13789 resolve_nondeduced_context (tree orig_expr)
13791 tree expr, offset, baselink;
13794 if (!type_unknown_p (orig_expr))
13799 offset = NULL_TREE;
13800 baselink = NULL_TREE;
13802 if (TREE_CODE (expr) == ADDR_EXPR)
13804 expr = TREE_OPERAND (expr, 0);
13807 if (TREE_CODE (expr) == OFFSET_REF)
13810 expr = TREE_OPERAND (expr, 1);
13812 if (TREE_CODE (expr) == BASELINK)
13815 expr = BASELINK_FUNCTIONS (expr);
13818 if (TREE_CODE (expr) == TEMPLATE_ID_EXPR)
13821 tree goodfn = NULL_TREE;
13823 /* If we got some explicit template args, we need to plug them into
13824 the affected templates before we try to unify, in case the
13825 explicit args will completely resolve the templates in question. */
13827 tree expl_subargs = TREE_OPERAND (expr, 1);
13828 tree arg = TREE_OPERAND (expr, 0);
13829 tree badfn = NULL_TREE;
13830 tree badargs = NULL_TREE;
13832 for (; arg; arg = OVL_NEXT (arg))
13834 tree fn = OVL_CURRENT (arg);
13835 tree subargs, elem;
13837 if (TREE_CODE (fn) != TEMPLATE_DECL)
13840 ++processing_template_decl;
13841 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
13842 expl_subargs, /*check_ret=*/false);
13843 if (subargs && !any_dependent_template_arguments_p (subargs))
13845 elem = instantiate_template (fn, subargs, tf_none);
13846 if (elem == error_mark_node)
13851 else if (elem && (!goodfn || !decls_match (goodfn, elem)))
13857 --processing_template_decl;
13863 expr = build_baselink (BASELINK_BINFO (baselink),
13864 BASELINK_ACCESS_BINFO (baselink),
13865 expr, BASELINK_OPTYPE (baselink));
13867 expr = build2 (OFFSET_REF, TREE_TYPE (expr),
13868 TREE_OPERAND (offset, 0), expr);
13870 expr = build_address (expr);
13873 else if (good == 0 && badargs)
13874 /* There were no good options and at least one bad one, so let the
13875 user know what the problem is. */
13876 instantiate_template (badfn, badargs, tf_warning_or_error);
13881 /* Subroutine of resolve_overloaded_unification; does deduction for a single
13882 overload. Fills TARGS with any deduced arguments, or error_mark_node if
13883 different overloads deduce different arguments for a given parm.
13884 ADDR_P is true if the expression for which deduction is being
13885 performed was of the form "& fn" rather than simply "fn".
13887 Returns 1 on success. */
13890 try_one_overload (tree tparms,
13895 unification_kind_t strict,
13903 /* [temp.deduct.type] A template-argument can be deduced from a pointer
13904 to function or pointer to member function argument if the set of
13905 overloaded functions does not contain function templates and at most
13906 one of a set of overloaded functions provides a unique match.
13908 So if this is a template, just return success. */
13910 if (uses_template_parms (arg))
13913 if (TREE_CODE (arg) == METHOD_TYPE)
13914 arg = build_ptrmemfunc_type (build_pointer_type (arg));
13916 arg = build_pointer_type (arg);
13918 sub_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg, NULL);
13920 /* We don't copy orig_targs for this because if we have already deduced
13921 some template args from previous args, unify would complain when we
13922 try to deduce a template parameter for the same argument, even though
13923 there isn't really a conflict. */
13924 nargs = TREE_VEC_LENGTH (targs);
13925 tempargs = make_tree_vec (nargs);
13927 if (unify (tparms, tempargs, parm, arg, sub_strict) != 0)
13930 /* First make sure we didn't deduce anything that conflicts with
13931 explicitly specified args. */
13932 for (i = nargs; i--; )
13934 tree elt = TREE_VEC_ELT (tempargs, i);
13935 tree oldelt = TREE_VEC_ELT (orig_targs, i);
13939 else if (uses_template_parms (elt))
13940 /* Since we're unifying against ourselves, we will fill in
13941 template args used in the function parm list with our own
13942 template parms. Discard them. */
13943 TREE_VEC_ELT (tempargs, i) = NULL_TREE;
13944 else if (oldelt && !template_args_equal (oldelt, elt))
13948 for (i = nargs; i--; )
13950 tree elt = TREE_VEC_ELT (tempargs, i);
13953 TREE_VEC_ELT (targs, i) = elt;
13959 /* PARM is a template class (perhaps with unbound template
13960 parameters). ARG is a fully instantiated type. If ARG can be
13961 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
13962 TARGS are as for unify. */
13965 try_class_unification (tree tparms, tree targs, tree parm, tree arg)
13967 tree copy_of_targs;
13969 if (!CLASSTYPE_TEMPLATE_INFO (arg)
13970 || (most_general_template (CLASSTYPE_TI_TEMPLATE (arg))
13971 != most_general_template (CLASSTYPE_TI_TEMPLATE (parm))))
13974 /* We need to make a new template argument vector for the call to
13975 unify. If we used TARGS, we'd clutter it up with the result of
13976 the attempted unification, even if this class didn't work out.
13977 We also don't want to commit ourselves to all the unifications
13978 we've already done, since unification is supposed to be done on
13979 an argument-by-argument basis. In other words, consider the
13980 following pathological case:
13982 template <int I, int J, int K>
13985 template <int I, int J>
13986 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
13988 template <int I, int J, int K>
13989 void f(S<I, J, K>, S<I, I, I>);
13998 Now, by the time we consider the unification involving `s2', we
13999 already know that we must have `f<0, 0, 0>'. But, even though
14000 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
14001 because there are two ways to unify base classes of S<0, 1, 2>
14002 with S<I, I, I>. If we kept the already deduced knowledge, we
14003 would reject the possibility I=1. */
14004 copy_of_targs = make_tree_vec (TREE_VEC_LENGTH (targs));
14006 /* If unification failed, we're done. */
14007 if (unify (tparms, copy_of_targs, CLASSTYPE_TI_ARGS (parm),
14008 CLASSTYPE_TI_ARGS (arg), UNIFY_ALLOW_NONE))
14014 /* Given a template type PARM and a class type ARG, find the unique
14015 base type in ARG that is an instance of PARM. We do not examine
14016 ARG itself; only its base-classes. If there is not exactly one
14017 appropriate base class, return NULL_TREE. PARM may be the type of
14018 a partial specialization, as well as a plain template type. Used
14022 get_template_base (tree tparms, tree targs, tree parm, tree arg)
14024 tree rval = NULL_TREE;
14027 gcc_assert (RECORD_OR_UNION_CODE_P (TREE_CODE (arg)));
14029 binfo = TYPE_BINFO (complete_type (arg));
14031 /* The type could not be completed. */
14034 /* Walk in inheritance graph order. The search order is not
14035 important, and this avoids multiple walks of virtual bases. */
14036 for (binfo = TREE_CHAIN (binfo); binfo; binfo = TREE_CHAIN (binfo))
14038 tree r = try_class_unification (tparms, targs, parm, BINFO_TYPE (binfo));
14042 /* If there is more than one satisfactory baseclass, then:
14046 If they yield more than one possible deduced A, the type
14050 if (rval && !same_type_p (r, rval))
14060 /* Returns the level of DECL, which declares a template parameter. */
14063 template_decl_level (tree decl)
14065 switch (TREE_CODE (decl))
14068 case TEMPLATE_DECL:
14069 return TEMPLATE_TYPE_LEVEL (TREE_TYPE (decl));
14072 return TEMPLATE_PARM_LEVEL (DECL_INITIAL (decl));
14075 gcc_unreachable ();
14080 /* Decide whether ARG can be unified with PARM, considering only the
14081 cv-qualifiers of each type, given STRICT as documented for unify.
14082 Returns nonzero iff the unification is OK on that basis. */
14085 check_cv_quals_for_unify (int strict, tree arg, tree parm)
14087 int arg_quals = cp_type_quals (arg);
14088 int parm_quals = cp_type_quals (parm);
14090 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
14091 && !(strict & UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
14093 /* Although a CVR qualifier is ignored when being applied to a
14094 substituted template parameter ([8.3.2]/1 for example), that
14095 does not apply during deduction [14.8.2.4]/1, (even though
14096 that is not explicitly mentioned, [14.8.2.4]/9 indicates
14097 this). Except when we're allowing additional CV qualifiers
14098 at the outer level [14.8.2.1]/3,1st bullet. */
14099 if ((TREE_CODE (arg) == REFERENCE_TYPE
14100 || TREE_CODE (arg) == FUNCTION_TYPE
14101 || TREE_CODE (arg) == METHOD_TYPE)
14102 && (parm_quals & (TYPE_QUAL_CONST | TYPE_QUAL_VOLATILE)))
14105 if ((!POINTER_TYPE_P (arg) && TREE_CODE (arg) != TEMPLATE_TYPE_PARM)
14106 && (parm_quals & TYPE_QUAL_RESTRICT))
14110 if (!(strict & (UNIFY_ALLOW_MORE_CV_QUAL | UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
14111 && (arg_quals & parm_quals) != parm_quals)
14114 if (!(strict & (UNIFY_ALLOW_LESS_CV_QUAL | UNIFY_ALLOW_OUTER_LESS_CV_QUAL))
14115 && (parm_quals & arg_quals) != arg_quals)
14121 /* Determines the LEVEL and INDEX for the template parameter PARM. */
14123 template_parm_level_and_index (tree parm, int* level, int* index)
14125 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
14126 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
14127 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
14129 *index = TEMPLATE_TYPE_IDX (parm);
14130 *level = TEMPLATE_TYPE_LEVEL (parm);
14134 *index = TEMPLATE_PARM_IDX (parm);
14135 *level = TEMPLATE_PARM_LEVEL (parm);
14139 /* Unifies the remaining arguments in PACKED_ARGS with the pack
14140 expansion at the end of PACKED_PARMS. Returns 0 if the type
14141 deduction succeeds, 1 otherwise. STRICT is the same as in
14142 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
14143 call argument list. We'll need to adjust the arguments to make them
14144 types. SUBR tells us if this is from a recursive call to
14145 type_unification_real. */
14147 unify_pack_expansion (tree tparms, tree targs, tree packed_parms,
14148 tree packed_args, int strict, bool call_args_p,
14152 = TREE_VEC_ELT (packed_parms, TREE_VEC_LENGTH (packed_parms) - 1);
14153 tree pattern = PACK_EXPANSION_PATTERN (parm);
14154 tree pack, packs = NULL_TREE;
14155 int i, start = TREE_VEC_LENGTH (packed_parms) - 1;
14156 int len = TREE_VEC_LENGTH (packed_args);
14158 /* Determine the parameter packs we will be deducing from the
14159 pattern, and record their current deductions. */
14160 for (pack = PACK_EXPANSION_PARAMETER_PACKS (parm);
14161 pack; pack = TREE_CHAIN (pack))
14163 tree parm_pack = TREE_VALUE (pack);
14166 /* Determine the index and level of this parameter pack. */
14167 template_parm_level_and_index (parm_pack, &level, &idx);
14169 /* Keep track of the parameter packs and their corresponding
14171 packs = tree_cons (parm_pack, TMPL_ARG (targs, level, idx), packs);
14172 TREE_TYPE (packs) = make_tree_vec (len - start);
14175 /* Loop through all of the arguments that have not yet been
14176 unified and unify each with the pattern. */
14177 for (i = start; i < len; i++)
14179 tree parm = pattern;
14181 /* For each parameter pack, clear out the deduced value so that
14182 we can deduce it again. */
14183 for (pack = packs; pack; pack = TREE_CHAIN (pack))
14186 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
14188 TMPL_ARG (targs, level, idx) = NULL_TREE;
14191 /* Unify the pattern with the current argument. */
14193 tree arg = TREE_VEC_ELT (packed_args, i);
14194 tree arg_expr = NULL_TREE;
14195 int arg_strict = strict;
14196 bool skip_arg_p = false;
14202 /* This mirrors what we do in type_unification_real. */
14206 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL
14207 | UNIFY_ALLOW_MORE_CV_QUAL
14208 | UNIFY_ALLOW_DERIVED);
14212 sub_strict = UNIFY_ALLOW_LESS_CV_QUAL;
14216 sub_strict = UNIFY_ALLOW_NONE;
14220 gcc_unreachable ();
14225 gcc_assert (TREE_TYPE (arg) != NULL_TREE);
14226 if (type_unknown_p (arg))
14228 /* [temp.deduct.type] A template-argument can be
14229 deduced from a pointer to function or pointer
14230 to member function argument if the set of
14231 overloaded functions does not contain function
14232 templates and at most one of a set of
14233 overloaded functions provides a unique
14236 if (resolve_overloaded_unification
14237 (tparms, targs, parm, arg,
14238 (unification_kind_t) strict,
14248 arg = unlowered_expr_type (arg);
14249 if (arg == error_mark_node)
14254 arg_strict = sub_strict;
14258 maybe_adjust_types_for_deduction ((unification_kind_t) strict,
14259 &parm, &arg, arg_expr);
14264 /* For deduction from an init-list we need the actual list. */
14265 if (arg_expr && BRACE_ENCLOSED_INITIALIZER_P (arg_expr))
14267 if (unify (tparms, targs, parm, arg, arg_strict))
14272 /* For each parameter pack, collect the deduced value. */
14273 for (pack = packs; pack; pack = TREE_CHAIN (pack))
14276 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
14278 TREE_VEC_ELT (TREE_TYPE (pack), i - start) =
14279 TMPL_ARG (targs, level, idx);
14283 /* Verify that the results of unification with the parameter packs
14284 produce results consistent with what we've seen before, and make
14285 the deduced argument packs available. */
14286 for (pack = packs; pack; pack = TREE_CHAIN (pack))
14288 tree old_pack = TREE_VALUE (pack);
14289 tree new_args = TREE_TYPE (pack);
14290 int i, len = TREE_VEC_LENGTH (new_args);
14292 bool nondeduced_p = false;
14294 /* By default keep the original deduced argument pack.
14295 If necessary, more specific code is going to update the
14296 resulting deduced argument later down in this function. */
14297 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
14298 TMPL_ARG (targs, level, idx) = old_pack;
14300 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
14301 actually deduce anything. */
14302 for (i = 0; i < len && !nondeduced_p; ++i)
14303 if (TREE_VEC_ELT (new_args, i) == NULL_TREE)
14304 nondeduced_p = true;
14308 if (old_pack && ARGUMENT_PACK_INCOMPLETE_P (old_pack))
14310 /* Prepend the explicit arguments onto NEW_ARGS. */
14311 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
14312 tree old_args = new_args;
14313 int i, explicit_len = TREE_VEC_LENGTH (explicit_args);
14314 int len = explicit_len + TREE_VEC_LENGTH (old_args);
14316 /* Copy the explicit arguments. */
14317 new_args = make_tree_vec (len);
14318 for (i = 0; i < explicit_len; i++)
14319 TREE_VEC_ELT (new_args, i) = TREE_VEC_ELT (explicit_args, i);
14321 /* Copy the deduced arguments. */
14322 for (; i < len; i++)
14323 TREE_VEC_ELT (new_args, i) =
14324 TREE_VEC_ELT (old_args, i - explicit_len);
14330 /* Build the deduced *_ARGUMENT_PACK. */
14331 if (TREE_CODE (TREE_PURPOSE (pack)) == TEMPLATE_PARM_INDEX)
14333 result = make_node (NONTYPE_ARGUMENT_PACK);
14334 TREE_TYPE (result) =
14335 TREE_TYPE (TEMPLATE_PARM_DECL (TREE_PURPOSE (pack)));
14336 TREE_CONSTANT (result) = 1;
14339 result = cxx_make_type (TYPE_ARGUMENT_PACK);
14341 SET_ARGUMENT_PACK_ARGS (result, new_args);
14343 /* Note the deduced argument packs for this parameter
14345 TMPL_ARG (targs, level, idx) = result;
14347 else if (ARGUMENT_PACK_INCOMPLETE_P (old_pack)
14348 && (ARGUMENT_PACK_ARGS (old_pack)
14349 == ARGUMENT_PACK_EXPLICIT_ARGS (old_pack)))
14351 /* We only had the explicitly-provided arguments before, but
14352 now we have a complete set of arguments. */
14353 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
14355 SET_ARGUMENT_PACK_ARGS (old_pack, new_args);
14356 ARGUMENT_PACK_INCOMPLETE_P (old_pack) = 1;
14357 ARGUMENT_PACK_EXPLICIT_ARGS (old_pack) = explicit_args;
14359 else if (!comp_template_args (ARGUMENT_PACK_ARGS (old_pack),
14361 /* Inconsistent unification of this parameter pack. */
14368 /* Deduce the value of template parameters. TPARMS is the (innermost)
14369 set of template parameters to a template. TARGS is the bindings
14370 for those template parameters, as determined thus far; TARGS may
14371 include template arguments for outer levels of template parameters
14372 as well. PARM is a parameter to a template function, or a
14373 subcomponent of that parameter; ARG is the corresponding argument.
14374 This function attempts to match PARM with ARG in a manner
14375 consistent with the existing assignments in TARGS. If more values
14376 are deduced, then TARGS is updated.
14378 Returns 0 if the type deduction succeeds, 1 otherwise. The
14379 parameter STRICT is a bitwise or of the following flags:
14382 Require an exact match between PARM and ARG.
14383 UNIFY_ALLOW_MORE_CV_QUAL:
14384 Allow the deduced ARG to be more cv-qualified (by qualification
14385 conversion) than ARG.
14386 UNIFY_ALLOW_LESS_CV_QUAL:
14387 Allow the deduced ARG to be less cv-qualified than ARG.
14388 UNIFY_ALLOW_DERIVED:
14389 Allow the deduced ARG to be a template base class of ARG,
14390 or a pointer to a template base class of the type pointed to by
14392 UNIFY_ALLOW_INTEGER:
14393 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
14394 case for more information.
