1 /* Handle parameterized types (templates) for GNU C++.
2 Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
3 2001, 2002, 2003, 2004, 2005, 2007, 2008, 2009, 2010
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);
1567 /* A lambda can't appear in a template arg, but don't crash on
1569 gcc_assert (errorcount > 0);
1576 if (TYPE_CANONICAL (arg))
1577 return iterative_hash_object (TYPE_HASH (TYPE_CANONICAL (arg)),
1579 else if (TREE_CODE (arg) == DECLTYPE_TYPE)
1580 return iterative_hash_template_arg (DECLTYPE_TYPE_EXPR (arg), val);
1581 /* Otherwise just compare the types during lookup. */
1584 case tcc_declaration:
1586 return iterative_hash_expr (arg, val);
1589 gcc_assert (IS_EXPR_CODE_CLASS (tclass));
1591 unsigned n = TREE_OPERAND_LENGTH (arg);
1592 for (i = 0; i < n; ++i)
1593 val = iterative_hash_template_arg (TREE_OPERAND (arg, i), val);
1602 /* Unregister the specialization SPEC as a specialization of TMPL.
1603 Replace it with NEW_SPEC, if NEW_SPEC is non-NULL. Returns true
1604 if the SPEC was listed as a specialization of TMPL.
1606 Note that SPEC has been ggc_freed, so we can't look inside it. */
1609 reregister_specialization (tree spec, tree tinfo, tree new_spec)
1614 elt.tmpl = most_general_template (TI_TEMPLATE (tinfo));
1615 elt.args = TI_ARGS (tinfo);
1616 elt.spec = NULL_TREE;
1618 slot = (spec_entry **) htab_find_slot (decl_specializations, &elt, INSERT);
1621 gcc_assert ((*slot)->spec == spec || (*slot)->spec == new_spec);
1622 gcc_assert (new_spec != NULL_TREE);
1623 (*slot)->spec = new_spec;
1630 /* Compare an entry in the local specializations hash table P1 (which
1631 is really a pointer to a TREE_LIST) with P2 (which is really a
1635 eq_local_specializations (const void *p1, const void *p2)
1637 return TREE_VALUE ((const_tree) p1) == (const_tree) p2;
1640 /* Hash P1, an entry in the local specializations table. */
1643 hash_local_specialization (const void* p1)
1645 return htab_hash_pointer (TREE_VALUE ((const_tree) p1));
1648 /* Like register_specialization, but for local declarations. We are
1649 registering SPEC, an instantiation of TMPL. */
1652 register_local_specialization (tree spec, tree tmpl)
1656 slot = htab_find_slot_with_hash (local_specializations, tmpl,
1657 htab_hash_pointer (tmpl), INSERT);
1658 *slot = build_tree_list (spec, tmpl);
1661 /* TYPE is a class type. Returns true if TYPE is an explicitly
1662 specialized class. */
1665 explicit_class_specialization_p (tree type)
1667 if (!CLASSTYPE_TEMPLATE_SPECIALIZATION (type))
1669 return !uses_template_parms (CLASSTYPE_TI_ARGS (type));
1672 /* Print the list of functions at FNS, going through all the overloads
1673 for each element of the list. Alternatively, FNS can not be a
1674 TREE_LIST, in which case it will be printed together with all the
1677 MORE and *STR should respectively be FALSE and NULL when the function
1678 is called from the outside. They are used internally on recursive
1679 calls. print_candidates manages the two parameters and leaves NULL
1680 in *STR when it ends. */
1683 print_candidates_1 (tree fns, bool more, const char **str)
1686 char *spaces = NULL;
1688 for (fn = fns; fn; fn = OVL_NEXT (fn))
1689 if (TREE_CODE (fn) == TREE_LIST)
1691 gcc_assert (!OVL_NEXT (fn) && !is_overloaded_fn (fn));
1692 for (fn2 = fn; fn2 != NULL_TREE; fn2 = TREE_CHAIN (fn2))
1693 print_candidates_1 (TREE_VALUE (fn2),
1694 TREE_CHAIN (fn2) || more, str);
1700 /* Pick the prefix string. */
1701 if (!more && !OVL_NEXT (fns))
1703 error ("candidate is: %+#D", OVL_CURRENT (fn));
1707 *str = _("candidates are:");
1708 spaces = get_spaces (*str);
1710 error ("%s %+#D", *str, OVL_CURRENT (fn));
1711 *str = spaces ? spaces : *str;
1721 /* Print the list of candidate FNS in an error message. */
1724 print_candidates (tree fns)
1726 const char *str = NULL;
1727 print_candidates_1 (fns, false, &str);
1728 gcc_assert (str == NULL);
1731 /* Returns the template (one of the functions given by TEMPLATE_ID)
1732 which can be specialized to match the indicated DECL with the
1733 explicit template args given in TEMPLATE_ID. The DECL may be
1734 NULL_TREE if none is available. In that case, the functions in
1735 TEMPLATE_ID are non-members.
1737 If NEED_MEMBER_TEMPLATE is nonzero the function is known to be a
1738 specialization of a member template.
1740 The TEMPLATE_COUNT is the number of references to qualifying
1741 template classes that appeared in the name of the function. See
1742 check_explicit_specialization for a more accurate description.
1744 TSK indicates what kind of template declaration (if any) is being
1745 declared. TSK_TEMPLATE indicates that the declaration given by
1746 DECL, though a FUNCTION_DECL, has template parameters, and is
1747 therefore a template function.
1749 The template args (those explicitly specified and those deduced)
1750 are output in a newly created vector *TARGS_OUT.
1752 If it is impossible to determine the result, an error message is
1753 issued. The error_mark_node is returned to indicate failure. */
1756 determine_specialization (tree template_id,
1759 int need_member_template,
1765 tree explicit_targs;
1766 tree candidates = NULL_TREE;
1767 /* A TREE_LIST of templates of which DECL may be a specialization.
1768 The TREE_VALUE of each node is a TEMPLATE_DECL. The
1769 corresponding TREE_PURPOSE is the set of template arguments that,
1770 when used to instantiate the template, would produce a function
1771 with the signature of DECL. */
1772 tree templates = NULL_TREE;
1774 struct cp_binding_level *b;
1776 *targs_out = NULL_TREE;
1778 if (template_id == error_mark_node || decl == error_mark_node)
1779 return error_mark_node;
1781 fns = TREE_OPERAND (template_id, 0);
1782 explicit_targs = TREE_OPERAND (template_id, 1);
1784 if (fns == error_mark_node)
1785 return error_mark_node;
1787 /* Check for baselinks. */
1788 if (BASELINK_P (fns))
1789 fns = BASELINK_FUNCTIONS (fns);
1791 if (!is_overloaded_fn (fns))
1793 error ("%qD is not a function template", fns);
1794 return error_mark_node;
1797 /* Count the number of template headers specified for this
1800 for (b = current_binding_level;
1801 b->kind == sk_template_parms;
1805 for (; fns; fns = OVL_NEXT (fns))
1807 tree fn = OVL_CURRENT (fns);
1809 if (TREE_CODE (fn) == TEMPLATE_DECL)
1811 tree decl_arg_types;
1814 /* In case of explicit specialization, we need to check if
1815 the number of template headers appearing in the specialization
1816 is correct. This is usually done in check_explicit_specialization,
1817 but the check done there cannot be exhaustive when specializing
1818 member functions. Consider the following code:
1820 template <> void A<int>::f(int);
1821 template <> template <> void A<int>::f(int);
1823 Assuming that A<int> is not itself an explicit specialization
1824 already, the first line specializes "f" which is a non-template
1825 member function, whilst the second line specializes "f" which
1826 is a template member function. So both lines are syntactically
1827 correct, and check_explicit_specialization does not reject
1830 Here, we can do better, as we are matching the specialization
1831 against the declarations. We count the number of template
1832 headers, and we check if they match TEMPLATE_COUNT + 1
1833 (TEMPLATE_COUNT is the number of qualifying template classes,
1834 plus there must be another header for the member template
1837 Notice that if header_count is zero, this is not a
1838 specialization but rather a template instantiation, so there
1839 is no check we can perform here. */
1840 if (header_count && header_count != template_count + 1)
1843 /* Check that the number of template arguments at the
1844 innermost level for DECL is the same as for FN. */
1845 if (current_binding_level->kind == sk_template_parms
1846 && !current_binding_level->explicit_spec_p
1847 && (TREE_VEC_LENGTH (DECL_INNERMOST_TEMPLATE_PARMS (fn))
1848 != TREE_VEC_LENGTH (INNERMOST_TEMPLATE_PARMS
1849 (current_template_parms))))
1852 /* DECL might be a specialization of FN. */
1853 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1854 fn_arg_types = TYPE_ARG_TYPES (TREE_TYPE (fn));
1856 /* For a non-static member function, we need to make sure
1857 that the const qualification is the same. Since
1858 get_bindings does not try to merge the "this" parameter,
1859 we must do the comparison explicitly. */
1860 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn)
1861 && !same_type_p (TREE_VALUE (fn_arg_types),
1862 TREE_VALUE (decl_arg_types)))
1865 /* Skip the "this" parameter and, for constructors of
1866 classes with virtual bases, the VTT parameter. A
1867 full specialization of a constructor will have a VTT
1868 parameter, but a template never will. */
1870 = skip_artificial_parms_for (decl, decl_arg_types);
1872 = skip_artificial_parms_for (fn, fn_arg_types);
1874 /* Check that the number of function parameters matches.
1876 template <class T> void f(int i = 0);
1877 template <> void f<int>();
1878 The specialization f<int> is invalid but is not caught
1879 by get_bindings below. */
1880 if (list_length (fn_arg_types) != list_length (decl_arg_types))
1883 /* Function templates cannot be specializations; there are
1884 no partial specializations of functions. Therefore, if
1885 the type of DECL does not match FN, there is no
1887 if (tsk == tsk_template)
1889 if (compparms (fn_arg_types, decl_arg_types))
1890 candidates = tree_cons (NULL_TREE, fn, candidates);
1894 /* See whether this function might be a specialization of this
1896 targs = get_bindings (fn, decl, explicit_targs, /*check_ret=*/true);
1899 /* We cannot deduce template arguments that when used to
1900 specialize TMPL will produce DECL. */
1903 /* Save this template, and the arguments deduced. */
1904 templates = tree_cons (targs, fn, templates);
1906 else if (need_member_template)
1907 /* FN is an ordinary member function, and we need a
1908 specialization of a member template. */
1910 else if (TREE_CODE (fn) != FUNCTION_DECL)
1911 /* We can get IDENTIFIER_NODEs here in certain erroneous
1914 else if (!DECL_FUNCTION_MEMBER_P (fn))
1915 /* This is just an ordinary non-member function. Nothing can
1916 be a specialization of that. */
1918 else if (DECL_ARTIFICIAL (fn))
1919 /* Cannot specialize functions that are created implicitly. */
1923 tree decl_arg_types;
1925 /* This is an ordinary member function. However, since
1926 we're here, we can assume it's enclosing class is a
1927 template class. For example,
1929 template <typename T> struct S { void f(); };
1930 template <> void S<int>::f() {}
1932 Here, S<int>::f is a non-template, but S<int> is a
1933 template class. If FN has the same type as DECL, we
1934 might be in business. */
1936 if (!DECL_TEMPLATE_INFO (fn))
1937 /* Its enclosing class is an explicit specialization
1938 of a template class. This is not a candidate. */
1941 if (!same_type_p (TREE_TYPE (TREE_TYPE (decl)),
1942 TREE_TYPE (TREE_TYPE (fn))))
1943 /* The return types differ. */
1946 /* Adjust the type of DECL in case FN is a static member. */
1947 decl_arg_types = TYPE_ARG_TYPES (TREE_TYPE (decl));
1948 if (DECL_STATIC_FUNCTION_P (fn)
1949 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
1950 decl_arg_types = TREE_CHAIN (decl_arg_types);
1952 if (compparms (TYPE_ARG_TYPES (TREE_TYPE (fn)),
1955 candidates = tree_cons (NULL_TREE, fn, candidates);
1959 if (templates && TREE_CHAIN (templates))
1965 It is possible for a specialization with a given function
1966 signature to be instantiated from more than one function
1967 template. In such cases, explicit specification of the
1968 template arguments must be used to uniquely identify the
1969 function template specialization being specialized.
1971 Note that here, there's no suggestion that we're supposed to
1972 determine which of the candidate templates is most
1973 specialized. However, we, also have:
1977 Partial ordering of overloaded function template
1978 declarations is used in the following contexts to select
1979 the function template to which a function template
1980 specialization refers:
1982 -- when an explicit specialization refers to a function
1985 So, we do use the partial ordering rules, at least for now.
1986 This extension can only serve to make invalid programs valid,
1987 so it's safe. And, there is strong anecdotal evidence that
1988 the committee intended the partial ordering rules to apply;
1989 the EDG front end has that behavior, and John Spicer claims
1990 that the committee simply forgot to delete the wording in
1991 [temp.expl.spec]. */
1992 tree tmpl = most_specialized_instantiation (templates);
1993 if (tmpl != error_mark_node)
1996 TREE_CHAIN (templates) = NULL_TREE;
2000 if (templates == NULL_TREE && candidates == NULL_TREE)
2002 error ("template-id %qD for %q+D does not match any template "
2003 "declaration", template_id, decl);
2004 if (header_count && header_count != template_count + 1)
2005 inform (input_location, "saw %d %<template<>%>, need %d for "
2006 "specializing a member function template",
2007 header_count, template_count + 1);
2008 return error_mark_node;
2010 else if ((templates && TREE_CHAIN (templates))
2011 || (candidates && TREE_CHAIN (candidates))
2012 || (templates && candidates))
2014 error ("ambiguous template specialization %qD for %q+D",
2016 candidates = chainon (candidates, templates);
2017 print_candidates (candidates);
2018 return error_mark_node;
2021 /* We have one, and exactly one, match. */
2024 tree fn = TREE_VALUE (candidates);
2025 *targs_out = copy_node (DECL_TI_ARGS (fn));
2026 /* DECL is a re-declaration or partial instantiation of a template
2028 if (TREE_CODE (fn) == TEMPLATE_DECL)
2030 /* It was a specialization of an ordinary member function in a
2032 return DECL_TI_TEMPLATE (fn);
2035 /* It was a specialization of a template. */
2036 targs = DECL_TI_ARGS (DECL_TEMPLATE_RESULT (TREE_VALUE (templates)));
2037 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (targs))
2039 *targs_out = copy_node (targs);
2040 SET_TMPL_ARGS_LEVEL (*targs_out,
2041 TMPL_ARGS_DEPTH (*targs_out),
2042 TREE_PURPOSE (templates));
2045 *targs_out = TREE_PURPOSE (templates);
2046 return TREE_VALUE (templates);
2049 /* Returns a chain of parameter types, exactly like the SPEC_TYPES,
2050 but with the default argument values filled in from those in the
2054 copy_default_args_to_explicit_spec_1 (tree spec_types,
2057 tree new_spec_types;
2062 if (spec_types == void_list_node)
2063 return void_list_node;
2065 /* Substitute into the rest of the list. */
2067 copy_default_args_to_explicit_spec_1 (TREE_CHAIN (spec_types),
2068 TREE_CHAIN (tmpl_types));
2070 /* Add the default argument for this parameter. */
2071 return hash_tree_cons (TREE_PURPOSE (tmpl_types),
2072 TREE_VALUE (spec_types),
2076 /* DECL is an explicit specialization. Replicate default arguments
2077 from the template it specializes. (That way, code like:
2079 template <class T> void f(T = 3);
2080 template <> void f(double);
2083 works, as required.) An alternative approach would be to look up
2084 the correct default arguments at the call-site, but this approach
2085 is consistent with how implicit instantiations are handled. */
2088 copy_default_args_to_explicit_spec (tree decl)
2093 tree new_spec_types;
2097 tree object_type = NULL_TREE;
2098 tree in_charge = NULL_TREE;
2099 tree vtt = NULL_TREE;
2101 /* See if there's anything we need to do. */
2102 tmpl = DECL_TI_TEMPLATE (decl);
2103 tmpl_types = TYPE_ARG_TYPES (TREE_TYPE (DECL_TEMPLATE_RESULT (tmpl)));
2104 for (t = tmpl_types; t; t = TREE_CHAIN (t))
2105 if (TREE_PURPOSE (t))
2110 old_type = TREE_TYPE (decl);
2111 spec_types = TYPE_ARG_TYPES (old_type);
2113 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2115 /* Remove the this pointer, but remember the object's type for
2117 object_type = TREE_TYPE (TREE_VALUE (spec_types));
2118 spec_types = TREE_CHAIN (spec_types);
2119 tmpl_types = TREE_CHAIN (tmpl_types);
2121 if (DECL_HAS_IN_CHARGE_PARM_P (decl))
2123 /* DECL may contain more parameters than TMPL due to the extra
2124 in-charge parameter in constructors and destructors. */
2125 in_charge = spec_types;
2126 spec_types = TREE_CHAIN (spec_types);
2128 if (DECL_HAS_VTT_PARM_P (decl))
2131 spec_types = TREE_CHAIN (spec_types);
2135 /* Compute the merged default arguments. */
2137 copy_default_args_to_explicit_spec_1 (spec_types, tmpl_types);
2139 /* Compute the new FUNCTION_TYPE. */
2143 new_spec_types = hash_tree_cons (TREE_PURPOSE (vtt),
2148 /* Put the in-charge parameter back. */
2149 new_spec_types = hash_tree_cons (TREE_PURPOSE (in_charge),
2150 TREE_VALUE (in_charge),
2153 new_type = build_method_type_directly (object_type,
2154 TREE_TYPE (old_type),
2158 new_type = build_function_type (TREE_TYPE (old_type),
2160 new_type = cp_build_type_attribute_variant (new_type,
2161 TYPE_ATTRIBUTES (old_type));
2162 new_type = build_exception_variant (new_type,
2163 TYPE_RAISES_EXCEPTIONS (old_type));
2164 TREE_TYPE (decl) = new_type;
2167 /* Check to see if the function just declared, as indicated in
2168 DECLARATOR, and in DECL, is a specialization of a function
2169 template. We may also discover that the declaration is an explicit
2170 instantiation at this point.
2172 Returns DECL, or an equivalent declaration that should be used
2173 instead if all goes well. Issues an error message if something is
2174 amiss. Returns error_mark_node if the error is not easily
2177 FLAGS is a bitmask consisting of the following flags:
2179 2: The function has a definition.
2180 4: The function is a friend.
2182 The TEMPLATE_COUNT is the number of references to qualifying
2183 template classes that appeared in the name of the function. For
2186 template <class T> struct S { void f(); };
2189 the TEMPLATE_COUNT would be 1. However, explicitly specialized
2190 classes are not counted in the TEMPLATE_COUNT, so that in
2192 template <class T> struct S {};
2193 template <> struct S<int> { void f(); }
2194 template <> void S<int>::f();
2196 the TEMPLATE_COUNT would be 0. (Note that this declaration is
2197 invalid; there should be no template <>.)
2199 If the function is a specialization, it is marked as such via
2200 DECL_TEMPLATE_SPECIALIZATION. Furthermore, its DECL_TEMPLATE_INFO
2201 is set up correctly, and it is added to the list of specializations
2202 for that template. */
2205 check_explicit_specialization (tree declarator,
2210 int have_def = flags & 2;
2211 int is_friend = flags & 4;
2212 int specialization = 0;
2213 int explicit_instantiation = 0;
2214 int member_specialization = 0;
2215 tree ctype = DECL_CLASS_CONTEXT (decl);
2216 tree dname = DECL_NAME (decl);
2221 if (!processing_specialization)
2224 tsk = tsk_excessive_parms;
2227 tsk = current_tmpl_spec_kind (template_count);
2232 if (processing_specialization)
2235 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2237 else if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2240 /* This could be something like:
2242 template <class T> void f(T);
2243 class S { friend void f<>(int); } */
2247 /* This case handles bogus declarations like template <>
2248 template <class T> void f<int>(); */
2250 error ("template-id %qD in declaration of primary template",
2257 case tsk_invalid_member_spec:
2258 /* The error has already been reported in
2259 check_specialization_scope. */
2260 return error_mark_node;
2262 case tsk_invalid_expl_inst:
2263 error ("template parameter list used in explicit instantiation");
2269 error ("definition provided for explicit instantiation");
2271 explicit_instantiation = 1;
2274 case tsk_excessive_parms:
2275 case tsk_insufficient_parms:
2276 if (tsk == tsk_excessive_parms)
2277 error ("too many template parameter lists in declaration of %qD",
2279 else if (template_header_count)
2280 error("too few template parameter lists in declaration of %qD", decl);
2282 error("explicit specialization of %qD must be introduced by "
2283 "%<template <>%>", decl);
2287 SET_DECL_TEMPLATE_SPECIALIZATION (decl);
2289 member_specialization = 1;
2295 if (TREE_CODE (declarator) == TEMPLATE_ID_EXPR)
2297 /* This case handles bogus declarations like template <>
2298 template <class T> void f<int>(); */
2300 if (uses_template_parms (declarator))
2301 error ("function template partial specialization %qD "
2302 "is not allowed", declarator);
2304 error ("template-id %qD in declaration of primary template",
2309 if (ctype && CLASSTYPE_TEMPLATE_INSTANTIATION (ctype))
2310 /* This is a specialization of a member template, without
2311 specialization the containing class. Something like:
2313 template <class T> struct S {
2314 template <class U> void f (U);
2316 template <> template <class U> void S<int>::f(U) {}
2318 That's a specialization -- but of the entire template. */
2326 if (specialization || member_specialization)
2328 tree t = TYPE_ARG_TYPES (TREE_TYPE (decl));
2329 for (; t; t = TREE_CHAIN (t))
2330 if (TREE_PURPOSE (t))
2332 permerror (input_location,
2333 "default argument specified in explicit specialization");
2338 if (specialization || member_specialization || explicit_instantiation)
2340 tree tmpl = NULL_TREE;
2341 tree targs = NULL_TREE;
2343 /* Make sure that the declarator is a TEMPLATE_ID_EXPR. */
2344 if (TREE_CODE (declarator) != TEMPLATE_ID_EXPR)
2348 gcc_assert (TREE_CODE (declarator) == IDENTIFIER_NODE);
2353 /* If there is no class context, the explicit instantiation
2354 must be at namespace scope. */
2355 gcc_assert (DECL_NAMESPACE_SCOPE_P (decl));
2357 /* Find the namespace binding, using the declaration
2359 fns = lookup_qualified_name (CP_DECL_CONTEXT (decl), dname,
2361 if (fns == error_mark_node || !is_overloaded_fn (fns))
2363 error ("%qD is not a template function", dname);
2364 fns = error_mark_node;
2368 tree fn = OVL_CURRENT (fns);
2369 if (!is_associated_namespace (CP_DECL_CONTEXT (decl),
2370 CP_DECL_CONTEXT (fn)))
2371 error ("%qD is not declared in %qD",
2372 decl, current_namespace);
2376 declarator = lookup_template_function (fns, NULL_TREE);
2379 if (declarator == error_mark_node)
2380 return error_mark_node;
2382 if (ctype != NULL_TREE && TYPE_BEING_DEFINED (ctype))
2384 if (!explicit_instantiation)
2385 /* A specialization in class scope. This is invalid,
2386 but the error will already have been flagged by
2387 check_specialization_scope. */
2388 return error_mark_node;
2391 /* It's not valid to write an explicit instantiation in
2394 class C { template void f(); }
2396 This case is caught by the parser. However, on
2399 template class C { void f(); };
2401 (which is invalid) we can get here. The error will be
2408 else if (ctype != NULL_TREE
2409 && (TREE_CODE (TREE_OPERAND (declarator, 0)) ==
2412 /* Find the list of functions in ctype that have the same
2413 name as the declared function. */
2414 tree name = TREE_OPERAND (declarator, 0);
2415 tree fns = NULL_TREE;
2418 if (constructor_name_p (name, ctype))
2420 int is_constructor = DECL_CONSTRUCTOR_P (decl);
2422 if (is_constructor ? !TYPE_HAS_USER_CONSTRUCTOR (ctype)
2423 : !CLASSTYPE_DESTRUCTORS (ctype))
2425 /* From [temp.expl.spec]:
2427 If such an explicit specialization for the member
2428 of a class template names an implicitly-declared
2429 special member function (clause _special_), the
2430 program is ill-formed.
2432 Similar language is found in [temp.explicit]. */
2433 error ("specialization of implicitly-declared special member function");
2434 return error_mark_node;
2437 name = is_constructor ? ctor_identifier : dtor_identifier;
2440 if (!DECL_CONV_FN_P (decl))
2442 idx = lookup_fnfields_1 (ctype, name);
2444 fns = VEC_index (tree, CLASSTYPE_METHOD_VEC (ctype), idx);
2448 VEC(tree,gc) *methods;
2451 /* For a type-conversion operator, we cannot do a
2452 name-based lookup. We might be looking for `operator
2453 int' which will be a specialization of `operator T'.
2454 So, we find *all* the conversion operators, and then
2455 select from them. */
2458 methods = CLASSTYPE_METHOD_VEC (ctype);
2460 for (idx = CLASSTYPE_FIRST_CONVERSION_SLOT;
2461 VEC_iterate (tree, methods, idx, ovl);
2464 if (!DECL_CONV_FN_P (OVL_CURRENT (ovl)))
2465 /* There are no more conversion functions. */
2468 /* Glue all these conversion functions together
2469 with those we already have. */
2470 for (; ovl; ovl = OVL_NEXT (ovl))
2471 fns = ovl_cons (OVL_CURRENT (ovl), fns);
2475 if (fns == NULL_TREE)
2477 error ("no member function %qD declared in %qT", name, ctype);
2478 return error_mark_node;
2481 TREE_OPERAND (declarator, 0) = fns;
2484 /* Figure out what exactly is being specialized at this point.
2485 Note that for an explicit instantiation, even one for a
2486 member function, we cannot tell apriori whether the
2487 instantiation is for a member template, or just a member
2488 function of a template class. Even if a member template is
2489 being instantiated, the member template arguments may be
2490 elided if they can be deduced from the rest of the
2492 tmpl = determine_specialization (declarator, decl,
2494 member_specialization,
2498 if (!tmpl || tmpl == error_mark_node)
2499 /* We couldn't figure out what this declaration was
2501 return error_mark_node;
2504 tree gen_tmpl = most_general_template (tmpl);
2506 if (explicit_instantiation)
2508 /* We don't set DECL_EXPLICIT_INSTANTIATION here; that
2509 is done by do_decl_instantiation later. */
2511 int arg_depth = TMPL_ARGS_DEPTH (targs);
2512 int parm_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
2514 if (arg_depth > parm_depth)
2516 /* If TMPL is not the most general template (for
2517 example, if TMPL is a friend template that is
2518 injected into namespace scope), then there will
2519 be too many levels of TARGS. Remove some of them
2524 new_targs = make_tree_vec (parm_depth);
2525 for (i = arg_depth - parm_depth; i < arg_depth; ++i)
2526 TREE_VEC_ELT (new_targs, i - (arg_depth - parm_depth))
2527 = TREE_VEC_ELT (targs, i);
2531 return instantiate_template (tmpl, targs, tf_error);
2534 /* If we thought that the DECL was a member function, but it
2535 turns out to be specializing a static member function,
2536 make DECL a static member function as well. */
2537 if (DECL_STATIC_FUNCTION_P (tmpl)
2538 && DECL_NONSTATIC_MEMBER_FUNCTION_P (decl))
2539 revert_static_member_fn (decl);
2541 /* If this is a specialization of a member template of a
2542 template class, we want to return the TEMPLATE_DECL, not
2543 the specialization of it. */
2544 if (tsk == tsk_template)
2546 tree result = DECL_TEMPLATE_RESULT (tmpl);
2547 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
2548 DECL_INITIAL (result) = NULL_TREE;
2552 DECL_SOURCE_LOCATION (tmpl) = DECL_SOURCE_LOCATION (decl);
2553 DECL_SOURCE_LOCATION (result)
2554 = DECL_SOURCE_LOCATION (decl);
2555 /* We want to use the argument list specified in the
2556 definition, not in the original declaration. */
2557 DECL_ARGUMENTS (result) = DECL_ARGUMENTS (decl);
2558 for (parm = DECL_ARGUMENTS (result); parm;
2559 parm = TREE_CHAIN (parm))
2560 DECL_CONTEXT (parm) = result;
2562 return register_specialization (tmpl, gen_tmpl, targs,
2566 /* Set up the DECL_TEMPLATE_INFO for DECL. */
2567 DECL_TEMPLATE_INFO (decl) = build_template_info (tmpl, targs);
2569 /* Inherit default function arguments from the template
2570 DECL is specializing. */
2571 copy_default_args_to_explicit_spec (decl);
2573 /* This specialization has the same protection as the
2574 template it specializes. */
2575 TREE_PRIVATE (decl) = TREE_PRIVATE (gen_tmpl);
2576 TREE_PROTECTED (decl) = TREE_PROTECTED (gen_tmpl);
2578 /* 7.1.1-1 [dcl.stc]
2580 A storage-class-specifier shall not be specified in an
2581 explicit specialization...
2583 The parser rejects these, so unless action is taken here,
2584 explicit function specializations will always appear with
2587 The action recommended by the C++ CWG in response to C++
2588 defect report 605 is to make the storage class and linkage
2589 of the explicit specialization match the templated function:
2591 http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_active.html#605
2593 if (tsk == tsk_expl_spec && DECL_FUNCTION_TEMPLATE_P (gen_tmpl))
2595 tree tmpl_func = DECL_TEMPLATE_RESULT (gen_tmpl);
2596 gcc_assert (TREE_CODE (tmpl_func) == FUNCTION_DECL);
2598 /* This specialization has the same linkage and visibility as
2599 the function template it specializes. */
2600 TREE_PUBLIC (decl) = TREE_PUBLIC (tmpl_func);
2601 if (! TREE_PUBLIC (decl))
2603 DECL_INTERFACE_KNOWN (decl) = 1;
2604 DECL_NOT_REALLY_EXTERN (decl) = 1;
2606 DECL_THIS_STATIC (decl) = DECL_THIS_STATIC (tmpl_func);
2607 if (DECL_VISIBILITY_SPECIFIED (tmpl_func))
2609 DECL_VISIBILITY_SPECIFIED (decl) = 1;
2610 DECL_VISIBILITY (decl) = DECL_VISIBILITY (tmpl_func);
2614 /* If DECL is a friend declaration, declared using an
2615 unqualified name, the namespace associated with DECL may
2616 have been set incorrectly. For example, in:
2618 template <typename T> void f(T);
2620 struct S { friend void f<int>(int); }
2623 we will have set the DECL_CONTEXT for the friend
2624 declaration to N, rather than to the global namespace. */
2625 if (DECL_NAMESPACE_SCOPE_P (decl))
2626 DECL_CONTEXT (decl) = DECL_CONTEXT (tmpl);
2628 if (is_friend && !have_def)
2629 /* This is not really a declaration of a specialization.
2630 It's just the name of an instantiation. But, it's not
2631 a request for an instantiation, either. */
2632 SET_DECL_IMPLICIT_INSTANTIATION (decl);
2633 else if (DECL_CONSTRUCTOR_P (decl) || DECL_DESTRUCTOR_P (decl))
2634 /* This is indeed a specialization. In case of constructors
2635 and destructors, we need in-charge and not-in-charge
2636 versions in V3 ABI. */
2637 clone_function_decl (decl, /*update_method_vec_p=*/0);
2639 /* Register this specialization so that we can find it
2641 decl = register_specialization (decl, gen_tmpl, targs, is_friend, 0);
2648 /* Returns 1 iff PARMS1 and PARMS2 are identical sets of template
2649 parameters. These are represented in the same format used for
2650 DECL_TEMPLATE_PARMS. */
2653 comp_template_parms (const_tree parms1, const_tree parms2)
2658 if (parms1 == parms2)
2661 for (p1 = parms1, p2 = parms2;
2662 p1 != NULL_TREE && p2 != NULL_TREE;
2663 p1 = TREE_CHAIN (p1), p2 = TREE_CHAIN (p2))
2665 tree t1 = TREE_VALUE (p1);
2666 tree t2 = TREE_VALUE (p2);
2669 gcc_assert (TREE_CODE (t1) == TREE_VEC);
2670 gcc_assert (TREE_CODE (t2) == TREE_VEC);
2672 if (TREE_VEC_LENGTH (t1) != TREE_VEC_LENGTH (t2))
2675 for (i = 0; i < TREE_VEC_LENGTH (t2); ++i)
2677 tree parm1 = TREE_VALUE (TREE_VEC_ELT (t1, i));
2678 tree parm2 = TREE_VALUE (TREE_VEC_ELT (t2, i));
2680 /* If either of the template parameters are invalid, assume
2681 they match for the sake of error recovery. */
2682 if (parm1 == error_mark_node || parm2 == error_mark_node)
2685 if (TREE_CODE (parm1) != TREE_CODE (parm2))
2688 if (TREE_CODE (parm1) == TEMPLATE_TYPE_PARM
2689 && (TEMPLATE_TYPE_PARAMETER_PACK (parm1)
2690 == TEMPLATE_TYPE_PARAMETER_PACK (parm2)))
2692 else if (!same_type_p (TREE_TYPE (parm1), TREE_TYPE (parm2)))
2697 if ((p1 != NULL_TREE) != (p2 != NULL_TREE))
2698 /* One set of parameters has more parameters lists than the
2705 /* Determine whether PARM is a parameter pack. */
2708 template_parameter_pack_p (const_tree parm)
2710 /* Determine if we have a non-type template parameter pack. */
2711 if (TREE_CODE (parm) == PARM_DECL)
2712 return (DECL_TEMPLATE_PARM_P (parm)
2713 && TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)));
2715 /* If this is a list of template parameters, we could get a
2716 TYPE_DECL or a TEMPLATE_DECL. */
2717 if (TREE_CODE (parm) == TYPE_DECL || TREE_CODE (parm) == TEMPLATE_DECL)
2718 parm = TREE_TYPE (parm);
2720 return ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
2721 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM)
2722 && TEMPLATE_TYPE_PARAMETER_PACK (parm));
2725 /* Determine if T is a function parameter pack. */
2728 function_parameter_pack_p (const_tree t)
2730 if (t && TREE_CODE (t) == PARM_DECL)
2731 return FUNCTION_PARAMETER_PACK_P (t);
2735 /* Return the function template declaration of PRIMARY_FUNC_TMPL_INST.
2736 PRIMARY_FUNC_TMPL_INST is a primary function template instantiation. */
2739 get_function_template_decl (const_tree primary_func_tmpl_inst)
2741 if (! primary_func_tmpl_inst
2742 || TREE_CODE (primary_func_tmpl_inst) != FUNCTION_DECL
2743 || ! primary_template_instantiation_p (primary_func_tmpl_inst))
2746 return DECL_TEMPLATE_RESULT (DECL_TI_TEMPLATE (primary_func_tmpl_inst));
2749 /* Return true iff the function parameter PARAM_DECL was expanded
2750 from the function parameter pack PACK. */
2753 function_parameter_expanded_from_pack_p (tree param_decl, tree pack)
2755 if (DECL_ARTIFICIAL (param_decl)
2756 || !function_parameter_pack_p (pack))
2759 /* The parameter pack and its pack arguments have the same
2761 return DECL_PARM_INDEX (pack) == DECL_PARM_INDEX (param_decl);
2764 /* Determine whether ARGS describes a variadic template args list,
2765 i.e., one that is terminated by a template argument pack. */
2768 template_args_variadic_p (tree args)
2773 if (args == NULL_TREE)
2776 args = INNERMOST_TEMPLATE_ARGS (args);
2777 nargs = TREE_VEC_LENGTH (args);
2782 last_parm = TREE_VEC_ELT (args, nargs - 1);
2784 return ARGUMENT_PACK_P (last_parm);
2787 /* Generate a new name for the parameter pack name NAME (an
2788 IDENTIFIER_NODE) that incorporates its */
2791 make_ith_pack_parameter_name (tree name, int i)
2793 /* Munge the name to include the parameter index. */
2794 #define NUMBUF_LEN 128
2795 char numbuf[NUMBUF_LEN];
2799 snprintf (numbuf, NUMBUF_LEN, "%i", i);
2800 newname_len = IDENTIFIER_LENGTH (name)
2801 + strlen (numbuf) + 2;
2802 newname = (char*)alloca (newname_len);
2803 snprintf (newname, newname_len,
2804 "%s#%i", IDENTIFIER_POINTER (name), i);
2805 return get_identifier (newname);
2808 /* Return true if T is a primary function
2809 or class template instantiation. */
2812 primary_template_instantiation_p (const_tree t)
2817 if (TREE_CODE (t) == FUNCTION_DECL)
2818 return DECL_LANG_SPECIFIC (t)
2819 && DECL_TEMPLATE_INSTANTIATION (t)
2820 && PRIMARY_TEMPLATE_P (DECL_TI_TEMPLATE (t));
2821 else if (CLASS_TYPE_P (t))
2822 return CLASSTYPE_TEMPLATE_INSTANTIATION (t)
2823 && PRIMARY_TEMPLATE_P (CLASSTYPE_TI_TEMPLATE (t));
2827 /* Return true if PARM is a template template parameter. */
2830 template_template_parameter_p (const_tree parm)
2832 return DECL_TEMPLATE_TEMPLATE_PARM_P (parm);
2835 /* Return the template parameters of T if T is a
2836 primary template instantiation, NULL otherwise. */
2839 get_primary_template_innermost_parameters (const_tree t)
2841 tree parms = NULL, template_info = NULL;
2843 if ((template_info = get_template_info (t))
2844 && primary_template_instantiation_p (t))
2845 parms = INNERMOST_TEMPLATE_PARMS
2846 (DECL_TEMPLATE_PARMS (TI_TEMPLATE (template_info)));
2851 /* Return the template parameters of the LEVELth level from the full list
2852 of template parameters PARMS. */
2855 get_template_parms_at_level (tree parms, int level)
2859 || TREE_CODE (parms) != TREE_LIST
2860 || level > TMPL_PARMS_DEPTH (parms))
2863 for (p = parms; p; p = TREE_CHAIN (p))
2864 if (TMPL_PARMS_DEPTH (p) == level)
2870 /* Returns the template arguments of T if T is a template instantiation,
2874 get_template_innermost_arguments (const_tree t)
2876 tree args = NULL, template_info = NULL;
2878 if ((template_info = get_template_info (t))
2879 && TI_ARGS (template_info))
2880 args = INNERMOST_TEMPLATE_ARGS (TI_ARGS (template_info));
2885 /* Return the argument pack elements of T if T is a template argument pack,
2889 get_template_argument_pack_elems (const_tree t)
2891 if (TREE_CODE (t) != TYPE_ARGUMENT_PACK
2892 && TREE_CODE (t) != NONTYPE_ARGUMENT_PACK)
2895 return ARGUMENT_PACK_ARGS (t);
2898 /* Structure used to track the progress of find_parameter_packs_r. */
2899 struct find_parameter_pack_data
2901 /* TREE_LIST that will contain all of the parameter packs found by
2903 tree* parameter_packs;
2905 /* Set of AST nodes that have been visited by the traversal. */
2906 struct pointer_set_t *visited;
2909 /* Identifies all of the argument packs that occur in a template
2910 argument and appends them to the TREE_LIST inside DATA, which is a
2911 find_parameter_pack_data structure. This is a subroutine of
2912 make_pack_expansion and uses_parameter_packs. */
2914 find_parameter_packs_r (tree *tp, int *walk_subtrees, void* data)
2917 struct find_parameter_pack_data* ppd =
2918 (struct find_parameter_pack_data*)data;
2919 bool parameter_pack_p = false;
2921 /* Identify whether this is a parameter pack or not. */
2922 switch (TREE_CODE (t))
2924 case TEMPLATE_PARM_INDEX:
2925 if (TEMPLATE_PARM_PARAMETER_PACK (t))
2926 parameter_pack_p = true;
2929 case TEMPLATE_TYPE_PARM:
2930 case TEMPLATE_TEMPLATE_PARM:
2931 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
2932 parameter_pack_p = true;
2936 if (FUNCTION_PARAMETER_PACK_P (t))
2938 /* We don't want to walk into the type of a PARM_DECL,
2939 because we don't want to see the type parameter pack. */
2941 parameter_pack_p = true;
2946 /* Not a parameter pack. */
2950 if (parameter_pack_p)
2952 /* Add this parameter pack to the list. */
2953 *ppd->parameter_packs = tree_cons (NULL_TREE, t, *ppd->parameter_packs);
2957 cp_walk_tree (&TYPE_CONTEXT (t),
2958 &find_parameter_packs_r, ppd, ppd->visited);
2960 /* This switch statement will return immediately if we don't find a
2962 switch (TREE_CODE (t))
2964 case TEMPLATE_PARM_INDEX:
2967 case BOUND_TEMPLATE_TEMPLATE_PARM:
2968 /* Check the template itself. */
2969 cp_walk_tree (&TREE_TYPE (TYPE_TI_TEMPLATE (t)),
2970 &find_parameter_packs_r, ppd, ppd->visited);
2971 /* Check the template arguments. */
2972 cp_walk_tree (&TYPE_TI_ARGS (t), &find_parameter_packs_r, ppd,
2977 case TEMPLATE_TYPE_PARM:
2978 case TEMPLATE_TEMPLATE_PARM:
2985 if (TYPE_PTRMEMFUNC_P (t))
2991 if (TYPE_TEMPLATE_INFO (t))
2992 cp_walk_tree (&TI_ARGS (TYPE_TEMPLATE_INFO (t)),
2993 &find_parameter_packs_r, ppd, ppd->visited);
2999 cp_walk_tree (&TREE_TYPE (t),
3000 &find_parameter_packs_r, ppd, ppd->visited);
3004 cp_walk_tree (&TYPENAME_TYPE_FULLNAME (t), &find_parameter_packs_r,
3009 case TYPE_PACK_EXPANSION:
3010 case EXPR_PACK_EXPANSION:
3015 cp_walk_tree (&TYPE_MAX_VALUE (t), &find_parameter_packs_r,
3020 case IDENTIFIER_NODE:
3021 cp_walk_tree (&TREE_TYPE (t), &find_parameter_packs_r, ppd,
3033 /* Determines if the expression or type T uses any parameter packs. */
3035 uses_parameter_packs (tree t)
3037 tree parameter_packs = NULL_TREE;
3038 struct find_parameter_pack_data ppd;
3039 ppd.parameter_packs = ¶meter_packs;
3040 ppd.visited = pointer_set_create ();
3041 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
3042 pointer_set_destroy (ppd.visited);
3043 return parameter_packs != NULL_TREE;
3046 /* Turn ARG, which may be an expression, type, or a TREE_LIST
3047 representation a base-class initializer into a parameter pack
3048 expansion. If all goes well, the resulting node will be an
3049 EXPR_PACK_EXPANSION, TYPE_PACK_EXPANSION, or TREE_LIST,
3052 make_pack_expansion (tree arg)
3055 tree parameter_packs = NULL_TREE;
3056 bool for_types = false;
3057 struct find_parameter_pack_data ppd;
3059 if (!arg || arg == error_mark_node)
3062 if (TREE_CODE (arg) == TREE_LIST)
3064 /* The only time we will see a TREE_LIST here is for a base
3065 class initializer. In this case, the TREE_PURPOSE will be a
3066 _TYPE node (representing the base class expansion we're
3067 initializing) and the TREE_VALUE will be a TREE_LIST
3068 containing the initialization arguments.
3070 The resulting expansion looks somewhat different from most
3071 expansions. Rather than returning just one _EXPANSION, we
3072 return a TREE_LIST whose TREE_PURPOSE is a
3073 TYPE_PACK_EXPANSION containing the bases that will be
3074 initialized. The TREE_VALUE will be identical to the
3075 original TREE_VALUE, which is a list of arguments that will
3076 be passed to each base. We do not introduce any new pack
3077 expansion nodes into the TREE_VALUE (although it is possible
3078 that some already exist), because the TREE_PURPOSE and
3079 TREE_VALUE all need to be expanded together with the same
3080 _EXPANSION node. Note that the TYPE_PACK_EXPANSION in the
3081 resulting TREE_PURPOSE will mention the parameter packs in
3082 both the bases and the arguments to the bases. */
3085 tree parameter_packs = NULL_TREE;
3087 /* Determine which parameter packs will be used by the base
3089 ppd.visited = pointer_set_create ();
3090 ppd.parameter_packs = ¶meter_packs;
3091 cp_walk_tree (&TREE_PURPOSE (arg), &find_parameter_packs_r,
3094 if (parameter_packs == NULL_TREE)
3096 error ("base initializer expansion %<%T%> contains no parameter packs", arg);
3097 pointer_set_destroy (ppd.visited);
3098 return error_mark_node;
3101 if (TREE_VALUE (arg) != void_type_node)
3103 /* Collect the sets of parameter packs used in each of the
3104 initialization arguments. */
3105 for (value = TREE_VALUE (arg); value; value = TREE_CHAIN (value))
3107 /* Determine which parameter packs will be expanded in this
3109 cp_walk_tree (&TREE_VALUE (value), &find_parameter_packs_r,
3114 pointer_set_destroy (ppd.visited);
3116 /* Create the pack expansion type for the base type. */
3117 purpose = cxx_make_type (TYPE_PACK_EXPANSION);
3118 SET_PACK_EXPANSION_PATTERN (purpose, TREE_PURPOSE (arg));
3119 PACK_EXPANSION_PARAMETER_PACKS (purpose) = parameter_packs;
3121 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3122 they will rarely be compared to anything. */
3123 SET_TYPE_STRUCTURAL_EQUALITY (purpose);
3125 return tree_cons (purpose, TREE_VALUE (arg), NULL_TREE);
3128 if (TYPE_P (arg) || TREE_CODE (arg) == TEMPLATE_DECL)
3131 /* Build the PACK_EXPANSION_* node. */
3133 ? cxx_make_type (TYPE_PACK_EXPANSION)
3134 : make_node (EXPR_PACK_EXPANSION);
3135 SET_PACK_EXPANSION_PATTERN (result, arg);
3136 if (TREE_CODE (result) == EXPR_PACK_EXPANSION)
3138 /* Propagate type and const-expression information. */
3139 TREE_TYPE (result) = TREE_TYPE (arg);
3140 TREE_CONSTANT (result) = TREE_CONSTANT (arg);
3143 /* Just use structural equality for these TYPE_PACK_EXPANSIONS;
3144 they will rarely be compared to anything. */
3145 SET_TYPE_STRUCTURAL_EQUALITY (result);
3147 /* Determine which parameter packs will be expanded. */
3148 ppd.parameter_packs = ¶meter_packs;
3149 ppd.visited = pointer_set_create ();
3150 cp_walk_tree (&arg, &find_parameter_packs_r, &ppd, ppd.visited);
3151 pointer_set_destroy (ppd.visited);
3153 /* Make sure we found some parameter packs. */
3154 if (parameter_packs == NULL_TREE)
3157 error ("expansion pattern %<%T%> contains no argument packs", arg);
3159 error ("expansion pattern %<%E%> contains no argument packs", arg);
3160 return error_mark_node;
3162 PACK_EXPANSION_PARAMETER_PACKS (result) = parameter_packs;
3167 /* Checks T for any "bare" parameter packs, which have not yet been
3168 expanded, and issues an error if any are found. This operation can
3169 only be done on full expressions or types (e.g., an expression
3170 statement, "if" condition, etc.), because we could have expressions like:
3172 foo(f(g(h(args)))...)
3174 where "args" is a parameter pack. check_for_bare_parameter_packs
3175 should not be called for the subexpressions args, h(args),
3176 g(h(args)), or f(g(h(args))), because we would produce erroneous
3179 Returns TRUE and emits an error if there were bare parameter packs,
3180 returns FALSE otherwise. */
3182 check_for_bare_parameter_packs (tree t)
3184 tree parameter_packs = NULL_TREE;
3185 struct find_parameter_pack_data ppd;
3187 if (!processing_template_decl || !t || t == error_mark_node)
3190 if (TREE_CODE (t) == TYPE_DECL)
3193 ppd.parameter_packs = ¶meter_packs;
3194 ppd.visited = pointer_set_create ();
3195 cp_walk_tree (&t, &find_parameter_packs_r, &ppd, ppd.visited);
3196 pointer_set_destroy (ppd.visited);
3198 if (parameter_packs)
3200 error ("parameter packs not expanded with %<...%>:");
3201 while (parameter_packs)
3203 tree pack = TREE_VALUE (parameter_packs);
3204 tree name = NULL_TREE;
3206 if (TREE_CODE (pack) == TEMPLATE_TYPE_PARM
3207 || TREE_CODE (pack) == TEMPLATE_TEMPLATE_PARM)
3208 name = TYPE_NAME (pack);
3209 else if (TREE_CODE (pack) == TEMPLATE_PARM_INDEX)
3210 name = DECL_NAME (TEMPLATE_PARM_DECL (pack));
3212 name = DECL_NAME (pack);
3215 inform (input_location, " %qD", name);
3217 inform (input_location, " <anonymous>");
3219 parameter_packs = TREE_CHAIN (parameter_packs);
3228 /* Expand any parameter packs that occur in the template arguments in
3231 expand_template_argument_pack (tree args)
3233 tree result_args = NULL_TREE;
3234 int in_arg, out_arg = 0, nargs = args ? TREE_VEC_LENGTH (args) : 0;
3235 int num_result_args = -1;
3236 int non_default_args_count = -1;
3238 /* First, determine if we need to expand anything, and the number of
3239 slots we'll need. */
3240 for (in_arg = 0; in_arg < nargs; ++in_arg)
3242 tree arg = TREE_VEC_ELT (args, in_arg);
3243 if (arg == NULL_TREE)
3245 if (ARGUMENT_PACK_P (arg))
3247 int num_packed = TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg));
3248 if (num_result_args < 0)
3249 num_result_args = in_arg + num_packed;
3251 num_result_args += num_packed;
3255 if (num_result_args >= 0)
3260 /* If no expansion is necessary, we're done. */
3261 if (num_result_args < 0)
3264 /* Expand arguments. */
3265 result_args = make_tree_vec (num_result_args);
3266 if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (args))
3267 non_default_args_count =
3268 GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (args);
3269 for (in_arg = 0; in_arg < nargs; ++in_arg)
3271 tree arg = TREE_VEC_ELT (args, in_arg);
3272 if (ARGUMENT_PACK_P (arg))
3274 tree packed = ARGUMENT_PACK_ARGS (arg);
3275 int i, num_packed = TREE_VEC_LENGTH (packed);
3276 for (i = 0; i < num_packed; ++i, ++out_arg)
3277 TREE_VEC_ELT (result_args, out_arg) = TREE_VEC_ELT(packed, i);
3278 if (non_default_args_count > 0)
3279 non_default_args_count += num_packed;
3283 TREE_VEC_ELT (result_args, out_arg) = arg;
3287 if (non_default_args_count >= 0)
3288 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (result_args, non_default_args_count);
3292 /* Checks if DECL shadows a template parameter.
3294 [temp.local]: A template-parameter shall not be redeclared within its
3295 scope (including nested scopes).
3297 Emits an error and returns TRUE if the DECL shadows a parameter,
3298 returns FALSE otherwise. */
3301 check_template_shadow (tree decl)
3305 /* If we're not in a template, we can't possibly shadow a template
3307 if (!current_template_parms)
3310 /* Figure out what we're shadowing. */
3311 if (TREE_CODE (decl) == OVERLOAD)
3312 decl = OVL_CURRENT (decl);
3313 olddecl = innermost_non_namespace_value (DECL_NAME (decl));
3315 /* If there's no previous binding for this name, we're not shadowing
3316 anything, let alone a template parameter. */
3320 /* If we're not shadowing a template parameter, we're done. Note
3321 that OLDDECL might be an OVERLOAD (or perhaps even an
3322 ERROR_MARK), so we can't just blithely assume it to be a _DECL
3324 if (!DECL_P (olddecl) || !DECL_TEMPLATE_PARM_P (olddecl))
3327 /* We check for decl != olddecl to avoid bogus errors for using a
3328 name inside a class. We check TPFI to avoid duplicate errors for
3329 inline member templates. */
3331 || TEMPLATE_PARMS_FOR_INLINE (current_template_parms))
3334 error ("declaration of %q+#D", decl);
3335 error (" shadows template parm %q+#D", olddecl);
3339 /* Return a new TEMPLATE_PARM_INDEX with the indicated INDEX, LEVEL,
3340 ORIG_LEVEL, DECL, and TYPE. */
3343 build_template_parm_index (int index,
3349 tree t = make_node (TEMPLATE_PARM_INDEX);
3350 TEMPLATE_PARM_IDX (t) = index;
3351 TEMPLATE_PARM_LEVEL (t) = level;
3352 TEMPLATE_PARM_ORIG_LEVEL (t) = orig_level;
3353 TEMPLATE_PARM_DECL (t) = decl;
3354 TREE_TYPE (t) = type;
3355 TREE_CONSTANT (t) = TREE_CONSTANT (decl);
3356 TREE_READONLY (t) = TREE_READONLY (decl);
3361 /* Find the canonical type parameter for the given template type
3362 parameter. Returns the canonical type parameter, which may be TYPE
3363 if no such parameter existed. */
3365 canonical_type_parameter (tree type)
3368 int idx = TEMPLATE_TYPE_IDX (type);
3369 if (!canonical_template_parms)
3370 canonical_template_parms = VEC_alloc (tree, gc, idx+1);
3372 while (VEC_length (tree, canonical_template_parms) <= (unsigned)idx)
3373 VEC_safe_push (tree, gc, canonical_template_parms, NULL_TREE);
3375 list = VEC_index (tree, canonical_template_parms, idx);
3376 while (list && !comptypes (type, TREE_VALUE (list), COMPARE_STRUCTURAL))
3377 list = TREE_CHAIN (list);
3380 return TREE_VALUE (list);
3383 VEC_replace(tree, canonical_template_parms, idx,
3384 tree_cons (NULL_TREE, type,
3385 VEC_index (tree, canonical_template_parms, idx)));
3390 /* Return a TEMPLATE_PARM_INDEX, similar to INDEX, but whose
3391 TEMPLATE_PARM_LEVEL has been decreased by LEVELS. If such a
3392 TEMPLATE_PARM_INDEX already exists, it is returned; otherwise, a
3393 new one is created. */
3396 reduce_template_parm_level (tree index, tree type, int levels, tree args,
3397 tsubst_flags_t complain)
3399 if (TEMPLATE_PARM_DESCENDANTS (index) == NULL_TREE
3400 || (TEMPLATE_PARM_LEVEL (TEMPLATE_PARM_DESCENDANTS (index))
3401 != TEMPLATE_PARM_LEVEL (index) - levels)
3402 || !same_type_p (type, TREE_TYPE (TEMPLATE_PARM_DESCENDANTS (index))))
3404 tree orig_decl = TEMPLATE_PARM_DECL (index);
3407 decl = build_decl (DECL_SOURCE_LOCATION (orig_decl),
3408 TREE_CODE (orig_decl), DECL_NAME (orig_decl), type);
3409 TREE_CONSTANT (decl) = TREE_CONSTANT (orig_decl);
3410 TREE_READONLY (decl) = TREE_READONLY (orig_decl);
3411 DECL_ARTIFICIAL (decl) = 1;
3412 SET_DECL_TEMPLATE_PARM_P (decl);
3414 t = build_template_parm_index (TEMPLATE_PARM_IDX (index),
3415 TEMPLATE_PARM_LEVEL (index) - levels,
3416 TEMPLATE_PARM_ORIG_LEVEL (index),
3418 TEMPLATE_PARM_DESCENDANTS (index) = t;
3419 TEMPLATE_PARM_PARAMETER_PACK (t)
3420 = TEMPLATE_PARM_PARAMETER_PACK (index);
3422 /* Template template parameters need this. */
3423 if (TREE_CODE (decl) == TEMPLATE_DECL)
3424 DECL_TEMPLATE_PARMS (decl) = tsubst_template_parms
3425 (DECL_TEMPLATE_PARMS (TEMPLATE_PARM_DECL (index)),
3429 return TEMPLATE_PARM_DESCENDANTS (index);
3432 /* Process information from new template parameter PARM and append it to the
3433 LIST being built. This new parameter is a non-type parameter iff
3434 IS_NON_TYPE is true. This new parameter is a parameter
3435 pack iff IS_PARAMETER_PACK is true. The location of PARM is in
3439 process_template_parm (tree list, location_t parm_loc, tree parm, bool is_non_type,
3440 bool is_parameter_pack)
3447 gcc_assert (TREE_CODE (parm) == TREE_LIST);
3448 defval = TREE_PURPOSE (parm);
3452 tree p = tree_last (list);
3454 if (p && TREE_VALUE (p) != error_mark_node)
3457 if (TREE_CODE (p) == TYPE_DECL || TREE_CODE (p) == TEMPLATE_DECL)
3458 idx = TEMPLATE_TYPE_IDX (TREE_TYPE (p));
3460 idx = TEMPLATE_PARM_IDX (DECL_INITIAL (p));
3470 parm = TREE_VALUE (parm);
3472 SET_DECL_TEMPLATE_PARM_P (parm);
3474 if (TREE_TYPE (parm) == error_mark_node)
3476 err_parm_list = build_tree_list (defval, parm);
3477 TREE_VALUE (err_parm_list) = error_mark_node;
3478 return chainon (list, err_parm_list);
3484 The top-level cv-qualifiers on the template-parameter are
3485 ignored when determining its type. */
3486 TREE_TYPE (parm) = TYPE_MAIN_VARIANT (TREE_TYPE (parm));
3487 if (invalid_nontype_parm_type_p (TREE_TYPE (parm), 1))
3489 err_parm_list = build_tree_list (defval, parm);
3490 TREE_VALUE (err_parm_list) = error_mark_node;
3491 return chainon (list, err_parm_list);
3494 if (uses_parameter_packs (TREE_TYPE (parm)) && !is_parameter_pack)
3496 /* This template parameter is not a parameter pack, but it
3497 should be. Complain about "bare" parameter packs. */
3498 check_for_bare_parameter_packs (TREE_TYPE (parm));
3500 /* Recover by calling this a parameter pack. */
3501 is_parameter_pack = true;
3505 /* A template parameter is not modifiable. */
3506 TREE_CONSTANT (parm) = 1;
3507 TREE_READONLY (parm) = 1;
3508 decl = build_decl (parm_loc,
3509 CONST_DECL, DECL_NAME (parm), TREE_TYPE (parm));
3510 TREE_CONSTANT (decl) = 1;
3511 TREE_READONLY (decl) = 1;
3512 DECL_INITIAL (parm) = DECL_INITIAL (decl)
3513 = build_template_parm_index (idx, processing_template_decl,
3514 processing_template_decl,
3515 decl, TREE_TYPE (parm));
3517 TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm))
3518 = is_parameter_pack;
3523 parm = TREE_VALUE (TREE_VALUE (parm));
3525 if (parm && TREE_CODE (parm) == TEMPLATE_DECL)
3527 t = cxx_make_type (TEMPLATE_TEMPLATE_PARM);
3528 /* This is for distinguishing between real templates and template
3529 template parameters */
3530 TREE_TYPE (parm) = t;
3531 TREE_TYPE (DECL_TEMPLATE_RESULT (parm)) = t;
3536 t = cxx_make_type (TEMPLATE_TYPE_PARM);
3537 /* parm is either IDENTIFIER_NODE or NULL_TREE. */
3538 decl = build_decl (parm_loc,
3539 TYPE_DECL, parm, t);
3542 TYPE_NAME (t) = decl;
3543 TYPE_STUB_DECL (t) = decl;
3545 TEMPLATE_TYPE_PARM_INDEX (t)
3546 = build_template_parm_index (idx, processing_template_decl,
3547 processing_template_decl,
3548 decl, TREE_TYPE (parm));
3549 TEMPLATE_TYPE_PARAMETER_PACK (t) = is_parameter_pack;
3550 TYPE_CANONICAL (t) = canonical_type_parameter (t);
3552 DECL_ARTIFICIAL (decl) = 1;
3553 SET_DECL_TEMPLATE_PARM_P (decl);
3555 parm = build_tree_list (defval, parm);
3556 return chainon (list, parm);
3559 /* The end of a template parameter list has been reached. Process the
3560 tree list into a parameter vector, converting each parameter into a more
3561 useful form. Type parameters are saved as IDENTIFIER_NODEs, and others
3565 end_template_parm_list (tree parms)
3569 tree saved_parmlist = make_tree_vec (list_length (parms));
3571 current_template_parms
3572 = tree_cons (size_int (processing_template_decl),
3573 saved_parmlist, current_template_parms);
3575 for (parm = parms, nparms = 0; parm; parm = next, nparms++)
3577 next = TREE_CHAIN (parm);
3578 TREE_VEC_ELT (saved_parmlist, nparms) = parm;
3579 TREE_CHAIN (parm) = NULL_TREE;
3580 if (TREE_CODE (TREE_VALUE (parm)) == TYPE_DECL)
3581 TEMPLATE_TYPE_PARM_SIBLING_PARMS (TREE_TYPE (TREE_VALUE (parm))) =
3582 current_template_parms;
3585 --processing_template_parmlist;
3587 return saved_parmlist;
3590 /* end_template_decl is called after a template declaration is seen. */
3593 end_template_decl (void)
3595 reset_specialization ();
3597 if (! processing_template_decl)
3600 /* This matches the pushlevel in begin_template_parm_list. */
3603 --processing_template_decl;
3604 current_template_parms = TREE_CHAIN (current_template_parms);
3607 /* Within the declaration of a template, return all levels of template
3608 parameters that apply. The template parameters are represented as
3609 a TREE_VEC, in the form documented in cp-tree.h for template
3613 current_template_args (void)
3616 tree args = NULL_TREE;
3617 int length = TMPL_PARMS_DEPTH (current_template_parms);
3620 /* If there is only one level of template parameters, we do not
3621 create a TREE_VEC of TREE_VECs. Instead, we return a single
3622 TREE_VEC containing the arguments. */
3624 args = make_tree_vec (length);
3626 for (header = current_template_parms; header; header = TREE_CHAIN (header))
3628 tree a = copy_node (TREE_VALUE (header));
3631 TREE_TYPE (a) = NULL_TREE;
3632 for (i = TREE_VEC_LENGTH (a) - 1; i >= 0; --i)
3634 tree t = TREE_VEC_ELT (a, i);
3636 /* T will be a list if we are called from within a
3637 begin/end_template_parm_list pair, but a vector directly
3638 if within a begin/end_member_template_processing pair. */
3639 if (TREE_CODE (t) == TREE_LIST)
3643 if (!error_operand_p (t))
3645 if (TREE_CODE (t) == TYPE_DECL
3646 || TREE_CODE (t) == TEMPLATE_DECL)
3650 if (TEMPLATE_TYPE_PARAMETER_PACK (t))
3652 /* Turn this argument into a TYPE_ARGUMENT_PACK
3653 with a single element, which expands T. */
3654 tree vec = make_tree_vec (1);
3655 #ifdef ENABLE_CHECKING
3656 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3657 (vec, TREE_VEC_LENGTH (vec));
3659 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
3661 t = cxx_make_type (TYPE_ARGUMENT_PACK);
3662 SET_ARGUMENT_PACK_ARGS (t, vec);
3667 t = DECL_INITIAL (t);
3669 if (TEMPLATE_PARM_PARAMETER_PACK (t))
3671 /* Turn this argument into a NONTYPE_ARGUMENT_PACK
3672 with a single element, which expands T. */
3673 tree vec = make_tree_vec (1);
3674 tree type = TREE_TYPE (TEMPLATE_PARM_DECL (t));
3675 #ifdef ENABLE_CHECKING
3676 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT
3677 (vec, TREE_VEC_LENGTH (vec));
3679 TREE_VEC_ELT (vec, 0) = make_pack_expansion (t);
3681 t = make_node (NONTYPE_ARGUMENT_PACK);
3682 SET_ARGUMENT_PACK_ARGS (t, vec);
3683 TREE_TYPE (t) = type;
3686 TREE_VEC_ELT (a, i) = t;
3691 #ifdef ENABLE_CHECKING
3692 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (a, TREE_VEC_LENGTH (a));
3696 TREE_VEC_ELT (args, --l) = a;
3704 /* Update the declared TYPE by doing any lookups which were thought to be
3705 dependent, but are not now that we know the SCOPE of the declarator. */
3708 maybe_update_decl_type (tree orig_type, tree scope)
3710 tree type = orig_type;
3712 if (type == NULL_TREE)
3715 if (TREE_CODE (orig_type) == TYPE_DECL)
3716 type = TREE_TYPE (type);
3718 if (scope && TYPE_P (scope) && dependent_type_p (scope)
3719 && dependent_type_p (type)
3720 /* Don't bother building up the args in this case. */
3721 && TREE_CODE (type) != TEMPLATE_TYPE_PARM)
3723 /* tsubst in the args corresponding to the template parameters,
3724 including auto if present. Most things will be unchanged, but
3725 make_typename_type and tsubst_qualified_id will resolve
3726 TYPENAME_TYPEs and SCOPE_REFs that were previously dependent. */
3727 tree args = current_template_args ();
3728 tree auto_node = type_uses_auto (type);
3732 tree auto_vec = make_tree_vec (1);
3733 TREE_VEC_ELT (auto_vec, 0) = auto_node;
3734 args = add_to_template_args (args, auto_vec);
3736 pushed = push_scope (scope);
3737 type = tsubst (type, args, tf_warning_or_error, NULL_TREE);
3742 if (type == error_mark_node)
3745 if (TREE_CODE (orig_type) == TYPE_DECL)
3747 if (same_type_p (type, TREE_TYPE (orig_type)))
3750 type = TYPE_NAME (type);
3755 /* Return a TEMPLATE_DECL corresponding to DECL, using the indicated
3756 template PARMS. If MEMBER_TEMPLATE_P is true, the new template is
3757 a member template. Used by push_template_decl below. */
3760 build_template_decl (tree decl, tree parms, bool member_template_p)
3762 tree tmpl = build_lang_decl (TEMPLATE_DECL, DECL_NAME (decl), NULL_TREE);
3763 DECL_TEMPLATE_PARMS (tmpl) = parms;
3764 DECL_CONTEXT (tmpl) = DECL_CONTEXT (decl);
3765 DECL_MEMBER_TEMPLATE_P (tmpl) = member_template_p;
3770 struct template_parm_data
3772 /* The level of the template parameters we are currently
3776 /* The index of the specialization argument we are currently
3780 /* An array whose size is the number of template parameters. The
3781 elements are nonzero if the parameter has been used in any one
3782 of the arguments processed so far. */
3785 /* An array whose size is the number of template arguments. The
3786 elements are nonzero if the argument makes use of template
3787 parameters of this level. */
3788 int* arg_uses_template_parms;
3791 /* Subroutine of push_template_decl used to see if each template
3792 parameter in a partial specialization is used in the explicit
3793 argument list. If T is of the LEVEL given in DATA (which is
3794 treated as a template_parm_data*), then DATA->PARMS is marked
3798 mark_template_parm (tree t, void* data)
3802 struct template_parm_data* tpd = (struct template_parm_data*) data;
3804 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
3806 level = TEMPLATE_PARM_LEVEL (t);
3807 idx = TEMPLATE_PARM_IDX (t);
3811 level = TEMPLATE_TYPE_LEVEL (t);
3812 idx = TEMPLATE_TYPE_IDX (t);
3815 if (level == tpd->level)
3817 tpd->parms[idx] = 1;
3818 tpd->arg_uses_template_parms[tpd->current_arg] = 1;
3821 /* Return zero so that for_each_template_parm will continue the
3822 traversal of the tree; we want to mark *every* template parm. */
3826 /* Process the partial specialization DECL. */
3829 process_partial_specialization (tree decl)
3831 tree type = TREE_TYPE (decl);
3832 tree maintmpl = CLASSTYPE_TI_TEMPLATE (type);
3833 tree specargs = CLASSTYPE_TI_ARGS (type);
3834 tree inner_args = INNERMOST_TEMPLATE_ARGS (specargs);
3835 tree main_inner_parms = DECL_INNERMOST_TEMPLATE_PARMS (maintmpl);
3837 int nargs = TREE_VEC_LENGTH (inner_args);
3840 bool did_error_intro = false;
3841 struct template_parm_data tpd;
3842 struct template_parm_data tpd2;
3844 gcc_assert (current_template_parms);
3846 inner_parms = INNERMOST_TEMPLATE_PARMS (current_template_parms);
3847 ntparms = TREE_VEC_LENGTH (inner_parms);
3849 /* We check that each of the template parameters given in the
3850 partial specialization is used in the argument list to the
3851 specialization. For example:
3853 template <class T> struct S;
3854 template <class T> struct S<T*>;
3856 The second declaration is OK because `T*' uses the template
3857 parameter T, whereas
3859 template <class T> struct S<int>;
3861 is no good. Even trickier is:
3872 The S2<T> declaration is actually invalid; it is a
3873 full-specialization. Of course,
3876 struct S2<T (*)(U)>;
3878 or some such would have been OK. */
3879 tpd.level = TMPL_PARMS_DEPTH (current_template_parms);
3880 tpd.parms = (int *) alloca (sizeof (int) * ntparms);
3881 memset (tpd.parms, 0, sizeof (int) * ntparms);
3883 tpd.arg_uses_template_parms = (int *) alloca (sizeof (int) * nargs);
3884 memset (tpd.arg_uses_template_parms, 0, sizeof (int) * nargs);
3885 for (i = 0; i < nargs; ++i)
3887 tpd.current_arg = i;
3888 for_each_template_parm (TREE_VEC_ELT (inner_args, i),
3889 &mark_template_parm,
3892 /*include_nondeduced_p=*/false);
3894 for (i = 0; i < ntparms; ++i)
3895 if (tpd.parms[i] == 0)
3897 /* One of the template parms was not used in the
3899 if (!did_error_intro)
3901 error ("template parameters not used in partial specialization:");
3902 did_error_intro = true;
3905 error (" %qD", TREE_VALUE (TREE_VEC_ELT (inner_parms, i)));
3908 if (did_error_intro)
3909 return error_mark_node;
3911 /* [temp.class.spec]
3913 The argument list of the specialization shall not be identical to
3914 the implicit argument list of the primary template. */
3915 if (comp_template_args
3917 INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE
3919 error ("partial specialization %qT does not specialize any template arguments", type);
3921 /* [temp.class.spec]
3923 A partially specialized non-type argument expression shall not
3924 involve template parameters of the partial specialization except
3925 when the argument expression is a simple identifier.
3927 The type of a template parameter corresponding to a specialized
3928 non-type argument shall not be dependent on a parameter of the
3931 Also, we verify that pack expansions only occur at the
3932 end of the argument list. */
3933 gcc_assert (nargs == DECL_NTPARMS (maintmpl));
3935 for (i = 0; i < nargs; ++i)
3937 tree parm = TREE_VALUE (TREE_VEC_ELT (main_inner_parms, i));
3938 tree arg = TREE_VEC_ELT (inner_args, i);
3939 tree packed_args = NULL_TREE;
3942 if (ARGUMENT_PACK_P (arg))
3944 /* Extract the arguments from the argument pack. We'll be
3945 iterating over these in the following loop. */
3946 packed_args = ARGUMENT_PACK_ARGS (arg);
3947 len = TREE_VEC_LENGTH (packed_args);
3950 for (j = 0; j < len; j++)
3953 /* Get the Jth argument in the parameter pack. */
3954 arg = TREE_VEC_ELT (packed_args, j);
3956 if (PACK_EXPANSION_P (arg))
3958 /* Pack expansions must come at the end of the
3960 if ((packed_args && j < len - 1)
3961 || (!packed_args && i < nargs - 1))
3963 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
3964 error ("parameter pack argument %qE must be at the "
3965 "end of the template argument list", arg);
3967 error ("parameter pack argument %qT must be at the "
3968 "end of the template argument list", arg);
3972 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
3973 /* We only care about the pattern. */
3974 arg = PACK_EXPANSION_PATTERN (arg);
3976 if (/* These first two lines are the `non-type' bit. */
3978 && TREE_CODE (arg) != TEMPLATE_DECL
3979 /* This next line is the `argument expression is not just a
3980 simple identifier' condition and also the `specialized
3981 non-type argument' bit. */
3982 && TREE_CODE (arg) != TEMPLATE_PARM_INDEX)
3984 if ((!packed_args && tpd.arg_uses_template_parms[i])
3985 || (packed_args && uses_template_parms (arg)))
3986 error ("template argument %qE involves template parameter(s)",
3990 /* Look at the corresponding template parameter,
3991 marking which template parameters its type depends
3993 tree type = TREE_TYPE (parm);
3997 /* We haven't yet initialized TPD2. Do so now. */
3998 tpd2.arg_uses_template_parms
3999 = (int *) alloca (sizeof (int) * nargs);
4000 /* The number of parameters here is the number in the
4001 main template, which, as checked in the assertion
4003 tpd2.parms = (int *) alloca (sizeof (int) * nargs);
4005 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (maintmpl));
4008 /* Mark the template parameters. But this time, we're
4009 looking for the template parameters of the main
4010 template, not in the specialization. */
4011 tpd2.current_arg = i;
4012 tpd2.arg_uses_template_parms[i] = 0;
4013 memset (tpd2.parms, 0, sizeof (int) * nargs);
4014 for_each_template_parm (type,
4015 &mark_template_parm,
4018 /*include_nondeduced_p=*/false);
4020 if (tpd2.arg_uses_template_parms [i])
4022 /* The type depended on some template parameters.
4023 If they are fully specialized in the
4024 specialization, that's OK. */
4027 for (j = 0; j < nargs; ++j)
4028 if (tpd2.parms[j] != 0
4029 && tpd.arg_uses_template_parms [j])
4032 error_n (input_location, count,
4033 "type %qT of template argument %qE depends "
4034 "on a template parameter",
4035 "type %qT of template argument %qE depends "
4036 "on template parameters",
4045 /* We should only get here once. */
4046 gcc_assert (!COMPLETE_TYPE_P (type));
4048 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)
4049 = tree_cons (specargs, inner_parms,
4050 DECL_TEMPLATE_SPECIALIZATIONS (maintmpl));
4051 TREE_TYPE (DECL_TEMPLATE_SPECIALIZATIONS (maintmpl)) = type;
4055 /* Check that a template declaration's use of default arguments and
4056 parameter packs is not invalid. Here, PARMS are the template
4057 parameters. IS_PRIMARY is nonzero if DECL is the thing declared by
4058 a primary template. IS_PARTIAL is nonzero if DECL is a partial
4062 IS_FRIEND_DECL is nonzero if DECL is a friend function template
4063 declaration (but not a definition); 1 indicates a declaration, 2
4064 indicates a redeclaration. When IS_FRIEND_DECL=2, no errors are
4065 emitted for extraneous default arguments.
4067 Returns TRUE if there were no errors found, FALSE otherwise. */
4070 check_default_tmpl_args (tree decl, tree parms, int is_primary,
4071 int is_partial, int is_friend_decl)
4074 int last_level_to_check;
4076 bool no_errors = true;
4080 A default template-argument shall not be specified in a
4081 function template declaration or a function template definition, nor
4082 in the template-parameter-list of the definition of a member of a
4085 if (TREE_CODE (CP_DECL_CONTEXT (decl)) == FUNCTION_DECL)
4086 /* You can't have a function template declaration in a local
4087 scope, nor you can you define a member of a class template in a
4091 if (current_class_type
4092 && !TYPE_BEING_DEFINED (current_class_type)
4093 && DECL_LANG_SPECIFIC (decl)
4094 && DECL_DECLARES_FUNCTION_P (decl)
4095 /* If this is either a friend defined in the scope of the class
4096 or a member function. */
4097 && (DECL_FUNCTION_MEMBER_P (decl)
4098 ? same_type_p (DECL_CONTEXT (decl), current_class_type)
4099 : DECL_FRIEND_CONTEXT (decl)
4100 ? same_type_p (DECL_FRIEND_CONTEXT (decl), current_class_type)
4102 /* And, if it was a member function, it really was defined in
4103 the scope of the class. */
4104 && (!DECL_FUNCTION_MEMBER_P (decl)
4105 || DECL_INITIALIZED_IN_CLASS_P (decl)))
4106 /* We already checked these parameters when the template was
4107 declared, so there's no need to do it again now. This function
4108 was defined in class scope, but we're processing it's body now
4109 that the class is complete. */
4112 /* Core issue 226 (C++0x only): the following only applies to class
4114 if ((cxx_dialect == cxx98) || TREE_CODE (decl) != FUNCTION_DECL)
4118 If a template-parameter has a default template-argument, all
4119 subsequent template-parameters shall have a default
4120 template-argument supplied. */
4121 for (parm_level = parms; parm_level; parm_level = TREE_CHAIN (parm_level))
4123 tree inner_parms = TREE_VALUE (parm_level);
4124 int ntparms = TREE_VEC_LENGTH (inner_parms);
4125 int seen_def_arg_p = 0;
4128 for (i = 0; i < ntparms; ++i)
4130 tree parm = TREE_VEC_ELT (inner_parms, i);
4132 if (parm == error_mark_node)
4135 if (TREE_PURPOSE (parm))
4137 else if (seen_def_arg_p
4138 && !template_parameter_pack_p (TREE_VALUE (parm)))
4140 error ("no default argument for %qD", TREE_VALUE (parm));
4141 /* For better subsequent error-recovery, we indicate that
4142 there should have been a default argument. */
4143 TREE_PURPOSE (parm) = error_mark_node;
4149 /* Don't complain about an enclosing partial
4151 && parm_level == parms
4152 && TREE_CODE (decl) == TYPE_DECL
4154 && template_parameter_pack_p (TREE_VALUE (parm)))
4156 /* A primary class template can only have one
4157 parameter pack, at the end of the template
4160 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL)
4161 error ("parameter pack %qE must be at the end of the"
4162 " template parameter list", TREE_VALUE (parm));
4164 error ("parameter pack %qT must be at the end of the"
4165 " template parameter list",
4166 TREE_TYPE (TREE_VALUE (parm)));
4168 TREE_VALUE (TREE_VEC_ELT (inner_parms, i))
4176 if (((cxx_dialect == cxx98) && TREE_CODE (decl) != TYPE_DECL)
4180 /* For an ordinary class template, default template arguments are
4181 allowed at the innermost level, e.g.:
4182 template <class T = int>
4184 but, in a partial specialization, they're not allowed even
4185 there, as we have in [temp.class.spec]:
4187 The template parameter list of a specialization shall not
4188 contain default template argument values.
4190 So, for a partial specialization, or for a function template
4191 (in C++98/C++03), we look at all of them. */
4194 /* But, for a primary class template that is not a partial
4195 specialization we look at all template parameters except the
4197 parms = TREE_CHAIN (parms);
4199 /* Figure out what error message to issue. */
4200 if (is_friend_decl == 2)
4201 msg = G_("default template arguments may not be used in function template "
4202 "friend re-declaration");
4203 else if (is_friend_decl)
4204 msg = G_("default template arguments may not be used in function template "
4205 "friend declarations");
4206 else if (TREE_CODE (decl) == FUNCTION_DECL && (cxx_dialect == cxx98))
4207 msg = G_("default template arguments may not be used in function templates "
4208 "without -std=c++0x or -std=gnu++0x");
4209 else if (is_partial)
4210 msg = G_("default template arguments may not be used in "
4211 "partial specializations");
4213 msg = G_("default argument for template parameter for class enclosing %qD");
4215 if (current_class_type && TYPE_BEING_DEFINED (current_class_type))
4216 /* If we're inside a class definition, there's no need to
4217 examine the parameters to the class itself. On the one
4218 hand, they will be checked when the class is defined, and,
4219 on the other, default arguments are valid in things like:
4220 template <class T = double>
4221 struct S { template <class U> void f(U); };
4222 Here the default argument for `S' has no bearing on the
4223 declaration of `f'. */
4224 last_level_to_check = template_class_depth (current_class_type) + 1;
4226 /* Check everything. */
4227 last_level_to_check = 0;
4229 for (parm_level = parms;
4230 parm_level && TMPL_PARMS_DEPTH (parm_level) >= last_level_to_check;
4231 parm_level = TREE_CHAIN (parm_level))
4233 tree inner_parms = TREE_VALUE (parm_level);
4237 ntparms = TREE_VEC_LENGTH (inner_parms);
4238 for (i = 0; i < ntparms; ++i)
4240 if (TREE_VEC_ELT (inner_parms, i) == error_mark_node)
4243 if (TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)))
4248 if (is_friend_decl == 2)
4255 /* Clear out the default argument so that we are not
4257 TREE_PURPOSE (TREE_VEC_ELT (inner_parms, i)) = NULL_TREE;
4261 /* At this point, if we're still interested in issuing messages,
4262 they must apply to classes surrounding the object declared. */
4264 msg = G_("default argument for template parameter for class "
4271 /* Worker for push_template_decl_real, called via
4272 for_each_template_parm. DATA is really an int, indicating the
4273 level of the parameters we are interested in. If T is a template
4274 parameter of that level, return nonzero. */
4277 template_parm_this_level_p (tree t, void* data)
4279 int this_level = *(int *)data;
4282 if (TREE_CODE (t) == TEMPLATE_PARM_INDEX)
4283 level = TEMPLATE_PARM_LEVEL (t);
4285 level = TEMPLATE_TYPE_LEVEL (t);
4286 return level == this_level;
4289 /* Creates a TEMPLATE_DECL for the indicated DECL using the template
4290 parameters given by current_template_args, or reuses a
4291 previously existing one, if appropriate. Returns the DECL, or an
4292 equivalent one, if it is replaced via a call to duplicate_decls.
4294 If IS_FRIEND is true, DECL is a friend declaration. */
4297 push_template_decl_real (tree decl, bool is_friend)
4305 int new_template_p = 0;
4306 /* True if the template is a member template, in the sense of
4308 bool member_template_p = false;
4310 if (decl == error_mark_node || !current_template_parms)
4311 return error_mark_node;
4313 /* See if this is a partial specialization. */
4314 is_partial = (DECL_IMPLICIT_TYPEDEF_P (decl)
4315 && TREE_CODE (TREE_TYPE (decl)) != ENUMERAL_TYPE
4316 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)));
4318 if (TREE_CODE (decl) == FUNCTION_DECL && DECL_FRIEND_P (decl))
4322 /* For a friend, we want the context of the friend function, not
4323 the type of which it is a friend. */
4324 ctx = DECL_CONTEXT (decl);
4325 else if (CP_DECL_CONTEXT (decl)
4326 && TREE_CODE (CP_DECL_CONTEXT (decl)) != NAMESPACE_DECL)
4327 /* In the case of a virtual function, we want the class in which
4329 ctx = CP_DECL_CONTEXT (decl);
4331 /* Otherwise, if we're currently defining some class, the DECL
4332 is assumed to be a member of the class. */
4333 ctx = current_scope ();
4335 if (ctx && TREE_CODE (ctx) == NAMESPACE_DECL)
4338 if (!DECL_CONTEXT (decl))
4339 DECL_CONTEXT (decl) = FROB_CONTEXT (current_namespace);
4341 /* See if this is a primary template. */
4342 if (is_friend && ctx)
4343 /* A friend template that specifies a class context, i.e.
4344 template <typename T> friend void A<T>::f();
4348 primary = template_parm_scope_p ();
4352 if (DECL_CLASS_SCOPE_P (decl))
4353 member_template_p = true;
4354 if (TREE_CODE (decl) == TYPE_DECL
4355 && ANON_AGGRNAME_P (DECL_NAME (decl)))
4357 error ("template class without a name");
4358 return error_mark_node;
4360 else if (TREE_CODE (decl) == FUNCTION_DECL)
4362 if (DECL_DESTRUCTOR_P (decl))
4366 A destructor shall not be a member template. */
4367 error ("destructor %qD declared as member template", decl);
4368 return error_mark_node;
4370 if (NEW_DELETE_OPNAME_P (DECL_NAME (decl))
4371 && (!TYPE_ARG_TYPES (TREE_TYPE (decl))
4372 || TYPE_ARG_TYPES (TREE_TYPE (decl)) == void_list_node
4373 || !TREE_CHAIN (TYPE_ARG_TYPES (TREE_TYPE (decl)))
4374 || (TREE_CHAIN (TYPE_ARG_TYPES ((TREE_TYPE (decl))))
4375 == void_list_node)))
4377 /* [basic.stc.dynamic.allocation]
4379 An allocation function can be a function
4380 template. ... Template allocation functions shall
4381 have two or more parameters. */
4382 error ("invalid template declaration of %qD", decl);
4383 return error_mark_node;
4386 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4387 && CLASS_TYPE_P (TREE_TYPE (decl)))
4391 error ("template declaration of %q#D", decl);
4392 return error_mark_node;
4396 /* Check to see that the rules regarding the use of default
4397 arguments are not being violated. */
4398 check_default_tmpl_args (decl, current_template_parms,
4399 primary, is_partial, /*is_friend_decl=*/0);
4401 /* Ensure that there are no parameter packs in the type of this
4402 declaration that have not been expanded. */
4403 if (TREE_CODE (decl) == FUNCTION_DECL)
4405 /* Check each of the arguments individually to see if there are
4406 any bare parameter packs. */
4407 tree type = TREE_TYPE (decl);
4408 tree arg = DECL_ARGUMENTS (decl);
4409 tree argtype = TYPE_ARG_TYPES (type);
4411 while (arg && argtype)
4413 if (!FUNCTION_PARAMETER_PACK_P (arg)
4414 && check_for_bare_parameter_packs (TREE_TYPE (arg)))
4416 /* This is a PARM_DECL that contains unexpanded parameter
4417 packs. We have already complained about this in the
4418 check_for_bare_parameter_packs call, so just replace
4419 these types with ERROR_MARK_NODE. */
4420 TREE_TYPE (arg) = error_mark_node;
4421 TREE_VALUE (argtype) = error_mark_node;
4424 arg = TREE_CHAIN (arg);
4425 argtype = TREE_CHAIN (argtype);
4428 /* Check for bare parameter packs in the return type and the
4429 exception specifiers. */
4430 if (check_for_bare_parameter_packs (TREE_TYPE (type)))
4431 /* Errors were already issued, set return type to int
4432 as the frontend doesn't expect error_mark_node as
4434 TREE_TYPE (type) = integer_type_node;
4435 if (check_for_bare_parameter_packs (TYPE_RAISES_EXCEPTIONS (type)))
4436 TYPE_RAISES_EXCEPTIONS (type) = NULL_TREE;
4438 else if (check_for_bare_parameter_packs (TREE_TYPE (decl)))
4440 TREE_TYPE (decl) = error_mark_node;
4441 return error_mark_node;
4445 return process_partial_specialization (decl);
4447 args = current_template_args ();
4450 || TREE_CODE (ctx) == FUNCTION_DECL
4451 || (CLASS_TYPE_P (ctx) && TYPE_BEING_DEFINED (ctx))
4452 || (is_friend && !DECL_TEMPLATE_INFO (decl)))
4454 if (DECL_LANG_SPECIFIC (decl)
4455 && DECL_TEMPLATE_INFO (decl)
4456 && DECL_TI_TEMPLATE (decl))
4457 tmpl = DECL_TI_TEMPLATE (decl);
4458 /* If DECL is a TYPE_DECL for a class-template, then there won't
4459 be DECL_LANG_SPECIFIC. The information equivalent to
4460 DECL_TEMPLATE_INFO is found in TYPE_TEMPLATE_INFO instead. */
4461 else if (DECL_IMPLICIT_TYPEDEF_P (decl)
4462 && TYPE_TEMPLATE_INFO (TREE_TYPE (decl))
4463 && TYPE_TI_TEMPLATE (TREE_TYPE (decl)))
4465 /* Since a template declaration already existed for this
4466 class-type, we must be redeclaring it here. Make sure
4467 that the redeclaration is valid. */
4468 redeclare_class_template (TREE_TYPE (decl),
4469 current_template_parms);
4470 /* We don't need to create a new TEMPLATE_DECL; just use the
4471 one we already had. */
4472 tmpl = TYPE_TI_TEMPLATE (TREE_TYPE (decl));
4476 tmpl = build_template_decl (decl, current_template_parms,
4480 if (DECL_LANG_SPECIFIC (decl)
4481 && DECL_TEMPLATE_SPECIALIZATION (decl))
4483 /* A specialization of a member template of a template
4485 SET_DECL_TEMPLATE_SPECIALIZATION (tmpl);
4486 DECL_TEMPLATE_INFO (tmpl) = DECL_TEMPLATE_INFO (decl);
4487 DECL_TEMPLATE_INFO (decl) = NULL_TREE;
4493 tree a, t, current, parms;
4495 tree tinfo = get_template_info (decl);
4499 error ("template definition of non-template %q#D", decl);
4500 return error_mark_node;
4503 tmpl = TI_TEMPLATE (tinfo);
4505 if (DECL_FUNCTION_TEMPLATE_P (tmpl)
4506 && DECL_TEMPLATE_INFO (decl) && DECL_TI_ARGS (decl)
4507 && DECL_TEMPLATE_SPECIALIZATION (decl)
4508 && DECL_MEMBER_TEMPLATE_P (tmpl))
4512 /* The declaration is a specialization of a member
4513 template, declared outside the class. Therefore, the
4514 innermost template arguments will be NULL, so we
4515 replace them with the arguments determined by the
4516 earlier call to check_explicit_specialization. */
4517 args = DECL_TI_ARGS (decl);
4520 = build_template_decl (decl, current_template_parms,
4522 DECL_TEMPLATE_RESULT (new_tmpl) = decl;
4523 TREE_TYPE (new_tmpl) = TREE_TYPE (decl);
4524 DECL_TI_TEMPLATE (decl) = new_tmpl;
4525 SET_DECL_TEMPLATE_SPECIALIZATION (new_tmpl);
4526 DECL_TEMPLATE_INFO (new_tmpl)
4527 = build_template_info (tmpl, args);
4529 register_specialization (new_tmpl,
4530 most_general_template (tmpl),
4536 /* Make sure the template headers we got make sense. */
4538 parms = DECL_TEMPLATE_PARMS (tmpl);
4539 i = TMPL_PARMS_DEPTH (parms);
4540 if (TMPL_ARGS_DEPTH (args) != i)
4542 error ("expected %d levels of template parms for %q#D, got %d",
4543 i, decl, TMPL_ARGS_DEPTH (args));
4546 for (current = decl; i > 0; --i, parms = TREE_CHAIN (parms))
4548 a = TMPL_ARGS_LEVEL (args, i);
4549 t = INNERMOST_TEMPLATE_PARMS (parms);
4551 if (TREE_VEC_LENGTH (t) != TREE_VEC_LENGTH (a))
4553 if (current == decl)
4554 error ("got %d template parameters for %q#D",
4555 TREE_VEC_LENGTH (a), decl);
4557 error ("got %d template parameters for %q#T",
4558 TREE_VEC_LENGTH (a), current);
4559 error (" but %d required", TREE_VEC_LENGTH (t));
4560 return error_mark_node;
4563 if (current == decl)
4565 else if (current == NULL_TREE)
4566 /* Can happen in erroneous input. */
4569 current = (TYPE_P (current)
4570 ? TYPE_CONTEXT (current)
4571 : DECL_CONTEXT (current));
4574 /* Check that the parms are used in the appropriate qualifying scopes
4575 in the declarator. */
4576 if (!comp_template_args
4578 TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (tmpl)))))
4581 template arguments to %qD do not match original template %qD",
4582 decl, DECL_TEMPLATE_RESULT (tmpl));
4583 if (!uses_template_parms (TI_ARGS (tinfo)))
4584 inform (input_location, "use template<> for an explicit specialization");
4585 /* Avoid crash in import_export_decl. */
4586 DECL_INTERFACE_KNOWN (decl) = 1;
4587 return error_mark_node;
4591 DECL_TEMPLATE_RESULT (tmpl) = decl;
4592 TREE_TYPE (tmpl) = TREE_TYPE (decl);
4594 /* Push template declarations for global functions and types. Note
4595 that we do not try to push a global template friend declared in a
4596 template class; such a thing may well depend on the template
4597 parameters of the class. */
4598 if (new_template_p && !ctx
4599 && !(is_friend && template_class_depth (current_class_type) > 0))
4601 tmpl = pushdecl_namespace_level (tmpl, is_friend);
4602 if (tmpl == error_mark_node)
4603 return error_mark_node;
4605 /* Hide template friend classes that haven't been declared yet. */
4606 if (is_friend && TREE_CODE (decl) == TYPE_DECL)
4608 DECL_ANTICIPATED (tmpl) = 1;
4609 DECL_FRIEND_P (tmpl) = 1;
4615 tree parms = DECL_TEMPLATE_PARMS (tmpl);
4618 DECL_PRIMARY_TEMPLATE (tmpl) = tmpl;
4619 if (DECL_CONV_FN_P (tmpl))
4621 int depth = TMPL_PARMS_DEPTH (parms);
4623 /* It is a conversion operator. See if the type converted to
4624 depends on innermost template operands. */
4626 if (uses_template_parms_level (TREE_TYPE (TREE_TYPE (tmpl)),
4628 DECL_TEMPLATE_CONV_FN_P (tmpl) = 1;
4631 /* Give template template parms a DECL_CONTEXT of the template
4632 for which they are a parameter. */
4633 parms = INNERMOST_TEMPLATE_PARMS (parms);
4634 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
4636 tree parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
4637 if (TREE_CODE (parm) == TEMPLATE_DECL)
4638 DECL_CONTEXT (parm) = tmpl;
4642 /* The DECL_TI_ARGS of DECL contains full set of arguments referring
4643 back to its most general template. If TMPL is a specialization,
4644 ARGS may only have the innermost set of arguments. Add the missing
4645 argument levels if necessary. */
4646 if (DECL_TEMPLATE_INFO (tmpl))
4647 args = add_outermost_template_args (DECL_TI_ARGS (tmpl), args);
4649 info = build_template_info (tmpl, args);
4651 if (DECL_IMPLICIT_TYPEDEF_P (decl))
4652 SET_TYPE_TEMPLATE_INFO (TREE_TYPE (tmpl), info);
4653 else if (DECL_LANG_SPECIFIC (decl))
4654 DECL_TEMPLATE_INFO (decl) = info;
4656 return DECL_TEMPLATE_RESULT (tmpl);
4660 push_template_decl (tree decl)
4662 return push_template_decl_real (decl, false);
4665 /* Called when a class template TYPE is redeclared with the indicated
4666 template PARMS, e.g.:
4668 template <class T> struct S;
4669 template <class T> struct S {}; */
4672 redeclare_class_template (tree type, tree parms)
4678 if (!TYPE_TEMPLATE_INFO (type))
4680 error ("%qT is not a template type", type);
4684 tmpl = TYPE_TI_TEMPLATE (type);
4685 if (!PRIMARY_TEMPLATE_P (tmpl))
4686 /* The type is nested in some template class. Nothing to worry
4687 about here; there are no new template parameters for the nested
4693 error ("template specifiers not specified in declaration of %qD",
4698 parms = INNERMOST_TEMPLATE_PARMS (parms);
4699 tmpl_parms = DECL_INNERMOST_TEMPLATE_PARMS (tmpl);
4701 if (TREE_VEC_LENGTH (parms) != TREE_VEC_LENGTH (tmpl_parms))
4703 error_n (input_location, TREE_VEC_LENGTH (parms),
4704 "redeclared with %d template parameter",
4705 "redeclared with %d template parameters",
4706 TREE_VEC_LENGTH (parms));
4707 inform_n (input_location, TREE_VEC_LENGTH (tmpl_parms),
4708 "previous declaration %q+D used %d template parameter",
4709 "previous declaration %q+D used %d template parameters",
4710 tmpl, TREE_VEC_LENGTH (tmpl_parms));
4714 for (i = 0; i < TREE_VEC_LENGTH (tmpl_parms); ++i)
4721 if (TREE_VEC_ELT (tmpl_parms, i) == error_mark_node
4722 || TREE_VEC_ELT (parms, i) == error_mark_node)
4725 tmpl_parm = TREE_VALUE (TREE_VEC_ELT (tmpl_parms, i));
4726 if (tmpl_parm == error_mark_node)
4729 parm = TREE_VALUE (TREE_VEC_ELT (parms, i));
4730 tmpl_default = TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i));
4731 parm_default = TREE_PURPOSE (TREE_VEC_ELT (parms, i));
4733 /* TMPL_PARM and PARM can be either TYPE_DECL, PARM_DECL, or
4735 if (TREE_CODE (tmpl_parm) != TREE_CODE (parm)
4736 || (TREE_CODE (tmpl_parm) != TYPE_DECL
4737 && !same_type_p (TREE_TYPE (tmpl_parm), TREE_TYPE (parm)))
4738 || (TREE_CODE (tmpl_parm) != PARM_DECL
4739 && (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (tmpl_parm))
4740 != TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm))))
4741 || (TREE_CODE (tmpl_parm) == PARM_DECL
4742 && (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (tmpl_parm))
4743 != TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))))
4745 error ("template parameter %q+#D", tmpl_parm);
4746 error ("redeclared here as %q#D", parm);
4750 if (tmpl_default != NULL_TREE && parm_default != NULL_TREE)
4752 /* We have in [temp.param]:
4754 A template-parameter may not be given default arguments
4755 by two different declarations in the same scope. */
4756 error_at (input_location, "redefinition of default argument for %q#D", parm);
4757 inform (DECL_SOURCE_LOCATION (tmpl_parm),
4758 "original definition appeared here");
4762 if (parm_default != NULL_TREE)
4763 /* Update the previous template parameters (which are the ones
4764 that will really count) with the new default value. */
4765 TREE_PURPOSE (TREE_VEC_ELT (tmpl_parms, i)) = parm_default;
4766 else if (tmpl_default != NULL_TREE)
4767 /* Update the new parameters, too; they'll be used as the
4768 parameters for any members. */
4769 TREE_PURPOSE (TREE_VEC_ELT (parms, i)) = tmpl_default;
4775 /* Simplify EXPR if it is a non-dependent expression. Returns the
4776 (possibly simplified) expression. */
4779 fold_non_dependent_expr (tree expr)
4781 if (expr == NULL_TREE)
4784 /* If we're in a template, but EXPR isn't value dependent, simplify
4785 it. We're supposed to treat:
4787 template <typename T> void f(T[1 + 1]);
4788 template <typename T> void f(T[2]);
4790 as two declarations of the same function, for example. */
4791 if (processing_template_decl
4792 && !type_dependent_expression_p (expr)
4793 && !value_dependent_expression_p (expr))
4795 HOST_WIDE_INT saved_processing_template_decl;
4797 saved_processing_template_decl = processing_template_decl;
4798 processing_template_decl = 0;
4799 expr = tsubst_copy_and_build (expr,
4802 /*in_decl=*/NULL_TREE,
4803 /*function_p=*/false,
4804 /*integral_constant_expression_p=*/true);
4805 processing_template_decl = saved_processing_template_decl;
4810 /* EXPR is an expression which is used in a constant-expression context.
4811 For instance, it could be a VAR_DECL with a constant initializer.
4812 Extract the innermost constant expression.
4814 This is basically a more powerful version of
4815 integral_constant_value, which can be used also in templates where
4816 initializers can maintain a syntactic rather than semantic form
4817 (even if they are non-dependent, for access-checking purposes). */
4820 fold_decl_constant_value (tree expr)
4822 tree const_expr = expr;
4825 expr = fold_non_dependent_expr (const_expr);
4826 const_expr = integral_constant_value (expr);
4828 while (expr != const_expr);
4833 /* Subroutine of convert_nontype_argument. Converts EXPR to TYPE, which
4834 must be a function or a pointer-to-function type, as specified
4835 in [temp.arg.nontype]: disambiguate EXPR if it is an overload set,
4836 and check that the resulting function has external linkage. */
4839 convert_nontype_argument_function (tree type, tree expr)
4844 fn = instantiate_type (type, fns, tf_none);
4845 if (fn == error_mark_node)
4846 return error_mark_node;
4849 if (TREE_CODE (fn_no_ptr) == ADDR_EXPR)
4850 fn_no_ptr = TREE_OPERAND (fn_no_ptr, 0);
4851 if (TREE_CODE (fn_no_ptr) == BASELINK)
4852 fn_no_ptr = BASELINK_FUNCTIONS (fn_no_ptr);
4854 /* [temp.arg.nontype]/1
4856 A template-argument for a non-type, non-template template-parameter
4859 -- the address of an object or function with external linkage. */
4860 if (!DECL_EXTERNAL_LINKAGE_P (fn_no_ptr))
4862 error ("%qE is not a valid template argument for type %qT "
4863 "because function %qD has not external linkage",
4864 expr, type, fn_no_ptr);
4871 /* Subroutine of convert_nontype_argument.
4872 Check if EXPR of type TYPE is a valid pointer-to-member constant.
4873 Emit an error otherwise. */
4876 check_valid_ptrmem_cst_expr (tree type, tree expr)
4879 if (expr && (null_ptr_cst_p (expr) || TREE_CODE (expr) == PTRMEM_CST))
4881 error ("%qE is not a valid template argument for type %qT",
4883 error ("it must be a pointer-to-member of the form `&X::Y'");
4887 /* Attempt to convert the non-type template parameter EXPR to the
4888 indicated TYPE. If the conversion is successful, return the
4889 converted value. If the conversion is unsuccessful, return
4890 NULL_TREE if we issued an error message, or error_mark_node if we
4891 did not. We issue error messages for out-and-out bad template
4892 parameters, but not simply because the conversion failed, since we
4893 might be just trying to do argument deduction. Both TYPE and EXPR
4894 must be non-dependent.
4896 The conversion follows the special rules described in
4897 [temp.arg.nontype], and it is much more strict than an implicit
4900 This function is called twice for each template argument (see
4901 lookup_template_class for a more accurate description of this
4902 problem). This means that we need to handle expressions which
4903 are not valid in a C++ source, but can be created from the
4904 first call (for instance, casts to perform conversions). These
4905 hacks can go away after we fix the double coercion problem. */
4908 convert_nontype_argument (tree type, tree expr)
4912 /* Detect immediately string literals as invalid non-type argument.
4913 This special-case is not needed for correctness (we would easily
4914 catch this later), but only to provide better diagnostic for this
4915 common user mistake. As suggested by DR 100, we do not mention
4916 linkage issues in the diagnostic as this is not the point. */
4917 if (TREE_CODE (expr) == STRING_CST)
4919 error ("%qE is not a valid template argument for type %qT "
4920 "because string literals can never be used in this context",
4925 /* If we are in a template, EXPR may be non-dependent, but still
4926 have a syntactic, rather than semantic, form. For example, EXPR
4927 might be a SCOPE_REF, rather than the VAR_DECL to which the
4928 SCOPE_REF refers. Preserving the qualifying scope is necessary
4929 so that access checking can be performed when the template is
4930 instantiated -- but here we need the resolved form so that we can
4931 convert the argument. */
4932 expr = fold_non_dependent_expr (expr);
4933 if (error_operand_p (expr))
4934 return error_mark_node;
4935 expr_type = TREE_TYPE (expr);
4936 expr = mark_rvalue_use (expr);
4938 /* HACK: Due to double coercion, we can get a
4939 NOP_EXPR<REFERENCE_TYPE>(ADDR_EXPR<POINTER_TYPE> (arg)) here,
4940 which is the tree that we built on the first call (see
4941 below when coercing to reference to object or to reference to
4942 function). We just strip everything and get to the arg.
4943 See g++.old-deja/g++.oliva/template4.C and g++.dg/template/nontype9.C
4945 if (TREE_CODE (expr) == NOP_EXPR)
4947 if (TYPE_REF_OBJ_P (type) || TYPE_REFFN_P (type))
4949 /* ??? Maybe we could use convert_from_reference here, but we
4950 would need to relax its constraints because the NOP_EXPR
4951 could actually change the type to something more cv-qualified,
4952 and this is not folded by convert_from_reference. */
4953 tree addr = TREE_OPERAND (expr, 0);
4954 gcc_assert (TREE_CODE (expr_type) == REFERENCE_TYPE);
4955 gcc_assert (TREE_CODE (addr) == ADDR_EXPR);
4956 gcc_assert (TREE_CODE (TREE_TYPE (addr)) == POINTER_TYPE);
4957 gcc_assert (same_type_ignoring_top_level_qualifiers_p
4958 (TREE_TYPE (expr_type),
4959 TREE_TYPE (TREE_TYPE (addr))));
4961 expr = TREE_OPERAND (addr, 0);
4962 expr_type = TREE_TYPE (expr);
4965 /* We could also generate a NOP_EXPR(ADDR_EXPR()) when the
4966 parameter is a pointer to object, through decay and
4967 qualification conversion. Let's strip everything. */
4968 else if (TYPE_PTROBV_P (type))
4971 gcc_assert (TREE_CODE (expr) == ADDR_EXPR);
4972 gcc_assert (TREE_CODE (TREE_TYPE (expr)) == POINTER_TYPE);
4973 /* Skip the ADDR_EXPR only if it is part of the decay for
4974 an array. Otherwise, it is part of the original argument
4975 in the source code. */
4976 if (TREE_CODE (TREE_TYPE (TREE_OPERAND (expr, 0))) == ARRAY_TYPE)
4977 expr = TREE_OPERAND (expr, 0);
4978 expr_type = TREE_TYPE (expr);
4982 /* [temp.arg.nontype]/5, bullet 1
4984 For a non-type template-parameter of integral or enumeration type,
4985 integral promotions (_conv.prom_) and integral conversions
4986 (_conv.integral_) are applied. */
4987 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
4989 if (!INTEGRAL_OR_ENUMERATION_TYPE_P (expr_type))
4990 return error_mark_node;
4992 expr = fold_decl_constant_value (expr);
4993 /* Notice that there are constant expressions like '4 % 0' which
4994 do not fold into integer constants. */
4995 if (TREE_CODE (expr) != INTEGER_CST)
4997 error ("%qE is not a valid template argument for type %qT "
4998 "because it is a non-constant expression", expr, type);
5002 /* At this point, an implicit conversion does what we want,
5003 because we already know that the expression is of integral
5005 expr = ocp_convert (type, expr, CONV_IMPLICIT, LOOKUP_PROTECT);
5006 if (expr == error_mark_node)
5007 return error_mark_node;
5009 /* Conversion was allowed: fold it to a bare integer constant. */
5012 /* [temp.arg.nontype]/5, bullet 2
5014 For a non-type template-parameter of type pointer to object,
5015 qualification conversions (_conv.qual_) and the array-to-pointer
5016 conversion (_conv.array_) are applied. */
5017 else if (TYPE_PTROBV_P (type))
5019 /* [temp.arg.nontype]/1 (TC1 version, DR 49):
5021 A template-argument for a non-type, non-template template-parameter
5022 shall be one of: [...]
5024 -- the name of a non-type template-parameter;
5025 -- the address of an object or function with external linkage, [...]
5026 expressed as "& id-expression" where the & is optional if the name
5027 refers to a function or array, or if the corresponding
5028 template-parameter is a reference.
5030 Here, we do not care about functions, as they are invalid anyway
5031 for a parameter of type pointer-to-object. */
5033 if (DECL_P (expr) && DECL_TEMPLATE_PARM_P (expr))
5034 /* Non-type template parameters are OK. */
5036 else if (TREE_CODE (expr) != ADDR_EXPR
5037 && TREE_CODE (expr_type) != ARRAY_TYPE)
5039 if (TREE_CODE (expr) == VAR_DECL)
5041 error ("%qD is not a valid template argument "
5042 "because %qD is a variable, not the address of "
5047 /* Other values, like integer constants, might be valid
5048 non-type arguments of some other type. */
5049 return error_mark_node;
5055 decl = ((TREE_CODE (expr) == ADDR_EXPR)
5056 ? TREE_OPERAND (expr, 0) : expr);
5057 if (TREE_CODE (decl) != VAR_DECL)
5059 error ("%qE is not a valid template argument of type %qT "
5060 "because %qE is not a variable",
5064 else if (!DECL_EXTERNAL_LINKAGE_P (decl))
5066 error ("%qE is not a valid template argument of type %qT "
5067 "because %qD does not have external linkage",
5073 expr = decay_conversion (expr);
5074 if (expr == error_mark_node)
5075 return error_mark_node;
5077 expr = perform_qualification_conversions (type, expr);
5078 if (expr == error_mark_node)
5079 return error_mark_node;
5081 /* [temp.arg.nontype]/5, bullet 3
5083 For a non-type template-parameter of type reference to object, no
5084 conversions apply. The type referred to by the reference may be more
5085 cv-qualified than the (otherwise identical) type of the
5086 template-argument. The template-parameter is bound directly to the
5087 template-argument, which must be an lvalue. */
5088 else if (TYPE_REF_OBJ_P (type))
5090 if (!same_type_ignoring_top_level_qualifiers_p (TREE_TYPE (type),
5092 return error_mark_node;
5094 if (!at_least_as_qualified_p (TREE_TYPE (type), expr_type))
5096 error ("%qE is not a valid template argument for type %qT "
5097 "because of conflicts in cv-qualification", expr, type);
5101 if (!real_lvalue_p (expr))
5103 error ("%qE is not a valid template argument for type %qT "
5104 "because it is not an lvalue", expr, type);
5108 /* [temp.arg.nontype]/1
5110 A template-argument for a non-type, non-template template-parameter
5111 shall be one of: [...]
5113 -- the address of an object or function with external linkage. */
5114 if (TREE_CODE (expr) == INDIRECT_REF
5115 && TYPE_REF_OBJ_P (TREE_TYPE (TREE_OPERAND (expr, 0))))
5117 expr = TREE_OPERAND (expr, 0);
5120 error ("%q#D is not a valid template argument for type %qT "
5121 "because a reference variable does not have a constant "
5122 "address", expr, type);
5129 error ("%qE is not a valid template argument for type %qT "
5130 "because it is not an object with external linkage",
5135 if (!DECL_EXTERNAL_LINKAGE_P (expr))
5137 error ("%qE is not a valid template argument for type %qT "
5138 "because object %qD has not external linkage",
5143 expr = build_nop (type, build_address (expr));
5145 /* [temp.arg.nontype]/5, bullet 4
5147 For a non-type template-parameter of type pointer to function, only
5148 the function-to-pointer conversion (_conv.func_) is applied. If the
5149 template-argument represents a set of overloaded functions (or a
5150 pointer to such), the matching function is selected from the set
5152 else if (TYPE_PTRFN_P (type))
5154 /* If the argument is a template-id, we might not have enough
5155 context information to decay the pointer. */
5156 if (!type_unknown_p (expr_type))
5158 expr = decay_conversion (expr);
5159 if (expr == error_mark_node)
5160 return error_mark_node;
5163 expr = convert_nontype_argument_function (type, expr);
5164 if (!expr || expr == error_mark_node)
5167 if (TREE_CODE (expr) != ADDR_EXPR)
5169 error ("%qE is not a valid template argument for type %qT", expr, type);
5170 error ("it must be the address of a function with external linkage");
5174 /* [temp.arg.nontype]/5, bullet 5
5176 For a non-type template-parameter of type reference to function, no
5177 conversions apply. If the template-argument represents a set of
5178 overloaded functions, the matching function is selected from the set
5180 else if (TYPE_REFFN_P (type))
5182 if (TREE_CODE (expr) == ADDR_EXPR)
5184 error ("%qE is not a valid template argument for type %qT "
5185 "because it is a pointer", expr, type);
5186 inform (input_location, "try using %qE instead", TREE_OPERAND (expr, 0));
5190 expr = convert_nontype_argument_function (TREE_TYPE (type), expr);
5191 if (!expr || expr == error_mark_node)
5194 expr = build_nop (type, build_address (expr));
5196 /* [temp.arg.nontype]/5, bullet 6
5198 For a non-type template-parameter of type pointer to member function,
5199 no conversions apply. If the template-argument represents a set of
5200 overloaded member functions, the matching member function is selected
5201 from the set (_over.over_). */
5202 else if (TYPE_PTRMEMFUNC_P (type))
5204 expr = instantiate_type (type, expr, tf_none);
5205 if (expr == error_mark_node)
5206 return error_mark_node;
5208 /* [temp.arg.nontype] bullet 1 says the pointer to member
5209 expression must be a pointer-to-member constant. */
5210 if (!check_valid_ptrmem_cst_expr (type, expr))
5211 return error_mark_node;
5213 /* There is no way to disable standard conversions in
5214 resolve_address_of_overloaded_function (called by
5215 instantiate_type). It is possible that the call succeeded by
5216 converting &B::I to &D::I (where B is a base of D), so we need
5217 to reject this conversion here.
5219 Actually, even if there was a way to disable standard conversions,
5220 it would still be better to reject them here so that we can
5221 provide a superior diagnostic. */
5222 if (!same_type_p (TREE_TYPE (expr), type))
5224 error ("%qE is not a valid template argument for type %qT "
5225 "because it is of type %qT", expr, type,
5227 /* If we are just one standard conversion off, explain. */
5228 if (can_convert (type, TREE_TYPE (expr)))
5229 inform (input_location,
5230 "standard conversions are not allowed in this context");
5234 /* [temp.arg.nontype]/5, bullet 7
5236 For a non-type template-parameter of type pointer to data member,
5237 qualification conversions (_conv.qual_) are applied. */
5238 else if (TYPE_PTRMEM_P (type))
5240 /* [temp.arg.nontype] bullet 1 says the pointer to member
5241 expression must be a pointer-to-member constant. */
5242 if (!check_valid_ptrmem_cst_expr (type, expr))
5243 return error_mark_node;
5245 expr = perform_qualification_conversions (type, expr);
5246 if (expr == error_mark_node)
5249 /* A template non-type parameter must be one of the above. */
5253 /* Sanity check: did we actually convert the argument to the
5255 gcc_assert (same_type_p (type, TREE_TYPE (expr)));
5259 /* Subroutine of coerce_template_template_parms, which returns 1 if
5260 PARM_PARM and ARG_PARM match using the rule for the template
5261 parameters of template template parameters. Both PARM and ARG are
5262 template parameters; the rest of the arguments are the same as for
5263 coerce_template_template_parms.
5266 coerce_template_template_parm (tree parm,
5268 tsubst_flags_t complain,
5272 if (arg == NULL_TREE || arg == error_mark_node
5273 || parm == NULL_TREE || parm == error_mark_node)
5276 if (TREE_CODE (arg) != TREE_CODE (parm))
5279 switch (TREE_CODE (parm))
5282 /* We encounter instantiations of templates like
5283 template <template <template <class> class> class TT>
5286 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
5287 tree argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
5289 if (!coerce_template_template_parms
5290 (parmparm, argparm, complain, in_decl, outer_args))
5296 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (arg))
5297 && !TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
5298 /* Argument is a parameter pack but parameter is not. */
5303 /* The tsubst call is used to handle cases such as
5305 template <int> class C {};
5306 template <class T, template <T> class TT> class D {};
5309 i.e. the parameter list of TT depends on earlier parameters. */
5310 if (!uses_template_parms (TREE_TYPE (arg))
5312 (tsubst (TREE_TYPE (parm), outer_args, complain, in_decl),
5316 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (arg))
5317 && !TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
5318 /* Argument is a parameter pack but parameter is not. */
5331 /* Return 1 if PARM_PARMS and ARG_PARMS matches using rule for
5332 template template parameters. Both PARM_PARMS and ARG_PARMS are
5333 vectors of TREE_LIST nodes containing TYPE_DECL, TEMPLATE_DECL
5336 Consider the example:
5337 template <class T> class A;
5338 template<template <class U> class TT> class B;
5340 For B<A>, PARM_PARMS are the parameters to TT, while ARG_PARMS are
5341 the parameters to A, and OUTER_ARGS contains A. */
5344 coerce_template_template_parms (tree parm_parms,
5346 tsubst_flags_t complain,
5350 int nparms, nargs, i;
5354 gcc_assert (TREE_CODE (parm_parms) == TREE_VEC);
5355 gcc_assert (TREE_CODE (arg_parms) == TREE_VEC);
5357 nparms = TREE_VEC_LENGTH (parm_parms);
5358 nargs = TREE_VEC_LENGTH (arg_parms);
5360 /* Determine whether we have a parameter pack at the end of the
5361 template template parameter's template parameter list. */
5362 if (TREE_VEC_ELT (parm_parms, nparms - 1) != error_mark_node)
5364 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, nparms - 1));
5366 if (parm == error_mark_node)
5369 switch (TREE_CODE (parm))
5373 if (TEMPLATE_TYPE_PARAMETER_PACK (TREE_TYPE (parm)))
5378 if (TEMPLATE_PARM_PARAMETER_PACK (DECL_INITIAL (parm)))
5388 && !(variadic_p && nargs >= nparms - 1))
5391 /* Check all of the template parameters except the parameter pack at
5392 the end (if any). */
5393 for (i = 0; i < nparms - variadic_p; ++i)
5395 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node
5396 || TREE_VEC_ELT (arg_parms, i) == error_mark_node)
5399 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
5400 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
5402 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
5410 /* Check each of the template parameters in the template
5411 argument against the template parameter pack at the end of
5412 the template template parameter. */
5413 if (TREE_VEC_ELT (parm_parms, i) == error_mark_node)
5416 parm = TREE_VALUE (TREE_VEC_ELT (parm_parms, i));
5418 for (; i < nargs; ++i)
5420 if (TREE_VEC_ELT (arg_parms, i) == error_mark_node)
5423 arg = TREE_VALUE (TREE_VEC_ELT (arg_parms, i));
5425 if (!coerce_template_template_parm (parm, arg, complain, in_decl,
5434 /* Verifies that the deduced template arguments (in TARGS) for the
5435 template template parameters (in TPARMS) represent valid bindings,
5436 by comparing the template parameter list of each template argument
5437 to the template parameter list of its corresponding template
5438 template parameter, in accordance with DR150. This
5439 routine can only be called after all template arguments have been
5440 deduced. It will return TRUE if all of the template template
5441 parameter bindings are okay, FALSE otherwise. */
5443 template_template_parm_bindings_ok_p (tree tparms, tree targs)
5445 int i, ntparms = TREE_VEC_LENGTH (tparms);
5448 /* We're dealing with template parms in this process. */
5449 ++processing_template_decl;
5451 targs = INNERMOST_TEMPLATE_ARGS (targs);
5453 for (i = 0; i < ntparms; ++i)
5455 tree tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
5456 tree targ = TREE_VEC_ELT (targs, i);
5458 if (TREE_CODE (tparm) == TEMPLATE_DECL && targ)
5460 tree packed_args = NULL_TREE;
5463 if (ARGUMENT_PACK_P (targ))
5465 /* Look inside the argument pack. */
5466 packed_args = ARGUMENT_PACK_ARGS (targ);
5467 len = TREE_VEC_LENGTH (packed_args);
5470 for (idx = 0; idx < len; ++idx)
5472 tree targ_parms = NULL_TREE;
5475 /* Extract the next argument from the argument
5477 targ = TREE_VEC_ELT (packed_args, idx);
5479 if (PACK_EXPANSION_P (targ))
5480 /* Look at the pattern of the pack expansion. */
5481 targ = PACK_EXPANSION_PATTERN (targ);
5483 /* Extract the template parameters from the template
5485 if (TREE_CODE (targ) == TEMPLATE_DECL)
5486 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (targ);
5487 else if (TREE_CODE (targ) == TEMPLATE_TEMPLATE_PARM)
5488 targ_parms = DECL_INNERMOST_TEMPLATE_PARMS (TYPE_NAME (targ));
5490 /* Verify that we can coerce the template template
5491 parameters from the template argument to the template
5492 parameter. This requires an exact match. */
5494 && !coerce_template_template_parms
5495 (DECL_INNERMOST_TEMPLATE_PARMS (tparm),
5510 --processing_template_decl;
5514 /* Convert the indicated template ARG as necessary to match the
5515 indicated template PARM. Returns the converted ARG, or
5516 error_mark_node if the conversion was unsuccessful. Error and
5517 warning messages are issued under control of COMPLAIN. This
5518 conversion is for the Ith parameter in the parameter list. ARGS is
5519 the full set of template arguments deduced so far. */
5522 convert_template_argument (tree parm,
5525 tsubst_flags_t complain,
5531 int is_type, requires_type, is_tmpl_type, requires_tmpl_type;
5533 if (TREE_CODE (arg) == TREE_LIST
5534 && TREE_CODE (TREE_VALUE (arg)) == OFFSET_REF)
5536 /* The template argument was the name of some
5537 member function. That's usually
5538 invalid, but static members are OK. In any
5539 case, grab the underlying fields/functions
5540 and issue an error later if required. */
5541 orig_arg = TREE_VALUE (arg);
5542 TREE_TYPE (arg) = unknown_type_node;
5547 requires_tmpl_type = TREE_CODE (parm) == TEMPLATE_DECL;
5548 requires_type = (TREE_CODE (parm) == TYPE_DECL
5549 || requires_tmpl_type);
5551 /* When determining whether an argument pack expansion is a template,
5552 look at the pattern. */
5553 if (TREE_CODE (arg) == TYPE_PACK_EXPANSION)
5554 arg = PACK_EXPANSION_PATTERN (arg);
5556 /* Deal with an injected-class-name used as a template template arg. */
5557 if (requires_tmpl_type && CLASS_TYPE_P (arg))
5559 tree t = maybe_get_template_decl_from_type_decl (TYPE_NAME (arg));
5560 if (TREE_CODE (t) == TEMPLATE_DECL)
5562 if (complain & tf_warning_or_error)
5563 pedwarn (input_location, OPT_pedantic, "injected-class-name %qD"
5564 " used as template template argument", TYPE_NAME (arg));
5565 else if (flag_pedantic_errors)
5573 ((TREE_CODE (arg) == TEMPLATE_DECL
5574 && TREE_CODE (DECL_TEMPLATE_RESULT (arg)) == TYPE_DECL)
5575 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
5576 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE);
5579 && (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM
5580 || TREE_CODE (arg) == UNBOUND_CLASS_TEMPLATE))
5581 arg = TYPE_STUB_DECL (arg);
5583 is_type = TYPE_P (arg) || is_tmpl_type;
5585 if (requires_type && ! is_type && TREE_CODE (arg) == SCOPE_REF
5586 && TREE_CODE (TREE_OPERAND (arg, 0)) == TEMPLATE_TYPE_PARM)
5588 permerror (input_location, "to refer to a type member of a template parameter, "
5589 "use %<typename %E%>", orig_arg);
5591 orig_arg = make_typename_type (TREE_OPERAND (arg, 0),
5592 TREE_OPERAND (arg, 1),
5594 complain & tf_error);
5598 if (is_type != requires_type)
5602 if (complain & tf_error)
5604 error ("type/value mismatch at argument %d in template "
5605 "parameter list for %qD",
5608 error (" expected a constant of type %qT, got %qT",
5610 (DECL_P (arg) ? DECL_NAME (arg) : orig_arg));
5611 else if (requires_tmpl_type)
5612 error (" expected a class template, got %qE", orig_arg);
5614 error (" expected a type, got %qE", orig_arg);
5617 return error_mark_node;
5619 if (is_tmpl_type ^ requires_tmpl_type)
5621 if (in_decl && (complain & tf_error))
5623 error ("type/value mismatch at argument %d in template "
5624 "parameter list for %qD",
5627 error (" expected a type, got %qT", DECL_NAME (arg));
5629 error (" expected a class template, got %qT", orig_arg);
5631 return error_mark_node;
5636 if (requires_tmpl_type)
5638 if (TREE_CODE (TREE_TYPE (arg)) == UNBOUND_CLASS_TEMPLATE)
5639 /* The number of argument required is not known yet.
5640 Just accept it for now. */
5641 val = TREE_TYPE (arg);
5644 tree parmparm = DECL_INNERMOST_TEMPLATE_PARMS (parm);
5647 argparm = DECL_INNERMOST_TEMPLATE_PARMS (arg);
5649 if (coerce_template_template_parms (parmparm, argparm,
5655 /* TEMPLATE_TEMPLATE_PARM node is preferred over
5657 if (val != error_mark_node)
5659 if (DECL_TEMPLATE_TEMPLATE_PARM_P (val))
5660 val = TREE_TYPE (val);
5661 if (TREE_CODE (orig_arg) == TYPE_PACK_EXPANSION)
5662 val = make_pack_expansion (val);
5667 if (in_decl && (complain & tf_error))
5669 error ("type/value mismatch at argument %d in "
5670 "template parameter list for %qD",
5672 error (" expected a template of type %qD, got %qT",
5676 val = error_mark_node;
5682 /* We only form one instance of each template specialization.
5683 Therefore, if we use a non-canonical variant (i.e., a
5684 typedef), any future messages referring to the type will use
5685 the typedef, which is confusing if those future uses do not
5686 themselves also use the typedef. */
5688 val = strip_typedefs (val);
5692 tree t = tsubst (TREE_TYPE (parm), args, complain, in_decl);
5694 if (invalid_nontype_parm_type_p (t, complain))
5695 return error_mark_node;
5697 if (template_parameter_pack_p (parm) && ARGUMENT_PACK_P (orig_arg))
5699 if (same_type_p (t, TREE_TYPE (orig_arg)))
5703 /* Not sure if this is reachable, but it doesn't hurt
5705 error ("type mismatch in nontype parameter pack");
5706 val = error_mark_node;
5709 else if (!uses_template_parms (orig_arg) && !uses_template_parms (t))
5710 /* We used to call digest_init here. However, digest_init
5711 will report errors, which we don't want when complain
5712 is zero. More importantly, digest_init will try too
5713 hard to convert things: for example, `0' should not be
5714 converted to pointer type at this point according to
5715 the standard. Accepting this is not merely an
5716 extension, since deciding whether or not these
5717 conversions can occur is part of determining which
5718 function template to call, or whether a given explicit
5719 argument specification is valid. */
5720 val = convert_nontype_argument (t, orig_arg);
5724 if (val == NULL_TREE)
5725 val = error_mark_node;
5726 else if (val == error_mark_node && (complain & tf_error))
5727 error ("could not convert template argument %qE to %qT", orig_arg, t);
5729 if (TREE_CODE (val) == SCOPE_REF)
5731 /* Strip typedefs from the SCOPE_REF. */
5732 tree type = strip_typedefs (TREE_TYPE (val));
5733 tree scope = strip_typedefs (TREE_OPERAND (val, 0));
5734 val = build_qualified_name (type, scope, TREE_OPERAND (val, 1),
5735 QUALIFIED_NAME_IS_TEMPLATE (val));
5742 /* Coerces the remaining template arguments in INNER_ARGS (from
5743 ARG_IDX to the end) into the parameter pack at PARM_IDX in PARMS.
5744 Returns the coerced argument pack. PARM_IDX is the position of this
5745 parameter in the template parameter list. ARGS is the original
5746 template argument list. */
5748 coerce_template_parameter_pack (tree parms,
5756 tsubst_flags_t complain)
5758 tree parm = TREE_VEC_ELT (parms, parm_idx);
5759 int nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
5762 tree packed_types = NULL_TREE;
5764 if (arg_idx > nargs)
5767 packed_args = make_tree_vec (nargs - arg_idx);
5769 if (TREE_CODE (TREE_VALUE (parm)) == PARM_DECL
5770 && uses_parameter_packs (TREE_TYPE (TREE_VALUE (parm))))
5772 /* When the template parameter is a non-type template
5773 parameter pack whose type uses parameter packs, we need
5774 to look at each of the template arguments
5775 separately. Build a vector of the types for these
5776 non-type template parameters in PACKED_TYPES. */
5778 = make_pack_expansion (TREE_TYPE (TREE_VALUE (parm)));
5779 packed_types = tsubst_pack_expansion (expansion, args,
5782 if (packed_types == error_mark_node)
5783 return error_mark_node;
5785 /* Check that we have the right number of arguments. */
5787 && !PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx))
5788 && nargs - arg_idx != TREE_VEC_LENGTH (packed_types))
5791 = TREE_VEC_LENGTH (parms) - 1 + TREE_VEC_LENGTH (packed_types);
5792 error ("wrong number of template arguments (%d, should be %d)",
5793 nargs, needed_parms);
5794 return error_mark_node;
5797 /* If we aren't able to check the actual arguments now
5798 (because they haven't been expanded yet), we can at least
5799 verify that all of the types used for the non-type
5800 template parameter pack are, in fact, valid for non-type
5801 template parameters. */
5803 && PACK_EXPANSION_P (TREE_VEC_ELT (inner_args, arg_idx)))
5805 int j, len = TREE_VEC_LENGTH (packed_types);
5806 for (j = 0; j < len; ++j)
5808 tree t = TREE_VEC_ELT (packed_types, j);
5809 if (invalid_nontype_parm_type_p (t, complain))
5810 return error_mark_node;
5815 /* Convert the remaining arguments, which will be a part of the
5816 parameter pack "parm". */
5817 for (; arg_idx < nargs; ++arg_idx)
5819 tree arg = TREE_VEC_ELT (inner_args, arg_idx);
5820 tree actual_parm = TREE_VALUE (parm);
5822 if (packed_types && !PACK_EXPANSION_P (arg))
5824 /* When we have a vector of types (corresponding to the
5825 non-type template parameter pack that uses parameter
5826 packs in its type, as mention above), and the
5827 argument is not an expansion (which expands to a
5828 currently unknown number of arguments), clone the
5829 parm and give it the next type in PACKED_TYPES. */
5830 actual_parm = copy_node (actual_parm);
5831 TREE_TYPE (actual_parm) =
5832 TREE_VEC_ELT (packed_types, arg_idx - parm_idx);
5835 if (arg != error_mark_node)
5836 arg = convert_template_argument (actual_parm,
5837 arg, new_args, complain, parm_idx,
5839 if (arg == error_mark_node)
5841 TREE_VEC_ELT (packed_args, arg_idx - parm_idx) = arg;
5844 if (TREE_CODE (TREE_VALUE (parm)) == TYPE_DECL
5845 || TREE_CODE (TREE_VALUE (parm)) == TEMPLATE_DECL)
5846 argument_pack = cxx_make_type (TYPE_ARGUMENT_PACK);
5849 argument_pack = make_node (NONTYPE_ARGUMENT_PACK);
5850 TREE_TYPE (argument_pack)
5851 = tsubst (TREE_TYPE (TREE_VALUE (parm)), new_args, complain, in_decl);
5852 TREE_CONSTANT (argument_pack) = 1;
5855 SET_ARGUMENT_PACK_ARGS (argument_pack, packed_args);
5856 #ifdef ENABLE_CHECKING
5857 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (packed_args,
5858 TREE_VEC_LENGTH (packed_args));
5860 return argument_pack;
5863 /* Convert all template arguments to their appropriate types, and
5864 return a vector containing the innermost resulting template
5865 arguments. If any error occurs, return error_mark_node. Error and
5866 warning messages are issued under control of COMPLAIN.