14395 UNIFY_ALLOW_OUTER_LEVEL:
14396 This is the outermost level of a deduction. Used to determine validity
14397 of qualification conversions. A valid qualification conversion must
14398 have const qualified pointers leading up to the inner type which
14399 requires additional CV quals, except at the outer level, where const
14400 is not required [conv.qual]. It would be normal to set this flag in
14401 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
14402 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
14403 This is the outermost level of a deduction, and PARM can be more CV
14404 qualified at this point.
14405 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
14406 This is the outermost level of a deduction, and PARM can be less CV
14407 qualified at this point. */
14410 unify (tree tparms, tree targs, tree parm, tree arg, int strict)
14415 int strict_in = strict;
14417 /* I don't think this will do the right thing with respect to types.
14418 But the only case I've seen it in so far has been array bounds, where
14419 signedness is the only information lost, and I think that will be
14421 while (TREE_CODE (parm) == NOP_EXPR)
14422 parm = TREE_OPERAND (parm, 0);
14424 if (arg == error_mark_node)
14426 if (arg == unknown_type_node
14427 || arg == init_list_type_node)
14428 /* We can't deduce anything from this, but we might get all the
14429 template args from other function args. */
14432 /* If PARM uses template parameters, then we can't bail out here,
14433 even if ARG == PARM, since we won't record unifications for the
14434 template parameters. We might need them if we're trying to
14435 figure out which of two things is more specialized. */
14436 if (arg == parm && !uses_template_parms (parm))
14439 /* Handle init lists early, so the rest of the function can assume
14440 we're dealing with a type. */
14441 if (BRACE_ENCLOSED_INITIALIZER_P (arg))
14445 tree orig_parm = parm;
14447 /* Replace T with std::initializer_list<T> for deduction. */
14448 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
14449 && flag_deduce_init_list)
14450 parm = listify (parm);
14452 if (!is_std_init_list (parm))
14453 /* We can only deduce from an initializer list argument if the
14454 parameter is std::initializer_list; otherwise this is a
14455 non-deduced context. */
14458 elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (parm), 0);
14460 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg), i, elt)
14462 int elt_strict = strict;
14463 if (!BRACE_ENCLOSED_INITIALIZER_P (elt))
14465 tree type = TREE_TYPE (elt);
14466 /* It should only be possible to get here for a call. */
14467 gcc_assert (elt_strict & UNIFY_ALLOW_OUTER_LEVEL);
14468 elt_strict |= maybe_adjust_types_for_deduction
14469 (DEDUCE_CALL, &elttype, &type, elt);
14473 if (unify (tparms, targs, elttype, elt, elt_strict))
14477 /* If the std::initializer_list<T> deduction worked, replace the
14478 deduced A with std::initializer_list<A>. */
14479 if (orig_parm != parm)
14481 idx = TEMPLATE_TYPE_IDX (orig_parm);
14482 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
14483 targ = listify (targ);
14484 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = targ;
14489 /* Immediately reject some pairs that won't unify because of
14490 cv-qualification mismatches. */
14491 if (TREE_CODE (arg) == TREE_CODE (parm)
14493 /* It is the elements of the array which hold the cv quals of an array
14494 type, and the elements might be template type parms. We'll check
14495 when we recurse. */
14496 && TREE_CODE (arg) != ARRAY_TYPE
14497 /* We check the cv-qualifiers when unifying with template type
14498 parameters below. We want to allow ARG `const T' to unify with
14499 PARM `T' for example, when computing which of two templates
14500 is more specialized, for example. */
14501 && TREE_CODE (arg) != TEMPLATE_TYPE_PARM
14502 && !check_cv_quals_for_unify (strict_in, arg, parm))
14505 if (!(strict & UNIFY_ALLOW_OUTER_LEVEL)
14506 && TYPE_P (parm) && !CP_TYPE_CONST_P (parm))
14507 strict &= ~UNIFY_ALLOW_MORE_CV_QUAL;
14508 strict &= ~UNIFY_ALLOW_OUTER_LEVEL;
14509 strict &= ~UNIFY_ALLOW_DERIVED;
14510 strict &= ~UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
14511 strict &= ~UNIFY_ALLOW_OUTER_LESS_CV_QUAL;
14513 switch (TREE_CODE (parm))
14515 case TYPENAME_TYPE:
14517 case UNBOUND_CLASS_TEMPLATE:
14518 /* In a type which contains a nested-name-specifier, template
14519 argument values cannot be deduced for template parameters used
14520 within the nested-name-specifier. */
14523 case TEMPLATE_TYPE_PARM:
14524 case TEMPLATE_TEMPLATE_PARM:
14525 case BOUND_TEMPLATE_TEMPLATE_PARM:
14526 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
14527 if (tparm == error_mark_node)
14530 if (TEMPLATE_TYPE_LEVEL (parm)
14531 != template_decl_level (tparm))
14532 /* The PARM is not one we're trying to unify. Just check
14533 to see if it matches ARG. */
14534 return (TREE_CODE (arg) == TREE_CODE (parm)
14535 && same_type_p (parm, arg)) ? 0 : 1;
14536 idx = TEMPLATE_TYPE_IDX (parm);
14537 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
14538 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, idx));
14540 /* Check for mixed types and values. */
14541 if ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
14542 && TREE_CODE (tparm) != TYPE_DECL)
14543 || (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
14544 && TREE_CODE (tparm) != TEMPLATE_DECL))
14547 if (TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
14549 /* ARG must be constructed from a template class or a template
14550 template parameter. */
14551 if (TREE_CODE (arg) != BOUND_TEMPLATE_TEMPLATE_PARM
14552 && !CLASSTYPE_SPECIALIZATION_OF_PRIMARY_TEMPLATE_P (arg))
14556 tree parmvec = TYPE_TI_ARGS (parm);
14557 tree argvec = INNERMOST_TEMPLATE_ARGS (TYPE_TI_ARGS (arg));
14559 = DECL_INNERMOST_TEMPLATE_PARMS
14560 (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (parm));
14562 int parm_variadic_p = 0;
14564 /* The resolution to DR150 makes clear that default
14565 arguments for an N-argument may not be used to bind T
14566 to a template template parameter with fewer than N
14567 parameters. It is not safe to permit the binding of
14568 default arguments as an extension, as that may change
14569 the meaning of a conforming program. Consider:
14571 struct Dense { static const unsigned int dim = 1; };
14573 template <template <typename> class View,
14575 void operator+(float, View<Block> const&);
14577 template <typename Block,
14578 unsigned int Dim = Block::dim>
14579 struct Lvalue_proxy { operator float() const; };
14583 Lvalue_proxy<Dense> p;
14588 Here, if Lvalue_proxy is permitted to bind to View, then
14589 the global operator+ will be used; if they are not, the
14590 Lvalue_proxy will be converted to float. */
14591 if (coerce_template_parms (parm_parms,
14593 TYPE_TI_TEMPLATE (parm),
14595 /*require_all_args=*/true,
14596 /*use_default_args=*/false)
14597 == error_mark_node)
14600 /* Deduce arguments T, i from TT<T> or TT<i>.
14601 We check each element of PARMVEC and ARGVEC individually
14602 rather than the whole TREE_VEC since they can have
14603 different number of elements. */
14605 parmvec = expand_template_argument_pack (parmvec);
14606 argvec = expand_template_argument_pack (argvec);
14608 len = TREE_VEC_LENGTH (parmvec);
14610 /* Check if the parameters end in a pack, making them
14613 && PACK_EXPANSION_P (TREE_VEC_ELT (parmvec, len - 1)))
14614 parm_variadic_p = 1;
14616 if (TREE_VEC_LENGTH (argvec) < len - parm_variadic_p)
14619 for (i = 0; i < len - parm_variadic_p; ++i)
14621 if (unify (tparms, targs,
14622 TREE_VEC_ELT (parmvec, i),
14623 TREE_VEC_ELT (argvec, i),
14628 if (parm_variadic_p
14629 && unify_pack_expansion (tparms, targs,
14632 /*call_args_p=*/false,
14636 arg = TYPE_TI_TEMPLATE (arg);
14638 /* Fall through to deduce template name. */
14641 if (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
14642 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
14644 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
14646 /* Simple cases: Value already set, does match or doesn't. */
14647 if (targ != NULL_TREE && template_args_equal (targ, arg))
14654 /* If PARM is `const T' and ARG is only `int', we don't have
14655 a match unless we are allowing additional qualification.
14656 If ARG is `const int' and PARM is just `T' that's OK;
14657 that binds `const int' to `T'. */
14658 if (!check_cv_quals_for_unify (strict_in | UNIFY_ALLOW_LESS_CV_QUAL,
14662 /* Consider the case where ARG is `const volatile int' and
14663 PARM is `const T'. Then, T should be `volatile int'. */
14664 arg = cp_build_qualified_type_real
14665 (arg, cp_type_quals (arg) & ~cp_type_quals (parm), tf_none);
14666 if (arg == error_mark_node)
14669 /* Simple cases: Value already set, does match or doesn't. */
14670 if (targ != NULL_TREE && same_type_p (targ, arg))
14675 /* Make sure that ARG is not a variable-sized array. (Note
14676 that were talking about variable-sized arrays (like
14677 `int[n]'), rather than arrays of unknown size (like
14678 `int[]').) We'll get very confused by such a type since
14679 the bound of the array will not be computable in an
14680 instantiation. Besides, such types are not allowed in
14681 ISO C++, so we can do as we please here. */
14682 if (variably_modified_type_p (arg, NULL_TREE))
14685 /* Strip typedefs as in convert_template_argument. */
14686 arg = strip_typedefs (arg);
14689 /* If ARG is a parameter pack or an expansion, we cannot unify
14690 against it unless PARM is also a parameter pack. */
14691 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
14692 && !template_parameter_pack_p (parm))
14695 /* If the argument deduction results is a METHOD_TYPE,
14696 then there is a problem.
14697 METHOD_TYPE doesn't map to any real C++ type the result of
14698 the deduction can not be of that type. */
14699 if (TREE_CODE (arg) == METHOD_TYPE)
14702 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
14705 case TEMPLATE_PARM_INDEX:
14706 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
14707 if (tparm == error_mark_node)
14710 if (TEMPLATE_PARM_LEVEL (parm)
14711 != template_decl_level (tparm))
14712 /* The PARM is not one we're trying to unify. Just check
14713 to see if it matches ARG. */
14714 return !(TREE_CODE (arg) == TREE_CODE (parm)
14715 && cp_tree_equal (parm, arg));
14717 idx = TEMPLATE_PARM_IDX (parm);
14718 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
14721 return !cp_tree_equal (targ, arg);
14723 /* [temp.deduct.type] If, in the declaration of a function template
14724 with a non-type template-parameter, the non-type
14725 template-parameter is used in an expression in the function
14726 parameter-list and, if the corresponding template-argument is
14727 deduced, the template-argument type shall match the type of the
14728 template-parameter exactly, except that a template-argument
14729 deduced from an array bound may be of any integral type.
14730 The non-type parameter might use already deduced type parameters. */
14731 tparm = tsubst (TREE_TYPE (parm), targs, 0, NULL_TREE);
14732 if (!TREE_TYPE (arg))
14733 /* Template-parameter dependent expression. Just accept it for now.
14734 It will later be processed in convert_template_argument. */
14736 else if (same_type_p (TREE_TYPE (arg), tparm))
14738 else if ((strict & UNIFY_ALLOW_INTEGER)
14739 && (TREE_CODE (tparm) == INTEGER_TYPE
14740 || TREE_CODE (tparm) == BOOLEAN_TYPE))
14741 /* Convert the ARG to the type of PARM; the deduced non-type
14742 template argument must exactly match the types of the
14743 corresponding parameter. */
14744 arg = fold (build_nop (tparm, arg));
14745 else if (uses_template_parms (tparm))
14746 /* We haven't deduced the type of this parameter yet. Try again
14752 /* If ARG is a parameter pack or an expansion, we cannot unify
14753 against it unless PARM is also a parameter pack. */
14754 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
14755 && !TEMPLATE_PARM_PARAMETER_PACK (parm))
14758 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
14763 /* A pointer-to-member constant can be unified only with
14764 another constant. */
14765 if (TREE_CODE (arg) != PTRMEM_CST)
14768 /* Just unify the class member. It would be useless (and possibly
14769 wrong, depending on the strict flags) to unify also
14770 PTRMEM_CST_CLASS, because we want to be sure that both parm and
14771 arg refer to the same variable, even if through different
14772 classes. For instance:
14774 struct A { int x; };
14777 Unification of &A::x and &B::x must succeed. */
14778 return unify (tparms, targs, PTRMEM_CST_MEMBER (parm),
14779 PTRMEM_CST_MEMBER (arg), strict);
14784 if (TREE_CODE (arg) != POINTER_TYPE)
14787 /* [temp.deduct.call]
14789 A can be another pointer or pointer to member type that can
14790 be converted to the deduced A via a qualification
14791 conversion (_conv.qual_).
14793 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
14794 This will allow for additional cv-qualification of the
14795 pointed-to types if appropriate. */
14797 if (TREE_CODE (TREE_TYPE (arg)) == RECORD_TYPE)
14798 /* The derived-to-base conversion only persists through one
14799 level of pointers. */
14800 strict |= (strict_in & UNIFY_ALLOW_DERIVED);
14802 return unify (tparms, targs, TREE_TYPE (parm),
14803 TREE_TYPE (arg), strict);
14806 case REFERENCE_TYPE:
14807 if (TREE_CODE (arg) != REFERENCE_TYPE)
14809 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
14810 strict & UNIFY_ALLOW_MORE_CV_QUAL);
14813 if (TREE_CODE (arg) != ARRAY_TYPE)
14815 if ((TYPE_DOMAIN (parm) == NULL_TREE)
14816 != (TYPE_DOMAIN (arg) == NULL_TREE))
14818 if (TYPE_DOMAIN (parm) != NULL_TREE)
14825 /* Our representation of array types uses "N - 1" as the
14826 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
14827 not an integer constant. We cannot unify arbitrarily
14828 complex expressions, so we eliminate the MINUS_EXPRs
14830 parm_max = TYPE_MAX_VALUE (TYPE_DOMAIN (parm));
14831 parm_cst = TREE_CODE (parm_max) == INTEGER_CST;
14834 gcc_assert (TREE_CODE (parm_max) == MINUS_EXPR);
14835 parm_max = TREE_OPERAND (parm_max, 0);
14837 arg_max = TYPE_MAX_VALUE (TYPE_DOMAIN (arg));
14838 arg_cst = TREE_CODE (arg_max) == INTEGER_CST;
14841 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
14842 trying to unify the type of a variable with the type
14843 of a template parameter. For example:
14845 template <unsigned int N>
14846 void f (char (&) [N]);
14853 Here, the type of the ARG will be "int [g(i)]", and
14854 may be a SAVE_EXPR, etc. */
14855 if (TREE_CODE (arg_max) != MINUS_EXPR)
14857 arg_max = TREE_OPERAND (arg_max, 0);
14860 /* If only one of the bounds used a MINUS_EXPR, compensate
14861 by adding one to the other bound. */
14862 if (parm_cst && !arg_cst)
14863 parm_max = fold_build2_loc (input_location, PLUS_EXPR,
14867 else if (arg_cst && !parm_cst)
14868 arg_max = fold_build2_loc (input_location, PLUS_EXPR,
14873 if (unify (tparms, targs, parm_max, arg_max, UNIFY_ALLOW_INTEGER))
14876 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
14877 strict & UNIFY_ALLOW_MORE_CV_QUAL);
14884 case ENUMERAL_TYPE:
14886 if (TREE_CODE (arg) != TREE_CODE (parm))
14889 /* We have already checked cv-qualification at the top of the
14891 if (!same_type_ignoring_top_level_qualifiers_p (arg, parm))
14894 /* As far as unification is concerned, this wins. Later checks
14895 will invalidate it if necessary. */
14898 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
14899 /* Type INTEGER_CST can come from ordinary constant template args. */
14901 while (TREE_CODE (arg) == NOP_EXPR)
14902 arg = TREE_OPERAND (arg, 0);
14904 if (TREE_CODE (arg) != INTEGER_CST)
14906 return !tree_int_cst_equal (parm, arg);
14911 if (TREE_CODE (arg) != TREE_VEC)
14913 if (TREE_VEC_LENGTH (parm) != TREE_VEC_LENGTH (arg))
14915 for (i = 0; i < TREE_VEC_LENGTH (parm); ++i)
14916 if (unify (tparms, targs,
14917 TREE_VEC_ELT (parm, i), TREE_VEC_ELT (arg, i),
14925 if (TREE_CODE (arg) != TREE_CODE (parm))
14928 if (TYPE_PTRMEMFUNC_P (parm))
14930 if (!TYPE_PTRMEMFUNC_P (arg))
14933 return unify (tparms, targs,
14934 TYPE_PTRMEMFUNC_FN_TYPE (parm),
14935 TYPE_PTRMEMFUNC_FN_TYPE (arg),
14939 if (CLASSTYPE_TEMPLATE_INFO (parm))
14941 tree t = NULL_TREE;
14943 if (strict_in & UNIFY_ALLOW_DERIVED)
14945 /* First, we try to unify the PARM and ARG directly. */
14946 t = try_class_unification (tparms, targs,
14951 /* Fallback to the special case allowed in
14952 [temp.deduct.call]:
14954 If P is a class, and P has the form
14955 template-id, then A can be a derived class of
14956 the deduced A. Likewise, if P is a pointer to
14957 a class of the form template-id, A can be a
14958 pointer to a derived class pointed to by the
14960 t = get_template_base (tparms, targs, parm, arg);
14966 else if (CLASSTYPE_TEMPLATE_INFO (arg)
14967 && (CLASSTYPE_TI_TEMPLATE (parm)
14968 == CLASSTYPE_TI_TEMPLATE (arg)))
14969 /* Perhaps PARM is something like S<U> and ARG is S<int>.
14970 Then, we should unify `int' and `U'. */
14973 /* There's no chance of unification succeeding. */
14976 return unify (tparms, targs, CLASSTYPE_TI_ARGS (parm),
14977 CLASSTYPE_TI_ARGS (t), UNIFY_ALLOW_NONE);
14979 else if (!same_type_ignoring_top_level_qualifiers_p (parm, arg))
14984 case FUNCTION_TYPE:
14986 unsigned int nargs;
14991 if (TREE_CODE (arg) != TREE_CODE (parm))
14994 /* CV qualifications for methods can never be deduced, they must
14995 match exactly. We need to check them explicitly here,
14996 because type_unification_real treats them as any other
14997 cv-qualified parameter. */
14998 if (TREE_CODE (parm) == METHOD_TYPE
14999 && (!check_cv_quals_for_unify
15001 TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (arg))),
15002 TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (parm))))))
15005 if (unify (tparms, targs, TREE_TYPE (parm),
15006 TREE_TYPE (arg), UNIFY_ALLOW_NONE))
15009 nargs = list_length (TYPE_ARG_TYPES (arg));
15010 args = XALLOCAVEC (tree, nargs);
15011 for (a = TYPE_ARG_TYPES (arg), i = 0;
15012 a != NULL_TREE && a != void_list_node;
15013 a = TREE_CHAIN (a), ++i)
15014 args[i] = TREE_VALUE (a);
15017 return type_unification_real (tparms, targs, TYPE_ARG_TYPES (parm),
15018 args, nargs, 1, DEDUCE_EXACT,
15023 /* Unify a pointer to member with a pointer to member function, which
15024 deduces the type of the member as a function type. */
15025 if (TYPE_PTRMEMFUNC_P (arg))
15029 cp_cv_quals cv_quals;
15031 /* Check top-level cv qualifiers */
15032 if (!check_cv_quals_for_unify (UNIFY_ALLOW_NONE, arg, parm))
15035 if (unify (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
15036 TYPE_PTRMEMFUNC_OBJECT_TYPE (arg), UNIFY_ALLOW_NONE))
15039 /* Determine the type of the function we are unifying against. */
15040 method_type = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (arg));
15042 build_function_type (TREE_TYPE (method_type),
15043 TREE_CHAIN (TYPE_ARG_TYPES (method_type)));
15045 /* Extract the cv-qualifiers of the member function from the
15046 implicit object parameter and place them on the function
15047 type to be restored later. */
15049 cp_type_quals(TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (method_type))));
15050 fntype = build_qualified_type (fntype, cv_quals);
15051 return unify (tparms, targs, TREE_TYPE (parm), fntype, strict);
15054 if (TREE_CODE (arg) != OFFSET_TYPE)
15056 if (unify (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
15057 TYPE_OFFSET_BASETYPE (arg), UNIFY_ALLOW_NONE))
15059 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
15063 if (DECL_TEMPLATE_PARM_P (parm))
15064 return unify (tparms, targs, DECL_INITIAL (parm), arg, strict);
15065 if (arg != integral_constant_value (parm))
15070 case TEMPLATE_DECL:
15071 /* Matched cases are handled by the ARG == PARM test above. */
15075 /* A non-type template parameter that is a variable should be a
15076 an integral constant, in which case, it whould have been
15077 folded into its (constant) value. So we should not be getting
15078 a variable here. */
15079 gcc_unreachable ();
15081 case TYPE_ARGUMENT_PACK:
15082 case NONTYPE_ARGUMENT_PACK:
15084 tree packed_parms = ARGUMENT_PACK_ARGS (parm);
15085 tree packed_args = ARGUMENT_PACK_ARGS (arg);
15086 int i, len = TREE_VEC_LENGTH (packed_parms);
15087 int argslen = TREE_VEC_LENGTH (packed_args);
15088 int parm_variadic_p = 0;
15090 for (i = 0; i < len; ++i)
15092 if (PACK_EXPANSION_P (TREE_VEC_ELT (packed_parms, i)))
15095 /* We can unify against something with a trailing
15097 parm_variadic_p = 1;
15099 /* Since there is something following the pack
15100 expansion, we cannot unify this template argument
15107 /* If we don't have enough arguments to satisfy the parameters
15108 (not counting the pack expression at the end), or we have
15109 too many arguments for a parameter list that doesn't end in
15110 a pack expression, we can't unify. */
15111 if (argslen < (len - parm_variadic_p)
15112 || (argslen > len && !parm_variadic_p))
15115 /* Unify all of the parameters that precede the (optional)
15116 pack expression. */
15117 for (i = 0; i < len - parm_variadic_p; ++i)
15119 if (unify (tparms, targs, TREE_VEC_ELT (packed_parms, i),
15120 TREE_VEC_ELT (packed_args, i), strict))
15124 if (parm_variadic_p)
15125 return unify_pack_expansion (tparms, targs,
15126 packed_parms, packed_args,
15127 strict, /*call_args_p=*/false,
15135 case DECLTYPE_TYPE:
15136 /* Cannot deduce anything from TYPEOF_TYPE or DECLTYPE_TYPE
15141 /* Unification fails if we hit an error node. */
15145 gcc_assert (EXPR_P (parm));
15147 /* We must be looking at an expression. This can happen with
15151 void foo(S<I>, S<I + 2>);
15153 This is a "nondeduced context":
15157 The nondeduced contexts are:
15159 --A type that is a template-id in which one or more of
15160 the template-arguments is an expression that references
15161 a template-parameter.
15163 In these cases, we assume deduction succeeded, but don't
15164 actually infer any unifications. */
15166 if (!uses_template_parms (parm)
15167 && !template_args_equal (parm, arg))
15174 /* Note that DECL can be defined in this translation unit, if
15178 mark_definable (tree decl)
15181 DECL_NOT_REALLY_EXTERN (decl) = 1;
15182 FOR_EACH_CLONE (clone, decl)
15183 DECL_NOT_REALLY_EXTERN (clone) = 1;
15186 /* Called if RESULT is explicitly instantiated, or is a member of an
15187 explicitly instantiated class. */
15190 mark_decl_instantiated (tree result, int extern_p)
15192 SET_DECL_EXPLICIT_INSTANTIATION (result);
15194 /* If this entity has already been written out, it's too late to
15195 make any modifications. */
15196 if (TREE_ASM_WRITTEN (result))
15199 if (TREE_CODE (result) != FUNCTION_DECL)
15200 /* The TREE_PUBLIC flag for function declarations will have been
15201 set correctly by tsubst. */
15202 TREE_PUBLIC (result) = 1;
15204 /* This might have been set by an earlier implicit instantiation. */
15205 DECL_COMDAT (result) = 0;
15208 DECL_NOT_REALLY_EXTERN (result) = 0;
15211 mark_definable (result);
15212 /* Always make artificials weak. */
15213 if (DECL_ARTIFICIAL (result) && flag_weak)
15214 comdat_linkage (result);
15215 /* For WIN32 we also want to put explicit instantiations in
15216 linkonce sections. */
15217 else if (TREE_PUBLIC (result))
15218 maybe_make_one_only (result);
15221 /* If EXTERN_P, then this function will not be emitted -- unless
15222 followed by an explicit instantiation, at which point its linkage
15223 will be adjusted. If !EXTERN_P, then this function will be
15224 emitted here. In neither circumstance do we want
15225 import_export_decl to adjust the linkage. */
15226 DECL_INTERFACE_KNOWN (result) = 1;
15229 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
15230 important template arguments. If any are missing, we check whether
15231 they're important by using error_mark_node for substituting into any
15232 args that were used for partial ordering (the ones between ARGS and END)
15233 and seeing if it bubbles up. */
15236 check_undeduced_parms (tree targs, tree args, tree end)
15238 bool found = false;
15240 for (i = TREE_VEC_LENGTH (targs) - 1; i >= 0; --i)
15241 if (TREE_VEC_ELT (targs, i) == NULL_TREE)
15244 TREE_VEC_ELT (targs, i) = error_mark_node;
15248 for (; args != end; args = TREE_CHAIN (args))
15250 tree substed = tsubst (TREE_VALUE (args), targs, tf_none, NULL_TREE);
15251 if (substed == error_mark_node)
15258 /* Given two function templates PAT1 and PAT2, return:
15260 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
15261 -1 if PAT2 is more specialized than PAT1.
15262 0 if neither is more specialized.
15264 LEN indicates the number of parameters we should consider
15265 (defaulted parameters should not be considered).
15267 The 1998 std underspecified function template partial ordering, and
15268 DR214 addresses the issue. We take pairs of arguments, one from
15269 each of the templates, and deduce them against each other. One of
15270 the templates will be more specialized if all the *other*
15271 template's arguments deduce against its arguments and at least one
15272 of its arguments *does* *not* deduce against the other template's
15273 corresponding argument. Deduction is done as for class templates.
15274 The arguments used in deduction have reference and top level cv
15275 qualifiers removed. Iff both arguments were originally reference
15276 types *and* deduction succeeds in both directions, the template
15277 with the more cv-qualified argument wins for that pairing (if
15278 neither is more cv-qualified, they both are equal). Unlike regular
15279 deduction, after all the arguments have been deduced in this way,
15280 we do *not* verify the deduced template argument values can be
15281 substituted into non-deduced contexts.
15283 The logic can be a bit confusing here, because we look at deduce1 and
15284 targs1 to see if pat2 is at least as specialized, and vice versa; if we
15285 can find template arguments for pat1 to make arg1 look like arg2, that
15286 means that arg2 is at least as specialized as arg1. */
15289 more_specialized_fn (tree pat1, tree pat2, int len)
15291 tree decl1 = DECL_TEMPLATE_RESULT (pat1);
15292 tree decl2 = DECL_TEMPLATE_RESULT (pat2);
15293 tree targs1 = make_tree_vec (DECL_NTPARMS (pat1));
15294 tree targs2 = make_tree_vec (DECL_NTPARMS (pat2));
15295 tree tparms1 = DECL_INNERMOST_TEMPLATE_PARMS (pat1);
15296 tree tparms2 = DECL_INNERMOST_TEMPLATE_PARMS (pat2);
15297 tree args1 = TYPE_ARG_TYPES (TREE_TYPE (decl1));
15298 tree args2 = TYPE_ARG_TYPES (TREE_TYPE (decl2));
15299 tree origs1, origs2;
15300 bool lose1 = false;
15301 bool lose2 = false;
15303 /* Remove the this parameter from non-static member functions. If
15304 one is a non-static member function and the other is not a static
15305 member function, remove the first parameter from that function
15306 also. This situation occurs for operator functions where we
15307 locate both a member function (with this pointer) and non-member
15308 operator (with explicit first operand). */
15309 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl1))
15311 len--; /* LEN is the number of significant arguments for DECL1 */
15312 args1 = TREE_CHAIN (args1);
15313 if (!DECL_STATIC_FUNCTION_P (decl2))
15314 args2 = TREE_CHAIN (args2);
15316 else if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl2))
15318 args2 = TREE_CHAIN (args2);
15319 if (!DECL_STATIC_FUNCTION_P (decl1))
15322 args1 = TREE_CHAIN (args1);
15326 /* If only one is a conversion operator, they are unordered. */
15327 if (DECL_CONV_FN_P (decl1) != DECL_CONV_FN_P (decl2))
15330 /* Consider the return type for a conversion function */
15331 if (DECL_CONV_FN_P (decl1))
15333 args1 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl1)), args1);
15334 args2 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl2)), args2);
15338 processing_template_decl++;
15344 /* Stop when an ellipsis is seen. */
15345 && args1 != NULL_TREE && args2 != NULL_TREE)
15347 tree arg1 = TREE_VALUE (args1);
15348 tree arg2 = TREE_VALUE (args2);
15349 int deduce1, deduce2;
15353 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
15354 && TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
15356 /* When both arguments are pack expansions, we need only
15357 unify the patterns themselves. */
15358 arg1 = PACK_EXPANSION_PATTERN (arg1);
15359 arg2 = PACK_EXPANSION_PATTERN (arg2);
15361 /* This is the last comparison we need to do. */
15365 if (TREE_CODE (arg1) == REFERENCE_TYPE)
15367 arg1 = TREE_TYPE (arg1);
15368 quals1 = cp_type_quals (arg1);
15371 if (TREE_CODE (arg2) == REFERENCE_TYPE)
15373 arg2 = TREE_TYPE (arg2);
15374 quals2 = cp_type_quals (arg2);
15377 if ((quals1 < 0) != (quals2 < 0))
15379 /* Only of the args is a reference, see if we should apply
15380 array/function pointer decay to it. This is not part of
15381 DR214, but is, IMHO, consistent with the deduction rules
15382 for the function call itself, and with our earlier
15383 implementation of the underspecified partial ordering
15384 rules. (nathan). */
15387 switch (TREE_CODE (arg1))
15390 arg1 = TREE_TYPE (arg1);
15392 case FUNCTION_TYPE:
15393 arg1 = build_pointer_type (arg1);
15402 switch (TREE_CODE (arg2))
15405 arg2 = TREE_TYPE (arg2);
15407 case FUNCTION_TYPE:
15408 arg2 = build_pointer_type (arg2);
15417 arg1 = TYPE_MAIN_VARIANT (arg1);
15418 arg2 = TYPE_MAIN_VARIANT (arg2);
15420 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION)
15422 int i, len2 = list_length (args2);
15423 tree parmvec = make_tree_vec (1);
15424 tree argvec = make_tree_vec (len2);
15427 /* Setup the parameter vector, which contains only ARG1. */
15428 TREE_VEC_ELT (parmvec, 0) = arg1;
15430 /* Setup the argument vector, which contains the remaining
15432 for (i = 0; i < len2; i++, ta = TREE_CHAIN (ta))
15433 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
15435 deduce1 = !unify_pack_expansion (tparms1, targs1, parmvec,
15436 argvec, UNIFY_ALLOW_NONE,
15437 /*call_args_p=*/false,
15440 /* We cannot deduce in the other direction, because ARG1 is
15441 a pack expansion but ARG2 is not. */
15444 else if (TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
15446 int i, len1 = list_length (args1);
15447 tree parmvec = make_tree_vec (1);
15448 tree argvec = make_tree_vec (len1);
15451 /* Setup the parameter vector, which contains only ARG1. */
15452 TREE_VEC_ELT (parmvec, 0) = arg2;
15454 /* Setup the argument vector, which contains the remaining
15456 for (i = 0; i < len1; i++, ta = TREE_CHAIN (ta))
15457 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
15459 deduce2 = !unify_pack_expansion (tparms2, targs2, parmvec,
15460 argvec, UNIFY_ALLOW_NONE,
15461 /*call_args_p=*/false,
15464 /* We cannot deduce in the other direction, because ARG2 is
15465 a pack expansion but ARG1 is not.*/
15471 /* The normal case, where neither argument is a pack
15473 deduce1 = !unify (tparms1, targs1, arg1, arg2, UNIFY_ALLOW_NONE);
15474 deduce2 = !unify (tparms2, targs2, arg2, arg1, UNIFY_ALLOW_NONE);
15477 /* If we couldn't deduce arguments for tparms1 to make arg1 match
15478 arg2, then arg2 is not as specialized as arg1. */
15484 /* "If, for a given type, deduction succeeds in both directions
15485 (i.e., the types are identical after the transformations above)
15486 and if the type from the argument template is more cv-qualified
15487 than the type from the parameter template (as described above)
15488 that type is considered to be more specialized than the other. If
15489 neither type is more cv-qualified than the other then neither type
15490 is more specialized than the other." */
15492 if (deduce1 && deduce2
15493 && quals1 != quals2 && quals1 >= 0 && quals2 >= 0)
15495 if ((quals1 & quals2) == quals2)
15497 if ((quals1 & quals2) == quals1)
15501 if (lose1 && lose2)
15502 /* We've failed to deduce something in either direction.
15503 These must be unordered. */
15506 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
15507 || TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
15508 /* We have already processed all of the arguments in our
15509 handing of the pack expansion type. */
15512 args1 = TREE_CHAIN (args1);
15513 args2 = TREE_CHAIN (args2);
15516 /* "In most cases, all template parameters must have values in order for
15517 deduction to succeed, but for partial ordering purposes a template
15518 parameter may remain without a value provided it is not used in the
15519 types being used for partial ordering."
15521 Thus, if we are missing any of the targs1 we need to substitute into
15522 origs1, then pat2 is not as specialized as pat1. This can happen when
15523 there is a nondeduced context. */
15524 if (!lose2 && check_undeduced_parms (targs1, origs1, args1))
15526 if (!lose1 && check_undeduced_parms (targs2, origs2, args2))
15529 processing_template_decl--;
15531 /* All things being equal, if the next argument is a pack expansion
15532 for one function but not for the other, prefer the
15533 non-variadic function. FIXME this is bogus; see c++/41958. */
15535 && args1 && TREE_VALUE (args1)
15536 && args2 && TREE_VALUE (args2))
15538 lose1 = TREE_CODE (TREE_VALUE (args1)) == TYPE_PACK_EXPANSION;
15539 lose2 = TREE_CODE (TREE_VALUE (args2)) == TYPE_PACK_EXPANSION;
15542 if (lose1 == lose2)
15550 /* Determine which of two partial specializations is more specialized.
15552 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
15553 to the first partial specialization. The TREE_VALUE is the
15554 innermost set of template parameters for the partial
15555 specialization. PAT2 is similar, but for the second template.