5868 If REQUIRE_ALL_ARGS is false, argument deduction will be performed
5869 for arguments not specified in ARGS. Otherwise, if
5870 USE_DEFAULT_ARGS is true, default arguments will be used to fill in
5871 unspecified arguments. If REQUIRE_ALL_ARGS is true, but
5872 USE_DEFAULT_ARGS is false, then all arguments must be specified in
5876 coerce_template_parms (tree parms,
5879 tsubst_flags_t complain,
5880 bool require_all_args,
5881 bool use_default_args)
5883 int nparms, nargs, parm_idx, arg_idx, lost = 0;
5886 tree new_inner_args;
5887 int saved_unevaluated_operand;
5888 int saved_inhibit_evaluation_warnings;
5890 /* When used as a boolean value, indicates whether this is a
5891 variadic template parameter list. Since it's an int, we can also
5892 subtract it from nparms to get the number of non-variadic
5896 nparms = TREE_VEC_LENGTH (parms);
5898 /* Determine if there are any parameter packs. */
5899 for (parm_idx = 0; parm_idx < nparms; ++parm_idx)
5901 tree tparm = TREE_VALUE (TREE_VEC_ELT (parms, parm_idx));
5902 if (template_parameter_pack_p (tparm))
5906 inner_args = INNERMOST_TEMPLATE_ARGS (args);
5907 /* If there are 0 or 1 parameter packs, we need to expand any argument
5908 packs so that we can deduce a parameter pack from some non-packed args
5909 followed by an argument pack, as in variadic85.C. If there are more
5910 than that, we need to leave argument packs intact so the arguments are
5911 assigned to the right parameter packs. This should only happen when
5912 dealing with a nested class inside a partial specialization of a class
5913 template, as in variadic92.C. */
5914 if (variadic_p <= 1)
5915 inner_args = expand_template_argument_pack (inner_args);
5917 nargs = inner_args ? NUM_TMPL_ARGS (inner_args) : 0;
5918 if ((nargs > nparms && !variadic_p)
5919 || (nargs < nparms - variadic_p
5921 && (!use_default_args
5922 || (TREE_VEC_ELT (parms, nargs) != error_mark_node
5923 && !TREE_PURPOSE (TREE_VEC_ELT (parms, nargs))))))
5925 if (complain & tf_error)
5927 const char *or_more = "";
5930 or_more = " or more";
5934 error ("wrong number of template arguments (%d, should be %d%s)",
5935 nargs, nparms, or_more);
5938 error ("provided for %q+D", in_decl);
5941 return error_mark_node;
5944 /* We need to evaluate the template arguments, even though this
5945 template-id may be nested within a "sizeof". */
5946 saved_unevaluated_operand = cp_unevaluated_operand;
5947 cp_unevaluated_operand = 0;
5948 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
5949 c_inhibit_evaluation_warnings = 0;
5950 new_inner_args = make_tree_vec (nparms);
5951 new_args = add_outermost_template_args (args, new_inner_args);
5952 for (parm_idx = 0, arg_idx = 0; parm_idx < nparms; parm_idx++, arg_idx++)
5957 /* Get the Ith template parameter. */
5958 parm = TREE_VEC_ELT (parms, parm_idx);
5960 if (parm == error_mark_node)
5962 TREE_VEC_ELT (new_inner_args, arg_idx) = error_mark_node;
5966 /* Calculate the next argument. */
5967 if (arg_idx < nargs)
5968 arg = TREE_VEC_ELT (inner_args, arg_idx);
5972 if (template_parameter_pack_p (TREE_VALUE (parm))
5973 && !(arg && ARGUMENT_PACK_P (arg)))
5975 /* All remaining arguments will be placed in the
5976 template parameter pack PARM. */
5977 arg = coerce_template_parameter_pack (parms, parm_idx, args,
5978 inner_args, arg_idx,
5982 /* Store this argument. */
5983 if (arg == error_mark_node)
5985 TREE_VEC_ELT (new_inner_args, parm_idx) = arg;
5987 /* We are done with all of the arguments. */
5994 if (PACK_EXPANSION_P (arg))
5996 if (complain & tf_error)
5998 /* FIXME this restriction was removed by N2555; see
6000 /* If ARG is a pack expansion, but PARM is not a
6001 template parameter pack (if it were, we would have
6002 handled it above), we're trying to expand into a
6003 fixed-length argument list. */
6004 if (TREE_CODE (arg) == EXPR_PACK_EXPANSION)
6005 sorry ("cannot expand %<%E%> into a fixed-length "
6006 "argument list", arg);
6008 sorry ("cannot expand %<%T%> into a fixed-length "
6009 "argument list", arg);
6011 return error_mark_node;
6014 else if (require_all_args)
6016 /* There must be a default arg in this case. */
6017 arg = tsubst_template_arg (TREE_PURPOSE (parm), new_args,
6019 /* The position of the first default template argument,
6020 is also the number of non-defaulted arguments in NEW_INNER_ARGS.
6022 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args))
6023 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args, arg_idx);
6028 if (arg == error_mark_node)
6030 if (complain & tf_error)
6031 error ("template argument %d is invalid", arg_idx + 1);
6034 /* This only occurs if there was an error in the template
6035 parameter list itself (which we would already have
6036 reported) that we are trying to recover from, e.g., a class
6037 template with a parameter list such as
6038 template<typename..., typename>. */
6039 return error_mark_node;
6041 arg = convert_template_argument (TREE_VALUE (parm),
6042 arg, new_args, complain,
6045 if (arg == error_mark_node)
6047 TREE_VEC_ELT (new_inner_args, arg_idx) = arg;
6049 cp_unevaluated_operand = saved_unevaluated_operand;
6050 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
6053 return error_mark_node;
6055 #ifdef ENABLE_CHECKING
6056 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args))
6057 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (new_inner_args,
6058 TREE_VEC_LENGTH (new_inner_args));
6061 return new_inner_args;
6064 /* Returns 1 if template args OT and NT are equivalent. */
6067 template_args_equal (tree ot, tree nt)
6072 if (TREE_CODE (nt) == TREE_VEC)
6073 /* For member templates */
6074 return TREE_CODE (ot) == TREE_VEC && comp_template_args (ot, nt);
6075 else if (PACK_EXPANSION_P (ot))
6076 return PACK_EXPANSION_P (nt)
6077 && template_args_equal (PACK_EXPANSION_PATTERN (ot),
6078 PACK_EXPANSION_PATTERN (nt));
6079 else if (ARGUMENT_PACK_P (ot))
6084 if (!ARGUMENT_PACK_P (nt))
6087 opack = ARGUMENT_PACK_ARGS (ot);
6088 npack = ARGUMENT_PACK_ARGS (nt);
6089 len = TREE_VEC_LENGTH (opack);
6090 if (TREE_VEC_LENGTH (npack) != len)
6092 for (i = 0; i < len; ++i)
6093 if (!template_args_equal (TREE_VEC_ELT (opack, i),
6094 TREE_VEC_ELT (npack, i)))
6098 else if (ot && TREE_CODE (ot) == ARGUMENT_PACK_SELECT)
6100 /* We get here probably because we are in the middle of substituting
6101 into the pattern of a pack expansion. In that case the
6102 ARGUMENT_PACK_SELECT temporarily replaces the pack argument we are
6103 interested in. So we want to use the initial pack argument for
6105 ot = ARGUMENT_PACK_SELECT_FROM_PACK (ot);
6106 if (nt && TREE_CODE (nt) == ARGUMENT_PACK_SELECT)
6107 nt = ARGUMENT_PACK_SELECT_FROM_PACK (nt);
6108 return template_args_equal (ot, nt);
6110 else if (TYPE_P (nt))
6111 return TYPE_P (ot) && same_type_p (ot, nt);
6112 else if (TREE_CODE (ot) == TREE_VEC || TYPE_P (ot))
6115 return cp_tree_equal (ot, nt);
6118 /* Returns 1 iff the OLDARGS and NEWARGS are in fact identical sets
6119 of template arguments. Returns 0 otherwise. */
6122 comp_template_args (tree oldargs, tree newargs)
6126 if (TREE_VEC_LENGTH (oldargs) != TREE_VEC_LENGTH (newargs))
6129 for (i = 0; i < TREE_VEC_LENGTH (oldargs); ++i)
6131 tree nt = TREE_VEC_ELT (newargs, i);
6132 tree ot = TREE_VEC_ELT (oldargs, i);
6134 if (! template_args_equal (ot, nt))
6141 add_pending_template (tree d)
6143 tree ti = (TYPE_P (d)
6144 ? CLASSTYPE_TEMPLATE_INFO (d)
6145 : DECL_TEMPLATE_INFO (d));
6146 struct pending_template *pt;
6149 if (TI_PENDING_TEMPLATE_FLAG (ti))
6152 /* We are called both from instantiate_decl, where we've already had a
6153 tinst_level pushed, and instantiate_template, where we haven't.
6155 level = !current_tinst_level || current_tinst_level->decl != d;
6158 push_tinst_level (d);
6160 pt = GGC_NEW (struct pending_template);
6162 pt->tinst = current_tinst_level;
6163 if (last_pending_template)
6164 last_pending_template->next = pt;
6166 pending_templates = pt;
6168 last_pending_template = pt;
6170 TI_PENDING_TEMPLATE_FLAG (ti) = 1;
6177 /* Return a TEMPLATE_ID_EXPR corresponding to the indicated FNS and
6178 ARGLIST. Valid choices for FNS are given in the cp-tree.def
6179 documentation for TEMPLATE_ID_EXPR. */
6182 lookup_template_function (tree fns, tree arglist)
6186 if (fns == error_mark_node || arglist == error_mark_node)
6187 return error_mark_node;
6189 gcc_assert (!arglist || TREE_CODE (arglist) == TREE_VEC);
6190 gcc_assert (fns && (is_overloaded_fn (fns)
6191 || TREE_CODE (fns) == IDENTIFIER_NODE));
6193 if (BASELINK_P (fns))
6195 BASELINK_FUNCTIONS (fns) = build2 (TEMPLATE_ID_EXPR,
6197 BASELINK_FUNCTIONS (fns),
6202 type = TREE_TYPE (fns);
6203 if (TREE_CODE (fns) == OVERLOAD || !type)
6204 type = unknown_type_node;
6206 return build2 (TEMPLATE_ID_EXPR, type, fns, arglist);
6209 /* Within the scope of a template class S<T>, the name S gets bound
6210 (in build_self_reference) to a TYPE_DECL for the class, not a
6211 TEMPLATE_DECL. If DECL is a TYPE_DECL for current_class_type,
6212 or one of its enclosing classes, and that type is a template,
6213 return the associated TEMPLATE_DECL. Otherwise, the original
6216 Also handle the case when DECL is a TREE_LIST of ambiguous
6217 injected-class-names from different bases. */
6220 maybe_get_template_decl_from_type_decl (tree decl)
6222 if (decl == NULL_TREE)
6225 /* DR 176: A lookup that finds an injected-class-name (10.2
6226 [class.member.lookup]) can result in an ambiguity in certain cases
6227 (for example, if it is found in more than one base class). If all of
6228 the injected-class-names that are found refer to specializations of
6229 the same class template, and if the name is followed by a
6230 template-argument-list, the reference refers to the class template
6231 itself and not a specialization thereof, and is not ambiguous. */
6232 if (TREE_CODE (decl) == TREE_LIST)
6234 tree t, tmpl = NULL_TREE;
6235 for (t = decl; t; t = TREE_CHAIN (t))
6237 tree elt = maybe_get_template_decl_from_type_decl (TREE_VALUE (t));
6240 else if (tmpl != elt)
6243 if (tmpl && t == NULL_TREE)
6249 return (decl != NULL_TREE
6250 && DECL_SELF_REFERENCE_P (decl)
6251 && CLASSTYPE_TEMPLATE_INFO (TREE_TYPE (decl)))
6252 ? CLASSTYPE_TI_TEMPLATE (TREE_TYPE (decl)) : decl;
6255 /* Given an IDENTIFIER_NODE (type TEMPLATE_DECL) and a chain of
6256 parameters, find the desired type.
6258 D1 is the PTYPENAME terminal, and ARGLIST is the list of arguments.
6260 IN_DECL, if non-NULL, is the template declaration we are trying to
6263 If ENTERING_SCOPE is nonzero, we are about to enter the scope of
6264 the class we are looking up.
6266 Issue error and warning messages under control of COMPLAIN.
6268 If the template class is really a local class in a template
6269 function, then the FUNCTION_CONTEXT is the function in which it is
6272 ??? Note that this function is currently called *twice* for each
6273 template-id: the first time from the parser, while creating the
6274 incomplete type (finish_template_type), and the second type during the
6275 real instantiation (instantiate_template_class). This is surely something
6276 that we want to avoid. It also causes some problems with argument
6277 coercion (see convert_nontype_argument for more information on this). */
6280 lookup_template_class (tree d1,
6285 tsubst_flags_t complain)
6287 tree templ = NULL_TREE, parmlist;
6294 timevar_push (TV_NAME_LOOKUP);
6296 if (TREE_CODE (d1) == IDENTIFIER_NODE)
6298 tree value = innermost_non_namespace_value (d1);
6299 if (value && DECL_TEMPLATE_TEMPLATE_PARM_P (value))
6304 push_decl_namespace (context);
6305 templ = lookup_name (d1);
6306 templ = maybe_get_template_decl_from_type_decl (templ);
6308 pop_decl_namespace ();
6311 context = DECL_CONTEXT (templ);
6313 else if (TREE_CODE (d1) == TYPE_DECL && MAYBE_CLASS_TYPE_P (TREE_TYPE (d1)))
6315 tree type = TREE_TYPE (d1);
6317 /* If we are declaring a constructor, say A<T>::A<T>, we will get
6318 an implicit typename for the second A. Deal with it. */
6319 if (TREE_CODE (type) == TYPENAME_TYPE && TREE_TYPE (type))
6320 type = TREE_TYPE (type);
6322 if (CLASSTYPE_TEMPLATE_INFO (type))
6324 templ = CLASSTYPE_TI_TEMPLATE (type);
6325 d1 = DECL_NAME (templ);
6328 else if (TREE_CODE (d1) == ENUMERAL_TYPE
6329 || (TYPE_P (d1) && MAYBE_CLASS_TYPE_P (d1)))
6331 templ = TYPE_TI_TEMPLATE (d1);
6332 d1 = DECL_NAME (templ);
6334 else if (TREE_CODE (d1) == TEMPLATE_DECL
6335 && DECL_TEMPLATE_RESULT (d1)
6336 && TREE_CODE (DECL_TEMPLATE_RESULT (d1)) == TYPE_DECL)
6339 d1 = DECL_NAME (templ);
6340 context = DECL_CONTEXT (templ);
6343 /* Issue an error message if we didn't find a template. */
6346 if (complain & tf_error)
6347 error ("%qT is not a template", d1);
6348 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6351 if (TREE_CODE (templ) != TEMPLATE_DECL
6352 /* Make sure it's a user visible template, if it was named by
6354 || ((complain & tf_user) && !DECL_TEMPLATE_PARM_P (templ)
6355 && !PRIMARY_TEMPLATE_P (templ)))
6357 if (complain & tf_error)
6359 error ("non-template type %qT used as a template", d1);
6361 error ("for template declaration %q+D", in_decl);
6363 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6366 complain &= ~tf_user;
6368 if (DECL_TEMPLATE_TEMPLATE_PARM_P (templ))
6370 /* Create a new TEMPLATE_DECL and TEMPLATE_TEMPLATE_PARM node to store
6371 template arguments */
6377 parmlist = DECL_INNERMOST_TEMPLATE_PARMS (templ);
6379 /* Consider an example where a template template parameter declared as
6381 template <class T, class U = std::allocator<T> > class TT
6383 The template parameter level of T and U are one level larger than
6384 of TT. To proper process the default argument of U, say when an
6385 instantiation `TT<int>' is seen, we need to build the full
6386 arguments containing {int} as the innermost level. Outer levels,
6387 available when not appearing as default template argument, can be
6388 obtained from the arguments of the enclosing template.
6390 Suppose that TT is later substituted with std::vector. The above
6391 instantiation is `TT<int, std::allocator<T> >' with TT at
6392 level 1, and T at level 2, while the template arguments at level 1
6393 becomes {std::vector} and the inner level 2 is {int}. */
6395 outer = DECL_CONTEXT (templ);
6397 outer = TI_ARGS (get_template_info (DECL_TEMPLATE_RESULT (outer)));
6398 else if (current_template_parms)
6399 /* This is an argument of the current template, so we haven't set
6400 DECL_CONTEXT yet. */
6401 outer = current_template_args ();
6404 arglist = add_to_template_args (outer, arglist);
6406 arglist2 = coerce_template_parms (parmlist, arglist, templ,
6408 /*require_all_args=*/true,
6409 /*use_default_args=*/true);
6410 if (arglist2 == error_mark_node
6411 || (!uses_template_parms (arglist2)
6412 && check_instantiated_args (templ, arglist2, complain)))
6413 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6415 parm = bind_template_template_parm (TREE_TYPE (templ), arglist2);
6416 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, parm);
6420 tree template_type = TREE_TYPE (templ);
6423 tree found = NULL_TREE;
6426 int is_dependent_type;
6427 int use_partial_inst_tmpl = false;
6429 gen_tmpl = most_general_template (templ);
6430 parmlist = DECL_TEMPLATE_PARMS (gen_tmpl);
6431 parm_depth = TMPL_PARMS_DEPTH (parmlist);
6432 arg_depth = TMPL_ARGS_DEPTH (arglist);
6434 if (arg_depth == 1 && parm_depth > 1)
6436 /* We've been given an incomplete set of template arguments.
6439 template <class T> struct S1 {
6440 template <class U> struct S2 {};
6441 template <class U> struct S2<U*> {};
6444 we will be called with an ARGLIST of `U*', but the
6445 TEMPLATE will be `template <class T> template
6446 <class U> struct S1<T>::S2'. We must fill in the missing
6449 = add_outermost_template_args (TYPE_TI_ARGS (TREE_TYPE (templ)),
6451 arg_depth = TMPL_ARGS_DEPTH (arglist);
6454 /* Now we should have enough arguments. */
6455 gcc_assert (parm_depth == arg_depth);
6457 /* From here on, we're only interested in the most general
6460 /* Calculate the BOUND_ARGS. These will be the args that are
6461 actually tsubst'd into the definition to create the
6465 /* We have multiple levels of arguments to coerce, at once. */
6467 int saved_depth = TMPL_ARGS_DEPTH (arglist);
6469 tree bound_args = make_tree_vec (parm_depth);
6471 for (i = saved_depth,
6472 t = DECL_TEMPLATE_PARMS (gen_tmpl);
6473 i > 0 && t != NULL_TREE;
6474 --i, t = TREE_CHAIN (t))
6476 tree a = coerce_template_parms (TREE_VALUE (t),
6479 /*require_all_args=*/true,
6480 /*use_default_args=*/true);
6482 /* Don't process further if one of the levels fails. */
6483 if (a == error_mark_node)
6485 /* Restore the ARGLIST to its full size. */
6486 TREE_VEC_LENGTH (arglist) = saved_depth;
6487 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6490 SET_TMPL_ARGS_LEVEL (bound_args, i, a);
6492 /* We temporarily reduce the length of the ARGLIST so
6493 that coerce_template_parms will see only the arguments
6494 corresponding to the template parameters it is
6496 TREE_VEC_LENGTH (arglist)--;
6499 /* Restore the ARGLIST to its full size. */
6500 TREE_VEC_LENGTH (arglist) = saved_depth;
6502 arglist = bound_args;
6506 = coerce_template_parms (INNERMOST_TEMPLATE_PARMS (parmlist),
6507 INNERMOST_TEMPLATE_ARGS (arglist),
6510 /*require_all_args=*/true,
6511 /*use_default_args=*/true);
6513 if (arglist == error_mark_node)
6514 /* We were unable to bind the arguments. */
6515 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6517 /* In the scope of a template class, explicit references to the
6518 template class refer to the type of the template, not any
6519 instantiation of it. For example, in:
6521 template <class T> class C { void f(C<T>); }
6523 the `C<T>' is just the same as `C'. Outside of the
6524 class, however, such a reference is an instantiation. */
6526 || !PRIMARY_TEMPLATE_P (gen_tmpl)
6527 || currently_open_class (template_type))
6528 /* comp_template_args is expensive, check it last. */
6529 && comp_template_args (TYPE_TI_ARGS (template_type),
6531 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, template_type);
6533 /* If we already have this specialization, return it. */
6534 elt.tmpl = gen_tmpl;
6536 hash = hash_specialization (&elt);
6537 entry = (spec_entry *) htab_find_with_hash (type_specializations,
6541 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, entry->spec);
6543 is_dependent_type = uses_template_parms (arglist);
6545 /* If the deduced arguments are invalid, then the binding
6547 if (!is_dependent_type
6548 && check_instantiated_args (gen_tmpl,
6549 INNERMOST_TEMPLATE_ARGS (arglist),
6551 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, error_mark_node);
6553 if (!is_dependent_type
6554 && !PRIMARY_TEMPLATE_P (gen_tmpl)
6555 && !LAMBDA_TYPE_P (TREE_TYPE (gen_tmpl))
6556 && TREE_CODE (CP_DECL_CONTEXT (gen_tmpl)) == NAMESPACE_DECL)
6558 found = xref_tag_from_type (TREE_TYPE (gen_tmpl),
6559 DECL_NAME (gen_tmpl),
6560 /*tag_scope=*/ts_global);
6561 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, found);
6564 context = tsubst (DECL_CONTEXT (gen_tmpl), arglist,
6567 context = global_namespace;
6569 /* Create the type. */
6570 if (TREE_CODE (template_type) == ENUMERAL_TYPE)
6572 if (!is_dependent_type)
6574 set_current_access_from_decl (TYPE_NAME (template_type));
6575 t = start_enum (TYPE_IDENTIFIER (template_type),
6576 tsubst (ENUM_UNDERLYING_TYPE (template_type),
6577 arglist, complain, in_decl),
6578 SCOPED_ENUM_P (template_type));
6582 /* We don't want to call start_enum for this type, since
6583 the values for the enumeration constants may involve
6584 template parameters. And, no one should be interested
6585 in the enumeration constants for such a type. */
6586 t = cxx_make_type (ENUMERAL_TYPE);
6587 SET_SCOPED_ENUM_P (t, SCOPED_ENUM_P (template_type));
6592 t = make_class_type (TREE_CODE (template_type));
6593 CLASSTYPE_DECLARED_CLASS (t)
6594 = CLASSTYPE_DECLARED_CLASS (template_type);
6595 SET_CLASSTYPE_IMPLICIT_INSTANTIATION (t);
6596 TYPE_FOR_JAVA (t) = TYPE_FOR_JAVA (template_type);
6598 /* A local class. Make sure the decl gets registered properly. */
6599 if (context == current_function_decl)
6600 pushtag (DECL_NAME (gen_tmpl), t, /*tag_scope=*/ts_current);
6602 if (comp_template_args (CLASSTYPE_TI_ARGS (template_type), arglist))
6603 /* This instantiation is another name for the primary
6604 template type. Set the TYPE_CANONICAL field
6606 TYPE_CANONICAL (t) = template_type;
6607 else if (any_template_arguments_need_structural_equality_p (arglist))
6608 /* Some of the template arguments require structural
6609 equality testing, so this template class requires
6610 structural equality testing. */
6611 SET_TYPE_STRUCTURAL_EQUALITY (t);
6614 /* If we called start_enum or pushtag above, this information
6615 will already be set up. */
6618 TYPE_CONTEXT (t) = FROB_CONTEXT (context);
6620 type_decl = create_implicit_typedef (DECL_NAME (gen_tmpl), t);
6621 DECL_CONTEXT (type_decl) = TYPE_CONTEXT (t);
6622 DECL_SOURCE_LOCATION (type_decl)
6623 = DECL_SOURCE_LOCATION (TYPE_STUB_DECL (template_type));
6626 type_decl = TYPE_NAME (t);
6628 TREE_PRIVATE (type_decl)
6629 = TREE_PRIVATE (TYPE_STUB_DECL (template_type));
6630 TREE_PROTECTED (type_decl)
6631 = TREE_PROTECTED (TYPE_STUB_DECL (template_type));
6632 if (CLASSTYPE_VISIBILITY_SPECIFIED (template_type))
6634 DECL_VISIBILITY_SPECIFIED (type_decl) = 1;
6635 DECL_VISIBILITY (type_decl) = CLASSTYPE_VISIBILITY (template_type);
6638 /* Let's consider the explicit specialization of a member
6639 of a class template specialization that is implicitely instantiated,
6644 template<class U> struct M {}; //#0
6649 struct S<int>::M<char> //#1
6653 [temp.expl.spec]/4 says this is valid.
6655 In this case, when we write:
6658 M is instantiated from the CLASSTYPE_TI_TEMPLATE of #1, not from
6661 When we encounter #1, we want to store the partial instantiation
6662 of M (template<class T> S<int>::M<T>) in it's CLASSTYPE_TI_TEMPLATE.
6664 For all cases other than this "explicit specialization of member of a
6665 class template", we just want to store the most general template into
6666 the CLASSTYPE_TI_TEMPLATE of M.
6668 This case of "explicit specialization of member of a class template"
6670 1/ the enclosing class is an instantiation of, and therefore not
6671 the same as, the context of the most general template, and
6672 2/ we aren't looking at the partial instantiation itself, i.e.
6673 the innermost arguments are not the same as the innermost parms of
6674 the most general template.
6676 So it's only when 1/ and 2/ happens that we want to use the partial
6677 instantiation of the member template in lieu of its most general
6680 if (PRIMARY_TEMPLATE_P (gen_tmpl)
6681 && TMPL_ARGS_HAVE_MULTIPLE_LEVELS (arglist)
6682 /* the enclosing class must be an instantiation... */
6683 && CLASS_TYPE_P (context)
6684 && !same_type_p (context, DECL_CONTEXT (gen_tmpl)))
6686 tree partial_inst_args;
6687 TREE_VEC_LENGTH (arglist)--;
6688 ++processing_template_decl;
6690 tsubst (INNERMOST_TEMPLATE_ARGS
6691 (CLASSTYPE_TI_ARGS (TREE_TYPE (gen_tmpl))),
6692 arglist, complain, NULL_TREE);
6693 --processing_template_decl;
6694 TREE_VEC_LENGTH (arglist)++;
6695 use_partial_inst_tmpl =
6696 /*...and we must not be looking at the partial instantiation
6698 !comp_template_args (INNERMOST_TEMPLATE_ARGS (arglist),
6702 if (!use_partial_inst_tmpl)
6703 /* This case is easy; there are no member templates involved. */
6707 /* This is a full instantiation of a member template. Find
6708 the partial instantiation of which this is an instance. */
6710 /* Temporarily reduce by one the number of levels in the ARGLIST
6711 so as to avoid comparing the last set of arguments. */
6712 TREE_VEC_LENGTH (arglist)--;
6713 found = tsubst (gen_tmpl, arglist, complain, NULL_TREE);
6714 TREE_VEC_LENGTH (arglist)++;
6715 found = CLASSTYPE_TI_TEMPLATE (found);
6718 SET_TYPE_TEMPLATE_INFO (t, build_template_info (found, arglist));
6721 slot = (spec_entry **) htab_find_slot_with_hash (type_specializations,
6722 &elt, hash, INSERT);
6723 *slot = GGC_NEW (spec_entry);
6726 /* Note this use of the partial instantiation so we can check it
6727 later in maybe_process_partial_specialization. */
6728 DECL_TEMPLATE_INSTANTIATIONS (templ)
6729 = tree_cons (arglist, t,
6730 DECL_TEMPLATE_INSTANTIATIONS (templ));
6732 if (TREE_CODE (t) == ENUMERAL_TYPE && !is_dependent_type)
6733 /* Now that the type has been registered on the instantiations
6734 list, we set up the enumerators. Because the enumeration
6735 constants may involve the enumeration type itself, we make
6736 sure to register the type first, and then create the
6737 constants. That way, doing tsubst_expr for the enumeration
6738 constants won't result in recursive calls here; we'll find
6739 the instantiation and exit above. */
6740 tsubst_enum (template_type, t, arglist);
6742 if (is_dependent_type)
6743 /* If the type makes use of template parameters, the
6744 code that generates debugging information will crash. */
6745 DECL_IGNORED_P (TYPE_STUB_DECL (t)) = 1;
6747 /* Possibly limit visibility based on template args. */
6748 TREE_PUBLIC (type_decl) = 1;
6749 determine_visibility (type_decl);
6751 POP_TIMEVAR_AND_RETURN (TV_NAME_LOOKUP, t);
6753 timevar_pop (TV_NAME_LOOKUP);
6760 /* True when we should also visit template parameters that occur in
6761 non-deduced contexts. */
6762 bool include_nondeduced_p;
6763 struct pointer_set_t *visited;
6766 /* Called from for_each_template_parm via walk_tree. */
6769 for_each_template_parm_r (tree *tp, int *walk_subtrees, void *d)
6772 struct pair_fn_data *pfd = (struct pair_fn_data *) d;
6773 tree_fn_t fn = pfd->fn;
6774 void *data = pfd->data;
6777 && (pfd->include_nondeduced_p || TREE_CODE (t) != TYPENAME_TYPE)
6778 && for_each_template_parm (TYPE_CONTEXT (t), fn, data, pfd->visited,
6779 pfd->include_nondeduced_p))
6780 return error_mark_node;
6782 switch (TREE_CODE (t))
6785 if (TYPE_PTRMEMFUNC_P (t))
6791 if (!TYPE_TEMPLATE_INFO (t))
6793 else if (for_each_template_parm (TI_ARGS (TYPE_TEMPLATE_INFO (t)),
6794 fn, data, pfd->visited,
6795 pfd->include_nondeduced_p))
6796 return error_mark_node;
6800 if (for_each_template_parm (TYPE_MIN_VALUE (t),
6801 fn, data, pfd->visited,
6802 pfd->include_nondeduced_p)
6803 || for_each_template_parm (TYPE_MAX_VALUE (t),
6804 fn, data, pfd->visited,
6805 pfd->include_nondeduced_p))
6806 return error_mark_node;
6810 /* Since we're not going to walk subtrees, we have to do this
6812 if (for_each_template_parm (TYPE_METHOD_BASETYPE (t), fn, data,
6813 pfd->visited, pfd->include_nondeduced_p))
6814 return error_mark_node;
6818 /* Check the return type. */
6819 if (for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
6820 pfd->include_nondeduced_p))
6821 return error_mark_node;
6823 /* Check the parameter types. Since default arguments are not
6824 instantiated until they are needed, the TYPE_ARG_TYPES may
6825 contain expressions that involve template parameters. But,
6826 no-one should be looking at them yet. And, once they're
6827 instantiated, they don't contain template parameters, so
6828 there's no point in looking at them then, either. */
6832 for (parm = TYPE_ARG_TYPES (t); parm; parm = TREE_CHAIN (parm))
6833 if (for_each_template_parm (TREE_VALUE (parm), fn, data,
6834 pfd->visited, pfd->include_nondeduced_p))
6835 return error_mark_node;
6837 /* Since we've already handled the TYPE_ARG_TYPES, we don't
6838 want walk_tree walking into them itself. */
6844 if (pfd->include_nondeduced_p
6845 && for_each_template_parm (TYPE_FIELDS (t), fn, data,
6847 pfd->include_nondeduced_p))
6848 return error_mark_node;
6853 if (DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t)
6854 && for_each_template_parm (DECL_TI_ARGS (t), fn, data,
6855 pfd->visited, pfd->include_nondeduced_p))
6856 return error_mark_node;
6861 if (TREE_CODE (t) == CONST_DECL && DECL_TEMPLATE_PARM_P (t)
6862 && for_each_template_parm (DECL_INITIAL (t), fn, data,
6863 pfd->visited, pfd->include_nondeduced_p))
6864 return error_mark_node;
6865 if (DECL_CONTEXT (t)
6866 && pfd->include_nondeduced_p
6867 && for_each_template_parm (DECL_CONTEXT (t), fn, data,
6868 pfd->visited, pfd->include_nondeduced_p))
6869 return error_mark_node;
6872 case BOUND_TEMPLATE_TEMPLATE_PARM:
6873 /* Record template parameters such as `T' inside `TT<T>'. */
6874 if (for_each_template_parm (TYPE_TI_ARGS (t), fn, data, pfd->visited,
6875 pfd->include_nondeduced_p))
6876 return error_mark_node;
6879 case TEMPLATE_TEMPLATE_PARM:
6880 case TEMPLATE_TYPE_PARM:
6881 case TEMPLATE_PARM_INDEX:
6882 if (fn && (*fn)(t, data))
6883 return error_mark_node;
6885 return error_mark_node;
6889 /* A template template parameter is encountered. */
6890 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t)
6891 && for_each_template_parm (TREE_TYPE (t), fn, data, pfd->visited,
6892 pfd->include_nondeduced_p))
6893 return error_mark_node;
6895 /* Already substituted template template parameter */
6901 || for_each_template_parm (TYPENAME_TYPE_FULLNAME (t), fn,
6903 pfd->include_nondeduced_p))
6904 return error_mark_node;
6908 if (TREE_TYPE (t) && TYPE_PTRMEMFUNC_P (TREE_TYPE (t))
6909 && pfd->include_nondeduced_p
6910 && for_each_template_parm (TYPE_PTRMEMFUNC_FN_TYPE
6911 (TREE_TYPE (t)), fn, data,
6912 pfd->visited, pfd->include_nondeduced_p))
6913 return error_mark_node;
6918 /* If there's no type, then this thing must be some expression
6919 involving template parameters. */
6920 if (!fn && !TREE_TYPE (t))
6921 return error_mark_node;
6926 case REINTERPRET_CAST_EXPR:
6927 case CONST_CAST_EXPR:
6928 case STATIC_CAST_EXPR:
6929 case DYNAMIC_CAST_EXPR:
6933 case PSEUDO_DTOR_EXPR:
6935 return error_mark_node;
6942 /* We didn't find any template parameters we liked. */
6946 /* For each TEMPLATE_TYPE_PARM, TEMPLATE_TEMPLATE_PARM,
6947 BOUND_TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX in T,
6948 call FN with the parameter and the DATA.
6949 If FN returns nonzero, the iteration is terminated, and
6950 for_each_template_parm returns 1. Otherwise, the iteration
6951 continues. If FN never returns a nonzero value, the value
6952 returned by for_each_template_parm is 0. If FN is NULL, it is
6953 considered to be the function which always returns 1.
6955 If INCLUDE_NONDEDUCED_P, then this routine will also visit template
6956 parameters that occur in non-deduced contexts. When false, only
6957 visits those template parameters that can be deduced. */
6960 for_each_template_parm (tree t, tree_fn_t fn, void* data,
6961 struct pointer_set_t *visited,
6962 bool include_nondeduced_p)
6964 struct pair_fn_data pfd;
6970 pfd.include_nondeduced_p = include_nondeduced_p;
6972 /* Walk the tree. (Conceptually, we would like to walk without
6973 duplicates, but for_each_template_parm_r recursively calls
6974 for_each_template_parm, so we would need to reorganize a fair
6975 bit to use walk_tree_without_duplicates, so we keep our own
6978 pfd.visited = visited;
6980 pfd.visited = pointer_set_create ();
6981 result = cp_walk_tree (&t,
6982 for_each_template_parm_r,
6984 pfd.visited) != NULL_TREE;
6989 pointer_set_destroy (pfd.visited);
6996 /* Returns true if T depends on any template parameter. */
6999 uses_template_parms (tree t)
7002 int saved_processing_template_decl;
7004 saved_processing_template_decl = processing_template_decl;
7005 if (!saved_processing_template_decl)
7006 processing_template_decl = 1;
7008 dependent_p = dependent_type_p (t);
7009 else if (TREE_CODE (t) == TREE_VEC)
7010 dependent_p = any_dependent_template_arguments_p (t);
7011 else if (TREE_CODE (t) == TREE_LIST)
7012 dependent_p = (uses_template_parms (TREE_VALUE (t))
7013 || uses_template_parms (TREE_CHAIN (t)));
7014 else if (TREE_CODE (t) == TYPE_DECL)
7015 dependent_p = dependent_type_p (TREE_TYPE (t));
7018 || TREE_CODE (t) == TEMPLATE_PARM_INDEX
7019 || TREE_CODE (t) == OVERLOAD
7020 || TREE_CODE (t) == BASELINK
7021 || TREE_CODE (t) == IDENTIFIER_NODE
7022 || TREE_CODE (t) == TRAIT_EXPR
7023 || TREE_CODE (t) == CONSTRUCTOR
7024 || CONSTANT_CLASS_P (t))
7025 dependent_p = (type_dependent_expression_p (t)
7026 || value_dependent_expression_p (t));
7029 gcc_assert (t == error_mark_node);
7030 dependent_p = false;
7033 processing_template_decl = saved_processing_template_decl;
7038 /* Returns true if T depends on any template parameter with level LEVEL. */
7041 uses_template_parms_level (tree t, int level)
7043 return for_each_template_parm (t, template_parm_this_level_p, &level, NULL,
7044 /*include_nondeduced_p=*/true);
7047 static int tinst_depth;
7048 extern int max_tinst_depth;
7049 #ifdef GATHER_STATISTICS
7052 static int tinst_level_tick;
7053 static int last_template_error_tick;
7055 /* We're starting to instantiate D; record the template instantiation context
7056 for diagnostics and to restore it later. */
7059 push_tinst_level (tree d)
7061 struct tinst_level *new_level;
7063 if (tinst_depth >= max_tinst_depth)
7065 /* If the instantiation in question still has unbound template parms,
7066 we don't really care if we can't instantiate it, so just return.
7067 This happens with base instantiation for implicit `typename'. */
7068 if (uses_template_parms (d))
7071 last_template_error_tick = tinst_level_tick;
7072 error ("template instantiation depth exceeds maximum of %d (use "
7073 "-ftemplate-depth= to increase the maximum) instantiating %qD",
7074 max_tinst_depth, d);
7076 print_instantiation_context ();
7081 new_level = GGC_NEW (struct tinst_level);
7082 new_level->decl = d;
7083 new_level->locus = input_location;
7084 new_level->in_system_header_p = in_system_header;
7085 new_level->next = current_tinst_level;
7086 current_tinst_level = new_level;
7089 #ifdef GATHER_STATISTICS
7090 if (tinst_depth > depth_reached)
7091 depth_reached = tinst_depth;
7098 /* We're done instantiating this template; return to the instantiation
7102 pop_tinst_level (void)
7104 /* Restore the filename and line number stashed away when we started
7105 this instantiation. */
7106 input_location = current_tinst_level->locus;
7107 current_tinst_level = current_tinst_level->next;
7112 /* We're instantiating a deferred template; restore the template
7113 instantiation context in which the instantiation was requested, which
7114 is one step out from LEVEL. Return the corresponding DECL or TYPE. */
7117 reopen_tinst_level (struct tinst_level *level)
7119 struct tinst_level *t;
7122 for (t = level; t; t = t->next)
7125 current_tinst_level = level;
7130 /* Returns the TINST_LEVEL which gives the original instantiation
7133 struct tinst_level *
7134 outermost_tinst_level (void)
7136 struct tinst_level *level = current_tinst_level;
7139 level = level->next;
7143 /* Returns TRUE if PARM is a parameter of the template TEMPL. */
7146 parameter_of_template_p (tree parm, tree templ)
7151 if (!parm || !templ)
7154 gcc_assert (DECL_TEMPLATE_PARM_P (parm));
7155 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
7157 parms = DECL_TEMPLATE_PARMS (templ);
7158 parms = INNERMOST_TEMPLATE_PARMS (parms);
7160 for (i = 0; i < TREE_VEC_LENGTH (parms); ++i)
7161 if (parm == TREE_VALUE (TREE_VEC_ELT (parms, i)))
7167 /* DECL is a friend FUNCTION_DECL or TEMPLATE_DECL. ARGS is the
7168 vector of template arguments, as for tsubst.
7170 Returns an appropriate tsubst'd friend declaration. */
7173 tsubst_friend_function (tree decl, tree args)
7177 if (TREE_CODE (decl) == FUNCTION_DECL
7178 && DECL_TEMPLATE_INSTANTIATION (decl)
7179 && TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
7180 /* This was a friend declared with an explicit template
7181 argument list, e.g.:
7185 to indicate that f was a template instantiation, not a new
7186 function declaration. Now, we have to figure out what
7187 instantiation of what template. */
7189 tree template_id, arglist, fns;
7192 tree ns = decl_namespace_context (TYPE_MAIN_DECL (current_class_type));
7194 /* Friend functions are looked up in the containing namespace scope.
7195 We must enter that scope, to avoid finding member functions of the
7196 current class with same name. */
7197 push_nested_namespace (ns);
7198 fns = tsubst_expr (DECL_TI_TEMPLATE (decl), args,
7199 tf_warning_or_error, NULL_TREE,
7200 /*integral_constant_expression_p=*/false);
7201 pop_nested_namespace (ns);
7202 arglist = tsubst (DECL_TI_ARGS (decl), args,
7203 tf_warning_or_error, NULL_TREE);
7204 template_id = lookup_template_function (fns, arglist);
7206 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
7207 tmpl = determine_specialization (template_id, new_friend,
7209 /*need_member_template=*/0,
7210 TREE_VEC_LENGTH (args),
7212 return instantiate_template (tmpl, new_args, tf_error);
7215 new_friend = tsubst (decl, args, tf_warning_or_error, NULL_TREE);
7217 /* The NEW_FRIEND will look like an instantiation, to the
7218 compiler, but is not an instantiation from the point of view of
7219 the language. For example, we might have had:
7221 template <class T> struct S {
7222 template <class U> friend void f(T, U);
7225 Then, in S<int>, template <class U> void f(int, U) is not an
7226 instantiation of anything. */
7227 if (new_friend == error_mark_node)
7228 return error_mark_node;
7230 DECL_USE_TEMPLATE (new_friend) = 0;
7231 if (TREE_CODE (decl) == TEMPLATE_DECL)
7233 DECL_USE_TEMPLATE (DECL_TEMPLATE_RESULT (new_friend)) = 0;
7234 DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (new_friend))
7235 = DECL_SAVED_TREE (DECL_TEMPLATE_RESULT (decl));
7238 /* The mangled name for the NEW_FRIEND is incorrect. The function
7239 is not a template instantiation and should not be mangled like
7240 one. Therefore, we forget the mangling here; we'll recompute it
7241 later if we need it. */
7242 if (TREE_CODE (new_friend) != TEMPLATE_DECL)
7244 SET_DECL_RTL (new_friend, NULL_RTX);
7245 SET_DECL_ASSEMBLER_NAME (new_friend, NULL_TREE);
7248 if (DECL_NAMESPACE_SCOPE_P (new_friend))
7251 tree new_friend_template_info;
7252 tree new_friend_result_template_info;
7254 int new_friend_is_defn;
7256 /* We must save some information from NEW_FRIEND before calling
7257 duplicate decls since that function will free NEW_FRIEND if
7259 new_friend_template_info = DECL_TEMPLATE_INFO (new_friend);
7260 new_friend_is_defn =
7261 (DECL_INITIAL (DECL_TEMPLATE_RESULT
7262 (template_for_substitution (new_friend)))
7264 if (TREE_CODE (new_friend) == TEMPLATE_DECL)
7266 /* This declaration is a `primary' template. */
7267 DECL_PRIMARY_TEMPLATE (new_friend) = new_friend;
7269 new_friend_result_template_info
7270 = DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (new_friend));
7273 new_friend_result_template_info = NULL_TREE;
7275 /* Make the init_value nonzero so pushdecl knows this is a defn. */
7276 if (new_friend_is_defn)
7277 DECL_INITIAL (new_friend) = error_mark_node;
7279 /* Inside pushdecl_namespace_level, we will push into the
7280 current namespace. However, the friend function should go
7281 into the namespace of the template. */
7282 ns = decl_namespace_context (new_friend);
7283 push_nested_namespace (ns);
7284 old_decl = pushdecl_namespace_level (new_friend, /*is_friend=*/true);
7285 pop_nested_namespace (ns);
7287 if (old_decl == error_mark_node)
7288 return error_mark_node;
7290 if (old_decl != new_friend)
7292 /* This new friend declaration matched an existing
7293 declaration. For example, given:
7295 template <class T> void f(T);
7296 template <class U> class C {
7297 template <class T> friend void f(T) {}
7300 the friend declaration actually provides the definition
7301 of `f', once C has been instantiated for some type. So,
7302 old_decl will be the out-of-class template declaration,
7303 while new_friend is the in-class definition.
7305 But, if `f' was called before this point, the
7306 instantiation of `f' will have DECL_TI_ARGS corresponding
7307 to `T' but not to `U', references to which might appear
7308 in the definition of `f'. Previously, the most general
7309 template for an instantiation of `f' was the out-of-class
7310 version; now it is the in-class version. Therefore, we
7311 run through all specialization of `f', adding to their
7312 DECL_TI_ARGS appropriately. In particular, they need a
7313 new set of outer arguments, corresponding to the
7314 arguments for this class instantiation.
7316 The same situation can arise with something like this:
7319 template <class T> class C {
7323 when `C<int>' is instantiated. Now, `f(int)' is defined
7326 if (!new_friend_is_defn)
7327 /* On the other hand, if the in-class declaration does
7328 *not* provide a definition, then we don't want to alter
7329 existing definitions. We can just leave everything
7334 tree new_template = TI_TEMPLATE (new_friend_template_info);
7335 tree new_args = TI_ARGS (new_friend_template_info);
7337 /* Overwrite whatever template info was there before, if
7338 any, with the new template information pertaining to
7340 DECL_TEMPLATE_INFO (old_decl) = new_friend_template_info;
7342 if (TREE_CODE (old_decl) != TEMPLATE_DECL)
7344 /* We should have called reregister_specialization in
7346 gcc_assert (retrieve_specialization (new_template,
7350 /* Instantiate it if the global has already been used. */
7351 if (DECL_ODR_USED (old_decl))
7352 instantiate_decl (old_decl, /*defer_ok=*/true,
7353 /*expl_inst_class_mem_p=*/false);
7359 /* Indicate that the old function template is a partial
7361 DECL_TEMPLATE_INFO (DECL_TEMPLATE_RESULT (old_decl))
7362 = new_friend_result_template_info;
7364 gcc_assert (new_template
7365 == most_general_template (new_template));
7366 gcc_assert (new_template != old_decl);
7368 /* Reassign any specializations already in the hash table
7369 to the new more general template, and add the
7370 additional template args. */
7371 for (t = DECL_TEMPLATE_INSTANTIATIONS (old_decl);
7375 tree spec = TREE_VALUE (t);
7378 elt.tmpl = old_decl;
7379 elt.args = DECL_TI_ARGS (spec);
7380 elt.spec = NULL_TREE;
7382 htab_remove_elt (decl_specializations, &elt);
7385 = add_outermost_template_args (new_args,
7386 DECL_TI_ARGS (spec));
7388 register_specialization
7389 (spec, new_template, DECL_TI_ARGS (spec), true, 0);
7392 DECL_TEMPLATE_INSTANTIATIONS (old_decl) = NULL_TREE;
7396 /* The information from NEW_FRIEND has been merged into OLD_DECL
7397 by duplicate_decls. */
7398 new_friend = old_decl;
7403 tree context = DECL_CONTEXT (new_friend);
7407 template <class T> class C {
7408 template <class U> friend void C1<U>::f (); // case 1
7409 friend void C2<T>::f (); // case 2
7411 we only need to make sure CONTEXT is a complete type for
7412 case 2. To distinguish between the two cases, we note that
7413 CONTEXT of case 1 remains dependent type after tsubst while
7414 this isn't true for case 2. */
7415 ++processing_template_decl;
7416 dependent_p = dependent_type_p (context);
7417 --processing_template_decl;
7420 && !complete_type_or_else (context, NULL_TREE))
7421 return error_mark_node;
7423 if (COMPLETE_TYPE_P (context))
7425 /* Check to see that the declaration is really present, and,
7426 possibly obtain an improved declaration. */
7427 tree fn = check_classfn (context,
7428 new_friend, NULL_TREE);
7438 /* FRIEND_TMPL is a friend TEMPLATE_DECL. ARGS is the vector of
7439 template arguments, as for tsubst.
7441 Returns an appropriate tsubst'd friend type or error_mark_node on
7445 tsubst_friend_class (tree friend_tmpl, tree args)
7451 context = DECL_CONTEXT (friend_tmpl);
7455 if (TREE_CODE (context) == NAMESPACE_DECL)
7456 push_nested_namespace (context);
7458 push_nested_class (tsubst (context, args, tf_none, NULL_TREE));
7461 /* Look for a class template declaration. We look for hidden names
7462 because two friend declarations of the same template are the
7463 same. For example, in:
7466 template <typename> friend class F;
7468 template <typename> struct B {
7469 template <typename> friend class F;
7472 both F templates are the same. */
7473 tmpl = lookup_name_real (DECL_NAME (friend_tmpl), 0, 0,
7474 /*block_p=*/true, 0,
7475 LOOKUP_COMPLAIN | LOOKUP_HIDDEN);
7477 /* But, if we don't find one, it might be because we're in a
7478 situation like this:
7486 Here, in the scope of (say) S<int>, `S' is bound to a TYPE_DECL
7487 for `S<int>', not the TEMPLATE_DECL. */
7488 if (!tmpl || !DECL_CLASS_TEMPLATE_P (tmpl))
7490 tmpl = lookup_name_prefer_type (DECL_NAME (friend_tmpl), 1);
7491 tmpl = maybe_get_template_decl_from_type_decl (tmpl);
7494 if (tmpl && DECL_CLASS_TEMPLATE_P (tmpl))
7496 /* The friend template has already been declared. Just
7497 check to see that the declarations match, and install any new
7498 default parameters. We must tsubst the default parameters,
7499 of course. We only need the innermost template parameters
7500 because that is all that redeclare_class_template will look
7502 if (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (friend_tmpl))
7503 > TMPL_ARGS_DEPTH (args))
7506 location_t saved_input_location;
7507 parms = tsubst_template_parms (DECL_TEMPLATE_PARMS (friend_tmpl),
7508 args, tf_warning_or_error);
7510 saved_input_location = input_location;
7511 input_location = DECL_SOURCE_LOCATION (friend_tmpl);
7512 redeclare_class_template (TREE_TYPE (tmpl), parms);
7513 input_location = saved_input_location;
7517 friend_type = TREE_TYPE (tmpl);
7521 /* The friend template has not already been declared. In this
7522 case, the instantiation of the template class will cause the
7523 injection of this template into the global scope. */
7524 tmpl = tsubst (friend_tmpl, args, tf_warning_or_error, NULL_TREE);
7525 if (tmpl == error_mark_node)
7526 return error_mark_node;
7528 /* The new TMPL is not an instantiation of anything, so we
7529 forget its origins. We don't reset CLASSTYPE_TI_TEMPLATE for
7530 the new type because that is supposed to be the corresponding
7531 template decl, i.e., TMPL. */
7532 DECL_USE_TEMPLATE (tmpl) = 0;
7533 DECL_TEMPLATE_INFO (tmpl) = NULL_TREE;
7534 CLASSTYPE_USE_TEMPLATE (TREE_TYPE (tmpl)) = 0;
7535 CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl))
7536 = INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (TREE_TYPE (tmpl)));
7538 /* Inject this template into the global scope. */
7539 friend_type = TREE_TYPE (pushdecl_top_level_maybe_friend (tmpl, true));
7544 if (TREE_CODE (context) == NAMESPACE_DECL)
7545 pop_nested_namespace (context);
7547 pop_nested_class ();
7553 /* Returns zero if TYPE cannot be completed later due to circularity.
7554 Otherwise returns one. */
7557 can_complete_type_without_circularity (tree type)
7559 if (type == NULL_TREE || type == error_mark_node)
7561 else if (COMPLETE_TYPE_P (type))
7563 else if (TREE_CODE (type) == ARRAY_TYPE && TYPE_DOMAIN (type))
7564 return can_complete_type_without_circularity (TREE_TYPE (type));
7565 else if (CLASS_TYPE_P (type)
7566 && TYPE_BEING_DEFINED (TYPE_MAIN_VARIANT (type)))
7572 /* Apply any attributes which had to be deferred until instantiation
7573 time. DECL_P, ATTRIBUTES and ATTR_FLAGS are as cplus_decl_attributes;
7574 ARGS, COMPLAIN, IN_DECL are as tsubst. */
7577 apply_late_template_attributes (tree *decl_p, tree attributes, int attr_flags,
7578 tree args, tsubst_flags_t complain, tree in_decl)
7580 tree last_dep = NULL_TREE;
7584 for (t = attributes; t; t = TREE_CHAIN (t))
7585 if (ATTR_IS_DEPENDENT (t))
7588 attributes = copy_list (attributes);
7592 if (DECL_P (*decl_p))
7594 if (TREE_TYPE (*decl_p) == error_mark_node)
7596 p = &DECL_ATTRIBUTES (*decl_p);
7599 p = &TYPE_ATTRIBUTES (*decl_p);
7603 tree late_attrs = NULL_TREE;
7604 tree *q = &late_attrs;
7606 for (*p = attributes; *p; )
7609 if (ATTR_IS_DEPENDENT (t))
7611 *p = TREE_CHAIN (t);
7612 TREE_CHAIN (t) = NULL_TREE;
7613 /* If the first attribute argument is an identifier, don't
7614 pass it through tsubst. Attributes like mode, format,
7615 cleanup and several target specific attributes expect it
7618 && TREE_CODE (TREE_VALUE (t)) == TREE_LIST
7619 && TREE_VALUE (TREE_VALUE (t))
7620 && (TREE_CODE (TREE_VALUE (TREE_VALUE (t)))
7621 == IDENTIFIER_NODE))
7624 = tsubst_expr (TREE_CHAIN (TREE_VALUE (t)), args, complain,
7626 /*integral_constant_expression_p=*/false);
7627 if (chain != TREE_CHAIN (TREE_VALUE (t)))
7629 = tree_cons (NULL_TREE, TREE_VALUE (TREE_VALUE (t)),
7634 = tsubst_expr (TREE_VALUE (t), args, complain, in_decl,
7635 /*integral_constant_expression_p=*/false);
7637 q = &TREE_CHAIN (t);
7640 p = &TREE_CHAIN (t);
7643 cplus_decl_attributes (decl_p, late_attrs, attr_flags);
7647 /* Perform (or defer) access check for typedefs that were referenced
7648 from within the template TMPL code.
7649 This is a subroutine of instantiate_template and instantiate_class_template.
7650 TMPL is the template to consider and TARGS is the list of arguments of
7654 perform_typedefs_access_check (tree tmpl, tree targs)
7656 location_t saved_location;
7658 qualified_typedef_usage_t *iter;
7661 || (!CLASS_TYPE_P (tmpl)
7662 && TREE_CODE (tmpl) != FUNCTION_DECL))
7665 saved_location = input_location;
7667 VEC_iterate (qualified_typedef_usage_t,
7668 get_types_needing_access_check (tmpl),
7672 tree type_decl = iter->typedef_decl;
7673 tree type_scope = iter->context;
7675 if (!type_decl || !type_scope || !CLASS_TYPE_P (type_scope))
7678 if (uses_template_parms (type_decl))
7679 type_decl = tsubst (type_decl, targs, tf_error, NULL_TREE);
7680 if (uses_template_parms (type_scope))
7681 type_scope = tsubst (type_scope, targs, tf_error, NULL_TREE);
7683 /* Make access check error messages point to the location
7684 of the use of the typedef. */
7685 input_location = iter->locus;
7686 perform_or_defer_access_check (TYPE_BINFO (type_scope),
7687 type_decl, type_decl);
7689 input_location = saved_location;
7693 instantiate_class_template (tree type)
7695 tree templ, args, pattern, t, member;
7699 unsigned int saved_maximum_field_alignment;
7701 if (type == error_mark_node)
7702 return error_mark_node;
7704 if (TYPE_BEING_DEFINED (type)
7705 || COMPLETE_TYPE_P (type)
7706 || uses_template_parms (type))
7709 /* Figure out which template is being instantiated. */
7710 templ = most_general_template (CLASSTYPE_TI_TEMPLATE (type));
7711 gcc_assert (TREE_CODE (templ) == TEMPLATE_DECL);
7713 /* Determine what specialization of the original template to
7715 t = most_specialized_class (type, templ);
7716 if (t == error_mark_node)
7718 TYPE_BEING_DEFINED (type) = 1;
7719 return error_mark_node;
7723 /* This TYPE is actually an instantiation of a partial
7724 specialization. We replace the innermost set of ARGS with
7725 the arguments appropriate for substitution. For example,
7728 template <class T> struct S {};
7729 template <class T> struct S<T*> {};
7731 and supposing that we are instantiating S<int*>, ARGS will
7732 presently be {int*} -- but we need {int}. */
7733 pattern = TREE_TYPE (t);
7734 args = TREE_PURPOSE (t);
7738 pattern = TREE_TYPE (templ);
7739 args = CLASSTYPE_TI_ARGS (type);
7742 /* If the template we're instantiating is incomplete, then clearly
7743 there's nothing we can do. */
7744 if (!COMPLETE_TYPE_P (pattern))
7747 /* If we've recursively instantiated too many templates, stop. */
7748 if (! push_tinst_level (type))
7751 /* Now we're really doing the instantiation. Mark the type as in
7752 the process of being defined. */
7753 TYPE_BEING_DEFINED (type) = 1;
7755 /* We may be in the middle of deferred access check. Disable
7757 push_deferring_access_checks (dk_no_deferred);
7759 push_to_top_level ();
7760 /* Use #pragma pack from the template context. */
7761 saved_maximum_field_alignment = maximum_field_alignment;
7762 maximum_field_alignment = TYPE_PRECISION (pattern);
7764 SET_CLASSTYPE_INTERFACE_UNKNOWN (type);
7766 /* Set the input location to the most specialized template definition.
7767 This is needed if tsubsting causes an error. */
7768 typedecl = TYPE_MAIN_DECL (pattern);
7769 input_location = DECL_SOURCE_LOCATION (typedecl);
7771 TYPE_HAS_USER_CONSTRUCTOR (type) = TYPE_HAS_USER_CONSTRUCTOR (pattern);
7772 TYPE_HAS_NEW_OPERATOR (type) = TYPE_HAS_NEW_OPERATOR (pattern);
7773 TYPE_HAS_ARRAY_NEW_OPERATOR (type) = TYPE_HAS_ARRAY_NEW_OPERATOR (pattern);
7774 TYPE_GETS_DELETE (type) = TYPE_GETS_DELETE (pattern);
7775 TYPE_HAS_ASSIGN_REF (type) = TYPE_HAS_ASSIGN_REF (pattern);
7776 TYPE_HAS_CONST_ASSIGN_REF (type) = TYPE_HAS_CONST_ASSIGN_REF (pattern);
7777 TYPE_HAS_INIT_REF (type) = TYPE_HAS_INIT_REF (pattern);
7778 TYPE_HAS_CONST_INIT_REF (type) = TYPE_HAS_CONST_INIT_REF (pattern);
7779 TYPE_HAS_DEFAULT_CONSTRUCTOR (type) = TYPE_HAS_DEFAULT_CONSTRUCTOR (pattern);
7780 TYPE_HAS_CONVERSION (type) = TYPE_HAS_CONVERSION (pattern);
7781 TYPE_PACKED (type) = TYPE_PACKED (pattern);
7782 TYPE_ALIGN (type) = TYPE_ALIGN (pattern);
7783 TYPE_USER_ALIGN (type) = TYPE_USER_ALIGN (pattern);
7784 TYPE_FOR_JAVA (type) = TYPE_FOR_JAVA (pattern); /* For libjava's JArray<T> */
7785 if (ANON_AGGR_TYPE_P (pattern))
7786 SET_ANON_AGGR_TYPE_P (type);
7787 if (CLASSTYPE_VISIBILITY_SPECIFIED (pattern))
7789 CLASSTYPE_VISIBILITY_SPECIFIED (type) = 1;
7790 CLASSTYPE_VISIBILITY (type) = CLASSTYPE_VISIBILITY (pattern);
7793 pbinfo = TYPE_BINFO (pattern);
7795 /* We should never instantiate a nested class before its enclosing
7796 class; we need to look up the nested class by name before we can
7797 instantiate it, and that lookup should instantiate the enclosing
7799 gcc_assert (!DECL_CLASS_SCOPE_P (TYPE_MAIN_DECL (pattern))
7800 || COMPLETE_TYPE_P (TYPE_CONTEXT (type))
7801 || TYPE_BEING_DEFINED (TYPE_CONTEXT (type)));
7803 base_list = NULL_TREE;
7804 if (BINFO_N_BASE_BINFOS (pbinfo))
7807 tree context = TYPE_CONTEXT (type);
7811 /* We must enter the scope containing the type, as that is where
7812 the accessibility of types named in dependent bases are
7814 pushed_scope = push_scope (context ? context : global_namespace);
7816 /* Substitute into each of the bases to determine the actual
7818 for (i = 0; BINFO_BASE_ITERATE (pbinfo, i, pbase_binfo); i++)
7821 tree access = BINFO_BASE_ACCESS (pbinfo, i);
7822 tree expanded_bases = NULL_TREE;
7825 if (PACK_EXPANSION_P (BINFO_TYPE (pbase_binfo)))
7828 tsubst_pack_expansion (BINFO_TYPE (pbase_binfo),
7829 args, tf_error, NULL_TREE);
7830 if (expanded_bases == error_mark_node)
7833 len = TREE_VEC_LENGTH (expanded_bases);
7836 for (idx = 0; idx < len; idx++)
7839 /* Extract the already-expanded base class. */
7840 base = TREE_VEC_ELT (expanded_bases, idx);
7842 /* Substitute to figure out the base class. */
7843 base = tsubst (BINFO_TYPE (pbase_binfo), args, tf_error,
7846 if (base == error_mark_node)
7849 base_list = tree_cons (access, base, base_list);
7850 if (BINFO_VIRTUAL_P (pbase_binfo))
7851 TREE_TYPE (base_list) = integer_type_node;
7855 /* The list is now in reverse order; correct that. */
7856 base_list = nreverse (base_list);
7859 pop_scope (pushed_scope);
7861 /* Now call xref_basetypes to set up all the base-class
7863 xref_basetypes (type, base_list);
7865 apply_late_template_attributes (&type, TYPE_ATTRIBUTES (pattern),
7866 (int) ATTR_FLAG_TYPE_IN_PLACE,
7867 args, tf_error, NULL_TREE);
7869 /* Now that our base classes are set up, enter the scope of the
7870 class, so that name lookups into base classes, etc. will work
7871 correctly. This is precisely analogous to what we do in
7872 begin_class_definition when defining an ordinary non-template
7873 class, except we also need to push the enclosing classes. */
7874 push_nested_class (type);
7876 /* Now members are processed in the order of declaration. */
7877 for (member = CLASSTYPE_DECL_LIST (pattern);
7878 member; member = TREE_CHAIN (member))
7880 tree t = TREE_VALUE (member);
7882 if (TREE_PURPOSE (member))
7886 /* Build new CLASSTYPE_NESTED_UTDS. */
7889 bool class_template_p;
7891 class_template_p = (TREE_CODE (t) != ENUMERAL_TYPE
7892 && TYPE_LANG_SPECIFIC (t)
7893 && CLASSTYPE_IS_TEMPLATE (t));
7894 /* If the member is a class template, then -- even after
7895 substitution -- there may be dependent types in the
7896 template argument list for the class. We increment
7897 PROCESSING_TEMPLATE_DECL so that dependent_type_p, as
7898 that function will assume that no types are dependent
7899 when outside of a template. */
7900 if (class_template_p)
7901 ++processing_template_decl;
7902 newtag = tsubst (t, args, tf_error, NULL_TREE);
7903 if (class_template_p)
7904 --processing_template_decl;
7905 if (newtag == error_mark_node)
7908 if (TREE_CODE (newtag) != ENUMERAL_TYPE)
7910 tree name = TYPE_IDENTIFIER (t);
7912 if (class_template_p)
7913 /* Unfortunately, lookup_template_class sets
7914 CLASSTYPE_IMPLICIT_INSTANTIATION for a partial
7915 instantiation (i.e., for the type of a member
7916 template class nested within a template class.)
7917 This behavior is required for
7918 maybe_process_partial_specialization to work
7919 correctly, but is not accurate in this case;
7920 the TAG is not an instantiation of anything.