15557 Return 1 if the first partial specialization is more specialized;
15558 -1 if the second is more specialized; 0 if neither is more
15561 See [temp.class.order] for information about determining which of
15562 two templates is more specialized. */
15565 more_specialized_class (tree pat1, tree pat2)
15570 bool any_deductions = false;
15572 tmpl1 = TREE_TYPE (pat1);
15573 tmpl2 = TREE_TYPE (pat2);
15575 /* Just like what happens for functions, if we are ordering between
15576 different class template specializations, we may encounter dependent
15577 types in the arguments, and we need our dependency check functions
15578 to behave correctly. */
15579 ++processing_template_decl;
15580 targs = get_class_bindings (TREE_VALUE (pat1),
15581 CLASSTYPE_TI_ARGS (tmpl1),
15582 CLASSTYPE_TI_ARGS (tmpl2));
15586 any_deductions = true;
15589 targs = get_class_bindings (TREE_VALUE (pat2),
15590 CLASSTYPE_TI_ARGS (tmpl2),
15591 CLASSTYPE_TI_ARGS (tmpl1));
15595 any_deductions = true;
15597 --processing_template_decl;
15599 /* In the case of a tie where at least one of the class templates
15600 has a parameter pack at the end, the template with the most
15601 non-packed parameters wins. */
15604 && (template_args_variadic_p (TREE_PURPOSE (pat1))
15605 || template_args_variadic_p (TREE_PURPOSE (pat2))))
15607 tree args1 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat1));
15608 tree args2 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat2));
15609 int len1 = TREE_VEC_LENGTH (args1);
15610 int len2 = TREE_VEC_LENGTH (args2);
15612 /* We don't count the pack expansion at the end. */
15613 if (template_args_variadic_p (TREE_PURPOSE (pat1)))
15615 if (template_args_variadic_p (TREE_PURPOSE (pat2)))
15620 else if (len1 < len2)
15627 /* Return the template arguments that will produce the function signature
15628 DECL from the function template FN, with the explicit template
15629 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
15630 also match. Return NULL_TREE if no satisfactory arguments could be
15634 get_bindings (tree fn, tree decl, tree explicit_args, bool check_rettype)
15636 int ntparms = DECL_NTPARMS (fn);
15637 tree targs = make_tree_vec (ntparms);
15639 tree decl_arg_types;
15641 unsigned int nargs, ix;
15644 /* Substitute the explicit template arguments into the type of DECL.
15645 The call to fn_type_unification will handle substitution into the
15647 decl_type = TREE_TYPE (decl);
15648 if (explicit_args && uses_template_parms (decl_type))
15651 tree converted_args;
15653 if (DECL_TEMPLATE_INFO (decl))
15654 tmpl = DECL_TI_TEMPLATE (decl);
15656 /* We can get here for some invalid specializations. */
15660 = coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
15661 explicit_args, NULL_TREE,
15663 /*require_all_args=*/false,
15664 /*use_default_args=*/false);
15665 if (converted_args == error_mark_node)
15668 decl_type = tsubst (decl_type, converted_args, tf_none, NULL_TREE);
15669 if (decl_type == error_mark_node)
15673 /* Never do unification on the 'this' parameter. */
15674 decl_arg_types = skip_artificial_parms_for (decl,
15675 TYPE_ARG_TYPES (decl_type));
15677 nargs = list_length (decl_arg_types);
15678 args = XALLOCAVEC (tree, nargs);
15679 for (arg = decl_arg_types, ix = 0;
15680 arg != NULL_TREE && arg != void_list_node;
15681 arg = TREE_CHAIN (arg), ++ix)
15682 args[ix] = TREE_VALUE (arg);
15684 if (fn_type_unification (fn, explicit_args, targs,
15686 (check_rettype || DECL_CONV_FN_P (fn)
15687 ? TREE_TYPE (decl_type) : NULL_TREE),
15688 DEDUCE_EXACT, LOOKUP_NORMAL))
15694 /* Return the innermost template arguments that, when applied to a
15695 template specialization whose innermost template parameters are
15696 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
15699 For example, suppose we have:
15701 template <class T, class U> struct S {};
15702 template <class T> struct S<T*, int> {};
15704 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
15705 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
15706 int}. The resulting vector will be {double}, indicating that `T'
15707 is bound to `double'. */
15710 get_class_bindings (tree tparms, tree spec_args, tree args)
15712 int i, ntparms = TREE_VEC_LENGTH (tparms);
15714 tree innermost_deduced_args;
15716 innermost_deduced_args = make_tree_vec (ntparms);
15717 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
15719 deduced_args = copy_node (args);
15720 SET_TMPL_ARGS_LEVEL (deduced_args,
15721 TMPL_ARGS_DEPTH (deduced_args),
15722 innermost_deduced_args);
15725 deduced_args = innermost_deduced_args;
15727 if (unify (tparms, deduced_args,
15728 INNERMOST_TEMPLATE_ARGS (spec_args),
15729 INNERMOST_TEMPLATE_ARGS (args),
15733 for (i = 0; i < ntparms; ++i)
15734 if (! TREE_VEC_ELT (innermost_deduced_args, i))
15737 /* Verify that nondeduced template arguments agree with the type
15738 obtained from argument deduction.
15742 struct A { typedef int X; };
15743 template <class T, class U> struct C {};
15744 template <class T> struct C<T, typename T::X> {};
15746 Then with the instantiation `C<A, int>', we can deduce that
15747 `T' is `A' but unify () does not check whether `typename T::X'
15749 spec_args = tsubst (spec_args, deduced_args, tf_none, NULL_TREE);
15750 if (spec_args == error_mark_node
15751 /* We only need to check the innermost arguments; the other
15752 arguments will always agree. */
15753 || !comp_template_args (INNERMOST_TEMPLATE_ARGS (spec_args),
15754 INNERMOST_TEMPLATE_ARGS (args)))
15757 /* Now that we have bindings for all of the template arguments,
15758 ensure that the arguments deduced for the template template
15759 parameters have compatible template parameter lists. See the use
15760 of template_template_parm_bindings_ok_p in fn_type_unification
15761 for more information. */
15762 if (!template_template_parm_bindings_ok_p (tparms, deduced_args))
15765 return deduced_args;
15768 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
15769 Return the TREE_LIST node with the most specialized template, if
15770 any. If there is no most specialized template, the error_mark_node
15773 Note that this function does not look at, or modify, the
15774 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
15775 returned is one of the elements of INSTANTIATIONS, callers may
15776 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
15777 and retrieve it from the value returned. */
15780 most_specialized_instantiation (tree templates)
15784 ++processing_template_decl;
15787 for (fn = TREE_CHAIN (templates); fn; fn = TREE_CHAIN (fn))
15791 if (get_bindings (TREE_VALUE (champ),
15792 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
15793 NULL_TREE, /*check_ret=*/false))
15796 if (get_bindings (TREE_VALUE (fn),
15797 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
15798 NULL_TREE, /*check_ret=*/false))
15805 /* Equally specialized, move to next function. If there
15806 is no next function, nothing's most specialized. */
15807 fn = TREE_CHAIN (fn);
15815 /* Now verify that champ is better than everything earlier in the
15816 instantiation list. */
15817 for (fn = templates; fn != champ; fn = TREE_CHAIN (fn))
15818 if (get_bindings (TREE_VALUE (champ),
15819 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
15820 NULL_TREE, /*check_ret=*/false)
15821 || !get_bindings (TREE_VALUE (fn),
15822 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
15823 NULL_TREE, /*check_ret=*/false))
15829 processing_template_decl--;
15832 return error_mark_node;
15837 /* If DECL is a specialization of some template, return the most
15838 general such template. Otherwise, returns NULL_TREE.
15840 For example, given:
15842 template <class T> struct S { template <class U> void f(U); };
15844 if TMPL is `template <class U> void S<int>::f(U)' this will return
15845 the full template. This function will not trace past partial
15846 specializations, however. For example, given in addition:
15848 template <class T> struct S<T*> { template <class U> void f(U); };
15850 if TMPL is `template <class U> void S<int*>::f(U)' this will return
15851 `template <class T> template <class U> S<T*>::f(U)'. */
15854 most_general_template (tree decl)
15856 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
15857 an immediate specialization. */
15858 if (TREE_CODE (decl) == FUNCTION_DECL)
15860 if (DECL_TEMPLATE_INFO (decl)) {
15861 decl = DECL_TI_TEMPLATE (decl);
15863 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
15864 template friend. */
15865 if (TREE_CODE (decl) != TEMPLATE_DECL)
15871 /* Look for more and more general templates. */
15872 while (DECL_TEMPLATE_INFO (decl))
15874 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
15875 (See cp-tree.h for details.) */
15876 if (TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
15879 if (CLASS_TYPE_P (TREE_TYPE (decl))
15880 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)))
15883 /* Stop if we run into an explicitly specialized class template. */
15884 if (!DECL_NAMESPACE_SCOPE_P (decl)
15885 && DECL_CONTEXT (decl)
15886 && CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (decl)))
15889 decl = DECL_TI_TEMPLATE (decl);
15895 /* Return the most specialized of the class template partial
15896 specializations of TMPL which can produce TYPE, a specialization of
15897 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
15898 a _TYPE node corresponding to the partial specialization, while the
15899 TREE_PURPOSE is the set of template arguments that must be
15900 substituted into the TREE_TYPE in order to generate TYPE.
15902 If the choice of partial specialization is ambiguous, a diagnostic
15903 is issued, and the error_mark_node is returned. If there are no
15904 partial specializations of TMPL matching TYPE, then NULL_TREE is
15908 most_specialized_class (tree type, tree tmpl)
15910 tree list = NULL_TREE;
15916 tree outer_args = NULL_TREE;
15918 tmpl = most_general_template (tmpl);
15919 args = CLASSTYPE_TI_ARGS (type);
15921 /* For determining which partial specialization to use, only the
15922 innermost args are interesting. */
15923 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
15925 outer_args = strip_innermost_template_args (args, 1);
15926 args = INNERMOST_TEMPLATE_ARGS (args);
15929 for (t = DECL_TEMPLATE_SPECIALIZATIONS (tmpl); t; t = TREE_CHAIN (t))
15931 tree partial_spec_args;
15933 tree parms = TREE_VALUE (t);
15935 partial_spec_args = CLASSTYPE_TI_ARGS (TREE_TYPE (t));
15940 ++processing_template_decl;
15942 /* Discard the outer levels of args, and then substitute in the
15943 template args from the enclosing class. */
15944 partial_spec_args = INNERMOST_TEMPLATE_ARGS (partial_spec_args);
15945 partial_spec_args = tsubst_template_args
15946 (partial_spec_args, outer_args, tf_none, NULL_TREE);
15948 /* PARMS already refers to just the innermost parms, but the
15949 template parms in partial_spec_args had their levels lowered
15950 by tsubst, so we need to do the same for the parm list. We
15951 can't just tsubst the TREE_VEC itself, as tsubst wants to
15952 treat a TREE_VEC as an argument vector. */
15953 parms = copy_node (parms);
15954 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
15955 TREE_VEC_ELT (parms, i) =
15956 tsubst (TREE_VEC_ELT (parms, i), outer_args, tf_none, NULL_TREE);
15958 --processing_template_decl;
15961 partial_spec_args =
15962 coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
15963 add_to_template_args (outer_args,
15964 partial_spec_args),
15966 /*require_all_args=*/true,
15967 /*use_default_args=*/true);
15969 if (partial_spec_args == error_mark_node)
15970 return error_mark_node;
15972 spec_args = get_class_bindings (parms,
15978 spec_args = add_to_template_args (outer_args, spec_args);
15979 list = tree_cons (spec_args, TREE_VALUE (t), list);
15980 TREE_TYPE (list) = TREE_TYPE (t);
15987 ambiguous_p = false;
15990 t = TREE_CHAIN (t);
15991 for (; t; t = TREE_CHAIN (t))
15993 fate = more_specialized_class (champ, t);
16000 t = TREE_CHAIN (t);
16003 ambiguous_p = true;
16012 for (t = list; t && t != champ; t = TREE_CHAIN (t))
16014 fate = more_specialized_class (champ, t);
16017 ambiguous_p = true;
16025 char *spaces = NULL;
16026 error ("ambiguous class template instantiation for %q#T", type);
16027 str = TREE_CHAIN (list) ? _("candidates are:") : _("candidate is:");
16028 for (t = list; t; t = TREE_CHAIN (t))
16030 error ("%s %+#T", spaces ? spaces : str, TREE_TYPE (t));
16031 spaces = spaces ? spaces : get_spaces (str);
16034 return error_mark_node;
16040 /* Explicitly instantiate DECL. */
16043 do_decl_instantiation (tree decl, tree storage)
16045 tree result = NULL_TREE;
16048 if (!decl || decl == error_mark_node)
16049 /* An error occurred, for which grokdeclarator has already issued
16050 an appropriate message. */
16052 else if (! DECL_LANG_SPECIFIC (decl))
16054 error ("explicit instantiation of non-template %q#D", decl);
16057 else if (TREE_CODE (decl) == VAR_DECL)
16059 /* There is an asymmetry here in the way VAR_DECLs and
16060 FUNCTION_DECLs are handled by grokdeclarator. In the case of
16061 the latter, the DECL we get back will be marked as a
16062 template instantiation, and the appropriate
16063 DECL_TEMPLATE_INFO will be set up. This does not happen for
16064 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
16065 should handle VAR_DECLs as it currently handles
16067 if (!DECL_CLASS_SCOPE_P (decl))
16069 error ("%qD is not a static data member of a class template", decl);
16072 result = lookup_field (DECL_CONTEXT (decl), DECL_NAME (decl), 0, false);
16073 if (!result || TREE_CODE (result) != VAR_DECL)
16075 error ("no matching template for %qD found", decl);
16078 if (!same_type_p (TREE_TYPE (result), TREE_TYPE (decl)))
16080 error ("type %qT for explicit instantiation %qD does not match "
16081 "declared type %qT", TREE_TYPE (result), decl,
16086 else if (TREE_CODE (decl) != FUNCTION_DECL)
16088 error ("explicit instantiation of %q#D", decl);
16094 /* Check for various error cases. Note that if the explicit
16095 instantiation is valid the RESULT will currently be marked as an
16096 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
16097 until we get here. */
16099 if (DECL_TEMPLATE_SPECIALIZATION (result))
16101 /* DR 259 [temp.spec].
16103 Both an explicit instantiation and a declaration of an explicit
16104 specialization shall not appear in a program unless the explicit
16105 instantiation follows a declaration of the explicit specialization.
16107 For a given set of template parameters, if an explicit
16108 instantiation of a template appears after a declaration of an
16109 explicit specialization for that template, the explicit
16110 instantiation has no effect. */
16113 else if (DECL_EXPLICIT_INSTANTIATION (result))
16117 No program shall explicitly instantiate any template more
16120 We check DECL_NOT_REALLY_EXTERN so as not to complain when
16121 the first instantiation was `extern' and the second is not,
16122 and EXTERN_P for the opposite case. */
16123 if (DECL_NOT_REALLY_EXTERN (result) && !extern_p)
16124 permerror (input_location, "duplicate explicit instantiation of %q#D", result);
16125 /* If an "extern" explicit instantiation follows an ordinary
16126 explicit instantiation, the template is instantiated. */
16130 else if (!DECL_IMPLICIT_INSTANTIATION (result))
16132 error ("no matching template for %qD found", result);
16135 else if (!DECL_TEMPLATE_INFO (result))
16137 permerror (input_location, "explicit instantiation of non-template %q#D", result);
16141 if (storage == NULL_TREE)
16143 else if (storage == ridpointers[(int) RID_EXTERN])
16145 if (!in_system_header && (cxx_dialect == cxx98))
16146 pedwarn (input_location, OPT_pedantic,
16147 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
16152 error ("storage class %qD applied to template instantiation", storage);
16154 check_explicit_instantiation_namespace (result);
16155 mark_decl_instantiated (result, extern_p);
16157 instantiate_decl (result, /*defer_ok=*/1,
16158 /*expl_inst_class_mem_p=*/false);
16162 mark_class_instantiated (tree t, int extern_p)
16164 SET_CLASSTYPE_EXPLICIT_INSTANTIATION (t);
16165 SET_CLASSTYPE_INTERFACE_KNOWN (t);
16166 CLASSTYPE_INTERFACE_ONLY (t) = extern_p;
16167 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (t)) = extern_p;
16170 CLASSTYPE_DEBUG_REQUESTED (t) = 1;
16171 rest_of_type_compilation (t, 1);
16175 /* Called from do_type_instantiation through binding_table_foreach to
16176 do recursive instantiation for the type bound in ENTRY. */
16178 bt_instantiate_type_proc (binding_entry entry, void *data)
16180 tree storage = *(tree *) data;
16182 if (MAYBE_CLASS_TYPE_P (entry->type)
16183 && !uses_template_parms (CLASSTYPE_TI_ARGS (entry->type)))
16184 do_type_instantiation (TYPE_MAIN_DECL (entry->type), storage, 0);
16187 /* Called from do_type_instantiation to instantiate a member
16188 (a member function or a static member variable) of an
16189 explicitly instantiated class template. */
16191 instantiate_class_member (tree decl, int extern_p)
16193 mark_decl_instantiated (decl, extern_p);
16195 instantiate_decl (decl, /*defer_ok=*/1,
16196 /*expl_inst_class_mem_p=*/true);
16199 /* Perform an explicit instantiation of template class T. STORAGE, if
16200 non-null, is the RID for extern, inline or static. COMPLAIN is
16201 nonzero if this is called from the parser, zero if called recursively,
16202 since the standard is unclear (as detailed below). */
16205 do_type_instantiation (tree t, tree storage, tsubst_flags_t complain)
16210 int previous_instantiation_extern_p = 0;
16212 if (TREE_CODE (t) == TYPE_DECL)
16215 if (! CLASS_TYPE_P (t) || ! CLASSTYPE_TEMPLATE_INFO (t))
16217 error ("explicit instantiation of non-template type %qT", t);
16223 if (!COMPLETE_TYPE_P (t))
16225 if (complain & tf_error)
16226 error ("explicit instantiation of %q#T before definition of template",
16231 if (storage != NULL_TREE)
16233 if (!in_system_header)
16235 if (storage == ridpointers[(int) RID_EXTERN])
16237 if (cxx_dialect == cxx98)
16238 pedwarn (input_location, OPT_pedantic,
16239 "ISO C++ 1998 forbids the use of %<extern%> on "
16240 "explicit instantiations");
16243 pedwarn (input_location, OPT_pedantic,
16244 "ISO C++ forbids the use of %qE"
16245 " on explicit instantiations", storage);
16248 if (storage == ridpointers[(int) RID_INLINE])
16250 else if (storage == ridpointers[(int) RID_EXTERN])
16252 else if (storage == ridpointers[(int) RID_STATIC])
16256 error ("storage class %qD applied to template instantiation",
16262 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (t))
16264 /* DR 259 [temp.spec].