7921 (The corresponding TEMPLATE_DECL is an
7922 instantiation, but the TYPE is not.) */
7923 CLASSTYPE_USE_TEMPLATE (newtag) = 0;
7925 /* Now, we call pushtag to put this NEWTAG into the scope of
7926 TYPE. We first set up the IDENTIFIER_TYPE_VALUE to avoid
7927 pushtag calling push_template_decl. We don't have to do
7928 this for enums because it will already have been done in
7931 SET_IDENTIFIER_TYPE_VALUE (name, newtag);
7932 pushtag (name, newtag, /*tag_scope=*/ts_current);
7935 else if (TREE_CODE (t) == FUNCTION_DECL
7936 || DECL_FUNCTION_TEMPLATE_P (t))
7938 /* Build new TYPE_METHODS. */
7941 if (TREE_CODE (t) == TEMPLATE_DECL)
7942 ++processing_template_decl;
7943 r = tsubst (t, args, tf_error, NULL_TREE);
7944 if (TREE_CODE (t) == TEMPLATE_DECL)
7945 --processing_template_decl;
7946 set_current_access_from_decl (r);
7947 finish_member_declaration (r);
7951 /* Build new TYPE_FIELDS. */
7952 if (TREE_CODE (t) == STATIC_ASSERT)
7955 tsubst_expr (STATIC_ASSERT_CONDITION (t), args,
7956 tf_warning_or_error, NULL_TREE,
7957 /*integral_constant_expression_p=*/true);
7958 finish_static_assert (condition,
7959 STATIC_ASSERT_MESSAGE (t),
7960 STATIC_ASSERT_SOURCE_LOCATION (t),
7963 else if (TREE_CODE (t) != CONST_DECL)
7967 /* The file and line for this declaration, to
7968 assist in error message reporting. Since we
7969 called push_tinst_level above, we don't need to
7971 input_location = DECL_SOURCE_LOCATION (t);
7973 if (TREE_CODE (t) == TEMPLATE_DECL)
7974 ++processing_template_decl;
7975 r = tsubst (t, args, tf_warning_or_error, NULL_TREE);
7976 if (TREE_CODE (t) == TEMPLATE_DECL)
7977 --processing_template_decl;
7978 if (TREE_CODE (r) == VAR_DECL)
7982 [t]he initialization (and any associated
7983 side-effects) of a static data member does
7984 not occur unless the static data member is
7985 itself used in a way that requires the
7986 definition of the static data member to
7989 Therefore, we do not substitute into the
7990 initialized for the static data member here. */
7991 finish_static_data_member_decl
7994 /*init_const_expr_p=*/false,
7995 /*asmspec_tree=*/NULL_TREE,
7997 if (DECL_INITIALIZED_IN_CLASS_P (r))
7998 check_static_variable_definition (r, TREE_TYPE (r));
8000 else if (TREE_CODE (r) == FIELD_DECL)
8002 /* Determine whether R has a valid type and can be
8003 completed later. If R is invalid, then it is
8004 replaced by error_mark_node so that it will not be
8005 added to TYPE_FIELDS. */
8006 tree rtype = TREE_TYPE (r);
8007 if (can_complete_type_without_circularity (rtype))
8008 complete_type (rtype);
8010 if (!COMPLETE_TYPE_P (rtype))
8012 cxx_incomplete_type_error (r, rtype);
8013 r = error_mark_node;
8017 /* If it is a TYPE_DECL for a class-scoped ENUMERAL_TYPE,
8018 such a thing will already have been added to the field
8019 list by tsubst_enum in finish_member_declaration in the
8020 CLASSTYPE_NESTED_UTDS case above. */
8021 if (!(TREE_CODE (r) == TYPE_DECL
8022 && TREE_CODE (TREE_TYPE (r)) == ENUMERAL_TYPE
8023 && DECL_ARTIFICIAL (r)))
8025 set_current_access_from_decl (r);
8026 finish_member_declaration (r);
8033 if (TYPE_P (t) || DECL_CLASS_TEMPLATE_P (t))
8035 /* Build new CLASSTYPE_FRIEND_CLASSES. */
8037 tree friend_type = t;
8038 bool adjust_processing_template_decl = false;
8040 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
8042 /* template <class T> friend class C; */
8043 friend_type = tsubst_friend_class (friend_type, args);
8044 adjust_processing_template_decl = true;
8046 else if (TREE_CODE (friend_type) == UNBOUND_CLASS_TEMPLATE)
8048 /* template <class T> friend class C::D; */
8049 friend_type = tsubst (friend_type, args,
8050 tf_warning_or_error, NULL_TREE);
8051 if (TREE_CODE (friend_type) == TEMPLATE_DECL)
8052 friend_type = TREE_TYPE (friend_type);
8053 adjust_processing_template_decl = true;
8055 else if (TREE_CODE (friend_type) == TYPENAME_TYPE)
8057 /* This could be either
8061 when dependent_type_p is false or
8063 template <class U> friend class T::C;
8066 friend_type = tsubst (friend_type, args,
8067 tf_warning_or_error, NULL_TREE);
8068 /* Bump processing_template_decl for correct
8069 dependent_type_p calculation. */
8070 ++processing_template_decl;
8071 if (dependent_type_p (friend_type))
8072 adjust_processing_template_decl = true;
8073 --processing_template_decl;
8075 else if (!CLASSTYPE_USE_TEMPLATE (friend_type)
8076 && hidden_name_p (TYPE_NAME (friend_type)))
8080 where C hasn't been declared yet. Let's lookup name
8081 from namespace scope directly, bypassing any name that
8082 come from dependent base class. */
8083 tree ns = decl_namespace_context (TYPE_MAIN_DECL (friend_type));
8085 /* The call to xref_tag_from_type does injection for friend
8087 push_nested_namespace (ns);
8089 xref_tag_from_type (friend_type, NULL_TREE,
8090 /*tag_scope=*/ts_current);
8091 pop_nested_namespace (ns);
8093 else if (uses_template_parms (friend_type))
8094 /* friend class C<T>; */
8095 friend_type = tsubst (friend_type, args,
8096 tf_warning_or_error, NULL_TREE);
8101 where C is already declared or
8103 friend class C<int>;
8105 We don't have to do anything in these cases. */
8107 if (adjust_processing_template_decl)
8108 /* Trick make_friend_class into realizing that the friend
8109 we're adding is a template, not an ordinary class. It's
8110 important that we use make_friend_class since it will
8111 perform some error-checking and output cross-reference
8113 ++processing_template_decl;
8115 if (friend_type != error_mark_node)
8116 make_friend_class (type, friend_type, /*complain=*/false);
8118 if (adjust_processing_template_decl)
8119 --processing_template_decl;
8123 /* Build new DECL_FRIENDLIST. */
8126 /* The file and line for this declaration, to
8127 assist in error message reporting. Since we
8128 called push_tinst_level above, we don't need to
8130 input_location = DECL_SOURCE_LOCATION (t);
8132 if (TREE_CODE (t) == TEMPLATE_DECL)
8134 ++processing_template_decl;
8135 push_deferring_access_checks (dk_no_check);
8138 r = tsubst_friend_function (t, args);
8139 add_friend (type, r, /*complain=*/false);
8140 if (TREE_CODE (t) == TEMPLATE_DECL)
8142 pop_deferring_access_checks ();
8143 --processing_template_decl;
8149 /* Set the file and line number information to whatever is given for
8150 the class itself. This puts error messages involving generated
8151 implicit functions at a predictable point, and the same point
8152 that would be used for non-template classes. */
8153 input_location = DECL_SOURCE_LOCATION (typedecl);
8155 unreverse_member_declarations (type);
8156 finish_struct_1 (type);
8157 TYPE_BEING_DEFINED (type) = 0;
8159 /* Now that the class is complete, instantiate default arguments for
8160 any member functions. We don't do this earlier because the
8161 default arguments may reference members of the class. */
8162 if (!PRIMARY_TEMPLATE_P (templ))
8163 for (t = TYPE_METHODS (type); t; t = TREE_CHAIN (t))
8164 if (TREE_CODE (t) == FUNCTION_DECL
8165 /* Implicitly generated member functions will not have template
8166 information; they are not instantiations, but instead are
8167 created "fresh" for each instantiation. */
8168 && DECL_TEMPLATE_INFO (t))
8169 tsubst_default_arguments (t);
8171 /* Some typedefs referenced from within the template code need to be access
8172 checked at template instantiation time, i.e now. These types were
8173 added to the template at parsing time. Let's get those and perform
8174 the access checks then. */
8175 perform_typedefs_access_check (pattern, args);
8176 perform_deferred_access_checks ();
8177 pop_nested_class ();
8178 maximum_field_alignment = saved_maximum_field_alignment;
8179 pop_from_top_level ();
8180 pop_deferring_access_checks ();
8183 /* The vtable for a template class can be emitted in any translation
8184 unit in which the class is instantiated. When there is no key
8185 method, however, finish_struct_1 will already have added TYPE to
8186 the keyed_classes list. */
8187 if (TYPE_CONTAINS_VPTR_P (type) && CLASSTYPE_KEY_METHOD (type))
8188 keyed_classes = tree_cons (NULL_TREE, type, keyed_classes);
8194 tsubst_template_arg (tree t, tree args, tsubst_flags_t complain, tree in_decl)
8200 else if (TYPE_P (t))
8201 r = tsubst (t, args, complain, in_decl);
8204 r = tsubst_expr (t, args, complain, in_decl,
8205 /*integral_constant_expression_p=*/true);
8206 r = fold_non_dependent_expr (r);
8211 /* Give a chain SPEC_PARM of PARM_DECLs, pack them into a
8212 NONTYPE_ARGUMENT_PACK. */
8215 make_fnparm_pack (tree spec_parm)
8217 /* Collect all of the extra "packed" parameters into an
8221 tree argpack = make_node (NONTYPE_ARGUMENT_PACK);
8222 tree argtypepack = cxx_make_type (TYPE_ARGUMENT_PACK);
8223 int i, len = list_length (spec_parm);
8225 /* Fill in PARMVEC and PARMTYPEVEC with all of the parameters. */
8226 parmvec = make_tree_vec (len);
8227 parmtypevec = make_tree_vec (len);
8228 for (i = 0; i < len; i++, spec_parm = TREE_CHAIN (spec_parm))
8230 TREE_VEC_ELT (parmvec, i) = spec_parm;
8231 TREE_VEC_ELT (parmtypevec, i) = TREE_TYPE (spec_parm);
8234 /* Build the argument packs. */
8235 SET_ARGUMENT_PACK_ARGS (argpack, parmvec);
8236 SET_ARGUMENT_PACK_ARGS (argtypepack, parmtypevec);
8237 TREE_TYPE (argpack) = argtypepack;
8242 /* Substitute ARGS into T, which is an pack expansion
8243 (i.e. TYPE_PACK_EXPANSION or EXPR_PACK_EXPANSION). Returns a
8244 TREE_VEC with the substituted arguments, a PACK_EXPANSION_* node
8245 (if only a partial substitution could be performed) or
8246 ERROR_MARK_NODE if there was an error. */
8248 tsubst_pack_expansion (tree t, tree args, tsubst_flags_t complain,
8252 tree pack, packs = NULL_TREE, unsubstituted_packs = NULL_TREE;
8256 bool very_local_specializations = false;
8258 gcc_assert (PACK_EXPANSION_P (t));
8259 pattern = PACK_EXPANSION_PATTERN (t);
8261 /* Determine the argument packs that will instantiate the parameter
8262 packs used in the expansion expression. While we're at it,
8263 compute the number of arguments to be expanded and make sure it
8265 for (pack = PACK_EXPANSION_PARAMETER_PACKS (t); pack;
8266 pack = TREE_CHAIN (pack))
8268 tree parm_pack = TREE_VALUE (pack);
8269 tree arg_pack = NULL_TREE;
8270 tree orig_arg = NULL_TREE;
8272 if (TREE_CODE (parm_pack) == PARM_DECL)
8274 arg_pack = retrieve_local_specialization (parm_pack);
8275 if (arg_pack == NULL_TREE)
8277 /* This can happen for a parameter name used later in a function
8278 declaration (such as in a late-specified return type). Just
8279 make a dummy decl, since it's only used for its type. */
8280 gcc_assert (cp_unevaluated_operand != 0);
8281 arg_pack = tsubst_decl (parm_pack, args, complain);
8282 arg_pack = make_fnparm_pack (arg_pack);
8287 int level, idx, levels;
8288 template_parm_level_and_index (parm_pack, &level, &idx);
8290 levels = TMPL_ARGS_DEPTH (args);
8291 if (level <= levels)
8292 arg_pack = TMPL_ARG (args, level, idx);
8295 orig_arg = arg_pack;
8296 if (arg_pack && TREE_CODE (arg_pack) == ARGUMENT_PACK_SELECT)
8297 arg_pack = ARGUMENT_PACK_SELECT_FROM_PACK (arg_pack);
8299 if (arg_pack && !ARGUMENT_PACK_P (arg_pack))
8300 /* This can only happen if we forget to expand an argument
8301 pack somewhere else. Just return an error, silently. */
8303 result = make_tree_vec (1);
8304 TREE_VEC_ELT (result, 0) = error_mark_node;
8309 && TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack)) == 1
8310 && PACK_EXPANSION_P (TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0)))
8312 tree expansion = TREE_VEC_ELT (ARGUMENT_PACK_ARGS (arg_pack), 0);
8313 tree pattern = PACK_EXPANSION_PATTERN (expansion);
8314 if ((TYPE_P (pattern) && same_type_p (pattern, parm_pack))
8315 || (!TYPE_P (pattern) && cp_tree_equal (parm_pack, pattern)))
8316 /* The argument pack that the parameter maps to is just an
8317 expansion of the parameter itself, such as one would
8318 find in the implicit typedef of a class inside the
8319 class itself. Consider this parameter "unsubstituted",
8320 so that we will maintain the outer pack expansion. */
8321 arg_pack = NULL_TREE;
8327 TREE_VEC_LENGTH (ARGUMENT_PACK_ARGS (arg_pack));
8329 /* It's all-or-nothing with incomplete argument packs. */
8330 if (incomplete && !ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
8331 return error_mark_node;
8333 if (ARGUMENT_PACK_INCOMPLETE_P (arg_pack))
8338 else if (len != my_len)
8341 /* We got explicit args for some packs but not others;
8342 do nothing now and try again after deduction. */
8344 if (TREE_CODE (t) == TYPE_PACK_EXPANSION)
8345 error ("mismatched argument pack lengths while expanding "
8349 error ("mismatched argument pack lengths while expanding "
8352 return error_mark_node;
8355 /* Keep track of the parameter packs and their corresponding
8357 packs = tree_cons (parm_pack, arg_pack, packs);
8358 TREE_TYPE (packs) = orig_arg;
8361 /* We can't substitute for this parameter pack. */
8362 unsubstituted_packs = tree_cons (TREE_PURPOSE (pack),
8364 unsubstituted_packs);
8367 /* We cannot expand this expansion expression, because we don't have
8368 all of the argument packs we need. Substitute into the pattern
8369 and return a PACK_EXPANSION_*. The caller will need to deal with
8371 if (unsubstituted_packs)
8374 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
8375 new_pat = tsubst_expr (pattern, args, complain, in_decl,
8376 /*integral_constant_expression_p=*/false);
8378 new_pat = tsubst (pattern, args, complain, in_decl);
8379 return make_pack_expansion (new_pat);
8382 /* We could not find any argument packs that work. */
8384 return error_mark_node;
8386 if (!local_specializations)
8388 /* We're in a late-specified return type, so we don't have a local
8389 specializations table. Create one for doing this expansion. */
8390 very_local_specializations = true;
8391 local_specializations = htab_create (37,
8392 hash_local_specialization,
8393 eq_local_specializations,
8397 /* For each argument in each argument pack, substitute into the
8399 result = make_tree_vec (len + incomplete);
8400 for (i = 0; i < len + incomplete; ++i)
8402 /* For parameter pack, change the substitution of the parameter
8403 pack to the ith argument in its argument pack, then expand
8405 for (pack = packs; pack; pack = TREE_CHAIN (pack))
8407 tree parm = TREE_PURPOSE (pack);
8409 if (TREE_CODE (parm) == PARM_DECL)
8411 /* Select the Ith argument from the pack. */
8412 tree arg = make_node (ARGUMENT_PACK_SELECT);
8413 ARGUMENT_PACK_SELECT_FROM_PACK (arg) = TREE_VALUE (pack);
8414 ARGUMENT_PACK_SELECT_INDEX (arg) = i;
8416 register_local_specialization (arg, parm);
8422 template_parm_level_and_index (parm, &level, &idx);
8426 /* Select the Ith argument from the pack. */
8427 value = make_node (ARGUMENT_PACK_SELECT);
8428 ARGUMENT_PACK_SELECT_FROM_PACK (value) = TREE_VALUE (pack);
8429 ARGUMENT_PACK_SELECT_INDEX (value) = i;
8432 /* Update the corresponding argument. */
8433 TMPL_ARG (args, level, idx) = value;
8437 /* Substitute into the PATTERN with the altered arguments. */
8438 if (TREE_CODE (t) == EXPR_PACK_EXPANSION)
8439 TREE_VEC_ELT (result, i) =
8440 tsubst_expr (pattern, args, complain, in_decl,
8441 /*integral_constant_expression_p=*/false);
8443 TREE_VEC_ELT (result, i) = tsubst (pattern, args, complain, in_decl);
8446 /* When we have incomplete argument packs, the last "expanded"
8447 result is itself a pack expansion, which allows us
8448 to deduce more arguments. */
8449 TREE_VEC_ELT (result, i) =
8450 make_pack_expansion (TREE_VEC_ELT (result, i));
8452 if (TREE_VEC_ELT (result, i) == error_mark_node)
8454 result = error_mark_node;
8459 /* Update ARGS to restore the substitution from parameter packs to
8460 their argument packs. */
8461 for (pack = packs; pack; pack = TREE_CHAIN (pack))
8463 tree parm = TREE_PURPOSE (pack);
8465 if (TREE_CODE (parm) == PARM_DECL)
8466 register_local_specialization (TREE_TYPE (pack), parm);
8470 template_parm_level_and_index (parm, &level, &idx);
8472 /* Update the corresponding argument. */
8473 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
8474 TREE_VEC_ELT (TREE_VEC_ELT (args, level -1 ), idx) =
8477 TREE_VEC_ELT (args, idx) = TREE_TYPE (pack);
8481 if (very_local_specializations)
8483 htab_delete (local_specializations);
8484 local_specializations = NULL;
8490 /* Given PARM_DECL PARM, find the corresponding PARM_DECL in the template
8491 TMPL. We do this using DECL_PARM_INDEX, which should work even with
8492 parameter packs; all parms generated from a function parameter pack will
8493 have the same DECL_PARM_INDEX. */
8496 get_pattern_parm (tree parm, tree tmpl)
8498 tree pattern = DECL_TEMPLATE_RESULT (tmpl);
8501 if (DECL_ARTIFICIAL (parm))
8503 for (patparm = DECL_ARGUMENTS (pattern);
8504 patparm; patparm = TREE_CHAIN (patparm))
8505 if (DECL_ARTIFICIAL (patparm)
8506 && DECL_NAME (parm) == DECL_NAME (patparm))
8511 patparm = FUNCTION_FIRST_USER_PARM (DECL_TEMPLATE_RESULT (tmpl));
8512 patparm = chain_index (DECL_PARM_INDEX (parm)-1, patparm);
8513 gcc_assert (DECL_PARM_INDEX (patparm)
8514 == DECL_PARM_INDEX (parm));
8520 /* Substitute ARGS into the vector or list of template arguments T. */
8523 tsubst_template_args (tree t, tree args, tsubst_flags_t complain, tree in_decl)
8526 int len = TREE_VEC_LENGTH (t);
8527 int need_new = 0, i, expanded_len_adjust = 0, out;
8528 tree *elts = (tree *) alloca (len * sizeof (tree));
8530 for (i = 0; i < len; i++)
8532 tree orig_arg = TREE_VEC_ELT (t, i);
8535 if (TREE_CODE (orig_arg) == TREE_VEC)
8536 new_arg = tsubst_template_args (orig_arg, args, complain, in_decl);
8537 else if (PACK_EXPANSION_P (orig_arg))
8539 /* Substitute into an expansion expression. */
8540 new_arg = tsubst_pack_expansion (orig_arg, args, complain, in_decl);
8542 if (TREE_CODE (new_arg) == TREE_VEC)
8543 /* Add to the expanded length adjustment the number of
8544 expanded arguments. We subtract one from this
8545 measurement, because the argument pack expression
8546 itself is already counted as 1 in
8547 LEN. EXPANDED_LEN_ADJUST can actually be negative, if
8548 the argument pack is empty. */
8549 expanded_len_adjust += TREE_VEC_LENGTH (new_arg) - 1;
8551 else if (ARGUMENT_PACK_P (orig_arg))
8553 /* Substitute into each of the arguments. */
8554 new_arg = TYPE_P (orig_arg)
8555 ? cxx_make_type (TREE_CODE (orig_arg))
8556 : make_node (TREE_CODE (orig_arg));
8558 SET_ARGUMENT_PACK_ARGS (
8560 tsubst_template_args (ARGUMENT_PACK_ARGS (orig_arg),
8561 args, complain, in_decl));
8563 if (ARGUMENT_PACK_ARGS (new_arg) == error_mark_node)
8564 new_arg = error_mark_node;
8566 if (TREE_CODE (new_arg) == NONTYPE_ARGUMENT_PACK) {
8567 TREE_TYPE (new_arg) = tsubst (TREE_TYPE (orig_arg), args,
8569 TREE_CONSTANT (new_arg) = TREE_CONSTANT (orig_arg);
8571 if (TREE_TYPE (new_arg) == error_mark_node)
8572 new_arg = error_mark_node;
8576 new_arg = tsubst_template_arg (orig_arg, args, complain, in_decl);
8578 if (new_arg == error_mark_node)
8579 return error_mark_node;
8582 if (new_arg != orig_arg)
8589 /* Make space for the expanded arguments coming from template
8591 t = make_tree_vec (len + expanded_len_adjust);
8592 /* ORIG_T can contain TREE_VECs. That happens if ORIG_T contains the
8593 arguments for a member template.
8594 In that case each TREE_VEC in ORIG_T represents a level of template
8595 arguments, and ORIG_T won't carry any non defaulted argument count.
8596 It will rather be the nested TREE_VECs that will carry one.
8597 In other words, ORIG_T carries a non defaulted argument count only
8598 if it doesn't contain any nested TREE_VEC. */
8599 if (NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t))
8601 int count = GET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (orig_t);
8602 count += expanded_len_adjust;
8603 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (t, count);
8605 for (i = 0, out = 0; i < len; i++)
8607 if ((PACK_EXPANSION_P (TREE_VEC_ELT (orig_t, i))
8608 || ARGUMENT_PACK_P (TREE_VEC_ELT (orig_t, i)))
8609 && TREE_CODE (elts[i]) == TREE_VEC)
8613 /* Now expand the template argument pack "in place". */
8614 for (idx = 0; idx < TREE_VEC_LENGTH (elts[i]); idx++, out++)
8615 TREE_VEC_ELT (t, out) = TREE_VEC_ELT (elts[i], idx);
8619 TREE_VEC_ELT (t, out) = elts[i];
8627 /* Return the result of substituting ARGS into the template parameters
8628 given by PARMS. If there are m levels of ARGS and m + n levels of
8629 PARMS, then the result will contain n levels of PARMS. For
8630 example, if PARMS is `template <class T> template <class U>
8631 template <T*, U, class V>' and ARGS is {{int}, {double}} then the
8632 result will be `template <int*, double, class V>'. */
8635 tsubst_template_parms (tree parms, tree args, tsubst_flags_t complain)
8640 /* When substituting into a template, we must set
8641 PROCESSING_TEMPLATE_DECL as the template parameters may be
8642 dependent if they are based on one-another, and the dependency
8643 predicates are short-circuit outside of templates. */
8644 ++processing_template_decl;
8646 for (new_parms = &r;
8647 TMPL_PARMS_DEPTH (parms) > TMPL_ARGS_DEPTH (args);
8648 new_parms = &(TREE_CHAIN (*new_parms)),
8649 parms = TREE_CHAIN (parms))
8652 make_tree_vec (TREE_VEC_LENGTH (TREE_VALUE (parms)));
8655 for (i = 0; i < TREE_VEC_LENGTH (new_vec); ++i)
8661 if (parms == error_mark_node)
8664 tuple = TREE_VEC_ELT (TREE_VALUE (parms), i);
8666 if (tuple == error_mark_node)
8669 default_value = TREE_PURPOSE (tuple);
8670 parm_decl = TREE_VALUE (tuple);
8672 parm_decl = tsubst (parm_decl, args, complain, NULL_TREE);
8673 if (TREE_CODE (parm_decl) == PARM_DECL
8674 && invalid_nontype_parm_type_p (TREE_TYPE (parm_decl), complain))
8675 parm_decl = error_mark_node;
8676 default_value = tsubst_template_arg (default_value, args,
8677 complain, NULL_TREE);
8679 tuple = build_tree_list (default_value, parm_decl);
8680 TREE_VEC_ELT (new_vec, i) = tuple;
8684 tree_cons (size_int (TMPL_PARMS_DEPTH (parms)
8685 - TMPL_ARGS_DEPTH (args)),
8686 new_vec, NULL_TREE);
8689 --processing_template_decl;
8694 /* Substitute the ARGS into the indicated aggregate (or enumeration)
8695 type T. If T is not an aggregate or enumeration type, it is
8696 handled as if by tsubst. IN_DECL is as for tsubst. If
8697 ENTERING_SCOPE is nonzero, T is the context for a template which
8698 we are presently tsubst'ing. Return the substituted value. */
8701 tsubst_aggr_type (tree t,
8703 tsubst_flags_t complain,
8710 switch (TREE_CODE (t))
8713 if (TYPE_PTRMEMFUNC_P (t))
8714 return tsubst (TYPE_PTRMEMFUNC_FN_TYPE (t), args, complain, in_decl);
8716 /* Else fall through. */
8719 if (TYPE_TEMPLATE_INFO (t) && uses_template_parms (t))
8724 int saved_unevaluated_operand;
8725 int saved_inhibit_evaluation_warnings;
8727 /* In "sizeof(X<I>)" we need to evaluate "I". */
8728 saved_unevaluated_operand = cp_unevaluated_operand;
8729 cp_unevaluated_operand = 0;
8730 saved_inhibit_evaluation_warnings = c_inhibit_evaluation_warnings;
8731 c_inhibit_evaluation_warnings = 0;
8733 /* First, determine the context for the type we are looking
8735 context = TYPE_CONTEXT (t);
8738 context = tsubst_aggr_type (context, args, complain,
8739 in_decl, /*entering_scope=*/1);
8740 /* If context is a nested class inside a class template,
8741 it may still need to be instantiated (c++/33959). */
8742 if (TYPE_P (context))
8743 context = complete_type (context);
8746 /* Then, figure out what arguments are appropriate for the
8747 type we are trying to find. For example, given:
8749 template <class T> struct S;
8750 template <class T, class U> void f(T, U) { S<U> su; }
8752 and supposing that we are instantiating f<int, double>,
8753 then our ARGS will be {int, double}, but, when looking up
8754 S we only want {double}. */
8755 argvec = tsubst_template_args (TYPE_TI_ARGS (t), args,
8757 if (argvec == error_mark_node)
8758 r = error_mark_node;
8761 r = lookup_template_class (t, argvec, in_decl, context,
8762 entering_scope, complain);
8763 r = cp_build_qualified_type_real (r, TYPE_QUALS (t), complain);
8766 cp_unevaluated_operand = saved_unevaluated_operand;
8767 c_inhibit_evaluation_warnings = saved_inhibit_evaluation_warnings;
8772 /* This is not a template type, so there's nothing to do. */
8776 return tsubst (t, args, complain, in_decl);
8780 /* Substitute into the default argument ARG (a default argument for
8781 FN), which has the indicated TYPE. */
8784 tsubst_default_argument (tree fn, tree type, tree arg)
8786 tree saved_class_ptr = NULL_TREE;
8787 tree saved_class_ref = NULL_TREE;
8789 /* This default argument came from a template. Instantiate the
8790 default argument here, not in tsubst. In the case of
8799 we must be careful to do name lookup in the scope of S<T>,
8800 rather than in the current class. */
8801 push_access_scope (fn);
8802 /* The "this" pointer is not valid in a default argument. */
8805 saved_class_ptr = current_class_ptr;
8806 cp_function_chain->x_current_class_ptr = NULL_TREE;
8807 saved_class_ref = current_class_ref;
8808 cp_function_chain->x_current_class_ref = NULL_TREE;
8811 push_deferring_access_checks(dk_no_deferred);
8812 /* The default argument expression may cause implicitly defined
8813 member functions to be synthesized, which will result in garbage
8814 collection. We must treat this situation as if we were within
8815 the body of function so as to avoid collecting live data on the
8818 arg = tsubst_expr (arg, DECL_TI_ARGS (fn),
8819 tf_warning_or_error, NULL_TREE,
8820 /*integral_constant_expression_p=*/false);
8822 pop_deferring_access_checks();
8824 /* Restore the "this" pointer. */
8827 cp_function_chain->x_current_class_ptr = saved_class_ptr;
8828 cp_function_chain->x_current_class_ref = saved_class_ref;
8831 /* Make sure the default argument is reasonable. */
8832 arg = check_default_argument (type, arg);
8834 pop_access_scope (fn);
8839 /* Substitute into all the default arguments for FN. */
8842 tsubst_default_arguments (tree fn)
8847 tmpl_args = DECL_TI_ARGS (fn);
8849 /* If this function is not yet instantiated, we certainly don't need
8850 its default arguments. */
8851 if (uses_template_parms (tmpl_args))
8854 for (arg = TYPE_ARG_TYPES (TREE_TYPE (fn));
8856 arg = TREE_CHAIN (arg))
8857 if (TREE_PURPOSE (arg))
8858 TREE_PURPOSE (arg) = tsubst_default_argument (fn,
8860 TREE_PURPOSE (arg));
8863 /* Substitute the ARGS into the T, which is a _DECL. Return the
8864 result of the substitution. Issue error and warning messages under
8865 control of COMPLAIN. */
8868 tsubst_decl (tree t, tree args, tsubst_flags_t complain)
8870 #define RETURN(EXP) do { r = (EXP); goto out; } while(0)
8871 location_t saved_loc;
8876 /* Set the filename and linenumber to improve error-reporting. */
8877 saved_loc = input_location;
8878 input_location = DECL_SOURCE_LOCATION (t);
8880 switch (TREE_CODE (t))
8884 /* We can get here when processing a member function template,
8885 member class template, or template template parameter. */
8886 tree decl = DECL_TEMPLATE_RESULT (t);
8891 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
8893 /* Template template parameter is treated here. */
8894 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8895 if (new_type == error_mark_node)
8896 RETURN (error_mark_node);
8899 TREE_CHAIN (r) = NULL_TREE;
8900 TREE_TYPE (r) = new_type;
8901 DECL_TEMPLATE_RESULT (r)
8902 = build_decl (DECL_SOURCE_LOCATION (decl),
8903 TYPE_DECL, DECL_NAME (decl), new_type);
8904 DECL_TEMPLATE_PARMS (r)
8905 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
8907 TYPE_NAME (new_type) = r;
8911 /* We might already have an instance of this template.
8912 The ARGS are for the surrounding class type, so the
8913 full args contain the tsubst'd args for the context,
8914 plus the innermost args from the template decl. */
8915 tmpl_args = DECL_CLASS_TEMPLATE_P (t)
8916 ? CLASSTYPE_TI_ARGS (TREE_TYPE (t))
8917 : DECL_TI_ARGS (DECL_TEMPLATE_RESULT (t));
8918 /* Because this is a template, the arguments will still be
8919 dependent, even after substitution. If
8920 PROCESSING_TEMPLATE_DECL is not set, the dependency
8921 predicates will short-circuit. */
8922 ++processing_template_decl;
8923 full_args = tsubst_template_args (tmpl_args, args,
8925 --processing_template_decl;
8926 if (full_args == error_mark_node)
8927 RETURN (error_mark_node);
8929 /* If this is a default template template argument,
8930 tsubst might not have changed anything. */
8931 if (full_args == tmpl_args)
8934 hash = hash_tmpl_and_args (t, full_args);
8935 spec = retrieve_specialization (t, full_args, hash);
8936 if (spec != NULL_TREE)
8942 /* Make a new template decl. It will be similar to the
8943 original, but will record the current template arguments.
8944 We also create a new function declaration, which is just
8945 like the old one, but points to this new template, rather
8946 than the old one. */
8948 gcc_assert (DECL_LANG_SPECIFIC (r) != 0);
8949 TREE_CHAIN (r) = NULL_TREE;
8951 DECL_TEMPLATE_INFO (r) = build_template_info (t, args);
8953 if (TREE_CODE (decl) == TYPE_DECL)
8956 ++processing_template_decl;
8957 new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
8958 --processing_template_decl;
8959 if (new_type == error_mark_node)
8960 RETURN (error_mark_node);
8962 TREE_TYPE (r) = new_type;
8963 CLASSTYPE_TI_TEMPLATE (new_type) = r;
8964 DECL_TEMPLATE_RESULT (r) = TYPE_MAIN_DECL (new_type);
8965 DECL_TI_ARGS (r) = CLASSTYPE_TI_ARGS (new_type);
8966 DECL_CONTEXT (r) = TYPE_CONTEXT (new_type);
8971 ++processing_template_decl;
8972 new_decl = tsubst (decl, args, complain, in_decl);
8973 --processing_template_decl;
8974 if (new_decl == error_mark_node)
8975 RETURN (error_mark_node);
8977 DECL_TEMPLATE_RESULT (r) = new_decl;
8978 DECL_TI_TEMPLATE (new_decl) = r;
8979 TREE_TYPE (r) = TREE_TYPE (new_decl);
8980 DECL_TI_ARGS (r) = DECL_TI_ARGS (new_decl);
8981 DECL_CONTEXT (r) = DECL_CONTEXT (new_decl);
8984 SET_DECL_IMPLICIT_INSTANTIATION (r);
8985 DECL_TEMPLATE_INSTANTIATIONS (r) = NULL_TREE;
8986 DECL_TEMPLATE_SPECIALIZATIONS (r) = NULL_TREE;
8988 /* The template parameters for this new template are all the
8989 template parameters for the old template, except the
8990 outermost level of parameters. */
8991 DECL_TEMPLATE_PARMS (r)
8992 = tsubst_template_parms (DECL_TEMPLATE_PARMS (t), args,
8995 if (PRIMARY_TEMPLATE_P (t))
8996 DECL_PRIMARY_TEMPLATE (r) = r;
8998 if (TREE_CODE (decl) != TYPE_DECL)
8999 /* Record this non-type partial instantiation. */
9000 register_specialization (r, t,
9001 DECL_TI_ARGS (DECL_TEMPLATE_RESULT (r)),
9009 tree argvec = NULL_TREE;
9017 /* Nobody should be tsubst'ing into non-template functions. */
9018 gcc_assert (DECL_TEMPLATE_INFO (t) != NULL_TREE);
9020 if (TREE_CODE (DECL_TI_TEMPLATE (t)) == TEMPLATE_DECL)
9025 /* If T is not dependent, just return it. We have to
9026 increment PROCESSING_TEMPLATE_DECL because
9027 value_dependent_expression_p assumes that nothing is
9028 dependent when PROCESSING_TEMPLATE_DECL is zero. */
9029 ++processing_template_decl;
9030 dependent_p = value_dependent_expression_p (t);
9031 --processing_template_decl;
9035 /* Calculate the most general template of which R is a
9036 specialization, and the complete set of arguments used to
9038 gen_tmpl = most_general_template (DECL_TI_TEMPLATE (t));
9039 argvec = tsubst_template_args (DECL_TI_ARGS
9040 (DECL_TEMPLATE_RESULT
9041 (DECL_TI_TEMPLATE (t))),
9042 args, complain, in_decl);
9044 /* Check to see if we already have this specialization. */
9045 hash = hash_tmpl_and_args (gen_tmpl, argvec);
9046 spec = retrieve_specialization (gen_tmpl, argvec, hash);
9054 /* We can see more levels of arguments than parameters if
9055 there was a specialization of a member template, like
9058 template <class T> struct S { template <class U> void f(); }
9059 template <> template <class U> void S<int>::f(U);
9061 Here, we'll be substituting into the specialization,
9062 because that's where we can find the code we actually
9063 want to generate, but we'll have enough arguments for
9064 the most general template.
9066 We also deal with the peculiar case:
9068 template <class T> struct S {
9069 template <class U> friend void f();
9071 template <class U> void f() {}
9073 template void f<double>();
9075 Here, the ARGS for the instantiation of will be {int,
9076 double}. But, we only need as many ARGS as there are
9077 levels of template parameters in CODE_PATTERN. We are
9078 careful not to get fooled into reducing the ARGS in
9081 template <class T> struct S { template <class U> void f(U); }
9082 template <class T> template <> void S<T>::f(int) {}
9084 which we can spot because the pattern will be a
9085 specialization in this case. */
9086 args_depth = TMPL_ARGS_DEPTH (args);
9088 TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (DECL_TI_TEMPLATE (t)));
9089 if (args_depth > parms_depth
9090 && !DECL_TEMPLATE_SPECIALIZATION (t))
9091 args = get_innermost_template_args (args, parms_depth);
9095 /* This special case arises when we have something like this:
9097 template <class T> struct S {
9098 friend void f<int>(int, double);
9101 Here, the DECL_TI_TEMPLATE for the friend declaration
9102 will be an IDENTIFIER_NODE. We are being called from
9103 tsubst_friend_function, and we want only to create a
9104 new decl (R) with appropriate types so that we can call
9105 determine_specialization. */
9106 gen_tmpl = NULL_TREE;
9109 if (DECL_CLASS_SCOPE_P (t))
9111 if (DECL_NAME (t) == constructor_name (DECL_CONTEXT (t)))
9115 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args,
9116 complain, t, /*entering_scope=*/1);
9121 ctx = DECL_CONTEXT (t);
9123 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9124 if (type == error_mark_node)
9125 RETURN (error_mark_node);
9127 /* We do NOT check for matching decls pushed separately at this
9128 point, as they may not represent instantiations of this
9129 template, and in any case are considered separate under the
9132 DECL_USE_TEMPLATE (r) = 0;
9133 TREE_TYPE (r) = type;
9134 /* Clear out the mangled name and RTL for the instantiation. */
9135 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
9136 SET_DECL_RTL (r, NULL_RTX);
9137 /* Leave DECL_INITIAL set on deleted instantiations. */
9138 if (!DECL_DELETED_FN (r))
9139 DECL_INITIAL (r) = NULL_TREE;
9140 DECL_CONTEXT (r) = ctx;
9142 if (member && DECL_CONV_FN_P (r))
9143 /* Type-conversion operator. Reconstruct the name, in
9144 case it's the name of one of the template's parameters. */
9145 DECL_NAME (r) = mangle_conv_op_name_for_type (TREE_TYPE (type));
9147 DECL_ARGUMENTS (r) = tsubst (DECL_ARGUMENTS (t), args,
9149 DECL_RESULT (r) = NULL_TREE;
9151 TREE_STATIC (r) = 0;
9152 TREE_PUBLIC (r) = TREE_PUBLIC (t);
9153 DECL_EXTERNAL (r) = 1;
9154 /* If this is an instantiation of a function with internal
9155 linkage, we already know what object file linkage will be
9156 assigned to the instantiation. */
9157 DECL_INTERFACE_KNOWN (r) = !TREE_PUBLIC (r);
9158 DECL_DEFER_OUTPUT (r) = 0;
9159 TREE_CHAIN (r) = NULL_TREE;
9160 DECL_PENDING_INLINE_INFO (r) = 0;
9161 DECL_PENDING_INLINE_P (r) = 0;
9162 DECL_SAVED_TREE (r) = NULL_TREE;
9163 DECL_STRUCT_FUNCTION (r) = NULL;
9165 /* We'll re-clone as appropriate in instantiate_template. */
9166 DECL_CLONED_FUNCTION (r) = NULL_TREE;
9168 /* If we aren't complaining now, return on error before we register
9169 the specialization so that we'll complain eventually. */
9170 if ((complain & tf_error) == 0
9171 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
9172 && !grok_op_properties (r, /*complain=*/false))
9173 RETURN (error_mark_node);
9175 /* Set up the DECL_TEMPLATE_INFO for R. There's no need to do
9176 this in the special friend case mentioned above where
9177 GEN_TMPL is NULL. */
9180 DECL_TEMPLATE_INFO (r)
9181 = build_template_info (gen_tmpl, argvec);
9182 SET_DECL_IMPLICIT_INSTANTIATION (r);
9183 register_specialization (r, gen_tmpl, argvec, false, hash);
9185 /* We're not supposed to instantiate default arguments
9186 until they are called, for a template. But, for a
9189 template <class T> void f ()
9190 { extern void g(int i = T()); }
9192 we should do the substitution when the template is
9193 instantiated. We handle the member function case in
9194 instantiate_class_template since the default arguments
9195 might refer to other members of the class. */
9197 && !PRIMARY_TEMPLATE_P (gen_tmpl)
9198 && !uses_template_parms (argvec))
9199 tsubst_default_arguments (r);
9202 DECL_TEMPLATE_INFO (r) = NULL_TREE;
9204 /* Copy the list of befriending classes. */
9205 for (friends = &DECL_BEFRIENDING_CLASSES (r);
9207 friends = &TREE_CHAIN (*friends))
9209 *friends = copy_node (*friends);
9210 TREE_VALUE (*friends) = tsubst (TREE_VALUE (*friends),
9215 if (DECL_CONSTRUCTOR_P (r) || DECL_DESTRUCTOR_P (r))
9217 maybe_retrofit_in_chrg (r);
9218 if (DECL_CONSTRUCTOR_P (r))
9219 grok_ctor_properties (ctx, r);
9220 /* If this is an instantiation of a member template, clone it.
9221 If it isn't, that'll be handled by
9222 clone_constructors_and_destructors. */
9223 if (PRIMARY_TEMPLATE_P (gen_tmpl))
9224 clone_function_decl (r, /*update_method_vec_p=*/0);
9226 else if ((complain & tf_error) != 0
9227 && IDENTIFIER_OPNAME_P (DECL_NAME (r))
9228 && !grok_op_properties (r, /*complain=*/true))
9229 RETURN (error_mark_node);
9231 if (DECL_FRIEND_P (t) && DECL_FRIEND_CONTEXT (t))
9232 SET_DECL_FRIEND_CONTEXT (r,
9233 tsubst (DECL_FRIEND_CONTEXT (t),
9234 args, complain, in_decl));
9236 /* Possibly limit visibility based on template args. */
9237 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
9238 if (DECL_VISIBILITY_SPECIFIED (t))
9240 DECL_VISIBILITY_SPECIFIED (r) = 0;
9242 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
9244 determine_visibility (r);
9245 if (DECL_DEFAULTED_OUTSIDE_CLASS_P (r)
9246 && !processing_template_decl)
9247 defaulted_late_check (r);
9249 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
9250 args, complain, in_decl);
9256 tree type = NULL_TREE;
9258 tree expanded_types = NULL_TREE;
9259 tree prev_r = NULL_TREE;
9260 tree first_r = NULL_TREE;
9262 if (FUNCTION_PARAMETER_PACK_P (t))
9264 /* If there is a local specialization that isn't a
9265 parameter pack, it means that we're doing a "simple"
9266 substitution from inside tsubst_pack_expansion. Just
9267 return the local specialization (which will be a single
9269 tree spec = retrieve_local_specialization (t);
9271 && TREE_CODE (spec) == PARM_DECL
9272 && TREE_CODE (TREE_TYPE (spec)) != TYPE_PACK_EXPANSION)
9275 /* Expand the TYPE_PACK_EXPANSION that provides the types for
9276 the parameters in this function parameter pack. */
9277 expanded_types = tsubst_pack_expansion (TREE_TYPE (t), args,
9279 if (TREE_CODE (expanded_types) == TREE_VEC)
9281 len = TREE_VEC_LENGTH (expanded_types);
9283 /* Zero-length parameter packs are boring. Just substitute
9286 RETURN (tsubst (TREE_CHAIN (t), args, complain,
9291 /* All we did was update the type. Make a note of that. */
9292 type = expanded_types;
9293 expanded_types = NULL_TREE;
9297 /* Loop through all of the parameter's we'll build. When T is
9298 a function parameter pack, LEN is the number of expanded
9299 types in EXPANDED_TYPES; otherwise, LEN is 1. */
9301 for (i = 0; i < len; ++i)
9305 if (DECL_TEMPLATE_PARM_P (t))
9306 SET_DECL_TEMPLATE_PARM_P (r);
9308 /* An argument of a function parameter pack is not a parameter
9310 FUNCTION_PARAMETER_PACK_P (r) = false;
9313 /* We're on the Ith parameter of the function parameter
9316 /* Get the Ith type. */
9317 type = TREE_VEC_ELT (expanded_types, i);
9320 /* Rename the parameter to include the index. */
9322 make_ith_pack_parameter_name (DECL_NAME (r), i);
9325 /* We're dealing with a normal parameter. */
9326 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9328 type = type_decays_to (type);
9329 TREE_TYPE (r) = type;
9330 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
9332 if (DECL_INITIAL (r))
9334 if (TREE_CODE (DECL_INITIAL (r)) != TEMPLATE_PARM_INDEX)
9335 DECL_INITIAL (r) = TREE_TYPE (r);
9337 DECL_INITIAL (r) = tsubst (DECL_INITIAL (r), args,
9341 DECL_CONTEXT (r) = NULL_TREE;
9343 if (!DECL_TEMPLATE_PARM_P (r))
9344 DECL_ARG_TYPE (r) = type_passed_as (type);
9346 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
9347 args, complain, in_decl);
9349 /* Keep track of the first new parameter we
9350 generate. That's what will be returned to the
9355 /* Build a proper chain of parameters when substituting
9356 into a function parameter pack. */
9358 TREE_CHAIN (prev_r) = r;
9362 TREE_CHAIN (r) = tsubst (TREE_CHAIN (t), args,
9363 complain, TREE_CHAIN (t));
9365 /* FIRST_R contains the start of the chain we've built. */
9375 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9376 if (type == error_mark_node)
9377 RETURN (error_mark_node);
9378 TREE_TYPE (r) = type;
9379 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
9381 /* DECL_INITIAL gives the number of bits in a bit-field. */
9383 = tsubst_expr (DECL_INITIAL (t), args,
9385 /*integral_constant_expression_p=*/true);
9386 /* We don't have to set DECL_CONTEXT here; it is set by
9387 finish_member_declaration. */
9388 TREE_CHAIN (r) = NULL_TREE;
9389 if (VOID_TYPE_P (type))
9390 error ("instantiation of %q+D as type %qT", r, type);
9392 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r), 0,
9393 args, complain, in_decl);
9398 /* We reach here only for member using decls. */
9399 if (DECL_DEPENDENT_P (t))
9401 r = do_class_using_decl
9402 (tsubst_copy (USING_DECL_SCOPE (t), args, complain, in_decl),
9403 tsubst_copy (DECL_NAME (t), args, complain, in_decl));
9405 r = error_mark_node;
9408 TREE_PROTECTED (r) = TREE_PROTECTED (t);
9409 TREE_PRIVATE (r) = TREE_PRIVATE (t);
9415 TREE_CHAIN (r) = NULL_TREE;
9422 tree argvec = NULL_TREE;
9423 tree gen_tmpl = NULL_TREE;
9425 tree tmpl = NULL_TREE;
9427 tree type = NULL_TREE;
9430 if (TREE_CODE (t) == TYPE_DECL
9431 && t == TYPE_MAIN_DECL (TREE_TYPE (t)))
9433 /* If this is the canonical decl, we don't have to
9434 mess with instantiations, and often we can't (for
9435 typename, template type parms and such). Note that
9436 TYPE_NAME is not correct for the above test if
9437 we've copied the type for a typedef. */
9438 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9439 if (type == error_mark_node)
9440 RETURN (error_mark_node);
9441 r = TYPE_NAME (type);
9445 /* Check to see if we already have the specialization we
9448 if (DECL_CLASS_SCOPE_P (t) || DECL_NAMESPACE_SCOPE_P (t))
9450 /* T is a static data member or namespace-scope entity.
9451 We have to substitute into namespace-scope variables
9452 (even though such entities are never templates) because
9455 template <class T> void f() { extern T t; }
9457 where the entity referenced is not known until
9458 instantiation time. */
9460 ctx = DECL_CONTEXT (t);
9461 if (DECL_CLASS_SCOPE_P (t))
9463 ctx = tsubst_aggr_type (ctx, args,
9465 in_decl, /*entering_scope=*/1);
9466 /* If CTX is unchanged, then T is in fact the
9467 specialization we want. That situation occurs when
9468 referencing a static data member within in its own
9469 class. We can use pointer equality, rather than
9470 same_type_p, because DECL_CONTEXT is always
9472 if (ctx == DECL_CONTEXT (t))
9478 tmpl = DECL_TI_TEMPLATE (t);
9479 gen_tmpl = most_general_template (tmpl);
9480 argvec = tsubst (DECL_TI_ARGS (t), args, complain, in_decl);
9481 hash = hash_tmpl_and_args (gen_tmpl, argvec);
9482 spec = retrieve_specialization (gen_tmpl, argvec, hash);
9487 /* A local variable. */
9489 /* Subsequent calls to pushdecl will fill this in. */
9491 spec = retrieve_local_specialization (t);
9493 /* If we already have the specialization we need, there is
9494 nothing more to do. */
9501 /* Create a new node for the specialization we need. */
9503 if (type == NULL_TREE)
9505 if (is_typedef_decl (t))
9506 type = DECL_ORIGINAL_TYPE (t);
9508 type = TREE_TYPE (t);
9509 if (TREE_CODE (t) == VAR_DECL && VAR_HAD_UNKNOWN_BOUND (t))
9510 type = strip_array_domain (type);
9511 type = tsubst (type, args, complain, in_decl);
9513 if (TREE_CODE (r) == VAR_DECL)
9515 /* Even if the original location is out of scope, the
9516 newly substituted one is not. */
9517 DECL_DEAD_FOR_LOCAL (r) = 0;
9518 DECL_INITIALIZED_P (r) = 0;
9519 DECL_TEMPLATE_INSTANTIATED (r) = 0;
9520 if (type == error_mark_node)
9521 RETURN (error_mark_node);
9522 if (TREE_CODE (type) == FUNCTION_TYPE)
9524 /* It may seem that this case cannot occur, since:
9529 declares a function, not a variable. However:
9532 template <typename T> void g() { T t; }
9533 template void g<f>();
9535 is an attempt to declare a variable with function
9537 error ("variable %qD has function type",
9538 /* R is not yet sufficiently initialized, so we
9539 just use its name. */
9541 RETURN (error_mark_node);
9543 type = complete_type (type);
9544 DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (r)
9545 = DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (t);
9546 type = check_var_type (DECL_NAME (r), type);
9548 if (DECL_HAS_VALUE_EXPR_P (t))
9550 tree ve = DECL_VALUE_EXPR (t);
9551 ve = tsubst_expr (ve, args, complain, in_decl,
9552 /*constant_expression_p=*/false);
9553 SET_DECL_VALUE_EXPR (r, ve);
9556 else if (DECL_SELF_REFERENCE_P (t))
9557 SET_DECL_SELF_REFERENCE_P (r);
9558 TREE_TYPE (r) = type;
9559 cp_apply_type_quals_to_decl (cp_type_quals (type), r);
9560 DECL_CONTEXT (r) = ctx;
9561 /* Clear out the mangled name and RTL for the instantiation. */
9562 SET_DECL_ASSEMBLER_NAME (r, NULL_TREE);
9563 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
9564 SET_DECL_RTL (r, NULL_RTX);
9565 /* The initializer must not be expanded until it is required;
9567 DECL_INITIAL (r) = NULL_TREE;
9568 if (CODE_CONTAINS_STRUCT (TREE_CODE (t), TS_DECL_WRTL))
9569 SET_DECL_RTL (r, NULL_RTX);
9570 DECL_SIZE (r) = DECL_SIZE_UNIT (r) = 0;
9571 if (TREE_CODE (r) == VAR_DECL)
9573 /* Possibly limit visibility based on template args. */
9574 DECL_VISIBILITY (r) = VISIBILITY_DEFAULT;
9575 if (DECL_VISIBILITY_SPECIFIED (t))
9577 DECL_VISIBILITY_SPECIFIED (r) = 0;
9579 = remove_attribute ("visibility", DECL_ATTRIBUTES (r));
9581 determine_visibility (r);
9586 /* A static data member declaration is always marked
9587 external when it is declared in-class, even if an
9588 initializer is present. We mimic the non-template
9590 DECL_EXTERNAL (r) = 1;
9592 register_specialization (r, gen_tmpl, argvec, false, hash);
9593 DECL_TEMPLATE_INFO (r) = build_template_info (tmpl, argvec);
9594 SET_DECL_IMPLICIT_INSTANTIATION (r);
9596 else if (cp_unevaluated_operand)
9598 /* We're substituting this var in a decltype outside of its
9599 scope, such as for a lambda return type. Don't add it to
9600 local_specializations, do perform auto deduction. */
9601 tree auto_node = type_uses_auto (type);
9603 = tsubst_expr (DECL_INITIAL (t), args, complain, in_decl,
9604 /*constant_expression_p=*/false);
9606 if (auto_node && init && describable_type (init))
9608 type = do_auto_deduction (type, init, auto_node);
9609 TREE_TYPE (r) = type;
9613 register_local_specialization (r, t);
9615 TREE_CHAIN (r) = NULL_TREE;
9617 apply_late_template_attributes (&r, DECL_ATTRIBUTES (r),
9619 args, complain, in_decl);
9621 /* Preserve a typedef that names a type. */
9622 if (is_typedef_decl (r))
9624 DECL_ORIGINAL_TYPE (r) = NULL_TREE;
9625 set_underlying_type (r);
9638 /* Restore the file and line information. */
9639 input_location = saved_loc;
9644 /* Substitute into the ARG_TYPES of a function type. */
9647 tsubst_arg_types (tree arg_types,
9649 tsubst_flags_t complain,
9652 tree remaining_arg_types;
9653 tree type = NULL_TREE;
9655 tree expanded_args = NULL_TREE;
9658 if (!arg_types || arg_types == void_list_node)
9661 remaining_arg_types = tsubst_arg_types (TREE_CHAIN (arg_types),
9662 args, complain, in_decl);
9663 if (remaining_arg_types == error_mark_node)
9664 return error_mark_node;
9666 if (PACK_EXPANSION_P (TREE_VALUE (arg_types)))
9668 /* For a pack expansion, perform substitution on the
9669 entire expression. Later on, we'll handle the arguments
9671 expanded_args = tsubst_pack_expansion (TREE_VALUE (arg_types),
9672 args, complain, in_decl);
9674 if (TREE_CODE (expanded_args) == TREE_VEC)
9675 /* So that we'll spin through the parameters, one by one. */
9676 i = TREE_VEC_LENGTH (expanded_args);
9679 /* We only partially substituted into the parameter
9680 pack. Our type is TYPE_PACK_EXPANSION. */
9681 type = expanded_args;
9682 expanded_args = NULL_TREE;
9690 type = TREE_VEC_ELT (expanded_args, i);
9692 type = tsubst (TREE_VALUE (arg_types), args, complain, in_decl);
9694 if (type == error_mark_node)
9695 return error_mark_node;
9696 if (VOID_TYPE_P (type))
9698 if (complain & tf_error)
9700 error ("invalid parameter type %qT", type);
9702 error ("in declaration %q+D", in_decl);
9704 return error_mark_node;
9707 /* Do array-to-pointer, function-to-pointer conversion, and ignore
9708 top-level qualifiers as required. */
9709 type = TYPE_MAIN_VARIANT (type_decays_to (type));
9711 /* We do not substitute into default arguments here. The standard
9712 mandates that they be instantiated only when needed, which is
9713 done in build_over_call. */
9714 default_arg = TREE_PURPOSE (arg_types);
9716 if (default_arg && TREE_CODE (default_arg) == DEFAULT_ARG)
9718 /* We've instantiated a template before its default arguments
9719 have been parsed. This can happen for a nested template
9720 class, and is not an error unless we require the default
9721 argument in a call of this function. */
9722 remaining_arg_types =
9723 tree_cons (default_arg, type, remaining_arg_types);
9724 VEC_safe_push (tree, gc, DEFARG_INSTANTIATIONS (default_arg),
9725 remaining_arg_types);
9728 remaining_arg_types =
9729 hash_tree_cons (default_arg, type, remaining_arg_types);
9732 return remaining_arg_types;
9735 /* Substitute into a FUNCTION_TYPE or METHOD_TYPE. This routine does
9736 *not* handle the exception-specification for FNTYPE, because the
9737 initial substitution of explicitly provided template parameters
9738 during argument deduction forbids substitution into the
9739 exception-specification:
9743 All references in the function type of the function template to the
9744 corresponding template parameters are replaced by the specified tem-
9745 plate argument values. If a substitution in a template parameter or
9746 in the function type of the function template results in an invalid
9747 type, type deduction fails. [Note: The equivalent substitution in
9748 exception specifications is done only when the function is instanti-
9749 ated, at which point a program is ill-formed if the substitution
9750 results in an invalid type.] */
9753 tsubst_function_type (tree t,
9755 tsubst_flags_t complain,
9762 /* The TYPE_CONTEXT is not used for function/method types. */
9763 gcc_assert (TYPE_CONTEXT (t) == NULL_TREE);
9765 /* Substitute the return type. */
9766 return_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
9767 if (return_type == error_mark_node)
9768 return error_mark_node;
9769 /* The standard does not presently indicate that creation of a
9770 function type with an invalid return type is a deduction failure.
9771 However, that is clearly analogous to creating an array of "void"
9772 or a reference to a reference. This is core issue #486. */
9773 if (TREE_CODE (return_type) == ARRAY_TYPE
9774 || TREE_CODE (return_type) == FUNCTION_TYPE)
9776 if (complain & tf_error)
9778 if (TREE_CODE (return_type) == ARRAY_TYPE)
9779 error ("function returning an array");
9781 error ("function returning a function");
9783 return error_mark_node;
9786 /* Substitute the argument types. */
9787 arg_types = tsubst_arg_types (TYPE_ARG_TYPES (t), args,
9789 if (arg_types == error_mark_node)
9790 return error_mark_node;
9792 /* Construct a new type node and return it. */
9793 if (TREE_CODE (t) == FUNCTION_TYPE)
9794 fntype = build_function_type (return_type, arg_types);
9797 tree r = TREE_TYPE (TREE_VALUE (arg_types));
9798 if (! MAYBE_CLASS_TYPE_P (r))
9802 Type deduction may fail for any of the following
9805 -- Attempting to create "pointer to member of T" when T
9806 is not a class type. */
9807 if (complain & tf_error)
9808 error ("creating pointer to member function of non-class type %qT",
9810 return error_mark_node;
9813 fntype = build_method_type_directly (r, return_type,
9814 TREE_CHAIN (arg_types));
9816 fntype = cp_build_qualified_type_real (fntype, TYPE_QUALS (t), complain);
9817 fntype = cp_build_type_attribute_variant (fntype, TYPE_ATTRIBUTES (t));
9822 /* FNTYPE is a FUNCTION_TYPE or METHOD_TYPE. Substitute the template
9823 ARGS into that specification, and return the substituted
9824 specification. If there is no specification, return NULL_TREE. */
9827 tsubst_exception_specification (tree fntype,
9829 tsubst_flags_t complain,
9835 specs = TYPE_RAISES_EXCEPTIONS (fntype);
9836 new_specs = NULL_TREE;
9839 if (! TREE_VALUE (specs))
9846 tree expanded_specs = NULL_TREE;
9848 if (PACK_EXPANSION_P (TREE_VALUE (specs)))
9850 /* Expand the pack expansion type. */
9851 expanded_specs = tsubst_pack_expansion (TREE_VALUE (specs),
9855 if (expanded_specs == error_mark_node)
9856 return error_mark_node;
9857 else if (TREE_CODE (expanded_specs) == TREE_VEC)
9858 len = TREE_VEC_LENGTH (expanded_specs);
9861 /* We're substituting into a member template, so
9862 we got a TYPE_PACK_EXPANSION back. Add that
9863 expansion and move on. */
9864 gcc_assert (TREE_CODE (expanded_specs)
9865 == TYPE_PACK_EXPANSION);
9866 new_specs = add_exception_specifier (new_specs,
9869 specs = TREE_CHAIN (specs);
9874 for (i = 0; i < len; ++i)
9877 spec = TREE_VEC_ELT (expanded_specs, i);
9879 spec = tsubst (TREE_VALUE (specs), args, complain, in_decl);
9880 if (spec == error_mark_node)
9882 new_specs = add_exception_specifier (new_specs, spec,
9886 specs = TREE_CHAIN (specs);
9892 /* Take the tree structure T and replace template parameters used
9893 therein with the argument vector ARGS. IN_DECL is an associated
9894 decl for diagnostics. If an error occurs, returns ERROR_MARK_NODE.
9895 Issue error and warning messages under control of COMPLAIN. Note
9896 that we must be relatively non-tolerant of extensions here, in
9897 order to preserve conformance; if we allow substitutions that
9898 should not be allowed, we may allow argument deductions that should
9899 not succeed, and therefore report ambiguous overload situations
9900 where there are none. In theory, we could allow the substitution,
9901 but indicate that it should have failed, and allow our caller to
9902 make sure that the right thing happens, but we don't try to do this
9905 This function is used for dealing with types, decls and the like;
9906 for expressions, use tsubst_expr or tsubst_copy. */
9909 tsubst (tree t, tree args, tsubst_flags_t complain, tree in_decl)
9913 if (t == NULL_TREE || t == error_mark_node
9914 || t == integer_type_node
9915 || t == void_type_node
9916 || t == char_type_node
9917 || t == unknown_type_node
9918 || TREE_CODE (t) == NAMESPACE_DECL)
9922 return tsubst_decl (t, args, complain);
9924 if (args == NULL_TREE)
9927 if (TREE_CODE (t) == IDENTIFIER_NODE)
9928 type = IDENTIFIER_TYPE_VALUE (t);
9930 type = TREE_TYPE (t);
9932 gcc_assert (type != unknown_type_node);
9934 /* Reuse typedefs. We need to do this to handle dependent attributes,
9935 such as attribute aligned. */
9938 && TYPE_NAME (t) != TYPE_MAIN_DECL (t))
9940 tree decl = TYPE_NAME (t);
9942 if (DECL_CLASS_SCOPE_P (decl)
9943 && CLASSTYPE_TEMPLATE_INFO (DECL_CONTEXT (decl))
9944 && uses_template_parms (DECL_CONTEXT (decl)))
9946 tree tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
9947 tree gen_args = tsubst (DECL_TI_ARGS (decl), args, complain, in_decl);
9948 r = retrieve_specialization (tmpl, gen_args, 0);
9950 else if (DECL_FUNCTION_SCOPE_P (decl)
9951 && DECL_TEMPLATE_INFO (DECL_CONTEXT (decl))
9952 && uses_template_parms (DECL_TI_ARGS (DECL_CONTEXT (decl))))
9953 r = retrieve_local_specialization (decl);
9955 /* The typedef is from a non-template context. */
9961 r = cp_build_qualified_type_real
9962 (r, cp_type_quals (t) | cp_type_quals (r),
9963 complain | tf_ignore_bad_quals);
9966 /* Else we must be instantiating the typedef, so fall through. */
9970 && TREE_CODE (t) != TYPENAME_TYPE
9971 && TREE_CODE (t) != TEMPLATE_TYPE_PARM
9972 && TREE_CODE (t) != IDENTIFIER_NODE
9973 && TREE_CODE (t) != FUNCTION_TYPE
9974 && TREE_CODE (t) != METHOD_TYPE)
9975 type = tsubst (type, args, complain, in_decl);
9976 if (type == error_mark_node)
9977 return error_mark_node;
9979 switch (TREE_CODE (t))
9984 return tsubst_aggr_type (t, args, complain, in_decl,
9985 /*entering_scope=*/0);
9988 case IDENTIFIER_NODE:
10000 if (t == integer_type_node)
10003 if (TREE_CODE (TYPE_MIN_VALUE (t)) == INTEGER_CST
10004 && TREE_CODE (TYPE_MAX_VALUE (t)) == INTEGER_CST)
10008 tree max, omax = TREE_OPERAND (TYPE_MAX_VALUE (t), 0);
10010 max = tsubst_expr (omax, args, complain, in_decl,
10011 /*integral_constant_expression_p=*/false);
10013 /* Fix up type of the magic NOP_EXPR with TREE_SIDE_EFFECTS if
10015 if (TREE_CODE (max) == NOP_EXPR
10016 && TREE_SIDE_EFFECTS (omax)
10017 && !TREE_TYPE (max))
10018 TREE_TYPE (max) = TREE_TYPE (TREE_OPERAND (max, 0));
10020 max = fold_decl_constant_value (max);
10022 /* If we're in a partial instantiation, preserve the magic NOP_EXPR
10023 with TREE_SIDE_EFFECTS that indicates this is not an integral
10024 constant expression. */
10025 if (processing_template_decl
10026 && TREE_SIDE_EFFECTS (omax) && TREE_CODE (omax) == NOP_EXPR)
10028 gcc_assert (TREE_CODE (max) == NOP_EXPR);
10029 TREE_SIDE_EFFECTS (max) = 1;
10032 if (TREE_CODE (max) != INTEGER_CST
10033 && !at_function_scope_p ()
10034 && !TREE_SIDE_EFFECTS (max)
10035 && !value_dependent_expression_p (max))
10037 if (complain & tf_error)
10038 error ("array bound is not an integer constant");
10039 return error_mark_node;
10044 Type deduction may fail for any of the following
10047 Attempting to create an array with a size that is
10048 zero or negative. */
10049 if (integer_zerop (max) && !(complain & tf_error))
10050 /* We must fail if performing argument deduction (as
10051 indicated by the state of complain), so that
10052 another substitution can be found. */
10053 return error_mark_node;
10054 else if (TREE_CODE (max) == INTEGER_CST
10055 && INT_CST_LT (max, integer_zero_node))
10057 if (complain & tf_error)
10058 error ("creating array with negative size (%qE)", max);
10060 return error_mark_node;
10063 return compute_array_index_type (NULL_TREE, max);
10066 case TEMPLATE_TYPE_PARM:
10067 case TEMPLATE_TEMPLATE_PARM:
10068 case BOUND_TEMPLATE_TEMPLATE_PARM:
10069 case TEMPLATE_PARM_INDEX:
10074 tree arg = NULL_TREE;
10078 gcc_assert (TREE_VEC_LENGTH (args) > 0);
10079 template_parm_level_and_index (t, &level, &idx);
10081 levels = TMPL_ARGS_DEPTH (args);
10082 if (level <= levels)
10084 arg = TMPL_ARG (args, level, idx);
10086 if (arg && TREE_CODE (arg) == ARGUMENT_PACK_SELECT)
10087 /* See through ARGUMENT_PACK_SELECT arguments. */
10088 arg = ARGUMENT_PACK_SELECT_ARG (arg);
10091 if (arg == error_mark_node)
10092 return error_mark_node;
10093 else if (arg != NULL_TREE)
10095 if (ARGUMENT_PACK_P (arg))
10096 /* If ARG is an argument pack, we don't actually want to
10097 perform a substitution here, because substitutions
10098 for argument packs are only done
10099 element-by-element. We can get to this point when
10100 substituting the type of a non-type template
10101 parameter pack, when that type actually contains
10102 template parameter packs from an outer template, e.g.,
10104 template<typename... Types> struct A {
10105 template<Types... Values> struct B { };
10109 if (TREE_CODE (t) == TEMPLATE_TYPE_PARM)
10112 gcc_assert (TYPE_P (arg));
10114 /* cv-quals from the template are discarded when
10115 substituting in a function or reference type. */
10116 if (TREE_CODE (arg) == FUNCTION_TYPE
10117 || TREE_CODE (arg) == METHOD_TYPE
10118 || TREE_CODE (arg) == REFERENCE_TYPE)
10119 quals = cp_type_quals (arg);
10121 quals = cp_type_quals (arg) | cp_type_quals (t);
10123 return cp_build_qualified_type_real
10124 (arg, quals, complain | tf_ignore_bad_quals);
10126 else if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
10128 /* We are processing a type constructed from a
10129 template template parameter. */
10130 tree argvec = tsubst (TYPE_TI_ARGS (t),
10131 args, complain, in_decl);
10132 if (argvec == error_mark_node)
10133 return error_mark_node;
10135 /* We can get a TEMPLATE_TEMPLATE_PARM here when we
10136 are resolving nested-types in the signature of a
10137 member function templates. Otherwise ARG is a
10138 TEMPLATE_DECL and is the real template to be
10140 if (TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
10141 arg = TYPE_NAME (arg);
10143 r = lookup_template_class (arg,
10145 DECL_CONTEXT (arg),
10146 /*entering_scope=*/0,
10148 return cp_build_qualified_type_real
10149 (r, TYPE_QUALS (t), complain);
10152 /* TEMPLATE_TEMPLATE_PARM or TEMPLATE_PARM_INDEX. */
10153 return unshare_expr (arg);
10157 /* This can happen during the attempted tsubst'ing in
10158 unify. This means that we don't yet have any information
10159 about the template parameter in question. */
10162 /* If we get here, we must have been looking at a parm for a
10163 more deeply nested template. Make a new version of this
10164 template parameter, but with a lower level. */
10165 switch (TREE_CODE (t))
10167 case TEMPLATE_TYPE_PARM:
10168 case TEMPLATE_TEMPLATE_PARM:
10169 case BOUND_TEMPLATE_TEMPLATE_PARM:
10170 if (cp_type_quals (t))
10172 r = tsubst (TYPE_MAIN_VARIANT (t), args, complain, in_decl);
10173 r = cp_build_qualified_type_real
10174 (r, cp_type_quals (t),
10175 complain | (TREE_CODE (t) == TEMPLATE_TYPE_PARM
10176 ? tf_ignore_bad_quals : 0));
10181 TEMPLATE_TYPE_PARM_INDEX (r)
10182 = reduce_template_parm_level (TEMPLATE_TYPE_PARM_INDEX (t),
10183 r, levels, args, complain);
10184 TYPE_STUB_DECL (r) = TYPE_NAME (r) = TEMPLATE_TYPE_DECL (r);
10185 TYPE_MAIN_VARIANT (r) = r;
10186 TYPE_POINTER_TO (r) = NULL_TREE;
10187 TYPE_REFERENCE_TO (r) = NULL_TREE;
10189 if (TREE_CODE (r) == TEMPLATE_TEMPLATE_PARM)
10190 /* We have reduced the level of the template
10191 template parameter, but not the levels of its
10192 template parameters, so canonical_type_parameter
10193 will not be able to find the canonical template
10194 template parameter for this level. Thus, we
10195 require structural equality checking to compare
10196 TEMPLATE_TEMPLATE_PARMs. */
10197 SET_TYPE_STRUCTURAL_EQUALITY (r);
10198 else if (TYPE_STRUCTURAL_EQUALITY_P (t))
10199 SET_TYPE_STRUCTURAL_EQUALITY (r);
10201 TYPE_CANONICAL (r) = canonical_type_parameter (r);
10203 if (TREE_CODE (t) == BOUND_TEMPLATE_TEMPLATE_PARM)
10205 tree argvec = tsubst (TYPE_TI_ARGS (t), args,
10206 complain, in_decl);
10207 if (argvec == error_mark_node)
10208 return error_mark_node;
10210 TEMPLATE_TEMPLATE_PARM_TEMPLATE_INFO (r)
10211 = build_template_info (TYPE_TI_TEMPLATE (t), argvec);
10216 case TEMPLATE_PARM_INDEX:
10217 r = reduce_template_parm_level (t, type, levels, args, complain);
10221 gcc_unreachable ();
10229 tree purpose, value, chain;
10231 if (t == void_list_node)
10234 purpose = TREE_PURPOSE (t);
10237 purpose = tsubst (purpose, args, complain, in_decl);
10238 if (purpose == error_mark_node)
10239 return error_mark_node;
10241 value = TREE_VALUE (t);
10244 value = tsubst (value, args, complain, in_decl);
10245 if (value == error_mark_node)
10246 return error_mark_node;
10248 chain = TREE_CHAIN (t);
10249 if (chain && chain != void_type_node)
10251 chain = tsubst (chain, args, complain, in_decl);
10252 if (chain == error_mark_node)
10253 return error_mark_node;
10255 if (purpose == TREE_PURPOSE (t)
10256 && value == TREE_VALUE (t)
10257 && chain == TREE_CHAIN (t))
10259 return hash_tree_cons (purpose, value, chain);
10263 /* We should never be tsubsting a binfo. */
10264 gcc_unreachable ();
10267 /* A vector of template arguments. */
10268 gcc_assert (!type);
10269 return tsubst_template_args (t, args, complain, in_decl);
10272 case REFERENCE_TYPE:
10274 enum tree_code code;
10276 if (type == TREE_TYPE (t) && TREE_CODE (type) != METHOD_TYPE)
10279 code = TREE_CODE (t);
10284 Type deduction may fail for any of the following
10287 -- Attempting to create a pointer to reference type.