16266 Both an explicit instantiation and a declaration of an explicit
16267 specialization shall not appear in a program unless the explicit
16268 instantiation follows a declaration of the explicit specialization.
16270 For a given set of template parameters, if an explicit
16271 instantiation of a template appears after a declaration of an
16272 explicit specialization for that template, the explicit
16273 instantiation has no effect. */
16276 else if (CLASSTYPE_EXPLICIT_INSTANTIATION (t))
16280 No program shall explicitly instantiate any template more
16283 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
16284 instantiation was `extern'. If EXTERN_P then the second is.
16285 These cases are OK. */
16286 previous_instantiation_extern_p = CLASSTYPE_INTERFACE_ONLY (t);
16288 if (!previous_instantiation_extern_p && !extern_p
16289 && (complain & tf_error))
16290 permerror (input_location, "duplicate explicit instantiation of %q#T", t);
16292 /* If we've already instantiated the template, just return now. */
16293 if (!CLASSTYPE_INTERFACE_ONLY (t))
16297 check_explicit_instantiation_namespace (TYPE_NAME (t));
16298 mark_class_instantiated (t, extern_p);
16306 /* In contrast to implicit instantiation, where only the
16307 declarations, and not the definitions, of members are
16308 instantiated, we have here:
16312 The explicit instantiation of a class template specialization
16313 implies the instantiation of all of its members not
16314 previously explicitly specialized in the translation unit
16315 containing the explicit instantiation.
16317 Of course, we can't instantiate member template classes, since
16318 we don't have any arguments for them. Note that the standard
16319 is unclear on whether the instantiation of the members are
16320 *explicit* instantiations or not. However, the most natural
16321 interpretation is that it should be an explicit instantiation. */
16324 for (tmp = TYPE_METHODS (t); tmp; tmp = TREE_CHAIN (tmp))
16325 if (TREE_CODE (tmp) == FUNCTION_DECL
16326 && DECL_TEMPLATE_INSTANTIATION (tmp))
16327 instantiate_class_member (tmp, extern_p);
16329 for (tmp = TYPE_FIELDS (t); tmp; tmp = TREE_CHAIN (tmp))
16330 if (TREE_CODE (tmp) == VAR_DECL && DECL_TEMPLATE_INSTANTIATION (tmp))
16331 instantiate_class_member (tmp, extern_p);
16333 if (CLASSTYPE_NESTED_UTDS (t))
16334 binding_table_foreach (CLASSTYPE_NESTED_UTDS (t),
16335 bt_instantiate_type_proc, &storage);
16339 /* Given a function DECL, which is a specialization of TMPL, modify
16340 DECL to be a re-instantiation of TMPL with the same template
16341 arguments. TMPL should be the template into which tsubst'ing
16342 should occur for DECL, not the most general template.
16344 One reason for doing this is a scenario like this:
16347 void f(const T&, int i);
16349 void g() { f(3, 7); }
16352 void f(const T& t, const int i) { }
16354 Note that when the template is first instantiated, with
16355 instantiate_template, the resulting DECL will have no name for the
16356 first parameter, and the wrong type for the second. So, when we go
16357 to instantiate the DECL, we regenerate it. */
16360 regenerate_decl_from_template (tree decl, tree tmpl)
16362 /* The arguments used to instantiate DECL, from the most general
16367 args = DECL_TI_ARGS (decl);
16368 code_pattern = DECL_TEMPLATE_RESULT (tmpl);
16370 /* Make sure that we can see identifiers, and compute access
16372 push_access_scope (decl);
16374 if (TREE_CODE (decl) == FUNCTION_DECL)
16382 args_depth = TMPL_ARGS_DEPTH (args);
16383 parms_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
16384 if (args_depth > parms_depth)
16385 args = get_innermost_template_args (args, parms_depth);
16387 specs = tsubst_exception_specification (TREE_TYPE (code_pattern),
16388 args, tf_error, NULL_TREE);
16390 TREE_TYPE (decl) = build_exception_variant (TREE_TYPE (decl),
16393 /* Merge parameter declarations. */
16394 decl_parm = skip_artificial_parms_for (decl,
16395 DECL_ARGUMENTS (decl));
16397 = skip_artificial_parms_for (code_pattern,
16398 DECL_ARGUMENTS (code_pattern));
16399 while (decl_parm && !FUNCTION_PARAMETER_PACK_P (pattern_parm))
16404 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
16405 DECL_NAME (decl_parm) = DECL_NAME (pattern_parm);
16406 parm_type = tsubst (TREE_TYPE (pattern_parm), args, tf_error,
16408 parm_type = type_decays_to (parm_type);
16409 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
16410 TREE_TYPE (decl_parm) = parm_type;
16411 attributes = DECL_ATTRIBUTES (pattern_parm);
16412 if (DECL_ATTRIBUTES (decl_parm) != attributes)
16414 DECL_ATTRIBUTES (decl_parm) = attributes;
16415 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
16417 decl_parm = TREE_CHAIN (decl_parm);
16418 pattern_parm = TREE_CHAIN (pattern_parm);
16420 /* Merge any parameters that match with the function parameter
16422 if (pattern_parm && FUNCTION_PARAMETER_PACK_P (pattern_parm))
16425 tree expanded_types;
16426 /* Expand the TYPE_PACK_EXPANSION that provides the types for
16427 the parameters in this function parameter pack. */
16428 expanded_types = tsubst_pack_expansion (TREE_TYPE (pattern_parm),
16429 args, tf_error, NULL_TREE);
16430 len = TREE_VEC_LENGTH (expanded_types);
16431 for (i = 0; i < len; i++)
16436 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
16437 /* Rename the parameter to include the index. */
16438 DECL_NAME (decl_parm) =
16439 make_ith_pack_parameter_name (DECL_NAME (pattern_parm), i);
16440 parm_type = TREE_VEC_ELT (expanded_types, i);
16441 parm_type = type_decays_to (parm_type);
16442 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
16443 TREE_TYPE (decl_parm) = parm_type;
16444 attributes = DECL_ATTRIBUTES (pattern_parm);
16445 if (DECL_ATTRIBUTES (decl_parm) != attributes)
16447 DECL_ATTRIBUTES (decl_parm) = attributes;
16448 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
16450 decl_parm = TREE_CHAIN (decl_parm);
16453 /* Merge additional specifiers from the CODE_PATTERN. */
16454 if (DECL_DECLARED_INLINE_P (code_pattern)
16455 && !DECL_DECLARED_INLINE_P (decl))
16456 DECL_DECLARED_INLINE_P (decl) = 1;
16458 else if (TREE_CODE (decl) == VAR_DECL)
16459 DECL_INITIAL (decl) =
16460 tsubst_expr (DECL_INITIAL (code_pattern), args,
16461 tf_error, DECL_TI_TEMPLATE (decl),
16462 /*integral_constant_expression_p=*/false);
16464 gcc_unreachable ();
16466 pop_access_scope (decl);
16469 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
16470 substituted to get DECL. */
16473 template_for_substitution (tree decl)
16475 tree tmpl = DECL_TI_TEMPLATE (decl);
16477 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
16478 for the instantiation. This is not always the most general
16479 template. Consider, for example:
16482 struct S { template <class U> void f();
16483 template <> void f<int>(); };
16485 and an instantiation of S<double>::f<int>. We want TD to be the
16486 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
16487 while (/* An instantiation cannot have a definition, so we need a
16488 more general template. */
16489 DECL_TEMPLATE_INSTANTIATION (tmpl)
16490 /* We must also deal with friend templates. Given:
16492 template <class T> struct S {
16493 template <class U> friend void f() {};
16496 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
16497 so far as the language is concerned, but that's still
16498 where we get the pattern for the instantiation from. On
16499 other hand, if the definition comes outside the class, say:
16501 template <class T> struct S {
16502 template <class U> friend void f();
16504 template <class U> friend void f() {}
16506 we don't need to look any further. That's what the check for
16507 DECL_INITIAL is for. */
16508 || (TREE_CODE (decl) == FUNCTION_DECL
16509 && DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION (tmpl)
16510 && !DECL_INITIAL (DECL_TEMPLATE_RESULT (tmpl))))
16512 /* The present template, TD, should not be a definition. If it
16513 were a definition, we should be using it! Note that we
16514 cannot restructure the loop to just keep going until we find
16515 a template with a definition, since that might go too far if
16516 a specialization was declared, but not defined. */
16517 gcc_assert (TREE_CODE (decl) != VAR_DECL
16518 || DECL_IN_AGGR_P (DECL_TEMPLATE_RESULT (tmpl)));
16520 /* Fetch the more general template. */
16521 tmpl = DECL_TI_TEMPLATE (tmpl);
16527 /* Returns true if we need to instantiate this template instance even if we
16528 know we aren't going to emit it.. */
16531 always_instantiate_p (tree decl)
16533 /* We always instantiate inline functions so that we can inline them. An
16534 explicit instantiation declaration prohibits implicit instantiation of
16535 non-inline functions. With high levels of optimization, we would
16536 normally inline non-inline functions -- but we're not allowed to do
16537 that for "extern template" functions. Therefore, we check
16538 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
16539 return ((TREE_CODE (decl) == FUNCTION_DECL
16540 && DECL_DECLARED_INLINE_P (decl))
16541 /* And we need to instantiate static data members so that
16542 their initializers are available in integral constant
16544 || (TREE_CODE (decl) == VAR_DECL
16545 && DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (decl)));
16548 /* Produce the definition of D, a _DECL generated from a template. If
16549 DEFER_OK is nonzero, then we don't have to actually do the
16550 instantiation now; we just have to do it sometime. Normally it is
16551 an error if this is an explicit instantiation but D is undefined.
16552 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
16553 explicitly instantiated class template. */
16556 instantiate_decl (tree d, int defer_ok,
16557 bool expl_inst_class_mem_p)
16559 tree tmpl = DECL_TI_TEMPLATE (d);
16566 bool pattern_defined;
16568 location_t saved_loc = input_location;
16571 /* This function should only be used to instantiate templates for
16572 functions and static member variables. */
16573 gcc_assert (TREE_CODE (d) == FUNCTION_DECL
16574 || TREE_CODE (d) == VAR_DECL);
16576 /* Variables are never deferred; if instantiation is required, they
16577 are instantiated right away. That allows for better code in the
16578 case that an expression refers to the value of the variable --
16579 if the variable has a constant value the referring expression can
16580 take advantage of that fact. */
16581 if (TREE_CODE (d) == VAR_DECL)
16584 /* Don't instantiate cloned functions. Instead, instantiate the
16585 functions they cloned. */
16586 if (TREE_CODE (d) == FUNCTION_DECL && DECL_CLONED_FUNCTION_P (d))
16587 d = DECL_CLONED_FUNCTION (d);
16589 if (DECL_TEMPLATE_INSTANTIATED (d)
16590 || DECL_TEMPLATE_SPECIALIZATION (d))
16591 /* D has already been instantiated or explicitly specialized, so
16592 there's nothing for us to do here.
16594 It might seem reasonable to check whether or not D is an explicit
16595 instantiation, and, if so, stop here. But when an explicit
16596 instantiation is deferred until the end of the compilation,
16597 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
16598 the instantiation. */
16601 /* Check to see whether we know that this template will be
16602 instantiated in some other file, as with "extern template"
16604 external_p = (DECL_INTERFACE_KNOWN (d) && DECL_REALLY_EXTERN (d));
16606 /* In general, we do not instantiate such templates. */
16607 if (external_p && !always_instantiate_p (d))
16610 gen_tmpl = most_general_template (tmpl);
16611 gen_args = DECL_TI_ARGS (d);
16613 if (tmpl != gen_tmpl)
16614 /* We should already have the extra args. */
16615 gcc_assert (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (gen_tmpl))
16616 == TMPL_ARGS_DEPTH (gen_args));
16617 /* And what's in the hash table should match D. */
16618 gcc_assert ((spec = retrieve_specialization (gen_tmpl, gen_args, 0)) == d
16619 || spec == NULL_TREE);
16621 /* This needs to happen before any tsubsting. */
16622 if (! push_tinst_level (d))
16625 timevar_push (TV_PARSE);
16627 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
16628 for the instantiation. */
16629 td = template_for_substitution (d);
16630 code_pattern = DECL_TEMPLATE_RESULT (td);
16632 /* We should never be trying to instantiate a member of a class
16633 template or partial specialization. */
16634 gcc_assert (d != code_pattern);
16636 if ((DECL_NAMESPACE_SCOPE_P (d) && !DECL_INITIALIZED_IN_CLASS_P (d))
16637 || DECL_TEMPLATE_SPECIALIZATION (td))
16638 /* In the case of a friend template whose definition is provided
16639 outside the class, we may have too many arguments. Drop the
16640 ones we don't need. The same is true for specializations. */
16641 args = get_innermost_template_args
16642 (gen_args, TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (td)));
16646 if (TREE_CODE (d) == FUNCTION_DECL)
16647 pattern_defined = (DECL_SAVED_TREE (code_pattern) != NULL_TREE);
16649 pattern_defined = ! DECL_IN_AGGR_P (code_pattern);
16651 /* We may be in the middle of deferred access check. Disable it now. */
16652 push_deferring_access_checks (dk_no_deferred);
16654 /* Unless an explicit instantiation directive has already determined
16655 the linkage of D, remember that a definition is available for
16657 if (pattern_defined
16658 && !DECL_INTERFACE_KNOWN (d)
16659 && !DECL_NOT_REALLY_EXTERN (d))
16660 mark_definable (d);
16662 input_location = DECL_SOURCE_LOCATION (d);
16664 /* If D is a member of an explicitly instantiated class template,
16665 and no definition is available, treat it like an implicit
16667 if (!pattern_defined && expl_inst_class_mem_p
16668 && DECL_EXPLICIT_INSTANTIATION (d))
16670 DECL_NOT_REALLY_EXTERN (d) = 0;
16671 DECL_INTERFACE_KNOWN (d) = 0;
16672 SET_DECL_IMPLICIT_INSTANTIATION (d);
16675 /* Recheck the substitutions to obtain any warning messages
16676 about ignoring cv qualifiers. Don't do this for artificial decls,
16677 as it breaks the context-sensitive substitution for lambda op(). */
16678 if (!defer_ok && !DECL_ARTIFICIAL (d))
16680 tree gen = DECL_TEMPLATE_RESULT (gen_tmpl);
16681 tree type = TREE_TYPE (gen);
16683 /* Make sure that we can see identifiers, and compute access
16684 correctly. D is already the target FUNCTION_DECL with the
16686 push_access_scope (d);
16688 if (TREE_CODE (gen) == FUNCTION_DECL)
16690 tsubst (DECL_ARGUMENTS (gen), gen_args, tf_warning_or_error, d);
16691 tsubst_exception_specification (type, gen_args, tf_warning_or_error,
16693 /* Don't simply tsubst the function type, as that will give
16694 duplicate warnings about poor parameter qualifications.