10288 -- Attempting to create a reference to a reference type or
10289 a reference to void.
10291 Core issue 106 says that creating a reference to a reference
10292 during instantiation is no longer a cause for failure. We
10293 only enforce this check in strict C++98 mode. */
10294 if ((TREE_CODE (type) == REFERENCE_TYPE
10295 && (((cxx_dialect == cxx98) && flag_iso) || code != REFERENCE_TYPE))
10296 || (code == REFERENCE_TYPE && TREE_CODE (type) == VOID_TYPE))
10298 static location_t last_loc;
10300 /* We keep track of the last time we issued this error
10301 message to avoid spewing a ton of messages during a
10302 single bad template instantiation. */
10303 if (complain & tf_error
10304 && last_loc != input_location)
10306 if (TREE_CODE (type) == VOID_TYPE)
10307 error ("forming reference to void");
10308 else if (code == POINTER_TYPE)
10309 error ("forming pointer to reference type %qT", type);
10311 error ("forming reference to reference type %qT", type);
10312 last_loc = input_location;
10315 return error_mark_node;
10317 else if (code == POINTER_TYPE)
10319 r = build_pointer_type (type);
10320 if (TREE_CODE (type) == METHOD_TYPE)
10321 r = build_ptrmemfunc_type (r);
10323 else if (TREE_CODE (type) == REFERENCE_TYPE)
10324 /* In C++0x, during template argument substitution, when there is an
10325 attempt to create a reference to a reference type, reference
10326 collapsing is applied as described in [14.3.1/4 temp.arg.type]:
10328 "If a template-argument for a template-parameter T names a type
10329 that is a reference to a type A, an attempt to create the type
10330 'lvalue reference to cv T' creates the type 'lvalue reference to
10331 A,' while an attempt to create the type type rvalue reference to
10332 cv T' creates the type T"
10334 r = cp_build_reference_type
10336 TYPE_REF_IS_RVALUE (t) && TYPE_REF_IS_RVALUE (type));
10338 r = cp_build_reference_type (type, TYPE_REF_IS_RVALUE (t));
10339 r = cp_build_qualified_type_real (r, TYPE_QUALS (t), complain);
10341 if (r != error_mark_node)
10342 /* Will this ever be needed for TYPE_..._TO values? */
10349 r = tsubst (TYPE_OFFSET_BASETYPE (t), args, complain, in_decl);
10350 if (r == error_mark_node || !MAYBE_CLASS_TYPE_P (r))
10354 Type deduction may fail for any of the following
10357 -- Attempting to create "pointer to member of T" when T
10358 is not a class type. */
10359 if (complain & tf_error)
10360 error ("creating pointer to member of non-class type %qT", r);
10361 return error_mark_node;
10363 if (TREE_CODE (type) == REFERENCE_TYPE)
10365 if (complain & tf_error)
10366 error ("creating pointer to member reference type %qT", type);
10367 return error_mark_node;
10369 if (TREE_CODE (type) == VOID_TYPE)
10371 if (complain & tf_error)
10372 error ("creating pointer to member of type void");
10373 return error_mark_node;
10375 gcc_assert (TREE_CODE (type) != METHOD_TYPE);
10376 if (TREE_CODE (type) == FUNCTION_TYPE)
10378 /* The type of the implicit object parameter gets its
10379 cv-qualifiers from the FUNCTION_TYPE. */
10381 tree method_type = build_memfn_type (type, r, cp_type_quals (type));
10382 memptr = build_ptrmemfunc_type (build_pointer_type (method_type));
10383 return cp_build_qualified_type_real (memptr, cp_type_quals (t),
10387 return cp_build_qualified_type_real (build_ptrmem_type (r, type),
10391 case FUNCTION_TYPE:
10396 fntype = tsubst_function_type (t, args, complain, in_decl);
10397 if (fntype == error_mark_node)
10398 return error_mark_node;
10400 /* Substitute the exception specification. */
10401 specs = tsubst_exception_specification (t, args, complain,
10403 if (specs == error_mark_node)
10404 return error_mark_node;
10406 fntype = build_exception_variant (fntype, specs);
10411 tree domain = tsubst (TYPE_DOMAIN (t), args, complain, in_decl);
10412 if (domain == error_mark_node)
10413 return error_mark_node;
10415 /* As an optimization, we avoid regenerating the array type if
10416 it will obviously be the same as T. */
10417 if (type == TREE_TYPE (t) && domain == TYPE_DOMAIN (t))
10420 /* These checks should match the ones in grokdeclarator.
10424 The deduction may fail for any of the following reasons:
10426 -- Attempting to create an array with an element type that
10427 is void, a function type, or a reference type, or [DR337]
10428 an abstract class type. */
10429 if (TREE_CODE (type) == VOID_TYPE
10430 || TREE_CODE (type) == FUNCTION_TYPE
10431 || TREE_CODE (type) == REFERENCE_TYPE)
10433 if (complain & tf_error)
10434 error ("creating array of %qT", type);
10435 return error_mark_node;
10437 if (CLASS_TYPE_P (type) && CLASSTYPE_PURE_VIRTUALS (type))
10439 if (complain & tf_error)
10440 error ("creating array of %qT, which is an abstract class type",
10442 return error_mark_node;
10445 r = build_cplus_array_type (type, domain);
10447 if (TYPE_USER_ALIGN (t))
10449 TYPE_ALIGN (r) = TYPE_ALIGN (t);
10450 TYPE_USER_ALIGN (r) = 1;
10459 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
10460 tree e2 = tsubst (TREE_OPERAND (t, 1), args, complain, in_decl);
10462 if (e1 == error_mark_node || e2 == error_mark_node)
10463 return error_mark_node;
10465 return fold_build2_loc (input_location,
10466 TREE_CODE (t), TREE_TYPE (t), e1, e2);
10472 tree e = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
10473 if (e == error_mark_node)
10474 return error_mark_node;
10476 return fold_build1_loc (input_location, TREE_CODE (t), TREE_TYPE (t), e);
10479 case TYPENAME_TYPE:
10481 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
10482 in_decl, /*entering_scope=*/1);
10483 tree f = tsubst_copy (TYPENAME_TYPE_FULLNAME (t), args,
10484 complain, in_decl);
10486 if (ctx == error_mark_node || f == error_mark_node)
10487 return error_mark_node;
10489 if (!MAYBE_CLASS_TYPE_P (ctx))
10491 if (complain & tf_error)
10492 error ("%qT is not a class, struct, or union type", ctx);
10493 return error_mark_node;
10495 else if (!uses_template_parms (ctx) && !TYPE_BEING_DEFINED (ctx))
10497 /* Normally, make_typename_type does not require that the CTX
10498 have complete type in order to allow things like:
10500 template <class T> struct S { typename S<T>::X Y; };
10502 But, such constructs have already been resolved by this
10503 point, so here CTX really should have complete type, unless
10504 it's a partial instantiation. */
10505 if (!(complain & tf_no_class_instantiations))
10506 ctx = complete_type (ctx);
10507 if (!COMPLETE_TYPE_P (ctx))
10509 if (complain & tf_error)
10510 cxx_incomplete_type_error (NULL_TREE, ctx);
10511 return error_mark_node;
10515 f = make_typename_type (ctx, f, typename_type,
10516 (complain & tf_error) | tf_keep_type_decl);
10517 if (f == error_mark_node)
10519 if (TREE_CODE (f) == TYPE_DECL)
10521 complain |= tf_ignore_bad_quals;
10525 if (TREE_CODE (f) != TYPENAME_TYPE)
10527 if (TYPENAME_IS_ENUM_P (t) && TREE_CODE (f) != ENUMERAL_TYPE)
10528 error ("%qT resolves to %qT, which is not an enumeration type",
10530 else if (TYPENAME_IS_CLASS_P (t) && !CLASS_TYPE_P (f))
10531 error ("%qT resolves to %qT, which is is not a class type",
10535 return cp_build_qualified_type_real
10536 (f, cp_type_quals (f) | cp_type_quals (t), complain);
10539 case UNBOUND_CLASS_TEMPLATE:
10541 tree ctx = tsubst_aggr_type (TYPE_CONTEXT (t), args, complain,
10542 in_decl, /*entering_scope=*/1);
10543 tree name = TYPE_IDENTIFIER (t);
10544 tree parm_list = DECL_TEMPLATE_PARMS (TYPE_NAME (t));
10546 if (ctx == error_mark_node || name == error_mark_node)
10547 return error_mark_node;
10550 parm_list = tsubst_template_parms (parm_list, args, complain);
10551 return make_unbound_class_template (ctx, name, parm_list, complain);
10557 gcc_unreachable ();
10561 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
10562 tree e2 = tsubst_expr (TREE_OPERAND (t, 1), args, complain, in_decl,
10563 /*integral_constant_expression_p=*/false);
10564 if (e1 == error_mark_node || e2 == error_mark_node)
10565 return error_mark_node;
10567 return build_nt (ARRAY_REF, e1, e2, NULL_TREE, NULL_TREE);
10572 tree e1 = tsubst (TREE_OPERAND (t, 0), args, complain, in_decl);
10573 tree e2 = tsubst (TREE_OPERAND (t, 1), args, complain, in_decl);
10574 if (e1 == error_mark_node || e2 == error_mark_node)
10575 return error_mark_node;
10577 return build_qualified_name (/*type=*/NULL_TREE,
10578 e1, e2, QUALIFIED_NAME_IS_TEMPLATE (t));
10585 ++cp_unevaluated_operand;
10586 ++c_inhibit_evaluation_warnings;
10588 type = tsubst_expr (TYPEOF_TYPE_EXPR (t), args,
10590 /*integral_constant_expression_p=*/false);
10592 --cp_unevaluated_operand;
10593 --c_inhibit_evaluation_warnings;
10595 type = finish_typeof (type);
10596 return cp_build_qualified_type_real (type,
10598 | cp_type_quals (type),
10602 case DECLTYPE_TYPE:
10606 ++cp_unevaluated_operand;
10607 ++c_inhibit_evaluation_warnings;
10609 type = tsubst_expr (DECLTYPE_TYPE_EXPR (t), args,
10611 /*integral_constant_expression_p=*/false);
10613 --cp_unevaluated_operand;
10614 --c_inhibit_evaluation_warnings;
10616 if (DECLTYPE_FOR_LAMBDA_CAPTURE (t))
10617 type = lambda_capture_field_type (type);
10618 else if (DECLTYPE_FOR_LAMBDA_RETURN (t))
10619 type = lambda_return_type (type);
10621 type = finish_decltype_type
10622 (type, DECLTYPE_TYPE_ID_EXPR_OR_MEMBER_ACCESS_P (t));
10623 return cp_build_qualified_type_real (type,
10625 | cp_type_quals (type),
10629 case TYPE_ARGUMENT_PACK:
10630 case NONTYPE_ARGUMENT_PACK:
10632 tree r = TYPE_P (t)
10633 ? cxx_make_type (TREE_CODE (t))
10634 : make_node (TREE_CODE (t));
10636 tsubst_template_args (ARGUMENT_PACK_ARGS (t),
10640 SET_ARGUMENT_PACK_ARGS (r, packed_out);
10642 /* For template nontype argument packs, also substitute into
10644 if (TREE_CODE (t) == NONTYPE_ARGUMENT_PACK)
10645 TREE_TYPE (r) = tsubst (TREE_TYPE (t), args, complain, in_decl);
10652 sorry ("use of %qs in template",
10653 tree_code_name [(int) TREE_CODE (t)]);
10654 return error_mark_node;
10658 /* Like tsubst_expr for a BASELINK. OBJECT_TYPE, if non-NULL, is the
10659 type of the expression on the left-hand side of the "." or "->"
10663 tsubst_baselink (tree baselink, tree object_type,
10664 tree args, tsubst_flags_t complain, tree in_decl)
10667 tree qualifying_scope;
10670 tree template_args = 0;
10671 bool template_id_p = false;
10673 /* A baselink indicates a function from a base class. Both the
10674 BASELINK_ACCESS_BINFO and the base class referenced may
10675 indicate bases of the template class, rather than the
10676 instantiated class. In addition, lookups that were not
10677 ambiguous before may be ambiguous now. Therefore, we perform
10678 the lookup again. */
10679 qualifying_scope = BINFO_TYPE (BASELINK_ACCESS_BINFO (baselink));
10680 qualifying_scope = tsubst (qualifying_scope, args,
10681 complain, in_decl);
10682 fns = BASELINK_FUNCTIONS (baselink);
10683 optype = tsubst (BASELINK_OPTYPE (baselink), args, complain, in_decl);
10684 if (TREE_CODE (fns) == TEMPLATE_ID_EXPR)
10686 template_id_p = true;
10687 template_args = TREE_OPERAND (fns, 1);
10688 fns = TREE_OPERAND (fns, 0);
10690 template_args = tsubst_template_args (template_args, args,
10691 complain, in_decl);
10693 name = DECL_NAME (get_first_fn (fns));
10694 if (IDENTIFIER_TYPENAME_P (name))
10695 name = mangle_conv_op_name_for_type (optype);
10696 baselink = lookup_fnfields (qualifying_scope, name, /*protect=*/1);
10698 /* If lookup found a single function, mark it as used at this
10699 point. (If it lookup found multiple functions the one selected
10700 later by overload resolution will be marked as used at that
10702 if (BASELINK_P (baselink))
10703 fns = BASELINK_FUNCTIONS (baselink);
10704 if (!template_id_p && !really_overloaded_fn (fns))
10705 mark_used (OVL_CURRENT (fns));
10707 /* Add back the template arguments, if present. */
10708 if (BASELINK_P (baselink) && template_id_p)
10709 BASELINK_FUNCTIONS (baselink)
10710 = build_nt (TEMPLATE_ID_EXPR,
10711 BASELINK_FUNCTIONS (baselink),
10713 /* Update the conversion operator type. */
10714 BASELINK_OPTYPE (baselink) = optype;
10717 object_type = current_class_type;
10718 return adjust_result_of_qualified_name_lookup (baselink,
10723 /* Like tsubst_expr for a SCOPE_REF, given by QUALIFIED_ID. DONE is
10724 true if the qualified-id will be a postfix-expression in-and-of
10725 itself; false if more of the postfix-expression follows the
10726 QUALIFIED_ID. ADDRESS_P is true if the qualified-id is the operand
10730 tsubst_qualified_id (tree qualified_id, tree args,
10731 tsubst_flags_t complain, tree in_decl,
10732 bool done, bool address_p)
10738 tree template_args;
10740 gcc_assert (TREE_CODE (qualified_id) == SCOPE_REF);
10742 /* Figure out what name to look up. */
10743 name = TREE_OPERAND (qualified_id, 1);
10744 if (TREE_CODE (name) == TEMPLATE_ID_EXPR)
10746 is_template = true;
10747 template_args = TREE_OPERAND (name, 1);
10749 template_args = tsubst_template_args (template_args, args,
10750 complain, in_decl);
10751 name = TREE_OPERAND (name, 0);
10755 is_template = false;
10756 template_args = NULL_TREE;
10759 /* Substitute into the qualifying scope. When there are no ARGS, we
10760 are just trying to simplify a non-dependent expression. In that
10761 case the qualifying scope may be dependent, and, in any case,
10762 substituting will not help. */
10763 scope = TREE_OPERAND (qualified_id, 0);
10766 scope = tsubst (scope, args, complain, in_decl);
10767 expr = tsubst_copy (name, args, complain, in_decl);
10772 if (dependent_scope_p (scope))
10773 return build_qualified_name (NULL_TREE, scope, expr,
10774 QUALIFIED_NAME_IS_TEMPLATE (qualified_id));
10776 if (!BASELINK_P (name) && !DECL_P (expr))
10778 if (TREE_CODE (expr) == BIT_NOT_EXPR)
10780 /* A BIT_NOT_EXPR is used to represent a destructor. */
10781 if (!check_dtor_name (scope, TREE_OPERAND (expr, 0)))
10783 error ("qualifying type %qT does not match destructor name ~%qT",
10784 scope, TREE_OPERAND (expr, 0));
10785 expr = error_mark_node;
10788 expr = lookup_qualified_name (scope, complete_dtor_identifier,
10789 /*is_type_p=*/0, false);
10792 expr = lookup_qualified_name (scope, expr, /*is_type_p=*/0, false);
10793 if (TREE_CODE (TREE_CODE (expr) == TEMPLATE_DECL
10794 ? DECL_TEMPLATE_RESULT (expr) : expr) == TYPE_DECL)
10796 if (complain & tf_error)
10798 error ("dependent-name %qE is parsed as a non-type, but "
10799 "instantiation yields a type", qualified_id);
10800 inform (input_location, "say %<typename %E%> if a type is meant", qualified_id);
10802 return error_mark_node;
10808 check_accessibility_of_qualified_id (expr, /*object_type=*/NULL_TREE,
10810 /* Remember that there was a reference to this entity. */
10814 if (expr == error_mark_node || TREE_CODE (expr) == TREE_LIST)
10816 if (complain & tf_error)
10817 qualified_name_lookup_error (scope,
10818 TREE_OPERAND (qualified_id, 1),
10819 expr, input_location);
10820 return error_mark_node;
10824 expr = lookup_template_function (expr, template_args);
10826 if (expr == error_mark_node && complain & tf_error)
10827 qualified_name_lookup_error (scope, TREE_OPERAND (qualified_id, 1),
10828 expr, input_location);
10829 else if (TYPE_P (scope))
10831 expr = (adjust_result_of_qualified_name_lookup
10832 (expr, scope, current_class_type));
10833 expr = (finish_qualified_id_expr
10834 (scope, expr, done, address_p,
10835 QUALIFIED_NAME_IS_TEMPLATE (qualified_id),
10836 /*template_arg_p=*/false));
10839 /* Expressions do not generally have reference type. */
10840 if (TREE_CODE (expr) != SCOPE_REF
10841 /* However, if we're about to form a pointer-to-member, we just
10842 want the referenced member referenced. */
10843 && TREE_CODE (expr) != OFFSET_REF)
10844 expr = convert_from_reference (expr);
10849 /* Like tsubst, but deals with expressions. This function just replaces
10850 template parms; to finish processing the resultant expression, use
10854 tsubst_copy (tree t, tree args, tsubst_flags_t complain, tree in_decl)
10856 enum tree_code code;
10859 if (t == NULL_TREE || t == error_mark_node || args == NULL_TREE)
10862 code = TREE_CODE (t);
10867 r = retrieve_local_specialization (t);
10872 /* This can happen for a parameter name used later in a function
10873 declaration (such as in a late-specified return type). Just
10874 make a dummy decl, since it's only used for its type. */
10875 gcc_assert (cp_unevaluated_operand != 0);
10876 /* We copy T because want to tsubst the PARM_DECL only,
10877 not the following PARM_DECLs that are chained to T. */
10879 r = tsubst_decl (c, args, complain);
10880 /* Give it the template pattern as its context; its true context
10881 hasn't been instantiated yet and this is good enough for
10883 DECL_CONTEXT (r) = DECL_CONTEXT (t);
10886 if (TREE_CODE (r) == ARGUMENT_PACK_SELECT)
10887 r = ARGUMENT_PACK_SELECT_ARG (r);
10896 if (DECL_TEMPLATE_PARM_P (t))
10897 return tsubst_copy (DECL_INITIAL (t), args, complain, in_decl);
10898 /* There is no need to substitute into namespace-scope
10900 if (DECL_NAMESPACE_SCOPE_P (t))
10902 /* If ARGS is NULL, then T is known to be non-dependent. */
10903 if (args == NULL_TREE)
10904 return integral_constant_value (t);
10906 /* Unfortunately, we cannot just call lookup_name here.
10909 template <int I> int f() {
10911 struct S { void g() { E e = a; } };
10914 When we instantiate f<7>::S::g(), say, lookup_name is not
10915 clever enough to find f<7>::a. */
10917 = tsubst_aggr_type (TREE_TYPE (t), args, complain, in_decl,
10918 /*entering_scope=*/0);
10920 for (v = TYPE_VALUES (enum_type);
10922 v = TREE_CHAIN (v))
10923 if (TREE_PURPOSE (v) == DECL_NAME (t))
10924 return TREE_VALUE (v);
10926 /* We didn't find the name. That should never happen; if
10927 name-lookup found it during preliminary parsing, we
10928 should find it again here during instantiation. */
10929 gcc_unreachable ();
10934 if (DECL_CONTEXT (t))
10938 ctx = tsubst_aggr_type (DECL_CONTEXT (t), args, complain, in_decl,
10939 /*entering_scope=*/1);
10940 if (ctx != DECL_CONTEXT (t))
10942 tree r = lookup_field (ctx, DECL_NAME (t), 0, false);
10945 if (complain & tf_error)
10946 error ("using invalid field %qD", t);
10947 return error_mark_node;
10956 case FUNCTION_DECL:
10957 if ((DECL_LANG_SPECIFIC (t) && DECL_TEMPLATE_INFO (t))
10958 || local_variable_p (t))
10959 t = tsubst (t, args, complain, in_decl);
10964 return tsubst_baselink (t, current_class_type, args, complain, in_decl);
10966 case TEMPLATE_DECL:
10967 if (DECL_TEMPLATE_TEMPLATE_PARM_P (t))
10968 return tsubst (TREE_TYPE (DECL_TEMPLATE_RESULT (t)),
10969 args, complain, in_decl);
10970 else if (DECL_FUNCTION_TEMPLATE_P (t) && DECL_MEMBER_TEMPLATE_P (t))
10971 return tsubst (t, args, complain, in_decl);
10972 else if (DECL_CLASS_SCOPE_P (t)
10973 && uses_template_parms (DECL_CONTEXT (t)))
10975 /* Template template argument like the following example need
10978 template <template <class> class TT> struct C {};
10979 template <class T> struct D {
10980 template <class U> struct E {};
10985 We are processing the template argument `E' in #1 for
10986 the template instantiation #2. Originally, `E' is a
10987 TEMPLATE_DECL with `D<T>' as its DECL_CONTEXT. Now we
10988 have to substitute this with one having context `D<int>'. */
10990 tree context = tsubst (DECL_CONTEXT (t), args, complain, in_decl);
10991 return lookup_field (context, DECL_NAME(t), 0, false);
10994 /* Ordinary template template argument. */
10998 case REINTERPRET_CAST_EXPR:
10999 case CONST_CAST_EXPR:
11000 case STATIC_CAST_EXPR:
11001 case DYNAMIC_CAST_EXPR:
11004 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
11005 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
11008 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
11010 /* We only want to compute the number of arguments. */
11011 tree expanded = tsubst_pack_expansion (TREE_OPERAND (t, 0), args,
11012 complain, in_decl);
11015 if (TREE_CODE (expanded) == TREE_VEC)
11016 len = TREE_VEC_LENGTH (expanded);
11018 if (expanded == error_mark_node)
11019 return error_mark_node;
11020 else if (PACK_EXPANSION_P (expanded)
11021 || (TREE_CODE (expanded) == TREE_VEC
11023 && PACK_EXPANSION_P (TREE_VEC_ELT (expanded, len-1))))
11025 if (TREE_CODE (expanded) == TREE_VEC)
11026 expanded = TREE_VEC_ELT (expanded, len - 1);
11028 if (TYPE_P (expanded))
11029 return cxx_sizeof_or_alignof_type (expanded, SIZEOF_EXPR,
11030 complain & tf_error);
11032 return cxx_sizeof_or_alignof_expr (expanded, SIZEOF_EXPR,
11033 complain & tf_error);
11036 return build_int_cst (size_type_node, len);
11042 case TRUTH_NOT_EXPR:
11045 case UNARY_PLUS_EXPR: /* Unary + */
11050 case REALPART_EXPR:
11051 case IMAGPART_EXPR:
11053 (code, tsubst (TREE_TYPE (t), args, complain, in_decl),
11054 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl));
11056 case COMPONENT_REF:
11061 object = tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl);
11062 name = TREE_OPERAND (t, 1);
11063 if (TREE_CODE (name) == BIT_NOT_EXPR)
11065 name = tsubst_copy (TREE_OPERAND (name, 0), args,
11066 complain, in_decl);
11067 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
11069 else if (TREE_CODE (name) == SCOPE_REF
11070 && TREE_CODE (TREE_OPERAND (name, 1)) == BIT_NOT_EXPR)
11072 tree base = tsubst_copy (TREE_OPERAND (name, 0), args,
11073 complain, in_decl);
11074 name = TREE_OPERAND (name, 1);
11075 name = tsubst_copy (TREE_OPERAND (name, 0), args,
11076 complain, in_decl);
11077 name = build1 (BIT_NOT_EXPR, NULL_TREE, name);
11078 name = build_qualified_name (/*type=*/NULL_TREE,
11080 /*template_p=*/false);
11082 else if (TREE_CODE (name) == BASELINK)
11083 name = tsubst_baselink (name,
11084 non_reference (TREE_TYPE (object)),
11088 name = tsubst_copy (name, args, complain, in_decl);
11089 return build_nt (COMPONENT_REF, object, name, NULL_TREE);
11095 case TRUNC_DIV_EXPR:
11096 case CEIL_DIV_EXPR:
11097 case FLOOR_DIV_EXPR:
11098 case ROUND_DIV_EXPR:
11099 case EXACT_DIV_EXPR:
11103 case TRUNC_MOD_EXPR:
11104 case FLOOR_MOD_EXPR:
11105 case TRUTH_ANDIF_EXPR:
11106 case TRUTH_ORIF_EXPR:
11107 case TRUTH_AND_EXPR:
11108 case TRUTH_OR_EXPR:
11121 case COMPOUND_EXPR:
11124 case PREDECREMENT_EXPR:
11125 case PREINCREMENT_EXPR:
11126 case POSTDECREMENT_EXPR:
11127 case POSTINCREMENT_EXPR:
11129 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11130 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
11133 return build_qualified_name (/*type=*/NULL_TREE,
11134 tsubst_copy (TREE_OPERAND (t, 0),
11135 args, complain, in_decl),
11136 tsubst_copy (TREE_OPERAND (t, 1),
11137 args, complain, in_decl),
11138 QUALIFIED_NAME_IS_TEMPLATE (t));
11143 tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11144 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
11145 NULL_TREE, NULL_TREE);
11149 int n = VL_EXP_OPERAND_LENGTH (t);
11150 tree result = build_vl_exp (CALL_EXPR, n);
11152 for (i = 0; i < n; i++)
11153 TREE_OPERAND (t, i) = tsubst_copy (TREE_OPERAND (t, i), args,
11154 complain, in_decl);
11160 case PSEUDO_DTOR_EXPR:
11163 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11164 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
11165 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
11166 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
11173 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11174 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl),
11175 tsubst_copy (TREE_OPERAND (t, 2), args, complain, in_decl));
11176 NEW_EXPR_USE_GLOBAL (r) = NEW_EXPR_USE_GLOBAL (t);
11183 (code, tsubst_copy (TREE_OPERAND (t, 0), args, complain, in_decl),
11184 tsubst_copy (TREE_OPERAND (t, 1), args, complain, in_decl));
11185 DELETE_EXPR_USE_GLOBAL (r) = DELETE_EXPR_USE_GLOBAL (t);
11186 DELETE_EXPR_USE_VEC (r) = DELETE_EXPR_USE_VEC (t);
11190 case TEMPLATE_ID_EXPR:
11192 /* Substituted template arguments */
11193 tree fn = TREE_OPERAND (t, 0);
11194 tree targs = TREE_OPERAND (t, 1);
11196 fn = tsubst_copy (fn, args, complain, in_decl);
11198 targs = tsubst_template_args (targs, args, complain, in_decl);
11200 return lookup_template_function (fn, targs);
11205 tree purpose, value, chain;
11207 if (t == void_list_node)
11210 purpose = TREE_PURPOSE (t);
11212 purpose = tsubst_copy (purpose, args, complain, in_decl);
11213 value = TREE_VALUE (t);
11215 value = tsubst_copy (value, args, complain, in_decl);
11216 chain = TREE_CHAIN (t);
11217 if (chain && chain != void_type_node)
11218 chain = tsubst_copy (chain, args, complain, in_decl);
11219 if (purpose == TREE_PURPOSE (t)
11220 && value == TREE_VALUE (t)
11221 && chain == TREE_CHAIN (t))
11223 return tree_cons (purpose, value, chain);
11228 case ENUMERAL_TYPE:
11230 case TEMPLATE_TYPE_PARM:
11231 case TEMPLATE_TEMPLATE_PARM:
11232 case BOUND_TEMPLATE_TEMPLATE_PARM:
11233 case TEMPLATE_PARM_INDEX:
11235 case REFERENCE_TYPE:
11237 case FUNCTION_TYPE:
11240 case TYPENAME_TYPE:
11241 case UNBOUND_CLASS_TEMPLATE:
11243 case DECLTYPE_TYPE:
11245 return tsubst (t, args, complain, in_decl);
11247 case IDENTIFIER_NODE:
11248 if (IDENTIFIER_TYPENAME_P (t))
11250 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
11251 return mangle_conv_op_name_for_type (new_type);
11257 /* This is handled by tsubst_copy_and_build. */
11258 gcc_unreachable ();
11261 return build_x_va_arg (tsubst_copy (TREE_OPERAND (t, 0), args, complain,
11263 tsubst (TREE_TYPE (t), args, complain, in_decl));
11265 case CLEANUP_POINT_EXPR:
11266 /* We shouldn't have built any of these during initial template
11267 generation. Instead, they should be built during instantiation
11268 in response to the saved STMT_IS_FULL_EXPR_P setting. */
11269 gcc_unreachable ();
11272 mark_used (TREE_OPERAND (t, 1));
11275 case EXPR_PACK_EXPANSION:
11276 error ("invalid use of pack expansion expression");
11277 return error_mark_node;
11279 case NONTYPE_ARGUMENT_PACK:
11280 error ("use %<...%> to expand argument pack");
11281 return error_mark_node;
11288 /* Like tsubst_copy, but specifically for OpenMP clauses. */
11291 tsubst_omp_clauses (tree clauses, tree args, tsubst_flags_t complain,
11294 tree new_clauses = NULL, nc, oc;
11296 for (oc = clauses; oc ; oc = OMP_CLAUSE_CHAIN (oc))
11298 nc = copy_node (oc);
11299 OMP_CLAUSE_CHAIN (nc) = new_clauses;
11302 switch (OMP_CLAUSE_CODE (nc))
11304 case OMP_CLAUSE_LASTPRIVATE:
11305 if (OMP_CLAUSE_LASTPRIVATE_STMT (oc))
11307 OMP_CLAUSE_LASTPRIVATE_STMT (nc) = push_stmt_list ();
11308 tsubst_expr (OMP_CLAUSE_LASTPRIVATE_STMT (oc), args, complain,
11309 in_decl, /*integral_constant_expression_p=*/false);
11310 OMP_CLAUSE_LASTPRIVATE_STMT (nc)
11311 = pop_stmt_list (OMP_CLAUSE_LASTPRIVATE_STMT (nc));
11314 case OMP_CLAUSE_PRIVATE:
11315 case OMP_CLAUSE_SHARED:
11316 case OMP_CLAUSE_FIRSTPRIVATE:
11317 case OMP_CLAUSE_REDUCTION:
11318 case OMP_CLAUSE_COPYIN:
11319 case OMP_CLAUSE_COPYPRIVATE:
11320 case OMP_CLAUSE_IF:
11321 case OMP_CLAUSE_NUM_THREADS:
11322 case OMP_CLAUSE_SCHEDULE:
11323 case OMP_CLAUSE_COLLAPSE:
11324 OMP_CLAUSE_OPERAND (nc, 0)
11325 = tsubst_expr (OMP_CLAUSE_OPERAND (oc, 0), args, complain,
11326 in_decl, /*integral_constant_expression_p=*/false);
11328 case OMP_CLAUSE_NOWAIT:
11329 case OMP_CLAUSE_ORDERED:
11330 case OMP_CLAUSE_DEFAULT:
11331 case OMP_CLAUSE_UNTIED:
11334 gcc_unreachable ();
11338 return finish_omp_clauses (nreverse (new_clauses));
11341 /* Like tsubst_copy_and_build, but unshare TREE_LIST nodes. */
11344 tsubst_copy_asm_operands (tree t, tree args, tsubst_flags_t complain,
11347 #define RECUR(t) tsubst_copy_asm_operands (t, args, complain, in_decl)
11349 tree purpose, value, chain;
11354 if (TREE_CODE (t) != TREE_LIST)
11355 return tsubst_copy_and_build (t, args, complain, in_decl,
11356 /*function_p=*/false,
11357 /*integral_constant_expression_p=*/false);
11359 if (t == void_list_node)
11362 purpose = TREE_PURPOSE (t);
11364 purpose = RECUR (purpose);
11365 value = TREE_VALUE (t);
11366 if (value && TREE_CODE (value) != LABEL_DECL)
11367 value = RECUR (value);
11368 chain = TREE_CHAIN (t);
11369 if (chain && chain != void_type_node)
11370 chain = RECUR (chain);
11371 return tree_cons (purpose, value, chain);
11375 /* Substitute one OMP_FOR iterator. */
11378 tsubst_omp_for_iterator (tree t, int i, tree declv, tree initv,
11379 tree condv, tree incrv, tree *clauses,
11380 tree args, tsubst_flags_t complain, tree in_decl,
11381 bool integral_constant_expression_p)
11383 #define RECUR(NODE) \
11384 tsubst_expr ((NODE), args, complain, in_decl, \
11385 integral_constant_expression_p)
11386 tree decl, init, cond, incr, auto_node;
11388 init = TREE_VEC_ELT (OMP_FOR_INIT (t), i);
11389 gcc_assert (TREE_CODE (init) == MODIFY_EXPR);
11390 decl = RECUR (TREE_OPERAND (init, 0));
11391 init = TREE_OPERAND (init, 1);
11392 auto_node = type_uses_auto (TREE_TYPE (decl));
11393 if (auto_node && init)
11395 tree init_expr = init;
11396 if (TREE_CODE (init_expr) == DECL_EXPR)
11397 init_expr = DECL_INITIAL (DECL_EXPR_DECL (init_expr));
11398 init_expr = RECUR (init_expr);
11400 = do_auto_deduction (TREE_TYPE (decl), init_expr, auto_node);
11402 gcc_assert (!type_dependent_expression_p (decl));
11404 if (!CLASS_TYPE_P (TREE_TYPE (decl)))
11406 cond = RECUR (TREE_VEC_ELT (OMP_FOR_COND (t), i));
11407 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
11408 if (TREE_CODE (incr) == MODIFY_EXPR)
11409 incr = build_x_modify_expr (RECUR (TREE_OPERAND (incr, 0)), NOP_EXPR,
11410 RECUR (TREE_OPERAND (incr, 1)),
11413 incr = RECUR (incr);
11414 TREE_VEC_ELT (declv, i) = decl;
11415 TREE_VEC_ELT (initv, i) = init;
11416 TREE_VEC_ELT (condv, i) = cond;
11417 TREE_VEC_ELT (incrv, i) = incr;
11421 if (init && TREE_CODE (init) != DECL_EXPR)
11424 for (c = *clauses; c ; c = OMP_CLAUSE_CHAIN (c))
11426 if ((OMP_CLAUSE_CODE (c) == OMP_CLAUSE_PRIVATE
11427 || OMP_CLAUSE_CODE (c) == OMP_CLAUSE_LASTPRIVATE)
11428 && OMP_CLAUSE_DECL (c) == decl)
11430 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_FIRSTPRIVATE
11431 && OMP_CLAUSE_DECL (c) == decl)
11432 error ("iteration variable %qD should not be firstprivate", decl);
11433 else if (OMP_CLAUSE_CODE (c) == OMP_CLAUSE_REDUCTION
11434 && OMP_CLAUSE_DECL (c) == decl)
11435 error ("iteration variable %qD should not be reduction", decl);
11439 c = build_omp_clause (input_location, OMP_CLAUSE_PRIVATE);
11440 OMP_CLAUSE_DECL (c) = decl;
11441 c = finish_omp_clauses (c);
11444 OMP_CLAUSE_CHAIN (c) = *clauses;
11449 cond = TREE_VEC_ELT (OMP_FOR_COND (t), i);
11450 if (COMPARISON_CLASS_P (cond))
11451 cond = build2 (TREE_CODE (cond), boolean_type_node,
11452 RECUR (TREE_OPERAND (cond, 0)),
11453 RECUR (TREE_OPERAND (cond, 1)));
11455 cond = RECUR (cond);
11456 incr = TREE_VEC_ELT (OMP_FOR_INCR (t), i);
11457 switch (TREE_CODE (incr))
11459 case PREINCREMENT_EXPR:
11460 case PREDECREMENT_EXPR:
11461 case POSTINCREMENT_EXPR:
11462 case POSTDECREMENT_EXPR:
11463 incr = build2 (TREE_CODE (incr), TREE_TYPE (decl),
11464 RECUR (TREE_OPERAND (incr, 0)), NULL_TREE);
11467 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
11468 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
11470 tree rhs = TREE_OPERAND (incr, 1);
11471 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
11472 RECUR (TREE_OPERAND (incr, 0)),
11473 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
11474 RECUR (TREE_OPERAND (rhs, 0)),
11475 RECUR (TREE_OPERAND (rhs, 1))));
11478 incr = RECUR (incr);
11481 if (TREE_CODE (TREE_OPERAND (incr, 1)) == PLUS_EXPR
11482 || TREE_CODE (TREE_OPERAND (incr, 1)) == MINUS_EXPR)
11484 tree lhs = RECUR (TREE_OPERAND (incr, 0));
11485 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl), lhs,
11486 build2 (TREE_CODE (TREE_OPERAND (incr, 1)),
11487 TREE_TYPE (decl), lhs,
11488 RECUR (TREE_OPERAND (incr, 2))));
11490 else if (TREE_CODE (TREE_OPERAND (incr, 1)) == NOP_EXPR
11491 && (TREE_CODE (TREE_OPERAND (incr, 2)) == PLUS_EXPR
11492 || (TREE_CODE (TREE_OPERAND (incr, 2)) == MINUS_EXPR)))
11494 tree rhs = TREE_OPERAND (incr, 2);
11495 incr = build2 (MODIFY_EXPR, TREE_TYPE (decl),
11496 RECUR (TREE_OPERAND (incr, 0)),
11497 build2 (TREE_CODE (rhs), TREE_TYPE (decl),
11498 RECUR (TREE_OPERAND (rhs, 0)),
11499 RECUR (TREE_OPERAND (rhs, 1))));
11502 incr = RECUR (incr);
11505 incr = RECUR (incr);
11509 TREE_VEC_ELT (declv, i) = decl;
11510 TREE_VEC_ELT (initv, i) = init;
11511 TREE_VEC_ELT (condv, i) = cond;
11512 TREE_VEC_ELT (incrv, i) = incr;
11516 /* Like tsubst_copy for expressions, etc. but also does semantic
11520 tsubst_expr (tree t, tree args, tsubst_flags_t complain, tree in_decl,
11521 bool integral_constant_expression_p)
11523 #define RECUR(NODE) \
11524 tsubst_expr ((NODE), args, complain, in_decl, \
11525 integral_constant_expression_p)
11529 if (t == NULL_TREE || t == error_mark_node)
11532 if (EXPR_HAS_LOCATION (t))
11533 input_location = EXPR_LOCATION (t);
11534 if (STATEMENT_CODE_P (TREE_CODE (t)))
11535 current_stmt_tree ()->stmts_are_full_exprs_p = STMT_IS_FULL_EXPR_P (t);
11537 switch (TREE_CODE (t))
11539 case STATEMENT_LIST:
11541 tree_stmt_iterator i;
11542 for (i = tsi_start (t); !tsi_end_p (i); tsi_next (&i))
11543 RECUR (tsi_stmt (i));
11547 case CTOR_INITIALIZER:
11548 finish_mem_initializers (tsubst_initializer_list
11549 (TREE_OPERAND (t, 0), args));
11553 finish_return_stmt (RECUR (TREE_OPERAND (t, 0)));
11557 tmp = RECUR (EXPR_STMT_EXPR (t));
11558 if (EXPR_STMT_STMT_EXPR_RESULT (t))
11559 finish_stmt_expr_expr (tmp, cur_stmt_expr);
11561 finish_expr_stmt (tmp);
11565 do_using_directive (RECUR (USING_STMT_NAMESPACE (t)));
11573 decl = DECL_EXPR_DECL (t);
11574 if (TREE_CODE (decl) == LABEL_DECL)
11575 finish_label_decl (DECL_NAME (decl));
11576 else if (TREE_CODE (decl) == USING_DECL)
11578 tree scope = USING_DECL_SCOPE (decl);
11579 tree name = DECL_NAME (decl);
11582 scope = RECUR (scope);
11583 decl = lookup_qualified_name (scope, name,
11584 /*is_type_p=*/false,
11585 /*complain=*/false);
11586 if (decl == error_mark_node || TREE_CODE (decl) == TREE_LIST)
11587 qualified_name_lookup_error (scope, name, decl, input_location);
11589 do_local_using_decl (decl, scope, name);
11593 init = DECL_INITIAL (decl);
11594 decl = tsubst (decl, args, complain, in_decl);
11595 if (decl != error_mark_node)
11597 /* By marking the declaration as instantiated, we avoid
11598 trying to instantiate it. Since instantiate_decl can't
11599 handle local variables, and since we've already done
11600 all that needs to be done, that's the right thing to
11602 if (TREE_CODE (decl) == VAR_DECL)
11603 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
11604 if (TREE_CODE (decl) == VAR_DECL
11605 && ANON_AGGR_TYPE_P (TREE_TYPE (decl)))
11606 /* Anonymous aggregates are a special case. */
11607 finish_anon_union (decl);
11610 maybe_push_decl (decl);
11611 if (TREE_CODE (decl) == VAR_DECL
11612 && DECL_PRETTY_FUNCTION_P (decl))
11614 /* For __PRETTY_FUNCTION__ we have to adjust the
11616 const char *const name
11617 = cxx_printable_name (current_function_decl, 2);
11618 init = cp_fname_init (name, &TREE_TYPE (decl));
11622 tree t = RECUR (init);
11625 /* If we had an initializer but it
11626 instantiated to nothing,
11627 value-initialize the object. This will
11628 only occur when the initializer was a
11629 pack expansion where the parameter packs
11630 used in that expansion were of length
11632 init = build_value_init (TREE_TYPE (decl));
11637 cp_finish_decl (decl, init, false, NULL_TREE, 0);
11642 /* A DECL_EXPR can also be used as an expression, in the condition
11643 clause of an if/for/while construct. */
11648 stmt = begin_for_stmt ();
11649 RECUR (FOR_INIT_STMT (t));
11650 finish_for_init_stmt (stmt);
11651 tmp = RECUR (FOR_COND (t));
11652 finish_for_cond (tmp, stmt);
11653 tmp = RECUR (FOR_EXPR (t));
11654 finish_for_expr (tmp, stmt);
11655 RECUR (FOR_BODY (t));
11656 finish_for_stmt (stmt);
11660 stmt = begin_while_stmt ();
11661 tmp = RECUR (WHILE_COND (t));
11662 finish_while_stmt_cond (tmp, stmt);
11663 RECUR (WHILE_BODY (t));
11664 finish_while_stmt (stmt);
11668 stmt = begin_do_stmt ();
11669 RECUR (DO_BODY (t));
11670 finish_do_body (stmt);
11671 tmp = RECUR (DO_COND (t));
11672 finish_do_stmt (tmp, stmt);
11676 stmt = begin_if_stmt ();
11677 tmp = RECUR (IF_COND (t));
11678 finish_if_stmt_cond (tmp, stmt);
11679 RECUR (THEN_CLAUSE (t));
11680 finish_then_clause (stmt);
11682 if (ELSE_CLAUSE (t))
11684 begin_else_clause (stmt);
11685 RECUR (ELSE_CLAUSE (t));
11686 finish_else_clause (stmt);
11689 finish_if_stmt (stmt);
11693 if (BIND_EXPR_BODY_BLOCK (t))
11694 stmt = begin_function_body ();
11696 stmt = begin_compound_stmt (BIND_EXPR_TRY_BLOCK (t)
11697 ? BCS_TRY_BLOCK : 0);
11699 RECUR (BIND_EXPR_BODY (t));
11701 if (BIND_EXPR_BODY_BLOCK (t))
11702 finish_function_body (stmt);
11704 finish_compound_stmt (stmt);
11708 finish_break_stmt ();
11711 case CONTINUE_STMT:
11712 finish_continue_stmt ();
11716 stmt = begin_switch_stmt ();
11717 tmp = RECUR (SWITCH_STMT_COND (t));
11718 finish_switch_cond (tmp, stmt);
11719 RECUR (SWITCH_STMT_BODY (t));
11720 finish_switch_stmt (stmt);
11723 case CASE_LABEL_EXPR:
11724 finish_case_label (EXPR_LOCATION (t),
11725 RECUR (CASE_LOW (t)),
11726 RECUR (CASE_HIGH (t)));
11731 tree decl = LABEL_EXPR_LABEL (t);
11734 label = finish_label_stmt (DECL_NAME (decl));
11735 if (DECL_ATTRIBUTES (decl) != NULL_TREE)
11736 cplus_decl_attributes (&label, DECL_ATTRIBUTES (decl), 0);
11741 tmp = GOTO_DESTINATION (t);
11742 if (TREE_CODE (tmp) != LABEL_DECL)
11743 /* Computed goto's must be tsubst'd into. On the other hand,
11744 non-computed gotos must not be; the identifier in question
11745 will have no binding. */
11748 tmp = DECL_NAME (tmp);
11749 finish_goto_stmt (tmp);
11753 tmp = finish_asm_stmt
11754 (ASM_VOLATILE_P (t),
11755 RECUR (ASM_STRING (t)),
11756 tsubst_copy_asm_operands (ASM_OUTPUTS (t), args, complain, in_decl),
11757 tsubst_copy_asm_operands (ASM_INPUTS (t), args, complain, in_decl),
11758 tsubst_copy_asm_operands (ASM_CLOBBERS (t), args, complain, in_decl),
11759 tsubst_copy_asm_operands (ASM_LABELS (t), args, complain, in_decl));
11761 tree asm_expr = tmp;
11762 if (TREE_CODE (asm_expr) == CLEANUP_POINT_EXPR)
11763 asm_expr = TREE_OPERAND (asm_expr, 0);
11764 ASM_INPUT_P (asm_expr) = ASM_INPUT_P (t);
11771 stmt = begin_try_block ();
11772 RECUR (TRY_STMTS (t));
11773 finish_cleanup_try_block (stmt);
11774 finish_cleanup (RECUR (TRY_HANDLERS (t)), stmt);
11778 tree compound_stmt = NULL_TREE;
11780 if (FN_TRY_BLOCK_P (t))
11781 stmt = begin_function_try_block (&compound_stmt);
11783 stmt = begin_try_block ();
11785 RECUR (TRY_STMTS (t));
11787 if (FN_TRY_BLOCK_P (t))
11788 finish_function_try_block (stmt);
11790 finish_try_block (stmt);
11792 RECUR (TRY_HANDLERS (t));
11793 if (FN_TRY_BLOCK_P (t))
11794 finish_function_handler_sequence (stmt, compound_stmt);
11796 finish_handler_sequence (stmt);
11802 tree decl = HANDLER_PARMS (t);
11806 decl = tsubst (decl, args, complain, in_decl);
11807 /* Prevent instantiate_decl from trying to instantiate
11808 this variable. We've already done all that needs to be
11810 if (decl != error_mark_node)
11811 DECL_TEMPLATE_INSTANTIATED (decl) = 1;
11813 stmt = begin_handler ();
11814 finish_handler_parms (decl, stmt);
11815 RECUR (HANDLER_BODY (t));
11816 finish_handler (stmt);
11821 tsubst (TREE_TYPE (t), args, complain, NULL_TREE);
11824 case STATIC_ASSERT:
11827 tsubst_expr (STATIC_ASSERT_CONDITION (t),
11830 /*integral_constant_expression_p=*/true);
11831 finish_static_assert (condition,
11832 STATIC_ASSERT_MESSAGE (t),
11833 STATIC_ASSERT_SOURCE_LOCATION (t),
11834 /*member_p=*/false);
11839 tmp = tsubst_omp_clauses (OMP_PARALLEL_CLAUSES (t),
11840 args, complain, in_decl);
11841 stmt = begin_omp_parallel ();
11842 RECUR (OMP_PARALLEL_BODY (t));
11843 OMP_PARALLEL_COMBINED (finish_omp_parallel (tmp, stmt))
11844 = OMP_PARALLEL_COMBINED (t);
11848 tmp = tsubst_omp_clauses (OMP_TASK_CLAUSES (t),
11849 args, complain, in_decl);
11850 stmt = begin_omp_task ();
11851 RECUR (OMP_TASK_BODY (t));
11852 finish_omp_task (tmp, stmt);
11857 tree clauses, body, pre_body;
11858 tree declv, initv, condv, incrv;
11861 clauses = tsubst_omp_clauses (OMP_FOR_CLAUSES (t),
11862 args, complain, in_decl);
11863 declv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
11864 initv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
11865 condv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
11866 incrv = make_tree_vec (TREE_VEC_LENGTH (OMP_FOR_INIT (t)));
11868 for (i = 0; i < TREE_VEC_LENGTH (OMP_FOR_INIT (t)); i++)
11869 tsubst_omp_for_iterator (t, i, declv, initv, condv, incrv,
11870 &clauses, args, complain, in_decl,
11871 integral_constant_expression_p);
11873 stmt = begin_omp_structured_block ();
11875 for (i = 0; i < TREE_VEC_LENGTH (initv); i++)
11876 if (TREE_VEC_ELT (initv, i) == NULL
11877 || TREE_CODE (TREE_VEC_ELT (initv, i)) != DECL_EXPR)
11878 TREE_VEC_ELT (initv, i) = RECUR (TREE_VEC_ELT (initv, i));
11879 else if (CLASS_TYPE_P (TREE_TYPE (TREE_VEC_ELT (initv, i))))
11881 tree init = RECUR (TREE_VEC_ELT (initv, i));
11882 gcc_assert (init == TREE_VEC_ELT (declv, i));
11883 TREE_VEC_ELT (initv, i) = NULL_TREE;
11887 tree decl_expr = TREE_VEC_ELT (initv, i);
11888 tree init = DECL_INITIAL (DECL_EXPR_DECL (decl_expr));
11889 gcc_assert (init != NULL);
11890 TREE_VEC_ELT (initv, i) = RECUR (init);
11891 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = NULL;
11893 DECL_INITIAL (DECL_EXPR_DECL (decl_expr)) = init;
11896 pre_body = push_stmt_list ();
11897 RECUR (OMP_FOR_PRE_BODY (t));
11898 pre_body = pop_stmt_list (pre_body);
11900 body = push_stmt_list ();
11901 RECUR (OMP_FOR_BODY (t));
11902 body = pop_stmt_list (body);
11904 t = finish_omp_for (EXPR_LOCATION (t), declv, initv, condv, incrv,
11905 body, pre_body, clauses);
11907 add_stmt (finish_omp_structured_block (stmt));
11913 tmp = tsubst_omp_clauses (OMP_CLAUSES (t), args, complain, in_decl);
11914 stmt = push_stmt_list ();
11915 RECUR (OMP_BODY (t));
11916 stmt = pop_stmt_list (stmt);
11919 OMP_BODY (t) = stmt;
11920 OMP_CLAUSES (t) = tmp;
11928 stmt = push_stmt_list ();
11929 RECUR (OMP_BODY (t));
11930 stmt = pop_stmt_list (stmt);
11933 OMP_BODY (t) = stmt;
11938 gcc_assert (OMP_ATOMIC_DEPENDENT_P (t));
11940 tree op1 = TREE_OPERAND (t, 1);
11941 tree lhs = RECUR (TREE_OPERAND (op1, 0));
11942 tree rhs = RECUR (TREE_OPERAND (op1, 1));
11943 finish_omp_atomic (TREE_CODE (op1), lhs, rhs);
11947 case EXPR_PACK_EXPANSION:
11948 error ("invalid use of pack expansion expression");
11949 return error_mark_node;
11951 case NONTYPE_ARGUMENT_PACK:
11952 error ("use %<...%> to expand argument pack");
11953 return error_mark_node;
11956 gcc_assert (!STATEMENT_CODE_P (TREE_CODE (t)));
11958 return tsubst_copy_and_build (t, args, complain, in_decl,
11959 /*function_p=*/false,
11960 integral_constant_expression_p);
11967 /* T is a postfix-expression that is not being used in a function
11968 call. Return the substituted version of T. */
11971 tsubst_non_call_postfix_expression (tree t, tree args,
11972 tsubst_flags_t complain,
11975 if (TREE_CODE (t) == SCOPE_REF)
11976 t = tsubst_qualified_id (t, args, complain, in_decl,
11977 /*done=*/false, /*address_p=*/false);
11979 t = tsubst_copy_and_build (t, args, complain, in_decl,
11980 /*function_p=*/false,
11981 /*integral_constant_expression_p=*/false);
11986 /* Like tsubst but deals with expressions and performs semantic
11987 analysis. FUNCTION_P is true if T is the "F" in "F (ARGS)". */
11990 tsubst_copy_and_build (tree t,
11992 tsubst_flags_t complain,
11995 bool integral_constant_expression_p)
11997 #define RECUR(NODE) \
11998 tsubst_copy_and_build (NODE, args, complain, in_decl, \
11999 /*function_p=*/false, \
12000 integral_constant_expression_p)
12004 if (t == NULL_TREE || t == error_mark_node)
12007 switch (TREE_CODE (t))
12011 /* Fall through. */
12012 case IDENTIFIER_NODE:
12016 bool non_integral_constant_expression_p;
12017 const char *error_msg;
12019 if (IDENTIFIER_TYPENAME_P (t))
12021 tree new_type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12022 t = mangle_conv_op_name_for_type (new_type);
12025 /* Look up the name. */
12026 decl = lookup_name (t);
12028 /* By convention, expressions use ERROR_MARK_NODE to indicate
12029 failure, not NULL_TREE. */
12030 if (decl == NULL_TREE)
12031 decl = error_mark_node;
12033 decl = finish_id_expression (t, decl, NULL_TREE,
12035 integral_constant_expression_p,
12036 /*allow_non_integral_constant_expression_p=*/false,
12037 &non_integral_constant_expression_p,
12038 /*template_p=*/false,
12040 /*address_p=*/false,
12041 /*template_arg_p=*/false,
12046 if (!function_p && TREE_CODE (decl) == IDENTIFIER_NODE)
12047 decl = unqualified_name_lookup_error (decl);
12051 case TEMPLATE_ID_EXPR:
12054 tree templ = RECUR (TREE_OPERAND (t, 0));
12055 tree targs = TREE_OPERAND (t, 1);
12058 targs = tsubst_template_args (targs, args, complain, in_decl);
12060 if (TREE_CODE (templ) == COMPONENT_REF)
12062 object = TREE_OPERAND (templ, 0);
12063 templ = TREE_OPERAND (templ, 1);
12066 object = NULL_TREE;
12067 templ = lookup_template_function (templ, targs);
12070 return build3 (COMPONENT_REF, TREE_TYPE (templ),
12071 object, templ, NULL_TREE);
12073 return baselink_for_fns (templ);
12078 tree r = RECUR (TREE_OPERAND (t, 0));
12080 if (REFERENCE_REF_P (t))
12082 /* A type conversion to reference type will be enclosed in
12083 such an indirect ref, but the substitution of the cast
12084 will have also added such an indirect ref. */
12085 if (TREE_CODE (TREE_TYPE (r)) == REFERENCE_TYPE)
12086 r = convert_from_reference (r);
12089 r = build_x_indirect_ref (r, RO_UNARY_STAR, complain);
12095 (tsubst (TREE_TYPE (t), args, complain, in_decl),
12096 RECUR (TREE_OPERAND (t, 0)));
12099 case REINTERPRET_CAST_EXPR:
12100 case CONST_CAST_EXPR:
12101 case DYNAMIC_CAST_EXPR:
12102 case STATIC_CAST_EXPR:
12107 type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12108 if (integral_constant_expression_p
12109 && !cast_valid_in_integral_constant_expression_p (type))
12111 if (complain & tf_error)
12112 error ("a cast to a type other than an integral or "
12113 "enumeration type cannot appear in a constant-expression");
12114 return error_mark_node;
12117 op = RECUR (TREE_OPERAND (t, 0));
12119 switch (TREE_CODE (t))
12122 return build_functional_cast (type, op, complain);
12123 case REINTERPRET_CAST_EXPR:
12124 return build_reinterpret_cast (type, op, complain);
12125 case CONST_CAST_EXPR:
12126 return build_const_cast (type, op, complain);
12127 case DYNAMIC_CAST_EXPR:
12128 return build_dynamic_cast (type, op, complain);
12129 case STATIC_CAST_EXPR:
12130 return build_static_cast (type, op, complain);
12132 gcc_unreachable ();
12136 case POSTDECREMENT_EXPR:
12137 case POSTINCREMENT_EXPR:
12138 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
12139 args, complain, in_decl);
12140 return build_x_unary_op (TREE_CODE (t), op1, complain);
12142 case PREDECREMENT_EXPR:
12143 case PREINCREMENT_EXPR:
12147 case TRUTH_NOT_EXPR:
12148 case UNARY_PLUS_EXPR: /* Unary + */
12149 case REALPART_EXPR:
12150 case IMAGPART_EXPR:
12151 return build_x_unary_op (TREE_CODE (t), RECUR (TREE_OPERAND (t, 0)),
12155 op1 = TREE_OPERAND (t, 0);
12156 if (TREE_CODE (op1) == SCOPE_REF)
12157 op1 = tsubst_qualified_id (op1, args, complain, in_decl,
12158 /*done=*/true, /*address_p=*/true);
12160 op1 = tsubst_non_call_postfix_expression (op1, args, complain,
12162 if (TREE_CODE (op1) == LABEL_DECL)
12163 return finish_label_address_expr (DECL_NAME (op1),
12164 EXPR_LOCATION (op1));
12165 return build_x_unary_op (ADDR_EXPR, op1, complain);
12170 case TRUNC_DIV_EXPR:
12171 case CEIL_DIV_EXPR:
12172 case FLOOR_DIV_EXPR:
12173 case ROUND_DIV_EXPR:
12174 case EXACT_DIV_EXPR:
12178 case TRUNC_MOD_EXPR:
12179 case FLOOR_MOD_EXPR:
12180 case TRUTH_ANDIF_EXPR:
12181 case TRUTH_ORIF_EXPR:
12182 case TRUTH_AND_EXPR:
12183 case TRUTH_OR_EXPR:
12198 return build_x_binary_op
12200 RECUR (TREE_OPERAND (t, 0)),
12201 (TREE_NO_WARNING (TREE_OPERAND (t, 0))
12203 : TREE_CODE (TREE_OPERAND (t, 0))),
12204 RECUR (TREE_OPERAND (t, 1)),
12205 (TREE_NO_WARNING (TREE_OPERAND (t, 1))
12207 : TREE_CODE (TREE_OPERAND (t, 1))),
12208 /*overloaded_p=*/NULL,
12212 return tsubst_qualified_id (t, args, complain, in_decl, /*done=*/true,
12213 /*address_p=*/false);
12215 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
12216 args, complain, in_decl);
12217 return build_x_array_ref (op1, RECUR (TREE_OPERAND (t, 1)), complain);
12220 if (PACK_EXPANSION_P (TREE_OPERAND (t, 0)))
12221 return tsubst_copy (t, args, complain, in_decl);
12225 op1 = TREE_OPERAND (t, 0);
12228 /* When there are no ARGS, we are trying to evaluate a
12229 non-dependent expression from the parser. Trying to do
12230 the substitutions may not work. */
12232 op1 = TREE_TYPE (op1);
12236 ++cp_unevaluated_operand;
12237 ++c_inhibit_evaluation_warnings;
12238 op1 = tsubst_copy_and_build (op1, args, complain, in_decl,
12239 /*function_p=*/false,
12240 /*integral_constant_expression_p=*/false);
12241 --cp_unevaluated_operand;
12242 --c_inhibit_evaluation_warnings;
12245 return cxx_sizeof_or_alignof_type (op1, TREE_CODE (t),
12246 complain & tf_error);
12248 return cxx_sizeof_or_alignof_expr (op1, TREE_CODE (t),
12249 complain & tf_error);
12253 tree r = build_x_modify_expr
12254 (RECUR (TREE_OPERAND (t, 0)),
12255 TREE_CODE (TREE_OPERAND (t, 1)),
12256 RECUR (TREE_OPERAND (t, 2)),
12258 /* TREE_NO_WARNING must be set if either the expression was
12259 parenthesized or it uses an operator such as >>= rather
12260 than plain assignment. In the former case, it was already
12261 set and must be copied. In the latter case,
12262 build_x_modify_expr sets it and it must not be reset
12264 if (TREE_NO_WARNING (t))
12265 TREE_NO_WARNING (r) = TREE_NO_WARNING (t);
12270 op1 = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
12271 args, complain, in_decl);
12272 /* Remember that there was a reference to this entity. */
12275 return build_x_arrow (op1);
12279 tree placement = RECUR (TREE_OPERAND (t, 0));
12280 tree init = RECUR (TREE_OPERAND (t, 3));
12281 VEC(tree,gc) *placement_vec;
12282 VEC(tree,gc) *init_vec;
12285 if (placement == NULL_TREE)
12286 placement_vec = NULL;
12289 placement_vec = make_tree_vector ();
12290 for (; placement != NULL_TREE; placement = TREE_CHAIN (placement))
12291 VEC_safe_push (tree, gc, placement_vec, TREE_VALUE (placement));
12294 /* If there was an initializer in the original tree, but it
12295 instantiated to an empty list, then we should pass a
12296 non-NULL empty vector to tell build_new that it was an
12297 empty initializer() rather than no initializer. This can
12298 only happen when the initializer is a pack expansion whose
12299 parameter packs are of length zero. */
12300 if (init == NULL_TREE && TREE_OPERAND (t, 3) == NULL_TREE)
12304 init_vec = make_tree_vector ();
12305 if (init == void_zero_node)
12306 gcc_assert (init_vec != NULL);
12309 for (; init != NULL_TREE; init = TREE_CHAIN (init))
12310 VEC_safe_push (tree, gc, init_vec, TREE_VALUE (init));
12314 ret = build_new (&placement_vec,
12315 RECUR (TREE_OPERAND (t, 1)),
12316 RECUR (TREE_OPERAND (t, 2)),
12318 NEW_EXPR_USE_GLOBAL (t),
12321 if (placement_vec != NULL)
12322 release_tree_vector (placement_vec);
12323 if (init_vec != NULL)
12324 release_tree_vector (init_vec);
12330 return delete_sanity
12331 (RECUR (TREE_OPERAND (t, 0)),
12332 RECUR (TREE_OPERAND (t, 1)),
12333 DELETE_EXPR_USE_VEC (t),
12334 DELETE_EXPR_USE_GLOBAL (t));
12336 case COMPOUND_EXPR:
12337 return build_x_compound_expr (RECUR (TREE_OPERAND (t, 0)),
12338 RECUR (TREE_OPERAND (t, 1)),
12344 VEC(tree,gc) *call_args;
12345 unsigned int nargs, i;
12350 function = CALL_EXPR_FN (t);
12351 /* When we parsed the expression, we determined whether or
12352 not Koenig lookup should be performed. */
12353 koenig_p = KOENIG_LOOKUP_P (t);
12354 if (TREE_CODE (function) == SCOPE_REF)
12356 qualified_p = true;
12357 function = tsubst_qualified_id (function, args, complain, in_decl,
12359 /*address_p=*/false);
12363 if (TREE_CODE (function) == COMPONENT_REF)
12365 tree op = TREE_OPERAND (function, 1);
12367 qualified_p = (TREE_CODE (op) == SCOPE_REF
12368 || (BASELINK_P (op)
12369 && BASELINK_QUALIFIED_P (op)));
12372 qualified_p = false;
12374 function = tsubst_copy_and_build (function, args, complain,
12377 integral_constant_expression_p);
12379 if (BASELINK_P (function))
12380 qualified_p = true;
12383 nargs = call_expr_nargs (t);
12384 call_args = make_tree_vector ();
12385 for (i = 0; i < nargs; ++i)
12387 tree arg = CALL_EXPR_ARG (t, i);
12389 if (!PACK_EXPANSION_P (arg))
12390 VEC_safe_push (tree, gc, call_args,
12391 RECUR (CALL_EXPR_ARG (t, i)));
12394 /* Expand the pack expansion and push each entry onto
12396 arg = tsubst_pack_expansion (arg, args, complain, in_decl);
12397 if (TREE_CODE (arg) == TREE_VEC)
12399 unsigned int len, j;
12401 len = TREE_VEC_LENGTH (arg);
12402 for (j = 0; j < len; ++j)
12404 tree value = TREE_VEC_ELT (arg, j);
12405 if (value != NULL_TREE)
12406 value = convert_from_reference (value);
12407 VEC_safe_push (tree, gc, call_args, value);
12412 /* A partial substitution. Add one entry. */
12413 VEC_safe_push (tree, gc, call_args, arg);
12418 /* We do not perform argument-dependent lookup if normal
12419 lookup finds a non-function, in accordance with the
12420 expected resolution of DR 218. */
12422 && ((is_overloaded_fn (function)
12423 /* If lookup found a member function, the Koenig lookup is
12424 not appropriate, even if an unqualified-name was used
12425 to denote the function. */
12426 && !DECL_FUNCTION_MEMBER_P (get_first_fn (function)))
12427 || TREE_CODE (function) == IDENTIFIER_NODE)
12428 /* Only do this when substitution turns a dependent call
12429 into a non-dependent call. */
12430 && type_dependent_expression_p_push (t)
12431 && !any_type_dependent_arguments_p (call_args))
12432 function = perform_koenig_lookup (function, call_args);
12434 if (TREE_CODE (function) == IDENTIFIER_NODE)
12436 unqualified_name_lookup_error (function);
12437 release_tree_vector (call_args);
12438 return error_mark_node;
12441 /* Remember that there was a reference to this entity. */
12442 if (DECL_P (function))
12443 mark_used (function);
12445 if (TREE_CODE (function) == OFFSET_REF)
12446 ret = build_offset_ref_call_from_tree (function, &call_args);
12447 else if (TREE_CODE (function) == COMPONENT_REF)
12449 if (!BASELINK_P (TREE_OPERAND (function, 1)))
12450 ret = finish_call_expr (function, &call_args,
12451 /*disallow_virtual=*/false,
12452 /*koenig_p=*/false,
12455 ret = (build_new_method_call
12456 (TREE_OPERAND (function, 0),
12457 TREE_OPERAND (function, 1),
12458 &call_args, NULL_TREE,
12459 qualified_p ? LOOKUP_NONVIRTUAL : LOOKUP_NORMAL,
12464 ret = finish_call_expr (function, &call_args,
12465 /*disallow_virtual=*/qualified_p,
12469 release_tree_vector (call_args);
12475 return build_x_conditional_expr
12476 (RECUR (TREE_OPERAND (t, 0)),
12477 RECUR (TREE_OPERAND (t, 1)),
12478 RECUR (TREE_OPERAND (t, 2)),
12481 case PSEUDO_DTOR_EXPR:
12482 return finish_pseudo_destructor_expr
12483 (RECUR (TREE_OPERAND (t, 0)),
12484 RECUR (TREE_OPERAND (t, 1)),
12485 RECUR (TREE_OPERAND (t, 2)));
12489 tree purpose, value, chain;
12491 if (t == void_list_node)
12494 if ((TREE_PURPOSE (t) && PACK_EXPANSION_P (TREE_PURPOSE (t)))
12495 || (TREE_VALUE (t) && PACK_EXPANSION_P (TREE_VALUE (t))))
12497 /* We have pack expansions, so expand those and
12498 create a new list out of it. */
12499 tree purposevec = NULL_TREE;
12500 tree valuevec = NULL_TREE;
12504 /* Expand the argument expressions. */
12505 if (TREE_PURPOSE (t))
12506 purposevec = tsubst_pack_expansion (TREE_PURPOSE (t), args,
12507 complain, in_decl);
12508 if (TREE_VALUE (t))
12509 valuevec = tsubst_pack_expansion (TREE_VALUE (t), args,
12510 complain, in_decl);
12512 /* Build the rest of the list. */
12513 chain = TREE_CHAIN (t);
12514 if (chain && chain != void_type_node)
12515 chain = RECUR (chain);
12517 /* Determine the number of arguments. */
12518 if (purposevec && TREE_CODE (purposevec) == TREE_VEC)
12520 len = TREE_VEC_LENGTH (purposevec);
12521 gcc_assert (!valuevec || len == TREE_VEC_LENGTH (valuevec));
12523 else if (TREE_CODE (valuevec) == TREE_VEC)
12524 len = TREE_VEC_LENGTH (valuevec);
12527 /* Since we only performed a partial substitution into
12528 the argument pack, we only return a single list
12530 if (purposevec == TREE_PURPOSE (t)
12531 && valuevec == TREE_VALUE (t)
12532 && chain == TREE_CHAIN (t))
12535 return tree_cons (purposevec, valuevec, chain);
12538 /* Convert the argument vectors into a TREE_LIST */
12542 /* Grab the Ith values. */
12544 purpose = purposevec ? TREE_VEC_ELT (purposevec, i)
12547 = valuevec ? convert_from_reference (TREE_VEC_ELT (valuevec, i))
12550 /* Build the list (backwards). */
12551 chain = tree_cons (purpose, value, chain);
12557 purpose = TREE_PURPOSE (t);
12559 purpose = RECUR (purpose);
12560 value = TREE_VALUE (t);
12562 value = RECUR (value);
12563 chain = TREE_CHAIN (t);
12564 if (chain && chain != void_type_node)
12565 chain = RECUR (chain);
12566 if (purpose == TREE_PURPOSE (t)
12567 && value == TREE_VALUE (t)
12568 && chain == TREE_CHAIN (t))
12570 return tree_cons (purpose, value, chain);
12573 case COMPONENT_REF:
12579 object = tsubst_non_call_postfix_expression (TREE_OPERAND (t, 0),
12580 args, complain, in_decl);
12581 /* Remember that there was a reference to this entity. */
12582 if (DECL_P (object))
12583 mark_used (object);
12584 object_type = TREE_TYPE (object);
12586 member = TREE_OPERAND (t, 1);
12587 if (BASELINK_P (member))
12588 member = tsubst_baselink (member,
12589 non_reference (TREE_TYPE (object)),
12590 args, complain, in_decl);
12592 member = tsubst_copy (member, args, complain, in_decl);
12593 if (member == error_mark_node)
12594 return error_mark_node;
12596 if (object_type && !CLASS_TYPE_P (object_type))
12598 if (SCALAR_TYPE_P (object_type))
12600 tree s = NULL_TREE;
12601 tree dtor = member;
12603 if (TREE_CODE (dtor) == SCOPE_REF)
12605 s = TREE_OPERAND (dtor, 0);
12606 dtor = TREE_OPERAND (dtor, 1);
12608 if (TREE_CODE (dtor) == BIT_NOT_EXPR)
12610 dtor = TREE_OPERAND (dtor, 0);
12612 return finish_pseudo_destructor_expr (object, s, dtor);
12616 else if (TREE_CODE (member) == SCOPE_REF
12617 && TREE_CODE (TREE_OPERAND (member, 1)) == TEMPLATE_ID_EXPR)
12622 /* Lookup the template functions now that we know what the
12624 tmpl = TREE_OPERAND (TREE_OPERAND (member, 1), 0);
12625 args = TREE_OPERAND (TREE_OPERAND (member, 1), 1);
12626 member = lookup_qualified_name (TREE_OPERAND (member, 0), tmpl,
12627 /*is_type_p=*/false,
12628 /*complain=*/false);
12629 if (BASELINK_P (member))
12631 BASELINK_FUNCTIONS (member)
12632 = build_nt (TEMPLATE_ID_EXPR, BASELINK_FUNCTIONS (member),
12634 member = (adjust_result_of_qualified_name_lookup
12635 (member, BINFO_TYPE (BASELINK_BINFO (member)),
12640 qualified_name_lookup_error (object_type, tmpl, member,
12642 return error_mark_node;
12645 else if (TREE_CODE (member) == SCOPE_REF
12646 && !CLASS_TYPE_P (TREE_OPERAND (member, 0))
12647 && TREE_CODE (TREE_OPERAND (member, 0)) != NAMESPACE_DECL)
12649 if (complain & tf_error)
12651 if (TYPE_P (TREE_OPERAND (member, 0)))
12652 error ("%qT is not a class or namespace",
12653 TREE_OPERAND (member, 0));
12655 error ("%qD is not a class or namespace",
12656 TREE_OPERAND (member, 0));
12658 return error_mark_node;
12660 else if (TREE_CODE (member) == FIELD_DECL)
12661 return finish_non_static_data_member (member, object, NULL_TREE);
12663 return finish_class_member_access_expr (object, member,
12664 /*template_p=*/false,
12670 (RECUR (TREE_OPERAND (t, 0)));
12674 VEC(constructor_elt,gc) *n;
12675 constructor_elt *ce;
12676 unsigned HOST_WIDE_INT idx;
12677 tree type = tsubst (TREE_TYPE (t), args, complain, in_decl);
12678 bool process_index_p;
12680 bool need_copy_p = false;
12683 if (type == error_mark_node)
12684 return error_mark_node;
12686 /* digest_init will do the wrong thing if we let it. */
12687 if (type && TYPE_PTRMEMFUNC_P (type))
12690 /* We do not want to process the index of aggregate
12691 initializers as they are identifier nodes which will be
12692 looked up by digest_init. */
12693 process_index_p = !(type && MAYBE_CLASS_TYPE_P (type));
12695 n = VEC_copy (constructor_elt, gc, CONSTRUCTOR_ELTS (t));
12696 newlen = VEC_length (constructor_elt, n);
12697 for (idx = 0; VEC_iterate (constructor_elt, n, idx, ce); idx++)
12699 if (ce->index && process_index_p)
12700 ce->index = RECUR (ce->index);
12702 if (PACK_EXPANSION_P (ce->value))
12704 /* Substitute into the pack expansion. */
12705 ce->value = tsubst_pack_expansion (ce->value, args, complain,
12708 if (ce->value == error_mark_node)
12710 else if (TREE_VEC_LENGTH (ce->value) == 1)
12711 /* Just move the argument into place. */
12712 ce->value = TREE_VEC_ELT (ce->value, 0);
12715 /* Update the length of the final CONSTRUCTOR
12716 arguments vector, and note that we will need to
12718 newlen = newlen + TREE_VEC_LENGTH (ce->value) - 1;
12719 need_copy_p = true;
12723 ce->value = RECUR (ce->value);
12728 VEC(constructor_elt,gc) *old_n = n;
12730 n = VEC_alloc (constructor_elt, gc, newlen);
12731 for (idx = 0; VEC_iterate (constructor_elt, old_n, idx, ce);
12734 if (TREE_CODE (ce->value) == TREE_VEC)
12736 int i, len = TREE_VEC_LENGTH (ce->value);
12737 for (i = 0; i < len; ++i)
12738 CONSTRUCTOR_APPEND_ELT (n, 0,
12739 TREE_VEC_ELT (ce->value, i));
12742 CONSTRUCTOR_APPEND_ELT (n, 0, ce->value);
12746 r = build_constructor (init_list_type_node, n);
12747 CONSTRUCTOR_IS_DIRECT_INIT (r) = CONSTRUCTOR_IS_DIRECT_INIT (t);
12749 if (TREE_HAS_CONSTRUCTOR (t))
12750 return finish_compound_literal (type, r);
12757 tree operand_0 = RECUR (TREE_OPERAND (t, 0));
12758 if (TYPE_P (operand_0))
12759 return get_typeid (operand_0);
12760 return build_typeid (operand_0);
12770 tree r = tsubst_copy (t, args, complain, in_decl);
12772 if (TREE_CODE (TREE_TYPE (t)) != REFERENCE_TYPE)
12773 /* If the original type was a reference, we'll be wrapped in
12774 the appropriate INDIRECT_REF. */
12775 r = convert_from_reference (r);
12780 return build_x_va_arg (RECUR (TREE_OPERAND (t, 0)),
12781 tsubst_copy (TREE_TYPE (t), args, complain,
12784 case OFFSETOF_EXPR:
12785 return finish_offsetof (RECUR (TREE_OPERAND (t, 0)));
12789 tree type1 = tsubst_copy (TRAIT_EXPR_TYPE1 (t), args,
12790 complain, in_decl);
12792 tree type2 = TRAIT_EXPR_TYPE2 (t);
12794 type2 = tsubst_copy (type2, args, complain, in_decl);
12796 return finish_trait_expr (TRAIT_EXPR_KIND (t), type1, type2);
12801 tree old_stmt_expr = cur_stmt_expr;
12802 tree stmt_expr = begin_stmt_expr ();
12804 cur_stmt_expr = stmt_expr;
12805 tsubst_expr (STMT_EXPR_STMT (t), args, complain, in_decl,
12806 integral_constant_expression_p);
12807 stmt_expr = finish_stmt_expr (stmt_expr, false);
12808 cur_stmt_expr = old_stmt_expr;
12810 /* If the resulting list of expression statement is empty,
12811 fold it further into void_zero_node. */
12812 if (empty_expr_stmt_p (stmt_expr))
12813 stmt_expr = void_zero_node;
12819 t = tsubst_copy (t, args, complain, in_decl);
12820 /* As in finish_id_expression, we resolve enumeration constants
12821 to their underlying values. */
12822 if (TREE_CODE (t) == CONST_DECL)
12824 used_types_insert (TREE_TYPE (t));
12825 return DECL_INITIAL (t);
12831 tree r = build_lambda_expr ();
12833 tree type = tsubst (TREE_TYPE (t), args, complain, NULL_TREE);
12834 TREE_TYPE (r) = type;
12835 CLASSTYPE_LAMBDA_EXPR (type) = r;
12837 LAMBDA_EXPR_LOCATION (r)
12838 = LAMBDA_EXPR_LOCATION (t);
12839 LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (r)
12840 = LAMBDA_EXPR_DEFAULT_CAPTURE_MODE (t);
12841 LAMBDA_EXPR_MUTABLE_P (r) = LAMBDA_EXPR_MUTABLE_P (t);
12842 LAMBDA_EXPR_DISCRIMINATOR (r)
12843 = (LAMBDA_EXPR_DISCRIMINATOR (t));
12844 LAMBDA_EXPR_CAPTURE_LIST (r)
12845 = RECUR (LAMBDA_EXPR_CAPTURE_LIST (t));
12846 LAMBDA_EXPR_THIS_CAPTURE (r)
12847 = RECUR (LAMBDA_EXPR_THIS_CAPTURE (t));
12848 LAMBDA_EXPR_EXTRA_SCOPE (r)
12849 = RECUR (LAMBDA_EXPR_EXTRA_SCOPE (t));
12851 /* Do this again now that LAMBDA_EXPR_EXTRA_SCOPE is set. */
12852 determine_visibility (TYPE_NAME (type));
12853 /* Now that we know visibility, instantiate the type so we have a
12854 declaration of the op() for later calls to lambda_function. */
12855 complete_type (type);
12857 type = tsubst (LAMBDA_EXPR_RETURN_TYPE (t), args, complain, in_decl);
12859 apply_lambda_return_type (r, type);
12861 return build_lambda_object (r);
12865 /* Handle Objective-C++ constructs, if appropriate. */
12868 = objcp_tsubst_copy_and_build (t, args, complain,
12869 in_decl, /*function_p=*/false);
12873 return tsubst_copy (t, args, complain, in_decl);
12879 /* Verify that the instantiated ARGS are valid. For type arguments,
12880 make sure that the type's linkage is ok. For non-type arguments,
12881 make sure they are constants if they are integral or enumerations.
12882 Emit an error under control of COMPLAIN, and return TRUE on error. */
12885 check_instantiated_arg (tree tmpl, tree t, tsubst_flags_t complain)
12887 if (ARGUMENT_PACK_P (t))
12889 tree vec = ARGUMENT_PACK_ARGS (t);
12890 int len = TREE_VEC_LENGTH (vec);
12891 bool result = false;
12894 for (i = 0; i < len; ++i)
12895 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (vec, i), complain))
12899 else if (TYPE_P (t))
12901 /* [basic.link]: A name with no linkage (notably, the name
12902 of a class or enumeration declared in a local scope)
12903 shall not be used to declare an entity with linkage.
12904 This implies that names with no linkage cannot be used as
12907 DR 757 relaxes this restriction for C++0x. */
12908 tree nt = (cxx_dialect > cxx98 ? NULL_TREE
12909 : no_linkage_check (t, /*relaxed_p=*/false));
12913 /* DR 488 makes use of a type with no linkage cause
12914 type deduction to fail. */
12915 if (complain & tf_error)
12917 if (TYPE_ANONYMOUS_P (nt))
12918 error ("%qT is/uses anonymous type", t);
12920 error ("template argument for %qD uses local type %qT",
12925 /* In order to avoid all sorts of complications, we do not
12926 allow variably-modified types as template arguments. */
12927 else if (variably_modified_type_p (t, NULL_TREE))
12929 if (complain & tf_error)
12930 error ("%qT is a variably modified type", t);
12934 /* A non-type argument of integral or enumerated type must be a
12936 else if (TREE_TYPE (t)
12937 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (t))
12938 && !TREE_CONSTANT (t))
12940 if (complain & tf_error)
12941 error ("integral expression %qE is not constant", t);
12948 check_instantiated_args (tree tmpl, tree args, tsubst_flags_t complain)
12950 int ix, len = DECL_NTPARMS (tmpl);
12951 bool result = false;
12953 for (ix = 0; ix != len; ix++)
12955 if (check_instantiated_arg (tmpl, TREE_VEC_ELT (args, ix), complain))
12958 if (result && (complain & tf_error))
12959 error (" trying to instantiate %qD", tmpl);
12963 /* Instantiate the indicated variable or function template TMPL with
12964 the template arguments in TARG_PTR. */
12967 instantiate_template (tree tmpl, tree orig_args, tsubst_flags_t complain)
12969 tree targ_ptr = orig_args;
12973 HOST_WIDE_INT saved_processing_template_decl;
12975 if (tmpl == error_mark_node)
12976 return error_mark_node;
12978 gcc_assert (TREE_CODE (tmpl) == TEMPLATE_DECL);
12980 /* If this function is a clone, handle it specially. */
12981 if (DECL_CLONED_FUNCTION_P (tmpl))
12986 /* Use DECL_ABSTRACT_ORIGIN because only FUNCTION_DECLs have
12987 DECL_CLONED_FUNCTION. */
12988 spec = instantiate_template (DECL_ABSTRACT_ORIGIN (tmpl),
12989 targ_ptr, complain);
12990 if (spec == error_mark_node)
12991 return error_mark_node;
12993 /* Look for the clone. */
12994 FOR_EACH_CLONE (clone, spec)
12995 if (DECL_NAME (clone) == DECL_NAME (tmpl))
12997 /* We should always have found the clone by now. */
12998 gcc_unreachable ();
13002 /* Check to see if we already have this specialization. */
13003 gen_tmpl = most_general_template (tmpl);
13004 if (tmpl != gen_tmpl)
13005 /* The TMPL is a partial instantiation. To get a full set of
13006 arguments we must add the arguments used to perform the
13007 partial instantiation. */
13008 targ_ptr = add_outermost_template_args (DECL_TI_ARGS (tmpl),
13011 /* It would be nice to avoid hashing here and then again in tsubst_decl,
13012 but it doesn't seem to be on the hot path. */
13013 spec = retrieve_specialization (gen_tmpl, targ_ptr, 0);
13015 gcc_assert (tmpl == gen_tmpl
13016 || ((fndecl = retrieve_specialization (tmpl, orig_args, 0))
13018 || fndecl == NULL_TREE);
13020 if (spec != NULL_TREE)
13023 if (check_instantiated_args (gen_tmpl, INNERMOST_TEMPLATE_ARGS (targ_ptr),
13025 return error_mark_node;
13027 /* We are building a FUNCTION_DECL, during which the access of its
13028 parameters and return types have to be checked. However this
13029 FUNCTION_DECL which is the desired context for access checking
13030 is not built yet. We solve this chicken-and-egg problem by
13031 deferring all checks until we have the FUNCTION_DECL. */
13032 push_deferring_access_checks (dk_deferred);
13034 /* Although PROCESSING_TEMPLATE_DECL may be true at this point
13035 (because, for example, we have encountered a non-dependent
13036 function call in the body of a template function and must now
13037 determine which of several overloaded functions will be called),
13038 within the instantiation itself we are not processing a
13040 saved_processing_template_decl = processing_template_decl;
13041 processing_template_decl = 0;
13042 /* Substitute template parameters to obtain the specialization. */
13043 fndecl = tsubst (DECL_TEMPLATE_RESULT (gen_tmpl),
13044 targ_ptr, complain, gen_tmpl);
13045 processing_template_decl = saved_processing_template_decl;
13046 if (fndecl == error_mark_node)
13047 return error_mark_node;
13049 /* Now we know the specialization, compute access previously
13051 push_access_scope (fndecl);
13053 /* Some typedefs referenced from within the template code need to be access
13054 checked at template instantiation time, i.e now. These types were
13055 added to the template at parsing time. Let's get those and perfom
13056 the acces checks then. */
13057 perform_typedefs_access_check (DECL_TEMPLATE_RESULT (tmpl), targ_ptr);
13058 perform_deferred_access_checks ();
13059 pop_access_scope (fndecl);
13060 pop_deferring_access_checks ();
13062 /* The DECL_TI_TEMPLATE should always be the immediate parent
13063 template, not the most general template. */
13064 DECL_TI_TEMPLATE (fndecl) = tmpl;
13066 /* If we've just instantiated the main entry point for a function,
13067 instantiate all the alternate entry points as well. We do this
13068 by cloning the instantiation of the main entry point, not by
13069 instantiating the template clones. */
13070 if (TREE_CHAIN (gen_tmpl) && DECL_CLONED_FUNCTION_P (TREE_CHAIN (gen_tmpl)))
13071 clone_function_decl (fndecl, /*update_method_vec_p=*/0);
13076 /* The FN is a TEMPLATE_DECL for a function. ARGS is an array with
13077 NARGS elements of the arguments that are being used when calling
13078 it. TARGS is a vector into which the deduced template arguments
13081 Return zero for success, 2 for an incomplete match that doesn't resolve
13082 all the types, and 1 for complete failure. An error message will be
13083 printed only for an incomplete match.
13085 If FN is a conversion operator, or we are trying to produce a specific
13086 specialization, RETURN_TYPE is the return type desired.
13088 The EXPLICIT_TARGS are explicit template arguments provided via a
13091 The parameter STRICT is one of:
13094 We are deducing arguments for a function call, as in
13095 [temp.deduct.call].
13098 We are deducing arguments for a conversion function, as in
13099 [temp.deduct.conv].
13102 We are deducing arguments when doing an explicit instantiation
13103 as in [temp.explicit], when determining an explicit specialization
13104 as in [temp.expl.spec], or when taking the address of a function
13105 template, as in [temp.deduct.funcaddr]. */
13108 fn_type_unification (tree fn,
13109 tree explicit_targs,
13112 unsigned int nargs,
13114 unification_kind_t strict,
13120 bool incomplete_argument_packs_p = false;
13122 gcc_assert (TREE_CODE (fn) == TEMPLATE_DECL);
13124 fntype = TREE_TYPE (fn);
13125 if (explicit_targs)
13129 The specified template arguments must match the template
13130 parameters in kind (i.e., type, nontype, template), and there
13131 must not be more arguments than there are parameters;
13132 otherwise type deduction fails.
13134 Nontype arguments must match the types of the corresponding
13135 nontype template parameters, or must be convertible to the
13136 types of the corresponding nontype parameters as specified in
13137 _temp.arg.nontype_, otherwise type deduction fails.
13139 All references in the function type of the function template
13140 to the corresponding template parameters are replaced by the
13141 specified template argument values. If a substitution in a
13142 template parameter or in the function type of the function
13143 template results in an invalid type, type deduction fails. */
13144 tree tparms = DECL_INNERMOST_TEMPLATE_PARMS (fn);
13145 int i, len = TREE_VEC_LENGTH (tparms);
13146 tree converted_args;
13147 bool incomplete = false;
13149 if (explicit_targs == error_mark_node)
13153 = (coerce_template_parms (tparms, explicit_targs, NULL_TREE, tf_none,
13154 /*require_all_args=*/false,
13155 /*use_default_args=*/false));
13156 if (converted_args == error_mark_node)
13159 /* Substitute the explicit args into the function type. This is
13160 necessary so that, for instance, explicitly declared function
13161 arguments can match null pointed constants. If we were given
13162 an incomplete set of explicit args, we must not do semantic
13163 processing during substitution as we could create partial
13165 for (i = 0; i < len; i++)
13167 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
13168 bool parameter_pack = false;
13170 /* Dig out the actual parm. */
13171 if (TREE_CODE (parm) == TYPE_DECL
13172 || TREE_CODE (parm) == TEMPLATE_DECL)
13174 parm = TREE_TYPE (parm);
13175 parameter_pack = TEMPLATE_TYPE_PARAMETER_PACK (parm);
13177 else if (TREE_CODE (parm) == PARM_DECL)
13179 parm = DECL_INITIAL (parm);
13180 parameter_pack = TEMPLATE_PARM_PARAMETER_PACK (parm);
13183 if (parameter_pack)
13187 template_parm_level_and_index (parm, &level, &idx);
13189 /* Mark the argument pack as "incomplete". We could
13190 still deduce more arguments during unification. */
13191 targ = TMPL_ARG (converted_args, level, idx);
13194 ARGUMENT_PACK_INCOMPLETE_P(targ) = 1;
13195 ARGUMENT_PACK_EXPLICIT_ARGS (targ)
13196 = ARGUMENT_PACK_ARGS (targ);
13199 /* We have some incomplete argument packs. */
13200 incomplete_argument_packs_p = true;
13204 if (incomplete_argument_packs_p)
13205 /* Any substitution is guaranteed to be incomplete if there
13206 are incomplete argument packs, because we can still deduce
13210 incomplete = NUM_TMPL_ARGS (explicit_targs) != NUM_TMPL_ARGS (targs);
13212 processing_template_decl += incomplete;
13213 fntype = tsubst (fntype, converted_args, tf_none, NULL_TREE);
13214 processing_template_decl -= incomplete;
13216 if (fntype == error_mark_node)
13219 /* Place the explicitly specified arguments in TARGS. */
13220 for (i = NUM_TMPL_ARGS (converted_args); i--;)
13221 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (converted_args, i);
13224 /* Never do unification on the 'this' parameter. */
13225 parms = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (fntype));
13231 parms = tree_cons (NULL_TREE, TREE_TYPE (fntype), parms);
13232 new_args = XALLOCAVEC (tree, nargs + 1);
13233 new_args[0] = return_type;
13234 memcpy (new_args + 1, args, nargs * sizeof (tree));
13239 /* We allow incomplete unification without an error message here
13240 because the standard doesn't seem to explicitly prohibit it. Our
13241 callers must be ready to deal with unification failures in any
13243 result = type_unification_real (DECL_INNERMOST_TEMPLATE_PARMS (fn),
13244 targs, parms, args, nargs, /*subr=*/0,
13247 if (result == 0 && incomplete_argument_packs_p)
13249 int i, len = NUM_TMPL_ARGS (targs);
13251 /* Clear the "incomplete" flags on all argument packs. */
13252 for (i = 0; i < len; i++)
13254 tree arg = TREE_VEC_ELT (targs, i);
13255 if (ARGUMENT_PACK_P (arg))
13257 ARGUMENT_PACK_INCOMPLETE_P (arg) = 0;
13258 ARGUMENT_PACK_EXPLICIT_ARGS (arg) = NULL_TREE;
13263 /* Now that we have bindings for all of the template arguments,
13264 ensure that the arguments deduced for the template template
13265 parameters have compatible template parameter lists. We cannot
13266 check this property before we have deduced all template
13267 arguments, because the template parameter types of a template
13268 template parameter might depend on prior template parameters
13269 deduced after the template template parameter. The following
13270 ill-formed example illustrates this issue:
13272 template<typename T, template<T> class C> void f(C<5>, T);
13274 template<int N> struct X {};
13277 f(X<5>(), 5l); // error: template argument deduction fails
13280 The template parameter list of 'C' depends on the template type
13281 parameter 'T', but 'C' is deduced to 'X' before 'T' is deduced to
13282 'long'. Thus, we can't check that 'C' cannot bind to 'X' at the
13283 time that we deduce 'C'. */
13285 && !template_template_parm_bindings_ok_p
13286 (DECL_INNERMOST_TEMPLATE_PARMS (fn), targs))
13290 /* All is well so far. Now, check:
13294 When all template arguments have been deduced, all uses of
13295 template parameters in nondeduced contexts are replaced with
13296 the corresponding deduced argument values. If the
13297 substitution results in an invalid type, as described above,
13298 type deduction fails. */
13300 tree substed = tsubst (TREE_TYPE (fn), targs, tf_none, NULL_TREE);
13301 if (substed == error_mark_node)
13304 /* If we're looking for an exact match, check that what we got
13305 is indeed an exact match. It might not be if some template
13306 parameters are used in non-deduced contexts. */
13307 if (strict == DEDUCE_EXACT)
13312 = skip_artificial_parms_for (fn, TYPE_ARG_TYPES (substed));
13314 sarg = tree_cons (NULL_TREE, TREE_TYPE (substed), sarg);
13315 for (i = 0; i < nargs && sarg; ++i, sarg = TREE_CHAIN (sarg))
13316 if (!same_type_p (args[i], TREE_VALUE (sarg)))
13324 /* Adjust types before performing type deduction, as described in
13325 [temp.deduct.call] and [temp.deduct.conv]. The rules in these two
13326 sections are symmetric. PARM is the type of a function parameter
13327 or the return type of the conversion function. ARG is the type of
13328 the argument passed to the call, or the type of the value
13329 initialized with the result of the conversion function.
13330 ARG_EXPR is the original argument expression, which may be null. */
13333 maybe_adjust_types_for_deduction (unification_kind_t strict,
13347 /* Swap PARM and ARG throughout the remainder of this
13348 function; the handling is precisely symmetric since PARM
13349 will initialize ARG rather than vice versa. */
13357 /* Core issue #873: Do the DR606 thing (see below) for these cases,
13358 too, but here handle it by stripping the reference from PARM
13359 rather than by adding it to ARG. */
13360 if (TREE_CODE (*parm) == REFERENCE_TYPE
13361 && TYPE_REF_IS_RVALUE (*parm)
13362 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
13363 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
13364 && TREE_CODE (*arg) == REFERENCE_TYPE
13365 && !TYPE_REF_IS_RVALUE (*arg))
13366 *parm = TREE_TYPE (*parm);
13367 /* Nothing else to do in this case. */
13371 gcc_unreachable ();
13374 if (TREE_CODE (*parm) != REFERENCE_TYPE)
13376 /* [temp.deduct.call]
13378 If P is not a reference type:
13380 --If A is an array type, the pointer type produced by the
13381 array-to-pointer standard conversion (_conv.array_) is
13382 used in place of A for type deduction; otherwise,
13384 --If A is a function type, the pointer type produced by
13385 the function-to-pointer standard conversion
13386 (_conv.func_) is used in place of A for type deduction;
13389 --If A is a cv-qualified type, the top level
13390 cv-qualifiers of A's type are ignored for type
13392 if (TREE_CODE (*arg) == ARRAY_TYPE)
13393 *arg = build_pointer_type (TREE_TYPE (*arg));
13394 else if (TREE_CODE (*arg) == FUNCTION_TYPE)
13395 *arg = build_pointer_type (*arg);
13397 *arg = TYPE_MAIN_VARIANT (*arg);
13400 /* From C++0x [14.8.2.1/3 temp.deduct.call] (after DR606), "If P is
13401 of the form T&&, where T is a template parameter, and the argument
13402 is an lvalue, T is deduced as A& */
13403 if (TREE_CODE (*parm) == REFERENCE_TYPE
13404 && TYPE_REF_IS_RVALUE (*parm)
13405 && TREE_CODE (TREE_TYPE (*parm)) == TEMPLATE_TYPE_PARM
13406 && cp_type_quals (TREE_TYPE (*parm)) == TYPE_UNQUALIFIED
13407 && arg_expr && real_lvalue_p (arg_expr))
13408 *arg = build_reference_type (*arg);
13410 /* [temp.deduct.call]
13412 If P is a cv-qualified type, the top level cv-qualifiers
13413 of P's type are ignored for type deduction. If P is a
13414 reference type, the type referred to by P is used for
13416 *parm = TYPE_MAIN_VARIANT (*parm);
13417 if (TREE_CODE (*parm) == REFERENCE_TYPE)
13419 *parm = TREE_TYPE (*parm);
13420 result |= UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
13423 /* DR 322. For conversion deduction, remove a reference type on parm
13424 too (which has been swapped into ARG). */
13425 if (strict == DEDUCE_CONV && TREE_CODE (*arg) == REFERENCE_TYPE)
13426 *arg = TREE_TYPE (*arg);
13431 /* Most parms like fn_type_unification.
13433 If SUBR is 1, we're being called recursively (to unify the
13434 arguments of a function or method parameter of a function
13438 type_unification_real (tree tparms,
13442 unsigned int xnargs,
13444 unification_kind_t strict,
13447 tree parm, arg, arg_expr;
13449 int ntparms = TREE_VEC_LENGTH (tparms);
13451 int saw_undeduced = 0;
13454 unsigned int nargs;
13457 gcc_assert (TREE_CODE (tparms) == TREE_VEC);
13458 gcc_assert (xparms == NULL_TREE || TREE_CODE (xparms) == TREE_LIST);
13459 gcc_assert (ntparms > 0);
13461 /* Reset the number of non-defaulted template arguments contained
13463 NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs) = NULL_TREE;
13468 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL | UNIFY_ALLOW_MORE_CV_QUAL
13469 | UNIFY_ALLOW_DERIVED);
13473 sub_strict = UNIFY_ALLOW_LESS_CV_QUAL;
13477 sub_strict = UNIFY_ALLOW_NONE;
13481 gcc_unreachable ();
13490 while (parms && parms != void_list_node
13493 if (TREE_CODE (TREE_VALUE (parms)) == TYPE_PACK_EXPANSION)
13496 parm = TREE_VALUE (parms);
13497 parms = TREE_CHAIN (parms);
13502 if (arg == error_mark_node)
13504 if (arg == unknown_type_node)
13505 /* We can't deduce anything from this, but we might get all the
13506 template args from other function args. */
13509 /* Conversions will be performed on a function argument that
13510 corresponds with a function parameter that contains only
13511 non-deducible template parameters and explicitly specified
13512 template parameters. */
13513 if (!uses_template_parms (parm))
13518 type = TREE_TYPE (arg);
13522 if (same_type_p (parm, type))
13524 if (strict != DEDUCE_EXACT
13525 && can_convert_arg (parm, type, TYPE_P (arg) ? NULL_TREE : arg,
13534 gcc_assert (TREE_TYPE (arg) != NULL_TREE);
13535 if (type_unknown_p (arg))
13537 /* [temp.deduct.type]
13539 A template-argument can be deduced from a pointer to
13540 function or pointer to member function argument if
13541 the set of overloaded functions does not contain
13542 function templates and at most one of a set of
13543 overloaded functions provides a unique match. */
13544 if (resolve_overloaded_unification
13545 (tparms, targs, parm, arg, strict, sub_strict))
13551 arg = unlowered_expr_type (arg);
13552 if (arg == error_mark_node)
13557 int arg_strict = sub_strict;
13560 arg_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg,
13563 if (arg == init_list_type_node && arg_expr)
13565 if (unify (tparms, targs, parm, arg, arg_strict))
13572 && parms != void_list_node
13573 && TREE_CODE (TREE_VALUE (parms)) == TYPE_PACK_EXPANSION)
13575 /* Unify the remaining arguments with the pack expansion type. */
13577 tree parmvec = make_tree_vec (1);
13579 /* Allocate a TREE_VEC and copy in all of the arguments */
13580 argvec = make_tree_vec (nargs - ia);
13581 for (i = 0; ia < nargs; ++ia, ++i)
13582 TREE_VEC_ELT (argvec, i) = args[ia];
13584 /* Copy the parameter into parmvec. */
13585 TREE_VEC_ELT (parmvec, 0) = TREE_VALUE (parms);
13586 if (unify_pack_expansion (tparms, targs, parmvec, argvec, strict,
13587 /*call_args_p=*/true, /*subr=*/subr))
13590 /* Advance to the end of the list of parameters. */
13591 parms = TREE_CHAIN (parms);
13594 /* Fail if we've reached the end of the parm list, and more args
13595 are present, and the parm list isn't variadic. */
13596 if (ia < nargs && parms == void_list_node)
13598 /* Fail if parms are left and they don't have default values. */
13599 if (parms && parms != void_list_node
13600 && TREE_PURPOSE (parms) == NULL_TREE)
13604 for (i = 0; i < ntparms; i++)
13605 if (!TREE_VEC_ELT (targs, i))
13609 if (TREE_VEC_ELT (tparms, i) == error_mark_node)
13612 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
13614 /* If this is an undeduced nontype parameter that depends on
13615 a type parameter, try another pass; its type may have been
13616 deduced from a later argument than the one from which
13617 this parameter can be deduced. */
13618 if (TREE_CODE (tparm) == PARM_DECL
13619 && uses_template_parms (TREE_TYPE (tparm))
13620 && !saw_undeduced++)
13623 /* Core issue #226 (C++0x) [temp.deduct]:
13625 If a template argument has not been deduced, its
13626 default template argument, if any, is used.
13628 When we are in C++98 mode, TREE_PURPOSE will either
13629 be NULL_TREE or ERROR_MARK_NODE, so we do not need
13630 to explicitly check cxx_dialect here. */
13631 if (TREE_PURPOSE (TREE_VEC_ELT (tparms, i)))
13633 tree parm = TREE_VALUE (TREE_VEC_ELT (tparms, i));
13634 tree arg = TREE_PURPOSE (TREE_VEC_ELT (tparms, i));
13635 arg = tsubst_template_arg (arg, targs, tf_none, NULL_TREE);
13636 arg = convert_template_argument (parm, arg, targs, tf_none,
13638 if (arg == error_mark_node)
13642 TREE_VEC_ELT (targs, i) = arg;
13643 /* The position of the first default template argument,
13644 is also the number of non-defaulted arguments in TARGS.
13646 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs))
13647 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, i);
13652 /* If the type parameter is a parameter pack, then it will
13653 be deduced to an empty parameter pack. */
13654 if (template_parameter_pack_p (tparm))
13658 if (TREE_CODE (tparm) == TEMPLATE_PARM_INDEX)
13660 arg = make_node (NONTYPE_ARGUMENT_PACK);
13661 TREE_TYPE (arg) = TREE_TYPE (TEMPLATE_PARM_DECL (tparm));
13662 TREE_CONSTANT (arg) = 1;
13665 arg = cxx_make_type (TYPE_ARGUMENT_PACK);
13667 SET_ARGUMENT_PACK_ARGS (arg, make_tree_vec (0));
13669 TREE_VEC_ELT (targs, i) = arg;
13675 #ifdef ENABLE_CHECKING
13676 if (!NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs))
13677 SET_NON_DEFAULT_TEMPLATE_ARGS_COUNT (targs, TREE_VEC_LENGTH (targs));
13683 /* Subroutine of type_unification_real. Args are like the variables
13684 at the call site. ARG is an overloaded function (or template-id);
13685 we try deducing template args from each of the overloads, and if
13686 only one succeeds, we go with that. Modifies TARGS and returns
13687 true on success. */
13690 resolve_overloaded_unification (tree tparms,
13694 unification_kind_t strict,
13697 tree tempargs = copy_node (targs);
13699 tree goodfn = NULL_TREE;
13702 if (TREE_CODE (arg) == ADDR_EXPR)
13704 arg = TREE_OPERAND (arg, 0);
13710 if (TREE_CODE (arg) == COMPONENT_REF)
13711 /* Handle `&x' where `x' is some static or non-static member
13713 arg = TREE_OPERAND (arg, 1);
13715 if (TREE_CODE (arg) == OFFSET_REF)
13716 arg = TREE_OPERAND (arg, 1);
13718 /* Strip baselink information. */
13719 if (BASELINK_P (arg))
13720 arg = BASELINK_FUNCTIONS (arg);
13722 if (TREE_CODE (arg) == TEMPLATE_ID_EXPR)
13724 /* If we got some explicit template args, we need to plug them into
13725 the affected templates before we try to unify, in case the
13726 explicit args will completely resolve the templates in question. */
13728 tree expl_subargs = TREE_OPERAND (arg, 1);
13729 arg = TREE_OPERAND (arg, 0);
13731 for (; arg; arg = OVL_NEXT (arg))
13733 tree fn = OVL_CURRENT (arg);
13734 tree subargs, elem;
13736 if (TREE_CODE (fn) != TEMPLATE_DECL)
13739 ++processing_template_decl;
13740 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
13741 expl_subargs, /*check_ret=*/false);
13744 elem = tsubst (TREE_TYPE (fn), subargs, tf_none, NULL_TREE);
13745 if (try_one_overload (tparms, targs, tempargs, parm,
13746 elem, strict, sub_strict, addr_p)
13747 && (!goodfn || !decls_match (goodfn, elem)))
13753 --processing_template_decl;
13756 else if (TREE_CODE (arg) != OVERLOAD
13757 && TREE_CODE (arg) != FUNCTION_DECL)
13758 /* If ARG is, for example, "(0, &f)" then its type will be unknown
13759 -- but the deduction does not succeed because the expression is
13760 not just the function on its own. */
13763 for (; arg; arg = OVL_NEXT (arg))
13764 if (try_one_overload (tparms, targs, tempargs, parm,
13765 TREE_TYPE (OVL_CURRENT (arg)),
13766 strict, sub_strict, addr_p)
13767 && (!goodfn || !decls_match (goodfn, OVL_CURRENT (arg))))
13769 goodfn = OVL_CURRENT (arg);
13773 /* [temp.deduct.type] A template-argument can be deduced from a pointer
13774 to function or pointer to member function argument if the set of
13775 overloaded functions does not contain function templates and at most
13776 one of a set of overloaded functions provides a unique match.
13778 So if we found multiple possibilities, we return success but don't
13779 deduce anything. */
13783 int i = TREE_VEC_LENGTH (targs);
13785 if (TREE_VEC_ELT (tempargs, i))
13786 TREE_VEC_ELT (targs, i) = TREE_VEC_ELT (tempargs, i);
13794 /* Core DR 115: In contexts where deduction is done and fails, or in
13795 contexts where deduction is not done, if a template argument list is
13796 specified and it, along with any default template arguments, identifies
13797 a single function template specialization, then the template-id is an
13798 lvalue for the function template specialization. */
13801 resolve_nondeduced_context (tree orig_expr)
13803 tree expr, offset, baselink;
13806 if (!type_unknown_p (orig_expr))
13811 offset = NULL_TREE;
13812 baselink = NULL_TREE;
13814 if (TREE_CODE (expr) == ADDR_EXPR)
13816 expr = TREE_OPERAND (expr, 0);
13819 if (TREE_CODE (expr) == OFFSET_REF)
13822 expr = TREE_OPERAND (expr, 1);
13824 if (TREE_CODE (expr) == BASELINK)
13827 expr = BASELINK_FUNCTIONS (expr);
13830 if (TREE_CODE (expr) == TEMPLATE_ID_EXPR)
13833 tree goodfn = NULL_TREE;
13835 /* If we got some explicit template args, we need to plug them into
13836 the affected templates before we try to unify, in case the
13837 explicit args will completely resolve the templates in question. */
13839 tree expl_subargs = TREE_OPERAND (expr, 1);
13840 tree arg = TREE_OPERAND (expr, 0);
13841 tree badfn = NULL_TREE;
13842 tree badargs = NULL_TREE;
13844 for (; arg; arg = OVL_NEXT (arg))
13846 tree fn = OVL_CURRENT (arg);
13847 tree subargs, elem;
13849 if (TREE_CODE (fn) != TEMPLATE_DECL)
13852 ++processing_template_decl;
13853 subargs = get_bindings (fn, DECL_TEMPLATE_RESULT (fn),
13854 expl_subargs, /*check_ret=*/false);
13855 if (subargs && !any_dependent_template_arguments_p (subargs))
13857 elem = instantiate_template (fn, subargs, tf_none);
13858 if (elem == error_mark_node)
13863 else if (elem && (!goodfn || !decls_match (goodfn, elem)))
13869 --processing_template_decl;
13875 expr = build_baselink (BASELINK_BINFO (baselink),
13876 BASELINK_ACCESS_BINFO (baselink),
13877 expr, BASELINK_OPTYPE (baselink));
13879 expr = build2 (OFFSET_REF, TREE_TYPE (expr),
13880 TREE_OPERAND (offset, 0), expr);
13882 expr = build_address (expr);
13885 else if (good == 0 && badargs)
13886 /* There were no good options and at least one bad one, so let the
13887 user know what the problem is. */
13888 instantiate_template (badfn, badargs, tf_warning_or_error);
13893 /* Subroutine of resolve_overloaded_unification; does deduction for a single
13894 overload. Fills TARGS with any deduced arguments, or error_mark_node if
13895 different overloads deduce different arguments for a given parm.
13896 ADDR_P is true if the expression for which deduction is being
13897 performed was of the form "& fn" rather than simply "fn".
13899 Returns 1 on success. */
13902 try_one_overload (tree tparms,
13907 unification_kind_t strict,
13915 /* [temp.deduct.type] A template-argument can be deduced from a pointer
13916 to function or pointer to member function argument if the set of
13917 overloaded functions does not contain function templates and at most
13918 one of a set of overloaded functions provides a unique match.
13920 So if this is a template, just return success. */
13922 if (uses_template_parms (arg))
13925 if (TREE_CODE (arg) == METHOD_TYPE)
13926 arg = build_ptrmemfunc_type (build_pointer_type (arg));
13928 arg = build_pointer_type (arg);
13930 sub_strict |= maybe_adjust_types_for_deduction (strict, &parm, &arg, NULL);
13932 /* We don't copy orig_targs for this because if we have already deduced
13933 some template args from previous args, unify would complain when we
13934 try to deduce a template parameter for the same argument, even though
13935 there isn't really a conflict. */
13936 nargs = TREE_VEC_LENGTH (targs);
13937 tempargs = make_tree_vec (nargs);
13939 if (unify (tparms, tempargs, parm, arg, sub_strict) != 0)
13942 /* First make sure we didn't deduce anything that conflicts with
13943 explicitly specified args. */
13944 for (i = nargs; i--; )
13946 tree elt = TREE_VEC_ELT (tempargs, i);
13947 tree oldelt = TREE_VEC_ELT (orig_targs, i);
13951 else if (uses_template_parms (elt))
13952 /* Since we're unifying against ourselves, we will fill in
13953 template args used in the function parm list with our own
13954 template parms. Discard them. */
13955 TREE_VEC_ELT (tempargs, i) = NULL_TREE;
13956 else if (oldelt && !template_args_equal (oldelt, elt))
13960 for (i = nargs; i--; )
13962 tree elt = TREE_VEC_ELT (tempargs, i);
13965 TREE_VEC_ELT (targs, i) = elt;
13971 /* PARM is a template class (perhaps with unbound template
13972 parameters). ARG is a fully instantiated type. If ARG can be
13973 bound to PARM, return ARG, otherwise return NULL_TREE. TPARMS and
13974 TARGS are as for unify. */
13977 try_class_unification (tree tparms, tree targs, tree parm, tree arg)
13979 tree copy_of_targs;
13981 if (!CLASSTYPE_TEMPLATE_INFO (arg)
13982 || (most_general_template (CLASSTYPE_TI_TEMPLATE (arg))
13983 != most_general_template (CLASSTYPE_TI_TEMPLATE (parm))))
13986 /* We need to make a new template argument vector for the call to
13987 unify. If we used TARGS, we'd clutter it up with the result of
13988 the attempted unification, even if this class didn't work out.
13989 We also don't want to commit ourselves to all the unifications
13990 we've already done, since unification is supposed to be done on
13991 an argument-by-argument basis. In other words, consider the
13992 following pathological case:
13994 template <int I, int J, int K>
13997 template <int I, int J>
13998 struct S<I, J, 2> : public S<I, I, I>, S<J, J, J> {};
14000 template <int I, int J, int K>
14001 void f(S<I, J, K>, S<I, I, I>);
14010 Now, by the time we consider the unification involving `s2', we
14011 already know that we must have `f<0, 0, 0>'. But, even though
14012 `S<0, 1, 2>' is derived from `S<0, 0, 0>', the code is invalid
14013 because there are two ways to unify base classes of S<0, 1, 2>
14014 with S<I, I, I>. If we kept the already deduced knowledge, we
14015 would reject the possibility I=1. */
14016 copy_of_targs = make_tree_vec (TREE_VEC_LENGTH (targs));
14018 /* If unification failed, we're done. */
14019 if (unify (tparms, copy_of_targs, CLASSTYPE_TI_ARGS (parm),
14020 CLASSTYPE_TI_ARGS (arg), UNIFY_ALLOW_NONE))
14026 /* Given a template type PARM and a class type ARG, find the unique
14027 base type in ARG that is an instance of PARM. We do not examine
14028 ARG itself; only its base-classes. If there is not exactly one
14029 appropriate base class, return NULL_TREE. PARM may be the type of
14030 a partial specialization, as well as a plain template type. Used
14034 get_template_base (tree tparms, tree targs, tree parm, tree arg)
14036 tree rval = NULL_TREE;
14039 gcc_assert (RECORD_OR_UNION_CODE_P (TREE_CODE (arg)));
14041 binfo = TYPE_BINFO (complete_type (arg));
14043 /* The type could not be completed. */
14046 /* Walk in inheritance graph order. The search order is not
14047 important, and this avoids multiple walks of virtual bases. */
14048 for (binfo = TREE_CHAIN (binfo); binfo; binfo = TREE_CHAIN (binfo))
14050 tree r = try_class_unification (tparms, targs, parm, BINFO_TYPE (binfo));
14054 /* If there is more than one satisfactory baseclass, then:
14058 If they yield more than one possible deduced A, the type
14062 if (rval && !same_type_p (r, rval))
14072 /* Returns the level of DECL, which declares a template parameter. */
14075 template_decl_level (tree decl)
14077 switch (TREE_CODE (decl))
14080 case TEMPLATE_DECL:
14081 return TEMPLATE_TYPE_LEVEL (TREE_TYPE (decl));
14084 return TEMPLATE_PARM_LEVEL (DECL_INITIAL (decl));
14087 gcc_unreachable ();
14092 /* Decide whether ARG can be unified with PARM, considering only the
14093 cv-qualifiers of each type, given STRICT as documented for unify.
14094 Returns nonzero iff the unification is OK on that basis. */
14097 check_cv_quals_for_unify (int strict, tree arg, tree parm)
14099 int arg_quals = cp_type_quals (arg);
14100 int parm_quals = cp_type_quals (parm);
14102 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
14103 && !(strict & UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
14105 /* Although a CVR qualifier is ignored when being applied to a
14106 substituted template parameter ([8.3.2]/1 for example), that
14107 does not apply during deduction [14.8.2.4]/1, (even though
14108 that is not explicitly mentioned, [14.8.2.4]/9 indicates
14109 this). Except when we're allowing additional CV qualifiers
14110 at the outer level [14.8.2.1]/3,1st bullet. */
14111 if ((TREE_CODE (arg) == REFERENCE_TYPE
14112 || TREE_CODE (arg) == FUNCTION_TYPE
14113 || TREE_CODE (arg) == METHOD_TYPE)
14114 && (parm_quals & (TYPE_QUAL_CONST | TYPE_QUAL_VOLATILE)))
14117 if ((!POINTER_TYPE_P (arg) && TREE_CODE (arg) != TEMPLATE_TYPE_PARM)
14118 && (parm_quals & TYPE_QUAL_RESTRICT))
14122 if (!(strict & (UNIFY_ALLOW_MORE_CV_QUAL | UNIFY_ALLOW_OUTER_MORE_CV_QUAL))
14123 && (arg_quals & parm_quals) != parm_quals)
14126 if (!(strict & (UNIFY_ALLOW_LESS_CV_QUAL | UNIFY_ALLOW_OUTER_LESS_CV_QUAL))
14127 && (parm_quals & arg_quals) != arg_quals)
14133 /* Determines the LEVEL and INDEX for the template parameter PARM. */
14135 template_parm_level_and_index (tree parm, int* level, int* index)
14137 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
14138 || TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
14139 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
14141 *index = TEMPLATE_TYPE_IDX (parm);
14142 *level = TEMPLATE_TYPE_LEVEL (parm);
14146 *index = TEMPLATE_PARM_IDX (parm);
14147 *level = TEMPLATE_PARM_LEVEL (parm);
14151 /* Unifies the remaining arguments in PACKED_ARGS with the pack
14152 expansion at the end of PACKED_PARMS. Returns 0 if the type
14153 deduction succeeds, 1 otherwise. STRICT is the same as in
14154 unify. CALL_ARGS_P is true iff PACKED_ARGS is actually a function
14155 call argument list. We'll need to adjust the arguments to make them
14156 types. SUBR tells us if this is from a recursive call to
14157 type_unification_real. */
14159 unify_pack_expansion (tree tparms, tree targs, tree packed_parms,
14160 tree packed_args, int strict, bool call_args_p,
14164 = TREE_VEC_ELT (packed_parms, TREE_VEC_LENGTH (packed_parms) - 1);
14165 tree pattern = PACK_EXPANSION_PATTERN (parm);
14166 tree pack, packs = NULL_TREE;
14167 int i, start = TREE_VEC_LENGTH (packed_parms) - 1;
14168 int len = TREE_VEC_LENGTH (packed_args);
14170 /* Determine the parameter packs we will be deducing from the
14171 pattern, and record their current deductions. */
14172 for (pack = PACK_EXPANSION_PARAMETER_PACKS (parm);
14173 pack; pack = TREE_CHAIN (pack))
14175 tree parm_pack = TREE_VALUE (pack);
14178 /* Determine the index and level of this parameter pack. */
14179 template_parm_level_and_index (parm_pack, &level, &idx);
14181 /* Keep track of the parameter packs and their corresponding
14183 packs = tree_cons (parm_pack, TMPL_ARG (targs, level, idx), packs);
14184 TREE_TYPE (packs) = make_tree_vec (len - start);
14187 /* Loop through all of the arguments that have not yet been
14188 unified and unify each with the pattern. */
14189 for (i = start; i < len; i++)
14191 tree parm = pattern;
14193 /* For each parameter pack, clear out the deduced value so that
14194 we can deduce it again. */
14195 for (pack = packs; pack; pack = TREE_CHAIN (pack))
14198 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
14200 TMPL_ARG (targs, level, idx) = NULL_TREE;
14203 /* Unify the pattern with the current argument. */
14205 tree arg = TREE_VEC_ELT (packed_args, i);
14206 tree arg_expr = NULL_TREE;
14207 int arg_strict = strict;
14208 bool skip_arg_p = false;
14214 /* This mirrors what we do in type_unification_real. */
14218 sub_strict = (UNIFY_ALLOW_OUTER_LEVEL
14219 | UNIFY_ALLOW_MORE_CV_QUAL
14220 | UNIFY_ALLOW_DERIVED);
14224 sub_strict = UNIFY_ALLOW_LESS_CV_QUAL;
14228 sub_strict = UNIFY_ALLOW_NONE;
14232 gcc_unreachable ();
14237 gcc_assert (TREE_TYPE (arg) != NULL_TREE);
14238 if (type_unknown_p (arg))
14240 /* [temp.deduct.type] A template-argument can be
14241 deduced from a pointer to function or pointer
14242 to member function argument if the set of
14243 overloaded functions does not contain function
14244 templates and at most one of a set of
14245 overloaded functions provides a unique
14248 if (resolve_overloaded_unification
14249 (tparms, targs, parm, arg,
14250 (unification_kind_t) strict,
14260 arg = unlowered_expr_type (arg);
14261 if (arg == error_mark_node)
14266 arg_strict = sub_strict;
14270 maybe_adjust_types_for_deduction ((unification_kind_t) strict,
14271 &parm, &arg, arg_expr);
14276 /* For deduction from an init-list we need the actual list. */
14277 if (arg_expr && BRACE_ENCLOSED_INITIALIZER_P (arg_expr))
14279 if (unify (tparms, targs, parm, arg, arg_strict))
14284 /* For each parameter pack, collect the deduced value. */
14285 for (pack = packs; pack; pack = TREE_CHAIN (pack))
14288 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
14290 TREE_VEC_ELT (TREE_TYPE (pack), i - start) =
14291 TMPL_ARG (targs, level, idx);
14295 /* Verify that the results of unification with the parameter packs
14296 produce results consistent with what we've seen before, and make
14297 the deduced argument packs available. */
14298 for (pack = packs; pack; pack = TREE_CHAIN (pack))
14300 tree old_pack = TREE_VALUE (pack);
14301 tree new_args = TREE_TYPE (pack);
14302 int i, len = TREE_VEC_LENGTH (new_args);
14304 bool nondeduced_p = false;
14306 /* By default keep the original deduced argument pack.
14307 If necessary, more specific code is going to update the
14308 resulting deduced argument later down in this function. */
14309 template_parm_level_and_index (TREE_PURPOSE (pack), &level, &idx);
14310 TMPL_ARG (targs, level, idx) = old_pack;
14312 /* If NEW_ARGS contains any NULL_TREE entries, we didn't
14313 actually deduce anything. */
14314 for (i = 0; i < len && !nondeduced_p; ++i)
14315 if (TREE_VEC_ELT (new_args, i) == NULL_TREE)
14316 nondeduced_p = true;
14320 if (old_pack && ARGUMENT_PACK_INCOMPLETE_P (old_pack))
14322 /* Prepend the explicit arguments onto NEW_ARGS. */
14323 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
14324 tree old_args = new_args;
14325 int i, explicit_len = TREE_VEC_LENGTH (explicit_args);
14326 int len = explicit_len + TREE_VEC_LENGTH (old_args);
14328 /* Copy the explicit arguments. */
14329 new_args = make_tree_vec (len);
14330 for (i = 0; i < explicit_len; i++)
14331 TREE_VEC_ELT (new_args, i) = TREE_VEC_ELT (explicit_args, i);
14333 /* Copy the deduced arguments. */
14334 for (; i < len; i++)
14335 TREE_VEC_ELT (new_args, i) =
14336 TREE_VEC_ELT (old_args, i - explicit_len);
14342 /* Build the deduced *_ARGUMENT_PACK. */
14343 if (TREE_CODE (TREE_PURPOSE (pack)) == TEMPLATE_PARM_INDEX)
14345 result = make_node (NONTYPE_ARGUMENT_PACK);
14346 TREE_TYPE (result) =
14347 TREE_TYPE (TEMPLATE_PARM_DECL (TREE_PURPOSE (pack)));
14348 TREE_CONSTANT (result) = 1;
14351 result = cxx_make_type (TYPE_ARGUMENT_PACK);
14353 SET_ARGUMENT_PACK_ARGS (result, new_args);
14355 /* Note the deduced argument packs for this parameter
14357 TMPL_ARG (targs, level, idx) = result;
14359 else if (ARGUMENT_PACK_INCOMPLETE_P (old_pack)
14360 && (ARGUMENT_PACK_ARGS (old_pack)
14361 == ARGUMENT_PACK_EXPLICIT_ARGS (old_pack)))
14363 /* We only had the explicitly-provided arguments before, but
14364 now we have a complete set of arguments. */
14365 tree explicit_args = ARGUMENT_PACK_EXPLICIT_ARGS (old_pack);
14367 SET_ARGUMENT_PACK_ARGS (old_pack, new_args);
14368 ARGUMENT_PACK_INCOMPLETE_P (old_pack) = 1;
14369 ARGUMENT_PACK_EXPLICIT_ARGS (old_pack) = explicit_args;
14371 else if (!comp_template_args (ARGUMENT_PACK_ARGS (old_pack),
14373 /* Inconsistent unification of this parameter pack. */
14380 /* Deduce the value of template parameters. TPARMS is the (innermost)
14381 set of template parameters to a template. TARGS is the bindings
14382 for those template parameters, as determined thus far; TARGS may
14383 include template arguments for outer levels of template parameters
14384 as well. PARM is a parameter to a template function, or a
14385 subcomponent of that parameter; ARG is the corresponding argument.
14386 This function attempts to match PARM with ARG in a manner
14387 consistent with the existing assignments in TARGS. If more values
14388 are deduced, then TARGS is updated.
14390 Returns 0 if the type deduction succeeds, 1 otherwise. The
14391 parameter STRICT is a bitwise or of the following flags:
14394 Require an exact match between PARM and ARG.
14395 UNIFY_ALLOW_MORE_CV_QUAL:
14396 Allow the deduced ARG to be more cv-qualified (by qualification
14397 conversion) than ARG.
14398 UNIFY_ALLOW_LESS_CV_QUAL:
14399 Allow the deduced ARG to be less cv-qualified than ARG.
14400 UNIFY_ALLOW_DERIVED:
14401 Allow the deduced ARG to be a template base class of ARG,
14402 or a pointer to a template base class of the type pointed to by
14404 UNIFY_ALLOW_INTEGER:
14405 Allow any integral type to be deduced. See the TEMPLATE_PARM_INDEX
14406 case for more information.
14407 UNIFY_ALLOW_OUTER_LEVEL:
14408 This is the outermost level of a deduction. Used to determine validity
14409 of qualification conversions. A valid qualification conversion must
14410 have const qualified pointers leading up to the inner type which
14411 requires additional CV quals, except at the outer level, where const
14412 is not required [conv.qual]. It would be normal to set this flag in
14413 addition to setting UNIFY_ALLOW_MORE_CV_QUAL.
14414 UNIFY_ALLOW_OUTER_MORE_CV_QUAL:
14415 This is the outermost level of a deduction, and PARM can be more CV
14416 qualified at this point.
14417 UNIFY_ALLOW_OUTER_LESS_CV_QUAL:
14418 This is the outermost level of a deduction, and PARM can be less CV
14419 qualified at this point. */
14422 unify (tree tparms, tree targs, tree parm, tree arg, int strict)
14427 int strict_in = strict;
14429 /* I don't think this will do the right thing with respect to types.