16695 The function arguments are the same as the decl_arguments
16696 without the top level cv qualifiers. */
16697 type = TREE_TYPE (type);
16699 tsubst (type, gen_args, tf_warning_or_error, d);
16701 pop_access_scope (d);
16704 /* Defer all other templates, unless we have been explicitly
16705 forbidden from doing so. */
16706 if (/* If there is no definition, we cannot instantiate the
16709 /* If it's OK to postpone instantiation, do so. */
16711 /* If this is a static data member that will be defined
16712 elsewhere, we don't want to instantiate the entire data
16713 member, but we do want to instantiate the initializer so that
16714 we can substitute that elsewhere. */
16715 || (external_p && TREE_CODE (d) == VAR_DECL))
16717 /* The definition of the static data member is now required so
16718 we must substitute the initializer. */
16719 if (TREE_CODE (d) == VAR_DECL
16720 && !DECL_INITIAL (d)
16721 && DECL_INITIAL (code_pattern))
16726 ns = decl_namespace_context (d);
16727 push_nested_namespace (ns);
16728 push_nested_class (DECL_CONTEXT (d));
16729 init = tsubst_expr (DECL_INITIAL (code_pattern),
16731 tf_warning_or_error, NULL_TREE,
16732 /*integral_constant_expression_p=*/false);
16733 cp_finish_decl (d, init, /*init_const_expr_p=*/false,
16734 /*asmspec_tree=*/NULL_TREE,
16735 LOOKUP_ONLYCONVERTING);
16736 pop_nested_class ();
16737 pop_nested_namespace (ns);
16740 /* We restore the source position here because it's used by
16741 add_pending_template. */
16742 input_location = saved_loc;
16744 if (at_eof && !pattern_defined
16745 && DECL_EXPLICIT_INSTANTIATION (d)
16746 && DECL_NOT_REALLY_EXTERN (d))
16749 The definition of a non-exported function template, a
16750 non-exported member function template, or a non-exported
16751 member function or static data member of a class template
16752 shall be present in every translation unit in which it is
16753 explicitly instantiated. */
16754 permerror (input_location, "explicit instantiation of %qD "
16755 "but no definition available", d);
16757 /* ??? Historically, we have instantiated inline functions, even
16758 when marked as "extern template". */
16759 if (!(external_p && TREE_CODE (d) == VAR_DECL))
16760 add_pending_template (d);
16763 /* Tell the repository that D is available in this translation unit
16764 -- and see if it is supposed to be instantiated here. */
16765 if (TREE_PUBLIC (d) && !DECL_REALLY_EXTERN (d) && !repo_emit_p (d))
16767 /* In a PCH file, despite the fact that the repository hasn't
16768 requested instantiation in the PCH it is still possible that
16769 an instantiation will be required in a file that includes the
16772 add_pending_template (d);
16773 /* Instantiate inline functions so that the inliner can do its
16774 job, even though we'll not be emitting a copy of this
16776 if (!(TREE_CODE (d) == FUNCTION_DECL && possibly_inlined_p (d)))
16780 need_push = !cfun || !global_bindings_p ();
16782 push_to_top_level ();
16784 /* Mark D as instantiated so that recursive calls to
16785 instantiate_decl do not try to instantiate it again. */
16786 DECL_TEMPLATE_INSTANTIATED (d) = 1;
16788 /* Regenerate the declaration in case the template has been modified
16789 by a subsequent redeclaration. */
16790 regenerate_decl_from_template (d, td);
16792 /* We already set the file and line above. Reset them now in case
16793 they changed as a result of calling regenerate_decl_from_template. */
16794 input_location = DECL_SOURCE_LOCATION (d);
16796 if (TREE_CODE (d) == VAR_DECL)
16800 /* Clear out DECL_RTL; whatever was there before may not be right
16801 since we've reset the type of the declaration. */
16802 SET_DECL_RTL (d, NULL_RTX);
16803 DECL_IN_AGGR_P (d) = 0;
16805 /* The initializer is placed in DECL_INITIAL by
16806 regenerate_decl_from_template. Pull it out so that
16807 cp_finish_decl can process it. */
16808 init = DECL_INITIAL (d);
16809 DECL_INITIAL (d) = NULL_TREE;
16810 DECL_INITIALIZED_P (d) = 0;
16812 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
16813 initializer. That function will defer actual emission until
16814 we have a chance to determine linkage. */
16815 DECL_EXTERNAL (d) = 0;
16817 /* Enter the scope of D so that access-checking works correctly. */
16818 push_nested_class (DECL_CONTEXT (d));
16819 cp_finish_decl (d, init, false, NULL_TREE, 0);
16820 pop_nested_class ();
16822 else if (TREE_CODE (d) == FUNCTION_DECL)
16824 htab_t saved_local_specializations;
16829 /* Save away the current list, in case we are instantiating one
16830 template from within the body of another. */
16831 saved_local_specializations = local_specializations;
16833 /* Set up the list of local specializations. */
16834 local_specializations = htab_create (37,
16835 hash_local_specialization,
16836 eq_local_specializations,
16839 /* Set up context. */
16840 start_preparsed_function (d, NULL_TREE, SF_PRE_PARSED);
16842 /* Create substitution entries for the parameters. */
16843 subst_decl = DECL_TEMPLATE_RESULT (template_for_substitution (d));
16844 tmpl_parm = DECL_ARGUMENTS (subst_decl);
16845 spec_parm = DECL_ARGUMENTS (d);
16846 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (d))
16848 register_local_specialization (spec_parm, tmpl_parm);
16849 spec_parm = skip_artificial_parms_for (d, spec_parm);
16850 tmpl_parm = skip_artificial_parms_for (subst_decl, tmpl_parm);
16852 while (tmpl_parm && !FUNCTION_PARAMETER_PACK_P (tmpl_parm))
16854 register_local_specialization (spec_parm, tmpl_parm);
16855 tmpl_parm = TREE_CHAIN (tmpl_parm);
16856 spec_parm = TREE_CHAIN (spec_parm);
16858 if (tmpl_parm && FUNCTION_PARAMETER_PACK_P (tmpl_parm))
16860 /* Register the (value) argument pack as a specialization of
16861 TMPL_PARM, then move on. */
16862 tree argpack = make_fnparm_pack (spec_parm);
16863 register_local_specialization (argpack, tmpl_parm);
16864 tmpl_parm = TREE_CHAIN (tmpl_parm);
16865 spec_parm = NULL_TREE;
16867 gcc_assert (!spec_parm);
16869 /* Substitute into the body of the function. */
16870 tsubst_expr (DECL_SAVED_TREE (code_pattern), args,
16871 tf_warning_or_error, tmpl,
16872 /*integral_constant_expression_p=*/false);
16874 /* Set the current input_location to the end of the function
16875 so that finish_function knows where we are. */
16876 input_location = DECL_STRUCT_FUNCTION (code_pattern)->function_end_locus;
16878 /* We don't need the local specializations any more. */
16879 htab_delete (local_specializations);
16880 local_specializations = saved_local_specializations;
16882 /* Finish the function. */
16883 d = finish_function (0);
16884 expand_or_defer_fn (d);
16887 /* We're not deferring instantiation any more. */
16888 TI_PENDING_TEMPLATE_FLAG (DECL_TEMPLATE_INFO (d)) = 0;
16891 pop_from_top_level ();
16894 input_location = saved_loc;
16895 pop_deferring_access_checks ();
16896 pop_tinst_level ();
16898 timevar_pop (TV_PARSE);
16903 /* Run through the list of templates that we wish we could
16904 instantiate, and instantiate any we can. RETRIES is the
16905 number of times we retry pending template instantiation. */
16908 instantiate_pending_templates (int retries)
16911 location_t saved_loc = input_location;
16913 /* Instantiating templates may trigger vtable generation. This in turn
16914 may require further template instantiations. We place a limit here
16915 to avoid infinite loop. */
16916 if (pending_templates && retries >= max_tinst_depth)
16918 tree decl = pending_templates->tinst->decl;
16920 error ("template instantiation depth exceeds maximum of %d"
16921 " instantiating %q+D, possibly from virtual table generation"
16922 " (use -ftemplate-depth= to increase the maximum)",
16923 max_tinst_depth, decl);
16924 if (TREE_CODE (decl) == FUNCTION_DECL)
16925 /* Pretend that we defined it. */
16926 DECL_INITIAL (decl) = error_mark_node;
16932 struct pending_template **t = &pending_templates;
16933 struct pending_template *last = NULL;
16937 tree instantiation = reopen_tinst_level ((*t)->tinst);
16938 bool complete = false;
16940 if (TYPE_P (instantiation))
16944 if (!COMPLETE_TYPE_P (instantiation))
16946 instantiate_class_template (instantiation);
16947 if (CLASSTYPE_TEMPLATE_INSTANTIATION (instantiation))
16948 for (fn = TYPE_METHODS (instantiation);
16950 fn = TREE_CHAIN (fn))
16951 if (! DECL_ARTIFICIAL (fn))
16952 instantiate_decl (fn,
16954 /*expl_inst_class_mem_p=*/false);
16955 if (COMPLETE_TYPE_P (instantiation))
16959 complete = COMPLETE_TYPE_P (instantiation);
16963 if (!DECL_TEMPLATE_SPECIALIZATION (instantiation)
16964 && !DECL_TEMPLATE_INSTANTIATED (instantiation))
16967 = instantiate_decl (instantiation,
16969 /*expl_inst_class_mem_p=*/false);
16970 if (DECL_TEMPLATE_INSTANTIATED (instantiation))
16974 complete = (DECL_TEMPLATE_SPECIALIZATION (instantiation)
16975 || DECL_TEMPLATE_INSTANTIATED (instantiation));
16979 /* If INSTANTIATION has been instantiated, then we don't
16980 need to consider it again in the future. */
16988 current_tinst_level = NULL;
16990 last_pending_template = last;
16992 while (reconsider);
16994 input_location = saved_loc;
16997 /* Substitute ARGVEC into T, which is a list of initializers for
16998 either base class or a non-static data member. The TREE_PURPOSEs
16999 are DECLs, and the TREE_VALUEs are the initializer values. Used by
17000 instantiate_decl. */
17003 tsubst_initializer_list (tree t, tree argvec)
17005 tree inits = NULL_TREE;
17007 for (; t; t = TREE_CHAIN (t))
17011 tree expanded_bases = NULL_TREE;
17012 tree expanded_arguments = NULL_TREE;
17015 if (TREE_CODE (TREE_PURPOSE (t)) == TYPE_PACK_EXPANSION)
17020 /* Expand the base class expansion type into separate base
17022 expanded_bases = tsubst_pack_expansion (TREE_PURPOSE (t), argvec,
17023 tf_warning_or_error,
17025 if (expanded_bases == error_mark_node)
17028 /* We'll be building separate TREE_LISTs of arguments for
17030 len = TREE_VEC_LENGTH (expanded_bases);
17031 expanded_arguments = make_tree_vec (len);
17032 for (i = 0; i < len; i++)
17033 TREE_VEC_ELT (expanded_arguments, i) = NULL_TREE;
17035 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
17036 expand each argument in the TREE_VALUE of t. */
17037 expr = make_node (EXPR_PACK_EXPANSION);
17038 PACK_EXPANSION_PARAMETER_PACKS (expr) =
17039 PACK_EXPANSION_PARAMETER_PACKS (TREE_PURPOSE (t));
17041 if (TREE_VALUE (t) == void_type_node)
17042 /* VOID_TYPE_NODE is used to indicate
17043 value-initialization. */
17045 for (i = 0; i < len; i++)
17046 TREE_VEC_ELT (expanded_arguments, i) = void_type_node;
17050 /* Substitute parameter packs into each argument in the
17052 in_base_initializer = 1;
17053 for (arg = TREE_VALUE (t); arg; arg = TREE_CHAIN (arg))
17055 tree expanded_exprs;
17057 /* Expand the argument. */
17058 SET_PACK_EXPANSION_PATTERN (expr, TREE_VALUE (arg));
17060 = tsubst_pack_expansion (expr, argvec,
17061 tf_warning_or_error,
17063 if (expanded_exprs == error_mark_node)
17066 /* Prepend each of the expanded expressions to the
17067 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
17068 for (i = 0; i < len; i++)
17070 TREE_VEC_ELT (expanded_arguments, i) =
17071 tree_cons (NULL_TREE,
17072 TREE_VEC_ELT (expanded_exprs, i),
17073 TREE_VEC_ELT (expanded_arguments, i));
17076 in_base_initializer = 0;
17078 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
17079 since we built them backwards. */
17080 for (i = 0; i < len; i++)
17082 TREE_VEC_ELT (expanded_arguments, i) =
17083 nreverse (TREE_VEC_ELT (expanded_arguments, i));
17088 for (i = 0; i < len; ++i)
17090 if (expanded_bases)
17092 decl = TREE_VEC_ELT (expanded_bases, i);
17093 decl = expand_member_init (decl);
17094 init = TREE_VEC_ELT (expanded_arguments, i);
17098 decl = tsubst_copy (TREE_PURPOSE (t), argvec,
17099 tf_warning_or_error, NULL_TREE);
17101 decl = expand_member_init (decl);
17102 if (decl && !DECL_P (decl))
17103 in_base_initializer = 1;
17105 init = tsubst_expr (TREE_VALUE (t), argvec,
17106 tf_warning_or_error, NULL_TREE,
17107 /*integral_constant_expression_p=*/false);
17108 in_base_initializer = 0;
17113 init = build_tree_list (decl, init);
17114 TREE_CHAIN (init) = inits;
17122 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
17125 set_current_access_from_decl (tree decl)
17127 if (TREE_PRIVATE (decl))
17128 current_access_specifier = access_private_node;
17129 else if (TREE_PROTECTED (decl))
17130 current_access_specifier = access_protected_node;
17132 current_access_specifier = access_public_node;
17135 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
17136 is the instantiation (which should have been created with
17137 start_enum) and ARGS are the template arguments to use. */
17140 tsubst_enum (tree tag, tree newtag, tree args)
17144 for (e = TYPE_VALUES (tag); e; e = TREE_CHAIN (e))
17149 decl = TREE_VALUE (e);
17150 /* Note that in a template enum, the TREE_VALUE is the
17151 CONST_DECL, not the corresponding INTEGER_CST. */
17152 value = tsubst_expr (DECL_INITIAL (decl),
17153 args, tf_warning_or_error, NULL_TREE,
17154 /*integral_constant_expression_p=*/true);
17156 /* Give this enumeration constant the correct access. */
17157 set_current_access_from_decl (decl);
17159 /* Actually build the enumerator itself. */
17160 build_enumerator (DECL_NAME (decl), value, newtag);
17163 finish_enum (newtag);
17164 DECL_SOURCE_LOCATION (TYPE_NAME (newtag))
17165 = DECL_SOURCE_LOCATION (TYPE_NAME (tag));
17168 /* DECL is a FUNCTION_DECL that is a template specialization. Return
17169 its type -- but without substituting the innermost set of template
17170 arguments. So, innermost set of template parameters will appear in
17174 get_mostly_instantiated_function_type (tree decl)
17182 tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
17183 targs = DECL_TI_ARGS (decl);
17184 tparms = DECL_TEMPLATE_PARMS (tmpl);
17185 parm_depth = TMPL_PARMS_DEPTH (tparms);
17187 /* There should be as many levels of arguments as there are levels
17189 gcc_assert (parm_depth == TMPL_ARGS_DEPTH (targs));
17191 fn_type = TREE_TYPE (tmpl);
17193 if (parm_depth == 1)
17194 /* No substitution is necessary. */
17198 int i, save_access_control;
17201 /* Replace the innermost level of the TARGS with NULL_TREEs to
17202 let tsubst know not to substitute for those parameters. */
17203 partial_args = make_tree_vec (TREE_VEC_LENGTH (targs));
17204 for (i = 1; i < TMPL_ARGS_DEPTH (targs); ++i)
17205 SET_TMPL_ARGS_LEVEL (partial_args, i,
17206 TMPL_ARGS_LEVEL (targs, i));
17207 SET_TMPL_ARGS_LEVEL (partial_args,
17208 TMPL_ARGS_DEPTH (targs),
17209 make_tree_vec (DECL_NTPARMS (tmpl)));
17211 /* Disable access control as this function is used only during
17213 save_access_control = flag_access_control;
17214 flag_access_control = 0;
17216 ++processing_template_decl;
17217 /* Now, do the (partial) substitution to figure out the
17218 appropriate function type. */
17219 fn_type = tsubst (fn_type, partial_args, tf_error, NULL_TREE);
17220 --processing_template_decl;
17222 /* Substitute into the template parameters to obtain the real
17223 innermost set of parameters. This step is important if the
17224 innermost set of template parameters contains value
17225 parameters whose types depend on outer template parameters. */
17226 TREE_VEC_LENGTH (partial_args)--;
17227 tparms = tsubst_template_parms (tparms, partial_args, tf_error);
17229 flag_access_control = save_access_control;
17235 /* Return truthvalue if we're processing a template different from
17236 the last one involved in diagnostics. */
17238 problematic_instantiation_changed (void)
17240 return last_template_error_tick != tinst_level_tick;
17243 /* Remember current template involved in diagnostics. */
17245 record_last_problematic_instantiation (void)
17247 last_template_error_tick = tinst_level_tick;
17250 struct tinst_level *
17251 current_instantiation (void)
17253 return current_tinst_level;
17256 /* [temp.param] Check that template non-type parm TYPE is of an allowable
17257 type. Return zero for ok, nonzero for disallowed. Issue error and
17258 warning messages under control of COMPLAIN. */
17261 invalid_nontype_parm_type_p (tree type, tsubst_flags_t complain)
17263 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
17265 else if (POINTER_TYPE_P (type))
17267 else if (TYPE_PTR_TO_MEMBER_P (type))
17269 else if (TREE_CODE (type) == TEMPLATE_TYPE_PARM)
17271 else if (TREE_CODE (type) == TYPENAME_TYPE)
17274 if (complain & tf_error)
17275 error ("%q#T is not a valid type for a template constant parameter", type);
17279 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
17280 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
17283 dependent_type_p_r (tree type)
17289 A type is dependent if it is:
17291 -- a template parameter. Template template parameters are types
17292 for us (since TYPE_P holds true for them) so we handle
17294 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
17295 || TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM)
17297 /* -- a qualified-id with a nested-name-specifier which contains a
17298 class-name that names a dependent type or whose unqualified-id
17299 names a dependent type. */
17300 if (TREE_CODE (type) == TYPENAME_TYPE)
17302 /* -- a cv-qualified type where the cv-unqualified type is
17304 type = TYPE_MAIN_VARIANT (type);
17305 /* -- a compound type constructed from any dependent type. */
17306 if (TYPE_PTR_TO_MEMBER_P (type))
17307 return (dependent_type_p (TYPE_PTRMEM_CLASS_TYPE (type))
17308 || dependent_type_p (TYPE_PTRMEM_POINTED_TO_TYPE
17310 else if (TREE_CODE (type) == POINTER_TYPE
17311 || TREE_CODE (type) == REFERENCE_TYPE)
17312 return dependent_type_p (TREE_TYPE (type));
17313 else if (TREE_CODE (type) == FUNCTION_TYPE
17314 || TREE_CODE (type) == METHOD_TYPE)
17318 if (dependent_type_p (TREE_TYPE (type)))
17320 for (arg_type = TYPE_ARG_TYPES (type);
17322 arg_type = TREE_CHAIN (arg_type))
17323 if (dependent_type_p (TREE_VALUE (arg_type)))
17327 /* -- an array type constructed from any dependent type or whose
17328 size is specified by a constant expression that is
17329 value-dependent. */
17330 if (TREE_CODE (type) == ARRAY_TYPE)
17332 if (TYPE_DOMAIN (type)