14430 But the only case I've seen it in so far has been array bounds, where
14431 signedness is the only information lost, and I think that will be
14433 while (TREE_CODE (parm) == NOP_EXPR)
14434 parm = TREE_OPERAND (parm, 0);
14436 if (arg == error_mark_node)
14438 if (arg == unknown_type_node
14439 || arg == init_list_type_node)
14440 /* We can't deduce anything from this, but we might get all the
14441 template args from other function args. */
14444 /* If PARM uses template parameters, then we can't bail out here,
14445 even if ARG == PARM, since we won't record unifications for the
14446 template parameters. We might need them if we're trying to
14447 figure out which of two things is more specialized. */
14448 if (arg == parm && !uses_template_parms (parm))
14451 /* Handle init lists early, so the rest of the function can assume
14452 we're dealing with a type. */
14453 if (BRACE_ENCLOSED_INITIALIZER_P (arg))
14457 tree orig_parm = parm;
14459 /* Replace T with std::initializer_list<T> for deduction. */
14460 if (TREE_CODE (parm) == TEMPLATE_TYPE_PARM
14461 && flag_deduce_init_list)
14462 parm = listify (parm);
14464 if (!is_std_init_list (parm))
14465 /* We can only deduce from an initializer list argument if the
14466 parameter is std::initializer_list; otherwise this is a
14467 non-deduced context. */
14470 elttype = TREE_VEC_ELT (CLASSTYPE_TI_ARGS (parm), 0);
14472 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (arg), i, elt)
14474 int elt_strict = strict;
14476 if (elt == error_mark_node)
14479 if (!BRACE_ENCLOSED_INITIALIZER_P (elt))
14481 tree type = TREE_TYPE (elt);
14482 /* It should only be possible to get here for a call. */
14483 gcc_assert (elt_strict & UNIFY_ALLOW_OUTER_LEVEL);
14484 elt_strict |= maybe_adjust_types_for_deduction
14485 (DEDUCE_CALL, &elttype, &type, elt);
14489 if (unify (tparms, targs, elttype, elt, elt_strict))
14493 /* If the std::initializer_list<T> deduction worked, replace the
14494 deduced A with std::initializer_list<A>. */
14495 if (orig_parm != parm)
14497 idx = TEMPLATE_TYPE_IDX (orig_parm);
14498 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
14499 targ = listify (targ);
14500 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = targ;
14505 /* Immediately reject some pairs that won't unify because of
14506 cv-qualification mismatches. */
14507 if (TREE_CODE (arg) == TREE_CODE (parm)
14509 /* It is the elements of the array which hold the cv quals of an array
14510 type, and the elements might be template type parms. We'll check
14511 when we recurse. */
14512 && TREE_CODE (arg) != ARRAY_TYPE
14513 /* We check the cv-qualifiers when unifying with template type
14514 parameters below. We want to allow ARG `const T' to unify with
14515 PARM `T' for example, when computing which of two templates
14516 is more specialized, for example. */
14517 && TREE_CODE (arg) != TEMPLATE_TYPE_PARM
14518 && !check_cv_quals_for_unify (strict_in, arg, parm))
14521 if (!(strict & UNIFY_ALLOW_OUTER_LEVEL)
14522 && TYPE_P (parm) && !CP_TYPE_CONST_P (parm))
14523 strict &= ~UNIFY_ALLOW_MORE_CV_QUAL;
14524 strict &= ~UNIFY_ALLOW_OUTER_LEVEL;
14525 strict &= ~UNIFY_ALLOW_DERIVED;
14526 strict &= ~UNIFY_ALLOW_OUTER_MORE_CV_QUAL;
14527 strict &= ~UNIFY_ALLOW_OUTER_LESS_CV_QUAL;
14529 switch (TREE_CODE (parm))
14531 case TYPENAME_TYPE:
14533 case UNBOUND_CLASS_TEMPLATE:
14534 /* In a type which contains a nested-name-specifier, template
14535 argument values cannot be deduced for template parameters used
14536 within the nested-name-specifier. */
14539 case TEMPLATE_TYPE_PARM:
14540 case TEMPLATE_TEMPLATE_PARM:
14541 case BOUND_TEMPLATE_TEMPLATE_PARM:
14542 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
14543 if (tparm == error_mark_node)
14546 if (TEMPLATE_TYPE_LEVEL (parm)
14547 != template_decl_level (tparm))
14548 /* The PARM is not one we're trying to unify. Just check
14549 to see if it matches ARG. */
14550 return (TREE_CODE (arg) == TREE_CODE (parm)
14551 && same_type_p (parm, arg)) ? 0 : 1;
14552 idx = TEMPLATE_TYPE_IDX (parm);
14553 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
14554 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, idx));
14556 /* Check for mixed types and values. */
14557 if ((TREE_CODE (parm) == TEMPLATE_TYPE_PARM
14558 && TREE_CODE (tparm) != TYPE_DECL)
14559 || (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
14560 && TREE_CODE (tparm) != TEMPLATE_DECL))
14563 if (TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
14565 /* ARG must be constructed from a template class or a template
14566 template parameter. */
14567 if (TREE_CODE (arg) != BOUND_TEMPLATE_TEMPLATE_PARM
14568 && !CLASSTYPE_SPECIALIZATION_OF_PRIMARY_TEMPLATE_P (arg))
14572 tree parmvec = TYPE_TI_ARGS (parm);
14573 tree argvec = INNERMOST_TEMPLATE_ARGS (TYPE_TI_ARGS (arg));
14575 = DECL_INNERMOST_TEMPLATE_PARMS
14576 (TEMPLATE_TEMPLATE_PARM_TEMPLATE_DECL (parm));
14578 int parm_variadic_p = 0;
14580 /* The resolution to DR150 makes clear that default
14581 arguments for an N-argument may not be used to bind T
14582 to a template template parameter with fewer than N
14583 parameters. It is not safe to permit the binding of
14584 default arguments as an extension, as that may change
14585 the meaning of a conforming program. Consider:
14587 struct Dense { static const unsigned int dim = 1; };
14589 template <template <typename> class View,
14591 void operator+(float, View<Block> const&);
14593 template <typename Block,
14594 unsigned int Dim = Block::dim>
14595 struct Lvalue_proxy { operator float() const; };
14599 Lvalue_proxy<Dense> p;
14604 Here, if Lvalue_proxy is permitted to bind to View, then
14605 the global operator+ will be used; if they are not, the
14606 Lvalue_proxy will be converted to float. */
14607 if (coerce_template_parms (parm_parms,
14609 TYPE_TI_TEMPLATE (parm),
14611 /*require_all_args=*/true,
14612 /*use_default_args=*/false)
14613 == error_mark_node)
14616 /* Deduce arguments T, i from TT<T> or TT<i>.
14617 We check each element of PARMVEC and ARGVEC individually
14618 rather than the whole TREE_VEC since they can have
14619 different number of elements. */
14621 parmvec = expand_template_argument_pack (parmvec);
14622 argvec = expand_template_argument_pack (argvec);
14624 len = TREE_VEC_LENGTH (parmvec);
14626 /* Check if the parameters end in a pack, making them
14629 && PACK_EXPANSION_P (TREE_VEC_ELT (parmvec, len - 1)))
14630 parm_variadic_p = 1;
14632 if (TREE_VEC_LENGTH (argvec) < len - parm_variadic_p)
14635 for (i = 0; i < len - parm_variadic_p; ++i)
14637 if (unify (tparms, targs,
14638 TREE_VEC_ELT (parmvec, i),
14639 TREE_VEC_ELT (argvec, i),
14644 if (parm_variadic_p
14645 && unify_pack_expansion (tparms, targs,
14648 /*call_args_p=*/false,
14652 arg = TYPE_TI_TEMPLATE (arg);
14654 /* Fall through to deduce template name. */
14657 if (TREE_CODE (parm) == TEMPLATE_TEMPLATE_PARM
14658 || TREE_CODE (parm) == BOUND_TEMPLATE_TEMPLATE_PARM)
14660 /* Deduce template name TT from TT, TT<>, TT<T> and TT<i>. */
14662 /* Simple cases: Value already set, does match or doesn't. */
14663 if (targ != NULL_TREE && template_args_equal (targ, arg))
14670 /* If PARM is `const T' and ARG is only `int', we don't have
14671 a match unless we are allowing additional qualification.
14672 If ARG is `const int' and PARM is just `T' that's OK;
14673 that binds `const int' to `T'. */
14674 if (!check_cv_quals_for_unify (strict_in | UNIFY_ALLOW_LESS_CV_QUAL,
14678 /* Consider the case where ARG is `const volatile int' and
14679 PARM is `const T'. Then, T should be `volatile int'. */
14680 arg = cp_build_qualified_type_real
14681 (arg, cp_type_quals (arg) & ~cp_type_quals (parm), tf_none);
14682 if (arg == error_mark_node)
14685 /* Simple cases: Value already set, does match or doesn't. */
14686 if (targ != NULL_TREE && same_type_p (targ, arg))
14691 /* Make sure that ARG is not a variable-sized array. (Note
14692 that were talking about variable-sized arrays (like
14693 `int[n]'), rather than arrays of unknown size (like
14694 `int[]').) We'll get very confused by such a type since
14695 the bound of the array will not be computable in an
14696 instantiation. Besides, such types are not allowed in
14697 ISO C++, so we can do as we please here. */
14698 if (variably_modified_type_p (arg, NULL_TREE))
14701 /* Strip typedefs as in convert_template_argument. */
14702 arg = strip_typedefs (arg);
14705 /* If ARG is a parameter pack or an expansion, we cannot unify
14706 against it unless PARM is also a parameter pack. */
14707 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
14708 && !template_parameter_pack_p (parm))
14711 /* If the argument deduction results is a METHOD_TYPE,
14712 then there is a problem.
14713 METHOD_TYPE doesn't map to any real C++ type the result of
14714 the deduction can not be of that type. */
14715 if (TREE_CODE (arg) == METHOD_TYPE)
14718 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
14721 case TEMPLATE_PARM_INDEX:
14722 tparm = TREE_VALUE (TREE_VEC_ELT (tparms, 0));
14723 if (tparm == error_mark_node)
14726 if (TEMPLATE_PARM_LEVEL (parm)
14727 != template_decl_level (tparm))
14728 /* The PARM is not one we're trying to unify. Just check
14729 to see if it matches ARG. */
14730 return !(TREE_CODE (arg) == TREE_CODE (parm)
14731 && cp_tree_equal (parm, arg));
14733 idx = TEMPLATE_PARM_IDX (parm);
14734 targ = TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx);
14737 return !cp_tree_equal (targ, arg);
14739 /* [temp.deduct.type] If, in the declaration of a function template
14740 with a non-type template-parameter, the non-type
14741 template-parameter is used in an expression in the function
14742 parameter-list and, if the corresponding template-argument is
14743 deduced, the template-argument type shall match the type of the
14744 template-parameter exactly, except that a template-argument
14745 deduced from an array bound may be of any integral type.
14746 The non-type parameter might use already deduced type parameters. */
14747 tparm = tsubst (TREE_TYPE (parm), targs, 0, NULL_TREE);
14748 if (!TREE_TYPE (arg))
14749 /* Template-parameter dependent expression. Just accept it for now.
14750 It will later be processed in convert_template_argument. */
14752 else if (same_type_p (TREE_TYPE (arg), tparm))
14754 else if ((strict & UNIFY_ALLOW_INTEGER)
14755 && (TREE_CODE (tparm) == INTEGER_TYPE
14756 || TREE_CODE (tparm) == BOOLEAN_TYPE))
14757 /* Convert the ARG to the type of PARM; the deduced non-type
14758 template argument must exactly match the types of the
14759 corresponding parameter. */
14760 arg = fold (build_nop (tparm, arg));
14761 else if (uses_template_parms (tparm))
14762 /* We haven't deduced the type of this parameter yet. Try again
14768 /* If ARG is a parameter pack or an expansion, we cannot unify
14769 against it unless PARM is also a parameter pack. */
14770 if ((template_parameter_pack_p (arg) || PACK_EXPANSION_P (arg))
14771 && !TEMPLATE_PARM_PARAMETER_PACK (parm))
14774 TREE_VEC_ELT (INNERMOST_TEMPLATE_ARGS (targs), idx) = arg;
14779 /* A pointer-to-member constant can be unified only with
14780 another constant. */
14781 if (TREE_CODE (arg) != PTRMEM_CST)
14784 /* Just unify the class member. It would be useless (and possibly
14785 wrong, depending on the strict flags) to unify also
14786 PTRMEM_CST_CLASS, because we want to be sure that both parm and
14787 arg refer to the same variable, even if through different
14788 classes. For instance:
14790 struct A { int x; };
14793 Unification of &A::x and &B::x must succeed. */
14794 return unify (tparms, targs, PTRMEM_CST_MEMBER (parm),
14795 PTRMEM_CST_MEMBER (arg), strict);
14800 if (TREE_CODE (arg) != POINTER_TYPE)
14803 /* [temp.deduct.call]
14805 A can be another pointer or pointer to member type that can
14806 be converted to the deduced A via a qualification
14807 conversion (_conv.qual_).
14809 We pass down STRICT here rather than UNIFY_ALLOW_NONE.
14810 This will allow for additional cv-qualification of the
14811 pointed-to types if appropriate. */
14813 if (TREE_CODE (TREE_TYPE (arg)) == RECORD_TYPE)
14814 /* The derived-to-base conversion only persists through one
14815 level of pointers. */
14816 strict |= (strict_in & UNIFY_ALLOW_DERIVED);
14818 return unify (tparms, targs, TREE_TYPE (parm),
14819 TREE_TYPE (arg), strict);
14822 case REFERENCE_TYPE:
14823 if (TREE_CODE (arg) != REFERENCE_TYPE)
14825 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
14826 strict & UNIFY_ALLOW_MORE_CV_QUAL);
14829 if (TREE_CODE (arg) != ARRAY_TYPE)
14831 if ((TYPE_DOMAIN (parm) == NULL_TREE)
14832 != (TYPE_DOMAIN (arg) == NULL_TREE))
14834 if (TYPE_DOMAIN (parm) != NULL_TREE)
14841 /* Our representation of array types uses "N - 1" as the
14842 TYPE_MAX_VALUE for an array with "N" elements, if "N" is
14843 not an integer constant. We cannot unify arbitrarily
14844 complex expressions, so we eliminate the MINUS_EXPRs
14846 parm_max = TYPE_MAX_VALUE (TYPE_DOMAIN (parm));
14847 parm_cst = TREE_CODE (parm_max) == INTEGER_CST;
14850 gcc_assert (TREE_CODE (parm_max) == MINUS_EXPR);
14851 parm_max = TREE_OPERAND (parm_max, 0);
14853 arg_max = TYPE_MAX_VALUE (TYPE_DOMAIN (arg));
14854 arg_cst = TREE_CODE (arg_max) == INTEGER_CST;
14857 /* The ARG_MAX may not be a simple MINUS_EXPR, if we are
14858 trying to unify the type of a variable with the type
14859 of a template parameter. For example:
14861 template <unsigned int N>
14862 void f (char (&) [N]);
14869 Here, the type of the ARG will be "int [g(i)]", and
14870 may be a SAVE_EXPR, etc. */
14871 if (TREE_CODE (arg_max) != MINUS_EXPR)
14873 arg_max = TREE_OPERAND (arg_max, 0);
14876 /* If only one of the bounds used a MINUS_EXPR, compensate
14877 by adding one to the other bound. */
14878 if (parm_cst && !arg_cst)
14879 parm_max = fold_build2_loc (input_location, PLUS_EXPR,
14883 else if (arg_cst && !parm_cst)
14884 arg_max = fold_build2_loc (input_location, PLUS_EXPR,
14889 if (unify (tparms, targs, parm_max, arg_max, UNIFY_ALLOW_INTEGER))
14892 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
14893 strict & UNIFY_ALLOW_MORE_CV_QUAL);
14900 case ENUMERAL_TYPE:
14902 if (TREE_CODE (arg) != TREE_CODE (parm))
14905 /* We have already checked cv-qualification at the top of the
14907 if (!same_type_ignoring_top_level_qualifiers_p (arg, parm))
14910 /* As far as unification is concerned, this wins. Later checks
14911 will invalidate it if necessary. */
14914 /* Types INTEGER_CST and MINUS_EXPR can come from array bounds. */
14915 /* Type INTEGER_CST can come from ordinary constant template args. */
14917 while (TREE_CODE (arg) == NOP_EXPR)
14918 arg = TREE_OPERAND (arg, 0);
14920 if (TREE_CODE (arg) != INTEGER_CST)
14922 return !tree_int_cst_equal (parm, arg);
14927 if (TREE_CODE (arg) != TREE_VEC)
14929 if (TREE_VEC_LENGTH (parm) != TREE_VEC_LENGTH (arg))
14931 for (i = 0; i < TREE_VEC_LENGTH (parm); ++i)
14932 if (unify (tparms, targs,
14933 TREE_VEC_ELT (parm, i), TREE_VEC_ELT (arg, i),
14941 if (TREE_CODE (arg) != TREE_CODE (parm))
14944 if (TYPE_PTRMEMFUNC_P (parm))
14946 if (!TYPE_PTRMEMFUNC_P (arg))
14949 return unify (tparms, targs,
14950 TYPE_PTRMEMFUNC_FN_TYPE (parm),
14951 TYPE_PTRMEMFUNC_FN_TYPE (arg),
14955 if (CLASSTYPE_TEMPLATE_INFO (parm))
14957 tree t = NULL_TREE;
14959 if (strict_in & UNIFY_ALLOW_DERIVED)
14961 /* First, we try to unify the PARM and ARG directly. */
14962 t = try_class_unification (tparms, targs,
14967 /* Fallback to the special case allowed in
14968 [temp.deduct.call]:
14970 If P is a class, and P has the form
14971 template-id, then A can be a derived class of
14972 the deduced A. Likewise, if P is a pointer to
14973 a class of the form template-id, A can be a
14974 pointer to a derived class pointed to by the
14976 t = get_template_base (tparms, targs, parm, arg);
14982 else if (CLASSTYPE_TEMPLATE_INFO (arg)
14983 && (CLASSTYPE_TI_TEMPLATE (parm)
14984 == CLASSTYPE_TI_TEMPLATE (arg)))
14985 /* Perhaps PARM is something like S<U> and ARG is S<int>.
14986 Then, we should unify `int' and `U'. */
14989 /* There's no chance of unification succeeding. */
14992 return unify (tparms, targs, CLASSTYPE_TI_ARGS (parm),
14993 CLASSTYPE_TI_ARGS (t), UNIFY_ALLOW_NONE);
14995 else if (!same_type_ignoring_top_level_qualifiers_p (parm, arg))
15000 case FUNCTION_TYPE:
15002 unsigned int nargs;
15007 if (TREE_CODE (arg) != TREE_CODE (parm))
15010 /* CV qualifications for methods can never be deduced, they must
15011 match exactly. We need to check them explicitly here,
15012 because type_unification_real treats them as any other
15013 cv-qualified parameter. */
15014 if (TREE_CODE (parm) == METHOD_TYPE
15015 && (!check_cv_quals_for_unify
15017 TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (arg))),
15018 TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (parm))))))
15021 if (unify (tparms, targs, TREE_TYPE (parm),
15022 TREE_TYPE (arg), UNIFY_ALLOW_NONE))
15025 nargs = list_length (TYPE_ARG_TYPES (arg));
15026 args = XALLOCAVEC (tree, nargs);
15027 for (a = TYPE_ARG_TYPES (arg), i = 0;
15028 a != NULL_TREE && a != void_list_node;
15029 a = TREE_CHAIN (a), ++i)
15030 args[i] = TREE_VALUE (a);
15033 return type_unification_real (tparms, targs, TYPE_ARG_TYPES (parm),
15034 args, nargs, 1, DEDUCE_EXACT,
15039 /* Unify a pointer to member with a pointer to member function, which
15040 deduces the type of the member as a function type. */
15041 if (TYPE_PTRMEMFUNC_P (arg))
15045 cp_cv_quals cv_quals;
15047 /* Check top-level cv qualifiers */
15048 if (!check_cv_quals_for_unify (UNIFY_ALLOW_NONE, arg, parm))
15051 if (unify (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
15052 TYPE_PTRMEMFUNC_OBJECT_TYPE (arg), UNIFY_ALLOW_NONE))
15055 /* Determine the type of the function we are unifying against. */
15056 method_type = TREE_TYPE (TYPE_PTRMEMFUNC_FN_TYPE (arg));
15058 build_function_type (TREE_TYPE (method_type),
15059 TREE_CHAIN (TYPE_ARG_TYPES (method_type)));
15061 /* Extract the cv-qualifiers of the member function from the
15062 implicit object parameter and place them on the function
15063 type to be restored later. */
15065 cp_type_quals(TREE_TYPE (TREE_VALUE (TYPE_ARG_TYPES (method_type))));
15066 fntype = build_qualified_type (fntype, cv_quals);
15067 return unify (tparms, targs, TREE_TYPE (parm), fntype, strict);
15070 if (TREE_CODE (arg) != OFFSET_TYPE)
15072 if (unify (tparms, targs, TYPE_OFFSET_BASETYPE (parm),
15073 TYPE_OFFSET_BASETYPE (arg), UNIFY_ALLOW_NONE))
15075 return unify (tparms, targs, TREE_TYPE (parm), TREE_TYPE (arg),
15079 if (DECL_TEMPLATE_PARM_P (parm))
15080 return unify (tparms, targs, DECL_INITIAL (parm), arg, strict);
15081 if (arg != integral_constant_value (parm))
15086 case TEMPLATE_DECL:
15087 /* Matched cases are handled by the ARG == PARM test above. */
15091 /* A non-type template parameter that is a variable should be a
15092 an integral constant, in which case, it whould have been
15093 folded into its (constant) value. So we should not be getting
15094 a variable here. */
15095 gcc_unreachable ();
15097 case TYPE_ARGUMENT_PACK:
15098 case NONTYPE_ARGUMENT_PACK:
15100 tree packed_parms = ARGUMENT_PACK_ARGS (parm);
15101 tree packed_args = ARGUMENT_PACK_ARGS (arg);
15102 int i, len = TREE_VEC_LENGTH (packed_parms);
15103 int argslen = TREE_VEC_LENGTH (packed_args);
15104 int parm_variadic_p = 0;
15106 for (i = 0; i < len; ++i)
15108 if (PACK_EXPANSION_P (TREE_VEC_ELT (packed_parms, i)))
15111 /* We can unify against something with a trailing
15113 parm_variadic_p = 1;
15115 /* Since there is something following the pack
15116 expansion, we cannot unify this template argument
15123 /* If we don't have enough arguments to satisfy the parameters
15124 (not counting the pack expression at the end), or we have
15125 too many arguments for a parameter list that doesn't end in
15126 a pack expression, we can't unify. */
15127 if (argslen < (len - parm_variadic_p)
15128 || (argslen > len && !parm_variadic_p))
15131 /* Unify all of the parameters that precede the (optional)
15132 pack expression. */
15133 for (i = 0; i < len - parm_variadic_p; ++i)
15135 if (unify (tparms, targs, TREE_VEC_ELT (packed_parms, i),
15136 TREE_VEC_ELT (packed_args, i), strict))
15140 if (parm_variadic_p)
15141 return unify_pack_expansion (tparms, targs,
15142 packed_parms, packed_args,
15143 strict, /*call_args_p=*/false,
15151 case DECLTYPE_TYPE:
15152 /* Cannot deduce anything from TYPEOF_TYPE or DECLTYPE_TYPE
15157 /* Unification fails if we hit an error node. */
15161 gcc_assert (EXPR_P (parm));
15163 /* We must be looking at an expression. This can happen with
15167 void foo(S<I>, S<I + 2>);
15169 This is a "nondeduced context":
15173 The nondeduced contexts are:
15175 --A type that is a template-id in which one or more of
15176 the template-arguments is an expression that references
15177 a template-parameter.
15179 In these cases, we assume deduction succeeded, but don't
15180 actually infer any unifications. */
15182 if (!uses_template_parms (parm)
15183 && !template_args_equal (parm, arg))
15190 /* Note that DECL can be defined in this translation unit, if
15194 mark_definable (tree decl)
15197 DECL_NOT_REALLY_EXTERN (decl) = 1;
15198 FOR_EACH_CLONE (clone, decl)
15199 DECL_NOT_REALLY_EXTERN (clone) = 1;
15202 /* Called if RESULT is explicitly instantiated, or is a member of an
15203 explicitly instantiated class. */
15206 mark_decl_instantiated (tree result, int extern_p)
15208 SET_DECL_EXPLICIT_INSTANTIATION (result);
15210 /* If this entity has already been written out, it's too late to
15211 make any modifications. */
15212 if (TREE_ASM_WRITTEN (result))
15215 if (TREE_CODE (result) != FUNCTION_DECL)
15216 /* The TREE_PUBLIC flag for function declarations will have been
15217 set correctly by tsubst. */
15218 TREE_PUBLIC (result) = 1;
15220 /* This might have been set by an earlier implicit instantiation. */
15221 DECL_COMDAT (result) = 0;
15224 DECL_NOT_REALLY_EXTERN (result) = 0;
15227 mark_definable (result);
15228 /* Always make artificials weak. */
15229 if (DECL_ARTIFICIAL (result) && flag_weak)
15230 comdat_linkage (result);
15231 /* For WIN32 we also want to put explicit instantiations in
15232 linkonce sections. */
15233 else if (TREE_PUBLIC (result))
15234 maybe_make_one_only (result);
15237 /* If EXTERN_P, then this function will not be emitted -- unless
15238 followed by an explicit instantiation, at which point its linkage
15239 will be adjusted. If !EXTERN_P, then this function will be
15240 emitted here. In neither circumstance do we want
15241 import_export_decl to adjust the linkage. */
15242 DECL_INTERFACE_KNOWN (result) = 1;
15245 /* Subroutine of more_specialized_fn: check whether TARGS is missing any
15246 important template arguments. If any are missing, we check whether
15247 they're important by using error_mark_node for substituting into any
15248 args that were used for partial ordering (the ones between ARGS and END)
15249 and seeing if it bubbles up. */
15252 check_undeduced_parms (tree targs, tree args, tree end)
15254 bool found = false;
15256 for (i = TREE_VEC_LENGTH (targs) - 1; i >= 0; --i)
15257 if (TREE_VEC_ELT (targs, i) == NULL_TREE)
15260 TREE_VEC_ELT (targs, i) = error_mark_node;
15264 for (; args != end; args = TREE_CHAIN (args))
15266 tree substed = tsubst (TREE_VALUE (args), targs, tf_none, NULL_TREE);
15267 if (substed == error_mark_node)
15274 /* Given two function templates PAT1 and PAT2, return:
15276 1 if PAT1 is more specialized than PAT2 as described in [temp.func.order].
15277 -1 if PAT2 is more specialized than PAT1.
15278 0 if neither is more specialized.
15280 LEN indicates the number of parameters we should consider
15281 (defaulted parameters should not be considered).
15283 The 1998 std underspecified function template partial ordering, and
15284 DR214 addresses the issue. We take pairs of arguments, one from
15285 each of the templates, and deduce them against each other. One of
15286 the templates will be more specialized if all the *other*
15287 template's arguments deduce against its arguments and at least one
15288 of its arguments *does* *not* deduce against the other template's
15289 corresponding argument. Deduction is done as for class templates.
15290 The arguments used in deduction have reference and top level cv
15291 qualifiers removed. Iff both arguments were originally reference
15292 types *and* deduction succeeds in both directions, the template
15293 with the more cv-qualified argument wins for that pairing (if
15294 neither is more cv-qualified, they both are equal). Unlike regular
15295 deduction, after all the arguments have been deduced in this way,
15296 we do *not* verify the deduced template argument values can be
15297 substituted into non-deduced contexts.
15299 The logic can be a bit confusing here, because we look at deduce1 and
15300 targs1 to see if pat2 is at least as specialized, and vice versa; if we
15301 can find template arguments for pat1 to make arg1 look like arg2, that
15302 means that arg2 is at least as specialized as arg1. */
15305 more_specialized_fn (tree pat1, tree pat2, int len)
15307 tree decl1 = DECL_TEMPLATE_RESULT (pat1);
15308 tree decl2 = DECL_TEMPLATE_RESULT (pat2);
15309 tree targs1 = make_tree_vec (DECL_NTPARMS (pat1));
15310 tree targs2 = make_tree_vec (DECL_NTPARMS (pat2));
15311 tree tparms1 = DECL_INNERMOST_TEMPLATE_PARMS (pat1);
15312 tree tparms2 = DECL_INNERMOST_TEMPLATE_PARMS (pat2);
15313 tree args1 = TYPE_ARG_TYPES (TREE_TYPE (decl1));
15314 tree args2 = TYPE_ARG_TYPES (TREE_TYPE (decl2));
15315 tree origs1, origs2;
15316 bool lose1 = false;
15317 bool lose2 = false;
15319 /* Remove the this parameter from non-static member functions. If
15320 one is a non-static member function and the other is not a static
15321 member function, remove the first parameter from that function
15322 also. This situation occurs for operator functions where we
15323 locate both a member function (with this pointer) and non-member
15324 operator (with explicit first operand). */
15325 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl1))
15327 len--; /* LEN is the number of significant arguments for DECL1 */
15328 args1 = TREE_CHAIN (args1);
15329 if (!DECL_STATIC_FUNCTION_P (decl2))
15330 args2 = TREE_CHAIN (args2);
15332 else if (DECL_NONSTATIC_MEMBER_FUNCTION_P (decl2))
15334 args2 = TREE_CHAIN (args2);
15335 if (!DECL_STATIC_FUNCTION_P (decl1))
15338 args1 = TREE_CHAIN (args1);
15342 /* If only one is a conversion operator, they are unordered. */
15343 if (DECL_CONV_FN_P (decl1) != DECL_CONV_FN_P (decl2))
15346 /* Consider the return type for a conversion function */
15347 if (DECL_CONV_FN_P (decl1))
15349 args1 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl1)), args1);
15350 args2 = tree_cons (NULL_TREE, TREE_TYPE (TREE_TYPE (decl2)), args2);
15354 processing_template_decl++;
15360 /* Stop when an ellipsis is seen. */
15361 && args1 != NULL_TREE && args2 != NULL_TREE)
15363 tree arg1 = TREE_VALUE (args1);
15364 tree arg2 = TREE_VALUE (args2);
15365 int deduce1, deduce2;
15369 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
15370 && TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
15372 /* When both arguments are pack expansions, we need only
15373 unify the patterns themselves. */
15374 arg1 = PACK_EXPANSION_PATTERN (arg1);
15375 arg2 = PACK_EXPANSION_PATTERN (arg2);
15377 /* This is the last comparison we need to do. */
15381 if (TREE_CODE (arg1) == REFERENCE_TYPE)
15383 arg1 = TREE_TYPE (arg1);
15384 quals1 = cp_type_quals (arg1);
15387 if (TREE_CODE (arg2) == REFERENCE_TYPE)
15389 arg2 = TREE_TYPE (arg2);
15390 quals2 = cp_type_quals (arg2);
15393 if ((quals1 < 0) != (quals2 < 0))
15395 /* Only of the args is a reference, see if we should apply
15396 array/function pointer decay to it. This is not part of
15397 DR214, but is, IMHO, consistent with the deduction rules
15398 for the function call itself, and with our earlier
15399 implementation of the underspecified partial ordering
15400 rules. (nathan). */
15403 switch (TREE_CODE (arg1))
15406 arg1 = TREE_TYPE (arg1);
15408 case FUNCTION_TYPE:
15409 arg1 = build_pointer_type (arg1);
15418 switch (TREE_CODE (arg2))
15421 arg2 = TREE_TYPE (arg2);
15423 case FUNCTION_TYPE:
15424 arg2 = build_pointer_type (arg2);
15433 arg1 = TYPE_MAIN_VARIANT (arg1);
15434 arg2 = TYPE_MAIN_VARIANT (arg2);
15436 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION)
15438 int i, len2 = list_length (args2);
15439 tree parmvec = make_tree_vec (1);
15440 tree argvec = make_tree_vec (len2);
15443 /* Setup the parameter vector, which contains only ARG1. */
15444 TREE_VEC_ELT (parmvec, 0) = arg1;
15446 /* Setup the argument vector, which contains the remaining
15448 for (i = 0; i < len2; i++, ta = TREE_CHAIN (ta))
15449 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
15451 deduce1 = !unify_pack_expansion (tparms1, targs1, parmvec,
15452 argvec, UNIFY_ALLOW_NONE,
15453 /*call_args_p=*/false,
15456 /* We cannot deduce in the other direction, because ARG1 is
15457 a pack expansion but ARG2 is not. */
15460 else if (TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
15462 int i, len1 = list_length (args1);
15463 tree parmvec = make_tree_vec (1);
15464 tree argvec = make_tree_vec (len1);
15467 /* Setup the parameter vector, which contains only ARG1. */
15468 TREE_VEC_ELT (parmvec, 0) = arg2;
15470 /* Setup the argument vector, which contains the remaining
15472 for (i = 0; i < len1; i++, ta = TREE_CHAIN (ta))
15473 TREE_VEC_ELT (argvec, i) = TREE_VALUE (ta);
15475 deduce2 = !unify_pack_expansion (tparms2, targs2, parmvec,
15476 argvec, UNIFY_ALLOW_NONE,
15477 /*call_args_p=*/false,
15480 /* We cannot deduce in the other direction, because ARG2 is
15481 a pack expansion but ARG1 is not.*/
15487 /* The normal case, where neither argument is a pack
15489 deduce1 = !unify (tparms1, targs1, arg1, arg2, UNIFY_ALLOW_NONE);
15490 deduce2 = !unify (tparms2, targs2, arg2, arg1, UNIFY_ALLOW_NONE);
15493 /* If we couldn't deduce arguments for tparms1 to make arg1 match
15494 arg2, then arg2 is not as specialized as arg1. */
15500 /* "If, for a given type, deduction succeeds in both directions
15501 (i.e., the types are identical after the transformations above)
15502 and if the type from the argument template is more cv-qualified
15503 than the type from the parameter template (as described above)
15504 that type is considered to be more specialized than the other. If
15505 neither type is more cv-qualified than the other then neither type
15506 is more specialized than the other." */
15508 if (deduce1 && deduce2
15509 && quals1 != quals2 && quals1 >= 0 && quals2 >= 0)
15511 if ((quals1 & quals2) == quals2)
15513 if ((quals1 & quals2) == quals1)
15517 if (lose1 && lose2)
15518 /* We've failed to deduce something in either direction.
15519 These must be unordered. */
15522 if (TREE_CODE (arg1) == TYPE_PACK_EXPANSION
15523 || TREE_CODE (arg2) == TYPE_PACK_EXPANSION)
15524 /* We have already processed all of the arguments in our
15525 handing of the pack expansion type. */
15528 args1 = TREE_CHAIN (args1);
15529 args2 = TREE_CHAIN (args2);
15532 /* "In most cases, all template parameters must have values in order for
15533 deduction to succeed, but for partial ordering purposes a template
15534 parameter may remain without a value provided it is not used in the
15535 types being used for partial ordering."
15537 Thus, if we are missing any of the targs1 we need to substitute into
15538 origs1, then pat2 is not as specialized as pat1. This can happen when
15539 there is a nondeduced context. */
15540 if (!lose2 && check_undeduced_parms (targs1, origs1, args1))
15542 if (!lose1 && check_undeduced_parms (targs2, origs2, args2))
15545 processing_template_decl--;
15547 /* All things being equal, if the next argument is a pack expansion
15548 for one function but not for the other, prefer the
15549 non-variadic function. FIXME this is bogus; see c++/41958. */
15551 && args1 && TREE_VALUE (args1)
15552 && args2 && TREE_VALUE (args2))
15554 lose1 = TREE_CODE (TREE_VALUE (args1)) == TYPE_PACK_EXPANSION;
15555 lose2 = TREE_CODE (TREE_VALUE (args2)) == TYPE_PACK_EXPANSION;
15558 if (lose1 == lose2)
15566 /* Determine which of two partial specializations is more specialized.
15568 PAT1 is a TREE_LIST whose TREE_TYPE is the _TYPE node corresponding
15569 to the first partial specialization. The TREE_VALUE is the
15570 innermost set of template parameters for the partial
15571 specialization. PAT2 is similar, but for the second template.
15573 Return 1 if the first partial specialization is more specialized;
15574 -1 if the second is more specialized; 0 if neither is more
15577 See [temp.class.order] for information about determining which of
15578 two templates is more specialized. */
15581 more_specialized_class (tree pat1, tree pat2)
15586 bool any_deductions = false;
15588 tmpl1 = TREE_TYPE (pat1);
15589 tmpl2 = TREE_TYPE (pat2);
15591 /* Just like what happens for functions, if we are ordering between
15592 different class template specializations, we may encounter dependent
15593 types in the arguments, and we need our dependency check functions
15594 to behave correctly. */
15595 ++processing_template_decl;
15596 targs = get_class_bindings (TREE_VALUE (pat1),
15597 CLASSTYPE_TI_ARGS (tmpl1),
15598 CLASSTYPE_TI_ARGS (tmpl2));
15602 any_deductions = true;
15605 targs = get_class_bindings (TREE_VALUE (pat2),
15606 CLASSTYPE_TI_ARGS (tmpl2),
15607 CLASSTYPE_TI_ARGS (tmpl1));
15611 any_deductions = true;
15613 --processing_template_decl;
15615 /* In the case of a tie where at least one of the class templates
15616 has a parameter pack at the end, the template with the most
15617 non-packed parameters wins. */
15620 && (template_args_variadic_p (TREE_PURPOSE (pat1))
15621 || template_args_variadic_p (TREE_PURPOSE (pat2))))
15623 tree args1 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat1));
15624 tree args2 = INNERMOST_TEMPLATE_ARGS (TREE_PURPOSE (pat2));
15625 int len1 = TREE_VEC_LENGTH (args1);
15626 int len2 = TREE_VEC_LENGTH (args2);
15628 /* We don't count the pack expansion at the end. */
15629 if (template_args_variadic_p (TREE_PURPOSE (pat1)))
15631 if (template_args_variadic_p (TREE_PURPOSE (pat2)))
15636 else if (len1 < len2)
15643 /* Return the template arguments that will produce the function signature
15644 DECL from the function template FN, with the explicit template
15645 arguments EXPLICIT_ARGS. If CHECK_RETTYPE is true, the return type must
15646 also match. Return NULL_TREE if no satisfactory arguments could be
15650 get_bindings (tree fn, tree decl, tree explicit_args, bool check_rettype)
15652 int ntparms = DECL_NTPARMS (fn);
15653 tree targs = make_tree_vec (ntparms);
15655 tree decl_arg_types;
15657 unsigned int nargs, ix;
15660 /* Substitute the explicit template arguments into the type of DECL.
15661 The call to fn_type_unification will handle substitution into the
15663 decl_type = TREE_TYPE (decl);
15664 if (explicit_args && uses_template_parms (decl_type))
15667 tree converted_args;
15669 if (DECL_TEMPLATE_INFO (decl))
15670 tmpl = DECL_TI_TEMPLATE (decl);
15672 /* We can get here for some invalid specializations. */
15676 = coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
15677 explicit_args, NULL_TREE,
15679 /*require_all_args=*/false,
15680 /*use_default_args=*/false);
15681 if (converted_args == error_mark_node)
15684 decl_type = tsubst (decl_type, converted_args, tf_none, NULL_TREE);
15685 if (decl_type == error_mark_node)
15689 /* Never do unification on the 'this' parameter. */
15690 decl_arg_types = skip_artificial_parms_for (decl,
15691 TYPE_ARG_TYPES (decl_type));
15693 nargs = list_length (decl_arg_types);
15694 args = XALLOCAVEC (tree, nargs);
15695 for (arg = decl_arg_types, ix = 0;
15696 arg != NULL_TREE && arg != void_list_node;
15697 arg = TREE_CHAIN (arg), ++ix)
15698 args[ix] = TREE_VALUE (arg);
15700 if (fn_type_unification (fn, explicit_args, targs,
15702 (check_rettype || DECL_CONV_FN_P (fn)
15703 ? TREE_TYPE (decl_type) : NULL_TREE),
15704 DEDUCE_EXACT, LOOKUP_NORMAL))
15710 /* Return the innermost template arguments that, when applied to a
15711 template specialization whose innermost template parameters are
15712 TPARMS, and whose specialization arguments are SPEC_ARGS, yield the
15715 For example, suppose we have:
15717 template <class T, class U> struct S {};
15718 template <class T> struct S<T*, int> {};
15720 Then, suppose we want to get `S<double*, int>'. The TPARMS will be
15721 {T}, the SPEC_ARGS will be {T*, int} and the ARGS will be {double*,
15722 int}. The resulting vector will be {double}, indicating that `T'
15723 is bound to `double'. */
15726 get_class_bindings (tree tparms, tree spec_args, tree args)
15728 int i, ntparms = TREE_VEC_LENGTH (tparms);
15730 tree innermost_deduced_args;
15732 innermost_deduced_args = make_tree_vec (ntparms);
15733 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
15735 deduced_args = copy_node (args);
15736 SET_TMPL_ARGS_LEVEL (deduced_args,
15737 TMPL_ARGS_DEPTH (deduced_args),
15738 innermost_deduced_args);
15741 deduced_args = innermost_deduced_args;
15743 if (unify (tparms, deduced_args,
15744 INNERMOST_TEMPLATE_ARGS (spec_args),
15745 INNERMOST_TEMPLATE_ARGS (args),
15749 for (i = 0; i < ntparms; ++i)
15750 if (! TREE_VEC_ELT (innermost_deduced_args, i))
15753 /* Verify that nondeduced template arguments agree with the type
15754 obtained from argument deduction.
15758 struct A { typedef int X; };
15759 template <class T, class U> struct C {};
15760 template <class T> struct C<T, typename T::X> {};
15762 Then with the instantiation `C<A, int>', we can deduce that
15763 `T' is `A' but unify () does not check whether `typename T::X'
15765 spec_args = tsubst (spec_args, deduced_args, tf_none, NULL_TREE);
15766 if (spec_args == error_mark_node
15767 /* We only need to check the innermost arguments; the other
15768 arguments will always agree. */
15769 || !comp_template_args (INNERMOST_TEMPLATE_ARGS (spec_args),
15770 INNERMOST_TEMPLATE_ARGS (args)))
15773 /* Now that we have bindings for all of the template arguments,
15774 ensure that the arguments deduced for the template template
15775 parameters have compatible template parameter lists. See the use
15776 of template_template_parm_bindings_ok_p in fn_type_unification
15777 for more information. */
15778 if (!template_template_parm_bindings_ok_p (tparms, deduced_args))
15781 return deduced_args;
15784 /* TEMPLATES is a TREE_LIST. Each TREE_VALUE is a TEMPLATE_DECL.
15785 Return the TREE_LIST node with the most specialized template, if
15786 any. If there is no most specialized template, the error_mark_node
15789 Note that this function does not look at, or modify, the
15790 TREE_PURPOSE or TREE_TYPE of any of the nodes. Since the node
15791 returned is one of the elements of INSTANTIATIONS, callers may
15792 store information in the TREE_PURPOSE or TREE_TYPE of the nodes,
15793 and retrieve it from the value returned. */
15796 most_specialized_instantiation (tree templates)
15800 ++processing_template_decl;
15803 for (fn = TREE_CHAIN (templates); fn; fn = TREE_CHAIN (fn))
15807 if (get_bindings (TREE_VALUE (champ),
15808 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
15809 NULL_TREE, /*check_ret=*/false))
15812 if (get_bindings (TREE_VALUE (fn),
15813 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
15814 NULL_TREE, /*check_ret=*/false))
15821 /* Equally specialized, move to next function. If there
15822 is no next function, nothing's most specialized. */
15823 fn = TREE_CHAIN (fn);
15831 /* Now verify that champ is better than everything earlier in the
15832 instantiation list. */
15833 for (fn = templates; fn != champ; fn = TREE_CHAIN (fn))
15834 if (get_bindings (TREE_VALUE (champ),
15835 DECL_TEMPLATE_RESULT (TREE_VALUE (fn)),
15836 NULL_TREE, /*check_ret=*/false)
15837 || !get_bindings (TREE_VALUE (fn),
15838 DECL_TEMPLATE_RESULT (TREE_VALUE (champ)),
15839 NULL_TREE, /*check_ret=*/false))
15845 processing_template_decl--;
15848 return error_mark_node;
15853 /* If DECL is a specialization of some template, return the most
15854 general such template. Otherwise, returns NULL_TREE.
15856 For example, given:
15858 template <class T> struct S { template <class U> void f(U); };
15860 if TMPL is `template <class U> void S<int>::f(U)' this will return
15861 the full template. This function will not trace past partial
15862 specializations, however. For example, given in addition:
15864 template <class T> struct S<T*> { template <class U> void f(U); };
15866 if TMPL is `template <class U> void S<int*>::f(U)' this will return
15867 `template <class T> template <class U> S<T*>::f(U)'. */
15870 most_general_template (tree decl)
15872 /* If DECL is a FUNCTION_DECL, find the TEMPLATE_DECL of which it is
15873 an immediate specialization. */
15874 if (TREE_CODE (decl) == FUNCTION_DECL)
15876 if (DECL_TEMPLATE_INFO (decl)) {
15877 decl = DECL_TI_TEMPLATE (decl);
15879 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE for a
15880 template friend. */
15881 if (TREE_CODE (decl) != TEMPLATE_DECL)
15887 /* Look for more and more general templates. */
15888 while (DECL_TEMPLATE_INFO (decl))
15890 /* The DECL_TI_TEMPLATE can be an IDENTIFIER_NODE in some cases.
15891 (See cp-tree.h for details.) */
15892 if (TREE_CODE (DECL_TI_TEMPLATE (decl)) != TEMPLATE_DECL)
15895 if (CLASS_TYPE_P (TREE_TYPE (decl))
15896 && CLASSTYPE_TEMPLATE_SPECIALIZATION (TREE_TYPE (decl)))
15899 /* Stop if we run into an explicitly specialized class template. */
15900 if (!DECL_NAMESPACE_SCOPE_P (decl)
15901 && DECL_CONTEXT (decl)
15902 && CLASSTYPE_TEMPLATE_SPECIALIZATION (DECL_CONTEXT (decl)))
15905 decl = DECL_TI_TEMPLATE (decl);
15911 /* Return the most specialized of the class template partial
15912 specializations of TMPL which can produce TYPE, a specialization of
15913 TMPL. The value returned is actually a TREE_LIST; the TREE_TYPE is
15914 a _TYPE node corresponding to the partial specialization, while the
15915 TREE_PURPOSE is the set of template arguments that must be
15916 substituted into the TREE_TYPE in order to generate TYPE.
15918 If the choice of partial specialization is ambiguous, a diagnostic
15919 is issued, and the error_mark_node is returned. If there are no
15920 partial specializations of TMPL matching TYPE, then NULL_TREE is
15924 most_specialized_class (tree type, tree tmpl)
15926 tree list = NULL_TREE;
15932 tree outer_args = NULL_TREE;
15934 tmpl = most_general_template (tmpl);
15935 args = CLASSTYPE_TI_ARGS (type);
15937 /* For determining which partial specialization to use, only the
15938 innermost args are interesting. */
15939 if (TMPL_ARGS_HAVE_MULTIPLE_LEVELS (args))
15941 outer_args = strip_innermost_template_args (args, 1);
15942 args = INNERMOST_TEMPLATE_ARGS (args);
15945 for (t = DECL_TEMPLATE_SPECIALIZATIONS (tmpl); t; t = TREE_CHAIN (t))
15947 tree partial_spec_args;
15949 tree parms = TREE_VALUE (t);
15951 partial_spec_args = CLASSTYPE_TI_ARGS (TREE_TYPE (t));
15953 ++processing_template_decl;
15959 /* Discard the outer levels of args, and then substitute in the
15960 template args from the enclosing class. */
15961 partial_spec_args = INNERMOST_TEMPLATE_ARGS (partial_spec_args);
15962 partial_spec_args = tsubst_template_args
15963 (partial_spec_args, outer_args, tf_none, NULL_TREE);
15965 /* PARMS already refers to just the innermost parms, but the
15966 template parms in partial_spec_args had their levels lowered
15967 by tsubst, so we need to do the same for the parm list. We
15968 can't just tsubst the TREE_VEC itself, as tsubst wants to
15969 treat a TREE_VEC as an argument vector. */
15970 parms = copy_node (parms);
15971 for (i = TREE_VEC_LENGTH (parms) - 1; i >= 0; --i)
15972 TREE_VEC_ELT (parms, i) =
15973 tsubst (TREE_VEC_ELT (parms, i), outer_args, tf_none, NULL_TREE);
15977 partial_spec_args =
15978 coerce_template_parms (DECL_INNERMOST_TEMPLATE_PARMS (tmpl),
15979 add_to_template_args (outer_args,
15980 partial_spec_args),
15982 /*require_all_args=*/true,
15983 /*use_default_args=*/true);
15985 if (partial_spec_args == error_mark_node)
15986 return error_mark_node;
15988 spec_args = get_class_bindings (parms,
15994 spec_args = add_to_template_args (outer_args, spec_args);
15995 list = tree_cons (spec_args, TREE_VALUE (t), list);
15996 TREE_TYPE (list) = TREE_TYPE (t);
16003 ambiguous_p = false;
16006 t = TREE_CHAIN (t);
16007 for (; t; t = TREE_CHAIN (t))
16009 fate = more_specialized_class (champ, t);
16016 t = TREE_CHAIN (t);
16019 ambiguous_p = true;
16028 for (t = list; t && t != champ; t = TREE_CHAIN (t))
16030 fate = more_specialized_class (champ, t);
16033 ambiguous_p = true;
16041 char *spaces = NULL;
16042 error ("ambiguous class template instantiation for %q#T", type);
16043 str = TREE_CHAIN (list) ? _("candidates are:") : _("candidate is:");
16044 for (t = list; t; t = TREE_CHAIN (t))
16046 error ("%s %+#T", spaces ? spaces : str, TREE_TYPE (t));
16047 spaces = spaces ? spaces : get_spaces (str);
16050 return error_mark_node;
16056 /* Explicitly instantiate DECL. */
16059 do_decl_instantiation (tree decl, tree storage)
16061 tree result = NULL_TREE;
16064 if (!decl || decl == error_mark_node)
16065 /* An error occurred, for which grokdeclarator has already issued
16066 an appropriate message. */
16068 else if (! DECL_LANG_SPECIFIC (decl))
16070 error ("explicit instantiation of non-template %q#D", decl);
16073 else if (TREE_CODE (decl) == VAR_DECL)
16075 /* There is an asymmetry here in the way VAR_DECLs and
16076 FUNCTION_DECLs are handled by grokdeclarator. In the case of
16077 the latter, the DECL we get back will be marked as a
16078 template instantiation, and the appropriate
16079 DECL_TEMPLATE_INFO will be set up. This does not happen for
16080 VAR_DECLs so we do the lookup here. Probably, grokdeclarator
16081 should handle VAR_DECLs as it currently handles
16083 if (!DECL_CLASS_SCOPE_P (decl))
16085 error ("%qD is not a static data member of a class template", decl);
16088 result = lookup_field (DECL_CONTEXT (decl), DECL_NAME (decl), 0, false);
16089 if (!result || TREE_CODE (result) != VAR_DECL)
16091 error ("no matching template for %qD found", decl);
16094 if (!same_type_p (TREE_TYPE (result), TREE_TYPE (decl)))
16096 error ("type %qT for explicit instantiation %qD does not match "
16097 "declared type %qT", TREE_TYPE (result), decl,
16102 else if (TREE_CODE (decl) != FUNCTION_DECL)
16104 error ("explicit instantiation of %q#D", decl);
16110 /* Check for various error cases. Note that if the explicit
16111 instantiation is valid the RESULT will currently be marked as an
16112 *implicit* instantiation; DECL_EXPLICIT_INSTANTIATION is not set
16113 until we get here. */
16115 if (DECL_TEMPLATE_SPECIALIZATION (result))
16117 /* DR 259 [temp.spec].
16119 Both an explicit instantiation and a declaration of an explicit
16120 specialization shall not appear in a program unless the explicit
16121 instantiation follows a declaration of the explicit specialization.
16123 For a given set of template parameters, if an explicit
16124 instantiation of a template appears after a declaration of an
16125 explicit specialization for that template, the explicit
16126 instantiation has no effect. */
16129 else if (DECL_EXPLICIT_INSTANTIATION (result))
16133 No program shall explicitly instantiate any template more
16136 We check DECL_NOT_REALLY_EXTERN so as not to complain when
16137 the first instantiation was `extern' and the second is not,
16138 and EXTERN_P for the opposite case. */
16139 if (DECL_NOT_REALLY_EXTERN (result) && !extern_p)
16140 permerror (input_location, "duplicate explicit instantiation of %q#D", result);
16141 /* If an "extern" explicit instantiation follows an ordinary
16142 explicit instantiation, the template is instantiated. */
16146 else if (!DECL_IMPLICIT_INSTANTIATION (result))
16148 error ("no matching template for %qD found", result);
16151 else if (!DECL_TEMPLATE_INFO (result))
16153 permerror (input_location, "explicit instantiation of non-template %q#D", result);
16157 if (storage == NULL_TREE)
16159 else if (storage == ridpointers[(int) RID_EXTERN])
16161 if (!in_system_header && (cxx_dialect == cxx98))
16162 pedwarn (input_location, OPT_pedantic,
16163 "ISO C++ 1998 forbids the use of %<extern%> on explicit "
16168 error ("storage class %qD applied to template instantiation", storage);
16170 check_explicit_instantiation_namespace (result);
16171 mark_decl_instantiated (result, extern_p);
16173 instantiate_decl (result, /*defer_ok=*/1,
16174 /*expl_inst_class_mem_p=*/false);
16178 mark_class_instantiated (tree t, int extern_p)
16180 SET_CLASSTYPE_EXPLICIT_INSTANTIATION (t);
16181 SET_CLASSTYPE_INTERFACE_KNOWN (t);
16182 CLASSTYPE_INTERFACE_ONLY (t) = extern_p;
16183 TYPE_DECL_SUPPRESS_DEBUG (TYPE_NAME (t)) = extern_p;
16186 CLASSTYPE_DEBUG_REQUESTED (t) = 1;
16187 rest_of_type_compilation (t, 1);
16191 /* Called from do_type_instantiation through binding_table_foreach to
16192 do recursive instantiation for the type bound in ENTRY. */
16194 bt_instantiate_type_proc (binding_entry entry, void *data)
16196 tree storage = *(tree *) data;
16198 if (MAYBE_CLASS_TYPE_P (entry->type)
16199 && !uses_template_parms (CLASSTYPE_TI_ARGS (entry->type)))
16200 do_type_instantiation (TYPE_MAIN_DECL (entry->type), storage, 0);
16203 /* Called from do_type_instantiation to instantiate a member
16204 (a member function or a static member variable) of an
16205 explicitly instantiated class template. */
16207 instantiate_class_member (tree decl, int extern_p)
16209 mark_decl_instantiated (decl, extern_p);
16211 instantiate_decl (decl, /*defer_ok=*/1,
16212 /*expl_inst_class_mem_p=*/true);
16215 /* Perform an explicit instantiation of template class T. STORAGE, if
16216 non-null, is the RID for extern, inline or static. COMPLAIN is
16217 nonzero if this is called from the parser, zero if called recursively,
16218 since the standard is unclear (as detailed below). */
16221 do_type_instantiation (tree t, tree storage, tsubst_flags_t complain)
16226 int previous_instantiation_extern_p = 0;
16228 if (TREE_CODE (t) == TYPE_DECL)
16231 if (! CLASS_TYPE_P (t) || ! CLASSTYPE_TEMPLATE_INFO (t))
16233 error ("explicit instantiation of non-template type %qT", t);
16239 if (!COMPLETE_TYPE_P (t))
16241 if (complain & tf_error)
16242 error ("explicit instantiation of %q#T before definition of template",
16247 if (storage != NULL_TREE)
16249 if (!in_system_header)
16251 if (storage == ridpointers[(int) RID_EXTERN])
16253 if (cxx_dialect == cxx98)
16254 pedwarn (input_location, OPT_pedantic,
16255 "ISO C++ 1998 forbids the use of %<extern%> on "
16256 "explicit instantiations");
16259 pedwarn (input_location, OPT_pedantic,
16260 "ISO C++ forbids the use of %qE"
16261 " on explicit instantiations", storage);
16264 if (storage == ridpointers[(int) RID_INLINE])
16266 else if (storage == ridpointers[(int) RID_EXTERN])
16268 else if (storage == ridpointers[(int) RID_STATIC])
16272 error ("storage class %qD applied to template instantiation",
16278 if (CLASSTYPE_TEMPLATE_SPECIALIZATION (t))
16280 /* DR 259 [temp.spec].
16282 Both an explicit instantiation and a declaration of an explicit
16283 specialization shall not appear in a program unless the explicit
16284 instantiation follows a declaration of the explicit specialization.
16286 For a given set of template parameters, if an explicit
16287 instantiation of a template appears after a declaration of an
16288 explicit specialization for that template, the explicit
16289 instantiation has no effect. */
16292 else if (CLASSTYPE_EXPLICIT_INSTANTIATION (t))
16296 No program shall explicitly instantiate any template more
16299 If PREVIOUS_INSTANTIATION_EXTERN_P, then the first explicit
16300 instantiation was `extern'. If EXTERN_P then the second is.
16301 These cases are OK. */
16302 previous_instantiation_extern_p = CLASSTYPE_INTERFACE_ONLY (t);
16304 if (!previous_instantiation_extern_p && !extern_p
16305 && (complain & tf_error))
16306 permerror (input_location, "duplicate explicit instantiation of %q#T", t);
16308 /* If we've already instantiated the template, just return now. */
16309 if (!CLASSTYPE_INTERFACE_ONLY (t))
16313 check_explicit_instantiation_namespace (TYPE_NAME (t));
16314 mark_class_instantiated (t, extern_p);
16322 /* In contrast to implicit instantiation, where only the
16323 declarations, and not the definitions, of members are
16324 instantiated, we have here:
16328 The explicit instantiation of a class template specialization
16329 implies the instantiation of all of its members not
16330 previously explicitly specialized in the translation unit
16331 containing the explicit instantiation.
16333 Of course, we can't instantiate member template classes, since
16334 we don't have any arguments for them. Note that the standard
16335 is unclear on whether the instantiation of the members are
16336 *explicit* instantiations or not. However, the most natural
16337 interpretation is that it should be an explicit instantiation. */
16340 for (tmp = TYPE_METHODS (t); tmp; tmp = TREE_CHAIN (tmp))
16341 if (TREE_CODE (tmp) == FUNCTION_DECL
16342 && DECL_TEMPLATE_INSTANTIATION (tmp))
16343 instantiate_class_member (tmp, extern_p);
16345 for (tmp = TYPE_FIELDS (t); tmp; tmp = TREE_CHAIN (tmp))
16346 if (TREE_CODE (tmp) == VAR_DECL && DECL_TEMPLATE_INSTANTIATION (tmp))
16347 instantiate_class_member (tmp, extern_p);
16349 if (CLASSTYPE_NESTED_UTDS (t))
16350 binding_table_foreach (CLASSTYPE_NESTED_UTDS (t),
16351 bt_instantiate_type_proc, &storage);
16355 /* Given a function DECL, which is a specialization of TMPL, modify
16356 DECL to be a re-instantiation of TMPL with the same template
16357 arguments. TMPL should be the template into which tsubst'ing
16358 should occur for DECL, not the most general template.
16360 One reason for doing this is a scenario like this:
16363 void f(const T&, int i);
16365 void g() { f(3, 7); }
16368 void f(const T& t, const int i) { }
16370 Note that when the template is first instantiated, with
16371 instantiate_template, the resulting DECL will have no name for the
16372 first parameter, and the wrong type for the second. So, when we go
16373 to instantiate the DECL, we regenerate it. */
16376 regenerate_decl_from_template (tree decl, tree tmpl)
16378 /* The arguments used to instantiate DECL, from the most general
16383 args = DECL_TI_ARGS (decl);
16384 code_pattern = DECL_TEMPLATE_RESULT (tmpl);
16386 /* Make sure that we can see identifiers, and compute access
16388 push_access_scope (decl);
16390 if (TREE_CODE (decl) == FUNCTION_DECL)
16398 args_depth = TMPL_ARGS_DEPTH (args);
16399 parms_depth = TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (tmpl));
16400 if (args_depth > parms_depth)
16401 args = get_innermost_template_args (args, parms_depth);
16403 specs = tsubst_exception_specification (TREE_TYPE (code_pattern),
16404 args, tf_error, NULL_TREE);
16406 TREE_TYPE (decl) = build_exception_variant (TREE_TYPE (decl),
16409 /* Merge parameter declarations. */
16410 decl_parm = skip_artificial_parms_for (decl,
16411 DECL_ARGUMENTS (decl));
16413 = skip_artificial_parms_for (code_pattern,
16414 DECL_ARGUMENTS (code_pattern));
16415 while (decl_parm && !FUNCTION_PARAMETER_PACK_P (pattern_parm))
16420 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
16421 DECL_NAME (decl_parm) = DECL_NAME (pattern_parm);
16422 parm_type = tsubst (TREE_TYPE (pattern_parm), args, tf_error,
16424 parm_type = type_decays_to (parm_type);
16425 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
16426 TREE_TYPE (decl_parm) = parm_type;
16427 attributes = DECL_ATTRIBUTES (pattern_parm);
16428 if (DECL_ATTRIBUTES (decl_parm) != attributes)
16430 DECL_ATTRIBUTES (decl_parm) = attributes;
16431 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
16433 decl_parm = TREE_CHAIN (decl_parm);
16434 pattern_parm = TREE_CHAIN (pattern_parm);
16436 /* Merge any parameters that match with the function parameter
16438 if (pattern_parm && FUNCTION_PARAMETER_PACK_P (pattern_parm))
16441 tree expanded_types;
16442 /* Expand the TYPE_PACK_EXPANSION that provides the types for
16443 the parameters in this function parameter pack. */
16444 expanded_types = tsubst_pack_expansion (TREE_TYPE (pattern_parm),
16445 args, tf_error, NULL_TREE);
16446 len = TREE_VEC_LENGTH (expanded_types);
16447 for (i = 0; i < len; i++)
16452 if (DECL_NAME (decl_parm) != DECL_NAME (pattern_parm))
16453 /* Rename the parameter to include the index. */
16454 DECL_NAME (decl_parm) =
16455 make_ith_pack_parameter_name (DECL_NAME (pattern_parm), i);
16456 parm_type = TREE_VEC_ELT (expanded_types, i);
16457 parm_type = type_decays_to (parm_type);
16458 if (!same_type_p (TREE_TYPE (decl_parm), parm_type))
16459 TREE_TYPE (decl_parm) = parm_type;
16460 attributes = DECL_ATTRIBUTES (pattern_parm);
16461 if (DECL_ATTRIBUTES (decl_parm) != attributes)
16463 DECL_ATTRIBUTES (decl_parm) = attributes;
16464 cplus_decl_attributes (&decl_parm, attributes, /*flags=*/0);
16466 decl_parm = TREE_CHAIN (decl_parm);
16469 /* Merge additional specifiers from the CODE_PATTERN. */
16470 if (DECL_DECLARED_INLINE_P (code_pattern)
16471 && !DECL_DECLARED_INLINE_P (decl))
16472 DECL_DECLARED_INLINE_P (decl) = 1;
16474 else if (TREE_CODE (decl) == VAR_DECL)
16476 DECL_INITIAL (decl) =
16477 tsubst_expr (DECL_INITIAL (code_pattern), args,
16478 tf_error, DECL_TI_TEMPLATE (decl),
16479 /*integral_constant_expression_p=*/false);
16480 if (VAR_HAD_UNKNOWN_BOUND (decl))
16481 TREE_TYPE (decl) = tsubst (TREE_TYPE (code_pattern), args,
16482 tf_error, DECL_TI_TEMPLATE (decl));
16485 gcc_unreachable ();
16487 pop_access_scope (decl);
16490 /* Return the TEMPLATE_DECL into which DECL_TI_ARGS(DECL) should be
16491 substituted to get DECL. */
16494 template_for_substitution (tree decl)
16496 tree tmpl = DECL_TI_TEMPLATE (decl);
16498 /* Set TMPL to the template whose DECL_TEMPLATE_RESULT is the pattern
16499 for the instantiation. This is not always the most general
16500 template. Consider, for example:
16503 struct S { template <class U> void f();
16504 template <> void f<int>(); };
16506 and an instantiation of S<double>::f<int>. We want TD to be the
16507 specialization S<T>::f<int>, not the more general S<T>::f<U>. */
16508 while (/* An instantiation cannot have a definition, so we need a
16509 more general template. */
16510 DECL_TEMPLATE_INSTANTIATION (tmpl)
16511 /* We must also deal with friend templates. Given:
16513 template <class T> struct S {
16514 template <class U> friend void f() {};
16517 S<int>::f<U> say, is not an instantiation of S<T>::f<U>,
16518 so far as the language is concerned, but that's still
16519 where we get the pattern for the instantiation from. On
16520 other hand, if the definition comes outside the class, say:
16522 template <class T> struct S {
16523 template <class U> friend void f();
16525 template <class U> friend void f() {}
16527 we don't need to look any further. That's what the check for
16528 DECL_INITIAL is for. */
16529 || (TREE_CODE (decl) == FUNCTION_DECL
16530 && DECL_FRIEND_PSEUDO_TEMPLATE_INSTANTIATION (tmpl)
16531 && !DECL_INITIAL (DECL_TEMPLATE_RESULT (tmpl))))
16533 /* The present template, TD, should not be a definition. If it
16534 were a definition, we should be using it! Note that we
16535 cannot restructure the loop to just keep going until we find
16536 a template with a definition, since that might go too far if
16537 a specialization was declared, but not defined. */
16538 gcc_assert (TREE_CODE (decl) != VAR_DECL
16539 || DECL_IN_AGGR_P (DECL_TEMPLATE_RESULT (tmpl)));
16541 /* Fetch the more general template. */
16542 tmpl = DECL_TI_TEMPLATE (tmpl);
16548 /* Returns true if we need to instantiate this template instance even if we
16549 know we aren't going to emit it.. */
16552 always_instantiate_p (tree decl)
16554 /* We always instantiate inline functions so that we can inline them. An
16555 explicit instantiation declaration prohibits implicit instantiation of
16556 non-inline functions. With high levels of optimization, we would
16557 normally inline non-inline functions -- but we're not allowed to do
16558 that for "extern template" functions. Therefore, we check
16559 DECL_DECLARED_INLINE_P, rather than possibly_inlined_p. */
16560 return ((TREE_CODE (decl) == FUNCTION_DECL
16561 && DECL_DECLARED_INLINE_P (decl))
16562 /* And we need to instantiate static data members so that
16563 their initializers are available in integral constant
16565 || (TREE_CODE (decl) == VAR_DECL
16566 && DECL_INITIALIZED_BY_CONSTANT_EXPRESSION_P (decl)));
16569 /* Produce the definition of D, a _DECL generated from a template. If
16570 DEFER_OK is nonzero, then we don't have to actually do the
16571 instantiation now; we just have to do it sometime. Normally it is
16572 an error if this is an explicit instantiation but D is undefined.