17333 && dependent_type_p (TYPE_DOMAIN (type)))
17335 return dependent_type_p (TREE_TYPE (type));
17337 else if (TREE_CODE (type) == INTEGER_TYPE
17338 && !TREE_CONSTANT (TYPE_MAX_VALUE (type)))
17340 /* If this is the TYPE_DOMAIN of an array type, consider it
17341 dependent. We already checked for value-dependence in
17342 compute_array_index_type. */
17343 return type_dependent_expression_p (TYPE_MAX_VALUE (type));
17346 /* -- a template-id in which either the template name is a template
17348 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
17350 /* ... or any of the template arguments is a dependent type or
17351 an expression that is type-dependent or value-dependent. */
17352 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INFO (type)
17353 && (any_dependent_template_arguments_p
17354 (INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type)))))
17357 /* All TYPEOF_TYPEs and DECLTYPE_TYPEs are dependent; if the
17358 argument of the `typeof' expression is not type-dependent, then
17359 it should already been have resolved. */
17360 if (TREE_CODE (type) == TYPEOF_TYPE
17361 || TREE_CODE (type) == DECLTYPE_TYPE)
17364 /* A template argument pack is dependent if any of its packed
17366 if (TREE_CODE (type) == TYPE_ARGUMENT_PACK)
17368 tree args = ARGUMENT_PACK_ARGS (type);
17369 int i, len = TREE_VEC_LENGTH (args);
17370 for (i = 0; i < len; ++i)
17371 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
17375 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
17376 be template parameters. */
17377 if (TREE_CODE (type) == TYPE_PACK_EXPANSION)
17380 /* The standard does not specifically mention types that are local
17381 to template functions or local classes, but they should be
17382 considered dependent too. For example:
17384 template <int I> void f() {
17389 The size of `E' cannot be known until the value of `I' has been
17390 determined. Therefore, `E' must be considered dependent. */
17391 scope = TYPE_CONTEXT (type);
17392 if (scope && TYPE_P (scope))
17393 return dependent_type_p (scope);
17394 else if (scope && TREE_CODE (scope) == FUNCTION_DECL)
17395 return type_dependent_expression_p (scope);
17397 /* Other types are non-dependent. */
17401 /* Returns TRUE if TYPE is dependent, in the sense of
17402 [temp.dep.type]. */
17405 dependent_type_p (tree type)
17407 /* If there are no template parameters in scope, then there can't be
17408 any dependent types. */
17409 if (!processing_template_decl)
17411 /* If we are not processing a template, then nobody should be
17412 providing us with a dependent type. */
17414 gcc_assert (TREE_CODE (type) != TEMPLATE_TYPE_PARM || is_auto (type));
17418 /* If the type is NULL, we have not computed a type for the entity
17419 in question; in that case, the type is dependent. */
17423 /* Erroneous types can be considered non-dependent. */
17424 if (type == error_mark_node)
17427 /* If we have not already computed the appropriate value for TYPE,
17429 if (!TYPE_DEPENDENT_P_VALID (type))
17431 TYPE_DEPENDENT_P (type) = dependent_type_p_r (type);
17432 TYPE_DEPENDENT_P_VALID (type) = 1;
17435 return TYPE_DEPENDENT_P (type);
17438 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
17439 lookup. In other words, a dependent type that is not the current
17443 dependent_scope_p (tree scope)
17445 return (scope && TYPE_P (scope) && dependent_type_p (scope)
17446 && !currently_open_class (scope));
17449 /* Returns TRUE if EXPRESSION is dependent, according to CRITERION. */
17452 dependent_scope_ref_p (tree expression, bool criterion (tree))
17457 gcc_assert (TREE_CODE (expression) == SCOPE_REF);
17459 if (!TYPE_P (TREE_OPERAND (expression, 0)))
17462 scope = TREE_OPERAND (expression, 0);
17463 name = TREE_OPERAND (expression, 1);
17467 An id-expression is type-dependent if it contains a
17468 nested-name-specifier that contains a class-name that names a
17470 /* The suggested resolution to Core Issue 224 implies that if the
17471 qualifying type is the current class, then we must peek
17474 && currently_open_class (scope)
17475 && !criterion (name))
17477 if (dependent_type_p (scope))
17483 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
17484 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
17488 value_dependent_expression_p (tree expression)
17490 if (!processing_template_decl)
17493 /* A name declared with a dependent type. */
17494 if (DECL_P (expression) && type_dependent_expression_p (expression))
17497 switch (TREE_CODE (expression))
17499 case IDENTIFIER_NODE:
17500 /* A name that has not been looked up -- must be dependent. */
17503 case TEMPLATE_PARM_INDEX:
17504 /* A non-type template parm. */
17508 /* A non-type template parm. */
17509 if (DECL_TEMPLATE_PARM_P (expression))
17511 return value_dependent_expression_p (DECL_INITIAL (expression));
17514 /* A constant with integral or enumeration type and is initialized
17515 with an expression that is value-dependent. */
17516 if (DECL_INITIAL (expression)
17517 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (expression))
17518 && value_dependent_expression_p (DECL_INITIAL (expression)))
17522 case DYNAMIC_CAST_EXPR:
17523 case STATIC_CAST_EXPR:
17524 case CONST_CAST_EXPR:
17525 case REINTERPRET_CAST_EXPR:
17527 /* These expressions are value-dependent if the type to which
17528 the cast occurs is dependent or the expression being casted
17529 is value-dependent. */
17531 tree type = TREE_TYPE (expression);
17533 if (dependent_type_p (type))
17536 /* A functional cast has a list of operands. */
17537 expression = TREE_OPERAND (expression, 0);
17540 /* If there are no operands, it must be an expression such
17541 as "int()". This should not happen for aggregate types
17542 because it would form non-constant expressions. */
17543 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
17548 if (TREE_CODE (expression) == TREE_LIST)
17549 return any_value_dependent_elements_p (expression);
17551 return value_dependent_expression_p (expression);
17556 /* A `sizeof' expression is value-dependent if the operand is
17557 type-dependent or is a pack expansion. */
17558 expression = TREE_OPERAND (expression, 0);
17559 if (PACK_EXPANSION_P (expression))
17561 else if (TYPE_P (expression))
17562 return dependent_type_p (expression);
17563 return type_dependent_expression_p (expression);
17566 return dependent_scope_ref_p (expression, value_dependent_expression_p);
17568 case COMPONENT_REF:
17569 return (value_dependent_expression_p (TREE_OPERAND (expression, 0))
17570 || value_dependent_expression_p (TREE_OPERAND (expression, 1)));
17573 /* A CALL_EXPR may appear in a constant expression if it is a
17574 call to a builtin function, e.g., __builtin_constant_p. All
17575 such calls are value-dependent. */
17578 case NONTYPE_ARGUMENT_PACK:
17579 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
17580 is value-dependent. */
17582 tree values = ARGUMENT_PACK_ARGS (expression);
17583 int i, len = TREE_VEC_LENGTH (values);
17585 for (i = 0; i < len; ++i)
17586 if (value_dependent_expression_p (TREE_VEC_ELT (values, i)))
17594 tree type2 = TRAIT_EXPR_TYPE2 (expression);
17595 return (dependent_type_p (TRAIT_EXPR_TYPE1 (expression))
17596 || (type2 ? dependent_type_p (type2) : false));
17600 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
17601 || (value_dependent_expression_p (TREE_OPERAND (expression, 2))));
17604 /* A constant expression is value-dependent if any subexpression is
17605 value-dependent. */
17606 switch (TREE_CODE_CLASS (TREE_CODE (expression)))
17608 case tcc_reference:
17610 return (value_dependent_expression_p
17611 (TREE_OPERAND (expression, 0)));
17613 case tcc_comparison:
17615 return ((value_dependent_expression_p
17616 (TREE_OPERAND (expression, 0)))
17617 || (value_dependent_expression_p
17618 (TREE_OPERAND (expression, 1))));
17620 case tcc_expression:
17624 for (i = 0; i < TREE_OPERAND_LENGTH (expression); ++i)
17625 /* In some cases, some of the operands may be missing.
17626 (For example, in the case of PREDECREMENT_EXPR, the
17627 amount to increment by may be missing.) That doesn't
17628 make the expression dependent. */
17629 if (TREE_OPERAND (expression, i)
17630 && (value_dependent_expression_p
17631 (TREE_OPERAND (expression, i))))
17641 /* The expression is not value-dependent. */
17645 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
17646 [temp.dep.expr]. */
17649 type_dependent_expression_p (tree expression)
17651 if (!processing_template_decl)
17654 if (expression == error_mark_node)
17657 /* An unresolved name is always dependent. */
17658 if (TREE_CODE (expression) == IDENTIFIER_NODE
17659 || TREE_CODE (expression) == USING_DECL)
17662 /* Some expression forms are never type-dependent. */
17663 if (TREE_CODE (expression) == PSEUDO_DTOR_EXPR
17664 || TREE_CODE (expression) == SIZEOF_EXPR
17665 || TREE_CODE (expression) == ALIGNOF_EXPR
17666 || TREE_CODE (expression) == TRAIT_EXPR
17667 || TREE_CODE (expression) == TYPEID_EXPR
17668 || TREE_CODE (expression) == DELETE_EXPR
17669 || TREE_CODE (expression) == VEC_DELETE_EXPR
17670 || TREE_CODE (expression) == THROW_EXPR)
17673 /* The types of these expressions depends only on the type to which
17674 the cast occurs. */
17675 if (TREE_CODE (expression) == DYNAMIC_CAST_EXPR
17676 || TREE_CODE (expression) == STATIC_CAST_EXPR
17677 || TREE_CODE (expression) == CONST_CAST_EXPR
17678 || TREE_CODE (expression) == REINTERPRET_CAST_EXPR
17679 || TREE_CODE (expression) == CAST_EXPR)
17680 return dependent_type_p (TREE_TYPE (expression));
17682 /* The types of these expressions depends only on the type created
17683 by the expression. */
17684 if (TREE_CODE (expression) == NEW_EXPR
17685 || TREE_CODE (expression) == VEC_NEW_EXPR)
17687 /* For NEW_EXPR tree nodes created inside a template, either
17688 the object type itself or a TREE_LIST may appear as the
17690 tree type = TREE_OPERAND (expression, 1);
17691 if (TREE_CODE (type) == TREE_LIST)
17692 /* This is an array type. We need to check array dimensions
17694 return dependent_type_p (TREE_VALUE (TREE_PURPOSE (type)))
17695 || value_dependent_expression_p
17696 (TREE_OPERAND (TREE_VALUE (type), 1));
17698 return dependent_type_p (type);
17701 if (TREE_CODE (expression) == SCOPE_REF
17702 && dependent_scope_ref_p (expression,
17703 type_dependent_expression_p))
17706 if (TREE_CODE (expression) == FUNCTION_DECL
17707 && DECL_LANG_SPECIFIC (expression)
17708 && DECL_TEMPLATE_INFO (expression)
17709 && (any_dependent_template_arguments_p
17710 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (expression)))))
17713 if (TREE_CODE (expression) == TEMPLATE_DECL
17714 && !DECL_TEMPLATE_TEMPLATE_PARM_P (expression))
17717 if (TREE_CODE (expression) == STMT_EXPR)
17718 expression = stmt_expr_value_expr (expression);
17720 if (BRACE_ENCLOSED_INITIALIZER_P (expression))
17725 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), i, elt)
17727 if (type_dependent_expression_p (elt))
17733 if (TREE_TYPE (expression) == unknown_type_node)
17735 if (TREE_CODE (expression) == ADDR_EXPR)
17736 return type_dependent_expression_p (TREE_OPERAND (expression, 0));
17737 if (TREE_CODE (expression) == COMPONENT_REF
17738 || TREE_CODE (expression) == OFFSET_REF)
17740 if (type_dependent_expression_p (TREE_OPERAND (expression, 0)))
17742 expression = TREE_OPERAND (expression, 1);
17743 if (TREE_CODE (expression) == IDENTIFIER_NODE)
17746 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
17747 if (TREE_CODE (expression) == SCOPE_REF)
17750 if (TREE_CODE (expression) == BASELINK)
17751 expression = BASELINK_FUNCTIONS (expression);
17753 if (TREE_CODE (expression) == TEMPLATE_ID_EXPR)
17755 if (any_dependent_template_arguments_p
17756 (TREE_OPERAND (expression, 1)))
17758 expression = TREE_OPERAND (expression, 0);
17760 gcc_assert (TREE_CODE (expression) == OVERLOAD
17761 || TREE_CODE (expression) == FUNCTION_DECL);
17765 if (type_dependent_expression_p (OVL_CURRENT (expression)))
17767 expression = OVL_NEXT (expression);
17772 gcc_assert (TREE_CODE (expression) != TYPE_DECL);
17774 return (dependent_type_p (TREE_TYPE (expression)));
17777 /* Like type_dependent_expression_p, but it also works while not processing
17778 a template definition, i.e. during substitution or mangling. */
17781 type_dependent_expression_p_push (tree expr)
17784 ++processing_template_decl;
17785 b = type_dependent_expression_p (expr);
17786 --processing_template_decl;
17790 /* Returns TRUE if ARGS contains a type-dependent expression. */
17793 any_type_dependent_arguments_p (const VEC(tree,gc) *args)
17798 for (i = 0; VEC_iterate (tree, args, i, arg); ++i)
17800 if (type_dependent_expression_p (arg))
17806 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
17807 expressions) contains any value-dependent expressions. */
17810 any_value_dependent_elements_p (const_tree list)
17812 for (; list; list = TREE_CHAIN (list))
17813 if (value_dependent_expression_p (TREE_VALUE (list)))
17819 /* Returns TRUE if the ARG (a template argument) is dependent. */
17822 dependent_template_arg_p (tree arg)
17824 if (!processing_template_decl)
17827 if (TREE_CODE (arg) == TEMPLATE_DECL
17828 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
17829 return dependent_template_p (arg);
17830 else if (ARGUMENT_PACK_P (arg))
17832 tree args = ARGUMENT_PACK_ARGS (arg);
17833 int i, len = TREE_VEC_LENGTH (args);
17834 for (i = 0; i < len; ++i)
17836 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
17842 else if (TYPE_P (arg))
17843 return dependent_type_p (arg);
17845 return (type_dependent_expression_p (arg)
17846 || value_dependent_expression_p (arg));
17849 /* Returns true if ARGS (a collection of template arguments) contains
17850 any types that require structural equality testing. */
17853 any_template_arguments_need_structural_equality_p (tree args)
17860 if (args == error_mark_node)
17863 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
17865 tree level = TMPL_ARGS_LEVEL (args, i + 1);
17866 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
17868 tree arg = TREE_VEC_ELT (level, j);
17869 tree packed_args = NULL_TREE;
17872 if (ARGUMENT_PACK_P (arg))
17874 /* Look inside the argument pack. */
17875 packed_args = ARGUMENT_PACK_ARGS (arg);
17876 len = TREE_VEC_LENGTH (packed_args);
17879 for (k = 0; k < len; ++k)
17882 arg = TREE_VEC_ELT (packed_args, k);
17884 if (error_operand_p (arg))
17886 else if (TREE_CODE (arg) == TEMPLATE_DECL
17887 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
17889 else if (TYPE_P (arg) && TYPE_STRUCTURAL_EQUALITY_P (arg))
17891 else if (!TYPE_P (arg) && TREE_TYPE (arg)
17892 && TYPE_STRUCTURAL_EQUALITY_P (TREE_TYPE (arg)))
17901 /* Returns true if ARGS (a collection of template arguments) contains
17902 any dependent arguments. */
17905 any_dependent_template_arguments_p (const_tree args)
17912 if (args == error_mark_node)
17915 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
17917 const_tree level = TMPL_ARGS_LEVEL (args, i + 1);
17918 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
17919 if (dependent_template_arg_p (TREE_VEC_ELT (level, j)))
17926 /* Returns TRUE if the template TMPL is dependent. */
17929 dependent_template_p (tree tmpl)
17931 if (TREE_CODE (tmpl) == OVERLOAD)
17935 if (dependent_template_p (OVL_FUNCTION (tmpl)))
17937 tmpl = OVL_CHAIN (tmpl);
17942 /* Template template parameters are dependent. */
17943 if (DECL_TEMPLATE_TEMPLATE_PARM_P (tmpl)
17944 || TREE_CODE (tmpl) == TEMPLATE_TEMPLATE_PARM)
17946 /* So are names that have not been looked up. */
17947 if (TREE_CODE (tmpl) == SCOPE_REF
17948 || TREE_CODE (tmpl) == IDENTIFIER_NODE)
17950 /* So are member templates of dependent classes. */
17951 if (TYPE_P (CP_DECL_CONTEXT (tmpl)))
17952 return dependent_type_p (DECL_CONTEXT (tmpl));
17956 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
17959 dependent_template_id_p (tree tmpl, tree args)
17961 return (dependent_template_p (tmpl)
17962 || any_dependent_template_arguments_p (args));
17965 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
17969 dependent_omp_for_p (tree declv, tree initv, tree condv, tree incrv)
17973 if (!processing_template_decl)
17976 for (i = 0; i < TREE_VEC_LENGTH (declv); i++)
17978 tree decl = TREE_VEC_ELT (declv, i);
17979 tree init = TREE_VEC_ELT (initv, i);
17980 tree cond = TREE_VEC_ELT (condv, i);
17981 tree incr = TREE_VEC_ELT (incrv, i);
17983 if (type_dependent_expression_p (decl))
17986 if (init && type_dependent_expression_p (init))
17989 if (type_dependent_expression_p (cond))
17992 if (COMPARISON_CLASS_P (cond)
17993 && (type_dependent_expression_p (TREE_OPERAND (cond, 0))
17994 || type_dependent_expression_p (TREE_OPERAND (cond, 1))))
17997 if (TREE_CODE (incr) == MODOP_EXPR)
17999 if (type_dependent_expression_p (TREE_OPERAND (incr, 0))
18000 || type_dependent_expression_p (TREE_OPERAND (incr, 2)))
18003 else if (type_dependent_expression_p (incr))
18005 else if (TREE_CODE (incr) == MODIFY_EXPR)
18007 if (type_dependent_expression_p (TREE_OPERAND (incr, 0)))
18009 else if (BINARY_CLASS_P (TREE_OPERAND (incr, 1)))
18011 tree t = TREE_OPERAND (incr, 1);
18012 if (type_dependent_expression_p (TREE_OPERAND (t, 0))
18013 || type_dependent_expression_p (TREE_OPERAND (t, 1)))
18022 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
18023 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
18024 no such TYPE can be found. Note that this function peers inside
18025 uninstantiated templates and therefore should be used only in
18026 extremely limited situations. ONLY_CURRENT_P restricts this
18027 peering to the currently open classes hierarchy (which is required
18028 when comparing types). */
18031 resolve_typename_type (tree type, bool only_current_p)
18040 gcc_assert (TREE_CODE (type) == TYPENAME_TYPE);
18042 scope = TYPE_CONTEXT (type);
18043 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
18044 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
18045 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
18046 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
18047 identifier of the TYPENAME_TYPE anymore.
18048 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
18049 TYPENAME_TYPE instead, we avoid messing up with a possible
18050 typedef variant case. */
18051 name = TYPE_IDENTIFIER (TYPE_MAIN_VARIANT (type));
18053 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
18054 it first before we can figure out what NAME refers to. */
18055 if (TREE_CODE (scope) == TYPENAME_TYPE)
18056 scope = resolve_typename_type (scope, only_current_p);
18057 /* If we don't know what SCOPE refers to, then we cannot resolve the
18059 if (TREE_CODE (scope) == TYPENAME_TYPE)
18061 /* If the SCOPE is a template type parameter, we have no way of
18062 resolving the name. */
18063 if (TREE_CODE (scope) == TEMPLATE_TYPE_PARM)
18065 /* If the SCOPE is not the current instantiation, there's no reason
18066 to look inside it. */
18067 if (only_current_p && !currently_open_class (scope))
18069 /* If this is a typedef, we don't want to look inside (c++/11987). */
18070 if (typedef_variant_p (type))
18072 /* If SCOPE isn't the template itself, it will not have a valid
18073 TYPE_FIELDS list. */
18074 if (same_type_p (scope, CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope)))
18075 /* scope is either the template itself or a compatible instantiation
18076 like X<T>, so look up the name in the original template. */
18077 scope = CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope);
18079 /* scope is a partial instantiation, so we can't do the lookup or we
18080 will lose the template arguments. */
18082 /* Enter the SCOPE so that name lookup will be resolved as if we
18083 were in the class definition. In particular, SCOPE will no
18084 longer be considered a dependent type. */
18085 pushed_scope = push_scope (scope);
18086 /* Look up the declaration. */
18087 decl = lookup_member (scope, name, /*protect=*/0, /*want_type=*/true);
18089 result = NULL_TREE;
18091 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
18092 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
18095 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == IDENTIFIER_NODE
18096 && TREE_CODE (decl) == TYPE_DECL)
18098 result = TREE_TYPE (decl);
18099 if (result == error_mark_node)
18100 result = NULL_TREE;
18102 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == TEMPLATE_ID_EXPR
18103 && DECL_CLASS_TEMPLATE_P (decl))
18107 /* Obtain the template and the arguments. */
18108 tmpl = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 0);
18109 args = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 1);
18110 /* Instantiate the template. */
18111 result = lookup_template_class (tmpl, args, NULL_TREE, NULL_TREE,
18112 /*entering_scope=*/0,
18113 tf_error | tf_user);
18114 if (result == error_mark_node)
18115 result = NULL_TREE;
18118 /* Leave the SCOPE. */
18120 pop_scope (pushed_scope);
18122 /* If we failed to resolve it, return the original typename. */
18126 /* If lookup found a typename type, resolve that too. */
18127 if (TREE_CODE (result) == TYPENAME_TYPE && !TYPENAME_IS_RESOLVING_P (result))
18129 /* Ill-formed programs can cause infinite recursion here, so we
18130 must catch that. */
18131 TYPENAME_IS_RESOLVING_P (type) = 1;
18132 result = resolve_typename_type (result, only_current_p);
18133 TYPENAME_IS_RESOLVING_P (type) = 0;
18136 /* Qualify the resulting type. */
18137 quals = cp_type_quals (type);
18139 result = cp_build_qualified_type (result, cp_type_quals (result) | quals);
18144 /* EXPR is an expression which is not type-dependent. Return a proxy
18145 for EXPR that can be used to compute the types of larger
18146 expressions containing EXPR. */
18149 build_non_dependent_expr (tree expr)
18153 /* Preserve null pointer constants so that the type of things like
18154 "p == 0" where "p" is a pointer can be determined. */
18155 if (null_ptr_cst_p (expr))
18157 /* Preserve OVERLOADs; the functions must be available to resolve
18160 if (TREE_CODE (inner_expr) == STMT_EXPR)
18161 inner_expr = stmt_expr_value_expr (inner_expr);
18162 if (TREE_CODE (inner_expr) == ADDR_EXPR)
18163 inner_expr = TREE_OPERAND (inner_expr, 0);
18164 if (TREE_CODE (inner_expr) == COMPONENT_REF)
18165 inner_expr = TREE_OPERAND (inner_expr, 1);
18166 if (is_overloaded_fn (inner_expr)
18167 || TREE_CODE (inner_expr) == OFFSET_REF)
18169 /* There is no need to return a proxy for a variable. */
18170 if (TREE_CODE (expr) == VAR_DECL)
18172 /* Preserve string constants; conversions from string constants to
18173 "char *" are allowed, even though normally a "const char *"
18174 cannot be used to initialize a "char *". */
18175 if (TREE_CODE (expr) == STRING_CST)
18177 /* Preserve arithmetic constants, as an optimization -- there is no
18178 reason to create a new node. */
18179 if (TREE_CODE (expr) == INTEGER_CST || TREE_CODE (expr) == REAL_CST)
18181 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
18182 There is at least one place where we want to know that a
18183 particular expression is a throw-expression: when checking a ?:
18184 expression, there are special rules if the second or third
18185 argument is a throw-expression. */
18186 if (TREE_CODE (expr) == THROW_EXPR)
18189 if (TREE_CODE (expr) == COND_EXPR)
18190 return build3 (COND_EXPR,
18192 TREE_OPERAND (expr, 0),
18193 (TREE_OPERAND (expr, 1)
18194 ? build_non_dependent_expr (TREE_OPERAND (expr, 1))
18195 : build_non_dependent_expr (TREE_OPERAND (expr, 0))),
18196 build_non_dependent_expr (TREE_OPERAND (expr, 2)));
18197 if (TREE_CODE (expr) == COMPOUND_EXPR
18198 && !COMPOUND_EXPR_OVERLOADED (expr))
18199 return build2 (COMPOUND_EXPR,
18201 TREE_OPERAND (expr, 0),
18202 build_non_dependent_expr (TREE_OPERAND (expr, 1)));
18204 /* If the type is unknown, it can't really be non-dependent */
18205 gcc_assert (TREE_TYPE (expr) != unknown_type_node);
18207 /* Otherwise, build a NON_DEPENDENT_EXPR.
18209 REFERENCE_TYPEs are not stripped for expressions in templates
18210 because doing so would play havoc with mangling. Consider, for
18213 template <typename T> void f<T& g>() { g(); }
18215 In the body of "f", the expression for "g" will have
18216 REFERENCE_TYPE, even though the standard says that it should
18217 not. The reason is that we must preserve the syntactic form of
18218 the expression so that mangling (say) "f<g>" inside the body of
18219 "f" works out correctly. Therefore, the REFERENCE_TYPE is
18221 return build1 (NON_DEPENDENT_EXPR, non_reference (TREE_TYPE (expr)), expr);
18224 /* ARGS is a vector of expressions as arguments to a function call.
18225 Replace the arguments with equivalent non-dependent expressions.
18226 This modifies ARGS in place. */
18229 make_args_non_dependent (VEC(tree,gc) *args)
18234 for (ix = 0; VEC_iterate (tree, args, ix, arg); ++ix)
18236 tree newarg = build_non_dependent_expr (arg);
18238 VEC_replace (tree, args, ix, newarg);
18242 /* Returns a type which represents 'auto'. We use a TEMPLATE_TYPE_PARM
18243 with a level one deeper than the actual template parms. */
18248 tree au = cxx_make_type (TEMPLATE_TYPE_PARM);
18249 TYPE_NAME (au) = build_decl (BUILTINS_LOCATION,
18250 TYPE_DECL, get_identifier ("auto"), au);
18251 TYPE_STUB_DECL (au) = TYPE_NAME (au);
18252 TEMPLATE_TYPE_PARM_INDEX (au) = build_template_parm_index
18253 (0, processing_template_decl + 1, processing_template_decl + 1,
18254 TYPE_NAME (au), NULL_TREE);
18255 TYPE_CANONICAL (au) = canonical_type_parameter (au);
18256 DECL_ARTIFICIAL (TYPE_NAME (au)) = 1;
18257 SET_DECL_TEMPLATE_PARM_P (TYPE_NAME (au));
18262 /* Given type ARG, return std::initializer_list<ARG>. */
18267 tree std_init_list = namespace_binding
18268 (get_identifier ("initializer_list"), std_node);
18270 if (!std_init_list || !DECL_CLASS_TEMPLATE_P (std_init_list))
18272 error ("deducing from brace-enclosed initializer list requires "
18273 "#include <initializer_list>");
18274 return error_mark_node;
18276 argvec = make_tree_vec (1);
18277 TREE_VEC_ELT (argvec, 0) = arg;
18278 return lookup_template_class (std_init_list, argvec, NULL_TREE,
18279 NULL_TREE, 0, tf_warning_or_error);
18282 /* Replace auto in TYPE with std::initializer_list<auto>. */
18285 listify_autos (tree type, tree auto_node)
18287 tree init_auto = listify (auto_node);
18288 tree argvec = make_tree_vec (1);
18289 TREE_VEC_ELT (argvec, 0) = init_auto;
18290 if (processing_template_decl)
18291 argvec = add_to_template_args (current_template_args (), argvec);
18292 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
18295 /* walk_tree helper for do_auto_deduction. */
18298 contains_auto_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
18301 /* Is this a variable with the type we're looking for? */
18303 && TREE_TYPE (*tp) == type)
18309 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
18310 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
18313 do_auto_deduction (tree type, tree init, tree auto_node)
18315 tree parms, tparms, targs;
18320 /* The name of the object being declared shall not appear in the
18321 initializer expression. */
18322 decl = cp_walk_tree_without_duplicates (&init, contains_auto_r, type);
18325 error ("variable %q#D with %<auto%> type used in its own "
18326 "initializer", decl);
18327 return error_mark_node;
18330 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
18331 with either a new invented type template parameter U or, if the
18332 initializer is a braced-init-list (8.5.4), with
18333 std::initializer_list<U>. */
18334 if (BRACE_ENCLOSED_INITIALIZER_P (init))
18335 type = listify_autos (type, auto_node);
18337 parms = build_tree_list (NULL_TREE, type);
18339 tparms = make_tree_vec (1);
18340 targs = make_tree_vec (1);
18341 TREE_VEC_ELT (tparms, 0)
18342 = build_tree_list (NULL_TREE, TYPE_NAME (auto_node));
18343 val = type_unification_real (tparms, targs, parms, args, 1, 0,
18344 DEDUCE_CALL, LOOKUP_NORMAL);
18347 error ("unable to deduce %qT from %qE", type, init);
18348 return error_mark_node;
18351 /* If the list of declarators contains more than one declarator, the type
18352 of each declared variable is determined as described above. If the
18353 type deduced for the template parameter U is not the same in each
18354 deduction, the program is ill-formed. */
18355 if (TREE_TYPE (auto_node)
18356 && !same_type_p (TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0)))
18358 error ("inconsistent deduction for %qT: %qT and then %qT",
18359 auto_node, TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0));
18360 return error_mark_node;
18362 TREE_TYPE (auto_node) = TREE_VEC_ELT (targs, 0);
18364 if (processing_template_decl)
18365 targs = add_to_template_args (current_template_args (), targs);
18366 return tsubst (type, targs, tf_warning_or_error, NULL_TREE);
18369 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
18373 splice_late_return_type (tree type, tree late_return_type)
18377 if (late_return_type == NULL_TREE)
18379 argvec = make_tree_vec (1);
18380 TREE_VEC_ELT (argvec, 0) = late_return_type;
18381 if (processing_template_decl)
18382 argvec = add_to_template_args (current_template_args (), argvec);
18383 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
18386 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto'. */
18389 is_auto (const_tree type)
18391 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
18392 && TYPE_IDENTIFIER (type) == get_identifier ("auto"))
18398 /* Returns true iff TYPE contains a use of 'auto'. Since auto can only
18399 appear as a type-specifier for the declaration in question, we don't
18400 have to look through the whole type. */
18403 type_uses_auto (tree type)
18405 enum tree_code code;
18406 if (is_auto (type))
18409 code = TREE_CODE (type);
18411 if (code == POINTER_TYPE || code == REFERENCE_TYPE
18412 || code == OFFSET_TYPE || code == FUNCTION_TYPE
18413 || code == METHOD_TYPE || code == ARRAY_TYPE)
18414 return type_uses_auto (TREE_TYPE (type));
18416 if (TYPE_PTRMEMFUNC_P (type))
18417 return type_uses_auto (TREE_TYPE (TREE_TYPE
18418 (TYPE_PTRMEMFUNC_FN_TYPE (type))));
18423 /* For a given template T, return the vector of typedefs referenced
18424 in T for which access check is needed at T instantiation time.
18425 T is either a FUNCTION_DECL or a RECORD_TYPE.
18426 Those typedefs were added to T by the function
18427 append_type_to_template_for_access_check. */
18429 VEC(qualified_typedef_usage_t,gc)*
18430 get_types_needing_access_check (tree t)
18433 VEC(qualified_typedef_usage_t,gc) *result = NULL;
18435 if (!t || t == error_mark_node)
18438 if (!(ti = get_template_info (t)))
18441 if (CLASS_TYPE_P (t)
18442 || TREE_CODE (t) == FUNCTION_DECL)
18444 if (!TI_TEMPLATE (ti))
18447 result = TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti);
18453 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
18454 tied to T. That list of typedefs will be access checked at
18455 T instantiation time.
18456 T is either a FUNCTION_DECL or a RECORD_TYPE.
18457 TYPE_DECL is a TYPE_DECL node representing a typedef.
18458 SCOPE is the scope through which TYPE_DECL is accessed.
18459 LOCATION is the location of the usage point of TYPE_DECL.
18461 This function is a subroutine of
18462 append_type_to_template_for_access_check. */
18465 append_type_to_template_for_access_check_1 (tree t,
18468 location_t location)
18470 qualified_typedef_usage_t typedef_usage;
18473 if (!t || t == error_mark_node)
18476 gcc_assert ((TREE_CODE (t) == FUNCTION_DECL
18477 || CLASS_TYPE_P (t))
18479 && TREE_CODE (type_decl) == TYPE_DECL
18482 if (!(ti = get_template_info (t)))
18485 gcc_assert (TI_TEMPLATE (ti));
18487 typedef_usage.typedef_decl = type_decl;
18488 typedef_usage.context = scope;
18489 typedef_usage.locus = location;
18491 VEC_safe_push (qualified_typedef_usage_t, gc,
18492 TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti),
18496 /* Append TYPE_DECL to the template TEMPL.
18497 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
18498 At TEMPL instanciation time, TYPE_DECL will be checked to see
18499 if it can be accessed through SCOPE.
18500 LOCATION is the location of the usage point of TYPE_DECL.
18502 e.g. consider the following code snippet:
18509 template<class U> struct S
18511 C::myint mi; // <-- usage point of the typedef C::myint
18516 At S<char> instantiation time, we need to check the access of C::myint
18517 In other words, we need to check the access of the myint typedef through
18518 the C scope. For that purpose, this function will add the myint typedef
18519 and the scope C through which its being accessed to a list of typedefs
18520 tied to the template S. That list will be walked at template instantiation
18521 time and access check performed on each typedefs it contains.
18522 Note that this particular code snippet should yield an error because
18523 myint is private to C. */
18526 append_type_to_template_for_access_check (tree templ,
18529 location_t location)
18531 qualified_typedef_usage_t *iter;
18534 gcc_assert (type_decl && (TREE_CODE (type_decl) == TYPE_DECL));
18536 /* Make sure we don't append the type to the template twice. */
18538 VEC_iterate (qualified_typedef_usage_t,
18539 get_types_needing_access_check (templ),
18542 if (iter->typedef_decl == type_decl && scope == iter->context)
18545 append_type_to_template_for_access_check_1 (templ, type_decl,
18549 /* Set up the hash tables for template instantiations. */
18552 init_template_processing (void)
18554 decl_specializations = htab_create_ggc (37,
18555 hash_specialization,
18556 eq_specializations,
18558 type_specializations = htab_create_ggc (37,
18559 hash_specialization,
18560 eq_specializations,
18564 /* Print stats about the template hash tables for -fstats. */
18567 print_template_statistics (void)
18569 fprintf (stderr, "decl_specializations: size %ld, %ld elements, "
18570 "%f collisions\n", (long) htab_size (decl_specializations),
18571 (long) htab_elements (decl_specializations),
18572 htab_collisions (decl_specializations));
18573 fprintf (stderr, "type_specializations: size %ld, %ld elements, "
18574 "%f collisions\n", (long) htab_size (type_specializations),
18575 (long) htab_elements (type_specializations),
18576 htab_collisions (type_specializations));
18579 #include "gt-cp-pt.h"