16573 EXPL_INST_CLASS_MEM_P is true iff D is a member of an
16574 explicitly instantiated class template. */
16577 instantiate_decl (tree d, int defer_ok,
16578 bool expl_inst_class_mem_p)
16580 tree tmpl = DECL_TI_TEMPLATE (d);
16587 bool pattern_defined;
16589 location_t saved_loc = input_location;
16592 /* This function should only be used to instantiate templates for
16593 functions and static member variables. */
16594 gcc_assert (TREE_CODE (d) == FUNCTION_DECL
16595 || TREE_CODE (d) == VAR_DECL);
16597 /* Variables are never deferred; if instantiation is required, they
16598 are instantiated right away. That allows for better code in the
16599 case that an expression refers to the value of the variable --
16600 if the variable has a constant value the referring expression can
16601 take advantage of that fact. */
16602 if (TREE_CODE (d) == VAR_DECL)
16605 /* Don't instantiate cloned functions. Instead, instantiate the
16606 functions they cloned. */
16607 if (TREE_CODE (d) == FUNCTION_DECL && DECL_CLONED_FUNCTION_P (d))
16608 d = DECL_CLONED_FUNCTION (d);
16610 if (DECL_TEMPLATE_INSTANTIATED (d)
16611 || DECL_TEMPLATE_SPECIALIZATION (d))
16612 /* D has already been instantiated or explicitly specialized, so
16613 there's nothing for us to do here.
16615 It might seem reasonable to check whether or not D is an explicit
16616 instantiation, and, if so, stop here. But when an explicit
16617 instantiation is deferred until the end of the compilation,
16618 DECL_EXPLICIT_INSTANTIATION is set, even though we still need to do
16619 the instantiation. */
16622 /* Check to see whether we know that this template will be
16623 instantiated in some other file, as with "extern template"
16625 external_p = (DECL_INTERFACE_KNOWN (d) && DECL_REALLY_EXTERN (d));
16627 /* In general, we do not instantiate such templates. */
16628 if (external_p && !always_instantiate_p (d))
16631 gen_tmpl = most_general_template (tmpl);
16632 gen_args = DECL_TI_ARGS (d);
16634 if (tmpl != gen_tmpl)
16635 /* We should already have the extra args. */
16636 gcc_assert (TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (gen_tmpl))
16637 == TMPL_ARGS_DEPTH (gen_args));
16638 /* And what's in the hash table should match D. */
16639 gcc_assert ((spec = retrieve_specialization (gen_tmpl, gen_args, 0)) == d
16640 || spec == NULL_TREE);
16642 /* This needs to happen before any tsubsting. */
16643 if (! push_tinst_level (d))
16646 timevar_push (TV_PARSE);
16648 /* Set TD to the template whose DECL_TEMPLATE_RESULT is the pattern
16649 for the instantiation. */
16650 td = template_for_substitution (d);
16651 code_pattern = DECL_TEMPLATE_RESULT (td);
16653 /* We should never be trying to instantiate a member of a class
16654 template or partial specialization. */
16655 gcc_assert (d != code_pattern);
16657 if ((DECL_NAMESPACE_SCOPE_P (d) && !DECL_INITIALIZED_IN_CLASS_P (d))
16658 || DECL_TEMPLATE_SPECIALIZATION (td))
16659 /* In the case of a friend template whose definition is provided
16660 outside the class, we may have too many arguments. Drop the
16661 ones we don't need. The same is true for specializations. */
16662 args = get_innermost_template_args
16663 (gen_args, TMPL_PARMS_DEPTH (DECL_TEMPLATE_PARMS (td)));
16667 if (TREE_CODE (d) == FUNCTION_DECL)
16668 pattern_defined = (DECL_SAVED_TREE (code_pattern) != NULL_TREE);
16670 pattern_defined = ! DECL_IN_AGGR_P (code_pattern);
16672 /* We may be in the middle of deferred access check. Disable it now. */
16673 push_deferring_access_checks (dk_no_deferred);
16675 /* Unless an explicit instantiation directive has already determined
16676 the linkage of D, remember that a definition is available for
16678 if (pattern_defined
16679 && !DECL_INTERFACE_KNOWN (d)
16680 && !DECL_NOT_REALLY_EXTERN (d))
16681 mark_definable (d);
16683 input_location = DECL_SOURCE_LOCATION (d);
16685 /* If D is a member of an explicitly instantiated class template,
16686 and no definition is available, treat it like an implicit
16688 if (!pattern_defined && expl_inst_class_mem_p
16689 && DECL_EXPLICIT_INSTANTIATION (d))
16691 DECL_NOT_REALLY_EXTERN (d) = 0;
16692 DECL_INTERFACE_KNOWN (d) = 0;
16693 SET_DECL_IMPLICIT_INSTANTIATION (d);
16696 /* Recheck the substitutions to obtain any warning messages
16697 about ignoring cv qualifiers. Don't do this for artificial decls,
16698 as it breaks the context-sensitive substitution for lambda op(). */
16699 if (!defer_ok && !DECL_ARTIFICIAL (d))
16701 tree gen = DECL_TEMPLATE_RESULT (gen_tmpl);
16702 tree type = TREE_TYPE (gen);
16704 /* Make sure that we can see identifiers, and compute access
16705 correctly. D is already the target FUNCTION_DECL with the
16707 push_access_scope (d);
16709 if (TREE_CODE (gen) == FUNCTION_DECL)
16711 tsubst (DECL_ARGUMENTS (gen), gen_args, tf_warning_or_error, d);
16712 tsubst_exception_specification (type, gen_args, tf_warning_or_error,
16714 /* Don't simply tsubst the function type, as that will give
16715 duplicate warnings about poor parameter qualifications.
16716 The function arguments are the same as the decl_arguments
16717 without the top level cv qualifiers. */
16718 type = TREE_TYPE (type);
16720 tsubst (type, gen_args, tf_warning_or_error, d);
16722 pop_access_scope (d);
16725 /* Defer all other templates, unless we have been explicitly
16726 forbidden from doing so. */
16727 if (/* If there is no definition, we cannot instantiate the
16730 /* If it's OK to postpone instantiation, do so. */
16732 /* If this is a static data member that will be defined
16733 elsewhere, we don't want to instantiate the entire data
16734 member, but we do want to instantiate the initializer so that
16735 we can substitute that elsewhere. */
16736 || (external_p && TREE_CODE (d) == VAR_DECL))
16738 /* The definition of the static data member is now required so
16739 we must substitute the initializer. */
16740 if (TREE_CODE (d) == VAR_DECL
16741 && !DECL_INITIAL (d)
16742 && DECL_INITIAL (code_pattern))
16747 ns = decl_namespace_context (d);
16748 push_nested_namespace (ns);
16749 push_nested_class (DECL_CONTEXT (d));
16750 init = tsubst_expr (DECL_INITIAL (code_pattern),
16752 tf_warning_or_error, NULL_TREE,
16753 /*integral_constant_expression_p=*/false);
16754 cp_finish_decl (d, init, /*init_const_expr_p=*/false,
16755 /*asmspec_tree=*/NULL_TREE,
16756 LOOKUP_ONLYCONVERTING);
16757 pop_nested_class ();
16758 pop_nested_namespace (ns);
16761 /* We restore the source position here because it's used by
16762 add_pending_template. */
16763 input_location = saved_loc;
16765 if (at_eof && !pattern_defined
16766 && DECL_EXPLICIT_INSTANTIATION (d)
16767 && DECL_NOT_REALLY_EXTERN (d))
16770 The definition of a non-exported function template, a
16771 non-exported member function template, or a non-exported
16772 member function or static data member of a class template
16773 shall be present in every translation unit in which it is
16774 explicitly instantiated. */
16775 permerror (input_location, "explicit instantiation of %qD "
16776 "but no definition available", d);
16778 /* ??? Historically, we have instantiated inline functions, even
16779 when marked as "extern template". */
16780 if (!(external_p && TREE_CODE (d) == VAR_DECL))
16781 add_pending_template (d);
16784 /* Tell the repository that D is available in this translation unit
16785 -- and see if it is supposed to be instantiated here. */
16786 if (TREE_PUBLIC (d) && !DECL_REALLY_EXTERN (d) && !repo_emit_p (d))
16788 /* In a PCH file, despite the fact that the repository hasn't
16789 requested instantiation in the PCH it is still possible that
16790 an instantiation will be required in a file that includes the
16793 add_pending_template (d);
16794 /* Instantiate inline functions so that the inliner can do its
16795 job, even though we'll not be emitting a copy of this
16797 if (!(TREE_CODE (d) == FUNCTION_DECL && possibly_inlined_p (d)))
16801 need_push = !cfun || !global_bindings_p ();
16803 push_to_top_level ();
16805 /* Mark D as instantiated so that recursive calls to
16806 instantiate_decl do not try to instantiate it again. */
16807 DECL_TEMPLATE_INSTANTIATED (d) = 1;
16809 /* Regenerate the declaration in case the template has been modified
16810 by a subsequent redeclaration. */
16811 regenerate_decl_from_template (d, td);
16813 /* We already set the file and line above. Reset them now in case
16814 they changed as a result of calling regenerate_decl_from_template. */
16815 input_location = DECL_SOURCE_LOCATION (d);
16817 if (TREE_CODE (d) == VAR_DECL)
16821 /* Clear out DECL_RTL; whatever was there before may not be right
16822 since we've reset the type of the declaration. */
16823 SET_DECL_RTL (d, NULL_RTX);
16824 DECL_IN_AGGR_P (d) = 0;
16826 /* The initializer is placed in DECL_INITIAL by
16827 regenerate_decl_from_template. Pull it out so that
16828 cp_finish_decl can process it. */
16829 init = DECL_INITIAL (d);
16830 DECL_INITIAL (d) = NULL_TREE;
16831 DECL_INITIALIZED_P (d) = 0;
16833 /* Clear DECL_EXTERNAL so that cp_finish_decl will process the
16834 initializer. That function will defer actual emission until
16835 we have a chance to determine linkage. */
16836 DECL_EXTERNAL (d) = 0;
16838 /* Enter the scope of D so that access-checking works correctly. */
16839 push_nested_class (DECL_CONTEXT (d));
16840 cp_finish_decl (d, init, false, NULL_TREE, 0);
16841 pop_nested_class ();
16843 else if (TREE_CODE (d) == FUNCTION_DECL)
16845 htab_t saved_local_specializations;
16850 /* Save away the current list, in case we are instantiating one
16851 template from within the body of another. */
16852 saved_local_specializations = local_specializations;
16854 /* Set up the list of local specializations. */
16855 local_specializations = htab_create (37,
16856 hash_local_specialization,
16857 eq_local_specializations,
16860 /* Set up context. */
16861 start_preparsed_function (d, NULL_TREE, SF_PRE_PARSED);
16863 /* Create substitution entries for the parameters. */
16864 subst_decl = DECL_TEMPLATE_RESULT (template_for_substitution (d));
16865 tmpl_parm = DECL_ARGUMENTS (subst_decl);
16866 spec_parm = DECL_ARGUMENTS (d);
16867 if (DECL_NONSTATIC_MEMBER_FUNCTION_P (d))
16869 register_local_specialization (spec_parm, tmpl_parm);
16870 spec_parm = skip_artificial_parms_for (d, spec_parm);
16871 tmpl_parm = skip_artificial_parms_for (subst_decl, tmpl_parm);
16873 while (tmpl_parm && !FUNCTION_PARAMETER_PACK_P (tmpl_parm))
16875 register_local_specialization (spec_parm, tmpl_parm);
16876 tmpl_parm = TREE_CHAIN (tmpl_parm);
16877 spec_parm = TREE_CHAIN (spec_parm);
16879 if (tmpl_parm && FUNCTION_PARAMETER_PACK_P (tmpl_parm))
16881 /* Register the (value) argument pack as a specialization of
16882 TMPL_PARM, then move on. */
16883 tree argpack = make_fnparm_pack (spec_parm);
16884 register_local_specialization (argpack, tmpl_parm);
16885 tmpl_parm = TREE_CHAIN (tmpl_parm);
16886 spec_parm = NULL_TREE;
16888 gcc_assert (!spec_parm);
16890 /* Substitute into the body of the function. */
16891 tsubst_expr (DECL_SAVED_TREE (code_pattern), args,
16892 tf_warning_or_error, tmpl,
16893 /*integral_constant_expression_p=*/false);
16895 /* Set the current input_location to the end of the function
16896 so that finish_function knows where we are. */
16897 input_location = DECL_STRUCT_FUNCTION (code_pattern)->function_end_locus;
16899 /* We don't need the local specializations any more. */
16900 htab_delete (local_specializations);
16901 local_specializations = saved_local_specializations;
16903 /* Finish the function. */
16904 d = finish_function (0);
16905 expand_or_defer_fn (d);
16908 /* We're not deferring instantiation any more. */
16909 TI_PENDING_TEMPLATE_FLAG (DECL_TEMPLATE_INFO (d)) = 0;
16912 pop_from_top_level ();
16915 input_location = saved_loc;
16916 pop_deferring_access_checks ();
16917 pop_tinst_level ();
16919 timevar_pop (TV_PARSE);
16924 /* Run through the list of templates that we wish we could
16925 instantiate, and instantiate any we can. RETRIES is the
16926 number of times we retry pending template instantiation. */
16929 instantiate_pending_templates (int retries)
16932 location_t saved_loc = input_location;
16934 /* Instantiating templates may trigger vtable generation. This in turn
16935 may require further template instantiations. We place a limit here
16936 to avoid infinite loop. */
16937 if (pending_templates && retries >= max_tinst_depth)
16939 tree decl = pending_templates->tinst->decl;
16941 error ("template instantiation depth exceeds maximum of %d"
16942 " instantiating %q+D, possibly from virtual table generation"
16943 " (use -ftemplate-depth= to increase the maximum)",
16944 max_tinst_depth, decl);
16945 if (TREE_CODE (decl) == FUNCTION_DECL)
16946 /* Pretend that we defined it. */
16947 DECL_INITIAL (decl) = error_mark_node;
16953 struct pending_template **t = &pending_templates;
16954 struct pending_template *last = NULL;
16958 tree instantiation = reopen_tinst_level ((*t)->tinst);
16959 bool complete = false;
16961 if (TYPE_P (instantiation))
16965 if (!COMPLETE_TYPE_P (instantiation))
16967 instantiate_class_template (instantiation);
16968 if (CLASSTYPE_TEMPLATE_INSTANTIATION (instantiation))
16969 for (fn = TYPE_METHODS (instantiation);
16971 fn = TREE_CHAIN (fn))
16972 if (! DECL_ARTIFICIAL (fn))
16973 instantiate_decl (fn,
16975 /*expl_inst_class_mem_p=*/false);
16976 if (COMPLETE_TYPE_P (instantiation))
16980 complete = COMPLETE_TYPE_P (instantiation);
16984 if (!DECL_TEMPLATE_SPECIALIZATION (instantiation)
16985 && !DECL_TEMPLATE_INSTANTIATED (instantiation))
16988 = instantiate_decl (instantiation,
16990 /*expl_inst_class_mem_p=*/false);
16991 if (DECL_TEMPLATE_INSTANTIATED (instantiation))
16995 complete = (DECL_TEMPLATE_SPECIALIZATION (instantiation)
16996 || DECL_TEMPLATE_INSTANTIATED (instantiation));
17000 /* If INSTANTIATION has been instantiated, then we don't
17001 need to consider it again in the future. */
17009 current_tinst_level = NULL;
17011 last_pending_template = last;
17013 while (reconsider);
17015 input_location = saved_loc;
17018 /* Substitute ARGVEC into T, which is a list of initializers for
17019 either base class or a non-static data member. The TREE_PURPOSEs
17020 are DECLs, and the TREE_VALUEs are the initializer values. Used by
17021 instantiate_decl. */
17024 tsubst_initializer_list (tree t, tree argvec)
17026 tree inits = NULL_TREE;
17028 for (; t; t = TREE_CHAIN (t))
17032 tree expanded_bases = NULL_TREE;
17033 tree expanded_arguments = NULL_TREE;
17036 if (TREE_CODE (TREE_PURPOSE (t)) == TYPE_PACK_EXPANSION)
17041 /* Expand the base class expansion type into separate base
17043 expanded_bases = tsubst_pack_expansion (TREE_PURPOSE (t), argvec,
17044 tf_warning_or_error,
17046 if (expanded_bases == error_mark_node)
17049 /* We'll be building separate TREE_LISTs of arguments for
17051 len = TREE_VEC_LENGTH (expanded_bases);
17052 expanded_arguments = make_tree_vec (len);
17053 for (i = 0; i < len; i++)
17054 TREE_VEC_ELT (expanded_arguments, i) = NULL_TREE;
17056 /* Build a dummy EXPR_PACK_EXPANSION that will be used to
17057 expand each argument in the TREE_VALUE of t. */
17058 expr = make_node (EXPR_PACK_EXPANSION);
17059 PACK_EXPANSION_PARAMETER_PACKS (expr) =
17060 PACK_EXPANSION_PARAMETER_PACKS (TREE_PURPOSE (t));
17062 if (TREE_VALUE (t) == void_type_node)
17063 /* VOID_TYPE_NODE is used to indicate
17064 value-initialization. */
17066 for (i = 0; i < len; i++)
17067 TREE_VEC_ELT (expanded_arguments, i) = void_type_node;
17071 /* Substitute parameter packs into each argument in the
17073 in_base_initializer = 1;
17074 for (arg = TREE_VALUE (t); arg; arg = TREE_CHAIN (arg))
17076 tree expanded_exprs;
17078 /* Expand the argument. */
17079 SET_PACK_EXPANSION_PATTERN (expr, TREE_VALUE (arg));
17081 = tsubst_pack_expansion (expr, argvec,
17082 tf_warning_or_error,
17084 if (expanded_exprs == error_mark_node)
17087 /* Prepend each of the expanded expressions to the
17088 corresponding TREE_LIST in EXPANDED_ARGUMENTS. */
17089 for (i = 0; i < len; i++)
17091 TREE_VEC_ELT (expanded_arguments, i) =
17092 tree_cons (NULL_TREE,
17093 TREE_VEC_ELT (expanded_exprs, i),
17094 TREE_VEC_ELT (expanded_arguments, i));
17097 in_base_initializer = 0;
17099 /* Reverse all of the TREE_LISTs in EXPANDED_ARGUMENTS,
17100 since we built them backwards. */
17101 for (i = 0; i < len; i++)
17103 TREE_VEC_ELT (expanded_arguments, i) =
17104 nreverse (TREE_VEC_ELT (expanded_arguments, i));
17109 for (i = 0; i < len; ++i)
17111 if (expanded_bases)
17113 decl = TREE_VEC_ELT (expanded_bases, i);
17114 decl = expand_member_init (decl);
17115 init = TREE_VEC_ELT (expanded_arguments, i);
17119 decl = tsubst_copy (TREE_PURPOSE (t), argvec,
17120 tf_warning_or_error, NULL_TREE);
17122 decl = expand_member_init (decl);
17123 if (decl && !DECL_P (decl))
17124 in_base_initializer = 1;
17126 init = tsubst_expr (TREE_VALUE (t), argvec,
17127 tf_warning_or_error, NULL_TREE,
17128 /*integral_constant_expression_p=*/false);
17129 in_base_initializer = 0;
17134 init = build_tree_list (decl, init);
17135 TREE_CHAIN (init) = inits;
17143 /* Set CURRENT_ACCESS_SPECIFIER based on the protection of DECL. */
17146 set_current_access_from_decl (tree decl)
17148 if (TREE_PRIVATE (decl))
17149 current_access_specifier = access_private_node;
17150 else if (TREE_PROTECTED (decl))
17151 current_access_specifier = access_protected_node;
17153 current_access_specifier = access_public_node;
17156 /* Instantiate an enumerated type. TAG is the template type, NEWTAG
17157 is the instantiation (which should have been created with
17158 start_enum) and ARGS are the template arguments to use. */
17161 tsubst_enum (tree tag, tree newtag, tree args)
17165 for (e = TYPE_VALUES (tag); e; e = TREE_CHAIN (e))
17170 decl = TREE_VALUE (e);
17171 /* Note that in a template enum, the TREE_VALUE is the
17172 CONST_DECL, not the corresponding INTEGER_CST. */
17173 value = tsubst_expr (DECL_INITIAL (decl),
17174 args, tf_warning_or_error, NULL_TREE,
17175 /*integral_constant_expression_p=*/true);
17177 /* Give this enumeration constant the correct access. */
17178 set_current_access_from_decl (decl);
17180 /* Actually build the enumerator itself. */
17181 build_enumerator (DECL_NAME (decl), value, newtag);
17184 finish_enum (newtag);
17185 DECL_SOURCE_LOCATION (TYPE_NAME (newtag))
17186 = DECL_SOURCE_LOCATION (TYPE_NAME (tag));
17189 /* DECL is a FUNCTION_DECL that is a template specialization. Return
17190 its type -- but without substituting the innermost set of template
17191 arguments. So, innermost set of template parameters will appear in
17195 get_mostly_instantiated_function_type (tree decl)
17203 tmpl = most_general_template (DECL_TI_TEMPLATE (decl));
17204 targs = DECL_TI_ARGS (decl);
17205 tparms = DECL_TEMPLATE_PARMS (tmpl);
17206 parm_depth = TMPL_PARMS_DEPTH (tparms);
17208 /* There should be as many levels of arguments as there are levels
17210 gcc_assert (parm_depth == TMPL_ARGS_DEPTH (targs));
17212 fn_type = TREE_TYPE (tmpl);
17214 if (parm_depth == 1)
17215 /* No substitution is necessary. */
17219 int i, save_access_control;
17222 /* Replace the innermost level of the TARGS with NULL_TREEs to
17223 let tsubst know not to substitute for those parameters. */
17224 partial_args = make_tree_vec (TREE_VEC_LENGTH (targs));
17225 for (i = 1; i < TMPL_ARGS_DEPTH (targs); ++i)
17226 SET_TMPL_ARGS_LEVEL (partial_args, i,
17227 TMPL_ARGS_LEVEL (targs, i));
17228 SET_TMPL_ARGS_LEVEL (partial_args,
17229 TMPL_ARGS_DEPTH (targs),
17230 make_tree_vec (DECL_NTPARMS (tmpl)));
17232 /* Disable access control as this function is used only during
17234 save_access_control = flag_access_control;
17235 flag_access_control = 0;
17237 ++processing_template_decl;
17238 /* Now, do the (partial) substitution to figure out the
17239 appropriate function type. */
17240 fn_type = tsubst (fn_type, partial_args, tf_error, NULL_TREE);
17241 --processing_template_decl;
17243 /* Substitute into the template parameters to obtain the real
17244 innermost set of parameters. This step is important if the
17245 innermost set of template parameters contains value
17246 parameters whose types depend on outer template parameters. */
17247 TREE_VEC_LENGTH (partial_args)--;
17248 tparms = tsubst_template_parms (tparms, partial_args, tf_error);
17250 flag_access_control = save_access_control;
17256 /* Return truthvalue if we're processing a template different from
17257 the last one involved in diagnostics. */
17259 problematic_instantiation_changed (void)
17261 return last_template_error_tick != tinst_level_tick;
17264 /* Remember current template involved in diagnostics. */
17266 record_last_problematic_instantiation (void)
17268 last_template_error_tick = tinst_level_tick;
17271 struct tinst_level *
17272 current_instantiation (void)
17274 return current_tinst_level;
17277 /* [temp.param] Check that template non-type parm TYPE is of an allowable
17278 type. Return zero for ok, nonzero for disallowed. Issue error and
17279 warning messages under control of COMPLAIN. */
17282 invalid_nontype_parm_type_p (tree type, tsubst_flags_t complain)
17284 if (INTEGRAL_OR_ENUMERATION_TYPE_P (type))
17286 else if (POINTER_TYPE_P (type))
17288 else if (TYPE_PTR_TO_MEMBER_P (type))
17290 else if (TREE_CODE (type) == TEMPLATE_TYPE_PARM)
17292 else if (TREE_CODE (type) == TYPENAME_TYPE)
17295 if (complain & tf_error)
17296 error ("%q#T is not a valid type for a template constant parameter", type);
17300 /* Returns TRUE if TYPE is dependent, in the sense of [temp.dep.type].
17301 Assumes that TYPE really is a type, and not the ERROR_MARK_NODE.*/
17304 dependent_type_p_r (tree type)
17310 A type is dependent if it is:
17312 -- a template parameter. Template template parameters are types
17313 for us (since TYPE_P holds true for them) so we handle
17315 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
17316 || TREE_CODE (type) == TEMPLATE_TEMPLATE_PARM)
17318 /* -- a qualified-id with a nested-name-specifier which contains a
17319 class-name that names a dependent type or whose unqualified-id
17320 names a dependent type. */
17321 if (TREE_CODE (type) == TYPENAME_TYPE)
17323 /* -- a cv-qualified type where the cv-unqualified type is
17325 type = TYPE_MAIN_VARIANT (type);
17326 /* -- a compound type constructed from any dependent type. */
17327 if (TYPE_PTR_TO_MEMBER_P (type))
17328 return (dependent_type_p (TYPE_PTRMEM_CLASS_TYPE (type))
17329 || dependent_type_p (TYPE_PTRMEM_POINTED_TO_TYPE
17331 else if (TREE_CODE (type) == POINTER_TYPE
17332 || TREE_CODE (type) == REFERENCE_TYPE)
17333 return dependent_type_p (TREE_TYPE (type));
17334 else if (TREE_CODE (type) == FUNCTION_TYPE
17335 || TREE_CODE (type) == METHOD_TYPE)
17339 if (dependent_type_p (TREE_TYPE (type)))
17341 for (arg_type = TYPE_ARG_TYPES (type);
17343 arg_type = TREE_CHAIN (arg_type))
17344 if (dependent_type_p (TREE_VALUE (arg_type)))
17348 /* -- an array type constructed from any dependent type or whose
17349 size is specified by a constant expression that is
17350 value-dependent. */
17351 if (TREE_CODE (type) == ARRAY_TYPE)
17353 if (TYPE_DOMAIN (type)
17354 && dependent_type_p (TYPE_DOMAIN (type)))
17356 return dependent_type_p (TREE_TYPE (type));
17358 else if (TREE_CODE (type) == INTEGER_TYPE
17359 && !TREE_CONSTANT (TYPE_MAX_VALUE (type)))
17361 /* If this is the TYPE_DOMAIN of an array type, consider it
17362 dependent. We already checked for value-dependence in
17363 compute_array_index_type. */
17364 return type_dependent_expression_p (TYPE_MAX_VALUE (type));
17367 /* -- a template-id in which either the template name is a template
17369 if (TREE_CODE (type) == BOUND_TEMPLATE_TEMPLATE_PARM)
17371 /* ... or any of the template arguments is a dependent type or
17372 an expression that is type-dependent or value-dependent. */
17373 else if (CLASS_TYPE_P (type) && CLASSTYPE_TEMPLATE_INFO (type)
17374 && (any_dependent_template_arguments_p
17375 (INNERMOST_TEMPLATE_ARGS (CLASSTYPE_TI_ARGS (type)))))
17378 /* All TYPEOF_TYPEs and DECLTYPE_TYPEs are dependent; if the
17379 argument of the `typeof' expression is not type-dependent, then
17380 it should already been have resolved. */
17381 if (TREE_CODE (type) == TYPEOF_TYPE
17382 || TREE_CODE (type) == DECLTYPE_TYPE)
17385 /* A template argument pack is dependent if any of its packed
17387 if (TREE_CODE (type) == TYPE_ARGUMENT_PACK)
17389 tree args = ARGUMENT_PACK_ARGS (type);
17390 int i, len = TREE_VEC_LENGTH (args);
17391 for (i = 0; i < len; ++i)
17392 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
17396 /* All TYPE_PACK_EXPANSIONs are dependent, because parameter packs must
17397 be template parameters. */
17398 if (TREE_CODE (type) == TYPE_PACK_EXPANSION)
17401 /* The standard does not specifically mention types that are local
17402 to template functions or local classes, but they should be
17403 considered dependent too. For example:
17405 template <int I> void f() {
17410 The size of `E' cannot be known until the value of `I' has been
17411 determined. Therefore, `E' must be considered dependent. */
17412 scope = TYPE_CONTEXT (type);
17413 if (scope && TYPE_P (scope))
17414 return dependent_type_p (scope);
17415 else if (scope && TREE_CODE (scope) == FUNCTION_DECL)
17416 return type_dependent_expression_p (scope);
17418 /* Other types are non-dependent. */
17422 /* Returns TRUE if TYPE is dependent, in the sense of
17423 [temp.dep.type]. */
17426 dependent_type_p (tree type)
17428 /* If there are no template parameters in scope, then there can't be
17429 any dependent types. */
17430 if (!processing_template_decl)
17432 /* If we are not processing a template, then nobody should be
17433 providing us with a dependent type. */
17435 gcc_assert (TREE_CODE (type) != TEMPLATE_TYPE_PARM || is_auto (type));
17439 /* If the type is NULL, we have not computed a type for the entity
17440 in question; in that case, the type is dependent. */
17444 /* Erroneous types can be considered non-dependent. */
17445 if (type == error_mark_node)
17448 /* If we have not already computed the appropriate value for TYPE,
17450 if (!TYPE_DEPENDENT_P_VALID (type))
17452 TYPE_DEPENDENT_P (type) = dependent_type_p_r (type);
17453 TYPE_DEPENDENT_P_VALID (type) = 1;
17456 return TYPE_DEPENDENT_P (type);
17459 /* Returns TRUE if SCOPE is a dependent scope, in which we can't do any
17460 lookup. In other words, a dependent type that is not the current
17464 dependent_scope_p (tree scope)
17466 return (scope && TYPE_P (scope) && dependent_type_p (scope)
17467 && !currently_open_class (scope));
17470 /* Returns TRUE if EXPRESSION is dependent, according to CRITERION. */
17473 dependent_scope_ref_p (tree expression, bool criterion (tree))
17478 gcc_assert (TREE_CODE (expression) == SCOPE_REF);
17480 if (!TYPE_P (TREE_OPERAND (expression, 0)))
17483 scope = TREE_OPERAND (expression, 0);
17484 name = TREE_OPERAND (expression, 1);
17488 An id-expression is type-dependent if it contains a
17489 nested-name-specifier that contains a class-name that names a
17491 /* The suggested resolution to Core Issue 224 implies that if the
17492 qualifying type is the current class, then we must peek
17495 && currently_open_class (scope)
17496 && !criterion (name))
17498 if (dependent_type_p (scope))
17504 /* Returns TRUE if the EXPRESSION is value-dependent, in the sense of
17505 [temp.dep.constexpr]. EXPRESSION is already known to be a constant
17509 value_dependent_expression_p (tree expression)
17511 if (!processing_template_decl)
17514 /* A name declared with a dependent type. */
17515 if (DECL_P (expression) && type_dependent_expression_p (expression))
17518 switch (TREE_CODE (expression))
17520 case IDENTIFIER_NODE:
17521 /* A name that has not been looked up -- must be dependent. */
17524 case TEMPLATE_PARM_INDEX:
17525 /* A non-type template parm. */
17529 /* A non-type template parm. */
17530 if (DECL_TEMPLATE_PARM_P (expression))
17532 return value_dependent_expression_p (DECL_INITIAL (expression));
17535 /* A constant with integral or enumeration type and is initialized
17536 with an expression that is value-dependent. */
17537 if (DECL_INITIAL (expression)
17538 && INTEGRAL_OR_ENUMERATION_TYPE_P (TREE_TYPE (expression))
17539 && value_dependent_expression_p (DECL_INITIAL (expression)))
17543 case DYNAMIC_CAST_EXPR:
17544 case STATIC_CAST_EXPR:
17545 case CONST_CAST_EXPR:
17546 case REINTERPRET_CAST_EXPR:
17548 /* These expressions are value-dependent if the type to which
17549 the cast occurs is dependent or the expression being casted
17550 is value-dependent. */
17552 tree type = TREE_TYPE (expression);
17554 if (dependent_type_p (type))
17557 /* A functional cast has a list of operands. */
17558 expression = TREE_OPERAND (expression, 0);
17561 /* If there are no operands, it must be an expression such
17562 as "int()". This should not happen for aggregate types
17563 because it would form non-constant expressions. */
17564 gcc_assert (INTEGRAL_OR_ENUMERATION_TYPE_P (type));
17569 if (TREE_CODE (expression) == TREE_LIST)
17570 return any_value_dependent_elements_p (expression);
17572 return value_dependent_expression_p (expression);
17577 /* A `sizeof' expression is value-dependent if the operand is
17578 type-dependent or is a pack expansion. */
17579 expression = TREE_OPERAND (expression, 0);
17580 if (PACK_EXPANSION_P (expression))
17582 else if (TYPE_P (expression))
17583 return dependent_type_p (expression);
17584 return type_dependent_expression_p (expression);
17587 return dependent_scope_ref_p (expression, value_dependent_expression_p);
17589 case COMPONENT_REF:
17590 return (value_dependent_expression_p (TREE_OPERAND (expression, 0))
17591 || value_dependent_expression_p (TREE_OPERAND (expression, 1)));
17594 /* A CALL_EXPR may appear in a constant expression if it is a
17595 call to a builtin function, e.g., __builtin_constant_p. All
17596 such calls are value-dependent. */
17599 case NONTYPE_ARGUMENT_PACK:
17600 /* A NONTYPE_ARGUMENT_PACK is value-dependent if any packed argument
17601 is value-dependent. */
17603 tree values = ARGUMENT_PACK_ARGS (expression);
17604 int i, len = TREE_VEC_LENGTH (values);
17606 for (i = 0; i < len; ++i)
17607 if (value_dependent_expression_p (TREE_VEC_ELT (values, i)))
17615 tree type2 = TRAIT_EXPR_TYPE2 (expression);
17616 return (dependent_type_p (TRAIT_EXPR_TYPE1 (expression))
17617 || (type2 ? dependent_type_p (type2) : false));
17621 return ((value_dependent_expression_p (TREE_OPERAND (expression, 0)))
17622 || (value_dependent_expression_p (TREE_OPERAND (expression, 2))));
17625 /* A constant expression is value-dependent if any subexpression is
17626 value-dependent. */
17627 switch (TREE_CODE_CLASS (TREE_CODE (expression)))
17629 case tcc_reference:
17631 return (value_dependent_expression_p
17632 (TREE_OPERAND (expression, 0)));
17634 case tcc_comparison:
17636 return ((value_dependent_expression_p
17637 (TREE_OPERAND (expression, 0)))
17638 || (value_dependent_expression_p
17639 (TREE_OPERAND (expression, 1))));
17641 case tcc_expression:
17645 for (i = 0; i < TREE_OPERAND_LENGTH (expression); ++i)
17646 /* In some cases, some of the operands may be missing.
17647 (For example, in the case of PREDECREMENT_EXPR, the
17648 amount to increment by may be missing.) That doesn't
17649 make the expression dependent. */
17650 if (TREE_OPERAND (expression, i)
17651 && (value_dependent_expression_p
17652 (TREE_OPERAND (expression, i))))
17662 /* The expression is not value-dependent. */
17666 /* Returns TRUE if the EXPRESSION is type-dependent, in the sense of
17667 [temp.dep.expr]. */
17670 type_dependent_expression_p (tree expression)
17672 if (!processing_template_decl)
17675 if (expression == error_mark_node)
17678 /* An unresolved name is always dependent. */
17679 if (TREE_CODE (expression) == IDENTIFIER_NODE
17680 || TREE_CODE (expression) == USING_DECL)
17683 /* Some expression forms are never type-dependent. */
17684 if (TREE_CODE (expression) == PSEUDO_DTOR_EXPR
17685 || TREE_CODE (expression) == SIZEOF_EXPR
17686 || TREE_CODE (expression) == ALIGNOF_EXPR
17687 || TREE_CODE (expression) == TRAIT_EXPR
17688 || TREE_CODE (expression) == TYPEID_EXPR
17689 || TREE_CODE (expression) == DELETE_EXPR
17690 || TREE_CODE (expression) == VEC_DELETE_EXPR
17691 || TREE_CODE (expression) == THROW_EXPR)
17694 /* The types of these expressions depends only on the type to which
17695 the cast occurs. */
17696 if (TREE_CODE (expression) == DYNAMIC_CAST_EXPR
17697 || TREE_CODE (expression) == STATIC_CAST_EXPR
17698 || TREE_CODE (expression) == CONST_CAST_EXPR
17699 || TREE_CODE (expression) == REINTERPRET_CAST_EXPR
17700 || TREE_CODE (expression) == CAST_EXPR)
17701 return dependent_type_p (TREE_TYPE (expression));
17703 /* The types of these expressions depends only on the type created
17704 by the expression. */
17705 if (TREE_CODE (expression) == NEW_EXPR
17706 || TREE_CODE (expression) == VEC_NEW_EXPR)
17708 /* For NEW_EXPR tree nodes created inside a template, either
17709 the object type itself or a TREE_LIST may appear as the
17711 tree type = TREE_OPERAND (expression, 1);
17712 if (TREE_CODE (type) == TREE_LIST)
17713 /* This is an array type. We need to check array dimensions
17715 return dependent_type_p (TREE_VALUE (TREE_PURPOSE (type)))
17716 || value_dependent_expression_p
17717 (TREE_OPERAND (TREE_VALUE (type), 1));
17719 return dependent_type_p (type);
17722 if (TREE_CODE (expression) == SCOPE_REF
17723 && dependent_scope_ref_p (expression,
17724 type_dependent_expression_p))
17727 if (TREE_CODE (expression) == FUNCTION_DECL
17728 && DECL_LANG_SPECIFIC (expression)
17729 && DECL_TEMPLATE_INFO (expression)
17730 && (any_dependent_template_arguments_p
17731 (INNERMOST_TEMPLATE_ARGS (DECL_TI_ARGS (expression)))))
17734 if (TREE_CODE (expression) == TEMPLATE_DECL
17735 && !DECL_TEMPLATE_TEMPLATE_PARM_P (expression))
17738 if (TREE_CODE (expression) == STMT_EXPR)
17739 expression = stmt_expr_value_expr (expression);
17741 if (BRACE_ENCLOSED_INITIALIZER_P (expression))
17746 FOR_EACH_CONSTRUCTOR_VALUE (CONSTRUCTOR_ELTS (expression), i, elt)
17748 if (type_dependent_expression_p (elt))
17754 /* A static data member of the current instantiation with incomplete
17755 array type is type-dependent, as the definition and specializations
17756 can have different bounds. */
17757 if (TREE_CODE (expression) == VAR_DECL
17758 && DECL_CLASS_SCOPE_P (expression)
17759 && dependent_type_p (DECL_CONTEXT (expression))
17760 && VAR_HAD_UNKNOWN_BOUND (expression))
17763 if (TREE_TYPE (expression) == unknown_type_node)
17765 if (TREE_CODE (expression) == ADDR_EXPR)
17766 return type_dependent_expression_p (TREE_OPERAND (expression, 0));
17767 if (TREE_CODE (expression) == COMPONENT_REF
17768 || TREE_CODE (expression) == OFFSET_REF)
17770 if (type_dependent_expression_p (TREE_OPERAND (expression, 0)))
17772 expression = TREE_OPERAND (expression, 1);
17773 if (TREE_CODE (expression) == IDENTIFIER_NODE)
17776 /* SCOPE_REF with non-null TREE_TYPE is always non-dependent. */
17777 if (TREE_CODE (expression) == SCOPE_REF)
17780 if (TREE_CODE (expression) == BASELINK)
17781 expression = BASELINK_FUNCTIONS (expression);
17783 if (TREE_CODE (expression) == TEMPLATE_ID_EXPR)
17785 if (any_dependent_template_arguments_p
17786 (TREE_OPERAND (expression, 1)))
17788 expression = TREE_OPERAND (expression, 0);
17790 gcc_assert (TREE_CODE (expression) == OVERLOAD
17791 || TREE_CODE (expression) == FUNCTION_DECL);
17795 if (type_dependent_expression_p (OVL_CURRENT (expression)))
17797 expression = OVL_NEXT (expression);
17802 gcc_assert (TREE_CODE (expression) != TYPE_DECL);
17804 return (dependent_type_p (TREE_TYPE (expression)));
17807 /* Like type_dependent_expression_p, but it also works while not processing
17808 a template definition, i.e. during substitution or mangling. */
17811 type_dependent_expression_p_push (tree expr)
17814 ++processing_template_decl;
17815 b = type_dependent_expression_p (expr);
17816 --processing_template_decl;
17820 /* Returns TRUE if ARGS contains a type-dependent expression. */
17823 any_type_dependent_arguments_p (const VEC(tree,gc) *args)
17828 for (i = 0; VEC_iterate (tree, args, i, arg); ++i)
17830 if (type_dependent_expression_p (arg))
17836 /* Returns TRUE if LIST (a TREE_LIST whose TREE_VALUEs are
17837 expressions) contains any value-dependent expressions. */
17840 any_value_dependent_elements_p (const_tree list)
17842 for (; list; list = TREE_CHAIN (list))
17843 if (value_dependent_expression_p (TREE_VALUE (list)))
17849 /* Returns TRUE if the ARG (a template argument) is dependent. */
17852 dependent_template_arg_p (tree arg)
17854 if (!processing_template_decl)
17857 if (TREE_CODE (arg) == TEMPLATE_DECL
17858 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
17859 return dependent_template_p (arg);
17860 else if (ARGUMENT_PACK_P (arg))
17862 tree args = ARGUMENT_PACK_ARGS (arg);
17863 int i, len = TREE_VEC_LENGTH (args);
17864 for (i = 0; i < len; ++i)
17866 if (dependent_template_arg_p (TREE_VEC_ELT (args, i)))
17872 else if (TYPE_P (arg))
17873 return dependent_type_p (arg);
17875 return (type_dependent_expression_p (arg)
17876 || value_dependent_expression_p (arg));
17879 /* Returns true if ARGS (a collection of template arguments) contains
17880 any types that require structural equality testing. */
17883 any_template_arguments_need_structural_equality_p (tree args)
17890 if (args == error_mark_node)
17893 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
17895 tree level = TMPL_ARGS_LEVEL (args, i + 1);
17896 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
17898 tree arg = TREE_VEC_ELT (level, j);
17899 tree packed_args = NULL_TREE;
17902 if (ARGUMENT_PACK_P (arg))
17904 /* Look inside the argument pack. */
17905 packed_args = ARGUMENT_PACK_ARGS (arg);
17906 len = TREE_VEC_LENGTH (packed_args);
17909 for (k = 0; k < len; ++k)
17912 arg = TREE_VEC_ELT (packed_args, k);
17914 if (error_operand_p (arg))
17916 else if (TREE_CODE (arg) == TEMPLATE_DECL
17917 || TREE_CODE (arg) == TEMPLATE_TEMPLATE_PARM)
17919 else if (TYPE_P (arg) && TYPE_STRUCTURAL_EQUALITY_P (arg))
17921 else if (!TYPE_P (arg) && TREE_TYPE (arg)
17922 && TYPE_STRUCTURAL_EQUALITY_P (TREE_TYPE (arg)))
17931 /* Returns true if ARGS (a collection of template arguments) contains
17932 any dependent arguments. */
17935 any_dependent_template_arguments_p (const_tree args)
17942 if (args == error_mark_node)
17945 for (i = 0; i < TMPL_ARGS_DEPTH (args); ++i)
17947 const_tree level = TMPL_ARGS_LEVEL (args, i + 1);
17948 for (j = 0; j < TREE_VEC_LENGTH (level); ++j)
17949 if (dependent_template_arg_p (TREE_VEC_ELT (level, j)))
17956 /* Returns TRUE if the template TMPL is dependent. */
17959 dependent_template_p (tree tmpl)
17961 if (TREE_CODE (tmpl) == OVERLOAD)
17965 if (dependent_template_p (OVL_FUNCTION (tmpl)))
17967 tmpl = OVL_CHAIN (tmpl);
17972 /* Template template parameters are dependent. */
17973 if (DECL_TEMPLATE_TEMPLATE_PARM_P (tmpl)
17974 || TREE_CODE (tmpl) == TEMPLATE_TEMPLATE_PARM)
17976 /* So are names that have not been looked up. */
17977 if (TREE_CODE (tmpl) == SCOPE_REF
17978 || TREE_CODE (tmpl) == IDENTIFIER_NODE)
17980 /* So are member templates of dependent classes. */
17981 if (TYPE_P (CP_DECL_CONTEXT (tmpl)))
17982 return dependent_type_p (DECL_CONTEXT (tmpl));
17986 /* Returns TRUE if the specialization TMPL<ARGS> is dependent. */
17989 dependent_template_id_p (tree tmpl, tree args)
17991 return (dependent_template_p (tmpl)
17992 || any_dependent_template_arguments_p (args));
17995 /* Returns TRUE if OMP_FOR with DECLV, INITV, CONDV and INCRV vectors
17999 dependent_omp_for_p (tree declv, tree initv, tree condv, tree incrv)
18003 if (!processing_template_decl)
18006 for (i = 0; i < TREE_VEC_LENGTH (declv); i++)
18008 tree decl = TREE_VEC_ELT (declv, i);
18009 tree init = TREE_VEC_ELT (initv, i);
18010 tree cond = TREE_VEC_ELT (condv, i);
18011 tree incr = TREE_VEC_ELT (incrv, i);
18013 if (type_dependent_expression_p (decl))
18016 if (init && type_dependent_expression_p (init))
18019 if (type_dependent_expression_p (cond))
18022 if (COMPARISON_CLASS_P (cond)
18023 && (type_dependent_expression_p (TREE_OPERAND (cond, 0))
18024 || type_dependent_expression_p (TREE_OPERAND (cond, 1))))
18027 if (TREE_CODE (incr) == MODOP_EXPR)
18029 if (type_dependent_expression_p (TREE_OPERAND (incr, 0))
18030 || type_dependent_expression_p (TREE_OPERAND (incr, 2)))
18033 else if (type_dependent_expression_p (incr))
18035 else if (TREE_CODE (incr) == MODIFY_EXPR)
18037 if (type_dependent_expression_p (TREE_OPERAND (incr, 0)))
18039 else if (BINARY_CLASS_P (TREE_OPERAND (incr, 1)))
18041 tree t = TREE_OPERAND (incr, 1);
18042 if (type_dependent_expression_p (TREE_OPERAND (t, 0))
18043 || type_dependent_expression_p (TREE_OPERAND (t, 1)))
18052 /* TYPE is a TYPENAME_TYPE. Returns the ordinary TYPE to which the
18053 TYPENAME_TYPE corresponds. Returns the original TYPENAME_TYPE if
18054 no such TYPE can be found. Note that this function peers inside
18055 uninstantiated templates and therefore should be used only in
18056 extremely limited situations. ONLY_CURRENT_P restricts this
18057 peering to the currently open classes hierarchy (which is required
18058 when comparing types). */
18061 resolve_typename_type (tree type, bool only_current_p)
18070 gcc_assert (TREE_CODE (type) == TYPENAME_TYPE);
18072 scope = TYPE_CONTEXT (type);
18073 /* Usually the non-qualified identifier of a TYPENAME_TYPE is
18074 TYPE_IDENTIFIER (type). But when 'type' is a typedef variant of
18075 a TYPENAME_TYPE node, then TYPE_NAME (type) is set to the TYPE_DECL representing
18076 the typedef. In that case TYPE_IDENTIFIER (type) is not the non-qualified
18077 identifier of the TYPENAME_TYPE anymore.
18078 So by getting the TYPE_IDENTIFIER of the _main declaration_ of the
18079 TYPENAME_TYPE instead, we avoid messing up with a possible
18080 typedef variant case. */
18081 name = TYPE_IDENTIFIER (TYPE_MAIN_VARIANT (type));
18083 /* If the SCOPE is itself a TYPENAME_TYPE, then we need to resolve
18084 it first before we can figure out what NAME refers to. */
18085 if (TREE_CODE (scope) == TYPENAME_TYPE)
18086 scope = resolve_typename_type (scope, only_current_p);
18087 /* If we don't know what SCOPE refers to, then we cannot resolve the
18089 if (TREE_CODE (scope) == TYPENAME_TYPE)
18091 /* If the SCOPE is a template type parameter, we have no way of
18092 resolving the name. */
18093 if (TREE_CODE (scope) == TEMPLATE_TYPE_PARM)
18095 /* If the SCOPE is not the current instantiation, there's no reason
18096 to look inside it. */
18097 if (only_current_p && !currently_open_class (scope))
18099 /* If this is a typedef, we don't want to look inside (c++/11987). */
18100 if (typedef_variant_p (type))
18102 /* If SCOPE isn't the template itself, it will not have a valid
18103 TYPE_FIELDS list. */
18104 if (same_type_p (scope, CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope)))
18105 /* scope is either the template itself or a compatible instantiation
18106 like X<T>, so look up the name in the original template. */
18107 scope = CLASSTYPE_PRIMARY_TEMPLATE_TYPE (scope);
18109 /* scope is a partial instantiation, so we can't do the lookup or we
18110 will lose the template arguments. */
18112 /* Enter the SCOPE so that name lookup will be resolved as if we
18113 were in the class definition. In particular, SCOPE will no
18114 longer be considered a dependent type. */
18115 pushed_scope = push_scope (scope);
18116 /* Look up the declaration. */
18117 decl = lookup_member (scope, name, /*protect=*/0, /*want_type=*/true);
18119 result = NULL_TREE;
18121 /* For a TYPENAME_TYPE like "typename X::template Y<T>", we want to
18122 find a TEMPLATE_DECL. Otherwise, we want to find a TYPE_DECL. */
18125 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == IDENTIFIER_NODE
18126 && TREE_CODE (decl) == TYPE_DECL)
18128 result = TREE_TYPE (decl);
18129 if (result == error_mark_node)
18130 result = NULL_TREE;
18132 else if (TREE_CODE (TYPENAME_TYPE_FULLNAME (type)) == TEMPLATE_ID_EXPR
18133 && DECL_CLASS_TEMPLATE_P (decl))
18137 /* Obtain the template and the arguments. */
18138 tmpl = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 0);
18139 args = TREE_OPERAND (TYPENAME_TYPE_FULLNAME (type), 1);
18140 /* Instantiate the template. */
18141 result = lookup_template_class (tmpl, args, NULL_TREE, NULL_TREE,
18142 /*entering_scope=*/0,
18143 tf_error | tf_user);
18144 if (result == error_mark_node)
18145 result = NULL_TREE;
18148 /* Leave the SCOPE. */
18150 pop_scope (pushed_scope);
18152 /* If we failed to resolve it, return the original typename. */
18156 /* If lookup found a typename type, resolve that too. */
18157 if (TREE_CODE (result) == TYPENAME_TYPE && !TYPENAME_IS_RESOLVING_P (result))
18159 /* Ill-formed programs can cause infinite recursion here, so we
18160 must catch that. */
18161 TYPENAME_IS_RESOLVING_P (type) = 1;
18162 result = resolve_typename_type (result, only_current_p);
18163 TYPENAME_IS_RESOLVING_P (type) = 0;
18166 /* Qualify the resulting type. */
18167 quals = cp_type_quals (type);
18169 result = cp_build_qualified_type (result, cp_type_quals (result) | quals);
18174 /* EXPR is an expression which is not type-dependent. Return a proxy
18175 for EXPR that can be used to compute the types of larger
18176 expressions containing EXPR. */
18179 build_non_dependent_expr (tree expr)
18183 /* Preserve null pointer constants so that the type of things like
18184 "p == 0" where "p" is a pointer can be determined. */
18185 if (null_ptr_cst_p (expr))
18187 /* Preserve OVERLOADs; the functions must be available to resolve
18190 if (TREE_CODE (inner_expr) == STMT_EXPR)
18191 inner_expr = stmt_expr_value_expr (inner_expr);
18192 if (TREE_CODE (inner_expr) == ADDR_EXPR)
18193 inner_expr = TREE_OPERAND (inner_expr, 0);
18194 if (TREE_CODE (inner_expr) == COMPONENT_REF)
18195 inner_expr = TREE_OPERAND (inner_expr, 1);
18196 if (is_overloaded_fn (inner_expr)
18197 || TREE_CODE (inner_expr) == OFFSET_REF)
18199 /* There is no need to return a proxy for a variable. */
18200 if (TREE_CODE (expr) == VAR_DECL)
18202 /* Preserve string constants; conversions from string constants to
18203 "char *" are allowed, even though normally a "const char *"
18204 cannot be used to initialize a "char *". */
18205 if (TREE_CODE (expr) == STRING_CST)
18207 /* Preserve arithmetic constants, as an optimization -- there is no
18208 reason to create a new node. */
18209 if (TREE_CODE (expr) == INTEGER_CST || TREE_CODE (expr) == REAL_CST)
18211 /* Preserve THROW_EXPRs -- all throw-expressions have type "void".
18212 There is at least one place where we want to know that a
18213 particular expression is a throw-expression: when checking a ?:
18214 expression, there are special rules if the second or third
18215 argument is a throw-expression. */
18216 if (TREE_CODE (expr) == THROW_EXPR)
18219 if (TREE_CODE (expr) == COND_EXPR)
18220 return build3 (COND_EXPR,
18222 TREE_OPERAND (expr, 0),
18223 (TREE_OPERAND (expr, 1)
18224 ? build_non_dependent_expr (TREE_OPERAND (expr, 1))
18225 : build_non_dependent_expr (TREE_OPERAND (expr, 0))),
18226 build_non_dependent_expr (TREE_OPERAND (expr, 2)));
18227 if (TREE_CODE (expr) == COMPOUND_EXPR
18228 && !COMPOUND_EXPR_OVERLOADED (expr))
18229 return build2 (COMPOUND_EXPR,
18231 TREE_OPERAND (expr, 0),
18232 build_non_dependent_expr (TREE_OPERAND (expr, 1)));
18234 /* If the type is unknown, it can't really be non-dependent */
18235 gcc_assert (TREE_TYPE (expr) != unknown_type_node);
18237 /* Otherwise, build a NON_DEPENDENT_EXPR.
18239 REFERENCE_TYPEs are not stripped for expressions in templates
18240 because doing so would play havoc with mangling. Consider, for
18243 template <typename T> void f<T& g>() { g(); }
18245 In the body of "f", the expression for "g" will have
18246 REFERENCE_TYPE, even though the standard says that it should
18247 not. The reason is that we must preserve the syntactic form of
18248 the expression so that mangling (say) "f<g>" inside the body of
18249 "f" works out correctly. Therefore, the REFERENCE_TYPE is
18251 return build1 (NON_DEPENDENT_EXPR, non_reference (TREE_TYPE (expr)), expr);
18254 /* ARGS is a vector of expressions as arguments to a function call.
18255 Replace the arguments with equivalent non-dependent expressions.
18256 This modifies ARGS in place. */
18259 make_args_non_dependent (VEC(tree,gc) *args)
18264 for (ix = 0; VEC_iterate (tree, args, ix, arg); ++ix)
18266 tree newarg = build_non_dependent_expr (arg);
18268 VEC_replace (tree, args, ix, newarg);
18272 /* Returns a type which represents 'auto'. We use a TEMPLATE_TYPE_PARM
18273 with a level one deeper than the actual template parms. */
18278 tree au = cxx_make_type (TEMPLATE_TYPE_PARM);
18279 TYPE_NAME (au) = build_decl (BUILTINS_LOCATION,
18280 TYPE_DECL, get_identifier ("auto"), au);
18281 TYPE_STUB_DECL (au) = TYPE_NAME (au);
18282 TEMPLATE_TYPE_PARM_INDEX (au) = build_template_parm_index
18283 (0, processing_template_decl + 1, processing_template_decl + 1,
18284 TYPE_NAME (au), NULL_TREE);
18285 TYPE_CANONICAL (au) = canonical_type_parameter (au);
18286 DECL_ARTIFICIAL (TYPE_NAME (au)) = 1;
18287 SET_DECL_TEMPLATE_PARM_P (TYPE_NAME (au));
18292 /* Given type ARG, return std::initializer_list<ARG>. */
18297 tree std_init_list = namespace_binding
18298 (get_identifier ("initializer_list"), std_node);
18300 if (!std_init_list || !DECL_CLASS_TEMPLATE_P (std_init_list))
18302 error ("deducing from brace-enclosed initializer list requires "
18303 "#include <initializer_list>");
18304 return error_mark_node;
18306 argvec = make_tree_vec (1);
18307 TREE_VEC_ELT (argvec, 0) = arg;
18308 return lookup_template_class (std_init_list, argvec, NULL_TREE,
18309 NULL_TREE, 0, tf_warning_or_error);
18312 /* Replace auto in TYPE with std::initializer_list<auto>. */
18315 listify_autos (tree type, tree auto_node)
18317 tree init_auto = listify (auto_node);
18318 tree argvec = make_tree_vec (1);
18319 TREE_VEC_ELT (argvec, 0) = init_auto;
18320 if (processing_template_decl)
18321 argvec = add_to_template_args (current_template_args (), argvec);
18322 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
18325 /* walk_tree helper for do_auto_deduction. */
18328 contains_auto_r (tree *tp, int *walk_subtrees ATTRIBUTE_UNUSED,
18331 /* Is this a variable with the type we're looking for? */
18333 && TREE_TYPE (*tp) == type)
18339 /* Replace occurrences of 'auto' in TYPE with the appropriate type deduced
18340 from INIT. AUTO_NODE is the TEMPLATE_TYPE_PARM used for 'auto' in TYPE. */
18343 do_auto_deduction (tree type, tree init, tree auto_node)
18345 tree parms, tparms, targs;
18350 /* The name of the object being declared shall not appear in the
18351 initializer expression. */
18352 decl = cp_walk_tree_without_duplicates (&init, contains_auto_r, type);
18355 error ("variable %q#D with %<auto%> type used in its own "
18356 "initializer", decl);
18357 return error_mark_node;
18360 /* [dcl.spec.auto]: Obtain P from T by replacing the occurrences of auto
18361 with either a new invented type template parameter U or, if the
18362 initializer is a braced-init-list (8.5.4), with
18363 std::initializer_list<U>. */
18364 if (BRACE_ENCLOSED_INITIALIZER_P (init))
18365 type = listify_autos (type, auto_node);
18367 parms = build_tree_list (NULL_TREE, type);
18369 tparms = make_tree_vec (1);
18370 targs = make_tree_vec (1);
18371 TREE_VEC_ELT (tparms, 0)
18372 = build_tree_list (NULL_TREE, TYPE_NAME (auto_node));
18373 val = type_unification_real (tparms, targs, parms, args, 1, 0,
18374 DEDUCE_CALL, LOOKUP_NORMAL);
18377 error ("unable to deduce %qT from %qE", type, init);
18378 return error_mark_node;
18381 /* If the list of declarators contains more than one declarator, the type
18382 of each declared variable is determined as described above. If the
18383 type deduced for the template parameter U is not the same in each
18384 deduction, the program is ill-formed. */
18385 if (TREE_TYPE (auto_node)
18386 && !same_type_p (TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0)))
18388 error ("inconsistent deduction for %qT: %qT and then %qT",
18389 auto_node, TREE_TYPE (auto_node), TREE_VEC_ELT (targs, 0));
18390 return error_mark_node;
18392 TREE_TYPE (auto_node) = TREE_VEC_ELT (targs, 0);
18394 if (processing_template_decl)
18395 targs = add_to_template_args (current_template_args (), targs);
18396 return tsubst (type, targs, tf_warning_or_error, NULL_TREE);
18399 /* Substitutes LATE_RETURN_TYPE for 'auto' in TYPE and returns the
18403 splice_late_return_type (tree type, tree late_return_type)
18407 if (late_return_type == NULL_TREE)
18409 argvec = make_tree_vec (1);
18410 TREE_VEC_ELT (argvec, 0) = late_return_type;
18411 if (processing_template_decl)
18412 argvec = add_to_template_args (current_template_args (), argvec);
18413 return tsubst (type, argvec, tf_warning_or_error, NULL_TREE);
18416 /* Returns true iff TYPE is a TEMPLATE_TYPE_PARM representing 'auto'. */
18419 is_auto (const_tree type)
18421 if (TREE_CODE (type) == TEMPLATE_TYPE_PARM
18422 && TYPE_IDENTIFIER (type) == get_identifier ("auto"))
18428 /* Returns true iff TYPE contains a use of 'auto'. Since auto can only
18429 appear as a type-specifier for the declaration in question, we don't
18430 have to look through the whole type. */
18433 type_uses_auto (tree type)
18435 enum tree_code code;
18436 if (is_auto (type))
18439 code = TREE_CODE (type);
18441 if (code == POINTER_TYPE || code == REFERENCE_TYPE
18442 || code == OFFSET_TYPE || code == FUNCTION_TYPE
18443 || code == METHOD_TYPE || code == ARRAY_TYPE)
18444 return type_uses_auto (TREE_TYPE (type));
18446 if (TYPE_PTRMEMFUNC_P (type))
18447 return type_uses_auto (TREE_TYPE (TREE_TYPE
18448 (TYPE_PTRMEMFUNC_FN_TYPE (type))));
18453 /* For a given template T, return the vector of typedefs referenced
18454 in T for which access check is needed at T instantiation time.
18455 T is either a FUNCTION_DECL or a RECORD_TYPE.
18456 Those typedefs were added to T by the function
18457 append_type_to_template_for_access_check. */
18459 VEC(qualified_typedef_usage_t,gc)*
18460 get_types_needing_access_check (tree t)
18463 VEC(qualified_typedef_usage_t,gc) *result = NULL;
18465 if (!t || t == error_mark_node)
18468 if (!(ti = get_template_info (t)))
18471 if (CLASS_TYPE_P (t)
18472 || TREE_CODE (t) == FUNCTION_DECL)
18474 if (!TI_TEMPLATE (ti))
18477 result = TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti);
18483 /* Append the typedef TYPE_DECL used in template T to a list of typedefs
18484 tied to T. That list of typedefs will be access checked at
18485 T instantiation time.
18486 T is either a FUNCTION_DECL or a RECORD_TYPE.
18487 TYPE_DECL is a TYPE_DECL node representing a typedef.
18488 SCOPE is the scope through which TYPE_DECL is accessed.
18489 LOCATION is the location of the usage point of TYPE_DECL.
18491 This function is a subroutine of
18492 append_type_to_template_for_access_check. */
18495 append_type_to_template_for_access_check_1 (tree t,
18498 location_t location)
18500 qualified_typedef_usage_t typedef_usage;
18503 if (!t || t == error_mark_node)
18506 gcc_assert ((TREE_CODE (t) == FUNCTION_DECL
18507 || CLASS_TYPE_P (t))
18509 && TREE_CODE (type_decl) == TYPE_DECL
18512 if (!(ti = get_template_info (t)))
18515 gcc_assert (TI_TEMPLATE (ti));
18517 typedef_usage.typedef_decl = type_decl;
18518 typedef_usage.context = scope;
18519 typedef_usage.locus = location;
18521 VEC_safe_push (qualified_typedef_usage_t, gc,
18522 TI_TYPEDEFS_NEEDING_ACCESS_CHECKING (ti),
18526 /* Append TYPE_DECL to the template TEMPL.
18527 TEMPL is either a class type, a FUNCTION_DECL or a a TEMPLATE_DECL.
18528 At TEMPL instanciation time, TYPE_DECL will be checked to see
18529 if it can be accessed through SCOPE.
18530 LOCATION is the location of the usage point of TYPE_DECL.
18532 e.g. consider the following code snippet:
18539 template<class U> struct S
18541 C::myint mi; // <-- usage point of the typedef C::myint
18546 At S<char> instantiation time, we need to check the access of C::myint
18547 In other words, we need to check the access of the myint typedef through
18548 the C scope. For that purpose, this function will add the myint typedef
18549 and the scope C through which its being accessed to a list of typedefs
18550 tied to the template S. That list will be walked at template instantiation
18551 time and access check performed on each typedefs it contains.
18552 Note that this particular code snippet should yield an error because
18553 myint is private to C. */
18556 append_type_to_template_for_access_check (tree templ,
18559 location_t location)
18561 qualified_typedef_usage_t *iter;
18564 gcc_assert (type_decl && (TREE_CODE (type_decl) == TYPE_DECL));
18566 /* Make sure we don't append the type to the template twice. */
18568 VEC_iterate (qualified_typedef_usage_t,
18569 get_types_needing_access_check (templ),
18572 if (iter->typedef_decl == type_decl && scope == iter->context)
18575 append_type_to_template_for_access_check_1 (templ, type_decl,
18579 /* Set up the hash tables for template instantiations. */
18582 init_template_processing (void)
18584 decl_specializations = htab_create_ggc (37,
18585 hash_specialization,
18586 eq_specializations,
18588 type_specializations = htab_create_ggc (37,
18589 hash_specialization,
18590 eq_specializations,
18594 /* Print stats about the template hash tables for -fstats. */
18597 print_template_statistics (void)
18599 fprintf (stderr, "decl_specializations: size %ld, %ld elements, "
18600 "%f collisions\n", (long) htab_size (decl_specializations),
18601 (long) htab_elements (decl_specializations),
18602 htab_collisions (decl_specializations));
18603 fprintf (stderr, "type_specializations: size %ld, %ld elements, "
18604 "%f collisions\n", (long) htab_size (type_specializations),
18605 (long) htab_elements (type_specializations),
18606 htab_collisions (type_specializations));
18609 #include "gt-cp-pt.h"